Life Sciences Commons^™

Autonomic Reactivity In Emerging Adulthood : Relationships Between Cyberbullying , The Autonomic Nervous System, And Clinical Outcomes., Aya Cheaito

Graduate College Dissertations and Theses

With the advent of the COVID-19 pandemic, online environments have become critical ways of connecting among college students. With the increase in online interactions, cybervictimization has been identified as a public health issue. This study aims to examine whether cybervictimization among college students is associated with clinical adjustment outcomes such as depression and alcohol consumption. This study also aims to examine whether reactivity in the two branches of the autonomic nervous system (sympathetic and parasympathetic) jointly moderate the relationship between cyberbullying and depression/alcohol consumption, indicating sensitivity to the environment. Participants (n =164, 69% female, M age = 19.92, SD = …

Shaping Soil: Examining Relationships Between Agriculture And Climate Change, Lindsay Barbieri

Graduate College Dissertations and Theses

As the ripple-effects of a changing climate shape our planet, understanding relationships between agriculture and climate change is critical. With agricultural practices shaping soils on over a third of the earth’s land surface, the soils and lands where food is produced are integral grounds for examining these relationships. While not all humans practice agriculture in similar or damaging ways, nevertheless, dominant agricultural practices are displacing beings and ecosystems and perturbing global nutrient cycles across the planet. These entwined imbalances of dominance and nutrients result in flows of excess nitrogen, phosphorus, and carbon that are responsible for nearly three-fourths of the …

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 …

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 …

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 …

Much Needed Studies Of The Three Players Of Chagas Disease In Central America: Vertebrate Blood Meal Sources And Ecohealth, A New Vector Species Description, And Key Phylogenetic Analysis Of The Trypanosome Parasite., Raquel Asuncion Lima Cordon

Graduate College Dissertations and Theses

The protozoan parasite Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae) is the etiological agent of Chagas disease, reported by the World Health Organization (WHO) as responsible for over 10,000 deaths in 2015. Chagas disease is considered a Neglected Tropical Disease by the WHO, this designation highlights the challenges to overcoming the disease as it afflicts the most vulnerable populations, mainly the rural poor in Latin America. Understanding T. cruzi transmission dynamics is particularly difficult because it can be vectored by over 150 species of Triatominae insects, and all mammal species are potential hosts. Thus, results from one locale may not be generalizable to …

Effects Of Changing Winter Severity On Plankton Ecology In Temperate Lakes, Allison Rose Hrycik

Graduate College Dissertations and Theses

Climate change has rapidly altered winter conditions in temperate regions of the globe. Over the last several decades, snowpack has decreased, spring snowmelt is earlier, and ice cover has declined. Associated changes in lake mixing, inflow, nutrient cycling, and light transmission during winter can affect lake biota both under ice and into the open-water season. Unfortunately, under-ice lake research is limited compared to open-water research. Recent winter limnology research, however, suggests that ecosystem processes do not stop under ice, and many questions remain about the drivers of phytoplankton and zooplankton dynamics in winter. My research aimed to uncover mechanisms by …

Climate Responses Of Red Spruce (Picea Rubens Sarg.) And Its Associated Forest Community Along Elevational Gradients In The Northeastern United States., Brittany Verrico

Graduate College Dissertations and Theses

The composition of forest communities and the distributions of individual tree species are both strongly tied to climatic conditions through species-specific physiological tolerances to the abiotic environment. As a result, spatial and temporal variation in climate, both natural and anthropogenically induced, exert strong influence on tree species distributions and their adaptations to local conditions. In order for trees, which are sessile, to persist in a rapidly changing environment, genetic variation and/or phenotypic plasticity must be maintained to facilitate adaptive evolution. While strong local adaptation to current climate has been reported for trees sampled across broad spatial landscapes (e.g., latitude), few …

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 …

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, …

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 …

The Role Of Infralimbic Cortex In Switching Between An Instrumental Behavior’S Status As A Goal-Directed Action Or Habit, Matthew Broomer

Graduate College Dissertations and Theses

In instrumental learning, extensive training of a response typically generates a habit. The transition from goal-directed to habitual behavioral control is often considered unidirectional; however, recent evidence suggests this is not the case. Under certain conditions, goal-directed control may be restored to a behavior that was previously habitual. We identify the infralimbic cortex (IL) as a participant in this process and draw on both instrumental learning and fear extinction literatures to further our understanding of IL function.

