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    Organic Fouling Mitigation In Forward Osmosis Technology Through The Use Of Oscilatting Alternating Current Electric Fields

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    Forward osmosis (FO) is the term given to osmosis in water filtration applications. FO has many advantages to conventional membrane filtration processes. The lack of external pressure needed to force solvent through the membrane is dramatically decreased in FO, resulting in a lower cost of operation compared to reverse osmosis. Lower external pressures also result in decreased fouling on the membrane surface and improved permeate flux. Fouling is one of the foremost challenges within the membrane filtration industry and is one of the biggest contributors to operating costs. While FO results in less fouling than RO, fouling remains a major concern and results in significant expenses to operate FO. Many techniques exist to combat fouling, such as back washing, flushing, and chemical cleaning, however these techniques can be cost intensive and harmful to membrane integrity and performance. As a result, there is great interest in less intrusive cleaning techniques such as acoustic cleaning or electric fields that can be applied to mitigate fouling without compromising the membrane. Electric cleaning has shown great promise as an in-situ cleaning method, offering increased performance in membrane flux.Electric field membrane cleaning involves applying an electric field perpendicular to the membrane surface, resulting in the movement of charged particles towards the electrodes at either side of the filtration channel, reducing the occurrence of fouling. Most electric field membrane cleaning techniques use a direct current (DC) electric field to cause this motion, called electroosmosis. DC cleaning has various drawbacks, such as electrolysis at the electrodes, corrosion of the electrodes, and further damage to the membrane surface which hinders DC cleaning performance. There is currently limited literature involving the use of alternating current (AC) fields for membrane cleaning. The aim of this study was to examine the feasibility of AC fields as an in-situ cleaning technique in FO application. Flux performance was assessed using bovine serum albumin (BSA) and sodium alginate as model foulants. Flux was measured over a 6 to 8-hour filtration period using a pulsed AC field applied every 2-hours, and a continuous AC field applied over the duration of filtration. Sodium chloride was used as a draw agent. Results from these experiments indicate that AC electric fields are an effective method for in-situ organic fouling mitigation in FO process. Continuous and pulsed fields of various frequencies, conducted with foulant material in the feed solution, have demonstrated to improve flux retention to levels comparable to clean water flux conditions with no foulants. Normalized flux in the presence of foulants was raised from as low as 40% of initial flux at the conclusion of the trial to as high as 90% of initial flux with the application of electric field. Pulsed AC field application appeared to be more effective than continuous field, both in terms of fouling mitigation and lower energy input requiremen

    An Agroecological Approach To Improving Soil Health Practices On Vermont Vegetable Farms

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    Vermont’s vegetable farms are highly valued for their contributions to the state\u27s food system, environment, and communities, yet their continued success is impeded by many challenges. Specifically, soil is a valued and vulnerable resource, but management of it requires knowledge, money, and time. This dissertation applies an agroecological approach to understanding soil health practices on vegetable farms in three distinct studies. In the first part of this dissertation, data is collected from six on-farm research trials in 2017-2018 to better understand the nitrogen (N) dynamics following two commonly planted legume-grass cover crop mixes: field peas (Pisum sativum, var. ‘4010’) and oats (Avena sativa, var. ‘Kayouga’), seeded in spring; hairy vetch (Vicia villosa) and winter rye (Secale cereale) seeded in autumn. Understanding the timing and quantity of available N from legume cover crops promises to help growers produce on-farm fertility while reducing inputs of phosphorus-based fertilizers, the overuse of which can harm water quality. The results of this project demonstrate the context specific nature of nutrient dynamics and associated challenges of predicting soil N availability. The next chapter focuses on a participatory research project to better understand yield outcomes related to newly revised high tunnel tomato nutrient recommendations. This project collected data from 46 farms in Maine, Massachusetts, New York, and Vermont in 2020-2021, revealing that the new recommendations led to predictably better yields, but that on farm practices had a significant impact. In the final chapter, co-created mental models were used to better understand opportunities and barriers to soil health practice implementation. This project analyzed data from 12 vegetable farmer interviews conducted in spring 2022. The findings revealed that growers were enabled by knowledge, innovation, and peer to peer support, while they were limited by money, land, equipment, and time. This chapter suggests adapting mental models for future Extension and outreach work. This dissertation highlights the range of soil health practices on Vermont vegetable farms and the associated diversity in metrics and outcomes. Farmers will best be served in the future with support and resources that account for each farm’s unique context

    Trauma And Resilience Mechanisms During Political Violence: Survivors Of The 2021 Military Coup In Myanmar

