This thesis was to determine the prevalence and distribution of paratuberculosis in the Ontario dairy sheep and dairy goat industries, identify potential risk factors for herds which tested positive, evaluate the accuracy of seven commercially available individual and two bulk tank diagnostic tests in these two populations, and determine the circulating strains of Mycobacterium avium ssp. paratuberculosis in faecal isolates obtained. A cross-sectional study was conducted between October 2010 and August 2011 in 29 goat herds and 21 sheep flocks located in Ontario. On each farm, 20 lactating animals over the age of two years were randomly selected and faeces, blood, and milk were sampled from each animal, and a bulk milk sample from each herd. A questionnaire inquiring about herd management and biosecurity behaviours was also completed. The seven individual animal tests evaluated were: faecal culture using the BACTEC® MGIT™ 960 liquid culture system, direct faecal PCR (Tetracore®, Rockville, MD) based on the hspX gene, the Prionics® ELISA on serum and milk, the IDEXX® ELISA on serum and milk, and the agar gel immunodiffusion (AGID) test on serum. The test evaluations used both frequentist (faecal culture - reference test) and Latent Class Analysis/Bayesian (LCA/BM) methods (no reference test). In goat herds, faecal culture demonstrated the highest sensitivity (Se), 81.1% (LCA/BM). In sheep, while faecal culture demonstrated the highest Se, 49.5%, there was a small probability it was higher than faecal PCR Se at 42.4%. The bulk tank tests evaluated were the 'Hyper-ELISA' test and real-time PCR test based on IS900 (AntelBio®). While PCR did not demonstrate sufficiently high Se to be used as a herd-level test, the Hyper-ELISA performed well as a herd-level test identifying farms with high prevalence when the cut-off was reduced to 0.05. Overall herd-level apparent prevalence was 79.3% in goat herds and 57.1% in sheep flocks when faecal culture was the reference standard and true herd-level prevalence (LCA/BM) was 83.0% and 66.8% in each population respectively. This high prevalence reveals a need for the implementation of a small ruminant paratuberculosis control program in Ontario, Canada based on testing, improving youngstock management, and strengthening biosecurity practices. / AHSI, OMAF

abstract: Parenting approaches that are firm yet warm (i.e., authoritative parenting) have been found to be robustly beneficial for mainstream White Americans youths, but do not demonstrate similarly consistent effects among Chinese Americans (CA) adolescents. Evidence suggests that CA adolescents interpret and experience parenting differently than their mainstream counterparts given differences in parenting values and child-rearing norms between traditional Chinese and mainstream American cultures. The current study tests the theory that prospective effects of parenting on psychological and academic functioning depends on adolescents' cultural frameworks for interpreting and understanding parenting. CA adolescents with values and expectations of parenting that are more consistent with mainstream American parenting norms were predicted to experience parenting similar to their White American counterparts (i.e., benefiting from a combination of parental strictness and warmth). In contrast, CA adolescents with parenting values and expectations more consistent with traditional Chinese parenting norms were predicted to experience parenting and its effects on academic and psychological outcomes differently than patterns documented in the mainstream literature. This study was conducted with a sample of Chinese American 9th graders (N = 500) from the Multicultural Family Adolescent Study. Latent Class Analysis (LCA), a person-centered approach to modeling CA adolescents' cultural frameworks for interpreting parenting, was employed using a combination of demographic variables (e.g., nativity, language use at home, mother's length of stay in the U.S.) and measures of parenting values and expectations (e.g., parental respect, ideal strictness & laxness). The study then examined whether prospective effects of parenting behaviors (strict control, warmth, and their interaction effect) on adolescent adjustment (internalizing and externalizing symptoms, substance use, and GPA) were moderated by latent class membership. The optimal LCA solution identified five distinct cultural frameworks for understanding parenting. Findings generally supported the idea that effects of parenting on CA adolescent adjustment depend on adolescents' cultural framework for parenting. The classic authoritative parenting effect (high strictness and warmth leads to positive outcomes) was found for the two most acculturated groups of adolescents. However, only one of these groups overtly endorsed mainstream American parenting values. / Dissertation/Thesis / Ph.D. Psychology 2011

