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Bayesian Variable Selection Methods For Genome-Wide Association Studies With Categorical Phenotypes, Benazir Rowe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Genome-wide association studies (GWAS) attempt to find the associations between genetic markers and studied traits (phenotypes). The problem of GWAS is complex and various methods have been developed to approach it. One of such methods is Bayesian variable selection (BVS). We describe the BVS methods in detail and demonstrate the ability of BVS method Posterior Inference via Model Averaging and Subset Selection (piMASS) to improve the power of detecting phenotype-associated genetic loci, potentially leading to new discoveries from existing data without increasing the sample size.

We present several ways to improve and extend the applicability of piMASS for GWAS. The …

The Effect Of Body Armor On Pulmonary Function And Repeated Sprint Performance, Dustin Dunnick

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Tactical athletes face the unique task of performing physically demanding occupational duties often while wearing torso-borne loads. While pulmonary function has been shown to decrease while wearing plate-carrier style body armor, there has yet to be a study using the more accurate measurement of plethysmography to determine exactly why. Additionally, the inspiratory muscle’s pressure generation capabilities and how they respond to a repeated running sprint test while wearing body armor are unknown. Therefore, the purpose of this dissertation was to examine how body armor affects pulmonary function, inspiratory muscle strength, and athletic performance during repeated, high-intensity sprints.

Methods: Twelve …

Light Conditions During Desiccation And Rehydration Impact The Recovery Of Cultured Timmiella Crassinervis, Sotodeh Ebrahimi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many terrestrial mosses of xeric environments experience excess light during extended periods of desiccation. While dry or hydrated, excess light energy can lead to formation of reactive oxygen species and photoinhibition (e.g. damage to Photosystem II) which affects photosynthetic stress and efficiency. This study aimed to determine the effect of duration dry and light intensity (PAR) on cultured shoots of the chaparral moss Timmiella crassinervis, as well as to elucidate the optimal rehydration light conditions for this species. I hypothesized that 1) mosses exposed to higher light intensities during desiccation would incur more damage upon rehydration than those exposed to …

Tissue-Specific Responses From A Global Developmental Signal: A Detailed Subcellular Analysis Of The 20e And Rab Signaling Pathways Controlling Exocrine Secretion During Drosophila Development, Nichalas Nelson

UNLV Theses, Dissertations, Professional Papers, and Capstones

During metamorphosis, the steroid hormone 20-hydroxecydysone (20E) triggers a plethora of tissue-specific responses in the common fruit fly, Drosophila melanogaster. The salivary glands are exocrine organs that respond to a large pulse of 20E to secrete a massive cargo of stored glycoproteins called glue. Because the glands are amenable to ex vivo-organ culture and powerful genetic manipulations, they are an excellent model for studying the conserved developmental and physiological signaling pathways that regulate the general function of these specialized secretory tissues. Our lab has generated transgenic animals in which the secreted glue molecules are tagged with fluorescent proteins. I have …

Association Between White Matter Hyperintensities, Cortical Thinning, And Clinical Outcomes In Mild Traumatic Brain Injury, Thomas Helmut Knoblauch

UNLV Theses, Dissertations, Professional Papers, and Capstones

Traumatic Brain Injury (TBI) is a global health challenge, with over 4.6 million confirmed cases annually in North America alone. Mild traumatic brain injuries (mTBIs) are the most common and make up approximately 81% of all TBI diagnoses worldwide [1]. Studies indicate that 10–15% of patients suffer from trauma induced symptoms (i.e. headache, loss of balance, cognitive impairments, fatigue, and mental health/affective disorders) as far as 1 year post injury [2]. Prediction and management of these post-traumatic sequalae is complicated by a lack of symptom associated neuroimaging findings. In spite of a “prominent distribution” of frontotemporal WMHs in pediatric subjects …

Effects Of Wildfire On Plant And Insect Pollinator Communities In The Mojave Desert, Nha Trang Vivian Sam

UNLV Theses, Dissertations, Professional Papers, and Capstones

The changing fire regime of landscapes across the Mojave Desert has prompted considerable research on its effects on plant community recovery, but it has not been widely studied what effects wildfire may have on native pollinators and the vital ecosystem services they provide. Ecological changes from increased wildfire severity from invasive exotic annual grasses will likely continue influencing pollinator habitats and floral resources. Understanding the effects that wildfires have on pollinators is valuable to make decisions as to whether active management and restoration activities are required to conserve ecologically vital pollinator functions. The intention of this thesis was to examine …

