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School of Engineering first quarter 2021 awards

Fri, 03/19/2021 - 4:00pm

Members of the MIT engineering faculty receive many awards in recognition of their scholarship, service, and overall excellence. The School of Engineering periodically recognizes their achievements by highlighting the honors, prizes, and medals won by faculty working in our academic departments, labs, and centers.

Vaccination by inhalation

Fri, 03/19/2021 - 2:00pm

Many viruses infect their hosts through mucosal surfaces such as the lining of the respiratory tract. MIT researchers have now developed a vaccination strategy that can create an army of T cells that are ready and waiting at those surfaces, offering a quicker response to viral invaders.

The researchers showed that they could induce a strong memory T cell response in the lungs of mice by giving them a vaccine modified to bind to a protein naturally present in mucus. This can help ferry the vaccine across mucosal barriers, such as the lining of the lungs.

“In this paper, we specifically focused on T cell responses that would be useful against viruses or cancer, and our idea was to use this protein, albumin, as sort of a Trojan horse to get the vaccine across the mucosal barrier,” says Darrell Irvine, the senior author of the study, who is the Underwood-Prescott Professor with appointments in the departments of Biological Engineering and Materials Science and Engineering; an associate director of MIT’s Koch Institute for Integrative Cancer Research; and a member of the Ragon Institute of MGH, MIT, and Harvard.

In addition to protecting against pathogens that infect the lungs, these types of inhaled vaccines could also be used to treat cancer metastasizing to the lungs or even prevent cancer from developing in the first place, the researchers say.

Former MIT postdoc Kavya Rakhra is the lead author of the study, which appears today in Science Immunology. Other authors include technical associates Wuhbet Abraham and Na Li, postdoc Chensu Wang, former graduate student Kelly Moynihan PhD ’17, and former research technicians Nathan Donahue and Alexis Baldeon.

Local response

Most vaccines are given as an injection into the muscle tissue. However, most viral infections occur at mucosal surfaces such as the lungs and upper respiratory tract, reproductive tract, or gastrointestinal tract. Creating a strong line of defense at those sites could help the body fend off infection more effectively, Irvine says.

“In some cases, vaccines given in muscle can elicit immunity at mucosal surfaces, but there is a general principle that if you vaccinate through the mucosal surface, you tend to elicit a stronger protection at that site,” Irvine says. “Unfortunately, we don’t have great technologies yet for mounting immune responses that specifically protect those mucosal surfaces.”

There is an approved nasal vaccine for the flu, and an oral vaccine for typhoid, but both of those vaccines consist of live, attenuated viruses, which are better able to cross mucosal barriers. Irvine’s lab wanted to pursue an alternative: peptide vaccines, which have a better safety profile and are easier to manufacture, but are more difficult to get across mucosal barriers.

To try to make peptide vaccines easier to deliver to the lungs, the researchers turned to an approach they first explored in a 2014 study. In that paper, Irvine and his colleagues found that attaching peptide vaccines to albumin proteins, found in the bloodstream, helped the peptides to accumulate in the lymph nodes, where they could activate a strong T cell response.

Those vaccines were given by injection, like most traditional vaccines. In their new study, the researchers investigated whether albumin could also help peptide vaccines get across mucosal barriers such as those surrounding the lungs. One of albumin’s functions is to help maintain osmotic pressure in the lungs, and it can easily pass through the epithelial tissue surrounding the lungs.

To test this idea, the researchers attached an albumin-binding lipid tail to a peptide vaccine against the vaccinia virus. The vaccine also included a commonly used adjuvant called CpG, which helps to provoke a stronger immune response.

The vaccine was delivered intratracheally, which simulates inhalation exposure. The researchers found that this type of delivery generated a 25-fold increase in memory T cells in the mouse lungs, compared to injecting the albumin-modified vaccine into a muscle site far from the lungs. They also showed that when mice were exposed to the vaccinia virus months later, the intramuscular vaccine offered no protection, while all of the animals that received the vaccine intratracheally were protected.

Targeting tumors

The researchers also tested a mucosal vaccine against cancer. In that case, they used a peptide found on melanoma cells to immunize mice. When the vaccinated mice were exposed to metastatic melanoma cells, T cells in the lungs were able to eliminate them. The researchers also showed that the vaccine could help to shrink existing lung tumors.

This kind of local response could make it possible to develop vaccines that would prevent tumors from forming in specific organs, by targeting antigens commonly found on tumor cells.

“In both the virus and the tumor experiments, we’re leveraging this idea that, as other people have shown, these memory T cells set up shop in the lungs and are waiting right there at the barrier. As soon as a tumor cell shows up, or as soon as a virus infects the target cell, the T cells can immediately clear it,” Irvine says.

This strategy could also be useful for creating mucosal vaccines against other viruses such as HIV, influenza, or SAR-CoV-2, Irvine says. His lab is now using the same approach to create a vaccine that provokes a strong antibody response in the lungs, using SARS-CoV-2 as a target.

The research was funded by the Bridge Project of the Koch Institute and the Dana-Farber/Harvard Cancer Center; the Marble Center for Cancer Nanomedicine; the Ragon Institute of MGH, MIT, and Harvard; and the National Institutes of Health.

System detects errors when medication is self-administered

Thu, 03/18/2021 - 2:00pm

From swallowing pills to injecting insulin, patients frequently administer their own medication. But they don’t always get it right. Improper adherence to doctors’ orders is commonplace, accounting for thousands of deaths and billions of dollars in medical costs annually. MIT researchers have developed a system to reduce those numbers for some types of medications.

The new technology pairs wireless sensing with artificial intelligence to determine when a patient is using an insulin pen or inhaler, and flags potential errors in the patient’s administration method. “Some past work reports that up to 70% of patients do not take their insulin as prescribed, and many patients do not use inhalers properly,” says Dina Katabi, the Andrew and Erna Viteri Professor at MIT, whose research group has developed the new solution. The researchers say the system, which can be installed in a home, could alert patients and caregivers to medication errors and potentially reduce unnecessary hospital visits.

The research appears today in the journal Nature Medicine. The study’s lead authors are Mingmin Zhao, a PhD student in MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL), and Kreshnik Hoti, a former visiting scientist at MIT and current faculty member at the University of Prishtina in Kosovo. Other co-authors include Hao Wang, a former CSAIL postdoc and current faculty member at Rutgers University, and Aniruddh Raghu, a CSAIL PhD student.

Some common drugs entail intricate delivery mechanisms. “For example, insulin pens require priming to make sure there are no air bubbles inside. And after injection, you have to hold for 10 seconds,” says Zhao. “All those little steps are necessary to properly deliver the drug to its active site.” Each step also presents opportunity for errors, especially when there’s no pharmacist present to offer corrective tips. Patients might not even realize when they make a mistake — so Zhao’s team designed an automated system that can.

Their system can be broken down into three broad steps. First, a sensor tracks a patient’s movements within a 10-meter radius, using radio waves that reflect off their body. Next, artificial intelligence scours the reflected signals for signs of a patient self-administering an inhaler or insulin pen. Finally, the system alerts the patient or their health care provider when it detects an error in the patient’s self-administration.

The researchers adapted their sensing method from a wireless technology they’d previously used to monitor people’s sleeping positions. It starts with a wall-mounted device that emits very low-power radio waves. When someone moves, they modulate the signal and reflect it back to the device’s sensor. Each unique movement yields a corresponding pattern of modulated radio waves that the device can decode. “One nice thing about this system is that it doesn’t require the patient to wear any sensors,” says Zhao. “It can even work through occlusions, similar to how you can access your Wi-Fi when you’re in a different room from your router.”

The new sensor sits in the background at home, like a Wi-Fi router, and uses artificial intelligence to interpret the modulated radio waves. The team developed a neural network to key in on patterns indicating the use of an inhaler or insulin pen. They trained the network to learn those patterns by performing example movements, some relevant (e.g. using an inhaler) and some not (e.g. eating). Through repetition and reinforcement, the network successfully detected 96 percent of insulin pen administrations and 99 percent of inhaler uses.

Once it mastered the art of detection, the network also proved useful for correction. Every proper medicine administration follows a similar sequence — picking up the insulin pen, priming it, injecting, etc. So, the system can flag anomalies in any particular step. For example, the network can recognize if a patient holds down their insulin pen for five seconds instead of the prescribed 10 seconds. The system can then relay that information to the patient or directly to their doctor, so they can fix their technique.

“By breaking it down into these steps, we can not only see how frequently the patient is using their device, but also assess their administration technique to see how well they’re doing,” says Zhao.

The researchers say a key feature of their radio wave-based system is its noninvasiveness. “An alternative way to solve this problem is by installing cameras,” says Zhao. “But using a wireless signal is much less intrusive. It doesn’t show peoples’ appearance.”

He adds that their framework could be adapted to medications beyond inhalers and insulin pens — all it would take is retraining the neural network to recognize the appropriate sequence of movements. Zhao says that “with this type of sensing technology at home, we could detect issues early on, so the person can see a doctor before the problem is exacerbated.”

Found in space: Complex carbon-based molecules

Thu, 03/18/2021 - 2:00pm

Much of the carbon in space is believed to exist in the form of large molecules called polycyclic aromatic hydrocarbons (PAHs). Since the 1980s, circumstantial evidence has indicated that these molecules are abundant in space, but they have not been directly observed.

Now, a team of researchers led by MIT Assistant Professor Brett McGuire has identified two distinctive PAHs in a patch of space called the Taurus Molecular Cloud (TMC-1). PAHs were believed to form efficiently only at high temperatures — on Earth, they occur as byproducts of burning fossil fuels, and they’re also found in char marks on grilled food. But the interstellar cloud where the research team observed them has not yet started forming stars, and the temperature is about 10 degrees above absolute zero.

This discovery suggests that these molecules can form at much lower temperatures than expected, and it may lead scientists to rethink their assumptions about the role of PAH chemistry in the formation of stars and planets, the researchers say.

“What makes the detection so important is that not only have we confirmed a hypothesis that has been 30 years in the making, but now we can look at all of the other molecules in this one source and ask how they are reacting to form the PAHs we’re seeing, how the PAHs we’re seeing may react with other things to possibly form larger molecules, and what implications that may have for our understanding of the role of very large carbon molecules in forming planets and stars,” says McGuire, who is a senior author of the new study.

Michael McCarthy, associate director of the Harvard-Smithsonian Center for Astrophysics, is another senior author of the study, which appears today in Science. The research team also includes scientists from several other institutions, including the University of Virginia, the National Radio Astronomy Observatory, and NASA’s Goddard Space Flight Center.

Distinctive signals

Starting in the 1980s, astronomers have used telescopes to detect infrared signals that suggested the presence of aromatic molecules, which are molecules that typically include one or more carbon rings. About 10 to 25 percent of the carbon in space is believed to be found in PAHs, which contain at least two carbon rings, but the infrared signals weren’t distinct enough to identify specific molecules.

“That means that we can’t dig into the detailed chemical mechanisms for how these are formed, how they react with one another or other molecules, how they’re destroyed, and the whole cycle of carbon throughout the process of forming stars and planets and eventually life,” McGuire says.

Although radio astronomy has been a workhorse of molecular discovery in space since the 1960s, radio telescopes powerful enough to detect these large molecules have only been around for a little over a decade. These telescopes can pick up molecules’ rotational spectra, which are distinctive patterns of light that molecules give off as they tumble through space. Researchers can then try to match patterns observed in space with patterns that they have seen from those same molecules in laboratories on Earth.

