Digital Commons Network^™

Vitamin D Deficiency And Supplemental Use In Pregnancy: A Systematic Review And Meta-Analysis, Christine Rogers-Kelly

Theses and Dissertations

Vitamin D inadequacy is highly prevalent among pregnant women worldwide. Inadequacy or deficiency of vitamin D can lead to adverse outcomes during pregnancy such as pre-eclampsia, gestational diabetes, and caesarian section. A systematic review and meta-analysis were conducted to examine the effectiveness of vitamin D supplementation on serum vitamin D status during pregnancy in randomized controlled trials (RCTs). A search was conducted in PubMed, Scopus, ProQuest, EBSCO, Cochrane CENTRAL Database of Controlled Clinical Trials, PsycINFO, CINAHL, and Google Scholar, in addition to searching reference lists in published reviews. A comprehensive list of RCTs of vitamin D status and supplemental use …

Spatiotemporal Dynamics Of Multi-Scale Habitat Selection In An Invasive Generalist, Kelsey Elizabeth Paolini

Theses and Dissertations

Spatiotemporal dynamics of resource availability can produce markedly different patterns of landscape utilization which necessitates studying habitat selection across biologically relevant extents. Feral pigs (Sus scrofa) are a prolifically expanding, generalist species and researchers have yet to understand fundamental drivers of space use in agricultural landscapes within the United States. To study multi-scale habitat selection patterns, I deployed 13 GPS collars on feral pigs within the Mississippi Alluvial Valley. I estimated resource selection using mixed-effects models to determine how feral pigs responded to changes in forage availability and incorporated those results with autocorrelated kernel density home range estimates. My results …

The Compounding Stresses Of Tobacco Thrips, Frankliniella Fusca (Hinds), And Reniform Nematode, Rotylenchulus Reniformis (Linford & Oliveira), On The Growth And Development Of Cotton, Gossypium Hirsutum L, Whitney Desiree Crow

Theses and Dissertations

The objectives of this research were to evaluate management options for tobacco thrips, Frankliniella fusca (Hinds), and reniform nematode, Rotylenchulus reniformis (Linford & Oliverira), in cotton productions systems. When evaluating tillage practices for pest control, conservational tillage reduced thrips densities and damage, while the impact on nematode densities is less understood and in this study had no impact. Insecticide seed treatments remain a vital resource for controlling thrips in Mid-South cotton production systems. When incorporating an early season herbicide application for weed control, systems with an insecticide seed treatment generally tolerated herbicide injury better than those with early season stress …

Influence Of Strain And Temperature On Growth, Survival And Biofilm Formation By Listeria Monocytogenes And Salmonella Spp. In High And Low Concentrations Of Catfish Mucus Extract On Four Food-Contact Surfaces And Their Destruction, Nitin Dhowlaghar

Theses and Dissertations

According to USDA-FSIS reports, L. monocytogenes and Salmonella are two important foodborne pathogens that are prevalent throughout catfish environment. Channel catfish (Ictalurus punctatus) is the most important aquaculture species in the United States accounting for more than 60% of its aquaculture production. The objectives of this study were to determine the effect of strain, temperature concentration on the growth, survival and biofilm formation of L. monocytogenes and Salmonella using catfish mucus extract on different food-contact surfaces. Growth and survival of L. monocytogenes and Salmonella was greater at the higher concentration of mucus extract at both 10°C and 22°C. In 15 …

Investigating Effectiveness Of Wild Pig Policy And Legislation In The U.S., Andrew Lane Smith

Theses and Dissertations

The legislative procedures regarding wild pigs in the United States are expanding in scope and priority, however, the uniformity of legislation is entropic at best. Each state addresses the issues of wild pigs differently and treatment is based on a priority of resource concerns. An evaluation was conducted at the national level of federal, state, and local policy with regards to wild pig control. Additionally, successful and unsuccessful legislation is evaluated to determine commonalities in the social, economic, and ecological factors contributing to the success or failure of legislation. Information collected provides state legislatures with sample model legislation that can …

Investigating The Role Of Zinc In The Physiology And Virulence Of Streptococcus Pneumoniae, Lindsey Renae Brown-Burcham

