Digital Commons Network^™

Cell Stress, Protein Quality Control, And Activation Of Toxin Antitoxin Systems In Escherichia Coli, Benjamin Piraino

Open Access Dissertations

Responding to environmental stress is critical for all organismal survival, including in bacteria. One of the key bacterial responses to stress is protection of proteins within the cell, which helps to maintain proteins in a functional state. Protection of the proteome is done through a collaborative network of proteins and systems, all functioning to protect the cell. Within Escherichia coli (E. coli), three main proteomic protection systems are chaperones, proteases, and toxin-antitoxin (TA) systems. They work together, with overlapping functions, to regulate stress responses. Chaperones, such as DnaK(Hsp70) and SecB, are major regulators of protein folding within the cell, …

Associations Between Stress, Intuitive Eating, And Adiposity In A Cohort Of Midlife Women, Bridget A. Owens

Open Access Dissertations

Stress and eating behaviors can influence the health of midlife women, a population at risk for weight gain and redistribution of fat to the abdominal area related to shifts in reproductive hormones and aging. Higher stress is associated with negative health outcomes such as increased abdominal adiposity, depression, and chronic diseases such as cardiovascular disease. Women report higher stress and more emotional and physical side effects from stress than men and are more likely than men to engage in emotional eating in response to stress. Further, the desire to lose weight and the prevalence of body dissatisfaction is high among …

Stunned And Stranded: Characterizing Hypothermic Threats To Sea Turtles In The Northwest Atlantic And Enhancing Conservation By Fostering Community Engagement, Felicia M. Page

Open Access Dissertations

Over 40 years of conservation efforts have led to increases in sea turtle populations, but all species found in U.S. waters are still at risk of extinction. While the contributions of such programs like the Sea Turtle Stranding and Salvage Network and bi-national Kemp’s Ridley Sea Turtle Restoration and Enhancement Program have rescued and rehabilitated stranded sea turtles, and protected sea turtles and their nests, there are still substantial knowledge gaps that could significantly enhance current conservation programs protecting the most imperiled sea turtle species - Kemp’s ridleys (Lepidochelys kempii).

Manuscript 1 is an overview of the efforts …

Heterogeneous Ribosomes And Bs21: An Investigation Of Impacts And Mechanisms Of Altered Translation In Francisella Tularensis, Hannah Trautmann

Open Access Dissertations

Francisella tularensis is a pathogenic bacterium that requires coordinated regulation of gene expression to cause disease. In this dissertation, I explore a novel area of translation-level gene regulation in F. tularensis: heterogeneous ribosomes that preferentially translate specific mRNAs. Through mass spectrometry and immunoblotting, I find that wild-type F. tularensis ribosomes are heterogeneous with respect to the small ribosomal protein bS21 and all three bS21 homologs are able to be incorporated into ribosomes. Comparing proteomics and transcriptomics data, I determine that cells lacking one homolog, bS21-2, have genome-wide changes in protein abundance that are not explained by changes in transcript …

Associations Between Oyster Consumption And Iron, Zinc, And Cadmium Concentrations In Ghanaian Women, Alyssa Abreu

Open Access Dissertations

Background: Oysters are an excellent source of iron and zinc but may be contaminated by heavy metals such as cadmium. The micronutrient and metal content of smoked, dried oysters as well as the impact of oyster consumption on iron, zinc, and cadmium concentrations in Ghana is unknown.

Objectives: Our objectives were to 1) determine the micronutrient and metal content and health risk of dried, smoked oysters, 2) determine the associations between dietary iron intake with hemoglobin or ferritin concentrations and anemia, 3) determine the associations between oyster consumption and iron, zinc and cadmium concentrations in Ghanaian women living near the …

"Fewer And Better Doctors:" Medical School Admission In The United States, 1900-1970, Andrew Simmons

Open Access Master's Theses

Two perennial problems facing the medical profession in the United States are a lack of diversity among practitioners (both racial and socioeconomic) and physician shortages. Historically, the profession sought to control the number of physicians it produced in the nation’s medical schools while also failing to admit applicants from diverse backgrounds. This study explores the history of medical school admission and how its legacies of discrimination and deliberate restriction of places in medical schools, particularly for women and African Americans, continue to disadvantage promising applicants from backgrounds historically underrepresented in the medical profession. Sources for this study include oral histories, …

