2022 Fall Research Symposium
Course-directed Research
The following are descriptions of courses and research projects that were presented at the 2022 Jepson Science Center Research Symposium.
BIOL 322 Animal Ecology, Dr. Brad Lamphere
Animal Ecology studies how animals interact with their world and one another. Our lab exercises collect data on five topics ranging from ant foraging strategy to fish population estimation to invertebrate community diversity. For the lab final, students use one dataset to analyze and answer an original scientific question.
The following are the projects presented in this symposium:
- Poster 1: Does a fishes’ physiological temperature preference predict its population change in response to warm and cold years?
Tiffany Skrabenek - Poster 3: Impact of sampling method on the size ranges of fishes captured
Natalie Brennan, MC Woodrum - Poster 5: Habitat type influences diet specificity in an ant
Georgia Bowling, Mackenzie Dickson - Poster 7: When the humans are away, the fish will play? Evaluating the impact of COVID restrictions on stream fish populations
Caitlin Moore - Poster 9: Variation in stream depth promotes diversity of stream fishes
Anna Czernia - Poster 11: Does the presence of a predator reduce the diversity of prey taxa among soil invertebrates?
Hunter Jones, Natalie Loeffler - Poster 13: Impact of human land use on Opossum activity levels
Tamara Garrett - Poster 15: Testing the impact of microhabitat complexity on the diversity of ant species
Ella Peck - Poster 17: Role of body size in determining the food preferences among ant species
Aziza Alikhail, Tessa Lanzafame - Poster 19: Seasonal variation in the diurnal cycle of Gray Squirrels
Mina Murad - Poster 21: The availability of open-water habitat predicts the diet composition of American Alligators
Ellie Shanahan - Poster 22: How does the abundance of a native minnow correlate (or not) with that of a recently introduced species?
Erik Dale, Priya Patel - Poster 23: A comparison of the flight altitude and velocity of Black Vultures and Turkey Vultures
Eren Edwards, Faith Fraley
BIOL 432 Virology, Dr. Lynn Lewis
In this Research Intensive course, students are introduced to the major groups of viruses and their replication cycles, lab techniques for studying viruses and some of the new, emerging viruses. Students practice lab techniques for handling, growing and studying viruses during the first half of the semester, while designing an experimental research project based on their reading of primary literature. Students then carry about their research projects, in groups of 2 or 3, during the second half of the semester and present their collected data analysis.
The following are abstracts for the projects presented in this symposium:
- Poster 2: The effects of epigallocatechin-3-gallate (EGCG) in preventing infection of BHK-21 cells with Newcastle disease virus
Carly Gorham, Amberleigh Morris, Jordan Grinkewitz
Epigallocatechin-3-gallate (EGCG) is a green tea catechin that displays evidence for inhibiting viral attachment. EGCG has shown antiviral activities against both RNA and DNA viruses such as HCV, IAV, HIV, HSV, and HBV (Calland et al., 2012). The purpose of this research was to determine the extent to which EGCG could prevent Newcastle Disease Virus (NDV) attachment to baby hampster kidney cells (BHK-21) under varying time points including when introduced 1 hour prior to infection, at the same time of infection, and 1 hour post infection. If EGCG has antiviral capabilities, it will prevent NDV attachment to BHK-21 cells. To determine EGCG cytoxicity on BHK-21 cells, an MTT assay was performed. A plaque assay was performed in order to determine the antiviral effects of EGCG. When counting plaques, there were minimal absolute plaques able to be determined for all 3 trials and treatment groups. Due to the lack of staining present in most wells after performing the plaque assays, it is likely the viability of the BHK-21 cells was low which resulted in a poor rate of NDV infection. The agarose did not detach from the wells with ease, having likely disturbed the cells, which could have contributed to the low infection rate as well. Further testing is required to determine the capability of EGCG to prevent NDV infection of BHK-21 cells. - Poster 6: The Anti-Cancer Effects of Newcastle Disease Virus on HeLa Cells
Cidney Collins and Courtney Smith
We plan to investigate the area of cancer treatment and the use of viruses to suppress such cancer cells. If cancerous cells (HeLa) are infected with Newcastle disease virus (NDV), then NDV will selectively lyse HeLa cells and can induce apoptosis. NDV is recognized in clinical settings as an oncolytic virus because it selectively replicates in cancer cells and kills them. Death receptors and mitochondrial apoptotic pathways are triggered by NDV, so we believe the virus will have the same effect in HeLa cells. If NDV can selectively kill apoptosis-resistant (cancer) cells, NDV might be a promising cancer treatment. We plan to test our research question using similar strategies of previous studies by using an MTT assay to measure cellular metabolic activity as an indicator of cell viability, proliferation, and cytotoxicity. - Poster 10: Effects of Hydroxychloroquine on Autophagy Inhibition in Encephalomyocarditis Virus Infected Cells
Eliza Van Essendelft, Ryan Meek, Emily Sizemore
The focus of this project is to evaluate the effects of hydroxychloroquine (HCQ) on Encephalomyocarditis virus (EMCV) virulence. EMCV is a virus that infects a broad range of mammalian hosts and poses a potential threat to not only public health, but also the food industry, as domestic pigs are very vulnerable to this virus. EMCV has been found to induce autophagy in infected cells, and it was also discovered that autophagy was necessary for EMCV replication. Autophagy is a necessary cellular process that functions to recycle old proteins and organelles inside a cell by segregating them and allowing them to be broken down by lysosomes. This process is what we will be trying to inhibit with HCQ as a potential treatment of EMCV infection. HCQ, a drug currently utilized to treat malarial infections, is a lysosomal acidification inhibitor that has been shown to inhibit autophagy in cancer cells, but its application to viral infections is limited. Treatment of viral infection with HCQ will be quantified by plaque assay and inhibition of autophagy will be analyzed using transmission electron microscope (TEM). TEM will show presence of autophagosomes in HCQ treated and untreated cells and allow for visualization of inhibition. - Poster 14: Antiviral Effects of RGE on EMCV
Jessica Mimms, Mary Williams
Red ginseng extract (RGE) has been explored for anti-inflammatory, antiviral, and antioxidant properties against an array of viruses. In a study done where RGE was tested against respiratory syncytial virus (RSV), researchers found that RGE treatment inhibited RSV-induced cytopathogenic formation and replication in vitro (5). Based on these findings, we explored the effectiveness of RGE on the infectivity of encephalomyocarditis virus (EMCV) with the use of in vitro cell cultures of BHK-21 cells. We hypothesized that the cells pretreated with higher concentrations of RGE will possess antiviral effects and higher cell viability. We began testing this by growing and splitting BHK-21 cells in a 1:10 split. The dilutions used for RGE were 10-1,10-2, 10-3, and 10-4. The RGE dilutions and BHK-21 cells were then added to a 12-well plate and examined once confluent to ensure that RGE allowed for cell growth. The best dilutions that allowed for cell growth were 10-2, 10-3, and 10-4, which were then used in a MTT assay. The cells were pretreated with RGE dilutions and placed in a 96-well plate. Once cell viability was confirmed, diluted EMCV was added to the control wells and the remaining columns. The dilutions of EMCV used in each of the rows were 10-3 to 10-9. The plate was then interpreted by a spectrometer. The results indicated that the control wells, without RGE, had the highest metabolic activity. This indicates that there could be possible harmful effects of RGE towards the cells. We conclude that further research of the antiviral effects of RGE is required. - Poster 18: The Effect of Garlic, Onion, and Mushroom Extract on NDV in BHK-21 Cells Cytopathic
