A new study by MIT physicists proposes that a mysterious force known as early dark energy could solve two of the biggest puzzles in cosmology and fill in some major gaps in our understanding of how the early universe evolved.
One puzzle in question is the “Hubble tension,” which refers to a mismatch in measurements of how fast the universe is expanding. The other involves observations of numerous early, bright galaxies that existed at a time when the early universe should have been much less populated.
Now, the MIT team has found that both puzzles could be resolved if the early universe had one extra, fleeting ingredient: early dark energy. Dark energy is an unknown form of energy that physicists suspect is driving the expansion of the universe today. Early dark energy is a similar, hypothetical phenomenon that may have made only a brief appearance, influencing the expansion of the universe in its first moments before disappearing entirely.
Some physicists have suspected that early dark energy could be the key to solving the Hubble tension, as the mysterious force could accelerate the early expansion of the universe by an amount that would resolve the measurement mismatch.
The MIT researchers have now found that early dark energy could also explain the baffling number of bright galaxies that astronomers have observed in the early universe. In their new study, reported today in the Monthly Notices of the Royal Astronomical Society, the team modeled the formation of galaxies in the universe’s first few hundred million years. When they incorporated a dark energy component only in that earliest sliver of time, they found the number of galaxies that arose from the primordial environment bloomed to fit astronomers’ observations.
“You have these two looming open-ended puzzles,” says study co-author Rohan Naidu, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. “We find that in fact, early dark energy is a very elegant and sparse solution to two of the most pressing problems in cosmology.”
The study’s co-authors include lead author and Kavli postdoc Xuejian (Jacob) Shen, and MIT professor of physics Mark Vogelsberger, along with Michael Boylan-Kolchin at the University of Texas at Austin, and Sandro Tacchella at the University of Cambridge.
Big city lights
Based on standard cosmological and galaxy formation models, the universe should have taken its time spinning up the first galaxies. It would have taken billions of years for primordial gas to coalesce into galaxies as large and bright as the Milky Way.
But in 2023, NASA’s James Webb Space Telescope (JWST) made a startling observation. With an ability to peer farther back in time than any observatory to date, the telescope uncovered a surprising number of bright galaxies as large as the modern Milky Way within the first 500 million years, when the universe was just 3 percent of its current age.
“The bright galaxies that JWST saw would be like seeing a clustering of lights around big cities, whereas theory predicts something like the light around more rural settings like Yellowstone National Park,” Shen says. “And we don’t expect that clustering of light so early on.”
For physicists, the observations imply that there is either something fundamentally wrong with the physics underlying the models or a missing ingredient in the early universe that scientists have not accounted for. The MIT team explored the possibility of the latter, and whether the missing ingredient might be early dark energy.
Physicists have proposed that early dark energy is a sort of antigravitational force that is turned on only at very early times. This force would counteract gravity’s inward pull and accelerate the early expansion of the universe, in a way that would resolve the mismatch in measurements. Early dark energy, therefore, is considered the most likely solution to the Hubble tension.
Galaxy skeleton
The MIT team explored whether early dark energy could also be the key to explaining the unexpected population of large, bright galaxies detected by JWST. In their new study, the physicists considered how early dark energy might affect the early structure of the universe that gave rise to the first galaxies. They focused on the formation of dark matter halos — regions of space where gravity happens to be stronger, and where matter begins to accumulate.
“We believe that dark matter halos are the invisible skeleton of the universe,” Shen explains. “Dark matter structures form first, and then galaxies form within these structures. So, we expect the number of bright galaxies should be proportional to the number of big dark matter halos.”
The team developed an empirical framework for early galaxy formation, which predicts the number, luminosity, and size of galaxies that should form in the early universe, given some measures of “cosmological parameters.” Cosmological parameters are the basic ingredients, or mathematical terms, that describe the evolution of the universe.
Physicists have determined that there are at least six main cosmological parameters, one of which is the Hubble constant — a term that describes the universe’s rate of expansion. Other parameters describe density fluctuations in the primordial soup, immediately after the Big Bang, from which dark matter halos eventually form.
The MIT team reasoned that if early dark energy affects the universe’s early expansion rate, in a way that resolves the Hubble tension, then it could affect the balance of the other cosmological parameters, in a way that might increase the number of bright galaxies that appear at early times. To test their theory, they incorporated a model of early dark energy (the same one that happens to resolve the Hubble tension) into an empirical galaxy formation framework to see how the earliest dark matter structures evolve and give rise to the first galaxies.
“What we show is, the skeletal structure of the early universe is altered in a subtle way where the amplitude of fluctuations goes up, and you get bigger halos, and brighter galaxies that are in place at earlier times, more so than in our more vanilla models,” Naidu says. “It means things were more abundant, and more clustered in the early universe.”
“A priori, I would not have expected the abundance of JWST’s early bright galaxies to have anything to do with early dark energy, but their observation that EDE pushes cosmological parameters in a direction that boosts the early-galaxy abundance is interesting,” says Marc Kamionkowski, professor of theoretical physics at Johns Hopkins University, who was not involved with the study. “I think more work will need to be done to establish a link between early galaxies and EDE, but regardless of how things turn out, it’s a clever — and hopefully ultimately fruitful — thing to try.”
“We demonstrated the potential of early dark energy as a unified solution to the two major issues faced by cosmology. This might be an evidence for its existence if the observational findings of JWST get further consolidated,” Vogelsberger concludes. “In the future, we can incorporate this into large cosmological simulations to see what detailed predictions we get.”
This research was supported, in part, by NASA and the National Science Foundation.
Harnessing the power of placebo for pain reliefMIT researchers investigate the neural circuits that underlie placebos’ ability to relieve chronic and acute pain.Placebos are inert treatments, generally not expected to impact biological pathways or improve a person’s physical health. But time and again, some patients report that they feel better after taking a placebo. Increasingly, doctors and scientists are recognizing that rather than dismissing placebos as mere trickery, they may be able to help patients by harnessing their power.
To maximize the impact of the placebo effect and design reliable therapeutic strategies, researchers need a better understanding of how it works. Now, with a new animal model developed by scientists at the McGovern Institute at MIT, they will be able to investigate the neural circuits that underlie placebos’ ability to elicit pain relief.
“The brain and body interaction has a lot of potential, in a way that we don't fully understand,” says Fan Wang, an MIT professor of brain and cognitive sciences and investigator at the McGovern Institute. “I really think there needs to be more of a push to understand placebo effect, in pain and probably in many other conditions. Now we have a strong model to probe the circuit mechanism.”
Context-dependent placebo effect
In the Sept. 5, 2024, issue of the journal Current Biology, Wang and her team report that they have elicited strong placebo pain relief in mice by activating pain-suppressing neurons in the brain while the mice are in a specific environment, thereby teaching the animals that they feel better when they are in that context. Following their training, placing the mice in that environment alone is enough to suppress pain. The team’s experiments — which were funded by the National Institutes of Health, the K. Lisa Yang Brain-Body Center, and the K. Lisa Yang and Hock E. Tan Center for Molecular Therapeutics within MIT’s Yang Tan Collective — show that this context-dependent placebo effect relieves both acute and chronic pain.
Context is critical for the placebo effect. While a pill can help a patient feel better when they expect it to, even if it is made only of sugar or starch, it seems to be not just the pill that sets up those expectations, but the entire scenario in which the pill is taken. For example, being in a hospital and interacting with doctors can contribute to a patient’s perception of care, and these social and environmental factors can make a placebo effect more probable.
MIT postdocs Bin Chen and Nitsan Goldstein used visual and textural cues to define a specific place. Then they activated pain-suppressing neurons in the brain while the animals were in this “pain-relief box.” Those pain-suppressing neurons, which Wang’s lab discovered a few years ago, are located in an emotion-processing center of the brain called the central amygdala. By expressing light-sensitive channels in these neurons, the researchers were able to suppress pain with light in the pain-relief box and leave the neurons inactive when mice were in a control box.
Animals learned to prefer the pain-relief box to other environments. And when the researchers tested their response to potentially painful stimuli after they had made that association, they found the mice were less sensitive while they were there. “Just by being in the context that they had associated with pain suppression, we saw that reduced pain—even though we weren't actually activating those [pain-suppressing] neurons,” Goldstein explains.
Acute and chronic pain relief
Some scientists have been able to elicit placebo pain relief in rodents by treating the animals with morphine, linking environmental cues to the pain suppression caused by the drugs similar to the way Wang’s team did by directly activating pain-suppressing neurons. This drug-based approach works best for setting up expectations of relief for acute pain; its placebo effect is short-lived and mostly ineffective against chronic pain. So Wang, Chen, and Goldstein were particularly pleased to find that their engineered placebo effect was effective for relieving both acute and chronic pain.
In their experiments, animals experiencing a chemotherapy-induced hypersensitivity to touch exhibited a preference for the pain relief box as much as animals who were exposed to a chemical that induces acute pain, days after their initial conditioning. Once there, their chemotherapy-induced pain sensitivity was eliminated; they exhibited no more sensitivity to painful stimuli than they had prior to receiving chemotherapy.
One of the biggest surprises came when the researchers turned their attention back to the pain-suppressing neurons in the central amygdala that they had used to trigger pain relief. They suspected that those neurons might be reactivated when mice returned to the pain-relief box. Instead, they found that after the initial conditioning period, those neurons remained quiet. “These neurons are not reactivated, yet the mice appear to be no longer in pain,” Wang says. “So it suggests this memory of feeling well is transferred somewhere else.”
Goldstein adds that there must be a pain-suppressing neural circuit somewhere that is activated by pain-relief-associated contexts — and the team’s new placebo model sets researchers up to investigate those pathways. A deeper understanding of that circuitry could enable clinicians to deploy the placebo effect — alone or in combination with active treatments — to better manage patients’ pain in the future.
Tools for making imagination blossom at MIT.nanoNew STUDIO.nano supports artistic research and encounters within MIT.nano’s facilities.The MIT community and visitors have a new reason to drop by MIT.nano: six artworks by Brazilian artist and sculptor Denise Milan. Located in the open-air stairway connecting the first- and second-floor galleries within the nanoscience and engineering facility, the works center around the stone as a microcosm of nature. From Milan’s “Mist of the Earth” series, evocative of mandalas, the project asks viewers to reflect on the environmental changes that result from human-made development.
Milan is the inaugural artist in “Encounters,” a series presented by STUDIO.nano, a new initiative from MIT.nano that encourages the exploration of platforms and pathways at the intersection of technology, science, and art. Encounters welcomes proposals from artists, scientists, engineers, and designers from outside of the MIT community looking to collaborate with MIT.nano researchers, facilities, ongoing projects, and unique spaces.
“Life is in the art of the encounter,” remarked Milan, quoting Brazilian poet Vinicius de Moraes, during a reception at MIT.nano. “And for an artist to be in a place like this, MIT.nano, what could be better? I love the curiosity of scientists. They are very much like artists ... art and science are both tools for making imagination blossom.” What followed was a freewheeling conversation between attendees that spanned topics ranging from the cyclical nature of birth, death, and survival in the cosmos to musings on the elemental sources of creativity and the similarities in artistic and scientific practice to a brief lesson on time crystals by Nobel Prize laureate Frank Wilczek, the Herman Feshbach Professor of Physics at MIT.
Milan was joined in her conversation by MIT.nano Director Vladimir Bulović, the Fariborz Maseeh Professor of Emerging Technologies; Ardalan SadeghiKivi MArch ’22, who moderated the discussion; Samantha Farrell, manager of STUDIO.nano programming; and Naomi Moniz, professor emeritus at Georgetown University, who connected Milan and her work with MIT.nano.
“In addition to the technical community, we [at MIT.nano] have been approached by countless artists and thinkers in the humanities who, to our delight, are eager to learn about the wonders of the nanoscale and how to use the tools of MIT.nano to explore and expand their own artistic practice,” said Bulović.
These interactions have spurred collaborative projects across disciplines, art exhibitions, and even MIT classes. For the past four years MIT.nano has hosted 4.373/4.374 (Creating Art, Thinking Science), an undergraduate and graduate class offered by the Art, Culture, and Technology (ACT) Program. To date, the class has brought 35 students into MIT.nano’s labs and resulted in 40 distinct projects and 60 pieces of art, many of which are on display in MIT.nano’s galleries.
With the launch of STUDIO.nano, MIT.nano will look to expand its exhibition programs, including supporting additional digital media and augmented/virtual reality projects; providing tools and spaces for development of new classes envisioned by MIT academic departments; and introducing programming such as lectures related to the studio's activities.
Milan’s work will be a permanent installation at MIT.nano, where she hopes it will encourage individuals to pursue their creative inspiration, regardless of discipline. “To exist or to disappear?” Milan asked. “If it’s us, an idea, or a dream — the question is how much of an assignment you have with your own imagination.”
No detail too smallFor Sarah Sterling, the new director of the Cryo-Electron Microscopy facility at MIT.nano, better planning and more communication leads to better science.Sarah Sterling, director of the Cryo-Electron Microscopy, or Cryo-EM, core facility, often compares her job to running a small business. Each day brings a unique set of jobs ranging from administrative duties and managing facility users to balancing budgets and maintaining equipment.
Although one could easily be overwhelmed by the seemingly never-ending to-do list, Sterling finds a great deal of joy in wearing so many different hats. One of her most essential tasks involves clear communication with users when the delicate instruments in the facility are unusable because of routine maintenance and repairs.
“Better planning allows for better science,” Sterling says. “Luckily, I’m very comfortable with building and fixing things. Let’s troubleshoot. Let’s take it apart. Let’s put it back together.”
Out of all her duties as a core facility director, she most looks forward to the opportunities to teach, especially helping students develop research projects.
“Undergraduate or early-stage graduate students ask the best questions,” she says. “They’re so curious about the tiny details, and they’re always ready to hit the ground running on their projects.”
A non-linear scientific journey
When Sterling enrolled in Russell Sage College, a women’s college in New York, she was planning to pursue a career as a physical therapist. However, she quickly realized she loved her chemistry classes more than her other subjects. She graduated with a bachelor of science degree in chemistry and immediately enrolled in a master’s degree program in chemical engineering at the University of Maine.
Sterling was convinced to continue her studies at the University of Maine with a dual PhD in chemical engineering and biomedical sciences. That decision required the daunting process of taking two sets of core courses and completing a qualifying exam in each field.
“I wouldn’t recommend doing that,” she says with a laugh. “To celebrate after finishing that intense experience, I took a year off to figure out what came next.”
Sterling chose to do a postdoc in the lab of Eva Nogales, a structural biology professor at the University of California at Berkeley. Nogales was looking for a scientist with experience working with lipids, a class of molecules that Sterling had studied extensively in graduate school.
At the time Sterling joined, the Nogales Lab was at the forefront of implementing an exciting structural biology approach: cryo-EM.
“When I was interviewing, I’d never even seen the type of microscope required for cryo-EM, let alone performed any experiments,” Sterling says. “But I remember thinking ‘I’m sure I can figure this out.’”
Cryo-EM is a technique that allows researchers to determine the three-dimensional shape, or structure, of the macromolecules that make up cells. A researcher can take a sample of their macromolecule of choice, suspend it in a liquid solution, and rapidly freeze it onto a grid to capture the macromolecules in random positions — the “cryo” part of the name. Powerful electron microscopes then collect images of the macromolecule — the EM part of cryo-EM.
The two-dimensional images of the macromolecules from different angles can be combined to produce a three-dimensional structure. Structural information like this can reveal the macromolecule’s function inside cells or inform how it differs in a disease state. The rapidly expanding use of cryo-EM has unlocked so many mechanistic insights that the researchers who developed the technology were awarded the 2017 Nobel Prize in Chemistry.
The MIT.nano facility opened its doors in 2018. The open-access, state-of-the-art facility now has more than 160 tools and more than 1,500 users representing nearly every department at MIT. The Cryo-EM facility lives in the basement of the MIT.nano building and houses multiple electron microscopes and laboratory space for cryo-specimen preparation.
Thanks to her work at UC Berkeley, Sterling’s career trajectory has long been intertwined with the expanding use of cryo-EM in research. Sterling anticipated the need for experienced scientists to run core facilities in order to maintain the electron microscopes needed for cryo-EM, which range in cost from a staggering $1 million to $10 million each.
After completing her postdoc, Sterling worked at the Harvard University cryo-EM core facility for five years. When the director position for the MIT.nano Cryo-EM facility opened, she decided to apply.
“I like that the core facility at MIT was smaller and more frequently used by students,” Sterling says. “There’s a lot more teaching, which is a challenge sometimes, but it’s rewarding to impact someone’s career at such an early stage.”
A focus on users
When Sterling arrived at MIT, her first initiative was to meet directly with all the students in research labs that use the core facility to learn what would make using the facility a better experience. She also implemented clear and standard operating procedures for cryo-EM beginners.
“I think being consistent and available has really improved users’ experiences,” Sterling says.
The users themselves report that her initiatives have proven highly successful — and have helped them grow as scientists.
“Sterling cultivates an environment where I can freely ask questions about anything to support my learning,” says Bonnie Su, a frequent Cryo-EM facility user and graduate student from the Vos lab.
But Sterling does not want to stop there. Looking ahead, she hopes to expand the facility by acquiring an additional electron microscope to allow more users to utilize this powerful technology in their research. She also plans to build a more collaborative community of cryo-EM scientists at MIT with additional symposia and casual interactions such as coffee hours.
Under her management, cryo-EM research has flourished. In the last year, the Cryo-EM core facility has supported research resulting in 12 new publications across five different departments at MIT. The facility has also provided access to 16 industry and non-MIT academic entities. These studies have revealed important insights into various biological processes, from visualizing how large protein machinery reads our DNA to the protein aggregates found in neurodegenerative disorders.
If anyone wants to conduct cryo-EM experiments or learn more about the technique, Sterling encourages anyone in the MIT community to reach out.
“Come visit us!” she says. “We give lots of tours, and you can stop by to say hi anytime.”
Study assesses seizure risk from stimulating the thalamusIn animal models, even low stimulation currents can sometimes still cause electrographic seizures, researchers found.The idea of electrically stimulating a brain region called the central thalamus has gained traction among researchers and clinicians because it can help arouse subjects from unconscious states induced by traumatic brain injury or anesthesia, and can boost cognition and performance in awake animals. But the method, called CT-DBS, can have a side effect: seizures. A new study by researchers at MIT and Massachusetts General Hospital (MGH) who were testing the method in awake mice quantifies the probability of seizures at different stimulation currents and cautions that they sometimes occurred even at low levels.
“Understanding production and prevalence of this type of seizure activity is important because brain stimulation-based therapies are becoming more widely used,” says co-senior author Emery N. Brown, Edward Hood Taplin Professor of Medical Engineering and Computational Neuroscience in The Picower Institute for Learning and Memory, the Institute for Medical Engineering and Science, the Department of Brain and Cognitive Sciences, and the Center for Brains Minds and Machines (CBMM) at MIT.
In the brain, the seizures associated with CT-DBS occur as “electrographic seizures,” which are bursts of voltage among neurons across a broad spectrum of frequencies. Behaviorally, they manifest as “absence seizures” in which the subject appears to take on a blank stare and freezes for about 10-20 seconds.
In their study, the researchers were hoping to determine a CT-DBS stimulation current — in a clinically relevant range of under 200 microamps — below which seizures could be reliably avoided.
In search of that ideal current, they developed a protocol of starting brief bouts of CT-DBS at 1 microamp and then incrementally ramping the current up to 200 microamps until they found a threshold where an electrographic seizure occurred. Once they found that threshold, then they tested a longer bout of stimulation at the next lowest current level in hopes that an electrographic seizure wouldn’t occur. They did this for a variety of different stimulation frequencies. To their surprise, electrographic seizures still occurred 2.2 percent of the time during those longer stimulation trials (i.e. 22 times out of 996 tests) and in 10 out of 12 mice. At just 20 microamps, mice still experienced seizures in three out of 244 tests, a 1.2 percent rate.
“This is something that we needed to report because this was really surprising,” says co-lead author Francisco Flores, a research affiliate in The Picower Institute and CBMM, and an instructor in anesthesiology at MGH, where Brown is also an anesthesiologist. Isabella Dalla Betta, a technical associate in The Picower Institute, co-led the study published in Brain Stimulation.
Stimulation frequency didn’t matter for seizure risk but the rate of electrographic seizures increased as the current level increased. For instance, it happened in 5 out of 190 tests at 50 microamps, and two out of 65 tests at 100 microamps. The researchers also found that when an electrographic seizure occurred, it did so more quickly at higher currents than at lower levels. Finally, they also saw that seizures happened more quickly if they stimulated the thalamus on both sides of the brain, versus just one side. Some mice exhibited behaviors similar to absence seizure, though others became hyperactive.
It is not clear why some mice experienced electrographic seizures at just 20 microamps while two mice did not experience the seizures even at 200. Flores speculated that there may be different brain states that change the predisposition to seizures amid stimulation of the thalamus. Notably, seizures are not typically observed in humans who receive CT-DBS while in a minimally conscious state after a traumatic brain injury or in animals who are under anesthesia. Flores said the next stage of the research would aim to discern what the relevant brain states may be.
In the meantime, the study authors wrote, “EEG should be closely monitored for electrographic seizures when performing CT-DBS, especially in awake subjects.”
The paper’s co-senior author is Matt Wilson, Sherman Fairchild Professor in The Picower Institute, CBMM, and the departments of Biology and Brain and Cognitive Sciences. In addition to Dalla Betta, Flores, Brown and Wilson, the study’s other authors are John Tauber, David Schreier, and Emily Stephen.
Support for the research came from The JPB Foundation, The Picower Institute for Learning and Memory; George J. Elbaum ’59, SM ’63, PhD ’67, Mimi Jensen, Diane B. Greene SM ’78, Mendel Rosenblum, Bill Swanson, annual donors to the Anesthesia Initiative Fund; and the National Institutes of Health.
Atoms on the edgePhysicists capture images of ultracold atoms flowing freely, without friction, in an exotic “edge state.”Typically, electrons are free agents that can move through most metals in any direction. When they encounter an obstacle, the charged particles experience friction and scatter randomly like colliding billiard balls.
But in certain exotic materials, electrons can appear to flow with single-minded purpose. In these materials, electrons may become locked to the material’s edge and flow in one direction, like ants marching single-file along a blanket’s boundary. In this rare “edge state,” electrons can flow without friction, gliding effortlessly around obstacles as they stick to their perimeter-focused flow. Unlike in a superconductor, where all electrons in a material flow without resistance, the current carried by edge modes occurs only at a material’s boundary.
Now MIT physicists have directly observed edge states in a cloud of ultracold atoms. For the first time, the team has captured images of atoms flowing along a boundary without resistance, even as obstacles are placed in their path. The results, which appear today in Nature Physics, could help physicists manipulate electrons to flow without friction in materials that could enable super-efficient, lossless transmission of energy and data.
“You could imagine making little pieces of a suitable material and putting it inside future devices, so electrons could shuttle along the edges and between different parts of your circuit without any loss,” says study co-author Richard Fletcher, assistant professor of physics at MIT. “I would stress though that, for us, the beauty is seeing with your own eyes physics which is absolutely incredible but usually hidden away in materials and unable to be viewed directly.”
The study’s co-authors at MIT include graduate students Ruixiao Yao and Sungjae Chi, former graduate students Biswaroop Mukherjee PhD ’20 and Airlia Shaffer PhD ’23, along with Martin Zwierlein, the Thomas A. Frank Professor of Physics. The co-authors are all members of MIT’s Research Laboratory of Electronics and the MIT-Harvard Center for Ultracold Atoms.
Forever on the edge
Physicists first invoked the idea of edge states to explain a curious phenomenon, known today as the Quantum Hall effect, which scientists first observed in 1980, in experiments with layered materials, where electrons were confined to two dimensions. These experiments were performed in ultracold conditions, and under a magnetic field. When scientists tried to send a current through these materials, they observed that electrons did not flow straight through the material, but instead accumulated on one side, in precise quantum portions.
To try and explain this strange phenomenon, physicists came up with the idea that these Hall currents are carried by edge states. They proposed that, under a magnetic field, electrons in an applied current could be deflected to the edges of a material, where they would flow and accumulate in a way that might explain the initial observations.
“The way charge flows under a magnetic field suggests there must be edge modes,” Fletcher says. “But to actually see them is quite a special thing because these states occur over femtoseconds, and across fractions of a nanometer, which is incredibly difficult to capture.”
Rather than try and catch electrons in an edge state, Fletcher and his colleagues realized they might be able to recreate the same physics in a larger and more observable system. The team has been studying the behavior of ultracold atoms in a carefully designed setup that mimics the physics of electrons under a magnetic field.
“In our setup, the same physics occurs in atoms, but over milliseconds and microns,” Zwierlein explains. “That means that we can take images and watch the atoms crawl essentially forever along the edge of the system.”
A spinning world
In their new study, the team worked with a cloud of about 1 million sodium atoms, which they corralled in a laser-controlled trap, and cooled to nanokelvin temperatures. They then manipulated the trap to spin the atoms around, much like riders on an amusement park Gravitron.
“The trap is trying to pull the atoms inward, but there’s centrifugal force that tries to pull them outward,” Fletcher explains. “The two forces balance each other, so if you’re an atom, you think you’re living in a flat space, even though your world is spinning. There’s also a third force, the Coriolis effect, such that if they try to move in a line, they get deflected. So these massive atoms now behave as if they were electrons living in a magnetic field.”
Into this manufactured reality, the researchers then introduced an “edge,” in the form of a ring of laser light, which formed a circular wall around the spinning atoms. As the team took images of the system, they observed that when the atoms encountered the ring of light, they flowed along its edge, in just one direction.
“You can imagine these are like marbles that you’ve spun up really fast in a bowl, and they just keep going around and around the rim of the bowl,” Zwierlein offers. “There is no friction. There is no slowing down, and no atoms leaking or scattering into the rest of the system. There is just beautiful, coherent flow.”
“These atoms are flowing, free of friction, for hundreds of microns,” Fletcher adds. “To flow that long, without any scattering, is a type of physics you don’t normally see in ultracold atom systems.”
This effortless flow held up even when the researchers placed an obstacle in the atoms’ path, like a speed bump, in the form of a point of light, which they shone along the edge of the original laser ring. Even as they came upon this new obstacle, the atoms didn’t slow their flow or scatter away, but instead glided right past without feeling friction as they normally would.
“We intentionally send in this big, repulsive green blob, and the atoms should bounce off it,” Fletcher says. “But instead what you see is that they magically find their way around it, go back to the wall, and continue on their merry way.”
The team’s observations in atoms document the same behavior that has been predicted to occur in electrons. Their results show that the setup of atoms is a reliable stand-in for studying how electrons would behave in edge states.
“It’s a very clean realization of a very beautiful piece of physics, and we can directly demonstrate the importance and reality of this edge,” Fletcher says. “A natural direction is to now introduce more obstacles and interactions into the system, where things become more unclear as to what to expect.”
This research was supported, in part, by the National Science Foundation.
3 Questions: Evidence for planetary formation through gravitational instabilityAssistant Professor Richard Teague describes how movement of unstable gas in a protoplanetary disk lends credibility to a secondary theory of planetary formation.Exoplanets form in protoplanetary disks, a collection of space dust and gas orbiting a star. The leading theory of planetary formation, called core accretion, occurs when grains of dust in the disk collect and grow to form a planetary core, like a snowball rolling downhill. Once it has a strong enough gravitational pull, other material collapses around it to form the atmosphere.
A secondary theory of planetary formation is gravitational collapse. In this scenario, the disk itself becomes gravitationally unstable and collapses to form the planet, like snow being plowed into a pile. This process requires the disk to be massive, and until recently there were no known viable candidates to observe; previous research had detected the snow pile, but not what made it.
But in a new paper published today in Nature, MIT Kerr-McGee Career Development Professor Richard Teague and his colleagues report evidence that the movement of the gas surrounding the star AB Aurigae behaves as one would expect in a gravitationally unstable disk, matching numerical predictions. Their finding is akin to detecting the snowplow that made the pile. This indicates that gravitational collapse is a viable method of planetary formation. Here, Teague, who studies the formation of planetary systems in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS), answers a few questions about the new work.
Q: What made the AB Aurigae system a good candidate for observation?
A: There have been plenty of observations that have suggested some interesting dynamics going on the system. Groups have seen spiral arms within the disk; people have found hot spots, which some groups have interpreted as a planet; others have explained as some other instability. But it was really a disk that we knew there was lots of interesting motions going on. The data that we had previously was enough to see that it was interesting, but not really good enough to detail what was going on.
Q: What is gravitational instability when it comes to protoplanetary disks?
A: Gravitational instabilities are where the gravity from the disk itself is strong enough to perturb motions within the disk. Usually, we assume that the gravitational potential is dominated by the central star, which is the case when the mass of the disk is less than 10 percent of the stellar mass (which is most of the time). When the disk mass gets too large, gravitational potential will affect it in different ways and drive these very large spiral arms in the disk. These can have lots of different effects: They can trap the gas, they can heat it up, they can allow for angular momentum to be transported very rapidly within the disk. If it’s unstable, the disk can fragment and collapse directly to form a planet in an incredibly short period of time. Rather than the tens of thousands of years that it would take for a core accretion to happen, this would happen at a fraction of that time.
Q: How does this discovery challenge conventional wisdom around planetary formation?
A: It shows that this alternative path of forming planets via direct collapse is a way that we can form planets. This is particularly important because we’re finding more and more evidence of very large planets — say, Jupiter mass or larger — that are sitting very far away from their star. Those sorts of planets are incredibly hard to form with core accretion, because you typically need them close to the star where things happen quickly. So to form something so massive, so far away from the star is a real challenge. If we're able to show that there are sources that are massive enough that they're gravitationally unstable, this solves that problem. It's a way that perhaps newer systems can be formed, because they've always been a bit of a challenge to understand how they came about with core accretion.
MIT chemists explain why dinosaur collagen may have survived for millions of yearsThe researchers identified an atomic-level interaction that prevents peptide bonds from being broken down by water.Collagen, a protein found in bones and connective tissue, has been found in dinosaur fossils as old as 195 million years. That far exceeds the normal half-life of the peptide bonds that hold proteins together, which is about 500 years.
A new study from MIT offers an explanation for how collagen can survive for so much longer than expected. The research team found that a special atomic-level interaction defends collagen from attack by water molecules. This barricade prevents water from breaking the peptide bonds through a process called hydrolysis.
“We provide evidence that that interaction prevents water from attacking the peptide bonds and cleaving them. That just flies in the face of what happens with a normal peptide bond, which has a half-life of only 500 years,” says Ron Raines, the Firmenich Professor of Chemistry at MIT.
Raines is the senior author of the new study, which appears today in ACS Central Science. MIT postdoc Jinyi Yang PhD ’24 is the lead author of the paper. MIT postdoc Volga Kojasoy and graduate student Gerard Porter are also authors of the study.
Water-resistant
Collagen is the most abundant protein in animals, and it is found in not only bones but also skin, muscles, and ligaments. It’s made from long strands of protein that intertwine to form a tough triple helix.
“Collagen is the scaffold that holds us together,” Raines says. “What makes the collagen protein so stable, and such a good choice for this scaffold, is that unlike most proteins, it’s fibrous.”
In the past decade, paleobiologists have found evidence of collagen preserved in dinosaur fossils, including an 80-million-year-old Tyrannosaurus rex fossil, and a sauropodomorph fossil that is nearly 200 million years old.
Over the past 25 years, Raines’ lab has been studying collagen and how its structure enables its function. In the new study, they revealed why the peptide bonds that hold collagen together are so resistant to being broken down by water.
Peptide bonds are formed between a carbon atom from one amino acid and a nitrogen atom of the adjacent amino acid. The carbon atom also forms a double bond with an oxygen atom, forming a molecular structure called a carbonyl group. This carbonyl oxygen has a pair of electrons that don’t form bonds with any other atoms. Those electrons, the researchers found, can be shared with the carbonyl group of a neighboring peptide bond.
Because this pair of electrons is being inserted into those peptide bonds, water molecules can’t also get into the structure to disrupt the bond.
To demonstrate this, Raines and his colleagues created two interconverting mimics of collagen — the one that usually forms a triple helix, which is known as trans, and another in which the angles of the peptide bonds are rotated into a different form, known as cis. They found that the trans form of collagen did not allow water to attack and hydrolyze the bond. In the cis form, water got in and the bonds were broken.
“A peptide bond is either cis or trans, and we can change the cis to trans ratio. By doing that, we can mimic the natural state of collagen or create an unprotected peptide bond. And we saw that when it was unprotected, it was not long for the world,” Raines says.
“This work builds on a long-term effort in the Raines Group to classify the role of a long-overlooked fundamental interaction in protein structure,” says Paramjit Arora, a professor of chemistry at New York University, who was not involved in the research. “The paper directly addresses the remarkable finding of intact collagen in the ribs of a 195-million-old dinosaur fossil, and shows that overlap of filled and empty orbitals controls the conformational and hydrolytic stability of collagen.”
“No weak link”
This sharing of electrons has also been seen in protein structures known as alpha helices, which are found in many proteins. These helices may also be protected from water, but the helices are always connected by protein sequences that are more exposed, which are still susceptible to hydrolysis.
“Collagen is all triple helices, from one end to the other,” Raines says. “There’s no weak link, and that’s why I think it has survived.”
Previously, some scientists have suggested other explanations for why collagen might be preserved for millions of years, including the possibility that the bones were so dehydrated that no water could reach the peptide bonds.
“I can’t discount the contributions from other factors, but 200 million years is a long time, and I think you need something at the molecular level, at the atomic level in order to explain it,” Raines says.
The research was funded by the National Institutes of Health and the National Science Foundation.
Engineering proteins to treat cancerPhD student Oscar Molina seeks new ways to assemble proteins into targeted cancer therapies, while also encouraging his fellow first-generation graduate students.Like many children of first-generation immigrants, Oscar Molina grew up feeling like he had two career choices: doctor or lawyer. He seemed destined for the former as he excelled in high school and planned to major in biochemistry at the University of California at Los Angeles, but as an undergraduate, he fell in love with research.
“I was fascinated by discovery. As I did it more in college, I realized I didn’t want to be a doctor,” he says. “Once I saw that I could make an impact and be at the forefront of therapy with biotech, I knew I wanted to do that.”
If the next couple of years go as planned, his parents will indeed see their son become a doctor — just not exactly the way they might have guessed. He’s entering the fifth year of his PhD program in biology at MIT and is currently working in the lab of Professor Ronald Raines, researching the potential of proteins to kill cancer cells.
Molina, who is the first in his family to attend college, also works to support his fellow students through outreach and community-building efforts. In various roles, including as a Graduate Community Fellow in MIT’s Office of Graduate Education, he sought to connect and encourage students from underrepresented backgrounds as they pursued their own graduate studies.
“I had a lot of opportunities presented to me that made me ask, ‘Why me?’” he says. “I recognize that they were super valuable, and that’s why I should deliver that back to other people.”
Unlocking protein construction chemically
The spirit of giving back isn’t just limited to Molina’s work outside of the lab. He chose chemical biology and the pursuit of new cancer therapies as his research focus partly because his grandfather has been dealing with the disease for the last 10 years. The ultimate goal guiding his research is to make all protein-based cancer therapies more effective.
He and other collaborators in the Raines Lab published a paper in June that takes an important step in that direction, suggesting a way to make fusion proteins with greater customization and improved performance. They discovered that a chemical called 3-bromo-5-methylene pyrrolone can be used to combine three proteins efficiently and with high levels of control and modularity, a significant advance given most of the techniques for protein conjugation are only able to combine two at a time in a single spot.
