Life Sciences Commons^™

Astrocyte Spatial Distribution Affects Growth Dynamics Of Breast Cancer Brain Metastases: An Agent-Based Modeling Study, Rupleen Kaur

Biology and Medicine Through Mathematics Conference

No abstract provided.

Tracking Food Quality In Algae-Daphnia Ecosystems Through Stage Structured Models And Colimitation, Tomas Ascoli

Biology and Medicine Through Mathematics Conference

No abstract provided.

Multiscale Modeling Of Microtubule Polarity Mechanisms Following Neuronal Axotomy, Hannah Scanlon

Biology and Medicine Through Mathematics Conference

No abstract provided.

Persistence Of Wastewater-Associated Antibiotic Resistant Bacteria In River Microcosms, Aoife P. Mahaney

Theses and Dissertations

The spread of antibiotic-resistant bacteria (ARB) associated with wastewater is a significant environmental concern, but little is known about the persistence and proliferation of these organisms in receiving water bodies after discharge. To address this knowledge gap, we performed a series of microcosm experiments in which river water was amended with either untreated or treated wastewater, and the abundance of viable ciprofloxacin-, Bactrim-, and erythromycin-resistant bacteria was monitored for 72 hours.

Both types of wastewater amendments increased the initial abundance of ARB compared to microcosms containing only river water. The increase was greatest with untreated wastewater, but that effect decreased …

How Does A Global Climate Cycle Affect The Reproductive Output Of A Neotropical Migratory Bird?, Abby K. Bressette, Emma Cummings, Daniel Albrecht-Mallinger, Lesley Bulluck

Undergraduate Research Posters

El-Niño Southern Oscillation (ENSO) causes regional changes in climate and has been found to have varying effects on the survival, fecundity, and recruitment of migratory songbirds. This study seeks to better understand the effect of ENSO on the fecundity of Virginia-breeding Prothonotary warbler (Protonotaria citrea; PROW), a neotropical migratory songbird. PROW breed in the Eastern United States and spend the non-breeding season primarily in Panama and Colombia. Ongoing research in Virginia has found a positive relationship between spring precipitation and predicted number of PROW fledgelings during La Niña, but the opposite during El Niño. To better understand this relationship, we …

Carry-Over Effects Of Climate On Prothonotary Warbler (Protonotaria Citrea) Feather Quality, Alyssa N. Spasic, Dan Albrecht-Mallinger, Lesley Bulluck

Undergraduate Research Posters

Avian species have inspired numerous studies on ornamentation, exploring its role in intra- and intersexual selection as a marker for individual quality. Male birds have been the focus of most of these studies while females, which can also display ornamentation, have been studied less. Coloration achieved through molt, particularly carotenoid-based pigments, requires energy derived from food resources. As climate affects insect abundance, there may be a link between climate conditions during molt and feather quality the following season. We assessed the relationship between temperature and precipitation during molt and female Prothonotary Warbler (Protonotaria citrea) breast and crown feather reflectance metrics …

Intermittent Synchronization In Gamma-Band Neural Oscillations, Anh Nguyen, Leonid L. Rubchinsky

Biology and Medicine Through Mathematics Conference

No abstract provided.

Dune Building Dynamics Impact Cross-Island Connectivity And Barrier Island Characteristics, Alexander Sabo

Theses and Dissertations

Located at the land-sea interface, barrier islands are important protective features that reduce wave energy and erosion from mainland areas. Further, barrier islands provide habitat for many different organisms and serve as popular areas for recreation and tourism. As sandy landforms, barrier islands are easily disturbed, but often recover after disturbance as a result of island plant communities, specifically dune building grasses. Disturbance on barrier islands is driven by storms, tides, and overwash events. After disturbance has occurred, dune grasses colonize the dunes allowing for dune building and habitat restoration. On the Virginia barrier islands, there are three dominant dune …

Pre-Clinical Trials With Precision-Medicine Based Therapeutics In Basal-Like Patient-Derived Xenografts, David C. Boyd

Theses and Dissertations

Breast cancer treatments have improved over time, but the diseases seeing the most benefit from these improvements have the estrogen receptor, progesterone receptor, or are positive for HER2. Basal-like breast cancer tends to not have these biomarkers, which necessitates their treatment to be traditional, untargeted therapeutics which are less effective and tend to have harsh adverse effect profiles – this is an important unmet need. These studies utilize a variety of techniques, including tissue culture, viability assays, high-throughput screening, in vivo drug treatments and imaging, pathway analyses, molecular techniques such as Western blot, antibody arrays, RNA sequencing, sc RNA sequencing, …

