Science & Technology

Studies by Varekamp, Thomas Published in Paleoceanography

varekamp

Joop Varekamp

Ellen Thomas

Ellen Thomas

Wesleyan faculty Joop Varekamp and Ellen Thomas are among the authors of a paper on rates of sea-level rise along the eastern U.S. seaboard titled “Late Holocene sea level variability and Atlantic Meridional Overturning Circulation,” published in the journal Paleoceanography, Volume 29, Issue 8, pages 765–777 in August 2014. Varekamp is the Harold T. Stearns Professor of Earth Science, professor of earth and environmental sciences and professor of environmental studies. Thomas is research professor of earth and environmental sciences at Wesleyan, and also a senior research scientist in geology and geophysics at Yale University.

Ellen Thomas discovered that microfossils, such as this  foraminifera fossil, reveal that warm oceans had less oxygen.

Ellen Thomas discovered that microfossils, such as this foraminifera fossil, reveal that warm oceans had less oxygen.

Pre-20th century sea level variability remains poorly understood due to limits of tide gauge records, low temporal resolution of tidal marsh records, and regional anomalies caused by dynamic ocean processes, notably multidecadal changes in Atlantic Meridional Overturning Circulation (AMOC). In the study, Varekamp and Thomas examined sea level and circulation variability along the eastern United States over the last 2,000 years, using a sea level curve constructed from proxy sea surface temperature records from Chesapeake Bay, and 20th century sea level-sea surface temperature relations derived from tide gauges and instrumental sea surface temperatures.

Thomas also is a co-author of a paper titled ‘I/Ca evidence for upper ocean deoxygenation during the PETM‘ published in the Paleoceanography, October 2014.

In this paper, Thomas suggests that the Paleocene-Eocene Thermal Maximum (PETM), a potential analog for present and future global warming, may help in such forecasting future deoxygenation and its effects on oceanic biota. Forecasting the geographical and bathymetric extent,

Makri’s Power Limiter Research Noted in Scientific Reports Article

Makri used a power limiter consisting of a nonlinear lossy layer embedded in two mirror layers. This setup provides a resonant transmission of a low intensity light and nearly total reflectivity of a high-intensity light.

Makri used a power limiter consisting of a nonlinear lossy layer embedded in two mirror layers. This setup provides a resonant transmission of a low intensity light and nearly total reflectivity of a high-intensity light.

A study co-authored by Graduate Research Assistant Eleana Makri and two other Wesleyan researchers is a topic of a Oct. 20 article published in Scientific Reports.

Due to the ultrahigh-speed and ultrawide-band brought by adopting photons as information carriers, photonic integration has been a long-term pursuit for researchers, which can break the performance bottleneck incurred in modern semiconductor-based electronic integrated circuits. The article states that “recently, Makri theoretically proposed the concept of reflective power limiter based on nonlinear localized modes, where a nonlinear layer was sandwiched by two reflective mirrors, thus increased the device complexity.”

The report is based on Makri’s study, titled “Non-Linear Localized Modes Give Rise to a Reflective Optical Limiter” published in March 2014. The paper is co-authored by Tsampikos Kottos, the Douglas J. and Midge Bowen Bennet Associate Professor of Physics; Hamidreza Ramezani Ph.D. ’13 (now a postdoc at U.C. Berkeley) and Ilya Vitebskiy (Sensors Directorate at the Air Force Research Laboratory, Ohio).

The same study was also highlighted in Washington, D.C. at the spring review meeting of the Air Force Office of Scientific Research (AFOSR) as one of the main research achievements in electromagnetics of 2014 that can potentially benefit the U.S. Air Force. Read more about this study in this past News @ Wesleyan article.

Read the full Scientific Report article, titled “Chip-integrated optical power limiter based on an all-passive micro-ring resonator,” online here.

Kottos, Basiri Author Paper Published in Physical Review

Data by Tsampikos Kottos and Ali Basiri.

Tsampikos Kottos and Ali Basiri, a Ph.D. student in physics, are co-authors of a paper titled “Light localization induced by a random imaginary refractive index,” published in Physical Review A 90, on Oct. 13, 2014. Kottos is the Douglas J. and Midge Bowen Bennet Associate Professor of Physics.

In the paper, the authors show the emergence of light localization in arrays of coupled optical waveguides with randomness.