“Now, we can have chemical control of where we include different things, where we can kind of plug-and-play,” he says.
Researchers can now adjust multiple characteristics at the same time — for example, increasing the protein’s half-life or improving its ability to target cancer cells — while still achieving a homogenous end product. They’re also relevant to immune cell redirection therapies, which require multimeric protein chimeras to activate immune clearance of cancer cells.
“That’s the most interesting thing to me,” he says. “How do we give a biologic therapy the best opportunity to be active and efficacious?”
His upcoming thesis will center around that question as it relates to chemotherapies based on ribonuclease 1, an enzyme that is best-known for cleaving RNA.
Paying it back and paying it forward
While that thesis will likely demand more of Molina than any other project he’s worked on in the past, he’s no stranger to hard work. After his mother and father left their respective homes of Guatemala and El Salvador in the 1990s, they dedicated their lives to giving their children futures that they themselves didn’t have access to.
Witnessing their efforts impressed two beliefs into Molina’s worldview: the value of education and the importance of support. Among his family, he is the first to graduate from a U.S. high school, the first to attend a four-year college, and the first to attend graduate school. These “firsts” can weigh heavily, and as he began his studies at MIT, he knew how difficult it can be to carry that burden alone.
“I saw the need and wanted to help other people be the first in their family to do things like go to college,” he says. “I also wanted to help people with similar backgrounds to mine, like being an underrepresented minority or a first-generation college student.”
That desire led Molina to join MIT’s Office of Graduate Education as a Graduate Community Fellow in January 2022, where he worked on supporting various affinity groups across the Institute. This included helping groups out with logistics, funding applications, community outreach and cross-group collaborations. He also spent part of last summer as a pod leader for the MIT Summer Research Program, which works to prepare underrepresented students for graduate education and research.
He’s also leveraged his personal interests to volunteer with various community organizations in Cambridge and Boston. Despite his numerous commitments, he’s an avid marathon runner, and ran the 2022 Boston Marathon while raising nearly $8000 for Boston Scores, a program that provides educational and athletic opportunities for students in the Boston Public Schools system.
After graduation, Molina plans on joining a startup in Boston’s biotech scene while learning more about the venture capital firms that fund their research. Wherever he ends up, he plans on continuing to apply the core truths that brought him where he is now.
“I want to be at the forefront of creating therapies. I really like science. I really like helping others. I really like the ability to create things that are impactful,” he says. “Now it’s time to take that and find my way to what’s next.”
Nurturing successProfessors Mariya Grinberg and Nuh Gedik are honored as “Committed to Caring.”The start and finish of a degree program are pivotal moments in the lives of MIT's graduate students. In her first three years in MIT’s Department of Political Science, professor Mariya Grinberg’s mentorship has helped numerous students start their graduate journeys with confidence and direction. Nuh Gedik, who joined the Department of Physics in 2008, looks to the finish line: he finds joy in seeing his students reach personal and professional success at the end of their PhDs. Both were recently honored as “Committed to Caring” for their support of graduate students.
Mariya Grinberg: Commitment to intellectual growth
When Mariya Grinberg joined the MIT Security Studies Program as a faculty member in 2021, the department was in a state of flux. The Covid-19 pandemic was in full swing, several core faculty members were nearing retirement, and the program had welcomed the largest cohort of PhD students in its history. As Grinberg entered the community, she embraced these challenges, meeting and exceeding her expected duties as an advisor.
In her role as assistant professor of political science, Grinberg’s research interests center on the question of how time and uncertainty shape the strategic decisions of states, focusing on economic statecraft, military planning, and questions of state sovereignty.
As a junior faculty member, Grinberg shoulders one of the largest advising loads in the department. Despite this, multiple nominators praised Grinberg for her prompt and discerning feedback. Students note her efforts in reading through and commenting on many rounds of paper drafts, supplemented by hour-long brainstorming sessions at her whiteboard. “It's rare that someone can become both your most incisive critic and staunchest advocate,” a nominator noted. “I never took it for granted.”
Throughout these sessions, Grinberg delivers her advice with both confidence and empathy. One nominator shared how meetings put them at ease: “Normally, I am quite anxious about meeting with faculty, but I never felt that way during my meetings with Mariya.”
Grinberg believes that failure is an integral part of the learning process and encourages her students to embrace and learn from setbacks. She acknowledges that the pressure to accomplish tasks within time constraints often leaves little room for failure, which can lead to decision paralysis. Grinberg reassures her students that investing time in a dissertation idea, even if it turns out to be non-viable, is not time wasted.
When asked about her philosophy on mentorship, Grinberg emphasizes that the advice of mentors is just that — advice. It represents their best effort to steer students in what they perceive to be a fruitful direction, but it does not mean the advice is invariably correct. Grinberg encourages students to critically evaluate any feedback and make their own judgments that may not align with their advisor's thoughts.
Grinberg shares a concept she first learned from a creative writing professor: “When someone tells you there is something wrong with your work, 90 percent of the time they are right. When someone tells you how to fix it, 90 percent of the time they are wrong.”
Nuh Gedik: Mentoring the next generation of scientists
Gedik is the Donner Professor of Physics at MIT. His group investigates quantum materials by using advanced optical and electron-based spectroscopies. Gedik employs these techniques to study topological insulators, high-temperature superconductors, and atomically layered materials.
When asked about what keeps him motivated, Gedik says that he is driven by the professional development of his students. Gedik prioritizes the growth of his students above all else, and believes that academic output follows naturally with personal and professional growth. One nominator shared one of Gedik’s favorite sayings: “Finding a job for you is my job.”
As a result of this mindset, the alumni of Gedik’s group have achieved spectacular professional success, including members who are now faculty at top universities such as Stanford, Harvard, and Columbia universities. Several group members are also in leadership roles at companies like Intel, Meta, or ASML.
Alongside his academic pursuits, Gedik is deeply committed to promoting diversity, equity, and inclusion within his research group and the broader academic community. He dedicates regular portions of the weekly group meetings to discussing literature and practices related to these topics. Not only do these discussions educate the group on important issues, but they also help lab members integrate inclusive practices into their day-to-day endeavors.
By integrating inclusive principles into his teaching and mentoring, Gedik creates a culture where students are supported personally and academically. In fact, a nominator shared that many of these practices stem from the professional development courses that Gedik voluntarily attends. His proactive approach not only benefits his current students, but also sets a standard that influences others as well.
In addition to his efforts within the lab, Gedik is proactive in scientific outreach and mentorship within the broader community. He attends annual science fairs in educationally under-resourced communities, aiming to inspire the younger generation to pursue careers in STEM. One nominator praises these fairs for “igniting interest in science and technology among diverse audiences,” with a particular focus on inspiring the younger generation.
Scientists find neurons that process language on different timescalesIn language-processing areas of the brain, some cell populations respond to one word, while others respond to strings of words.Using functional magnetic resonance imaging (fMRI), neuroscientists have identified several regions of the brain that are responsible for processing language. However, discovering the specific functions of neurons in those regions has proven difficult because fMRI, which measures changes in blood flow, doesn’t have high enough resolution to reveal what small populations of neurons are doing.
Now, using a more precise technique that involves recording electrical activity directly from the brain, MIT neuroscientists have identified different clusters of neurons that appear to process different amounts of linguistic context. These “temporal windows” range from just one word up to about six words.
The temporal windows may reflect different functions for each population, the researchers say. Populations with shorter windows may analyze the meanings of individual words, while those with longer windows may interpret more complex meanings created when words are strung together.
“This is the first time we see clear heterogeneity within the language network,” says Evelina Fedorenko, an associate professor of neuroscience at MIT. “Across dozens of fMRI experiments, these brain areas all seem to do the same thing, but it’s a large, distributed network, so there’s got to be some structure there. This is the first clear demonstration that there is structure, but the different neural populations are spatially interleaved so we can’t see these distinctions with fMRI.”
Fedorenko, who is also a member of MIT’s McGovern Institute for Brain Research, is the senior author of the study, which appears today in Nature Human Behavior. MIT postdoc Tamar Regev and Harvard University graduate student Colton Casto are the lead authors of the paper.
Temporal windows
Functional MRI, which has helped scientists learn a great deal about the roles of different parts of the brain, works by measuring changes in blood flow in the brain. These measurements act as a proxy of neural activity during a particular task. However, each “voxel,” or three-dimensional chunk, of an fMRI image represents hundreds of thousands to millions of neurons and sums up activity across about two seconds, so it can’t reveal fine-grained detail about what those neurons are doing.
One way to get more detailed information about neural function is to record electrical activity using electrodes implanted in the brain. These data are hard to come by because this procedure is done only in patients who are already undergoing surgery for a neurological condition such as severe epilepsy.
“It can take a few years to get enough data for a task because these patients are relatively rare, and in a given patient electrodes are implanted in idiosyncratic locations based on clinical needs, so it takes a while to assemble a dataset with sufficient coverage of some target part of the cortex. But these data, of course, are the best kind of data we can get from human brains: You know exactly where you are spatially and you have very fine-grained temporal information,” Fedorenko says.
In a 2016 study, Fedorenko reported using this approach to study the language processing regions of six people. Electrical activity was recorded while the participants read four different types of language stimuli: complete sentences, lists of words, lists of non-words, and “jabberwocky” sentences — sentences that have grammatical structure but are made of nonsense words.
Those data showed that in some neural populations in language processing regions, activity would gradually build up over a period of several words, when the participants were reading sentences. However, this did not happen when they read lists of words, lists of nonwords, of Jabberwocky sentences.
In the new study, Regev and Casto went back to those data and analyzed the temporal response profiles in greater detail. In their original dataset, they had recordings of electrical activity from 177 language-responsive electrodes across the six patients. Conservative estimates suggest that each electrode represents an average of activity from about 200,000 neurons. They also obtained new data from a second set of 16 patients, which included recordings from another 362 language-responsive electrodes.
When the researchers analyzed these data, they found that in some of the neural populations, activity would fluctuate up and down with each word. In others, however, activity would build up over multiple words before falling again, and yet others would show a steady buildup of neural activity over longer spans of words.
By comparing their data with predictions made by a computational model that the researchers designed to process stimuli with different temporal windows, the researchers found that neural populations from language processing areas could be divided into three clusters. These clusters represent temporal windows of either one, four, or six words.
“It really looks like these neural populations integrate information across different timescales along the sentence,” Regev says.
Processing words and meaning
These differences in temporal window size would have been impossible to see using fMRI, the researchers say.
“At the resolution of fMRI, we don’t see much heterogeneity within language-responsive regions. If you localize in individual participants the voxels in their brain that are most responsive to language, you find that their responses to sentences, word lists, jabberwocky sentences and non-word lists are highly similar,” Casto says.
The researchers were also able to determine the anatomical locations where these clusters were found. Neural populations with the shortest temporal window were found predominantly in the posterior temporal lobe, though some were also found in the frontal or anterior temporal lobes. Neural populations from the two other clusters, with longer temporal windows, were spread more evenly throughout the temporal and frontal lobes.
Fedorenko’s lab now plans to study whether these timescales correspond to different functions. One possibility is that the shortest timescale populations may be processing the meanings of a single word, while those with longer timescales interpret the meanings represented by multiple words.
“We already know that in the language network, there is sensitivity to how words go together and to the meanings of individual words,” Regev says. “So that could potentially map to what we’re finding, where the longest timescale is sensitive to things like syntax or relationships between words, and maybe the shortest timescale is more sensitive to features of single words or parts of them.”
The research was funded by the Zuckerman-CHE STEM Leadership Program, the Poitras Center for Psychiatric Disorders Research, the Kempner Institute for the Study of Natural and Artificial Intelligence at Harvard University, the U.S. National Institutes of Health, an American Epilepsy Society Research and Training Fellowship, the McDonnell Center for Systems Neuroscience, Fondazione Neurone, the McGovern Institute, MIT’s Department of Brain and Cognitive Sciences, and the Simons Center for the Social Brain.
Pursuing the secrets of a stealthy parasiteBy unraveling the genetic pathways that help Toxoplasma gondii persist in human cells, Sebastian Lourido hopes to find new ways to treat toxoplasmosis.Toxoplasma gondii, the parasite that causes toxoplasmosis, is believed to infect as much as one-third of the world’s population. Many of those people have no symptoms, but the parasite can remain dormant for years and later reawaken to cause disease in anyone who becomes immunocompromised.
Why this single-celled parasite is so widespread, and what triggers it to reemerge, are questions that intrigue Sebastian Lourido, an associate professor of biology at MIT and member of the Whitehead Institute for Biomedical Research. In his lab, research is unraveling the genetic pathways that help to keep the parasite in a dormant state, and the factors that lead it to burst free from that state.
“One of the missions of my lab to improve our ability to manipulate the parasite genome, and to do that at a scale that allows us to ask questions about the functions of many genes, or even the entire genome, in a variety of contexts,” Lourido says.
There are drugs that can treat the acute symptoms of Toxoplasma infection, which include headache, fever, and inflammation of the heart and lungs. However, once the parasite enters the dormant stage, those drugs don’t affect it. Lourido hopes that his lab’s work will lead to potential new treatments for this stage, as well as drugs that could combat similar parasites such as a tickborne parasite known as Babesia, which is becoming more common in New England.
“There are a lot of people who are affected by these parasites, and parasitology often doesn’t get the attention that it deserves at the highest levels of research. It’s really important to bring the latest scientific advances, the latest tools, and the latest concepts to the field of parasitology,” Lourido says.
A fascination with microbiology
As a child in Cali, Colombia, Lourido was enthralled by what he could see through the microscopes at his mother’s medical genetics lab at the University of Valle del Cauca. His father ran the family’s farm and also worked in government, at one point serving as interim governor of the state.
“From my mom, I was exposed to the ideas of gene expression and the influence of genetics on biology, and I think that really sparked an early interest in understanding biology at a fundamental level,” Lourido says. “On the other hand, my dad was in agriculture, and so there were other influences there around how the environment shapes biology.”
Lourido decided to go to college in the United States, in part because at the time, in the early 2000s, Colombia was experiencing a surge in violence. He was also drawn to the idea of attending a liberal arts college, where he could study both science and art. He ended up going to Tulane University, where he double-majored in fine arts and cell and molecular biology.
As an artist, Lourido focused on printmaking and painting. One area he especially enjoyed was stone lithography, which involves etching images on large blocks of limestone with oil-based inks, treating the images with chemicals, and then transferring the images onto paper using a large press.
“I ended up doing a lot of printmaking, which I think attracted me because it felt like a mode of expression that leveraged different techniques and technical elements,” he says.
At the same time, he worked in a biology lab that studied Daphnia, tiny crustaceans found in fresh water that have helped scientists learn about how organisms can develop new traits in response to changes to their environment. As an undergraduate, he helped develop ways to use viruses to introduce new genes into Daphnia. By the time he graduated from Tulane, Lourido had decided to go into science rather than art.
“I had really fallen in love with lab science as an undergrad. I loved the freedom and the creativity that came from it, the ability to work in teams and to build on ideas, to not have to completely reinvent the entire system, but really be able to develop it over a longer period of time,” he says.
After graduating from college, Lourido spent two years in Germany, working at the Max Planck Institute for Infection Biology. In Arturo Zychlinksy’s lab, Lourido studied two bacteria known as Shigella and Salmonella, which can cause severe illnesses, including diarrhea. His studies there helped to reveal how these bacteria get into cells and how they modify the host cells’ own pathways to help them replicate inside cells.
As a graduate student at Washington University in St. Louis, Lourido worked in several labs focusing on different aspects of microbiology, including virology and bacteriology, but eventually ended up working with David Sibley, a prominent researcher specializing in Toxoplasma.
“I had not thought much about Toxoplasma before going to graduate school,” Lourido recalls. “I was pretty unaware of parasitology in general, despite some undergrad courses, which honestly very superficially treated the subject. What I liked about it was here was a system where we knew so little — organisms that are so different from the textbook models of eukaryotic cells.”
Toxoplasma gondii belongs to a group of parasites known as apicomplexans — a type of protozoans that can cause a variety of diseases. After infecting a human host, Toxoplasma gondii can hide from the immune system for decades, usually in cysts found in the brain or muscles. Lourido found the organism especially intriguing because as a 17-year-old, he had been diagnosed with toxoplasmosis. His only symptom was swollen glands, but doctors found that his blood contained antibodies against Toxoplasma.
“It is really fascinating that in all of these people, about a quarter to a third of the world’s population, the parasite persists. Chances are I still have live parasites somewhere in my body, and if I became immunocompromised, it would become a big problem. They would start replicating in an uncontrolled fashion,” he says.
A transformative approach
One of the challenges in studying Toxoplasma is that the organism’s genetics are very different from those of either bacteria or other eukaryotes such as yeast and mammals. That makes it harder to study parasitic gene functions by mutating or knocking out the genes.
Because of that difficulty, it took Lourido his entire graduate career to study the functions of just a couple of Toxoplasma genes. After finishing his PhD, he started his own lab as a fellow at the Whitehead Institute and began working on ways to study the Toxoplasma genome at a larger scale, using the CRISPR genome-editing technique.
With CRISPR, scientists can systematically knock out every gene in the genome and then study how each missing gene affects parasite function and survival.
“Through the adaptation of CRISPR to Toxoplasma, we’ve been able to survey the entire parasite genome. That has been transformative,” says Lourido, who became a Whitehead member and MIT faculty member in 2017. “Since its original application in 2016, we’ve been able to uncover mechanisms of drug resistance and susceptibility, trace metabolic pathways, and explore many other aspects of parasite biology.”
Using CRISPR-based screens, Lourido’s lab has identified a regulatory gene called BFD1 that appears to drive the expression of genes that the parasite needs for long-term survival within a host. His lab has also revealed many of the molecular steps required for the parasite to shift between active and dormant states.
“We’re actively working to understand how environmental inputs end up guiding the parasite in one direction or another,” Lourido says. “They seem to preferentially go into those chronic stages in certain cells like neurons or muscle cells, and they proliferate more exuberantly in the acute phase when nutrient conditions are appropriate or when there are low levels of immunity in the host.”
Uphill battles: Across the country in 75 daysAmulya Aluru ’23, MEng ’24 and the MIT Spokes have spent the summer spreading science, over 3,000 miles on two wheels.Amulya Aluru ’23, MEng ’24, will head to the University of California at Berkeley for a PhD in molecular and cell biology PhD this fall. Aluru knows her undergraduate 6-7 major and MEng program, where she worked on a computational project in a biology lab, have prepared her for the next step of her academic journey.
“I’m a lot more comfortable with the unknown in terms of research — and also life,” she says. “While I’ve enjoyed what I’ve done so far, I think it’s equally valuable to try and explore new topics. I feel like there’s still a lot more for me to learn in biology.”
Unlike many of her peers, however, Aluru won’t reach the San Francisco Bay Area by car, plane, or train. She will arrive by bike — a journey she began in Washington just a few days after receiving her master’s degree.
Showing that science is accessible
Spokes is an MIT-based nonprofit that each year sends students on a transcontinental bike ride. Aluru worked for months with seven fellow MIT students on logistics and planning. Since setting out, the team has bonded over their love of memes and cycling-themed nicknames: Hank “Handlebar Hank” Stennes, Clelia “Climbing Cleo” Lacarriere, Varsha “Vroom Vroom Varsha” Sandadi, Rebecca “Railtrail Rebecca” Lizarde, JD “JDerailleur Hanger” Hagood, Sophia “Speedy Sophia” Wang, Amulya “Aero Amulya” Aluru, and Jessica “Joyride Jess” Xu. The support minivan, carrying food, luggage, and occasionally injured or sick cyclists, even earned its own nickname: “Chrissy”, short for Chrysler Pacifica.
“I really wanted to do something to challenge myself, but not in a strictly academic sense,” Aluru says of her decision to join the team and bike more than 3,000 miles this summer.
The Spokes team is not biking across the country solely to accomplish such a feat. Throughout their journey, they’ll be offering a variety of science demonstrations, including making concrete with Rice Krispies, demonstrating the physics of sound, using 3D printers, and, in Aluru’s case, extracting DNA from strawberries.
“We’re going to be in a lot of really different learning environments,” she says. “I hope to demonstrate that science can be accessible, even if you don’t have a lab at your disposal.”
These demonstrations have been held in venues such as a D.C. jail, a space camp, and libraries and youth centers across the country; their learning festivals were even featured on a local news channel in Kentucky.
Some derailments
The team was beset with challenges from the first day they started their journey. Aluru’s first day on the road involved driving to every bike shop and REI store in the D.C. metro area to purchase bike computers for navigation because the ones the team had already purchased would only display maps of Europe.
Four days in and four Chrysler Pacificas later — the first was unsafe due to bald tires, the second made a weird sound as they pulled out of the rental lot, and the third’s gas pedal stopped working over 50 miles away from the nearest rental agency — the team was back together again in Waynesboro, Virginia, for the first time since they’d set out.
Since then, they’ve had run-ins with local fauna — including mean dogs and a meaner turtle — attempted to repair a tubeless bike that was not, in fact, tubeless, and slept in Chrissy the minivan after their tents got soaked and blew away.
Although it hasn’t all been smooth riding, the team has made time for fun. They’ve perfected the art of eating a Clif bar while on two wheels, played around on monkey bars in Colorado, met up with Stanford Spokes, enjoyed pounds of ice cream, and downed gallons of lattes.
The team prioritized routes on bike trails, rather than highways, as much as possible. Their teaching activities are scheduled between visits to National Parks like Tahoe, Zion, Bryce Canyon, Arches, and touring and hiking places like Breaks Interstate Park, Mammoth Cave, and the Collegiate Peaks.
Aluru says she’s excited to see parts of the country she’s never visited before, and experience the terrain under her own power — except for breaks when it’s her turn to drive Chrissy.
Rolling with the ups and downs
Aluru was only a few weeks into her first Undergraduate Research Opportunities Program project in the late professor Angelika Amon’s lab when the Covid-19 pandemic hit, quickly transforming her wet lab project into a computational one. David Waterman, her postdoc mentor in the Amon Lab, was trained as a biologist, not a computational scientist. Luckily, Aluru had just taken two computer science classes.
“I was able to have a big hand in formulating my project and bouncing ideas off of him,” she recalls. “That helped me think about scientific questions, which I was able to apply when I came back to campus and started doing wet lab research again.”
When Aluru returned to campus, she began work in the Page Lab at the Whitehead Institute for Biomedical Research. She continued working there for the rest of her time at MIT, first as an undergraduate student and then as an MEng student.
The Page Lab’s work primarily concerns sex differences and how those differences play out in genetics, development, and disease — and the Department of Electronic Engineering and Computer Science, which oversees the MEng program, allows students to pursue computational projects across disciplines, no matter the department.
For her MEng work, Aluru looked at sex differences in human height, a continuation of a paper that the Page Lab published in 2019. Height is an easily observable human trait and, from previous research, is known to be sex-biased across at least five species. Genes that have sex-biased expression patterns, or expression patterns that are higher or lower in males compared to females, may play a role in establishing or maintaining these sex differences. Through statistical genetics, Aluru replicated the findings of the earlier paper and expanded them using newly published datasets.
“Amulya has had an amazing journey in our department,” says David Page, professor of biology and core member of the Whitehead Institute. “There is simply no stopping her insatiable curiosity and zest for life.”
Working with the lab as a graduate student came with more day-to-day responsibility and independence than when she was an undergrad.
“It was a shift I quite appreciated,” Aluru says. “At times it was challenging, but I think it was a good challenge: learning how to structure my research on my own, while still getting a lot of support from lab members and my PI [principal investigator].”
Gearing up for the future
Since departing MIT, Aluru and the rest of the Spokes team have spent their nights camping, sleeping in churches, and staying with hosts. They enjoyed the longest day of the year in a surprisingly “Brooklyn chic” house, spent a lazy afternoon on a river, and pinky-promised to be in each other’s weddings. The team has also been hosted by, met up with, and run into MIT alums as they’ve crossed the country.
As Aluru looks to the future, she admits she’s not exactly sure what she’ll study — but when she reaches the West Coast, she knows she’s not leaving what she’s built through MIT far behind.
“There’s going to be a small MIT community even there — a lot of my friends are in San Francisco, and a few people I know are also going to be at Berkeley,” she says. “I have formed a community at MIT that I know will support me in all my future endeavors.”
Study reveals the benefits and downside of fastingFasting helps intestinal stem cells regenerate and heal injuries but also leads to a higher risk of cancer in mice, MIT researchers report.Low-calorie diets and intermittent fasting have been shown to have numerous health benefits: They can delay the onset of some age-related diseases and lengthen lifespan, not only in humans but many other organisms.
Many complex mechanisms underlie this phenomenon. Previous work from MIT has shown that one way fasting exerts its beneficial effects is by boosting the regenerative abilities of intestinal stem cells, which helps the intestine recover from injuries or inflammation.
In a study of mice, MIT researchers have now identified the pathway that enables this enhanced regeneration, which is activated once the mice begin “refeeding” after the fast. They also found a downside to this regeneration: When cancerous mutations occurred during the regenerative period, the mice were more likely to develop early-stage intestinal tumors.
“Having more stem cell activity is good for regeneration, but too much of a good thing over time can have less favorable consequences,” says Omer Yilmaz, an MIT associate professor of biology, a member of MIT’s Koch Institute for Integrative Cancer Research, and the senior author of the new study.
Yilmaz adds that further studies are needed before forming any conclusion as to whether fasting has a similar effect in humans.
“We still have a lot to learn, but it is interesting that being in either the state of fasting or refeeding when exposure to mutagen occurs can have a profound impact on the likelihood of developing a cancer in these well-defined mouse models,” he says.
MIT postdocs Shinya Imada and Saleh Khawaled are the lead authors of the paper, which appears today in Nature.
Driving regeneration
For several years, Yilmaz’s lab has been investigating how fasting and low-calorie diets affect intestinal health. In a 2018 study, his team reported that during a fast, intestinal stem cells begin to use lipids as an energy source, instead of carbohydrates. They also showed that fasting led to a significant boost in stem cells’ regenerative ability.
However, unanswered questions remained: How does fasting trigger this boost in regenerative ability, and when does the regeneration begin?
“Since that paper, we’ve really been focused on understanding what is it about fasting that drives regeneration,” Yilmaz says. “Is it fasting itself that’s driving regeneration, or eating after the fast?”
In their new study, the researchers found that stem cell regeneration is suppressed during fasting but then surges during the refeeding period. The researchers followed three groups of mice — one that fasted for 24 hours, another one that fasted for 24 hours and then was allowed to eat whatever they wanted during a 24-hour refeeding period, and a control group that ate whatever they wanted throughout the experiment.
The researchers analyzed intestinal stem cells’ ability to proliferate at different time points and found that the stem cells showed the highest levels of proliferation at the end of the 24-hour refeeding period. These cells were also more proliferative than intestinal stem cells from mice that had not fasted at all.
“We think that fasting and refeeding represent two distinct states,” Imada says. “In the fasted state, the ability of cells to use lipids and fatty acids as an energy source enables them to survive when nutrients are low. And then it’s the postfast refeeding state that really drives the regeneration. When nutrients become available, these stem cells and progenitor cells activate programs that enable them to build cellular mass and repopulate the intestinal lining.”
Further studies revealed that these cells activate a cellular signaling pathway known as mTOR, which is involved in cell growth and metabolism. One of mTOR’s roles is to regulate the translation of messenger RNA into protein, so when it’s activated, cells produce more protein. This protein synthesis is essential for stem cells to proliferate.
The researchers showed that mTOR activation in these stem cells also led to production of large quantities of polyamines — small molecules that help cells to grow and divide.
“In the refed state, you’ve got more proliferation, and you need to build cellular mass. That requires more protein, to build new cells, and those stem cells go on to build more differentiated cells or specialized intestinal cell types that line the intestine,” Khawaled says.
Too much of a good thing
The researchers also found that when stem cells are in this highly regenerative state, they are more prone to become cancerous. Intestinal stem cells are among the most actively dividing cells in the body, as they help the lining of the intestine completely turn over every five to 10 days. Because they divide so frequently, these stem cells are the most common source of precancerous cells in the intestine.
In this study, the researchers discovered that if they turned on a cancer-causing gene in the mice during the refeeding stage, they were much more likely to develop precancerous polyps than if the gene was turned on during the fasting state. Cancer-linked mutations that occurred during the refeeding state were also much more likely to produce polyps than mutations that occurred in mice that did not undergo the cycle of fasting and refeeding.
“I want to emphasize that this was all done in mice, using very well-defined cancer mutations. In humans it’s going to be a much more complex state,” Yilmaz says. “But it does lead us to the following notion: Fasting is very healthy, but if you’re unlucky and you’re refeeding after a fasting, and you get exposed to a mutagen, like a charred steak or something, you might actually be increasing your chances of developing a lesion that can go on to give rise to cancer.”
Yilmaz also noted that the regenerative benefits of fasting could be significant for people who undergo radiation treatment, which can damage the intestinal lining, or other types of intestinal injury. His lab is now studying whether polyamine supplements could help to stimulate this kind of regeneration, without the need to fast.
“This fascinating study provides insights into the complex interplay between food consumption, stem cell biology, and cancer risk,” says Ophir Klein, a professor of medicine at the University of California at San Francisco and Cedars-Sinai Medical Center, who was not involved in the study. “Their work lays a foundation for testing polyamines as compounds that may augment intestinal repair after injuries, and it suggests that careful consideration is needed when planning diet-based strategies for regeneration to avoid increasing cancer risk.”
The research was funded, in part, by Pew-Stewart Scholars Program for Cancer Research award, the MIT Stem Cell Initiative, the Koch Institute Frontier Research Program via the Kathy and Curt Marble Cancer Research Fund, and the Bridge Project, a partnership between the Koch Institute for Integrative Cancer Research at MIT and the Dana-Farber/Harvard Cancer Center.
MIT study explains why laws are written in an incomprehensible styleThe convoluted “legalese” used in legal documents conveys a special sense of authority, and even non-lawyers have learned to wield it.Legal documents are notoriously difficult to understand, even for lawyers. This raises the question: Why are these documents written in a style that makes them so impenetrable?
MIT cognitive scientists believe they have uncovered the answer to that question. Just as “magic spells” use special rhymes and archaic terms to signal their power, the convoluted language of legalese acts to convey a sense of authority, they conclude.
In a study appearing this week in the journal of the Proceedings of the National Academy of Sciences, the researchers found that even non-lawyers use this type of language when asked to write laws.
“People seem to understand that there’s an implicit rule that this is how laws should sound, and they write them that way,” says Edward Gibson, an MIT professor of brain and cognitive sciences and the senior author of the study.
Eric Martinez PhD ’24 is the lead author of the study. Francis Mollica, a lecturer at the University of Melbourne, is also an author of the paper.
Casting a legal spell
Gibson’s research group has been studying the unique characteristics of legalese since 2020, when Martinez came to MIT after earning a law degree from Harvard Law School. In a 2022 study, Gibson, Martinez, and Mollica analyzed legal contracts totaling about 3.5 million words, comparing them with other types of writing, including movie scripts, newspaper articles, and academic papers.
That analysis revealed that legal documents frequently have long definitions inserted in the middle of sentences — a feature known as “center-embedding.” Linguists have previously found that this kind of structure can make text much more difficult to understand.
“Legalese somehow has developed this tendency to put structures inside other structures, in a way which is not typical of human languages,” Gibson says.
In a follow-up study published in 2023, the researchers found that legalese also makes documents more difficult for lawyers to understand. Lawyers tended to prefer plain English versions of documents, and they rated those versions to be just as enforceable as traditional legal documents.
“Lawyers also find legalese to be unwieldy and complicated,” Gibson says. “Lawyers don’t like it, laypeople don’t like it, so the point of this current paper was to try and figure out why they write documents this way.”
The researchers had a couple of hypotheses for why legalese is so prevalent. One was the “copy and edit hypothesis,” which suggests that legal documents begin with a simple premise, and then additional information and definitions are inserted into already existing sentences, creating complex center-embedded clauses.
“We thought it was plausible that what happens is you start with an initial draft that’s simple, and then later you think of all these other conditions that you want to include. And the idea is that once you’ve started, it’s much easier to center-embed that into the existing provision,” says Martinez, who is now a fellow and instructor at the University of Chicago Law School.
However, the findings ended up pointing toward a different hypothesis, the so-called “magic spell hypothesis.” Just as magic spells are written with a distinctive style that sets them apart from everyday language, the convoluted style of legal language appears to signal a special kind of authority, the researchers say.
“In English culture, if you want to write something that’s a magic spell, people know that the way to do that is you put a lot of old-fashioned rhymes in there. We think maybe center-embedding is signaling legalese in the same way,” Gibson says.
In this study, the researchers asked about 200 non-lawyers (native speakers of English living in the United States, who were recruited through a crowdsourcing site called Prolific), to write two types of texts. In the first task, people were told to write laws prohibiting crimes such as drunk driving, burglary, arson, and drug trafficking. In the second task, they were asked to write stories about those crimes.
To test the copy and edit hypothesis, half of the participants were asked to add additional information after they wrote their initial law or story. The researchers found that all of the subjects wrote laws with center-embedded clauses, regardless of whether they wrote the law all at once or were told to write a draft and then add to it later. And, when they wrote stories related to those laws, they wrote in much plainer English, regardless of whether they had to add information later.
“When writing laws, they did a lot of center-embedding regardless of whether or not they had to edit it or write it from scratch. And in that narrative text, they did not use center-embedding in either case,” Martinez says.
In another set of experiments, about 80 participants were asked to write laws, as well as descriptions that would explain those laws to visitors from another country. In these experiments, participants again used center-embedding for their laws, but not for the descriptions of those laws.
The origins of legalese
Gibson’s lab is now investigating the origins of center-embedding in legal documents. Early American laws were based on British law, so the researchers plan to analyze British laws to see if they feature the same kind of grammatical construction. And going back much farther, they plan to analyze whether center-embedding is found in the Hammurabi Code, the earliest known set of laws, which dates to around 1750 BC.
“There may be just a stylistic way of writing from back then, and if it was seen as successful, people would use that style in other languages,” Gibson says. “I would guess that it’s an accidental property of how the laws were written the first time, but we don’t know that yet.”
The researchers hope that their work, which has identified specific aspects of legal language that make it more difficult to understand, will motivate lawmakers to try to make laws more comprehensible. Efforts to write legal documents in plainer language date to at least the 1970s, when President Richard Nixon declared that federal regulations should be written in “layman’s terms.” However, legal language has changed very little since that time.
“We have learned only very recently what it is that makes legal language so complicated, and therefore I am optimistic about being able to change it,” Gibson says.
When the lights turned on in the universeBy studying ancient, supermassive black holes called quasars, Dominika Ďurovčíková is illuminating an early moment when galaxies could first be observed.Watching crowds of people hustle along Massachusetts Avenue from her window seat in MIT’s student center, Dominika Ďurovčíková has just one wish.
“What I would really like to do is convince a city to shut down their lights completely, apart from hospitals or whatever else needs them, just for an hour,” she says. “Let people see the Milky Way, or the stars. It influences you. You realize there’s something more than your everyday struggles.”
Even with a lifetime of gazing into the cosmos under her belt — with the last few years spent pursuing a PhD with professors Anna-Christina Eilers and Robert Simcoe at MIT’s Kavli Institute for Astrophysics and Space Research — she still believes in the power of looking up at the night sky with the naked eye.
Most of the time, however, she’s using tools a lot more powerful than that. The James Webb Space Telescope has begun providing rich data from bodies at the very edge of the universe, exactly where she wants to be looking. With data from the JSWT and the ground-based Magellan telescopes in Chile, Ďurovčíková is on the hunt for distant quasars — ancient, supermassive black holes that emit intense amounts of light — and the farther away they are, the more information they provide about the very early universe.
