Life Sciences Commons^™

Effect Of Sex On The Accumulation Of Hepatic Mercury In Mallards Wintering In Louisiana, Latorya E. Mason

Master's Theses

The increase in mercury production through anthropogenic activities has led to a global crisis of mercury pollution that poses a significant threat to the health of both humans and wildlife. Aquatic ecosystems are especially at risk due to the creation of methylmercury, a toxic form of mercury, by sulfate-reducing bacteria in anoxic sediments and soils. Methylmercury enters the food chain where it bioaccumulates in individual organisms and then biomagnified with increasing trophic level. Aquatic birds are useful bioindicators of many pollutants, including mercury, due to their abundance and position in the food chain. Previous studies have primarily focused on mercury …

Impact Of Temperature On Children’S Nutrition: A Comparative Study Of Three Ecological Regions Of Nepal, Prakriti Shakya

Master's Theses

Nutrition obtained during the growth period of childhood significantly influences long-term well-being and overall productivity, ultimately contributing to the economy of a society. However, weather shocks can wreak havoc by damaging crops, changing yields of important crops and disrupting market access, which directly impacts the food intake of both adults and children. When these adverse events occur during childhood, short term and long term inadequacy in nutrition as well as disease incidence can cause malnutrition leading to stunted growth and cognitive impairment that may persist into adulthood, affecting the labor market and increasing health expenditure. To address this issue, we …

Downregulation Of Dax-1 Expression Via Mirna Overexpression As A Mechanism To Potentiate Breast Cancer, Nicholas C. Devito

Master's Theses

The orphan nuclear receptor DAX-1 (Dosage Sensitive Sex Reversal, Adrenal Hypoplasia Congenita, critical region on the X chromosome, gene 1) plays a key role in mammalian sex determination and steroidogenesis. In addition to these canonical examples, DAX-1 has been shown to play a contradictory role in cancer development. While DAX-1 is overexpressed in lung and prostate cancer, it is downregulated in breast cancer. One of the explanations for the paradoxical role of DAX-1 in cancer development could be microRNA (miRNA) dysregulation. After broadly surveying over 96 miRNAs historically upregulated in MCF7 breast cancer cells, we compared the expression of DAX-1 …

The Impact Of Index Based Livestock Insurance (Ibli) On Child Nutrition In Marsabit County, Kenya, Jackson Kadyampakeni

Master's Theses

The study uses six rounds of Index-Based Livestock Insurance (IBLI) panel surveys (2009 – 2015) for Northern Kenya’s Marsabit county to investigate the impact of IBLI on child nutrition and household food security. We employ Ordinary Least Squares (OLS) and Instrumental Variable (IV) regressions to account for potential endogeneity in IBLI uptake. The results indicate that while IBLI uptake significantly improves the intake of key nutrients such as Vitamin A, protein, iron, and fruits and vegetables, it does not translate into significant improvements in child nutrition status, as measured by Mid-Upper Arm Circumference (MUAC) z-scores. Significant negative effects of age …

Impact Of Toll-Like Receptor 10 Mutations On Tuberculosis Infections, Adriana Nicole Rafael, Sangman Kim

Master's Theses

Tuberculosis (TB), caused by the intracellular pathogen Mycobacterium tuberculosis (M. tb), is a leading global health crisis causing millions of cases and deaths each year. Though it affects individuals of any race, ethnicity, or cultural group, research shows the disease disproportionately affects individuals with Asian ancestry. Immunity to M. tb starts with its recognition by pattern recognition receptors such as Toll-like receptors (TLRs), which are key players in immune responses. TLR-10, an understudied toll-like receptor due to its inability to be studied through mouse models, is thought to play a key role in the clearance of inflammatory diseases. SNP I775V, …

Soil Bacterial Community Shifts In A Montane Longleaf Pine Restoration Site: Effects Of Dominant Herbaceous Species Removal, Prescribed Burn, And Changes In Season, Isabella K. Vahle

Master's Theses

Longleaf pine (Pinus palustris Mill.) ecosystems are one of the most endangered and ecologically diverse systems in North America. The native herbaceous species serve as fuel for low-intensity, recurring fires this system relies on. The herbaceous species play major roles in maintaining ecosystem structure and diversity. Soil microorganisms like bacteria are known to aid greatly in many different plant and ecosystem processes. However, little is known about the dominant herbaceous species and soil bacterial compositions within montane longleaf pine ecosystems, especially before and after a prescribed fire. We completed a multiyear, seasonal analysis of the soil bacterial community in …

