Digital Commons Network^™

Ecosystem Services Of Urban Green Spaces In Louisville, Ky., Julia Kachanova

Electronic Theses and Dissertations

Accelerating urbanization poses critical challenges to urban green spaces (UGS), vital for ecological balance and human health. Rapid development often results in fragmented habitats, biodiversity loss, and diminished ecosystem service delivery. There is an urgent need to explore and evaluate novel strategies capable of enhancing urban resilience, such as implementing urban orchards, and managing existing parks and gardens in sustainable ways. This dissertation explores how different forms of urban green spaces (UGS) contribute to the provision and maintenance of critical ecosystem services that support human well-being and urban biodiversity. By analyzing UGS impact on ecosystem service provisioning and long-term sustainability, …

Immunopathogenic Crosstalk Between Cancer And The Kidney: A Central Role For Macrophages As Potential Mediators., Dana Hammouri

Electronic Theses and Dissertations

Cisplatin remains a mainstay in the treatment of solid tumors, yet its therapeutic efficacy is frequently compromised by dose-limiting nephrotoxicity. Approximately 30% of patients receiving cisplatin develop acute kidney injury (AKI), which increases the risk of chronic kidney disease (CKD), a leading cause of morbidity and mortality. Despite extensive preclinical efforts, no FDA-approved therapy currently exists to prevent or treat cisplatin-induced nephrotoxicity (CIN). This in part is due to the reliance of preclinical studies on non-cancer animal models that fail to capture the complex physiological alterations associated with malignancy. To address this limitation, we developed a clinically relevant model in …

Linked Lives In The Riverbed: Integrating Fish Host Dynamics, Community Structure, And Demography For Freshwater Mussel Conservation., Jonathan Patrick Frommeyer

Electronic Theses and Dissertations

Freshwater mussels are long-lived benthic invertebrates that play key roles in nutrient cycling, water filtration, and habitat stability in rivers and streams. Despite their ecological importance, they are among the most imperiled faunal groups in North America, with their persistence increasingly threatened by environmental degradation and disruptions to host–parasite dynamics. This dissertation integrates host ecology, community structure, and demographic modeling to assess population viability and guide conservation priorities for mussel species in Kentucky river systems. The first chapter introduces the ecological context and conservation urgency surrounding freshwater mussels. In particular, emphasizing the need for multi-scale approaches to understand how parasitic …

Remotely-Sensed Urbanization And Local Perceptions Of Change From 1985-2024 In Southern Indiana., Marlea Ferber

Electronic Theses and Dissertations

This study is focused on the land cover change of non-built land cover being transformed into built land cover in two counties in Southern Indiana using mixed methods. Remote sensing was used to identify and quantify land cover change, and interviews were used to understand local perceptions of the physical land cover changes. The study area is situated along the rural-urban continuum with Louisville, Kentucky across the Ohio River. It is important to quantify the amount of land change conversion to built settlement as patterns and rate of urbanization help us to better manage transitions along the rural-urban continuum, but …

A Toi Rna Editing In Three Members Of The Microbotryum Violaceum Fungal Complext And Characterization Of Adar Genes Of Microbotryum Superbum., Shikhi Baruri

Electronic Theses and Dissertations

A-to-I RNA editing is a process that occurs post-transcriptionally. Through this process, adenosine (A) is replaced by inosine (I) in RNAs by adenosine deaminase enzymes that act on the single-stranded RNA. These enzymes, also known as ADARs, act on RNA. The translation and splicing mechanisms subsequently interpret inosine as guanosine (G), which effectively alters genetic information. This kind of RNA alteration can cause both nonsynonymous and synonymous changes in codon, which may have an impact on protein function. A group of over 89 basidiomycete fungal species known as the Microbotryum violaceum complex infects a similarly large group of plant host …

Intestinal Stromal Cells Play A Critical Role In Protection Mediated By Male Microbiota-Derived Metabolites And Androgens Against Disease In Lupus-Prone Mice., Jing Ma

