Digital Commons Network^™

Adaptive Molecular Evolution And Biodiversity In Malaria Parasites, Haley Nicole Bodden

Theses and Dissertations

Haemosporidian parasites are the agents of malaria. Countless vertebrates are affected by haemosporidians each year. Haemosporidians have been shown to be evolving at rapid rates; leading to new species of haemosporidians being discovered and new host associations being made. Adaptive molecular evolution was detected in an important hemoglobin degradation gene, falcilysin. At multiple sites across multiple genes involved in important functions signatures of negative selection were detected. The signatures of selection across non-hemoglobin degradation genes were indicative of evolutionary conservation when compared to the more variable hemoglobin degradation genes. This is probably due to the important role the hemoglobin degradation …

Analytical Models Of Neutron Spectral Fluence, Kerma And Absorbed-Dose For Proton Therapy, Suman Shrestha

LSU Master's Theses

Abstract

Purpose: The accurate prediction of stray neutron dose has become increasingly important as it increases the risk of second cancer development after proton therapy. Previously reported analytical models predicted the quantity dose equivalent, which includes physical and biological considerations but does not explicitly take into account material dependence and variation in the radiation quality. The purpose of this study was to investigate the feasibility of an analytical model of absorbed dose to water from stray neutrons in proton therapy.

Methods: To calculate neutron absorbed dose and kerma in water, the authors developed analytical models of neutron spectral fluence and …

Evaluation Of Impacts Of Conservation Practices On Surface Water And Groundwater At Watershed Scale, Xiaojing Ni

Theses and Dissertations

For an agricultural watershed, best management practice (BMP) is a conservational way to prevent non-point source pollution, soil and water loss and mitigate groundwater declination. In this dissertation, several BMPs of tail water recovery system, conservation tillage system and crop rotation were selected and evaluated in order to demonstrate the impacts of those activities on stream water quality and quantity. Besides, a land use change scenario was also evaluated. In order to evaluate the scenarios comprehensively, Soil and Water Assessment Tool (SWAT) and Annualized Agricultural Non-point Source Pollution (AnnAGNPS) were applied to simulate surface hydrology scenarios, and Modular flow (MODFLOW) …

Modeling Phase And Sorption Equilibria Using First Principles Simulations, Himanshu Goel

Theses and Dissertations

To capture the underlying chemistry and physics of a system on electronic structure platform, it is necessary to accurately describe the intermolecular interactions such as repulsion, polarization, hydrogen bonding, and van der Waals interactions. Among these interactions, van der Waals (dispersion) interactions are weak in nature as compare to covalent bonds and hydrogen bonding, but it is physically and chemically very important in accurately predicting condensed phase properties such as Vapor liquid equilibria. This presents a significant challenge in modeling VLE using a first principles approach. However, recent developments in dispersion corrected (DFT-D3) and nonlocal density functionals can model dispersion …

The Evaluation Of Two Different Harvesting 'Topbunch' And 'Hi-Crop' Collards (Brassica Oleracea (L)) Leaves From Plants Grown In A Wiregrass Tunnel House, Edward Sparks, Raymon Shange, Jacquelyn Jackson, Victor Khan, James E. Currington, Ramble Ankumah, Nathaniel Ellison, George X. Hunter Jr., Jeffery L. Moore

Professional Agricultural Workers Journal

A study was conducted to determine if a 100% or 50% harvest intensity of ‘Topbunch’ collards leaves could be a recommended practice for Tunnel House producers. The experiment was conducted as a split-plot design with harvest dates as main plots, and harvesting intensity of 100% or 50% of leaves as sub-plots. All treatments were replicated three times, drip irrigated, and fertilized according to soil test recommendations. The results showed significant interactions between harvest methods and dates for number and weight of leaves harvested. There were also significant differences for the weight of leaves harvested and numbers. The leaf recovery rates …

A Framework For Improving Breast Cancer Care Decisions By Using Self-Organizing Maps To Profile Patients And Quantify Their Attributes, Vanda Victoria Spencer

Theses and Dissertations

Considering the commonality of breast cancer among women in the United States and the increasing popularity of precision medicine and data analytics in healthcare, the aim of this study was to use self-organizing maps (SOM) to profile and make decisions about breast cancer patients. Breast cancer mass measurements were combined with nine non-medical attributes—family income, history of cancer, level of education, preference of probability level, presence of dependents, employment status, marital status, age, and location—that were randomly generated based on recent population statistics and fed into a SOM. The SOM’s accuracy was evaluated at around 80%. To show the decision-making …