“Once you have that pattern match, you know there is no other molecule in existence that could be giving off that exact spectrum. And, the intensity of the lines and the relative strength of the different pieces of the pattern tells you something about how much of the molecule there is, and how warm or cold the molecule is,” McGuire says.

McGuire and his colleagues have been studying TMC-1 for several years because previous observations have revealed it to be rich in complex carbon molecules. A few years ago, one member of the research team observed hints that the cloud contain benzonitrile — a six-carbon ring attached to a nitrile (carbon-nitrogen) group.

The researchers then used the Green Bank Telescope, the world’s largest steerable radio telescope, to confirm the presence of benzonitrile. In their data, they also found signatures of two other molecules — the PAHs reported in this study. Those molecules, called 1-cyanonaphthalene and 2-cyanonaphthalene, consist of two benzene rings fused together, with a nitrile group attached to one ring.

“Detecting these molecules is a major leap forward in astrochemistry. We are beginning to connect the dots between small molecules — like benzonitrile — that have been known to exist in space, to the monolithic PAHs that are so important in astrophysics,” says Kelvin Lee, an MIT postdoc who is one of the authors of the study.

Finding these molecules in the cold, starless TMC-1 suggests that PAHs are not just the byproducts of dying stars, but may be assembled from smaller molecules.

“In the place where we found them, there is no star, so either they’re being built up in place or they are the leftovers of a dead star,” McGuire says. “We think that it’s probably a combination of the two — the evidence suggests that it is neither one pathway nor the other exclusively. That’s new and interesting because there really hadn’t been any observational evidence for this bottom-up pathway before.”

Carbon chemistry

Carbon plays a critical role in the formation of planets, so the suggestion that PAHs might be present even in starless, cold regions of space, may prompt scientists to rethink their theories of what chemicals are available during planet formation, McGuire says. As PAHs react with other molecules, they may start to form interstellar dust grains, which are the seeds of asteroids and planets.

“We need to entirely rethink our models of how the chemistry is evolving, starting from these starless cores, to include the fact that they are forming these large aromatic molecules,” he says.

McGuire and his colleagues now plan to further investigate how these PAHs formed, and what kinds of reactions they may undergo in space. They also plan to continue scanning TMC-1 with the powerful Green Bank Telescope. Once they have those observations from the interstellar cloud, the researchers can try to match up the signatures they find with data that they generate on Earth by putting two molecules into a reactor and blasting them with kilovolts of electricity, breaking them into bits and letting them recombine. This could result in hundreds of different molecules, many of which have never been seen on Earth.

“We need to continue to see what molecules are present in this interstellar source, because the more we know about the inventory, the more we can start trying to connect the pieces of this reaction web,” McGuire says.

The research was funded by NASA, the Smithsonian Institute, the National Science Foundation, the Alexander von Humboldt Foundation, and the European Union’s Horizon 2020 research and innovation program.

At MIT Energy Conference, experts zero in on legacy energy systems

Thu, 03/18/2021 - 12:00pm

Global power generation from renewables like solar and wind continues to rise, and innovation in fields like clean hydrogen production and nuclear fusion is thriving. But translating all that progress into lower global emissions will require major changes to legacy energy systems around the world. That was the most discussed challenge among speakers at this year’s MIT Energy Conference, hosted virtually last week by the MIT Energy Club.

In some cases, energy systems can be adapted to integrate new power sources. In others, entirely new systems will have to be constructed to get power to people when they need it.

“There’s an equilibrium between technology, policy, and infrastructure, and they all depend on each other,” explained panelist Vijay Swarup, the vice president of research and development at ExxonMobil.

Many presenters began by acknowledging the huge strides solar and wind energy have made in terms of price and deployments over the last decade. In the event’s first keynote, George Bilicic of the global financial services firm Lazard presented his firm’s analysis on the cost of various energy sources, showing large-scale deployments of renewables are cost competitive with coal and gas in many circumstances.

But incorporating variable energy sources like solar and wind into the grid can be difficult, both economically and technically. New systems are needed to better integrate such energy sources into existing infrastructure, speakers said.

“I see digital services as a critical enabler of [clean energy] technologies, because there’s a lot more real-time management required when you’re dealing with a proliferation of energy solutions,” said Shell Energy Americas Senior Vice President Carolyn Comer, adding that Shell is developing new businesses models to harness more wind and solar energy. “The ability to switch [energy streams] on and off in a way that keeps the grid stable is critically important.”

Grid stability was top of mind for many participants in the wake of the February storms in Texas, which resulted in an energy crisis that left 4.5 million homes and businesses without power. Although the causes of the system failures are still being investigated, multiple speakers voiced frustration that renewables were quickly blamed for a disaster in which energy from natural gas was also disrupted and the grid experienced broad failures.

Speaking from San Antonio, Anthony Dorazio of Avangrid Renewables noted that in a future where extreme weather events are more common, grid resiliency needs to be a top priority.

“It’s not how we design a perfect system, because we’ll never design a perfect system,” Dorazio said. “It’s how we react to the changing environment. We need to look at digitization, we need information to move much quicker, we need to use forecasting tools to manage these changes as they approach. When you look at what happened in Texas, in the end we’ll all learn from it. We’ll be better and stronger, and figure out better systems as a result.”

The March 10-12 event, which featured talks by energy industry executives, startup founders, investors, and current and former government officials, is the largest, student-run clean energy conference in the world, according to conference co-organizer Trevor Thompson, an MBA candidate at the MIT Sloan School of Management.

The 16th annual conference was also the first to include a panel on climate justice, where attendees heard from members of communities that have been disproportionately affected by fossil fuel emissions and pollution.

As part of that panel, Jacqueline Patterson, the senior director of the NAACP Environmental and Climate Justice Program, talked about observing higher rates of asthma among children in her hometown neighborhood in the South Side of Chicago.

“We have a broken energy system because instead of having a core purpose of providing energy and access to all, it has as a core purpose of providing wealth and power to a small few,” Patterson said.

The panelists stressed the importance of an inclusive approach to crafting climate solutions that includes low-income, minority communities, which have historically been left out of discussions on energy.

“Climate change is an all-hands-on-deck problem. Every one of us has to be part of the solution,” said Steph Speirs, founder and CEO of Solstice, a startup that works with low-income communities to build community solar projects.

Speakers at the conference also discussed a number of policy proposals, including carbon taxes and clean energy subsidies.

In a second keynote address, former U.S. secretary of energy Ernest Moniz discussed what he sees as key energy priorities for the administration of President Joe Biden, including the increased electrification of sectors like transportation and materials production, and the decarbonization of the U.S. electricity sector by 2035.

Moniz, who is the Cecil and Ida Green Professor of Physics and Engineering Systems emeritus and special advisor to MIT President L. Rafael Reif, also cited areas like innovation and infrastructure where he sees bipartisan support for changes that could help lower greenhouse gas emissions. On the technology front, Moniz said so-called negative carbon solutions like carbon dioxide removal may be needed to help the world get to carbon neutrality in the near term. But, he added, “We’d better innovate like hell if we’re going to have something like carbon dioxide removal available in any appreciable way.”

In an interactive session, Jason Jay, a senior lecturer at MIT and the director of the MIT Sloan Sustainability Initiative, gave a demonstration of the En-ROADS Climate Solutions Simulator, a model that lets users explore the impact of different climate policies on global temperatures.

Jay entered an ambitious scenario into the simulator in which all developed countries dramatically reduce emissions beginning this year, and showed that global temperatures would still warm above 3 degrees Celsius by 2100 — a level scientists have warned would lead to catastrophic climate changes — demonstrating the importance of getting participation from China and other developing countries.

“If we want solutions to the climate crisis, they have to be global solutions,” Jay said.

A total of 15 student-led teams also pitched their startup ideas as part of the ClimateTech and Energy Prize, which concluded the conference. Finalist innovations included a biodegradable, mushroom-based packaging material, a water-treatment solution that uses no electricity or moving parts, and a company attempting to decarbonize hydrogen production.

The winning team, Osmoses, is developing membrane technologies to improve chemical separation processes. The students said their solution could dramatically reduce industrial energy consumption.

The pitch competition was a fitting end to a conference in which many speakers expressed optimism about the prospects of scaling innovations to avert the worst-case scenarios of global warming projected by experts.

Still, many speakers said, it will take a lot of work and a renewed sense of urgency from the world’s leaders.

“We can’t just wait until 2040 to meet the 2050 targets,” said Judy Chang, the Massachusetts undersecretary of energy. “Because 2050 sounds so far away, we might think can wait for the next generation, but we really only have several opportunities to take things on, and action is necessary in this decade.”

Letter from President Reif: Supporting our Asian community in a difficult time

Thu, 03/18/2021 - 10:00am

The following letter was sent to the MIT community today by President L. Rafael Reif.

To the members of the MIT community,

This message is for everyone. But let me begin with a word for the thousands of members of our MIT family – undergraduates, graduate students, postdocs, staff, faculty, alumni, parents and Corporation members – who are Asian or of Asian descent:

We would not be MIT without you. 

You are our colleagues, our students, our classmates, our lab mates, our teachers, our mentors, our leaders – and our friends. 

Across the country, a cruel signature of this pandemic year has been a terrible surge in anti-Asian violence, discrimination and public rhetoric. I know some of you have experienced such harm directly. The targets are very often women and the elderly.

These acts are especially disturbing in the context of several years of mounting hostility and suspicion in the United States focused on people of Chinese origin. The murders in Georgia Tuesday, including among the victims so many Asian women, come as one more awful shock.

I write today to express the outrage and solidarity of our community against these terrible acts, to recognize the fear, pain and sadness you may naturally be feeling – and to let you know that you are not alone.

Resources and reporting

Below my signature, you will find a listing of the many people and offices at MIT who stand ready to help. Even if you have never considered doing so before, I encourage you to reach out. Sometimes a listening ear can make an enormous difference. 

And if you have experienced harassment or discrimination at MIT, please do not hesitate to contact the Institute Discrimination and Harassment Response Office.

An upcoming community event

With leadership from Institute Community and Equity Officer (ICEO) John Dozier, his office and SPXCE, we are planning an online community event focused on our students. With help from a range of MIT cultural organizations, we are determining what kind of program would be most welcome and helpful, and what other steps we can take to further support our Asian community. We will share the details as soon as we know them.

*  *  *

Earlier this month, we lost an extraordinary citizen of MIT, ChoKyun Rha ’62, SM ’64, SM ’66, SCD ’67, a professor post-tenure of biomaterials science and engineering, at the age of 87. Raised in Seoul in a family that expected her to become a doctor, she came to MIT because she wanted to be an engineer. In 1974, she joined our faculty; in 1980, she became the first Asian female faculty member to earn tenure at MIT. Dr. Rha went on to build a remarkable career as a teacher, a mentor and a scholar.

It is difficult to imagine how alone she must have felt in her early years at MIT, when women students and Asian students numbered in just dozens. But the trail she and so many others blazed helped lead to the rich diversity of MIT we treasure today.

As we struggle against the persistence of racism and discrimination within our society, let us honor her memory by standing together and standing up for one another.

With sympathy, respect and appreciation,

L. Rafael Reif

----------------------------------------------------------------------

Community Resources

To report an incident of discrimination or harassment

Institute Discrimination and Harassment Response (idhr@mit.edu) can help anyone in the community, whether you seek support or would like to report an incident.

For support and guidance

Traveling the world for global health solutions

Thu, 03/18/2021 - 12:00am

As a kid, Andrea Orji always loved it when her grandpa would visit from Nigeria. He would share stories about his home to teach Orji, a Texas native, about her family’s heritage.

