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The Role Of Climate Change In The Decline Of Narragansett Bay Winter Flounder, Joseph A. Langan

Open Access Dissertations

Winter flounder (Pseudopleuronectes americanus) has historically supported productive commercial and recreational fisheries throughout its range in the northwest Atlantic. As a small flatfish that inhabits estuaries, bays, and the coastal zone, this species is vulnerable to shifting environmental conditions in many of the habitats critical to its life cycle. At the southern edge of the species range, the Southern New England/Mid-Atlantic Bight winter flounder stock entered a steep decline during the 1980s following a period of overfishing. Despite repeated reductions in harvest during the proceeding decades, the population has yet to recover. A decreasing trend in recruitment has …

The Frequent Flyer’S Guide To Migration: How Songbird Metabolism And Oxidative Status Respond To Endurance Flight And Diet Quality, Kristen J. Demoranville

Open Access Dissertations

Migratory songbirds are among the best high-performance endurance athletes on the planet and during their annual peregrinations they are particularly vulnerable to oxidative damage because they maintain relatively high metabolic rates at rest, they are able to fly for long durations while operating at 9 times their resting metabolic rate, and they rely on fats to fuel this exercise which increases reactive oxygen species (ROS) formation. The concept of evolutionary economic design of physiological systems considers such phenotypic flexibility in metabolic and antioxidant responses adaptive in that it allows birds to match the capacity of key physiological systems to prevailing …

Externalizing Problems And Hispanic/Latinx Adolescents: A Bioecological Approach, Evan Thomas Stanforth

Open Access Dissertations

Externalizing problems often develop during adolescence and cause harm to the individuals with these problems and to others in society. Hispanic/Latinx adolescents develop externalizing problems at relatively higher rates and in ways that involve systemic influences. The present study aimed to enhance clarity in this area by examining externalizing problems as a dimension of psychopathology and applying constructs of Bronfenbrenner’s bioecological theory (2005). This was attempted by examining: a) externalizing problems as a continuous spectrum, b1) relations the problems have with proximal processes of adolescent-caregiver relations, b2) and exploring differences across contexts specified as three immigration-based groups (1st generation immigrant, …

An Econometric Analysis Of The Regional Resilience Of The Kingdom Of Saudi Arabia’S Economy To Oil Shocks, Khaled Nasser S Alqahtani

Open Access Dissertations

Oil is the primary source of income for the Kingdom of Saudi Arabia (KSA); fluctuations in prices have a direct impact on KSA’s economy. Large fluctuations, usually sudden dips in oil price such as those seen in 2015 when oil prices dropped to below $40 per barrel, are leading to large deficits in KSA’s economy (on the order of $103.626 billion in 2015). These fluctuations and resulting deficits result in social and economic uncertainty and unrest. KSA is, therefore, attempting to make systematic investments in infrastructure and technology to make its economy less susceptible to fluctuations in oil prices. The …

Effects Of Psychological And Structural-Level Factors On Sexual Risk And Sti Incidence In High-Risk Men Who Have Sex With Men, Calvin J. Fitch

Open Access Dissertations

Men who have sex with men (MSM) with histories of childhood sexual abuse (CSA) are at disproportionate risk for sexually transmitted infections (STIs) and HIV. Psychological variables explain part of this; however, standing alone, they fail to account for all of the increased risk. This secondary data analysis investigates the relationship between psychological factors (PTSD and substance use), structural factors (government benefits, unstable housing and neighborhood crime), unprotected sex and STI incidence and also investigates possible moderation effects of race/ethnicity. MSM from Boston and Miami (N= 296) were recruited for a larger RCT testing the effect of Cognitive Processing Therapy …

Benthic Habitat Mapping And Its Applications To Coastal Resource Management, Monique Lafrance Bartley

Open Access Dissertations

This dissertation is comprised of three chapters focused on benthic habitat mapping of coastal waters within northeast region of the United States to support science-based regulatory and management strategies. The first chapter is entitled: Shallow water benthic habitat mapping utilizing the Coastal and Marine Ecological Classification Standard (CMECS) to establish baseline conditions post-Hurricane Sandy at Fire Island National Seashore, New York. In response to Hurricane Sandy, a benthic habitat mapping study was conducted at Fire Island National Seashore (FIIS), New York, representing one of the first comprehensive mapping efforts undertaken by the National Park Service. FIIS was of particular interest …

