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Beyond The Tip Of The Seamount: Distinct Megabenthic Communities Found Beyond The Charismatic Summit Sponge Ground On An Arctic Seamount (Schulz Bank, Arctic Mid-Ocean Ridge), H. K. Meyer, Andrew J. Davies, E. M. Roberts, J. R. Xavier, P. A. Ribeiro, H. Glenner, S.-R. Birkley, H. T. Rapp

Graduate School of Oceanography Faculty Publications

Our understanding of the benthic communities on arctic seamounts and descriptions of such communities in habitat classification systems are limited. In recent years, Schulz Bank (73°52′N 7°30′E), a seamount on the Arctic Mid-Ocean Ridge (AMOR), has become well studied but the work has primarily focused on an arctic sponge ground at the summit. This has compounded a general assumption that the most biologically interesting community is on the summit alone. With the potential threat of deep-sea mining on nearby sites on AMOR, it is crucial to form a baseline understanding of the benthic megafaunal communities not only on the summit, …

Recurring Bleaching Events Disrupt The Spatial Properties Of Coral Reef Benthic Communities Across Scales, Helen V. Ford, Jamison M. Gove, John R. Healey, Andrew J. Davies, Nicholas A.J. Graham, Gareth J. Williams

Graduate School of Oceanography Faculty Publications

Marine heatwaves are causing recurring coral bleaching events on tropical reefs that are driving ecosystem change. Yet, little is known about how bleaching and subsequent coral mortality impacts the spatial properties of tropical seascapes, such as patterns of organism spatial clustering and heterogeneity across scales. Changes in these spatial properties can offer insight into ecosystem recovery potential following disturbance. Here we repeatedly quantified coral reef benthic spatial properties around the circumference of an uninhabited tropical island in the central Pacific over a 9-year period that included a minor and subsequent severe marine heatwave. Benthic communities showed increased biotic homogenisation following …

Demersal Fish Biomass Declines With Temperature Across Productive Shelf Seas, Daniel Van Denderen, Aurore A. Maureaud, Ken H. Andersen, Sarah Gaichas, Martin Lindegren, Colleen M. Petrik, Charles A. Stock, Jeremy Collie

Graduate School of Oceanography Faculty Publications

Aim: Theory predicts fish community biomass to decline with increasing temperature due to higher metabolic losses resulting in less efficient energy transfer in warm-water food webs. However, whether these metabolic predictions explain observed macroecological patterns in fish community biomass is virtually unknown. Here, we test these predictions by examining the variation in demersal fish biomass across productive shelf regions.

Location: Twenty one continental shelf regions in the North Atlantic and Northeast Pacific.

Time Period: 1980-2015.

Methods: We compiled high-resolution bottom trawl survey data of fish biomass containing 166,000 unique tows and corrected biomass for differences in sampling area and trawl …

Holocene Climate Change Shifted Southern Ocean Biogeochemical Cycling And Predator Trophic Dynamics, Chantel I. Michelson, Michael J. Polito, Michael B. Wunder, Steven D. Emslie, Matthew D. Mccarthy, William P. Patterson, Kelton W. Mcmahon

Graduate School of Oceanography Faculty Publications

Studies of Antarctic paleo-archives have produced conflicting hypotheses on the relative impact of long-term climate change and historic exploitation of marine mammals on Southern Ocean krill predator foraging ecology. We disentangle these hypotheses using amino acid stable isotope analysis on a 7000-yr Holocene archive of Adélie penguin (Pygoscelis adeliae) eggshells to differentiate variation in diet and trophic dynamics from baseline biogeochemical cycling as drivers of the rapid decline in krill predator bulk tissue δ15N values in recent centuries. Contrary to previous hypotheses suggesting solely trophic dynamic mechanisms as drivers of this decline, we identified an abrupt decline in source amino …

Combined Effects Of Fronts, Upwelling And The Biological Pump On Organophosphate Esters In The Changjiang (Yangtze) River Estuary During Summer, Jinghua Zhang

