Aurelia Butler

More stories

  • 113 Shares189 Views

    in Security

    Two first-year students named Rise Global Winners for 2022

    In 2019, former Google CEO Eric Schmidt and his wife, Wendy, launched a $1 billion philanthropic commitment to identify global talent. Part of that effort is the Rise initiative, which selects 100 young scholars, ages 15-17, from around the world who show unusual promise and a drive to serve others. This year’s cohort of 100 Rise Global Winners includes two MIT first-year students, Jacqueline Prawira and Safiya Sankari.

    Rise intentionally targets younger-aged students and focuses on identifying what the program terms “hidden brilliance” in any form, anywhere in the world, whether it be in a high school or a refugee camp. Another defining aspect of the program is that Rise winners receive sustained support — not just in secondary school, but throughout their lives.

    “We believe that the answers to the world’s toughest problems lie in the imagination of the world’s brightest minds,” says Eric Braverman, CEO of Schmidt Futures, which manages Rise along with the Rhodes Trust. “Rise is an integral part of our mission to create the best, largest, and most enduring pipeline of exceptional talent globally and match it to opportunities to serve others for life.”

    The Rise program creates this enduring pipeline by providing a lifetime of benefits, including funding, programming, and mentoring opportunities. These resources can be tailored to each person as they evolve throughout their career. In addition to a four-year college scholarship, winners receive mentoring and career services; networking opportunities with other Rise recipients and partner organizations; technical equipment such as laptops or tablets; courses on topics like leadership and human-centered design; and opportunities to apply for graduate scholarships and for funding throughout their careers to support their innovative ideas, such as grants or seed money to start a social enterprise.

    Prawira and Sankari’s winning service projects focus on global sustainability and global medical access, respectively. Prawira invented a way to use upcycled fish-scale waste to absorb heavy metals in wastewater. She first started experimenting with fish-scale waste in middle school to try to find a bio-based alternative to plastic. More recently, she discovered that the calcium salts and collagen in fish scales can absorb up to 82 percent of heavy metals from water, and 91 percent if an electric current is passed through the water. Her work has global implications for treating contaminated water at wastewater plants and in developing countries.

    Prawiri published her research in 2021 and has won awards from the U.S. Environmental Protection Agency and several other organizations. She’s planning to major in Course 3 (materials science and engineering), perhaps with an environmentally related minor. “I believe that sustainability and solving environmental problems requires a multifaced approach,” she says. “Creating greener materials for use in our daily lives will have a major impact in solving current environmental issues.”

    For Sankari’s service project, she developed an algorithm to analyze data from electronic nano-sensor devices, or e-noses, which can detect certain diseases from a patient’s breath. The devices are calibrated to detect volatile organic compound biosignatures that are indicative of diseases like diabetes and cancer. “E-nose disease detection is much faster and cheaper than traditional methods of diagnosis, making medical care more accessible to many,” she explains. The Python-based algorithm she created can translate raw data from e-noses into a result that the user can read.

    Sankari is a lifetime member of the American Junior Academy of Science and has been a finalist in several prestigious science competitions. She is considering a major in Course 6-7 (computer science and molecular biology) at MIT and hopes to continue to explore the intersection between nanotechnology and medicine.

    While the 2022 Rise recipients share a desire to tackle some of the world’s most intractable problems, their ideas and interests, as reflected by their service projects, are broad, innovative, and diverse. A winner from Belarus used bioinformatics to predict the molecular effect of a potential Alzheimer’s drug. A Romanian student created a magazine that aims to promote acceptance of transgender bodies. A Vietnamese teen created a prototype of a toothbrush that uses a nano chip to detect cancerous cells in saliva. And a recipient from the United States designed modular, tiny homes for the unhoused that are affordable and sustainable, as an alternative to homeless shelters.

    This year’s winners were selected from over 13,000 applicants from 47 countries, from Azerbaijan and Burkina Faso to Lebanon and Paraguay. The selection process includes group interviews, peer and expert review of each applicant’s service project, and formal talent assessments. More

  • 113 Shares149 Views

    in Environment

    “Drawing Together” is awarded Norman B. Leventhal City Prize

    “Drawing Together,” a social and ecological resilience project in New York City, has been awarded the 2022 Norman B. Leventhal City Prize. 

    The project is a collaboration between MIT faculty, researchers, and students, and Green City Force (GCF), a nonprofit organization in New York City that trains young people for careers with a sustainability focus while they serve local public housing communities.

    The winning proposal was submitted by a team led by MIT’s Miho Mazereeuw, associate professor and director of the Urban Risk Lab; Nicholas de Monchaux, professor and head of the Department of Architecture; Carlos Sandoval Olascoaga PhD ’21, a postdoc in the Department of Architecture and the MIT Schwarzman College of Computing; and Tonya Gayle, executive director of Green City Force.

    Through their Service Corps (affiliated with the national AmeriCorps service and training program), GCF trains young residents of New York City Housing Authority public housing to participate in large-scale environmental and health initiatives in public housing and other local communities.