Electronic Theses and Dissertations

Systemic lupus erythematosus (SLE) is a complex autoimmune disease involving broad immune dysregulation. Despite decades of research, most lupus treatments still have limited effectiveness and can cause serious side effects. Both genetic and environmental factors contribute to lupus susceptibility, and a better understanding of how environmental factors influence disease could guide future therapeutic strategies. SLE shows a strong female predominance. Growing evidence implicates the gut microbiota and sex hormones as key environmental contributors to some autoimmune diseases, including lupus. The gut microbiota can influence host immune function, and interestingly, recent studies have revealed sex-bias in microbiota composition and function. Moreover, …

Polymathy: The Foundational Source Of Creativity And Innovation., Michael Araki

Electronic Theses and Dissertations

In an era of mounting complexity and a growing need to transcend siloed thinking, this dissertation advances polymathy as a critical yet underexplored construct in the management and behavioral sciences. Polymathy is framed as an expansive approach to the pursuit, development, and application of knowledge, marked by the conjunction of breadth, depth, and integration. Building on a thought lineage that stretches from Ancient Greece through the Renaissance to the present day, this work shows that polymathy is neither a relic of the past nor an achievement reserved for a few—but a mode of being, thinking, and acting in the world …

Evaluation Of A Forest Restoration Strategy On Small Mammals In Southern Pine Ecosystems, Gage R. Grantham, Jessica L. Glasscock, Christopher M. Schalk, Kathryn R. Kiid, Reuber Antoniazzi

Electronic Theses and Dissertations

Industrial forestry replanted historic native pine forests (e.g., longleaf pine [Pinus palustris] and shortleaf pine [Pinus echinata]) to homogenous, high-density plantations consisting of native off-site species (e.g., loblolly pine [Pinus taeda]) after intensive harvesting for wood products. The contemporary forest structure that remains, consisting of off-site overstory compositions, can potentially serve as an ecological bridge to facilitate a gradual transition to a more desirable canopy species, thereby conserving biodiversity and ecosystem function. Understanding disturbance-sensitive small mammal communities from restoration strategies (retention) can help achieve long-term management goals for ecosystem conservation across larger scales. I …

Using Silvopasture To Mitigate Heat Stress In Grazing Beef Cattle, Sydney L. Lofland

Electronic Theses and Dissertations

This study evaluated the impact of silvopasture on mitigating heat stress in grazing beef cattle by comparing physiological and behavioral responses between shaded and non-shaded pastures. Twenty-two multiparous cows were monitored over a 20-day summer trial in East Texas. Data were collected on respiration rate, heart rate, heat stress scores, and behaviors including eating, ruminating, walking, and resting. Average respiration rates and behavior proportions did not differ significantly between treatments. Afternoon periods showed peak physiological stress across all cattle, but silvopasture appeared to buffer extreme responses. Although limitations such as data gaps and a shortened trial impacted interpretation, findings suggest …

Evaluating Quadrupedal Locomotion In Bats: A Geometric Morphometric Comparison Of Vertebral Adaptations Across Mammals, Jessica Upham

Electronic Theses and Dissertations

Flight is the primary locomotion of bats, while quadrupedal locomotion is not often observed and is widely variable among bats. Frugivorous bats in Pteropodidae are more efficient climbers than frugivorous bats in Phyllostomidae and insectivorous bats in Vespertilionidae, while phyllostomids and vespertilionids are better at walking on horizontal surfaces. The aim of this study is to investigate whether bats with differing modes of nonflight locomotion also exhibit disparity in thoracolumbar vertebral morphology. Using geometric morphometrics, we compared the thoracolumbar vertebral shapes of these bat families with other terrestrial and arboreal mammals. The results revealed distinct vertebral shapes among bat families …

Raptors As Secondary Dispersers Of Mycorrhizal Fungal Spores, Joseph Anderson

Electronic Theses and Dissertations

Animals aid fungal dispersal by consuming fruiting bodies (e.g., truffles) and depositing spores elsewhere. Predators can act as secondary dispersers by preying on small mammals that eat truffles, although it is unclear how this dispersal may vary among species of raptors (hawks and owls) and fungal taxa. We experimentally fed four truffle taxa (with spores varying in size and wall thickness) to six raptor species (with differing gut morphology and acidity) to assess how spore viability and retention time may change between raptor casts and feces. Viability in smaller spores was more negatively affected by acidity compared to larger spores …

