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New algorithm unlocks high-resolution insights for computer vision

Mon, 03/18/2024 - 3:10pm

Imagine yourself glancing at a busy street for a few moments, then trying to sketch the scene you saw from memory. Most people could draw the rough positions of the major objects like cars, people, and crosswalks, but almost no one can draw every detail with pixel-perfect accuracy. The same is true for most modern computer vision algorithms: They are fantastic at capturing high-level details of a scene, but they lose fine-grained details as they process information.

Now, MIT researchers have created a system called “FeatUp” that lets algorithms capture all of the high- and low-level details of a scene at the same time — almost like Lasik eye surgery for computer vision.

When computers learn to “see” from looking at images and videos, they build up “ideas” of what's in a scene through something called “features.” To create these features, deep networks and visual foundation models break down images into a grid of tiny squares and process these squares as a group to determine what's going on in a photo. Each tiny square is usually made up of anywhere from 16 to 32 pixels, so the resolution of these algorithms is dramatically smaller than the images they work with. In trying to summarize and understand photos, algorithms lose a ton of pixel clarity. 

The FeatUp algorithm can stop this loss of information and boost the resolution of any deep network without compromising on speed or quality. This allows researchers to quickly and easily improve the resolution of any new or existing algorithm. For example, imagine trying to interpret the predictions of a lung cancer detection algorithm with the goal of localizing the tumor. Applying FeatUp before interpreting the algorithm using a method like class activation maps (CAM) can yield a dramatically more detailed (16-32x) view of where the tumor might be located according to the model. 

FeatUp not only helps practitioners understand their models, but also can improve a panoply of different tasks like object detection, semantic segmentation (assigning labels to pixels in an image with object labels), and depth estimation. It achieves this by providing more accurate, high-resolution features, which are crucial for building vision applications ranging from autonomous driving to medical imaging.

“The essence of all computer vision lies in these deep, intelligent features that emerge from the depths of deep learning architectures. The big challenge of modern algorithms is that they reduce large images to  very small grids of 'smart' features, gaining intelligent insights but losing the finer details,” says Mark Hamilton, an MIT PhD student in electrical engineering and computer science, MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) affiliate, and a co-lead author on a paper about the project. “FeatUp helps enable the best of both worlds: highly intelligent representations with the original image’s resolution. These high-resolution features significantly boost performance across a spectrum of computer vision tasks, from enhancing object detection and improving depth prediction to providing a deeper understanding of your network's decision-making process through high-resolution analysis.” 

Resolution renaissance 

As these large AI models become more and more prevalent, there’s an increasing need to explain what they’re doing, what they’re looking at, and what they’re thinking. 

But how exactly can FeatUp discover these fine-grained details? Curiously, the secret lies in wiggling and jiggling images. 

In particular, FeatUp applies minor adjustments (like moving the image a few pixels to the left or right) and watches how an algorithm responds to these slight movements of the image. This results in hundreds of deep-feature maps that are all slightly different, which can be combined into a single crisp, high-resolution, set of deep features. “We imagine that some high-resolution features exist, and that when we wiggle them and blur them, they will match all of the original, lower-resolution features from the wiggled images. Our goal is to learn how to refine the low-resolution features into high-resolution features using this 'game' that lets us know how well we are doing,” says Hamilton. This methodology is analogous to how algorithms can create a 3D model from multiple 2D images by ensuring that the predicted 3D object matches all of the 2D photos used to create it. In FeatUp’s case, they predict a high-resolution feature map that’s consistent with all of the low-resolution feature maps formed by jittering the original image.

The team notes that standard tools available in PyTorch were insufficient for their needs, and introduced a new type of deep network layer in their quest for a speedy and efficient solution. Their custom layer, a special joint bilateral upsampling operation, was over 100 times more efficient than a naive implementation in PyTorch. The team also showed this new layer could improve a wide variety of different algorithms including semantic segmentation and depth prediction. This layer improved the network’s ability to process and understand high-resolution details, giving any algorithm that used it a substantial performance boost. 

“Another application is something called small object retrieval, where our algorithm allows for precise localization of objects. For example, even in cluttered road scenes algorithms enriched with FeatUp can see tiny objects like traffic cones, reflectors, lights, and potholes where their low-resolution cousins fail. This demonstrates its capability to enhance coarse features into finely detailed signals,” says Stephanie Fu ’22, MNG ’23, a PhD student at the University of California at Berkeley and another co-lead author on the new FeatUp paper. “This is especially critical for time-sensitive tasks, like pinpointing a traffic sign on a cluttered expressway in a driverless car. This can not only improve the accuracy of such tasks by turning broad guesses into exact localizations, but might also make these systems more reliable, interpretable, and trustworthy.”

What next?

Regarding future aspirations, the team emphasizes FeatUp’s potential widespread adoption within the research community and beyond, akin to data augmentation practices. “The goal is to make this method a fundamental tool in deep learning, enriching models to perceive the world in greater detail without the computational inefficiency of traditional high-resolution processing,” says Fu.

“FeatUp represents a wonderful advance towards making visual representations really useful, by producing them at full image resolutions,” says Cornell University computer science professor Noah Snavely, who was not involved in the research. “Learned visual representations have become really good in the last few years, but they are almost always produced at very low resolution — you might put in a nice full-resolution photo, and get back a tiny, postage stamp-sized grid of features. That’s a problem if you want to use those features in applications that produce full-resolution outputs. FeatUp solves this problem in a creative way by combining classic ideas in super-resolution with modern learning approaches, leading to beautiful, high-resolution feature maps.”

“We hope this simple idea can have broad application. It provides high-resolution versions of image analytics that we’d thought before could only be low-resolution,” says senior author William T. Freeman, an MIT professor of electrical engineering and computer science professor and CSAIL member.

Lead authors Fu and Hamilton are accompanied by MIT PhD students Laura Brandt SM ’21 and Axel Feldmann SM ’21, as well as Zhoutong Zhang SM ’21, PhD ’22, all current or former affiliates of MIT CSAIL. Their research is supported, in part, by a National Science Foundation Graduate Research Fellowship, by the National Science Foundation and Office of the Director of National Intelligence, by the U.S. Air Force Research Laboratory, and by the U.S. Air Force Artificial Intelligence Accelerator. The group will present their work in May at the International Conference on Learning Representations.

Five MIT faculty members take on Cancer Grand Challenges

Mon, 03/18/2024 - 10:15am

Cancer Grand Challenges recently announced five winning teams for 2024, which included five researchers from MIT: Michael Birnbaum, Regina Barzilay, Brandon DeKosky, Seychelle Vos, and Ömer Yilmaz. Each team is made up of interdisciplinary cancer researchers from across the globe and will be awarded $25 million over five years. 

Birnbaum, an associate professor in the Department of Biological Engineering, leads Team MATCHMAKERS and is joined by co-investigators Barzilay, the School of Engineering Distinguished Professor for AI and Health in the Department of Electrical Engineering and Computer Science and the AI faculty lead at the MIT Abdul Latif Jameel Clinic for Machine Learning in Health; and DeKosky, Phillip and Susan Ragon Career Development Professor of Chemical Engineering. All three are also affiliates of the Koch Institute for Integrative Cancer Research At MIT.

Team MATCHMAKERS will take advantage of recent advances in artificial intelligence to develop tools for personalized immunotherapies for cancer patients. Cancer immunotherapies, which recruit the patient’s own immune system against the disease, have transformed treatment for some cancers, but not for all types and not for all patients. 

T cells are one target for immunotherapies because of their central role in the immune response. These immune cells use receptors on their surface to recognize protein fragments called antigens on cancer cells. Once T cells attach to cancer antigens, they mark them for destruction by the immune system. However, T cell receptors are exceptionally diverse within one person’s immune system and from person to person, making it difficult to predict how any one cancer patient will respond to an immunotherapy.  

Team MATCHMAKERS will collect data on T cell receptors and the different antigens they target and build computer models to predict antigen recognition by different T cell receptors. The team’s overarching goal is to develop tools for predicting T cell recognition with simple clinical lab tests and designing antigen-specific immunotherapies. “If successful, what we learn on our team could help transform prediction of T cell receptor recognition from something that is only possible in a few sophisticated laboratories in the world, for a few people at a time, into a routine process,” says Birnbaum. 

“The MATCHMAKERS project draws on MIT’s long tradition of developing cutting-edge artificial intelligence tools for the benefit of society,” comments Ryan Schoenfeld, CEO of The Mark Foundation for Cancer Research. “Their approach to optimizing immunotherapy for cancer and many other diseases is exemplary of the type of interdisciplinary research The Mark Foundation prioritizes supporting.” In addition to The Mark Foundation, the MATCHMAKERS team is funded by Cancer Research UK and the U.S. National Cancer Institute.

Vos, the Robert A. Swanson (1969) Career Development Professor of Life Sciences and HHMI Freeman Hrabowksi Scholar in the Department of Biology, will be a co-investigator on Team KOODAC. The KOODAC team will develop new treatments for solid tumors in children, using protein degradation strategies to target previously “undruggable” drivers of cancers. KOODAC is funded by Cancer Research UK, France's Institut National Du Cancer, and KiKa (Children Cancer Free Foundation) through Cancer Grand Challenges. 

As a co-investigator on team PROSPECT, Yilmaz, who is also a Koch Institute affiliate, will help address early-onset colorectal cancers, an emerging global problem among individuals younger than 50 years. The team seeks to elucidate pathways, risk factors, and molecules involved in the disease’s development. Team PROSPECT is supported by Cancer Research UK, the U.S. National Cancer Institute, the Bowelbabe Fund for Cancer Research UK, and France's Institut National Du Cancer through Cancer Grand Challenges.  

Unlocking the quantum future

Mon, 03/18/2024 - 9:55am

Quantum computing is the next frontier for faster and more powerful computing technologies. It has the potential to better optimize routes for shipping and delivery, speed up battery development for electric vehicles, and more accurately predict trends in financial markets. But to unlock the quantum future, scientists and engineers need to solve outstanding technical challenges while continuing to explore new applications.

One place where they’re working towards this future is the MIT Interdisciplinary Quantum Hackathon, or iQuHACK for short (pronounced “i-quack,” like a duck). Each year, a community of quhackers (quantum hackers) gathers at iQuHACK to work on quantum computing projects using real quantum computers and simulators. This year, the hackathon was held both in-person at MIT and online over three days in February.

Quhackers worked in teams to advance the capability of quantum computers and to investigate promising applications. Collectively, they tackled a wide range of projects, such as running a quantum-powered dating service, building an organ donor matching app, and breaking into quantum vaults. While working, quhackers could consult with scientists and engineers in attendance from sponsoring companies. Many sponsors also received feedback and ideas from quhackers to help improve their quantum platforms.

But organizing iQuHACK 2024 was no easy feat. Co-chairs Alessandro Buzzi and Daniela Zaidenberg led a committee of nine members to hold the largest iQuHACK yet. “It wouldn’t have been possible without them,” Buzzi said. The hackathon hosted 260 in-person quhackers and 1,000 remote quhackers, representing 77 countries in total. More than 20 scientists and engineers from sponsoring companies also attended in person as mentors for quhackers.

Each team of quhackers tackled one of 10 challenges posed by the hackathon’s eight major sponsoring companies. Some challenges asked quhackers to improve computing performance, such as by making quantum algorithms faster and more accurate. Other challenges asked quhackers to explore applying quantum computing to other fields, such as finance and machine learning. The sponsors worked with the iQuHACK committee to craft creative challenges with industry relevance and societal impact. “We wanted people to be able to address an interesting challenge [that has] applications in the real world,” says Zaidenberg.

One team of quhackers looked for potential quantum applications and found one close to home: dating. A team member, Liam Kronman, had previously built dating apps but disliked that matching algorithms for normal classical computers “require [an overly] strict setup.” With these classical algorithms, people must be split into two groups — for example, men and women — and matches can only be made between these groups. But with quantum computers, matching algorithms are more flexible and can consider all possible combinations, enabling the inclusion of multiple genders and gender preferences. 

Kronman and his team members leveraged these quantum algorithms to build a quantum-powered dating platform called MITqute (pronounced “meet cute”). To date, the platform has matched at least 240 people from the iQuHACK and MIT undergrad communities. In a follow-up survey, 13 out of 41 respondents reported having talked with their match, with at least two pairs setting up dates. “I really lucked out with this one,” one respondent wrote. 

Another team of quhackers also based their project on quantum matching algorithms but instead leveraged the algorithms’ power for medical care. The team built a mobile app that matches organ donors to patients, earning them the hackathon’s top social impact award. 

But they almost didn’t go through with their project. “At one point, we were considering scrapping the whole thing because we thought we couldn’t implement the algorithm,” says Alma Alex, one of the developers. After talking with their hackathon mentor for advice, though, the team learned that another group was working on a similar type of project — incidentally, the MITqute team. Knowing that others were tackling the same problem inspired them to persevere.

A sense of community also helped to motivate other quhackers. For one of the challenges, quhackers were tasked with hacking into 13 virtual quantum vaults. Teams could see each other’s progress on each vault in real time on a leaderboard, and this knowledge informed their strategies. When the first vault was successfully hacked by a team, progress from many other teams spiked on that vault and slowed down on others, says Daiwei Zhu, a quantum applications scientist at IonQ and one of the challenge’s two architects.

The vault challenge may appear to be just a fun series of puzzles, but the solutions can be used in quantum computers to improve their efficiency and accuracy. To hack into a vault, quhackers had to first figure out its secret key — an unknown quantum state — using a maximum of 20 probing tests. Then, they had to change the key’s state to a target state. These types of characterizations and modifications of quantum states are “fundamental” for quantum computers to work, says Jason Iaconis, a quantum applications engineer at IonQ and the challenge’s other architect. 

But the best way to characterize and modify states is not yet clear. “Some of the [vaults] we [didn’t] even know how to solve ourselves,” Zhu says. At the end of the hackathon, six vaults had at least one team mostly hack into them. (In the quantum world where gray areas exist, it’s possible to partly hack into a vault.)

