Digital Commons Network^™

Evaluation Of Terahertz Imaging For Breast Cancer Detection Using Image Morphing, Tanny Andrea Chavez Esparza

Graduate Theses and Dissertations

This thesis proposes the use of a mesh morphing algorithm for the quantitative evaluation of terahertz (THz) images. This work differs from traditional evaluation methods based on qualitative evaluation because it provides a fair and quantitative measurement of the THz imaging system's performance. The objective of the algorithm is to match the alignment, shape, and resolution of the THz and reference pathology images. Therefore, the proposed morphing method provides a pathology reference for a pixel-by-pixel evaluation of the region classification in the THz image. To achieve this, the morphing algorithm aligns the images using the Pearson's correlation coefficient and reshapes …

Applications Of Reservoir Limnology Theory And Steady-State Modeling To Eutrophication Management In Beaver Lake, Arkansas, Matthew Rich

Graduate Theses and Dissertations

Reservoir limnology theory predicts that phytoplankton biomass (PB) is greatest in riverine-transition zones and least in lacustrine zones leading to an inverse pattern in water clarity. These theoretical patterns were utilized to create a statistical model of chlorophyll-a (Chl-a), an indicator of PB, and Secchi transparency (ST), an indicator of Chl-a, in Beaver Lake, Arkansas, a 12,800-ha reservoir, in order to hindcast historical conditions. Sampling for Chl-a, ST, and photic depth occurred semimonthly at 12 locations along a 78-km transect from the river inflow to the dam during the 2015 growing season. The ratio of Chl-a and ST measured at …

Who Teaches Where? A Descriptive Analysis Of Similarities And Differences Between Teachers In Traditional And Charter Schools In Pulaski County, Arkansas, Alexandra Merlyn Boyd

Graduate Theses and Dissertations

Using survey data collected from 893 public school teachers in Pulaski County, Arkansas, this study looks for differences in traditional public school teachers and charter school teachers on their (1) backgrounds and teacher characteristics; (2) motivations for entering the teaching profession; and (3) attitudes towards school and teaching. A multivariate analysis of the data revealed that few differences exist between the two groups of teachers on their backgrounds, teacher characteristics, and motivations to enter the teaching field. However, charter school teachers were found to be more likely to have positive attitudes towards school policy changes, a stronger professional commitment to …

Survey Of Hydration Knowledge And Behavior In Youth Mountain Bike Teams, Natasha Brand

Graduate Theses and Dissertations

Many youth sports organizations recognize the importance of educating on hydration practices and awareness, although according to recent research current hydration education is not correlating to effective practices. PURPOSE: The purpose of this study was to assess and describe the hydration knowledge and behavior of student-athletes participating in competitive junior high and high school mountain bike teams, in order to substantiate further research. METHODS: A total of 133 male and female participants, ranging from 11-18 years were surveyed on their hydration knowledge and behavior. All participants were apparently healthy and were active members of a National Interscholastic Cycling Association (NICA) …

The Comparison Of Using The Preferred Or Non-Preferred Wrist When Measuring Physical Activity In College Students, Bryce Daniels

Graduate Theses and Dissertations

Introduction. People who participate in regular physical activity have a decreased risk of chronic diseases and premature death. A dramatic decrease of physical activity occurs from adolescence to young adulthood. With important implications to health, physical activity is an important behavior to measure. However, inconsistencies exist on how to measure physical activity. When using accelerometers, differences between the preferred or non-preferred wrist may result in different estimates of physical activity. Purpose. The purpose of this study was to compare the preferred and non-preferred wrist accelerometry measured physical activity using commonly used research accelerometers during structured daily college activities (Actigraph GT3x-bt …

Disordered Eating Risk And Body Image Dissatisfaction Of Division I Male And Female Cheerleaders, Christopher Blaszka

