Life Sciences Commons^™

A Comparison Of Ground Reaction Forces And Muscle Activity Of The Tsunami Bar® Against A Rigid Barbell During Back Squat Phases, John Carver Middleton

Theses and Dissertations

An Institutional Review Board (IRB)-approved study was conducted to investigate the effects of the Tsunami Bar® (TB), a flexible barbell, on ground reaction force (GRF) production and muscle activity in the quadricep, hamstring, and gluteal muscle groups during phases of the squat exercise and compare the effects to the effects to using a rigid barbell (RB). A two-by-two repeated measures Analysis of Variance (ANOVA) test was used to compare the results. Descriptive statistics showed significantly higher GRFs for the TB during the unweighting phase, significant differences in GRFs between speeds for each phase, significantly higher forces on average with the …

A Silvicultural Approach To Increase Drought Resistance And Resilience In Longleaf Pine, Kyle R. Dues

Theses and Dissertations

Droughts are a common disturbance experienced by forest systems across the southeastern United States and are expected to increase in frequency in the near future. Few empirical studies have evaluated the response of individual tree resistance and resilience following silvicultural treatment in longleaf pine (Pinus palustris Mill.). This study evaluates the differences in drought responses between two forests during three different periods. The first period evaluated pretreatment (2000) conditions, while the second (2006), and third (2011) compared conditions after the implementation of five silvicultural treatments. The main findings are that, as additional basal area is removed, both individual tree …

Impact Of Soil Moisture Stress At Different Phases Of Corn Growth And Development, Ranadheer Reddy Vennam

Theses and Dissertations

Suboptimal soil moisture during the growing season often limits growth and yield potential of corn. This study aimed to assess the impact of varying soil moisture regimes on corn growth at different growth phases involving vegetative, flowering, and grain-filling stages. Exposure to moisture stress (80% of the control) during the vegetative stage resulted in a 65% reduction in stomatal conductance and increased the canopy temperature by 5 ^oC, which led to a substantial decrease in total dry matter (56%). Moisture stress-induced reductions in silk length (19%) and fresh weight (34%), negatively affected kernel number (53%), and weight (54%). Unlike …

Investigating The Localization Of Foxo4 Transcription Factor In U87mg Glioblastoma Cell Line, Millat Jahan

Theses and Dissertations

FOXO transcription factors perform diverse functions that have effects on significant biological processes like stem cell homeostasis, cell cycle, apoptosis, and cell fate determination. This research focuses on FOXO4 that is differentially localized in U87MG glioblastoma cells where FOXO4 is targeted to the nucleus. This research is aimed at investigating the mechanism and localization of FOXO4 in U87MG cell lines. Using chimeric fusion construct, we have mapped regions within FOXO factors that can determine specific cellular localization patterns. Finding the mechanism behind specific nuclear localization of FOXO4 can produce innovative data to better understand the distinctive subcellular localization patterns in …

Vertical Transmission Of Zika Virus In Monodelphis Domestica, Mohini Moulick

Theses and Dissertations

Zika Viral infection in pregnant women may lead to infants born with microcephaly and other neurological complications, making Zika viral research imperative. Prior research demonstrated Monodelphis domestica to be a unique animal model for Zika virus studies, and viral proteins were detected in brain tissue of juveniles after intracerebral inoculation of infants. We wanted to determine if we can detect a viral protein, non-structural protein 1 (NS1), in brain tissue after intraperitoneal inoculation and we found it to be possible through immunohistochemistry (IHC) analysis. We also investigated if inoculated dams (mothers) would give rise to Zika positive pups (natural inoculation), …

The Effects Of Low Volume High-Intensity Interval Training Vs. Moderate-Intensity Interval Training With Blood Flow Restriction On Body Composition, Hormone Concentration, And Arterial Elasticity In Overweight And Obese Male Adults, Alexis Lopez

Theses and Dissertations

PURPOSE: This study compared the effects of HIIT and MIIT+BFR on the adaptations in body composition, salivary hormone concentration, peak oxygen uptake, anaerobic parameters, and arterial elasticity in young overweight and obese male adults.

RESULTS: There was a significant increase in total BMC (p<0.01), leg BMC (p<0.05), and trunk BMC (p<0.05) from baseline in response to HIIT. MIIT+BFR significantly increased LFM/TFM Ratio from baseline (p<0.01). HIIT significantly decreased AIx@75 (p<0.05) and CI (p<0.05). There was a significant increase in ISO 180o Away (p<0.05), Thor Begin. (p<0.01), and Thor Mid. (p<0.05) in response to HIIT. MIIT+BFR had a superior increase in Thor Mid. (p<0.05) and significantly increased ISO 180o Toward (p<0.01), VO2peak (p<0.05), and VO2peak:Time (p<0.05). In the last training session, HIIT significantly increased salivary leptin (p<0.05), but MIIT+BFR had a superior increase in salivary leptin (p<0.01) from pre- to post exercise.

