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The Effect Of Aerobic Exercise Versus Inactivity On Nitric Oxide Concentration And Synthesis In An Elderly Population, Samantha Burton

Theses and Dissertations

CONTEXT: Nitric Oxide (NO) is an endothelial-derived vasoactive molecule that causes an increase in blood flow and oxygen delivery to tissue. A reduction in NO bioavailability has been found to occur in adults over the age of 60 and can be reversed pharmacologically by improving NO synthase (NOS) activity. Reversing these age-related changes with alternative interventions, such as aerobic exercise, has shown some promising results. OBJECTIVE: To quantify blood NO-bioavailability (as measured by blood nitrite levels) in a population of aerobically trained elderly men and compare these data to a group of age-matched, inactive individuals. In addition, we measured the …

Water Use Of Four Commonly Planted Landscape Tree Species In A Semi-Arid Suburban Environment, Michael Cameron Bunnell

Theses and Dissertations

Native plant communities and agricultural land are commonly converted to urban areas as cities across the Western United States continue to grow and expand. This expansion is typically accompanied by afforestation where a common goal among communities is to maximize shade tree composition. Planted forests in these regions are commonly composed of introduced tree species native to mesic environments and their ability to persist is dependent on consistent irrigation inputs. Many potential ecosystem services may be derived from planting trees in urban and suburban areas; however, there are also costs associated with extensive afforestation, and shade tree cover may have …

Virulence Of Photorhabdus Spp.: Examining The Roles Of Environment, Evolution, And Genetics In Insect Mortality, Dana Blackburn

Theses and Dissertations

Entomopathogenic nematodes (EPNs) (genera Heterorhabditis and Steinernema) kill their invertebrate hosts with the aid of a mutualistic bacterium. The bacteria (Xenorhabdus spp. for steinernematids and Photorhabdus spp. for heterorhabditids) are primarily responsible for killing the host and providing the nematodes with nutrition and defense against secondary invaders. Photorhabdus is a Gram-negative bacterium in the Enterobacteriaceae family with high virulence towards their insect hosts. To achieve high mortality rates Photorhabdus produces a variety of virulence factors such as toxins, lipases, proteases, secretion systems, and fimbriae. EPNs are amenable to laboratory rearing and mass production for biocontrol applications against insects …

Hand-Portable Capillary Liquid Chromatography Instrumentation, Sonika Sharma

Theses and Dissertations

This dissertation focuses on the development of hand-portable capillary liquid chromatography (LC) instrumentation. In this work, battery-operable nano-flow pumping systems (isocratic and gradient) were developed and integrated with portable UV-absorption detectors for capillary LC. The systems were reduced in size to acceptable weights and power usage for field operation. A major advantage of the pumps is that they do not employ a splitter, since they were specifically designed for capillary column use, thereby greatly reducing solvent consumption and waste generation. UV-absorption detectors were specifically designed and optimized for on-column detection to minimize extra-column band broadening. Initially, an isocratic nano-flow pumping …

Maternal Denning Phenology And Substrate Selection Of Polar Bears (Ursus Maritimus) In The Southern Beaufort And Chukchi Seas, Jay Wesley Olson

Theses and Dissertations

Loss of sea ice due to global warming may affect the phenology and distribution of polar bear (Ursus maritimus) denning by altering access to denning habitats. We examined trends in the selection of maternal denning substrate (land versus sea-ice denning) in the southern Beaufort Sea (SB), addressing the potential influence of summer land-use and fall sea-ice conditions on substrate selection. We developed an algorithm based on statistical process control methods to remotely identify denning bears and estimate denning phenology from temperature sensor data collected on collars deployed 1985–2013 in the SB and Chukchi Sea (CS). We evaluated cub …

Mountain Big Sagebrush (Artemisia Tridentata Ssp Vaseyana) Seed Production, Melissa L. Landeen

