The epidemiology of prostate cancer among multiethnic men

The research goal was to document differences in the epidemiology of prostate cancer among multicultural men [non-Hispanic White (NHW), Hispanic (H), non-Hispanic Black (NHB)], and Black subgroups, particularly among NHB subgroups [US-born (USB) and Caribbean-born (CBB)]. Study findings will be useful in supporting further research into Black subgroups. Aim 1 explored changes over time in reported prostate cancer prevalence, by race/ethnicity and by birthplace (within the Black subgroups). Aim 2 investigated relationships between observed and latent variables. The analytical approaches included confirmatory factor analysis (CFA for measurement models) and structural equation modeling (SEM for regression models). National Center for Health Statistics, National Health Interview Survey (NHIS) data from 1999–2008 were used. The study sample included men aged 18 and older, grouped by race/ethnicity. Among the CBB group, survey respondents were limited to the English-speaking Caribbean. Prostate cancer prevalence, by race showed a higher trend among NHB men than NHW men overall, however differences over time were not significant. CBB men reported a higher proportion of prostate cancer among cancers diagnosed than USB men overall. Due to small sample sizes, stable prostate cancer prevalence trends could not be assessed over time nor could trends in the receipt of a PSA exam among NHB men when stratified by birthplace. USB and CBB men differ significantly in their screening behavior. The effect of SES on PSA screening adjusted for risk factors was statistically significant while latent variable lifestyle was not. Among risk factors, family history of cancer exhibited a consistent positive effect on PSA screening for both USB and CBB men. Among the CBB men, the number of years lived in the US did not significantly affect PSA screening behavior. When NHB men are stratified by birthplace, CBB men had a higher overall prevalence of prostate cancer diagnoses than USB men although not statistically significant. USB men were 2 to 3 times more likely to have had a PSA exam compared to CBB men, but among CBB men birthplace did not make a significant difference in screening behavior. Latent variable SES, but not lifestyle, significantly affected the likelihood of a PSA exam.

Evaluating heavy episodic drinking effects on educational attainment

Adolescence and emerging adulthood are transition points that offer both opportunities and constraints on individual development. The purpose of this study is threefold: First, to examine two models (i.e., young adolescents in grades 7 and 8 and older adolescents in grade 12) of heavy episodic drinking and examine how heavy episodic drinking affects subsequent educational attainment. By utilizing two different developmental transitions, i.e., middle school to high school and high school to college, it may be possible to better understand the temporal effects of alcohol use and subsequent educational attainment. The second purpose of this study is to examine how alcohol use at Time 1 may lead to the problems in the adolescent's immediate context due to alcohol (i.e., problems with parents, peers, romantic relationships, problems at school) and to examine if these problems affect educational attainment over and above alcohol use alone. The third purpose of this study is to examine the potential gender differences in these models. The study uses data from the National Longitudinal Study of Adolescent Health, which is a large scale, nationally representative school based sample of 20,745 adolescents who were interviewed in grades 7 to 12. Two longitudinal mediational models were evaluated utilizing structural equation modeling. Binge drinking and number of days drunk were used as indicators for a latent variable of heavy episodic drinking (i.e., LHED). In the 7th and 8th grade model, direct effects of LHED were found to predict educational attainment at grade 12. Additionally, in the 7th and 8th grade sample, a mediated relationship was found whereby educational attainment was predicted by problems with parents. Problems with parents were predicted by number of days drunk in the past year. In the 12th grade sample, there were no direct effects or indirect effects of alcohol on educational attainment. This study highlights the need for using a longitudinal framework when examining heavy episodic drinking's effects on educational attainment. ^

