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Involvement Of The Renin Angiotensin System In Marfan Syndrome Associated Thoracic Aortic Aneurysms, Jeff Zheying Chen

Theses and Dissertations--Physiology

Thoracic aortic aneurysms (TAAs) are clinically-silent dilations of the aorta which greatly increase the risk of aortic rupture, a condition with 50-90% mortality. Marfan syndrome (MFS) is caused by mutations in fibrillin-1 (FBN1) and is associated with TAAs. Due to an absence of validated and effective pharmacologic therapies to prevent or reverse TAA, most MFS patients require surgical aortic repair. Understanding MFS associated TAA pathogenesis would direct development of new pharmacologic therapies. Previous research has implicated the renin angiotensin system in TAA. In both males and females, angiotensinogen (AGT) is cleaved serially to generate the main effector peptide angiotensin II …

Ceramide-Enriched Extracellular Vesicles: A Role In Enhancing Amyloid-Beta Neurotoxicity And Mitochondrial Damage In Alzheimer’S Disease, Ahmed Elsherbini

Theses and Dissertations--Physiology

Alzheimer’s disease (AD) is an age-dependent, progressive, neurodegenerative disorder that is characterized clinically by the impairment of cognitive functions concomitant with behavioral and personality changes. AD is associated with distinct pathological hallmarks, namely, intracellular neurofibrillary tangles comprised of hyperphosphorylated tau protein, extracellular amyloid beta (Aβ) plaques, and marked brain atrophy. Besides their main role as the core component of amyloid plaques, oligomeric Aβ have been shown to be neurotoxic. The exact mechanism of Aβ neurotoxicity is yet to be elucidated.

Recently, a pathogenic function of small extracellular vesicles- also known as exosomes- has been proposed, suggesting that exosomes can transfer …

Characterizing The Roles Of Pipecolic Acid And Reactive Oxygen Species Metabolic Enzymes In Plant Systemic Immunity, Ruiying Liu

Theses and Dissertations--Plant Pathology

Systemic acquired resistance (SAR), initiated by a plant upon recognition of microbial effectors, involves the generation of mobile signals at the primary infection site, which translocate to and activate defense responses in distal tissues. Among the signals contributing to SAR include salicylic acid (SA), nitric oxide (NO), reactive oxygen species (ROS), glycerol-3-phosphate (G3P), and pipecolic acid (Pip). Our previous studies show there are two branches of SAR signaling pathways in Arabidopsis: one regulated by NO/ROS-G3P and the other by SA. Both NO/ROS-G3P and SA-mediated signaling branches function in parallel during SAR. To better understand the role of Pip in SAR …

Pathogenicity, Toxigenic Potential, And Genomics Of Fusarium Graminearum And F. Meridionale Causing Ear And Stalk Rot Of Maize, Franklin Jackson Machado

Theses and Dissertations--Plant Pathology

Gibberella ear (GER) and stalk rot (GSR) diseases of maize in Brazil are caused mainly by Fusarium meridionale, a species belonging to the Fusarium graminearum species complex (FGSC). Another species within this complex, F. graminearum sensu stricto (hereafter F. graminearum), is second in importance on maize, but is the most common species found causing Fusarium Head Blight disease of wheat in Brazil. The latter species is the predominant cause of GER and GSR in North America, where F. meridionale has not been found thus far. In this dissertation I undertook a comparative analysis of pathogenic, saprophytic, toxigenic and …

Evaluation Of Rhodococcus Equi Susceptibility To Silver Nanoparticle Antimicrobials, Elizabeth Boudaher

Theses and Dissertations--Veterinary Science

Rhodococcus equi is a significant cause of pneumonia in foals and immunocompromised humans. Antimicrobial resistance among R. equi isolates has developed as a consequence of inappropriate stewardship and bacterial evolution, leading to an increased rate of treatment failures that typically result in foal fatality. In the current study, we evaluated the efficacy of antimicrobial silver nanoparticle (AgNP) complexes in controlling R. equi growth. Previous studies characterizing AgNP-induced antibacterial effects in other Gram-positive pathogens led us to hypothesize that silver nanoparticle antimicrobials impact R. equi viability and intracellular replication. We therefore investigated the effect of silver nanoparticle complexes on R. equi …

Donor Age Effects On The Proliferative And Chondrogenic/Osteogenic Differentiation Performance Of Equine Bone Marrow- And Adipose Tissue Derived Mesenchymal Stem Cells In Culture, Jasmin Bagge

