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MIT biologists have discovered the answer to a fundamental biological question: Why are cells of a given type all the same size?
In humans, cell size can vary more than 100-fold, ranging from tiny red blood cells to large neurons. However, within each cell type, there is very little deviation from a standard size. In studies of yeast, MIT researchers grew cells to 10 times their normal size and found that their DNA could not keep up with the demands of producing enough protein to maintain normal cell functions.
Furthermore, the researchers found that this protein shortage leads the cells into a nondividing state known as senescence, suggesting a possible explanation for how cells become senescent as they age.
“There are so many hypotheses out there that try to explain why senescence happens, and I think this data provides a beautiful and simple explanation for senescence,” says Angelika Amon, the Kathleen and Curtis Marble Professor in Cancer Research in the Department of Biology and a member of the Koch Institute for Integrative Cancer Research.
Amon is the senior author of the study, which appears in the Feb. 7 online edition of Cell. Gabriel Neurohr, an MIT postdoc, is the lead author of the paper.
To explore why cell size is so tightly controlled, the researchers prevented yeast cells from dividing by modifying a gene critical for cell division, so that it could be turned off at a certain temperature. These cells continued to grow, but they could not divide and they did not replicate their DNA.
The researchers discovered that as the cells expanded, their DNA and their protein-building machinery could not keep pace with the needs of such a large cell. This failure to produce enough protein led to the dilution of the cytoplasm and disruption of cell division. The researchers believe that many other fundamental cell processes that rely on cellular molecules finding and interacting with each other may also be impaired when cells are too big.
“Theoretical models predict that diluting the cytoplasm will decrease reaction rates. Every chemical reaction would occur more slowly, and some threshold concentrations of certain proteins may not be reached, so certain reactions would never happen because the concentrations are lower,” Neurohr says.
The researchers showed that yeast cells with two sets of chromosomes were able to grow to twice the size of yeast cells with just one set of chromosomes before becoming senescent, suggesting that the amount of DNA in the cells is the limiting factor in the cells’ ability to grow.
Experiments with human cells yielded similar results: In a study of human fibroblast cells, the researchers found that forcing the cells to grow to excessive sizes (eight times their normal size) disrupted many functions, including cell division.
“It’s been clear for some time that cells do control their size, but it’s been unclear what the various physiological reasons are for why they do so,” says Jan Skotheim, an associate professor of biology at Stanford University, who was not involved in the research. “What’s nice about this work is it really shows how things go wrong when cells get too big.”
Amon says excessive growth likely plays a major role in the development of senescence, which occurs in many types of mammalian cells and is thought to contribute to age-related organ dysfunction and chronic age-related diseases.
Senescent cells are often larger than younger cells, and this study, which showed that unchecked cell growth leads to senescence, offers a possible explanation for this observation. Human cells tend to grow slightly larger throughout their lifetimes, because every time a cell divides, it checks for DNA damage, and if any is found, division is halted while repairs are made. During each of these delays, the cell grows slightly larger.
“Over the lifetime of a cell, the more divisions you make, the higher your probability is of having that damage, and over time cells will get larger,” Amon says. “Eventually they get so large that they start diluting critical factors that are important for proliferation.”
A difficult question that remains unanswered is how different types of cells maintain the appropriate size for their cell type, which the researchers now hope to study further.
The research was funded, in part, by the National Institutes of Health, the Howard Hughes Medical Institute, the Paul F. Glenn Center for Biology of Aging Research at MIT, a National Science Foundation graduate research fellowship, the William Bowes Fellows program, and the Vilcek Foundation.
By his own admission, Héctor Javier Vázquez Martínez was underprepared to move to Zurich for a semester during his junior year. His cell phone plan didn’t work, he’d forgotten to change his money, and he didn’t know German. However, it didn’t take him long to find his way. Soon, the electrical engineering and computer science major was working in a lab at the University of Zurich and ETH Zurich’s Institute of Neuroinformatics, developing a computer model of how mice learn.
In his native Puerto Rico, Vázquez Martínez says, Switzerland was viewed as a sort of near-perfect country, which he only dreamed of visiting. Two previous summer internships had also left him feeling uncertain about what he wanted to do with his future. When he received an email about a departmental exchange between MIT and ETH Zurich, he knew it was an opportunity he couldn’t pass up.
Through the kindness of strangers who soon became friends, it all worked out for Vázquez Martínez. A member of the rowing club he joined helped him to learn German as he helped her refine her Spanish. When he began his research position, he would commute to work with a labmate. The research project turned out to be a great fit for Vázquez Martínez, whose initial interest in machine learning had led to a passionate curiosity about how humans think.
“The time that followed more than made up for the first rough couple of weeks. I would do it all over again if I had the chance,” he says.
Spending a semester in Switzerland is just one of many opportunities at MIT that the adventurous senior has seized. During his four years as an MIT student, he has taught underprivileged students abroad, joined the crew team and the Cuban salsa group Casino Rueda, and even dipped into the world of music theory.
During his first year, Vázquez Martínez spent three weeks in Chile as part of the MISTI Global Teaching Labs program. The plan had been to teach physics to kids from two middle- and low-income high schools during their summer break. But students from those schools generally enter the work force right after graduation. When he got there, Vázquez Martínez realized something more practical would be a better fit.
“My one and only reaction was, well … what good am I going to do you if I’m just teaching you physics?” he recalls. “This is just not going to help you when you graduate.”
A professor told Vázquez Martínez that the students could already wire and solder little electronic devices called Arduinos, but they didn’t know how to program them. Over the next few weeks, Vázquez Martínez improvised a curriculum for the high schoolers, teaching them how to program the devices on their own.
Then, in the summer following his first year, he participated in a program called Facebook University sponsored by the social media giant. He was given five weeks to develop an IOS app, which he said was generally expected to be a social networking app.
“I thought, well, the market is full of those. I want to do something that actually helps people,” he says.
Instead, Vázquez Martínez worked on an app that could translate the American Sign Language alphabet into text. While his team was only able to get the app working for four or so letters in that time period, they were able to present a fully functional proof of concept.
Thinking on the brain
His work with Facebook University sparked an interest in Vázquez Martínez for the field of machine learning. So, in his sophomore year, he took a class on artificial intelligence. To his surprise, he found that machine learning itself didn’t fascinate him.
“It’s mostly fancy statistics,” he says. “As I was taking the course, I found that I was a lot more interested in figuring out, why does this work? Why do we think this way? And why can I recognize a dog by just seeing a dog, as opposed to giving a computer 10,000 pictures of a dog and then maybe it’ll say it’s a dog and not a cat?”
Vázquez Martínez also became involved that year with neural network research by Glen Urban, the David Austin Professor in Marketing, Emeritus, in the Sloan School of Management. Basically, a computer would be fed thousands of descriptions of customers and lists of credit cards they applied for, and the program would predict which credit cards people with certain demographics would apply for. Vázquez Martínez took over the work from a student who graduated, and enjoyed having his own project. But come fall of his junior year, he decided it was time for a change of scenery, and he was off to Switzerland.
His research at the Institute of Neuroinformatics in Switzerland was related to a previous experiment, in which mice were taught to recognize different sandpaper surfaces using a system of positive and negative rewards. The way mice identify their surroundings is through neurons in their whiskers that relay information to their brains. Vázquez Martínez was assigned to make a computational model of three clusters of neurons in a mouse’s brain, and to teach the model to distinguish between different types of sandpaper the way mice do.
An active life
Vázquez Martínez has taken up music as a hobby, and recently completed 21M.051 (Fundamentals of Music). In the class, he learned introductory music theory through playing the piano. While he says he’s still at a pretty basic level of knowledge, it helps him to communicate with his younger brother who has been studying music from a very early age. They exchange pieces of theory that they’ve learned, show off songs they’ve picked up, and have even tried to compose a piano piece together.
Vázquez Martínez is also a member of the dance group Casino Rueda and averages about six to seven hours of dancing a week.
He started with the group as a beginner four years ago, and now leads some of the advanced sessions. Through dedicated practice, he says, “I found a love for the dance, the music, and how it allows me to communicate with other people. I am continually challenged by our practices and the other dancers, and feel a new rush of adrenaline with every choreography and performance.”
Vázquez Martínez also rows for lightweight men’s crew team. “I walked onto the crew team my first year having never seen a rowing oar in my life,” he says. “For me, it was an enormous step up in terms of dedication to a sport, but I stuck to it because I felt constantly forced to push the limits of what I thought I could physically and mentally do. In the words of my current team captain: ‘It is the purest form of teamwork.’”
As for Vázquez Martínez’s future, he’s still deciding on the specifics. After his time in Chile, he’s interested in teaching at home at Puerto Rico. And of course, he’s still captivated by his search to understand how people think. He’s not sure exactly what his next project will look like — but he says he’ll know it’s a good match when he wakes up thinking about his work.
Green plants capture light that spans the visible solar spectrum, and while a broad spectral range is required for sufficient absorption, the process requires energy to be funneled rapidly and efficiently downhill to drive charge separation and water splitting. Carotenoids, the accessory pigments in photosynthesis, play light harvesting, photoprotective, and structural roles.
Understanding these roles, however, has proved to be a challenge due to the fact that carotenoid's energetics are highly sensitive to their environment.
Now a team led by Thomas D. and Virginia W. Cabot Career Development Assistant Professor Gabriela Schlau-Cohen has discovered that a single carotenoid — LHCII — in the major antenna complex of green plants serves as the nexus of light harvesting by accumulating energy and transferring it through a debated dark state. These photophysics reveal how plants expand their capacity to capture and utilize solar energy.
