Digital Commons Network^™

Examining The Role That Agricultural Education Programs Play In Student Choice Of Production Agriculture Careers, Wesley Estes

Murray State Theses and Dissertations

This dissertation explores the influence that Agriculture Education programs, at all levels, have on student choice of careers in production agriculture. The average age of a farmer in the United States is increasing, and the shortage of young people returning to family farming operations (or beginning operations of their own) becomes more apparent each year. This study utilizes focus groups of professionals to gather information about the factors that influence student choice in agriculture careers, and the ability of agriculture education programs to either enhance or mitigate those factors. For the purposes of this study, Agriculture Education programs of all …

Silence Is Not Golden: Exploring The Trade-Offs Between Transparency And Burden In Dirs Reporting, Katie Nelson

Murray State Theses and Dissertations

This study explores the United States federal government's Disaster Information Reporting System (DIRS), which is an instrument that is used during emergencies to gather information on what five communication avenues are not actively working at the time of the emergency or during the recovery process. The synthesis provides a framework for characteristics that cite the necessities for this study on DIRS. Examining DIRS will help us understand its strengths, limitations, and potential improvements. Evaluating the details of historical and global research on emergency communications are gathered. The analysis provides insights into DIRS's past, present, and future. Bring to light future …

Regulation Of Diabetic Cardiomyopathy Through Mitochondrial Import Of Long Non-Coding Rnas, Andrew Dodge Taylor

Graduate Theses, Dissertations, and Problem Reports (ETD)

Introduction: The leading cause of mortality in patients with diabetes mellitus is heart failure. When mitochondrial health and function is disrupted, cardiac contractile function is compromised. Therefore, understanding mitochondrial regulation may benefit predicting and countering diabetic cardiomyopathy. MicroRNAs (miRNAs) play a crucial role in diabetic cardiac mitochondrial protein expression. Long noncoding RNAs (lncRNAs) have been shown to regulate miRNAs, but not in the mitochondrion. Additionally, it has yet to be confirmed if lncRNAs utilize the same mechanisms for mitochondrial import that miRNAs use, or if lncRNA presence in the mitochondrion fluctuates in diabetic mitochondria like miRNA presence does. The …

The Effects Of Diet-Induced Obesity On Cerebral Microvascular Bioenergetics, Alec Anthony Hanshew

Graduate Theses, Dissertations, and Problem Reports (ETD)

Obesity is a worldwide epidemic but is especially a concern in the United States with over 40% of the population being obese. Obesity is known to cause increased metabolic demand, systemic inflammation, peripheral vascular dysfunction, and increased levels of oxidative stress and reactive oxygen species (ROS). However, the role of obesity on cerebrovascular bioenergetic function has not been fully elucidated. This study aimed to determine the impact of diet-induced obesity on cerebrovascular bioenergetics. 72, 6-month-old C57Bl/6 male and female mice were randomized into control and HFD groups. Control mice were subjected to the feeding of standard chow (18% fat, 24% …

Investigation Of Synergistic Effect Between Polystyrene And Polyethylene Under Conventional Thermal Heating And Microwave Heating, Thang Luong

Graduate Theses, Dissertations, and Problem Reports (ETD)

Single-use plastics (Low Density Polyethylene, LDPE; Polystyrene, PS; Polypropylene, PP) are increasingly used in the modern world, with their usage growing every year. An effective method to manage the resulting waste is urgently needed, as landfilling and incineration have proven harmful to the environment in the long term. Mechanical recycling may not maintain the desirable characteristics of the single-use plastics through several cycles. Pyrolysis emerges as a promising approach to address plastic waste. Given that single-use plastic waste often comes in a mixture, combining plastic in the feedstock is a viable solution to effectively convert these polymers altogether to gain …

Astrocyte Reprogramming By Th17 Cells In Autoimmune Neuroinflammation: Mechanisms And Implications, Sarah Marie Milne

Graduate Theses, Dissertations, and Problem Reports (ETD)

Multiple sclerosis (MS) is a cell-mediated, demyelinating autoimmune disease that affects the central nervous system (CNS). T helper (Th) 17 cells mediate the pathogenesis of MS and its animal model, experimental autoimmune encephalomyelitis (EAE), in part by infiltrating the CNS and interacting with astrocytes, a resident glial cell. Astrocytes are central to coordinating several inflammatory processes in the CNS and can respond to cytokines and chemokines produced by encephalitogenic Th17 cells. Pathogenesis of MS and EAE requires the infiltration of immune cells from the periphery, including autoreactive T cells, B cells, monocytes, and neutrophils, that lead to neuroinflammation, demyelination, and …

