Life Sciences Commons^™

Generating Health-Promoting Bioactive Compounds And Nanoporous Materials From Rice Processing Byproducts Via Supercritical Carbon Dioxide Technology, Sumanjot Kaur

Graduate Theses and Dissertations

Rice husk and bran, byproducts of rice processing, are generated in large quantities (~30-40% of the total rice weight) and are discarded as waste or burned in an open field, creating a major disposal problem for the rice industry. However, these byproducts contain high-value compounds, including phytochemicals, fiber, and proteins. Therefore, the goal of this study was to generate high-value food ingredients from rice processing byproducts using a green, innovative approach based on supercritical carbon dioxide (SC-CO2) technology. Specific objectives were to (i) extract health-promoting phytochemicals from rice husk and (ii) convert rice bran into nanoporous materials using SC-CO2. First, …

Radiofrequency And Gaseous Technologies For Enhancing The Microbiological Safety Of Low Moisture Food Ingredients, Surabhi Wason

Graduate Theses and Dissertations

High heat resistance and long survival of Salmonella in low moisture food ingredients (LMFIs) such as spices and seeds are concerning as they are typically consumed without cooking. Therefore, it is challenging to effectively inactivate pathogenic bacteria without negatively impacting the quality of the treated product. This dissertation aimed to develop and evaluate novel intervention technologies: in-package radiofrequency steaming and non-thermal gaseous technologies to improve the microbial safety of LMFIs. The dissertation can be divided into three parts. The first part of this dissertation on the thermal inactivation kinetics of Salmonella and a surrogate, Enterococcus faecium NRRL B-2354on black pepper …

Decrypting The Processes Of Policy Evolution: Comparing Québec And Ontario’S Evolution Of Risk Management Policies, Frederick Clerson Guicherd

Graduate Theses and Dissertations

Through policies or programs, states can influence industries to align with their vision of what a sector should become. However, this vision is subject to influence from actors of the industries which emphasize the importance of the relationship between the state and interest groups. In this dissertation, we observe the evolution of 9 Canadian agriculture risk management programs implemented by two provincial governments between 1990 and 2020 to understand how such programs coped with the new trends in agriculture. Through a review of parliamentary discussions and official documents, we evaluate the factors that justified program evolution based on the combination …

Cullin 3–Mediated Regulation Of Intracellular Iron Homeostasis Promotes Thymic Invariant Nkt Cell Maturation, Emily L. Yarosz, Ajay Kumar, Jeffrey Singer, Cheong-Hee Chang

Biology Faculty Publications and Presentations

The E3 ubiquitin ligase cullin 3 (Cul3) is critical for invariant NKT (iNKT) cell development, as iNKT cells lacking Cul3 accumulate in the immature developmental stages. However, the mechanisms by which Cul3 mediates iNKT cell development remain unknown. In this study, we investigated the role of Cul3 in both immature and mature thymic iNKT cells using a mouse model with a T cell–specific deletion of Cul3. We found that mature iNKT cells lacking Cul3 proliferated and died more than wild-type cells did. These cells also displayed increased glucose metabolism and autophagy. Interestingly, we found that tight regulation of iron homeostasis …

Diversification By Dispersal Out Of The Andes Revealed By A Newly Discovered Hummingbird Clade, The ‘True Brilliants’, Marialejandra Castro-Farías

Biology ETDs

We identified a novel clade with striking biogeographic implications. Unsampled genera, Hylonympha and Sternoclyta, were found to be close to the genus Heliodoxa within the Brilliants. Heliodoxa tend to occur in lower montane habitats, such as the tropical, upper tropical, and subtropical elevational zones of the Andes and the Neotropics. Analysis of geographic and elevational zones showed that genus Heliodoxa and related genera diversified by out-of-Andes dispersal to mountain ranges of Central America, coastal Venezuela, the Pantepui, and southeastern Brazil, since the mid-Miocene. Within the Brilliants, reductions in elevation preceded these geographic expansions. Secondary colonization of the lowlands from …

An Investigation Of Freshwater Turtle Ecology Using Stable Isotopes, Jonathan Duran

Biology ETDs

In 2022 I investigated niche partitioning among native and invasive freshwater turtles across three sites in the Middle Rio Grande using bulk stable isotope analysis. I found high degrees of niche partitioning at sites in which Red-eared sliders (Trachemys scripta) have yet to establish. However, at sites in which red-eared sliders are now the most abundant species they overlapped greatly in isotopic niche with all native turtles, in particular the painted turtle (Chrysemys picta). Using these same techniques, I then examined the trophic interactions between red-eared sliders and their acanthocephalan parasites. My results suggest that acanthocephalans …

