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The Effect Of Ph On Synaptic Transmission At The Neuromuscular Junction In Drosophila Melanogaster, Catherine Elizabeth Stanley

Theses and Dissertations--Biology

Synaptic transmission is the main avenue of neuronal communication and can be affected by a multitude of factors, both intracellularly and extracellularly. The effects of pH changes on synaptic transmission have been studied for many years across many different models. Intracellular acidification at the presynaptic terminal is known to occur with increased neuronal activity and can also occur in pathological conditions. The effects of these pH alterations are therefore an important area of study. Here, intracellular acidification using either propionic acid or the ammonium chloride pre-pulse technique was examined for the effects on both spontaneous and evoked synaptic transmission at …

From Organisms To Ecosystems: Impacts Of Limb Loss And Regeneration On Crayfish Behavior, Luc Arnaud Dunoyer

Theses and Dissertations--Biology

The ability of some organisms to regenerate tissues and organs has fascinated naturalists since antiquity, dating back to the earliest accounts of scientific inquiry with Aristotle in Ancient Greece. Then, Darwin’s theory invigorated some scientists’ dream of stimulating (or reactivating) regenerative capacities in human beings by showing that we are related to highly regenerative organisms. More recently, a renewed interest in discovering the molecular and genetic basis for organ and tissue regeneration has led biologists to focus more specifically on a restrictive set of model organisms.

Although the process of limb regeneration is different between invertebrate and vertebrate organisms, it …

From Genes To Species: Ecological Speciation With Gene Flow In Neodiprion Pinetum And N. Lecontei, Emily E. Bendall

Theses and Dissertations--Biology

My dissertation focuses on how differences accumulate across the genome during ecological speciation with geneflow. To do this I used two species of Neodiprionpine sawflies, which are plant-feeding hymenopterans with high host specificity. I used experimental crosses to measure both intrinsic and extrinsic postzygotic isolation and to understand the contribution of specific traits to reproductive isolation. Despite substantial genetic divergence and haploid males in which all recessive incompatibilities should be expressed, I found surprisingly little evidence of intrinsic postzygotic isolation. Recombination in hybrid males may reconstitute viable genotypes and counteract the effects of haploidy in males. Nevertheless, hybrids have …

Elucidating The Role Of Light-Induced Circadian Disruption On Atherosclerosis In Apolipoproteine-Deficient Mice, Jeffrey Chalfant

Theses and Dissertations--Biology

Circadian rhythms are approximately 24-hour oscillations of nearly every biological process in the body. The circadian system coordinates these rhythms of physiology and behavior with environmental cycles such as the light-dark cycle. Shift workers, who experience irregular exposure to the light-dark cycle, have chronically disrupted circadian rhythms and increased risk of developing cardiovascular disease, but the mechanisms are unknown. Our studies investigated the effects of light-induced circadian disruption on atherosclerosis in ApolipoproteinE-deficient (ApoE^-/-) mice. We found that male ApoE^-/- mice housed in constant light for 12 weeks, which results in severe disruption of circadian rhythms …

The Roles Of Polar Cell Extensions In Drosophila Micropyle Formation, Bradford Hull

Theses and Dissertations--Biology

The Drosophila micropyle is a conserved formation utilized to allow sperm passage past the robust eggshell structure for fertilization. Micropyle formation follows a unique acellular tubulogenesis method where it is secreted and shaped by specialized follicle cells including the border cells and polar cells. In late oogenesis, the polar cells form extensions that are necessary to create the micropyle pore through which sperm enters. Previous work established that polar cell extension presence is required for micropyle pore formation. We investigated temporal requirements of extensions throughout chorion deposition and found extensions are required during the beginning and middle of choriogenesis, but …

Arthropod Resistant Tomatoes: Screening Tools, Yield And Nutritional Quality Of Interspecific Hybrids, Mohammad Hasan Salman Ali Dawood

Theses and Dissertations--Plant and Soil Sciences

Tomato (Solanum lycopersicum) is one of the most economically important vegetable crops grown around globe but is a host for numerous pests and pathogens. In the future, tomato breeders will have to focus on increasing fruit quantity and on enhancing pest resistance. Many accessions of the wild relative of tomato, S. habrochaites display high levels of resistance towards arthropods such as spider mites. The presence of the sesquiterpene hydrocarbon, 7-epi-zingiberene, found in S. habrochaites type IV trichomes has been associated with arthropod resistance. However, the presence of other compounds in its trichome secretions may also be related …

