Popular new major blends technical skills and human-centered applications

Annie Snyder wasn’t sure what she wanted to major in when she arrived on campus. She drifted toward MIT’s most popular major, electrical engineering and computer science (EECS), also known as Course 6, but it didn’t feel like quite the right fit. She was interested in computer science but more passionate about understanding how technology affects people’s everyday lives.

Snyder, now a junior, found a compelling mix of technical skills and human-centered applications in the major 6-14: Computer Science, Economics, and Data Science, which was jointly launched by the computer science and economics departments in 2017.

The major 6-14 is a unique blend of computer science, data science, and economics. Students learn computing fundamentals, like programming and algorithms, and receive a multifaceted view of data science, from machine learning to econometrics. The major also covers economics concepts like game theory, incentives, and multiagent systems.

“The economics side of things fascinated me. It seemed like this interesting way to take these technical concepts that are really abstract, which I was familiar with through my math background, and apply them to people, society, and modeling human behavior,” Snyder says. “At the same time, computing is a tool that is going to permeate every field, so having that computing experience is a way to up your game, in a sense.”

Since its inception, Course 6-14 has attracted students with a diverse set of interests. About 40 students chose the major in 2017 and it has since grown to include 135 students, more than half of whom are women. The first cohort of computer science and economics “bilinguals” graduated last year. Students have followed a wide range of paths, including joining tech giants like Google and Microsoft, starting careers at finance and management consulting companies, working in logistics or data analytics, pursuing academic research, and more.

Economics and computing join forces

Computer science and economics have always had some overlap, but as more market exchanges take place in online systems, the fields have become inseparable. The decision to create the blended major 6-14 grew out of developing collaborations between faculty in both departments, as well as strong student interest in the increasingly intertwined disciplines, says Asu Ozdaglar, head of the Department of Electrical Engineering and Computer Science and deputy dean of academics of the Schwarzman College of Computing, who helped oversee the launch of the new major.

Faculty members wanted to blend the fields in a way that would inspire and empower students, she says. Course 6-14 majors learn a variety of mathematical skills, but they also acquire hands-on experience in empirical analysis of data to uncover and solve real-world problems.

“The combination of topics and skills that 6-14 offers is not just useful for scholars intending to specialize at this exciting interface. The job market for our undergraduates has long valued exactly this combination of skills, as jobs in computer science and data science increasingly value knowledge of economic analysis, while job opportunities in economics, management consulting, and finance now often demand not just mathematical maturity but strong computational, algorithmic, and statistical expertise,” says Ozdaglar.

From the classroom to the real world

Computer science and data science provide tools for problem solving, and economics applies those tools to domains where there is rapidly growing intellectual, scholarly, and commercial interest, says David Autor, the Ford Professor of Economics, who helped launch Course 6-14.

He expects demand for graduates with skills in both disciplines will continue increasing, especially as more economic activity moves online. Companies large and small will need employees who can design platforms, think about incentives, and interpret large amounts of behavioral data.

Autor also hopes that the major 6-14 will raise awareness of economics at MIT and showcase that the field is a formal science with a widely useful toolset.

“Economics teaches people to think about social science problems analytically, in a very compelling and constructive way. Some of those problems are in ecommerce and data analysis, but some of those problems are in economic development, or social insurance programs, or climate science. The value of economics is that it provides a toolkit for applying the same kind of analytical thinking someone would to an engineering or computer science problem to these problems that greatly shape our world,” he says. 

Preparing computing ‘bilinguals’

Senior Ali Sinan Kaya leveraged the skills he’s developed in Course 6-14 to land internships and research opportunities that will give him a leg up in his future career. He recently completed a UROP (Undergraduate Research Opportunities Program) at the MIT Sloan School of Management that involved testing an optimization algorithm for an online retailer.

The company offers services like assembly and insurance to customers who purchase furniture online. Kaya and his collaborators found that the way those services are displayed on the website has a huge impact on purchasing behavior.

“[Course] 6-14 gave me a good foundation that I was able to use when interviewing for these positions, to secure these internships,” he says. “Economics, computer science, data science, and mathematics — at the intersection of these fields, you have a successful data scientist. I don’t consider myself a successful data scientist yet, but I think 6-14 has really given me a foundation to become a successful data scientist.”

Kaya plans to embark on a corporate career to better understand how the economy works. In the long term, he hopes to apply those lessons as a politician or policy expert in his native Turkey.

“I want to use all this knowledge and these experiences to hopefully bring about change within my community,” he says.

For Ozdaglar, it has been especially rewarding to see students like Kaya master both skill sets in an effort to do important work in the world.

“It has been amazing to help develop a program that educates students at this exciting intersection. We never viewed this as just putting curricula together across two departments. Rather, Course 6-14 combines the strengths of the two disciplines to offer unique classes and opportunities for our students. It provides such a strong foundation that students are able to address deep problems that require a mastery of both of these disciplines. It has been wonderful to see this new generation of computing ‘bilinguals’ who will be able to make great contributions,” she says.

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An energy-storage solution that flows like soft-serve ice cream

Batteries made from an electrically conductive mixture the consistency of molasses could help solve a critical piece of the decarbonization puzzle. An interdisciplinary team from MIT has found that an electrochemical technology called a semisolid flow battery can be a cost-competitive form of energy storage and backup for variable renewable energy (VRE) sources such as wind and solar. The group’s research is described in a paper published in Joule.

“The transition to clean energy requires energy storage systems of different durations for when the sun isn’t shining and the wind isn’t blowing,” says Emre Gençer, a research scientist with the MIT Energy Initiative (MITEI) and a member of the team. “Our work demonstrates that a semisolid flow battery could be a lifesaving as well as economical option when these VRE sources can’t generate power for a day or longer — in the case of natural disasters, for instance.”

The rechargeable zinc-manganese dioxide (Zn-MnO₂) battery the researchers created beat out other long-duration energy storage contenders. “We performed a comprehensive, bottom-up analysis to understand how the battery’s composition affects performance and cost, looking at all the trade-offs,” says Thaneer Malai Narayanan SM ’18, PhD ’21. “We showed that our system can be cheaper than others, and can be scaled up.”

Narayanan, who conducted this work at MIT as part of his doctorate in mechanical engineering, is the lead author of the paper. Additional authors include Gençer, Yunguang Zhu, a postdoc in the MIT Electrochemical Energy Lab; Gareth McKinley, the School of Engineering Professor of Teaching Innovation and professor of mechanical engineering at MIT; and Yang Shao-Horn, the JR East Professor of Engineering, a professor of mechanical engineering and of materials science and engineering, and a member of the Research Laboratory of Electronics (RLE), who directs the MIT Electrochemical Energy Lab.

Going with the flow

In 2016, Narayanan began his graduate studies, joining the Electrochemical Energy Lab, a hotbed of research and exploration of solutions to mitigate climate change, which is centered on innovative battery chemistry and decarbonizing fuels and chemicals. One exciting opportunity for the lab: developing low- and no-carbon backup energy systems suitable for grid-scale needs when VRE generation flags.                                                  

While the lab cast a wide net, investigating energy conversion and storage using solid oxide fuel cells, lithium-ion batteries, and metal-air batteries, among others, Narayanan took a particular interest in flow batteries. In these systems, two different chemical (electrolyte) solutions with either negative or positive ions are pumped from separate tanks, meeting across a membrane (called the stack). Here, the ion streams react, converting electrical energy to chemical energy — in effect, charging the battery. When there is demand for this stored energy, the solution gets pumped back to the stack to convert chemical energy into electrical energy again.

The duration of time that flow batteries can discharge, releasing the stored electricity, is determined by the volume of positively and negatively charged electrolyte solutions streaming through the stack. In theory, as long as these solutions keep flowing, reacting, and converting the chemical energy to electrical energy, the battery systems can provide electricity.

“For backup lasting more than a day, the architecture of flow batteries suggests they can be a cheap option,” says Narayanan. “You recharge the solution in the tanks from sun and wind power sources.” This renders the entire system carbon free.

But while the promise of flow battery technologies has beckoned for at least a decade, the uneven performance and expense of materials required for these battery systems has slowed their implementation. So, Narayanan set out on an ambitious journey: to design and build a flow battery that could back up VRE systems for a day or more, storing and discharging energy with the same or greater efficiency than backup rivals; and to determine, through rigorous cost analysis, whether such a system could prove economically viable as a long-duration energy option.

Multidisciplinary collaborators

To attack this multipronged challenge, Narayanan’s project brought together, in his words, “three giants, scientists all well-known in their fields”:  Shao-Horn, who specializes in chemical physics and electrochemical science, and design of materials; Gençer, who creates detailed economic models of emergent energy systems at MITEI; and McKinley, an expert in rheology, the physics of flow. These three also served as his thesis advisors.

“I was excited to work in such an interdisciplinary team, which offered a unique opportunity to create a novel battery architecture by designing charge transfer and ion transport within flowable semi-solid electrodes, and to guide battery engineering using techno-economics of such flowable batteries,” says Shao-Horn.

While other flow battery systems in contention, such as the vanadium redox flow battery, offer the storage capacity and energy density to back up megawatt and larger power systems, they depend on expensive chemical ingredients that make them bad bets for long duration purposes. Narayanan was on the hunt for less-pricey chemical components that also feature rich energy potential.

Through a series of bench experiments, the researchers came up with a novel electrode (electrical conductor) for the battery system: a mixture containing dispersed manganese dioxide (MnO₂) particles, shot through with an electrically conductive additive, carbon black. This compound reacts with a conductive zinc solution or zinc plate at the stack, enabling efficient electrochemical energy conversion. The fluid properties of this battery are far removed from the watery solutions used by other flow batteries.