Theses and Dissertations

Big sagebrush (Artemisia tridentata Nutt.) is the most widespread and common shrub in the sagebrush biome of western North America. Of the three most common subspecies of big sagebrush (Artemisia tridentata), mountain big sagebrush (ssp. vaseyana; MBS) is the most resilient to disturbance, but still requires favorable climactic conditions and a viable post-fire seedbank for successful unassisted recovery. This study was designed to assess MBS seed production throughout post-fire recovery. We performed 2 pilot studies to develop methods for estimating seed production and plant age. The results of the pilot studies and a space-for-time substitution strategy were used to measure …

Advanced Data Analysis Tools And Multi-Instrument Material Characterization, Bhupinder Singh

Theses and Dissertations

My dissertation focuses on (i) the development of new analysis tools and methodologies for analyzing X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) data, and (ii) the comprehensive characterization of materials (nanodiamonds) using a multi-instrument approach. Chapter 1 contains (i) a discussion of the two techniques I focused on most in my work: XPS and ToF-SIMS, (ii) a discussion of the common chemometrics techniques used to analyze data from these methods, and (iii) the advantages/rationale behind the multi-instrument characterization of materials. Chapter 2 describes various good practices for obtaining reasonable peak fits in XPS, which can also …

Gene Networks Involved In Competitive Root Colonization And Nodulation In The Sinorhizobium Meliloti-Medicago Truncatula Symbiosis, Ryan D. Vanyperen

Theses and Dissertations

The rhizobia-legume symbiosis is the most agriculturally significant source of naturally fixed nitrogen, accounting for almost 25% of all biologically available nitrogen. Rhizobia-legume compatibility restrictions impose limits on symbiotic nitrogen fixation. In many cases, the molecular basis for symbiotic compatibility is not fully understood. The signals required for establishing a symbiotic partnership between nitrogen-fixing bacteria (e.g. Sinorhizobium meliloti) and leguminous plants (e.g. Medicago truncatula) have been partially characterized at the molecular level. The first stage of successful root colonization is competitive occupation of the rhizosphere (which is poorly understood). Here, the bacteria introduce themselves as potential symbiotic partners …

Validating Side Scan Sonar As A Fish Survey Tool, Michael A. Bollinger

Theses and Dissertations

Hydroacoustic methods can be used to answer a variety of questions regarding fish populations and behavior. In this study, side scan sonar methodology was developed to quantify abundance and biomass and compared to established visual observation methods on SCUBA over artificial reef structures in the western Gulf of Mexico. Side scan sonar methods were equivalent to SCUBA surveys for measuring fish abundance over the same reef areas, however, abundances were significantly higher when the larger area sampled by side scan was utilized. Side scan sonar methods were also more time efficient than SCUBA, ROV and long line fishing methods (66.7%, …

Molecular Modeling And Mutational Mapping Of The Gpr119 Binding Site, Shane M. Askar

Theses and Dissertations

GPR119 receptor’s biological role in regulating glucose homeostasis has been studied extensively. Results in the scientific literature indicate that, when activated, GPR119 releases insulin in a glucose dependent manner. Currently the 3D structure of GPR119 has not been resolved.

The goal of this research is to use a combination of homology modeling and ligand docking studies to predict the binding mode of GPR119 ligands. Amino acids implicated to have direct interactions with docked ligands will further be assessed experimentally for their roll in binding and activation of GPR119. Our results indicate that residues W2656.48 and R813.28 are likely to be …

Examination Of The Chagas Disease Vector, Triatoma Gerstackeri, In The Lower Rio Grande Valley, Alfredo Flores

Theses and Dissertations

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, which is carried by an insect vector of the family Reduviidae, and of the subfamily Triatomina. The species Triatoma gerstaeckeri is identified as the primary vector of T. cruzi within the Rio Grande Valley. Species of Triatoma gerstaeckeri were trapped in La Sal del Rey National Refuge in 2012 and 2013.

