Life Sciences Commons^™

Field Testing The Upright Versus The Aero Cycling Position, Curtis Scrugham

UNLV Theses, Dissertations, Professional Papers, and Capstones

Body position can be of great importance to athletes who want to maximize their performance on the bike. Aerodynamic resistance can account for 70-90% of resistance encountered by cyclists, and a strategy used to reduce this resistance is riding in the aero position Research has been done in the lab to determine if there are trade-offs to using this position (Jobson et al. 2008, Welbergen and Clijsen 1990, Hubenig, Game and Kennedy 2011, Peveler 2004, Origenes et al. 1993, Ryschon and Stray-Gunderson 1991, Gnehm et al. 1997, Ashe et al. 2003). . Researchers have reported that riders untrained in the …

Ichnology And Paleoecology Of The Jurassic Aztec Sandstone, Heather Marie Stoller

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this study I describe and interpret tracks and trackways of the Jurassic Aztec Sandstone of southern Nevada and southern California. This study involved mapping of all known tracks and trackways, including foot length, stride length, and trackway width. Photogrammetric data, collected by Bureau of Land Management scientists, were utilized for several trackways in Red Rock Canyon National Conservation Area.

More than three hundred tracks belonging to five ichnotaxa were documented within the Aztec Sandstone, including about 165 tridactylGrallator, 250 tetradactyl (four-toed)Brasilichniumtracks, and 7 arthropod trackways ofOctopodichnusandPaleohelcura. Four of the five ichnotaxa were not previously reported from the Aztec Sandstone. …

Vitamin D Status And Bone Mineral Density In Triathletes, Michelle Konstantarakis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The purposes of this study were first to assess the vitamin D status and bone mineral density (BMD) in male and triathletes (N=15), female triathletes (N=13), and non-athletes (N=14), and to determine if circulating vitamin D was correlated with body composition, BMD, dietary calcium and vitamin D intake in triathletes. The second purpose was to determine if triathletes have a different level of serum vitamin D, body composition, BMD, dietary calcium and vitamin D intake then non-athletes. The third purpose was to determine if BMD was correlated with body composition (body mass, percent body fat, BMI) in triathletes.

Methods: …

Evaluation Of The Relationship Between Nutrition Knowledge And Disordered Eating Risk In Female Collegiate Athletes, Amy L. Miracle

UNLV Theses, Dissertations, Professional Papers, and Capstones

Involvement in collegiate sports among female athletes is at an all-time high with approximately 198,000 currently participating, (National Collegiate Athletic Association, 2012). With this increase in female participation in collegiate sports, the pressures of sport participation and academics lead some women to engage in harmful eating behaviors. These harmful eating behaviors may lead to the development of disordered eating (C. Johnson, Powers, & Dick, 1999; Quatromoni, 2008; Reel, SooHoo, Petrie, Greenleaf, & Carter, 2010; Reinking & Alexander, 2005). Many factors have been identified as contributing to the development of disordered eating but nutrition knowledge or lack thereof, has yet to …

Assessing Growth Response To Climate Controls In A Great Basin Artemisia Tridentata Plant Community, Lorenzo F. Apodaca

UNLV Theses, Dissertations, Professional Papers, and Capstones

An assessment of the growth response of key vegetative species to climatic variability is vital to identifying possible local impacts on ecosystems faced with imminent climate change. With current climate projections in Nevada predicting a shift to an even more arid climate with greater year-to-year variability, the imperative exists to identify the effects of specific climatic controls on plant growth and to research methods to assess large-scale vegetative changes, especially in more remote areas where readily available data sets may be lacking. This study utilized annual growth ring indices constructed from big sagebrush (Artemisia tridentatassp.tridentata) stems collected in Spring Valley, …

Sex Determination Using Discriminant Function Analysis In Hispanic Children And Adolescents: A Lateral Cephalometric Study, Alyssa E. Sprowl

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lateral cephalometric radiographs have been used for years to help diagnose skeletal and dental patterns in Orthodontics. Within the last decade, these radiographs have caught the interest of the department of Anthropology for the identification of gender within the adult and adolescent population. Numerous publications have been made but failed to identify sexual dimorphism in the pre-adolescent population. 303 lateral cephalograms of pre and post Latino adolescence age ranging from 6.5 to 17.9 years old were obtained from University of Nevada, Las Vegas (UNLV) digital database. 25 variables were identified and plotted with all linear and angular measurements transferred into …

