Digital Commons Network^™

Population Biology, Ecology, And Ecosystem Contributions Of The Eastern Oyster (Crassostrea Virginica) From Natural And Artificial Habitats In Tampa Bay, Florida, Michael Drexler

USF Tampa Graduate Theses and Dissertations

The objective of this project was to document the status of oysters, Crassostrea virginica, from non-reef habitats throughout Tampa Bay, Florida, and assess the ecosystem contributions of those populations relative to reef-dwelling oysters. The aspects of oyster ecology studied here include condition, prevalence and intensity of disease (Perkinsus marinus - dermo), reproductive activity (including stage, fecundity, and juvenile recruitment), adult oyster density, and the faunal community associated with the oysters.

The predominant source of variation was seasonal, with lesser contributions among sites, and in most cases, little or no effect of the habitat type. Oysters populations from each habitat …

Regulation Of Cell Adhesion Strength By Spatial Organization Of Focal Adhesions, Kranthi Kumar Elineni

USF Tampa Graduate Theses and Dissertations

Cell adhesion to extracellular matrix (ECM) is critical to various cellular processes like cell spreading, migration, growth and apoptosis. At the tissue level, cell adhesion is important in the pathological and physiological processes that regulate the tissue morphogenesis. Cell adhesion to the ECM is primarily mediated by the integrin family of receptors. The receptors that are recruited to the surface are reinforced by structural and signaling proteins at the adhesive sites forming focal adhesions that connect the cytoskeleton to further stabilize the adhesions. The functional roles of these focal adhesions extend beyond stabilizing adhesions and transduce mechanical signals at the …

Meta-Analysis Of Single-Case Data: A Monte Carlo Investigation Of A Three Level Model, Corina M. Owens

USF Tampa Graduate Theses and Dissertations

Numerous ways to meta-analyze single-case data have been proposed in the literature, however, consensus on the most appropriate method has not been reached. One method that has been proposed involves multilevel modeling. This study used Monte Carlo methods to examine the appropriateness of Van den Noortgate and Onghena's (2008) raw data multilevel modeling approach to the meta-analysis of single-case data. Specifically, the study examined the fixed effects (i.e., the overall average baseline level and the overall average treatment effect) and the variance components (e.g., the between person within study variance in the average baseline level, the between study variance in …

Palaeoclimatic Significance Of Perennial Ice Accumulations In Caves: An Example From Scarisoara Ice Cave, Romania, Aurel Persoiu Tiritu

USF Tampa Graduate Theses and Dissertations

Stable isotopes in ice cores drilled in the polar and high-mountain region have been used intensively to reconstruct past climatic changes and atmospheric dynamics. However, no similar studies have been conducted on perennial ice accumulations in caves due to a limited understanding of the links between the external and cave environments, and the way in which the climatic signal can be recorded by the cave ice.

In this thesis, we successfully designed and build a research methodology for the reconstruction of past climatic changes based on perennial ice accumulation in caves, using as example the Scarisoara Ice Cave, Romania. The …

Relations Among Classroom Support, Academic Self-Efficacy, And Perceived Stress During Early Adolescence, Krystle Kuzia Preece

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to gain insight into the relations between support, academic self-efficacy, and stress during the transition into middle school. Research suggests that early adolescents experience an increase in stress across the middle school transition (e.g., Chung, et al., 1998), due to a mismatch between the individuals' developmental needs and the environment (Eccles et al., 1993). Stress has been found to be a risk factor for mental health disorders among adolescents (Grant et al., 2003). The current study examined if teacher and classmate support and academic self-efficacy served as external and internal resources for buffering stress …

Carbon Nanotubes Interactions: Theory And Applications, Adrian Popescu

USF Tampa Graduate Theses and Dissertations

A theoretical framework describing the carbon nanotubes interaction, involving two distinct approaches, is presented. Based on the results obtained practical applications using carbon nanotubes are further proposed.

First a classical approach is employed for different geometrical configurations, such as parallel or concentric carbon nanotubes. For all the cases analytical expressions for the systems potential energies are derived.