Convolutional Neural Networks For Classification Teeg And Eeg, Thao Nguyen Ngoc Pham

Open Access Master's Theses

Electroencephalogram (EEG) is a commonly used non-invasive method that acquires voltage of the brain during neural activities by using conventional disc electrodes. However, there are some fundamental limitations associated with EEG such as poor spatial resolution and signal-to-noise ratio (SNR), inaccurate data due to overlapping information, and artifact contamination. Also, the EEG software filtering solutions had the potential of distorting EEG data making the results unreliable. The tripolar electroencephalogram (tEEG) records brain signals by using the tripolar concentric ring electrodes (TCRE). Based on the surface Laplacian algorithm, signals recorded from TCRE overcome the limitations of EEG. tEEG has better SNR …

Impacts Of Seasonal Variations On Phytoplankton Growth And Grazing In Narragansett Bay, Andria M. Miller

Open Access Master's Theses

Primary production by phytoplankton is essential to global biogeochemical cycles and is the base of the aquatic food web. One of the major impacts on phytoplankton production in the global ocean is grazing by microzooplankton. While there are well known factors (e.g., light availability, nutrients, and temperature) that impact phytoplankton abundance and distribution, factors that drive microzooplankton grazing pressures are more poorly constrained. Phytoplankton primary production is high in temperate estuaries, and these ecosystems are subject to large seasonal variations in abiotic factors such as temperature and biotic factors such as plankton assemblages, making them an ideal area to study …

Seafood Consumption During Harmful Algal Blooms: The Impact Of Information Regarding Safety And Health, Andrew Bechard, Corey Lang

Environmental and Natural Resource Economics Faculty Publications

Harmful algal blooms (HABs) can cause massive fish kills all over the world. However, some commercially caught species are safe to eat. The fish safe for consumption are vastly different from the fish that wash up on shore. Prior research finds this difference in edibility is mostly unknown by consumers, and that the misperception of unhealthy and unsafe fish is the dominant paradigm. To date, there has been minimal research on the effect of disseminating this information regarding seafood health to consumers, and how consumption habits would change during a bloom. We implement a survey that presents respondents with information …

Classification Models For Predicting Mouse Spinal Motoneuron Physiological Type Based On Their Electrical Properties, Reuben Mawuena Kwadzo Ahorklo

Open Access Master's Theses

Accurate prediction of mouse spinal motoneuron physiological types based on electrical properties faces challenges due to missing data and imbalanced class distributions. Technical difficulties, physiological variations, and experimental issues contribute to data gaps in electrophysiological recordings. Imbalanced class distributions arise from the rarity of certain motoneuron types. The resulting risk of biased or unreliable classification models hampers their utility in motor control studies. Thus, we claim that the electrical properties of mouse spinal motoneurons can be accurately predicted and classified based on specific, measurable features.

This study focuses on two classification models, a multinomial logistic regression (MLM) and a Random …

An Evaluation Of Object Detection Algorithms Applied To Oceanographic Midwater Imagery, Charlotte A. Debossu

Open Access Master's Theses

Object detection algorithms have emerged as powerful tools in various domains, yet their application to oceanographic images remains in its early stages. Particularly, the use of stereo camera systems for capturing images of macroscopic marine organisms is still considered novel imagery. Therefore, it is critical to understand how well deep learning algorithms perform in classifying marine organisms in these types of images. This thesis aims to contribute to the nascent literature on this task in the context of stereo camera imagery. The study evaluates the classification performance of two prominent deep learning models, YOLOv5 and ResNet50, when applied to images …

The Role Of Culture In The Association Between Family Disapproval Of Substance Use And Substance Use Among American Indian Adolescents, Rachel Girard

Open Access Master's Theses

Introduction: Substance use among American Indian (AI) adolescents is a major health concern in Indigenous communities due to increased rates of earlier use, heavier use, and increased risk for negative outcomes related to substance use. Primary Socialization Theory (PST), which accounts for how various family and peer relationships and the strength of these relational bonds influence adolescents’ substance use, can be used to understand how relational factors influence adolescent substance use, with family being especially important and influential in AI communities. Another important aspect within AI adolescents, especially for those living on or near reservations, is culture. Researchers have …

Identification Of A Fungal Pathogen Of Invasive Swallow-Worts And Exploration Of The Implications For Hypena Opulenta, A Biocontrol Agent Of Swallow-Worts, Alexandra Johnson