Graduate Theses and Dissertations

The sport of cheerleading is growing both in the high school and college setting, however there is little research on cheerleaders specifically, both sideline and competitive. It is clear that while this sport does not benefit from being affiliated with the NCAA, the athletes are still at large risk for disordered eating and eating disorders, and are in need of more accurate screening and prevention methods. With the lack of cheerleading studies in general, there is an even larger scarcity of studies that focus on males in cheerleading. The current study aims to fill the gap in the research regarding …

Moulins: Down The Arctic Drain, Jonathon Nugent Carlson

Graduate Theses and Dissertations

This observation-style nonfiction documentary film follows a National Science Foundation expedition to the Greenland ice sheet. The bivouac lasted for 25 continuous days. University of Arkansas Professor of Geosciences Matt Covington, Ph.D. teamed up with University of South Florida Professor Jason Gulley, Ph.D. to plan, propose, and ultimately accomplish the research goals of the expedition with the assistance of Ph.D. student Celia Trunz, M.S., and experienced expeditionary team member Vickie Siegel. As an observational-style documentary film, all scientific background information imparted herein is taken directly from interviews conducted with Professor Covington, to minimize opining.

The film begins in mid-flight, as …

How College Campuses Are Using Social Media During Severe Weather Events, Emmale Davis

Graduate Theses and Dissertations

This study explores how college campuses are using social media during severe weather events. This topic surfaced after a tornado devastated Moore, Oklahoma in May 2013 and those displaced flocked to the University of Oklahoma campus after a post made on Twitter went viral prior to an official message being sent out by the university. In order to further explore this topic, a qualitative phenomenological case study was conducted at the following sites: University of Alabama, Missouri Southern State University, University of Oklahoma, and Florida State University. This study included observations of social media posts on Facebook and Twitter on …

Gating Methods For High-Voltage Silicon Carbide Power Mosfets, Audrey Dearien

Graduate Theses and Dissertations

The objective of this thesis is to assess the challenges associated with driving Silicon Carbide (SiC) power devices, and to compare the potential gate drive methods for these devices which address those challenges. SiC power devices present many benefits that make them suitable for next generation automotive, power utility grid, and energy management applications. High efficiency, increased power density, and reliability at high-temperatures are some of the main benefits of SiC technology. However, the many challenges associated with these devices have prevented their adoption into industry applications. The argument is made in this thesis that the gate driver is a …

Effects Of Hydration And Mineralization On The Mechanical Behavior Of Collagen Fibrils, Marco Fielder

Graduate Theses and Dissertations

Bone is a composite biomaterial with a structural load-bearing function. Understanding the biomechanics of bone is important for characterizing factors such as age, trauma, or disease, and in the development of scaffolds for tissue engineering and bioinspired materials. At the nanoscale, bone is primarily composed of collagen protein, apatite crystals, and water. Though several studies have characterized nanoscale bone mechanics as the mineral content changes, the effect of water, mineral, and carbon nanotube (CNT) content and distribution in fibril gap and overlap regions is unexplored. This study used molecular dynamics to investigate the change in collagen fibril deformation mechanisms as …

Gis Modeling Of The Prominent Geohazards In Arkansas, Kyle Walker Rowden

Graduate Theses and Dissertations

The State of Arkansas is prone to numerous geohazards. This thesis is a twofold study of prominent geohazards in Arkansas: the first fold includes a novel triggerless approach for mass wasting susceptibility modeling applied to the Boston Mountains in NW Arkansas, and the second fold is a GIS-based regression modeling of the extreme weather patterns at the state level. Each study fold is presented in this thesis as a separate chapter embracing a published peer-reviewed paper. In the first paper, I have used the analytical hierarchy process to assign preliminary statistical weights to the most cogent variables influencing mass wasting …

Insect Light: Stories, Sacha Michael Idell

Graduate Theses and Dissertations

A collection of short stories. Literary fiction.

Geography Of The Middle East Through The Western Lens: A Survey Of Films Set In The Middle East And Filmed In The American Southwest, Jake Bryan Rowlett

Graduate Theses and Dissertations

Representation of cinematic geography is a struggle in the world of film: a power balance between the work of the filmmakers and the place itself. Often, the filmmakers tip the scales in their favor and the true nature of the place is lost in translation. Throughout the history of cinema, the geography of the Middle East has been manipulated into a vision designed for Western audiences that is strikingly disjointed from reality.

