Digital Commons Network^™

Reassessing Nitrogen Management For Maize Production In Mississippi, Camden Dawson Oglesby

Theses and Dissertations

12 N treatments in 2020 and 11 in 2021 were replicated four times over four locations in a randomized complete block design. The first research tested the efficacy of CYG for Mississippi corn (Zea mays L.) production. The optimum N rates were calculated by fitting four models. Differences between the CYG rate and AONR were compared. AONR varied from 134 to 301 kg N ha–1 at different management levels. When we compared the AONR to the CYG rate, the CYG rate over-recommended N in 12 of the 14 possible comparisons. The second study compared different VIs, methods, and sensors at …

Alteration Of The Viral Immune Response In The Lung Of Juvenile Rats By Cannabidiol, Kylee J. Burroughs

Theses and Dissertations

Cannabidiol (CBD) has unverified use in the treatment of ADHD but parents are giving CBD to their children to treat hyperactivity and restlessness. CBD has suppressive effects on immune function therapeutically but the effect of pre-exposure to CBD on the response to an immune challenge is unknown. To investigate this, male and female juvenile rats were treated orally with either corn oil or 20 mg/kg or 60 mg/kg CBD daily for 5 days followed 24 hours later by intranasal challenge with a viral mimic, Resiquimod (R848). After 6 hours, lungs were collected for the analysis of gene expression of select …

Evaluation Of Warm Season Vegetables Using Sustainable Production Practices, Jacob Arthur

Theses and Dissertations

Sustainable practices were evaluated for the production of two warm season vegetable crops, tomato and chile peppers. The first study investigated the plant vegetative growth, fruit production timing, yield components and fruit quality of three hybrid and three heirloom tomato cultivars grown in a high tunnel using grafted and non-grafted plants. Grafting the selected tomato cultivars with the two rootstock types did not alter total marketable yield of any cultivar, but affected overall stem diameter, fruit color, and β-carotene concentrations of tested tomato cultivars. The second study evaluated the plant growth, yield, and fruit quality of nine heirloom chile pepper …

Design And Synthesis Of Novel Donor-Acceptor-Donor Xanthene-Based Dyes From Heteronuclear Ring Systems For Chemical, Electrochemical, And Biological Sensory Materials, Ishanka Nirmani Rajapaksha

Theses and Dissertations

Conventional xanthene dyes (eg: fluorescein and rhodamine) have their absorptions and emissions in the visible region, which limits their use in cellular imaging. Absorptions and emissions at longer wavelengths allow for low background cellular autofluorescence, deep tissue penetration, and minimum cell damage. Chapter I discusses the background of fluorescent dyes and the importance of near-infrared (NIR) emissive dyes for biological applications. Chapter II is based on the design and synthesis of new xanthene-based NIR I dyes using simple and short synthetic routes. This study used pyrrole and indole as donor molecules and combined them to the xanthene core by the …

Seasonal Trends And Sampling Time Of Day On Overall Microbial Population And Indicator Organisms In Catfish Parts And Catfish Processing Environment, Maria Gabriela Hidalgo-Sindoni

Theses and Dissertations

Commercial production of catfish is the leading aquaculture industry in the United States. Production in Mississippi, Louisiana, Alabama, and Arkansas representing 96% of the total catfish sales in the USA. In 2017, the USDA-FSIS added testing of generic Escherichia coli and Enterococcus to the sampling of Siluriformes. The incidence of Escherichia coli in fish and seafood has been associated with possible fecal matter contamination. However, this indicator bacteria could also be a part of the natural microflora of catfish ponds where processing plants collect hybrid catfish. Aerobes, Psychrotrophs, Coliforms, Escherichia coli, and Enterobacteriaceae counts among environmental, liquid and fish …

Inequity Of Access Across America: A Spatial, Temporal, And Modal Disparity Analysis, Sanju Maharjan

Theses and Dissertations

The overarching goal of this dissertation is to examine the spatial, temporal, and modal disparity of access across America. This is achieved by posing three research objectives. The first objective determines the spatial and temporal disparity of transit and automobile access gap, its impact on transit use, and its socioeconomic and built environment correlates. The second objective examines the spatial and temporal disparity of slightly and extremely risky bike infrastructure and measures the social inequity of access to bike infrastructure. The third objective indicates spatial transit access mismatch between high- and low-wage employment across metropolitans. Three findings are discerned. First, …

