Digital Commons Network^™

Global Erk/Mapk Activation Determines Oncogenic Fitness In Kras-Mutant Pancreatic Ductal Adenocarcinoma, Rachel A. Burge

MUSC Theses and Dissertations

In pancreatic ductal adenocarcinoma (PDAC), ~95% of cases harbor an activating KRAS mutation. The most common KRAS mutations in PDAC are KRAS^G12D (42%), KRAS^G12V (31%), and KRAS^G12R (15%). Patients harboring KRAS^G12R mutations have increased overall survival compared to those with KRAS^G12D/V-mutations. While KRAS^G12D/Vare common in all KRAS-mutant cancers, KRAS^G12Ris only common in PDAC.

KRAS^G12R is unable to activate the lipid kinase PIK3CA, a KRAS effector that is important for tumorigenesis in murine models. To investigate the tumorigenic potential of KRAS^G12R and the mechanisms that enable this mutation …

First Report Of Fibropapillomatosis And Critical Habitat Use In Green Sea Turtles In Curaçao, M. Tripepi, I. J. R. Van Veghel, A. D. Vreugdenhil, E. Brunelli

College of Life Sciences Faculty Papers

Fibropapillomatosis, a disease affecting green sea turtles (Chelonia mydas), has been documented in many regions of the world, including the Caribbean, but has not been scientifically reported in Curaçao until now. The present study utilized VHF telemetry in Caracas Bay, Curaçao, to track green sea turtles, both healthy and affected by fibropapillomatosis, with the objective of ascertaining their foraging locations. VHF telemetry proved to be a pivotal method for assessing habitat use in areas characterized by limited visibility and high boat traffic, conditions that present significant challenges for divers and snorkellers attempting to access the area. The results …

Acute Toxicity Of Arsenate And Arsenite In Two Scleractinian Coral Species: Acropora Cervicornis And Orbicella Faveolata, Cailey Dorman

All HCAS Student Capstones, Theses, and Dissertations

Inorganic arsenic (As), specifically arsenate (As(V)) and arsenite (As(III)) are well-documented toxicants to a range of marine organisms. However, their specific impacts on coral reef species remain largely unstudied. This study is the first to assess the acute and subacute toxicity of inorganic arsenic on two threatened scleractinian coral species, Acropora cervicornis and Orbicella faveolata. Corals were exposed for 96 hours to five analytically verified concentrations and a negative control of either arsenate or arsenite. Toxicity was evaluated through three endpoints: mortality (LC50), coral condition (EC50), and photosynthetic efficiency (IC50). The lethal concentrations to result in 50% mortality (LC50) …

The Trophic Ecology Of The Snipe Eel Avocettina Infans (Anguilliformes: Nemichthyidae) In The Deep-Pelagic Gulf Of Mexico, Emma N. Schindler

All HCAS Student Capstones, Theses, and Dissertations

The Nemichthyidae (snipe eels) are ubiquitous in the deep-pelagic waters of tropical and temperate latitudes, and in some ecosystems are among the dominant fishes. In the deep waters of the Gulf of Mexico, the nemichthyid species Avocettina infans is one of the dominant large predators. This prompted the current study, where an extensive sample set was utilized to characterize the abundance of the family in total, and the vertical distribution and trophic ecology of A. infans specifically. The nemichthyid abundance from 0 – 1500 m was estimated at 1,106.58 individuals per billion cubic meters, the largest portion of which was …

Histologic And Immune Characterization Of Cutaneous Immune-Related Adverse Events Induced By Immune Checkpoint Inhibitors, Omar Pacha, Anisha B Patel, Jonathan L Curry, Cara L Haymaker, Nejla Ozirmak Lermi, Dzifa Yawa Duose, Ken Chen, Joud Hajjar, Aung Naing

Faculty, Staff and Student Publications

Background: Although immune checkpoint inhibitors (ICIs) are efficacious, they often cause immune-related adverse events (irAEs), most commonly cutaneous irAEs (CirAEs). The mechanisms underlying CirAEs remain unclear.