Hierarchy In Sensation: Exploring The 40 Hz Auditory Steady State Synchrony In The Primary Auditory And Prefrontal Association Cortices, Deepshila Gautam

Electronic Theses and Dissertations

Auditory processing begins in the cochlea and ascends through brainstem relays to the cortex, where sound features with increasing complexity are encoded. The 40 Hz auditory steady-state response (ASSR) reflects induced gamma synchrony shaped by local cortical circuit dynamics. Disrupted 40 Hz ASSR is a consistent finding in schizophrenia, linked to N-methyl-D-aspartate receptor (NMDAR) hypofunction in inhibitory interneurons, making it a promising translational biomarker. While multiple ASSR generators have been identified, it is not known if these are redundant or represent unique activity. This dissertation investigates regional differences in 40 Hz ASSR across two principal generators: the primary auditory cortex …

An Evaluation Of Key Components Of Natural Resource Camps, Undergraduate Persistence And Success In Natural Resources, Brandy Bishop

Electronic Theses and Dissertations

This study explores the key components that connect natural resource camps, undergraduate persistence, and overall success through gainful employment within the natural resource industry. The aim of this study was to assess early interest and attitudes towards natural resource career pathways and how education interventions shape students’ career outcomes thus leading to overall success. A longitudinal mixed method design was used combining Conservation Careers Camp survey data (n = 39) with institutional records for Forestry majors (n =655) in the Arthur Temple College of Forestry and Agriculture on the Stephen F. Austin State University campus. Quantitative data was analyzed through …

Migratory Patterns Of Juvenile Shortfin Makos (Isurus Oxyrinchus): Evidence Of A Nursery In The Western North Atlantic, Julia A. Crews

Electronic Theses and Dissertations

Shortfin Makos, Isurus oxyrinchus Rafinesque, 1810, are lamnids that have a global distribution in temperate and tropical oceans. Locations of critical early life history events including birthing and nursery areas are unknown or unconfirmed for most populations. The objective of this study was to identify if a nursery area for Shortfin Makos in the northern waters of the Mid-Atlantic Bight using the criteria articulated by Heupel et al. (2007). Satellite tags were used to track the movement of juveniles (<200 cm TL, n=7) up to 5 months. Tag detections (n=882) confirmed that young makos stay in continental shelf waters of the northern Mid-Atlantic Bight off Long Island through the meteorological summer (June–August) and early meteorological fall (September–October) when sea surface temperatures are 18–23°C. There was clear migratory movement from juveniles once sea surface temperatures fell below 15°C. During late fall, some young sharks moved south towards Cape Hatteras, North Carolina, while one shark moved east up to 1,800 km into the open north Atlantic Ocean into meteorological winter. These movement data of juvenile Shortfin Makos combined with multi-year catches and sightings (2018–2024) provide strong evidence for a nursery area in the northern Mid-Atlantic Bight. By identifying a nursery area for Shortfin Makos, knowledge gaps that currently exist for this vulnerable species and support effective management can be closed.

Site Fidelity, Seasonality, Movement, And Fish Associates Of Sand Tigers Carcharias Taurus In North Carolina, Ara L. Mcclanahan

Electronic Theses and Dissertations

Sand tigers Carcharias taurus are mackerel sharks with a disjunct global distribution in tropical and temperate seas. In the northwest Atlantic, sand tigers migrate along the coast of the eastern United States from the Gulf of Maine to Florida and occupy structurally complex benthic habitats. The long-term, underwater camera installation, SharkCam, at Frying Pan Tower, off Cape Fear, North Carolina, USA, sits atop an expanse of hard bottom reef frequented by sand tigers. The citizen-science platform Spot A Shark USA (SAS USA) uses images of sand tigers to identify and track individuals. This study utilized image encounters from SAS USA …