Data indicates a seasonal dispersal pattern of activity for T. gerstaeckeri. Optimal time of capture was between 1-2 hours after sunset. Different methods were utilized to determine the best combination of lures. Results indicate that the UV-light alone is …

Decomposition And Nitrogen Dynamics Of Turtle Grass (Thalassia Testudinum) In A Subtropical Estuarine System, Monica Delgado

Theses and Dissertations

Seagrass beds are pivotal in the functioning of coastal ecosystems in terms of productivity, organic matter turnover and nutrient cycling. Aiming to document decay and nitrogen (N) dynamics of turtle grass (Thalassia testudinum) in a subtropical estuarine system, decomposition patterns of leaves and rhizomes were characterized and compared. Nitrogen usage during decomposition of tissues, and of live tissues and epiphytes growing on live leaves, was also quantified and compared. Stable isotope ratios allowed tracing N within the seagrass bed, following N incorporation into seagrass tissues from the surrounding media (water, sediment). Leaves had a higher N content and decomposed at …

Activation Of Microglia In The Rotenone Lymnaea Stagnalis Model Of Parkinson's Disease, Xiomara Galvan

Theses and Dissertations

Parkinson’s disease (PD) is the most common irreversible neurodegenerative movement disorder affecting approximately ten million people worldwide. In the central nervous system (CNS), PD is known by the selective loss of Dopamine (DA) cells of the substantia nigra pars compacta. Although the disease has been very widely studied, the underlying mechanisms are not yet understood. Several hypotheses have arisen as result of injury of the mitochondria, some experiments include microglia activation, microtubule damage, and reactive oxidative species, which all result in the death of DA cells. The theory of microglia activation upon inflammation was explored in this study. Using the …

A Handcrafted Multi-Branch Nerve Scaffold For In Vivo Peripheral Nerve Regeneration, Ridwan Fayaz Hossain

Theses and Dissertations

Arm and leg peripheral nerve injuries contribute largely to functional disability. These injuries seldom affect a single-line nerve; rather the injury goes beyond and disrupts the nerve tissue across multiple nerve paths. Here we investigate handcrafted PDMS based multi-branch nerve guidance conduit, which addresses this crucial branching from the sciatic nerve to aid with the regeneration to their appropriate distal targets. The design concept of the developed multiple branch nerve scaffolds is not specific for the sciatic nerve but can be modified for general use of all peripheral nerves and additional applications. Microchannels are also fabricated into a device in …

Balanus Eburneus (Crustacea: Cirripedia) As A Potential Indicator Of Estuarine System Recovery In South Texas: A Study Of Recruitment, Growth And Stable Isotopes, Crystal Martinez

Theses and Dissertations

Population characteristics of the barnacle Balanus eburneus were analyzed with the purpose of exploring its potential use as a discriminating indicator among sites exhibiting different disturbances or stages of recovery. The study was conducted from May 2012 to May 2013 at four estuaries in the Lower Laguna Madre, TX including a) Bahia Grande, currently under restoration and divided into Bahia Grande North and Bahia Grande South, b) San Martin Lake, which receives runoff water and c) South Bay, a relatively undisturbed reference estuary. In general, similar barnacle recruitment and growth trends in Bahia Grande South and South Bay were explained …

The Effect Of A Writing Course On The English Language Arts State Assessment Examination In A South Texas High School, Esmeralda V. Munoz

Theses and Dissertations

The purpose of this study is to analyze the impact a writing course will have on test scores for At-Risk students who are taking the English I and/or English II State of Texas Assessment of Academic Readiness End-of-Course exam. The group analyzed was comprised of 2nd and 3rd year cohort students.

Influence Of Property School Wealth On Fifth Grade Student Achievement In Reading And Mathematics, Jesus R. Reyna

Theses and Dissertations

The purpose of this study was to investigate whether, or to what extent, property wealth of the upper and lower 5% districts, per pupil expenditure, limited English proficient students, economically disadvantaged students, membership, and teacher experience contribute to student achievement in 5th grade reading and mathematics. To do this, the fifth grade reading and math achievement scores, based on the TAKS Assessments, to represent student achievement were evaluated against district wealth, per pupil expenditure, economic disadvantage, limited English language proficiency, membership, and years of teaching experience of teachers for the years 2009, 2010, and 2011. A combination of descriptive statistics, …

My True Father, David Rice

Theses and Dissertations

My True Father is novel about a Mexican American family in South Texas going through a divorce.