Mitigating The Shrink-Swell Capacities Of The Yazoo Clay Through Application Of Lime And Biochar, Austin Alan Brister

Theses and Dissertations

Shrinking and swelling in Yazoo Clay is a cause of concern for construction projects in Mississippi. This thesis investigated the effects of adding lime and Douglas Fir biochar on the shrinking and swelling capabilities of Yazoo Clay. Samples of Yazoo Clay were mixed with the additives in defined ratios and subjected to the free swell test and the COLE(rod) test. Biochar addition reduced the COLE(rod) of the samples a large amount, while increasing the swelling potential of the clay samples. The addition of lime slightly reduced both the shrinking and swelling potentials of the samples. The mineralogical variability of Yazoo …

Dynamics Of Redox-Driven Molecular Processes In Local And Systemic Plant Immunity, Philip Berg

Theses and Dissertations

The work here presents two main parts. In the first part, chapters 1 – 3 focus on dynamical systems modeling in plant immunity, whereas chapters 4 – 6 describe contributions to computational modeling and analysis of proteomics and genomics data. Chapter 1 investigates dynamical and biochemical patterns of reversibly oxidized cysteines (RevOxCys) during effector-triggered immunity (ETI) in Arabidopsis, examines the regulatory patterns associated with Arabidopsis thimet oligopeptidase 1 and 2’s (TOP1 and TOP2), roles in the RevOxCys events during ETI, and analyzes the redox phenotype of the top1top2 mutant. The second chapter investigates the peptidome dynamics during ETI …

Disease Resistance And Productivity In Genetically Improved Loblolly Pine: Results From A Resistance Screening Trial And A Midrotation Comparison Of Genetic Improvement Levels, Stephen W. Goodfellow

Theses and Dissertations

Decades of tree improvement has resulted in genetic gains in loblolly pine productivity, form, and resistance to fusiform rust. The goal of this study was to advance the understanding and applied use of genetic improvement by analyzing inter- and intra-provenances hybrids’ rust resistance and evaluating midrotation performance of varying levels of genetically improved stock types. The first study compares 16 seedlots at the USDA Resistance Screening Center and evaluates rust resistance of controlled-pollinated inter- and intra-provenances crosses, and openpollinated seedlots from three provenances: Western Gulf, Atlantic Coastal, and Interior Piedmont. Post inoculation, one Coastal OP seedlot was resistant and ten …

Evaluating The Impacts Of Waterlogging Stress On Cowpea (Vigna Unguiculata L.) Growth Traits And Physiological Performance, Omolayo Joshua Olorunwa

Theses and Dissertations

The progressive increase in the global population and the rapidly changing climate have put unprecedented pressure on crop production. Cowpea is one of the world’s most important leguminous crops, contributing to food security and environmental sustainability. However, cowpea productivity is limited due to waterlogging stress. The main objective of this study was to explore physiological and biochemical mechanisms to understand how cowpea genotypes respond to waterlogging stress. Four studies were conducted in controlled and field conditions to achieve these objectives. Study 1 characterized the waterlogging tolerance of 30 cowpea genotypes in a controlled environment using 24 morphophysiological parameters with waterlogging …

United We Stand? Investigating The Impact Of Unified Dues Agreements Between State And National Career & Technical Education (Cte) Professional Organizations On Cte Funding In The Southern States, Justin Ryan Hall

Theses and Dissertations

Career and Technical Education (CTE) teachers have long been active in lobbying the federal and state governments in support of CTE through their professional organizations, but these are not traditionally considered interest groups. This study sought to determine if the formal relationships—dues agreements—between the two largest national professional organizations, and their state affiliates had an impact on state funding for CTE. The impacts of professional organization unity, membership rates, and lobbying expenses on state-level CTE funding were analyzed through the lens of interest group theory, a subfield of political science. Within this population (N = 13), 1) a link …

Mapping Forest Structure In Mississippi Using Lidar Remote Sensing, Nitant Rai

Theses and Dissertations

This study aimed at evaluating the agreement of spaceborne Light Detection and Ranging (lidar) ICESat-2 canopy height with Airborne Laser Scanning (ALS) derived canopy height to inform about the performance of ICESat-2 canopy height metrics and understand its uncertainties and utilities. The agreement was assessed for different forest types, physiographic regions, a range of percent canopy cover, and diverse disturbance histories. Results of this study suggest that best agreements are found using strong beam data collected at night for canopy height retrieval using ICESat-2. The ICESat-2 showed great potential for estimating canopy heights, particularly in evergreen forests with high canopy …