Time-Dependent Random Effect Poisson Random Field Model For Polymorphism Within And Between Two Related Species, Shilei Zhou

UNLV Theses, Dissertations, Professional Papers, and Capstones

Molecular evolution is partially driven by mutation, selection, random genetic drift, or combination of the three factors. To quantify the magnitude of these genetic forces, a previously developed time-dependent fixed effect Poisson random field model provides powerful likelihood and Bayesian estimates of mutation rate, selection coefficient, and species divergence time. The assumption of the fixed effect model that selection intensity is constant within a genetic locus but varies across genes is obviously biologically unrealistic, but it serves the original purpose of making statistical inference about selection and divergence between two related species they are individually at mutation-selection-drift inequilibrium. By relaxing …

Vitamin And Mineral Intake Relative To The Dris In Young Adults, Samantha M. Coogan

UNLV Theses, Dissertations, Professional Papers, and Capstones

INTRODUCTION: In general, most college-aged students live highly, and newly, independent lives. Although campuses offer wide varieties of food choices, most choices do not meet the standards set by the RDA or DRIs, per NHANES 1999-2000.

METHODS: In order to document these eating patterns, 1001 male (n=379) and female (n=622) college-aged students quantified dietary intake for three consecutive days using the food log method. Assessment reports were generated and analyzed in order to determine the percentage of the DRI in both males and females, and groups with a BMI of less than 20 and greater than 30. Tests for correlation …

Efficacy Of Gold Silica Nanoshells And Gold Nanorods For Photothermal Therapy Of Human Glioma Spheroids, Suyog Jung Chhetri

UNLV Theses, Dissertations, Professional Papers, and Capstones

Gold-based nanoparticles including gold-silica nano-spheres and gold nano-rods have been investigated for a number of therapeutic and diagnostic applications. The ability of these nanoparticles to convert light into heat energy makes them particularly appealing for photothermal therapy in which cancer cells are destroyed via light-induced heat generation. The overall objective of the study is to compare the efficacy of gold-silica nano-spheres and gold nano-rods in an in vitro system consisting of human brain tumor (glioma) spheroids.

Delivery of the nanoparticles to the spheroids was accomplished using murine macrophages. Nanoparticles (spheres or rods) were incubated with macrophages for 24 hours. Thereafter, …

Understanding Basin Specific Life History Characteristics Of Lake Mead Quagga Mussels (Dreissena Bugensis) And A Potential Treatment Using Uv Radiation In Laboratory Studies, Melissa Thaw

UNLV Theses, Dissertations, Professional Papers, and Capstones

The quagga mussel (Dreissena bugensis) is an aquatic invasive species that is spreading throughout Lake Mead and other western waterways. Unlike their native waters in Eurasia, Lake Mead exhibits year round warm temperatures, high calcium levels and a lack of natural predators, all of which are very favorable conditions for their growth and spread. Dreissena bugensis reproduce and colonize hard surfaces rapidly, where they filter large amounts of water. They disrupt the aquatic food chain and interfere with infrastructure that is exposed to lake water. There is an urgent need to understand Dreissena bugensis life history characteristics within this new …

Eating Pathology, Supplement Use, And Nutrition Knowledge In Collegiate Athletes, Holly Beth Lapota

UNLV Theses, Dissertations, Professional Papers, and Capstones

Eating pathology (e.g., body dissatisfaction, binge eating, purging, restrictive eating) and substance use (e.g., dietary supplements, legal and illegal drugs) proliferate university settings in the United States. Within university settings, athletes appear to be at particularly high risk for eating pathology and supplement use due to the external pressures to be attractive, the need to perform at optimal levels, and the specific characteristics of sports in which they participate. Furthermore, the degree to which athletes understand what constitutes healthy eating and exercise habits is understudied and may relate to eating pathology and supplement use. To build on existing research, the …

Alternations Of Nmda And Gabab Receptor Function In Development: A Potential Animal Model Of Schizophrenia, Monica Bolton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Schizophrenia is a debilitating mental disorder that affects up to 3% of the world population. The behavioral symptoms are categorized into positive and negative symptoms, which appear during late adolescence/early adulthood. Unfortunately, the underlying cellular and molecular mechanisms of the disease are poorly understood. Several hypotheses exist to explain mechanisms contributing to these behavioral alterations. One model proposes that a reduced function of the NMDA glutamate receptor on specific GABAergic interneurons may be responsible for deficits in schizophrenia. Post-mortem investigations provide evidence of reductions in both glutamate and GABA-related proteins in patients with schizophrenia. Further, GABAergic interneurons that are activated …

