Digital Commons Network^™

Calibrated Short Tr Recovery Mri For Rapid Measurement Of Brain-Blood Partition Coefficient And Correction Of Quantitative Cerebral Blood Flow, Scott William Thalman

Theses and Dissertations--Biomedical Engineering

The high prevalence and mortality of cerebrovascular disease has led to the development of several methods to measure cerebral blood flow (CBF) in vivo. One of these, arterial spin labeling (ASL), is a quantitative magnetic resonance imaging (MRI) technique with the advantage that it is completely non-invasive. The quantification of CBF using ASL requires correction for a tissue specific parameter called the brain-blood partition coefficient (BBPC). Despite regional and inter-subject variability in BBPC, the current recommended implementation of ASL uses a constant assumed value of 0.9 mL/g for all regions of the brain, all subjects, and even all species.

The …

Noninvasive Multimodal Diffuse Optical Imaging Of Vulnerable Tissue Hemodynamics, Mingjun Zhao

Theses and Dissertations--Biomedical Engineering

Measurement of tissue hemodynamics provides vital information for the assessment of tissue viability. This thesis reports three noninvasive near-infrared diffuse optical systems for spectroscopic measurements and tomographic imaging of tissue hemodynamics in vulnerable tissues with the goal of disease diagnosis and treatment monitoring. A hybrid near-infrared spectroscopy/diffuse correlation spectroscopy (NIRS/DCS) instrument with a contact fiber-optic probe was developed and utilized for simultaneous and continuous monitoring of blood flow (BF), blood oxygenation, and oxidative metabolism in exercising gastrocnemius. Results measured by the hybrid NIRS/DCS instrument in 37 subjects (mean age: 67 ± 6) indicated that vitamin D supplement plus aerobic training …

Improving Safety Performance Of Highway Maintenance Crews Through Pre-Task Safety Toolbox Talks, Zamaan Al-Shabbani

Theses and Dissertations--Civil Engineering

The dangerous work environment in the construction industry and the inherent high risks associated with construction work make it the focus of safety training and regulations. Highway construction and maintenance has unique hazards but seemingly less directly applicable safety standards, regulations, and programs. Department of Transportation (DOT) employees working in highway maintenance are exposed to a variety of unique hazards specifically associated with their work and not relating to the adjacent traffic. Yet, highway construction and maintenance work has not received sufficient attention in terms of safety research and programs. The lack of safety training and education in highway construction …

Use Of Functionalized Bimetallic Membranes For Treatment Of Contaminated Groundwater At A Hazardous Waste Site In Kentucky, Lucy C. Pacholik

Theses and Dissertations--Civil Engineering

Providing access to clean drinking water will continue to be a challenge for civil engineers for generations to come. Since many communities around the world rely on groundwater as a source of drinking water, remediation technologies must be implemented at sites where groundwater contamination exists due to years of mismanagement of hazardous waste. Using nanosized zero-valent metals such as iron and zinc embedded within and on the surface of functionalized (PAA) membrane filters has shown to be an effective dechlorination technique for contaminated groundwater. Introducing a noble metal such as Pd or Ni increases reaction rates by acting a catalyst …

Decomposing A Watershed’S Nitrate Signal Using Spatial Sampling And Continuous Sensor Data, Evan Clare

Theses and Dissertations--Civil Engineering

Watershed features, physiographic setting, geology, climate, and hydrologic processes combine to produce a time-variant nutrient concentration signal at the watershed outlet. Anthropogenic influences, such as increased agricultural pressures and urbanization, have increased overall nutrient loadings delivered to the fluvial network. The impact of such increased nutrient loadings on Kentucky’s drinking water remains a potential threat to the region.

By coupling spatial sampling of nitrate concentrations in surface water with contemporary nutrient and water quality sensor technology, a decomposition of the Upper South Elkhorn watershed’s nitrate signal and an estimation of source timing and loading in the watershed was completed. The …

Biological Selenium Control: Selenium Reduction By Shigella Fergusonii Strain Tb42616 And Pantoea Vagans Strain Ewb32213-2 In Bioreactor Systems, Yuxia Ji

Theses and Dissertations--Civil Engineering

Se(VI) and Se(IV), as the two major species of selenium in water, are toxic to aquatic lives and may cause adverse health effects to humans at high levels. Biological reduction of Se(VI) is a two-stage process first from Se(VI) to Se(IV) and then from Se(IV) to Se(0) with potential accumulation of the more toxic Se(IV) due to the slower rate of the second stage.