Exploring The Genomic Basis Of Traits Relevant To Evolution And Ecology Of Chestnuts (Castanea) Using High-Throughput Dna Sequencing And Bioinformatics., Nicholas R. Labonte

Open Access Dissertations

Introduced pests and pathogens have devastated forest ecosystems in the temperate zone; in eastern North America, introduced pests and pathogens have led to the elimination of most mature elms (Ulmus), ashes (Fraxinus), hemlocks (Tsuga) and chestnuts (Castanea) over large areas where these genera were formerly abundant and important for local ecosystems. The restoration of species affected by introduced pests and pathogens requires the development and propagation of trees that possess heritable resistance. High-throughput DNA sequencing and genomics provide opportunities for researchers to identify resistance gene candidates, screen germplasm, and develop markers for marker-assisted selection in breeding programs, with the goal …

Stenocarpella Maydis: Identification, Management, And Population Diversity, Martha P. Romero Luna

Open Access Dissertations

Diplodia ear rot (DER) has been a persistent corn disease across the Midwest, and in recent years it has become an annual problem. The objectives of this study were to i) develop a molecular assay for the identification of Stenocarpella maydis, causal agent of DER, ii) evaluate the effect of crop rotation and tillage on DER severity, iii) determine the survival period of S. maydis in corn residue at different soil depths in a corn field, and iv) identify genetic diversity among S. maydis isolates collected from the Midwestern and Southern United States. The genus Stenocarpella contains two species, S. …

Antimicrobial Resistance Patterns And Protective Effects Of Statins In Bacteremic Patients, Ajinkya Pawar

Open Access Dissertations

The significant increase in antimicrobial resistance over the past few years is a serious global public health concern, particularly as the development of new antimicrobial agents had been slow for many years. Infections with resistant organisms are associated with poor clinical outcomes and higher cost burdens. Determining antimicrobial resistance patterns can help identify problem areas and modify treatment practices to improve clinical outcomes. Additionally, identifying adjunctive therapies can also help improve clinical outcomes among infected patients. The objectives, hypotheses, methods and results of this dissertation are threefold:

Manuscript 1: The objective was to analyze antimicrobial resistance trends in E. faecalis …

Evolution Of Polyspora ( = Gordonia; Theaceae) In Sri Lanka, Liyana Arachchilage Anuradha Himashi Gunathilake

Open Access Dissertations

This dissertation examined the evolutionary relationships and evolutionary history of four endemic species of the genus Polyspora (= Gordonia) in Sri Lanka. Sri Lanka is part of the Western Ghats-Sri Lanka biodiversity hot spot with extraordinarily high species richness and endemism. In spite of its diversity and uniqueness, the biogeography of this region, especially of the flora, remains grossly understudied. My research aimed to fill this void by using the four endemic species of the genus Polyspora in Sri Lanka in phylogenetic, biogeographic, and morphological analyses. All four species of Polyspora in Sri Lanka are restricted to the wetzone of …

Indices And Ecoinformatics Tools For The Study Of Soundscape Dynamics, Luis Javier Villanueva-Rivera

Open Access Dissertations

The study of the new field of soundscape ecology presents several research avenues to explore. In the chapters in this dissertation, I have followed several of the technical and methodological areas of the study of soundscapes. In Chapter 1, I presented the current status of the study of soundscapes as well as an overview of the contributions made in this dissertation to the field. These contributions were framed in the definition of ecological informatics (Michener and Jones 2012). In Chapter 2, I developed a web-based system to manage audio archives. This system organizes thousands of audio files while collecting the …

Investigation Of The Rise Evaluation System In Montessori Schools, Susan J. Fries

Open Access Dissertations

The purpose of this qualitative study was to closely examine the RISE evaluation system and its effectiveness in non-traditional, Montessori schools. The research consisted of a qualitative study interview approach using three administrators, one who did not use the RISE evaluation system, and two who were mandated by their central office to use it; and four teachers, all who were evaluated with the RISE evaluation system. This qualitative study used the theoretical framework—hermeneutic phenomenology. Interviews with the administrators and teachers were used to collect the data. The interviews were administered in personal offices, coffee shops, and at my personal office. …