“Solar energy devices must absorb a large fraction of the solar spectrum — i.e., many different energies or colors — to be competitive with fossil fuels,” says Minjung Son, a graduate student in Schlau-Cohen’s lab and one of the authors of a paper on the research. “Absorption of these energies comes with a challenge: How can the high energy be funneled down to the low energy, which is what is used to produce electricity and eventually biomass?”
To seek out their answer, the group ultimately built a blueprint.
“We mapped out pathways of energy flow that connect the high energy side to the low energy side of the absorbed solar spectrum, including one pathway through a previously-debated dark state,” Son explains. “This map provided a blueprint for solar energy devices that absorb a lot of energy across a broad range, as well as provides an important step in understanding the intricate photosynthetic machinery of plants.”
The research is described in “The Electronic Structure of Lutein 2 Is Optimized for Light Harvesting in Plants,” which is featured on the cover of the March 2019 issue of the journal Chem, which was released online on Jan. 31.
Eugene Fitzgerald appointed CEO and director of the Singapore-MIT Alliance for Research and Technology
Eugene A. Fitzgerald, the Merton C. Flemings-Singapore MIT Alliance Professor of Materials Engineering at MIT, has been appointed chief executive officer and director of the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore established in partnership with the National Research Foundation of Singapore. He is also the lead principal investigator of the SMART Low Energy Electronic Systems Interdisciplinary Research Group. He replaces Daniel Hastings, the Cecil and Ida Green Education Professor, who returns to MIT to head the Department of Aeronautics and Astronautics. Hastings served as SMART CEO and director from 2014 to 2018.
Fitzgerald has a distinguished career as an academic, researcher, and serial entrepreneur and has a keen awareness on innovation. He started his career as a research scientist in AT&T Bell Labs in 1989 upon attaining his PhD in materials science and engineering from Cornell University and a BS degree in materials science and engineering from MIT. Leveraging his experience at AT&T Bell Labs, he and colleagues invented high mobility strained silicon and commercialized the technology through AmberWave System Corporation — a company he co-founded in 1998 with his former MIT graduate student Mayank Bulsara. The majority of silicon integrated circuits in cell phones, computers, and other applications use the technology today.
Since 2004, he also founded or co-founded six other enterprises in the areas of semiconductors, water purification, and silicon-based high efficiency multi-junction solar cells.
Fitzgerald is the co-author of the book “Inside Real Innovation,” which promotes innovation as an iterative process where one goes through several cycles in the areas of technology, market, and implementation. In 2008 he co-founded a not-for-profit entity that formed joint corporate-university innovation teams to help corporations find new directions as well as educate participants through early-stage real-world project exploration.
“Professor Fitzgerald is an experienced academic leader and an accomplished innovator and entrepreneur. He is well-regarded in both the research and enterprise spheres in Singapore. I am confident that he will carry on the excellent leadership and propel SMART into the next phase of growth,” says MIT Provost Martin Schmidt.
SMART unites faculty, researchers, and graduate students from MIT and Singapore with academic and industry researchers in Singapore and Asia to collaborate in new areas of science and technology, and propel innovations into the enterprise space.
Fitzgerald says: “Having been involved with MIT programs in Singapore from the start in 1998, I have seen MIT and Singapore evolve together through collaboration in research, innovation, and enterprise, and look forward to building more capabilities and success in all areas.”
SMART comprises five large-scale research programs plus the Innovation Center. These programs are: Antimicrobial Resistance, BioSystems and Micromechanics, Disruptive and Sustainable Technologies for Agricultural Precision, Future Urban Mobility, and Low Energy Electronic Systems.
The following email was sent today to the MIT community by President L. Rafael Reif.
To the members of the MIT community,
Last October, following the assassination of journalist Jamal Khashoggi, I asked Associate Provost Richard Lester, who oversees MIT’s international activities, to reassess MIT engagements with Saudi entities. On December 6, Richard shared his preliminary report and recommendations with faculty, students and staff, and he asked for comments. Last week, Richard sent me a letter that summarizes and reflects on the community comments, adds several recommendations and offers some new information, including funding amounts from Saudi state sources.
You may read what Richard sent me here, including both his recent summary letter and his report from December. Together these constitute the Lester report.
I write now to share my view of how MIT should proceed in this complex situation.
The Lester report
The Lester report defines the three types of engagements that people from MIT have with entities in Saudi Arabia: sponsored research backed primarily by entities affiliated with the Saudi government; research and education programs funded by gifts, mostly from private Saudi foundations; and a few smaller connections, including executive education and Industrial Liaison Program memberships.
The report explores the full range of competing factors to consider, including faculty autonomy, the social and scientific value of the work we undertake with Saudi people and entities, the challenge of working in a nation so out of step with our commitment to inclusion and free expression, and our community’s deep sense of revulsion at actions of the Saudi regime.
Ultimately, the report concludes that if MIT faculty wish to continue their current engagements with colleagues, students, and public and private research sponsors in Saudi Arabia, they should be free to do so, as long as these projects remain consistent with MIT policies and procedures and US laws and regulations. It also proposes that if faculty members wish to disengage from Saudi projects in light of recent events, we should help them, including smoothing the transition for the teams involved. And it recommends ways to make sure that international projects with countries whose governments engage in troubling behaviors go through a specified review process before they are allowed to proceed or be renewed.
I offer some background to explain why I agree with these recommendations.
Some background on MIT’s Saudi relationships
I know many of you find the behavior of the Saudi regime so horrifying that you believe MIT should immediately sever all ties with any Saudi government entities. I share the sense of horror, and I have great respect for that point of view.
However, my experience leads me to see our Saudi engagements differently, and therefore to believe that cutting off these longstanding faculty-led relationships abruptly in midstream is not the best course of action.
For decades, MIT has strongly favored a strategy of engaging with the world and of opening the door to collaboration where our faculty see a significant opportunity to do constructive work. In this spirit, in 2007, when I was provost, faculty in Mechanical Engineering sought to begin working with King Fahd University of Petroleum & Minerals (KFUPM) on solar energy, seawater desalination and design education.
Because MIT had no formal mechanism for reviewing international engagements, I established the International Advisory Committee (IAC). The IAC co-chairs guided a review of the proposed KFUPM engagement, which included a representative, independent faculty group making a site visit to assess various concerns. The resulting report allowed the project to proceed, and in 2008 the Center for Clean Water and Clean Energy at MIT and KFUPM was launched. Because KFUPM is all male, a condition of the engagement was that the organizers create a path to scientific education for Saudi women; this inspired the Ibn Khaldun Fellowship that brings Saudi women PhDs to MIT.
Since that initial engagement, I have come to know many Saudi citizens, including MIT alumni, Saudi officials and industry leaders working to modernize Saudi society. I have also met Saudi students and postdocs, both women and men, who dream of helping their society participate in and contribute to the global scientific community. Through these contacts, I have been struck by the intensity of their commitment and the value of their efforts to use research and education to make progress for themselves and their society. And of course, knowing these individuals, it is impossible not to see them as separate from the regime they did not choose and cannot control.
Saudi Arabia faces an unusual demographic moment: More than half of Saudi citizens are younger than 30. In such a society, building knowledge and helping more people gain access to higher education constitute the surest path to social progress. This is why I have felt confident that allowing interested faculty to continue to engage constructively with Saudi students, postdocs, alumni, colleagues and sponsors whom they trust and respect is consistent with our mission to advance knowledge and educate students for the betterment of humankind.
How should we move forward?
The present moment is testing that position. When I agreed to host the Saudi state delegation at MIT last spring, I shared the hope of many in the US and around the world that the visit and official engagement were an important part of an ongoing process of reform and modernization. I know some of you were and remain disappointed by that decision, and I understand that disappointment.
As many of you have made plain, in the present situation, if MIT simply continues to work with Saudi state entities without comment, we risk having our silence taken as an endorsement of the regime’s behavior – an unacceptable result.
For the record then, let me be clear: MIT utterly condemns such brutal human rights violations, discrimination and suppression of dissent, including the murder of Jamal Khashoggi.
Nevertheless, I hope we can respond to present circumstances in a way that does not suddenly reject, abandon or isolate worthy Saudi people who share our principles and are doing good work for themselves, their society and the world, particularly if MIT faculty wish to continue the engagement.
The way forward will include carefully and thoroughly reassessing these engagements if faculty seek to renew them. This practice will of course apply to proposed new international engagements as well. To do this well, we need to reexamine aspects of our assessment process and find ways to improve them.
Strengthening our system of assessment
Indeed, many of you have suggested to both Richard and me that MIT develop stronger processes to assess our international engagements in general.
As Richard describes in his summary, we have a head start on this. With just this goal – and considering engagements in a range of nations beyond Saudi Arabia – we have been working over the last 18 months to revamp our existing procedures and groups, including reconstituting the IAC as a faculty-led, standing committee of the Institute.
Already, the IAC is better equipped to vet potential new international engagements and those up for renewal, including those with foreign state entities; to assess whether, weighing all the relevant factors, a given engagement is advancing MIT's core academic mission; and to advise on the right course of action. At the same time, we are developing new administrative practices for assessing the complex risks that international projects may pose. We will systematically coordinate these two approaches, to make sure that MIT’s international engagements receive a thorough review.