Methods: Attempting to better understand their mechanisms and histology we conducted a prospective study of 15 patients with advanced cancers treated with ICIs who developed grade 2 or higher CirAEs. Clinical and histologic characterization of biopsy specimens of CirAEs was performed. Histologic analysis of patient biopsy specimens were subdivided by epidermal reaction patterns that included spongiotic, lichenoid, and interface dermatitis patterns. A targeted RNA expression assay was used to identify immune markers in CirAE …

Lysosomes As Gatekeepers: How Lic1-Mediated Trafficking Regulates Angiogenesis And Vascular Morphogenesis, Dymonn Johnson

Arts & Sciences Graduate Student Theses and Dissertations

Dynein cytoplasmic 1 light intermediate chain 1 (LIC1, DYNC1LI1) is a core subunit of the dynein motor complex that plays a critical role in cytoplasmic cargo trafficking, including Rab-mediated endosomal recycling and lysosomal degradation. LIC1 interacts with various cargo adaptors, such as RILPL1 and RILPL2, to regulate these processes, and defects in this gene are predicted to impair dynein motor function, Rab binding, and lysosomal trafficking. Here, we identified a dync1li1 zebrafish mutant with a premature stop codon at the exon 12/13 splice acceptor site, that exhibits increased angiogenesis. In vitro, LIC1-deficient human endothelial cells show elevated cell surface levels …

Transcription Fidelity In The Face Of Oxidative Damage, Eastilan Gyiwah Appiah

Theses and Dissertations

It is very important that the process of transcription is correctly carried out in the cell for the faithful expression of the genetic code. However, should mistakes happen, they can result in transcription errors which interfere with the protein-making machinery of the cell. This will result in accumulation of proteins and dysfunctional proteins that have the potential of causing diseases like Alzheimer’s. Oxidative damage caused by hydrogen peroxide is known to cause transcription errors in organisms like yeast. It is therefore important to investigate the extent to which hydrogen peroxide can damage cells.

Integrated Analysis Of Untargeted Liver, Serum Metabolome And Gut Microbiome Following Selenium Deficiency Diet In Selenoh Knockout And Wildtype Mice, Richard Eugene Baird

Theses and Dissertations

Selenoprotein H (SELENOH) is an oxidoreductase located in the nucleolus, and its biochemical levels decrease with selenium (Se) deficiency, as reported in mammalian research. This current investigation aimed to understand the impact of nutritional Se deficiency on gut microbial composition and metabolomic profiles. The Firmicutes/Bacteroidota (F/B) ratio, linked to various health conditions, was balanced for wildtype (WT) mice (1.06). In contrast, selenoh knockout (KO) mice associated with dietary Se deprivation had a significantly (p < 0.002) lower ratio (0.56), suggesting dysbiosis. It is believed that SELENOH levels decreased due to the Se deficient diet, and the selenoh KO mice exhibited alterations in microbial community composition and metabolite profiles, as supported by correlative analyses. With respect to the bacterial communities, significant differences between diets occurred for three taxa, including Akkemansia mucinphila, Bacteroides caecimuris, and Parabacteroides goldsteinii. Candida tropicalis, Malassezia restricta, and Cyberlindnera jadinii were three abundant fungal yeasts. Only Cyberlindnera jadinii exhibited significantly greater relative abundance between genotypes and was more abundant in the selenoh KO versus WT mice. Correlation analyses between bacterial and fungal taxa revealed both positive and negative relationships, but no specific trends were observed. The liver and serum metabolomic data contained similar amino acids, lipids, proteins, and carbohydrates. Using NMR spectroscopy, 112 liver metabolites were detected, while GC-TOF-MS analysis of the serum revealed the presence of 172, comprising both polar and nonpolar compounds. The metabolite levels varied significantly when analyzed using multivariate models such as PCA and PLS-DA (VIP scores), particularly for glucose, taurine, lactate, and UDP-glucose, which are associated with energy production and cellular health. Overall, the Se deficient diet had the most significant impact on the microbial community structure and the concentration of key metabolites within liver tissues and serum. Correlation analyses conducted across studies revealed significant linear relationships between metabolites and the microbiome. However, these differences were associated with bacterial and fungal taxa containing low relative abundances. Based on these findings, further investigation into the impact of SELENOH homeostasis on microbial and metabolite profiles should be conducted using selenoh KO mice under various nutritional Se dietary levels.