Theses and Dissertations--Veterinary Science

Orthopedic injuries are a major cause of lameness and morbidity in horses. Bone marrow (BM)- and adipose tissue (AT) derived mesenchymal stem cells (MSCs) have shown potential to facilitate the repair of orthopedic injuries and are being used increasingly in veterinary clinics. Presently, the use of MSCs as a therapy for equine patients is most commonly applied as autologous transplants, using BM- and AT-MSCs harvested from the patient shortly after the time of injury. Cell-based therapies are therefore delayed to enable primary cell numbers to be expanded in culture. Of concern, however, are human and rodent studies that have shown …

Diet Of A Recently Reintroduced River Otter (Lontra Canadensis) Population In Taos County, New Mexico, Gabriela Alexandra Wolf-Gonzalez

Theses and Dissertations--Forestry and Natural Resources

North American river otters (Lontra canadensis), native to every U.S. state and Canada, experienced extensive population decreases and range reduction until the mid-20th century as a result of overexploitation and habitat loss during European colonization. The last known river otter in New Mexico was killed on the Gila River in 1953, although unverified reports continued thru 2008. After a nearly 60-year absence from New Mexico, 33 adult river otters were reintroduced to the Rio Pueblo de Taos in the northern part of the state between 2008-2010; however, they were not subsequently monitored or studied. I characterized diet of …

Food Abundance Modulates Juvenile Mussel (Unionidae) Growth Responses To The Asian Clam (Corbicula Fluminea), Drew Edward Jerry White

Theses and Dissertations--Forestry and Natural Resources

Interactions between the Asian Clam (Corbicula fluminea) and freshwater mussels (Unionidae) have been documented, but the effect of food abundance on these interactions is not well understood. I examined the role of food abundance in modulating the growth and survival responses of juvenile Cumberland Bean (Venustaconcha troostensis) to Corbicula. I ran a series of controlled experiments in which I tested the effect of Corbicula on growth and survival of juvenile freshwater mussels in multiple environmentally relevant conditions of food abundance. Corbicula had no effect on juvenile mussel survival, regardless of food abundance. However, juvenile mussel …

Comparative Chondrogenesis Of Interzone And Anlagen Cells In Equine Skeletal Development, Chanhee Mok

Theses and Dissertations--Veterinary Science

At the presumptive sites of future synovial joints during mammalian skeletogenesis, articular cartilage develops from interzone located between the cartilaginous anlagen of bones. Thus, two types of cartilaginous tissues differentiate in close proximity. While anlagen cartilage is transient, progressing through endochondral ossification to form bones, articular cartilage is stable and functions throughout life to facilitate both low friction movement and load distribution. Despite important life-long functional properties, articular cartilage has a very limited intrinsic ability to repair structural defects. On the other hand, structural lesions in bones generally heal well by forming a cartilaginous callus and recapitulating endochondral ossification to …

Long-Term Effects Of Crop-Tree Release On The Growth And Quality Of Upland White Oak Stands, Philip Jay Vogel

Theses and Dissertations--Forestry and Natural Resources

The alteration of historical disturbance regimes, forest parcelization, and varying goals among landowners all present challenges to oak management in the eastern U.S. Foresters and landowners need tools to promote oak sustainability that are applicable on small forestland holdings and within complex management plans. From this perspective, this research evaluates a crop-tree release study installed in southeastern Kentucky in 1983. The experiment includes four, 2-acre replications of three treatment levels: 20 crop-trees per acre, 34 crop-trees per acre, and a control treatment in which crop-trees were selected but not released. Half-acre measurement plots were installed at the outset of the …

Effects Of Thinning Regimes On Genetic Variation Of White Oak (Quercus Alba L.) In Upland Oak Forests Of Eastern Kentucky, Rachel Gayle Thunder

Theses and Dissertations--Forestry and Natural Resources

This research assesses the effects of silvicultural thinnings, varying in residual basal area and number of thinnings, on genetic diversity and relatedness of white oak (Quercus alba L.). The objectives were to (1) develop microsatellite DNA markers (simple sequence repeats, SSRs) for assessing the genetic diversity of white oak and (2) determine if thinnings significantly change the degree of diversity and relatedness in white oak stands. For objective 1, 84 primer pairs from previously predicted genomic SSRs of white oak were evaluated for consistent PCR amplification and polymorphism. Twenty of the 84 primer pairs amplified consistently and were confirmed …

Evaluation Of Created Wetlands As Amphibian Habitat On A Reforested Surface Mine, Michaela M. Lambert

