viernes, 30 de julio de 2021

Apekshya Prasai receives 2021 Jeanne Guillemin Prize

Growing up in the periphery of the civil war in Nepal, Apekshya Prasai was exposed to a 10-year conflict that by some accounts left 19,000 people dead and 150,000 people internally displaced.

The insurgency was led by the Communist Party of Nepal-Maoists (CPN-M) with the aim of overthrowing the ruling monarchy and establishing a people’s republic. The war ended in 2016 under the auspices of the United Nations, and a peace treaty between the Nepalese government and the Maoist rebels.

“We lived in Kathmandu, the capital city, and were fortunate to be sheltered from most of the conflict and direct violence. But we were close enough to be aware of and concerned about what was happening in the countryside,” says Prasai.

Of the many related activities that were difficult for Prasai to make sense of at the time, she was particularly perplexed by the large numbers of women who joined the People’s War.

“Thousands of women were fighters, leaders, and in other kinds of support roles in this violent conflict. And given the deeply patriarchal nature of our society, I have always found this to be astounding.”

As a PhD candidate in the Department of Political Science, Prasai seeks to better understand this puzzling phenomenon and investigate the dynamics of women’s participation in conflict. Drawing on original data collected through fieldwork in Nepal and secondary data from across South Asia, Prasai’s dissertation analyzes the processes that trigger women’s inclusion in rebel organizations and examines how women themselves influence these processes.

Prasai is the recipient of this year’s Jeanne Guillemin Prize at the MIT Center for International Studies (CIS). Guillemin, a longtime colleague at CIS and senior advisor in the Security Studies Program, endowed the fund shortly before her death in 2019. An authority on biological warfare, Guillemin established the prize to help support female PhD candidates working in the field of security studies, which has long been dominated by men.

Like Guillemin, Prasai is committed to advancing women and other historically excluded groups in academia and has worked in various capacities to further this goal. In the past, she has chaired the Women in International Politics and Security working group at CIS — a network that supports women graduate students, fellows, and faculty in the greater Boston area. Prasai also served as gender and diversity co-chair in the political science department’s Graduate Student Council and was a member of its Diversity, Equity and Inclusion committee.

“The Guillemin prize is especially meaningful to me because Jeanne was not only an esteemed research scientist, but she was also passionate about supporting women. I share her commitment and feel humbled and honored that I could benefit from her generosity,” says Prasai.

From Nepal to MIT

Prasai left Nepal in 2012 for undergraduate studies in the United States at Bowdoin College. It was at Bowdoin that she was first exposed to political science and began noticing how coursework on politics and conflict, rarely, if ever, mentioned women.

“I was taking political science courses and noticed how discussions of wars, both interstate and civil wars, rarely mentioned women. This was odd given what I knew from the conflict in Nepal. So I became curious if women’s participation in violence was something unique to Nepal.”

Curiosity compelled her to explore the issue further. As early as her sophomore year, she delved into learning about women in conflict beyond the Nepal context. And, during a junior year abroad at Oxford University, she began exploring the role of women in resistance movements more broadly. The following summer, she got a grant from Bowdoin to conduct an independent study on women’s participation in violent movements across South Asia. This formed the basis of her undergraduate honors thesis on female suicide bombers.

The thesis left Prasai with more questions than answers and inspired her to pursue a doctoral degree at MIT.

“Broadly, my dissertation tries to shed light on the gender dimensions of civil wars. Specifically, I am trying to understand the processes that trigger women’s inclusion in male-dominated, rebel organizations operating in patriarchal communities. I am especially keen on exploring how women themselves influence these processes and aspire to bring otherwise-neglected women’s voices into the discourse on gender and civil wars.”

Prasai feels incredibly fortunate to be a part of the political science department and SSP community.

“I am grateful for the opportunity to learn from exceptionally talented faculty, fellows, and students, who are all doing creative and important research. And I am thankful for having the latitude to pursue research I care about while receiving excellent advising that helps me explore answers to questions that are meaningful to me in a manner that is both rigorous and relevant to the real world.”

For women’s sake

Prasai’s research has involved extensive fieldwork interviewing CPN-M members who participated in the People’s War and collecting primary documents back in Nepal.

She will apply the funds from the Guillemin prize toward additional fieldwork in Nepal. Although the Covid-19 pandemic has delayed her travel plans, she hopes to return by the end of this year. 

“Many of the women I have spoken to have never had an opportunity to put their experiences into words. They are often eager to tell their stories, which, along with their contributions to the movement, they hope will not be forgotten,” she explains. One of her dissertation goals is to try to shed light on these women’s experiences in the People’s War and help conserve some aspects of their history.

“As a Nepali woman, doing work that can help us understand women’s roles in a movement that changed the socio-political trajectory of Nepal and making even a small contribution towards conserving their history, holds great meaning to me and many in my community,” she says. “And I am thankful for support from the Guillemin Prize, which will allow me to continue this work.”



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Advancing industry convergence through technology and innovation

Launched in October 2020, the MIT and Accenture Convergence Initiative for Industry and Technology is intended to demonstrate how the convergence of industries and technologies is powering the next wave of change and innovation. The five-year initiative is designed to advance three main pillars: research, education, and fellowships. As part of the third pillar, Accenture has awarded five fellowships to MIT graduate students working on research in industry and technology convergence who are underrepresented, including by race, ethnicity and gender.  
 
The recipients of the inaugural Accenture Fellows program are working across disciplines including electronics, textiles, machine learning, economics, and supply chain. Their research has the potential to advance innovation and technology to influence industry convergence and to broaden the convergence process to virtually all industries — through creative problem-solving, the accelerated adoption of new technologies, unique collaborations, and thinking imaginatively and boldly. 
 
“Accenture has long focused on how creativity and ingenuity can help solve some of the world’s most complex problems. When we wanted to explore the convergence of industry and technology, we turned to MIT to extend our longstanding partnership with education, research, and fellowships that delved deeper into this topic,” says Sanjeev Vohra, global lead of applied intelligence at Accenture. “The Accenture Fellows awards underscore our strong commitments to education, innovation, research and discovery, and creating opportunities that will help accelerate the achievements of these future champions of change.”
 
Research being conducted by the fellows covers an array of critical work, including: developing robot-aided therapy to improve balance in impaired subjects; leveraging the increasing availability of data in the gig economy; using machine learning to process locally generated waste for use as alternative energy in low-income municipalities; examining operational challenges that may arise from barriers to extending credit and sharing information among supply chain partners; and designing and applying electronic textile technology to low-Earth orbit, prompting an opportunity for convergence among the electronics, textile, and space technology industries.
 
“These fellows are prime examples of the incredible cross-disciplinary work happening at the nexus of industry and technology,” says Anantha Chandrakasan, dean of the MIT School of Engineering and the Vannevar Bush Professor of Electrical Engineering and Computer Science. “We are tremendously grateful for Accenture’s commitment to our students, and for their goal of supporting and advancing student innovation and discovery through these fellowships.”
 
Student nominations from each unit within the School of Engineering, as well as from the four other MIT schools and the MIT Schwartzman College of Computing, were invited as part of the application process. Five exceptional students were selected as the inaugural fellows of the initiative:
 
Jacqueline Baidoo is a PhD student in the Department of Materials Science and Engineering, exploring policy related to materials use. Specifically, her research is focused on waste-to-energy (WTE) strategies that could be adopted at the municipal level to treat and process locally generated waste for use as alternative energy. Her goal is to use machine learning to reduce the barrier to entry of WTE practices in low-income municipalities through the development of a tool that informs municipal decisions around waste management and the construction of WTE facilities. Baidoo earned a BS in chemistry and BA in physics from Xavier University of Louisiana and a BS in chemical and biomolecular engineering from Georgia Tech.
 
Juliana Cherston is PhD student in the Media Lab. Her work in the Responsive Environments Group is focused on bringing electronic textile technology to low-Earth orbit, prompting an opportunity for convergence among the electronics, textile, and space technology industries. Specifically, she is augmenting large area space fabrics with active sensory functionality, weaving vibration-sensitive piezoelectric fibers and charge-sensitive conductive yarns into these specialized materials. Cherston earned a BA in physics and computer science from Harvard University.
 
Olumurejiwa Fatunde is a PhD student studying in the Center for Transportation and Logistics. Her research examines operational challenges that may arise from barriers to extending credit and sharing information among supply chain partners in informal settings. With the proliferation of novel payment platforms, cryptocurrency usage, and natural language processing, Fatunde postulates that there is an opportunity to drive convergence across financial services, telecommunications, and other customer-facing industries in emerging markets. Specifically, she is investigating how technologies could trickle down to the smallest, least-formal organizations, helping them to create value for consumers and to be a part of the global economy. Fatunde earned a BA in biomedical engineering from Harvard University and an MS in international health policy from the London School of Economics in the U.K.
 
André Medeiros Sztutman is a PhD student in the Department of Economics. Leveraging the increasing availability of data in the gig economy, his work focuses on the development of tools for tackling adverse selection in insurance markets. By creating tools that make better use of information — especially in situations where it is particularly needed — he is contributing to the convergence of different industries: gig platforms, reporting agencies, and the insurance business. Medeiros Sztutman earned a BS in economics from the Universidade de Sao Paulo, Brazil and an MS in economics from Pontificia Universidade Catolica do Rio de Janeiro in Brazil.
 
Kaymie Shiozawa '19 is a master’s student in the Department of Mechanical Engineering, exploring how robot-aided therapy could potentially address the challenge of improving balance in impaired subjects. Drawing on her experience designing human subject experiments, applying machine learning and mathematical simulations, and designing complex mechanisms for robotics and medical devices, Shiozawa aims to design a variable impedance cane and a novel protocol known as AdaptiveCane, which encourages unaided balance by progressively reducing the level of assistance provided as a user’s performance improves. Shiozawa earned an BS in mechanical engineering from MIT.



