Life Sciences Commons^™

Axon Initial Segment Morphology Across Typical Cortical Development And In Mouse Models Of Neurodevelopmental Disorders With A High Incidence Of Epilepsy, Rachel Ali Rodriguez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neurodevelopmental disorders (NDDs) are commonly associated with a high incidence of epileptic seizures which result from excessive firing of neurons. The axon initial segment (AIS) is a neuronal compartment essential for the control of activity patterns of neurons. The AIS undergoes important modifications during development, but the molecular mechanisms that affect the development, morphology, and protein composition of the AIS are still not well understood. We examined AIS morphology of medial prefrontal cortex (mPFC) pyramidal neurons in wildtype mice across development and in two mouse models of NDDs. Results indicate restructurings at the AIS during typical development, some of which …

Machine Learning Analysis Of Single Nucleotide Polymorphism (Snp) Data To Predict Bone Mineral Density In African American Women, Erick Githua Wakayu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Osteoporosis is a debilitating disease in which an individual’s bones weaken, making bones fragile and more susceptible to fracture. While commonly found amongst postmenopausal Caucasian and Asian women based on previous studies, those of African descent (African American/Black) have largely been ignored when it comes to osteoporotic studies, especially when it comes to Genome Wide Association Studies (GWAS). From GWA studies, we gain access to single nucleotide poly-morphisms (SNPs) that may contribute to certain illnesses, such as osteoporosis. With low Bone Mineral Density (BMD) being one of the primary markers of potential osteoporosis, it is prudent that proper research is …

Designs And Outcomes Of Transcranial Magnetic Stimulation (Tms) And Repetitive Transcranial Magnetic Stimulation (Rtms) Circuits, Daniel Senda

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis reports the design and outcomes of several circuits intended for transcranial magnetic stimulation (TMS) and repetitive transcranial magnetic stimulation (rTMS) research. In simple terms, TMS circuits are composed of four main blocks: high voltage power source, energy storage bank, control switch, and coil. Each one of these blocks has characteristics that influence how well the circuit will perform for TMS procedures. A successful TMS research circuit must have the ability to emit controlled electromagnetic pulses through a coil connected to it. For the first block, voltages ranging from 50 V to 2 kV were used. In the second …

Physiological And Mechanical Comparisons Between Clipless And Flat Pedals, Katelyn Conroy

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to investigate the physiological and mechanical comparisons between clipless and flat pedals. Participants (n=4) completed two at-home 20-minute FTP tests: using clipless and flat pedals using Zwift. The order of conditions were randomized for each participant. Participants used their personal Smart Trainers, clipless pedals, and cycling shoes while flat pedals were provided (Syun-LP, Road Bike Platform Pedals). Power, heart rate and cadence were recorded and used for analysis. All dependent variables were compared using paired t-tests. Power was significantly greater for clipless (226.7 ± 46.2 W) vs. flat (215.2 ± 41.8 W) pedals (p …

Multiple Approaches To Auditory Rhythm: Development Of Sustained Musical Beat And The Relation To Language, Development Of Rhythmic Categories Via Iterated Production, And A Meta-Analytic Study Of Neural Entrainment To Beat, Karli Marie Nave

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rhythm is ubiquitous to human communication, coordination, and experience of music. In this dissertation, I address three empirical questions through three different methodologies, all of which contribute to the growing body of literature on human auditory rhythm processing. In Chapter 2, I present a registered report detailing the results of independent conceptual replications of Nozaradan, Peretz, Missal, & Mouraux (2011), all using the same vetted protocol. Listeners performed the same tasks as in Nozaradan et al. (2011), with the addition of behavioral measures of perception. In neuroscience, neural correlates to musical beat perception have been identified, yet little to no …

Effects Of Bimodal Transcranial Direct Current Stimulation On Modulation Of Spinal Circuitry In People With Chronic Post-Stroke Hemiparesis, John Patrick Gan, Rafael Cabrera, Lana Laudermilch, Benjamin Wolkenhauer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: Stroke can lead to gait abnormalities such as foot drop. Foot drop can result from decreased corticospinal tract input to the ankle dorsiflexors and/or from exaggerated stretch reflexes on the soleus due to reduced reciprocal inhibition from spinal reflex pathways. Transcranial direct current stimulation (tDCS) attempts to modulate corticospinal tract input and spinal reflex pathways by delivering electrical signals to parts of the brain. The degree of neuromodulation from tDCS can be measured through the Hoffman Reflex (H-reflex)—a tool used to estimate alpha motor neuron excitability which is increased in individuals post-stroke. Purpose: The primary purpose of this study …

