Life Sciences Commons^™

Diversity, Function, And Phenotypic Plasticity Of Cryptophyte Phycobiliproteins, Kristiaän Merritt

Theses and Dissertations

Cryptophytes are a group of unicellular eukaryotic algae that can be found in a wide range of underwater habitats. Part of their ecological success can be attributed to their diverse array of cryptophyte phycobiliproteins (Cr-PBPs), a pigment class that captures wavelengths of light that are poorly absorbed by chlorophylls. Cryptophytes gained photosynthesis via secondary endosymbiosis in which their ancestor engulfed a red algal endosymbiont. Following endosymbiosis, they deconstructed the red algal photosynthetic machinery to form the Cr-PBP. Since then, the Cr-PBPs have diversified into at least 9 spectrally distinct forms. I investigated the diversity of Cr-PBP light absorption across 76 …

Leveraging Church Environments To Promote Rural Physical Activity And Healthy Eating, Kelsey Rothera Day

Theses and Dissertations

Rural residents experience a greater burden of chronic disease related to physical inactivity and poor diet than their urban counterparts. A promising strategy to improve these health behaviors in rural areas is to leverage existing structures that may support physical activity and healthy eating, such as churches, in public health interventions. Three studies were conducted as part of this dissertation. They were designed to: 1) examine whether the walkability and healthy food density of neighborhoods surrounding rural and urban churches are associated with race, socioeconomic status, and rural/urban status; 2) examine rural church leaders’ views on the role of faith-based …

Evaluating The Use And Performance Of Marine Protected Areas To Conserve Reef Fish Biodiversity In The Caribbean, Mathias Tjarko Cramer

Theses and Dissertations

Reef fishes are an integral part of life in the Caribbean, fulfilling essential roles in their native marine ecosystems and the many human communities that neighbor them. Perhaps most directly to humans, reef fishes and their fisheries are an essential source of dietary protein, and further support local human communities through employment opportunities. More indirectly, reef fishes fulfill numerous ecological roles that help maintain their native reef ecosystems, which, in turn, confer benefits to humans. For example, a recent analysis estimated that every square kilometer of coral reef generates an average annual income of $473,000 (USD), which would represent 23 …

Does Chronic Low Back Pain Influence Breathing Mechanics And Diaphragm Positioning? A Pilot Study, Lindsey Wensel

Theses and Dissertations

Background and objective: Chronic low back pain (CLBP) is a complex musculoskeletal condition and often the source of the pain is not clear. A correlation has been found to exist between incidences of low back pain (LBP) and those with respiratory diseases such as COPD. This could give reason to believe that the sequence of events could be reversed, and LBP could elicit changes in respiratory function. The purpose of this study is to investigate if CLBP has an influence on breathing mechanics and the positioning of the diaphragm in the trunk. Methods: Volunteers were recruited between the ages of …

Variability Among Individual Male Runners Influences Cumulative Loading More Than Foot Strike Type, Tamarie Trotter

Theses and Dissertations

Foot strike type affects running mechanics and may influence overuse injury occurrence. Measuring the interaction between cumulative load and foot strike type may provide additional information that could eventually help with understanding injury mechanisms. The purpose of this study was to determine how foot strike type affects cumulative loading in runners, and to determine if individual metrics change throughout a 5-kilometer sub-maximal run. 30 participants ran on an instrumented treadmill for 5 km at 3.15 m/s with their preferred foot strike type (14 rearfoot strike, 16 non-rearfoot strike). Stride rate, foot strike angle, loading rate, per stride and per km …

Nutrient Optimization For Vegetable Production Under Decoupled Aquaponics Using Brackish Water, Salma Walid Hany Ahmed Abdelfattah

Theses and Dissertations

As the world moves to more sustainable agriculture methods in the agribusiness industry, decoupled aquaponics is recognized as one of the newest techniques currently being utilized to achieve more local food security. As the topic is still freshly new within the industry, a finite number of publications and studies have been made that address the topic hands-on with its many variables. Subsequently, in this paper, an experiment was conducted to assess the most optimized production conditions of both lacinato kale (Brassica oleracea var.palmifolia) and Swiss chard Bright Light (Beta vulgaris ssp. Cicla var. flavescens) plants through the utilization of a …

Cytotoxic Activity Of Salvia Officinalis Extract Mediated By The Inhibition Of Jak2 In Breast Cancer, Salma Alawadi Dawood

Theses and Dissertations

Background: Breast cancer is the most common type of invasive cancer in women in their forties and fifties. Recent evidence suggests that JAK2/STAT3 signaling is constitutively active in breast cancer. Previous studies suggest that plant extracts, including Salvia Officinalis, have strong cytotoxic effects on breast cancer cells. The differential expression of miRNAs is also strongly linked to cancer development.

