Life Sciences Commons^™

The Role Of Semaphorins In Response To Injury In C. Elegans Neurons, Maria Belen Harreguy Alfonso

Dissertations

When neural tissue is injured by trauma, delicate neuronal processes such as axons and dendrites are prone to lesion damage and often disconnect. The molecular, cellular, and circuit mechanisms that underlie the regrowth and reconnection of these processes and the recovery of behavior are major challenges in the fields of neuroscience, regeneration, and resilience. At the molecular and cellular levels, signaling pathways that mediate neuronal growth cone guidance during development can play a role in neuronal regeneration and recovery from injury. One family of signaling proteins involved in this process comprises the highly conserved semaphorins and their receptors, the plexins. …

Isolation And Characterization Of Bacteriophages From Fish Tank Samples, Oluwaseyi Oluwagbeminiyi Oladele-Ajose

Electronic Theses and Dissertations

Bacteriophages (phages) are viral obligate intracellular parasites that infect bacteria. Research has been carried out on alternative treatment plans for bacterial infections due to the increase in antibiotic resistance. Phages have been proposed as an alternative to antibiotics. This research focused on the isolation and characterization of bacteria from small aquariums. A total of 42 bacterial isolates were isolated from seven different fish tank water samples and were tested to determine if they possessed phages. Spot plaque assay revealed presence of lytic phage for only one of the isolated bacterial strains, which was determined to belong to Enterobacteriaceae family based …

Characterizing The Ecology Of Plains (Spilogale Interrupta) And Eastern (Spilogale Putorius) Spotted Skunks: A Systematic Literature Review And Population Assessment In Kansas, Jenell De La Peña

Electronic Theses & Dissertations

The plains spotted skunk (Spilogale interrupta) has recently been recognized as a distinct species from the eastern spotted skunk (Spilogale putorius). While once abundant across the central and eastern United States, both species have experienced population declines, resulting in their review for listing under the Endangered Species Act (1973). In Kansas, the plains spotted skunk has suffered a particularly dramatic decline, the last detection in the state having occurred in 2020. Additionally, due to the recent taxonomic split, many past studies reporting on S. putorius ecology actually describe findings of two species, potentially complicating our understanding …

Habitat And Demography Of The Ozark Chinquapin (Castanea Ozarkensis) At Roaring River State Park In Barry County, Missouri, Danielle Evilsizor

Electronic Theses & Dissertations

The Ozark chinquapin, Castanea ozarkensis Ashe, is a chestnut tree with a range concentrated in the Interior Highlands of North America. Like other North American members of Castanea, it was reduced from an overstory tree to an understory shrub by the invasive chestnut blight fungus (Cryphonectria parasitica [Murrill] M.E. Barr) during the early 20^th century. However, relatively little is known about the habitat of this species or its health and reproductive capability post chestnut blight. Chapter one of this study analyzed the habitat of this species through a random forest species distribution model (SDM) to predict where …

Investigating The Soil Mycobiome Of American Ginseng, Rachel Amelia Rajsp

Electronic Thesis and Dissertation Repository

American ginseng (Panax quinquefolius L.) is a perennial herbaceous plant cultivated for its medicinal properties. Growers report that when ginseng is replanted in a field previously used to cultivate ginseng, it soon succumbs to disease, known as ginseng replant disease. I examined changes in composition in the ginseng mycobiome throughout cultivation in a newly planted garden and beyond (i.e., 3–14 years post-harvest) with a third-generation metabarcoding approach (Pacific Biosciences, single-molecule real-time sequencing). Amplicons of about 600 nucleotides from the nuclear ribosomal internal transcribed spacer (ITS) region and translation elongation factor 1-α gene were chosen to help discriminate between closely …

Investigating Telomere Lengths In Chestnut-Crowned Babblers, Gabriella Rose Beberg

Honors Thesis

Telomeres are chromosomal elements that protect and maintain genes as DNA replicates in many organisms. As individuals age and DNA replicates, telomeres often shorten; thus, telomere length often corresponds with an individual’s lifespan, and early-life decreases in telomere length can be predictive of longevity. Here, I investigated the relationship between telomere length and developmental environment in a cooperatively breeding species, the chestnut-crowned babbler (Pomatostomus ruficeps; CCB). Cooperative species are unique, as some individuals give up their own breeding opportunities to help rear the offspring of others; further, cooperative breeding systems generate considerably more variation in adult carers, which …