Translational Approaches To Address The Metastatic/Resistant (Mr) Phenotype Of Non-Small Cell Lung Cancer Brain Metastases, Kent L. Marshall

Graduate Theses, Dissertations, and Problem Reports (ETD)

Lung cancer remains the most frequently diagnosed malignant neoplasm shared in men and women worldwide, second only to the sexually dimorphic prostate cancer in men and breast cancer in women. Overall, lung cancer was responsible for 12.5% of new cancer cases globally in the year 2022. Of these cases, 80-85% are non-small cell lung cancer (NSCLC), a highly genotypically diverse sub-type of lung cancer. Over the past three decades, extraordinary improvement in screening, smoking cessation, early diagnosis and targeted therapy have been made, improving NSCLC survival markedly. However, as patients are surviving their primary disease better, there is a temporal …

The Identification And Characterization Of Novel And Improved Antigens For Next-Generation Pertussis Vaccines, Gage Michael Pyles

Graduate Theses, Dissertations, and Problem Reports (ETD)

Whooping cough, or pertussis, is a highly infectious respiratory disease caused by infection with the Gram-negative bacterial pathogen Bordetella pertussis. Pertussis affects all age groups and populations; however, it is most severe in infants who are too young to receive vaccinations and remains a global health concern with more than­­­­ 200,000 cases reported globally in 2023. Vaccines against pertussis have been available in the United States since the 1940’s with the development and widespread use of whole cell pertussis vaccines. Following their introduction, the incidence of pertussis was controlled and limited to fewer than 5,000 cases per year. Despite …

Endogenous Glucocorticoid Signaling Is Required For Normal Macrophage Response To H. Pylori Infection, Stuti Khadka

Graduate Theses, Dissertations, and Problem Reports (ETD)

Gastric cancer is the fifth leading cause of cancer-related deaths worldwide, affecting millions of people. H. pylori is the strongest risk factor for gastric cancer, with about 90% of the cases strongly associated with H. pylori infection. Half of the world's population is infected with this bacterium. However, only a small subset of the infected population (1-3 %) go on to develop gastric cancer. Diagnosis of the disease at an early stage is the biggest challenge because of the widespread prevalence of H. pylori infection and a long asymptomatic phase before the advanced stages. Patients are left with limited treatment …

Cellular Level Changes Induced In Cancer Cells Due To Microgravity, Sai Deepika Reddy Yaram

Graduate Theses, Dissertations, and Problem Reports (ETD)

The increase in human activity in space has revealed several kinds of physiological challenges brought on by the absence of Earth's gravitational pull. NASA observed that during spaceflight, astronauts experience a 1-1.5% monthly loss in the mineral density of weight-bearing bones, with rehabilitation efforts on Earth often proving ineffective. This issue extends to muscles, the neuro vestibular system, the cardiovascular system, and vision. Cancer has emerged as a significant cause of mortality among astronauts, with studies up to 2017 showing that 41.3% of natural cause deaths among U.S. astronauts were due to cancer, primarily due to space radiation exposure. Cancer …

Evaluating The Efficacy Of The Archaeal Proteasome To Alleviate Protein-Misfolding Retinopathy, Celine Brooks

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nearly all neurodegenerative diseases (NDs) and some eye diseases are characterized by the presence of misfolded and aggregated proteins. The ubiquitin proteasome system (UPS) is responsible for degrading the majority of proteins including misfolded and aggregated proteins. However, in NDs the performance of the UPS is impaired, and this impairment partially comes from these protein aggregates inhibiting the proteasome. This inhibition leads to an accumulation of protein aggregates, more proteasomal inhibition, and fewer chaperones for newly synthesized proteins, triggering a collapse in proteostasis, which is thought to contribute to the pathogenesis of NDs. Consequently, stimulating proteasome function is being investigated …

Performance And Physiological Impacts Of Branched-Chain Amino Acid And Tryptophan Ratio Variations In Turkey Starter Diets Utilizing Concentrated Corn Proteins, Emily Blair Estanich

Graduate Theses, Dissertations, and Problem Reports (ETD)

In Chapter 2, a study was designed to evaluate the effects of varying dietary branched-chain amino acids (BCAA) ratio in corn and soybean meal-based turkey starter diets. The BCAA leucine, isoleucine, and valine are considered indispensable amino acids needed for energy and stimulation of muscle protein synthesis via the mammalian target of rapamycin (mTOR) pathway. Imbalanced BCAA ratios can lead to antagonism and degradation of limiting BCAA, particularly in diets with excess leucine. Concentrated corn proteins contain high levels of leucine and can alter BCAA requirements; however, crystalline BCAA may be added to correct these ratios. This study aimed to …

