Life Sciences Commons^™

A Novel Approach For The Identification Of Cytoskeletal And Adhesion A-Kinase Anchoring Proteins, Laura Taylor Director

Graduate College Dissertations and Theses

A-kinase anchoring proteins (AKAPs) are signaling scaffolds which provide spatial and temporal organization of signaling pathways in discrete subcellular compartments. Through tethering the cyclic-AMP dependent protein kinase A (PKA), AKAPs target PKA activity to distinct regions in the cell, bringing PKA in close proximity to its target proteins. This provides a high level of specificity and regulation of PKA and its role in mediating a number of biological processes, one of which is cell migration. Cell migration is a highly dynamic and fundamental process, when misregulated can lead to a number of pathologies. The process of cell migration requires integration …

Shade Coffee: Update On A Disappearing Refuge For Biodiversity, Shalene Jha, Christopher M. Bacon, Stacy M. Philpott, V. Ernesto Méndez, Peter Läderach, Robert A. Rice

College of Agriculture and Life Sciences Faculty Publications

In the past three decades, coffee cultivation has gained widespread attention for its crucial role in supporting local and global biodiversity. In this synthetic Overview, we present newly gathered data that summarize how global patterns in coffee distribution and shade vegetation have changed and discuss implications for biodiversity, ecosystem services, and livelihoods. Although overall cultivated coffee area has decreased by 8% since 1990, coffee production and agricultural intensification have increased in many places and shifted globally, with production expanding in Asia while contracting in Africa. Ecosystem services such as pollination, pest control, climate regulation, and nutrient sequestration are generally greater …

Extension 3.0: Managing Agricultural Knowledge Systems In The Network Age, Mark Lubell, Meredith T. Niles, Matthew Hoffman

College of Agriculture and Life Sciences Faculty Publications

This paper develops the idea of “Extension 3.0” as an approach to agricultural extension that capitalizes on the network structure of local agricultural knowledge systems. Over the last century, agricultural knowledge systems have evolved into networks of widely distributed actors with a diversity of specializations and expertise. Agricultural extension programs need to manage these networks in ways that maximize the synergy between experiential, technical, and social learning. Using empirical research from California farmers, we highlight the structure of these networks within and across contexts, and the importance of boundary-spanning relationships. We provide some initial recommendations about actions needed to realize …

Estrogen Receptor Beta Is A Negative Regulator Of Mammary Cell Proliferation, Xiaozheng Song

Graduate College Dissertations and Theses

The mammary gland cell growth and differentiation are under the control of both systemic hormones and locally produced growth factors. Among all these important hormones and growth factors, estrogen plays a central role in mammary gland development. The biological function of estrogen is mediated by estrogen receptor α (ERα) and estrogen receptor β (ERβ). Both ERα and ERβ are expressed in the mammary gland, but with distinct expression patterns. In the mammary gland, ERα has been proved to be the estrogen receptor that mediates the mitogenic function of estrogen. However the function of ERβ in mammary cell proliferation is less …

Farmer Adoption Of Best Management Practices Using Incentivized Conservation Programs, Jennifer Christine Miller

Graduate College Dissertations and Theses

Many farms in the United States impose negative externalities on society. Population growth and the accompanying increase in demand for food further promote this trend of environmental degradation as a by-product of food production. The USDA's Environmental Quality Incentives Program (EQIP) provides financial assistance to farmers who wish to address natural resource concerns by making structural improvements or implementing best management practices (BMPs) on their farms. Regional examinations of program implementation and incentive levels are needed to evaluate the effectiveness of EQIP at both the farm and environmental level. This research addresses this need in the following two ways. First, …

Improved Recovery And Rapid Identification Of Strains, Mixed Strains, Mixed Species, And Various Physiological States Of Foodborne Pathogens Using Infrared Spectroscopy, Esmond Boafo Nyarko

