Author: MIT News

Fluorescent dye could enable sharper biological imaging

by Anne Trafton |

Fluorescence imaging is widely used for visualizing biological tissues such as the back of the eye, where signs of macular degeneration can be detected. It is also commonly used to image blood vessels during reconstructive surgery, allowing surgeons to make sure the vessels are properly connected.

For these procedures, as well as others now in clinical trials, such as imaging tumors, researchers use a portion of the light spectrum known as the near-infrared (NIR) — 700 to 900 nanometers, just beyond what the human eye can detect. A dye that fluoresces at this wavelength is administered to the body or tissue and then imaged using a specialized camera. Researchers have shown that light with wavelengths greater than 1,000 nanometers, known as short-wave infrared (SWIR), offers much clearer images than NIR, but there are no FDA-approved fluorescence dyes with peak emission in the SWIR range.

A team of researchers at MIT and Massachusetts General Hospital has now taken a major step toward making SWIR imaging widely available. They have shown that an FDA-approved, commercially available dye now used for near-infrared imaging also works very well for short-wave infrared imaging.

“What we found is that this dye, which has been approved since 1959, is really the best, the brightest fluorophore that we know of at this point for imaging in the short-wave infrared,” says Moungi Bawendi, the Lester Wolf Professor of Chemistry at MIT. “Now clinicians can start to try short-wave imaging for their applications because they already have a fluorophore which is approved for use in humans.”

Imaging this dye with a camera that detects short-wave infrared light could allow doctors and researchers to obtain much better images of blood vessels and other body tissues for diagnosis and research.

Bawendi and former MIT research scientist Oliver Bruns are the senior authors of the study, which appears in the Proceedings of the National Academy of Sciences. The paper’s lead authors are MIT graduate students Jessica Carr and Daniel Franke.

Cutting through the fog

The dye that the researchers used in this study, known as indocyanine green (ICG), fluoresces most strongly around 800 nanometers, which falls within the near-infrared range. When injected into the body, it travels through the bloodstream, making it ideal for angiography (the visualization of blood flowing through vessels). Some robot-assisted surgical systems have incorporated NIR fluorescence imaging to help visualize blood vessels and other anatomical features.

The MIT team discovered ICG’s usefulness for SWIR imaging somewhat serendipitously. As part of a control experiment for another paper, they tested the fluorescence output of quantum dots against the fluorescence output of ICG in the short-wave infrared. They expected that ICG would have no output, but were surprised to discover that it actually produced a very strong signal.

Bawendi’s lab and other researchers have been interested in developing fluorophores for SWIR imaging because SWIR offers better contrast and clarity than NIR. Light with shorter wavelengths tends to scatter off of imperfections in objects that it strikes, but as wavelengths become longer, scattering is greatly reduced.

“In the near-infrared, a lot of the features you see in tissue can look foggy, and once you move into the short-wave infrared, the image clears up and everything becomes sharp,” Bruns says.

Short-wave infrared can also penetrate deeper into tissue, although calculating exactly how far is a complicated process, the researchers say, because it depends on the size of the structure being viewed and the field of view of the microscope. In the new study, the researchers were able to see several hundred micrometers into tissue using a regular fluorescence microscope. Normally, this depth can be reached only with two-photon microscopy, a much more complicated and expensive type of imaging.

“We found that short-wave infrared is particularly useful for imaging small objects that are on top of a large background, so when you want to do angiography of small vessels, or capillaries, that’s significantly easier in the short-wave infrared than in the near-infrared,” Franke says.

A strong signal

In their study, the researchers further explored ICG and showed that it gives a stronger signal than other SWIR dyes now in development. Previous studies of ICG had focused on its emission around 800 nanometers, where it fluoresces the brightest, so no one had observed that the dye also produced a strong signal at longer wavelengths. Though it doesn’t fluoresce efficiently in the shortwave-infrared range, ICG absorbs so much light that if even a small percentage is emitted as fluorescent light, the signal is brighter than that produced by other SWIR dyes.

The researchers also found that ICG is bright enough that it can produce images quickly, which is important for capturing motion.

“If you don’t have a strong enough signal, it slows down how long it takes to take the image, so you can’t use it for imaging motion such as blood flowing or the heart beating,” Carr says.

The researchers also tested another dye that works in the near-infrared. This dye, called IRDye 800CW, is similar to ICG and can be attached to antibodies that target proteins such as those found on tumors. They found that IRDye 800CW also fluoresces brightly in the shortwave-infrared light, thought not as brightly as ICG, and showed that they could use it to image a cancerous tumor in the brains of mice.

To do shortwave-infrared imaging, research labs and hospitals would need to switch from the silicon cameras now used for NIR imaging to an indium gallium arsenide (InGaAs) camera. Until recently, these cameras have been prohibitively expensive, but the prices have been coming down in the past several years.

The research team is now further investigating why ICG works so well for shortwave-infrared imaging, and is trying to identify the optimal wavelength for its use, which they hope will help them determine the best applications for this kind of imaging. They are also working with other labs to develop dyes that are similar to ICG and might work even better.