The community of scientists and engineers formed at iQuHACK persists beyond the weekend, and many members continue to grow the community outside the hackathon. Inspired quhackers have gone on to start their own quantum computing clubs at their universities. A few years ago, a group of undergraduate quhackers from different universities formed a Quantum Coalition that now hosts their own quantum hackathons. “It’s crazy to see how the hackathon itself spreads and how many people start their own initiatives,” co-chair Zaidenberg says. 

The three-day hackathon opened with a keynote from MIT Professor Will Oliver, which included an overview of basic quantum computing concepts, current challenges, and computing technologies. Following that were industry talks and a panel of six industry and academic quantum experts, including MIT Professor Peter Shor, who is known for developing one of the most famous quantum algorithms. The panelists discussed current challenges, future applications, the importance of collaboration, and the need for ample testing.

Later, sponsors held technical workshops where quhackers could learn the nitty-gritty details of programming on specific quantum platforms. Day one closed out with a talk by research scientist Xinghui Yin on the role of quantum technology at LIGO, the Laser Interferometer Gravitational-Wave Observatory that first detected gravitational waves. The next day, the hackathon’s challenges were announced at 10 a.m., and hacking kicked off at the MIT InnovationHQ. In the afternoon, attendees could also tour MIT quantum computing labs.

Hacking continued overnight at the MIT Museum and ended back at MIT iHQ at 10 a.m. on the final day. Quhackers then presented their projects to panels of judges. Afterward, industry speakers gave lightning talks about each of their company’s latest quantum technologies and future directions. The hackathon ended with a closing ceremony, where sponsors announced the awards for each of the 10 challenges. 

The hackathon was captured in a three-part video by Albert Figurt, a resident artist at MIT. Figurt shot and edited the footage in parallel with the hackathon. Each part represented one day of the hackathon and was released on the subsequent day.

Throughout the weekend, quhackers and sponsors consistently praised the hackathon’s execution and atmosphere. “That was amazing … never felt so much better, one of the best hackathons I did from over 30 hackathons I attended,” Abdullah Kazi, a quhacker, wrote on the iQuHACK Slack.

Ultimately, “[we wanted to] help people to meet each other,” co-chair Buzzi says. “The impact [of iQuHACK] is scientific in some way, but it’s very human at the most important level.”

Making the clean energy transition work for everyone

Fri, 03/15/2024 - 5:00pm

The clean energy transition is already underway, but how do we make sure it happens in a manner that is affordable, sustainable, and fair for everyone?

That was the overarching question at this year’s MIT Energy Conference, which took place March 11 and 12 in Boston and was titled “Short and Long: A Balanced Approach to the Energy Transition.”

Each year, the student-run conference brings together leaders in the energy sector to discuss the progress and challenges they see in their work toward a greener future. Participants come from research, industry, government, academia, and the investment community to network and exchange ideas over two whirlwind days of keynote talks, fireside chats, and panel discussions.

Several participants noted that clean energy technologies are already cost-competitive with fossil fuels, but changing the way the world works requires more than just technology.

“None of this is easy, but I think developing innovative new technologies is really easy compared to the things we’re talking about here, which is how to blend social justice, soft engineering, and systems thinking that puts people first,” Daniel Kammen, a distinguished professor of energy at the University of California at Berkeley, said in a keynote talk. “While clean energy has a long way to go, it is more than ready to transition us from fossil fuels.”

The event also featured a keynote discussion between MIT President Sally Kornbluth and MIT’s Kyocera Professor of Ceramics Yet-Ming Chiang, in which Kornbluth discussed her first year at MIT as well as a recently announced, campus-wide effort to solve critical climate problems known as the Climate Project at MIT.

“The reason I wanted to come to MIT was I saw that MIT has the potential to solve the world’s biggest problems, and first among those for me was the climate crisis,” Kornbluth said. “I’m excited about where we are, I’m excited about the enthusiasm of the community, and I think we’ll be able to make really impactful discoveries through this project.”

Fostering new technologies

Several panels convened experts in new or emerging technology fields to discuss what it will take for their solutions to contribute to deep decarbonization.

“The fun thing and challenging thing about first-of-a-kind technologies is they’re all kind of different,” said Jonah Wagner, principal assistant director for industrial innovation and clean energy in the U.S. Office of Science and Technology Policy. “You can map their growth against specific challenges you expect to see, but every single technology is going to face their own challenges, and every single one will have to defy an engineering barrier to get off the ground.”

Among the emerging technologies discussed was next-generation geothermal energy, which uses new techniques to extract heat from the Earth’s crust in new places.

A promising aspect of the technology is that it can leverage existing infrastructure and expertise from the oil and gas industry. Many newly developed techniques for geothermal production, for instance, use the same drills and rigs as those used for hydraulic fracturing.

“The fact that we have a robust ecosystem of oil and gas labor and technology in the U.S. makes innovation in geothermal much more accessible compared to some of the challenges we’re seeing in nuclear or direct-air capture, where some of the supply chains are disaggregated around the world,” said Gabrial Malek, chief of staff at the geothermal company Fervo Energy.

Another technology generating excitement — if not net energy quite yet — is fusion, the process of combining, or fusing, light atoms together to form heavier ones for a net energy gain, in the same process that powers the sun. MIT spinout Commonwealth Fusion Systems (CFS) has already validated many aspects of its approach for achieving fusion power, and the company’s unique partnership with MIT was discussed in a panel on the industry’s progress.

“We’re standing on the shoulders of decades of research from the scientific community, and we want to maintain those ties even as we continue developing our technology,” CFS Chief Science Officer Brandon Sorbom PhD ’17 said, noting that CFS is one of the largest company sponsors of research at MIT and collaborates with institutions around the world. “Engaging with the community is a really valuable lever to get new ideas and to sanity check our own ideas.”

Sorbom said that as CFS advances fusion energy, the company is thinking about how it can replicate its processes to lower costs and maximize the technology’s impact around the planet.

“For fusion to work, it has to work for everyone,” Sorbom said. “I think the affordability piece is really important. We can’t just build this technological jewel that only one class of nations can afford. It has to be a technology that can be deployed throughout the entire world.”

The event also gave students — many from MIT — a chance to learn more about careers in energy and featured a startup showcase, in which dozens of companies displayed their energy and sustainability solutions.

“More than 700 people are here from every corner of the energy industry, so there are so many folks to connect with and help me push my vision into reality,” says GreenLIB CEO Fred Rostami, whose company recycles lithium-ion batteries. “The good thing about the energy transition is that a lot of these technologies and industries overlap, so I think we can enable this transition by working together at events like this.”

A focused climate strategy

Kornbluth noted that when she came to MIT, a large percentage of students and faculty were already working on climate-related technologies. With the Climate Project at MIT, she wanted to help ensure the whole of those efforts is greater than the sum of its parts.

The project is organized around six distinct missions, including decarbonizing energy and industry, empowering frontline communities, and building healthy, resilient cities. Kornbluth says the mission areas will help MIT community members collaborate around multidisciplinary challenges. Her team, which includes a committee of faculty advisors, has begun to search for the leads of each mission area, and Kornbluth said she is planning to appoint a vice president for climate at the Institute.

“I want someone who has the purview of the whole Institute and will report directly to me to help make sure this project stays on track,” Kornbluth explained.

In his conversation about the initiative with Kornbluth, Yet-Ming Chiang said projects will be funded based on their potential to reduce emissions and make the planet more sustainable at scale.

“Projects should be very high risk, with very high impact,” Chiang explained. “They should have a chance to prove themselves, and those efforts should not be limited by resources, only by time.”

In discussing her vision of the climate project, Kornbluth alluded to the “short and long” theme of the conference.

“It’s about balancing research and commercialization,” Kornbluth said. “The climate project has a very variable timeframe, and I think universities are the sector that can think about the things that might be 30 years out. We have to think about the incentives across the entire innovation pipeline and how we can keep an eye on the long term while making sure the short-term things get out rapidly.”

3 Questions: What you need to know about audio deepfakes

Fri, 03/15/2024 - 4:50pm

Audio deepfakes have had a recent bout of bad press after an artificial intelligence-generated robocall purporting to be the voice of Joe Biden hit up New Hampshire residents, urging them not to cast ballots. Meanwhile, spear-phishers — phishing campaigns that target a specific person or group, especially using information known to be of interest to the target — go fishing for money, and actors aim to preserve their audio likeness.

What receives less press, however, are some of the uses of audio deepfakes that could actually benefit society. In this Q&A prepared for MIT News, postdoc Nauman Dawalatabad addresses concerns as well as potential upsides of the emerging tech. A fuller version of this interview can be seen at the video below.

Q: What ethical considerations justify the concealment of the source speaker's identity in audio deepfakes, especially when this technology is used for creating innovative content?

A: The inquiry into why research is important in obscuring the identity of the source speaker, despite a large primary use of generative models for audio creation in entertainment, for example, does raise ethical considerations. Speech does not contain the information only about “who you are?” (identity) or “what you are speaking?” (content); it encapsulates a myriad of sensitive information including age, gender, accent, current health, and even cues about the upcoming future health conditions. For instance, our recent research paper on “Detecting Dementia from Long Neuropsychological Interviews” demonstrates the feasibility of detecting dementia from speech with considerably high accuracy. Moreover, there are multiple models that can detect gender, accent, age, and other information from speech with very high accuracy. There is a need for advancements in technology that safeguard against the inadvertent disclosure of such private data. The endeavor to anonymize the source speaker's identity is not merely a technical challenge but a moral obligation to preserve individual privacy in the digital age.

Q: How can we effectively maneuver through the challenges posed by audio deepfakes in spear-phishing attacks, taking into account the associated risks, the development of countermeasures, and the advancement of detection techniques?

A: The deployment of audio deepfakes in spear-phishing attacks introduces multiple risks, including the propagation of misinformation and fake news, identity theft, privacy infringements, and the malicious alteration of content. The recent circulation of deceptive robocalls in Massachusetts exemplifies the detrimental impact of such technology. We also recently spoke with the spoke with The Boston Globe about this technology, and how easy and inexpensive it is to generate such deepfake audios.

Anyone without a significant technical background can easily generate such audio, with multiple available tools online. Such fake news from deepfake generators can disturb financial markets and even electoral outcomes. The theft of one's voice to access voice-operated bank accounts and the unauthorized utilization of one's vocal identity for financial gain are reminders of the urgent need for robust countermeasures. Further risks may include privacy violation, where an attacker can utilize the victim’s audio without their permission or consent. Further, attackers can also alter the content of the original audio, which can have a serious impact.

Two primary and prominent directions have emerged in designing systems to detect fake audio: artifact detection and liveness detection. When audio is generated by a generative model, the model introduces some artifact in the generated signal. Researchers design algorithms/models to detect these artifacts. However, there are some challenges with this approach due to increasing sophistication of audio deepfake generators. In the future, we may also see models with very small or almost no artifacts. Liveness detection, on the other hand, leverages the inherent qualities of natural speech, such as breathing patterns, intonations, or rhythms, which are challenging for AI models to replicate accurately. Some companies like Pindrop are developing such solutions for detecting audio fakes. 

Additionally, strategies like audio watermarking serve as proactive defenses, embedding encrypted identifiers within the original audio to trace its origin and deter tampering. Despite other potential vulnerabilities, such as the risk of replay attacks, ongoing research and development in this arena offer promising solutions to mitigate the threats posed by audio deepfakes.

Q: Despite their potential for misuse, what are some positive aspects and benefits of audio deepfake technology? How do you imagine the future relationship between AI and our experiences of audio perception will evolve?

A: Contrary to the predominant focus on the nefarious applications of audio deepfakes, the technology harbors immense potential for positive impact across various sectors. Beyond the realm of creativity, where voice conversion technologies enable unprecedented flexibility in entertainment and media, audio deepfakes hold transformative promise in health care and education sectors. My current ongoing work in the anonymization of patient and doctor voices in cognitive health-care interviews, for instance, facilitates the sharing of crucial medical data for research globally while ensuring privacy. Sharing this data among researchers fosters development in the areas of cognitive health care. The application of this technology in voice restoration represents a hope for individuals with speech impairments, for example, for ALS or dysarthric speech, enhancing communication abilities and quality of life.

I am very positive about the future impact of audio generative AI models. The future interplay between AI and audio perception is poised for groundbreaking advancements, particularly through the lens of psychoacoustics — the study of how humans perceive sounds. Innovations in augmented and virtual reality, exemplified by devices like the Apple Vision Pro and others, are pushing the boundaries of audio experiences towards unparalleled realism. Recently we have seen an exponential increase in the number of sophisticated models coming up almost every month. This rapid pace of research and development in this field promises not only to refine these technologies but also to expand their applications in ways that profoundly benefit society. Despite the inherent risks, the potential for audio generative AI models to revolutionize health care, entertainment, education, and beyond is a testament to the positive trajectory of this research field.

Study finds lands used for grazing can worsen or help climate change

Fri, 03/15/2024 - 6:00am

When it comes to global climate change, livestock grazing can be either a blessing or a curse, according to a new study, which offers clues on how to tell the difference.

If managed properly, the study shows, grazing can actually increase the amount of carbon from the air that gets stored in the ground and sequestered for the long run. But if there is too much grazing, soil erosion can result, and the net effect is to cause more carbon losses, so that the land becomes a net carbon source, instead of a carbon sink. And the study found that the latter is far more common around the world today.

The new work, published today in the journal Nature Climate Change, provides ways to determine the tipping point between the two, for grazing lands in a given climate zone and soil type. It also provides an estimate of the total amount of carbon that has been lost over past decades due to livestock grazing, and how much could be removed from the atmosphere if grazing optimization management implemented. The study was carried out by Cesar Terrer, an assistant professor of civil and environmental engineering at MIT; Shuai Ren, a PhD student at the Chinese Academy of Sciences whose thesis is co-supervised by Terrer; and four others.

“This has been a matter of debate in the scientific literature for a long time,” Terrer says. “In general experiments, grazing decreases soil carbon stocks, but surprisingly, sometimes grazing increases soil carbon stocks, which is why it’s been puzzling.”

What happens, he explains, is that “grazing could stimulate vegetation growth through easing resource constraints such as light and nutrients, thereby increasing root carbon inputs to soils, where carbon can stay there for centuries or millennia.”

