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Design And Synthesis Of Polymeric Metastable State Photoacid And Photo Co-Releasing Materials, Adnan Abdallah Muftah Elgattar

Theses and Dissertations

Metastable state photoacids (mPAHs) are molecules that possess a photoinduced metastable state with high acidity and good reversibility. The metastable state lasts long enough to produce a high proton concentration, which can drive various proton transfer processes. MPAHs have been intensively studied in recent years and applied to different chemical, material, biomedical areas. Covalently linking many mPAHs in a polymer allows the generation of a local proton concentration higher than that of the overall system. This dissertation described my PhD work on the synthesis of mPAH polymers using different radical and ring-opening polymerization methods. These polymers can repeatedly produce a …

The Aqueous Stability Of N-Acyl-L-Homoserine Lactones, Their Affinity For Cyclodextrin Inclusion, And The Investigation Of A Catalyst For Their Hydrolysis, Eric William Ziegler

Theses and Dissertations

Many bacteria demonstrate population-density dependent gene expression, a phenomenon known as quorum sensing, to regulate phenotypes that, if expressed by an individual bacterium, would be ineffective. While some of these phenotypes are innocuous (e.g., exhibiting bioluminescence), certain bacteria employ quorum sensing regulated phenotypes in their pathogenesis. Traditionally, infections by these pathogens have been treated with antibiotic therapies. However, with the emergence of multidrug resistant strains, alternative strategies are being considered for attenuation of quorum sensing regulated traits that do not apply selective pressures. Macrocycles — in particular the cyclodextrins — that are capable of forming inclusion complexes with Gram-negative quorum …

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, …

Inverse Methods For Near-Real Time Estimation Of Surface Heat Flux In Thermal Protection Systems For Space Vehicles, Obinna Oluchukwu Ugochukwu Uyanna

Theses and Dissertations

With the increased goal of manned explorations to outer space, safety during the atmospheric entry/reentry process is paramount as the incident heat fluxes on the surface of vehicle can reach critical values. Thermal Protection Systems (TPS) are therefore essential components in space vehicles as they ensure the safety and protection of the payload and cargo. In order to ensure improved active control capabilities and prolonged used of the vehicle, TPS surface conditions need to be known and determined. Since direct measurement of the surface heat flux using sensors is not feasible, one alternative involves the use of temperature sensors located …

Cathodically Protected Steel Mesh As An Environmentally Friendly Material For Oyster Reef Restoration, Afanasy Melnikov

Theses and Dissertations

Plastic mesh is widely used in oyster reef restoration efforts worldwide, including the Indian River Lagoon (IRL) estuary in Florida. Plastic degrades overtime, releasing microplastics and nanoplastics particles into the environment and causing harm to the marine ecosystem. Thus, there is an ongoing need to find an alternative eco-friendly material. Cathodically protected steel, a possible alternate substrate for such restoration, involves an electrical current running through steel to create an impressed cathodic system. This results in the formation of chalk on the steel, similar to the limestone (calcium carbonate) base of reefs. A benefit of this process is that the …

Effects Of Precessional Forcing In The Early Stages Of The 100-K World, Molly Kingston

Theses and Dissertations

Much of what we know about the Andes today comes from studying a heavily human-manufactured landscape. However, before the presence of human modification in this system (~13,000 years ago), past interglacial and glacial cycles, influenced by changes in Earth cycles (eccentricity, obliquity, and precession), were the cause of major landscape re-organization. The variability in intensity and duration of these events and the probable response of the plant community is not well understood. Very few records in South America extend far enough back in time to capture these changes. Those records that do exist, lack an independent chronology and instead rely …

An Assessment On Microplastic Pollution In The Resacas Of The Lower Rio Grande Valley, Texas, Wesley D. Franklin

Theses and Dissertations

Microplastic pollution is a serious issue that impacts most aquatic environments. Microplastics have the potential to cause numerous detriments to the fitness and reproductive capability of many organisms. The resacas of the Lower Rio Grande are an understudied area that could be sinks for large congregations of microplastics. We analyze microplastic pollution in two species of fish as well as the sediment and water of eleven different pools from four resaca systems. We find that microplastics are present in every pool sampled.