A Geotechnical Perspective On Carbon Sequestration In Clay Using Gasifier Biochar, James Michael Williams

Theses and Dissertations

There is a growing need for employing sustainable soil improvement techniques. Concurrently, soil carbon sequestration methods continue to receive more attention in an attempt to reduce greenhouse gas levels contributing to climate change. Exploring the use of gasifier biochar for soil improvement can possibility address these two needs simultaneously. This study investigates the effect of gasifier biochar amendment on mechanical, chemical and hydraulic properties of a local clay with poor engineering properties. Specifically, strength, swelling, compressibility, collapsibility, permeability, water retention, cation exchange capacity, pH, and microstructural characteristics were determined for the clay amended with 5, 10, and 20% biochar. Two …

A Network-Based Method For The Analysis Of Use And Function In Stone Tool Kits: Implications For Late Prehistoric Settlement Patterning In Northeast Mississippi, Jason Nathaniel Ervin

Theses and Dissertations

A network-based method is developed for analyzing use in stone tool assemblages, where 'use' denotes the tasks for which chipped edges are suitable. Modeling chipped edges as nodes, use-wear and retouch as edge traversals, use-life trajectories of chipped edges as inter-connecting paths, and `tools' as subnetworks over which design tolerances are maintained on edge morphology, the method is an attempt to improve on existing models, allowing for complex, continuous change and multiple uses throughout a chipped edge's use-life. Avoiding analogy-based categories, the method is designed to highlight rather than obscure the possibilities for use and multi-use. Potential for integration into …

An Experimental Investigation Of Causal Explanations For Depression And Willingness To Accept Treatment, Taban Salem

Theses and Dissertations

The present study was aimed at experimentally investigating effects of causal explanations for depression on treatment-seeking behavior and beliefs. Participants at a large Southern university (N = 139; 78% female; average age 19.77) received bogus screening results indicating high depression risk, then viewed an explanation of depression etiology (fixed biological vs. malleable) before receiving a treatment referral (antidepressant vs. psychotherapy). Participants accepted the cover story at face value, but some expressed doubts about the screening task’s ability to properly assess their individual depression. Within the skeptics, those given a fixed biological explanation for depression were relatively unwilling to accept either …

The Cut And The Color Line: An Environmental History Of Jim Crow In The Deep South's Forests, Owen James Hyman

Theses and Dissertations

This dissertation argues the South’s system of Jim Crow segregation, exploitation, disfranchisement, and violence was both embedded in and evolved through the successive reorganizations of the region’s forests. In turn, it tells a three-hundred-year history of black resistance and resilience in the forests of the Deep South. In the longleaf pine and bottomland hardwood forests along the Gulf of Mexico, water proved just as important as soil in determining the contours of the colonial and antebellum plantation regimes. This project follows the water to show how African Americans drew on deep environmental knowledge to form maroon communities in the colonial …

Assessing Irrigation Scheduling Using Mississippi Irrigation Scheduling Tool (Mist) And Soil Moisture Sensors, Hazel Buka

Theses and Dissertations

By using the Soil Conservation Service (SCS) “polynomial” method for corn in the Mississippi Irrigation Scheduling Tool (MIST), the total number of irrigations required during the growing season can be reduced depending on the variety, growing degree days required to reach maturity, and the length of the growing season. Results showed that even though the SCS method called for irrigations earlier in the season, the method did not trigger irrigation events after the crop reached physiological maturity. In addition, although changing the timing of model initiation (planting vs emergence) was not important on the total crop water use, it may …

Behavior Plasticity Mitigates The Effect Of Climate Warming In White-Tailed Deer, Carter L. Wolff

Theses and Dissertations

Climate change can alter the ecology of natural systems through various mechanisms, such as direct thermal effects on a consumer. However, consumers may employ behavioral mechanisms in response to warming. Among these may be spatial or temporal shifts in activity, making use of thermal heterogeneity on the landscape. Despite this, few studies consider the role of behavioral plasticity and spatial or temporal heterogeneity in the context of climate change. I conducted experiments to evaluate the importance of behavior in mediating the net effects of warming at the population and the individual level using captive white-tailed deer (Odocoileus virginianus). I created …

