2023 UMKC Dissertations - Freely Available Online
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Item Methods and experimental design for high power measurements of materials and devices(2023) Lancaster, John Berns; Caruso, Anthony N.; Hassan, Ahmed M.Current trends in Radio Frequency (RF) devices, such as the miniaturization of RF devices, wide-bandwidth communications, wide use of radar, communications, and positioning systems lead to an increased need to understand how materials and devices respond to the increasing power and wider bandwidth electromagnetic en- ergy associated with these trends. Precise measurement of the electronic properties of materials leads to robust design and an important probe into the physics of the underlying materials’ properties. The work discussed in this dissertation attempts to improve measurement approaches of electronic properties and effects testing of complex devices for incident high-power microwaves. The work demonstrates the variations in common low-power approaches and the consideration that drives the difference. High-power microwave measure- ments are a delicate balance between producing the high powers required for inter- esting aspects of materials and protecting the sensitive equipment required for the measurement. A novel high-power measurement of materials’ electronic properties is presented. The measurement is enabled by introducing an outer air-gap in a material measured in a coaxial airline. Although the introduced air-gap reduces the effective conductivity reversibly, the reduction in conductivity protects both the material under test and the instruments used.Item Factors that lead to principal retention: an arts-based narrative inquiry(2023) Veatch, Melissa Fae; Caruthers, Loyce Ellenor, 1947-Building principals are more than the face of the school. School administrators spend their time guiding teachers and students, collaborating with parents, establishing a responsive culture, and navigating accountability measures brought about by legislative policies enacted to provide equity to all students and ensure they are competitive in the global market. Over the past two decades, literature has begun to focus on the nationwide principal shortage in public education. With the growing emphasis on student outcomes and the complex social issues facing schools, principals are exiting the profession at a rapid pace, with the average shelf-life of new building leaders falling short of five years. Research suggests educational organizations focus on the retention of high-quality principals to ensure schools are able to meet the increasing demands of society. Using the qualitative methods of narrative arts-based inquiry, this study explores stories told by six Midwestern metropolitan principals with the hopes of illuminating what motivates them to remain in the principalship and how supported they feel in their leadership roles. Participants captured photographs representing their lived experiences and engage in journaling and interviews to develop rich context surrounding the image. Findings provide insight to educational organizations and post-secondary institutions on best practices and strategies for retaining and supporting building level leaders in the principal position.Item Delivery of sting agonist using lipid nanoparticles and discovery of anti-TIGIT peptides for cancer therapy(2023) Shaji, Sherin George; Cheng, Kun (Professor); Yao, XiaolanOver the past decades, cancer treatment has significantly advanced with the approval of new therapeutic entities aimed at treating this disease. However, these advancements have not universally benefitted all patients or different cancers due to the complexity of the tumor microenvironment found in these malignancies. Therefore, it has become crucial to understand the molecular and cellular mechanisms that cancer cells use to evade the immune system of their hosts in order to discover effective therapeutic interventions. Tumors can be classified based on their immunogenicity into two types: cold and hot tumors. Cold tumors like pancreatic cancer, glioblastoma, prostate cancer, and ovarian cancer exhibit a high number of immune suppressive cells including regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSC), and cancer-associated fibroblasts (CAFs). Additionally, they often lack significant infiltration of immune cells like T cells. On the other hand, hot tumors contain T cells and other immune cells within the tumor microenvironment. However, despite the presence of these immune cells, cancer cells utilize various mechanisms to render the immune cells, especially T cells, dysfunctional, thereby evading the immune system. One significant mechanism involves immune checkpoints, where cancer cells manipulate the interaction between a receptor on T cells and a ligand on cancer cells. This manipulation often involves the cancer cells overexpressing their specific ligands, leading to a phenomenon where T cells become exhausted and unable to effectively eliminate tumor cells. Cold tumors can be treated by converting them into hot tumors and then removing the brakes by inhibiting the receptor-ligand interaction. This dissertation focuses on two main research objectives related to the interventions mentioned above. The first research aims to deliver a STING agonist into a cold tumor using lipid nanoparticles. This delivery is intended to provoke an immune response that leads to the elimination of tumor cells. STING pathway agonism has shown promise in innate immune signaling to tune the tumor microenvironment toward an immunogenic phenotype by promoting immune cell infiltration, especially CD8+ T cells, in various types of cancer. The second research involves the discovery of anti-TIGIT cyclic peptides using phage biopanning to block the interaction between the receptor TIGIT and its high-affinity ligand, CD155. In clinical studies, inhibiting this pathway