Description, Reliability And Validation Of A Novel Ground-Reaction-Force-Triggered Protocol For Simulation Of Tripping Perturbations During Gait, James Anderson, Samuel Hadley, Denise Ng, Catrina Fabian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Tripping is a common cause of falls across different age populations particularly in older adults. Concerns regarding the validity of simulated-fall research protocols reside in the current literature. The purpose of this study was to develop a novel treadmill-based tripping protocol that allowed researchers to deliver unanticipated tripping perturbations during walking with a high level of timing precision. The protocol utilized a side-by-side split-belt treadmill instrumented with force platforms. Treadmill belt acceleration profiles (two levels of perturbation severity: small perturbation vs large perturbation) were delivered unilaterally when the tripped leg bore 20% of the body weight during early stance. Peak …

Investigation Of Algorithms To Assess Validity Of Wearable Technology During Field Testing, Brenna Barrios

UNLV Theses, Dissertations, Professional Papers, and Capstones

Wearable technology is an emerging fitness trend where the technology which supports it lacks validity verification. Furthermore, heart rate validity of these devices vary greatly when observed in laboratory settings vs. field testing. Secondarily, Consumer Technology Association guidelines require a minimum five minute trial for wearable testing. This study examined heart rate data of previously tested wearable devices (Garmin Fenix 5, Jabra Elite Sport, Motiv Ring, Scosche Rhythm+) in an outdoor setting to further understand their performance, and to examine the relationship of the five minute regulation. Two separate algorithms were applied to the original data set, the first shortened …

Comparing The Incidence And Prevalence Of Oral Microbial Pathogens Selenomonas Noxia And Streptococcus Mitis Within The Unlv-Sdm Clinical Patient Population, Namgu Kim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Selenomonas noxia (SN) is a gram-negative, anaerobic bacteria, which contributes to development and progression of periodontal disease. Some evidence now suggests Streptococcus mitis (SM), a gram-positive, facultative bacterium contributing to the etiology of dental caries and periodontal disease, may also influence the prevalence of SN within subgingival complexes. Based upon the overall lack of prevalence data, the objective of this study was to evaluate presence of SN and SM using qPCR among saliva samples taken from pediatric, adult, and orthodontic dental school clinics.

Methods: This study involved a retrospective analysis of previously collected saliva samples from an existing biologic …

Relationship Between Jump Performance And Asymmetry, Cordero Roche

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this dissertation is to investigate the relationship between jump performance and asymmetry. This investigation was divided into three separate studies. The first aim investigated which asymmetry variables for eccentric and concentric phases best predicted jump height (JH) during different jump types. The aim of the second study was to determine if asymmetry variables differed between jump type and genders.

Fourteen participants performed countermovement jumps (CMJ) and drop vertical jumps (DVJ). The DVJ were administered from a 30.5 cm platform leading with dominant leg striking separate force platforms with each foot. Vertical ground reaction forces were used to …

The Effects Of Green Exercise On Perception And Connectedness To Nature, Robert W. Salatto

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The purpose of this dissertation is three-fold: 1. Investigate the effects of acute beta alanine ingestion during green exercise on connectedness to nature, and perception of pain. 2. Investigate the test-retest reliability of the Love and care of Nature Scale during the task of mountain biking. 3. Investigate the effects of green exercise on connectedness to nature and perception. Methods: Three individual studies were conducted: The first was a double-blinded, placebo-controlled, crossover study design which examined the effect of induced painful sensation (via acute Beta Alanine (B-ALA) ingestion) on Love and Care of Nature (LCN), heart rate (HR), rating …

