Digital Commons Network^™

Development Of A Cyberinfrastructure For Assessment Of The Lower Rio Grande Valley North And Central Watersheds Characteristics, Linda Isabel Navarro Navarro

Theses and Dissertations

Due to an increase in urbanization in the Lower Rio Grande Valley (LRGV), there have been substantial modifications to hydrology causing a decline in water quality to the Laguna Madre watershed. The major concern is the inflow of freshwater from the North and Central waterways released to the Lower Laguna Madre which is designated as an impaired watershed for high concentrations of bacteria and low dissolved oxygen. The objective of this study is to perform a watershed characterization to determine potential pollution sources of each watershed by developing a cyberinfrastructure and collect a wide inventory of data. The objective will …

Study Of Particle Size Effect On The Performance Of Tio2 Nanoparticles As Lubricant Additives On Vegetable Oil-Based Nanolubricants, Dario F. Rodriguez

Theses and Dissertations

Recently there has been an increase in concern regarding the use of petroleum-based lubricants. This has created an interest in readily available biodegradable lubricants such as vegetable oils. This work evaluates the rheological and tribological performance of grapeseed, and sunflower oils altered with 5, 18, and 40 nanometer titanium dioxide (TiO2) nanoparticles at differing concentrations. Block-on-ring tests were performed using the ASTM G-077-05 standard procedure. The effect of nanoparticle size and concentration and shear rate on the viscosity were evaluated and the experimental data was compared to conventional models. Roughness tests were performed on the wear scar of the blocks …

Determining The Effectiveness Of Wildlife Exits Along A South Texas Highway, Zarina N. Sheikh

Theses and Dissertations

Movement is a key component of survival for many species, often causing wildlife to cross heavily trafficked highways, resulting in road mortalities. In Cameron County, Texas, ten wildlife exits (WE) were installed along State Highway 100 in conjunction with existing mitigation structures to provide species such as the U.S. endangered ocelot with a safe option to escape the right-of-way (ROW). The objectives of this study were to determine effectiveness and species usage, as well as to estimate the percentage of wildlife that crossed back into the habitat via a WE. Results of this study showed that all six target species …

Optimality Of Delaunay Triangulations, Estefania A. Sierra

Theses and Dissertations

In this paper, we begin by defining and examining the properties of a Voronoi diagram and extend it to its dual, the Delaunay triangulations. We explore the algorithms that construct such structures. Furthermore, we define several optimal functionals and criterions on the set of all triangulations of points in Rd that achieve their minimum on the Delaunay triangulation. We found a new result and proved that Delaunay triangulation has lexicographically the least circumradii sequence. We discuss the CircumRadii-Area (CRA) conjecture that the circumradii raised to the power of alpha times the area of the triangulation holds true for all α …

Development And Characterization Of Nanofiber-Based Thermoelectric And Piezoelectric Composites, Julio Enrique Trevino

Theses and Dissertations

This study focuses on the development and characterization of nanofiber-based composites with the goal of developing flexible, lightweight, and cost effective thermoelectric and piezoelectric devices. The following materials were used in the development of the composites: polyvinylidene fluoride (PVDF) with polyaniline (PANI), polypyrrole (PPY), polyindole (PIN), polyanthranilic acid (PANA), polycarbazole (PCZ), polyacrylonitrile (PAN), functionalized multi-walled carbon nanotubes (MWCNT-COOH), and camphorsulfonic acid (CSA). Blends and in-situ polymerization techniques were utilized to increase the desired thermoelectric/piezoelectric response. Nanofiber systems were produced utilizing the Forcespinning® technique. The morphology, structure, electrochemical, thermal stability, thermoelectric, and piezoelectric performance was analyzed. All of the nanofiber PVDF/CP …

Impact Of Antecedent Wetness And Rainfall Spatial Variability On Design Floods, Rachael Nicole Mcmahon

Theses and Dissertations

In the absence of long hydrologic records, water engineering design application rely primarily on the concept of design storms and subsequently design floods. However, despite the long-lasting use of these approaches there are several aspects that merit careful consideration and possibly revision. Representation of spatial variability of rainfall extremes in design storms has relied primarily on the use of area reduction factors that while useful, they do not represent realistic patterns of flood inducing storms. Furthermore, the impact of antecedent wetness on the transformation of design storms to design floods is often neglected. In this work we carry out a …

Practical Challenges Of Using Sunn Hemp As A Cover Crop In The Lower Rio Grande Valley, Qulina Rai

Theses and Dissertations

Sunn hemp (Crotalaria junceae) is an emerging cover crop with many reported benefits such as nitrogen fixation, carbon sequestration, and suppression of weeds and nematodes. Relatively little is known about appropriate ways to inoculate sunn hemp ensuring nitrogen fixation, and diseases that affect sunn hemp within the Lower Rio Grande Valley of Texas.

