Life Sciences Commons^™

Understanding The Impacts Of Current And Future Environmental Variation On Central African Amphibian Biodiversity, Courtney A. Miller

University of New Orleans Theses and Dissertations

Global climate change is projected to impact multiple levels of biodiversity by imposing strong selection pressures on existing populations, triggering shifts in species distributions, and reorganizing entire communities. The Lower Guineo-Congolian region in central Africa, a reservoir for amphibian diversity, is predicted to be severely affected by future climate change through rising temperatures and greater variability in rainfall. Geospatial modelling can be used to assess how environmental variation shapes patterns of biological variation – from the genomic to the community level – and use these associations to predict patterns of biological change across space and time. The overall goal of …

The Effect Of Styrene-Maleic Acid (Sma) Copolymers On Solubilizing Lipid Bilayers And Forming Nanodiscs, Ghada Alramadan

Dissertations and Theses

Cell membranes, or plasma membranes, play an essential role in the structure and the function of living cells. In 1972, the fluid mosaic membrane model was the first unifying paradigm of membrane structure. It is no longer considered adequate because evidence of many non-homogeneous lipid structures in both natural and model membranes have been discovered over the past thirty years. The field of membrane biophysics now uses updated versions of the mosaic model, which consists of the complex mixture of different lipid species. The lipid species found in natural membranes produce a range of dynamic, laterally segregated, non-homogeneous domains, which …

The Evolution Of Diet Breadth In Melissodes Bees (Apidae: Eucerini), Karen W. Wright

Biology ETDs

The relationship between phytophagous insects and their host plants has interested scientists since Darwinian times. Using modern phylogenetic inference, we are able to investigate these patterns using, not only the phylogenies of the insects, but the evolutionary relationships among the plants they feed on as well. The relationships between bees and the plants they pollinate were traditionally seen as mutualistic and were treated separately from the research investigating the antagonistic relationships between phytophagous insects and their host plants. However, recent phylogenetic studies have made great progress including bee-host relationships in with the larger body of work on phytophagous insects.

The …

The Invisible Brain Injury Crisis, Michael E. Rosenthal

Capstones

According to the Center for Disease Control and Prevention’s 2013 data, over 282,000 hospitalizations and 2.5 million emergency department visits were at least in part attributable to TBI. In the same year, about 56,000 people died.

Emergency departments in 2012 treated about 329,290 kids under 20 for TBI following an injury taking place during physical activity.

This project explores the rise in traumatic brain injuries and examines the difficult path that some of the survivors have to go through during recovery. By telling the story through my own personal experiences, I guide the reader through what the initial trauma and …

Effects Of Ambient Air Pollution On Asthma-Related Emergency Department Visits Within The Las Vegas Metropolitan Area, Loiren E. Monardes

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this research was to evaluate the risk for asthma-related Emergency Department visits and their association with ambient air pollution within the Las Vegas metropolitan area. All data were aggregated by date and ZIP Code. The association was analyzed by applying the distributed lag non-linear model in an attempt to identify elevated concentrations of specific air pollutants

as triggers and their delayed effects (lag days). Relative Risk (RR) and 95% confidence intervals were produced, while adjusting for socioeconomic status. This ecological population-based study analyzed daily asthma counts of Emergency Department visits from January 1st, 2009 to December 31st, …

Singing As A Therapeutic Technique To Improve Gait For People With Parkinson Disease, Elinor Harrison

Arts & Sciences Electronic Theses and Dissertations

Abstract of the Dissertation

Singing as a Therapeutic Technique to

Improve Gait for People with Parkinson Disease

by

Elinor Clare Harrison

Doctor of Philosophy in Movement Science

Neurosciences

Washington University in St. Louis, 2018

Professor Gammon Earhart, Chair

Gait impairment is common in older adults and even more prevalent for people with Parkinson disease (PD). Gait dysfunction is often characterized by reductions in speed, step frequency, and step length. In addition, decreased ability to regulate step length and step frequency may contribute to increased gait variability, making walking less stable and increasing risk for falls. As gait deficits are often …

The Role Of Apolipoprotein E In Regulating Tau Pathogenesis And Neurodegeneration In A Tauopathy Mouse Model, Yang Shi

