Nanograins make for a seismic shift

In Earth’s crust, tectonic blocks slide and grind past each other like enormous ships loosed from anchor. Earthquakes are generated along these fault zones when enough pressure builds for a block to stick, then suddenly slip.

These slips can be caused by several factors that reduce friction within a fault zone, such as hotter temperatures or vented gases that separate blocks like pucks on an air-hockey table. The decreasing friction enables one tectonic block to accelerate against the other until it runs out of energy. Seismologists have long believed this kind of frictional instability can explain how all crustal earthquakes start. But that might not be the whole story.

In a study published today in Nature Communications, scientists Matej Pec and Hongyu Sun, from MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS), find that ultra-fine-grained crystals within fault zones can behave like low-viscosity fluids. The finding offers an alternative explanation for the instability that leads to crustal earthquakes. It also suggests a link between quakes in the crust and other types of temblors that occur deep in the Earth.

Nanograins are commonly found in rocks from seismic environments along the smooth surface of “fault mirrors.” These polished, reflective rock faces betray the slipping, sliding forces of past earthquakes. However, it was unclear whether the crystals caused quakes or were merely formed by them.

To better characterize how these crystals behaved within a fault, the researchers used a planetary ball milling machine to pulverize granite rocks into particles resembling those found in nature. Like a super-powered washing machine filled with steel balls, the machine pounded the rock until all its crystals were about 100 nanometers in width, each grain 1/2,000 the size of an average grain of sand.

After packing the earthquake crystals into postage-stamp sized wafers lined with gold, the researchers then subjected the material to stresses and heat, creating laboratory miniatures of real fault zones. This process enabled them to isolate the effect of the crystals from the complexity of other factors involved in an actual earthquake.

The researchers report that the crystals were extremely weak when shearing was initiated — an order of magnitude weaker than more common microcrystals. But the nanocrystals became stronger with more friction. Pec, professor of geophysics and the Victor P. Starr Career Development Chair, compares this characteristic, called “rate-strengthening,” to stirring honey in a jar. Stirring the honey slowly is easy, but becomes more difficult the faster you stir.

The experiment suggests something similar happens in fault zones. As tectonic blocks accelerate past each other, the crystals gum things up between them like honey stirred in a seismic pot.

Sun, the study’s lead author and EAPS graduate student, explains that their finding runs counter to the dominant frictional weakening theory of how earthquakes start. That theory would predict surfaces of a fault zone have material that gets weaker as the fault block slides and friction increases. The nanocrystals did just the opposite. However, the crystal’s intrinsic weakness could mean that when enough of them accumulate within a fault, they can give way, causing an earthquake.

“We don’t totally disagree with the old theorem, but our study really opens new doors to explain the mechanisms of how earthquakes happen in the crust,” Sun says.

The finding also suggests a previously unrecognized link between earthquakes in the crust and the earthquakes that rumble hundreds of kilometers beneath the surface, where the same tectonic dynamics aren’t at play. That deep, there are no tectonic blocks to grind against each other, and even if there were, the immense pressure would prevent the strike-slip quakes observed in the crust.

“We know that earthquakes happen all the way down to really big depths where this motion along a frictional fault is basically impossible,” says Pec. “And so clearly, there must be different processes that allow for these earthquakes to happen.”

Possible mechanisms for these deep Earth tremors include interactions between mineral volumes at different phases and other kinds of metamorphic reactions, such as cavitation, in which fluid pumped through pores destabilizes a fault. These mechanisms are all characterized by a weak, rate-strengthening layer.

If weak, rate-strengthening nanocrystals are abundant in the deep Earth, they could present another possible mechanism, says Pec. “Maybe crustal earthquakes are not a completely different beast than the deeper earthquakes. Maybe they have something in common.”

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Getting quantum dots to stop blinking

Quantum dots, discovered in the 1990s, have a wide range of applications and are perhaps best known for producing vivid colors in some high-end televisions. But for some potential uses, such as tracking biochemical pathways of a drug as it interacts with living cells, progress has been hampered by one seemingly uncontrollable characteristic: a tendency to blink off at random intervals. That doesn’t matter when the dots are used in the aggregate, as in TV screens, but for precision applications it can be a significant drawback.