The research was funded by the National Institutes of Health through the Laser Biomedical Research Center; MIT through the Institute for Soldier Nanotechnologies; the National Science Foundation; and the Department of Energy Office of Science.

Innovation fosters inclusive teaching at MIT

by Alison Trachy, Registrar’s Office |

“What are we doing to enable every student at MIT to make the most of the opportunities that are here for them?” Vice Chancellor Ian A. Waitz posed this question at the start of the March 9 MacVicar Day symposium, which was titled “Inclusive Pedagogies: Building a Vibrant Community of Learners at MIT.”

The MacVicar Faculty Fellows Program, which recognizes exceptional undergraduate teaching, was established in honor of Margaret MacVicar. MacVicar was, among many things, the first dean for undergraduate education, the founder of the Undergraduate Research Opportunities Program (UROP), and a crusader for diversity and inclusiveness at MIT.

This year’s fellows are David Autor, the Ford Professor of Economics and associate head of the department; Christopher Capozzola, an associate professor of history; Shankar Raman, a professor of literature; and Merritt Roe Smith, the Leverett and William Cutten Professor of the History of Technology in the Department of History and the Program in Science, Technology, and Society (STS).

After introducing the 2018 fellows, Waitz noted several ways in which MIT has responded to calls for more inclusivity, including implicit bias training, increases to financial aid, and the creation of the special subjects MIT and Slavery and Designing the First Year at MIT. But, citing recent student survey responses, he acknowledged that there was still much to do. He hoped that the symposium would give the audience the opportunity to learn from instructors who have made considerable progress in these efforts.

The term “inclusive pedagogies” refers to classroom practices and teaching strategies that include, engage, and support all students. As the afternoon’s presenters demonstrated, approaches to inclusive teaching can vary greatly, and the path to change is often unexpected and surprising.

The (stereotype) threat is real

The first speaker was Catherine Drennan, a professor of chemistry and biology and a professor and investigator with the Howard Hughes Medical Institute. She is also a 2015 MacVicar fellow.

Drennan recounted how several years ago she was asked to speak with underrepresented minority students majoring in chemistry, and was alarmed to find that there were only two. After meeting with one of the students, she learned that he was discouraged because he did not see anyone in the field who looked like him and did not feel that his teaching assistants believed in him.

Drennan recognized that the student was experiencing stereotype threat, the perceived danger of confirming a negative generalization about a racial, ethnic, gender, or cultural group. Worrying about being stereotyped can lead to feelings of being judged unfairly and can hurt students’ performance, perpetuating the problem.

“I really like doing research in education,” Drennan reflected. “I always learn something I’m not expecting when I ask questions.”

Knowing that something had to change, she created a series of videos, which highlighted the diverse backgrounds of those in the field of chemistry, and a booklet, detailing stereotype threat and ways to counteract it. After implementing these materials in department-wide teaching assistant (TA) training, she began to host weekly “clicker competitions” in her 5.111 (Principles of Chemical Science) classes. Recitation groups, led by their TAs, faced off against each other to see who could answer the most questions correctly.

The competitions, which have been replicated at the University of California at Irvine, with similar results, allowed the TAs and students to bond. The TAs became more comfortable teaching and supporting their students, who in turn experienced a greater sense of belonging.

Active learning as inclusive learning

Katrina LaCurts, a lecturer in the electrical engineering and computer science department, presented the results of her attempt to make class participation more equitable and effective in 6.033 (Computer System Engineering).

6.033 is a communication-intensive within the major (CI-M) subject, and as such focuses heavily on writing and oral presentation. Each recitation is based on a different technical paper, which students are expected to read and be ready to discuss in class. In the past, discussions would often be dominated by just a few students, or students would arrive to class unprepared and disengaged.

Hoping that a more intimate environment would lead to more participation, LaCurts encouraged her recitation instructors to incorporate small group techniques into their classes. But she quickly discovered that there was a big difference between suggesting active learning and understanding what that entailed. She found, like Drennan had in 5.111, that change would come only when instructors were sufficiently trained.

After explaining the benefits of an active learning approach, LaCurts conducted training and worked with her instructors to apply it. When compared to prior offerings of the subject, from what LaCurts and her staff jokingly call “the dark times,” students are more engaged and have a greater sense of camaraderie with their classmates. Furthermore, instructors have found that students exhibit less anxiety and a more thorough understanding of the material. Lessons are more effective and enjoyable for all involved.

Finding a home in education

Education subjects “recognize [students’] diverse set of interests and finds [a] home for them,” said Eric Klopfer, a professor in and the director of the Scheller Teacher Education Program (STEP).

There is an overrepresentation of women and underrepresented minorities in the introductory education subjects. According to Klopfer, many students were motivated to take the class because of their personal experience as part of a group that “wasn’t expected to succeed in math and science.” Their success in STEM has compelled them to give back.

