Physiology Commons^™

Acute Salivary Steroid Hormone Responses During Coalitional And Dyadic Competitions In Hong Kong Juvenile Children, Timothy Mchale

UNLV Theses, Dissertations, Professional Papers, and Capstones

A large body of research links testosterone and cortisol responses to competition during adulthood. Little psychoneuroendocrine research has explored salivary steroid hormone responses to competition during middle childhood. This project investigated the relationship between acute salivary steroid hormone change, performance, competitor type, and outcome effects in three different field studies, while controlling for Body Mass Index (BMI) and pubertal development, in a population of ethnically Chinese, Hong Kong juvenile children, 8-11 years of age. The relative dynamics of salivary steroid change were assessed during a 1) coalitional physical competition (soccer) in boys, 2) a non-physical mixed-sex coalitional competition (math contest), …

Factors Influencing Induction Of Desiccation Tolerance In Bryophytes: Redefining Fundamental Aspects Of The Organism’S Relationship With The Environment In Xeric Habitats, Joshua Lee Greenwood

UNLV Theses, Dissertations, Professional Papers, and Capstones

If one wishes to understand the ecological role, range, habitat preferences, selective pressures, reproduction, response to climate change, and the potential for survival under climactic change, range expansion and range contraction for species and populations of bryophytes, an understanding of their survival of the desiccated state, is essential. In order to further our understanding of desiccation tolerance in mosses, three projects were undertaken. The first of these investigated the nature of desiccation tolerance in mosses, specifically if desiccation tolerance can be induced; thereby providing a desiccation tolerant phenotype in a moss species generally considered desiccation sensitive (Physcomitrella patens, the model …

Thermal And Developmental Ecology Of Pupfish, Cyprinodon, Alexander Jones

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pupfish from the genus Cyprinodon are among the most endangered groups of fishes on the planet, with nearly 40% of species being threatened with extinction. These pupfishes are often assumed to be the most temperature tolerant of all fish, coping with temperatures as low as 0 °C and as high as 44 °C. However, conflicting data exist and certain measures of thermal tolerance are not markedly higher in pupfish compared to common game fish. Pupfish egg production and growth has been known to be hampered at temperatures well below what they apparently experience in nature. I addressed why eggs fail …

The Psychophysiological Correlates Of Personality, Trauma, Posttraumatic Stress Disorder And Social Support, Meghan E. Pierce

UNLV Theses, Dissertations, Professional Papers, and Capstones

Theories considering the etiology of psychopathy suggest that trauma exposure, specifically childhood maltreatment and sexual abuse, is related to the development of callous-unemotional traits in children and adolescents, which are precursors to psychopathic traits in adulthood. Furthermore, posttraumatic stress disorder has an opposite relationship with many of the emotional and behavioral components of the two-factor model of psychopathy. Specifically, PTSD is positively associated to IA and traits associated with it and negatively associated with FD. Thus, this study sought to expand upon the current theories of a trauma-based etiology of psychopathy by investigating the relationship between trauma, PTSD, and psychopathic …

Vitamin D Status And Bone Mineral Density In Female Collegiate Dancers And Cheerleaders, Tara Sue Kenny, Damon Mccune, Laura J. Kruskall, James Navalta, John C. Young

Kinesiology and Nutrition Sciences Faculty Research

Bone mineral density reflects an athlete’s cumulative history of energy availability, physical activity, and menstrual status, as well as nutritional and environmental factors. Although sports with high-impact loading are associated with higher bone mineral density than low-impact or non-impact sports, confounding variables are differences in the athletes’ body size and sport-specific training. The purpose of this study was to determine if bone mineral density (BMD) and vitamin D status are different between two groups of female collegiate athletes who have comparable body size/weight requirements, but who engage in qualitatively different training regimens. Full body, spine and dual femur BMD was …

Oral Vs. Nasal Breathing During Submaximal Aerobic Exercise, Chase Ovila Platt Lacomb

