Digital Commons Network^™

Mapping Renewable Energy Opportunities: Increasing Rural Energy Resilience In Mississippi Through Extension And National Program Insights, Kaitlyn Brooke Gordon

Theses and Dissertations

There has been an increased interest in renewable energy opportunities in Mississippi in recent years but limited educational material on this topic and a lack of knowledge among residents on various renewable energy options. Therefore, the main objectives of this study were to 1) conduct a comprehensive review of renewable energy educational resources and 2) increase knowledge of renewable energy in youth through the development of a new statewide Extension program. The environmental scan resulted in 45 usable responses from 117 potential participants, and programmatic details were received for 54 Extension programs or other forms of educational material. Evaluation results …

Evaluation Of Soil Steaming, Cover Crops, And Allelopathy: An Integrated And Sustainable Weed Management Strategy In Sweetpotatoes, Alaina Marie Richardson

Theses and Dissertations

Yellow nutsedge (Cyperus esculentus L.) is a persistent weed in sweetpotato and vegetable cropping systems caused by its aggressive growth habit and limited control options. The present study assessed two alternative, chemical-free methods: steaming the soil and the use of allelopathic cover crops. Greenhouse and field experiments showed that steaming suppressed the germination of yellow nutsedge effectively and that treatments for 45 min provided the highest control of all the soil depths tested (100%). A leachate experiment examined the allelopathy of five cover crops against yellow nutsedge and showed that buckwheat and cereal rye had the largest reductions in shoot …

Soil Ethics In Practice: Harvesting Conservation Choices Among Puerto Rican Coffee Farmers, Patricia Marie Cordero-Irizarry

Theses and Dissertations

Coffee farming in Puerto Rico has declined over recent decades, partly due to deteriorating soil quality. However, the decision-making process behind farmers’ adoption of soil conservation practices remains unclear, particularly the overlooked role of soil ethics, which emphasizes the moral principles guiding human relationships with the soil. This mixed-methods study examined coffee farmers’ adoption of soil conservation practices by integrating the Values-Beliefs-Norms (VBN) theory and a newly developed Soil Ethics Survey (SES) instrument for the quantitative component, while using Decision-Making Theory and Social Cognitive Theory to qualitatively explore how farmers’ experiences and reflections shape their soil ethics. Quantitative findings revealed …

Evaluating The Impacts Of Cover Crops At Different Nitrogen Rates On Soil Microbial Dynamics Within A Sweetpotato Production System, Lahari Nekkalapudi

Theses and Dissertations

A field study was conducted from 2023 to 2024 at Pontotoc, Mississippi, to evaluate the effects of cover crops and nitrogen (N) fertilizer on soil microbial communities in sweet potato production. The study followed a randomized split-block design with three cover crops (Clover, Wheat, and Fallow) and three N rates (0, 50, and 100 lb N acre⁻¹), each replicated four times. Soil samples were collected at cover crop termination, sweet potato planting, and harvest. Bacterial and fungal communities were analyzed using Illumina HiSeq sequencing. Soil properties such as total carbon, total nitrogen, pH, POXC, and microbial activity (AWCD) were also …

Optical Trapping For The Study Of The Chemical And Physical Dynamics Of Single Particles, Yukai Ai

Theses and Dissertations

This dissertation explores the combined technique of optical trapping and Raman spectroscopy (OT-RS) to study the physical and chemical properties, as well as the dynamic surface changes, of single aerosol particles in air. The study covers a wide range of aerosol types, including bioaerosols (such as pollen, bacteria, and fungi), dust particles (such as black carbon, terrestrial, and extraterrestrial materials), and liquid droplets (such as sea-spray aerosols). The optical trapping system used in this work is based on the universal optical trap (UOT), which is capable of trapping and manipulating a wide variety of particle types. These include both transparent …

Recreation Effects On Soil Carbon, Biocrust Presence, Soil Stability, And Invasive Species In Indian Creek, Bears Ears National Monument, Elisabeth M. Currit

Theses and Dissertations

Desert ecosystems perform essential ecosystem services, including playing a crucial role in the global carbon cycle. Because of this, it is important to understand how recreational activities, common in desert environments, impacts dryland ecosystems' ability to perform ecosystem services. The growing popularity of outdoor recreation in Western US poses a threat to desert ecosystems, and unregulated activities can harm soil health, particularly the presence and functioning of biological soil crusts (biocrusts). This study uses the Indian Creek Special Recreation Management area in Bears Ears National Monument, Utah, USA, as a case study for recreation impacted desert ecosystems. It examines the …