Asifa Mossavi, Kristine Dadufalza, Christina Phillips
Newcastle disease virus (NDV) is one of the most prominently damaging diseases for the poultry industry. There is a risk of contracting this disease for all birds. Vaccines are being used to prevent Newcastle disease. However, the effectiveness of the vaccine has been limited. In addition, the vaccine is only used for the prevention of the disease, not for treatment. Hence, this research focuses on the antiviral effects of garlic, onion, and mushroom extracts because they possess the qualities of preventing viral infection. The three chosen natural sources (onion, garlic, and shiitake mushroom) contain a wide range of bioactive compounds. These bioactive compounds allow for their antibiotic, anticancer, antioxidant, anti-inflammatory, and antiviral activities. In this procedure, a monolayer of BHK-21 cells was set up with 96-well plates and incubated. After a few days, garlic, onion, and shiitake mushroom extracts as well as NDV were added to the 96-well plates and its antiviral effect was determined by performing an MTT assay to detect its absorptive effect. The results from the absorptive assay showed that the onion and garlic extracts were the most effective since they led to a high cell viability. More testing will be done to support or reject these results. - Poster 20: Effects of Bleach Derivative ClO2 on EMCV-infected BHK-21 Cells
Erin Kenealy, Caroline Joyce, Zabdi Cayetano
Encephalomyocarditis virus (EMCV) is a positive sense, single-stranded non-enveloped RNA virus with a natural reservoir in rodent populations. This zoonotic virus is spread to domestic swine populations which causes widespread damage to industry. EMCV along with many viruses are known to spread through contaminated water sources. The treatment of potable water and wastewater often uses chemicals such as chlorine and chlorine dioxide (ClO2). which inactivate viruses in a variety of manners. In 2020, during the ongoing COVID-19 pandemic, ClO2 gained legal protection as elective treatment for viral infections of SARS-CoV-2. In this study, we sought to add evidence to the current medical understanding that the consumption or intravenous administration of bleach derivatives is harmful to cellular health and not beneficial to patients with viral infections. For this study we used Clidox-S, a chlorine dioxide based sterilant, on BHK-21 cells infected with EMCV to study the cytopathic effects of EMCV and our bleach derivative. MTT assays were run on multiple 96-well plates to assess appropriate concentrations of EMCV and ClO2 before ClO2 was added in combination with EMCV. Our results, gathered by MTT and TCID50, revealed that cells infected with EMCV and treated with ClO2 displayed more cytopathic effects than cells infected with EMCV alone. These results may indicate that the consumption or administration of bleach or bleach derivatives is actively harmful to virally infected cells and should not be a candidate for treatment, preventative, or therapy in a medical setting.
BIOL 472F Plant and Animal Interactions, Dr. Josephine Antwi
The course is designed to explore the fundamental concepts of the interactions between plants and animals, with specific focus on insects and plants. Students design various studies involving insect pollinators and the effect that urbanization hason pollinators. The primary objective of the course is to teach students the basics of experimental design and executing a research project through problem solving, critical thinking, and analyzing primary literature.
The following are abstracts for the projects presented in this symposium:
- Poster 4: The Effects of Shaded Habitats on Pollinator Species Richness and Diversity
Mackenzie Dickson, Georgia Bowling, Crimson Farina, and Natalie Brennan
This research aimed to observe pollinator diversity in varying light habitats by comparing two sites on the campus of the University of Mary Washington, one shaded and one non shaded. It is important to understand the ideal conditions for pollinator success in urbanized landscapes. Our field study consisted of sweeping 2 sites, during night and day, twice a week, for 8 weeks. One site was non shaded, receiving more sunlight, and contained mostly tall grasses, while the shaded site consisted of more trees and bushes. The specific goal of the study was to compare insect pollinator diversity among the two varying habitats to determine which set of conditions elicited higher species abundance and richness. Over twice as many pollinators were collected from the non shaded site than the shaded site. More pollinators were collected at night than daytime. Species diversity was higher in non shaded than shaded (Shannon-Weiner diversity index of 2.669 and 2.218, respectively) as night time with a diversity index of 2.69 (vs. 2.63 during the day). These differences were statistically not significant. The Jaccard Similarity index indicate that only 33% of species were shared between shaded and non shaded sites. Our study implies that there may be differences in species abundance and richness among habitats receiving varying levels of light. More data is needed from these sites in order to fully understand the effects of shading pollinator richness and diversity. - Poster 8: Butterfly Visitation on Four Autumn Flowering Plants
Danielle Cross, Krystal Lightell, Julenny Marte, Samantha Schwarting
The purpose of this study was to identify Lepidoptera foraging behaviors regarding the attractiveness of specific petal colors. This study aimed to use petal color to determine which common autumn flowering plants can be used to increase pollination by lepidopterans in urban gardens. Lepidoptera visits were recorded on four autumn flowering plants (Conoclinium colestinum, Anemone hupehensis, Symphyotrichum novae-angliae, and Helianthus angustifolius) at Kenmore Gardens located in Fredericksburg, Virginia. Both butterflies and plants were identified in the field using internet sources and field guides. A patch of each species of flowering plant was observed twice a week for one hour over five weeks. A total of 68 lepidopteran visits were recorded and identified down to the family level. 75.0% of lepidopteran visits were recorded on C. colestinum. The only three lepidopteran families observed were Danaidae, Hesperiidae, and Lycaenidae where 91.2% of visits were made by Hesperiidae. The lack of data prevented us from performing statistical tests and therefore, we could not conclude about how petal color affects lepidopteran visitation. - Poster 12: Determining Hymenoptera Diversity in Managed and Unmanaged Urban Landscapes
Aziza Alikhail, Curtis Kasiski, Audrianna Shepherd, Elizabeth Golden