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jueves, 29 de julio de 2021

Teenage MIT ninja students

Guang Cui and Daniel Sun are members of the class of 2022, course 6.3 (Computer Science and Engineering) majors, former roommates, best friends — and now, alumni of the long-running TV competition “American Ninja Warrior.” The episode in which they debuted (season 13, night 4 of qualifiers) as first-time competitors recently aired on NBC, and is available on several streaming services. They spoke recently about what it takes to be a ninja.

Q: How did you decide to try for this goal — were you both already fans of “American Ninja Warrior”?

Dan: Guang and I met in CPW [Campus Preview Weekend] and bonded almost immediately. We shared lots of things in common, and one of them was watching “American Ninja Warrior,” or ANW, since we were kids. When we met, we were both 18 and thought, “Wouldn’t it be cool if we tried to be on the show?” But the lower age limit to apply was 21. We spent our freshman year together in Chicago, participating in an internship at Akuna Capital. While we were there, we picked up bouldering as a pastime. A lot of the skills involved in bouldering are transferable to ANW, so when they lowered the age restriction for application from 21 to 18, we decided we should apply. We applied in 2019 for the 2020 season and were rejected, but we tried again the next year and ended up on the show.

Guang: Personally, I remember being about 5 years old, in the lobby of my apartment building, watching the original Japanese version of the show, “Sasuke.” We all watched ANW growing up, so when Dan and I met in freshman year and immediately had conversations about all the big-name ninjas and who we thought was the best, I knew we were going to be close.

Dan: My parents would always chastise me for climbing on things in the house, trying to do random tricks — a big one was doing pull-ups on door frames. My parents would always be upset, thinking I was going to break the door frames, but now I see that as me getting started with the training relatively early.

Guang: It was the same with me, though I don’t think I could do pull-ups on the door frames until high school. But I could do spider climbs on door frames starting when I was about 9 years old, and, like Dan’s, my parents would get mad at me.

Q: Athletic training during any Boston winter is hard — but it must have been doubly so during Covid. How did you stay safe while you trained?

Dan: During the early days we were both at home, and very early on we realized that there was really no way to safely go to the gym. The first thing I ordered was a pull-up bar so I could do exercises like calisthenics and body weight stuff. Trying to come up with exercises we could do was challenging.

Guang: At home, I also did a lot of calisthenics and other random exercises using makeshift materials. I made a random YouTube video of me working out and doing ninja stuff at home. Once we were allowed to attend socially distanced gyms, I went to the rock-climbing gym with my mask on. I got tested a lot in the late summer. We kept each other updated with training; I would text Dan the hard rock-climbing problems I encountered. In spring, when we got back onto campus, that’s when we got the surprise call that we would be on the show. After that, we would go to the ninja gym multiple times every week, as well as training in the Z Center. We would get a Zipcar and go to the ninja gyms out in Boston and Wellesley, train for two hours in the evening, then get home and rest. We blew through a thousand dollars in Zipcar costs … but it was absolutely worth it.

Q: What’s it like to go behind the scenes of the set — were there any surprises?

Dan: One memory that comes to mind is when we were on the buses to go to the actual competition. I didn’t know any of the ninjas that were there on my bus, and then this one guy in a hoodie and beanie, sipping tea, sits down next to me. He starts talking to the guy behind me about the obstacles, like, “What do you think we’re gonna have?” And I leaned in to join the conversation. As I’m introducing myself, the guy pulls back his hoodie — and it’s David Campbell, the “Godfather,” who has competed in literally every ANW competition. I’ve seen him in every season since I was a little kid. He gave me a bunch of advice for being in my rookie season. It’s surreal to see people you’ve just seen on TV, and I’ll say that I really like the people in the ninja community — they’re really friendly and open to talking, and they lead interesting lives.

Guang: I totally agree. Interacting with people whom we’ve seen as celebrities for so long is crazy. To realize that we’re running the same course is still wild to me. We were playing instruments in the office there, and [retired NFL player] Andrew East walked by and said, “You sound nice!” There are people from all walks of life who participate, and since we’re normally surrounded by other college students, it was great to have the opportunity to learn from them.

Q: When did you learn which challenges you’d be facing, and how did you mentally prepare? Emotionally?

Guang: You don’t learn the obstacles until the day of filming; it was like maybe an hour or two, max, before we ran the course. They took us through and told us the rules, and then we were just thinking about how to go through, engaging in mental visualization and strategizing.

The only exception to the surprises are the first and last obstacle, which are usually the same. The last obstacle is always the Warped Wall, so we’d practice that a lot. Recently, the first obstacle has been the wobble steps, followed a rope to the platform. I was weirdly really nervous about the first obstacle! The day before we had to leave for Seattle, I put five books in the hallway and strode across them just to prepare; Dan came out and laughed at me. I was being dumb, but it was good practice.

Q: Tell us about the actual, physical experience of going through the course.

Guang: I would say it obviously creates a lot of nerves, because you only get to do it once a year. I took a lot of deep breaths and tried to zone in, and live in the moment. Physically, I think my training helped a lot; I didn’t feel too tired after any one obstacle. It’s like riding a roller coaster but a lot better. In the moment, it’s just so fun — it’s like play.

Dan: I remember that backstage, in the warm-up area, there were these bars for infrastructure to hold up some posters, and the other ninjas were doing pull-ups and warmups on those bars. They’d set up some crash pads, so after we got a glimpse of the obstacles, we were trying to mimic them by swinging around on the support bars.

Q: Do you think being a scientist is beneficial to being a ninja — and if so, how?

Dan: There’s definitely things that carry over; the discipline and training it takes to be a ninja is very similar to discipline in studying. Like achieving anything in life, you have to put in the hours, effort, and training, to get to where you want to be. You have to eat healthy and work on your body in order to be at peak performance. Mental preparation translates well, too; we both did a lot of academic competitions back in high school, and a lot of that mindset translates. You have to be completely zoned in and focused on the question at hand in order to make progress on the problem. That “in the zone” feeling is very similar across both kinds of challenge.

Guang: One area where the experience doesn’t translate is when the announcers say things like “as scientists, you should be able to calculate the trajectory of the needed movement” … well, no. There are a few cases where knowing the physics of an obstacle can sort of help — for instance, knowing that if you spread your legs out, you have a greater chance of completing the obstacle. But the actual experience of being on the obstacle helps way more. I’m glad we had the opportunity to do this challenge that is totally different than either computer science or electrical engineering. It’s nice to play on obstacles when I’m burnt out from writing code. It balances my life.

Q: How has this experience changed you? 

Dan: The first thing both of us said after it was over was, “We have to run it back next year; we’ll be back.” Surface-level, it was cool to learn about how TV is made. We realized a lot of things can be scripted or filmed hundreds of times until they get it right. Additionally, it was a great learning experience for figuring out how I act in high-pressure scenarios — “American Ninja Warrior” was by far the biggest stage I’ve ever been on, which is kind of bizarre because I feel like I have other strengths as well, and I would have expected to be showcasing those! It’s not that Ninja is my weakest side, exactly, but it was cool to be able to showcase that athletic side of myself on the biggest stage.

Guang: I learned a little about what I was capable of. If you’d asked me three years ago if I would be on the show, I would have been pretty surprised. As Dan said, we would have been less surprised if we’d done something remarkable in the sciences. I don’t think the experience fundamentally changed us as people; we had this one moment on TV. It’s just a neat moment in our lives. Also, Dan and I were best friends before ANW, but this experience has brought us even closer, which was really great.  

Q: Do you plan to try to start a ninja community at MIT? 

Guang: Actually, yes! We’ve been talking about trying to get a ANW club started, apply through MIT and maybe make it official soon.



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Inaugural fund supports early-stage collaborations between MIT and Jordan

MIT International Science and Technology Initiatives (MISTI), together with the Abdul Hameed Shoman Foundation (AHSF), the cultural and social responsibility arm of the Arab Bank, recently created a new initiative to support collaboration with the Middle East. The MIT-Jordan Abdul Hameed Shoman Foundation Seed Fund is providing awardees with financial grants up to $30,000 to cover travel, meeting, and workshop expenses, including in-person visits to build cultural and scientific connections between MIT and Jordan. MISTI and AHSF recently celebrated the first round of awardees in a virtual ceremony held in Amman and the United States.

The new grant is part of the Global Seed Funds (GSF), MISTI's annual grant program that enables participating teams to collaborate with international peers, either at MIT or abroad, to develop and launch joint research projects. Many of the projects funded lead to additional grant awards and the development of valuable long-term relationships between international researchers and MIT faculty and students.

Since MIT's first major collaboration in the Middle East in the 1970s, the Institute has deepened its connection and commitment to the region, expanding to create the MIT-Arab World program. The MIT-Jordan Abdul Hameed Shoman Foundation Seed Fund enables the MIT-Arab World program to move forward on its key objectives: build critical cultural and scientific connections between MIT and the Arab world; develop a cadre of students who have a deep understanding of the Middle East; and bring tangible value to the partners in the region.

Valentina Qussisiya, CEO of the foundation, shared the importance of collaboration between research institutes to improve and advance scientific research. She highlighted the role of AHSF in supporting science and researchers since 1982, emphasizing, "The partnership with MIT through the MISTI program is part of AHSF commitment toward this role in Jordan and hoped-for future collaborations and the impact of the fund on science in Jordan."

The new fund, open to both Jordanian and MIT faculty, is available to those pursuing research in the following fields: environmental engineering; water resource management; lean and modern technologies; automation; nanotechnology; entrepreneurship; nuclear engineering; materials engineering; energy and thermal engineering; biomedical engineering, prostheses, computational neuroscience, and technology; social and management sciences; urban studies and planning; science, technology, and society; innovation in education; Arabic language automation; and food security and sustainable agriculture.