Students learn about inclusive pedagogies by implementing them at the K-12 level, designing games, teaching lessons, and making presentations. This practice of working in schools gives them firsthand experience of being both teacher and student. They observe not only the diverse backgrounds of the students themselves, but also the diversity of the ways in which students learn.

With this diversity in mind, Meredith Thompson, a research scientist at the Teaching Systems Lab (TSL) and STEP, presented Swipe Right for CS. The game, which is being developed as part of a UROP, allows teachers to practice connecting students’ strengths and interests to computer science. Some rationales don’t fit, Thompson explained, and feeling and understanding that students’ motivations for learning vary is of enormous import to aspiring teachers.

Inquiry-based learning

Christine Ortiz, the former dean for graduate education and the current Morris Cohen Professor of Materials Science and Engineering, was the afternoon’s final speaker.

In a new special subject, 3.S03 (Materials, Societal Impact and Social Innovation), Ortiz and her students explored what could happen if inclusion was incorporated into every step of the learning process. Ortiz cited the lack of inclusionary perspective in pedagogy as one of the causes for disparity in STEM fields.

In response to this inequality, the class examined two bodies of literature — course-based undergraduate research and scholarly work in equity. When considered together, these areas of study could inform one another and lead to new, innovative approaches in inquiry-based learning.

After students were equipped with a foundation of inclusive principles to internalize and use in their work, they completed a research project. Each step of the process was intentional, with careful consideration given to how to include ideas of equity. Ortiz provided continuous feedback to her students, making revision an iterative and edifying process. One of the completed projects looked at sustainability as a form of social justice, with students designing a process to recycle 3-D-printed materials. This class, Ortiz concluded, “was really a joy to teach.”

In closing, Vice Chancellor Waitz expressed his appreciation for all of the presenters and their thoughtful efforts. “Thank you for trying new things. It’s wonderful to see the impacts of this work.”

MIT graduate engineering, business, science programs ranked highly by U.S. News for 2019

by MIT News |

MIT’s graduate program in engineering has again earned a No. 1 spot in U.S. News and World Report’s annual rankings, a place it has held since 1990, when the magazine first ranked such programs.

The MIT Sloan School of Management also placed highly, occupying the No. 5 spot for the best graduate business program.

This year, U.S. News also ranked the nation’s top PhD programs in the sciences, which it last evaluated in 2014. The magazine awarded No. 1 spots to MIT programs in biology (tied with Stanford University and the University of California at Berkeley), computer science (tied with Carnegie Mellon University, Stanford, and Berkeley), and physics (tied with Stanford). No. 2 spots went to MIT programs in chemistry (tied with Harvard University, Stanford, and Berkeley), earth sciences (tied with Stanford and Berkeley); and mathematics (tied with Harvard, Stanford, and Berkeley).

Among individual engineering disciplines, MIT placed first in six areas: aerospace/aeronautical/astronautical engineering (tied with Caltech), chemical engineering, computer engineering, electrical/electronic/communications engineering (tied with Stanford and Berkeley), materials engineering, and mechanical engineering. It placed second in nuclear engineering.

In the rankings of individual MBA specialties, MIT placed first in information systems and production/operations. It placed second in supply chain/logistics and third in entrepreneurship.

U.S. News does not issue annual rankings for all doctoral programs but revisits many every few years. This year, MIT ranked in the top five for 24 of the 37 science disciplines evaluated.

The magazine bases its rankings of graduate schools of engineering and business on two types of data: reputational surveys of deans and other academic officials, and statistical indicators that measure the quality of a school’s faculty, research, and students. The magazine’s less-frequent rankings of programs in the sciences, social sciences, and humanities are based solely on reputational surveys.

MIT rates No. 1 in 12 subjects in 2018 QS World University Rankings

by Stephanie Eich, Resource Development |

MIT has been honored with 12 No. 1 subject rankings in the QS World University Rankings for 2018.

MIT received a No. 1 ranking in the following QS subject areas: Architecture/Built Environment; Linguistics; Chemical Engineering; Civil and Structural Engineering; Computer Science and Information Systems; Electrical and Electronic Engineering; Mechanical, Aeronautical and Manufacturing Engineering; Chemistry; Materials Science; Mathematics; Physics and Astronomy; and Statistics and Operational Research.

Additional high-ranking MIT subjects include: Art and Design (No. 4), Biological Sciences (No. 2), Earth and Marine Sciences (No. 3), Environmental Sciences (No. 3), Accounting and Finance (No. 2), Business and Management Studies (No. 4), and Economics and Econometrics (No. 2).

Quacquarelli Symonds Limited subject rankings, published annually, are designed to help prospective students find the leading schools in their field of interest. Rankings cover 48 disciplines and are based on an institute’s research quality and accomplishments, academic reputation, and graduate employment.

MIT has been ranked as the No. 1 university in the world by QS World University Rankings for six straight years.