“These objects are really, really bright, and that means that they’re really useful for studying the universe from very far away,” she says. “They’re like beacons from the past that you can still see, and they can tell you something about the universe at that stage. It’s almost like archaeology.”
Her recent research has focused on what’s known as the Epoch of Reionization. It’s the period of time when the radiation from quasars, stars, galaxies and other light-emitting bodies were able to penetrate through the dark clouds of hydrogen atoms left over from the Big Bang, and shine their light through space.
“Reionization was a phase transition where all the stuff around galaxies suddenly became transparent,” she says. “Finally, we could see light that was otherwise absorbed by neutral hydrogen.”
One of her goals is to help discover what caused the reionization process to start in the first place. While the astrophysical community has determined a loose time frame, there are many unanswered questions surrounding the Epoch of Reionization, and she hopes her quasar research can help solve some of them.
“The grand hope is that if you know the timing of reionization, that can inform you about the sources that caused it in the first place,” she says. “We’re not quite there, but looking at quasars could be a way to do it.”
Time and distance on a cosmic scale
The quasars that Ďurovčíková has been most interested in are classified as “high-redshift.” Redshift is a measure of how much a wave’s frequency has decreased, and in an astrophysical context, it can be used to determine how long a wave of light has been traveling and how far away its source is, while accounting for the expansion of the universe.
“The higher the redshift, the closer to the beginning of the universe you get,” Ďurovčíková explains.
Research has shown that reionization began roughly 150 million years after the Big Bang, and approximately 850 million years after that, the dark hydrogen clouds that made up the “intergalactic medium,” or IGM, were fully ionized.
For her most recent paper, Ďurovčíková examined a set of 18 quasars whose light began traveling between approximately 770 million and 950 million years after the Big Bang. She and her collaborators, including scientists from four different countries, sorted the quasars into three “bins” based on distance, to compare the amount of neutral hydrogen in the IGM at different epochs. These amounts helped refine the timing of reionization and confirmed that data from quasars are consistent with data from other types of bodies.
“The story we have so far,” Ďurovčíková says, “is that at some point by redshift 5 or 6, the stuff in between galaxies was overall ionized. However, it’s not clear what type of star or what type of galaxy is more responsible for this global phase transition, which affected the whole universe.”
A closely related facet of her research — and one she’s planning on exploring further as she composes her thesis — is on how these quasars came to be in the first place. They’re so old, and so massive, that they challenge the current conceptions of how old the universe is. The light they generate comes from the immense gravitational force they exert on the plasma they absorb, and if they were already large enough to do that billions of years ago, just how long ago did they start forming?
“These black holes seem to be too massive to be grown in the time that their spectra seem to indicate,” she says. “Is there something in our way that’s obscuring the rest of the growth? We’re looking at different methods to measure their lifetime.”
Eyes towards the stars, feet grounded on Earth
In the meantime, Ďurovčíková is also working to encourage the next generation of astrophysicists. She says she was fortunate to have encouraging parents and mentors who showed her academic and career paths she hadn’t even considered, and she co-founded a nonprofit organization called Encouraging Women Across All Borders to do the same for students across the globe.
“In your life, you will see a lot of doors,” she says. “There’s doors that you’ll see are open, and there’s doors you’ll see are closed. The biggest tragedy, though, is that there are so many doors that you don’t even know exist.”
She knows the feeling all too well. Growing up in Slovakia meant the primary options were attending university in either Bratislava, the capital, or Prague, in the neighboring Czech Republic. Her love of math and physics inspired her to enroll in the International Baccalaureate program, however, and it was in that program that she met a teacher, named Eva Žitná, who “planted the seeds” that eventually sent her to Oxford for a four-year master’s program.
“Just being in the IB program environment started to open up these possibilities I had not considered before,” she says. “Both my parents and I started talking to Žitná about how this could be an interesting possibility, and somehow one thing led to another.”
While she takes great pleasure in guiding students along the same path she once took, equally as rewarding for her are the moments when she can see people realizing just how big the universe is. As a co-director of the MIT Astrogazers, she has witnessed many such moments. She remembers handing out eclipse glasses at the Cambridge Science Festival in preparation for last October’s partial solar eclipse, and recalls kids and adults alike with their necks craned upward, sharing the same look of wonder on their faces.
“The reason I care is because we all get caught up in small things in life very easily,” she says. “The traffic sucks. The T isn’t working. Then, you look up at the sky and you realize there’s something much more beautiful and much bigger than all these little things.”
Building bidirectional bridgesMIT’s Office of Graduate Education hosts Summit on Creating Inclusive Pathways to the PhDIn June 2023, after the U.S. Supreme Court ruled that colleges and universities could no longer use race as a factor in their admission decisions, many higher education institutions across the United States faced the same challenge: how to maintain diversity in their student bodies. So Noelle Wakefield, director of MIT’s Summer Research Program (MSRP) and assistant dean for diversity initiatives in MIT’s Office of Graduate Education (OGE), started planning.
On July 31, a little more than a year after the decision was released, the OGE hosted the inaugural Inclusive Pathways to the PhD Summit, which brought representatives from nearly 20 minority-serving institutions (MSIs), including several historically Black colleges and universities (HBCUs), to Cambridge, Massachusetts, to meet with MIT administrators, faculty, and doctoral students. The admission question — how to continue attracting a diverse cohort of graduate students with the new legal restrictions? — was only the first of many that framed a broader and more complex picture.
“What are fresh ways for us to find talent in places that aren’t typically represented at MIT?” Wakefield asks. “How can we form partnerships with institutions that aren’t already part of our ecosystem? What is the formula for partnerships where both institutions benefit and feel good about the work that is happening?”
These aren’t new outreach questions for MIT, Wakefield says, but the changing admissions landscape sparked a need for the Institute to “be more thoughtful.”
And a need to clear up misperceptions, adds Denzil Streete, senior associate dean and director of the OGE. “MIT faculty may have outdated perspectives about HBCUs and MSIs,” he says. “And our visitors may be relying on historical knowledge of MIT that is largely negative” when it comes to attracting graduate applications from smaller, lesser-known colleges and universities. The summit was designed to be a first step in demystifying these assumptions and in establishing “a common platform and a shared understanding for moving forward,” Streete says.
For decades, the OGE has focused its HBCU and MSI outreach efforts on student recruitment, but the summit signals a broadening of that approach to include faculty and staff mentors — the people Wakefield describes as “levers for decision-making” among prospective graduate students. Streete says, “if we at MIT say we attract the best and brightest in the world and we don’t include these institutions, then our supposition comes into question.”
The summit agenda included information sessions about navigating the MIT graduate admission process and finding research opportunities for undergraduates, as well as conversations with current MIT doctoral students who’d graduated from the MSIs represented at the summit. There was a campus tour, a poster session by students in the MIT Summer Research Program, and a panel discussion on forming reciprocal relationships with HBCUs and MSIs, featuring visitors from Spelman College, Prairie View A & M University, and the University of Puerto Rico, among others.
That discussion resonated with visitor Gwendolyn Scott-Jones, dean of the Wesley College of Health and Behavioral Sciences at Delaware State University. “It felt like an authentic discussion about the disparities and lack of equal resources that HBCUs historically contend with compared to predominantly white institutions,” she observes. “HBCUs have been known to do more with less and have produced very talented professionals, and I believe MIT is trying to provide HBCUs with access and opportunity.”
One of the summit’s goals was to begin ensuring that this access and opportunity would be “bidirectional” — going both ways between an institution like MIT and an HCBU like Lincoln University in Pennsylvania, where Christina Chisholm, one of the panelists, did her undergraduate work. Collaborations “aren’t spaces in which you’re just throwing money at something to fix it, or to bridge a gap,” says Chisholm, a biophysicist who’s now director of the McNair Scholars Program and Thrive Student Support Services at Rutgers University.
Instead, she advised, focus on cooperation, coordination, and positive mentorship. Tiffany Oliver, a biology professor at Spelman, recalled a potential student-research project she was exploring with a partner at a larger institution who would host her students in his lab. “His attitude was, ‘We have the money so we’re going to tell you what you need to do.’” she recalls. “That’s a reflection of how you’re going to treat my students, and I would rather send my students to some other place if the people show that they care. I want my students to leave school still loving science, not tarnished by science.”
Another piece of advice came from Kareem McLemore, assistant vice president of strategic enrollment management at Delaware State. “When you’re partnering with us, the first thing we’re going to ask is, ‘Are you doing this to check a box?’” he says. “If it’s a checkbox, we don’t want it. We want to know what the objectives are, the key goals, the KPIs [key performance indicators]. You may have the money, but think about the resources we have as HBCUs that can help you raise your brand. We have to ride the wave together.”
The summit served as a starting point: a way to build trust among institutions with different histories and resources, and to stimulate ideas for future partnerships, whether that means a joint research project, a shared curriculum, or a faculty exchange.
“We all understand that talent is everywhere but opportunity is not distributed in the same manner,” says Bryan Thomas Jr., assistant dean for diversity, equity, and inclusion at the MIT Sloan School of Management and a co-organizer of the event. Broadening MIT’s networks through the Inclusive Pathways Summit means “expanding our ecosystem of opportunity, collaboration, and adding new ways of solving problems,” he says. “And that ultimately benefits all of us.”
Study: Rocks from Mars’ Jezero Crater, which likely predate life on Earth, contain signs of waterThe presence of organic matter is inconclusive, but the rocks could be scientists’ best chance at finding remnants of ancient Martian life.In a new study appearing today in the journal AGU Advances, scientists at MIT and NASA report that seven rock samples collected along the “fan front” of Mars’ Jezero Crater contain minerals that are typically formed in water. The findings suggest that the rocks were originally deposited by water, or may have formed in the presence of water.
The seven samples were collected by NASA’s Perseverance rover in 2022 during its exploration of the crater’s western slope, where some rocks were hypothesized to have formed in what is now a dried-up ancient lake. Members of the Perseverance science team, including MIT scientists, have studied the rover’s images and chemical analyses of the samples, and confirmed that the rocks indeed contain signs of water, and that the crater was likely once a watery, habitable environment.
Whether the crater was actually inhabited is yet unknown. The team found that the presence of organic matter — the starting material for life — cannot be confirmed, at least based on the rover’s measurements. But judging from the rocks’ mineral content, scientists believe the samples are their best chance of finding signs of ancient Martian life once the rocks are returned to Earth for more detailed analysis.
“These rocks confirm the presence, at least temporarily, of habitable environments on Mars,” says the study’s lead author, Tanja Bosak, professor of geobiology in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). “What we’ve found is that indeed there was a lot of water activity. For how long, we don’t know, but certainly for long enough to create these big sedimentary deposits.”
What’s more, some of the collected samples may have originally been deposited in the ancient lake more than 3.5 billion years ago — before even the first signs of life on Earth.
“These are the oldest rocks that may have been deposited by water, that we’ve ever laid hands or rover arms on,” says co-author Benjamin Weiss, the Robert R. Shrock Professor of Earth and Planetary Sciences at MIT. “That’s exciting, because it means these are the most promising rocks that may have preserved fossils, and signatures of life.”
The study’s MIT co-authors include postdoc Eva Scheller, and research scientist Elias Mansbach, along with members of the Perseverance science team.
At the front
The new rock samples were collected in 2022 as part of the rover’s Fan Front Campaign — an exploratory phase during which Perseverance traversed Jezero Crater’s western slope, where a fan-like region contains sedimentary, layered rocks. Scientists suspect that this “fan front” is an ancient delta that was created by sediment that flowed with a river and settled into a now bone-dry lakebed. If life existed on Mars, scientists believe that it could be preserved in the layers of sediment along the fan front.
In the end, Perseverance collected seven samples from various locations along the fan front. The rover obtained each sample by drilling into the Martian bedrock and extracting a pencil-sized core, which it then sealed in a tube to one day be retrieved and returned to Earth for detailed analysis.
Prior to extracting the cores, the rover took images of the surrounding sediments at each of the seven locations. The science team then processed the imaging data to estimate a sediment’s average grain size and mineral composition. This analysis showed that all seven collected samples likely contain signs of water, suggesting that they were initially deposited by water.
Specifically, Bosak and her colleagues found evidence of certain minerals in the sediments that are known to precipitate out of water.
“We found lots of minerals like carbonates, which are what make reefs on Earth,” Bosak says. “And it’s really an ideal material that can preserve fossils of microbial life.”
Interestingly, the researchers also identified sulfates in some samples that were collected at the base of the fan front. Sulfates are minerals that form in very salty water — another sign that water was present in the crater at one time — though very salty water, Bosak notes, “is not necessarily the best thing for life.” If the entire crater was once filled with very salty water, then it would be difficult for any form of life to thrive. But if only the bottom of the lake were briny, that could be an advantage, at least for preserving any signs of life that may have lived further up, in less salty layers, that eventually died and drifted down to the bottom.
“However salty it was, if there were any organics present, it's like pickling something in salt,” Bosak says. “If there was life that fell into the salty layer, it would be very well-preserved.”
Fuzzy fingerprints
But the team emphasizes that organic matter has not been confidently detected by the rover’s instruments. Organic matter can be signs of life, but can also be produced by certain geological processes that have nothing to do with living matter. Perseverance’s predecessor, the Curiosity rover, had detected organic matter throughout Mars’ Gale Crater, which scientists suspect may have come from asteroids that made impact with Mars in the past.
And in a previous campaign, Perseverance detected what appeared to be organic molecules at multiple locations along Jezero Crater’s floor. These observations were taken by the rover’s Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument, which uses ultraviolet light to scan the Martian surface. If organics are present, they can glow, similar to material under a blacklight. The wavelengths at which the material glows act as a sort of fingerprint for the kind of organic molecules that are present.
In Perseverance’s previous exploration of the crater floor, SHERLOC appeared to pick up signs of organic molecules throughout the region, and later, at some locations along the fan front. But a careful analysis, led by MIT’s Eva Scheller, has found that while the particular wavelengths observed could be signs of organic matter, they could just as well be signatures of substances that have nothing to do with organic matter.
“It turns out that cerium metals incorporated in minerals actually produce very similar signals as the organic matter,” Scheller says. “When investigated, the potential organic signals were strongly correlated with phosphate minerals, which always contain some cerium.”
Scheller’s work shows that the rover’s measurements cannot be interpreted definitively as organic matter.
“This is not bad news,” Bosak says. “It just tells us there is not very abundant organic matter. It’s still possible that it’s there. It’s just below the rover’s detection limit.”
When the collected samples are finally sent back to Earth, Bosak says laboratory instruments will have more than enough sensitivity to detect any organic matter that might lie within.
“On Earth, once we have microscopes with nanometer-scale resolution, and various types of instruments that we cannot staff on one rover, then we can actually attempt to look for life,” she says.
This work was supported, in part, by NASA.
Study reveals ways in which 40Hz sensory stimulation may preserve brain’s “white matter”Gamma frequency light and sound stimulation preserves myelination in mouse models and reveals molecular mechanisms that may underlie the benefit.Early-stage trials in Alzheimer’s disease patients and studies in mouse models of the disease have suggested positive impacts on pathology and symptoms from exposure to light and sound presented at the “gamma” band frequency of 40 hertz (Hz). A new study zeroes in on how 40Hz sensory stimulation helps to sustain an essential process in which the signal-sending branches of neurons, called axons, are wrapped in a fatty insulation called myelin. Often called the brain’s “white matter,” myelin protects axons and insures better electrical signal transmission in brain circuits.
“Previous publications from our lab have mainly focused on neuronal protection,” says Li-Huei Tsai, Picower Professor in The Picower Institute for Learning and Memory and the Department of Brain and Cognitive Sciences at MIT and senior author of the new open-access study in Nature Communications. Tsai also leads MIT’s Aging Brain Initiative. “But this study shows that it’s not just the gray matter, but also the white matter that’s protected by this method.”
This year Cognito Therapeutics, the spinoff company that licensed MIT’s sensory stimulation technology, published phase II human trial results in the Journal of Alzheimer’s Disease indicating that 40Hz light and sound stimulation significantly slowed the loss of myelin in volunteers with Alzheimer’s. Also this year, Tsai’s lab published a study showing that gamma sensory stimulation helped mice withstand neurological effects of chemotherapy medicines, including by preserving myelin. In the new study, members of Tsai’s lab led by former postdoc Daniela Rodrigues Amorim used a common mouse model of myelin loss — a diet with the chemical cuprizone — to explore how sensory stimulation preserves myelination.
Amorim and Tsai’s team found that 40Hz light and sound not only preserved myelination in the brains of cuprizone-exposed mice, it also appeared to protect oligodendrocytes (the cells that myelinate neural axons), sustain the electrical performance of neurons, and preserve a key marker of axon structural integrity. When the team looked into the molecular underpinnings of these benefits, they found clear signs of specific mechanisms including preservation of neural circuit connections called synapses; a reduction in a cause of oligodendrocyte death called “ferroptosis;” reduced inflammation; and an increase in the ability of microglia brain cells to clean up myelin damage so that new myelin could be restored.
“Gamma stimulation promotes a healthy environment,” says Amorim, who is now a Marie Curie Fellow at the University of Galway in Ireland. “There are several ways we are seeing different effects.”
The findings suggest that gamma sensory stimulation may help not only Alzheimer’s disease patients but also people battling other diseases involving myelin loss, such as multiple sclerosis, the authors wrote in the study.
Maintaining myelin
To conduct the study, Tsai and Amorim’s team fed some male mice a diet with cuprizone and gave other male mice a normal diet for six weeks. Halfway into that period, when cuprizone is known to begin causing its most acute effects on myelination, they exposed some mice from each group to gamma sensory stimulation for the remaining three weeks. In this way they had four groups: completely unaffected mice, mice that received no cuprizone but did get gamma stimulation, mice that received cuprizone and constant (but not 40Hz) light and sound as a control, and mice that received cuprizone and also gamma stimulation.
After the six weeks elapsed, the scientists measured signs of myelination throughout the brains of the mice in each group. Mice that weren’t fed cuprizone maintained healthy levels, as expected. Mice that were fed cuprizone and didn’t receive 40Hz gamma sensory stimulation showed drastic levels of myelin loss. Cuprizone-fed mice that received 40Hz stimulation retained significantly more myelin, rivaling the health of mice never fed cuprizone by some, but not all, measures.
The researchers also looked at numbers of oligodendrocytes to see if they survived better with sensory stimulation. Several measures revealed that in mice fed cuprizone, oligodendrocytes in the corpus callosum region of the brain (a key point for the transit of neural signals because it connects the brain’s hemispheres) were markedly reduced. But in mice fed cuprizone and also treated with gamma stimulation, the number of cells were much closer to healthy levels.
Electrophysiological tests among neural axons in the corpus callosum showed that gamma sensory stimulation was associated with improved electrical performance in cuprizone-fed mice who received gamma stimulation compared to cuprizone-fed mice left untreated by 40Hz stimulation. And when researchers looked in the anterior cingulate cortex region of the brain, they saw that MAP2, a protein that signals the structural integrity of axons, was much better preserved in mice that received cuprizone and gamma stimulation compared to cuprizone-fed mice who did not.
A key goal of the study was to identify possible ways in which 40Hz sensory stimulation may protect myelin.
To find out, the researchers conducted a sweeping assessment of protein expression in each mouse group and identified which proteins were differentially expressed based on cuprizone diet and exposure to gamma frequency stimulation. The analysis revealed distinct sets of effects between the cuprizone mice exposed to control stimulation and cuprizone-plus-gamma mice.
A highlight of one set of effects was the increase in MAP2 in gamma-treated cuprizone-fed mice. A highlight of another set was that cuprizone mice who received control stimulation showed a substantial deficit in expression of proteins associated with synapses. The gamma-treated cuprizone-fed mice did not show any significant loss, mirroring results in a 2019 Alzheimer’s 40Hz study that showed synaptic preservation. This result is important, the researchers wrote, because neural circuit activity, which depends on maintaining synapses, is associated with preserving myelin. They confirmed the protein expression results by looking directly at brain tissues.
Another set of protein expression results hinted at another important mechanism: ferroptosis. This phenomenon, in which errant metabolism of iron leads to a lethal buildup of reactive oxygen species in cells, is a known problem for oligodendrocytes in the cuprizone mouse model. Among the signs was an increase in cuprizone-fed, control stimulation mice in expression of the protein HMGB1, which is a marker of ferroptosis-associated damage that triggers an inflammatory response. Gamma stimulation, however, reduced levels of HMGB1.
Looking more deeply at the cellular and molecular response to cuprizone demyelination and the effects of gamma stimulation, the team assessed gene expression using single-cell RNA sequencing technology. They found that astrocytes and microglia became very inflammatory in cuprizone-control mice but gamma stimulation calmed that response. Fewer cells became inflammatory and direct observations of tissue showed that microglia became more proficient at clearing away myelin debris, a key step in effecting repairs.
The team also learned more about how oligodendrocytes in cuprizone-fed mice exposed to 40Hz sensory stimulation managed to survive better. Expression of protective proteins such as HSP70 increased and as did expression of GPX4, a master regulator of processes that constrain ferroptosis.
In addition to Amorim and Tsai, the paper’s other authors are Lorenzo Bozzelli, TaeHyun Kim, Liwang Liu, Oliver Gibson, Cheng-Yi Yang, Mitch Murdock, Fabiola Galiana-Meléndez, Brooke Schatz, Alexis Davison, Md Rezaul Islam, Dong Shin Park, Ravikiran M. Raju, Fatema Abdurrob, Alissa J. Nelson, Jian Min Ren, Vicky Yang and Matthew P. Stokes.
Fundacion Bancaria la Caixa, The JPB Foundation, The Picower Institute for Learning and Memory, the Carol and Gene Ludwig Family Foundation, Lester A. Gimpelson, Eduardo Eurnekian, The Dolby Family, Kathy and Miguel Octavio, the Marc Haas Foundation, Ben Lenail and Laurie Yoler, and the U.S. National Institutes of Health provided funding for the study.
MIT chemists synthesize plant-derived molecules that hold potential as pharmaceuticalsLarge multi-ring-containing molecules known as oligocyclotryptamines have never been produced in the lab until now.MIT chemists have developed a new way to synthesize complex molecules that were originally isolated from plants and could hold potential as antibiotics, analgesics, or cancer drugs.
These compounds, known as oligocyclotryptamines, consist of multiple tricyclic substructures called cyclotryptamine, fused together by carbon–carbon bonds. Only small quantities of these compounds are naturally available, and synthesizing them in the lab has proven difficult. The MIT team came up with a way to add tryptamine-derived components to a molecule one at a time, in a way that allows the researchers to precisely assemble the rings and control the 3D orientation of each component as well as the final product.
“For many of these compounds, there hasn’t been enough material to do a thorough review of their potential. I’m hopeful that having access to these compounds in a reliable way will enable us to do further studies,” says Mohammad Movassaghi, an MIT professor of chemistry and the senior author of the new study.
In addition to allowing scientists to synthesize oligocyclotryptamines found in plants, this approach could also be used to generate new variants that may have even better medicinal properties, or molecular probes that can help to reveal their mechanism of action.
Tony Scott PhD ’23 is the lead author of the paper, which appears today in the Journal of the American Chemical Society.
Fusing rings
Oligocyclotryptamines belong to a class of molecules called alkaloids — nitrogen-containing organic compounds produced mainly by plants. At least eight different oligocyclotryptamines have been isolated from a genus of flowering plants known as Psychotria, most of which are found in tropical forests.
Since the 1950s, scientists have studied the structure and synthesis of dimeric cyclotryptamines, which have two cyclotryptamine subunits. Over the past 20 years, significant progress has been made characterizing and synthesizing dimers and other smaller members of the family. However, no one has been able to synthesize the largest oligocyclotryptamines, which have six or seven rings fused together.
One of the hurdles in synthesizing these molecules is a step that requires formation of a bond between a carbon atom of one tryptamine-derived subunit to a carbon atom of the next subunit. The oligocyclotryptamines have two types of these linkages, both containing at least one carbon atom that has bonds with four other carbons. That extra bulk makes those carbon atoms less accessible to undergo reactions, and controlling the stereochemistry — the orientation of the atoms around the carbon — at all these junctures poses a significant challenge.
For many years, Movassaghi’s lab has been developing ways to form carbon-carbon bonds between carbon atoms that are already crowded with other atoms. In 2011, they devised a method that involves transforming the two carbon atoms into carbon radicals (carbon atoms with one unpaired electron) and directing their union. To create these radicals, and guide the paired union to be completely selective, the researchers first attach each of the targeted carbon atoms to a nitrogen atom; these two nitrogen atoms bind to each other.
When the researchers shine certain wavelengths of light on the substrate containing the two fragments linked via the two nitrogen atoms, it causes the two atoms of nitrogen to break away as nitrogen gas, leaving behind two very reactive carbon radicals in close proximity that join together almost immediately. This type of bond formation has also allowed the researchers to control the molecules’ stereochemistry.
Movassaghi demonstrated this approach, which he calls diazene-directed assembly, by synthesizing other types of alkaloids, including the communesins. These compounds are found in fungi and consist of two ring-containing molecules, or monomers, joined together. Later, Movassaghi began using this approach to fuse larger numbers of monomers, and he and Scott eventually turned their attention to the largest oligocyclotryptamine alkaloids.
The synthesis that they developed begins with one molecule of cyclotryptamine derivative, to which additional cyclotryptamine fragments with correct relative stereochemistry and position selectivity are added, one at a time. Each of these additions is made possible by the diazene-directed process that Movassaghi’s lab previously developed.
“The reason why we’re excited about this is that this single solution allowed us to go after multiple targets,” Movassaghi says. “That same route provides us a solution to multiple members of the natural product family because by extending the iteration one more cycle, your solution is now applied to a new natural product.”
“A tour de force”
Using this approach, the researchers were able to create molecules with six or seven cyclotryptamine rings, which has never been done before.
“Researchers worldwide have been trying to find a way to make these molecules, and Movassaghi and Scott are the first to pull it off,” says Seth Herzon, a professor of chemistry at Yale University, who was not involved in the research. Herzon described the work as “a tour de force in organic synthesis.”
Now that the researchers have synthesized these naturally occurring oligocyclotryptamines, they should be able to generate enough of the compounds that their potential therapeutic activity can be more thoroughly investigated.
They should also be able to create novel compounds by switching in slightly different cyclotryptamine subunits, Movassaghi says.
“We will continue to use this very precise way of adding these cyclotryptamine units to assemble them together into complex systems that have not been addressed yet, including derivatives that could potentially have improved properties,” he says.
The research was funded by the U.S. National Institute of General Medical Sciences.
Alex Shalek named director of the Institute for Medical Engineering and ScienceProfessor who uses a cross-disciplinary approach to understand human diseases on a molecular and cellular level succeeds Elazer Edelman.Alex K. Shalek, the J. W. Kieckhefer Professor in the MIT Institute for Medical Engineering and Sciences (IMES) and Department of Chemistry, has been named the new director of IMES, effective Aug. 1.
“Professor Shalek’s substantial contributions to the scientific community as a researcher and educator have been exemplary. His extensive network across MIT, Harvard, and Mass General Brigham will be a tremendous asset as director of IMES,” says Anantha Chandrakasan, chief innovation and strategy officer, dean of the School of Engineering, and the Vannevar Bush Professor of Electrical Engineering and Computer Science. “He will undoubtedly be an excellent leader, bringing his innovative approach and collaborative spirit to this new role.”
Shalek is a core member of IMES, a professor of chemistry, and holds several leadership positions, including director of the Health Innovation Hub. He is also an extramural member of MIT’s Koch Institute for Integrative Cancer Research; a member of the Ragon Institute of Mass General, MIT, and Harvard; an institute member of the Broad Institute of MIT and Harvard; an assistant in immunology at Mass General Brigham; and an instructor in health sciences and technology at Harvard Medical School.
The Shalek Lab’s research seeks to uncover how communities of cells work together within human tissues to support health, and how they become dysregulated in disease. By developing and applying innovative experimental and computational technologies, they are shedding light on a wide range of human health conditions.
Shalek and his team use a cross-disciplinary approach that combines genomics, chemical biology, and nanotechnology to develop platforms to profile and control cells and their interactions. Collaborating with researchers across the globe, they apply these tools to study human diseases in great detail. Their goal is to connect what occurs at a cellular level with what medical professionals observe in patients, paving the way for more precise ways to prevent and treat diseases.
Over the course of his career, Shalek’s groundbreaking research has earned him widespread recognition and numerous awards and honors. These include an NIH New Innovator Award, a Beckman Young Investigator Award, a Searle Scholar Award, a Pew-Stewart Scholar Award, an Alfred P. Sloan Research Fellowship in Chemistry, and an Avant-Garde (DP1 Pioneer) Award. Shalek has also been celebrated for his dedication as a faculty member, educator, and mentor. He was awarded the 2019-20 Harold E. Edgerton Faculty Achievement Award at MIT and the 2020 HMS Young Mentor Award.
Shalek received his bachelor’s degree in chemical physics from Columbia University and his master’s and PhD in chemical physics from Harvard University. Prior to joining MIT’s faculty in 2014, he was a postdoc at the Broad Institute.
Shalek succeeds Elazer Edelman, the Edward J. Poitras Professor in Medical Engineering and Science, who has led IMES since April 2018.
“I am grateful to Professor Edelman for his incredible leadership and service to IMES over the past six years,” says Chandrakasan. “His contributions to IMES have been invaluable, and we are thankful for his dedication and vision during his tenure as director.”
3 Questions: Preparing students in MIT’s Naval ROTC program“MIT graduates are top performers in the fleet, and the rigorous four-year program they complete prepares them to be ready to respond to future technical and leadership challenges,” says Commander Jennifer Huck.Being able to say, “I fly helicopters” — specifically the Seahawk series that boast a maximum cruise elevation of 10,000 feet and 210 miles per hour — must be a great conversation starter. So must saying that you are helping to train a future generation of naval cadets at MIT, Harvard and Tufts universities, and other local schools.
U.S. Navy Commander Jennifer A. Huck, executive officer (XO) for the Naval Reserve Officers Training Corps (NROTC) consortium, can do both. Called the Old Ironsides Battalion, the unit comprises around 80 midshipmen across six universities and is housed on the MIT campus.
After 20 years of active duty, Huck has now returned home, in a sense. She herself was commissioned through the NROTC program at Boston University, where she earned a BS in biomedical engineering in 2003. Here, Huck explains her role and how the Naval ROTC program prepares students to commission as officers in the U.S. Navy and Marine Corps upon graduation.
Q: Tell us a bit about your own military and academic career. Why did you decide to pursue that path? What has surprised you along the way? And of course, what is it like to fly helicopters?
A: I have always been a person who seeks a sense of purpose, and I enjoy being part of a team. I also grew up being very involved in athletics and wanted to keep physical fitness as a big part of my life. After learning about various educational opportunities the Navy offers, I instantly gravitated towards the idea of joining because I felt that the job checked the blocks for so many things that are important to me. I joined Navy ROTC at Boston University in 1999 and I have had nothing but amazing experiences since then.
As a midshipman, I explored career paths in medicine and nuclear power. My summer training experience in 2002 onboard the aircraft carrier USS Harry S Truman sealed the deal for me wanting to be a naval aviator. The freedom of flight was exhilarating and the responsibility, leadership, and skill required of the pilots fueled my drive for purpose and mission accomplishment — not to mention the views from above were quite nice!
So after graduating from BU, I completed naval flight training and earned my pilot wings in August 2005. I subsequently spent over 10 years flying missions operating in the Middle East, Horn of Africa, and Western Pacific. Flying multi-million dollar combat helicopters is thrilling and fulfilling as it requires precise control, coordination, and focus to agilely maneuver amidst immersive aircraft vibrations, loud rotor-blade noise, and anything else that may be in the area (weather, threats, terrain, etc).
Throughout my career, I’ve had many exciting assignments, including flying those H-60 combat helicopters, working operations at the U.S. Embassy in Colombia, developing requirements for next-generation technologies at the Pentagon, and instructing students in flight school and in ROTC.
It has, however, been the people, and not necessarily the jobs, that have kept me in the Navy for 21 years. There is no other organization where you will find the same camaraderie as military service.
Q: MIT has a long history of national service and takes great pride in its ROTC students — especially given the dual rigor of the curriculum and the military training. Can you explain what an XO does day to day and how you support students?
A: The NROTC executive officer plays a vital role in the leadership and administration of the program. As second-in-command, I assist the NROTC commander, Captain Jack Houdeshell, in managing the unit’s operations. I directly supervise the unit staff and midshipmen and provide guidance, mentorship, and support to ensure everyone fulfills their roles and responsibilities effectively.
Since our unit’s mission is to train midshipmen, I also oversee the development and execution of our training curriculum, which includes naval science classes, physical training, laboratory sessions, drill instruction, and other professional development activities. This oversight ensures that midshipmen are prepared to commission as officers in the United States Navy and Marine Corps upon graduation.
MIT graduates are top performers in the fleet, and the rigorous four-year program they complete here prepares them to be ready to respond to future technical and leadership challenges.
Q: As part of your service, you’ve traveled around the world, living and working in a half-dozen countries. How would you characterize the culture at MIT? What’s been special about your time on campus?
A: Like I previously mentioned, one of the most exciting parts about my job is the dynamic environment I operate in. Part of the dynamics involves traveling around the world and experiencing different cultures and conditions. My experience at MIT, in many ways, parallels certain cultural experiences from around the world.
First, MIT has a diverse student body with students representing numerous ethnic backgrounds, countries, and experiences. MIT students are very talented, hard-working, and focused on achieving their goals; they want to make the world a better place. MIT encourages freedom of thought and unique problem-solving, similar to what is required of our military and global leaders.
What I find most special about MIT is the people. Similar to the Navy, MIT creates a global network of friendships and lifelong connections. I consider the MIT community to be my “MIT family.”
The MIT School of Science is launching a center to advance knowledge and computational capabilities in the field of sustainability science, and support decision-makers in government, industry, and civil society to achieve sustainable development goals. Aligned with the Climate Project at MIT, researchers at the MIT Center for Sustainability Science and Strategy will develop and apply expertise from across the Institute to improve understanding of sustainability challenges, and thereby provide actionable knowledge and insight to inform strategies for improving human well-being for current and future generations.
Noelle Selin, professor at MIT’s Institute for Data, Systems and Society and the Department of Earth, Atmospheric and Planetary Sciences, will serve as the center’s inaugural faculty director. C. Adam Schlosser and Sergey Paltsev, senior research scientists at MIT, will serve as deputy directors, with Anne Slinn as executive director.
Incorporating and succeeding both the Center for Global Change Science and Joint Program on the Science and Policy of Global Change while adding new capabilities, the center aims to produce leading-edge research to help guide societal transitions toward a more sustainable future. Drawing on the long history of MIT’s efforts to address global change and its integrated environmental and human dimensions, the center is well-positioned to lead burgeoning global efforts to advance the field of sustainability science, which seeks to understand nature-society systems in their full complexity. This understanding is designed to be relevant and actionable for decision-makers in government, industry, and civil society in their efforts to develop viable pathways to improve quality of life for multiple stakeholders.
“As critical challenges such as climate, health, energy, and food security increasingly affect people’s lives around the world, decision-makers need a better understanding of the earth in its full complexity — and that includes people, technologies, and institutions as well as environmental processes,” says Selin. “Better knowledge of these systems and how they interact can lead to more effective strategies that avoid unintended consequences and ensure an improved quality of life for all.”