Now, a team of chemists at MIT has come up with a way to control this unwanted blinking without requiring any modification to the formulation or the manufacturing process. By firing a beam of mid-infrared laser light for an infinitesimal moment — a few trillionths of a second — the quantum dot’s blinking is eliminated for a relatively long period, tens of billions of times longer than the laser pulse.

The new technique is described in a paper appearing today in the journal Nature Nanotechnology, by doctoral students Jiaojian Shi, Weiwei Sun, and Hendrik Utzat, professors of chemistry Keith Nelson and Moungi Bawendi, and five others at MIT.

Quantum dots are tiny particles, just a few nanometers across, made of semiconductor material, which has a “bandgap” between the energy levels of its electrons. When such materials gain energy from light shining on them, electrons can jump to a higher energy band; when they revert to their previous level, energy is released in the form of a photon, a particle of light. The frequency of this light, which determines its color, can be precisely tuned by selecting the shapes and dimensions of the dots. Besides display screens, quantum dots have potential for uses as solar cells, transistors, lasers, and quantum information devices.

The blinking phenomenon was first observed in the 1990s, soon after quantum dots were first made. “From that time on,” Bawendi says, “I would give presentations [about quantum dots], and people would say, ‘just make this go away!’ So, a lot of effort went into trying to eliminate it by engineering the interface between the dot and its environment, or by adding other molecules. But none of these things really worked well or were very reproducible.”

“We know that for some quantum information applications, we want a perfect single-photon emitter source,” Sun explains. But with currently available quantum dots, which otherwise might be well-suited to such applications, “they will turn on off randomly, and this is actually detrimental for any of the applications that utilize the photoluminescence from the dots.”

But now, she says, thanks to the team’s research, “we use these ultra-fast mid-infrared pulses, and the quantum dots can stay in the ‘on’ state. This can potentially be very useful for applications, like in quantum information science, where you really need a bright source of single photons without any intermittency.”

Similarly, for biomedical research applications, eliminating the blinking is essential, Shi says. “There are many biological processes that really require visualization with a steady photoluminescent tag, like tracking applications. For example, when we take medicines, you want to visualize how those drug molecules are being internalized in the cell, and where in the subcellular organelles it ends up.” This could lead to more efficient drug-discovery processes, he says, “but if the quantum dots start blinking a lot, you basically lose track of where the molecule is.”

Nelson, who is the Haslam and Dewey Professor of Chemistry, explains that the cause of the blinking phenomenon probably has to do with extra electrical charges, such as extra electrons, attaching to the outer part of the quantum dots, altering the surface properties so that there are other alternative pathways for the extra energy to be released instead of by emitting light.

“Various things can happen in a real environment,” Nelson says, “such that perhaps the quantum dot has an electron glommed onto it somewhere at the surface.” Instead of being electrically neutral, the quantum dot now has a net charge, and while it can still return to its ground state by emitting a photon, “the extra charge unfortunately also opens up a whole bunch of additional pathways for the electron’s excited state to return to the ground state without emitting a photon,” for example by shedding heat instead.

But when zapped with a burst of mid-infrared light, the extra charges tend to get knocked off the surface, allowing the quantum dots to produce stable emissions and stop their blinking.

It turns out, Utzat says, that this is “a very general process,” which might turn out to be useful for dealing with anomalous intermittency in some other devices, such as in so-called nitrogen vacancy centers in diamond, which are being harnessed for ultra-high-resolution microscopy and as sources of single-photons in optical quantum technologies. “Even though we have shown it for only one kind of workhorse material, the quantum dot, I believe that we can apply this method to other emitters,” he says. “I think the fundamental effect of using this mid-infrared light is applicable to a wide variety of different materials.”

Nelson says the effect also may not be limited to the mid-infrared pulses, which currently rely on bulky and expensive laboratory laser equipment and are not yet ready for commercial applications. The same principle could also extend to terahertz frequencies, he says, an area that has been under development in his lab and others and that in principle could lead to much smaller and less expensive devices.