Spatial Dynamics Of Vegetated Seascapes And The Influence On Fish And Crustaceans, Rolando O. Santos Corujo

Open Access Dissertations

My dissertation adopted concepts and spatial tools of seascape ecology, the marine counterpart of landscape ecology, to understand the broad-scale structural attributes that make submerged aquatic vegetation (SAV) seascapes resilient to anthropogenic disturbances, drivers of fauna community structure, and productive fisheries habitats. My research was designed to address the relative and interrelated ecological effects of broad-scale changes in SAV habitat amount (habitat loss) and configuration (fragmentation). SAV seascapes in nearshore areas of Biscayne Bay have been subject to constant anthropogenic disturbances associated to freshwater pulses from canals over the last 50 years; thus, these seascapes served as a model system …

Energy-Efficient Information Inference In Wireless Sensor Networks Based On Graphical Modeling, Wei Zhao

Open Access Dissertations

This dissertation proposes a systematic approach, based on a probabilistic graphical model, to infer missing observations in wireless sensor networks (WSNs) for sustaining environmental monitoring. This enables us to effectively address two critical challenges in WSNs: (1) energy-efficient data gathering through planned communication disruptions resulting from energy-saving sleep cycles, and (2) sensor-node failure tolerance in harsh environments. In our approach, we develop a pairwise Markov Random Field (MRF) to model the spatial correlations in a sensor network. Our MRF model is first constructed through automatic learning from historical sensed data, by using Iterative Proportional Fitting (IPF). When the MRF model …

Quaternary Growth History Of Glover's Reef, Belize: Insights Into Reef Distribution, Ecological Change, And Pleistocene Sea Level, Noelle J. Van Ee

Open Access Dissertations

Glover’s Reef is a coral atoll located outside of the Belize Barrier Reef, 30 km from the coast of southern Belize. A single-channel seismic survey of approximately 111 km of grid lines reveals that almost 90% of the surveyed lagoon patch reefs sit on Pleistocene topographic highs. In contrast to previous theories that emphasize the role of karst processes during sea-level low stands in creating topography, records from ten rotary cores into modern reef deposits indicated that the Pleistocene topographic highs are comprised of in situ reef facies: “Reefs sit on reefs”. Although Pleistocene reef deposits formed the template for …

The Effect Of Economic And Social Conditions On The Use Of Clinical Preventive Services, Bisma Ali Sayed

Open Access Dissertations

This study examines the relationship between economic conditions and individuals’ use of clinical preventive (CP) services. CP services form the cornerstone of the national healthcare agenda, and are key in the fight to reduce morbidity and mortality in the United States. Despite this, low utilization rates remain concerning, with recent statistics indicating that rates of CP service use fall well below the targets outlined in Healthy People 2020. In the present study, I focus on individuals’ use of three CP services, influenza vaccinations, blood cholesterol screening, and endoscopic colorectal cancer screening. Broadly, I examine the effect of state-level unemployment and …

Spatial Analysis In Cancer Surveillance, Recinda Loraine Sherman

Open Access Dissertations

The burden of cancer is a significant physical, psychological, and financial toll on individuals and populations. Cancer is more common in older populations, so advances in other areas of medicine will inevitably increase the numbers of cancer patients. The development of cancer is prolonged over years which makes it difficult to identify etiologic causes. And the treatment of the disease can also be quite protracted. In the case of advanced or aggressive disease, medical treatment is sometimes reduced to a series of clinical interventions that do little to change the timeline to mortality. Currently, our most effective tool in cancer …

Impacts Of Management On Fisheries Diversity As A Factor Affecting Social Resilience In Communities Of The Southern New England Region, Tarsila Seara

Open Access Dissertations

The present research aims at examining potential impacts of fisheries management on the diversity of species exploited by fishermen in Southern New England, and examining the relationship between this diversity and the resilience of fishermen and, consequently, communities in adapting to changes in their social and physical environments. One way fishermen are able to adapt to environmental and socio-economic changes is through diversification of the catch. The current study argues that certain management plans, especially those focused on limited entry strategies, have been reducing fishermen’s adaptive flexibility, therefore reducing fishermen’s resilience and that of their communities. Two hypotheses were developed: …

A Case Study Of Student And Teacher Relationships And The Effect On Student Learning, Patricia Brady Gablinske

Open Access Dissertations

This research study explored the affective domain of teacher-student relationships using a single case study design. This single case study produced a synthesis of information that guides a classroom teacher in the development and maintenance of her relationships with her students. The resulting analysis and interpretation provided a description of major themes that developed regarding strong teacher student relationships, as well as, specific components to the interactions considered essential for the student’s learning environment.