Selenium reduction was first evaluated with batch cultures of Shigella fergusonii strain TB42616 (TB) and Pantoea vagans strain EWB32213-2 (EWB) isolated in our laboratory from sludge and coal slurry sediment samples, respectively. In order to facilitate …

Synthesis, Design, And Evaluation Of The Fluorescent Detection Of Polychlorinated Biphenyls(Pcbs) In Aqueous System, Irfan Ahmad

Theses and Dissertations--Chemical and Materials Engineering

The exposure to halogenated persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), has been linked to numerous inflammatory diseases, including diabetes, cancer and lowered immune response. PCBs have low solubility in water, and they interact with other contaminants, making their detection quite challenging. While, there have been several attempts at improving the ease of detection and sensing of PCBs, gas chromatography-mass spectrometry (GC-MS) remains the gold standard. However, despite its ubiquitous use, GC-MS is a challenging technique that requires high skill and careful sample preparation, which are time-consuming and costly. As such, there is still a need to develop …

Bioinformatic And Experimental Analyses Of Axolotl Regeneration, Nour W. Al Haj Baddar

Theses and Dissertations--Biology

Salamanders have an extraordinary ability to regenerate appendages after loss or amputation, irrespective of age. My dissertation research explored the possibility that regenerative ability is associated with the evolution of novel, salamander-specific genes. I utilized transcriptional and genomic databases for the axolotl to discover previously unidentified genes, to the exclusion of other vertebrate taxa. Among the genes identified were multiple mmps (Matrix metalloproteases) and a jnk1/mapk8 (c-jun-N-terminal kinase) paralog. MMPs function in extracellular matrix remodeling (ECM) and tissue histolysis, processes that are essential for successful regeneration. Jjnk1/mapk8 plays a pivotal role in regulating transcription in response to cellular stress stimuli, …

Variability In Groundwater Flow And Chemistry In The Houzhai Karst Basin, Guizhou Province, China, Joshua M. Barna

Theses and Dissertations--Earth and Environmental Sciences

Understanding how karst aquifers store and transmit water and contaminants is an ongoing problem in hydrogeology. Flowpath and recharge heterogeneity contribute to the complexity of these systems. This thesis explores karst-conduit connectivity and water chemistry variability in the Houzhai catchment in Guizhou province, China. Artificial tracer tests were conducted during both the monsoon and dry seasons to understand temporal variability in connectivity and water velocity between karst features. Multiple flowpaths through the catchment are activated during the monsoon season and partially abandoned during the dry season. Additionally, gradient reversals during monsoonal high-flow events and as a result of pumping can …

The Forestry Reclamation Approach: Measuring Sediment Mass Accumulation Rates In Reclaimed Mine Lands And Naturally Regenerated Logged Forests Of Eastern Kentucky, William E. Bond

Theses and Dissertations--Earth and Environmental Sciences

The spread of surface coal mining has resulted in loss of forests in the Appalachian region. The Forestry Reclamation Approach (FRA) was developed to provide guidance for restoring forests on reclaimed mined land. This study hypothesizes that the FRA will result in larger magnitude of sediment accumulation rates in reclaimed mine sites compared to those reclaimed using grassland reclamation. Three sediment cores and six trenches were sampled within four reclaimed mined and three previously logged sites in eastern Kentucky. Samples were processed for radionuclides, grain-size, stable isotopes (δ¹³C), and POC. LIDAR data were used to identify valley …

Where We Belong: Spatial Imagining In American Women’S Life Narratives, 1859-1912, Gokce Tekeli

Theses and Dissertations--English

Where We Belong: Spatial Imagining in American Women’s Life Narratives, 1859-1912, studies three marginalized and disadvantaged American women’s self-life narratives during a transitional period in American history. In this dissertation, I am taking an interdisciplinary approach. Where We Belong borrows from social geography, new materialism, and autobiography studies in order to complicate critical discussions of women’s space and place in nineteenth-century women’s self-life narratives. Each chapter of Where We Belong presents a case study with the goal to provide a broader understanding of women’s strategies of belonging due to and despite their spatial exclusions. The overarching emphasis in each …

