Targeted inactivation of sister of P-glycoprotein gene (spgp) in mice results in nonprogressive but persistent intrahepatic cholestasis

Mutations in the sister of P-glycoprotein (Spgp) or bile salt export pump (BSEP) are associated with Progressive Familial Intrahepatic Cholestasis (PFIC2). Spgp is predominantly expressed in the canalicular membranes of liver. Consistent with in vitro evidence demonstrating the involvement of Spgp in bile salt transport, PFIC2 patients secrete less than 1% of biliary bile salts compared with normal infants. The disease rapidly progresses to hepatic failure requiring liver transplantation before adolescence. In this study, we show that the knockout of spgp gene in mice results in intrahepatic cholestasis, but with significantly less severity than PFIC2 in humans. Some unexpected characteristics are observed. Notably, although the secretion of cholic acid in mutant mice is greatly reduced (6% of wild-type), total bile salt output in mutant mice is about 30% of wild-type. Also, secretion of an unexpectedly large amount of tetra-hydroxylated bile acids (not detected in wild-type) is observed. These results suggest that hydroxylation and an alternative canalicular transport mechanism for bile acids compensate for the absence of Spgp function and protect the mutant mice from severe cholestatic damage. In addition, the spgp−/− mice display a significant increase in the secretion of cholesterol and phospholipids into the bile. This latter observation in spgp−/− mice suggests that intrahepatic, rather than intracanalicular, bile salts are the major driving force for the biliary lipid secretion. The spgp−/− mice thus provide a unique model for gaining new insights into therapeutic intervention for intrahepatic cholestasis and understanding mechanisms associated with lipid homeostasis.

The Impact of Shyness on Loneliness, Social Anxiety, and School Liking in Late Childhood

Author: Charity M. Walker Title: THE IMPACT OF SHYNESS ON LONELINESS, SOCIAL ANXIETY, AND SCHOOL LIKING IN LATE CHILDHOOD Advisor: Maria T. Riva, Ph.D. Degree Date: August 2011 ABSTRACT Shyness is associated with several emotional, social, and academic problems. While there are multiple difficulties that often accompany shyness, there appear to be some factors that can moderate negative effects of shyness. Research has demonstrated that certain parenting factors affect the adjustment of shy children in early childhood, but there is minimal research illuminating the effect of parenting factors in older age groups. The first purpose of this study was to examine relationships between shyness and loneliness, social anxiety, and school liking. The second purpose was to investigate whether the quality of the relationship between a parent and a 10- to 15-year-olds child influences the amount of loneliness or social anxiety a shy child experiences or how the child feels about school. Parent-child dyads served as participants and were recruited from public and private middle schools and church youth groups in Colorado and Indiana. Child participants completed several self-report surveys regarding their relationship with a parent, shyness, loneliness, social anxiety, and their attitude toward school. Parents completed a survey about their relationship with their child and responded to questions related to their perceptions of their child's shyness. Data was analyzed with a series of correlation and regression analyses. Greater degrees of self-reported shyness were found to be associated with higher levels of loneliness and social anxiety and less positive feelings about school. Due to a problem with multicollinearity during data analysis, this study was not able to explore the effect of the parent-child relationship quality on the associations between shyness and adjustment factors. Overall, these findings imply that shyness remains an important issue as children approach adolescence. Further research is needed to continue learning about the potential importance of parent-child interactions in reducing maladjustment for shy children during late childhood.

Psychometric properties of the School Anxiety Inventory-Short Version in Spanish secondary education students

Background: The School Anxiety Inventory (SAI) can be applied in different fields of psychology. However, due to the inventory’s administration time, it may not be useful in certain situations. To address this concern, the present study developed a short version of the SAI (the SAI-SV). Method: This study examined the reliability and validity evidence drawn from the scores of the School Anxiety Inventory-Short Version (SAI-SV) using a sample of 2,367 (47.91% boys) Spanish secondary school students, ranging from 12 to 18 years of age. To analyze the dimensional structure of the SAI-SV, exploratory and confirmatory factor analyses were applied. Internal consistency and test-retest reliability were calculated for SAISV scores. Results: A correlated three-factor structure related to school situations (Anxiety about Aggression, Anxiety about Social Evaluation, and Anxiety about Academic Failure) and a three-factor structure related to the response systems of anxiety (Physiological Anxiety, Cognitive Anxiety, and Behavioral Anxiety) were identified and supported. The internal consistency and test-retest reliability were determined to be appropriate. Conclusions: The reliability and validity evidence based on the internal structure of SAI-SV scores was satisfactory.