Four sticking agents, peanut oil, jaggery, gum arabic, and water used to aid inoculation of Bradyrhizobium japonicum in sunn hemp was checked on nodulation. Water treatment was least effective. Peanut oil and jaggery treatment showed better performance in overall total nodules, and active nodules. Gum …

Pattern Based Classification Of Chronic Kidney Disease Patients, Melissa Megan Moreno Cole

Theses and Dissertations

We apply a pattern-based classification method to identify clinical and genomic features associated with the progression of Chronic Kidney Disease (CKD). We analyze the African-American Study of Chronic Kidney Disease with Hypertension (AASK) dataset and construct a decision-tree classification model, consisting 15 combinatorial patterns of clinical features and single nucleotide polymorphisms (SNPs), seven of which are associated with slow progression and eight with rapid progression of renal disease among AASK patients. We identify four clinical features and two SNPs that can accurately predict CKD progression. These features are validated with using sophisticated machine learning techniques including Random Forest, Nearest Neighbor, …

Geographic Variability In The Reproductive Hormones And Oocyte Maturation Of Bonefish (Albula Vulpes) In The Bahamas, Ashley Yarbrough

Theses and Dissertations

Bonefish (Albula vulpes) are an extremely popular sport fish that are a vital component of the multimillion-dollar recreational flats fishery. Despite its economic importance for many countries, there is little information available about many aspects of their reproductive biology. Significant gaps include analysis of the hormones that influence oocyte development and the nutrient levels in oocytes that drive embryonic and early larval development and how these parameters vary among habitats. The goals of this study were to characterize and quantify the reproductive hormones, oocyte developmental stages, and nutrient composition of oocytes from fish at or near spawning sites across multiple …

Roles Of Holocene Climate And Pastoralism In Shaping Andean Landscapes, Courtney Renee Shadik

Theses and Dissertations

The Holocene (c. 11,700years ago –present) was a time rich in Andean climatic, environmental, and cultural changes. Assemblages were reforming after the last ice age, millennial scale wet and dry events caused the largest changes in lake level of the last 100,000 years, and humans came to dominate the landscape. Against the backdrop of ecological change, this study asks the following questions-Was the onset of camelid domestication associated with mid-Holocene aridity? Are modern, high-elevation vegetation assemblages a product of manufactured landscapes? What are the long-term effects of intense agropastoralism on paleoecological reconstructions of Andean landscapes? Did Holocene agropastoral domesticates coevolve? …

Bioink Optimization And Effects Of Microgravity On 3d Bioprinted Cell Laden Constructs, Likitha Somasekhar

Theses and Dissertations

Bioengineered 3D tissue constructs have gained attention as in vitro tools for the study of cell-cell and cell-matrix interactions and are being explored for potential use as experimental models for mimicking human tissues. One of the main problems in tissue engineering is the necessity to vascularize complex engineered tissues and sacrificial printing has been recognized as a possible solution to vascularization of the bioprinted tissues. Research studies have demonstrated that exposure to microgravity in space induces adaptive alterations in vascular structure and function. Changes in the morphology and gene expression is observed when endothelial cells are exposed to microgravity and …

Behavior Of Selective Oxygen Functional Groups Upon Hydrothermal Carbonization And Pyrolysis Of Biomass And Their Roles On Selective Applications, Nepu Saha

Theses and Dissertations

Hydrothermal carbonization (HTC) is a thermochemical process where biomass is treated in water under high temperature and corresponding vapor pressure. During HTC, biomass undergoes a series of reactions including hydrolysis, decarboxylation, dehydration, aromatization, and polymerization. As a result, a solid product is produced from biomass after HTC process, which is widely known as hydrochar. Depending on the HTC process conditions, a wide-variety of oxygen-containing groups formed on hydrochar surfaces. Many of these groups could play critical roles in applications such as adsorption, and energy and gas storage, etc. However, not all functional groups are exposed on the surface due to …

Increasing Transgender-Inclusive Behaviors Via Self-Monitoring, Abigail Kaylyn Petronelli