Many of you also observed that we have an opportunity now to consider further questions about how we might approach international engagements in problematic countries. How could we include a broader range of community voices? What’s the best way to tap our faculty expertise in fields like history, political science, anthropology, philosophy and more? Can we offer our campus community new ways to gain a fuller understanding of the countries we engage in? Is there a general standard that could be applied in such cases? Are there further steps we can take to make sure that our engagements are not only in tune with but advance MIT’s values, including equality and free expression?
The faculty officers – Chair Susan Silbey, Associate Chair Rick Danheiser and Secretary Craig Carter – have agreed, at my request, to create an ad hoc interdisciplinary committee of faculty, staff and students to consider such questions. The committee will report to the MIT administration by this coming September. They will offer guidelines for action as well as expertise to call on when MIT assesses new international engagements.
I am deeply grateful to Susan, Rick and Craig for taking on this important assignment; I believe the work of the ad hoc committee will be of great value in MIT’s development as a globally engaged university.
* * *
I close by thanking Richard for his tremendous care and effort in leading this reassessment, and by thanking everyone in the community who has taken the time to contribute their perspectives on this sensitive and complex topic. One can only be grateful to belong to a society that guarantees each of us the right to openly express our opinions, and to a community that takes so seriously its obligation to wrestle honestly with its most difficult challenges. We all become smarter and wiser by thoughtfully engaging one another and taking advantage of such a precious right.
L. Rafael Reif
Inside a large classroom of the MIT Sloan School of Management, a group of CEOs, corporate venturing executives, entrepreneurs, and members of regional economic development organizations is passing around brightly colored bibs that double as chew toys for teething babies. They’ve just been told the products are twice as expensive as several knockoffs, and yet the two Scottish moms who run the company have sold more than a million of them in recent years.
“What is this company’s core advantage in the market?” Bill Aulet, the managing director of the Martin Trust Center for MIT Entrepreneurship, asks his befuddled and slightly amused audience.
As the crowd throws out ideas based on their careful analysis of the bib — everything from unique designs of cartoon animals to safety features — Aulet steers them toward the point of the exercise: Always focus on the customer. In this case, the founders have established a following among upper middle-class moms who want their babies not only clean and happy but stylish; brand recognition goes a long way for this particular demographic.
Focusing on the customer is a simple enough concept to understand, but it requires a total and unwavering commitment when starting a company.
The lesson was one of many last week that challenged attendees to think like succesful entrepreneurs during the 20th annual Entrepreneurship Development Program. The program, known as EDP, stands out among Sloan’s executive education offerings for its action-based learning and breakneck pace.
In one whirlwind week, the course teaches attendees about each step of the venture creation process and challenges them to apply those lessons as teams in a company-building project. The experience is as demanding as it is rewarding.
“I feel like I’ve been here for a year already,” exclaimed one of this year’s attendees in the middle of the second day.
Each day includes lectures by senior MIT faculty members and succesful entrepreneurs, deep dives into case studies, and visits to local startups. As the evening approaches, attendees work to achieve project milestones, picking up additional lessons — including the importance of team dynamics and how to work in high-stress environments — along the way.
“It’s one thing to sit there and be told in a classroom, ‘This is how something should work,’ but actually executing is very difficult,” says Riley Rees, who attended EDP in 2017 and is currently an MBA candidate at Sloan. “EDP is action-based learning. The structure is so rigorous; it’s an incredible experience.”
Since it’s inception in 1999, the course has allowed thousands of participants from more than 75 countries to “drink from the MIT firehose,” as Aulet affectionately puts it. The goal is to maximize MIT’s impact by exporting its unique brand of high-tech entrepreneurship to people from around the world.
“Innovation-driven entrepreneurship is what people want more and more, and if you want to get it like a shot in the arm, as quickly as you can, EDP is the best choice,” says Aulet, who serves as the faculty director of EDP.
The demanding schedule makes for a charged classroom that Aulet says mimics the startup experience and maximizes EDP’s benefits.
“People involved with [EDP] have a blast,” Aulet says. “The energy in the room pushes everyone. You have an energized classroom, it energizes the instructors, and it’s a positive feedback loop that takes you to another level. It’s really transformative.”
A history of impact
Aulet credits Ed Roberts, the David Sarnoff Professor of Management and Technology at Sloan, with starting programs on running high-tech businesses at MIT in the 1980s and ’90s. In 1990, Roberts founded the MIT Entrepreneurship Center, later renamed the Martin Trust Center for MIT Entrepreneurship, where MIT has organized many of its entrepreneurial training resources.
Ken Morse served as the founding managing director of the center between 1996 and 2009 at a time when the number of MIT professors teaching entrepreneurship-related courses grew from three to over 36. Aulet says Morse helped take EDP “from academic speed to entrepreneur speed.”
The program’s effect on attendees can be measured in applications that come in the following year. Customers, the entrepreneurial saying goes, vote with their feet. In that sense, EDP has been a huge success, consistently attracting a large amount of interest each year while largely relying on word of mouth for marketing.
“I think EDP markets itself,” Aulet says. “Throughout the world, there are thousands of alumni of EDP, and they’re our best sales people. The best sales person you can have is your customer.”
The program’s impact extends even beyond its thousands of past attendees, as many EDP alumni use the framework they learned to improve the entrepreneurial ecosystems in their own regions.
“There’s been a proliferation of similar programs that in many cases have been inspired by [EDP],” says Peter Hirst, Sloan’s senior associate dean for executive education. “We know this because people have attended EDP and told us they were attending to replicate this type of capability-building at their own institutions.”
From that perspectve, EDP serves as a gateway for complementary initiatives such as the MIT Regional Entrepreneurship Acceleration Program (REAP), a two-year learning engagement between the Institute and regions around the world that began in 2012, and MIT Bootcamps, which bring together groups from around the world for a similar project-based program.
Scotland, for instance, was part of the first cohort of MIT REAP and has been sending entrepreneurs to EDP for years.
“The goal of REAP is to create entrepreneurial ecosystems, and the single necessary condition to have a sufficient entrepreneurial ecosystem is an entrepreneur,” Aulet says. “We help produce entrepreneurs. Once you’ve got entrepreneurs, you can look at government policy, capital, etc. So the relationship [between REAP and EDP] is synergistic.”
John Knapton, who works at the nonprofit accelerator Catalyst in Northern Ireland, brought 10 CEOs from his region to EDP this year to expose them to MIT’s methods in hopes of improving Northern Ireland’s culture of entrepreneurship.
“We’re really keen to encourage academic-industrial entrepreneurship,” Knapton says of his organization. “At MIT, here’s a successful university that does spinoffs really, really well. So how can we duplicate that back home?”
Still going strong
The business world has experienced booms, busts, and major transformations since 1999, and EDP’s curriculum has adjusted accordingly. This year’s program emphasized the importance of collecting data to build and protect unique value propositions.
“Each year, we look at the program and update it for the new needs and opportunities of the market,” Aulet says.
And EDP’s instructors wouldn’t be practicing what they preach if they weren’t constantly seeking feedback from attendees and iterating on the course design.
“We get enough feedback to know if we’re resonating with them, and we learn from them,” Aulet says. “That’s entrepreneurial behavior in action. We have to walk the walk.”
Twenty years is an old age for any program, but the people running EDP show no signs of slowing down.
“The program itself evolves a lot; it’s a living organism,” Hirst says. “On one hand, I feel 20 years is a good lifetime for a program, but I see no reason why there wouldn’t continue to be a need for it for another 20 years and beyond. It’s every bit as vibrant and useful now as it was 20 years ago.”
New work from MIT researchers peers under the hood of an automated fake-news detection system, revealing how machine-learning models catch subtle but consistent differences in the language of factual and false stories. The research also underscores how fake-news detectors should undergo more rigorous testing to be effective for real-world applications.
Popularized as a concept in the United States during the 2016 presidential election, fake news is a form of propaganda created to mislead readers, in order to generate views on websites or steer public opinion.
Almost as quickly as the issue became mainstream, researchers began developing automated fake news detectors — so-called neural networks that “learn” from scores of data to recognize linguistic cues indicative of false articles. Given new articles to assess, these networks can, with fairly high accuracy, separate fact from fiction, in controlled settings.
One issue, however, is the “black box” problem — meaning there’s no telling what linguistic patterns the networks analyze during training. They’re also trained and tested on the same topics, which may limit their potential to generalize to new topics, a necessity for analyzing news across the internet.
In a paper presented at the Conference and Workshop on Neural Information Processing Systems, the researchers tackle both of those issues. They developed a deep-learning model that learns to detect language patterns of fake and real news. Part of their work “cracks open” the black box to find the words and phrases the model captures to make its predictions.
Additionally, they tested their model on a novel topic it didn’t see in training. This approach classifies individual articles based solely on language patterns, which more closely represents a real-world application for news readers. Traditional fake news detectors classify articles based on text combined with source information, such as a Wikipedia page or website.
“In our case, we wanted to understand what was the decision-process of the classifier based only on language, as this can provide insights on what is the language of fake news,” says co-author Xavier Boix, a postdoc in the lab of Eugene McDermott Professor Tomaso Poggio at the Center for Brains, Minds, and Machines (CBMM) in the Department of Brain and Cognitive Sciences (BCS).
“A key issue with machine learning and artificial intelligence is that you get an answer and don’t know why you got that answer,” says graduate student and first author Nicole O’Brien ’17. “Showing these inner workings takes a first step toward understanding the reliability of deep-learning fake-news detectors.”
The model identifies sets of words that tend to appear more frequently in either real or fake news — some perhaps obvious, others much less so. The findings, the researchers say, points to subtle yet consistent differences in fake news — which favors exaggerations and superlatives — and real news, which leans more toward conservative word choices.
