Aggressive Marital Conflict, Maternal Harsh Punishment, and Child Aggressive-Disruptive Behavior: Evidence for Direct and Mediated Relations

PubMed Central

Erath, Stephen A.; Bierman, Karen L.

2009-01-01

Direct associations between aggressive marital conflict and child aggressive-disruptive behavior at home and school were explored in this cross-sectional study of 360 kindergarten children. In addition, mediated pathways linking aggressive marital conflict to maternal harsh punishment to child aggressive-disruptive behavior were examined. Moderation analyses explored how the overall frequency of marital disagreement might buffer or exacerbate the impact of aggressive marital conflict on maternal harsh punishment and child aggressive-disruptive behavior. Hierarchical regressions revealed direct pathways linking aggressive marital conflict to child aggressive-disruptive behavior at home and school and a partially mediated pathway linking aggressive marital conflict to child aggressive-disruptive behavior at home. Further analyses revealed that rates of marital disagreement moderated the association between aggressive marital conflict and child aggressive-disruptive behavior at home, with an attenuated association at high rates of marital disagreement as compared with low rates of marital disagreement. PMID:16756397

Violent Offending Predicts P300 Amplitude

PubMed Central

Bernat, Edward M.; Hall, Jason R.; Steffen, Benjamin V.; Patrick, Christopher J.

2007-01-01

Prior work has consistently revealed a relationship between antisocial behavior and reduced P300 amplitude. Fewer studies have directly evaluated behavioral indices of aggression and P300, and those that have generally do not account for potential mediating variables such as age, intelligence, and behavioral task performance. The current study assessed the relationship between the total number of convicted violent and non-violent offenses and P300 in a sample of inmates from a medium security state prison. Violent offenses evidenced a robust negative relationship with P300 amplitude, whereas non-violent offenses did not. Additional analyses evaluated age, intelligence, and behavioral task performance as potential mediating variables. Only reaction time significantly predicted P300 amplitude, and mediational analyses showed that this relationship did not account for the violent-offense/P300 relationship. Findings are discussed in terms of personality correlates and neurobiological process related to aggression. PMID:17555836

Investigating the effect of nurse-team communication on nurse turnover: relationships among communication processes, identification, and intent to leave.

PubMed

Apker, Julie; Propp, Kathleen M; Ford, Wendy S Zabava

2009-03-01

Enhanced team communication may strengthen nurses' attachment to their organizations and teams and improve nurse retention. This study examines the relationships among nurse-team communication, identification (organizational and team), and intent to leave. Hospital nurses (N = 201) completed surveys measuring 3 nurse-team communication processes: promoting team synergy, ensuring quality decisions, and individualizing communication. Hierarchical regression analyses revealed that promoting team synergy was a significant predictor of intent to leave, whereas ensuring quality decisions and individualizing communication did not account for significant additional variance in intent to leave. Separate analyses showed that the relationship between promoting team synergy and intent to leave was partially mediated by team identification or by organizational identification. Further analyses were conducted on the 7 communication practices for promoting team synergy. Mentoring emerged as the only significant predictor of intent to leave; however, its relationship to intent to leave was fully mediated by organizational identification or partially mediated by team identification. Pragmatic suggestions are offered to improve nurse identification and reduce turnover.

Family functioning mediates adaptation in caregivers of individuals with Rett syndrome.

PubMed

Lamb, Amanda E; Biesecker, Barbara B; Umstead, Kendall L; Muratori, Michelle; Biesecker, Leslie G; Erby, Lori H

2016-11-01

The objective of this study was to investigate factors related to family functioning and adaptation in caregivers of individuals with Rett syndrome (RS). A cross-sectional quantitative survey explored the relationships between demographics, parental self-efficacy, coping methods, family functioning and adaptation. A forward-backward, step-wise model selection procedure was used to evaluate variables associated with both family functioning and adaptation. Analyses also explored family functioning as a mediator of the relationship between other variables and adaptation. Bivariate analyses (N=400) revealed that greater parental self-efficacy, a greater proportion of problem-focused coping, and a lesser proportion of emotion-focused coping were associated with more effective family functioning. In addition, these key variables were significantly associated with greater adaptation, as was family functioning, while controlling for confounders. Finally, regression analyses suggest family functioning as a mediator of the relationships between three variables (parental self-efficacy, problem-focused coping, and emotion-focused coping) with adaptation. This study demonstrates the potentially predictive roles of expectations and coping methods and the mediator role of family functioning in adaptation among caregivers of individuals with RS, a chronic developmental disorder. A potential target for intervention is strengthening of caregiver competence in the parenting role to enhance caregiver adaptation. Published by Elsevier Ireland Ltd.

Negative Body Attitudes and Sexual Dissatisfaction in Men: The Mediating Role of Body Self-Consciousness During Physical Intimacy.

PubMed

van den Brink, Femke; Vollmann, Manja; Sternheim, Lot C; Berkhout, Lotte J; Zomerdijk, Renée A; Woertman, Liesbeth

2018-04-01

Previous research indicated that negative attitudes about the body and appearance are common among men and demonstrated that negative body attitudes are associated with negative sexual experiences. The present study investigated the association between body attitudes and sexual dissatisfaction and the mediating role of body self-consciousness during physical intimacy. In a cross-sectional design, 201 Dutch men completed an online survey regarding body attitudes toward muscularity, body fat, height, and genitals, body self-consciousness during physical intimacy, and sexual dissatisfaction. Hypotheses were tested using correlation analyses and a mediation analysis with body attitudes as predictors, body self-consciousness as mediator, and sexual dissatisfaction as outcome. Correlation analyses showed that negative body attitudes and body self-consciousness during physical intimacy were significantly related to sexual dissatisfaction. The mediation analysis revealed that negative attitudes toward muscularity, body fat, and genitals had indirect effects on sexual dissatisfaction through body self-consciousness during physical intimacy. Negative attitudes toward genitals additionally had a direct effect on sexual dissatisfaction. These findings indicate that body image interventions focused on male body attitudes may be beneficial in improving men's body image, which may ultimately increase sexual satisfaction.

Infant SES as a Predictor of Personality—Is the Association Mediated by Intelligence?

PubMed Central

Flensborg-Madsen, Trine; Mortensen, Erik Lykke

2014-01-01

Background Although research into the continuity and change of personality traits during a lifespan has been fairly extensive, little research has been conducted on childhood predictors of adult personality. Purpose We aimed to investigate the association between infant socioeconomic status (SES), and Eysenck personality traits in adulthood. An additional aim was to investigate whether intelligence and education may mediate this association. Methods SES of 9125 children in the Copenhagen Perinatal Cohort was recorded at a 1-year examination. A subsample of this cohort, comprising 1182 individuals, participated in a follow-up at 20–34 years and was administered the Eysenck Personality Questionnaire (EPQ) which includes measures of neuroticism, extraversion, psychoticism and the so-called lie-scale. Associations of SES with each of the four personality traits were analysed by bivariate and partial correlations, and the mediating effects of intelligence and years of education were analysed. Results Higher SES in infancy was associated with lower neuroticism (r = −0.06; p = 0.05), lower lie-scale scores (r = −0.11; p = 0.0002), and higher psychoticism (r = 0.09; p = 0.003). However, analyses of mediation revealed no direct effect of infant SES on any of the adult personality traits, but only indirect effects mediated by intelligence and years of education, with intelligence being the main mediating factor. Conclusion Only weak associations were observed between infant SES and personality in young adulthood, and the observed associations were mediated by adult intelligence and educational level. Thus, factors associated with infant SES or family background appears to have weak direct effects on personality development. PMID:25078408

A novel derivative of decursin, CSL-32, blocks migration and production of inflammatory mediators and modulates PI3K and NF-κB activities in HT1080 cells.

PubMed

Lee, Seung-Hee; Lee, Jee Hyun; Kim, Eun-Ju; Kim, Won-Jung; Suk, Kyoungho; Kim, Joo-Hwan; Song, Gyu Yong; Lee, Won-Ha

2012-07-01

Decursin and related coumarin compounds in herbal extracts have a number of biological activities against inflammation, angiogenesis and cancer. We have analysed a derivative of decursin (CSL-32) for activity against inflammatory activation of cancer cells, such as migration, invasion and expression of pro-inflammatory mediators. The human fibrosarcoma cell line, HT1080, was treated with TNFα (tumour necrosis factor α) in the presence or absence of CSL-32. The cellular responses and modification of signalling adapters were analysed with respect to the production of pro-inflammatory mediators, as also migration, adhesion and invasion. Treatment of HT1080 cells with CSL-32 inhibited their proliferation, without affecting cell viability, and TNFα-induced expression of pro-inflammatory mediators, such as MMP-9 (matrix metalloproteinase-9) and IL-8 (interleukin-8). CSL-32 also suppressed phosphorylation and degradation of IκB (inhibitory κB), phosphorylation of p65 subunit of NF-κB (nuclear factor-κB) and nuclear translocation of NF-κB, which are required for the expression of pro-inflammatory mediators. In addition, CSL-32 inhibited invasion and migration of HT1080 cells, as also cellular adhesion to fibronectin, an ECM (extracellular matrix) protein. CSL-32 treatment resulted in a dose-dependent inhibition of PI3K (phosphoinositide 3-kinase) activity, required for the cellular migration. The analyses show that CSL-32 inhibits processes associated with inflammation, such as the production of pro-inflammatory mediators, as well as adhesion, migration and invasion in HT1080 cells.

Marital relationship, parenting practices, and social skills development in preschool children.

PubMed

Hosokawa, Rikuya; Katsura, Toshiki

2017-01-01

This study examined the pathways by which destructive and constructive marital conflict leading to social skills development in preschool children, are mediated through negative and positive parenting practices. Mothers of 2931 Japanese children, aged 5-6 years, completed self-report questionnaires regarding their marital relationship (the Quality of co-parental communication scale) and parental practices (the Alabama parenting questionnaire). The children's teachers evaluated their social skills using the Social skills scale. Path analyses revealed significant direct paths from destructive marital conflict to negative parenting practices and lower scores on the self-control component of social skills. In addition, negative parenting practices mediated the relationship between destructive marital conflict and lower scores on cooperation, self-control, and assertion. Our analyses also revealed significant direct paths from constructive marital conflict to positive parenting practices, and higher scores on cooperation and assertion. Positive parenting practices mediated the relationship between constructive marital conflict and higher scores on self-control and assertion. These findings suggest that destructive and constructive marital conflict may directly and indirectly influence children's social skills development through the mediation of parenting practices.

Emotion dysregulation mediates the relationship between child maltreatment and psychopathology: A structural equation model.

PubMed

Jennissen, Simone; Holl, Julia; Mai, Hannah; Wolff, Sebastian; Barnow, Sven

2016-12-01

The present study investigated the mediating effects of emotion dysregulation on the relationship between child maltreatment and psychopathology. An adult sample (N=701) from diverse backgrounds of psychopathology completed the Childhood Trauma Questionnaire (CTQ), the Difficulties in Emotion Regulation Scale (DERS), the Brief Symptom Inventory (BSI), and the negative affect subscale of the Positive and Negative Affect Schedule (PANAS) in a cross-sectional online survey. Correlational analyses showed that all types of child maltreatment were uniformly associated with emotion dysregulation, and dimensions of emotion dysregulation were strongly related to psychopathology. Limited access to strategies for emotion regulation emerged as the most powerful predictor. Structural equation modeling analyses revealed that emotion dysregulation partially mediated the relationship between child maltreatment and psychopathology, even after controlling for shared variance with negative affect. These findings emphasize the importance of emotion dysregulation as a possible mediating mechanism in the association between child maltreatment and later psychopathology. Additionally, interventions targeting specific emotion regulation strategies may be effective to reduce psychopathology in victims of child maltreatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Maternal depression, paternal psychopathology, and adolescent diagnostic outcomes.

PubMed

Brennan, Patricia A; Hammen, Constance; Katz, Anna R; Le Brocque, Robyne M

2002-10-01

The authors examined the relationship between maternal depression, paternal psychopathology, and adolescent diagnostic outcomes in a community sample of 522 Australian families. They also examined whether chronic family stress, father's expressed emotion, and parents' marital satisfaction mediated the relationship between parental psychopathology and adolescent outcomes. Mother's education, child's gender, and family income were covaried in all analyses. Results revealed that maternal depression and paternal depression had an additive effect on youth externalizing disorders. In addition, maternal depression interacted with both paternal depression and paternal substance abuse in predicting youth depression but not youth nondepressive disorders. Chronic family stress and father's expressed emotion appeared to mediate the relationship between parental psychopathology and youth depression.

Direct and vicarious violent victimization and juvenile delinquency: an application of general strain theory.

PubMed

Lin, Wen-Hsu; Cochran, John K; Mieczkowski, Thomas

2011-01-01

Using a national probability sample of adolescents (12–17), this study applies general strain theory to how violent victimization, vicarious violent victimization, and dual violent victimization affect juvenile violent/property crime and drug use. In addition, the mediating effect and moderating effect of depression, low social control, and delinquent peer association on the victimization–delinquency relationship is also examined. Based on SEM analyses and contingency tables, the results indicate that all three types of violent victimization have significant and positive direct effects on violent/property crime and drug use. In addition, the expected mediating effects and moderating effects are also found. Limitations and future directions are discussed.

Satisfaction with Life Scale (SWLS) in Caregivers of Clinically-Referred Youth: Psychometric Properties and Mediation Analysis

PubMed Central

Athay, M. Michele

2012-01-01

This paper presents the psychometric evaluation of the Satisfaction with Life Scale (SWLS; Diener, Emmons, Larson & Griffen, 1985) used with a large sample (N = 610) of caregivers for youth receiving mental health services. Methods from classical test theory, factor analysis and item response theory are utilized. Additionally, this paper investigates whether caregiver strain mediates the effect of youth symptom severity on caregiver life satisfaction (N = 356). Bootstrapped confidence intervals are used to determine the significance of the mediated effects. Results indicate that the SWLS is a psychometrically sound instrument to be used with caregivers of clinically-referred youth. Mediation analyses found that the effect of youth symptom severity on caregiver life satisfaction is mediated by caregiver strain but that the mediation effect differs based on the type of youth symptoms. Caregiver strain is a partial mediator when externalizing symptoms are measured and a full mediator when internalizing symptoms are measured. Implications for future research and clinical practice are discussed. PMID:22407554

Direct and indirect effects of organizational justice on work ability.

PubMed

Spanier, K; Radoschewski, F M; Gutenbrunner, C; Bethge, M

2014-12-01

Organizational justice (OJ), involving transparent workplace procedures and treating staff members with respect, has been of growing concern in recent epidemiological research as a determinant of health-related outcomes. To examine the factorial validity of the German version of Moorman's Organizational Justice Questionnaire (OJQ), to investigate the direct cross-sectional effect of OJ on self-rated work ability and to analyse if there is an additional indirect effect of OJ on work ability mediated by effort-reward imbalance. An analysis of cross-sectional data from the Second German Sociomedical Panel of Employees, involving white-collar workers employed at least half time. We performed confirmatory factor analyses to test the factorial validity of the OJQ and analysed the direct and indirect associations of OJ and self-rated work ability by path model analysis. Of the 1217 participants (47% female; mean age: 51) 36% had poor work ability. Factor analyses confirmed the two-factor structure of the German OJQ. Work ability was explained directly by OJ (β = 0.30) and effort-reward imbalance (β = -0.27). Additionally, we identified an indirect effect of OJ that was mediated by effort-reward imbalance (β = 0.14). The total effect of OJ on work ability was remarkably strong (β = 0.44). Associations remained unchanged after adjustment for socio-demographic parameters. This study showed the importance of considering additional indirect pathways when examining the impact of OJ on the work ability of employees. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Team Learning: Building Shared Mental Models

ERIC Educational Resources Information Center

Van den Bossche, Piet; Gijselaers, Wim; Segers, Mien; Woltjer, Geert; Kirschner, Paul

2011-01-01

To gain insight in the social processes that underlie knowledge sharing in teams, this article questions which team learning behaviors lead to the construction of a shared mental model. Additionally, it explores how the development of shared mental models mediates the relation between team learning behaviors and team effectiveness. Analyses were…

Oral Conversations Online: Redefining Oral Competence in Synchronous Environments

ERIC Educational Resources Information Center

Lamy, Marie-Noelle

2004-01-01

In this article the focus is on methodology for analysing learner-learner oral conversations mediated by computers. With the increasing availability of synchronous voice-based groupware and the additional facilities offered by audio-graphic tools, language learners have opportunities for collaborating on oral tasks, supported by visual and textual…

Examining the stress-burnout relationship: the mediating role of negative thoughts

PubMed Central

Chyi, Theresa; Hsu, Ya-Wen; Chan, Shi-Wei; Wang, Erica T.W.

2017-01-01

Background Using Smith’s (1986) cognitive-affective model of athletic burnout as a guiding framework, the purpose of this study was to examine the relationships among athletes’ stress in life, negative thoughts, and the mediating role of negative thoughts on the stress-burnout relationship. Methods A total of 300 college student-athletes (males = 174; females = 126, Mage = 20.43 y, SD = 1.68) completed the College Student Athlete’s Life Stress Scale (CSALSS; Lu et al., 2012), the Automatic Thoughts Questionnaire (ATQ; Hollon & Kendall, 1980), and the Athlete Burnout Questionnaire (ABQ; Raedeke & Smith, 2001). Results Correlational analyses found that two types of life stress and four types of negative thoughts correlated with burnout. Additionally, hierarchical regression analyses found that four types of negative thoughts partially mediated the stress-burnout relationship. Discussion We concluded that an athlete’s negative thoughts play a pivotal role in predicting athletes’ stress-burnout relationship. Future study may examine how irrational cognition influences athletes’ motivation and psychological well-being. PMID:29302397

The role of early language abilities on math skills among Chinese children.

PubMed

Zhang, Juan; Fan, Xitao; Cheung, Sum Kwing; Meng, Yaxuan; Cai, Zhihui; Hu, Bi Ying

2017-01-01

The present study investigated the role of early language abilities in the development of math skills among Chinese K-3 students. About 2000 children in China, who were on average aged 6 years, were assessed for both informal math (e.g., basic number concepts such as counting objects) and formal math (calculations including addition and subtraction) skills, language abilities and nonverbal intelligence. Correlation analysis showed that language abilities were more strongly associated with informal than formal math skills, and regression analyses revealed that children's language abilities could uniquely predict both informal and formal math skills with age, gender, and nonverbal intelligence controlled. Mediation analyses demonstrated that the relationship between children's language abilities and formal math skills was partially mediated by informal math skills. The current findings indicate 1) Children's language abilities are of strong predictive values for both informal and formal math skills; 2) Language abilities impacts formal math skills partially through the mediation of informal math skills.

The role of early language abilities on math skills among Chinese children

PubMed Central

Fan, Xitao; Cheung, Sum Kwing; Cai, Zhihui; Hu, Bi Ying

2017-01-01

Background The present study investigated the role of early language abilities in the development of math skills among Chinese K-3 students. About 2000 children in China, who were on average aged 6 years, were assessed for both informal math (e.g., basic number concepts such as counting objects) and formal math (calculations including addition and subtraction) skills, language abilities and nonverbal intelligence. Methodology Correlation analysis showed that language abilities were more strongly associated with informal than formal math skills, and regression analyses revealed that children’s language abilities could uniquely predict both informal and formal math skills with age, gender, and nonverbal intelligence controlled. Mediation analyses demonstrated that the relationship between children’s language abilities and formal math skills was partially mediated by informal math skills. Results The current findings indicate 1) Children’s language abilities are of strong predictive values for both informal and formal math skills; 2) Language abilities impacts formal math skills partially through the mediation of informal math skills. PMID:28749950

Examining the stress-burnout relationship: the mediating role of negative thoughts.

PubMed

Chang, Ko-Hsin; Lu, Frank J H; Chyi, Theresa; Hsu, Ya-Wen; Chan, Shi-Wei; Wang, Erica T W

2017-01-01

Using Smith's (1986) cognitive-affective model of athletic burnout as a guiding framework, the purpose of this study was to examine the relationships among athletes' stress in life, negative thoughts, and the mediating role of negative thoughts on the stress-burnout relationship. A total of 300 college student-athletes (males = 174; females = 126, M age  = 20.43 y, SD = 1.68) completed the College Student Athlete's Life Stress Scale (CSALSS; Lu et al., 2012), the Automatic Thoughts Questionnaire (ATQ; Hollon & Kendall, 1980), and the Athlete Burnout Questionnaire (ABQ; Raedeke & Smith, 2001). Correlational analyses found that two types of life stress and four types of negative thoughts correlated with burnout. Additionally, hierarchical regression analyses found that four types of negative thoughts partially mediated the stress-burnout relationship. We concluded that an athlete's negative thoughts play a pivotal role in predicting athletes' stress-burnout relationship. Future study may examine how irrational cognition influences athletes' motivation and psychological well-being.

Examining the Associations Among Home-School Dissonance, Amotivation, and Classroom Disruptive Behavior for Urban High School Students.

PubMed

Brown-Wright, Lynda; Tyler, Kenneth M; Graves, Scott L; Thomas, Deneia; Stevens-Watkins, Danelle; Mulder, Shambra

2013-01-01

The current study examined the association among home-school dissonance, amotivation, and classroom disruptive behavior among 309 high school juniors and seniors at two urban high schools in the Southern region of the country. Students completed two subscales of the Patterns of Learning Activities Scales (PALS) and one subscale of the Academic Motivation Scale (AMS). ANCOVA analyses revealed significant differences in classroom disruptive behaviors for the gender independent variable. Controlling for gender in the multiple hierarchical regression analyses, it was revealed that home-school dissonance significantly predicted both amotivation and classroom disruptive behavior. In addition, a Sobel mediation analysis showed that amotivation was a significant mediator of the association between home-school dissonance and classroom disruptive behavior. Findings and limitations are discussed.

Examining the Associations Among Home–School Dissonance, Amotivation, and Classroom Disruptive Behavior for Urban High School Students

PubMed Central

Brown-Wright, Lynda; Tyler, Kenneth M.; Graves, Scott L.; Thomas, Deneia; Stevens-Watkins, Danelle; Mulder, Shambra

2015-01-01

The current study examined the association among home–school dissonance, amotivation, and classroom disruptive behavior among 309 high school juniors and seniors at two urban high schools in the Southern region of the country. Students completed two subscales of the Patterns of Learning Activities Scales (PALS) and one subscale of the Academic Motivation Scale (AMS). ANCOVA analyses revealed significant differences in classroom disruptive behaviors for the gender independent variable. Controlling for gender in the multiple hierarchical regression analyses, it was revealed that home–school dissonance significantly predicted both amotivation and classroom disruptive behavior. In addition, a Sobel mediation analysis showed that amotivation was a significant mediator of the association between home–school dissonance and classroom disruptive behavior. Findings and limitations are discussed. PMID:27081213

What works in school-based energy balance behaviour interventions and what does not? A systematic review of mediating mechanisms.

PubMed

van Stralen, M M; Yildirim, M; te Velde, S J; Brug, J; van Mechelen, W; Chinapaw, M J M

2011-10-01

Obesity prevention requires effective interventions targeting the so-called energy balance-related behaviours (that is, physical activity, sedentary and dietary behaviours). To improve (cost-)effectiveness of these interventions, one needs to know the working mechanisms underlying behavioural change. Mediation analyses evaluates whether an intervention works via hypothesised working mechanisms. Identifying mediators can prompt intervention developers to strengthen effective intervention components and remove/adapt ineffective components. This systematic review aims to identify psychosocial and environmental mediators of energy balance-related behaviours interventions for youth. Studies were identified by a systematic search of electronic databases (PubMed, Embase, PsycINFO, ERIC and SPORTDiscus). Studies were included if they (1) were school-based randomised controlled or quasi-experimental studies; (2) targeted energy balance behaviours; (3) conducted among children and adolescents (4-18 years of age); (4) written in English; and (5) conducted mediation analyses. A total of 24 studies were included. We found strong evidence for self-efficacy and moderate evidence for intention as mediators of physical activity interventions. Indications were found for attitude, knowledge and habit strength to be mediators of dietary behaviour interventions. The few sedentary behaviour interventions reporting on mediating effects prevented us from forming strong conclusions regarding mediators of sedentary behaviour interventions. The majority of interventions failed to significantly change hypothesised mediators because of ineffective intervention strategies, low power and/or use of insensitive measures. Despite its importance, few studies published results of mediation analysis, and more high-quality research into relevant mediators is necessary. On the basis of the limited number of published studies, self-efficacy and intention appear to be relevant mediators for physical activity interventions. Future intervention developers are advised to provide information on the theoretical base of their intervention including the strategies applied to provide insight into which strategies are effective in changing relevant mediators. In addition, future research is advised to focus on the development, validity, reliability and sensitivity of mediator measures.

What works in school-based energy balance behaviour interventions and what does not? A systematic review of mediating mechanisms

PubMed Central

van Stralen, M M; Yildirim, M; Velde, SJ te; Brug, J; van Mechelen, W; Chinapaw, M J M

2011-01-01

Objective: Obesity prevention requires effective interventions targeting the so-called energy balance-related behaviours (that is, physical activity, sedentary and dietary behaviours). To improve (cost-)effectiveness of these interventions, one needs to know the working mechanisms underlying behavioural change. Mediation analyses evaluates whether an intervention works via hypothesised working mechanisms. Identifying mediators can prompt intervention developers to strengthen effective intervention components and remove/adapt ineffective components. This systematic review aims to identify psychosocial and environmental mediators of energy balance-related behaviours interventions for youth. Method: Studies were identified by a systematic search of electronic databases (Pubmed, Embase, PsycINFO, ERIC and SPORTDiscus). Studies were included if they (1) were school-based randomised controlled or quasi-experimental studies; (2) targeted energy balance behaviours; (3) conducted among children and adolescents (4–18 years of age); (4) written in English; and (5) conducted mediation analyses. Results: A total of 24 studies were included. We found strong evidence for self-efficacy and moderate evidence for intention as mediators of physical activity interventions. Indications were found for attitude, knowledge and habit strength to be mediators of dietary behaviour interventions. The few sedentary behaviour interventions reporting on mediating effects prevented us from forming strong conclusions regarding mediators of sedentary behaviour interventions. The majority of interventions failed to significantly change hypothesised mediators because of ineffective intervention strategies, low power and/or use of insensitive measures. Conclusion: Despite its importance, few studies published results of mediation analysis, and more high-quality research into relevant mediators is necessary. On the basis of the limited number of published studies, self-efficacy and intention appear to be relevant mediators for physical activity interventions. Future intervention developers are advised to provide information on the theoretical base of their intervention including the strategies applied to provide insight into which strategies are effective in changing relevant mediators. In addition, future research is advised to focus on the development, validity, reliability and sensitivity of mediator measures. PMID:21487398

ETHICAL LEADERSHIP AND EMPLOYEE VOICE: EMPLOYEE SELF-EFFICACY AND SELF-IMPACT AS MEDIATORS.

PubMed

Wang, Duanxu; Gan, Chenjing; Wu, Chaoyan; Wang, Danqi

2015-06-01

Previous studies have used social learning theory to explain the influence of ethical leadership. This study continues the previous research by using social learning theory to explain the mediating effect of self-efficacy on the relationship between ethical leadership and employee voice. In addition, this study extends previous studies by introducing expectancy theory to explore whether self-impact also mediates the relationship between ethical leadership and employee voice. Ethical leadership, self-efficacy, self-impact, and employee voice were assessed using paired surveys among 59 supervisors and 295 subordinates employed at nine firms in the People's Republic of China. Using HLM and SEM analyses, the results revealed that ethical leadership was positively related to employee voice and that this relationship was partially mediated by both self-efficacy and self-impact.

Factors influencing quit attempts among male daily smokers in China.

PubMed

Zhao, Luhua; Song, Yang; Xiao, Lin; Palipudi, Krishna; Asma, Samira

2015-12-01

China has the largest population of smokers in the world, yet the quit rate is low. We used data from the 2010 Global Adult Tobacco Survey China to identify factors influencing quit attempts among male Chinese daily smokers. The study sample included 3303 male daily smokers. To determine the factors that were significantly associated with making a quit attempt, we conducted logistic regression analyses. In addition, mediation analyses were carried out to investigate how the intermediate association among demographics (age, education, urbanicity) and smoking-related variables affected making a quit attempt. An estimated 11.0% of male daily smokers tried to quit smoking in the 12 months prior to the survey. Logistic regression analysis indicated that younger age (15-24 years), being advised to quit by a health care provider (HCP) in the past 12 months, lower cigarette cost per pack, monthly or less frequent exposure to smoking at home, and awareness of the harms of tobacco use were significantly associated with making a quit attempt. Additional mediation analyses showed that having knowledge of the harm of tobacco, exposure to smoking at home, and having been advised to quit by an HCP were mediators of making a quit attempt for other independent variables. Evidence-based tobacco control measures such as conducting educational campaigns on the harms of tobacco use, establishing smoke-free policies at home, and integrating tobacco cessation advice into primary health care services can increase quit attempts and reduce smoking among male Chinese daily smokers. Copyright © 2015 Elsevier Inc. All rights reserved.

Mediator and moderator effects in developmental and behavioral pediatric research.

PubMed

Rose, Brigid M; Holmbeck, Grayson N; Coakley, Rachael Millstein; Franks, Elizabeth A

2004-02-01

The terms mediation and moderation are defined and clarified with particular emphasis on the role of mediational and moderational analyses in developmental and behavioral pediatric research. The article highlights the applicability of mediational and moderational analyses to longitudinal, intervention, and risk and protective factor research, and it provides basic information about how these analyses might be conducted. Also included is a discussion of various ways that both mediator and moderator variables can be incorporated into a single model. The article concludes with extended examples of both types of analyses using a longitudinal pediatric study for illustration. The article provides recommendations for applying mediational and moderational research in clinical practice.

Responsibility attribution of HIV infection and coping among injection drug users in Malaysia.

PubMed

Chou, Chih-Chin; Chronister, Julie; Chou, Chih-Hung; Tan, Sooyin; Macewicz, Thomas

2013-01-01

This study explored responsibility attribution (RA) of HIV/AIDS infection (i.e., how an individual perceives the cause of their HIV/AIDS infection) and its relationship to coping styles among injection drug users (IDUs) with HIV/AIDS. In addition, this study investigated whether self-esteem, social support, and religiosity mediate the relationship between RA and coping styles of IDUs with HIV/AIDS. Participants were 201 adult IDUs with HIV/AIDS participating in the National Drug Rehabilitation Center in Malaysia. Five measures were used to assess the above constructs. Cluster analysis, analysis of variance, and mediation analyses were conducted. Results of this study indicated that IDUs with HIV/AIDS in Malaysia can be classified into four homogenous attribution groups: external, fatalistic, internal, and indeterminate. Mediator analyses revealed that combination of self-esteem, social support, and religiosity mediate the relationship between RA and coping behaviors. Clinicians working with IDUs with HIV/AIDS need to address the role of RA, self-esteem, religiosity, and social support as these psychosocial constructs are linked to coping with HIV/AIDS. Future researchers should investigate whether enhancing self-esteem, social support, and religiosity can promote active problem-solving coping and reduce the use of avoidance coping behaviors.

Longitudinal Relationships of Fitness, Physical Activity, and Weight Status with Academic Achievement in Adolescents

ERIC Educational Resources Information Center

Suchert, Vivien; Hanewinkel, Reiner; Isensee, Barbara

2016-01-01

Background: To examine associations of cardiorespiratory fitness, physical activity (PA) and weight status with academic achievement 1 year later. In addition, the mediating role of psychological variables was tested. Methods: Longitudinal analyses included 1011 German students (M = 14.1 years, SD = 0.6 years). Cardiorespiratory fitness was…

Large-scale genomic analyses link reproductive aging to hypothalamic signaling, breast cancer susceptibility and BRCA1-mediated DNA repair.