The outcome of this study is an account of experiences and procedures that guide the development and maintenance of relationships between a teacher and her students. …

Using Molecular Tools To Elucidate Controls On Microbes Driving The Nitrogen Cycle In Marine Sediments, Shelley Marie Brown

Open Access Dissertations

Marine sediments harbor metabolically versatile bacteria whose activities can influence the cycle of nutrients on global scales. Microbial communities driving nitrogen (N) cycling are extremely diverse, thus making it difficult to identify the functional groups and elucidate controls on their activity. Denitrifiers in sediments remove significant amounts of N from the coastal ocean, while diazotrophs are typically considered inconsequential. Recently, N fixation has been shown to be a potentially important source of N in coastal sediments, however, the environmental drivers controlling this process are poorly understood. The goal of this dissertation was to identify and target the likely active denitrifiers …

Trophic Ecology Of Oxygen Minimum Zone Zooplankton Revealed By Carbon And Nitrogen Stable Isotopes, Rebecca Williams

Open Access Dissertations

Oxygen minimum zones (OMZs) are areas in which midwater oxygen concentration can be significantly lower than in non OMZ areas at comparable depths. OMZs are of great interest because of the limits oxygen availability places on life. The potential for OMZ expansion with warming of the oceans has refocused attention on the importance of these areas and their potential impacts on the global carbon cycle. The large open ocean OMZs of the Eastern Tropical Pacific and Arabian Sea are notable for their size, thickness, and the intensity of oxygen depletion (

Here, I use measurements of natural abundance carbon and …

The Importance Of The Rare: The Role Of Background Symbiodinium In The Response Of Reef Corals To Environmental Change, Rachel N. Silverstein

Open Access Dissertations

Reef ecosystems throughout much of the tropics are predicted to decline in coral cover and diversity as a result of ongoing climate change (ocean acidification, temperature increases, sea level rise), disease, pollution, and overfishing. Corals may be able to respond to some of these stressors by associating with diverse algal symbionts (Symbiodinium spp.) which vary in their physiological traits and therefore expand corals’ realized niche space. This dissertation used high-sensitivity molecular techniques to investigate the presence and functional role of "background" or "rare" Symbiodinium, which occur at low abundance, and therefore may not be detected using standard molecular methods. First, …

Quantifying The Effects Of Tidal Restrictions And Plant Invasions On Resident Fish In Atlantic Coast Salt Marshes, Kimberly Lellis Dibble

Open Access Dissertations

This research investigates the combined effects of tidal restriction and Phragmites australis invasion on habitat quality for marsh fauna across a large geographic area while evaluating the reversal of those effects through ecological restoration. We used meta-analytic tools and published literature to examine differences in the quantity, condition, and diversity of fauna in invaded and restored marshes relative to uninvaded (reference) marshes in the mid-Atlantic and in New England. In addition, we collected data for two projects designed to move beyond the collection of community data (e.g., density, richness, as included in the meta-analysis) to assess the functional response of …

Multi-Scale Patch Dynamics Of Coral Communities: A Cross-Caribbean Investigation Using A Landscape Ecology Approach, Brittany Huntington

Open Access Dissertations

The overarching objective of this dissertation was to improve our knowledge of the relationship between seascape heterogeneity and diversity of stony coral assemblages across spatial scales. Coral communities on patch reefs in three regions of the Caribbean were used as a model system to investigating this relationship because patch reef heterogeneity could be readily quantified within the seascape using remote sensing and image analysis techniques. I began with a theoretical approach, exploring the origins of observed species diversity among coral communities at increasing spatial scales. Hierarchical sampling and null models revealed that coral diversity was governed by non-random processes at …

Linking Hydroperiod With Water Use And Nutrient Accumulation In Wetland Tree Islands, Xin Wang