The Questionnaire about Interpersonal Difficulties for Adolescents: Reliability and Validity Evidence in Colombian Adolescents

The aim of this study was to analyze reliability and validity evidence of scores on the Colombian version of the Questionnaire about Interpersonal Difficulties for Adolescents (QIDA) in a sample of 1,628 adolescents (65.7% boys), ranging in age from 12 to 18 years. Confirmatory factor analyses replicated the correlated five-factor structure of the QIDA: Assertiveness, Heterosexual Relationships, Public Speaking, Family Relationships, and Close Friendships. Internal consistency for the QIDA and subscales scores was excellent. Girls reported higher level of perceived anxiety in heterosexual relationships, whereas boys showed more anxiety in close friendships and decreased interpersonal anxiety during adolescence. Results support the reliability and validity of the scores on the Colombian version of the QIDA.

Relationship between sociometric types and academic achievement in a sample of compulsory secondary education students

The aim of this study was to analyse the relationship between sociometric types, behavioural categories and academic achievement in a sample of 1,349 compulsory secondary education students (51.7% boys), ranging in age from 12 to 16 years. The students’ sociometric identification was performed by using the Programa Socio and academic performance was measured by school marks provided by teachers in the subjects of Spanish language, mathematics and average academic performance. The results show that sociometric types were significant predictors of academic achievement, as students who were rated positively by their peers (popular, leaders, collaborators and good students) were more likely to have high academic achievement (in mathematics, Spanish language and average academic achievement) than students rated negatively by peers (rejected-aggressive, rejected-shy, neglected and bullies).

School Anxiety Inventory–Short Version: Factorial Invariance and Latent Mean Differences Across Gender and Age in Spanish Adolescents

This study examined the factorial invariance and latent mean differences of the School Anxiety Inventory–Short Version across gender and age groups for 2,367 Spanish students, ranging in age from 12 to 18 years. Configural and measurement invariance were found across gender and age samples for all dimensions of the School Anxiety Inventory–Short Version.

Profiles of emotional intelligence and learning strategies in a sample of Chilean students

In the last few years, one of the lines of research of great interest in the field of emotional intelligence (EI) has been the analysis of the role of emotions in the educational context and, in particular, their influence on learning strategies. The aims of this study are to identify the existence of different EI profiles and to determine possible statistically significant differences in learning strategies between the obtained profiles. The study involved 1253 Chilean school students from 14 to 18 years (M = 15.10, SD = 1.30), who completed the Trait Meta-Mood Scale-24 (TMMS-24) and the Inventory of Learning and Study Strategies—High School version (LASSI-HS). Cluster analysis identified four EI profiles: a group of adolescents with a high EI profile, a group with predominance of low emotional attention and high repair skills, a group with high scores on attention and low scores on clarity and repair, and a final group of adolescents with low EI. Also, students in groups with high overall scores in EI and low attention and high repair emotional obtained higher scores on the different learning strategies; however, the effect size analysis showed that these differences had no empirical relevance.

Understanding Dropout and Prolonged Engagement in Adolescent Competitive Sport

Objectives: The purpose of this study is to gain understanding of training patterns and roles of significant others (i.e. coaches, parents, peers, and siblings) in adolescent swimmers’ sport participation patterns. Design: The developmental model of sport participation [Côté, J., Baker, J., & Abernethy, B. (2003). From play to practice: A developmental framework for the acquisition of expertise in team sport. In J. Starkes, & K. A. Ericsson (Eds.), Recent advances in research on sport expertise (pp. 89–114). Champaign, IL: Human Kinetics; Côté, J., & Fraser-Thomas, J. (2007). Youth involvement in sport. In P. R. E. Crocker (Ed.), Introduction to sport psychology: A Canadian perspective (pp. 266–294). Toronto: Pearson Prentice Hall] was used as a framework. Method: Ten dropout and 10 engaged swimmers, matched on key demographic variables participated in a semi-structured qualitative interview. Results: Groups had many similar experiences (e.g. early training, supportive and unsupportive coaches, involved parents). However, only dropouts spoke of early peak performances, limited one-on-one coaching, pressuring parents during adolescence, lack of swimming peers during adolescence, and sibling rivalries. In contrast, only engaged athletes spoke of clubs’ developmental philosophies, coaches’ and parents’ open communication, school friends’ support, and siblings’ general positive influences. Conclusions: Findings highlight the importance of appropriately structured programs and the fragility of athletes’ relationships with significant others during the adolescent years. Implications for sport programmers, coaches, and parents are discussed.

