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Full-Text Articles in Life Sciences

Impacts Of Environmental Stressors On Native South Dakota Amphibian Physiology And Survival, Danielle Jean Galvin Dec 2023

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 …


Interpretable Mechanistic And Machine Learning Models For Pre-Dicting Cardiac Remodeling From Biochemical And Biomechanical Features, Anamul Haque Dec 2023

Interpretable Mechanistic And Machine Learning Models For Pre-Dicting Cardiac Remodeling From Biochemical And Biomechanical Features, Anamul Haque

All Dissertations

Biochemical and biomechanical signals drive cardiac remodeling, resulting in altered heart physiology and the precursor for several cardiac diseases, the leading cause of death for most racial groups in the USA. Reversing cardiac remodeling requires medication and device-assisted treatment such as Cardiac Resynchronization Therapy (CRT), but current interventions produce highly variable responses from patient to patient. Mechanistic modeling and Machine learning (ML) approaches have the functionality to aid diagnosis and therapy selection using various input features. Moreover, 'Interpretable' machine learning methods have helped make machine learning models fairer and more suited for clinical application. The overarching objective of this doctoral …


Human-Bat Interactions In A Disease Emergence Hotspot: Implications For Human Health And Bat Conservation, Reilly Tempest Jackson Dec 2023

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 …


Relative Hepatotoxocity, Carcinogenicity, And Toxicogenomics Of Select Dehydropyrrolizidine Alkaloids In Mice, Michael J. Clayton Dec 2023

Relative Hepatotoxocity, Carcinogenicity, And Toxicogenomics Of Select Dehydropyrrolizidine Alkaloids In Mice, Michael J. Clayton

All Graduate Theses and Dissertations, Fall 2023 to Present

Dehydropyrrolizidine alkaloids are arguably the most important plant derived toxins in terms of impact on human and animal health. Dehydropyrrolizidine alkaloids are a large group of chemically related compounds found in 3% of flowering plants worldwide. Human exposure occurs from ingestion of herbal products including teas supplements or contaminated grain. Animals are exposed through contaminated feed or grazing. There are at least 350 identified toxic PAs, from more than 6,000 plants. The toxins primarily cause liver damage, but some are proven to cause cancer. Indidvidual dehydropyrrolizidine alkaloids vary in their toxic effects. Riddelliine is the only dehydropyrrolizidine alkaloid with extensive …


Assessing Copd Care Quality In A Rural Ontario Primary Care Clinic: A Retrospective Chart Review, Daniel Henke Oct 2023

Assessing Copd Care Quality In A Rural Ontario Primary Care Clinic: A Retrospective Chart Review, Daniel Henke

Electronic Thesis and Dissertation Repository

Background: Primary chronic obstructive pulmonary disease (COPD) care may be worse in rural versus more urban environments.

Purpose: To evaluate the quality of COPD care in a rural Ontario primary care clinic.

Methods: A 12-month retrospective chart review study was conducted between June 2022 and January 2023 at a Goderich, Ontario primary care clinic. Electronic medical records (EMRs) were randomly selected for inclusion. Baseline sociodemographic (e.g., occupation) and health (e.g., smoking status) characteristics were extracted as well as information regarding COPD care received (i.e., Health Quality Ontario [HQO] Quality Standard [QS] indicators; n=33. The primary study outcome was overall proportion …


Using Noninvasive Calibrated Cuff Plethysmography To Observe The Effects Of Cold-Water Immersion On Arterial Compliance, Rita M. Grigorian Oct 2023

Using Noninvasive Calibrated Cuff Plethysmography To Observe The Effects Of Cold-Water Immersion On Arterial Compliance, Rita M. Grigorian

Master's Theses

As the prevalence of cardiovascular diseases continues to exponentially grow in populations across the globe, the necessity of determining underlying factors, effective methods of diagnoses, and universally available preventive measures also grows. Early detection of endothelial dysfunction, a proven precursor of cardiovascular diseases, can be extremely impactful in encouraging preventative measures and early intervention before medical conditions become chronic. In recent years, ice plunging, a form of cryotherapy involving full body immersion in cold water, has gained popularity within circles of fitness and health practitioners, gaining the interest of people of all backgrounds. Certain parallels observed between the human physiological …


