Digital Commons Network^™

Structure Activity Relationship Studies Of An Anticryptosporidial Drug, Kirtika Chatri

Graduate College Dissertations and Theses

Cryptosporidium is an apicomplexan parasite responsible for waterborne outbreaks of diarrheal disease worldwide. There are two species of Cryptosporidium that are important enteric pathogens for humans. The disease, Cryptosporidiosis, is a major cause of childhood diarrhea and an important factor in childhood malnutrition and also a high rate of death (Sparks et al., 2015). It is also more frequent and severe in malnourished children under 3 years of age and immune-compromised individuals, such as AIDS and transplant patients. A common treatment which has greatly reduced diarrhea-associated mortality is oral rehydration therapy; however, enteric infections still persist (Guerrant, DeBoer, Moore, Scharf, …

Analysis Of Intracellular Calcium Events In Hypothalamic Neurons, Samantha Kolowrat

Graduate College Dissertations and Theses

The paraventricular nucleus of the hypothalamus (PVN) plays a critical role in regulating the hypothalamic-pituitary-adrenal (HPA) axis, sympathetic activity, cardiovascular system and stress responses.1,2 This brain region is primarily controlled by GABA and glutamate inputs from the peri-PVN region.3 Two significant modulators of these GABA-glutamate systems are Angiotensin II (Ang II) and brain derived neurotrophic factor (BDNF). It has been postulated that BDNF and Ang II signaling rely on each other via cross-activation of their receptors and by activation of the non-selective cation channel, the transient receptor channel type C3 (TRPC3).This thesis aims to study changes in intracellular calcium levels …

The Effects Of Interneuron Progenitor Cell Transplantation On Network Dynamics In An Animal Model Of Mesial Temporal Lobe Epilepsy, Willie Curry

Graduate College Dissertations and Theses

Epilepsy is associated with a very high incidence of cognitive and behavioral comorbidities that are detrimental to overall quality of life. Current treatments for epilepsy,namely anticonvulsant pharmacological agents, generally increase the amount of inhibitory drive in order to counteract the hyperexcitability observed in the disorder. However, administration of these agents, while effective for 70% of epilepsy sufferers, leave a residual 30% of patients who don’t become seizure-free. The concomitant adverse side effects of anticonvulsants - these can paradoxically include increased cognitive "fog" or confusion, automatisms, and even increased number of seizures - are a great additional concern, as is the …

Structural Characterization Of The Novel Flightin Domain Wyr And Its Defining Role In The Thick Filament Structure And Mechanics, Lynda Menard

Graduate College Dissertations and Theses

The evolutionary success of Insecta has been attributed largely to the development of efficient means of motility: flight powered by muscle architecture harboring a largely conserved yet tunable system of power relay. The indirect flight muscle (IFM) of Drosophila melanogaster is a well-studied model for dissection of the structural and mechanical means by which muscle operates and evolves. Striated muscle, conserved throughout Animalia, is demarcated by an ordered array of thick- and thin-filaments prominently composed of the proteins myosin and actin. Flightin (fln) is a myosin binding thick filament protein essential for IFM stability, structure and function. The manner by …

Network And Cellular Effects Of The Mu Opioid Receptor In Cortical Interneurons, Adrian Dutkiewicz

Graduate College Dissertations and Theses

The µ opioid receptor (µOR) exerts a powerful excitatory effect in cortical circuits and cultured neurons by promoting glutamatergic activity after binding endogenous or exogenous opioids. While most research indicates that the receptor does this by decreasing activity or output of GABAergic interneurons that inhibit glutamate-releasing Pyramidal Neurons, other experiments suggest that the µOR directly upregulates excitatory Pyramidal Neurons instead. Thus, the cellular target of cortical opioid agonists remains unclear, and the µOR’s net excitatory mechanisms are not fully understood. Consequently, utilizing electrophysiology to detect µOR responses to the specific agonist [D-Ala2, N-Me-Phe4, Gly5-ol]-Enkephalin (DAMGO) has yielded incomplete information on …

Effect Of Long-Term Dietary Fat Quality On Metabolic Health With A Special Focus On Dairy Fat, Allison L. Unger

Graduate College Dissertations and Theses

Diet, and particularly dietary fat quality (i.e., fatty acid composition), is a significant modifiable risk factor in the development of metabolic diseases. However, whether the manipulation of long-term dietary fat quality may serve as an effective dietary strategy to mitigate metabolic disease risk during aging is not well defined. Accordingly, this work sought to investigate the role of life-long consumption of bioactive fatty acids from various food sources, and particularly dairy fat, on health maintenance and metabolic disease risk later in life. To address this issue, I assessed how long-term supplementation of dairy fat (butter oil), echium oil, or fish …

