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Effects Of Sediment Addition On Macroinvertebrate Communities In New England Salt Marshes, Chloe Brownlie

Master's Theses and Capstones

Salt marsh invertebrates play a vital role in salt marsh ecosystems by aerating the marsh, cycling nutrients, and forming connections between trophic levels, but the impacts of large-scale natural and anthropogenic sediment addition on their community structure and species composition is poorly understood. During winter storm Grayson in January of 2018, ice rafting caused large areas of sediment to deposit on significant areas of the Great Marsh in Massachusetts. I hypothesized that sediment addition would influence the abundance and richness of invertebrates in the marsh, because they tend to take years to recover after a disturbance. Sediment cores were taken …

Investigating The Role Of Palmitoyl Acyltransferase 14 In Preventing Early Death In Arabidopsis Thaliana, Robert Elliott

Master's Theses and Capstones

Palmitoylation is a reversible post-translational modification that affects the location, activity, and stability of proteins. Arabidopsis thaliana contains 23 genes for palmitoyl acyltransferases (PATs), the enzymes that catalyze palmitoylation. Loss of PAT14 activity results in early senescence and diminished plant size when plants are grown on standard peat/perlite mixtures in pots and watered with a commercial fertilizer, but this phenotype is not observed when plants grown on agar plates containing a different nutrient solution. Here we show that neither the peat/perlite growth medium nor the commensal microbes present in the growth are the causative agents for phenotype development. However, the …

Perceived Gender Discrimination In The United States Air Force, Linzi Gail Eppinger

Master's Theses and Capstones

While the existence of gender discrimination in the Air Force is well known, previous research had not examined how active-duty Air Force members define gender discrimination and how service members differentiate instances of gender discrimination from gender-based harassment. This study drew on qualitative interviews with 25 Air Force service members to provide a rich account of their perceptions of discrimination and harassment. From this research, several common attributes of gender discrimination became clear. Active-duty Air Force women were more aware of instances of gender discrimination than men, participants perceived being a gender minority in the workplace is a risk factor …

Determining The Role Of Environmental Variability On Marine Megafauna Abundance Trends: A Case Study Of Cocos Island, Costa Rica, Julia Saltzman

Master's Theses and Capstones

Despite being economically, ecologically, and culturally important many species of marine megafauna are threatened with extinction. The reasons for the imperiled state of many marine megafauna include overfishing, habitat loss, pollution, and climate change. Marine Protected Areas (MPAs) are often proposed as a management tool for marine megafauna. However, it is difficult to monitor the efficacy of marine protected areas when it is unclear if abundance trends are due to management or environmental variability. Indeed, many studies to date on the efficacy of MPAs fail to account for environmental variability, or account for limited covariates. In this thesis, I examine …

Reccurent Neural Network For The Detection Of Odontocetes, Christopher Michael Foster

Master's Theses and Capstones

This research project explores the ability of a Recurrent Neural Network to detect Odontocetecalls. With the current degree of climate change impacting the planet, being able to better track and locate highly mobile endangered species is imperative. An example of such a species is the Sperm Whale, which is listed as endangered under the United States Endangered Species Act, that migrate annually and have a range that extends through all the world’s oceans. Current methods of detection require a great deal of manual interaction and skill on behalf of the identifier. Automating this process would enable easier tracking and aid …

Characterizing The Traditional Fisheries Of Salary, Madagascar Within A Marine Protected Area, Caitlin R. Shanahan

Master's Theses and Capstones

Protected Areas are a tool used by the International Union Conservation of Nature (IUCN) to limit changes to and preserve important and fragile ecosystems, allowing varying permissible activities within their boundaries. Locally Managed Marine Areas (LMMAs) are a similar tool, but with a higher emphasis of community engagement in the planning process with community-based ownership and regulation. In Madagascar, there are both IUCN Marine Protected Areas (MPAs) and LMMAs established to help conserve their high marine biodiversity and healthy reef systems. While the LMMAs and some of the MPAs permit sustainable fishing, it is unknown if the traditional, small-scale fisheries …

Spatiotemporal Patterns Of Dissolved Organic Nutrient Lability Across The Subtropical North Pacific, Jessica Quinn Gray