Evaluation Of The Influence Of Dicamba Exposure On Crop Injury And Canopy Closure Of Glufosinate Resistant Soybean, Zachary K. Perry

Theses and Dissertations--Plant and Soil Sciences

Dicamba-resistant soybean along with lower volatility dicamba formulations have been introduced in an attempt to control herbicide resistant weeds such as Amaranthus palmeri. This introduction has increased the amount of dicamba being applied later in the growing season increasing the prevalence of dicamba off-target movement. Dicamba damage was simulated by applying low rates of dicamba directly on soybeans at rates (0.5 g ae ha^-1, 1 g ae ha^-1 and 5 g ae ha^-1 dicamba) and five-exposure timings from June 1 to July 10. The experimental design was a randomized complete block with four replications at …

Soil Carbon Dynamics And Greenhouse Gas Emissions In Conservation Tillage Systems At Multiple Scales, Yawen Huang

Theses and Dissertations--Plant and Soil Sciences

Conservation tillage practices like no-tillage and reduced tillage have been widely implemented worldwide, with expectations they would provide multiple benefits (e.g., yield enhancement and soil carbon sequestration) for food security and climate adaptation and mitigation. However, the adoption of conservation tillage faces both opportunities and challenges. A knowledge gap still exists regarding the effects of conservation tillage on the carbon cycle in agroecosystems. This dissertation reflects a comprehensive evaluation of conservation tillage at multiple scales using an integrated systems approach, a combination of data synthesis, the agriculture ecosystem model, and field observations and measurements. I first conducted a meta-analysis to …

End-To-End Prediction Of Weld Penetration In Real Time Based On Deep Learning, Wenhua Jiao

Theses and Dissertations--Electrical and Computer Engineering

Welding is an important joining technique that has been automated/robotized. In automated/robotic welding applications, however, the parameters are preset and are not adaptively adjusted to overcome unpredicted disturbances, which cause these applications to not be able to meet the standards from welding/manufacturing industry in terms of quality, efficiency, and individuality. Combining information sensing and processing with traditional welding techniques is a significant step toward revolutionizing the welding industry. In practical welding, the weld penetration as measured by the back-side bead width is a critical factor when determining the integrity of the weld produced. However, the back-side bead width is difficult …

Neonatal Abstinence Syndrome: Effectiveness Of Targeted Umbilical Cord Drug Screening In Determining Risk Of Withdrawal, Alecia Karr

DNP Projects

Neonatal Abstinence Syndrome (NAS) is a condition in which an infant experiences withdrawal from uterine exposure to various substances such as caffeine, nicotine, amphetamines, THC, opioids, benzodiazepines, and other types of substances. Depending on the severity of the symptoms, these infants may experience a longer hospital stay and may need treatment and monitoring in the neonatal intensive care unit (NICU), resulting in an increase in healthcare costs. The objective of this project was to determine if targeted drug screening of newborns was effective in determining infants at risk of NAS based on a positive screening result. This study utilized a …

Evaluating Colorectal Cancer Screening Rates In An Urban Primary Care Practice, Kristen Makowski

DNP Projects

Colorectal cancer accounts for 8% of all cancer deaths and can be prevented through timely removal of colon polyps. Despite recommendations for routine screening, approximately 31.2% of patients go unscreened for this disease (Centers for Disease Control and Prevention, 2018). The purpose of this project was to determine screening rates and documentation mechanisms for colorectal cancer in an urban primary care practice, to determine how many patients completed the screening, and to present findings to the practice providers along with exploring ways to increase screenings. An additional purpose of this project was to determine and identify patient demographics which can …

Effectiveness Of A School-Based Asthma Education Program For 8-10-Year-Old Children, Laura Hunt

DNP Projects

Background: Asthma is the most common chronic condition to affect children in the United States Five million children throughout the United States and approximately 112, 000 children in Kentucky are living with the diagnosis of asthma (CDC, 2017; CHFS, 2017). Based on current rates 1 out of 10 elementary school-age students will likely have asthma (CDC, 2019). Educating elementary-age students about asthma and symptoms of an asthma exacerbation is very important and could save a life.

