Digital Commons Network^™

Aquatic Stage Mosquito Biocontrol: Effects Of Entomopathogenic Fungi Blastospores And Conidia On Aedes Aegypti Pupae, Ricardo Alberto Ramirez Garcia Rojas

Theses and Dissertations

Fungal entomopathogens present an opportunity to produce mosquito controls on-site, from remote locations to developing communities. Locally produced biopesticides have the potential to empower communities to develop internal disease vector control initiatives to protect local public health. We tested the effectiveness of the conidia solution and blastospore solution of Metarhizium anisopliae E9, Metarhizium anisopliae E1037, Isaria fumosorosea A97, and Isaria fumosorosea 9901 in controlling Aedes aegypti pupae. We observed that entomopathogenic fungi liquid blastospore solution induce mortality in Aedes aegypti pupae at a significantly greater rate than conidia solution and control treatment.

However, further analysis of testing methods used in …

Effects Of Seasonal Variations And Heat Exposure On Antioxidant Expression And Redox Status In The American Oyster, Crassostrea Virginica: Field And Laboratory Studies, Md Sadequr Rahman

Theses and Dissertations

Increasing atmospheric temperatures influence physiological functions in aquatic organisms. In this study, I observed the effects of seasonal (field study) and laboratory heat exposure (16, 22, 26, and 30°C for 1-week) on prooxidant-antioxidant homeostasis in gills and digestive glands of American oyster. Histological analysis showed an increase in mucus secretion with elevated temperatures in both organs. Immunohistochemical analysis showed a significant increase of heat shock protein-70, dinitrophenyl, and 3-nitrotyrosine protein expressions with higher seasonal and laboratory temperatures indicating heat-induced oxidative and nitrosative stress. This was concomitant with gradual rise in cellular apoptosis. Interestingly, catalase and superoxide dismutase expressions also increased …

Exploring Plant-Plant Interactions And Nutrient Manipulation As Strategies For Thorn Scrub And Thorn Forest Restoration, Edgar D. Vasquez

Theses and Dissertations

Restoration of thorn scrub and thorn forest communities in South Texas is hindered by harsh environmental conditions and hypercompetitive invasive grasses. The success of thorn scrub/thorn forest restoration efforts depends on increasing seedling survival and growth by reducing stress after transplantation. Four experiments evaluated initial effects of plant-plant interactions and nutrient manipulation on thorn forest restoration. High density planting along with the use of nurse plants look promising; survival was generally higher under these conditions and growth was unaffected or in the case of high-density planting, promoted. Nutrient sequestration by sorghum had little effect on seedling performance and cover of …

Autoethnography: A Self Reflection Of The Benefits In Attending A T-Stem High School, Adriana Garza

Theses and Dissertations

The purpose of this autoethnography is to analyze the benefits I obtained as a bilingual, first-generation, Hispanic student by attending a STEM high school. PSJA Thomas Jefferson T-STEM Early College High School provides an Early College experience as well as a Bilingual STEM environment in a district located at La Frontera. This autoethnography uses two techniques to collect data: artifacts and reflective journals. As the researcher, I self-reflected and analyzed my own success story which will be viewed through a Narrative Inquiry lens to answer two questions 1) to what extent has the STEM model/ curriculum influenced my academic …

Analysis Of The Functional Relationship Of Protein Kinase Families Using Phospho-Proteomics Data, David A. Parra Peña

Theses and Dissertations

As cancer research advances, Mass-spectrometry based proteomics is becoming a widely used technique for proteome characterization. Phosphoproteomics is a specific type of proteomics that characterizes proteins with the reversible post-translational modification of phosphorylation PTM), which has allowed the identifications of thousands of phosphorylation sites. These phosphorylation sites, also known as substrates, are known to interact with a protein type named kinases. Studies have shown that abnormal phosphorylation activity is related to cancer diseases. Moreover, these kinases are divided into families, based on the similarity of their catalytic domain, as this part of their amino acid sequence determines a large part …

Characterization And Quantification Of Dopamine Neurons In The Ventral Midbrain: Implications For Neurological Disorders, Magaly Vargas

Theses and Dissertations

Neurological disorders like Parkinson’s Disease affect millions of individuals around the world. Parkinson’s Disease is associated with the degeneration of dopamine neurons in structures of the ventral midbrain, such as the substantia nigra and the ventral tegmental area. It is important to elucidate the neural mechanisms of neurological disorders for the development and application of pertinent therapies and treatments.