Numerical Study Of Advanced Solar Receiver Tubes Based On A Coupled Thermo-Mechanical Analysis For Concentrated Solar Power Tower Plant, Shawn Michael Hatcher

Theses and Dissertations

The search for more sustainable energy to match the growing energy demand begins with finding more dispatchable resources such as solar energy. As one of the promising solar technologies, concentrated solar power (CSP) has a full capacity to store thermal energy for extended operation. Nevertheless, some key components in CSP systems usually face extreme environment, such as uneven solar flux, cyclic thermal expansion, structural degradation on the solar absorber tubes in a Concentrated Solar Power Tower (CSPT) Plant. In this study, we applied Multiphysics simulation to explore the benefits of introducing optimized fins for heat transfer enhancement and uniform temperature …

Developing An Early Life Cycle Manufacturability Assessment For Conceptual Designs, Tonya Gamblin Mccall

Theses and Dissertations

Studies have shown that 70 – 80% of a product's life cycle costs are committed by the end of the product design phase (Anderson, 2014; National Research Council, 1991; Swift, 1987). This supports the general claim that decision making in the conceptual stage drives the cost throughout the life cycle. The use of concurrent engineering has been viewed as the answer to this problem, offering the Design for Excellence (DFX) as one approach for evaluating product designs across specific disciplines. This research focuses on a subset of DFX referred to as Design for Manufacturability to develop a means to assess …

The Chemistry And Catalytic Activity Of Dehydrogenative Silylation And Hydroboration Of Complexes Bearing Semirigid Ligands With Group 14 Elements, Niroshani S. Abeynayake

Theses and Dissertations

Incorporation of silicon in the ligand backbone would yield electron-rich metal complexes upon coordination to transition metal complexes. The coordination chemistry of semirigid benzyl phosphines bearing a single or multiple phosphorus atoms and varying number of Si−H moieties has gained interest in recent years. This dissertation focuses on synthesizing silyl and germyl transition metal complexes of groups 9 and 10. Chapter II presents the synthesis of a family of four coordinated 14-electron rhodium complexes. The newly synthesized complexes were characterized in solution by multinuclear NMR spectroscopy and in the solid-state by single-crystal X-ray diffraction. These d⁶ complexes possess sawhorse …

Critical (Re)Approach To Higher Education Admission Policy: The Impact Of Open Enrollment Policy Implementation, Shirdonna Yvonne Lawrence

Theses and Dissertations

Federal and state policies affecting higher education, like the Morrill Land Grant Act of 1832, Brown vs. Board of Education, and Higher Education Act of 1965 have posited change regarding the proliferation of diversity and expansion of access (Thelin, 2011).

I analyzed BOT policies for enrollment and conducted a socio-diagnostic CDA on the implementation of admission policy to understand the impact of the policies’ implementation. I focused on 1) exploring how open enrollment (OE) policies were constructed, 2) how institutions adopt and interpret these policies, and 3) how individuals at the institution enact these policies, by conducting a discourse-historical analysis …

Evaluation For Using Expended Bioelectrochemical Systems As Soil Amendments For Improved Corn Plant Growth And A Drought Resistant Soil., Jackson Lee Sauers

Theses and Dissertations

A long-held practice is to mix agricultural soil with a soil amendment to improve growing conditions in crops. A common soil amendment is biosolids produced from both municipal and dairy wastewater due to the macro- and micronutrients within it. Both the agricultural and wastewater industries are participating in the Circular Economy concept (CEC). Two experiments explored using expended bioelectrochemical systems (BES) that treated either synthetic dairy wastewater (DWW) or synthetic municipal wastewater (SWW) as soil amendments to improve corn plant growth when treated with three different nutrient treatments: 100%- 50%- and 0% Hoagland Nutrient Solutions. Biochar and used terracotta clay …

The Effects Of Professional Experience On Ethical Profiles Of Housing And Residence Life Staff, Sirena L. Cantrell, Sirena L. Cantrell