Microbe-Mineral Interactions During Exceptional Fossil Preservation, Stromatolite Formation, And Desert Varnish Growth, Michael Strange

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Ediacaran to Cambrian Deep Spring Formation consists of mixed carbonate-siliciclastic strata which contain an increasingly complex and biogeographically important biota. Past investigations of the Deep Spring Formation at Mt. Dunfee, Nevada, explored the highly diverse microbialite reefs consisting of a wide range of stromatolite morphologies which exerted significant control on local sedimentation and topography. Early investigations also documented the biomineralizing metazoan Cloudina (an Ediacaran index fossil). However, recent exploration of the area has resulted in the discovery of several new metazoan fossil communities consisting of a diverse assemblage of Ediacaran soft-tissue tubicolous vermiforms (tube fossils) similar to Cloudina. The …

The Influence Of Cerebellar Transcranial Direct Current Stimulation On Motor Function In Parkinson’S Disease, Lidio Lima De Albuquerque

UNLV Theses, Dissertations, Professional Papers, and Capstones

Parkinson's disease (PD) is the most common movement disorder and the second most common neurodegenerative disorder. PD is characterized by dopaminergic cell loss in the substantia nigra pars compacta, which leads to a reduction in dopamine in the striatum. These physiological mechanisms lead to a number of motor impairments such as bradykinesia, rigidity, tremor, and postural instability that severely limit the ability of individuals with PD to perform many essential daily living activities. Although current pharmacological, surgical, and physical exercise treatment approaches are valuable they are either only mildly effective, expensive, or associated with a variety of side effects. Therefore, …

Does Wearing Multiple Pairs Of Shoes Influence Injury Rates?, Julien Mihy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Running research has attempted to better understand the causes of movement-related injuries and a large segment of this research revolves around footwear and training regimens. A survey has reported lower injury rates in runners who wore multiple shoes with in a 5-month period. Previous literature lacks the analysis of variables leading to training related decisions and whether wearing multiple pairs of shoes can have an extended influence on injury rates. PURPOSE: To determine whether wearing multiple pairs of shoes has an influence on injury rates. METHODS: A survey was developed to ask participant’s injury related history along with their footwear, …

An Investigation Into Multi-View Error Correcting Output Code Classifiers Applied To Organ Tissue Classification, Daniel Alvarez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Large amounts of data is being generated constantly each day, so much data that it is difficult to find patterns in order to predict outcomes and make decisions for both humans and machines alike. It would be useful if this data could be simplified using machine learning techniques. For example, biological cell identity is dependent on many factors tied to genetic processes. Such factors include proteins, gene transcription, and gene methylation. Each of these factors are highly complex mechanism with immense amounts of data. Simplifying these can then be helpful in finding patterns in them. Error-Correcting Output Codes (ECOC) does …

Transposable Element Expression In Human Embryo Single-Cell Rna-Seq Data, Corinne Sexton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Transposable elements (TEs) are genetic sequences which are mobile within the genome, including DNA transposons and retrotransposons. Though the vast majority are no longer able to move or duplicate in humans, they still are actively transcribed in both germline and somatic cells, particularly in early human development. TEs are expressed in an extremely cell-type and stage specific pattern during embryogenesis, suggesting that they may either have a regulatory role in the cell or be transcribed along with cell-specific genes. However, earlier studies have focused on hESC models or early embryos up to day 6, with differing patterns of TE expression. …

Transcriptional Control Of Virulence Genes In The Bacterial Pathogen Shigella Flexneri, Joy Asami Mckenna

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shigella species, the causal agents of bacillary dysentery, use a type III secretion system (T3SS) to inject two waves of virulence proteins, known as effectors, into the human colonic epithelium to subvert host cell machinery. Transcriptional regulation of these virulence genes is controlled by the three-tiered VirF/VirB/MxiE signaling cascade. Of these, VirB has the largest regulon (~50 genes); however, VirB regulatory properties are poorly understood. To date, VirB is known to function to counter or 'anti-silence' transcriptional silencing mediated by the histone-like nucleoid structuring protein H-NS. To better understand VirB regulation, my colleagues and I chose to better define the …