Here, we implemented a modified approach of stereological investigation to characterize and quantify the expression of tyrosine hydroxylase, a significant dopamine biomarker, in a neurotoxin-based animal model of PD. By doing so, we hope to better understand the structural components of …

Strategic Organizational Sustainability Climate: Scale Development And Validation, Petra Brnova

Theses and Dissertations

The Strategic Organizational Sustainability (SOS) Climate encompasses the employee perceptions of the policies, practices, and procedures that promote long term organizational success in the era of pressing economic, social, and environmental challenges. In order to promote such workplace climate, organizations must be able to measure it. To this end, the SOS Climate scale was developed and validated using first a phenomenological approach in interviews with sustainability professionals working in organizations across economic sectors. After this, scale items were generated and judged, followed by a pilot study. Principal component analysis was conducted for preliminary dimensionality and item reduction. Lastly, confirmatory factor …

Application Of Neural Networks For Solving One Dimensional Inverse Heat Conduction Problems With Surface Ablation, Jian Zhang

Theses and Dissertations

Thermal protection systems (TPS) are critical for space vehicles to keep them safe against extensive aerothermal heating, particularly during the atmospheric entry. Ablative materials burn away gradually when subjected to extreme heat flux and therefore are considered as a practical option for TPS application. Measurement of TPS surface condition, particularly heat flux, is essential to reduce design margins and also improve active control strategies for damage avoidance. However, it is not possible to directly measure TPS surface heat flux, and alternative approaches must be utilized for this purpose. One method is to use temperature sensors at internal layers and solve …

Development Of A Graphical User Interface For Ecg Signals Classification Using Statistical Features Analysis, Mousa Hammad S Aldosari

Theses and Dissertations

Cardiac diseases are the most common cause of mortality in the world. The detection of cardiac arrhythmias is not a straightforward process, since minor variations in the electrocardiogram (ECG) signals cannot be easily identified manually. Therefore, automatic detection and classification of cardiac arrhythmia would shorten the diagnostic time and accelerate medical intervention resulting in reducing the mortality rate. In this thesis, I have developed a simple and low-cost computer-aided diagnostic system using MATLAB-based Graphical User Interface (GUI) to facilitate fast operation and access to the data along with the overall accuracy of the system. The acquired ECG signals are processed …

Effect Of Electron Demand On Sensing Behavior Of Carbazolopyridinophanes, Grace Abban

Theses and Dissertations

Hydrazine (HZ), monomethylhydrazine (MMH), and 1,1-dimethylhydrazine (UDMH) are widely used as high energy rocket propellants in bipropellant rocket engines. However, hydrazine and its derivatives are highly flammable and carcinogenic. Currently, hydrazine sensors used for detection are irreversible which makes them costly. Two proposed carbazolopyridinophanes containing intramolecular hydrogen bonds were synthesized to detect hydrazine as real-time reversible sensors. However, their thresholds for detection (100 and 25 ppb for CPand 22OMeCPrespectively) were above the regulatory limit of 10 ppbdue to background fluorescence. It was established that the quenching of carbazole in the presence of the CP system has a direct correlation to …

Mechanical And Material Properties Of Nitinol And Its Application To Stents, Ariana Solis Eichler