The results obtained using the classical approach are used to propose a few practical applications. These applications include a non-contact device for profiling surfaces and a custom telescopic double wall carbon nanotube for nanolithography applications. It is expected that such devices can be …

Biological Effective Dose (Bed) Distribution Matching For Obtaining Brachytherapy Prescription Doses & Dosimetric Optimization For Hybrid Seed Brachytherapy, Jakub Pritz

USF Tampa Graduate Theses and Dissertations

Radioactive seed implant brachytherapy is a common radiotherapy treatment method for prostate cancer. In current clinical practice, a seed consists of a single isotope, such as ¹²⁵I or ¹⁰³Pd. A seed containing a mixture of two isotopes has been proposed for prostate cancer treatment. This study investigates a method for defining a prescription dose for new seed compositions based on matching the biological equivalent dose (BED) of a reference plan.

Ten prostate cancer cases previously treated using single isotope seeds (5 using ¹²⁵I seeds and 5 using ¹⁰³Pd seeds) were selected for this study. Verification of …

Realizing Virtuality: Tracing The Contours Of Digital Culture, Nicholas Andrew Riggs

USF Tampa Graduate Theses and Dissertations

People connect digitally through social media, fusing their relationships with meaning in a non-space of relational potential--a translucent and fluctuating enclave where the self becomes elastic. This thesis explores how I have formed bonds in virtual space through ritual interaction. Looking at the ways I learned to use technology through the progression of a close personal relationship, I suggest that social media use is a performance of identity--a virtuality that exposes how people negotiate the digital enclosure of contemporary society. My story is one of digital nativity and reclaiming love through virtual performance. I show how these performances have had …

The Relationship Between Statistics Self-Efficacy, Statistics Anxiety, And Performance In An Introductory Graduate Statistics Course, William Ray Schneider

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to determine the relationship between statistics self-efficacy, statistics anxiety, and performance in introductory graduate statistics courses. The study design compared two statistics self-efficacy measures developed by Finney and Schraw (2003), a statistics anxiety measure developed by Cruise and Wilkins (1980), and a course performance measure. To view self-efficacy from two perspectives, the Current Statistics Self-Efficacy (CSSE) assessed student confidence in their ability to complete specific statistics tasks in the present, whereas Self-Efficacy to Learn Statistics (SELS) assessed student confidence in their ability to learn statistics in the future. The performance measure was the combined …

A Sedimentary Record Of Regional Land-Use And Climate Change In The Manatee River, Manatee County, Florida, Patrick Schwing

USF Tampa Graduate Theses and Dissertations

The Manatee River Watershed (Manatee County, FL) has experienced heavy anthropogenic development over the last 100 years and was relatively pristine previous to this development. The population growth within the watershed has surpassed the national trends and has doubled in the last 30 years. The heavy anthropogenic development has led to depletion in natural resources, nutrient loading, coastal erosion, and increased pollution. This study constructs records of sedimentological processes to compare the pre-development records to the past 100 years of anthropogenic development. The first portion of this study identifies specific changes in sedimentation attributed to anthropogenic activity in the Manatee …

Parent Involvement In Children's Schooling: An Investigation Of Measurement Equivalence Across Ethnic Groups, Heather Marie Scott

USF Tampa Graduate Theses and Dissertations

Epstein et al.'s Theory of Overlapping Spheres of Influence focuses on the interaction and communication, or partnerships, among families, schools, and the community to bring the three closer together. The theory works in conjunction with Epstein's typology of parental involvement, which focuses on six types of involvement that are instrumental to a child's development and his/her school and educational success. These serve as the framework for the study and support the construct of parent's involvement in children's schooling.

The purpose of the current study was to conduct further validation analyses of an inventory designed to measure the construct of parent …

El Poder / The Power: Latino/A Literature Inclusion In The Florida High School Language Arts Classroom As A Contributing Deterrent To The Latino/A Dropout Rate, Monica Adriana Sleeter

USF Tampa Graduate Theses and Dissertations

Curricula throughout the country, specifically in the School District of Hillsborough County (SDHC), do not encompass diverse subject matter as it relates to Latino/a students. The primary argument posed in this thesis is that consistent engagement to Latino/a writings in the English language arts classroom can be a positive force that contributes to an increased rate of retention of Latino/a youths in high school and a higher percentage of Latino/a high school graduates. This Latino/a literature can be in the form of supplementary reading material that teachers will have access to that will include Latino/a literature from various authors that …