“It’s a semisolid — a slurry,” says Narayanan. “Like thick, black paint, or perhaps a soft-serve ice cream,” suggests McKinley. The carbon black adds the pigment and the electric punch. To arrive at the optimal electrochemical mix, the researchers tweaked their formula many times.

“These systems have to be able to flow under reasonable pressures, but also have a weak yield stress so that the active MnO₂ particles don't sink to the bottom of the flow tanks when the system isn’t being used, as well as not separate into a battery/oily clear fluid phase and a dense paste of carbon particles and MnO₂,” says McKinley.

This series of experiments informed the technoeconomic analysis. By “connecting the dots between composition, performance, and cost,” says Narayanan, he and Gençer were able to make system-level cost and efficiency calculations for the Zn-MnO₂ battery.

“Assessing the cost and performance of early technologies is very difficult, and this was an example of how to develop a standard method to help researchers at MIT and elsewhere,” says Gençer. “One message here is that when you include the cost analysis at the development stage of your experimental work, you get an important early understanding of your project’s cost implications.”

In their final round of studies, Gençer and Narayanan compared the Zn-MnO₂ battery to a set of equivalent electrochemical battery and hydrogen backup systems, looking at the capital costs of running them at durations of eight, 24, and 72 hours. Their findings surprised them: For battery discharges longer than a day, their semisolid flow battery beat out lithium-ion batteries and vanadium redox flow batteries. This was true even when factoring in the heavy expense of pumping the MnO₂ slurry from tank to stack. “I was skeptical, and not expecting this battery would be competitive, but once I did the cost calculation, it was plausible,” says Gençer.

But carbon-free battery backup is a very Goldilocks-like business: Different situations require different-duration solutions, whether an anticipated overnight loss of solar power, or a longer-term, climate-based disruption in the grid. “Lithium-ion is great for backup of eight hours and under, but the materials are too expensive for longer periods,” says Gençer. “Hydrogen is super expensive for very short durations, and good for very long durations, and we will need all of them.” This means it makes sense to continue working on the Zn-MnO₂ system to see where it might fit in.

“The next step is to take our battery system and build it up,” says Narayanan, who is working now as a battery engineer. “Our research also points the way to other chemistries that could be developed under the semi-solid flow battery platform, so we could be seeing this kind of technology used for energy storage in our lifetimes.”

This research was supported by Eni S.p.A. through MITEI. Thaneer Malai Narayanan received an Eni-sponsored MIT Energy Fellowship during his work on the project.

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SMART researchers develop method for early detection of bacterial infection in crops

Researchers from the Disruptive and Sustainable Technologies for Agricultural Precision (DiSTAP) Interdisciplinary Research Group (IRG) of Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, and their local collaborators from Temasek Life Sciences Laboratory (TLL), have developed a rapid Raman spectroscopy-based method for detecting and quantifying early bacterial infection in crops. The Raman spectral biomarkers and diagnostic algorithm enable the noninvasive and early diagnosis of bacterial infections in crop plants, which can be critical for the progress of plant disease management and agricultural productivity.

Due to the increasing demand for global food supply and security, there is a growing need to improve agricultural production systems and increase crop productivity. Globally, bacterial pathogen infection in crop plants is one of the major contributors to agricultural yield losses. Climate change also adds to the problem by accelerating the spread of plant diseases. Hence, developing methods for rapid and early detection of pathogen-infected crops is important to improve plant disease management and reduce crop loss.

The breakthrough by SMART and TLL researchers offers a faster and more accurate method to detect bacterial infection in crop plants at an earlier stage, as compared to existing techniques. The new results appear in a paper titled “Rapid detection and quantification of plant innate immunity response using Raman spectroscopy” published in the journal Frontiers in Plant Science.

“The early detection of pathogen-infected crop plants is a significant step to improve plant disease management,” says Chua Nam Hai, DiSTAP co-lead principal investigator, professor, TLL deputy chair, and co-corresponding author. “It will allow the fast and selective removal of pathogen load and curb the further spread of disease to other neighboring crops.”

Traditionally, plant disease diagnosis involves a simple visual inspection of plants for disease symptoms and severity. “Visual inspection methods are often ineffective, as disease symptoms usually manifest only at relatively later stages of infection, when the pathogen load is already high and reparative measures are limited. Hence, new methods are required for rapid and early detection of bacterial infection. The idea would be akin to having medical tests to identify human diseases at an early stage, instead of waiting for visual symptoms to show, so that early intervention or treatment can be applied,” says MIT Professor Rajeev Ram, who is a DiSTAP principal investigator and co-corresponding author on the paper.

While existing techniques, such as current molecular detection methods, can detect bacterial infection in plants, they are often limited in their use. Molecular detection methods largely depend on the availability of pathogen-specific gene sequences or antibodies to identify bacterial infection in crops; the implementation is also time-consuming and nonadaptable for on-site field application due to the high cost and bulky equipment required, making it impractical for use in agricultural farms.

“At DiSTAP, we have developed a quantitative Raman spectroscopy-based algorithm that can help farmers to identify bacterial infection rapidly. The developed diagnostic algorithm makes use of Raman spectral biomarkers and can be easily implemented in cloud-based computing and prediction platforms. It is more effective than existing techniques as it enables accurate identification and early detection of bacterial infection, both of which are crucial to saving crop plants that would otherwise be destroyed,” explains Gajendra Pratap Singh, scientific director and principal investigator at DiSTAP and co-lead author.

A portable Raman system can be used on farms and provides farmers with an accurate and simple yes-or-no response when used to test for the presence of bacterial infections in crops. The development of this rapid and noninvasive method could improve plant disease management and have a transformative impact on agricultural farms by efficiently reducing agricultural yield loss and increasing productivity.

“Using the diagnostic algorithm method, we experimented on several edible plants such as choy sum,” says DiSTAP and TLL principal investigator and co-corresponding author Rajani Sarojam. “The results showed that the Raman spectroscopy-based method can swiftly detect and quantify innate immunity response in plants infected with bacterial pathogens. We believe that this technology will be beneficial for agricultural farms to increase their productivity by reducing their yield loss due to plant diseases.”

The researchers are currently working on the development of high-throughput, custom-made portable or hand-held Raman spectrometers that will allow Raman spectral analysis to be quickly and easily performed on field-grown crops.

SMART and TLL developed and discovered the diagnostic algorithm and Raman spectral biomarkers. TLL also confirmed and validated the detection method through mutant plants. The research is carried out by SMART and supported by the National Research Foundation of Singapore under its Campus for Research Excellence And Technological Enterprise (CREATE) program.

SMART was established by MIT and the NRF in 2007. 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: Antimicrobial Resistance, Critical Analytics for Manufacturing Personalized-Medicine, DiSTAP, Future Urban Mobility, and Low Energy Electronic Systems. SMART research is funded by the NRF under the CREATE program.

Led by Professor Michael Strano of MIT and Professor Chua Nam Hai of Temasek Lifesciences Laboratory, the DiSTAP program addresses deep problems in food production in Singapore and the world by developing a suite of impactful and novel analytical, genetic, and biomaterial technologies. The goal is to fundamentally change how plant biosynthetic pathways are discovered, monitored, engineered, and ultimately translated to meet the global demand for food and nutrients. Scientists from MIT, TTL, Nanyang Technological University, and National University of Singapore are collaboratively developing new tools for the continuous measurement of important plant metabolites and hormones for novel discovery, deeper understanding and control of plant biosynthetic pathways in ways not yet possible, especially in the context of green leafy vegetables; leveraging these new techniques to engineer plants with highly desirable properties for global food security, including high-yield density production, and drought and pathogen resistance; and applying these technologies to improve urban farming.

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MIT Future Founders Initiative announces prize competition to promote female entrepreneurs in biotech

In a fitting sequel to its entrepreneurship “boot camp” educational lecture series last fall, the MIT Future Founders Initiative has announced the MIT Future Founders Prize Competition, supported by Northpond Ventures, and named the MIT faculty cohort that will participate in this year’s competition. The Future Founders Initiative was established in 2020 to promote female entrepreneurship in biotech.

Despite increasing representation at MIT, female science and engineering faculty found biotech startups at a disproportionately low rate compared with their male colleagues, according to research led by the initiative’s founders, MIT Professor Sangeeta Bhatia, MIT Professor and President Emerita Susan Hockfield, and MIT Amgen Professor of Biology Emerita Nancy Hopkins. In addition to highlighting systemic gender imbalances in the biotech pipeline, the initiative’s founders emphasize that the dearth of female biotech entrepreneurs represents lost opportunities for society as a whole — a bottleneck in the proliferation of publicly accessible medical and technological innovation.

“A very common myth is that representation of women in the pipeline is getting better with time … We can now look at the data … and simply say, ‘that’s not true’,” said Bhatia, who is the John and Dorothy Wilson Professor of Health Sciences and Technology and Electrical Engineering and Computer Science, and a member of MIT’s Koch Institute for Integrative Cancer Research and the Institute for Medical Engineering and Science, in an interview for the March/April 2021 MIT Faculty Newsletter. “We need new solutions. This isn’t just about waiting and being optimistic.”

Inspired by generous funding from Northpond Labs, the research and development-focused affiliate of Northpond Ventures, and by the success of other MIT prize incentive competitions such as the Climate Tech and Energy Prize, the Future Founders Initiative Prize Competition will be structured as a learning cohort in which participants will be supported in commercializing their existing inventions with instruction in market assessments, fundraising, and business capitalization, as well as other programming. The program, which is being run as a partnership between the MIT School of Engineering and the Martin Trust Center for MIT Entrepreneurship, provides hands-on opportunities to learn from industry leaders about their experiences, ranging from licensing technology to creating early startup companies. Bhatia and Kit Hickey, an entrepreneur-in-residence at the Martin Trust Center and senior lecturer at the MIT Sloan School of Management, are co-directors of the program.