Opioid And Naloxone Training In A Rural School District, Allyson C. Waldron

UNLV Theses, Dissertations, Professional Papers, and Capstones

The opioid epidemic is a national health emergency in the United States, with over 128 people dying each day due to an opioid overdose. It is estimated that 4.3 million people over the age of 12 use opioids without a medical need, and 1.3 million youth ages 12-17 use opioids inappropriately. Drug overdose deaths have become the leading cause of accidental death in the United States, prompting the U.S. Surgeon General and the World Health Organization to advise that more Americans have access to naloxone and understand how to use this life-saving drug correctly. Naloxone is an opioid antagonist, used …

Distributions And Habitat Associations Of Blue Point Pyrgulopsis And Blue Point Tryonia, Chenoa Janine Wilcox

UNLV Theses, Dissertations, Professional Papers, and Capstones

Springsnails and other crenophilic species are often of conservation concern due to endemism, narrow habitat requirements, and susceptibility to habitat degradation. Because there is a distinct lack of natural history information for many of these organisms, management of species that are of concern is often based on data from non-target species related to the species of interest. In this thesis, I provide background information regarding springsnails in western North America (Chapter 1), describe a study investigating the distribution and habitat associations of two springsnails endemic to a single spring (Chapter 2), and provide supplemental information on habitat characteristics associated with …

Relationship Of Shoe Wetness To Mechanical Performance, Sara Lyn Crawford

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to mechanically impact test shoes that underwent both saturation and repetitive loading protocols to determine if these interventions affected the impact absorption and energy return properties of a shoe. Six pairs of the same make and model of shoe were divided into Control and Experimental Groups and tested on an impact machine before and after undergoing a protocol. The repetitive load protocol involved subjecting the shoes to impacts commensurate with a 5 km race. The water saturation protocol involved soaking the shoes until reaching their maximum saturation. The Control shoes underwent initial testing and …

The Role Of Nutrition And Hormone Signaling In Extended Larval Development And Obesity In Starvation-Selected Drosophila Melanogaster, Jennifer M. Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

Brief periods of starvation are a common stressor that most animals encounter in the wild and must be able to survive in order to maximize their fitness. Starvation resistance of the adult fruit fly, Drosophila melanogaster, is thought to be primarily conferred by adult fat stores, body size, metabolic rate, behavior, and activity levels. Additionally, flies selected for starvation resistance also often show delayed pupariation, which is usually indicative of altered hormone signaling. How starvation selection extends development and if it contributes to adult starvation resistance remains incompletely studied. Identifying the targets of starvation selection that cause extended development and …

Food Insecurity And Risky Sexual Behaviors Among College Students, Bertille Octavie Mavegam Tango Assoumou M

UNLV Theses, Dissertations, Professional Papers, and Capstones

Food insecurity and sexually transmitted infections (STIs) are growing public health problems in the United States. Young people in general, and particularly college students, exhibit high prevalence of food insecurity, STIs, and risky sexual behaviors (RSB). Food insecurity and STIs among college students can have short- and long-term impacts on their academic success and their lives. Several studies have reported an association between food insecurity and some risky sexual behaviors among specific populations including HIV-infected people and homeless people. However, little is known about the relationship between food insecurity and RSB among college students. Given the high prevalence of food …

Patient-Specific Finite Element Analysis For Mandibular Fracture Fixation, Ethan Snyder

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis proposes an approach for Finite Element Analysis (FEA) of mandibular fracture fixation. Using a Computerized Tomography (CT) scan of mandible obtained from a specific person, the material characteristics, density and modulus of elasticity, were determined from a set of discrete points within the mandible that are 1mm spaced based on the Hounsfield Units of these points. The mandible geometry was sectioned to simulate a fracture. Muscle and mastication forces were added to replicate post-surgery loading. Using a standard linear miniplate, this material model was compared with two commonly used mandibular cortical shell bone models: isotropic and orthotropic. A …

The Influence Of Sports-Related Concussion On Lower Extremity Injury Risk In Adolescent And Collegiate Athletes, Jason M. Avedesian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sports-related concussion (SRC) represents a major epidemiological concern in the adolescent and collegiate athlete populations, with conservative estimates of approximately four million SRCs occurring each year in the United States. While the majority of previous research has emphasized the management and recovery of the cognitive aspects of SRC, recent data indicates subtle motor behavior is altered following a concussive event. Injury surveillance literature indicates that adolescent and collegiate athletes are at an approximately 2–4 greater risk for lower extremity (LE) injury following an SRC when compared to matched controls and pre-SRC LE injury rates. Furthermore, athletes with a previous SRC …