Altogether 218 microplastic pieces are found from the water, sediment and fish samples. We find that microplastics are …

Removal Of Arsenic (Iii) And Arsenic (V) From Aqueous Solution Via Solanum Lycopersicum Phytoremediation And Essential Nutrient Analysis, Grecia W. Garcia Salazar

Theses and Dissertations

ICP-OES was used to investigate the uptake of arsenic (V) and arsenic (III) from aqueous solution using tomato seedlings. The effect of arsenic on essential nutrient uptake by tomato was analyzed. The experiment was performed at three levels of arsenic: 1ppm, 2 ppm and 5 ppm [added as sodium arsenate (Na3AsO4) and arsenic trioxide (As2O3)], in nutrient solution. Plants remained in solution for two weeks. Arsenic accumulation depended on arsenic concentration in solution, when exposed to higher arsenic concentrations the plant uptake increased. The highest arsenic accumulation was found in roots, followed by stems and leaves in that order. Essential …

Understanding An Inflammatory Pathway In Diabetic Retinopathy, Reanna Raye Rodriguez

Theses and Dissertations

Diabetic Retinopathy (DR) is the leading cause of blindness in the U.S. However, not much is known of its molecular pathway and how it attributes to increases in inflammatory response in the eye. One avenue we will investigate is the transforming growth factor beta (TGFB) signaling pathway and its effect of vascular endothelial growth factor (VEGF) secretion and cell viability. VEGF is the hallmark that exacerbates DR progression in prolonged diabetes. Some major concern that have arisen are the underlying effects of oxidants and antioxidants in elevating VEGF secretion in diabetes. In attempt to learn more, we evaluated how an …

Vertical Transmission Of Zika Virus In An Opossum Model, Dionn Carlo Silva

Theses and Dissertations

This study will identify Brazilian ZIKV infection in the offsprings of mated, inoculated Monodelphis domestica females. Unlike non-human primates (NHP) and transgenic mice, M. domestica provides an opportunity to study ZIKV infection in a novel animal model possibly useful for in-utero studies. M. domestica has also been used in cancer and dietary research with varying degrees of success. ZIKV infection will be identified using antibody staining and in situ hybridization. The expected result of this study is that ZIKV will be identified in various tissues and reveal that ZIKV is transmitted vertically in this animal model. The significance of this …

Effects Of Plant Secondary Metabolites And Host Specificity On Growth, Development, And Oviposition Of Lepidopteran Herbivores, Sukhman Singh

Theses and Dissertations

Chapter 1: This chapter provides a review of recent and critical literature on the role of polyphenols in mediating plant-insect interactions. I particularly focused on plant defense induction and mode of action of polyphenols, defense fitness trade-offs, and storage of polyphenols for future defense responses.

Chapter 2: This chapter is about the effects of polyphenol rich purple corn pericarp extract on the growth and development of generalist caterpillar i.e., fall armyworm (Spodoptera frugiperda). This study shows that purple corn pericarp extract rich in polyphenols negatively effects the growth and development of S. frugiperda.

Chapter 3: This chapter …

Winners And Losers In Reforestation Efforts In The Lower Rio Grande Valley Of Texas, And The Predictive Power Of Xylem Anatomy On Long-Term Growth And Survival, Clifton F. Albrecht

Theses and Dissertations

Reforestation has been ongoing in the Lower Rio Grande Valley annually since the 1980s, and to date over 6400 ha of land has been reforested in this area. However, there has been little subsequent study of the change and development of those forests as they mature. This thesis consists of two, interrelated, studies: (1) surveys of a five-site chronosequence of restored forests and (2) quantification of xylem anatomical traits of a subset of species present at the reforestation sites. Surveys showed a consistent reduction in species diversity and stem number density on the landscape, and identified a suite of species …

Virtual Screening For Potential New Chemotherapeutic Agents For The Gpr119 Receptor, A Target For Type Ii Diabetes, Jennifer Lizeth Bravo

Theses and Dissertations

Three frames from a molecular dynamics simulation run of a GPR119 receptor homology model were used for this study. The homology model was validated by virtually screening 76 known GPR119 receptor. 85% of these agonists bound to the receptor. Following the validation, 21,000 molecules were selected for the virtual screening study. 862 ligands came from the GPCR Selleckchem/Prestwick library, 42 compounds from the Prestwick Phytochemical library, 20,000 compounds from the ZINC library, plus four molecules from the literature. All ligands were built, geometry-optimized, and docked in the GPR119 models using a protocol combining High Throughput Virtual Screening, Standard Precision, and …

Opa1 Modulation Of Mitochondrial Dynamics In Ac16 Cardiomyocytes, Patrick De La Torre Schutz

Theses and Dissertations

This thesis explores mitochondrial dynamics in the AC16 cardiomyocytes. Mitochondria are capable of fission and fusion, controlled by specific proteins that respond to cell stress. The transmembrane potential(∆ψm) of the mitochondria is responsible for both bioenergetic functions and regulating the activation of the OMA-1 protein, which regulates the cutting of OPA-1. OPA- 1 has two isoforms: a long (active) and short (inactive) isoforms. Our research is exploring the impact of the levels of OPA1 expression on the observed ∆ψm threshold of mitochondrial fusion. Our laboratory has demonstrated that 143B cells lose L-OPA1 isoforms at [CCCP]> 4.75 µM and …