Post-Fire Plant Community Response In Subalpine Mixed Conifer Forest, Sasha Escamilla

Biology ETDs

Increased wildfire activity may lead to significant shifts in vegetation dynamics in high elevation mixed conifer forests. These changes raise concerns about the resilience of forests following wildfire, prompting the need for a deeper understanding of post-fire plant community response. We analyzed up to 11 years of post-fire vegetation data from Valles Caldera National Preserve in northern New Mexico to determine how burned vegetation sites were recovering following high severity wildfire, and whether or not plant communities were transitioning to montane grassland. We found burned understory herbaceous communities were not transitioning into distinctive montane grasslands and were instead recovering to …

Thermoregulation In Nocturnal Volant Endotherms Occupying Hot Deserts, William A. Talbot

Biology ETDs

The study of thermoregulation is of growing concern in this era of rapid climate change. Earlier studies such as those pioneered by Scholander and Bartholomew directed focus toward the study of endotherm survival in conditions of cold weather adversity. As techniques evolved in the measurement of parameters quantifying thermoregulation, metabolism and energy allocation, the standardization procedures has increased the comparability of data from diverse taxa. We can now search historical records and current research for explanations to the changes in the distribution, migration, extirpation or survival of animal and plant populations through time. It is increasingly common to observe dramatic …

Resolving The Paradox Of Polyploidy: Underexplored Facets Of Polyploid Plants, Benjamin P. Gerstner

Biology ETDs

Polyploidy, or whole genome duplication, is a common phenomenon in plants, but the establishment and persistence of mixed-ploidy populations remains a paradox. This dissertation explores factors that contribute to the persistence and establishment of mixed-ploidy populations in nature. The first chapter investigates the role of unreduced gametes in neopolyploid establishment and finds that variability in their formation rate can have a significant impact on polyploid establishment and persistence. The second chapter searches for evidence of soil microbes exhibiting ploidy-specificity, a pre-condition for microbe-mediated niche differentiation, a possible stabilizing mechanism contributing to ploidy coexistence. Finally, the third chapter tests for microbe-mediated …

Influence Of Abiotic Drivers And Plant Community Interactions On Bald Cypress (Taxodium Distichum) Seedlings: Implications For Restoration, Victoria Ellis

Biological Sciences Theses & Dissertations

Forested freshwater wetlands are valuable ecosystems that provide habitat for numerous species, sequester carbon, and act as sinks for excess water and nutrients. Historically, these ecosystems have been heavily degraded by anthropogenic activities leading to loss of ecosystem services and a desire to restore freshwater forested wetland habitat. Thus, science-backed approaches for the restoration of freshwater forested wetlands are necessary to ensure restoration goals are met. This body of research employed the Stress Gradient Hypothesis to test whether a multi-species planting approach using Juncus effusus (L.) (soft rush) could facilitate the survival of Taxodium distichum (L.) Rich. (bald cypress) seedlings …

Effects Of Physical Characteristics Of Placebos On Exercise Performance, Owen Sipes

Human Movement Studies & Special Education Theses & Dissertations

Previous research has shown that placebos can impact medical conditions such as irritable bowel syndrome and depression as well as elicit analgesic effects and improvements in certain exercise performances. These placebo responses occur from a variety of alterations to the placebo itself or through verbal suggestion of how helpful the placebo will be. This study aimed to observe whether changing the color and quantity of capsules can induce improvements in both vertical jump and hand grip strength. This deceptive, parallel study consisted of 28 participants, with a mean age of 24.9 (±4.3) years old, that were randomly assigned to receive …

Salinity In Propagation: Germination And Juvenile Acclimatization Of Wetland Halophytes Using Saline Irrigation, Morgan Tomlin

All Theses

The introduction of poor water quality into commercial nursery crop production is predicated on optimized methods that apply saline irrigation without compromising plant success and health. Halophytes have many mechanisms of salt tolerance; however, these are greatly tied to physiological and developmental maturity. Thus, evaluating salt tolerance of halophytic crops (Hibiscus moscheutos and Kosteletzkya virginica) during seed germination and juvenile phases of life may provide insight into the efficacy of integrating poor quality water in horticultural operations.