Effects Of Psychological Arousal And Relaxation On Muscle Performance, Activation, And Heart Rate Variability During Maximal Muscle Strength And Precision Tasks, Allison Ann Brown

Theses and Dissertations

Psychological arousal plays a vital role in athletic performance, with the optimal point of arousal and performance level varying by task complexity. A common manipulator of arousal is music, which can produce multiple physiological effects. This study investigated whether unfamiliar arousing or relaxing music influences heart rate variability, muscle activation, maximal muscle strength, and muscle precision. Theoretically, if participants are found to have differing muscle performance responses as a result of differing music selections, this would further support the notion that the optimal point of arousal and performance is dependent upon the complexity of the task at hand. Thus, coaches …

Influence Of Diverse Forage Environments On Honey Bee Colony Health, Angus Catchot Iii

Theses and Dissertations

Honey bees are important pollinators that face a multitude of stressors in their environment such as pathogens, parasite pressure, forage availability and pesticide exposure. This study examined how the makeup of different environments and the stressors related to those environments are affecting honey bee health in Mississippi. A field experiment was conducted during the first year of the study across four distinct landscapes ranging from intensively cultivated cropland to predominantly natural forage habitats to assess the impact of landscape availability on varying honey bee colony health parameters. Locations that had cultivated crops within foraging range produced more honey and brood …

Strategic Use Of Exogenous Feed Enzymes And Sodium Bisulfate To Optimize Broiler Production, Spencer Thomas Karn

Theses and Dissertations

Poultry producers must continually evaluate nutritional strategies to enhance broiler performance and sustainability. Chapter II assessed sodium bisulfate (SB) applied to litter, feed, and water across a 42-day grow-out. Applying SB to litter reduced pH, while 0.3% and 0.4% dietary SB improved feed conversion ratio (FCR). Water acidification with SB during the final week did not impair performance, supporting its use as a preharvest intervention. Chapter III evaluated phytase at 500, 1500, and 2000 FTU/kg, with or without protease, in reduced amino acid diets over 56 days. Birds fed a nutrient-adequate diet with 1500 FTU/kg phytase outperformed all reduced-amino acid …

From Gametes To Genes: Genetic Quality Assessment Of Anuran Cryopreserved Spermatozoa And Derived Embryos, Trinity Isabella Kassuhn

Theses and Dissertations

Sperm cryopreservation is an important tool within the suite of assisted reproductive technologies (ART) as it enables long-term storage of genetically valuable gametes. However, knowledge of the diagnostic criteria for assessing sperm quality and the genetic consequences of using cryopreserved sperm in amphibians is limited. This gap has raised concerns in captive breeding and reintroduction programs regarding the potential impact that cryopreserved sperm and the derived embryos may have on a population. The thesis aims to investigate how sperm cryopreservation affects the genetic material in both sperm and resulting embryos, with implications for in situ and ex situ amphibian populations. …

Understanding Pollinator-Forb Interactions And Evaluating Trapping Methods For Pollinator Monitoring In Lawns Of The Southeastern United States, Sara Rose Kirby

Theses and Dissertations

Urban turfgrass landscapes are widespread across the southeastern United States but offer limited ecological value under conventional management. This thesis evaluates the pollinator support potential of ten forb species commonly found in low-maintenance lawns and assesses the effectiveness of two insect sampling methods, sweep netting and pan trapping. Over two years of field surveys, native forbs such as Symphyotrichum divaricatum and Claytonia virginica supported significantly greater insect abundance and diversity than introduced species. Network and modularity analyses revealed that native plants facilitated more specialized pollinator interactions, including those involving oligolectic bee species. In a complementary study, pan traps effectively sampled …

Impact Of Buffered Dry Vinegar And Fermented Onion Juice On The Quality And Shelf-Life Of Fresh Pork Breakfast Sausage, Emily M. Little