The longitudinal influence of physical activity on adolescent alcohol use

The purpose of this research was to explore the influence of physical activity on depressive symptomatology and adolescent alcohol use during an underexplored transition from middle school to high school. The study initiative is supported by the fact that research has shown a unique and simultaneous decrease in physical activity (CDC, 2010), increase in depressive symptomatology (SAMHSA, 2010) and increase in alcohol use (USDHHS, 2011) during middle adolescence. A risk and resilience framework was used in efforts to conceptualize how these variables may be inter-related. Data from waves I and II of the National Longitudinal Study of Adolescent Health (Add Health, Bearman et al., 1997; Udry, 1997) was used (N = 2,054; aged 13–15 years). The sample was ethnically and racially diverse (58.2% White, 24% African American, 11.7% Hispanic, and 6.1% other). Structural equation models were developed to test the potential influence physical activity has on adolescent alcohol use (e.g., frequency of alcohol use and binge alcohol use) and whether any of the relationship was mediated by depressive symptomatology or varied as a function of gender. Results demonstrated that there was a significant influence of structured physical activity (e.g., sports) on adolescent alcohol use. However, contrary to the proposed hypothesis, engaging in structured physical activity appeared to contribute to greater binge drinking among adolescents. Instead of demonstrating a protective feature, the findings suggest that engaging in structured physical activity places adolescents at risk for binge drinking. Furthermore, no significant relationships, positive or negative, were found for the influence of physical activity (structured and unstructured) on frequency of alcohol use. The findings regarding mediation revealed binge drinking as a mediator between physical activity (structured) and depressive symptomatology. These findings provide support for research, practice, and policy initiatives focused on developing a more comprehensive understanding of alcohol use drinking behaviors, physical activity involvement, and depressive symptomatology among adolescents, which this study demonstrates are all associated with one another. Results represent an initial step toward evaluating these relationships at a much younger age.

Treatment moderation and secondary outcomes: Results from a randomized clinical trial

The present study pursued two objectives in the context of a randomized clinical trial of cognitive-behavioral therapy with parent (CBT/P) and group (GCBT) involvement. The first objective was to examine the variability in treatment outcome. There were three specific aims within the first objective, to evaluate: (1) youth characteristics (age, depressive, and externalizing disorders) as moderators of treatment outcome; (2) the differential outcome of the treatment approaches as a function of youth characteristics; and (3) the relative efficacy of the treatment approaches at each level of the moderators. ^ The second objective was to evaluate the efficacy of anxiety treatments along secondary depressive symptoms and externalizing behaviors. There were five specific aims within the second objective, to evaluate: (1) whether anxiety treatment yields reductions in secondary problems, (2) the efficacy of anxiety treatments in reducing secondary problems as a function of approach and youth characteristics, (3) whether reductions in anxiety symptoms significantly mediate changes in secondary problems, (4) the directionality of change in the hypothesized mediated relations, and (5) whether the hypothesized mediated relations are moderated by treatment approach and youth characteristics. The specific aims were pursued using data collected from 183 youth and their mothers. Research questions were tested using multiple regressions and structural equation modeling. ^ Age, depressive, and externalizing disorders were significant moderators. CBT/P relative to GCBT lowered anxiety more for younger than older youth. GCBT relative to CBT/P lowered anxiety more for older than younger youth. GCBT relative to CBT/P lowered anxiety more for depressed youth than non-depressed youth. GCBT relative to CBT/P lowered anxiety less for externalizing youth than non-externalizing youth. Treatment reduced depressive symptoms and externalizing problem behaviors. Reductions in anxiety mediated changes in depressive symptoms and externalizing problem behaviors. Reversed directionality was found in the relation between social anxiety and depressive symptoms. In CBT/P the direction of change was from depressive to social anxiety. The opposite was true in GCBT. Reductions in social anxiety mediated posttreatment changes in depressive symptoms in GCBT but not CBT/P. The reverse was true at follow-up. Reductions in social anxiety mediated changes in depressive symptoms for girls but not boys.^

Indirect and direct controls of macroinvertebrates and small fish by abiotic factors and trophic interactions in the Florida Everglades