Scientists deliver high-resolution glimpse of enzyme structure

by Anne Trafton |

Using a state-of-the-art type of electron microscopy, an MIT-led team has discovered the structure of an enzyme that is crucial for maintaining an adequate supply of DNA building blocks in human cells.

Their new structure also reveals the likely mechanism for how cells regulate the enzyme, known as ribonucleotide reductase (RNR). Significantly, the mechanism appears to differ from that of the bacterial version of the enzyme, suggesting that it could be possible to design antibiotics that selectively block the bacterial enzyme.

“People have been trying to figure out whether there is something different enough that you could inhibit bacterial enzymes and not the human version,” says Catherine Drennan, an MIT professor of chemistry and biology and a Howard Hughes Medical Institute Investigator. “By considering these key enzymes and figuring out what are the differences and similarities, we can see if there’s anything in the bacterial enzyme that could be targeted with small-molecule drugs.”

Drennan is one of the senior authors of the study, which appears in the Feb. 20 issue of the journal eLife. JoAnne Stubbe, the Novartis Professor of Chemistry Emerita at MIT, and Francisco Asturias, an associate professor of biochemistry at the University of Colorado School of Medicine, are also senior authors. The paper’s lead authors are MIT research scientist Edward Brignole and former Scripps Research Institute postdoc Kuang-Lei Tsai, who is now an assistant professor at the University of Texas Houston Medical Center.

An unusual enzyme

The RNR enzyme, which is found in all living cells, converts ribonucleotides (the building blocks of RNA) to deoxyribonucleotides (the building blocks of DNA). Cells must keep a sufficient stockpile of these building blocks, but when they accumulate too many, RNR is shut off by a deoxynucleotide molecule known as dATP. When more deoxynucleotides are needed, a related molecule called ATP binds to RNR and turns it back on.

An unusual feature of RNR is that it can catalyze the production of four different products: the nucleotide bases often abbreviated as A, G, C, and T. In 2016, Drennan discovered that the enzyme achieves this by changing its shape in response to regulatory molecules.

Most of the researchers’ previous work on RNR structure has focused on the version found in E. coli. For those studies, they used X-ray crystallography, a technique that can reveal the atomic and molecular structure of a protein after it has been crystallized.

In the new study, Drennan and her colleagues set out to examine the human version of RNR. This protein’s structure, which turned out to be very different from the bacterial version, proved elusive using X-ray crystallography, which doesn’t work well for proteins that don’t readily crystallize. Instead, the researchers turned to an advanced form of microscopy known as cryo-electron microscopy (cryo-EM).

Until recently, cryo-EM typically offered resolution of about 10 to 20 angstroms, which might reveal the overall shape of a protein but no detail about the position and shape of smaller structural units within it. However, in the past few years, technological advances have led to an explosion in the number of structures achieving resolutions of about 3 angstroms. That is high enough to trace individual protein chains within the larger molecule, as well as internal structures such as helices and even side chains of amino acids.

Scientists already knew that RNR consists of two protein subunits known as alpha and beta. Using cryo-EM, the MIT team found that the human version of the enzyme forms a ring made from six of the alpha subunits. When ATP, which activates RNR, is bound to the enzyme, the ring is unstable and can be easily opened up, allowing the beta subunit to make its way into the ring. This joining of alpha and beta allows the enzyme’s active site, located in the beta subunit, to perform the chemical reactions necessary to produce deoxynucleotides.

However, when the inhibitor dATP is present, the ring becomes much more rigid and does not allow the beta subunit to enter. This prevents the enzyme from catalyzing the production of deoxynucleotides.

Designing drugs

Several cancer drugs now in use or in development target the human version of RNR, interfering with cancer cells’ ability to reproduce by limiting their supply of DNA building blocks. The MIT team has found evidence that at least one of these drugs, clofarabine diphosphate, works by inducing the formation of rigid 6-unit alpha rings.

This 6-unit ring is not found in the bacterial form of RNR, which instead assembles into a distinct ring containing four alpha subunits and four beta subunits. This means it could be possible to design antibiotics that target the bacterial version but not the human version, Drennan says.

She now plans to investigate the structures of other protein molecules that are difficult to study with X-ray crystallography, including proteins with iron sulfur clusters, which are found in many metabolic pathways. The microscopy work in this study was performed at the Scripps Research Institute, but when MIT’s new MIT.nano building opens, it will house two cryo-EM microscopes that will be available to the MIT community as well as other potential users in industry and academia.

“The technological advances that have allowed cryo-EM to get to such high resolution are really exciting,” Drennan says. “It’s really starting to revolutionize the study of biology.”

The research was funded by the National Institutes of Health.

A lifelong search for new catalysts

by Anne Trafton |

On a summer evening in 1973, Richard Schrock came home from his job at DuPont’s Central Research Department and told his wife, Nancy, “I think I’ve done something important.”

As part of his research exploring synthesis of new polymers, Schrock had created a novel type of molecule with a double bond between a metal and a carbon atom. This type of compound, known as an alkylidene, had never been seen before.