Aim: In the current study, we hypothesize that S. Officinalis extract suppresses JAK2 expression and has strong anticancer potential in MCF7 breast cancer cell lines.

Methods: GC-MS analysis showed the presence of flavonoids in dried leaf of …

Atomistic Assessment Of Drug-Phospholipid Interactions Consequent To Cancer Treatment: A Study Of Anthracycline Cardiotoxicity, Yara Elsayed Ahmed

Theses and Dissertations

Despite being one of the most effective chemotherapeutic agents developed to date, Anthracyclines are notorious for their cardiotoxicity. Their clinical use is frequently limited both in dosage and in prescription due to the severe cardiac damage they cause. The mechanism of anthracycline-induced cardiotoxicity is not yet fully understood. However, it is hypothesized that interactions with the myocardial membrane play an important role in imparting cardiotoxicity. In this study, we use molecular dynamics simulations and density functional theory calculations to study the anthracycline drug molecules and the interactions that they have with the myocardial membrane. We construct a myocardial membrane model …

Association Of Gut Microbiota Composition With Alzheimer’S-Like Disease In A Rat Model, Hana Heiba

Theses and Dissertations

With many countries turning ‘grey’ and facing an issue with aging populations, the risk of developing one form of neurodegenerative disease is increasing. Dementia, being the most common syndrome resulting from neurodegeneration, severely affects memory and cognitive functions. Alzheimer’s disease (AD) is the most common neurodegenerative disorder, with an estimated 615,000 new cases will be added to the existing 5.7 million by 2030 (Alkasir et al., 2017).

In the current study, we establish a sporadic AD-like rat model by injecting STZ intracerebrally. Stool samples were collected at two time points; after three weeks for the acute stage, and 3 months …

Improving Restoration Success Of Winterfat: Influences Of Hydrophobic Seed Coatings And Planting Depth On Seedling Emergence, Kyle Andrew Cook

Theses and Dissertations

In western North America, winterfat (Krascheninnikovia lanata (Pursh) A. Meeuse & Smit) is a valuable protein-rich subshrub whose restoration has been limited by poor seed flowability and low rates of seedling establishment. Seed flowability can be limited by a dense covering of hairs on winterfat fruits that can cause them to clog in mechanized equipment. Seedling establishment can be limited by premature germination of fall-sown seeds that can cause over-winter seedling mortality from freezing, pathogen attack, and winter drought. Seed coatings may provide a way to overcome both of these barriers to winterfat restoration. Coatings can compress hairs against the …

Understanding The Experiences Of Mothers Of Children With Stunting In Two Egyptian Communities Focusing On The First 1000 Days, Rana Abdelgawad

Theses and Dissertations

Introduction: Egypt’s stunting prevalence is 13% with multiple initiatives and programs tackling child malnutrition. While many of them are promising, not all address the child’s first 1000 days, in addition to missing the cultural aspect for the Egyptian population which affects their dietary practices and health seeking behaviors.

Goal: Determine what challenges mothers face for their child’s nutrition and what learnings from exemplars countries can help Egypt reduce the malnutrition and stunting problem

Aim: Finding insights about the factors influencing child nutrition during 1st 1000 days and what programs can be implemented based on successful past experiences in exemplar countries. …

Artemisinin And Its Derivatives Reactions: Characterization Of The Reaction Products Using Lc/Tof Ms, Kogila Vijayan

Theses and Dissertations

Artemisinin (ART) is a sesquiterpene lactone and a popular malaria drug with potential anticancer properties. In this work, LC/TOF MS was used to investigate the reaction of ART with DNA bases and estradiol. ART-deoxyadenosine and ART-deoxycytidine interactions were studied in the presence of Fe (II) ions. ART-deoxyadenosine and ART-deoxycytidine reaction mixtures gave chromatographic signatures that remained unchanged at room temperature but grew after incubation at 37°C. The change in temperature from room temperature to 37°C was the main driver of adduct formation in these reactions. ART was found to react with Fe (II) ions as observed from several new chromatographic …

Targeting The Warburg And Q Effect: Novel Strategy To Disrupt Cancer Metabolism, Mahmoud Adel Mohamed