But while she and her family attended school and work, her grandpa remained at the house, frequently alone. She could tell he longed to return to the familiarity of his own country, yet he remained in order to undergo and then recover from cataract surgery. Later on, treatment for other conditions would require him to travel back and forth for months at a time. Despite the inconvenience, the quality of care in Texas was better than what was available to him in Nigeria.

Orji noticed visits by many of her other Nigerian relatives also coincided with medical procedures. Why was it better for her family members to fly halfway around the world for a necessary surgery? The question weighed heavily on Orji’s mind.

As she began applying to colleges, Orji decided that she wanted to study biomedical engineering in order to create more affordable, globally available medical devices and procedures. Unlike her three older siblings, who chose to stay in Texas, Orji hoped to attend college out of state. She also knew she wanted to travel internationally and eventually live and work in Nigeria. “It was important for me to get out of my comfort zone and think about how I would deal with settling somewhere completely new,” she says.

The search ended when Orji found MIT. Its international education program, the MIT International Science and Technology Initiatives (MISTI), provided plenty of opportunities for her to explore her interest in working overseas. While there were no programs available in Nigeria, Orji says she was amazed at the variety of destinations where she could study and explore future careers.

Orji is now a senior studying chemical engineering with a focus in biomedical applications and interests in global health. She has studied and worked abroad in Brazil, South Africa, and India, and credits these global experiences for giving her new perspectives on her Nigerian roots, while also teaching her new solutions to tackle ever-pressing global health challenges.

During her third year, Orji worked through MISTI Global Teaching Lab to introduce biology and chemistry labs to an all-girls summer program in Brazil. While the trip was a far distance from Nigeria, Orji found herself discovering aspects of West African history. “At the time, I didn’t know that Brazil has such a large Afro-Brazilian population. Many of Brazil’s traditions, such as Carnival, are actually influenced by Afro-Brazilian music and costumes,” she says. “It got me thinking more about Black populations around the world and the different ways I can serve them.”

Later that same year, Orji traveled through MISTI to Hyderabad, India, and conducted public health research at a local hospital, LV Prasad Eye Institute. She witnessed firsthand how health disparities differ between regions in a country. While Orji explored India with fresh eyes, Nigeria was still on her mind. “I kept thinking about the influence of colonialism on both countries and how they have similar decentralized health care systems,” she says. “It led me to wonder if the methods used by LVPEI’s hospitals to improve accessibility could also be applied in Nigeria.”

Her idea to implement health solutions between countries was reaffirmed throughout her internship. “The physician I shadowed would collaborate with other doctors to ensure interactions with patients were respectful of the patients’ culture, language, and religion,” she explains. “This is something we still struggle with in America. But at LVPEI, accommodating for patient differences is seamlessly engrained in hospital practice. I think these teachings could be applied everywhere.”

The trip had a lasting impact on Orji; she switched gears and became certain she also wanted to be a doctor. “At the end of a full day of seeing patients, sometimes I’d tear up. The way the hospital prioritized care for everyone, regardless of income or background, was mind-blowing to me. They managed to combine all the things I had been thinking about. I knew that this was what I wanted to do.”

While the pandemic has paused Orji’s international travels, she has continued to study health disparities outside of her community, through a remote internship helping to digitize contact-tracing in Navajo Nation, which has been hit with a disproportionate number of Covid-19 cases. Since last summer, Orji has been part of a team working to implement a contact-tracing app; her role includes helping to bridge the communication gap between the app development team and local health care workers.

“A lot of failings happen when you don’t adapt the technology to consider its users. For example, the app would ask the user if they had been in contact with someone at a hotel, even if there were no hotels in the area,” she says. “Any time saved on the app was critical for contact tracers, who often had many other responsibilities. We had to really understand the local population so the app could be efficient for both users and researchers.”

Orji also credits her favorite class, 10.495 (Molecular Design and Bioprocess Development of Immunotherapies), for teaching her about how to adapt medical innovations to local communities. “We studied the complications that come from translating technologies created in higher-income countries to lower-income countries,” she says. “I loved how it taught process design while also considering political challenges that I had struggled to incorporate from my minor classes, such as Africa and the Politics of Knowledge. I think that understanding the disparities in a system can help physicians advocate for their patients better.”

Orji also loves to explore the world through dance. Since arriving to MIT, she has been a dancer and choreographer for Sakata Afrique, an Afro-Caribbean dance group. Dancing has not only introduced Orji to other students from Africa and its diasporas but also expanded her knowledge of other African cultures. “Each region has its own unique moves, so I love to create with other members and bring their ideas together into one dance,” she says.

With graduation quickly approaching, Orji has cemented her decision to become a doctor by applying to medical school. She believes her engineering background will be instrumental to her work as a physician. “I’m glad that I took the engineering route, because I’ve learned a lot of different ways of thinking from doing it. I can understand the technology that lies beneath the public policy.”

Orji still plans on one day living in Nigeria but chooses not to focus her future solely on one country. “My experiences abroad have taught me that there’s so much to learn from different countries that could be applied elsewhere. No matter where I end up physically living, I want to be part of a global network of doctors that believes in the power of collaboration,” she says.

“As we’ve seen with Covid-19, we live in a globalized world where disease doesn’t stop at borders. Solutions shouldn’t either.”

A remedy for the spread of false news?

Wed, 03/17/2021 - 12:00pm

Stopping the spread of political misinformation on social media may seem like an impossible task. But a new study co-authored by MIT scholars finds that most people who share false news stories online do so unintentionally, and that their sharing habits can be modified through reminders about accuracy.

When such reminders are displayed, it can increase the gap between the percentage of true news stories and false news stories that people share online, as shown in online experiments that the researchers developed.

“Getting people to think about accuracy makes them more discerning in their sharing, regardless of ideology,” says MIT Professor David Rand, co-author of a newly published paper detailing the results. “And it translates into a scalable and easily implementable intervention for social media platforms.”

The study also indicates why people share false information online. Among people who shared a set of false news stories used in the study, around 50 percent did so because of inattention, related to the hasty way people use social media; another 33 percent were mistaken about the accuracy of the news they saw and shared it because they (incorrectly) thought it was true; and about 16 percent knowingly shared false news headlines.

“Our results suggest that the large majority of people across the ideological spectrum want to share only accurate content,” says Rand, the Erwin H. Schell Professor at the MIT Sloan School of Management and director of MIT Sloan’s Human Cooperation Laboratory and Applied Cooperation Team. “It’s not like most people are just saying, ‘I know this is false and I don’t care.’”

The paper, “Shifting attention to accuracy can reduce misinformation online,” is being published today in Nature. In addition to Rand, the co-authors are Gordon Pennycook, an assistant professor at the University of Regina; Ziv Epstein, a PhD candidate at the MIT Media Lab; Mohsen Mosleh, a lecturer at the University of Exeter Business School and a research affiliate at MIT Sloan; Antonio Arechar, a research associate at MIT Sloan; and Dean Eckles, the Mitsubishi Career Development Professor and an associate professor of marketing at MIT Sloan.

Inattention, confusion, or political motivation?

Observers have offered different ideas to explain why people spread false news content online. One interpretation is that people share false material for partisan gain, or to gain attention; another view is that people accidentally share inaccurate stories because they are confused. The authors advance a third possibility: inattention and the simple failure to stop and think about accuracy.

The study consists of multiple experiments, using more than 5,000 survey respondents from the U.S., as well as a field experiment conducted on Twitter. The first survey experiment asked 1,015 participants to rate the accuracy of 36 news stories (based on the headline, first sentence, and an image), and to say if they would share those items on social media. Half of the news items were true and half were false; half were favorable to Democrats and half were favorable to Republicans.

Overall, respondents considered sharing news items that were false but aligned with their views 37.4 percent of the time, even though they considered such headlines to be accurate just 18.2 percent of the time. And yet, at the end or the survey, a large majority of the experiment’s participants said accuracy was very important when it comes to sharing news online.

But if people are being honest about valuing accuracy, why do they share so many false stories? The study’s balance of evidence points to inattention and a knowledge deficit, not deception.

For instance, in a second experiment with 1,507 participants, the researchers examined the effect of shifting users’ attention toward the concept of accuracy. Before deciding whether they would share political news headlines, half of the participants were asked to rate the accuracy of a random nonpolitical headline — thereby emphasizing the concept of accuracy from the outset.

Participants who did not do the initial accuracy rating task said they were likely to share about 33 percent of true stories and 28 percent of false ones. But those who were given an initial accuracy reminder said they would share 34 percent of true stories and 22 percent of the false ones. Two more experiments replicated these results using other headlines and a more representative sample of the U.S. population.

To test whether these results could be applied on social media, the researchers conducted a field experiment on Twitter. “We created a set of bot accounts and sent messages to 5,379 Twitter users who regularly shared links to misinformation sites,” explains Mosleh. “Just like in the survey experiments, the message asked whether a random nonpolitical headline was accurate, to get users thinking about the concept of accuracy.” The researchers found that after reading the message, the users shared news from higher-quality news sites, as judged by professional fact-checkers.

How can we know why people share false news?

A final follow-up experiment, with 710 respondents, shed light on the nagging question of why people share false news. Instead of just deciding whether to share news headlines or not, the participants were asked to explicitly assess the accuracy of each story first. After doing that, the percentage of false stories that participants were willing to share dropped from about 30 percent to 15 percent.

Because that figure dropped in half, the researchers could conclude that 50 percent of the previously shared false headlines had been shared because of simple inattention to accuracy. And about a third of the shared false headlines were believed to be true by participants — meaning about 33 percent of the misinformation was spread due to confusion about accuracy.

The remaining 16 percent of the false news items were shared even though the respondents recognized them as being false. This small minority of cases represents the high-profile, “post-truth” type of purposeful sharing of misinformation.

A ready remedy?

“Our results suggest that in general, people are doing the best they can to spread accurate information,” Epstein says. “But the current design of social media environments, which can prioritize engagement and user retention over accuracy, stacks the deck against them.”

Still, the scholars think, their results shows that some simple remedies are available to the social media platforms.

“A prescription is to occasionally put content into people’s feeds that primes the concept of accuracy,” Rand says.

“My hope is that this paper will help inspire the platforms to develop these kinds of interventions,” he adds. “Social media companies by design have been focusing people’s attention on engagement. But they don’t have to only pay attention to engagement — you can also do proactive things to refocus users’ attention on accuracy.” The team has been exploring potential applications of this idea in collaboration with researchers at Jigsaw, a Google unit, and hope to do the same with social media companies.

Support for the research was provided, in par,t by the Ethics and Governance of Artificial Intelligence Initiative of the Miami Foundation, the William and Flora Hewlett Foundation, the Omidyar Network, the John Templeton Foundation, the Canadian Institutes of Health Research, and the Social Sciences and Humanities Research Council of Canada.

ChoKyun Rha, professor post-tenure of biomaterials sciences and engineering, dies at 87

Wed, 03/17/2021 - 12:00am

ChoKyun Rha ’62, SM ’64, SM ’66, SCD ’67, an MIT professor post-tenure and a groundbreaker in biomaterials science and engineering, died March 2 in Boston. She was 87.

The first woman of Asian descent to receive tenure at MIT, Rha held four degrees from the Institute and taught at MIT for more than four decades. Her husband, MIT professor of microbiology Anthony Sinskey ScD ’67, also attended MIT, as did their two sons — Tong-ik Lee Sinskey ’79, SM ’80 and Taeminn Song MBA ’95, who is the director of strategy and strategic initiatives for MIT Information Systems and Technology (IS&T) — and two granddaughters.