The foundation of modern Orientalist interpretations of the Middle East in film can be seen in the early decades of the film industry, through the “Biblical Epic,” and …

Pre-Season Vitamin D And Iron Levels As A Predictor Of Musculoskeletal Injury In Division I Athletes, Mariellen Katherine Veach

Graduate Theses and Dissertations

Context: Pre-season testing that includes the analysis of micronutrient serum levels in the blood has become a routine part of pre-participation examinations in collegiate football. Objective: Assess the predictability of vitamin D and iron serum levels as indicators of future injury during a subsequent competitive season for lower extremity sprains, strains, and fractures. Additionally, determine the effectiveness of vitamin D supplementation on increasing serum 25(OH)D levels and preventing injury. Design: Cohort Study. Setting: National Collegiate Athletic Association Division I football program. Participants: Football athletes (n=349) who underwent pre-participation examinations and participated in at least one of three competitive football seasons. …

The Effects Of Super-Dosing Phytase On Nursery And Grower Pigs, Joshua Paul Knapp

Graduate Theses and Dissertations

To determine the effects of super-dosing on pigs fed phosphorous and calcium adequate or deficient diets (Experiment 1); the optimum level of corn express phytase (CEP, Experiment 2); and the effects of xylanase/phytase on growth performance (Experiment 3) in pigs fed reduce nutrient diets, weaned pigs were blocked with initial body weight (BW) and allotted to dietary treatments. Treatments were: Positive control (PC), P/Ca adequate diets (NRC 2012); Negative Control (NC), low P (-0.15%) and Ca (-0.12%), +0, 1000, and 4000 FTU/kg of CEP in both PC and NC (Experiment 1); PC, P/Ca adequate diets; NC, decreased P (0.15%) and …

The Sleeping Giant: The Effects Of Housing Titan Ii Missiles In Arkansas And Kansas From 1962 To 1987, Michael Johnson Anthony

Graduate Theses and Dissertations

During the Cold War, thirty-six sites across Kansas and Arkansas were selected to house Titan II intercontinental missiles. These devices could strike enemy targets 8,000 nautical miles away all while hitting inside an area of one square mile. These technological marvels quickly became an indispensable part of President Kennedy and Defense Secretary McNamara’s ‘flexible defense’ strategy. While many authors have studied the ramifications of these devices on American foreign policy, few have researched the domestic implications of the missiles. This work looks to fill this void by investigating the Titan II missile program in Arkansas and Kansas from its construction …

An Investigation Into The Relationship Between Spirituality And Coping Responses Among Women With A Visual Impairment, Sandra Marie Bullins

Graduate Theses and Dissertations

The purpose of this study was to examine coping responses, specifically by women, and the relationship between those coping responses and a woman’s self-reported spirituality. The sample was comprised of women (n = 175) from the United States and 10 foreign countries. The results of a correlational analysis showed a strong positive relationship (r= 0.46, p<0.0001) between scores on the Spirituality Assessment Scale (SAS) and the Brief Cope (BC). There were also statistically significant correlations among subscales of the SAS and BC subscales. A multivariate analysis of variance was performed to evaluate the impact that select demographic variables might have on spirituality and coping responses. The results of the MANOVA showed no effect and were not statistically significant at alpha 0.1.

Experimental And Model-Based Terahertz Imaging And Spectroscopy For Mice, Human, And Phantom Breast Cancer Tissues, Tyler Bowman

Graduate Theses and Dissertations

The goal of this work is to investigate terahertz technology for assessing the surgical margins of breast tumors through electromagnetic modeling and terahertz experiments. The measurements were conducted using a pulsed terahertz system that provides time and frequency domain signals. Three types of breast tissues were investigated in this work. The first was formalin-fixed, paraffin-embedded tissues from human infiltrating ductal and lobular carcinomas. The second was human tumors excised within 24-hours of lumpectomy or mastectomy surgeries. The third was xenograft and transgenic mice breast cancer tumors grown in a controlled laboratory environment to achieve more data for statistical analysis.