Efforts to objectively inform cannabis discourses include research on the epidemiology of cannabis abuse and dependence disorders or, collectively, cannabis use disorder (CUD). For my dissertation I identified classes of individuals based on intraindividual CUD trajectory patterns and contrasted trajectory classes with respect to clinical characteristics of CUD, developmental risk factors, and psychosocial outcomes. Identifying differences between trajectory classes provides evidence for the validity of trajectory-based CUD constructs and informs the development of comprehensive models of CUD epidemiology and trajectory-specific intervention approaches. My dissertation used data from the Oregon Adolescent Depression Project, a prospective epidemiological study of the psychiatric and psychosocial functioning of a representative community-based sample randomly selected from nine high schools across western Oregon. Four waves of data collection occurred between mid-adolescence and early adulthood and included diagnostic interviews and self-report questionnaires. Onset and offset ages of all CUD episodes were recorded. The reference sample included 816 participants who completed all diagnostic interviews. A series of latent class growth models revealed three distinct CUD trajectory classes through age 30: (1) a persistent increasing risk class; (2) a maturing out class, marked by increasing risk through age 20 and then a decreasing risk through early adulthood; and (3) a stable low risk class. Rates of cannabis dependence were similar across the persistent increasing and the maturing out classes. Trajectory classes characterized by a history of CUD were associated with a variety of childhood risk factors and measures of psychosocial functioning during early adulthood. Participants who were male, had externalizing disorders, and had psychotic experiences during early adulthood discriminated between the persistent increasing and the maturing out classes. Future research based on more diverse samples is indicated, as are well-controlled tests of associations between risk factors, trajectory class membership, and psychosocial outcomes. A better understanding of these relationships will inform etiological theories of CUD and the development of effective intervention programs that target problematic cannabis use at specific developmental stages. Designing targeted versus undifferentiated interventions for those at greatest risk for adult psychosocial impairment could be a cost-effective way to mitigate the consequences of CUD.

abstract: The purpose of this study was to examine under which conditions "good" data characteristics can compensate for "poor" characteristics in Latent Class Analysis (LCA), as well as to set forth guidelines regarding the minimum sample size and ideal number and quality of indicators. In particular, we studied to which extent including a larger number of high quality indicators can compensate for a small sample size in LCA. The results suggest that in general, larger sample size, more indicators, higher quality of indicators, and a larger covariate effect correspond to more converged and proper replications, as well as fewer boundary estimates and less parameter bias. Based on the results, it is not recommended to use LCA with sample sizes lower than N = 100, and to use many high quality indicators and at least one strong covariate when using sample sizes less than N = 500. / Dissertation/Thesis / M.A. Psychology 2012

abstract: The victim-offender overlap is a widely accepted empirical fact in criminology. While many methodological strategies have been used to study overlap, prior studies have assumed that it is uniform, taking little consideration into the potential differences within the overlap. The larger body of criminological research on pathways to crime suggests that victim-offenders also have variability in their victimization experiences and offending patterns. Not accounting for variation within the overlap has produced inconsistent findings in terms of establishing theoretical explanations for the victimization and offending relationship. Several general theories of crime have merit in their assumptions about the relationship between victimization and offending. Routine activity/lifestyle theory, low self-control theory, and general strain theory offer insight into the overlap. Variables derived from these three general theories are assessed to test their ability to explain a more complex conceptualization of the victim-offender overlap. Using data on 3,341 individuals drawn from four waves of the publically available National Longitudinal Study of Adolescent to Adult Health (Add Health), a latent class analysis establishes unique victim-offender overlap taxonomies. A multinomial logistic regression is conducted to test how well theoretically derived variables from three general theories (e.g., routine activity theory, low self-control theory, and general strain theory) predict membership in the unique victim-offender overlap taxonomies. Additional multinomial logistic regressions are run using a split sample analyses to test the invariance of the findings across different social groupings (e.g., gender and race/ethnicity). Comparing the more complex operationalization of the victim-offender overlap with the baseline regression models shows notable differences. For example, depression significantly predicts membership in the general victim-offender overlap group, but when taking into consideration variation within the overlap, depression does not consistently predict membership in all taxonomies. Similar results are found for routine activity/lifestyle theory and low self-control theory. Tests of invariance across gender and race/ethnicity highlight the need to consider how theoretical explanations of the victim-offender overlap differ based on social groupings. Males and females have unique risks and needs and these should be reflected in how routines and negative emotions are measured. The findings underscore the need to consider overlap when studying the relationship between victims and offenders. Implications for theory, future research, and policy are also discussed. / Dissertation/Thesis / Doctoral Dissertation Criminology and Criminal Justice 2018

abstract: This dissertation examined Mexican American individuals' romantic relationships within two distinct developmental periods, adolescence and adulthood. Study 1 used latent class analysis to explore whether 12th grade Mexican Americans' (N = 218) romantic relationship characteristics, cultural values, and gender created unique romantic relationship profiles. Results suggested a three-class solution: higher quality, satisfactory quality, and lower quality romantic relationships. Subsequently, associations between profiles and adolescents' adjustment variables were examined via regression analyses. Adolescents with higher and satisfactory quality romantic relationships reported greater future family expectations, higher self-esteem, and fewer externalizing symptoms than adolescents with lower quality romantic relationships. Similarly, adolescents with higher quality romantic relationships reported greater academic self-efficacy and fewer sexual partners than adolescents with lower quality romantic relationships. Finally, adolescents with higher quality romantic relationships also reported greater future family expectations and higher academic self-efficacy than adolescents with satisfactory quality romantic relationships. To summarize, results suggested that adolescents engaged in three unique types of romantic relationships with higher quality being most optimal for their adjustment. Study 2 used latent growth modeling to examine marital partners' (N = 466) intra- and inter-individual changes of acculturative stress, depressive symptoms, and marital quality. On average across the seven years, husbands' acculturative stress remained steady, but wives' significantly decreased; partners' depressive symptoms remained relatively steady, but their marital quality significantly decreased. Although partners' experiences of acculturative stress were less similar than their experiences of depressive symptoms and marital quality, overall their experiences were interconnected. Significant spillover and crossover effects emerged between partners' initial levels of acculturative stress and depressive symptoms and between depressive symptoms and marital quality. Moreover, changes in husbands' depressive symptoms were negatively associated with changes in their marital quality. Overall, results suggested that partners' experiences were interconnected across time. / Dissertation/Thesis / Ph.D. Family and Human Development 2014