Methods: A school-based asthma education program targeting children in third and fourth grades was implemented at two elementary schools in Central Kentucky. The asthma …

Cover Crops And Cover Crop Mixes: Stratification Of Biological Effects, Landon M. Gibbs

Theses and Dissertations--Plant and Soil Sciences

The potential nutrient cycling benefits from legumes (e.g. N₂-fixation) and the high biomass potential of cereal rye are well known. Further studies are warranted to evaluate bi-culture mixtures and their effects on soil nutrient stratification and microbial enzyme activity because these two properties may be differently expressed (enhanced) by legume/grass mixes. The objectives of this study were: (1) show different cover crops and cover crop mixes containing grasses and legumes differentially stratify carbon and N; (2) show the change in microbial enzyme activity in soils planted with individual cover crops relative to cover crop mixes; 3) determine the …

Nickel Speciation, Microbial Community Structure, And Chemical Attributes In The Rhizosphere Of Nickel Hyperaccumulating And Non-Accumulating Plants Growing In Serpentine Soils, James W. Morris

Theses and Dissertations--Plant and Soil Sciences

Serpentine soils are formed from weathering of serpentinite, the ultramafic parent material that provides serpentine soils with their unique identity. Weathering of serpentinite results in a plethora of edaphic factors that impose strong selection pressures on plant life, with high magnesium (Mg) to calcium (Ca) ratio, low fertility, and high levels of geologically derived metals such as cobalt (Co), chromium (Cr), and nickel (Ni). Appropriately, plant life on serpentine soils is often specialized, sparse, and endemic which in turn affects the ecosystems that develop on serpentine soils from the landscape scale down to the physiology of their inhabitants. At the …

Using Biology To Better Inform Marestail [Conyza Canadensis (L.) Cronq.] Management, Ryan James Collins

Theses and Dissertations--Plant and Soil Sciences

The importance of sustainable weed management practices continues to grow as farmers are increasingly faced with herbicide resistant weed populations. Marestail (Conyza canadensis), also known as horseweed, is a problematic weed in soybean cropping systems that has developed resistance to multiple herbicide modes of action. A two year study was conducted in Lexington, KY, examining timing patterns of marestail emergence and different integrated weed management strategies for marestail prior to no-till soybean. Treatments contained fall and spring applied herbicides with different levels of residual activities, cover crops and combinations of the two. Additionally, yields and partial budget net …

In Pursuit Of Understanding Barrel Variation: Surveying The Lignocellulose Composition And Content Changes In Quercus Alba Barrel Staves During Cooperage And Bourbon Whiskey Maturation, Jarrad Wade Gollihue

Theses and Dissertations--Plant and Soil Sciences

Bourbon whiskey is a distilled spirit which is a uniquely American with several legal requirements including 1) the major grain in the mash is corn, 2) must be aged in a new charred white oak barrel, and 3) made in the United States of America. Kentucky is the whiskey historical home, producing most of the bourbon in the United States. Interest in whiskey has developed a need to understand more about the underlying chemistry of bourbon. The charred white oak barrel used in bourbon production is of substantial interest because the barrel has been implicated in giving American whiskey its …

The Balancing Act Of Cytokinin In Environmental Stress Tolerance, Sumudu Sandeepani Karunadasa

Theses and Dissertations--Plant and Soil Sciences

Cytokinin, long known as a phytohormone that regulates plant growth and development, has been recently recognized as an important regulator of stress responses. However, our current knowledge about the mechanisms by which cytokinin regulates stress responses is fragmentary, as many of the studies in this field yielded conflicting results. Most of the work described here has focused on analyses of the molecular mechanisms of cytokinin-dependent regulation of growth and development under stress conditions, with an emphasis on the role of cytokinin-dependent regulation of protein synthesis in development and stress tolerance.

One of the important contributions of this study is the …

A Biophysical Investigation Of Stability, Ligand Binding, And Iron State Of Cyp102a1, Catherine A. Denning-Jannace

Theses and Dissertations--Chemistry

Cytochrome P450s (CYPs) are cysteine ligated Fe-heme monooxygenases that are found in all domains of life. In mammals, they have a role in xenobiotic metabolism and steroid synthesis, making them a fundamental requirement for survival. In addition, their ability to perform a variety of chemical reactions on an array of substrates makes CYPs highly sought for biotechnical applications such as wastewater remediation, production of potential drug candidates, and creation of drug metabolites. By mutating specific amino acids, these enzymes can be engineered to change their substrate binding profiles and achieve stereo- and regio-specific chemistry. While these mutations are essential to …

New Single Molecule In Vivo And Ex Vivo Methods To Understand The Physiological Effects Of Nicotine Use, Xu Fu