Philip S. Khoury, faculty director of MISTI's MIT-Arab World program and Ford International Professor of History and associate provost at MIT, explained that the winning projects all deal with critical issues that will benefit both MIT and Jordan, both on- and off-campus. "Beyond the actual faculty collaboration, these projects will bring much value to the hands-on education of MIT and Jordanian students and their capacity to get to know one another as future leaders in science and technology," he says.

This year, the MIT-Jordan Abdul Hameed Shoman Foundation Seed Fund received numerous high-quality proposals. Applications were reviewed by MIT and Jordanian faculty and selected by a committee of MIT faculty. There were six winning projects in the inaugural round:

  • Low-Cost Renewable-Powered Electrodialysis Desalination and Drip Irrigation: Amos Winter (MIT principal investigator) and Samer Talozi (international collaborator)
  • iPSC and CRISPR Gene Editing to Study Rare Diseases: Ernest Fraenkel (MIT principal investigator) and Nidaa Ababneh (international collaborator)
  • Use of Distributed Low-Cost Sensor Networks for Air Quality Monitoring in Amann: Jesse Kroll (MIT principal investigator) and Tareq Hussein (international collaborator)
  • Radiation Effects on Medical Devices Made by 3D Printing: Ju Li (MIT principal investigator) and Belal Gharaibeh (international collaborator)
  • Superprotonic Conductivity in Metal-Organic Frameworks for Proton-Exchange Membrane Fuel Cells: Mircea Dinca (MIT principal investigator) and Kyle Cordova (international collaborator)
  • Mapping Urban Air Quality Using Mobile Low-cost Sensors and Geospatial Techniques: Sarah Williams (MIT principal investigator) and Khaled Hazaymeh (international collaborator)

The goal of these funded projects is for researchers and their students to form meaningful professional partnerships across cultures and leave a lasting impact upon the scientific communities in Jordan and at MIT.

"[The fund will] enhance the future career prospects of emerging scholars from both countries," said awardee Professor Kyle Cordova, executive director for scientific research at Royal Scientific Society and assistant to Her Royal Highness Princess Sumaya bint El Hassan for scientific affairs. "Our young scholars will gain a unique perspective of the influence of different cultures on scientific investigation that will help them to function effectively in a multidisciplinary and multicultural environment."



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A sleep study’s eye-opening findings

Subjectively, getting more sleep seems to provide big benefits: Many people find it gives them increased energy, emotional control, and an improved sense of well-being. But a new study co-authored by MIT economists complicates this picture, suggesting that more sleep, by itself, isn’t necessarily sufficient to bring about those kinds of appealing improvements.

The study is based on a distinctive field experiment of low-income workers in Chennai, India, where the researchers studied residents at home during their normal everyday routines — and managed to increase participants’ sleep by about half an hour per night, a very substantial gain. And yet, sleeping more at night did not improve people’s work productivity, earnings, financial choices, sense of well-being, or even their blood pressure. The only thing it did, apparently, was to lower the number of hours they worked.

“To our surprise, these night-sleep interventions had no positive effects whatsoever on any of the outcomes we measured,” says Frank Schilbach, an MIT economist and co-author of a new paper detailing the study’s findings.

There is more to the matter: For one thing, the researchers found, short daytime naps do help productivity and well-being. For another thing, participants tended to sleep at night in difficult circumstances, with many interruptions. The findings leave open the possibility that helping people sleep more soundly, rather than just adding to their total amount of low-grade sleep, could be useful. 

“People’s sleep quality is so low in these circumstances in Chennai that adding sleep of poor quality may not have the benefits that another half hour of sleep would have if it’s of higher quality,” Schilbach suggests.

The paper, “The Economic Consequences of Increasing Sleep Among the Urban Poor,” is published in the August issue of The Quarterly Journal of Economics. The authors of the paper are Pedro Bessone PhD ’21, a recent graduate from MIT’s Department of Economics; Gautam Rao, an associate professor of economics at Harvard University; Schilbach, who is the Gary Loveman Career Development Associate Professor of Economics at MIT; Heather Schofield, an assistant professor in the Perelman School of Medicine and the Wharton School at the University of Pennsylvania; and Mattie Toma, a PhD candidate in economics at Harvard University.

Sleeping on rickshaws

Schilbach, a development economist, says the genesis of the study came from other research he and his colleagues have done in settings such as Chennai — during which they have observed that low-income people tend to have difficult sleeping circumstances in addition to their other daily challenges. 

“In Chennai, you can see people sleeping on their rickshaws,” says Schilbach, who is also a faculty affiliate at MIT’s Abdul Latif Jameel Poverty Action Lab (J-PAL). “Often, there are four or five people sleeping in the same room where it’s loud and noisy, you see people sleep in between road segments next to a highway. It’s incredibly hot even at night, and there are lots of mosquitos. Essentially, in Chennai, you can find any potential irritant or adverse sleep factor.”

To conduct the study, the researchers equipped Chennai residents with actigraphs, wristwatch-like devices that infer sleep states from body movements, which allowed the team to study people in their homes. Many other sleep studies observe people in lab environments.

The study examined 452 people over a month. Some people were given encouragement and tips for better sleep; others received financial incentives to sleep more. Some members of both those groups also took daytime naps, to see what effect that had.

The participants in the study were also given data-entry jobs with flexible hours while the experiment was taking place, so the researchers could monitor the effects of sleep on worker output and earnings in a granular way.

Overall, the Chennai study’s participants had been averaging about 5.5 hours of sleep per night before the intervention, and added 27 minutes of sleep per night on average. However, in order to gain those 27 minutes, the participants were in bed an extra 38 minutes per night. That speaks to the challenging sleep circumstances of the participants, who on average woke up 31 times per night.

“A key thing that stands out is that people’s sleep efficiency is low, that is, their sleep is heavily fragmented,” Schilbach says. “They have extremely few periods experiencing what’s thought to be the restorative benefits of deep sleep. … People’s sleep quantity went up due to the interventions, because they spent more time in bed, but their sleep quality was unchanged.”

That could be why, across a wide range of metrics, people in the study experienced no positive changes after sleeping more. Indeed, as Schilbach notes, “We find one negative effect, which is on hours worked. If you spend more time in bed, then you have less time for other things in your life.”

On the other hand, study participants who were allowed to nap while on the data-entry job did fare better in several measured categories.

“In contrast to the night sleep intervention, we find clear evidence of naps improving a range of outcomes, including their productivity, their cognitive function, and their psychological well-being, as well as some evidence on savings,” Schilbach says. “These two interventions have different effects.”

That said, naps only increased total income when compared to workers who took a break instead. Naps did not increase the total income of workers — nappers were more productive per minute worked but spent less time actually working.

“It’s not the case that naps just pay for themselves,” Schilbach says. “People don’t actually stay longer in the office when they nap, presumably because they have other things to do, such as taking care of their families. If people nap for about half an hour, their hours worked falls by almost half an hour, almost a one-to-one ratio, and as a result, people’s earnings in that group are lower.”

Valuing sleep as an end in itself

Schilbach says he hopes that other researchers will dig into some of the further questions the study raises. Further work, for instance, could attempt to change the sleeping circumstances of low-income workers to see if better sleep quality, not just increased sleep quantity, makes a difference.

Schilbach also suggests it may be important to better understand the psychological challenges the poor face when it comes to sleep.

“Being poor is very stressful, and that might interfere with people’s sleep,” he notes. “Addressing how environmental and psychological factors affect sleep quality is something worth examining.”

Moreover, using actigraph technology and other devices, Schilbach notes, it should be possible to generate in increased number of studies that capture people’s sleep patterns in their normal home environments, not just medical settings.

“There’s not a lot of work studying people’s sleep in their everyday lives,” Schilbach says. “And I really hope people will study sleep more in developing countries and poor countries, focusing on outcomes that people value.”

For his part, Schilbach says he is interested in continuing work on sleep that is set in the U.S., not just in India, where he has conducted much of his research. In any setting, he says, we should take the issue of sleep seriously as an element of anti-poverty research and public policy — and as an important element of well-being in its own right.

“Sleep might be important as an avenue for improved productivity or other types of choices people make,” Schilbach says. “But I think a good night’s sleep is also important in and of itself. We should value being able to afford to sleep well and not be worried at night. Poverty indices are about income and material consumption. But now that we can measure sleep better, a good night’s sleep should be part of a more comprehensive measure of people’s well-being. I hope that’s where we’re going eventually.”



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Jing Wang, professor of Chinese media and cultural studies, dies at 71

Jing Wang, the S.C. Fang Professor of Chinese Languages and Culture, and a longtime member of the MIT faculty in Global Studies and Languages and Comparative Media Studies/Writing, passed away on Sunday in Boston after a heart attack.

For decades, Wang was a leading scholar of the intersection of media and activism in China. Following a bachelor’s degree at National Taiwan University, she studied comparative literature at the University of Michigan and then at the University of Massachusetts, where she earned her PhD. She continued her focus on literature at Duke University, where she was faculty for 16 years and authored her first books. 1992’s The Story of Stone, which was awarded a Joseph Levenson Book Prize for the year’s best book on premodern China, explored traditional Chinese literature, but her next book, High Culture Fever: Politics, Aesthetics, and Ideology in Deng’s China (1996), marked a move toward her study of Chinese media more broadly.

Her subsequent work, both as a scholar and nonprofit leader, sought ways to empower Chinese grassroots organizations, particularly within the context of digital and social media literacy. Though she perhaps became best known for her 2009 book Brand New China on advertising and Chinese commercial culture, she was also at the time writing and presenting about a new project, the nonprofit NGO2.0. She and China-based collaborators launched it to help local organizers use social media to be change agents in a country where social media is often held suspect. “She was my esteemed mentor and also great friend,” says Rongting Zhou, a professor at China’s University of Science and Technology who came to MIT as a visiting scholar in 2007 and later helped Wang develop NGO2.0. “She and I overcame many difficulties and made remarkable achievements in China.”