Master's Theses and Capstones

Net biologically produced organic matter integrated over an annual cycle in the euphotic zone of the global ocean is equal to annual net community production (ANCP). ANCP is limited by the rate of delivery of essential nutrients (nitrogen (N), phosphorus (P), and iron (Fe)) to the sunlit surface ocean and the efficiency with which these nutrients are either metabolized or returned to the ocean’s interior. In subtropical oceans, which are regions of large-scale downwelling and consequently characteristic of nutrient-depleted surface waters, ANCP remains comparable to more nutrient replete ecosystems (~2 – 5 mol C m-2 yr-1). To understand what may …

Development Of A Continuous-Tension-Compression Machine For Testing Thin Sheet Metal, Jacqueline Mcnally

Master's Theses and Capstones

This thesis details the design and manufacturing of a custom testing machine for thin sheet metal undergoing continuous tension-compression (CTC) loading. The CTC machine concept is based on using a set of intermeshing dies to continuously support the thin sheet specimen against buckling during the test. The upper set of dies are held in place by a pneumatic actuator of 25 kN capacity. The dies can move freely relative to one another, so that both tension and compression can be performed in the same setup. A hydraulic actuator of 50 kN capacity displaces one side of the intermeshed dies. The …

Automated License Plate Recognition Systems, Nicholas Noboa

Master's Theses and Capstones

Automated license plate recognition systems make use of machines learning coupled with traditional algorithmic programming to create software capable of identifying and transcribing vehicles’ license plates. From this point, automated license plate recognition systems can be capable of performing a variety of functions, including billing an account or querying the plate number against a database to identify vehicles of concern. These capabilities allow for an efficient method of autonomous vehicle identification, although the unmanned nature of these systems raises concerns over the possibility of their use for surveillance, be it against an individual or group. This thesis will explore the …

A Geographic Segmentation Approach For Satellite-Derived Bathymetry, Juliane Jussara Affonso

Master's Theses and Capstones

Safety of navigation depends on our knowledge of seabed and its features, and, as such, any improvements in deriving bathymetry for nautical chart updating are of major importance. Satellite-Derived Bathymetry (SDB) is an alternative to traditional surveys using ship and airborne sensors, particularly for mapping remote and shallow areas, due to its reduced cost and the absence of navigational risks in very shallow and unsurveyed areas. However, the accuracy of SDB can be judged as relatively low for nautical charting purposes and, therefore, is mostly used for reconnaissance or/and for filling gaps in remote or very shallow areas. One of …

The Influence Of Permafrost Soil Structure On Microbial Community Diversity And Abundance, Nathan D. Blais

Master's Theses and Capstones

Soil structure plays a critical role in shaping soil microbial communities, who directly influence biogeochemical cycling1–4. Although well-studied in temperate systems, the importance of physical structure on soil microbial community diversity, function, and overall activity in permafrost soils is largely unknown. I hypothesized that (1) decreases in pore connectivity would increase microbial diversity based on an expected inverse relationship between diversity and connectivity; (2) soil with an increased abundance of larger pores (> 75 µm), which are uninhabitable because they are too large to sustain liquid water, will exhibit lower bacterial and archaeal abundance and (3) the surface area of …

Implementing A Reference Backscatter Calibration Technique On A Multi-Sector Multibeam Echosounder, Rui Miguel Aleixo Miguel Cândido

Master's Theses and Capstones

Increasingly, national hydrographic agencies are committing to routine acquisition of seabed backscatter strength estimates from multibeam echosounders (MBES) as part of national programs for seabed characterization. As part of their bathymetric survey mandate, these agencies have a long history of sounding quality control utilizing absolute and relative calibration (reference surfaces and crossover comparisons). Equivalent quality control is, however, not yet in place for managing seabed backscatter strength measurements, as the majority of the collected data is not absolutely referenced.Herein, a new technique for cross-calibrating a MBES with a reference calibrated split beam echosounder (SBES) was implemented. Broadband reference bottom backscatter …

Design And Synthesis Towards Bifunctional 89zr And 44sc Chelators For Immuno-Positron Emission Tomography, Noah Cote