Graduate School of Oceanography Faculty Publications

Estuarine and coastal environments are important transport pathways and regional sinks for anthropogenic pollutants. In this study, the occurrence and transport of the continuously released organophosphate esters (OPEs) was investigated together with physical and biochemical parameters throughout the water column in the Changjiang (Yangtze) River estuary during the summer. Total dissolved and particulate OPEs showed great spatial heterogeneity, with mean concentrations of 550 ± 280 ng/L in the estuary, 110 ± 270 ng/L in the front/upwelling zone, and 410 ± 450 ng/L in the continental shelf. OPE concentrations in the estuarine bottom waters were high due to massive terrestrial/sediment inputs. …

A New, Global Optical Sediment Trap Calibration, Margaret L. Estapa, Colleen Andrea Durkin, Wayne H. Slade, Christine L. Huffard, Sean P. O'Neill, Melissa M. Omand

Graduate School of Oceanography Faculty Publications

Autonomous sensors for gravitational carbon flux in the ocean are critically needed, because of uncertainties in the projected response of the biological carbon pump (BCP) to climate change, and the proposed, engineered acceleration of the BCP to sequester carbon dioxide in the ocean. Optical sediment trap (OST) sensors directly sense fluxes of sinking particles in a manner that is independent of, and complementary to, other autonomous, sensor-derived estimates of BCP fluxes. However, limited intercalibrations of OSTs with traditional sediment traps and uncharacterized, potential biases have limited their broad adoption. A global field data set spanning three orders of magnitude in …

Conflicts Of Interest In The Assessment Of Chemicals, Waste, And Pollution, Andreas Schäffer, Ksenia J. Groh, Gabriel Sigmund, David Azoulay, Thomas Backhaus, Michael G. Bertram, Bethanie Carney Almroth, Ian T. Cousins, Alex T. Ford, Joan O. Grimalt, Yago Guida, Maria C. Hansson, Yunsun Jeong, Rainer Lohmann, David Michaels, Leonie Mueller, Jane Muncke, Gunilla Öberg, Marcos A. Orellana, Edmond Sanganyado, Ralf Bernhard Schäfer, Ishmail Sheriff, Ryan C. Sullivan, Noriyuki Suzuki, Laura N. Vandenberg, Marta Venier, Penny Vlahos, Martin Wagner, Fang Wang, Mengjiao Wang, Anna Soehl, Marlene Agerstrand, Miriam L. Diamond, Martin Scheringer

Graduate School of Oceanography Faculty Publications

Pollution by chemicals and waste impacts human and ecosystem health on regional, national, and global scales, resulting, together with climate change and biodiversity loss, in a triple planetary crisis. Consequently, in 2022, countries agreed to establish an intergovernmental science–policy panel (SPP) on chemicals, waste, and pollution prevention, complementary to the existing intergovernmental science–policy bodies on climate change and biodiversity. To ensure the SPP’s success, it is imperative to protect it from conflicts of interest (COI). Here, we (i) define and review the implications of COI, and its relevance for the management of chemicals, waste, and pollution; (ii) summarize established tactics …

Occurrence And Diffusive Air-Seawater Exchanges Of Organochlorine Pesticides (Ocps) And Polychlorinated Biphenyls (Pcbs) In Fildes Bay, King George Island, Antarctica, Thais Luarte, Andrea Hirmas-Olivares, Juan Höfer, Ricardo Giesecke, Mireia Mestre, Sergio Guajardo-Leiva, Eduardo Castro-Nallar, Andrés Pérez-Parada, Gustavo Chiang, Rainer Lohmann, Jordi Dachs, Susan Bengston Nash, José Pulgar, Karla Pozo, Petra P. Pribylová, Jakub Martiník, Cristóbal Galbán-Malagón

Graduate School of Oceanography Faculty Publications

We report the levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in seawater and air, and the air-sea dynamics through diffusive exchange analysis in Fildes Bay, King George Island, Antarctica, between November 2019 and January 30, 2020. Hexachlorobenzene (HCB) was the most abundant compound in both air and seawater with concentrations around 39 ± 2.1 pg m⁻³ and 3.2 ± 2.4 pg L⁻¹ respectively. The most abundant PCB congener was PCB 11, with a mean of 3.16 ± 3.7 pg m⁻³ in air and 2.0 ± 1.1 pg L⁻¹ in seawater. The fugacity gradient estimated …

