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Turbulent Coherent Structures Near Coastal Capes, Marcello G. Magaldi

Open Access Dissertations

A numerical study aimed at investigating the conditions under which different flow regimes appear near coastal capes is presented. The impacts of the regimes are also quantified in terms of integral quantities like mixing, current transport and form drag. Idealized and realistic numerical simulations are run both in barotropically and baroclinically-driven systems. The realistic cases model the Western Adriatic Current (WAC) in the Adriatic Sea. In both cases, the turbulent state of the flow is controlled in first approximation by the Burger number, Bu. When a steady barotropic and geostrophic current impinges on a triangular idealized cape, vertical movements are …

Development And Applications Of Second-Order Turbulence Closures For Mixing In Overflows, Mehmet Ilicak

Open Access Dissertations

Mixing between overflows and ambient water masses is a crucial problem of deep-water formation in the down-welling branch of the meridional overturning circulation of the ocean. In this dissertation work, performance of second-order turbulence closures in reproducing mixing of overflows is investigated within both hydrostatic and non-hydrostatic models. First, a 2D non-hydrostatic model is developed to simulate the Red Sea overflow in the northern channel. The model results are compared to the Red Sea Outflow Experiment. It is found that the experiments without sub-grid scale models cannot reproduce the basic structure of the overflow. The k-ε model yields unrealistically thick …

A Human Security Population-Based Approach To Achieve Equity, Solidarity And Gender Sensitivity For The Population Living In Southwestern Bateyes Of The Dominican Republic, Eddy Nelson Perez

Open Access Dissertations

The present study was designed to contribute to the application of human security principles in vulnerable populations, using the Bateyes (sugar mill camps) from the Dominican Republic (DR) as a case study. Following the Robin Hood principle of using resources allocated for the identification and treatment of human immunodeficiency virus (HIV) as a base from which to build infrastructure for other health and human security needs, this project sought to reduce inequalities and promote equal rights in a vulnerable population living in isolated rural areas of the DR. The impact of a human security model versus non-intervention (standard of care) …

Exploring Teachers' And Black Male Students' Perceptions Of Intelligence, Patrick Anthony Williams

Open Access Dissertations

This study explored teachers' perceptions of intelligence of 11th-grade Black male students and how students themselves perceived their own intelligence in light of Howard Gardner's Theory of Multiple Intelligence. Qualitative research methods were used to gain novel understanding of the students' and teachers' feelings, and perceptions as outlined in the research questions. Two versions of ecological systems theory provided the underpinnings for the framework of this study: 1) Brönfenbrenner's Ecological Systems Theory, and 2) Spencer's PVEST (Phenomenological Variant of Ecological Systems Theory) model, which is an adaptation of the ecology model to Black students in the United States. In a …

Cancer In The Florida Hispanic Diverse Populations, Paulo S. Pinheiro

Open Access Dissertations

Cancer afflicts 1.4 million people in the United States annually. In 2007, 45.5 million Hispanics were the largest and fastest growing minority in the US. Although treated as a homogeneous group, Hispanics are different from cultural, socioeconomic and genetic perspectives. The cancer experience of Hispanic subpopulations has, thus far, been poorly described. The present dissertation focused on the descriptive epidemiology of Cancer in Hispanics in the US. We created and validated an algorithm, the Hispanic Origin Identification Algorithm (HOIA), to improve the assignment of ethnicity and Hispanic subpopulation. We applied the HOIA to the Florida incident cancer data of the …

Cancer In The Florida Hispanic Diverse Populations, Paulo S. Pinheiro

Open Access Dissertations

Cancer afflicts 1.4 million people in the United States annually. In 2007, 45.5 million Hispanics were the largest and fastest growing minority in the US. Although treated as a homogeneous group, Hispanics are different from cultural, socioeconomic and genetic perspectives. The cancer experience of Hispanic subpopulations has, thus far, been poorly described. The present dissertation focused on the descriptive epidemiology of Cancer in Hispanics in the US. We created and validated an algorithm, the Hispanic Origin Identification Algorithm (HOIA), to improve the assignment of ethnicity and Hispanic subpopulation. We applied the HOIA to the Florida incident cancer data of the …