The Role Of Peroxiredoxin 4 And Er Redox Stress In Idiopathic Pulmonary Fibrosis, Evan Elko

Graduate College Dissertations and Theses

Idiopathic Pulmonary Fibrosis (IPF) is a disease that is characterized by excessive scar formation in the lung. IPF is a disease associated with aging and is believed to be the manifestation of repeated micro-injuries and lack of adequate repair over time. Notably increases in endoplasmic reticulum (ER) stress of epithelial cells and excessive epithelial cell death have been identified as processes that drive the progression of fibrosis. Every year 34,000 people in the United States are diagnosed with Idiopathic Pulmonary Fibrosis (IPF). The average survival time for these patients is only 3-5 years after diagnosis. Two available drugs stabilize patients …

Organic Amendments Alter Soil Hydrology And Belowground Microbiome Of Tomato (Solanum Lycopersicum), Taylor Readyhough

Graduate College Dissertations and Theses

Manure-derived organic amendments are a cost-effective tool that provide many potential benefits to plant and soil health. For example, amendment applications may increase soil fertility, improve soil structure, stimulate microbial activity, and suppress plant pathogens. Yet, responses to these applications may have unintended consequences. Inherent variability in the physical, chemical, and biological characteristics of these materials can result in inconsistent outcomes observed after their application. These differences are manifested in plant growth, soil physiochemical properties, and soil microbial community composition. Popular manure-derived organic amendments include dairy manure compost and poultry manure pellets. Dairy manure is an abundant resource on many …

The Effect Of Physically Effective Undegradable Neutral Detergent Fiber And Rumen Fermentable Starch On Lactating Holstein Cows, Katherine Mae Smith

Graduate College Dissertations and Theses

In the dairy industry, a common way of adding energy to the diet is in the form of fermentable starch. However, an overabundance of fermentable carbohydrates can cause a buildup of volatile fatty acids that exceed the buffering capacity of the rumen. These changes can lead to negative health consequences such as subacute rumen acidosis and milk fat depression. Not only does a cow need readily fermentable sources of energy in her diet, but she also needs physically effective structural carbohydrates.Fiber has been a difficult portion of the diet to characterize as both the chemical and physical properties are important …

Spillover, Dilution, And Coinfection: Understanding The Spread Of Disease Within Managed And Native Bee Communities., Phillip A. Burnham

Graduate College Dissertations and Theses

Maintaining healthy pollinator communities is vital both for ensuring food securityand ecological diversity. However, managed honeybees and wild bee communities are under threat from an array of stressors including habitat loss, global change, pesticide use, poor beekeeping, and various pests and pathogens. Pathogens have been shown to be spilling over from managed bees into wild bee populations and are known to adversely affect colony function as well as increase mortality. Understanding transmission mechanisms related to general dynamics in this system will not only benefit pollinator health, but also gives us insight into important and understudied topics in disease ecology. In …

Forest Development And Regeneration Dynamics In The Context Of Global Change And Associated Adaptation Strategies, Peter Clark

Graduate College Dissertations and Theses

Over the past century, forested ecosystems in northeastern North America have undergone significant changes characterized by the recovery from intensive land use and impacts from the introduction of invasive insects and disease. These changes, coupled with emerging threats posed by a changing climate present challenges to the maintenance and conservation of biodiversity, ecological functions, and delivery of critical forest ecosystem services. While management strategies to increase forest resilience and mitigate impacts from climate change have been broadly proposed, there are nascent empirical evaluations of their effectiveness. To address this uncertainty, this dissertation couples field manipulations with long-term measurements to examine …

Healthcare Professionals’ Perceptions Regarding The Nutrition Of Dairy And Plant-Based Dairy Alternatives, Bridget Clark

Graduate College Dissertations and Theses

Plant-based (PB) dietary patterns have seen an upsurge in popularity over the past two decades. With this, has come an increase in consumption of PB alternatives to animal food products, including alternatives to dairy. However, because PB dairy alternatives are nutritionally different from dairy, there is concern that consumers of these products may unknowingly fall short on essential nutrients in their diet. Healthcare providers are key sources of nutrition information for U.S. consumers. This work examined U.S. healthcare professionals’ beliefs and recommendations regarding dairy and PB dairy alternatives. Two methods were used: (1) analysis of all public comments submitted the …

Biofilm Sanitizer Tolerance Of Vermont Dairy Listeria Monocytogenes, Emily C. Forauer

Graduate College Dissertations and Theses

Listeria monocytogenes is a foodborne pathogen found in biofilms on surfaces and equipment in the food processing environment. Sodium hypochlorite (SH) and quaternary ammonium compounds (QAC) are readily available and commonly used sanitizers. However, due to the structure and additional organic material produced in a biofilm, killing bacteria within the biofilm may be a challenge for one or both of these sanitizers.

