Digital Commons Network^™

Observing Antibiotic Resistance In Bacterial Co-Cultures Under Simulated Microgravity, Tyler Jenkins, Marina Vaden

Discovery Day - Daytona Beach

Bacteria grow in complex natural environments with multiple factors affecting their growth, metabolism, and physiology. While astronauts are still preparing to travel to Mars, scientists must learn how to simulate a more realistic Martian environment. While a small volume of publications investigates the independent effects of microgravity or Martian regolith on microorganisms (Liao et al., 2025; Allen et al., 2022; Naz et al., 2023; Duri et al., 2025), to our knowledge no current experiments exist on the joint effects of microgravity and Martian simulant on a co-culture. This experiment aims to investigate the effect of a microgravity analog on the …

Instruction Guide, Mark C. Hall

Analytical Biochemistry: A Practical Handbook for Undergraduates

The instruction guide provides useful information for setting up and running the lab activities each week and assessing student preparation, performance, and comprehension.

Apical-Out Lung Organoids: A Platform For Spaceflight And Cf Research, Valeria Jimenez, Ally Schwennesen

Discovery Day - Daytona Beach

A genetic condition known as cystic fibrosis (CF) is brought on by mutations in the CFTR gene, which results in chronic lung inflammation and impaired chloride ion transport. CF bronchial epithelial cells enable direct comparison of disease pathology, while normal human bronchial epithelial (NHBE) cells offer an essential model for researching airway physiology. Realistic modeling of respiratory tissue and its reaction to environmental stressors like microgravity is made possible by the creation of 3D lung organoids from these cells. In this project, we developed apical-out organoids, which expose the apical surface of epithelial cells to the external environment. These organoids …

Investigation Of Biofilm Formation And Osmotic Stress Tolerance Of Nonmotile Escherichia Coli In Simulated Microgravity, Tyler Jenkins

Discovery Day - Daytona Beach

Simulated microgravity presents multiple physiological stressors for astronauts, including bone demineralization, muscle loss, and weakening of the immune system. Bacteria serve as viable model organisms to study physiological changes because of their abundance in the human digestive system and skin. Motility in bacteria plays a significant role in cell survival, but few studies have been conducted on microgravity’s effect on motility phenotypes. While motile strains like Escherichia coli K12 have been studied extensively under microgravity conditions, the effects of simulated microgravity on non-motile strains are largely unknown. To better understand this relationship, the nonmotile E. coli MG1655 strain was inoculated …

Escherichia Coli Concentrations In Sand And Water At Tributary-Influenced Lake Michigan Beaches, Josie Elaine Kuhlman

Masters Theses

Contamination of public recreational water and sand is a human health concern, creating a management challenge for public health officials. Past research has shown that Escherichia coli can persist in sediment and can be washed into recreational water. Currently, beach monitoring practices only utilize E. coli concentrations in water samples to determine beach safety and do not consider potential exposure to sediment/sand concentrations. In this study, I investigated the relationship between E. coli concentrations in water and sand samples, which will aid public health officials in making more informed decisions about beach closures. I utilized culture-based measurements of E. coli …

Enzymatic Synthesis Of Salicylate In Yersina Pestis Proceeds Via Intramolecular Hydroxyl Group Transfer., Clarke Miller

Georgia Journal of Science

The salicylate synthase (YbtS) of Yersinia pestis catalyzes the initial step in the biosynthesis of yersiniabactin, an iron-scavenging siderophore and critical virulence factor. While YbtS is proposed to share a  reaction mechanism with other anthranilate synthase homologs, the exact catalytic pathway has remained unresolved.  In this work, stable isotope (¹⁸O) labeling and mass spectrometry are utilized to clarify the catalytic mechanism of YbtS.  The results of the following set of experiments demonstrate that the salicylate hydroxyl group does not originate from solvent water, directly challenging previously proposed models. Instead, the lack of solvent-labeled oxygen incorporation and the absence …

In Vitro Digestion Modifies Lepidium Meyenii Extract, Altering Its Major Glucosinolates, Lepidilines, Β-Carbolines, And Gut Bacterial Growth, Dominik Tarabasz, Ewa Baranowska-Wójcik, Paweł Szczeblewski, Tomasz Laskowski, Klaudia Gustaw, Marzena Furtak-Niczyporuk, Dominik Szwajgier, Rita Cristina Orihuela-Campos, Henry O. Meissner, Julia Borzyszkowska-Bukowska, Wirginia Kukula-Koch