PubMed

Day, Felix R; Ruth, Katherine S; Thompson, Deborah J; Lunetta, Kathryn L; Pervjakova, Natalia; Chasman, Daniel I; Stolk, Lisette; Finucane, Hilary K; Sulem, Patrick; Bulik-Sullivan, Brendan; Esko, Tõnu; Johnson, Andrew D; Elks, Cathy E; Franceschini, Nora; He, Chunyan; Altmaier, Elisabeth; Brody, Jennifer A; Franke, Lude L; Huffman, Jennifer E; Keller, Margaux F; McArdle, Patrick F; Nutile, Teresa; Porcu, Eleonora; Robino, Antonietta; Rose, Lynda M; Schick, Ursula M; Smith, Jennifer A; Teumer, Alexander; Traglia, Michela; Vuckovic, Dragana; Yao, Jie; Zhao, Wei; Albrecht, Eva; Amin, Najaf; Corre, Tanguy; Hottenga, Jouke-Jan; Mangino, Massimo; Smith, Albert V; Tanaka, Toshiko; Abecasis, Goncalo; Andrulis, Irene L; Anton-Culver, Hoda; Antoniou, Antonis C; Arndt, Volker; Arnold, Alice M; Barbieri, Caterina; Beckmann, Matthias W; Beeghly-Fadiel, Alicia; Benitez, Javier; Bernstein, Leslie; Bielinski, Suzette J; Blomqvist, Carl; Boerwinkle, Eric; Bogdanova, Natalia V; Bojesen, Stig E; Bolla, Manjeet K; Borresen-Dale, Anne-Lise; Boutin, Thibaud S; Brauch, Hiltrud; Brenner, Hermann; Brüning, Thomas; Burwinkel, Barbara; Campbell, Archie; Campbell, Harry; Chanock, Stephen J; Chapman, J Ross; Chen, Yii-Der Ida; Chenevix-Trench, Georgia; Couch, Fergus J; Coviello, Andrea D; Cox, Angela; Czene, Kamila; Darabi, Hatef; De Vivo, Immaculata; Demerath, Ellen W; Dennis, Joe; Devilee, Peter; Dörk, Thilo; Dos-Santos-Silva, Isabel; Dunning, Alison M; Eicher, John D; Fasching, Peter A; Faul, Jessica D; Figueroa, Jonine; Flesch-Janys, Dieter; Gandin, Ilaria; Garcia, Melissa E; García-Closas, Montserrat; Giles, Graham G; Girotto, Giorgia G; Goldberg, Mark S; González-Neira, Anna; Goodarzi, Mark O; Grove, Megan L; Gudbjartsson, Daniel F; Guénel, Pascal; Guo, Xiuqing; Haiman, Christopher A; Hall, Per; Hamann, Ute; Henderson, Brian E; Hocking, Lynne J; Hofman, Albert; Homuth, Georg; Hooning, Maartje J; Hopper, John L; Hu, Frank B; Huang, Jinyan; Humphreys, Keith; Hunter, David J; Jakubowska, Anna; Jones, Samuel E; Kabisch, Maria; Karasik, David; Knight, Julia A; Kolcic, Ivana; Kooperberg, Charles; Kosma, Veli-Matti; Kriebel, Jennifer; Kristensen, Vessela; Lambrechts, Diether; Langenberg, Claudia; Li, Jingmei; Li, Xin; Lindström, Sara; Liu, Yongmei; Luan, Jian'an; Lubinski, Jan; Mägi, Reedik; Mannermaa, Arto; Manz, Judith; Margolin, Sara; Marten, Jonathan; Martin, Nicholas G; Masciullo, Corrado; Meindl, Alfons; Michailidou, Kyriaki; Mihailov, Evelin; Milani, Lili; Milne, Roger L; Müller-Nurasyid, Martina; Nalls, Michael; Neale, Ben M; Nevanlinna, Heli; Neven, Patrick; Newman, Anne B; Nordestgaard, Børge G; Olson, Janet E; Padmanabhan, Sandosh; Peterlongo, Paolo; Peters, Ulrike; Petersmann, Astrid; Peto, Julian; Pharoah, Paul D P; Pirastu, Nicola N; Pirie, Ailith; Pistis, Giorgio; Polasek, Ozren; Porteous, David; Psaty, Bruce M; Pylkäs, Katri; Radice, Paolo; Raffel, Leslie J; Rivadeneira, Fernando; Rudan, Igor; Rudolph, Anja; Ruggiero, Daniela; Sala, Cinzia F; Sanna, Serena; Sawyer, Elinor J; Schlessinger, David; Schmidt, Marjanka K; Schmidt, Frank; Schmutzler, Rita K; Schoemaker, Minouk J; Scott, Robert A; Seynaeve, Caroline M; Simard, Jacques; Sorice, Rossella; Southey, Melissa C; Stöckl, Doris; Strauch, Konstantin; Swerdlow, Anthony; Taylor, Kent D; Thorsteinsdottir, Unnur; Toland, Amanda E; Tomlinson, Ian; Truong, Thérèse; Tryggvadottir, Laufey; Turner, Stephen T; Vozzi, Diego; Wang, Qin; Wellons, Melissa; Willemsen, Gonneke; Wilson, James F; Winqvist, Robert; Wolffenbuttel, Bruce B H R; Wright, Alan F; Yannoukakos, Drakoulis; Zemunik, Tatijana; Zheng, Wei; Zygmunt, Marek; Bergmann, Sven; Boomsma, Dorret I; Buring, Julie E; Ferrucci, Luigi; Montgomery, Grant W; Gudnason, Vilmundur; Spector, Tim D; van Duijn, Cornelia M; Alizadeh, Behrooz Z; Ciullo, Marina; Crisponi, Laura; Easton, Douglas F; Gasparini, Paolo P; Gieger, Christian; Harris, Tamara B; Hayward, Caroline; Kardia, Sharon L R; Kraft, Peter; McKnight, Barbara; Metspalu, Andres; Morrison, Alanna C; Reiner, Alex P; Ridker, Paul M; Rotter, Jerome I; Toniolo, Daniela; Uitterlinden, André G; Ulivi, Sheila; Völzke, Henry; Wareham, Nicholas J; Weir, David R; Yerges-Armstrong, Laura M; Price, Alkes L; Stefansson, Kari; Visser, Jenny A; Ong, Ken K; Chang-Claude, Jenny; Murabito, Joanne M; Perry, John R B; Murray, Anna

2015-11-01

Menopause timing has a substantial impact on infertility and risk of disease, including breast cancer, but the underlying mechanisms are poorly understood. We report a dual strategy in ∼70,000 women to identify common and low-frequency protein-coding variation associated with age at natural menopause (ANM). We identified 44 regions with common variants, including two regions harboring additional rare missense alleles of large effect. We found enrichment of signals in or near genes involved in delayed puberty, highlighting the first molecular links between the onset and end of reproductive lifespan. Pathway analyses identified major association with DNA damage response (DDR) genes, including the first common coding variant in BRCA1 associated with any complex trait. Mendelian randomization analyses supported a causal effect of later ANM on breast cancer risk (∼6% increase in risk per year; P = 3 × 10(-14)), likely mediated by prolonged sex hormone exposure rather than DDR mechanisms.

Large-scale genomic analyses link reproductive ageing to hypothalamic signaling, breast cancer susceptibility and BRCA1-mediated DNA repair

PubMed Central

Lunetta, Kathryn L.; Pervjakova, Natalia; Chasman, Daniel I.; Stolk, Lisette; Finucane, Hilary K.; Sulem, Patrick; Bulik-Sullivan, Brendan; Esko, Tõnu; Johnson, Andrew D.; Elks, Cathy E.; Franceschini, Nora; He, Chunyan; Altmaier, Elisabeth; Brody, Jennifer A.; Franke, Lude L.; Huffman, Jennifer E.; Keller, Margaux F.; McArdle, Patrick F.; Nutile, Teresa; Porcu, Eleonora; Robino, Antonietta; Rose, Lynda M.; Schick, Ursula M.; Smith, Jennifer A.; Teumer, Alexander; Traglia, Michela; Vuckovic, Dragana; Yao, Jie; Zhao, Wei; Albrecht, Eva; Amin, Najaf; Corre, Tanguy; Hottenga, Jouke-Jan; Mangino, Massimo; Smith, Albert V.; Tanaka, Toshiko; Abecasis, Goncalo; Andrulis, Irene L.; Anton-Culver, Hoda; Antoniou, Antonis C.; Arndt, Volker; Arnold, Alice M.; Barbieri, Caterina; Beckmann, Matthias W.; Beeghly-Fadiel, Alicia; Benitez, Javier; Bernstein, Leslie; Bielinski, Suzette J.; Blomqvist, Carl; Boerwinkle, Eric; Bogdanova, Natalia V.; Bojesen, Stig E.; Bolla, Manjeet K.; Borresen-Dale, Anne-Lise; Boutin, Thibaud S; Brauch, Hiltrud; Brenner, Hermann; Brüning, Thomas; Burwinkel, Barbara; Campbell, Archie; Campbell, Harry; Chanock, Stephen J.; Chapman, J. Ross; Chen, Yii-Der Ida; Chenevix-Trench, Georgia; Couch, Fergus J.; Coviello, Andrea D.; Cox, Angela; Czene, Kamila; Darabi, Hatef; De Vivo, Immaculata; Demerath, Ellen W.; Dennis, Joe; Devilee, Peter; Dörk, Thilo; dos-Santos-Silva, Isabel; Dunning, Alison M.; Eicher, John D.; Fasching, Peter A.; Faul, Jessica D.; Figueroa, Jonine; Flesch-Janys, Dieter; Gandin, Ilaria; Garcia, Melissa E.; García-Closas, Montserrat; Giles, Graham G.; Girotto, Giorgia G.; Goldberg, Mark S.; González-Neira, Anna; Goodarzi, Mark O.; Grove, Megan L.; Gudbjartsson, Daniel F.; Guénel, Pascal; Guo, Xiuqing; Haiman, Christopher A.; Hall, Per; Hamann, Ute; Henderson, Brian E.; Hocking, Lynne J.; Hofman, Albert; Homuth, Georg; Hooning, Maartje J.; Hopper, John L.; Hu, Frank B.; Huang, Jinyan; Humphreys, Keith; Hunter, David J.; Jakubowska, Anna; Jones, Samuel E.; Kabisch, Maria; Karasik, David; Knight, Julia A.; Kolcic, Ivana; Kooperberg, Charles; Kosma, Veli-Matti; Kriebel, Jennifer; Kristensen, Vessela; Lambrechts, Diether; Langenberg, Claudia; Li, Jingmei; Li, Xin; Lindström, Sara; Liu, Yongmei; Luan, Jian’an; Lubinski, Jan; Mägi, Reedik; Mannermaa, Arto; Manz, Judith; Margolin, Sara; Marten, Jonathan; Martin, Nicholas G.; Masciullo, Corrado; Meindl, Alfons; Michailidou, Kyriaki; Mihailov, Evelin; Milani, Lili; Milne, Roger L.; Müller-Nurasyid, Martina; Nalls, Michael; Neale, Ben M.; Nevanlinna, Heli; Neven, Patrick; Newman, Anne B.; Nordestgaard, Børge G.; Olson, Janet E.; Padmanabhan, Sandosh; Peterlongo, Paolo; Peters, Ulrike; Petersmann, Astrid; Peto, Julian; Pharoah, Paul D.P.; Pirastu, Nicola N.; Pirie, Ailith; Pistis, Giorgio; Polasek, Ozren; Porteous, David; Psaty, Bruce M.; Pylkäs, Katri; Radice, Paolo; Raffel, Leslie J.; Rivadeneira, Fernando; Rudan, Igor; Rudolph, Anja; Ruggiero, Daniela; Sala, Cinzia F.; Sanna, Serena; Sawyer, Elinor J.; Schlessinger, David; Schmidt, Marjanka K.; Schmidt, Frank; Schmutzler, Rita K.; Schoemaker, Minouk J.; Scott, Robert A.; Seynaeve, Caroline M.; Simard, Jacques; Sorice, Rossella; Southey, Melissa C.; Stöckl, Doris; Strauch, Konstantin; Swerdlow, Anthony; Taylor, Kent D.; Thorsteinsdottir, Unnur; Toland, Amanda E.; Tomlinson, Ian; Truong, Thérèse; Tryggvadottir, Laufey; Turner, Stephen T.; Vozzi, Diego; Wang, Qin; Wellons, Melissa; Willemsen, Gonneke; Wilson, James F.; Winqvist, Robert; Wolffenbuttel, Bruce B.H.R.; Wright, Alan F.; Yannoukakos, Drakoulis; Zemunik, Tatijana; Zheng, Wei; Zygmunt, Marek; Bergmann, Sven; Boomsma, Dorret I.; Buring, Julie E.; Ferrucci, Luigi; Montgomery, Grant W.; Gudnason, Vilmundur; Spector, Tim D.; van Duijn, Cornelia M; Alizadeh, Behrooz Z.; Ciullo, Marina; Crisponi, Laura; Easton, Douglas F.; Gasparini, Paolo P.; Gieger, Christian; Harris, Tamara B.; Hayward, Caroline; Kardia, Sharon L.R.; Kraft, Peter; McKnight, Barbara; Metspalu, Andres; Morrison, Alanna C.; Reiner, Alex P.; Ridker, Paul M.; Rotter, Jerome I.; Toniolo, Daniela; Uitterlinden, André G.; Ulivi, Sheila; Völzke, Henry; Wareham, Nicholas J.; Weir, David R.; Yerges-Armstrong, Laura M.; Price, Alkes L.; Stefansson, Kari; Visser, Jenny A.; Ong, Ken K.; Chang-Claude, Jenny; Murabito, Joanne M.; Perry, John R.B.; Murray, Anna

2015-01-01

Menopause timing has a substantial impact on infertility and risk of disease, including breast cancer, but the underlying mechanisms are poorly understood. We report a dual strategy in ~70,000 women to identify common and low-frequency protein-coding variation associated with age at natural menopause (ANM). We identified 44 regions with common variants, including two harbouring additional rare missense alleles of large effect. We found enrichment of signals in/near genes involved in delayed puberty, highlighting the first molecular links between the onset and end of reproductive lifespan. Pathway analyses revealed a major association with DNA damage-response (DDR) genes, including the first common coding variant in BRCA1 associated with any complex trait. Mendelian randomisation analyses supported a causal effect of later ANM on breast cancer risk (~6% risk increase per-year, P=3×10−14), likely mediated by prolonged sex hormone exposure, rather than DDR mechanisms. PMID:26414677

Cultural Predictors of Physical and Mental Health Status among Mexican American Women: A Mediation Model

PubMed Central

Dinh, Khanh T.; Castro, Felipe González; Tein, Jenn-Yun; Kim, Su Yeong

2016-01-01

This study, using secondary data analysis, examined a mediation model of acculturation and ethnic pride as predictors of physical and mental health outcomes in a sample of 561 Mexican American women. Factors postulated as mediators were family support and religiosity. Systematic across-group comparison analyses were conducted to examine sources of differences in the mediation model between immigrant and non-immigrant women. The results partially supported the hypothesized mediation model, indicating that family support, but not religiosity, was a significant mediator in the relationship between ethnic pride and mental health problems. In addition, as differences between immigrant and non-immigrant women were observed only in the variables means, but not in the factor loadings or regression paths, the model tested may capture a common psychosocial process that affects these women and their health outcomes. Overall, this study offers important implications for future research and the design of intervention programs for Mexican American women. PMID:19130212

Distinguishing Mediational Models and Analyses in Clinical Psychology: Atemporal Associations Do Not Imply Causation.

PubMed

Winer, E Samuel; Cervone, Daniel; Bryant, Jessica; McKinney, Cliff; Liu, Richard T; Nadorff, Michael R

2016-09-01

A popular way to attempt to discern causality in clinical psychology is through mediation analysis. However, mediation analysis is sometimes applied to research questions in clinical psychology when inferring causality is impossible. This practice may soon increase with new, readily available, and easy-to-use statistical advances. Thus, we here provide a heuristic to remind clinical psychological scientists of the assumptions of mediation analyses. We describe recent statistical advances and unpack assumptions of causality in mediation, underscoring the importance of time in understanding mediational hypotheses and analyses in clinical psychology. Example analyses demonstrate that statistical mediation can occur despite theoretical mediation being improbable. We propose a delineation of mediational effects derived from cross-sectional designs into the terms temporal and atemporal associations to emphasize time in conceptualizing process models in clinical psychology. The general implications for mediational hypotheses and the temporal frameworks from within which they may be drawn are discussed. © 2016 Wiley Periodicals, Inc.

APOC3 Loss-of-Function Mutations, Remnant Cholesterol, Low-Density Lipoprotein Cholesterol, and Cardiovascular Risk: Mediation- and Meta-Analyses of 137 895 Individuals.

PubMed

Wulff, Anders B; Nordestgaard, Børge G; Tybjærg-Hansen, Anne

2018-03-01

Loss-of-function mutations in APOC3 associate with low remnant cholesterol levels and low risk of ischemic vascular disease (IVD). Because some studies show an additional association with low levels of low-density lipoprotein cholesterol (LDL-C), low LDL-C may explain the low risk of IVD in APOC3 loss-of-function heterozygotes. We tested to what extent the low risk of IVD in APOC3 loss-of-function heterozygotes is mediated by low plasma remnant cholesterol and LDL-C. In APOC3 loss-of-function heterozygotes versus noncarriers, we first determined remnant cholesterol and LDL-C levels in meta-analyses of 137 895 individuals. Second, we determined whether the association with LDL-C was masked by lipid-lowering therapy. Finally, using mediation analysis, we determined the fraction of the low risk of IVD and ischemic heart disease mediated by remnant cholesterol and LDL-C. In meta-analyses, remnant cholesterol was 43% lower (95% confidence interval, 40%-47%), and LDL-C was 4% lower (1%-6%) in loss-of-function heterozygotes (n=776) versus noncarriers. In the general population, LDL-C was 3% lower in loss-of-function heterozygotes versus noncarriers, 4% lower when correcting for lipid-lowering therapy, and 3% lower in untreated individuals ( P values, 0.06-0.008). Remnant cholesterol mediated 37% of the observed 41% lower risk of IVD and 54% of the observed 36% lower risk of ischemic heart disease; corresponding values mediated by LDL-C were 1% and 2%. The low risk of IVD observed in APOC3 loss-of-function heterozygotes is mainly mediated by the associated low remnant cholesterol and not by low LDL-C. Furthermore, the contribution of LDL-C to IVD risk was not masked by lipid-lowering therapy. This suggests APOC3 and remnant cholesterol as important new targets for reducing cardiovascular risk. © 2018 American Heart Association, Inc.

Idiosyncratic deals and employee outcomes: the mediating roles of social exchange and self-enhancement and the moderating role of individualism.

PubMed

Liu, Jun; Lee, Cynthia; Hui, Chun; Kwan, Ho Kwong; Wu, Long-Zeng

2013-09-01

The majority of studies on idiosyncratic employment arrangements ("i-deals") are based on social exchange theory. The authors suggest that self-enhancement theory, in addition to social exchange, can be used to explain the effects of i-deals. Using a multisource sample including 230 employees and 102 supervisors from 2 Chinese companies, the authors adopt a 3-wave lagged design to examine the mediating roles of social exchange and self-enhancement and the moderating role of individualism in the relationships between i-deals and employee outcomes, as indicated by proactive behaviors and affective commitment. The results of bootstrapping analyses confirm the mediating effects of social exchange and self-enhancement. In addition, employees with high levels of individualism are more receptive to self-enhancement effects; in contrast, employees with low levels of individualism are more receptive to social exchange effects. PsycINFO Database Record (c) 2013 APA, all rights reserved

Theory of mind deficits partly mediate impaired social decision-making in schizophrenia.

PubMed

Yang, Liuqing; Li, Peifu; Mao, Haiying; Wang, Huiling; Shu, Chang; Bliksted, Vibeke; Zhou, Yuan

2017-05-05

Using paradigms from game theory, researchers have reported abnormal decision-making in social context in patients with schizophrenia. However, less is known about the underpinnings of the impairment. This study aimed to test whether theory of mind (ToM) deficits and/or neurocognitive dysfunctions mediate impaired social decision-making in patients with schizophrenia. We compared thirty-five patients with schizophrenia to thirty-eight matched healthy controls with regard to social decision-making using the mini Ultimatum Game (mini UG), a paradigm from game theory. Additionally, we assessed ToM using the Theory of Mind Picture Stories Task, a mental state attribution task, and assessed neurocognition using the Brief Assessment of Cognition in Schizophrenia. Mediation analyses were performed on the data. In contrast to the behavioral pattern of healthy controls in the mini UG, the patients with schizophrenia significantly accepted more disadvantageous offers and rejected more advantageous offers, and showed reduced sensitivity to the fairness-related context changes in the mini UG. Impaired ToM and neurocognition were also found in the patients. Mediation analyses indicated that ToM but not neurocognition partially mediated the group differences on the disadvantageous and advantageous offers in the mini UG. Patients with schizophrenia exhibited impaired social decision-making. This impairment can be partly explained by their ToM deficits rather than neurocognitive deficits. However, the exact nature of the ToM deficits that mediate impaired social decision-making needs to be identified in future.

Interpersonal and intrapersonal factors as parallel independent mediators in the association between internalized HIV stigma and ART adherence

PubMed Central

Seghatol-Eslami, Victoria C.; Dark, Heather; Raper, James L.; Mugavero, Michael J.; Turan, Janet M.; Turan, Bulent

2016-01-01

Introduction People living with HIV (PLWH) need to adhere to antiretroviral therapy (ART) to achieve optimal health. One reason for ART non-adherence is HIV-related stigma. Objectives We aimed to examine whether HIV treatment self-efficacy (an intrapersonal mechanism) mediates the stigma – adherence association. We also examined whether self-efficacy and the concern about being seen while taking HIV medication (an interpersonal mechanism) are parallel mediators independent of each other. Methods 180 PLWH self-reported internalized HIV stigma, ART adherence, HIV treatment self-efficacy, and concerns about being seen while taking HIV medication. We calculated bias-corrected 95% confidence intervals (CIs) for indirect effects using bootstrapping to conduct mediation analyses. Results Adherence self-efficacy mediated the relationship between internalized stigma and ART adherence. Additionally, self-efficacy and concern about being seen while taking HIV medication uniquely mediated and explained almost all of the stigma – adherence association in independent paths (parallel mediation). Conclusion These results can inform intervention strategies to promote ART adherence. PMID:27926668

Mother–Adolescent Conflict as a Mediator Between Adolescent Problem Behaviors and Maternal Psychological Control

PubMed Central

Steeger, Christine M.; Gondoli, Dawn M.

2014-01-01

This study examined mother–adolescent conflict as a mediator of longitudinal reciprocal relations between adolescent aggression and depressive symptoms and maternal psychological control. Motivated by family systems theory and the transactions that occur between individual and dyadic levels of the family system, we examined the connections among these variables during a developmental period when children and parents experience significant psychosocial changes. Three years of self-report data were collected from 168 mother–adolescent dyads, beginning when the adolescents (55.4% girls) were in 6th grade. Models were tested using longitudinal path analysis. Results indicated that the connection between adolescent aggression (and depressive symptoms) and maternal psychological control was best characterized as adolescent-driven, indirect, and mediated by mother–adolescent conflict; there were no indications of parent-driven indirect effects. That is, prior adolescent aggression and depressive symptoms were associated with increased conflict. In turn, conflict was associated with increased psychological control. Within our mediation models, reciprocal direct effects between both problem behaviors and conflict and between conflict and psychological control were also found. Additionally, exploratory analyses regarding the role of adolescent gender as a moderator of variable relations were conducted. These analyses revealed no gender-related patterns of moderation, whether moderated mediation or specific path tests for moderation were considered. This study corroborates prior research finding support for child effects on parenting behaviors during early adolescence. PMID:22612432

The Influence of Treatment Attendance on Subsequent Aggression among Severely Mentally Ill Substance Abusers

PubMed Central

Zhuo, Yue; Bradizza, Clara M.; Maisto, Stephen A.

2014-01-01

The interrelationships between severe mental illness, substance use, and aggression are of longstanding importance with implications for community treatment programs, treatment research and public policy. Through the analysis of longitudinal data collected from 278 patients over a 6-month period following admission to an outpatient dual diagnosis treatment program, this study examined the association between dual diagnosis treatment attendance and subsequent aggression among individuals diagnosed with both a severe mental illness and a substance use disorder. We also tested substance use and psychiatric symptoms as mediators of this treatment-aggression relationship. The results of structural equation modeling analyses indicated that dual diagnosis treatment was associated with lower levels of subsequent aggression. Mediational analyses indicated that greater treatment involvement was associated with reduced substance use, which was associated with lower levels of aggression; thus, substance use was found to mediate the relationship between dual diagnosis treatment and aggression. Surprisingly, severity of psychiatric symptoms did not predict later aggression. These findings suggest that targeting substance use reduction in treatment may have the additional benefit of reducing the risk of later aggression among dual diagnosis patients. PMID:25124261

Is political conservatism synonymous with authoritarianism?

PubMed

Crowson, H Michael; Thoma, Stephen J; Hestevold, Nita

2005-10-01

The authors performed 2 studies that tested the distinction between conservative political ideology and right-wing authoritarianism (RWA). Across these studies, moderate relationships emerged between RWA and our measures of cognitive rigidity, whereas the relationship between rigidity and mainstream conservative ideology was not as strong. The authors used partial-correlation and path analyses to assess the possibility that RWA mediates the relationship between (a) cognitive rigidity and (b) mainstream conservative attitudes and self-identified conservatism. The results indicated that conservatism is not synonymous with RWA. Additionally, RWA appeared to partially mediate the relationship between cognitive rigidity and mainstream conservatism.

Density- and trait-mediated effects of a parasite and a predator in a tri-trophic food web

PubMed Central

Banerji, Aabir; Duncan, Alison B; Griffin, Joanne S; Humphries, Stuart; Petchey, Owen L; Kaltz, Oliver

2015-01-01

1. Despite growing interest in ecological consequences of parasitism in food webs, relatively little is known about effects of parasites on long-term population dynamics of non-host species or about whether such effects are density or trait mediated. 2. We studied a tri-trophic food chain comprised of (i) a bacterial basal resource (Serratia fonticola), (ii) an intermediate consumer (Paramecium caudatum), (iii) a top predator (Didinium nasutum) and (iv) a parasite of the intermediate consumer (Holospora undulata). A fully factorial experimental manipulation of predator and parasite presence/absence was combined with analyses of population dynamics, modelling and analyses of host (Paramecium) morphology and behaviour. 3. Predation and parasitism each reduced the abundance of the intermediate consumer (Paramecium), and parasitism indirectly reduced the abundance of the basal resource (Serratia). However, in combination, predation and parasitism had non-additive effects on the abundance of the intermediate consumer, as well as on that of the basal resource. In both cases, the negative effect of parasitism seemed to be effaced by predation. 4. Infection of the intermediate consumer reduced predator abundance. Modelling and additional experimentation revealed that this was most likely due to parasite reduction of intermediate host abundance (a density-mediated effect), as opposed to changes in predator functional or numerical response. 5. Parasitism altered morphological and behavioural traits, by reducing host cell length and increasing the swimming speed of cells with moderate parasite loads. Additional tests showed no significant difference in Didinium feeding rate on infected and uninfected hosts, suggesting that the combination of these modifications does not affect host vulnerability to predation. However, estimated rates of encounter with Serratia based on these modifications were higher for infected Paramecium than for uninfected Paramecium. 6. A mixture of density-mediated and trait-mediated indirect effects of parasitism on non-host species creates rich and complex possibilities for effects of parasites in food webs that should be included in assessments of possible impacts of parasite eradication or introduction. PMID:25382389

Religiosity and decreased risk of substance use disorders: is the effect mediated by social support or mental health status?

PubMed Central

Harris, Katherine M.; Koenig, Harold G.; Han, Xiaotong; Sullivan, Greer; Mattox, Rhonda; Tang, Lingqi

2009-01-01

Objective The negative association between religiosity (religious beliefs and church attendance) and the likelihood of substance use disorders is well established, but the mechanism(s) remain poorly understood. We investigated whether this association was mediated by social support or mental health status. Method We utilized cross-sectional data from the 2002 National Survey on Drug Use and Health (n = 36,370). We first used logistic regression to regress any alcohol use in the past year on sociodemographic and religiosity variables. Then, among individuals who drank in the past year, we regressed past year alcohol abuse/dependence on sociodemographic and religiosity variables. To investigate whether social support mediated the association between religiosity and alcohol use and alcohol abuse/dependence we repeated the above models, adding the social support variables. To the extent that these added predictors modified the magnitude of the effect of the religiosity variables, we interpreted social support as a possible mediator. We also formally tested for mediation using path analysis. We investigated the possible mediating role of mental health status analogously. Parallel sets of analyses were conducted for any drug use, and drug abuse/dependence among those using any drugs as the dependent variables. Results The addition of social support and mental health status variables to logistic regression models had little effect on the magnitude of the religiosity coefficients in any of the models. While some of the tests of mediation were significant in the path analyses, the results were not always in the expected direction, and the magnitude of the effects was small. Conclusions The association between religiosity and decreased likelihood of a substance use disorder does not appear to be substantively mediated by either social support or mental health status. PMID:19714282

Persistence of Animal and Human Glycopeptide-Resistant Enterococci on Two Norwegian Poultry Farms Formerly Exposed to Avoparcin Is Associated with a Widespread Plasmid-Mediated vanA Element within a Polyclonal Enterococcus faecium Population

PubMed Central

Johnsen, P. J.; Østerhus, J. I.; Sletvold, H.; Sørum, M.; Kruse, H.; Nielsen, K.; Simonsen, G. S.; Sundsfjord, A.

2005-01-01

The evolutionary processes responsible for the long-term persistence of glycopeptide-resistant Enterococcus faecium (GREF) in nonselective environments were addressed by genetic analyses of E. faecium populations in animals and humans on two Norwegian poultry farms that were previously exposed to avoparcin. A total of 222 fecal GREF (n = 136) and glycopeptide-susceptible (n = 86) E. faecium (GSEF) isolates were obtained from farmers and poultry on three separate occasions in 1998 and 1999. Pulsed-field gel electrophoresis (PFGE) and plasmid DNA analyses discerned 22 GREF and 32 GSEF PFGE types within shifting polyclonal animal and human E. faecium populations and indicated the presence of transferable plasmid-mediated vanA resistance, respectively. Examples of dominant, persistent GREF PFGE types supported the notion that environmentally well-adapted GREF types may counteract the reversal of resistance. PFGE analyses, sequencing of the purK housekeeping gene, and partial typing of vanA-containing Tn1546 suggested a common animal and human reservoir of glycopeptide resistance. Inverse PCR amplification and sequence analyses targeting the right end of the Tn1546-plasmid junction fragment strongly indicated the presence of a common single Tn1546-plasmid-mediated element in 20 of 22 GREF PFGE types. This observation was further strengthened by vanY-vanZ hybridization analyses of plasmid DNAs as well as the finding of a physical linkage between Tn1546 and a putative postsegregation killing system for seven GREF PFGE types. In conclusion, our observations suggest that the molecular unit of persistence of glycopeptide resistance is a common mobile plasmid-mediated vanA-containing element within a polyclonal GREF population that changes over time. In addition, we propose that “plasmid addiction systems” may contribute to the persistence of GREF in nonselective environments. PMID:15640183

Mediation analysis: a retrospective snapshot of practice and more recent directions.

PubMed

Gelfand, Lois A; Mensinger, Janell L; Tenhave, Thomas

2009-04-01

R. Baron and D. A. Kenny's (1986) paper introducing mediation analysis has been cited over 9,000 times, but concerns have been expressed about how this method is used. The authors review past and recent methodological literature and make recommendations for how to address 3 main issues: association, temporal order, and the no omitted variables assumption. The authors briefly visit the topics of reliability and the confirmatory-exploratory distinction. In addition, to provide a sense of the extent to which the earlier literature had been absorbed into practice, the authors examined a sample of 50 articles from 2002 citing R. Baron and D. A. Kenny and containing at least 1 mediation analysis via ordinary least squares regression. A substantial proportion of these articles included problematic reporting; as of 2002, there appeared to be room for improvement in conducting such mediation analyses. Future literature reviews will demonstrate the extent to which the situation has improved.

Multiple Losses: The Psychological and Economic Well-Being of Survivors of Intimate Partner Violence.

PubMed

Sauber, Elizabeth W; O'Brien, Karen M

2017-05-01

This study advanced knowledge regarding the mechanisms through which intimate partner violence relates to psychological and financial distress with a sample of diverse low-income women. Data were collected from 147 female domestic violence survivors who were abused by a male partner within the past 6 months. Three hierarchical regression analyses revealed that psychological, physical, and economic abuse were predictive of posttraumatic stress, depression, and economic self-sufficiency among survivors. Guided by the Conservation of Resources Theory, the loss of financial, work, and interpersonal resources also predicted these three outcomes, above and beyond abuse experiences (i.e., economically controlling behaviors, economic sabotage, and interpersonal resource loss were unique predictors). In addition, bootstrap mediation analyses showed that interpersonal resource loss partially mediated the relationship between psychological abuse and mental health outcomes. Together, these findings can be used to inform future interventions to promote the financial and psychological well-being of survivors.

Structural Equation Model of Smartphone Addiction Based on Adult Attachment Theory: Mediating Effects of Loneliness and Depression.

PubMed

Kim, EunYoung; Cho, Inhyo; Kim, Eun Joo

2017-06-01

This study investigated the mediating effects of loneliness and depression on the relationship between adult attachment and smartphone addiction in university students. A total of 200 university students participated in this study. The data was analysed using descriptive statistics, correlation analysis, and structural equation modeling. There were significant positive relationships between attachment anxiety, loneliness, depression, and smartphone addiction. However, attachment anxiety was not significantly correlated with smartphone addiction. The results also showed that loneliness did not directly mediate between attachment anxiety and smartphone addiction. In addition, loneliness and depression serially mediated between attachment anxiety and smartphone addiction. The results suggest there are mediating effects of loneliness and depression in the relationship between attachment anxiety and smartphone addiction. The hypothesized model was found to be a suitable model for predicting smartphone addiction among university students. Future study is required to find a causal path to prevent smartphone addiction among university students. Copyright © 2017. Published by Elsevier B.V.

DNA methylation as a mediator of the association between prenatal adversity and risk factors for metabolic disease in adulthood

PubMed Central

Tobi, Elmar W.; Slieker, Roderick C.; Luijk, René; Dekkers, Koen F.; Stein, Aryeh D.; Xu, Kate M.; Slagboom, P. Eline; van Zwet, Erik W.; Lumey, L. H.; Heijmans, Bastiaan T.

2018-01-01

Although it is assumed that epigenetic mechanisms, such as changes in DNA methylation (DNAm), underlie the relationship between adverse intrauterine conditions and adult metabolic health, evidence from human studies remains scarce. Therefore, we evaluated whether DNAm in whole blood mediated the association between prenatal famine exposure and metabolic health in 422 individuals exposed to famine in utero and 463 (sibling) controls. We implemented a two-step analysis, namely, a genome-wide exploration across 342,596 cytosine-phosphate-guanine dinucleotides (CpGs) for potential mediators of the association between prenatal famine exposure and adult body mass index (BMI), serum triglycerides (TG), or glucose concentrations, which was followed by formal mediation analysis. DNAm mediated the association of prenatal famine exposure with adult BMI and TG but not with glucose. DNAm at PIM3 (cg09349128), a gene involved in energy metabolism, mediated 13.4% [95% confidence interval (CI), 5 to 28%] of the association between famine exposure and BMI. DNAm at six CpGs, including TXNIP (cg19693031), influencing β cell function, and ABCG1 (cg07397296), affecting lipid metabolism, together mediated 80% (95% CI, 38.5 to 100%) of the association between famine exposure and TG. Analyses restricted to those exposed to famine during early gestation identified additional CpGs mediating the relationship with TG near PFKFB3 (glycolysis) and METTL8 (adipogenesis). DNAm at the CpGs involved was associated with gene expression in an external data set and correlated with DNAm levels in fat depots in additional postmortem data. Our data are consistent with the hypothesis that epigenetic mechanisms mediate the influence of transient adverse environmental factors in early life on long-term metabolic health. The specific mechanism awaits elucidation. PMID:29399631

Mediational Analyses of the Effects of Responsive Teaching on the Developmental Functioning of Preschool Children with Disabilities

ERIC Educational Resources Information Center

Karaaslan, Ozcan; Mahoney, Gerald

2015-01-01

Mediational analyses were conducted with data from two small randomized control trials of the Responsive Teaching (RT) parent-mediated developmental intervention which used nearly identical intervention and control procedures. The purpose of these analyses was to determine whether or how the changes in maternal responsiveness and children's…

The Impact of Homophobia and HIV Stigma on HIV Testing Uptake Among Chinese Men Who Have Sex With Men: a Mediation Analysis.