    The Drawing Together team will collaborate with GCF on its “Eco-Hubs,” an urban farms initiative. In a co-design effort, Drawing Together will create a new digital platform to support community-led planning and design processes for the siting, design, and operation of these spaces. This platform will also facilitate the scaling-up of community engagement with Eco-Hubs.

    The $100,000 triennial prize was established in 2019 by MIT’s Norman B. Leventhal Center for Advanced Urbanism (LCAU) to catalyze innovative interdisciplinary urban design and planning approaches worldwide to improve the environment as well as the quality of life for residents. The first awardee was “Malden River Works for Waterfront Equity and Resilience,” a project for a civic waterfront space in Malden, Massachusetts.

    The 2022 Leventhal City Prize call for submissions sought proposals that focused on digital urbanism — investigating how life in cities can be improved using digital tools that are equitable and responsive to social and environmental conditions. The jury reviewed proposals for projects that offered new urban design and planning solutions using evolving data sources and computational techniques that transform the quality of life in metropolitan environments.

    “Digital urbanism is the intersection between cities, design, and technology and how we can identify new ways to include technology and design in our cities,” says LCAU Director Sarah Williams. “Drawing Together perfectly exemplifies how digital urbanism can assist in the co-development of design solution and improve the quality of life for the public.”

    The team will expand the workforce training currently offered by GCF to incorporate digital skills, with the goal of developing and integrating a sustainability-focused data science curriculum that supports sustainable urban farming within the Eco-Hubs.

    “What is most inspiring about this project is that young people are the writers, rather than passive subjects of urban transformation,” says juror Garrett Dash Nelson, president and head curator of the Norman B. Leventhal Map and Education Center at the Boston Public Library. “By taking the information and design architectures and making them central to youth-driven decisions about environmental planning, this project has the potential to activate a new participatory paradigm that will resonate far beyond New York City.”

    “In addition to community-based digital methods for urban environmental design, this project has the potential to strengthen computational skills in green job opportunities for youth that the Green City Force Eco-Hubs serve,” says juror James Wescoat, MIT Aga Khan Professor Emeritus of Landscape Architecture and Geography. 

    In addition to Nelson and Wescoat, the jury for this year’s competition included Lilian Coral, director of National Strategy and Technology Innovation at the Knight Foundation; Jose Castillo, principal at a|911 and professor of urbanism at CENTRO University; and Nigel Jacob, senior fellow at the Burnes Center for Global Impact at Northeastern University.

    The prize jury identified two finalists. Co-HATY Accelerator Team is a multidisciplinary project that helps provide housing and social support to Ukraine’s displaced residents. The team of urban planners, information technologists, architects, and sociologists are using digital technology to better connect residents across the country with housing opportunities. Team members include Brent D. Ryan, associate professor of urban design and public policy at MIT, and Anastasiya Ponomaryova, urban designer and co-founder of co-HATY.

    “The Ukraine’s team proposal makes a point of the relevance of architecture and planning in the context of humanitarian crises,” says Castillo. “It forces us to deploy techniques, methods, and knowledge to resolve issues ‘on demand.’ Different from a view of architecture and planning as ’slow practices,’ where design processes, research, pedagogies, and buildings take a long time to be deployed and finalized, this research shows an agile but thorough approach to the immediate and the contingent.”

    The second finalist is “Ozymandias: Using Artificial Intelligence to Map Urban Power Structures and Produce Fairer Results for All,” a project led by the Portland, Maine, Society for Architecture. The team behind this project seeks to encourage broader civic participation and positive change in municipal governments. By using emerging AI computation tools to illuminate patterns in power structures and decision-making, the team hopes to highlight correctable yet previously unrecognizable inequities. Principal investigator for the project is Jeff Levine, a lecturer in MIT’s Department of Urban Studies and Planning and a past director of planning and urban development for Portland.

    “The Ozymandias project recognizes an important truth about urban decision-making — that it is neither a bottom-up nor a top-down structure, but a tangled and often obscure network of formal and informal power systems,” says Nelson. “By bringing analytical methods to bear on a perennial question for civic action — who really governs in a democratic system? — the project offers a provocative methodology for examining why nominally participatory urban processes so often fail at producing inclusive and equitable outcomes.” More

  • 150 Shares109 Views

    in Security

    MIT student club Engineers Without Borders works with local village in Tanzania

    Four students from the MIT club Engineers Without Borders (EWB) spent part of their summer in Tanzania to begin assessment work for a health and sanitation project that will benefit the entire village, and an irrigated garden for the Mkutani Primary School.

    The club has been working with the Boston Professional Chapter of Engineers Without Borders (EWB-BPC) since 2019. The Boston chapter finds projects in underserved communities in the developing world and helped connect the MIT students with local government and school officials.

    Juniors Fiona Duong, female health and sanitation team lead, and Lai Wa Chu, irrigation team lead, spent two weeks over the summer in Mkutani conducting research for their projects. Chu was faced with finding more water supplies and a way to get water from the nearby river to the school to use in the gardens they were planting. Duong was charged with assessing the needs of the people who visit The Mkutani Dispensary, which serves as a local medical clinic. Juniors Hung Huynh, club president, and Vivian Cheng, student advisor, also made the trip to work on the projects.