Schrock, this year’s recipient of the James R. Killian Jr. Faculty Achievement Award, described at yesterday’s Killian Lecture how that discovery set him on a path that would ultimately lead to the development of catalysts that can control the formation of many kinds of organic compounds. This work, which has been applied in the chemical industry to efficiently produce pharmaceuticals, plastics, fuels, and other substances, also earned Schrock the Nobel Prize in Chemistry in 2005.

Established in 1971 to honor MIT’s 10th president, the Killian Award recognizes extraordinary professional achievements by an MIT faculty member. The award citation noted that Schrock, the Frederick G. Keyes Professor of Chemistry at MIT, has also made valuable contributions to MIT’s educational mission: He has mentored more than 185 graduate students and postdocs, and continues to serve as a lecturer in MIT’s first-year chemistry course.

“He began this challenging teaching assignment in the early 1990s and returned to it after winning the Nobel Prize, inspiring undergraduates to unravel the beauty of molecular structures and chemical reactions,” said Susan Silbey, chair of the MIT faculty, in presenting the award before yesterday’s lecture.

“Magical little machines”

Schrock’s interest in chemistry was kindled at age 8, when his older brother, Ted, gave him a chemistry set. After earning his bachelor’s degree in chemistry from the University of California at Riverside, he did his graduate studies at Harvard University, where he worked in the lab of inorganic chemist John Osborn.

“John got me interested in catalysis,” Schrock recalled. “Catalysts are these magical little machines that can make something over and over again.”

After earning his PhD, Schrock spent a year at Cambridge University, where he met a scientist on sabbatical from DuPont, and that connection eventually led to a job offer for Schrock. When he got there, “They told me, why don’t you go make a new polymer?” he said. “That means you’ve got to make a new catalyst.”

DuPont had done some previous work using the metals chromium, vanadium, and titanium as catalysts, but Schrock turned his attention to tantalum. That summer in 1973, he realized that he had created a compound containing a double bond between tantalum and carbon.

Schrock joined the MIT faculty in 1975, and through further research there he uncovered the role that these metal-carbon bonds play in a type of reaction known as olefin metathesis. This reaction had been first seen in the 1950s but was not well understood.

Yves Chauvin, who shared the 2005 Nobel Prize with Schrock, first proposed the mechanism for this kind of reaction in 1971. Olefin metathesis involves breaking and making double bonds between carbon atoms, with help from a catalyst that contains a metal-carbon double bond, which forms a ring that contains the metal and three carbon atoms.

In 1986, Schrock developed the first catalyst that could perform this type of reaction: an atom of the metal molybdenum attached to organic structures known as ligands. He won the Nobel Prize for this work in 2005 but said yesterday, “At the time of the Nobel Prize, the most important problems in this area weren’t solved.”

One major issue to be resolved was how to control the configuration of the olefin products, which can occur in one of two configurations. Since 2005, Schrock has developed new catalysts that can control these configurations, making it easier for chemists to design possible new drugs and other useful compounds.

There is always room for improvement in designing new catalysts and reactions, noted Schrock, who described himself as “a molecular engineer.”

“Once you have a reaction that you know works, you want to build on it, tinker with it, and make it go in the direction you want it to go,” he said.

Beyond Haber-Bosch

Schrock also described his other major research focus, which centers on nitrogen. Nitrogen, found in proteins, DNA, and RNA, is essential for all life on Earth, but for most organisms to use it, it has to be converted to ammonia. Many microbes can perform this conversion, and in the early 1900s, scientists began seeking their own methods.

Two German scientists, Fritz Haber and Carl Bosch, developed a chemical process that is now used to produce 300 million tons of ammonia every year, for use in fertilizer and other compounds. It is estimated that 1.4 percent of all energy used by humans goes into producing ammonia through this process, in part because the reaction must be performed at very high temperatures and pressures.

The process also releases carbon dioxide as a byproduct, so Schrock and others have been seeking alternative ways to convert nitrogen to ammonia.

In a landmark 2003 Science paper, Schrock reported that using a molybdenum catalyst he could produce ammonia in a multistep reaction that can take place at room temperature and atmospheric pressure. The process is not yet efficient enough for industrial use, but Schrock hopes that with further refinement, it could be useful within the next 20 years.

“I don’t think it’s going to replace Haber-Bosch, but I think it can reduce the amount of carbon dioxide we release into the atmosphere,” he said.

After receiving Killian Award, Richard Schrock reflects on a life in chemistry

by MIT News |

F.G. Keyes Professor Richard Royce Schrock holds many titles, not the least of which is Nobel laureate. An organometallic chemistry pioneer, Schrock received the Nobel for his contributions to the development of the olefin metathesis reaction (now used for the efficient and more environmentally friendly production of important pharmaceuticals, fuels, and other products) on Oct. 5, 2005. That momentous afternoon, a crowd packed into Huntington Hall to witness Schrock deliver his Nobel lecture. “It was an impromptu talk,” Schrock recalls. “No slides, and no preparation.” This year, on Feb. 15, another crowd will congregate in the very same room, this time to watch Schrock give the 2017–2018 Killian Lecture, “Adventures in Organic Chemistry and Catalysis.”