Determination Of Age-Related Differences In Activation And Detoxication Of Organophosphates In Rat And Human Tissues, Edward Caldwell Meek

Theses and Dissertations

The mechanism of toxic action for organophosphates (OPs), originally developed as insecticides, is the persistent inhibition of acetylcholinesterase (AChE) resulting in accumulation of acetylcholine and subsequent hyperstimulation of the nervous system. Many OPs require bioactivation via cytochromes P450 to oxon metabolites which are anticholinesterases. Organophosphates display a wide range of acute toxicities. Differences in the OPs’ chemistries results in differences in the compounds' metabolism and toxicity. Acute toxicities of OPs appear to be principally dependent on compound specific efficiencies of detoxication, and less dependent upon efficiencies of bioactivation and sensitivity of AChE. Esterases, such as carboxylesterase (CaE) and butyrylcholinesterase (BChE), …

Development And Visualization Of Bioluminescent Virulent Aeromonas Hydrophila In Live Catfish, Eda Ozdemir

Theses and Dissertations

Virulent Aeromonas hydrophila (vAh) is an important emerging bacterial pathogen causing motile Aeromonas septicemia (MAS) in farmed catfish. Understanding the pathogenicity of the disease is essential for the development of preventive measures. In this study, we aimed to develop a bioluminescent virulent A. hydrophila (BvAh) strain to understand the pathogen-host interactions during infection. To achieve this, a new bioluminescence expression plasmid, pAKgfplux3, was constructed and mobilized to vAh. Catfish were challenged with BvAh using immersion, injection, and adipose fin clip procedures, and bioluminescence signal was tracked in live catfish during infection. We developed a novel BvAh strain for the first …

Effect Of Maternal Melatonin Levels During Late Gestation On The Programming And Metabolic Disposition Of Adipose Tissue And Skeletal Muscle In Bovine Offspring, Robyn Carl Thompson

Theses and Dissertations

The objectives of this study were to determine: the effects of maternal melatonin (MEL) supplementation during late gestation on the histological and molecular regulation in the Longissimus dorsi (LM) muscle of fetal bovine offspring, composition and gene expression of fetal perirenal (PR) adipose tissue, and LM gene expression in postnatal offspring at birth and d 195 of age. Maternal supplementation of MEL during late gestation resulted in no difference in calf fetal body weight or birth weight. However, at d 195 of age, calves from MEL treated dams had an average body weight increase of 20 kg. Fetal LM weight …

Effects Of Cultural Practices On Soybean Nectar Production, Tyler Miles Smith

Theses and Dissertations

Experiments were conducted to determine the effects of cultural practices such as irrigation, planting date, and maturity group on soybean nectar production. Multiple interactions between different factors influences the amount of total sugar present in soybean flowers. Pod production was increased in later planted soybean, but later planting resulted in reduction in yield. Another study was conducted to explore the effects that variety selection had on soybean nectar production. Soybean nectar production was highly variable among varieties and was influenced further depending on their growing location. Later maturing varieties produced significantly more soybean pods. This increase in pod production was …

Exploration Of Experiential Stem Education Programs In Mississippi And Their Use By Mississippi K-12 Educators, Randi Robison

Theses and Dissertations

Science, technology, engineering, and mathematics (STEM) are important fields in today’s world. Educators can incorporate informal STEM learning opportunities into their curriculum by taking students on field trips. In this research, 210 Mississippi STEM education centers were identified, and 50 completed a survey about their programs. 17 Mississippi STEM clubs were identified and 14 completed surveys. 81 Mississippi STEM K-12 educators also completed surveys about field trips and STEM programs offered near them. A Google Map, a Geodatabase, shapefiles, and Google Spreadsheets were created to manage these data. Maps were created displaying locations of STEM centers, responses from STEM centers …

Comparative Genome Analysis Of Fish Pathogens In The Flavobacterium Genus, Salih Kumru

Theses and Dissertations

Aquaculture has potential to support the food supply of increasing world population. Flavobacterial diseases pose a serious problem in wild and aquacultured fish stocks throughout the world. Flavobacterium columnare, F. branchiophilum, and F. psychrophilum are well-known Flavobacterium species that cause important fish losses. Recently, new Flavobacterium species, isolated from diseased fish, have been reported, but their virulence mechanisms are not clear. Thus, the goal of this study was to understand pathogenicity of Flavobacterium species. To this goal, 86 Flavobacterium genomes were analyzed by comparative genomics. Predicted virulence genes were identified for all genomes. For each species, unique and shared virulence …

