Abstract

Introduction: Depression is prevalent among U.S. immigrants, including Korean immigrants. However, little is known about factors that may contribute to their depression. Preliminary evidence suggests that less acculturated individuals are at greater risk for depression but that social support may buffer any negative effects of less acculturation. The aims of this study were to examine the relationship between acculturation and depressive symptoms among Korean immigrants and the moderating role of social support.

Methods: A convenience sample of 132 adult Korean immigrants completed 6 self-report measures: the Center for Epidemiologic Studies Depression Scale, a Korean version of the Acculturation Rating Scale for Mexican Americans-II, the Multi-Dimensional Scale of Perceived Social Support, the Perceived Stress Scale, the MacArthur Scale of Subjective Social Status, and a demographic questionnaire. Hierarchical regression analysis was used to examine the aims, controlling for covariates.

Results: 31% of the sample met the criteria for being depressed. Greater acculturation was associated with more depressive symptoms while greater social support was a significant predictor of fewer symptoms. Social support was more strongly related to less depression among immigrants who were less acculturated than among immigrants who were more acculturated, but this difference was not significant. Perceived stress was the most significant predictor of depression. Older age at immigration and less education were also related to greater depression. Variables in the regression model accounted for 65% of the variance in predicting depression.

Conclusions: Findings indicate a high prevalence of depressive symptoms in this Korean immigrant sample. Results also suggest that acculturation per se may not play a major role in depressive symptoms but rather more specific factors associated with acculturation such as age at immigration and educational levels. These factors should be studied in future research, along with efforts to better understand the causes of stress and impaired social networks in this population. Findings point to a need for regular assessment of depression by health care providers as well as the stress and social support available in a Korean immigrant’s life. Results also suggest that community-based prevention programs to address these problems may be warranted.

We will discuss several questions related to q-hypergeometric series and modular functions. Nahm's conjecture is an attempt to answer the question of when a certain q-hypergeometric series can have modularity. With this conjecture as motivation, we will consider a few closely related algebraic objects such as Bloch groups, Y-systems, T-systems, Q-systems, the dilogarithm function and its variants.

Central obesity measures—such as waist circumference (WC) and waist-to-height ratio (WHtR)—were found to have additional predictive power to body mass index (BMI) in assessing cardiometabolic risk. Few studies have assessed how well central obesity measures compared to general obesity as defined by BMI predict vascular health risks among young children. The objective of this dissertation was to estimate the prevalence of central obesity and to assess their associations with dyslipidemia and hypertension among U.S. children ages 6 to 11 years based on the 2007-2016 National Health and Nutrition Examination Survey (NHANES). In 2015-2016, 15.8% of children overall were centrally obese as defined by WC; 29.8% were centrally obese as defined by WHtR; 17.4% were generally obese as defined by BMI. Hispanic American children had a significantly higher prevalence of central and general obesity than non-Hispanic white and black children, and those children living in a high-income family were less centrally obese as defined by WHtR. The study also observed that the prevalence of central obesity as defined by WC was significantly decreased during 2007-2008 through 2015-2016 (from 21.2% to 15.8%). Data suggested that WHtR is a better predictor for dyslipidemia, whereas BMI is a better predictor for hypertension among obesity indexes among U.S. children ages 6 to 11 years. This dissertation provides a foundation for developing childhood obesity-related public health strategies and considerations for pediatric clinicians in screening multi-ethnic groups of children. A more comprehensive investigation of the effectiveness of interventions to reduce WC related to vascular health outcomes can contribute to our understanding of how central fat mass in childhood affects an individual’s long-term health.

Oral cancer is the�6th�most common cancer�worldwide, and more than 30,000 Americans are diagnosed with oral cancer each year. The 5-year survival rate for this group of cancers has been about 50%, despite advances in surgery, radiation, and chemotherapy. In addition to premature death associated with oral cancer, the severe morbidity from cancer treatment makes oral cancer a major public health concern. Thus, although there has been in depth studies for understanding the molecular pathogenesis of oral cancer, further studies of the understanding of the cancer etiology, development, progress and recurrences are warranted. Recent studies have shown that cancer cells, including oral cancer, contain a small population of cancer stem cells (CSCs or alternatively cancer initiating cells) associated with drug resistance, metastasis and recurrence of the cancer. Therefore, CSCs might be strategically plausible targets for cancer therapies. More recently, many studies indicated that the suppression of Orai1 can diminish malignant phenotypes of cancer cells. Although Orai1 is known as a key calcium channel for store-operated Ca2+�entry, the underlying mechanism by which Orai1 regulates cancer progression remains unknown. Here we demonstrate that Orai1 is increased in a stepwise manner during oral/oropharyngeal carcinogenesis and highly expressed in cancer stem-like cell (CSC)-enriched populations of human oral/oropharyngeal squamous cell carcinoma (OSCC). Ectopic Orai1 expression further induced malignant transformation and self-renewal capacity, ALDH1HIGH cell population, increased. Conversely, inhibition of Orai1 suppressed tumorigenic and CSC phenotype in OSCC, indicating that Orai1could be an important element for tumorigenicity and stemness of OSCC. Mechanistically, Orai1 activates its major downstream effector molecule, NFATc3. Knockdown of NFATc3 in the Orai1-overexpressing oral epithelial cells abrogates the effect of Orai1 on CSC phenotype. Antagonist of NFAT signaling also decreases CSC phenotype, implying the functional importance of Orai1/NFAT axis in OSCC CSC regulation. Moreover, Orai1-induced cytokines in HOK-16B/Orai1 cells were commonly upregulated in CSCs and enhanced important CSC phenotypes, i.e., self-renewal in OSCC. Subset of these CSC-specific cytokines were regulated by NFAT signaling, and partially rescued CSC phenotype in Orai1 inactivated OSCC, which suggests a possible role of cytokines in regulating CSC through Orai1-NFAT signaling. This study identifies Orai1 as a novel molecular determinant for OSCC progression by enhancing cancer stemness, suggesting that inhibition of Orai1-NFAT signaling may offer an effective therapeutic modality against OSCC.