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Effect Of Matrix Modulus On Cancer Stem Cells And Tumorsphere Formation In Three-Dimensional-Engineered Matrix, Samaneh Kamali Sarvestani

Theses and Dissertations

Maintenance of cancer stem cells (CSCs) is regulated by their microenvironment. As cancer cells are affected by many factors in their microenvironment, a major challenge is to isolate the effect of a specific factor on cancer stem cells (CSCs) while keeping other factors unchanged. We have developed a synthetic inert 3D polyethylene glycol diacrylate (PEGDA) gel culture system as a unique tool to study the effect of microenvironmental factors on CSCs response. Synthetic hydrogels provide the flexibility to design three-dimensional (3D) matrices to isolate and study individual factors in the tumor microenvironment.

The objective of this work was to investigate …

Childish Figuring: The Child As Symbol And Actor In Lillian Smith's Killers Of The Dream And James Agee's Let Us Now Praise Famous Men, Katherine Eveline Upton

Theses and Dissertations

In this thesis, I examine the presentation of the child in James Agee's Let Us Now Praise Famous Men and Lillian Smith's Killers of the Dream as part of a rhetoric of growth. Both Agee and Smith present southerners as psychologically immature due to their traumatic childhood experiences of sexism, racism and poverty. Childhood is a recurring theme in both texts. Agee and Smith present childhood as a biological, developmental stage and a metaphor for growth in their texts. The child is a real, contextually-specific figure, drawn from Agee's and Smith's observations of children in Depression-era society. Images of children's …

The Scope Of The Bis-Urea Macrocycle Assembly Motif, Michael F. Geer

Theses and Dissertations

From the formation of rock candy crystals, to the functionality of DNA in the cell, to the cosmic dust throughout the universe, supramolecular chemistry has a great impact and importance in the world around us. In this thesis, we explore the supramolecular interactions and self-assembly of bis¬-urea macrocyclic systems and investigate how their structure and assembly influences bulk properties and functionality. Specifically, in chapter one, we review the factors that guide, limit, and define supramolecular structures from the atomic to the centimeter scale.

In chapter two, we investigate the incorporation of benzophenone, a well known triplet sensitizer, within a bis-urea …

Single Crystal To Single Crystal Polymerization Of A Columnar Assembled Diacetylene Macrocycle, Weiwei Xu

Theses and Dissertations

Organic tubular materials have attracted lots of attentions for their potential applications as nanoscale fluidic transport systems, specific ion sensors, molecular sieves and confined molecular reaction containers. While conjugated polymers, due to delocalized Pi electrons, exhibit interesting solar cells and sensors applications. In this thesis, we developed a conjugated polymer which combines the attributes of conjugated polymers with tubular materials, which should have great potential to work as a sensing material.

We reproduced and scaled-up the synthesis of a polymerizable macrocycle 1 that contains two rigidly separated diacetylene units. We found that, through hydrogen bonding, 1 can assemble into columnar …

Investigations Of The Non-Covalent Ch-Π Interactions Using Molecular Torsional Balances, Chen Zhao

Theses and Dissertations

Several bicycle N-arylimide based molecular balances were designed to study aliphatic CH-pi interactions and aromatic CH-pi interactions (edge-to-face arene-arene interactions). In each case, the geometries of the interactions were characterized in the solid-state via X-ray analysis, and the strengths of interactions were characterized in solution by their folded/unfolded ratios, as measured by integration of their 1H NMR spectra.

The balances are very sensitive to variations in the strengths of weak non-covalent interactions. Several different aspects of the CH-pi interactions were studied, such as sterics, conformational entropy, cooperativity, deuterium isotope effect, substitution effects, and solvent effects. It showed that due to …

Iii-V Nitride Micro- And Nano-Scale Cantilevers For Multimodal Sensing Applications, Ehtesham Bin Quddus

Theses and Dissertations

Recent research trends in chemical and biological sensing have been geared toward developing molecular sensor devices that are fast, label free, miniaturized and portable. The performance of these devices can be dramatically improved by utilizing multimodal detection techniques, new materials and micro-/nanofabrication technologies. This is especially true for micro-/nanoscale cantilever sensors, which undergo changes in mechanical or electrical properties upon the specific binding of molecules. To develop the sensor devices with the above attributes, we utilized III-V nitride materials: InN nanowires for realizing nanoscale cantilevers and AlGaN/GaN heterostuctures with or without embedded HFETs, for developing microcantilevers. There are mainly two …

