Digital Commons Network^™

Preferential Quadriceps Activation In Female Athletes With Incremental Increases In Landing Intensity, Kevin R. Ford, Gregory D. Myer, Laura C. Schmitt, Timothy L. Uhl, Timothy E. Hewett

Physical Therapy Faculty Publications

The purpose of this study was to identify alterations in preparatory muscle activation patterns across different drop heights in female athletes. Sixteen female high school volleyball players performed the drop vertical jump from three different drop heights. Surface electromyography of the quadriceps and hamstrings were collected during the movement trials. As the drop height increased, muscle activation of the quadriceps during preparatory phase also increased (p < .05). However, the hamstrings activation showed no similar increases relative to drop height. Female athletes appear to preferentially rely on increased quadriceps activation, without an increase in hamstrings activation, with increased plyometric intensity. The resultant decreased activation ratio of the hamstrings relative to quadriceps before landing may represent altered dynamic knee stability and may contribute to the increased risk of ACL injury in female athletes.

Zeolite‐Based Algae Biofilm Rotating Photobioreactor For Algae And Biomass Production, Ashton M. Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alkaline conditions induced by algae growth in wastewater stabilization ponds create deprotonated ammonium ions that result in ammonia gas (NH₃) volatilization. If algae are utilized to remediate wastewater through uptake of phosphorus, the resulting nitrogen loss will hinder this process because algae generally require a stoichiometric molar ratio of N₁₆P₁. Lower ratios of N/P due to loss of ammonia gas will limit the growth and yield of algae, and therefore will reduce phosphorus removal from the water phase into the algae phase. In order to reduce nitrogen loss through volatilization, an ammonium selective zeolite, …

Effect Of Adjunct Cultures, Sodium Gluconate, And Ripening Temperature On Low-Fat Cheddar Cheese Flavor, Rebekah M. Lance

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Low-fat Cheddar cheese flavor is different from full-fat Cheddar cheese and is not acceptable to many consumers. This 2-part experiment was designed to examine effects adjunct cultures have on low-fat Cheddar cheese flavor as determined through descriptive analysis and consumer feedback.

In Part 1, low-fat (5%) Cheddar cheese was produced in duplicate, using 6 combinations of DVS850, LH32, CR540, CRL431, Emfour, and CR319 bacterial cultures. Due to a previously observed positive effect by sodium gluconate on low-fat cheese flavor, each replicate was split into treatments of 0.0% and 0.8% sodium gluconate. Each of these treatments was then split into ripening …

Studies Of The Distinguishing Features Of Nadph:2-Ketopropyl-Coenzyme M Oxidoreductase/Carboxylase, An Atypical Member Of The Disulfide/ Oxidoreductase Family Of Enzymes, Melissa A. Beighley-Kofoed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The metabolism of propylene in Xanthobacter autotrophicus occurs via epoxypropane formation and subsequent metabolism by a three-step, four-enzyme pathway, utilizing the atypical cofactor Coenzyme M (CoM) to form acetoacetate. The last step in the epoxide carboxylase pathway is catalyzed by a distinctive member of the disulfide oxidoreductase (DSOR) family of enzymes, NADPH:2-ketopropyl CoM oxidoreductase/carboxylase (2-KPCC). 2-KPCC catalyzes the unorthodox cleavage of a thioether bond and successive carboxylation of the substrate. The focus of the research presented in this dissertation aims to elucidate the details of 2-KPCC that allow it to perform chemistry unconventional for typical DSOR members. Sitedirected mutagenesis was …

Community Level Effects Of Vegetation Architecture And Prey Availability: A Study Of Ground-Dwelling Arthropods In A Shrub-Steppe Ecosystem, Mary E. Pendergast

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes to vegetation architecture within a natural habitat can have profound impacts upon ecological community function, but the relative influence of vegetation architecture itself and potential indirect influences of associated food resources are often difficult to disentangle. I present the results of a three-year study designed to address the community level impacts of changes in big sagebrush (Artemisia tridentata) architecture and associated prey availability upon the ground-dwelling arthropod community. Three experimental sagebrush architecture treatments (low, intermediate, and high foliage density) and two levels of prey insect availability treatment (natural and baited/increased prey availability) were imposed in a sage-steppe …

