In July of 2016, I was a part of the exploration seminar: ‘Global Health Promotion: Health Services Delivery in Resource-poor Settings’ led by Professor Mabel Ezeonwu, where students spent two weeks in Guatemala. While conducting research in six rural villages in Guatemala, my team, Briana Hermes, MyKa’La Alexander and I asked the question “what are the gender roles for women, especially within a healthcare setting?” We worked from feminist theory which argues that gender is a social construction where gender norms are created, performed, and normalized. As researchers, we conducted participant observation through observing the patients receiving health assessments through the clinics we set up. Our participation included delivering basic health care provisions as well as hygiene and dental education. As we worked alongside and within the communities, we observed women’s and men’s roles in an attempt to further understand the daily expectations and responsibilities of women in the villages. We also conducted research, looking for trends and patterns in women’s expected roles while in a health care setting. Here, we found women to be timid while explaining symptoms in addition to refusing some medical services. Through our research, we conclude that Guatemalan women in these six communities are still limited by “traditional” gender expectations. This includes being caretaker of the children, cooking and cleaning which position women’s roles and social status as subordinate to men. Our research raises awareness of gender inequities that are in cultures all around the world, necessary to create a more conscious and positive change in our own society.

Organisms face a range of stressors over the course of their lifespans. As with most traits, we see significant variation in response to stress even between individuals within species. In our attempt to explain differences in stress responses between individuals, the Promislow lab studied the metabolome, the total profile of all small molecules in an organism, and found variation in stress response is correlated with variation in contents of the metabolome. Indeed, in a study of peroxide resistance in the fruit fly, Drosophila melanogaster, we found resistant flies tended to have increased galactose levels, compared to sensitive flies. This observation led to the novel hypothesis that flies fed supplemental galactose will have increased peroxide resistance compared to control flies. For this experiment, we chose flies among the most sensitive and resistant lines examined previously because the most sensitive flies, with low galactose levels, may show increased effects of supplemental galactose on lifespan. In this experiment, flies feed on food with varied galactose concentrations, including a negative control without galactose. We then place the flies into media with peroxide or water, the control. We record the number of flies that die in each condition multiple times a day, and the death rate provides a quantitative measure of peroxide resistance. By comparing the death rate of flies within a line kept in varying concentrations of galactose exposure, we can test the effect of galactose on resistance. If our hypothesis is correct, the flies receiving supplemental galactose should die at a slower rate than those without additional galactose. However, it is possible flies receiving supplemental galactose will die at faster rates, suggesting galactose makes flies more sensitive. Determining whether galactose makes flies more resistant or sensitive to peroxide may prove to be important in counteracting effects of oxidative stress in other organisms.

Oxidative stress arises from an imbalance between reactive oxygen species and an organism’s ability to avoid or repair the damage caused by these reactive molecules. The fruit fly, Drosophila melanogaster, demonstrates varying degrees of resistance to oxidative stress. To understand the genetic basis of this variation, our lab analyzed a collection of inbred, fully sequenced Drosophila lines, the Drosophila Genetic Reference Panel (DGRP), and tested the associations between resistance and each of more than two million single-nucleotide polymorphism (SNP) markers throughout the genome. We found a particular SNP at the second chromosome located within the gene u-shaped (ush), had the strongest statistical relationship with oxidaive stress resistance. We then hypothesized that this gene contributes to the degree of resistance in the flies. For my research, I am evaluating this hypothesis by comparing the peroxide resistance of two sets of genotypes to confirm if the SNP at 2L:531863 bp contributes to the trait. For this comparison, I used two groups of lines, one with the ‘resistant’ and the other with the ‘sensitive’ version of the SNP, and distributed mated females from each line into vials with or without peroxide added into the food. I counted the number of dead flies at regular intervals and used these data to calculate the mean lifespan for each line, where lifespan is a measure of peroxide resistance. If both groups show similar lifespans, it suggests that this particular SNP does not affect peroxide resistance and I may test other SNPs at nearby loci with a similar procedure. However, if the two groups show significant differences in resistance, this result would support the connection between the SNP and peroxide resistance. I would then go on to manipulate the expression of ush using RNA interference to test whether changing mRNA levels impacts peroxide resistance.