The Influence Of Motivational And Attentional Focus Factors On Throwing Accuracy In Elite Softball Athletes, Jacquelyn Sertic

UNLV Theses, Dissertations, Professional Papers, and Capstones

According to the OPTIMAL theory of motor learning (Wulf & Lewthwaite, 2016), autonomy support (AS), enhanced expectancies (EE), and external focus (EF) of attention are key to effective motor performance and learning. AS allows individuals to exercise control, EE

provides performers with an increased sense of confidence, and EF directs attention to the intended movement effects. Previous research indicates that these factors individually and collectively can improve motor performance and learning in novices and experienced performers. Few studies have used elite performers as participants. Purpose: To determine whether skilled throwing performance can be enhanced by a successive implementation of AS, …

The Relationship Between Tree Canopy And Social Capital On Physical Activity In Unlv Students, Melissa Bartshe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Despite the numerous health benefits, rates of physical activity are low, especially among the college student population. Neighborhood tree canopy is one aspect of the built environment that has been shown to positively impact physical activity. Social capital has also been correlated with higher rates of physical activity. The sprawling urban design and arid desert climate of Las Vegas pose unique challenges to both tree canopy and social capital. Additionally, the relationship between tree canopy, social capital, and physical activity is understudied in the college student population. The purpose of this study was to assess the relationship of tree canopy …

Utilizing Breathing Techniques To Maximize Training Performance, Peyton Cater

UNLV Theses, Dissertations, Professional Papers, and Capstones

Anaerobic exercise causes metabolic acidosis to occur in the muscle, which is unfavorable for sustaining high intensity activity, as fatigue starts to set in. In order to compensate for the onset of fatigue produced by an acidic environment, respiratory alkalosis, induced by hyperventilation, can be performed to mitigate these effects. In contrast, research has shown that slowing down the breath rate, such as a two second inhale and three second exhale, has led to an increase in performance outcomes. Purpose: To investigate power output and the physiological responses after implementation of different breathing techniques during the recovery periods of intermittent …

Do Compression Garments Work? The Effect Of Compression Garments On Biomechanical And Physiological Factors, Andrew Craig-Jones

UNLV Theses, Dissertations, Professional Papers, and Capstones

New and innovative technology is consistently being introduced to help runners gain an edge over their competition. One of the more popular ergogenic aids in running today is compression garments. It is estimated that the compression garment market will surpass $5 billion by the year 2022. Despite the popularity, there is no clear consensus as to if or why compression is effective as an ergogenic aid. Although there has been a large variety of variables tested, there is little agreement on any of them as to the effect compression has. It appears as if the rate at which compression is …

Synthesis And Characterization Of Synthetic Urban Melt Glass, Rebecca Kristien Lowe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Melt glass formed from the explosion of a nuclear device is a unique post-detonation material that can aid in the ensuing forensics investigation. Trapped in the melt glass are chemical and isotopic signatures that can provide diagnostic and source information about the weapon by comparison with documentation of previous detonations. A nuclear terrorist attack would likely take place in an urban environment and as such, the melt glass formed would consist of a complex matrix including urban materials like cement and glass, activation products from the large neutron flux that will be seen, and fission products from the detonation. The …

Rapid Evolution Of Starvation Resistance In Drosophila: Physiological And Molecular Mechanisms, Austin Joseph Mckenna

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Gibbs lab has maintained starvation-selected Drosophila melanogaster for >130 generations. These starvation-selected flies evolved an obese phenotype with a suite of physiological differences compared to control-fed flies. Previous studies have shown that long-term starvation-selected Drosophila contain more lipids, have lower metabolic rates and develop more slowly than controls. This dissertation encompasses 1) Examining the molecular mechanisms contributing to starvation resistance, 2) Functional validation of the candidate plin1 allele, and 3) Rapid physiological and genomic evolution in starvation-selected Drosophila.