Attractors In Dynamics With Choice, Sanja Zivanovic

Open Access Dissertations

Dynamics with choice is a generalization of discrete-time dynamics where instead of the same evolution operator at every time step there is a choice of operators to transform the current state of the system. Many real life processes studied in chemical physics, engineering, biology and medicine, from autocatalytic reaction systems to switched systems to cellular biochemical processes to malaria transmission in urban environments, exhibit the properties described by dynamics with choice. We study the long-term behavior in dynamics with choice. We prove very general results on the existence and properties of global compact attractors in dynamics with choice. In addition, …

The Role Of Spatiotemporal Heterogeneity In Water And Nutrient Pools In Everglades Plant Community Diversity And Function, Amartya K. Saha

Open Access Dissertations

Spatial and temporal heterogeneity of water and nutrient pools is closely associated with the existence of different plant communities in hydrologically-controlled ecosystems such as the Everglades. These various communities differ in their flooding and fire tolerances as well as nutrient requirements. Upland plant communities are of particular ecological significance since they have high biodiversity and provide habitat to terrestrial fauna, yet comprise less than 10 % of the total area. Restoration and maintenance of such communities requires an understanding of their water and nutrient requirements. Chapter 2 compares water source utilization in hammocks and pine rocklands on the Miami Rock …

Spatial And Feeding Ecology Of The Fer-De-Lance (Bothrops Asper) In Costa Rica, Dennis K. Wasko

Open Access Dissertations

Understanding the ways in which animals utilize space and obtain food are central themes in modern ecology. Formulating broad principles and elucidating the factors explaining such patterns are limited, however, by the availability of data from a broad range of species and systems. This problem especially true of snakes, a predator group about which even the most basic natural history data are often entirely lacking, even among abundant, widespread, and ecologically-important species. I studied the natural history and ecosystem role of one such species, the fer-de-lance (Bothrops asper) in lowland rainforest in Costa Rica. B. asper is a large, cryptic …

The Genetic Basis Of Evolved Differences In Gene Expression In Fundulus Heteroclitus, Cinda Pitts Scott

Open Access Dissertations

This dissertation explores the genetic basis of gene expression in Fundulus heteroclitus by focusing on the role of the environment and its effects on gene expression and by making direct estimates of heritability using cDNA microarrays. The second chapter describes the utility of F. heteroclitus cDNA microarrays for studies of F. heteroclitus which seek to understand the genetic variation in gene expression. Measurements of mRNA fluorescence and concentration as well as differences in sample preparation and sampling of blood from a single individual over time demonstrate that F. heteroclitus cDNA microarrays are quantitative, reproducible and consistent. The third chapter examines …

Multi-Species Influenza Models With Recombination, Brian John Coburn

Open Access Dissertations

Avian influenza strains have been proven to be highly virulent in human populations, killing approximately 70 percent of infected individuals. Although the virus is able to spread across species from birds-to-humans, some strains, such as H5N1, have not been observed to spread from human-to-human. Pigs are capable of infection by both avian and human strains and seem to be likely candidates as intermediate hosts for co-infection of the inter-species strains. A co-infected pig potentially acts as a mixing vessel and could produce a new strain as a result of a recombination process. Humans could be immunologically naive to these new …

The Co-Construction Of Self-Talk And Illness Narratives: An Hiv Intervention Case Study, Yvette Bueno

Open Access Dissertations

This case study investigates the co-construction communication patterns that emerged during an Human Immunodeficiency Virus (HIV) intervention designed to reduce negative and critical self-talk. The transcripts of eight sequential acupressure and behavioral (SAB) counseling intervention sessions between a therapist and two medically nonadherent HIV-infected women were analyzed using Giorgi's (1989, 1994, 1997, 2006) phenomeonlogical method of inquiry. The analysis revealed three major themes: "assessing the present," "reviewing the past," and "forging the future," and eight subthemes: "safe atmosphere," "disclosure," "negotiating meaning," "releasing the past," "breaking the past-to-present pattern," "reducing uncertainty," "generating options," and "projecting images." Prior to the intervention sessions, …

Transcriptional And Post-Transcriptional Regulation Of Synaptic Acetylcholinesterase In Skeletal Muscle, Carlos A. Ruiz