Theses and Dissertations

One of the hallmarks of cancer cells is their altered metabolism, which serves their need to grow and proliferate. Cancer cells exhibit a marked increase in glucose consumption (Warburg effect). In addition, cancer cells also exhibit excessive uptake of glutamine, for biomass synthesis and for energy production through mitochondrial substrate level phosphorylation (glutaminolysis pathway). Glutamine metabolism is enhanced upon inhibition of glycolysis, also interference of glutamic metabolism leads to upregulation of glucose metabolism. So, simultaneous inhibition of glycolysis and glutaminolysis presents promising metabolic intervention strategy. In this study, we investigated high dose Vitamin C mechanism of action through MTT assays …

Activity Level Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) And Feeding Habits Of Helicoverpa Zea Larvae After Ingestion Of Hearnpv In Mississippi Soybean, Judge Tyler Fortenberry

Theses and Dissertations

HearNPV was applied to a soybean field and evaluated for residual efficacy at different time intervals (0, 12, 24, 36, 48, and 72 hours) after application in laboratory bioassays with treated leaves. Larval mortality was rated at five, seven and twelve days after larval infestation. Larval mortality increased as the number of days after infestation increased. To evaluate the feeding habits of Helicoverpa zea at the 2^nd and 3^rd instar, HearNPV exposed larvae and untreated larvae were weighed at zero (before diet exposure), four, and seven days. At four days after exposure, larval weight gain of …

Understanding Dietary And Thermal Influences On Invasive Cichlids In Puerto Rico Reservoir Systems, Jacob A. Moreland

Theses and Dissertations

Jaguar Guapote (Parachromis managuensis) and Amphilophus spp. were assessed for effects of temperature on standard metabolic rate (SMR) and lower dissolved oxygen tolerance (LDOT), efficacy of gastric lavage for diet analysis, and diet in Puerto Rico reservoirs. Fish were acclimated to 22°C, 28°C, and 34°C and SMR and LDOT were measured using intermittent respirometers. Jaguar Guapote acclimated to 34°C had the greatest SMR, with 22°C and 28°C having similar SMR values. Amphilophus spp. acclimated to 28°C were similar to fish acclimated at 22°C and 34°C. Fish were resilient to high temperatures, losing equilibrium more rapidly at the coldest temperature, 22°C. …

Identification And Quantification Of Allelochemicals Associated With Weed Suppression In Sweetpotato, Varsha Varsha

Theses and Dissertations

Mississippi ranks among the leading states in sweetpotato production in the US. However, managing weeds in sweetpotato fields presents a significant challenge, and the limited availability of herbicides labeled for use in sweetpotato makes it even more challenging. The widespread and repeated use of herbicides has led to the development of weed resistance. In addition, herbicides are incompatible with the organic production system. Finding sustainable weed management strategies to provide weed control options for organic cultivation and detain the development of herbicide-resistant weeds under conventional crop production is imperative. The natural chemicals released by the plants, also called allelochemicals, can …

Determining The Impact Of Post-Harvest Water Management On Chironomid Abundance, Agrochemical Biomass And Potential Trophic Biomagnification, Mason Thomas

Theses and Dissertations

Agriculture has diminished shorebirds’ natural habitat in the Mississippi Alluvial Valley. Remaining natural stopover sites are supplemented with agricultural fields during the fall and winter. This study evaluates the impact of 4 different post-harvest water management strategies on shorebird food abundance and potential agrochemical biomagnification. Chironomid samples estimated abundance, biomass, and chironomid agrochemical concentration in each field. A risk assessment of agrochemical biomagnification to shorebirds was made across all treatments. Of treatments represented on all study sites, winter treatment had greatest chironomid abundance and biomass. Models indicated that days since flood initiation, start date, and temperature are significant predictors of …

Characterizing Quinclorac-Resistant Smooth Crabgrass (Digitaria Ischaemum) Control And Possible Metabolic Mechanisms Of Resistance, Atikah Dwi Putri

Theses and Dissertations

Quinclorac controls crabgrass (Digitaria spp.) post-emergence in cool- and warm-season turfgrass. A rate response study revealed that two Mississippi smooth crabgrass (Digitaria ischaemum) species (MSU1 and MSU2) are resistant to quinclorac. Following that, field experiments were carried out to evaluate programmatic approaches to control one of these populations. Despite prior study on quinclorac-resistant weeds, to date, quinclorac-resistant smooth crabgrass and its mechanism of resistance have only been reported once in California. The mechanism of resistance of MSU1 and MSU2 relative to susceptible (SMT) was then investigated. The SMT biotype accumulated three times more cyanide than the resistant …