But that only works up to a certain point, the team found after a careful analysis of 1,473 soil carbon observations from different grazing studies from many locations around the world. “When you cross a threshold in grazing intensity, or the amount of animals grazing there, that is when you start to see sort of a tipping point — a strong decrease in the amount of carbon in the soil,” Terrer explains.

That loss is thought to be primarily from increased soil erosion on the denuded land. And with that erosion, Terrer says, “basically you lose a lot of the carbon that you have been locking in for centuries.”

The various studies the team compiled, although they differed somewhat, essentially used similar methodology, which is to fence off a portion of land so that livestock can’t access it, and then after some time take soil samples from within the enclosure area, and from comparable nearby areas that have been grazed, and compare the content of carbon compounds.

“Along with the data on soil carbon for the control and grazed plots,” he says, “we also collected a bunch of other information, such as the mean annual temperature of the site, mean annual precipitation, plant biomass, and properties of the soil, like pH and nitrogen content. And then, of course, we estimate the grazing intensity — aboveground biomass consumed, because that turns out to be the key parameter.”  

With artificial intelligence models, the authors quantified the importance of each of these parameters, those drivers of intensity — temperature, precipitation, soil properties — in modulating the sign (positive or negative) and magnitude of the impact of grazing on soil carbon stocks. “Interestingly, we found soil carbon stocks increase and then decrease with grazing intensity, rather than the expected linear response,” says Ren.

Having developed the model through AI methods and validated it, including by comparing its predictions with those based on underlying physical principles, they can then apply the model to estimating both past and future effects. “In this case,” Terrer says, “we use the model to quantify the historical loses in soil carbon stocks from grazing. And we found that 46 petagrams [billion metric tons] of soil carbon, down to a depth of one meter, have been lost in the last few decades due to grazing.”

By way of comparison, the total amount of greenhouse gas emissions per year from all fossil fuels is about 10 petagrams, so the loss from grazing equals more than four years’ worth of all the world’s fossil emissions combined.

What they found was “an overall decline in soil carbon stocks, but with a lot of variability.” Terrer says. The analysis showed that the interplay between grazing intensity and environmental conditions such as temperature could explain the variability, with higher grazing intensity and hotter climates resulting in greater carbon loss. “This means that policy-makers should take into account local abiotic and biotic factors to manage rangelands efficiently,” Ren notes. “By ignoring such complex interactions, we found that using IPCC [Intergovernmental Panel on Climate Change] guidelines would underestimate grazing-induced soil carbon loss by a factor of three globally.”

Using an approach that incorporates local environmental conditions, the team produced global, high-resolution maps of optimal grazing intensity and the threshold of intensity at which carbon starts to decrease very rapidly. These maps are expected to serve as important benchmarks for evaluating existing grazing practices and provide guidance to local farmers on how to effectively manage their grazing lands.

Then, using that map, the team estimated how much carbon could be captured if all grazing lands were limited to their optimum grazing intensity. Currently, the authors found, about 20 percent of all pasturelands have crossed the thresholds, leading to severe carbon losses. However, they found that under the optimal levels, global grazing lands would sequester 63 petagrams of carbon. “It is amazing,” Ren says. “This value is roughly equivalent to a 30-year carbon accumulation from global natural forest regrowth.”

That would be no simple task, of course. To achieve optimal levels, the team found that approximately 75 percent of all grazing areas need to reduce grazing intensity. Overall, if the world seriously reduces the amount of grazing, “you have to reduce the amount of meat that’s available for people,” Terrer says.

“Another option is to move cattle around,” he says, “from areas that are more severely affected by grazing intensity, to areas that are less affected. Those rotations have been suggested as an opportunity to avoid the more drastic declines in carbon stocks without necessarily reducing the availability of meat.”

This study didn’t delve into these social and economic implications, Terrer says. “Our role is to just point out what would be the opportunity here. It shows that shifts in diets can be a powerful way to mitigate climate change.”

“This is a rigorous and careful analysis that provides our best look to date at soil carbon changes due to livestock grazing practiced worldwide,” say Ben Bond-Lamberty, a terrestrial ecosystem research scientist at Pacific Northwest National Laboratory, who was not associated with this work. “The authors’ analysis gives us a unique estimate of soil carbon losses due to grazing and, intriguingly, where and how the process might be reversed.”

He adds: “One intriguing aspect to this work is the discrepancies between its results and the guidelines currently used by the IPCC — guidelines that affect countries’ commitments, carbon-market pricing, and policies.” However, he says, “As the authors note, the amount of carbon historically grazed soils might be able to take up is small relative to ongoing human emissions. But every little bit helps!”

“Improved management of working lands can be a powerful tool to combat climate change,” says Jonathan Sanderman, carbon program director of the Woodwell Climate Research Center in Falmouth, Massachusetts, who was not associated with this work. He adds, “This work demonstrates that while, historically, grazing has been a large contributor to climate change, there is significant potential to decrease the climate impact of livestock by optimizing grazing intensity to rebuild lost soil carbon.”

Terrer states that for now, “we have started a new study, to evaluate the consequences of shifts in diets for carbon stocks. I think that’s the million-dollar question: How much carbon could you sequester, compared to business as usual, if diets shift to more vegan or vegetarian?” The answers will not be simple, because a shift to more vegetable-based diets would require more cropland, which can also have different environmental impacts. Pastures take more land than crops, but produce different kinds of emissions. “What’s the overall impact for climate change? That is the question we’re interested in,” he says.

The research team included Juan Li, Yingfao Cao, Sheshan Yang, and Dan Liu, all with the  Chinese Academy of Sciences. The work was supported by the Second Tibetan Plateau Scientific Expedition and Research Program, and the Science and Technology Major Project of Tibetan Autonomous Region of China.

Envisioning a time when people age without fear of dementia

Fri, 03/15/2024 - 12:00am

The mathematician and computer scientist Richard Hamming once gave a talk about doing great research. “He who works with the door open gets all kinds of interruptions, but he also occasionally gets clues as to what the world is and what might be important,” Hamming said, emphasizing the importance of open-mindedness and scientific development.

William Li came across this quote as a high school student seeking to dedicate himself to research but unsure how to begin. “I think that science is kind of an opaque area to break into. It’s hard to know what you’re supposed to be doing from time to time,” Li explains.

A double-major in physics and computer science, Li has taken this advice to heart. Keeping his “office door” open has led him to a variety of research projects, from neuroimaging to genomics, that shaped his long-term goal: to become a physician-scientist who moves the needle on Alzheimer’s disease.

Li’s interest in working with patients in a clinical setting was spurred by his grandfather, who was a doctor. In high school, he began volunteering in retirement homes and at the Byrd Alzheimer’s Center and Research Institute at the University of South Florida. Through this work, Li witnessed the devastating effects Alzheimer’s disease has on both those diagnosed and their loved ones.

But that isn’t the only thing about Alzheimer’s that has grabbed his interest. With no cure available, and relatively little known about its cause, the disease is also a compelling scientific problem. “Beyond its human impact, Alzheimer’s represents a frontier of our understanding of human disease,” Li says.

Starting in the fall, Li will begin an MD/PhD program “for the better part of the coming decade.” Following that, he hopes to secure a residency in radiology or neurology, and then to teach and do research while simultaneously practicing medicine. His ultimate goal is a big one — to help develop a cure for Alzheimer’s.

Pursing knowledge

Research has been the highlight of Li’s career at MIT. He says, “To me personally, research means being able to contribute to a body of knowledge built upon by generations of minds in the past. I see modern science and technology as a pinnacle of human achievement, and it’s a dream come true to be able to add to this work.”

In a normal week during the academic semester, Li can spend up to 15 hours in the lab. His research projects have addressed very different topics, but both have guided him toward his current goals.

In the Soljačić and Johnson groups in the Research Laboratory of Electronics, Li he has worked in nanophotonics, a field concerned with controlling light by designing structures the size of a wavelength, for optical and X-ray images, among other applications. 

Li has worked on making X-ray imaging safer and more effective for medical screenings. He also focuses on using computational methods to design nanophotonic device elements for higher-resolution imaging. “Imaging technologies in the future will have pretty enormous applications both for understanding disease and for being able to catch diseases early through diagnosis,” he says.

In his sophomore year, Li began working at the lab of Professor Manolis Kellis at the Broad Institute of MIT and Harvard, using computational tools to study genetic variation among Alzheimer’s patients and how this relates to the disease itself. In this way, the disease can be broken down into subtypes, explains Li, which will make it easier to understand and treat. Last summer, Li won a SuperUROP Outstanding Research Award for this project.

Forging connections

When Li first joined the Kellis lab, the field of genomics seemed vast and overwhelming. To combat this, he started an academic journal club. In the club, Li and his peers would read research papers together and discuss them. In the fashion of a traditional journal club, one person would present at each meeting. Club participants encouraged each other to focus on any research they found exciting, ranging over the past century. As the club has continued, members have started to present their own research to the group as well. “It’s fun seeing what my friends are interested in,” Li says.

Li also served as the collegiate relations co-chair of MIT’s Pre-Medical Society. Here he was responsible for organizing an annual meeting between all pre-med students of the greater Boston area. This mixer was held for pre-med students to other local students and learn from pre-medical advisors and alumni of various Boston schools.

Among the several communities Li is a part of at MIT, his dormitory holds a special place in his heart. Next House, MIT’s largest dorm building, is the place Li has called home since his junior year. Since moving in, he has immersed himself in the living community by assuming roles in several activities hosted by the dorm, such as Thanksgiving dinner.

“I’m very happy to be part of the Next House community. It’s a pretty fantastic place, and I would say that my quality of social life has increased a lot since moving here,” he states.

Along with large events, Li also appreciates the weekly traditions he has created with his Next House friends. Each Sunday, for example, Li joins members of his dorm wing for a 15-minute workout. He says he enjoys exercising in the group setting and frequently attends the gym with his friends, too.

After some downtime on the weekends, Li heads back to the lab and his quest to better understand the brain and how it can be ravaged by dementia. As he continues on his path toward becoming a researcher and physician, he envisions a world where people can age without fear of illness.

2024 MacVicar Faculty Fellows named

Fri, 03/15/2024 - 12:00am

Four outstanding undergraduate teachers and mentors have been named MacVicar Faculty Fellows: professor of electrical engineering and computer science (EECS) Karl Berggren, professor of political science Andrea Campbell, associate professor of music Emily Richmond Pollock, and professor of EECS Vinod Vaikuntanathan.

For more than 30 years, the MacVicar Faculty Fellows Program has recognized exemplary and sustained contributions to undergraduate education at MIT. The program is named in honor of Margaret MacVicar, MIT’s first dean for undergraduate education and founder of the Undergraduate Research Opportunities Program (UROP).

New fellows are chosen each year through a highly competitive nomination process. They receive an annual stipend and are appointed to a 10-year term. Nominations, including letters of support from colleagues, students, and alumni, are reviewed by an advisory committee led by vice chancellor Ian Waitz with final selections made by provost Cynthia Barnhart.

Role models both in and out of the classroom, Berggren, Campbell, Pollock, and Vaikuntanathan join an elite academy of scholars from across the Institute who are committed to curricular innovation; exceptional teaching; collaboration with colleagues; and supporting students through mentorship, leadership, and advising.

Karl Berggren

“It is a great honor to have been selected for this fellowship. It has particularly made me remember the years of dedicated mentoring and support that I’ve received from my colleagues,” says Karl Berggren. “I’ve also learned a great deal over this period from our students by way of their efforts and thoughtful feedback. MIT continuously strives for excellence in undergraduate education, and I feel very lucky to have been part of that effort.”

Karl Berggren is the Joseph F. and Nancy P. Keithley Professor in the Department of EECS. He received his PhD from Harvard University and his BA in physics from Harvard College. Berggren joined MIT in 1996 as a staff member at Lincoln Laboratory before becoming an assistant professor in 2003. He regularly teaches undergraduate EECS offerings including 6.2000, formerly 6.002 (Electrical Circuits), and 6.3400, formerly 6.02 (Introduction to EECS via Communication Networks).

Sahil Pontula ’23 writes, “Professor Berggren turned 6.002 from a mere course requirement into a truly memorable experience that shaped my current research interests and provided a unique perspective … He is devoted not just to educating the next generation of engineers, but also to imbuing in them interdisciplinary problem-solving perspectives that push the frontiers of science forward.”

MacVicar Fellow and professor of EECS Jeffrey Lang notes, “His lectures are polished, presented with humor, and well-appreciated by his students.” Senior Tiffany Louie adds: “He connects with us, inspires us, and welcomes us to ask questions in class and in the greater electrical engineering field.”

Berggren is also deeply invested in the art and science of teaching. Tomás Palacios, professor of EECS, says, “Professor Berggren is genuinely interested in continuously improving the educational experience of our students. He approaches this in the same methodological and quantitative way we typically approach research. He is well-versed in the most modern theories about learning and he is always happy to share … relevant books and papers on the subject.”

Lang agrees, noting that Berggren “reads articles and books that examine and discuss how learning occurs so that he can become a more effective teacher.” He goes on to recall a conversation in which Berggren explained a new form of homework grading. Instead of reducing grades for errors that did not render an obviously flawed result, he helps students extract key takeaways from their assignments and come to correct solutions on their own. Lang notes that a key benefit of this approach is that it allows graders to “work much more quickly yet carefully” and “provides them more time to spend on giving helpful feedback.”

Adding to his long list of contributions, Berggren also oversees the EECS teaching labs. Since assuming this role, he has pursued changes to ensure that students feel comfortable and confident using the space for both coursework and outside projects, developing their critical thinking and hands-on skills.

Faculty head and professor of electrical engineering Joel Voldman applauds Berggren’s efforts: “Since [he] has taken over, the labs are now a place for projects of all sorts, with students being trained on various processes, parts being easy to obtain, equipment readily available … His fundamental mantra has been to make a space that serves students, meets them where they’re at, and helps them get to where they want to go.”

Andrea Campbell

Andrea Campbell received her BA in social studies from Harvard University and her MA and PhD in political science from the University of California at Berkeley. She joined MIT’s Department of Political Science in 2005 and is currently the Arthur and Ruth Sloan Professor of Political Science and director of undergraduate studies.