HELPING YOUTH WITH AUTISM SPECTRUM DISORDER DEVELOP SOCIAL COMPETENCE IN COMMUNITY-BASED SETTINGS

The purpose of the current dissertation is to identify the features of effective interventions by exploring the experiences of youth with ASD who participate in such interventions, through two intervention studies (Studies 1 and 2) and one interview study (Study 3). Studies 1 and 2 were designed to support the development of social competence of youth with ASD through Structured Play with LEGO TM (Study 1, 12 youths with ASD, ages 7–12) and Minecraft TM (Study 2, 4 youths with ASD, ages 11–13). Over the course of the sessions, the play of the youth developed from parallel play (children playing alone, without interacting) to co-operative play (playing together with shared objectives). The results of Study 2 showed that rates of initiations and levels of engagement increased from the first session to the final session. In Study 3, 12 youths with ASD (ages 10–14) and at least one of their parents were interviewed to explore what children and their parents want from programs designed to improve social competence, which activities and practices were perceived to promote social competence by the participants, and which factors affected their decisions regarding these programs. The adolescents and parents looked for programs that supported social development and emotional wellbeing, but did not always have access to the programs they would have preferred, with factors such as cost and location reducing their options. Three overarching themes emerged through analysis of the three studies: (a) interests of the youth; (b) structure, both through interactions and instruction; and (c) naturalistic settings. Adolescents generally engage more willingly in interventions that incorporate their interests, such as play with Minecraft TM in Study 2. Additionally, Structured Play and structured instruction were crucial components of providing safe and supportive contexts for the development of social competence. Finally, skills learned in naturalistic settings tend to be applied more successfully in everyday situations. The themes are analysed through the lens of Vygotsky’s (1978) perspectives on learning, play, and development. Implications of the results for practitioners and researchers are discussed.

The Influence of the Family in the Development of Talent in Sport

The purpose of the present study was to describe patterns in the dynamics of families of talented athletes throughout their development in sport. Four families, including three families of elite rowers and one family of an elite tennis player were examined. The framework provided by Ericsson, Krampe, and Tesch- Römer (1993) to explain expert performance served as the theoretical basis for the study. Ericsson et al. suggested that the acquisition of expert performance involves operating within three types of constraints: motivational, effort, and resource. In-depth interviews were conducted with each athlete, parent, and sibling to explore how they have dealt with these three constraints. A total of 15 individual interviews were conducted. Results permitted the identification of three phases of participation from early childhood to late adolescence: the sampling years, the specializing years, and the investment years. The dynamics of the family in each of these phases of development is discussed

Childhood Physical Activity Involvement in Active and Inactive Female Adults

Current trends show progressive declines in levels of physical activity from childhood through adolescence and adulthood, most notably for females. The current study examined organized activity involvement in active and inactive females (age 18) using retrospective data. Results indicated that active females participated in significantly more physical activities than inactive females from age 6 to age 18. No significant differences were found between groups for non-physical activities. In addition, parents of active and inactive females were the most influential factor in initiating physical activity. However, parents of active females initiated more physical activity involvement than did parents of inactive females. Results also indicate that certain periods in childhood and adolescence appear to be critical for developing long-term physical activity habits.

Predictors and Consequences of Simultaneous Alcohol and Cannabis Use in Adolescents

Background/Aims: The simultaneous use of alcohol and cannabis is common among adolescents, but has been little studied. In this study, we examine predictors and consequences of this behavior in a population-based sample of high school students. Method: Self-reports were obtained from students in Quebec (Canada) followed throughout high school (N=6589). Logistic regressions were used to test the association between individual, family, and peerrelated predictors in grades 7–8 and simultaneous alcohol and cannabis use in grade 10, as well as between simultaneous alcohol and cannabis use in grade 10 and experiencing 3 or more substance-related problems of various types (legal, physical, etc.) in grade 11. Results: Most predictors in grades 7–8 were associated with simultaneous alcohol and cannabis use in grade 10. Only variables reflecting early-onset substance use involvement — alcohol intoxication, cannabis use, and drug use by close friend(s) — remained predictive in a multivariate model. Simultaneous alcohol and cannabis use was associated with increased substance-related problems in grade 11, above and beyond baseline problems and the concurrent use of the two substances in separate episodes in grade 10. Conclusions: Simultaneous alcohol and cannabis use 1) is anticipated by multiple psychosocial risk factors which come together with individual and peer substance use in early high school and 2) is independently predictive of subsequent substance-related problems. Providing adolescents with adequate information regarding the potential harm of simultaneous use may be a useful prevention strategy.