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    According to the United Nations (2023), global armed conflicts and violence are rising, the highest on record since World War II. In the context of political violence, how can we understand trauma reactions and resilience through a culturally-sensitive lens? The current study addressed this question by examining Myanmar trauma survivors of the 2021 coup d’etat. We followed the World Health Organization (WHO)’s forward-backward translation guidelines in designing this mixed-methods study and established community-based partnerships for sample recruitment in Myanmar (Robine & Jagger, 2003). The existing literature demonstrates a strong relationship between the degree of exposure to political violence and the likelihood of developing psychopathology including post-traumatic stress disorder (PTSD), anxiety, depression, and alcohol use (Al-Krenawi & Graham, 2012; Braun-Lewensohn et al., 2009). While political violence increases the risk of mental health problems, research also suggests that survivors exhibit remarkable resilience amid humanitarian crises (Jordans et al., 2007; Pedersen, 2002; Pettigrew, 2004). In this research, we examined trauma as well as resilience mechanisms through a clinical framework (using gold-standard quantitative psychological questionnaires) and a sociocultural lens applied to qualitative data (i.e.., a hybrid deductive and inductive analysis of open-ended responses). Our analyses explored gender differences in psychological symptoms, illustrated the dose-response relationship between trauma and psychopathology, and highlighted the moderating role of resilience in the significant association of PTSD and alcohol use. Findings showed that women participants reported greater internalizing symptoms (PTSD, depression, and anxiety) while men reported greater alcohol use. Alongside these expressions, we observed a significant dose-response relationship of trauma and psychopathology: greater trauma correlated with stronger PTSD (r[178] = .37, p \u3c .001) and increased alcohol use (r[178] = .22, p \u3c .001). Higher PTSD also predicted more pronounced comorbidity with depression, anxiety, and alcohol use (r[178] = .45, .36, .24, p \u3c .001).The interaction term between PTSD symptoms and resilience in predicting alcohol use was significant, B = –0.16, SE = 0.07, t(169) = –2.48, p = .013, suggesting that as resilience increased, the relationship between PTSD symptoms and alcohol use weakened. We also identified Myanmar participants’ unique cultural expressions of distress regarding trauma reactions (e.g., “burning rage”) and contextually meaningful sources of resilience (e.g., “political commitment”). Both psychological and cultural considerations were included to highlight clinical, research, and policy implications of studying underserved global communities, such as Myanmar survivors

    Expanding Awareness of TBI Resources in the North Country

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    Disability, emotional dysregulation and financial stress are only some of the issues that many patients who suffer TBI encounter. While resources are available to alleviate some of these burdens on patients who suffer TBI in New York\u27s North Country, patients often struggle to find these resources. This project endeavors to create a resource for patients, family members and practitioners to find available resources.

    High-Plex Imaging Of Rnas And Proteins For Spatial Profiling Of The Breast Cancer Tumor Microenvironment

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    Breast cancer is the most common cancer in women in the United States and is thesecond highest cause of cancer death in women. The rise in available screening techniques over the years has led to earlier detection of breast cancer, which has in turn allowed for more effective treatments and better prognoses. However, there is unintended harm associated with increased screening. There have been increased numbers of ductal carcinoma in situ (DCIS) which is a non-obligate precursor of invasive breast cancer. Currently there is no reliable method to predict which DCIS cases will progress to invasive breast cancer. It is critical to identify factors that predict progression and recurrence to make sure patients receive appropriate treatment. The tumor microenvironment has been suggested as playing a role in DCIS progression and recurrence. Gene profiling has identified changes that occur in the microenvironment during progression. In the past, it has been difficult to understand how cells within the microenvironment are interacting with the tumor cells because of technological limitations. With the increase in high-throughput “spatial-omics” technologies, it is now possible to phenotype cells and understand how they are spatially interacting with the tumor. The goal of this study is to spatially profile the microenvironment around normal/benign breast, DCIS, and invasive breast cancer samples to identify potential biomarkers of progression and recurrence. Archival specimens from several different groups of patient samples were stained with multiplex fluorescence in situ hybridization (FISH) and high-plex immunofluorescence panels and analyzed to identify different types of cells within the epithelium and stroma and how they were spatially located with respect to the tumor. We identified myoepithelial continuity within the ducts as one of the features that may influence progression of the disease. Cells within stromal microenvironment that are either expressing transcription factors (RUNX1), long non-coding RNA (MANCR), chemokine receptors and ligands (CXCR6, CXCL12), mesenchymal stromal cell marker (CD90), and myoepithelial marker (TP63) were associated with various clinical factors including grade, HER2 status, hormone receptor status, differentiation, type of DCIS, and lymphatic vascular invasion. Future studies to confirm the importance of myoepithelial continuity measurement to predict recurrence and whole transcriptome analyses to correlate RNA with markers phenotyping the cells will provide a better understanding of how the tumor microenvironment functions in breast cancer progression and recurrence

    Selection For Insecticide Tolerance Alters Phenotypic, Transcriptomic, And Epigenetic Responses To Multiple Stressors In The Colorado Potato Beetle.