Theses and Dissertations--Forestry and Natural Resources

Reclaimed mines often lack pre-mining habitat due to soil compaction and lack of natural features. If soils are de-compacted and natural features restored, new habitats can be created, such as wetlands for amphibians. It is important to understand which factors affect amphibian use of wetlands to estimate the efficacy of created wetlands as habitat. I sampled 40 wetlands among 4 ages (2, 4, 6, and 8 years) on a reforested surface mine to: 1) characterize differences in wetland habitat across age classes, 2) estimate amphibian occupancy, 3) investigate estimated abundance of 4 amphibian species (Lithobates sylvaticus, L. clamitans, Notophthalmus …

Assessing The Climate Water Balance Model’S Ability To Predict Soil Moisture Variability And Species Distribution Of A Forested Watershed In The Northern Cumberland Plateau, Katherine J. Love

Theses and Dissertations--Forestry and Natural Resources

Spatial patterns of moisture and tree species have been studied using environmental gradients, often represented by terrain attributes in GIS. With climate change, GIS terrain variables, which are static as long as the elevation remains unchanged, will not reflect alterations in temperature, water cycle, and atmospheric conditions. In this thesis, the commonly used terrain variables and climate water balance variables were evaluated and compared for their ability to explain soil moisture and tree species distributions in a forested watershed in the Northern Cumberland Plateau. The results suggest that GIS terrain variables generally perform better than climate water balance variables, however, …

Effects Of Shelterwood And Patch Cut Harvests On A Post White-Nose Syndrome Bat Community In The Cumberland Plateau In Eastern Kentucky, Phillip Lee Arant

Theses and Dissertations--Forestry and Natural Resources

The impact of shelterwood and patch cuts harvests on bat communities was tested at three sites in Eastern Kentucky. Shelterwood harvests had 50% of the basal area and understory removed to create a uniform spacing of residual trees. Patch cuts had 1-hectare circular openings created to remove 50% of the basal area creating an aggregated spacing of residual trees. Acoustic detectors were deployed to assess activity levels pre-harvest. Sites were then sampled from 1 – 2 years post-harvest to determine differences. Pre-harvest data revealed little acoustic activity for the Myotis spp. at two sites. The remaining site had high activity …

Enhancing Native Plant Diversity On Legacy Minelands, Anna Maria Branduzzi

Theses and Dissertations--Forestry and Natural Resources

Surface mining for coal has left scars on landscapes and reduced ecosystem functions across Appalachia for over a century. In the Monongahela National Forest, WV, a restoration project has been going on since 2009 on legacy minelands that dissect the biodiverse high elevation red spruce ecosystem. Goals of the restoration project include watershed improvement, soil building, enhancement of early successional habitat, and reforestation. Decompaction of the minelands is a critical step in the restoration process, and allows native vegetation to begin colonizing the site. Through this project, hundreds of vernal pools are constructed each year, and woody debris from non-native …

Ecosystem Of Bagged Grain Stored Under Naturally Ventilated Warehouse: Analysis And Modelling, Michael Ayodele Omodara

Theses and Dissertations--Biosystems and Agricultural Engineering

Grain in Africa and indeed most developing parts of the world are stored in polypropylene or jute bags arranged in stacks of varied dimensions in naturally ventilated warehouses. This practice is, however, associated with high postharvest losses due to poor temperature and moisture management during storage. This constitutes a major economic and food security challenge in these countries. Therefore, this study characterizes changes in moisture content and temperature occurring in a stack of bagged corn by determining the permeability of bag materials that influence moisture transfer and developing a mathematical model of heat and mass transfer which incorporates the unique …

Characterizing And Predicting The Antimicrobial Properties Of Lignin Derivatives, Ryan Kalinoski

Theses and Dissertations--Biosystems and Agricultural Engineering

Due to the overuse of antibiotics in our society, there has been a steady rise in highly antimicrobial-resistant bacteria in the last decade. This has created a renewed interest in natural phenolic compounds for antimicrobial discovery amongst the scientific community. To this end, lignin is the most abundant naturally occurring phenolic polymer on earth and has already been known to have antimicrobial properties due to its polyphenolic structure. In addition, lignin is considered a major waste product for lignocellulosic biorefineries, and its valorization into value-added products will generate extra profit for a biorefinery, making biofuels less expensive, increasing their marketability …

Physicochemical Characterization, Structural Determination, And Molecular Dynamic Modeling Of Proso Millet Proteins For Enhanced Food Functionality, Felix Akharume

