Digital Commons Network^™

Coarse-Grained Models For Microbial Metabolisms And Biological Interactions, Meng Gao

Open Access Dissertations

Microorganisms are microscopic, typically unicellular organisms widely distributed across the world’s environments.  In the global ocean, they account for the majority of primary production and decompose organic matter to drive nutrient cycles. Through their metabolic processes, including photosynthesis, dinitrogen (N₂) fixation, sulfur oxidation, and methanogenesis, microbes contribute to global biogeochemical processes, and establish their ecological niches in suitable habitats. Their biological interactions, including competition, symbiosis, and grazing, are important links among different functional groups in marine communities. Consequently, quantifying microbial metabolisms and their biological interactions is important to investigate their ecological functions in marine ecosystems and the global …

Ecce Leadership Development: Supports, Barriers, And Identity Formation, Andrea Weidele

Open Access Dissertations

Early childhood care and education (ECCE) leadership development is not given the attention it deserves. Despite the proven link between high-quality ECCE programs and positive societal outcomes, leadership development within the sector is significantly under-resourced. Because program quality is inherently tied to leadership efficacy, there is an urgent need to investigate the supports and structures that foster effective ECCE leadership. This study addressed that gap by using a qualitative multiple case study to explore how six ECCE program leaders of licensed ECCE programs from a New England state describe their leadership development, including supports and barriers they encountered and how …

Linking Phytoplankton Physiology And Ecology To Global Biogeochemical Cycles: A Modeling Approach, Margaret Bernish

Open Access Dissertations

Phytoplankton, or microscopic primary producers, contribute to carbon export through the biological transformation of carbon dioxide into organic molecules. Phytoplankton are responsible for approximately half of global net primary production, while only contributing minimally to total photosynthetic biomass. Despite their important role in the global cycling of nutrients, phytoplankton physiology and ecology are often highly simplified in global biogeochemical models. This dissertation elucidates the role of phytoplankton physiology and ecology within biogeochemical cycles, allowing for better characterization of marine microbial distribution and better representation of nutrient cycling for interpretive and predictive models. The development of formulations that link physiological responses …

Investigating The Effects Of Nucleopore Defects On The Cellular Response To Stress In Als/Ftd Ipsc-Derived Neurons, Alicia Christine Collins

Open Access Dissertations

Amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) is a progressive neurodegenerative disease spectrum characterized by motor dysfunction, cognitive decline, and death within a few years of clinical onset. Hallmark features of ALS/FTD include defects in nucleocytoplasmic transport (NCT) and abnormal cytoplasmic mislocalization and aggregation of the RNA-binding protein TDP-43, both of which have been shown to be exasperated by oxidative stress (OS). It remains unclear how these processes are connected and how they collectively contribute to neurodegeneration. To fill this gap of knowledge, we used human embryonic kidney cells, neuroblastoma cells, and induced pluripotent stem cell-derived cortical neurons harboring the ALS/FTD C9ORF72 …

Submesoscale Dynamics Of Phytoplankton And Carbon Export Revealed By High-Resolution Airborne And Satellite Remote Sensing Of Currents And Ocean Color, Sarah E. Lang

Open Access Dissertations

Satellites and airborne sensors reveal submesoscale (1 - 10 km) variability in ocean color in the form of filaments, eddies, and patches. The variability in ocean color is closely tied to the physical dynamics that restructure phytoplankton distributions and drive active biological responses like changes in primary productivity and community structure. As the base of the marine food web and a key component of the biological carbon pump, phytoplankton are crucial to the overall health of marine ecosystems and to the ocean's role in climate. This dissertation focuses on the use of airborne and satellite remote sensing to study the …

Optimizing Poultry Production And Enhancing Egg Nutrient Composition Through Kelp Supplementation In Laying Hens, Meghan Clifford

Open Access Dissertations

The development of sustainable feed supplements is a crucial component in addressing the current global need for resilient and environmentally responsible food systems. This dissertation has explored the potential of brown algae (Saccharina latissima) as a sustainable feed supplement for poultry with the potential to benefit production efficiency, product quality, and the global food supply. With both controlled feeding trials and a producer-based survey, the work in this dissertation investigates the nutritional, biological and practical implications of adopting kelp into poultry diets.