“MIT is my home,” Rha told MIT Technology Review in 2006. “I absolutely love the Institute and feel obliged to do whatever I can for it, not only because it’s done so much for me, but also because I feel I am part of this great institution.”

Rha was born and raised in Seoul, Korea. According to family members, her father was a prominent medical doctor who was a pioneer in anatomy, and she developed an interest early in chemical engineering, food science, and food technologies for the development of new foods, medicines, and chemicals. Rha came to the United States in 1956 with the intention of attending MIT and the idea of learning how to design and produce high-quality baby food for families in South Korea.

Rha went on to explore the science of biomaterials and their translation toward clinical use. She leveraged frontier tools of chemistry and biotechnology for the discovery of novel biomolecules and high-resolution molecular structure, function, and bioactivity determination. Her creative passion and perseverance led to the creation of several biotech companies in the health and wellness platforms. After helping to start the biopolymer program at biotechnology firm Genzyme, she traveled to Malaysia, Thailand, the Philippines, and Australia, deciding to work on biotechnology projects with Malaysia because of its biodiversity, expertise in plantation sciences, and its educational system. Rha formed and was the principal investigator for the Malaysia-MIT Biotechnology Partnership Program, which involved several Malaysian research institutions and MIT.

Her research with undergraduate students, graduate students, and postdocs led to technologies that were foundational to the development of several biotechnology and food science organizations and to her publishing more than 200 papers. Rha held more than 20 patents. She was also a founding member of Women’s World Banking, which provides support to microfinance institutions that offer credit to low-income entrepreneurs in the developing world, especially women.

Throughout her career, Rha was known as a compelling colleague and educator and a generous mentor. Many condolence notes sent to her husband and family from all over the world included acknowledgements of her intellectual influence, as well as fond remembrances of the many parties, dinners, and culinary adventures she hosted or organized — often to celebrate the accomplishments of her students, colleagues, and friends.

“Professor Rha was an amazing mentor,” says Anushree Subramaniam ’10, a former MIT student who worked in Rha’s Biomaterials Science and Engineering Lab. “She was an ‘ideas person’ and would encourage me to dream big and to strive to do work that would change the world. I never had an interaction with Professor Rha where I did not come away enriched and having learned something. Once you met her, you were immediately engulfed by the warmth of her personality, her unparalleled intellectual prowess, and her iconic style.”

Many photos posted online as a memorial showed Rha with students, colleagues, her family, and her husband, who was “her confidant, colleague, supporter, and lifelong partner,” according to Rha’s granddaughter, Deborah Jiehyun Song.

Rha established a gift annuity in 2006 whose ultimate purpose was updated in 2019 to provide financial support for graduate students in the Department of Biology, with preference for students interested in microbiology.

As Song wrote in a tribute to her grandmother, “she will be forever missed and remembered as a bright soul that strove to change the world for the better with her steadfastness, style, spirit, and smarts.”

In addition to her husband and two sons, Rha is survived by her daughter-in-law, Hyunmee Elaine Song, and five grandchildren, and she was a sister to WanKyun Kim, ChungKyun Kim, HwaKyun Cha, SooKyun Rha, the late SungKyun Rha, TaeKyun Rha, and YoungKyun Rha. Rha’s family will host a memorial in October. Gifts in Rha’s memory can be made to the ChoKyun Rha (1962) and Anthony J Sinskey (1967) Fund.

The physicist and the hospital

Wed, 03/17/2021 - 12:00am

It’s hard to say that Thomas Heldt has had just one career. He’s assisted with open heart surgery. He’s studied the physiology of human space travel. Most recently, he’s designed medical devices to help patients with brain injury. “It’s been a serendipitous path,” says Heldt, a recently tenured faculty member in MIT’s Department of Electrical Engineering and Computer Science (EECS).

But there is a through line: Heldt operates at the intersection of physics and medicine, where fundamental physical principles intersect with human health. And through his varied career, Heldt has been grateful for the mentorship he’s received from scientists and doctors alike.

Heldt’s love of physics came first. He grew up in Neuwied, Germany, not too far from the French border. By middle school, Heldt says “it was clear to me that my career preference would be in math and physics.” For that he credits his teachers, who piqued his curiosity through hands-on tabletop experiments in the classroom. He followed that curiosity to college at Johannes Gutenberg University in Mainz, Germany. Selecting his major was a no-brainer. “Physics was it,” says Heldt. “There was no doubt in my mind.”

But once at university, Heldt had trouble specializing. He was equally enthralled by elementary particle physics and by astrophysics: “The two extremes,” he says, “the very small scale and the very large scale.” Ultimately, Heldt found inspiration in a completely different field: medicine. After sitting in on some cardiology lectures and taking an anatomy class, “I was really fascinated by how the heart forms,” he says. “During embryogenesis it starts as a long tube, then it differentially folds on top of itself, and then certain walls disappear while other walls appear, and” — voila!  — “you have the four chambers of the heart. That was really cool.” Heldt added medicine as a second major.

While still an undergraduate, Heldt landed an internship observing pediatric heart surgery. He would stand on a pedestal, peering right over the surgeon’s shoulder. “These were some very intense procedures — six-hour procedures. One condition for being allowed into the operating room was that I’d come prepared.” Heldt would read up on the cases beforehand, and the surgeon would occasionally quiz Heldt as he worked. Heldt also took note of the rest of the operating room. “You have all this technology around,” he says, “such as bedside monitors, so you talk about pressure and flows and the electrical activity of the heart. It was fantastic.”

One day Heldt arrived for an observation. The surgeon didn’t notice him at first, but soon turned around and said, “Oh, I didn’t know you were here. We’re one [assistant] short. You have to come to the operating table.” Suddenly, Heldt found himself holding the incision open with retractors and suctioning blood away from the operation site. Though the experience didn’t make Heldt want to become a surgeon, being in the operating room — surrounded by monitors and other machinery — was an inspiration. “That hooked me on the intersection of physics and medicine,” he says. “I knew that’s where I wanted to go.”

After earning master’s degrees in physics from Yale University, Heldt arrived at MIT to pursue a PhD in medical physics through the Harvard-MIT Program in Health Sciences and Technology. He researched the cardiovascular response to microgravity, aiming to pinpoint why astronauts tended to faint upon returning from space. He developed a mathematical model of the cardiovascular system and compared it to data collected from actual astronauts. Heldt enjoyed working with a team that included both doctors and scientists interested in basic research. “It was really intellectually stimulating,” he says.

After finishing his PhD, he was looking for another opportunity to use data and computers to improve health outcomes. “So, I asked, ‘Where do you have a lot of data streams from patients’ physiology?’ And that’s in intensive care,” he says.

Heldt stayed at MIT, first as a postdoc, next as a research scientist at the Research Laboratory of Electronics. In 2013, he became a faculty member in EECS and the newly formed Institute for Medical Engineering and Science. His research focus has shifted from the heart to the brain.

“We’re trying to understand the physiology of the injured brain,” says Heldt. “The core mission of the lab is to work with anesthesiologists, neurologists, neurosurgeons, and neurointensivists, our collaborators, to help measure the health of the brain and help clinicians take better care of patients who have neurological conditions.”

At first, Heldt’s neurological research aimed at better understanding brain development in premature infants, who have a higher likelihood of brain injury than full-term infants. He collected and analyzed data to find out why premature infants suffered this risk, and how to reduce it. “If you can figure out some of these mechanisms, could you prevent some of this brain injury?” he muses.

Heldt’s group also uses neurological data from older patients to work on the longstanding challenge of measuring intracranial pressure noninvasively. Brain injuries and certain illnesses can cause swelling in the brain, a dangerous situation that can lead to long-term damage or even death. But current techniques for monitoring brain swelling are themselves invasive and risky, requiring a hole drilled into the skull for catheter insertion. So, the procedure is generally reserved for the highest-risk patients.

Heldt is developing a model-based approach to monitoring intracranial pressure (ICP) that could allow ICP to be estimated more safely. With collaborators at Harvard, Boston Children’s Hospital, Boston Medical Center, and Beth-Israel Deaconess Medical Center, he is working on a model of ICP that relies on two data streams: ultrasound measurements of cerebral blood flow and continuous measurements of blood pressure.

One day, noninvasive ICP monitoring could be used on a wider variety of patients, not just those at the highest risk. For example, it could help doctors determine whether a patient who arrives to the ER unresponsive has had a traumatic brain injury or is inebriated — two possibilities that would warrant different treatment courses. While the technology is still emerging, “the results so far are very promising,” says Heldt, who has related projects focusing on cerebral perfusion and embolic load monitoring. “We’re at the cusp of developing a suite of algorithms and technologies that will allow us to monitor the brain much better.”

It's been a winding career path for Heldt. But it’s worked out, largely thanks to fantastic mentors along the way, he says. “I’m very thankful that when these bifurcations and decision points were made, there was always been someone who nudged me in one direction with a remarkable lack of self-interest,” he says.

Now it’s Heldt’s turn to play the mentor. “I think my proudest achievement is the students I work with,” he says. “Seeing them succeed and find their own niche — to the extent that I may have played a small part in that is a very satisfying feeling.”

Scene at MIT: Ruth Anderson, pioneer of mathematics and computing

Tue, 03/16/2021 - 4:20pm

Ruth Krock Anderson is a mathematician and computing pioneer who has seen a lot in her 102 years. Born in Boston in 1918, she was interested in math from an early age and earned a mathematics degree at Boston Teachers College, now part of the University of Massachusetts. Soon thereafter, Anderson was asked to join the MIT Radiation Laboratory, which made key contributions to the development of microwave radar technology during the second world war. “There are quite a few books written about women programmers in World War II to help in the war, and I was one of them,” Anderson stated in a 2019 interview.

At MIT, Anderson worked on computer programs that assisted scientists and engineers working on new radar technology. Her colleagues at the Rad Lab included Betty Campbell and Barbara Levine, both of whom would continue on in computer science after the war, as well as Harold Levine, who became a math professor at Stanford University. This photo of Anderson shows her in front of Building 10 on V-J Day in 1945.

Anderson eventually moved to California to work for the U.S. Navy on drone-tracking technology. But she would spend most of her career at the National Bureau of Standards in Washington. There, she worked for Ethel Marden, a computing pioneer who also, according to Anderson’s daughter Karen, was “remembered for lobbying for family-friendly work schedules for employees — specifically, my mom, who job-shared after I was born.”

Today, Anderson lives in a retirement community in Naples, Florida. She is one of very few people who’ve lived through both the 1918 influenza pandemic and our current pandemic; on Jan. 19, at age 102, she received her second dose of the Pfizer Covid-19 vaccine.

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How to prevent short-circuiting in next-gen lithium batteries

Tue, 03/16/2021 - 12:00pm

As researchers push the boundaries of battery design, seeking to pack ever greater amounts of power and energy into a given amount of space or weight, one of the more promising technologies being studied is lithium-ion batteries that use a solid electrolyte material between the two electrodes, rather than the typical liquid.

But such batteries have been plagued by a tendency for branch-like projections of metal called dendrites to form on one of the electrodes, eventually bridging the electrolyte and shorting out the battery cell. Now, researchers at MIT and elsewhere have found a way to prevent such dendrite formation, potentially unleashing the potential of this new type of high-powered battery.

