Digital Commons Network^™

The Perception And Use Of Native Plants In The Landscape: Understanding The Practices Of Landscape Architects In The Southeast United States, Megan Wichlan

Theses and Dissertations

Landscape architects and designers have the ability to construct plantings in a landscape with native or non-native plants, or a combination of both plant types. The question at hand is, why choose one over the other? This study explores what might impact the plant choice decisions of practicing landscape architects in the southeast United States. A survey is utilized to understand how respondents make plant choice decisions and perceive native plants. Comparisons between previous studies are made focusing on their distribution methods, survey populations and major findings. The findings of this study are not conclusive due to a small response …

Novel 3d Bench Top Model For Vascular Calcification Research, Ursla-Marie K. Offiah

Theses and Dissertations

Cardiovascular disease is the leading cause of non-communicable disease in the whole world killing 17 million people in 2012. Among the many vascular diseases is vascular calcification (VC) which is the mineral build up in the walls of blood vessels. Medial calcification is the plaque buildup in the medial layer of the blood vesicle that is characterized by arterial stiffness and high blood pressure. Current calcification research involves two dimensional (2D) lab methods such as flat petri dishes to investigate the mechanism that causes and inhibits vascular calcification. Research has shown that the use of three-dimensional (3D) models can be …

Rock-Fluid Interaction And The Incorporation Of Cations Into Calcite During Recrystallization In Multiple Hydrothermal Systems., Van Anh Nguyen

Theses and Dissertations

Fluid-rock interaction causes an exchange of isotopes or elements through various reactions. The rate of these reactions strongly depends on temperature. The interaction involves dissolution precipitation, chemical exchange reactions, redox reactions, diffusion, and their combinations. The goal of studying fluid-rock interaction is to understand the change in mineral chemistry of the rock materials when in contact with an aqueous solution. These processes occur in all regions of the Earth where aqueous solutions are found. This work is comprised of three independent studies which provide an understanding about crystallization processes under multiple hydrothermal conditions with geological and environmental applications.

In the …

Defining Viable Solar Resource Locations In The Southeast United States Using The Satellite-Based Glass Product, Jolie Kavanagh

Theses and Dissertations

This research uses satellite data and the moment statistics to determine if solar farms can be placed in the Southeast US. From 2001-2019, the data are analyzed in reference to the Southwest US, where solar farms are located. The clean energy need is becoming more common; therefore, more locations than arid environments must be observed. The Southeast US is the main location of interest due to the warm, moist environment throughout the year. This research uses the Global Land Surface Satellite (GLASS) photosynthetically active radiation product (PAR) to determine viable locations for solar panels. A probability density function (PDF) along …

An Investigation Into The Velocity-Dependence Of The Coefficient Of Friction Between Concrete And Maraging Steel, Trace A. Duncan

Theses and Dissertations

This work investigates the velocity-dependent coefficient of friction between concrete and 300 Maraging steel over short displacements. A modified torsional Hopkinson bar is utilized for rotating thin-walled steel rings in contact with a concrete disk under static precompression. Rotational velocity is varied between tests to determine the velocity dependence of the friction coefficient. Normal force is varied between certain tests to determine the pressure dependence of the friction coefficient between the concrete and steel. Three different types of concrete are tested to deduce any composition effect on the friction coefficient. Dry and greased conditions’ impact on the friction coefficient are …

Estimating Hand-Grip Forces Causing Cumulative Trauma Disorder, Purva P. Talegaonkar

Theses and Dissertations

Wearable sensors have garnered considerable interest because of their potential for various applications. However, much less has been studied about the Stretchsense pressure sensor characteristics and its workability for industrial application to prevent potential risk situations such as accidents and injuries. The proposed study helps investigate Stretchsense pressure sensors' applicability for measuring hand-handle interface forces under static and dynamic conditions. The BendLabs sensors - a multi-axis, soft, flexible sensing system was attached to the wrist to evaluate the wrist angle deviations. In addition, the StretchSense stretch sensors were attached to the elbow joint to help estimate the elbow flexion/extension. The …

Evaluating Non-Invasive Environmental Methods For Detecting Tropical African Pangolin Species To Inform Conservation Actions, Ichu Godwill Ichu