The objective of this work was to determine if immature and mature biofilms from L. monocytogenes isolated from Vermont artisan dairy environments were more tolerant to QAC and SH compared to planktonic cultures’ tolerance. To determine sanitizer minimum …

Examining Consumer Perceptions And Behaviors Toward Hemp-Based Products, Hannah Lacasse

Graduate College Dissertations and Theses

Although its relevance has ebbed and flowed, hemp production has persisted over several centuries. Over time, its popularity has been interrupted by competing products, public health concerns and regulatory barriers. A renaissance of hemp production has emerged in the U.S., particularly after regulatory barriers fell in 2014 and 2018. This has given rise to a growing market of diverse hemp-based food, medicinal, textile and industrial products. Adding to the political, technological and financial challenges facing this nascent industry is a demonstrated need for consumer behavior research on how products made with hemp-based ingredients are received, if at all, by consumers. …

Designer Biologics Composed Of Hepatocyte Growth Factor, Fibroblast Growth Factor 2 And Immunoglobulin G For Treatment Of Acute Myocardial Infarction, Benjamin Liebman

Graduate College Dissertations and Theses

ABSTRACT Coronary artery disease leading to myocardial infarction (a.k.a. MI, heart attack) is one of the leading causes of death globally. Each year an estimated 605,000 Americans suffer a heart attack, which equates to one MI every 40 seconds. As such, MI represents one of the largest health burdens to society. The current standard of care is revascularization therapy achieved by fibrinolytics and Percutaneous Coronary Intervention (PCI); both of which re-open occluded proximal arteries to restore blood flow to the affected areas. Despite revascularization therapy, 30-50% of patients exhibit a form of reperfusion injury termed “no/low-reflow” in which the blood …

Functional Characterization Of Leptomeningeal Anastomoses In Physiological Condition And Chronic Hypertension, Zhaojin Li

Graduate College Dissertations and Theses

Stroke is the second leading cause of death worldwide and the leading cause of devastating disability. Leptomeningeal anastomoses (LMAs) are small distal anastomotic vessels, also known as pial collaterals in the brain. These vessels redirect blood flow during an occlusion and are important for stroke treatment and outcome. Hypertension, a major risk factor for stroke, is associated with limited amounts of salvageable tissue, greater perfusion deficit and worse stroke outcome. Angiotensin II (Ang II), generated from angiotensin I by angiotensin converting enzyme (ACE), is importantly involved in the pathogenesis of hypertension. Despite the important clinical implications, functions of LMAs in …

Metarhizium Anisopliae, Metarhizium Brunneum And Beauveria Bassiana Formulations For Biological Control Of Larval Winter Ticks, Dermacentor Albipictus, Cheryl Sullivan

Graduate College Dissertations and Theses

There is a critical need to develop effective, high-quality, fungal-based biopesticides for use against ticks. Dermacentor albipictus Petch (Acari: Ixodidae), the winter tick, is a one-host tick. They commonly infest large ungulates, particularly moose, Alces alces L. (Artiodactyla: Cervidae) on which they cause significant physiological and metabolic stress on densely parasitized individuals. Heavily infested calves can be killed. Entomopathogenic fungi in the genera Metarhizium (Hypocreales: Clavicipitaceae) and Beauveria (Hypocreales: Cordycipitaceae) are promising tick biological control agents. The larval stage of D. albipictus aggregates on the ground in a prolonged, quiescent state during the summer and then quests for hosts in …

Influence Of Summer Hedging And Plant Growth Regulators On Apple Trees Grown For Hard Cider. An Evaluation Of Return Bloom, Tree Growth, And Juice Quality., Jessica A. Foster