The Decline And Conservation Status Of North American Bumble Bees, Jonathan B. Koch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several reports of North American bumble bee (Bombus Latreille) decline have been documented across the continent, but no study has fully assessed the geographic scope of decline. In this study I discuss the importance of Natural History Collections (NHC) in estimating historic bumble bee distributions and abundances, as well as in informing current surveys. To estimate changes in distribution and relative abundance I compare historic data assembled from a >73,000 specimen database with a contemporary 3-year survey of North American bumble bees across 382 locations in the contiguous U.S.A. Based on my results, four historically abundant bumble bees, B. …

Ecologically-Based Manipulation Practices For Managing Bromus Tectorum-Infested Rangelands, Beth Fowers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cheatgrass (Bromus tectorum) is an invasive annual grass common in several semiarid plant communities in the western U.S. B. tectorum presence increases fire frequency and size, reducing species diversity, and leading to annual species-dominated systems with inconsistent livestock forage potential and degraded wildlife habitat value. Most efforts to manage B. tectorum-dominated rangelands have focused on controlling the plant itself rather than addressing the causes of vegetation change. An alternative approach, ecologically-based invasive plant management (EBIPM), identifies treatments that can alter factors associated with the causes of succession, leading to a more desirable vegetation state. This study utilized …

Testing Mediated Effects Of A Sex Education Program On Youth Sexual Activity, Paul James Birch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Empirical investigations have identified hundreds of factors that predict whether youth engage in sexual activity (YSA). To promote optimal health and the avoidance of unhealthy or problematic outcomes that can result from YSA, sex education programs have been extensively developed and evaluated. Many evaluations have identified the effect of the program on immediate outcomes such as attitudes and intentions, others have examined subsequent behavioral and health outcomes, and some have done both. The purpose of this study was to extend the evaluation literature by testing a mediated effects model. A sex education program was found to have significant immediate effects …

Effects Of Non‐Surface‐Disturbing Treatments For Native Grass Revegetation On Cheatgrass (Bromus Tectorum L.) Metrics And Soil Ion Availabilities, Jan C.R. Summerhays

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several restoration methods intended to increase the success of aerially‐seeded perennial grasses were assessed to determine their effects on cheatgrass metrics and soil nutrient bioavailabilities. These methods were: 1) imazapic herbicide application (140 g ai ∙ ha^-1, 210 g ai ∙ ha^-1, and no application [control]), 2) vegetation manipulation treatments (50% sagebrush overstory thinning, 100% sagebrush overstory thinning, sagebrush overstory and/or vegetative thatch burning, and no manipulation [control]), and 3) alternative seeding treatments (aerial seeding with raking, aerial seeding with activated carbon [AC] addition, aerial seeding with sucrose addition, and regular aerial seeding [control]). Treatments were …

The Impact Of Team-Based Learning’S Readiness Assurance Process On Virtually Isolated Adults, Matthew W. Barclay

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to test the effectiveness of the readiness assurance process of team-based learning (TBL) in virtually isolated settings. Many Internet sites offer courses for adults to use on their own without access to mentors or other learners. However, educational theory suggests that people learn better with others than by themselves. The focus of this investigation was whether the inclusion of the readiness assurance process would increase participants’ levels of learning based on Bloom’s revised taxonomy within the limits of virtual isolation.

In this study an experimental pretest-posttest design was employed. Using a 2- day mini-course …

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 …

Synthesis Of A Chemical Probe For Identification Of Ger Receptor Proteins Of Bacillus Anthracis, Hyelee Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bacillus anthracis,a gram positive, endospore-forming, rod-shaped, aerobic bacterium, is the causative agent of anthrax. A key step in the pathogenic cycle is the spore germination, where the dormant spore transforms into a metabolically active cell. This allows B. anthracis to proliferate and secrete toxins. It is believed that spore germination is triggered when small molecules, known as germinants, are recognized by germination (Ger) receptor proteins located in the inner membrane of spores. Most Ger proteins are encoded by tricistronic operons, resulting in three distinct products, the A-, B-, C-subunits. Genomic sequencing showed that B. anthracis has seven ger receptor …