    Health and sanitation project

    Duong looked into ways to help pregnant women with privacy issues as the facility they give birth in — The Mkutani Dispensary — is very small, with just two beds, and is in need of repairs and upgrades. Before leaving Cambridge, Duong led FaceTime meetings with government officials and facilities managers in the village. Once on the ground, she began collecting information and conducted focus groups with the local women and other constituents. She learned that one in three women were not giving birth in the dispensary due to privacy concerns and the lack of modern equipment needed for high-risk pregnancies.

    “The women said that the most pressing need there was water. The women were expected to bring their own water to their deliveries. The rain-catching system there was not enough to fulfill their needs and the river water wasn’t clean. When in labor, they relied on others to gather it and bring it to the dispensary by bike,” Duong says. “With broken windows, the dispensary did not allow for privacy or sanitary conditions.”

    Duong will also analyze the data she collected and share it with others before more MIT students head to Mkutani next summer.

    Farming, sustainability, and irrigation projectBefore heading to Mkutani, Chu conducted research regarding irrigation methods and water collection methods. She confirmed that the river water still contained E.coli and advised the teachers that it would need to be boiled or placed in the sun for a few hours before it could be used. Her technical background in fluid dynamics was helpful for the project.

    “We also found that there was a need for supplemental food for the school, as many children lived too far away to walk home for lunch. The headmaster reached out to us about building the garden, as the garden provides supplemental fruit and vegetables for many of the 600 students to eat. They needed water from the river that was quite far away from the school. We looked at ways to get the water to the garden,” Chu says.

    The group is considering conducting an ecological survey of the area to see if there is another source of water so they could drill another borehole. They will complete their analysis and then decide the best solution to implement.

    “Watching the whole team’s hard work pay off when the travel team got to Mkutani was so amazing,” says second-year student Maria Hernandez, club internal relations chair. “Now, we’re ready to get to work again so we can go back next year. I love being a part of Engineers Without Borders because it’s such a unique way to apply technical skills outside of the classroom and see the impact you make on the community. It’s a beautiful project that truly impacts so many people, and I can’t wait to go back to Mkutani next year.”

    Both Duong and Chu hope they’ll return to the school and the dispensary in summer 2023 to work on the implementation phase of their projects. “This project is one of the reasons I came to MIT. I wanted to work on a social impact project to help improve the world,” Chu says.

    “I hope to go back next summer and implement the project,” adds Duong. “If I do, we’ll go during the two most crucial weeks of the project — after the contractors have started the repair work on the dispensary, so we can see how things are going and then help with anything else related to the project.”

    Duong and Chu said students don’t have to be engineers to help with the EWB’s work — any MIT student interested in joining the club may do so. Both agree that fundraising is a priority, but there are numerous other roles students can help with.

    “MIT students shouldn’t be afraid to just dive right in. There’s a lot that needs to be done there, and even if you don’t have experience in a certain area, don’t let that be a barrier. It’s very rewarding work and it’s also great to get international work experience,” Duong says.

    Chu added, “The project may not seem flashy now, but the rewards are great. Students will get new technical skills and get to experience a new culture as well.” More

  • 88 Shares149 Views

    in Environment

    Studying floods to better predict their dangers

    “My job is basically flooding Cambridge,” says Katerina “Katya” Boukin, a graduate student in civil and environmental engineering at MIT and the MIT Concrete Sustainability Hub’s resident expert on flood simulations. 

    You can often find her fine-tuning high-resolution flood risk models for the City of Cambridge, Massachusetts, or talking about hurricanes with fellow researcher Ipek Bensu Manav.

    Flooding represents one of the world’s gravest natural hazards. Extreme climate events inducing flooding, like severe storms, winter storms, and tropical cyclones, caused an estimated $128.1 billion of damages in 2021 alone. 

    Climate simulation models suggest that severe storms will become more frequent in the coming years, necessitating a better understanding of which parts of cities are most vulnerable — an understanding that can be improved through modeling.

    A problem with current flood models is that they struggle to account for an oft-misunderstood type of flooding known as pluvial flooding. 

    “You might think of flooding as the overflowing of a body of water, like a river. This is fluvial flooding. This can be somewhat predictable, as you can think of proximity to water as a risk factor,” Boukin explains.

    However, the “flash flooding” that causes many deaths each year can happen even in places nowhere near a body of water. This is an example of pluvial flooding, which is affected by terrain, urban infrastructure, and the dynamic nature of storm loads.

    “If we don’t know how a flood is propagating, we don’t know the risk it poses to the urban environment. And if we don’t understand the risk, we can’t really discuss mitigation strategies,” says Boukin, “That’s why I pursue improving flood propagation models.”

    Boukin is leading development of a new flood prediction method that seeks to address these shortcomings. By better representing the complex morphology of cities, Boukin’s approach may provide a clearer forecast of future urban flooding.

    Katya Boukin developed this model of the City of Cambridge, Massachusetts. The base model was provided through a collaboration between MIT, the City of Cambridge, and Dewberry Engineering.