Four seed priming methods (hydropriming, proline priming, low concentration halopriming, and high concentration halopriming) were evaluated as pre-sowing techniques to ameliorate …

Evaluating The Effect Of Biochar Soil Amendments On Belonolaimus Longicaudatus Populations Damaging Bermudagrass In South Carolina, Malone Thomason

All Theses

Belonolaimus longicaudatus Rau, (1958) (sting nematode) is a prevalent plant-parasitic nematode found in association with Cynodon spp. (bermudagrass) in South Carolina (Ye et al., 2012). Due to the persistence of the pest, long-term management strategies are necessary. Applications of biochar and compost amendments have reduced nematodes in various crop systems, but research on turfgrass systems is limited. The objectives of the studies were to determine: (1) The effect of topdressing or soil incorporated biochar amendments on sting nematode populations, and (2) The effect of topdressing or soil incorporated amendments on turf quality. A field study was established to examine topdressings …

Comparison Of Vegetative Community And Soil Organic Matter Depth Among Reference Sites And Two Restored Wetlands In The Coastal Plain Of South Carolina, Jessica Clark

All Theses

Wetland loss and degradation from agriculture, urbanization, forestry, and mining is a global issue. South Carolina alone has lost over 27% of its wetlands. This historical wetland loss and climatic changes and impacts make restoring wetlands critical for the state. In restoration, understanding the difference in restored and reference wetland’s vegetation and soil organic matter depth can be crucial in assessing the recovery rate and determining environmental functions and services. The main objectives for our research were to determine differences in soil organic matter depth and vegetative community between the restored Brosnan Forest wetlands, the headwater flats and headwater slopes, …

Screening For Dmi And Mbc Fungicide Resistance In Monilinia Fructicola And Evaluation Of Biorational Products For Control Of Brown Rot On Peach In The Southeast United States, William Gura

All Theses

Monilinia fructicola (G. Winter) Honey is a fungal pathogen and is the causal agent of blossom blight, twig blight, green fruit rot, preharvest brown rot, and postharvest brown rot of peach (Prunus persica (L.) Batsch). Especially pre-and postharvest brown rot can have devastating economic impacts and negatively effects yield for peach growers throughout the southeastern United States. The most effective method for the control of pre- and postharvest brown rot is the application of synthetic fungicides during preharvest season. However, the consecutive use of fungicides with the same mode of action potentially give rise to resistance. This thesis focuses …

Patterns And Drivers Of Wiregrass Gap Longleaf Pine (Pinus Palustris Mill.) Woodland Succession As Part Of Restoration Efforts, Armin Weise

All Theses

Longleaf Pine (Pinus palustris) communities are widespread throughout the Southeastern United States with a dominant understory vegetation of wiregrass (Aristida spp.) in most of its range. A small area in central South Carolina that is naturally free of wiregrass is called the “Wiregrass Gap”. Here, the understory vegetation is dominated by bluestems grasses (Andropogon spp. and Schizachyrium spp.) which drive the disturbance regime of frequent low-intensity fire. The successful establishment of these grasses is key for longleaf pine woodland restoration efforts in this region, but few resources detail the ecological drivers at play that enable successful restoration in these longleaf …

Investigation Into The Load Transfer Mechanism Of Trees To Develop An Innovative Foundation Configuration Using 3d Finite Element Modeling, Kaleb Boland

All Theses

This study was inspired by a tree’s reliance on its root system that enables it to withstand a natural disaster, such as an extreme hydroclimatic event or hurricane. This curiosity has led to an investigation into what makes this possible, developing a new and innovative foundation configuration for infrastructure systems, and a new possible construction material and method. This study provides results on a material that does not have conventional testing procedures or standards: a tree root. The trees studied are common to the upstate of South Carolina, which are Pine, Sweetgum, and White Oak. According to the results, on …

Survey And Prevalence Of Palmer Amaranth Herbicide Resistance In South Carolina, Mitchell Williams

All Theses

Palmer amaranth is a troublesome weed for growers to control, not only due to its aggressive growth characteristics that limit row-crop production, but because of its resistance to different herbicide modes of action. The first case of herbicide resistance in Palmer amaranth was detected in 1989 and has since grown to nine different herbicide classes throughout the United States. New herbicide modes of action have not been developed since the 1980s, so proper stewardship of the remaining modes of action is important for effective control of Palmer amaranth. Increased herbicide resistance from states bordering South Carolina have been reported; therefore, …