Groundwater Contamination Potential In Northern Nevada From Mining, Associated Communities, And Agriculture As Forecasted By Two Vulnerability Methods, John L. Swatzell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two methodologies, DRASTIC and the NDEP method, were used to compare the groundwater vulnerability of mining, associated towns, and agricultural areas in northern Nevada. The DRASTIC and NDEP methods were compared to determine which method produces a more accurate depiction of vulnerability. Vulnerability maps were created using the United States Environmental Protection Agency's (USEPA) DRASTIC and Nevada Department of Environmental Protection (NDEP) methodologies. The DRASTIC map uses seven aspect layers of geologic and hydrologic information with assigned values and weights that are applied to a mathematical equation. The NDEP method uses field data collection for potential contaminant sources and well …

Examining The Experience Of Recent War Veterans Who Report Posttraumatic Stress Disorder, Neda C. Raymond

UNLV Theses, Dissertations, Professional Papers, and Capstones

Posttraumatic stress disorder (PTSD), an anxiety disorder that develops following exposure to a traumatic event, has long been associated with military combat. Despite the well-documented negative effects of PTSD, careful, in-depth accounts of the experience of those suffering from PTSD are rare. The present study employed Descriptive Experience Sampling (DES) to explore the inner experience of seven Operation Iraqi Freedom (OIF) or Operation Enduring Freedom (OEF) veterans with combat-related PTSD. Potential participants completed the PTSD Checklist - Military Version to determine the presence and severity of PTSD symptomatology. Participants who reported significant symptoms of combat-related PTSD participated in DES. A …

Historical Diversification Of Montane Herpetofauna Within And Between The Sierras Of Mexico, Robert William Bryson Jr.

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mexican highlands consist of four major mountain ranges spanning most of mainland Mexico. The evolutionary history of the Mexican highlands has been shaped by various geological and climatic events over the past several million years. The relative impacts of these historical events on diversification in montane taxa, however, remains uncertain. I used mitochondrial DNA data from three widely distributed species complexes of lizards as a model system to exemplify the potential roles of Neogene mountain formation and Quaternary climate change on timing and tempo of diversification across the Mexican highlands. My results suggested strong geographic partitioning of genetic variation …

Climate And Vegetation Change In The Newberry Mountains, Southern Clark County, Nevada, Ross Joseph Guida

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ecological studies have shown worldwide that vegetation is being affected by climate change. Species are shifting to new elevations and physiographic positions to adapt to changes in their environment. More specifically, paleoecology studies in the Mojave Desert have shown shifting vegetation patterns in response to past warming and precipitation changes. Recent studies have shown mortality among desert plants related to extended drought and warming. However, few studies have shown how the geographic distribution of Mojave Desert species has changed during this most recent period of warming. This study addresses this gap in the literature by focusing on several plant species …

Purchaser Preferences On Carbon Labels: Conventional Vs. Organic Milk, Mustafa Ozkan

Graduate Theses and Dissertations

Over the past several years, there has been growing attention concerning global warming/climate change and how humans are contributors. It is known that agricultural production is a main contributor of greenhouse gas emissions and the livestock sector is particularly significant because it is quoted as having between 3 and 18% of greenhouse gas emissions measured in CO2 equivalent pending different assumptions. Due to this, carbon footprint labeling has been described as a potential tool to inform consumers about greenhouse gases associated with food products and assist them with the necessary information to purchase products that help reduce greenhouse gas emissions. …

Biological Condition Of Money Pont Benthic Communities, Southern Branch Of The Elizabeth River (2010), Daniel M. Dauer

Elizabeth River Reports

Executive Summary

The subtidal macrobenthic communities off Money Point in the Southern Branch of the Elizabeth River were quantitatively sampled in summer 2011. The designated Money Point study area will be a part of a sediment contaminant remediation effort. The primary objectives of this study were to: (1) characterize the biological health of the benthos of Money Point and (2) produce an historical data base that will allow an assessment of the effectiveness of the proposed sediment contamination remediation efforts with respect to Money Point benthos.