The research team also included Ardavan Farahvash, Frank Gao, Zhuquan Zhang, Ulugbek Barotov, and Adam Willard, all at MIT. The work was supported by the U.S. Army Research Lab and the U.S. Army Research Office through the Institute for Soldier Nanotechnologies, the U.S. Department of Energy, and the Samsung Global Outreach Program.

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In MIT visit, Dropbox CEO Drew Houston ’05 explores the accelerated shift to distributed work

When the cloud storage firm Dropbox decided to shut down its offices with the outbreak of the Covid-19 pandemic, co-founder and CEO Drew Houston ’05 had to send the company’s nearly 3,000 employees home and tell them they were not coming back to work anytime soon. “It felt like I was announcing a snow day or something.”

In the early days of the pandemic, Houston says that Dropbox reacted as many others did to ensure that employees were safe and customers were taken care of. “It’s surreal, there’s no playbook for running a global company in a pandemic over Zoom. For a lot of it we were just taking it as we go.”

Houston talked about his experience leading Dropbox through a public health crisis and how Covid-19 has accelerated a shift to distributed work in a fireside chat on Oct. 14 with Dan Huttenlocher, dean of the MIT Stephen A. Schwarzman College of Computing.

During the discussion, Houston also spoke about his $10 million gift to MIT, which will endow the first shared professorship between the MIT Schwarzman College of Computing and the MIT Sloan School of Management, as well as provide a catalyst startup fund for the college.

“The goal is to find ways to unlock more of our brainpower through a multidisciplinary approach between computing and management,” says Houston. "It's often at the intersection of these disciplines where you can bring people together from different perspectives, where you can have really big unlocks. I think academia has a huge role to play [here], and I think MIT is super well-positioned to lead. So, I want to do anything I can to help with that."

Virtual first

While the abrupt swing to remote work was unexpected, Houston says it was pretty clear that the entire way of working as we knew it was going to change indefinitely for knowledge workers. “There’s a silver lining in every crisis,” says Houston, noting that people have been using Dropbox for years to work more flexibly so it made sense for the company to lean in and become early adopters of a distributed work paradigm in which employees work in different physical locations.

Dropbox proceeded to redesign the work experience throughout the company, unveiling a “virtual first” working model in October 2020 in which remote work is the primary experience for all employees. Individual work spaces went by the wayside and offices located in areas with a high concentration of employees were converted into convening and collaborative spaces called Dropbox Studios for in-person work with teammates.

“There’s a lot we could say about Covid, but for me, the most significant thing is that we’ll look back at 2020 as the year we shifted permanently from working out of offices to primarily working out of screens. It’s a transition that’s been underway for a while, but Covid completely finished the swing,” says Houston.

Designing for the future workplace

Houston says the pandemic also prompted Dropbox to reevaluate its product line and begin thinking of ways to make improvements. “We’ve had this whole new way of working sort of forced on us. No one designed it; it just happened. Even tools like Zoom, Slack, and Dropbox were designed in and for the old world.”

Undergoing that process helped Dropbox gain clarity on where they could add value and led to the realization that they needed to get back to their roots. “In a lot of ways, what people need today in principle is the same thing they needed in the beginning — one place for all their stuff,” says Houston.

Dropbox reoriented its product roadmap to refocus efforts from syncing files to organizing cloud content. The company is focused on building toward this new direction with the release of new automation features that users can easily implement to better organize their uploaded content and find it quickly. Dropbox also recently announced the acquisition of Command E, a universal search and productivity company, to help accelerate its efforts in this space.

Houston views Dropbox as still evolving and sees many opportunities ahead in this new era of distributed work. “We need to design better tools and smarter systems. It’s not just the individual parts, but how they’re woven together.” He’s surprised by how little intelligence is actually integrated into current systems and believes that rapid advances in AI and machine learning will soon lead to a new generation of smart tools that will ultimately reshape the nature of work — “in the same way that we had a new generation of cloud tools revolutionize how we work and had all these advantages that we couldn’t imagine not having now.”

Founding roots

Houston famously turned his frustration with carrying USB drives and emailing files to himself into a demo for what became Dropbox.