“Fake news is a threat for democracy,” Boix says. “In our lab, our objective isn’t just to push science forward, but also to use technologies to help society. … It would be powerful to have tools for users or companies that could provide an assessment of whether news is fake or not.”
The paper’s other co-authors are Sophia Latessa, an undergraduate student in CBMM; and Georgios Evangelopoulos, a researcher in CBMM, the McGovern Institute of Brain Research, and the Laboratory for Computational and Statistical Learning.
The researchers’ model is a convolutional neural network that trains on a dataset of fake news and real news. For training and testing, the researchers used a popular fake news research dataset, called Kaggle, which contains around 12,000 fake news sample articles from 244 different websites. They also compiled a dataset of real news samples, using more than 2,000 from the New York Times and more than 9,000 from The Guardian.
In training, the model captures the language of an article as “word embeddings,” where words are represented as vectors — basically, arrays of numbers — with words of similar semantic meanings clustered closer together. In doing so, it captures triplets of words as patterns that provide some context — such as, say, a negative comment about a political party. Given a new article, the model scans the text for similar patterns and sends them over a series of layers. A final output layer determines the probability of each pattern: real or fake.
The researchers first trained and tested the model in the traditional way, using the same topics. But they thought this might create an inherent bias in the model, since certain topics are more often the subject of fake or real news. For example, fake news stories are generally more likely to include the words “Trump” and “Clinton.”
“But that’s not what we wanted,” O’Brien says. “That just shows topics that are strongly weighting in fake and real news. … We wanted to find the actual patterns in language that are indicative of those.”
Next, the researchers trained the model on all topics without any mention of the word “Trump,” and tested the model only on samples that had been set aside from the training data and that did contain the word “Trump.” While the traditional approach reached 93-percent accuracy, the second approach reached 87-percent accuracy. This accuracy gap, the researchers say, highlights the importance of using topics held out from the training process, to ensure the model can generalize what it has learned to new topics.
More research needed
To open the black box, the researchers then retraced their steps. Each time the model makes a prediction about a word triplet, a certain part of the model activates, depending on if the triplet is more likely from a real or fake news story. The researchers designed a method to retrace each prediction back to its designated part and then find the exact words that made it activate.
More research is needed to determine how useful this information is to readers, Boix says. In the future, the model could potentially be combined with, say, automated fact-checkers and other tools to give readers an edge in combating misinformation. After some refining, the model could also be the basis of a browser extension or app that alerts readers to potential fake news language.
“If I just give you an article, and highlight those patterns in the article as you’re reading, you could assess if the article is more or less fake,” he says. “It would be kind of like a warning to say, ‘Hey, maybe there is something strange here.’”
Since the Cambridge City Council approved MIT’s rezoning petition for the 14-acre U.S. Department of Transportation (DOT) Volpe site in October 2017, a team of architects and landscape planners has been working to imagine a new home for the John A. Volpe National Transportation Systems Center in Kendall Square.
As part of its January 2017 agreement with the federal government, MIT will build a new headquarters for the U.S. DOT Volpe Center on approximately four acres. The building site is located in the northwest corner of the parcel, next to Binney Street and Loughrey Walkway, which runs between Broadway and Binney Street. The new facility will consolidate operations that are currently carried out in six different buildings on the site.
The federal government, working through the General Services Administration (GSA), and MIT engaged architectural firm Skidmore, Owings and Merrill to design the new building, which is slated to meet the Leadership in Energy and Environmental Design (LEED) Gold level. The design includes robust sustainability and resiliency features, including solar panels on the roof that will supply at least 30 percent of the building’s hot water demand, and high-efficiency heating, ventilation, and cooling equipment. The team designed the building’s massing, glazing, and interior layouts to maximize daylight into the building, and designed fins on the exterior façades to minimize heating and cooling loads. In addition, the site will incorporate best practices in storm water management.
Although the project is not subject to local review, the design of the new 212-foot-tall center was subject to the federal government’s rigorous review process as part of the GSA Design Excellence Program. This process also considered design guidelines recommended by the City of Cambridge, included peer reviews, and ultimately was approved by the GSA’s regional chief architect and the chief architect of the U.S.
MIT Managing Director of Real Estate Steve Marsh says: “This is a very complex project that is being executed on behalf of the United States government. The collaboration with the federal government has gone very well, and we are pleased with the outcome of the building and landscape design processes. I believe that the new U.S. DOT Volpe Center will be a welcome and vibrant addition to the broader Kendall Square community.”
Inviting and engaging public spaces, including seating areas and walkways, will surround the federal headquarters. A primary goal of the public space is to bring the East Cambridge neighborhood and Kendall Square community together through a new north-south connection. The development of this currently inaccessible site, which comprises predominantly asphalt surface parking, will promote access to and from the residential neighborhood, the Charles River, the MBTA, and the many retail and restaurant offerings in Kendall Square.
In order to achieve this sense of openness and connectivity, the GSA and MIT engaged artist Maya Lin, known for her large-scale, site-specific outdoor earthworks, in coordination with landscape architecture firm Reed Hilderbrand, to create an engaging and inviting public landscape. Central to the open space will be Lin’s landscape-integrated art piece — a physical and visual representation of the Doppler effect, manifested in undulating grassy mounds that depict sound waves.
The incorporation of a Maya Lin art piece within the site is part of the Federal government’s Art in Architecture program which commissions artworks for new buildings nationwide.
Since the outset of the project, the GSA has been focused on constructing a headquarters that is inviting and reflects the context of the site’s surroundings. GSA Regional Commissioner of the Public Buildings Service Glenn Rotondo says: “We are committed to creating a public realm that is well-integrated within the community.”
Once completed, the new U.S. DOT Volpe development will include primarily below-grade vehicular parking and ample bicycle parking. In addition, over 100 new diverse native-species trees will be installed using current best practices in planting, and an extensive landscaping program will be available for the public to enjoy. Even though the federal government is exempt from Cambridge’s local tree ordinance, the tree replacement plan is designed to materially exceed the current local requirements for large projects. To prepare the site for construction, 21 private trees will be removed that are within the building’s footprint or security perimeter. Twenty of those trees are Norway Maples, an invasive species that Massachusetts prohibits from being sold, planted, or propagated. In addition, two street trees will need to be relocated or replaced to accommodate a curb cut required by the project.
Enabling utility work on the Federal site is ongoing, and construction of the garage and building is expected to start later this year and take approximately three years. Once the new John A. Volpe National Transportation Systems Center is up and running, the Institute will be able to commence redevelopment of the remaining 10 acres of the original U.S. DOT Volpe parcel. MIT’s proposal for that portion of the site, which was presented to the community during the rezoning process, features housing (including 280 affordable units), commercial and lab space, retail, open space, a community center, and a job connector.
MIT is currently advancing other commitments that were codified as part of the Volpe rezoning agreement. The Institute has already provided $500,000 toward the design of the Grand Junction multiuse community path, which will be followed by an additional $8 million contribution for continuing design and construction. MIT staff are currently working closely with the city and other stakeholders to implement this critical infrastructure project. In addition, the Institute is in the process of identifying a site for a new 500-bed graduate student residence hall — a commitment made to the City of Cambridge through the Volpe zoning process.
The U.S. DOT Volpe building and landscape design is being shared with the Cambridge Planning Board tonight at the board’s annual Town Gown public meeting.
The fall semester’s final meeting on Dec. 12 had something of a high-stakes feel ror members of class 22.033 (Nuclear Science and Engineering Design),
“We’re pretty nervous,” said Jared Wilson, a senior majoring in Course 22. With four classmates and a mockup of a fast fission nuclear reactor, Wilson was awaiting the start of their team's project presentation. The anxiety-inducing format consisted of a 10-minute pitch before a panel of expert judges; the lucky winners would earn a free trip to Singapore in January for an international hackathon.
The class, packaged as a semester-long design competition, requires students to identify a significant real-world challenge and demonstrate how it could be solved in a commercially viable way through the application of nuclear science and engineering. Guided by class instructor Zachary Hartwig, the John C. Hardwick Assistant Professor of Nuclear Science and Engineering, three teams assembled to tackle the formidable assignment.
“They interviewed people in academia and in industry to figure out what they should be working on, and how to leverage their skills to do great things,” Hartwig said. “That process of going out and finding problems may be one of the most important things we try to teach, because that’’s what you do in the real world.”
First up, before a standing-room-only audience in 32-144, was Radception — a team aiming to redefine the radiation detector. Employees in nuclear facilities or physicians working with radiological material face hazards on a daily basis, and the current approaches to dealing with the dangers don't cut it, members of the team said. Radception’s idea: a product that straps around the wrist, offering immediate feedback through vibration as well as real-time online monitoring. Powered by lithium ion battery, the pocket Geiger module senses gamma and beta radiation, and instantly alerts the user, with the degree of vibration corresponding to the magnitude of radiation present.
One judge bravely volunteered as a guinea pig.
“Will this hurt?” asked NSE department head Dennis Whyte, as a weak uranium source approached the detector on his wrist. “Wow, I felt immediate buzzing that excited the nerve in my arm.”
Radception “offers contemporary convenience, intuitive interaction, with the hope of reaching as many radiation workers as possible,” said team member and senior Kevin Tang.
Mujtaba Jebran, a junior majoring in mechanical engineering, said that, according to the team's research, if implemented correctly a detector could “reduce the possibility of cancer to radiation workers by about 23 percent, so there's a very big potential impact.”