Theses and Dissertations

The demand for clean-label meat products has increased interest in natural alternatives to synthetic antioxidants and antimicrobials. This study evaluated the effects of buffered dry vinegar (BDV), fermented onion juice (FOJ), and their combination (CMB) on microbial stability and sensory quality of pork sausage during 9 days of refrigerated storage. Sausages were assigned to control, FOJ (0.5%), BDV (0.5%), or CMB (0.25% each) treatments. BDV and CMB significantly reduced aerobic and psychrotrophic counts by days 7-9, while yeast increased across all treatments over time, reaching ~7 Log CFU/g by day 9. Sensory analysis revealed lower oxidation and off-note intensity in …

Sweetpotato Insect Pests: Virus Vector Management And Rearing, Rachel Emily Morrison

Theses and Dissertations

Sweetpotatoes (Ipomoea batatas) are vegetatively propagated through slips, making them prone to viral buildup. Aphids are insect pests known for transmitting viruses to crops, which reduces yield. This study examined different options for aphid management to reduce the spread of potyviruses: crop borders, crop oils, and insecticides. However, the results of this research showed that treatments were not successful at reducing the spread of the four potyviruses tested. An additional objective was to establish a colony of banded cucumber beetles (Diabrotica balteata) in the laboratory. These beetles are a leaf-feeding and root-feeding pest of sweet potatoes. Two colonies of banded …

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

Theses and Dissertations

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

Feed-Based Strategies To Improve Poultry Production Efficiency, Anna Kathryn Riggs

Theses and Dissertations

The poultry industry continues to make significant strides in efficiency and innovation, particularly through advancements in nutrition. This thesis explores two key areas within broiler nutrition that are essential to supporting sustainable, cost-effective poultry production. First, the potential of a next-generation exogenous carbohydrase enzyme blend containing beta-mannanase and endo-glucanase is investigated when supplemented into reduced-energy, all-vegetable diets based on corn, soybean meal, and corn distillers dried grains with solubles in male broilers over a 42-day grow-out period, including processing (Chapter II). Second, the thesis examines the use of modeling strategies such as cubic, quadratic, kernel and smoothing spline to predict …

Modeling Diameter Distribution Of Loblolly Pine Plantations In Response To Mid-Rotation Thinning Treatments And Assing The Economic Returns In Western Gulf Coastal Plain, Pragya Rijal, Yuhui Weng, Anusha Shrestha, Jason Grogan

Electronic Theses and Dissertations

The influence of thinning regimes incorporating row thinning on diameter distribution and timber product allocation is of considerable importance in the management of loblolly pine (Pinus taeda) plantations within the Western Gulf Coastal Plain. This study utilized data from a thinning study plots established by the East Texas Pine Plantation Research Project across East Texas and Western Louisiana. A two-parameter Weibull distribution was used to model diameter distributions under varying thinning intensities, with parameter estimation conducted using both parameter prediction (PPM) and percentile-based (PRM) methods. The PRM approach demonstrated excellent model performance, with coefficients of determination (R²) ranging …

Unwrapping The Cube Visual Essay, Arthur L. Loeb, C. Todd Stewart

Loeb Design Science: Documents

A visual and conceptual essay illustrating the many faces and properties of the cube.

Influence Of Water Hardness Used In Preparing Wheat Grain For Grinding On The Process Of "Stale" During Storage Of Bakery Products, Suvonqul S. Ravshanov, Ilkhom S. Nurmatov, Ulugbek N. Baltabaev

CHEMISTRY AND CHEMICAL ENGINEERING

The hot climatic conditions of Uzbekistan are favorable for the development of mesophilic bacteria in bread products. The quality of the water used in this process has a great influence. The purpose of the study is to study the effect of water of different hardness on the change in the shelf life of bread during hydrothermal treatment for grinding wheat grain. To determine the freshness (staleness) of bread by rheological properties, the AP-4/2 automatic penetrometer and other devices for analyzing the properties of bread products were used. The conducted analyzes allowed us to conclude from the results of the study …

Microbiome–Immune Interaction And Harnessing For Next-Generation Vaccines Against Highly Pathogenic Avian Influenza In Poultry, Yongming Sang, Samuel N. Nahashon, Richard J. Webby