Coding For Nonstandard Channels: A Capacity-Oriented Approach, J Daniel Harman

Theses and Dissertations

This work addresses the issue of coding for non-standard channel models with an emphasis on capacity-oriented channel analysis and system design. The first channel studied is the Wyner wiretap channel. Channel sounding results were obtained to calculate the capacity for the multi-antenna case of the Wyner wiretap channel to ascertain the potential for secure communication via secrecy coding. The second channel studied is an asymmetric binary crossover erasure channel (ABCEC) with a short-blocklength constraint. The capacity for this channel was derived, and linear codes were chosen and tested. Another study was conducted on the ABCEC within a degraded wiretap channel …

Exploring Soil-Derived Antimicrobials For Inhibiting Dairy-Associated Pathogens And Spoilage Bacteria, Michael Joseph Moran

Theses and Dissertations

Spore-forming bacteria are among the most problematic contaminants in fluid milk. They can survive pasteurization, grow at refrigeration temperatures, and secrete heat-stable enzymes, making them a major cause of spoilage in both pasteurized and reconstituted milk products. Current nonthermal strategies for reducing spore counts, including microfiltration and bactofugation, are often costly and inconsistent. The increasing consumer demand for natural additives in food products has sparked interest in the use of bacterially-derived antimicrobial compounds, particularly those from generally recognized as safe (GRAS) organisms, as an alternative method of dairy preservation. This study explores the antimicrobial potential of ten soil-derived Bacillus and …

Opposing Roles For Iron Transport Systems In Gallium Tolerance In Extraintestinal Pathogenic Escherichia Coli, Nagama Parveen

Theses and Dissertations

Iron is required for bacterial growth because it serves as a co-factor for enzymes involved in DNA synthesis, cellular respiration, and other processes. Disrupting bacterial iron homeostasis is an effective strategy to prevent the growth of antibiotic-resistant bacteria, and gallium (Ga³⁺) has emerged as a promising candidate due to its ability to displace iron (Fe³⁺) and prevent essential iron-dependent pathways. However, Escherichia coli are naturally less sensitive to gallium than many other bacteria, and the mechanisms that control gallium tolerance are not completely understood. To address this, we performed a genome-wide transposon sequencing (TnSeq) screen to identify genes important for …

Classification And Analysis Of Families Of Graphs With Focus On Nordhaus-Gaddum Bounds, Sibi Pranav Muthuprakash

Theses and Dissertations

Nordhaus-Gaddum type problems focus on bounding characteristics of graph and its complement. There are certain families of graphs which yield optimal upper bounds on various Nordhaus-Gaddum characteristics of graph. In this paper, we will talk about bounding combinatorial algebraic connectivity, normalized algebraic connectivity, the Cheeger constant, and the isoperimetric number of a graph and its complement. We will identify some optimal or near optimal families of graphs and conduct an analysis on these families that will help to bound these characteristics. We will also prove and conjecture some bounds that can help in formulating stronger bounds on these characteristics of …

Understanding Administrator Approaches To Trauma-Informed Care: Findings From A Mixed Methods Study, Megan Coalwell

Theses and Dissertations

Traumatic events during childhood have been termed adverse childhood experiences (ACEs). Experiencing traumatic events or ACEs is common for school-aged children. Research reports indicate that as many as two out of three children will experience at least one traumatic event by the time they are eighteen. The negative effects of experiencing trauma are well documented. Trauma can lead to long-term outcomes in adults such as chronic health problems, mental health problems, substance misuse, and even early death. During childhood, it can lead to internalizing and externalizing problems, as well as difficulties in school. Trauma-Informed Care (TIC) is an approach to …

An Active Quasi-Circulator Ic And Technique For 1-255 Mhz Resonance-Based Spectroscopic Impedance Plethysmography, Sharisse Poff

Theses and Dissertations

Impedance measurement is a promising avenue for noninvasive glucosemonitoring. Specifically,resonance-basedimpedancemeasurements exhibit good correlation with glucose levels at excitations from tens of MHztoover 100 MHz. Additionally, plethysmographic impedance measurements are needed to separate arterial blood signals, which contain strongerglucose information, frominterstitialfluidsignals. Weanticipate that plethysmographic measurements across a range of frequencies— spectroscopic plethysmography—at excitations from tens to over 100 MHz could enable resonance-based monitoring with higher selectivity for arterial glucose than previous work. Afour-point impedance measurement circuit is designed, and its ability to measure constant and periodically time-varying impedance is demonstrated. This circuit presents high impedance to the device-undertest (DUT), which fails …