In this study, we looked at the effect of managed landscapes on the diversity and abundance of insects in the order Hymenoptera. Today, humans are spreading out causing the mass destruction of the natural land, also known as urbanization. Urbanization has led to managed landscapes with aesthetic plants, which may not necessarily be beneficial to pollinators. In this, we collected insects from a managed and an unmanaged area at University of Mary Washington, Fredericksburg campus for two weeks. The managed area was a pollinator garden picked based on the number of plants in season and a no-mow zone was picked for the unmanaged land. Insects were identified to species level. We identified 15 Hymenoptera species at both sites with 6 species at the managed site and 8 species at the unmanaged site. This difference was not statistically significant (Chi-Square=10.33, 9 d.f., p=0.324). Species diversity was higher at the unmanaged than the managed area (Shannon-Weiner indices of 1.86 and 1.59, respectively). This slight difference in diversity could be the result of the higher plant diversity at the unmanaged area supporting more insect species. Given only one site per landscape type was sampled in this study, we would need to sample more sites the understand the effect of land management in urbanized areas on pollinators. - Poster 16: Impact of Urbanization on Moth Abundance and Diversity
Tessa Lanzafame, Cole Fincher, Angel Ramirez, Ibert Fancher
Urbanization changes the structure of natural habitats, affecting biodiversity. Moths play critical roles in ecosystems, such as pollinating plants and being prey for other animals. Urbanization often decreases moth numbers due to habitat reduction. However, light pollution is a strong attractant that can draw moths to urban areas, which can then impact their fitness. To aid moth conservation, we examined the impact of urbanization on moth abundance and diversity in urban and semi-urban areas. We collected moths from two urban areas in downtown Fredericksburg (Hurkamp Park and Kenmore Park) and two semi-urban areas on the UMW campus (behind the HCC and near the Eagle’s Nest), setting up a light trap consisting of a mercury vapor bulb pointed at a white sheet to attract moths. We sampled from one urban and one semi-urban site at night each week for six weeks, collecting moths and then identifying them to the family level. We found that the mean abundance of moths collected from the urban sites (1.33 ± 0.82) was lower than that of the semi-urban sites (2 ± 1.83). The urban sites were more diverse, as their combined Shannon-Wiener Diversity Index value was 1.21 compared to the semi-urban sites’ value of 0.76. However, calculating the Jaccard Coefficient of Community Similarity showed that the urban and semi-urban communities were similar in moth family composition (CCJ=0.75). Our results suggest that light pollution may not attract moths as strongly as predicted and that urbanization level does not seem to greatly influence moth diversity
Independent Projects
The following abstracts are projects presented at this symposium, separated by departmental affiliations:
Biological Sciences
- Poster 24: The COVID-19 Pandemic: How Has The Pandemic Affected Chronic Disease Care and Follow-Up
Author: Hope Grzebien; Research Advisor: Mr. Michael Stebar
COVID-19 first emerged in Wuhan, China in December of 2019 causing millions of people to become infected and thousands of deaths. Patients infected with the virus experienced a range of symptoms ranging from mild to severe with a large portion of the world population being asymptomatic carriers. Throughout the pandemic scientists observed a decrease in patients seeking medical care in both the emergent and non-emergent settings. There were a lot of journal articles showing this trend but many of them fail to explain why this trend occurred. Due to the lack of literature it was difficult to understand why patients would avoid seeking medical attention during the pandemic. The purpose of this literature review was to gather, examine, and assess the evidence that was available regarding the reasons why patients avoided seeking medical attention during the COVID-19 pandemic and the potential repercussions of said avoidance. It was found that the main reason patients avoided seeking medical care during the pandemic was due to the fear of being exposed to and potentially becoming infected with COVID-19 while seeking medical attention. Some other reasons that were found included misinformation about COVID-19, lack of social support, and large economic burden of seeking medical care. All of these factors led to patients avoiding medical care and delaying the best opportunity for treatment, resulting in negative health outcomes. Unfortunately, since the pandemic is still on-going, we will not be able to fully understand the lasting effects of the pandemic for many more years. - Poster 28: Localization of Transgenes for Drosophila Models of Myotonic Dystrophy Type 1
Authors: Andrea Waltrip, Shyanne Michael, Delaney Baratka, Madeline Brunt, Charlotte Russell; Research Advisor: Dr. Ginny Morriss
Myotonic Dystrophy Type 1, DM1, is a multi-systemic disorder that results from expression of expanded CTG repeats in the DMPK gene in humans. Three transgenic Drosophila melanogaster lines have been created containing 60, 250, or 480 CTG repeats to model DM1. The transgenic repeats are expressed using the GAL4/UAS system. Expression of long-repeat transgenes ((CTG)250 and i(CTG)480) produces phenotypes consistent with DM1, relative to control lines ((CTG)60). The precise chromosomal location of insertion of the transgenes has not been reported. We are using both classical genetic and molecular approaches to localize CTG-repeat transgene insertion into the genome. To narrow down insertion location to a specific chromosome, we used GAL4 drivers on different chromosomes to drive expression of repeats and assessed phenotypic ratios of eye color, climbing capability, flight ability, and muscle degeneration, which is affected in DM1 flies. Results from the genetic analysis suggest that the (CTG)250 and i(CTG)480 transgenes are likely localized to chromosome 2 and the (CTG)60 transgene is likely localized to chromosome 3. We will confirm our chromosome localization using fluorescent in situ hybridization (FISH) of polytene chromosome preparations, using transgene-specific probes and comparing the hybridization location to regions that hybridize chromosome-specific probes. FISH will allow us to further narrow down the location of transgene insertion, allowing targeting of smaller regions for sequencing to determine the exact insertion site. Knowing the location of the transgenes can allow for more practical mating schemes to study DM1 disease mechanisms, as well as provides crucial information for understanding transgene expression. - Poster 29: Triggering Apoptosis in Jurkat Cells with Proton Pump Inhibitors (PPIs)
Author: Kaitlin Saal; Research Advisors: Dr. April Wynn, Biology and Dr. Randall Reif, Chemistry
Proton pump inhibitors, also known as PPIs, often trigger apoptosis, or programmed cell death, by disrupting proton pump function and interfering with pH regulation that typically occurs within a cell. In this experiment, the effect of omeprazole, a known gastric reflux drug and PPI, specifically on the viability of Jurkat cells was examined. The cells were grown under standard conditions and stained with calcein AM to differentiate between healthy and dead cells. Three trials of each of the experimental groups (negative control, positive control, and omeprazole) were conducted. The negative control contained no drug, and the positive control included doxorubicin, a known chemotherapy drug. Pictures were captured using an inverted fluorescent microscope at 0, 6, 18, 21, 24, 27, and 30 hours, and Image J was used to calculate the means and standard deviations of cell size to estimate cell viability. While there was significant difference in the percent viability between the negative and positive controls, the paired t-test for sample means at time t=30 hours between the negative control and omeprazole of 0.1635 supports the null hypothesis and assumes statistical insignificance. Nevertheless, other PPIs are still being investigated to determine their effect on cell viability. - Poster 31: HSP90 and Triglyceride Levels in Partially Migratory Canada Geese