Theses and Dissertations

Tropical African pangolin species are threatened throughout their range due to habitat loss and illegal take. Limited knowledge on distribution has rendered conservation efforts challenging. Methods commonly used for other wildlife species need to be tested for each pangolin species as each has variable ecologies requiring specific detection and monitoring techniques. This thesis evaluates the efficacy of two non-invasive environmental methods for detecting tropical African pangolin species, and consists of two complementary studies; a proof of concept study using soil sourced eDNA from a white-bellied pangolin enclosure in the Columbus Zoo, Ohio, to detect the species, and a field study …

(Re)Constructing Homescapes: “Archaeological Remote Sensing” And Ground-Truthing Of The Walker Place Homestead At Spirit Hill Farm, Tate County, Mississippi, Gabriel Griffin

Theses and Dissertations

This thesis focuses on an early nineteenth-century homestead known as the Walker Place homestead at Spirit Hill Farm in northern Mississippi. The goal of this thesis is to conduct a ground-penetrating radar (GPR) and shovel test survey to explore how changing landscapes simultaneously (re)create and destroy senses of place or Homescapes. Homescapes have received little attention in the field of archaeology and have not been applied to Euro-American Homescapes. I apply this theoretical construct in a novel way as a venture to further develop an avenue in archaeology to be collaborative and understand the past in a way that accurately …

Quantifying Numerical Weather And Surface Model Sensitivity To Land Use And Land Cover Changes, Hossein Lotfi

Theses and Dissertations

Land surfaces have changed as a result of human and natural processes, such as
deforestation, urbanization, desertification and natural disasters like wildfires. Land use and land
cover change impacts local and regional climates through various bio geophysical processes across
many time scales. More realistic representation of land surface parameters within the land surface
models are essential to for climate models to accurately simulate the effects of past, current and
future land surface processes. In this study, we evaluated the sensitivity and accuracy of the
Weather Research and Forecasting (WRF) model though the default MODIS land cover data and
annually updated …

Ex Vivo Biomechanical Comparison Of A Novel Compression Screw Fastener And Traditional Ao Cortical Bone Screw For Fixation Of A Simulated Slab Fracture In The Equine Third Carpal Bone, Allison Salinger

Theses and Dissertations

Frontal plane slab fractures account for the majority of third carpal bone (C3) fractures in performance horses. Treatment is stabilization with an AO cortical screw. Complications are fragment splitting, fragment spinning, and irritation of dorsal soft tissue structures. A novel, headless, cannulated screw with interlocking threads (the Headless Compression Screw Fastener, HCSF) has been developed to resist multidirectional forces. Simulated C3 slab fractures were created in nine paired equine carpi. HCSF or AO cortical screws were loaded in shear to failure. Stiffness, maximum load to failure, and yield load was assessed in linear mixed models. No significant difference was detected …

Methods And Tools To Improve Performance Of Plant Genome Analysis, Drew Ferrell

Theses and Dissertations

Multi -omics data analysis and integration facilitates hypothesis building toward an understanding of genes and pathway responses driven by environments. Methods designed to estimate and analyze gene expression, with regard to treatments or conditions, can be leveraged to understand gene-level responses in the cell. However, genes often interact and signal within larger structures such as pathways and networks. Complex studies guided toward describing dynamic genetic pathways and networks require algorithms or methods designed for inference based on gene interactions and related topologies. Classes of algorithms and methods may be integrated into generalized workflows for comparative genomics studies, as multi -omics …

Experimental Study On Co2-Sensitive Polyacrylamide As Potential In-Situ Sealing Agent For Co2 Leakage Pathways In Geological Storage Sites, Iris Laihmen Quan Lopez

Theses and Dissertations

As the world pushes for ‘greener’ technologies and carbon neutrality, efforts have focused on creating novel ways to mitigate humankind’s carbon footprint. Carbon capture and storage (CCS) has become a prevalent technique that has proven to be an effective long-term method to safely relocate excess carbon dioxide (CO₂) into subsurface formations. However, CCS is a newer technique which requires constant monitoring due to potential leakage pathways present in CO₂ storage sites; therefore, a preventive approach to seal leakage pathways is recommended. This dissertation explores the potential of CO₂-sensitive polyacrylamide (CO₂-SPAM) as a novel …