Schrock was named the winner of the 2017–2018 James R. Killian Jr. Faculty Achievement Award this past May. In terms of the honor and excitement that came with receiving the award, “The Killian Prize is equal to [the Nobel],” says Schrock. The Killian Prize was established in the spring of 1971 as a permanent tribute to James R. Killian Jr., former MIT president (1948–1959) and chairman of the Corporation (1959–1971). The award is given in recognition of extraordinary professional achievement by MIT faculty members and aims to communicate their accomplishments to members of the Institute community. The Department of Chemistry is proud to have had several of its faculty members receive this honor since the award’s inception: Stephen J. Lippard, JoAnne Stubbe, George H. Büchi, John S. Waugh, and Alexander Rich were all Killian Lecturers.

Before being named a Killian Lecturer or a Nobel laureate, and even before a type of metal carbene was named in his honor, an 8-year-old Schrock was influenced by an older brother, five years his senior. “My brother Ted was very good in chemistry; he went on to be a surgeon,” says Schrock. “For some reason, I guess because he loved chemistry, he gave me a chemistry set for Christmas, and there was pretty good stuff in it.” Schrock acquired some of his brother’s old high school chemistry books, and went ahead to procure the chemicals required to conduct some of his first experiments — sweet-smelling esters such as ethyl acetate.

A watershed in chemistry

Schrock received his PhD from Harvard University in 1971. Following a fellowship at Cambridge University, he found himself working in the Central Research and Development Department of DuPont. It was there that Schrock experienced a watershed moment in his life.

“There’s a notebook page from when I was at DuPont — dated July 27, 1973,” Schrock recalls. “It was witnessed by someone in my lab, and I signed it on August 7, 1973, about 10 days later. It must have been that day when I went home and told my wife, ‘I think I’ve done something important.’”

Schrock had discovered a double bond compound, which had never been suspected — the reaction had never been observed. The compound was well-behaved and one of a kind. The discovery of this compound ultimately led Schrock to become the first to elucidate the structure and mechanism of so-called black box olefin metathesis catalysts.

The future of chemistry

As for the future — Schrock believes we continue to push back the frontiers.

“Everything is chemistry,” says Schrock. “We can explain so much if we understand the basics and the applications of chemistry. Whether it’s life sciences, different kinds of polymers, electronic conducting materials, organic conducting materials — all the things that are being done now in the chemical industry and beyond, really rely on chemistry.” Schrock believes in the limitless potential of discovery, and that the answers and cures to the currently incurable conundrums exist. It’s up to researchers to have that breakthrough moment, he says.

“Some people say, ‘Oh, everything’s been discovered,’” Schrock muses. “But people said that at the end of the 19th century, before they even knew what an atom was.”

Susan Solomon awarded the 2018 Crafoord Prize

by Helen Hill, EAPS |

Susan Solomon, the Lee and Geraldine Martin Professor of Environmental Studies at MIT, has been awarded the 2018 Crafoord Prize.

Announced today, Solomon is being honored “for fundamental contributions to understanding the role of atmospheric trace gases in Earth’s climate system.”

For more than 30 years, Solomon’s studies have been at the forefront of research into the ozone layer and its role in the Earth’s climate system, with the chemical reactions she proposed now one of the cornerstones of stratospheric chemical modeling.

Now, together with fellow legendary climate scientist Syukuro Manabe of Princeton University, who has also played a dominant role in climate research over multiple decades, Solomon is being rewarded with this year’s Sweden’s Crafoord Prize in Geosciences, worth 6 million kronor, for contributing decisive knowledge to aid in combating one of the greatest challenges of our time.

Solomon is internationally recognized as a leader in atmospheric science, particularly for her insights in explaining the cause of the Antarctic ozone “hole.”

In the 1980s, Solomon solved the puzzle of the Antarctic ozone hole’s appearance, using theoretical and chemical measurement-focused studies in the Antarctic atmosphere. She examined the ice crystals in the stratospheric clouds that form there every year due to the extreme cold. These ice crystals cause the initiation of chemical processes that differ from those that were previously assumed to occur. On this basis, Solomon presented a theory that explained the link between manmade chlorofluorocarbon (CFC) emissions and the chemical processes taking place in the Antarctic stratosphere in the early spring — ones that led to the extensive depletion of its ozone layer. Her theory was verified by the results of the measurements conducted in the stratosphere. Later, Solomon showed how the thickness of the ozone layer in the southern hemisphere affects atmospheric flows and temperatures all the way down to ground level.

Subsequently, she and her colleagues have made multiple important contributions to understanding chemistry/climate coupling, including leading research on the irreversibility of global warming linked to anthropogenic carbon dioxide emissions, and on the influence of the ozone hole on the climate of the southern hemisphere. Her current focus is on issues relating to both atmospheric chemistry and climate change.

