Digital Commons Network^™

Using Lagrangian Coherent Structures To Study Coastal Water Quality, Laura A. Fiorentino

Open Access Dissertations

The accumulation of pollutants near the shoreline can result in low quality coastal water with negative effects on human health. To understand the role of mixing by tidal flows in coastal water quality, we study the nearshore Lagrangian circulation of four recreational beaches in Miami, FL, who, despite close proximity, have varying microbial levels. Specifically, we reveal Lagrangian Coherent Structures (LCSs), i.e., distinguished material curves which shape global mixing patterns and thus act as skeletons of the Lagrangian circulation. We show how these material curves, which shape circulation and mixing patterns, can be used to explain the incongruous states of …

Design Of Endothelial Progenitor Cellular Constructs For Therapeutic Angiogenesis Applications, Ximena Vial

Open Access Dissertations

The goal of therapeutic angiogenesis is the development of functional and mature vasculature by combining biological and physical cues that mimic the native extracellular matrix. In this study we evaluated if immobilizing vascular endothelial growth factor (VEGF) gradients and SDF-1α on gelatin nanofibrous scaffolds with different fiber orientations (i.e. random or aligned) influence the angiogenic potential of endothelial progenitor cells (EPCs) and human umbilical vein endothelial cells (HUVECs). Both cell types successfully adhered onto gelatin B scaffolds. VEGF gradients alone or combined with SDF-1α as well as fiber orientation had a pronounced effect on cell behavior, morphology and orientation. Cells …

“Doing Business:” The Changing Shape Of Grass Roots Ngos In Haiti, Jessica Covell

Open Access Dissertations

This study provides an in-depth look at a NGO in Haiti that is attempting to generate some of its own revenue as opposed to relying solely on donor support. This case may prove to be a watershed and represent a new paradigm in development. The creation of micro-businesses and support for the state show signs of creating a more long term, sustainable solution to sanitation needs in Haiti. While the success or failure of this venture falls outside the scope of this study, it identifies emerging trends that may support the venture. The study concludes that while there is a …

Spatio-Temporal Visual Information Analysis For Moving Object Detection And Retrieval In Video Sequences, Dianting Liu

Open Access Dissertations

The development of the Internet makes the number of online videos increase dramatically, which brings new demands to the video search engines for automatic retrieval and classification. We propose an unsupervised moving object detection and retrieval framework by exploiting and analyzing spatio-temporal visual information in the video sequences. The motivation is to use visual content information to estimate the locations of the moving objects in the spatio-temporal domain. Compared with the existing approaches, our proposed detection algorithm is unsupervised. It does not need to train models for specific objects. Furthermore, it is suitable for the detection of unknown objects. Therefore, …

Haitian Parents' Experiences With The Iep Process And Their Involvement With The Special Education Program, Margarette Mahotiere

Open Access Dissertations

Current literature and recent legislation advocate parental involvement in education as ‘best subsequent reauthorizations practice.’ The Individuals with Disabilities Education Act (IDEA) Amendment of 1997 and its promote parental participation in the special education process by requiring schools to consider parents as equal partners in the development of the Individualized Education Plan (IEP) for students with disabilities. However, parents have reported the process as stressful and confusing. Prior research revealed barriers that marginalize culturally and linguistically diverse (CLD) parents to passive roles in the process. Using qualitative methods, this study focused on Haitian parents’ participation in both the IEP process …

Bridging Academic Discourse For Emergent Bilingual Preschoolers: A Spanish-English Dual Language Teacher's Instructional Practices And Extratextual Talk During Shared Readings Across Two Different Genres And Languages, Sabrina F. Sembiante

Open Access Dissertations

This qualitative case study examines the nature of a dual language preschool teacher’s instructional practices and extratextual talk during shared-book reading practices with two different genres of books in Spanish and English. Specifically, I explore the interpersonal, ideational, and textual features of one teacher’s talk in English- and Spanish-language medium book reading activities as she shares and discusses a storybook and a nonnarrative informational book with her emergent bilingual preschool students. The study is guided by the following research questions: (1) How are teachers’ instructional and discourse practices functional for interacting across different genres and in different languages? (a) What …

An Inverse Relationship Between Resistance To 2-Deoxy-D-Glucose And Glucose Starvation In Tumor Cells Under Normoxia, Katherine Beth Philips