Chapter one provides a comprehensive overview of the current literature surrounding the use of marine sources …

Coral Holobiont Lipidome Response To Global Change, Lauren Zane

Open Access Dissertations

Climate change is fundamentally restructuring macro-scale marine ecosystem structure and function by altering microscale metabolic processes and patterns of energy allocation. Scleractinian corals, as major ecosystem engineers, play outsized roles in ecosystem structure and function. They also occupy diverse habitats that differ in temperature regimes, light environments, hydrodynamics, and other environmental conditions, exposing corals to substantial spatial variation in stress and resource availability. Their fragile nutritional symbiosis with algal endosymbionts helps them navigate these environmental variations, but are also highly sensitive to environmental stress, particularly the timing and magnitude of water temperature changes. As pressure from environmental changes increases, the …

Ultra-Rapid Electrophilic Cysteine Arylation Using Pyridinium Salts, Bradley M. Lipka

Open Access Dissertations

Small molecule-based bioconjugation enables in vitro and in vivo functionalization of proteins and peptides, significantly expanding the chemical space of biomacromolecules. Among these transformations, nucleophilic aromatic substitution (S_NAr) of cysteine residues is a widely employed strategy for protein bioconjugation.

Although many reagents facilitate cysteine arylation, they are disadvantageous in two crucial aspects - limited synthetic modularity and undesired hydrophobicity. First, conventional cysteine arylating reagents are frequently activated by multiple electron-withdrawing groups (EWGs) on a single aromatic ring, leaving few synthetic handles to derivatize the reagents for advanced applications. Second, these labeling reagents are generally hydrophobic in nature and …

The Relationship Between Pillar[5]Arene And Pillar[6]Arene In The Synthetic Route To A Water-Soluble Pillar[6]Arene: A Case Of Kinetic And Thermodynamic Products Or Two Distinct, Competing Reactions, Helice A. Gillis

Open Access Dissertations

Pillar[n]arenes, discovered in 2008, have already made their mark as a formidable addition to the field of supramolecular chemistry, largely due to their host-guest chemistry. While the synthesis of pillar[5]arene is well established, the synthesis of pillar[6]arene, with its larger core, has not been so straightforward and mainly accomplished through the use of bulky solvents. Here we present an optimized method for a reproducible, acid-catalyzed synthesis for a brominated pillar[6]arene, starting with a brominated monomer and using chloroform as the templating solvent. Our studies have demonstrated the ratio of brominated pillar[6]arene to brominated pillar[5]arene increases with both decreasing concentration of …

The Relationship Between Mental Health Disclosures, Employee Sentiments And Turnover Intention In The Workplace, Steve G. Winkel

Open Access Dissertations

Purpose. The purpose of this study is to examine the relationship between employees’ disclosure of mental health conditions in the workplace and these employees’ sentiments, feelings, and associated outcomes. Utilizing constructs of job satisfaction, affective commitment, normative commitment, motivation, and turnover intentions, the research aims to understand quantifiable differences in the employment experience between employees who disclose and do not disclose (non-disclosure) mental health conditions, as well as the mediating roles of human resources management (HRM), supervisors support, and employee authenticity. Through self-reported data detailing employees’ disclosure experiences, the research also aims to understand the disclosure conversation's specific impact …

Quantifying Links Between Phytoplankton Physiology And The Environment, Gabrielle M. Armin

Open Access Dissertations

Phytoplankton are microscopic, primary producers in aquatic ecosystems worldwide. They are key links in global biogeochemical cycles, converting inorganic compounds into bioavailable nutrients which fuel fisheries. Through photosynthesis, phytoplankton play an essential role in the carbon cycle and marine biological pump, drawing carbon from the atmosphere, which is eventually sequestered in the oceans, regulating our Earth’s climate. Due to their influential role in large scale processes, there have been many efforts to characterize and quantify phytoplankton impacts to ecosystem health and global nutrient cycles. Often, phytoplankton physiology has been highly simplified in global or ecosystem models, limiting their representation to …

Machine Learning For Optimized Ocean Exploration Data Analysis, Puja Banerjee

Open Access Dissertations

The deep sea remains one of the most crucial frontiers in Earth sciences, with vast unknowns regarding its biodiversity, ecosystem dynamics, and geological features and processes, and impact and interaction with humans. Ocean exploration seeks to address this gap by focusing data collection in some of the least known places on the planet in order to significantly expand our knowledge of marine ecosystems, geological formations, and oceanographic processes. Ocean exploration datasets provide crucial insights into a wide range of scientific domains including: deep sea biodiversity, seafloor morphology, and deep-sea soundscapes. The advent of autonomous and remotely operated underwater vehicles (AUVs …

Molecular Interactions Between The Shellfish Pathogen Vibrio Coralliilyticus Re22 And The Probiont Phaeobacter Inhibens S4sm, Jessica Coppersmith

