Proteins perform a vast array of functions within all living organisms. These functions are heavily dependent on the protein’s 3-D structure. Cellular stress can result in the loss of protein structure and can lead to a wide variety of problems, one being the formation of insoluble protein aggregates. Aggregates can inhibit proper protein function, disrupt cellular homeostasis, and are implicated in many diseases. There exists a family of proteins, known as the Small Heat Shock Proteins (sHSPs), which are thought to combat aggregate formation. They interact with misfolded and aggregate-prone proteins (clients) to delay the formation of insoluble aggregates. How sHSPs delay aggregation is not well understood. I seek to characterize interactions between sHSPs and their clients. A binding interaction between the sHSP αB crystallin and the model client Δ131Δ (a mutant of staphylococcal nuclease) has previously been characterized by NMR. My goal is to confirm this interaction and look for additional interactions between these two proteins through chemical cross-linking. Chemical cross-linking is a process that links two proteins that interact. One can use this method to detect which surfaces of proteins are involved in a protein-protein interaction. The chemical cross-linker I am using is incorporated as an unnatural amino acid (p-benzoyl-L-phenylalanine, or BpA) into the sHSP αB crystallin. Upon exposure to UV light, BpA can covalently cross-link to another protein if it comes into close contact with it. This approach can allow us to explore how sHSPs interact with the client Δ131Δ. By gaining an understanding of this specific sHSP-client interaction, I hope to provide insight into general mechanisms of how sHSPs interact with clients, a process that plays a critical role in cellular health.

My experience on a short term medical mission trip to Guatemala in 2010 left me with an uneasiness. In the face of the experience itself, much post-trip discourse has been centered largely on its value as social capital. The goal of my research is to begin to unravel the complex emotions that take place both at the site of contact in the third-world host country and after returning home. In the face of the ubiquity of short term mission trips, their increasing necessity for professional and educational development, and the vast amount of development literature, this emotional ambiguity is left out. I plan to unpack and illuminate this internal conflict as a way to understand the dual nature of its effects. As an overall objective, I hope that this project invites further discussion about short term volunteer programs and their complexities. Additionally, my research questions ask what evidence of this duality in their own experiences there might be in personal accounts of returnees. Additionally, I plan to address the source, context, and representation of this ambiguity, if it does in fact exist for others, as well. My methods consist of revisiting my experience through an autoethnography and collecting data from the trip. I also include personal narratives from several returned volunteers willing to share their experiences, as well as reviewing much of the academic literature about short term trips. I plan to present emergent broad themes and possible significance for others preparing to go on a short term volunteer trip. These themes include mixed feelings about the trip in the form of a duality, the manner in which relationships formed in the contact zone might affect personal beliefs about the work being done on the trip, and the ambiguity of short term mission trips in terms of their helpfulness or harm.

This paper exanimates how the contribution of education to individual’s earning changes under economic recession. Previous economists have established the Employer Learning Model, which demonstrates that the relation between education and earning is strong at the start of one’s career but weakened through time. This paper compares this relation between education and earning during recession and non-recession periods. The study is based on the cross-sectional data from National Longitudinal Surveys that include comprehensive information about individuals’ working and educational experience. The study applies a difference in means test that builds upon a regression of individual’s education, ability (estimated by AFQT score) and years of working experience on earning. By comparing the difference in causal effects between recession and non-recession periods, this paper shows that under recession the impact of education on earning is weaker at the beginning of one’s career and diminishes faster through time. The result suggests that in economic downturn, the signal factors such as years of schooling, race and gender have less impact on individuals’ earnings. Individual’s true ability is revealed faster too. One of explanations of this result that the paper discussed is that under recession, firms have more incentives to observe employee’s productivity actively and efficiently both before and after hiring. Other inferences of the result are also included in the paper.

Diatoms are an important taxon of phytoplankton that contribute to both freshwater and marine ecosystem function. For example, marine diatoms are responsible for about 14% of global primary production. My research is focused on determining the ability of these algae to regulate the production of chlorophyll a- the core pigment component of photosynthetic complexes. The enzyme light-dependent NADPH protochlorophyllide oxidoreductase (POR) is a key regulator of chlorophyll synthesis. Whereas most organisms have just one POR enzyme, diatoms have two (POR1 and POR2). The goals of this project are to understand how these enzymes are metabolically different from one another in: (a.) their enzymology and (b.) their regulation at the transcriptional and posttranslational levels. To this end, plasmids were constructed encoding the cDNAs of the por genes, adding N-terminal histidine tags to assist in affinity purification. E. coli, transformed with these plasmids, was induced to express the proteins; harvested, and lysed. Recovered POR1 and POR2 proteins were purified from the lysate by affinity chromatography. Antibodies raised against these proteins were used in Western blot protein identification and quantitation of the targeted proteins. Preliminary experiments demonstrate good affinity of generated antibodies for POR proteins, and indicate that POR 2 may be post-transcriptionally truncated. Developing an understanding of chlorophyll metabolism in diatoms has not only ecological implication, but also could prove important in commercial aspects of biofuel development- increasingly important issues driven by changing ocean conditions and the critical need for generating alternative fuel sources. Determining the properties of these enzymes and their regulation is just one step towards understanding the successful productivity of diatoms. Further studies may be required to determine if there are additional regulatory pathways and enzymes that are critical in photosynthetic production.

Childhood epileptic encephalopathies (CEE) are a subset of rare epilepsies, largely characterized by seizures and mental disabilities. Recent studies, including those by the Mefford lab, have shown that about 30% of CEE is caused by mutations in specific genes.These mutations are ‘de novo’ – they arise during fertilization or the development of the embryo. While many types of epilepsy have a hereditary basis, de novo mutations are increasingly recognized as significant risk factors in some epilepsies. The mutations also change the amino acids that make up proteins and are mostly in exons – parts of the DNA that code for protein. Few studies focus on synonymous mutations that do not change the amino acids of a protein or mutations in introns –pieces of DNA that have regulatory function but do not code for protein. We have previously sequenced 29 known epilepsy genes in a cohort of 800 CEE patients, but focused primarily on exonic mutations that change the protein sequence. My goal is to understand whether intronic or synonymous mutations that we have already found in these patients are inherited or de novo. We hypothesize that these classes of de novo mutations disrupt the typical formation of RNA transcripts, which in turn results in an absent or mutant protein. I will use molecular inversion probe (MIP) capture to determine the inheritance of intronic variants in patients with CEE. A MIP is a piece of DNA that is designed to target specific regions of DNA which are then amplified and analyzed; the technique enables us to capture a large number of variants at once. Discovering de novo variants in intronic regions of genes will deepen our understanding of the cause of CEE. These variants will inform us of affected biological pathways and contribute information for future CEE treatments.