    Image: Katya Boukin

    Previous item
    Next item

    “In contrast to the more typical traditional catchment model, our method has rainwater spread around the urban environment based on the city’s topography, below-the-surface features like sewer pipes, and the characteristics of local soils,” notes Boukin.

    “We can simulate the flooding of regions with local rain forecasts. Our results can show how flooding propagates by the foot and by the second,” she adds.

    While Boukin’s current focus is flood simulation, her unconventional academic career has taken her research in many directions, like examining structural bottlenecks in dense urban rail systems and forecasting ground displacement due to tunneling. 

    “I’ve always been interested in the messy side of problem-solving. I think that difficult problems present a real chance to gain a deeper understanding,” says Boukin.

    Boukin credits her upbringing for giving her this perspective. A native of Israel, Boukin says that civil engineering is the family business. “My parents are civil engineers, my mom’s parents are, too, her grandfather was a professor in civil engineering, and so on. Civil engineering is my bloodline.”

    However, the decision to follow the family tradition did not come so easily. “After I took the Israeli equivalent of the SAT, I was at a decision point: Should I go to engineering school or medical school?” she recalls.

    “I decided to go on a backpacking trip to help make up my mind. It’s sort of an Israeli rite to explore internationally, so I spent six months in South America. I think backpacking is something everyone should do.”

    After this soul searching, Boukin landed on engineering school, where she fell in love with structural engineering. “It was the option that felt most familiar and interesting. I grew up playing with AutoCAD on the family computer, and now I use AutoCAD professionally!” she notes.

    “For my master’s degree, I was looking to study in a department that would help me integrate knowledge from fields like climatology and civil engineering. I found the MIT Department of Civil and Environmental Engineering to be an excellent fit,” she says.

    “I am lucky that MIT has so many people that work together as well as they do. I ended up at the Concrete Sustainability Hub, where I’m working on projects which are the perfect fit between what I wanted to do and what the department wanted to do.” 

    Boukin’s move to Cambridge has given her a new perspective on her family and childhood. 

    “My parents brought me to Israel when I was just 1 year old. In moving here as a second-time immigrant, I have a new perspective on what my parents went through during the move to Israel. I moved when I was 27 years old, the same age as they were. They didn’t have a support network and worked any job they could find,” she explains.

    “I am incredibly grateful to them for the morals they instilled in my sister, who recently graduated medical school, and I. I know I can call my parents if I ever need something, and they will do whatever they can to help.”

    Boukin hopes to honor her parents’ efforts through her research.

    “Not only do I want to help stakeholders understand flood risks, I want to make awareness of flooding more accessible. Each community needs different things to be resilient, and different cultures have different ways of delivering and receiving information,” she says.

    “Everyone should understand that they, in addition to the buildings and infrastructure around them, are part of a complex ecosystem. Any change to a city can affect the rest of it. If designers and residents are aware of this when considering flood mitigation strategies, we can better design cities and understand the consequences of damage.” More

  • 75 Shares139 Views

    in Environment

    MADMEC winner identifies sustainable greenhouse-cooling materials

    The winners of this year’s MADMEC competition identified a class of materials that could offer a more efficient way to keep greenhouses cool.

    After Covid-19 put the materials science competition on pause for two years, on Tuesday SmartClime, a team made up of three MIT graduate students, took home the first place, $10,000 prize.

    The team showed that a type of material that changes color in response to an electric voltage could reduce energy usage and save money if coated onto the panes of glass in greenhouses.

    “This project came out of our love of gardening,” said SmartClime team member and PhD candidate Isabella Caruso in the winning presentation. “Greenhouses let you grow things year-round, even in New England, but even greenhouse pros need to use heating furnaces in the winter and ventilation in the summer. All of that can be very labor- and energy-intensive.”

    Current options to keep greenhouses cool include traditional air conditioning units, venting and fans, and simple cloth. To develop a better solution, the team looked through scientific papers to find materials with the right climate control properties.

    Two classes of materials that looked promising were thermochromic coatings, which change color based on temperature, and electrochromic solutions, which change color based on electric voltage.

    Creating both the thermochromic and electrochromic solutions required the team to assemble nanoparticles and spin-coat them onto glass substrates. In lab tests, the electrochromic material performed well, turning a deep bluish hue to reduce the heat coming into the greenhouse while also letting in enough light for plants. Specifically, the electrochromic cell kept its test box about 1 to 3 degrees Celsius cooler than the test box coated in regular glass.

    The team estimated that greenhouse owners could make back the added costs of the electrochromic paneling through savings on other climate-control measures. Additional benefits of using the material include reducing heat-related crop losses, increasing crop yields, and reducing water requirements.

    Hosted by MIT’s Department of Materials Science and Engineering (DMSE), the competition was the culmination of team projects that began last spring and included a series of design challenges throughout the summer. Each team received guidance, access to equipment and labs, and up to $1,000 in funding to build and test their prototypes.

    “It’s great to be back and to have everyone here in person,” Mike Tarkanian, a senior lecturer in DMSE and coordinator of MADMEC, said at the event. “I’ve enjoyed getting back to normal, doing the design challenges over the summer and celebrating with everyone here today.”