UNLV Theses, Dissertations, Professional Papers, and Capstones

When comparing oral breathing versus nasal breathing more volume of air can be transported through the oral passageway, but nasal breathing can lead to slower respiration rates and cleaner inspired air. The purpose of this study is to find the most efficient mode of breathing during different intensities of submaximal aerobic exercise. There were 9 males and 10 females that completed this study. First test was a VO₂ Max test, 3.0 mph for 3 minutes, with increases in 1.0 mph every minute after that. Using a regression equation running speeds were determined for each individual’s submaximal intensities. The desire …

Acute Testosterone Responses To Different Resistance Exercise Intensities, Robert Rietjens

UNLV Theses, Dissertations, Professional Papers, and Capstones

We investigated the acute testosterone response to four different resistance-training protocols. We observed testosterone levels pre-workout, immediately post-workout, and 60-minutes post-workout following a bout of upper body exercise at 70%,1 RM, 90% 1 RM, and lower body exercise at 70% 1 RM and 90% 1 RM. Total training volume was held constant but all amount of weight, sets, and reps were different. 10 healthy, male, resistance trained individuals volunteered for the study. The performed each exercise condition on separate days. Capillary blood was taken via finger prick at the time points specified above. Blood samples were analyzed via Accubind Testosterone …

Understanding How Honey Bee Flight And Senescence Are Connected Through Oxidative Stress., Joseph Margotta

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this dissertation was to exploit the tractability of the honey bee (Apis mellifera) to understand how the physiological and cellular mechanisms that determine the onset and duration of senescence are shaped by behavioral development and behavioral intensity. These data reveal how behavior can damage cells and consequently limit lifespan. The honey bee represents the ideal model to address these factors because age, behavior, functional senescence, and lifespan are easily manipulated independently of each other while in its natural environment. I determined if there was a cause-effect relationship between honey bee flight and oxidative stress by comparing damage …

Life History Tradeoffs And The Costs Of Reproduction In Arizona Bark Scorpions (Centruroides Sculpturatus), Michael Marie Webber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Tradeoffs in life history evolution result from conflicts in the time and energy that can be simultaneously invested in activities such as growth, reproduction, and survival. Reproduction is an energetically costly activity for organisms, and is known to elicit alterations in the daily activity patterns of individuals. I investigated reproductive tradeoffs in the Arizona Bark Scorpion,Centruroides sculpturatus. To better understand the nature of tradeoffs in this species, I examined the influence of reproductive state on the predatory efficiency and thermal preference of reproductive females. Further, I examined the influence of reproductive activities (i.e. gestation) on the ability of reproductive females …

Salivary Alpha-Amylase As An Indicator Of Body Stress Following An Acute Session Of Repetitive Jumping, Shaelee Allen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Determining body stress levels is important when developing training programs for athletes and rehab facilities. Stress levels during exercise are commonly measured using heart rate, oxygen consumption (VO₂), and blood biomarkers. These collection measures involve training on the part of the data collector and the participant, are invasive, and themselves elicit some stress. The purpose of this study is to test whether a 10-min repetitive jumping session will cause a significant increase in salivary alpha-amylase, a potential stress biomarker. This study also looks to determine if a 20-min recovery is enough time for amylase levels to return to …

The Grass Shrimp, Palaemonetes, Pugio: Hypoxic Influences On Embryonic Development, Christensen C. Javier

UNLV Theses, Dissertations, Professional Papers, and Capstones

Grass shrimp,Palaemonetes pugio, can survive in brackish waters and estuarine ecosystems despite the frequent oscillations and fluctuations in salinity, temperature and oxygen. AdultP. pugiohave the ability to osmoregulate (Romney and Reiber 2011), change cardiac parameters to tolerate temperatures (not yet published, Mika and Reiber) and oxyregulate (Guadagnoli and Reiber 2013). Manipulation of cardiac parameters allows for these methods of regulation. However, cardiac contraction and internal convection of oxygen do not occur until later stages of embryonic development. Studies focused on these morphological and physiological advantages may provide further understanding of the regulatory mechanisms within grass shrimp embryos, larvae and adults. …