The most quantitative characterization of the benthos of the Elizabeth River watershed was the …

Application Of A Gene-Based Population Dynamics Model To The Optimal Egg Size Problem: Why Do Bivalve Planktotrophic Eggs Vary In Size?, Eric N. Powell, Jason Morson, John M. Klinck

CCPO Publications

The presumption is that egg quality influences larval survival and that egg size influences egg quality. Thus, larger eggs should be favored by selection. Counterweighing the tendency for egg size to increase is the number of eggs that can be produced if egg size remains small. We examine how egg size and egg number counterbalance in Crassostrea oysters, resulting in an average egg size near 50 mu m. Simulations imposing a diversity of ranges in larval survivorship-from little advantage for large eggs relative to small eggs to a great advantage-yield some anticipated outcomes in which genotypes generating larger eggs are …

Diet And Feeding-Related Morphometrics Of The Blackstripe Topminnow, Fundulus Notatus, In Allotropic And Syntopic Populations With The Blackspotted Topminnow, Fundulus Olivaceus, Charles Michael Champagne

Master's Theses

The Fundulus notatus species complex consists of three described species: F. notatus, F. olivaceus and F. euryzonus. Both F. notatus and F. olivaceus have broad overlapping ranges with many populations being found within and outside of contact zones. Contact zones are generally found in midreaches with F. olivaceus dominating headwaters and F. notatus in larger rivers downstream. Both species share similar ecological niches so the mechanism allowing for stable coexistence in contact zones is unknown. The purpose of this study was to examine variability in diet and feeding morphology of F. notatus in syntopic and allotopic populations across …

A Moderational Model Investigating Child Temperament, Executive Functioning, And Contextual Predictors Of Externalizing Behaviors In Preschoolers, Ferne Arlene Pinard

Dissertations

Child externalizing behavioral problems (e.g., ADHD symptoms and aggressive behaviors) often appear early in life, are relatively stable, and are associated with maladaptive outcomes in many domains of functioning. Research has shown that, for a subset of children who demonstrate these early behavioral patterns, the course is often more pervasive and persistent. Consequently, a better understanding of externalizing behavioral problems during the preschool period is essential. The current study examined whether biologically-based correlates (i.e., child temperament and executive functioning/neurocognitive attention; EF/Attention) would moderate the relation between the contextual correlates (i.e., socioeconomic status and parenting practices) and externalizing behaviors (i.e., ADHD …

The Effect Of Prior Experiences And Sequence Of Instruction Upon Preservice Teachers' Pedagogical Beliefs And Mathematical Knowledge For Teaching, Benjamin Sloop

All Dissertations

This study investigated the effects of sequence of instruction in a laboratory-based mathematics content course for elementary teachers on preservice teachers' (PSTs') pedagogical beliefs and Mathematical Knowledge for Teaching (MKT) through a quasi-experimental design in which the order of laboratory tasks and explanations of content was altered between sections for a given unit and between units within a given section. This study also investigated the prior experiences a group of preservice elementary teachers shared as students of mathematics and examined how these experiences related to their beliefs regarding effective pedagogy through a phenomenology. Additionally, the perspective of an experienced instructor, …

Effects Of Origanum Majorana L. On Cadmium Induced Hepatotoxicity And Nephrotoxicity In Albino Rats., Ali A. Shati

Saudi Medical Journal

OBJECTIVES: To evaluate the effect of Origanum majorana L. (OM) against cadmium (Cd)-induced hepatotoxicity and nephrotoxicity. METHODS: This study was performed at King Khalid University, Abha, Kingdom of Saudi Arabia from September to December 2010. Thirty-six male albino rats were divided into 6 groups: control, Cd, OM, OM+Cd, OM pre-treated (received OM extract for 14 days followed by Cd for 14 days), OM post-treated (received Cd for 14 days followed by OM extract for 14 days). All treatments were orally administered once a day (Cd: 5 mg/kg by weight [b.w] and OM: 1 g/kg b.w) for 28 days. Changes in …

The Effects Of Hypothermia On Status Epilepticus-Induced Acquired Epilepsy, Kristin Phillips

Theses and Dissertations

Status epilepticus (SE) is a type of neurological injury characterized by continuous seizure activity and can lead to molecular and pathophysiological alterations leading to plasticity changes. SE can lead to the development of AE by the process of epileptogenesis, which is a phenomenon that describes the transformation of normal brain tissue into a hyperexcitable neuronal population. It has been demonstrated both in vivo and in vitro that calcium (Ca2+) dynamics are severely altered during and after SE, and these changes play a major role in the progression of epileptogenesis. It has also been reported that preventing the rise in intracellular …

Environmental Magnetism Survey Of A Holocene Sedimentary Record From Barilari Bay, Western Antarctic Peninsula, Carl Joseph Natter Jr.