After graduating from MIT in 2005 with a bachelor’s degree in electrical engineering and computer science, he teamed up with fellow classmate Arash Ferdowsi to found Dropbox in 2007 and led the company’s growth from a simple idea to a service used by 700 million people around the world today.

Houston credits MIT for preparing him well for his entrepreneurial journey, recalling that what surprised him most about his student experience was how much he learned outside the classroom. At the event, he stressed the importance of developing both sides of the brain to a select group of computer science and management students who were in attendance, and a broader live stream audience. “One thing you learn about starting a company is that the hardest problems are usually not technical problems; they’re people problems.” He says that he didn’t realize it at the time, but some of his first lessons in management were gained by taking on responsibilities in his fraternity and in various student organizations that evoked a sense of being “on the hook.”

As CEO, Houston has had a chance to look behind the curtain at how things happen and has come to appreciate that problems don’t solve themselves. While individual people can make a huge difference, he explains that many of the challenges the world faces right now are inherently multidisciplinary ones, which sparked his interest in the MIT Schwarzman College of Computing.

He says that the mindset embodied by the college to connect computing with other disciplines resonated and inspired him to initiate his biggest philanthropic effort to date sooner rather than later because “we don’t have that much time to address these problems.”

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New 10-minute test detects Covid-19 immunity

Researchers have successfully developed a rapid point-of-care test for the detection of SARS-CoV-2 neutralizing antibodies (NAbs). This simple test, only requiring a drop of blood from a fingertip, can be performed within 10 minutes without the need for a laboratory or specially trained personnel. Currently, no similar NAb tests are commercially available within Singapore or elsewhere.

The work was led by the Antimicrobial Resistance (AMR) interdisciplinary research group at Singapore-MIT Alliance for Research and Technology (SMART) and the Nanyang Technological University, Singapore (NTU Singapore), alongside collaborators at National University Hospital, MIT, and the Centre for Life Sciences and Yong Loo Lin School of Medicine at National University of Singapore.

To curb the transmission of SARS-CoV-2, countries have imposed strict measures to minimize social interaction and cross-border movements. Despite being able to improve surveillance and prevent spread to some extent, these measures have severely impacted economies and livelihoods, and the path toward regaining normalcy involves achieving herd immunity against the virus, either naturally or through mass vaccination. To evaluate herd immunity and the effectiveness of vaccine immunization programs, it is essential to screen populations for the presence of SARS-CoV-2 NAbs on a faster and larger scale.

As part of a body’s natural immune response, NAbs are generated by either exposure to the virus or a vaccine. For effective prevention of viral infections, NAbs must be generated in sufficient quantities. The number of NAbs present in individuals indicate if they possess protective immunity to the virus and their probability of experiencing severe outcomes should they be infected. NAb testing can determine whether vaccinated individuals should be considered for booster shots for additional protection against the virus.

Despite the availability of various Covid-19 diagnostic tests, the detection of SARs-CoV-2 NAbs is still generally conducted at hospitals and specialized diagnostic laboratories. Currently, NAbs are commonly detected using virus neutralization tests, which require handling of live virus, a facility with rigorous biosafety and containment precautions, skilled personnel, and two to four days of processing time. Thus, these tests are not viable for large population testing and surveillance due to the lengthy process that may put a strain on existing laboratory capabilities. Developing a more efficient means of testing better allows for immediate point-of-care testing and mass monitoring for events or workplaces, specific localities, high-traffic points, and critical points of entry such as immigration checkpoints.

“With the gradual opening up of borders, economies, and society, having the right test and information will be crucial to not only plan for this future, but also ensure that it can be done safely without hampering current efforts to curb the spread of the virus,” says Megan McBee, MIT research affiliate and scientific director at SMART AMR. 