 

 

 

Hughes Finds Magnetic Fields in Stardust; Study Published in Nature

Assistant professor of Astronomy Meredith Hughes and eight colleagues have found evidence of magnetic fields in stardust – an indication that magnetic fields are important in the process of planetary system formation, according to a new paper in the journal Nature.

The discovery is another step in work by Hughes and other astronomers to understand how celestial bodies are formed. It is known that magnetic fields in the “accretion disks” of stars play a dominant role in the star formation process.

Meredith Hughes

Meredith Hughes

Using data from an observatory near Bishop, Calf., Hughes and her colleagues were able to spot signs of magnetic fields in the dust of the disk of a star about 300 light years away. While magnetic fields have been detected in regions that represent the very earliest stages of star formation (the so-called Class 0 and Class I stages), this is the first time they have been seen around a star with an older age closer to when we believe planetary systems form.

“This is an important result,” Hughes said. “It’s the first time that we’ve seen magnetic fields this late in the process of star and planet formation. And like any good scientific result, when you find something new it opens up whole new sets of questions we can ask.”

In fact, Hughes said the astronomers did not expect the results they got. “I honestly didn’t think it was going to work – we had been trying so long with Class II sources and hadn’t found anything,” she said. “But I thought, we might as well try this last source that is just a little younger than most Class II sources. You want to try everything you can – but it was really a surprise when it worked.”

The paper, “Spatially resolved magnetic field structure in the disk of a T Tauri star,” was published Oct. 22. Nature is the world’s most highly-cited interdisciplinary science publication. The 145-year-old journal is published weekly.

Math Ph.D. Candidate Smith Delivers First Graduate Speaker Series Talk

Brett Smith, a Ph.D. candidate in mathematics, spoke during the first Graduate Speaker Series event Oct. 7 in Exley Science Center. Smith's talk, titled "Mine, Yours and the Truth," focused on American mobster Joe Massino, boss of the Bonanno crime family in New York from 1991 until 2004. "Big Joey" famously said, “there are three sides to every story — mine, yours and the truth.”

Brett Smith, a Ph.D. candidate in mathematics, spoke during the first Graduate Speaker Series event Oct. 7 in Exley Science Center. More than 50 students, faculty and staff attended the event. Smith’s talk, titled “Mine, Yours and the Truth,” focused on American mobster Joe Massino, boss of the Bonanno crime family in New York from 1991 until 2004. “Big Joey” famously said, “there are three sides to every story — mine, yours and the truth.”

By using a graph theory called the Robertson–Seymour theorem, Smith explored the competing questions, "What is the best way to organize a mafia so that you won't be caught?" and "What is the best way to patrol a city to disrupt organized crime?" Smith explained how these questions are one and the same.

By using a graph theory called the Robertson–Seymour theorem, Smith explored the competing questions, “What is the best way to organize a mafia so that you won’t be caught?” and “What is the best way to patrol a city to disrupt organized crime?”
Smith explained how these questions are one and the same.

Three more graduate students will tentatively speak as part of the series this fall and next spring including Duminda Ranasinghe, a chemistry Ph.D. candidate; Katie Kaus, a molecular biology and biochemistry Ph.D. candidate and Peter Blasser, a graduate student in music. For more information, visit the Graduate Studies website.

Grad Student Herman, Sultan Published in Evolution, Faculty 1000

Jacob Herman

Jacob Herman

Biology Ph.D. candidate Jacob Herman and Sonia Sultan, chair and professor of biology, professor of environmental studies, are the co-authors of an article titled “How stable ‘should’ epigenetic modifications be? Insights from adaptive plasticity and bet hedging,” published in Evolution, Issue 68(3), pages 632-43. Herman was the Private Investigator on the paper.

The article also was selected by Faculty 1000, a platform for life scientists that helps scientists to discover, discuss and publish research.

Sonia Sultan

Sonia Sultan

Epigenetics is the study of ways chemical reactions change the way an organism grows and develops, and the factors that influence them. Epigenetic modifications can be stable across the individual’s lifespan and in some species even persist across generations, or they can be reversible, but it is currently unclear how the persistence of epigenetic modifications may evolve. In this paper, Herman and Sultan provide insights from the theoretical advances in adaptive phenotypic plasticity to predict the conditions that would favor the evolution of stable versus reversible epigenetic modification as an adaptive environmental response both within and across generations.