Measures Of Feed Efficiency In Beef Cattle: Biological Basis And Effect On Response To Dietary Supplementation, Modoluwamu Idowu

Graduate Theses, Dissertations, and Problem Reports (ETD)

During the feedlot receiving period, newly weaned beef cattle face various stressors, including weaning, transportation, vaccination, and exposure to pathogens. Additionally, changes in diet and low dry matter intake contribute to nutrient deficiencies, heightening susceptibility to disease and performance declines. Therefore, we examined the effects of dietary supplementation with a multicomponent blend of prebiotics and probiotics on the health, immune status, metabolism, and performance of newly weaned beef steers during a 35-day receiving period. Our results showed that compared to the control group, the supplemental additive (SYNB) increased average daily gain (ADG), dry matter intake, and meal events during the …

Return To Soil, Lindsay Jo Mccarty

Graduate Theses, Dissertations, and Problem Reports (ETD)

This document outlines my artistic research on building a symbiotic relationship with land throughout life and death, eco-philosophy, and the significance of natural decomposition. It explores green burial practices in Western society, delves into the history of basketry, and draws inspiration from the mutualistic effort of returning our organic energy to the Earth. The recontextualization of what “death” is and reciprocal outlooks are central to this work. My aim is to honor this cycle through creations that incorporate plant matter in hopes that, one day, I can create artwork with completely compostable materials.

My art embodies these themes and is …

Synaptic Zinc Transporters Support Normal Synapse Structure And Function In Mouse Auditory Cortex, Abbey Manning

Graduate Theses, Dissertations, and Problem Reports (ETD)

Many regions of the brain are highly enriched with free zinc inside glutamatergic vesicles at presynaptic terminals. At these synapses, zinc transporter 3 (ZnT3) moves zinc into vesicles where it is co-released with glutamate. Alterations in ZnT3 are implicated in multiple neurodevelopmental disorders, and ZnT3 knock-out (KO) mice – which lack synaptic zinc – show behavioral deficits associated with autism spectrum disorder and schizophrenia. Shank3 is a synaptic scaffolding protein that assists in tethering and organizing structural proteins and glutamatergic receptors in the postsynaptic density of excitatory synapses. The localization of Shank3 at excitatory synapses and the formation of stable …

The Effects Of Forgetting And Disclosure On Mock Jurors' Perceptions Of An Alleged Rape, Johnathan Meier

Graduate Theses, Dissertations, and Problem Reports (ETD)

Memory recall and forgetting is a complex process. Memories can be completely forgotten (e.g., Ebbinghaus, 1885/1964; Murre, 2015) or repressed and recovered at a later time (e.g., Key et al., 1996; Foster-Lee et al., 1999). Instances of sexual assault may be disclosed to a close acquaintance or medical professional at the time of the event or kept secret until the time of reporting to authorities (e.g., Pica et al., 2020a). In the current study, mock jurors’ perceptions of credibility and guilt, as well as the amount of compensation awarded to the plaintiff, will be assessed in response to testimony depicting …

An Inhibitory Recurrent Network In The Olfactory System, Farzaan Salman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neuromodulatory circuits are a necessary component of neural flexibility as they are able to act differentially depending on the receptors expressed by their downstream targets. Identifying the synaptic partners of modulatory neurons and determining the neurotransmitter and receptor content of these partners is necessary to identify the rules governing neuromodulatory circuits. In this study, I characterized the circuit of the contralaterally projecting, serotonin-immunoreactive deutocerebral neurons (CSDns), the sole synaptic source of the neuromodulator serotonin in the olfactory circuit of Drosophila melanogaster, by identifying the strongest synaptic partners of the CSDns, and the expression of genes encoding neurotransmitters and receptors of …

A Balancing Act: Microrna Mediated Insect-Bacterial Homeostasis And The Tsetse Fly, Mason Hubbard Lee

Graduate Theses, Dissertations, and Problem Reports (ETD)

Microbial symbioses are ubiquitous across all kingdoms of life with broad and diverse impacts on the evolution of species. The sum of all microbes living in, on, or otherwise in close association with a host form the microbiota. In some cases, the development of a stable microbial association seems to have been necessary for the specialization of diet, as can be observed in numerous insect species, especially wood-eating, sap-feeding, and blood-feeding organisms. For the medically and economically tsetse fly (family Glossinidae), the mutualistic bacteria Wigglesworthia glossinidia is required for proper reproduction and supplementation of nutrients that the fly does not …