Estimating Groundwater Discharge In The Oligohaline Ecotone Of The Everglades Using Temperature As A Tracer And Variable-Density Groundwater Models, Victora Spence

USF Tampa Graduate Theses and Dissertations

Recent research suggests that brackish, marine-derived groundwater up-wells in the oligohaline ecotone of the coastal Everglades, bringing with it phosphorus to an otherwise phosphorus-poor environment. The purpose of this study is to estimate the rates and timing of the groundwater discharge by using variable-density groundwater models constructed, calibrated, and validated with field measurements of hydraulic head and surface and subsurface temperature. Modeled groundwater discharge rates ranged from 5.4E-04 mm/day in August to -1.3E-03 mm/day in June for Shark Slough and 4.8E-01 mm/day in June to -1.4E-01 mm/day in January for Taylor Slough, where positive values imply groundwater discharge and negative …

The Role Of Program Climate And Socialization In The Retention Of Engineering Undergraduates, Heather Elizabeth Ureksoy

USF Tampa Graduate Theses and Dissertations

Increasing women's participation in the fields of science, technology, engineering and mathematics (STEM) can promote a healthy economy by ensuring a diverse and well-qualified STEM workforce, not only in the quantity of females in the workforce, but diversity in thinking and creativity. It will also send a positive message to young women about the breadth of educational opportunities and career choices they have available to them. However, women continue to participate in engineering education in a far lower rate than men. Attracting and retaining female students has become a challenging problem for the academic engineering community. In this study, a …

Statistical Analysis And Modeling: Cancer, Clinical Trials, Environment And Epidemiology., Dimitrios Vovoras

USF Tampa Graduate Theses and Dissertations

The current thesis is structured in four parts. Vector smoothing methods are used to study environmental data, in particular records of extreme precipitation, the models utilized belong to the vector generalized additive class. In the statistical analysis of observational studies the identification and adjustment for prognostic factors is an important component of the analysis; employing flexible statistical methods to identify and characterize the effect of potential prognostic factors in a clinical trial, namely "generalized additive models", presents an alternative to the traditional linear statistical model. The classes of models for which the methodology gives generalized additive extensions include grouped survival …

Crystal Engineering Of Multiple Component Crystal Forms Of Active Pharmaceutical Ingredients, David Rudy Weyna

USF Tampa Graduate Theses and Dissertations

Enhancing the physicochemical properties of solid-state materials through crystal engineering enables optimization of these materials without covalent modification. Cocrystals have become a reliable means to generate novel crystalline forms with multiple components and they exhibit different physicochemical properties compared to the individual components. This dissertation exemplifies methodologies to generate cocrystals of active pharmaceutical ingredients (API's) based upon knowledge of supramolecular interactions (supramolecular synthons), while focusing on enhanced delivery through in vitro and in vivo processes with both salts and cocrystals respectively.

The utility of mechanochemistry involving small amounts of an appropriate solvent, or solvent drop grinding (SDG), has been shown …

Potential Habitat Of Acropora Spp. On Florida Reefs, Katherine Wirt

USF Tampa Graduate Theses and Dissertations

Elkhorn and Staghorn corals (Acropora palmata, A. cervicornis) were listed as threatened species under the Endangered Species Act (ESA) in 2005. The threatened status of these species is unprecedented given the vital role they historically played as major constructors of western Atlantic and Caribbean coral reefs. The goal of my study was to evaluate the current extent of habitat of the two species using a database of reported in situ observations. From these observations, potential habitat maps were produced based on benthic substrata and depth parameters throughout the Florida reef tract using GIS software. Locations of 99% of …

Geometric Transformations In Middle School Mathematics Textbooks, Barbara Zorin

USF Tampa Graduate Theses and Dissertations

This study analyzed treatment of geometric transformations in presently available middle grades (6, 7, 8) student mathematics textbooks. Fourteen textbooks from four widely used textbook series were evaluated: two mainline publisher series, Pearson (Prentice Hall) and Glencoe (Math Connects); one National Science Foundation (NSF) funded curriculum project textbook series, Connected Mathematics 2; and one non-NSF funded curriculum project, the University of Chicago School Mathematics Project (UCSMP).