1. The roles of nutrients, disturbance and predation in regulating consumer densities have long been of interest, but their indirect effects have rarely been quantified in wetland ecosystems. The Florida Everglades contains gradients of hydrological disturbance (marsh drying) and nutrient enrichment (phosphorus), often correlated with densities of macroinvertebrate infauna (macroinvertebrates inhabiting periphyton), small fish and larger invertebrates, such as snails, grass shrimp, insects and crayfish. However, most causal relationships have yet to be quantified. 2.  We sampled periphyton (content and community structure) and consumer (small omnivores, carnivores and herbivores, and infaunal macroinvertebrates inhabiting periphyton) density at 28 sites spanning a range of hydrological and nutrient conditions and compared our data to seven a priori structural equation models. 3.  The best model included bottom-up and top-down effects among trophic groups and supported top-down control of infauna by omnivores and predators that cascaded to periphyton biomass. The next best model included bottom-up paths only and allowed direct effects of periphyton on omnivore density. Both models suggested a positive relationship between small herbivores and small omnivores, indicating that predation was unable to limit herbivore numbers. Total effects of time following flooding were negative for all three consumer groups even when both preferred models suggested positive direct effects for some groups. Total effects of nutrient levels (phosphorus) were positive for consumers and generally larger than those of hydrological disturbance and were mediated by changes in periphyton content. 4.  Our findings provide quantitative support for indirect effects of nutrient enrichment on consumers, and the importance of both algal community structure and periphyton biomass to Everglades food webs. Evidence for top-down control of infauna by omnivores was noted, though without substantially greater support than a competing bottom-up-only model.

Evaluating the effects of initial participation in the group therapy process

Although the effectiveness of group therapy has been highlighted, the underlying mechanisms involved in the group process have been under studied. The purpose of this study is twofold. First, the current study utilized an outcome mediation model to examine whether initial level of participation in the intervention (Control/No intervention, non-participatory, participatory) predicted change in Identity Conflict Resolution (IDCR), Personal Expressiveness (PE) and Informational Identity Style (INFO) at posttest, and Internalizing (INT) and Externalizing (EXT) behaviors at post and follow-up assessment. Secondly, the current study examined whether relationships between variables varied as a result of group differences in initial participation. The study utilized an archival sample of 234 high school students, ages 14 to 18, who participated in the Changing Lives Program of the Youth Development Project (YDP) since 2003. Structural equation modeling (SEM) was used to examine differences in direct effects as a result of initial participation on an outcome meditational model. To further analyze this model, SEM was utilized to conduct a multi-group solution to examine whether group differences based on level of initial participation in the variables^

The impact of friends on newly immigrant children's emotional and behavioral adjustment

Immigration disrupts an individual's support network; however, the stresses of the immigration process increase the need for social support. The presence of social support becomes essential for immigrant children and adolescents to cope with these important transitional circumstances. Friends are both sources of social support and models for behavior. Furthermore, friendship networks are known to have a significant influence on youths' functioning. Literature suggests that peer relations become more important in adolescence and friend support is related to child and adolescent well-being. Thus, friend relationships may be particularly important for immigrant youths who experience disruption in their friendship networks during the process of migration to another country. In addition to friendship networks and support, friend characteristics also need to be taken into consideration as important factors for immigrant youth adjustment. My study involved analyses of the effects of friend support and friend problem behaviors on emotional and behavioral functioning for elementary, middle, and high school age newly immigrant children and adolescents. ^ Immigrant children and adolescents (N = 503) were interviewed at schools by interviewers fluent in participants' languages. Structural Equation Modeling (SEM) analyses revealed that friend support and friend problem behaviors were related to children's self-esteem and externalizing behaviors. In addition, friend problem behavior alone predicted children's psychological symptoms and depression scores. Furthermore, age/grade was found to be a moderator for the relation between friend problem behavior and immigrant youth behavioral adjustment such that compared to elementary and high school cohorts, middle school youths showed more externalizing behaviors when they had friends performing problem behaviors. ^ Results supported the idea that both friend support and friend behavior are related to newly immigrant youths' emotional and behavioral adjustment. This study informs further research and interventions concerning the development of programs to facilitate immigrant youths' adjustment by revealing friendship factors related to their adaptation.^