Open Access Dissertations

myotubesProper muscle function depends upon the fine tuning of the different molecular components of the neuromuscular junction (NMJ). Synaptic acetylcholinesterase (AChE) is responsible for rapidly terminating neurotransmission. Neuroscientists in the field have elucidated many aspects of synaptic AChE structure, function, and localization during the last 75 years. Nevertheless, how the enzyme is regulated and targeted to the NMJ is not completely understood. In skeletal muscle the synaptic AChE form derives from two separate genes encoding the catalytic and the collagenic tail (ColQ) subunits respectively. ColQ-AChE expression is regulated by muscle activity; however, how this regulation takes place remains poorly understood. …

The Mrna Nuclear Export Machinery Is Targeted By Influenza Virus And Antivirals, Neal G. Satterly

Open Access Dissertations

Proper mRNA nuclear export is essential for harmonious growth and maintenance of a cell. An effective weapon influenza virus employs to hijack a host cell is its ability to inhibit such export. Exactly how influenza virus achieves this inhibition is not fully known. Here, we demonstrate that upon infection, influenza virus degrades two nucleopore proteins (Nup98 and Nup96), which play a key role in mRNA nuclear export. Also, a main virulence factor of influenza virus (non-structural protein 1, NS1) binds directly to NXF1 and E1B-AP5, two key constituents of the mRNA export pathway (NXF1/NXT pathway) responsible for exporting bulk (~70%) …

Nanotechnology For Molecular Recognition Of Biological Analytes, Robert C. Triulzi

Open Access Dissertations

Nanotechnology is a term used to describe nanometer scaled systems. This thesis presents various nanomaterials and systems for the investigation of biologically relevant analytes in general, and in particular for their detection, decontamination, or destruction. The validation of short peptide fragments as models for protein aggregation is initially discussed through applying spectroscopic and microscopic techniques to Langmuir monolayer surface chemistry. Following this validation, the use of nanogold as a photoablative material for the destruction of aggregated protein is investigated. Subsequently, the versatility of nanotechnology is shown by investigating a different form of nanogold; namely, gold quantum dots and the interesting …

Economics Of Bluefin Tuna Aquaculture In The United States, Gina Louise Shamshak

Open Access Dissertations

This research presents a bioeconomic framework for assessing the economics of offshore bluefin tuna aquaculture production by developing a dynamic stochastic adaptive bioeconomic model of such an offshore enterprise. The bioeconomic model incorporates the biological constraints of the species, the interaction of relevant economic parameters and constraints, and stochastic sources of risk to solve for the profit maximizing behavior of a farmed bluefin tuna producer. The model identifies the optimal harvest schedule for an offshore bluefin tuna farming facility that maximizes the net present value of the operation under a variety of economic, biological and regulatory conditions. This model is …

Resistance To Northern Root-Knot Nematode (Meloidygyne Hapla Chitwood) In Lettuce (Lactuca Sativa L.), Parminderjit Kaur

Open Access Dissertations

The present study was undertaken to identify lettuce gel' plasm having resistance to M. hapla. Approximately 500 Lactuca accessions were evaluated in the greenhouse for resistance to M. hapla. Six week old seedlings were inoculated with M. hapla at 5,000 eggs per plant. Twelve weeks after inoculation data were recorded on root galling and fresh root weight. The accessions with a root galling score of two or less were considered resistant to M. hapla and were screened in a second trial. Two L. sativa accessions (PI 508476 and PI 419140) and three wild Lactuca accessions, L. saligna PI 281876, L. …

Design And Analysis Of High-Performance And Recoverable Data Storages, Weijun Xiao

Open Access Dissertations

With explosive growth of networked information services and e-commerce, data protection and recovery have become the top priority of business organizations and government institutions. In order to make data recoverable and provide high-performance storage service, we have conducted intensive research on networked storage systems. This dissertation addresses the issues related to high recoverable and high-performance storage systems. First, this thesis presents an implementation and performance evaluation of two snapshot technologies: copy-on-write and redirect-on-write snapshots. Our experimental results uncovered many interesting observations regarding the performance characteristics of the two snapshot techniques. Depending on the applications and different I/O workloads, the two …

Factors Influencing The Success Of Community-Based Marine Protected Areas In North Sulawesi Indonesia, Brian R. Crawford

Open Access Dissertations

The purpose of this research was to examine factors that influence the success of community based marine protected areas in North Sulawesi Indonesia. The research took place in North Sulawesi Province of Indonesia. A multi-methods approach was used including administration of a survey questionnaire to a random sample of household respondents, use of secondary data, key informant interviews and direct observations within the field sites. Results demonstrate that community-based management interventions and community responses are complex and varied. Progress in establishing community-based marine protected areas was related to community context and the amount and type of project interventions provided. The …