“The competition is an extraordinary effort to increase the number of female faculty who translate their research and ideas into real-world applications through entrepreneurship,” says Anantha Chandrakasan, dean of the MIT School of Engineering and Vannevar Bush Professor of Electrical Engineering and Computer Science. “Our hope is that this likewise serves as an opportunity for participants to gain exposure and experience to the many ways in which they could achieve commercial impact through their research.”

At the end of the program, the cohort members will pitch their ideas to a selection committee composed of MIT faculty, biotech founders, and venture capitalists. The grand prize winner will receive $250,000 in discretionary funds, and two runners-up will receive $100,000. The winners will be announced at a showcase event, at which the entire cohort will present their work. All participants will also receive a $10,000 stipend for participating in the competition.

“The biggest payoff is not identifying the winner of the competition,” says Bhatia. “Really, what we are doing is creating a cohort … and then, at the end, we want to create a lot of visibility for these women and make them ‘top of mind’ in the community.”

The Selection Committee members for the MIT Future Founders Prize Competition are:

• Bill Aulet, professor of the practice in the MIT Sloan School of Management and managing director of the Martin Trust Center for MIT Entrepreneurship
• Sangeeta Bhatia, the John and Dorothy Wilson Professor of Electrical Engineering and Computer Science at MIT; a member of MIT’s Koch Institute for Integrative Cancer Research and the Institute for Medical Engineering and Science; and founder of Hepregen, Glympse Bio, and Satellite Bio
• Kit Hickey, senior lecturer in the MIT Sloan School of Management and entrepreneur-in-residence at the Martin Trust Center
• Susan Hockfield, MIT president emerita and professor of neuroscience
• Andrea Jackson, director at Northpond Ventures
• Harvey Lodish, professor of biology and biomedical engineering at MIT and founder of Genzyme, Millennium, and Rubius
• Fiona Murray, associate dean for innovation and inclusion in the MIT Sloan School of Management; the William Porter Professor of Entrepreneurship; co-director of the MIT Innovation Initiative; and faculty director of the MIT Legatum Center
• Amy Schulman, founding CEO of Lyndra Therapeutics and partner at Polaris Partners
• Nandita Shangari, managing director at Novartis Venture Fund

“As an investment firm dedicated to supporting entrepreneurs, we are acutely aware of the limited number of companies founded and led by women in academia. We believe humanity should be benefiting from brilliant ideas and scientific breakthroughs from women in science, which could address many of the world’s most pressing problems. Together with MIT, we are providing an opportunity for women faculty members to enhance their visibility and gain access to the venture capital ecosystem,” says Andrea Jackson, director at Northpond Ventures.

“This first cohort is representative of the unrealized opportunity this program is designed to capture. While it will take a while to build a robust community of connections and role models, I am pleased and confident this program will make entrepreneurship more accessible and inclusive to our community, which will greatly benefit society,” says Susan Hockfield, MIT president emerita.

The MIT Future Founders Prize Competition cohort members were selected from schools across MIT, including the School of Science, the School of Engineering, and Media Lab within the School of Architecture and Planning. They are:

Polina Anikeeva is professor of materials science and engineering and brain and cognitive sciences, an associate member of the McGovern Institute for Brain Research, and the associate director of the Research Laboratory of Electronics. She is particularly interested in advancing the possibility of future neuroprosthetics, through biologically-informed materials synthesis, modeling, and device fabrication. Anikeeva earned her BS in biophysics from St. Petersburg State Polytechnic University and her PhD in materials science and engineering from MIT.

Natalie Artzi is principal research scientist in the Institute of Medical Engineering and Science and an assistant professor in the department of medicine at Brigham and Women’s Hospital. Through the development of smart materials and medical devices, her research seeks to “personalize” medical interventions based on the specific presentation of diseased tissue in a given patient. She earned both her BS and PhD in chemical engineering from the Technion-Israel Institute of Technology.

Laurie A. Boyer is professor of biology and biological engineering in the Department of Biology. By studying how diverse molecular programs cross-talk to regulate the developing heart, she seeks to develop new therapies that can help repair cardiac tissue. She earned her BS in biomedical science from Framingham State University and her PhD from the University of Massachusetts Medical School.

Tal Cohen is associate professor in the departments of Civil and Environmental Engineering and Mechanical Engineering. She wields her understanding of how materials behave when they are pushed to their extremes to tackle engineering challenges in medicine and industry. She earned her BS, MS, and PhD in aerospace engineering from the Technion-Israel Institute of Technology.

Canan Dagdeviren is assistant professor of media arts and sciences and the LG Career Development Professor of Media Arts and Sciences. Her research focus is on creating new sensing, energy harvesting, and actuation devices that can be stretched, wrapped, folded, twisted, and implanted onto the human body while maintaining optimal performance. She earned her BS in physics engineering from Hacettepe University, her MS in materials science and engineering from Sabanci University, and her PhD in materials science and engineering from the University of Illinois at Urbana-Champaign.

Ariel Furst is the Raymond (1921) & Helen St. Laurent Career Development Professor in the Department of Chemical Engineering. Her research addresses challenges in global health and sustainability, utilizing electrochemical methods and biomaterials engineering. She is particularly interested in new technologies that detect and treat disease. Furst earned her BS in chemistry at the University of Chicago and her PhD at Caltech.

Kristin Knouse is assistant professor in the Department of Biology and the Koch Institute for Integrative Cancer Research. She develops tools to investigate the molecular regulation of organ injury and regeneration directly within a living organism with the goal of uncovering novel therapeutic avenues for diverse diseases. She earned her BS in biology from Duke University, her PhD and MD through the Harvard and MIT MD-PhD program.

Elly Nedivi is the William R. (1964) & Linda R. Young Professor of Neuroscience at the Picower Institute for Learning and Memory with joint appointments in the departments of Brain and Cognitive Sciences and Biology. Through her research of neurons, genes, and proteins, Nedivi focuses on elucidating the cellular mechanisms that control plasticity in both the developing and adult brain. She earned her BS in biology from Hebrew University and her PhD in neuroscience from Stanford University.

Ellen Roche is associate professor in the Department of Mechanical Engineering and Institute of Medical Engineering and Science, and the W.M. Keck Career Development Professor in Biomedical Engineering. Borrowing principles and design forms she observes in nature, Roche works to develop implantable therapeutic devices that assist cardiac and other biological function. She earned her bachelor’s degree in biomedical engineering from the National University of Ireland at Galway, her MS in bioengineering from Trinity College Dublin, and her PhD from Harvard University.

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Rewriting the operating manual

Suppose you were designing a system to allocate organ donations for the greater good. From one perspective, an optimized program might give organs to the youngest possible recipient, to maximize the number of life-years gained from each organ donation.

However, such a system would likely be regarded as discriminatory based on its use of age, and would be unlikely to gain society-wide approval.

“That’s not going to be acceptable in practice,” says Nikos Trichakis, an associate professor at the MIT Sloan School of Management.

This kind of problem, broadly speaking, is one of many in which efficiency — in this case, perhaps gaining the most life-years from organ donations — can lie in tension with fairness, defined as a reasonable access to goods among many groups within society.

The tension between efficiency and fairness can seem intractable. But actually, there are ways to design systems that tackle it. That’s what Trichakis does. Over the last decade he has published research analyzing variations of this problem in many areas of life, from liver-transplant policy and scheduling infusions in cancer centers to corporate-finance decisions.

“I think one of the innovations my work is bringing is applying optimization and quantitative thinking and analytics in real-world domains in a way that respects fairness, equity, and things that society expects,” Trichakis says.

For his research and teaching, Trichakis was awarded tenure at MIT last year.

A family of engineers

Trichakis is a native of Greece who grew up in a family of engineers, something that heavily influenced his own career trajectory.

“I was raised in a family where literally everyone was an engineer, my uncles, my parents,” Trichakis says. “So I guess I have the virus of problem-solving.” He received his undergraduate degree in electrical engineering at Aristotle University, in Thessaloniki, but over time found that his interests did not lie strictly within the field.

“I started studying electrical engineering myself, but I always liked math, and the way I think about my research is as something that lies at that intersection,” Trichakis notes. “For me, these are the two things that have always excited me.”

Partly following the example of a friend, Trichakis enrolled in a master’s program at Stanford University, where he realized that operations research was located precisely at that same intersection, and decided to pursue it further. He received another master’s degree from Imperial College, London, then enrolled in MIT Sloan’s PhD program.

At Sloan, Trichakis worked with Dimitris Bertsimas and Vivek Farias, two leading operations research scholars, receiving his PhD in 2011. In the time since then, he has gone on to publish widely cited papers with them, among other colleagues; in all, Trichakis has published over two dozen peer-reviewed articles.

In one 2013 paper published in Operations Research, “Fairness, Efficiency, and Flexibility in Organ Allocation for Kidney Transplanation,” Trichakis, Bertsimas, and Farias introduced a organ transplantation system which, rather than narrowing the criteria for fairness or efficiency in transplants, in effect broadened them, by letting policymakers construct a priority system using a point scale based on many factors, including medical urgency, the waiting time for a transplant, and more.

That system, they found, would deliver an 8 percent increase in life-years gained from a given set of transplants, while meeting all the fairness criteria specified by U.S. federal policymakers.

“When there is scarcity, there is very often a tradeoff between efficiency objectives and also fairness,” Trichakis notes. “But the reason you see these gains is really the power of quantitative thinking, the power of optimization, and the power of analytics.”