Theses and Dissertations--Chemistry

The consumption of tobacco products leads to several health risks, including respiratory diseases, cardiovascular diseases, and many different cancers. Nicotine, the primary addictive compound in tobacco, acts on the cholinergic system through nicotinic acetylcholine receptors (nAChRs), which is believed to be an essential component of addiction. However, the lack of a complete understanding of the neurobiological mechanisms of nicotine abuse is one of the primary barriers to finding potent therapeutics for smoking cessation. Single-molecule imaging is an ideal tool to study molecular mechanisms of protein and physiological changes both in vitro and in vivo. In this dissertation, our research …

Laser Ablation In Liquid For The Controlled Production Of Photoluminescent Graphene Quantum Dots And Upconverting Nanoparticles, Rosemary Lynn Calabro

Theses and Dissertations--Chemistry

Photoluminescent­ (PL) nanomaterials play an important role in areas including displays, sensing, solar, photocatalysis, and bio applications. Traditional methods to prepare PL materials suffer many drawbacks such as harsh chemical precursors, complicated synthetic steps, and production of many byproducts. Laser ablation in liquid (LAL) has emerged as a promising alternative to prepare materials that is single-step, fast, uses fewer precursors, produces fewer side products, and has simple purification steps. During LAL, a solid target is irradiated with a pulsed laser source. The laser pulses cause plasma plumes of the target material to form which are cooled, condensed, and can react …

Deconvolution Tools For Extracting Insight From Challenging Two-Flavin Systems, Dallas Michael Bell

Theses and Dissertations--Chemistry

Flavoproteins have long been explored for their ubiquity among a number of metabolic and energetic reactions. The flavin cofactor has the inherent benefit of distinct spectral changes associated with redox transitions; however, the double-edged sword is incurred as these distinct signatures overlap and take up much of the UV-vis spectral range. Therefore, it is crucial to create a method to demarcate the expressed redox transitions for studying these systems. The first portion of these studies discusses the creation of a program that deduces spectra for redox transitions in a single-flavin containing model protein: flavodoxin. The latter portions discuss the application …

Structure, Surface, And Interfacial Modifications Of Carbon And Supported-Metal Electrodes For Electrochemical Carbon Dioxide Conversion, Namal Wanninayake

Theses and Dissertations--Chemistry

Currently, the global emission of greenhouse CO₂ is over 36 billion tons per year. Consequently, the atmosphere's CO₂ concentrations have exceeded 400 ppm, which is the highest reported in the last three million years. The accumulation of CO₂ is the most critical origin for today's climate change; thus, closing the carbon cycle is vital to reverse the detrimental impacts of climate change. Under this goal, the electrochemical reduction of CO₂ into commodity fuels and chemicals via renewable energy is one of the most promising strategies to recycle CO₂. Despite significant progress made in electrocatalysis, …

Characterization And Electrochemical Performance Of Dopamine-Sensitized Titania Thin Films, Joshua Garay

Theses and Dissertations--Chemical and Materials Engineering

Sensitization of mesoporous titania films with dopamine and polydopamine for visible light photoelectrochemical activity is investigated. Sensitization effectiveness is compared with 8 mM dopamine solutions of varying pH (acidic, basic, and neutral), as well as with a basic polydopamine solution. Vibrational changes due to dopamine attachment are determined from detached powders by Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) is used to quantify organics attached. X-ray photoelectron spectroscopy (XPS) of intact films probes the chemically induced charge shift from dopamine attachment. Cyclic voltammetry identifies the irreversible dopamine oxidation and tin reduction voltages. Finally, chronoamperometric curves are used to compare …

Effect Of Silica Nanoconfinement Of Lipid Bilayers On Its Phase Transition And On The Colloidal Stability Of Silica Nanoparticles, Aniruddha Atul Shirodkar

Theses and Dissertations--Chemical and Materials Engineering

In this work, we incorporated 4-(N-Boc-aminometyl) phenylboronic acid (BA), at different concentrations, into 1,2-dipalmitoyl-sn-glycero-3- phosphocholine (DPPC) bilayers confined within nanopores of two different mean pore diameters of 7.4 nm and 11.7 nm of micron sized silica particles. The confinement of DPPC into nanopores resulted in the depression in the main phase transition temperatures compared to the liposomal system. The addition of BA was found to induce disruptions in the acyl chains of the lipid molecules at all concentrations of the solute. The lipid bilayer cooperativity was found to be higher in the confined systems compared to the liposomal systems despite …