Open Access Master's Theses

Two species of invasive swallow-worts (Vincetoxicum nigrum and V. rossicum) have become problematic in unmanaged areas and agricultural settings in the Northeastern United States. Traditional methods of mechanical and chemical control are inadequate or unfeasible to implement so in 2017, the defoliating moth Hypena opulenta was approved for release in the United States for biological control of swallow-worts. Since 2017 the URI Biocontrol Lab has been releasing and studying the establishment of the species in Rhode Island, Massachusetts, and Connecticut. In 2018 a fungal pathogen was observed infecting V. nigrum plants at H. opulenta release sites. To …

Improving Quality: Exploring Ceramic Water Filters In Developing Communities, Hem Kumar Pokharel

Open Access Dissertations

The main objectives of this dissertation were to determine the underlying factors involved in the ceramic water filter (CWF) manufacturing and assist in quality control of the CWFs using peer reviewed articles, empirical models, and statistical procedures. First, the progress, bias and gaps in the ceramic filter research were identified based on the peer reviewed articles published after 2011. Second, flow rate (FR) and nominal pore diameter (NPD) values as parameters were used to predict the microbial removal of CWFs. Two empirical models (flow rate model, FRM, and nominal pore diameter model, NPDM) were developed based on the log removal …

Signature Of Energetic Materials Under Pyrolysis And Ambient Conditions, Athina Kominia

Open Access Dissertations

Law enforcement and military personnel must be prepared to deal with explosives, unidentified chemicals, and even chemical warfare agents. This is a vast problem space. The included studies examine issues with characterization, mitigation, and disposal of energetic materials.

Among oxidizers those containing the ammonium cation have the potential of self-oxidization, making them of special hazard. We have examined ammonium nitrite and ammonium chlorate, two ionic compounds with well-known hazard potential, and compare their explosive performance with related materials. A novel protocol for assessment of explosivity on the gram-scale was employed.

Law enforcement and military personnel must deal with scenarios where …

Underlying Mechanisms Of Ubiquitin Specific Peptidase 2 Isoforms Regulation In Hepatocellular Carcinoma By The Farnesoid X Receptor Signaling Pathway, Winifer M. Ali

Open Access Dissertations

Hepatocellular carcinoma (HCC), or liver cancer, is the sixth most common cancer worldwide, and the third leading cause of cancer-related deaths. In 2023, an estimated 41,210 new HCC cases and 29,380 deaths have been reported in the United States with an overall 5-year relative survival rate of 20.8%. It has been predicted that by 2025, there will be more than one million cases of HCC globally. Unfortunately, there are limited effective treatments and current treatment options available are invasive and burdensome. HCC patients are usually diagnosed at the late stages of liver cancer when the only viable treatment options are …

Femtosecond Time-Resolved Coherent Raman Spectroscopy Of Equilibrium Phonons In Cubic Perovskites, Jeremy Sylvester

Open Access Dissertations

Essential to green energy technologies are new materials for high-power electronics, especially wide-bandgap semiconductors such as Barium Stannate (BSO) and Strontium Titanate (STO) which promise outstanding performance in high power transistor applications. Design and performance of these materials relies on detailed knowledge of basic physical parameters, including charge-carrier mobility. The mobility values can be as high as 500 cm2/Vs for electron concentrations >1x10¹⁹ /cm³ provided that the effect of impurity scattering is reduced using special doping techniques. In this case, the inelastic carrier-phonon scattering is the only mechanism that strongly affects the mobility as the polar optical (LO) …

Dynamics Of Non-Autonomous Discrete Systems With Applications To Evolutionary Dynamics, Susan Trolle

Open Access Dissertations

This dissertation focuses on difference equations that are of a certain type, non-autonomous competitive and cooperative systems. Previously, systems of this nature were investigated for the single species model. Here, this investigation extends to the case of two species or more, corresponding to a two dimensional system all the way to an n dimensional system. The purpose is to establish global attractivity results for these systems through a method using difference inequalities along with Northeast and Southeast partial ordering for competitive and cooperative systems, respectively. The non-autonomous case of some systems, established and well-known, are discussed for purpose of comparing …

Detection Of Coastal Phytoplankton Taxonomy, Morphology And Optical Signals With Machine Learning And Time Series Analysis, Virginie Sonnet