Inhibitory Control In Asian Elephants, Gillian Schmitt

Theses and Dissertations

Inhibitory control is defined as the ability to suppress a prepotent motor response in favor of a more efficient or advantageous behavior, and is an important core executive function. Although elephants are known to behave flexibly and display other executive functions, there is currently little information available on if, and to what extent, they display inhibitory control. We tested 16 captive Asian elephants (Elephas maximus) (N = 8 males, 8 females) ranging in age from 4-years-old to 60-years-old at the National Elephant Institute in Thailand using a classic detour paradigm adapted to be more ecologically salient for them through the …

Intergenerational Transmission Of Health: Evidence From Indonesia, Fatima Khan

Theses and Dissertations

This study estimates the causal transmission of health from mothers to their children. Intergenerational associations in health and other human capital outcomes are well established, but those associations may not be causal due to common unobserved factors between a mother and her child. This study employs two-stage least squares, using weather variation as an instrument, to causally identify the relationship between maternal health and child health outcomes in five dimensions: height-for-age, self-reported health, blood pressure, lung capacity, and hemoglobin levels. The data are from the Indonesian Family Life Survey (1993--2014), a longitudinal survey that provides a 21-year look into the …

The Effect Of An Invasive Species (Lantana Camara) And A Fast-Growing Herb (Acanthus Pubescens) On The Plant And Animal Communities In Kibale National Park, Uganda, Kathleen Bufka

Theses and Dissertations

Fast-growing plant species, like Lantana camara and Acanthus pubescens, could threaten biodiversity in Kibale National Park, Uganda. I surveyed plants and wildlife in areas where these plants were frequently encountered compared to those areas where they are infrequent. I found mixed results based on plant traits and the animals considered. My findings support management efforts on these two species to prevent forest degradation.

Acute Exposure Of American Oyster (Crassostrea Virginica) To Selected Antidepressant Drug: Histological, Biochemical, And Immunohistochemical Assessments, Md. Faisal Amin

Theses and Dissertations

The rapid increase in pharmaceutical use has brought significant health benefits to humans. Studies have shown that many pharmaceuticals, such as antidepressants, are often detected in surface waters, groundwater, and even drinking water. These pharmaceuticals in aquatic environments threaten marine life seriously. Marine bivalves are vital source of seafood for people worldwide. In this study, we examined the effects of short-term exposure to fluoxetine, an antidepressant used to treat depression, at low (0.5 μg/L) and high (5 μg/L) doses over a one-week period on American oysters (Crassostrea virginica) under controlled laboratory conditions. Histological analysis revealed atrophy in the gills and …

Exploring Intra- And Interpersonal Connection Through Mindful Moments At A Hispanic-Serving Institution, Yvette Angeline

Theses and Dissertations

The demands of contemporary education have contributed to high levels of stress, anxiety, and burnout among educators (Barton, 2019; Hidajat et al., 2023; Walker, 2022), uncovering a need for pedagogical approaches that prioritize holistic well-being and humanize the learning experience (Palmer, 2009; Salazar, 2013; Wong & Mishra, 2020). This qualitative case study investigates how moments of mindfulness, integrated as curricular practice within a teacher education program at a Hispanic-Serving Institution (HSI), nurtures pre-service teachers’ awareness of the self and world. This study explores aspects of mindfulness from its Eastern origins (Thich Nhat Hanh, 1975) and its Western secular applications (Jon …

Assessment Of Floral Resources From Three Tamaulipan Thornscrub Communities Of The Lower Rio Grande Valley, Gracie Makenna Granados

Theses and Dissertations

The Tamaulipan thornscrub is a transition zone between the neotropics and the temperate regions, harboring high biodiversity. This habitat supports a diverse insect community, including many pollinators of native and cultivated plants in Texas and northeastern Mexico. This ecosystem has been extensively degraded and lost; only 5% of its original cover remains north of the Rio Grande. Restoration of the Tamaulipan thornscrub has been ongoing for over three decades, but the important roles of pollinators in the success of such efforts and the functioning of the restored ecosystem have rarely been considered in restoration efforts. The purpose of this study …

Bilateral Leading Edges With Tubercle Modifications: An Experimental Study, Roberto Sanchez

Theses and Dissertations

The increasing demand for better performance and maneuverability from airfoils to sustain superior performance over a wide range of platforms, including vehicles, propellers, and wing designs, continues to grow. Researchers have drawn inspiration from nature, looking at birds of prey, dragonflies, and humpback whales for aerodynamic improvements. Among these, tubercle airfoils, inspired by the humpback whale’s flipper, have gained increasing interest. This experimental study presents the results of bilateral tubercle leading-edge airfoils based on a modified NACA 0018 design with a chord length of 1.82 inches, a span width of 7.5 inches, and an amplitude of 6.3c%. Five configurations were …

Development Of A Wearable Biosensor For Cortisol Detection In Human Sweat Utilizing Pani/Peo Polymer Blend And Nitrogen-Doped Graphene Quantum Dots, Cesar Sanchez

Theses and Dissertations

Since the development of the first biosensor in 1962, the evolution of commercially available wearable biosensors has been driven by an increasing consumer interest in real-time health tracking. However, challenges related to sensor sensitivity and cost have hindered progress. Deploying a novel approach, the biosensor integrates a blend of Polyaniline (PANi) and Polyethylene Oxide (PEO) along with Nitrogen-doped Graphene Quantum Dots (N-GQDs) to enhance sensitivity and electroactivity, crucial for cortisol detection. To optimize performance, three distinct synthesis methods for N-GQDs; hydrothermal, microwave, and hot plate synthesis were compared employing a bottom-up approach utilizing citric acid (CA) as the primary reactant …

The Impact Of Positive Psychology Use Upon Gls Outcomes For People With Chronic Pain Syndromes, Timothy Michael Curtis

Theses and Dissertations

The essence of being human is realized by our discovery of meaningful purpose throughout each important stage of our lives. If we perceive that we lack this meaningful purpose in our lives, it could become a distressful source of suffering to our sense of well-being emotionally, cognitively and perhaps, spiritually. A strong indicator of well-being comes from a good evaluation we ascertain as to how well we believe outcomes in our lives are consistent with our goals and values, which is also known as satisfaction with life. Research findings indicate that the more someone experiences repeated negative life events, the …

Arginine Vasotocin And Corticosterone In Nesting And Non-Nesting Loggerhead Sea Turtles In X’Cacel-X’Cacelito Sanctuary, Krista Blair Reed

Theses and Dissertations

Sea turtles exhibit distinct behaviors before and after egg laying, however, not all individuals successfully oviposit. Some females display disruptions in their typical nesting behavior, returning to the water without laying eggs, which is referred to as a non-nesting emergence (NNE). NNEs can be due to external disturbances on the beach, but why they occur is often unclear. Arginine vasotocin (AVT) is a neuropeptide involved in various physiological processes, including stimulating smooth muscle contraction of the oviduct to facilitate egg deposition in nesting sea turtles. On the other hand, corticosterone is the primary stress hormone in sea turtles and is …

Exploring Transcriptional Stress Responses In Sorghum And Evolutionary Insights Into Yth Domain Proteins Across Plants, Shikha Bharti

Theses and Dissertations

Understanding how plants respond to abiotic stress is crucial for enhancing crop resilience in the face of climate change. This thesis explores plant stress adaptation mechanisms through two interlinked studies that address different aspects of gene regulation. The first study investigates the transcriptional dynamics of Sorghum bicolor under drought and heat stress at 1-hour and 6-hour time points. By employing 3'-end RNA sequencing, this study provides a comprehensive temporal view of gene expression changes, revealing stress-responsive transcription factors, hormone-associated pathways, and chromatin regulators. The comparative analysis highlights both common and distinct molecular responses between drought and heat stress, providing insights …

Biological, Histological, And Immunohistochemical Responses To Heat Stress In Common Goldfish, Carassius Auratus, Ngozichukwu Francis Ngozichukwu

Theses and Dissertations

Global climate change has led to rising temperatures, posing significant challenges to aquatic ecosystems and the health of ectothermic species such as goldfish (Carassius auratus) This thesis investigated the effects of heat stress on growth performance, histological alterations, and molecular stress responses in the gill and kidney tissues of goldfish Fish were exposed to control (24°C), medium (28°C), and high (32°C) temperatures for two weeks Growth parameters, including instantaneous growth rate (IGR), absolute growth rate (AGR), body value gain (BVG), and condition factor, were evaluated alongside histological and immunohistochemical markers of stress Results revealed that high temperature significantly reduced AGR …

Analyzing How Taste And Nutrition Impact Learning And Memory In Honey Bees Through Olfactory Associative Conditioning, Alessandra Elizabeth Perry