Author: Audra Cote; Research Advisor: Dr. Andrew Dolby
The Canada Goose (Branta canadensis) is a partial migrant species. Migratory geese fly to a variety of breeding grounds in North America and residents stay behind. The physiological costs and benefits of being a migratory versus resident Canada Goose has received little attention. In this study, I will examine the physiological differences between resident and migrant Canada Geese using HSP90 and triglyceride levels. HSP90 is an oxidative stress indicator, and it will help us compare stress between populations. Triglyceride tests will examine excess fats and potential obesity in resident populations possibly based on a more sedentary pattern of activity and diet. My prediction is that there will be a difference in HSP90 and triglyceride levels between resident and migrant Canada Geese populations, with high HSP90 associated with migratory and physiological stress and high triglyceride levels associated with a more sedentary activity level. I will collect data on HSP90 and triglyceride levels in both migratory and resident Canada Geese specimens donated by hunters in the Fredericksburg area. Body length measurements will be used to assign geese to migrant and resident categories. Assays on samples have been completed for triglyceride tests and will be available soon and graphs for these will be completed by the symposium as well as the HSP90 ELISA test. As this is an ongoing research project, we will add to current data in the spring with more samples and will continue to run Triglyceride and HSP90 tests on new samples. Data will be available for the symposium. - Poster 34: The Effects of the Estrous Stages on Voluntary Wheel Running and Anxiety in Female CD-1 Mice
Authors: Abigail Algeier, Emily Landry; Research Advisor: Dr. Parrish Waters
Most non-human female mammals, including mice, experience an estrous cycle, a regular hormonal release cycle following patterns similar to the menstrual cycle that maintains reproductive function and behavior. There are three stages or phases to the mouse estrous cycle: diestrus, proestrus, and estrus. Because these phases have a similar hormonal progression to the menstrual cycle, mice are an ideal model to study female reproduction. We asked the question: does the phase of estrous impact the amount of exercise, and does the exercise retain its anxiolytic properties? In this pilot project, we organized 15 CD-1 female mice into three groups of five representative of each estrous phase. We allowed the mouse groups to run on wheels only when in the appropriate phase of estrous. We tracked estrous by performing vaginal lavages and examining collected cells under a light microscope. We then used the wheel running data collected over 5 weeks to compare the distance run by each estrous group. We analyzed the data and decided to modify the experiment to include more animals per estrous group for better results. - Poster 36: Dietary Diversity of Bees in the Genus Bombus along an Urbanization Gradient
Authors: Curtis Kasiski, Eren Edwards, Harrison Miles; Research Advisor: Dr. Josephine Antwi
As land use change continues at a rapid pace, it is increasingly important to understand how such environmental alterations influence beneficial insects, including pollinators. In eastern North America, bumble bees, are an important group of pollinators within managed and non-managed ecosystems. Here, we investigated changes in dietary diversity and niche overlap across common bumble bee species along an urbanization gradient: highly urban, suburban, and rural. We caught 126 bumble bees belonging to B. griseocollis, B. impatiens, and B. bimaculatus. Bombus impatients seems less abundant in urbanized areas than in rural and suburban areas. We were also able to successfully amplify pollen collected from all three Bombus species. In the next phase of this study, we plan to use next generation sequencing to identify dietary diversity. - Poster 38: The effects of nutrient pollution on macroinvertebrate communities in Accokeek Creek and Potomac Creek
Author: Mika Bishton; Research Advisor: Dr. Abbie Tomba
Nutrient pollution is a growing issue in freshwater streams. Agriculture practices such as fertilization contribute to excess nutrients entering and polluting water systems. Tidal streams are used as feeding and spawning grounds for large biodiversity of organisms. These tidal streams are more susceptible to pollution, making them useful water quality indicators for larger watersheds. Macroinvertebrates are good bioindicators of stream health because they are accessible, sensitive to environmental changes, and taxa can be organized based on pollution tolerance. Accokeek Creek is a forested stream located within The Crow’s Nest Nature Preserve. Potomac Creek is a neighboring stream surrounded by agricultural land. In this study, we compare macroinvertebrate assemblages in Accokeek Creek and Potomac Creek to study the impacts of agricultural activity to better understand the relationship between nutrient pollution and macroinvertebrate community structure. To obtain macroinvertebrates, sediment samples were collected along the streams. Organisms were identified to the family level with the exception of Oligochaeta. To measure diversity, the Shannon-Wiener Index will be calculated. Water quality parameters including temperature, pH, electroconductivity, and dissolved oxygen were measured at each site. Nitrate and orthophosphate levels were analyzed at each site to determine nutrient contamination. We predict Potomac Creek will have higher nutrient pollution contamination than Accokeek Creek. If this were true, we can expect lower diversity in Potomac Creek with more pollutant tolerant taxa present compared to Accokeek. - Poster 41: The Effect of Multi-Phage Resistance Mutations in Bacillus thuringiensis subsp. kurstaki on Virulence to Manduca sexta Larvae
Author: Marianne Beaulieu; Research Advisor: Dr. Lynn Lewis
Antibiotic resistance has led to the rise of several dangerous and difficult to treat diseases, such as MRSA infections. The number of antibiotics effective against resistant bacteria are dwindling, so the solution may lie in other bactericidal agents. Phage therapy is the practice of treating bacterial infections with bacteriophages, viruses pathogenic to bacteria. This therapy is promising for a number of reasons; phages are naturally occurring in abundance, they are reproduced by the bacteria they infect, and they are capable of mutating to evade bacteria’s defenses. However, bacteria are also capable of mutating to evade phage infection. Bacterial resistance to phage infection does not necessarily carry the same implications as bacterial resistance to antibiotics. Unlike with antibiotic resistance, the mutation battle between bacteriophages and the bacteria they infect is on-going. Furthermore, there is evidence to indicate that some bacteria may pay a heavy price for resistance to phages, to the point where they may no longer be capable of causing disease in a host. This idea forms the basis for this research.