Effect Of Cover Crops, Grazing And Tillage Practices On Soil Microbial Community Composition, Function, And Soil Health In East Central Mississippi Soybean Production System., Namita Sinha

Theses and Dissertations

Integrating crop and livestock is being considered to improve soil health by carbon sequestration. A two-year study (2019-2021) at CPBES in Newton, MS was aimed to evaluate soil microbial diversity in the warm, humid regions, specifically southeastern USA. Amplicons targeting bacterial 16S rRNA genes and fungal ITS2 regions were sequenced. Taxonomic assignment and microbial diversity characterization were performed using QIIME2^®. Soil fungal diversity showed significant differences (alpha diversity, p = 0.031 in yr. 2020 and beta diversity, p = 0.037 in yr. 2021). Canonical Correspondence Analysis (CCA) and Mantel test showed significant influence on fungal diversity due to …

The Impacts Of The Covid-19 Pandemic On The Food Security Of Mississippians, Hannah Noel Irwin

Theses and Dissertations

Mississippi leads the United States in food insecurity, with 15.3% of Mississippians experiencing food insecurity in a given year. To determine the impacts of the COVID-19 pandemic on the food insecurity of Mississippians, a survey containing the USDA Household Food Security Questionnaire was distributed to adult Mississippi residents. By employing the USDA Household Food Security Scale and the Foster-Greer-Thorbecke Methodology, this study finds that the food insecurity rate, food insecurity gap, and squared food insecurity gap have worsened in Mississippi since the beginning of the COVID-19 pandemic. Additionally, this study finds that households which were food insecure prior to March …

The Effect Of Maternal Melatonin Supplementation During Mid To Late Gestation On Offspring Muscle Growth And Development In Swine, Thomas Warren Dobbins

Theses and Dissertations

Melatonin is a neuroendocrine hormone most often associated with circadian rhythms, but also has antioxidant and vasodilative properties. Through these properties, exogenous melatonin supplementation has been shown to increase both fetal and postnatal parameters in livestock species, however no research has been performed in swine. This project was split into a prenatal and postnatal study, wherein sows were supplemented from approximately gestational day 38 to 100 before undergoing a terminal hysterectomy for the prenatal portion, and from gestational day 60 to farrowing. Melatonin increased fetal morphometrics in a seasonal dependent manner, where fetuses from melatonin supplemented sows had increased measurements …

Development Of The Subwave Rov And Neural-Inertial Positioning System, Jason Farmer

Theses and Dissertations

This report documents the development of the Subwave, a remotely-operated underwater vehicle (ROV), and an artificial neural network based inertial positioning system. The Subwave uses the open-source ArduSub software framework, commercial-off-the-shelf hardware components, and several custom systems. It is designed as a platform for researching autonomous underwater vehicles (AUVs). The first step for an AUV is navigating waypoints, which requires the AUV to know its global position. Since global navigation satellite systems (GNSSs) are denied underwater, the available underwater positioning systems were surveyed and determined that all the available systems were too large and expensive for the Subwave. It was …

Assessing Virtual Free-Choice Agricultural Learning: A Mixed Methods Approach, Richard John Kennedy

Theses and Dissertations

Since the mid-19th century, agricultural museums and living history sites, first in Scandinavia and then in the United States and Canada, have provided historical, cultural, and, sometimes, scientific information about farming to visitors. Many of these visitors have been school children on field trips. Assessment of this learning, however, has been scant, particularly within the free-choice style inherent in these types of educational venues. At the same time, assessment of free-choice learning, often analyzed through the Contextual Model of Learning (Falk & Dierking 2000), has taken place at educational sites like zoos, natural history museums, and science centers. This study, …

Assessing Non-Uniform Inbred And Hybrid Rice (Oryza Sativa) Population For Replant Decisions, Thomas William Eubank Iv

Theses and Dissertations

Optimal plant populations are critical in achieving high rice yields. The purpose of this research was to investigate yield penalties associated with inadequate, non-uniform plant populations for modern rice cultivars. Research was conducted at the Delta Research and Extension Center in Stoneville, MS, in 2019, 2020 and 2021. In one study, inbred, herbicide-resistant ‘CL153’ was drill-seeded at 73-18 kg ha^-1 after being mixed with inbred, herbicide-susceptible ‘Rex’ at 0-55 kg ha^-1. Likewise, hybrid, herbicide-resistant cultivar ‘CL XL7521’ was seeded at 29-8 kg ha^-1 mixed with hybrid, herbicide-susceptible ‘XP753’ at 0-21 kg ha^-1. At the …