Journal of Food and Drug Analysis

The tubers of Lepidium meyenii (commonly known as maca) have been used in the Andean cuisine for ages. The study aims to determine the behavior of the extract from the red phenotype of maca in the in vitro gastrointestinal tract model and also to define the overall impact of the extract on the microbiota. Glucosinolates, lepidilines, and a derivative of β-carboline alkaloid, i.e. 1-methyltetrahydro-β-5,6-hydride-carboline-3-carboxylic acid, as representatives of one of the main groups of metabolites were selected for the quantitative analysis after in vitro digestion at every stage of the digestion model. The results showed that lepidilines …

Enhancing Nutrition Communication Skills Through Community-Based Learning To Create Cooperative Extension Resources, Elizabeth Lucas Combs, Anna Cason, Courtney Luecking, Heather Norman-Burgdolf

Journal of Dietetic Education

Strong communication and transferable skills are essential for future dietitians. This Best Evidence Teaching Strategy describes a community-based approach within an upper-level community nutrition course that partnered with the Cooperative Extension Service. Over six weeks, scaffolded assignments emphasized written, oral, and digital media skills, aligning with current trends in scientific communication. Students created information releases, podcasts, and short videos to translate evidence-based nutrition content into accessible formats for public audiences. Collaboration with Extension provided authentic context and motivation, as high-quality projects could be disseminated statewide.

Disability-Related Educational Content In Nutrition And Dietetic Programs: An Exploratory Study, Wendy Medunick, Allison Gomes, Joachim Sackey, Laura Byham-Gray, Jane Ziegler

Journal of Dietetic Education

Background: Health disparities experienced by people with disabilities (PWD) are partly attributed to inadequate knowledge, training, confidence and competence regarding disabilities among health professionals. While registered dietitian nutritionists (RDNs) are key members of the healthcare team, it is unclear how pre-professional nutrition and dietetics (ND) programs prepare future RDNs to care for PWD. This study examined the status of disability-related education within ND programs in the United States. Methods: A descriptive cross-sectional electronic survey was distributed to 570 directors of accredited ND programs. The survey, which adapted questions from a previously validated instrument and published studies, included questions assessing disability-related …

Virtual Reality: The Future Of Didactic And Experiential Education For Nutrition And Dietetics, Michael Holik, Dexter Richardson

Journal of Dietetic Education

The integration of virtual reality (VR) into nutrition and dietetics education provides an innovative answer to challenges in accessing experiential learning. This study examined student perceptions of immersive VR experiences designed to simulate hospital foodservice operations and nutrition counseling sessions, guided by the Diffusion of Innovation Theory (DOI). A quasi-experimental design involved 55 participants who engaged with 360° VR modules featuring interactive elements, avatars representing key healthcare roles, and embedded critical-thinking questions. Results demonstrated strong support for VR’s educational value across DOI’s five key attributes: relative advantage, compatibility, complexity, trialability, and observability. Participants reported enhanced understanding of registered dietitian roles, …

Fraction-Seq: An Integrated Experimental And Computational Workflow For Determining The Localization And Abundance Of Small Non-Coding Rnas In Subcellular Compartments, Siddhartha Shah, Tess Cherlin, Yi Jing, Stepan Nersisyan, Benjamin E. Leiby, Isidore Rigoutsos

Computational Medicine Center Faculty Papers

Small non-coding RNAs (sncRNAs) have garnered considerable attention in recent years, following accumulating evidence of their critical roles in many cellular processes. Among sncRNAs, microRNAs (miRNAs) and their isoforms (isomiRs), tRNA-derived fragments (tRFs), rRNA-derived fragments (rRFs), and Y RNA-derived fragments (yRFs) account for more than 95% of all sncRNAs found in cells. Despite their critical regulatory roles, most sncRNAs remain uncharacterized because their functionalization is a lengthy and challenging undertaking. Knowing an sncRNA's abundance helps prioritize among the various choices, while knowing where it localizes in the cell greatly limits the number and identity of its potential targets and helps …

Unphazed And Phogo: Complete Genome Sequences Of Two Ek1 Cluster Podoviridae Microbacterium Phages Containing Putative Purple Acid Phosphatase Genes, Brett M. Condon, Jacob D. Ariel, Saundra L. Godshall, Drithi Patel, Matthew T. Mcdonald, Susan M. R. Gurney

Student Papers, Posters & Projects

We report two EK1 cluster bacteriophages isolated from soil samples using the host Microbacterium foliorum. EM imaging showed that both exhibit the podovirus morphology. Genome sequencing and annotation showed similarity with many EK1 phage genomes. Our phages contain a putative PAP gene, also expressed in plants.