Professor Campbell regularly teaches classes 17.30 (Making Public Policy), 17.315 (Health Policy), and 17.317 (U.S. Social Policy). Her research examines the relationships between public policies, public opinion, and political behavior.

A unique aspect of Campbell’s teaching style is the personal approach she brings. In 17.315, Campbell shared her own experiences following a tragic accident in her family, which highlighted the real-life challenges that many face navigating America’s health care system.

According to David Singer, department head and the Raphael Dorman-Helen Starbuck Professor of Political Science, Campbell “weaves personal experience into her teaching in powerful ways … Her openness about her experience permits students to share their own … thereby strengthening their own engagement with the material.”

Singer goes on to say, “In all of her classes, [she] encourages students to examine policymaking not as a technocratic exercise, or an exercise of optimization, but rather as a process infused with politics. In steering her pedagogy in this way, she shows her students how to understand the identity and interests of different groups in society, where their relative power emanates from, and how the rules and institutions of the U.S. political system shape policy outcomes on critical issues like LGBTQ rights, gun control, military intervention, and health care.”

Students say her classes are incredibly impactful, lingering with them for years to come. Her former teaching assistant, now Harvard professor, Justin de Benedictis-Kessner wrote, “Andrea’s talents have been an enormous asset … I have seen how many of her former undergraduate students have gone on to successful careers adjacent to her field of public policy in large part because of her inspiration.” Echoing this sentiment, Julia H. Ginder ’19 writes, “her lessons and mentorship have impacted my day-to-day life and career trajectory even five years after graduation.”

Campbell’s work set the stage for wide-ranging improvements to the Course 17 curriculum and under her leadership, public policy has become the most popular minor in the department. Singer writes, “She ensures that required classes in political institutions, economics, and substantive policy areas are regularly taught, and she proselytizes … to students about the importance of understanding policymaking, especially to [those] in engineering and sciences who might otherwise overlook this critically important domain.”

Campbell is heavily involved with undergraduate advising at the department, school, and Institute levels. She is a popular sponsor of UROPs and attracts many undergraduate researchers each year. Campbell is also co-chair of the Gender Equity Committee in the School of Humanities, Arts, and Social Sciences (SHASS) and the Subcommittee on the Communication Requirement (SOCR).

“It is clear that Andrea takes undergraduate teaching extraordinarily seriously, not just when designing her own classes, but when leading the undergraduate program in our department,” says Adam Berinsky, the Mitsui Professor of Political Science.

Beyond her many pedagogical and curricular accomplishments, Singer notes: “Andrea’s students consistently tout her extraordinary degree of personal engagement. She takes the time to get to know students, to mentor them outside the classroom, and to keep them energized in the classroom. Many express gratitude for Andrea’s willingness to go the extra mile — by staying late after class, holding extra office hours, and even inviting students to her home for Thanksgiving dinner.”

On receiving this award Campbell writes, “I am so grateful to my colleagues and students for taking the time to nominate me and so honored to be selected. Teaching and mentoring MIT students is such a joy. I am well aware that some students come through my door just to fulfill a requirement. Others come with genuine enthusiasm and interest. Either way, I love watching them discover how fascinating political science is and how relevant politics and policymaking are for their lives and their futures.”

Emily Richmond Pollock

“I am truly thrilled to become a MacVicar Faculty Fellow. Working with the undergraduates at MIT is such a gift in itself. When I teach, I can only strive to match the students’ creativity and commitment with my own,” says Emily Richmond Pollock.

Pollock joined MIT’s faculty in 2012. She received her BA in music from Harvard University in 2006 and her MA and PhD in music history and literature from the University of California at Berkeley in 2008 and 2012. She was awarded MIT’s Arthur C. Smith Award for meaningful contributions and devotion to undergraduate student life and learning in 2019 and the James A. and Ruth Levitan Teaching Award from the SHASS in 2020. She currently serves on the SOCR, the Subcommittee on the HASS requirements, and is the inaugural undergraduate chair in the SHASS.

Pollock is a dedicated mentor and advisor and testimonials highlight her commitment to student well-being and intellectual development. “Professor Emily Richmond Pollock is a kind, intentional, and dedicated teacher and advisor,” says senior Katherine Reisig. “By fostering such a welcoming community, she helps the MIT music department be a better place. It is clear … [she] cares deeply about her students, not only that we are doing well academically, but also that we are succeeding in life and doing well mentally.”

MacVicar Faculty Fellow and associate professor of literature Marah Gubar agrees: “Emily has long served as a role model for how to support the ‘whole student’ in ways that build community, right wrongs, and infuse more humanity and beauty into our campus.”

MIT colleagues and students praise Pollock’s extensive contributions to curriculum development at the introductory and advanced levels. She regularly teaches class 21M.011 (Introduction to Western Music) and courses on opera, symphonic repertoire, and the advanced seminar for music majors. Her lectures provide lively learning experiences in which her students are encouraged to think critically about music and culture, dive into unfamiliar operas with curiosity, and compare dramatic elements across time periods.

“I came away from 21M.011 not only with a better understanding of Western music, but with new curiosities and questions about music’s role in the world. Professor Pollock’s teaching made me want to learn more  it encouraged lifelong discovery, curiosity, and education,” Reisig says.

Associate professor of music and MacVicar Faculty Fellow Patricia Tang writes, “Professor Pollock continues to grow as a leader in pedagogical innovation, transforming the music history curriculum and being a true inspiration to her colleagues in her devotion to her students. Though these subjects existed in the course catalog before Pollock’s arrival, in all cases she has radically transformed them, infusing new energy and excitement into the curriculum.”

Pollock also champions issues of diversity, equity, and inclusion in the arts and is dedicated to making classical music and opera more accessible while maintaining the intellectual prestige applauded by students. She encourages students to embrace lesser-known works and step outside their comfort zone, even taking students to the opera herself. She has a “strong interest in anti-racist pedagogies and decolonizing music curriculum … [her] pedagogical innovations are numerous,” Tang observes.

About her impact as an advisor, Tang notes: “Professor Pollock genuinely loves getting to know her students … it is really her ‘superpower.’ It is her mission to make sure [they] are not just surviving but thriving in their first year.”

Senior Hana Ro agrees: “Under her guidance, my academic journey has been transformed, and I have gained not only a profound understanding of [this] subject matter but also a sense of belonging and encouragement that has been invaluable during my time at MIT.”

Furthermore, Pollock ensures that students never feel isolated or alone. Graduate student Frederick Ajisafe says, “If she knew that a cohort was taking a demanding class, she would check in with us … In all cases, Emily emphasized her belief in our ability to succeed and her willingness to help us get there.”

Vinod Vaikuntanathan

Vinod Vaikuntanathan is a professor in the Department of EECS. He received his bachelor’s degree in computer science from the Indian Institute of Technology Madras in 2003 and his SM and PhD degrees in computer science from MIT in 2005 and 2009. Vaikuntanathan joined the faculty in 2013 and in recognition of his contributions to teaching and service to students, he received the Harold E. Edgerton Faculty Achievement Award in 2017 and the Ruth and Joel Spira Award for Distinguished Teaching in 2016.

Vaikuntanathan has taught all three EECS undergraduate theoretical computer science subjects including 6.1210, formerly 6.006 (Introduction to Algorithms); 6.1200, formerly 6.042 (Mathematics for Computer Science); and 6.1220, formerly 6.046 (Design and Analysis of Algorithms).

Students say his classes are challenging, yet approachable and inclusive. Helen Propson ’24 writes, “He excels at making complex subjects like cryptography accessible and captivating for all students, creating an atmosphere where every student’s input is highly regarded. He embraces questions and leaves students feeling inspired and motivated to tackle challenging problems, fostering a sense of confidence and a belief in their own abilities.” She goes on to say, “He often describes intricate concepts as ‘magical,’ and his enthusiasm is contagious, making the material come alive in the classroom.”

MIT alumna Anne Kim concurs: “His teaching style is characterized by its clarity, enthusiasm, and a genuine passion for the subject matter. In his classes, he managed to distill complex algorithms into digestible concepts, making the material accessible to students with varying levels of expertise.”

Vaikuntanathan has also made significant contributions to the EECS curriculum. In spring 2022, he, along with fellow professors in the department, led an effort to improve 6.046. According to professor of EECS and MacVicar Fellow Srini Devadas, “designing a new lecture for 6.046 is not easy. Each new lecture is, typically, days of prep work, including preparing to … give the lecture itself and writing and testing problem set questions, quiz questions, and quiz practice questions. Vinod did all this with skill, aplomb, and enthusiasm. His contributions have had a permanent and beneficial effect on 6.046.”

Widely known for his work in cryptography, including homomorphic encryption and computational complexity, Vaikuntanathan became the lecturer-in-charge of the department’s first theoretical cryptography offering, 6.875. In addition, as the fields of quantum and post-quantum cryptography have grown, “Vinod has added relevant modules to the syllabus, taking the place of topics which had grown obsolete,” Devadas remarks. “Some professors might see teaching the same class multiple times as a chance to save themselves work by reusing the same materials. Vinod sees teaching 6.875 every fall as an opportunity to keep improving the class.”

Vinod Vaikuntanathan is also a devoted mentor and advisor, assisting with first-year UROPs and encouraging students to take advantage of his “open-door” policy. Kim writes that Professor Vaikuntanathan is benefiting her career still as “his mentorship ... extends beyond the classroom through his research” and that he “has mentored and advised dozens of [her] friends in the cryptography space.”

“His encouraging demeanor sets a remarkable example of the kind of teacher every student hopes to encounter during their academic career,” says Propson.

On becoming a MacVicar Faculty Fellow Vaikuntanathan writes, “It is humbling to be in the company of such amazing teachers and mentors, many of whom I have come to think of as my role models. Many thanks to my colleagues and my students for considering me worthy of this honor.”

Researchers help robots navigate efficiently in uncertain environments

Thu, 03/14/2024 - 12:00am

If a robot traveling to a destination has just two possible paths, it needs only to compare the routes’ travel time and probability of success. But if the robot is traversing a complex environment with many possible paths, choosing the best route amid so much uncertainty can quickly become an intractable problem.

MIT researchers developed a method that could help this robot efficiently reason about the best routes to its destination. They created an algorithm for constructing roadmaps of an uncertain environment that balances the tradeoff between roadmap quality and computational efficiency, enabling the robot to quickly find a traversable route that minimizes travel time.

The algorithm starts with paths that are certain to be safe and automatically finds shortcuts the robot could take to reduce the overall travel time. In simulated experiments, the researchers found that their algorithm can achieve a better balance between planning performance and efficiency in comparison to other baselines, which prioritize one or the other.

This algorithm could have applications in areas like exploration, perhaps by helping a robot plan the best way to travel to the edge of a distant crater across the uneven surface of Mars. It could also aid a search-and-rescue drone in finding the quickest route to someone stranded on a remote mountainside.

“It is unrealistic, especially in very large outdoor environments, that you would know exactly where you can and can’t traverse. But if we have just a little bit of information about our environment, we can use that to build a high-quality roadmap,” says Yasmin Veys, an electrical engineering and computer science (EECS) graduate student and lead author of a paper on this technique.

Veys wrote the paper with Martina Stadler Kurtz, a graduate student in the MIT Department of Aeronautics and Astronautics, and senior author Nicholas Roy, an MIT professor of aeronautics and astronautics and a member of the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL). The research will be presented at the International Conference on Robotics and Automation.

Generating graphs

To study motion planning, researchers often think about a robot’s environment like a graph, where a series of “edges,” or line segments, represent possible paths between a starting point and a goal.

Veys and her collaborators used a graph representation called the Canadian Traveler’s Problem (CTP), which draws its name from frustrated Canadian motorists who must turn back and find a new route when the road ahead is blocked by snow.

In a CTP, each edge of the graph has a weight associated with it, which represents how long that path will take to traverse, and a probability of how likely it is to be traversable. The goal in a CTP is to minimize travel time to the destination.

The researchers focused on how to automatically generate a CTP graph that effectively represents an uncertain environment.

“If we are navigating in an environment, it is possible that we have some information, so we are not just going in blind. While it isn’t a detailed navigation plan, it gives us a sense of what we are working with. The crux of this work is trying to capture that within the CTP graph,” adds Kurtz.

Their algorithm assumes this partial information — perhaps a satellite image — can be divided into specific areas (a lake might be one area, an open field another, etc.)

Each area has a probability that the robot can travel across it. For instance, it is more likely a nonaquatic robot can drive across a field than through a lake, so the probability for a field would be higher.

The algorithm uses this information to build an initial graph through open space, mapping out a conservative path that is slow but definitely traversable. Then it uses a metric the team developed to determine which edges, or shortcut paths through uncertain regions, should be added to the graph to cut down on the overall travel time.

Selecting shortcuts

By only selecting shortcuts that are likely to be traversable, the algorithm keeps the planning process from becoming needlessly complicated.

“The quality of the motion plan is dependent on the quality of graph. If that graph doesn’t have good paths in it, then the algorithm can’t give you a good plan,” Veys explains.

After testing the algorithm in more than 100 simulated experiments with increasingly complex environments, the researchers found that it could consistently outperform baseline methods that don’t consider probabilities. They also tested it using an aerial campus map of MIT to show that it could be effective in real-world, urban environments.

In the future, they want to enhance the algorithm so it can work in more than two dimensions, which could enable its use for complicated robotic manipulation problems. They are also interested in studying the mismatch between CTP graphs and the real-world environments those graphs represent.

“Robots that operate in the real world are plagued by uncertainty, whether in the available sensor data, prior knowledge about the environment, or about how other agents will behave. Unfortunately, dealing with these uncertainties incurs a high computational cost,” says Seth Hutchinson, professor and KUKA Chair for Robotics in the School of Interactive Computing at Georgia Tech, who was not involved with this research. “This work addresses these issues by proposing a clever approximation scheme that can be used to efficiently compute uncertainty-tolerant plans.”

