Life Sciences Commons^™

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, …

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 …

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 …

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 …

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 …

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. …

From (Un)Willingness To Involvement: Development Of A Successful Study Brand For Recruitment Of Diverse Msm To A Longitudinal Hiv Research, Paula M. Frew, Victoria A. Williams, Eve T. Shapiro, Travis Sanchez, Eli S. Rosenberg, Vincent L. Fenimore, Patrick S. Sullivan

Environmental & Occupational Health Faculty Publications

Background. HIV continues to be a major concern among MSM, yet Black MSM have not been enrolled in HIV research studies in proportionate numbers to White MSM. We developed an HIV prevention research brand strategy for MSM. Methods. Questionnaires and focus groups were conducted with 54 participants. Descriptive statistics and chi-square analyses were performed and qualitative data were transcribed and content analyzed to identify common themes. Results. Formative research results indicated that younger Black MSM (18–29 years) were less likely to think about joining prevention studies compared to older (≥30 years) Black MSM (, ). Qualitative and quantitative results indicate …

Accommodations For Patients With Disabilities In Primary Care: A Mixed Methods Study Of Practice Administrators, Jennifer Renee Pharr

Environmental & Occupational Health Faculty Publications

Structural barriers that limit access to health care services for people with disabilities have been identified through qualitative studies; however, little is known about how patients with disabilities are accommodated in the clinical setting when a structural barrier is encountered. The purpose of this study was to identify how primary care medical practices in the United States accommodated people with disabilities when a barrier to service is encountered. Primary care practice administrators from the medical management organization were identified through the organization’s website. Sixty-three administrators from across the US participated in this study. Practice administrators reported that patients were examined …

Custodianship Of The Walking Box Ranch Property: Project Compendium, Margaret N. Rees

Walking Box Ranch

This Project Compendium contains information and products resulting from a multi-year cooperative effort between the Bureau of Land Management (BLM) Las Vegas Field Office and University of Nevada, Las Vegas (UNLV) to care for and make available a BLM-owned Southern Nevada historic property: Walking Box Ranch. This project was focused, primarily, on the custodianship of the site through UNLV’s design, management, and coordination of a resident caretaker program, which was carried out by a series of excellent volunteers. University experts contributed to the decision-making process for necessary repairs and site security was enhanced through an innovative volunteer project open to …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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, …

The Putative Role Of Resveratrol In Sirt-1 Mediated Modulation Of The Vitamin D Pathway, Angelika Dampf Stone, Shane F. Batie, G. Kerr Whitfield, Mark R. Haussler, Peter W. Jurutka

American Association for the Advancement of Science Pacific Conference

The nuclear vitamin D receptor (VDR) modulates gene transcription in 1,25-dihydroxyvitamin D (1,25D) target tissues such as kidney, colon, and bone. The 1,25D hormone is derived from vitamin D in the skin or from the diet, and binds to and activates the VDR. We have previously shown that resveratrol, an antioxidant found in the skin of red grapes, has the ability to activate the VDR signaling pathway. Moreover, cells treated with both resveratrol and 1,25D resulted in an additive or even synergistic stimulation of VDR-mediated transcription compared to cells treated with 1,25D alone. Based on these initial results, experiments were …

The Effects Of Arch Taping On Shock Attenuation During Landing, Shun Jinnouchi

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to investigate the effects of two different arch taping techniques on shock attenuation during landing. Each subject (n=12, age 25.5 ± 3.37 years, height 1.73 ± 0.04 m, mass 82.06 ± 16.23) was instrumented with accelerometers at the leg and forehead (sample rate = 1000 Hz). Subjects performed landings from a 30 cm box under three taping conditions: no tape, Low Dye, and Weave. For each condition, subjects completed 5 landing trials. Rest was provided between each trial and order of conditions was counterbalanced. During each landing, accelerations were recorded at 1000 Hz for …

Additive Effects Of An External Focus And Enhanced Expectancy In Learning A Motor Skill, Luigi Antonio Pascua

UNLV Theses, Dissertations, Professional Papers, and Capstones

An external focus of attention in has been shown to produce better performance in practice and retention of a motor skill when compared to an internal focus or control conditions in which no attentional focus cues are given to the learner (for a review, see Wulf, 2012). Enhancing learner expectancy (e.g., via positive feedback) has also been shown to improve learning (e.g., Lewthwaite & Wulf, 2010). This study sought to investigate whether combining the positive effects of an external focus of attention with an enhanced learner expectancy (through positive social-comparative feedback) would enhance learning relative to either variable alone or …

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: …

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 …

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 …

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 …

Predicting Chest Press Strength From A 4rm Triceps Brachii Exercise In Trained Women, Krystina Nadia Moschella

UNLV Theses, Dissertations, Professional Papers, and Capstones

Determining maximal strength is important when developing a resistance exercise program for trained athletes. The most frequent strength procedure used to evaluate maximum strength is the 1RM test. However, risk of injury from a 1RM test increases for the athletes, therefore a 4RM test is used in the following study. The purpose of the study is to test whether there is a linear relationship between the bench press and the triceps rope extension exercise. A secondary purpose is the development of a prediction equation for the purpose of prescribing bench press exercise loads from triceps brachii loads using a 4RM …

Biomechanical Comparison Of A Rounded Outsole Shoe And Traditional Outsole Shoe, Sarah Horsch

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of the study was to determine the effects of shoe outsole design on maximum vertical acceleration and select kinematic parameters during level and uphill walking across phases of stance. Twelve participants, 7 males (75.1±9.3 kg, 173.6±3.6 cm, 22.9±3.5 yrs) and 5 females (56.5±5.1 kg, 158.3±4.5 cm, 25.4±11.1 yrs) granted written consent and preferred walking speed was determined. An accelerometer (480 Hz) was attached to the distal leg to measure maximum leg acceleration (Aleg) and an electrogoniometer (480 Hz) was placed on the back to measure sagittal lumbar motion (LumbarROM). Sagittal video capture (60 Hz) included thigh range of …

The Effects Of Chronic Calcium Dysregulation On Behavioral And Pathological Features Of Alzheimer's Disease, Jonathan Sabbagh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer's disease (AD) is a progressive neurodegenerative disorder whose etiology is unknown. Recent studies have implicated alterations in calcium homeostasis as a pathogenic contributor to AD. Calcium dysregulation has been observed in aged and AD brains, an event which could potentially facilitate the development of multiple pathologies observed in AD. Specifically, disrupting intracellular calcium levels in vitro has been demonstrated to increase amyloid-beta (Aβ) production, tau phosphorylation, and neuronal loss. However, there is a paucity of data on the behavioral and biochemical consequences of chronic in vivo perturbation of calcium homeostasis. In a series of experiments designed to evaluate the …