Acid Attack: How Escherichia Coli Strains Resist Acid Stress, Lindsey Miller

Honors Theses

The systems used by Escherichia coli to combat heightened levels of acidity within their environment are varied and complex. Four distinct systems used by E. coli to resist acid-induced stress were identified in 2004 by Foster (1), though six now are known today. These systems include the glucose-repressed, glutamate-dependent, arginine-dependent, lysine-dependent, ornithine-dependent, and serine-dependent acid resistance systems. Each system is also known by its corresponding abbreviation, AR1-AR6. What is known about each system varies due to identification date, complexity of the pathway, and amount of research completed. Within this paper, each system will be identified and the pathway defined, combining …

Pathogenicity Of Acinetobacter Calcoaceticus, Kaitlan A. Sullivan

MUSC Theses and Dissertations

Acinetobacter is a genus of gram-negative bacteria that have been appearing frequently in hospitals contributing to infections in the blood, lungs, urinary tract, and other parts of the body. It infects patients with weakened immune systems that are placed on ventilators, after the use of catheters, or have any other open wounds produced by prolonged hospital stays. This genus of bacteria is problematic due to its high probability of becoming resistant to multiple classes of antibiotics. Thus, we are determining the pathogenicity of clinical isolates of Acinetobacter calcoaceticus using the organism Caenorhabditis elegans as a model.

We are testing …

Hazards And Perceptions Of Cigarette And E-Cigarette Waste, Jossalyn Rogalski

Honors Theses

No abstract provided.

Human Motion Detection Evaluated Through An Evoked Cortical Potential Frequency Spectrum, Howard E. Painter

USF Tampa Graduate Theses and Dissertations

Electrical potentials were recorded from scalp of normal male subjects while they were viewing continuously moving sinusoidal gratings. Responses from the occipital cortex were amplified, digitized, stored and then transformed from the time domain to the frequency domain using a microcomputer based Fast Fourier Transform algorithm. High frequency components (Beta Activity) of the resulting power spectrum were analyzed for evidence on neural generators (electrical sources) in the striate cortex driven presumably by transient-cells (Y-cells or Magnocellular) responding to the continuously moving grating. Several stimulus parameters were examined: angular velocity, spatial frequency, direction (orientation), color, and intensity. A16 Hz component of …

Violence Against Healthcare Workers, Nichole Osgood

Honors Theses

Workplace violence is any act or threat of physical violence, harassment, intimidation, or other threatening disruptive behavior that occurs at work (US Department of Labor, 2023). There are a handful of different types of workplace violence that include but are not limited to physical violence, verbal abuse and threats, sexual harassment, and psychological trauma (US Department of Labor, 2023). Workplace violence, a multifaceted phenomenon, is not a new concern, but its pervasiveness and intensity in healthcare settings have reached alarming proportions in recent years. In a meta-analysis, it was noted that workplace violence against healthcare workers of any kind was …

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 …

The Unexpected Significance Of Myosin A In Organization Of M-Line Protein Unc-89/Obscurin Within Striated Muscle Cells Of Caenorhabditis Elegans, Kar Men Lee

Honors Theses

This research investigates the unexpected significance of Myosin A in the organization of M-line protein UNC-89/obscurin within striated muscle cells of the nematode Caenorhabditis elegans (C. elegans). The study employs immunofluorescence techniques to examine the spatial and temporal dynamics of UNC-89/obscurin and Myosin A during embryonic development. The sarcomere, a fundamental unit in muscle cells, is governed by the 'sliding filament model,' where the M-line serves as a crucial anchor for Myosin A. This research seeks to understand the relationship between muscle function in humans and C. elegans, utilizing the latter's simple anatomy and genetic tractability. The …

