Digital Commons Network^™

Refining Treatment Thresholds Of Insect Pests In South Carolina Soybeans Using Simulated Injury And Natural Populations, Adam Whitfield

All Dissertations

Insect pests are a major limiting factor to profitable soybean, Glycine max (L.) Merr., production in South Carolina, yet current economic thresholds are largely based on historical data and may not reflect modern cultivars, production practices, or input costs. Key insect pests in South Carolina can be categorized into three major feeding groups: defoliators, stem feeders, and pod feeders. Defoliating insects include, but are not limited to, soybean looper, Chrysodeixis includens (Walker); velvetbean caterpillar, Anticarsia gemmatalis (Hubner); green cloverworm, Hypena scabra (Fabricius); grasshoppers; and numerous species of beetles. Stem feeders include, but are not limited to, kudzu bug, Megacopta cribraria …

Abnormal Trafficking And Processing Of Multiple Matrix Metalloproteinases Drive Cartilage Defects In Congenital Disorders Of Glycosylation, Chia-Lun Wu

All Dissertations

Congenital Disorders of Glycosylation (CDG) are rare metabolic diseases caused by defects in glycosylation. Despite identification of over 200 CDG types, the mechanisms linking glycosylation defects to diverse clinical phenotypes remain unclear. This dissertation uses zebrafish models of PMM2-CDG and STT3-CDG to redefine CDG pathogenesis, shifting from a simple glycan deficiency model to one involving disrupted cellular spatial organization.

We identify a protease-dependent pathway underlying craniofacial cartilage defects. Specifically, defective proteolytic processing of N-cadherin, a key adhesion molecule in chondrogenesis, is a central driver of pathology. We further uncover an unconventional trafficking mechanism in which ER stress and altered secretory …

The Impact Of Label Material On Perceived Value And Environmental-Friendliness Of Beverages In Returnable Glass Bottles Versus Actual Environmental Impact Via Life Cycle Assessment, Toni Sharp

All Dissertations

With guidance from the EPA to reduce virgin packaging use and alternatively increase reuse, the concept of reusable packaging has re-emerged as a potential sustainable alternative to single-use and recyclable packaging. For businesses, an understanding of the potential environmental benefits of switching from single-use packaging to reusable packaging, along with consumer willingness to pay for sustainable packaging are paramount. Existing literature on willingness to pay (WTP) for ethical or sustainable products typically relies on consumers’ stated preferences found through surveys using hypothetical products and prices. It has been revealed that sustainability claims printed on the label or products in glass …

Diffuse Radiation Controls On Southern Pine Forest Ecosystem Functioning, Jeremy Forsythe

All Dissertations

Diffuse solar radiation, sunlight scattered by atmospheric aerosols and/or clouds, enhances plant photosynthesis through the diffuse fertilization effect (DFE), increasing ecosystem gross primary productivity (GPP) per unit of incoming radiation. Despite this known effect, pine forests of the southeastern United States remain comparatively understudied in the diffuse light literature. This is a critical knowledge gap, as the southeastern United States sequesters more carbon than any other region of the conterminous country (approximately 176 ± 26 Tg C yr⁻¹, or roughly 56% of national forest net carbon exchange), and the region experiences some of the highest biogenic aerosol loads in North …

Neurobiological Mechanisms Of Attention In Adolescents, Virginia Clark

All Dissertations

Adolescence is a transformative developmental period characterized by profound biological, neurological, and behavioral changes. This dissertation investigates the neurobiological underpinnings of attention in adolescents, emphasizing how internal mechanisms influence and individually shape cognitive development through the endosystem. Rooted in the intersection of human development, learning sciences, and cognitive neuroscience, this work argues for a more integrated understanding of attention as a fundamental cognitive function for learning, one that is behaviorally seen but also biologically and neurologically driven. While developmental science has often emphasized external influences such as family, culture, and environment, this work centers on the adolescent’s internal biological systems …