The team is open to taking their project to the next level.
“If that opportunity arises, we're definitely interested,” said Tang. “During the course of the semester I became more and more attached to the project — it’s our little baby.”
It would not be the first time 22.033 generated a pathbreaking, if not market-worthy, idea. In 2016, a team under then-instructor Michael Short, an assistant professor of nuclear science and engineering, took on the problem of reducing carbon dioxide emissions. Their solution: irradiating plastic waste from bottles to reuse as a concrete additive.
In work the team published, they showed that gamma-irradiated plastic actually strengthened concrete, and as a fill, suggested a way of reducing global concrete production, which is responsible for an enormous volume of carbon dioxide emissions. This idea sparked interest among industrial concrete manufacturers.
While 22.033 encourages students to pursue pressing problems like climate change, it also leaves room for students to grapple with intriguing, emerging questions. The second team, Asteroid Atomics, represented by Jared Wilson and his classmates, developed a nuclear reactor tailored for unpiloted space missions.
With the strain on Earth’s resources from a growing population, a budding private space industry has begun investing millions of dollars to explore the possibility of asteroid mining, the team explained. What these firms most need to harvest such rare elements as platinum is a power system to provide long-term energy for a mining operation deep in the solar system.
“We see a hard engineering problem that cannot be solved by solar plus battery,” said team members. Their solution: a reactor system using uranium-based fuel, cutting edge carbon nanotube technology and linear-actuating Stirling heat engines. Two Asteroid Atomics power systems would fit into the payload of a SpaceX Falcon 9 rocket, and according to team estimates, could function for 12 years.
After running the numbers, the team projected a cost of $40 million for one of their power systems. Given the wealth of resources in space, this kind of number might prove attractive to aspiring asteroid miners. “We hope to bring ideas of the space industry from science fiction to reality, and serve as a stepping stone for getting mankind to the final frontier,” they concluded.
Given the speculative nature of the pitch, some of the judges prodded the team on specifics, from potential safety issues to the reliability of its electrical system. But others were happy to go along for the ride.
“I had no idea that asteroid mining was a thing,” said Sarah Haig Baker, COO and co-founder of Silverside Detectors, Inc., a start-up nuclear detection firm. “I enjoyed learned something new, and it was really interesting.”
The final team, and winner of the design competition, was Neudrop. Confronting the problem of global fresh water shortage, students sought a way to husband water resources more effectively. They decided to focus on water used in agricultural irrigation, which comprises approximately 70 percent of fresh water resources.
Neudrop’s answer was an inexpensive soil moisture detector that enables farmers to read water needs over a large area. Demonstrating their invention with a transparent acrylic box full of sand, their detector fits in a tube easily inserted into the ground at different depths. According to the team's description: “We use everyday neutrons from space slamming into a hot photodiode.” The neutrons interact with water in the soil, and then the battery-powered device generates electrical feedback that can be read as a kind of moisture profile.
The Neudrop team envisioned a competitively priced detector deployed in multiple sites across a farmer’s cropland, measuring available soil moisture on a daily basis. “We will enable farmers to increase their efficiency in irrigation scheduling, saving water and expenses,” their description stated.
“But it’s not only about helping farmers save money on water, it's about helping the planet and our society to save water in an environment of climate change,” said team mentor Areg Danagoulian, the Norman C. Rasmussen Assistant Professor of Nuclear Science and Engineering.
Serving as a sounding board for the team as it figured out both target problem and solution, Danagoulian found reason for cheer not just in the team’s success, but the larger experience of 22.033.
“It really stressed the students to think creatively about a big, relevant problem, and the class gave them the skills they needed to approach it,” he said. “And overall it was a good challenge to develop an actual vision about where they think we should be going, because it will help them in the future as they routinely face just these kinds of problems.”
A unique event took place yesterday at The Metropolitan Museum of Art in New York City. Museum curators, engineers, designers, and researchers gathered in The Met’s iconic Great Hall to explore and share new visions about how artificial intelligence (AI) might drive stronger connection between people and art. A highlight from Monday’s festivities was the “reveal” of a series of artificial intelligence prototypes and design concepts, developed in collaboration across three institutions: The Met, Microsoft, and MIT.
Birth of a collaboration
For MIT, the collaboration began when Loic Tallon, The Met’s chief digital officer, visited the MIT campus to deliver an MIT Open Learning xTalk on the role of open access in empowering audiences and learners to experience art worldwide. Tallon views the collaboration as part of The Met’s initiative to drive global access to the museum’s collection through digital media: “We’re continuing to think differently about how a museum works, in this case how we leverage powerful technologies such as artificial intelligence. This collaboration among The Met, with our collection expertise, MIT with all these creative technologists and their incredible thinking about meeting tough challenges, and Microsoft with its AI platform has incredible synergy.”
MIT Open Learning and the MIT Knowledge Futures Group, two Institute organizations focused on the power of open data to create new knowledge, thus began a collaboration with The Met and Microsoft to spark global connections to art through AI.
On Dec. 12 and 13, the three collaborators came together to develop scalable new ways to engage the world through art and artificial intelligence. Curators from The Met joined MIT students and researchers, as well as expert technologists from Microsoft for a hackathon at Microsoft’s New England Research and Development Center. The ongoing projects from the hackathon, which were “revealed” Monday night, are:
Artwork of the Day - Using Microsoft AI to analyze open data sets, including location, weather, news, and historical data, it finds and delivers artwork from The Met collection that will resonate with users.
Tag, That’s It - Using crowdsourcing to fine-tuning subject keyword results generated by an AI model by adding keywords from The Met’s archive into Wikidata and using Microsoft AI to generate more accurate keywords, Tag, That’s It enriches The Met collection with the global Wiki community.
Storyteller - Built with the help of MIT faculty participants Azra Akšamija and Lara Baladi, Storyteller uses Microsoft voice recognition AI to choose artworks in The Met collection that illustrate any story or any conversation.
My Life, My Met - Using Microsoft AI to analyze posts from Instagram, My Life, My Met substitutes one's images with the closest matching Open Access artworks from The Met collection, enabling individuals to bring art into their everyday interactions.
Gen Studio - Empowered by Microsoft AI, Gen Studio allows anyone to visually and creatively navigate the shared features and dimensions underlying The Met’s Open Access collection. Within the Gen Studio is a tapestry of experiences based on sophisticated generative adversarial networks (GANs) which invite users to explore, search, and be immersed within the latent space underlying The Met’s encyclopedic collection. It’s being built with the help of MIT visiting artist Matthew Ritchie, the Dasha Zhukova Distinguished Visiting Artist at the MIT Center for Art, Science and Technology, and Sarah Schwettmann of the MIT Knowledge Futures Group and graduate student in Brain and Cognitive Sciences.
The Met, as part of its Open Access program (which celebrated its second anniversary on Monday), has just released a newly developed “Subject Keywords” dataset of its collection. As Tallon explains, “We want to remove this idea that there’s only one way to engage with our collection. There are so many different ways of experiencing art, and many of those ways are being explored through the hackathon and beyond.”
Reasons to collaborate: synergies among art, AI, and developers
SJ Klein of MIT’s Knowledge Futures Group views the collaboration as building “a beautiful mosaic of a solution” that blends technology and people. “We're exploring how people can find new meaning and develop understanding of the world through large-scale collaborations with these increasingly iterative cycles of people and interpreting machines and networks all trying to make sense of the space,” he says.
For Ryan Gaspar, director of strategic partnerships at Microsoft’s Brand Studio, working with MIT and The Met means combining art, storytelling, and technology to create something unique. “The richness of the art and stories helps inform the technologists here from MIT and Microsoft. And then building on top of that our AI capabilities. We're already seeing some interesting concepts and ideas that neither MIT, Microsoft, nor The Met would have ever come up with on our own.”
A case study in AI for impact
Klein adds that the role of AI is to elevate the existing openness of The Met’s collection, promoting deeper audience engagement: “In terms of making the museum a platform for connection, open access alone isn’t enough. There's an entire discipline we're figuring out regarding what tools might support access and engagement. We’re building some of those tools now.”
Microsoft sees its role as empowering developers with AI tools and showing how AI can bring positive impact to the world. “We take a very optimistic view around how AI can actually drive empathy, foster connections and productivity, as well as support progress for society, humanity, and business. This collaboration is important for us to show the power and tangibility of what AI can do,” explains Gaspar.
The experience for the MIT community
The hackathon and its projects brought together students and faculty from across the Institute ranging from brain and cognitive sciences, the Media Lab, humanities, arts, and social sciences, engineering, computer science, and more. Such interdisciplinary exchange and hands-on collaboration, enabled by open access to data, knowledge, and tools, is at the root of MIT Open Learning’s approach to transforming teaching and learning.
For MIT students accustomed to tackling tough technical problems, the focus on problem-solving in the arts was a major plus. “It’s been fun working in the arts space, and thinking about cultural impact of the technology being built,” said MIT first-year undergraduate Isaac Lau. What MIT graduate student Sarah Schwettmann took away most was “the enjoyment of collaborating with The Met’s best curators and the top experts from Microsoft in finding innovative ways to engage people around art.”
Noelle LaCharite, who leads developer experience for cognitive services and AI at Microsoft, took the long-view about what MIT students learned: “These hackers are building important skills around identifying their own strengths and tapping into the strengths of others. They’re learning not to wait for permission, to take initiative, advocate for a vision, push it forward, and ask for help when needed. Those are classic life and work skills.”