Wireless Pressure Sensor System For Medical Applications, Xuehe Wang

Theses and Dissertations

Telemedicine in the modern era is a rapidly developing industry. In a telemedicine system, sensor is the key elements and play important role in any telemedicine applications, especially implantable sensors. Unlike traditional in vitro sensors, there are some special requirements for them like battery-less, compact, and bio-friendly. Therefore, many researchers in institutes as well as in industry are continually developing implantable sensor and sensor system to fulfill the requirements of medical applications.Nine in one thousand people in the United States are born with congenital heart defects and sixty percent die before one year old. As a result, it will be …

High Quality Silicon Carbide Epitaxial Growth By Novel Fluorosilane Gas Chemistry For Next Generation High Power Electronics, Tawhid Rana

Theses and Dissertations

High quality, thick (~100µm), low doped and low defect density SiC epitaxial films are essential for high voltage (blocking voltage >10kV), light, compact and reliable next generation power devices. One of the significant challenges in obtaining high quality thick SiC epitaxial films is to restrict/eliminate the Si gas-phase nucleation or aerosol formation during growth. The generated aerosol particles adversely influence growth by reducing the growth rate due to precursor losses, and also affect crystal quality, since the Si droplets are carried to the crystal growth surface. Moreover, liquid aerosol particles adhere to the various reactor parts (parasitic deposition), and contribute …

An Assessment Of Injury Presentation To Determine Elder Abuse Prevalence In South Carolina, Brittani L. Harmon

Theses and Dissertations

As the number of individuals age 60 years of age and older continues to rise in the United States, the care and safety of this population will be a growing issue. There are many contributing factors and reasons why elder abuse occurs. Elder abuse is an emerging issue; however there is limited research and understanding in the area. There are barriers to the detection and prevention of the issue. Emergency department staff is essential to the identification and detection of possible abuse, and it is important that these providers understand the risk factors and physical manifestations of abuse and neglect …

Development Of High-Throughput Catalyst Screening For Ammonia Based Selective Catalytic Reduction Of Nitric Oxide With Parallel Analysis Using Fourier Transform Infrared Imaging, Shahriar Salim

Theses and Dissertations

Lean-burn engines, which operate under excess air to fuel ratio offer significant fuel efficiency as well as contribute to the reductions of greenhouse gas emissions. However, lean burn engines produce three main pollutants carbon monoxide (CO), nitrogen oxides (NOx) and unburned or partially burned hydrocarbons (HC), which have detrimental effect on both environment and human life. The conventional three way catalyst (TWC) which was designed to reduce NOx under stoichiometric conditions is not effective under lean-burn engine exhaust condition. Recent studies have shown that copper (Cu) exchanged chabazite (CHA) type zeolites are very promising catalysts for urea or ammonia (NH3) …

An Analysis Of The Current Use And Future Intentions To Use Mobile Learning Strategies Among Full-Time Community College Faculty, Stephanie Denise Frazier

Theses and Dissertations

This quantitative study examined how full-time community college faculty members in southern states use mobile learning (m-Learning) strategies as tools for student engagement. Specifically, research questions were designed to measure the current use of six key m-Learning strategies: augmented reality, file/resource sharing, gaming/simulation, reference/research applications, social media, and text messaging. This study also probed into faculty attitudes and beliefs in four areas: performance expectancy, effort expectancy, social influence, and facilitating conditions. Statistical analyses were conducted to determine existing relationships between these four determinants and the intentions of faculty members to use m-Learning strategies in the forthcoming academic year. Additionally, research …