Changes In Water Quality And Microbiota Over Two Years In Florida Hard Clam (Mercenaria Mercenaria) Hatcheries, Bonnie Getter

Electronic Theses and Dissertations 2020 - Present

This thesis characterized the water quality and bacterial communities in nine hard clam hatcheries over two production years through weekly or biweekly water quality and chemistry monitoring, monthly bacterial plating in the second year of production, and select 16S microbiome sampling at select hatcheries to address production bottlenecks and support the reliable production of high-quality seed for Florida’s growing hard clam aquaculture industry. Logistic regression models showed that water source was distinguished by pH, salinity, alkalinity, and nitrite, whereas geographic location was distinguished by temperature, salinity, nitrate, and calcium; temperature, dissolved oxygen, salinity, and alkalinity distinguished seasons. Vibrio bacteria differed …

Contributions Of Arginine And Nitrosative Stress To Huntington’S Disease Progression, Ian D. Gaudet

Electronic Theses and Dissertations 2020 - Present

Neuroinflammation is a well-established component of Huntington's disease (HD) pathogenesis, yet the intricate molecular mechanisms that govern this process remain a topic of ongoing research and debate. This dissertation elucidates a novel pathway linking arginine metabolism and nitrosative stress to core HD pathology. We found that the arginine transporter SLC7A2 is selectively upregulated in various HD cellular models and patient samples. Our findings reveal that this upregulation drives an overactive inflammatory response, leading to abnormally high inducible nitric oxide synthase (iNOS) induction and subsequent nitric oxide (NO) production, which causes excessive protein nitrosylation and an increase in mitochondrial fragmentation.

To …

Evaluating Pfas And Marine Microbial Interactions In Estuarine Sediments With Varying Urbanization And Assessments Of Microbial Responses To Pfos, Zachary J. Padgett

All Theses

Per- and polyfluoroalkyl substances (PFAS) are a diverse class of synthetic chemicals that have become globally distributed due to their extensive use in industrial and consumer products and their extraordinary resistance to environmental degradation. Their persistence and documented toxicity have made them a growing concern in coastal environments, particularly in estuaries where urban runoff, wastewater, and industrial discharges concentrate these compounds. Estuaries are unique in that tidal mixing and interactions with fine-grained sediments and organic matter promote PFAS retention, while the microbial communities living directly within estuarine sediments are positioned where PFAS preferentially accumulate, creating conditions for prolonged exposure and …

The Aggregation Of Microplastics By Enhancing Extracellular Polymeric Substance Production In Pseudoalteromonas Sp. Ncimb 2021 To Improve Removal Efficiencies In Environmental Matrices, Janelle L. Mercer

All Theses

Microplastics (MP) are ubiquitous in the natural environment and are a growing threat due to their small size and durability. Plastics are released into the environment through improper waste management, wastewater treatment outfalls, industrial spills, agricultural runoff, and landfills. These particles breakdown into secondary MP through degradation pathways. MP, less than 5 mm, require intricate removal techniques from water systems. Filtration techniques, though viable and effective, have implementation constraints due to high cost, maintenance demands, and filter fouling. By integrating coagulation and flocculation processes prior to filtration, MP removal efficiencies can increase, while minimizing operational challenges during filtration. Extracellular polymeric …

Polyphenol Diet And Exercise As Neuroprotection From Effects Of Alzheimer's Disease, Michelle Morgan

Loma Linda University Electronic Theses, Dissertations & Projects

Healthy non-pharmacological lifestyle factors, such as regular physical exercise and a dietary supplementation, have been shown to significantly improve cognitive outcomes over time compared to a more sedentary lifestyle and poor diet. Furthermore, exercise may serve as a potential protective factor in attenuating the effects associated with cognitive decline that are characteristic of neurodegenerative disorders, such as Alzheimer's disease (AD). Further, evidence indicates that certain diet interventions can also attenuate the effects of neurodegeneration and positively impact longevity. Supplementation of polyphenols, such as ellagic acid (EA), which are abundant in pomegranate juice, may help provide neuroprotective benefits and elicit a …

Eusocial Caste Specialization Under Abiotic And Biotic Stress In A Stingless Bee, Tetragonisca Angustula, Kristin M. Robinson

Dissertations

Eusocial insects rely on division of labor to achieve high colony efficiency and provide essential ecosystem services, but specialization may also constrain colony resilience when workers operate near their physiological or behavioral limits under abiotic and biotic stressors. How specialization mediates these responses remains poorly understood, particularly in stingless bees (Tribe: Meliponini). Using the agriculturally relevant stingless bee Tetragonisca angustula, which possesses a specialized soldier subcaste, I investigated how a high degree of worker specialization influences physiological tolerance and predator responses across worker subcastes.