A Tale Of Two Toxicants: Investigating The Interaction Between Hexavalent Chromium And Perfluorooctane Sulfonic Acid., Morgan Elizabeth Delnicki

Electronic Theses and Dissertations

Hexavalent chromium [Cr(VI)] and per- and polyfluoroalkyl substances (PFAS) are environmental contaminants of major public health concern. Despite commonly being found together in contaminated drinking water, no studies have considered the concomitant health effects of Cr(VI) and PFAS, specifically perfluorooctane sulfonic acid (PFOS). In vitro studies using CHO cells assessed the cytotoxicity and genotoxicity of Cr(VI) and PFAS both individually and in combination. Intracellular and extracellular Cr levels were measured with Atomic Absorption Spectrometry. PFOS was found to exacerbate Cr(VI) induced cytotoxicity and genotoxicity. Additionally, a novel in vivo model of studying the hepatotoxicity of Cr(VI) was established. Adult Hartley …

Exploring Hexavalent Chromium Exposure And Lipid Accumulation In Liver Disease., Gabrielle Celine Griffin

Electronic Theses and Dissertations

The prevalence of MASLD has doubled over the past 20 years and continues to rise. Hexavalent chromium [Cr(VI)], a top chemical hazard in U.S. drinking water, is emerging as potential risk factor for liver disease. To study the impact of Cr(VI) and high-fat diet on MASLD, we developed an in vivo model using Sprague-Dawley rats exposed to Cr(VI) in drinking water (0, 0.05, or 0.1 mg/L) and fed normal or high-fat diet for 90 days. High-fat diet significantly increased body mass, plasma lipoproteins, cholesterol, liver injury, and hepatic triglycerides, which were exacerbated by Cr(VI) exposure. Cr(VI) alone increased hepatic chromium …

Analysis Of An Ethanol Sensitive Bmp-Nkx2.3-Fgf Signaling Pathway In Pouch Morphogenesis., Hieu Dai Le Vo

Electronic Theses and Dissertations

Craniofacial malformations lie at the heart of Fetal Alcohol Spectrum Disorders (FASD). While there is growing evidence for a genetic component to FASD, little is known of the cellular mechanisms underlying these ethanol-sensitive loci in facial development. Bone Morphogenetic Protein (Bmp) signaling pathway dependent pouch formation is a key mechanism in facial development. We have previously shown that multiple Bmp mutants are sensitized to ethanol-induced facial defects. However, ethanol does not directly impact Bmp signaling. This suggests that downstream effectors, like nkx2.3 and Fibroblast Growth Factor (Fgf) signaling, may mediate the impact of ethanol on Bmp mutants. Here, I …

Therapeutic Potential Of Sglt2 Inhibitors In A Repeated Love Dose Cisplatin Model., Dianet C. Sanchez

Electronic Theses and Dissertations

Cisplatin is a potent chemotherapeutic, thirty percent of patients develop Acute Kidney Injury (AKI). These patients are ten times more likely to develop chronic kidney disease (CKD). Sodium-glucose-cotransporter-2-inhibitors (SGLT2i), FDA approved for diabetes, has shown protection in multiple mouse models of AKI-CKD. We hypothesize SGLT2i can protect the kidney in a model of repeated low dose cisplatin with/without cancer. B6:129 mice with/without lung adenocarcinoma (Lung-adeno) were treated daily with SGLT2i dapagliflozin (10mg/kg)/vehicle control. After seven days, weekly cisplatin (7mg/kg)/vehicle control was initiated for 3-4 weeks. Following final cisplatin dose, kidney function, injury, fibrosis, inflammation was assessed. SGLT2i treatment attenuated alterations …

Investigating The Multiple Enzyme Complex In The Carotenoid Biosynthesis Pathway, Mercy Mormor