Muscle Defects Lead To Skeletal Deformities In A Zebrafish Model Of Distal Arthrogryposis, Emily A. Tomak Aug 2023

Muscle Defects Lead To Skeletal Deformities In A Zebrafish Model Of Distal Arthrogryposis, Emily A. Tomak

Electronic Theses and Dissertations

Distal Arthrogryposis Type 1 (DA1) involves mild muscle weakness and limb skeletal abnormalities thought to be caused by paralysis in utero. Why the limbs are particularly affected in DA1 and the degree of paralysis that leads to these skeletal deformities in utero remains unclear. Several muscle genes are known to cause DA1, including MYLPF (myosin light chain phosphorylatable), which encodes a myosin light chain protein that binds close to the force-generating head of myosin heavy chains. The zebrafish mylpfa-/- mutant displays a phenotype consistent with DA1, including impaired myosin activity, reduced muscle force overall, and complete fin paralysis. I …


Effectiveness Of Intervention Studies Based On Diet And/Or Physical Activity In Treatment, Prevention, And Management Of Diabetes Among South Asians: A Systematic Review, Ishaan Arora Aug 2023

Effectiveness Of Intervention Studies Based On Diet And/Or Physical Activity In Treatment, Prevention, And Management Of Diabetes Among South Asians: A Systematic Review, Ishaan Arora

Theses and Dissertations

The purpose of this study was to describe diet and/or physical activity-based interventions and their control in cardiometabolic risk factors of diabetes for the South Asian (SA) population. A systematic review was conducted in accordance with the PRISMA guidelines. Seventeen randomized control trials meeting the inclusion criteria were included for analysis. Interventions with type-2 diabetic SA showed significant improvements in HbA1c% (4/5 studies), fasting blood glucose (3/4 studies), and postprandial glucose (2/2 studies). Interventions with at-risk/prediabetic and non-diabetic SA showed a modest change in overall outcomes, with significant change reported for post-prandial insulin (3/4 studies), BMI and weight (2/4 studies), …


Evaluation Of The Virulence Potential Of Avian Pathogenic Escherichia Coli Isolated From Broiler Breeders With Colibacillosis In Mississippi, Jiddu Joseph Aug 2023

Evaluation Of The Virulence Potential Of Avian Pathogenic Escherichia Coli Isolated From Broiler Breeders With Colibacillosis In Mississippi, Jiddu Joseph

Theses and Dissertations

Avian pathogenic Escherichia coli (APEC) is a bacterium that is responsible for colibacillosis in birds. However, information about broiler breeder APEC isolates is limited, but the data is critical due to the transfer of this bacteria down the production pyramid to progenies resulting in high mortality. Therefore, we evaluated the phenotypic virulence characteristics of 28 isolates using embryo lethality and day-old chick challenge assays. Also, the in vitro adhesion and invasion potential of selected nine isolates were identified. Results showed more than 1/3rd of the isolates were highly virulent and the virulence increased as the number of virulence-associated genes …


Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke Aug 2023

Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke

Electronic Theses and Dissertations

The number of daily bacterial infections is climbing and the CDC explains that this is due to the antibiotic-resistant threat in the United States. Finding a faster way of bacterial identification is necessary as it currently takes 1-4 days for a medical lab to culture and identify bacteria. Photoacoustic flow cytometry (PAFC) can be used as an alternative method resulting in swift identification within an hour (Edgar, 2019). Pseudomonas aeruginosa, cell line PA01, will be coated in up to a few hundred red dyed phages making it detectible by the photoacoustic flow cytometry system. Bacteriophages (phages) are viruses that …


Sex Differences In Mood And Anxiety-Related Outcomes In Response To Adolescent Nicotine Exposure, Tsun Hay Jason Ng Aug 2023

Sex Differences In Mood And Anxiety-Related Outcomes In Response To Adolescent Nicotine Exposure, Tsun Hay Jason Ng