CONCLUSION: HIIT significantly improved total BMC, leg BMC, trunk BMC, and AIx@75 but decreased CI from baseline. HIIT increased quad muscle strength, whereas MIIT+BFR increased hamstring muscle strength. HIIT and MIIT+BFR significantly increased peak torque in Thor Mid and salivary leptin. Only MIIT+BFR significantly improved VO2peak.

Effect Of Pre-Growth Conditions On Foodborne Pathogen Survival Kinetics In Fresh Produce, Avninder Kaur

Theses and Dissertations

World-wide consumption of fresh-cut produce has seen a dramatic increase over the past few decades. However, fresh-cut produce has been implicated in several illness outbreaks due to contamination with foodborne bacterial pathogens. Post-harvest contamination during handling and processing is considered rare but several influencing factors are often overlooked. Specifically, studies have reported the growth, survival, and death kinetics of foodborne bacterial pathogens such as E. coli O157: H7, Salmonella and Listeria monocytogenes in different fresh and fresh-cut produce. The effect of various factors such as storage temperature, time, and relative humidity are widely explored. It is increasingly evident that microbial …

The Effects Of Caffeine On Activity Levels And Motor Behaviors In The Honeybee, Apis Mellifera, Johana Castro

Theses and Dissertations

Caffeine is produced by plants as a defense mechanism against herbivores and pathogens. However, caffeine was found in floral nectar, which contradicts nectar's role in attracting pollinators. Interestingly, low concentrations of caffeine were shown to increase alertness and locomotion in mammals and invertebrates, indicating it may enhance the productivity of pollinators. This investigation examined how caffeine affects activity levels and motor behaviors in the honey bee, Apis mellifera. To test overall activity, forager bees were collected and fed 1 M sucrose to satiation. The following day, bees received 10 µl of 1.0 M sucrose alone or with caffeine ranging from …

Understanding The Distribution And Abundance Of Asclepias Prostrata In South Texas, Elizabeth Ann Gonzalez

Theses and Dissertations

Asclepias prostrata, commonly referred to as prostrate milkweed, is a rare South Texas native plant species. In February of 2023, A. prostrata was listed as a federally endangered species by the U.S. Fish and Wildlife Service. Due to the limited available observations and literature for A. prostrata, this study was completed to bring new information that could be utilized for future restorative efforts. This study includes multiple field observations of the plant’s morphology, plant-insect interactions, extraction and transplanting of the species, and a seed viability study. Results indicate that although A. prostrata has many pressures that limit its …

Fungal Plant Pathogens Affecting Crops In The Lower Rio Grande Valley, Isabel Martinez

Theses and Dissertations

The Lower Rio Grande Valley (LRGV) located in South Texas has a subtropical and humid environment which is conducive for plant disease. In Chapter 1, Southern blight caused by Athelia rolfsii was collected from Edinburg, Texas in tomato and bean crops. The present study focused on assessing the role of temperature on growth and sclerotia production. We found that there is an optimal growing temperature for both hyphal growth and sclerotia production. In Chapter 2, red rot fungal disease was collected from sugarcane in Texas. Morphology, pathogenicity, effects of temperature, and biocontrol agents were assessed. Isolate morphology closely resembled Fusarium …

The Effects Of Pain Levels On Static And Dynamic Postural Control And Visual Reliance In Chronic Ankle Instability Individuals, Minsub Oh

Theses and Dissertations

Context: Chronic ankle instability (CAI) individuals experience residual symptoms including pain, swelling, ankle instability, etc. A small majority of CAI individuals report ankle pain during daily or physical activity. Despite the known negative effects of chronic pain on neuromuscular control, there is a paucity of research exploring the specific impact of chronic pain mechanisms on altered neuromuscular control in CAI individuals. Purpose: The purpose of this study was to identify the effects of pain levels on static and dynamic postural control and visual reliance in CAI individuals. Methods: A total of 60 participants were recruited, consisting of 20 CAI individuals …

Studies Of Intracellular Trafficking Of Phospholipids Triggered By Osh6, Ilham Hassoon Kadhim