Theses and Dissertations

Honey bees detect sweet nectar, but not all sweet-tasting sugars provide nutrition. Unlike fruit flies, which can learn to avoid non-nutritious sweet foods, bees may lack this ability. To test if bees form caloric frustration memory (CFM), we conditioned them using odors paired with L-glucose (sweet but non-nutritious) or D-glucose (sweet and nutritious). Bees rewarded with L-glucose showed lower learning and long-term memory compared to D-glucose. Bees cannot differentiate between an odor associated with rewards containing malaise-causing compounds and an odor associated with a reward alone during differential conditioning. Therefore, we used differential conditioning to determine if lower acquisition in …

Transcriptomic Study On The Effect Of Salt Stress In Sorghum Bicolor Seedlings, Joshwa A. Gandy

Theses and Dissertations

The global impact and reliance on cereal crops, and sorghum in particular, is paramount for worldwide food security and for the livelihood of hundreds of millions of people. The detrimental effects of salt stress on crop plants and the huge economic losses it causes by affecting agricultural output worldwide is a devastating issue with huge impacts, which have prompted research to combat salinity in numerous ways. Understanding how cereals respond to the negative effects of salt stress is crucial for enhancing their salt tolerance. In this study of sorghum, we used a 3’-end RNA sequencing approach to elucidate major salt …

Interdigitated Gear-Shaped Screen-Printed Electrode Using G-Pani Ink For Sensitive Electrochemical Detection Of Stress Related Hormones Dopamine And Cortisol, Pritu Parna Sarkar

Theses and Dissertations

This research introduces a novel interdigitated gear-shaped graphene-based electrochemical biosensor for the simultaneous detection of dopamine (DA) and cortisol. Modified with graphene–polyaniline (G–PANI) conductive ink, the sensor increased active surface area—94.52% and 57% higher than Metrohm DropSens 110 and circular printed sensors, respectively. Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy and X-ray diffraction (XRD) were employed for physicochemical characterization. The sensor detects dopamine and cortisol over a linear range of 0.1–100 µM, with limits of detection of 0.043 µM (R² = 0.98) and 0.0577 µg/mL (R² = 0.976), respectively, in phosphate-buffered saline (PBS) using redox probe. Electrochemical performance …

Opa1-Mediated Mitochondrial Dynamics In Myogenic Differentiation Of C2c12 Myoblasts, Daniel Eloy Bazan

Theses and Dissertations

Mitochondria play a pivotal role in metabolic energy production, cellular signaling, and apoptosis. To carry out these key cellular roles, mitochondria dynamically balance their organization through opposing including fusion and fission processes. The balance between mitochondrial fusion and fission is regulated by key proteins such as OPA1 (optic atrophy 1) and OMA1 (overlapping activity with metalloprotease). More recently, mitochondria have been increasingly revealed to play key roles in cellular differentiation, where metabolic demands are reprogrammed. This study aims to elucidate the specific roles of OPA1 and OMA1 in the differentiation of C2C12 myoblast cells into myotubes.

Our data demonstrates that …

Machine Learning Applications For Evaporation Predictions From Small Reservoirs: Potential Water Savings For Lower Rio Grande Valley, Texas, Syed Muhammad Fahad Abdullah

Theses and Dissertations

Local-scale reservoirs are important to regional water balance, but these are often overlooked. This study presents a robust machine learning (ML) approach leveraging reanalysis datasets to estimate daily evaporation for local-scale reservoirs in semi-arid South Texas. Selected models were trained with daily lake evaporation model (DLEM) estimates and used climatic and reservoir-specific properties as feature input variables. The multi-reservoirs training approach ensured applicable model generalization. Results show promising predictive performance with R² values ranging from 0.55–0.67 (testing) and 0.64–0.78 (validation), NSE values ranged from 0.54 0.67 (testing) and 0.64–0.78 (validation), and RMSE values ranged between 1.52–1.80 mm/day (testing) and 1.22–1.58 …

Phenotypic Plasticity In Response To Abiotic Factors In Silverleaf Nightshade (Solanum Elaeagnifolium), And The Effectiveness Of North American Lacebug (Gargaphia Arizonica Drake And Calvo) As A Biocontrol, Marco Andre Silguero

Theses and Dissertations

Silverleaf nightshade (Solanum elaeagnifolium) is a widespread invasive weed in South Texas and other arid regions, where it reduces crop productivity, competes with native vegetation, and resists conventional control methods. Its ability to thrive across different environments is linked to phenotypic plasticity, allowing it to adjust growth and physiology in response to light and water availability. In this thesis, I examine the role of plasticity in S. elaeagnifolium under field conditions and evaluate the potential of the North American lacebug (Gargaphia arizonica) as a biological control agent. Field observations were used to measure plant traits such as height, stem thickness, …