PubMed

Wei, Chongyi; Cheung, Doug H; Yan, Hongjing; Li, Jianjun; Shi, Ling-en; Raymond, Henry F

2016-01-01

Gay and HIV-related stigma and discrimination are major barriers to accessing HIV prevention services among Men Who Have Sex with Men (MSM) worldwide. We aimed to identify modifiable factors that mediate the relationships between gay and HIV-related stigma and discrimination and HIV testing uptake among Chinese MSM. We conducted a cross-sectional survey study of 523 HIV-uninfected or unknown HIV status MSM in Jiangsu Province, China between November 2013 and January 2014. Multivariable analyses were conducted to examine the associations among experienced homophobia, HIV stigma, and recent HIV testing. Causal mediation parametric analyses were conducted to assess whether depression and social norms mediated hypothesized associations. Stronger subjective norms toward testing was associated with higher odds of recent HIV testing (adjusted odds ratio [AOR]: 1.10, 95% confidence interval [CI]: 1.01 to 1.21), whereas increasing levels of depression and HIV stigma were both associated with lower odds of recent testing (AOR: 0.96, 95% CI: 0.92 to 0.99; and AOR: 0.91, 95% CI: 0.84 to 0.99, respectively). There was an indirect relationship (natural indirect effect [NIE]) of experienced homophobia on recent testing (ORNIE: 0.96, 95% CI: 0.93 to 0.98) mediated (35.0%) through depression. Furthermore, there was an indirect relationship of HIV stigma on recent testing (ORNIE: 0.98, 95% CI: 0.95 to 0.99) mediated (19.2%) through subjective norms. Depression and social norms are important mediators of HIV testing uptake among stigmatized Chinese MSM. Therefore, in addition to advocacy efforts and policies that address social-level stigma and discrimination, HIV prevention programs should also address mental health issues and incorporate community-based approaches to changing social norms toward HIV testing.

The Impact of Homophobia and HIV Stigma on HIV Testing Uptake among Chinese Men Who Have Sex with Men: A Mediation Analysis

PubMed Central

Wei, Chongyi; Cheung, Doug H.; Yan, Hongjing; Li, Jianjun; Shi, Ling-en; Raymond, H. Fisher

2015-01-01

BACKGROUND Gay and HIV-related stigma and discrimination are major barriers to accessing HIV prevention services among MSM worldwide. We aimed to identify modifiable factors that mediate the relationships between gay and HIV-related stigma and discrimination and HIV testing uptake among Chinese MSM. METHODS We conducted a cross-sectional survey study of 523 HIV-uninfected or unknown MSM in Jiangsu Province, China between November 2013 and January 2014. Multivariable analyses were conducted to examine the associations among experienced homophobia, HIV stigma, and recent HIV testing. Causal mediation parametric analyses were conducted to assess whether depression and social norms mediated hypothesized associations. RESULTS Stronger subjective norms toward testing was associated with higher odds of recent HIV testing (AOR: 1.10, 95% CI: 1.01, 1.21) while increasing levels of depression and HIV stigma were both associated with lower odds of recent testing (AOR: 0.96, 95% CI: 0.92, 0.99; and AOR: 0.91, 95% CI: 0.84, 0.99, respectively). There was an indirect relationship (natural indirect effect) of experienced homophobia on recent testing (ORNIE: 0.96, 95% CI: 0.93, 0.98) mediated (35.0%) through depression. Furthermore, there was an indirect relationship of HIV stigma on recent testing (ORNIE: 0.98, 95% CI: 0.95, 0.99) mediated (19.2%) through subjective norms. CONCLUSIONS Depression and social norms are important mediators of HIV testing uptake among stigmatized Chinese MSM. Therefore, in addition to advocacy efforts and policies that address social-level stigma and discrimination, HIV prevention programs should also address mental health issues and incorporate community-based approaches to changing social norms toward HIV testing. PMID:26334742

Mother-adolescent conflict as a mediator between adolescent problem behaviors and maternal psychological control.

PubMed

Steeger, Christine M; Gondoli, Dawn M

2013-04-01

This study examined mother-adolescent conflict as a mediator of longitudinal reciprocal relations between adolescent aggression and depressive symptoms and maternal psychological control. Motivated by family systems theory and the transactions that occur between individual and dyadic levels of the family system, we examined the connections among these variables during a developmental period when children and parents experience significant psychosocial changes. Three years of self-report data were collected from 168 mother-adolescent dyads, beginning when the adolescents (55.4% girls) were in 6th grade. Models were tested using longitudinal path analysis. Results indicated that the connection between adolescent aggression (and depressive symptoms) and maternal psychological control was best characterized as adolescent-driven, indirect, and mediated by mother-adolescent conflict; there were no indications of parent-driven indirect effects. That is, prior adolescent aggression and depressive symptoms were associated with increased conflict. In turn, conflict was associated with increased psychological control. Within our mediation models, reciprocal direct effects between both problem behaviors and conflict and between conflict and psychological control were also found. Additionally, exploratory analyses regarding the role of adolescent gender as a moderator of variable relations were conducted. These analyses revealed no gender-related patterns of moderation, whether moderated mediation or specific path tests for moderation were considered. This study corroborates prior research finding support for child effects on parenting behaviors during early adolescence. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Does Emotion Dysregulation Mediate the Association Between Sluggish Cognitive Tempo and College Students' Social Impairment?

PubMed

Flannery, Andrew J; Becker, Stephen P; Luebbe, Aaron M

2016-09-01

Studies demonstrate an association between sluggish cognitive tempo (SCT) and social impairment, although no studies have tested possible mechanisms of this association. This study aimed to (a) examine SCT in relation to college students' social functioning; (b) test if SCT is significantly associated with emotion dysregulation beyond depressive, anxious, and ADHD symptoms; and (c) test if emotion dysregulation mediates the association between SCT symptoms and social impairment. College students (N = 158) completed measures of psychopathology symptoms, emotion dysregulation, and social functioning. Participants with elevated SCT (12%) had higher ADHD, depressive, and anxious symptoms in addition to poorer emotion regulation and social adjustment than participants without elevated SCT. Above and beyond other psychopathologies, SCT was significantly associated with social impairment but not general interpersonal functioning. SCT was also associated with emotion dysregulation, even after accounting for the expectedly strong association between depression and emotion dysregulation. Further analyses supported emotion dysregulation as a mediator of the association between SCT and social impairment. These findings are important for theoretical models of SCT and underscore the need for additional, longitudinal research. © The Author(s) 2014.

One-Year Outcomes and Mediators of a Brief Intervention for Drug Abusing Adolescents

PubMed Central

Winters, Ken C.; Lee, Susanne; Botzet, Andria; Fahnhorst, Tamara; Nicholson, Ali

2014-01-01

Two manually-guided brief interventions were evaluated with a randomized controlled trial. Adolescents (aged 13-17 years) suspected of abusing alcohol and other drugs and their parent were randomly assigned to receive either a 2-session adolescent only (BI-A), 2-session adolescent and additional parent session (BI-AP), or assessment only control condition (CON). Adolescents were identified in a school setting and the intervention was delivered by trained counselors. Outcome analyses (N=284; 90% of those enrolled) of relative change (from intake to 12-months) and absolute status (at 12-months) revealed a general pattern of reductions in drug use behaviors, particularly with the cannabis outcome measures, in both active conditions (BI-A and BI-AP). Students in the control condition showed worse outcome compared to the BI-A and BI-AP groups. Among the four mediating variables measured at 6-months, use of additional services, motivation to change and parenting practices had significant influences on 12-month outcome; problem solving skills approached significance as a mediator. The potential value of a brief intervention for drug abusing adolescents is discussed. PMID:24955669

Risk factors and mediating pathways of loneliness and social support in community-dwelling older adults.

PubMed

Schnittger, Rebecca I B; Wherton, Joseph; Prendergast, David; Lawlor, Brian A

2012-01-01

To develop biopsychosocial models of loneliness and social support thereby identifying their key risk factors in an Irish sample of community-dwelling older adults. Additionally, to investigate indirect effects of social support on loneliness through mediating risk factors. A total of 579 participants (400 females; 179 males) were given a battery of biopsychosocial assessments with the primary measures being the De Jong Gierveld Loneliness Scale and the Lubben Social Network Scale along with a broad range of secondary measures. Bivariate correlation analyses identified items to be included in separate psychosocial, cognitive, biological and demographic multiple regression analyses. The resulting model items were then entered into further multiple regression analyses to obtain overall models. Following this, bootstrapping mediation analyses was conducted to examine indirect effects of social support on the subtypes (emotional and social) of loneliness. The overall model for (1) emotional loneliness included depression, neuroticism, perceived stress, living alone and accommodation type, (2) social loneliness included neuroticism, perceived stress, animal naming and number of grandchildren and (3) social support included extraversion, executive functioning (Trail Making Test B-time), history of falls, age and whether the participant drives or not. Social support influenced emotional loneliness predominantly through indirect means, while its effect on social loneliness was more direct. These results characterise the biopsychosocial risk factors of emotional loneliness, social loneliness and social support and identify key pathways by which social support influences emotional and social loneliness. These findings highlight issues with the potential for consideration in the development of targeted interventions.

Design and synthesis of inositolphosphoglycan putative insulin mediators.

PubMed

López-Prados, Javier; Cuevas, Félix; Reichardt, Niels-Christian; de Paz, José-Luis; Morales, Ezequiel Q; Martín-Lomas, Manuel

2005-03-07

The binding modes of a series of molecules, containing the glucosamine (1-->6) myo-inositol structural motif, into the ATP binding site of the catalytic subunit of cAMP-dependent protein kinase (PKA) have been analysed using molecular docking. These calculations predict that the presence of a phosphate group at the non-reducing end in pseudodisaccharide and pseudotrisaccharide structures properly orientate the molecule into the binding site and that pseudotrisaccharide structures present the best shape complementarity. Therefore, pseudodisaccharides and pseudotrisaccharides have been synthesised from common intermediates using effective synthetic strategies. On the basis of this synthetic chemistry, the feasibility of constructing small pseudotrisaccharide libraries on solid-phase using the same intermediates has been explored. The results from the biological evaluation of these molecules provide additional support to an insulin-mediated signalling system which involves the intermediacy of inositolphosphoglycans as putative insulin mediators.

Domain General Mediators of the Relation between Kindergarten Number Sense and First-Grade Mathematics Achievement

PubMed Central

Hassinger-Das, Brenna; Jordan, Nancy C.; Glutting, Joseph; Irwin, Casey; Dyson, Nancy

2013-01-01

Domain general skills that mediate the relation between kindergarten number sense and first-grade mathematics skills were investigated. Participants were 107 children who displayed low number sense in the fall of kindergarten. Controlling for background variables, multiple regression analyses showed that attention problems and executive functioning both were unique predictors of mathematics outcomes. Attention problems were more important for predicting first-grade calculation performance while executive functioning was more important for predicting first-grade performance on applied problems. Moreover, both executive functioning and attention problems were unique partial mediators of the relationship between kindergarten and first-grade mathematics skills. The results provide empirical support for developing interventions that target executive functioning and attention problems in addition to instruction in number skills for kindergartners with initial low number sense. PMID:24237789

Domain-general mediators of the relation between kindergarten number sense and first-grade mathematics achievement.

PubMed

Hassinger-Das, Brenna; Jordan, Nancy C; Glutting, Joseph; Irwin, Casey; Dyson, Nancy

2014-02-01

Domain-general skills that mediate the relation between kindergarten number sense and first-grade mathematics skills were investigated. Participants were 107 children who displayed low number sense in the fall of kindergarten. Controlling for background variables, multiple regression analyses showed that both attention problems and executive functioning were unique predictors of mathematics outcomes. Attention problems were more important for predicting first-grade calculation performance, whereas executive functioning was more important for predicting first-grade performance on applied problems. Moreover, both executive functioning and attention problems were unique partial mediators of the relationship between kindergarten and first-grade mathematics skills. The results provide empirical support for developing interventions that target executive functioning and attention problems in addition to instruction in number skills for kindergartners with initial low number sense. Copyright © 2013 Elsevier Inc. All rights reserved.

SPSS and SAS programming for the testing of mediation models.

PubMed

Dudley, William N; Benuzillo, Jose G; Carrico, Mineh S

2004-01-01

Mediation modeling can explain the nature of the relation among three or more variables. In addition, it can be used to show how a variable mediates the relation between levels of intervention and outcome. The Sobel test, developed in 1990, provides a statistical method for determining the influence of a mediator on an intervention or outcome. Although interactive Web-based and stand-alone methods exist for computing the Sobel test, SPSS and SAS programs that automatically run the required regression analyses and computations increase the accessibility of mediation modeling to nursing researchers. To illustrate the utility of the Sobel test and to make this programming available to the Nursing Research audience in both SAS and SPSS. The history, logic, and technical aspects of mediation testing are introduced. The syntax files sobel.sps and sobel.sas, created to automate the computation of the regression analysis and test statistic, are available from the corresponding author. The reported programming allows the user to complete mediation testing with the user's own data in a single-step fashion. A technical manual included with the programming provides instruction on program use and interpretation of the output. Mediation modeling is a useful tool for describing the relation between three or more variables. Programming and manuals for using this model are made available.

Differentiation of Xylella fastidiosa Strains via Multilocus Sequence Analysis of Environmentally Mediated Genes (MLSA-E)

PubMed Central

Parker, Jennifer K.; Havird, Justin C.

2012-01-01

Isolates of the plant pathogen Xylella fastidiosa are genetically very similar, but studies on their biological traits have indicated differences in virulence and infection symptomatology. Taxonomic analyses have identified several subspecies, and phylogenetic analyses of housekeeping genes have shown broad host-based genetic differences; however, results are still inconclusive for genetic differentiation of isolates within subspecies. This study employs multilocus sequence analysis of environmentally mediated genes (MLSA-E; genes influenced by environmental factors) to investigate X. fastidiosa relationships and differentiate isolates with low genetic variability. Potential environmentally mediated genes, including host colonization and survival genes related to infection establishment, were identified a priori. The ratio of the rate of nonsynonymous substitutions to the rate of synonymous substitutions (dN/dS) was calculated to select genes that may be under increased positive selection compared to previously studied housekeeping genes. Nine genes were sequenced from 54 X. fastidiosa isolates infecting different host plants across the United States. Results of maximum likelihood (ML) and Bayesian phylogenetic (BP) analyses are in agreement with known X. fastidiosa subspecies clades but show novel within-subspecies differentiation, including geographic differentiation, and provide additional information regarding host-based isolate variation and specificity. dN/dS ratios of environmentally mediated genes, though <1 due to high sequence similarity, are significantly greater than housekeeping gene dN/dS ratios and correlate with increased sequence variability. MLSA-E can more precisely resolve relationships between closely related bacterial strains with low genetic variability, such as X. fastidiosa isolates. Discovering the genetic relationships between X. fastidiosa isolates will provide new insights into the epidemiology of populations of X. fastidiosa, allowing improved disease management in economically important crops. PMID:22194287

Differentiation of Xylella fastidiosa strains via multilocus sequence analysis of environmentally mediated genes (MLSA-E).

PubMed

Parker, Jennifer K; Havird, Justin C; De La Fuente, Leonardo

2012-03-01

Isolates of the plant pathogen Xylella fastidiosa are genetically very similar, but studies on their biological traits have indicated differences in virulence and infection symptomatology. Taxonomic analyses have identified several subspecies, and phylogenetic analyses of housekeeping genes have shown broad host-based genetic differences; however, results are still inconclusive for genetic differentiation of isolates within subspecies. This study employs multilocus sequence analysis of environmentally mediated genes (MLSA-E; genes influenced by environmental factors) to investigate X. fastidiosa relationships and differentiate isolates with low genetic variability. Potential environmentally mediated genes, including host colonization and survival genes related to infection establishment, were identified a priori. The ratio of the rate of nonsynonymous substitutions to the rate of synonymous substitutions (dN/dS) was calculated to select genes that may be under increased positive selection compared to previously studied housekeeping genes. Nine genes were sequenced from 54 X. fastidiosa isolates infecting different host plants across the United States. Results of maximum likelihood (ML) and Bayesian phylogenetic (BP) analyses are in agreement with known X. fastidiosa subspecies clades but show novel within-subspecies differentiation, including geographic differentiation, and provide additional information regarding host-based isolate variation and specificity. dN/dS ratios of environmentally mediated genes, though <1 due to high sequence similarity, are significantly greater than housekeeping gene dN/dS ratios and correlate with increased sequence variability. MLSA-E can more precisely resolve relationships between closely related bacterial strains with low genetic variability, such as X. fastidiosa isolates. Discovering the genetic relationships between X. fastidiosa isolates will provide new insights into the epidemiology of populations of X. fastidiosa, allowing improved disease management in economically important crops.

Incorporating nonlinearity into mediation analyses.

PubMed

Knafl, George J; Knafl, Kathleen A; Grey, Margaret; Dixon, Jane; Deatrick, Janet A; Gallo, Agatha M

2017-03-21

Mediation is an important issue considered in the behavioral, medical, and social sciences. It addresses situations where the effect of a predictor variable X on an outcome variable Y is explained to some extent by an intervening, mediator variable M. Methods for addressing mediation have been available for some time. While these methods continue to undergo refinement, the relationships underlying mediation are commonly treated as linear in the outcome Y, the predictor X, and the mediator M. These relationships, however, can be nonlinear. Methods are needed for assessing when mediation relationships can be treated as linear and for estimating them when they are nonlinear. Existing adaptive regression methods based on fractional polynomials are extended here to address nonlinearity in mediation relationships, but assuming those relationships are monotonic as would be consistent with theories about directionality of such relationships. Example monotonic mediation analyses are provided assessing linear and monotonic mediation of the effect of family functioning (X) on a child's adaptation (Y) to a chronic condition by the difficulty (M) for the family in managing the child's condition. Example moderated monotonic mediation and simulation analyses are also presented. Adaptive methods provide an effective way to incorporate possibly nonlinear monotonicity into mediation relationships.

Social Anxiety and Heavy Situational Drinking: Coping and Conformity Motives as Multiple Mediators

PubMed Central

Terlecki, Meredith A.; Buckner, Julia D.

2014-01-01

Individuals with clinically elevated social anxiety are at greater risk for alcohol use disorder, and the relation between social anxiety and drinking problems is at least partially accounted for by drinking more in negative emotional (e.g., feeling sad or angry) and personal/intimate (e.g., before sexual intercourse) situations. Identification of cognitive/motivational factors related to drinking in these high-risk situations could inform the development of treatment and prevention interventions for these high-risk drinkers. The current study examined the mediating effect of drinking motives on the relationship between social anxiety and drinking these high-risk situations amongst undergraduates (N = 232). Clinically elevated social anxiety was associated with greater coping and conformity motives. Both coping and conformity motives mediated the relation between social anxiety and heavier alcohol consumption in negative emotional and personal/intimate contexts. Multiple mediation analyses indicated that these motives work additively to mediate the social anxiety-drinking situations relationship, such that that heavy situational drinking amongst undergraduates with clinically elevated social anxiety can be jointly attributed to desire to cope with negative affect and to avoid social scrutiny. PMID:25233446

Changes in depression mediate the effects of AA attendance on alcohol use outcomes.

PubMed

Wilcox, Claire E; Tonigan, J Scott

2018-01-01

Depression may contribute to increased drinking in individuals with alcohol use disorder. Although Alcoholics Anonymous (AA) attendance predicts drinking reductions, there is conflicting information regarding the intermediary role played by reductions in depression. We explored whether AA attendance reduces depressive symptoms, the degree to which improvement in depression results in reductions in drinking, and in which subgroups these effects occur. 253 early AA affiliates (63% male) were recruited and assessed at baseline 3, 6, 9, 12, 18, and 24 months. Depression was measured using the Beck Depression Inventory (BDI) and was administered at baseline 3, 6, 12, 18, and 24 months. AA attendance and alcohol use outcomes were obtained with the Form 90. Mediation analyses were performed at early (3, 6, and 9 months) and late (12, 18, and 24 months) follow-up to investigate the degree to which reductions in depression mediated the effect of AA attendance on drinking, controlling for concurrent drinking. In addition, a series of moderated mediation analyses were performed using baseline depression severity as a moderator. At early follow-up, reductions in depression (6 months) mediated the effects of AA attendance (3 months) on later drinking (drinks per drinking day) (9 months) (b = -0.02, boot CI [-0.055, -0.0004]), controlling for drinking at 6 months. Baseline depression severity did not moderate the degree to which BDI mediated the effects of AA attendance on alcohol use (ps > .05). These findings provide further evidence that depression reduction is a mechanism by which AA attendance leads to reductions in alcohol use. Improving depression may help reduce alcohol use in individuals with AUD, and AA attendance may be an effective way to achieve that goal.

Mediating and moderating processes in the relationship between multicultural ideology and attitudes towards immigrants in emerging adults.

PubMed

Musso, Pasquale; Inguglia, Cristiano; Lo Coco, Alida; Albiero, Paolo; Berry, John W

2017-12-01

Few studies examine intercultural relations in emerging adulthood. Framed from the perspective of the Mutual Intercultural Relations in Plural Societies (MIRIPS) project, the current paper examined the mediating role of tolerance and perceived consequences of immigration in the relationship between multicultural ideology and attitudes towards immigrants. Additionally, the moderating role of context was analysed. A two-group structural equation modelling was performed on data collected from 305 Italian emerging adults living both in northern and in southern Italy with different socio-political climates towards immigrants. In both groups, tolerance and perceived consequences of immigration mediated the relationship between multicultural ideology and attitudes towards immigrants. Also, this indirect relationship was significantly higher for the northern than southern Italians. These findings provide provisional evidence of mediating and moderating processes in the relationship between multicultural ideology and attitudes towards immigrants and suggest important implications for practitioners interested in promoting intercultural relations among emerging adults. © 2016 International Union of Psychological Science.

Inspecting the Dangers of Feeling like a Fake: An Empirical Investigation of the Impostor Phenomenon in the World of Work

PubMed Central

Neureiter, Mirjam; Traut-Mattausch, Eva

2016-01-01

To investigate the link between the impostor phenomenon (IP), career self-management (CSM) factors, and work-relevant outcomes, we looked at the IP's impact on career optimism, career adaptability, and knowledge of the job market, as well as on employee- and organizationally-relevant outcomes. We analyzed data from 238 working professionals (57% female) using parallel multiple mediation analyses. The results revealed that the IP was negatively related to all work-relevant outcomes through decreased CSM factors, which were subsequently associated with the outcomes. As hypothesized, employee-relevant subjective outcomes were mediated by optimism and employee-relevant objective (i.e., economic) outcomes by adaptability and knowledge. Additional mediating effects occurred. Regarding organizationally relevant outcomes, adaptability mediated the IP's impact on organizational citizenship behavior. The IP was only indirectly related to continuance commitment through adaptability and to affective commitment through optimism. We discuss the theoretical and practical implications and offer ideas for future research. PMID:27729882

Do nurses who work in a fair organization sleep and perform better and why? Testing potential psychosocial mediators of organizational justice.

PubMed

Hietapakka, Laura; Elovainio, Marko; Heponiemi, Tarja; Presseau, Justin; Eccles, Martin; Aalto, Anna-Mari; Pekkarinen, Laura; Kuokkanen, Liisa; Sinervo, Timo

2013-10-01

We examined whether organizational justice is associated with sleep quality and performance in a population-based sample of 1,729 Finnish registered nurses working full time. In addition, we tested psychological mechanisms mediating the potential association. The results of multivariate linear regression analyses showed higher organizational justice to be associated with fewer sleeping problems (β values range from -.20 to -.11) and higher self-reported performance (β values range from .05 to .35). Furthermore, psychological distress (related to the psychological stress model) and job involvement (related to the psychosocial resource model) mediated the association between organizational justice and sleep. Sleeping problems partly mediated the association between organizational justice and performance. Psychological distress explained 51% to 83% and job involvement explained 10% to 15% of the total effects of justice variables on sleeping problems. The findings provide support for the psychological stress model and offer practical implications for reducing nurses' sleeping problems.

Factors influencing quit attempts among male daily smokers in China✩

PubMed Central

Zhao, Luhua; Song, Yang; Xiao, Lin; Palipudi, Krishna; Asma, Samira

2015-01-01

Background China has the largest population of smokers in the world, yet the quit rate is low. We used data from the 2010 Global Adult Tobacco Survey China to identify factors influencing quit attempts among male Chinese daily smokers. Methods The study sample included 3303 male daily smokers. To determine the factors that were significantly associated with making a quit attempt, we conducted logistic regression analyses. In addition, mediation anal yses were carried out to investigate how the intermediate association among demographics (age, education, urbanicity) and smoking related variables affected making a quit attempt. Results An estimated 11.0% of male daily smokers tried to quit smoking in the 12 months prior to the survey. Logistic regression analysis indicated that younger age (15–24 years), being advised to quit by a health care provider (HCP) in the past 12 months, lower cigarette cost per pack, monthly or less frequent exposure to smoking at home, and awareness of the harms of tobacco use were significantly associated with making a quit attempt. Additional mediation analyses showed that having knowledge of the harm of tobacco, exposure to smoking at home, and having been advised to quit by an HCP were mediators of making a quit attempt for other independent variables. Conclusion Evidence-based tobacco control measures such as conducting educational campaigns on the harms of tobacco use, establishing smoke-free policies at home, and integrating tobacco cessation advice into primary health care services can increase quit attempts and reduce smoking among male Chinese daily smokers. PMID:26441296

Antibody-dependent cellular cytotoxicity (ADCC) activity of a novel anti-PD-L1 antibody avelumab (MSB0010718C) on human tumor cells

PubMed Central

Fantini, Massimo; Heery, Christopher R.; Gulley, James L.; Tsang, Kwong Yok; Schlom, Jeffrey

2015-01-01

Several anti-PD1/PD-L1 monoclonal antibodies (MAb) are currently providing evidence of clinical benefit in subsets of cancer patients. The mode of action of these MAbs is to inhibit PD1 on immune cells interacting with PD-L1 on tumor cells. These MAbs are either designed or engineered to eliminate antibody-dependent cell-mediated cytotoxicity (ADCC), which, however, has been implicated as an important mechanism in several highly effective MAb-mediated cancer therapies. A fully human anti-PD-L1 MAb would potentially be able to block PD-L1/PD1 interactions and also mediate the ADCC lysis of tumor cells. MSB0010718C (designated avelumab) is a fully human IgG1 anti-PD-L1 MAb. The studies reported here demonstrate (a) the ability of avelumab to lyse a range of human tumor cells in the presence of PBMC or NK effectors; (b) IFNγ can enhance tumor cell PD-L1 expression and in some cases enhance ADCC tumor cell lysis; (c) purified NK cells are potent effectors for avelumab; (d) similar levels of avelumab-mediated ADCC lysis of tumor cells are seen using purified NK as effectors from either healthy donors or cancer patients; (e) very low levels of avelumab-mediated lysis are seen using whole PBMCs as targets; this finding complements results seen in analyses of PBMC subsets of patients receiving avelumab; and (f) the addition of IL12 to NK cells greatly enhances avelumab-mediated ADCC. These studies thus provide an additional mode of action for an anti-PD-L1 MAb and support the rationale for further studies to enhance avelumab-mediated ADCC activity. PMID:26014098

Antibody-Dependent Cellular Cytotoxicity Activity of a Novel Anti-PD-L1 Antibody Avelumab (MSB0010718C) on Human Tumor Cells.

PubMed

Boyerinas, Benjamin; Jochems, Caroline; Fantini, Massimo; Heery, Christopher R; Gulley, James L; Tsang, Kwong Yok; Schlom, Jeffrey

2015-10-01

Several anti-PD-1/PD-L1 monoclonal antibodies (mAb) are currently providing evidence of clinical benefit in subsets of cancer patients. The mode of action of these mAbs is to inhibit PD-1 on immune cells interacting with PD-L1 on tumor cells. These mAbs are either designed or engineered to eliminate antibody-dependent cell-mediated cytotoxicity (ADCC), which, however, has been implicated as an important mechanism in several highly effective mAb-mediated cancer therapies. A fully human anti-PD-L1 mAb would potentially be able to block PD-1/PD-L1 interactions and also mediate the ADCC lysis of tumor cells. MSB0010718C (designated avelumab) is a fully human IgG1 anti-PD-L1 mAb. The studies reported here demonstrate (i) the ability of avelumab to lyse a range of human tumor cells in the presence of PBMC or NK effectors; (ii) IFNγ can enhance tumor cell PD-L1 expression and, in some cases, enhance ADCC tumor cell lysis; (iii) purified NK cells are potent effectors for avelumab; (iv) similar levels of avelumab-mediated ADCC lysis of tumor cells are seen using purified NK as effectors from either healthy donors or cancer patients; (v) very low levels of avelumab-mediated lysis are seen using whole PBMCs as targets; this finding complements results seen in analyses of PBMC subsets of patients receiving avelumab; and (vi) the addition of IL12 to NK cells greatly enhances avelumab-mediated ADCC. These studies thus provide an additional mode of action for an anti-PD-L1 mAb and support the rationale for further studies to enhance avelumab-mediated ADCC activity. ©2015 American Association for Cancer Research.

Immune changes during short-duration missions

NASA Technical Reports Server (NTRS)

Taylor, G. R.

1993-01-01

Spaceflight materially influences the immune mechanism of humans and animals. Effects resulting from missions of less than 1 month are examined. Effects from longer missions are discussed in the companion paper by Konstantinova et al. Most immunology studies have involved analyses of subjects and samples from subjects obtained after flight, with the data being compared with similar data obtained before flight. These studies have demonstrated that short-duration missions can result in a postflight depression in blast cell transformation, major changes in cytokine function, and alterations in the relative numbers of immune cell populations. In addition to these post- vs. preflight studies, some data have been produced in flight. However, these in vitro analyses have been less than satisfactory because of differences between in-flight and ground-control conditions. Recently, both the U.S. and Russian space programs have started collecting in-flight, in vivo, cell-mediated immunity data. These studies have confirmed that the human cell-mediated immune system is blunted during spaceflight.

Immune changes during short-duration missions.

PubMed

Taylor, G R

1993-09-01

Spaceflight materially influences the immune mechanism of humans and animals. Effects resulting from missions of less than 1 month are examined. Effects from longer missions are discussed in the companion paper by Konstantinova et al. Most immunology studies have involved analyses of subjects and samples from subjects obtained after flight, with the data being compared with similar data obtained before flight. These studies have demonstrated that short-duration missions can result in a postflight depression in blast cell transformation, major changes in cytokine function, and alterations in the relative numbers of immune cell populations. In addition to these post- vs. preflight studies, some data have been produced in flight. However, these in vitro analyses have been less than satisfactory because of differences between in-flight and ground-control conditions. Recently, both the U.S. and Russian space programs have started collecting in-flight, in vivo, cell-mediated immunity data. These studies have confirmed that the human cell-mediated immune system is blunted during spaceflight.

Role of thought-related beliefs and coping strategies in the escalation of intrusive thoughts: an analog to obsessive-compulsive disorder.

PubMed

Marcks, Brook A; Woods, Douglas W

2007-11-01

Cognitive-behavioral models of obsessive-compulsive disorder (OCD) assume that obsessions have their origin in normal intrusive thoughts. These models propose that certain beliefs, such as thought-action fusion (TAF) beliefs, combined with the use of ineffective coping strategies, such as thought suppression, lead to the development of OCD. The purpose of the current study was to examine the relationship between these variables in a non-clinical sample in addition to exploring the effects of an alternative, acceptance-based coping strategy. This study explored the relationship between TAF beliefs, thought suppression, and OC-consistent symptoms via mediational analyses. Results showed that thought suppression mediated the relationship between TAF beliefs and OC-consistent symptoms. This study also experimentally examined the effects of various coping strategies (suppression, acceptance, or monitor-only) on the frequency of a distressing intrusion and appraisal ratings (e.g., anxiety, guilt, responsibility) after a TAF induction. Spontaneous suppression in the monitor-only group made comparisons of the experimental data difficult. However, analyses provided preliminary evidence suggesting that thought suppression is related to more intrusions, higher levels of anxiety, and negative appraisals, whereas an acceptance-based approach may be a useful alternative. Additional findings, limitations of the current study, and directions for future research are discussed.

Cross-Sectional Analysis of Longitudinal Mediation Processes.