Master's Theses and Capstones

The design and synthesis of novel zirconium and scandium complexes, ZrIV(p-NO2-sal-DFO) and ScIII(p-NO2-Bn-NOTPi) respectively, and their potential for use in immuno-positron emission tomography (immuno-PET) are discussed. The design for a linear octadentate ligand for Zr was hypothesized and derived from deferoxamine B (DFO), a well-known hexadentate siderophore for Fe complexation. A p-NO2-salicyclic acid derivative was prepared to provide a bifunctional handle for antibody conjugation. Deferoxamine B chelates with hydroxamate moieties, which have proven useful for chelation of hard acids. While difficulties in purification led to no complexation studies being performed, this chelator was confirmed via 1H NMR , 13C NMR, …

Transgender Health: Exploring Medicalization And The Interactions Of Race/Ethnicity, Disability, And Education, Evan Thomas England

Master's Theses and Capstones

There is a wide range of experiences among and between transgender, BIPOC (Black, Indigenous, people of color) and disabled groups, but they all share histories of medicalization that result in marginalized health experiences and access to health care. To what extent do these health experiences and outcomes vary for U.S. adults with multiply marginalized intersectional identities? How, if at all, does the established moderating capability of education impact health outcomes for people who are transgender? Using data from the 2020 Behavioral Risk Factor Surveillance System, this study utilizes regression modelling to explore the interactions of race/ethnicity, disability, and education with …

Physiology And Biochemistry Of Cold-Hardy Table Grapevines, Annasamy S. Chandrakala

Master's Theses and Capstones

Grapes are grown worldwide to produce wine, grape juice and are also popular as fresh table grapes or dried raisins. Due to their nutritional value and importance in the multibillion-dollar wine industry, grapes are considered the most commercially important berry crop. Grape production has primarily concentrated on European wine grapes, Vitis vinifera, in the dry, hot Mediterranean and Central Asian climates. V. vinifera is not cold tolerant enough to endure winter temperatures below -15°C. The introduction of several interspecific hybrids (of both wine and table grape) cultivars in the 20th century and selection of a training system has helped propel …

Cosmogenic 36cl Dating Of The Granite Canyon Moraine Complex In The Teton Range To Determine Fault Offset Rates And The Influence Of Valley Hypsometry On Glacier Behavior, Calen M. Rubin

Master's Theses and Capstones

During the Last Glacial Maximum, major drainages along the east side of the Teton Range were occupied by alpine glaciers that extended to the floor of Jackson Hole. Chronologies of glaciation in the central and northern parts of the range have been developed via 10Be exposure dating of well-preserved terminal and lateral moraine complexes. However, few glacial records have been developed in the southern portion of the range. The metamorphic and sedimentary bedrock and shallow hypsometry of Granite Canyon stand in contrast to the crystalline lithology and steeper hypsometry of glaciated valleys further north along the eastern range front. Granite …

Do We Really Know What Is In Our Food? The Connection Between Dietary Mycotoxin Exposure And Pediatric Crohn’S Disease, Susan L. Gonya

Master's Theses and Capstones

AbstractBACKGROUND: The incidence of pediatric Crohn’s disease (CD) has increased over the past few decades. The etiology of CD has not yet been elucidated. Still, researchers have identified variables associated with the disease process, including genetic predisposition, environmental triggers like a poor-quality diet, air pollution, water pollution, and a dysbiotic microbiome with increased fungal diversity as predisposing factors. Fungal mycotoxin contamination in the food supply from toxicants like Deoxynivalenol (DON), a highly prevalent gastrointestinal irritant, has largely been ignored as a potential factor influencing the fungal dysbiosis and symptoms associated with the disease process. It is hypothesized that global and …

I. Incorporation Of Functionality At The Β-Position For The Zinc-Mediated Chain Extension Reaction Ii. Formal Synthesis Of Heliotridane And Pseudoheliotridane Through A Zinc-Mediated Chain Extension Approach, Nicholas Alexander Arnista

Doctoral Dissertations

The zinc-mediated chain extension reaction has been previously developed to incorporate alkyl or aryl substituents at the β position of the chain-extended product. The incorporation of heteroatom functionality at the β position of the chain-extended product was demonstrated through the use of a functionalized zinc carbenoid species. Silyl ether-functionalized geminal diiodides were used in the chain extension reaction with low to modest yields. Optimization of the chain extension reaction was performed by modification of solvent, reaction temperature, reaction time, and addition of diiodide. The chain extension reaction was performed on several different substrates, such as β-keto esters, β-keto amides, and …

Structural And Biochemical Characterization Of The Allosteric Regulation Of Photoreceptor Phosphodiesterase, Richa Garg

