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Defining and Measuring Complex PTSD: A Comparison of the International Trauma Questionnaire and the Self-Report Inventory for Disorders of Extreme Stress
No full textThe inclusion of complex posttraumatic stress disorder (CPTSD) in the eleventh edition of the International Classification of Diseases (ICD-11) was a landmark development for the field of traumatic stress. This followed decades of iterations of proposed diagnostic criteria, beginning with Herman’s (1992a) foundational conceptualization of CPTSD and continuing with disorders of extreme stress not otherwise specified (DESNOS), which was proposed and evaluated for inclusion in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Aligned with the guiding principle of ICD-11 that diagnostic criteria for mental disorders be limited to core symptomatology in order to improve clinical utility, CPTSD in ICD-11 is narrower than previous conceptualizations of CPTSD. The present study sought to examine shared and distinctive aspects of DESNOS and ICD-11 CPTSD, as measured by the Self-Report Inventory for Disorders of Extreme Stress (SIDES-SR) and the International Trauma Questionnaire (ITQ), respectively. These contrasting conceptualizations of CPTSD were compared through a categorical diagnostic approach (i.e., examining diagnostic agreement and differential symptom patterns between diagnostic groups) and a dimensional measurement-based approach (i.e., assessing the convergent and discriminant validity and incremental predictive validity of the SIDES-SR and ITQ). Participants were trauma-exposed college students (N = 743) who completed a large battery of questionnaires, including the SIDES-SR and ITQ. Analyses for the categorical aim demonstrated differential prevalence rates of CPTSD as derived from the two measures, fair diagnostic agreement at the full-scale level, and group differences on external symptom measures (e.g., PTSD, dissociation, suicidality, self-harm, relationship disturbance), with those meeting criteria for both the SIDES-SR and the ITQ generally demonstrating higher symptom severity than those who met for the ITQ alone. Analyses for the dimensional aim demonstrated generally comparable levels of association with external measures of some domains of CPTSD (e.g., relationship disturbance), but stronger levels of association for the SIDES-SR relative to the ITQ for other domains of CPTSD (e.g., dissociation). Additionally, results of multiple hierarchical regressions demonstrated that the SIDES-SR accounted for additional unique variance in external measures of domains of CPTSD beyond that explained by the ITQ, even for domains included in the ITQ (e.g., affect dysregulation). Overall, the results suggest that the ITQ could benefit from expansion to include additional symptoms of CPTSD, such as that reflecting a greater severity of affect dysregulation. Additional findings and implications are discussed
An Examination of Universal Design for Learning and its Impact Potential on Support Staff Practices within Higher Education
Get PDFAs higher education institutions strive to create more inclusive learning environments, the role of academic support professionals in meeting the needs of students with disabilities has become increasingly critical. This study examined the attitudes and actions of faculty advisors, professional academic advisors, and academic coaches in supporting students with disabilities in higher education. The research explored differences across these roles, the impact of personal connections with individuals with disabilities, and motivations for engaging in professional development related to Universal Design for Learning (UDL). A survey instrument designed to assess attitudes and actions related to accessibility and inclusion was distributed to higher education professionals in academic support roles. Statistical analyses were conducted to examine differences among participants and the relationship between personal experiences with disability and professional engagement. Findings revealed significant differences in attitudes and actions between professional academic advisors, faculty advisors, and academic coaches. Professional advisors demonstrated greater engagement with accommodations and inclusive advising strategies, while faculty advisors and academic coaches exhibited lower levels of participation. Personal connections with individuals with disabilities were associated with increased direct support actions but did not significantly impact motivation to engage in UDL-related professional development. These results highlight the need for structured training and institutional policies that ensure all academic support professionals are equipped to foster inclusive learning environments. Future research should explore qualitative perspectives and the broader application of UDL in higher education
A Landscape Scale Analysis of Vegetation Change within the Blast Zone of the 1980 Mount St. Helens Volcanic Eruption through 2024