Perspective: Dimensions Of Environment And Health In Arctic Communities, Rainer Lohmann, Bonita Beatty, Jessica Graybill, Elena Grigorieva, Ketil Lenert Hansen, Anu Soikkeli

Graduate School of Oceanography Faculty Publications

In the Arctic, environment and health are linked in myriad ways. A key emphasis has been on numerous long-lived contaminants in traditional foods, particularly marine mammals, and their well-documented impacts on human, animal and environmental health (“One health approach”). More recent concerns for Indigenous communities focus on the (side) effects of the switch to a modern, processed diet, which is accompanied by a loss of tradition and emerging health impacts. Furthermore, the availability of traditional foods is increasingly threatened by the impacts of climate change, which also causes the emergence and spread of new and old diseases, such as anthrax. …

Wearing Your Conscience: Investigating How Conscious Marketing Impacts Fast Fashion Jewelry Purchases, Catherine Hodgkins

Major Papers by TMD Master of Science Students

No abstract provided.

Uri Undergraduate And Graduate Course Catalog 2023-2024, University Of Rhode Island

URI Course Catalogs Archive

This is a downloadable PDF version of the University of Rhode Island course catalog.

Variable Selection And Estimation In Bayesian Causal Mediation Analysis, Shuang Wang

Open Access Master's Theses

Causal mediation analysis has emerged as a valuable tool in various fields, allowing for decomposing total effects into direct and indirect effects. However, identifying the mediation effects relies on assumptions of no unmeasured confounding in the exposure-mediator, exposure-outcome, and mediator-outcome relationships. Moreover, there is often an interest in examining the effects of a mixture of exposures on the outcome, which poses challenges in determining the appropriate set of confounding variables. Therefore, we proposed a Bayesian mediation analysis that simultaneously selects common confounding variables associated with the two exposures, mediator, and outcome, by employing spike and slab group lasso using MCMC …

Examining The Regulation Of The Bs21 Homologs In Francisella Tularensis, Sierra Schmidt

Open Access Master's Theses

Francisella tularensis is a facultative intracellular pathogen, which relies on a network of regulation for its virulence. It contains three homologs of the ribosomal protein bS21. These three ribosomal protein homologs can independently associate with ribosomes, leading to ribosomal heterogeneity. The second homolog, bS21-2, is implicated in the positive regulation of a number of virulence proteins. Additionally, transcriptomic data indicates that bS21-2 is autoregulated. The mechanism by which this autoregulation occurs is unknown, as is the regulation of the other two homologs, bS21-1 and bS21-3. In the following chapters, I will show that bS21-1 and bS21-3 do not autoregulate their …

Development Of Polymeric Nano- And Microparticle-Based Controlled Release Platforms, Ryan Ivone

Open Access Dissertations

The success of the development of drug delivery formulations hinges upon their ability to maintain therapeutic efficacy, while simultaneously aiming to minimize off-site side effects and reduce the dosing burden often faced by patients. Localized formulations deliver therapeutics directly to the disease site and can help circumvent physiological obstacles such as the first pass effect, which remains one of the primary barriers for oral drug delivery. Barriers such as the first pass effect can drastically reduce the overall bioavailability of a formulation, potentially requiring a higher initial dose to remain therapeutically effective. However, many compounds demonstrate dose dependent side effects, …

Development And Characterization Of Nano- And Microparticles For Pulmonary Drug Delivery, Matthew Freeman

Open Access Dissertations

Pulmonary drug delivery is a rapidly growing area of interest in the field of inhalable therapeutics and provides the possibility for specialized engineered inhalable drug-loaded particles capable of improving treatment efficacy. Pulmonary drug delivery provide several advantageous when compared to other routes of administrations, as therapeutics delivered to the lungs avoid the first-pass effect of the liver, which is a major hurdle for other routes of administration. The potential for drug degradation is also decreased as the lungs have low to no enzymatic activity. Furthermore, the lungs have a large surface and are highly vascular, resulting in rapid onset of …