Open Access Dissertations

Oyster larvae aquaculture is an important industry, both economically and environmentally, helping to create sustainable food systems by supplying seed oysters to farms, and also to restoration projects aimed at building coastal resilience and improving water quality by rejuvenating wild populations. However, oyster larvae are highly susceptible to rapid mortality events, crashes, which can seriously impact the industry. One source of these crashes in hatchery systems is vibriosis, caused by pathogenic species of Vibrio bacteria that are ubiquitous in temperate coastal waters, and with rising surface water temperatures their prevalence and virulence are increasing. To prevent these larval crashes from …

The Effect Of Maternal Diet On Developmental Programming: A Cross Species Analysis, Lindsey Eileen Eaton

Open Access Dissertations

Maternal nutrition plays an important role in shaping offspring health through developmental programming, with lasting implications on metabolic function and disease susceptibility. This dissertation explores the molecular and physical consequences of maternal nutrition, particularly its effects on pancreatic development and function in offspring. Chapter one provides a comprehensive review of the literature, detailing the mechanisms of fetal development, epigenetic regulation, and metabolic programming. It highlights the thrifty phenotype hypothesis, the role of DNA methylation and histone modifications, and the impact of maternal nutrition, emphasizing how nutrient availability during pregnancy influences fetal organogenesis and long term metabolic health.

Chapter two examines …

Development And Characterization Of Polysaccharide-Based Controlled Drug Delivery Platforms, Amanda Pepler

Open Access Dissertations

Drug delivery research focuses on overcoming challenges in patient treatment. Most therapeutics are delivered systemically through oral or intravenous routes. However, these administration methods are often inefficient due to therapeutic hydrophobicity, poor bioavailability, and liver metabolic clearance, necessitating frequent dosing. When treatment plans require frequent dosing, patients experience significant fluctuations in therapeutic concentration in the bloodstream, which can increase adverse side effects. These factors contribute to low patient compliance. Therefore, the core focus of drug delivery research is to develop new administration routes for therapeutics. Drug delivery systems (DDS) that can target therapeutics to a localized region offer advantages over …

Probing Biomolecular Structure And Dynamics Via Infrared Action Spectroscopy, Madeline Schultz

Open Access Dissertations

Biomolecular structure is supported by a network of inter- and intramolecular interactions, which can be inherently complex in the condensed phase. Isolating biomolecules from the condensed phase to vacuum, via electrospray ionization (ESI), can afford precise control over experimental conditions, yielding additional structural insight. However, the loss of solvation inherent to the ESI process can drive structural rearrangement, particularly at charge sites.

Microsolvation reagents can be used to partially mimic the solvation of charged moieties in solution as they are brought into the gas phase through complexation. This serves two primary functions: 1) reducing propensity for structural rearrangement of systems …

Novel Methodology And Proof-Of-Concept For Proton Ct Using Spot Profile Rather Than Bragg Peak Location, Brett Albert Ruben

Open Access Dissertations

Proton radiation therapy offers a highly precise method for cancer treatment, theoretically providing superior dose deposition characteristics compared to conventional X-ray radiation therapy. Its steep and finite dose fall-off region allows for superior tumor coverage while reducing, though not eliminating, dose to surrounding healthy tissue. However, its full potential is limited by range uncertainties, particularly those arising from the reliance on X-ray-based imaging methods called computed tomography (CT) for proton-based treatment. CT image Hounsfield Units (HU) must be converted to stopping power ratios (SPR) as these ratios are the clinically relevant value for accurately planning particle interactions during proton therapy. …

Substance Use In Justice-Involved Youth: The Roles Of Adhd And Cd, Avery Beatty

Open Access Dissertations

The present study aimed to investigate the relationships between ADHD, CD, and comorbid ADHD and CD on cigarette, cannabis, and alcohol use among justice-involved youth (JIY). Data for the present study were derived from a randomized controlled trial (RCT) that compared the effectiveness of various interventions in reducing cigarette use among youth at a state juvenile correctional facility in the Northeastern United States. The total sample (N = 302) comprised incarcerated and detained youth (n = 243) who ranged in age from 13 to 19 years (M = 16.01, SD = 1.01). Additionally, the present finding revealed that the total …

Characterization Of Methodological Variability In Compound Specific Isotope Analysis Of Amino Acids (Csia-Aa), Audreyana Brown-Nash

Open Access Dissertations

The use of isotopes in the natural sciences stems from the principle that chemical reactions predictably alter the isotopic composition of a given sample. Recent advances in compound specific isotope analysis of amino acids (CSIA-AA) have paved the way for studies of increasingly complex ecological relationships, including the identification and characterization of organismal physiology, consumer-resource linkages, biogeochemical cycling, and movement ecology. The analytical power of CSIA-AA has caused an exponential increase in the number of application-based studies since its inception in the 1990s. With the technique constantly evolving to accommodate new research goals, it is important to understand how variation …

