Self-report measures of bullying have recently been under scrutiny due to limited evidence of their psychometric properties. Nevertheless, they continue to be the main tool for estimating prevalence of bullying behavior in schools, as well as evaluating the effectiveness of bullying prevention programs. This study examined the psychometric properties of the Peer Relations Questionnaire, a widely used self-report measure of bullying. In an attempt to evaluate the internal consistency of the Victimization scale and test-retest reliability of the (PRQ) as a whole and across grade levels, it was administered twice to third and fourth, sixth and seventh, and tenth and eleventh graders with an eight week interval. Results showed moderate reliability with middle school (69.4% correspondence) and high school (74.8% correspondence) students and low reliability for elementary students (62.3% correspondence). Across all age groups, the PRQ had a test-retest reliability of 69% correspondence. Internal consistencies for the Victimization scale were high across all grade levels. These results suggest the PRQ is most effective when used with older students, although its reliability estimates have room for improvement in all groups. Future research is needed to evaluate other commonly used instruments in the field to support their use in the collection of bullying data. / Thesis (M.Ed.) - Wichita State University, College of Education, Dept. of Counseling, Educational, and School Psychology

This research studied the potential impact of teachers’ attitudes and perceptions on the under representation of African American students in gifted education programs. The study was conducted in an urban, Midwest school district with 322 elementary school teachers participating. Results indicated that, in general, teachers perceive that African American learners have a more difficult time learning than do students from other ethnic groups. The mean score for White teachers was significantly higher than the mean scores for Minorities. Results also indicated that, in general, teachers perceive that, although African American learners are served at a higher rate than White students in special education programs, they are not misidentified, and thus belong in those programs when they are placed there. The mean scores of Minority teachers, teachers over the age of 35, and teachers who had taught more than 15 years were significantly lower, although their scores still indicated a general agreement with the idea that they are not misidentified. The final significant finding was that younger teachers (22 – 35 years of age) felt that they have had more adequate training in how to teach students from different cultural backgrounds. This did not, however, seem to make any difference in their attitudes toward African American learners’ ability to learn or misidentification. / Thesis (M.Ed.)--Wichita State University, College of Education, Dept. of Counseling, Educational and School Psychology

The primary purpose of this study was to evaluate the speech and language abilities of typically developing Head Start children ages, 3 years; 8 months to 5 years; 7 months. Three goals were addressed during this study. The first was to determine communication characteristics of typical Head Start children at three different age levels. The second was to determine whether differences between genders and among age groups were significant. The third was to determine which variables (i.e., phonological deviations, percentages of consonants correct, mean length of utterances, receptive vocabulary, age, gender) significantly predict the children’s percentages of intelligible words in connected-speech samples. Results indicated that there was considerable variability in the skill levels of the typically developing children for all of the areas assessed. ANOVA results indicated differences were not significant between boys and girls or among the three different age groups. Results of a stepwise multiple regression analysis indicated that two variables predicted percentages of intelligible words in connected-speech samples: (a) percentages of consonants correct accounted for the greatest amount of variance followed by (b) mean length of utterances. Correlation results indicated that all variables (i.e., phonological deviations, percentages of consonants correct, mean length of utterances, receptive vocabulary, age), except gender, were significantly correlated with percentages of intelligible words. Data analysis revealed a possible plateau of intelligibility and expressive language skills at the older age group levels. These findings may be important to SLPs and Head Start staff when considering speech/language program development and curriculum structure. / Thesis (Ph.D.)--Wichita State University, College of Health Professions, Dept. of Communication Sciences and Disorders

Major technological advances using composite materials in airframe components to improve performance and energy efficiency have been achieved in the last 50 years. For the first time, these materials are being introduced in load-bearing wing and fuselage structures. Durability, repairability, and maintainability are essential elements in the continued airworthiness of these components. Weak interfacial bonds between composite adherends are not detectable with the current inspection methods and may deteriorate in service, possibly leading to the component’s failure. In-service experience with, and interfacial degradation of, bonded repairs to metallic substrates is well documented in the literature; there is a growing need to investigate these mechanisms with composite substrates as well. In-service experience is necessary to understand the durability of the parent construction and the requirements for repair subsequent to damage. In the first phase of this research work, teardown studies were conducted to evaluate the long-term durability of two composite components with service history: a B737 horizontal stabilizer and a Beechcraft Starship aft wing. Results indicate that both structures maintained their structural integrity, with no evidence of detrimental degradation or deterioration. Results also revealed moisture levels near equilibrium in both components. The fundamental objective of second phase of this work was to investigate mechanisms of interfacial degradation in a bonded repair to a composite substrate resulting from a compromised parent interface or a defective interphase, subjected to mechanical loading and the environment. Weak interfacial bonds were investigated using a thermodynamic-based approach to surface analysis followed by a post-repair residual strength evaluation of these repairs. The case studies performed demonstrated that exposure to repeated loading and the environment results in further deterioration of the originally deficient bonds. / Thesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering

This study explored the relationship between ways of knowing and attitudes toward diversity awareness and acceptance. The purpose was to determine whether there was a link between individuals with a higher propensity for either of the two epistemological orientations, connected knowing or separate knowing, and their ability to be accepting and understanding of others who are different from them. Important to this study was also the investigation of the potential factors that predict diversity awareness the most. Connected knowing, separate knowing, gender, age, and ethnic status were the five predictor variables used during exploration. There were a total of 211 undergraduate and graduate participants from two Midwest universities, between the ages of 18 and 58. Participants completed the Attitudes Toward Thinking and Learning Survey (Galotti, Clinchy, Ainsworth, Lavin, & Mansfield, 1999), the Miami University Diversity Awareness Scale (MUDAS) (Mosley-Howard, Witte, & Wang, 2011), a vocabulary test, and demographic questions. Main analyses revealed a significant positive correlation between ways of knowing and all of the MUDAS subscales. Contrary to what was expected, analyses also revealed a significant positive correlation between separate knowing and four MUDAS subscales. Among the significant predictor variables found were: connected knowing, separate knowing, and gender. Exploratory ancillary analyses revealed three significant differences between men and women. Specifically, differences in means were found for separate knowing, value/appreciation, and intercultural interaction. / Thesis (M.Ed.)--Wichita State University, College of Education, Dept. of Counseling, Educational Leadership, Educational & School Psychology

An experimental methodology is presented to determine tool-part frictional interaction of composite parts and the structural integrity of sandwich structures when subjected to temperatures and pressures similar to those of autoclave processing. This methodology includes the development of a testing rig that mimics the deformation mismatch between tools and parts, and quantifies shear stress—that is, tool-part friction or shear stress of sandwich structures. Discrete and continuous friction characterization was performed to validate this testing methodology, and a semiempirical mathematical model was obtained to predict the tool-part frictional interaction as a function of different manufacturing variables including temperature, pressure, and part length. Moreover, a characterization of the shear strength of sandwich structures is presented where results indicate a strength decrease when temperature and pressure increase following an inverse-exponential trend for both cases. Furthermore, an alternative methodology to measure thermal properties of composite materials by radiation known as light flash analysis (LFA) is used to characterize diffusivity, conductivity, and specific heat of composite materials tested at typical manufacturing temperatures. Accordingly, this research portrays the mathematical considerations required for the testing of anisotropic materials. Thermal properties of cured composite samples with three different fabric weaves and two resin formulations were obtained, and results indicate that conductivity, diffusivity, and density are strongly influenced by testing temperature, fiber configuration, and fiber volume fraction. / Thesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering

In this dissertation, a broad spectrum of research in fractional-order (FO) proportional-integral-derivative (PID) controllers is directed to fundamental control problems such as stability, performance, and robustness. First, nominal stability was considered by finding all the possible FO PID controllers that stabilize a closed-loop system with respect to arbitrary values of the fractional orders λ and μ of the FO PID controller. The findings are presented on the (Kp, Ki), (Kp, Kd), and (Ki, Kd) planes. In order to meet nominal performance specifications, a sensitivity function weight was introduced and FO PID controllers were sought to meet the weighted sensitivity constraint. This led to a complete set of possible values of FO PID parameters that satisfy the given performance specifications. Following the nominal stability and performance, robust stability and performance were investigated. For a robust stability requirement, a multiplicative weight was selected to bound all multiplicative errors of a closed-loop system. Such FO PID controllers allow the closed-loop to remain stable for all the sets of perturbed plants. Nominal performance and robust stability are the prerequisite conditions for the robust performance of a closed-loop system. Though, in robust stability analysis, the closed-loop system was designed only to remain stable, it was required not only to remain stable for all the uncertain plants but also to satisfy given performance specifications in the robust performance analysis. A substantial contribution of this research is the establishment of a complete set of solutions for FO PID controllers, with respect to nominal stability and performance and robust stability and performance. The use of frequency response of a system makes it possible to apply the results presented in this dissertation even when a system transfer function is not known or unavailable, as long as the experimental frequency data of a system can be obtained. / Thesis (Ph.D.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science