Composting Of Cross Laminated Timber (Clt) Sawdust, Gulbahar Bahsi-Kaya

Theses and Dissertations

A three-month study evaluated composting of cross laminated timber (CLT) sawdust amended with 10% and 20% chicken litter. Moisture was provided by rainwater or deionized water depending on the precipitation. The contents in the containers were mixed once or twice a week for aeration. Samples were collected at 0, 45, and 90-day intervals to measure weight loss, moisture content, pH, compost maturity, microbial count, and carbon-to-nitrogen ratio. Results indicated that composted CLT with 20% chicken litter had much higher weight reduction than others at day 45 and 90. Treatments with 10% and 20% chicken litter had a higher initial pH …

Cpvib-1, A Gaga Regulator Of Tor Signaling Pathways In The Chestnut Blight Pathogen Cryphonectria Parasitica, Di Ren

Theses and Dissertations

Cryphonectria parasitica is the causal agent of chestnut blight, which devastated the American Chestnut tree population in the early 20th century. The discovery of hypoviruses that reduce the severity of the chestnut blight infection offers the potential for biological control. However, the spread of the hypoviruses is hampered by a diverse genetically controlled nonself-recognition system, vegetative incompatibility (vic). CPVIB-1 was identified as a transcription regulator playing an important role in the programmed cell death response to this stimulus. In this study, we have found that CPVIB-1 is ubiquitin-decorated which might lead to its degradation in the proteasome pathway. RNA-Seq and …

Data Mining The Effects Of Storage Conditions, Testing Conditions, And Specimen Properties On Brain Biomechanics, Folly Martha Dzan Crawford

Theses and Dissertations

Traumatic brain injury is highly prevalent in the United States yet there is little understanding of how the brain responds during injurious loading. A confounding problem is that because testing conditions vary between assessment methods, brain biomechanics cannot be fully understood. Data mining techniques were applied to discover how changes in testing conditions affect the mechanical response of the brain. Data were gathered from literature sources and self-organizing maps were used to conduct a sensitivity analysis to rank considered parameters by importance. Fuzzy C-means clustering was applied to find any data patterns. The rankings and clustering for each data set …

Comparative Analysis Of The Gut Microbiome In Wild And Lab Strains Of Anopheles Quadrimaculatus Say, And Its Effect On Innate Immunity, Eleanor Marie Moen

Theses and Dissertations

Vector competence of mosquitoes has been linked to the conditions in which the larvae mature to adults. The microbial community obtained from the rearing environment is suspected to be one key factor in this interplay. A better understanding of how the rearing environment affects the gut microbiome and Anopheles-Plasmodium interactions could be useful for understanding observed lab vs. field differences in Plasmodium biology and help drive future control efforts. Currently there is a lack of research done on the differences between lab strain mosquitoes and their rearing environments and how lab mosquitoes differ from wild type mosquitoes. Bridging this gap …

Anthropogenic Impacts On Wildlife Mortality And Vertebrate Scavenging Communities, Jacob Earl Hill

Theses and Dissertations

Roads cause substantial wildlife mortality, but there is currently limited understanding of the relative magnitude of this mortality source. There are also substantial gaps in knowledge concerning the ecological ramifications of carrion introduced to the environment from vehicle collisions and in particular how vertebrate scavengers may consume carrion resulting from vehicle collisions. Although a variety of factors influence scavenger use of carcasses, the mechanisms influencing competition for this resource between obligate and facultative scavengers have not been thoroughly explored. I conducted a global synthesis of mortality of terrestrial vertebrates documenting 42,755 mortalities of known cause from 120,657 individuals representing 305 …

Translating Global Nature: Territoriality, Environmental Discourses, And Ecocultural Identities, José R. Castro-Sotomayor

Communication ETDs

In this study, I explore environmental discourses circulating among Indigenous transboundary organizations working on environmental initiatives at the border between Ecuador and Colombia. I focus on three global environmental discourses –sustainability, development, and climate change– as they are at the core of the global environmental governance vernacular. La Gran Familia Awá Binacional (GFAB), one of the few transboundary Indigenous organizations working along the binational border, utilizes these global concepts to frame their environmental initiatives and projects. I use a critical and interpretive qualitative approach to investigate, deconstruct, and rearticulate global environmental discourses circulating among and translated by two of the …