Pesticides, Polymers, And Pollution: Use Of Organic Chemistry To Combat Threats To Pollinator Health, Kassie Picard

Open Access Dissertations

Organic synthesis is a powerful tool that is used to solve real world problems from drug development to polymer synthesis. The basis of this work is the development and use of organic chemistry techniques to study pollinator health via the synthesis of small molecule pesticides and detection of microfibers

Pyrethroids are a class of synthetic pesticides with a wide range of agricultural, medical, and veterinary applications. These pesticides are particularly appealing due to the highly tunable molecular structure leading to selectivity towards pests and consistently low mammalian toxicity. The varroa mite, varroa destructor, is an ectoparasitic mite that infests honey …

How Does Practicing Mindfulness Relate To Consumer Willingness To Attend Events Post-Pandemic?, Gillian N. Palmer

Open Access Dissertations

A TWO ESSAY DISSERTATION EXAMINING MINDFULNESS IN THE EVENTS INDUSTRY

The restrictions and social concerns that limited social interaction during the first eighteen months of the COVID-19 pandemic had a negative impact on the multi-trillion-dollar event industry, which includes large hallmark events like festivals and concerts and business events like trade shows. In addition to the impact made to the events industry, there was a social and mental wellness impact on consumers as they learned how to live a "new norm" lifestyle. As vaccines and reductions in social distancing guidelines opened a path to return to physical, in-person events, event …

Benthic Nutrient Fluxes Response To Seasonal Hypoxia In Coastal Zones, Nicole Mucci

Open Access Master's Theses

Nutrient loading into coastal waterbodies causes excessive phytoplankton growth that increases organic matter supply to the benthos and decreases availability of dissolved oxygen. Areas of hypoxia (<2mg/l dissolved oxygen) form on seasonal timescales in coastal zones and alter microbial metabolisms in the benthic region. Nutrient efflux from sediment can serve as a major nutrient source for pelagic primary production in shallow coastal areas, creating positive feedbacks in eutrophication. Here, we examined benthic nutrient fluxes under hypoxic and oxic conditions in Greenwich Bay, RI, the Northern Gulf of Mexico, and through mesocosm manipulations using in situ benthic chambers. We also used sediment cores to further elucidate sediment nitrogen and phosphorus cycling processes. Phosphate efflux was elevated at some sites under hypoxia but not others, neither supporting nor refuting previous research that suggests phosphate movement in sediment is controlled primarily by redox conditions. In the mesocosm experiment, the sediment effluxed ammonium and consumed NOx at elevated rates under hypoxia, implying that hypoxia promoted organic matter remineralization, denitrification, and/or dissimilatory nitrate reduction to ammonium (DNRA). The effect of hypoxia on nitrogen flux in the two natural study sites was inconclusive: in August 2021, ammonium was released from sediments while in July of 2020, ammonium was consumed by sediment. Both were intermittently hypoxic periods in Greenwich Bay. Ammonium was also released during the oxic sampling period, October of 2020. In the Northern Gulf, the sediment released both nitrate and ammonium non-linearly with nearly no concentration change during the first few hours of all benthic chamber deployments but evidence of release into the chamber later in the deployments. Environmental variables, including the presence of microbial mats and macrofauna, likely created conditions for non-diffusive sediment efflux in the Gulf. In addition, the supply of labile organic matter and the strength and duration of hypoxia may have played a role in regulating sediment flux in all study sites.