According to the research team’s data, which has been published in Nature Communications Medicine, the newly developed rapid cellulose pull-down viral neutralization test (cpVNT) detects SARS-CoV-2 NAbs in plasma samples within 10 minutes, utilizing a vertical flow paper-based assay format and protein engineering technology developed at SMART AMR and the lab of Associate Professor Hadley D. Sikes in the MIT Department of Chemical Engineering. This same protein engineering technology has also been used to develop tests to detect other well-known viruses, such as the Zika virus and tuberculosis. Cellulose was adopted as a test material as it is cost-effective and easily manufactured, and to avoid reliance on nitrocellulose, which is in high demand due to its use in other rapid Covid-19 tests.

The developed test is simple to administer, non-invasive, and offers quick results. To perform the test, a user mixes a drop of fingertip blood with the reaction solutions and places it on a paper strip, before inserting it into a portable reader device that will detect the NAb signals and reflect the results. This test offers up to 93 percent accuracy, higher than similar lab-based methods currently being used. 

“Schools and workplaces will also benefit greatly from the test. Whether a person should be considered for receiving a booster vaccine can also be evaluated with this quick test, as the results are available within minutes from a fingertip blood sample. And, if we are able to quickly determine immunity on a larger scale, the review and relaxing of Covid-related measures can be done in a more controlled, data-driven manner,” says Sikes, who is also a principal investigator at SMART AMR and a co-corresponding author of the paper. 

Co-corresponding author Professor Peter Preiser, a co-lead principal investigator at SMART AMR and the associate vice president for biomedical and life sciences at NTU Singapore, says “Besides detecting immunity to the current vaccine version of SARS-CoV-2 virus, the NAb test can be modified to monitor immunity against the other variants of the virus. This can provide information on the potential efficacy of different vaccines against each variant, or whether one should travel to areas that may have a high incidence of a specific variant.”

Further development of the test is underway for its approval by regulatory authorities and manufacturing for public use. The team that has developed the tests at SMART has also spun off a biotech startup, Thrixen, that is developing the test into a commercially ready product.

Key development of the rapid test was done at SMART AMR and NTU’s School of Biological Sciences. The research carried out at SMART is supported by the National Research Foundation (NRF) Singapore under its Campus for Research Excellence And Technological Enterprise (CREATE) program. The work was also supported by the National Medical Research Council under its Covid-19 Research Fund, and National Health Innovation Centre under its Covid-19 Gap funding grant.

SMART is MIT’s research enterprise in Singapore, established by the NRF in 2007. SMART is the first entity in CREATE developed by the NRF. SMART serves as an intellectual and innovation hub for research interactions between MIT and Singapore, undertaking cutting-edge research projects in areas of interest to both Singapore and MIT. SMART currently comprises an Innovation Centre and five interdisciplinary research groups: AMR, Critical Analytics for Manufacturing Personalized-Medicine, Disruptive and Sustainable Technologies for Agricultural Precision, Future Urban Mobility, and Low Energy Electronic Systems.

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

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Adedolapo Adedokun named 2023 Mitchell Scholar

MIT senior Adedolapo “Dolapo” Adedokun has been named one of 12 winners of the George J. Mitchell Scholarship’s Class of 2023. After completing his degree in electrical engineering and computer science next spring, he will travel to Ireland to undertake a MSc in intelligent systems at Trinity College Dublin as MIT’s fourth student to receive this award.

Mitchell Scholars are selected on the basis of academic achievement, leadership, and dedication to public service. The scholarship is named in honor of U.S. Senator Mitchell’s contributions to the Northern Ireland peace process. This year, over 450 American students applied for the prestigious fellowship, which is sponsored by the U.S.-Ireland Alliance and funds a year of graduate studies in Ireland.

Adedokun was raised in East Brunswick, New Jersey, and is the son of Nigerian immigrants. His goal is to become a technologist who builds platforms for artistic expression that can be used to democratize musical education.

Adedokun was supported in the application process by MIT’s Distinguished Fellowships team in Career Advising and Professional Development, and the Presidential Committee on Distinguished Fellowships. Mark Brennan PhD ’20, a member of the Presidential Committee for Distinguished Fellowships, says, “Dolapo is at the frontier of ensuring equitable access to arts education, one of the most important yet unevenly available aspects of the American school system. With a passion for jazz and extensive commercial technology development experience, he has all the pieces in place to spur technology-supported arts education in American schools.”