The Effect Of Temperature Extremes On Cardiorespiratory Function In The Grass Shrimp Palaemonetes Pugio: Oxygen Limited Thermal Tolerance, Teresa Mika

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aquatic poikilothermic animals must either cope with or compensate for the mismatch in oxygen supply and demand present at high temperatures. Oxygen limited thermal tolerance explains how aerobic scope is limited by insufficient oxygen supply and sets the performance window in animals. This work explores the effects of temperature on the different components of the oxygen delivery system, in both normoxic and hyperoxic conditions to determine if supplying more oxygen to the system mitigates the effects of temperature effects on the cardiorespiratory system and extends oxygen limited thermal tolerance to higher temperatures. The effect of temperature and oxygen condition was …

The Effect Of Balance Training With An Innovative Approach Compared To Traditional Balance Exercises, Brian Curtis Waite

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to evaluate the use of an X Box 360 KinectTM game as a modality for improving balance. Specifically, this study explores the use of the Target Kick mini game on Kinect SportsTM as a tool for VR rehabilitation. Subjects (N=18, age 23.3 ±2.87 yrs, mass 71.83 ±15.25 kg, height 168.4 ±7.79 cm) with no lower extremity injury were randomly placed into three groups (X Box n = 6, Traditional n = 6, and Control n = 6). The X Box (XBOX) group performed ten minutes of balance training by playing an X Box game …

Paleoecology Of Late Pleistocene Megaherbivores: Stable Isotope Reconstruction Of Environment, Climate, And Response, Aubrey Mae Bonde

UNLV Theses, Dissertations, Professional Papers, and Capstones

Late Pleistocene megaherbivore communities of the Pacific and Mountain West states of California and Nevada are under-analyzed in regard to ecological function (diet, mobility, niche partitioning, and range of ecological tolerance). Stable isotope analysis is a powerful tool that is known to recover primary paleodiet and paleoenvironmental information from biogenic materials, such as enamel and dentin. This dissertation explores the use of carbon and oxygen stable isotopes in Late Pleistocene (40-10 Ka) megaherbivore teeth to gain a better understanding of inter- and intra-specific behavior and reconstruct Late Pleistocene ecosystems of California and Nevada. Radiocarbon dates exist for most of the …

Relationship Of Global Dna Methylation With Cardiovascular Fitness And Body Composition, Michael Steele Jarrett

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: Global DNA Methylation (GDM), an epigenomic modification has been linked to the development of Cardiovascular Disease and its risk factors. Purpose: The purpose of this study was to determine if there is a significant correlation between GDM and cardiovascular fitness, as well as, measures of body composition. Methodology: 26 apparently healthy, adults (11 males) completed a physical activity and diet questionnaire, as well as, had a small blood sample (600μL) collected via finger prick for the determination of GDM. Body composition was assessed by means of a Dual-Energy X-ray Absorptiometry (DEXA) scan, while cardiovascular fitness was evaluated by the …

The Acute Effect Of Two Hip External Rotator Stretches On Range Of Motion, Cody Brian Bremner

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to evaluate the acute effect of two commonly used static stretches on hip internal rotation passive range of motion (HIR-PROM). Participants (n=30, 15 male, 15 female; 22±1.8 yrs.; 173.5±8.5cm; 73.8±12.7 kg) were randomly assigned (with gender controlled) to one of three groups: control (C), figure 4 stretch (F4), and modified lunge stretch (ML). Pre and post-test HIR-PROM was measured on each participant's non-dominant hip (28 left, 2 right). HIR-PROM was measured from the prone position; the knee was flexed to 90° and the hip was passively internally rotated. After the pretest, each participant completed …

Kinematic Analysis Of Axial Rotations And The Effects Of Stress Selection On Takeoff Flight Performance, Michael L. Brewer

UNLV Theses, Dissertations, Professional Papers, and Capstones

The importance of flying insects cannot be understated; without them as pollinators, the great diversity of flowing plants could not have occurred. Flight requires a suite of highly derived morphological and physiological characteristics that may limit the evolutionary responses of other life history traits.