The findings are described in the journal Nature Energy, in a paper by MIT graduate student Richard Park, professors Yet-Ming Chiang and Craig Carter, and seven others at MIT, Texas A&M University, Brown University, and Carnegie Mellon University.

Solid-state batteries, Chiang explains, have been a long-sought technology for two reasons: safety and energy density. But, he says, “the only way you can reach the energy densities that are interesting is if you use a metal electrode.” And while it’s possible to couple that metal electrode with a liquid electrolyte and still get good energy density, that does not provide the same safety advantage as a solid electrolyte does, he says.

Solid state batteries only make sense with metal electrodes, he says, but attempts to develop such batteries have been hampered by the growth of dendrites, which eventually bridge the gap between the two electrode plates and short out the circuit, weakening or inactivating that cell in a battery.

It’s been known that dendrites form more rapidly when the current flow is higher — which is generally desirable in order to allow rapid charging. So far, the current densities that have been achieved in experimental solid-state batteries have been far short of what would be needed for a practical commercial rechargeable battery. But the promise is worth pursuing, Chiang says, because the amount of energy that can be stored in experimental versions of such cells, is already nearly double that of conventional lithium-ion batteries.

The team solved the dendrite problem by adopting a compromise between solid and liquid states. They made a semisolid electrode, in contact with a solid electrolyte material. The semisolid electrode provided a kind of self-healing surface at the interface, rather than the brittle surface of a solid that could lead to tiny cracks that provide the initial seeds for dendrite formation.

The idea was inspired by experimental high-temperature batteries, in which one or both electrodes consist of molten metal. According to Park, the first author of the paper, the hundreds-of-degrees temperatures of molten-metal batteries would never be practical for a portable device, but the work did demonstrate that a liquid interface can enable high current densities with no dendrite formation. “The motivation here was to develop electrodes that are based on carefully selected alloys in order to introduce a liquid phase that can serve as a self-healing component of the metal electrode,” Park says.

The material is more solid than liquid, he explains, but resembles the amalgam dentists use to fill a cavity — solid metal, but still able to flow and be shaped. At the ordinary temperatures that the battery operates in, “it stays in a regime where you have both a solid phase and a liquid phase,” in this case made of a mixture of sodium and potassium. The team demonstrated that it was possible to run the system at 20 times greater current than using solid lithium, without forming any dendrites, Chiang says. The next step was to replicate that performance with an actual lithium-containing electrode.

In a second version of their solid battery, the team introduced a very thin layer of liquid sodium potassium alloy in between a solid lithium electrode and a solid electrolyte. They showed that this approach could also overcome the dendrite problem, providing an alternative approach for further research.

The new approaches, Chiang says, could easily be adapted to many different versions of solid-state lithium batteries that are being investigated by researchers around the world. He says the team’s next step will be to demonstrate this system’s applicability to a variety of battery architectures. Co-author Viswanathan, professor of mechanical engineering at Carnegie Mellon University, says, “We think we can translate this approach to really any solid-state lithium-ion battery. We think it could be used immediately in cell development for a wide range of applications, from handheld devices to electric vehicles to electric aviation.”

“Metal penetration through solid electrolyte separators is a key challenge facing high energy-density batteries, and to date much attention has been directed toward the properties of the separator material through which the metal penetrates,” says Paul Albertus, an associate professor of chemical and biomolecular engineering at the University of Maryland, who was not associated with this research. Noting that the new work focuses instead on the properties of the metal electrode itself, he says the research “is important for both setting scientific priorities for understanding metal penetration, as well as developing innovations to help mitigate this important failure mode.”

The team also included Christopher Eschler, Cole Fincher, and Andres Badel at MIT; Pinwen Guan at Carnegie Mellon University; and Brian Sheldon at Brown University. The work was supported by the U.S. Department of Energy, the National Science Foundation, and the MIT-Skoltech Next Generation Program.

Study: One enzyme dictates cells’ response to a probable carcinogen

Tue, 03/16/2021 - 11:00am

In the past few years, several medications have been found to be contaminated with NDMA, a probable carcinogen. This chemical, which has also been found at Superfund sites and in some cases has spread to drinking water supplies, causes DNA damage that can lead to cancer.

MIT researchers have now discovered a mechanism that helps explain whether this damage will lead to cancer in mice: The key is the way cellular DNA repair systems respond. The team found that too little activity of one enzyme necessary for DNA repair leads to much higher cancer rates, while too much activity can produce tissue damage, especially in the liver, which can be fatal.

Activity levels of this enzyme, called AAG, can vary greatly among different people, and measuring those levels could allow doctors to predict how people might respond to NDMA exposure, says Bevin Engelward, a professor of biological engineering at MIT and the senior author of the study. “It may be that people who are low in this enzyme are more prone to cancer from environmental exposures,” she says.

MIT postdoc Jennifer Kay is the lead author of the new study, which appears today in Cell Reports.

Potential hazards

For several years, Engelward’s lab, in collaboration with the lab of MIT Professor Leona Samson, has been working on a research project, funded by the National Institute of Environmental Health Sciences, to study the effects of exposure to NDMA. This chemical is found in Superfund sites including the contaminated Olin Chemical site in Wilmington, Massachusetts. In the early 2000s, municipal water wells near the site had to be shut down because the groundwater was contaminated with NDMA and other hazardous chemicals.

More recently, it was discovered that several types of medicine, including Zantac and drugs used to treat type 2 diabetes and high blood pressure, had been contaminated with NDMA. This chemical causes specific types of DNA damage, one of which is a lesion of adenine, one of the bases found in DNA. These lesions are repaired by AAG, which snips out the damaged bases so that other enzymes can cleave the DNA backbone, enabling DNA polymerases to replace them with new ones.

If AAG activity is very high and the polymerases (or other downstream enzymes) can’t keep up with the repair, then the DNA may end up with too many unrepaired strand breaks, which can be fatal to the cell. However, if AAG activity is too low, damaged adenines persist and can be read incorrectly by the polymerase, causing the wrong base to be paired with it. Incorrect insertion of a new base produces a mutation, and accumulated mutations are known to cause cancer.

In the new study, the MIT team studied mice with high levels of AAG — six times the normal amount — and mice with AAG knocked out. After exposure to NDMA, the mice with no AAG had many more mutations and higher rates of cancer in the liver, where NDMA has its greatest effect. Mice with sixfold levels of AAG had fewer mutations and lower cancer rates, at first glance appearing to be beneficial. However, in those mice, the researchers found a great deal of tissue damage and cell death in the liver.

Mice with normal amounts of AAG (“wild-type” mice) showed some mutations after NDMA exposure but overall were much better protected against both cancer and liver damage.

“Nature did a really good job establishing the optimal levels of AAG, at least for our animal model,” Engelward says. “What is striking is that the levels of one gene out of 23,000 dictates disease outcome, yielding opposite effects depending on low or high expression.” If too low, there are too many mutations; if too high, there is too much cell death.

Varying responses

In humans, there is a great deal of variation in AAG levels between different people: Studies have found that some people can have up to 20 times more AAG activity than others. This suggests that people may respond very differently to damage caused by NDMA, Kay says. Measuring those levels could potentially allow doctors to predict how people may respond to NDMA exposure in the environment or in contaminated medicines, she says.

The researchers next plan to study the effects of chronic, low-level exposure to NDMA in mice, which they hope will shed light on how such exposures might affect humans. “That’s one of the top priorities for us, to figure out what happens in a real world, everyday exposure scenario,” Kay says.

Another population for which measuring AAG levels could be useful is cancer patients who take temozolomide, a chemotherapy drug that causes the same kind of DNA damage as NDMA. It’s possible that people with high levels of AAG could experience more severe toxic side effects from taking the drug, while people with lower levels of AAG could be susceptible to mutations that might lead to a recurrence of cancer later in life, Kay says, adding that more studies are needed to investigate these potential outcomes.

The research was funded primarily by the National Institute of Environmental Health Sciences Superfund Basic Research Program, with additional support from the National Cancer Institute and the MIT Center for Environmental Health Sciences.

Other authors of the paper include Joshua Corrigan, an MIT technical associate, who is second author; Amanda Armijo, an MIT postdoc; Ilana Nazari, an MIT undergraduate; Ishwar Kohale, an MIT graduate student; Robert Croy, an MIT research scientist; Sebastian Carrasco, an MIT comparative pathologist; Dushan Wadduwage, a fellow at the Center for Advanced Imaging at Harvard University; Dorothea Torous, Svetlana Avlasevich, and Stephen Dertinger of Litron Laboratories; Forest White, an MIT professor of biological engineering; John Essigmann, a professor of chemistry and biological engineering at MIT; and Samson, a professor emerita of biology and biological engineering at MIT.

3 Questions: Task Force 2021 and the future of working at MIT

Tue, 03/16/2021 - 10:00am

This is part three in a series of interviews with co-chairs of Task Force 2021 and Beyond workstreams. Parts one and two were published in recent weeks.

MIT’s Task Force 2021 and Beyond has been at work for nine months, charged by President Rafael Reif with exploring “how MIT might invent a thriving new future” in a post-Covid world. The effort’s Administrative Workstream, whose charge included looking at the future of working at MIT, was co-chaired by Joe Higgins, vice president for campus services and stewardship, and Krystyn Van Vliet, associate provost and Michael and Sonja Koerner Professor of Materials Science and Engineering.

Higgins and Van Vliet spoke with MIT News about the recent societal changes that are likeliest to impact how employees work at MIT, the themes that arose in their group’s conversations, and the changes that might arise if some of the working group’s proposals are adopted.

Q: What changes — due to the events of this past year — do you think will have the most significant impact on working at MIT?

Van Vliet: We’ve learned so much from our unanticipated pilot with remote working — which was, of course, imposed upon us last spring by the arrival of Covid-19.

We learned that many members of the MIT community can be just as productive, if not more so, while working from home or other locations. Of course, we also learned that thousands of us — including Joe and me — cannot carry out our MIT roles without accessing campus regularly, even if not daily. And we learned new things about ourselves and our MIT teams when we had no choice but to adapt where and how we did our work, both alone and together.

As our remote work has stretched on over many months, we’ve all come to understand what we now miss dearly about our in-person campus community. But we’ve also found ourselves grateful to have a respite from less pleasant aspects of our working lives, such as challenging Boston-area commutes.

Higgins: Along the same lines, the pandemic created a forced experiment in MIT’s operations. We learned what our current technology systems and policies can flexibly support, and where improvements could be rapidly applied to support our academic, research, and administrative functions. A rapid evolution in our building access protocols (including the creation of Covid Pass) and digital workflow management for design and construction projects are some areas that come to mind.

Q: What were themes that emerged in your group’s discussions, and in the ideas that your group put forward?

Higgins: It’s clear that the pandemic has caused our working group to think deeply about where and how we perform our work: Which activities are best performed on campus? Which can be done as well, or possibly even better or more sustainably, remotely? The group considered these questions as we look ahead to the time when more of us will be able to return to campus. As we consider the Institute’s post-pandemic stance, there is a keen desire to balance the flexibility and sustainability afforded by a range of hybrid work models — allowing us to work where we are most productive, and also maintain our sense of community that’s best created and fostered through in-person interactions.

To enable more flexible work on a sustained basis, we’ll need to continue to evolve our policies, practices, systems, platforms, and tools to support our research, education, and administrative enterprises.

Van Vliet: Consistent with a more flexible work environment, we’ll need to consider how changing work practices and technologies will change demand for the myriad types of spaces we have on campus: classrooms, research spaces (including both labs and offices), community spaces, dining spaces, outdoor spaces, residential facilities, and flexible work spaces for students, staff, and faculty.