Theses and Dissertations

Homeostasis of trace metal ions is essential for a variety of cellular processes and virulence mechanisms, including resistance to oxidative stress, DNA replication, and regulation of cell adhesion/invasion. Understanding how pathogenic microorganisms overcome metal starvation and intoxication provides insight into how these mechanisms could be targeted by novel antimicrobial therapies. Streptococcus pneumoniae, or pneumococcus, is a Gram-positive, commensal of the human nasopharynx and upper respiratory tract. Though this organism is primarily an asymptomatic colonizer, it is also the causative agent of infections ranging in severity from reoccurring acute otitis media to life-threatening community acquired pneumonia or bacterial sepsis. This study …

Material Characterization Using Laser-Induced Breakdown Spectroscopy, Chet Raj Bhatt

Theses and Dissertations

Laser-induced breakdown spectroscopy (LIBS) has been established as a rapid, in situ, and real-time spectroscopic analytical technique for material characterization. It is very handy for the study of all kinds of materials irrespective of their state. After being used for a Mars mission, LIBS has gained global attention and many scientific researches are investigating its applications. The main objective of this dissertation is to study the possibility of using laser spectroscopic sensing techniques for material characterization and if possible, to develop methodologies. Studying molecular emission spectra for elemental analysis is a relatively new trend in the spectroscopic field. Molecular emission …

Melatonin Implants During Pregnancy On Maternal Hemodynamics And Growth Of Offspring In Beef Cattle, Keelee Jae Mccarty

Theses and Dissertations

Melatonin is a strong antioxidant that has previously been observed to increase uteroplacental blood flow and increase postnatal calf growth when supplemented during gestation. The objective of the current study was to examine the effects of melatonin implants on uterine blood flow and subsequent offspring growth. Commercial beef heifers and cows were artificially inseminated and assigned to one of two treatment groups supplemented with (MEL) or without (CON) melatonin from days 180 to 240 of gestation. Total uterine artery blood flow was increased in MEL- versus CON-treated cattle. Fetal and birth weight were not different between treatments. However, at castration, …

Mixed Used Urea Formaldehyde And Isocyanate Resins For Wood Composites, Ming Liu

Theses and Dissertations

Urea formaldehyde (UF) resins are widely used as adhesives for wood-based composites. These thermosetting polymers have advantages of relative low price, fast curing speed, and relative good bonding performance. However, UF resin bonded composites are designed for interior applications due to its weak water resistance. Moreover, traditional prevalent ways for recycling wood-based composites face problems caused by UF resins. In this project, the reuse of cured UF resins was systematically studied. The verification and characterization of crystalline structures in cured UF resins were conducted. The results showed that the crystalline regions were accounted for nearly 14.48% in a typical 1.2 …

Funny Channel Signaling In Equine Airway Disease, Courtney Hunter

Theses and Dissertations

Traditional animal models of severe asthma do not recapitulate defining asthma characteristics, including persistent airway hyper-responsiveness, and chronic neutrophilic inflammation. This is problematic because moderating airway hyper-responsiveness decreases asthma frequency and severity, making it a paramount pharmacological goal in asthma research. Employing a spontaneous equine asthma model (equine pasture asthma, EPA), we first confirmed reversible airway obstruction in eight diseased horses during asthma exacerbations in response to ß2renergic agonist stimulation. Next, non-specific airway hyper-responsiveness was confirmed using methacholine bronchoprovocation to identify the provocative concentration causing a 40% increase in baseline lung resistance (PC40RL)- a threshold similarly employed in evaluating human …

Hematological And Histopathological Changes Associated With Chronic Diazinon Exposure In Alligator Gar, Atractosteus Spatula, Ahmad Salem Omar Ali

Theses and Dissertations

Extensive use of the organophosphate diazinon has led to its accumulation in aquatic environments and negative effects on fish health. Most studies focus on the effects of short term exposure to high levels of organophosphate pesticides. This research was conducted to assess the effect of chronic sub-lethal exposure to 0, 0.01, and 0.1 mg/L diazinon for 15 and 30 days on blood parameters and histopathological damage in alligator gar, Atractosteus spatula. Fish exposed to either concentration were motionless, produced excess mucous, had lighter skin color, and had skin lesions. Blood indices of red blood cells, leukocytes and hematocrit values significantly …

Identifying Molecular Mechanisms Of Immunomodulation By Staphylococcal Superantigens In Humans, Juyeun Lee