Theses and Dissertations

Nitinol is a functional material with superelastic and shape memory properties derived from its unique molecular structure. The purpose of this thesis is to explore how the material and mechanical properties of self-expanding Nitinol stents affects the forces applied to arterial walls during stent deployment compared to the traditional balloon-expanding stainless steel stents, in addition to contrasting thin and thick-walled pressure vessel mathematical models. Nitinol’s mechanical properties can be optimized for stent applications by tailoring its processing procedures. Nitinol stents demonstrated a reduced circumferential hoop stress on the vessel wall and greater factor of safety with respect to vessel rupture …

Using Disruptive Coloration And Ultraviolet Light To Prevent Barnacle Settlement, Kailey Nicole Richard

Theses and Dissertations

Biofouling or the accumulation of unwanted micro and macro organisms is problematic for the shipping industry. Barnacles are one of the most abundant fouling organisms and their settlement on ship hulls can result in costly damage. Several methods have been developed to prevent the formation of biofouling, including antifouling coatings and mechanical techniques, but the search for more effective and environmentally friendly solutions is still ongoing. This thesis investigated two methods aimed at barnacle prevention: color patterning and the application of ultraviolet light. The first method utilized disruptive coloration, a common mechanism observed in nature by terrestrial organisms (i.e. butterflies) …

Organic Sediment Impacts On Seagrasses And Their Associations With Benthic Fauna, Sean Matthew Crowley

Theses and Dissertations

Human-population growth and rapid rates of urbanization have led to eutrophic conditions in estuaries throughout the world. Effects often include severe algal blooms, decreased dissolved oxygen levels, and the accumulation of fine-grained organic-rich sediments. One frequent negative consequence of eutrophication is the decline of seagrasses, a vital component of coastal ecosystems. Seagrasses provide shelter from predation, serve as nursery habitat, stabilize sediments, act as a sink for excess carbon, produce oxygen, and are a food source for many herbivores. Seagrasses are also sensitive to environmental changes, such as declining water quality and increased sedimentation rates. This study examines the impacts …

Numerical Simulation Of Low Reynolds Number Locomotion In Viscoelastic Media, Nesreen Abdulrahim Althobaiti

Theses and Dissertations

We use computational models to investigate 2D swimmers within various fluid media with low Reynolds Number. Extensions of the standard Immersed Boundary (IB) Method are proposed so that the fluid media may satisfy no slip, partial slip or free-slip conditions on the moving boundary. The fluid equations are solved through a Multigrid preconditioned GMRES solver. Our numerical results indicate that slip may lead to substantial speed enhancement for swimmers in a viscoelastic fluid, as well as in a viscoelastic two-fluid mixture. Under the slip conditions, the speed of locomotion is dependent in a nontrivial way on both the viscosity and …

Embryonic Exposure To The Synthetic-Progesterone Levonorgestrel (Lng) Results In Hyperactive Behavior In Zebrafish (Danio Rerio), Austin D. Fuentes

Theses and Dissertations

Exposure to endocrine-disrupting chemicals has been associated with an increased risk of anxiety-like behavior at various life stages. Levonorgestrel (LNG), a synthetic contraceptive, could potentially alter steroidal regulated brain development based on the findings of this thesis. In-silico measurements were used for comparing LNG, which had been found in surface water, to chemical databases to predict the bioavailability, half-life, and estrogen binding potential. Zebrafish (Danio rerio) for illuminating the effects of LNG exposure during early zebrafish embryonic development, similar to fetal development, on behavior was investigated. Our data suggests exposure in a dose-dependent manner of LNG can potentially …

Influence Of Landscape Factors On Wildlife Presence And Road Mitigation Structure Performance, Taylor M. Hopkins

Theses and Dissertations

There are roughly 80 ocelots (Leopardus pardalis) remaining in the United States, with the entire population constrained to south Texas, with roadkill being a predominant source of mortality. To prevent additional roadkill and maintain wildlife movement, Texas Department of Transportation constructed 11.9 kilometers of wildlife exclusion fencing, 5 wildlife crossing structures (WCS), and 18 wildlife guards on State Highway 100. This thesis focused on determining the effort required for a control-impact monitoring study, the influence of biotic and abiotic factors around the roadway on wildlife presence, and the performance of mitigation structures and the road mitigation corridor. This …