Creatures Of Habit? Impact Of Chick Feeder Tray Location On Feed Consumption At 0-7 Days Of Age, Emily Kate Green

Graduate Theses and Dissertations

Early chick nutrition is critical for establishing target growth performance characteristics in broiler chickens. This study evaluated factors within commercial broiler houses that potentially influence feed consumption during the first 7 days. Three trials were conducted in a 12.2 x 122 m commercial broiler house to assess the effects of house sectioning, spatial barriers, and feedline location. In Trial 1, a one-way experimental design was used in which the house was divided into four equal sections using migration fencing every 30.5 m. House sections served as a fixed factor. Feed was provided using chick trays placed beneath the feed line …

Mechanisms Of Bacterial Glucokinase Inactivation Through Site-Specific Lysine Modification And Chemical Inhibition, Joseph Robert Will Andrews

Graduate Theses and Dissertations

Glycolysis and related metabolic pathways are controlled by various post-translational modifications (PTMs) that affect enzyme activity and metabolic flow. In E. coli, glucokinase (GLK) sits at the crossroads of glycolysis and the pentose phosphate pathway and carries out the first committed step of glycolysis: ATP-dependent phosphorylation of glucose. While it's known that glucose binding causes GLK to close its domains, how phosphate binding, lysine modification, and small-molecule inhibitors regulate GLK's shape and function is still not fully understood. Here, I combine structural biochemistry and enzymology to figure out how phosphate binding, specific mutations, and chemical inhibitors affect E. coli GLK. …

Evaluation Of The Weed Control Efficacy And Potential Economic Returns Of An Autonomous Weeder In Vegetable Production Systems, Claire Plassmeyer

Graduate Theses and Dissertations

Vegetable production requires intensive weed management. Conventional producers rely on herbicide applications to manage weeds effectively at low costs; however, growers are under pressure to minimize chemical use due to environmental concerns and increased incidences of herbicide resistance. Non-conventional systems, including organic and sustainably focused small-scale production, rely primarily on cultural practices and physical weed control methods, which are labor-intensive and costly due to limited labor availability and rising wages. These concerns have prompted the development of autonomous weeding devices, such as unmanned ground vehicles (UGVs) equipped with navigation sensors and implements to provide repeated, high-precision weed control. Compact devices …

Assessment Of The Quality, Practicality, And Economic Viability Of Malted Rice, Bernardo Pontes Guimaraes

Graduate Theses and Dissertations

Climate change threatens the global supply of malting barley, creating a need for sustainable, climate-resilient alternative grains for the brewing industries. This dissertation investigated the chemical, sensorial, practical, and economic viability of using rice as a malting material. First, the malting and brewing qualities of 20 rice samples were evaluated. Results indicated malted rice (MR) had good malting and brewing qualities, including adequate levels of free amino nitrogen (FAN), high amyloglucosidase and limit dextrinase activities. Furthermore, pigmented rice varieties displayed a novel reddish-purple wort color. To identify rice cultivars suited for malting and brewing, the relationship between starch chemistry and …

Developing An Independent Shallow-Water Survey For The Western Rock Lobster Fishery: Tracking Pre-Recruitment Abundance And Habitat Change, Lucy Rudd, Simon De Lestang, Owen Young, Benjamin Hebiton

Fisheries Research Reports

Background

Puerulus settlement has proven to be a good forecaster of legal recruitment of Western Rock Lobster entering into the commercial and recreational fisheries. However, in 2011, this relationship broke down, with average puerulus settlement levels not being reflected in commercial catch rates four years later. Some northern areas showed unexpectedly low catch rates, while other southern areas showed unexpectedly high catch rates. Since this change followed the 2011 marine heatwave, it was assumed that this event changed some component(s) which were important to the growth and survival of juvenile lobsters. It was determined that a better understanding of this …

Effects Of Applying Humic Acid In-Furrow At Potato Planting, Jonathan Tyler Price