Plant Trait Effects On Tidal Wetland Methane Emission, Adam M. Dunn

Theses and Dissertations

High rates of carbon (C) sequestration exhibited by coastal wetlands is an important natural climate solution to global environmental change. At the same time, however, wetlands are the largest natural source of methane (CH₄) to Earth’s atmosphere, a potent greenhouse gas that influences the global climate. Wetland CH₄ emissions display high degrees of uncertainty in accounting for spatial and temporal variations in emissions due to the complex interactions between biotic and abiotic factors that influence methane production and transport, in addition to simultaneous influences from climate-driven effects on wetlands such as rapid sea level rise and increased …

Epithelial Membrane Protein 3 (Emp3b) Is A Novel Regulator Of Sympathetic Nervous System Development In Zebrafish., Jessica M. White

Theses and Dissertations

Notable progress has been made in understanding the development of the neural crest (NC). Neural crest cells (NCCs) can be divided into 4-5 subpopulations. A major lineage among trunk NC derivatives are sympathoadrenal (SA) cells, which give rise to the sympathetic nervous system (SNS). Trunk NCCs follow a ventromedial migration pathway where signals derived from the dorsal aorta instruct migrating NCCs to a SA cell fate. Defects in NC development can result in syndromes known as neurocristopathies. Neuroblastoma is one of the most common forms of pediatric cancer affecting nearly 800 infants each year in the United States (Takita et …

Salinization Impacts On Heterotrophic Respiration, Ecosystem Respiration, And Plant Productivity In Tidal Freshwater Marshes, Kelsie J. Moses

Theses and Dissertations

Tidal freshwater marshes have preserved substantial stocks of soil carbon, which represents carbon dioxide that is no longer in the atmosphere. There is conflicting evidence in the literature about how disturbances such as sea level rise and associated wetland salinization impact the accumulation and long-term stability of this stored carbon. The goal of this experiment was to quantify how salinization impacts total ecosystem respiration and its component parts, autotrophic and heterotrophic respiration. This was a microcosm experiment using a C4 plant (Spartina cynosuroides) grown in soil derived from C3 plant matter and exposed to different salinities (0 to …

Proposing An Rna Interference (Rnai)-Based Treatment For Human Immunodeficiency Virus (Hiv) By Analyzing The Post-Transcriptional Gene Targeting Of Sars-Cov-2, Hepatitis C Virus, And A549 Lung Cancer Cells, Arjun Jagdeesh

Undergraduate Research Posters

Human Immunodeficiency Virus (HIV) is a retrovirus that infects CD4+ T cell lymphocytes in humans, leading to the development of Acquired Immunodeficiency Syndrome (AIDS) if left untreated. While current treatment methods, including antiretroviral combination treatments, effectively limit HIV replication, HIV can evade these treatments due to its high mutation rate. Long-term antiretroviral treatment can also be toxic to patients, meaning patients would benefit from a new mechanism of HIV treatment. RNA interference (RNAi) is an antiviral pathway found in mammals, plants, and insects that involves a small-interfering RNA that is incorporated into a protein complex called the RNA-induced Silencing Complex …

Genetically Explicit Model May Explain Multigenerational Control Of Emergent Turing Patterns In Hybrid Mimulus, Emily Simmons

Biology and Medicine Through Mathematics Conference

No abstract provided.

Fish Sound Production: The Swim Bladder, Michael L. Fine, Eric Parmentier

Biology Publications

Analogous to the syrinx in birds and larynx in mammals, the swim bladder is a major sound-producing organ in fishes. It also functions in hearing and is responsible for most returns from sonar. Historically, the swim bladder has been modeled as an underwater resonant bubble, whereas we provide evidence for a forced-response model in which viscous damping of the bladder wall inhibits resonance of the internal bubble. Further experimental work on the shape, wall structure, and mechanical behavior of the swim bladder is required.

An Investigation Of Bubble Resonance And Its Implications For Sound Production By Deepwater Fishes, Mark W. Sprague, Michael L. Fine, Timothy M. Cameron

Biology Publications

Although the continental slope and abyss comprise the largest habitat on earth, the absence of documented fish sounds from deep waters is striking. Fishes with sexually dimorphic muscles attached to their swim bladders suggests that sounds are likely used in male courtship on the upper, mid and lower continental slope. To investigate the effects of environmental extremes on fish sound production, the acoustic behavior of a driven bubble is examined. This study is also relevant to target strength of sonar returns from fish and hearing in auditory specialist fishes. A bubble is a classic, if imperfect, model for swim bladder …

Chronic Adolescent Stress As A Predictive Factor For The Risk Of Developing Ptsd-Like Symptoms In Adulthood, Grace K. Young

Theses and Dissertations

Post-traumatic stress disorder is a stress and trauma based psychological disorder that is defined by the DSM-IV as an anxiety disorder that affects approximately 7.8% of people in the United States. PTSD is when those who suffer a traumatic event have intense and distressing feelings, emotions, and memories for a prolonged period of time after the event. A prominent feature of PTSD is the impaired ability to properly extinguish a fear response after a dangerous trigger or stressor is no longer present, also known as safety learning. Stressors are threats perceived within the environment that activate a response within the …