As a computer scientist and jazz instrumentalist, Adedokun wants to use the power of technology and music to foster connections between people, enabling all communities to have a voice in expressing themselves artistically. He is also motivated by his observations of the inequities of broadband access, particularly for communities of color, and wishes to contribute to innovations in this arena to ensure that all students, regardless of their backgrounds or circumstances, have access to internet infrastructure to achieve educationally.

It was after taking both 6.033 (Computer System Engineering) and 21M.080 (Music Technology) that Adedokun was inspired to invent a smart-home system that allowed users to anonymously layer different melodies as they entered and left a building, which created a unique and rich soundtrack for each day. Adedokun wants to develop in tandem his talents in music and computer science, perhaps by using the field of network latency to allow musical collaboration that defies the limitations of geographic boundaries.

Adedokun has brought his passion for leadership to many MIT organizations. In his sophomore year, Adedokun was elected president of the MIT Chapter of the National Society of Black Engineers, spearheading an initiative to create 10 new corporate relationships to increase minority participation in STEM fields and the technology industry. Within his computer science department, he was one of 10 students selected for the Undergraduate Student Advisory Group in EECS (USAGE). Subjects that Adedokun has tackled include advising on the structure of introductory courses, promoting new AI curricula and pre-orientation program for incoming first-year students, and improving teaching assistant training. Adedokun serves on the board of directors for the Harvard/MIT Cooperative Society, America’s oldest college cooperative. Adedokun credits his membership in Chocolate City, an MIT living group, as a force to ground him and provide him the pivotal support he needed at MIT.

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The reasons behind lithium-ion batteries’ rapid cost decline

Lithium-ion batteries, those marvels of lightweight power that have made possible today’s age of handheld electronics and electric vehicles, have plunged in cost since their introduction three decades ago at a rate similar to the drop in solar panel prices, as documented by a study published last March. But what brought about such an astonishing cost decline, of about 97 percent?

Some of the researchers behind that earlier study have now analyzed what accounted for the extraordinary savings. They found that by far the biggest factor was work on research and development, particularly in chemistry and materials science. This outweighed the gains achieved through economies of scale, though that turned out to be the second-largest category of reductions.

The new findings are being published today in the journal Energy and Environmental Science, in a paper by MIT postdoc Micah Ziegler, recent graduate student Juhyun Song PhD ’19, and Jessika Trancik, a professor in MIT’s Institute for Data, Systems and Society.

The findings could be useful for policymakers and planners to help guide spending priorities in order to continue the pathway toward ever-lower costs for this and other crucial energy storage technologies, according to Trancik. Their work suggests that there is still considerable room for further improvement in electrochemical battery technologies, she says.

The analysis required digging through a variety of sources, since much of the relevant information consists of closely held proprietary business data. “The data collection effort was extensive,” Ziegler says. “We looked at academic articles, industry and government reports, press releases, and specification sheets. We even looked at some legal filings that came out. We had to piece together data from many different sources to get a sense of what was happening.” He says they collected “about 15,000 qualitative and quantitative data points, across 1,000 individual records from approximately 280 references.”

Data from the earliest times are hardest to access and can have the greatest uncertainties, Trancik says, but by comparing different data sources from the same period they have attempted to account for these uncertainties.

Overall, she says, “we estimate that the majority of the cost decline, more than 50 percent, came from research-and-development-related activities.” That included both private sector and government-funded research and development, and “the vast majority” of that cost decline within that R&D category came from chemistry and materials research.

That was an interesting finding, she says, because “there were so many variables that people were working on through very different kinds of efforts,” including the design of the battery cells themselves, their manufacturing systems, supply chains, and so on. “The cost improvement emerged from a diverse set of efforts and many people, and not from the work of only a few individuals.”

The findings about the importance of investment in R&D were especially significant, Ziegler says, because much of this investment happened after lithium-ion battery technology was commercialized, a stage at which some analysts thought the research contribution would become less significant. Over roughly a 20-year period starting five years after the batteries’ introduction in the early 1990s, he says, “most of the cost reduction still came from R&D. The R&D contribution didn’t end when commercialization began. In fact, it was still the biggest contributor to cost reduction.”