Cortisol And Working Memory In Boys With Fragile X Syndrome, Jessica F. Scherr

Theses and Dissertations

Fragile X Syndrome (FXS) is a neurodevelopmental disorder and the most common cause of inherited intellectual disability. Although FXS is associated with global cognitive impairments, specific deficits in working memory have been reported in young males with FXS. Working memory is an important cognitive process that involves the ability to temporarily store and manipulate information over a short period of time. Deficits in working memory can negatively impact an individual's academic, behavioral, and social functioning. Chronic stress can adversely influence working memory performance and can be measured physiologically through salivary cortisol. It is important to study the complex relationship of …

The Artist's Gauntlet: A Singers' Physiological Responses To The Stimuli Of Rehearsing And Performing, John H. Pritchard

Theses and Dissertations

This study examined the relationship of a subject's heart rate variability, respiration rate and other vital statistics to rehearsing and performing as a singer. Among the events used for data collection were individual lessons of undergraduates and a lecture-recital presented by a graduate student. Findings indicate a general upward trend in HRV and an increase in range of HR%MAX among subjects while singing, along with a general decrease of respiration rate.

Quantifying The Effects Of Antibiotics Upon Benthic Diatoms And Marine Benthic Algal Communities, Isaac M. Hagenbuch

Theses and Dissertations

Antibiotics are a cornerstone of modern medicine. Their ability to impair prokaryotic metabolism has saved the lives of many millions of humans in the decades since wide antibiotic usage began. Antibiotic compounds are also widely used in the husbandry of animals that are used for food but, unfortunately, much of the antibiotic mass that goes into humans and animals is excreted unchanged. Those excretions go, directly or indirectly, into aquatic ecosystems. The discovery of this fact has led to a growing global concern about the fate of antibiotics in the environment. This concern is driven by no fewer than three …

Nanoparticle Self-Assembly And Ultrafast Nanomagnet Switching Dynamics, Longfei Ye

Theses and Dissertations

A novel manufacturing technology that offers a low-cost alternative for creating more complex optical materials that are assembled with single-nanometer precision is demonstrated. Using the enormous magnetic field gradients present near the surface of magnetic recording media, colloidally suspended superparamagnetic nanopartilces are self-assembled into patterned microstructures.

The position and shape of these microstructures are precisely controlled by magnetic patterns on the template. The template that can be reprogrammed and reused is magnetically recorded using commercial magnetic recording technology. These microstructures consisting entirely of self-assembled magnetic nanoparticles are then transferred to flexible polymer thin films with patterns maintained. In particular, all-nanoparticle …

The Effect Of Radiation On Myofiber Properties In Mouse Skeletal Muscle, Dennis K. Fix

Theses and Dissertations

Radiotherapy has been proven as an effective and necessary treatment for cancer. The dose given is dependent on cancer type and location. It has been previously established that skeletal muscle is the most radiation tolerant tissue in the body. With that being said there is a current gap in the literature that is missing the effect of radiation doses on the histological properties of skeletal muscle. The overall purpose of this study is to determine the effect that a single unfractionated dose of 16Gy radiation has on histological properties of myofibers when compared to 4 fractionated doses of 4Gy . …

Adverse Outcome Pathways: A Framework For Identifying Chemical Mode Of Action During Zebrafish Embryogenesis, Krystle Yozzo

Theses and Dissertations

Human health and ecological risk assessors are currently facing increased demands and public pressure to evaluate the potential risk of hundreds to thousands of chemicals based on limited toxicity data. Therefore, scientifically sound models are needed to predict toxicity without sole reliance on conventional whole-organism (vertebrate) bioassays. To help address this challenge, adverse outcome pathways (AOPs) have recently been proposed as conceptual tools to help link direct, molecular-level initiating events to adverse outcomes at higher levels of biological organization. Additionally, using AOPs as frameworks, high-throughput screening (HTS) and high-content screening (HCS) assays have been recently proposed as key components of …

Structural Origin Of Mechanical Prowess In Conch Shells, Haoze Li

Theses and Dissertations

Conch shells are natural nanocomposites with an exquisite multiscale hierarchical architecture which exhibit coupled ultrahigh mechanical strength and toughness. What materials design strategy renders conch shells such mechanical prowess? In this study, micro/nanoscale structural and mechanical characterization of conch shells (Busycon carica) has been carried out. We demonstrate, for the first time, direct evidence that the previously claimed single-crystal third-order lamellae - the basic building blocks in conch shells are essentially assembled with aragonite nanoparticles of the size ranging from 20 to 45 nm. The third-order lamellae exhibit not only elasticity but also plasticity with the strain up to 0.7% …

Synthesis And Characterization Of One Dimensional Boron-Based Nanomaterials, Rui Li

Theses and Dissertations

One dimensional (1D) metal borate and boride nanomaterials have attracted tremendous attention due to their good chemical inertness, high-temperature stability, excellent mechanical properties, and low thermal expansion coefficient.