Open Access Dissertations

Phytoplankton are microscopic organisms crucial in the food web, primary production, and carbon export. Their abundance and diversity changes also influence the evolution of marine ecosystems and global biogeochemical cycles. In addition to extensive taxonomic diversity, phytoplankton can harbor different sets of photosynthetic pigments and display a wide range of size, morphologies, and functional traits. These particularities have led phytoplankton monitoring and phytoplankton dynamics studies to develop in many forms. Satellite remote sensing, light microscopy, and more recently particle imaging, are among those. However, they not only have widely different sampling resolution and taxonomic precision, but also target different properties …

Development Of Localized Drug Delivery Strategies For The Treatment Of Cancers And Infectious Diseases, Weizhou Yue

Open Access Dissertations

Difficult-to-treat human diseases and disorders such as brain cancer and posterior segment eye diseases greatly threaten human health and quality of life. However, the presence of physiological barriers such as the blood-brain barrier (BBB), cornea, and the blood-retinal barrier, renders these organs highly impervious to most therapeutics. As a result, most therapeutics administered systemically have low therapeutic efficacy even with high doses and are often associated with systemic side effects and/or toxicity. Localized drug delivery strategies such as injectables/implants, or locally-acting dosage forms, can circumvent physiological barriers and directly introduce therapeutics to the site of action to improve bioavailability, and …

Home Health Care Nurses’ Experiences And Perceptions Of Providing Care To Older Adults During The Covid-19 Pandemic: A Qualitative Descriptive Study, Joan R. Dugas

Open Access Dissertations

Home health care nurses were essential front line healthcare providers during the COVID-19 pandemic in the United States. Research in this area has primarily focused on the experiences of nurses in the acute and long-term care settings. This study aims to: (1) gain an understanding of the subjective experiences and perceptions of home health care nurses providing care to OAs during the COVID-19 pandemic and (2) elucidate aspects affecting the care provided to OAs during the COVID-19 pandemic.

Twenty nurses were interviewed between July 2022 and September 2022. The interviews were semi-structured and were analyzed using reflexive thematic analysis. Four …

Photochemical And Photophysical Dynamics Of The Aqueous Ferrate(Vi) Ion, Cali Antolini

Open Access Dissertations

Ferrate(VI) has been suggested as a ‘green’ alternative to current oxidation and disinfection methods used in water treatment, especially in combination with ultraviolet light. UV-activation of the ferrate salts has been shown to improve the efficiency of treating water due to the generation of highly oxidizing Fe(V) and Fe(IV) species. However, the incomplete understanding behind the nature of these intermediates, the mechanisms by which they form, and their roles in downstream oxidation reactions have limited the full-scale use of ferrate salts in facilities. Our goal is to advance the engineering of UV/ferrate(VI)-based water treatment processes by gaining a better understanding …

Advancing Nanopore Characterization Of Carbohydrates With Chemical Synthesis And Machine-Learning, James Thomas Hagan

Open Access Dissertations

The work presented in this thesis covers advancements made in carbohydrate analysis, a topic relevant for pharmaceutical testing, medical diagnostics, food adulteration analysis, and numerous other glycomics-related purposes. While carbohydrates have been extracted and commodified by humans for several millennia,^1,2 and their associated chemical identity and structural motifs have been known for over a century,^3,4 reliable and readily available methods for full characterization of this prevalent and naturally occurring group of molecules are lacking and under-developed. Conventional methods of analysis show promise but are constrained by several obstacles to overcome. This thesis work answers a still-relevant 2012 call …

Experiences Of White Women Graduate Students In A Diversity And Inclusion Badge Program At A Predominantly White Institution In A Time Of Whitestream Racial Reckoning, Stefanie Argus

Open Access Dissertations

The purpose of this study was to explore how white women engaged with interrogating whiteness, race, and racism after completing a multi-session diversity program designed for graduate students. This qualitative research project tends to the following research question: What are the lived experiences of white women who complete a diversity and inclusion program for graduate students?