A Comprehensive Comparison Of Teratogenic Compounds Known To Induce Neural Tube Defects In The Chicken Embryo, Micah Marie Ross

Theses and Dissertations

One of the first embryonic structures generated during early human development is the neural tube. The embryonic process of neurulation, including neural tube closure, is necessary for proper brain and spinal cord development, whereas improper closure leads to neural tube defects including anencephaly, spina bifida, and craniorachischisis. The mechanism by which these defects occur is unknown, but some evidence suggest that redox disruption may play a role. Cellular redox state is important in regulating key processes during neural tube closure, including differentiation, proliferation, gene expression, and apoptosis. This study aims to determine whether redox potential shifts and these key processes …

Activity, Stability, And Binding Capacity Of Β-Galactosidase Immobilized On Electrospun Nylon-6 Fiber Membrane, Deborah Ann Hutchins

Theses and Dissertations

This research explores various immobilized enzyme support materials, including the novel nylon-6 fiber membrane (NFM), observing the increase of surface area and what effect that has on enzyme binding potential. This study also manipulates incubation and reaction conditions and observes what affect that has on activity and stability of β-galactosidase comparing various solid support materials and free enzyme. Nylon-6 fiber membranes were created using the process of electrospinning and were compared with other materials as solid support materials for enzyme binding. The other materials included polyvinylidene fluoride 5 kD nanofiltration dairy membranes, nylon-6 pellets, silica glass beads, and free—dissolved—enzyme. Scanning …

Optimal Learning Rates For Neural Networks, Tyler Moncur

Theses and Dissertations

Neural networks have long been known as universal function approximators and have more recently been shown to be powerful and versatile in practice. But it can be extremely challenging to find the right set of parameters and hyperparameters. Model training is both expensive and difficult due to the large number of parameters and sensitivity to hyperparameters such as learning rate and architecture. Hyperparameter searches are notorious for requiring tremendous amounts of processing power and human resources. This thesis provides an analytic approach to estimating the optimal value of one of the key hyperparameters in neural networks, the learning rate. Where …

Biological Control Potential Of Streptomyces Isolates On Pathogens (Helminthosporium Solani And Pythium Ultimum) Of Potatoes, Shae Jamison Taylor

Theses and Dissertations

Two fungal pathogen species, Helminthosporium solani and Pythium ultimum, cause significant economic loss to potato (Solanum tuberosum) growers throughout the world. These pathogens have substantial differences in cellular makeup, pathogenicity, and modes of infection. We studied the efficacy of 82 isolates within the bacterial genus Streptomyces in inhibiting these pathogens under laboratory and greenhouse conditions. Derivatives of Streptomyces have significant implications in medicinal use because of their antibiotic and antifungal properties. Under in-vitro conditions, 25% of Streptomyces isolates inhibited growth of P. ultimum, up to 81%. Ninety-five percent of the Streptomyces isolates inhibited growth of H. solani, with a maximum …

Developing Rangeland Restoration Techniques: A Look At Phosphorus Fertilizer As A Seed Coating To Improve Bluebunch Wheatgrass Growth, Morgan Elaine Parkinson

Theses and Dissertations

Planting native species after a major disturbance is a critical tool land managers use to stabilize soils, restore ecosystem processes, and prevent weed invasion. However, within the sagebrush steppe and other arid and semi-arid environments the percentage of sown seeds that produce an adult plant is remarkably low. Applying fertilizers at the time of planting may improve native plant establishment by increasing the ability of the seedlings to cope with environmental stresses. However, traditional fertilizer applications are often economically infeasible and may be counterproductive by encouraging weed invasion. Seed coating technology allows for the efficient application of fertilizers within the …