Graduate College Dissertations and Theses

Challenges encountered in pathogen identification and detection include the genetic heterogeneity of strains within species of some foodborne pathogens, isolation of injured cells, mixed strains or mixed species contamination of foods, and differentiation between viable and dead cells. The first objective of this research was to evaluate an isolation medium that was based on time-delayed release (5 to 6 h) of selective agents in tablet format to a modified Listeria recovery enrichment broth (mLRB) medium for enhanced and rapid recovery of injured Listeria. The second objective involved the use of Fourier transform infrared (FT-IR) spectroscopy and chemometric analysis for the …

The Effectiveness Of An Online, Interactive, College Course In Energy Balance, Designed From A Framework Of Behavioral Theories, Simonne Marie Eisenhardt

Graduate College Dissertations and Theses

During late adolescence and the transition to college, students often experience weight increases and significant lifestyle changes including the adoption of unhealthy eating habits and decreased physical activity levels. To address this concern, a science-based, interactive course, designed from a framework of behavioral theories was developed to target improvements in energy balance knowledge and determinants of dietary and physical activity behaviors. The objective of this study was to assess the effectiveness of this course using a comparison group pre-test/post-test design. Thirty-three undergraduate students, ages 18-25, participated in the course, while twenty-six students served as controls. Paired samples t-tests compared pre- …

Role Of Heme Oxygenase In Modulating Expression Of Ros-Regulatory Enzymes In Medicago Truncatula, Parna Ghosh

Graduate College Dissertations and Theses

Heme Oxygenase (HO) is an enzyme universally found in animals, plants and microbes. In plants, the role of heme oxygenase in the synthesis of the phytochrome chromophore is well recognized and has been extensively studied; however its role in regulating reactive oxygen species (ROS) in plants is just beginning to be explored, particularly in legumes. Legumes interact with Rhizobium bacteria to form symbiotic nitrogen fixing nodules. ROS plays an important role in the development of roots as well as symbiotic nodules. In the model legume Medicago truncatula, ROS in the root is regulated in part by the LATD/NIP gene. …

Diversification Activities Of Vermont Dairy Farmers: A Study Of Raw Milk And Local Beef Processing In The State., Ryan Leamy

Graduate College Dissertations and Theses

The vast majority of earned agricultural dollars in Vermont come from the dairy industry, but with volatility in the market in recent years, including rising costs of feed and the fluctuating price of milk, state officials have begun to recommend diversification of farm activities to instill resiliency into the system. The research presented in this thesis explores two avenues for diversification, farm-to-consumer sales of raw milk and local beef production.

The second chapter utilizes diffusion theory to understand the prevalence of raw milk consumption in Vermont, develop a profile of the raw milk consumer, document the motivations of raw milk …

Local Mate Competition And The Sex Ratios Of Malaria Parasites, With A Focus On Plasmodium Mexicanum, Allison T. Neal

Graduate College Dissertations and Theses

Sex ratio theory is a focus in evolutionary biology that explores how natural selection shapes investment in males and females. It has provided some of the best quantitative evidence of evolution and could find utility in public health efforts through its application to malaria parasites. These parasites have distinct male and female forms that are produced following massive asexual replication, and they mate within the blood-feeding insects that transmit them between vertebrate hosts. A very similar population structure is assumed by local mate competition (LMC), a model from sex ratio theory that predicts female-biased sex ratios dependent on the degree …

The Impacts Of Multiple Anthropogenic Disturbances On The Montane Forests Of The Green Mountains, Vermont, Usa, Carolyn Ann Pucko

Graduate College Dissertations and Theses

How and why species’ ranges shift has long been a focus of ecology but is now becoming increasingly important given the current rate of climatic and environmental change. In response to global warming, species will need to migrate northward or upward to stay within their climatic tolerances. The ability of species to migrate will determine their fate and affect the community compositions of the future. However, to more accurately predict the future extent of species, we must identify and understand their responses to past and current climatic and environmental changes. The first place change is expected to occur is within …

Functional Properties Of Whey Protein And Its Application In Nanocomposite Materials And Functional Foods, Helen Walsh