Theses and Dissertations

Yeast vacuoles (mammalian lysosomes) and their closely related organelle late endosomes (LE) play a central role in anti-aging processes since they host the target of rapamycin complex 1 (TORC1). A recent study showed that the vacuolar TORC1 stimulates protein synthesis and cell growth while the late endosomal TORC1 inhibits autophagy, an anti-aging process. This raises a question as to which membrane trafficking pathways toward LE/vacuoles are critical in controlling endosomal TORC1 and anti-aging processes. Members of the family of oxysterol-binding proteins mediate non-vesicular lipid transport between membranes and contribute to longevity in different manners. We previously found that a 2-fold …

The Effects Of Ketones On Brain Metabolism And Cognition, Erin Reiko Saito

Theses and Dissertations

The brain is one of the most energetically demanding organs within the human body and is cognitively susceptible to energetic deficits such that the rise in obesity, insulin resistance, and Alzheimer’s disease in recent decades pose a substantial threat to cognitive longevity. The therapeutic efficacy of ketones are well-established in epilepsy and are currently being applied to other disease states. Alzheimer’s disease is characterized by impairments in brain glucose uptake and metabolism in regions relevant to learning, memory, and cognition that progress with the disease. While brain glucose uptake is impaired, ketone uptake is unaltered, potentially enabling ketones to fuel …

Relationships Between Running Biomechanics And Femoral Articular Cartilage Thickness And Composition In Anterior Cruciate Ligament Reconstruction Patients, Hyunwook Lee

Theses and Dissertations

Background: Patients with anterior cruciate ligament reconstruction (ACLR) have demonstrated morphological and compositional changes in femoral articular cartilage. However, it is unclear how running biomechanics are associated with femoral cartilage thickness and composition for both ACLR patients and controls. Objectives: (1) to compare measures of femoral cartilage thickness and composition between ACLR patients and matched non-ACLR controls at resting, (2) to investigate how 30 minutes of running influences the aforementioned measures for ACLR patients and controls, and (3) to investigate relationships between running biomechanics and knee cartilage thickness and composition in ACLR patients and controls. Methods: Twenty ACLR patients (age: …

Sleep, Physical Activity, And Sedentary Time In The First Year Postpartum, Erin Elizabeth Kishman

Theses and Dissertations

The postpartum period is a unique time for women, where many women experience changes in sleep and activity patterns. Sleep, physical activity, and sedentary time have all been associated with health outcomes, but there is limited research on how these behaviors change throughout the postpartum period. The purpose of the first aim (Study 1) of this dissertation was to examine trajectories of sleep characteristics in Black and White women during the first year postpartum and to examine if there were any racial differences. The purpose of the second aim (Study 2) was to examine trajectories of the percentage of time …

Mechanisms Of Social Stress Susceptibility And Resilience In Female Rats, Brittany Sara Pate

Theses and Dissertations

Social stress is the most common form of stress humans experience and often precipitates the onset of several comorbidities, including anxiety, depression, post-traumatic stress disorder, and cardiovascular diseases. While many individuals experience social stress and can respond, cope, and recover, some individuals are more likely to develop subsequent health conditions. Importantly, women are particularly susceptible to stress-related disorders, and the prevalence rates for these comorbid conditions are 2-3-fold higher among females compared to males. Epidemiological data suggest that cycling ovarian hormones may play a role in promoting stress susceptibility in females. Therefore, the current studies aimed to examine the effects …

The Role Of Tc-Ptp-Mediated Suppression Of Autophagy During Skin Carcinogenesis, Obed Asare

Theses and Dissertations

Ultraviolet B (UVB) radiation can distort cellular homeostasis and predispose the skin to carcinogenesis. Amongst the deteriorating effects of the sun’s UVB radiation on cellular homeostasis is the formation of DNA photoproducts such as cyclobutene pyrimidine dimers. These photoproducts can cause significant changes in the structure and conformation of the DNA, inducing gene mutations which may accumulate to trigger the formation of skin cancer. Photoproducts are typically repaired by nucleotide excision repair. Notwithstanding, when the repair mechanism fails, apoptosis ensues to prevent the accumulation of mutations and to restore cellular homeostasis. We have identified T-cell protein tyrosine phosphatase (TC-PTP) as …

Biochar Reduces The Pupation And Eclosion Of A Specialist (Manduca Sexta) And A Generalist Pest (Spodoptera Frugiperda), Nischal Wagle

Theses and Dissertations

Chapter 1: This chapter incorporates detailed information about the biochar concept, its production, composition, and properties, harmful arthropods and their damage, the effect of soil on the arthropod community, and the application of biochar on arthropod control.