Evaluating Long-Term Land Cover Changes For Malheur Lake, Oregon Using Envi And Arcgis, Ryan Joseph Woods

Theses and Dissertations

Land cover change over time can be a useful indicator of variations in a watershed, such as the patterns of drought in an area. I present a case study using remotely sensed images from Landsat satellites for over a 30-year period to generate classifications representing land cover categories, which I use to quantify land cover change in the watershed areas that contribute to Malheur, Mud, and Harney Lakes. I selected images, about every 4 to 6 years from late June to late July, in an attempt to capture the peak vegetation growth and to avoid cloud cover. Complete coverage of …

New Genres In The Art Classroom: Shifting Ideas And Identities, Alyssa Grant Ridge

Theses and Dissertations

Secondary art education programs primarily offer courses in traditional mediums like drawing, painting, sculpture, and ceramics. In addition to valuing these traditional art forms, art education research supports integrating new technologies and media in the classroom. However, the possibilities of creating an exclusively contemporary, new genres curriculum have yet to be explored. This study examines the affordances and limitations of a high school-level new genre curriculum and describes how students reacted to these new genres and how their perceptions of art, student-peer relationships, and artist identities changed over time. By introducing students to new genres, the author found students expanded …

Diversification And Speciation Across Sundaland And The Philippines: The Effects Of 30 Million Years Of Eustatic Flux, Luke J. Welton

Theses and Dissertations

I highlight two squamate lineages endemic to Southeast Asia, the Asian water monitors (Varanus salvator Complex) and the Angle-headed lizards (Agamidae: Gonocephalus), and elucidate their systematic affinities and historical biogeography. My results represent novel phylogenetic inferences, with biogeographic histories and diversification events corresponding to major climatic fluctuations over the past 30 million years. Additionally, I solidify the taxonomy and systematics of the Varanus salvator Complex, and enumerate more than a dozen Gonocephalus lineages as candidate species in need of taxonomic scrutiny. Lastly, I investigate contemporary and historical patterns of dispersal throughout Sundaland, and between Sundaland and the Philippines.

Comparing Reproductive Capacity Of Nearshore And Offshore Red Snapper, Lutjanus Campechanus, On Artificial Reefs In The Western Gulf Of Mexico, Ricky J. Alexander

Theses and Dissertations

Red snapper collected quarterly from four artificial reefs in south Texas were examined to compare total length, total weight, age, and the proportion of male to female red snapper, calculate gonadosomatic index values, batch fecundity, annual spawning frequency, and annual fecundity, and estimate size and age at maturity. Spawning occurred from April to September, with most active spawning observed in June (58%). Despite larger red snapper producing more eggs, and fish being larger offshore, most active spawning (68%) and egg production (74%) was observed nearshore. Female red snapper reached 50% maturity (L50) between 350-550 mm, and L75 by 600 mm. …

Protecting Professional Football: A Case Study Of Crisis Communication Tactics Demonstrated During The Concussion Crisis By The National Football League And The Introduction Of Cultural Ingrainment As A Component In Crisis Communications Models, Jordan Todd Mower

Theses and Dissertations

This research analyzes the crisis communications tactics employed by the National Football League at key points during the concussion crisis in relation to strategies recommended by models based on image restoration theory and situational crisis communications theory. The discrepancies between the NFL's tactics and recommended situational tactics, viewed in light of the financial and market increases for the league over the duration of the crisis, show the need for an additional component in accepted crisis communications models. Cultural ingrainment is posited as a component to be added to present models as a mitigating factor of organizational harm in cases of …

Reject Or Redemptive Fathers? A Content Analysis Of Father Portrayals In Top Box Office Family Films, Cassidy Jo Wadsworth

Theses and Dissertations

More research is needed to fully understand the way in which parents, particularly fathers, are portrayed in family films and the effects those portrayals might have. Viewers, particularly parents, need to understand how the material their children view presents reality and how it may shape their children's perspectives of the real world, particularly where the family unit and parenting role are concerned. By exploring these portrayals through the lens of Cultivation Theory, this study sought to answer this overarching question: How are fathers portrayed in family films as opposed to television? This quantitative study explores the top twenty films from …

A Longitudinal Examination Of The Effects Of Acculturation And Mental Health Problems On Immigrant Father Involvement: A Cross-Cultural Study, Keitaro Yoshida