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Many products are marketed towards potato farmers that purport to have a positive return on investment for yield and quality. Humic acids, which are comprised of long chained, organic molecules that can be naturally or industrially made, are currently being marketed in this way. The use of these materials is reported to improve nutrient uptake, increase soil health, encourage vigorous growth, and most importantly, increase yields.  From 2023-2025, the in-furrow application of humic acid containing commercial products was evaluated in Pennsylvania on the cultivars ‘Lehigh’ and ‘Waneta’. Black Label Zn, Duo Maxx, Fertiactyl RhiZn, Humi-flex FA, Hydra-Hume, and Monty's Liquid …

Feeding Ecology In Coastal Systems, Randi L. Cannon

Graduate Theses and Dissertations (2019 - present)

Oysters (Crassostrea virginica) are critical foundation species in estuaries, providing numerous ecological and economic benefits. However, oyster populations have diminished worldwide. Effective oyster restoration and aquaculture require a mechanistic understanding of the physiological and environmental factors that govern oyster feeding, growth, and resilience under changing coastal conditions. We investigated how oyster ploidy and environmental conditions influenced oyster feeding and investigated how changes in abiotic conditions affected behavioral performance of oyster drills (Stramonita spp.), a key oyster predator. To better understand feeding responses and behaviors of both predator and prey we 1) used in-situ filter feeding assays to determine if feeding …

Passive Microwave Remote Sensing Of Flash Drought Impacts On Vegetation, Quinton R. Deppert

School of Natural Resources: Dissertations, Theses, and Student Research

In 2002, Dr. Mark Svoboda characterized a new form of drought known as flash drought. Flash drought was defined as a rapid decline in vegetation health caused by severe heat and drought. In recent years, attempts to quantify the impacts of flash drought via precipitation, soil moisture, evapotranspiration, and temperature indicators have proliferated. What has rarely been quantified is what the rapid decline in vegetation health amid flash drought looks like through remote sensing. This is because vegetation health indices like the Normalized Difference Vegetation Index (NDVI) are derived from the visible and infrared regions of the electromagnetic spectrum and …

A Novel Method Of Protein Purification Using Hedgehog Proteins As An Inducible, Self-Cleaving Tag, Antonia Kladias

Undergraduate Honors Theses

Because removing extraneous purification tag sequences from native proteins can be challenging and costly, there is demand for simple all-in-one techniques that directly furnish a tagless, functional protein-of-interest (POI). Current tagless purification systems are based on intein biochemistry; however, intein-based purification requires expensive, specialized resins and the POI often must be fused to the intein’s C-terminus. In this thesis, I present a novel approach for tagless POI purification in which the Drosophila melanogaster hedgehog protein catalytic domain (HhC) is repurposed as a small-molecule inducible, self-cleaving element dubbed Gtag. With Gtag, the POI is fused to the N-terminus of HhC/Gtag with …

Understanding The Role Of Toxs As A Bile Sensing Component Of The Toxrs Virulence Regulatory System In Vibrio Spp., Minje Kim

Dartmouth College Ph.D Dissertations

Pathogenic Vibrio bacteria, such as V. cholerae and V. parahaemolyticus, colonize in the human small intestine to cause severe gastrointestinal disease. During the infection, these bacteria encounter bile salts, antimicrobial cholesterol metabolites secreted into the intestine. Pathogenic Vibrio species have evolved to utilize bile salts as signals to regulate virulence. The signaling depends in part on ToxRS, a conserved co-component transmembrane transcription regulator. ToxRS consists of the transcription factor ToxR and its membrane-tethered binding partner ToxS. ToxS is required for ToxR stability and full transcriptional activity. Although bile salts are known to influence ToxRS-dependent virulence gene expression, the molecular …

Comparing Awssi And Traditional Winter Metrics For Predicting Overwinter Survival Of Juvenile Walleye (Sander Vitreus), Camille N. Shifrin

Honors Program: Senior Projects (Public)