Open Access Dissertations

A distinguishing feature of tumor cells is their upregulation of glucose metabolism. This metabolic change from oxidative phosphorylation to aerobic glycolysis creates a selective window that can be exploited for anticancer therapy. Here we investigate mechanisms by which pancreatic cancer cells respond to therapeutic (2-deoxy-D-glucose, 2-DG) and physiologic (glucose starvation, GS) forms of glucose restriction. 2-Deoxy-d-Glucose (2-DG) is a sugar analog of both glucose and mannose and thus has established activities inhibiting glycolysis and interfering with glycosylation, respectively. Due to 2-DG’s dual functions, it has classically been thought of as a glucose deprivation mimetic. Additionally, these roles render 2-DG an …

Openness And Closure In Modernist Cinema: Antonioni/Resnais/Haneke/Martel, Oscar Jubis

Open Access Dissertations

Narrative exposition evokes questions about characters and events. A narrative opens gaps when information necessary to interpret the plot has yet to be offered. Some questions perform what Barthes calls primary or “hinge” functions. Narratives revolve around these presiding questions or gaps while secondary questions serve complementary purposes. The opening of gaps and the timing of their closing are the means by which narratives incite our curiosity, foment our interest, and hold our attention. Most narratives aim to achieve resolution and grant a sense of closure by filling the gaps with sufficient certitude. A degree of ambiguity is present in …

Order Fitting Policies For Service Systems With Pricing And Inventory Decisions, Salvador Romo-Fragoso

Open Access Dissertations

The present work is the foundation for our line of research, looking for policy solutions for: order acceptance, capacity management with interruptions, pricing, and trade-offs between different assets. The first model represents an organization choosing order fitting and pricing policies for a service company selecting between deals and regular jobs with poisson arrivals. The prices for regular jobs are exogenous, whereas winning the deals depends on pricing bids. We derived and compared optimal pricing for two distinct order acceptance policies under a setting where the server had no queue. We investigated the impact of the system parameters on the optimal …

Association Affinity Network Based Multi-Model Collaboration For Multimedia Big Data Management And Retrieval, Tao Meng

Open Access Dissertations

With the rapid development of smart devices and ever-increasing popularity of social media websites such as Flickr, YouTube, Twitter and Facebook, we have witnessed a huge increase of multimedia data. Recently, social media technology and big data have converged to provide rich content on what happens around the world via texts, images, videos, audios, etc. Given the enormous volumes of multimedia data, efficient and effective retrieval of relevant information according to users’ needs poses great challenges for traditional text-oriented storage and retrieval systems. Since manually annotating and managing the huge amount of information have become infeasible, data-driven approaches have received …

The Influence Of Increased Co2 On Early Developmental Stages Of Cobia, Rachycentron Canadum, Dwight A. Ebanks

Open Access Dissertations

Projected increases in atmospheric CO2 and the resulting decrease in oceanic pH over the course of the 21st century warrant studies on the effects of these changes on marine teleosts. The goal of this dissertation was to assess the impact of projected changes in CO2 on the early physiological dynamics and development of cobia, Rachycentron canadum. Spermatozoa respiration rates displayed a non significant decrease from 1.0 + 0.2 nmol O2/mL semen•sec + S.E. at 380 ppm CO2 to 0.7 + 0.1 nmol O2/mL semen•sec + S.E. at 800 ppm CO2. Spermatozoa velocity decreased from 22.1 + 0.5 to 14.9 + …

Home Is Always Calling: Determinants Of Civic Participation Among Zimbabwean Immigrants In Cape Town, South Africa, Rumbidzai R. Mufuka

Open Access Dissertations

This research project examines factors that have influenced community engagement among immigrants from Zimbabwe living in Cape Town, South Africa. A case study of PASSOP (an immigrant rights organization in Cape Town) tests existing theories on civic participation through interviews with immigrants, knowledgeable informants and activists. The study identifies reasons for leaving Zimbabwe and legal status in South Africa as factors that influence why undocumented immigrants participate in or withdraw from civil society in Cape Town. The results indicate that the conditions of the country of origin and the related reasons for leaving—political and economic degradation in Zimbabwe—heavily influence the …

Lightweight Moral Realism: Objectivity And Reasoning Without Heavyweight Facts, Mark Douglas Warren