Chapter 2: The comprehensive lab experiment was conducted with modified pupation media enriched with walnut shell biochar (Chapter II) to evaluate the effects of biochar on the pupation and eclosion success rates of a specialist (Manduca sexta) and a generalist pest (Spodoptera frugiperda). We found that the biochar treatment led to a significant reduction in pupal mass, adult mass, adult wingspan, body length, …

Soil Moisture Dynamics In Cover Cropping Systems: From Local To Global Scales, Manish Gautam

Theses and Dissertations

Cover cropping systems, which have gained recognition for their ability to enhance soil health and promote sustainability are also associated with potential risks related with declining soil moisture and pose a dilemma for farmers considering the adoption of cover crops in water deficit semi-arid settings worldwide. To address this pressing issue, we conducted a participatory cover cropping trial in the Lower Rio Grande Valley (LRGV) region, encompassing four different farms and supplemented this experiment with a meta-analysis to answer our soil moisture and climate parameters and quantify the impact of cover crops on soil moisture levels. The findings revealed that …

Tamaulipan Thornforest Restoration: Factors Influencing Restoration Outcomes And Impacts Of Cover Crops During Replanting, Jerald T. Garrett

Theses and Dissertations

Though the rate of deforestation has slowed in recent years, it remains a primary cause of land cover change within forest ecosystems. The Lower Rio Grande Valley, Texas (LRGV) has lost nearly 95% of its native thornforest since the early 1900’s due to agricultural and urban expansion. The focus of this study is to assess the current vegetative state of restored thornforest sites located in the eastern LRGV and to evaluate the use of cover crops during replanting of native seedlings. Our assessment of restored thornforest sites revealed actively restored sites demonstrated higher overall averages of richness, abundance, and diversity …

Long-Chain Fatty Acid Sensing And Catabolism In Commensal Escherichia Coli Impact Murine Gut Colonization, Tessa Carolina Cox

Theses and Dissertations

The gastrointestinal tract is home to trillions of microbes that collectively influence host physiology, immunity, nutrient metabolism, and infectious disease. The overgrowth of naturally-occurring Escherichia coli in the gut is a common signifier of microbiome dysfunction and occurs in many chronic diseases including obesity. Recent studies have shown that higher fat intake is associated with increased gut E. coli growth. However, it remains unknown whether gut E. coli utilize lipids such as long chain fatty acids (LCFAs) as carbon sources to colonize the mammalian gut. Therefore, the central objective of my dissertation was to utilize bacterial genetics and various mouse …

The Impact Of Progerin On Genome Maintenance In Mammalian Cells, Liza Alexandra Joudeh

Theses and Dissertations

Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare genetic condition characterized by accelerated aging. The cause of HGPS is a point mutation in the LMNA gene, which encodes lamins A and the splice variant lamin C. Lamins are components of the nuclear lamina, a complex that plays structural and catalytic roles in the nucleus that are essential to chromatin organization, DNA replication, and DNA repair. The mutation associated with HGPS activates a cryptic splice donor site which alters the lamin A protein in a way that does not allow prelamin A to be fully processed, and ultimately results in the accumulation …

Molecular Mediators Of Axonal Transport And Local Translation Of Cdc42, Rhoa Molecular Mediators Of Axonal Transport And Local Translation Of And Calreticulin Mrnas And Their Implications For Axon Growth And Regeneration, Matthew Davis Zdradzinski

Theses and Dissertations

Neurons are highly polarized cells with expansive cytoplasmic processes, axons and dendrites, which create unique subcellular domains. Localization and translation of mRNAs in these subcellular regions is now recognized as a critical mechanism through which polarized cells establish and maintain the specialized domains that are needed for their functions. RNA profiling studies have uncovered hundreds to thousands of mRNAs in axons and these axonal mRNA profiles differ across neuronal populations, physiological conditions, and developmental growth states. Functionally organizing these mRNA populations into cohorts of coregulated mRNAs via RNA binding proteins allows us to better understand how the transcriptome is regulated …

The Effects Of Variations In Light And Nutrient Availability On Phytoplankton And Zooplankton, Jake Anthony Swanson

Theses and Dissertations

Aquatic ecosystems experience a wide range of variation in resource availability; two of the resources that are most essential to phytoplankton and zooplankton are light and nutrients. Light can vary in both its color and intensity; these variations can directly impact phytoplankton by altering the amount and color of light available for photosynthesis. Nutrient variability, particularly increases in nutrient levels, also alter phytoplankton communities by favoring the growth of certain taxa such as cyanobacteria.