At the University of Mary Washington, the phage hunters program isolates phages pathogenic to Bacillus thuringiensis subsp. kurstaki (Btk). Btk is a common bacteria found in soil and is used as a pesticide for its pathogenicity to lepidopterans. This research will involve isolating multi phage-resistant strains of Btk and testing how the phage resistance affects its pathogenicity by inoculating Manduca sexta larvae, and observing how many, if any, survive. - Poster 42: Characterization of Two Novel Calcium Regulator Proteins in Toxoplasma gondii Growth and Invasion
Authors: Emily Sizemore, Abby Delapenha; Research Advisor: Dr. Swati Agrawal
Toxoplasma gondii is an opportunistic apicomplexan parasite infecting humans and livestock. Infection in immunocompromised individuals can cause neurological damage and infection during pregnancy can lead to fetal death. These parasites engage in a complex life cycle, involving repeated invasion of host cell and egress from the host cell. Calcium signaling is an important regulatory mechanism for many essential processes in the parasite including gliding motility (actomyosin-dependent mode of motion), invasion, and egress. Our work focused on two previously uncharacterized calcium regulator proteins. The proteins of interest were modified using the CRISPR-Cas 9 system to express the Auxin Degron system downstream of each gene. Our work demonstrates the localization of these proteins and the role of these proteins on parasite growth and fitness. - Poster 43: Differential Gene Expression in Myotonic Dystrophy
Author: Anna Harris; Research Advisor: Dr. Ginny Morriss
Myotonic Dystrophy type 1 (DM1) is a multisystemic disorder that decreases muscle function. Expansion of CTG repeats in the 3’ untranslated region of Dystrophia Myotonica-Protein Kinase (DMPK) gene is ultimately responsible for the skeletal muscle wasting phenotype in DM1. Using Gel electrophoresis, PCR, and qPCR the relationship between myokines and their role in DM1 were studied. RNA samples from mice were obtained and used to synthesize cDNA through DNase treatment and PCR. These samples were tested using gel electrophoresis to confirm adequacy. Myokine expression was then tested via qPCR and four genes: ActB, Cx3Cl1, TNFa, and IL6. Through analysis of these techniques, Cx3Cl1 and IL6 had results that were inconclusive. ActB and TNFa showed diverse amplification – ActB having minimal and varied amplification while TNFa displayed higher but more consistent amplification. These results indicate ActB and TNFa have a relationship with myokine expression that could be evaluated in further studies. Future studies will be conducted using the same methods and experiment with alternative methods to explore the role myokines play in DM1 related skeletal wasting. - Poster 44: An Inquiry into the Validity of the Tube-Test as a Measure of Dominance in Mice
Author: Tim Philbeck; Research Advisor: Dr. Parrish Waters
Mice are social animals, and interactions among individuals can provide valuable information related to behavioral and physiological processes. To better understand social relationships in mice, the Tube-Test was developed to easily measure behavioral dominance in cohorts of mice; although this method is not universally accepted as a reliable measure of social dominance, it holds the benefit of being rapid, low stress, and providing an objective measure of dominance. To address the controversial validity of the Tube-Test and to enhance our ability to discriminate dominant mice in social groups, I compared results from the Tube-Test to home-cage behavior, preputial gland size, and steroid hormone levels, all of which are more universally accepted (but more labor intensive) indicators of social dominance in mice. I housed mice in dyads and assigned them social ranks (i.e. dominant or subordinate) based on their proportion of wins during the Tube-Test (n = 6 dyads). Social rank influenced the duration of total aggression (t = -18.42, df = 4, p ≤ 0.05), although subordinate mice exhibited higher levels of aggression. I used Wilcoxon rank sum tests to compare corticosterone concentration and preputial gland size. Social rank did not influence either of these measures (corticosterone: W = 6, p = 0.7; preputial gland: W = 3, p = 0.7). My results from this pilot study suggest that the Tube-Test does not represent an effective method to measure dominance-like behavior or physiological changes in laboratory mice, although I am continuing this work with an additional cohort of mice. - Poster 45: Treatment of MRSA with Phage Cocktail
Author: Skylar Houston; Research Advisor: Dr. Lynn Lewis
A focus on phage therapy has increased in popularity within the western hemisphere over the last few years with the rise of antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). Bacteriophages are a type of virus that infect a specific bacterium. The bacterial host’s replication machinery is used for viral replication and once the virus has replicated sufficiently the bacterium is normally lysed. The focus of this research is on the preparation and use of phage cocktails to treat Staphylococcus aureus infections. Phage cocktails involve the use of multiple bacteriophages to attack the bacteria, and are often touted as being more effective than use of monophage therapy. The goal of this study is to isolate several phages for use to develop an effective phage cocktail for use against Staphylococcus aureus. Purification and isolation will be done by standard procedures. Following this, high titer of the phages will be made and used to make different formulations of a phage cocktail. To assess effectiveness, both comparative spot plates and time kill assays will be used. This will be compared to an antibiotic commonly used to treat Staphylococcus aureus infections. - Poster 46: Targeting Novel Apoptosis Genes in Leishmania tarentolae Using CRISPR-Cas9 System
Author: Caroline Beasley; Research Advisor: Dr. Swati Agrawal