And in one widely-cited Management Science paper from 2012, “On the Fairness-Efficiency Tradeoff,” the three scholars outlined a larger framework for assessing these systems across a variety of domans, from air traffic control to call-center operations and health care scheduling. The most efficient air-traffic schedule at a given airport might favor particular airlines, for instance, but in quantifying that, analysts and policymakers can at least measure what the scholars call “the price of fairness,” and develop systems that stakeholders can agree upon.

Why more debt requires more discipline

Trichakis joined the MIT faculty in 2016, having served on the faculty at Harvard University from 2011 to 2016. At the Institute, he has continued to conduct research on a diverse set of problems. For instance, in one 2017 paper in Management Science, written with Dan Iancu and Gerry Tsoukalas, Trichakis and his co-authors found, a bit paradoxically, that leveraged firms need the most discipline about handling their own inventories. Firms operating with significant debt may be inclined to liquidate inventories, but then quickly find themselves losing value, having reduced their scope of operations.

Still, Trichakis continues to focus on health care as a significant area of his research. In a 2020 paper in Transplantation, Trichakis, Bertsimas, and four co-authors found that a “continuous distribution” framework for allocating organ transplants — the one that considers many factors at once — also serves to reduce the geographic challenges in liver transplant allocation systems. They estimate a more broad-multifactor system would save 500 lives per year, creating “the greatest reduction in patient deaths and … the most equitable geographic distribution across comparable organ transportation burden.”

As the Covid-19 pandemic continues, Trichakis is also examining treatment and vaccine distribution issues with the same framework. But whatever the topic, he will keep using operations research tools to find ways that society can distribute its scarce resources with acceptable levels of both efficiency and fairness for all.

“You can solve real problems in a very wide range of application domains, all the way from societal and policymaking problems to operational problems within a particular industry,” says Trichakis.

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Community policing in the Global South

Community policing is meant to combat citizen mistrust of the police force. The concept was developed in the mid-20th century to help officers become part of the communities they are responsible for. The hope was that such presence would create a partnership between citizens and the police force, leading to reduced crime and increased trust. Studies in the 1990s from the United States, United Kingdom, and Australia showed that these goals can be achieved in certain circumstances. Many metropolitan areas in the Global North have since included community policing in their techniques.

But a recently published study of six different sites in the Global South showed no significant positive effect associated with community policing across a range of countries.

“We found no reduction in crime or insecurity in these communities, and no increase in trust in the police,” says Fotini Christia, an author of the paper, which was published in Science. Christia is the Ford International Professor in the Social Sciences at MIT and the director of the Sociotechnical Systems Research Center (SSRC) within the Institute for Data, Systems, and Society (IDSS). She was one of three on the steering committee for the research, which also included lead author Graeme Blair at the University of California at Los Angeles and Jeremy Weinstein at Stanford University. Fellow MIT political scientist Lily Tsai was also a co-author on the paper.

In this study, randomized-control trials of community policing initiatives were implemented at sites in Santa Catarina State, Brazil; Medellín, Colombia; Monrovia, Liberia; Sorsogon Province, Philippines; Ugandan rural areas; and two Punjab Province districts in Pakistan. Each suite of interventions was developed based on the needs of the area but consisted of core elements of community policing such as officer recruitment and training, foot patrols, town hall meetings, and problem-oriented policing. The work was done by a collaboration of several social scientists in the United States and abroad. Major funding for this project was provided by the UK Foreign, Commonwealth and Development Office, awarded through the Evidence in Governance and Politics network.

The null results were determined after interviewing 18,382 citizens and 874 police officers involved in the experiment over six years.

The strength of these results lies in the size of the collaboration and the care taken in the research design. Input from researchers representing 22 different departments from universities around the world allowed for a broad diversity of study sites across the Global South. And the study was preregistered to establish a common approach to measurement and indicate exactly which effects the researchers were tracking, to avoid any chance of mining the data to find positive effects.

“This is a pathbreaking study across a diverse set of sites that provides a new understanding about community policing outside of the Western world” says Christopher Winship, the Diker-Tishman Professor of Sociology at Harvard University, who was not an author on the paper.

Structural overhaul

The reasons for the failure of community policing to elicit positive results were as varied as the sites themselves, but an important commonality was difficulties in implementation.

“We saw three common problems: limited resources, a lack of prioritization of the reform, and rapid rotation of officers,” says Blair. “These challenges lead to weaker implementation of community policing than we’ve seen in ‘success stories’ in the U.S. and may explain why community policing didn’t deliver the same results in these Global South contexts.”

Citizen attendance at community meetings was variable. And then, resources dedicated to following up on problems identified by citizens were scarce. Police officers in the countries represented in the study are often over-stretched, leaving them unable to adequately follow up on their community policing duties.

For example, Ugandan police stations averaged one motorbike per whole station, and outposts averaged less than one. At the study sites in Pakistan, fewer than 25 percent of issues that arose in community meetings were followed up on. The police officers tried to push the problems through to other agencies that could assist, but those agencies were also underresourced.            

There was also significant officer turnover. “In many places, we started with and trained one group of officers and ended with a completely different set of folks,” says Christia.

In the Philippines, only 25 percent of officers were still in the same post 11 months after the start of the study. Not only is it difficult to train new recruits in the methods of community policing with that rate of turnover, it also makes it extremely difficult to build community respect and familiarity with officers.

Even in the Global North, the success of community policing can vary. As part of their study, the researchers conducted a review of 43 existing randomized trials conducted since the 1970s to determine the success rate of community policing endeavors already in place.

They found that in these initiatives, problem-oriented policing reduces crime and likely improves perceptions of safety in a community, but there is mixed-to-negative evidence on the benefits of police presence on crime and perceptions of police. 

That these initiatives struggle to achieve consistently positive results in countries with better resources indicates there is significant work to be done before success can be achieved in the Global South. Improvements in policing in the Global South may require major structural overhauls of the systems to ensure resource availability, encourage community engagement, and enhance officers’ abilities to follow up on issues of concern.

“Issues of crime and violence are at the top of the policy agenda in the Global South, and this research demonstrates how universities and government partners can work together to identify the most effective strategies from improving people’s sense of safety,” says Weinstein. “While community policing strategies didn’t deliver the anticipated results on their own, the challenges in implementation point to the need for more systemic reforms that provide the necessary resources and align incentives for police to respond to citizens’ primary concerns.”

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Energy hackers give a glimpse of the postpandemic future

After going virtual in 2020, the MIT EnergyHack was back on campus last weekend in a brand-new hybrid format that saw teams participate both in person and virtually from across the globe. While the hybrid format presented new challenges to the organizing team, it also allowed for one of the most diverse and inspiring iterations of the event to date.

“Organizing a hybrid event was a challenging but important goal in 2021 as we slowly come out of the pandemic, but it was great to realize the benefits of the format this year,” says Kailin Graham, a graduate student in MIT’s Technology and Policy Program and one of the EnergyHack communications directors. “Not only were we able to get students back on campus and taking advantage of those important in-person interactions, but preserving a virtual avenue meant that we were still able to hear brilliant ideas from those around the world who might not have had the opportunity to contribute otherwise, and that’s what the EnergyHack is really about.”

In fact, of the over 300 participants registered for the event, more than a third participated online, and two of the three grand prize winners participated entirely virtually. Teams of students at any degree level from any institution were welcome, and the event saw an incredible range of backgrounds and expertise, from undergraduates to MBAs, put their heads together to create innovative solutions.

This year’s event was supported by a host of energy partners both in industry and within MIT. The MIT Energy and Climate Club worked with sponsoring organizations Smartflower, Chargepoint, Edison Energy, Line Vision, Chevron, Shell, and Sterlite Power to develop seven problem statements for hackers, with each judged by representatives form their respective organization. The challenges ranged from envisioning the future of electric vehicle fueling to quantifying the social and environmental benefits of renewable energy projects.

Hackers had 36 hours to come up with a solution to one challenge, and teams then presented these solutions in a short pitch to a judging panel. Finalists from each challenge progressed to the final judging round to pitch against each other in pursuit of three grand prizes. Team COPrs came in third, receiving $1,000 for their solution to the Line Vision challenge; Crown Joules snagged second place and $1,500 for their approach to the Chargepoint problem; and Feel AMPowered took out first place and $2,000 for their innovative solution to the Smartflower challenge.

In addition to a new format, this year’s EnergyHack also featured a new emphasis on climate change impacts and the energy transition. According to Arina Khotimsky, co-managing director of EnergyHack 2021, “Moving forward after this year’s rebranding of the MIT Energy and Climate Club, we were hoping to carry this aim to EnergyHack. It was incredibly exciting to have ChargePoint and SmartFlower leading as our Sustainability Circle-tier sponsors and bringing their impactful innovations to the conversations at EnergyHack 2021.”

To the organizing team, whose members from sophomores to MBAs, this aspect of the event was especially important, and their hope was for the event to inspire a generation of young energy and climate leaders — a hope, according to them, that seems to have been fulfilled.

“I was floored by the positive feedback we received from hackers, both in-person and virtual, about how much they enjoyed the hackathon," says Graham. "It’s all thanks to our team of incredibly hardworking organizing directors who made EnergyHack 2021 what it was. It was incredibly rewarding seeing everyone’s impact on the event, and we are looking forward to seeing how it evolves in the future.”_­­­

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Ronald Kurtz, philanthropist and MIT Corporation life member emeritus, dies at 89

Ronald Kurtz '54, '59, SM '60, a materials manufacturer with a great love of art, died on Nov. 20. He was 89.

Kurtz earned three degrees at MIT — a bachelor's degree in industrial management and bachelor's and master's degrees in metallurgy — all of which contributed to his keen interest in art and his extensive involvement with the Institute.