This research was funded, in part, by the U.S. Army Research Labs under the Distributed Collaborative Intelligent Systems and Technologies Collaborative Research Alliance and by the Joseph T. Corso and Lily Corso Graduate Fellowship.

Study finds workers misjudge wage markets

Thu, 03/14/2024 - 12:00am

Many employees believe their counterparts at other firms make less in salary than is actually the case — an assumption that costs them money, according to a study co-authored by MIT scholars.

“Workers wrongly anchor their beliefs about outside options on their current wage,” says MIT economist Simon Jäger, co-author of a newly published paper detailing the study’s results.

As a top-line figure, the study indicates that workers who would experience a 10 percent wage increase by switching firms only expect a 1 percent wage increase instead, leading them to earn less than they otherwise might.

That is one of multiple related findings in the study, which also shows that workers in lower-paying firms are highly susceptible to underestimating wages at other companies; and that giving workers correct information about the salary structure in their industry makes them more likely to declare that they intend to leave their current jobs.

The study also has implications for further economics research, since economists’ job-search models generally assume workers have accurate salary information about their industries. The study was performed using data from Germany, although it quite likely applies to other countries as well.

“Misperceptions about outside options have substantial consequences on wages,” says Nina Roussille, an economist at MIT and also a co-author of the paper. “The intuition is simple: If low-wage workers do not know that they could make more elsewhere, then these workers stay put in low-wage firms. In turn, these low-wage firms do not feel the competitive pressure from the external labor market to raise their wages.”

The paper, “Worker Beliefs about Outside Options,” appears in advance online form in the Quarterly Journal of Economics. The authors are Jäger, the Silverman Family Career Development Associate Professor in MIT’s Department of Economics; Christopher Roth, a professor of economics at the University of Cologne; Roussille, an assistant professor in MIT’s Department of Economics; and Benjamin Schoefer, an associate professor of economics at the University of California at Berkeley.

Updating beliefs

To conduct the study, the researchers incorporated a survey module into the Innovation Sample of the German Socio-Economic Panel, an annual survey of a representative sample of the German population. They used their survey questions to find out the nature of worker beliefs about outside employment opportunities. The scholars then linked these findings to actual job and salary data collected from the German government’s Institute for Employment Research (IAB), with the prior consent of 558 survey respondents.

Linking those two data sources allowed the scholars to quantify the mismatch between what workers believe about industry-wide salaries, and what wages are in reality. One good piece of evidence on the compression of those beliefs is that about 56 percent of respondents believe they have a salary in between the 40th and 60th percentiles among comparable workers.

The scholars then added another element to the research project. They conducted an online experiment with 2,448 participants, giving these workers correct information about salaries at other companies, and then measuring the employees’ intention to find other job opportunities, among other things.

By adding this layer to the study, the scholars found that a 10 percentage point increase in the belief about salaries at other firms leads to a 2.6 percentage point increase in a worker intending to leave their present firm.

“This updating of beliefs causes workers to adjust their job search and wage negotiation intentions,” Roussille observes.

While the exact circumstances in every job market may vary somewhat, the researchers think the basic research findings from Germany could well apply in many other places.

“We are confident the results are representative of the German labor market,” Jäger says. “Of course, the German labor market may differ from, say, the U.S. labor market. Our intuition, though, is that, if anything, misperceptions would be even more consequential in a country like the U.S. where wages are more unequal than in Europe.”

Moreover, he adds, the recent dynamics of the U.S. job market during the Covid-19 pandemic, when many workers searched for new work and ended up in higher-paying jobs, is “consistent with the idea that workers had been stuck in low-paying jobs for a long time without realizing that there may have been better opportunities elsewhere.”

Data informing theory

The findings of Jäger, Roth, Roussille, Schoefer stand in contrast to established economic theory in this area, which has often worked from the expectation that employees have an accurate perception of industry wages and make decisions on that basis.

Roussille says the feedback the scholars have received from economics colleagues has been favorable, since other economists perceive “an opportunity to better tailor our models to reality,” as she puts it. “This follows a broader trend in economics in the past 20 to 30 years: The combination of better data collection and access with greater computing power has allowed the field to challenge longstanding but untested assumptions, learn from new empirical evidence, and build more realistic models.”

The findings have also encouraged the scholars to explore the topic further, especially by examining what the state of industry-wide wage knowledge is among employers.

“One natural follow-up to this project would be to better understand the firm side,” Jäger says. “Are firms aware of these misperceptions? Do they also hold inaccurate beliefs about the wages at their competitors?”

To this end, the researchers have already conducted a survey of managers on this topic, and intend to pursue further related work.

Support for the research was provided, in part, by the Sloan Foundation’s Working Longer Program; the Stiftung Grundeinkommen (Basic Income Foundation); and the Deutsche Forschungsgemeinschaft (German Research Foundation) under Germany’s Excellence Strategy.

“Imagine it, build it” at MIT

Thu, 03/14/2024 - 12:00am

MIT class 2.679 (Electronics for Mechanical Systems II) offers a sort of alchemy that transforms students from consumers of knowledge to explorers and innovators, and equips them with a range of important new tools at their disposal, students say.

“Topics which could otherwise feel intimidating are well-scoped each week so that students come out knowing not only what a concept is, but why it’s useful and how to actually implement it,” says graduating senior Audrey Chen. “I could consistently come in with no background and come out with practical experience I could use in future projects. I’d describe the class as a series of small crash courses [each of which] answers, simply, ‘what do I need to know to do or use this thing?’”

The course takes students through the process of design, fabrication, and assembly of a printed circuit board (PCB). Ultimately, that process, which has twists and turns depending on each student’s project idea, culminates in incorporating the PCB into a device — in a sense animating that device to perform a certain function.

“The design intent of 2.679 is to empower students to ‘imagine it, build it,’” says Tonio Buonassisi, professor of mechanical engineering. "Between those two is a universe, and the purpose of this class is to aid aspiring engineers to bridge that gap.”

Senior Jessica Lam marvels at how much she learned in the course over its one short semester, attributing that flood of education to the class labs being “incredibly well-structured.”

“I’ve found that in a lot of other labs and project-based classes, they throw a lot of information at you at once with the expectation that you already have some experience with certain software or hardware, and most of it is scaffolded and feels like a black box,” without much understanding of what is actually happening, Lam says. “In 2.679, Steve Banzaert has a better understanding of what we already know and how to build on that.”

After taking 2.679, she says she feels “a lot more confident in designing electrical systems, and I have a more comprehensive understanding of how to integrate mechanical systems and electronics.”

Banzaert, technical instructor for the course, says the class is designed to guide students along their own chosen paths of discovery, showing them that they are able to address the challenges they encounter along the way.

“Every semester we get to see really lovely examples of growth, not just in the course material but, in the best cases, in students’ understanding of what they’re really capable of,” he says.

Chen, a mechanical engineering major who is graduating early to start a position as a hardware project manager at Formlabs, agrees that the class did just that.

“Students are given tremendous freedom to pick their own final projects, allowing them to explore topics which are of special interest to them. And because each project is unique, there is less pressure to ‘perform’ in a traditional sense,” she says. “Rather, each student is learning different skills and is encouraged to get as far along with the project they choose as possible. Steve emphasized that the scope of our projects would inevitably change, because at the start you simply don’t yet know what you don’t know, and that’s totally okay!”

Banzaert says, “We try to make it very clear that, yes, we are talking about important general concepts in theory and analysis, but that’s because they are tools that engineers use to solve problems. I think maybe this focus helps remind the students of what got them here in the first place — that the reason you’re an engineer is because there’s something about the world you wish was better, that you’re the person to do it (or at least help), and, if you want to do it well, you’re going to have to learn a bunch of things so you have more tools in your toolbox.”

Senior Yasin Hamed designed a car in the class that uses computer vision to follow along a black line. The car has an attached camera that captures images and relays them to a Raspberry Pi computer that is also attached to the car. Processing the images in real time allows the car to locate the black line and turn or go straight while controlling the car’s speed.

Although Hamed, who is majoring in mechanical engineering with a minor in computer science, had built another similar system in a previous class, he says the focus in the prior class was on the software. With his 2.679 car project, he learned about “the underlying foundation,” meaning “the design of the power electronics and control circuitry which is necessary for everything else to work.”

“I derived much of the ‘enlightenment’ from this class from the little electronic bits and pieces of information I picked up along the course of the class, like learning/practicing soldering, understand how to use integrated circuits, learning how to design a PCB, etc.,” he says. “It was the collection of all of these things that benefited me the most.”

Jordan Parker-Ashe, also a senior, appreciated how 2.679 combined lessons about electronics with research and presentations from Buonassisi’s lab. “It’s great seeing engineering applied in research,” she says.

Although many of the skills she learned in the course were new to her, one was “an old foe,” she says, that 2.679 allowed her to befriend. Parker-Ashe, who is majoring in nuclear engineering, had used a computer vision program called OpenCV in her first Undergraduate Research Opportunities Program project as a first-year undergraduate.

“It was the hardest thing ever, and it really felt like an insurmountable obstacle then,” she says. “Now, to be using OpenCV in labs and homework effortlessly — It was a very full-circle moment.”

She says the class has opened up a whole new field to her, with Banzaert having “directly inspired” her to also take class 6.131 (Power Electronics), “which has been life-changing,” she says.

“2.679 helped me believe in myself, which inspired me to take 6.131, a notorious electrical engineering capstone, which has made me realize that my future lies as a nuclear-electrical engineering engineer, not just a nuclear engineer,” Parker-Ashe says. “I want to pursue electrical engineering in my future, and that just wasn’t on the table beforehand.

“Not to mention that it’s opened the doors to very rich landscapes for project ideas, creating explorations, art, stepping into new roles in group projects, etc,” she says. "I'm so glad that I've been able to find opportunities in Course 2  that helped give me hands-on, applied engineering experience."

Life on Mars, together

Wed, 03/13/2024 - 5:00pm

Earlier this year, Madelyn Hoying, a PhD student in the Harvard-MIT Program in Health Sciences and Technology, and Wing Lam (Nicole) Chan, an MIT senior in aeronautics and astronautics, were part of Crew 290 at the Mars Desert Research Station (MDRS), the largest and longest-running Mars analog facility in the world. Their six-person crew completed a two-week simulation under the name Project MADMEN (Martian Analysis and Detection of Microbial Environments) — an analog of potential Martian search-for-life missions. 

The mission evolved from Hoying’s NASA Revolutionary Aerospace Systems Concepts – Academic Linkage (NASA RASC-AL) challenge submission, Project ALIEN, during her time as an undergraduate student at Duquesne University. After the challenge concluded, she and her colleagues refined the mission concept and created a test plan that could be conducted in a Mars-analog environment. 

Hoying served as the crew’s commander and health and safety officer, and Chan as the crew’s journalist, documenting daily activities and how the crew experienced life on Mars. The other members of Crew 290 featured three from the original project: Hoying, Rebecca McCallin from Duquesne University, and Benjamin Kazimer from MIT Lincoln Laboratory. Chan, Anja Sheppard from the University of Michigan, and Anna Tretiakova from Boston University joined the team in the next phase. Hoying and Chan had worked together once before in 2022 in another RASC-AL competition. 

“I was initially a bit skeptical of spending two weeks in the middle of nowhere and simply being tasked with writing about what happens every day,” says Chan. “What happens on extravehicular activities (EVAs)? How and where do we live every day? What will we be eating? These doubts all went away with the adrenaline and curiosity of seeing the Martian-esque landscape and especially after putting on the EVA helmet for the first time. It truly felt like I was living on Mars and I very quickly immersed myself in the mission.” 

A unique leadership opportunity

Hoying has participated in other analog missions through MIT’s RASC-AL challenge submissions, specifically 2023’s Pale Red Dot. “I have led an analog mission in the past with [MIT AeroAstro colleague] George Lordos. We led a total crew of 11 in a dual-site mission architecture, where George led one habitat and I led the other. Pale Red Dot and Project MADMEN emphasized different features of a Martian mission, so certain aspects of this, like the extravehicular activity procedures and reporting requirements for mission support, were different.”

As commander, Hoying managed logistics, including balancing the scientific objectives of the multiple projects the crew set out to complete. “The two field experiments were soil collection for Project MADMEN and field operation of REMI, the ground-penetrating radar robot. Sometimes this led to competing requirements for EVAs, as REMI’s mass would reduce the distance that our rovers could cover before running out of battery and therefore limit the terrain types that could be reached for soil collection.” 

Hoying’s main focus was balancing the crew’s requirements for data with safety, including such considerations as who had recently been on EVA, who needed a break from carrying the heavy EVA suits, how far the team could safely travel, and how the weather impacted different areas. “The decisions for what the science goals of an EVA were, who would go on each EVA, and where they would be to collect from came down to me. Ultimately, we were able to balance all of these and satisfy the collection requirements of both field projects, even with last-minute changes due to things like weather.”

The crew makes the mission

Project MADMEN involved conducting onsite field tests of geological samples and robotic experiments for landing site selection. But the success of the mission hinged on more than just in-lab results. Hosting the mission at MDRS allowed the MADMEN crew to gain valuable insights on how individuals and teams might actually experience life on Mars, psychologically and socially. 

“We had a great crew, and as a result we had a great mission,” says Hoying. She managed the psychosocial aspect of the mission using daily questionnaires, studying the effects of contingency and emergency scenarios on metrics like quality of life.

The main living quarters for the crew is a two-story, 8-meter diameter cylinder called the “Hab.” The lower deck comprises the EVA prep room, an airlock, bathroom facilities, and a tunnel to the other structures. The upper deck houses the living quarters, including a kitchen and bunks. The close quarters only served to solidify the crew’s enthusiasm for the mission and support of each other.

“We shared almost every meal together and used the time to bond and talk about our interests. We often ended the day with social activities, whether it be talking about our backgrounds or future plans, playing games, or stargazing,” says Chan. “The most challenging part for me personally was stepping out of my comfort zone. Prior to this mission, I have not lived communally or camped before. It took me a bit to get used to living in close quarters with other people and balancing chores and tasks. I soon got used to the routine and enjoyed trying things for the first time, which made my experience a lot more rewarding, too.”