Functional Silane Based Co-Polymers For Biofunctionalization Studies, Chemical Sensing And Separations, Swapna Addagulla

Open Access Dissertations

The focus of the research reported in this dissertation has focused on two areas: (1) Synthesis of silane-containing polymers and (2) the application of these polymers to surface modification of substrates such as PDMS (for microfluidic applications), glass, quartz, silicon wafers and various nanoparticles (magnetic iron oxide, silica) for use in chemical and biological sensing and separation applications as well as in biofunctionalization of magnetic nanoparticles.

Chapter 1 of this dissertation described the preparation of a library of silane containing co- and terpolymer prepared with various substituted maleimides along with their characterization by FTIR, UV-Visible, ¹H- and ¹³C-NMR, …

Stereotype Threat And Implicit Attitudes: Implications For The Leaky Pipeline Of Women In Science, Karen E. Stamm

Open Access Dissertations

Historically, women have been under-represented in science disciplines. This phenomenon has been described as a "leaky pipeline" where fewer women advance to higher levels of the pipeline. A possible mechanism behind the leaky pipeline is stereotype threat, the fear of being negatively evaluated because of one's group membership. Stereotype threat can undermine the performance of the members of any disadvantaged group. For example, women may not perform well on science tasks because of the stereotype that "women can't do science."

This project examined whether stereotype threat negatively influences performance on an Implicit Association Test (IAT), a test that measures unconscious …

Assessing Essential Fish Habitat And Connectivity Using Otolith Chemistry And Growth Of Temperate And Tropical Fish, Ivan Mateo

Open Access Dissertations

Many shallow water habitats are vulnerable to loss or deterioration from a variety of processes, including erosion, pollution, and urbanization. Conservation of these 'nursery' habitats protects an important source of young individuals to offshore adult fish populations. The first part of this dissertation investigates whether young-of-the year (YOY) tautog Tautoga onitis, French grunt Haemulon flavolineatum, and schoolmaster Lutjanus apodus from different nursery habitats can be distinguished by chemical signatures in their otoliths. Concentrations of ten elements, as well as stable oxygen (18O) and carbon (13C) isotopes, were determined in otoliths. Chemical signatures differed significantly among fish from different nurseries (MANOVA …

Characterization Of N-Acetylglucosamine Utilization By The Lyme Disease Spirochete, Borrelia Burgdorferi, Ryan Gregory Rhodes

Open Access Dissertations

Borrelia burgdorferi is the causative agent of Lyme disease, the most common vector-borne disease in the United States. This spirochete is maintained exclusively within an enzootic cycle and alternates between a tick vector (Ixodes species) and vertebrate host. The organism has limited biosynthetic capabilities and must obtain many essential nutrients from its surrounding environment. One such nutrient is N-acetylglucosamine (GlcNAc), a component of peptidoglycan which forms the rigid layer of the microbial cell wall. B. burgdorferi can import GlcNAc as a monomer through one of several glucose transporters or as a dimer (chitobiose) through a dedicated phosphotransferase system (PTS). Despite …

Pyrethroid Resistance In The Annual Bluegrass Weevil, Listronotus Maculicollis (Coleoptera: Curculionidae), From Southern New England Golf Courses, Darryl Ramoutar

Open Access Dissertations

The annual bluegrass weevil, Listronotus maculicollis Kirby (Coleoptera: Curculionidae), has emerged as a serious pest of Poa annua L. (Poales: Poaceae) (annual bluegrass), in the Northeastern US. In 2007, topical application bioassays of bifenthrin and λ-cyhalothrin conducted on field-collected populations of L. maculicollis Kirby from eight southern New England golf courses resulted in LD50 ranges of 1.80-244.67 ng/insect and 0.52-159.53 ng/insect for bifenthrin and λ-cyhalothrin respectively. These results revealed low to high levels of resistance to bifenthrin (6.1-135.9 fold) and λ-cyhalothrin (28.7-306.8 fold), possibly due to insecticide overuse. In 2008, topical application bioassays with bifenthrin and bifenthrin plus synergists affecting …

Conservation Genetics Of Association Of Zoos And Aquariums And Wild Matshie's Tree Kangaroo (Dendrolagus Matschiei) From Huon Peninsula, Papua New Guinea, Thomas Joseph Mcgreevy Jr.