Patterns And Potential Mechanisms Of Phenotypic Changes In Urban Small Mammals, Leslie Lopez

Master's Theses

Urbanization is an example of human induced rapid environmental change that can have wide-reaching ecological effects, including habitat destruction, fragmentation, and alteration of local climates. Effects of urbanization have been shown to impact wildlife, as disturbances resulting from urbanization can create novel environments and selective pressures that could lead to changes in morphology, physiology, or both. Small mammals such as rodents are an ecologically important set of wildlife species because they are a key prey item for several predators, hold strong influence over plants as a primary consumer, and some species carry and transmit major human and animal diseases. Previous …

Regulation Of Intracellular Sorting Of The Bruno Protein In Drosophila Flight Muscles, Travis Main

Master's Theses

Understanding mechanisms of intracellular sorting is a fundamental inquiry of cell biology. We used the B-body and protein Bruno (Bru) as a model to study the formation of nuclear domains that are membraneless organelles inside the cell nucleus. Specifically, we sought to identify protein sequences that regulate Bru's affinity to B-bodies and protein aggregation. We generated various Bru mutants and subsequently tested them in vivo using fluorescence microscopy. We found that the protein solubility of Bru is determined through an interplay of RNA recognition motifs (RRMs) and intrinsically disordered regions (IDRs). Using truncation analysis, we identified a 31-amino acid region …

The Role Of B Cell Activation State And Sex In Aryl Hydrocarbon Receptor Mediated Induction Of Chemokine Receptor 9 And Alpha4beta7 Expression In Vitro, Logan Bauerle

Master's Theses

Defense of mucosal tissues from microbial infection and allergy is reliant on continual production of antibodies. The aryl hydrocarbon receptor (AhR) is known to regulate B cell development and is associated with suppression of systemic humoral immunity. Recent attention has been paid to the role of the AhR in altering expression of cell adhesion molecules (CAMs). B cells express CAMs and chemokine receptors to migrate around the body for localized secretion of antibodies. AhR agonists promote B cell migration to the small intestine through upregulation of chemokine receptor 9 (CCR9) and integrin α₄β₇. Both the AhR …

Role Of Atp-Binding Cassette (Abc) Transporters As A Protector Of Testis Stem Cell Niche From Chemotherapy Drugs In Drosophila Melanogaster, Swagata Maity

Master's Theses

In chemotherapy treatments most tumor cells are destroyed by drugs, but some tumor cells are drug resistant, and these are known as cancer stem cells (CSCs). Normal adult stem cells are also chemo resistant. Therefore, investigation of normal stem cells can be useful to provide further knowledge of CSCs. One of the primary ways that CSCs achieve drug resistance is by drug efflux through transmembrane pumps called ATP-binding cassette (ABC) transporters. Many studies on ABC transporters have been performed in vitro using cultured cell lines, but very few studies have been performed on normal stem cell populations in vivo. Drosophila …

Clonal Plants' Traits And Responses Following Fire Disturbance In Ponderosa Pine Ecosystems In The Colorado Front Range, Raymond Erskine

Master's Theses

Mountain ecosystems are currently experiencing increasing impacts of disturbances (e.g., wildfire) due to global changes in climate and land use, leading to significant changes in vegetation composition and landscape dynamics. Clonal plants, characterized by their vegetative reproduction strategies, offer a range of ecologically important traits to cope with disturbances. However, clonality is often excluded in studies of post-fire vegetation dynamics in mountain ecosystems, and our knowledge of the ability of clonal plants to respond to differing disturbance regimes is limited. Therefore, I examined the response of understory vegetation following fire disturbance in burned and unburned ponderosa pine stands of the …

Clonal Growth And Trait Variation In The Colorado Front Range: The Influence Of Elevation And Ecosystem, Jordan Conley

Master's Theses

Amid global climate change, exploring adaptive strategies among alpine flora, particularly through clonal growth, becomes critical for biodiversity conservation. This study aims to explore the patterns of dominance and distributions among clonal species across environmental gradients in the Colorado Front Range, employing a trait-based comparative analysis to understand the adaptive strategies of alpine flora and their implications for conservation amid rapid climate change. We focused on two species, studying traits like lateral spread, bud count, and bulbil numbers. Advanced statistical methods such as Permutational Multivariate Analysis of Variance (PerMANOVA) and Multi-Response Permutation Procedures (MRPP) were used to evaluate community compositions …