In this dissertation, I quantified variation in thermal tolerance and desiccation resistance among worker subcastes …

Function And Regulation Of Long Polar Fimbriae During Enterohemorrhagic Escherichia Coli Infection, Walter J. Galdamez

Dissertations and Theses (Open Access)

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen that causes severe gastrointestinal disease and hemolytic uremic syndrome. EHEC employs multiple virulence factors to colonize the host intestine, including the locus of enterocyte effacement (LEE) encoded type III secretion system, intimin, and flagella, yet the role of long polar fimbriae (Lpf) in adhesions and infection remains less well understood. Long polar fimbriae can mediate bacterial attachment to host cells in vitro, yet the regulation and function of its two fimbrial operons, lpf1 and lpf2 in vivo remain poorly understood. Preliminary RNA-seq data from zebrafish infected with EHEC reveal that expression of …

Can Kinematics Specify Tool Use Affordances?, Tyler Duffrin

All Dissertations

Object properties such as length, shape, and heaviness, as well as affordance-based properties such as strike-with-ability and poke-with-ability, can be perceived via dynamic touch as functions of inertia tensor invariants. The primary question addressed here was whether people can perceive these same power and precision properties for purely virtual objects, which lack dynamic physical forces. The Kinematic Specification of Dynamics (KSD) principle asserts that missing dynamics are lawfully specified by kinematic (visual) motion patterns, such that kinematic information alone may support successful interactions with virtual objects. In three experiments, we investigated (1) whether virtual reality (VR) users could calibrate to …

Aegic Blogposts - Grain Pricing, Ross Kingwell, Peter Elliott, Chris Carter

Grain and other field crops published reports

The Australian Export Grains Innovation Centre (AEGIC) was an independent, not-for-profit organisation established in 2012 by the Western Australian Government and the Grains Research and Development Corporation (GRDC). Its core mission was to increase the value and international competitiveness of Australia’s multibillion-dollar export grains industry. AEGIC ceased operation at the end of 2025.

Early in its history between 20 to 30 staff from the former Western Australian Department of Agriculture were seconded to AEGIC. Following the formation of DPIRD, AEGIC continued to receive substantial annual funding support from DPIRD.

This publication is a legacy document containing collated AEGIC blog posts …

Aegic Blogposts - Grain Demand In Key Regions And Countries, Ross Kingwell, Sean Cowman, Peter Elliott, Chris Carter

Grain and other field crops published reports

The Australian Export Grains Innovation Centre (AEGIC) was an independent, not-for-profit organisation established in 2012 by the Western Australian Government and the Grains Research and Development Corporation (GRDC). Its core mission was to increase the value and international competitiveness of Australia’s multibillion-dollar export grains industry. AEGIC ceased operation at the end of 2025.

Early in its history between 20 to 30 staff from the former Western Australian Department of Agriculture were seconded to AEGIC. Following the formation of DPIRD, AEGIC continued to receive substantial annual funding support from DPIRD.

This publication is a legacy document containing collated AEGIC blog posts …

Aegic Blogposts - Grain Demand Overview, Ross Kingwell, Paul Meibusch, Jorge E. Mayer, Richard Williams, Peter Elliott, Chris Carter

Grain and other field crops published reports

The Australian Export Grains Innovation Centre (AEGIC) was an independent, not-for-profit organisation established in 2012 by the Western Australian Government and the Grains Research and Development Corporation (GRDC). Its core mission was to increase the value and international competitiveness of Australia’s multibillion-dollar export grains industry. AEGIC ceased operation at the end of 2025.

Early in its history between 20 to 30 staff from the former Western Australian Department of Agriculture were seconded to AEGIC. Following the formation of DPIRD, AEGIC continued to receive substantial annual funding support from DPIRD.

This publication is a legacy document containing collated AEGIC blog posts …

Aegic Blogposts - Grain Demand: Health And Environmental Issues, Ross Kingwell, Nicholas Thorsager, Chris Carter

Grain and other field crops published reports

The Australian Export Grains Innovation Centre (AEGIC) was an independent, not-for-profit organisation established in 2012 by the Western Australian Government and the Grains Research and Development Corporation (GRDC). Its core mission was to increase the value and international competitiveness of Australia’s multibillion-dollar export grains industry. AEGIC ceased operation at the end of 2025.

Early in its history between 20 to 30 staff from the former Western Australian Department of Agriculture were seconded to AEGIC. Following the formation of DPIRD, AEGIC continued to receive substantial annual funding support from DPIRD.