The Crafoord Prize is awarded in partnership between the Royal Swedish Academy of Sciences and the Crafoord Foundation, with the academy responsible for selecting the Crafoord Laureates. Awards are presented in one of four disciplines each year: mathematics and astronomy, geosciences, biosciences, or polyarthritis (such as rheumatoid arthritis). Awarded are chosen to complement those of the Nobel Prizes.

Professor Solomon will travel to Sweden to give her prize lecture at Lund University on May 22, and receive her prize at the Royal Swedish Academy of Sciences on May 24, in the presence of H. M. King Carl XVI Gustaf and H. M. Queen Silvia of Sweden.

Former professor in the Department of Earth, Atmospheric and Planetary Sciences (EAPS) Edward N. Lorenz (together with Henry Stommel) received the first Crafoord Prize in Geoscience in 1983. Former EAPS geosciences professor Peter Molnar was awarded the prize in 2014.

Twelve School of Science faculty members appointed to named professorships

by School of Science |

The School of Science has appointed 12 faculty members to named professorships.

The new appointments are:

Stephen Bell, the Uncas (1923) and Helen Whitaker Professor in the Department of Biology: Bell is a leader in the field of DNA replication, specifically in the mechanisms controlling initiation of chromosome duplication in eukaryotic cells. Combining genetics, genomics, biochemistry, and single-molecule approaches, Bell has provided a mechanistic picture of the assembly of the bidirectional DNA replication machine at replication origins.

Timothy Cronin, the Kerr-McGee Career Development Assistant Professor in the Department of Earth, Atmospheric and Planetary Sciences: Cronin is a climate physicist interested in problems relating to radiative‐convective equilibrium, atmospheric moist convection and clouds, and the physics of the coupled land‐atmosphere system.

Nikta Fakhri, the Thomas D. and Virginia W. Cabot Assistant Professor in the Department of Physics: Combining approaches from physics, biology, and engineering, Fakhri seeks to understand the principles of active matter and aims to develop novel probes, such as single-walled carbon nanotubes, to map the organization and dynamics of nonequilibrium heterogeneous materials.

Robert Griffin, the Arthur Amos Noyes Professor in the Department of Chemistry: Griffin develops new magnetic resonance techniques to study molecular structure and dynamics and applies them to interesting chemical, biophysical, and physical problems such as the structure of large enzyme/inhibitor complexes, membrane proteins, and amyloid peptides and proteins.

Jacqueline Hewitt, the Julius A. Stratton Professor in Electrical Engineering and Physics in the Department of Physics: Hewitt applies the techniques of radio astronomy, interferometry, and image processing to basic research in astrophysics and cosmology. Current topics of interest are observational signatures of the epoch of reionization and the detection of transient astronomical radio sources, as well as the development of new instrumentation and techniques for radio astronomy.

William Minicozzi, the Singer Professor of Mathematics in the Department of Mathematics: Minicozzi is a geometric analyst who, with colleague Tobias Colding, has resolved a number of major results in the field, among them: proof of a longstanding S.T. Yau conjecture on the function theory on Riemannian manifolds, a finite-time extinction condition of the Ricci flow, and recent work on the mean curvature flow.

Aaron Pixton, the Class of 1957 Career Development Assistant Professor in the Department of Mathematics: Pixton works on various topics in enumerative algebraic geometry, including the tautological ring of the moduli space of algebraic curves, moduli spaces of sheaves on 3-folds, and Gromov-Witten theory.

Gabriela Schlau-Cohen, the Thomas D. and Virginia W. Cabot Assistant Professor in the Department of Chemistry: Schlau-Cohen’s research employs single-molecule and ultrafast spectroscopies to explore the energetic and structural dynamics of biological systems. She develops new methodology to measure ultrafast dynamics on single proteins to study systems with both sub-nanosecond and second dynamics. In other research, she merges optical spectroscopy with model membrane systems to provide a novel probe of how biological processes extend beyond the nanometer scale of individual proteins.

Alexander Shalek, the Pfizer Inc.-Gerald Laubach Career Development Assistant Professor in the Department of Chemistry: Shalek studies how our individual cells work together to perform systems-level functions in both health and disease. Using the immune system as his primary model, Shalek leverages advances in nanotechnology and chemical biology to develop broadly applicable platforms for manipulating and profiling many interacting single cells in order to examine ensemble cellular behaviors from the bottom up.

Scott Sheffield, the Leighton Family Professor in the Department of Mathematics: Sheffield is a probability theorist, working on geometrical questions that arise in such areas as statistical physics, game theory and metric spaces, as well as long-standing problems in percolation theory.

Susan Solomon, the Lee and Geraldine Martin Professor in Environmental Studies in the Department of Earth, Atmospheric and Planetary Sciences: Solomon focuses on issues relating to both atmospheric climate chemistry and climate change, and is well-recognized for her insights in explaining the cause of the Antarctic ozone “hole” as well as her research on the irreversibility of global warming linked to anthropogenic carbon dioxide emissions and on the influence of the ozone hole on the climate of the southern hemisphere.