Open development will continue on the tools built during the hackathon. As Sanjay Sarma, MIT vice president for open learning, explains: “MIT supports The Met’s commitment to open access, paired with the power of Microsoft AI, in order to empower people globally to create new knowledge and ways of experiencing art and culture that are so vital to our humanity.” Monday night’s event at The Met was a celebration of that openness and collaborative spirit.
Measuring the toxic effects of chemical compounds on different types of cells is critical for developing cancer drugs, which must be able to kill their target cells. Analyzing cell survival is also an important task in fields such as environmental regulation, to test industrial and agricultural chemicals for possible harmful effects on healthy cells.
MIT biological engineers have now devised a new toxicity test that can measure chemical effects on cell survival with much greater sensitivity than some of the most popular tests used today. It is also much faster than the gold-standard test, which is not widely used because it takes two to three weeks to yield results. The new test could thus help drug companies and academic researchers identify and evaluate new drugs more rapidly.
“Cytotoxicity assays are one of the most commonly used assays in life sciences,” says Bevin Engelward, a professor of biological engineering at MIT and the senior author of the study.
Le Ngo, a former MIT graduate student and postdoc, is the lead author of the paper, which appears in the Feb. 5 issue of Cell Reports. Other authors include Tze Khee Chan, a former graduate student at the Singapore-MIT Alliance for Research and Technology (SMART); Jing Ge, a former MIT graduate student; and Leona Samson, Ngo’s co-advisor and an MIT professor emerita of biological engineering.
The traditional test for measuring cell survival, known as the colony formation assay, involves growing cell colonies in tissue culture dishes for two to three weeks after exposing the cells to a chemical compound or another harmful agent such as radiation. A researcher then counts the number of colonies to determine how the treatment affected the cells’ survival.
Part of Engelward’s motivation for this study was the memory of the long hours she spent counting such colonies as a graduate student.
“The counting is really laborious and painfully difficult because you have to constantly make judgement calls as to what is a colony versus debris,” she says. “Few people use the colony formation assay anymore because it’s difficult, way too slow, and requires huge amounts of cell growth media, so you need a lot of the compound being tested.”
In recent years, scientists have begun using other methods that are faster but not as accurate and sensitive as the colony formation assay. These tests do not measure cell growth directly but instead analyze mitochondrial function.
Engelward and colleagues set out to develop a test that could generate results in just a few days while still matching the accuracy and sensitivity of the colony formation assay. The system they invented, which they call the MicroColonyChip, consists of tiny wells on a plate. Treated and untreated cells are placed into these wells and begin to form very small colonies in a grid pattern. Within just a few days, before the colonies become visible to the naked eye, the researchers can use a microscope to image the cells’ DNA, which is fluorescently labeled.
By modifying code originally developed by former MIT postdoc David Wood and MIT Professor Sangeeta Bhatia, the researchers created a software program that measures the amount of fluorescent DNA in each well and then calculates how much cell growth occurred. By comparing the growth of treated and untreated cells, the researchers can determine the toxicity of whatever compound they are studying.
“We have an automatic scanning system to do the fluorescent imaging, and afterward, the image analysis is completely automated,” Ngo says.
The researchers compared their new test to the gold-standard colony formation assay and found that the results were indistinguishable. They were also able to precisely reproduce data on the effects of gamma radiation on human lymphoblastoid cells, collected 20 years ago using the colony formation assay. Using the MicroColonyChip, the researchers obtained their data in three days, instead of three weeks.
“We were able reproduce radiation studies from 20 years ago, using a process much easier than what they did,” Engelward says.
The researchers also compared their new test to the two toxicity tests that are most commonly used by researchers and pharmaceutical companies, known as XTT and CellTiter-Glo (CTG). Both of these tests are indirect measures of cell viability: XTT measures cells’ ability to break down tetrazolium, a key step in cellular metabolism, and CTG measures intracellular levels of ATP, molecules that cells use to store energy.
“The MicroColonyChip is much more sensitive than the XTT assay, so it really gives you the ability to see subtle changes in cell survival, and it is as sensitive as the CTG assay while being more robust to artifacts,” Engelward says.
Using the new test, the researchers examined the effects of two DNA-damaging drugs used for chemotherapy and found that they could accurately reproduce the results obtained using the traditional colony formation assay. “We now plan to expand those studies in hopes of demonstrating that the test works for many more types of drugs and cells,” Ngo says.
In addition to being useful for drug development, this test could also be helpful for environmental regulatory agencies responsible for testing chemical compounds for potential harmful effects, Engelward says. Another possible application is in personalized medicine, where it could be used to test a variety of drugs on a patient’s cells before a treatment is chosen.
The researchers have filed for a patent on their technology. The research was funded by the National Institute of Environmental Health Sciences, including the NIEHS Superfund Basic Research Program, and the National Institutes of Health.
Hydrogen, the second-tiniest of all atoms, can penetrate right into the crystal structure of a solid metal.
That’s good news for efforts to store hydrogen fuel safely within the metal itself, but it’s bad news for structures such as the pressure vessels in nuclear plants, where hydrogen uptake eventually makes the vessel’s metal walls more brittle, which can lead to failure. But this embrittlement process is difficult to observe because hydrogen atoms diffuse very fast, even inside the solid metal.
Now, researchers at MIT have figured out a way around that problem, creating a new technique that allows the observation of a metal surface during hydrogen penetration. Their findings are described in a paper appearing today in the International Journal of Hydrogen Energy, by MIT postdoc Jinwoo Kim and Thomas B. King Assistant Professor of Metallurgy C. Cem Tasan.
“It's definitely a cool tool,” says Chris San Marchi, a distinguished member of the technical staff at Sandia National Laboratories, who was not involved in this work. “This new imaging platform has the potential to address some interesting questions about hydrogen transport and trapping in materials, and potentially about the role of crystallography and microstructural constituents on the embrittlement process.”
Hydrogen fuel is considered a potentially major tool for limiting global climate change because it is a high-energy fuel that could eventually be used in cars and planes. However, expensive and heavy high-pressure tanks are needed to contain it. Storing the fuel in the crystal lattice of the metal itself could be cheaper, lighter, and safer — but first the process of how hydrogen enters and leaves the metal must be better understood.
“Hydrogen can diffuse at relatively high rates in the metal, because it’s so small,” Tasan says. “If you take a metal and put it in a hydrogen-rich environment, it will uptake the hydrogen, and this causes hydrogen embrittlement,” he says. That’s because the hydrogen atoms tend to segregate in certain parts of the metal crystal lattice, weakening its chemical bonds.
The new way of observing the embrittlement process as it happens may help to reveal how the embrittlement gets triggered, and it may suggest ways of slowing the process — or of avoiding it by designing alloys that are less vulnerable to embrittlement.
Sandia’s San Marchi says that “this method may play an important role — in coordination with other techniques and simulation — to illuminate the hydrogen-defect interactions that lead to hydrogen embrittlement. With more comprehensive understanding of the mechanisms of hydrogen embrittlement, materials and microstructures can be designed to improve their performance under extreme hydrogen environments.”
The key to the new monitoring process was devising a way of exposing metal surfaces to a hydrogen environment while inside the vacuum chamber of a scanning electron microscope (SEM). Because the SEM requires a vacuum for its operation, hydrogen gas cannot be charged into the metal inside the instrument, and if precharged, the gas diffuses out quickly. Instead, the researchers used a liquid electrolyte that could be contained in a well-sealed chamber, where it is exposed to the underside of a thin sheet of metal. The top of the metal is exposed to the SEM electron beam, which can then probe the structure of the metal and observe the effects of the hydrogen atoms migrating into it.
The hydrogen from the electrolyte “diffuses all the way through to the top” of the metal, where its effects can be seen, Tasan says. The basic design of this contained system could also be used in other kinds of vacuum-based instruments to detect other properties. “It’s a unique setup. As far as we know, the only one in the world that can realize something like this,” he says.
Electron microscope images show the buildup of hydrogen within the crystal structure of a titanium alloy. The images reveal the way hydrogen, depicted in blue, preferentially migrates into the interfaces between crystal grains in the metal. Courtesy of the researchers.
In their initial tests of three different metals — two different kinds of stainless steel and a titanium alloy — the researchers have already made some new findings. For example, they observed the formation and growth process of a nanoscale hydride phase in the most commonly used titanium alloy, at room temperature and in real time.
Devising a leakproof system was crucial to making the process work. The electrolyte needed to charge the metal with hydrogen, “is a bit dangerous for the microscope,” Tasan says. “If the sample fails and the electrolyte is released into the microscope chamber,” it could penetrate far into every nook and cranny of the device and be difficult to clean out. When the time came to carry out their first experiment in the specialized and expensive equipment, he says, “we were excited, but also really nervous. It was unlikely that failure was going to take place, but there’s always that fear.”
Kaneaki Tsuzaki, a distinguished professor of chemical engineering at Kyushu University in Japan, who was not involved in this research, says this “could be a key technique to solve how hydrogen affects dislocation motion. It is very challenging because an acid solution for hydrogen cathodic charging is circulating into an SEM chamber. It is one of the most dangerous measurements for the machine. If the circulation joints leak, a very expensive scanning electron microscope (SEM) would be broken due to the acid solution. A very careful design and a very high-skill setup are necessary for making this measurement equipment.”
Tsuzaki adds that “once it is accomplished, outputs by this method would be super. It has very high spatial resolution due to SEM; it gives in-situ observations under a well-controlled hydrogen atmosphere.” As a result, he says, he believes that Tasan and Kim “will obtain new findings of hydrogen-assisted dislocation motion by this new method, solve the mechanism of hydrogen-induced mechanical degradation, and develop new hydrogen-resistant materials.”