Theses and Dissertations

The intent of this study was to explore and understand the effects of professional experience on the ethical profiles of housing and residence life staff. Through a survey design, this study used the Managerial Ethical Profile (MEP) to analyze the professional experience of members of the Association of College and University Housing Officers – International (ACUHO-I). The MEP scale measures the range of influences on respondents and describes the major tendencies by placing respondents in ethical profiles. Results from this study indicated that professional experience does influence respondent ethical profiles. This study contributes to the field of higher education by …

Assessing The Legacy Of Erosion And Flood Control Management Efforts On The Fish Assemblages And Physical Conditions Of Yazoo Basin Bluff Hill Streams, Nicky M. Faucheux

Theses and Dissertations

The hills of Yazoo Basin have a long history of land use modification and subsequent erosion and flood control issues. In response, federal actions were taken to address these issues beginning after the Mississippi River flood of 1927. Four major flood control reservoirs were built in 1932-1957, and instream low-drop grade control structures (GCS) were installed beginning in the 1980s. The objective of my dissertation was to ascertain the long-term effects of these efforts on stream fish assemblages and channel morphology. To assess whether the reservoirs affected upstream fish assemblages as barriers to recolonization by fluvial fishes or as source …

The Use Of Single-Subject Research Design For Assessment, Evaluation, And Research In Higher Education, Jordan C. Spencer

Theses and Dissertations

While enrolling in a college for a degree is still considered to be more of the expectation than the rule in households across the United States it is facing public criticism regarding its overall cost versus long-term benefits. This has prompted researchers to reevaluate practices in higher education to determine ways in which post-secondary institutions can improve their overall outcomes. In part, research indicates that this should include revisions to assessment, evaluation, and research (AER) practices. Currently, higher education faces many challenges associated with rigorous AER practices, which include an institutional focus on accountability measures, organizational challenges, and difficulties in …

From The Sky To The Smartphone: Communicating Weather Information In A Digital Age, Cole M. Vaughn

Theses and Dissertations

As new technology has emerged in the digital era, the public can now choose from a variety of new media from which to get weather information. Weather applications (apps) and social media have emerged as some of the popular new media. This study sought to understand the extent to which these new media are used, how weather apps are perceived, how the news media used Twitter during Hurricane Irma, and how the public engaged with the news media’s tweets. A survey and dataset of tweets were used to evaluate the research questions and hypotheses of this research. The study found …

Oxidized Fibrin Alginate Microbeads To Treat Vascular Calcification, Brittany Nichole Macha

Theses and Dissertations

Calcification is linked to a high prevalence of cardiovascular events and mortality due to arterial stiffness. Stiffening of the arteries in the case of medial calcification is due to hydroxyapatite mineral deposited in the artery thus leading to the loss of elastin. A possibility of removing this rogue mineral along the vessel walls could be the use of osteoclasts. Osteoclasts, a type of osteocyte, have the unique ability to absorb bone in the bone turnover process. It is proposed that in the future, osteoclasts be delivered to the site of mineralization through oxidized alginate-fibrin microbeads. Alginate hydrogels have proven great …

Quasi 1d Modelling Of A Scramjet Engine Cycle Using Heiser-Pratt Approach, Asmaa Chakir

Theses and Dissertations

Scramjet engines are key for sustained hypersonic flights. Analytic models play a critical role in the preliminary design of a scramjet engine configuration. The objective of this research is to develop and validate a quasi-1D model for the scramjet engine encompassing inlet, isolator and combustor, to evaluate the impact of flight conditions and design parameters on the engine functionality. The model is developed assuming isentropic flow in the inlet with a single turn; modified Fanno-flow equations in the isolator that account for the area change of the core flow; and the combustor is modeled using Heiser-Pratt equations accounting for the …

Stable Numerical Methodology For Variational Inequalities With Application In Quantitative Finance And Computational Mechanics, Davood Damircheli

Theses and Dissertations

Coercivity is a characteristic property of the bilinear term in a weak form of a partial differential equation in both infinite space and the corresponding finite space utilized by a numerical scheme. This concept implies \textit{stability} and \textit{well-posedness} of the weak form in both the exact solution and the numerical solution. In fact, the loss of this property especially in finite dimension cases leads to instability of the numerical scheme. This phenomenon occurs in three major families of problems consisting of advection-diffusion equation with dominant advection term, elastic analysis of very thin beams, and associated plasticity and non-associated plasticity problems. …

The Effects Of Glyphosate Salts And Volatility-Reducing Agents (Vra) On Dicamba Volatility, Nicole Glenn