Electronic Thesis and Dissertation Repository

Nicotine dependence is causally linked to increased risk of mood/anxiety disorders in later life. Females are reported to experience a higher prevalence of anxiety/depressive disorders and challenges in smoking cessation therapies, suggesting a potential sex-specific response to nicotine exposure and mood/anxiety disorder risk. However, pre-clinical evidence of sex-specific responses to adolescent nicotine exposure is unclear. Thus, to determine any sex differences in anxiety/depressive-related outcomes, adolescent male and female Sprague Dawley rats received nicotine (0.4 mg/kg; 3x daily) or saline injections for 10 consecutive days, followed by behavioural testing, in-vivo electrophysiology and Western Blot analyses. Our results revealed that adolescent nicotine …


Investigation Of Orthohantavirus Genetics In Rodent Reservoirs And Clinical Samples, Samuel M Goodfellow Aug 2023

Investigation Of Orthohantavirus Genetics In Rodent Reservoirs And Clinical Samples, Samuel M Goodfellow

Biomedical Sciences ETDs

Orthohantaviruses are negative-sense, single stranded RNA viruses with trisegmented genomes that can cause severe disease in humans and are carried by several host reservoirs throughout the world. In the United States, Sin Nombre orthohantavirus (SNV) is the primary cause of hantavirus cardiopulmonary syndrome (HCPS) with a fatality rate of ~36% and the highest cases occuring in the southwest region. The primary SNV host reservoir is thought to be the western deer mouse, Peromyscus maniculatus, however it has been shown that other rodents can carry different orthohantaviruses. We designed a pan-orthohantavirus detection tool to survey several small mammal populations throughout New …


Investigating The Role Of Il-10 Producing Nkt Cells In Prevention Of Graft Versus Host Disease, Drew Boagni Aug 2023

Investigating The Role Of Il-10 Producing Nkt Cells In Prevention Of Graft Versus Host Disease, Drew Boagni

Dissertations & Theses (Open Access)

The standard curative treatment for hematologic malignancies is allogeneic stem cell transplantation (ASCT), in which the patient’s immune system is replaced with that of a healthy donor. This can lead to cure through the graft versus leukemia (GVL) effect but can also cause graft versus host disease (GVHD), which is characterized by systemic inflammation and organ damage mediated by dysregulated donor T cells. Preclinical studies have shown invariant natural killer T cells (iNKT) cells can prevent GVHD while preserving GVL. iNKT cells are unconventional T cells which recognize glycolipid antigens presented in the context of CD1d. Upon activation, they secrete …


Black Bear Population Health Monitoring In The Southeast, Kathleen Elizabeth Riese Aug 2023

Black Bear Population Health Monitoring In The Southeast, Kathleen Elizabeth Riese

Masters Theses

Recent growth of the American black bear (Ursus americanus) population in the southeast raises concerns about the potential spread of density-dependent diseases among bears, particularly sarcoptic mange. However, research on the health of bears in this area is limited. We analyzed samples from 169 bears in the region. We performed Knotts tests, skin scrapes, fecal floats; Canine adenovirus (CAV), canine parvovirus (CPV), canine distemper virus (CDV), and Toxoplasma gondii serology, Trypanosoma, Rickettsia rickettsii, and apicomplexan PCR, and identified ecto- and endoparasites found grossly or histologically. We found that 69% (63 of 91) had microfilaria; genetic analysis identified …


The Prevalence Of Diabetes In Juveniles, Tatyana Johnson Jul 2023

The Prevalence Of Diabetes In Juveniles, Tatyana Johnson

Graduate Student Dissertations, Theses, Capstones, and Portfolios

Diabetes mellitus, simply known as diabetes, is a metabolic disorder that impacts how the body makes use of glucose or blood sugar. Glucose is the primary supply of energy for the body’s cells, which is controlled by insulin, a pancreatic hormone. Diabetes results in high blood glucose levels (hyperglycemia), which are caused by either insufficient insulin production by the pancreas or ineffective insulin utilization by the body (Dean & McEntyre, 2004). Although there are several types of diabetes, the two main types are type 1 and type 2. Type 1, also known as juvenile diabetes, is an inflammatory condition in …