The work was supported by the Exelon Corp through the MIT Energy Initiative's Low-Carbon Energy Center for Advanced Nuclear Energy Systems.
Over the course of the program, students take a deep-dive in a wide-range of topics and activities such as action planning, team building, group decision-making, and conflict resolution. The program is open to all undergraduate and graduate students and takes place at the Salvation Army Wonderland Conference Center in Sharon, Massachusetts.
Stephon Henry-Rerrie, a senior studying chemical engineering, wanted to take part in the program to break down barriers and have conversations that would develop his leadership skills.
“I expected to be vulnerable with my ideas and to lend myself to learning from other people,” Henry-Rerrie says. “Every conversation I had has impacted me with new knowledge or new perspectives that I’m able to add to my own way of viewing the world.”
Tracy Purinton, director of the MIT Leadership Center, says MIT LeaderShape is also an opportunity for faculty and staff facilitators and students to “explore together what leadership means to them, what leadership means in the context of community, and what leadership means in terms of bringing positive change into the world.”
Each individual creates a plan of action designed to improve the world on a range of topics: apathy, diversity and social justice, education, health care, and technological innovation. From engagement in powerful simulations, activities, and discussions, students learn how to develop their visions in a thoughtful and systematic way that they can execute or carry with them through their lifetime.
In addition to working and providing feedback on their visions in large groups, participants also have the opportunity to interact with renowned MIT faculty and administrators, known as cluster facilitators, in smaller group settings.
This year’s cluster facilitators included Suzy Nelson, vice president and dean of student life; Judy “JJ” Jackson, diversity and inclusion officer; Joseph Granado, associate director of student activities and leadership; Akunna Rosser, assistant director for prehealth advising; and Shawn Ferullo, chief of orthopedics and student health.
The MIT LeaderShape program, which started in 1995, is a partnership between MIT and LeaderShape Inc., a non-profit organization in Champaign, Illinois, that provides materials and the complete curriculum to all campus-based LeaderShape programs nationwide.
Over the years, the LeaderShape program has allowed many students to reflect on the impact they can make as leaders in the world, says MIT Vice President Kirk Kolenbrander.
“Students leave the experience with a plan of action that guides them for many years to come,” Kolenbrander says. “But what they leave with MIT is a deep and lasting commitment to improving our community.”
Graduate students facing obstacles in their lives turn to their academic advisors more frequently than any other on-campus resource, according to the most recent MIT Enrolled Graduate Student Survey.
In addition to the expected scholarly advice, feedback on research, and letters of recommendation, many graduate students have expressed appreciation for their advisors’ support of their overall wellbeing, as related in numerous nominations for the Committed to Caring (C2C) Award.
Since its establishment in 2014, the C2C Award has honored over 40 faculty members who are helping to set new standards for holistic graduate mentorship at MIT. Three of the most recent honorees, professors Cullen Buie, Hadley Sikes, and Justin Steil, support their students through collaborative planning, managing mental health, and promoting diversity and inclusivity.
Cullen Buie: Planning together
“I heard a quote once that ‘the best ability is availability’,” says Professor Cullen Buie of the Department of Mechanical Engineering, “and I’m constantly trying to figure out how to be more available for the people I mentor.”
Perhaps what stands out most about Buie’s advising style is his rigorous attention to planning: planning for the next step, planning for changes, and planning together. As one student nominator for the C2C award wrote: “The first thing [Buie] did after hiring me was ask me what I wanted to do with my degree, what were my end goals, what I wanted to do with my life.” This frank yet detailed conversation, the nominator writes, “set the tone for all of our future interactions … his feedback on my all of my work was tailored to my end goal.”
Buie explains that a major focus is to help advisees “think about their future long before those big life decisions have to be made.” This initial sit-down though is not the end of the planning process. After asking students very early in their training about career goals, Buie checks in twice per year to see if anything has changed.
When students are unsure of their goals, Buie encourages them to try new things and sample different career paths. Serving as a teaching assistant for a class or take a summer internship at a national laboratory may provide important exposure to different potential careers, he says.
Part of Buie’s planning program is the informal advising of his students, a mentoring guidepost identified by the C2C program. Being a well-rounded individual is vital, says Buie, for professional and personal reasons. “There is a tendency at a place like MIT to believe that the most important things are your tangible skills and your productivity,” Buie comments, but asserts that productivity may never be seen if one doesn’t communicate the work in a compelling manner. Most importantly, he adds, “years or even a lifetime of hard work can be derailed by ethical or moral failures.”
To keep student careers on track, Buie encourages them “to focus on their softer skills … including their ability to communicate verbally and in writing, and to develop their character.”
Hadley Sikes: Teaching beyond the lab
Professor Hadley D. Sikes of the Department of Chemical Engineering is more than just an academic advisor to her graduate students. She is a role model, a friend, and a sage mentor. One of her former students writes, “[Sikes] completely supported me as a person holistically, and allowed me to become the type of scientist and person that … I really wanted to become.”
Sikes is sensitive to conditions that detract from student wellness. From her decades of lab experience, Sikes identifies “overly long working hours,” “losing a sense of purpose,” and “feelings of isolation” as three of the most common contributors to poor mental health in graduate students. Her commitment to caring has driven her to develop ways fight these issues in her own lab.
“With ambitious projects, it is common to encounter difficulties, but working all the time is not the answer — nor is it sustainable,” Sikes says. To help battle such extended work hours in her lab, Sikes talks openly with her lab members and encourages them to prioritize interests and relationships outside of the lab.
When this sense of purpose fades, which Sikes often sees several years into doctoral research, she reminds her students of the impact of their work in the broader world outside of MIT. The impact of the Sikes Lab in the real-world includes improving diagnostics and therapeutic strategies for diseases like malaria, tuberculosis, and cancer.
Sikes notes that doctoral research can be isolating in many ways, both personally and professionally. To guard against professional isolation, “we form sub-groups of related thesis projects and meet regularly to help one another with troubleshooting.” To fight personal isolation, Sikes supports the social outings and informal gatherings her graduate students organize to enable getting to know one another outside of the lab.
In addition, Sikes does not always wait for her students to come to her but instead may proactively offer guidance, another of the mentoring guideposts identified by the C2C program. “In many cases,” one nominator shared, “I don’t even need to ask her for advice as she herself takes the initiative and educates me about various things.”
Justin Steil: Diversity and inclusivity
Creating an inclusive and supportive work environment for his students and colleagues — another mentoring guidepost identified by the C2C program — is fundamental to Professor Justin Steil’s practice as a professor in the Department of Urban Studies and Planning (DUSP).
“I research urban inequality, racial equity, and inclusive policymaking more broadly,” he remarks. “I strive to create a collaborative learning context in which we recognize that varying perspectives and experiences are essential to effective social science research.” In his view, an inclusive and collaborative approach helps to make research fun and exciting.
His efforts to create an equitable community within DUSP do not go unnoticed by his students. In a nomination letter for the C2C Award, one student wrote, “Steil made our class into a community. This was essential for the hard work ahead, and [it] empowered us to truly work well together.”
Steil’s concern for the wellbeing of his students goes beyond the classroom. Praising Steil, one student writes, “while others might be worried about getting tenure, Justin spends his time strategizing about how to protect our international students in a time of significant threat, about how to create safer environments for all students … and providing endless feedback and support.”
Steil promotes balance and perspective broadly. When asked what advice he would give to incoming graduate students at MIT, Steil offered: “Nurture the love of learning that brought you here. At the same time, keep the inevitable disappointments of research in perspective with the joys of discovery and the richness of life outside of research.”
The sum of Steil’s efforts has led his students to success. In one nominator’s words, “He expects a lot of us — so many readings — and of himself. The bar is high, and we [rise] to it, becoming better versions of ourselves.”
The Committed to Caring program is an initiative of the Office of Graduate Education and contributes to its mission of making graduate education at MIT “empowering, exciting, holistic, and transformative.”
C2C invites graduate students from across MIT’s campus to nominate professors whom they believed to be outstanding mentors. Selection criteria for the award include the scope and reach of advisor impact on the experience of graduate students, excellence in scholarship, and demonstrated commitment to diversity and inclusion.
By recognizing the human element of graduate education, C2C seeks to encourage good advising and mentorship across MIT’s campus.
Ken Urban, a senior lecturer in MIT’s Music and Theater Arts Program (MTA) is a screenwriter, director, musician, and highly acclaimed playwright, whose work has been performed in New York, London, Boston, and Washington. He joined the faculty in 2017 and now leads MIT’s playwriting program. Recently, he launched the MTA Playwrights Lab, a groundbreaking collaboration between MIT students and professional theater artists.
Q: You began college studying chemical engineering but instead became a world-class playwright. In what ways does your affinity for math and science inform your writing or your approach to theater-making? More broadly, do you see fruitful connections between the sciences, technology, and the arts?
A. In terms of how the engineer in me helps my playwriting, it comes down to a question of structure. The thing I loved about studying math and science was how it helped reveal the hidden structure of the universe, and answered questions about how things functioned. When I write a play, I am telling a story and I need to find the best structure to tell that story. When I was in Catholic grammar school, I loved to diagram sentences. We would take a complex sentence and break it down into the parts of speech, then represent that structure in a compact, orderly diagram. What I loved was how it combined my love of language with my love of problem solving. I do the same thing, in a way, when I write a play. I break down the story into scenes, into beats, trying to figure the best, most exciting way to reveal a character or the plot. That feels to me like the work of an engineer.