Identity, Spectacle, And Embodiment In Social Protest, Craig Alan Crowder

Theses and Dissertations--English

This dissertation examines the way rhetorical performances of identity function within a social movement. Examining the University of Kentucky chapter of a campus activist organization, United Students Against Sweatshops, I argue that embodied performances of identity often leverage spectacle in disruptive ways and work not only to solidify activists’ identities as part of a social movement but ultimately help to create solidarity within the movement, thereby working toward movement objectives. Historically under-examined in social movement literature in the rhetoric and composition tradition, identity performance examples are taken from an oral history project and archival materials to show how identity is …

Nineteenth-Century Pets And The Politics Of Touch, Valerie L. Stevens

Theses and Dissertations--English

Nineteenth-Century Pets and the Politics of Touch examines texts of the era in which both humans and animals find empowerment at the point of physical encounter. I challenge contemporary perceptions of human-pet relationships as sweetly affectionate by focusing on touch. I uncover an earlier interest in the close reciprocal relationships between human and nonhuman animals, arguing that these nineteenth-century thinkers presented what I call a “politics of touch,” in which intimate and often jarring physical encounters allow for mutuality and autonomy. I first turn to Charlotte Brontë’s Shirley (1849) and protective violence, a condoned ferocity that frequently unites and guards …

But What Has Helga Crane To Do With The West Indies? Plantation Afterlives In The Black Atlantic, Rachel Mckenzie Carr

Theses and Dissertations--English

“But What Has Helga Crane to Do with the West Indies? Plantation Afterlives in the Black Atlantic” situates the emergence of the southern gothic in modernist American and Caribbean works as a response to the shifting cultural narrative of the plantation in the twentieth century. In this project, I argue that the plantation seeps out of its place and time to haunt landscapes it may never have touched and times in which slavery is long over. While the plantation system is broadly recognized as a literary, political, and cultural force in nineteenth-century literary studies, I conceive it is also a …

Fathers And Sons In Modern British, Irish, And Postcolonial Fiction, Alison Hitch

Theses and Dissertations--English

In this dissertation, I examine the portrayal of filial relationships in the fiction of James Joyce, Hanif Kureishi, and Zadie Smith. I assert that each of these authors, albeit in different ways, uses the archetypal father and son relationship to interrogate the formation of national identity and the concept of national belonging in modern, anticolonial or postcolonial cultures, including Ireland at the dawn of the twentieth century and Britain in the late twentieth century. Chapter one focuses on Joyce’s A Portrait of the Artist as a Young Man (1916) and Ulysses (1922). I argue that rather than solely bonding in …

History Speaks From The Soil: A Case Study Of Commons Enclosure In The Clearance Era On North And South Uist, Anna Rachel Herrington

Theses and Dissertations--History

This thesis argues that commons enclosure in the Clearance Era on the Uist island group in the Outer Hebrides of Scotland was a direct result of the Clearances on those islands in the 18^th and 19^th centuries and how the enclosure of commons on these islands was catastrophic to those communities who had functioned, worked, and thrived in those regions for millennia. Commons and commons systems are those resources such as land, water, and produce either from agriculture or natural harvesting which contribute to human habitation and existence in a particular geographic area. Commons and commons systems on …

Agricultural Livelihoods In Harlan County: A Case Study Approach Of Two Farms, Heather Kinney

Theses and Dissertations--Community & Leadership Development

This thesis explores agricultural livelihoods in Harlan County with two case studies in order to challenge dominant narratives about Eastern Kentucky. Harlan County, and Appalachia more broadly, is often written about in terms of its relationship to extractive industries. Absentee landownership in Appalachia has been well documented, especially in the case of coal counties. However, the relationship between extraction and agricultural livelihoods in Appalachia warrants more attention. The story of agricultural livelihoods in the region is often pushed to the periphery much like the practices of “hillside” farming. While geography makes much of the land unsuitable for farming in Harlan …

Investigating The Feasibility Of Using Mesoporous Silica Particles To Deliver Glucose During Anaerobic Fermentation, Megan E. Walz

Theses and Dissertations--Biosystems and Agricultural Engineering

The study presented herein investigated a potential low-energy method to separate and concentrate glucose from a lignocellulosic hydrolysate. The motivation for this method was twofold: 1) to provide the fermentation microorganism an optimal glucose concentration and 2) to supply a fermentation media free of inhibitory compounds. Two sizes of porous silica particles (with 7 nm and 2.3 nm pores) were synthesized and their ability to adsorb glucose from solution confirmed. Next, the ability of two different microorganisms, Saccharomyces cerevisiae and Streptococcus bovis, to utilize sugars adsorbed to the porous silica particles was investigated.