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    In contemporary agroecosystems, insect pests encounter numerous stressors arising from both natural factors and human activities. One prevalent stressor is the repeated exposure to pesticides, which could prepare insects to endure further challenges posed by insecticides or high temperatures. Existing research suggests that the effects of multiple stressors on insect performance can be either positive or negative. However, it remains uncertain how repeated pesticide exposure affects how insects respond at both the phenotypic and genomic levels when confronted with subsequent stressors. In this dissertation, we investigate whether selection for pesticide tolerance influences phenotypic, transcriptomic, and epigenomic responses to multiple stressors in the Colorado potato beetle (CPB), Leptinotarsa decemlineata. First, we examine how selection influences phenotypic responses to imidacloprid and high-temperature stress, both individually and in combination. By subjecting beetles to nine generations of selection for imidacloprid tolerance, we compared how selected beetles responded to imidacloprid exposure and high-temperature stress against unselected beetles. Given that behavior is a sensitive indicator of stress responses, we assessed the effects of single and combined exposure to imidacloprid and high temperatures on larval mobility and herbivory. Additionally, we monitored long-term effects, including mortality over time, development time, and female fecundity. Next, we investigate how selection influences transcriptomic responses to single and combined imidacloprid and high-temperature stress. Specifically, we focused on identifying differentially expressed genes associated with xenobiotic and thermal tolerance, as well as cellular stress defenses. This analysis allowed us to discern whether selected and unselected beetles employ distinct strategies to cope with single and combined stressors. Lastly, we examine how selection impacts DNA methylation patterns in response to single and combined imidacloprid and high-temperature stress in both selected and unselected beetles. We identified differentially methylated sites within stress-related genes across all treatments compared to control groups in both beetle groups. By comparing differentially methylated genes to our previous transcriptomic data, we revealed the potential role of DNA methylation in promoting the transcription of stress-related genes. Collectively, our study provides a comprehensive perspective on how the selection for insecticide tolerance shapes responses to multiple stressors in a highly resilient insect pest

    The Population Genetics Of Four Ant Species In A Fragmented Urban Environment

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    Urbanization is a major feature in modern landscapes. As humans progressively develop land, a patchwork environment appears, with wide variation in the degree of modification. Different animal species can survive in each level of this urban gradient, with populations persisting in disjointed patches of suitable habitat. In this study, I evaluated how urbanization in the Philadelphia Metropolitan Area has affected the population genetics of four ant (Formicidae) species of varying urban aptitude. My focal taxa include Aphaenogaster rudis, a woodland ant which requires forest habitat, Camponotus pennsylvanicus and Crematogaster cerasi, two species which both can inhabit edge habitat and nest in rotting wood, and Nylanderia flavipes, an invasive species known for saturating urban areas. To investigate how each species was impacted, I used microsatellite genotyping with two analysis methodologies: Bayesian population assignment and landscape resistance modeling. Regarding the latter, I tested four hypotheses concerning the relationships between genetic differentiation and landscape characteristics: 1) isolation-by-distance, 2), major geographic barriers, 3) the urbanization gradient, and 4) a habitat suitability gradient. Overall, I found low genetic structure across the four species, but interspecific variation in how landscape characteristics influence genetic differentiation. My results show that genetic response to urbanization in ants varies greatly depending on species and context, with low predictability based on apparent aptitude for the urban environment

    Health Literacy among Rural Emerging Adults with Chronic Pain: Implications for Behavioral Health and Treatment

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    Emerging adulthood is a developmental period in the late teens and early twenties that is critical for addressing chronic pain and preventing pain-related morbidity and mortality, especially for emerging adults with rural residency. Emerging adults with chronic pain experience environmental and behavioral vulnerabilities, which disrupt typical developmental trajectories and increase long-term risk for poor chronic pain outcomes (Brown et al., 2021) at a time when they are becoming increasingly responsible for their own pain management and health decisions. In addition to the vulnerabilities associated with emerging adulthood and chronic pain, rural residency has also been linked with higher prevalence rates of chronic pain (Dahlhamer et al., 2018) and increased risk for worsened pain outcomes (Thorn et al., 2011). For rural emerging adults with chronic pain, health literacy may be a key driver of treatment engagement and behavioral health outcomes. By examining health literacy measurement, predictors and outcomes in this unique disease and developmental context, this research provides a framework for new avenues for interventions to mitigate risk factors associated with health literacy challenges in rural emerging adults experiencing chronic pain. Rural emerging adults with chronic pain (M = 23.7 years; SD = 2.1 years) completed an anonymous, online questionnaire. Participants reported on health literacy, chronic pain variables, healthcare access status, and behavioral health factors. First, we examined the psychometric properties of a health literacy scale to examine reliability and validity of its use among rural emerging adults with chronic pain, establishing a three-factor scale. Next, our findings showed significant associations between health literacy and healthcare access, wherein increased distance to various healthcare professionals was associated with decreased health literacy. Further, our results indicated that increased health literacy was associated with decreased behavioral health outcomes, such as decreased pain interference, pain intensity, and decreased sleep difficulties. These results highlight the need for further research into the importance of health literacy for rural populations, as well as increased public policy efforts to ameliorate structural urbanism in healthcare for persons with chronic pain and other illnesses