Theses and Dissertations

Within behavior analysis there is an increasing demand for research to create inclusive organizational cultures. To create a culture of inclusion, it is necessary to engage in inclusive behaviors towards individuals of varying race, gender, and sexual orientation. Despite the rising social demand and call for diversity in research, there are still few studies which apply an intervention to improve inclusive behaviors. One target of inclusive behaviors is proper pronoun use towards individuals who are transgender or gender non-conforming (TGNC). To date, there is only one published article regarding TGNC topics, which explored a TGNC-inclusive tool (Leland & Stockwell, 2019). …

Automating Precision Drone Landing And Battery Exchange, Mia Scheider

Theses and Dissertations

As drones become more widespread throughout modern industry, the demand for drone automation increases. Drones are used for many applications, but their effectiveness relies heavily on their battery life. By designing, implementing, and evaluating an automatic drone landing and battery exchange system, drone missions can be more streamlined and efficient by eliminating the need for manual battery exchange. Previous projects within this topic rely on high-precision landing combined with a manipulator with low degrees of freedom for battery removal. This project offers a solution that allows less strict landing requirements to better fit drones of different sizes and shapes for …

Studies On Common Viral And Bacterial Pathogens Of Bovine Respiratory Disease During In Vitro Co-Infection, Caitlyn Cowick

Theses and Dissertations

Bovine Respiratory Disease Complex is a multifactorial disease affecting cattle worldwide resulting in high mortality and morbidity rates in the cattle farming industry. This complex is caused by multiple viral and bacterial pathogens such as Bovine Herpesvirus-1, Bovine Respiratory Syncytial Virus, Mannheimia haemolytica, and Pasteurella multocida; two of the main contributors to the initiation of this disease are Bovine Herpesvirus-1 and the bacteria, Mannheimia haemolytica. Together, these microbes co-infect immunocompromised cattle during times of increased stress and induce a severe pneumonic response along with other health complications. Research has been primarily focused on these microorganisms individually or their effect on …

A Functional Analysis Of The Glycine Max H2a.Z9 Gene Family In Relation To Defense To Heterodera Glycines Parasitism, Sudha Acharya

Theses and Dissertations

The histone 2A (H2A) variant Z (H2A.Z) regulates gene expression, replacing H2A predominately at +1 nucleosomes. Whereas, H2A.Z can act as either a positive or negative transcriptional regulator, this research focuses on its transcriptional activation role. This thesis focuses on examining the Glycine max HTA9 gene family (H2A.Z9). The Arabidopsis thaliana HTA9 protein sequence was used to query the G. max proteome resulting in identification of five H2A.Z9 (H2A.Z9-1-5) paralogs. H2A.Z9-1, H2A.Z9-2, H2A.Z9-4, and H2A.Z9-5 are expressed within Heterodera glycines-parasitized root cells undergoing defense. All 5 paralogs, including H2A.Z9-3, were studied in transgenic-functional analyses. Data demonstrates that H2A.Z9 overexpression leads …

Polymorphism Of Wrky Factors In Corn Inbred Lines Carrying Aflatoxin Resistance Quantitative Trait Loci, Akanksha Awasthi

Theses and Dissertations

Aflatoxin is a highly carcinogenic secondary metabolite produced by Aspergillus flavus contributing to significant loss of corn production. There are several breeding techniques to make the corn resistant to aflatoxin accumulation with the genotype having desirable characters. Corn- resistant inbred line Mp313E provides resistance against A. flavus. Near-isogenic lines containing QTLs were developed by backcrossing Mp313E (resistant parent) and Va35 (susceptible parent). WRKY transcription factors play an important role in the growth and development of plants. Searching DNA markers associated with these WRKY genes is a considerable approach for the plant breeders. In this study, PCR and agarose gel electrophoresis …

Analysis Of Surface Water For Irrigation In The Big Sunflower River Watershed, Meredith Lynn Brock

Theses and Dissertations

Exploitation of groundwater and excess nutrient runoff are major issues plaguing agriculture and streams in the Lower Mississippi River Basin, and increased irrigation intensity has yielded a proportionate increase in water use. Quantifying the use and effects of conservation practices like on-farm water storage (OFWS) systems will justify continued adoption of these practices to mitigate groundwater decline and nutrient runoff. Since 2010, over 795 hectares of surface water storage has been added in the Big Sunflower River Watershed, and analysis of aquifer saturation shows a recent rise in the water table and a decrease in seasonal water table drawdowns. Modeling …