At Wesleyan, Herman is interested in the evolutionary implications of developmental plasticity. In particular, he has been studying transgenerational plasticity, a phenomenon that occurs when environments experienced by parents (or even more remote generations) influence the phenotypes of offspring, without changing the DNA sequence.

“There is a growing body of research in both plants and animals that suggests that transgenerational plasticity can have important ecological and evolutionary impacts, including influences on response to selection and population persistence in stressful environments,” he said.

Polygonum persicaria

Polygonum persicaria

Herman’s doctoral research focused on adaptive seedling responses to grandparental and parental drought stress in the widespread, introduced plant Polygonum persicaria.

“We found that functionally appropriate responses to drought stress persist across at least two generations in this species. These adaptive effects enhanced the growth and survival of ‘grandchild’ seedling offspring grown in drought conditions,” he said.

Herman’s research is one part of the larger effort in the Sultan lab to understand how individual plants respond to key environmental stresses, such as drought, and how those responses influence species’ ecology and evolution.

Learn more about ongoing research in the Sultan Lab here.

Wesleyan to Host Archaeology Fair, Oct. 18

The Connecticut State Archaeology Fair, hosted at Wesleyan, will give the public a close-up look at projects happening across the state. The theme is "Creating Community."

The Connecticut State Archaeology Fair, hosted at Wesleyan, will give the public a close-up look at projects happening across the state. The theme is “Creating Community.”

Many people think of archaeology as taking place in exotic locations overseas, not in their own backyard. Yet archaeology projects are continuously being carried out all over the state of Connecticut.

On Oct. 18, Wesleyan’s Archaeology Program and Office of Community Partnerships will present the Connecticut State Archaeology Fair to give the public a close-up look at some of these projects. Part of Archaeology Awareness Month in October, the fair will feature many hands-on exhibits and activities for adults and kids. Presenters will represent a full spectrum of archaeology in the state, ranging from local tribes and community groups to educational institutions and commercial businesses.

Beman Triangle dig

Wesleyan students dig for artifacts at the “Beman Triangle” near campus.

The fair will take place from 10 a.m. to 4 p.m. in Exley Science Center. While it has been held elsewhere in the state in the past, this is Wesleyan’s first year hosting it. This year’s theme is “Creating Community.”

According to Sarah Croucher, assistant professor of anthropology, assistant professor of archaeology, assistant professor of feminist, gender and sexuality studies, “Connecticut has amazing archaeological resources, and many projects being done all around the state, but a lot of it goes under the public radar. This is a great opportunity for members of the public to learn about archaeology, and see first-hand some of the cool work going on right here in Connecticut.”

Royer’s Study Suggests that the Meteorite That Wiped Out Dinosaurs Changed Forests

Dana Royer, associate professor of earth and environmental sciences.

Dana Royer, associate professor of earth and environmental sciences, is the co-author of a study that suggests fast-growing deciduous plants replaced slower-growing evergreen plants after an impact of a meteorite 60 million years ago. (Photo by Olivia Drake)

Sixty-six million years ago, a meteorite struck the Earth with enough force that the ensuing environmental changes, including floods, earthquakes, variable temperatures and light-obscuring dust clouds, possibly wiped out dinosaurs and other pre-historic life. Scientists believe this opened a path for mammals, and ultimately humans, to evolve.

A new study by Dana Royer, associate professor of earth and environmental sciences, and colleagues from the University of Arizona and the Denver Museum of Nature and Science suggests that the chaos in the wake of the space rock’s impact changed the Earth’s plant life as well. Deciduous plants survived and flourished to a much greater extent than flowering evergreens, the scientists believe, probably because their properties made them much better able to respond to climate conditions post-impact. The deciduous plants, not needing to maintain their leaves year round, essentially needed less energy for survival.

Mukerji Represents Wesleyan at National STEM Meeting

Ishita Mukerji

Ishita Mukerji

Ishita Mukerji, dean of natural sciences and mathematics and director of technology initiatives, represented Wesleyan at a White House-sponsored conference of STEM educators Sept. 16.

Mukerji said she was intrigued by other universities’ approaches to increase access to science, technology, engineering and math – and happy to share Wesleyan’s STEM initiatives with her counterparts.

“It was a great opportunity to learn about what works and compare with what we are doing,” said Mukerji, who also is professor of molecular biology and biochemistry.”I was happy to see that in many instances, we were on the right track and have some of the key elements in place.”