A framework was developed to distinguish the characteristics in the treatment of geometric transformations and to determine the potential opportunity to learn transformation concepts as measured by textbook physical characteristics, lesson narratives, and analysis …

Numerical Simulations Of Heat Transfer Processes In A Dehumidifying Wavy Fin And A Confined Liquid Jet Impingement On Various Surfaces, Mutasim Mohamed Sarour Elsheikh

USF Tampa Graduate Theses and Dissertations

This thesis consists of two different research problems. In the first one, the heat transfer characteristic of wavy fin assembly with dehumidification is carried out. In general, fin tube heat exchangers are employed in a wide variety of engineering applications, such as cooling coils for air conditioning, air pre-heaters in power plants and for heat dissipation from engine coolants in automobile radiators. In these heat exchangers, a heat transfer fluid such as water, oil, or refrigerant, flows through a parallel tube bank, while a second heat transfer fluid, such as air, is directed across the tubes. Since the principal resistance …

Two-Dimensional Computer Model Of Human Atrial Ablation, Samineh R. Esfahani

USF Tampa Graduate Theses and Dissertations

A finite-element model of a two-dimensional slice of human atrial tissue for the study of the electrograms and propagation of action potentials is presented. Action potential propagation is described by a reaction-diffusion model coupled with the complex Courtemanche et al. atrial cell model. The effects of recording electrode size and location on electrograms are presented. Action potential propagation as a result of atrial fibrillation ablation therapy is also modeled by defining a lesion area with decreased electrical conductivity. The effect of electrical conductivity and geometry of the lesion was also studied. It is shown that the success rate of atrial …

Examining Reasons For Bottled Water Consumption: A Case Study In Pensacola, Florida, Marina Leigh Foote

USF Tampa Graduate Theses and Dissertations

Over-consumption in developed economies undoubtedly puts a large strain on the environment, and many would argue that the damage is irreversible. Current uses and rates of consumption of freshwater resources are also deemed to be unsustainable. A large contributor to the high demand for water is the shift in consumer preferences from tap to bottled water. In the last few decades, bottled water companies have set unprecedented records, surpassing all other types of non-alcoholic beverages to become the second largest beverage market next to soda. Bottled water has been on the rise due to its supposed safety, purity and convenience. …

The Positive Illusory Bias: Do Adhd Symptoms Differ Among Young Adolescents With Accurate Versus Discrepant Self-Perceptions?, Sarah A. Fefer

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to gain insight into whether inattentive, hyperactive/ impulsive, and depressive symptoms differ among young adolescents with negative, accurate, or positive self-perceptions of their academic and social competence. Current literature suggests that elementary-age children with ADHD display overly positive self-perceptions, often referred to as the positive illusory bias (PIB; Owens, Goldfine, Evangelista, Hoza, & Kaiser, 2007). Self-reports of academic and social self-concept were compared to teacher ratings and test scores for 164 middle school students in an effort to determine if the PIB was present within this sample. Inattentive and hyperactive/impulsive symptoms were found to …

Cataloguing Diseases And Pests In Captive Corals, Adrienne George

USF Tampa Graduate Theses and Dissertations

Stony corals (Order Scleractinia) are susceptible to a variety of diseases, which can occur from abiotic or biotic factors, or a combination of both. Public aquaria provide opportunities to study coral disease. Because coral mucus is the first line of defense against disease, the Biolog EcoplateTM is a useful tool to detect differences in microbial assemblages in the surface mucopolysaccharide (mucus) layer when comparing healthy and diseased corals. Histological examination is essential to document structural changes in coral tissue in response to diseases. This study identifies and characterizes diseases in captive corals through visual recognition, characterization of carbon utilization by …

A Cross-Cultural Adaptation Of The Irrational Beliefs Inventory From English To Icelandic, Gudmundur Torfi Heimisson

USF Tampa Graduate Theses and Dissertations

The Irrational Beliefs Inventory (IBI) was built to measure self-defeating beliefs as conceptualized in Rational-Emotive Behavior Therapy. The IBI has five factors: worrying, rigidity, problem avoidance, need for approval, and emotional irresponsibility. A three-phase cross-cultural study was conducted to translate and adapt the IBI from English to Icelandic, and a Confirmatory Factor Analysis (CFA) approach was used for a test of factorial validity and cross-cultural invariance.