Wang’s turn to an academic look at Chinese activism was reflected in her most recent book, The Other Digital China: Nonconfrontational Activism on the Social Web (2019), that one reviewer called “a way forward for those in China — and perhaps elsewhere — who want to make progress within a totalitarian state.” She had readers come away understanding that activists in China are savvy actors, not stuck with a choice between full acquiescence or resistance.

She joined the MIT faculty in 2001, as a professor in the Foreign Languages and Literatures (FL&L) section of the School of Humanities, Arts, and Social Sciences, and soon found a second home in the Comparative Media Studies section. She served as FL&L’s head from 2005 to 2008. The CMS position later became a joint and then primary appointment. She had a profound impact within MIT. Her signature subject, “Advertising and Media: Comparative Perspectives,” enrolled nearly 300 undergraduate and graduate students since Wang developed it in 2002. She was an advisor or committee chair for eight CMS master’s theses, and she served for years as the Chinese minor advisor. And her service on dozens of departmental and Institute-level committees aided with everything from increasing faculty diversity to the essential smooth running of academic programs.

“Professor Wang was my beloved mentor at CMS — a mentor to academics, entrepreneurship, and life,” says Han Su SM ’20, one of Wang’s advisees. “Though I have left school, the mentorship I received from Jing will stay for a lifetime. Though Jing has left us, her wisdom and courageousness will forever live with us and constantly inspire us to fight for the greater good.” Another 2020 CMS master’s program alum, Iago Bojczuk, wrote in a tribute on Facebook, “I tried to learn as much as I could from her as I navigated the obscure rules of grad school as an international student. She often would encourage me to do things differently and not necessarily follow the standard pathway that seemed obvious. I felt she understood me and the hybrid worldviews and lived experiences that shaped me.”

Her contributions to MIT — and academia generally — didn’t go unnoticed. Wang received fellowships, grants, and other honors from the Radcliffe Institute for Advanced Study, the Chinese Ministry of Education, the Ford Foundation, and even her students in the form of MIT’s Levitan Award for Excellence in Teaching. In the nomination letter for the Levitan Award, a student wrote that “Professor Wang consistently challenges our viewpoints and ideologies and makes us think more profoundly about Chinese culture and history. She has reawakened a curiosity for cultural understanding and new perspectives that I have only ever experienced abroad and I am so grateful to have that joy for something other than technical engineering.”

Beyond that, though, she will be remembered for her care for others. She hosted Chinese students at her house each Thanksgiving. She raised money for an artist travel fund set up in memory of her late daughter Candy. And she served as a professional advocate for so many in the MIT community. “Jing was an incredible colleague, mentor, and friend to so many,” says professor of comparative media studies T.L. Taylor. “I often think about how she would host dinners for students, friends, and colleagues during the holidays when people might find themselves on their own. Her thoughtfulness and generosity was something I deeply admired.” Likewise, part of her institutional legacy is as a hiring or promotion committee member for Comparative Media Studies/Writing colleagues Ian Condry, Paloma Duong, and Paul Roquet. In response to news of her death, Professor Condry said that “Jing was a model friend and academic, a force of nature who tackled all projects with integrity, compassion, and commitment.”

Professor Emma Teng, director of MIT Global Languages, knew Wang since Teng herself was a child. She echoed others' sentiments: “Jing was a warm, generous, caring person, fierce in fighting for causes she believed in and for the less advantaged. She was a dedicated mentor to so many of us, and cared deeply about social justice for Asian Americans.”

Wang's personal interests included cooking, Chinese zither, gardening, and the spiritual practice of Tibetan Buddhism. She was also deeply dedicated to philanthropic causes in China.

Information about a memorial will be shared when it is available. ​​Those looking for a way to honor Professor Wang’s memory are encouraged to donate to the Candy R. Wei International Travel Endowment Fund, which Wang established in memory of her daughter. Learn more at candywei.org



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miércoles, 28 de julio de 2021

Geologists take Earth’s inner temperature using erupted sea glass

If the Earth’s oceans were drained completely, they would reveal a massive chain of undersea volcanoes snaking around the planet. This sprawling ocean ridge system is a product of overturning material in the Earth’s interior, where boiling temperatures can melt and loft rocks up through the crust, splitting the sea floor and reshaping the planet’s surface over hundreds of millions of years.

Now geologists at MIT have analyzed thousands of samples of erupted material along ocean ridges and traced back their chemical history to estimate the temperature of the Earth’s interior.

Their analysis shows that the temperature of the Earth’s underlying ocean ridges is relatively consistent, at around 1,350 degrees Celsius — about as hot as a gas range’s blue flame. There are, however, “hotspots” along the ridge that can reach 1,600 degrees Celsius, comparable to the hottest lava.

The team’s results, appearing today in the Journal of Geophysical Research: Solid Earth, provide a temperature map of the Earth’s interior around ocean ridges. With this map, scientists can better understand the melting processes that give rise to undersea volcanoes, and how these processes may drive the pace of plate tectonics over time.

“Convection and plate tectonics have been important processes in shaping Earth history,” says lead author Stephanie Brown Krein, a postdoc in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). “Knowing the temperature along this whole chain is fundamental to understanding the planet as a heat engine, and how Earth might be different from other planets and able to sustain life.”

Krein’s co-authors include Zachary Molitor, an EAPS graduate student, and Timothy Grove, the R.R. Schrock Professor of Geology at MIT.

A chemical history

The Earth’s interior temperature has played a critical role in shaping the planet’s surface over hundreds of millions of years. But there’s been no way to directly read this temperature tens to hundreds of kilometers below the surface. Scientists have applied indirect means to infer the temperature of the upper mantle — the layer of the Earth just below the crust. But estimates thus far are inconclusive, and scientists disagree about how widely temperatures vary beneath the surface.

For their new study, Krein and her colleagues developed a new algorithm, called ReversePetrogen, that is designed to trace a rock’s chemical history back in time, to identify its original composition of elements and determine the temperature at which the rock initially melted below the surface.

The algorithm is based on years of experiments carried out in Grove’s lab to reproduce and characterize the melting processes of the Earth’s interior. Researchers in the lab have heated up rocks of various compositions, reaching various temperatures and pressures, to observe their chemical evolution. From these experiments, the team has been able to derive equations — and ultimately, the new algorithm — to predict the relationships between a rock’s temperature, pressure, and chemical composition.

Krein and her colleagues applied their new algorithm to rocks collected along the Earth’s ocean ridges — a system of undersea volcanoes spanning more than 70,000 kilometers in length. Ocean ridges are regions where tectonic plates are spread apart by the eruption of material from the Earth’s mantle — a process that is driven by underlying temperatures.

“You could effectively make a model of the temperature of the entire interior of the Earth, based partly on the temperature at these ridges,” Krein says. “The question is, what is the data really telling us about the temperature variation in the mantle along the whole chain?”

Mantle map

The data the team analyzed include more than 13,500 samples collected along the length of the ocean ridge system over several decades, by multiple research cruises. Each sample in the dataset is of an erupted sea glass — lava that erupted in the ocean and was instantly chilled by the surrounding water into a pristine, preserved form.

Scientists previously identified the chemical compositions of each glass in the dataset. Krein and her colleagues ran each sample’s chemical compositions through their algorithm to determine the temperature at which each glass originally melted in the mantle.

In this way, the team was able to generate a map of mantle temperatures along the entire length of the ocean ridge system. From this map, they observed that much of the mantle is relatively homogenous, with an average temperature of around 1,350 degrees Celsius. There are however, “hotspots,” or regions along the ridge, where temperatures in the mantle appear significantly hotter, at around 1,600 degrees Celsius.

“People think of hotspots as regions in the mantle where it’s hotter, and where material may be melting more, and potentially rising faster, and we don’t exactly know why, or how much hotter they are, or what the role of composition is at hotspots,” Krein says. “Some of these hotspots are on the ridge, and now we may get a sense of what the hotspot variation is globally using this new technique. That tells us something fundamental about the temperature of the Earth now, and now we can think of how it’s changed over time.”

Krein adds: “Understanding these dynamics will help us better determine how continents grew and evolved on Earth, and when subduction and plate tectonics started — which are critical for complex life.”

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



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Robert Logcher, professor emeritus of civil and environmental engineering, dies at 85

MIT Professor Emeritus Robert D. Logcher ’58, SM ’60, SCD ’62, an accomplished civil and environmental engineer who helped advance the field with computational techniques, passed away peacefully on July 20. He was 85.

Logcher served as a faculty member in the Department of Civil and Environmental Engineering from 1962 to 1996, and was an early pioneer of the computer programming systems used in structural design. He developed STRESS (STRuctural Engineering Systems Solver) and STRUDL (STRUctural Design Language), which were part of the Integrated Civil Engineering System (ICES) used for civil engineering practices and teaching. Logcher was also a key member of the ICES Architecture Group that designed the computer operating system. Beyond the department, he was also a key participant in Project MAC (Multiple Access Computer), the pioneering MIT time-sharing system. 

Logcher led the department in new directions when he initiated the project management program in civil engineering and construction management.

Born in the Hague, Netherlands on Dec. 27, 1935, Logcher first arrived at MIT as an undergraduate in 1954. In addition to studying civil engineering, Logcher was an avid sailor and his passion for sailing would carry him throughout his career and into retirement. When asked about his post-retirement plans, they were to “sail the seven seas.” 