This publication is a legacy document containing collated AEGIC blog posts …

Aegic Blogposts - Climate Impacts On Grain Production, Ross Kingwell, Nicholas Thorsager, David Stephens, Ian Foster, Imma Farre

Grain and other field crops published reports

The Australian Export Grains Innovation Centre (AEGIC) was an independent, not-for-profit organisation established in 2012 by the Western Australian Government and the Grains Research and Development Corporation (GRDC). Its core mission was to increase the value and international competitiveness of Australia’s multibillion-dollar export grains industry. AEGIC ceased operation at the end of 2025.

Early in its history between 20 to 30 staff from the former Western Australian Department of Agriculture were seconded to AEGIC. Following the formation of DPIRD, AEGIC continued to receive substantial annual funding support from DPIRD.

This publication is a legacy document containing collated AEGIC blog posts …

Aegic Blogposts - Grain Industry Productivity, Ross Kingwell

Grain and other field crops published reports

The Australian Export Grains Innovation Centre (AEGIC) was an independent, not-for-profit organisation established in 2012 by the Western Australian Government and the Grains Research and Development Corporation (GRDC). Its core mission was to increase the value and international competitiveness of Australia’s multibillion-dollar export grains industry. AEGIC ceased operation at the end of 2025.

Early in its history between 20 to 30 staff from the former Western Australian Department of Agriculture were seconded to AEGIC. Following the formation of DPIRD, AEGIC continued to receive substantial annual funding support from DPIRD.

This publication is a legacy document containing collated AEGIC blog posts …

Defining The Role Of Spxa1 And Spxa2 In Group A Streptococcus (Gas), Gretchen Anne Morrison

Dissertations and Theses (Open Access)

Group A Streptococcus (GAS) is a human-restricted pathogen whose global incidence has surged in the post-COVID era. The ability of GAS to shift from a colonizing to invasive phenotype depends on coordinated virulence gene regulation in response to host-imposed stressors. The paralogous global transcriptional regulators, SpxA1 and SpxA2, have emerged as central mediators of these adaptive responses; however, the mechanisms by which these regulators influence both global gene regulation in direct response to external stresses and the host response as a result of regulatory changes remain incompletely understood. Using an integrated multi-omic approach, we define the distinct yet interconnected regulatory …

Oxidative Stress Mediated Glutamate Release And Nmda Receptor-Dependent Synaptic Remodeling In Radiation-Induced Cognitive Dysfunction, Thanh Lam

Dissertations and Theses (Open Access)

In children younger than 14 years old, the brain and other parts of the central nervous system are the most common sites for solid tumors. Radiotherapy is an effective treatment for central nervous system (CNS) tumors. However, it often causes a progressive decline in cognitive functions, which is especially devastating for pediatric patients. Although post-mitotic neurons are generally considered resistant to radiation-induced immediate cell death, ionizing radiation causes complex neurochemical and structural changes that damage synaptic integrity. In this study, we examined the molecular cascades following a 10 Gy radiation dose applied to mouse cortical neurons. We found that radiation-induced …

Mutational Analysis Of Domain Functions In The Yeast Decapping Enzyme Dcp2, Jellisa Ewan, Ambro Van Hoof

Dissertations and Theses (Open Access)

In yeast, the major mRNA decay pathway involves deadenylation of the 3’ poly-A tail, followed by decapping of the 5’ m7Gppp cap and subsequent 5’ to 3’ degradation or 3’ to 5’ degradation. This is carried out by Pan2/Pan3 and Ccr4/Not deadenylases, the decapping enzyme Dcp2, and Xrn1 and  RNA exosome exoribonucleases, respectively. The eukaryotic mRNA decapping enzyme complex, Dcp1/Dcp2, is essential in yeast, and deletion of either gene is lethal. However, the deadenylases that act upstream and the 5’ exoribonuclease that act downstream of the decapping step are not, even though they are all highly conserved with no known …

Comparative Assessment Of Developmental Fidelity In Hpsc-Derived Neural Crest Cells, Michael H. Zepeda

Electronic Theses, Projects, and Dissertations

Neural crest cells (NCCs) are a transient, multipotent cell population that contributes to craniofacial structures, peripheral neurons, melanocytes, and smooth muscle. Defects in NCC development underlie a broad range of congenital disorders known as neurocristopathies. Human pluripotent stem cell (hPSC)-derived NCCs provide an evaluable model for studying early human development; however, existing differentiation protocols produce variable outcomes, and no standardized method consistently generates high-fidelity NCC populations. To address this challenge, we compared five published hPSC-to-NCC differentiation protocols using the H9 human embryonic stem cell line. We hypothesized that specific protocols more faithfully recapitulate neural crest development through coordinated regulation of …