Advancing knowledge, computational capability, and decision support
To produce more precise and comprehensive knowledge of sustainability challenges and guide decision-makers to formulate more effective strategies, the center has set the following goals:
“The center’s work will advance fundamental understanding in sustainability science, leverage leading-edge computing and data, and promote engagement and impact,” says Selin. “Our researchers will help lead scientists and strategists across the globe who share MIT’s commitment to mobilizing knowledge to inform action toward a more sustainable world.”
Building a better world at MIT
Building on existing MIT capabilities in sustainability science and strategy, the center aims to:
“The Center for Sustainability Science and Strategy will provide the necessary synergy for our MIT researchers to develop, deploy, and scale up serious solutions to climate change and other critical sustainability challenges,” says Nergis Mavalvala, the Curtis and Kathleen Marble Professor of Astrophysics and dean of the MIT School of Science. “With Professor Selin at its helm, the center will also ensure that these solutions are created in concert with the people who are directly affected now and in the future.”
The center builds on more than three decades of achievements by the Center for Global Change Science and the Joint Program on the Science and Policy of Global Change, both of which were directed or co-directed by professor of atmospheric science Ronald Prinn.
Empowering the next generation of scientists in AfricaThe Future African Scientist organization was sparked by a connection between two students from different walks of life during an MIT program in South Africa.No one is born a world-class scientist. Instead, their skills are built over many years of education, networking, mentorship, and work in laboratories or in the field.
That’s the fundamental insight behind the not-for-profit organization Future African Scientist, which is seeking to unleash the scientific potential of the continent by providing African students and early-career scientists with the support they need to do world-renowned research that addresses problems in their local communities and beyond.
Future African Scientist, or FAS, partners with leading scientists and institutions around the world, including MIT, to offer educational courses, training, networking events, and other programming around scientific research and entrepreneurship. More importantly, graduates of FAS programs join a network of scientists that helps them match with jobs, internships, and further learning opportunities.
“Our programs aim to democratize access to science education and create a new wave of scientists that are going to study African problems and not just publish papers, but also translate that research into beneficial products as well as policies,” says FAS co-founder Martin Lubowa.
At the core of FAS is a belief in the power of connections to further scientific understanding. Perhaps it’s no surprise, then, that FAS began with a connection between two people from very different walks of life during an MIT program.
From roommates to co-founders
In 2020, Daniel Zhang ’22 participated in Biology Professor Bruce Walker’s course HST. 434 (Evolution of an Epidemic) as part of a MISTI Global Classroom during MIT’s Independent Activities Period (IAP). The course immerses students in a South African community to teach them about the AIDS epidemic from the perspective of doctors, researchers, policymakers, and local infected women.
That IAP happened to be the first year the class paired MIT students with students from the African Leadership Academy, which seeks to build leadership skills in African youth. Zhang’s roommate was Martin Lubowa.
“Martin and I bonded instantly despite coming from completely different cultures and backgrounds,” Zhang recalls. “We shared passions for education, mentorship, and sports.”
Despite waking up early each day for class, Zhang and Lubowa talked late into the nights. Many of their conversations centered around the differences in STEM opportunities between students in the U.S. and African countries. They also discussed the importance of STEM in economic development and eventually identified a lack of mentorship programs as a key problem. They decided to found Future African Scientist to close those gaps.
With support and encouragement from Walker, the pair kept in touch after the class and focused their mission to equipping university and high school students in Africa with early-stage mentorship and critical thinking skills that would enable them to conduct independent research projects.
In January 2022, they organized their first virtual bootcamp for students across Africa. The bootcamp featured virtual courses, lectures by leading African scientists, mentorship opportunities, and a capstone project that challenged students to apply their learnings.
“We didn’t want to just give them research skills, but also entrepreneurship skills and interpersonal skills to position them as scientific entrepreneurs,” Lubowa says.
After receiving positive feedback and learning more about the skills students needed, the founders broadened the structure of FAS.
Today, a similar bootcamp on foundational research skills serves as the first stage of FAS’s four-part Africa Science Research Academy. The second stage is a data-driven research project that exposes participants to working in a lab. The third stage teaches skills including entrepreneurship, leadership, financial literacy, and grant management. The final stage, the Africa Science Opportunity Network, is available to FAS graduates for life and is designed to connect participants with internships, jobs opportunities, and other research projects.
“What makes us different from most of the research training programs in Africa is that we are open to anyone who is curious,” Lubowa says. “Most of the programs on the continent target MDs who already practicing, or PhDs, which is a bit unfair for people who are curious, but they don’t have the right platform to channel that curiosity into meaningful experiences.”
To date, more than 100 students and young professionals have gone through FAS programming. The students hail from more than 30 universities and 15 countries. FAS has also partnered with 10 medical student associations that have helped it expand its network to more than 100,000 students across the continent. FAS is also in conversations with organizations like the African Microscope Initiative, which has offered to recruit FAS graduates for more specialized training in bioimaging, as well as African state governments to create upskilling programs that could serve as alternatives to MD and PhD programs.
“We see Africa transitioning from just being a beneficiary of the global scientific community to becoming a contributor,” Lubowa says. “That means we can help the U.S. and other Western countries solve their problems. The issue at the moment is getting people the skills they need and changing their mindset so they understand they can do great things, and that in the long run, they can not just generate knowledge, but also create enterprises that address some of these challenges within Africa and beyond.”
Meeting the needs of the continent
In 2022, a pair of students from the Association of Mbarara University Pharmaceutical Sciences in Uganda learned about the foundations of entrepreneurship through FAS’ programming. They are in the process of commercializing their research into mosquito repellants made from locally-sourced materials. That same year, an undergraduate Cameroonian alumna of FAS placed third in a national science competition despite going up against PhDs. His research was in early detection of pancreatic cancer.
“One of the aspirational goals of Future African Scientists is to cultivate a sustainable scientific ecosystem where beyond academia, there’s also a science industry in Africa,” Lubowa says.
Further down the line, FAS would like to open its own laboratories to broaden access to equipment, and FAS’s team has already spoken with companies that exchange second-hand medical and laboratory equipment to help improve scientific infrastructure at African institutes.
“Our long-term plans include establishing general-purpose, open laboratories where students across Africa can go and learn how to do practical science,” Lubowa says.
With all work, FAS seeks to empower Africans to become a global scientific force for good.
“We have a population of 1.2 billion people in Africa, but we only have 198 scientists per million people. The U.S. has more than 4,000 scientists per million people,” Lubowa says. “Africans also have the highest burden of disease, so there’s really a need for us to rethink how we have been training scientists, and it all goes back to these support systems. I really think we can change the scientific landscape in Africa.”
Scientists pin down the origins of the moon’s tenuous atmosphereThe barely-there lunar atmosphere is likely the product of meteorite impacts over billions of years, a new study finds.While the moon lacks any breathable air, it does host a barely-there atmosphere. Since the 1980s, astronomers have observed a very thin layer of atoms bouncing over the moon’s surface. This delicate atmosphere — technically known as an “exosphere” — is likely a product of some kind of space weathering. But exactly what those processes might be has been difficult to pin down with any certainty.
Now, scientists at MIT and the University of Chicago say they have identified the main process that formed the moon’s atmosphere and continues to sustain it today. In a study appearing today in Science Advances, the team reports that the lunar atmosphere is primarily a product of “impact vaporization.”
In their study, the researchers analyzed samples of lunar soil collected by astronauts during NASA’s Apollo missions. Their analysis suggests that over the moon’s 4.5-billion-year history its surface has been continuously bombarded, first by massive meteorites, then more recently, by smaller, dust-sized “micrometeoroids.” These constant impacts have kicked up the lunar soil, vaporizing certain atoms on contact and lofting the particles into the air. Some atoms are ejected into space, while others remain suspended over the moon, forming a tenuous atmosphere that is constantly replenished as meteorites continue to pelt the surface.
The researchers found that impact vaporization is the main process by which the moon has generated and sustained its extremely thin atmosphere over billions of years.
“We give a definitive answer that meteorite impact vaporization is the dominant process that creates the lunar atmosphere,” says the study’s lead author, Nicole Nie, an assistant professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “The moon is close to 4.5 billion years old, and through that time the surface has been continuously bombarded by meteorites. We show that eventually, a thin atmosphere reaches a steady state because it’s being continuously replenished by small impacts all over the moon.”
Nie’s co-authors are Nicolas Dauphas, Zhe Zhang, and Timo Hopp at the University of Chicago, and Menelaos Sarantos at NASA Goddard Space Flight Center.
Weathering’s roles
In 2013, NASA sent an orbiter around the moon to do some detailed atmospheric reconnaissance. The Lunar Atmosphere and Dust Environment Explorer (LADEE, pronounced “laddie”) was tasked with remotely gathering information about the moon’s thin atmosphere, surface conditions, and any environmental influences on the lunar dust.
LADEE’s mission was designed to determine the origins of the moon’s atmosphere. Scientists hoped that the probe’s remote measurements of soil and atmospheric composition might correlate with certain space weathering processes that could then explain how the moon’s atmosphere came to be.
Researchers suspect that two space weathering processes play a role in shaping the lunar atmosphere: impact vaporization and “ion sputtering” — a phenomenon involving solar wind, which carries energetic charged particles from the sun through space. When these particles hit the moon’s surface, they can transfer their energy to the atoms in the soil and send those atoms sputtering and flying into the air.
“Based on LADEE’s data, it seemed both processes are playing a role,” Nie says. “For instance, it showed that during meteorite showers, you see more atoms in the atmosphere, meaning impacts have an effect. But it also showed that when the moon is shielded from the sun, such as during an eclipse, there are also changes in the atmosphere’s atoms, meaning the sun also has an impact. So, the results were not clear or quantitative.”
Answers in the soil
To more precisely pin down the lunar atmosphere’s origins, Nie looked to samples of lunar soil collected by astronauts throughout NASA’s Apollo missions. She and her colleagues at the University of Chicago acquired 10 samples of lunar soil, each measuring about 100 milligrams — a tiny amount that she estimates would fit into a single raindrop.
Nie sought to first isolate two elements from each sample: potassium and rubidium. Both elements are “volatile,” meaning that they are easily vaporized by impacts and ion sputtering. Each element exists in the form of several isotopes. An isotope is a variation of the same element, that consists of the same number of protons but a slightly different number of neutrons. For instance, potassium can exist as one of three isotopes, each one having one more neutron, and there being slightly heavier than the last. Similarly, there are two isotopes of rubidium.
The team reasoned that if the moon’s atmosphere consists of atoms that have been vaporized and suspended in the air, lighter isotopes of those atoms should be more easily lofted, while heavier isotopes would be more likely to settle back in the soil. Furthermore, scientists predict that impact vaporization, and ion sputtering, should result in very different isotopic proportions in the soil. The specific ratio of light to heavy isotopes that remain in the soil, for both potassium and rubidium, should then reveal the main process contributing to the lunar atmosphere’s origins.
With all that in mind, Nie analyzed the Apollo samples by first crushing the soils into a fine powder, then dissolving the powders in acids to purify and isolate solutions containing potassium and rubidium. She then passed these solutions through a mass spectrometer to measure the various isotopes of both potassium and rubidium in each sample.
In the end, the team found that the soils contained mostly heavy isotopes of both potassium and rubidium. The researchers were able to quantify the ratio of heavy to light isotopes of both potassium and rubidium, and by comparing both elements, they found that impact vaporization was most likely the dominant process by which atoms are vaporized and lofted to form the moon’s atmosphere.
“With impact vaporization, most of the atoms would stay in the lunar atmosphere, whereas with ion sputtering, a lot of atoms would be ejected into space,” Nie says. “From our study, we now can quantify the role of both processes, to say that the relative contribution of impact vaporization versus ion sputtering is about 70:30 or larger.” In other words, 70 percent or more of the moon’s atmosphere is a product of meteorite impacts, whereas the remaining 30 percent is a consequence of the solar wind.
“The discovery of such a subtle effect is remarkable, thanks to the innovative idea of combining potassium and rubidium isotope measurements along with careful, quantitative modeling,” says Justin Hu, a postdoc who studies lunar soils at Cambridge University, who was not involved in the study. “This discovery goes beyond understanding the moon’s history, as such processes could occur and might be more significant on other moons and asteroids, which are the focus of many planned return missions.”
“Without these Apollo samples, we would not be able to get precise data and measure quantitatively to understand things in more detail,” Nie says. “It’s important for us to bring samples back from the moon and other planetary bodies, so we can draw clearer pictures of the solar system’s formation and evolution.”
This work was supported, in part, by NASA and the National Science Foundation.
Scientists find a human “fingerprint” in the upper troposphere’s increasing ozoneKnowing where to look for this signal will help researchers identify specific sources of the potent greenhouse gas.Ozone can be an agent of good or harm, depending on where you find it in the atmosphere. Way up in the stratosphere, the colorless gas shields the Earth from the sun’s harsh ultraviolet rays. But closer to the ground, ozone is a harmful air pollutant that can trigger chronic health problems including chest pain, difficulty breathing, and impaired lung function.
And somewhere in between, in the upper troposphere — the layer of the atmosphere just below the stratosphere, where most aircraft cruise — ozone contributes to warming the planet as a potent greenhouse gas.
There are signs that ozone is continuing to rise in the upper troposphere despite efforts to reduce its sources at the surface in many nations. Now, MIT scientists confirm that much of ozone’s increase in the upper troposphere is likely due to humans.
In a paper appearing today in the journal Environmental Science and Technology, the team reports that they detected a clear signal of human influence on upper tropospheric ozone trends in a 17-year satellite record starting in 2005.
“We confirm that there’s a clear and increasing trend in upper tropospheric ozone in the northern midlatitudes due to human beings rather than climate noise,” says study lead author Xinyuan Yu, a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS).
“Now we can do more detective work and try to understand what specific human activities are leading to this ozone trend,” adds co-author Arlene Fiore, the Peter H. Stone and Paola Malanotte Stone Professor in Earth, Atmospheric and Planetary Sciences.
The study’s MIT authors include Sebastian Eastham and Qindan Zhu, along with Benjamin Santer at the University of California at Los Angeles, Gustavo Correa of Columbia University, Jean-François Lamarque at the National Center for Atmospheric Research, and Jerald Zimeke at NASA Goddard Space Flight Center.
Ozone’s tangled web
Understanding ozone’s causes and influences is a challenging exercise. Ozone is not emitted directly, but instead is a product of “precursors” — starting ingredients, such as nitrogen oxides and volatile organic compounds (VOCs), that react in the presence of sunlight to form ozone. These precursors are generated from vehicle exhaust, power plants, chemical solvents, industrial processes, aircraft emissions, and other human-induced activities.
Whether and how long ozone lingers in the atmosphere depends on a tangle of variables, including the type and extent of human activities in a given area, as well as natural climate variability. For instance, a strong El Niño year could nudge the atmosphere’s circulation in a way that affects ozone’s concentrations, regardless of how much ozone humans are contributing to the atmosphere that year.
Disentangling the human- versus climate-driven causes of ozone trend, particularly in the upper troposphere, is especially tricky. Complicating matters is the fact that in the lower troposphere — the lowest layer of the atmosphere, closest to ground level — ozone has stopped rising, and has even fallen in some regions at northern midlatitudes in the last few decades. This decrease in lower tropospheric ozone is mainly a result of efforts in North America and Europe to reduce industrial sources of air pollution.
“Near the surface, ozone has been observed to decrease in some regions, and its variations are more closely linked to human emissions,” Yu notes. “In the upper troposphere, the ozone trends are less well-monitored but seem to decouple with those near the surface, and ozone is more easily influenced by climate variability. So, we don’t know whether and how much of that increase in observed ozone in the upper troposphere is attributed to humans.”
A human signal amid climate noise
Yu and Fiore wondered whether a human “fingerprint” in ozone levels, caused directly by human activities, could be strong enough to be detectable in satellite observations in the upper troposphere. To see such a signal, the researchers would first have to know what to look for.
For this, they looked to simulations of the Earth’s climate and atmospheric chemistry. Following approaches developed in climate science, they reasoned that if they could simulate a number of possible climate variations in recent decades, all with identical human-derived sources of ozone precursor emissions, but each starting with a slightly different climate condition, then any differences among these scenarios should be due to climate noise. By inference, any common signal that emerged when averaging over the simulated scenarios should be due to human-driven causes. Such a signal, then, would be a “fingerprint” revealing human-caused ozone, which the team could look for in actual satellite observations.
With this strategy in mind, the team ran simulations using a state-of-the-art chemistry climate model. They ran multiple climate scenarios, each starting from the year 1950 and running through 2014.
From their simulations, the team saw a clear and common signal across scenarios, which they identified as a human fingerprint. They then looked to tropospheric ozone products derived from multiple instruments aboard NASA’s Aura satellite.
“Quite honestly, I thought the satellite data were just going to be too noisy,” Fiore admits. “I didn’t expect that the pattern would be robust enough.”
But the satellite observations they used gave them a good enough shot. The team looked through the upper tropospheric ozone data derived from the satellite products, from the years 2005 to 2021, and found that, indeed, they could see the signal of human-caused ozone that their simulations predicted. The signal is especially pronounced over Asia, where industrial activity has risen significantly in recent decades and where abundant sunlight and frequent weather events loft pollution, including ozone and its precursors, to the upper troposphere.
Yu and Fiore are now looking to identify the specific human activities that are leading to ozone’s increase in the upper troposphere.
“Where is this increasing trend coming from? Is it the near-surface emissions from combusting fossil fuels in vehicle engines and power plants? Is it the aircraft that are flying in the upper troposphere? Is it the influence of wildland fires? Or some combination of all of the above?” Fiore says. “Being able to separate human-caused impacts from natural climate variations can help to inform strategies to address climate change and air pollution.”
This research was funded, in part, by NASA.
A bright and airy hub for climate at MITTogether, the new Moghadam Building and refurbished Green Building form a vibrant new center to tackle pressing global concerns of sustainability and climate change.Seen from a distance, MIT’s Cecil and Ida Green Building (Building 54) — designed by renowned architect and MIT alumnus I.M. Pei ’40 — is one of the most iconic buildings on the Cambridge, Massachusetts, skyline. Home to the MIT Department of Earth, Atmospheric and Planetary Sciences (EAPS), the 21-story concrete structure soars over campus, topped with its distinctive spherical radar dome. Close up, however, it was a different story.
A sunless, two-story, open-air plaza beneath the tower previously served as a nondescript gateway to the department’s offices, labs, and classrooms above. “It was cold and windy — probably the windiest place on campus,” EAPS department head Robert van der Hilst, the Schlumberger Professor of Earth and Planetary Sciences, told a packed auditorium inside the building in March. “You would pass through the elevators and disappear into the corridors, never to be seen again until the end of the day.”
Van der Hilst was speaking at a dedication event to celebrate the opening of the renovated and expanded space, 60 years after the Green Building’s original dedication in 1964. In a dramatic transformation, the perpetually-shaded expanse beneath the tower has been filled with an airy, glassed-in structure that is as inviting as the previous space was forbidding.
Designed to meet LEED-platinum certification, the newly-constructed Tina and Hamid Moghadam Building (Building 55) seems to float next to the Brutalist tower, its glass façade both opening up the interior and reflecting the sunlight and green space outside. The 300-seat auditorium within the original tower has been similarly transformed, bringing light and space to the newly dubbed Dixie Lee Bryant (1891) Lecture Hall, named after the first person to earn a geology degree at MIT.
Catalyzing collaboration
The project is about more than updating an overlooked space. “The building we’re here to celebrate today does something else,” MIT President Sally Kornbluth said at the dedication.
“In its lightness, in its transparency, it calls attention not to itself, but to the people gathered inside it. In its warmth, its openness, it makes room for culture and community. And it welcomes in those who don’t yet belong … as we take on the immense challenges of climate together,” she continued, referencing the recent launch of The Climate Project at MIT — a whole-of-MIT initiative to innovate bold solutions to climate change. In MIT’s famously decentralized structure, the Moghadam Building provides a new physical hub for students, scientists, and engineers interested in climate and the environment to congregate and share ideas.
From the start, fostering this kind of multidisciplinary collaboration was part of Van der Hilst’s vision. In addition to serving as the flagship location for EAPS, Building 54 has long been the administrative home of the MIT-WHOI Joint Program in Oceanography/Applied Ocean Science and Engineering — a graduate program in partnership with Woods Hole Oceanographic Institute. With the addition of Building 55, EAPS has now been joined by the MIT Environmental Solutions Initiative (ESI) — a campus-wide program fostering education, outreach, and innovation in earth system science, urban infrastructure, and sustainability — and will welcome closer collaboration with Terrascope — a first-year learning community which invites its students to take on real-world environmental challenges.
A shared vision comes to life
The building project dovetailed with the long-overdue refurbishment of the Green Building. After a multi-year fundraising campaign where Van der Hilst spearheaded the department’s efforts, the project received a major boost from lead donors Tina and Hamid Moghadam ’77, SM ’78, allowing the department to break ground in November 2021.
In Moghadam, chair and CEO of Prologis, which owns 1.2 billion square feet of warehouses and other logistics infrastructure worldwide, EAPS found a fellow champion for climate and environmental innovation. By putting solar panels on the roofs of Prologis buildings, the company is now the second largest on-site producer of solar energy in the United States. “I don’t think there needs to be a trade-off between good sound economics and return on investment and solving climate change problems,” Moghadam said at the dedication. “The solutions that really work are the ones that actually make sense in a market economy.”
Architectural firm AW-ARCH designed the Moghadam Building with a light touch, emphasizing spaciousness in contrast to the heavy concrete buildings that surround it. “The kind of delicacy and fragility of the thing is in some ways a depiction of what happens here,” said architect and co-founding partner Alex Anmahian at the dedication reception, giving a nod to the study of the delicate balance of the earth system itself. The sense is further illustrated by the responsiveness of the façade to the surrounding environment, which, depending on the time of day and quality of light, makes the glass alternately reflective and transparent.
Inside, the 11,900-square foot pavilion is highly flexible and serves as a showcase for the science that happens in the labs and offices above. Central to the space is a 16-foot by 9-foot video wall featuring vivid footage of field work, lab research, data visualizations, and natural phenomena — visible even to passers-by outside. The video wall is counterposed to an unpretentious set of stair-step bleachers leading to the second floor that could play host to anything from a scientific lecture to a community pizza-and-movie night.
Van der Hilst has referred to his vision for the atrium as a “campus living room,” and the furniture throughout is intentionally chosen to allow for impromptu rearrangements, providing a valuable public space on campus for students to work and socialize.
The second level is similarly adaptable, featuring three classrooms with state-of-the-art teaching technologies that can be transformed from a single large space for a hackathon to intimate rooms for discussion.
“The space is really meant for a yet unforeseen experience,” Anmahian says. “The reason it is so open is to allow for any possibility.”
The inviting, dynamic design of the pavilion has also become an instant point of pride for the building’s inhabitants. At the dedication, School of Science dean Nergis Mavalvala quipped that anyone walking into the space “gains two inches in height.”
Van der Hilst quoted a colleague with a similar observation: “Now, when I come into this space, I feel respected by it.”
The perfect complement
Another significant feature of the project is the List Visual Arts Center Percent-for-Art Program installation by conceptual artist Julian Charrière, entitled “Everything Was Forever Until It Was No More.”
Consisting of three interrelated works, the commission includes: “Not All Who Wander Are Lost,” three glacial erratic boulders which sit atop their own core samples in the surrounding green space; “We Are All Astronauts,” a trio of glass pillars containing vintage globes with distinctions between nations, land, and sea removed; and “Pure Waste,” a synthetic diamond embedded in the foundation, created from carbon captured from the air and the breath of researchers who work in the building.
Known for themes that explore the transformation of the natural world over time and humanity’s complex relationship with our environment, Charrière was a perfect fit to complement the new Building 55 — offering a thought-provoking perspective on our current environmental challenges while underscoring the value of the research that happens within its walls.
Physicists report new insights into exotic particles key to magnetismThe work on excitons, originating from ultrathin materials, could impact future electronics and establishes a new way to study these particles through a powerful instrument at the Brookhaven National Laboratory.MIT physicists and colleagues report new insights into exotic particles key to a form of magnetism that has attracted growing interest because it originates from ultrathin materials only a few atomic layers thick. The work, which could impact future electronics and more, also establishes a new way to study these particles through a powerful instrument at the National Synchrotron Light Source II at Brookhaven National Laboratory.
Among their discoveries, the team has identified the microscopic origin of these particles, known as excitons. They showed how they can be controlled by chemically “tuning” the material, which is primarily composed of nickel. Further, they found that the excitons propagate throughout the bulk material instead of being bound to the nickel atoms.
Finally, they proved that the mechanism behind these discoveries is ubiquitous to similar nickel-based materials, opening the door for identifying — and controlling — new materials with special electronic and magnetic properties.
The open-access results are reported in the July 12 issue of Physical Review X.
“We’ve essentially developed a new research direction into the study of these magnetic two-dimensional materials that very much relies on an advanced spectroscopic method, resonant inelastic X-ray scattering (RIXS), which is available at Brookhaven National Lab,” says Riccardo Comin, MIT’s Class of 1947 Career Development Associate Professor of Physics and leader of the work. Comin is also affiliated with the Materials Research Laboratory and the Research Laboratory of Electronics.
Comin’s colleagues on the work include Connor A. Occhialini, an MIT graduate student in physics, and Yi Tseng, a recent MIT postdoc now at Deutsches Elektronen-Synchrotron (DESY). The two are co-first authors of the Physical Review X paper.
Additional authors are Hebatalla Elnaggar of the Sorbonne; Qian Song, a graduate student in MIT’s Department of Physics; Mark Blei and Seth Ariel Tongay of Arizona State University; Frank M. F. de Groot of Utrecht University; and Valentina Bisogni and Jonathan Pelliciari of Brookhaven National Laboratory.
Ultrathin layers
The magnetic materials at the heart of the current work are known as nickel dihalides. They are composed of layers of nickel atoms sandwiched between layers of halogen atoms (halogens are one family of elements), which can be isolated to atomically thin layers. In this case, the physicists studied the electronic properties of three different materials composed of nickel and the halogens chlorine, bromine, or iodine. Despite their deceptively simple structure, these materials host a rich variety of magnetic phenomena.
The team was interested in how these materials’ magnetic properties respond when exposed to light. They were specifically interested in particular particles — the excitons — and how they are related to the underlying magnetism. How exactly do they form? Can they be controlled?
Enter excitons
A solid material is composed of different types of elementary particles, such as protons and electrons. Also ubiquitous in such materials are “quasiparticles” that the public is less familiar with. These include excitons, which are composed of an electron and a “hole,” or the space left behind when light is shone on a material and energy from a photon causes an electron to jump out of its usual position.
Through the mysteries of quantum mechanics, however, the electron and hole are still connected and can “communicate” with each other through electrostatic interactions. This interaction leads to a new composite particle formed by the electron and the hole — an exciton.
Excitons, unlike electrons, have no charge but possess spin. The spin can be thought of as an elementary magnet, in which the electrons are like little needles orienting in a certain way. In a common refrigerator magnet, the spins all point in the same direction. Generally speaking, the spins can organize in other patterns leading to different kinds of magnets. The unique magnetism associated with the nickel dihalides is one of these less-conventional forms, making it appealing for fundamental and applied research.
The MIT team explored how excitons form in the nickel dihalides. More specifically, they identified the exact energies, or wavelengths, of light necessary for creating them in the three materials they studied.
“We were able to measure and identify the energy necessary to form the excitons in three different nickel halides by chemically ‘tuning,’ or changing, the halide atom from chlorine to bromine to iodine,” says Occhialini. “This is one essential step towards understanding how photons — light — could one day be used to interact with or monitor the magnetic state of these materials.” Ultimate applications include quantum computing and novel sensors.
The work could also help predict new materials involving excitons that might have other interesting properties. Further, while the studied excitons originate on the nickel atoms, the team found that they do not remain localized to these atomic sites. Instead, “we showed that they can effectively hop between sites throughout the crystal,” Occhialini says. “This observation of hopping is the first for these types of excitons, and provides a window into understanding their interplay with the material’s magnetic properties.”
A special instrument
Key to this work — in particular for observing the exciton hopping — is resonant inelastic X-ray scattering (RIXS), an experimental technique that co-authors Pelliciari and Bisogni helped pioneer. Only a few facilities in the world have advanced high energy resolution RIXS instruments. One is at Brookhaven. Pelliciari and Bisogni are part of the team running the RIXS facility at Brookhaven. Occhialini will be joining the team there as a postdoc after receiving his MIT PhD.
RIXS, with its specific sensitivity to the excitons from the nickel atoms, allowed the team to “set the basis for a general framework for nickel dihalide systems,” says Pelliciari. “it allowed us to directly measure the propagation of excitons.”
This work was supported by the U.S. Department of Energy Basic Energy Science and Brookhaven National Laboratory through the Co-design Center for Quantum Advantage (C2QA), a DoE Quantum Information Science Research Center.
New method enables fast, accurate estimates of cardiovascular state to inform blood pressure managementA mathematical method, validated with experimental data, provides a fast, reliable, and minimally invasive way of determining how to treat critical blood pressure changes during surgery or intensive care.If patients receiving intensive care or undergoing major surgery develop excessively high or low blood pressures, they could suffer severe organ dysfunction. It’s not enough for their care team to know that pressure is abnormal. To choose the correct drug to treat the problem, doctors must know why blood pressure has changed. A new MIT study presents the mathematical framework needed to derive that crucial information accurately and in real time.
The mathematical approach, described in a recent open-access study in IEEE Transactions on Biomedical Engineering, produces proportional estimates of the two critical factors underlying blood pressure changes: the heart’s rate of blood output (cardiac output) and the arterial system’s resistance to that blood flow (systemic vascular resistance). By applying the new method to previously collected data from animal models, the researchers show that their estimates, derived from minimally invasive measures of peripheral arterial blood pressure, accurately matched estimates using additional information from an invasive flow probe placed on the aorta. Moreover, the estimates accurately tracked the changes induced in the animals by the various drugs physicians use to correct aberrant blood pressure.
“Estimates of resistance and cardiac output from our approach provide information that can readily be used to guide hemodynamic management decisions in real time,” the study authors wrote.
With further testing leading to regulatory approval, the authors say, the method would be applicable during heart surgeries, liver transplants, intensive care unit treatment, and many other procedures affecting cardiovascular function or blood volume.
“Any patient who is having cardiac surgery could need this,” says study senior author Emery N. Brown, the Edward Hood Taplin Professor of Medical Engineering and Computational Neuroscience in The Picower Institute for Learning and Memory, the Institute for Medical Engineering and Science, and the Department of Brain and Cognitive Sciences at MIT. Brown is also an anesthesiologist at Massachusetts General Hospital and a professor of anesthesiology at Harvard Medical School. “So might any patient undergoing a more normal surgery but who might have a compromised cardiovascular system, such as ischemic heart disease. You can’t have the blood pressure being all over the place.”
The study’s lead author is electrical engineering and computer science (EECS) graduate student Taylor Baum, who is co-supervised by Brown and Munther Dahleh, the William A. Coolidge Professor in EECS.
Algorithmic advance
The idea that cardiac output and systemic resistance are the two key components of blood pressure comes from the two-element Windkessel model. The new study is not the first to use the model to estimate these components from blood pressure measurements, but previous attempts ran into a trade-off between quick estimate updates and the accuracy of estimates; methods would either provide more erroneous estimates at every beat or more reliable estimates that are updated at minute time scales. Led by Baum, the MIT team overcame the trade-off with a new approach of applying statistical and signal processing techniques such as “state-space” modeling.
“Our estimates, updated at every beat, are not just informed by the current beat; but they incorporate where things were in previous beats as well,” Baum says. “It’s that combination of past history and current observations that produces a more reliable estimate while still at a beat-by-beat time scale.”
Notably, the resulting estimates of cardiac output and systemic resistance are “proportional,” meaning that they are each inextricably linked in the math with another co-factor, rather than estimated on their own. But application of the new method to data collected in an older study from six animals showed that the proportional estimates from recordings using minimally invasive catheters provide comparable information for cardiovascular system management.
One key finding was that the proportional estimates made based on arterial blood pressure readings from catheters inserted in various locations away from the heart (e.g., the leg or the arm) mirrored estimates derived from more invasive catheters placed within the aorta. The significance of the finding is that a system using the new estimation method could in some cases rely on a minimally invasive catheter in various peripheral arteries, thereby avoiding the need for a riskier placement of a central artery catheter or a pulmonary artery catheter directly in the heart, the clinical gold standard for cardiovascular state estimation.
Another key finding was that when the animals received each of five drugs that doctors use to regulate either systemic vascular resistance or cardiac output, the proportional estimates tracked the resulting changes properly. The finding therefore suggests that the proportional estimates of each factor are accurately reflecting their physiological changes.
Toward the clinic
With these encouraging results, Baum and Brown say, the current method can be readily implemented in clinical settings to inform perioperative care teams about underlying causes of critical blood pressure changes. They are actively pursuing regulatory approval of use of this method in a clinical device.
Additionally, the researchers are pursuing more animal studies to validate an advanced blood pressure management approach that uses this method. They have developed a closed-loop system, informed by this estimation framework, to precisely regulate blood pressure in an animal model. Upon completion of the animal studies, they will apply for regulatory clearance to test the system in humans.
In addition to Baum, Dahleh and Brown, the paper’s other authors are Elie Adam, Christian Guay, Gabriel Schamberg, Mohammadreza Kazemi, and Thomas Heldt.
The National Science Foundation, the National Institutes of Health, a Mathworks Fellowship, The Picower Institute for Learning and Memory, and The JPB Foundation supported the study.
New transistor’s superlative properties could have broad electronics applicationsUltrathin material whose properties “already meet or exceed industry standards” enables superfast switching, extreme durability.In 2021, a team led by MIT physicists reported creating a new ultrathin ferroelectric material, or one where positive and negative charges separate into different layers. At the time they noted the material’s potential for applications in computer memory and much more. Now the same core team and colleagues — including two from the lab next door — have built a transistor with that material and shown that its properties are so useful that it could change the world of electronics.
Although the team’s results are based on a single transistor in the lab, “in several aspects its properties already meet or exceed industry standards” for the ferroelectric transistors produced today, says Pablo Jarillo-Herrero, the Cecil and Ida Green Professor of Physics, who led the work with professor of physics Raymond Ashoori. Both are also affiliated with the Materials Research Laboratory.
“In my lab we primarily do fundamental physics. This is one of the first, and perhaps most dramatic, examples of how very basic science has led to something that could have a major impact on applications,” Jarillo-Herrero says.
Says Ashoori, “When I think of my whole career in physics, this is the work that I think 10 to 20 years from now could change the world.”
Among the new transistor’s superlative properties:
The work is reported in a recent issue of Science. The co-first authors of the paper are Kenji Yasuda, now an assistant professor at Cornell University, and Evan Zalys-Geller, now at Atom Computing. Additional authors are Xirui Wang, an MIT graduate student in physics; Daniel Bennett and Efthimios Kaxiras of Harvard University; Suraj S. Cheema, an assistant professor in MIT’s Department of Electrical Engineering and Computer Science and an affiliate of the Research Laboratory of Electronics; and Kenji Watanabe and Takashi Taniguchi of the National Institute for Materials Science in Japan.
What they did
In a ferroelectric material, positive and negative charges spontaneously head to different sides, or poles. Upon the application of an external electric field, those charges switch sides, reversing the polarization. Switching the polarization can be used to encode digital information, and that information will be nonvolatile, or stable over time. It won’t change unless an electric field is applied. For a ferroelectric to have broad application to electronics, all of this needs to happen at room temperature.
The new ferroelectric material reported in Science in 2021 is based on atomically thin sheets of boron nitride that are stacked parallel to each other, a configuration that doesn’t exist in nature. In bulk boron nitride, the individual layers of boron nitride are instead rotated by 180 degrees.