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 …

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 …

Oxidative Stress For An Acute Bout Of Bikram Yoga In Healthy, Trained Adults, Kimberly Anne Trocio

UNLV Theses, Dissertations, Professional Papers, and Capstones

BACKGROUND:Generation of free radicals resulting in oxidative damage has been linked to cellular damage, aging, and human disease. Many studies have reported that physical exercise can contribute to oxidative stress. Further, exercise in a hyperthermic environment can promote additional oxidative stress. It is important to consider that practices in yoga may be beneficial in reducing oxidative stress according to some studies. The compound effects of exercise and hyperthermic exposure are experienced in the practice of Bikram yoga, the original "hot" yoga. Because Bikram yoga and other hot exercise classes are an increasingly growing fitness trend, it is necessary to investigate …

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 …

Exercise-Induced Neuroprotection In A Hemiparkinsonian 6-Hydroxydopamine Rat Model, Merrill Russen Landers

UNLV Theses, Dissertations, Professional Papers, and Capstones

Outside of finding a cure, one of the preeminent goals of research in Parkinson's disease (PD) is finding a neuroprotective treatment that when applied prior to the onset of the disease will decrease the risk and severity of the subsequent disease. One such treatment that has potential as a neuroprotective agent in PD is exercise. Several studies have found forced exercise to be protective of Parkinson's disease in adult rodent models; however, few of these studies have used a design wherein voluntary exercise was evaluated. Moreover, no study has used a true neuroprotective design in which exercise was applied prior …

Embryonic Development Of The Grass Shrimp, Palaemonetes Pugio, And The Influence Of Salinity On Cardiac Physiology, Amie Lynn Romney

UNLV Theses, Dissertations, Professional Papers, and Capstones

The grass shrimp, Palaemonetes pugio, inhabit the brackish waters along the Atlantic coast of North America and are a key component of the estuarine ecosystem. These decapod shrimp can tolerate large fluctuations in environmental parameters including daily and seasonal fluctuations in salinity between 0 to 55 parts per thousand (seawater at 30-32 ppt). Any observed distribution patterns of adult P. pugio in relation to salinity may be accounted for by their relative ability to tolerate a range in salinity and their ability to maintain internal water volumes and cardiac performance in the earliest life stage, the embryonic period. This thesis …

Effect Of Temperature And Oxygen Levels On Lactate Production In Palaemonetes Pugio, Robin Schofield, Teresa Mika, Carl Reiber

Festival of Communities: UG Symposium (Posters)

Oxygen delivery rates must keep pace with the increased metabolic rate observed in poikilothermic animals exposed to increased temperature if aerobic metabolism is to be maintained. Physical failure of the oxygen delivery system to meet these demands may be a mechanism of cardiac failure in crustaceans at temperature extremes. As part of the determination of the effect of temperature on the cardio-respiratory system, we are measuring whole animal lactate levels in grass shrimp acclimated to 20°C over temperature ranges in normoxic and hyperoxic conditions. Lactate levels are measured as an indicator of a switch from aerobic to anaerobic metabolism. Animals …

Physiological Implications Of Natural Versus Induced Arousal From Torpor, Jenifer C. Utz

UNLV Theses, Dissertations, Professional Papers, and Capstones

During the hibernation season, animals oscillate between periods of torpor and periods of interbout arousal (IBA). During torpor, body temperature is often near 0° C and metabolism is severely depressed. Oxygen consumption, a proxy for aerobic metabolism, may fall to 1% of active values. Many physiological processes including cardiovascular, respiratory, and cellular functions nearly cease. During the IBA, euthermic body temperature is restored and most systemic and cellular processes function at fully active levels. The transition period between these two physiologically dissimilar states is called arousal.