Experimental …

Securing Soft Ips Against Hardware Trojan Insertion, Thao Phuong Le

Graduate Theses and Dissertations

Due to the increasing complexity of hardware designs, third-party hardware Intellectual Property (IP) blocks are often incorporated in order to alleviate the burden on hardware designers. However, the prevalence use of third-party IPs has raised security concerns such as Trojans inserted by attackers. Hardware Trojans in these soft IPs are extremely difficult to detect through functional testing and no single detection methodology has been able to completely address this issue. Based on a Register-Transfer Level (RTL) and gate-level soft IP analysis method named Structural Checking, this dissertation presents a hardware Trojan detection methodology and tool by detailing the implementation of …

How Do English Teacher Educators In Oklahoma Utilize The Secondary English Methods Course To Prepare English Teacher Candidates For Today’S Classroom?, Lara Elaine Searcy

Graduate Theses and Dissertations

The study focuses on how English teacher educators in Oklahoma utilize the secondary English methods course to prepare English teacher candidates in four thematic strands: a) instructional approaches, b) inclusion and alignment to national and state standards, c) focus on the state subject-area teacher certification assessment, and d) the course’s curricular changes made due to educational policies. Using a qualitative, descriptive, collective case study approach, the results describe how six instructors prepare English teacher candidates for today’s classroom in 2017.

A description of the secondary English methods course in Oklahoma is difficult to define by a single course title, but …

Evaluation Of The Effects Of Formaldehyde On Growth Parameters Of Broiler Chicks, Paula Johnson

Graduate Theses and Dissertations

Formaldehyde has been used as a disinfectant in poultry hatching cabinets to aid in controlling key pathogenic organisms, such as Salmonella and Escherichia coli (E.coli). There is some evidence that prolonged exposure of chicks to formaldehyde can reduce tracheal ciliary function and thus reasons to believe that exposure to formaldehyde, in the absence of pathogen challenge, may reduce chick vitality. It has been found that elevated temperatures during incubation may adversely affect body weights of broiler chicks, as well as post-hatch environmental heat stress on performance in poultry. Post-hatch environmental heat stress has been shown to impact performance in poultry. …

Collaborative Robotic Path Planning For Industrial Spraying Operations On Complex Geometries, Steven Brown

Graduate Theses and Dissertations

Implementation of automated robotic solutions for complex tasks currently faces a few major hurdles. For instance, lack of effective sensing and task variability – especially in high-mix/low-volume processes – creates too much uncertainty to reliably hard-code a robotic work cell. Current collaborative frameworks generally focus on integrating the sensing required for a physically collaborative implementation. While this paradigm has proven effective for mitigating uncertainty by mixing human cognitive function and fine motor skills with robotic strength and repeatability, there are many instances where physical interaction is impractical but human reasoning and task knowledge is still needed. The proposed framework consists …

Teacher And Administrator Perceptions Of The Teacher Excellence And Support System (Tess) In Arkansas, Allison Louise Byford

Graduate Theses and Dissertations

The purpose of this study was to investigate differences in Arkansas teachers’ and building-level administrators’ perceptions regarding the purpose of the Arkansas TESS teacher evaluation system, whether TESS authentically assesses teacher effectiveness, how teacher evaluation data are used, and how the TESS process supports learner-centered professional development. Additionally, the relationship of teacher and administrator demographics on their perceptions of TESS was explored. The results of this study highlight the differences in perceptions in all areas questioned along with misalignment in perceptions among teachers. Overall, the study points toward the need for clear communication and the cultivation of relationships among building …

In Vivo Structure-Function Analysis Of Drosophila Robo1, An Axon Guidance Receptor Critical For Midline Repulsive Signaling In The Embryonic Central Nervous System, Haley Brown

Graduate Theses and Dissertations

The repellant ligand Slit and its Roundabout (Robo) family receptors regulate many aspects of axon guidance in bilaterians, including midline crossing of axons during development of the embryonic CNS. Slit proteins are produced by midline cells and signal through Robo receptors expressed on the surface of axonal growth cones to repel axons from the midline. Disruption of Slit-Robo signaling causes ectopic midline crossing phenotypes in the CNS of a broad range of animals, including insects and vertebrates.

