Digital Commons Network^™

Ultrasound As A Physical Force For Scaffold-Based Bone Repair, James D. Veronick

Doctoral Dissertations

Non-invasive, transcutaneous low intensity pulsed ultrasound (LIPUS) therapy has shown clinical efficacy in bone healing for over the past two decades; however, the exact mechanism of action remains largely unknown. The goal of this work was to find more conclusive evidence as to how LIPUS works in addition to optimizing the currently used clinical therapy. We developed and characterized our own highly tunable ultrasound system as well as a hydrogel scaffold system for tissue mimetics. A series of experiments evaluated the response of our adjustable ultrasound system to: cells alone; hydrogels alone; cell-hydrogel encapsulation; and cell-hydrogel encapsulation implantation into a …

Investigating The Role Of Surface Hydrophobicity In Protein Aggregation, Elizabeth Zecca

Doctoral Dissertations

Hydrophobic interactions between protein molecules are considered to be a significant contributor to attractive protein-protein interactions (PPIs) in solution. Attractive PPIs play critical roles in self-association and aggregation, thus affecting the overall protein stability. Surface hydrophobicity of three model proteins was characterized by hydrophobic interaction chromatography and fluorescence spectroscopy. To compensate for known limitations of these two widely used methods, a novel approach, based upon Nuclear Magnetic Resonance Spectroscopy (NMR), was investigated as a potential alternative. The degree of decrease in the transverse relaxation time (T2) of small molecule probe, such as phenol, due to its interaction with the protein …

De Novo Repeats Construction: Methods And Applications, Chong Chu

Doctoral Dissertations

Repeat elements are important components of eukaryotic genomes. The dropping cost of the second and third generation sequencing technologies provides opportunities to study repeat elements of hundreds of species and thousands of individuals of one species. Based on the quality of the assembled genomes, generally there are two obstacles for studying repeat elements: (1) For species with high repetitive or complex genomes that do not have high quality genomes assembled, how do we construct de novo repeat elements? (2) For species with high quality genomes assembled, how to detect mobile elements insertions (one type of repeat elements) of different individuals …

Development Of Transgene Containment Technologies For Woody Plants, Wei Li

Doctoral Dissertations

Transgenic technology provides a powerful tool for woody plant improvement. However, the full utilization of this technology has been stagnant due to gene flow and food safety concerns. This dissertation describes two transgene containment techniques that are particularly useful for woody plants. The first one is a flowerless plant technique that can be used to prevent pollen- and seed-mediated transgene flow. We developed an artificial promoter sequence, rPTAG2I, and demonstrated that this sequence is floral-predominant in tobacco with no detectable activity in the vegetative tissues of tobacco and poplar. Transgenic tobacco plants expressing the Diphtheria toxin A (DT-A) …

Quantum Dot Channel Field-Effect Transistors And Non-Volatile Memories: Fabrication And Simulation, Jun Kondo

Doctoral Dissertations

Quantum dot channel (QDC) and Quantum dot gate (QDG) field effect transistors (FETs) have been fabricated on crystalline Si and poly Si thin films using cladded Si and Ge quantum dots. In particular, this thesis presents modeling and fabrication of quantum dot channel field effect transistors (QDC-FETs) using cladded Ge quantum dots on poly-Si thin films grown on silicon-on-insulator (SOI) substrates. HfAlO₂ high-k dielectric layers are used for the gate dielectric. QDC-FETs exhibit multi-state I-V characteristics which enable 2-bit processing, and reduce FET count and power dissipation, and are expected to make a significant impact on the digital circuit …

Hume's "Of Scepticism With Regard To Reason", Benjamin M. Nelson

Doctoral Dissertations

The arguments in “Of scepticism with regard to reason” get their start from Hume’s claim that, thanks to our “fallible and uncertain faculties,” we must “check” any present judgment from reason in a step of corrective reasoning (T 1.4.1.1; SBN 180). A corrective step is meant to “correct and regulate” present judgments from reason through reflection on past judgments from reason (T 1.4.1.5; SBN 181-82). Hume argues that this ushers in the extinction of knowledge and belief because reflection on past judgments will inevitably diminish our assurance for any present judgment. Why Hume thinks diminishment is inevitable has remained elusive. …

