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EQUITABLE OPPORTUNITIES TO PARTICIPATE IN ADVANCED MATHEMATICS IN URBAN SCHOOLS
Get PDFThis dissertation investigates equitable opportunities for participation in advanced mathematics among students in urban schools, focusing particularly on Baltimore City Public Schools. It addresses the significant disparities in advanced mathematics course offerings and enrollment between predominantly Black urban schools and their counterparts. Despite being 15.1% of the total high school enrollment in the United States, Black students account for only 6.3% of all AP mathematics course enrollment. This disparity is linked to systemic issues that historically limit access for Black students which contributes to a wide range of negative outcomes.
Using the theoretical frameworks of Ecological Systems Theory and Critical Race Theory, the research explores the multi-layered influences on mathematics participation, including societal, school, teacher, and peer factors. These factors are investigated in a literature review and then organized to show the ecology of experience that influences disparate access to advanced math.
An investigative empirical study using a mixed-methods design explores some of the most salient factors identified in the literature review. Ultimately the study highlights the negative impact of deficit paradigms, implicit biases, and structural inequalities within educational institutions. However, it also identifies many positive influences from within students’ peer and family communities. It is shown how these positive influences resist deficit paradigms and foster resilience and mathematical empowerment.
The dissertation proposes a comprehensive program to increase advanced mathematics participation, emphasizing the need for systemic change at both the policy and school levels. By aligning educational policies with state-level initiatives and leveraging community engagement, the program aims to provide sustainable, equitable access to advanced mathematics for all students, particularly those in Baltimore City
LASALLIAN MISSION LEGACY AND INTEGRATION IN A SECONDARY SCHOOL
Get PDFThis research seeks to understand the legacy of mission in a Lasallian secondary school, and how that mission is understood by its current faculty and integrated into classroom content. Lasallian schools, founded by St. John Baptist de La Salle, are founded on a five-pillar mission: faith in the presence of God, respect for all persons, inclusive community, quality education, and concern for the poor and social justice. First, a literature review is undertaken to comprehensively discuss the history of Catholic school and schooling in the United States and identify several key factors in mission legacy and integration. These factors are teacher factors, Catholic schooling, professional development and historic events. Next, the reader is guided in situating the key factors in two theoretical frameworks: actor–network theory and institutional ethnography. This is followed by a discussion of the ethnographic research conducted at one Lasallian secondary school including the methods of the research and a discussion of the results. The reader is then guided through a proposed applied project to address the gaps found in the research. Lastly, a three session professional development on Lasallian mission legacy and integration is presented
CD11c positive T cells as prognostic marker in melanoma
Get PDFWith an increasing global burden, melanoma is an immunogenic skin cancer characterized by a high mutational burden and immune cell infiltration. Recent developments in cancer immunotherapies such as immune checkpoint inhibitors and neoantigen-based therapeutic vaccines have demonstrated survival benefits in clinical applications. However, issues persist in terms of low response rate and limited immunogenicity. Previous studies have shown that a vaccine conjugating MIP3α to melanoma associated antigens Gp100 and Tyrosinase-related protein 2 (MGpTrp2) delivered by intramuscular electroporation (EP) leads to delayed tumor growth, with CD11c+ CD8+ T cells correlating with tumor size and primarily producing IFN-γ. This study explored the distribution and functionality of CD11c+ T cells within the tumor microenvironment (TME) by immunofluorescence microscopy, immune infiltration analysis, and antitumor effect of MGpTrp2 vaccine delivered by more clinically relevant needle-free jet injection (NFJI) as an alternative to EP. It suggests that CD11c acts as a positive prognostic marker that reflects immunotherapy-driven antitumor CD8+T cell responses and infiltration into the TME. Furthermore, it indicates that NFJI delivery of MGpTrp2 vaccine is non-inferior to EP in terms of tumor control and immunogenicity. In summary, the current study provides additional prognostic information for response to cancer immunotherapy and provides evidence that clinically-relevant NFJI vaccine delivery system should be studied further
Environmental Justice and US Cancer Disparities: Investigating the Role of Exposure to Contaminant Metals
No full textDisparities in cancer mortality by race/ethnicity persist in the United States (US) even after accounting for cancer risk factors. Exposure to carcinogenic environmental contaminants may differ by racial/ethnic populations. The role of environmental exposures to cancer disparities has not been fully characterized. The objective of this dissertation was to investigate how race/ethnicity is operationalized in US-based environmental epidemiology studies of cancer and to examine the role of differences in exposure to contaminant metals, measured by arsenic, cadmium, and lead concentrations, to racial/ethnic disparities in cancer mortality.
In a systematic review of the literature, we identified epidemiologic studies on environmental exposures and cancer that included non-White racial/ethnic groups and summarized approaches to operationalizing race/ethnicity. Most studies examined race/ethnicity only as a confounding variable. Remaining studies stratified by race/ethnicity, with many finding stronger effects among racial/ethnic minority groups. Only one study considered race/ethnicity as a main exposure with environmental exposures as mediators in associations with cancer endpoints.