The larger connection between theater making, and science and technology is a little trickier. As a playwright invested in psychology, I love the unadorned quality of plays, of actors on a set being in a believable and emotionally-rich scenario. I admire the work of the Wooster Group, Reza Abdoh — I’m helping organize a retrospective of his work here on campus in February — and others in the experimental scene, who use technology as an integral part of their aesthetic. I just don’t tend to create work like that. Plays about science are especially hard. The amount of material you need to cover for a general audience to understand the science itself can make those plays feel exposition-heavy. That’s never a good thing. It might be why great plays on science are few and far between. But that isn’t stopping me from trying. I am currently working on a new play inspired by Henrietta Lacks and the ethical dilemmas regarding her immortal cells, which are used in labs across the globe.
That play will be workshopped here at MIT at our new theater building W97 in March. “The Immortals” is a dangerous comedy that uses the science as a springboard for a larger investigation of ethics. I am looking forward to my students seeing how a new play is developed in rehearsal, and no doubt, they will help the actors, the director, and me understand more about biomedical ethics.
Q: What have you learned as a playwright and dramatic writer that might help individuals and societies better navigate this complex time in history?
A. The best writing advice I ever got was from playwright Erik Ehn. He told me you need to feel the breath of your characters on your neck. I took that to mean you need to know them intimately. They cannot be held at a distance. I got that advice at a crucial moment. I was working on Sense of an Ending, a play about the Rwandan genocide, and I was frustrated because I couldn’t understand the two nuns in my play. I was basing these characters on two actual nuns who were convicted of “crimes against humanity” for their perceived role in a church massacre during the 1994 genocide of the Tutsis by the Hutu majority. But Erik’s advice helped me realize that I couldn’t look at these women from the outside. To make these characters work as dramatic engines, to make the play successful as an evening of theater, I had to understand why Sister Justina and Sister Alice did what they did. To see myself in them. To have empathy or at least understanding why these women did not help.
Understanding others is crucial right now. Remember, of course, that understanding is not the same as forgiving or ignoring conflict. But not to sit in a place of judgment: That is the goal. And that’s what being a playwright has taught me. Not to get too personal, but my father is a climate change denier. It enrages me. But what I have come to understand is that he is motivated by fear. To acknowledge the reality of global climate change is terrifying because it means we have to do something. And it means we are leaving a damaged world to the generations after us. Realizing this facet of my father helped me find ways to challenge him without dismissing him as a person. I ask my writers here at MIT to read an article about a 43-year-old female steelworker who is asked to train the Mexican workers who are replacing her when the American plant is shut down and the company moves. I chose this article because I know this is an experience far removed from my students’ lives, but I want them to do the hard work of finding themselves inside her experience and use that as a springboard for their new play. You cannot write convincingly until you care about people who are different from you.
Q: President Reif has said that the solutions to today’s challenges depend on pairing advanced technical and scientific capabilities with a broad understanding of the world’s political, cultural, and economic realities. What do you view as the main deterrent to such collaborative, multi-disciplinary problem-solving and how can we resolve it?
A. In key ways, knowledge has become more and more bifurcated. We have specialties and the solution to these global problems requires a multi-faceted approach. One of the joys of a career in the arts is that I am constantly being asked to go outside my comfort zone and to explore subject matter that is beyond my expertise. My PhdD is in English literature and my dissertation was focused on nihilism and 1990s British theater. I was trained to know a lot about Nietzsche and Sarah Kane. But what do I know about Henrietta Lacks and biomedical research? The Rwandan genocide? Being gay in Uganda?
Writing plays has helped me gain a broader understanding of our world. I don't know how to solve this vast problem [of siloed research], but I do hope that teaching dramatic writing at MIT helps in some small way. Perhaps, teaching students about the collaborations that foster new writing in the theater, also helps to catalyze new ideas and models for how collaborations might work in their own fields and areas of expertise.
Interview prepared by MIT SHASS Communicaitons
Series Editor: Emily Hiestand
Consulting Editor: Elizabeth Karagianis
Climate change is causing significant changes to phytoplankton in the world’s oceans, and a new MIT study finds that over the coming decades these changes will affect the ocean’s color, intensifying its blue regions and its green ones. Satellites should detect these changes in hue, providing early warning of wide-scale changes to marine ecosystems.
Writing in Nature Communications, researchers report that they have developed a global model that simulates the growth and interaction of different species of phytoplankton, or algae, and how the mix of species in various locations will change as temperatures rise around the world. The researchers also simulated the way phytoplankton absorb and reflect light, and how the ocean’s color changes as global warming affects the makeup of phytoplankton communities.
The researchers ran the model through the end of the 21st century and found that, by the year 2100, more than 50 percent of the world’s oceans will shift in color, due to climate change.
The study suggests that blue regions, such as the subtropics, will become even more blue, reflecting even less phytoplankton — and life in general — in those waters, compared with today. Some regions that are greener today, such as near the poles, may turn even deeper green, as warmer temperatures brew up larger blooms of more diverse phytoplankton.
“The model suggests the changes won’t appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and poles,” says lead author Stephanie Dutkiewicz, a principal research scientist at MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the Joint Program on the Science and Policy of Global Change. “That basic pattern will still be there. But it’ll be enough different that it will affect the rest of the food web that phytoplankton supports.”
Dutkiewicz’s co-authors include Oliver Jahn of MIT, Anna Hickman of the University of Southhampton, Stephanie Henson of the National Oceanography Centre Southampton, Claudie Beaulieu of the University of California at Santa Cruz, and Erwan Monier, former principal research scientist at the MIT Center for Global Change Science, and currently assistant professor at the University of California at Davis, in the Department of Land, Air and Water Resources.
The ocean’s color depends on how sunlight interacts with whatever is in the water. Water molecules alone absorb almost all sunlight except for the blue part of the spectrum, which is reflected back out. Hence, relatively barren open-ocean regions appear as deep blue from space. If there are any organisms in the ocean, they can absorb and reflect different wavelengths of light, depending on their individual properties.
Phytoplankton, for instance, contain chlorophyll, a pigment which absorbs mostly in the blue portions of sunlight to produce carbon for photosynthesis, and less in the green portions. As a result, more green light is reflected back out of the ocean, giving algae-rich regions a greenish hue.
Since the late 1990s, satellites have taken continuous measurements of the ocean’s color. Scientists have used these measurements to derive the amount of chlorophyll, and by extension, phytoplankton, in a given ocean region. But Dutkiewicz says chlorophyll doesn’t necessarily reflect the sensitive signal of climate change. Any significant swings in chlorophyll could very well be due to global warming, but they could also be due to “natural variability” — normal, periodic upticks in chlorophyll due to natural, weather-related phenomena.
“An El Niño or La Niña event will throw up a very large change in chlorophyll because it’s changing the amount of nutrients that are coming into the system,” Dutkiewicz says. “Because of these big, natural changes that happen every few years, it’s hard to see if things are changing due to climate change, if you’re just looking at chlorophyll.”
Modeling ocean light
Instead of looking to derived estimates of chlorophyll, the team wondered whether they could see a clear signal of climate change’s effect on phytoplankton by looking at satellite measurements of reflected light alone.
The group tweaked a computer model that it has used in the past to predict phytoplankton changes with rising temperatures and ocean acidification. This model takes information about phytoplankton, such as what they consume and how they grow, and incorporates this information into a physical model that simulates the ocean’s currents and mixing.
This time around, the researchers added a new element to the model, that has not been included in other ocean modeling techniques: the ability to estimate the specific wavelengths of light that are absorbed and reflected by the ocean, depending on the amount and type of organisms in a given region.
“Sunlight will come into the ocean, and anything that’s in the ocean will absorb it, like chlorophyll,” Dutkiewicz says. “Other things will absorb or scatter it, like something with a hard shell. So it’s a complicated process, how light is reflected back out of the ocean to give it its color.”
When the group compared results of their model to actual measurements of reflected light that satellites had taken in the past, they found the two agreed well enough that the model could be used to predict the ocean’s color as environmental conditions change in the future.
“The nice thing about this model is, we can use it as a laboratory, a place where we can experiment, to see how our planet is going to change,” Dutkiewicz says.
A signal in blues and greens
As the researchers cranked up global temperatures in the model, by up to 3 degrees Celsius by 2100 — what most scientists predict will occur under a business-as-usual scenario of relatively no action to reduce greenhouse gases — they found that wavelengths of light in the blue/green waveband responded the fastest.
What’s more, Dutkiewicz observed that this blue/green waveband showed a very clear signal, or shift, due specifically to climate change, taking place much earlier than what scientists have previously found when they looked to chlorophyll, which they projected would exhibit a climate-driven change by 2055.
“Chlorophyll is changing, but you can’t really see it because of its incredible natural variability,” Dutkiewicz says. “But you can see a significant, climate-related shift in some of these wavebands, in the signal being sent out to the satellites. So that’s where we should be looking in satellite measurements, for a real signal of change.”
According to their model, climate change is already changing the makeup of phytoplankton, and by extension, the color of the oceans. By the end of the century, our blue planet may look visibly altered.
“There will be a noticeable difference in the color of 50 percent of the ocean by the end of the 21st century,” Dutkiewicz says. “It could be potentially quite serious. Different types of phytoplankton absorb light differently, and if climate change shifts one community of phytoplankton to another, that will also change the types of food webs they can support. “
This research was supported, in part, by NASA and the Department of Energy.