Winter conditions are an important driver of recruitment variability in freshwater fishes, yet winter severity is often characterized using single climate metrics. These simplified approaches may not capture the cumulative stress experienced by fishes during winter. The Accumulated Winter Season Severity Index (AWSSI) integrates multiple components of winter climate and may therefore provide a more biologically relevant indicator of overwinter survival. In this study, we compared AWSSI with traditional winter severity metrics to explain interannual variation in overwinter survival of juvenile Walleye (Sander vitreus) in Harlan County Reservoir, Nebraska. Model comparisons using Akaike’s Information Criterion (AIC) indicated that …

Characterization Of Snrk1 Signaling In Rice Growth, Reproduction, And Stress Responses Using Phenotypic And Omics Analysis, Maria Clara Faria-Bates

Graduate Theses and Dissertations

SnRK1 is an evolutionarily conserved protein kinase belonging to the SNF1/AMPK family that is composed of a catalytic subunit (α) and two regulatory subunits (β and βγ), and it has a major role in adjusting growth in response to the energy status. SnRK1 phosphorylates and alters the activities of enzymes involved in metabolism and regulates gene expression by altering the activity of chromatin-remodeling enzymes or transcription factors. Rice contains three functional paralogs of SnRK1α: OsSnRK1αA (Os05g0530500), OsSnRK1αB (Os8g0484600), and OsSnRK1αC (Os03g0289100). Although SnRK1 is known to play a central role in plant growth and stress responses, the functional specialization of …

The Influence Of Additional Zinc Supplementation During Gestation On The Trace Mineral Concentrations Of Tissues, Milk, And Calf Serum At Birth, Hunter Miller

Animal Science Undergraduate Honors Theses

Minerals are known to play a key role in the immune system, growth, and development of animals. An important part of a calf's life is receiving colostrum immediately after birth, which provides the calf with immunoglobulins and necessary nutrients that are required. Furthermore, the gestation period is another very important aspect of the calf's life where they can take in the necessary nutrition. This study compared how two different supplements fed during the gestation period ultimately affected the mineral concentrations of the colostrum, placenta, calf plasma, and cow liver. The supplements that were provided were a 1) control that provided …

The Effect Of Blue-Green Light On Behavioral Repertoire And Fear Responses In Broiler Chickens, Addie Walker

Animal Science Undergraduate Honors Theses

The broiler chicken industry has increased the number of birds produced each year,

making the mitigation of stressors that affect broiler health and meat quality increasingly

important. New management strategies, like lighting protocols, could help combat stressors and

promote behavioral indicators of positive welfare. This study compared the effects of blue-green

and white light on broiler fear response using a tonic immobility test and behavioral repertoire in

the home pen using continuous focal sampling. Day-of-hatch male broiler chicks (N=600) were

randomly divided into 12 pens (n=50 chicks/pen). The pens had either a white LED light

(control, n=6) or a blue-green …

Enhancing Walleye (Ogaa) Recruitment: Evaluating Assisted Reproduction As A Mitigation Strategy, Douglass Keiser

Biology Graduate Theses

Over the past several decades, cold- and cool-water fish populations across the Upper Midwest, including Minnesota and Wisconsin, have shown troubling signs of decline. Among the most affected is the walleye/Ogaa (Sander vitreus), a species deeply embedded in the ecological balance, cultural identity, and economic vitality of the region, and central to the lifeways, treaty-reserved rights, and resource stewardship of Tribal Nations, including Ojibwe communities across the Upper Midwest. Despite ongoing stocking efforts and harvest regulations, many lake systems have experienced persistent declines in natural recruitment, prompting resource agencies to investigate the underlying causes. One such system is …

Evaluating Management Strategies And Technology To Improve Grazing Efficiency, Thomas E. Aquino