Mechanisms Of Ppar-Alpha Targeted Therapy In Cholestasis: Translational Studies, Gina Gallucci

Open Access Dissertations

Cholestatic liver diseases, i.e. primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), result from a disruption of bile flow. While bile acids are crucial to maintain hemostasis, retention of bile acids becomes inherently cytotoxic and can lead to hepatocellular inflammation. Currently, the treatment options for these diseases are Ursodeoxycholic acid (Ursodiol) and Obeticholic acid. However, ~40% of patients do not respond to Ursodiol and pruritus is a limiting side effect of Obeticholic acid. Without proper treatment these diseases can progress to fibrosis, cirrhosis, and eventually liver failure. Recently, fenofibrate, a peroxisome proliferator-activated receptor alpha (PPARa) agonist has become an …

Investigating The Mechanism And Expanding The Reactivity Of Cu(I)-Catalyzed [2+2] Photocycloaddition Reactions Of Olefins, Gethmini Kasunka Jayasekara

Open Access Dissertations

Light-matter interactions can change the physical and chemical properties of a substance. The energy of photons can be used to dissociate the chemical bonds as well as to generate new bonds. The work in this dissertation is an attempt to understand how photon energy governs the formation of new carbon bonds via alkene groups in the presence of copper catalyst.

Intermolecular and intramolecular [2+2] photocycloaddition reactions facilitate the generation of cyclobutane moieties which are otherwise difficult to synthesize. Transition metal-based salts are used as catalysts to promote photocycloaddition reactions. The structure and the ring strain of a substrate can affect …

Middle Children Of History: Male-Authored Post-1960s Fiction & The Nihilism Of White Male Protagonists, Emma C. Baughman

Open Access Dissertations

This dissertation addresses the phenomenon of the white male nihilist as a recurrent character in British and American fiction post-1960. The utilization of this archetype by predominantly white male authors during this time period is symptomatic of the social, political, and economic changes that fundamentally altered the perception of the white masculine mythos in much of the Western world after the end of World War II. Because the perception of whiteness and masculinity is a primary signifier of the period’s changing value, my project approaches fictional texts of white male nihilism as objects of socio-cultural analysis that constitute a genealogy …

The Global Dynamics Of Some Rational Difference Equations Exhibiting Neimark-Sacker Bifurcation, Connor O'Loughlin

Open Access Dissertations

This thesis is presented in manuscript format. The first chapter will introduce preliminary definitions and theorems that will be used in the succeeding chapters.

The second chapter will consider the dynamics of a second-order sigmoid Beverton-Holt equation

x_n+1 = x²_n / ax²_n + x²_n-1 + d

where the parameters a and d are positive numbers and the initial conditions are non-negative numbers. For this equation, we will begin by giving a description of the local dynamics of the equation, and then will also examine the global dynamics, including an investigation into the basins …

Nano/Bio Interactions For Synthetic And Natural Nanomaterials, Zachary Shepard

Open Access Dissertations

As the field of nanotechnology advances, it is becoming more important to understand nanomaterial interactions with microorganisms. New methods for examining bacterial response to and interaction with nanomaterials are presented in the studies included here. First, bacterial response to two-dimensional nanomaterials is evaluated using a high throughput approach. Next, a calibrated water jet is used to demonstrate the effect of ship speed on biofouling release. Finally, methods of purifying biogenic nanoparticles were reviewed and evaluated for potential application at large scale. Each of these studies utilizes novel techniques for examining bacterial responses or interactions with nanomaterials or nano-enabled surfaces.

The …

Investigations Into The Adaptive Potential Of Southern Ocean Phytoplankton, Ian W. Bishop

Open Access Dissertations

Southern Ocean (SO) phytoplankton are foundational to Antarctic marine food webs and global carbon and silica cycling. As polar ocean environments continue to rapidly evolve, it is important to assess the extent to which these communities can successfully respond. Adaptation to novel conditions will be particularly important here, as shifts in biogeography to track temperature preferences are unlikely where communities already inhabit the coldest surface waters in the Southern Hemisphere. This work employs high throughput physiological and genomic methods to better understand how three important attributes, thermal trait diversity, standing genetic diversity, and repetitive genomic elements, assessed at a multiple …

Biophysical Characterization Of Phlip And Phlip-Cargo Conjugates Developed For Imaging And Therapy, Hannah Visca

