“Little Buddies,” Big Goals: An Evaluation of a Youth Mentoring Program

Hi Tribe! My name is Phoebe Flint and I’m so thrilled to be able to conduct research over the summer with the support of the Charles Center and my advisor, Dr. Elizabeth Raposa. I’m currently studying in Scotland, but I’m looking forward to coming back home to Williamsburg to get started on my project!

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Abstract: How the Latitude of a Lake Affects Lead Concentrations in Sediment Cores

Lead is a toxin that is known to affect many major organs in the human body if ingested. This summer and into the fall I will be conducting research comparing total lead concentrations in various lake sediment cores. The lead composition in the stratigraphy of the cores can reflect different anthropogenic lead sources such as coal combustion, ore smelting, and combustion of gasoline containing lead. In the 1970’s the United States’ Congress passed legislation banning the sale of the gasoline containing lead. This resulted in lower rates of atmospheric lead deposition. However, once lead goes into the atmosphere it can travel thousands of miles before being removed and deposited on the Earth’s surface, which is one reason it can be observed in lake cores across the globe. The actual extent that the lead from these sources traveled is unknown. Therefore; first, I want to see if lead can be found in lake sediment cores located at high latitudes, and second, assuming lead will be found, see if the concentrations seem to match up proportionally to those of cores at lower latitudes. The first core I will be looking at will be taken from a lake on Vestvagoy Island, which is one of the Lofoten Islands located in northern Norway at about 68 degrees north latitude. The second core will be taken from Lake Matoaka on William and Mary’s campus located at 37 degrees north latitude. For each core I’m going to take samples down the core and let them dry out in an oven, so I can grind them into a fine powder. Then I will ash them at 475 degrees Celsius for 6 hours. The ash residue will be digested in 10 ml of a 1:1 by volume solution of nitric acid, and then be filtered and diluted to 60ml with deionized water. Next I will use a plasma emission spectroscopy to analyze the diluted digestion for lead content. The recovery of lead should be greater than 90 percent, which is the high purity standard. I expect the plotted stratigraphy from the Norway core to resemble that of the Matoaka core, but for there to be a lower lead concentration observed overall. This would lead to the conclusion that lead concentration decreases with increased latitude.

Abstract: Understanding Dye-Sensitized Solar Cells

My name is Simran Rohatgi and I am a senior in Dr. Kristin Wustholz’s Physical Chemistry lab. My project deals with understanding how dye-sensitized solar cells (DSSCs) work on the molecular level to harness solar energy and convert it to electricity. Relative to traditional silicon-based solar cells, DSSCs inexpensive and versatile, but they are not as efficient as silicon-based cells and therefore are not widely used. A molecular-level understanding of the electron transfer (ET) processes that take place inside the DSSC may help us understand why they are not as efficient as expected. Once we gain this understanding, scientists may be able to improve the efficiency of DSSCs so that they can begin to play a role in solving the energy crisis facing our planet. This summer, I hope to study DSSC systems using a combination of single molecule (SM) and fluorescence lifetime spectroscopies. SM studies allow us to observe ET processes of individual dye molecules, instead of obtaining averaged data, which would be less valuable due to the heterogeneous nature of the environment inside DSSCs. Additionally, fluorescence lifetime measurements will allow the observation of ET processes down to the picosecond timescale. The molecular-level understanding provided by these combined techniques may help us to explain the plateau in dye-sensitized solar cell (DSSC) efficiency that has been observed in the past decade.

Abstract: Queering the Voices of the Past

Hello! My name is Sarah Rodriguez, and I am a rising senior at William & Mary majoring in History and minoring in Economics. As reflected in many of my course choices over the years, I am primarily interested in taking a gendered analysis of history across all times and places and especially studying the history of women and LGBTIQ individuals of different racial, ethnic, and class backgrounds.

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Abstract: The Role of Sexual Adhesins in Yeast Speciation

Hello, my name is Rachel and I’m a junior at the College. This summer, I will work in the Murphy lab to investigate speciation in populations of the yeast Saccharomyces paradoxus. Speciation is the evolutionary process by which new and distinct species arise from a single species. Usually, one population splits into two, and the populations diverge from one another until they can no longer reproduce successfully if they come back into contact. In my project, I will investigate the mechanisms and genetic basis of speciation in eukaryotic microbes. Specifically, I am interested in determining if genes required for sexual reproduction are undergoing selection and preventing diverging populations from mating with one another, completing speciation.

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