It turns out that when an electric field is applied to this parallel stacked configuration, one layer of the new boron nitride material slides over the other, slightly changing the positions of the boron and nitrogen atoms. For example, imagine that each of your hands is composed of only one layer of cells. The new phenomenon is akin to pressing your hands together then slightly shifting one above the other.
“So the miracle is that by sliding the two layers a few angstroms, you end up with radically different electronics,” says Ashoori. The diameter of an atom is about 1 angstrom.
Another miracle: “nothing wears out in the sliding,” Ashoori continues. That’s why the new transistor could be switched 100 billion times without degrading. Compare that to the memory in a flash drive made with conventional materials. “Each time you write and erase a flash memory, you get some degradation,” says Ashoori. “Over time, it wears out, which means that you have to use some very sophisticated methods for distributing where you’re reading and writing on the chip.” The new material could make those steps obsolete.
A collaborative effort
Yasuda, the co-first author of the current Science paper, applauds the collaborations involved in the work. Among them, “we [Jarillo-Herrero’s team] made the material and, together with Ray [Ashoori] and [co-first author] Evan [Zalys-Geller], we measured its characteristics in detail. That was very exciting.” Says Ashoori, “many of the techniques in my lab just naturally applied to work that was going on in the lab next door. It’s been a lot of fun.”
Ashoori notes that “there’s a lot of interesting physics behind this” that could be explored. For example, “if you think about the two layers sliding past each other, where does that sliding start?” In addition, says Yasuda, could the ferroelectricity be triggered with something other than electricity, like an optical pulse? And is there a fundamental limit to the amount of switches the material can make?
Challenges remain. For example, the current way of producing the new ferroelectrics is difficult and not conducive to mass manufacturing. “We made a single transistor as a demonstration. If people could grow these materials on the wafer scale, we could create many, many more,” says Yasuda. He notes that different groups are already working to that end.
Concludes Ashoori, “There are a few problems. But if you solve them, this material fits in so many ways into potential future electronics. It’s very exciting.”
This work was supported by the U.S. Army Research Office, the MIT/Microsystems Technology Laboratories Samsung Semiconductor Research Fund, the U.S. National Science Foundation, the Gordon and Betty Moore Foundation, the Ramon Areces Foundation, the Basic Energy Sciences program of the U.S. Department of Energy, the Japan Society for the Promotion of Science, and the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.
When learning at MIT means studying thousands of miles awayMISTI’s Global Classrooms helps students address global issues within their local context.This summer, a group of MIT students traveled to Sicily’s southeastern coast to learn about threats to local communities related to sea level rise. They visited ancient archeological sites that are in danger of being wiped out, and worked with local college students on preservation and adaptation techniques.
This past January, another group of MIT students travelled to South Africa to study the biology of HIV and learn about a local community’s public health challenges concerning the disease. Another group travelled to Spain and lived with local families in Madrid while studying Spanish literature, culture, and history.
Some lessons can’t be taught in the classroom. That’s the reasoning behind the MIT International Science and Technology Initiatives (MISTI) Global Classrooms program.
Led by MIT faculty members, some Global Classrooms focus on grand challenges such as climate, sustainability, and health, while others deal with language, culture, and society. But all Global Classrooms benefit from their location: MIT students gain a unique perspective on the topics they study by engaging with the local community.
“MISTI exists because we believe every graduate of MIT should be capable of connecting to and learning from colleagues all over the world,” MISTI Executive Director April Julich Perez says. “The types of problems MIT graduates will work on in their careers will require them to have an understanding of how people in different cultures might look at a problem and go about trying to solve it. This can’t be fully realized in a class on our Cambridge campus but requires an authentic global experience. We want to help our students widen their apertures to see new ways to design solutions within regional contexts. Global Classrooms help make that possible.”
Helping faculty teach
Global Classrooms arose organically from a campus need. For many years, MIT faculty have been taking students on trips around the world to learn from different communities. MISTI, with its expertise in designing global internships and other immersive learning experiences abroad, would often be tapped by faculty informally to provide their expertise.
About two years ago, MISTI decided to formalize this process by launching the MISTI Global Classrooms program. The program offers a variety of modalities to meet a range of needs across the Institute. For example, if a faculty member on campus is interested in taking students abroad, MISTI can provide advising and resources around handling travel logistics, safety, and learning in new places. On the other end of the spectrum, MISTI can serve as an implementation partner for Global Classrooms. In this capacity, MISTI program managers work with faculty members to structure their programs and help with finding partners abroad, student recruitment, selection, housing, and more. MISTI can also provide funding for certain Global Classrooms or help faculty members find funding.
An example is a Global Classroom in South Africa that is led by Bruce Walker, who is a professor of the practice in the Department of Biology as well as a core member of the Ragon Institute. Walker’s course has been going on in one form or another for more than 20 years. Since 2017, MISTI has partnered with Walker to provide support in a variety of ways.
Through the class, HST. 434 (Evolution of an Epidemic), students from across the Institute meet traditional healers, which are the first line of care for many locals. They also meet with mothers and their HIV-infected babies, young women at risk, local doctors and researchers, and more.
“It’s really important to get a chance to talk to young women at risk and really understand what their challenges are,” Walker says. “A lot of that has to do with lack of empowerment.”
Another recently launched Global Classroom is addressing sustainability in the Amazon. Andre Hamelberg ’24 traveled to Manaus, Brazil, in the Amazon region during the January Independent Activities Period (IAP) this past year. Working with local college students, he designed more sustainable packaging based on locally available materials.
“We had to find our way to communicate with each other, which was a really unique experience,” Hamelberg says. “A lot of us became really good friends. That will always stick with me.”
The experience led Hamelberg to return to Manaus this summer, where he is working with a local plastic manufacturer. It also changed Hamelberg’s perspective on his career.
“I have a long-term dream of becoming an entrepreneur, and I’m hoping I can work on improving sustainability,” Hamelberg says. “That was shaped from the Global Classroom program.”
A highlight for many students is getting an up-close look at the local culture.
“The program was a special opportunity,” Hamelberg says. “We really got to ingrain ourselves in the culture here, which I think was essential to our learning. We got the chance to be part of a small, tight-knit community.”
Helping students find their paths
MISTI’s team is careful to note that Global Classrooms are learning experiences rather than humanitarian missions.
“It’s not like we’re deploying students to go fix things all over the world,” Julich Perez says. “We’re deploying students to go learn about the nature of these challenges from local practitioners, researchers, faculty, and students. MISTI is very much trying to educate students and give them the skills to become changemakers in their future careers.”
Much of that learning is enabled by the setting of the Global Classroom.
“For every Global Classroom, the location is critical,” Julich Perez says. “For instance, if students are studying hydrology, we have a Global Classroom in Venice where students are studying the system that mitigates the sea level rise and its impact on the city. It’s very important for them to go and see the system for themselves and to work with local students on that project. Global Classroom is about that in-situ learning.”
Walker has seen firsthand how exposing students to problems can inspire them to contribute to solutions. He says the experience in his class has driven many Global Classroom alumni to work in public health.
“There’s no substitute for talking to the people that are actually being impacted by a disease,” Walker says. “It’s something that you don’t get in the classroom in terms of student understanding and seeing for themselves what the facilities look like, how constrained they are, chatting with people their own age that are in desperate situations. It opens up a whole new perspective.”
The Global Classrooms program also aligns well with MIT’s mission of equipping students to serve the world, says Julich Perez.
“MIT is all about solving big challenges, and the Global Classroom program is helping students understand those challenges and giving them the skills to be able to solve them in the future,” Julich Perez says.
Three MIT professors named 2024 Vannevar Bush FellowsDomitilla Del Vecchio and Themis Sapsis of MechE and Mehrdad Jazayeri of BCS will each receive up to $3 million for blue-sky research.The U.S. Department of Defense (DoD) has announced three MIT professors among the members of the 2024 class of the Vannevar Bush Faculty Fellowship (VBFF). The fellowship is the DoD’s flagship single-investigator award for research, inviting the nation's most talented researchers to pursue ambitious ideas that defy conventional boundaries.
Domitilla Del Vecchio, professor of mechanical engineering and biological engineering and the Grover M. Hermann Professor in Health Sciences and Technology; Mehrdad Jazayeri, professor of brain and cognitive sciences and an investigator at the McGovern Institute for Brain Research; and Themistoklis Sapsis, the William I. Koch Professor of Mechanical Engineering and director of the Center for Ocean Engineering are among the 11 university scientists and engineers chosen for this year’s fellowship class. They join an elite group of approximately 50 fellows from previous class years.
“The Vannevar Bush Faculty Fellowship is more than a prestigious program,” said Bindu Nair, director of the Basic Research Office in the Office of the Under Secretary of Defense for Research and Engineering, in a press release. “It's a beacon for tenured faculty embarking on groundbreaking ‘blue sky' research.”
Research topics
Each fellow receives up to $3 million over a five-year term to pursue cutting-edge projects. Research topics in this year’s class span a range of disciplines, including materials science, cognitive neuroscience, quantum information sciences, and applied mathematics. While pursuing individual research endeavors, Fellows also leverage the unique opportunity to collaborate directly with DoD laboratories, fostering a valuable exchange of knowledge and expertise.
Del Vecchio, whose research interests include control and dynamical systems theory and systems and synthetic biology, will investigate the molecular underpinnings of analog epigenetic cell memory, then use what they learn to “establish unprecedented engineering capabilities for creating self-organizing and reconfigurable multicellular systems with graded cell fates.”
“With this fellowship, we will be able to explore the limits to which we can leverage analog memory to create multicellular systems that autonomously organize in permanent, but reprogrammable, gradients of cell fates and can be used for creating next-generation tissues and organoids with dramatically increased sophistication,” she says, honored to have been selected.
Jazayeri wants to understand how the brain gives rise to cognitive and emotional intelligence. The engineering systems being built today lack the hallmarks of human intelligence, explains Jazayeri. They neither learn quickly nor generalize their knowledge flexibly. They don’t feel emotions or have emotional intelligence.
Jazayeri plans to use the VBFF award to integrate ideas from cognitive science, neuroscience, and machine learning with experimental data in humans, animals, and computer models to develop a computational understanding of cognitive and emotional intelligence.
“I’m honored and humbled to be selected and excited to tackle some of the most challenging questions at the intersection of neuroscience and AI,” he says.
“I am humbled to be included in such a select group,” echoes Sapsis, who will use the grant to research new algorithms and theory designed for the efficient computation of extreme event probabilities and precursors, and for the design of mitigation strategies in complex dynamical systems.
Examples of Sapsis’s work include risk quantification for extreme events in human-made systems; climate events, such as heat waves, and their effect on interconnected systems like food supply chains; and also “mission-critical algorithmic problems such as search and path planning operations for extreme anomalies,” he explains.
VBFF impact
Named for Vannevar Bush PhD 1916, an influential inventor, engineer, former professor, and dean of the School of Engineering at MIT, the highly competitive fellowship, formerly known as the National Security Science and Engineering Faculty Fellowship, aims to advance transformative, university-based fundamental research. Bush served as the director of the U.S. Office of Scientific Research and Development, and organized and led American science and technology during World War II.
“The outcomes of VBFF-funded research have transformed entire disciplines, birthed novel fields, and challenged established theories and perspectives,” said Nair. “By contributing their insights to DoD leadership and engaging with the broader national security community, they enrich collective understanding and help the United States leap ahead in global technology competition.”
Roadmap details how to improve exoplanet exploration using the JWSTScientists created the step-by-step guide to unlock the potential of NASA’s James Webb Space Telescope for identifying habitable worlds in the universe.The launch of NASA’s James Webb Space Telescope (JWST) in 2021 kicked off an exciting new era for exoplanet research, especially for scientists looking at terrestrial planets orbiting stars other than our sun. But three years into the telescope’s mission, some scientists have run into challenges that have slowed down progress.
In a recent paper published in Nature Astronomy, the TRAPPIST-1 JWST Community Initiative lays out a step-by-step roadmap to overcome the challenges they faced while studying the TRAPPIST-1 system by improving the efficiency of data gathering to benefit the astronomy community at large.
“A whole community of experts came together to tackle these complex cross-disciplinary challenges to design the first multiyear observational strategy to give JWST a fighting chance at identifying habitable worlds over its lifetime,” says Julien de Wit, an associate professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS) and one of the lead authors of the paper.
Two-for-one deal
Located 41 light years from Earth, the TRAPPIST-1 system with its seven planets presents a unique opportunity to study a large system with multiple planets of different compositions, similar to our own solar system.
“It's a dream target: You have not one, but maybe three, planets in the habitable zone, so you have a way to actually compare in the same system,” says René Doyon from the Université de Montréal, who co-led the study with de Wit. “There are only a handful of well-characterized temperate rocky planets for which we can hope to detect their atmosphere, and most of them are within the TRAPPIST-1 system.”
Astronomers like de Wit and Doyon study exoplanet atmospheres through a technique called transmission spectroscopy, where they look at the way starlight passes through a planet’s potential atmosphere to see what elements are present. Transmission spectra are collected when the planet passes in front of its host star.
The planets within the TRAPPIST system have short orbital periods. As a result, their transits frequently overlap. Transit observation times are usually allotted in five-hour windows, and when scheduled properly, close to half of these can catch at least two transits. This “two-for-one” saves both time and money while doubling data collection.
Stellar contamination
Stars are not uniform; their surfaces can vary in temperature, creating spots that can be hotter or cooler. Molecules like water vapor can condense in cool spots and interfere with transmission spectra. Stellar information like this can be difficult to disentangle from the planetary signal and give false indications of a planet’s atmospheric composition, creating what’s known as “stellar contamination.” While it has often been ignored, the improved capabilities of the JWST have revealed the challenges stellar contamination introduces when studying planetary atmospheres.
EAPS research scientist Ben Rackham ran into these challenges when they derailed his initial PhD research on small exoplanets using the Magellan Telescopes in Chile. He’s now seeing the same problem he first encountered as a graduate student repeating itself with the new JWST data.
“As we predicted from that earlier work with data from ground-based telescopes, the very first spectral signatures we're getting with JWST don't really make any sense in terms of a planetary interpretation,” he says. “The features are not what we would expect to see, and they change from transit to transit.”
Rackham and David Berardo, a postdoc in EAPS, have been working with de Wit on ways to correct for stellar contamination using two different methods: improving models of stellar spectra and using direct observations to derive corrections.
“By observing a star as it rotates, we can use the sensitivity of JWST to get a clearer picture of what its surface looks like, allowing for a more accurate measuring of the atmosphere of planets that transit it,” says Berardo. This, combined with studying back-to-back transits as proposed in the roadmap, collects useful data on the star that can be used to filter out stellar contamination from both future studies and past ones.
Beyond TRAPPIST-1
The current roadmap was born from the efforts of the TRAPPIST JWST Community Initiative to bring together separate programs focused on individual planets, which prevented them from leveraging the optimal transit observation windows.
“We understood early on that this effort would 'take a village' to avoid the efficiency traps of small observation programs,” says de Wit. “Our hope now is that a large-scale community effort guided by the roadmap can be initiated to yield deliverables at a timely pace.” De Wit hopes that it could result in identifying habitable, or inhabitable, worlds around TRAPPIST-1 within a decade.
Both de Wit and Doyon believe that the TRAPPIST-1 system is the best place for conducting fundamental research on exoplanet atmospheres that will extend to studies in other systems. Doyon thinks that “the TRAPPIST-1 system will be useful not only for TRAPPIST-1 itself, but also to learn how to do very precise correction of stellar activity which will be beneficial to many other transmission spectroscopy programs also affected by stellar activity.”
“We have within reach fundamental and transforming answers with a clear roadmap to them,” says de Wit. “We just need to follow it diligently.”
Mission directors announced for the Climate Project at MITThe effort to accelerate climate work at the Institute adds to its leadership team.The Climate Project at MIT has appointed leaders for each of its six focal areas, or Climate Missions, President Sally Kornbluth announced in a letter to the MIT community today.
Introduced in February, the Climate Project at MIT is a major new effort to change the trajectory of global climate outcomes for the better over the next decade. The project will focus MIT’s strengths on six broad climate-related areas where progress is urgently needed. The mission directors in these fields, representing diverse areas of expertise, will collaborate with faculty and researchers across MIT, as well as each other, to accelerate solutions that address climate change.
“The mission directors will be absolutely central as the Climate Project seeks to marshal the Institute’s talent and resources to research, develop, deploy and scale up serious solutions to help change the planet’s climate trajectory,” Kornbluth wrote in her letter, adding: “To the faculty members taking on these pivotal roles: We could not be more grateful for your skill and commitment, or more enthusiastic about what you can help us all achieve, together.”
The Climate Project will expand and accelerate MIT’s efforts to both reduce greenhouse gas emissions and respond to climate effects such as extreme heat, rising sea levels, and reduced crop yields. At the urgent pace needed, the project will help the Institute create new external collaborations and deepen existing ones to develop and scale climate solutions.
The Institute has pledged an initial $75 million to the project, including $25 million from the MIT Sloan School of Management to launch a complementary effort, the new MIT Climate Policy Center. MIT has more than 300 faculty and senior researchers already working on climate issues, in collaboration with their students and staff. The Climate Project at MIT builds on their work and the Institute’s 2021 “Fast Forward” climate action plan.
Richard Lester, MIT’s vice provost for international activities and the Japan Steel Industry Professor of Nuclear Science and Engineering, has led the Climate Project’s formation; MIT will shortly hire a vice president for climate to oversee the project. The six Climate Missions and the new mission directors are as follows:
Decarbonizing energy and industry
This mission supports advances in the electric power grid as well as the transition across all industry — including transportation, computing, heavy production, and manufacturing — to low-emissions pathways.
The mission director is Elsa Olivetti PhD ’07, who is MIT’s associate dean of engineering, the Jerry McAfee Professor in Engineering, and a professor of materials science and engineering since 2014.
Olivetti analyzes and improves the environmental sustainability of materials throughout the life cycle and across the supply chain, by linking physical and chemical processes to systems impact. She researches materials design and synthesis using natural language processing, builds models of material supply and technology demand, and assesses the potential for recovering value from industrial waste through experimental approaches. Olivetti has experience building partnerships across the Institute and working with industry to implement large-scale climate solutions through her role as co-director of the MIT Climate and Sustainability Consortium (MCSC) and as faculty lead for PAIA, an industry consortium on the carbon footprinting of computing.
Restoring the atmosphere, protecting the land and oceans
This mission is centered on removing or storing greenhouse gases that have already been emitted into the atmosphere, such as carbon dioxide and methane, and on protecting ocean and land ecosystems, including food and water systems.
MIT has chosen two mission directors: Andrew Babbin and Jesse Kroll. The two bring together research expertise from two critical domains of the Earth system, oceans and the atmosphere, as well as backgrounds in both the science and engineering underlying our understanding of Earth’s climate. As co-directors, they jointly link MIT’s School of Science and School of Engineering in this domain.
Babbin is the Cecil and Ida Green Career Development Professor in MIT’s Program in Atmospheres, Oceans, and Climate. He is a marine biogeochemist whose specialty is studying the carbon and nitrogen cycle of the oceans, work that is related to evaluating the ocean’s capacity for carbon storage, an essential element of this mission’s work. He has been at MIT since 2017.
Kroll is the Peter de Florez Professor in MIT’s Department of of Civil and Environmental Engineering, a professor of chemical engineering, and the director of the Ralph M. Parsons Laboratory. He is a chemist who studies organic compounds and particulate matter in the atmosphere, in order to better understand how perturbations to the atmosphere, both intentional and unintentional, can affect air pollution and climate.
Empowering frontline communities
This mission focuses on the development of new climate solutions in support of the world’s most vulnerable populations, in areas ranging from health effects to food security, emergency planning, and risk forecasting.
The mission director is Miho Mazereeuw, an associate professor of architecture and urbanism in MIT’s Department of Architecture in the School of Architecture and Planning, and director of MIT’s Urban Risk Lab. Mazereeuw researches disaster resilience, climate change, and coastal strategies. Her lab has engaged in design projects ranging from physical objects to software, while exploring methods of engaging communities and governments in preparedness efforts, skills she brings to bear on building strong collaborations with a broad range of stakeholders.
Mazereeuw is also co-lead of one of the five projects selected in MIT’s Climate Grand Challenges competition in 2022, an effort to help communities prepare by understanding the risk of extreme weather events for specific locations.
Building and adapting healthy, resilient cities
A majority of the world’s population lives in cities, so urban design and planning is a crucial part of climate work, involving transportation, infrastructure, finance, government, and more.
Christoph Reinhart, the Alan and Terri Spoon Professor of Architecture and Climate and director of MIT’s Building Technology Program in the School of Architecture and Planning, is the mission director in this area. The Sustainable Design Lab that Reinhart founded when he joined MIT in 2012 has launched several technology startups, including Mapdwell Solar System, now part of Palmetto Clean Technology, as well as Solemma, makers of an environmental building design software used in architectural practice and education worldwide. Reinhart’s online course on Sustainable Building Design has an enrollment of over 55,000 individuals and forms part of MIT’s XSeries Program in Future Energy Systems.
Inventing new policy approaches
Climate change is a unique crisis. With that in mind, this mission aims to develop new institutional structures and incentives — in carbon markets, finance, trade policy, and more — along with decision support tools and systems for scaling up climate efforts.
Christopher Knittel brings extensive knowledge of these topics to the mission director role. The George P. Shultz Professor and Professor of Applied Economics at the MIT Sloan School of Management, Knittel has produced high-impact research in multiple areas; his studies on emissions and the automobile industry have evaluated fuel-efficiency standards, changes in vehicle fuel efficiency, market responses to fuel-price changes, and the health impact of automobiles.
Beyond that, Knittel has also studied the impact of the energy transition on jobs, conducted high-level evaluations of climate policies, and examined energy market structures. He joined the MIT faculty in 2011. He also serves as the director of the MIT Climate Policy Center, which will work closely with all six missions.
Wild cards
This mission consists of what the Climate Project at MIT calls “unconventional solutions outside the scope of the other missions,” and will have a broad portfolio for innovation.
While all the missions will be charged with encouraging unorthodox approaches within their domains, this mission will seek out unconventional solutions outside the scope of the others, and has a broad mandate for promoting them.
The mission director in this case is Benedetto Marelli, the Associate Professor in MIT’s Department of Civil and Environmental Engineering. Marelli’s research group develops biopolymers and bioinspired materials with reduced environmental impact compared to traditional technologies. He engages with research at multiple scales, including nanofabrication, and the research group has conducted extensive work on food security and safety while exploring new techniques to reduce waste through enhanced food preservation and to precisely deliver agrochemicals in plants and in soil.
As Lester and other MIT leaders have noted, the Climate Project at MIT is still being shaped, and will have the flexibility to accommodate a wide range of projects, partnerships, and approaches needed for thoughtful, fast-moving change. By filling out the leadership structure, today’s announcement is a major milestone in making the project operational.
In addition to the six Climate Missions, the Climate Project at MIT includes Climate Frontier Projects, which are efforts launched by these missions, and a Climate HQ, which will support fundamental research, education, and outreach, as well as new resources to connect research to the practical work of climate response.
Study across multiple brain regions discerns Alzheimer’s vulnerability and resilience factorsGenomics and lab studies reveal numerous findings, including a key role for Reelin amid neuronal vulnerability, and for choline and antioxidants in sustaining cognition.An open-access MIT study published today in Nature provides new evidence for how specific cells and circuits become vulnerable in Alzheimer’s disease, and hones in on other factors that may help some people show resilience to cognitive decline, even amid clear signs of disease pathology.
To highlight potential targets for interventions to sustain cognition and memory, the authors engaged in a novel comparison of gene expression across multiple brain regions in people with or without Alzheimer’s disease, and conducted lab experiments to test and validate their major findings.
Brain cells all have the same DNA but what makes them differ, both in their identity and their activity, are their patterns of how they express those genes. The new analysis measured gene expression differences in more than 1.3 million cells of more than 70 cell types in six brain regions from 48 tissue donors, 26 of whom died with an Alzheimer’s diagnosis and 22 of whom without. As such, the study provides a uniquely large, far-ranging, and yet detailed accounting of how brain cell activity differs amid Alzheimer’s disease by cell type, by brain region, by disease pathology, and by each person’s cognitive assessment while still alive.
“Specific brain regions are vulnerable in Alzheimer’s and there is an important need to understand how these regions or particular cell types are vulnerable,” says co-senior author Li-Huei Tsai, Picower Professor of Neuroscience and director of The Picower Institute for Learning and Memory and the Aging Brain Initiative at MIT. “And the brain is not just neurons. It’s many other cell types. How these cell types may respond differently, depending on where they are, is something fascinating we are only at the beginning of looking at.”
Co-senior author Manolis Kellis, professor of computer science and head of MIT’s Computational Biology Group, likens the technique used to measure gene expression comparisons, single-cell RNA profiling, to being a much more advanced “microscope” than the ones that first allowed Alois Alzheimer to characterize the disease’s pathology more than a century ago.
“Where Alzheimer saw amyloid protein plaques and phosphorylated tau tangles in his microscope, our single-cell ‘microscope’ tells us, cell by cell and gene by gene, about thousands of subtle yet important biological changes in response to pathology,” says Kellis. “Connecting this information with the cognitive state of patients reveals how cellular responses relate with cognitive loss or resilience, and can help propose new ways to treat cognitive loss. Pathology can precede cognitive symptoms by a decade or two before cognitive decline becomes diagnosed. If there’s not much we can do about the pathology at that stage, we can at least try to safeguard the cellular pathways that maintain cognitive function.”
Hansruedi Mathys, a former MIT postdoc in the Tsai Lab who is now an assistant professor at the University of Pittsburgh; Carles Boix PhD '22, a former graduate student in Kellis’s lab who is now a postdoc at Harvard Medical School; and Leyla Akay, a graduate student in Tsai’s lab, led the study analyzing the prefrontal cortex, entorhinal cortex, hippocampus, anterior thalamus, angular gyrus, and the midtemporal cortex. The brain samples came from the Religious Order Study and the Rush Memory and Aging Project at Rush University.
Some of the earliest signs of amyloid pathology and neuron loss in Alzheimer’s occur in memory-focused regions called the hippocampus and the entorhinal cortex. In those regions, and in other parts of the cerebral cortex, the researchers were able to pinpoint a potential reason why. One type of excitatory neuron in the hippocampus and four in the entorhinal cortex were significantly less abundant in people with Alzheimer’s than in people without. Individuals with depletion of those cells performed significantly worse on cognitive assessments. Moreover, many vulnerable neurons were interconnected in a common neuronal circuit. And just as importantly, several either directly expressed a protein called Reelin, or were directly affected by Reelin signaling. In all, therefore, the findings distinctly highlight especially vulnerable neurons, whose loss is associated with reduced cognition, that share a neuronal circuit and a molecular pathway.
Tsai notes that Reelin has become prominent in Alzheimer’s research because of a recent study of a man in Colombia. He had a rare mutation in the Reelin gene that caused the protein to be more active, and was able to stay cognitively healthy at an advanced age despite having a strong family predisposition to early-onset Alzheimer’s. The new study shows that loss of Reelin-producing neurons is associated with cognitive decline. Taken together, it might mean that the brain benefits from Reelin, but that neurons that produce it may be lost in at least some Alzheimer’s patients.
“We can think of Reelin as having maybe some kind of protective or beneficial effect,” Akay says. “But we don’t yet know what it does or how it could confer resilience.”
In further analysis the researchers also found that specifically vulnerable inhibitory neuron subtypes identified in a previously study from this group in the prefrontal cortex also were involved in Reelin signaling, further reinforcing the significance of the molecule and its signaling pathway.
To further check their results, the team directly examined the human brain tissue samples and the brains of two kinds of Alzheimer’s model mice. Sure enough, those experiments also showed a reduction in Reelin-positive neurons in the human and mouse entorhinal cortex.
To find factors that might preserve cognition, even amid pathology, the team examined which genes, in which cells, and in which regions, were most closely associated with cognitive resilience, which they defined as residual cognitive function, above the typical cognitive loss expected given the observed pathology.
Their analysis yielded a surprising and specific answer: across several brain regions, astrocytes that expressed genes associated with antioxidant activity and with choline metabolism and polyamine biosynthesis were significantly associated with sustained cognition, even amid high levels of tau and amyloid. The results reinforced previous research findings led by Tsai and Susan Lundqvist in which they showed that dietary supplement of choline helped astrocytes cope with the dysregulation of lipids caused by the most significant Alzheimer’s risk gene, the APOE4 variant. The antioxidant findings also pointed to a molecule that can be found as a dietary supplement, spermidine, which may have anti-inflammatory properties, although such an association would need further work to be established causally.
As before, the team went beyond the predictions from the single-cell RNA expression analysis to make direct observations in the brain tissue of samples. Those that came from cognitively resilient individuals indeed showed increased expression of several of the astrocyte-expressed genes predicted to be associated with cognitive resilience.
New analysis method, open dataset
To analyze the mountains of single-cell data, the researchers developed a new robust methodology based on groups of coordinately-expressed genes (known as “gene modules”), thus exploiting the expression correlation patterns between functionally-related genes in the same module.
“In principle, the 1.3 million cells we surveyed could use their 20,000 genes in an astronomical number of different combinations,” explains Kellis. “In practice, however, we observe a much smaller subset of coordinated changes. Recognizing these coordinated patterns allow us to infer much more robust changes, because they are based on multiple genes in the same functionally-connected module.”
He offered this analogy: With many joints in their bodies, people could move in all kinds of crazy ways, but in practice they engage in many fewer coordinated movements like walking, running, or dancing. The new method enables scientists to identify such coordinated gene expression programs as a group.
While Kellis and Tsai’s labs already reported several noteworthy findings from the dataset, the researchers expect that many more possibly significant discoveries still wait to be found in the trove of data. To facilitate such discovery the team posted handy analytical and visualization tools along with the data on Kellis’s website.
“The dataset is so immensely rich. We focused on only a few aspects that are salient that we believe are very, very interesting, but by no means have we exhausted what can be learned with this dataset,” Kellis says. “We expect many more discoveries ahead, and we hope that young researchers (of all ages) will dive right in and surprise us with many more insights.”
Going forward, Kellis says, the researchers are studying the control circuitry associated with the differentially expressed genes, to understand the genetic variants, the regulators, and other driver factors that can be modulated to reverse disease circuitry across brain regions, cell types, and different stages of the disease.
Additional authors of the study include Ziting Xia, Jose Davila Velderrain, Ayesha P. Ng, Xueqiao Jiang, Ghada Abdelhady, Kyriaki Galani, Julio Mantero, Neil Band, Benjamin T. James, Sudhagar Babu, Fabiola Galiana-Melendez, Kate Louderback, Dmitry Prokopenko, Rudolph E. Tanzi, and David A. Bennett.
Support for the research came from the National Institutes of Health, The Picower Institute for Learning and Memory, The JPB Foundation, the Cure Alzheimer’s Fund, The Robert A. and Renee E. Belfer Family Foundation, Eduardo Eurnekian, and Joseph DiSabato.
Or Hen: Getting to the core of the matterTo understand how everything from atoms to neutron stars behave, he says, requires “abstracting away the details to see main principles that drive everything.”Every now and then, Or Hen, who recently received tenure as an associate professor of physics at MIT, will refer back to a file that he has kept since middle school.
The file is a comprehensive assessment of Hen’s learning disabilities, stemming from dysgraphia — a neurological condition in which someone has difficulty translating their thoughts into written form. Hen was diagnosed with a severe case of dysgraphia as a kindergartener. In middle school, due to an administrative snafu, the school was unaware of his condition and, lacking proper support, Hen failed most of his classes. It wasn’t until one teacher took a special interest that Hen was sent for a detailed assessment of his learning abilities.
That assessment, which Hen did not read until later, when he was well into his undergraduate degree in physics, was for him a revelation and validation.
“I saw a lot of ‘he’s bad at this, and not good at that,’ and it went through all the things I failed at,” Hen recalls. “But there was one test where I did extremely well, and which they had bold-faced.”
It was a test of nonverbal thinking, or abstract comprehension, assessing Hen’s ability to conceptually pare down complex ideas to their fundamental core. In this test, Hen scored in the 99th percentile. Fittingly, by the time Hen read this, he was already immersed in studies of abstract concepts and systems in nuclear physics. On his own, he had gravitated to a field that suited his strengths. Reading the assessment gave him confidence in his own instincts.
“They wrote that ‘this skill is particularly strong in him, and you should push him toward areas that utilize it,’” Hen says.
He brings this up to students at MIT today, not to brag, but as a guide.
“I try to emphasize that there is more than one path to success,” Hen says. “Try to think about what you’re good at, and then do the hard work of finding out what area, group, subfield, can utilize that. Find the thing you bring that’s unique, and build on that. Because then you really shine.”
Today, Hen and his research group are probing the inner workings of the nucleus, the interactions between protons and neutrons, and their even smaller constituents of quarks and gluons, which are the basic ingredients that hold together all the visible matter in the universe. Hen seeks connections between how these particles behave and how their interactions shape the visible universe and extreme astrophysical phenomena such as neutron stars.
“A lot of physics, in my mind, is taking complex systems with lots of details and abstracting away the details to seek the main principles that drive everything,” he says.
A frontier of ideas
Hen grew up in the countryside of Jerusalem, Israel, as part of a moshav — a small Jewish village, where his family worked as farmers, raising chickens for their eggs. In kindergarten, once Hen was diagnosed with dysgraphia, his parents sought out any available resources to help him with his writing.
“I think my mother’s entire salary went toward corrective lessons,” Hen recalls.
In middle school, once the records of his condition were transferred to the school, and an assessment was made of his abilities, Hen was given permission to take his exams orally. Rather than writing his answers, he would sit with a teacher and talk it out. To this day, he credits his loquacious nature to those early, formative years.
“Everyone who knows me knows I talk a lot,” Hen says. “And part of that was the way I was able to learn by talking about the material.”
Once he could work around his dysgraphia, however, Hen soon became bored by the content of his lessons, and in high school, he routinely skipped class. A teacher, seeing his potential, told his parents about an outreach program at the nearby Hebrew University, which Hen’s teacher thought might challenge the boy in ways that high school could not.
In his last two years of high school, Hen took part in the program and enrolled in a couple university classes in programming, which he quickly took to. After graduation, he attended Hebrew University full-time, double-majoring in computer engineering and physics — a topic that he thought he might like, as his older brother had also majored in the topic.
One class, early on in his first year, was especially motivating. The class explored ideas in modern physics, and students got to hear from different physicists about the concepts and phenomena they were tackling in the moment.
“It showed us that the beginning of our studies may be hard and annoying, but this is what you’re working toward,” Hen says. “In that class, we learned about quantum mechanics and nonlinear solids and astrophysics, and it just gave us a view of the frontier of the field.”
At the core
After completing his undergraduate degrees, Hen joined the Israeli Defense Forces, which is a mandatory service for all Israeli citizens. He spent seven years in the army, working as a researcher in a physics laboratory.
In tandem with his military service, Hen was also pursuing a PhD in physics, and would make the short trip to Tel-Aviv University once a week and on weekends to work on his degree. There, he got to know an eccentric and beloved professor who took a chance on Hen and offered him a rare opportunity: to travel to the United States to help build a new particle detector. The detector would be based at Jefferson Laboratory, a facility funded by the U.S. Department of Energy that houses a huge particle accelerator, designed to collide beams of electrons with various atomic nuclei.
With a particle detector, physicists could essentially snap pictures of a collision and its aftermath, to tease out the subatomic constituents and their properties, and how they interact to make up an atom’s nuclear structure.