PubMed

O'Laughlin, Kristine D; Martin, Monica J; Ferrer, Emilio

2018-01-01

Statistical mediation analysis can help to identify and explain the mechanisms behind psychological processes. Examining a set of variables for mediation effects is a ubiquitous process in the social sciences literature; however, despite evidence suggesting that cross-sectional data can misrepresent the mediation of longitudinal processes, cross-sectional analyses continue to be used in this manner. Alternative longitudinal mediation models, including those rooted in a structural equation modeling framework (cross-lagged panel, latent growth curve, and latent difference score models) are currently available and may provide a better representation of mediation processes for longitudinal data. The purpose of this paper is twofold: first, we provide a comparison of cross-sectional and longitudinal mediation models; second, we advocate using models to evaluate mediation effects that capture the temporal sequence of the process under study. Two separate empirical examples are presented to illustrate differences in the conclusions drawn from cross-sectional and longitudinal mediation analyses. Findings from these examples yielded substantial differences in interpretations between the cross-sectional and longitudinal mediation models considered here. Based on these observations, researchers should use caution when attempting to use cross-sectional data in place of longitudinal data for mediation analyses.

Glycosaminoglycan-Mediated Downstream Signaling of CXCL8 Binding to Endothelial Cells

PubMed Central

Derler, Rupert; Weber, Corinna; Strutzmann, Elisabeth; Miller, Ingrid; Kungl, Andreas

2017-01-01

The recruitment of leukocytes, mediated by endothelium bound chemokine gradients, is a vital process in inflammation. The highly negatively charged, unbranched polysaccharide family of glycosaminoglycans (GAGs), such as heparan sulfate and chondroitin sulfate mediate chemokine immobilization. Specifically the binding of CXCL8 (interleukin 8) to GAGs on endothelial cell surfaces is known to regulate neutrophil recruitment. Currently, it is not clear if binding of CXCL8 to GAGs leads to endothelial downstream signaling in addition to the typical CXCR1/CXCR2 (C-X-C motif chemokine receptor 1 and 2)-mediated signaling which activates neutrophils. Here we have investigated the changes in protein expression of human microvascular endothelial cells induced by CXCL8. Tumor necrosis factor alpha (TNFα) stimulation was used to mimic an inflammatory state which allowed us to identify syndecan-4 (SDC4) as the potential proteoglycan co-receptor of CXCL8 by gene array, real-time PCR and flow cytometry experiments. Enzymatic GAG depolymerization via heparinase III and chondroitinase ABC was used to emulate the effect of glycocalyx remodeling on CXCL8-induced endothelial downstream signaling. Proteomic analyses showed changes in the expression pattern of a number of endothelial proteins such as Zyxin and Caldesmon involved in cytoskeletal organization, cell adhesion and cell mobility. These results demonstrate for the first time a potential role of GAG-mediated endothelial downstream signaling in addition to the well-known CXCL8-CXCR1/CXCR2 signaling pathways in neutrophils. PMID:29207576

Sleep Disturbance and Depression Symptoms Mediate the Relationship between Pain and Cognitive Dysfunction in Lupus Patients.

PubMed

Lillis, Teresa A; Tirone, Vanessa; Gandhi, Nisarg; Weinberg, Stacy; Nika, Ailda; Sequeira, Winston; Hobfoll, Stevan E; Block, Joel A; Jolly, Meenakshi

2018-05-04

The current study explored whether sleep disturbance and depression symptoms mediated the relationship between pain and Cognitive Dysfunction (CD) in a sample of 115 patients with Systemic Lupus Erythematosus (SLE). 115 consenting SLE patients completed questionnaires on pain, perceived stress, depression, sleep, and CD. Relationships among pain, sleep, depression and CD were assessed with bootstrapped mediation models controlling for race/ethnicity, fibromyalgia diagnosis, current corticosteroid use, disease activity and damage, and perceived stress. Mediation analyses indicated that the effect of pain on CD was mediated by sleep disturbance (β = 0.30) and depression symptoms (β = 0.33). These effects were maintained even after controlling for aforementioned covariates, of which, only disease activity (β= 0.20) and stress (β=.22) remained significantly linked to CD [Overall Model R 2 = .53; all p's <.05). Even after controlling for disease activity and perceived stress, the relationship between pain and CD was explained by sleep disturbance and depression symptoms. Although these relationships need validation in longitudinal studies with additional measurement modalities, our findings may indicate promising, non-pharmacologic intervention avenues for SLE patients with pain and CD. Specifically, cognitive-behavioral therapies for depression and sleep are known to reduce distress and enhance functioning across various psychosocial domains. Given the symptom burden of SLE, interventions that maximize potential benefits without additional pharmacologic treatments may be of particular utility. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The relationship between alexithymia and maladaptive perfectionism in eating disorders: a mediation moderation analysis methodology.

PubMed

Marsero, S; Ruggiero, G M; Scarone, S; Bertelli, S; Sassaroli, S

2011-09-01

This work aimed to explore the relationship between alexithymia and maladaptive perfectionism in the psychological process leading to eating disorders (ED). Forty-nine individuals with ED and 49 controls completed the Concern over Mistakes subscale of the Frost Multidimensional Perfectionism Scale, the Perfectionism subscale of the Eating Disorders Inventory, the total score of the Toronto Alexithymia Scale, and the Drive for Thinness, Bulimia, and Body Dissatisfaction subscales of the Eating Disorders Inventory. We tested a model in which alexythimia is the independent variable and perfectionism is the possible mediator or moderator. Analyses confirmed the assumed model. In addition, it emerged that perfectionism played a mediating or moderating role when measured by different instruments. This result suggested that different instruments measured subtly different aspects of the same construct. Results could suggest that alexithymia is a predisposing factor for perfectionism, which in turn may lead to the development of eating disorders.

Childhood social withdrawal, interpersonal impairment, and young adult depression: a mediational model.

PubMed

Katz, Shaina J; Conway, Christopher C; Hammen, Constance L; Brennan, Patricia A; Najman, Jake M

2011-11-01

Building on interpersonal theories of depression, the current study sought to explore whether early childhood social withdrawal serves as a risk factor for depressive symptoms and diagnoses in young adulthood. The researchers hypothesized that social impairment at age 15 would mediate the association between social withdrawal at age 5 and depression by age 20. This mediational model was tested in a community sample of 702 Australian youth followed from mother's pregnancy to youth age 20. Structural equation modeling analyses found support for a model in which childhood social withdrawal predicted adolescent social impairment, which, in turn, predicted depression in young adulthood. Additionally, gender was found to moderate the relationship between adolescent social impairment and depression in early adulthood, with females exhibiting a stronger association between social functioning and depression at the symptom and diagnostic level. This study illuminates one potential pathway from early developing social difficulties to later depressive symptoms and disorders.

Childhood Social Withdrawal, Interpersonal Impairment, and Young Adult Depression: A Mediational Model

PubMed Central

Katz, Shaina J.; Conway, Christopher C.; Hammen, Constance L.; Brennan, Patricia A.; Najman, Jake M.

2012-01-01

Building on interpersonal theories of depression, the current study sought to explore whether early childhood social withdrawal serves as a risk factor for depressive symptoms and diagnoses in young adulthood. The researchers hypothesized that social impairment at age 15 would mediate the association between social withdrawal at age 5 and depression by age 20. This mediational model was tested in a community sample of 702 Australian youth followed from mother’s pregnancy to youth age 20. Structural equation modeling analyses found support for a model in which childhood social withdrawal predicted adolescent social impairment, which, in turn, predicted depression in young adulthood. Additionally, gender was found to moderate the relationship between adolescent social impairment and depression in early adulthood, with females exhibiting a stronger association between social functioning and depression at the symptom and diagnostic level. This study illuminates one potential pathway from early developing social difficulties to later depressive symptoms and disorders. PMID:21744059

The interplay between customer participation and difficulty of design examples in the online designing process and its effect on customer satisfaction: mediational analyses.

PubMed

Chang, Chia-Chi; Chen, Hui-Yun; Huang, I-Chiang

2009-04-01

In the current consumer-centric economy, consumers increasingly desire the opportunity to design their own products in order to express more effectively their self-image. Mass customization, based on efficient and flexible modulization designs, has provided individualized products to satisfy this desire. This work presents an experiment employed to demonstrate that customer participation leads to higher satisfaction. Specifically, the increment in customer satisfaction due to participation is greater when an easy example is provided than when either no example or a difficult one is provided. Additionally, self-congruity plays a mediating role on the customer participation-satisfaction relationship, and this mediating effect varies across different levels of the design example provided in the design process. When an easy design example is present, customer participation has a direct effect on satisfaction, in addition to the indirect effect of self-congruity. When a difficult example is provided, customer participation does not have incremental effects on either self-congruity or customer satisfaction. Finally, when no design example is shown to customers, contrary to our expectation, participation still enhances customer satisfaction due to an increased sense of self-congruity.

An interpersonal perspective on depression: the role of marital adjustment, conflict communication, attributions, and attachment within a clinical sample.

PubMed

Heene, Els; Buysse, Ann; Van Oost, Paulette

2007-12-01

Previous studies have focused on the difficulties in psychosocial functioning in depressed persons, underscoring the distress experienced by both spouses. We selected conflict communication, attribution, and attachment as important domains of depression in the context of marital adjustment, and we analyzed two hypotheses in one single study. First, we analyzed whether a clinical sample of couples with a depressed patient would differ significantly from a control group on these variables. Second, we explored to what degree these variables mediate/moderate the relationship between depressive symptoms and marital adjustment. The perspectives of both spouses were taken into account, as well as gender differences. In total, 69 clinical and 69 control couples were recruited, and a series of multivariate analyses of variance and regression analyses were conducted to test both hypotheses. Results indicated that both patients and their partners reported less marital adjustment associated with more negative perceptions on conflict communication, causal attributions, and insecure attachment. In addition, conflict communication and causal attributions were significant mediators of the association between depressive symptoms and marital adjustment for both depressed men and women, and causal attributions also moderated this link. Ambivalent attachment was a significant mediator only for the female identified patients. Several sex differences and clinical implications are discussed.

Soybean peroxidase-mediated degradation of an azo dye– a detailed mechanistic study

PubMed Central

2013-01-01

Background Peroxidases are emerging as an important class of enzymes that can be used for the efficient degradation of organic pollutants. However, detailed studies identifying the various intermediates produced and the mechanisms involved in the enzyme-mediated pollutant degradation are not widely published. Results In the present study, the enzymatic degradation of an azo dye (Crystal Ponceau 6R, CP6R) was studied using commercially available soybean peroxidase (SBP) enzyme. Several operational parameters affecting the enzymatic degradation of dye were evaluated and optimized, such as initial dye concentration, H2O2 dosage, mediator amount and pH of the solution. Under optimized conditions, 40 ppm dye solution could be completely degraded in under one minute by SBP in the presence of H2O2 and a redox mediator. Dye degradation was also confirmed using HPLC and TOC analyses, which showed that most of the dye was being mineralized to CO2 in the process. Conclusions Detailed analysis of metabolites, based on LC/MS results, showed that the enzyme-based degradation of the CP6R dye proceeded in two different reaction pathways- via symmetric azo bond cleavage as well as asymmetric azo bond breakage in the dye molecule. In addition, various critical transformative and oxidative steps such as deamination, desulfonation, keto-oxidation are explained on an electronic level. Furthermore, LC/MS/MS analyses confirmed that the end products in both pathways were small chain aliphatic carboxylic acids. PMID:24308857

The Dual Estrogen Receptor α Inhibitory Effects of the Tissue-Selective Estrogen Complex for Endometrial and Breast Safety

PubMed Central

Han, Sang Jun; Begum, Khurshida; Foulds, Charles E.; Hamilton, Ross A.; Bailey, Suzanna; Malovannaya, Anna; Chan, Doug; Qin, Jun

2016-01-01

The conjugated estrogen/bazedoxifene tissue-selective estrogen complex (TSEC) is designed to minimize the undesirable effects of estrogen in the uterus and breast tissues and to allow the beneficial effects of estrogen in other estrogen-target tissues, such as the bone and brain. However, the molecular mechanism underlying endometrial and breast safety during TSEC use is not fully understood. Estrogen receptor α (ERα)–estrogen response element (ERE)–DNA pull-down assays using HeLa nuclear extracts followed by mass spectrometry–immunoblotting analyses revealed that, upon TSEC treatment, ERα interacted with transcriptional repressors rather than coactivators. Therefore, the TSEC-mediated recruitment of transcriptional repressors suppresses ERα-mediated transcription in the breast and uterus. In addition, TSEC treatment also degraded ERα protein in uterine tissue and breast cancer cells, but not in bone cells. Interestingly, ERα-ERE-DNA pull-down assays also revealed that, upon TSEC treatment, ERα interacted with the F-box protein 45 (FBXO45) E3 ubiquitin ligase. The loss-of- and gain-of-FBXO45 function analyses indicated that FBXO45 is involved in TSEC-mediated degradation of the ERα protein in endometrial and breast cells. In preclinical studies, these synergistic effects of TSEC on ERα inhibition also suppressed the estrogen-dependent progression of endometriosis. Therefore, the endometrial and breast safety effects of TSEC are associated with synergy between the selective recruitment of transcriptional repressors to ERα and FBXO45-mediated degradation of the ERα protein. PMID:26487511

Cognitive and adaptive correlates of an ADOS-derived joint attention composite

PubMed Central

Harrison, Ashley Johnson; Lu, Zhenqiu (Laura); McLean, Rebecca L.; Sheinkopf, Stephen J.

2016-01-01

Joint attention skills have been shown to predict language outcomes in children with autism spectrum disorder (ASD). Less is known about the relationship between joint attention (JA) abilities in children with ASD and cognitive and adaptive abilities. In the current study, a subset of items from the Autism Diagnostic Observation Schedule (ADOS), designed to quantify JA abilities, were used to investigate social attention among an unusually large cross-sectional sample of children with ASD (n = 1061). An examination of the association between JA and a range of functional correlates (cognitive and adaptive) revealed JA was significantly related to verbal (VIQ) and non-verbal (NVIQ) cognitive ability as well as all domains of adaptive functioning (socialization, communication, and daily living skills). Additional analyses examined the degree to which the relation between adaptive abilities (socialization, communication, and daily living skills) and JA was maintained after taking into account the potentially mediating role of verbal and nonverbal cognitive ability. Results revealed that VIQ fully mediated the relation between JA and adaptive functioning, whereas the relation between these adaptive variables and JA was only partially mediated by NVIQ. Moderation analyses were also conducted to examine how verbal and non-verbal cognitive ability and gender impacted the relation between JA and adaptive functioning. In line with research showing a relation between language and JA, this indicates that while JA is significantly related to functional outcomes, this appears to be mediated specifically through a verbal cognitive pathway. PMID:28168003

Association between sleep difficulties as well as duration and hypertension: is BMI a mediator?

PubMed

Carrillo-Larco, R M; Bernabe-Ortiz, A; Sacksteder, K A; Diez-Canseco, F; Cárdenas, M K; Gilman, R H; Miranda, J J

2017-01-01

Sleep difficulties and short sleep duration have been associated with hypertension. Though body mass index (BMI) may be a mediator variable, the mediation effect has not been defined. We aimed to assess the association between sleep duration and sleep difficulties with hypertension, to determine if BMI is a mediator variable, and to quantify the mediation effect. We conducted a mediation analysis and calculated prevalence ratios with 95% confidence intervals. The exposure variables were sleep duration and sleep difficulties, and the outcome was hypertension. Sleep difficulties were statistically significantly associated with a 43% higher prevalence of hypertension in multivariable analyses; results were not statistically significant for sleep duration. In these analyses, and in sex-specific subgroup analyses, we found no strong evidence that BMI mediated the association between sleep indices and risk of hypertension. Our findings suggest that BMI does not appear to mediate the association between sleep patterns and hypertension. These results highlight the need to further study the mechanisms underlying the relationship between sleep patterns and cardiovascular risk factors.

Effect of Caring for an Abusive Parent on Mental Health: The Mediating Role of Self-Esteem.

PubMed

Kong, Jooyoung

2018-05-08

This study examines a sample of filial caregivers to investigate whether and how a history of childhood abuse is associated with caregivers' mental health (i.e., depressed affect, psychological well-being, and life satisfaction). This study also investigates the mediational role of self-esteem between caring for an abusive parent and the mental health outcomes. Using the 2004-2006 National Survey of Midlife Development in the United States, data from 219 filial caregivers were analyzed. A series of ordinary least squares (OLS) regression and mediational analyses were conducted to estimate the direct and indirect effects of providing care to an abusive parent on negative affect, psychological well-being, and levels of life satisfaction. Key results showed that providing care to an abusive parent was associated with greater depressed affect and lower levels of life satisfaction. In addition, self-esteem served as a significant mediator: providing care to an abusive parent was associated with lower self-esteem, which was, in turn, ultimately associated with greater depressed affect, diminished psychological well-being, and lower levels of life satisfaction. Filial caregivers with a history of childhood abuse should be acknowledged as a high-risk group of caregivers so that they can gain attention and support for targeted interventions. Additionally, evidence-based intervention programs (e.g., improving self-esteem issues) should be designed and implemented to address this group's unique challenges and concerns.

POWER ANALYSIS FOR COMPLEX MEDIATIONAL DESIGNS USING MONTE CARLO METHODS

PubMed Central

Thoemmes, Felix; MacKinnon, David P.; Reiser, Mark R.

2013-01-01

Applied researchers often include mediation effects in applications of advanced methods such as latent variable models and linear growth curve models. Guidance on how to estimate statistical power to detect mediation for these models has not yet been addressed in the literature. We describe a general framework for power analyses for complex mediational models. The approach is based on the well known technique of generating a large number of samples in a Monte Carlo study, and estimating power as the percentage of cases in which an estimate of interest is significantly different from zero. Examples of power calculation for commonly used mediational models are provided. Power analyses for the single mediator, multiple mediators, three-path mediation, mediation with latent variables, moderated mediation, and mediation in longitudinal designs are described. Annotated sample syntax for Mplus is appended and tabled values of required sample sizes are shown for some models. PMID:23935262

Predictors of cancer fear: the association between mass media and fear of cancer among cancer diagnosed and nondiagnosed individuals.

PubMed

Nelissen, Sara; Beullens, Kathleen; Lemal, Marijke; Van den Bulck, Jan

2015-03-01

Few studies have explored the impact of mass media on fear of cancer levels. This study investigates whether television and Internet use are associated with fear of cancer, and whether this association is different for cancer diagnosed and nondiagnosed individuals. A quantitative, standardized survey was used and administered to 2008 respondents in Flanders (Belgium), of which 621 individuals were diagnosed with cancer. For statistical analyses, hierarchical regression analyses, independent samples T-tests and post hoc mediation analyses were conducted. The results indicated that cancer diagnosed individuals differed from nondiagnosed individuals in terms of perceived cancer susceptibility, perceived cancer severity, fear of cancer, and media use. Furthermore, television exposure was directly and positively related to fear of cancer, whereas Internet use was not. The relationship between television and Internet use and fear of cancer was not different for cancer diagnosed and nondiagnosed individuals. Additional post hoc mediation analyses, however, seemed to suggest that watching more television and surfing more on the Internet could both lead to having a more negative perceived health and this was in turn associated with higher fear of cancer. To help reduce the burden of fear of cancer, cancer educators and individuals working with cancer patients need to be aware of the possible negative effects media use might have on health perception and on the levels of fear of cancer.

Reduction of dioxin-like toxicity in effluents by additional wastewater treatment and related effects in fish.

PubMed

Maier, Diana; Benisek, Martin; Blaha, Ludek; Dondero, Francesco; Giesy, John P; Köhler, Heinz-R; Richter, Doreen; Scheurer, Marco; Triebskorn, Rita

2016-10-01

Efficiency of advanced wastewater treatment technologies to reduce micropollutants which mediate dioxin-like toxicity was investigated. Technologies compared included ozonation, powdered activated carbon and granular activated carbon. In addition to chemical analyses in samples of effluents, surface waters, sediments, and fish, (1) dioxin-like potentials were measured in paired samples of effluents, surface waters, and sediments by use of an in vitro biotest (reporter gene assay) and (2) dioxin-like effects were investigated in exposed fish by use of in vivo activity of the mixed-function, monooxygenase enzyme, ethoxyresorufin O-deethylase (EROD) in liver. All advanced technologies studied, based on degradation or adsorption, significantly reduced dioxin-like potentials in samples and resulted in lesser EROD activity in livers of fish. Results of in vitro and in vivo biological responses were not clearly related to quantification of targeted analytes by use of instrumental analyses. Copyright © 2016 Elsevier Inc. All rights reserved.

Buprenorphine decreases the CCL2-mediated chemotactic response of monocytes.

PubMed

Carvallo, Loreto; Lopez, Lillie; Che, Fa-Yun; Lim, Jihyeon; Eugenin, Eliseo A; Williams, Dionna W; Nieves, Edward; Calderon, Tina M; Madrid-Aliste, Carlos; Fiser, Andras; Weiss, Louis; Angeletti, Ruth Hogue; Berman, Joan W

2015-04-01

Despite successful combined antiretroviral therapy, ∼ 60% of HIV-infected people exhibit HIV-associated neurocognitive disorders (HAND). CCL2 is elevated in the CNS of infected people with HAND and mediates monocyte influx into the CNS, which is critical in neuroAIDS. Many HIV-infected opiate abusers have increased neuroinflammation that may augment HAND. Buprenorphine is used to treat opiate addiction. However, there are few studies that examine its impact on HIV neuropathogenesis. We show that buprenorphine reduces the chemotactic phenotype of monocytes. Buprenorphine decreases the formation of membrane projections in response to CCL2. It also decreases CCL2-induced chemotaxis and mediates a delay in reinsertion of the CCL2 receptor, CCR2, into the cell membrane after CCL2-mediated receptor internalization, suggesting a mechanism of action of buprenorphine. Signaling pathways in CCL2-induced migration include increased phosphorylation of p38 MAPK and of the junctional protein JAM-A. We show that buprenorphine decreases these phosphorylations in CCL2-treated monocytes. Using DAMGO, CTAP, and Nor-BNI, we demonstrate that the effect of buprenorphine on CCL2 signaling is opioid receptor mediated. To identify additional potential mechanisms by which buprenorphine inhibits CCL2-induced monocyte migration, we performed proteomic analyses to characterize additional proteins in monocytes whose phosphorylation after CCL2 treatment was inhibited by buprenorphine. Leukosialin and S100A9 were identified and had not been shown previously to be involved in monocyte migration. We propose that buprenorphine limits CCL2-mediated monocyte transmigration into the CNS, thereby reducing neuroinflammation characteristic of HAND. Our findings underscore the use of buprenorphine as a therapeutic for neuroinflammation as well as for addiction. Copyright © 2015 by The American Association of Immunologists, Inc.

How and for whom does web-based acceptance and commitment therapy work? Mediation and moderation analyses of web-based ACT for depressive symptoms.

PubMed

Pots, Wendy T M; Trompetter, Hester R; Schreurs, Karlein M G; Bohlmeijer, Ernst T

2016-05-23

Acceptance and Commitment Therapy (ACT) has been demonstrated to be effective in reducing depressive symptoms. However, little is known how and for whom therapeutic change occurs, specifically in web-based interventions. This study focuses on the mediators, moderators and predictors of change during a web-based ACT intervention. Data from 236 adults from the general population with mild to moderate depressive symptoms, randomized to either web-based ACT (n = 82) or one of two control conditions (web-based Expressive Writing (EW; n = 67) and a waiting list (n = 87)), were analysed. Single and multiple mediation analyses, and exploratory linear regression analyses were performed using PROCESS and linear regression analyses, to examine mediators, moderators and predictors on pre- to post- and follow-up treatment change of depressive symptoms. The treatment effect of ACT versus the waiting list was mediated by psychological flexibility and two mindfulness facets. The treatment effect of ACT versus EW was not significantly mediated. The moderator analyses demonstrated that the effects of web-based ACT did not vary according to baseline patient characteristics when compared to both control groups. However, higher baseline depressive symptoms and positive mental health and lower baseline anxiety were identified as predictors of outcome across all conditions. Similar results are found for follow-up. The findings of this study corroborate the evidence that psychological flexibility and mindfulness are distinct process mechanisms that mediate the effects of web-based ACT intervention. The results indicate that there are no restrictions to the allocation of web-based ACT intervention and that web-based ACT can work for different subpopulations. Netherlands Trial Register NTR2736 . Registered 6 February 2011.

Estimating the temporal evolution of Alzheimer's disease pathology with autopsy data.

PubMed

Royall, Donald R; Palmer, Raymond F

2012-01-01

The temporal growth of Alzheimer's disease (AD) neuropathology cannot be easily determined because autopsy data are available only after death. We combined autopsy data from 471 participants in the Honolulu-Asia Aging Study (HAAS) into latent factor measures of neurofibrillary tangle and neuritic plaque counts. These were associated with intercept and slope parameters from a latent growth curve (LGC) model of 9-year change in cognitive test performance in 3244 autopsied and non-autopsied HAAS participants. Change in cognition fully mediated the association between baseline cognitive performance and AD lesions counts. The mediation effect of cognitive change on both AD lesion models effectively dates them within the period of cognitive surveillance. Additional analyses could lead to an improved understanding of lesion propagation in AD.

Psychological Vulnerability and Problem Gambling: The Mediational Role of Cognitive Distortions.

PubMed

Lévesque, David; Sévigny, Serge; Giroux, Isabelle; Jacques, Christian

2018-01-03

Despite numerous studies demonstrating the influence of cognitive distortions on gambling problem severity, empirical data regarding the role of psychological vulnerability on the latter is limited. Hence, this study assesses the mediating effect of cognitive distortions between psychological vulnerability (personality and mood), and gambling problem severity. It also verifies whether the relationships between these variables differs according to the preferred gambling activity. The sample is composed of 272 male gamblers [191 poker players; 81 video lottery terminal (VLT) players] aged between 18 and 82 years (M = 35.2). Bootstrap analysis results revealed that cognitive distortions mediate the effect of narcissism on gambling problem severity for both groups. The level of depression for VLT players significantly predicted gambling problem severity, both directly and indirectly via the mediating effect of cognitive distortions. Mediation analyses also indicated that narcissism had an indirect impact on problem gambling through cognitive distortions for both groups. These findings suggest that certain vulnerabilities related to personality and mood may influence cognitive distortion intensity and gambling problem severity. In addition, psychological vulnerabilities could differ based on preferred gambling activity. These results may be useful for prevention policies, identifying high risk gamblers and planning psychological interventions.

Social anxiety and heavy situational drinking: coping and conformity motives as multiple mediators.

PubMed

Terlecki, Meredith A; Buckner, Julia D

2015-01-01

Individuals with clinically elevated social anxiety are at greater risk for alcohol use disorder, and the relation between social anxiety and drinking problems is at least partially accounted for by drinking more in negative emotional (e.g., feeling sad or angry) and personal/intimate (e.g., before sexual intercourse) situations. Identification of cognitive/motivational factors related to drinking in these high-risk situations could inform the development of treatment and prevention interventions for these high-risk drinkers. The current cross-sectional study examined the mediating effect of drinking motives on the relationship between social anxiety and drinking these high-risk situations among undergraduates (N=232). Clinically elevated social anxiety was associated with greater coping and conformity motives. Both coping and conformity motives mediated the relation between social anxiety and heavier alcohol consumption in negative emotional and personal/intimate contexts. Multiple mediation analyses indicated that these motives work additively to mediate the social anxiety-drinking situations relationship, such that heavy situational drinking among undergraduates with clinically elevated social anxiety can be jointly attributed to desire to cope with negative affect and to avoid social scrutiny. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of Intimate Partner Violence on Infant Temperament.

PubMed

Edhborg, Maigun; E-Nasreen, Hashima; Kabir, Zarina Nahar

2017-06-01

Intimate partner violence (IPV) during the first year postpartum is common in Bangladesh, and many infants are exposed to hostile and aggressive environment. The aim of the current study was to investigate how IPV (physical, emotional, and sexual) impacts on the mother's perception of her infant's temperament 6 to 8 months postpartum, and whether maternal depressive symptom at 6 to 8 months postpartum is a mediator in this association. A total of 656 rural Bangladeshi women and their children 6 to 8 months postpartum were included in this study. Data were collected by structured interviews. The women were asked about physical, sexual, and emotional IPV; depressive symptoms (Edinburgh Postnatal Depressive Symptoms [EPDS]); and their perception of infant temperament assessed by the Infant Characteristic Questionnaire (ICQ). Descriptive analyses were conducted for prevalence of IPV and maternal depressive symptoms. Mediation analysis was conducted with a series of linear regressions with types of IPV as independent variables, ICQ including its subscales as dependent variables and maternal depressive symptoms as potential mediator. All the analyses were adjusted for the woman's and her husband's ages and number of children of the couple. Nearly 90% of the mothers reported some kind of IPV at 6 to 8 months postpartum. All types of IPV were directly associated with the mother's perception of her infant as unadaptable. Maternal depressive symptom was a mediating factor between physical IPV and the ICQ subscales fussy-difficult and unpredictable. In addition, depressive symptoms mediated between sexual and emotional IPV, and the mother's perception of the infant as unpredictable. The results showed that IPV influenced how mothers perceived their infant's temperament. It is important that health care professionals at maternal and child health services enquire about IPV with possibilities to refer the family or the mother and infant for appropriate support.

Mediating pathways and gender differences between shift work and subjective cognitive function.

PubMed

Wong, Imelda S; Smith, Peter M; Ibrahim, Selahadin; Mustard, Cameron A; Gignac, Monique A M

2016-11-01

Increased injury risk among shift workers is often attributed to cognitive function deficits that come about as a result of sleep disruptions. However, little is known about the intermediate influences of other factors (eg, work stress, health) which may affect this relationship. In addition, gender differences in these the complex relationships have not been fully explored. The purpose of this study is to (1) identify the extent to which work and non-work factors mediate the relationship between shift work, sleep and subsequent subjective cognitive function; and (2) determine if the mediating pathways differ for men and women. Data from the 2010 National Population Health Survey was used to create a cross-sectional sample of 4255 employed Canadians. Using path modelling, we examined the direct and indirect relationships between shift work, sleep duration, sleep quality and subjective cognitive function. Multigroup analyses tested for significantly different pathways between men and women. Potential confounding effects of age and self-reported health and potential mediating effects of work stress were simultaneously examined. Work stress and sleep quality significantly mediated the effects of shift work on cognition. Age and health confounded the relationship between sleep quality and subjective cognition. No differences were found between men and women. Occupational health and safety programmes are needed to address stress and health factors, in addition to sleep hygiene, to effectively address cognitive function among shift workers. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Inhibitory effects of low molecular weight heparin on mediator release by mast cells: preferential inhibition of cytokine production and mast cell-dependent cutaneous inflammation

PubMed Central

BARAM, D; RASHKOVSKY, M; HERSHKOVIZ, R; DRUCKER, I; RESHEF, T; BEN-SHITRIT, S; MEKORI, Y A

1997-01-01

There has been substantial evidence that suggests that heparin may modulate various aspects of immune function and inflammation in addition to its well known anticoagulant activity. In this regard heparin was found to suppress cell-mediated immune responses or asthmatic reactions to allergen challenge. In the present study we analyse the effects of low molecular weight heparin (LMWH) on mast cell degranulation and cytokine production in vitro and on the elicitation of IgE-mediated mast cell-dependent late cutaneous allergic inflammation in vivo. We have established that LMWH preferentially inhibited tumour necrosis factor-alpha (TNF-α) and IL-4 production without having any significant effect on mast cell degranulation. These effects have been observed in mast cells derived from three different origins that were activated by either immunological or non-immunological stimuli. We have shown that there is inhibition of TNF-α production (and not neutralization of activity), as elimination of the drug after a short preincubation and addition of LMWH to rTNF-α had no effect on TNF-α-mediated cytotoxic activity. These results were also confirmed by ELISA. In vivo, s.c. injection of the LMWH inhibited the leucocyte infiltration associated with the late cutaneous response which followed passive cutaneous anaphylaxis (PCA) reaction, without affecting mast cell numbers or degranulation. These data suggest that LMWH may have an inhibitory role in mast cell-mediated allergic inflammation, and thus might be considered as a possible therapeutic modality. PMID:9409655

Gender difference in sickness absence from work: a multiple mediation analysis of psychosocial factors.

PubMed

Casini, Annalisa; Godin, Isabelle; Clays, Els; Kittel, France

2013-08-01

Previous research has shown that job characteristics, private life and psychosocial factors partially account for gender difference in work absences because of sickness. Most studies have analysed these factors separately. The aim of the present study was to evaluate whether these explanatory factors act as mediators when they are considered simultaneously. The evaluated data set comprises the merger of two Belgian longitudinal studies, BELSTRESS III and SOMSTRESS. It includes 3821 workers (1541 men) aged 21-66 years, employed in eight organizations. A multiple mediation analysis was performed to explain the higher prevalence among women. Estimated factors were occupational grade, total number of paid working hours per week, job strain, overcommitment, home-work interference and social support at and outside work. Prospective data concerning duration and frequency of medically justified sickness absence (registered by the organizations) were used as outcomes. Overall, the mediating factors partially account for gender difference in sickness absence. The strongest mediator for both outcomes is job strain. In addition, difference in absence duration is mediated by social support at work, whereas difference in frequency is mediated by professional grade and home-work interference. Our results call attention to the necessity to elaborate actual preventive actions aiming at favouring a better positioning of women on the labour market in term of hierarchical level as well as in terms of quality of work for reducing sickness absence in this group.

When ab ≠ c - c': published errors in the reports of single-mediator models.

PubMed

Petrocelli, John V; Clarkson, Joshua J; Whitmire, Melanie B; Moon, Paul E

2013-06-01

Accurate reports of mediation analyses are critical to the assessment of inferences related to causality, since these inferences are consequential for both the evaluation of previous research (e.g., meta-analyses) and the progression of future research. However, upon reexamination, approximately 15% of published articles in psychology contain at least one incorrect statistical conclusion (Bakker & Wicherts, Behavior research methods, 43, 666-678 2011), disparities that beget the question of inaccuracy in mediation reports. To quantify this question of inaccuracy, articles reporting standard use of single-mediator models in three high-impact journals in personality and social psychology during 2011 were examined. More than 24% of the 156 models coded failed an equivalence test (i.e., ab = c - c'), suggesting that one or more regression coefficients in mediation analyses are frequently misreported. The authors cite common sources of errors, provide recommendations for enhanced accuracy in reports of single-mediator models, and discuss implications for alternative methods.