By day (or “Sol”) 3, the crew had assigned nicknames to each other in a call-sign ceremony. “It’s a tradition in other field experiences I’ve been a part of, and I wanted to carry that through for this crew. Assigning these was a night full of storytelling, laughing, and new memories, and we all agreed that the reasoning behind each nickname assignment would remain between the crew,” says Hoying (“Melon”); Chan’s call sign was “PODO.” 

Crew 290’s Martian journals close with a reflection from Chan on their out-of-this-world experience: “As we get to work tonight, we reminisce about our time here on Mars, from the first time setting foot in the station to the first time suiting up for EVAs. We’re all so grateful to be here and have learned a lot about what it takes to be a Martian during the past two weeks.” Read all of Chan’s journal updates here.

The mission was primarily sponsored by Duquesne University and the Pennsylvania Space Grant Consortium, with some travel support provided by the Massachusetts Space Grant Consortium.

Letting the Earth answer back: Designing better planetary conversations

Wed, 03/13/2024 - 4:30pm

For Chen Chu MArch ’21, the invitation to join the 2023-24 cohort of Morningside Academy for Design Design Fellows has been an unparalleled opportunity to investigate the potential of design as an alternative method of problem-solving.

After earning a master’s degree in architecture at MIT and gaining professional experience as a researcher at an environmental nongovernmental organization, Chu decided to pursue a PhD in the Department of Urban Studies and Planning. “I discovered that I needed to engage in a deeper way with the most difficult ethical challenges of our time, especially those arising from the fact of climate change,” he explains. “For me, MIT has always represented this wonderful place where people are inherently intellectually curious — it’s a very rewarding community to be part of.”

Chu’s PhD research, guided by his doctoral advisor Delia Wendel, assistant professor of urban studies and international development, focuses on how traditional practices of floodplain agriculture can inform local and global strategies for sustainable food production and distribution in response to climate change. 

Typically located alongside a river or stream, floodplains arise from seasonal flooding patterns that distribute nutrient-rich silt and create connectivity between species. This results in exceptionally high levels of biodiversity and microbial richness, generating the ideal conditions for agriculture. It’s no accident that the first human civilizations were founded on floodplains, including Mesopotamia (named for its location poised between two rivers, the Euphrates and Tigris), the Indus River Civilization, and the cultures of Ancient Egypt based around the Nile. Riverine transportation networks and predictable flooding rhythms provide a framework for trade and cultivation; nonetheless, floodplain communities must learn to live with risk, subject to the sudden disruptions of high waters, drought, and ecological disequilibrium. 

For Chu, the “unstable and ungovernable” status of floodplains makes them fertile ground for thinking about. “I’m drawn to these so-called ‘wet landscapes’ — edge conditions that act as transitional spaces between land and water, between humans and nature, between city and river,” he reflects. “The development of extensively irrigated agricultural sites is typically a collective effort, which raises intriguing questions about how communities establish social organizations that simultaneously negotiate top-down state control and adapt to the uncertainty of nature.”

Chu is in the process of honing the focus of his dissertation and refining his data collection methods, which will include archival research and fieldwork, as well as interviews with floodplain inhabitants to gain an understanding of sociopolitical nuances. Meanwhile, his role as a design fellow gives him the space to address the big questions that fire his imagination. How can we live well on shared land? How can we take responsibility for the lives of future generations? What types of political structures are required to get everyone on board? 

These are just a few of the questions that Chu recently put to his cohort in a presentation. During the weekly seminars for the fellowship, he has the chance to converse with peers and mentors of multiple disciplines — from researchers rethinking the pedagogy of design to entrepreneurs applying design thinking to new business models to architects and engineers developing new habitats to heal our relationship with the natural world. 

“I’ll admit — I’m wary of the human instinct to problem-solve,” says Chu. “When it comes to the material conditions and lived experience of people and planet, there’s a limit to our economic and political reasoning, and to conventional architectural practice. That said, I do believe that the mindset of a designer can open up new ways of thinking. At its core, design is an interdisciplinary practice based on the understanding that a problem can’t be solved from a narrow, singular perspective.” 

The stimulating structure of a MAD Fellowship — free from immediate obligations to publish or produce, fellows learn from one another and engage with visiting speakers via regular seminars and events — has prompted Chu to consider what truly makes for generative conversation in the contexts of academia and the private and public sectors. In his opinion, discussions around climate change often fail to take account of one important voice; an absence he describes as “that silent being, the Earth.”

“You can’t ask the Earth, ‘What does justice mean to you?’ Nature will not respond,” he reflects. To bridge the gap, Chu believes it’s important to combine the study of specific political and social conditions with broader existential questions raised by the environmental humanities. His own research draws upon the perspectives of thinkers including Dipesh Chakrabarty, Donna Haraway, Peter Singer,  Anna Tsing, and Michael Watts, among others. He cites James C. Scott’s lecture “In Praise of Floods” as one of his most important influences.

In addition to his instinctive appreciation for theory, Chu’s outlook is grounded by an attention to innovation at the local level. He is currently establishing the parameters of his research, examining case studies of agricultural systems and flood mitigation strategies that have been sustained for centuries. 

“One example is the polder system that is practiced in the Netherlands, China, Bangladesh, and many parts of the world: small, low-lying tracts of land submerged in water and surrounded by dykes and canals,” he explains. “You’ll find a different but comparable strategy in the colder regions of Japan. Crops are protected from the winter winds by constructing a spatial unit with the house at the center; trees behind the house serve as windbreakers and paddy fields for rice are located in front of the house, providing an integrated system of food and livelihood security.”

Chu observes that there is a tendency for international policymakers to overlook local solutions in favor of grander visions and ambitious climate pledges — but he is equally keen not to romanticize vernacular practices. “Realistically, it's always a two-way interaction. Unless you already have a workable local system in place, it’s difficult to implement a solution without top-down support. On the other hand, the large-scale technocratic dreams are empty if ignorant of local traditions and histories.” 

By navigating between the global and the local, the theoretical and the practical, the visionary and the cautionary, Chu has hope in the possibility of gradually finding a way toward long-term solutions that adapt to specific conditions over time. It’s a model of ambition and criticality that Chu sees played out during dialogue at MAD and within his department; at root, he’s aware that the outcome of these conversations depends on the ethical context that shapes them.

“I've been fortunate to have many mentors who have taught me the power of humility; a respect for the finitude, fragility,  and uncertainty of life,” he recalls. “It’s a mindset that’s barely apparent in today’s push for economic growth.” The flip-side of hubristic growth is an assumption that technological ingenuity will be enough to solve the climate crisis, but Chu’s optimism arises from a different source: “When I feel overwhelmed by the weight of the problems we’re facing, I just need to look around me,” he says. “Here on campus — at MAD, in my home department, and increasingly among the new generations of students — there’s a powerful ethos of political sensitivity, ethical compassion, and an attention to clear and critical judgment. That always gives me hope for the planet.”

How free online courses from MIT can “transform the future of the world”

Tue, 03/12/2024 - 5:15pm

From full introductory courses in engineering, psychology, and computer science to lectures about financial concepts, linguistics, and music, the MIT OpenCourseWare YouTube channel has it all — offering millions of learners around the world a pathway to develop new skills and broaden their knowledge base with free offerings from MIT educators.

“I believe OpenCourseWare and Open Learning resources will transform the future of the world for the better — in financial markets I know it already has,” says Michael Pilgreen, a sculptor, painter, and poet from Memphis, Tennessee, who discovered OpenCourseWare when he found himself unemployed in 2020 and used it to jumpstart a new career on Wall Street. 

After watching several lectures about finance, computer science, programming, mathematics, and algorithms on the OpenCourseWare YouTube channel and website, Pilgreen enrolled in the MITx MicroMasters program in finance. He is now a business operations specialist for the Jameel World Education Lab at MIT Open Learning, where he helps the lab bring MIT ideas and know-how to educational innovators worldwide. 

“MIT OpenCourseWare opens the doors to conversations that were previously closed to learners by geography, time, and class,” Pilgreen says. “As an open learner, I was able to leverage the best instructors in the world from my living room, and turn my time being unemployed into a productive period acquiring the skills I needed to work on Wall Street.”

OpenCourseWare is the brainchild of MIT faculty members. The platform was launched in 2001 when the age of digital sharing was just getting started, establishing MIT as the first higher education institution to make educational resources freely available to learners regardless of geographical location or institutional affiliation. Four years later in 2005, OpenCourseWare created a YouTube channel to further its commitment to accessibility and lifelong learning.

Today, OpenCourseWare — part of MIT Open Learning — remains a global model for open sharing in higher education, with an open license that allows the remix and reuse of its educational resources. OpenCourseWare offers materials on its website from more than 2,500 courses that span the MIT undergraduate and graduate curriculum. Educational resources include syllabi, lecture notes, problem sets, assignments, audiovisual content, and insights. 

“We almost take for granted the idea that an enormous amount of outstanding educational content is available to anyone in the world with an internet connection,” says MIT President Sally Kornbluth. “Yet, the fact that this is now the norm has a great deal to do with a groundbreaking project launched at MIT in 2001. OpenCourseWare changed the landscape of education, and it continues to inspire students, teachers, and lifelong learners around the globe to follow their curiosity wherever it leads.”

Curt Newton, OpenCourseWare’s publication director, says the platform inspires millions of curious and motivated learners every year. With over 5 million subscribers and 430 million views, OpenCourseWare stands out as the largest .edu YouTube channel. The channel opens a window into MIT classrooms, giving learners the opportunity to pursue their interests, develop new skills, and even switch careers.

“Videos on our YouTube channel have proven to be an especially effective meeting place,” Newton says. “From introductions to computer programming and the human brain to what it's like to pilot an advanced jet aircraft, these videos are both a complete learning experience in themselves and an entry into even more expansive worlds of learning found on the OpenCourseWare website.”

Emmanuel Kasigazi, an entrepreneur from Uganda, turned to YouTube during the Covid-19 lockdowns and found hundreds of complete lectures on the OpenCourseWare YouTube channel. He explored psychology, cloud computing, data science, and artificial intelligence. 

“The channel opened my eyes to something I didn’t know was reachable,” Kasigazi says. “The psychology classes I took are 24 episodes; each episode is around 40 minutes. That’s a season of 'Grey’s Anatomy.' It’s amazing that I could spend the same amount of time on two different things, but one of them would change my life, my mindset, and the other would just give me a small dopamine boost.”

During his learning journey, Kasigazi also gained a community of open learners. He has teamed up with Pilgreen to shine light on the educational adventures of fellow OpenCourseWare learners. The duo is working on a podcast that will launch this fall. 

“From the channel itself you get great value, but then you pull back the curtain and get to meet the people on the OpenCourseWare team, and it’s amazing,” Kasigazi says. “It’s incredible the people I get to talk to — all because I decided to watch something on YouTube. The most impactful thing I've gotten from this channel is the people I’ve met along the way and the things I’m learning.”

While learners get to expand their knowledge base through these free, publicly accessible videos, MIT faculty members preserve their knowledge for generations to come. 

The late professor Patrick Winston's foundational AI lectures have long been popular on OpenCourseWare. His “How to Speak” lecture, published on the OpenCourseWare YouTube channel in 2018, has become the most popular video on the channel with 18 million views. Winston's annual talk, which had long been a revered event for the MIT community, has now helped millions of people improve their speaking abilities — from conversing with someone one-on-one to presenting research to nailing job interviews.

Gilbert Strang, a world-renowned mathematician, was one of the first professors to publish his lectures on OpenCourseWare. Today, his linear algebra courses have received more than 15 million visits on OpenCourseWare’s website and over 34 million views on YouTube. 

Andrea Henshall, a retired major in the U.S. Air Force, credits her academic success to Strang’s lectures on OpenCourseWare — and other MIT open educational resources. Henshall discovered Strang’s videos after struggling during her first semester of her master’s program in aeronautics and astronautics at MIT. By the end of her master’s program, Henshall was getting A's in all her courses. She is now pursuing a PhD at MIT.

Although Strang has recently retired from MIT after 63 years of teaching, his lessons will continue to be available online to learners in every country on Earth.

“Great teaching is timeless, from the insightful teaching of decades past to our newest video series — an introduction to using data to address cultural, social, economic, and policy questions, created by Sara Ellison and Nobel laureate Esther Duflo,” Newton says. “We’re honored to be preserving and sharing this knowledge for generations to come.” 

MIT OpenCourseWare publishes new content regularly on its YouTube channel and website. Brett Paci, OpenCourseWare’s media publication manager, produces the podcast episodes and many of the video lectures published on the YouTube channel. He considers the channel a “gift to the world.”

“It’s very much in the spirit and mission of MIT to contribute to the global collective knowledge and facilitate learning,” Paci says. “It’s a mission we can be proud of.”

Master bladesmith Bob Kramer’s lessons from the school of life

Tue, 03/12/2024 - 5:10pm

The story of Bob Kramer’s career is a wild one, peppered with twists and turns, false starts, and happy accidents. Before gaining renown as one the finest bladesmiths at work today (a bladesmith is an expert at creating knives and other bladed objects), Kramer had enrolled in and dropped out of college, worked as a chef, performed in improvisational theater, and traveled the United States by train as a circus clown.
 
“The main takeaway for me was that this is an incredible adventure,” Kramer said in a special lecture at MIT on Jan. 26. He was talking about his stint under the big top, but Kramer might as well have meant his lifelong quest for excellence, of making things of exceptional quality and passing on his expertise to others.
 
One of just 120 master bladesmiths in the world, Kramer earned the American Bladesmith Society title after years of hand-forging knives from hot steel and then passing a rigorous test — swiping through an inch-thick rope, chopping a two-by-four, and shaving off his own arm hair.
 
Kramer was at MIT for all of January, invited by the Department of Materials Science and Engineering (DMSE) to teach bladesmithing classes during the institute’s Independent Activities Period. Students lucky enough to get a spot — more than 100 people signed up for 18 spots — learned to shape, heat treat, and grind blades in DMSE’s forge and foundry.