Open Access Dissertations

In this dissertation, I develop a non-representational approach to metaethics that avoids the ontological and epistemic problems that traditional realist views face: accounting for the nature of moral facts and our knowledge of these facts in a way that comports with naturalism. According to expressivism—the most popular non-representational account in contemporary metaethics—moral claims don’t aim to represent moral facts or properties, but instead function to express our non-cognitive attitudes like approval or disapproval. This is a promising approach, but the view has substantial difficulties accounting for important features of moral discourse, like objectivity and complicated moral reasoning. I develop an …

The Mechanisms Of Synaptic Maintenance, Shaoyun Zang

Open Access Dissertations

Synapses are specialized cell-cell contacts where signals are reliably transduced from a neuron to its target cell in a regulated manner. Structurally, synapses are comprised of the pre- and post-synaptic terminals, and the synaptic cleft. Within each of these compartments is a complex network of molecular machinery, the components of which require constant turnover and “maintenance” to ensure a consistent relay of information. In neurodegenerative diseases, such as Alzheimer’s (AD), Parkinson’s (PD), and prion-related diseases, synaptic degeneration is often an early event associated with disease severity, which is evinced by the degree of cognitive decline. A dysfunction of synaptic maintenance …

The Impact Of Natural And Anthropogenic Climate Variability On Tropical Cyclone Tracks, Angela Joy Colbert

Open Access Dissertations

To examine the impact of natural and anthropogenic climate variability on tropical cyclone (TC) tracks, a comprehensive analysis is conducted examining changes in TC tracks from changes in the large-scale steering flow and TC genesis for different climate scenarios. A Beta and Advection Model is used to create tracks under the different climate scenarios, which are then analyzed focusing on each contribution from changes in the large-scale steering flow and TC genesis separately and as a combined impact. Two experiments are conducted; the first examines potential changes in TC tracks due to anthropogenic climate change in the North Atlantic and …

The Role Of Algal Symbiont Community Dynamics In Reef Coral Responses To Global Climate Change, Ross Cunning

Open Access Dissertations

The continued growth and survival of reef-building corals is essential to sustain the goods and services provided by coral reefs, worth billions of dollars annually. However, warming oceans are causing more frequent and severe episodes of coral bleaching, the breakdown of symbiosis between corals and their algal symbionts (Symbiodinium spp.), which threatens corals’ survival unless they can adapt or acclimatize. One way that corals may increase their thermal tolerance is by associating with different Symbiodinium types. Changes in partner abundance may also have functional consequences, but these symbiont dynamics are poorly understood. This dissertation aims to provide a clearer understanding …

The Effect Of 10-S Maximal Sprints Performed Prior To And Immediately Following Moderate Intensity Exercise On Glucoregulation Of Individuals With Type 1 Diabetes, Jennifer Maher Raeburn

Open Access Dissertations

Objective: To examine the efficacy of a 10-s maximal sprint performed immediately prior to and following a 40-min, moderate-intensity bout of exercise, as a means of maintaining plasma glucose concentration during both exercise and 120 min of recovery in those with type 1 diabetes mellitus (T1DM). Research Design and Methods: Seven moderately active males with T1DM performed a continuous graded exercise test on a cycle ergometer to determine peak power output (Wpeak). Subjects then reported to the laboratory on two separate occasions after an overnight 8-h fast and either rested (CON) or performed a 10-s maximal effort sprint (150% Wpeak) …

Towards On-Site Detection Of Nucleic Acids For Pathogen Monitoring, Daohong Zhang

Open Access Dissertations

As a leading cause of death in developing countries and a persistent problem elsewhere, pathogenic organisms are as ubiquitous as they are dangerous. Significant worldwide resources are directed toward their detection and eradication, leading to a broad coalition of government agencies, healthcare providers, academic researchers, and food manufacturers dedicated to providing the best-available prevention strategies for mitigating exposure risk. At the forefront of this effort is the field of pathogen detection. Our work directly addresses the current lack of simple, rapid, sensitive, and selective pathogen detection methods needed for frontline intervention in the most at-risk populations. To begin, we focused …

Integrated Theoretical And Computational Approaches To Study Hydrolysis And Aggregation Of Biomolecules, Mehmet Ozbil