Sequence- and structure-based computational analyses of Gram-negative tripartite efflux pumps in the context of bacterial membranes

DOE PAGES

Travers, Timothy; Wang, Katherine J.; Lopez, Cesar A.; ...

2018-02-09

Gram-negative multidrug resistance currently presents a serious threat to public health with infections effectively rendered untreatable. Multiple molecular mechanisms exist that cause antibiotic resistance and in addition, the last three decades have seen slowing rates of new drug development. In this paper, we summarize the use of various computational techniques for investigating the mechanisms of multidrug resistance mediated by Gram-negative tripartite efflux pumps and membranes. Recent work in our lab combines data-driven sequence and structure analyses to study the interactions and dynamics of these bacterial components. Computational studies can complement experimental methodologies for gaining crucial insights into combatting multidrug resistance.

Sequence- and structure-based computational analyses of Gram-negative tripartite efflux pumps in the context of bacterial membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Travers, Timothy; Wang, Katherine J.; Lopez, Cesar A.

Gram-negative multidrug resistance currently presents a serious threat to public health with infections effectively rendered untreatable. Multiple molecular mechanisms exist that cause antibiotic resistance and in addition, the last three decades have seen slowing rates of new drug development. In this paper, we summarize the use of various computational techniques for investigating the mechanisms of multidrug resistance mediated by Gram-negative tripartite efflux pumps and membranes. Recent work in our lab combines data-driven sequence and structure analyses to study the interactions and dynamics of these bacterial components. Computational studies can complement experimental methodologies for gaining crucial insights into combatting multidrug resistance.

Lipid droplet biology and evolution illuminated by the characterization of a novel perilipin in teleost fish

PubMed Central

Granneman, James G; Kimler, Vickie A; Zhang, Huamei; Ye, Xiangqun; Luo, Xixia; Postlethwait, John H; Thummel, Ryan

2017-01-01

Perilipin (PLIN) proteins constitute an ancient family important in lipid droplet (LD) formation and triglyceride metabolism. We identified an additional PLIN clade (plin6) that is unique to teleosts and can be traced to the two whole genome duplications that occurred early in vertebrate evolution. Plin6 is highly expressed in skin xanthophores, which mediate red/yellow pigmentation and trafficking, but not in tissues associated with lipid metabolism. Biochemical and immunochemical analyses demonstrate that zebrafish Plin6 protein targets the surface of pigment-containing carotenoid droplets (CD). Protein kinase A (PKA) activation, which mediates CD dispersion in xanthophores, phosphorylates Plin6 on conserved residues. Knockout of plin6 in zebrafish severely impairs the ability of CD to concentrate carotenoids and prevents tight clustering of CD within carotenoid bodies. Ultrastructural and functional analyses indicate that LD and CD are homologous structures, and that Plin6 was functionalized early in vertebrate evolution for concentrating and trafficking pigment. DOI: http://dx.doi.org/10.7554/eLife.21771.001 PMID:28244868

From Racial Discrimination to Risky Sex: Prospective Relations Involving Peers and Parents

PubMed Central

Roberts, Megan E.; Gibbons, Frederick X.; Gerrard, Meg; Weng, Chih-Yuan; Murry, Velma M.; Simons, Leslie G.; Simons, Ronald L.; Lorenz, Frederick O.

2013-01-01

This study investigated how early experience with racial discrimination affected the subsequent risky sexual behaviors of a diverse sample of African American youths (N = 745). The analyses focused on 3 risk-promoting factors thought to mediate the hypothesized discrimination → risky sex relation: negative affect, affiliation with deviant peers, and favorable attitudes toward risky sex. In addition, attentive parenting was examined as a protective factor. Analyses using structural equation modeling revealed that youths who perceived more racial discrimination at age 10 or 11 were engaging in more sexual risk taking at age 18 or 19. This relation was mediated by the hypothesized risk-promoting factors via pathways that were consistent with our conceptual model. Results also indicated a prospective reciprocal relation between parenting and children’s deviant affiliations: deviant peer affiliations at age 10 or 11 predicted more attentive parenting behaviors by the parents; this response from the parents, in turn, predicted relatively fewer deviant affiliations when the youths were 15 or 16. Study findings are discussed in terms of their relevance to the disproportionately high rates of sexually transmitted infections among African Americans. PMID:21942666

What explains the socioeconomic status gap in activity? Educational differences in determinants of physical activity and screentime.

PubMed

Hankonen, Nelli; Heino, Matti T J; Kujala, Emilia; Hynynen, Sini-Tuuli; Absetz, Pilvikki; Araújo-Soares, Vera; Borodulin, Katja; Haukkala, Ari

2017-02-01

Designing evidence-based interventions to address socioeconomic disparities in health and health behaviours requires a better understanding of the specific explanatory mechanisms. We aimed to investigate a comprehensive range of potential theoretical mediators of physical activity (PA) and screen time in different socioeconomic status (SES) groups: a high SES group of high school students, and a low SES group of vocational school students. The COM-B system, including the Theoretical Domains Framework (TDF), was used as a heuristic framework to synthesise different theoretical determinants in this exploratory study. Finnish vocational and high school students (N = 659) aged 16-19, responded to a survey assessing psychological, social and environmental determinants of activity (PA and screen time). These determinants are mappable into the COM-B domains: capability, opportunity and motivation. The outcome measures were validated self-report measures for PA and screen time. The statistical analyses included a bootstrapping-based mediation procedure. Regarding PA, there were SES differences in all of the COM-B domains. For example, vocational school students reported using less self-monitoring of PA, weaker injunctive norms to engage in regular PA, and fewer intentions than high school students. Mediation analyses identified potential mediators of the SES-PA relationship in all of three domains: The most important candidates included self-monitoring (CI95 for b: 0.19-0.47), identity (0.04-0.25) and material resources available (0.01-0.16). However, SES was not related to most determinants of screentime, where there were mainly gender differences. Most determinants were similarly related with both behaviours in both SES groups, indicating no major moderation effect of SES on these relationships. This study revealed that already in the first years of educational differentiation, levels of key PA determinants differ, contributing to socioeconomic differences in PA. The analyses identified the strongest mediators of the SES-PA association, but additional investigation utilising longitudinal and experimental designs are needed. This study demonstrates the usefulness of combining constructs from various theoretical approaches to better understand the role of distinct mechanisms that underpin socioeconomic health behaviour disparities.

Genome-wide analyses of LINE–LINE-mediated nonallelic homologous recombination

PubMed Central

Startek, Michał; Szafranski, Przemyslaw; Gambin, Tomasz; Campbell, Ian M.; Hixson, Patricia; Shaw, Chad A.; Stankiewicz, Paweł; Gambin, Anna

2015-01-01

Nonallelic homologous recombination (NAHR), occurring between low-copy repeats (LCRs) >10 kb in size and sharing >97% DNA sequence identity, is responsible for the majority of recurrent genomic rearrangements in the human genome. Recent studies have shown that transposable elements (TEs) can also mediate recurrent deletions and translocations, indicating the features of substrates that mediate NAHR may be significantly less stringent than previously believed. Using >4 kb length and >95% sequence identity criteria, we analyzed of the genome-wide distribution of long interspersed element (LINE) retrotransposon and their potential to mediate NAHR. We identified 17 005 directly oriented LINE pairs located <10 Mbp from each other as potential NAHR substrates, placing 82.8% of the human genome at risk of LINE–LINE-mediated instability. Cross-referencing these regions with CNVs in the Baylor College of Medicine clinical chromosomal microarray database of 36 285 patients, we identified 516 CNVs potentially mediated by LINEs. Using long-range PCR of five different genomic regions in a total of 44 patients, we confirmed that the CNV breakpoints in each patient map within the LINE elements. To additionally assess the scale of LINE–LINE/NAHR phenomenon in the human genome, we tested DNA samples from six healthy individuals on a custom aCGH microarray targeting LINE elements predicted to mediate CNVs and identified 25 LINE–LINE rearrangements. Our data indicate that LINE–LINE-mediated NAHR is widespread and under-recognized, and is an important mechanism of structural rearrangement contributing to human genomic variability. PMID:25613453

Social support and adaptation outcomes in children and adolescents with cerebral palsy.

PubMed

Carona, Carlos; Moreira, Helena; Silva, Neuza; Crespo, Carla; Canavarro, Maria Cristina

2014-01-01

This study had two main objectives: first, to describe the social support and psychological maladjustment of children and adolescents with cerebral palsy (CP); and second, to test a mediation model where psychological maladjustment was hypothesized to mediate the link between social support and health-related quality of life (HRQL). In addition, the moderating role of gender and age was examined for this mediation model. Self- and proxy-report questionnaires on the aforementioned variables were administered to a sample of 96 children/adolescents with CP and 118 healthy controls, as well as one of their parents. Univariate and multivariate analyses of covariance were conducted to examine differences in social support and psychological maladjustment, respectively. PROCESS computational tool was used for path analysis-based mediation, moderation and moderated mediation analyses. Children/adolescents with CP reported lower levels of social support than their healthy peers, but no significant differences emerged in terms of their psychological maladjustment. For children/adolescents with CP, internalizing and externalizing problems were found to mediate the link between social support and HRQL, and these indirect effects were not conditional upon age or gender. Children and adolescents with CP are likely have more negative perceptions of social support, but not necessarily more psychological adjustment problems than their healthy, able-bodied peers. Results further suggest that interventions targeting social support perceptions may positively affect HRQL outcomes in children/adolescents with CP, through the improvement of internalizing and externalizing dimensions of their psychological adjustment. Social support perceptions are important intervention targets in psychosocial rehabilitation with children and adolescents with CP. Children and adolescents with CP do not necessarily present increased psychological maladjustment. Interventions targeting these children and adolescents' social support may promote their psychological adjustment and health-related quality of life. Developmental specificities, such as age and gender differences, should be considered when planning and implementing psychosocial interventions.

The Active for Life Year 5 (AFLY5) school-based cluster randomised controlled trial protocol: detailed statistical analysis plan.

PubMed

Lawlor, Debbie A; Peters, Tim J; Howe, Laura D; Noble, Sian M; Kipping, Ruth R; Jago, Russell

2013-07-24

The Active For Life Year 5 (AFLY5) randomised controlled trial protocol was published in this journal in 2011. It provided a summary analysis plan. This publication is an update of that protocol and provides a detailed analysis plan. This update provides a detailed analysis plan of the effectiveness and cost-effectiveness of the AFLY5 intervention. The plan includes details of how variables will be quality control checked and the criteria used to define derived variables. Details of four key analyses are provided: (a) effectiveness analysis 1 (the effect of the AFLY5 intervention on primary and secondary outcomes at the end of the school year in which the intervention is delivered); (b) mediation analyses (secondary analyses examining the extent to which any effects of the intervention are mediated via self-efficacy, parental support and knowledge, through which the intervention is theoretically believed to act); (c) effectiveness analysis 2 (the effect of the AFLY5 intervention on primary and secondary outcomes 12 months after the end of the intervention) and (d) cost effectiveness analysis (the cost-effectiveness of the AFLY5 intervention). The details include how the intention to treat and per-protocol analyses were defined and planned sensitivity analyses for dealing with missing data. A set of dummy tables are provided in Additional file 1. This detailed analysis plan was written prior to any analyst having access to any data and was approved by the AFLY5 Trial Steering Committee. Its publication will ensure that analyses are in accordance with an a priori plan related to the trial objectives and not driven by knowledge of the data. ISRCTN50133740.

TV Time but Not Computer Time Is Associated with Cardiometabolic Risk in Dutch Young Adults

PubMed Central

Altenburg, Teatske M.; de Kroon, Marlou L. A.; Renders, Carry M.; HiraSing, Remy; Chinapaw, Mai J. M.

2013-01-01

Background TV time and total sedentary time have been positively related to biomarkers of cardiometabolic risk in adults. We aim to examine the association of TV time and computer time separately with cardiometabolic biomarkers in young adults. Additionally, the mediating role of waist circumference (WC) is studied. Methods and Findings Data of 634 Dutch young adults (18–28 years; 39% male) were used. Cardiometabolic biomarkers included indicators of overweight, blood pressure, blood levels of fasting plasma insulin, cholesterol, glucose, triglycerides and a clustered cardiometabolic risk score. Linear regression analyses were used to assess the cross-sectional association of self-reported TV and computer time with cardiometabolic biomarkers, adjusting for demographic and lifestyle factors. Mediation by WC was checked using the product-of-coefficient method. TV time was significantly associated with triglycerides (B = 0.004; CI = [0.001;0.05]) and insulin (B = 0.10; CI = [0.01;0.20]). Computer time was not significantly associated with any of the cardiometabolic biomarkers. We found no evidence for WC to mediate the association of TV time or computer time with cardiometabolic biomarkers. Conclusions We found a significantly positive association of TV time with cardiometabolic biomarkers. In addition, we found no evidence for WC as a mediator of this association. Our findings suggest a need to distinguish between TV time and computer time within future guidelines for screen time. PMID:23460900

Longitudinal Relationships of Fitness, Physical Activity, and Weight Status With Academic Achievement in Adolescents.

PubMed

Suchert, Vivien; Hanewinkel, Reiner; Isensee, Barbara

2016-10-01

To examine associations of cardiorespiratory fitness, physical activity (PA) and weight status with academic achievement 1 year later. In addition, the mediating role of psychological variables was tested. Longitudinal analyses included 1011 German students (M = 14.1 years, SD = 0.6 years). Cardiorespiratory fitness was determined with the 20 m shuttle run test. Compliance with PA guidelines was assessed through questionnaire. Weight status was based on body mass index percentiles. As proxy of academic achievement students' self-reported grades in Mathematics and German in their midterm report were averaged. Mediation analyses were conducted at follow-up testing general self-efficacy, depressed affect, and attention/hyperactivity problems. High levels of cardiorespiratory fitness predicted higher educational attainment (p = .007), while we found no longitudinal association for PA and weight status (p > .253). However, students being insufficiently physically active at baseline but meet PA guidelines at follow-up showed a significant improvement in educational attainment. The cross-sectional association between PA and academic achievement was mediated by students' general self-efficacy. High fitness in adolescence is associated with higher subsequent academic achievement. The promotion of PA might benefit school performance because of enhanced fitness levels in the long-term and positive influences of PA in the shortterm. The association between weight status and educational attainment remains controversial. © 2016, American School Health Association.

Influence of different positive emotions on persuasion processing: a functional evolutionary approach.

PubMed

Griskevicius, Vladas; Shiota, Michelle N; Neufeld, Samantha L

2010-04-01

Much research has found that positive affect facilitates increased reliance on heuristics in cognition. However, theories proposing distinct evolutionary fitness-enhancing functions for specific positive emotions also predict important differences among the consequences of different positive emotion states. Two experiments investigated how six positive emotions influenced the processing of persuasive messages. Using different methods to induce emotions and assess processing, we showed that the positive emotions of anticipatory enthusiasm, amusement, and attachment love tended to facilitate greater acceptance of weak persuasive messages (consistent with previous research), whereas the positive emotions of awe and nurturant love reduced persuasion by weak messages. In addition, a series of mediation analyses suggested that the effects distinguishing different positive emotions from a neutral control condition were best accounted for by different mediators rather than by one common mediator. These findings build upon approaches that link affective valence to certain types of processing, documenting emotion-specific effects on cognition that are consistent with functional evolutionary accounts of discrete positive emotions. Copyright 2010 APA, all rights reserved.

Age and Gender Differences in Emotion Regulation Strategies: Autobiographical Memory, Rumination, Problem Solving and Distraction.

PubMed

Ricarte Trives, Jorge Javier; Navarro Bravo, Beatriz; Latorre Postigo, José Miguel; Ros Segura, Laura; Watkins, Ed

2016-07-18

Our study tested the hypothesis that older adults and men use more adaptive emotion regulatory strategies but fewer negative emotion regulatory strategies than younger adults and women. In addition, we tested the hypothesis that rumination acts as a mediator variable for the effect of age and gender on depression scores. Differences in rumination, problem solving, distraction, autobiographical recall and depression were assessed in a group of young adults (18-29 years) compared to a group of older adults (50-76 years). The older group used more problem solving and distraction strategies when in a depressed state than their younger counterparts (ps .06). Ordinary least squares regression analyses with bootstrapping showed that rumination mediated the association between age, gender and depression scores. These results suggest that older adults and men select more adaptive strategies to regulate emotions than young adults and women with rumination acting as a significant mediator variable in the association between age, gender, and depression.

Psychological Detachment Mediating the Daily Relationship between Workload and Marital Satisfaction

PubMed Central

Germeys, Lynn; De Gieter, Sara

2017-01-01

Scholars already demonstrated that psychologically detaching from work after workhours can diminish or avoid the negative effects of job demands on employees' well-being. In this study, we examined a curvilinear relationship between workload and psychological detachment. Moreover, we investigated the moderating influence of an employee's work-home segmentation preference on the relation between detachment and marital satisfaction. In addition, we applied and extended the stressor-detachment model by examining detachment as a mediator of the relation between workload and marital satisfaction. A total of 136 employees participated in our daily diary survey study during 10 consecutive working days. The results of the Bayesian 2-level path analyses revealed a negative linear and curvilinear relationship between workload and psychological detachment on a daily basis. Daily detachment positively related to marital satisfaction, with one's preference to segment work from home reinforcing this relationship. Moreover, psychological detachment fully mediated the daily relationship between workload and marital satisfaction. Implications for practice and suggestions for future research are discussed. PMID:28101076

Parent training for young Norwegian children with ODD and CD problems: predictors and mediators of treatment outcome.

PubMed

Fossum, Sturla; Mørch, Willy-Tore; Handegård, Bjørn H; Drugli, May B; Larsson, Bo

2009-04-01

Participants were 121 children, aged 4-8 years referred for conduct problems, and their mothers. A parent training intervention was implemented in two outpatient clinics in Norway. Treatment responders were defined as children scoring below a cut-off on the Eyberg Child Behavior Inventory, a score below an optimal cut-off for children in day-care and school as reported by teachers, in addition to a 30% reduction or greater in observed negative parenting. Self-reported parenting practices were explored as potential mediators. The results of logistic regression analyses showed that high levels of maternal stress, clinical levels of ADHD, and being a girl predicted a poorer outcome in conduct problems at home, while pretreatment clinical levels of ADHD predicted a poorer outcome as perceived by the teachers. Harsh and inconsistent parental disciplining emerged as significant partial mediators of changes in conduct problems, highlighting the importance of altering parenting practices to modify young children's conduct problems.

Coping Mediates the Association Between Marital Instability and Depression, but Not Marital Satisfaction and Depression

PubMed Central

Fink, Brandi C.; Shapiro, Alyson F.

2014-01-01

The association between marital discord and depression is well established. Marital discord is hypothesized to be a stressful life event that would evoke one’s efforts to cope with it. In an effort to further understand the nature of this association, the current study investigated coping as a mediating variable between marital dissatisfaction and depression and between marital instability and depression. Both marital dissatisfaction and instability, reflecting orthogonal dimensions of marital discord, were included in the model examined to elucidate a more complete picture of marital functioning. Structural Equation Modeling analyses revealed that coping mediated the association between marital instability and depression, but not marital dissatisfaction and depression, suggesting that coping traditionally considered adaptive for individuals in the context of controllable stressors may not be adaptive in the context of couple relationship instability. The findings also have implications for interventions focusing on decreasing maladaptive coping strategies in couples presenting for marital therapy or depression in addition to efforts directed at improving marital quality. PMID:25032063

Relations of mother's sense of coherence and childrearing style with child's social skills in preschoolers.

PubMed

Hosokawa, Rikuya; Katsura, Toshiki; Shizawa, Miho

2017-01-01

We examined the relationships between mothers' sense of coherence (SOC) and their child's social skills development among preschool children, and how this relationship is mediated by mother's childrearing style. Mothers of 1341 Japanese children, aged 4-5 years, completed a self-report questionnaire on their SOC and childrearing style. The children's teachers evaluated their social skills using the social skills scale (SSS), which comprises three factors: cooperation, self-control, and assertion. Path analyses revealed that the mother's childrearing mediated the positive relationship between mother's SOC and the cooperation, self-control, and assertiveness aspects of children's social skills. Additionally, there was a significant direct path from mother's SOC to the self-control component of social skills. These findings suggest that mother's SOC may directly as well as indirectly influence children's social skills development through the mediating effect of childrearing. The results offer preliminary evidence that focusing on support to improve mothers' SOC may be an efficient and effective strategy for improving children's social skills development.

The Importance of Emotional Intelligence and Cognitive Style in Institutionalized Older Adults' Quality of Life.

PubMed

Luque-Reca, Octavio; Pulido-Martos, Manuel; Lopez-Zafra, Esther; Augusto-Landa, José M

2018-01-01

Despite previous evidence showing a positive relationship between emotional intelligence (EI) and quality of life (QoL), associating older adults' emotional processing with several health indicators, few studies have explored both the IE and the a mechanisms through which they affect QoL. This cross-sectional study analyzes the mediator role of optimistic and pessimistic cognitive styles in the relationship between perceived EI (PEI) and QoL in 115 institutionalized older adults from Southern Spain. Regression analyses showed, after controlling for cognitive style, that PEI predicted a significant percentage of variance in: Health (β = .25, p < .01), Functional abilities (β = .20, p < .05), Activity and leisure (β = .17, p < .05) and Life satisfaction (β = .21, p < .05). Additionally, multiple mediation analysis revealed that cognitive style partially mediated the relationship between PEI and Health, Activity and leisure and Life satisfaction. Thus, PEI could promote personal but not external or environmental QoL aspects, highlighting the importance of developing emotional skills for healthy aging.

Dieting in Moderation: The Role of Dietary Restraint in the Relationship between Body Dissatisfaction and Psychological Well-being.

PubMed

Tiggemann, M

1997-10-01

This study demonstrates the substantial conceptual consequences in distinguishing a variable's role as a moderator as opposed to a mediator. In particular, the study investigates the role of dietary restraint in the relationship between body dissatisfaction and psychological well-being. Path analyses showed that, in addition to its mediating role, dietary restraint has a moderating role, such that there is a stronger relationship between body dissatisfaction and psychological well-being when dietary restraint is high than when dietary restraint is low. In contrast, gender had only a direct effect on weight dissatisfaction. It was concluded that the same processes occur for both men and for women, whereby it is the individuals who diet who suffer loss of psychological well-being.

Peer substance use as a mediator between early pubertal timing and adolescent substance use: longitudinal associations and moderating effect of maltreatment.

PubMed

Negriff, Sonya; Trickett, Penelope K

2012-11-01

Early pubertal timing has received considerable empirical support as a risk for adolescent substance use. However, few studies have examined the mediators linking these variables. Therefore, the aims of this study were (1) to examine peer substance use as a mediator between pubertal timing and adolescent substance use longitudinally and (2) to test gender and maltreatment experience as moderators of the mediational model. Data were obtained from time 1, 2, and 3 of a longitudinal study of maltreatment and development. At time 1 the sample was comprised of 303 maltreated and 151 comparison children aged 9-13 years (213 females and 241 males). Longitudinal mediation was tested using structural equation modeling and moderating effects were tested using multiple group analysis. Peer substance use mediated the relationship between early pubertal timing and later adolescent substance use for the total sample. Moderation analyses indicated this significant indirect effect did not differ for males and females. However, it did differ for maltreated versus comparison adolescents with the mediational effect only remaining significant for the comparison group. This is one of the first studies to examine peer substance use as a mediator of pubertal timing and adolescent substance use using a longitudinal design. Early maturing males are at equal risk to early maturing females for interacting with peers that may draw them into substance use. Additionally, the findings indicate that while peers are mediators for comparison adolescents a different mechanism may link early puberty to substance use for maltreated adolescents. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Mediation Analysis with Survival Outcomes: Accelerated Failure Time vs. Proportional Hazards Models.

PubMed

Gelfand, Lois A; MacKinnon, David P; DeRubeis, Robert J; Baraldi, Amanda N

2016-01-01

Survival time is an important type of outcome variable in treatment research. Currently, limited guidance is available regarding performing mediation analyses with survival outcomes, which generally do not have normally distributed errors, and contain unobserved (censored) events. We present considerations for choosing an approach, using a comparison of semi-parametric proportional hazards (PH) and fully parametric accelerated failure time (AFT) approaches for illustration. We compare PH and AFT models and procedures in their integration into mediation models and review their ability to produce coefficients that estimate causal effects. Using simulation studies modeling Weibull-distributed survival times, we compare statistical properties of mediation analyses incorporating PH and AFT approaches (employing SAS procedures PHREG and LIFEREG, respectively) under varied data conditions, some including censoring. A simulated data set illustrates the findings. AFT models integrate more easily than PH models into mediation models. Furthermore, mediation analyses incorporating LIFEREG produce coefficients that can estimate causal effects, and demonstrate superior statistical properties. Censoring introduces bias in the coefficient estimate representing the treatment effect on outcome-underestimation in LIFEREG, and overestimation in PHREG. With LIFEREG, this bias can be addressed using an alternative estimate obtained from combining other coefficients, whereas this is not possible with PHREG. When Weibull assumptions are not violated, there are compelling advantages to using LIFEREG over PHREG for mediation analyses involving survival-time outcomes. Irrespective of the procedures used, the interpretation of coefficients, effects of censoring on coefficient estimates, and statistical properties should be taken into account when reporting results.

Understanding the connection between self-esteem and aggression: The mediating role of emotion dysregulation.

PubMed

Garofalo, Carlo; Holden, Christopher J; Zeigler-Hill, Virgil; Velotti, Patrizia

2016-01-01

The purpose of the present study was to extend previous knowledge concerning the link between self-esteem and aggression by examining the mediating role of emotion dysregulation among offenders and community participants. A sample of 153 incarcerated violent offenders and a community sample of 197 individuals completed self-report measures of self-esteem level, emotion dysregulation, and trait aggression. Offenders reported lower levels of self-esteem than community participants, as well as greater levels of emotional nonacceptance and hostility. Bootstrapping analyses were performed to test whether emotion dysregulation mediated the association between self-esteem level and aggression. In the offender sample, mediation models were significant for three of the four aspects of trait aggression that were considered. Emotion dysregulation fully mediated the links that low self-esteem had with physical aggression, anger, and hostility. The same pattern (with the addition of full mediation for verbal aggression) was confirmed in the community sample. Our findings suggest that emotion dysregulation may play an important role in the connection between low self-esteem and aggression. Alternative models of the associations among these variables were tested and discussed. As a whole, the present results are consistent with those of other studies and suggest that it may be beneficial to include emotion regulation modules as part of prevention and treatment programs for violent offenders. © 2015 Wiley Periodicals, Inc.

Hopelessness Mediates the Relation between Insomnia and Suicidal Ideation

PubMed Central

Woosley, Julie A.; Lichstein, Kenneth L.; Taylor, Daniel J.; Riedel, Brant W.; Bush, Andrew J.

2014-01-01

Introduction: A growing body of literature indicates that insomnia is related to suicidality. However, the mechanism through which insomnia correlates with suicide risk is unclear. The goal of the present research was to determine whether hopelessness, a robust predictor of suicidality, mediates the relation between insomnia and suicidal ideation (SI). Methods: The present study used archival data from community-dwelling adults. Participants (n = 766) completed a Health Survey, two weeks of daily sleep diaries, and five measures of daytime functioning, including the Beck Depression Inventory (BDI). BDI item 2 was used to assess hopelessness, and BDI item 9 was used to assess SI. Criteria from the DSM-5 as well as quantitative criteria were used to identify participants with insomnia (n = 135). Results: The analyses revealed that hopelessness is a significant mediator of the relation between insomnia and SI. After adding depression as an additional mediator, hopelessness remained a significant predictor of SI. Conclusion: The present research suggests the need for clinicians to routinely screen clients who have insomnia for hopelessness and SI, and to treat hopelessness when it is present. Further research should address the limitations in this sample and should also consider other potential mediators of the insomnia-SI link. Citation: Woosley JA, Lichstein KL, Taylor DJ, Riedel BW, Bush AJ. Hopelessness mediates the relation between insomnia and suicidal ideation. J Clin Sleep Med 2014;10(11):1223-1230. PMID:25325598

Forms of Mediation: The Case of Interpreter-Mediated Interactions in Medical Systems

ERIC Educational Resources Information Center

Baraldi, Claudio

2009-01-01

This paper analyses the forms of mediation in interlinguistic interactions performed in Italian healthcare services and in contexts of migration. The literature encourages dialogic transformative mediation, empowering participants' voices and changing cultural presuppositions in social systems. It may be doubtful, however, whether mediation can…

Does perfectionism in bipolar disorder pedigrees mediate associations between anxiety/stress and mood symptoms?

PubMed

Corry, Justine; Green, Melissa; Roberts, Gloria; Fullerton, Janice M; Schofield, Peter R; Mitchell, Philip B

2017-10-06

Bipolar disorder (BD) and the anxiety disorders are highly comorbid. The present study sought to examine perfectionism and goal attainment values as potential mechanisms of known associations between anxiety, stress and BD symptomatology. Measures of perfectionism and goal attainment values were administered to 269 members of BD pedigrees, alongside measures of anxiety and stress, and BD mood symptoms. Regression analyses were used to determine whether perfectionism and goal attainment values were related to depressive and (hypo)manic symptoms; planned mediation models were then used to test the potential for perfectionism to mediate associations between anxiety/stress and BD symptoms. Self-oriented perfectionism was associated with chronic depressive symptoms; socially-prescribed perfectionism was associated with chronic (hypo)manic symptoms. Self-oriented perfectionism mediated relationships between anxiety/stress and chronic depressive symptoms even after controlling for chronic hypomanic symptoms. Similarly, socially-prescribed perfectionism mediated associations between anxiety/stress and chronic hypomanic symptoms after controlling for chronic depressive symptoms. Goal attainment beliefs were not uniquely associated with chronic depressive or (hypo)manic symptoms. Cognitive styles of perfectionism may explain the co-occurrence of anxiety and stress symptoms and BD symptoms. Psychological interventions for anxiety and stress symptoms in BD might therefore address perfectionism in attempt to reduce depression and (hypo)manic symptoms in addition to appropriate pharmacotherapy.

The need for cognition mediates and moderates the association between depressive symptoms and impaired effortful control.

PubMed

Nishiguchi, Yuki; Takano, Keisuke; Tanno, Yoshihiko

2016-07-30

Previous studies have shown a negative correlation between effortful control (EC) and depressive symptoms. EC is defined as the efficiency of executive attention, which may be reduced by the attentional impairment associated with depression. However, the mechanism underlying this correlation is still unclear. We investigated the relationship between EC and depressive symptoms with the hypothesis that cognitive motivation, or need for cognition (NfC), is a possible mediator of this relationship. Participants were 178 Japanese university students. Each completed the Zung Self-Rating Depression Scale, Effortful Control Scale, and Need for Cognition Scale at baseline and follow-up assessments. Supporting our hypothesis, mediation analyses revealed a significant indirect effect of depressive symptoms on EC that was mediated by NfC. In addition, our data demonstrated a direct effect of depressive symptoms on EC. Longitudinal analysis indicated that an increase in depression and a decrease in NfC occurred synchronously, while NfC predicted an increase in EC over time. Depressive symptoms may decrease executive functioning and effortful control both directly and indirectly, the latter effect being mediated by motivation. These findings imply that a motivational deficit may partially explain the decreased EC found in people suffering from depression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Childhood stress and birth timing among African American women: Cortisol as biological mediator.

PubMed

Gillespie, Shannon L; Christian, Lisa M; Alston, Angela D; Salsberry, Pamela J

2017-10-01

Preterm birth (PTB) occurs among 1:11U.S. white women and 1:7.5 African American women and is a significant driver of racial disparities in infant mortality. Maternal stress is the most common clinical phenotype underlying spontaneous PTB. Specific patterns of stress and biological mediators driving PTB remain unclear. We examined the effect of childhood stress on birth timing among African American women and evaluated maternal cortisol elevation as a biological mediator. A prospective observational design was employed, with a single study visit at 28-32 weeks gestation and medical record review. The Stress and Adversity Inventory was administered, which provides a comprehensive estimate of childhood stress, stress in adulthood, and five core characteristic subscales (interpersonal loss, physical danger, humiliation, entrapment, role disruption). Venipuncture was performed between 11:00am and 4:00pm and plasma cortisol quantified by ELISA. Analyses controlled for stress in adulthood. Among a final sample of 89, cumulative childhood stress predicted birth timing (p=0.01). The association was driven by stress related to interpersonal loss and physical danger, with support for maternal cortisol as a biological mediator (ab=0.02, 95% CI [0.001, 0.045]; ab=0.02, 95% CI [0.001, 0.043], respectively). Results were similar, overall, in sub-group analyses among spontaneously laboring women (n=53); however, role disruption arose as an additional predictor, as mediated by cortisol elevations (ab=0.03, 95% CI [0.005, 0.074]). Of note, cortisol was no longer supported as a mediator linking physical danger to birth timing after adjusting for sleep quality and hours awake prior to venipuncture (ab=0.02, 95% CI [-0.0001, 0.046]). We provide preliminary evidence that, independent of stress in adulthood, childhood stress of specific core characteristics may shape birth timing, with cortisol elevation as a biological mediator. Further investigation is warranted and may bolster the development of biologically-informed screening tools for the prediction and targeted prevention of stress-related PTB. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Mediating Role of Emotion Dysregulation in the Relations Between Childhood Trauma History and Adult Attachment and Borderline Personality Disorder Features: A Study of Italian Nonclinical Participants.