We Are The Reason We Stand Still In The Face Of Climate Change., Sydney Hemp

Honors Theses

Many different factors can impact the way any information is received but it is especially important to see how scientific information is received because it is often backed up by a great deal of evidence, especially in the case of global climate change. Many of these factors have nothing to do with science and everything to do with social influences, political parties, and other demographic measures. Discussion of these relationships is important when discussing communication in a broad sense, but it can be even more important when bringing up things like global climate change, which has become a political topic …

Elucidating The Relationships Between Spider Size, Joint Stiffness, And The Mechanical Frequency Response Of The Body, Reese L. Gartly

Electronic Thesis and Dissertation Repository

Spiders use vibrations to sense their surroundings. It has been suggested that the vibration perception in spiders may be altered by the mechanics of the body. I studied the biomechanics of spiders, at the level of leg joints and the whole body. To study joints, I quantified the allometry of leg joint stiffness in spiders. I found that the stiffness of spider joints increased nearly isometrically with increasing body mass, partly by having shorter and thicker leg segments and also by other unknown means. Using these data, I developed empirically validated biomechanical models which predicted the effects of mechanics on …

Psammocora Stellata Distribution At Devil's Crown, Floreana Island, Galápagos Islands, Ecuador, María José Guarderas Sevilla

All HCAS Student Capstones, Theses, and Dissertations

In the Galápagos Archipelago, the free-living nodular coral Psammocora stellata is a common species that does not form reef structures. However, it is a key component of the ecosystem by increasing habitat complexity and, consequently, species diversity. This species experienced a drastic decline in Devil’s Crown channel, Floreana Island, where it disappeared after the 1982-83 El Niño-Southern Oscillation, presumably by displacement of unattached colonies by strong surface waves and currents. This assemblage has now recovered to pre-impact levels. A combination of underwater photoquadrats from 2007 and 2009 and recent (2023) orthomosaics were used to determine changes in coral densities and …

Modeling A Parkinson’S Disease Like State In Zebrafish Larvae Utilizing 6-Hydroxydopamine, Adrian Romero

Biology Theses

Parkinson's’ disease (PD) is a neurodegenerative disorder characterized by the loss of midbrain dopaminergic (mDA) neurons that currently has no cure. It is primarily characterized in patients by motor symptoms that include but are not limited to: tremor at rest, rigidity, akinesia, and postural instability affecting the quality of life for over 8.5 million people worldwide. The neurotoxin 6-hydroxydopamine (6-OHDA) has been used to induce a Parkinson’s disease-like state in several animal models; however, assessment of 6-OHDA use in zebrafish demonstrated a lack of consensus on method and utility. We determined an optimized protocol utilizing 6-OHDA to produce a PD-like …

Impacts Of Environmental Stressors On Native South Dakota Amphibian Physiology And Survival, Danielle Jean Galvin

Dissertations and Theses

Amphibian populations around the world are declining, with some of the most likely drivers behind these declines including emerging infectious diseases and environmental contaminants. To address major gaps in the current literature, I sought to evaluate the effect of two major environmental stressors on various aspects of amphibian physiology: emerging infectious diseases and environmental contaminants. Emerging infectious diseases of amphibians include fungal, viral, and parasitic pathogens which have expanded in host range, either geographically or in competent host species. Environmental contaminants include chemicals which may be naturally occurring in the environment, or which may be introduced to the environment, often …

Variation In Bat Activity Across Upland Embedded Wetlands In The Cumberland Ranger District Of The Daniel Boone National Forest, Brittany Ryan

Online Theses and Dissertations

Within the Daniel Boone National Forest (DBNF) in Kentucky, over 800 upland-embedded wetlands (UEWs) have been constructed in past decades to provide habitat for bats and other wildlife. This research focused on identifying differences in bat activity and occupancy across natural and constructed UEWs. Acoustic detectors were deployed at 9 natural and 31 constructed UEWs across the Cumberland Ranger District of the DBNF. Each UEW was surveyed across 3 intervals from May – August 2022, and each recording session spanned >3 consecutive nights, yielding a total of 413 detector nights. Occupancy modeling and AIC model selection were used to evaluate …

Lizard Communities In A Shifting Landscape: The Current State Of Insectivorous Lizard Communities In The Jornada Basin Between Grassland, Mesquite Dune, And Creosote Bush Habitats In A Semi-Arid Landscape Undergoing Shrubification, Julie Marie Schlichte