"I will remember him for his profound commitment to forging strong ties between art, science, and technology," says Philip Khoury, associate provost and the Ford International Professor of History at MIT. "He understood that it's at their intersection that MIT has made its most profound contributions to the arts worldwide. He began to discover this reality during his undergraduate years as he pursued the study of material sciences and engineering, always with an eye on art and design."  

Kurtz offered support to the Center for Art, Science and Technology by commissioning a course in honor of his mentor, Professor Merton C. Flemings, that explored the connections between art, design, and materials science. He served on the Council for the Arts at MIT; was a passionate supporter of the MIT Museum; and provided funding for exhibitions through the Kurtz Gallery for Photography. His support for MIT also included graduate fellowships and service on visiting committees and advisory bodies representing a broad range of departments not directly related to the arts. Kurtz joined the Corporation in 1994. He won the MIT Alumni Association's Bronze Beaver award for distinguished service in 2002.

“Ron was an extraordinary force in the world,” President L. Rafael Reif wrote to the Kurtz family. “His curiosity and humility led him to unexpected places and ideas, including appreciating the powerful synchronicity between science and art.” 

"Ron Kurtz was a steadfast friend to MIT since he arrived on campus in 1950," says Diane Greene, chair of the MIT Corporation. "His service to MIT was vast, and through his volunteer work and support he inspired and elevated countless programs and departments throughout our campus. His work on MIT’s visiting committees, his establishment of graduate fellowships and undergraduate scholarships, his advocacy for the arts at MIT and the MIT Museum, and his role as a life member emeritus of the MIT Corporation represent only a fraction of his impact. Ron affected the lives of so many members of the Institute community; he brought humaneness, enthusiasm, and excellence to all that he did. The Institute is better for the seven decades of his creativity, curiosity, and guidance."

At the time of Kurtz's transfer to life member emeritus of the MIT Corporation in 2007, former MIT president Paul Gray (who passed away in 2017) referred to Kurtz as a "modest, kindly, and thoughtful man, he is the epitome of a dedicated and grateful alumnus."

Kurtz attended high school in Teaneck, New Jersey, and then was admitted to MIT to earn his first bachelor's degree. After serving in the U.S. Air Force, he returned to MIT to earn his second bachelor's degree and his master's. He began his industrial career as a materials engineer with Nuclear Metals, Inc. and then joined Kulite Tungsten Corporation, where he spent the next 35 years building the company into a global leader in the manufacture of tungsten alloys used in the aerospace, medical, electronics, and sporting goods industries. He retired from Kulite in 1997 as president and CEO.

To cultivate his passion for photography, Kurtz began acquiring a vast knowledge, as well as works by Ansel Adams, Abbott, and Arnold Newman. He bought the archive of Abbott — especially known for her "Nightview, New York," as well as for the most widely known portraits of James Joyce — in the 1980s, and founded a publishing company called Commerce Graphics, ultimately becoming a dealer and distributor of fine art photographs and prints.

"When you have more than fits on the wall, you are a collector," Kurtz was quoted as saying in an MIT News Magazine article published by Technology Review in 2008. "If you have more than fits in a drawer, you are a dealer."  

For years, he and his wife, Carol Kurtz, welcomed and hosted many newcomers to the MIT community. They also supported outreach by the Minority Introduction to Engineering and Science (MITES) program, which offers summer enrichment in science, technology, engineering, and mathematics to students from underrepresented or underserved communities.

Kurtz’ desire to give back and to help others was a defining trait. "Above all, I will remember Ron for his compassion for those most in need of our understanding and support," Khoury says. "I feel privileged to have known Ron Kurtz and to have been his friend."

Kurtz is survived by his wife and his children, David (and Shelly) Kurtz, Jillian (and Jeremy) Temkin, and Daniel (and Wendy McKee) Kurtz, and his grandchildren, Alisa (and Trevor) Gilbert, Nicole Kurtz, Jake (Madelyn) Temkin, Andrew Kurtz, and Max Temkin.

Donations in Kurtz’ memory may be made to the MIT Scholarship Fund, Doctors Without Borders, or the Center for Food Action.

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Featured video: A musical encore for a re-imagined library

When MIT’s Hayden Library was originally dedicated in 1950, Czech-born composer Bohuslav Martinů was commissioned to write his “Piano Trio in D Minor” to mark the occasion. The piece received its world premiere in a performance by MIT professors Klaus Liepmann on violin and Gregory Tucker on piano, and George Finckel of Bennington College on cello.

Seventy-one years later, the MIT Libraries celebrated the renovation of Hayden Library as a trio of current graduate students performed a movement from the piece. Calvin Leung (cello), a PhD student in physics; William Wang (piano), a PhD student in computer science; and Katherine Young (violin), a student in the Harvard-MIT Program in Health Sciences and Technology, played for a small audience in the Nexus, Hayden’s new event space. 

“Hearing Martinů’s music brought to life by these wonderful musicians felt like the perfect way to inaugurate this new gathering space for the community,” says Nina Davis-Millis, director of community engagement at MIT Libraries. 

The MIT Libraries' Distinctive Collections owns sketches of the piano trio in Martinů’s hand, as well as the published version of the score, which carries the simple epigraph, “à MIT Cambridge.”

Video by MIT Video Productions with thanks to MIT Music and Theater Arts.
 

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Timber or steel? Study helps builders reduce carbon footprint of truss structures

Buildings are a big contributor to global warming, not just in their ongoing operations but in the materials used in their construction. Truss structures — those crisscross arrays of diagonal struts used throughout modern construction, in everything from antenna towers to support beams for large buildings — are typically made of steel or wood or a combination of both. But little quantitative research has been done on how to pick the right materials to minimize these structures’ contribution global warming.

The “embodied carbon” in a construction material includes the fuel used in the material’s production (for mining and smelting steel, for example, or for felling and processing trees) and in transporting the materials to a site. It also includes the equipment used for the construction itself.

Now, researchers at MIT have done a detailed analysis and created a set of computational tools to enable architects and engineers to design truss structures in a way that can minimize their embodied carbon while maintaining all needed properties for a given building application. While in general wood produces a much lower carbon footprint, using steel in places where its properties can provide maximum benefit can provide an optimized result, they say.

The analysis is described in a paper published today in the journal Engineering Structures, by graduate student Ernest Ching and MIT assistant professor of civil and environmental engineering Josephine Carstensen.

“Construction is a huge greenhouse gas emitter that has kind of been flying under the radar for the past decades,” says Carstensen. But in recent years building designers “are starting to be more focused on how to not just reduce the operating energy associated with building use, but also the important carbon associated with the structure itself.” And that’s where this new analysis comes in.

The two main options in reducing the carbon emissions associated with truss structures, she says, are substituting materials or changing the structure. However, there has been “surprisingly little work” on tools to help designers figure out emissions-minimizing strategies for a given situation, she says.

The new system makes use of a technique called topology optimization, which allows for the input of basic parameters, such as the amount of load to be supported and the dimensions of the structure, and can be used to produce designs optimized for different characteristics, such as weight, cost, or, in this case, global warming impact.

Wood performs very well under forces of compression, but not as well as steel when it comes to tension — that is, a tendency to pull the structure apart. Carstensen says that in general, wood is far better than steel in terms of embedded carbon, so “especially if you have a structure that doesn't have any tension, then you should definitely only use timber” in order to minimize emissions. One tradeoff is that “the weight of the structure is going to be bigger than it would be with steel,” she says.

The tools they developed, which were the basis for Ching’s master’s thesis, can be applied at different stages, either in the early planning phase of a structure, or later on in the final stages of a design.

As an exercise, the team developed a proposal for reengineering several trusses using these optimization tools, and demonstrated that a significant savings in embodied greenhouse gas emissions could be achieved with no loss of performance. While they have shown improvements of at least 10 percent can be achieved, she says those estimates are “not exactly apples to apples” and likely savings could actually be two to three times that.

“It’s about choosing materials more smartly,” she says, for the specifics of a given application. Often in existing buildings “you will have timber where there’s compression, and where that makes sense, and then it will have really skinny steel members, in tension, where that makes sense. And that’s also what we see in our design solutions that are suggested, but perhaps we can see it even more clearly.” The tools are not ready for commercial use though, she says, because they haven’t yet added a user interface.

Carstensen sees a trend to increasing use of timber in large construction, which represents an important potential for reducing the world’s overall carbon emissions. “There’s a big interest in the construction industry in mass timber structures, and this speaks right into that area. So, the hope is that this would make inroads into the construction business and actually make a dent in that very large contribution to greenhouse gas emissions.”

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Artificial intelligence that understands object relationships

When humans look at a scene, they see objects and the relationships between them. On top of your desk, there might be a laptop that is sitting to the left of a phone, which is in front of a computer monitor.

Many deep learning models struggle to see the world this way because they don’t understand the entangled relationships between individual objects. Without knowledge of these relationships, a robot designed to help someone in a kitchen would have difficulty following a command like “pick up the spatula that is to the left of the stove and place it on top of the cutting board.”

In an effort to solve this problem, MIT researchers have developed a model that understands the underlying relationships between objects in a scene. Their model represents individual relationships one at a time, then combines these representations to describe the overall scene. This enables the model to generate more accurate images from text descriptions, even when the scene includes several objects that are arranged in different relationships with one another.

This work could be applied in situations where industrial robots must perform intricate, multistep manipulation tasks, like stacking items in a warehouse or assembling appliances. It also moves the field one step closer to enabling machines that can learn from and interact with their environments more like humans do.

“When I look at a table, I can’t say that there is an object at XYZ location. Our minds don’t work like that. In our minds, when we understand a scene, we really understand it based on the relationships between the objects. We think that by building a system that can understand the relationships between objects, we could use that system to more effectively manipulate and change our environments,” says Yilun Du, a PhD student in the Computer Science and Artificial Intelligence Laboratory (CSAIL) and co-lead author of the paper.