Electronic Theses and Dissertations

In nature, plant carotenoids are 40-carbon isoprenoids with polyene chains that may have double bonds. They are vital components of all photosynthetic organisms, playing several roles in the plant cell, including photosynthesis, pigmentation, phytohormone synthesis, signaling and photoprotection. In this study, we investigated protein-protein interactions among key enzymes involved in the carotenoid biosynthesis pathway using the Bimolecular Fluorescent Complementation (BiFC) assay. Our results revealed several interactions that suggest a coordinated regulation of enzymatic activity within this pathway, highlighting potential regulatory complexes that influence carotenoid production. The study also highlights the pivotal role of Zeta-Carotene Isomerase (Z-ISO) as a key regulatory …

Gut Passage Time In Small Mammals: Influences Of Small Mammal Traits, Digesta Phase, And Particle Morphology, Noah G. Hale

Electronic Theses and Dissertations

Dispersal is crucial in maintaining healthy ecosystems, but little is known about mechanisms influencing fungal spore dispersal by animals. We aimed to develop a more mechanistic understanding of the influence of fungal spore traits and small mammal traits on gut retention time. We fed three species of small mammals (shrew, mouse, vole), which differ in gut morphologies, digestive strategies, and activity a combination of markers including: liquid digesta phase (CrEDTA), small particle (fungal spores with diverse morphologies), and large particles (glitter and beads, representing plant cells and seeds, respectively). We found that hindgut fermenters selectively retained the liquid markers, spores …

Cattle Regenerative Grazing Effects On Bat Activity In Southern Appalachia, Seth Morelock

Electronic Theses and Dissertations

Livestock farming accounts for about 70% of agricultural activity, with continuous grazing as the dominant conventional practice. However, this method often degrades biodiversity and ecosystem health through overgrazing. Regenerative grazing practices offer a potential ecologically sustainable approach to cattle management. Insectivorous bats are known to use agroecosystems for foraging and roosting habitats, offering an opportunity to assess their response to regenerative grazing. Using passive acoustic monitors, we evaluated the response of bats to cattle within regenerative grazed farms in East Tennessee, USA. Overall bat activity declined when cattle entered and exited paddocks, except for the tri-colored bat (Perimyotis subflavus …

"No One Leaves For Free": A Media Analysis Of The Lived Experiences And Cumulative Impacts Of The Flint Water Crisis., Jordan Leigh Gatewood

Electronic Theses and Dissertations

In April 2014, the city of Flint, Michigan changed their municipal water source from Lake Huron to the Flint River. The effects of this change have been felt far and wide as news broke across the nation that this water was contaminated with lead and residents of Flint were getting sick. This research analyzes 170 news articles from three local and three national news outlets over a 10-year span, 2014 to 2024, to determine how community voice is presented in news media to portray the lived experiences and cumulative impacts of the Flint Water Crisis. Applying a Critical Environmental Justice …

Mixture Effects On Metal Accumulation In The Asian Clam, Corbicula Fluminea, Mark A. Huff

Electronic Theses and Dissertations

Field collected Corbicula fluminea were exposed to trace level copper, lead, and zinc with the aim of examining the preferential accumulation between the soft tissue and shell. Metal levels were based on those in a permitted industrial effluent. At 1X effluent and 2X effluent exposure levels, copper was found to preferentially accumulate in the clam soft tissue, lead was found to preferentially accumulate in the clam shell, and zinc was found to excrete back into the diluent after preferentially accumulating in the clam soft tissue. When exposed as a mixture at 1X effluent levels, copper and lead were found to …

Isolation And Characterization Of Siderophore(S) From Pseudomonas Mosselii, Casey J. Stophel

Electronic Theses and Dissertations

Iron is essential for growth of most microorganisms. It functions as an important cofactor in many important biological processes. However, iron found in soil is rendered insoluble and unavailable to microorganisms for use. To overcome this, many bacterial species produce siderophores, a small organic molecule that has high affinity for iron. Siderophores allow for bacterial cells to obtain otherwise insoluble iron. Pseudomonas mosselii, a Gram negative bacterium, was isolated from a local soil sample. P. mosselii was found to produce siderophore(s) under iron restricted environment, however, they have not been characterized. Therefore, it was of interest to isolate, purify and …