Doctoral Dissertations

ABSTRACT

Structural and Biochemical Characterization of the Allosteric Regulation of Photoreceptor Phosphodiesteraseby Richa Garg

The photoreceptor phosphodiesterase (PDE6) is the central enzyme in the visual signaling pathway. Cone PDE6 is a homodimer consisting of a catalytic dimer (Pα’α’) and two cone-specific inhibitory γ-subunits (Pγ’). Rod PDE6 is a heterotetramer which consists of a catalytic dimer (Pαβ) with two rod-specific Pγ subunits. The PDE6 differs from other phosphodiesterases (PDEs), in its unique inhibitory Pγ subunit and its activation by α-subunit of the G-protein (Gα). Regulation of PDE6 activity is a key factor in determining the electric response upon light stimulations. PDE6 …

Primary Cilia In The Pathogenic Mouse Brain & Eeg Waveform Analysis Of A Mouse Model Of Alzheimer's Disease, Ashley Diemand Sterpka

Doctoral Dissertations

In the last two decades, primary cilia have become recognized as tiny sensory organelles with considerable physiological function including regulation of cell division and modulation of transduction pathways. Scientists build on former discoveries, identifying new connections and accentuating the value of primary cilia in disease and intercellular signaling. Astrocytes, the most numerous cell type within the brain, act in support of neurons and maintain neurological health by providing neurotrophic factors and removing synaptic debris. These cells are particularly significant in reparations following neural injury and diseases, altering shape and function to protect healthy tissue. Astrocytes display primary cilia, yet little …

Modeling And Assessing The Sustainability Of Distributed Solar Photovoltaics Adoption, Mingcheng Ren

Doctoral Dissertations

Participation of distributed solar photovoltaic (PV) generation in the organized electricity wholesale market is expected to increase under the Federal Energy Regulatory Commission Order 2222 announced in 2020. Our understanding about the technical, economic, and environmental tradeoffs and co-benefits of solar PV adoption on both building and regional scales remains limited, especially considering the complexity of varied distributed solar PV-battery system designs and operation strategies as well as the dynamic interactions of these distributed generations with the centralized grid. This dissertation therefore aims to investigate the grid load reduction, life cycle cost, and life cycle environmental (e.g., carbon, water, and …

Essays On The Effects Of Air Quality And Intra-Industry Trade On Labor Market Outcomes, Protika Bhattacharjee

Doctoral Dissertations

This dissertation examines the impacts of poor air quality and the rise of intra-industry trade on different labor market outcomes like migration, workings hours, and wages. This thesis contributes two distinct strands of literature, literature on air pollution focusing on the economic consequences of poor air quality, and international trade literature. The first two essays examine how a moderate level of air pollution can drive migration decisions and impact working hours in the United States. The third essay investigates the role of the rise in within industry trade on occupational wages in the United States. This dissertation aims to contribute …

Socioscientific Decision-Making In Undergraduate Students: The Role Of Personal Epistemology, Jordan Dana Bader

Doctoral Dissertations

Socioscientific issues (SSIs), or controversial scientific issues with social implications, influence members of society regardless of demographic. SSIs are contentious and ill-structured, meaning they do not have a definitive answer. To properly equip students with the tools needed to handle SSIs, undergraduate science curricula emphasize scientific literacy skills, such as the ability to search, recognize, and utilize accurate scientific information when handling science driven issues outside of the classroom. However, SSIs are influenced by political, social, economic, and cultural stakeholders. Therefore, students may not be basing their SSI decisions off of accurate information. An individual’s personal epistemology is known to …

Synthesis Of Thioacids And Dicarboxylic Acids Derived From Open Β-Lactams For Inhibition Of Metallo-Β-Lactamases, Junfu Chen

Doctoral Dissertations

Antibiotics are important substances that have been used in clinical treatment for over 70 years. Because of overuse and misuse of antibiotics, bacteria developed resistance. However, bacterial resistance towards antibiotics, especially the β-lactam antibiotics, is becoming increasingly threat. Currently, the β-lactam antibiotics are seriously threatened by β-lactamases. Metallo-β-lactamases (MBLs), a sub-class of β-lactamases, have been found in several bacteria since they confer resistance to many different β-lactams, and as a result, the bacteria survive in their presence. A potential treatment is to synthesize inhibitors of MBLs, however, there are no inhibitors synthesized in clinical use. The goal of this project …