Hen spent a summer at the facility, helping to build a neutron detector that physicists hoped would shed light on “short-range correlations” — extremely brief, quantum-mechanical fluctuations that can occur between some protons and neutrons within an atom’s nucleus. When these particles get so close as to touch each other, their interactions become stronger, though only for a moment before they flit away. It’s thought that these short-range correlations are the source of most of the kinetic energy in a nucleus, which itself is the basis of all visible matter in the universe.
“More than half the kinetic energy in a nucleus comes from these weird states,” Hen says. “If you ever want to understand atomic nuclei and visible matter at its core, you have to also understand short-range correlations.”
Helping to build the neutron detector was a gratifying combination of hands-on work and abstract thinking, and from then on, Hen was hooked on experimental nuclear physics.
After completing his PhD, and a thesis on short-range correlations, Hen headed to MIT, where he interviewed for a postdoc position as a Pappalardo Fellow in the Laboratory of Nuclear Science. As he chatted with one person after another, he eventually found himself in the office of then-department head Peter Fisher, who encouraged Hen to also apply for an open faculty position.
A few months later, in 2015, he found himself in the fortunate position of starting at MIT as a postdoc, having already accepted a junior faculty position he would start at MIT 18 months later.
“MIT took a bet on me,” he says. “That’s the unique thing about MIT. They saw something in me that I didn’t see back then, and they supported me.”
Particle connections
In his first years on campus, Hen continued his work in short-range correlations. His group used data from particle accelerators around the world to develop a universal understanding of short-range correlations in a way that can be applied across many scales. It could, for instance, predict how the interactions would determine correlations in one type of atom versus another, and shape the behavior of much more dense and extreme phenomena such as neutron stars.
Hen also expanded into the field of neutrinos, which are nearly massless particles that are the most abundant particles in the universe. The properties of neutrinos are thought to be the key to the origins of matter, though neutrinos are notoriously difficult to study in detail because their detection requires detailed understanding of their interaction with atomic nuclei. Hen found that, instead of depending on the elusive interactions of neutrinos, there might be a way to abstract that behavior to that of a more detectable particle, to better understand the neutrino itself.
By analyzing data from electron-beam accelerators around the world, his group founded the “electrons-for-neutrinos” effort, which developed a framework that essentially transposed the interactions of an electron to describe how a neutrino would behave under similar circumstances — a tool that will help physicists interpret data from hard-to-pin-down neutrino experiments.
Reflecting on how he determines which direction to take his research, Hen says: “I have a big nose, and I like to talk to people and understand what they’re doing and whether can I do something there or not. I like to build communities, bring in people with different abilities, and do something big together, where the whole is greater than the sum of its parts.”
Big science
Hen got a chance to start up a big-science collaboration, as part of the Electron-Ion Collider (EIC), a concept for a particle accelerator that collides electrons with protons, neutrons, and nuclei to study the particles’ internal structures and how they are held together by the “strong nuclear force,” which is known as the strongest force in nature.
In late 2019, the EIC was a focus of a meeting at MIT, in which physicists from around the world gathered to discuss the project’s recent go-ahead, granted by the U.S. Department of Energy (DoE). The next step was to design a detector, and multiple versions were considered. Hen, who stopped in out of curiosity, wound up joining a community-wide effort to develop a menu of possible detectors that could be built at the EIC.
Hen then took a leadership role in the next step to put forward a specific detector design for the DoE to fund. Working closely with physicists Tanja Horn and John Lajoie, they called experts to join the effort, eventually gathering physicists from 98 institutions. Thanks to their collaborative efforts the DoE ultimately chose their design over a competing one. Hen and his colleagues subsequently reached out to that other group to join forces to further evolve and fine-tune the design.
“We combined strengths,” Hen says. “We are doing big science. And when you do big science, there’s lots of talented people involved. I’ve learned through this process that it’s all about how you interact with people and adapt yourself to do science, together.”
Today, Hen is overseeing aspects of the EIC’s science community that is leading its development, which is projected to break ground in the next few years. In the meantime, he continues to expand projects in his research group, and works to mentor his students and postdocs, just as he was supported through his early career.
“I’m a very fortunate person, in that I had so many mentors in my life, and they all believed in me and saw things I didn’t,” Hen says. “They noticed that I’m different in whichever capacity, and tried to squeeze that lemon. That was a big thing for me.”
MIT affiliates named 2024 HHMI InvestigatorsFour faculty members and four others with MIT ties are recognized for pushing the boundaries of science and for creating highly inclusive and collaborative research environments.The Howard Hughes Medical Institute (HHMI) today announced its 2024 investigators, four of whom hail from the School of Science at MIT: Steven Flavell, Mary Gehring, Mehrad Jazayeri, and Gene-Wei Li.
Four others with MIT ties were also honored: Jonathan Abraham, graduate of the Harvard/MIT MD-PhD Program; Dmitriy Aronov PhD ’10; Vijay Sankaran, graduate of the Harvard/MIT MD-PhD Program; and Steven McCarroll, institute member of the Broad Institute of MIT and Harvard.
Every three years, HHMI selects roughly two dozen new investigators who have significantly impacted their chosen disciplines to receive a substantial and completely discretionary grant. This funding can be reviewed and renewed indefinitely. The award, which totals roughly $11 million per investigator over the next seven years, enables scientists to continue working at their current institution, paying their full salary while providing financial support for researchers to be flexible enough to go wherever their scientific inquiries take them.
Of the almost 1,000 applicants this year, 26 investigators were selected for their ability to push the boundaries of science and for their efforts to create highly inclusive and collaborative research environments.
“When scientists create environments in which others can thrive, we all benefit,” says HHMI president Erin O’Shea. “These newest HHMI Investigators are extraordinary, not only because of their outstanding research endeavors but also because they mentor and empower the next generation of scientists to work alongside them at the cutting edge.”
Steven Flavell
Steven Flavell, associate professor of brain and cognitive sciences and investigator in the Picower Institute for Learning and Memory, seeks to uncover the neural mechanisms that generate the internal states of the brain, for example, different motivational and arousal states. Working in the model organism, the C. elegans worm, the lab has used genetic, systems, and computational approaches to relate neural activity across the brain to precise features of the animal’s behavior. In addition, they have mapped out the anatomical and functional organization of the serotonin system, mapping out how it modulates the internal state of C. elegans. As a newly named HHMI Investigator, Flavell will pursue research that he hopes will build a foundational understanding of how internal states arise and influence behavior in nervous systems in general. The work will employ brain-wide neural recordings, computational modeling, expansive research on neuromodulatory system organization, and studies of how the synaptic wiring of the nervous system constrains an animal’s ability to generate different internal states.
“I think that it should be possible to define the basis of internal states in C. elegans in concrete terms,” Flavell says. “If we can build a thread of understanding from the molecular architecture of neuromodulatory systems, to changes in brain-wide activity, to state-dependent changes in behavior, then I think we’ll be in a much better place as a field to think about the basis of brain states in more complex animals.”
Mary Gehring
Mary Gehring, professor of biology and core member and David Baltimore Chair in Biomedical Research at the Whitehead Institute for Biomedical Research, studies how plant epigenetics modulates plant growth and development, with a long-term goal of uncovering the essential genetic and epigenetic elements of plant seed biology. Ultimately, the Gehring Lab’s work provides the scientific foundations for engineering alternative modes of seed development and improving plant resiliency at a time when worldwide agriculture is in a uniquely precarious position due to climate changes.
The Gehring Lab uses genetic, genomic, computational, synthetic, and evolutionary approaches to explore heritable traits by investigating repetitive sequences, DNA methylation, and chromatin structure. The lab primarily uses the model plant A. thaliana, a member of the mustard family and the first plant to have its genome sequenced.
“I’m pleased that HHMI has been expanding its support for plant biology, and gratified that our lab will benefit from its generous support,” Gehring says. “The appointment gives us the freedom to step back, take a fresh look at the scientific opportunities before us, and pursue the ones that most interest us. And that’s a very exciting prospect.”
Mehrad Jazayeri
Mehrdad Jazayeri, a professor of brain and cognitive sciences and an investigator at the McGovern Institute for Brain Research, studies how physiological processes in the brain give rise to the abilities of the mind. Work in the Jazayeri Lab brings together ideas from cognitive science, neuroscience, and machine learning with experimental data in humans, animals, and computer models to develop a computational understanding of how the brain creates internal representations, or models, of the external world.
Before coming to MIT in 2013, Jazayeri received his BS in electrical engineering, majoring in telecommunications, from Sharif University of Technology in Tehran, Iran. He completed his MS in physiology at the University of Toronto and his PhD in neuroscience at New York University.
With his appointment to HHMI, Jazayeri plans to explore how the brain enables rapid learning and flexible behavior — central aspects of intelligence that have been difficult to study using traditional neuroscience approaches.
“This is a recognition of my lab's past accomplishments and the promise of the exciting research we want to embark on,” he says. “I am looking forward to engaging with this wonderful community and making new friends and colleagues while we elevate our science to the next level.”
Gene-Wei Li,
Gene-Wei Li, associate professor of biology, has been working on quantifying the amount of proteins cells produce and how protein synthesis is orchestrated within the cell since opening his lab at MIT in 2015.
Li, whose background is in physics, credits the lab’s findings to the skills and communication among his research team, allowing them to explore the unexpected questions that arise in the lab.
For example, two of his graduate student researchers found that the coordination between transcription and translation fundamentally differs between the model organisms E. coli and B. subtilis. In B. subtilis, the ribosome lags far behind RNA polymerase, a process the lab termed “runaway transcription.” The discovery revealed that this kind of uncoupling between transcription and translation is widespread across many species of bacteria, a study that contradicted the long-standing dogma of molecular biology that the machinery of protein synthesis and RNA polymerase work side-by-side in all bacteria.
The support from HHMI enables Li and his team the flexibility to pursue the basic research that leads to discoveries at their discretion.
“Having this award allows us to be bold and to do things at a scale that wasn't possible before,” Li says. “The discovery of runaway transcription is a great example. We didn't have a traditional grant for that.”
License plates of MITCustom plates display expressions of scholarship, creativity, and MIT pride among Institute affiliates.What does your license plate say about you?
In the United States, more than 9 million vehicles carry personalized “vanity” license plates, in which preferred words, digits, or phrases replace an otherwise random assignment of letters and numbers to identify a vehicle. While each state and the District of Columbia maintains its own rules about appropriate selections, creativity reigns when choosing a unique vanity plate. What’s more, the stories behind them can be just as fascinating as the people who use them.
It might not come as a surprise to learn that quite a few MIT community members have participated in such vehicular whimsy. Read on to meet some of them and learn about the nerdy, artsy, techy, and MIT-related plates that color their rides.
A little piece of tech heaven
One of the most recognized vehicles around campus is Samuel Klein’s 1998 Honda Civic. More than just the holder of a vanity plate, it’s an art car — a vehicle that’s been custom-designed as a way to express an artistic idea or theme. Klein’s Civic is covered with hundreds of 5.5-inch floppy disks in various colors, and it sports disks, computer keys, and other techy paraphernalia on the interior. With its double-entendre vanity plate, “DSKDRV” (“disk drive”), the art car initially came into being on the West Coast.
Klein, a longtime affiliate of the MIT Media Lab, MIT Press, and MIT Libraries, first heard about the car from fellow Wikimedian and current MIT librarian Phoebe Ayers. An artistic friend of Ayers’, Lara Wiegand, had designed and decorated the car in Seattle but wanted to find a new owner. Klein was intrigued and decided to fly west to check the Civic out.
“I went out there, spent a whole afternoon seeing how she maintained the car and talking about engineering and mechanisms and the logistics of what’s good and bad,” Klein says. “It had already gone through many iterations.”
Klein quickly decided he was up to the task of becoming the new owner. As he drove the car home across the country, it “got a wide range of really cool responses across different parts of the U.S.”
Back in Massachusetts, Klein made a few adjustments: “We painted the hubcaps, we added racing stripes, we added a new generation of laser-etched glass circuits and, you know, I had my own collection of antiquated technology disks that seemed to fit.”
The vanity plate also required a makeover. In Washington state it was “DISKDRV,” but, Klein says, “we had to shave the license plate a bit because there are fewer letters in Massachusetts.”
Today, the car has about 250,000 miles and an Instagram account. “The biggest challenge is just the disks have to be resurfaced, like a lizard, every few years,” says Klein, whose partner, an MIT research scientist, often parks it around campus. “There’s a small collection of love letters for the car. People leave the car notes. It’s very sweet.”
Marking his place in STEM history
Omar Abudayyeh ’12, PhD ’18, a recent McGovern Fellow at the McGovern Institute for Brain Research at MIT who is now an assistant professor at Harvard Medical School, shares an equally riveting story about his vanity plate, “CRISPR,” which adorns his sport utility vehicle.
The plate refers to the genome-editing technique that has revolutionized biological and medical research by enabling rapid changes to genetic material. As an MIT graduate student in the lab of Professor Feng Zhang, a pioneering contributor to CRISPR technologies, Abudayyeh was highly involved in early CRISPR development for DNA and RNA editing. In fact, he and Jonathan Gootenberg ’13, another recent McGovern Fellow and assistant professor at Harvard Medical School who works closely with Abudayyeh, discovered many novel CRISPR enzymes, such as Cas12 and Cas13, and applied these technologies for both gene therapy and CRISPR diagnostics.
So how did Abudayyeh score his vanity plate? It was all due to his attendance at a genome-editing conference in 2022, where another early-stage CRISPR researcher, Samuel Sternberg, showed up in a car with New York “CRISPR” plates. “It became quite a source of discussion at the conference, and at one of the breaks, Sam and his labmates egged us on to get the Massachusetts license plate,” Abudayyeh explains. “I insisted that it must be taken, but I applied anyway, paying the 70 dollars and then receiving a message that I would get a letter eight to 12 weeks later about whether the plate was available or not. I then returned to Boston and forgot about it until a couple months later when, to my surprise, the plate arrived in the mail.”
While Abudayyeh continues his affiliation with the McGovern Institute, he and Gootenberg recently set up a lab at Harvard Medical School as new faculty members. “We have continued to discover new enzymes, such as Cas7-11, that enable new frontiers, such as programmable proteases for RNA sensing and novel therapeutics, and we’ve applied CRISPR technologies for new efforts in gene editing and aging research,” Abudayyeh notes.
As for his license plate, he says, “I’ve seen instances of people posting about it on Twitter or asking about it in Slack channels. A number of times, people have stopped me to say they read the Walter Isaacson book on CRISPR, asking how I was related to it. I would then explain my story — and describe how I’m actually in the book, in the chapters on CRISPR diagnostics.”
Displaying MIT roots, nerd pride
For some, a connection to MIT is all the reason they need to register a vanity plate — or three. Jeffrey Chambers SM ’06, PhD ’14, a graduate of the Department of Aeronautics and Astronautics, shares that he drives with a Virginia license plate touting his “PHD MIT.” Curtis Smith PhD ’02, professor of the practice in nuclear science and engineering, recently joined the MIT faculty after 33 years at the Idaho National Lab and keeps an “MITGRAD” plate on his convertible in Idaho Falls. Professor of biology Anthony Sinskey ScD ’67 owns several vehicles sporting vanity plates that honor Course 20, which is today the Department of Biological Engineering but has previously been known by Food Technology, Nutrition and Food Science, and Applied Biological Sciences. Sinskey says he has both “MIT 20” and “MIT XX” plates in Massachusetts and New Hampshire.
Christopher Knittel, the George P. Shultz Professor of Applied Economics in the MIT Sloan School of Management, drives with a “TAXCO 2” plate in Massachusetts. (He notes it was supposed to be “TAX CO2” but the space was inadvertently misplaced by the RMV.) “The license plate is meant to represent a critical policy tool for addressing climate change: placing a tax on carbon dioxide emissions,” he says. Such a tax, he argues, “is the most efficient way to address the 'negative externalities' associated with climate change. ... A large portion of my research focuses on understanding the costs and consequences of different environmental policies, so the plate links to my work.”
Several alumni also report driving with plates that reflect their STEM backgrounds and careers. Spencer Webb ’83, an EECS graduate and president of AntennaSys, drives with “ANTENNA.” He explains, “I changed directions eight years out of school and pursued my passion: antennas.” Meanwhile, IT manager and mechanical engineering alumna Sue Kayton ’78 has been the subject of envy with her California “NGINEER” plate: “People leave me notes on my windshield asking if they can buy this plate from me,” she says.
At least three MIT couples have had dual vanity plates. Professors of economics Amy Finkelstein PhD ’01 and Benjamin Olken lovingly drive with dual plates that reflect both their work and their personal connection. “We got ourselves matching his-and-her ‘SUPPLY’ and ‘DEMAND’ license plates as an anniversary present,” Finkelstein says. “What better way is there to express the importance of a relationship? After all, supply is useless without demand and vice versa.”
Says Laura Kiessling ’83, professor of chemistry: “My plate is ‘SLEX.’ This is the abbreviation for a carbohydrate called sialyl Lewis X. It has many roles, including a role in fertilization (sperm-egg binding). It tends to elicit many different reactions from people asking me what it means. Unless they are scientists, I say that my husband [Ron Raines ’80, professor of biology] gave it to me as an inside joke. My husband’s license plate is ‘PROTEIN.’”
Professor of the practice emerita Marcia Bartusiak of MIT Comparative Media Studies/Writing and her husband, Stephen Lowe PhD ’88, previously shared a pair of related license plates. When the couple lived in Virginia, Lowe working as a mathematician on the structure of spiral galaxies and Bartusiak a young science writer focused on astronomy, they had “SPIRAL” and “GALAXY” plates. Now retired in Massachusetts, while they no longer have registered vanity plates, they’ve named their current vehicles “Redshift” and “Blueshift.”
Flori Pierri, assistant curator of science and technology at the MIT Museum, notes: “The MIT Museum has several sets of license plates that belonged to Warren Seamans, the museum’s founder and first director.” The collection includes 1970s iterations of “MITHC” (for MIT Historical Collections, the museum’s first name); a circa 1981 set of “HC-MIT” plates; and a plate reading “MITMUS” after the museum’s name formally changed to MIT Museum.
Other community members have had plates that make a nod to their hobbies — such as Department of Earth, Atmospheric and Planetary Sciences and AeroAstro Professor Sara Seager, whose vehicle sports “ICANOE”; radio meteorologist and MIT Corporate Relations Senior Director Todd Glickman ’77, whose “WMBR 88” plate reflects his longtime connection with the Institute’s student radio station; AeroAstro alumnus Jeremy B. Katz ’09, who has “WAN2FLY” in Washington state; and filmmaker and former MIT pole vaulter Lila French '99, MEng '99, who drove with “SHE VLTR” (“she vaulter”) for a few years following graduation.
Still others use their plates to make poignant or playful statements or to connect with fellow drivers. Constantine Psimopoulos, a visiting lecturer in the MIT Educational Studies Program and former MIT cycling coach, drives with “EYZHN,” which comes from Ancient Greek. “Alexander the Great used to say that he owes ‘zhn’ (‘life’) to his parents, and ‘ey zhn’ (‘living well’) to his teacher Aristotle,” he says. Noelle Merritt ’85, who works at IBM, has “HIJKMNO” in California. “People should say ‘there’s no L’ (there’s Noelle),” she explains. “I was driving down the Pacific Coast Highway and a guy pulled up next to me and indicated I should roll down my window. I did, and he yelled, ‘Are you Noelle?’ He was quite excited he’d cracked the code!”
Closer to campus, Katrina Norman, a lab operations manager in the Institute for Medical Engineering and Science, zooms around Boston with “JETPAK” on her futuristic-looking Mazda Miata. And Julianna Mullen, communications director in the Plasma Science and Fusion Center, says of her “OMGWHY” plate: “It’s just an existential reminder of the importance of scientific inquiry, especially in traffic when someone cuts you off so they can get exactly two car lengths ahead. Oh my God, why did they do it?”
This article has been updated with additional license plate stories from the community.
China-based emissions of three potent climate-warming greenhouse gases spiked in past decade Two studies pinpoint their likely industrial sources and mitigation opportunities.When it comes to heating up the planet, not all greenhouse gases are created equal. They vary widely in their global warming potential (GWP), a measure of how much infrared thermal radiation a greenhouse gas would absorb over a given time frame once it enters the atmosphere. For example, measured over a 100-year period, the GWP of methane is about 28 times that of carbon dioxide (CO2), and the GWPs of a class of greenhouse gases known as perfluorocarbons (PFCs) are thousands of times that of CO2. The lifespans in the atmosphere of different greenhouse gases also vary widely. Methane persists in the atmosphere for around 10 years; CO2 for over 100 years, and PFCs for up to tens of thousands of years.
Given the high GWPs and lifespans of PFCs, their emissions could pose a major roadblock to achieving the aspirational goal of the Paris Agreement on climate change — to limit the increase in global average surface temperature to 1.5 degrees Celsius above preindustrial levels. Now, two new studies based on atmospheric observations inside China and high-resolution atmospheric models show a rapid rise in Chinese emissions over the last decade (2011 to 2020 or 2021) of three PFCs: tetrafluoromethane (PFC-14) and hexafluoroethane (PFC-116) (results in PNAS), and perfluorocyclobutane (PFC-318) (results in Environmental Science & Technology).
Both studies find that Chinese emissions have played a dominant role in driving up global emission levels for all three PFCs.
The PNAS study identifies substantial PFC-14 and PFC-116 emission sources in the less-populated western regions of China from 2011 to 2021, likely due to the large amount of aluminum industry in these regions. The semiconductor industry also contributes to some of the emissions detected in the more economically developed eastern regions. These emissions are byproducts from aluminum smelting, or occur during the use of the two PFCs in the production of semiconductors and flat panel displays. During the observation period, emissions of both gases in China rose by 78 percent, accounting for most of the increase in global emissions of these gases.
The ES&T study finds that during 2011-20, a 70 percent increase in Chinese PFC-318 emissions (contributing more than half of the global emissions increase of this gas) — originated primarily in eastern China. The regions with high emissions of PFC-318 in China overlap with geographical areas densely populated with factories that produce polytetrafluoroethylene (PTFE, commonly used for nonstick cookware coatings), implying that PTFE factories are major sources of PFC-318 emissions in China. In these factories, PFC-318 is formed as a byproduct.
“Using atmospheric observations from multiple monitoring sites, we not only determined the magnitudes of PFC emissions, but also pinpointed the possible locations of their sources,” says Minde An, a postdoc at the MIT Center for Global Change Science (CGCS), and corresponding author of both studies. “Identifying the actual source industries contributing to these PFC emissions, and understanding the reasons for these largely byproduct emissions, can provide guidance for developing region- or industry-specific mitigation strategies.”
“These three PFCs are largely produced as unwanted byproducts during the manufacture of otherwise widely used industrial products,” says MIT professor of atmospheric sciences Ronald Prinn, director of both the MIT Joint Program on the Science and Policy of Global Change and CGCS, and a co-author of both studies. “Phasing out emissions of PFCs as early as possible is highly beneficial for achieving global climate mitigation targets and is likely achievable by recycling programs and targeted technological improvements in these industries.”
Findings in both studies were obtained, in part, from atmospheric observations collected from nine stations within a Chinese network, including one station from the Advanced Global Atmospheric Gases Experiment (AGAGE) network. For comparison, global total emissions were determined from five globally distributed, relatively unpolluted “background” AGAGE stations, as reported in the latest United Nations Environment Program and World Meteorological Organization Ozone Assessment report.
Math program promotes global community for at-risk Ukrainian high schoolers “Our hope is that our students grow and mature as scholars and help rebuild the intellectual potential of Ukraine after the devastating war.”When Sophia Breslavets first heard about Yulia’s Dream, the MIT Department of Mathematics’ Program for Research in Mathematics, Engineering, and Science (PRIMES) for Ukrainian students, Russia had just invaded her country, and she and her family lived in a town 20 miles from the Russian border.
Breslavets had attended a school that emphasized mathematics and physics, took math classes on weekends and during summer breaks, and competed in math Olympiads. “Math was really present in our lives,” she says.
But the war shifted her studies to online. “It still wasn’t like a fully functioning online school,” she recalls. “You can’t socialize.”
So she was grateful to be accepted to the MIT program in 2022. “Yulia’s Dream was a great thing to happen to me personally, because in the beginning, when the war was just starting, I didn't know what to do. This was just a great thing to take your mind off of what's going on outside your window, and you can just kind of get yourself into that and know that you have some work to do, and that was huge.”
Second time around
Breslavets just finished up her second year in the online enrichment program, which offers small-group math instruction in their native language and in English to Ukrainian high schoolers by mentors from around the world. Students wrap up the program by presenting their papers at a conference; several of those papers are published on arXiv.org. This year’s conference featured a guest talk by Professor Pavlo Pylyavskyy of the University of Minnesota Twin Cities, who discussed “Incidences and Tilings,” a joint work with Professor Sergey Fomin of the University of Michigan.
The PRIMES program first organized Yulia’s Dream in 2022, named in memory of Yulia Zdanovska, a talented mathematician and computer scientist who was a teacher with Teach for Ukraine. She was 21 when she was killed in 2022 during Russian shelling in her home city of Kharkiv.
The program fulfills one of PRIMES’s goals, to expose students to the world community of research mathematics by connecting them with early-career mentors. Students must solve a challenging entrance problem set and are then referred by Ukrainian math teachers and leaders at math competitions and math camps.
Yulia’s Dream is coordinated by Dmytro Matvieievskyi, a postdoc at the Kavli Institute in Tokyo, who graduated from School #27 of Kharkiv, and is a recipient of the Bronze medal at the 2012 International Math Olympiad (IMO) as part of the Ukraine Team.
In its first year, from 2022 to 2023, the program drew 48 students in Phase I (reading) and 33 students in Phase II (reading and research). “Our expectation for 2022-23 was that each of six research groups would produce a research paper, and they all did, and one group continued working and produced an extra paper a few months after, for a total of seven papers. Three papers are now on arXiv.org, which is a mark of quality. This went beyond our expectations.”
This past year, the program provided guided reading and research supervision to 32 students. “We conduct thorough selection and provide opportunities to all Ukrainian students capable of doing advanced reading and/or research at the requisite level,” says PRIMES’s director Slava Gerovitch PhD ’99.
MIT pipeline
Several students participated in both years, and at least two have been accepted to MIT.
One of those students is two-time Yulia’s Dream participant Nazar Korniichuk, who had attended a high school in Kyiv that specialized in mathematics and physics when his education was disrupted by the war.
“I was confused and did not know which way I should go,” he recalls. “But then I saw the program Yulia's Dream, and the desire to try real mathematical research ignited.”
In his first year in the program, participation was a challenge. “On the one hand, it was very difficult, because in certain periods there was no electricity and no water. There was always stress and uncertainty about tomorrow. But on the other hand, because there was a war, it motivated me to do mathematics even more, especially during periods when there was no electricity or water.”
He did complete his paper, with Kostiantyn Molokanov and Severyn Khomych, and with mentor Darij Grinberg PhD ’16, a professor of mathematics at Drexel University: “The Pak–Postnikov and Naruse skew hook length formulas: A new proof” (2 Oct 2023; arXiv.org, 27 Oct 2023).
Korniichuk completed his second round from his new home in Newton, Massachusetts, to which his family had migrated last summer. At the recent conference, he presented his paper, with co-authors Kostiantyn Molokanov and Severyn Khomych, “Affine root systems via Lyndon words,” that they worked on with mentor Professor Oleksandr Tsymbaliuk of Purdue University.
“Yulia’s Dream was a very unique experience for me,” says Korniichuk, who plans to study math and computer science at MIT. “I had the opportunity to work on a difficult topic for a long time and then take part in writing an article. Although these years have been difficult, this program encouraged me to go forward.”
Real research
What makes the program work is providing a university level of instruction in mathematics research, to prepare high school students for top mathematics programs. In this case, it provides Ukrainian students an alternative route to reach their educational goals.
The core philosophy of the Yulia’s Dream experience is to provide “the best possible approximation to real mathematical research,” math professor and PRIMES chief research advisor Pavel Etingof told attendees at the 2024 conference. Etingof was born in Ukraine.
“In particular, all projects have to be real — i.e., of interest to professional research mathematicians — and the reading groups should be a bridge towards real mathematics as well. Also, the time frame of Yulia’s Dream is closer to that of real mathematical research than it is in any other high school research program: the students work on their projects for a whole year!”
Other principles include an emphasis on writing and collaboration, with students working on teams with undergraduates, graduate students, postdocs, and faculty. There is also an emphasis on computer-assisted math, which “not only allows participation of high school students as equal members of our research teams, but also allows them to grasp abstract mathematical notions more easily,” says Pavel. “If such notions (such as group, ring, module, etc.) have an incarnation in the familiar digital world, they are less scary.”
Breslavets says that she especially appreciates the collaboration part of the program. Now 16, Breslavets just finished her second year with Yulia’s Dream, and with Andrii Smutchak presented “Double groupoids,” as mentored by University of Alberta professor Harshit Yadav. She says that they began working on the paper in October, and it took about three months to write.
This year’s session was easier for her to participate in, because in summer 2022, her parents found her a host family in Connecticut so that she could transfer to St. Bernard’s School. Even with her new school’s great curriculum, she is grateful for the Yulia’s Dream program.
“Our high school program is considered to be advanced, and we have a class that’s called math research, but it’s definitely not the same, because [with Yulia’s Dream] you're working with people who actually do that for a living,” she says. “I learned a lot from both of my mentors. It’s so collaborative. They can give you feedback, and they can be honest about it.”
She says she misses her Ukrainian math community, which drifted apart after the Covid-19 pandemic and because of the war, but reports finding a new one with Yulia’s Dream. “I actually met a lot of new people,” she says.
Group collaboration is a huge goal for PRIMES director Slava Gerovitch.
“Yulia’s Dream reflects the international nature of the mathematical community, with the mentors coming from different countries and working together with the students to advance knowledge for the whole of humanity. Our hope is that our students grow and mature as scholars and help rebuild the intellectual potential of Ukraine after the devastating war,” says Gerovitch.
Applications for next year’s program are now open. Math graduate students and postdocs are also invited to apply to be a mentor. Weekly meetings begin in October, and culminate in a June 2025 conference to present papers.
Astronomers spot a highly “eccentric” planet on its way to becoming a hot JupiterThe planet’s wild orbit offers clues to how such large, hot planets take shape.Hot Jupiters are some of the most extreme planets in the galaxy. These scorching worlds are as massive as Jupiter, and they swing wildly close to their star, whirling around in a few days compared to our own gas giant’s leisurely 4,000-day orbit around the sun.
Scientists suspect, though, that hot Jupiters weren’t always so hot and in fact may have formed as “cold Jupiters,” in more frigid, distant environs. But how they evolved to be the star-hugging gas giants that astronomers observe today is a big unknown.
Now, astronomers at MIT, Penn State University, and elsewhere have discovered a hot Jupiter “progenitor” — a sort of juvenile planet that is in the midst of becoming a hot Jupiter. And its orbit is providing some answers to how hot Jupiters evolve.
The new planet, which astronomers labeled TIC 241249530 b, orbits a star that is about 1,100 light-years from Earth. The planet circles its star in a highly “eccentric” orbit, meaning that it comes extremely close to the star before slinging far out, then doubling back, in a narrow, elliptical circuit. If the planet was part of our solar system, it would come 10 times closer to the sun than Mercury, before hurtling out, just past Earth, then back around. By the scientists’ estimates, the planet’s stretched-out orbit has the highest eccentricity of any planet detected to date.
The new planet’s orbit is also unique in its “retrograde” orientation. Unlike the Earth and other planets in the solar system, which orbit in the same direction as the sun spins, the new planet travels in a direction that is counter to its star’s rotation.
The team ran simulations of orbital dynamics and found that the planet’s highly eccentric and retrograde orbit are signs that it is likely evolving into a hot Jupiter, through “high-eccentricity migration” — a process by which a planet’s orbit wobbles and progressively shrinks as it interacts with another star or planet on a much wider orbit.
In the case of TIC 241249530 b, the researchers determined that the planet orbits around a primary star that itself orbits around a secondary star, as part of a stellar binary system. The interactions between the two orbits — of the planet and its star — have caused the planet to gradually migrate closer to its star over time.
The planet’s orbit is currently elliptical in shape, and the planet takes about 167 days to complete a lap around its star. The researchers predict that in 1 billion years, the planet will migrate into a much tighter, circular orbit, when it will then circle its star every few days. At that point, the planet will have fully evolved into a hot Jupiter.
“This new planet supports the theory that high eccentricity migration should account for some fraction of hot Jupiters,” says Sarah Millholland, assistant professor of physics in MIT’s Kavli Institute for Astrophysics and Space Research. “We think that when this planet formed, it would have been a frigid world. And because of the dramatic orbital dynamics, it will become a hot Jupiter in about a billion years, with temperatures of several thousand kelvin. So it’s a huge shift from where it started.”
Millholland and her colleagues have published their findings today in the journal Nature. Her co-authors are MIT undergraduate Haedam Im, lead author Arvind Gupta of Penn State University and NSF NOIRLab, and collaborators at multiple other universities, institutions, and observatories.
“Radical seasons”
The new planet was first spotted in data taken by NASA’s Transiting Exoplanet Survey Satellite (TESS), an MIT-led mission that monitors the brightness of nearby stars for “transits,” or brief dips in starlight that could signal the presence of a planet passing in front of, and temporarily blocking, a star’s light.
On Jan. 12, 2020, TESS picked up a possible transit of the star TIC 241249530. Gupta and his colleagues at Penn State determined that the transit was consistent with a Jupiter-sized planet crossing in front of the star. They then acquired measurements from other observatories of the star’s radial velocity, which estimates a star’s wobble, or the degree to which it moves back and forth, in response to other nearby objects that might gravitationally tug on the star.
Those measurements confirmed that a Jupiter-sized planet was orbiting the star and that its orbit was highly eccentric, bringing the planet extremely close to the star before flinging it far out.
Prior to this detection, astronomers had known of only one other planet, HD 80606 b, that was thought to be an early hot Jupiter. That planet, discovered in 2001, held the record for having the highest eccentricity, until now.
“This new planet experiences really dramatic changes in starlight throughout its orbit,” Millholland says. “There must be really radical seasons and an absolutely scorched atmosphere every time it passes close to the star.”
“Dance of orbits”
How could a planet have fallen into such an extreme orbit? And how might its eccentricity evolve over time? For answers, Im and Millholland ran simulations of planetary orbital dynamics to model how the planet may have evolved throughout its history and how it might carry on over hundreds of millions of years.
The team modeled the gravitational interactions between the planet, its star, and the second nearby star. Gupta and his colleagues had observed that the two stars orbit each other in a binary system, while the planet is simultaneously orbiting the closer star. The configuration of the two orbits is somewhat like a circus performer twirling a hula hoop around her waist, while spinning a second hula hoop around her wrist.
Millholland and Im ran multiple simulations, each with a different set of starting conditions, to see which condition, when run forward over several billions of years, produced the configuration of planetary and stellar orbits that Gupta’s team observed in the present day. They then ran the best match even further into the future to predict how the system will evolve over the next several billion years.
These simulations revealed that the new planet is likely in the midst of evolving into a hot Jupiter: Several billion years ago, the planet formed as a cold Jupiter, far from its star, in a region cold enough to condense and take shape. Newly formed, the planet likely orbited the star in a circular path. This conventional orbit, however, gradually stretched and grew eccentric, as it experienced gravitational forces from the star’s misaligned orbit with its second, binary star.
“It’s a pretty extreme process in that the changes to the planet’s orbit are massive,” Millholland says. “It’s a big dance of orbits that’s happening over billions of years, and the planet’s just going along for the ride.”