Theses and Dissertations--Biosystems and Agricultural Engineering

More than one-third of Americans today incorporate plant-based protein into their diet and about 40% believed that plant-based protein is healthier than animal protein, especially Millennials. The increasing global demand for plant-based proteins driven by the high cost of animal proteins, consumers’ desire for lean protein, vegetarianism, and the need for more sustainable green protein products have necessitated research into alternate emerging and underutilized sources of protein to complement or supplement the major plant protein in the market- soy, pea, and gluten. Therefore, this dissertation is focused on the valorization of the proteins in proso millet. Specifically, this work focused …

Management Of Sugarcane Aphid (Melanaphis Sacchari) Using Biological And Cultural Tactics In Kentucky, Nathan Harriman Mercer

Theses and Dissertations--Entomology

In 2013, a new aphid pest of sorghum, the sugarcane aphid Melanaphis sacchari Zehntner (Hemiptera: Aphididae), was found in the southern US, and caused significant yield loss in sorghum. Since then, M. sacchari has spread to most of the sorghum growing regions. Unmanaged populations can cause complete crop loss in grain, forage and sweet sorghum. M. sacchari cannot survive winters without a live plant tissue and must recolonize much of its pest range annually. Sweet sorghum (Sorghum bicolor) is an important crop for many growers in Kentucky, producing $16-25 million a year from its syrup. Biological control of …

Physiological Ecology Of Overwintering And Cold-Adapted Arthropods, Leslie Jean Potts

Theses and Dissertations--Entomology

Given their abundance and diversity, arthropods are an excellent system to investigate biological responses to winter. Winter conditions are being majorly impacted by climate change, and therefore understanding the overwintering biology of arthropods is critical for predicting ecological responses to climate change. In Chapters 2 and 3, I investigate the winter biology of a winter-active wolf spider. I show that winter-active spiders can take advantage of periodic prey resources and grown in the winter, which may allow them to get a jumpstart on spring reproduction. I also investigate spiders’ ability to track changes in their environment by quantifying low temperature …

Emerald Ash Borer Development Across A Latitudinal Gradient: Implications For Biocontrol, Sarah Pellecchia

Theses and Dissertations--Entomology

Emerald ash borer, EAB, (Agrilus planipennis Fairmaire) is an invasive beetle that kills ash trees. It was accidentally introduced from China, and has rapidly expanded across North America, now occupying much of the eastern US. Four classical biocontrol parasitoids have been released to help mitigate its spread and impact: Tetrastichus planipennisi Yang, Spathius agrili Yang, S. galinae Belokobylskij and Strazanac, and Oobius agrili Zhang and Huang. These parasitoids have been deployed throughout EAB’s invaded range, but there has been limited recovery of the parasitoids from their release sites in southern states. I evaluated whether this lack of establishment might …

Identification And Characterization Of Epigenetic Regulators In The Yellow Fever Mosquito, Aedes Aegypti, Shankar C. R. R. Chereddy

Theses and Dissertations--Entomology

Due to the increased interactions between the sylvatic and urban cycles of Aedes aegypti life cycle, there has been an increase in the incidence of vector-borne diseases. The risk involved through the transmission of viruses like Dengue, Zika, Yellow-fever and Chikungunya calls for an effective control method for the deadly vector. The possibility of pesticide resistance and the costs involved in producing new pesticides have pushed Sterile Insect Technique (SIT) into prominence. However, current methods used to sterize insects for SIT are not highly efficient. This study tackles current issues in mosquito control by identifying and characterizing epigenetic regulators that …

A Tangled Web: The Dynamics Of Endosymbiotic Infections In A Linyphiid Spider, Laura Cecilia Rosenwald

Theses and Dissertations--Entomology

Many arthropods are infected with bacterial endosymbionts that manipulate host reproduction, but few bacterial taxa have been shown to cause such manipulations. Mermessus fradeorum (Linyphiidae) is a sheet-weaving spider that displays both feminization and cytoplasmic incompatibility (CI). To correlate reproductive manipulations to endosymbionts, I surveyed the bacterial community of M. fradeorum using high throughput sequencing and found that individuals can be infected with up to five different strains of bacteria from the genera Wolbachia, Rickettsia, and Rickettsiella. Rickettsiella was found in all 23 tested spider matrilines. I used antibiotic curing to generate uninfected matrilines that I reciprocally crossed with …

Developing Alternative Practices For Management Of Flea Beetles Attacking Eggplant And Leafy Brassicaceous Greens, Robert Brockman

Theses and Dissertations--Entomology

Flea beetles are a challenging pest for many producers of vegetable crops in Kentucky. Chewing numerous small holes in the leaves of their host plants, high flea beetle populations can quickly overwhelm unestablished crops. I tested the efficacy of several alternatives to insecticides within brassicaceous leafy greens and eggplant. Four field trials in 2019 and 2020 compared essential oil sprays, the woven-mesh row cover ProtekNet, the spunbonded row cover Agribon, and reflective silver mulch to an untreated control, a conventional insecticide rotation of dinotefuran and pyrethroids, and an organic insecticide rotation of spinosad and pyrethrins. The silver reflective mulch was …