We propose the use of Latent Class Analysis methods to analyze the covariate inclusion patterns across specifications resulting from Bayesian model averaging exercises. Using Dirichlet Process clustering, we are able to identify and describe dependency structures among variables in terms of inclusion in the specifications that compose the model space. We apply the method to two datasets of potential determinants of economic growth. Clustering the posterior covariate inclusion structure of the model space formed by linear regression models reveals interesting patterns of complementarity and substitutability across economic growth determinants.

The Strong Black Woman Schema (SBWS) refers to the collective believes, behaviors, resources and responses Black women are socialized to embody. The SBWS was developed as a positive counterimage to the negative stereotypes of Black women, such as the mammy or the jezebel, and is an important image among Black women. Observations suggest that the SBWS may affect how Black women experience and interpret stress and mental illness. I assert the SBWS may serve as one comprehensive explanation for the mental health outcomes observed for Black women. Qualitative and quantitative studies have identified a set of characteristics (i.e. strength, emotion regulation, caretaking) related to the schema. However, scales developed to measure the schema lack the ability to isolate adequately a unique typology for Black women. I argue that the SBWS is representative of a specific compilation of psychosocial resources (i.e. mastery, self-efficacy, resilience, self-esteem) representative of the cultural response to historical experiences of racism and sexism. I explore how the SBWS influences the reporting of depressive symptoms, depression and anxiety through a secondary data analysis of African American, Caribbean Black and White American women using data from the National Survey of American Life. Through a three part analysis, I answer the following questions: 1) Is a compilation of psychosocial measures an appropriate measure of the Strong Black Woman Schema? 2) What sociodemographic factors influence distinct typologies reflective of at least one uniquely Black form of the Strong Black Woman Schema? And 3) Does the Strong Black Woman Schema influence depressive symptons, depression, and anxiety? Results of this study clarify how socio-cultural aspects of oppression influence the mental health of Black women.

Research over the last few decades has consistently found that fathers are not routinely included in the provision of child welfare services. The current study examined whether ambivalent sexism on the part of child welfare workers was related to their beliefs about involving fathers. Ambivalent sexism theory posits that gender stereotypes include subjectively positive beliefs in addition to hostile beliefs that both serve to perpetuate patriarchal systems. Participants (N = 490) were currently front-line child welfare workers in the United States who completed an online survey assessing ambivalent sexism and beliefs about father involvement in child welfare cases. Ambivalent sexism was assessed using the Ambivalent Sexism Inventory and the Ambivalence Toward Men Inventory. The Dakota Father Friendly Assessment was modified to assess beliefs about father involvement in child welfare. Latent class analysis was used to empirically derive four sexism profiles. Results indicated that participants with profiles suggesting less sexist beliefs had more positive attitudes about father involvement and had a lower preference for working solely with mothers. Sexism profile was not related to participants’ stated father involvement behaviors such as conducting home visits when fathers are present, including fathers in case planning discussions, and recruiting fathers or paternal relatives as placement options. Implications for social work and child welfare practice include developing training that increases knowledge of fathers’ importance and increases workers’ comfort in providing services to men.

Direct marketing problems have been intensively reviewed in the marketing literature recently, such as purchase frequency and time, sales profit, and brand choices. However, modeling the customer response, which is an important issue in direct marketing research, remains a significant challenge. This thesis is an empirical study of predicting customer response to direct marketing and applies a Bayesian approach, including the Bayesian Binary Regression (BBR) and the Hierarchical Bayes (HB). Other classical methods, such as Logistic Regression and Latent Class Analysis (LCA), have been conducted for the purpose of comparison. The results of comparing the performance of all these techniques suggest that the Bayesian methods are more appropriate in predicting direct marketing customer responses. Specifically, when customers are analyzed as a whole group, the Bayesian Binary Regression (BBR) has greater predictive accuracy than Logistic Regression. When we consider customer heterogeneity, the Hierarchical Bayes (HB) models, which use demographic and geographic variables for clustering, do not match the performance of Latent Class Analysis (LCA). Further analyses indicate that when latent variables are used for clustering, the Hierarchical Bayes (HB) approach has the highest predictive accuracy.