To investigate the complexities of maneuvering flight, I used high-speed videography to analyze wing and body motions in the HoverflySyritta pipiens(Order: Diptera) during horizontal turns called saccades. I characterized the saccades by calculating the instantaneous rotational velocities throughout the saccade, maximum rotational velocity, and the mean rotational velocity. I then compared the shape of the rotational …

Integrating, Developing, And Testing Methods To Generate More Cohesive Approaches To Biogeographic Inference, Mallory Elizabeth Eckstut

UNLV Theses, Dissertations, Professional Papers, and Capstones

As a fundamental component of the developing discipline of conservation biogeography, broadscale analyses of biotic assembly and disassembly across multiple temporal and spatial scales provide an enhanced understanding of how geologic transformations and climate oscillations have shaped extant patterns of biodiversity. As with any scientific field, there are limitations in the case of biogeographic historical reconstructions. Historical reconstructions are only as robust as the theoretical underpinnings of the methods of reconstruction (including data collection, quality, analysis, and interpretation). Nevertheless, historical reconstructions of species distributions can help inform our understanding of how species respond to environmental change.

My dissertation takes a …

The Evaluation Of Water Storage In Death Valley Using Grace Satellite Data, Maile Sweigart

UNLV Theses, Dissertations, Professional Papers, and Capstones

As drought conditions spread across the United States, concerns over water supplies, water use, and water management policies are growing and possible contributing environmental factors are continually being scrutinized. This thesis examines Death Valley as an analog for Southern Nevada and utilizes NASA EOS data, combined with ancillary climate data, to assess the effect of decadal climate variability on groundwater storage in the Death Valley area. Historical climate data, combined with satellite imagery observations, were compiled and calculated for analyses. Conclusions derived from statistical analyses infer trends between GRACE (Gravity Recovery and Climate Experiment) satellite data and fluctuating levels of …

Firefighter Fitness-For-Duty Medical Screening: A Peer Review Quality Improvement Pilot, Julie Collings Rochefort

UNLV Theses, Dissertations, Professional Papers, and Capstones

Despite the overwhelming evidence that sudden cardiac death is the most frequent cause of firefighter fatalities, many fire departments do not have a program to measure or maintain basic firefighter fitness and health. This project evaluated and compared medical screening outcomes of four industrial fire brigades within a multinational oil and gas corporation and introduced a quality improvement plan. The goal of this project was to apply the evidence and measure outcomes to determine the most effective way to ensure that firefighters in a corporate setting are healthy. This was accomplished by utilizing established guidelines in developing an educational program …

Dispersal Ecology Of Desert Mosses Along Gradients Of Elevation, Wildfire Disturbance And Local Niche, Robert Joseph Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Much of the variation in plant communities can be explained by the dispersal of individuals across landscapes, an ecological process that contributes to clinal variation, post-disturbance recovery and habitat occupancy. The role of dispersal is of particular concern for Mojave Desert plant communities that may not be able to tolerate recent departures from historical fire regimes. The aim of this thesis was to infer how dispersal is reflected by patterns of diversity in disturbed and undisturbed bryophyte communities in the Spring Mountains of southern Nevada. Chapter 2 presents an examination of sub-surface bryophyte communities (propagule "soil-banks") along a 1400 m …

Effects Of Footstrike Pattern On Low Back Posture, Shock Attenuation, And Comfort During Running, Traci L. Delgado, Emilia Kubera-Shelton, Robert R. Robb

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: Barefoot running (BF) is popular in the running community. Biomechanical changes occur with BF, especially when initial contact changes from rearfoot strike (RFS) to forefoot strike (FFS). In addition, changes in lumbar spine range of motion (ROM), particularly involving lumbar lordosis, have been associated with increased low back pain (LBP). However it is not known how changing from RFS to FFS affects lumbar lordosis or LBP. Thus, the purpose of this study was to determine if a change from RFS to FFS would change lumbar lordosis, and/or decrease shock attenuation, and/or change comfort levels in healthy recreational/experienced runners.

Methods: …

Understanding Effects Of Changes In Land Use, Environmental Parameters, Habitat Characteristics On The Great Basin Aquatic Invertebrates Using Ecological Stoichiometric Theory, Knut Mehler

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many freshwater ecosystems in the Great Basin have undergone dramatic alteration over the past decades due to groundwater withdrawal, water diversion and changes in land use. These changes have affected benthic food web dynamics by altering the availability of chemical key elements for primary and secondary producers, by loss of biodiversity and extinction of endemic species. However, only few studies are available that addresses the link between changes in land use, habitat characteristics and its effects on benthic macroinvertebrates (BMI) communities comprehensively and little attention has been given to integrating physiochemical aspects to link ecosystem functions.