PubMed

Fossati, Andrea; Gratz, Kim L; Somma, Antonella; Maffei, Cesare; Borroni, Serena

2016-10-01

In order to evaluate if emotion dysregulation significantly mediates the relationships between childhood abuse and adult attachment and borderline personality disorder features, 354 community Italian adults were administered the Borderline Personality Inventory (Leichsenring, 1999a), the Difficulties in Emotion Regulation Scale (Gratz & Roemer, 2004), the Child Abuse and Trauma Scale (Sanders & Becker-Lausen, 1995), and the Attachment Style Questionnaire (Feeney, Noller, & Hanrahan, 1994). Hierarchical regression analyses showed that both childhood abuse and adult attachment were positively associated with emotion dysregulation and borderline personality features; however, only emotional abuse and the attachment dimension of need for approval were common predictors of both dependent variables. No significant interaction effects were detected in regression analyses. Mediation analyses provided support for partial mediation, revealing a significant mediating role of emotion dysregulation in the relationships between both emotional abuse and need for approval and borderline personality features in this community sample.

Burnout and connectedness in the job demands-resources model: studying palliative care volunteers and their families.

PubMed

Huynh, Jasmine-Yan; Winefield, Anthony H; Xanthopoulou, Despoina; Metzer, Jacques C

2012-09-01

This study examined the role of burnout and connectedness in the job demands-resources (JD-R) model among palliative care volunteers. It was hypothesized that (a) exhaustion mediates the relationship between demands and depression, and between demands and retention; (b) cynicism mediates the relationship between resources and retention; and (c) connectedness mediates the relationship between resources and retention. Hypotheses were tested in 2 separate analyses: structural equation modeling (SEM) and path analyses. The first was based on volunteer self-reports (N = 204), while the second analysis concerned matched data from volunteers and their family members (N = 99). While strong support was found for cynicism and connectedness as mediators in both types of analyses, this was not altogether the case for exhaustion. Implications of these findings for the JD-R model and volunteer organizations are discussed.

Chronotype and depressive symptoms in students: An investigation of possible mechanisms.

PubMed

Van den Berg, Julia F; Kivelä, Liia; Antypa, Niki

2018-05-15

Individuals with an evening chronotype are at increased risk of experiencing emotional problems, including depressive symptoms. However, the mechanisms underlying these associations remain unclear. The present study aimed to determine whether poor sleep quality, substance use and cognitive emotion regulation difficulties - which have been implicated in the etiology of depression - mediate the relationship between chronotype and depressive symptoms in a student sample, which was assessed cross-sectionally and after 1 year. A total of 742 Dutch students (75% women, mean age 21.4 ± 2.9 years) completed the Quick Inventory of Depressive Symptomatology, the Morningness-Eveningness Questionnaire, the Pittsburgh Sleep Quality Index, a questionnaire assessing alcohol, caffeine, tobacco and cannabis use, the Cognitive Emotion Regulation Questionnaire and the Behavioral Inhibition/Activation Scale. A subsample (n = 115) was assessed 1 year later with the same questionnaires. Cross-sectional analyses showed that evening chronotype was associated with more depressive symptoms, adjusted for age and gender (β = -0.082, p = 0.028). The relationship between eveningness and depressive symptoms was mediated by sleep quality, alcohol consumption and the cognitive emotion regulation strategies of self-blame and positive reappraisal. In longitudinal analyses, eveningness at baseline predicted more depressive symptoms at follow-up, adjusted for age and gender (β = -0.29, p = 0.002); after additional adjustment for baseline depressive symptoms, chronotype remained a significant predictor of depressive symptoms at T2 (β = -0.16, t = -2.01, p = 0.047). Only poor sleep quality at follow-up was a significant mediator of this relationship. Even though the effect is small in terms of explained variance, eveningness is related to depressive symptoms and this relationship is mediated by poor sleep quality, also in a prospective design. Self-blame and reduced positive reappraisal are correlated with eveningness. Further research is needed to assess the efficacy of chronotherapeutic interventions for the prevention of depression, in addition to sleep education and cognitive approaches.

Trauma exposure and the mediating role of posttraumatic stress on somatic symptoms in civilian war victims.

PubMed

Morina, Naser; Schnyder, Ulrich; Klaghofer, Richard; Müller, Julia; Martin-Soelch, Chantal

2018-04-10

It has been well documented that the exposure to war has a negative effect on the psychological health of civilian. However, little is known on the impact of war exposure on the physical health of the civilian population. In addition, the link between trauma exposure and somatic symptoms remain poorly understood. This cross-sectional study examined levels of somatic symptoms in the aftermath of war, and the mediating role of posttraumatic stress symptoms in the relationship between trauma exposure and somatic symptoms. Civilian war survivors (N = 142) from Kosovo were assessed for potentially traumatic events, posttraumatic stress symptoms, and somatic symptoms. Data were analyzed using mediation analyses. Posttraumatic stress disorder (PTSD) symptoms were categorized based on King's four factor model (Psychol Assessment. 10: 90-96, 1998). Participants reported on average more than 5 types of traumatic exposure. The cut-off indicative for PTSD was exceeded by 26.1% of participants. Symptom levels of PTSD were associated with somatic symptoms. The relationship between trauma exposure and somatic symptoms was partly mediated by the active avoidance and hyperarousal symptom clusters of PTSD. Active avoidance and hyperarousal symptoms seem to play a key role in traumatized people suffering from somatic symptoms.

Social Adversity and Antisocial Behavior: Mediating Effects of Autonomic Nervous System Activity.

PubMed

Fagan, Shawn E; Zhang, Wei; Gao, Yu

2017-11-01

The display of antisocial behaviors in children and adolescents has been of interest to criminologists and developmental psychologists for years. Exposure to social adversity is a well-documented predictor of antisocial behavior. Additionally, measures of autonomic nervous system (ANS) activity, including heart rate variability (HRV), pre-ejection period (PEP), and heart rate, have been associated with antisocial behaviors including rule-breaking and aggression. Social neuroscience research has begun to investigate how neurobiological underpinnings affect the relationship between social adversity and antisocial/psychopathic behavior in children and adolescents. This study investigated the potential mediating effects of ANS activity on the relationship between social adversity and antisocial behavior in a group of 7- to 10-year-old children from the community (N = 339; 48.2% male). Moderated multiple mediation analyses revealed that low resting heart rate, but not PEP or HRV, mediated the relationship between social adversity and antisocial behavior in males only. Social adversity but not ANS measures were associated with antisocial behavior in females. Findings have implications for understanding the neural influences that underlie antisocial behavior, illustrate the importance of the social environment regarding the expression of these behaviors, and highlight essential gender differences.

Concanavalin A-mediated polyclonal helper assay of normal thymocytes and its use for the analysis of ontogeny.

PubMed

Kina, T; Nishikawa, S; Amagai, T; Katsura, Y

1987-01-01

A concanavalin A (Con A)-mediated polyclonal helper assay system was established by using the thymus cells or splenic T cells as a source of helper T cells. When splenic B cells were cocultured with thymus cells or splenic Lyt-2- T cells in the presence of an optimal dose of Con A, B Cells were polyclonally activated and differentiated into immunoglobulin-secreting cells. This Con A-mediated helper activity was completely inhibited by the addition of alpha-methyl-D-mannoside and could not be substituted by culture supernatant of Con A-stimulated thymocytes or splenic T cells. Almost all the activity of the thymus cells was carried by peanut agglutinin low binding population. Genetic restriction between T and B cells was not observed in this helper function. In ontogeny, Con A-mediated helper activity in the thymus was first detected at a few days after birth and reached the adult level at about 1 week of age. The polyclonal helper assay system developed in the present study provides a sensitive system to analyse the helper function of thymus cells and also to delineate the early phase of the differentiation of helper T cell population.

Relationship between adverse childhood experiences and homelessness and the impact of axis I and II disorders.

PubMed

Roos, Leslie E; Mota, Natalie; Afifi, Tracie O; Katz, Laurence Y; Distasio, Jino; Sareen, Jitender

2013-12-01

We investigated the links between homelessness associated with serious mental and physical healthy disparities and adverse childhood experiences (ACEs) in nationally representative data, with Axis I and II disorders as potential mediators. We examined data from the National Epidemiologic Survey of Alcohol and Related Conditions in 2001-2002 and 2004-2005, and included 34,653 participants representative of the noninstitutionalized US population who were 20 years old or older. We studied the variables related to 4 classes of Axis I disorders, all 10 Axis II personality disorders, a wide range of ACEs, and a lifetime history of homelessness. Analyses revealed high prevalences of each ACE in individuals experiencing lifetime homelessness (17%-60%). A mediation model with Axis I and II disorders determined that childhood adversities were significantly related to homelessness through direct effects (adjusted odd ratios = 2.04, 4.24) and indirect effects, indicating partial mediation. Population attributable fractions were also reported. Although Axis I and II disorders partially mediated the relationship between ACEs and homelessness, a strong direct association remained. This novel finding has implications for interventions and policy. Additional research is needed to understand relevant causal pathways.

Cognitive behavioural therapy for MS-related fatigue explained: A longitudinal mediation analysis.

PubMed

van den Akker, L E; Beckerman, H; Collette, E H; Knoop, H; Bleijenberg, G; Twisk, J W; Dekker, J; de Groot, V

2018-03-01

Cognitive behavioural therapy (CBT) effectively reduces fatigue directly following treatment in patients with Multiple Sclerosis (MS), but little is known about the process of change during and after CBT. Additional analysis of a randomized clinical trial. To investigate which psychological factors mediate change in fatigue during and after CBT. TREFAMS-CBT studied the effectiveness of a 16-week CBT treatment for MS-related fatigue. Ninety-one patients were randomized (44 to CBT, 47 to the MS-nurse consultations). Mediation during CBT treatment was studied using assessments at baseline, 8 and 16weeks. Mediation of the change in fatigue from post-treatment to follow-up was studied separately using assessments at 16, 26 and 52weeks. Proposed mediators were: changes in illness cognitions, general self-efficacy, coping styles, daytime sleepiness, concentration and physical activity, fear of disease progression, fatigue perceptions, depression and physical functioning. Mediators were separately analysed according to the product-of-coefficients approach. Confidence intervals were calculated with a bootstrap procedure. During treatment the decrease in fatigue brought on by CBT was mediated by improved fatigue perceptions, increased physical activity, less sleepiness, less helplessness, and improved physical functioning. Post-treatment increases in fatigue levels were mediated by reduced physical activity, reduced concentration, and increased sleepiness. These results suggests that focusing on improving fatigue perceptions, perceived physical activity, daytime sleepiness, helplessness, and physical functioning may further improve the effectiveness of CBT for fatigue in patients with MS. Maintenance of treatment effects may be obtained by focusing on improving physical activity, concentration and sleepiness. Copyright © 2018 Elsevier Inc. All rights reserved.

Does Parental Mediation of Media Influence Child Outcomes? A Meta-Analysis on Media Time, Aggression, Substance Use, and Sexual Behavior

ERIC Educational Resources Information Center

Collier, Kevin M.; Coyne, Sarah M.; Rasmussen, Eric E.; Hawkins, Alan J.; Padilla-Walker, Laura M.; Erickson, Sage E.; Memmott-Elison, Madison K.

2016-01-01

The current study examined how parental mediation of media (restrictive mediation, active mediation, and coviewing) influenced child outcomes. Three meta-analyses, 1 for each type of mediation, were conducted on a total of 57 studies. Each analysis assessed the effectiveness of parental mediation on 4 pertinent child outcomes: media use,…

Three WRKY transcription factors additively repress abscisic acid and gibberellin signaling in aleurone cells.

PubMed

Zhang, Liyuan; Gu, Lingkun; Ringler, Patricia; Smith, Stanley; Rushton, Paul J; Shen, Qingxi J

2015-07-01

Members of the WRKY transcription factor superfamily are essential for the regulation of many plant pathways. Functional redundancy due to duplications of WRKY transcription factors, however, complicates genetic analysis by allowing single-mutant plants to maintain wild-type phenotypes. Our analyses indicate that three group I WRKY genes, OsWRKY24, -53, and -70, act in a partially redundant manner. All three showed characteristics of typical WRKY transcription factors: each localized to nuclei and yeast one-hybrid assays indicated that they all bind to W-boxes, including those present in their own promoters. Quantitative real time-PCR (qRT-PCR) analyses indicated that the expression levels of the three WRKY genes varied in the different tissues tested. Particle bombardment-mediated transient expression analyses indicated that all three genes repress the GA and ABA signaling in a dosage-dependent manner. Combination of all three WRKY genes showed additive antagonism of ABA and GA signaling. These results suggest that these WRKY proteins function as negative transcriptional regulators of GA and ABA signaling. However, different combinations of these WRKY genes can lead to varied strengths in suppression of their targets. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Using Self-regulation to Successfully Overcome the Negotiation Disadvantage of Low Power

PubMed Central

Jäger, Andreas; Loschelder, David D.; Friese, Malte

2017-01-01

A plethora of studies has demonstrated that low-power negotiators attain lower outcomes compared to high-power negotiators. We argue that this low-power disadvantage can be conceptualized as impaired goal attainment and that self-regulation can help to overcome it. Three experiments tested this assertion. In Study 1, low-power negotiators attained lower profits compared to their high-power opponents in a face-to-face negotiation. Negotiators who set themselves goals and those who additionally formed if-then plans prior to the negotiation overcame the low-power disadvantage. Studies 2 and 3 replicated these effects in computer-mediated negotiations: Low-power negotiators conceded more than high-power negotiators. Again, setting goals and forming additional if-then plans helped to counter the power disadvantage. Process analyses revealed that negotiators’ concession-making at the start of the negotiation mediated both the low-power disadvantage and the beneficial effects of self-regulation. The present findings show how the low-power disadvantage unfolds in negotiations and how self-regulatory techniques can help to overcome it. PMID:28382005

Using Self-regulation to Successfully Overcome the Negotiation Disadvantage of Low Power.

PubMed

Jäger, Andreas; Loschelder, David D; Friese, Malte

2017-01-01

A plethora of studies has demonstrated that low-power negotiators attain lower outcomes compared to high-power negotiators. We argue that this low-power disadvantage can be conceptualized as impaired goal attainment and that self-regulation can help to overcome it. Three experiments tested this assertion. In Study 1, low-power negotiators attained lower profits compared to their high-power opponents in a face-to-face negotiation. Negotiators who set themselves goals and those who additionally formed if-then plans prior to the negotiation overcame the low-power disadvantage. Studies 2 and 3 replicated these effects in computer-mediated negotiations: Low-power negotiators conceded more than high-power negotiators. Again, setting goals and forming additional if-then plans helped to counter the power disadvantage. Process analyses revealed that negotiators' concession-making at the start of the negotiation mediated both the low-power disadvantage and the beneficial effects of self-regulation. The present findings show how the low-power disadvantage unfolds in negotiations and how self-regulatory techniques can help to overcome it.

Genome-Wide Analyses of Calcium Sensors Reveal Their Involvement in Drought Stress Response and Storage Roots Deterioration after Harvest in Cassava.

PubMed

Hu, Wei; Yan, Yan; Tie, Weiwei; Ding, Zehong; Wu, Chunlai; Ding, Xupo; Wang, Wenquan; Xia, Zhiqiang; Guo, Jianchun; Peng, Ming

2018-04-19

Calcium (Ca 2+ ) plays a crucial role in plant development and responses to environmental stimuli. Currently, calmodulins (CaMs), calmodulin-like proteins (CMLs), and calcineurin B-like proteins (CBLs), such as Ca 2+ sensors, are not well understood in cassava ( Manihot esculenta Crantz), an important tropical crop. In the present study, 8 CaMs, 48 CMLs, and 9 CBLs were genome-wide identified in cassava, which were divided into two, four, and four groups, respectively, based on evolutionary relationship, protein motif, and gene structure analyses. Transcriptomic analysis revealed the expression diversity of cassava CaMs-CMLs-CBLs in distinct tissues and in response to drought stress in different genotypes. Generally, cassava CaMs-CMLs-CBLs showed different expression profiles between cultivated varieties (Arg7 and SC124) and wild ancestor (W14) after drought treatment. In addition, numerous CaMs-CMLs-CBLs were significantly upregulated at 6 h, 12 h, and 48 h after harvest, suggesting their possible role during storage roots (SR) deterioration. Further interaction network and co-expression analyses suggested that a CBL-mediated interaction network was widely involved in SR deterioration. Taken together, this study provides new insights into CaMs-CMLs-CBLs-mediated drought adaption and SR deterioration at the transcription level in cassava, and identifies some candidates for the genetic improvement of cassava.

Mediation Analysis with Survival Outcomes: Accelerated Failure Time vs. Proportional Hazards Models

PubMed Central

Gelfand, Lois A.; MacKinnon, David P.; DeRubeis, Robert J.; Baraldi, Amanda N.

2016-01-01

Objective: Survival time is an important type of outcome variable in treatment research. Currently, limited guidance is available regarding performing mediation analyses with survival outcomes, which generally do not have normally distributed errors, and contain unobserved (censored) events. We present considerations for choosing an approach, using a comparison of semi-parametric proportional hazards (PH) and fully parametric accelerated failure time (AFT) approaches for illustration. Method: We compare PH and AFT models and procedures in their integration into mediation models and review their ability to produce coefficients that estimate causal effects. Using simulation studies modeling Weibull-distributed survival times, we compare statistical properties of mediation analyses incorporating PH and AFT approaches (employing SAS procedures PHREG and LIFEREG, respectively) under varied data conditions, some including censoring. A simulated data set illustrates the findings. Results: AFT models integrate more easily than PH models into mediation models. Furthermore, mediation analyses incorporating LIFEREG produce coefficients that can estimate causal effects, and demonstrate superior statistical properties. Censoring introduces bias in the coefficient estimate representing the treatment effect on outcome—underestimation in LIFEREG, and overestimation in PHREG. With LIFEREG, this bias can be addressed using an alternative estimate obtained from combining other coefficients, whereas this is not possible with PHREG. Conclusions: When Weibull assumptions are not violated, there are compelling advantages to using LIFEREG over PHREG for mediation analyses involving survival-time outcomes. Irrespective of the procedures used, the interpretation of coefficients, effects of censoring on coefficient estimates, and statistical properties should be taken into account when reporting results. PMID:27065906

Assessing the relationship between quality of life and behavioral activation using the Japanese Behavioral Activation for Depression Scale-Short Form.

PubMed

Shudo, Yusuke; Yamamoto, Tatsuya

2017-01-01

Quality of life (QOL) is an important health-related concept. Identifying factors that affect QOL can help develop and improve health-promotion interventions. Previous studies suggest that behavioral activation fosters subjective QOL, including well-being. However, the mechanism by which behavioral activation improves QOL is not clear. Considering that QOL improves when depressive symptoms improve post-treatment and that behavioral activation is an effective treatment for depression, it is possible that behavioral activation affects QOL indirectly rather than directly. To clarify the mechanism of the influence of behavioral activation on QOL, it is necessary to examine the relationships between factors related to behavioral activation, depressive symptoms, and QOL. Therefore, we attempted to examine the relationship between these factors. Participants comprised 221 Japanese undergraduate students who completed questionnaires on behavioral activation, QOL, and depressive symptoms: the Japanese versions of the Behavioral Activation for Depression Scale-Short Form (BADS-SF), WHO Quality of Life-BREF (WHOQOL-26), and Center for Epidemiologic Studies Depression Scale (CES-D). The BADS-SF comprises two subscales, Activation and Avoidance, and the WHOQOL-26 measures overall QOL and four domains, Physical Health, Psychological Health, Social Relationships, and Environment. Mediation analyses were conducted with BADS-SF activation and avoidance as independent variables, CES-D as a mediator variable, and each WHO-QOL as an outcome variable. Results indicated that depression completely mediated the relationship between Avoidance and QOL, and partially mediated the relationship between Activation and QOL. In addition, analyses of each domain of QOL showed that Activation positively affected all aspects of QOL directly and indirectly, but Avoidance had a negative influence on only part of QOL mainly through depression. The present study provides behavioral activation strategies aimed at QOL enhancement.

Intergenerational continuity in high conflict family environments

PubMed Central

Rothenberg, W. Andrew; Hussong, Andrea M.; Chassin, Laurie

2016-01-01

In the current study, we examined continuity in conflict across generations and explored potential mediators and moderators that could explain this continuity. We followed 246 targets from adolescence to adulthood and examined family conflict as reported by multiple reporters in targets' family of origin and current families. Results showed that conflict in the current family was strongly correlated with that of the family of origin in women but not in men. Continuity in family conflict across generations was mediated by patterns of elevated adolescent externalizing behavior in members of the second generation (G2). Additionally, analyses revealed an interaction between both G2 partners' externalizing behavior such that if one partner in the G2 family demonstrated high levels of externalizing behavior, elevated levels of family conflict resulted. Potential explanations and implications of these findings are considered. PMID:26018605

Evaluating lipid mediator structural complexity using ion mobility spectrometry combined with mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyle, Jennifer E.; Aly, Noor; Zheng, Xueyun

Lipid mediators (LMs) are broadly defined as a class of bioactive lipophilic molecules that regulate cell-to-cell communication events with many having a strong correlation with various human diseases and conditions. LMs are usually analyzed with liquid chromatography and mass spectrometry (LC-MS), but their numerous isomers greatly complicate the measurements with essentially identical fragmentation spectra and LC separations not always sufficient for distinguishing the features. In this work, we characterized LMs having specific categories using ion mobility spectrometry coupled with mass spectrometry (IMS-MS). The IMS collision cross sections and MS m/z values displayed distinct trends for each LM category studied. LC-IMS-MSmore » analyses on flu infected mouse tissue samples also illustrated the presence of additional LM species not in our databases.« less

An examination of the relationship between anger and suicide risk through the lens of the interpersonal theory of suicide.

PubMed

Hawkins, Kirsten A; Hames, Jennifer L; Ribeiro, Jessica D; Silva, Caroline; Joiner, Thomas E; Cougle, Jesse R

2014-03-01

Research has implicated a relationship between anger and suicidality, though underlying mechanisms remain unclear. The current study examined this relationship through the lens of the interpersonal theory of suicide (ITS). According to the ITS, individuals who experience thwarted belongingness, perceived burdensomeness, and elevated acquired capability for suicide are at increased risk for death by suicide. The relationships between anger and these variables were examined and these variables were examined as potential mediators between anger and suicidal ideation and behavior. Additionally, exposure to painful and provocative events was examined as a potential mediator between anger and acquired capability. As part of intake at a community mental health clinic, 215 outpatients completed questionnaires assessing depression, suicidal ideation, anger, perceived burdensomeness, thwarted belongingness, and acquired capability. Regression analyses revealed unique relationships between anger and both thwarted belongingness and perceived burdensomeness, covarying for depression. The association between anger and acquired capability trended toward significance. The links between anger and suicidal ideation and behavior were fully mediated by thwarted belongingness and perceived burdensomeness, but this effect was driven by perceived burdensomeness. Additionally, the link between anger and acquired capability was fully mediated by experience with painful and provocative events. In conclusion, results suggest that anger is uniquely associated with perceived burdensomeness and thwarted belongingness. Anger is associated with suicidal ideation and behavior via perceived burdensomeness and with greater acquired capability for suicide via experiences with painful and provocative events. Treatment for problematic anger may be beneficial to decrease risk for suicide. Copyright © 2013 Elsevier Ltd. All rights reserved.

Parental Mediation of Children's Videogame Playing: A Comparison of the Reports by Parents and Children

ERIC Educational Resources Information Center

Nikken, Peter; Jansz, Jeroen

2006-01-01

Through an Internet survey of 536 parent-child dyads, the authors researched which mediation strategies parents used to regulate videogaming by their children (8-18 years). Factor analyses revealed that both parents and children distinguished three types of parental mediation: (1) "restrictive mediation", (2) "active mediation", and (3)…

Bias in Cross-Sectional Analyses of Longitudinal Mediation: Partial and Complete Mediation under an Autoregressive Model

ERIC Educational Resources Information Center

Maxwell, Scott E.; Cole, David A.; Mitchell, Melissa A.

2011-01-01

Maxwell and Cole (2007) showed that cross-sectional approaches to mediation typically generate substantially biased estimates of longitudinal parameters in the special case of complete mediation. However, their results did not apply to the more typical case of partial mediation. We extend their previous work by showing that substantial bias can…

A novel model for studies of blood-mediated long-term responses to cellular transplants

PubMed Central

Lindblom, Susanne; Hong, Jaan; Nilsson, Bo; Korsgren, Olle; Ronquist, Gunnar

2015-01-01

Aims Interaction between blood and bio-surfaces is important in many medical fields. With the aim of studying blood-mediated reactions to cellular transplants, we developed a whole-blood model for incubation of small volumes for up to 48 h. Methods Heparinized polyvinyl chloride tubing was cut in suitable lengths and sealed to create small bags. Multiple bags, with fresh venous blood, were incubated attached to a rotating wheel at 37°C. Physiological variables in blood were monitored: glucose, blood gases, mono- and divalent cations and chloride ions, osmolality, coagulation (platelet consumption, thrombin-antithrombin complexes (TAT)), and complement activation (C3a and SC5b-9), haemolysis, and leukocyte viability. Results Basic glucose consumption was high. Glucose depletion resulted in successive elevation of extracellular potassium, while sodium and calcium ions decreased due to inhibition of energy-requiring ion pumps. Addition of glucose improved ion balance but led to metabolic acidosis. To maintain a balanced physiological environment beyond 6 h, glucose and sodium hydrogen carbonate were added regularly based on analyses of glucose, pH, ions, and osmotic pressure. With these additives haemolysis was prevented for up to 72 h and leukocyte viability better preserved. Despite using non-heparinized blood, coagulation and complement activation were lower during long-term incubations compared with addition of thromboplastin and collagen. Conclusion A novel whole-blood model for studies of blood-mediated responses to a cellular transplant is presented allowing extended observations for up to 48 h and highlights the importance of stringent evaluations and adjustment of physiological conditions. PMID:25322825

Phosphoproteomics analyses show subnetwork systems in T-cell receptor signaling.

PubMed

Hatano, Atsushi; Matsumoto, Masaki; Nakayama, Keiichi I

2016-10-01

A key issue in the study of signal transduction is how multiple signaling pathways are systematically integrated into the cell. We have now performed multiple phosphoproteomics analyses focused on the dynamics of the T-cell receptor (TCR) signaling network and its subsystem mediated by the Ca 2+ signaling pathway. Integration of these phosphoproteomics data sets and extraction of components of the TCR signaling network dependent on Ca 2+ signaling showed unexpected phosphorylation kinetics for candidate substrates of the Ca 2+ -dependent phosphatase calcineurin (CN) during TCR stimulation. Detailed characterization of the TCR-induced phosphorylation of a novel CN substrate, Itpkb, showed that phosphorylation of this protein is regulated by both CN and the mitogen-activated protein kinase Erk in a competitive manner. Phosphorylation of additional CN substrates was also found to be regulated by Erk and CN in a similar manner. The combination of multiple phosphoproteomics approaches thus showed two major subsystems mediated by Erk and CN in the TCR signaling network, with these subsystems regulating the phosphorylation of a group of proteins in a competitive manner. © 2016 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Parasitic nematodes modulate PIN-mediated auxin transport to facilitate infection.

PubMed

Grunewald, Wim; Cannoot, Bernard; Friml, Jirí; Gheysen, Godelieve

2009-01-01

Plant-parasitic nematodes are destructive plant pathogens that cause significant yield losses. They induce highly specialized feeding sites (NFS) in infected plant roots from which they withdraw nutrients. In order to establish these NFS, it is thought that the nematodes manipulate the molecular and physiological pathways of their hosts. Evidence is accumulating that the plant signalling molecule auxin is involved in the initiation and development of the feeding sites of sedentary plant-parasitic nematodes. Intercellular transport of auxin is essential for various aspects of plant growth and development. Here, we analysed the spatial and temporal expression of PIN auxin transporters during the early events of NFS establishment using promoter-GUS/GFP fusion lines. Additionally, single and double pin mutants were used in infection studies to analyse the role of the different PIN proteins during cyst nematode infection. Based on our results, we postulate a model in which PIN1-mediated auxin transport is needed to deliver auxin to the initial syncytial cell, whereas PIN3 and PIN4 distribute the accumulated auxin laterally and are involved in the radial expansion of the NFS. Our data demonstrate that cyst nematodes are able to hijack the auxin distribution network in order to facilitate the infection process.

Fulfillment of administrative and professional obligations of hospitals and mission motivation of physicians.

PubMed

Trybou, Jeroen; Gemmel, Paul; Desmidt, Sebastian; Annemans, Lieven

2017-01-13

To be successful, hospitals must increasingly collaborate with their medical staff. One strategic tool that plays an important role is the mission statement of hospitals. The goal of this research was to study the relationship between the fulfillment of administrative and professional obligations of hospitals on physicians' motivation to contribute to the mission of the hospital. Furthermore the mediating role of the physicians' emotional attachment to the hospital and moderation effect of the exchange with the head physicians were considered. Self-employed physicians of six hospitals participated in a survey. Descriptive analyses and linear regression were used to analyse the data. The results indicate that affective commitment mediated the relationship between psychological contract fulfillment and mission statement motivation. In addition, the quality of exchange with the Chief Medical Officer moderated the relationship between the fulfillment of administrative obligations and affective commitment positively. This study extends our understanding of social exchange processes and mission statement motivation of physicians. We showed that when physicians perceive a high level of fulfillment of their psychological contract they are more committed and more motivated to contribute to the mission statement. A high quality relationship between physician and Chief Medical Officer can enhance this reciprocity dynamic.

Optimism, well-being, depressive symptoms, and perceived physical health: a study among Stroke survivors.

PubMed

Shifren, Kim; Anzaldi, Kristen

2018-01-01

The investigation of the relation of positive personality characteristics to mental and physical health among Stroke survivors has been a neglected area of research. The purpose of this study was to examine the relationship between optimism, well-being, depressive symptoms, and perceived physical health among Stroke survivors. It was hypothesized that Stroke survivors' optimism would explain variance in their physical health above and beyond the variance explained by demographic variables, diagnostic variables, and mental health. One hundred seventy-six Stroke survivors (97 females, 79 males) completed the Revised Life Orientation Test, the Center for Epidemiological Studies Depression Scale, two items on perceived physical health from the 36-item Short Form of the Medical Outcomes study, and the Identity scale of the Illness Perception Questionnaire. Pearson correlations, hierarchical regression analyses, and the PROCESS approach to determining mediators were used to assess hypothesized relations between variables. Stroke survivors' level of optimism explained additional variance in overall health in regression models controlling for demographic and diagnostic variables, and mental health. Analyses revealed that optimism played a partial mediator role between mental health (well-being, depressive symptoms and total score on CES-D) variables and overall health.

Low-molecular-weight heparin for prevention of placenta-mediated pregnancy complications: protocol for a systematic review and individual patient data meta-analysis (AFFIRM)

PubMed Central

2014-01-01

Background Placenta-mediated pregnancy complications include pre-eclampsia, late pregnancy loss, placental abruption, and the small-for-gestational age newborn. They are leading causes of maternal, fetal, and neonatal morbidity and mortality in developed nations. Women who have experienced these complications are at an elevated risk of recurrence in subsequent pregnancies. However, despite decades of research no effective strategies to prevent recurrence have been identified, until recently. We completed a pooled summary-based meta-analysis that strongly suggests that low-molecular-weight heparin reduces the risk of recurrent placenta-mediated complications. The proposed individual patient data meta-analysis builds on this successful collaboration. The project is called AFFIRM, An individual patient data meta-analysis oF low-molecular-weight heparin For prevention of placenta-medIated pRegnancy coMplications. Methods/Design We conducted a systematic review to identify randomized controlled trials with a low-molecular-weight heparin intervention for the prevention of recurrent placenta-mediated pregnancy complications. Investigators and statisticians representing eight trials met to discuss the outcomes and analysis plan for an individual patient data meta-analysis. An additional trial has since been added for a total of nine eligible trials. The primary analyses from the original trials will be replicated for quality assurance prior to recoding the data from each trial and combining it into a common dataset for analysis. Using the anonymized combined data we will conduct logistic regression and subgroup analyses aimed at identifying which women with previous pregnancy complications benefit most from treatment with low-molecular-weight heparin during pregnancy. Discussion The goal of the proposed individual patient data meta-analysis is a thorough estimation of treatment effects in patients with prior individual placenta-mediated pregnancy complications and exploration of which complications are specifically prevented by low-molecular-weight heparin. Systematic review registration PROSPERO (International Prospective Registry of Systematic Reviews) 23 December 2013, CRD42013006249 PMID:24969227

Reducing self-objectification: are dissonance-based methods a possible approach?

PubMed

Becker, Carolyn Black; Hill, Kaitlin; Greif, Rebecca; Han, Hongmei; Stewart, Tiffany

2013-01-01

Previous research has documented that self-objectification is associated with numerous negative outcomes including body shame, eating disorder (ED) pathology, and negative affect. This exploratory open study investigated whether or not an evidence-based body image improvement program that targets thin-ideal internalization in university women also reduces self-objectification. A second aim of the study was to determine if previous findings showing that body shame mediated the relationship between self-objectification and eating disorder pathology at a single time point (consistent with self-objectification theory) but did not mediate longitudinally (inconsistent with self-objectification theory) would be replicated in a new sample under novel conditions. Ninety-six university women completed a peer-led dissonance-based intervention, along with assessment measures at pre-, post-intervention, 8-week and 8-month follow-up. To address the open trial nature of this study, a planned manipulation check was included to make sure that peer-led dissonance decreased thin-ideal internalization, body dissatisfaction, eating disorder pathology, and negative affect with effect sizes being similar to past randomized controlled trials. We hypothesized that all three subscales of the Objectified Body Consciousness Scale (i.e., self-surveillance, body shame, and appearance control beliefs) would be reduced. In addition, we hypothesized that body shame would mediate the relationship between self-objectification (i.e., self-surveillance) and eating disorder pathology at a both at a single time point and longitudinally. The planned manipulation check supported the interpretation that peer-led dissonance in this study largely yielded comparable changes to past controlled trials. In terms of changes in dependent variables, results supported all hypotheses with the exception of body shame, which remained unchanged. With regards to the mediation analyses, our first (cross-sectional) hypothesis but not our second (longitudinal) was supported. Findings provide preliminary support for the use of dissonance interventions in reducing self-surveillance and body control beliefs. Results for body shame and the mediation analyses suggest that greater scrutiny of the body shame construct is warranted.