The Combined Effects Of Physical Exercise And Cognitive Training On Gait Speed And Primary Motor Cortex Metabolism In Individuals With Mild Cognitive Impairment: A 1h-Mrs Analysis, Jack Thomas Emsey Elkas Jul 2023

The Combined Effects Of Physical Exercise And Cognitive Training On Gait Speed And Primary Motor Cortex Metabolism In Individuals With Mild Cognitive Impairment: A 1h-Mrs Analysis, Jack Thomas Emsey Elkas

Electronic Thesis and Dissertation Repository

Mild cognitive impairment (MCI) is a transitional stage before dementia. Altered gait in MCI has been associated with progression to dementia. Using magnetic resonance spectroscopy, a relationship between primary motor cortex (M1) neurochemistry and dual task gait speed has been reported in MCI. Interventional research suggests exercise, cognitive training, and vitamin D supplementation may benefit MCI, yet the combined effect of these treatments on gait speed and M1 metabolism is unknown. Participants with MCI (N=75) were assigned to one of five intervention arms and dual task cost on gait speed and M1 metabolism was assessed before and five months after …


Complement System In Multiple Sclerosis: Its Role In Disease Course And Potential As A Therapeutic Target, Michael R. Linzey Jun 2023

Complement System In Multiple Sclerosis: Its Role In Disease Course And Potential As A Therapeutic Target, Michael R. Linzey

Dartmouth College Ph.D Dissertations

Multiple sclerosis (MS) is a clinically heterogeneous neurological condition characterized by neuroinflammation and neurodegeneration. Relapsing-remitting MS, defined by inflammatory attacks, is the most common initial form of MS and there are currently 23 FDA-approved treatments for these patients. These therapies work primarily by reducing inflammation in the CNS; they do not work well in progressive disease. Therefore, an unmet medical need exists for effective therapeutic options to treat progressive MS (PMS).

In MS, intrathecal immunoglobulins synthesis (IIgS) correlates with disease progression. My goals for this dissertation were to establish the pathological role of IIgS and identify new potential therapeutic …


Mining Sars-Cov-2 Phylogenetic Trees To Estimate Circulating Infections And Patterns Of Migration, Erin V. Brintnell Jun 2023

Mining Sars-Cov-2 Phylogenetic Trees To Estimate Circulating Infections And Patterns Of Migration, Erin V. Brintnell

Electronic Thesis and Dissertation Repository

The SARS-CoV-2 pandemic led to the formation of very large databases of genomic viral data. These databases contain information on transmission dynamics, emergence and evolution of SARS-CoV-2. However, extracting this information from sequences is difficult, as most methods of analyzing viral genomes were developed for smaller data sets. Therefore, my objective was to develop new fast estimators of the number of infections (I) and the rate of migration based on simple features of SARS-CoV-2 phylogenies.

I simulated pathogen evolution using a susceptible-exposed-infectious-recovered (SEIR) model of pathogen spread, reconstructing evolution using CoVizu. For simulations of I, I varied the total number …


Role Of Chronic Stress-Induced Neuroinflammation In Rodent Locus Coeruleus Physiology And Anxiety-Like Behaviors, Arthur Anthony Alfonso Reyes Jun 2023

Role Of Chronic Stress-Induced Neuroinflammation In Rodent Locus Coeruleus Physiology And Anxiety-Like Behaviors, Arthur Anthony Alfonso Reyes

Graduate School of Biomedical Sciences Theses and Dissertations

The locus coeruleus (LC), the primary site of brain norepinephrine (NE), is a key anatomical brain region implicated in the stress response. Stress is a neuroendocrine physiologic response to a stressor that promotes organism survival through adaptive change and restoration of homeostasis. The central stress response, which drives behavioral and physiological change, is primarily mediated by activating the hypothalamic-pituitary-adrenal (HPA) axis. While advantageous in the short term, chronic stress exposure can lead to HPA axis and LC dysregulation, which are thought to contribute to the etiology of anxiety disorders. Previous studies demonstrate the effects of acute stress in increasing LC …