For this research project, white women who are graduate students participated in in-depth, semi-structured interviews. Using critical whiteness theory, a feminist research framework, and interpretive phenomenological analysis, this study identified commonalities in experiences among participants (Creswell & Poth, 2018; van Manen, 2014). As is …

A Study Of The Structure-Activity Relationships Of Carcinogenic Protein- And Dna-Binding Chemicals, Alicia M. Crisalli

Open Access Dissertations

Chapter 1

Chemical contaminants in our environment may interact with macromolecules such as proteins and DNA in our bodies and have the potential to disrupt normal biological processes, leading to diseases such as cancer and metabolic conditions. Elucidation of these mechanisms, particularly the relationship between their structure and subsequent biological outcomes, is paramount to mitigating the harm associated with human exposure to such contaminants. It is also an important tool in the drug design/discovery process. This introductory chapter shall serve as background knowledge for readers unversed in the field, outlining several families of persistent chemical contaminants known to cause cancer …

Flux To Flow: A Clearer View Of Earth’S Water Cycle Via Neural Networks And Satellite Data, Albert Eric Larson

Open Access Dissertations

Earth’s weather and climate changes dynamically, and humans must monitor the evolution of our environment or fail to plan and adapt. Water is our most valuable resource, and as such it is of the utmost importance to have a continuous view of its movements as water cycles over, in, and under land, in the atmosphere, and in the sea. One way that we observe the water cycle is with satellite measurements. Unfortunately, the resolution of these instruments is typically too coarse to visualize many transient phenomena of interest. If their vision is fine enough, the instrument captures only a small …

Pelagic-Benthic Coupling In The Gulf Of Maine: Multidecadal Molecular Isotope Records Of Zooplankton And Deep Sea Corals Bioarchives, Catherine Nowakowski

Open Access Dissertations

The export of organic matter from the surface to deep ocean has major implications for global biogeochemical cycles, the transfer of energy across food webs, and the sequestration of carbon through the biological pump. Therefore, understanding the physical and biological conditions that control these processes is important to understanding pelagic-benthic coupling and resulting controls on ocean productivity, fisheries production, and Earth’s climate regulation. Equally important is consideration of and collaboration with diverse audiences that need to understand this information to make scientifically informed decisions about climate and environment policies that come from this research. Despite the importance of this knowledge, …

Form And Function Of The Lateral Line System In Three North American Fishes: Development, Evolutionary Insights, And Impacts Of Climate Change, Aubree E. Jones

Open Access Dissertations

In addition to the sensory modalities familiar to humans (vision, hearing, smell, touch and taste), fishes have a flow-sensing system that detects local abiotic and biotic water flows called the lateral line system. The neuromast receptor organs of the lateral line system detect hydrodynamic stimuli and are located either on the skin (superficial neuromasts) or within pored, bony canals associated with the dermatocranial bones (canal neuromasts) or scales. In Manuscripts 1 and 2, the development of the cranial lateral line system in brook trout and how climate change impacts the development of this system are described. The lateral line in …

Nanoscale Electrochemistry At Liquid/Liquid Interface For Biomedical And Energy Applications, Surendra R. Puri

Open Access Dissertations

The charge transfer across the liquid/liquid interface has been playing a crucial role in many biological and energy-related systems such as drug permeation through-bacterial membrane, ion or electron transfer through metal-reducing bacteria in microbial fuel cells (MFCs), and metabolic interaction in commensal bacterial species related to human health. Primarily, direct probing of these phenomena in situ is needed for more realistic fundamental analysis, thereby solving the problem related to public health and renewable energy generation. The interfacial CT in these systems mainly involves redox-inactive species that cannot be detected with conventional metal electrodes. Herein, the liquid/liquid interface is applied as …

A Ten-Fold Solvent Kinetic Isotope Effect For The Nonradiative Relaxation Of The Aqueous Ferrate(Vi) Ion, Cali Antolini, Danielle J. Jacoby, Sophia M. Tiano, Christopher J. Otolski, Gilles Doumy, Anne Marie March, Donald A. Walko, Joseph E. Goodwill, Dugan Hayes

Civil & Environmental Engineering Faculty Publications

Hypervalent iron intermediates have been invoked in the catalytic cycles of many metalloproteins, and thus it is crucial to understand how the coupling between such species and their environment can impact their chemical and physical properties in such contexts. In this 2 work, we take advantage of the solvent kinetic isotope effect (SKIE) to gain insight into the nonradiative deactivation of electronic excited states of the aqueous ferrate(VI) ion. We observe an exceptionally large SKIE of 9.7 for the nanosecond-scale relaxation of the lowest energy triplet ligand field state to the ground state. Proton inventory studies demonstrate that a single …