The rate of rewarming (RRW) during arousal was previously expected to progressively increase until …

The Role Of Larval Fat Cells In Starvation Resistance And Reproduction In Adult Drosophila Melanogaster, Jerell Roland Aguila

UNLV Theses, Dissertations, Professional Papers, and Capstones

The intricate life cycle of holometabolous insects includes well-defined larval and adult stages associated with feeding and non-feeding periods. The larval stage is distinguished by prevalent feeding and is necessary for supporting the animal as it quickly grows. The larval stage also serves as the period for the animal to obtain adequate energy stores, primarily in the larval fat body, to fuel the animal through the non-feeding pupal and immature adult stages. Acquiring sufficient energy stores is paramount for the success of the adult animal. In fact, certain insects, such as silkworms and mayflies, do not feed as adults and …

An Examination Of Body Composition Measurement Methods In Children, Robert Kaplan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction . Body-composition methods include underwater weighing (UWW), skinfold thickness (SKF), bioelectrical impedance (BIA), and the BOD POD. Although these techniques are used routinely, each has its inherent limitations, especially in children. Purpose . The purpose of this study was to examine the various methods of body composition in children. Methods . The body composition of 7 boys between the ages of 12-14 (13.1 +/- 1.1 years) was determined using the BOD POD, UWW, SKF, and BIA. Results . Percent body fat estimated from the BOD POD (21.9 +/- 7.8%BF) was not significantly different than the estimated percent fat from …

Integrated Responses Of Crustaceans Inhabiting Estuaries To The Challenges Of Feeding And Digestion In Low Salinity, Daniel Luke Curtis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Estuaries are highly productive and serve as vital habitats for numerous decapod crustacean species. However, the environmental conditions within estuaries are often highly dynamic and subject to large changes in salinity and temperature that occur on seasonal and tidal scales. Not all of the species occupying these habitats are adept in coping with changes in these environmental conditions. This dissertation describes the influence of low salinity conditions on the 1) habitat preference, 2) feeding behaviour and 3) digestive physiology of crustaceans inhabiting estuaries. I have primarily focussed on a weak osmoregulator, the Dungeness crab, Cancer magister , but have also …

Induction Of Integral Membrane Pam Expression In Att-20 Cells Alters The Storage And Trafficking Of Pomc And Pc1, Giuseppe D. Ciccotosto, Martin R. Schiller, Betty A. Eipper, Richard E. Mains

Life Sciences Faculty Research

Peptidylglycine alpha-amidating monooxygenase (PAM) is an essential enzyme that catalyzes the COOH-terminal amidation of many neuroendocrine peptides. The bifunctional PAM protein contains an NH2-terminal monooxygenase (PHM) domain followed by a lyase (PAL) domain and a transmembrane domain. The cytosolic tail of PAM interacts with proteins that can affect cytoskeletal organization. A reverse tetracycline-regulated inducible expression system was used to construct an AtT-20 corticotrope cell line capable of inducible PAM-1 expression. Upon induction, cells displayed a time- and dose-dependent increase in enzyme activity, PAM mRNA, and protein. Induction of increased PAM-1 expression produced graded changes in PAM-1 metabolism. Increased expression of …

Effects Of Sodium Intake, Furosemide, And Infusion Of Atrial Natriuretic Peptide On The Urinary And Metabolic Clearances Of Arginine Vasopressin In Normal Subjects, Arnold M. Moses, Carol Jones, Carolyn B. Yucha

Nursing Faculty Research

Arginine vasopressin (AVP) and atrial natriuretic peptide (ANP) have important influences on water and electrolyte metabolism, and studies on the interactions between these hormones may have important implications. We have investigated the effects of sodium intake, furosemide, and infusion of ANP on the urinary and metabolic (nonurinary) clearances of AVP in hydrated normal subjects. On a high sodium diet there was an increase in urine volume, sodium excretion, osmolal clearance, plasma ANP concentration, and urinary clearance and fractional excretion of AVP, with a decrease in PRA. The infusion of furosemide increased urine volume, sodium excretion, osmolal clearance, and PRA, but …