Four experiments explored the role of IL in flexible behavior. Experiments 1a and 1b were instrumental learning experiments. Experiment 1a used a previously …

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 Role Of Bdnf-Mediated Neuroplasticity In Cardiovascular Regulation Within The Hypothalamus And Brainstem, Daniella Johanna Thorsdottir

Graduate College Dissertations and Theses

The paraventricular nucleus of the hypothalamus (PVN) is an important cardiovascular and autonomic regulatory center. Activation of PVN neurons projecting to the brainstem and spinal cord elevates sympathetic activity and blood pressure. Brain derived neurotrophic factor (BDNF) plays a key role in stress-induced cardiovascular responses within the PVN and is also known to be upregulated in the PVN in response to stress and hyperosmolality. PVN overexpression or acute injection of BDNF also elevates blood pressure chronically. However, the mechanism behind BDNF-mediated cardiovascular regulation is not fully understood. BDNF is known to modulate excitatory/inhibitory signaling by altering the expression and membrane …

Brain-Behavior Connections Underlying Emotion And Theory Of Mind In Autism Spectrum Disorder, Yu Han

Graduate College Dissertations and Theses

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder that af- fects nearly 1 in 54 children. Children with ASD struggle with social, communication, and behavioral challenges due to deficits in theory of mind (ToM). In addition, diag- nosis of ASD is complicated and there is an urgent need to identify ASD-associated biomarkers and features to help automate diagnostics and develop predictive ASD models. In this study, we conducted two experiments collecting behavioral and neu- roimaging data from 9 children with ASD and 19 neurotypical children (NT) between the age of 7 and 14 years.

The first experiment examined specific …

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 …

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 …

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 …

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 Sex Differences In Habit Formation: Effects Of Methamphetamine Sensitization And Contributions Of Ovarian Hormones, Hannah Schoenberg Book

Graduate College Dissertations and Theses

In the early stages of instrumental learning, behavior is goal-directed and sensitive to changes in the value of the instrumental outcome. As learning progresses, an association forms between the response and stimuli within the learning environment, such that after sufficient repetition, responding is evoked automatically in the presence of these stimuli and is insensitive to changes in outcome value. The reflexive nature of these types of behaviors has led to their classification as instrumental habits. The emergence of habitual behavior is thought to involve parallel processes that are mediated by distinct neural substrates. Regions of the prefrontal cortex, amygdala, and …

The Effects Of Dietary Yeast Extracts On Rumen Microbiota And Fermentation In A Dual-Flow Continuous Culture Fermentation System, Lauren Baker

Graduate College Dissertations and Theses

Dietary yeast supplements are a popular feed additive in ruminant diets as its inclusion can favorably alter the rumen microbiota and fermentation, and subsequently improve animal health and production. Yeast are a rich source of amino acids, peptides, organic acids, carbohydrates, lipids, vitamins, and minerals. Inclusion of nutrient-rich yeast and yeast extracts in the diet promote the growth of select groups of rumen microbiota, subsequently improving digestibility, volatile fatty acids, and pH profile. However, the large variability within yeast types and composition has created inconsistent results on these parameters, and further investigation into yeast product variability is crucial for understanding …

Analysis Of Host Factors Involved In Regulating Hiv-1-Induced Syncytium Formation, Emily Elizabeth Whitaker

Graduate College Dissertations and Theses

Human Immunodeficiency Virus type 1 (HIV-1) is a retrovirus and the causative agent of Acquired Immunodeficiency Syndrome (AIDS). HIV-1 can spread through multiple modes of transmission including cell-to-cell transmission between CD4+ T cells at a transient junction known as the virological synapse (VS). The VS forms upon HIV-1 Envelope (Env) on the surface of an infected (producer) cell binding CD4 on an uninfected (target) cell. While the VS typically resolves with complete cell separation and transfer of virus particles, Env can occasionally facilitate cell-cell fusion at this site, forming a multinucleated infected cell (syncytium). Excessive syncytium formation is prevented by …

Microevolution In Staphylococcus Aureus: Does Exposure To Sub-Lethal Levels Of Cinnamon Bark Oil Lead To Changes In Antimicrobial Susceptibility?, Heather Sandra Schuettner

Graduate College Dissertations and Theses

The emergence of antibiotic-resistant and multi-drug resistant bacteria presents a growing global health issue recognized by the World Health Organization and the Centers for Disease Control and Prevention. Infections caused by drug-resistant bacteria are associated with longer hospital stays, higher treatments costs, and increased mortality compared to infections caused by antibiotic-susceptible pathogens. The global increase in antibiotic resistance is driven in part by the misuse and overuse of antibiotics in healthcare and agriculture. Staphylococcus aureus can infect humans and animals, and strains that are resistant to one or more antibiotics are common. Many plant essential oils have antimicrobial properties. Essential …

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 …

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 …

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 …

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. …

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. …

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 …