Implications Of The Evolutionary Past On The Activities Of Virb: A Key Transcriptional Regulator Of Virulence Genes In Shigella Flexneri, Jillian Nicole Socea

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shigella species are bacterial agents that are the leading cause of diarrheal diseases, the second leading cause of child mortality worldwide. One key protein in Shigella is VirB, a transcriptional regulator of virulence genes that is essential for pathogenicity. VirB functions to antagonize H-NS, a histone-like nucleoid structuring protein that silences many genes found on the large virulence plasmid (pINV). The interplay between H-NS, the silencer, and VirB, the anti-silencer, is fundamental for Shigella virulence. Furthermore, this mechanism of gene regulation appears widespread in many bacteria including other enteric pathogens.

The goal of my dissertation was to explore the activities …

Assessing The Validity And Reliability Of Several Heart Rate Monitors In Wearable Technology While Mountain Biking, Bryson Carrier

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study sought to assess the validity and reliability of several heart rate (HR) monitors during mountain biking (MTB), compared to the Polar H7® HR monitor, used as the criterion device. Methods: A total of 20 participants completed two MTB trials wearing 6 HR monitors (1 criterion, 5 test devices). HR was recorded on a second-by-second basis for all devices analyzed. After data processing, validity measures were calculated, including 1. Error analysis: mean absolute percentage errors (MAPE), mean absolute error (MAE), and mean error (ME), and 2. Correlation analysis: Lin’s concordance correlation coefficient (CCC) and Pearson’s correlation coefficient ®. Validity …

The Influence Of Resistance Training On Post Surgical Outcomes In Individuals With Anterior Cruciate Ligament Injury, Kevin H. Choe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The anterior cruciate ligament (ACL) is commonly injured, especially in individuals under the age of 25. ACL reconstruction (ACLR) is the most common treatment after ACL injury, followed by physical therapy. However, successful surgery and completion of rehabilitation, individuals still demonstrate quadriceps weakness and asymmetries during locomotion. To improve these deficits, an intervention that improves quadriceps strength and lower extremity biomechanics during locomotion is required. First, we aimed to complete a systematic review of the literature to determine the efficacy of resistance training in improving outcomes after ACLR. Second, we aimed to identify if a history of resistance training positively …

Understanding The Role Of Ano1 In Oral Cancer, Mallary Forrest

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 2008, the gene ANO1 was discovered to encode a calcium activated chloride channel. This gene is located on the 11q13 locus, a locus that is commonly amplified in many cancers including cancer of the head and neck. ANO1 is situated in close proximity to genes associated with growth and apoptosis. As rapid proliferation and lack of apoptosis are hallmark characteristics of cancer, growth factors and apoptosis mediators are expected to be altered in cancer. But what does a calcium activated chloride channel have to contribute to cancer’s pathogenesis? Is it an active gene in cancer progression or is it …

The Investigation Of The Influence Of Long-Distance Running On Foot Volume In Healthy Female Collegiate Distance Athletes, Mufaro M. Hungwe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine the change, if any, in foot volume over time after exercise, specifically a long-distance 5 Km run. Five UNLV Women’s Track & Field and Cross- Country distance athletes (n = 5; 20 ± 1.87 years; 54.50 ± 3.71 kg; 160.88 ± 4.98 cm) were recruited to participate in this study. The dependent variables were foot volume and foot size. These variables were measured pre and post a 5 Km run at a self-selected somewhat hard pace over the independent variable time. Foot volumetrics were performed five times, (Pre-run, post- run(5 min), post-run(10 …

Climate And Soil Moisture Dynamics Inform Potential Climate Change Impacts On Available Moisture And Juvenile Tree Survival In Semiarid Forests, Carolyn R. Koehn

UNLV Theses, Dissertations, Professional Papers, and Capstones

Trees in semiarid forests and woodlands of the western United States need soil moisture to transpire and function. Juvenile trees are especially vulnerable during periods of low soil moisture as their rooting zones are smaller and shallower than those of adult trees. This thesis focuses on two soil moisture-driven aspects of semiarid forests that may be modified by climate change: seasonal soil moisture patterns and juvenile tree survival.