Predation Environment Does Not Predict Life History In Morphologically-Constrained Fish Alfaro Cultratus (Cyprinodontiformes: Poeciliidae), Kaitlyn Beard Golden

Theses and Dissertations

Predation is known to have a significant effect on life history, eliciting predictable responses. Physical constraints of body shape and size may also limit life history divergence. There may be a trade-off between adapting to predation, and limits placed by constraints that decrease life history divergence. We test this idea in the Costa Rican livebearing fish Alfaro cultratus. This species has a keeled ventral surface and does not develop a distended abdomen when pregnant like other livebearers. We describe the life history of A. cultratus in 20 different populations across predator and non-predator environments. We found significantly lower reproductive allotment …

The Effects Of Exercise On The Fasting Ketone Production Curve: A Randomized Crossover Study, Landon S. Deru

Theses and Dissertations

Elevated ketone production and utilization results in a host of health benefits. The aim of this study was to assess the rate of ketone production during a prolonged fast and to evaluate how an initial bout of exercise influences this production. Mood and hunger, along with plasma insulin and glucagon, were also assessed. In this crossover study, 20 adult subjects (11 Male, 9 Female) completed two 36-hour fasts, with one protocol requiring the subject to complete an intense treadmill exercise session at the beginning of the fast. Ketone levels were assessed via blood ketone meter and recorded every two hours. …

Be Good For Goodness' Sake: Parenting Practices That Promote Value-Congruent Behavior During Adolescence, Ryan David Mclean

Theses and Dissertations

Research indicates that adolescence is an especially crucial time for developing habits of values congruent behavior that will persist throughout the lifespan. Past research has suggested that parents may play an important role in socializing their children, however few studies have looked at the mechanism through which this socialization occurs. The current study explored associations between different types of proactive and reactive parenting and value congruent behavior using nationally representative data from across three years during adolescence. Additionally, the current study attempted to further explain these associations through the mechanism of extrinsic and intrinsic values regulation. The current sample included …

At Ages 1-2, Will Tv Impact If I Help You? Prosocial Media, Joint Media Engagement, And Infant Prosocial Development During The Second Year, Sara Catherine Brown

Theses and Dissertations

Prosocial behavior typically emerges during an infant's second year. Because it is posited to be continuous from infancy to adulthood, and past research has identified numerous positive outcomes associated with prosocial behavior, it is important to understand the mechanisms involved in early prosocial behavior, such as prosocial media. Past research has examined the relation between prosocial media and prosocial behavior in preschool children, but no studies have explored this association with infants. The current study includes 60 infants and their primary caregivers. Data about media use, parent-infant media interactions, and infant prosocial helping was collected through survey and observational measures. …

The Anti-Diabetic Potential Of The African Adansonia Digitata L. Plant Extract, Marwa Tawfik Badawy

Theses and Dissertations

Diabetes Mellitus (DM) is a severe chronic disease affecting a large population worldwide. The Middle Eastern region has been gifted with lots of native medicinal plants. However, there is less information on development of these medicinal plants into nutraceuticals for modulating specific diseases such as diabetes of common occurrence regionally. Towards this end, there is a crucial need to investigate other types of treatments to modulate diabetes. This study is conducted to fill in this gap by investigating medicinal plant used as folk medicine, which is Baobab (Adansonia digitata L.). This study is performed in two phases: in-vitro and in-vivo. …

African Refugee Women In Egypt: Lacunae In International Refugee Law And The Erasure Of Disadvantaged Groups, Wigdan Mohamad

Theses and Dissertations

Migration is not a recent phenomenon. From the first humans, to people all around the globe today, leave their homes in search of a better life. Since February 2020, Egypt, an attractive destination due to its strategic geolocation, homes the “fifth largest urban refugee population in the world ”. Persecution, political instability, climate degradation, protracted conflicts, unrest, and new wars throughout Africa and Middle Eastern region has caused a dramatic rise of refugees, many of whom make their way to Egypt with the hopes of finding refuge. Egypt hosts a diverse community of refugees, asylum-seekers, and failed asylum-seekers from 58 …