Both the 7 nm and 2.3 …

Evaluation Of Air Movement In Equestrian Facilities And On Equine Athletes, Staci Elaine Mcgill

Theses and Dissertations--Biosystems and Agricultural Engineering

Ventilation and air movement are important aspects of animal agriculture and is frequently neglected in equine facilities. This paper discusses three different studies that examine different components of ventilation and air movement. One is a fan orientation study which examines how fans impact the stall environment, the second is a cooling study questioning whether forced air speed across a horse increases the rate of cool out after intense exercise, and the last is a survey examining ventilation, air quality, and health concerns in indoor arenas.

The stall fan study took place over two summers with the goal of determining how …

Design And Testing Of A Wind Energy Harnessing System For Forced Convective Drying Of Grain In Low Wind Speed, Warm And Humid Climates, Francis Akumabi Agbali

Theses and Dissertations--Biosystems and Agricultural Engineering

Forced convective drying using a wind turbine mechanically connected to a ventilation fan was hypothesized for low cost and rapid grain drying in developing countries. The idea was tested using an expandable wind turbine blade system with variable pitch, at low wind speeds in a wind tunnel. The design was based on empirical and theoretical models embedded in a graphical user interface (GUI) created to estimate airflow-power requirements for drying ear corn. Output airflow (0.0016 - 0.0052 m³kg^-1s^-1) increased within the study wind speed range (2.0 - 5.5 m/s). System efficiency peak (8.6%) was …

Rapid No• Measures In Rat Nucleus Accumbens And Frontal Cortex Following Nasal Administration Of Nitroglycerin, Victoria A. Scott

Theses and Dissertations--Medical Sciences

Nitric Oxide (NO) is a powerful endogenous free radical that has numerous biological functions including vasodilation and serves as a post synaptic second messenger in the central nervous system (CNS). Numerous studies implicate NO• involvement in CNS disorders such as schizophrenia and drug abuse. These studies address the direct in vivo determination of an FDA-approved NO• donor (nitroglycerin) on extracellular levels of NO• in the frontal cortex and core of the nucleus accumbens in a lightly anesthetized rat. State-of-the-art in vivo amperometric recording techniques coupled with a novel 4-channel low noise pre-amplifier system and new generation microelectrode arrays (MEAs) will …

The Stimulation Of Dendritic Cells By Cationic Lipids, John Peyton Bush

Theses and Dissertations--Medical Sciences

The discovery that cationic lipids can independently stimulate the immune system has generated interest in their potential as vaccine adjuvants. Here, we show that the cationic lipid R-DOTAP can independently stimulate type 1 interferon production in dendritic cells in both primary culture and immortalized cell culture. Levels of type 1 interferon production are cell line-dependent and limited in vitro by lipid-induced cell death. We show that cationic lipids can independently activate TLR-7 and TLR-9, suggesting a mechanism for type 1 interferon induction. This TLR-stimulatory activity is not restricted to R-DOTAP and can be extended to other similar cationic lipids in …

Integrin Α5Β1 As A Novel Target With The Small Peptide, Atn-161, In The Treatment Of Ischemic Stroke, Danielle Nichele Edwards

Theses and Dissertations--Neuroscience

Stroke is the 5^th leading cause of death and the leading cause of disability in the United States, but there are only two available therapies, tissue plasminogen activator and endovascular thrombectomy. As both therapies focus on removal of the clot, the subsequent pathologic processes, i.e. inflammation, cerebrovascular breakdown, ATP depletion, etc. are left untreated, contributing to worsened patient outcome. Many clinical trials have unsuccessfully attempted to address these mechanisms. The blood-brain barrier (BBB), a system of non-fenestrated endothelial cells, extracellular matrix, and astrocytic endfeet, is significantly impacted after ischemic stroke in its role of preventing the free movement of …

The Role Of Cd8 T Cell Immunodominance And Regulatory T Cells In Neonatal Immunity To Influenza Virus, Luke Heil

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Neonates are more susceptible to influenza virus infection than adults, resulting in increased morbidity and mortality as well as delayed clearance of the virus. Efforts to improve influenza infection outcomes in neonates typically center on prevention, although current vaccines fall short of complete protection and can only be administered in humans after 6 months of life. We propose that as the neonatal immune system responds differently than the adult immune system, interventions that are efficacious or tolerable in adults cannot be guaranteed to perform the same in neonates. T cell vaccines that target conserved influenza virus epitopes have been proposed …