Du wrote the paper with co-lead authors Shuang Li, a CSAIL PhD student, and Nan Liu, a graduate student at the University of Illinois at Urbana-Champaign; as well as Joshua B. Tenenbaum, the Paul E. Newton Career Development Professor of Cognitive Science and Computation in the Department of Brain and Cognitive Sciences and a member of CSAIL; and senior author Antonio Torralba, the Delta Electronics Professor of Electrical Engineering and Computer Science and a member of CSAIL. The research will be presented at the Conference on Neural Information Processing Systems in December.

One relationship at a time

The framework the researchers developed can generate an image of a scene based on a text description of objects and their relationships, like “A wood table to the left of a blue stool. A red couch to the right of a blue stool.”

Their system would break these sentences down into two smaller pieces that describe each individual relationship (“a wood table to the left of a blue stool” and “a red couch to the right of a blue stool”), and then model each part separately. Those pieces are then combined through an optimization process that generates an image of the scene.

The researchers used a machine-learning technique called energy-based models to represent the individual object relationships in a scene description. This technique enables them to use one energy-based model to encode each relational description, and then compose them together in a way that infers all objects and relationships.

By breaking the sentences down into shorter pieces for each relationship, the system can recombine them in a variety of ways, so it is better able to adapt to scene descriptions it hasn’t seen before, Li explains.

“Other systems would take all the relations holistically and generate the image one-shot from the description. However, such approaches fail when we have out-of-distribution descriptions, such as descriptions with more relations, since these model can’t really adapt one shot to generate images containing more relationships. However, as we are composing these separate, smaller models together, we can model a larger number of relationships and adapt to novel combinations,” Du says.

The system also works in reverse — given an image, it can find text descriptions that match the relationships between objects in the scene. In addition, their model can be used to edit an image by rearranging the objects in the scene so they match a new description.

Understanding complex scenes

The researchers compared their model to other deep learning methods that were given text descriptions and tasked with generating images that displayed the corresponding objects and their relationships. In each instance, their model outperformed the baselines.

They also asked humans to evaluate whether the generated images matched the original scene description. In the most complex examples, where descriptions contained three relationships, 91 percent of participants concluded that the new model performed better.

“One interesting thing we found is that for our model, we can increase our sentence from having one relation description to having two, or three, or even four descriptions, and our approach continues to be able to generate images that are correctly described by those descriptions, while other methods fail,” Du says.

The researchers also showed the model images of scenes it hadn’t seen before, as well as several different text descriptions of each image, and it was able to successfully identify the description that best matched the object relationships in the image.

And when the researchers gave the system two relational scene descriptions that described the same image but in different ways, the model was able to understand that the descriptions were equivalent.

The researchers were impressed by the robustness of their model, especially when working with descriptions it hadn’t encountered before.

“This is very promising because that is closer to how humans work. Humans may only see several examples, but we can extract useful information from just those few examples and combine them together to create infinite combinations. And our model has such a property that allows it to learn from fewer data but generalize to more complex scenes or image generations,” Li says.

While these early results are encouraging, the researchers would like to see how their model performs on real-world images that are more complex, with noisy backgrounds and objects that are blocking one another.

They are also interested in eventually incorporating their model into robotics systems, enabling a robot to infer object relationships from videos and then apply this knowledge to manipulate objects in the world.

“Developing visual representations that can deal with the compositional nature of the world around us is one of the key open problems in computer vision. This paper makes significant progress on this problem by proposing an energy-based model that explicitly models multiple relations among the objects depicted in the image. The results are really impressive,” says Josef Sivic, a distinguished researcher at the Czech Institute of Informatics, Robotics, and Cybernetics at Czech Technical University, who was not involved with this research.

This research is supported, in part, by Raytheon BBN Technologies Corp., Mitsubishi Electric Research Laboratory, the National Science Foundation, the Office of Naval Research, and the IBM Thomas J. Watson Research Center.

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How molecular clusters in the nucleus interact with chromosomes

A cell stores all of its genetic material in its nucleus, in the form of chromosomes, but that’s not all that’s tucked away in there. The nucleus is also home to small bodies called nucleoli — clusters of proteins and RNA that help build ribosomes.

Using computer simulations, MIT chemists have now discovered how these bodies interact with chromosomes in the nucleus, and how those interactions help the nucleoli exist as stable droplets within the nucleus.

Their findings also suggest that chromatin-nuclear body interactions lead the genome to take on a gel-like structure, which helps to promote stable interactions between the genome and transcription machineries. These interactions help control gene expression.

“This model has inspired us to think that the genome may have gel-like features that could help the system encode important contacts and help further translate those contacts into functional outputs,” says Bin Zhang, the Pfizer-Laubach Career Development Associate Professor of Chemistry at MIT, an associate member of the Broad Institute of Harvard and MIT, and the senior author of the study.

MIT graduate student Yifeng Qi is the lead author of the paper, which appears today in Nature Communications.

Modeling droplets

Much of Zhang’s research focuses on modeling the three-dimensional structure of the genome and analyzing how that structure influences gene regulation.

In the new study, he wanted to extend his modeling to include the nucleoli. These small bodies, which break down at the beginning of cell division and then re-form later in the process, consist of more than a thousand different molecules of RNA and proteins. One of the key functions of the nucleoli is to produce ribosomal RNA, a component of ribosomes.

Recent studies have suggested that nucleoli exist as multiple liquid droplets. This was puzzling because under normal conditions, multiple droplets should eventually fuse together into one large droplet, to minimize the surface tension of the system, Zhang says.

“That’s where the problem gets interesting, because in the nucleus, somehow those multiple droplets can remain stable across an entire cell cycle, over about 24 hours,” he says.

To explore this phenomenon, Zhang and Qi used a technique called molecular dynamics simulation, which can model how a molecular system changes over time. At the beginning of the simulation, the proteins and RNA that make up the nucleoli are randomly distributed throughout the nucleus, and the simulation tracks how they gradually form small droplets.

In their simulation, the researchers also included chromatin, the substance that makes up chromosomes and incudes proteins as well as DNA. Using data from previous experiments that analyzed the structure of chromosomes, the MIT team calculated the interaction energy of individual chromosomes, which allowed them to provide realistic representations of 3D genome structures.

Using this model, the researchers were able to observe how nucleoli droplets form. They found that if they modeled the nucleolar components on their own, with no chromatin, they would eventually fuse into one large droplet, as expected. However, once chromatin was introduced into the model, the researchers found that the nucleoli formed multiple droplets, just as they do in living cells.

The researchers also discovered why that happens: The nucleoli droplets become tethered to certain regions of the chromatin, and once that happens, the chromatin acts as a drag that prevents the nucleoli from fusing to each other.

“Those forces essentially arrest the system into those small droplets and hinder them from fusing together,” Zhang says. “Our study is the first to highlight the importance of this chromatin network that could significantly slow down the fusion and arrest the system in its droplet state.”

Gene control
 

The nucleoli are not the only small structures found in the nucleus — others include nuclear speckles and the nuclear lamina, an envelope that surrounds the genome and can bind to chromatin. Zhang’s group is now working on modeling the contributions of these nuclear structures, and their initial findings suggest that they help to give the genome more gel-like properties, Zhang says.

“This coupling that we have observed between chromatin and nuclear bodies is not specific to the nucleoli. It’s general to other nuclear bodies as well,” he says. “This nuclear body concentration will fundamentally change the dynamics of the genome organization and will very likely turn the genome from a liquid to a gel.”

This gel-like state would make it easier for different regions of the chromatin to interact with each other than if the structure existed in a liquid state, he says. Maintaining stable interactions between distant regions of the genome is important because genes are often controlled by stretches of chromatin that are physically distant from them.

The research was funded by the National Institutes of Health and the Gordon and Betty Moore Foundation.

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One year on this giant, blistering hot planet is just 16 hours long

The hunt for planets beyond our solar system has turned up more than 4,000 far-flung worlds, orbiting stars thousands of  light years from Earth. These extrasolar planets are a veritable menagerie, from rocky super-Earths and miniature Neptunes to colossal gas giants.

Among the more confounding planets discovered to date are “hot Jupiters” —  massive balls of gas that are about the size of our own Jovian planet but that zing around their stars in less than 10 days, in contrast to Jupiter’s plodding, 12-year orbit. Scientists have discovered about 400 hot Jupiters to date. But exactly how these weighty whirlers came to be remains one of the biggest unsolved mysteries in planetary science.

Now, astronomers have discovered one of the most extreme ultrahot Jupiters  — a gas giant that is about five times Jupiter’s mass and blitzes around its star in just 16 hours. The planet’s orbit is the shortest of any known gas giant to date.

Due to its extremely tight orbit and proximity to its star, the planet’s day side is estimated to be at around 3,500 Kelvin, or close to 6,000 degrees Fahrenheit — about as hot as a small star. This makes the planet, designated TOI-2109b, the second hottest detected so far.

Judging from its properties, astronomers believe that TOI-2109b is in the process of “orbital decay,” or spiraling into its star, like bathwater circling the drain. Its extremely short orbit is predicted to cause the planet to spiral toward its star faster than other hot Jupiters.

The discovery, which was made initially by NASA’s Transiting Exoplanet Survey Satellite (TESS), an MIT-led mission, presents a unique opportunity for astronomers to study how planets behave as they are drawn in and swallowed by their star.

“In one or two years, if we are lucky, we may be able to detect how the planet moves closer to its star,” says Ian Wong, lead author of the discovery, who was a postdoc at MIT during the study and has since moved to NASA Goddard Space Flight Center.  “In our lifetime we will not see the planet fall into its star. But give it another 10 million years, and this planet might not be there.”