Open Access Dissertations

Many large terrestrial ecosystems have patterned landscapes as a result of a positive feedback system between vegetation communities and environmental factors. One example is tree island habitats in the Florida Everglades. Although they only occupy a small portion of the Everglades landscape, tree islands are important features as the focus of nutrient accumulation and wildlife biodiversity in the Everglades ecosystem. The hardwood hammock community on the elevated head of tree island habitats can accumulate high phosphorus concentration in the otherwise P-limited Everglades ecosystem. In this dissertation, I examined two hypotheses derived from the chemohydrodynamic nutrient accumulation model, which suggests that …

Community And Functional Ecology Of Lianas In The Yasuní Forest Dynamics Plot, Amazonian Ecuador, Hugo Geovanny Romero-Saltos

Open Access Dissertations

I studied the community of lianas in the Yasuní Forest Dynamics Plot (YFDP), in Amazonian Ecuador. I found that species diversity of lianas in valley habitat was higher than in ridge habitat, but liana abundance was similar. I also found that community structure (species composition and their abundances) of lianas in ridge was distinct from that in valley because of the differential distribution and abundance of certain species along the topographic gradient. In an attempt to explain this phenomenon deterministically, I took two approaches: (1) to explore if trait expression of leaf-based traits, wood specific gravity and stem growth rate …

The Effect Of Salinity Variability On The Mesozooplankton Community Of Florida Bay, Christopher R. Kelble

Open Access Dissertations

The greater Everglades ecosystem, including Florida Bay, has undergone significant anthropogenic manipulation over the past century. These actions resulted in a series of ecologically undesirable events in the Everglades ecosystem, prompting passage of the Comprehensive Everglades Restoration Plan (CERP). It is necessary to understand the variability in, and relationship between, salinity and ecology to fully evaluate the potential effects of CERP on Florida Bay. A seven-year dataset on surface salinity along with eleven-year and eight-year datasets on mesozooplankton and planktivorous fish were analyzed. Overall, mean Bay-wide salinity varied from a low of 24.2 just after the passing of Hurricane Irene …

Incorporating Recreational And Artisanal Fishing Fleets In Atlantic Billfish Management, Ayeisha A. Brinson

Open Access Dissertations

Atlantic billfish include sailfish (Istiophorus platypterus), blue marlin (Makaira nigricans), white marlin (Kajikia albida, formerly Tetrapturus albidus) and the spearfishes (Tetrapturus); these fishes are found in tropical and subtropical waters. The spearfishes include the longbill spearfish (T. pfluegeri), the Mediterranean spearfish (T. belone) and the roundscale spearfish (T. georgii). The International Commission for the Conservation of Atlantic Tunas (ICCAT) is the regional fishery management organization that conducts research to determine the condition of tuna and billfish resources and supports international cooperative management. ICCAT has determined that blue marlin and white marlin are overfished; the status of sailfish and spearfish are …

The Influence Of Habitat Quality On The Community Structure, Distribution Pattern, Condition, And Growth Of Coral Reef Fish: A Case Study Of Grunts (Haemulidae) From Antigua B.W.I, A Small Island System, Sherry Lynette Constantine

Open Access Dissertations

The goal of this research was to determine the relative quality of near shore marine areas by investigating their influence on Haemulidae community structure, distribution pattern, condition, and growth. Habitat was defined at the small spatial scale of individual habitat types such as seagrass beds, mangroves and coral reefs, and at the broader spatial scale of the interconnection of these individual habitat types within a mosaic (IHM). Ten spatial, biotic and abiotic parameters (percentage coverage of sand, mangroves, hard substrate, and seagrass, turbidity, pH, salinity, temperature, average depth, and predator density) were investigated. These environmental characteristics acted as proxies for …

A Spatial Analysis Of Colorectal Cancer In Miami-Dade County, Monique Hernandez

Open Access Dissertations

This dissertation explores the spatial patterns and place-based characteristics of colorectal cancer (CRC) late stage incidence and CRC-specific mortality in Miami-Dade County. Because CRC is the second leading cause of death among all cancers and is almost 90 percent preventable through medical screenings, investigations of CRC disparities across groups and communities are extremely relevant in the fight against cancer. This paper analyzes the geographic distribution of CRC cases in Miami-Dade County between two periods, 1988-1992 and 1998-2002 to: a) identify significant "hot spots" or clusters of disease; b) investigate associations of CRC patterns with neighborhood level characteristics such as socio-economic …