Evaluation Of Italian Ryegrass And Palmer Amaranth Control In Mississippi, Johnson Harris Hughes

Theses and Dissertations

Italian ryegrass is a problematic weed in Mississippi corn production due to the development and proliferation of glyphosate resistance. Studies were conducted to assess Italian ryegrass control prior to planting using herbicides. Effects of fall and spring applied burndown herbicide applications for Italian ryegrass control and subsequent corn grain yield were investigated at the R.R. Foil PSRC in Starkville, MS, at the Coastal Plain Experiment Station in Newton, MS, and the Black Belt Experiment Station in Brooksville, MS on soil textures ranging from sandy loam to silt clay loam. A fall preemergence (PRE) application of S-metolachlor + metribuzin followed …

Evaluation Of Conservation Practices Effect On Water Quality Using The Swat Model, Vivek Venishetty

Theses and Dissertations

The deterioration of water quality due to human-driven alternations has an adverse effect on the environment. More than 50% of surveyed surface water bodies in the United States (US) are classified as impaired waters as per the Clean Water Act. The pollutants affecting the water quality in the US are classified as point and non-point sources. Pollutant mitigation strategies such as the selective implementation of best management practices (BMPs) based on the severity of the pollution could improve water quality by reducing the amounts of pollutants. Quantifying the efficiency of a specific management practice can be difficult for large watersheds. …

Evaluation Of The Relationship Between Hair Coat Shedding Ability, Apparent Forage Digestibility, And Mineral Status In Angus Cattle, Margaret P. Loftin

Theses and Dissertations

The objective of this study was to evaluate the relationship between hair coat shedding ability, apparent forage digestibility, and mineral status in Angus cattle. Fecal samples were collected on fall calving Angus cows for one week in March, May, and July from 2019-2022. Liver and plasma samples were collected in March and July each year. Fecal samples were analyzed for DM, ash, NDF, and ADF while liver and plasma were analyzed for mineral concentration. Data were analyzed using MIXED procedure of SAS with significance declared at P0.05. Interactions were detected for DM, NDF, ADF, and liver Fe concentration. The model …

Effects Of Sampling Methodologies On Mycoplasma Gallisepticum Tissue Populations In Commercial Layer Pullets, Sethulakshmi Kattupparayil Sasidharan

Theses and Dissertations

Mycoplasma gallisepticum (MG) can cause chronic respiratory disease in chickens and infectious sinusitis in turkeys. Impacts of MG infections can include increased morbidity and mortality, decreased egg production, hatchability and feed efficiency. Biosecurity and bio-surveillance remain the primary means of deterrence as the current means of control are not wholly effective. Further applications towards the characterization of MG-related disease control requires proper understanding of the characteristics of MG infections with accurate and efficient quantification of in vivo MG populations. To this end, study was conducted to determine the in vivo MG populations in infected pullets and to determine impact of …

Evaluation Of Nutrient Digestibility Of Weaned Calves From Early And Late Shedding Dams, Jennifer Keele

Theses and Dissertations

Researchers have investigated several factors that could alter fetal growth, including nutrient restriction (Valiente et al., 2021), hair shedding (Gray et al., 2011), and extreme hot and cold temperatures (Davidson et al., 2022). Hot temperatures and increased humidity percentages in the southeast United States caused researchers to investigate the hair coats of Angus cattle in the commercial production setting. An improvement in fiber digestibility and calf birth and weaning weights has been observed in Angus dams that shed 50% of the winter hair coat by May (Gray et al., 2011; Burnett et al., 2021). Our objective of this experiment was …

Expanding The Market Of Biomaterials, Franklin Quin Jr.