System For Hiv-1 Treatment To The Brain, Caroline Rose Garcia

Theses and Dissertations

While HIV-1 treatment has been revolutionized by combination antiretroviral therapy in the past two decades, HIV-1 remains persistent in organs that don’t allow easy penetration of anti-HIV drugs (e.g., brain) and cause persistent HIV-1 infections and inflammation. Researchers have turned towards nanotechnology-based drug carriers to combat this challenge, such as nanodiscoidal bicelles (ND) and liposomes. Bicelles entrap the drug in their interior hydrophobic core until metabolized by the body, and the payload can be released at the desired location in a controlled, long-lasting dosage. This study investigated the toxicity and extended-release of an anti-HIV drug-loaded within ND and liposomes for …

Inoculation Of Juvenile Monodelphis Domestica With Zika Virus Using Various Routes Of Infection, Juan Garcia Jr.

Theses and Dissertations

Monodelphis domestica is a small marsupial from South America that has been previously been used in human metabolism research. However, their suitability as models for Zika virus (ZIKV) research, is currently unknown. Preliminary studies have shown M. domestica susceptible to ZIKV through the intracerebral route. We utilized immunohistochemistry, and analyzation of serological responses to show that juvenile Monodelphis domestica can be infected with ZIKV by using various routes of infection that include subcutaneous, intraperitoneal, and intramuscular. ELISAs performed on sera confirmed that juveniles injected with ZIKV by all three routes generated anti-ZIKV antibodies. Additionally, ZIKV nonstructural protein 1 was detected …

Centrifugally-Spun Ceramic/Carbon Composite Fibers And Their Use As Anode Materials In Li-Ion Batteries, Gabriel Gonzalez

Theses and Dissertations

The work in this thesis focuses in the study of Centrifugally Spun Short Fiber Composites and their Implementation as Alternate Anode Material in Li-Ion Batteries. Due to their high theoretical capacity, abundance, and environmental friendliness, metal oxides have been widely studied as alternate anode materials for lithium ion batteries (LIBs). In this research work, the processing of SnO2 and SnO2/TiO2 ceramic short fibers as well as flexible and porous metal oxide carbon fibers (FPMOCFs) by centrifugal spinning followed by an optimized coating technique is reported. In addition, the electrochemical performance of the composites was also investigated and is provided.

Factors That Influence Hispanic Female Pursuit Of An Associate Of Arts Degree At A Hispanic Serving Institution, Maria Victoria Guadarrama

Theses and Dissertations

This study was conducted to investigate the possible influencing factors involved with the Hispanic female population that lives on the Texas and Mexico border and how those factors influence the completion of an Associate of Arts degree at a community college. “Presence in higher education is increasing by all minority groups, except for one; while other ethnic groups—including African Americans—have gradually increased their college graduation rates, Hispanics have seen almost no such progress in three decades” (Montalban, 2015). The border area in southernmost Texas is severely limited by lack of education, parental communication, language background, financial problems, and other influential …

Understanding The Ecological Role, Population Dynamics, And Geographic Distribution Of Manihot Walkerae, Gisel Garza

Theses and Dissertations

Walker’s Manihot, Manihot walkerae Croizat (Euphorbiaceae), is an endangered plant that is endemic to the Tamaulipan thornscrub ecoregion. Understanding M. walkerae’s geographic distribution, populations, and species interactions can provide essential information for the development of sound conservation strategies. To this aim, I asked the following questions: 1) What is the potential geographic distribution for M. walkerae? and, will it be affected by climate change? 2) Using global and regional extinction risk assessments, what is the extinction risk category for M. walkerae after incorporating species distribution models? 3) What do natural history observations reveal about M. walkerae’s population …

Physical And Chemical Defense Mechanisms In Aloe Barbadensis Against Insect Herbivores, Zachary Johnson

Theses and Dissertations

Chapter 1: This chapter provides an overview of insect herbivore impacts on plants and plant defense mechanisms to combat them. I particularly focused on physical and chemical defenses in the broader sense.

Chapter 2: This chapter describes the experiments that showed the effects of extracts from Aloe barbadensis on the growth and development of tobacco hornworm (Manduca sexta) and fall armyworm (Spodoptera frugiperda), model herbivores used to understand herbivore growth and plant defenses. This study shows that extracts from the Aloe differentially affected the growth and development of M. sexta and S. frugiperda. This chapter …

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 …

Examining The Mental Health Of Older Hispanic/Latino Adults: Relationship Between Psycho-Social-Cultural Factors And Depressive Symptomatology, Anna Prado

Theses and Dissertations

The most prevalent disorders affecting the older adult population worldwide are dementia and depression. Ethnic minorities are disproportionately more likely to be affected by these two distressing and debilitating conditions. Hispanic/Latino older adults encounter numerous psycho-social-cultural factors that influence health behaviors, attitudes, and beliefs in positive and negative ways. Presently, research on the influence of these factors on Hispanic/Latino mental health is highly inconsistent. The purpose of the present study is to examine the relationship between selected psycho-social-cultural factors and the mental health of older Hispanic/Latino adults. Using data from the Health and Retirement Study, the association between the Hispanic/Latino …