Molecular Characterization Of Stress Response In Western Honey Bee (Apis Mellifera), Faizan Tahir

Master's Theses

Honey bees are incredibly important for the reproduction of flowering plants and the sustainability of agricultural ecosystems. However, they face various stressors such as pesticides, pathogens, habitat loss, and climate change. Extensive research has been conducted to understand how bees respond to these stressors. Scientists have discovered that honey bees exhibit complex physiological and behavioral responses to stress at individual and colony levels. Stress can have a significant impact on their immune function, foraging behavior, and reproductive success (Decourtye et al., 2010). Understanding bee responses to stress is crucial for several reasons. Firstly, honey bees are vital for the pollination …

Salinity Tolerance Of Flowering Rush, Butomus Umbellatus, Andrew Coomes

Master's Theses

Flowering rush is an invasive aquatic plant in North America that causes deleterious effects to native ecosystems. There are two cytotypes, a triploid and diploid, and multiple genotypes contained within the diploid cytotype currently established in the U.S. Despite its presence in river drainages connected to estuarine areas, documentation on the salinity tolerance of flowering rush is scarce. Currently, information is limited to anecdotal reports suggesting intolerance to saline conditions. A better understanding of the osmotic tolerance of this species is essential to providing insight into its’ invasive range and better inform management efforts. These studies investigated vegetative propagule germination …

The Assessment Of Autonomic Function In Young Adults With An Elevated Risk Of Metabolic Syndrome, Ta'quoris Newsome

Master's Theses

Metabolic syndrome (MetS) is a complex medical condition defined by the co-occurrence of multiple cardiometabolic risk factors. Despite the well-defined profile of autonomic function in individuals with MetS, autonomic function in those with an elevated risk of developing MetS remains unclear. Our study aimed to shed light on the progression of cardiometabolic disease and its impact on autonomic function. To investigate, twenty participants, ten of whom were classified as having an elevated risk of developing MetS based on identification of risk factors using NCEP ATP III criteria, completed a two-visit study protocol. In the second visit, spontaneous cardiovagal baroreflex sensitivity …

Examining The Effects Of Food Supply On Eastern Oyster (Crassostrea Virginica) Larval Performance And Settlement Potential In Delaware Bay And Mississippi Sound, James C. Klein

Master's Theses

Oyster population maintenance and growth require sufficient larval stocks capable of timely development, growth, and successful metamorphosis, whereby larval performance and settlement potential determines the capacity for a larval cohort to effectively establish into an existing population. Exogenous factors influencing larval performance include temperature, salinity, and particularly food supply. Regarding food, a sufficiently abundant and nutritionally balanced diet composed of protein, lipids, and carbohydrates is critical for successful metamorphosis. The influence of exogenous factors on Crassostrea virginica settlement potential were examined in Delaware Bay and Mississippi Sound by incorporating in situ environmental conditions and food supply metrics into a well-established …

Analysis Of Social Behavior Of The African Great Apes During Feeding And Non-Feeding Contexts, Jessica Hale

Master's Theses

The three African great apes, bonobos, chimpanzees and gorillas, despite similar habitats, differ considerably in their sociality and feeding ecology. There have been many studies that have investigated the feeding ecology and social behaviors of these species, but there is extremely limited literature available on how feeding ecology may have affected ape social evolution. Chimpanzees are frugivorous, which forces them into close proximity when foraging given the clumped nature of this resource. Bonobos and gorillas, however, are fallback food consumers, which allow them to spread out as they forage. This thesis project aims to test the hypothesis that differences in …

The Immune Contribution To Postpartum Remodeling, Jessica Caroline Ming

Master's Theses

Following parturition, the uterus must undergo significant changes in size and structure through a process called postpartum remodeling. This process is known to have both pro- and anti- inflammatory components. However, how various immune cells contribute to remodeling and the pathways that promote inflammation are not well understood. We hypothesize that immune cells that infiltrate the uterus postpartum modulate inflammation to promote postpartum remodeling. Our preliminary data suggests that inflammatory cell death may contribute to the inflammation present in the early postpartum period, and thus further studies will analyze caspase-1, gasdermin D, and IL-1β and IL-18. To analyze the immune …

Role Of Toll-Like Receptor 2 In Macrophage Recognition And Response To Borrelia Burgdorferi, Yukiye A. Koide