Department of Animal Science: Dissertations, Theses, and Student Research

Increasing land costs and labor constraints continue to challenge beef producers. More intensive practices can increase harvest efficiency; however, many producers are deterred from implementing them due to increased labor and management considerations. Virtual fencing (VF) may provide a reduced labor alternative to traditional fencing for managing intensive grazing. This dissertation evaluated management strategies and VF technology to improve grazing efficiency of stocker cattle systems. In Experiment 1, VF was used to effectively manage groups of steers grazing in adjacent paddocks separated by only virtual boundaries. There was no difference in VF containment (99%) when steers were grazing co-fenced, with …

Optimized Ultrasound Imaging Of Phase-Change Nanodroplets, Charles R Dyall, Dmitry Nevozhay, Andy Liu, Trevor M Mitcham, George J Lu, Konstantin V Sokolov, Richard R Bouchard

Faculty, Staff and Student Publications

Phase-change nanodroplets (PCNDs) continue to generate significant research interest due to their potential to extravasate into tissue, to be targeted for molecular imaging and drug delivery, and to undergo an induced phase-change to "activated" microbubbles (MBs) for ultrasound (US) imaging. To accurately quantify molecular markers, however, one assumes a consistent proportion of PCNDs in a region of interest (ROI) are stably activated and imaged. Herein we present a framework for developing a diagnostic sequence that is optimized for PCND activation uniformity, contrast, and acquisition time. To develop this framework, activation was examined at three scales of increasing complexity: single, adjacent, …

Potential Impact Of Parasites In The Transmission Of Chronic Wasting Disease, Paulina Soto, Rodrigo Morales

Faculty, Staff and Student Publications

No abstract provided.

Growth Hormone Pathway As A Prognostic And Therapeutic Biomarker In Patients With Unresectable Hepatocellular Carcinoma Treated With Radiation Therapy, Joe R Eid, Safa Kaseb, Lianchun Xiao, Ryan Sun, Mahesh Kumar Kannan, Manal Hassan, Asif Rashid, Hop S Tran Cao, Hesham M Amin, Eugene J Koay

Faculty, Staff and Student Publications

Purpose: Radiation therapy (RT) has emerged as an effective local therapy option for patients with unresectable hepatocellular carcinoma (HCC) and is associated with improved overall survival (OS). However, some patients still have poor outcomes after RT, and biomarkers are needed to stratify prognostic groups. High circulating growth hormone (GH) levels promote HCC proliferation and survival and are associated with aggressive disease. In this study, we evaluated whether pretreatment GH levels are associated with OS and progression-free survival (PFS) in patients who underwent RT for unresectable HCC.

Methods and materials: Patients undergoing RT for HCC during 2017-2023 were identified from a …

Decomposition Study Using Pigs In Southeastern Nebraska During The Fall And Winter Seasons, Ryan Bodine

Department of Anthropology: Theses and Student Research

When an individual is found deceased, one of the tools used in the identification process is estimating the post-mortem interval (PMI). This estimate is used to determine how long an individual has been deceased once their remains are found. To estimate an accurate PMI, knowing how decomposition is affected by external factors is key. The transition period from fall to winter in southeastern Nebraska consists of fluctuating temperatures as the seasons transfer from fall to winter. This thesis investigates how decomposition is affected during this transition period while also looking at two different environments that are common in Nebraska, prairies …

Exploring The Biocultural Profile Of The Undocumented Populations Of The Sonoran Corridor: A Skeletal Assessment Of The Prevention Through Deterrence Strategy, Mary A. Vaughn

Department of Anthropology: Theses and Student Research

Over the last thirty years the mortality rate of the undocumented population at the US-Mexico border has risen, requiring methods distinguishing US-born individuals from immigrants to improve the likelihood of identification and repatriation through foreign consulates. Forensic anthropologists with the Pima County Office of the Medical Examiner (PCOME) have advocated for the use of the biocultural profile, combining the biological profile with factors including oral health, osteological stress, and personal effects. The biocultural profile serves two purposes, functioning both as a tool for identification and with which to document structural inequality within communities of origin.