Open Access Dissertations

Acidity is considered an alternative biomarker for targeting diseased tissues, such as in the acute phase of inflammation or tumors with poor prognosis. The family of pH Low Insertion Peptides (pHLIPs) are known markers of tissue acidity which provide a useful method for the diagnosis and/or treatment of disease by extracellular or intracellular delivery of imaging agents or therapeutic molecules. In my research, I employ fluorescence and CD spectroscopic techniques to understand how pHLIP's pH-dependent interactions with and insertion into the lipid bilayer of the cell membrane are affected by its sequence and conjugation with cargo and how this correlates …

Strategies Towards The Synthesis And Analysis Of Materials With Potential Environmental Impacts, Justin Pantano

Open Access Dissertations

There are a number of environmental issues that are proving to have strong effects on local populations. Chief among them is the growing concentration of contaminants in seawater, of which there are limited ways to detect in a consumer-friendly way. Contaminants such as nitrite and phosphate have strong adverse effects on aquatic life, including algal blooms and observed hypoxia in fish. The main work presented in this dissertation discusses some ways to leverage organic chemistry to develop materials to help combat these contaminants. Chapter 2 discusses the design of a novel monomer and investigates its ability to polymerize under ring-opening …

Diagnostic Brains, Experiential Minds And Metamodernism: Mcewan, Self, And Mccarthy As Case Studies, Mohamed Anis Ferchichi

Open Access Dissertations

In the wake of critical stances encompassing both modernism and postmodernism, we witness a theoretical preoccupation with how recent literary innovations position today's British fiction within the legacy of the novel form. On the one hand, postmodernism disrupted modernism's experiential phenomenology of interiority, subject, and character (what I call an experiential inflexion in critical comprehension of the form). On the other hand, what was declared "the decade of the brain" shifted some narrativization to exteriority, syndromic specifics, and reductive somaticism (what I see as a diagnostic inflexion in critical comprehension of the form). In considering today's British fiction within the …

Evaluation Of The Toxicokinetic Mechanisms Of Perfluoroalkyl Substances: Accumulation, Distribution, And Elimination, Sangwoo Ryu

Open Access Dissertations

Per- and polyfluoroalkyl substances (PFAS) are a diverse class of anthropogenic chemicals associated with several adverse health outcomes in humans. The accumulation of these PFAS have been examined over several decades, however, the elucidation of the toxicokinetics of these chemicals are still in its infancy. The distribution and elimination mechanisms of specific PFAS, notably perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), have undergone comprehensive investigation, however, there are more than 10,000 currently detected PFAS in the environment that have not been examined. It is, therefore, imperative to not only address individual PFAS but also to encompass overarching trends and correlations …

13c Labeling For Cho Cell Metabolism Tracing And Ms Based Analysis For Advanced Upstream Culture Monitoring To Support Cqa Understanding, Xin Bush

Open Access Dissertations

Monoclonal antibodies (mAbs) make up a large part of biopharmaceutical sales due to their great success in treating cancer, autoimmune, and cardiovascular diseases. Due to an increasing number of mAbs using innovative approaches in drug development, combined with changes in the drug market, there is an increased need for optimizing process intensification and quality control. Thus, a profound understanding of cellular metabolism and how this impacts the protein product’s critical quality attributes (CQA) would be of great value. Among the quality attributes of mAbs, post-translational modifications such as N-linked glycosylation are of particular importance as they affect the activity, efficacy, …

The Influence Of Nutrient Regime On Diatom Diversity And Diatom Diazotroph Associations, Samantha Patricia Setta

Open Access Dissertations

Phytoplankton are important primary producers at the base of the marine food web. Diatoms are one of the most diverse groups of phytoplankton. Compared to other phytoplankton, diatoms have higher nutrient requirements due to their larger size, and as such, their distribution is limited by nutrients. Because of this, diatoms thrive in high-nutrient ocean regions, such as coastal and high-latitude waters, where the bulk of prior diatom research has occurred. However, diatoms are also found in low-nutrient oligotrophic waters, where they can form blooms and contribute up to 30% of total annual carbon sequestration. Many studies have documented the metabolic …