Theses and Dissertations

Superantigens are exotoxins produced by Staphylococcus aureus and induce extensive T cell proliferation and proinflammatory cytokines, leading to toxic shock syndrome at high concentrations. However, the role of superantigens produced at relatively low concentrations during asymptomatic colonization or chronic infection has not been well established. In this dissertation, we demonstrated that stimulation of human PBMCs with staphylococcal enterotoxin C1 (SEC1) at the dose inducing a half maximal T cell proliferation (suboptimal stimulation) induced immunosuppressive CD4+CD25+FOXP3+ and CD8+CD25+FOXP3+ T cells. The suppression of these cells was mainly mediated by the galectin-1. We found that suboptimal stimulation with SEC1 induced differential activation …

Impact Of A Regulatory Threat Toward Agricultural Water Use In The Mississippi Delta: An Experimental Approach, Steven Christopher Wilhelms

Theses and Dissertations

Due to increased adoption of irrigation and advancements in technology, producers in the Mississippi Delta have been unsustainably depleting the water stocks in the Mississippi River Valley Alluvial Aquifer (MRVAA). This research investigates the impacts of various regulatory threats uniformly applied to heterogeneously located producers to avert further overexploitation of the MRVAA. If a regulatory threat successfully incentivizes reduction of producers’ extraction rates, costly implementation of a binding limited-use regulation could be avoided. Laboratory experiments incorporating the major characteristics of the MRVAA were conducted to test two threatened uniform policies, limited-use and moratorium. The main finding of the research is …

Evaluation Of Kudzu Bug As A Pest In Mississippi Soybean Production Systems, William Michael Mcright

Theses and Dissertations

The kudzu bug is an invasive species to the United States, and it has recently become a problem in the southern U.S. Experiments were conducted to examine the potential damage to vegetative stage soybean, with findings suggesting that kudzu bugs pose little threat to vegetative stage soybean in Mississippi soybean production systems. Foliar insecticides are an effective option for management of kudzu bug, however, neonicotinoid seed treatments are not recommended as an effective management strategy. Kudzu bug population densities of nymphs peaked in early August in soybean, and adult densities peaked in late September. This project was designed to develop …

Evaluation Of Soybean Production Practices That Impact Yield Losses From Simulated Insect Defoliation, Benjamin Carroll Thrash

Theses and Dissertations

Soybean, Glycine max (L.) Merr., is planted across a vast amount of land in the Mid-Southern U.S. (Arkansas, Louisiana, Mississippi, and Tennessee), and yield responses to defoliation can vary. Experiments were conducted during 2015-2017 evaluating how soybean yield responds to multiple and continuous defoliation, as well as planting date and plant population. Multiple defoliation events were evaluated by defoliating soybean at varying levels at V3, V6, and both growth stages. There was no interaction between defoliation occurring at V3 and V6 growth stages, indicating that the impact of each defoliation event was independent of the other. The effect of continuous …

A New Perspective On Giving-Up Density Experiments And The Landscape Of Fear, Jordan D. Mcmahon

Theses and Dissertations

Non-consumptive effects that predators have on prey are important to ecosystems. The perceived risk of predation can alter feeding behavior. Giving-up density (GUD) experiments have been a foundational method to evaluate perceived predation risk, but rely on the assumption that food preferences are absolute. However, nutritional preferences are context dependent and can change with risk. In my first chapter, I used spiders and grasshoppers to test the hypothesis that covariance in nutritional preferences and risk may confound the interpretation of GUD experiments. My results demonstrate that predation risk and nutritional preferences covary and can confound interpretation of GUD experiments. In …

Assessment Of The Socio-Environmental Impacts Of The Urban Expansion Using Gis And Remote Sensing In The City Of Guayaquil, Ecuador., Erika P. Jimenez Rivera

Theses and Dissertations

This thesis investigates the impacts of the urban expansion from 1990 to 2010 in Guayaquil, Ecuador using geospatial technologies. It incorporates census and land cover data to identify the social and environmental repercussions through Hot Spot Analysis, land cover classification, and Markov chains model.