Heat Transport By Baroclinic Acoustic Streaming, Jacques Abdul Massih

Doctoral Dissertations

Acoustic streaming refers to time-averaged flows generated by time-periodic sound waves. In classic“Rayleigh streaming”, the mean flow is generated by the interaction of a standing acoustic wave with a solid boundary (e.g., a channel wall). Applications of acoustic streaming include inducing fluid mixing in microfluidic medical devices, improving the efficiency of chemical reactions, and enhancing heat transfer. Recently, Chini et al. [J. Fluid Mech., Vol. 744 (2014)] and Michel & Chini [J. Fluid Mech., Vol. 858 (2019)] demonstrated that strong acoustic streaming flows can be generated in gases subjected to an imposed cross-channel temperature gradient. In contrast with Rayleigh streaming, …

Sociocultural Dimensions Of Environmental Stewardship In New Hampshire: Implications For Adult Environmental Education, Ian Patrick Hanley

Doctoral Dissertations

The overarching aim of this dissertation is to expand evidence and theory of adult identity processes in the context of environmental stewardship, as well as to provide knowledge and recommendations to environmental stewardship and environmental education professionals. The intent is to better understand variation in how adult environmental stewards report on and value their own engagement with both sociocultural and natural systems. This line of inquiry stems from the fundamental claim that environmental stewardship activity is not singularly based on environmental content knowledge but is also related to forms of cultural and social engagement. By recognizing these dual aspects of …

Efficient Data-Driven Robust Policies For Reinforcement Learning, Bahram Behzadian

Doctoral Dissertations

Applying the reinforcement learning methodology to domains that involve risky decisions like medicine or robotics requires high confidence in the performance of a policy before its deployment. Markov Decision Processes (MDPs) have served as a well-established model in reinforcement learning (RL). An MDP model assumes that the exact transitional probabilities and rewards are available. However, in most cases, these parameters are unknown and are typically estimated from data, which are inherently prone to errors. Consequently, due to such statistical errors, the resulting computed policy's actual performance is often different from the designer's expectation. In this context, practitioners can either be …

Compound, Elemental, And Isotopic Perspectives On Mercury Mobilization During Thaw In A Discontinuous Permafrost Zone, Maria F. Fahnestock

Doctoral Dissertations

Arctic ecosystems are a major global sink for both carbon (C) and mercury (Hg), both of which are influenced by anthropogenic activities. The accelerated climate-change-induced warming documented in the Arctic has led to permafrost thaw resulting in landscape evolution from hydrological, vegetation and microbial shifts. All of these resulting changes have the potential to influence how Hg, a toxic contaminant, is mobilized and re-cycled in this ecosystem. In this body of work, I investigate patterns of Hg speciation, elemental abundances, and stable isotopes across the thaw gradient in a permafrost peatland and interconnected freshwater lakes in Abisko, Sweden to assess …

Metareasoning For Heuristic Search Using Uncertainty, Tianyi Gu

Doctoral Dissertations

Heuristic search methods are widely used in many real-world autonomous systems. Yet, people always want to solve search problems that are larger than time allows. To address these challenging problems, even suboptimally, a planning agent should be smart enough to intelligently allocate its computational resources, to think carefully about where in the state space it should spend time searching. For finding optimal solutions, we must examine every node that is not provably too expensive. In contrast, to find suboptimal solutions when under time pressure, we need to be very selective about which nodes to examine. In this dissertation, we will …

Biologically Inspired Computer Vision/ Applications Of Computational Models Of Primate Visual Systems In Computer Vision And Image Processing, Reza Hojjaty Saeedy

Doctoral Dissertations

Biologically Inspired Computer VisionApplications of Computational Models of Primate Visual Systems in Computer Vision and Image Processing Reza Hojjaty Saeedy Abstract Biological vision systems are remarkable at extracting and analyzing the information that is essential for vital functional needs. They perform all these tasks with both high sensitivity and strong reliability. They can efficiently and quickly solve most of the difficult computa- tional problems that are still challenging for artificial systems, such as scene segmentation, 3D/depth perception, motion recognition, etc. So it is no surprise that biological vision systems have been a source of inspiration for computer vision problems. In …