As we think of how MIT can become a stronger Institute and support all the individuals who are part of carrying out MIT’s leading-edge research, teaching, and learning, we will also need to discuss and plan together how to use these campus spaces collaboratively.

On any urban campus, including MIT’s, space is both a real constraint and an exciting opportunity to renew and reinvent. And as the Task Force working groups emphasized to us, now is the time to think about how we better use this campus resource to align with MIT’s values, commitments to our community and the world, and central mission of impactful research and education.

Another theme woven throughout our group’s conversations was the need to enhance employee development. That includes fostering skills development and offering commensurate training, mentoring, and support to help our valued employees map out their career pathways at MIT.

A final theme that emerged in our team’s discussions — prompted by the sudden and sometimes jarring shifts that we have all experienced over the past year — is the need for agile, cross-functional teams that can help us in the accelerated development of systems and tools to support all of our work at the Institute. The teams enabling MIT’s adapted operations during the height of the pandemic were unstintingly dedicated to the rapid solutions needed. We can learn from that, of course, but aspire to a more sustainable approach to continued innovation of our work practices.

Q: If some of your group’s key ideas are implemented, how would MIT be different for its employees in the years to come?

Higgins: It seems likely that both working and learning at MIT will remain more diffuse even once physical distancing is no longer absolutely necessary.

There will always be an important on-campus element: Certain tasks and activities require in-person collaboration. At the same time, a more flexible work environment will help us create a campus environment where our precious space is focused on our highest-value activities.

This may mean that in the coming years we will see more shared and flexible spaces on campus, and possibly the emergence of MIT community worksites outside of the immediate Cambridge campus. 

Van Vliet: Looking forward, our group also feels that MIT will need to develop a more robust onboarding program for new employees. All staff must have the tools, systems, and resources to ensure their personal and professional development, creating new support for their growth and helping them build career ladders. All faculty, who work closely with many research and administrative staffers, can also benefit from improved onboarding, tools to manage our broad responsibilities, and greater awareness of and appreciation for staff roles and career trajectories. This is all part of being “One MIT,” which our working groups identified as important to building diverse, talented, and dedicated teams — no matter where we do our daily work.

We have also recommended a new agile project management team to support the implementation of MIT priority projects for administrative workflows. Ultimately, this work will help foster a more modern, data-driven infrastructure for MIT’s work on and off campus.

Ultrasound has potential to damage coronaviruses, study finds

Tue, 03/16/2021 - 12:00am

The coronavirus’ structure is an all-too-familiar image, with its densely packed surface receptors resembling a thorny crown. These spike-like proteins latch onto healthy cells and trigger the invasion of viral RNA. While the virus’ geometry and infection strategy is generally understood, little is known about its physical integrity.

A new study by researchers in MIT’s Department of Mechanical Engineering suggests that coronaviruses may be vulnerable to ultrasound vibrations, within the frequencies used in medical diagnostic imaging.

Through computer simulations, the team has modeled the virus’ mechanical response to vibrations across a range of ultrasound frequencies. They found that vibrations between 25 and 100 megahertz triggered the virus’ shell and spikes to collapse and start to rupture within a fraction of a millisecond. This effect was seen in simulations of the virus in air and in water.

The results are preliminary, and based on limited data regarding the virus’ physical properties. Nevertheless, the researchers say their findings are a first hint at a possible ultrasound-based treatment for coronaviruses, including the novel SARS-CoV-2 virus. How exactly ultrasound could be administered, and how effective it would be in damaging the virus within the complexity of the human body, are among the major questions scientists will have to tackle going forward.

“We’ve proven that under ultrasound excitation the coronavirus shell and spikes will vibrate, and the amplitude of that vibration will be very large, producing strains that could break certain parts of the virus, doing visible damage to the outer shell and possibly invisible damage to the RNA inside,” says Tomasz Wierzbicki, professor of applied mechanics at MIT. “The hope is that our paper will initiate a discussion across various disciplines.”

The team’s results appear online in the Journal of the Mechanics and Physics of Solids. Wierzbicki’s co-authors are Wei Li, Yuming Liu, and Juner Zhu at MIT.

A spiky shell

As the Covid-19 pandemic took hold around the world, Wierzbicki looked to contribute to the scientific understanding of the virus. His group’s focus is in solid and structural mechanics, and the study of how materials fracture under various stresses and strains. With this perspective, he wondered what could be learned about the virus’ fracture potential.

Wierzbicki’s team set out to simulate the novel coronavirus and its mechanical response to vibrations. They used simple concepts of the mechanics and physics of solids to construct a geometrical and computational model of the virus’ structure, which they based on limited information in the scientific literature, such as microscopic images of the virus’ shell and spikes.

From previous studies, scientists have mapped out the general structure of the coronavirus — a family of viruses that s HIV, influenza, and the novel SARS-CoV-2 strain. This structure consists of a smooth shell of lipid proteins, and densely packed, spike-like receptors protruding from the shell.

With this geometry in mind, the  team modeled the virus as a thin elastic shell covered in about 100 elastic spikes. As the virus’ exact physical properties are uncertain, the researchers simulated the behavior of this simple structure across a range of  elasticities for both the shell and the spikes.

“We don’t know the material properties of the spikes because they are so tiny — about 10 nanometers high,” Wierzbicki says. “Even more unknown is what’s inside the virus, which is not empty but filled with RNA, which itself is surrounded by a protein capsid shell. So this modeling requires a lot of assumptions.”

“We feel confident that this elastic model is a good starting point,” Wierzbicki says. “The question is, what are the stresses and strains that will cause the virus to rupture?”

A corona’s collapse

To answer that question, the researchers introduced acoustic vibrations into the simulations and observed how the vibrations rippled through the virus’ structure across a range of ultrasound frequencies.

The team started with vibrations of 100 megahertz, or 100 million cycles per second, which they estimated would be the shell’s natural vibrating frequency, based on what’s known of the virus’ physical properties.

When they exposed the virus to 100 MHz ultrasound excitations, the virus’ natural vibrations were initially undetectable. But within a fraction of a millisecond the external vibrations, resonating with the frequency of the virus’ natural oscillations, caused the shell and spikes to buckle inward, similar to a ball that dimples as it bounces off the ground.

As the researchers increased the amplitude, or intensity, of the vibrations, the shell could fracture — an acoustic phenomenon known as resonance that also explains how opera singers can crack a wineglass if they sing at just the right pitch and volume. At lower frequencies of 25 MHz and 50 MHz, the virus buckled and fractured even faster, both in simulated environments of air, and of water that is similar in density to fluids in the body.

“These frequencies and intensities are within the range that is safely used for medical imaging,” says Wierzbicki.

To refine and validate their simulations, the team is working with microbiologists in Spain, who are using atomic force microscopy to observe the effects of ultrasound vibrations on a type of coronavirus found exclusively in pigs. If ultrasound can be experimentally proven to damage coronaviruses, including SARS-CoV-2, and if this damage can be shown to have a therapeutic effect, the team envisions that ultrasound, which is already used to break up kidney stones and to release drugs via liposomes, might be harnessed to treat and possibly prevent coronavirus infection. The researchers also envision that miniature ultrasound transducers, fitted into phones and other portable devices, might be capable of shielding people from the virus.

Wierzbicki stresses that there is much more research to be done to confirm whether ultrasound can be an effective treatment and prevention strategy against coronaviruses. As his team works to improve the existing simulations with new experimental data, he plans to zero in on the specific mechanics of the novel, rapidly mutating SARS-CoV-2 virus.

“We looked at the general coronavirus family, and now are looking specifically at the morphology and geometry of Covid-19,” Wierzbicki says. “The potential is something that could be great in the current critical situation.”

Study predicts the oceans will start emitting ozone-depleting CFCs

Mon, 03/15/2021 - 3:00pm

The world’s oceans are a vast repository for gases including ozone-depleting chlorofluorocarbons, or CFCs. They absorb these gases from the atmosphere and draw them down to the deep, where they can remain sequestered for centuries and more.

Marine CFCs have long been used as tracers to study ocean currents, but their impact on atmospheric concentrations was assumed to be negligible. Now, MIT researchers have found the oceanic fluxes of at least one type of CFC, known as CFC-11, do in fact affect atmospheric concentrations. In a study appearing today in the Proceedings of the National Academy of Sciences, the team reports that the global ocean will reverse its longtime role as a sink for the potent ozone-depleting chemical.

The researchers project that by the year 2075, the oceans will emit more CFC-11 back into the atmosphere than they absorb, emitting detectable amounts of the chemical by 2130. Further, with increasing climate change, this shift will occur 10 years earlier. The emissions of CFC-11 from the ocean will effectively extend the chemical’s average residence time, causing it to linger five years longer in the atmosphere than it otherwise would. This may impact future estimations of CFC-11 emissions.

The new results may help scientists and policymakers better pinpoint future sources of the chemical, which is now banned worldwide under the Montreal Protocol.

“By the time you get to the first half of the 22nd century, you’ll have enough of a flux coming out of the ocean that it might look like someone is cheating on the Montreal Protocol, but instead, it could just be what’s coming out of the ocean,” says study co-author Susan Solomon, the Lee and Geraldine Martin Professor of Environmental Studies in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “It’s an interesting prediction and hopefully will help future researchers avoid getting confused about what’s going on.”

Solomon’s co-authors include lead author Peidong Wang, Jeffery Scott, John Marshall, Andrew Babbin, Megan Lickley, and Ronald Prinn from MIT; David Thompson of Colorado State University; Timothy DeVries of the University of California at Santa Barbara; and Qing Liang of the NASA Goddard Space Flight Center.

An ocean, oversaturated

CFC-11 is a chlorofluorocarbon that was commonly used to make refrigerants and insulating foams. When emitted to the atmosphere, the chemical sets off a chain reaction that ultimately destroys ozone, the atmospheric layer that protects the Earth from harmful ultraviolet radiation. Since 2010, the production and use of the chemical has been phased out worldwide under the Montreal Protocol, a global treaty that aims to restore and protect the ozone layer.

Since its phaseout, levels of CFC-11 in the atmosphere have been steadily declining, and scientists estimate that the ocean has absorbed about 5 to 10 percent of all manufactured CFC-11 emissions. As concentrations of the chemical continue to fall in the atmosphere, however, it’s predicted that CFC-11 will oversaturate in the ocean, pushing it to become a source rather than a sink.

“For some time, human emissions were so large that what was going into the ocean was considered negligible,” Solomon says. “Now, as we try to get rid of human emissions, we find we can’t completely ignore what the ocean is doing anymore.”

A weakening reservoir

In their new paper, the MIT team looked to pinpoint when the ocean would become a source of the chemical, and to what extent the ocean would contribute to CFC-11 concentrations in the atmosphere. They also sought to understand how climate change would impact the ocean’s ability to absorb the chemical in the future.

The researchers used a hierarchy of models to simulate the mixing within and between the ocean and atmosphere. They began with a simple model of the atmosphere and the upper and lower layers of the ocean, in both the northern and southern hemispheres. They added into this model anthropogenic emissions of CFC-11 that had previously been reported through the years, then ran the model forward in time, from 1930 to 2300, to observe changes in the chemical’s flux between the ocean and the atmosphere.

They then replaced the ocean layers of this simple model with the MIT general circulation model, or MITgcm, a more sophisticated representation of ocean dynamics, and ran similar simulations of CFC-11 over the same time period.