To understand whether phytoplankton respond differently to changes in light availability I investigated whether the diversification of cryptophytes, phytoplankton with diverse light-capturing pigments, showed evidence of …

Modulation Of Eif2Α Signaling And The Integrated Stress Response By Targeted Therapeutic Attenuation Of Pkr Activity Contributes To Protection Of Dyt-Prkra Cells From Apoptosis, Kenneth L. Frederick

Theses and Dissertations

Luteolin is a natural flavonoid present in vegetables, fruits, and medicinal herbs that possesses anti-oxidative, anti-cancer, and anti-inflammatory properties. In this study, we investigated the effect of luteolin on the integrated stress response (ISR), which is an evolutionarily conserved intracellular signaling network essential for adapting to environmental stresses to maintain healthy cells. Dysregulated ISR is involved in the etiology of many human diseases including the movement disorder DYT-PRKRA which is caused by mutations in the PRKRA gene. PRKRA encodes for PACT, the protein activator of interferon-induced, double-stranded RNA (dsRNA)-activated protein kinase PKR.PACT-mediated PKR activation regulates the …

Predictors Of Driving Performance Post-Stroke, Halle Elise Prine

Theses and Dissertations

Driving is a complex skill involving the interaction of various brain functions, making it challenging to determine the independent contributions of each process to driving proficiency. While past studies have identified assessments such as the Useful Field of View Test (UFOV) and the Trial Making Test (TMT) as strong predictors for driving skills, little research has explored the impact of visual search and movement inhibition on driving after stroke. This cross-sectional study includes participants between the ages of 21 to 80 years with residual disability caused by a unilateral middle cerebral artery stroke at least six months prior. The participants …

Effects Of Caffeine On Measures Of Clinical Outcome And Recovery Following Mild Traumatic Brain Injury In Adolescents, Jacob Michael Eade

Theses and Dissertations

OBJECTIVE: The overarching purpose of this study was to investigate the influence of habitual caffeine consumption on mTBI outcomes in adolescents. BACKGROUND: Adolescents who suffer an mTBI have an increased risk for neurological impairment and symptomology. Thus, it is important to elucidate modifiable lifestyle factors that have the potential to influence injury outcomes and recovery. Caffeine is a legal psychoactive compound prevalent among the adolescent population. Marketed as an ergogenic aid caffeine coincides with recreational activities where incidence of mTBI is high. However, no human study has explored the influence of caffeine consumption on mTBI pathology. It was hypothesized that …

The Role Of Environmental Context In Supporting Children’S 24- Hour Movement Behaviors; A Positive Deviance Perspective, Roddrick Dugger

Theses and Dissertations

Background: During summer, children display less favorable movement behaviors than the school year. To investigate the role of environmental context in supporting children’s ability to meet the 24-hour Movement Guidelines (i.e., Moderate-to-Vigorous Physical Activity: ≥ 60 minutes, Sleep duration: 9-11 hours, Screen Time: ≤ 2 hours), this dissertation had three primary aims: 1) Utilize the Positive Deviance Framework to identify unique practices and resources that enabled children to meet guidelines, 2) Examine potential associations between the neighborhood built and social environment with movement behaviors by household poverty experience, and 3) Identify specific features of the family and home environment that …

Comparative Analysis Of Soil Properties, Microbial Community Composition, And Yield Responses To Cover Crops In Different Ecoregions Of South Texas, Daphne Zapsas

Theses and Dissertations

Comprehensive understanding of soil properties, their interdependencies, and the effects of management practices is crucial for designing sustainable agricultural strategies. By adopting site-specific and need-based practices that enhance soil health, farmers can optimize crop growth, increase yield, and contribute to long-term environmental sustainability. Cover crops have been recognized for enhancing soil fertility, promoting microbial activity, and increasing organic matter content. However, while their effectiveness is well documented in temperate regions with readily available water, their impact in water limited systems in subtropical regions remains mixed. The aim of this study is to assess soil conditions in four different farms across …

Cover Crops Influence Arthropod Community Dynamics Through Seasonal Variation And Cascading Effects, Adegboyega Fajemisin

Theses and Dissertations

Chapter 1: This chapter gives an overview of how cover crops influence soil’s physical, chemical, and biological properties, and their role on mediating arthropod community dynamics with implications for pest management in the subsequent cash crop.

Chapter 2: This chapter examines the effects of cover-cash crop rotation on arthropod community dynamics on four growers fields in the Lower Rio Grande Valley, Texas. We assessed the impact of cover crops planted in the summer months on the subsequent cash crops planted in the winter. Our results showed that cover crops had a differential effect on the population of beneficials and herbivores …