Leveraging Eco-Evolutionary Models For Gene Drive Risk Assessment, Matthew A. Combs, Andrew J. Golnar, Justin M. Overcash, Alun L. Lloyd, Keith R. Hayes, David A. O'Brochta, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Engineered gene drives create potential for both widespread benefits and irreversible harms to ecosystems. CRISPR-based systems of allelic conversion have rapidly accelerated gene drive research across diverse taxa, putting field trials and their necessary risk assessments on the horizon. Dynamic processbased models provide flexible quantitative platforms to predict gene drive outcomes in the context of system-specific ecological and evolutionary features. Here, we synthesize gene drive dynamic modeling studies to highlight research trends, knowledge gaps, and emergent principles, organized around their genetic, demographic, spatial, environmental, and implementation features. We identify the phenomena that most significantly influence model predictions, discuss limitations of …

The Importance Of Soil Carbon In Large-Scale Shrub Removal Practices In The Chihuahuan Desert, Kathleen Schaeffer

Open Access Theses & Dissertations

Shrub encroachment is a worldwide phenomenon that affects multiple biomes at different ecological and anthropogenic levels. In dryland ecosystems, shrub encroachment is a noted concern amongst land managers, as it can lead to a loss of soil resources and biodiversity. To mitigate the negative effects of shrub encroachment in Drylands, land managers can implement large-scale shrub removal practices. These land restoration practices can shift landscapes to novel ecosystems, where resulting plant communities can vary following treatments. Grass recovery or increasing herbaceous cover is often a primary goal of these treatments, however predicting which sites may show higher grass responses to …

Growth Of Purple Sulfur Bacteria Allochromatium Vinosum On Solid Phase Metal Sulfides As Sulfur And Electron Sources, Hugo Alarcon

Open Access Theses & Dissertations

Purple sulfur bacteria (PSB) are photosynthetic microorganisms known for their vital roles in geochemical cycles, especially the sulfur cycle, within anoxic photic environments. PSB are also key contributors to the nitrogen, carbon, and oxygen cycles. This study focuses on the autotrophic growth of Allochromatium vinosum, a model strain of PSB, that utilize solid-phase metal sulfides (MS) as both sulfur and electron donors. Through characterizing the growth profiles of A. vinosum on pyrite (FeS2), nickel sulfide (NiS), and iron monosulfide (FeS) nanoparticles, respectively, and investigating the bacteria-MS interaction mechanisms, this work expands our current knowledge of the metabolic capabilities and flexibility …

Exploring Undergraduate Research Experiences And Perceptions Of Responsible And Ethical Conduct Of Research (Recr) Education In The Biological Sciences And (Bio)Chemistry Disciplines, Bernice Justina Caad

Open Access Theses & Dissertations

Increasing calls to reform undergraduate (UG) education within science, technology, engineering, and mathematics (STEM) disciplines have emphasized the importance of early exposure to responsible and ethical conduct of research (RECR) education. Historically, RECR has primarily been presented at the post-baccalaureate level, leaving many students without a foundational understanding of what responsible research ethics entails during the course of their undergraduate experience. Over the last decade, course-based undergraduate research experiences (CUREs) have emerged as a promising platform to establish expectations of responsible and ethical conduct through greater accessibility and inclusivity, starting at the freshman level. Interestingly, few studies have examined how …

The Ecological Effects Of Nitrogen Enrichment In Aridlands, Jennifer Holguin

Open Access Theses & Dissertations

Anthropogenic nitrogen (N) deposition is one of the most prominent factors driving global change. Across the globe, N deposition has driven major changes in terrestrial ecosystems, such as declines in plant biodiversity, enhanced exotic plant growth, and changes to biogeochemical processes involved in carbon and nutrient cycling. While noteworthy effort has been put forth to investigate the effects of N deposition on terrestrial ecosystems, a disproportionate number of N addition studies have been conducted in temperate mesic systems. Thus, we lack a holistic and mechanistic understanding of how N deposition impact aridland ecosystems. Additionally, our predictions of the effects of …

Structural Study Of Lsd13 And Lsd14 Type I Modular Polyketide Synthases From The Lasalocid A Biosynthesis Pathway, Dayan Viera