Master's Theses

Lyme disease is the most common vector-borne disease in the US and will experience an uptick as the insect host, the ixodid tick, gains habitat with climate change. The causative agent of Lyme disease, Borrelia burgdorferi, is recognized by Toll-like receptor 2 (TLR2), which initiates the innate immune response. Here, I used ELISA and SEAP detection assays to determine that knocking out TLR2 in THP-1 macrophages reduces the amount of NFkB activation, as well as IL-10 and IL-1β secretion. Then, I used fluorescence microscopy and Incucyte assays to quantify the amount of phagocytosis performed by wild-type and knock-out THP-1 cells. …

Species Delimitation Of Slimy Salamanders, Plethodon Kisatchie And Plethodon Mississippi, Across The Lower Mississippi River, Brock Hunter Stevenson

Master's Theses

Species are fundamental units of biodiversity yet delimiting species can be challenging. Slimy Salamanders of the Plethodon glutinosus species complex are a classic example of cryptic species for which species boundaries and relationships have proved difficult to determine. Once thought to be a single species ranging across the eastern United States, protein analysis revealed high genetic divergences among geographically distinct groups of populations, leading to 16 species being recognized within the group. Two of these species, the Louisiana Slimy Salamander (Plethodon kisatchie) and the Mississippi Slimy Salamander (Plethodon mississippi), are closely related but occur on opposite sides of the Mississippi …

Automated Tree Mortality Detection Using Ubiquitously Available Public Data, Michael T. Huggins

Master's Theses

Understanding the dynamic interplay between fire severity, topography, and tree mortality, is crucial for predicting future forest dynamics and enhancing resilience against climate change-induced wildfire regimes. This thesis develops a multi-sensor approach for automated estimation of tree mortality, then applies it to examine trends in tree mortality over a six-year period across a fire affected study site in the Trinity River basin in Northern California. The Random Forest model uses publicly available USGS 3D Elevation Program Lidar (3DEP) and NAIP imagery as inputs and is likely to be easily adaptable to other landscapes. The model had a Receiver Operating Characteristic …

Effects Of Anthropogenic Noise On The Provisioning Behavior Of Western Bluebirds And Artificial Light At Night On Nestling Development, Kerstin H. Ozkan

Master's Theses

Sensory environments are rapidly changing due to increased human activity in urban and non-urban areas alike. For instance, background sounds can interfere with parent-offspring communication and mask cues reflective of predation risk, resulting in elevated vigilance at the cost of provisioning. In chapter 1, we studied nestling provisioning behavior among Western Bluebirds (Sialia mexicana) in response to short-term (1 hr) and long-term (continuous exposure throughout nesting period) noise exposure. Provisioning rates were lower at nests exposed to short-term experimental traffic noise compared to exposure to ambient background sounds. Trial order strongly influenced provisioning behavior, with the decline in …

Coralai: Emergent Ecosystems Of Neural Cellular Automata, Aidan A. Barbieux, Aidan A. Barbieux

Master's Theses

Artificial intelligence has traditionally been approached through centralized architectures and optimization of specific metrics on large datasets. However, the frontiers of fields spanning cognitive science, biology, physics, and computer science suggest that intelligence is better understood as a multi-scale, decentralized, emergent phenomenon. As such, scaling up approaches that mirror the natural world may be one of the next big advances in AI. This thesis presents Coralai, a framework for efficiently simulating the emergence of diverse artificial life ecosystems integrated with modular physics. The key innovations of Coralai include: 1) Hosting diverse Neural Cellular Automata organisms in the same simulation that …

Descriptive Study Of Adult Male Acheta Domesticus Phonotaxis, Dana Husana

Master's Theses

The phonotactic behavior of male Acheta domesticus has not been described at length. The present study evaluates the phonotactic responses of male A. domesticus in relation to age. Male crickets of different ages (young and old) were exposed to calls with attractive and non-attractive syllable periods for this species. Both age groups exhibited phonotaxis but did not show a preference towards the attractive call over the non-attractive ones. No significant relationship was found between age and phonotactic response. Additionally, no significant differences were observed between age and preferred syllable period. Acoustic responses were also observed in some of the older …

Covalent Inhibition Of Enzyme Sortase A As A New Pathway Against Bacterial Resistance Of Staphylococcus Aureus, Umyeena Bashir