No full textThe Mount St. Helens eruption of 1980 resulted in a catastrophic loss of vegetated land within the Pacific Northwest. This study focused on the vegetation throughout the blast zone with a particular interest in comparing vegetation growth patterns on different management areas and exploring environmental drivers of this growth. Using the Normalized Difference Vegetation Index (NDVI) for the years 1984 – 2024 in Emerging Hot Spot Analysis (EHSA), the results showed that vegetation growth was initially greater on properties where there were more remediation efforts following the eruption. In the later years of analysis, the EHSA identified locations on WEYCO where timber harvest was increasing. Therefore, WEYCO is experiencing a more inconsistent rate of growth while NVM continues to have an increase of vegetation growth each year. Multiple Linear Regression analysis (MLR) identified relationships between environmental variables such as slope, hillshade, elevation, and ash depth and vegetation attributes consisting of NDVI and canopy height. This analysis led to the conclusion that areas with greater canopy height and higher NDVI values could be found on steeper slopes with more sunlight exposure and lower initial volcanic ash deposits. These results point towards the potential for greater growth where management is more involved in reforestation efforts in this study area or other similar study areas. Additionally, care should be taken to focus efforts on gentle slopes, higher elevations, or areas where ash is present
Assessment of Beauveria bassiana Virulence Across Diverse Insect Hosts and Understanding the Role of Genes Contributing to Insect Virulence
No full textBeauveria is an entomopathogenic fungus known to infect and kill wide range of insects through cuticle penetration and release of variety of toxins. The major focus of this study is to evaluate the efficacy of nine Beauveria isolates against diverse insect hosts and identify highly virulent isolates. In Chapter 2, conducting virulence assay with nine Beauveria isolates against diverse insect hosts, several highly virulent isolates among insects tested were identified. ARSEF 2597 displayed the highest virulence across all the insects in the orders Lepidoptera, Coleoptera, and Blattodea. The isolates exhibited varying degrees of efficacy with most isolates not displaying host specificity. However, with Aedes aegyptii larvae, host specificity was observed, with isolate ARSEF 8028 demonstrating significantly high level of virulence. Some isolates demonstrated virulence across several orders suggesting wide host range, while some exhibited higher level of virulence against specific insect suggesting narrow host range and host specificity.
In Chapter 3, a phylogenetic comparison between the seven Cry-like genes of B. bassiana ARSEF 2860 and 71 Cry genes from various species and subspecies of Bacillus thuringiensis (Bt) revealed a strong phylogenetic relationship with Cry 2, Cry 11, and Cry 18 families indicating the Cry-like genes may have a conserved function for virulence. Mutants were generated for all the seven Cry-like genes using CRISPR/Cas9 to evaluate their roles in insect virulence. Virulence assay conducted with mutants of each of the seven different Cry-like genes with the G. mellonella and H. zea larvae demonstrated reduced virulence for mutants of the two Cry-like genes, BBA_03803 and BBA_08516 suggesting their potential role in insect virulence
The Influence of Practice Design Using Task Constraints to Develop a Pitch With Vertical Break in Softball
No full textGroups of softball pitchers seeking to develop a movement pitch practiced under two different practice conditions. One group practiced using instructions centered on achieving an idealized movement pattern to create break on the ball (Traditional). Another group practiced using a manipulated task constraint with the objective of creating break on the ball without instructions for executing the pitch (Constraints-led approach). Based on frameworks from ecological and nonlinear dynamics, the Constraints-led approach was designed to enable pitchers to assemble movement solutions to satisfy task constraints while exploring functional movement patterns. The Constraints-led approach was compared to the Traditional approach which often overlooks the interacting dynamics of individual, environmental, and task constraints on motor behavior. Participants were randomly assigned to either condition. Initially, participants pitched peel drop balls during a pretest block of 15 pitches to collect baseline measures. Next, participants pitched three blocks of 15 peel drop ball pitches under their assigned condition which was followed by an immediate post/transfer test where the conditions were removed. Distal pitching-arm kinematics and ball metrics were obtained during the session. Each group performed similarly on the immediate post/transfer test assessed by average vertical break. The Traditional group showed greater mean vertical break during practice. Descriptive improvements in break occurred across practice for each group. Descriptively, the Constraints-led approach showed higher arm configuration variability during practice while the Traditional group reduced arm configuration variability, displaying more of a fixed movement pattern. Hand height variability at ball release showed to be a relatively stable parameter across blocks and similar between groups. The Traditional group displayed improved performance during practice, however when the task constraints during practice were removed performance was comparable