The Intersection Of Appalachian Identity And Gambling Behavior, Noah S. Anderson

Electronic Theses and Dissertations

This study examined the relation between Appalachian identity and gambling behavior among students in central Appalachia (n = 395). One-way ANOVAs revealed no significant differences in engagement, F(2, 392) = 0.65, p = .523, or severity, F(2, 392) = 0.33, p = .718, across identification groups. Moderated regression showed that identity did not significantly moderate the engagement–severity relation (B = 0.073, p = .099), though engagement itself was a strong predictor of harm (B = 0.696, p < .001, R² = .521). Negative affect predicted both engagement (B = 0.074, p = .001) and severity (B = 0.069, p = .001), while identity remained non-significant. Logistic regression found that identity predicted gambling engagement (Exp(B) = 1.18, p = .034) only when controlling for severity. These findings relay the importance of empirical efforts in Appalachia and suggest that Appalachian identity may not be an independent risk factor in gambling behavior.

Evaluating Online Autism Information: A Content Analysis Of Language, Quality, And Interventions, Jada R. Beal

Electronic Theses and Dissertations

The internet is a widely used source of autism-related information, yet previous studies demonstrate that the quality, accuracy, and language used in such content remain inconsistent. This study conducted a content analysis of 356 autism-related internet sources obtained from top Google search results, examining their use of neurodiversity-affirming language, the quality of health-related information, and the inclusion of evidence-based interventions. Results showed that medical model language and person-first terminology were more common than neurodiversity-affirming language. Sources targeting caregivers were significantly more likely to use medical model language than those aimed at autistic adults. Only 12.92% of sources included quotes or …

Investigating The Impact Of Psychoactive Plant Alkaloids On Bumblebee Behavior, Skylar Mathieson

Electronic Theses and Dissertations

The relationship between plants and their pollinators is often framed as a food-for-service exchange in which plants provide pollinators with nutrients in exchange for transport of their gametes. However, in addition to essential nutrients, many floral rewards (nectar, pollen) also contain defensive toxins such as alkaloids, with largely unexplored consequences for plant-pollinator interactions. I investigated how three psychoactive and addictive plant alkaloids — caffeine, nicotine, and morphine — affect foraging behavior in generalist bumblebees (Bombus impatiens) using robotic flowers. Each of these chemicals affected pollinator foraging behavior, influencing the number and duration of their visits to flowers in …

Drivers And Consequences Of Changes In Nectar Microbiome Composition Across Spatial And Biological Scales, Daniel A. Barker

Electronic Theses and Dissertations

Microbial communities inhabiting floral nectar, known as the nectar microbiome, are important mediators of plant-pollinator interactions. However, the ecological and environmental factors that shape the composition of these microbial communities remain poorly understood. While previous studies have examined the effects of a few microbial groups, typically independent of one another, on one plant or pollinator species, this dissertation takes a wide-scale approach to explore how abiotic conditions and biotic interaction’s structure microbial communities within floral nectar. Furthermore, I also quantify how variation in microbial richness and identity influences pollinator behavior and plant reproductive success.

This dissertation shows that microbial abundance …

Orchestrated Architecture Dismantling: Borrelia Burgdorferi’S Coordinated Destruction Of Adaptive Immune Responses, Craig A. Land

Electronic Theses and Dissertations

Borrelia burgdorferi represents the most prevalent vector-borne bacteria in North America, affecting ~476,000 Americans annually yet persisting despite robust immune responses. This project reveals spirochetes target adaptive immunity through coordinated lymphatic colonization and precision immune dysregulation.

Using comparative host models (C57BL/6 vs. reservoir Peromyscus leucopus), we demonstrate lymph node colonization within 48-hours, with spirochetes exploiting LYVE-1-positive lymphatic structures as dissemination highways while avoiding the interior of follicular regions. Critically, we identify targeted CD4+ T-cell elimination in germinal center border zones at 21-DPI, precisely when these cells should be coordinating protective immunity. Concurrent upregulation of inhibitory receptor CD32b creates molecular …