Biotic Characteristics Of Managed And Unmanaged Coastal Dunes In The Outer Banks, North Carolina, Andrew E. White

Theses and Dissertations

Under future climate change and sea level rise scenarios, Natural and Nature-Based Features (e.g., dunes) that protect coastal habitat and infrastructure will be exposed to increased wave energy and storm surge. Understanding how these forces will impact coastal dunes is necessary for their continued use as protective features. Coastal dunes develop through feedback between vegetation and sediment deposition, a process complicated by species-specific growth rates and responses to burial. Wave flume studies have tested the effects of dune vegetation on erosion and found multiple plant organs across several functional types to be important for resisting erosion. Although dune building and …

Developmental Validation Of A Bacterial Signature-Based Identification Method Of Forensically Relevant Human Biological Samples, Denise M. Wohlfahrt

Theses and Dissertations

The confirmatory identification of body fluids is one of the most critical steps in criminal investigations, as it provides not only information on the source of the DNA, but it can corroborate evidence, aid in the reconstruction of a crime, and associate evidence with a person of interest. Current serological methods utilize biochemistry and immunology to identify biological evidence; however, these serological tests are mostly presumptive while only testing for one fluid at a time, potentially wasting precious evidence. More recently, forensic investigators have suggested the use of molecular methods such as mRNA, miRNA, or DNA methylation. While each of …

Coupled Structure-Function Responses To Disturbance: High Structural Complexity Resistance Supports Primary Production Resistance, Kerstin M. Niedermaier

Theses and Dissertations

The capacity of forests to resist structural change and retain material legacies–the biotic and abiotic resources that persist through disturbance–is crucial to sustaining ecosystem functioning after disturbance. However, the role of forest structure as both a material legacy and feature supporting carbon (C) cycling stability following disturbance has not been widely investigated. We used a large-scale disturbance manipulation to ask whether LiDAR-derived canopy structures as material legacies drive 3-year responses of NPP to a range of disturbance severity levels. As part of the Forest Resilience Threshold Experiment (FoRTE) in northern Michigan, USA we simulated phloem-disrupting disturbances at a range of …

Advancing Forest Structure-Function Relationships: Linking Above- And Belowground Structure To Soil Respiration, Laura J. Hickey

Theses and Dissertations

Variation in the soil-to-atmosphere C flux, or soil respiration (Rs), is influenced by a suite of biotic and abiotic factors, including soil temperature, soil moisture, and root biomass. However, whether canopy structure is tied to soil respiration through its simultaneous influence over these drivers is not known. We assessed relationships between measures of above- and belowground vegetation density and complexity, and evaluated whether Rs is linked to remotely sensed canopy structure through pathways mediated by established biotic and abiotic mechanisms. Our results revealed that, at stand-scale, canopy rugosity–a measure of complexity–and vegetation area index were coupled to soil respiration through …

Introduction Of Plasmid Dna Into Sneathia Vaginalis; The First Step To Genetic Manipulation, Rea Mansukhani, Cathyrn O'Brien, Zion Mccoy, Kimberly K. Jefferson

Undergraduate Research Posters

Many bacterial pathogens are capable of secreting one or more toxins, all of which can be categorized based on their function, target, or mechanism of action. Pore-forming toxins, for instance, are characterized based on their ability to perforate the host membrane. This may result in the delivery of bacterial substances into the host cell, release of compounds from the host cell, and/or death of the host cell. Research from our lab has demonstrated that Sneathia vaginalis, a gram-negative anaerobic bacterial species that is associated with bacterial vaginosis and preterm birth, produces a pore-forming toxin referred to as cytopathogenic toxin …

Qualitative And Quantitative Characterization Of Epithelial Cell Mixtures Using Hormone Antibody Probes And Flow Cytometry, Luke Baldridge

Theses and Dissertations

“Touch” DNA is evidence that consists of epidermal cells deposited by handling objects and it is becoming more common in evidence samples processed in crime labs. Because “touch” DNA evidence samples may be low-template DNA and are often mixtures, there is a need to both nondestructively estimate the amount of DNA present prior to DNA purification and to identify and characterize mixtures prior to DNA typing. The purpose of this study was to test the use of FITC-labeled anti-testosterone antibodies as a potential tool to estimate the number of contributors in two-, three-, and four-person mixtures of epidermal skin cells, …

Quantitative Pcr And Sanger Sequencing Of Mitochondrial Dna Recovered From Waterlogged Bone, Kailey Babcock