Arts & Sciences Electronic Theses and Dissertations

APOE4 is the strongest genetic risk factor for late-onset Alzheimer's disease (AD). APOE4 increases brain amyloid-β (Aβ) pathology relative to other APOE isoforms. However, whether APOE independently influences tau pathology, the other pathological hallmark of AD and other tauopathies, or tau-mediated neurodegeneration, is not clear. By generating P301S tau transgenic mice on either a human APOE knock in (KI) or APOE knockout (KO) background, we show that the presence of human APOE, regardless of APOE isoforms, leads to various degrees of brain atrophy in 9-month old P301S mice, whereas APOE ablation strongly protects against neurodegeneration. In particular, P301S/E4 mice develop …

Grammar And Variation: Understanding How Cis-Regulatory Information Is Encoded In Mammalian Genomes, Dana Michele King

Arts & Sciences Electronic Theses and Dissertations

Understanding how genotype leads to phenotype is key to understand both the development and dysfunction of complex organisms. In the context of regulating the gene expression patterns that contribute to cell identity and function, the goal of my thesis research is to how changes in genome sequence may impact impact gene expression by determining how sequence features contribute to regulatory potential. To accomplish this goal, I first leveraged the key regulatory role of pluripotency transcription factors (TFs) in mouse embryonic stem cells (mESCs) and tested synthetically generated and genomic identified combinations of binding site for four TFs, OCT4, SOX2, KLF4, …

The Splice Is Not Right: Splice-Site-Creating Mutations In Cancer Genomes, Reyka Glencora Jayasinghe

Arts & Sciences Electronic Theses and Dissertations

Accurate interpretation of cancer mutations in individual tumors is a prerequisite for precision medicine. Large-scale sequencing studies, such as The Cancer Genome Atlas (TCGA) project, have worked to address the functional consequences of genomic mutations, with the larger goal of determining the underlying mechanisms of cancer initiation and progression. Many studies have focused on characterizing non-synonymous somatic mutations that alter amino acid sequence, as well as splice disrupting mutations at splice donors and acceptors. Current annotation methods typically classify mutations as disruptors of splicing if they fall on the consensus intronic dinucleotide splice donor, GT, the splice acceptor, AG. Splice …

Genetic Basis Of Thermal Divergence In Saccharomyces Species, Xueying C. Li

Arts & Sciences Electronic Theses and Dissertations

The genetic architecture of phenotypic divergence is a central question in evolutionary biology. Genetic architecture is impacted by whether evolution occurs through accumulation of many small-effect or a few large-effect changes, the relative contribution of coding and cis-regulatory changes, and the prevalence of epistatic effects. Our empirical understanding of the genetic basis of evolutionary change remains incomplete, largely because reproductive barriers limit genetic analysis to those phenotypes that distinguish closely related species. In this dissertation, I use hybrid genetic analysis to examine the basis of thermal divergence between two post-zygotically isolated species, Saccharomyces cerevisiae and S. uvarum. S. cerevisiae is …

A Recombinant Virus And Reporter Mouse System To Study Chronic Chikungunya Virus Pathogenesis, Alissa Roxanne Young

Arts & Sciences Electronic Theses and Dissertations

Chikungunya virus (CHIKV) is an arthritogenic alphavirus that during acute disease causes fever as well as severe joint and muscle pain. Chronic joint and muscle pain persists in a significant subset of patients, yet we still have a poor understanding of what drives this chronic disease. While replicating virus has not been detected in the joints of patients with chronic arthritis or in various animal models at chronic time points, persistent viral RNA can be detected for months after acute infection.

To identify the cells that could be contributing to chronic CHIKV pathogenesis, we developed recombinant viruses that express Cre …

Chemically Modified Monolayer Surfaces Influence Valvular Interstitial Cell Attachment And Differentiation For Heart Valve Tissue Engineering, Matthew N. Rush

Nanoscience and Microsystems ETDs

As a cell mediated-process, valvular heart disease (VHD) results in significant morbidity and mortality world-wide. In the US alone, valvular heart disease VHD is estimated to affect 2.5% of the population with a disproportionate impact on an increasing elderly populous. It is well understood that the primary driver for valvular calcification is the differentiation of valvular interstitial cells (VICs) into an osteoblastic-like phenotype. However, the factors leading to the onset of osteoblastic-like VICs (obVICs) and resulting calcification are not fully understood and a more complete characterization of VIC differentiation and phenotypic change is required before treatment of valve disease or …

Comparison Of Cervical Angle During Different Equipment Removal Techniques Used In Ice Hockey For Suspected Cervical Injuries, Kendell Sarah Galor