Leishmania is a unicellular parasite transmitted to humans through the bite of a sandfly. Recently, a protocol for the CRISPR-Cas9 system, a gene editing tool, has been developed for Leishmania, allowing for the tagging or knockout of specific genes. In this study, we targeted two genes: PF16, coding for a known flagellar motility protein, and PGAM5, coding for a protein potentially involved in apoptosis in Leishmania. By observing the effects of the knockout of these genes, we will better understand their function. To start we identified ideal conditions for growth of Leishmania tarentolae with Cas9. We then prepared blasticidin and puromycin repair cassettes and single guide RNA (sgRNA) for PF16 and PGAM5 respectively for transfection and use of CRISPR-Cas9. To culture the parasites, we compared growth in Minimum Essential Media (MEM) and Brain Heart Infusion (BHI). Cas9 expression in our Leishmania was associated with a hygromycin resistance gene, so hygromycin was added to media as a selective pressure for Cas9 cell lines. When the parasites reached a high density, we transfected with PGAM5 and PF16 cassettes and sgRNA. We found that L. tarentolae grew to a higher concentration in MEM than in BHI. The Cas9 gene was conserved in the parasites, indicating that hygromycin selective pressure was effective. The transfected parasites are currently under selection with Blasticidin and Puromycin, and will be screened for correct insertion. The procedures used in this study to culture and Leishmania will allow further investigation of the role of PGAM5 in apoptosis in Leishmania. - Poster 47: The Effect of Social Isolation on Depression-like Symptoms in Male Mice
Author: Dylan Crann; Research Advisor: Dr. Parrish Waters
Humans who experience social isolation are at risk of developing depressive disorders, which are typified by decreased energy expenditure, increased food consumption, and forgetfulness. Two physiological systems that influence depression in humans are the neurotrophin, BDNF, and the glucocorticoid, cortisol. These ligands are disrupted in humans with depression disorder and are implicated in stress-related behavioral changes in mice. This study combines behavioral and physiological approaches to understand the effects of social isolation in a model organism. As social isolation becomes more common in our society, it is more pressing to understand how it may influence our behavior and physiology and can lead to pathological states. I hypothesize that social isolation will increase the expression of depression-like symptoms in mice. To model activity, we measure total running distance, running speed, and circadian running. Energy expenditure can be monitored through changes in total body mass and food consumption. Memory tests such as the Barnes maze and the novel object recognition provide measures of separate modes of memory that are associated with human depression. Finally, in our lab, we have developed protocols to measure levels of BDNF and corticosterone, the cortisol equivalent in mice, using commercially available ELISA assays. I expect socially isolated mice to have higher body mass, lower measures of running activity, and lower scores on memory tests. I also expect socially isolated mice to exhibit higher levels of corticosterone and lower levels of BDNF compared to social mice. - Poster 48: Endothelial Tube Maintenance & Analysis in a Cell Culture Model for Myotonic Dystrophy Type 1
Authors: Jada Gundy, Arshpreet Brar, Samantha Schwarting; Research Advisor: Dr. Ginny Morriss
Myotonic dystrophy type 1 (DM1) is a multi-systemic condition that results in severe muscle weakening and wasting. DM1 is caused by an expanded region of CTG repeats in the 3’ untranslated end of the DMPK gene. A previous study showed angiogenesis as a major process affected in DM1 mice that displayed muscle wasting as angiogenic genes and myokines were affected in response to repeat expression. Human umbilical vein endothelial cells (HUVECs) were used as the model for DM1 vasculature and transfected with DMPK containing 960 CUG repeats or DMPK with 0 repeats. These cells were then imaged every three hours for 24 hours. Endothelial tube length and width were quantified using ImageJ. Endothelial tubes mock transfected showed little to no degradation over the 24 hour monitoring period. Endothelial tubes transfected with DT0 showed some tube degradation upon visual analysis with tube narrowing. Endothelial tubes transfected with DT960 showed severe tube network degradation in tube narrowing and tube shortening. - Poster 49: The Effect of Fluorouracil on Pathogenic and Nonpathogenic Oral Microorganisms and Microbial Interactions with Restorative and Preventative Measures
Author: Valeria Ortiz Jimenez; Research Advisor: Dr. Lynn Lewis
Concerning the oral flora, chemotherapy compromises the patient’s oral health through dysbiosis of oral microbiota and increases the prevalence of dental caries, gingivitis, oral mucositis, and xerostomia. This research aims to evaluate the effect of a common chemotherapeutic agent, Fluorouracil (5-FU), on certain microorganisms that are common within the oral cavity. The 5-FU is typically given intravenously and when it reaches the oral cavity, the dosage is significantly reduced. Therefore, varying concentrations (50 mM, 75 mM and 100 mM) of 5-FU will be used to simulate this. The microorganisms tested will be Lactobacillus rhamnosus, Streptococcus mutans, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. These are some of the most common ones found in the diverse oral microbiota and would, therefore, be beneficial to study. They are also associated with different oral conditions like periodontitis, the progression of caries and lesions, and inflammation. There are topical and oral products that can be applied or consumed in order to prevent the overgrowth of certain bacteria, while also protecting the tooth surface and gums. In evaluating the effect of 5-FU on the microorganisms, different restorative and preventative treatments will be tested in order to reduce and/or improve their effect on a patient’s oral cavity. Thee products include chlorhexidine, fluoride varnish, amoxicillin, penicillin and saltwater. - Poster 50: The effects of social isolation on GRIN2B NMDA-R in PFC of CD-1 mice
Author: Jessica Mimms; Research Advisor: Dr. Parrish Waters
Social stability is critical for the well-being of an individual animal. Unstable environments, where socialization is limited, can serve as a risk factor for the development of psychiatric disorders, including depression and anxiety. In social interactions with rodents, glutamate was found to interact with NMDA receptors to modulate social memory. This compelled us to examine how socialization and the lack thereof, may influence glutamate in the medial prefrontal cortex of mice. The medial prefrontal cortex plays an important role in social responses and behavior. We will also investigate the corticosterone levels of rodents to determine how stress and social behavior are related.