After receiving his bachelor’s degree from MIT in 1958 and going on to pursue his master’s and doctoral degree in civil engineering at the Institute, he was awarded two graduate fellowships from the National Science Foundation. He became assistant professor in the Department of Civil and Environmental Engineering shortly after receiving his doctoral degree in 1962 and later became full professor in 1975. Some of his earliest research contributed to the pioneering structural design programming language that is still being used in the field today. 

MIT professor emeritus of civil and environmental engineering Daniel Roos, who led the ICES Architecture group, where Logcher was a member, remembers him fondly as an engineer and colleague.

"Bob Logcher had a lasting impact on the civil engineering profession with the development of STRUDL in the mid-1960s, a computer-based design system for structural engineering,” says Roos. “That system is still in widespread use today. A new version was released in 2020, over 50 years after its creation. That is a remarkable achievement."

Over the span of his career, Logcher’s research into computational applications and methods for structural engineering attracted the interest of the international community. He attended conference proceedings around the world, and his papers were cited and published among the top engineering journals and international conferences. 

With colleagues Roos and the late Professor Emeritus Joseph Sussman as partners, he founded Engineering Computer International (ECI) in Bedford, Massachusetts, in 1965. A consulting firm that advised large engineering firms around the world about how to use computer systems in their practice, ECI expanded into Multisystems, Inc. in Cambridge, Massachusetts, where he was also a senior consultant from 1969 to 1985.  

Logcher was honored with the Moisseiff Award for his contribution to the science of structural design and was a member of the American Society of Civil Engineers, Boston Society of Civil Engineers, National Society of Professional Engineers, and Massachusetts Society of Professional Engineers. 

Logcher led a rich life outside of his academic one. Known as “Bob” to his friends, Logcher enjoyed skiing and backpacking, and classical and folk music. He bought his first sailboat in 1973 and this became his passion that he shared with his wife, Chesley. Their fourth boat was purchased to “sail the seven seas”; however, they enjoyed the Bahamas so much that they continued traveling there for 20 years.

Logcher is survived by his wife, Chesley; children Suzanne, Erica, and Daniel; and four grandchildren. A celebration of Logcher's life will be held at a later date. Gifts in Logcher’s memory may be made to the Robert D. Logcher (1958) Travel Fund.



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A new way to detect the SARS-CoV-2 Alpha variant in wastewater

Researchers from the Antimicrobial Resistance (AMR) interdisciplinary research group at the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, alongside collaborators from Biobot Analytics, Nanyang Technological University (NTU), and MIT, have successfully developed an innovative, open-source molecular detection method that is able to detect and quantify the B.1.1.7 (Alpha) variant of SARS-CoV-2. The breakthrough paves the way for rapid, inexpensive surveillance of other SARS-CoV-2 variants in wastewater.

As the world continues to battle and contain Covid-19, the recent identification of SARS-CoV-2 variants with higher transmissibility and increased severity has made developing convenient variant tracking methods essential. Currently, identified variants include the B.1.17 (Alpha) variant first identified in the United Kingdom and the B.1.617.2 (Delta) variant first detected in India.

Wastewater surveillance has emerged as a critical public health tool to safely and efficiently track the SARS-CoV-2 pandemic in a non-intrusive manner, providing complementary information that enables health authorities to acquire actionable community-level information. Most recently, viral fragments of SARS-CoV-2 were detected in housing estates in Singapore through a proactive wastewater surveillance program. This information, alongside surveillance testing, allowed Singapore’s Ministry of Health to swiftly respond, isolate, and conduct swab tests as part of precautionary measures.

However, detecting variants through wastewater surveillance is less commonplace due to challenges in existing technology. Next-generation sequencing for wastewater surveillance is time-consuming and expensive. Tests also lack the sensitivity required to detect low variant abundances in dilute and mixed wastewater samples due to inconsistent and/or low sequencing coverage.

The method developed by the researchers is uniquely tailored to address these challenges and expands the utility of wastewater surveillance beyond testing for SARS-CoV-2, toward tracking the spread of SARS-CoV-2 variants of concern.

Wei Lin Lee, research scientist at SMART AMR and first author on the paper adds, “This is especially important in countries battling SARS-CoV-2 variants. Wastewater surveillance will help find out the true proportion and spread of the variants in the local communities. Our method is sensitive enough to detect variants in highly diluted SARS-CoV-2 concentrations typically seen in wastewater samples, and produces reliable results even for samples which contain multiple SARS-CoV-2 lineages.”

Led by Janelle Thompson, NTU associate professor, and Eric Alm, MIT professor and SMART AMR principal investigator, the team’s study, “Quantitative SARS-CoV-2 Alpha variant B.1.1.7 Tracking in Wastewater by Allele-Specific RT-qPCR” has been published in Environmental Science & Technology Letters. The research explains the innovative, open-source molecular detection method based on allele-specific RT-qPCR that detects and quantifies the B.1.1.7 (Alpha) variant. The developed assay, tested and validated in wastewater samples across 19 communities in the United States, is able to reliably detect and quantify low levels of the B.1.1.7 (Alpha) variant with low cross-reactivity, and at variant proportions down to 1 percent in a background of mixed SARS-CoV-2 viruses.

Targeting spike protein mutations that are highly predictive of the B.1.1.7 (Alpha) variant, the method can be implemented using commercially available RT-qPCR protocols. Unlike commercially available products that use proprietary primers and probes for wastewater surveillance, the paper details the open-source method and its development that can be freely used by other organizations and research institutes for their work on wastewater surveillance of SARS-CoV-2 and its variants.

The breakthrough by the research team in Singapore is currently used by Biobot Analytics, an MIT startup and global leader in wastewater epidemiology headquartered in Cambridge, Massachusetts, serving states and localities throughout the United States. Using the method, Biobot Analytics is able to accept and analyze wastewater samples for the B.1.1.7 (Alpha) variant and plans to add additional variants to its analysis as methods are developed. For example, the SMART AMR team is currently developing specific assays that will be able to detect and quantify the B.1.617.2 (Delta) variant, which has recently been identified as a variant of concern by the World Health Organization.

“Using the team’s innovative method, we have been able to monitor the B.1.1.7 (Alpha) variant in local populations in the U.S. — empowering leaders with information about Covid-19 trends in their communities and allowing them to make considered recommendations and changes to control measures,” says Mariana Matus PhD ’18, Biobot Analytics CEO and co-founder.

“This method can be rapidly adapted to detect new variants of concern beyond B.1.1.7,” adds MIT's Alm. “Our partnership with Biobot Analytics has translated our research into real-world impact beyond the shores of Singapore and aid in the detection of Covid-19 and its variants, serving as an early warning system and guidance for policymakers as they trace infection clusters and consider suitable public health measures.”

The research is carried out by SMART and supported by the National Research Foundation (NRF) Singapore under its Campus for Research Excellence And Technological Enterprise (CREATE) program.

SMART was established by MIT in partnership with the National Research Foundation of Singapore (NRF) in 2007. SMART is the first entity in CREATE developed by NRF. SMART serves as an intellectual and innovation hub for research interactions between MIT and Singapore, undertaking cutting-edge research projects in areas of interest to both Singapore and MIT. SMART currently comprises an Innovation Center and five IRGs: AMR, Critical Analytics for Manufacturing Personalized-Medicine, Disruptive and Sustainable Technologies for Agricultural Precision, Future Urban Mobility, and Low Energy Electronic Systems.

The AMR interdisciplinary research group is a translational research and entrepreneurship program that tackles the growing threat of antimicrobial resistance. By leveraging talent and convergent technologies across Singapore and MIT, AMR aims to develop multiple innovative and disruptive approaches to identify, respond to, and treat drug-resistant microbial infections. Through strong scientific and clinical collaborations, its goal is to provide transformative, holistic solutions for Singapore and the world.



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A new approach to preventing human-induced earthquakes

When humans pump large volumes of fluid into the ground, they can set off potentially damaging earthquakes, depending on the underlying geology. This has been the case in certain oil- and gas-producing regions, where wastewater, often mixed with oil, is disposed of by injecting it back into the ground — a process that has triggered sizable seismic events in recent years.

Now MIT researchers, working with an interdisciplinary team of scientists from industry and academia, have developed a method to manage such human-induced seismicity, and have demonstrated that the technique successfully reduced the number of earthquakes occurring in an active oil field.

Their results, appearing today in Nature, could help mitigate earthquakes caused by the oil and gas industry, not just from the injection of wastewater produced with oil, but also that produced from hydraulic fracturing, or “fracking.” The team’s approach could also help prevent quakes from other human activities, such as the filling of water reservoirs and aquifers, and the sequestration of carbon dioxide in deep geologic formations.

“Triggered seismicity is a problem that goes way beyond producing oil,” says study lead author Bradford Hager, the Cecil and Ida Green Professor of Earth Sciences in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “This is a huge problem for society that will have to be confronted if we are to safely inject carbon dioxide into the subsurface. We demonstrated the kind of study that will be necessary for doing this.”

The study’s co-authors include Ruben Juanes, professor of civil and environmental engineering at MIT, and collaborators from the University of California at Riverside, the University of Texas at Austin, Harvard University, and Eni, a multinational oil and gas company based in Italy.

Safe injections

Both natural and human-induced earthquakes occur along geologic faults, or fractures between two blocks of rock in the Earth’s crust. In stable periods, the rocks on either side of a fault are held in place by the pressures generated by surrounding rocks. But when a large volume of fluid is suddenly injected at high rates, it can upset a fault’s fluid stress balance. In some cases, this sudden injection can lubricate a fault and cause rocks on either side to slip and trigger an earthquake.

The most common source of such fluid injections is from the oil and gas industry’s disposal of wastewater that is brought up along with oil. Field operators dispose of this water through injection wells that continuously pump the water back into the ground at high pressures.