within the adaptive immune system has demonstrated the ability to reverse the exhaustion of T- and NK cells, thereby restoring their functional ability to elicit cytotoxic activity against tumor cells. Chapter 1 introduces the dissertation research, presenting the statement of problems and outlining the research objectives. Chapter 2 provides an in-depth literature review on pancreatic cancer, the STING-2’3’-cGAMP pathway activation, and TIGIT-CD155 checkpoint inhibition for cancer immunotherapy. Chapter 3 involves the development and characterization of 2’3 cGAMP lipid nanoparticles (cGAMP-LNP) using various in-vitro and in-vivo techniques. These biodegradable cGAMP-LNP were prepared by encapsulating 2’3' -cGAMP within a lipid-based system containing an ionizable lipid, LHHK, and co-lipids. The cGAMP-LNP were found to have higher cellular uptake, improved IRF activation, and endosomolytic activity compared to free cGAMP in various cell-based assays. The cGAMP-LNP demonstrated significant inhibition of pancreatic cancer growth in a mouse model. Furthermore, these LNPs displayed a good safety profile in both in-vitro and in-vivo testing. These results suggest that cGAMP-LNP is a promising therapeutic entity for cold tumors like pancreatic cancer. In Chapter 4, the dissertation illustrates the discovery of anti-TIGIT cyclic peptides using the phage display technique. A unique cyclic peptide library developed in our laboratory was utilized to identify cyclic peptides using a solution-based biopanning procedure. These peptides were selected for their ability to bind to the TIGIT protein and block the TIGIT-CD155 interaction. The blocking efficiency was analyzed using an in-vitro protein-based assay, and two peptides, CSCP-7, and CSCP-16, showed the highest blocking of TIGIT-CD155 interaction. Moreover, alanine scanning revealed the amino acids responsible for the blocking activity of the CSCP-16 peptide.Item The History of Elementary Literacy Instruction in the Kansas City Kansas Public School District from 1990 until 2022(2023) Holliday, Kendra Danielle; Davis, Donna M. (Donna Marie)This dissertation outlines a comprehensive research endeavor focused on the history of elementary literacy instruction in the Kansas City Kansas Public Schools (KCKPS) from 1990 until 2022. The research methodology combines historical analysis of artifacts, archives, and oral histories to answer the overarching research question, “What is the history of elementary literacy instruction in KCKPS from 1990 until 2022?” To provide historical context, the study delves into sub-questions, exploring the evolution of literacy instruction in the state of Kansas from 1844 to 1990, and the influence of race and class on literacy instruction prior to 1990. This study documented this important history for the first time, starting with the early history of education and schooling in Kansas, progressing to the evolution of education in the state from 1900 until 1954, and examining the post-Brown v. Board of Education era, with a specific focus on KCKPS. This study also investigates the evolution of literacy instruction post-Brown in KCKPS, the curriculum pedagogical approaches, and major professional development initiatives pertaining to literacy instruction. This study concludes by discussing the implications of the historical findings on future educational practice, emphasizing the connections between past and present literacy instruction, and highlighting the impact on education in KCKPS. The study draws conclusions about how literacy instruction has evolved and examines its implications for educators, professional development, and the implementation of culturally responsive teaching practices, grounded in evidence-based research. Overall, this research project presents a comprehensive exploration of the history of elementary literacy instruction in KCKPS, shedding light on the factors that have shaped its development and providing valuable insights for educators and policymakers in the present and future.Item ADInsight: A Multimodal and Explainable Framework for Alzheimer's Disease Progression and Conversion Prediction(2023) Velazquez, Matthew J.; Lee, Yugyung, 1960-; Gaddis, Monica Louise, 1955-ADInsight represents the crux of this dissertation, introducing an integrated and explainable framework centered on predicting Alzheimer's disease (AD) conversion, particularly for those at the early stage of mild cognitive impairment (EMCI). Beginning with an examination of models grounded in individual research modalities, such as clinical data and advanced imaging, the research underscores the potential and limitations of singular approaches. As a response to these findings, this dissertation introduces a multimodal ensemble conversion prediction model that combines Diffusion Tensor Imaging (DTI) scans with clinical data. This ensemble not only increases the accuracy of predictions but is also notable for its dedication to explainability, bridging the gap between intricate neural network predictions and understandable medical interpretations. Upon further exploration a unique framework is revealed, combining the advantages of Random Forest Regression alongside the latest over-sampling methods. This framework unravels the intricacies of AD's nonlinear progression, leading to the formulation of patient progression groupings. The dissertation is then concluded with the Cognitive Visual Recognition Tracker (CVRT) application. This application marks an exploration into cognitive focus and visual identification, which are essential elements in the development of Alzheimer's disease. Benefiting both clinicians and patients, CVRT paves the way for innovative treatment strategies. In summary, our ADInsight framework provides a novel approach to understanding and predicting the progression of AD, providing a beacon of hope and knowledge in the ongoing struggle against this debilitating condition.