Theses and Dissertations

Biomaterials such as wood and bamboo are in high demand as a building material with the push for building with green technology. The wood product industry accounts for approximately 4% of the total U.S. manufacturing GDP (Gross Domestic Product), which is more than $100 billion. The industry supports over 752,000 full-time equivalent jobs, most of which are in rural areas where employment opportunities are limited. The estimated global market value of bamboo is estimated to be $60 billion annually. This research will explore the use of wood and bamboo in different end use products. The objectives of this research will …

Roles Of Limestone Particle Size Ratios And Phytase Levels On Performance, Eggshell Quality, And Bone Health In Post-Peak And Late-Lay Single-Cycled W-36 Laying Hens, Charis Waters

Theses and Dissertations

The objective of this study was to investigate the role of fine (F) and coarse (C) limestone ratios and exogenous phytase at standard and superdosing activity on performance, egg quality, and bone quality of post-peak and late-lay Hy-Line W-36 hens. For post-peak, treatments with 40F:60C at 0 and 400 FTU/kg (standard phytase activity) increased hen-day egg production (HDEP). Treatments with 15F:85C decreased feed intake (FI) but also increased unsaleable eggs (UE) and eggshell-breaking strength (EBS). Treatments with 0 and 400 FTU/kg increased albumen quality and treatments with 1500 FTU/kg increased bone quality and phytate breakdown. For late-lay, interaction effects of …

Modeling Yield And Aboveground Live Tree Carbon Dynamics In Oak-Gum-Cypress Bottomland Hardwood Forests, Suchana Aryal

Theses and Dissertations

The importance of bottomland hardwood (BLH) forests to support the economy through timber production and carbon sequestration is acknowledged; however, their full potential is yet to be explored. This study developed variable density yield models for BLH oak-gum-cypress forests along the US Gulf Coast and Lower Mississippi River Delta. The models, with an adjusted R2 of 98% for cubic foot growing stock volume and 77% for Doyle board foot sawlog volume, are expected to be valuable tools for landowners and managers seeking to make informed decisions about BLH forest management.

A carbon stock model was also developed, and carbon sequestration …

Examining Physiological And Photosynthetic Effect Of Led Lighting On Lettuce And Kale Microgreens, James Travis Blanche

Theses and Dissertations

The objective of these studies was to observe the effects of LED lighting treatments on physiological parameters of lettuce and microgreens. Four different lighting treatments; 1) Physiospec (white), 2) Red, 3) DR9 (25:75 Blue:Red), and 4) Anthospec (at 20/80 Blue:Red); were used in this experiment. Two experiments were conducted: 1) Examining the effects of LED lights on lettuce yield and photosynthetic activity and 2) The effects of switching lighting regiments halfway through the growth cycle on Kale microgreen yield and color. Physiospec lighting was found to promote the highest yield and photosynthetic activity among the four treatments for lettuce. It …

Spatial Conservation Planning In The Southeastern United States: Alignments And Opportunities, Bradly Stewart Thornton

Theses and Dissertations

Conservation managers and planners need the ‘best available science’ to support robust and defensible decisions, ensuring that public resources are appropriately allocated. Spatial planning products and decision-support tools developed for this purpose should enable partner organizations to achieve focus, coordination, and increased effectiveness in their investments and actions. Whereas conservation partnerships have historically created distinct planning tools, there is increasing interest for improved coordination, communication, and unifying biological datasets to improve the cohesiveness of regional management activities. We sought to inform spatial conservation planning efforts in the southeastern United States through the development of species distribution models for focal avian …

Host-Acquired Virus Genes Support An Ancient Antiviral Role Of The Pirna Pathway In Dipterans, Rebecca Christian

Theses and Dissertations

Endogenous viral elements (EVEs) have been recently investigated as a source of transgenerational immune memory. These “viral fossils” are abundant in Aedes mosquitoes and partner with the host’s primary antiviral defense system, the RNA interference (RNAi) pathways. This partnership appears unique to mosquitoes, which encode an expansion of the Piwi endoribonucleases. To interrogate EVE-Piwi partnerships and their role in antiviral defense, I performed a comparative small RNA analysis of two naturally occurring EVE-virus pairs – one in the mosquito Aedes albopictus, and one in the midge Chaoborus americanus. Both express an EVE related to the nucleoprotein of their …

Interactive Effects Of Bark Beetles, Ophiostomatoid Fungi, And Subterranean Termites On Wood Decomposition And The Biogeochemical Cycling Of Pine Forests, Kimberlyn Pace

Theses and Dissertations

A frequent source of pine tree mortality in recent years can be attributed to pine bark beetles and their vectored Ophiostomatoid fungi, an organism that has been observed to attract subterranean termites that preferentially recruit to this downed woody debris. This interaction may significantly modify biogeochemical fluxes in bark beetle mass mortality events, but studies are often limited to singular regions or single pine-dominated ecosystems. Two studies were designed to test the interactive effects of these associations on terrestrial biogeochemical cycles and decomposition processes, the first using replicated field trials in Mississippi, Arizona, and Honduras across two years and the …