Among 26,715 adults in the National Health and Nutrition Examination Survey (NHANES) 2003-2018, we examined cross-sectional associations between race/ethnicity, socioeconomic status, and acculturation, and intersections of these factors, with arsenic, cadmium, and lead concentrations. Metal concentrations were higher among minoritized racial/ethnic groups and those with less education and less acculturation. Associations were more strongly associated with race/ethnicity than other factors.
Among 20,241 White, Black, and Hispanic adults without a self-reported history of cancer in NHANES 2003-2018 who were followed through 2019, we examined longitudinal associations between arsenic, cadmium, and lead concentrations and cancer mortality. We then estimated the contribution of differences in metal exposure to racial/ethnic differences in cancer mortality. In the overall study population, cadmium was significantly associated with cancer mortality. However, lead and arsenic were associated with cancer mortality among Black and female participants, respectively. In mediation analyses, contaminant metal concentrations did not mediate racial/ethnic differences in cancer mortality.
This dissertation provides novel information on sociodemographic differences in metal exposure and the role of these exposures to US racial/ethnic cancer disparities. Additional prospective studies including diverse populations are needed to understand the burden of disproportionate exposure to environmental contaminants on racial/ethnic cancer disparities
Tin grafting on Self-Pillared Pentasil zeolite
Get PDFAs a material uniquely structured with porous frameworks, zeolites are known for their extensive application in industries ranging from agriculture to catalysis. Such porous structure is further explored along with the development of hierarchical zeolites. The multi-level pore structure of hierarchical zeolites offers them enhanced mass transfer property and increased accessible surface area. However, they suffer complex approach to prepare material and inability over shape and regularity in synthesis. Self-pillared pentasil (SPP) zeolite, which features with properties of hierarchical zeolites, is advantage for its simplicity and economy over synthesis, and strength on morphology. Besides, the ingenious ‘house-of-cards’ porous structure of SPP provides increased specific area and excellent transport performance, making it an ideal as support of catalysts.
In this thesis, attempting to broaden the application of SPP, SPP was modified to the catalyst containing alumina(Al) or tin(Sn) via grafting technique or in-situ synthesis. A modified gas chromatography, termed reactor GC, with automation and consistency in reaction condition, was applied for catalytic test and catalysts screening. By the results of reactor GC, combined with characterization technique, the Sn/SPP materials prepared by grafting Sn on SPP zeolites was found remarkable catalytic activity toward MPV reaction when compared with in-situ synthesized Sn-SPP and Al/SPP materials synthesized by grafting Al on SPP zeolites
Modeling healthy endometrial tissues using multi-compartment assembloids
No full textThe endometrium comprises an interlinked network of epithelial glands surrounded by a dense packing of collagen-rich stroma. The endometrium undergoes remodeling in response to hormone changes and environmental factors, making it vulnerable to various pathologies like endometriosis and endometrial cancer. These disorders significantly affect women’s health and lack effective treatments due to poor understanding of the endometrium’s physiology. Conventional organoid models fail to recapitulate the endometrial tissue anatomy. This study introduces a novel 3D multi-compartment assembloid model designed to replicate the human endometrial microanatomy for improved in vitro studies.
This engineered endometrial model features compartmentalized endometrial epithelial cells in a Matrigel core and stromal cells in a collagen corona, enabling realistic mimicking of cell-cell and cell-ECM interactions of endometrial tissues. The assembloid model demonstrates its capability to support epithelial proliferation and structural formation, with independent yet interrelated functional responses between the epithelial and stromal compartments, indicating its potential in studying the underlying mechanisms of endometrial diseases. Further investigation using quantifiable metrics may help to thoroughly validate and refine this model. This multi-compartment endometrial assembloid model offers a significant improvement over the conventional organoid models, offering a platform for a deeper exploration of endometrial diseases and the development of more efficient treatment methods
POSTTRAUMATIC GROWTH IN CHINESE BURN PATIENTS AND FAMILY CAREGIVERS
No full textStatement of Problem: Burns present dual challenges of physical recovery and psychological adaptation for both patients and their family caregivers. This study investigates posttraumatic growth (PTG) among Chinese adult burn patients and caregivers, aiming to uncover the prevalence, disparities, and determinants of PTG within burn-affected families.
Methods: Across three manuscripts, this research employs cross-sectional surveys from two burn units in China (2016-2017) and extends to a sample of 234 patient-caregiver dyads from 10 hospitals (2023). Utilizing a battery of measures including Posttraumatic Growth Inventory (PTGI), Depression, Anxiety, and Stress Scales-21 (DASS-21), Posttraumatic Stress Disorder Checklist (PCL-5), and Multidimensional Scale of Perceived Social Support (MSPSS), the studies investigate PTG's and its association with sociodemographic and injury characteristics and psychological symptoms.