Investigating The Mammillary Bodies As An Early Target Of Alzheimer's Disease, Cole Martinson Jun 2023

Investigating The Mammillary Bodies As An Early Target Of Alzheimer's Disease, Cole Martinson

University Honors Theses

Alzheimer's disease (AD) is the most common form of dementia. With minimal treatment options and no cure, developing a deeper understanding of the pathology of the disease is crucial. For nearly four decades, the accumulation of beta-amyloid (Aβ) plaques has been correlated with the disease and its progression. Previous studies mapping this accumulation show that the mammillary bodies (MB) are an early target of the disease. Glutamatergic neurons are of key interest due to their prevalence in the central nervous system, specifically the MB. To understand the effects of AD on the glutamatergic system, we used vesicular glutamate transporter 2 …


The Role Of Complement In Stroke And Traumatic Brain Injury, Christine Couch May 2023

The Role Of Complement In Stroke And Traumatic Brain Injury, Christine Couch

MUSC Theses and Dissertations

Brain and neural injury are a non-specific disease category that includes traumatic brain injury (TBI) and stroke. Both TBI and stroke are common, costly, and leading causes of severe disability in adults. Both stroke and TBI are responsible for substantial disability in working age adults, with stroke being the second leading cause of death worldwide [1] and TBI a major cause of disability in people younger than their 40's [2]. The immune response after brain injury is multifactorial and involves both local and systemic events at the cellular and molecular level. The complement system is a component of both the …


Evolution And Epidemiology Of Channel Catfish Virus (Ccv), Arun Venugopalan May 2023

Evolution And Epidemiology Of Channel Catfish Virus (Ccv), Arun Venugopalan

Theses and Dissertations

Channel catfish virus disease (CCVD) is the principal viral disease in the United States catfish industry. The CCVD is caused by channel catfish virus (CCV), with mortality reaching up to 100% in fingerlings. CCV is assigned taxonomically to the family Alloherpesviridae, genus Ictalurivirus, species Ictalurid herpesvirus 1 (IcHV-1). To date, virulence, immunogenicity, and genome plasticity of the CCV field isolates have not been investigated. Three genotypes of CCV (IcHV-1A, IcHV-1B, and BCAHV) were identified using restriction fragment length polymorphism (RFLP) analysis. Virulence assessment of three representative isolates of RFLP groups suggests that IcHV-1B (pooled survival [mean ± SE]: 58.3% ± …


Impacts Of Dietary Restriction On A Drosophila Model Of Werner Syndrome, Eileen Sember May 2023

Impacts Of Dietary Restriction On A Drosophila Model Of Werner Syndrome, Eileen Sember

College of Arts & Sciences Senior Honors Theses

Werner syndrome (WS) is an autosomal recessive disorder that results in premature aging and occurs in 1 in 1,000,0000 to 1 in 10,000,000 people. In humans, WS is the result of mutations that render the WRN gene, that contains a helicase and an exonuclease domain, non-functional. Currently, there is no cure for WS in humans, making dietary and lifestyle interventions attractive for increasing the quality and longevity of lives. Diet restriction (DR) has been shown to extend the lifespan of several model organisms, including Drosophila melanogaster, making it a strong candidate for WS treatment. In this thesis, mutant flies …


Sexual Dimorphism Of Glomerular Capillary Morphology In Rats, Zackarias Coker May 2023

Sexual Dimorphism Of Glomerular Capillary Morphology In Rats, Zackarias Coker

Undergraduate Honors Theses

Chronic kidney disease (CKD) progresses faster in males than females; however, the underlying mechanisms remain poorly understood. Sex differences in glomerular capillary morphology has been hypothesized to contribute, in part, to the increased susceptibility to hypertension-induced renal injury and CKD progression in males, but this has not been investigated. The goal of the present study was to assess glomerular capillary morphology in male vs. female rats with intact kidneys and after uninephrectomy (UNX). We hypothesized that glomerular capillary radii (RCAP) and length (LCAP) would be greater in male rats.