    The second-place prize was split between YarnZ, which identified a nanofiber yarn that is more sustainable than traditional textile fibers, and WasteAway, which has developed a waste bin monitoring device that can identify the types of items thrown into trash and recycling bins and flag misplaced items.

    YarnZ (which stands for Yarns Are Really NanofiberZ), developed a nanofiber yarn that is more degradable than traditional microfiber yarns without sacrificing on performance.

    A large chunk of the waste and emissions in the clothing industry come from polyester, a slow-degrading polymer that requires an energy-intensive melt spinning process before it’s spun into the fibers of our clothes.

    “The biggest thing I want to impress upon you today is that the textile industry is a major greenhouse gas-producing entity and also produces a huge amount of waste,” YarnZ member and PhD candidate Natalie Mamrol said in the presentation.

    To replace polyester, the team developed a continuous process in which a type of nanofiber film collects in a water bath before being twisted into yarn. In subsequent tests, the nanofiber-based yarn degraded more quicky than traditional microfibers and showed comparable durability. YarnZ believes this early data should encourage others to explore nanofibers as a viable replacement in the clothing industry and to invest in scaling the approach for industrial settings.

    WasteAway’s system includes a camera that sits on top of trash bins and uses artificial intelligence to recognize items that people throw away.

    Of the 300 million tons of waste generated in the U.S. each year, more than half ends up in landfills. A lot of that waste could have been composted or recycled but was misplaced during disposal.

    “When someone throws something into the bin, our sensor detects the motion and captures an image,” explains WasteAway’s Melissa Stok, an undergraduate at MIT. “Those images are then processed by our machine-learning algorithm to find contamination.”

    Each device costs less than $30, and the team says that cost could go down as parts are bought at larger scales. The insights gleaned from the device could help waste management officials identify contaminated trash piles as well as inform education efforts by revealing common mistakes people make.

    Overall, Tarkanian believes the competition was a success not only because of the final results, but because of the experience the students got throughout the MADMEC program, which included several smaller, hands-on competitions involving laser cutters, 3-D printers, soldering irons, and other equipment many students said they had never used before.

    “They end up getting into the lab through these design challenges, which have them compete in various engineering tasks,” Tarkanian says. “It helps them get comfortable designing and prototyping, and they often end up using those tools in their research later.” More

  • 113 Shares169 Views

    in Environment

    3Q: Why Europe is so vulnerable to heat waves

    This year saw high-temperature records shattered across much of Europe, as crops withered in the fields due to widespread drought. Is this a harbinger of things to come as the Earth’s climate steadily warms up?

    Elfatih Eltahir, MIT professor of civil and environmental engineering and H. M. King Bhumibol Professor of Hydrology and Climate, and former doctoral student Alexandre Tuel PhD ’20 recently published a piece in the Bulletin of the Atomic Scientists describing how their research helps explain this anomalous European weather. The findings are based in part on analyses described in their book “Future Climate of the Mediterranean and Europe,” published earlier this year. MIT News asked the two authors to describe the dynamics behind these extreme weather events.

    Q: Was the European heat wave this summer anticipated based on existing climate models?

    Eltahir: Climate models project increasingly dry summers over Europe. This is especially true for the second half of the 21st century, and for southern Europe. Extreme dryness is often associated with hot conditions and heat waves, since any reduction in evaporation heats the soil and the air above it. In general, models agree in making such projections about European summers. However, understanding the physical mechanisms responsible for these projections is an active area of research.

    The same models that project dry summers over southern Europe also project dry winters over the neighboring Mediterranean Sea. In fact, the Mediterranean Sea stands out as one of the most significantly impacted regions — a literal “hot spot” — for winter droughts triggered by climate change. Again, until recently, the association between the projections of summer dryness over Europe and dry winters over the Mediterranean was not understood.

    In recent MIT doctoral research, carried out in the Department of Civil and Environmental Engineering, a hypothesis was developed to explain why the Mediterranean stands out as a hot spot for winter droughts under climate change. Further, the same theory offers a mechanistic understanding that connects the projections of dry summers over southern Europe and dry winters over the Mediterranean.

    What is exciting about the observed climate over Europe last summer is the fact that the observed drought started and developed with spatial and temporal patterns that are consistent with our proposed theory, and in particular the connection to the dry conditions observed over the Mediterranean during the previous winter.

    Q: What is it about the area around the Mediterranean basin that produces such unusual weather extremes?

    Eltahir: Multiple factors come together to cause extreme heat waves such as the one that Europe has experienced this summer, as well as previously, in 2003, 2015, 2018, 2019, and 2020. Among these, however, mutual influences between atmospheric dynamics and surface conditions, known as land-atmosphere feedbacks, seem to play a very important role.