Quantifying Mixotrophy Potential As A Function Of Environmental And Biological Drivers In Coastal And Estuarine Plankton Communities, Erica Ewton

Open Access Dissertations

The discovery of mixotrophic plankton has bridged gaps in nutrient cycling budgets and altered the understanding of food webs and energy transfer. Mixotrophic plankton are capable of simultaneous or sequential photosynthesis and heterotrophy, providing multiple avenues of nutrition and thus reducing limitations that affect specialists. These energy dense cells provide increased biomass for higher trophic levels, which may increase organism sizes throughout the food web. Additionally, they may be physically denser, which alters biogeochemical cycling including carbon sequestration. The work presented here uses LysoTracker Green, an acidotropic stain that attaches to phagocytic vacuoles within potentially phagotrophic small (< 20 µm diameter) phytoplankton communities (‘mixoplankton’), to better understand their abundance, relative abundance, and growth rates in relation to the matrix of natural conditions they inhabit. Understanding the prevalence and drivers of mixoplankton is vital to better parameterize biogeochemical cycling and energy transfer in the ocean and for models that predict the fate of future oceans.In the first study, I compared the abundance of mixoplankton in the Northeast U.S. Shelf (NES) and Coastal California Current System (CCS) during two cruises in the NES in summer 2021 and one cruise in the CCS in summer 2022. These two contrasting coastal systems span the breadth of environmental conditions observed in temperate marine ecosystems and thus provided an opportunity to examine indicators of mixoplankton across temperate coastal regions. I discovered higher mixoplankton abundance in the NES than CCS yet similar population sizes of nanoeukaryotic photosynthesizers, resulting in higher relative abundance of mixoplankton in the NES than CCS. Across both systems, I found increased mixoplankton abundance associated with decreasing temperature and combined nitrate + nitrite concentrations (N+N), and increasing light intensity and Synechococcus abundance …

Investigating The Photophysical Dynamics Of Anthracene And Acridine Derivatives Using Time-Resolved Spectroscopy, Sophia Tiano

Open Access Dissertations

Anthracenes and acridines are among the simplest visible light absorbing heterocyclic and polycyclic aromatic hydrocarbons and as such are extensively used in a variety of applications including photosensitizers and fluorescent sensors. Although the photophysics of some derivatives have been studied in the past, there is still a lot of unknown fundamental information that is vital in order to optimize these molecules for particular applications. Transient absorption spectroscopy was used to study the photophysics of the 9-substituted methyl, hydroxymethyl and formyl derivatives of acridine and anthracene. The growth and decay of the triplet-triplet absorption peak were quantified for each dye in …

Real-World Clinical And Cost Effectiveness Of Osteoporotic Treatments In Men, Yu Ren

Open Access Dissertations

Osteoporosis is a condition characterized by the loss of bone mass, which increases the risk of fractures. In 2017-2018, the age-adjusted prevalence of osteoporosis among adults aged 50 and over was 12.6%, with 19.6% in women and 4.4% in men. Untreated osteoporosis can lead to a cycle of recurrent fractures that severely impact quality of life and place significant emotional, physical, and financial strain on patients, families, and healthcare resources. Approximately 50% of women and 20% of men will experience at least one fracture in their lifetime. In the United States, an estimated 1.5 million osteoporotic fractures occur each year, …

Consumer And Environmental Preferences: Discrete Choice Experiments And Machine Learning Applications In Ev Battery Adoption And Aquatic Invasive Species Management, Lufan Helen Liu

Open Access Dissertations

As climate change and resource scarcity drive a global shift toward cleaner energy systems and environmental conservation, understanding how individuals value sustainability-related interventions has become increasingly important. This dissertation contributes to this growing body of knowledge by applying and advancing discrete choice experiment (DCE) methodology to assess consumer and public preferences for two key environmental policy domains: (1) repurposed electric vehicle (EV) batteries for residential energy storage and (2) aquatic invasive species (AIS) management in New York State. Across all three chapters, the study examines how traditional econometric models and emerging machine learning (ML) methods can complement each other in …

A Socio-Ecological Investigation Of Ulithian Spearfishing, Joshua Pi

Open Access Dissertations

Coral reef socio-ecological systems (SESs) characterize the interconnected relationships between coral reef ecosystems and reef-dependent communities. One such SES exists in Ulithi Atoll, Federated States of Micronesia, where Ulithians fish, steward, and govern their reefs through customary marine tenure, traditional ecological knowledge, and cultural taboos. In recent decades, rapid modernization in Ulithi has introduced new fishing technologies, transformed fishing practices, and ultimately reshaped the functioning of Ulithi’s traditional SES. One significant change was the introduction of spearfishing during the mid-20^th century, which is more selective and individualistic compared to other community-centric fishing methods that have existed for generations. This …