The anthrax toxin secreted by Bacillus anthracis is the major virulence factor of anthrax disease. The protective antigen (PA) component of the toxin binds to the von-Willebrand factor A (vWA) domain of capillary morphogenesis protein 2 (CMG2), followed by proteolytic cleavage into two fragments of 20 and 63 kDa. The 63 kDa fragment oligomerizes into heptameric or octameric structures collectively termed “pre-pore”, these are endocytosis, and within an acidified endosome undergo a large conformational change to form a membrane spanning pore, resulting in the entry of edema factor (EF) or lethal factor (LF) into the host cell. Although the general pathway of anthrax toxin entry has been elucidated, many details still remain unknown. The key problem is how the heptameric PA-receptor complex initiates formation of the pore and what happens to the receptor after pore formation; is it still bound or dissociated? Understanding the process of anthrax toxin pore formation and the role of the receptor could provide more clues in the investigation of the mechanism of anthrax toxin action and suggest new strategies for inhibiting toxin action. In my research work, we studied the pH dependent pore formation in presence of receptor, using fluorescence. We show that during the process of pore formation at low pH, a specific tryptophan residue, W346 (located in domain II), comes closer to domain IV, and then receptor dissociates from PA63. Our results show that, even in case of D425A PA63 (as a control, not forming a pore), receptor dissociates at the same pH required for pore formation. This mechanism suggests that movement of domain IV away from domain II must occur quickly, followed by a collapse in which the two domains coalesce, and receptor dissociation is induced by low pH. / Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry

Insect exclusion experiments have demonstrated that insect herbivores can reduce host plant fitness through both direct and indirect mechanisms. I did an experiment on Cirsium altissimum (tall thistle), whose apical meristems are attacked by the larvae of Platyptilia carduidactyla (artichoke plume moth), during 2012 to determine whether apical meristem mining affects C. altissimum fitness and to determine whether these effects arise indirectly through plant-mediated effects on floral visitation. In a restored tall grass prairie, 180 tall thistle adult plants were randomly selected and assigned randomly to treat with insecticide, water and unmanipulated control. On these plants, I quantified effects of apical meristem mining on plant architecture, flowering phenology, flower visitors’ activity and seed production. Apical meristem miners affected several aspects of plant architecture, including reducing plant height and increasing the proportion of axial flower heads, and many aspects of plant flowering phenology, including delaying flowering and date of maximum floral display. Apical meristem miners significantly decreased C. altissimum lifetime seed production, showing their strong effects on plant fitness. Bombus pensylvanicus and Melissodes desponsa were the most common visitors on C. altissimum flower heads. No strong effect of apical meristem miners was reported on the behavior of bee (Apidae) species, which may have resulted from the availability of the major visitors of C. altissimum flower heads throughout the flowering season. Overall, apical meristem mining strongly affected the plant reproduction success but no evidence was found to suggest that these effects on fitness of C. altissimum arose through changes in floral visitation. Being a monocarpic plant with little seed bank, reduced seed production by C. altissimum may translate into smaller population sizes. / Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Biological Sciences

Metastatic cell motility, namely breast cancer, has been shown to be regulated in part by the protein palladin. Palladin is a recently described actin binding and bundling protein whose expression level is related to metastatic cancer cell motility. Palladin plays a role in the regulation of actin, a highly abundant protein within a cell, which acts as a cell’s skeleton. Actin is also the structural basis of invasive cellular structures known as invadopodia, which cross the extracellular matrix and allow cells to invade surrounding tissue structures. Palladin has been shown to regulate actin bundles within these invasive structures. Further studies have shown that Akt1, a prominent and highly studied protein kinase, phosphorylates palladin at a linker region between its immunoglobulin domains that are critical for actin bundling. Our work builds upon initial cell-based assays which show that normal cell function is altered when phosphorylation of palladin is misregulated. We utilized biochemical assays to quantify how phosphorylation of palladin affects the structure and function of actin to further understand both of their roles in cancer cell motility. / Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry