MIT Research News' Journal
[Most Recent Entries]
[Calendar View]
Thursday, September 25th, 2014
| Time |
Event |
| 12:00a |
Using science for service MIT senior Sofia Essayan-Perez, majoring in brain and cognitive sciences with a minor in applied international studies, has founded an educational nonprofit, conducted neuroscience research, and tutored MIT students. The common thread that binds these disparate interests: They all stem from hardships that those around her have faced.
Essayan-Perez was born in Boston, but spent her formative years moving among Chile, Nicaragua, the United States, and Canada, as her parents, both researchers in the social sciences, took on international projects. This diversity of experiences and environments has shaped Essayan-Perez’s nuanced view of the social disparities and scientific challenges she aims to tackle.
Using science for service
When she was just 12, Essayan-Perez was struck by the lack of infrastructure supporting math and science in Nicaragua, where some of her relatives lived. “I observed that rural schools lacked science books and lab equipment,” she says. “That really got to me, as someone who was fascinated by science at an early age.”
Today, Essayan-Perez frequently says that she “uses science for service.” She began by leading human biology workshops for girls in Nicaraguan villages; since arriving at MIT, she has worked with rural Nicaraguan high schools to strengthen math and science teaching, supported by fellowships from MIT’s Public Service Center. She has gone on to found Instrui, a nonprofit that offers open-source lesson plans and student-made educational videos in science and math to high schools in impoverished and developing countries. The lesson plans currently reach 3,500 students.
With Instrui, Essayan-Perez aims to make abstract subjects applicable to the daily lives of students. She believes that the key to opening the door to science, technology, engineering, and math (STEM) education in rural areas is considering the specific needs of students in such places. In Nicaragua, she hopes to create engaged learners who will eventually pursue medical and engineering careers in a country where only 5 percent of students currently pass university entrance exams in mathematics.
During one of her trips to Nicaragua, local health workers told Essayan-Perez that many students had gotten sick from contaminated water, sparking her idea of using community health risks as a basis for teaching math and science.
“When doctors tell the villagers to use a certain ratio of chlorine pellets in their water, that’s a tangible example of ratios,” Essayan-Perez says. “Examples like these became concrete ways of explaining math concepts, compared to rote memorization.”
The seven Nicaraguan villages she works in also have consistent issues with contamination of underground water supplies, largely due to shoddily constructed latrines. Essayan-Perez showed students how they could use what they learned in geometry to decrease their communities’ risks of water contamination.
“Health and education are often viewed as two totally disconnected things, but I don’t see it that way,” she says.
Innovative approach
In developing her approach to integrating STEM lesson-planning and relevant health problems, Essayan-Perez worked with mentor Alexander Slocum, the Neil and Jane Pappalardo Professor of Mechanical Engineering, beginning as a freshman.
“He really encouraged me to conduct fieldwork and shadow locals to understand what matters most to the communities where I work, and I think this was an important piece of advice,” Essayan-Perez says.
She also attributes this changed perspective to her minor in applied international studies and her coursework in anthropology, which have helped her understand social disparities.
Essayan-Perez hopes to build capacity in these rural villages. She has already seen local teachers and students implementing their own math and science lesson plans based on the approach she introduced, and would like to see this continue. She has also observed workers in health clinics collaborate with high schools to incorporate health education into the curriculum.
Relating to the brain
Back at MIT, Essayan-Perez approaches neuroscience research with a similar passion. She is interested in brain plasticity — the ability of neurons to rewire themselves, especially in the young brain. She studies how brain plasticity functions, or fails to function, in the brains of people with autism, which she sees as “an incredibly challenging social problem that we’re facing.”
Initially interested in biology more generally, brain and cognitive sciences piqued Essayan-Perez’ curiosity after a teacher recommended she compete in the Brain Bee, an annual international high school neuroscience competition: “Every topic I read kept pointing out how little we know about the brain,” she says.
While at MIT, she’s held an ongoing research position in the lab of Mark Bear, the Picower Professor of Neuroscience, in MIT’s Picower Institute for Learning and Memory. She has also conducted research at the University of California at Berkeley, and at the Institut Pasteur in Paris, under Thomas Bourgeron — a position she obtained through an MIT International Science and Technology Initiatives (MISTI) grant.
In Bear’s and Bourgeron’s labs, she honed her interest in the synaptic plasticity of autism. Her research not only focused on the genetic mutations correlated with autism, but also on how those mutations create differences in cell structure and brain anatomy.
“[Bourgeron’s lab was] working directly with a physician — a child psychiatrist — who would see the patients, and help gather patient data, but they also had researchers who were investigating at the bench-level what was going on,” Essayan-Perez says. “That translational approach, of using clinical and at the same time basic research tools, was really formative for me.”
In Bear’s lab, Essayan-Perez has been studying changes in neuron structure during brain plasticity, contributing to understanding the weakening of neural connections, and how this process is affected by autism. “The Bear lab’s approach of investigating basic science and applying it to address neurodevelopmental disorders has influenced my research goals,” Essayan-Perez says.
Her interest in neurological disorders has a familial basis: “Growing up with close family members facing the challenges of living with these disorders,” she says, “I wanted to understand how they could overcome them, and what could be done to solve other neurological disorders as well.”
Her drive to understand autism comes from the same instinct to help everyone reach his or her full potential.
Still more hours in the day
Outside of the lab and classroom and her international projects, Essayan-Perez teaches math and science on campus. She is a teaching assistant for calculus in MIT’s Experimental Studies Group and tutors in the Office of Minority Education and biology department. She also enjoys opera and Latin dance, with particular interests in bachata, salsa, and also folkloric Nicaraguan dance — which, she admits, is “hard to find in North America.”
Essayan-Perez hopes to become a physician-scientist, combining clinical work and research to innovate diagnosis and therapeutic alternatives for neurological disorders. “I’d like to continue integrating health and education,” she says. “It underlies everything that I do, and that’s something I’m going to continue and expand.” | | 12:41p |
How to make stronger, “greener” cement Concrete is the world’s most-used construction material, and a leading contributor to global warming, producing as much as one-tenth of industry-generated greenhouse-gas emissions. Now a new study suggests a way in which those emissions could be reduced by more than half — and the result would be a stronger, more durable material.
The findings come from the most detailed molecular analysis yet of the complex structure of concrete, which is a mixture of sand, gravel, water, and cement. Cement is made by cooking calcium-rich material, usually limestone, with silica-rich material — typically clay — at temperatures of 1,500 degrees Celsius, yielding a hard mass called “clinker.” This is then ground up into a powder. The decarbonation of limestone, and the heating of cement, are responsible for most of the material’s greenhouse-gas output.
The new analysis suggests that reducing the ratio of calcium to silicate would not only cut those emissions, but would actually produce better, stronger concrete. These findings are described in the journal Nature Communications by MIT senior research scientist Roland Pellenq; professors Krystyn Van Vliet, Franz-Josef Ulm, Sidney Yip, and Markus Buehler; and eight co-authors at MIT and at CNRS in Marseille, France.
“Cement is the most-used material on the planet,” Pellenq says, noting that its present usage is estimated to be three times that of steel. “There’s no other solution to sheltering mankind in a durable way — turning liquid into stone in 10 hours, easily, at room temperature. That’s the magic of cement.”
In conventional cements, Pellenq explains, the calcium-to-silica ratio ranges anywhere from about 1.2 to 2.2, with 1.7 accepted as the standard. But the resulting molecular structures have never been compared in detail. Pellenq and his colleagues built a database of all these chemical formulations, finding that the optimum mixture was not the one typically used today, but rather a ratio of about 1.5.
As the ratio varies, he says, the molecular structure of the hardened material progresses from a tightly ordered crystalline structure to a disordered glassy structure. They found the ratio of 1.5 parts calcium for every one part silica to be “a magical ratio,” Pellenq says, because at that point the material can achieve “two times the resistance of normal cement, in mechanical resistance to fracture, with some molecular-scale design.”
The findings, Pellenq adds, were “validated against a large body of experimental data.” Since emissions related to concrete production are estimated to represent 5 to 10 percent of industrial greenhouse-gas emissions, he says, “any reduction in calcium content in the cement mix will have an impact on the CO2.” In fact, he says, the reduction in carbon emissions could be as much as 60 percent.
In addition to the overall improvement in mechanical strength, Pellenq says, because the material would be more glassy and less crystalline, there would be “no residual stresses in the material, so it would be more fracture-resistant.”
The work is the culmination of five years of research by a collaborative team from MIT and CNRS, where Pellenq is research director. The two institutions have a joint laboratory at MIT called the Multi-Scale Materials Science for Energy and Environment, run by Pellenq and Ulm, who is director of MIT’s Concrete Sustainability Hub, and hosted by the MIT Energy Initiative.
Because of its improved resistance to mechanical stress, Pellenq says the revised formulation could be of particular interest to the oil and gas industries, where cement around well casings is crucial to preventing leakage and blowouts. “More resistant cement certainly is something they would consider,” Pellenq says.
So far, the work has remained at the molecular level of analysis, he says. “Next, we have to make sure these nanoscale properties translate to the mesoscale” — that is, to the engineering scale of applications for infrastructure, housing, and other uses.
Zdeněk Bažant, a professor of civil and environmental engineering, mechanical engineering, and materials science and engineering at Northwestern University who was not involved in this research, says, “Roland Pellenq, with his group at MIT, is doing cutting-edge research, clarifying the nanostructure and properties of cement hydrates.”
The Concrete Sustainability Hub is supported by the Portland Cement Association and the Ready Mixed Concrete Research and Education Foundation. | | 1:05p |
Researchers engineer new mouse model to study disease Researchers from the Broad Institute and MIT have created a new mouse model to simplify application of the CRISPR-Cas9 system for genome-editing experiments in living animals.
The researchers successfully used the new “Cas9 mouse” model to edit multiple genes in a variety of cell types, and to model lung adenocarcinoma, one of the most lethal human cancers. The mouse has already been made available to the scientific community and is being used by researchers at more than a dozen institutions.
A paper describing this new model and its initial applications in oncology appears today in the journal Cell.
In recent years, genetic studies have found thousands of links between genes and various diseases. But in order to prove that a specific gene is playing a role in the development of the disease, researchers need a way to perturb it — that is, turn the gene off, turn it on, or otherwise alter it — and study the effects.
A convenient genome-editing system
The CRISPR-Cas9 genome-editing system is one of the most convenient methods available for making these alterations in the genome. While the tool is already being used to test the effects of mutations in vitro — in cultured cell lines, for instance — it is now possible to use this tool to study gene functions using intact biological systems.
The CRISPR-Cas9 system relies on two key features to edit the genome: Cas9, a “cleaving” enzyme capable of cutting DNA; and guide RNA, a sequence that directs Cas9 to the DNA target of interest in the genome. However, the Cas9 enzyme presents some delivery challenges for in vivo applications.
“By equipping the mouse with Cas9, we relieved the burden of delivery. This frees up space for the delivery of additional elements — whether by viruses or nanoparticles — making it possible to simultaneously mutate multiple genes and even make precise changes in DNA sequences,” says Randall Platt, a graduate student at MIT working at the Broad Institute in the lab of Feng Zhang, an assistant professor at the McGovern Institute for Brain Research at MIT. Platt and Sidi Chen, a postdoc at MIT’s Koch Institute for Integrative Cancer Research working in the lab of Institute Professor Phillip Sharp, were co-first authors of the paper.
This ability to perturb multiple genes at the same time may be particularly useful in studying complex diseases, such as cancer, where mutations in more than one gene may drive disease. To demonstrate a potential application for cancer research, the authors used the “Cas9 mouse” to model lung adenocarcinoma. Previously, scientists working with animal models have had to knock out one gene at a time, or cross animal models to produce one with the needed genetic modifications, processes that are challenging and time-consuming.
Empowering researchers
“The ‘Cas9 mouse’ allows researchers to more easily perturb multiple genes in vivo,” says Zhang, who, along with Sharp, served as co-senior author of the Cell paper. “The goal in developing the mouse was to empower researchers so that they can more rapidly screen through the long list of genes that have been implicated in disease and normal biological processes.”
Researchers contributing to the paper also found that cells derived from the “Cas9 mouse” could be extracted for use in lab experiments, and were able to leverage the Cas9-expressing cells to edit immune dendritic cells even after the cells had been removed from the mouse, allowing the researchers to experiment with cells that aren’t easily accessible and often lack the shelf life to conduct such experiments.
“As we demonstrated with immune cells, the mouse allows us to experiment with cells that only remain viable for a few days ex vivo by leveraging the fact that they already express Cas9. Absent the expression of Cas9, we would not have sufficient time for the CRISPR system to work its magic,” says co-author Aviv Regev, who is an associate professor of biology at MIT. Regev’s lab, along with the lab of Broad senior associate member Nir Hacohen (a faculty member at Massachusetts General Hospital and Harvard Medical School), used the mouse to investigate dendritic cells, as reported in the Cell study.
“Genetic manipulation is one of the most critical tools we have for investigating complex circuits, and the ‘Cas9 mouse’ will help us do it more effectively,” Regev says.
The “Cas9 mouse” has been deposited with the Jackson Laboratory, in Bar Harbor, Maine, where it is available to the entire scientific community by request.
This engineered mouse should allow scientists to more easily study the dynamic genetic events that unfold during the progression of cancer and other diseases, says Luciano Marraffini, an assistant professor of bacteriology at Rockefeller University who was not part of the research team.
“This is one step up in the development of new tools based on Cas9 and CRISPR,” he says. “The development of a mouse in which Cas9 can be induced in a very specific way is something that is going to be a great tool.”
The study was supported by the National Science Foundation; the Damon Runyon Cancer Research Institute; the Simons Center for the Social Brain at MIT; the National Human Genome Research Institute; the National Cancer Institute; the National Institute of Mental Health; the Helmsley Charitable Trust; the Klarman Cell Observatory; the Koch Institute for Integrative Cancer Research; the Broad Institute’s Stanley Center for Psychiatric Research; the Howard Hughes Medical Institute; the Marie D. and Pierre Casimir-Lambert Fund; Bob Metcalfe; and the Keck, Searle Scholars, Klingenstein, Vallee, and Merkin foundations. | | 6:03p |
Judi Segall named ombudsperson The Office of the President has appointed Judi Segall, a highly accomplished conflict management specialist, as MIT’s newest ombudsperson. Segall began in this position on Sept. 2.
Segall joins current ombudsperson Toni Robinson in leading the MIT Ombuds Office, which serves the MIT community as an independent, neutral resource on a wide range of policy and conflict-resolution matters. Segall replaces longtime MIT ombudsperson Mary Rowe, who retired on Sept. 14 after 41 years of service to the Institute.
In her new role, Segall will informally, impartially, and confidentially help MIT community members resolve disputes, convey concerns, and express their points of view. She will also work with her fellow ombuds — including representatives at MIT Lincoln Laboratory — to help identify problems, promote ethical conduct, and facilitate positive growth within the Institute.
Segall joins MIT from Stony Brook University, where she served for the past 17 years as university ombudsman and director of the Stony Brook Ombuds Office. Her responsibilities there included directing management and oversight of all Ombuds Office operations; conducting informal consultations with administrators and managers to raise awareness of systemic problems; and leading conflict management training courses and outreach programs for faculty, students, and staff.
Since 1997, Segall had also been also a clinical lecturer in the Stony Brook School of Social Welfare. There, she developed curriculum for the social work master’s program and taught advanced graduate student seminars on leadership development, organizational change, and conflict management.
Prior to her directorship of the Stony Brook Ombuds Office, Segall served from 1989 to 1997 as the executive assistant to Stony Brook’s vice president for student affairs.
Throughout her career, Segall has held various local, national, and international conflict-resolution leadership positions. Most recently, these have included service as president of the International Ombudsman Association; president of the Ombudsman Association; and president of the University and College Ombuds Association.
Segall holds a BA in history from the State University of New York at Oswego and a master’s in social work from Stony Brook University. She was awarded certification from the Center for Mediation in Law in 2005, and in 2011 was certified as an organizational ombudsman practitioner.
The MIT Ombuds Office was established in 1980 by former MIT President Paul Gray to serve as a voice for the students, faculty, and staff of MIT. Currently there are more than 500 academic, corporate, and government ombuds programs across the country, charged with advancing constructive conflict management and supporting positive systems change. Ombudspeople within these programs may also act as consultants and mediators in internal disputes. |
|