The study took advantage of an analytical approach that Trancik and her team initially developed to analyze the similarly precipitous drop in costs of silicon solar panels over the last few decades. They also applied the approach to understand the rising costs of nuclear energy. “This is really getting at the fundamental mechanisms of technological change,” she says. “And we can also develop these models looking forward in time, which allows us to uncover the levers that people could use to improve the technology in the future.”

One advantage of the methodology Trancik and her colleagues have developed, she says, is that it helps to sort out the relative importance of different factors when many variables are changing all at once, which typically happens as a technology improves. “It’s not simply adding up the cost effects of these variables,” she says, “because many of these variables affect many different cost components. There’s this kind of intricate web of dependencies.” But the team’s methodology makes it possible to “look at how that overall cost change can be attributed to those variables, by essentially mapping out that network of dependencies,” she says.

This can help provide guidance on public spending, private investments, and other incentives. “What are all the things that different decision makers could do?” she asks. “What decisions do they have agency over so that they could improve the technology, which is important in the case of low-carbon technologies, where we’re looking for solutions to climate change and we have limited time and limited resources? The new approach allows us to potentially be a bit more intentional about where we make those investments of time and money.”

“This paper collects data available in a systematic way to determine changes in the cost components of lithium-ion batteries between 1990-1995 and 2010-2015,” says Laura Diaz Anadon, a professor of climate change policy at Cambridge University, who was not connected to this research. “This period was an important one in the history of the technology, and understanding the evolution of cost components lays the groundwork for future work on mechanisms and could help inform research efforts in other types of batteries.”

The research was supported by the Alfred P. Sloan Foundation, the Environmental Defense Fund, and the MIT Technology and Policy Program.

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Investigating pathogens and their life cycles, for the benefit of society

Desmond Edwards was a little kid when first learned about typhoid fever. Fortunately, he didn’t have the disease. He was looking at a cartoon public health announcement. The cartoon, produced by the Pan American Health Organization, was designed to educate people in his home country of Jamaica about the importance of immunizations for diseases like typhoid. The typhoid character in the cartoon was so unpleasant it gave him nightmares.

Edwards did have his fair share of hospital visits throughout his childhood. But, his own struggles with infection and illness, and those typhoid cartoon nightmares, became his inspiration for pursuing a career studying human disease. At age 6, Edwards was running impromptu baking soda experiments in repurposed glitter containers in his kitchen. Today, he is a senior at MIT, majoring in biology and biological engineering, thanks to a team of dedicated mentors and an insatiable curiosity about how the human body works — or, more accurately, how diseases stop it from working.

Finding a way into research

Edwards knew he wanted to do research but says he assumed that that was something you did after you got your degree. Imagine his surprise, then, upon arriving at MIT in 2018 and meeting classmates who not only had done research, but already had publications. Realizing that he could get a jump-start on his career, he sought out research opportunities and enrolled in the biology class 7.102 (Introduction to Molecular Biology Techniques) for his first-year Independent Activities Period. The class was specifically geared toward first-year students like him with no lab experience.

“It was a great first look at how research is done,” Edwards says of the class. Students took water samples from the Charles River and were expected to identify the strains of bacteria found in those samples using various biological techniques. They looked at the bacteria under a microscope. They examined how the samples metabolized different sources of carbon and determined if they could be stained by different dyes. They even got to try out basic genetic sequencing. “We knew where we were starting. And we knew the end goal,” says Edwards. The in-between was up to them.

Class 7.102 is taught by Mandana Sassanfar, a lecturer in biology and the department’s director of diversity and science outreach. For Sassanfar, the class is also an opportunity to find lab placements for students. In Edwards’ case, she literally led him to the lab of Assistant Professor Becky Lamason, walking up with him one evening to meet a postdoc, Jon McGinn, to talk about the lab and opportunities there. After Edwards expressed his interest to Lamason, she responded within 30 minutes. McGinn even followed up to answer any lingering questions.