Master's Theses

The continued rise of antibiotic-resistant bacteria, such as MRSA (methicillin-resistant Staphylococcus aureus), has made the discovery of novel antibiotics critical. While bacteriostatic and bactericidal antibiotics inevitably exert evolutionary pressure on bacteria to develop resistance, small molecules that target mechanisms of bacterial virulence present a promising alternative for treatment. Sortase A (Srt A), a cysteine protease of S. aureus, promotes bacterial virulence by covalently attaching proteins such as pilin to the bacterial surface, enabling bacterial adhesion to mammalian cells. Inhibitory studies of this enzyme have gained prominent interest as a new pathway for drug development since blocking this enzyme's ability to …

Polluting The Senses: The Impact Of Noise And Light Pollution On Fledgling Movement And Evolution Within The Avian Eye, Margaret C. Mackinlay

Master's Theses

There is more human-generated noise and light today than ever before, a trend tied to ongoing urbanization and with reverberating impacts on a wide range of organisms. While research on these impacts is mounting and particularly plentiful when it comes to birds, there is still much to explore within its effects on avian behavior, fitness, and evolution. In chapter 1, we investigated how fledgling movement is influenced by noise and light pollution. While adult birds have well-documented species-specific responses to these stimuli, fledglings are sorely understudied in this context. We experimentally manipulated light levels and took advantage of an existing …

Deep Ocean Vehicle Applications And Modifications, Nichole "Nikki" T. Arm

Master's Theses

This project had two primary goals: (1) to explore opportunities to further a deep-ocean vehicle’s reach using alternative pressure spheres, and (2) to implement an existing deep-ocean vehicle (lander) in active scientific research.

I gained a greater understanding of the limitations and design choices made for existing pressure spheres using Finite Element Analysis (FEA). My simplified FEA model predicted sphere failure for the existing 30% Fiber Glass 70% Nylon injection molded spheres at an external pressure of 3,954psi or 2,690m ocean-depth (only a 7.38% error compared to the tested minimum failure depth), so I determined it a valid model. I …

Evaluation Of Facilitation On Translocation Outcomes For San Joaquin Antelope Squirrel In The Carrizo Plain, California, Patrick R. Anderson

Master's Theses

In arid and semi-arid environments, burrowing mammals play a key role in increasing landscape heterogeneity through facilitative species interactions. The loss of burrowing mammal populations can consequently lead to negative effects cascading through the ecosystem. It is critical to understand these facilitative interactions for conservation and management. Understanding facilitative interactions may improve wildlife management tools, like translocation, which is often not very successful. To investigate the importance of burrow facilitation on San Joaquin antelope squirrel (Ammospermophilus nelsoni; SJAS) translocation success, I designed a natural experiment with a burrowing facilitator, the giant kangaroo rat (Dipodomys ingens; GKR). I …

How Sewage Pollution Affects Distribution And Life History Traits Of The Southern House Mosquito, Culex Quinquefasciatus, Catherine Dean Bermond

Master's Theses

Eutrophication from wastewater can cause fluxes of nutrients like and carbon and nitrogen in urban waters. One source of nitrogen in freshwater is from untreated sewage discharging from septic tanks. This causes a variety of environmental issues including harmful algal blooms, harming natural predators, and increased production of mosquitoes. Culex quinquefasciatus is the vector of West Nile Virus in St. Tammany Parish, Louisiana. St. Tammany Parish has over 600 miles of septic ditches, which receive effluent directly from aerated treatment units. Culex quinquefasciatus oviposit in polluted waters, and larvae perform well in water with high levels of decomposing organic matter. …

Evaluating Habitat Use By Nekton In Widgeon Grass (Ruppia Maritima), Shoal Grass (Halodule Wrightii), And Unvegetated Bottom Habitats In The Grand Bay National Estuarine Research Reserve, Jessica Woodall

Master's Theses

Seagrass beds support high biodiversity and animal abundance, serve as feeding grounds for a variety of animals, offer shelter from predation, and act as a nursery habitat for juveniles. The species composition of seagrass beds can impact their use as habitat by animals. Two common species of seagrass in the Gulf of Mexico are Ruppia maritima (widgeon grass) and Halodule wrightii (shoal grass). The shallow coastal waters of the Grand Bay National Estuarine Research Reserve (NERR) support both species, but the use of each seagrass as habitat by nekton is poorly understood, which can limit management decision-making. Nekton communities were …