Stefani Spranger, the Howard S. (1953) and Linda B. Stern Career Development Assistant Professor in the Department of Biology: Spranger studies the interactions between cancer and the immune system with the goal of improving existing immunotherapies or developing novel therapeutic approaches. Spranger seeks to understand how CD8 T cells, otherwise known as killer T cells, are excluded from the tumor microenvironment, with a focus on lung and pancreatic cancers.

3Q: Institute Professor John Deutch on maintaining US leadership in technological innovation

by David L. Chandler |

MIT Institute Professor John Deutch, who has been on the MIT faculty since 1970, has served as a department head, dean of the School of Science, and provost, and has published over 160 technical publications as well as numerous publications on technology, energy, international security, and public policy issues. He served in the U.S. government as director of central intelligence from 1995 to 1996, as deputy secretary of defense from 1994 to 1995, and in other posts in the departments of Defense and Energy. He is a member of the nonpartisan Aspen Strategy Group, which is composed of current and former policymakers, academics, journalists, and business leaders whose aim is to explore foreign policy and national security challenges facing the United States. The group has just released its annual report, and it includes a chapter co-written by Deutch and former U.S. Secretary of State Condoleezza Rice, about how the U.S. should deal with the risk of losing important intellectual property rights regarding technological innovations, in the face of efforts by China to acquire such technology through underhanded means. MIT News asked Deutch to describe the potential risks and remedies for such actions that he and Rice outlined in their report.

Q: What was the challenge that you and Prof. Rice, now at Stanford Business School, were asked to address in this piece, and what conclusions did you reach?

A: This year the subject [of the Aspen Strategy Group’s annual report] was the future challenges we see for policy. There was a lot of talk about China and what its relationship with the United States is likely to be, and in the course of this there was a lot of discussion about national security and the tremendous emphasis in China’s new five-year plan on technology, in key areas such as robotics, artificial intelligence, and machine learning. There also was a great deal of discussion about nefarious activities by some in China, including trying to get certain Chinese nationals who live here to provide information to the Chinese government to help them acquire this advanced technology. As a result of that, there’s been a hint of a new set of proposals from some elements of the natonal security community to, first, control information in the United States from leaving the country, and, second, restrict Chinese nationals from participating in certain kinds of research projects. Condi and I decided to write a short piece about the danger of these proposals.

Basically our view was, yes, the Chinese are putting a greater emphasis on technology; they are growing very fast and they’re increasingly competent, and so we should expect greater competition. And yes, they are performing illegal acts against the U.S., especially theft of intellectual property. The U.S. should do everything it can to push back on that effort and prevent it if possible. But the idea that we should respond to this threat by either restricting access to U.S. universities or keeping our ideas in the United States is completely wrong. We’ll lose the tremendous advantage we have of an open university system if we do that. The only answer is for U.S. universities to do even more in pursuing their great record of being innovative and creative.

Q: Do you think it’s possible to maintain academic freedom of information in the context of dealing with people who may not share our commitment to protecting intellectual property?

A: In such a situation, we need to recognize that we will have some losses. But there will be more severe effects on our innovative enterprise, which is the best in the world, if we start trying to stop these losses by applying restrictions. Universities aren’t very good, first of all, at assessing the nature of the risk [of intellectual-property loss] and, second, at deciding what restrictive measures should be put in place. So, both my co-author Condi and I believe, keep the system open. Recognize that you will have some losses, but do what you do well.

Universities should make sure that our scholarly efforts and our educational efforts permit advances in key areas where fundamental research and practical application come together, in health, energy, and environment, including an emphasis on innovation. And we see that happening. By the way, much as the Chinese universities are improving, they do not have the kind of ecosystem that is so strong here, in terms of promoting innovation, creativity, and getting important things implemented in the private sector.

Q:  So are there specific measures that universities should be taking to address these efforts to exploit U.S. innovations, or is your advice that they should avoid taking any special measures?

A: My answer is no, there are not specific measures they should take, but it is very important that the administrative leadership of the university understands the concerns in Washington, appreciates the risks, and doesn’t enter into joint projects that could really lead to a loss of sensitive technology.

The universities should try and explain to the government that we think the proper response here is better performance by U.S. universities, rather than trying to keep people out or keep our ideas in.

I think one should expect that the technical competence of China will continue to improve, because of the capabilities of its people and the significant amount of resources the Chinese are putting into technology leadership in a variety of fields. We should expect that. How much of an advantage is given to China by their quite sustained illegal efforts to acquire technology from both the United States and Europe? I think it is helpful but by no means the most important or the determining factor in their advance.

This short piece with Condi Rice is not so much directed to U.S. universities; rather it is directed to the government and the national security community, to say to them, be cautious here — don’t throw the baby out with the bathwater.