In chapter 1, I investigated the influence of precipitation on soil moisture across seasons, elevations, soil layers, and periods of low and high precipitation. I developed time-varying definitions of winter (snow accumulation), …

Development Of A Novel Cognitive-Motor Dual Task Assessment Battery In Neurodegenerative Disease, Jason Longhurst

UNLV Theses, Dissertations, Professional Papers, and Capstones

Automaticity --- the ability to perform a task with directing attentional resources to its completion --- is commonly reduced among individuals with neurodegenerative diseases. These automaticity deficits result in impaired functional and daily activities and are sensitive to subtle, subclinical impairments. However, current measurement of automaticity by dual task paradigms is methodologically limited. In order to gain insight into the current state of the literature regarding cognitive-motor interference in symptomatic and prodromal neurodegenerative disease, the author of this dissertation conducted a scoping review (Chapter 1). To address the methodological limitations of current measurement of automaticity, a new measurement tool was …

Estimation Of Spatial Change In Cropland Area And Evaluation Of Irrigation Performance In Imperial Valley Using Remotely Sensed Data, Usha Poudel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Imperial Valley (IV) in the US is an extensively irrigated agricultural region, which includes multiple crops changing on an annual and semiannual basis. The valley is facing grave concerns about water management due to its semi-arid environment, water intensive crops, and limited water supply. A simple, inexpensive, and repeatable method to detect changes in cropping patterns may assist irrigation managers to understand crop diversification and associated consumptive use. In addition, a spatial assessment of existing water irrigation system performance and productivity is crucial to benchmark and improve current water management strategies. This thesis estimates the spatial pattern of change …

Linking Extreme High Air Temperature Events To Wildfire And Environmental Variation To Water Balance Partitioning In The Western Us, Neil Savage

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chapter 1

Wildfire activity has increased across the western United States in recent decades, causing significant damage to ecosystem services and human communities. The Sierra Nevada region, in particular, has experienced substantial increases in the ignition frequency, severity, and extent of large wildfires. To partly disentangle the complex processes underlying wildfire risk, I developed a simple approach to link natural wildfire ignition patterns to changing seasonal temperatures and extreme high and low air temperature events across the Sierra Nevada region from 1992—2015. Extreme event analyses focused on the association between the magnitude and frequency of occurrence of extreme temperature events …

Differential Gene Expression In Starvation Selected Drosophila Melanogaster, Katherine Schultz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fruit flies that have been selected for starvation resistance can be used in experimental studies to study physiological processes. Both their genomes and their phenotypes, especially metabolism, change significantly as a result of artificial selection. Starvation selected flies develop slower and are larger due to higher lipid content as adults. We used RNAseq to study gene expression in third instar larval fat body tissue from selected and control lines at the same chronological time point, when the fed control (“FC”) lines were wandering, and the starvation selected (“SS”) lines were in the third larval instar but not yet wandering due …

Genomic Analysis Of Paenibacillus Larvae Bacteriophages, Casey Stamereilers

UNLV Theses, Dissertations, Professional Papers, and Capstones

American Foulbrood is the most destructive bacterial infection of the honeybee (Apis mellifera) and is caused by the Gram-positive, spore forming bacterium Paenibacillus larvae. Current treatment methods rely on antibiotics, but antibiotics treatments are experiencing a reduction in efficacy due to the recent rise in antibiotic resistant strains of P. larvae. This has been a major catalyst for exploration of alternative treatment methods. Phage therapy is an alternative treatment method that uses viruses that exclusively infect bacteria, known as bacteriophages (phages), to combat bacterial infections. Several experimental studies have shown that phages P. larvae phages are effective at lysing P. …

Juvenile Conifer Growth And Regeneration Across Diverse Climatic And Environmental Conditions In The Southwestern United States, Nikki L. Pirtel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Juvenile conifer germination, growth, and survival will play important roles in the persistence of coniferous forests and woodlands in the southwestern United States (SWUS), yet it is unclear how juvenile conifers allocate aboveground and belowground early growth and if growth differs between conifer and ecosystem types. Descriptions of growth characteristics may allude to the types of stress juveniles experience in their environments, how they morphologically respond to stress, and how they may be able to survive stress to persist in their current locations or expand into new areas. In Chapter 1, I described the growth characteristics of 4 juvenile conifer …