Retinoic Acid Receptor Signaling During Paraxial Mesoderm Differentiation Of Pluripotent Stem Cells, Ryan Patrick Russell

Doctoral Dissertations

The treatment of severe musculoskeletal injuries is currently limited to surgical intervention and natural healing during recovery, which are not always sufficient to repair critical defects. Various cell-based approaches for repair augmentation have gained traction, however a reliable cell therapy approach has not been realized. Pluripotent stem cells (PSCs) retain the developmental potential to become any cell in the human body and are a valuable model for studying cell differentiation that hold tremendous promise for treating orthopedic injuries. The goal of our research has been to develop an efficient in vitro differentiation method to generate skeletal progenitor cells, the forerunners …

Pubh 6532-F – Environmental Health Fall, Asli Aslan

College of Public Health: Faculty Syllabi (2014-2021)

This course is designed for graduate students and provides students with an introduction and overview of the key areas of environmental health. Students will gain an understanding of the interaction of individuals and communities with the environment. Impact of environmental agents on human and ecosystem health will be analyzed. This course will also introduce current topics in environmental health and challenges faced under the changing climate and socio-economic needs and examine recent case studies and their outcomes related to environmental policy and management.

The Effects Of Habitat Management On Wildlife Use In A Managed Loblolly Pine Forest, Johannah Reed Mccollum

Theses and Dissertations

To improve habitat quality for wildlife, habitat managers prescribe various disturbances. Habitat management techniques alter the vegetation structure, composition, and quality, changing food and cover resources and availability. To investigate how habitat management and vegetation heterogeneity affect space use by wildlife species, I deployed 81 camera-traps and collected fine scale vegetation data across a variety of treatments (i.e., canopy reduction, prescribed fire, and herbicide application) in a managed loblolly pine forest. I created a new method for accounting for imperfect detection and error in camera count data. My method provided better inference about the effects of variables on animal use. …

Quantification Of Harmful Algal Blooms In Multiple Water Bodies Of Mississippi Using In-Situ, Analytical And Remote Sensing Techniques, Saurav Silwal

Theses and Dissertations

Globally, water bodies are increasingly affected by undesirable harmful algal blooms. This dissertation contributes to research methodology pertaining to quantification of the algal blooms in multiple water bodies of Mississippi using in situ, analytical, and remote sensing techniques. The main objectives of this study were to evaluate the potential of several techniques for phytoplankton enumeration and to develop remote sensing algorithms for several sensors and evaluate the performance of the sensors for quantifying phytoplankton in several water bodies. Analytical techniques such as “FlowCam”, an imaging flow cytometer; “HPLC”, high performance liquid chromatography with the chemical taxonomy program “ChemTax”; spectrofluorometric analyses; …

Regulation Of Rice Flowering Time And Seed Development, Xiaoxi Meng

Theses and Dissertations

Rice is one of the most important cereal crops for the world population. Flowering time and seed development of rice are directly related to plant regional and ecological adaptions, and productive yield. In this dissertation, to gain knowledge of seed development in rice, the status of post-translational modifications (PTMs) in developing rice seeds was investigated. Numerous modified lysine sites in developing rice seeds were identified utilizing antibody-based affinity enrichment approaches and nano-HPLC/MS/MS analyses of acetylated, succinylated, crotonylated and 2-hydroxyisobutyrylated peptides. Functional annotation analyses indicated that a wide variety of vital biological processes were targeted by lysine PTMs. A number of …

Reproductive Ecology Of White-Tailed Deer: Fetal Development And Mate Choice, Daniel L. Morina

Theses and Dissertations

Aspects of white-tailed deer (Odocoileus virginianus) reproductive ecology remain understudied. The accuracy of the fetal age estimation equation in current use is unknown. Knowledge is also limited for female choice of secondary sexual traits like antlers and body size. To address previous fetal estimation equations, I developed a model that included litter characteristics using 110 fetuses with known ages of 54 to 175 days. To address female choice, I manipulated antler size and paired large and small males while controlling allometrically related traits. I then allowed estrus females to choose between pairs of segregated males with either large and small …