Sars-Cov-2 Immunogenicity Models Inform Novel Strategies That Can Improve Mrna Vaccines, Katherine S. Lee

Graduate Theses, Dissertations, and Problem Reports (ETD)

The onset of the 2020 COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, issued a call to action in the fields of biomedical science and public health to implement strategies to contain and protect against the viral threat. In record times, pharmaceutical companies produced antiviral therapies and novel mRNA vaccines that were approved by the FDA for human use. With time, these vaccines were able to assist in ending the pandemic. However, time also showed the limits of mRNA vaccine induced immunity. Despite antibody responses being initially robust, titers dramatically wane with time and are limited in cross-neutralizing ability. As …

Cerebellar Feedback Effects On Responses To Conspecific Signals Of Different Frequencies In The Electrosensory System, Elora K. Shinn

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sensory systems in animals have evolved to translate physical stimuli into neural representations that, in turn, guide behavior. Feedback is critical in these processes, allowing organisms to filter redundant information and respond effectively to relevant stimuli. In humans, for example, the cerebellar flocculus provides feedback to the vestibulo-ocular reflex to stabilize eye movements during body rotation. In bats, the feedback during echolocation helps prioritize essential signals from the environment. In weakly electric fish, cerebellar feedback helps filter out redundant low-frequency modulations caused by conspecifics, enabling them to detect prey and other relevant signals. However, the influence of cerebellar feedback on …

Investigation Of L-Serine Synthesis And Transport As Stabilizing Feedback Mechanisms Within The Tsetse-Wigglesworthia Symbiosis, Ryan Phillips

Graduate Theses, Dissertations, and Problem Reports (ETD)

Tsetse flies (Glossina morsitans), which are the obligate vectors of Old-World trypanosomes (Trypanosoma spp.) that cause African trypanosomiasis, have a bacteriome that houses the intracellular endosymbiont Wigglesworthia glossinidia. The ancient coevolution of these species has led to the integration of Wigglesworthia metabolism into tsetse physiology and a subsequent reliance on nutrient exchange for maintaining the fitness of both partners. The establishment of this obligate mutualism has facilitated the emergence of feedback mechanisms that stabilize the symbiosis, such as that which involves the exchange of L-serine and B vitamins. The Gammaproteobacteria Wigglesworthia supplement B vitamins lacking …

The Function Of Protein Glutamylation In Vision, Rawaa Aljammal

Graduate Theses, Dissertations, and Problem Reports (ETD)

Posttranslational glutamylation of protein has emerged as a novel candidate for cellular integrity. In a dynamic process, Tubulin Tyrosine Ligase Like proteins (TTLLs) introduce glutamate groups to their substrates, while Cytosolic Carboxypeptidases members (CCP1-CCP6) remove these glutamate groups. The outcome of this interplay is a wide range of substrates; each is glutamylated to a level crucial for its function.

Protein glutamylation is particularly abundant in neurons and in the axoneme of cilia and flagella. This distribution, along with the correlation between imbalanced glutamylation levels and compromised cellular functions, underscores the significance of protein glutamylation in maintaining cellular viability. However, the …

Structural And Functional Consequences Of Pde6 Prenylation In Rod And Cone Photoreceptors, Faezeh Moakedi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Phosphodiesterase-6 (PDE6) serves as a pivotal component in the phototransduction pathways of both cone and rod photoreceptors. In cones, PDE6 consists of tetrameric subunits: inhibitory (γ') and catalytic (α'). The catalytic subunit, PDE6α', contains a C-terminal prenylation motif. Deletion of this motif is associated with achromatopsia (ACHM), a form of color blindness. The mechanisms underlying the disease and the roles of PDE6 lipidation in vision remain elusive. Meanwhile, rod PDE6 is composed of α and β catalytic subunits and γ inhibitory subunits, with alterations in the C-terminal "prenylation motif" of PDE6β linked to retinitis pigmentosa (RP) pathology. In this comprehensive …

A Legacy Of Labor: Maternity Narratives In 1960s And 1970s North American Life Writing, Katelynn Ann Vogelpohl

Graduate Theses, Dissertations, and Problem Reports (ETD)

Abstract

A Legacy of Labor: Maternity Narratives in 1960s and 1970s North American Life Writing

Katelynn Ann Vogelpohl

The phenomenon of maternity has been repeatedly described as an event that shakes the very foundations of social and physical identity. As the flesh of the pregnant person literally divides to produce new life, one subject becomes enclosed within another, dramatically affecting the pregnant person’s sense of self and causing a confluence of intense, and often conflicting, feelings. In North America, there are two dominant, and seemingly opposing, discourses on pregnancy and childbirth: the institutional medical discourse and the natural childbirth discourse. …