“There’s a lot of water produced with the oil, and that water is injected into the ground, which has caused a large number of quakes,” Hager notes. “So, for a while, oil-producing regions in Oklahoma had more magnitude 3 quakes than California, because of all this wastewater that was being injected.”

In recent years, a similar problem arose in southern Italy, where injection wells on oil fields operated by Eni triggered microseisms in an area where large naturally occurring earthquakes had previously occurred. The company, looking for ways to address the problem, sought consulation from Hager and Juanes, both leading experts in seismicity and subsurface flows.

“This was an opportunity for us to get access to high-quality seismic data about the subsurface, and learn how to do these injections safely,” Juanes says.

Seismic blueprint

The team made use of detailed information, accumulated by the oil company over years of operation in the Val D’Agri oil field, a region of southern Italy that lies in a tectonically active basin. The data included information about the region’s earthquake record, dating back to the 1600s, as well as the structure of rocks and faults, and the state of the subsurface corresponding to the various injection rates of each well.

earthquakeearthquake

The researchers integrated these data into a coupled subsurface flow and geomechanical model, which predicts how the stresses and strains of underground structures evolve as the volume of pore fluid, such as from the injection of water, changes. They connected this model to an earthquake mechanics model in order to translate the changes in underground stress and fluid pressure into a likelihood of triggering earthquakes. They then quantified the rate of earthquakes associated with various rates of water injection, and identified scenarios that were unlikely to trigger large quakes.

When they ran the models using data from 1993 through 2016, the predictions of seismic activity matched with the earthquake record during this period, validating their approach. They then ran the models forward in time, through the year 2025, to predict the region’s seismic response to three different injection rates: 2,000, 2,500, and 3,000 cubic meters per day. The simulations showed that large earthquakes could be avoided if operators kept injection rates at 2,000 cubic meters per day — a flow rate comparable to a small public fire hydrant.

Eni field operators implemented the team’s recommended rate at the oil field’s single water injection well over a 30-month period between January 2017 and June 2019. In this time, the team observed only a few tiny seismic events, which coincided with brief periods when operators went above the recommended injection rate.

“The seismicity in the region has been very low in these two-and-a-half years, with around four quakes of 0.5 magnitude, as opposed to hundreds of quakes, of up to 3 magnitude, that were happening between 2006 and 2016,” Hager says. 

The results demonstrate that operators can successfully manage earthquakes by adjusting injection rates, based on the underlying geology. Juanes says the team’s modeling approach may help to prevent earthquakes related to other processes, such as the building of water reservoirs and the sequestration of carbon dioxide — as long as there is detailed information about a region’s subsurface.

“A lot of effort needs to go into understanding the geologic setting,” says Juanes, who notes that, if carbon sequestration were carried out on depleted oil fields, “such reservoirs could have this type of history, seismic information, and geologic interpretation that you could use to build similar models for carbon sequestration. We show it’s at least possible to manage seismicity in an operational setting. And we offer a blueprint for how to do it.”

This research was supported, in part, by Eni.



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martes, 27 de julio de 2021

Life in space: Preparing for an increasingly tangible reality

As a not-so-distant future that includes space tourism and people living off-planet approaches, the MIT Media Lab Space Exploration Initiative is designing and researching the activities humans will pursue in new, weightless environments. 

Since 2017, the Space Exploration Initiative (SEI) has orchestrated regular parabolic flights through the ZERO-G Research Program to test experiments that rely on microgravity. This May, the SEI supported researchers from the Media Lab; MIT's departments of Aeronautics and Astronautics (AeroAstro), Earth, Atmospheric and Planetary Sciences (EAPS), and Mechanical Engineering; MIT Kavli Institute; the MIT Program in Art, Culture, and Technology; the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL); the John A. Paulson School of Engineering and Applied Sciences (SEAS) at Harvard University; the Center for Collaborative Arts and Media at Yale University; the multi-affiliated Szostak Laboratory, and the Harvard-MIT Program in Health Sciences and Technology to fly 22 different projects exploring research as diverse as fermentation, reconfigurable space structures, and the search for life in space. 

Most of these projects resulted from the 2019 or 2020 iterations of MAS.838 / 16.88 (Prototyping Our Space Future) taught by Ariel Ekblaw, SEI founder and director, who began teaching the class in 2018. (Due to the Covid-19 pandemic, the 2020 flight was postponed, leading to two cohorts being flown this year.)

“The course is intentionally titled ‘Prototyping our Sci-Fi Space Future,’” she says, “because this flight opportunity that SEI wrangles, for labs across MIT, is meant to incubate and curate the future artifacts for life in space and robotic exploration — bringing the Media Lab's uniqueness, magic, and creativity into the process.” 

The class prepares researchers for the realities of parabolic flights, which involves conducting experiments in short, 20-second bursts of zero gravity. As the course continues to offer hands-on research and logistical preparation, and as more of these flights are executed, the projects themselves are demonstrating increasing ambition and maturity. 

“Some students are repeat flyers who have matured their experiments, and [other experiments] come from researchers across the MIT campus from a record number of MIT departments, labs, and centers, and some included alumni and other external collaborators,” says Maria T. Zuber, MIT’s vice president for research and SEI faculty advisor. “In short, there was stiff competition to be selected, and some of the experiments are sufficiently far along that they’ll soon be suitable for spaceflight.” 

Dream big, design bold 

Both the 2020 and 2021 flight cohorts included daring new experiments that speak to SEI’s unique focus on research across disciplines. Some look to capitalize on the advantages of microgravity, while others seek to help find ways of living and working without the force that governs every moment of life on Earth. 

Che-Wei Wang, Sands Fish, and Mehak Sarang from SEI collaborated on Zenolith, a free-flying pointing device to orient space travelers in the universe — or, as the research team puts it, a 3D space compass. “We were able to perform some maneuvers in zero gravity and confirm that our control system was functioning quite well, the first step towards having the device point to any spot in the solar system,” says Sarang. “We'll still have to tweak the design as we work towards our ultimate goal of sending the device to the International Space Station!” 

Then there’s the Gravity Loading Countermeasure Skinsuit project by Rachel Bellisle, a doctoral student in the Harvard-MIT Program in Health Sciences and Technology and a Draper Fellow. The Skinsuit is designed to replicate the effects of Earth gravity for use in exercise on future missions to the moon or to Mars, and to further attenuate microgravity-induced physiological effects in current ISS mission scenarios. The suit has a 10-plus-year history of development at MIT and internationally, with prior parabolic flight experiments. Skinsuit originated in the lab of Dava Newman, who now serves as Media Lab director.

“Designing, flying, and testing an actual prototype is the best way that I know of to prepare our suit designs for actual long-term spaceflight missions,” says Newman. “And flying in microgravity and partial gravity on the ZERO-G plane is a blast!” 

Alongside the Skinsuit are two more projects flown this spring that involve wearables and suit prototypes: the Peristaltic Suit developed by Media Lab researcher Irmandy Wicaksono and the Bio-Digital Wearables or Space Health Enhancement project by Media Lab researcher Pat Pataranutaporn. 

“Wearables have the potential to play a critical role in monitoring, supporting, and sustaining human life in space, lessening the need for human medical expert intervention,” Pataranutaporn says. “Also, having this microgravity experience after our SpaceCHI workshop ... gave me so many ideas for thinking about other on-body systems that can augment humans in space — that I don’t think I would get from just reading a research paper.” 

AgriFuge, from Somayajulu Dhulipala and Manwei Chan (graduate students in MIT's departments of Mechanical Engineering and AeroAstro, respectively), offers future astronauts a rotating plant habitat that provides simulated gravity as well as a controllable irrigation system. AgriFuge anticipates a future of long-duration missions where the crew will grow their own plants — to replenish oxygen and food, as well as for the psychological benefits of caring for plants. Two more cooking-related projects that flew this spring include H0TP0T, by Larissa Zhou from Harvard SEAS, and Gravity Proof, by Maggie Coblentz of the SEI — each of which help demonstrate a growing portfolio of practical “life in space” research being tested on these flights. 

The human touch 

In addition to the increasingly ambitious and sophisticated individual projects, an emerging theme in SEI’s microgravity endeavor is a focus on approaches to different aspects of life and culture in space — not only in relation to cooking, but also architecture, music, and art. 

Sanjana Sharma of the SEI flew her Fluid Expressions project this spring, which centers around the design of a memory capsule that functions as both a traveler’s painting kit for space and an embodied, material reminder of home. During the flight, she was able to produce three abstract watercolor paintings. “The most important part of this experience for me,” she says, “was the ability to develop a sense of what zero gravity actually feels like, as well as how the motions associated with painting differ during weightlessness.” 

Ekblaw has been mentoring two new architectural projects as part of the SEI’s portfolio, building on her own TESSERAE work for in-space self-assembly: Self Assembling Space Frames by SEI’s Che-Wei Wang and Reconfigurable space structures by Martin Nisser of MIT CSAIL. Wang envisions his project as a way to build private spaces in zero-gravity environments. “You could think of it like a pop-up tent for space,” he says. “The concept can potentially scale to much larger structures that self-assemble in space, outside space stations.” 

Onward and upward

Two projects that explore different notions of the search for life in space include Ø-scillation, a collaboration between several scientists at the MIT Kavli Institute, Media Lab, EAPS, and Harvard; and the Electronic Life-detection Instrument (ELI) by Chris Carr, former MIT EAPS researcher and current Georgia Tech faculty member, and Daniel Duzdevich, a postdoc at the Szostak Laboratory. 

The ELI project is a continuation of work within Zuber’s lab, and has been flown on previous flights. “Broadly, our goals are to build a low-mass life-detection instrument capable of detecting life as we know it — or as we don't know it,” says Carr. During the 2021 flight, the researchers tested upgraded hardware that permits automatic real-time sub-nanometer gap control to improve the measurement fidelity of the system — with generally successful results. 