Pursuit, and perfection

Although he called his talk “In Pursuit of the Perfect Blade,” Kramer admitted that perfection is unachievable. “You might think that ‘perfect’ is the operative is this sentence, but for me it’s the pursuit,” Kramer said. “I got my master smith rating in 1997, and in many ways that’s like getting your black belt in a martial art. You are just beginning. You are just starting to understand what needs to be done.”
 
He began by displaying pictures of some of his Kramer Knives — blades with intricate patterns that “go all the way through the steel,” one with a gold inlay of a boy riding a fish, a “plug weld,” or metal insert, and another with steel made from the metals found in a meteorite.
 
Kramer traced his life journey back to his childhood in Michigan as the youngest of six; his older brothers and sisters “were looking outwards. They want to move on, they want to begin their lives. And I’m just trying to figure out like how to survive, how to get some chicken off the plate or get a little bit of attention.”
 
So he was “a little bit of a goofball.” In school, Kramer took to wood shop — measuring and cutting materials and making things — rather than reading and writing book reports. Later, in a high school divided into alternative-lifestyle hippies and letter-sweater-wearing jocks, he learned how to juggle, do card tricks, and ride a unicycle.
 
After a short time as a college student at Wayne State University, where he found out he had dyslexia, he was inspired by Robin Lee Graham’s memoir “Dove,” about the author’s voyage in a sloop as a teenager: “This was one of the easiest books for me to read because it was about adventure.”
 
At 19 Kramer left Detroit to travel across the country. “I was now fully responsible for myself,” he said. “And I began to try to figure out, ‘How do I fit in the world?’”
 
His travels took him to Houston, Texas, where he found a job waiting on the wealthy patrons of the Houston Country Club. Later, on a lark, he went to auditions for Ringling Bros. and Barnum and Bailey Circus clowns, got a contract, and went off with the circus for a year, performing all over the country.
 
“I saw another way to make it through the world. So my mind is opening up to all these other possibilities,” Kramer said.
 
He returned to the service industry, this time getting a job in a hotel kitchen in Seattle. Though the chefs he worked with were professionals with excellent credentials, none knew how to sharpen knives. So he decided he would learn. “I learned how to juggle. I’m going to learn how to sharpen a knife,” he said.
 
After some study, he acquired the right skills and the right tools and started a knife-sharpening business, driving a truck around Seattle, Washington, to fish markets, hotels, and restaurants, making blades razor sharp.

“Make a lot of mistakes”

After about five years, he got bored. “I’ve made enough money, but my mind is not stimulated anymore,” he said. Then one day in Blade, a magazine about custom knives, he saw an ad for a two-week bladesmithing class in Arkansas — an experience that forever changed his life.
 
After attending class, smashing coal into high-carbon coke to make steel and hand-forging a 10-inch blade with a 5-inch handle, he was enraptured.
 
“And when I got home from that, I thought, ‘I’m doing this.’ Somehow this is going to be incorporated in my life,” Kramer said.
 
Soon, he stopped driving his knife-sharpening truck and opened a knife shop in downtown Seattle, hand-making knives in an on-site forge. A review in Saveur magazine brought in swift business. After a move to the country, business slowed. Then Kramer got another review, this time in Cook’s Illustrated, on a $400 chef’s knife the publication bought from him.
 
“And they said, the best knife they had ever tested. The phone starts ringing again, and it happens all over again. Great problem to have,” Kramer said.
 
Kramer described how he makes steel for knives: It starts by stacking layer upon layer, then heating that up to 2,350 degrees Fahrenheit (1,288 Celsius) in the forge and hammering the layers together until they bond. It’s a process he has honed over years of trial and error.
 
“Make a lot of mistakes,” he advised the audience. “That’s how you get to know the stuff.”
 
Professor Yet-Ming Chiang, the Kyocera Professor of Ceramics at MIT and one of Kramer’s DMSE hosts, says what sets Kramer apart is his endless curiosity and passion for self-learning.
 
“Bob is not only a craftsman and an artist; he’s an innovator, in the best sense of that word,” Chiang says. “He doesn’t have any fancy university degrees, but he has illustrated throughout his life how to learn on your own.”

Remembering Ken Johnson Jr., MIT DAPER director of communications, promotions, and marketing

Tue, 03/12/2024 - 11:50am

On Feb. 12, the Division of Student Life and MIT lost a valued community member. Ken Johnson Jr., director of communications, promotions, and marketing in the Department of Athletics, Physical Education, and Recreation (DAPER), passed away following complications from a stroke. He was 47 years old.

Johnson’s sports information career spanned 25 years. Prior to working at MIT, he worked at Brown University and was the sports information director at Manhattanville College, the University of Bridgeport, St. Anselm College, and Assumption University. For the last eight years, Johnson has been at MIT, where he loved working with student-athletes and was recognized many times for his contributions to the sports communications profession.

“Ken truly embraced his role in DAPER. He loved working with our student-athletes and coaches. He continuously displayed his commitment to making every team feel special,” says G. Anthony Grant, DAPER department head and director of athletics.

A passion for sports and collegiate athletics

As a Red Sox fan, an avid golfer, a marathon runner, and a lover of all kinds of sports, Johnson was passionate about working with all of MIT’s 33 sports teams — and it showed. He was recently honored by the College Sports Communicators for his 25-year career in the field. Johnson was also the second vice president of the Eastern Athletic Communications Association and the recipient of the 2019 U.S. Track and Field and Cross-Country Coaches Association Excellence in Communications Award for NCAA Division III Track and Field.

Andrew Barlow, associate professor and baseball coach, also admired Johnson’s enthusiasm for his work, adding, “Ken was a true professional and an instant friend for those who had the opportunity to know him. His passion for the sports communication profession and his devotion to all the student-athletes with whom he supported were remarkable. He was a true fan of all our MIT athletic teams and was an integral part of our MIT baseball family.

“All our players will have fond memories of Ken’s reactions when they would try to make him laugh with silly post-game interview antics. All of us coaches will surely miss our post-game ‘debrief’ sessions where Ken would point out all of ‘our potential decision-making mistakes’ that we might have made,” Barlow says.

“He took great pride when Karenna Groff won the NCAA Woman of the Year Award, and he even attended the ceremony in San Antonio, Texas, where she was recognized,” says Grant. “Ken was also ecstatic when our Men’s Cross-Country team won the program’s first Division III NCAA National Championship. He even bought a full-sized replica of the trophy to put in his office.”

A true New Englander

Johnson grew up on Cape Cod and graduated from Dennis Yarmouth Regional High School. He subsequently earned a bachelor of science in sports management from the University of Massachusetts at Amherst. He is survived by his parents, Kenneth and Katherine “Kate” Johnson, his sister Megan Warfield, her husband, Bill, and his beloved nephew Cameron.

Gifts in Johnson’s memory can be made to the Friends of DAPER Fund.

A sprayable gel could make minimally invasive surgeries simpler and safer

Tue, 03/12/2024 - 11:30am

More than 20 million Americans undergo colonoscopy screenings every year, and in many of those cases, doctors end up removing polyps that are 2 cm or larger and require additional care. This procedure has greatly reduced the overall incidence of colon cancer, but not without complications, as patients may experience gastrointestinal bleeding both during and after the procedure.

In hopes of preventing those complications from occurring, researchers at MIT have developed a new gel, GastroShield, that can be sprayed onto the surgical sites through an endoscope. This gel forms a tough but flexible protective layer that serves as a shield for the damaged area. The material prevents delayed bleeding and reinforces the mechanical integrity of the tissue.

“Our tissue-responsive adhesive technology is engineered to interact with the tissue via complimentary covalent and ionic interactions as well as physical interactions to provide prolonged lesion protection over days to prevent complications following polyp removal, and other wounds at risk of bleeding across the gastrointestinal tract,” says Natalie Artzi, a principal research scientist in MIT’s Institute for Medical Engineering and Science, an associate professor of medicine at Harvard Medical School, and the senior author of the paper.

In an animal study, the researchers showed that the GastroShield application integrates seamlessly with current endoscopic procedures, and provides wound protection for three to seven days where it helps tissue to heal following surgery. Artzi and other members of the research team have started a company called BioDevek that now plans to further develop the material for use in humans.

Gonzalo Muñoz Taboada, CEO of BioDevek, and Daniel Dahis, lead scientist at BioDevek, are the lead authors of the study, which appears in the journal Advanced Materials. Elazer Edelman, the Edward J. Poitras Professor in Medical Engineering and Science at MIT and the director of IMES, and Pere Dosta, a former postdoc in Artzi’s lab, are also authors of the paper.

Adhesive gels

Routine colon cancer screenings often reveal small precancerous polyps, which can be removed before they become cancerous. This is usually done using an endoscope. If any bleeding occurs during the polyp removal, doctors can cauterize the wound to seal it, but this method creates a scar that may delay the healing, and result in additional complications.

Additionally, in some patients, bleeding doesn’t occur until a few days after the procedure. This can be dangerous and may require patients to return to the hospital for additional treatment. Other patients may develop small tears that lead the intestinal contents to leak into the abdomen, which can lead to severe infection and requires emergency care.

When tissue reinforcement is required, doctors often insert metal clips to hold tissue together, but these can’t be used with larger polyps and aren’t always effective. Efforts to develop a gel that could seal the surgical wounds have not been successful, mainly because the materials could not adhere to the surgical site for more than 24 hours.

The MIT team tested dozens of combinations of materials that they thought could have the right properties for this use. They wanted to find formulations that would display a low enough viscosity to be easily delivered and sprayed through a nozzle at the end of a catheter that fits inside commercial endoscopes. Simultaneously, upon tissue contact, this formulation should instantly form a tough gel that adheres strongly to the tissue. They also wanted the gel to be flexible enough that it could withstand the forces generated by the peristaltic movements of the digestive tract and the food flowing by.

The researchers came up with a winning combination that includes a polymer called pluronic, which is a type of block copolymer that can self-assemble into spheres called micelles. The ends of these polymers contain multiple amine groups, which end up on the surface of the micelles. The second component of the gel is oxidized dextran, a polysaccharide that can form strong but reversible bonds with the amine groups of the pluronic micelles.

When sprayed, these materials instantly react with each other and with the lining of the gastrointestinal tract, forming a solid gel in less than five seconds. The micelles that make up the gel are “self-healing” and can absorb forces that they encounter from peristaltic movements and food moving along the digestive tract, by temporarily breaking apart and then re-assembling.

“To obtain a material that adheres to the design criteria and can be delivered through existing colonoscopes, we screened through libraries of materials to understand how different parameters affect gelation, adhesion, retention, and compatibility,” Artzi says.

A protective layer

The gel can also withstand the low pH and enzymatic activity in the digestive tract, and protect tissue from that harsh environment while it heals itself, underscoring its potential for use in other gastrointestinal wounds at high risk of bleeding, such as  stomach ulcers, which affect more than 4 million Americans every year.

In tests in animals, the researchers found that every animal treated with the new gel showed rapid sealing, and there were no perforations, leakages, or bleeding in the week following the treatment. The material lasted for about five days, after which it was sloughed off along with the top layer of tissue as the surgical wounds healed.

The researchers also performed several biocompatibility studies and found that the gel did not cause any adverse effects.

“A key feature of this new technology is our aim to make it translational. GastroShield was designed to be stored in liquid form in a ready-to-use kit. Additionally, it doesn’t require any activation, light, or trigger solution to form the gel, aiming to make endoscopic use easy and fast,” says Muñoz, who is currently leading the translational effort for GastroShield.

BioDevek is now working on further developing the material for possible use in patients. In addition to its potential use in colonoscopies, this gel could also be useful for treating stomach ulcers and inflammatory conditions such as Crohn’s disease, or for delivering cancer drugs, Artzi says.

The research was funded, in part, by the National Science Foundation.

Boosting student engagement and workforce development in microelectronics

Tue, 03/12/2024 - 9:45am

The Northeast Microelectronics Internship Program (NMIP), an initiative of MIT’s Microsystems Technology Laboratories (MTL) to connect first- and second-year college students to careers in semiconductor and microelectronics industries, recently received a $75,000 grant to expand its reach and impact. The funding is part of $9.2 million in grants awarded by the Northeast Microelectronics Coalition (NEMC) Hub to boost technology advancement, workforce development, education, and student engagement across the Northeast Region.

NMIP was founded by Tomás Palacios, the Clarence J. LeBel Professor of Electrical Engineering at MIT, and director of MTL. The grant, he says, will help address a significant barrier limiting the number of students who pursue careers in critical technological fields.

“Undergraduate students are key for the future of our nation’s microelectronics workforce. They directly fill important roles that require technical fluency or move on to advanced degrees,” says Palacios. “But these students have repeatedly shared with us that the lack of internships in their first few semesters in college is the main reason why many move to industries with a more established tradition of hiring undergraduate students in their early years. This program connects students and industry partners to fix this issue.”

The NMIP funding was announced on Jan. 30 during an event featuring Massachusetts Governor Maura Healey, Lt. Governor Kim Driscoll, and Economic Development Secretary Yvonne Hao, as well as leaders from the U.S. Department of Defense and the director of Microelectronics Commons at NSTXL, the National Security Technology Accelerator. The grant to support NMIP is part of $1.5 million in new workforce development grants aimed at spurring the microelectronics and semiconductor industry across the Northeast Region. The new awards are the first investments made by the NEMC Hub, a division of the Massachusetts Technology Collaborative, that is overseeing investments made by the federal CHIPS and Science Act following the formal establishment of the NEMC Hub in September 2023.

“We are very excited for the recognition the program is receiving. It is growing quickly and the support will help us further dive into our mission to connect talented students to the broader microelectronics ecosystem while integrating our values of curiosity, openness, excellence, respect, and community,” says Preetha Kingsview, who manages the program. “This grant will help us connect to the broader community convened by NEMC Hub in close collaboration with MassTech. We are very excited for what this support will help NMIP achieve.”

The funds provided by the NEMC Microelectronics Commons Hub will help expand the program more broadly across the Northeast, to support students and grow the pool of skilled workers for the microelectronics sector regionally. After receiving 300 applications in the first two years, the program received 296 applications in 2024 from students interested in summer internships, and is working with more than 25 industry partners across the Northeast. These NMIP students not only participate in industry-focused summer internships, but are also exposed to the broader microelectronics ecosystem through bi-weekly field trips to microelectronics companies in the region.