Nanostructured Metal Thin Films As Components Of Composite Membranes For Separations And Catalysis, Michael J. Detisch

Theses and Dissertations--Chemical and Materials Engineering

Novel metallic thin film composite membranes are synthesized and evaluated in this work for improved separations and catalysis capabilities. Advances in technology that allow for improved membrane performance in solvent separations are desirable for low molecular weight organic separation applications such as those in pharmaceutical industries. Additionally, the introduction of catalytic materials into membrane systems allow for optimization of complex processes in a single step. By adding a nanostructured metallic thin film to its surface, a polymer membrane may be modified to exhibit these improved properties. Using magnetron sputtering, thin metal films may be deposited on commercially available membranes to …

A Framework For Heterologous Biosynthesis Of Natural Products In Mammalian Cells Via Polymer-Mediated Transfections, Logan Warriner

Theses and Dissertations--Chemical and Materials Engineering

With the promise to treat a multi-faceted list of serious inherited and acquired diseases, such as cancer, neurodegenerative and infectious diseases, and inherited genetic indications, gene therapy has continued to push the boundaries of traditional medicine since its earliest implementation. While much progress has been made, clinical success has largely remained elusive. Immunogenicity, difficulty producing commercially relevant quantities, and having a limited genetic payload still limits the ability of viruses to act as directed delivery agents for genetic material. As such, researchers have turned to cationic synthetic materials as a means of delivering nucleic acids, which can circumvent the immune …

The Development Of Temperature And Ph Responsive Hydrogels And Membranes For Selective Sorption Of Perfluoroorganics And Nanoparticle Integrated Catalytic Degradation Of Pcb, Anthony Saad

Theses and Dissertations--Chemical and Materials Engineering

The functionalization and use of responsive and catalytic polymeric membranes and materials were explored for contaminant capture and degradation. While membranes have a wide variety of uses across multiple industries, the inclusion of materials that are temperature and pH responsive in the membrane pore domain yields a wide range of applications and possibilities for water treatment. Temperature and pH responsive polymers, as well as controlled nanostructured materials, were synthesized in membrane pores for advanced adsorption-desorption and catalytic treatment of emerging organic contaminants in water. In this study, supported by the NIEHS, poly-N-isopropylacrylamide (PNIPAm) was used as a model thermo-responsive polymer, …

Understanding And Mitigating The Electrochemical-Mechanical Degradation Of High Capacity Battery Electrodes, Dingying Dang

Theses and Dissertations--Chemical and Materials Engineering

Lithium-ion batteries (LIBs) with high energy density and cycling stability play a critical role in developing electric vehicle (EV) and grid energy storage techniques. The electrochemical performance of LIBs can be improved by using high capacity positive (e.g., LiNi_1/3Mn_1/3Co_1/3O₂, i.e., NMC111) and negative (e.g., silicon) electrodes; both, however, experience severe electrochemical-mechanical degradation caused by the lithiation/delithiation induced volume changes. Understanding mechanical degradation mechanisms and their relationships with the capacity fading of electrodes is important for improving the cycling stability of electrodes as well as optimizing the design of electrodes with high capacity …

Heart Tissue Reconstruction By Light-Controlled Cell Adhesion, Patterning And Alignment On Decellularized Scaffolds, Cong Li

Theses and Dissertations--Chemical and Materials Engineering

There is an urgent demand for engineered tissues and organs because of extremely limited donor tissues available for transplant. The challenge of tissue rejection has motivated many researchers to try to remove all of the cells from a heart and then add back in patient matched cells. These recellularized hearts are a promising avenue towards a functional bioartifical heart that is less likely to be rejected. Decellularized extracellular matrix (ECM) scaffolds generated from animal hearts do not have the cellular components that elicit immune rejection in patient, and they also preserve the native heart tissue structure. While decellularization techniques are …

Polymeric Nanocomposite Membranes With Phosphorene Based Pore Fillers For Fouling Control, Joyner Eke

Theses and Dissertations--Chemical and Materials Engineering

Phosphorene is a two-dimensional material exfoliated from bulk phosphorus. Specifically, relevant to the field of membrane science, the band gap of phosphorene provides it with potential photocatalytic properties, which could be explored in making reactive membranes able to control the accumulation of compounds on the surface during filtration, or fouling. Another reason phosphorene is a promising candidate as a membrane material additive is due to its catalytic properties which can potentially destroy foulants on the membrane surface.

The first goal of this study was to develop an innovative and robust membrane able to control and reverse fouling with minimal changes …