Modeling Of Structural, Elastic, And Polar Properties Of Organic And Inorganic Ferroelectrics, Fu-Chang Sun

Doctoral Dissertations

Computational materials science has become an important branch of research with the advent of high performance computers and efficient algorithms. The viability of solving fundamental theories allows not only to understand experimental results, but predict properties of exotic materials or materials at extreme conditions. There exists fundamental theories that has been applied in different domains of length and time scales, where certain approximations are employed which enable improved performance with minimum compromise of accuracy.

In this Thesis, various computational approaches at different length scales are considered to investigate different classes of organic and inorganic ferroelectric materials to describe structural-property relations. …

Application Of Uv Light Scattering To Detect Reversible Self-Association And Aggregation Of Proteins In Solution, Japneet Kaur

Doctoral Dissertations

Monoclonal antibodies and their derivatives have emerged as one of the most successful class of biologics in the past few decades. Antibodies are often formulated at high concentrations in order to achieve the desired therapeutic levels on subcutaneous administration. Reversible self-association and aggregation are two of the major challenges associated with formulating high concentration antibodies. The use of static light scattering as a tool for characterizing self-association and aggregation in protein solutions is reviewed. A detailed understanding of the effect of absorption on Rayleigh light scattering intensity and turbidity was developed for wavelengths where both scattering and absorption occur simultaneously. …

Reducing Alarm Fatigue In The Intensive Care Unit: A Quality Improvement Research Study, Megan E. Speich

Doctoral Dissertations

A phenomenon called alarm fatigue has been identified as an outcome of nearly 40 different alarms that sound at any given time in the Intensive Care Unit (ICU) (Borowski et al., 2011). Alarm fatigue can result in impaired recognition of worsening patient conditions and has been implicated in fatal patient events (Kowalczyk, 2010; Altimari, 2017).

A quality improvement research study (QIRS) was conducted, aimed at reducing total alarms including noncritical (clinically irrelevant) and false alarms that contribute to the incidence of alarm fatigue and the potential for unsafe conditions. The project included exploration of the critical care nurse’s attitudes toward …

The Role Of Prostaglandin E2 Signaling In Acquired Oxaliplatin Resistance, Huakang Huang

Doctoral Dissertations

The platinum-base chemotherapeutic agent, oxaliplatin, is used to treat metastatic colorectal cancer (CRC). Unfortunately, nearly all patients develop acquired resistance to oxaliplatin after long-term use, limiting its therapeutic efficacy. Recent studies demonstrated synergistic inhibition of colorectal tumor growth by the combination of cyclooxygenase-2 (COX-2) inhibitors with oxaliplatin. The major COX-2 product, prostaglandin E2 (PGE₂), has been implicated in colorectal carcinogenesis; however, it is unknown whether PGE₂ affects colorectal tumor response to oxaliplatin. In this study, we investigated the potential role of PGE₂ in oxaliplatin resistance of human colon cancer cells. Total secreted PGE₂ levels were …

Online Research And Learning As Measured By Performance Based Simulations: The Effects Of A State One-To-One Initiative With Middle School Science Students, Clint Kennedy

Doctoral Dissertations

This study investigated how students in two states, one with and one without a state-wide one-to-one laptop program, performed on measures of online research and learning in science. The study replicated and extended the findings of a recent study using more current and more extensive data. In general, this study adds to the body of research looking specifically at the integration of Internet-based technology into teaching and student learning (Leu, Forzani, Rhoads, Maykel, Kennedy & Timbrell, 2015; Lankshear & Knobel, 2011; Greenhow, Robelia & Hughes, 2009; Jonassen, Howland, Moore & Marra, 2002). Additionally, this study examined the extent to which …

Investigating Differences In The Biomechanics Of Goal Directed Movements Of The Upper Extremity, Tanimu Deleon-Nwaha