“The expansion of the program across the Northeast, and potentially nationwide, will extend the impact of this program to reach more students and benefit more microelectronics companies across the region,” says Christine Nolan, acting NEMC Hub program director.Through hands-on training opportunities we are able to showcase the amazing jobs that exist in this sector and to strengthen the pipeline of talented workers to support the mission of the NEMC Hub and the national CHIPs investments.”  

Sheila Wescott says her company, MACOM, a Lowell-based developer of semiconductor devices and components, is keenly interested in sourcing intern candidates from NMIP. “We already have a success story from this program,” she says. “One of our interns completed two summer programs with us and is continuing part time in the fall — and we anticipate him joining MACOM full time after graduation.”

“NMIP is an excellent platform to engage students with a diverse background and promote microelectronics technology,” says Bin Lu, CTO and co-founder of Finwave Semiconductor.  “Finwave has benefited from engaging with the young engineers who are passionate about working with electronics and cutting-edge semiconductor technology. We are committed to continuing to work with NMIP.”

Scientists develop a rapid gene-editing screen to find effects of cancer mutations

Tue, 03/12/2024 - 6:00am

Tumors can carry mutations in hundreds of different genes, and each of those genes may be mutated in different ways — some mutations simply replace one DNA nucleotide with another, while others insert or delete larger sections of DNA.

Until now, there has been no way to quickly and easily screen each of those mutations in their natural setting to see what role they may play in the development, progression, and treatment response of a tumor. Using a variant of CRISPR genome-editing known as prime editing, MIT researchers have now come up with a way to screen those mutations much more easily.

The researchers demonstrated their technique by screening cells with more than 1,000 different mutations of the tumor suppressor gene p53, all of which have been seen in cancer patients. This method, which is easier and faster than any existing approach, and edits the genome rather than introducing an artificial version of the mutant gene, revealed that some p53 mutations are more harmful than previously thought.

This technique could also be applied to many other cancer genes, the researchers say, and could eventually be used for precision medicine, to determine how an individual patient’s tumor will respond to a particular treatment.

“In one experiment, you can generate thousands of genotypes that are seen in cancer patients, and immediately test whether one or more of those genotypes are sensitive or resistant to any type of therapy that you’re interested in using,” says Francisco Sanchez-Rivera, an MIT assistant professor of biology, a member of the Koch Institute for Integrative Cancer Research, and the senior author of the study.

MIT graduate student Samuel Gould is the lead author of the paper, which appears today in Nature Biotechnology.

Editing cells

The new technique builds on research that Sanchez-Rivera began 10 years ago as an MIT graduate student. At that time, working with Tyler Jacks, the David H. Koch Professor of Biology, and then-postdoc Thales Papagiannakopoulos, Sanchez-Rivera developed a way to use CRISPR genome-editing to introduce into mice genetic mutations linked to lung cancer.

In that study, the researchers showed that they could delete genes that are often lost in lung tumor cells, and the resulting tumors were similar to naturally arising tumors with those mutations. However, this technique did not allow for the creation of point mutations (substitutions of one nucleotide for another) or insertions.

“While some cancer patients have deletions in certain genes, the vast majority of mutations that cancer patients have in their tumors also include point mutations or small insertions,” Sanchez-Rivera says.

Since then, David Liu, a professor in the Harvard University Department of Chemistry and Chemical Biology and a core institute member of the Broad Institute, has developed new CRISPR-based genome editing technologies that can generate additional types of mutations more easily. With base editing, developed in 2016, researchers can engineer point mutations, but not all possible point mutations. In 2019, Liu, who is also an author of the Nature Biotechnology study, developed a technique called prime editing, which enables any kind of point mutation to be introduced, as well as insertions and deletions.

“Prime editing in theory solves one of the major challenges with earlier forms of CRISPR-based editing, which is that it allows you to engineer virtually any type of mutation,” Sanchez-Rivera says.

When they began working on this project, Sanchez-Rivera and Gould calculated that if performed successfully, prime editing could be used to generate more than 99 percent of all small mutations seen in cancer patients.

However, to achieve that, they needed to find a way to optimize the editing efficiency of the CRISPR-based system. The prime editing guide RNAs (pegRNAs) used to direct CRISPR enzymes to cut the genome in certain spots have varying levels of efficiency, which leads to “noise” in the data from pegRNAs that simply aren’t generating the correct target mutation. The MIT team devised a way to reduce that noise by using synthetic target sites to help them calculate how efficiently each guide RNA that they tested was working.

“We can design multiple prime-editing guide RNAs with different design properties, and then we get an empirical measurement of how efficient each of those pegRNAs is. It tells us what percentage of the time each pegRNA is actually introducing the correct edit,” Gould says.

Analyzing mutations

The researchers demonstrated their technique using p53, a gene that is mutated in more than half of all cancer patients. From a dataset that includes sequencing information from more than 40,000 patients, the researchers identified more than 1,000 different mutations that can occur in p53.

“We wanted to focus on p53 because it’s the most commonly mutated gene in human cancers, but only the most frequent variants in p53 have really been deeply studied. There are many variants in p53 that remain understudied,” Gould says.

Using their new method, the researchers introduced p53 mutations in human lung adenocarcinoma cells, then measured the survival rates of these cells, allowing them to determine each mutation’s effect on cell fitness.

Among their findings, they showed that some p53 mutations promoted cell growth more than had been previously thought. These mutations, which prevent the p53 protein from forming a tetramer — an assembly of four p53 proteins — had been studied before, using a technique that involves inserting artificial copies of a mutated p53 gene into a cell.

Those studies found that these mutations did not confer any survival advantage to cancer cells. However, when the MIT team introduced those same mutations using the new prime editing technique, they found that the mutation prevented the tetramer from forming, allowing the cells to survive. Based on the studies done using overexpression of artificial p53 DNA, those mutations would have been classified as benign, while the new work shows that under more natural circumstances, they are not.

“This is a case where you could only observe these variant-induced phenotypes if you're engineering the variants in their natural context and not with these more artificial systems,” Gould says. “This is just one example, but it speaks to a broader principle that we’re going to be able to access novel biology using these new genome-editing technologies.”

Because it is difficult to reactivate tumor suppressor genes, there are few drugs that target p53, but the researchers now plan to investigate mutations found in other cancer-linked genes, in hopes of discovering potential cancer therapies that could target those mutations. They also hope that the technique could one day enable personalized approaches to treating tumors.

“With the advent of sequencing technologies in the clinic, we'll be able to use this genetic information to tailor therapies for patients suffering from tumors that have a defined genetic makeup,” Sanchez-Rivera says. “This approach based on prime editing has the potential to change everything.”

The research was funded, in part, by the National Institute of General Medical Sciences, an MIT School of Science Fellowship in Cancer Research, a Howard Hughes Medical Institute Hanna Gray Fellowship, the V Foundation for Cancer Research, a National Cancer Institute Cancer Center Support Grant, the Ludwig Center at MIT, a Koch Institute Frontier Award, the MIT Research Support Committee, and the Koch Institute Support (core) Grant from the National Cancer Institute.

Reducing pesticide use while increasing effectiveness

Tue, 03/12/2024 - 12:00am

Farming can be a low-margin, high-risk business, subject to weather and climate patterns, insect population cycles, and other unpredictable factors. Farmers need to be savvy managers of the many resources they deal, and chemical fertilizers and pesticides are among their major recurring expenses.

Despite the importance of these chemicals, a lack of technology that monitors and optimizes sprays has forced farmers to rely on personal experience and rules of thumb to decide how to apply these chemicals. As a result, these chemicals tend to be over-sprayed, leading to their runoff into waterways and buildup up in the soil.

That could change, thanks to a new approach of feedback-optimized spraying, invented by AgZen, an MIT spinout founded in 2020 by Professor Kripa Varanasi and Vishnu Jayaprakash SM ’19, PhD ’22.

Over the past decade, AgZen’s founders have developed products and technologies to control the interactions of droplets and sprays with plant surfaces. The Boston-based venture-backed company launched a new commercial product in 2024 and is currently piloting another related product. Field tests of both have shown the products can help farmers spray more efficiently and effectively, using fewer chemicals overall.

“Worldwide, farms spend approximately $60 billion a year on pesticides. Our objective is to reduce the number of pesticides sprayed and lighten the financial burden on farms without sacrificing effective pest management,” Varanasi says.

Getting droplets to stick

While the world pesticide market is growing rapidly, a lot of the pesticides sprayed don’t reach their target. A significant portion bounces off the plant surfaces, lands on the ground, and becomes part of the runoff that flows to streams and rivers, often causing serious pollution. Some of these pesticides can be carried away by wind over very long distances.

“Drift, runoff, and poor application efficiency are well-known, longstanding problems in agriculture, but we can fix this by controlling and monitoring how sprayed droplets interact with leaves,” Varanasi says.

With support from MIT Tata Center and the Abdul Latif Jameel Water and Food Systems Lab, Varanasi and his team analyzed how droplets strike plant surfaces, and explored ways to increase application efficiency. This research led them to develop a novel system of nozzles that cloak droplets with compounds that enhance the retention of droplets on the leaves, a product they call EnhanceCoverage.

Field studies across regions — from Massachusetts to California to Italy and France —showed that this droplet-optimization system could allow farmers to cut the amount of chemicals needed by more than half because more of the sprayed substances would stick to the leaves.

Measuring coverage

However, in trying to bring this technology to market, the researchers faced a sticky problem: Nobody knew how well pesticide sprays were adhering to the plants in the first place, so how could AgZen say that the coverage was better with its new EnhanceCoverage system?

“I had grown up spraying with a backpack on a small farm in India, so I knew this was an issue,” Jayaprakash says. “When we spoke to growers, they told me how complicated spraying is when you’re on a large machine. Whenever you spray, there are so many things that can influence how effective your spray is. How fast do you drive the sprayer? What flow rate are you using for the chemicals? What chemical are you using? What’s the age of the plants, what’s the nozzle you’re using, what is the weather at the time? All these things influence agrochemical efficiency.”

Agricultural spraying essentially comes down to dissolving a chemical in water and then spraying droplets onto the plants. “But the interaction between a droplet and the leaf is complex,” Varanasi says. “We were coming in with ways to optimize that, but what the growers told us is, hey, we’ve never even really looked at that in the first place.”

Although farmers have been spraying agricultural chemicals on a large scale for about 80 years, they’ve “been forced to rely on general rules of thumb and pick all these interlinked parameters, based on what’s worked for them in the past. You pick a set of these parameters, you go spray, and you’re basically praying for outcomes in terms of how effective your pest control is,” Varanasi says.

Before AgZen could sell farmers on the new system to improve droplet coverage, the company had to invent a way to measure precisely how much spray was adhering to plants in real-time.

Comparing before and after

The system they came up with, which they tested extensively on farms across the country last year, involves a unit that can be bolted onto the spraying arm of virtually any sprayer. It carries two sensor stacks, one just ahead of the sprayer nozzles and one behind. Then, built-in software running on a tablet shows the operator exactly how much of each leaf has been covered by the spray. It also computes how much those droplets will spread out or evaporate, leading to a precise estimate of the final coverage.

“There’s a lot of physics that governs how droplets spread and evaporate, and this has been incorporated into software that a farmer can use,” Varanasi says. “We bring a lot of our expertise into understanding droplets on leaves. All these factors, like how temperature and humidity influence coverage, have always been nebulous in the spraying world. But now you have something that can be exact in determining how well your sprays are doing.”

“We’re not only measuring coverage, but then we recommend how to act,” says Jayaprakash, who is AgZen’s CEO. “With the information we collect in real-time and by using AI, RealCoverage tells operators how to optimize everything on their sprayer, from which nozzle to use, to how fast to drive, to how many gallons of spray is best for a particular chemical mix on a particular acre of a crop.”

The tool was developed to prove how much AgZen’s EnhanceCoverage nozzle system (which will be launched in 2025) improves coverage. But it turns out that monitoring and optimizing droplet coverage on leaves in real-time with this system can itself yield major improvements.

“We worked with large commercial farms last year in specialty and row crops,” Jayaprakash says. “When we saved our pilot customers up to 50 percent of their chemical cost at a large scale, they were very surprised.” He says the tool has reduced chemical costs and volume in fallow field burndowns, weed control in soybeans, defoliation in cotton, and fungicide and insecticide sprays in vegetables and fruits. Along with data from commercial farms, field trials conducted by three leading agricultural universities have also validated these results.

“Across the board, we were able to save between 30 and 50 percent on chemical costs and increase crop yields by enabling better pest control,” Jayaprakash says. “By focusing on the droplet-leaf interface, our product can help any foliage spray throughout the year, whereas most technological advancements in this space recently have been focused on reducing herbicide use alone.” The company now intends to lease the system across thousands of acres this year.

And these efficiency gains can lead to significant returns at scale, he emphasizes: In the U.S., farmers currently spend $16 billion a year on chemicals, to protect about $200 billion of crop yields.

The company launched its first product, the coverage optimization system called RealCoverage, this year, reaching a wide variety of farms with different crops and in different climates. “We’re going from proof-of-concept with pilots in large farms to a truly massive scale on a commercial basis with our lease-to-own program,” Jayaprakash says.

“We’ve also been tapped by the USDA to help them evaluate practices to minimize pesticides in watersheds,” Varanasi says, noting that RealCoverage can also be useful for regulators, chemical companies, and agricultural equipment manufacturers.

Once AgZen has proven the effectiveness of using coverage as a decision metric, and after the RealCoverage optimization system is widely in practice, the company will next roll out its second product, EnhanceCoverage, designed to maximize droplet adhesion. Because that system will require replacing all the nozzles on a sprayer, the researchers are doing pilots this year but will wait for a full rollout in 2025, after farmers have gained experience and confidence with their initial product.

“There is so much wastage,” Varanasi says. “Yet farmers must spray to protect crops, and there is a lot of environmental impact from this. So, after all this work over the years, learning about how droplets stick to surfaces and so on, now the culmination of it in all these products for me is amazing, to see all this come alive, to see that we’ll finally be able to solve the problem we set out to solve and help farmers.”

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