Food and Animal Sciences Faculty Research

Highly pathogenic avian influenza (HPAI) remains a persistent threat to global poultry production and public health. Current vaccine platforms show limited cross-clade efficacy and often fail to induce mucosal immunity. Recent advances in microbiome research reveal critical roles for gut commensals in modulating vaccine-induced immunity, including enhancement of mucosal IgA production, CD8+ T-cell activation, and modulation of systemic immune responses. Engineered commensal bacteria such as Lactococcus lactis, Bacteroides ovatus, Bacillus subtilis, and Staphylococcus epidermidis have emerged as promising live vectors for antigen delivery. Postbiotic and synbiotic strategies further enhance protective efficacy through targeted modulation of the gut microbiota. Additionally, artificial …

Application And Comparison Of Satellite-Derived Sea Surface Temperature Gradients To Identify Seasonal And Interannual Variability Off The California Coast: Preliminary Results And Future Perspectives, Jorge Vazquez-Cuervo, Marisol García-Reyes, David S. Wethey, Daniele Ciani, Jose Gomez-Valdes

Faculty Publications

The application of satellite-derived sea surface temperature in coastal regions is critical for resolving the dynamics of frontal features and coastal upwelling. Here, we examine and compare sea surface temperature (SST) gradients derived from two satellite products, the Multi-Scale Ultra-High Resolution SST Product (MUR, 0.01° grid scale) and the Operational SST and Ice Analysis (OSTIA, 0.05° grid scale), available through the Group for High Resolution SST (GHRSST). Both products show similar seasonal variability, with maxima occurring in the summer time frame. Additionally, both products show an increasing trend of SST gradients near the coast. However, differences exist between the two …

Radioactive Contamination And Climate Warming Affect Physiological Performance Of Chornobyl Barn Swallows, Zbyszek Boratyríski, Timothy Mousseau, Anders Pape Møller

Faculty Publications

Global warming and degradation of natural habitats are the two main factors causing ecophysiological stress on individuals and risk for biodiversity. Hyperthermia is a common response to stress in homeothermic animals, in particular to heat, pathogens and environmental contamination. Resilience of biological systems to global warming may be deteriorated in polluted habitats. Here we investigated how body temperature of a wild bird, the barn swallow (Hirundo rustica), responded to global warming while simultaneously exposed to radioactive contamination from the Chernobyl accident. Our results showed that both high air temperatures (t = 15.55, df = 335, p <  0.0001) and elevated environmental radioactive contamination (t = 5.18, df = 8.09, p = 0.0008) increased internal body temperature of individuals. The additive effect suggests that birds might suffer hyperthermia in locally contaminated habitat (1.47% body temperature increase) while simultaneously exposed to globally rising temperatures (1.95% body temperature increase), potentially reducing the fitness of individual and the maintenance of breeding colonies. The cumulative and interactive negative effects of multiple stressors, such as those emerging from increasing habitat degradation and climate change, will likely contribute to biodiversity losses globally.

Nutrition Anthropology In Global Malnutrition In Children Under Five, Katherine Michelle Dennison Owens

Doctoral Dissertations and Projects

Food is essential to growth and development for people and nations. Too little or too much food can lead to undernutrition or overweight, both forms of malnutrition. While there have been improvements in undernutrition, overweight is increasing, causing the double burden of malnutrition globally, which is especially true in low-income and middle-income countries. Understanding nutrition anthropology's economic, environmental, and socio-cultural factors is critical to combat malnutrition's burden in different populations. Shaping policies and investments in malnutrition need to be strategic to have a measurable impact on malnutrition improvements. This study identified nutrition anthropology factors using six economic, environmental, and socio-cultural …

Spirituality And Perceived Insider Status: A Study Of Organizational Commitment Of African American Female Leaders In Fortune 1000 Companies, Toni Y. Stubbs

Doctoral Dissertations and Projects

This quantitative study examined the relationships among spirituality, perceived insider status, and organizational commitment among African American female leaders within Fortune 1000 companies. Using a cross-sectional design, the research gathered data from 119 participants through online surveys that included the Spiritual Well-Being Scale (SWBS), the Perceived Insider Status Scale (PIS), and the Organizational Commitment Questionnaire (OCQ). Analyses included Pearson correlations and mediation modeling to address the research questions. The results revealed a strong, statistically significant relationship between perceived insider status and organizational commitment. Although spirituality did not directly predict organizational commitment, it demonstrated a small but significant mediating effect between …