Doctoral Dissertations

The Office of Naval Research (ONR) is interested in studying the biomechanics of upper extremity movement in a non-sea state environment. In this work, efforts to understand goal directed motor movement efficiency in the context of human performance is vital in modeling and predicting potential outcomes to shipboard naval damage control procedures, which becomes of particular importance with the introduction of women (who are of smaller anthropometries) on maritime vessels. This dissertation directly supports this Navy initiative and provides further insight into measuring goal directed end-effector (i.e., fingertip) biomechanics from an anthropometric perspective. The two objectives of this dissertation were …

Phase Change Devices For Nonvolatile Logic, Nadim H. Kanan

Doctoral Dissertations

Memory access latencies are some of the major limitations on data intensive computation performance nowadays. The possibly achievable CPU clock frequencies must be limited to the maximum access speed of the off-chip memory which constrains the overall system speed, regardless of the power consumption constraints. This computational bottleneck is commonly referred to as the Von-Neumann bottleneck. Memory access latencies can be drastically decreased by integrating the main memory onto the CPU. Phase change memory (PCM) provides the possibility of integration of high-density high-speed non-volatile memory banks on top of the CMOS layer. This computer-on-chip concept has the potential to achieve …

Alginate Hydrogels For Bone Tissue Regeneration, Stephanie T. Bendtsen

Doctoral Dissertations

Bone tissue engineering is employed to help enhance regeneration of bone tissue that may have difficulty of achieving sufficient healing on its own. As bones tend to break in irregular manners, methods to produce engineered scaffolds more closely fitting the geometry of the defective tissue are desirable. Current techniques to produce engineered bone tissue constructs result in stiff, rigid scaffolds with limited plasticity and ability to form irregular architectures. Additionally, processing methods limit the feasibility to uniformly incorporate live cells into the scaffolds for enhanced uniform healing. The use of hydrogel materials for bone tissue engineering has gained interest due …

Akap7Γ Regulation Of Pka Substrate Phosphorylation, Marc J. Rigatti

Doctoral Dissertations

In the cell, cAMP-protein kinase A (PKA) signaling is compartmentalized. Two different receptor types, both utilizing cAMP and PKA as second messenger and signal effector, are able to convey separate signals that result in phosphorylation of distinct substrates. Signal compartmentation is possible primarily because of A Kinase Anchoring Proteins (AKAPs) that bind both PKA and a target substrate, effectively co-localizing them. AKAPs are also capable of binding to other necessary signaling components like adenylate cyclase and phosphodiesterase, thus enabling AKAPs to coordinate a signaling microdomain containing many of necessary components. In this thesis I present multiple lines of evidence demonstrating …

Reliability-Based Design Optimization With Mixture Of Random And Interval Uncertainties, David Yoo

Doctoral Dissertations

This study presents novel reliability-based design optimization (RBDO) methods with mixture of random and interval uncertainties. While conventional second-order reliability method (SORM) contains three types of errors, novel SORM proposed in this study avoids the other two types of error by describing the quadratic failure surface with the linear combination of noncentral chi-square variables and using the linear combination of probability of failure estimation. Sensitivity analysis on the developed SORM is then performed for more accurate RBDO. As an alternative to analytic RBDO, sampling-based RBDO is used in case when gradients of performance functions are not available. In this study, …

Lithography, Spectroscopy, And Super Resolution Terahertz Imaging For Quality Assurance And Authentication, Kiarash Ahi

Doctoral Dissertations

The supply chain today spreads all around the globe. For assembling a system, several components, each of which may be produced in a different country and by a different manufacturer, need to travel the globe to get to the assembly sites. In such a global supply chain, tracing the components could be a great challenge and counterfeiters can find open doors to infiltrate the markets. Several billions of dollars of counterfeit integrated circuits (IC)s are sold each year. Low-quality authentic ICs might also pass the quality control sections and enter the supply chain occasionally. The endurance and reliability of the …

Heart And Soul: A Phenomenology Of Dementia Spouse Caregivers’ Relationship Closeness, Elena Schjavland

Doctoral Dissertations

All persons with dementia exhibit combinations of cognitive impairment (memory loss and aphasia), functional losses (changes in activities of daily living), and neuropsychiatric disease manifestations (fluctuating moods, behaviors and psychoses). The spouse caregiver role and life are affected by these symptoms which can cause intimacy, reciprocity, and communication issues, and frequently result in the caregiver’s feelings of inadequacy, hopelessness, and embarrassment. Yet caregivers somehow manage to reconstruct and maintain a closeness as a couple.