Drosophila Robo1 has a conserved ectodomain structure of five immunoglobulin-like (Ig) domains plus three fibronectin (FN) repeats. By utilizing a genomic rescue construct …

Evaluation Of Fresh-Market Potential Of Arkansas-Grown Fruit: Blackberries, Peaches, Table Grapes, And Muscadine Grapes, Molly Felts

Graduate Theses and Dissertations

Fresh-market produce is a major component of commercial market sales. However, shelf-life of fresh-market produce is limited, so evaluating postharvest potential (time from harvest to consumption) is critical. Fresh-market fruit can be impacted by many factors that deteriorate the quality of the fruit. Understanding the postharvest physiology of fruit can lead to better handling and storage conditions for extended shelf life and enhanced quality for the consumer. This research project was a collaborative effort within the University of Arkansas System Division of Agriculture between the Food Science and Horticulture Departments to evaluate the fresh-market potential of Arkansas-grown fruit. Physiochemical and …

A Proposed Approach To Hybrid Software-Hardware Application Design For Enhanced Application Performance, Alex Shipman

Graduate Theses and Dissertations

One important aspect of many commercial computer systems is their performance; therefore, system designers seek to improve the performance next-generation systems with respect to previous generations. This could mean improved computational performance, reduced power consumption leading to better battery life in mobile devices, smaller form factors, or improvements in many areas. In terms of increased system speed and computation performance, processor manufacturers have been able to increase the clock frequency of processors up to a point, but now it is more common to seek performance gains through increased parallelism (such as a processor having more processor cores on a single …

Exploring School Counselors’ Narratives Of Cacrep Accredited Online Education Programs, Rebecca Van Der Hagen

Graduate Theses and Dissertations

Online education is a growing part of academia. The number of online school-counseling programs is also increasing and beginning to include face-to-face and online programs. Little research describes online education and even less discusses online school-counseling programs. The purpose of this study was to examine and interpret participants’ experiences of being trained and graduating from a CACREP online school-counseling master’s program, as well as how their training prepared them for their current role as a school counselor. A qualitative inquiry was conducted to understand online school-counseling programs and reported how six professional school counselors perceived their online program with a …

From Policy To Practice: Exploring Principals’ Experiences In Facilitating The Implementation Of Cross Curricular Literacy Standards To Early Adolescents, Sherri Betton

Graduate Theses and Dissertations

Research has shown that early adolescents continue to need literacy development in middle school. Furthermore, states that adopted the current comprehensive school reform policy must implement literacy instruction across content areas in grades six through twelve. This study will explore principals’ experiences as they facilitate the implementation of cross-curricular literacy standards. Qualitative case study methodology will be used to examine the perceptions of seven middle school principals as they act as change agents in the implementation process.

Characterization Of Bacteriorhodopsin And Halorhodopsin Reconstituted In Lipid Bilayer Membranes, Joel Domkam Kamwa

Graduate Theses and Dissertations

Motivated to produce electricity with photon activated ion pumps, the main purpose of this work was to characterize the photosynthetic membrane proteins bacteriorhodopsin (proton pump) and halorhodopsin (chloride pump). The proteins were re-suspended in lipid bilayers. For this work, an experimental set-up was built which included: chambers for lipid bilayer formation and characterization, lasers for ion pump activation, and an AxoPatch electrophysiology system for small photocurrent measurement. Lipid bilayer membranes were formed using mostly folding method: folding two monolayers together. The membranes were characterized by their resistance, capacitance, and generated photocurrent. Photocurrent was generated upon illumination of lipid-protein membranes with …