Theses and Dissertations

Dicamba is often tank mixed with glyphosate to increase herbicidal efficacy but may contribute to off-target movement (OTM). In recent years, volatilization has become problematic for dicamba-containing herbicides, resulting in increased regulatory requirements necessitating the use of volatility-reducing agents (VRA) for application. Research was conducted in 2021 and 2022 using low tunnels in a field environment and humidomes in a greenhouse environment to further assess how glyphosate salts and VRAs affect dicamba volatility. Our data indicate that the inclusion of glyphosate to dicamba can increase dicamba volatility, depending on the glyphosate salt used. The inclusion of the evaluated VRAs will …

Understanding The Relationship Among Cool Temperatures, Growth, Metabolism, And Energy Use Of Ictalurus Spp., Abby Vaughn

Theses and Dissertations

Although U.S. commercial catfish aquaculture ponds are in temperate regions and experience cool to cold temperatures during the winter, few studies have investigated the effects of low temperatures on catfish physiological processes. Therefore, growth, metabolism, swimming performance, and blood variables were compared between channel (Ictalurus punctatus), blue (I. furcatus), and hybrid (I. furcatus x I. punctatus) catfish at 10 and 20°C. Accelerometers were also used to evaluate relationships among acceleration, metabolism, and tail beat frequency (TBF) during swimming performance tests. Channel catfish experienced the greatest growth, yet growth was diminished across all fish types at 10°C. Metabolic processes, swimming performance, …

Microstructure And Sensory Attributes Of Rabbiteye Blueberries Subject To Osmotic Dehydration And Two Freezing Methods, Antonio Carlos Garcia

Theses and Dissertations

Frozen, thawed and osmotically-dehydrated highbush (HB) (Vaccinium corymbosum) and rabbiteye (RB) (V. virgatum) blueberries were analyzed under a scanning electron microscope (SEM) to observe microstructural differences in their skin. Rabbiteye blueberries of both frozen, thawed and osmotically-dehydrated treatments, had thicker skins than highbush blueberries. Rabbiteye blueberries, collected from local farms, packed and blast frozen (PBF), had thinner skins than individually quick-frozen (IQF) blueberries. Washing berries prior to freezing had no effect on skin thickness. Sensory analysis of samples determined there were no differences (p > 0.05) between PBF and IQF methods and species with respect to skin intactness, grittiness, sweetness, and …

Seasonal Comparison On The Effectiveness Of Control Methods For Microstegium Vimineum In The North Carolina Piedmont, Casey Beam

Theses and Dissertations

Microstegium vimineum, or Japanese stilt grass, is an invasive species that readily outcompetes native vegetation and is of poor forage quality for wildlife. This species is widespread throughout the southeastern United States, including North Carolina. Much of this region is privately owned and there is a gap in the literature providing succinct information about the best methods of treatment, timing of treatment, and effects of treatment on native herbaceous plants in this region. In two parts, this study seeks to address this gap by employing treatments that are easily accessible to landowners at different times during the growing season and …

Assessing Wood Failure In Plywood By Deep Learning/Semantic Segmentation, Ramon Ferreira Oliveira

Theses and Dissertations

The current method for estimating wood failure is highly subjective. Various techniques have been proposed to improve the current protocol, but none have succeeded. This research aims to use deep learning/semantic segmentation using SegNet architecture to estimate wood failure in four types of three-ply plywood from mechanical shear strength specimens. We trained and tested our approach on custom and commercial plywood with bio-based and phenol-formaldehyde adhesives. Shear specimens were prepared and tested. Photographs of 255 shear bonded areas were taken. Forty photographs were used to solicit visual estimates from five human evaluators, and the remaining photographs were used to train …

Comparing Importance Of Knowledge And Professional Skill Areas For Engineering Programming Utilizing A Two Group Delphi Survey, John F. Hutton

Theses and Dissertations

All engineering careers require some level of programming proficiency. However, beginning programming classes are challenging for many students. Difficulties have been well-documented and contribute to high drop-out rates which prevent students from pursuing engineering. While many approaches have been tried to improve the performance of students and reduce the dropout rate, continued work is needed. This research seeks to re-examine what items are critical for programming education and how those might inform what is taught in introductory programming classes (CS1). Following trends coming from accreditation and academic boards on the importance of professional skills, we desire to rank knowledge and …