Cognitive competence and life course change in multi-problem adolescents

The dissertation reports on two studies. The purpose of Study I was to develop and evaluate a measure of cognitive competence (the Critical Problem Solving Skills Scale – Qualitative Extension) using Relational Data Analysis (RDA) with a multi-ethnic, adolescent sample. My study builds on previous work that has been conducted to provide evidence for the reliability and validity of the RDA framework in evaluating youth development programs (Kurtines et al., 2008). Inter-coder percent agreement among the TOC and TCC coders for each of the category levels was moderate to high, with a range of .76 to .94. The Fleiss' kappa across all category levels was from substantial agreement to almost perfect agreement, with a range of .72 to .91. The correlation between the TOC and the TCC demonstrated medium to high correlation, with a range of r(40)=.68, p<.001 to r(40)=.79, p<.001. Study II reports an investigation of a positive youth development program using an Outcome Mediation Cascade (OMC) evaluation model, an integrated model for evaluating the empirical intersection between intervention and developmental processes. The Changing Lives Program (CLP) is a community supported positive youth development intervention implemented in a practice setting as a selective/indicated program for multi-ethnic, multi-problem at risk youth in urban alternative high schools in the Miami Dade County Public Schools (M-DCPS). The 259 participants for this study were drawn from the CLP's archival data file. The study used a structural equation modeling approach to construct and evaluate the hypothesized model. Findings indicated that the hypothesized model fit the data (χ2 (7) = 5.651, p = .83; RMSEA = .00; CFI = 1.00; WRMR = .319). My study built on previous research using the OMC evaluation model (Eichas, 2010), and the findings are consistent with the hypothesis that in addition to having effects on targeted positive outcomes, PYD interventions are likely to have progressive cascading effects on untargeted problem outcomes that operate through effects on positive outcomes.

Temporal changes in immigration stress, adaptation, and the factors contributing to the immigration -adaptation process in newly immigrant parents

The adaptation process to a new land can be an arduous transition for families who migrate from their countries in an attempt to evade negative life conditions. Family-based immigration has been the cornerstone of immigration policy for the U.S. However, there has been a relative lack of attention given in immigration studies to the impact of immigration particularly on parents. Furthermore, little is known about their adjustment to their post-migration circumstances, particularly the initial phase of migration, where the psychological impact of immigration tends to be concentrated. It is even rarer that investigators have addressed longitudinally the dynamic process of parents' adaptation to a new ecology, which can shed a great deal of light on its mechanisms. In this dissertation, changes over time in levels of stress, adjustment (affect balance and life satisfaction), and the factors (social support, economic hardship, and discrimination) contributing to stress and adjustment were examined in newly immigrant parents from Argentina, Colombia, Cuba, Haiti, and the West Indies. Moderating effects of gender and country-of-origin were examined as well. This study also aimed to investigate to what extent the contributing factors impacted stress and adjustment, not only concurrently, but also over the first three years of post-migration. Analysis of variance results showed that both affect balance and social support increased whereas life satisfaction decreased over time. There was no significant change in stress, however. Both gender and group effects were also observed. Mothers experienced higher stress whereas fathers experienced higher discrimination. Among groups, Haitians appeared at the greatest risk in terms of stress, discrimination, and economic hardship. A structural equation modeling analysis showed that the relative importance of contributing factors changed over time in the process of immigrants' adaptation. Yet, social support emerged as a powerful protective factor in that its effects carried over time, and discrimination was a primary mediator through which other predictors were related to stress and adjustment. These findings shed light on the "hows and whys" of the immigration-adaptation process, by demonstrating the significance of specific conditions of life change to psychological outcomes as newly immigrant parents adapt to their post-migration ecology.

A model of self -transformative identity development in troubled adolescent youth

Within the Stage II program evaluation of the Miami Youth Development Project's (YDP) Changing Lives Program (CLP), this study evaluated CLP intervention effectiveness in promoting positive change in emotion-focused identity exploration (i.e. feelings of personal expressiveness; PE) and a "negative" symptom of identity development (i.e. identity distress; ID) as a first step toward the investigation of a self-transformative model of identity development in adolescent youth. Using structural equation modeling techniques, this study found that participation in the CLP is associated with positive changes in PE (path = .841, p < .002), but not changes in ID. Increase in ID scores was found to be associated with increases in PE (path = .229, p < .002), as well. Intervention effects were not moderated by age/stage, gender, or ethnicity, though differences were found in the degree to which participating subgroups (African-American/Hispanic, male/female, 14-16 years old/17-19 years old) experience change in PE and ID. Findings also suggest that moderate levels of ID may not be deleterious to identity exploration and may be associated with active exploration. ^

Investigating group processes in a positive youth development program for multi -problem youth