    The Impact of Representative Scale in Groundwater Modeling

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    Inherent in the continuum equations that describe flow and transport in porous media is a component of scale. This is an artifact of the underlying assumptions necessary for transforming the complex pore-scale characteristics of soil into manageable state variables and parameters that are readily measurable in the field (e.g., piezometric head and hydraulic conductivity). The mechanism used to formulate the upscaled porous medium equations involves Averaging Theory in which a representative elementary volume (REV) is used. This REV acts as an integration volume where pore-scale quantities are averaged over a macroscale volume. The REV defines all aspects of the modeling process—from the coefficients that describe the soil parameters, to the state variables that the models predict. Despite its ubiquity, knowledge of its actual size or its impact on numerical model outputs is unknown. The work presented here includes five experiments involving a highly instrumented physical bench-top sandbox model that provide insights into the impact scale plays on a physical groundwater system. State variable measurements including piezometric head and solute concentration are determined at different scales using an areal averaging technique. These measurements are used to calculate the relevant soil hydraulic and transport parameters at well-defined scales. The resulting parameters are then employed in an equivalent numerical simulation. Comparisons between the measured and simulated outputs at the same scale show that the REV averaging size plays an important role in model results. A convergence of simulated head and solute concentration data with consistently averaged measured values occurs at larger REV sizes, however at a loss of some macroscale heterogeneities. The results of this work suggest that the optimal REV for modeling flow and transport in porous media is dependent on the soil type as well as the characteristics of the entire system to be modeled. They also reveal the importance of interpreting numerical models in the context of the scale at which they are created

    Non-Market Food Practices Do Things Markets Cannot: Why Vermonters Produce and Distribute Food That\u27s Not For Sale

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    Researchers tend to portray food self-provisioning in high-income societies as a coping mechanism for the poor or a hobby for the well-off. They describe food charity as a regrettable band-aid. Vegetable gardens and neighborly sharing are considered remnants of precapitalist tradition. These are non-market food practices: producing food that is not for sale and distributing food in ways other than selling it. Recent scholarship challenges those standard understandings by showing (i) that non-market food practices remain prevalent in high-income countries, (ii) that people in diverse social groups engage in these practices, and (iii) that they articulate diverse reasons for doing so. In this dissertation, I investigate the persistent pervasiveness of non-market food practices in Vermont. To go beyond explanations that rely on individual motivation, I examine the roles these practices play in society. First, I investigate the prevalence of non-market food practices. Several surveys with large, representative samples reveal that more than half of Vermont households grow, hunt, fish, or gather some of their own food. Respondents estimate that they acquire 14% of the food they consume through non-market means, on average. For reference, commercial local food makes up about the same portion of total consumption. Then, drawing on the words of 94 non-market food practitioners I interviewed, I demonstrate that these practices serve functions that markets cannot. Interviewees attested that non-market distribution is special because it feeds the hungry, strengthens relationships, builds resilience, puts edible-but-unsellable food to use, and aligns with a desired future in which food is not for sale. Hunters, fishers, foragers, scavengers, and homesteaders said that these activities contribute to their long-run food security as a skills-based safety net. Self-provisioning allows them to eat from the landscape despite disruptions to their ability to access market food such as job loss, supply chain problems, or a global pandemic. Additional evidence from vegetable growers suggests that non-market settings liberate production from financial discipline, making space for work that is meaningful, playful, educational, and therapeutic. Non-market food practices mend holes in the social fabric torn by the commodification of everyday life. Finally, I synthesize scholarly critiques of markets as institutions for organizing the production and distribution of food. Markets send food toward money rather than hunger. Producing for market compels farmers to prioritize financial viability over other values such as stewardship. Historically, people rarely if ever sell each other food until external authorities coerce them to do so through taxation, indebtedness, cutting off access to the means of subsistence, or extinguishing non-market institutions. Today, more humans than ever suffer from chronic undernourishment even as the scale of commercial agriculture pushes environmental pressures past critical thresholds of planetary sustainability. This research substantiates that alternatives to markets exist and have the potential to address their shortcomings


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