It's A Drag: Finding The Divine In Drag Performance, Richard Andrew Curtiss

Theses and Dissertations

For over the thirty years, drag performance has been examined for its utility to subvert or reinforce traditional gender roles. Many of these examinations have focused on performances that emphasize subversion and separated drag into two categories: the progressive drag that subverts, and the regressive drag that reinforces. While this approach has provided a wealth of understanding about drag performance and gender roles, drag can be examined without separating its subverting/reinforcing aspects. If drag is seen as the consideration of a given gender performing the not given gender, then another consideration can be made to the subverting performing the reinforcing. …

Microbial And Co2 Responses To Water Stresses Show Decreased Productivity And Diversity Through Time, David Michael Robinson

Theses and Dissertations

Some bacterial taxa when stimulated by water additions will break dormancy, grow, and become dominant members of the community and contribute significant pulses of CO₂ associated with the rewetting event. These pulses of activity are associated with high levels of bacterial productivity in soils. (Aanderud et al. 2011) We examined the bacterial taxa that resuscitate and become metabolically active following two forms of water stress (soil drying-rewetting and freeze-thaw cycles) and we captured and measured the CO₂ emanating from those soils. Specifically, We used target metagenomics, which uses a specific gene pool within bacteria that is associated with …

Design Of A Low-Cost Capillary Electrophoresis Laser-Induced Fluorescence System: Lessons Learned When Trying To Build The Lowest Possible Cost System, Steven James Perry

Theses and Dissertations

Capillary electrophoresis laser-induced fluorescence (CE-LIF) is widely used to detect both the presence and concentration of fluorescently labeled biomolecules. In CE-LIF, a plug of sample fluid is electrophoretically driven down a microchannel using a high voltage applied between the opposite ends of the microchannel. Molecules of different sizes and charge states travel at different velocities down the channel. Laser light with a wavelength in the excitation band of the fluorophores is focused near the end of the channel. As each species of molecule passes through the laser spot, the fluorophores emit a fluorescence signal which is measured with an optical …

Synthesis And Cytotoxicity Of Azaheterocyclic Compounds, Keyur M. Pandya

Theses and Dissertations

Multicomponent coupling reactions (MCRs) have been known for a long time and one such reaction that utilizes isocyanides is Passerini reaction. It is a powerful tool to synthesize libraries of different compounds. Azaheterocyclic compounds play an important role in medicinal chemistry. Motifs such as imidazoles, piperazines, pyrazoles, pyridines, triazoles, etc. are routinely observed in several compounds of pharmacological interest. Several natural products also contain these motifs in them. We have undertaken a library synthesis of heterocyclic molecules driven by our group's long-standing interest of synthesizing medicinally relevant small molecules employing green chemistry techniques.

This thesis details our efforts on the …

Design And Development Of Inquiry-Based Materials For Conducting Observational Astronomy Research At Utrgv, Americo Francisco Hinojosa Lee

Theses and Dissertations

The purpose of this work is to develop instructional materials to enhance the expertise of students in conducting observational astronomy research. The designed instructional units aim to provide students with an adequate knowledge of astronomy and hone their skills necessary in conducting observations, collecting and analyzing data including processing of astronomical images.

The instructional design is anchored on the ADDIE model (Analyze, Design, Develop, Implement and Evaluate). The phases from ADDIE were used as a framework to accomplish the process of developing the instructional materials. After following the ADDIE, it was possible to define performance goals and tasks which were …

Design Of A Multidirectional Wear Testing Device For Simulating Wear Of Biocompatible Materials Used In Joint Implants, Carlos A. Rodriguez Betancourth

Theses and Dissertations

In the present work, a novel multidirectional pin-on-disc wear testing device designated CNC-POD (computer-numerical-control pin-on-disc) capable of replicating the cross-shear motions experienced by a prosthesis in vivo was designed and developed in the UTRGV in order to evaluate the wear resistance of new biomaterials. The CNC-POD consists of six temperature-controlled pin-on-disc stations mounted on a two-axis CNC table (X-Y). Each pin-on-disc station is load-programmable up to 510 Newtons (115 pounds). The CNC table allows the machine to reproduce a wide range of 2D patterns in millimeter scale on the six stations under a specific load. Friction force is measured during …

Pollen Grains Recognition Based On Computer Vision Methods, Amar Idrees Daood

Theses and Dissertations

The classification of pollen grains is a main task in many disciplines including ecology, forensic sciences, allergy control, and oil exploration. In these application areas, visual inspection is the common method used for classifying pollen. However, recognition by visual inspection consumes much time and effort. Even though some level of automation exists, the automatic recognition of pollen grains remains an open problem. Current pollen-classification solutions rely on measurements of visual cues such as contour or texture. However, these features do not capture the visual complexity of information needed for discriminating among various species of pollen, especially when both a large-scale …