    In the current climate, southern Europe is located in the transition zone between the dry subtropics (the Sahara Desert in North Africa) and the relatively wet midlatitudes (with a climate similar to that of the Pacific Northwest). High summertime temperatures tend to make the precipitation that falls to the ground evaporate quickly, and as a consequence soil moisture during summer is very dependent on springtime precipitation. A dry spring in Europe (such as the 2022 one) causes dry soils in late spring and early summer. This lack of surface water in turn limits surface evaporation during summer. Two important consequences follow: First, incoming radiative energy from the sun preferentially goes into increasing air temperature rather than evaporating water; and second, the inflow of water into air layers near the surface decreases, which makes the air drier and precipitation less likely. Combined, these two influences increase the likelihood of heat waves and droughts.

    Tuel: Through land-atmosphere feedbacks, dry springs provide a favorable environment for persistent warm and dry summers but are of course not enough to directly cause heat waves. A spark is required to ignite the fuel. In Europe and elsewhere, this spark is provided by large-scale atmospheric dynamics. If an anticyclone sets over an area with very dry soils, surface temperature can quickly shoot up as land-atmosphere feedbacks come into play, developing into a heat wave that can persist for weeks.

    The sensitivity to springtime precipitation makes southern Europe and the Mediterranean particularly prone to persistent summer heat waves. This will play an increasingly important role in the future, as spring precipitation is expected to decline, making scorching summers even more likely in this corner of the world. The decline in spring precipitation, which originates as an anomalously dry winter around the Mediterranean, is very robust across climate projections. Southern Europe and the Mediterranean really stand out from most other land areas, where precipitation will on average increase with global warming.

    In our work, we showed that this Mediterranean winter decline was driven by two independent factors: on the one hand, trends in the large-scale circulation, notably stationary atmospheric waves, and on the other hand, reduced warming of the Mediterranean Sea relative to the surrounding continents — a well-known feature of global warming. Both factors lead to increased surface air pressure and reduced precipitation over the Mediterranean and Southern Europe.

    Q: What can we expect over the coming decades in terms of the frequency and severity of these kinds of droughts, floods, and other extremes in European weather?

    Tuel: Climate models have long shown that the frequency and intensity of heat waves was bound to increase as the global climate warms, and Europe is no exception. The reason is simple: As the global temperature rises, the temperature distribution shifts toward higher values, and heat waves become more intense and more frequent. Southern Europe and the Mediterranean, however, will be hit particularly hard. The reason for this is related to the land-atmosphere feedbacks we just discussed. Winter precipitation over the Mediterranean and spring precipitation over southern Europe will decline significantly, which will lead to a decrease in early summer soil moisture over southern Europe and will push average summer temperatures even higher; the region will become a true climate change hot spot. In that sense, 2022 may really be a taste of the future. The succession of recent heat waves in Europe, however, suggests that things may be going faster than climate model projections imply. Decadal variability or badly understood trends in large-scale atmospheric dynamics may play a role here, though that is still debated. Another possibility is that climate models tend to underestimate the magnitude of land-atmosphere feedbacks and downplay the influence of dry soil moisture anomalies on summertime weather.

    Potential trends in floods are more difficult to assess because floods result from a multiplicity of factors, like extreme precipitation, soil moisture levels, or land cover. Extreme precipitation is generally expected to increase in most regions, but very high uncertainties remain, notably because extreme precipitation is highly dependent on atmospheric dynamics about which models do not always agree. What is almost certain is that with warming, the water content of the atmosphere increases (following a law of thermodynamics known as the Clausius-Clapeyron relationship). Thus, if the dynamics are favorable to precipitation, a lot more of it may fall in a warmer climate. Last year’s floods in Germany, for example, were triggered by unprecedented heavy rainfall which climate change made more likely. More

  • 88 Shares179 Views

    in Security

    Scientists chart how exercise affects the body

    Exercise is well-known to help people lose weight and avoid gaining it. However, identifying the cellular mechanisms that underlie this process has proven difficult because so many cells and tissues are involved.

    In a new study in mice that expands researchers’ understanding of how exercise and diet affect the body, MIT and Harvard Medical School researchers have mapped out many of the cells, genes, and cellular pathways that are modified by exercise or high-fat diet. The findings could offer potential targets for drugs that could help to enhance or mimic the benefits of exercise, the researchers say.

    “It is extremely important to understand the molecular mechanisms that are drivers of the beneficial effects of exercise and the detrimental effects of a high-fat diet, so that we can understand how we can intervene, and develop drugs that mimic the impact of exercise across multiple tissues,” says Manolis Kellis, a professor of computer science in MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and a member of the Broad Institute of MIT and Harvard.

    The researchers studied mice with high-fat or normal diets, who were either sedentary or given the opportunity to exercise whenever they wanted. Using single-cell RNA sequencing, the researchers cataloged the responses of 53 types of cells found in skeletal muscle and two types of fatty tissue.

    “One of the general points that we found in our study, which is overwhelmingly clear, is how high-fat diets push all of these cells and systems in one way, and exercise seems to be pushing them nearly all in the opposite way,” Kellis says. “It says that exercise can really have a major effect throughout the body.”

    Kellis and Laurie Goodyear, a professor of medicine at Harvard Medical School and senior investigator at the Joslin Diabetes Center, are the senior authors of the study, which appears today in the journal Cell Metabolism. Jiekun Yang, a research scientist in MIT CSAIL; Maria Vamvini, an instructor of medicine at the Joslin Diabetes Center; and Pasquale Nigro, an instructor of medicine at the Joslin Diabetes Center, are the lead authors of the paper.