In Phase 1, the IBI was translated from English to Icelandic, using a forward-translation and back-translation. Two forward-translators and two back-translators were recruited. In Phase 2, qualitative interview methods were used in both the …

Relative Abundance And Spatial Distribution Of Lepomid Sunfishes In The Peace River, Justin Henry Heller

USF Tampa Graduate Theses and Dissertations

This study examines spatially continuous sampling data in order to investigate patterns of abundance and distribution of three recreationally important sunfish species (bluegill, redear, and spotted sunfish) along the main-stem of the Peace River, a large softwater river located in southwest Florida. A total of 467 electrofishing transects were sampled biannually from spring 2008 to spring 2010. Sampling sites ranged from the headwaters of the Peace River in Polk County, FL to the oligohaline waters located in Charlotte County, FL. All fish were collected with boat mounted electrofishing gear, and aquatic habitat and physiochemical water quality measurements were recorded at …

Modeling Endogenous Treatment Eects With Heterogeneity: A Bayesian Nonparametric Approach, Xuequn Hu

USF Tampa Graduate Theses and Dissertations

This dissertation explores the estimation of endogenous treatment effects in the presence of heterogeneous responses. A Bayesian Nonparametric approach is taken to model the heterogeneity in treatment effects. Specifically, I adopt the Dirichlet Process Mixture (DPM) model to capture the heterogeneity and show that DPM often outperforms Finite Mixture Model (FMM) in providing more flexible function forms and thus better model fit. Rather than fixing the number of components in a mixture model, DPM allows the data and prior knowledge to determine the number of components in the data, thus providing an automatic mechanism for model selection.

Two DPM models …

Associate Degrees In Health Related Occupations As Predictors Of Success In Physician Assistant Programs, David E. Kotun

USF Tampa Graduate Theses and Dissertations

The primary purpose of this study was to determine if applicants who had an associate degree in the health sciences prior to acceptance to a physician assistant program would do better than those applicants without an associate degree in the health sciences on three measures of success of physician assistant education. The three measures of success used were graduation rates, scores on the Physician Assistant Knowledge Rating and Assessment Tool (PACKRAT), and performance on the national certifying exam, the Physician Assistant National Certification Examination (PANCE). Data used for this dissertation were taken from original source documents and raw data sent …

Rethinking Buffer Operations In A Dual-Store Framework, Melissa Lehman

USF Tampa Graduate Theses and Dissertations

Atkinson and Shiffrin's (1968) dual-store model of memory includes a structural memory store along with control processes conceptualized as a rehearsal buffer. I present a variant of Atkinson and Shiffrin’s buffer model within a global memory framework that accounts for findings previously thought to be difficult for it to explain. This model assumes a limited capacity buffer where information is stored about items, along with information about associations between items and between items and the context in which they are studied. The strength of association between items and context is limited by the number of items simultaneously occupying the buffer. …

Evaluating The Effects Of Beach Nourishment On Loggerhead Sea Turtle (Caretta Caretta) Nesting In Pinellas County, Florida, Corey R. Leonard Ozan

USF Tampa Graduate Theses and Dissertations

The health of Florida's beaches are vital to the survival of loggerhead sea turtles (Caretta caretta), as nearly half of the world's loggerheads nest on the states beaches. Many of the beaches utilized by the turtles have undergone nourishment projects in hopes of combating erosion of the shoreline, protecting beachfront property, and creating more suitable beaches for tourism. Although it is argued that beach nourishment benefits sea turtles by providing more nesting habitat, the effects of the Pinellas County nourishment projects on loggerhead nesting are unknown. Beach nourishment can alter the compaction, moisture content, and temperature of the sand, all …

Device Physics Of Solution Processable Solar Cells, Jason Erik Lewis

USF Tampa Graduate Theses and Dissertations

This Ph.D work reports the studies of photovoltaic devices produced by solution processable methods. Two material systems are of interest: one is based on organic semiconductors, and another on organic/inorganic hybrid composites. Specifically, organic photovoltaic (OPV) devices are made using photoactive materials consisted of a p-conjugated polymer [Poly(3-hexylthiophene), or P3HT] and fullerene derivative [phenyl-C60-butric acid methyl ester, or PCBM] in a bulk heterojunction (BHJ) structure of donor/acceptor network. On the other hand, hybrid photovoltaic (HPV) devices are made from blend of quantum dots and p-conjugated polymers. The QD material presented here are of the lead sulfide (PbS), and lead selenide …