Development of antibody-based diagnostics, biomolecular sensors, and biomaterial with reactive surface requires the ability to control the adsorption of bioactive protein at a surface. All medical devices exposed in an in vivo biological environment are immediately coated with a layer of adsorbed protein that plays an important role in the body’s behaviors towards the devices and the effectiveness of the devices themselves. In this study, we use a multi-technique approach to characterize the effect of protein G B1 (6 kDa) orientation on multi-layer antibody binding. By conjugating a cysteine group at different positions along the protein’s surface, we can immobilize five variants of the protein (V21C, D35C, E42C, T11C, and WT) onto maleimide and bare gold surfaces. We have confirmed through X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry experiments that the proteins adsorb onto these surfaces. In addition, we introduced primary IgG and secondary F(ab’)2 antibodies to investigate if the protein’s orientation will affect the binding of the antibodies. The adsorbed mass are measured using quartz crystal microbalance with dissipation monitoring. We have demonstrated that the cysteine mutants orient better on maleimide surfaces and encourage more IgG binding. We will also study the effect of temperature on adsorption mass and extend the experiments to amine and carboxyl functionalized surfaces. Fully developed techniques to accurately characterize the orientation and quantify the amount of protein and secondary adsorption will significantly contribute to understanding the interactions of biomaterials with the biological environment.

Although questionnaires are helpful for identifying employee retention targets in research contexts, such surveys do not benefit employers in small, real-world organizations due to the inevitability of gathering biased data (e.g., due to social desirability or lack of anonymity). The purpose of the current study was to test a tool employers could use to more accurately identify turnover risk and targets for individualized retention strategies. This tool focuses on employee engagement, which research has shown to be related to employee turnover (i.e. high engagement is related to lower employee turnover intentions). This tool enabled us to determine employee level of engagement and predict employee group identification (i.e. long-term retention vs turnover). We hypothesized that higher levels of engagement will predict employee long-term group identity, whereas, low levels of engagement will predict turnover group identity. We conducted a qualitative study using a between-subjects design to compare semistructured phone interviews with 25 community mental health clinicians (13 long-term, 12 turnover), in which we asked clinicians what “ideal changes” they would like to implement in their agency. Using the Q12 Engagement Measurement Model, derived from Maslow’s Hierarchy of Needs, we determined clinician engagement levels, which we then used to predict their group identification. We predict our analyses will reveal that clinicians who suggest more personal-level changes are more likely to be in the turnover group, while clinicians who suggest more altruistic-level changes are more likely to be in the long-term retention group. The literature indicates that employees with higher engagement levels are less likely to turnover; therefore, if we achieve our predicted results, future implications of this study could be that employers could use this tool in their annual review process to more accurately assess employee turnover risk and improve employee retention strategies.

Understanding the role of fluids in active fault zones and the coevolving relationship between fault activity and fluid movements is significant in tectonics research. Calcite (calcium carbonate) veins are a record of past fluids in previously fractured rocks, giving insight into the past environments and conditions for faulting. Studying the characteristics of faulting in the past is key to understanding faulting in the present. I studied carbonate fluid precipitates in carbonate fault rocks from three major fault zones located in the Apennine fold and thrust belt of Italy to better understand this complex coexistence. The faults in this area are active and produce earthquakes. By taking thin sections of rocks from specific domains within the fault zone and using a petrographic microscope, I identified different phases of calcite relating to different stages of fault deformation. Carbon and oxygen isotopes from the CaCO₃ act as tracers for fluid source and evolution. After I identified the characteristics of the minerals that make up the fluid precipitates, I analyzed the minerals for relative abundances of C¹³ and O¹⁸, to better characterize the source of the fluids. These measurements have already been made on rocks from the same area, so I aimed to reproduce the isotopic tracers previously found. This research and characterization of the specific faults and fluids is key in preparing for future clumped isotope measurements.This further work will involve the measurement of relative abundances of a specific isotopologue of CO₂ in our samples with clumped O¹⁸ and C¹³. Temperature and clumping of these isotopes is directly related by the laws of thermodynamics and thus allow us further insight into the origin of fluid originated carbonate veins.