The discovery is reported today in the Astronomical Journal and is the result of the work of a large collaboration that included members of MIT’s TESS science team and researchers from around the world.

Transit track

On May 13, 2020, NASA’s TESS satellite began observing TOI-2109, a star located in the southern portion of the Hercules constellation, about 855 light years from Earth. The star was identified by the mission as the 2,109th “TESS Object of Interest,” for the possibility that it might host an orbiting planet.

Over nearly a month, the spacecraft collected measurements of the star’s light, which the TESS science team then analyzed for transits — periodic dips in starlight that might indicate a planet passing in front of and briefly blocking a small fraction of the star’s light. The data from TESS confirmed that the star indeed hosts an object that transits about every 16 hours.

The team notified the wider astronomy community, and shortly after, multiple ground-based telescopes followed up over the next year to observe the star more closely over a range of frequency bands. These observations, combined with TESS’ initial detection, confirmed the transiting object as an orbiting planet, which was designated TOI-2109b.

“Everything was consistent with it being a planet, and we realized we had something very interesting and relatively rare,” says study co-author Avi Shporer, a research scientist at MIT’s Kavli Institute for Astrophysics and Space Research.

Day and night

By analyzing measurements over various optical and infrared wavelengths, the team determined that TOI-2109b is about five times as massive as Jupiter, about 35 percent larger, and extremely close to its star, at a distance of about 1.5 million miles out. Mercury, by comparison, is around 36 million miles from the Sun.

The planet’s star is roughly 50 percent larger in size and mass compared to our Sun. From the observed properties of the system, the researchers estimated that TOI-2109b is spiraling into its star at a rate of 10 to 750 milliseconds per year — faster than any hot Jupiter yet observed.

Given the planet’s dimensions and proximity to its star, the researchers determined TOI-2109b to be an ultrahot Jupiter, with the shortest orbit of any known gas giant. Like most hot Jupiters, the planet appears to be tidally locked, with a perpetual day and night side, similar to the Moon with respect to the Earth. From the month-long TESS observations, the team was able to witness the planet’s varying brightness as it revolves about its axis. By observing the planet pass behind its star (known as a secondary eclipse) at both optical and infrared wavelengths, the  researchers estimated that the day side reaches temperatures of more than 3,500 Kelvin.

“Meanwhile, the planet’s night side brightness is below the sensitivity of the TESS data, which raises questions about what is really happening there,” Shporer says. “Is the temperature there very cold, or does the planet somehow take heat on the day side and transfer it to the night side? We’re at the beginning of trying to answer this question for these ultrahot Jupiters.”

The researchers hope to observe TOI-2109b with more powerful tools in the near future, including the Hubble Space Telescope and the soon-to-launch James Webb Space Telescope. More detailed observations could illuminate the conditions hot Jupiters undergo as they fall into their star.

“Ultrahot Jupiters such as TOI-2109b constitute the most extreme subclass of exoplanet,” Wong says. “We have only just started to understand some of the unique physical and chemical processes that occur in their atmospheres — processes that have no analogs in our own solar system.”

Future observations of TOI-2109b may also reveal clues to how such dizzying systems come to be in the first place. “From the beginning of exoplanetary science, hot Jupiters have been seen as oddballs,” Shporer says. “How does a planet as massive and large as Jupiter reach an orbit that is only a few days long? We don’t have anything like this in our solar system, and we see this as an opportunity to study them and help explain their existence.”

This research was supported, in part, by NASA.

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Report: Economics drives migration from Central America to the U.S.

A new report about migration, co-authored by MIT scholars, shows that economic distress is the main factor pushing migrants from Central America to the U.S. — and highlights the personal costs borne by people as they seek to move abroad.

“The core issue is economics, at the end of the day, and this is where policymakers need to be focusing their energy,” says Sarah Williams, an MIT professor who helped produce the report. “At the heart of what’s causing migration is that people don’t have enough money to provide for their basic needs.”

The study, based on a unique survey of over 5,000 people in El Salvador, Guatemala, and Honduras, finds a sharp increase in the number of people considering migrating after nearly two years of the Covid-19 pandemic. About 43 percent of people surveyed in 2021 were considering migrating, compared to 8 percent in 2019. That change comes as food insecurity in the region soars: The UN’s World Food Program (WFP) estimates that 6.4 million people in the three countries were suffering from food insecurity in 2021, up from 2.2 million in 2019.

Survey respondents cited low wages, unemployment, and minimal income levels as factors increasing their desire to emigrate — ahead of reasons such as violence or natural disasters. In contrast to the 43 percent of people who were considering migrating, only 3 percent of people in the survey said they had made concrete plans to migrate. But 23 percent of those experiencing food insecurity had made concrete plans to leave.

One likely reason more people do not migrate is cost: An estimated 1.8 million Central Americans have attempted to migrate in the past five years, costing them collectively about $2.2 billion per year, which is equal to about one-tenth of Honduras’ annual GDP.

“That is an extreme amount of money,” says Williams, an associate professor of technology and urban planning in MIT’s Department of Urban Studies and Planning, and director of MIT’s Leventhal Center for Advanced Urbanism. “That $2.2 billion is all paid for by the migrants themselves, so the risks, both in terms of debt and personal risk, is borne by the migrant.”

MIT’s Civic Data Design Lab, which Williams also directs, helped analyze study data, produce the report, and create data visualizations to illustrate the economics of regional migration from central America.

Providing services to two countries

The report, “Charting a New Regional Course of Action: The Complex Motivations and Costs of Central American Migration,” is the product of a collaboration between the WFP; the Migration Policy Institute (MPI), a nonpartisan think tank; and MIT’s Civic Data Design Lab. Additional funding support was provided by the Inter-American Development Bank (IDB) and the Organization of American States (OAS). The project grew in part of a food insecurity study by the WFP, who also conducted the immigration survey.

The findings are being discussed at an online forum today featuring WFP Executive Director David Beasley, OAS Secretary General Luis Almagro, and IDB President Mauricio Claver-Carone; Williams and the report authors; and the foreign ministers of El Salvador, Guatemala, and Honduras.

The report found that 89 percent of people considering migrating were looking at the U.S. as their first choice. In households where someone had tried migrating in the last five years, about 57 percent of migrants had successfully reached their destination country and stayed, while 33 percent had returned home.

About 55 percent of migrants had tried using an illegal smuggler to help them, at a cost of about $7,500 per attempt, compared to a cost of about $4,500 for those using legal means.

“Illegal pathways to migration are much more expensive than legal pathways,” Williams observes.

Whatever means migrants use, Williams also notes, the migrants themselves are bearing the cost of providing services to two countries. Migrants are a source of inexpensive labor in the U.S.; foreign-born workers made up 73 percent of all U.S.-hired crop labor workers in 2016, for instance.

But Central American countries also benefit from the labor of emigrants: Around 29 percent of households receive remittances — cash payments from immigrants living abroad, which constitute a nontrivial source of income in places like El Salvador, Guatemala, and Honduras.

“We must create incentives and opportunities for diasporas to invest in the development of local communities and become agents of change,” Williams says.

The policy possibilities

With many Central American residents at least considering immigration, the new report suggests a series of policy measures that could help their local and national economies. While the U.S. is involved in aid programs in Central America, the report’s policy suggestions emphasize economic investment tailored to local conditions, tied with increased social programs. For instance, investment in local agriculture can be linked to better support for school-food programs that use local produce.

“Targeted investment would do a lot more than just providing aid to the country,” Williams says.

The report also recommends expanding legal pathways to immigration that could simplify the entire process, and help the regional flow of labor meet demand. This includes, as the report notes, “coordinated efforts to increase access to temporary employment visas,” among other things.

Williams says the Civic Data Design Lab, which focuses on urgent social policy matters, plans to continue to examine immigration issues and related matters. This is because the root causes are complex and data can help clarify the issues for policymakers and the public. Her lab has developed a visualization website making the survey and the report more accessible to the public.

“We’re bringing the skills of MIT to an important issue, and that’s what has been so rewarding,” Williams says. “We hope this collaboration continues and are looking forward to working with the World Food Program again in the future.”

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Provost Martin Schmidt named president of Rensselaer Polytechnic Institute

MIT Provost Martin Schmidt has been named as the 19th president of Rensselaer Polytechnic Institute, the nation’s oldest technological research university.

Schmidt, who earned his BS in electrical engineering at RPI in 1981, will assume its presidency on July 1, 2022. He has spent more than 40 years at MIT as a student, faculty member, and administrative leader.

“MIT has been a remarkable home for me,” Schmidt says. “It has allowed me to pursue my research and teaching passions, and has immersed me in an environment of inspiring and dedicated staff, students, and faculty. I’ve been presented with exceptional opportunities to contribute to MIT and beyond.”

In a letter to the MIT community today, President L. Rafael Reif thanked Schmidt for his decades of committed service to MIT.

“Marty is an extraordinary citizen of MIT and one of its most gifted and dedicated servant-leaders,” Reif wrote. “I could not be more grateful for his expert counsel and his enduring friendship.”

“Very excited to return”

Located in Troy, New York, RPI was founded in 1824 to support the “application of science to the common purposes of life.” In the nearly 200 years since, many other technological universities, as well as schools and colleges of applied sciences, have emulated RPI’s model. Today, its 7,900 students take courses in five schools: architecture; management; engineering; humanities, arts, and social sciences; and science.

“When RPI approached me over the summer regarding the presidency, I was not at first convinced that it was a fit for me,” Schmidt says. “However, as I began to consider it, I came to realize that there is really something special about being given the opportunity to lead your undergraduate alma mater. My wife Lyn and I are very excited to return to a campus which we knew very well 40 years ago, and to reacquaint ourselves with the RPI community.”