Incorporating Follicle Stimulating Hormone To Stimulate Multiple Corpora Lutea For Embryo Transfer In Beef Cattle, Bryan Carter

Theses and Dissertations

Assisted reproductive technologies, such as estrus synchronization and embryo transfer, can aid producers in improving genetics by increasing the number of progeny produced from elite females. The success of embryo transfer is dependent on a viable, competent embryo and a recipient with a receptive uterine environment. Follicular development and luteinization are pertinent for the recipient to establish a functional corpus luteum (CL) that can produce adequate concentrations of progesterone (P4) and provide a uterine environment conducive for the establishment of pregnancy. The objective of this study was to determine if exogenous follicle stimulating hormone (FSH), would increase the number of …

The Employability Of State Ffa Degree Recipients In Alabama, Kailee D. Johnson

Theses and Dissertations

Many high schools have shifted from comprehensive graduation exams to a focus on College and Career Readiness. A common method used to determine when a student is college and career ready is a Career Readiness Indicator (CRI). Many CRIs demonstrate a benchmark learning goal for students. Among academic-based CRIs are Career and Technical Education (CTE) industry credentials. Credentials are just one way that agriculture classrooms contribute to student success. This study compiled existing research on CRIs and employability skills in CTE students to determine how the State FFA Degree could potentially fit into this category as well as highlight specific …

Novel Applications In Mississippi Cotton And Peanut, Anna Beth Gaudin

Theses and Dissertations

Studies were conducted in the field from 2020-2021 in peanut and cotton to optimize peanut growth and yield through prohexadione calcium application methods as well as weed control through increasing herbicide sites of action. These studies were established on multiple on-farm and small-plot locations in Mississippi. Prohexadione calcium studies concluded that following application of prohexadione calcium effects on yield and peanut growth were inconsistent. Neither varying application timing nor rate resulted in peanut yield that was different than when adhering to the label recommendations. Increasing sites of action studies concluded that broadleaf signalgrass and Amaranthus species control was optimized at …

Three Essays On Insider Trading, Haoyang Xiong

Theses and Dissertations

In the first essay we study whether and how personal off-the-job managerial indiscretions impact corporate insiders’ trading behavior. We find that executives accused of personal indiscretions earn significantly higher abnormal returns from their insider purchases and sales in a 15-day window around each trade. The results are robust to matched sample analyses. Further, insiders’ historical trading pattern or corporate culture has less explanatory power than personal attributes. We also document that exposure of these indiscretions to the public provides a disciplinary effect, as insider trading profits significantly drop following the announcement of an indiscretion, despite this drop being temporary. Corporate …

Phenotypic Evaluation Of Energycane (Saccharum Spp.) Genotypes In Northcentral Mississippi, Wyatt Armistead Eason

Theses and Dissertations

As fossil fuel supplies decrease and concerns of climate change increase, the search for alternative sources of fuel has pushed biomass crops to the forefront of discussion. Saccharum spontaneum readily hybridizes with commercial sugarcane and lends cold tolerance and greater yields to the hybrid progeny, called energycane. Twenty genotypes were tested against an energycane variety (Ho 02-113) as a control. Two locations were tested: the HH Leveck Animal Research Center (planted in 2019), and the Bearden Dairy Research Center (planted in 2020). The Bearden Dairy Research Center yielded significantly higher than the HH Leveck Animal Research Center regarding dry matter …

Classification Models For 2,4-D Formulations In Damaged Enlist Crops Through The Application Of Ftir Spectroscopy And Machine Learning Algorithms, Benjamin Blackburn

Theses and Dissertations

With new 2,4-Dichlorophenoxyacetic acid (2,4-D) tolerant crops, increases in off-target movement events are expected. New formulations may mitigate these events, but standard lab techniques are ineffective in identifying these 2,4-D formulations. Using Fourier-transform infrared spectroscopy and machine learning algorithms, research was conducted to classify 2,4-D formulations in treated herbicide-tolerant soybeans and cotton and observe the influence of leaf treatment status and collection timing on classification accuracy. Pooled Classification models using k-nearest neighbor classified 2,4-D formulations with over 65% accuracy in cotton and soybean. Tissue collected 14 DAT and 21 DAT for cotton and soybean respectively produced higher accuracies than the …