Open Access Dissertations

In this thesis, we have focused on the following two projects: (1) mechanisms of peptide hydrolysis, and (2) aggregation of biomolecules. A plethora of theoretical and computational techniques; quantum mechanics, molecular dynamics, and molecular docking have been employed to accomplish the goals of these projects. The selective hydrolytic cleavage of the extremely stable peptide bond (-(O=)C-NH-) of peptides and proteins by enzymes and their analogues is required in a wide range of biological, biotechnological and industrial applications. In the first project, we have elucidated the mechanisms of peptide hydrolysis by non-metallic (beta secretase (BACE)) and metallic (insulin degrading enzyme (IDE) …

Human Recombineering, Melvys Valledor

Open Access Dissertations

Genome editing by homologous recombination (HR) is centrally important for functional genomics, making disease models, bioengineering and for gene therapy. Viral HR relies on a SynExo complex comprised of an exonuclease and a synaptase. Genome editing by the phage lambda synaptase Beta approaches HR rates of 10% in E. coli using ssDNA-mediated Recombineering but is much less efficient in mammalian cells. SynExos are common to dsDNA viruses that infect a variety of hosts and their mechanisms are conserved, suggesting that direct genome Recombineering can be extended beyond bacteria. Our hypothesis is that co-evolution of viral SynExo recombinases with host proteins …

Ethics And Fiction: Imaginary Evil And Aesthetic Value, David Michael Hurlburt

Open Access Dissertations

Many fictional works aim to amuse audiences with accounts of immoral characters engaging in evil deeds. A number of positions have emerged to determine to what degree, if any, a work’s treatment of unethical events shapes its aesthetic value. In this dissertation I will evaluate four existing positions and advance my own for consideration, empathic autonomism. I argue that it is not unethical for audience members to enjoy imaginary immoral acts and I will show how this affects various stances. I will present objections to rival views and argue that a fictional work’s ability to allow audiences to empathize with …

Masonry Walls Strengthened With Fabric-Reinforced Cementitious Matrix Composite Subjected To In-Plane And Out-Of-Plane Load, Saman Babaeidarabad

Open Access Dissertations

A natural evolution of ferrocement has been the replacement of the reinforcing steel with new composite materials. Not only has this addressed the issue of possible durability problems associated with steel corrosion, but has opened the possibility of using thin-section cementitious products as repair materials. Fabric-reinforced cementitious matrix (FRCM) is a class of composite systems that has recently emerged as an alternative to traditional retrofitting methods like fiber-reinforced polymers (FRP), steel plate bonding, section enlargement, and external post-tensioning for repairing and strengthening reinforced concrete (RC) and masonry structures. FRCM consists of a reinforcing phase (fabrics) embedded into a matrix (cementitious …

A Novel Augmented Finite Element Method For Modeling Arbitrary Cracking In Solids, Seyedreza Mohammadizadeh

Open Access Dissertations

Advanced composite materials are known as important engineering materials in industry. Unlike structural metals which are homogeneous and isotropic, composites are inherently inhomogeneous and anisotropic which leads to further difficulty in damage tolerance design. The predictive capabilities of existing models have met with limited success because they typically cannot account for multiple damage evolution and their coupling. Consequently, current composite design is heavily dependent upon lengthy and costly test programs and empirical design methods. There is an urgent need for efficient numerical tools that are capable of analyzing the progressive failure caused by nonlinearly coupled, multiple damage evolution in composite …

Synthesis And Characterization Of High Nuclearity Bimetallic Group 8-Group 10 Transition Metal Cluster Complexes, Sumit Saha

Open Access Dissertations

In past years bimetallic nanoparticle catalysts have been shown to exhibit superior catalytic properties, due to the presence of different metals such that one metal performs a certain role in a catalytic cycle and the other performs another function. Our goal was to synthesize bimetallic cluster complexes containing cheap metals for the application in heterogeneous catalysis. We have reported the reaction of Fe5(C)(CO)15 with Ni(COD)2, in acetonitrile solvent to afford the nickel-iron complex NiFe5(C)(NCMe)(CO)15. In addition, some chemistry with this compound was studied which gave new Fe-Ni carbide clusters with varying Fe-Ni ratios. Similar chemistry was observed with the reaction …

Horizontal Vs. Vertical Connectivity In Caribbean Reef Corals: Identifying Potential Sources Of Recruitment Following Disturbance, Xaymara M. Serrano