Male (n=4) and female (n=4) with intact …


Evaluation Of The Effect Of Enterococcus Cecorum Exposure During Late Embryogenesis On Systemic Disease And Early Performance In Broiler Chickens, Marcela Arango May 2023

Evaluation Of The Effect Of Enterococcus Cecorum Exposure During Late Embryogenesis On Systemic Disease And Early Performance In Broiler Chickens, Marcela Arango

Graduate Theses and Dissertations

The objective of this thesis was to investigate the effects of Enterococcus cecorum (EC) administration into the amnion at day 18 of embryogenesis on performance and septicemia development in broiler chickens. Chapter I consists of a brief overview of the thesis. Chapter II provides a literature review on EC-related disease in broiler chickens and methods to isolate, detect, and differentiate between commensal and pathogenic strains of EC. Chapter III consists of a study conducted to determine if different EC strains isolated from field cases that exhibited septicemia and high mortality impacted hatchability, livability, organ colonization, and early performance in broiler …


Immunomodulatory Effects Of Resolvin D2 In A Model Of Infection, Prem Yugandhar Kadiyam Sundarasivarao May 2023

Immunomodulatory Effects Of Resolvin D2 In A Model Of Infection, Prem Yugandhar Kadiyam Sundarasivarao

Graduate School of Biomedical Sciences Theses and Dissertations

Dysregulated hyperinflammatory host immune response to underlying bacterial infections is a characteristic of sepsis. In sepsis, bacteria often trigger abnormal hyperinflammatory responses which can cause multiple organ failure and if sustained can lead to an immunosuppressive phase where the host is susceptible to secondary infections caused by opportunistic bacteria like Pseudomonas aeruginosa (P. aeruginosa). In our studies, we used a 2-hit model of cecal ligation and puncture (CLP) followed by P. aeruginosa secondary lung infection to investigate cellular and molecular mechanisms in the beneficial action of resolvin D2 (RvD2). Resolvins of the D-series are a group of fatty acids known …


The Cx3cl1-Cx3cr1 Chemokine Axis Contributes To Tumor Immune Evasion And Its Blockade Enhances Responses To Anti-Pd-1 Immunotherapy, Apoorvi Chaudhri May 2023

The Cx3cl1-Cx3cr1 Chemokine Axis Contributes To Tumor Immune Evasion And Its Blockade Enhances Responses To Anti-Pd-1 Immunotherapy, Apoorvi Chaudhri

Dissertations & Theses (Open Access)

CX3CL1 secreted in the tumor microenvironment serves as a chemoattractant playing a critical role in metastasis of CX3CR1 expressing cancer cells. While CX3CR1 can be expressed in both cancer and immune-inhibitory myeloid cells to facilitate their migration, the mechanisms employed by this axis on these cells to mediate immune suppression remain poorly understood. Here, we explore the immune evasion strategies implemented by this axis and find that it initiates a resistance program in cancer cells that results in 1) facilitation of tumor cell migration, 2) secretion of soluble mediators to generate a pro-metastatic niche, 3) secretion of mediators to attract …


An Ecological Perspective Of American Rodent-Borne Orthohantavirus Surveillance, Nathaniel Mull May 2023

An Ecological Perspective Of American Rodent-Borne Orthohantavirus Surveillance, Nathaniel Mull