Relationship closeness (RC) found in all marriages is simply depicted as the quality of the communal and emotional bond between husband and wife. Limited research demonstrates …

An Impact Analysis Of Small-Scale Fisheries Community-Based Fisheries Management (Cbfm) In Asia: A Meta-Analysis, Di Yang

Doctoral Dissertations

The contribution of small-scale fisheries is significant regarding food security and employment, especially in the developing countries. However, with the persistent overfishing and unstainable exploitation, the performance of small-scale fisheries was severely devastated, not only due to its weak governance but of poor management, perverse subsidies, destructive fishing practices, and unrestricted access.

Community-based fisheries management (CBFM) is a process by which the people themselves are given the opportunity as well as the responsibility to manage their resources, define their needs, goals, and to make decisions that have an impact upon their well-beings. Due to its social and economic benefits of …

Transient Performance Evaluation, Bottleneck Analysis And Control Of Production Systems, Zhiyang Jia

Doctoral Dissertations

The focus of production system is to analyze, improve, and control the flow of products in the manufacturing process. In the field of study, the major difficulties are unreliable machines and finite buffers capacities, which lead to nonlinear and stochastic mathematical models. Extensive results on production systems have been derived for steady state operations, while their transient performance and properties are also of practical importance but paid with significantly less attention.

In this dissertation, we study the problems of transient performance evaluation, bottleneck analysis, and production control of serial lines, closed lines and assembly systems. Specifically, in the framework of …

The Local Socioeconomic Impact Of Destination Redevelopments In Detroit And Las Vegas (1990-2010): A Novel Geographically-Weighted Shift-Share Analysis Approach, Joseph Danko

Doctoral Dissertations

The construction of new or renovation of old theaters; sport stadiums; museums; casinos; parks; and other destination sites (i.e., henceforth referred to as “destination redevelopments”) are among the most popular, alluring and expensive types of urban revitalization projects around the world. In addition to aiming to attract new visitors, local officials and other community stakeholders often invest in these projects in an attempt to both retain existing residents and recruit new residents into the neighborhoods in which these redevelopments are located. Previous research has documented some of the socioeconomic effect of specific subcategories of destination redevelopments, most particularly with respect …

Real-Time In Situ Monitoring Of Water Systems Using Electrochemical Sensors, Zhiheng Xu

Doctoral Dissertations

Archival abstract submitted

The Statistical Dynamics Of Nonequilibrium Control, Grant Murray Rotskoff '09

Doctoral Dissertations

Living systems, even at the scale of single molecules, are constantly adapting to changing environmental conditions. The physical response of a nanoscale system to external gradients or changing thermodynamic conditions can be chaotic, nonlinear, and hence difficult to control or predict. Nevertheless, biology has evolved systems that reliably carry out the cell’s vital functions efficiently enough to ensure survival. Moreover, the development of new experimental techniques to monitor and manipulate single biological molecules has provided a natural testbed for theoretical investigations of nonequilibrium dynamics. This work focuses on developing paradigms for both understanding the principles of nonequilibrium dynamics and also …

Improvement Of Fluorescence-Based Microfluidic Dna Analyzers, Collin Tranter

Doctoral Dissertations

A tremendous effort continues in the development of micro-total-analysis-systems; in support of this, many chemical passivation methods have been developed to enhance the biocompatibility of such microfluidic systems. However, the suitability of these passivation techniques to many fluorescence-based assays still remains inconsistent. This part of this work is focused on the performance of a third generation intercalating DNA dye when used within microfluidic devices treated with a select variety of passivating coatings. The results of these tests indicate that passivation coatings which are intended to shed DNA based on electrostatic repulsion will in fact imbibe the fluorescent DNA intercalating dye …