This study investigated group processes as potential mediators or moderators of positive development outcome and negative reduction intervention response by evaluating the utility of a group measure modified from a widely known measure of group impact found in the group therapy research literature. Four group processes were of primary interest, (1) Group Impact; (2) Facilitator Impact; (3) Skills Impact; and (4) Exploration Impact as assessed by the Session Evaluation Form (SEF). Outcome measures included the Personally Expressive Activities Questionnaire (PEAQ), Erikson Psycho-Social Index (EPSI) and the Zill Behavior Items, Behavior Problem Index (ZBI (BPI)). The sample consisted of 121 multi-ethnic participants drawn from four alternative high schools from the Miami-Dade County Public School system. Utilizing a Latent Growth Curve Modeling approach with Structural Equation Modeling (SEM) statistics, preliminary analyses were conducted to evaluate the psychometric properties of the SEF and its role in the mediation or moderation of intervention outcome. Preliminary results revealed evidence of a single higher order factor representing a "General" global reaction, which was hypothesized to be a "Positive Group Climate" construct to the program as opposed to the four distinct group processes that were initially hypothesized to affect outcomes. The results of the evaluation of the mediation or moderation role of intervention outcome of the single "General" global latent factor ("Positive Group Climate" construct) did not significantly predict treatment response on any of the outcome variables. Nevertheless, the evidence of an underlying "General" global latent factor ("Positive Group Climate" construct) has important future directions for research on positive youth development programs as well as in group therapy research.

Influence of religious coping on the substance use and HIV risk behaviors of recent Latino immigrants

This study examines the influence of acculturative stress on substance use and HIV risk behaviors among recent Latino immigrants. The central hypothesis of the study is that specific religious coping mechanisms influence the relationship that acculturative stress has on the substance use and HIV-risk behaviors of recent Latino immigrants. Within the Latino culture religiosity is a pervasive force, guiding attitudes, behaviors, and even social interactions. When controlling for education and socioeconomic status, Latinos have been found to use religious coping mechanisms more frequently than their Non-Latino White counterparts. In addition, less acculturated Latinos use religious coping strategies more frequently than those with higher levels of acculturation. Given its prominent role in Latino culture, it appears probable that this mechanism may prove to be influential during difficult life transitions, such as those experienced during the immigration process. This study examines the moderating influence of specific religious coping mechanisms on the relationship between acculturative stress and substance use/HIV risk behaviors of recent Latino immigrants. Analyses for the present study were conducted with wave 2 data from an ongoing longitudinal study investigating associations between pre-immigration factors and health behavior trajectories of recent Latino immigrants. Structural equation and zero-inflated Poisson modeling were implemented to test the specified models and examine the nature of the relationship among the variables. Moderating effects were found for negative religious coping. Higher levels of negative religious coping strengthened an inverse relationship between acculturative stress and substance use. Results also indicated direct relationships between religious coping mechanisms and substance use. External and positive religious coping were inversely related to substance use. Negative religious coping was positively related to substance use. This study aims to contribute knowledge of how religious coping influence's the adaptation process of recent Latino immigrants. Expanding scientific understanding as to the function and effect of these coping mechanisms could lead to enhanced culturally relevant approaches in service delivery among Latino populations. Furthermore this knowledge could inform research about specific cognitions and behaviors that need to be targeted in prevention and treatment programs with this population.

Regional diversification and performance: Conceptualization and competing strategic objectives

This dissertation comprised of three essays provides justification for the need to pursue research on multinationality and performance with a more fine-grained approach. Essay one is a conceptual response to an article written by Jean-Francois Hennart in 2011 which questions the need and approach toward future research in this domain. I argue that internalization theory does not render multinationality and performance research meaningless and identify key areas where methodological enhancements can be made to strengthen our research findings with regard to Hennart's call for more content validity. Essay two responds to the need for more-fine grained research on the consequences of multinationality by introducing non-traditional measures of performance such as social and environmental performance and adopting a more theoretically relevant construct of regionalization to capture international diversification levels of the firm. Using data from the world's largest 600 firms (based on sales) derived from Bloomberg and the Directory of Corporate Affiliates; I employ general estimating equation analysis to account for the auto-correlated nature of the panel data alongside multivariate regression techniques. Results indicate that regionalization has a positive relationship with economic performance while it has a negative relationship with environmental and social performance outcomes, often referred to as the "Triple Bottom-Line" performance. Essay three builds upon the work in the previous essays by linking the aforementioned performance variables and sample to corporate reputation which has been shown to be a beneficial strategic asset. Using Structural Equation Modeling I explore economic, environmental and social signals as mediators on relationship between regionalization and firm reputation. Results indicate that these variables partially mediate a positive relationship between regionalization and firm reputation. While regionalization positively affects the reputation building signal of economic performance, it aids in reputation building by reducing environmental and social disclosure effects which interestingly impact reputation negatively. In conclusion, the dissertation submits opportunities for future research and contributes to research by demonstrating that regionalization affects performance, but the effect varies in accordance with the performance criterion and context. In some cases, regional diversification may produce competing or conflicting outcomes among the potential strategic objectives of the firm.