Earth and Environmental Sciences
- Poster 26: Preliminary Survey of Total and Bioavailable Concentrations of Trace Metals in Surface Soils in the Kingston, Jamaica, Region
Authors: Faith Jones, Anna Velardi, Katherine Cook; Research Advisor: Dr. Melanie Szulczewski
This study investigated background levels of concerning metals in a variety of soils in and near Kingston, the capital of Jamaica. Minimal soil sample collection and analysis had occurred since a 1988 island-wide geochemical survey revealed very high concentrations of total Cd in many regions, along with elevated concentrations of As, Cu, Zn, and Cr in some types of soil, with background lead levels elevated only at specific polluted sites. An updated examination was deemed important due to a growing city population, increased fuel combustion, and intensive urban gardening. This study analyzed soils collected in 2022 for total metal concentrations, as well as bioavailable concentrations, previously only reported for lead. The various soils sampled from this urban and suburban region of a tropical country provided interesting results regarding metal content, with the arsenic and cadmium results of most concern. - Poster 30: Assessing the Presence and Concentration of Trace Metals in Surface Waters, Aquatic Plants, and Fish Adjacent to a Virginia Coal Ash Repository
Author: Carolyn Willmore; Research Advisor: Dr. Tyler Frankel
Coal ash (CA) is an industrial waste that has been shown to contain several neurotoxic trace metals including cadmium, arsenic, mercury, and lead. These contaminants are then able to leach into surrounding waterways and cause undesirable ecosystem effects. According to the Virginia Department of Environment, there are currently twenty-eight CA repositories that are situated near waterways which act as tributaries for the Chesapeake Bay, many of which are located adjacent to coal-fired powerplants. While previous studies have examined the presence and concentrations of these trace metals in surface water and sediments surrounding these industrial sites, our understanding of whether these trace metals bioaccumulate in aquatic flora and fauna inhabiting these waters remains relatively poor. As such, this study examined the presence and concentration of twelve different trace metals (Al, As, Cd, Ca, Cr, Cu, Fe, Pb, Mg, Mn, Se, Zn) in plant and fish tissues collected near the Possum Point Powerplant (Dumfries, VA). Male and female Banded killifish (Fundulus diaphanus) were collected from each site and epaxial muscle, gonads, and brain tissue collected via gross dissection. Whole hydrilla spp. were collected from each site. All collected samples were then oven-dried and trace metals extracted using 65% nitric acid, 30% hydrogen peroxide, and heat. Once extracted, concentrations of each metal were assessed using ICP-OES. While this study is still ongoing, we expect to find elevated concentrations of several neurotoxic trace metals in fish and plants collected adjacent to the plant compared to associated water and sediment samples, with increased bioconcentration exhibited by Hydrilla spp. The results of this study will provide a more detailed understanding of the large-scale impacts of this coal ash repository on adjacent waterways via bioaccumulation and serve as support for future studies examining impacts on higher tropic levels. - Poster 32: Calibrating a Multi-Coral Genus Approach for Reconstructing Central Tropical Pacific Climate
Author: Jacob Cantor; Research Advisor: Dr. Pamela Grothe
Centuries-long high-resolution climate records from the equatorial Pacific are vital to understanding the anthropogenic influence on tropical climate and validating future climate predictions in a warming world. Since instrumental records of climate only span through the mid-20th century, scientists use paleoclimate proxies from coral, or natural archives that capture climate conditions in their geochemistry, to reconstruct temperatures beyond the instrumental era. However, typical tropical Pacific paleoclimate studies are limited to one coral species, Porites, making it challenging to complete a centuries-long record of climate due to limited availability of samples. Here, we test the reliability of two new coral species, Favia and Hydnophora microconos, as recorders of climate in order increase the available archive to reconstruct a continuous 200-yr long climate record of the central tropical Pacific. Both living and fossil coral skeletons were collected from Kiritimati Atoll, central tropical Pacific, between 2014 and 2018 and were cut into 1-mm thick slabs, x-rayed, and drilled every millimeter along the main growth axis for geochemical analysis – δ18O and Sr/Ca – the gold standard for sea surface temperature (SST) reconstructions in corals. Initial results suggest that the δ18O timeseries from modern Favia closely resembles in-situ SST and δ18O records from Porites, suggesting it is an excellent recorder of SST. Future work will focus on δ18O and Sr/Ca records from modern Hydnophora microconos. If also proven reliable, then geochemical records from fossil Favia and Hydnophora microconos coral will be essential for completing a continuous 200-yr long record of central tropical Pacific climate. - Poster 35: Spatial analysis of dam sediments and trace metals contamination in the North Nashua River basin
Author: Jack Lanier; Research Advisor: Dr. Ben Odhiambo Kisila
Fitchburg, Massachusetts is a heavily industrialized city with over 20 dams located within the North Nashua River basin. Many of the dams, which were constructed in the mid- to late-1800’s, are abandoned. Metal fluxes and accumulation in fluvial ecosystems reflect natural weathering and associated sediment fluxes from the basin; but in most cases this process is exacerbated by the progressive anthropogenic land-use intensification with human population increases. It is well established that sediments trapped behind dams are a sink for contaminants from various land uses, known point sources, and atmospheric deposition. Therefore, spatial analysis of sediments behind multiple dams at high resolution in a single basin enables characterization of the dynamics between modern urbanization and legacy industry. This study seeks to characterize the spatial variability of metal concentrations in sediments behind multiple dams on the North Nashua River in order to infer the impact of land use and legacy industry on fluvial systems. Data collection consisted of multiple sediment cores and grab samples from seven dams in upstream to downstream locations along the North Nashua River. Samples were prepared using the aqua regia digestion method (USEPA 3050B) and were analyzed using an inductively coupled plasma mass spectrometer (ICP-MS) to determine metal concentrations in the surficial and core sediments of North Nashua River Basin. Preliminary results from trace metals enrichment analysis indicate significant to extreme enrichment of arsenic, cadmium, and lead, and low enrichment of copper and zinc. Specifically, As ranges from 1-15, Cd 1-250, Pb 1.5-15, Cu 0.1-6, and Zn 0.9-11. Initial hotspot analysis shows the greatest concentrations of metals in the south-central region of the study area; located adjacent to the town of Fitchburg and at the confluence of several sub-basins into the North Nashua River. Further Principal Component Analysis and other statistical analyses will elucidate the role of legacy sediments and contemporary land-use intensification in influencing metal distribution and loading in the North Nashua River Basin. This knowledge will provide a base for future research relating to contamination from the region’s industrial legacy and aid in any potential future remediation activities. - Poster 37: Assessing the Impacts of Two Coal Ash- Associated Trace Metals on the Viability, Locomotor Behavior, and Embryonic Development of the Freshwater Snail Planorbella Duryi
Author: Talia Tanner; Research Advisor, Dr. Tyler Frankel
Coal ash (CA) has been shown to contain several neurotoxic trace metals which are able to escape into local aquatic environments via accidental release, leaching from lined or unlined repositories, and permitted discharge. While previous studies have mainly focused on the impacts of these contaminants on freshwater teleosts, little is known about their effects on non-model aquatic invertebrate species. As such, this study assessed the exposure effects of two CA-associated trace metals, cadmium and arsenic, on the viability, locomotor behavior, and embryonic development of the Seminole ramshorn snail (Planorbella duryi). Exposure treatments were prepared at 0, .01, .1, 1, or 10 mg/L for each contaminant using either CdCl2 or Na2HAsO4 7H2O and concentrations confirmed using ICP-OES. Individual adult P. duryi were placed into separate 400mL beakers and exposed for 10 days, during which viability was assessed every 24hrs. Locomotor behaviors were recorded on days 1, 5, and 10 and analyzed using automated behavior software (ToxTrac v2.97) to assess differences in average speed, acceleration, distance travelled, and time spent immobile. Newly laid (<6hrs old) embryonic clutches were obtained from a breeding colony. Individual embryos were then isolated from each clutch, placed into separate glass petri dishes containing a given treatment, and checked daily for embryonic development stage and hatching success. While this study is currently ongoing, we expect to find dose-dependent decreases in locomotor behavior and delays in development for both trace metals, with viability being the least sensitive endpoint of those tested. Our results will provide novel information regarding these contaminants which will enhance our understanding of their impacts on invertebrate populations that inhabit CA-contaminated waterways. - Poster 39: The Presence, Distribution, and Concentration of Trace Metals in Surface Waters and Sediments Collected Near a Virginia Coal Ash Repository
Authors: Elizabeth Tyler, Rachael Harrington; Research Advisor: Dr. Tyler Frankel
The Chesapeake Bay watershed contains several coal-burning power stations located along its waterways. Coal ash, one of the largest forms of industrial waste, is primarily produced by power stations and disposed of in coal ash repositories. Known to be heavily enriched with trace metals, these contaminants are then able to enter surrounding aquatic environments. Few studies have examined trace metal contamination within the Potomac-Shenandoah watershed stemming from these repositories. Thus, the goal of this study was to assess the spatial and temporal distribution of trace metals in sediments adjacent to the Possum Point power station (Quantico, VA). Sediment samples (grab and core) were collected from several sites upstream, midstream, and downstream from the station. Trace metals from each sample were extracted and analyzed using ICP-OES (inductively coupled plasma optical emission spectroscopy) for the presence and concentration of Al, As, Cd, Ca, Cr, Cu, Fe, Pb, Mg, Mn, Se, and Zn. Cores were sectioned at 2cm intervals and sediment chronology established using 210Pb. While this study is still ongoing, we expect to find elevated concentrations of these metals midstream and downstream from the power station. Based on chronological data, we also expect to observe enriched trace metal deposits that occur after the coal ash repositories were created. This study will provide vital information regarding the prospective impacts of coal-burning repositories on the release and mobilization of trace metal contaminants within aquatic ecosystems in the Chesapeake Bay region.