In another billion years, the simulations show that the planet’s orbit will stabilize in a close-in, circular path around its star.
“Then, the planet will fully become a hot Jupiter,” Millholland says.
The team’s observations, along with their simulations of the planet’s evolution, support the theory that hot Jupiters can form through high eccentricity migration, a process by which a planet gradually moves into place via extreme changes to its orbit over time.
“It’s clear not only from this, but other statistical studies too, that high eccentricity migration should account for some fraction of hot Jupiters,” Millholland notes. “This system highlights how incredibly diverse exoplanets can be. They are mysterious other worlds that can have wild orbits that tell a story of how they got that way and where they’re going. For this planet, it’s not quite finished its journey yet.”
“It is really hard to catch these hot Jupiter progenitors ‘in the act’ as they undergo their super eccentric episodes, so it is very exciting to find a system that undergoes this process,” says Smadar Naoz, a professor of physics and astronomy at the University of California at Los Angeles, who was not involved with the study. “I believe that this discovery opens the door to a deeper understanding of the birth configuration of the exoplanetary system.”
Study reveals how an anesthesia drug induces unconsciousnessPropofol, a drug commonly used for general anesthesia, derails the brain’s normal balance between stability and excitability.There are many drugs that anesthesiologists can use to induce unconsciousness in patients. Exactly how these drugs cause the brain to lose consciousness has been a longstanding question, but MIT neuroscientists have now answered that question for one commonly used anesthesia drug.
Using a novel technique for analyzing neuron activity, the researchers discovered that the drug propofol induces unconsciousness by disrupting the brain’s normal balance between stability and excitability. The drug causes brain activity to become increasingly unstable, until the brain loses consciousness.
“The brain has to operate on this knife’s edge between excitability and chaos. It’s got to be excitable enough for its neurons to influence one another, but if it gets too excitable, it spins off into chaos. Propofol seems to disrupt the mechanisms that keep the brain in that narrow operating range,” says Earl K. Miller, the Picower Professor of Neuroscience and a member of MIT’s Picower Institute for Learning and Memory.
The new findings, reported today in Neuron, could help researchers develop better tools for monitoring patients as they undergo general anesthesia.
Miller and Ila Fiete, a professor of brain and cognitive sciences, the director of the K. Lisa Yang Integrative Computational Neuroscience Center (ICoN), and a member of MIT’s McGovern Institute for Brain Research, are the senior authors of the new study. MIT graduate student Adam Eisen and MIT postdoc Leo Kozachkov are the lead authors of the paper.
Losing consciousness
Propofol is a drug that binds to GABA receptors in the brain, inhibiting neurons that have those receptors. Other anesthesia drugs act on different types of receptors, and the mechanism for how all of these drugs produce unconsciousness is not fully understood.
Miller, Fiete, and their students hypothesized that propofol, and possibly other anesthesia drugs, interfere with a brain state known as “dynamic stability.” In this state, neurons have enough excitability to respond to new input, but the brain is able to quickly regain control and prevent them from becoming overly excited.
Previous studies of how anesthesia drugs affect this balance have found conflicting results: Some suggested that during anesthesia, the brain shifts toward becoming too stable and unresponsive, which leads to loss of consciousness. Others found that the brain becomes too excitable, leading to a chaotic state that results in unconsciousness.
Part of the reason for these conflicting results is that it has been difficult to accurately measure dynamic stability in the brain. Measuring dynamic stability as consciousness is lost would help researchers determine if unconsciousness results from too much stability or too little stability.
In this study, the researchers analyzed electrical recordings made in the brains of animals that received propofol over an hour-long period, during which they gradually lost consciousness. The recordings were made in four areas of the brain that are involved in vision, sound processing, spatial awareness, and executive function.
These recordings covered only a tiny fraction of the brain’s overall activity, so to overcome that, the researchers used a technique called delay embedding. This technique allows researchers to characterize dynamical systems from limited measurements by augmenting each measurement with measurements that were recorded previously.
Using this method, the researchers were able to quantify how the brain responds to sensory inputs, such as sounds, or to spontaneous perturbations of neural activity.
In the normal, awake state, neural activity spikes after any input, then returns to its baseline activity level. However, once propofol dosing began, the brain started taking longer to return to its baseline after these inputs, remaining in an overly excited state. This effect became more and more pronounced until the animals lost consciousness.
This suggests that propofol’s inhibition of neuron activity leads to escalating instability, which causes the brain to lose consciousness, the researchers say.
Better anesthesia control
To see if they could replicate this effect in a computational model, the researchers created a simple neural network. When they increased the inhibition of certain nodes in the network, as propofol does in the brain, network activity became destabilized, similar to the unstable activity the researchers saw in the brains of animals that received propofol.
“We looked at a simple circuit model of interconnected neurons, and when we turned up inhibition in that, we saw a destabilization. So, one of the things we’re suggesting is that an increase in inhibition can generate instability, and that is subsequently tied to loss of consciousness,” Eisen says.
As Fiete explains, “This paradoxical effect, in which boosting inhibition destabilizes the network rather than silencing or stabilizing it, occurs because of disinhibition. When propofol boosts the inhibitory drive, this drive inhibits other inhibitory neurons, and the result is an overall increase in brain activity.”
The researchers suspect that other anesthetic drugs, which act on different types of neurons and receptors, may converge on the same effect through different mechanisms — a possibility that they are now exploring.
If this turns out to be true, it could be helpful to the researchers’ ongoing efforts to develop ways to more precisely control the level of anesthesia that a patient is experiencing. These systems, which Miller is working on with Emery Brown, the Edward Hood Taplin Professor of Medical Engineering at MIT, work by measuring the brain’s dynamics and then adjusting drug dosages accordingly, in real-time.
“If you find common mechanisms at work across different anesthetics, you can make them all safer by tweaking a few knobs, instead of having to develop safety protocols for all the different anesthetics one at a time,” Miller says. “You don’t want a different system for every anesthetic they’re going to use in the operating room. You want one that’ll do it all.”
The researchers also plan to apply their technique for measuring dynamic stability to other brain states, including neuropsychiatric disorders.
“This method is pretty powerful, and I think it’s going to be very exciting to apply it to different brain states, different types of anesthetics, and also other neuropsychiatric conditions like depression and schizophrenia,” Fiete says.
The research was funded by the Office of Naval Research, the National Institute of Mental Health, the National Institute of Neurological Disorders and Stroke, the National Science Foundation Directorate for Computer and Information Science and Engineering, the Simons Center for the Social Brain, the Simons Collaboration on the Global Brain, the JPB Foundation, the McGovern Institute, and the Picower Institute.
Q&A: What past environmental success can teach us about solving the climate crisisIn a new book, Professor Susan Solomon uses previous environmental successes as a source of hope and guidance for mitigating climate change.Susan Solomon, MIT professor of Earth, atmospheric, and planetary sciences (EAPS) and of chemistry, played a critical role in understanding how a class of chemicals known as chlorofluorocarbons were creating a hole in the ozone layer. Her research was foundational to the creation of the Montreal Protocol, an international agreement established in the 1980s that phased out products releasing chlorofluorocarbons. Since then, scientists have documented signs that the ozone hole is recovering thanks to these measures.
Having witnessed this historical process first-hand, Solomon, the Lee and Geraldine Martin Professor of Environmental Studies, is aware of how people can come together to make successful environmental policy happen. Using her story, as well as other examples of success — including combating smog, getting rid of DDT, and more — Solomon draws parallels from then to now as the climate crisis comes into focus in her new book, “Solvable: How we Healed the Earth and How we can do it Again.”
Solomon took a moment to talk about why she picked the stories in her book, the students who inspired her, and why we need hope and optimism now more than ever.
Q: You have first-hand experience seeing how we’ve altered the Earth, as well as the process of creating international environmental policy. What prompted you to write a book about your experiences?
A: Lots of things, but one of the main ones is the things that I see in teaching. I have taught a class called Science, Politics and Environmental Policy for many years here at MIT. Because my emphasis is always on how we’ve actually fixed problems, students come away from that class feeling hopeful, like they really want to stay engaged with the problem.
It strikes me that students today have grown up in a very contentious and difficult era in which they feel like nothing ever gets done. But stuff does get done, even now. Looking at how we did things so far really helps you to see how we can do things in the future.
Q: In the book, you use five different stories as examples of successful environmental policy, and then end talking about how we can apply these lessons to climate change. Why did you pick these five stories?
A: I picked some of them because I’m closer to those problems in my own professional experience, like ozone depletion and smog. I did other issues partly because I wanted to show that even in the 21st century, we’ve actually got some stuff done — that’s the story of the Kigali Amendment to the Montreal Protocol, which is a binding international agreement on some greenhouse gases.
Another chapter is on DDT. One of the reasons I included that is because it had an enormous effect on the birth of the environmental movement in the United States. Plus, that story allows you to see how important the environmental groups can be.
Lead in gasoline and paint is the other one. I find it a very moving story because the idea that we were poisoning millions of children and not even realizing it is so very, very sad. But it’s so uplifting that we did figure out the problem, and it happened partly because of the civil rights movement, that made us aware that the problem was striking minority communities much more than non-minority communities.
Q: What surprised you the most during your research for the book?
A: One of the things that that I didn’t realize and should have, was the outsized role played by one single senator, Ed Muskie of Maine. He made pollution control his big issue and devoted incredible energy to it. He clearly had the passion and wanted to do it for many years, but until other factors helped him, he couldn’t. That's where I began to understand the role of public opinion and the way in which policy is only possible when public opinion demands change.
Another thing about Muskie was the way in which his engagement with these issues demanded that science be strong. When I read what he put into congressional testimony I realized how highly he valued the science. Science alone is never enough, but it’s always necessary. Over the years, science got a lot stronger, and we developed ways of evaluating what the scientific wisdom across many different studies and many different views actually is. That’s what scientific assessment is all about, and it’s crucial to environmental progress.
Q: Throughout the book you argue that for environmental action to succeed, three things must be met which you call the three Ps: a threat much be personal, perceptible, and practical. Where did this idea come from?
A: My observations. You have to perceive the threat: In the case of the ozone hole, you could perceive it because those false-color images of the ozone loss were so easy to understand, and it was personal because few things are scarier than cancer, and a reduced ozone layer leads to too much sun, increasing skin cancers. Science plays a role in communicating what can be readily understood by the public, and that’s important to them perceiving it as a serious problem.
Nowadays, we certainly perceive the reality of climate change. We also see that it’s personal. People are dying because of heat waves in much larger numbers than they used to; there are horrible problems in the Boston area, for example, with flooding and sea level rise. People perceive the reality of the problem and they feel personally threatened.
The third P is practical: People have to believe that there are practical solutions. It’s interesting to watch how the battle for hearts and minds has shifted. There was a time when the skeptics would just attack the whole idea that the climate was changing. Eventually, they decided ‘we better accept that because people perceive it, so let’s tell them that it’s not caused by human activity.’ But it’s clear enough now that human activity does play a role. So they’ve moved on to attacking that third P, that somehow it’s not practical to have any kind of solutions. This is progress! So what about that third P?
What I tried to do in the book is to point out some of the ways in which the problem has also become eminently practical to deal with in the last 10 years, and will continue to move in that direction. We’re right on the cusp of success, and we just have to keep going. People should not give in to eco despair; that’s the worst thing you could do, because then nothing will happen. If we continue to move at the rate we have, we will certainly get to where we need to be.
Q: That ties in very nicely with my next question. The book is very optimistic; what gives you hope?
A: I’m optimistic because I’ve seen so many examples of where we have succeeded, and because I see so many signs of movement right now that are going to push us in the same direction.
If we had kept conducting business as usual as we had been in the year 2000, we’d be looking at 4 degrees of future warming. Right now, I think we're looking at 3 degrees. I think we can get to 2 degrees. We have to really work on it, and we have to get going seriously in the next decade, but globally right now over 30 percent of our energy is from renewables. That's fantastic! Let’s just keep going.
Q: Throughout the book, you show that environmental problems won’t be solved by individual actions alone, but requires policy and technology driving. What individual actions can people take to help push for those bigger changes?
A: A big one is choose to eat more sustainably; choose alternative transportation methods like public transportation or reducing the amount of trips that you make. Older people usually have retirement investments, you can shift them over to a social choice funds and away from index funds that end up funding companies that you might not be interested in. You can use your money to put pressure: Amazon has been under a huge amount of pressure to cut down on their plastic packaging, mainly coming from consumers. They’ve just announced they’re not going to use those plastic pillows anymore. I think you can see lots of ways in which people really do matter, and we can matter more.
Q: What do you hope people take away from the book?
A: Hope for their future and resolve to do the best they can getting engaged with it.
Study finds health risks in switching ships from diesel to ammonia fuelAmmonia could be a nearly carbon-free maritime fuel, but without new emissions regulations, its impact on air quality could significantly impact human health.As container ships the size of city blocks cross the oceans to deliver cargo, their huge diesel engines emit large quantities of air pollutants that drive climate change and have human health impacts. It has been estimated that maritime shipping accounts for almost 3 percent of global carbon dioxide emissions and the industry’s negative impacts on air quality cause about 100,000 premature deaths each year.
Decarbonizing shipping to reduce these detrimental effects is a goal of the International Maritime Organization, a U.N. agency that regulates maritime transport. One potential solution is switching the global fleet from fossil fuels to sustainable fuels such as ammonia, which could be nearly carbon-free when considering its production and use.
But in a new study, an interdisciplinary team of researchers from MIT and elsewhere caution that burning ammonia for maritime fuel could worsen air quality further and lead to devastating public health impacts, unless it is adopted alongside strengthened emissions regulations.
Ammonia combustion generates nitrous oxide (N2O), a greenhouse gas that is about 300 times more potent than carbon dioxide. It also emits nitrogen in the form of nitrogen oxides (NO and NO2, referred to as NOx), and unburnt ammonia may slip out, which eventually forms fine particulate matter in the atmosphere. These tiny particles can be inhaled deep into the lungs, causing health problems like heart attacks, strokes, and asthma.
The new study indicates that, under current legislation, switching the global fleet to ammonia fuel could cause up to about 600,000 additional premature deaths each year. However, with stronger regulations and cleaner engine technology, the switch could lead to about 66,000 fewer premature deaths than currently caused by maritime shipping emissions, with far less impact on global warming.
“Not all climate solutions are created equal. There is almost always some price to pay. We have to take a more holistic approach and consider all the costs and benefits of different climate solutions, rather than just their potential to decarbonize,” says Anthony Wong, a postdoc in the MIT Center for Global Change Science and lead author of the study.
His co-authors include Noelle Selin, an MIT professor in the Institute for Data, Systems, and Society and the Department of Earth, Atmospheric and Planetary Sciences (EAPS); Sebastian Eastham, a former principal research scientist who is now a senior lecturer at Imperial College London; Christine Mounaïm-Rouselle, a professor at the University of Orléans in France; Yiqi Zhang, a researcher at the Hong Kong University of Science and Technology; and Florian Allroggen, a research scientist in the MIT Department of Aeronautics and Astronautics. The research appears this week in Environmental Research Letters.
Greener, cleaner ammonia
Traditionally, ammonia is made by stripping hydrogen from natural gas and then combining it with nitrogen at extremely high temperatures. This process is often associated with a large carbon footprint. The maritime shipping industry is betting on the development of “green ammonia,” which is produced by using renewable energy to make hydrogen via electrolysis and to generate heat.
“In theory, if you are burning green ammonia in a ship engine, the carbon emissions are almost zero,” Wong says.
But even the greenest ammonia generates nitrous oxide (N2O), nitrogen oxides (NOx) when combusted, and some of the ammonia may slip out, unburnt. This nitrous oxide would escape into the atmosphere, where the greenhouse gas would remain for more than 100 years. At the same time, the nitrogen emitted as NOx and ammonia would fall to Earth, damaging fragile ecosystems. As these emissions are digested by bacteria, additional N2O is produced.
NOx and ammonia also mix with gases in the air to form fine particulate matter. A primary contributor to air pollution, fine particulate matter kills an estimated 4 million people each year.
“Saying that ammonia is a ‘clean’ fuel is a bit of an overstretch. Just because it is carbon-free doesn’t necessarily mean it is clean and good for public health,” Wong says.
A multifaceted model
The researchers wanted to paint the whole picture, capturing the environmental and public health impacts of switching the global fleet to ammonia fuel. To do so, they designed scenarios to measure how pollutant impacts change under certain technology and policy assumptions.
From a technological point of view, they considered two ship engines. The first burns pure ammonia, which generates higher levels of unburnt ammonia but emits fewer nitrogen oxides. The second engine technology involves mixing ammonia with hydrogen to improve combustion and optimize the performance of a catalytic converter, which controls both nitrogen oxides and unburnt ammonia pollution.
They also considered three policy scenarios: current regulations, which only limit NOx emissions in some parts of the world; a scenario that adds ammonia emission limits over North America and Western Europe; and a scenario that adds global limits on ammonia and NOx emissions.
The researchers used a ship track model to calculate how pollutant emissions change under each scenario and then fed the results into an air quality model. The air quality model calculates the impact of ship emissions on particulate matter and ozone pollution. Finally, they estimated the effects on global public health.
One of the biggest challenges came from a lack of real-world data, since no ammonia-powered ships are yet sailing the seas. Instead, the researchers relied on experimental ammonia combustion data from collaborators to build their model.
“We had to come up with some clever ways to make that data useful and informative to both the technology and regulatory situations,” he says.
A range of outcomes
In the end, they found that with no new regulations and ship engines that burn pure ammonia, switching the entire fleet would cause 681,000 additional premature deaths each year.
“While a scenario with no new regulations is not very realistic, it serves as a good warning of how dangerous ammonia emissions could be. And unlike NOx, ammonia emissions from shipping are currently unregulated,” Wong says.
However, even without new regulations, using cleaner engine technology would cut the number of premature deaths down to about 80,000, which is about 20,000 fewer than are currently attributed to maritime shipping emissions. With stronger global regulations and cleaner engine technology, the number of people killed by air pollution from shipping could be reduced by about 66,000.
“The results of this study show the importance of developing policies alongside new technologies,” Selin says. “There is a potential for ammonia in shipping to be beneficial for both climate and air quality, but that requires that regulations be designed to address the entire range of potential impacts, including both climate and air quality.”
Ammonia’s air quality impacts would not be felt uniformly across the globe, and addressing them fully would require coordinated strategies across very different contexts. Most premature deaths would occur in East Asia, since air quality regulations are less stringent in this region. Higher levels of existing air pollution cause the formation of more particulate matter from ammonia emissions. In addition, shipping volume over East Asia is far greater than elsewhere on Earth, compounding these negative effects.
In the future, the researchers want to continue refining their analysis. They hope to use these findings as a starting point to urge the marine industry to share engine data they can use to better evaluate air quality and climate impacts. They also hope to inform policymakers about the importance and urgency of updating shipping emission regulations.
This research was funded by the MIT Climate and Sustainability Consortium.
Empowering future innovators through a social impact lensThe IDEAS Social Innovation Challenge helps students hone their entrepreneurship skills to create viable ventures for public good.What if testing for Lyme disease were as simple as dropping a tick in a test tube at home, waiting a few minutes, and looking for a change of color?
MIT Sloan Fellow and physician's assistant Erin Dawicki is making it happen, as part of her aspiration to make Lyme testing accessible, affordable, and widespread. She noticed a troubling increase in undetected Lyme disease in her practice and collaborated with fellow MIT students to found Lyme Alert, a startup that has created the first truly at-home Lyme screening kit using nanotechnology.
Lyme Alert focuses on social impact in its mission to deliver faster diagnoses while using its technology to track disease spread. Participating in the 2024 IDEAS Social Innovation Challenge (IDEAS) helped the team refine their solution while keeping impact at the heart of their work. They ultimately won the top prize at the program’s award ceremony in the spring.
Over the past 23 years, IDEAS has fostered a community in which hundreds of entrepreneurial students have developed their innovation skills in collaboration with affected stakeholders, experienced entrepreneurs, and a supportive network of alumni, classmates, and mentors. The 14 teams in the 2024 IDEAS cohort join over 200 alumni teams — many still in operation today — that have received over $1.5 million in seed funding since 2001.
“IDEAS is a great example of experiential learning at MIT: empowering students to ask good questions, explore new frameworks, and propose sustainable interventions to urgent challenges alongside community partners," says Lauren Tyger, assistant dean of social innovation at the Priscilla King Gray Public Service Center (PKG Center) at MIT.
As MIT’s premier social impact incubator housed within the PKG Center, IDEAS prepares students to take their early-stage ideas to the next level. Teams learn how to develop relationships with constituents affected by social issues, propose interventions that yield measurable impact, and create effective social enterprise models.
“This program undoubtedly opened my eyes to the intersection of social impact and entrepreneurship, fields I previously thought to be mutually exclusive,” says Srihitha Dasari, a rising junior in brain and cognitive sciences and co-founder of another award-winning team, PuntoSalud. “It not only provided me with vital skills to advance my own interests in the startup ecosystem, but expanded my network in order to enact change.”
Shaping the “leaders of tomorrow”
Over the course of one semester, IDEAS teams participate in iterative workshops, refine their ideas with mentors, and pitch their solutions to peers and judges. The process helps students transform their concepts into social innovations in health care, finance, climate, education, and many more fields.
The program culminates in an awards ceremony at the MIT Museum, where teams share their final products. This year’s showcase featured a keynote address from Christine Ortiz, professor of materials science and engineering. Her passion for socially-directed science and technology aligns with IDEAS’ focus on social impact.
“I was grateful to be a part of the journey for these 14 teams,” Ortiz says. “IDEAS speaks to the core of what MIT needs: innovators capable of thinking critically about problems within their communities.”
Five teams are selected for awards of $6,000 to $20,000 by a group of experts across a variety of industries who volunteer as judges, and two additional award grants of $2,500 are given to teams that received the most votes through the MIT Solve initiative’s IDEAS virtual showcase.
The teams that received awards this year are: Lyme Alert, which created the first truly at-home tick testing kit for Lyme disease; My Sister’s Keeper, which aims to establish a professional leadership incubator designed specifically for Muslim immigrant women in the United States; Sakhi - Simppl, which created a WhatsApp chatbot that generates responses grounded in accurate, verified knowledge from international health agencies; BendShelters, which provides sustainable, modular, and easily deployable bamboo shelters for displaced populations in Myanmar, a Southeast Asian country under a dictatorship; PuntoSalud, an AI-powered virtual health messaging system that delivers personalized, trustworthy information sourced directly from local hospitals in Argentina; ONE Community, which provides a digital network through which businesses in India at risk of displacement can connect with more customers and partners to ensure sustained and resilient growth; and Mudzi Cooking Project, a social enterprise tackling the challenges faced by women in Chisinga, Malawi, who struggle to access firewood.
As a member of the Science Hub, the PKG Center worked with corporate partner Amazon, which sponsored the top five awards for the first time in 2024. The inaugural Amazon Prizes for Social Good honored the teams’ efforts to use tech to solve social issues.
“Clearly, these students are inspired to give rather than to take, and their work distinguishes them all as the leaders of tomorrow,” says Tye Brady, chief technologist at Amazon Robotics.
All of the teams will refine their ideas over the summer and report back by the start of the next academic year. Additionally, for a period of 16 months the teams that won awards will continue to receive guidance from the PKG Center and a founder support network with the 2023 group of IDEAS grantees.
Tapping MIT’s innovation ecosystem
IDEAS is just one of the PKG Center’s programs that provide opportunities for students to focus on social impact. In tandem with other Institute resources for student innovators, PKG enables students to apply their innovation skills to solve real-world problems while supporting community-informed solutions to systemic challenges.
“The PKG Center is a valued partner in enabling the growing numbers of students who aspire to create impact-focused ventures,” says Don Shobrys, director of MIT Venture Mentoring Service.
In order to make those ventures successful, Tyger explains, “IDEAS teaches students frameworks to deeply understand the systems around a challenge, get to know who’s already addressing it, find gaps, and then design and implement something that will uniquely and sustainably address the challenge. Rather than optimizing for profit alone, IDEAS helps students learn how to optimize for what can produce the most social good or reduce the most harm.”
Tyger notes that although IDEAS’ emphasis on social impact is somewhat unique, it is complemented by MIT’s rich entrepreneurship ecosystem. “There are many resources and people who are incredibly generous with their time — and who above all do it because they know we are all supporting the growth of students,” she says.
This year’s program collaborators included MIT Sandbox, MIT D-Hive, and Arts Startup Incubator, which co-hosted informational sessions for applicants in the fall; BU Law Clinic, D-Lab, and Systems-Awareness Lab leaders, who served as guest speakers throughout the spring; Venture Mentoring Service, which matched teams with mentors; entrepreneurs-in-residence from the Martin Trust Center for MIT Entrepreneurship, who judged final pitches and advised teams; DesignX and the Center for Development and Entrepreneurship at MIT (formerly the Legatum Center), which provided additional support to several teams; MIT Solve, which hosted the teams on their voting platform; and MIT Innovation HQ, which provided space for students to meet one another and exchange ideas.
While IDEAS projects are designed to be a means of transformative change for public good, many students say that the program is transformative for them, as well. “Before IDEAS, I didn’t see myself as an innovator — just someone passionate about solving a problem that I’d heard people facing across diseases,” reflects Anika Wadhera, a rising senior in biological engineering and co-founder of Chronolog Health, a platform revolutionizing chronic illness management. “Now I feel much more confident in my ability to actually make a difference by better understanding the different stakeholders and the factors that are necessary to make a transformative solution.”
Study: Weaker ocean circulation could enhance CO2 buildup in the atmosphereNew findings challenge current thinking on the ocean’s role in storing carbon.As climate change advances, the ocean’s overturning circulation is predicted to weaken substantially. With such a slowdown, scientists estimate the ocean will pull down less carbon dioxide from the atmosphere. However, a slower circulation should also dredge up less carbon from the deep ocean that would otherwise be released back into the atmosphere. On balance, the ocean should maintain its role in reducing carbon emissions from the atmosphere, if at a slower pace.
However, a new study by an MIT researcher finds that scientists may have to rethink the relationship between the ocean’s circulation and its long-term capacity to store carbon. As the ocean gets weaker, it could release more carbon from the deep ocean into the atmosphere instead.
The reason has to do with a previously uncharacterized feedback between the ocean’s available iron, upwelling carbon and nutrients, surface microorganisms, and a little-known class of molecules known generally as “ligands.” When the ocean circulates more slowly, all these players interact in a self-perpetuating cycle that ultimately increases the amount of carbon that the ocean outgases back to the atmosphere.
“By isolating the impact of this feedback, we see a fundamentally different relationship between ocean circulation and atmospheric carbon levels, with implications for the climate,” says study author Jonathan Lauderdale, a research scientist in MIT’s Department of Earth, Atmospheric, and Planetary Sciences. “What we thought is going on in the ocean is completely overturned.”
Lauderdale says the findings show that “we can’t count on the ocean to store carbon in the deep ocean in response to future changes in circulation. We must be proactive in cutting emissions now, rather than relying on these natural processes to buy us time to mitigate climate change.”
His study appears today in the journal Nature Communications.
Box flow
In 2020, Lauderdale led a study that explored ocean nutrients, marine organisms, and iron, and how their interactions influence the growth of phytoplankton around the world. Phytoplankton are microscopic, plant-like organisms that live on the ocean surface and consume a diet of carbon and nutrients that upwell from the deep ocean and iron that drifts in from desert dust.
The more phytoplankton that can grow, the more carbon dioxide they can absorb from the atmosphere via photosynthesis, and this plays a large role in the ocean’s ability to sequester carbon.
For the 2020 study, the team developed a simple “box” model, representing conditions in different parts of the ocean as general boxes, each with a different balance of nutrients, iron, and ligands — organic molecules that are thought to be byproducts of phytoplankton. The team modeled a general flow between the boxes to represent the ocean’s larger circulation — the way seawater sinks, then is buoyed back up to the surface in different parts of the world.
This modeling revealed that, even if scientists were to “seed” the oceans with extra iron, that iron wouldn’t have much of an effect on global phytoplankton growth. The reason was due to a limit set by ligands. It turns out that, if left on its own, iron is insoluble in the ocean and therefore unavailable to phytoplankton. Iron only becomes soluble at “useful” levels when linked with ligands, which keep iron in a form that plankton can consume. Lauderdale found that adding iron to one ocean region to consume additional nutrients robs other regions of nutrients that phytoplankton there need to grow. This lowers the production of ligands and the supply of iron back to the original ocean region, limiting the amount of extra carbon that would be taken up from the atmosphere.
Unexpected switch
Once the team published their study, Lauderdale worked the box model into a form that he could make publicly accessible, including ocean and atmosphere carbon exchange and extending the boxes to represent more diverse environments, such as conditions similar to the Pacific, the North Atlantic, and the Southern Ocean. In the process, he tested other interactions within the model, including the effect of varying ocean circulation.
He ran the model with different circulation strengths, expecting to see less atmospheric carbon dioxide with weaker ocean overturning — a relationship that previous studies have supported, dating back to the 1980s. But what he found instead was a clear and opposite trend: The weaker the ocean’s circulation, the more CO2 built up in the atmosphere.
“I thought there was some mistake,” Lauderdale recalls. “Why were atmospheric carbon levels trending the wrong way?”
When he checked the model, he found that the parameter describing ocean ligands had been left “on” as a variable. In other words, the model was calculating ligand concentrations as changing from one ocean region to another.
On a hunch, Lauderdale turned this parameter “off,” which set ligand concentrations as constant in every modeled ocean environment, an assumption that many ocean models typically make. That one change reversed the trend, back to the assumed relationship: A weaker circulation led to reduced atmospheric carbon dioxide. But which trend was closer to the truth?
Lauderdale looked to the scant available data on ocean ligands to see whether their concentrations were more constant or variable in the actual ocean. He found confirmation in GEOTRACES, an international study that coordinates measurements of trace elements and isotopes across the world’s oceans, that scientists can use to compare concentrations from region to region. Indeed, the molecules’ concentrations varied. If ligand concentrations do change from one region to another, then his surprise new result was likely representative of the real ocean: A weaker circulation leads to more carbon dioxide in the atmosphere.
“It’s this one weird trick that changed everything,” Lauderdale says. “The ligand switch has revealed this completely different relationship between ocean circulation and atmospheric CO2 that we thought we understood pretty well.”
Slow cycle
To see what might explain the overturned trend, Lauderdale analyzed biological activity and carbon, nutrient, iron, and ligand concentrations from the ocean model under different circulation strengths, comparing scenarios where ligands were variable or constant across the various boxes.
This revealed a new feedback: The weaker the ocean’s circulation, the less carbon and nutrients the ocean pulls up from the deep. Any phytoplankton at the surface would then have fewer resources to grow and would produce fewer byproducts (including ligands) as a result. With fewer ligands available, less iron at the surface would be usable, further reducing the phytoplankton population. There would then be fewer phytoplankton available to absorb carbon dioxide from the atmosphere and consume upwelled carbon from the deep ocean.
“My work shows that we need to look more carefully at how ocean biology can affect the climate,” Lauderdale points out. “Some climate models predict a 30 percent slowdown in the ocean circulation due to melting ice sheets, particularly around Antarctica. This huge slowdown in overturning circulation could actually be a big problem: In addition to a host of other climate issues, not only would the ocean take up less anthropogenic CO2 from the atmosphere, but that could be amplified by a net outgassing of deep ocean carbon, leading to an unanticipated increase in atmospheric CO2 and unexpected further climate warming.”
MIT researchers introduce generative AI for databasesThis new tool offers an easier way for people to analyze complex tabular data.A new tool makes it easier for database users to perform complicated statistical analyses of tabular data without the need to know what is going on behind the scenes.
GenSQL, a generative AI system for databases, could help users make predictions, detect anomalies, guess missing values, fix errors, or generate synthetic data with just a few keystrokes.
For instance, if the system were used to analyze medical data from a patient who has always had high blood pressure, it could catch a blood pressure reading that is low for that particular patient but would otherwise be in the normal range.
GenSQL automatically integrates a tabular dataset and a generative probabilistic AI model, which can account for uncertainty and adjust their decision-making based on new data.
Moreover, GenSQL can be used to produce and analyze synthetic data that mimic the real data in a database. This could be especially useful in situations where sensitive data cannot be shared, such as patient health records, or when real data are sparse.
This new tool is built on top of SQL, a programming language for database creation and manipulation that was introduced in the late 1970s and is used by millions of developers worldwide.
“Historically, SQL taught the business world what a computer could do. They didn’t have to write custom programs, they just had to ask questions of a database in high-level language. We think that, when we move from just querying data to asking questions of models and data, we are going to need an analogous language that teaches people the coherent questions you can ask a computer that has a probabilistic model of the data,” says Vikash Mansinghka ’05, MEng ’09, PhD ’09, senior author of a paper introducing GenSQL and a principal research scientist and leader of the Probabilistic Computing Project in the MIT Department of Brain and Cognitive Sciences.
When the researchers compared GenSQL to popular, AI-based approaches for data analysis, they found that it was not only faster but also produced more accurate results. Importantly, the probabilistic models used by GenSQL are explainable, so users can read and edit them.
“Looking at the data and trying to find some meaningful patterns by just using some simple statistical rules might miss important interactions. You really want to capture the correlations and the dependencies of the variables, which can be quite complicated, in a model. With GenSQL, we want to enable a large set of users to query their data and their model without having to know all the details,” adds lead author Mathieu Huot, a research scientist in the Department of Brain and Cognitive Sciences and member of the Probabilistic Computing Project.
They are joined on the paper by Matin Ghavami and Alexander Lew, MIT graduate students; Cameron Freer, a research scientist; Ulrich Schaechtle and Zane Shelby of Digital Garage; Martin Rinard, an MIT professor in the Department of Electrical Engineering and Computer Science and member of the Computer Science and Artificial Intelligence Laboratory (CSAIL); and Feras Saad ’15, MEng ’16, PhD ’22, an assistant professor at Carnegie Mellon University. The research was recently presented at the ACM Conference on Programming Language Design and Implementation.
Combining models and databases
SQL, which stands for structured query language, is a programming language for storing and manipulating information in a database. In SQL, people can ask questions about data using keywords, such as by summing, filtering, or grouping database records.
However, querying a model can provide deeper insights, since models can capture what data imply for an individual. For instance, a female developer who wonders if she is underpaid is likely more interested in what salary data mean for her individually than in trends from database records.
The researchers noticed that SQL didn’t provide an effective way to incorporate probabilistic AI models, but at the same time, approaches that use probabilistic models to make inferences didn’t support complex database queries.
They built GenSQL to fill this gap, enabling someone to query both a dataset and a probabilistic model using a straightforward yet powerful formal programming language.
A GenSQL user uploads their data and probabilistic model, which the system automatically integrates. Then, she can run queries on data that also get input from the probabilistic model running behind the scenes. This not only enables more complex queries but can also provide more accurate answers.
For instance, a query in GenSQL might be something like, “How likely is it that a developer from Seattle knows the programming language Rust?” Just looking at a correlation between columns in a database might miss subtle dependencies. Incorporating a probabilistic model can capture more complex interactions.
Plus, the probabilistic models GenSQL utilizes are auditable, so people can see which data the model uses for decision-making. In addition, these models provide measures of calibrated uncertainty along with each answer.
For instance, with this calibrated uncertainty, if one queries the model for predicted outcomes of different cancer treatments for a patient from a minority group that is underrepresented in the dataset, GenSQL would tell the user that it is uncertain, and how uncertain it is, rather than overconfidently advocating for the wrong treatment.