Graduate Theses and Dissertations

Orthohantaviruses are a global group of viruses found primarily in rodents, though several viruses have also been found in shrews and moles. Many rodent-borne orthohantaviruses are capable of causing one of several diseases in humans, and the mortality associated with these diseases ranges from < 0.1% - 50% depending on the specific etiological virus. In North and South America, orthohantavirus research was ignited by an outbreak of severe disease in the Four Corners region of the United States in 1993. However, despite the discovery of over 20 orthohantaviruses in the Americas, our understanding of orthohantavirus ecology and virus-host dynamics in this region is still limited, and orthohantavirus surveillance is generally restricted in scope to select regions and small portions of host distributional ranges. In Chapter I, I present a literature review on the current understanding of American rodent-borne orthohantavirus ecology. This review focused on under-studied orthohantaviruses, addressing gaps in knowledge by extrapolating information from well-studied orthohantaviruses, general rodent ecology, and occassionally from Eurasian orthohantavirus-host ecology. There were several key conclusions generated from this review that warrant further research: 1) the large number of putative orthohantaviruses and gaps in orthohantavirus evolution necessitate further surveillance and characterization, 2) orthohantavirus traits differ and are more generalizable based on host taxonomy rather than geography, and 3) orthohantavirus host species are disproportionately found in grasslands and disturbed habitats. In Chapter II, I present a prioritized list of rodent species to target for orthohantavirus surveillance based on predictive modeling using machine learning. Probable orthohantavirus hosts were predicted based on traits of known orthohantavirus hosts using two different types of evidence: RT-PCR and virus isolation. Predicted host distributions were also mapped to identify geographic hotspots to spatially guide future surveillance efforts. In Chapter III, I present a framework for understanding and predicting orthohantavirus traits based on reservoir host phylogeny, as opposed to the traditional geographic dichotomy used to group orthohantaviruses. This framework establishes three distinct orthohantavirus groups: murid-borne orthohantaviruses, arvicoline-borne orthohantaviruses, and non-arvicoline cricetid-borne orthohantaviruses, which differ in several key traits, including the human disease they cause, transmission routes, and virus-host fidelity. In Chapter IV, I compare rodent communities and orthohantavirus prevalence among grassland management regimes. Sites that were periodically burned had high rodent diversity and a high proportion of grassland species. However, rodent seroprevalence for orthohantavirus was also highest in burned sites, representing a trade-off in habitat management outcomes. The high seroprevalence in burned sites is likely due to the robust populations supported by the high quality habitat resulting from prescribed burning. In Chapters V and VI, I describe Ozark virus and Sager Creek virus, two novel orthohantaviruses discovered from specimens collected during Chapter IV. Both chapters report full genome sequences of the respective viruses and compare both nucleotide and protein phylogenies with related orthohantaviruses. Additionally in Chapter VI, I support the genetic analyses with molecular and ecological characterizations, including seasonal fluctuations in host abundance, correlates of prevalence, evidence of virus shedding, and information on host cell susceptibility to Sager Creek virus.


Prevalence Of Ehrlichia And Rickettsia Within Ticks In Arkansas State Parks, Haley Stanton May 2023

Prevalence Of Ehrlichia And Rickettsia Within Ticks In Arkansas State Parks, Haley Stanton

Animal Science Undergraduate Honors Theses

Within the past few decades, the number of diagnoses of tick-borne diseases – such as spotted fever rickettsiosis and ehrlichiosis – has steadily increased throughout the United States, with Arkansas having one of the highest rates in the country. These diseases pose a risk to both humans and animals, as both can acquire these infections from ticks. Due to the increasing geographic range of ticks, rise in cases, and likely underdiagnosis of these diseases, this study aimed to identify the infection rate of ticks themselves in multiple state parks in Arkansas. Four Arkansas state parks were each visited once a …


Determining The Effects Of Maternal Adiposity On Preterm Neonatal Microbiome And Short Chain Fatty Acid Profiles, Dalton James, William A. Clark Phd, Kristy L. Thomas May 2023

Determining The Effects Of Maternal Adiposity On Preterm Neonatal Microbiome And Short Chain Fatty Acid Profiles, Dalton James, William A. Clark Phd, Kristy L. Thomas

Undergraduate Honors Theses

The gut microbiota and its metabolites have vast impacts on the human digestive system, immune system, and health outcomes. Short chain volatile fatty acids (SCVFAs) present in feces can be representative of the interactions of the microbiota present in the gut. Low microbiota diversity in the human gut is highly associated with obesity and adverse health outcomes. Furthermore, the maternal microbiome has a direct impact on neonatal microbiota through various pathways such as environment, skin flora, breast milk composition, and vaginal secretions. This study is aimed to further understand the associations between various factors (maternal adiposity, gestational time, length of …