Flexible And Surface Modified Znsno3 Nanocubes For Enhanced Piezoelectric Power Generation And Wireless Sensory Application, Sk Md Ali Zaker Shawon

Theses and Dissertations

Piezoelectric systems and their mechanisms are held in high regard, due to their cost-effective structure and mechanical proficiency to harvest renewable energy. In the present article, we propose an aluminum-doped zinc stannate (ZnSnO3) piezoelectric nanogenerator that can be employed for the harvest of energy and sensory applications. In order to ensure and further enrich the piezoelectric mechanics and product outcome in our device, ZnSnO3 was doped with 1 wt% to 5 wt% of aluminum nanoparticles. We reported that 2 wt% of aluminum-doped ZnSnO3 showed the highest electrical output in terms of open circuit voltages and short circuit current.

The nanogenerator …

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 …

Transitioning To Housing First: Perceptions Of The Role Of The Rehabilitation Counselor In Serving Homeless Individuals With Disabilities In Puerto Rico, Ana Vanessa Serrano Garcia

Theses and Dissertations

Since the 1980s, the federal government has developed strategies to eradicate homelessness in the US and its territories. The introduction of evidence-based practices like the Housing First Model helped decrease the number of people living homeless. Still, it continues to be a public health problem, especially among chronically homeless individuals, defined broadly as people with disabilities and substance abuse problems experiencing homelessness. Rehabilitation counselors are professionals specialized in serving individuals with disabilities. However, their role in programs identified as Housing First was unclear.

Thus, the study aimed to identify service providers' views, opinions, knowledge, and experiences about the role of …

Developmental Activation Of Mitochodnrial Opa1 Processing Is Retinoic Acid-Independent, Shaynah St. Vallier

Theses and Dissertations

Mitochondria exist as an organellar network within most eukaryotic organisms, and are critical to biochemical energy production and cellular stress response. Mitochondrial bioenergetic function is directly linked to the complex morphological state of its network, existing in a balance of fusion (interconnected state) or fission (fragmented state). The optic atrophy-1 (OPA1) protein plays a major role in regulating mitochondrial inner membrane fusion, whereas the OMA1 metallopeptidase is highly involved in the degradation of the OPA1 protein, thus contributing to its fragmented state. Cellular stress such as a disruption in mitochondrial membrane potential activates OMA1 cleavage of OPA1. However, our data …

Unravelling The Role Of Pgpr "Pseudomonas Fluorescens" In Semi- Arid Soils Of The Rio Grande Valley, Mandip Tamang

Theses and Dissertations

Chapter 1: In this chapter, we have provided a review on the components of rhizosphere engineering and the potential use of PGPR and its challenges to serve as an efficient component for sustainable agriculture.

Chapter 2: In this chapter, we isolated 35 different strains of a PGPR, Pseudmonas fluorescens and characterized various plant growth promoting traits such as production of ammonia, protease, Indole acitic acid (IAA), 1-aminocyclopropane-1-carboxylate deaminase (ACC) deaminase, ammonia, hydrogen cyanide (HCN), and souliblization of zinc and phosphate.

Chapter 3: In this chapter, we tested the influence of plant beneficial soil microbe, P. fluorescens, on the growth and …

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 …

Assessing The Feasibility Of A Biofilter In Medium-To-High Scale Industries, Javier A. Garcia

Theses and Dissertations

The removal of volatile organic compounds, VOCs, from contaminated sources of air stream has become a major air pollution risk. Excessive amounts discharged to the atmosphere are highly risky to human health and to the environmental system. Demand for sustainable VOC control technologies has become crucial for the reduction of emissions. Biological treatments of waste gas streams, such as biofiltration, have proven to be cost effective and environmentally friendly compared to conventional pollution control technologies. The goal of this research is to simulate data for a given biofilter model, and to evaluate if it is economically and environmentally feasible to …

Metastable State Photoacids And Ultrasound Responsive Carbon Monoxide Releasing Polymer Micelle, Osamah Zaid Saleh Alghazwat

Theses and Dissertations

This dissertation described my Ph.D. work on the development of a novel metastable state photoacids (mPAH), which can be activated by near infrared light and a reversible mPAH switched by different wavelengths of light. Also, it described the development of a micelle that responded to ultrasound to localized carbon monoxide CO delivery. An introduction of metastable state photoacid is given in Chapter 1. In Chapter 2, described my work on the development of a novel mPAH, which can be activated by near infrared light is an important factor for various biological functions. mPAH was designed and synthesized with a donor-acceptor-donor …