Barriers Facing Undergraduate Atmospheric Science Education and Southeast US Oyster Farmers
No full textThe goal of this dissertation research is to provide understanding to the growing body of literature related to barriers in both undergraduate atmospheric science education and Southeast US oyster farming industry through three separate chapters. The first chapter focuses on a study that examines the factors influencing sense of belonging during undergraduate atmospheric science studies. The study utilizes an embedded mixed methods approach in the form of a survey with current and former undergraduate atmospheric science students serving as participants. The survey examines participants’ sense of belonging during undergraduate studies across demographic groups including gender, race, ethnicity, and education level. Study two examines sense of belonging in undergraduate atmospheric science departments through semi-structured interviews with a subset of the survey participants. The interviews provide a deeper understanding of an individual’s sense of belonging during undergraduate studies. The results and responses from these interviews help to provide recommendations to departments to improve undergraduate departments’ climate and culture. Improving students’ sense of belonging is vital to attract, retain, and sustain a more varied atmospheric science community. Study three focuses on the Southeast US oyster farmers’ perceptions of climate change and extreme weather events and their impacts to the industry. Similarly, this study uses a mixed methods approach with a combination of a survey and semi-structured interviews deployed to oyster farmers across the Southeast US. Overall, the goal of this dissertation is to better understand and begin to break down the barriers impacting atmospheric science undergraduate education and oyster farming industry
Synergistic Effects of Volumetric Defects and Notch Geometry on the Fatigue Behavior of Additively Manufactured Metallic Materials
No full textIn this dissertation, the synergistic effects of volumetric defects and notch geometry on the fatigue behavior of additively manufactured (AM) metallic materials were investigated. Factors influencing fatigue crack initiation and short crack growth behavior were identified and assessed. Both experimental and numerical techniques were utilized to understand the notch fatigue behavior. During experimentation, AlSi10Mg and 17-4 precipitation hardening (PH) stainless steel (SS) specimens with varying geometry types (cylindrical and flat), notch root radii, ρ, ligament widths, w, and volumetric defect contents were used. These specimens were tested under uniaxial cyclic loading, and their fracture surfaces were analyzed to identify the crack initiation site and investigate the fatigue failure mechanisms in different notch configurations. Irrespective of the material or the geometry type, ρ0.1 (specimens with ρ of 0.1 mm) showed shorter fatigue lives with lower scatter compared to ρ5 and ρ50 specimens. For ρ0.1 specimens, significant cyclic plastic damage at the notch root, due to the high stress concentration, caused critical crack initiations.
For cylindrical specimens, ρ5 and ρ50 showed similar fatigue lives for AlSi10Mg; however, for 17-4 PH SS, the latter showed longer fatigue lives. It was likely due to the influence of wider variation in the critical defect features in AlSi10Mg than 17-4 PH SS, on the crack initiation behavior. Notch geometry as well as the critical defect’s size and location (within the cross-section and height relative to the notch root plane) influenced the fatigue behavior of cylindrical notched specimens. In the case of flat specimens, there was an additional influence of microstructure on the fatigue behavior of near-defect free 17-4 PH SS specimens. Delta ferrites (δ-Fe) acted as weak points in the microstructure, resulting in the formation of microcracks, and eventually crystallographic facets as the crack initiation site. Larger w resulted in shorter fatigue lives for ρ0.1 and ρ5 AlSi10Mg and 17-4 PH SS flat specimens. Specimens with w of 10 mm induced higher cyclic plastic damage at the notch root than 5 mm, thus promoting crack initiation and early failure. In specimens with minimal plasticity at the notch root, i.e., ρ5 and ρ50 specimens, mode-I stress intensity factor (SIF) of critical features calculated based on linear elastic fracture mechanics (LEFM), i.e., Murakami’s approach, correlated well with experimental fatigue lives. However, in specimens with significant plasticity at the notch root, i.e., ρ0.1 specimens, equivalent plastic strain at the notch root correlated well with the experimental fatigue lives.