In his new role as RPI’s president, Schmidt will succeed another MIT graduate: Shirley Ann Jackson ’68, PhD ’73, who has served as RPI’s president since 1999.

Four decades at MIT

“I often joke, when asked how long I’ve been at MIT, that I’ve been here my entire adult life,” Schmidt says. “I came to MIT in September 1981 as a 21-year-old graduate student, and never left.”

He earned his MS in 1983 — largely for research conducted at Lincoln Laboratory — and his PhD in 1988, both in electrical engineering and computer science (EECS). A member of the EECS faculty since 1988, Schmidt was director of MIT’s Microsystems Technology Laboratories from 1999 to 2006, and associate provost from 2008 to 2013.

Schmidt has served as provost since 2014; he is also the Ray and Maria Stata Professor of Electrical Engineering and Computer Science. The provost is MIT’s senior academic and budget officer, with overall responsibility for the Institute’s educational programs, as well as for the recruitment, promotion, and tenuring of faculty. As provost, he has worked closely with MIT’s deans to establish academic priorities, and with other members of the Institute’s senior team to manage financial planning and research support. He has also had oversight of MIT’s international engagements.

“When Marty accepted the role of provost in 2014, he was exceptionally well prepared,” President Reif wrote in his letter to the community today. “Calm, thoughtful, optimistic but appropriately cautious, with a nimble mind and an easy, unpretentious manner, he quickly became one of my closest advisors.”

Key accomplishments as provost

In his eight years as MIT’s provost, Schmidt has led many of the Institute’s efforts to foster an inclusive and well-supported community. He also played a key role in the 2018 creation of the MIT Stephen A. Schwarzman College of Computing, and in the ongoing evolution of edX.

In 2016, Schmidt began a process to reimagine MIT’s approach to building welcoming and inclusive communities. He provided leaders across campus with resources to improve the climate within their academic areas, and undertook a major restructuring of the Institute Community and Equity Office. More recently, he has overseen development of an Institute-wide Strategic Action Plan for Diversity, Equity, and Inclusion (DEI), as well as the Ad Hoc Committee on Arts, Culture, and DEI.

Working closely with former Chancellor Cynthia Barnhart, Schmidt launched the MIT Values Statement Committee and increased resources for critical student support services. He also created a new faculty development effort to offer training and coaching for faculty as they advance in leadership roles.

In 2018, Schmidt played a central role in the creation of Schwarzman College. Made possible by a $350 million gift, Schwarzman College represented the most significant organizational change at MIT in 70 years. The college aims to strengthen MIT’s core computer science activities by hiring 25 additional faculty; to bridge disciplines between computer science and other disciplines through recruitment of 25 new joint faculty; and to create a new unit to focus on the social and ethical responsibilities of computing.

Together with the provost of Harvard University, Schmidt has co-chaired the board of edX since 2014. He was deeply involved in the execution of a transformative transaction, announced in June 2021, to spin off part of edX to a commercial partner and use the $800 million proceeds to create a new nonprofit. This new nonprofit, still in development, will support an open-source learning platform and assist learners who are not well-served by current online platforms, through grant-making and partnerships.

A seasoned researcher and entrepreneur

In the 1980s, as a graduate student, Schmidt broadened his horizons beyond his early interest in microelectronics, turning his attention to miniature sensors for use in factories and vehicles. He later conducted research on sensors to detect turbulence.

As an MIT faculty member, Schmidt’s enthusiasm for interdisciplinary collaboration drew him to partner with colleagues outside his own field. Attracted to problems with practical applications, he also found himself working closely with industrial collaborators at 3M, Bosch, and General Motors.

A seasoned inventor and entrepreneur, Schmidt holds more than 30 issued U.S. patents and has played a part in starting seven companies. His entrepreneurship has its roots in the 1990s, when he cultivated an interest in microfluidics. His work to develop miniature chemical reactors gave rise to one startup; two others grew out of microfluidics research involving the manipulation of individual cells in blood.

“Marty embodies an MIT ideal — a scholar at work in the world,” President Reif wrote in his letter today.

President Reif also invited suggestions from members of the MIT community regarding the selection of MIT’s next provost. Input can be sent to provost-search@mit.edu; all correspondence will be treated as confidential.

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Peeking into a chrysalis, videos reveal growth of butterfly wing scales

If you brush against the wings of a butterfly, you will likely come away with a fine sprinkling of powder. This lepidopteran dust is made up of tiny microscopic scales, hundreds of thousands of which paper a butterfly’s wings like shingles on a wafer-thin roof. The structure and arrangement of these scales give a butterfly its color and shimmer, and help shield the insect from the elements.

Now, MIT engineers have captured the intricate choreography of butterfly scales forming during metamorphosis. The team has for the first time continuously observed the wing scales growing and assembling as a developing butterfly transforms inside its chrysalis.

With some minor surgery and a clever imaging approach, the researchers were able to watch wing scales form in specimens of Vanessa cardui, commonly known as the Painted Lady butterfly. They observed that, as a wing forms, cells on its surface line up in orderly rows as they grow. These cells quickly differentiate into alternating “cover” and “ground” scales, producing an overlapping shingle-like pattern. As they reach their full size, the scales sprout thin ridges along their length — tiny corrugated features that control the insect’s color and help it to shed rain and moisture.

The team’s study, published today in the Proceedings of the National Academy of Sciences, offers the most detailed look yet at the budding architecture of butterfly scales. The new visualizations also could serve as a blueprint for designing new functional materials, such as iridescent windows and waterproof textiles.

“Butterfly wings control many of their attributes by precisely forming the structural architecture of their wing scales,” says lead author Anthony McDougal, a research assistant in MIT’s Department of Mechanical Engineering. “This strategy might be used, for example, to give both color and self-cleaning properties to automobiles and buildings. Now we can learn from butterflies’ structural control of these complex, micro-nanostructured materials.”

McDougal’s co-authors at MIT include postdoc Sungsam Kang, research scientist Zahid Yaqoob, professor of mechanical engineering and biological engineering Peter So, and associate professor of mechanical engineering Mathias Kolle.

A firefly field

The cross-section of a butterfly’s wing reveals an intricate scaffold of scales and ribs whose structure and arrangement varies from species to species. These microscopic features act as tiny reflectors, bouncing light around to give a butterfly its color and shine. The ridges on a wing’s scales serve as miniature rain gutters and radiators, funneling moisture and heat to keep the insect cool and dry.

Researchers have tried to replicate the optical and structural properties of butterfly wings to design new solar cells and optical sensors, rain- and heat-resistant surfaces, and even paper currency patterned with iridescent encryptions to discourage counterfeiting. Knowing what processes butterflies harness to grow their scales could help to further direct this kind of bioinspired technology development.

Currently, what’s known about scale formation is based on still images of developing and mature butterfly wings.

“Previous studies provide compelling snapshots at select stages of development; unfortunately, they don’t reveal the continuous timeline and sequence of what happens as scale structures grow,” Kolle says. “We needed to see more to start understanding it better.”

In their new study, he and his colleagues looked to continuously observe how scales grow and assemble in a living, morphing butterfly. They chose to study specimens of Vanessa cardui, as the butterfly’s wings have features that are common across most lepidopteran species.

The team raised Painted Lady caterpillars in individual containers. Once each caterpillar encased itself in a chrysalis, indicating the beginning of its metamorphosis, the researchers carefully cut into the paper-thin material and peeled away a small square of cuticle, or covering of the developing wing, exposing the scales growing underneath. They then used a bioadhesive to stick a transparent coverslip over the opening, creating a window through which they could watch as the butterfly and its scales continued to form.

To visualize this transformation, Kolle and McDougal teamed up with Kang, Yaqoob, and So — experts in a type of imaging called speckle-correlation reflection phase microscopy. Rather than shine a wide beam of light on the wing, which could be phototoxic to the delicate cells, the team applied a “speckle field” — many small points of light, each shining on a specific point on the wing. The reflection of each tiny light can be measured in parallel with every other point in the field to quickly create a detailed, three-dimensional map of the wing’s structures.

“A speckled field is like thousands of fireflies that generate a field of illumination points,” So says. “Using this method, we can isolate the light coming from different layers, and can reconstruct the information to map efficiently a structure in 3D.”

Making connections

In their visualizations of the growing butterfly wing, the team watched the formation of highly detailed features, from micrometer-sized scales to even finer, nanometer-high ridges on individual scales.

They observed that, within days, cells quickly lined up in rows, and soon after differentiated in an alternating pattern of cover scales (those overlying the wing) and ground scales (those tucked underneath). As they reached their final size, each scale grew long, thin ridges resembling tiny corrugated roofing.

“A lot of these stages were understood and seen before, but now we can stitch them all together and watch continuously what’s happening, which gives us more information on the detail of how scales form,” McDougal says.

Interestingly, the team found that ridges on scales formed in an unexpected way. Scientists had assumed these grooves were a consequence of compression: As scales grow, they were thought to squeeze in like an accordion. But the team’s visualizations showed that instead of shrinking as any material would when compressed, the scales continued to grow in size as ridges appeared on their surface. These measurements suggest another ridge-forming mechanism must be at work. The group hopes to explore this, and other processes in the developing butterfly wing, which can help to inform the design of new functional materials.

“This paper focuses on what’s on the surface of the butterfly wing,” McDougal notes. “But underneath the surface, we can also see cells putting down roots like carrots, and sending out connections to other roots. There’s communication underneath the surface as cells organize. And on the surface, scales are forming, along with features on the scales themselves. We can visualize all of it, which is really beautiful to see.”

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

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