Immunomodulatory Effects Of Gold Nanoparticles: Impacts On Immune Cells And Mechanisms Of Action, Khadijeh Koushki, Prapannajeet Biswal, Geraldine Vidhya Vijay, Mahvash Sadeghi, Sajad Dehnavi, Ngoc Tuyet Tra, Sai Kumar Samala, Mahdieh Yousefi Taba, Arjun Balaji Vasan, Emily Han, Yuri Mackeyev, Sunil Krishnan

Faculty, Staff and Student Publications

Traditional anti-inflammatory medications-such as corticosteroids, biological agents, and non-steroidal anti-inflammatory drugs-are commonly employed to mitigate inflammation, despite their potential for debilitating side effects. There is a growing need for alternative next-generation therapies for symptomatic, unchecked, and/or detrimental inflammation with more favorable adverse effect profiles. The long history of use of gold salts as anti-inflammatory agents and the more recent exploration of gold nanoparticle (AuNP) formulations for clinical indications suggest that the targeted delivery of nanoparticles to inflammatory sites may be a promising approach worth investigating. Coupled with peptides that specifically target immune cells, AuNPs could potently counteract inflammation. Here, we …

Social Networks And The Demand For Credence Agricultural Technologies, Yurani Arias-Granada, Jonathan Bauchet, Jacob Ricker-Gilbert, Kajal Gulati

Department of Agricultural Economics Faculty Publications

Little is known about the adoption of agricultural technologies that enhance unobservable attributes, such as food quality and food safety. Social networks can potentially be a key tool to disseminate information about such technologies, because informal discussions among network members could counter the lack of observability and awareness of the benefits of such technologies. To inform this issue, we conducted a field experiment that included experimental auctions and a lottery to estimate how social networks influence the demand for Aflasafe, a new food safety-enhancing technology, among smallholder farmers in Senegal. Aflasafe is an agricultural input that controls aflatoxins, which are …

Development Of A Physiologically Based Pharmacokinetic (Pbpk) Model And Evaluation Of Antioxidant Capacity For Polypodium Leucotomos Extract, Christopher L. Basel

Doctoral Dissertations and Projects

The purpose of this study was to develop an equation to calculate the approximate concentration of active components in orally administered Polypodium leucotomos fern extract (PLE) and to develop physiologically based pharmacokinetic (PBPK) models for an active component of PLE or its metabolite to address the need for human pharmacokinetics (PK). Model differences based on ethnic groups were also investigated. This was a quantitative study using secondary data. It has been estimated that skin cancers account for approximately 40% of all human cancers and that approximately 13,000 people will die of skin cancer in 2024. People with darker skin experience …

Antifungal Peptides From Casein Milk Of Etawa Crossbreed (Capra Hircus) As Biopreservation Agent For Bread And Molecular Docking Studies, Dian Riana Ningsih, Winarto Haryadi, Rachma Wikandari, Tri Joko Raharjo

Karbala International Journal of Modern Science

Bread without peptide fraction treatment started to grow mold on the fourth day with a total of 24x10⁷ fungi colonies/ml. Meanwhile, the addition of peptide fractions GMC5, GMC6, GMC7, and GMC8 effectively preserved bread for up to 4 days, indicated by no mold growth. The best treatment was the GMC6 peptide fraction on day 8 which grew the least amount of fungus at 7x10⁷ spores/ml. Peptide interaction with the CaATPase receptor Aspergillus sp. was carried out using HADDOCK 2.4. The 3D CaATPase structure prediction resulted in a model with good structural quality. This was supported by residues in …

Scorpions Of The Horn Of Africa (Arachnida: Scorpiones). Part Xlii. Parabuthus Qaraaf Sp. N. From Ethiopia (Buthidae), František Kovařík, Hassan Sh A. Elmi

Euscorpius

No abstract provided.