Starvation-selected Drosophila survive starvation conditions much longer than control-fed flies. This study took a simple approach to identify possible differences in …

Investigation Of Acute Response To Carbohydrate In Subsequent Resistance Training, Damon Mccune

UNLV Theses, Dissertations, Professional Papers, and Capstones

Resistance training has been shown to have several positive benefits to health including increasing muscle size and strength, reducing risk of sarcopenia with aging, and is associated with reduced risk of mortality. A cornerstone in accomplishing these goals is to progressively overload the muscle by increasing training volume to promote muscle protein synthesis following training stimulation. Total training volume has been demonstrated in the literature to be a prime determinant of muscle hypertrophy and overall training performance. Carbohydrate (CHO) manipulation has been observed as a potential ergogenic aid when training demands are high. Current research investigating nutrition related to exercise …

Oral Localization Of Scardovia Wiggsiae, Graydon Ramos Carr

UNLV Theses, Dissertations, Professional Papers, and Capstones

Early childhood caries is one of the most prevalent diseases in the United States among children. The formation of caries is a complex, multifactorial process that is still being studied. Researchers have thought for years that Streptococcus mutans was the primary causative agent of early childhood caries. The recent discovery of a novel cariogenic pathogen, Scardovia wiggsiae and its significant contribution to the etiology of early childhood caries has led oral health researchers to re-evaluate this microorganism and its link to this disease. While there have been several projects undertaken within the University of Nevada, Las Vegas School of Dental …

Partitioning The Mechanical Cost Of Human Walking: Unveiling Cost Asymmetries For Bionic Technologies, Michael Richard Isaacs

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biomechanics studies over the past 150 years, suggest that animals, including humans, move at speeds that “optimize” their cost of transport. These optimizations can be metabolic, mechanical, or a mixture of the two; however, the consensus on the relationship between metabolic and mechanical cost has been muddied by our current conceptualizations of mechanical cost. Our prior considerations in assessing mechanical cost of transport for animal locomotion often rely upon the exchange of potential and kinetic energy for a rising and falling center of mass that is supported by rigid legs. As a result, our understanding of the mechanical costs associated …

The Significance Of Mfd And Oxidative Damage In Stationary-Phase Mutagenesis In Bacillus Subtilis, Holly Anne Martin

UNLV Theses, Dissertations, Professional Papers, and Capstones

The process of stationary-phase mutagenesis, also known as adaptative or stress-induced mutagenesis, is a phenomenon where bacterial cells accumulate mutations in non-replicative conditions. This process has mainly been studied in Escherichia coli and Bacillus subtilis; however, the underlying mechanisms found in each of these systems differ. Here, I use B.msubtilis to study previously understudied aspects of stationary-phase mutagenesis. In this dissertation, I describe work that has led to three major discoveries which are described below.

First in B. subtilis, Mfd is important for stationary-phase mutagenesis and its mutagenic function at regions of the genome that are transcriptionally upregulated has been …

Can Desert Mosses Hide From Climate Change? The Ecophysiological Importance Of Habitat Buffering & Water Relations To A Keystone Biocrust Moss In The Mojave Desert, Theresa Ann Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

Empirical and observational studies suggest a keystone biocrust moss, Syntrichia caninervis, may be sensitive to future climate change in the American Southwest due to its uniquely sensitive water relations that appear particularly challenged during summer hydration-desiccation cycles. However, the potential mitigating roles of habitat buffering, acclimatization, and winter recovery on the vulnerability of this species remain largely unexplored. I investigated potential abiotic and biotic resiliency factors driving summer stress resistance and recovery in S. caninervis along present-day aridity gradients in the Mojave Desert to strengthen the climate change vulnerability assessment for this species common to biocrusts of North America, northern …

Investigating The Mechanisms Responsible For Cephalosporin Resistance In Clostridioides Difficile Strain 630, Lara Anna Turello

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clostridioides difficile infection (CDI) is one of the most common nosocomial infections worldwide. A major risk factor for CDI is antibiotic therapy, due to C. difficile’s resistance to a myriad of antibiotics—one of which are cephalosporins. Cephalosporins are ß-lactam antibiotics that function by binding to the active site of penicillin-binding proteins (PBPs), thus inhibiting peptidoglycan synthesis and leading to cell lysis. Gram-positive bacteria can counteract ß-lactams by (i) producing ß-lactamases, (ii) expressing modified PBPs, or (iii) by expressing efflux pumps.