Joubert syndrome (JS) is a genetic neurodevelopmental disorder with medical features including a distinctive hindbrain malformation and developmental delay. All 35 JS-associated genes to date encode gene products localizing to the primary cilium but the mechanism behind JS is still unknown. The primary cilium serves as a cellular antenna for signaling, and when dysfunctional, can lead to the above features and more. One JS-associated gene, INPP5E, is an enzyme that controls phosphatidylinositol (PI) subtype distribution in the ciliary membrane. We hypothesize that abnormal distribution of PI subtypes PI(4,5)P₂ and PI(4)P in primary cilia is central to the JS mechanism, and therefore should be present across genetic causes. To test this hypothesis, I used fluorescently-tagged PI biosensors, domains from naturally occurring proteins that bind to different PI subtypes, and a domain from serotonin receptor (5-HT₆) that marks cilia. The PI biosensors were already tagged with GFP (green fluorescent protein) so I replaced GFP for RFP (red fluorescent protein) on the PI(4,5)P₂ biosensor, and inserted BFP (blue fluorescent protein) on the 5-HT₆ domain, allowing me to distinguish all three molecules in the same primary cilium. To do this, I removed the GFP sequence from our PI(4,5)P₂ plasmid using restriction enzymes that cut DNA then inserted RFP (amplified from a template plasmid carrying RFP) using DNA ligase. I confirmed the RFP insert by restriction enzyme digests specific for RFP and by direct DNA sequencing. PI(4,5)P₂-RFP plasmids were transformed into cells with PI(4)P-GFP and our BFP ciliary marker, then live-imaged. These tools will make it possible to determine if abnormal PI subtype distribution in primary cilia is a unifying cellular defect in JS patient cell lines. If so, we can then explore the effects of altered PI distribution and determine whether modulating PI distribution has the potential for mitigating the effects of Joubert syndrome.

Joubert syndrome (JS) is an autosomal recessive neurodevelopmental disorder, characterized by the "molar tooth sign" on axial brain MRI. JS is caused by mutations in 35 known genes, all of which encode proteins that localize to the primary cilium, a microtubule-based organelle that projects from the surface of most cells. Our current understanding of the underlying molecular mechanism causing JS involves lack of ciliary localization of ARL13B and INPP5E, two JS-associated proteins. ARL13B is required for the ciliary localization of INPP5E. Normal INPP5E localization maintains a phosphatidylinositol subtype distribution in the ciliary membrane. My research investigates ciliary phenotypes in cell lines harboring causal mutations in C2CD3, which encodes a protein that localizes to the primary cilium’s basal body, using existing images of patient cell lines. Loss of C2CD3 function in mouse models has presented lower ciliation rates and shorter cilia lengths. Previous research in our lab on two other JS-associated basal body proteins, OFD1 and KIAA0586, identified normal ciliary ARL13B-INPP5E levels. To determine ARL13B and INPP5E localization, cells from two control and two different C2CD3 patient cell lines were grown and serum-starved, inducing ciliation. Cells were stained with antibodies to acetylated tubulin (marking cilia), and INPP5E or ARL13B (marking protein of interest). Using Fiji, an image analysis software, I “painted” each cilium by outlining the signal in the acetylated tubulin reference channel to define a mask. Using that mask, I quantified ciliary ARL13B and INPP5E. I measured ciliation rates using the number of masks divided by the number of nuclei, and cilium lengths using the “skeleton length” function. Based on data from mouse models, we predict that C2CD3 patient lines will have fewer and shorter cilia, but normal ARL13B-INPP5E localization. These expected data would exclude the hypothesis that INPP5E mislocalization is an obligate part of the biological mechanism underlying JS.