Oncologist burnout and compassion fatigue: investigating time pressure at work as a predictor and the mediating role of work-family conflict.

PubMed

Kleiner, Sibyl; Wallace, Jean E

2017-09-11

Oncologists are at high risk of poor mental health. Prior research has focused on burnout, and has identified heavy workload as a key predictor. Compassion fatigue among physicians has generally received less attention, although medical specialties such as oncology may be especially at risk of compassion fatigue. We contribute to research by identifying predictors of both burnout and compassion fatigue among oncologists. In doing so, we distinguish between quantitative workload (e.g., work hours) and subjective work pressure, and test whether work-family conflict mediates the relationships between work pressure and burnout or compassion fatigue. In a cross-sectional study, oncologists from across Canada (n = 312) completed questionnaires assessing burnout, compassion fatigue, workload, time pressure at work, work-family conflict, and other personal, family, and occupational characteristics. Analyses use Ordinary Least Squares regression. Subjective time pressure at work is a key predictor of both burnout and compassion fatigue. Our results also show that work-family conflict fully mediates these relationships. Overall, the models explain more of the variation in burnout as compared to compassion fatigue. Our study highlights the need to consider oncologists' subjective time pressure, in addition to quantitative workload, in interventions to improve mental health. The findings also highlight a need to better understand additional predictors of compassion fatigue.

Transforming growth factor beta induced FoxP3+ regulatory T cells suppress Th1 mediated experimental colitis.

PubMed

Fantini, M C; Becker, C; Tubbe, I; Nikolaev, A; Lehr, H A; Galle, P; Neurath, M F

2006-05-01

The imbalance between effector and regulatory T cells plays a central role in the pathogenesis of inflammatory bowel diseases. In addition to the thymus, CD4+CD25+ regulatory T cells can be induced in the periphery from a population of CD25- T cells by treatment with transforming growth factor beta (TGF-beta). Here, we analysed the in vivo function of TGF-beta induced regulatory T (Ti-Treg) cells in experimental colitis. Ti-Treg cells were generated in cell culture in the presence or absence of TGF-beta and tested for their regulatory potential in experimental colitis using the CD4+CD62L+ T cell transfer model. Ti-Treg cells significantly suppressed Th1 mediated colitis on CD4+CD62L+ T cell transfer in vivo, as shown by high resolution endoscopy, histology, immunohistochemistry, and cytokine analysis. Further analysis of in vivo and in vitro expanded Ti-Treg cells showed that exogenous interleukin 2 (IL-2) was crucial for survival and expansion of these cells. Our data suggest that regulatory Ti-Treg cells expand by TGF-beta and exogenous IL-2 derived from effector T cells at the site of inflammation. In addition to Tr1 and thymic CD4+CD25+ T cells, peripheral Ti-Treg cells emerge as a class of regulatory T cells with therapeutic potential in T cell mediated chronic intestinal inflammation.

The ties that bind: perceived social support, stress, and IBS in severely affected patients.

PubMed

Lackner, J M; Brasel, A M; Quigley, B M; Keefer, L; Krasner, S S; Powell, C; Katz, L A; Sitrin, M D

2010-08-01

This study assessed the association between social support and the severity of irritable bowel syndrome (IBS) symptoms in a sample of severely affected IBS patients recruited to an NIH-funded clinical trial. In addition, we examined if the effects of social support on IBS pain are mediated through the effects on stress. Subjects were 105 Rome II diagnosed IBS patients (F = 85%) who completed seven questionnaires which were collected as part of a pretreatment baseline assessment. Partial correlations were conducted to clarify the relationships between social support and clinically relevant variables with baseline levels of psychopathology, holding constant number of comorbid medical diseases, age, gender, marital status, ethnicity, and education. Analyses indicated that social support was inversely related to IBS symptom severity. Social support was positively related with less severe pain. A similar pattern of data was found for perceived stress but not quality of life impairment. Regression analyses examined if the effects of social support on pain are mediated by stress. The effects of social support on bodily pain were mediated by stress such that the greater the social support the less stress and the less pain. This effect did not hold for symptom severity, quality of life, or psychological distress. This study links the perceived adequacy of social support to the global severity of symptoms of IBS and its cardinal symptom (pain). It also suggests that the mechanism by which social support alleviates pain is through a reduction in stress levels.

Canthaxanthin production with modified Mucor circinelloides strains.

PubMed

Papp, Tamás; Csernetics, Arpád; Nagy, Gábor; Bencsik, Ottó; Iturriaga, Enrique A; Eslava, Arturo P; Vágvölgyi, Csaba

2013-06-01

Canthaxanthin is a natural diketo derivative of β-carotene primarily used by the food and feed industries. Mucor circinelloides is a β-carotene-accumulating zygomycete fungus and one of the model organisms to study the carotenoid biosynthesis in fungi. In this study, the β-carotene ketolase gene (crtW) of the marine bacterium Paracoccus sp. N81106 fused with fungal promoter and terminator regions was integrated into the M. circinelloides genome to construct stable canthaxanthin-producing strains. Different transformation methods including polyethylene glycol-mediated transformation with linear DNA fragments, restriction enzyme-mediated integration and Agrobacterium tumefaciens-mediated transformation were tested to integrate the crtW gene into the Mucor genome. Mitotic stability, site of integration and copy number of the transferred genes were analysed in the transformants, and several stable strains containing the crtW gene in high copy number were isolated. Carotenoid composition of selected transformants and effect of culturing conditions, such as temperature, carbon sources and application of certain additives in the culturing media, on their carotenoid content were analysed. Canthaxanthin-producing transformants were able to survive at higher growth temperature than the untransformed strain, maybe due to the effect of canthaxanthin on the membrane fluidity and integrity. With the application of glucose, trehalose, dihydroxyacetone and L-aspartic acid as sole carbon sources in minimal medium, the crtW-expressing M. circinelloides strain, MS12+pCA8lf/1, produced more than 200 μg/g (dry mass) of canthaxanthin.

Work climate and the mediating role of workplace bullying related to job performance, job satisfaction, and work ability: A study among hospital nurses.

PubMed

Olsen, Espen; Bjaalid, Gunhild; Mikkelsen, Aslaug

2017-11-01

To increase understanding of workplace bullying and its relation to work climate and different outcomes among nurses. Examine a proposed bullying model including both job resource and job demands, as well as nurse outcomes reflected in job performance, job satisfaction, and work ability. Workplace bullying has been identified as some of the most damaging mechanisms in workplace settings. It is important to increase understanding of workplace bullying in relation to work climate and different outcomes among nurses. This study adopted a cross-sectional web based survey design. A sample of 2946 Registered Nurses from four public Norwegian hospitals were collected during October 2014. We analysed data using descriptive statistics, correlations, Cronbach's alpa, confirmatory factor analyses, and structural equation modelling. The majority of work climate characteristics confirmed to influence workplace bullying, and additionally had direct influence on nurse outcomes; job performance, job satisfaction, and work ability. Bullying had a mediational role between most of the work climate dimensions and nurse outcomes. This study increases our understanding of organizational antecedent of bullying among nurses. Workplace bullying among nurses functions as a mediator between the majority of work climate dimensions and outcomes related to job satisfaction and work ability. Strategies to reduce bullying should look at the study finding and specifically job resources and job demands that influence bullying and nurse outcomes. © 2017 John Wiley & Sons Ltd.

The Merits of Using Longitudinal Mediation

ERIC Educational Resources Information Center

Jose, Paul E.

2016-01-01

Many of the mediation analyses reported in the literature are based on concurrent or single-occasion data sets. The 2 overarching themes of the present article are: Results of concurrent mediations are inherently ambiguous, and researchers would be wise to conduct mediations on longitudinal data sets instead. An example included here demonstrates…

Single-Level and Multilevel Mediation Analysis

ERIC Educational Resources Information Center

Tofighi, Davood; Thoemmes, Felix

2014-01-01

Mediation analysis is a statistical approach used to examine how the effect of an independent variable on an outcome is transmitted through an intervening variable (mediator). In this article, we provide a gentle introduction to single-level and multilevel mediation analyses. Using single-level data, we demonstrate an application of structural…

Acculturation, Social Self-Control, and Substance Use Among Hispanic Adolescents

PubMed Central

Pokhrel, Pallav; Herzog, Thaddeus A.; Sun, Ping; Rohrbach, Louise A.; Sussman, Steve

2014-01-01

It is unclear how acculturation is related to self-control characteristics and whether part of the effect of acculturation on Hispanic adolescents’ substance use behavior is mediated through lower self-control. We tested social self-control, peer substance use, and baseline substance use as mediators of the effect of Hispanic (predominantly Mexican or Mexican American) adolescents’ level of U.S. acculturation on their substance use behavior 1 year later. In addition, we tested gender as a possible moderator of the pathways involved in the mediation model. Participants included 1,040 self-identified Hispanic/Latino adolescents (M = 14.7; SD = 0.90; 89% Mexican/Mexican American) recruited from nine public high schools. Acculturation was measured in terms of adolescents’ extent of English language use in general, at home, with friends, and their use of the English-language entertainment media. Analyses were conducted using structural equation modeling and controlled for potential confounders such as age and parental education. Results indicated a statistically significant three-path mediation in which poor social self-control and peer substance use mediated the effects of acculturation on prospective substance use. Paths in the mediation model were not found to differ by gender. Our findings suggest that acculturation may influence adolescents’ self-control characteristics related to interpersonal functioning, which may in turn influence their affiliation with substance-using friends and substance use behavior. Implications of the findings are discussed in terms of future research and prevention programming. PMID:23772765

[Childhood Traumas and Attachment Style-Associated Depression Symptoms: The Mediator Role of Alexithymia].

PubMed

Şenkal, İpek; Işıklı, Sedat

2015-01-01

The aim of this study was to investigate the mediator role of alexithymia and its relationship with childhood traumas (sexual abuse, physical abuse, emotional abuse, emotional neglect, physical neglect) and attachment style (anxiety and avoidance dimensions of attachment) associated depression symptoms in adulthood. The sample of this study included 417 undergraduate university students from different departments that studied at Hacettepe University during the 2012-2013 school years with a final analysis done over 369 participants. The Demographic Information Form, Experiences in Close Relationship Inventory-II (ECR-R), Childhood Trauma Questionnaire (CTQ), Toronto Alexithymia Scale (TAS-20), and Beck Depression Inventory (BDI) were administered to the undergraduate students who participated in this study. Mediator analyses were applied to the data. The results revealed that the total score of the Toronto Alexithymia Scale had a partial mediating role in the relationship of childhood traumas (the total score of Childhood Trauma Questionnaire), childhood emotional abuse and emotional neglect with depressive symptom levels in university students. Besides, the total score of the Toronto Alexithymia Scale had a full mediating role in the relationship between childhood physical neglect and depressive symptom levels in adulthood. Additionally, it was found that the total score of the Toronto Alexithymia Scale had a partial mediating role between the anxiety dimension of the attachment and the depressive symptom levels. This study revealed that alexithymia should be considered as a significant variable in the relationship of childhood traumas and attachment patterns with depression symptoms in adulthood.

Mutation Detection with Next-Generation Resequencing through a Mediator Genome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wurtzel, Omri; Dori-Bachash, Mally; Pietrokovski, Shmuel

2010-12-31

The affordability of next generation sequencing (NGS) is transforming the field of mutation analysis in bacteria. The genetic basis for phenotype alteration can be identified directly by sequencing the entire genome of the mutant and comparing it to the wild-type (WT) genome, thus identifying acquired mutations. A major limitation for this approach is the need for an a-priori sequenced reference genome for the WT organism, as the short reads of most current NGS approaches usually prohibit de-novo genome assembly. To overcome this limitation we propose a general framework that utilizes the genome of relative organisms as mediators for comparing WTmore » and mutant bacteria. Under this framework, both mutant and WT genomes are sequenced with NGS, and the short sequencing reads are mapped to the mediator genome. Variations between the mutant and the mediator that recur in the WT are ignored, thus pinpointing the differences between the mutant and the WT. To validate this approach we sequenced the genome of Bdellovibrio bacteriovorus 109J, an obligatory bacterial predator, and its prey-independent mutant, and compared both to the mediator species Bdellovibrio bacteriovorus HD100. Although the mutant and the mediator sequences differed in more than 28,000 nucleotide positions, our approach enabled pinpointing the single causative mutation. Experimental validation in 53 additional mutants further established the implicated gene. Our approach extends the applicability of NGS-based mutant analyses beyond the domain of available reference genomes.« less

Light driven mesoscale assembly of a coordination polymeric gelator into flowers and stars with distinct properties† †Electronic supplementary information (ESI) available: Text, figures, and tables depicting different synthetic procedures, detailed experimental procedures, characterisation data including FT-IR, microscopic analyses, TGA, EDAX and SAED analyses, pore size distribution. See DOI: 10.1039/c5sc02233a Click here for additional data file.

PubMed Central

Mukhopadhyay, Rahul Dev; Praveen, Vakayil K.; Hazra, Arpan; Maji, Tapas Kumar

2015-01-01

Control over the self-assembly process of porous organic–inorganic hybrids often leads to unprecedented polymorphism and properties. Herein we demonstrate how light can be a powerful tool to intervene in the kinetically controlled mesoscale self-assembly of a coordination polymeric gelator. Ultraviolet light induced coordination modulation via photoisomerisation of an azobenzene based dicarboxylate linker followed by aggregation mediated crystal growth resulted in two distinct morphological forms (flowers and stars), which show subtle differences in their physical properties. PMID:28757961

How job demands affect absenteeism? The mediating role of work-family conflict and exhaustion.

PubMed

Vignoli, Michela; Guglielmi, Dina; Bonfiglioli, Roberta; Violante, Francesco Saverio

2016-01-01

To investigate how psychosocial factors (such as job demands and work-family conflict) produce absenteeism in the workplace, using the health impairment process of the job demands-resources model. According to this model, job demands lead to burnout (often measured with the emotional exhaustion component), which in turn could lead to outcomes (such as absenteeism). Work-family conflict (WFC) was also studied, because of contradictory results collected in the existing literature on absenteeism in the workplace, regarding the role of WFC in causing absenteeism. Data were collected on 245 workers using both subjective (questionnaire on psychological risk factors and work-related health) and objective data (sickness leave frequency records). To test the hypothesis that job demands and WFC contribute to absenteeism in the workplace, a subsequent mediation analysis was used, which analysed both (a) the subsequent mediation of WFC and emotional exhaustion and (b) the separate roles played by the mediators proposed (WFC and emotional exhaustion). Job demands affect absenteeism through the subsequent mediation of WFC and emotional exhaustion. In addition, emotional exhaustion mediates the relationship between job demands and absenteeism, while WFC does not. In conclusion, subsequent mediation highlights the role of emotional exhaustion in causing absenteeism; in fact, when emotional exhaustion is included in the analysis, job demands are associated with higher levels of absenteeism. The results of this study suggest that without the concurrent contribution of emotional exhaustion, WFC does not influence absenteeism in the workplace. Our findings are useful for organizations that aim to reduce absenteeism.

Keep Up the Good Work! Age-Moderated Mediation Model on Intention to Retire

PubMed Central

Dordoni, Paola; Van der Heijden, Beatrice; Peters, Pascale; Kraus-Hoogeveen, Sascha; Argentero, Piergiorgio

2017-01-01

In European nations, the aging of the workforce is a major issue which is increasingly addressed both in national and organizational policies in order to sustain older workers' employability and to encourage longer working lives. Particularly older workers' employability can be viewed an important issue as this has the potential to motivate them for their work and change their intention to retire. Based on lifespan development theories and Van der Heijden's ‘employability enhancement model’, this paper develops and tests an age-moderated mediation model (which refers to the processes that we want to test in this model), linking older workers' (55 years old and over) perceptions of job support for learning (job-related factor) and perceptions of negative age stereotypes on productivity (organizational factor), on the one hand, and their intention to retire, on the other hand, via their participation in employability enhancing activities, being the mediator in our model. A total of 2,082 workers aged 55 years and above were included in the analyses. Results revealed that the two proposed relationships between the predictors and intention to retire were mediated by participation in employability enhancing activities, reflecting two mechanisms through which work context affects intention to retire (namely ‘a gain spiral and a loss spiral’). Multi-Group SEM analyses, distinguishing between two age groups (55–60 and 61–65 years old), revealed different paths for the two distinguished groups of older workers. Employability mediated the relationship between perceptions of job support for learning and intention to retire in both age groups, whereas it only mediated the relationship between perceptions of negative age stereotypes and intention to retire in the 55–60 group. From our empirical study, we may conclude that employability is an important factor in the light of older workers' intention to retire. In order to motivate this category of workers to participate in employability enhancing activities and to work longer, negative age stereotypes need to be combated. In addition, creating job support for learning over the lifespan is also an important HR practice to be implemented in nowadays' working life. PMID:29089905

Keep Up the Good Work! Age-Moderated Mediation Model on Intention to Retire.

PubMed

Dordoni, Paola; Van der Heijden, Beatrice; Peters, Pascale; Kraus-Hoogeveen, Sascha; Argentero, Piergiorgio

2017-01-01

In European nations, the aging of the workforce is a major issue which is increasingly addressed both in national and organizational policies in order to sustain older workers' employability and to encourage longer working lives. Particularly older workers' employability can be viewed an important issue as this has the potential to motivate them for their work and change their intention to retire. Based on lifespan development theories and Van der Heijden's 'employability enhancement model', this paper develops and tests an age-moderated mediation model (which refers to the processes that we want to test in this model), linking older workers' (55 years old and over) perceptions of job support for learning (job-related factor) and perceptions of negative age stereotypes on productivity (organizational factor), on the one hand, and their intention to retire, on the other hand, via their participation in employability enhancing activities, being the mediator in our model. A total of 2,082 workers aged 55 years and above were included in the analyses. Results revealed that the two proposed relationships between the predictors and intention to retire were mediated by participation in employability enhancing activities, reflecting two mechanisms through which work context affects intention to retire (namely 'a gain spiral and a loss spiral'). Multi-Group SEM analyses, distinguishing between two age groups (55-60 and 61-65 years old), revealed different paths for the two distinguished groups of older workers. Employability mediated the relationship between perceptions of job support for learning and intention to retire in both age groups, whereas it only mediated the relationship between perceptions of negative age stereotypes and intention to retire in the 55-60 group. From our empirical study, we may conclude that employability is an important factor in the light of older workers' intention to retire. In order to motivate this category of workers to participate in employability enhancing activities and to work longer, negative age stereotypes need to be combated. In addition, creating job support for learning over the lifespan is also an important HR practice to be implemented in nowadays' working life.

Maternal socialization goals, parenting styles, and social-emotional adjustment among Chinese and European American young adults: testing a mediation model.

PubMed

Li, Yan; Costanzo, Philip R; Putallaz, Martha

2010-01-01

The authors compared the associations among perceived maternal socialization goals (self-development, filial piety, and collectivism), perceived maternal parenting styles (authoritative, authoritarian, and training), and the social-emotional adjustment (self-esteem, academic self-efficacy, and depression) between Chinese and European American young adults. The mediation processes in which socialization goals relate to young adults' adjustment outcomes through parenting styles were examined. Results showed that European American participants perceived higher maternal self-development socialization goals, whereas Chinese participants perceived higher maternal collectivism socialization goals as well as more authoritarian parenting. Cross-cultural similarities were found in the associations between perceived maternal authoritative parenting and socioemotional adjustment (e.g., higher self-esteem and higher academic self-efficacy) across the two cultural groups. However, perceived maternal authoritarian and training parenting styles were found only to be related to Chinese participants' adjustment (e.g., higher academic self-efficacy and lower depression). The mediation analyses showed that authoritative parenting significantly mediated the positive associations between the self-development and collectivism goal and socioemotional adjustment for both cultural groups. Additionally, training parenting significantly mediated the positive association between the filial piety goal and young adults' academic self-efficacy for the Chinese group only. Findings of this study highlight the importance of examining parental socialization goals in cross-cultural parenting research.

[Interrelations Between Adolescent Problematic Internet Use and Parental Internet Mediation].

PubMed

Kammerl, Rudolf; Wartberg, Lutz

2018-02-01

Interrelations Between Adolescent Problematic Internet Use and Parental Internet Mediation Everyday life of adolescents and their parents is increasingly characterized by digital media usage (also referred to as "process of mediatization"). In the current study, associations between problematic Internet use of the adolescents (as a possible consequence of the process of mediatization) and parental media education were explored. For this purpose, throughout Germany 1,095 family dyads (an adolescent and a related parent) were investigated with a standardized questionnaire measuring different aspects of parental media education and adolescent problematic Internet use. We conducted two multiple linear regression analyses (dimensional approach) with adolescent problematic Internet use based on self-ratings (model 1, corrected R 2 = 0.18) and parental assessment (model 2, corrected R 2 = 0.24) as response variables. Consistently for self- and parental ratings, adolescent problematic Internet use was statistically significant related to male gender (of the adolescent), a more frequent inconsistent media education (adolescents' and parents' perspective) and a stronger monitoring (parents' perspective). Additionally, we observed associations between the parental rating of adolescent problematic Internet use and a less frequent active and restrictive Internet Mediation (parents' perspective). The findings of the present study show the importance of parental media education for problematic Internet use in adolescence and especially, the role of inconsistent media education should be investigated again in further studies.

Differential contributions of executive and episodic memory functions to problem solving in younger and older adults.

PubMed

Vandermorris, Susan; Sheldon, Signy; Winocur, Gordon; Moscovitch, Morris

2013-11-01

The relationship of higher order problem solving to basic neuropsychological processes likely depends on the type of problems to be solved. Well-defined problems (e.g., completing a series of errands) may rely primarily on executive functions. Conversely, ill-defined problems (e.g., navigating socially awkward situations) may, in addition, rely on medial temporal lobe (MTL) mediated episodic memory processes. Healthy young (N = 18; M = 19; SD = 1.3) and old (N = 18; M = 73; SD = 5.0) adults completed a battery of neuropsychological tests of executive and episodic memory function, and experimental tests of problem solving. Correlation analyses and age group comparisons demonstrated differential contributions of executive and autobiographical episodic memory function to well-defined and ill-defined problem solving and evidence for an episodic simulation mechanism underlying ill-defined problem solving efficacy. Findings are consistent with the emerging idea that MTL-mediated episodic simulation processes support the effective solution of ill-defined problems, over and above the contribution of frontally mediated executive functions. Implications for the development of intervention strategies that target preservation of functional independence in older adults are discussed.

Reaping the benefits of meaningful work: The mediating versus moderating role of work engagement.

PubMed

Johnson, Matthew J; Jiang, Lixin

2017-08-01

This study examined whether meaningful work may improve one's quality of life outside of the workplace (i.e., work-to-life enrichment). More importantly, we proposed and tested competing hypotheses regarding the role of work engagement in the relationship between meaningful work and work-to-life enrichment. Specifically, we investigated whether work engagement served as a mediator of this relationship, as suggested by the job demands-resources model, or instead a moderator, as suggested by conservation of resources theory. Two-wave survey data were collected from 194 respondents recruited via Amazon Mechanical Turk. Analyses showed that meaningful work was positively related to work-to-life enrichment over time (i.e., 3 months later). Additionally, work engagement mediated but did not moderate the relationship between meaningful work at Time 1 and work-to-life enrichment at Time 2. We suggest that organizations foster a sense of meaningfulness in employees to facilitate engagement and in turn enrich employees' lives beyond the workplace. Therefore, not only organizations, but individuals as well may reap the benefits of meaningful work. Copyright © 2016 John Wiley & Sons, Ltd.

Planning Abilities in Bilingual and Monolingual Children: Role of Verbal Mediation.

PubMed

Gangopadhyay, Ishanti; McDonald, Margarethe; Ellis Weismer, Susan; Kaushanskaya, Margarita

2018-01-01

We examined the role of verbal mediation in planning performance of English-Spanish-speaking bilingual children and monolingual English-speaking children, between the ages of 9 and 12 years. To measure planning, children were administered the Tower of London (ToL) task. In a dual-task paradigm, children completed ToL problems under three conditions: with no secondary task (baseline), with articulatory suppression, and with non-verbal motor suppression. Analyses revealed generally shorter planning times for bilinguals than monolinguals but both groups performed similarly on number of moves and execution times. Additionally, bilingual children were more efficient at planning throughout the duration of the task while monolingual children showed significant gains with more practice. Children's planning times under articulatory suppression were significantly shorter than under motor suppression as well as the baseline condition, and there was no difference in planning times between monolingual and bilingual children during articulatory suppression. These results demonstrate that bilingualism influences performance on a complex EF measure like planning, and that these effects are not related to verbal mediation.

Planning Abilities in Bilingual and Monolingual Children: Role of Verbal Mediation

PubMed Central

Gangopadhyay, Ishanti; McDonald, Margarethe; Ellis Weismer, Susan; Kaushanskaya, Margarita

2018-01-01

We examined the role of verbal mediation in planning performance of English–Spanish-speaking bilingual children and monolingual English-speaking children, between the ages of 9 and 12 years. To measure planning, children were administered the Tower of London (ToL) task. In a dual-task paradigm, children completed ToL problems under three conditions: with no secondary task (baseline), with articulatory suppression, and with non-verbal motor suppression. Analyses revealed generally shorter planning times for bilinguals than monolinguals but both groups performed similarly on number of moves and execution times. Additionally, bilingual children were more efficient at planning throughout the duration of the task while monolingual children showed significant gains with more practice. Children’s planning times under articulatory suppression were significantly shorter than under motor suppression as well as the baseline condition, and there was no difference in planning times between monolingual and bilingual children during articulatory suppression. These results demonstrate that bilingualism influences performance on a complex EF measure like planning, and that these effects are not related to verbal mediation. PMID:29593620

The role of proteosome-mediated proteolysis in modulating potentially harmful transcription factor activity in Saccharomyces cerevisiae

PubMed Central

Bonzanni, Nicola; Zhang, Nianshu; Oliver, Stephen G.; Fisher, Jasmin

2011-01-01

Motivation: The appropriate modulation of the stress response to variable environmental conditions is necessary to maintain sustained viability in Saccharomyces cerevisiae. Particularly, controlling the abundance of proteins that may have detrimental effects on cell growth is crucial for rapid recovery from stress-induced quiescence. Results: Prompted by qualitative modeling of the nutrient starvation response in yeast, we investigated in vivo the effect of proteolysis after nutrient starvation showing that, for the Gis1 transcription factor at least, proteasome-mediated control is crucial for a rapid return to growth. Additional bioinformatics analyses show that potentially toxic transcriptional regulators have a significantly lower protein half-life, a higher fraction of unstructured regions and more potential PEST motifs than the non-detrimental ones. Furthermore, inhibiting proteasome activity tends to increase the expression of genes induced during the Environmental Stress Response more than those in the rest of the genome. Our combined results suggest that proteasome-mediated proteolysis of potentially toxic transcription factors tightly modulates the stress response in yeast. Contact: jasmin.fisher@microsoft.com Supplementary information: Supplementary data are available at Bioinformatics online. PMID:21685082

The effects of violent video game habits on adolescent hostility, aggressive behaviors, and school performance.

PubMed

Gentile, Douglas A; Lynch, Paul J; Linder, Jennifer Ruh; Walsh, David A

2004-02-01

Video games have become one of the favorite activities of American children. A growing body of research is linking violent video game play to aggressive cognitions, attitudes, and behaviors. The first goal of this study was to document the video games habits of adolescents and the level of parental monitoring of adolescent video game use. The second goal was to examine associations among violent video game exposure, hostility, arguments with teachers, school grades, and physical fights. In addition, path analyses were conducted to test mediational pathways from video game habits to outcomes. Six hundred and seven 8th- and 9th-grade students from four schools participated. Adolescents who expose themselves to greater amounts of video game violence were more hostile, reported getting into arguments with teachers more frequently, were more likely to be involved in physical fights, and performed more poorly in school. Mediational pathways were found such that hostility mediated the relationship between violent video game exposure and outcomes. Results are interpreted within and support the framework of the General Aggression Model.

Mediating effects of self-stigma on the relationship between perceived stigma and psychosocial outcomes among psychiatric outpatients: findings from a cross-sectional survey in Singapore

PubMed Central

Picco, Louisa; Lau, Ying Wen; Pang, Shirlene; Abdin, Edimansyah; Vaingankar, Janhavi Ajit; Chong, Siow Ann; Subramaniam, Mythily

2017-01-01

Objectives To examine whether self-stigma mediates the relationship between perceived stigma and quality of life, self-esteem and general functioning among outpatients with depression, schizophrenia, anxiety and obsessive-compulsive disorder (OCD). Design Cross-sectional survey. Setting Outpatient clinics at a tertiary psychiatric hospital in Singapore. Participants 280 outpatients with a primary clinical diagnosis of either schizophrenia, depression, anxiety or OCD. Methods Data were collected in relation to self-stigma, perceived stigma, self-esteem, functioning and quality of life. In order to examine the mediating role of self-stigma on the relationship between perceived stigma and psychosocial outcomes, bootstrapping mediation analyses were used. Results Mediation analyses revealed that the relationship between perceived stigma and psychosocial outcomes was subject to the effects of self-stigma among the overall sample. Separate mediation analyses were conducted by diagnoses and showed differences in the mediating effects of self-stigma. Among the whole sample and the subsample with OCD, self-stigma mediated the relationship between perceived stigma and all psychosocial outcomes. For those with anxiety, depression and schizophrenia, the mediating effects of self-stigma were present in all relationships except (1) perceived stigma with physical health in the anxiety sample, (2) perceived stigma with social relationships in the depression sample and (3) perceived stigma with physical health in the schizophrenia sample. Conclusions The mediating effects of self-stigma on the relationship between perceived stigma and various psychosocial outcomes are evident and differ across diagnoses. Interventions to address and reduce the effects of self-stigma along with targeted treatments and psychoeducation to assist people with mental illness overcome or better manage self-stigma while providing them the skills to counteract public stigma are needed. PMID:28851803

When mothers have serious mental health problems: parenting as a proximal mediator.

PubMed

Oyserman, Daphna; Bybee, Deborah; Mowbray, Carol; Hart-Johnson, Tamera

2005-08-01

Maternal mental health (MMH) problems are associated with lack of confidence in one's parenting, overly lax or too harsh discipline, and child academic underperformance. We asked if parenting mediates the effect of MMH problems on academic outcomes even among mothers with serious mental illness (n=164). Structural equation analyses show a significant association between MMH problems and permissive (lack of parenting confidence, lack of follow through) parenting and verbal hostility as well as worse academic outcomes (school recorded grades, teacher reported behaviour). Permissive parenting completely mediated the direct effect of MMH on academic outcomes. Further analyses showed that the mediation effect was attributed to a single component of permissive parenting-lack of parenting confidence.

An Examination of Mediators of the Transfer of Cognitive Speed of Processing Training to Everyday Functional Performance

PubMed Central

Edwards, Jerri D.; Ruva, Christine L.; O’Brien, Jennifer L.; Haley, Christine B.; Lister, Jennifer J.

2013-01-01

The purpose of these analyses was to examine mediators of the transfer of cognitive speed of processing training to improved everyday functional performance (Edwards, Wadley, Vance, Roenker, & Ball, 2005). Cognitive speed of processing and visual attention (as measured by the Useful Field of View Test; UFOV) were examined as mediators of training transfer. Secondary data analyses were conducted from the Staying Keen in Later Life (SKILL) study, a randomized cohort study including 126 community dwelling adults 63 to 87 years of age. In the SKILL study, participants were randomized to an active control group or cognitive speed of processing training (SOPT), a non-verbal, computerized intervention involving perceptual practice of visual tasks. Prior analyses found significant effects of training as measured by the UFOV and Timed Instrumental Activities of Daily Living (TIADL) Tests. Results from the present analyses indicate that speed of processing for a divided attention task significantly mediated the effect of SOPT on everyday performance (e.g., TIADL) in a multiple mediation model accounting for 91% of the variance. These findings suggest that everyday functional improvements found from SOPT are directly attributable to improved UFOV performance, speed of processing for divided attention in particular. Targeting divided attention in cognitive interventions may be important to positively affect everyday functioning among older adults. PMID:23066808

Digital Cognitive Behavioural Therapy for Insomnia versus sleep hygiene education: the impact of improved sleep on functional health, quality of life and psychological well-being. Study protocol for a randomised controlled trial.

PubMed

Espie, Colin A; Luik, Annemarie I; Cape, John; Drake, Christopher L; Siriwardena, A Niroshan; Ong, Jason C; Gordon, Christopher; Bostock, Sophie; Hames, Peter; Nisbet, Mhairi; Sheaves, Bryony; G Foster, Russell; Freeman, Daniel; Costa-Font, Joan; Emsley, Richard; Kyle, Simon D

2016-05-23

Previous research has demonstrated that digital CBT (dCBT), delivered via the Internet, is a scalable and effective intervention for treating insomnia in otherwise healthy adults and leads to significant improvements in primary outcomes relating to sleep. The majority of people with insomnia, however, seek help because of the functional impact and daytime consequences of poor sleep, not because of sleep discontinuity per se. Although some secondary analyses suggest that dCBT may have wider health benefits, no adequately powered study has investigated these as a primary endpoint. This study specifically aims to investigate the impact of dCBT for insomnia upon health and well-being, and will investigate sleep-related changes as mediating factors. We propose a pragmatic, parallel-group, randomised controlled trial of 1000 community participants meeting criteria for insomnia disorder. In the DIALS trial (Digital Insomnia therapy to Assist your Life as well as your Sleep), participants will be randomised to dCBT delivered using web and/or mobile channels (in addition to treatment as usual (TAU)) or to sleep hygiene education (SHE), comprising a website plus a downloadable booklet (in addition to TAU). Online assessments will take place at 0 (baseline), 4 (mid-treatment), 8 (post-treatment), and 24 (follow-up) weeks. At week 25 all participants allocated to SHE will be offered dCBT, at which point the controlled element of the trial will be complete. Naturalistic follow-up will be invited at weeks 36 and 48. Primary outcomes are functional health and well-being at 8 weeks. Secondary outcomes are mood, fatigue, sleepiness, cognitive function, productivity and social functioning. All main analyses will be carried out at the end of the final controlled follow-up assessments and will be based on the intention-to-treat principle. Further analyses will determine whether observed changes in functional health and well-being are mediated by changes in sleep. The trial is funded by Big Health Ltd. This study will be the first large-scale, specifically designed investigation of the health and well-being benefits of CBT for insomnia, and the first examination of the association between CBT-mediated sleep improvement and health status. ISRCTN60530898 .