Graduate College Dissertations and Theses

Fermented cider production has rapidly increased in the US over the last decade with an annualized growth rate of 50% between 2009 and 2014, and revenues totaling $ 2.2 billion in 2018 (Becot et al., 2016; Miles et al., 2020). Cider producers seek juice with high sugar, high acid, and phenolics that enhance ‘‘mouth feel’’ to make unique, high-quality cider. Specialty cider cultivars are selected for their juice qualities, not for their yield or ease of production. Growers have found many cider cultivars are challenging to grow due to disease susceptibility, biennial bearing, premature fruit drop, and excessive vegetative growth. …

Optimizing New In Vitro Methodologies For Assessing The Effects Of Mechanical Stimuli On Lung Cells: Implications For Lung Biology And Disease, Alicia E. Tanneberger

Graduate College Dissertations and Theses

Chronic lung diseases affect millions of people in the United States and are a leading cause of both morbidity and mortality. Studying how environmental factors affect lung cell biology and function is being increasingly recognized as a critical step in understanding lung disease pathogenesis and the development of new therapeutic approaches that combat lung diseases. These factors include lung extracellular matrix (ECM) composition and the mechanobiological factors of stiffness and cyclic mechanical strain, which during breathing, act on cells during the normal expansion and contraction of the lung. However, current methodologies for studying these factors have significant limitations and new …

The Impacts Of Asian Longhorned Beetle On Forests In Southern New England, Olivia Fay Box

Graduate College Dissertations and Theses

Over the past several decades, the United States has been experiencing an influx of nonnative pests due to increased globalization, and many of these pests have the potential to permanently alter the composition, structure, and function of forests. Asian longhorned beetle (ALB) is an invasive pest that came into Worcester county, MA in 2008, where the first instance of this species invading both urban and natural forested areas was documented. Within the quarantine area for this novel invasion, 30,000 trees were removed over the course of 10 years as part of management efforts focused on harvesting all host species, primarily …

Informing Adaptation Strategies For Northeastern Pitch Pine Barrens In The Context Of Mesophication And Southern Pine Beetle Impacts, Elizabeth-Ann Jamison

Graduate College Dissertations and Theses

Forest pests, the most significant agent of disturbance in forested ecosystems of North America, are highly sensitive to climate change. Southern pine beetle (SPB) is a highly destructive pine forest pest that is expanding its historic range in the southeastern US to affect the globally rare northeastern pitch pine barrens as winter temperatures warm. By generating high levels of mortality in canopy pitch pine, SPB is accelerating the ongoing conversion of fire-dependent pine barrens to mesophilic forests. We aimed to support the adaptive management of pine barrens ecosystems in the context of these two threats by (1) assessing stand conditions …

Mediators Of Bladder Dysfunction In A Rat Model Of Cyclophosphamide-Induced Cystitis, Katharine Beca

Graduate College Dissertations and Theses

The urinary bladder relies on complex and interconnected neural circuits in the peripheral and central nervous systems to properly coordinate micturition. Local sensory signals in the bladder produce neurochemical changes that are relayed and integrated to allow a switch from the storage phase to the elimination phase of the micturition reflex. These local signals can result from mechanical distension that occurs during bladder filling or can be the result of maladaptive neurotransmission due to noxious stimuli and/or inflammation. The latter occurs frequently in individuals with a chronic pain pathology called interstitial cystitis (IC)/bladder pain syndrome (BPS). Patients with IC/BPS typically …

Lcms-Based Analysis Explains The Basis Of Oxidative Resistance In Selenium-Containing Thioredoxin Reductase, Daniel Haupt

Graduate College Dissertations and Theses

Selenocysteine (Sec) is referred to as the 21st proteogenic amino acid and is found in place of the redox-sensitive amino acid cysteine (Cys) in a small number of proteins. Sec and Cys carry out similar chemistry and are structural isomers save for a single atom difference; the former contains selenium (Se), while the latter contains sulfur (S) in the identical position. Sec poses a high bioenergetic cost for its synthesis and subsequent incorporation into protein not shared by Cys. Since Sec’s discovery in 1976, scientists have debated why certain proteins express Sec while others express Cys. In recent years, it …

Characterization Of Higher Order Chromatin Structures And Chromatin States In Cell Models Of Human Herpesvirus Infection, Michael Mariani

Graduate College Dissertations and Theses

Human herpesviruses are ubiquitous pathogens worldwide with 90% of the global population infected with one or more Human herpesviruses (HHV’s) by adulthood. All herpesviruses have three unique life cycle stages. Upon resolution of a primary acute stage infection, they can establish a latent stage infection within the host cell nucleus. This stage is characterized primarily by transcriptional quiescence of the viral genome. Specific physiological conditions (e.g., cell stress) can cause the latent virus to enter the reactivation stage, often many years after resolution of the acute infection, in which the virus becomes replicationally active again. HHV’s are known to cause …