Open Access Theses & Dissertations

Lizard communities in arid lands can act as model systems of how diversity and abundance are impacted in the face of ongoing climate variability and change, as they are sensitive to shifts in precipitation, temperature, and changing vegetation structure. The main research question we hope to answer is how the community composition of lizards varies between dominant vegetation types (Mesquite dunes, grasslands, and Creosote Bush flats). Nine sites (3 of each dominant vegetation type) with 16 pitfall traps each (n = 144) were surveyed from June 2016 -- June 2017. 12 lizard species were captured, consisting of 923 total captures …

Activity Patterns Of Whiptail Lizards (Aspidoscelis) Found In The Northern Chihuahuan Desert, Guillermo Alvarez

Open Access Theses & Dissertations

Traditional lizard pitfall traps were modified to allow organisms to escape, while collecting valuable ecological data. Modified camera traps were capable of detecting the same species as traditional traps in a semi-arid environment, without posing the associated mortality risks. Pitfall-camera traps were used to sample the activity of the Side-blotched Lizard (Uta stansburiana) and the Southwestern Fence Lizard (Sceloporus cowlesi) in an urban wetland during four continuous years. Evaluations on activity pattern and the activity overlap between the two species revealed extensive overlap, with minor but significant seasonal shifts mediating coexistence. Traps were also effective at detecting other reptiles, invertebrates, …

The Role Of The Cholesterol Synthesis Pathway In Primitive Erythropoiesis, Jose Hernandez

Open Access Theses & Dissertations

Erythropoiesis is the process by which new red blood cells (RBCs) are formed and defects in this process can lead to anemia or thalassemia. The GATA1 transcription factor is an established mediator of RBC development. However, the upstream mechanisms that regulate the expression of GATA1 are not completely characterized. Cholesterol is 1 potential upstream mediator of GATA1 expression because previously published studies suggest that defects in cholesterol synthesis disrupt RBC differentiation. Here we characterize RBC development in a zebrafish harboring a single missense mutation in the hmgcs1 gene (Vu57 allele). Hmgcs1 encodes the first enzyme in the cholesterol synthesis pathway …

Human-Bat Interactions In A Disease Emergence Hotspot: Implications For Human Health And Bat Conservation, Reilly Tempest Jackson

Graduate Theses and Dissertations

Bats are an ecologically important taxon that can host zoonotic pathogens. Globally, many bat species are synanthropic and live closely with humans, often roosting in man-made structures. The spatial overlap between humans and bats creates opportunities for human-bat contact, which can lead to human exposure to bat-borne pathogens and conflicts that cause bat mortality. Despite this risk, little is known about the drivers and characteristics of these human-bat interactions in buildings and work is needed to understand this aspect of the wildlife-urban interface. In Chapter I, I present a literature review that identifies the geographic and taxonomic trends in reported …

First Genomic Resource For An Endangered Neotropical Mega-Herbivore: The Complete Mitochondrial Genome Of The Forest-Dweller (Baird's) Tapir (Tapirus Bairdii), Caroline C. Ennis

Honors College Theses

Baird's tapir, or the Central American Tapir Tapirus bairdii (family Tapiridae), is one of the largest mammals native to the forests and wetlands of southern North America and Central America and is categorized as `endangered' on the 2014 IUCN Red List of Threatened Species. This study reports, for the first time, the complete mitochondrial genome of T. bairdii and examines the phylogenetic position of T. bairdii amongst closely related species in the same family and order to which it belongs using mitochondrial protein-coding genes (PCG's). The circular, double-stranded, A-T rich mitochondrial genome of T. bairdii is 16,697 bp in length …

Determining The Effects Of Glycocalyx Modifications On The Electrophysical Properties Of Human Mesenchymal Stem Cells, Rominna E. Valentine Ico

Electronic Theses, Projects, and Dissertations

Human mesenchymal stem cells (hMSCs) have gained popularity in clinical trials due to their multipotent differentiation characteristics, ability to secrete bioactive molecules, migrate into diseased or damaged tissues, and their immunosuppressive properties. HMSC cultures are heterogeneous, containing stem cells, partially differentiated progenitor cells, and fully differentiated cells. One of the major challenges with hMSCs therapeutic potential is the inability to select specific cell subpopulations due to an insufficient number of biomarkers. Often the biomarkers used, like those for fluorescence-activated cell sorting, are not sufficient to define hMSCs because they overlap with other cell types. Consequently, there is a need to …