The conference was a followup to a January meeting at the White House, attended by President Michael Roth and about 100 other leaders in higher education. That gathering, part of the White House College Opportunity initiative, asked the leaders how their institutions were increasing access. Wesleyan’s commitment to opening access in STEM fields

Royer’s Study Published in PLOS Biology

Dana Royer

Dana Royer

Dana Royer, associate professor of earth and environmental sciences, is the co-author of “Plant Ecological Strategies Shift Across the Cretaceous-Paleogene Boundary,” published in PLOS Biology on Sept. 15.

The study reveals that a meteorite that hit Earth 60 million years ago – and may have led to the mass extinction of the world’s dinosaur population – also led to a shift in the landscape of plants, particularly deciduous plants.

Royer and his colleagues showed how they applied bio-mechanical formulas to fossilized leaves of flowering plants dating from the last 1.4 million years of the Cretaceous period and the first 800,000 of the Paleogene. Read more about Royer’s study in this News @ Wesleyan article.

Burge Specializes in Software Engineering, Design Rationale

anet Burge, associate professor of computer science, is teaching a service learning course, COMP 342 Software Engineering, this fall. The course includes a survey of current programming languages, advanced topics in a specific language, design patterns, code reorganization techniques, specification languages, verification and tools for managing multiple-programmer software projects. Burge joined the Wesleyan faculty this semester. (Photo by Olivia Drake)

Janet Burge, associate professor of computer science, is teaching a service learning course, COMP 342 Software Engineering, this fall. The course includes a survey of current programming languages, advanced topics in a specific language, design patterns, code reorganization techniques, specification languages, verification and tools for managing multiple-programmer software projects. Burge joined the Wesleyan faculty this semester. (Photo by Olivia Drake)

Q: Welcome to Wesleyan, Professor Burge! Please fill us in on your life up to now.

A: I’m originally from Michigan, and attended undergrad at Michigan Tech. I moved out to Massachusetts and worked on radar systems for quite a few years. I did a lot of off-site work traveling all around the country; it’s exciting to see the products you build in action. I always planned to go back to graduate school, and I decided to pursue a master’s in computer science at Worcester Polytechnic Institute. I started out there part time, but then an opportunity arose and I made a quick decision to go full time to earn a Ph.D. I then taught for nine years at Miami University in Ohio before coming to Wesleyan. I’m very excited to be here.

Q: How did you wind up at Wesleyan, and what is your impression of the school so far?

A: From the time I was a high school student, I wanted to be at a small liberal arts college, but it never quite worked out before now. I also knew a few former and current faculty members at Wesleyan, and they raved about the students here. If anything, the students are even more awesome than they had told me.

Grant Supports Partnership between Cognitive Development Lab, CT Science Center

Cognitive Development Lab students Ziyue Li '16 and Portia Lundie '14 spoke with children and parents at the Connecticut Science Center last spring.

Cognitive Development Lab students Ziyue Li ’16 and Portia Lundie ’14 spoke with children and parents at the Connecticut Science Center last spring.

Faculty and student researchers from Wesleyan’s Cognitive Development Lab recently received a $3,000 stipend from the National Living Laboratory® Initiative, which receives support from the National Science Foundation. The award will support an ongoing collaboration between Wesleyan and the the Connecticut Science Center.

Hilary Barth, associate professor of psychology, associate professor of neuroscience and behavior, oversees a Living Laboratory® site at the science center’s museum. For the past year and a half, Wesleyan researchers have visited the museum on Saturdays to collect data for current studies, talk with children and their families about child developmental research, and guide visitors in hands-on activities that demonstrate important findings in developmental psychology.

The stipend will support staff at the museum, student coordination and museum visit time for the students, travel costs, signage and materials for the lab’s child development demonstrations. In 2013, the Living Laboratory Initiative awarded Wesleyan with a $300 grant for signage.

According to its website, The Living Laboratory® initiative aims to educate the public about child development by immersing museum visitors in the process of scientific discovery. In the Living Laboratory®’s educational model, scientists (in disciplines including developmental psychology, cognitive science, educational psychology, cognitive neuroscience, social psychology and related fields) recruit participants and conduct their studies within dynamic exhibits at a local museum. Families visiting the museum are invited to participate in on-going research projects and to engage in one-on-one conversations with the scientists.

Read past articles about the Cognitive Development Lab here.