Open Access Dissertations

The Association of Zoos and Aquariums (AZA) Matschie's tree kangaroo (Dendrolagus matschiei) population is at a critical point for assessing long-term viability; they have endured a founder effect and have low mitochondrial DNA (mtDNA) diversity. The mean kinship (MK) strategy is used to preserve their genetic diversity by minimizing the overall kinship of the population; however, the MK strategy has not been evaluated in an AZA population. Wild D. matschiei is listed as endangered and genetically unique populations may warrant management as separate conservation units. My objectives were to: (i) develop molecular markers to facilitate genetic analyses, (ii) assist AZA …

Modeling And Experiments In Microchannels For The Separation And Detection Of Bacteria Using Antibody-Coated Filter And Quantum Dots, Narendra Sharma

Open Access Dissertations

Capture and detection of biomarkers for organisms is an important aspect in the design of a Lab-on-a-Chip (LOC). In this research, modeling and experiments were conducted to separate, capture and detect E. coli K12 bacteria from water samples using microchannels. Microchannels were fabricated using the soft lithography technique. The bacteria were separated from the sample and captured at a polyester filter whose surface was modified by attaching functional groups that had affinity for antibodies specific to E. coli K12. The bacteria bound to the functionalized filter were then tagged with quantum dots conjugated with E. coli K12-specific antibodies for detection …

Global Behavior Of Solutions To A Class Of Second-Order Rational Difference Equations, Sukanya Basu

Open Access Dissertations

For every choice of positive parameters α, β, γ, A, B and C, consider the two difference equations [special characters omitted] and [special characters omitted] In this thesis, it is shown that all solutions to Eqns.(E1) and (E2) converge to the positive equilibrium or to a prime period-two solution. A complete qualitative description of the global behavior of solutions to (El) with nonnegative parameters is also given in this thesis whenever prime period-two solutions exist. Furthermore, a relation is established between local stability of equilibria and slopes of critical curves of planar maps. Then this result is used to give …

Bio-Optical And Remote Sensing Investigation Of Phytoplankton Community Size Structure, Colleen Beckmann Mouw

Open Access Dissertations

This dissertation examines the optical and ecological role of phytoplankton cell size in the context of chlorophyll concentration and the presence of other optically active constituents. The first study isolates the effect phytoplankton cell size has on varying spectral remote sensing reflectance (Rrs(λ)) through the use of optical and radiative transfer models that are linked in an off-line diagnostic calculation to a global monthly numerical model. Two separate simulations of the optical model were run with cell size-dependent and cell size-independent phytoplankton absorption with all other optical constituents treated identically. The consideration of size-varying phytoplankton absorption resulted in more realistic …

Making Room For One Another: Practicing Dynamic And Designed Dialogicality In A Kindergarten Classroom, Gerri August

Open Access Dissertations

The territory of this critical ethnography lies at the intersection of democratic, transformative pedagogy and differences that made a difference in an urban kindergarten. It is an interpretation of a democratic, transformative educator responding to sociocultural differences that emerged in the classroom discourse. Often, such differences lead to otherization. This study interprets the constraints and possibilities that encouraged students to recognize and respect difference. The kindergarten classroom is interpreted in the framework of activity theory. Drawing largely on discourse analysis, this interpretation turns on the interplay between two primary elements in the activity system. The first is Zeke, the kindergarten …

Benthic Macrofauna In Narragansett Bay, Rhode Island: An Examination Of Factors Causing Variability In Community Structure, Christopher John Calabretta

Open Access Dissertations

Benthic macrofaunal communities in the upper Narragansett Bay, Rhode Island have been sampled annually since 2000 as part of the Narragansett Bay Benthic Study (NBBS). This work explored the natural and anthropogenic drivers underlying spatial and temporal variability in benthic community structure. Spatial variability in the structure of Narragansett Bay's benthic macrofaunal communities was related to the degree of exposure to anthropogenic stress. Results suggested a progression in the structure of benthic assemblages from early successional stages in the areas of Mt. Hope Bay and Conimicut Point, to an intermediate stage at the mouth of Greenwich Bay and culminating with …