“I think that was really what pushed it over the edge,” he says of his decision to take a position in the Lamason lab. “I saw that they were interested not only in having me as someone to help them do research, but also interested in my personal development.”

At the edges of cells and disciplines

The Lamason lab researches the life cycle of two different pathogens, trying to understand how the bacteria move between cells. Edwards has focused on Rickettsia parkeri, a tick-borne pathogen that’s responsible for causing spotted fever. This type of Rickettsia is what biologists call an obligate intracellular pathogen, meaning that it resides within cells and can only survive when it’s in a host. “I like to call it a glorified virus,” Edwards jokes.

Edwards gets excited describing the various ways in which R. parkeri can outsmart its infected host. It’s evolved to escape the phagosome of the cell, the small liquid sac that forms from the cell membrane and engulfs organisms like bacteria that pose a threat. Once it gets past the phagosome and enters the cell, it takes over cellular machinery, just like a virus. At this point of the life cycle, a bacterium will typically replicate so many times that the infected cell will burst, and the pathogen will spread widely. R. parkeri, though, can also spread to uninfected cells directly through the membrane where two cells touch. By not causing a cell to burst, the bacterium can spread without alerting the host to its presence.

“From a disease standpoint, that’s extremely interesting,” says Edwards. “If you’re not leaving the cell or being detected, you don’t see antibodies. You don’t see immune cells. It’s very hard to get that standard immune response.”

In his time in the lab, Edwards has worked on various projects related to Rickettsia, including developing genetic tools to study the pathogen and examining the potential genes that might be important in its life cycle. His projects sit at the intersection of biology and biological engineering.

“For me, I kind of live in between those spaces,” Edwards explains. “I am extremely interested in understanding the mechanisms that underlie all of biology. But I don’t only want to understand those systems. I also want to engineer them and apply them in ways that can be beneficial to society.”

Science for society

Last year, Edwards won the Whitehead Prize from the Department of Biology, recognizing students with “outstanding promise for a career in biological research.” But his extracurricular activities have been driven more by his desire to apply science for tangible social benefits.

“How do you take the science that you’ve done in the lab, in different research contexts, and translate that in a way that the public will actually benefit from it?” he asks.

Science education is particularly important for Edwards, given the educational opportunities he was given to help get to MIT. As a high schooler, Edwards participated in a Caribbean Science Foundation initiative called the Student Programme for Innovation in Science and Engineering. SPISE, as it’s known, is designed to encourage and support Caribbean students interested in careers in STEM fields. The program is modeled on the Minority Introduction to Engineering and Science program (MITES) at MIT. Cardinal Warde, a professor of electrical engineering, is himself from the Caribbean and serves as the faculty director for both MITES and SPISE.

“That experience not only kind of opened my eyes a bit more to what was available, what was in the realm of possibilities, but also provided support to get to MIT,” Edwards says of SPISE. For example, the program helped with college applications and worked with him to secure an internship at a biotech company when he first moved to the United States.

“If education falters, then you don’t replenish the field of science,” Edwards argues. “You don’t get younger generations excited, and the public won’t care.”

Edwards has also taken a leadership role in the MIT Biotechnology Group, a campus-wide student group meant to build connections between the MIT community and thought leaders in industry, business, and academia. For Edwards, the biotech and pharmaceutical industries play a clear role in disease treatment, and he knew he wanted to join the group before he even arrived at MIT. In 2019, he became co-director of the Biotech Group’s Industry Initiative, a program focused on preparing members for industry careers. In 2020, he became undergraduate president, and this year he’s co-president of the entire organization. Edwards speaks proudly of what the Biotech Group has accomplished during his tenure on the executive board, highlighting that they not only have the largest cohort ever this year, but it’s also the first time the group has been majority undergraduate.

Somehow, in between his research and outreach work, Edwards finds time to minor in French, play for the Quidditch team, and serve as co-president on the Course 20 Undergraduate Board, among other activities. It’s a balancing act that Edwards has mastered over his time at MIT because of his genuine excitement and interest in everything that he does.

“I don’t like not understanding things,” he jokes. “That applies to science, but it also extends to people.”

de MIT News https://ift.tt/3xalEac