Both models produced atmospheric levels of CFC-11 through the present day that matched with recorded measurements, giving the team confidence in their approach. When they looked at the models’ future projections, they observed that the ocean began to emit more of the chemical than it absorbed, beginning around 2075. By 2145, the ocean would emit CFC-11 in amounts that would be detectable by current monitoring standards.

The ocean’s uptake in the 20th century and outgassing in the future also affects the chemical’s effective residence time in the atmosphere, decreasing it by several years during uptake and increasing it by up to 5 years by the end of 2200.

Climate change will speed up this process. The team used the models to simulate a future with global warming of about 5 degrees Celsius by the year 2100, and found that climate change will advance the ocean’s shift to a source by 10 years and produce detectable levels of CFC-11 by 2140.

“Generally, a colder ocean will absorb more CFCs,” Wang explains. “When climate change warms the ocean, it becomes a weaker reservoir and will also outgas a little faster.”

“Even if there were no climate change, as CFCs decay in the atmosphere, eventually the ocean has too much relative to the atmosphere, and it will come back out,” Solomon adds. “Climate change, we think, will make that happen even sooner. But the switch is not dependent on climate change.”

Their simulations show that the ocean’s shift will occur slightly faster in the Northern Hemisphere, where large-scale ocean circulation patterns are expected to slow down, leaving more gases in the shallow ocean to escape back to the atmosphere. However, knowing the exact drivers of the ocean’s reversal will require more detailed models, which the researchers intend to explore.

“Some of the next steps would be to do this with higher-resolution models and focus on patterns of change,” says Scott. “For now, we’ve opened up some great new questions and given an idea of what one might see.”

This research was supported, in part, by the VoLo Foundation, the Simons Foundation, and the National Science Foundation.

Could we recycle plastic bags into fabrics of the future?

Mon, 03/15/2021 - 12:00pm

In considering materials that could become the fabrics of the future, scientists have largely dismissed one widely available option: polyethylene.

The stuff of plastic wrap and grocery bags, polyethylene is thin and lightweight, and could keep you cooler than most textiles because it lets heat through rather than trapping it in. But polyethylene would also lock in water and sweat, as it’s unable to draw away and evaporate moisture. This antiwicking property has been a major deterrent to polyethylene’s adoption as a wearable textile.

Now, MIT engineers have spun polyethylene into fibers and yarns designed to wick away moisture. They wove the yarns into silky, lightweight fabrics that absorb and evaporate water more quickly than common textiles such as cotton, nylon, and polyester.

They have also calculated the ecological footprint that polyethylene would have if it were produced and used as a textile. Counter to most assumptions, they estimate that polyethylene fabrics may have a smaller environmental impact over their life cycle than cotton and nylon textiles.

The researchers hope that fabrics made from polyethylene could provide an incentive to recycle plastic bags and other polyethylene products into wearable textiles, adding to the material’s sustainability.

“Once someone throws a plastic bag in the ocean, that’s a problem. But those bags could easily be recycled, and if you can make polyethylene into a sneaker or a hoodie, it would make economic sense to pick up these bags and recycle them,” says Svetlana Boriskina, a research scientist in MIT’s Department of Mechanical Engineering.

Boriskina and her colleagues have published their findings today in Nature Sustainability.

Water wick

A molecule of polyethylene has a backbone of carbon atoms, each with a hydrogen atom attached. The simple structure, repeated many times over, forms a Teflon-like architecture that resists sticking to water and other molecules.

“Everyone we talked to said polyethylene might keep you cool, but it wouldn’t absorb water and sweat because it rejects water, and because of this, it wouldn’t work as a textile,” Boriskina says.

Nevertheless, she and her colleagues tried to make weavable fibers from polyethylene. They started with polyethylene in its raw powder form and used standard textile manufacturing equipment to melt and extrude polyethylene into thin fibers, similar to turning out strands of spaghetti. Surprisingly, they found that this extrusion process slightly oxidized the material, changing the fiber’s surface energy so that polyethylene became weakly hydrophilic, and able to attract water molecules to its surface.

The team used a second standard extruder to bunch multiple polyethylene fibers together to make a weavable yarn. They found that, within a strand of yarn, the spaces between fibers formed capillaries through which water molecules could be passively absorbed once attracted to a fiber’s surface.

To optimize this new wicking ability, the researchers modeled the properties of the fibers and found that fibers of a certain diameter, aligned in specific directions throughout yarn, improved the fibers’ wicking ability.

Based on their modeling, the researchers made polyethylene yarn with more optimized fiber arrangements and dimensions, then used an industrial loom to weave the yarn into fabrics. They then tested the wicking ability of polyethylene fabric over cotton, nylon, and polyester by dipping strips of the fabrics in water and measuring the time it took for the liquid to wick, or climb up each strip. They also placed each fabric on a scale over a single water droplet and measured its weight over time as the water was wicked through the fabric and evaporated.

In every test, polyethylene fabrics wicked away and evaporated the water faster than other common textiles. The researchers did observe that polyethylene lost some of its water-attracting ability with repeated wetting, but by simply applying some friction, or exposing it to ultraviolet light, they induced the material to become hydrophilic again.

“You can refresh the material by rubbing it against itself, and that way it maintains its wicking ability,” Boriskina says. “It can continuously and passively pump away moisture.”

Eco cycle

The team also found a way to incorporate color into the polyethylene fabrics, which has been a challenge, again due to the material’s resistance to binding with other molecules, including traditional inks and dyes. The researchers added colored particles into the powdered polyethylene before extruding the material into fiber form. In this way, particles were encapsulated within the fibers, successfully imparting color to them.

“We don’t need to go through the traditional process of dyeing textiles by dunking them in solutions of harsh chemicals,” Boriskina says. “We can color polyethylene fibers in a completely dry fashion, and at the end of their life cycle, we could melt down, centrifuge, and recover the particles to use again.”

The team’s dry-coloring process contributes to the relatively small ecological footprint that polyethylene would have if it were used to make textiles, the researchers say. The team calculated this footprint by using a life cycle assessment tool commonly used by the textile industry. Taking into account polyethylene’s physical properties and the processes required to make and color the fabrics, the researchers found it would require less energy to produce polyethylene textiles, compared to polyester and cotton.

“Polyethylene has a lower melting temperature so you don’t have to heat it up as much as other synthetic polymer materials to make yarn, for example,” Boriskina explains. “Synthesis of raw polyethylene also releases less greenhouse gas and waste heat than synthesis of more conventional textile materials such as polyester or nylon. Cotton also takes a lot of land, fertilizer, and water to grow, and is treated with harsh chemicals, which all comes with a huge ecological footprint.”

In its use phase, polyethylene fabric could also have a smaller environmental impact, she says, as it would require less energy to wash and dry the material compared with cotton and other textiles.

“It doesn’t get dirty because nothing sticks to it,” Boriskina says. “You could wash polyethyelene on the cold cycle for 10 minutes, versus washing cotton on the hot cycle for an hour.”

“Though a surprising finding, I think the design of experiments and the data are quite convincing,” says Shirley Meng, a materials scientist at the University of California at San Diego, who was not involved in the research. “Based on the data presented in the paper, the particular PE fabric reported here depicts superior properties than those of cotton. The main point is that recycled PE can be used to make textile, a product with significant value. This is the missing piece of PE recycling and circular economy.”

The team is exploring ways to incorporate polyethylene fabrics into lightweight, passively cooling athletic apparel, military attire, and even next-generation spacesuits, as polyethylene shields against the harmful X-ray radiation of space.

The international team included researchers from MIT, Polytechnic University of Turin in Italy, U.S. Army Combat Capabilities Development Command Soldier Center, Dana Farber Cancer Institute, INRIM Istituto Nazionale di Ricerca Metrologica in Italy, Defense Agency for Technology and Quality in South Korea, and Monterrey Institute of Technology and Higher Education in Mexico.

This research was supported, in part, by the U.S. Army Research Office, the

Advanced Functional Fabrics of America (AFFOA) Institute, MIT International Science and Technology Initiatives (MISTI), the MIT Deshpande Center, and the MIT-Tecnológico de Monterrey Nanotechnology Program.

Faster drug discovery through machine learning

Mon, 03/15/2021 - 12:00am

Drugs can only work if they stick to their target proteins in the body. Assessing that stickiness is a key hurdle in the drug discovery and screening process. New research combining chemistry and machine learning could lower that hurdle.

The new technique, dubbed DeepBAR, quickly calculates the binding affinities between drug candidates and their targets. The approach yields precise calculations in a fraction of the time compared to previous state-of-the-art methods. The researchers say DeepBAR could one day quicken the pace of drug discovery and protein engineering.

“Our method is orders of magnitude faster than before, meaning we can have drug discovery that is both efficient and reliable,” says Bin Zhang, the Pfizer-Laubach Career Development Professor in Chemistry at MIT, an associate member of the Broad Institute of MIT and Harvard, and a co-author of a new paper describing the technique.

The research appears today in the Journal of Physical Chemistry Letters. The study’s lead author is Xinqiang Ding, a postdoc in MIT’s Department of Chemistry.

The affinity between a drug molecule and a target protein is measured by a quantity called the binding free energy — the smaller the number, the stickier the bind. “A lower binding free energy means the drug can better compete against other molecules,” says Zhang, “meaning it can more effectively disrupt the protein’s normal function.” Calculating the binding free energy of a drug candidate provides an indicator of a drug’s potential effectiveness. But it’s a difficult quantity to nail down.

Methods for computing binding free energy fall into two broad categories, each with its own drawbacks. One category calculates the quantity exactly, eating up significant time and computer resources. The second category is less computationally expensive, but it yields only an approximation of the binding free energy. Zhang and Ding devised an approach to get the best of both worlds.

Exact and efficient

DeepBAR computes binding free energy exactly, but it requires just a fraction of the calculations demanded by previous methods. The new technique combines traditional chemistry calculations with recent advances in machine learning.

The “BAR” in DeepBAR stands for “Bennett acceptance ratio,” a decades-old algorithm used in exact calculations of binding free energy. Using the Bennet acceptance ratio typically requires a knowledge of two “endpoint” states (e.g., a drug molecule bound to a protein and a drug molecule completely dissociated from a protein), plus knowledge of many intermediate states (e.g., varying levels of partial binding), all of which bog down calculation speed.

DeepBAR slashes those in-between states by deploying the Bennett acceptance ratio in machine-learning frameworks called deep generative models. “These models create a reference state for each endpoint, the bound state and the unbound state,” says Zhang. These two reference states are similar enough that the Bennett acceptance ratio can be used directly, without all the costly intermediate steps.

In using deep generative models, the researchers were borrowing from the field of computer vision. “It’s basically the same model that people use to do computer image synthensis,” says Zhang. “We’re sort of treating each molecular structure as an image, which the model can learn. So, this project is building on the effort of the machine learning community.”

While adapting a computer vision approach to chemistry was DeepBAR’s key innovation, the crossover also raised some challenges. “These models were originally developed for 2D images,” says Ding. “But here we have proteins and molecules — it’s really a 3D structure. So, adapting those methods in our case was the biggest technical challenge we had to overcome.”

A faster future for drug screening

In tests using small protein-like molecules, DeepBAR calculated binding free energy nearly 50 times faster than previous methods. Zhang says that efficiency means “we can really start to think about using this to do drug screening, in particular in the context of Covid. DeepBAR has the exact same accuracy as the gold standard, but it’s much faster.” The researchers add that, in addition to drug screening, DeepBAR could aid protein design and engineering, since the method could be used to model interactions between multiple proteins.