Microgravity Hybrid Extrusion, led by SEI’s mission integrator, Sean Auffinger, alongside Ekblaw, Nisser, Wang, and MIT Undergraduate Research Opportunities Program student Aiden Padilla, was tested on both flights this spring and works toward building in situ, large-scale space structures — it’s also one of the selected projects being flown on an ISS mission in December 2021. The SEI is also planning a prospective "Astronaut Interaction" mission on the ISS in 2022, where artifacts like Zenolith will have the chance to be manipulated by astronauts directly. 

This is a momentous fifth anniversary year for SEI. As these annual flights continue, and the experiments aboard them keep growing more advanced, researchers are setting their sights higher — toward designing and preparing for the future of interplanetary civilization. 



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Keylime security software is deployed to IBM cloud

Keylime, a cloud security software architecture, is being adopted into IBM's cloud fleet. Originally developed at MIT Lincoln Laboratory to allow system administrators to ensure the security of their cloud environment, Keylime is now a Cloud Native Computing Foundation sandbox technology with more than 30 open-source developers contributing to it from around the world. The software will enable IBM to remotely attest to the security of its thousands of cloud servers.

"It is exciting to see the hard work of the growing Keylime community coming to fruition," says Charles Munson, a researcher in the Secure Resilient Systems and Technology Group at Lincoln Laboratory who created Keylime with Nabil Schear, now at Netflix. "Adding integrated support for Keylime into IBM's cloud fleet is an important step towards enabling cloud customers to have a zero-trust capability of 'never trust, always verify.'"

In a blog post announcing IBM's integration of Keylime, George Almasi of IBM Research said, "IBM has planned a rapid rollout of Keylime-based attestation to the entirety of its cloud fleet in order to meet requirements for a strong security posture from its financial services and other enterprise customers. This will leverage work done on expanding the scalability and resilience of Keylime to manage large numbers of nodes, allowing Keylime-based attestation to be operationalized at cloud data center scale."

Keylime is a key bootstrapping and integrity management software architecture. It was first developed to enable organizations to check for themselves that the servers storing and processing their data are as secure as cloud service providers claim they are. Today, many organizations use a form of cloud computing called infrastructure-as-a-service, whereby they rent computing resources from a cloud provider who is responsible for the security of the underlying systems.

To enable remote cloud-security checks, Keylime leverages a piece of hardware called a trusted platform module, or TPM, an industry-standard and widely used hardware security chip. A TPM generates a hash, a short string of numbers representing a much larger amount of data. If data are tampered with even slightly, the hash will change significantly, a security alarm that Keylime can detect and react to in under a second.

Before Keylime, TPMs were incompatible with cloud technology, slowing down systems and forcing engineers to change software to accommodate the module. Keylime gets around these problems by serving as a piece of intermediary software that allows users to leverage the security benefits of the TPM without having to make all of their software compatible with it.

In 2019, Keylime was transitioned into the CNCF as a sandbox technology with the help of RedHat, one of the world's leading open-source software companies. This transition better incorporated Keylime into the Linux open-source ecosystem, making it simpler for users to adopt. In 2020, the Lincoln Laboratory team that developed Keylime was awarded an R&D 100 Award, recognizing the software among the year's 100 most innovative new technologies available for sale or license.



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What will happen to sediment plumes associated with deep-sea mining?

In certain parts of the deep ocean, scattered across the seafloor, lie baseball-sized rocks layered with minerals accumulated over millions of years. A region of the central Pacific, called the Clarion Clipperton Fracture Zone (CCFZ), is estimated to contain vast reserves of these rocks, known as “polymetallic nodules,” that are rich in nickel and cobalt  — minerals that are commonly mined on land for the production of lithium-ion batteries in electric vehicles, laptops, and mobile phones.

As demand for these batteries rises, efforts are moving forward to mine the ocean for these mineral-rich nodules. Such deep-sea-mining schemes propose sending down tractor-sized vehicles to vacuum up nodules and send them to the surface, where a ship would clean them and discharge any unwanted sediment back into the ocean. But the impacts of deep-sea mining — such as the effect of discharged sediment on marine ecosystems and how these impacts compare to traditional land-based mining — are currently unknown.

Now oceanographers at MIT, the Scripps Institution of Oceanography, and elsewhere have carried out an experiment at sea for the first time to study the turbulent sediment plume that mining vessels would potentially release back into the ocean. Based on their observations, they developed a model that makes realistic predictions of how a sediment plume generated by mining operations would be transported through the ocean.

The model predicts the size, concentration, and evolution of sediment plumes under various marine and mining conditions. These predictions, the researchers say, can now be used by biologists and environmental regulators to gauge whether and to what extent such plumes would impact surrounding sea life.

“There is a lot of speculation about [deep-sea-mining’s] environmental impact,” says Thomas Peacock, professor of mechanical engineering at MIT. “Our study is the first of its kind on these midwater plumes, and can be a major contributor to international discussion and the development of regulations over the next two years.”

The team’s study appears today in Nature Communications: Earth and Environment.

Peacock’s co-authors at MIT include lead author Carlos Muñoz-Royo, Raphael Ouillon, Chinmay Kulkarni, Patrick Haley, Chris Mirabito, Rohit Supekar, Andrew Rzeznik, Eric Adams, Cindy Wang, and Pierre Lermusiaux, along with collaborators at Scripps, the U.S. Geological Survey, and researchers in Belgium and South Korea.

Out to sea

Current deep-sea-mining proposals are expected to generate two types of sediment plumes in the ocean: “collector plumes” that vehicles generate on the seafloor as they drive around collecting nodules 4,500 meters below the surface; and possibly “midwater plumes” that are discharged through pipes that descend 1,000 meters or more into the ocean’s aphotic zone, where sunlight rarely penetrates.

In their new study, Peacock and his colleagues focused on the midwater plume and how the sediment would disperse once discharged from a pipe.

“The science of the plume dynamics for this scenario is well-founded, and our goal was to clearly establish the dynamic regime for such plumes to properly inform discussions,” says Peacock, who is the director of MIT’s Environmental Dynamics Laboratory.

To pin down these dynamics, the team went out to sea. In 2018, the researchers boarded the research vessel Sally Ride and set sail 50 kilometers off the coast of Southern California. They brought with them equipment designed to discharge sediment 60 meters below the ocean’s surface.  

“Using foundational scientific principles from fluid dynamics, we designed the system so that it fully reproduced a commercial-scale plume, without having to go down to 1,000 meters or sail out several days to the middle of the CCFZ,” Peacock says.

Over one week the team ran a total of six plume experiments, using novel sensors systems such as a Phased Array Doppler Sonar (PADS) and epsilometer developed by Scripps scientists to monitor where the plumes traveled and how they evolved in shape and concentration. The collected data revealed that the sediment, when initially pumped out of a pipe, was a highly turbulent cloud of suspended particles that mixed rapidly with the surrounding ocean water.

“There was speculation this sediment would form large aggregates in the plume that would settle relatively quickly to the deep ocean,” Peacock says. “But we found the discharge is so turbulent that it breaks the sediment up into its finest constituent pieces, and thereafter it becomes dilute so quickly that the sediment then doesn’t have a chance to stick together.”

Dilution

The team had previously developed a model to predict the dynamics of a plume that would be discharged into the ocean. When they fed the experiment’s initial conditions into the model, it produced the same behavior that the team observed at sea, proving the model could accurately predict plume dynamics within the vicinity of the discharge.

The researchers used these results to provide the correct input for simulations of ocean dynamics to see how far currents would carry the initially released plume.

“In a commercial operation, the ship is always discharging new sediment. But at the same time the background turbulence of the ocean is always mixing things. So you reach a balance. There’s a natural dilution process that occurs in the ocean that sets the scale of these plumes,” Peacock says. “What is key to determining the extent of the plumes is the strength of the ocean turbulence, the amount of sediment that gets discharged, and the environmental threshold level at which there is impact.”

Based on their findings, the researchers have developed formulae to calculate the scale of a plume depending on a given environmental threshold. For instance, if regulators determine that a certain concentration of sediments could be detrimental to surrounding sea life, the formula can be used to calculate how far a plume above that concentration would extend, and what volume of ocean water would be impacted over the course of a 20-year nodule mining operation.

“At the heart of the environmental question surrounding deep-sea mining is the extent of sediment plumes,” Peacock says. “It’s a multiscale problem, from micron-scale sediments, to turbulent flows, to ocean currents over thousands of kilometers. It’s a big jigsaw puzzle, and we are uniquely equipped to work on that problem and provide answers founded in science and data.”

The team is now working on collector plumes, having recently returned from several weeks at sea to perform the first environmental monitoring of a nodule collector vehicle in the deep ocean in over 40 years.

This research was supported in part by the MIT Environmental Solutions Initiative, the UC Ship Time Program, the MIT Policy Lab, the 11th Hour Project of the Schmidt Family Foundation, the Benioff Ocean Initiative, and Fundación Bancaria “la Caixa.”



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lunes, 26 de julio de 2021

Investigating materials for safe, secure nuclear power

Michael Short came to MIT in the fall of 2001 as an 18-year-old first-year who grew up in Boston’s North Shore. He immediately felt at home, so much so that he’s never really left. It’s not that Short has no interest in exploring the world beyond the confines of the Institute, as he is an energetic and venturesome fellow. It’s just that almost everything he hopes to achieve in his scientific career can, in his opinion, be best pursued at this university.

Last year — after collecting four MIT degrees and joining the faculty of the Department of Nuclear Science and Engineering (NSE) in 2013 — he was promoted to the status of tenured associate professor.