Genomic analysis of C. difficile strain 630 revealed the presence of at least 31 putative ß-lactam resistance genes that encode …

Paleoecology Of Columbian And Pygmy Mammoths In Southern Nevada And California: How Terminal Pleistocene Ecosystems Shaped Mammoths At The Individual, Population, And Community Level, Lauren Elizabeth Parry

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this dissertation research is to examine the paleoecology of the Columbian mammoth (Mammuthus columbi) and the pygmy mammoth (M. exilis) on the individual, population, and community level, emphasizing factors internal to their ecosystem that may have contributed to their extinction. I focus specifically on mammoths from Southern Nevada and Southern California to add regional data to the complex and evolving study of North American mammoth paleoecology.

Chapter 2 documents the permitted excavation of a partial mammoth (Mammuthus sp.) between 2016-2018 from late Pleistocene groundwater-discharge deposits near Fairbanks Spring in the Amargosa Valley, Nevada. A preliminary radiocarbon date …

The Influence Of G4 Dna Structures On Stationary Phase Mutagenesis In Bacillus Subtilis, Tatiana Ermi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Until the late 1980’s it was widely understood that bacterial variance emerges randomly during growth. Research that followed has convincingly shown evidence for mutations arising in non-growing conditions, a phenomenon known as stationary-phase mutagenesis. In Bacillus subtilis, an elegant mutagenic mechanism has been elucidated in non-growing cells that biases mutations to transcribed regions of a subpopulation. One interesting possibility is that mutations can be further biased to hotspots within genes through alternate DNA structures known as non-B DNA. Non-B DNA have been linked to genomic instability and disease in humans, lesser is known about its role in bacteria. Here we …

Rapid Detection Of Toxin-Producing Cyanobacteria, Timothy Alba

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lake Mead provides drinking water to millions of people in Nevada, California, and Arizona. In 2015, the Southern Nevada Water Authority detected the cyanobacteria-produced toxin microcystin in the lake for the very first time. This toxin is lethal in large doses, and in small doses it causes a myriad of serious health effects. Detecting microcystin directly is a time-consuming and expensive process that requires liquid chromatography tandem mass spectrometry or immunological analyses, which require a full day or more to process samples. In order to provide water managers with the methodology for a toxin monitoring plan, this work developed a …

Characterization Of Beryllium Ion Complexation In The Presence Of Biological Buffers Using Isothermal Titration Calorimetry, Guillermo Alexander Ramirez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Be2+ ion is a biologically active metal that is capable of binding to proteins and has been shown to affect various cellular processes. When treated with Be2+, certain cancer cells display cytostatic effects. GSK3β is a regulatory kinase involved in the β-catenin pathway that may be involved in producing these cytostatic effects when Be2+ binds to it. In order to determine binding parameters between Be2+ and GSK3β, isothermal titration calorimetry (ITC) can be utilized. However, titrations at physiological pH cannot be carried out due to Be2+ unique speciation at neutral pH ranges. Significant precipitation occurs at pH 6 and higher …

Respiratory And Perceptual Responses To High Intensity Interval Exercise In Obese Adults, Nicholas Andrew Ross

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: Obese adults experience low lung volume breathing at rest and during exercise, which provokes ventilatory constraints and dyspnea on exertion. High-intensity interval exercise (HIIE) has emerged as an alternative to continuous exercise (CE); however, the effects of HIIE on lung volumes, ventilatory constraints and dyspnea on exertion have not been studied in obese adults and thus tolerability of HIIE remains unknown. Therefore, the purpose of this study was to examine the differences in respiratory and perceptual responses during HIIE versus CE in obese adults when compared with nonobese adults. Methodology: Ten healthy, nonobese (24.1 ± 6.2 yr., BMI: 23 …

Stereotactic Radiosurgery Implementation At Utah Valley Hospital, Ryan Sharp

UNLV Theses, Dissertations, Professional Papers, and Capstones

Utah Valley Hospital (UVH) implemented a stereotactic radiosurgery (SRS) program as an additional line of service. SRS as defined by the American College of Radiology is radiation therapy delivered via stereotactic guidance with approximately 1 mm targeting accuracy to intracranial targets in 1-5 fractions. Effectively implementing the SRS program at UVH requires the adoption and implementation of hardware and software technologies, a review of the clinical workflow with appropriate quality assurance tests, and the assessment of additional technologies that will further enhance the capabilities of the program. The scope of this work is to include a comprehensive writeup of the …