Assessing The Impact Of Olive Oil And Flaxseed Oil Supplementation On Hypertension And Inflammation In Healthy And At-Risk Adults, Tara Bess Mcnabb

Graduate Theses, Dissertations, and Problem Reports (ETD)

Background: Supplementation of olive oil and flaxseed oil and their impacts on hypertension and inflammation have been reported for healthy and hypertensive adults. However, a comprehensive systematic literature review and meta-analysis on the preventive benefit of plant oil supplementation in healthy adults and adults at risk of inflammation inducing hypertension is lacking.

Objective: to evaluate human clinical trials assessing the impact of olive oil and flaxseed oil capsules on systolic blood pressure (SBP) and diastolic blood pressure (DBP) and select inflammatory markers in non-hypertensive and at-risk adults of hypertension.

Data sources: Four databases were searched in October 2023 …

Investigating Birds As Dispersal Vectors Of Litylenchus Crenatae Subsp. Mccannii (Anguinidae), The Nematode Associated With Beech Leaf Disease, Spencer Rock Parkinson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Beech leaf disease (BLD) is an emerging forest pathogen primarily affecting American beech (Fagus grandifolia, Ehrh.) in North America and has been attributed to tree mortality of sapling sized trees within five to seven years of infection. Symptoms typically occur in regenerating American beech thickets sprouting from roots of trees killed by beech bark disease. Scientists first observed BLD in Ohio in 2012 and currently has spread to 15 states in the USA and one Canadian province. The nematode Litylenchus crenatae subsp. mccannii (Lcm) is highly associated with BLD symptoms, interveinal chlorosis and defoliation of leaves, and is currently …

Theorizing Mathematical Proof As Becoming: A Deleuzio-Guattarian Investigation, Joshua P. Case

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this dissertation, I utilize the post-structural philosophy of Gilles Deleuze and Félix Guattari as a lens for investigating the proof process. Deleuze and Guattari were both post- structural philosophers who, like many in this tradition, troubled traditional notions related to stable identities, meaning, language, and mathematics. For Deleuze, sense and meaning is not the result of a sterile, transcendent effect or condition that is associated with propositions and states of affairs. Rather, it is the result of a material production that emerges from the world and that has independence from language and the mind. I apply this framework to …

Adverse Childhood Experiences Predict Mortality Risk: The Role Of Social Support & Social Strain, Meredith A. Willard

Graduate Theses, Dissertations, and Problem Reports (ETD)

Childhood adversity has long-lasting negative effects across the lifespan including increased mortality risk. The love and support individuals receive from others, also known as social support, has shown to be a protective factor against ACEs. However, little research has investigated the amplifying effects of social conflict and strain that often accompanies social relationships. Utilizing data from the Midlife Development in the U.S. (MIDUS) study, I tested whether higher levels of social support would buffer the negative effects of adverse childhood experiences on mortality risk, and whether higher levels of social strain would amplify these associations. The sample included 6,150 participants …

Development And Application Of Functional Immune Assays To Understand Disease In Wild Smallmouth Bass Populations, Cheyenne R. Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

Over recent decades, the scientific community has observed a disconcerting trend – a decline in the health and stability of smallmouth bass (Micropterus dolomieu) populations across the Chesapeake Bay watershed with growing economic and ecological implications. Disease, declines, and death have been observed in multiple locations, particularly in the Susquehanna and Potomac drainages with the adults disproportionately affected in the Potomac River basin and young-of-year in the Susquehanna River basin. There has not been a single or consistent cause to the declines or mortality events. More likely, it is believed immunosuppression relating to a complex mixture of stressors has been …

The Sex Chromosome Complement And Gut Microbiome Act Independently And Collaboratively To Impart Sex Dimorphisms In Humoral Immunity, Carly J. Amato-Menker

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sex dimorphisms in immunity are well-documented and have significant clinical implications. While the immunomodulatory effects of sex hormones have been extensively documented, recent recognition of the nuanced contributions of the sex chromosome complement (XX vs. XY) and the gut microbiome to immune sex dimorphisms underscores the need for a more comprehensive understanding. Within this context, the work herein focuses on unraveling the individual and collaborative impacts of the sex chromosome complement and gut microbiota on humoral immune activation. We assessed humoral immune responses to immunization with heat-killed Streptococcus pneumoniae (HKSP) in Four Core Genotype (FCG) mice and found elevated IgM-secreting …