Graduate College Dissertations and Theses

Whey is a byproduct of cheese making; whey proteins are globular proteins which can be modified and polymerized to add functional benefits, these benefits can be both nutritional and structural in foods. Modified proteins can be used in non-foods, being of particular interest in polymer films and coatings. Food packaging materials, including plastics, can linings, interior coatings of paper containers, and beverage cap sealing materials, are generally made of synthetic petroleum based compounds. These synthetic materials may pose a potential human health risk due to presence of certain chemicals such as Bisphenol A (BPA). They also add to environmental pollution, …

Modeling Consumption Rates Of Atlantic Herring (Clupea Harengus), Mitchell Jones

Graduate College Dissertations and Theses

Pelagic forage fishes play critical roles in productive marine food webs by providing a link between zooplankton and piscivores and transferring energy from feeding grounds to other ecosystems. The amount of energy moved to higher trophic levels or new systems is directly linked to the consumption rate of pelagic forage fishes. In the Gulf of Maine, Atlantic herring (Clupea harengus) is the dominant forage fish; the purpose of this study is to determine their specific consumption rate (g prey/g fish/day). Using fish collected in autumn 2012 and spring 2013, we applied a mercury mass-balance model to estimate individual …

Regulation Of Β-Casein Gene Expression By Octamer Transcription Factors And Utilization Of Β-Casein Gene Promoter To Produce Recombinant Human Proinsulin In The Transgenic Milk, Xi Qian

Graduate College Dissertations and Theses

β-Casein is a major milk protein, which is synthesized in mammary alveolar secretory epithelial cells (MECs) upon the stimulation of lactogenic hormones, mainly prolactin and glucocorticoids (HP). Previous studies revealed that the proximal promoter (-258 bp to +7 bp) of the β-casein gene is sufficient for induction of the promoter activity by HP. This proximal region contains the binding sites for the signal transducer and activator of transcription 5 (STAT5), glucocorticoid receptor (GR), and octamer transcription factors (Oct). STAT5 and GR are essential downstream mediators of prolactin and glucocorticoid signaling, respectively. This study investigated the functions of Oct-1 and Oct-2 …

Understanding And Improving Microbial Biofuel Tolerance As A Result Of Efflux Pump Expression Through Genetic Engineering And Mathematical Modeling, William James Turner

Graduate College Dissertations and Theses

Recent advances in synthetic biology have enabled the construction of non-native metabolic pathways for production of next-generation biofuels in microbes. One such biofuel is the jet-fuel precursor α-pinene, which can be processed into high-energy pinene dimers. However, accumulation of toxic biofuels in the growth medium limits the possible fuel yield. Overexpression of transporter proteins such as efflux pumps can increase tolerance to biofuels by pumping them out of the cell, thus improving fuel yields. However, too many efflux pumps can compromise the cell as well, creating a trade-off between biofuel toxicity and pump toxicity. In this work we improve the …

Trophic Dynamics And Cyanobacteria Blooms In Shallow Eutrophic Bays Of Lake Champlain, Rebecca Michelle Gorney

Graduate College Dissertations and Theses

This study was conducted to evaluate the relative roles of trophic dynamics and nutrient concentrations in the development of cyanobacteria blooms. The motivation for this research was to gain insights into how food webs respond to ecosystem-scale changes, using Lake Champlain as a case study. I sought to link field-based observations with experimentally derived data on mechanisms to better understand the processes that drive cyanobacteria blooms. My research addressed three specific topics: (1) associations among phytoplankton and nutrient concentration trends over time, (2) the impacts of planktivory by invasive fish on the ambient zooplankton community, and (3) the role of …

Determining The Role Of The Ergic-53 Cargo Receptor Complex In Arenavirus Propagation, Joseph P. Klaus

Graduate College Dissertations and Theses

Arenaviruses and hantaviruses are human pathogens that cause significant morbidity and mortality. The current lack of vaccines and treatment options for these viruses is a global concern. Despite producing only 4 proteins, these viruses are able to maintain a persistent and asymptomatic infection in wild rodents while being continuously shed into the environment. In humans, these viruses cause a spectrum of diseases ranging from aseptic meningitis to severe hemorrhagic fever syndromes. Little is known about how arenavirus and hantavirus proteins engage and interact with the human proteome during the complex process of viral biogenesis, or how the interactions with human …