Chemistry and Physics
- Poster 25: Apoptosis Induction in Jurkat T Lymphocytes by Proton Pump Inhibitors (PPIs)
Author: Shreya Murali; Research Advisor: Dr. Randall Reif, Chemistry
Apoptosis, commonly known as programmed cell death, constantly occurs in humans. In healthy cells, proton pump proteins allow for H+ ions to permeate cellular membranes, regulating pH levels. However, proton pump inhibitors (PPIs), such as omeprazole, prevent proton movement, resulting in pH regulation limitations. As the cell increases in acidity, apoptosis is induced. In previous studies, omeprazole induced cell death in Jurkat T-Lymphocytes; however, there was no confirmation of whether the cells died through apoptosis, or through necrosis, where the cell bursts. In order to measure the extent of cell death, cytosolic esterase activity was measured by staining cells with Calcein-acetoxymethyl (AM) dye. Jurkat cells were exposed to PPIs omeprazole, dexlansoprazole, and esomeprazole for six-hours, and monitored for 30 hours to measure viability. Doxorubicin, a known chemotherapeutic, was also used as a positive control when testing viability. When imaged using fluorescence microscopy, if cells fluoresced, they were deemed viable, while nonfluorescent cells were deemed necrotic. At the 30-hour mark, dexlansoprazole had least viability (39.95 +/- 3.52%), followed by doxorubicin (62.86 +/- 1.80%), esomeprazole (66.24 +/- 1.59%), and omeprazole (69.29 +/- 2.01%), in comparison to the negative control (71.54 +/- 1.11%). The low viability of dexlansoprazole indicates the need for a toxicity study using the same PPIs and exposure methods, to determine the optimal drug concentration. Future studies include the use of Annexin V-FITC and propidium iodide (PI) dye to determine the ability of the PPIs to induce apoptosis. - Poster 27: A Quantum Rattleback Effect in Rotationally Asymmetric Molecules
Author: Madeline Killian; Research Advisor: Dr. Varun Makhija, Physics
The rattleback is a boat shaped toy with a non-uniform mass distribution. As a result, its principal axes of rotation do not coincide with geometrical symmetry axes. A rattleback exhibits unidirectional rotation when spun about a symmetry axis. Here we computationally investigate the rotational dynamics of C2H3Cl after interaction with a non-resonant, femtosecond laser pulse. C2H3Cl lacks an axis of rotational symmetry, as a result of which the principal axes of its moment of inertia and polarizability tensors do not coincide. The interaction with the laser pulse torques the molecule about the principal axes of the polarizability tensor, initiating rotation that is not about any one of the principal axes. We compute the time evolving probability distribution of molecular axes during and after this interaction by solving the Time Dependent Schrodinger Equation in the rigid rotor approximation. This probability distribution evidently exhibits a unidirectional rotational motion about the most polarizable molecular axis, similar to that of the classical rattleback. The effect can be traced back to Raman transitions occurring during interaction with the laser pulse that change the parity of K the projection of the rotational angular momentum on the most polarizable axis. - Poster 33: Solar powered phone charging stations for the homeless population
Author: Kevin Leong, Research Advisor: Dr. Desmond Villalba, Physics
We are building phone chargers powered by an array of solar panels for the homeless population. Smartphones have become implemented and almost essential for life in our society, everyone has one including those who are homeless. Unfortunately, some homeless people are unable to charge their phones, therefore, we are creating a way for them to do that in a cost efficient way for everyone. Creating this prototype had four big focuses: 3D printing, creating circuits, programming the circuits, and angling our solar array towards the sun. We have been able to create a circuit that can generate enough power to charge a phone, and we are programming our circuit to use that power for charging purposes. We then have been able to 3D print a container for our solar array and wiring and angle it where it would be the most efficient at producing energy. Results from our project show that we have been able to power an Arduino board with solar power, and the optimal angle at which the solar panels will collect the most energy at our location in the Summer is approximately 10 degrees and South facing. - Poster 40: Quadratic programming for generating minimized weight matrices for pre-optimized neural networks
Author: Clark Saben; Research Advisor: Dr. Varun Makhija, Physics and Dr. Tirthabir Biswas
We are finding alternative expressions that produce the same result as a neural network and comparing how each performs on new data. A neural network (NN) is a mathematical expression that can be composed of linear and nonlinear transformations (often referred to as a computation graph). A NN must also be differentiable in order for gradients to be calculated for each transformation inside of the computation graph. By process of stochastic gradient descent (SGD) w.r.t a variable in the computation graph known as a weight(s) to minimize a loss function (in a process known as training), a NN can be grafted to act as a predictive algorithm for some input signal. Weight variables after gradient descent generate reproducible outputs on input signals used during training. We introduce quadratic programming with constraint conditions to generate new weight variables that produce the same output from the input signals used in training. We compare the performance of the NN using each set of weight variables on new data.