Theses and Dissertations

The present study examined how acculturation, mental health problems, and parenting stress are associated with two dimensions of father involvement longitudinally for Latino and Chinese immigrant fathers using a nationally representative sample of young children and their resident fathers from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B). After controlling for a variety of individual and demographic characteristics and previous levels of father involvement, results from multiple group structural equation modeling revealed that immigrant fathers' English proficiency is negatively associated with care-taking involvement at 2 years, but positively associated with care-taking involvement at 4 years. Interestingly, mothers' English proficiency is also …

Blockade Of Tgf-Ss Signaling Through The Activin Type Iib Receptor With The Small Molecule, Sgi-1252, Jordan David Fuqua

Theses and Dissertations

Antagonism of the activin receptor signaling pathway represents a promising potential therapy for the muscular dystrophies and other muscle wasting disorders (i.e., cachexia or sarcopenia). Previous research has shown that antagonism of activin signaling promotes muscle growth, attenuates muscle wasting, and restores function in both wild type and diseased animals. Our laboratory has recently developed a novel small molecule (SGI-1252) that inhibits activin downstream (i.e., Smad2/3 phosphorylation) signaling. Purpose: In this study we determined how eight weeks of orally administered SGI-1252 affected TGF-ß signaling, whole body mass, individual limb muscle mass, and muscle fiber cross sectional area (CSA). Methods: Wild-type …

Evaluation Of Breastfeeding Curricula In Didactic Programs In Dietetics And Dietetic Internships Across The United States, Maria Diane Swiss

Theses and Dissertations

Background: Breastfeeding is known to have many benefits for both mothers and infants. With the Surgeon General's Call to Action to Support Breastfeeding, health professionals have increased their attention on breastfeeding competency. Objectives: This study aimed to evaluate breastfeeding curricula that are currently being covered in didactic programs in dietetics (DPDs) and dietetic internships (DIs) across the United States. Methods: Two-part surveys were sent to all directors of DPDs and DIs (n=475) with instructions to forward the second portion of the survey to instructors of classes that taught about breastfeeding. Qualtrics software was used for data …

Galvanic Corrosion Of Magnesium Coupled To Steel At High Cathode-To-Anode Area Ratios, Dila Ram Banjade

Theses and Dissertations

In this study, the impact of galvanic coupling of magnesium to steel on the corrosion rate, surface morphology, and surface film formation was investigated. In particular, the role of self-corrosion was quantified as previous studies showed discrepancies between model predictions and experimental results that were likely due to significant self-corrosion. This experimental study examined the corrosion of Mg coupled to steel in 5 wt% NaCl at cathode-to-anode area ratios that ranged from 5 to 27. Results showed that self-corrosion was significant and accounted for, on average, one-third of total corrosion. Moreover, self-corrosion varied with time and cathode size, and was …

Instrumental Music Participation And The Differences In Academic Performances For Students In Poverty, Shawn A. Oban

Theses and Dissertations

Because of the emphasis on No Child Left Behind and high stakes testing, school districts and administrators have been limiting or eliminating fine arts courses from an already shrinking curriculum, focusing on the subjects being tested. Students living in poverty are often entering formal schooling behind academically.

The researcher examined longitudinal test data from 2010-2015 from middle school aged students in a large Midwest school district. The researcher focused on test scores from the sixth grade when instrumental music was offered, examined test data from tenth grade, and studied academic growth. All student scores were included, but the independent variables …

Review Of Aviation Research: A Content Analysis Of Articles Published In The Collegiate Aviation Review, 2007–2012, Safak Aktemur

Theses and Dissertations

The purpose of the study was to conduct a content analysis of the methodological quality of articles published in the Collegiate Aviation Review (CAR)” a refereed journal of the University Aviation Alliance (UAA)”to determine if actual practices of aviation researchers were consistent with commonly recommended research methods and procedures. The accessible population consisted of the 76 articles published in CAR between 2007 and 2012 (Volumes 25“30). The sample consisted of N = 69 articles and excluded literature reviews, meta-analyses, studies that described the development or validation of an instrument, philosophical inquiries, position papers, or historical studies. The analysis focused on …