Taste Of Grief & Other Unconventional Love Stories, Madison Brown

Theses and Dissertations

In her book The Hidden Machinery: Essays on Writing, Margot Livesey uses the phrase "the hidden machinery" to refer to two different aspects of novel making: on the one hand, how certain elements of the text characters, plot, imagery work together to make an overarching argument; on the other hand, how the secret, psychic of life of the author, and the larger events of his or her time and place, shape the argument (29). To me, the interconnected craft elements of fiction remains an ongoing enigma. I will delve into the hidden machinery of two authors with whom my own …

Effectiveness Of Equine Assisted Psychotherapy & Learning For Substance Use Disorder Treatment In College-Age Young Adults, Katherine Abigail Cagle-Holtcamp

Theses and Dissertations

With overdose deaths and residential addiction treatment admittance increasing, more treatment options are necessary to meet the demand of services. Equine assisted psychotherapy and learning (EAPL) is a relatively new therapeutic tool in addiction treatment for individuals battling substance use disorder (SUD), and thus, lacks a solid evidence base to be implemented consistently and effectively. The purpose of this dissertation was to determine the effectiveness of EAPL in creating an emotionally safe environment for learning for college-age young adults with a particular focus on those struggling with SUD. This was accomplished in a series of projects focused on: 1) implementing …

Insecticide Resistance Monitoring And Sublethal Effects Of An Insect Growth Regulator On Tarnished Plant Bug (Hemiptera: Miridae), Beverly D. Catchot

Theses and Dissertations

Efforts to implement integrated pest management (IPM) strategies and improving our understanding of existing strategies are keys to achieving adequate control of tarnished plant bug, Lygus lineolaris. Insecticide applications are a part of IPM and monitoring their efficacy is critical for producers to remain profitable. Resistance to imidacloprid, thiamethoxam, and sulfoxaflor was documented, although there continues to remain variability among populations within the region. The insect growth regulator, novaluron, although only lethal to nymphs, plays an important role in management of Lygus. Sublethal impacts to adult plant bugs may be an important factor in reducing populations within the growing season. …

Effects Of Washing Units Of Canine Red Blood Cells On Storage Lesions, Ashley Coll

Theses and Dissertations

In humans, washing stored blood products prior to transfusion reduces storage lesions and the potential for transfusion reaction, but the effectiveness of washing units of canine whole blood is unknown. The objective of this study was to determine if a manual method of washing of stored whole blood units reduced storage lesions without adversely affecting erythrocytes. Units of canine whole blood were stored for 28 days and manually washed three times with sterile .9% NaCl. Following the first wash, there was a decrease in serum potassium (P<.0001), lactate (P<.0001), pH (P=.0110), pCO2 (P<.0001), TCO2 (P<.0001), arachidonic acid (P<.0001), and thromboxane B2 (P=.0417), and increases in iCa (P=.0494), iMg (P=.0024), MCV (P<.0001), MCHC (P=.0093), RDW (P=.0009), hemoglobin (P=.0011), and MCF (P=.0006). No bacterial growth was identified on the post-transfusion samples. Manual washing of stored blood significantly reduces storage lesions after a single wash and additional washing may cause in vitro hemolysis.

Development Of Cell Cultures From The Tissues Of Ictalurid Catfish And Investigation Into The Pathogenesis Of Blue Catfish Alloherpesvirus, Vandana Dharan

Theses and Dissertations

Lack of host-specific cell cultures necessitated initiation of primary cell cultures from ictalurid catfish. Cell cultures from the fin tissues of hybrid catfish ( channel catfish x blue catfish) were developed, characterized, and species of origin molecularly authenticated. Blue catfish alloherpesvirus (BCAHV) is an Ictalurid herpesvirus. When BCAHV was inoculated onto various fish cell lines from different families, the cytopathic effects were restricted to cell lines from family Ictaluridae indicating the host-specificity of virus. A virus challenge using channel, blue, and hybrid catfish indicated mortality due to BCAHV was significantly higher in blue and hybrid catfish. Crowding influenced BCAHV pathogenesis …

Prevalence And Molecular Characteristics Of Avian Pathogenic Escherichia Coli And Clostridium Perfringens In 'No Antibiotics Ever' Broiler Farms, Courtney Fancher

Theses and Dissertations

Avian pathogenic Escherichia coli and Clostridium perfringens cause economic and welfare concerns to the broiler industry. The recent shift to no antibiotics ever (NAE) production has increased disease incidence. The objectives of this study were to determine the influence of season, age of flock, and sample type on E. coli prevalence and virulence and to identify C. perfringens prevalence and toxinotypes in NAE farms. Results indicated high prevalence of virulent E. coli; prevalence of virulent E. coli decreased from Spring to Summer. Virulent E. coli showed high resistance to antimicrobials. Serogroups O8 and O78 were most prevalent in virulent E. …