Faster and more accurate results
To evaluate GenSQL, the researchers compared their system to popular baseline methods that use neural networks. GenSQL was between 1.7 and 6.8 times faster than these approaches, executing most queries in a few milliseconds while providing more accurate results.
They also applied GenSQL in two case studies: one in which the system identified mislabeled clinical trial data and the other in which it generated accurate synthetic data that captured complex relationships in genomics.
Next, the researchers want to apply GenSQL more broadly to conduct largescale modeling of human populations. With GenSQL, they can generate synthetic data to draw inferences about things like health and salary while controlling what information is used in the analysis.
They also want to make GenSQL easier to use and more powerful by adding new optimizations and automation to the system. In the long run, the researchers want to enable users to make natural language queries in GenSQL. Their goal is to eventually develop a ChatGPT-like AI expert one could talk to about any database, which grounds its answers using GenSQL queries.
This research is funded, in part, by the Defense Advanced Research Projects Agency (DARPA), Google, and the Siegel Family Foundation.
Summer 2024 reading from MITMIT News rounds up recent titles from Institute faculty and staff.MIT faculty and staff authors have published a plethora of books, chapters, and other literary contributions in the past year. The following titles represent some of their works published in the past 12 months. In addition to links for each book from its publisher, the MIT Libraries has compiled a helpful list of the titles held in its collections.
Looking for more literary works from the MIT community? Enjoy our book lists from 2023, 2022, and 2021.
Happy reading!
Novel, memoir, and poetry
“Seizing Control: Managing Epilepsy and Others’ Reactions to It — A Memoir” (Haley’s, 2023)
By Laura Beretsky, grant writer in the MIT Introduction to Technology, Engineering, and Science (MITES) program
Beretsky’s memoir, “Seizing Control,” details her journey with epilepsy, discrimination, and a major surgical procedure to reduce her seizures. After two surgical interventions, she has been seizure-free for eight years, though she notes she will always live with epilepsy.
“Sky. Pond. Mouth.” (Yas Press, 2024)
By Kevin McLellan, staff member in MIT’s Program in Art, Culture, and Technology
In this book of poetry, physical and emotional qualities free-range between the animate and inanimate as though the world is written with dotted lines. With chiseled line breaks, intriguing meta-poetic levels, and punctuation like seed pods, McLellan’s poems, if we look twice, might flourish outside the book’s margin, past the grow light of the screen, even (especially) other borderlines we haven’t begun to imagine.
Science and engineering
“The Visual Elements: Handbooks for Communicating Science and Engineering” (University of Chicago Press, 2023 and 2024)
By Felice Frankel, research scientist in chemical engineering
Each of the two books in the “Visual Elements” series focuses on a different aspect of scientific visual communication: photography on one hand and design on the other. Their unifying goal is to provide guidance for scientists and engineers who must communicate their work with the public, for grant applications, journal submissions, conference or poster presentations, and funding agencies. The books show researchers the importance of presenting their work in clear, concise, and appealing ways that also maintain scientific integrity.
“A Book of Waves” (Duke University Press, 2023)
By Stefan Helmreich, professor of anthropology
In this book, Helmreich examines ocean waves as forms of media that carry ecological, geopolitical, and climatological news about our planet. Drawing on ethnographic work with oceanographers and coastal engineers in the Netherlands, the United States, Australia, Japan, and Bangladesh, he details how scientists at sea and in the lab apprehend waves’ materiality through abstractions, seeking to capture in technical language these avatars of nature at once periodic and irreversible, wild and pacific, ephemeral and eternal.
“An Introduction to System Safety Engineering” (MIT Press, 2023)
By Nancy G. Leveson, professor of aeronautics and astronautics
Preventing accidents and losses in complex systems requires a holistic perspective that can accommodate unprecedented types of technology and design. Leveson’s book covers the history of safety engineering; explores risk, ethics, legal frameworks, and policy implications; and explains why accidents happen and how to mitigate risks in modern, software-intensive systems. It includes accounts of well-known accidents like the Challenger and Columbia space shuttle disasters, Deepwater Horizon oil spill, and Chernobyl and Fukushima nuclear accidents, examining their causes and how to prevent similar incidents in the future.
“Solvable: How We Healed the Earth, and How We Can Do It Again” (University of Chicago Press, 2024)
By Susan Solomon, the Lee and Geraldine Martin Professor of Environmental Studies and Chemistry
We solved planet-threatening problems before, Solomon argues, and we can do it again. She knows firsthand what those solutions entail, as she gained international fame as the leader of a 1986 expedition to Antarctica, making discoveries that were key to healing the damaged ozone layer. She saw a path from scientific and public awareness to political engagement, international agreement, industry involvement, and effective action. Solomon connects this triumph to the stories of other past environmental victories — against ozone depletion, smog, pesticides, and lead — to extract the essential elements of what makes change possible.
Culture, humanities, and social sciences
“Political Rumors: Why We Accept Misinformation and How to Fight It” (Princeton University Press, 2023)
By Adam Berinsky, professor of political science
Political rumors pollute the political landscape. But if misinformation crowds out the truth, how can democracy survive? Berinsky examines why political rumors exist and persist despite their unsubstantiated and refuted claims, who is most likely to believe them, and how to combat them. He shows that a tendency toward conspiratorial thinking and vehement partisan attachment fuel belief in rumors. Moreover, in fighting misinformation, it is as important to target the undecided and the uncertain as it is the true believers.
“Laws of the Land: Fengshui and the State in Qing Dynasty China,” (Princeton University Press, 2023)
By Tristan Brown, assistant professor of history
In “Laws of the Land,” Brown tells the story of the important roles — especially legal ones — played by fengshui in Chinese society during China’s last imperial dynasty, the Manchu Qing (1644–1912). Employing archives from Mainland China and Taiwan that have only recently become available, this is the first book to document fengshui’s invocations in Chinese law during the Qing dynasty.
“Trouble with Gender: Sex Facts, Gender Fictions” (Polity, 2024)
By Alex Byrne, professor of philosophy
MIT philosopher Alex Byrne knows that within his field, he’s very much in the minority when it comes to his views on sex and gender. In “Trouble with Gender,” Byrne suggests that some ideas regarding sex and gender have not been properly examined by philosophers, and he argues for a reasoned and civil conversation on the topic.
“Life at the Center: Haitians and Corporate Catholicism in Boston” (University of California Press, 2024)
By Erica Caple James, professor of medical anthropology and urban studies
In “Life at the Center,” James traces how faith-based and secular institutions in Boston have helped Haitian refugees and immigrants attain economic independence, health, security, and citizenship in the United States. The culmination of more than a decade of advocacy and research on behalf of the Haitians in Boston, this groundbreaking work exposes how Catholic corporations have strengthened — but also eroded — Haitians’ civic power.
“Portable Postsocialisms: New Cuban Mediascapes after the End of History” (University of Texas Press, 2024)
By Paloma Duong, associate professor of media studies/writing
Why does Cuban socialism endure as an object of international political desire, while images of capitalist markets consume Cuba’s national imagination? “Portable Postsocialisms” calls on a vast multimedia archive to offer a groundbreaking cultural interpretation of Cuban postsocialism. Duong examines songs, artworks, advertisements, memes, literature, jokes, and networks that refuse exceptionalist and exoticizing visions of Cuba.
“They All Made Peace — What Is Peace?” (University of Chicago Press, 2023)
Chapter by Lerna Ekmekcioglu, professor of history and director of the Program in Women’s and Gender Studies
In her chapter, Ekmekcioglu contends that the Treaty of Lausanne, which followed the first world war, is an often-overlooked event of great historical significance for Armenians. The treaty became the “birth certificate” of modern Turkey, but there was no redress for Armenians. The chapter uses new research to reconstruct the dynamics of the treaty negotiations, illuminating both Armenians’ struggles as well as the international community’s struggles to deliver consistent support for multiethnic, multireligious states.
“We’ve Got You Covered: Rebooting American Health Care” (Portfolio, 2023)
By Amy Finkelstein, professor of economics, and Liran Einav
Few of us need convincing that the American health insurance system needs reform. But many existing proposals miss the point, focusing on expanding one relatively successful piece of the system or building in piecemeal additions. As Finkelstein and Einav point out, our health care system was never deliberately designed, but rather pieced together to deal with issues as they became politically relevant. The result is a sprawling, arbitrary, and inadequate mess that has left 30 million Americans without formal insurance. It’s time, the authors argue, to tear it all down and rebuild, sensibly and deliberately.
“At the Pivot of East and West: Ethnographic, Literary and Filmic Arts” (Duke University Press, 2023)
By Michael M.J. Fischer, professor of anthropology and of science and technology studies
In his latest book, Fischer examines documentary filmmaking and literature from Southeast Asia and Singapore for their para-ethnographic insights into politics, culture, and aesthetics. Continuing his project of applying anthropological thinking to the creative arts, Fischer exemplifies how art and fiction trace the ways in which taken-for-granted common sense changes over time speak to the transnational present and track signals of the future before they surface in public awareness.
“Lines Drawn across the Globe” (McGill-Queen's University Press, 2023)
By Mary Fuller, professor of literature and chair of the faculty
Around 1600, English geographer and cleric Richard Hakluyt published a 2,000-page collection of travel narratives, royal letters, ships’ logs, maps, and more from over 200 voyages. In "Lines Drawn across the Globe," Fuller traces the history of the book’s compilation and gives order and meaning to its diverse contents. From Sierra Leone to Iceland, from Spanish narratives of New Mexico to French accounts of the Saint Lawrence and Portuguese accounts of China, Hakluyt’s shaping of the book provides a conceptual map of the world’s regions and of England’s real and imagined relations to them.
“The Rise and Fall of the EAST: How Exams, Autocracy, Stability, and Technology Brought China Success, and Why They Might Lead to Its Decline” (Yale University Press, 2023)
By Yasheng Huang, the Epoch Foundation Professor of International Management and professor of global economics and management
According to Huang, the world is seeing a repeat of Chinese history during which restrictions on economic and political freedom created economic stagnation. The bottom line: “Without academic collaboration, without business collaboration, without technological collaborations, the pace of Chinese technological progress is going to slow down dramatically.”
“The Long First Millennium: Affluence, Architecture, and Its Dark Matter Economy” (Routledge, 2023)
By Mark Jarzombek, professor of the history and theory of architecture
Jarzombek’s book argues that long-distance trade in luxury items — such as diamonds, gold, cinnamon, scented woods, ivory, and pearls, all of which require little overhead in their acquisition and were relatively easy to transport — played a foundational role in the creation of what we would call “global trade” in the first millennium CE. The book coins the term “dark matter economy” to better describe this complex — though mostly invisible — relationship to normative realities. “The Long Millennium” will appeal to students, scholars, and anyone interested in the effect of trade on medieval society.
“World Literature in the Soviet Union” (Academic Studies Press, 2023)
Chapter by Maria Khotimsky, senior lecturer in Russian
Khotimsky’s chapter, “The Treasure Trove of World Literature: Shaping the Concept of World Literature in Post-Revolutionary Russia,” examines Vsemirnaia Literatura (World Literature), an early Soviet publishing house founded in 1919 in Petersburg that advanced an innovative canon of world literature beyond the European tradition. It analyzes the publishing house’s views on translation, focusing on book prefaces that reveal a search for a new evaluative system, adaptation to changing socio-cultural norms and reassessing the roles of readers, critics, and the very endeavor of translation.
“Dare to Invent the Future: Knowledge in the Service of and Through Problem-Solving” (MIT Press, 2023)
By Clapperton Chakanetsa Mavhunga, professor of science, technology, and society
In this provocative book — the first in a trilogy — Chakanetsa Mavhunga argues that our critical thinkers must become actual thinker-doers. Taking its title from one of Thomas Sankara’s most inspirational speeches, “Dare to Invent the Future” looks for moments in Africa’s story where precedents of critical thought and knowledge in service of problem-solving are evident to inspire readers to dare to invent such a knowledge system.
“Death, Dominance, and State-Building: The US in Iraq and the Future of American Military Intervention” (Oxford University Press, 2024)
By Roger Petersen, the Arthur and Ruth Sloan Professor of Political Science
“Death, Dominance, and State-Building” provides the first comprehensive analytic history of post-invasion Iraq. Although the war is almost universally derided as one of the biggest foreign policy blunders of the post-Cold War era, Petersen argues that the course and conduct of the conflict is poorly understood. The book applies an accessible framework to a variety of case studies across time and region. It concludes by drawing lessons relevant to future American military interventions.
Technology, systems, and society
“Code Work: Hacking Across the U.S./México Techno-Borderlands” (Princeton University Press, 2023)
By Héctor Beltrán, assistant professor of anthropology
In this book, Beltrán examines Mexican and Latinx coders’ personal strategies of self-making as they navigate a transnational economy of tech work. Beltrán shows how these hackers apply concepts from the coding world to their lived experiences, deploying batches, loose coupling, iterative processing (looping), hacking, prototyping, and full-stack development in their daily social interactions — at home, in the workplace, on the dating scene, and in their understanding of the economy, culture, and geopolitics.
“Unmasking AI: My Mission to Protect What is Human in a World of Machines” (Penguin Random House, 2023)
By Joy Buolamwini SM ’17, PhD ’22, member of the Media Lab Director’s Circle
To many it may seem like recent developments in artificial intelligence emerged out of nowhere to pose unprecedented threats to humankind. But to Buolamwini, this moment has been a long time in the making. “Unmasking AI” is the remarkable story of how Buolamwini uncovered what she calls “the coded gaze” — evidence of encoded discrimination and exclusion in tech products. She shows how racism, sexism, colorism, and ableism can overlap and render broad swaths of humanity “excoded” and therefore vulnerable in a world rapidly adopting AI tools.
“Counting Feminicide: Data Feminism in Action” (MIT Press, 2024)
By Catherine D’Ignazio, associate professor of urban science and planning
“Counting Feminicide” brings to the fore the work of data activists across the Americas who are documenting feminicide, and challenging the reigning logic of data science by centering care, memory, and justice in their work. D’Ignazio describes the creative, intellectual, and emotional labor of feminicide data activists who are at the forefront of a data ethics that rigorously and consistently takes power and people into account.
“Rethinking Cyber Warfare: The International Relations of Digital Disruption” (Oxford University Press, 2024)
By R. David Edelman, research fellow at the MIT Center for International Studies
Fifteen years into the era of “cyber warfare,” are we any closer to understanding the role a major cyberattack would play in international relations — or to preventing one? Uniquely spanning disciplines and enriched by the insights of a leading practitioner, Edelman provides a fresh understanding of the role that digital disruption plays in contemporary international security.
“Model Thinking for Everyday Life: How to Make Smarter Decisions” (INFORMS, 2023)
By Richard Larson, professor post-tenure in the Institute for Data, Systems, and Society
Decisions are a part of everyday life, whether simple or complex. It’s all too easy to jump to Google for the answers, but where does that take us? We’re losing the ability to think critically and decide for ourselves. In this book, Larson asks readers to undertake a major mind shift in our everyday thought processes. Model thinking develops our critical thinking skills, using a framework of conceptual and mathematical tools to help guide us to full comprehension, and better decisions.
“Future[tectonics]: Exploring the intersection between technology, architecture and urbanism” (Parametric Architecture, 2024)
Chapter by Jacob Lehrer, project coordinator in the Department of Mathematics
In his chapter, “Garbage In, Garbage Out: How Language Models Can Reinforce Biases,” Lehrer discusses how inherent bias is baked into large data sets, like those used to train massive AI algorithms, and how society will need to reconcile with the inherent biases built into systems of power. He also attempts to reconcile with it himself, delving into the mathematics behind these systems.
“Music and Mind: Harnessing the Arts for Health and Wellness” (Penguin Random House, 2024)
Chapter by Tod Machover, the Muriel R. Cooper Professor of Music and Media; Rébecca Kleinberger SM ’14, PhD ’20; and Alexandra Rieger SM ’18, doctoral candidate in media arts and sciences
In their chapter, “Composing the Future of Health,” the co-authors discuss their approach to combining scientific research, technology innovation, and new composing strategies to create evidence-based, emotionally potent music that can delight and heal.
“The Heart and the Chip: Our Bright Future with Robots” (W. W. Norton and Company, 2024)
By Daniela Rus, the Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science and director of the Computer Science and Artificial Intelligence Laboratory; and Gregory Mone
In “The Heart and the Chip,” Rus and Mone provide an overview of the interconnected fields of robotics, artificial intelligence, and machine learning, and reframe the way we think about intelligent machines while weighing the moral and ethical consequences of their role in society. Robots aren’t going to steal our jobs, they argue; they’re going to make us more capable, productive, and precise.
Education, business, finance, and social impact
“Disciplined Entrepreneurship Startup Tactics: 15 Tactics to Turn Your Business Plan Into a Business” (Wiley, 2024)
By Paul Cheek, executive director and entrepreneur in residence at the Martin Trust Center for MIT Entrepreneurship and senior lecturer in the MIT Sloan School of Management, with foreword by Bill Aulet, professor of the practice of entrepreneurship at MIT Sloan and managing director of the Martin Trust Center
Cheek provides a hands-on, practical roadmap to get from great idea to successful company with his actionable field guide to transforming your one great idea into a functional, funded, and staffed startup. Readers will find ground-level, down-and-dirty entrepreneurial tactics — like how to conduct advanced primary market research, market and sell to your first customers, and take a scrappy approach to building your first products — that keep young firms growing. These tactics maximize impact with limited resources.
“Organic Social Media: How to Build Flourishing Online Communities” (KoganPage, 2023)
By Jenny Li Fowler, director of social media strategy in the Institute Office of Communications
In “Organic Social Media,” Fowler outlines the important steps that social media managers need to take to enhance an organization's broader growth objectives. Fowler breaks down the key questions to help readers determine the best platforms to invest in, how they can streamline approval processes, and other essential strategic steps to create an organic following on social platforms.
“From Intention to Impact: A Practical Guide to Diversity, Equity, and Inclusion” (MIT Press, 2024)
By Malia Lazu, lecturer in the MIT Sloan School of Management
In her new book, Lazu draws on her background as a community organizer, her corporate career as a bank president, and now her experience as a leading consultant to explain what has been holding organizations back and what they can do to become more inclusive and equitable. “From Intention to Impact” goes beyond “feel good” PR-centric actions to showcase the real work that must be done to create true and lasting change.
“The AFIRE Guide to U.S. Real Estate Investing” (Afire and McGraw Hill, 2024)
Chapter by Jacques Gordon, lecturer in the MIT Center for Real Estate
In his chapter, “The Broker and the Investment Advisor: A wide range of options,” Gordon discusses important financial topics including information for lenders and borrowers, joint ventures, loans and debt, comingled funds, bankruptcy, and Islamic finance.
“The Geek Way: The Radical Mindset That Drives Extraordinary Results” (Hachette Book Group, 2023)
By Andrew McAfee, principal research scientist and co-director of the MIT Initiative on the Digital Economy
The geek way of management delivers excellent performance while offering employees a work environment that features high levels of autonomy and empowerment. In what Eric Schmidt calls a “handbook for disruptors,” “The Geek Way” reveals a new way to get big things done. It will change the way readers think about work, teams, projects, and culture, and give them the insight and tools to harness our human superpowers of learning and cooperation.
“Iterate: The Secret to Innovation in Schools” (Teaching Systems Lab, 2023)
By Justin Reich, associate professor in comparative media studies/writing
In “Iterate,” Reich delivers an insightful bridge between contemporary educational research and classroom teaching, showing readers how to leverage the cycle of experiment and experience to create a compelling and engaging learning environment. Readers learn how to employ a process of continuous improvement and tinkering to develop exciting new programs, activities, processes, and designs.
“red helicopter — a parable for our times: lead change with kindness (plus a little math)” (HarperCollins, 2024)
By James Rhee, senior lecturer in the MIT Sloan School of Management
Is it possible to be successful and kind? To lead a company or organization with precision and compassion? To honor who we are in all areas of our lives? While eloquently sharing a story of personal and professional success, Rhee presents a comforting yet bold solution to the dissatisfaction and worry we all feel in a chaotic and sometimes terrifying world.
“Routes to Reform: Education Politics in Latin America” (Oxford University Press, 2024)
By Ben Ross Schneider, the Ford International Professor of Political Science and faculty director of the MIT-Chile Program and MISTI Chile
In “Routes to Reform,” Ben Ross Schneider examines education policy throughout Latin America to show that reforms to improve learning — especially making teacher careers more meritocratic and less political — are possible. He demonstrates that contrary to much established theory, reform outcomes in Latin America depended less on institutions and broad coalitions, and more on micro-level factors like civil society organizations, teacher unions, policy networks, and technocrats.
“Wiring the Winning Organization: Liberating Our Collective Greatness through Slowification, Simplification, and Amplification” (IT Revolution, 2023)
By Steven J. Spear, senior lecturer in system dynamics at the MIT Sloan School of Management, and Gene Kim
Organizations succeed when they design their processes, routines, and procedures to encourage employees to problem-solve and contribute to a common purpose. DevOps, Lean, and Agile got us part of the way. Now with “Wiring the Winning Organization,” Spear and Kim introduce a new theory of organizational management: Organizations win by using three mechanisms to slowify, simplify, and amplify, which systematically moves problem-solving from high-risk danger zones to low-risk winning zones.
“Oxford Research Encyclopedia of Economics and Finance” (Oxford University Press, 2024)
Chapter by Annie Thompson, lecturer in the MIT Center for Real Estate; Walter Torous, senior lecturer at the MIT Center for Real Estate; and William Torous
In their chapter, “What Causes Residential Mortgage Defaults?” the authors assess the voluminous research investigating why households default on their residential mortgages. A particular focus is oriented towards critically evaluating the recent application of causal statistical inference to residential defaults on mortgages.
“Data Is Everybody’s Business: The Fundamentals of Data Monetization” (MIT Press, 2023)
By Barbara H. Wixom, principal research scientist at the MIT Sloan Center for Information Systems Research (MIT CISR); Leslie Owens, senior lecturer at the MIT Sloan School of Management and former executive director of MIT CISR; and Cynthia M. Beath
In “Data Is Everybody’s Business,” the authors offer a clear and engaging way for people across the entire organization to understand data monetization and make it happen. The authors identify three viable ways to convert data into money — improving work with data, wrapping products with data, and selling information offerings — and explain when to pursue each and how to succeed.
Arts, architecture, planning, and design
“The Routledge Handbook of Museums, Heritage, and Death” (Routledge, 2023)
Chapter by Laura Anderson Barbata, lecturer in MIT’s Program in Art, Culture, and Technology
This book provides an examination of death, dying, and human remains in museums and heritage sites around the world. In her chapter, “Julia Pastrana’s Long Journey Home,” Barbata describes the case of Julia Pastrana (1834-1860), an indigenous Mexican opera singer who suffered from hypertrichosis terminalis and hyperplasia gingival. Due to her appearance, Pastrana was exploited and exhibited for over 150 years, during her lifetime and after her early death in an embalmed state. Barbata sheds light on the ways in which the systems that justified Pastrana’s exploitation continue to operate today.
“Emergency INDEX: An Annual Document of Performance Practice, vol. 10” (Ugly Duckling Press, 2023)
Chapter by Gearoid Dolan, staff member in MIT’s Program in Art, Culture, and Technology
This “bible of performance art activity” documents performance projects from around the world. Dolan’s chapter describes “Protest ReEmbodied,” a performance that took place online during Covid-19 lockdown. The performance was a live version of the ongoing “Protest ReEmbodied” project, an app that individuals can download and run on their computer to be able to perform on camera, inserted into protest footage.
“Land Air Sea: Architecture and Environment in the Early Modern Era” (Brill, 2023)
Chapter by Caroline Murphy, the Clarence H. Blackall Career Development Assistant Professor in the Department of Architecture
“Land Air Sea” positions the long Renaissance and 18th century as being vital for understanding how many of the concerns present in contemporary debates on climate change and sustainability originated in earlier centuries. Murphy’s chapter examines how Girolamo di Pace da Prato, a state engineer in the Duchy of Florence, understood and sought to mitigate the problems of alluvial flooding in the mid-sixteenth century, an era of exceptional aquatic and environmental volatility.
Miscellaneous
“Made Here: Recipes and Reflections From NYC’s Asian Communities” (Send Chinatown Love, 2023)
Chapter by Robin Zhang, postdoc in mathematics, and Diana Le
In their chapter, “Flushing: The Melting Pot’s Melting Pot,” the authors explore how Flushing, New York — whose Chinatown is the largest and fastest growing in the world — earned the title of the “melting pot’s melting pot” through its cultural history. Readers will walk down its streets past its snack stalls, fabric stores, language schools, hair salons, churches, and shrines, and you will hear English interspersed with Korean, several dialects of Chinese, Hindi, Bengali, Urdu, and hundreds of other fibers that make up Flushing’s complex ethnolinguistic fabric.
Scientists observe record-setting electron mobility in a new crystal filmThe newly synthesized material could be the basis for wearable thermoelectric and spintronic devices.A material with a high electron mobility is like a highway without traffic. Any electrons that flow into the material experience a commuter’s dream, breezing through without any obstacles or congestion to slow or scatter them off their path.
The higher a material’s electron mobility, the more efficient its electrical conductivity, and the less energy is lost or wasted as electrons zip through. Advanced materials that exhibit high electron mobility will be essential for more efficient and sustainable electronic devices that can do more work with less power.
Now, physicists at MIT, the Army Research Lab, and elsewhere have achieved a record-setting level of electron mobility in a thin film of ternary tetradymite — a class of mineral that is naturally found in deep hydrothermal deposits of gold and quartz.
For this study, the scientists grew pure, ultrathin films of the material, in a way that minimized defects in its crystalline structure. They found that this nearly perfect film — much thinner than a human hair — exhibits the highest electron mobility in its class.
The team was able to estimate the material’s electron mobility by detecting quantum oscillations when electric current passes through. These oscillations are a signature of the quantum mechanical behavior of electrons in a material. The researchers detected a particular rhythm of oscillations that is characteristic of high electron mobility — higher than any ternary thin films of this class to date.
“Before, what people had achieved in terms of electron mobility in these systems was like traffic on a road under construction — you’re backed up, you can’t drive, it’s dusty, and it’s a mess,” says Jagadeesh Moodera, a senior research scientist in MIT’s Department of Physics. “In this newly optimized material, it’s like driving on the Mass Pike with no traffic.”
The team’s results, which appear today in the journal Materials Today Physics, point to ternary tetradymite thin films as a promising material for future electronics, such as wearable thermoelectric devices that efficiently convert waste heat into electricity. (Tetradymites are the active materials that cause the cooling effect in commercial thermoelectric coolers.) The material could also be the basis for spintronic devices, which process information using an electron’s spin, using far less power than conventional silicon-based devices.
The study also uses quantum oscillations as a highly effective tool for measuring a material’s electronic performance.
“We are using this oscillation as a rapid test kit,” says study author Hang Chi, a former research scientist at MIT who is now at the University of Ottawa. “By studying this delicate quantum dance of electrons, scientists can start to understand and identify new materials for the next generation of technologies that will power our world.”
Chi and Moodera’s co-authors include Patrick Taylor, formerly of MIT Lincoln Laboratory, along with Owen Vail and Harry Hier of the Army Research Lab, and Brandi Wooten and Joseph Heremans of Ohio State University.
Beam down
The name “tetradymite” derives from the Greek “tetra” for “four,” and “dymite,” meaning “twin.” Both terms describe the mineral’s crystal structure, which consists of rhombohedral crystals that are “twinned” in groups of four — i.e. they have identical crystal structures that share a side.
Tetradymites comprise combinations of bismuth, antimony tellurium, sulfur, and selenium. In the 1950s, scientists found that tetradymites exhibit semiconducting properties that could be ideal for thermoelectric applications: The mineral in its bulk crystal form was able to passively convert heat into electricity.
Then, in the 1990s, the late Institute Professor Mildred Dresselhaus proposed that the mineral’s thermoelectric properties might be significantly enhanced, not in its bulk form but within its microscopic, nanometer-scale surface, where the interactions of electrons is more pronounced. (Heremans happened to work in Dresselhaus’ group at the time.)
“It became clear that when you look at this material long enough and close enough, new things will happen,” Chi says. “This material was identified as a topological insulator, where scientists could see very interesting phenomena on their surface. But to keep uncovering new things, we have to master the material growth.”
To grow thin films of pure crystal, the researchers employed molecular beam epitaxy — a method by which a beam of molecules is fired at a substrate, typically in a vacuum, and with precisely controlled temperatures. When the molecules deposit on the substrate, they condense and build up slowly, one atomic layer at a time. By controlling the timing and type of molecules deposited, scientists can grow ultrathin crystal films in exact configurations, with few if any defects.
“Normally, bismuth and tellurium can interchange their position, which creates defects in the crystal,” co-author Taylor explains. “The system we used to grow these films came down with me from MIT Lincoln Laboratory, where we use high purity materials to minimize impurities to undetectable limits. It is the perfect tool to explore this research.”
Free flow
The team grew thin films of ternary tetradymite, each about 100 nanometers thin. They then tested the film’s electronic properties by looking for Shubnikov-de Haas quantum oscillations — a phenomenon that was discovered by physicists Lev Shubnikov and Wander de Haas, who found that a material’s electrical conductivity can oscillate when exposed to a strong magnetic field at low temperatures. This effect occurs because the material’s electrons fill up specific energy levels that shift as the magnetic field changes.
Such quantum oscillations could serve as a signature of a material’s electronic structure, and the ways in which electrons behave and interact. Most notably for the MIT team, the oscillations could determine a material’s electron mobility: If oscillations exist, it must mean that the material’s electrical resistance is able to change, and by inference, electrons can be mobile, and made to easily flow.
The team looked for signs of quantum oscillations in their new films, by first exposing them to ultracold temperatures and a strong magnetic field, then running an electric current through the film and measuring the voltage along its path, as they tuned the magnetic field up and down.
“It turns out, to our great joy and excitement, that the material’s electrical resistance oscillates,” Chi says. “Immediately, that tells you that this has very high electron mobility.”
Specifically, the team estimates that the ternary tetradymite thin film exhibits an electron mobility of 10,000 cm2/V-s — the highest mobility of any ternary tetradymite film yet measured. The team suspects that the film’s record mobility has something to do with its low defects and impurities, which they were able to minimize with their precise growth strategies. The fewer a material’s defects, the fewer obstacles an electron encounters, and the more freely it can flow.
“This is showing it’s possible to go a giant step further, when properly controlling these complex systems,” Moodera says. “This tells us we’re in the right direction, and we have the right system to proceed further, to keep perfecting this material down to even much thinner films and proximity coupling for use in future spintronics and wearable thermoelectric devices.”
This research was supported in part by the Army Research Office, National Science Foundation, Office of Naval Research, Canada Research Chairs Program and Natural Sciences and Engineering Research Council of Canada.
Scientists use computational modeling to guide a difficult chemical synthesisUsing this new approach, researchers could develop drug compounds with unique pharmaceutical properties.Researchers from MIT and the University of Michigan have discovered a new way to drive chemical reactions that could generate a wide variety of compounds with desirable pharmaceutical properties.
These compounds, known as azetidines, are characterized by four-membered rings that include nitrogen. Azetidines have traditionally been much more difficult to synthesize than five-membered nitrogen-containing rings, which are found in many FDA-approved drugs.
The reaction that the researchers used to create azetidines is driven by a photocatalyst that excites the molecules from their ground energy state. Using computational models that they developed, the researchers were able to predict compounds that can react with each other to form azetidines using this kind of catalysis.
“Going forward, rather than using a trial-and-error process, people can prescreen compounds and know beforehand which substrates will work and which ones won't,” says Heather Kulik, an associate professor of chemistry and chemical engineering at MIT.
Kulik and Corinna Schindler, a professor of chemistry at the University of Michigan, are the senior authors of the study, which appears today in Science. Emily Wearing, recently a graduate student at the University of Michigan, is the lead author of the paper. Other authors include University of Michigan postdoc Yu-Cheng Yeh, MIT graduate student Gianmarco Terrones, University of Michigan graduate student Seren Parikh, and MIT postdoc Ilia Kevlishvili.
Light-driven synthesis
Many naturally occurring molecules, including vitamins, nucleic acids, enzymes and hormones, contain five-membered nitrogen-containing rings, also known as nitrogen heterocycles. These rings are also found in more than half of all FDA-approved small-molecule drugs, including many antibiotics and cancer drugs.
Four-membered nitrogen heterocycles, which are rarely found in nature, also hold potential as drug compounds. However, only a handful of existing drugs, including penicillin, contain four-membered heterocycles, in part because these four-membered rings are much more difficult to synthesize than five-membered heterocycles.
In recent years, Schindler’s lab has been working on synthesizing azetidines using light to drive a reaction that combines two precursors, an alkene and an oxime. These reactions require a photocatalyst, which absorbs light and passes the energy to the reactants, making it possible for them to react with each other.
“The catalyst can transfer that energy to another molecule, which moves the molecules into excited states and makes them more reactive. This is a tool that people are starting to use to make it possible to make certain reactions occur that wouldn't normally occur,” Kulik says.
Schindler’s lab found that while this reaction sometimes worked well, other times it did not, depending on which reactants were used. They enlisted Kulik, an expert in developing computational approaches to modeling chemical reactions, to help them figure out how to predict when these reactions will occur.
The two labs hypothesized that whether a particular alkene and oxime will react together in a photocatalyzed reaction depends on a property known as the frontier orbital energy match. Electrons that surround the nucleus of an atom exist in orbitals, and quantum mechanics can be used to predict the shape and energies of these orbitals. For chemical reactions, the most important electrons are those in the outermost, highest energy (“frontier”) orbitals, which are available to react with other molecules.
Kulik and her students used density functional theory, which uses the Schrödinger equation to predict where electrons could be and how much energy they have, to calculate the orbital energy of these outermost electrons.
These energy levels are also affected by other groups of atoms attached to the molecule, which can change the properties of the electrons in the outermost orbitals.
Once those energy levels are calculated, the researchers can identify reactants that have similar energy levels when the photocatalyst boosts them into an excited state. When the excited states of an alkene and an oxime are closely matched, less energy is required to boost the reaction to its transition state — the point at which the reaction has enough energy to go forward to form products.
Accurate predictions
After calculating the frontier orbital energies for 16 different alkenes and nine oximes, the researchers used their computational model to predict whether 18 different alkene-oxime pairs would react together to form an azetidine. With the calculations in hand, these predictions can be made in a matter of seconds.
The researchers also modeled a factor that influences the overall yield of the reaction: a measure of how available the carbon atoms in the oxime are to participate in chemical reactions.
The model’s predictions suggested that some of these 18 reactions won’t occur or won’t give a high enough yield. However, the study also showed that a significant number of reactions are correctly predicted to work.
“Based on our model, there's a much wider range of substrates for this azetidine synthesis than people thought before. People didn't really think that all of this was accessible,” Kulik says.
Of the 27 combinations that they studied computationally, the researchers tested 18 reactions experimentally, and they found that most of their predictions were accurate. Among the compounds they synthesized were derivatives of two drug compounds that are currently FDA-approved: amoxapine, an antidepressant, and indomethacin, a pain reliever used to treat arthritis.
This computational approach could help pharmaceutical companies predict molecules that will react together to form potentially useful compounds, before spending a lot of money to develop a synthesis that might not work, Kulik says. She and Schindler are continuing to work together on other kinds of novel syntheses, including the formation of compounds with three-membered rings.
“Using photocatalysts to excite substrates is a very active and hot area of development, because people have exhausted what you can do on the ground state or with radical chemistry,” Kulik says. “I think this approach is going to have a lot more applications to make molecules that are normally thought of as really challenging to make.”