It’S More Than Profits: Examining Perceived Success In Agritourism, Lindsay Quella

Graduate College Dissertations and Theses

Over the last 20 years, small- and medium-sized farm owners are increasingly interested in participating in agritourism and direct sales in order to boost income, provide family employment, and educate the public about agriculture, among other reasons. A growing body of research has focused on agritourism from the provider perspective, but more research is needed in order to identify supports and barriers for agritourism operators. In order to address this gap, we first investigated how operators themselves define success, before studying the attributes that are associated with success in agritourism. While prior research acknowledges the strong influence of non-economic factors …

Investigating The Role Of Protein Kinase A In The Control Of Focal Adhesion And Traction Force Dynamics, Amanda Senatore

Graduate College Dissertations and Theses

Cellular adhesion to the extracellular environment is a critical component of physiological processes and its dysregulation drives pathological processes such as cancer metastasis. The input cells derive from their interaction with the extracellular matrix (ECM) is largely mediated through specialized organelles known as focal adhesions (FAs). FAs tether extracellular matrix-bound integrins to the contractile actin cytoskeleton and serve as attachment points which allow the cell to exert force on the extracellular environment via acto-myosin contractility. In addition to this structural role, FAs function as dynamic signaling hubs that respond to changes in force. Reversible phosphorylation plays a major role in …

Sarracenia Purpurea As A Model System For Aquatic Ecosystem State Changes And Their Impact On Bacterial Communities, Amanda Claire Northrop

Graduate College Dissertations and Theses

Aquatic ecosystems can undergo abrupt and long-lasting transitions from one state to another, often with negative ecological and economic consequences. With anthropogenic enrichment, aquatic ecosystems such as lakes and ponds may shift rapidly from an oligotrophic, clear water state to a eutrophic, turbid state. These shifts, or state changes, generally occur due to a phenomenon called hysteresis in which the relationship between a driving variable and ecosystem variable depend on the current state of the ecosystem. Such dynamics often make recovery difficult or impossible. Though state changes in aquatic ecosystems have been studied extensively since the 1970s, there have been …

Determinants Of Antibody Immunity In Flavivirus Infections And Immunization, Huy Tu

Graduate College Dissertations and Theses

The most significant arthropod-borne viral infections in modern history are caused by species of the Flavivirus (FV) genus due to their global transmission. While immunization is effective at decreasing the burden imposed by some FV, vaccines for other FV such as Dengue virus (DENV) and Zika virus (ZIKV) are still in development or not widely available. A better understanding of the protective immune response, specifically the antibody response, to DENV and ZIKV will advance the vaccine development endeavors for these viruses. Utilizing longitudinal samples from controlled human immunization/challenge studies and natural infections, we investigated the antibody response to these viruses …

Food From Somewhere: Envisioning And Practicing Aspirational Food Systems, Caitlin Morgan

Graduate College Dissertations and Theses

This transdisciplinary dissertation explores the connections between material conditions, human engagements, and the social, economic, and ecological contexts in which they exist. It investigates imaginations of a better food system, projects people have already undertaken, and what happens when their visions meet reality.

Chapter 1 weaves together diverse literature: a justification for action-oriented research and a blending of ecofeminist scholarship, agroecology and sustainable agriculture, ecological economics, systems theory and food systems scholarship, and sensory studies. These disciplines tie together through notions of embeddedness, embodiment, and the context for action, which all translate to the dissertation’s methodological approach of mixed qualitative …

Unique Genomic And Phenotypic Responses To Extreme And Variable Ph Conditions In Purple Urchin Larvae, Strongylocentrotus Purpuratus, April Dawn Garrett

Graduate College Dissertations and Theses

Given the unprecedented increases in atmospheric carbon dioxide and its projected negative impacts on organismal ecology and physiology, it is crucial to understand if and how organisms will withstand such environmental changes. Due to the oceans’ service as a carbon sink, marine organisms face the added stressor of ocean acidification (OA), the process by which carbon dioxide mixes with water and decreases pH while simultaneously depleting the seawater of calcium carbonate. Marine organisms that rely on calcium carbonate for exoskeleton development are considered particularly vulnerable to OA, though previous results vary among species, leading to the question of who the …