The Effect Of Gamification On Audiology Awareness Among Young Adults, Shenque Lester

Doctoral Dissertations

The profession of audiology is projecting a critical shortage of practicing professionals in the near future. Although there are many potential factors that are contributing to this problem, it is generally agreed that audiology as a profession is not readily identified as a career choice by undergraduate students, nor a recognizable healthcare field/service among the general public. Due to the increased instances of hearing loss in the general population as well as the aging of the population and need for audiological services, it is imperative to find an efficient means to improve the awareness of audiology as a potential career …

Numerical And Experimental Studies On Coastal Marsh Erosion Under Hurricane Induced Wave And Current, Minhaz M. Shahriar

Doctoral Dissertations

Considering the past history and future risks of hurricanes in the USA, well understood storm protection plans are needed to shelter the important areas of the population and economy, especially within southeastern Louisiana. It is extensively assumed that marshes offer protection from hurricane though the degree of this protection is not well measured or understood due to the complex physics involved in this overall system. Moreover, marshes experience significant erosion while serving as a barrier for important areas. Consequently, a particular method to quantify the effects on marshes during a coastal hurricane period is necessary to mitigate major marsh loss. …

Acoustical Properties Of Amplified And Unamplified Stethoscopes When Examining Typical Body Sounds, Jeni Abrams Dunnington

Doctoral Dissertations

A stethoscope is intended for three main diagnostic purposes: listening to heart sounds, listening to lung sounds, and determining the presence or absence of bowel sounds (Callahan, Waugh, Matthew, & Granger, 2007). Currently, on the market there are two types of stethoscopes for practitioners to choose: unamplified and amplified stethoscopes. Furthermore, there is little research on the sound pressure levels (SPLs) produced by stethoscopes on the market. Therefore, the current study seeks to measure the SPL produced by various popular unamplified stethoscopes and compare those findings to the SPLs produced by amplified stethoscopes. Secondly, the SPL of selected amplified stethoscopes …

Optimizing Design Parameters For Thin Film Composite Hollow Fiber Membranes And Modules For Osmotic Processes, Jian Ren

Doctoral Dissertations

Osmotic processes have been considered sustainable solutions for extracting clean water and concentrating impaired water by forward osmosis (FO) and harvesting the osmotic pressure gradient for power generation via pressure retarded osmosis (PRO). Thin film composite (TFC) membranes are considered a preferred platform for osmotic processes wherein the selective and support layers can be tailored independently for preferred chemistry and structure. Hollow fiber TFC membranes in particular have garnered interests because of their high packing density. In this dissertation study, high performance TFC membranes were designed for applications in osmotic processes. Departing from previous hollow fiber membrane developments that focused …

Photochemistry Of Effluent And Natural Organic Matter And Photochemical Degradation Of Micropollutants, Laleen Chanaka Bodhipaksha

Doctoral Dissertations

The photoreactivity of treated wastewater effluent organic matter (EfOM) has received recent attention because it is an important fraction of the dissolved organic matter (DOM) pool in wastewater-receiving rivers. Dissolved organic matter contains chromophore moieties that absorb energy from sunlight and, in turn, produce reactive intermediates through secondary reactions of these excited-state moieties. Photochemically produced reactive intermediates (PPRIs) include excited state triplet organic matter (³DOM*), singlet oxygen (¹O₂), hydroxyl radicals (OH•) and others. Apparent quantum yields of production of PPRIs appear to be higher for EfOM than for natural organic materials (NOM), which implied …

Comparing The Effects Of Two Rates Of Specific Praise On Student Behavior, Kathleen Marie Williamson

Doctoral Dissertations

The relationship between classroom behavior and academic achievement is well established in the literature. Specific praise is an evidence-based classroom management strategy that has been shown to increase appropriate behavior and decrease inappropriate behavior. It is recommended that teachers use specific praise in the classroom; however, researchers have not identified the optimal rate at which this praise should be delivered. The purpose of this study was to compare the effects of two systematically manipulated rates of specific praise on the disruptive behavior and on-task behavior of elementary school students. An alternating treatments design, embedded within a multiple-baseline across participants, was …