Helicase-Ssb Interactions In Recombination-Dependent Dna Repair And Replication, Christian Jordan

Graduate College Dissertations and Theses

Dda, one of three helicases encoded by bacteriophage T4, has been well- characterized biochemically but its biological role remains unclear. It is thought to be involved in origin-dependent replication, recombination-dependent replication, anti- recombination, recombination repair, as well as in replication fork progression past template-bound nucleosomes and RNA polymerase. One of the proteins that most strongly interacts with Dda, Gp32, is the only single-stranded DNA binding protein (SSB) encoded by T4, is essential for DNA replication, recombination, and repair.

Previous studies have shown that Gp32 is essential for Dda stimulation of replication fork progression. Our studies show that interactions between Dda …

Mitochondrial Structure And Function As A Therapeutic Target In Malignant Mesothelioma, Brian Cunniff

Graduate College Dissertations and Theses

Malignant mesothelioma (MM) is a rare tumor associated with occupational exposure to asbestos with no effective treatment regime. Evaluation of mitochondrial function in human MM cell lines revealed a common tumor phenotype: in comparison to immortalized or primary human mesothelial cells, MM tumor cells displayed a more oxidized mitochondrial environment, increased expression of mitochondrial antioxidant enzymes, and altered mitochondrial metabolism. Earlier work by our laboratory indicated that increases in mitochondrial reactive oxygen species (mROS) in MM cell lines supports expression of FOXM1, an oncogenic transcription factor that contributes to increased cell proliferation and chemoresistance. These studies sought to investigate targeting …

Molecular Characterization Of Purβ: A Purine-Rich Single-Stranded Dna-Binding Repressor Of Myofibroblast Differentiation, Amy Rumora

Graduate College Dissertations and Theses

The trans-differentiation of injury-activated fibroblasts to myofibroblasts is a process that provides contractile strength for wound closure. Persistent myofibroblast differentiation, however, is associated with fibrotic pathologies such as organ fibrosis, vascular remodeling, and atherosclerotic plaque formation. Myofibroblasts acquire a contractile phenotype with biochemical properties characteristic of both smooth muscle cells and stromal fibroblasts. The cyto-contractile protein, smooth muscle α-actin (SMαA) is a biomarker of myofibroblast differentiation. Expression of the SMαA gene, ACTA2, is regulated by cis-acting elements and transcription factors that activate or repress the ACTA2 promoter.

Purine-rich element binding proteins A (Purα) and B (Purβ) are sequence-specific, …

Exploring The Nature Of Crystals In Cheese Through X-Ray Diffraction, Gil Fils Tansman

Graduate College Dissertations and Theses

The optimization of powder x-ray diffraction (PXRD) for the study of cheese crystals was the focus of this study. A survey was conducted of various manifestations of calcium lactate crystals on the rindless surface and within mechanical openings of Cheddar cheese using PXRD. The diffraction reference card database contained a card that was entitled calcium lactate pentahydrate and corresponded to some of the crystalline material found on the cheeses. Diffractions patterns generated from other samples of crystalline material revealed the existence of an unknown crystal that resembled and behaved similarly to calcium lactate pentahydrate, but did not match the reference …

Investigations Into Host-Specific Interactions And Local Adaptation In The Mycorrhizal Symbiosis, Jonathan Gonzalez

Graduate College Dissertations and Theses

Mycorrhizal fungi are soil-borne organisms that form symbiotic associations with the majority of land plants. These fungi gather and exchange mineral nutrients with plants for photosynthetically derived carbohydrates. Mycorrhizal fungi can also confer other benefits onto plants, e.g. defense against pathogens, improved water relations, tolerance to heavy metal toxicity and herbivory. The influence of mycorrhizal fungi on plant mineral nutrition and response to stress suggests that these organisms may have a role to play sustainable agriculture as well as in bioremediation and ecosystem restoration.

In contributing to this important research, I investigated host-specific interactions between mycorrhizal fungi and the sex …