Estimation Of Wild Pig Damage To Corn Production In The Mississippi Alluvial Valley, David H. Foster

Theses and Dissertations

Wild pigs are known to be an agricultural pest, but few studies have been done to quantify wild pig damage to corn and the landscape characteristics that are conducive to this damage. In the Mississippi Alluvial Valley, only 15 of the 125 sampled corn fields were damaged (12%). Using yield estimates, input costs and hectares of crop lost, this study concluded that wild pigs cause US$1,753 of damage per hectare. The proportion of corn that was planted within selected buffer scales consistently had a negative effect on whether a field would be damaged. The proportion of soybean planted within the …

The Use Of Desmopressin Acetate To Reduce Polyuria And Polydipsia Associated With Prednisolone Administration, Pamela Ann Galati

Theses and Dissertations

Glucocorticoids are used for many purposes in veterinary medicine but often come with significant adverse effects. Polyuria and polydipsia are the most common adverse effects noted by owners. To determine whether administration of desmopressin ameliorated the polyuria and polydipsia, a prospective study with 7 healthy Walker Hounds was performed. Daily water intake and urine specific gravity were measured in dogs under 4 separate conditions: no medications, prednisolone only, prednisolone and desmopressin, and prednisolone immediately after discontinuation of desmopressin. When compared to baseline, six out of seven dogs became polydipsic after administration of prednisolone twice daily. When desmopressin was administered to …

Effects Of Chilling Duration On Usda Quality Grade Of Beef Carcasses, Caitlyn Sarah Haines

Theses and Dissertations

Two hundred and nine beef carcasses (361 ± 53 kg) from crossbred, grain-finished cattle harvested in a commercial packing plant and evaluated for marbling score, core temperature (n=1), pH, shrinkage, color, and aerobic plate count (n=50) for 24, 48, 72, and 96 h under spray chilling. There were minimal changes in shrinkage among time points (-0.4 to 1.2%; P ≤ 0.002), pH (5.56 to 5.69; P ≤ 0.001), and APC (0.1 to 0.7 log; P Ë‚ 0.001). Marbling score values were converted to numeric values of 200 (Practically Devoid00) to 1100 (Abundant00). Carcasses with SM or greater marbling score at …

Modified Biochar Adsorbents For Aqueous Contaminant Remediation, Herath Mudiyanselage Nimeshika Amali Herath

Theses and Dissertations

Continuous population growth and rapid industrial advancement and development have paved the way for ever increasing environmental pollution. At present, water pollution is a serious global issue that threatens environmental sustainability. The contamination of aquatic bodies with potentially toxic organic and inorganic substances are the result of world-wide anthropogenic activities. These pollutants can have detrimental health consequences on humans and ecosystems. Over the past decades, techniques such as chemical precipitation, ion-exchange, adsorption, membrane filtration, and electrocoagulation-flocculation have been developed and employed for the treatment of drinking and wastewater. Among the currently available techniques, pollutant removal by adsorption is most promising …

Symbiosis Components Function To Inhibit Endoparasitic Nematode Infection, Rishi Khatri

Theses and Dissertations

An analysis of Glycine max homologs of the symbiosis genes DOES NOT MAKE INFECTIONS (DMI) DMI1, DMI2 and DMI3 was carried out as it relates to the defense response to Heterodera glycines parasitism. Transgenic analyses of the DMI1, DMI2 and DMI3 for overexpression showed decreased H. glycines parasitism while the analyses for RNAi showed increased H. glycines parasitism. The combination of decreased parasitism in the H. glycines-susceptible genotype G. max [Williams 82/PI 518671] and increased parasitism in the H. glycines resistant genotype G. max [Peking/PI 548402] is taken as the genes function in the defense process at some level. Prior …

Developing And Applying Precision Animal Farming Tools For Poultry Behavior Monitoring, Guoming Li

Theses and Dissertations

Appropriate measurement of broiler behaviors is critical to optimize broiler production efficiency and improve precision management strategies. However, performance of different precision tools on measuring broiler behaviors of interest remains unclear. This dissertation systematically developed and evaluated radio frequency identification (RFID) system, image processing, and deep learning for automatically detecting and analyzing broiler behaviors. Then different behaviors (i.e., feeding, drinking, stretching, restricted feeding) of broilers under representative management practices were measured using the developed precision tools. The broilers were Ross 708 in weeks 4-8. The major findings show that the RFID system achieved high performance (over 90% accuracy) for continuously …