Incorporating Time-Varying Parameters And Climate Drivers Into Fisheries Models, Rachel Catherine Marshall

Open Access Dissertations

Commercial fishing is a highly valuable industry in the United States and globally, and as such, managing based on the best available science is necessary to maintain important fish stocks. Some parameters in stock assessment models that are assumed to be constant over age and time may actually vary to an extent that stock assessment modeling results could be improved by allowing the parameters to vary in the models. In the present dissertation, two stock assessment parameters that are typically held constant are explored for potential time or age variance. Potential environmental drivers of nonstationary parameters are also explored. Productivity, …

Ischemia-Induced Cytoskeletal And Nuclear Disruptions Drive Neuronal Death And Dysfunction: Insights Into The Connection Between Stroke And Dementia From In Vitro And In Vivo Models Of Stroke, Emily Potts

Open Access Dissertations

Stroke and Alzheimer’s disease and related dementias (ADRD) represent two of the leading causes of neurological disability worldwide, and their prevalence is expected to rise as the global population ages. Although stroke is traditionally viewed as an acute vascular event, a growing body of evidence suggests that transient ischemic injury can trigger lasting cellular disturbances that increase neuronal vulnerability to later neurodegeneration. Understanding how ischemic stress alters neuronal structure and function, and how these changes may overlap with pathways implicated in ADRD, is an emerging focus for stroke and neurodegenerative researchers. This dissertation addresses these questions through an integrated combination …

Development Of A Scituate Reservoir Mitigation Model For Assessing Flood Control During Extreme Scenarios, Supria Paul

Open Access Dissertations

Effective reservoir management is essential for mitigating downstream flooding, especially with the increasing frequency and intensity of extreme weather events impacting major drinking water reservoirs such as the Scituate Reservoir in Rhode Island. These reservoirs provide water for large populations but can be overwhelmed by intense precipitation, flooding and land cover changes. Climate change is expected to increase precipitation in the study area located in New England, highlighting the need for improved reservoir systems, especially given the aging dams and higher risk of failures. Additionally, land cover changes, like the widespread defoliation caused by the Gypsy Moth infestations, affect water …

Light, Symbiosis, And The Biology Of Corals, Taylor R. Lindsay

Open Access Dissertations

Light is critical for the survival of most shallow water scleractinian corals. Corals are mixotrophs, acquiring energy via both feeding on water column plankton and photosynthesis via a symbiotic relationship with dinoflagellates living within their tissues. Corals rely heavily on photosynthetically derived metabolites through this symbiotic relationship, intrinsically linking their biology to light availability. Corals are known to modulate their biology to maximize light capture. However, there is a limited understanding of the interaction between morphology, physiology, and energetic strategy, as well as how light may affect these relationships. In Chapter 1, we quantified the morphology, physiology and energetic …

Assessing Distribution And Density Changes Of The Ecosystem Engineers, Rockweed And Kelp, In Narragansett Bay, Ri, Rebecca Venezia

Open Access Dissertations

Climate change and anthropogenic stressors in marine costal habitats include increased sea surface temperatures (SST) and precipitation. The impacts of these stressors can affect ecosystem engineer species, which create three-dimensional habitat space in and provide various ecosystem services that modify and maintain ecosystem resources. In Narragansett Bay, RI, USA there is anecdotal evidence that the habitat forming species of kelp, Saccharina latissima, and rockweeds, Ascophyllum nodosum and Fucus spp, are changing but few long-term studies have been conducted to verify this. We compared the historical studies from the 1960s to 2010s on seaweeds in Narraganset Bay to modern SCUBA …

Stability And Global Dynamics Of Autonomous And Nonautonomous Discrete Population Models With Stocking, Harvesting, And Cooperation, Sam Habach

Open Access Dissertations

This dissertation investigates the local and global behavior of several classes of discrete population models involving stocking, harvesting, and cooperation. The study is divided into three major manuscripts, each offering new theoretical in sights, bifurcation results, and applications to real-world data.

In Manuscript 1, we study the Beverton-Holt population models with constant and proportional stocking and harvesting, as well as sigmoid Beverton-Holt models under constant stocking and harvesting, both in autonomous and non-autonomous settings. We analyze stability and explore global dynamics using established local and global dynamics theorems, bifurcation theory, and explicit solutions when available. Special attention is given to …