Theses and Dissertations

In forensic contexts, samples containing heavily fragmented DNA are commonly encountered. Compromised biological samples are especially prevalent in instances where human remains have been submerged in an aqueous environment for extended periods of time. Nuclear DNA is particularly vulnerable to the prolonged exposure to heat, moisture, and bacterial degradation that are prevalent in aquatic settings. Paired with the difficulty of recovering DNA from skeletal remains, which are often the only remaining component after the soft tissues have been stripped away, mitochondrial DNA (mtDNA) analysis serves as an invaluable alternative. In this multifaceted study, mtDNA analysis was performed on waterlogged bone …

Qualitative And Quantitative Characterization Of Epithelial Cell Mixtures Using Hormone Antibody Probes And Flow Cytometry, Luke Baldridge

Master of Science in Forensic Science Directed Research Projects

“Touch” DNA is evidence that consists of epidermal cells deposited by handling objects and it is becoming more common in evidence samples processed in crime labs. Because “touch” DNA evidence samples may be low-template DNA and are often mixtures, there is a need to both nondestructively estimate the amount of DNA present prior to DNA purification and to identify and characterize mixtures prior to DNA typing. The purpose of this study was to test the use of FITC-labeled anti-testosterone antibodies as a potential tool to estimate the number of contributors in two-, three-, and four-person mixtures of epidermal skin cells, …

The Mechanisms And Consequences Of Shrub Encroachment On The Virginia Barrier Islands, Lauren K. Wood

Theses and Dissertations

Shrub encroachment is a global phenomenon driven by direct and indirect anthropogenic influence which alters plant communities and ecosystem function. Many studies have investigated drivers and consequences of woody plant establishment, but mesic landscapes are underrepresented in the literature. My objective was to assess the mechanisms of Morella cerifera encroachment into coastal mesic grassland, the potential for self-reinforcement, and consequences on community composition, nutrients, and landscape productivity. I studied temperature and water microclimate modification by Morella cerifera presence and removal to understand ecosystem engineering and community composition changes. Additionally, I examined the influence of shrubs on surrounding grassland species traits …

Quantitative Pcr And Sanger Sequencing Of Mitochondrial Dna Recovered From Waterlogged Bone, Kailey Babcock

Master of Science in Forensic Science Directed Research Projects

In forensic contexts, samples containing heavily fragmented DNA are commonly encountered. Compromised biological samples are especially prevalent in instances where human remains have been submerged in an aqueous environment for extended periods of time. Nuclear DNA is particularly vulnerable to the prolonged exposure to heat, moisture, and bacterial degradation that are prevalent in aquatic settings. Paired with the difficulty of recovering DNA from skeletal remains, which are often the only remaining component after the soft tissues have been stripped away, mitochondrial DNA (mtDNA) analysis serves as an invaluable alternative. In this multifaceted study, mtDNA analysis was performed on waterlogged bone …

Water Clarity At The River-Estuary Transition Zone: A Comparative Study Of The James, Mattaponi, And Pamunkey Sub-Estuaries, Rachel Henderson

Theses and Dissertations

Water clarity is a key parameter for monitoring water quality and often used to assess habitat suitability for submerged aquatic vegetation (SAV). Light attenuation, a measure of water clarity, is impacted by colored dissolved organic matter (CDOM), and by suspended particulates which include living and non-living components. We anticipated that the relative importance of these factors in regulating light attenuation would vary among the upper portions of three sub-estuaries differing in morphometry, hydrology, and degree of human influence. The James is characterized by eutrophic conditions and high algal abundance, whereas the Mattaponi and Pamunkey exhibit lower phytoplankton production. The Mattaponi …

Impact Of Targeting Glycosylated Ceramides On Tumorigenic Properties, And Characterization Of Sphingolipids In Head And Neck Tumors, Katherine E. Hylton

Theses and Dissertations

Sphingolipids play a crucial role in signaling, membrane structure, and migration, making them important molecules in cancer development, metastasis, and drug resistance. While some sphingolipids have been associated with pro-apoptotic or pro-survival behaviors, the role of many sphingolipids in cancer remains poorly defined. Chapter 1 of this study investigated the impact of three enzymes that compose most of the ceramide to Lc3 ceramide pathway – UGCG, GBA, and B3GNT5 – and how their alteration impacts chemoresistance and basal membrane invasion in vitro. It was found that the CΒE-induced inhibition of GBA, which converts glucosylceramide to ceramide, has no effects on …

Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin

Theses and Dissertations

Understanding habitat selection at multiple scales is an important step in guiding conservation programs and reversing species declines. This, however, is difficult for species that occupy early-successional habitats (ESH) due to a lack of accurate representation of shrub cover in publicly available land cover data. The Golden-winged Warbler (Vermivora chrysoptera; GWWA) is a threatened species of conservation concern and a flagship for ESH conservation. We used a novel, LIDAR-derived land cover classification that accurately identifies shrubs at a fine resolution (1m) to investigate how habitat composition and configuration influence GWWA site occupancy. We aggregated this same land cover …