Seagrass Epibiont Biodiversity In The Northern Gulf Of Mexico, Kathryn Wyssmann

University of New Orleans Theses and Dissertations

Epibionts on seagrass leaves contribute substantially to productivity and trophic interactions in seagrass ecosystems. Differences in epibiont assemblages and factors that contribute to epibiont diversity have been little studied on the seagrass Halodule wrightii in the northern Gulf of Mexico (nGoM). We used a metabarcoding approach to describe epibiont assemblages on H. wrightii leaves in four bays across the nGoM and to test whether epibiont assemblages differed spatially at local levels (within bays) or regional levels (from west to east). Furthermore, we tested if epibiont diversity was related to environmental conditions and/or seagrass productivity. Epibiont assemblages differed significantly between bays …

Elucidating Aposematic Patterns In North American Hylids, Joseph S. Cannizzaro Iv

Theses and Dissertations

Recognizing form and function of animal defenses is paramount to understanding the ecological and evolutionary forces behind predator and prey dynamics. Color patterns are strongly related to defensive strategies in animals. Some rely on camouflage to avoid detection, while others are brightly colored and conspicuously signal their noxiousness to potential predators. Still others combine cryptic dorsal coloration with colorful patches that are concealed in resting position but are facultatively unveiled by special behavior or simply during activity. Such hidden conspicuous color patches may be an intermediate stage in the evolution from camouflage to aposematism. We investigated whether conspicuously colored thighs …

How Beavers (Castor Canadensis) Affect Habitat Availability For Two Native Oregon Turtles: Actinemys Marmorata And Chrysemys Picta Bellii, Rodé Krige

University Honors Theses

Oregon is home to two native freshwater turtle species: the northwestern pond turtle and the western painted turtle. Both turtles are Oregon conservation strategy species with a status rating of sensitive, indicating declining populations. Oregon’s decline in these turtle’s populations is thought to be predominantly due to loss and degradation of habitat that results from development and urbanization. Beavers’ ability to dam streams and create ponds may be creating habitat usable by turtles, but the relationship is under-studied. This study assessed water temperature, basking habitat, and overall turtle habitat suitability at beaver-dammed and control ponds in Portland, Oregon. Average basking …

Development Of Synthetic Glycobiomarkers For The Follow-Up Of Chagas Disease Chemotherapy And Serological And Molecular Assays For Evaluation Of Trypanosoma Cruzi Infections In The U.S-Mexico Border, Igor L. Estevao

Open Access Theses & Dissertations

Chagas disease (CD), caused by the protozoan parasite Trypanosoma cruzi, affects 7-8 million people worldwide. Lately, the disease has been spread to nonendemic countries and regions, like the U.S. and Europe. The disease can be divided into two phases: the acute and chronic phases, which continue for years or even decades. There are two available drugs for CD treatment: benznidazole (BNZ) and nifurtimox (NFX). These drugs are highly effective in the acute phase but less efficient in the chronic stage. Other limitations of these drugs are their toxicity, leading to serious adverse events and premature treatment termination. Newer clinical trial …

Proteomic Analysis Reveals Fkbp51 And Fkbp52 Interactors Implicated In Androgen Receptor-Mediated Castration Resistant Prostate Cancer, Olga Soto

Open Access Theses & Dissertations

Aberrant signaling mechanisms by the Androgen Receptor (AR) are attributed as the main culprits for the initiation and progression of prostate cancer (PCa). Due to its dependence on androgens, research efforts have focused on developing strategies to directly target androgen-mediated receptor activity. However, given the recurrence and treatment resistance of PCa despite androgen targeted therapies, recent efforts have shifted to find novel targets against the disease. These efforts include further revealing the molecular components and their mechanisms underlying AR signaling in both normal and disease physiological settings. Hence, our lab's work is focused on characterizing and targeting molecular chaperones that …