Prospective associations between meth/amphetamine (speed) and MDMA (ecstasy) use and depressive symptoms in secondary school students

Background Research has raised significant concern regarding the affective consequences of synthetic drug use. However, little evidence from well-controlled longitudinal studies exists on these consequences. The aim of this study was to determine whether use of meth/amphetamine (speed) and 63,4- methylenedioxymethamphetamine (MDMA, ecstasy) is independently predictive of subsequent depressive symptoms in adolescents. Methods A sample of 3880 adolescents from secondary schools in disadvantaged areas of Quebec, Canada, were followed over time (2003e2008). Logistic regression was used to test the association between meth/ amphetamine and MDMA use in grade 10 (ages 15e16 years) and elevated depressive symptoms on an abridged Center for Epidemiologic Studies-Depression scale in grade 11, controlling for pre-existing individual and contextual characteristics. Results After adjustment, both MDMA use (OR 1.7, 95% CI 1.1 to 2.6) and meth/amphetamine use (OR 1.6, 95% CI 1.1 to 2.3) in grade 10 significantly increased the odds of elevated depressive symptoms in grade 11. These relationships did not vary by gender or pre-existing depressive symptoms. Increased risk was particularly observed in concurrent usage (OR 1.9, 95% CI 1.2 to 2.9). Conclusions Adolescent use of meth/amphetamine and MDMA (particularly concurrent use) is independently associated with subsequent depressive symptoms. Further enquiry must determine whether these associations reflect drug-induced neurotoxicity and whether adolescence is a period of increased vulnerability to the hazards of synthetic drug exposure.

Moderators of two Indicated Cognitive-Behavioral Depression Prevention Approaches for Adolescents in a School-Based Effectiveness Trial

Objective: Our aim was to identify moderators of the effects of a cognitive behavioral group-based prevention program (CB group) and CB bibliotherapy, relative to an educational brochure control condition and to one another, in a school-based effectiveness randomized controlled prevention trial. Method: 378 adolescents (M age ¼ 15.5, 68% female) with elevated depressive symptoms were randomized in one of three conditions and were assessed at pretest, posttest, and 6-month follow-up. We tested the moderating effect of three individual (baseline depressive symptoms, negative attributional style, substance use), three environmental (negative life events, parental support, peer support), and two sociodemographic (sex, age) characteristics. Results: Baseline depressive symptoms interacted with condition and time. Decomposition indicated that elevated baseline depressive symptoms amplified the effect of CB bibliotherapy at posttest (but not 6-month follow-up) relative to the control condition, but did not modify the effect of CB group relative to the control condition or relative to bibliotherapy. Specifically, CB bibliotherapy resulted in lower posttest depressive symptoms than the control condition in individuals with elevated, but not average or low baseline symptoms. We found no interaction effect for other putative moderators. Conclusions: Our findings suggest that bibliotherapy is effective only in participants who have elevated depressive symptoms at baseline. The fact that no study variable moderated the effects of CB group, which had a significant main effect in reducing depressive symptoms relative to the control condition, suggests that this indicated prevention intervention is effective for a wide range of adolescents.

Group-Based Symptom Trajectories in Indicated Prevention of Adolescent Depression

Background: Adolescent depression prevention research has focused on mean intervention outcomes, but has not considered heterogeneity in symptom course. Here, we empirically identify subgroups with distinct trajectories of depressive symptom change among adolescents enrolled in two indicated depression preven- tion trials and examine how cognitive-behavioral (CB) interventions and baseline predictors relate to trajectory membership. Methods: Six hundred thirty-one participants were assigned to one of three conditions: CB group intervention, CB bibliotherapy, and brochure control. We used group-based trajectory modeling to identify trajectories of depressive symptoms from pretest to 2-year follow-up. We examined associations between class membership and conditions using chi- square tests and baseline predictors using multinomial regressions. Results: We identified four trajectories in the full sample. Qualitatively similar trajectories were found in each condition separately. Two trajectories of positive symptom course (low-declining, high-declining) had declining symptoms and were dis- tinguished by baseline symptom severity. Two trajectories of negative course (high-persistent, resurging), respectively, showed no decline in symptoms or de- cline followed by symptom reappearance. Participants in the brochure control condition were significantly more likely to populate the high-persistent trajectory relative to either CB condition and were significantly less likely to populate the low-declining trajectory relative to CB group. Several baseline factors predicted trajectory classes, but gender was the most informative prognostic factor, with males having increased odds of membership in a high-persistent trajectory rel- ative to other trajectories. Conclusions: Findings suggest that CB preventive interventions do not alter the nature of trajectories, but reduce the risk that adolescents follow a trajectory of chronically elevated symptoms.