Theses, Dissertations and Culminating Projects

Barilari Bay is located on the western side of the Antarctic Peninsula (AP), opposite the former Larsen B Ice Shelf on the eastern Antarctic Peninsula. Barilari Bay was swath mapped during United States Antarctic Program cruise NBP10-01 as part of the Larsen Ice Shelf System, Antarctic (LARISSA) program. The bay consists of a series of five basins with water depths greater than 600 meters, from which a suite of kasten cores and jumbo piston cores was collected. Three cores, JPC-127, its trigger core TC- 127, and JKC 55 were collected from the outer portion of the Bay and recovered an …

Effects Of Osteopontin Single Nucleotide Polymorphisms On Bull Semen Quality, Chance L. Williams

Graduate Theses and Dissertations

Two groups of bulls were utilized to evaluate if single nucleotide polymorphisms (SNP) in the Bos taurus OPN gene (GenBank accession # AY878328.1) promoter region were related to bull semen quality variables as evaluated by computer assisted semen analysis (CASA). Group 1 consisted of 19 Angus and Balancer bulls, ranging in age from 5 to 8 years, which were collected weekly during a 2-month period (July 15, 2010 through September 19, 2010). Group 2 consisted of 16 Brahman influenced (1/8 to 3/16 Brahman) bulls, mean age = 1.1 ± 0.1 year, that were collected monthly for a 7 month period …

Imagery And Contamination Aversion, Thomas Grover Adams

Graduate Theses and Dissertations

Contamination-based obsessive-compulsive disorder (OCD) is the most common form of OCD. Recent research indicates that the emotion of disgust may play a primary role in the etiology and maintenance in contamination-based OCD (CB-OCD). However, little is known about the effects of disgust on compulsive behaviors related to CB-OCD (e.g.,, hand-washing). The present study utilized an imagery-priming paradigm to test the effects of experienced disgust on compulsive hand-washing. Seventy-eight participants were selected for high or low symptoms of CB-OCD. Following response training, participants were submitted to a disgust or neutral imagery task. Following the imagery task, participants rated their subjective fear …

Coaching For Confidence: An Examination Of The Relationship Between Literacy Coaching And Teacher Efficacy In Middle School English Language Arts Classrooms, Gayle N. White-Wallace

Education Doctoral

The focus of this study was to portray the work of middle school literacy coaches as agents to increase teacher efficacy. Coaches and teachers in New York school districts participated in the study, which attempted to add to the research on teacher efficacy and coaching by authentically examining the experiences and perceptions of coaching. Data was collected using the Ohio State Teacher Efficacy Scale, interviews, focus groups, observations notes, and researcher notes. This study revealed that participating in the coaching experience increased teachers’ self-efficacy and that the teachers valued their literacy coach to provide resources, model lessons, assist with lesson …

The Relationship Between Middle School Students' College-Going Beliefs And Sense Of Belonging In School, Jamie L. Steiner

Education Doctoral

Although there is an abundance of research on middle school counseling, college readiness and belonging, there is a gap in the research regarding middle school students and attempts to correlate their sense of belonging to college-going beliefs. Research identifies eighth grade as a critical time in a student’s education in which they make important post-secondary decisions. The research stressed that a s tudent’s academic achievement was not only influenced by intellectual abilities, but by their school climate. The purpose of this mixed methods study was to identify a correlation between schoolbased factors, specifically a student’s sense of belonging, and college-going …

Sergeants As Leaders: A Case Study Of Transformational Leadership Among First-Line Supervisors In The Police Department, Betty L. Campbell

Education Doctoral

This qualitative research examined the leadership styles and professional development practices of a police department, the reflective experiences of police sergeants as they transition from being patrol officers, and the perception of police sergeants of their career development. Specifically, this study sought to answer the following essential questions: (a) What are the self-reported and observed leadership styles and practices of police sergeants at the Echo Bay police department? (b) To what extent do police sergeants practice the tenants of transformational leadership, and (c) How do police departments develop the leadership competencies of their police sergeants. The researcher used four different …