Management Of Stink Bugs (Hemiptera: Pentatomidae) On Soybean In Kentucky, Yaziri Gonzalez

Theses and Dissertations--Entomology

Phytophagous stink bugs (Hemiptera: Pentatomidae) are pests of significant importance to soybean, Glycine max (L.), because they can cause severe losses in seed quality, ultimately affecting yield. Damage to soybean is caused through a process called extra-oral digestion. This occurs when the adults and nymphs of stink bugs pierce plant tissues with their mandibular and maxillary stylets, insert digestive enzymes, break down tissue, and extract the digested plant fluid. Three endemic stink bug species of North America are present in Kentucky: green stink bug (Chinavia hilaris), brown stink bugs (Euschistus species complex), and red-shouldered stink bug (Thyanta custator) …

Epigenetic Regulation Of Hormone Action In The Red Flour Beetle, Tribolium Castaneum (Herbst), Smitha George

Theses and Dissertations--Entomology

Hormones are the chemical communication signaling molecules released into the body fluid to stimulate target cells of multicellular organisms. Two major hormones, ecdysteroids (20-hydroxyecdysone, 20E) and juvenile hormones (JH), regulate a wide variety of physiological and developmental processes in insects. Therefore, hormones have been extensively studied and are attractive targets for the development of target-specific insect control methods. Recent studies suggest that epigenetics adds another layer of regulation to explain multiple functions of the same circulating hormone in different tissues and at various time points. In my dissertation, I focused on a major post-translational modification, ‘acetylation,’ to elucidate the epigenetic …

Emotional Closeness Within Romantic Relationships: Is There Transmission Between Generations?, Mckenna Diane Fey

Theses and Dissertations--Family Sciences

This study tested the existence of intergenerational transmission of romantic emotional closeness using Galovan and Schramm’s (2018) model of relationship flourishing as a theoretical backbone. Romantic emotional closeness in the present study included intimacy (i.e., self-disclosure), admiration (i.e., appreciation expression), and dyadic coping. Couples among three generations from the Panel of Analysis of Intimate Relationships and Family Dynamics (Brüderl et al., 2013) were examined to test whether romantic emotional closeness in the first generation predicted romantic emotional closeness in the second generation, and whether that of the second generation predicted that of the third. Regressions within a partial latent model …

Does Parental Stress Influence Parent-Child Sexual Communication?, Kirstie Otto

Theses and Dissertations--Family Sciences

This study shined a light on the impact of parent’s sexual attitudes and parental stress has on parent-child sexual communication. A sample of 203 parents between the ages of 30 and 60 were recruited to complete an online survey about their levels of parental stress, their sexual attitudes, and how often they discuss sexual communication with their adolescents. Beliefs that the responsibility of birth control should be shared between all parties involved, set the foundation that there will be higher levels of parent-child sexual communication. These findings inform therapists about the importance of creating a safe place where families can …

The Development Of A Couple Observational Coding System For Computer-Mediated Communication, Martha S. Rackets

Theses and Dissertations--Family Sciences

Many romantic couples integrate text and computer-mediated communication (CMC) into their relationship dynamics, both for general relationship maintenance and for complex dynamics such as problem solving and conflict. Romantic couple dynamics are interactional, dynamic, and sequenced in nature, and a common method for studying interactions of this nature is observational analyses. However, no behavioral or observational coding systems exist that are able to capture text-based transactional couple communication. The main purpose of this dissertation was to develop an observational coding system that can be used to assess sequenced computer- mediated, text-based communication that takes place between romantic partners. This process …

Cardiac Effects Of Obesity During Pregnancy In C57bl/6j Mice, Kayla Lynn Dudick

Theses and Dissertations--Nutrition and Food Systems

Objective: Pregnancy requires profound cardiac and metabolic adaptation. Left ventricular (LV) mass is increased in response to pregnancy, but is not associated with cardiac damage. In contrast, obesity-mediated cardiac hypertrophy is pathological. Data from animal studies indicate dietary fatty acid composition may have a protective effect during states of extreme cardiac physiological adaptation. In contrast, aberrant cardiac metabolism is a hallmark of disease. Over a third of reproductive-age women in the United States are obese, but there is a paucity of data describing the effect of obesity on maternal cardiac adaptation to pregnancy. The objective of this study was to …