Open Access Dissertations

The extent to which reefs are effectively connected to one another, and their potential to serve as sources of larval replenishment following disturbance, are topics of considerable interest in contemporary reef science. To date, most assessments of reef connectivity have emphasized long-distance horizontal dispersal of propagules from one shallow reef to another. The extent of short-distance vertical connectivity, however, has been largely unquantified. To fill this gap in knowledge, I developed DNA microsatellite loci for two Caribbean depth-generalist coral species with different life-history reproductive strategies (Montastraea cavernosa and Porites astreoides), and assessed connectivity in >1,200 coral samples collected from 3 …

Fine-Scale Distributions Of Plankton And Larval Fishes: Implications For Predator-Prey Interactions Near Coastal Oceanographic Features, Adam Tyler Greer

Open Access Dissertations

Describing the distributions of organisms on scales relevant to individuals (1-100 m) is critical to understanding predator-prey interactions within the plankton. This has driven the development of plankton imaging technology with synoptic physical parameters (temperature, salinity, depth), which facilitates high-resolution taxonomic and spatial descriptions. We utilized a novel In Situ Ichthyoplankton Imaging System (ISIIS) that addressed some shortcomings of other imaging systems by allowing for the simultaneous sampling of both abundant (e.g., copepods, appendicularians, marine snow) and rare (e.g., fish larvae, medusae, ctenophores) members of the plankton community. The main objectives of this study were 1) to describe the physical …

Apoptotic Regulation Of B Cell Development And Autoimmunity, Jacqueline A. Wright

Open Access Dissertations

Misguided immune reactions against self can cause autoimmunity. Although multiple factors are likely involved, a common feature is altered lymphocyte homeostasis due to dyregulated apoptosis. Here, we show that the integration of signals from the BCR and BAFF-R promotes survival of T2 cells that have passed the self-reactivity checkpoint. BCR engagement produces NF-κB2 protein, a substrate used by the BAFF-R for the activation of the alternative NF-κB pathway. In contrast, pre-checkpoint T1 cells fail to integrate BCR and BAFF-R signals and remain sensitive to BCR-mediated-apoptosis. Btk and c-Rel are critical in this signal integration and B-cell survival. Importantly, BAFF-R promotes …

Improving Virtual Machine I/O Performance In Cloud Environments Via I/O Functionality Offloading, Sahan Bamunavita Gamage

Open Access Dissertations

In recent years there has been a rapid growth in the adoption of cloud computing. A key technology that drives cloud computing is virtualization. In addition to enabling multi-tenancy in cloud environments, virtualizing hosts in the cloud environments has made management of hardware resources increasingly flexible. An important consequence of virtualizing hosts in the cloud is the negative impact it has on the I/O performance of the applications running in the virtual machines.

In this dissertation, we address the important problem of alleviating the negative impact of virtualization on I/O of the virtual machines. First, we show that virtual machine …

Semiconductor Nanomaterial Development For Photovoltaic And Thermoelectric Applications, Liangliang Chen

Open Access Dissertations

Today's world is frequently going through fossil energy shortage and environmental consequences brought by the over-emission of greenhouse gas from burning fossil fuels. Therefore, it is urgent now more than ever to discover or develop clean and sustainable power generation approaches. Among various approaches, photovoltaics and thermoelectrics have been more and more attentive both in academia and industry. Photovoltaic power generators can significantly decrease carbon dioxide emission by directly converting sunlight into electricity, and thermoelectric power generators can increase energy use efficiency by recycling waste heat into electricity. This research seeks to gain a better understanding of the mechanism that …

Disk Diffusion Breakpoint Determination Using A Bayesian Nonparametric Variation Of The Errors-In-Variables Model, Glen Richard Depalma

Open Access Dissertations

Drug dilution (MIC) and disk diffusion (DIA) are the two most common antimicrobial susceptibility tests used by hospitals and clinics to determine an unknown pathogen's susceptibility to various antibiotics. Both tests use breakpoints to classify the pathogen as either susceptible, indeterminant, or resistant to each drug under consideration. While the determination of these drug-specific MIC classification breakpoints is straightforward, determination of comparable DIA breakpoints is not. It is this issue that motivates this research.

Traditionally, the error-rate bounded (ERB) method has been used to calibrate the two tests. This procedure involves determining DIA breakpoints which minimize the observed discrepancies between …