Results: Findings across manuscripts reveal significant proportions of burn patients and family caregivers exhibit moderate to high levels of PTG. Notably, social support and higher levels of depression are significant predictors of PTG in patients, while PTG in caregivers is influenced by gender, education level, social support, and anxiety. The work highlights shared yet distinct growth pathways within dyads, with PTG variation influenced by social support, injury severity, and individual stressors.
Conclusion: This study represents a first time exploration into PTG within burn-affected families, unveiling the presence and influence among patients, family caregivers, and the family unit as a whole. While social support emerges as a consistent predictor of PTG across single populations or dyads, patients and caregivers exhibit noteworthy differences in other growth-related factors. The results advocate for tailored interventions addressing commonalities and disparities in PTG experiences
Semiparametric Change Point Model for Survival Outcomes in the Presence of a U-Shaped Risk
Get PDFIn cardiovascular disease studies, there often exist U-shaped risk curves where the risk of adverse events first decreases and then increases as the biomarker values increase. Understanding the shape of the U-shaped curve and especially the location of its lowest point can help researchers identify high-risk subgroups. However, few current regression methods that model the U-shaped relationship can be applied to survival outcomes. Survival methods that predict the risk of adverse events could not be used to estimate the number and location of change points and generally lack computational efficiency. In this paper, we propose a semi-parametric model to leverage the U-shaped risk curve for risk prediction. To estimate the model, we propose a rank-based estimator, which is shown to be consistent, asymptotically normal, computationally feasible, and well-behaved in finite samples through simulation studies. We also apply the proposed methods to clinical trial data to predict the U-shaped risk curve between cardiovascular outcomes and BMI and estimate the lowest point
EXPLORING THE IMPACT OF MEASUREMENT CHANGES ON CAUSAL INFERENCE IN LONGITUDINAL DATA: A DESCRIPTIVE STUDY
Get PDFThis thesis explores the methodological challenges posed by the transition from the Uniform Crime Reporting (UCR) system to the National Incident-Based Reporting System (NIBRS) in crime data reporting. Initiated by the FBI in the 1920s, UCR has been a standardized crime data collection framework, which NIBRS aims to enhance by providing detailed incident-based statistics since the 1980s. Despite a federal mandate for a complete transition to NIBRS by 2021, adoption rates vary, affecting longitudinal crime rate studies that require decisions on data utilization.
This study conducts a descriptive analysis of crime rates reported under both UCR and NIBRS from 2001 to 2022 in Virginia, Arkansas, Colorado, and Iowa, focusing on major crime indicators such as murder, rape, and burglary. Findings reveal statistically significant discrepancies in reporting between the two systems across most crime types and states, suggesting complexities in transitioning to a new reporting system that could impact statistical analyses of crime trends.
Building on these observations, Part II of the thesis employs a Difference in Differences (DiD) approach to examine how changes in data collection methodologies influence the bias of DiD estimates. This section includes a focused simulation study to evaluate the impact of measurement changes on the accuracy of causal inferences. The results demonstrate that such changes can significantly alter the accuracy of treatment effect estimations, presenting substantial challenges for causal inference in public policy analysis concerning crime rates.
This thesis highlights the necessity for further examination and comparison of crime data from both UCR and NIBRS to identify discrepancies that may influence research outcomes. Addressing these variations is crucial for developing statistical methods that ensure reliable results in policy-making and evaluation. These insights are vital for policymakers, law enforcement agencies, and researchers, contributing to the discourse on effectively interpreting and utilizing evolving crime data methodologies
DEVELOPMENTS OF RELATIVISTIC ELECTRONIC STRUCTURE METHODS FOR MOLECULAR APPLICATIONS
Get PDFThis dissertation focuses on the development of relativistic electronic structure methods and their application to molecular systems containing heavy elements. I have developed the exact two-component method with atomic-mean-field spin-orbit integrals (the X2CAMF scheme) based on four-component Dirac-Coulomb-Breit Hamiltonian. The X2CAMF scheme offers a computationally efficient and accurate description of relativistic effects. The variational treatment of spin-orbit couplings at the orbital level, in the spinor representation, provides unique capabilities for capturing the complicated electronic structure of heavy-element-containing open-shell molecules within a single-reference computational framework, enabling highly accurate predictions of chemical properties using coupled-cluster (CC) theories. Perturbative treatments of spin-orbit and vibronic couplings have been combined to describe the spin-vibronic structures in small molecules relevant to laser cooling. Excellent agreement with experimentally measured vibrational branching ratios has been achieved. The calculations, at the same time, offer valuable insights into the intensity-borrowing mechanism in vibronic transitions. Additionally, Cholesky decomposition (CD)-based implementations of relativistic CC and equation-of-motion CC methods, along with corresponding analytical energy derivatives, have been developed for large molecular systems with 1000 correlating molecular spinors, greatly extending the applicability of relativistic CC
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