Neuroprotective Strategies Following Experimental Traumatic Brain Injury: Lipid Peroxidation-Derived Aldehyde Scavenging And Inhibition Of Mitochondrial Permeability Transition, Jacqueline Renee Kulbe

Theses and Dissertations--Neuroscience

Traumatic brain injury (TBI) represents a significant health crisis. To date there are no FDA-approved pharmacotherapies available to prevent the neurologic deficits caused by TBI. Following TBI, dysfunctional mitochondria generate reactive oxygen and nitrogen species, initiating lipid peroxidation (LP) and the formation of LP-derived neurotoxic aldehydes, which bind mitochondrial proteins, exacerbating dysfunction and opening of the mitochondrial permeability pore (mPTP), resulting in extrusion of mitochondrial sequestered calcium into the cytosol, and initiating a downstream cascade of calpain activation, spectrin degradation, neurodegeneration and neurologic impairment.

As central mediators of the TBI secondary injury cascade, mitochondria and LP-derived neurotoxic aldehydes make promising …

Tgf-Β, Wnt, And Fgf Signaling Pathways During Axolotl Tail Regeneration And Forelimb Bud Development, Qingchao Qiu

Theses and Dissertations--Neuroscience

Tgf-β, Wnt, and Fgf signaling pathways are required for many developmental processes. Here, I investigated the requirement of these signaling pathways during tail regeneration and limb development in the Mexican axolotl (Ambystoma mexicanum).

Using small chemical inhibitors during tail regeneration, I found that the Tgf-β signaling pathway was required from 0-24 and 48-72 hours post tail amputation (hpa), the Wnt signaling pathway was required from 0-120 hpa, and the Fgf signaling pathway was required from 0-12hpa. Tgf-β1 was upregulated after amputation and thus may mediate Tgf-β signaling pathway during tail regeneration. Both Smad-mediated and non-Smad mediated Tgf-β signaling …

Autologous Peripheral Nerve Grafts To The Brain For The Treatment Of Parkinson's Disease, Andrew Welleford

Theses and Dissertations--Neuroscience

Parkinson’s disease (PD) is a disorder of the nervous system that causes problems with movement (motor symptoms) as well as other problems such as mood disorders, cognitive changes, sleep disorders, constipation, pain, and other non-motor symptoms. The severity of PD symptoms worsens over time as the disease progresses, and while there are treatments for the motor and some non-motor symptoms there is no known cure for PD. Thus there is a high demand for therapies to slow the progressive neurodegeneration observed in PD. Two clinical trials at the University of Kentucky College of Medicine (NCT02369003, NCT01833364) are currently underway that …

Essays On Price Discrimination And Demand Learning, Benjamin E. Wallace

Theses and Dissertations--Economics

This dissertation consists of three essays examining how and why firms set prices in markets. In particular, this dissertation shows how firms may utilize nonlinear pricing to price discriminate, how firms may experiment with the prices they set to learn about the demand function in the market they serve in later periods and the effects of these pricing strategies on consumer welfare.

In Essay 1, I show how firms in the milk market use nonlinear price schedules -- quantity discounts -- to price discriminate and increase profits. I find that firms have a greater ability to price discriminate on their …

Depressive Symptoms Among Farm Women Aged 50 And Older, Cheryl Dean Witt

Theses and Dissertations--Nursing

Alarming rates of suicide among production farmers have prompted researchers to investigate factors associated with depressive symptoms among this population. Aspects of farm life and farming can contribute to higher levels of depressive symptoms. Higher levels of depression can also increase an individual’s risk of injury and development of chronic disease, impacting overall quality of life. Despite the approximate 3.5 million farm women in the U.S., current research has focused on the male farmer.

Men and women have different responses to stressors, and women in general have a higher prevalence of depressive symptoms. Farm women can be further subjected to …

Neurochemical Factors Associated With The Initial Pathophysiological Reaction To Large Vessel Occlusion Stroke, Sarah R. Martha

Theses and Dissertations--Nursing

Ischemic stroke is the leading cause of disability world-wide and affects over 800,000 people per year in the United States. The majority of these strokes are ischemic due to a blockage of blood flow to the brain. Damage to the brain occurs at the onset of stroke, neuronal cell death is irreversible and therefore, quick treatment to remove blockage is critical factor in the recovery from stroke. Mechanical thrombectomy as a treatment for ischemic stroke provides an ideal opportunity to collect blood distal and proximal to the cerebral thrombus to examine neurochemical changes occurring during stroke.

The purpose of this …