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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 …

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 …

The Maintenance Of Genomic Stability: Impacts Of The Loss Of Kif18a, Leslie Anne Sepaniac

Graduate College Dissertations and Theses

Regulated and repeated cell division is necessary for the development, growth, and reproduction of multicellular organisms. A central purpose of mitosis is to faithfully pass hereditary information from one cell onto two genetically identical daughter cells, thus maintaining genomic stability. Cells employ several mechanisms for maintaining genomic stability, including well-characterized cell cycle checkpoints. However, chromosome segregation errors can occur in spite of these regulatory mechanisms. Such errors can result in an improper number of chromosomes being distributed to daughter cells – termed aneuploidy – or improper localization of chromosomes into separate satellite nuclei – termed micronuclei. What, if any, additional …

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 …

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 …

Assessing Chemical And Biological Recovery From Acid Rain Deposition In Montane Vermont Lakes, Sydney Diamond

Graduate College Dissertations and Theses

Vermont’s inland lakes are changing rapidly in response to anthropogenic disturbance pressures. While changes in water chemistry are well documented across the state, the biological response of primary producer communities to these shifts remains poorly understood. This project investigated the response of phytoplankton communities to the interacting effects of recovery from acidification and climate change in high-altitude lakes. We analyzed long-term monitoring and meteorological data in four of Vermont’s acid-impaired lakes and found that as pH and acid-neutralizing capacity has increased, so have concentrations of dissolved organic carbon (DOC) in most lakes. To assess the biological response to these processes, …

The Role Of Higher Education In Intergenerational Mobility, Amanda Davis Simpfenderfer

Graduate College Dissertations and Theses

Within the US, higher education is viewed as a stepping stone to economic and social mobility, where the promise of improved socioeconomic outcomes continues to draw many students to enroll despite the increasing cost of attendance (National Center for Education Statistics, 2019). The implicit (and sometimes even explicit) promise is that a post-secondary degree is a pathway to upward mobility for all individuals. Yet, higher education is not a monolith, nor are the students attending a homogenous population. Students experience differential outcomes based on their demographics (Baum et al., 2013), as well as institutional type (Thompson, 2019). The purpose of …

Mutations In Ikaros Lead To An Altered Epigenetic And Chromatin Landscape Contributing To The Manifestation Of B-Cell Related Disorders, Princess Rodriguez

Graduate College Dissertations and Theses

IKAROS is expressed throughout the entire hematopoietic system and is required for lymphoid commitment and subsequent differentiation towards the B-lymphoid fate. If absent, progenitor and mature B-cell subsets are not expressed. IKAROS (encoded by IKZF1) is a zinc-finger transcription factor shown to regulate gene expression either directly or through the recruitment of chromatin remodeling complexes. The epigenetic gene regulatory mechanisms, including the posttranslational modification to histone proteins, as well as the expression of noncoding RNAs (ncRNAs) are important to control as perturbations in these processes contribute to the manifestation of human diseases. If left unregulated, uncontrolled growth, aberrant cell activation, …

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 …

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 …

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 = …

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 …

Transcriptional Programming By Thyroid Hormone Receptor Beta Maintains Normal Cell Identity And Suppresses Tumor Growth, Noelle Elizabeth Gillis

Graduate College Dissertations and Theses

The overall incidence of thyroid cancer has more than tripled over the past several decades, as has aggressive disease and mortality. The direct relationship between thyroid disease, thyroid hormone levels, and development of thyroid cancer is incomplete. Recent meta-analyses have indicated a higher risk of thyroid cancer for patients with thyroid diseases that reflect an altered thyroid-pituitary signaling axis, which can have profound impacts on the physiology of the thyroid gland. These largely unanswered questions regarding altered thyroid hormone signaling and its consequences for thyroid tumor growth present a significant clinical challenge. This dilemma may come from a lack of …

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 …

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 …

Network And Ecological Methods To Study Enteric Pathogen Co-Infections, Connor L. Klopfer

Graduate College Dissertations and Theses

Diarrhea remains a leading cause of childhood morbidity and mortality, especially inchildren under 5 years of age. Enteric pathogen co-infection has been found to cause increased diarrheal severity and some pathogens may work in tandem to enhance infection. It is important to identify patterns of pathogen co-infection and their impact on diarrhea to inform intervention strategies for improving child health. In this thesis, I use data from the MAL-ED and PROVIDE birth cohort studies in Bangladesh to generate bipartite networks that represent the relationship between stool samples and pathogens. I randomly rewire the network while preserving connectivity to randomize the …

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 …