Three-Axis Magnetometer Calibration With Norm Preservation, Seth Lichlyter

Theses and Dissertations

This thesis proposes a set of methods for the purpose of improving the calibration of three-axis magnetometers. Specifically, these methods aim to improve the accuracy of the bias estimation methods currently in use. The first proposed method utilizes a constrained optimization problem based on norm preserving. The second proposed method finds the same bias estimate as the first method, but in a computationally more efficient manner. The last proposed method tackles the case where the value of the local geomagnetic field is only imprecisely known. Computer simulations demonstrate the viability of the proposed methods.

Essays On Insider Trading, Innovation, And Political Economy, Jiawei Chen

Theses and Dissertations

I study how insider trading interacts with the political economy, regulators, and other corporate governance mechanisms. In the first section, I examine the impact of insider trading restriction enforcement on firm innovation. U. S. Securities and Exchange Commission enforcement actions are intended to protect investors and limit expropriation by firm insiders, but enforcement could impact insiders’ incentives to contribute to value enhancing activities. Therefore, I explore how corporate innovation and performance respond to insider trading restrictions imposed by firms and regulators. Using manually collected data on SEC indictments against corporate insiders, I document more innovative activity following external insider trading …

Advancement Of Field-Deployable, Computer-Vision Wood Identification Technology, Adam Carter Wade

Theses and Dissertations

Globally, illegal logging poses a significant threat. This results in environmental damage as well as lost profits for legitimate wood product producers and taxes for governments. A global value of $30 to $100 billion is estimated to be associated with illegal logging and processing. Field identification of wood species is fundamental to combating species fraud and misrepresentation in global wood trade. Using computer vision wood identification (CVWID) systems, wood can be identified without the need for time-consuming and costly offsite visual inspections by trained wood anatomists. While CVWID research has received significant attention, most studies have not considered the generalization …

The Effects Of Moderate And High Temperatures On Growth, Metabolism, And Blood-Oxygen Affinity In Ictalurus Spp., Brandon Gerhart

Theses and Dissertations

Despite the growing use of hybrid catfish (Ictalurus furcatus × I. punctatus) in aquaculture, few studies have investigated the comparative effects of temperature on physiological performance with other cultured catfish. Therefore, growth, metabolism, and blood-oxygen affinity of blue (I. furcatus), channel (I. punctatus), and hybrid catfish were compared at moderate (23°C) and high (33°C) water temperatures. Channel catfish had the greatest growth and were in better condition compared to blue and hybrid catfish. Hybrid catfish standard metabolic rates did not differ from blue or channel catfish, while hybrid catfish had higher maximum metabolic rates, …

Nondestructive Assessment Of Flexural And Tensile Properties For Southern Pine Structural Lumber, Marly Gabriela Carmona Uzcategui

Theses and Dissertations

The flexural and tensile properties of visually graded southern yellow pine lumber were modeled. Longitudinal and transverse vibration techniques and proof-loading bending tests were used to assess the flexural and tensile properties of southern pine lumber. The properties evaluated were dynamic modulus of elasticity (dMOE), static modulus of elasticity (E_b), tension modulus of elasticity (E_t), and ultimate tensile stress (UTS). The tensile properties were evaluated in the direction parallel to the grain. This study presents the results of tests conducted on No. 2 2 × 6 and 2 × 10 southern pine lumber of two different …

Essays On International Banking Regulation, Wenqing Gao

Theses and Dissertations

The first chapter analyzes the impact of macroprudential policies on bank systemic risk worldwide. Using data from 63 countries over 2001-2017, I find strong evidence that macroprudential policies are effective in reducing systemic risk at the country level. The effectiveness of macroprudential policies differs across countries in the sample. Macroprudential policies are more effective in reducing systemic risk in countries with more advanced economic development, with a higher degree of concentration in the banking sector, and with less stringent micro-prudential regulations. Bank-level evidence suggests that bank size matters. The impact of macroprudential policies on constraining bank systemic risk is more …