Beta-BaB2O4 (BBO) is a well-known nonlinear optical material with a high second-order nonlinear susceptibility, wide transparency range, and high damage threshold. Using a low temperature, organic-free hydrothermal technique, single-crystalline barium polyborate Ba3B6O9(OH)6 (BBOH) nanorods were synthesized. It was found that BBO nanospindles can be achieved by annealing the BBOH nanorods at a relatively low temperature of 810 oC. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques were …

Parsing The Effects Of Physical Microenvironmental Cues On Stem Cell Adhesion And Lineage Specification, Greg M. Harris

Theses and Dissertations

Tissue engineering is a broad field geared toward improving or replacing biological material and comprises an immense collection of biological nuances to consider before strategies for clinical applications can be fully realized. Physical and biochemical signals are responsible for making up a cell's microenvironment to guide morphology and function through cell-extracellular matrix signaling, cell-cell signaling, and soluble signaling. In particular, a deeper understanding of these cell-extra cellular matrix factors guiding stem cell adhesion, spreading, and differentiation is crucial to harnessing the potential to develop tissue for regenerative purposes. Mounting evidence suggests that physical cues are a key to understanding the …

Postnatal Depression In Mexico: Healthcare Provider Conceptualizations And Policies In The Public Health Sector, Jean Marie Sims Place

Theses and Dissertations

Background: The World Health Organization (WHO) and the United Nations Population Fund (UNFPA) highlight education and training for healthcare providers and the development of a policy framework as core strategies to address maternal mental health in low- and middle-income countries. This research critically examines these strategies with respect to postnatal depression in Mexico. The research 1) addresses how healthcare providers in Mexico conceptualize postnatal depression, and 2) assesses the policies that exist in Mexico regarding postnatal depression, which will inform the next steps for policy development. The research informs appropriate healthcare provider education and training, as well as the next …

Quasinovo: Algorithms For De Novo Peptide Sequencing, James Paul Cleveland

Theses and Dissertations

High-throughput proteomics analysis involves the rapid identification and characterization of large sets of proteins in complex biological samples. Tandem mass spectrometry (MS/MS) has become the leading approach for the experimental identification of proteins. Accurate analysis of the data produced is a computationally challenging process that relies on a complex understanding of molecular dynamics, signal processing, and pattern classification. In this work we address these modeling and classification problems, and introduce an additional data-driven evolutionary information source into the analysis pipeline.

The particular problem being solved is peptide sequencing via MS/MS. The objective in solving this problem is to decipher the …

The Body As Wartime Terrain: Social Control And Female Sexuality Under Military Occupation, Frances Choe

Theses and Dissertations

This project is a comparative-historical sociological analysis of the informal and formal responses to sexual contact in two WWII period cases: between French women and Nazi troops, and German women and African-American GIs. I focus on the connection between the regulation of women's bodies and cultural expectations of gender, ideas about sexuality, and racial ideology. The results of war and subsequent occupation of the defeated nation - population decline and the acute loss of male life, strained material resources and the daily concern of survival, the social psychological sense of defeat, and intimate relationships between occupiers and the occupied - …

Osteon-Mimetic Nanocomposite Materials For Bone Regeneration, Ozan Karaman

Theses and Dissertations

The limitations of large bone defect regeneration has brought the focus of Bone Tissue Engineering research on fabricating three-dimensional bone-mimetic grafts that could enhance osteogenesis and vascularization. Osteons composed of apatite-deposited aligned collagen nanofiber layers are the fundamental building blocks of cortical bone. In natural cortical bone, mineralization is mediated by extracellular matrix (ECM) proteins with amino acid sequences rich in glutamic acid. This dissertation is focused on the establishment of a novel biomimetic approach to engineer scaffolds for healing large bone defects.