DeepBAR is “a really nice computational work” with a few hurdles to clear before it can be used in real-world drug discovery, says Michael Gilson, a professor of pharmaceutical sciences at the University of California at San Diego, who was not involved in the research. He says DeepBAR would need to be validated against complex experimental data. “That will certainly pose added challenges, and it may require adding in further approximations.”

In the future, the researchers plan to improve DeepBAR’s ability to run calculations for large proteins, a task made feasible by recent advances in computer science. “This research is an example of combining traditional computational chemistry methods, developed over decades, with the latest developments in machine learning,” says Ding. “So, we achieved something that would have been impossible before now.”

This research was funded, in part, by the National Institutes of Health.

Planning for summer and fall at MIT

Fri, 03/12/2021 - 12:00pm

The following letter was sent to the MIT community today by President L. Rafael Reif.

To the members of the MIT community,

After 40 years in Massachusetts, I know the shift from winter to spring is governed by a dial, not a switch – and that dial can go backwards. Today on Killian Court, the grass is working up the courage to turn green. But we all know that it’s too early to stow our snow boots.

The shift from a long season governed by Covid to something better will feel this way too: not a switch, but a dial, and a dial that may at times go backwards. Maintaining movement in the right direction will require every one of us to sustain the care, carefulness, new routines and vigilant protocols of this past year. 

It will feel wonderful, overwhelmingly wonderful, to relax the restrictions that have constrained our lives. We are not quite ready for that yet. But we are ready to begin planning for a summer and fall that will look different.

I would like to sketch out the big picture. And then, over the next few weeks and months, you will be hearing more about specific plans and expectations.

A slow “dialing up” this summer

From the pace of vaccination to the rise of new viral variants, uncertainty still reigns. So we are looking at summer as a time for slowly “dialing up” toward fall.  For instance, we expect to run a few summer programs, but not all and not at full capacity. The idea is to test how well our systems do with a rising challenge but not to push them – or any of us – to the limit as we prepare for fuller operations in the fall and catch our collective breath. 

In that spirit, I would like to express, once again, my warmest appreciation and admiration for the exceptional efforts every one of you has made on MIT’s behalf this year. 

Planning for full operations in fall

If all goes well these next few months, our goal is to resume full academic and research activities on campus by the start of the new academic year in September. This means we will be inviting our full population of students to be in residence, as well as in classrooms and labs. For MIT faculty and to all employees, we intend to be ready to welcome you all back then, too – and some of you, especially those whose work centers on student life and learning, may need to come back sooner than that. 

We feel confident about this basic framework – while recognizing, with humility, that there is a great deal we do not and cannot know yet. But we do expect that our lives together will be different in some important ways, and we are exploring those ideas deliberately now.

Exploring better ways of working

Following up on one of the principal recommendations of Task Force 2021, we are weighing new working arrangements that emerged during this year, when so many of us worked remotely.

Led by VP for Human Resources Ramona Allen, VP for Campus Services and Stewardship Joe Higgins, and Associate Provost Krystyn Van Vliet, a cross-Institute planning team we call “Work Succeeding" is beginning to assess how various hybrid approaches to work life could play out for MIT staff. By systematically testing a variety of models, the project will produce a range of useful blueprints for how, as this pandemic era gradually recedes, we can arrive at a new normal that offers new and better ways of working, in service to our mission. As this assessment and testing get underway, we will have more to share on this subject. 

Over the next few weeks, watch for more detailed updates addressing other questions, including messages specifically for employees; for students, including those with remote international appointments; and for everyone involved in summer programs.

*   *   *

Reflecting on the past year and considering what lies ahead, I fervently hope that the coming summer – EAPS assures me it is coming – will allow time and space for each of you to rest, relax, recuperate and reconnect.

For now, let’s hope for spring! And please remember, the best vaccine is whichever one you can get the soonest!

Sincerely,

L. Rafael Reif

Work Succeeding Steering Committee

Ramona Allen, Vice President for Human Resources

Robin Elices, Executive Director
Office of the Executive Vice President and Treasurer

Amy Glasmeier, Professor
Department of Urban Studies and Planning

Joe Higgins, Vice President for Campus Services and Stewardship

Timothy Jamison, Associate Provost

Erin Kelly, Professor
Sloan School of Management

Thomas Kochan, Professor
Sloan School of Management

Christina Lo, Director of Strategic Sourcing and Contracts
Office of the Vice President for Finance

Todd Robinson, Senior Campus Planner
Office of Campus Planning

Krystyn Van Vliet, Associate Provost

Work Succeeding Working Group

Gabrielle Accardi, Human Resources Manager
Office of Strategic Alliances and Technology Transfer

Sharon Bridburg, Director of Human Resources
Office of the Vice Chancellor

Chris Caplice, Executive Director
Center for Transportation and Logistics

Peter Cummings, Executive Director for Administration
Division of Student Life

Tolga Durak, Managing Director
Environment, Health and Safety Office

Dahlia Fetouh, Counsel
Office of the General Counsel

Bill Fitzgerald, Executive Director, Finance and Operations
MIT Alumni Association

Ellen Gilmore, Executive Director of Human Resources and Strategic Talent Management
Office of the Vice President for Resource Development

Eamon Kearns, Senior Director, Emerging Solutions
Information Systems & Technology

Elizabeth Lennox, Assistant Dean for Finance and Administration
School of Engineering

Colleen Leslie, Assistant Provost for Research Administration

Jennifer Marshall, Assistant Director
Office of Campus Planning

Ann McNamara, Executive Director, Finance, Administration, and Operations
Office of the President

Lesley Millar-Nicholson, Director of Technology Licensing Office and Director, Catalysts
Office of Strategic Alliances and Technology Transfer

Eileen Ng, Assistant Dean for Administration
Schwarzman College of Computing

Greg Raposa, Space Administrator
Office of the Provost

Mary Ellen Royer, Manager, Human Resources Operations
Human Resources Department

Brian Schuetz, Executive Director
MIT Medical

Ann Warner-Harvey, Director of Administrative Services and Operations
Office of the Vice President for Finance

Heather Williams, Assistant Dean
School of Science

Carol Wood, Director, Research Administration Systems Support
Office of the Vice President for Research

Artificial intelligence that more closely mimics the mind

Fri, 03/12/2021 - 12:00am

For all the progress that’s been made in the field of artificial intelligence, the world’s most flexible, efficient information processor remains the human brain. Although we can quickly make decisions based on incomplete and changing information, many of today’s artificial intelligence systems only work after being trained on well-labeled data, and when new information is available, a complete retraining is often required to incorporate it.

Now the startup Nara Logics, co-founded by an MIT alumnus, is trying to take artificial intelligence to the next level by more closely mimicking the brain. The company’s AI engine uses recent discoveries in neuroscience to replicate brain structure and function at the circuit level.

The result is an AI platform that holds a number of advantages over traditional neural network-based systems. While other systems use meticulously tuned, fixed algorithms, users can interact with Nara Logics’ platform, changing variables and goals to further explore their data. The platform can also begin working without labeled training data, and can incorporate new datasets as they become available. Perhaps most importantly, Nara Logics’ platform can provide the reasons behind every recommendation it makes — a key driver of adoption in sectors like health care.

“A lot of our health care customers say they’ve had AI systems that give the likelihood of somebody being readmitted to the hospital, for example, but they’ve never had those ‘but why?’ reasons to be able to know what they can do about it,” says Nara Logics CEO Jana Eggers, who leads the company with CTO and founder Nathan Wilson PhD ’05.

Nara Logics’ AI is currently being used by health care organizations, consumer companies, manufacturers, and the federal government to do things like lower costs and better engage with customers.

“It’s for people whose decisions are getting complicated because there’s more factors [and data] being added, and for people that are looking at complex decisions differently because there's novel information available,” Eggers says.

The platform’s architecture is the result of Wilson’s decision to embrace the complexities of neuroscience rather than abstract away from them. He developed that approach over more than a decade working in MIT’s Department of Brain and Cognitive Sciences, which has long held the mission of reverse engineering the human mind.

“At Nara Logics, we think neuroscience is on a really good track that’s going to lead to really exciting ways to make decisions that we haven't seen before,” Wilson says.

Following a passion

Wilson attended Cornell University for his undergraduate and master’s degrees, but once he got to MIT in 2000, he stuck around. Over the course of a five-year PhD and a seven-year postdoc, he created mathematical frameworks to simulate brain function.

“The community at MIT is really focused on coming up with new models of computation that go beyond what computer science offers,” Wilson says. “The work is connected with computer science, but also considers what our brain is doing that could teach us how computers work, or how computers could work.”

On nights and weekends during the final years of his postdoc, from 2010 to 2012, Wilson was also beginning to translate his algorithms into a commercial system in work that would be the foundation of Nara Logics. In 2014, his work caught the attention of Eggers, who had led a number of successful businesses but had grown jaded about the hype around artificial intelligence.

Eggers became convinced Nara Logics’ AI engine offered a superior way to help businesses. Even back then the engine, which the company refers to as Nara Logics Synaptic Intelligence, had properties that made it unique in the field.

In the engine, objects in customers’ data, such as patients and treatments, organize into matrices based on features they share with other objects, in a structure similar to what has been observed in biological systems. Relationships between objects also form through a series of local functions the company calls synaptic learning rules, adapted from cell- and circuit-based neuroscience studies.

“What we do is catalog all the metadata and what we call our Connectomes go in and mine the database of unstructured data and build links across all of it that relate these things,” Wilson explains. “Once you have that background, you can go in and say, ‘I like this, this, and this,’ and you let the engine crunch the data and give you matches to those parameters. What you didn’t have to do is have any notion of what the right answer was for lots of similar people. You skip that whole step.”

Each object in Nara Logics’ Synaptic Intelligence stores its properties and rules locally, allowing the platform to adjust to new data by updating only a small number of associated objects. The bottom-up approach is believed to be used by the brain.

“That’s totally different than deep learning or other approaches that just say, ‘We’re going to globally optimize everything, and each cell does what the global algorithm tells it,’” Wilson explains. “Neuroscientists are telling us each cell is making decisions on its own accord to an extent.”

The design allows users to explore relationships in data by “activating” certain objects or features and seeing what else gets activated or suppressed.

To give an answer, Nara Logics’ engine only activates a small number of objects in its dataset. The company says this is similar to the “sparse coding” believed to be used in higher brain regions, in which only a small number of neurons are activated in any given moment. The sparse coding principal allows the company to retrace its platform’s path and give users the reasons behind its decisions.

As the company has matured, Wilson has stayed plugged in to the MIT community’s research, and Nara Logics participated in the STEX25 startup accelerator, run by the MIT Startup Exchange.

Leveraging a mind-like AI

Manufacturers are already using Nara Logics’ platform to better understand data from internet-of-things devices, consumer companies are using it to better connect with customers, and health care groups are using it to make better treatment decisions.

“We’re focused on a specific algorithm, which is the mechanics of decision making,” Wilson says. “We believe it’s something you can codify, and we believe it’s something that’ll be insanely valuable if you can get that process right.”

As Covid-19 disrupted industries and underscored the need for organizations to invest in adaptive software tools, Nara Logics nearly doubled its customer base. The founders are thrilled to be scaling a solution they feel is more collaborative and responsive to humans than other AI systems.

“We think the most important difference we’re contributing to is building an AI where people participate and people are in the loop — they’re cognizant and understanding and aware of what it’s doing,” Wilson says. “That helps them make smarter decisions every day, and those add up to make a big difference.”

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