The Development Of A New Entry Point Into Enantiomerically Enriched Sulfinyl Derivatives, Jessica Shaw

Theses and Dissertations

Optical probes may be used as reliable tools for detecting and imagining the inside of cells for medical diagnostics. Among available options, the use of thiol probes is of interest as thiols are present in nearly all cells and their levels are tightly regulated, thus any variation is associated with disease. A proper thiol bioimaging probe must have a thiol cleavage group/reactive group and a fluorophore. It is found that novel sulfinate aryl ester (phenoxysulfinate esters) probes selectively cleave thiols at physiological pH and show much promise as effective tools for bioimaging.

In this context, the synthesis of the related …

Use Of Viologens In Mediated Glucose Fuel Cells And In Aqueous Redox Flow Batteries To Improve Performance, Meisam Bahari

Theses and Dissertations

This dissertation presents my efforts to use viologens to improve the performance of glucose fuel cells and aqueous redox flow batteries. These two electrochemical systems have the potential to efficiently exploit renewable sources of energy. The contributions and significance of this work are briefly described below. Glucose Fuel cells. For glucose fuel cells, viologens were adopted as an electron mediator to facilitate the transfer of electrons from glucose to electrodes for power generation. Use of a mediator circumvents the need for precious metal electrodes to catalyze glucose oxidation. Both the oxidation efficiency and rate of glucose oxidation are important to …

Development And Analysis Of A Vibration Based Sleep Improvement Device, Benjamin John Himes

Theses and Dissertations

Many research studies have analyzed the effect that whole-body vibration (WBV) has on sleep, and some have sought to use vibration to treat sleep disorders such as insomnia. It has been shown that low frequencies (f < 2Hz) are generally sleep inducing, but oscillations of this frequency are typically difficult to achieve using electromagnetic vibration drives. In the research that has been performed, optimal vibration parameters have not been determined, and the effects of multiple vibration sources vibrating at different frequencies to induce a low frequency traveling wave have not been explored. Insomnia affects millions of people worldwide, and non-pharmacological treatment options are limited. A bed excited with multiple vibration sources was used to explore beat frequency vibration as a non-pharmacological treatment for insomnia. A repeated measures design pilot study of 14 participants with mild-moderate insomnia symptom severity was conducted to determine the effects of beat frequency vibration, and traditional standing wave vibration on sleep latency and quality. Participants were monitored using high-density electroencephalography (HD-EEG). Sleep latency was compared between treatment conditions. Trends of a decrease in sleep latency due to beat frequency vibration were found (p ≤ 0.181 for AASM latency, and p ≤ 0.068 for unequivocal sleep latency). Neural complexity during wake, N1, and N2 stages were compared using Multi-Scale Sample Entropy (MSE), which demonstrated significantly lower MSE between wake and N2 stages (p ≤ 0.002). Lower MSE was found in the transition from wake to N1 stage sleep but did not reach significance (p ≤ 0.300). During N2 sleep, beat frequency vibration shows lower MSE than the control session in the left frontoparietal region. This indicates that beat frequency vibration may lead to a decrease of conscious awareness during deeper stages of sleep. Standing wave vibration caused reduced Alpha activity and increased Delta activity during wake. Beat frequency vibration caused increased Delta activity during N2 sleep. These preliminary results suggest that beat frequency vibration may help individuals with insomnia symptoms by decreasing sleep latency, by reducing their conscious awareness, and by increasing sleep drive expression during deeper stages of sleep. Standing wave vibration may be beneficial for decreasing expression of arousal and increasing expression of sleep drive during wake, implying that a dynamic vibration treatment may be beneficial. The application of vibration treatment as part of a heuristic sleep model is discussed.