Open Access Theses & Dissertations

Bioactive natural products often possess a complex structure and have a large size which make their chemical synthesis highly challenging. To overcome this challenge, we are developing a biosynthetic method for production of natural products and their analogs. This technology is expected to decrease the synthesis time from years to weeks and reduce the cost of drug production by multiple orders of magnitude. We are investigating the biosynthesis pathway of lasalocid A, an anticancer antibiotic, to develop this technology. Specifically, we aim to characterize the enzymes structurally and biochemically in this pathway, thus paving the way for their rational engineering. …

Genetic Parameters For Heat And Salinity Stress Tolerance In Northern Gulf Of Mexico Eastern Oyster, Crassostrea Virginica, Paul Mcdonald

Master's Theses

Summer mortalities in Gulf of Mexico eastern oysters have been linked to excessively high temperatures, and chronic exposure to low salinity. In this study, the feasibility of improving tolerance to these two stresses by selection was evaluated in common garden experiments employing a pool of 160 families. Heat stress tolerance was evaluated in seed (3.5 months) and adults (14 months) by applying a sustained temperature of 38-39 °C until all oysters expired. Low salinity challenges on juveniles (9 months) and adults (15 months) applied a salinity of 2.5 psu. Survival duration of individual oysters during challenges was recorded and tissue …

Fungal Plant Pathogens Affecting Crops In The Lower Rio Grande Valley, Isabel Martinez

Theses and Dissertations

The Lower Rio Grande Valley (LRGV) located in South Texas has a subtropical and humid environment which is conducive for plant disease. In Chapter 1, Southern blight caused by Athelia rolfsii was collected from Edinburg, Texas in tomato and bean crops. The present study focused on assessing the role of temperature on growth and sclerotia production. We found that there is an optimal growing temperature for both hyphal growth and sclerotia production. In Chapter 2, red rot fungal disease was collected from sugarcane in Texas. Morphology, pathogenicity, effects of temperature, and biocontrol agents were assessed. Isolate morphology closely resembled Fusarium …

Thriving Hives: The Beekeeper's Annual Journal, Andree' Walker Bravo, Shauna Collard Bagley, Sheriden M. Hansen, Jaydee Gunnell

All Current Publications

This beekeeping journal organizes apiary information at your fingertips, along with monthly tasks and tips to help beekeepers be successful with their hives.

Biochemical Characterization Of Ssb1, Ssb2, Sycp3, And Meilb2 In Meiotic Recombination, Garrett Buzzard

All Dissertations

The genome is constantly at risk to damage from environmental and normal cellular processes. Double-strand breaks (DSBs) are one of the most deleterious forms of DNA damage as unrepaired DSBs ultimately result in cell death. Homologous recombination (HR) is a conserved DNA repair pathway that utilizes a homologous chromosome as a template for DNA synthesis to repair the DSBs relatively error-free. HR is active in both mitotic and meiotic cells but meiotic HR is initiated by the introduction of programmed DSBs into the genome. The process of HR repairs the DSBs and results in a physical connection between homologous chromosomes …

Mirna Regulation Of Skeletal Muscle Hypertrophy, Maslyn Greene

All Dissertations

Muscle tissue is vital to animal survival and economically essential to livestock producers. Reduced muscle growth can occur from various reasons, including genetics, nutrition, and the pre and postnatal environment. Understanding the mechanisms behind muscle growth can aid in developing strategies to increase muscle mass. Several methods to increase muscle mass in livestock animals are currently being pursued, including nutrition, hormonal therapy, and genetic selection. One newly developing avenue is using miRNA technologies to change the expression of protein-coding genes. miRNA are a type of RNA that regulate over half of protein-coding gene expression. Here we evaluate muscle characteristics such …

Investigating The Potential Of A Cell-Based Gene Editing Therapy For Inherited Metabolic Liver Disease, Ilayda Ates

All Dissertations

Inherited metabolic diseases (IMDs) affecting the liver are relatively rare but collectively have a prevalence of 1 in 800 live births. These diseases result from autosomal recessive single-gene mutations, leading to organ dysfunction and potentially fatal consequences if left untreated. One potential therapeutic strategy for IMDs of the liver involves using CRISPR-Cas9-induced loss of function mutations. However, translating this approach into the clinic is limited by the need for safe and effective CRISPR delivery methods. Adeno-associated viral vectors (AAVs), commonly used for CRISPR delivery, are associated with significant safety and efficacy concerns, including risks for immunogenicity, off-target mutagenesis, and genotoxicity …