    The risks of obesity

    Obesity is a growing health problem around the world. In the United States, more than 40 percent of the population is considered obese, and nearly 75 percent is overweight. Being overweight is a risk factor for many diseases, including heart disease, cancer, Alzheimer’s disease, and even infectious diseases such as Covid-19.

    “Obesity, along with aging, is a global factor that contributes to every aspect of human health,” Kellis says.

    Several years ago, his lab performed a study on the FTO gene region, which has been strongly linked to obesity risk. In that 2015 study, the research team found that genes in this region control a pathway that prompts immature fat cells called progenitor adipocytes to either become fat-burning cells or fat-storing cells.

    That finding, which demonstrated a clear genetic component to obesity, motivated Kellis to begin looking at how exercise, a well-known behavioral intervention that can prevent obesity, might act on progenitor adipocytes at the cellular level.

    To explore that question, Kellis and his colleagues decided to perform single-cell RNA sequencing of three types of tissue — skeletal muscle, visceral white adipose tissue (found packed around internal organs, where it stores fat), and subcutaneous white adipose tissue (which is found under the skin and primarily burns fat).

    These tissues came from mice from four different experimental groups. For three weeks, two groups of mice were fed either a normal diet or a high-fat diet. For the next three weeks, each of those two groups were further divided into a sedentary group and an exercise group, which had continuous access to a treadmill.

    By analyzing tissues from those mice, the researchers were able to comprehensively catalog the genes that were activated or suppressed by exercise in 53 different cell types.

    The researchers found that in all three tissue types, mesenchymal stem cells (MSCs) appeared to control many of the diet and exercise-induced effects that they observed. MSCs are stem cells that can differentiate into other cell types, including fat cells and fibroblasts. In adipose tissue, the researchers found that a high-fat diet modulated MSCs’ capacity to differentiate into fat-storing cells, while exercise reversed this effect.

    In addition to promoting fat storage, the researchers found that a high-fat diet also stimulated MSCs to secrete factors that remodel the extracellular matrix (ECM) — a network of proteins and other molecules that surround and support cells and tissues in the body. This ECM remodeling helps provide structure for enlarged fat-storing cells and also creates a more inflammatory environment.

    “As the adipocytes become overloaded with lipids, there’s an extreme amount of stress, and that causes low-grade inflammation, which is systemic and preserved for a long time,” Kellis says. “That is one of the factors that is contributing to many of the adverse effects of obesity.”

    Circadian effects

    The researchers also found that high-fat diets and exercise had opposing effects on cellular pathways that control circadian rhythms — the 24-hour cycles that govern many functions, from sleep to body temperature, hormone release, and digestion. The study revealed that exercise boosts the expression of genes that regulate these rhythms, while a high-fat diet suppresses them.

    “There have been a lot of studies showing that when you eat during the day is extremely important in how you absorb the calories,” Kellis says. “The circadian rhythm connection is a very important one, and shows how obesity and exercise are in fact directly impacting that circadian rhythm in peripheral organs, which could act systemically on distal clocks and regulate stem cell functions and immunity.”

    The researchers then compared their results to a database of human genes that have been linked with metabolic traits. They found that two of the circadian rhythm genes they identified in this study, known as DBP and CDKN1A, have genetic variants that have been associated with a higher risk of obesity in humans.

    “These results help us see the translational values of these targets, and how we could potentially target specific biological processes in specific cell types,” Yang says.

    The researchers are now analyzing samples of small intestine, liver, and brain tissue from the mice in this study, to explore the effects of exercise and high-fat diets on those tissues. They are also conducting work with human volunteers to sample blood and biopsies and study similarities and differences between human and mouse physiology. They hope that their findings will help guide drug developers in designing drugs that might mimic some of the beneficial effects of exercise.

    “The message for everyone should be, eat a healthy diet and exercise if possible,” Kellis says. “For those for whom this is not possible, due to low access to healthy foods, or due to disabilities or other factors that prevent exercise, or simply lack of time to have a healthy diet or a healthy lifestyle, what this study says is that we now have a better handle on the pathways, the specific genes, and the specific molecular and cellular processes that we should be manipulating therapeutically.”

    The research was funded by the National Institutes of Health and the Novo Nordisk Research Center in Seattle. More

  • 125 Shares99 Views

    in Environment

    Small eddies play a big role in feeding ocean microbes

    Subtropical gyres are enormous rotating ocean currents that generate sustained circulations in the Earth’s subtropical regions just to the north and south of the equator. These gyres are slow-moving whirlpools that circulate within massive basins around the world, gathering up nutrients, organisms, and sometimes trash, as the currents rotate from coast to coast.

    For years, oceanographers have puzzled over conflicting observations within subtropical gyres. At the surface, these massive currents appear to host healthy populations of phytoplankton — microbes that feed the rest of the ocean food chain and are responsible for sucking up a significant portion of the atmosphere’s carbon dioxide.