Based on LEFM, fatigue criticality of volumetric defects in AlSi10Mg and 17-4 PH SS notched specimens were assessed using a non-destructive technique, i.e., X-ray computed tomography (XCT). Assuming a defect-crack equivalency and accounting for local stress fields using linear elastic finite element analysis, mode-I SIF of defects detected via XCT was calculated and used to represent their fatigue criticality. For validation, ρ5 and ρ50 cylindrical and flat specimens were XCT scanned and tested; all crack initiating defects fell within the 99.3 percentile of the highest SIF defects in the respective notched specimens for AlSi10Mg and 17-4 PH SS.
The behavior of short cracks initiated from the volumetric defects, including their growth and arrest, under the influence of the notch stress fields, were believed to have a significant influence on the fatigue lives of notch members. Utilizing a numerical modeling technique, the short crack growth behavior of cracks initiating from volumetric defects in notched specimens was investigated. It utilized the effective SIF of cracks, put forth by El-Haddad, to assess the short crack growth behavior. Notch geometry, defect’s size, shape, and location influenced crack arrest behavior. The minimum effective SIF of cracks, at the crack arrest, was used to obtain the fatigue notch factor. Utilizing the fatigue notch factor-based framework, fatigue lives of flat notched specimens with varying ρ were predicted. This was validated using laser powder bed fused AlSi10Mg and 17-4 PH SS flat notched specimens with ρ of 5 mm and 50 mm. For AlSi10Mg, 95% of all fatigue life predictions fell within the scatter band of 3, and 100% for 17-4 PH SS
International Timber Markets
No full textThe aim of this dissertation is to explore three prominent topics of international timberland market research. Chapter One examines whether United States, South and Central America, and Oceania timberland markets have integrated per-acre timberland values. Chapter Two focuses on international trade relations between the leading tropical sawnwood importing and processing European Union countries – France, Germany, and Italy – and the Sub-Saharan African countries through the evaluation of import demand elasticities. Chapter Three investigates “price-leading” behavior in global and U.S. regional markets utilizing the Granger-Causality approach
The Power of Active White Space in Brand Logo Designs: An Application of Processing Fluency and Construal Level Theories
No full textA logo is an essential part of brand identity. Active white space (AWS) has been incorporated in many brand logos with an assumption that it would help brand communication, but little empirical research has examined this assumption. To address this literature gap, this study experimentally investigated how varying proportions of AWS in brand logos would impact consumer perceptions of the logos based on the processing fluency theory and construal level theory. An online experiment employing a 2 (AWS proportion: high vs. low) × 2 (logo design: designs 1 vs. 2) between-subjects design was conducted with a convenience sample of 233 Auburn University students. Results indicate that AWS proportion positively influenced consumers’ attitude toward a logo through enhancing the visual fluency and aesthetic appeal of the logo, while it did not impact perceptions of the psychological distance and prestige appeal of the logo. Managerial and theoretical implications are discussed
Development of a Reinforcement Learning Environment for Connected Autonomous Vehicle Performance Optimization and Security Analysis
No full textThe global presence of Connected and Autonomous Vehicles (CAVs) has seen an
exponential increase over the last decade. This presence ranges from researchers testing their
performance capabilities to studies assessing new security dynamics brought by CAVs. However,
due to the costs of purchasing and maintaining CAVs, as well as in-field safety concerns related
to safety precautions for test subjects, there is a need to have a flexible cost-effective tool for
analyzing CAV impacts. This is the focus of this thesis. A literature search of the current state-ofthe art in autonomous-vehicle-centric simulators is provided in chapter 2. It was found that by
better understanding machine learning paradigms – namely, various reinforcement learning (RL)
methodologies – CAV performance and security assessment can be enhanced through continuous
action space adaptation. Various RL algorithms can be beneficial for environmental exploration
and optimization. After conducting an in-depth literature review and brief creation of a prototype
reinforcement learning environment, Proximal Policy Optimization (PPO) was selected for its
proficiency in both discrete and continuous action spaces. It was found that PPO provided better
precision in high-speed driving actions with stochastic considerations than value-based
deterministic methods and showcased the approximation of Actor-Critic Neural Network
Architectures. PPO driven vehicle agents were trained in small to large scale environments using
spatiotemporal performance metrics. The results identified potential road vulnerabilities,
provided a better understanding of CAV performance, and constructed a viable algorithm
framework that can be used in future analyses