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of the study was to compare cervical movement between two different methods of removal of the helmet and shoulder pads. Seven college age male subjects (height: 172.54 ± 7.98 cm; weight: 85.70 ± 15.75 kg) with hockey experience volunteered to participate in the study. Each subject agreed to and signed the institutional review board approved informed consent before articipation. Subjects used their own game fit hockey helmet and were fitted with a pair of shoulder pads (CCM Tacks 1052 Sr Shoulder Pads). Cervical spine motion was measured using 3D kinematics (Vicon Motion Systems Ltd., UK). Reflective markers affixed …

Examining Environmental Hazards In Rental Homes And Habitability Laws In Clark County, Nevada, Jorge Luis Bertran

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is well established that home conditions are linked to the health outcomes of occupants. There are over 880,000 housing units in Clark County, Nevada; nearly half of those are renter-occupied units (ROUs). Currently, there is limited research on the characteristics of environmental hazards found in Clark County ROUs and the strength of habitability statutes created to protect tenants from substandard housing. Understanding how renters in Clark County are affected by environmental hazards in ROUs and the processes by which landlords and tenants resolve grievances related to those hazards would benefit public health. It would enhance the ability to quickly …

Mechanistic Characterization Of Resistome And Microbiome Dynamics Across Diverse Microbial Habitats, Andrew John Gasparrini

Arts & Sciences Electronic Theses and Dissertations

Increasing antibiotic resistance in pathogens is a serious public health challenge, with over two million antibiotic resistant infections in the United States leading to at least 23,000 deaths and an estimated $55 billion in excess healthcare and societal costs. Antibiotic resistance has risen steadily in both pathogenic and benign bacteria since antibiotics’ introduction to agriculture and medicine 70 years ago. A dramatic reduction in the number of antibiotics approved for human use has accompanied this rise in antibiotic resistance, leading to the alarming prospect of a post-antibiotic era. Understanding the evolutionary origins, genetic contexts, and molecular mechanisms of antibiotic resistance …

The Role Of Fibrillin-1 In Eye Development And Disease, Wendell Brooks Jones

Arts & Sciences Electronic Theses and Dissertations

The ciliary zonule of the human eye consists of a circumferential array of fibers that connect the ocular lens to the nonpigmented ciliary epithelium (NPCE) located at the inner wall of the eye. Zonular fibers consist of bundles of beaded filaments called microfibrils. Microfibrils are major structural elements of the extracellular matrix and are present in pure form in the ciliary zonule. Microfibrils are composed principally of fibrillin-1 (FBN-1); a large extracellular matrix glycoprotein. In humans, mutations in FBN1 underlie Marfan syndrome; a pleiotropic connective tissue disorder that profoundly affects the eye. Ocular manifestations include ectopia lentis (dislocated lenses), cataracts, …

A Mouse Model Of Börjeson-Forssman-Lehmann Syndrome Reveals A Potential Link With Autism Spectrum Disorder, Cheng Cheng

Arts & Sciences Electronic Theses and Dissertations

ABSTRACT OF THE DISSERTATION

A Mouse Model of Börjeson-Forssman-Lehmann Syndrome reveals a potential link with Autism Spectrum Disorder

By

Cheng Cheng

Doctor of Philosophy in Biology and Biomedical Sciences

Developmental, Regenerative and Stem Cell Biology

Washington University in St. Louis, 2018

Dr. Azad Bonni, Chair

Intellectual disability (ID) is a prevalent neurodevelopmental disorder that affects 1% to 3% of the general population. ID is characterized by developmental deficiencies in cognitive function and adaptive behaviors. Lacking effective treatments, ID currently presents an immense burden to affected families and the economy. Therefore, there is an urgent need to elucidate the pathogenesis of …

The Essential Roles Of The Chromatin Factor Gon4l In Heart Development, Terin Elise Budine

Arts & Sciences Electronic Theses and Dissertations

Heart development and the genetic pathways underlying it are highly conserved among vertebrates. During heart development, an embryo must induce mesoderm formation, pattern the mesoderm, specify cardiomyocytes, increase the population of cardiomyocytes through proliferation, and pattern the cardiac chambers. It is becoming increasingly clear that chromatin modifications help mediate the complex processes of heart development by providing spatiotemporal regulation of gene expression. My thesis work focuses on characterizing functions of the chromatin factor Gonad-4-like (Gon4l), encoded by the gene ugly duckling (udu), in zebrafish heart development. Previous works established a requirement for Gon4l in the formation of many mesoderm derivatives …

Combining Footprinting Mass Spectrometry And Molecular Dynamics Simulation For Structural Studies In Membrane Proteins, Fengbo Zhou

Arts & Sciences Electronic Theses and Dissertations

Membrane proteins are essential in many cellular processes and represent ~60% of all current drug targets. Due to technical limits, membrane proteins of various types were not studied extensively in the past and the biochemistry and functionality of them remain unclear. The structural biology methodologies require pure isolated protein samples for us to resolve their structure and study their biochemical functions. For such in vitro studies, however, membrane proteins often become unstable when isolated from their native lipid bilayer environment. To overcome the challenge, I employed a novel methodology of solubilizing membrane proteins in solution without detergent. I reconstituted ferroportin, …

Protein Structure-Guided Approaches To Identify Functional Mutations In Cancer, Sohini Sengupta

Arts & Sciences Electronic Theses and Dissertations

Distinguishing driver mutations from passenger mutations within tumor cells continues to be a major challenge in cancer genomics. Many computational tools have been developed to address this challenge; however, they rely heavily on primary protein sequence context and frequency/mutation rate. Rare driver mutations not found in many cancer patients may be missed with these traditional approaches. Additionally, the structural context of mutations on tertiary/quaternary protein structures is not taken into account and may play a more prominent role in determining phenotype and function. This dissertation first presents a novel computational tool called HotSpot3D, which identifies regions of protein structures that …

Sequence Analysis Methods For The Design Of Cancer Vaccines That Target Tumor-Specific Mutant Antigens (Neoantigens), Jasreet Hundal

Arts & Sciences Electronic Theses and Dissertations

The human adaptive immune system is programmed to distinguish between self and non-self proteins and if trained to recognize markers unique to a cancer, it may be possible to stimulate the selective destruction of cancer cells. Therapeutic cancer vaccines aim to boost the immune system by selectively increasing the population of T cells specifically targeted to the tumor-unique antigens, thereby initiating cancer cell death.. In the past, this approach has primarily focused on targeted selection of ‘shared’ tumor antigens, found across many patients. The advent of massively parallel sequencing and specialized analytical approaches has enabled more efficient characterization of tumor-specific …

Fast Objective Coupled Planar Illumination Microscopy, Cody Jonathan Greer

Arts & Sciences Electronic Theses and Dissertations

Among optical imaging techniques light sheet fluorescence microscopy stands out as one of the most attractive for capturing high-speed biological dynamics unfolding in three dimensions. The technique is potentially millions of times faster than point-scanning techniques such as two-photon microscopy. This potential is especially poignant for neuroscience applications due to the fact that interactions between neurons transpire over mere milliseconds within tissue volumes spanning hundreds of cubic microns. However current-generation light sheet microscopes are limited by volume scanning rate and/or camera frame rate. We begin by reviewing the optical principles underlying light sheet fluorescence microscopy and the origin of these …

Freezing Of Gait: Mechanisms, Mechanics, And Management, Peter S. Myers

Arts & Sciences Electronic Theses and Dissertations

Parkinson disease (PD) is a neurodegenerative disease with multiple motor and non-motor symptoms, including postural instability, gait impairments, and cognitive deficits. More than 50% of individuals with PD experience a symptom called freezing of gait (FOG), described as a transient inability to take another step forward. Individuals with PD who experience FOG (freezers) have further postural, gait, and cognitive impairments compared to individuals with PD without FOG (non-freezers). While degeneration of the dopaminergic neurons in the substantia nigra is accepted as the primary etiology of the disease, research shows that the disease has a global impact on the brain, accounting …

A Tail Of Two Pancancer Projects: Somatic Variant Identification And Driver Gene Discovery Using Tcga, Matthew Hawkins Bailey

Arts & Sciences Electronic Theses and Dissertations

The implementation of next-generation genomic sequencing has exploded over the past dozen years. Large consortia, such as The Cancer Genome Atlas (TCGA); the International Cancer Genetics Consortium (ICGC); and the Pediatric Cancer Genome Projects (PCGP), made great strides in democratizing big data for the scientific community. These data sets provide a rich resource to build tools for somatic variant discovery and exploratory analysis. Public repositories hold the answer to many novel biological and clinical revelations i.e., the discovery of complex indels, splice creating mutations, alternative super enhancer binding sites, machine learning models to predict mutation impact, and cancer subtype classification …

Neural Mechanisms Of Drosophila Circadian Rhythms, Xitong Liang

Arts & Sciences Electronic Theses and Dissertations

Animals show circadian rhythms in a variety of physiological functions and behaviors. In Drosophila melanogaster, behavioral rhythms are driven by circadian clock genes that are oscillating in ~150 circadian pacemaker neurons. To explain how circadian neurons encode time and regulate different behavioral rhythms, I performed 24-hour in vivo whole-brain calcium imaging using light-sheet microscopy. First, I found that different groups of circadian neurons show circadian rhythms in spontaneous neural activity with diverse phases. The neural activity phases of the M and E pacemaker groups, which are associated with the morning and evening locomotor activities respectively, occur ~4 hours before their …

Establishment Of Turfgrass From Seed And Sod In Sand Based Systems Combining Sprinkler And Subsurface Drip Irrigation Systems, Roshaan Ahmed Khan Niazi

Electronic Theses and Dissertations

The establishment of turfgrass using subsurface drip irrigation (SDI) in sand based media has limited success. However, it is unknown if starting with overhead (sprinkler) irrigation and transitioning to SDI can enhance turfgrass establishment. Two experiments were conducted at Stephen F. Austin State University (SFASU) to investigate the establishment of “L-93” creeping bentgrass (Agrostis stolonifera) from seed and “TifEagle” ultra dwarf hybrid bermudagrass (Cynodon dactylon x Cynodon transvaalensis) from sod using sand based media. Each experiment consisted of two trials conducted in summer 2017 and spring 2018. Both creeping bentgrass trials and the spring ultra dwarf …

Kcnq1/Kcne1 Interaction In The Cardiac Iks Channel And Its Physiological Consequences, Jiajing Xu

McKelvey School of Engineering Theses & Dissertations

Dynamic conformational changes of ion channel proteins during activation gating determine their function as carriers of current. The relationship between these molecular movements and channel function over the physiological timescale of the action potential (AP) has not been fully established due to limitations of existing techniques. We constructed a library of possible cardiac IKs protein conformations and applied a combination of protein segmentation and energy linearization to study this relationship computationally. Simulations reproduced the effects of the beta-subunit (KCNE1) on the alpha-subunit (KCNQ1) dynamics and function, observed in experiments. Mechanistically, KCNE1 increased the probability of “visiting” conducting pore conformations on …

Prokaryotic Diversity And Aqueous Geochemistry Of Subsurface Environments Of The Death Valley Regional Flow System, Joshua David Sackett

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation summarizes over four years of effort towards the completion of a Ph.D. in Biological Sciences. The work presented in this document covers a broad range of topics, but a central unifying theme is prokaryotic life in the continental subsurface. The work presented in each chapter relied heavily on cultivation-independent methods for assessing prokaryotic communities, including prokaryotic community structure reconstruction from high-throughput sequencing of 16S rRNA gene libraries and single-cell genome analysis of novel uncultivated bacteria.

Chapter 2 examines the aqueous geochemistry and prokaryotic diversity of Devils Hole, a cavernous limnocrene and sole natural habitat for the critically endangered …

Cocoa, Postprandial Lipoproteins, And Inflammation In Type 2 Diabetes: A Secondary Data Analysis, Rickelle Tallent

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: Type 2 Diabetes (T2D) is associated with dyslipidemia and chronic low-grade inflammation, which greatly increases the risk of cardiovascular disease (CVD) in this population. Hyperlipidemia and inflammation in the postprandial state substantially contribute to atherosclerosis development and CVD risk, and have shown to be exacerbated by high-fat meals. Dietary cocoa is a rich source of flavanols that is associated with favorable effects on cardiovascular health, such as improvements in the lipid profile and chronic inflammation, in non-diabetic adults.

Objective: To conduct a secondary data analysis using unpublished data from a previously conducted clinical study to determine whether acute cocoa …

Mob-Ndr Kinase Signaling Components Are Required For Epithelial Tube Formation In The Drosophila Follicular Epithelium, Juan Carlos Duhart

UNLV Theses, Dissertations, Professional Papers, and Capstones

A major goal of developmental biology is to understand how a single fertilized cell can give rise to the many functional tissues and organs, of specific sizes and shapes, that make up the adult body plan. Over the last 25 years, developmental geneticists have uncovered much concerning the cell-to-cell communication systems that are necessary to build complex tissues and organs. For example, throughout development, cells communicate with their neighbors using specialized signaling molecules. These signals are instructive and provide “signal-receiving” cells with information about space and time. That is, signal-receiving cells “learn” precisely where they are located, and, how far …