    But judging from what scientists know about the dynamics of gyres, they estimated the currents themselves wouldn’t be able to maintain enough nutrients to sustain the phytoplankton they were seeing. How, then, were the microbes able to thrive?

    Now, MIT researchers have found that phytoplankton may receive deliveries of nutrients from outside the gyres, and that the delivery vehicle is in the form of eddies — much smaller currents that swirl at the edges of a gyre. These eddies pull nutrients in from high-nutrient equatorial regions and push them into the center of a gyre, where the nutrients are then taken up by other currents and pumped to the surface to feed phytoplankton.

    Ocean eddies, the team found, appear to be an important source of nutrients in subtropical gyres. Their replenishing effect, which the researchers call a “nutrient relay,” helps maintain populations of phytoplankton, which play a central role in the ocean’s ability to sequester carbon from the atmosphere. While climate models tend to project a decline in the ocean’s ability to sequester carbon over the coming decades, this “nutrient relay” could help sustain carbon storage over the subtropical oceans.

    “There’s a lot of uncertainty about how the carbon cycle of the ocean will evolve as climate continues to change, ” says Mukund Gupta, a postdoc at Caltech who led the study as a graduate student at MIT. “As our paper shows, getting the carbon distribution right is not straightforward, and depends on understanding the role of eddies and other fine-scale motions in the ocean.”

    Gupta and his colleagues report their findings this week in the Proceedings of the National Academy of Sciences. The study’s co-authors are Jonathan Lauderdale, Oliver Jahn, Christopher Hill, Stephanie Dutkiewicz, and Michael Follows at MIT, and Richard Williams at the University of Liverpool.

    A snowy puzzle

    A cross-section of an ocean gyre resembles a stack of nesting bowls that is stratified by density: Warmer, lighter layers lie at the surface, while colder, denser waters make up deeper layers. Phytoplankton live within the ocean’s top sunlit layers, where the microbes require sunlight, warm temperatures, and nutrients to grow.

    When phytoplankton die, they sink through the ocean’s layers as “marine snow.” Some of this snow releases nutrients back into the current, where they are pumped back up to feed new microbes. The rest of the snow sinks out of the gyre, down to the deepest layers of the ocean. The deeper the snow sinks, the more difficult it is for it to be pumped back to the surface. The snow is then trapped, or sequestered, along with any unreleased carbon and nutrients.

    Oceanographers thought that the main source of nutrients in subtropical gyres came from recirculating marine snow. But as a portion of this snow inevitably sinks to the bottom, there must be another source of nutrients to explain the healthy populations of phytoplankton at the surface. Exactly what that source is “has left the oceanography community a little puzzled for some time,” Gupta says.

    Swirls at the edge

    In their new study, the team sought to simulate a subtropical gyre to see what other dynamics may be at work. They focused on the North Pacific gyre, one of the Earth’s five major gyres, which circulates over most of the North Pacific Ocean, and spans more than 20 million square kilometers. 

    The team started with the MITgcm, a general circulation model that simulates the physical circulation patterns in the atmosphere and oceans. To reproduce the North Pacific gyre’s dynamics as realistically as possible, the team used an MITgcm algorithm, previously developed at NASA and MIT, which tunes the model to match actual observations of the ocean, such as ocean currents recorded by satellites, and temperature and salinity measurements taken by ships and drifters.  

    “We use a simulation of the physical ocean that is as realistic as we can get, given the machinery of the model and the available observations,” Lauderdale says.

    Play video

    An animation of the North Pacific Ocean shows phosphate nutrient concentrations at 500 meters below the ocean surface. The swirls represent small eddies transporting phosphate from the nutrient-rich equator (lighter colors), northward toward the nutrient-depleted subtropics (darker colors). This nutrient relay mechanism helps sustain biological activity and carbon sequestration in the subtropical ocean. Credit: Oliver Jahn

    The realistic model captured finer details, at a resolution of less than 20 kilometers per pixel, compared to other models that have a more limited resolution. The team combined the simulation of the ocean’s physical behavior with the Darwin model — a simulation of microbe communities such as phytoplankton, and how they grow and evolve with ocean conditions.

    The team ran the combined simulation of the North Pacific gyre over a decade, and created animations to visualize the pattern of currents and the nutrients they carried, in and around the gyre. What emerged were small eddies that ran along the edges of the enormous gyre and appeared to be rich in nutrients.

    “We were picking up on little eddy motions, basically like weather systems in the ocean,” Lauderdale says. “These eddies were carrying packets of high-nutrient waters, from the equator, north into the center of the gyre and downwards along the sides of the bowls. We wondered if these eddy transfers made an important delivery mechanism.”

    Surprisingly, the nutrients first move deeper, away from the sunlight, before being returned upwards where the phytoplankton live. The team found that ocean eddies could supply up to 50 percent of the nutrients in subtropical gyres.

    “That is very significant,” Gupta says. “The vertical process that recycles nutrients from marine snow is only half the story. The other half is the replenishing effect of these eddies. As subtropical gyres contribute a significant part of the world’s oceans, we think this nutrient relay is of global importance.”

    This research was supported, in part, by the Simons Foundation and NASA. More