This study examines changes in …

Sensing Rna’S Conformation With A Solid-State Nanopore Device At Various Ph And Temperature, Haopeng Li

Graduate Theses and Dissertations

This study uses solid-state nanopore technology to investigate the stability and dynamics of RNA molecules under thermal stress and pH fluctuations. Two distinct mRNA samples were analyzed: (1) heat shock protein (HSP)-encoding mRNA extracted from Sulfolobus solfataricus P2, a thermophilic archaeon inhabiting extreme environments such as geothermal sulfuric hot springs (pH < 4, temperature range: 65–90°C), and (2) total RNA extracted from White Leghorn chickens, which thrive under standard physiological conditions. ΦX174 virion single-stranded DNA (ssDNA) were included as a comparative reference. Nanopores, fabricated in silicon nitride membranes, were used to electrically characterize the structural properties of individual RNA molecules in solution, close to their native environments. The nanopore membrane separates two chambers containing salt buffer solution, where ionic current is the primary measurement parameter. When a voltage bias is applied across the membrane, ion flow and an ionic current can be measured. Charged RNA molecules driven translocation through the nanopore induces pore resistance changes, resulting in detectable current blockade events. Variations in these events provide insights into RNA secondary structure and conformational dynamics. By systematically altering pH and temperature, this study elucidates the effects of environmental stressors on RNA stability and structural integrity. The findings reveal distinct responses between thermophilic HSP-encoding mRNA and mesophilic RNA, underscoring the adaptive mechanisms of thermophilic RNA under extreme conditions. These results contribute to a better understanding of RNA behavior under stress and establish a foundation for future applications in RNA-based diagnostics and biotechnology development.

Nadh Flim Reveals Cellular Bioenergetics And Mitochondrial Morphology During Drosophila Convergent Extension, Maria Espana Pena

Graduate Theses and Dissertations

Mitochondria are dynamic organelles that can fragment or fuse to support different bioenergetic demands and cellular processes, although the role of mitochondrial fission and fusion during embryonic development is not well understood. Fluorescence lifetime imaging (FLIM) of the mitochondrial cofactor NADH can be used to visualize mitochondrial networks and infer aspects of cellular bioenergetics in a label-free manner. We used NADH FLIM to test whether germband cells undergo changes in cellular metabolism during Drosophila convergent extension (CE)––a process in which hundreds of epithelial cells undergo coordinated intercalation to elongate the embryo. Contrary to our expectations, we did not observe significant …

Lumbopelvic Kinematics And Muscular Co-Contractions In Walking Prior To And Immediately Following A Bout Of Prolonged Standing., Stephanie Cotariu

Graduate Theses and Dissertations

Background: Prolonged standing is a common daily activity in a wide array of occupations, and approximately 44% of sample populations develop low back pain (LBP) during prolonged standing. Prolonged standing-induced LBP developers (“Pain Developers”) are three times more likely to develop clinical LBP and can therefore be considered a pre-clinical LBP population. Changes in typical gait have been observed in LBP patients, and walking has been hypothesized as being protective or preventive against LBP development. However, it is unknown whether Pain Developers exhibit similar kinematic adaptations to chronic LBP patients during common daily activities, such as walking. The exact muscular …

Enrichment Of The Thermophilic Archaea Gearchaeales And Calditenuis In Lab Culture, Walter Saldivar

Electronic Theses, Projects, and Dissertations

Numerous microbes on Earth have yet to be grown in pure cultures and studied in the laboratory. Cultivation-independent genomic methods, such as metagenomics, can help us predict their metabolic capabilities, but cultivation remains valuable for testing these predictions. These uncultivated microbes are very diverse, especially within hot springs. Examples of these uncultivated microbes include the genus Calditenuis (formerly Aigarchaeota Group 1) and the order Gearchaeales; they are often abundant in terrestrial hot springs such as Great Boiling Springs (GBS) in Nevada. Previous work allowed for the establishment of laboratory enrichment cultures inoculated from sediments of GBS containing Calditenuis and …