Spatial And Temporal Trends In Diet For Pinfish (Lagodon Rhomboides) From Turtle Grass (Thalassia Testudinum) Beds With Contrasting Environmental Regimes In The Lower Laguna Madre, Texas, Maximiliano Barbosa

Theses and Dissertations

Seagrass meadows in far South Texas are dominated by turtle grass (Thalassia testudinum), and juvenile pinfish (Lagodon rhomboides) are abundant grazers of seagrass epifauna. As they grow, pinfish exhibit an ontogenetic dietary shift and begin consuming increasing amounts of plant material. In this study, contrasting environmental regimes in two seagrass meadows were examined to identify how they might affect pinfish diets, diet shifts, and growth across the growing season. The eastern site was sheltered from prevailing southeasterly winds by a barrier island, while the western site was shallower and subjected to higher wind energy and turbidity. …

Metabolic Dysregulation: An Investigation Of The Role Of Foxo3 In Gluconeogensis In Pten-Null Glioblastomas, Victor Fanniel

Theses and Dissertations

Many processes are regulated by the Phosphatidylinositol 3 kinase (PI3K) pathway in the cell including cell survival, metabolism, and apoptosis. Increased activation of the PI3K pathway is a hallmark of many cancers which can be oftentimes attributed to the mutation of PTEN, which encodes an enzyme that performs the reverse reaction of PI3K. When PTEN is null-mutated, this creates a constitutively active PI3K pathway and constitutively active AKT. Since AKT phosphorylates conserved residues on FOXO transcription factors to mark them for nuclear export, this renders FOXO inactive. However, new research has provided evidence that FOXO is still present in …

Mexican American Counselor And Client: Perceptions Toward Substance Use Disorders, Eluterio Blanco Jr.

Theses and Dissertations

Over 28.6 million Americans have admitted to the ongoing use of illicit drugs and more than half of Americans are current alcohol drinkers yet a significant number of these people do not seek treatment. Trends regarding substance-related treatment have shown Hispanic drug users tend to underutilize drug and alcohol services and treatment avoidance is especially prevalent among Mexican Americans who reside along the US-Mexico border, due in part to the stigma associated with substance use. In addition, counselor attitudes as well as student counselors-in-training attitudes are showing a manifestation of the same kind of stigma toward substance use as the …

Regional Distribution, Non-Invasive Detection, And Genetic Diversity Of The Black-Spotted Newt (Notophthalmus Meridionalis), Evan A. Bare

Theses and Dissertations

The Black-spotted Newt (Notophthalmus meridionalis ) is one of three a salamander species native to Gulf Coast prairies of Texas and Mexico, with respective state and federal protections. This species has been neglected by the scientific community despite concerns of dramatic population declines and a globally endangered status, with the most recent work being conducted in the early 1990’s going unpublished. This study presents the most recent examination of the species providing probabilistic distribution maps, descriptions of three novel populations, assessments of surveying techniques, and the first known examination of intrapopulation genetics including the first documented genetic examination of …

Exploring Experienced Educators' Perspectives On Teacher Professional Development: Potential Implications For English Language Learners, Mary Mann Endress

Theses and Dissertations

Growth in the ELL student population triggers a need for more educators equipped to address the academic and linguistic needs of this growing population. Through a phenomenological case study, this dissertation addresses the following over-arching research question, "What can be learned about the implementation of professional development for teachers of ELLs from the reflections and experiences of former ESL/Bilingual educators?" This dissertation provides a look at PD through the reflective lenses of retired educators who worked directly with ELLs and teachers of ELLs. Data were collected from a questionnaire, interviews and a focus group describes how participants. Through their stories …

Cultural Awareness: Latinos Perceptions In A Multicultural Counseling Course [Concientización Cultural: Percepciones De Estudiantes Latinos En Un Curso De Consejería Multicultural], Leila Flores-Torres

Theses and Dissertations

This study explored the experiences and perceptions from a multicultural counseling course of Latino graduate counseling students at a Hispanic Serving Institution (HSI). The purpose of the study was to understand the students’ lived experience and its impact in developing their multicultural counselor identity and competencies. The research questions included the following: What course experiences and personal values do Latino graduate students identify as relevant to their multicultural counseling preparation? What psychological process do Latino graduate students use to make meaning of their experiences and values in their multicultural counseling preparation to serve the needs of culturally diverse clients?

The …