Short’s enthusiasm for MIT began early in high school when he attended weekend programs that were mainly taught by undergraduates. “It was a program filled with my kind of people,” he recalls. “My high school was very good, but this was at a different level — at the level I was seeking and hoping to achieve. I felt more at home here than I did in my hometown, and the Saturdays at MIT were the highlight of my week.” He loved his four-year experience as an MIT undergraduate, including the research he carried out in the Uhlig Corrosion Laboratory, and he wasn’t ready for it to end.

After graduating in 2005 with two BS degrees (one in NSE and another in materials science and engineering), he took on some computer programming jobs and worked half time in the Uhlig lab under the supervision of Ronald Ballinger, a professor in both NSE and the Department of Materials Science and Engineering. Short soon realized that computer programming was not for him, and he started graduate studies with Ballinger as his advisor, earning a master’s and a PhD in nuclear science and engineering in 2010.

Even as an undergraduate, Short was convinced that nuclear power was essential to our nation’s (and the world’s) energy future, especially in light of the urgent need to move toward carbon-free sources of power. During his first year, he was told by Ballinger that the main challenge confronting nuclear power was to find materials, and metals in particular, that could last long enough in the face of radiation and the chemically destructive effects of corrosion.

Those words, persuasively stated, led him to his double major.  “Materials and radiation damage have been at the core of my research ever since,” Short says. “Remarkably, the stuff I started studying in my first year of college is what I do today, though I’ve extended this work in many directions.”

Corrosion has proven to be an unexpectedly rich subject. “The traditional view is to expose metals to various things and see what happens — ‘cook and look,’ as it’s called,” he says. “A lot of folks view it that way, but it’s actually much more complex. In fact, some members of our own faculty don’t want to touch corrosion because it’s too complicated, too dirty. But that’s what I like about it.”

In a 2020 paper published in Nature Communications, Short, his student Weiyue Zhou, and other colleagues made a surprising discovery. “Most people think radiation is bad and makes everything worse, but that’s not always the case,” Short maintains. His team found a specific set of conditions under which a metal (a nickel-chromium alloy) performs better when it is irradiated while undergoing corrosion in a molten salt mixture. Their finding is relevant, he adds, “because these are the conditions under which people are hoping to run the next generation of nuclear reactors.” Leading candidates for alternatives to today’s water-cooled reactors are molten salt and liquid metal (specifically liquid lead and sodium) cooled reactors. To this end, Short and his colleagues are currently carrying out similar experiments involving the irradiation of metal alloys immersed in liquid lead.

Meanwhile, Short has pursued another multiyear project, trying to devise a new standard to serve as “a measurable unit of radiation damage.” In fact, these were the very words he wrote on his research statement when applying for his first faculty position at MIT, although he admits that he didn’t know then how to realize that goal. But the effort is finally paying off, as Short and his collaborators are about to submit their first big paper on the topic. He’s found that you can’t reduce radiation damage to a single number, which is what people have tried to do in the past, because that’s too simple. Instead, their new standard relates to the density of defects — the number of radiation-induced defects (or unintentional changes to the lattice structure) per unit volume for a given material.

“Our approach is based on a theory that everyone agrees on — that defects have energy,” Short explains. However, many people told him and his team that the amount of energy stored within those defects would be too small to measure. But that just spurred them to try harder, making measurements at the microjoule level, at the very limits of detection.

Short is convinced that their new standard will become “universally useful, but it will take years of testing on many, many materials followed by more years of convincing people using the classic method: Repeat, repeat, repeat, making sure that each time you get the same result. It’s the unglamorous side of science, but that’s the side that really matters.”

The approach has already led Short, in collaboration with NSE proliferation expert Scott Kemp, into the field of nuclear security. Equipped with new insights into the signatures left behind by radiation damage, students co-supervised by Kemp and Short have devised methods for determining how much fissionable material has passed through a uranium enrichment facility, for example, by scrutinizing the materials exposed to these radioactive substances. “I never thought my preliminary work on corrosion experiments as an undergraduate would lead to this,” Short says.

He has also turned his attention to “microreactors” — nuclear reactors with power ratings as small as a single megawatt, as compared to the 1,000-megawatt behemoths of today. Flexibility in the size of future power plants is essential to the economic viability of nuclear power, he insists, “because nobody wants to pay $10 billion for a reactor now, and I don’t blame them.”

But the proposed microreactors, he says, “pose new material challenges that I want to solve. It comes down to cramming more material into a smaller volume, and we don’t have a lot of knowledge about how materials perform at such high densities.” Short is currently conducting experiments with the Idaho National Laboratory, irradiating possible microreactor materials to see how they change using a laser technique, transient grating spectroscopy (TGS), which his MIT group has had a big hand in advancing.

It’s been an exhilarating 20 years at MIT for Short, and he has even more ambitious goals for the next 20 years. “I’d like to be one of those who came up with a way to verify the Iran nuclear deal and thereby helped clamp down on nuclear proliferation worldwide,” he says. “I’d like to choose the materials for our first power-generating nuclear fusion reactors. And I’d like to have influenced perhaps 50 to 100 former students who chose to stay in science because they truly enjoy it.

“I see my job as creating scientists, not science,” he says, “though science is, of course, a convenient byproduct.”



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Brain’s “memory center” is needed to recognize image sequences, but not single sights

A new MIT study of how a mammalian brain remembers what it sees shows that while individual images are stored in the visual cortex, the ability to recognize a sequence of sights critically depends on guidance from the hippocampus, a deeper structure strongly associated with memory but shrouded in mystery about exactly how.

By suggesting that the hippocampus isn’t needed for basic storage of images so much as identifying the chronological relationship they may have, the new research, published in Current Biology, can bring neuroscientists closer to understanding how the brain coordinates long-term visual memory across key regions.

“This offers the opportunity to actually understand, in a very concrete way, how the hippocampus contributes to memory storage in the cortex,” says senior author Mark Bear, the Picower Professor of Neuroscience in the Picower Institute for Learning and Memory and the Department of Brain and Cognitive Sciences.

Essentially, the hippocampus acts to influence how images are stored in the cortex if they have a sequential relationship, says lead author Peter Finnie, a former postdoc in Bear’s lab.

“The exciting part of this is that the visual cortex seems to be involved in encoding both very simple visual stimuli and also temporal sequences of them, and yet the hippocampus is selectively involved in how that sequence is stored,” Finnie says.

To have hippocampus and have not

To make their findings, the researchers, including former postdoc Rob Komorowski, trained mice with two forms of visual recognition memory discovered in Bear’s lab. The first form of memory, called stimulus selective response plasticity (SRP) involves learning to recognize a nonrewarding, nonthreatening single visual stimulus after it has been presented over and over. As learning occurs, visual cortex neurons produce an increasingly strong electrical response and the mouse ceases paying attention to the once-novel, but now decidedly uninteresting, image. The second form of memory, visual sequence plasticity, involves learning to recognize and predict a sequence of images. Here, too, the once-novel but now-familiar and innocuous sequence comes to evoke an elevated electrical response, and it is much greater than what is observed if the same stimuli are presented in reverse order or at a different speed.

In prior studies Bear’s lab has shown that the images in each form of memory are stored in the visual cortex, and are even specific to which eye beheld them, if only one did.

But the researchers were curious about whether and how the hippocampus might contribute to these forms of memory and cortical plasticity. After all, like some other forms of memory that depend on the hippocampus, SRP only takes hold after a period of “consolidation,” for instance overnight during sleep. To test whether there is a role for the hippocampus, they chemically removed large portions of the structure in a group of mice and looked for differences between groups in the telltale electrical response each kind of recognition memory should evoke.

Mice with or without a hippocampus performed equally well in learning SRP (measured not only electrophysiologically but also behaviorally), suggesting that the hippocampus was not needed for that form of memory. It appears to arise, and even consolidate, entirely within the visual cortex.

Visual sequence plasticity, however, did not occur without an intact hippocampus, the researchers found. Mice without the structure showed no elevated electrical response to the sequences when tested, no ability to recognize them in reverse or when delayed, and no inclination to “fill in the blank” when one was missing. It was as if the visual sequence — and even each image in the sequence — was not familiar.

“Together these findings are consistent with a specific role for the hippocampus in predictive response generation during exposure to familiar temporal patterns of visual stimulation,” the authors wrote.

New finding from a classic approach

The experiments follow in a long tradition of attempting to understand the hippocampus by assessing what happens when it’s damaged. For decades, neuroscientists at MIT and elsewhere were able to learn from a man known as “H.M.,” who had undergone hippocampal removal to relieve epileptic seizures. His memory of his past before the surgery remained intact, but he exhibited an inability to form “declarative” memories of new experiences, such as meeting someone or performing an activity. Over time, however, scientists realized that he could be trained to learn motor tasks better, even though he wouldn’t remember the training itself. The experiments helped to reveal that for many different forms of memory there is a “division of labor” among regions of the brain that may or may not include the hippocampus.

The new study, Bear and Finnie say, produces a clear distinction through the division of labor in visual memory between simple recognition of images and the more complex task of recognizing of sequence structure.

“It’s a nice dividing line,” Bear says. “It’s the same region of the brain, the same method of an animal looking at images on a screen. All we are changing is the temporal structure of the stimulus.”

Alzheimer’s assessment?

Previous research in the lab showed that SRP and visual sequence plasticity arise via different molecular mechanisms. SRP can be disrupted by blocking receptors for the neurotransmitter glutamate on involved neurons while sequence plasticity depends on receptors for acetylcholine.

The next question Bear wants to address, therefore, is whether an acetylcholine-producing circuit links the hippocampus to the visual cortex to accomplish sequence learning. Neurons that release acetylcholine in the cortex happen to be among the earliest disrupted in Alzheimer’s disease.

If the circuit for sequence learning indeed runs through those neurons, Bear speculates, then assessing people for differences in SRP and sequence learning could become a way to diagnose early onset of dementia progression.

The National Eye Institute of the National Institutes of Health and the JPB Foundation funded the research.



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