In the first part, we investigated the effect of calcium phosphate (CaP) deposition on aligned surface-modified nanofibers …

Characterizing Hypoxia And Its Behavioral Effects In 3-Dimensional Cell Aggregates, Matthew Lorincz Skiles

Theses and Dissertations

Cell transplantation can be considered a regenerative therapy, an intervention which attempts to replace or restore the function of compromised tissue by harnessing innate properties of cells that cannot be replicated artificially. For such therapies to succeed, it will be necessary to understand and closely match the physiological conditions that govern cell behaviors in vivo. One important factor is low oxygen tension, termed hypoxia, which is often overlooked in vitro. Because oxygen insufficiency can lead to cell death, hypoxia has traditionally been viewed as a negative condition. However, hypoxia can also serve as a potent regulator of crucial cell behaviors …

Maximizing Citizenship With Minimal Representation: An Analysis Of Afro-Argentine Civil Society Organizing Strategies, Prisca Suarez

USF Tampa Graduate Theses and Dissertations

This thesis examines the organizing strategies and successes of Afro-Argentine civil society organizations (CSO) in Buenos Aires. I argue that despite low representation, Afro-Argentines have strategically designed their initiatives in ways that draw on national discourses of identity rights and nationalism; and, as well, have used cultural inclusion to influence state actors, creating agency and increasing visibility. Afro-Argentines are a highly understudied population due to the common belief that they do not exist in Argentina as a group. This thesis not only dispels that myth with a history of the long hidden importance of Afro-Argentines contributions to the formation of …

Classification Models In Clinical Decision Making, Eleazar Gil-Herrera

USF Tampa Graduate Theses and Dissertations

In this dissertation, we present a collection of manuscripts describing the development of prognostic models designed to assist clinical decision making. This work is motivated by limitations of commonly used techniques to produce accessible prognostic models with easily interpretable and clinically credible results. Such limitations hinder prognostic model widespread utilization in medical practice.

Our methodology is based on Rough Set Theory (RST) as a mathematical tool for clinical data anal- ysis. We focus on developing rule-based prognostic models for end-of life care decision making in an effort to improve the hospice referral process. The development of the prognostic models is …

Building Public Health Preparedness And Food And Agriculture Defense Capabilities Using Whole Community And One Health Concepts, Joseph S. Lombardo, Jeffrey R. Ryan

Research, Publications & Creative Work

Emergency managers are embracing the Whole Community approach described in Federal Emergency Management Agency (FEMA) preparedness policy, doctrine, and guidance. The Whole Community approach entails broad collaboration and integration of effort among multiple disciplines and preparedness partners to coordinate solutions for all threats and hazards. Potential public health emergencies – to include foodborne and animal disease outbreaks – are issues on the emergency management agenda requiring such broad coordination. Scientists and public health practitioners across multiple disciplines describe a philosophy very similar to “Whole Community” known as “One Health,” linking efforts to address the shared threats to human, animal and …

Cognitive Processes Developed By Students When Solving Mathematical Problems Within Technological Environments, Fernando Barrera-Mora, Aarón Reyes-Rodríguez

The Mathematics Enthusiast

In this paper we document and discuss how the use of digital technologies in problem solving activities can help students to develop mathematical competences; particularly, we analyze the characteristics of reasoning that students develop as a result of using Cabri Geometry software in problem solving. We argue that the dynamical nature of representations constructed with Cabri, and the availability of measure tools integrated to it are important elements that enhance students’ ability to think mathematically and foster the implementation of several heuristic strategies in problem solving processes.

Developing Problem Solving Experiences In Practical Action Projects, François Pluvinage

The Mathematics Enthusiast

Problem solving doubtless is an essential element of mathematical learning, so that mathematics educators often are satisfied when finding situations that lead their students to such activity. But in many cases, the chosen situations and the ways to guide students' works are not sufficiently analyzed from a didactic point of view. Our goal in the present analysis is to underline the possible ways for managing the situations, and to exhibit the parameters that educators have at their disposition within their role as mediator between students and mathematical knowledge and know-how.