This dissertation analyzes the …

The Effects Of Starvation Selection On Drosophila Melanogaster Life History And Development, Lauren A. Reynolds

UNLV Theses, Dissertations, Professional Papers, and Capstones

In nature, animals may endure periods of famine to complete their life cycles. Starvation stress will increase in populations as climates around the world change. To predict how populations may respond to such a stress, laboratory experimentation becomes essential. The evolutionary process of adaptation, its innovations and their trade-offs, can be studied in populations experiencing starvation stress. For this purpose outbred populations ofDrosophila melanogasterwere selected for starvation resistance in the laboratory.

After 60+ generations of starvation selection the starvation-selected flies have gone from surviving 2-3 days without food to 12-14 days without food. How this amazing feat of resistance is …

Development And Implementation Of A Video-Based Activity Preference Assessment For Children With Autism And Their Parents, Lena Sankovich

UNLV Theses, Dissertations, Professional Papers, and Capstones

Development and Implementation of a Video-Based Physical Activity Preference Assessment for Children with Autism and Their Parents

Individuals with autism often lack the necessary motivation to engage in physical activity. In addition, due to the characteristics defining autism, such as deficits in social skills, motor coordination, and behavior, individuals with autism are less likely to participate in physical activity with their peers than individuals without autism. Additionally, poor motor functioning, sedentary lifestyle, lack of information and lack of access to physical activity may be barriers to physical activity for individuals with developmental disabilities. These barriers, in addition to the characteristics …

The Role Of Oswrky71 And Its Interacting Proteins In Seed Germination And Early Growth Of Cereal Grains, Margaret Ja Shin

UNLV Theses, Dissertations, Professional Papers, and Capstones

During seed germination and early seedling growth, complex molecular and physiological events occur in rice (Oryza sativa) and other cereal grains. As the seed transitions to vegetative tissue, it responds to both favorable and unfavorable environmental conditions and is vulnerable to attack by predation and disease. Although seeds are relatively small and tender in size, extensive and sophisticated molecular networks enables the immobile seed to grow, survive and adapt in its environment. One of the networks I am interested in is in the crosstalk between the gibberellin (GA) and abscisic acid (ABA) signaling pathways. These pathways are interesting because they …

Effect Of Dehydration On Concomitant Measures Of Cognitive Function And Balance, Stephanie Marie Watson

UNLV Theses, Dissertations, Professional Papers, and Capstones

During activities of daily living, there are demands placed on the body both cognitively and physically. These demands are multiplied when performing an athletic endeavor. Many studies have demonstrated the negative impact dehydration has on cognitive and muscle functions, independently. The purpose of this study is to investigate the effect of dehydration on central nervous system and peripheral nervous system fatigue as expressed through concomitant factors of cognitive function and balance. Subjects were to consist of 20 participates aged 18-35 years old who reported running a minimum of 45 minutes per exercise bout at least 3 times per week. The …

What Can Biochemistry Students Learn About Protein Translation? Using Variation Theory To Explore The Space Of Learning Created By Some Common External Representations, Thomas J. Bussey

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biochemistry education relies heavily on students' ability to visualize abstract cellular and molecular processes, mechanisms, and components. As such, biochemistry educators often turn to external representations to provide tangible, working models from which students' internal representations (mental models) can be constructed, evaluated, and revised. However, prior research has shown that, while potentially beneficial, external representations can also lead to alternative student conceptions.

Considering the breadth of biochemical phenomena, protein translation has been identified as an essential biochemical process and can subsequently be considered a fundamental concept for biochemistry students to learn. External representations of translation range from static diagrams to …

Effect Of Racing Flats On Running Economy In Male Adolescent Runners, Paul Hafen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to investigate whether running economy differs in racing flats versus standard running shoes in high school cross-country runners. In order to measure running economy the oxygen cost of running (mL O₂∙kg^-1∙min^-1) was measured in 20 male adolescent runners (mean age = 16.25 ± 0.97 years, 5 km best time = 17.52 ± 0.78 min) when running two separate trials at a controlled speed. The speed was determined by estimating treadmill running speed at 85% of each runner's VO_2max. Each trial required the participants to run while …