The influence of neurocognitive impairment, alcohol and other drug (AOD) use, and psychosocial factors on antiretroviral treatment adherence, service utilization and viral load among HIV-seropositive adults

Among people living with HIV (PLWH), adherence to antiretroviral therapy (ART) can be affected by problems of neurocognitive (NC) impairment, stress, alcohol and other drug (AOD) abuse, and other barriers. The aims of this research were to: (1) examine factors associated with NC impairment, (2) explore relationships between psychosocial variables with ART adherence and viral load (VL), and (3) evaluate the efficacy of an evidence-based intervention in improving ART adherence, increasing service utilization, and decreasing VL. The first study (n=370) was cross sectional and used structural equation modeling to test whether AOD use, years living with HIV, and time from HIV diagnosis to seeking care were associated with poorer NC functioning. The second study (n=246) used similar methods to test the hypothesis that stress, barriers to adherence, NC impairment, poor social support, and AOD use were related to lower VL mediated by ART adherence. The third study (n=243) evaluated an evidence-based, eight-session program to improve ART adherence, reduce VL, and increase service utilization in a randomized controlled trial. Study participants were PLWH living in South Florida, 18 to 60 years old, with a history of alcohol abuse enrolled from January 2009 through November 2012. Secondary analysis of available data showed: (1) scores on interference with executive functioning increased by 0.32 for each day of marijuana use and 1.18 for each year living with HIV, but no association was found between alcohol use and NC functioning; (2) each barrier to adherence was associated with a 10% decrease in adherence to ART and a 0.42 unit increase in VL (log10) and the relationship between barriers and VL was partially mediated by ART adherence; (3) participants in the evidence-based program were more likely than the comparison group to report an undetectable VL (OR=2.25, p<0.01) at 6 months, but not 3 months, post-intervention. Psychosocial factors affect VL, but ART adherence is essential in achieving an undetectable VL in PLWH.

A Suite of Prey Traits Determine Predator and Nutrient Enrichment Effects in a Tri-Trophic Food Chain

Predation, predation risk, and resource quality affect suites of prey traits that collectively impact individual fitness, population dynamics, and community structure. However, studies of multi-trophic level effects generally focus on a single prey trait, failing to capture trade-offs among suites of covarying traits that govern population responses and emergent community patterns. We used structural equation models (SEM) to summarize the non-lethal and lethal effects of crayfish, Procambarus fallax, and phosphorus (P) addition, which affected prey food quality (periphyton), on the interactive effects of behavioral, morphological, developmental, and reproductive traits of snails, Planorbella duryi. Univariate and multivariate analyses suggested trade-offs between production (growth, reproduction) and defense (foraging behavior, shell shape) traits of snails in response to non-lethal crayfish and P addition, but few lethal effects. SEM revealed that non-lethal crayfish effects indirectly limited per capita offspring standing stock by increasing refuge use, slowing individual growth, and inducing snails to produce thicker, compressed shells. The negative effects of non-lethal crayfish on snails were strongest with P addition; snails increased allocation to shell defense rather than growth or reproduction. However, compared to ambient conditions, P addition with non-lethal crayfish still yielded greater per capita offspring standing stock by speeding individual snail growth enabling them to produce more offspring that also grew faster. Increased refuge use in response to non-lethal crayfish led to a non-lethal trophic cascade that altered the spatial distribution of periphyton. Independent of crayfish effects, snails stimulated periphyton growth through nutrient regeneration. These findings illustrate the importance of studying suites of traits that reveal costs associated with inducing different traits and how expressing those traits impacts population and community level processes.