Determinants of lifestyle behavior change to prevent type 2 diabetes in high-risk individuals.

PubMed

den Braver, N R; de Vet, E; Duijzer, G; Ter Beek, J; Jansen, S C; Hiddink, G J; Feskens, E J M; Haveman-Nies, A

2017-06-12

Although there are many effective lifestyle interventions for type 2 diabetes (T2DM) prevention, insight into effective intervention pathways, especially of long-term interventions, is often lacking. This study aims to provide insight into the effective intervention pathways of the SLIMMER diabetes prevention intervention using mediation analyses. In total, 240 participants at increased risk of T2DM were included in the analyses over 18 months. The intervention was a combined lifestyle intervention with a dietary and a physical activity (PA) component. The primary and secondary outcomes were change in fasting insulin (pmol/L) and change in body weight (kg) after 18 months, respectively. Firstly, in a multiple mediator model, we investigated whether significant changes in these outcomes were mediated by changes in dietary and PA behavior. Secondly, in multiple single mediator models, we investigated whether changes in dietary and PA behavior were mediated by changes in behavioral determinants and the participants' psychological profile. The mediation analyses used linear regression models, where significance of indirect effects was calculated with bootstrapping. The effect of the intervention on decreased fasting insulin was 40% mediated by change in dietary and PA behavior, where dietary behavior was an independent mediator of the association (34%). The effect of the intervention on decreased body weight was 20% mediated by change in dietary and PA behavior, where PA behavior was an independent mediator (17%). The intervention significantly changed intake of fruit, fat from bread spread, and fiber from bread. Change in fruit intake was mediated by change in action control (combination of consciousness, self-control, and effort), motivation, self-efficacy, intention, and skills. Change in fat intake was mediated by change in action control and psychological profile. No mediators could be identified for change in fiber intake. The change in PA behavior was mediated by change in action control, motivation, and psychological profile. The effect of the SLIMMER intervention on fasting insulin and body weight was mediated by changes in dietary and PA behavior, in distinct ways. These results indicate that changing dietary as well as PA behavior is important in T2DM prevention.

The relationship between parental overprotection and health-related quality of life in pediatric cancer: the mediating role of perceived child vulnerability.

PubMed

Hullmann, Stephanie E; Wolfe-Christensen, Cortney; Meyer, William H; McNall-Knapp, Rene Y; Mullins, Larry L

2010-11-01

The current study sought to examine the relation of parental overprotection and perceived child vulnerability to parent-reported health-related quality of life in parents of children with cancer. Parents (N = 89) of children who had been diagnosed with cancer completed measures of parental overprotection, perceived child vulnerability, and parent-proxy report of health-related quality of life. After controlling for theoretically relevant covariates, parental overprotection and perceived child vulnerability were both found to be significantly related to child health-related quality of life. Additional analyses revealed that perceived child vulnerability mediated the relationship between overprotective parenting behaviors and the child's health-related quality of life. The findings highlight the need to assess for these discrete parenting variables in parents of children with cancer and to develop interventions to target parental perceptions of vulnerability.

Gratitude and prosocial behavior: helping when it costs you.

PubMed

Bartlett, Monica Y; DeSteno, David

2006-04-01

The ability of the emotion gratitude to shape costly prosocial behavior was examined in three studies employing interpersonal emotion inductions and requests for assistance. Study 1 demonstrated that gratitude increases efforts to assist a benefactor even when such efforts are costly (i.e., hedonically negative), and that this increase differs from the effects of a general positive affective state. Additionally, mediational analyses revealed that gratitude, as opposed to simple awareness of reciprocity norms, drove helping behavior. Furthering the theory that gratitude mediates prosocial behavior, Study 2 replicated the findings of Study 1 and demonstrated gratitude's ability to function as an incidental emotion by showing it can increase assistance provided to strangers. Study 3 revealed that this incidental effect dissipates if one is made aware of the true cause of the emotional state. Implications of these findings for the role of gratitude in building relationships are discussed.

Rapid and Sensitive Detection of Lymphocystis Disease Virus Genotype VII by Loop-Mediated Isothermal Amplification.

PubMed

Valverde, Estefanía J; Cano, Irene; Castro, Dolores; Paley, Richard K; Borrego, Juan J

2017-03-01

Lymphocystis disease virus (LCDV) infections have been described in gilthead seabream (Sparus aurata L.) and Senegalese sole (Solea senegalensis, Kaup), two of the most important marine fish species in the Mediterranean aquaculture. In this study, a rapid, specific, and sensitive detection method for LCDV genotype VII based on loop-mediated isothermal amplification (LAMP) was developed. The LAMP assay, performed using an apparatus with real-time amplification monitoring, was able to specifically detect LCDV genotype VII from clinically positive samples in less than 12 min. In addition, the assay allowed the detection of LCDV in all asymptomatic carrier fish analysed, identified by qPCR, showing an analytical sensitivity of ten copies of viral DNA per reaction. The LCDV LAMP assay has proven to be a promising diagnostic method that can be used easily in fish farms to detect the presence and spread of this iridovirus.

Is Technology-Mediated Parental Monitoring Related to Adolescent Substance Use?

PubMed

Rudi, Jessie; Dworkin, Jodi

2018-01-03

Prevention researchers have identified parental monitoring leading to parental knowledge to be a protective factor against adolescent substance use. In today's digital society, parental monitoring can occur using technology-mediated communication methods, such as text messaging, email, and social networking sites. The current study aimed to identify patterns, or clusters, of in-person and technology-mediated monitoring behaviors, and examine differences between the patterns (clusters) in adolescent substance use. Cross-sectional survey data were collected from 289 parents of adolescents using Facebook and Amazon Mechanical Turk (MTurk). Cluster analyses were computed to identify patterns of in-person and technology-mediated monitoring behaviors, and chi-square analyses were computed to examine differences in substance use between the identified clusters. Three monitoring clusters were identified: a moderate in-person and moderate technology-mediated monitoring cluster (moderate-moderate), a high in-person and high technology-mediated monitoring cluster (high-high), and a high in-person and low technology-mediated monitoring cluster (high-low). Higher frequency of technology-mediated parental monitoring was not associated with lower levels of substance use. Results show that higher levels of technology-mediated parental monitoring may not be associated with adolescent substance use.

A classical regression framework for mediation analysis: fitting one model to estimate mediation effects.

PubMed

Saunders, Christina T; Blume, Jeffrey D

2017-10-26

Mediation analysis explores the degree to which an exposure's effect on an outcome is diverted through a mediating variable. We describe a classical regression framework for conducting mediation analyses in which estimates of causal mediation effects and their variance are obtained from the fit of a single regression model. The vector of changes in exposure pathway coefficients, which we named the essential mediation components (EMCs), is used to estimate standard causal mediation effects. Because these effects are often simple functions of the EMCs, an analytical expression for their model-based variance follows directly. Given this formula, it is instructive to revisit the performance of routinely used variance approximations (e.g., delta method and resampling methods). Requiring the fit of only one model reduces the computation time required for complex mediation analyses and permits the use of a rich suite of regression tools that are not easily implemented on a system of three equations, as would be required in the Baron-Kenny framework. Using data from the BRAIN-ICU study, we provide examples to illustrate the advantages of this framework and compare it with the existing approaches. © The Author 2017. Published by Oxford University Press.

The bidirectional associations between state anger and rumination and the role of trait mindfulness.

PubMed

Borders, Ashley; Lu, Shou-En

2017-07-01

Rumination is associated with exacerbated angry mood. Angry moods may also trigger rumination. However, research has not empirically tested the bidirectional associations of state rumination and anger, as experience sampling methodology can do. We predicted that state anger and rumination would be bi-directionally associated, both concurrently and over time, even controlling for trait anger and rumination. In addition, because mindfulness is associated with rumination and anger at the bivariate level, we examined the effect of trait mindfulness on the bidirectional association between state rumination and anger. We examined two hypotheses: (i) state rumination mediates the effect of trait mindfulness on state anger; and (ii) trait mindfulness weakens, or moderates, the bidirectional associations between state rumination and anger. In an experience-sampling study, 200 college students reported their current ruminative thinking and angry mood several times a day for 7 days. Mixed model analyses indicated that state anger and rumination predicted each other concurrently. In cross-lagged analyses, previous anger did not uniquely predict current rumination; previous rumination predicted current anger, although the effect was small. In support of our hypothesis, state rumination mediated the association between trait mindfulness and state anger. Additionally, trait mindfulness moderated the concurrent and cross-lagged associations between state rumination and anger, although the results were complex. This study contributes new information about the complex interplay of rumination and anger. Findings also add support to the theory that mindfulness decreases emotional reactivity. Aggr. Behav. 43:342-351, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Talking about Quitting: Interpersonal Communication as a Mediator of Campaign Effects on Smokers’ Quit Behaviors

PubMed Central

Jeong, Michelle; Tan, Andy; Brennan, Emily; Gibson, Laura; Hornik, Robert C.

2015-01-01

This study examined the role of interpersonal communication in the context of a mass media anti-smoking campaign. Specifically, it explored whether conversations about campaign ads and/or about quitting mediated campaign exposure effects on two quitting behaviors (sought help to quit and tried to quit smoking completely), as well as the relationship between ad-related and quitting-related conversations. Data were collected prior to the campaign and monthly for 16 months during the campaign through cross-sectional telephone surveys among a sample of 3277 adult Philadelphian smokers. Follow-up interviews were conducted among 877 participants three months after their first survey. Cross-sectional and longitudinal mediation models with bootstrap procedures assessed the indirect effects of campaign exposure on outcomes through conversations, and of conversations about ads on outcomes through conversations about quitting. In addition, lagged regression analyses tested the causal direction of associations between the variables of interest. The results partially support hypotheses that conversations about quitting mediate campaign effects on quitting-related behaviors, and, in line with previous research, that conversations about the ads have indirect effects on quitting-related behaviors by triggering conversations about quitting. These findings demonstrate the importance of considering interpersonal communication as a route of campaign exposure effects when evaluating and designing future public health campaigns. PMID:26147367

What are the combined effects of negative emotions and illness cognitions on self-care in people with type 2 diabetes? A longitudinal structural equation model.

PubMed

Hudson, Joanna L; Bundy, Christine; Coventry, Peter; Dickens, Chris; Wood, Alex; Reeves, David

2016-07-01

To explore whether negative emotions mediate the effect of diabetes cognitions on diabetes self-care and conversely whether diabetes cognitions mediate the effect of negative emotions on diabetes self-care. Longitudinal observational study in adults with type 2 diabetes. Self-reported depression and anxiety (Diabetes Wellbeing Questionnaire), cognitions (Illness Perceptions Questionnaire-Revised; Beliefs about Medicines Questionnaire), and diabetes self-care (Summary of Diabetes Self-Care Activities Scale) were completed at baseline and six months. Analyses used structural equation modelling. Baseline medication concerns were associated with elevated symptoms of depression and anxiety at follow-up, but emotions did not mediate medication concern's effect on diabetes self-care. Baseline depression and anxiety symptoms were associated with specific diabetes cognitions over time, but these cognition domains did not mediate emotion's effect on diabetes self-care. Personal control remained independent of emotions and was associated with diabetes self-care over time. Negative emotions did not act directly or alongside cognitions to influence diabetes self-care. The reciprocal relationship between diabetes cognitions and emotions suggests cognitive restructuring, in addition to other mood management intervention techniques would likely improve the emotional wellbeing of adults with type 2 diabetes. Likewise, personal control beliefs are likely important intervention targets for improving self-care.

Arabidopsis WRKY33 Is a Key Transcriptional Regulator of Hormonal and Metabolic Responses toward Botrytis cinerea Infection1[W

PubMed Central

Birkenbihl, Rainer P.; Diezel, Celia; Somssich, Imre E.

2012-01-01

The Arabidopsis (Arabidopsis thaliana) transcription factor WRKY33 is essential for defense toward the necrotrophic fungus Botrytis cinerea. Here, we aimed at identifying early transcriptional responses mediated by WRKY33. Global expression profiling on susceptible wrky33 and resistant wild-type plants uncovered massive differential transcriptional reprogramming upon B. cinerea infection. Subsequent detailed kinetic analyses revealed that loss of WRKY33 function results in inappropriate activation of the salicylic acid (SA)-related host response and elevated SA levels post infection and in the down-regulation of jasmonic acid (JA)-associated responses at later stages. This down-regulation appears to involve direct activation of several jasmonate ZIM-domain genes, encoding repressors of the JA-response pathway, by loss of WRKY33 function and by additional SA-dependent WRKY factors. Moreover, genes involved in redox homeostasis, SA signaling, ethylene-JA-mediated cross-communication, and camalexin biosynthesis were identified as direct targets of WRKY33. Genetic studies indicate that although SA-mediated repression of the JA pathway may contribute to the susceptibility of wrky33 plants to B. cinerea, it is insufficient for WRKY33-mediated resistance. Thus, WRKY33 apparently directly targets other still unidentified components that are also critical for establishing full resistance toward this necrotroph. PMID:22392279

Human microcephaly protein RTTN interacts with STIL and is required to build full-length centrioles.

PubMed

Chen, Hsin-Yi; Wu, Chien-Ting; Tang, Chieh-Ju C; Lin, Yi-Nan; Wang, Won-Jing; Tang, Tang K

2017-08-15

Mutations in many centriolar protein-encoding genes cause primary microcephaly. Using super-resolution and electron microscopy, we find that the human microcephaly protein, RTTN, is recruited to the proximal end of the procentriole at early S phase, and is located at the inner luminal walls of centrioles. Further studies demonstrate that RTTN directly interacts with STIL and acts downstream of STIL-mediated centriole assembly. CRISPR/Cas9-mediated RTTN gene knockout in p53-deficient cells induce amplification of primitive procentriole bodies that lack the distal-half centriolar proteins, POC5 and POC1B. Additional analyses show that RTTN serves as an upstream effector of CEP295, which mediates the loading of POC1B and POC5 to the distal-half centrioles. Interestingly, the naturally occurring microcephaly-associated mutant, RTTN (A578P), shows a low affinity for STIL binding and blocks centriole assembly. These findings reveal that RTTN contributes to building full-length centrioles and illuminate the molecular mechanism through which the RTTN (A578P) mutation causes primary microcephaly.Mutations in many centriolar protein-encoding genes cause primary microcephaly. Here the authors show that human microcephaly protein RTTN directly interacts with STIL and acts downstream of STIL-mediated centriole assembly, contributing to building full-length centrioles.

Parenting practices in middle childhood mediate the relation between growing up with a parent having bipolar disorder and offspring psychopathology from childhood into early adulthood.

PubMed

Iacono, Vanessa; Beaulieu, Leah; Hodgins, Sheilagh; Ellenbogen, Mark A

2018-05-01

The offspring of parents with bipolar disorder (OBD) are at high risk for developing mental disorders. In addition to genetic factors, environmental risk is purported to be associated with these negative outcomes. However, few studies have examined this relation. Using concurrent and longitudinal data, we examined if support, structure, and control provided by parents in middle childhood mediated the relation between having a parent with or without bipolar disorder, and offspring mental health. The sample included 145 offspring (77 OBD, 68 controls) aged 4 to 14 years and their parents. Parent and teacher ratings of child behavior were collected, and diagnostic assessments were conducted in offspring 12 years later (n = 101). Bootstrapping analyses showed that low levels of structure mediated the relation between having a parent with bipolar disorder and elevated internalizing and externalizing difficulties during middle childhood. For the longitudinal outcomes, parental control emerged as the strongest mediator of the relation between parents' bipolar disorder and offspring psychopathology. Suboptimal childrearing may have different immediate and enduring consequences on mental health outcomes in the OBD. Parental structure has robust effects on emotional and behavioral problems in middle childhood, while levels of control promote psychological adjustment in the OBD as they mature.

The curvilinear relationship of early-life adversity and successful aging: the mediating role of mental health.

PubMed

Höltge, Jan; Mc Gee, Shauna L; Thoma, Myriam V

2018-02-15

The steeling effect suggests that early-life adversity can have a beneficial impact later in life. However, little is known about its underlying mechanisms and long-term outcomes . The study aimed to examine the role of early-life adversity (ELA) on successful aging, and whether this relationship can be explained by mental and physical health. Socio-demographics, early-life adversity (ELA), individual quality of life (iQoL), and mental and physical health of 270 individuals (M age = 66.82 years, 71.5% female) were assessed. Polynomial regressions and mediation analyses were conducted. Significant inverse U-shaped associations were found between ELA and iQoL (β = -.59, p = .005) and between ELA and mental health (β = -.64, p = .002), but not between ELA and physical health. Furthermore, mental health significantly mediated the relationship between ELA and iQoL (b = -.84, BCa CI [-1.66, -.27]). Highest level of individual quality of life (i.e. successful aging) was related to a moderate amount of ELA. Additionally, mental health significantly mediated this relationship. These findings suggest that some amount of ELA could be beneficial for successful aging. Resource-focused interventions are needed to improve health and promote successful aging for an underdetected, at-risk subgroup with low early-life adversity.

Relationship Between Adverse Childhood Experiences and Homelessness and the Impact of Axis I and II Disorders

PubMed Central

Roos, Leslie E.; Mota, Natalie; Afifi, Tracie O.; Katz, Laurence Y.; Distasio, Jino

2013-01-01

Objectives. We investigated the links between homelessness associated with serious mental and physical healthy disparities and adverse childhood experiences (ACEs) in nationally representative data, with Axis I and II disorders as potential mediators. Methods. We examined data from the National Epidemiologic Survey of Alcohol and Related Conditions in 2001–2002 and 2004–2005, and included 34 653 participants representative of the noninstitutionalized US population who were 20 years old or older. We studied the variables related to 4 classes of Axis I disorders, all 10 Axis II personality disorders, a wide range of ACEs, and a lifetime history of homelessness. Results. Analyses revealed high prevalences of each ACE in individuals experiencing lifetime homelessness (17%–60%). A mediation model with Axis I and II disorders determined that childhood adversities were significantly related to homelessness through direct effects (adjusted odd ratios = 2.04, 4.24) and indirect effects, indicating partial mediation. Population attributable fractions were also reported. Conclusions. Although Axis I and II disorders partially mediated the relationship between ACEs and homelessness, a strong direct association remained. This novel finding has implications for interventions and policy. Additional research is needed to understand relevant causal pathways. PMID:24148049

The effect of corporal punishment and verbal abuse on delinquency: mediating mechanisms.

PubMed

Evans, Sara Z; Simons, Leslie Gordon; Simons, Ronald L

2012-08-01

While the link between parenting and delinquency is well established, there is less consensus among scholars with regards to the processes that account for this link. The current study had two objectives. The first was to disentangle the effects of African American parents' use of corporal punishment and verbal abuse on the conduct problems of their preteen children. The second was to investigate the mechanisms that explain this relationship, such as having low self-control or a hostile view of relationships, whereby these harsh parenting practices increase a youth's involvement in problem behavior. Further, we are interested in specifically addressing how these mechanisms may operate differently for males versus females. Analyses utilized structural equation modeling and longitudinal data spanning approximately 2.5 years from a sample of 704 (54.2 % female) African American children ages 10-12. The results indicated that verbal abuse was a more important predictor of conduct problems than corporal punishment. Additionally, we found that the mechanisms that mediated the impact of verbal abuse and corporal punishment on conduct problems varied by gender. For males, most of the effect of verbal abuse was mediated by low self-control, whereas anger/frustration was the primary mediator for females. Implications of these results and directions for future study are also discussed.

An improved Agrobacterium-mediated transformation of recalcitrant indica rice (Oryza sativa L.) cultivars.

PubMed

Shri, Manju; Rai, Arti; Verma, Pankaj Kumar; Misra, Prashant; Dubey, Sonali; Kumar, Smita; Verma, Sikha; Gautam, Neelam; Tripathi, Rudra Deo; Trivedi, Prabodh Kumar; Chakrabarty, Debasis

2013-04-01

Agrobacterium-mediated transformation of indica rice varieties has been quite difficult as these are recalcitrant to in vitro responses. In the present study, we established a high-efficiency Agrobacterium tumefaciens-mediated transformation system of rice (Oryza sativa L. ssp. indica) cv. IR-64, Lalat, and IET-4786. Agrobacterium strain EHA-101 harboring binary vector pIG121-Hm, containing a gene encoding for β-glucuronidase (GUS) and hygromycin resistance, was used in the transformation experiments. Manipulation of different concentrations of acetosyringone, days of co-culture period, bacterial suspension of different optical densities (ODs), and the concentrations of L-cysteine in liquid followed by solid co-culture medium was done for establishing the protocol. Among the different co-culture periods, 5 days of co-culture with bacterial cells (OD600 nm = 0.5-0.8) promoted the highest frequency of transformation (83.04 %) in medium containing L-cysteine (400 mg l(-1)). Putative transformed plants were analyzed for the presence of a transgene through genomic PCR and GUS histochemical analyses. Our results also suggest that different cultural conditions and the addition of L-cysteine in the co-culture medium improve the Agrobacterium-mediated transformation frequencies from an average of 12.82 % to 33.33 % in different indica rice cultivars.

The Mediating and Moderating Effects of Workplace Social Capital on the Associations between Adverse Work Characteristics and Psychological Distress among Japanese Workers

PubMed Central

OSHIO, Takashi; INOUE, Akiomi; TSUTSUMI, Akizumi

2014-01-01

Our current study investigated how workplace social capital (WSC) mediates and moderates the associations between adverse work characteristics and psychological distress among Japanese workers. We collected cross-sectional data (N=9,350) from a baseline survey of an occupational Japanese cohort study. We focused on individual WSC and considered job demands/control, effort/reward, and two types (i.e., procedural and interactional) of organizational justice as work-characteristic variables. We defined psychological distress as a score of ≥5 on the Kessler Psychological Distress Scale (K6 scale). Multivariate logistic regression analyses predicted a binary variable of psychological distress by individual WSC and adverse work characteristics, adjusting for individual-level covariates. Individual WSC mediated the associations between adverse work characteristics and psychological distress in almost all model specifications. Additionally, individual WSC moderated the associations of psychological distress with high job demands, high effort, and low interactional justice when we used a high WSC cutoff point. In contrast, individual WSC did not moderate such interactions with low job control, reward, or procedural justice. We concluded that individual WSC mediated the associations between adverse work characteristics and psychological distress among Japanese workers while selectively moderating their associations at high levels of WSC. PMID:24705803

Interventions based on self-management of well-being theory: pooling data to demonstrate mediation and ceiling effects, and to compare formats.

PubMed

Goedendorp, M M; Steverink, N

2017-09-01

Interventions based on self-management of well-being (SMW) theory have shown positive effects, but additional questions remain: (1) Are improvements in well-being, as induced by the interventions, mediated by improved self-management ability (SMA)? (2) Do the interventions show ceiling effects? (3) Is a particular format of SMW intervention (individual, group, or self-help) more effective? Data of three randomized controlled trials were pooled. The greater part of the sample (N = 445) consisted of single older females. A bootstrap analysis was performed to test for mediation. Regression analyses with interaction effects were performed to test for ceiling effects. Controlled and transformed effect sizes (proportion of maximum change) were calculated to compare formats. There was a full significant mediation of well-being by SMA. A significant interaction (ceiling) effect was found on well-being, but not on SMA. The controlled effect sizes of the raw scores were small to medium (.04-.49), and were small to large after transformation (.41-.73). None of the intervention formats was more effective. Support for SMW theory was found, i.e. increasing self-management ability lead to improved well-being. Some ceiling effect was found. We conclude that various SMW interventions formats can improve self-management abilities and well-being with medium effects.

Dyadic adjustment and parenting stress in internationally adoptive mothers and fathers: the mediating role of adult attachment dimensions

PubMed Central

Salcuni, Silvia; Miconi, Diana; Altoè, Gianmarco; Moscardino, Ughetta

2015-01-01

Previous research has shown that a positive marital functioning represents a resource in adoptive families, leading to a decrease in parenting stress, but little is known about the factors mediating such a relationship. This study aimed to explore whether adult attachment avoidance and anxiety mediate the effect of dyadic functioning on parenting stress in 90 internationally adoptive couples (mothers and fathers) who had adopted a child (aged 3–10 years) in the last 36 months. Participants completed self-report measures of dyadic adjustment, adult attachment, and parenting stress. A series of path analyses supported the mediation hypothesis, but differentially for mothers and fathers. Among mothers, there was a direct and negative relationship between dyadic adjustment and parenting stress. In addition, a better dyadic adjustment was related to lower levels of attachment anxiety, which in turn were associated with less parenting stress. Among fathers, increased dyadic adjustment was related to lower levels of attachment avoidance, which in turn were associated with reduced parenting stress. These findings suggest the importance of including both mothers and fathers in adoption research. Adoptive parents could benefit from specific interventions aimed at reducing attachment avoidance and anxiety by supporting parental sense of competence and involvement for mothers and fathers, respectively. PMID:26388799

Spiritual stress and coping model of divorce: a longitudinal study.

PubMed

Krumrei, Elizabeth J; Mahoney, Annette; Pargament, Kenneth I

2011-12-01

This study represents the first longitudinal effort to use a spiritual stress and coping model to predict adults' psychosocial adjustment following divorce. A community sample of 89 participants completed measures at the time of their divorce and 1 year later. Though the sample endorsed slightly lower levels of religiosity than the general U.S. population, most reported spiritual appraisals and positive and negative religious coping tied to divorce. Hierarchical regression analyses controlling general religiousness and nonreligious forms of coping indicated that (a) appraising divorce as a sacred loss or desecration at the time it occurred predicted more depressive symptoms and dysfunctional conflict tactics with the ex-spouse 1 year later; (b) positive religious coping reported about the year following divorce predicted greater posttraumatic growth 1 year after divorce; and (c) negative religious coping reported about the year following divorce predicted more depressive symptoms 1 year after the divorce. Bootstrapping mediation analyses indicated that negative religious coping fully mediated links between appraising the divorce as a sacred loss or desecration at the time it occurred and depressive symptoms 1 year later. In addition, moderation analyses revealed that negative religious coping is more strongly associated with depressive symptoms among those who form high versus low appraisals of their divorce as a sacred loss or desecration. These findings are relevant to divorce education and intervention provided by professionals in legal, family, mental health, and clerical roles. Implications are discussed for clinical and counseling psychology and religious communities.

Failed reciprocity in close social relationships and health: findings from the Whitehall II study.

PubMed

Chandola, Tarani; Marmot, Michael; Siegrist, Johannes

2007-10-01

To extend the model of effort-reward imbalance at work to close and more general social relationships and test the associations with different measures of health. Lack of reciprocity at work is associated with poorer health in a number of studies. However, few studies have analysed the effect of nonreciprocity in other kinds of social relationships on health. The Whitehall II Study is an ongoing prospective study of British civil servants (n=10308 at baseline in 1985-88). Cross-sectional data from the latest phase (7, n=6944 in 2002-04) were used in the analyses. The main exposure was a questionnaire measuring nonreciprocal social relations in partnership, parent-children, and general trusting relationships. Health measures included the SF-36 mental and physical component scores, General Health Questionnaire-30 depression subscale, Jenkins' Sleep disturbance questionnaire, and the Rose Angina questionnaire. Logistic and linear regression models were analysed, adjusted for potential confounders, and mediators of the association. Lack of reciprocity is associated with all measures of poorer health. This association attenuates after adjustment for previous health and additional confounders and mediators but remains significant in a majority of models. Negative social support from a close person is independently associated with reduced health, but adjusting for this effect does not eliminate the association of nonreciprocity with poor health. The effort-reward imbalance at work model has been extended to close and more general social relationships. Lack of reciprocity in partnership, parent-children and general trusting relationships is associated with poorer health.

Ten Ways to Improve the Use of Statistical Mediation Analysis in the Practice of Child and Adolescent Treatment Research

ERIC Educational Resources Information Center

Maric, Marija; Wiers, Reinout W.; Prins, Pier J. M.

2012-01-01

Despite guidelines and repeated calls from the literature, statistical mediation analysis in youth treatment outcome research is rare. Even more concerning is that many studies that "have" reported mediation analyses do not fulfill basic requirements for mediation analysis, providing inconclusive data and clinical implications. As a result, after…

Do smoking and fruit and vegetable intake mediate the association between socio-economic status and plasma carotenoids?

PubMed

Kvaavik, Elisabeth; Totland, Torunn H; Bastani, Nasser; Kjøllesdal, Marte K; Tell, Grethe S; Andersen, Lene F

2014-08-01

The aim was to study whether the association between educational attainment and antioxidant status is mediated by smoking and fruit and vegetable intake. Cross-sectional analyses of the Oslo Youth Study 2006 wave were carried out. Information about education, smoking habits and diet was collected by questionnaire for 261 subjects (142 women and 119 men aged 38-42 years). Blood samples, height and weight measurements were taken by the participants' General Practitioner. Blood were analysed for plasma carotenoids. Linear regression analyses were used to examine whether smoking and fruit and vegetable intake mediate the association between education and plasma carotenoids. Educational level was positively associated with β-cryptoxanthin, α-carotene and lutein/zeaxanthin, but not with total carotenoids, β-carotene or lycopene. Education was negatively associated with smoking and positively associated with fruit and vegetable intake. Smoking was negatively associated with β-cryptoxanthin, and fruit and vegetable intake was positively associated with β-cryptoxanthin (adjusted for educational level). Moreover, cigarette consumption mediated the association between education and β-cryptoxanthin by 37%, while fruit and vegetable intake mediated this association by 18%. The total mediation effect was 55%. Smoking seemed to be more important as a mediator between education and plasma levels of β-cryptoxanthin than the intake of fruit and vegetables, but more studies are needed to establish the relative importance of smoking and diet as mediators of the association between education and antioxidant status. © The Author 2013. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Understanding and Using Mediators and Moderators

ERIC Educational Resources Information Center

Wu, Amery D.; Zumbo, Bruno D.

2008-01-01

Mediation and moderation are two theories for refining and understanding a causal relationship. Empirical investigation of mediators and moderators requires an integrated research design rather than the data analyses driven approach often seen in the literature. This paper described the conceptual foundation, research design, data analysis, as…

Brief Intervention for Drug Abusing Adolescents in a School Setting: Outcomes and Mediating Factors

PubMed Central

Winters, Ken C.; Fahnhorst, Tamara; Botzet, Andria; Lee, Susanne; Lalone, Britani

2011-01-01

This randomized controlled trial evaluated the use of two brief intervention conditions for adolescents (aged 12–18 years) who have been identified in a school setting as abusing alcohol and other drugs. Adolescents and their parent (N = 315) were randomly assigned to receive either a 2-session adolescent only (BI-A), 2-session adolescent and additional parent session (BI-AP), or assessment only control condition (CON). Interventions were manually guided and delivered in a school setting by trained counselors. Adolescents and parents were assessed at intake and at 6 months following the completion of the intervention. Analyses of relative (change from intake to 6-months) and absolute (status at 6-months) outcome variables indicated that for the most part, adolescents in the BI-A and BI-AP conditions showed significantly more reductions in drug use behaviors compared to the CON group. Also, youth receiving the BI-AP condition showed significantly better outcomes compared to the BI-A group on several variables. Problem-solving skills and utilization of additional counseling services mediated outcome. The value of a school-based brief intervention for students is discussed. PMID:22000326

Self-enhancement among high-exposure survivors of the September 11th terrorist attack: resilience or social maladjustment?

PubMed

Bonanno, George A; Rennicke, Courtney; Dekel, Sharon

2005-06-01

The authors examined self-enhancing bias as a predictor of adjustment among individuals in or near the World Trade Center during the September 11, 2001, terrorist attacks. Resilience was defined from categorical and continuous analyses of both participant self-report and friend and relative ratings of adjustment. Self-enhancement was associated with a resilient outcome, ratings of better adjustment prior to September 11th, greater positive affect, and reduced perceptions of social constraints. Additional analyses indicated that self-enhancers' reduced symptom levels were fully mediated by their low perceived social constraints. However, consistent with previous evidence suggesting a social cost to self-enhancement, at 18 months post-September 11th, self-enhancers' friends and relatives also rated them as decreasing in social adjustment and as being less honest.

Violence against teachers: prevalence and consequences.

PubMed

Wilson, Catherine M; Douglas, Kevin S; Lyon, David R

2011-08-01

Data collected from 731 teachers were used to examine the consequences of violence directed toward teachers while in the workplace. Analyses showed that the majority of respondents (n = 585, 80.0%) had experienced school-related violence—broadly defined—at one point in their careers. Serious violence (actual, attempted, or threatened physical violence) was less common, but still common enough to be of concern (n = 202, 27.6%). Violence predicted physical and emotional effects, as well as teaching-related functioning. In addition, a model with fear as a potential mediator revealed that both fear and violence were independently predictive of these negative outcomes. Finally, analyses showed that, in general, women reported higher levels of physical symptoms compared to men. We discuss the implications of violence against teachers in terms of personal consequences and the implications for mental health professionals working in an educational setting.

The influence of inattention and rapid automatized naming on reading performance.

PubMed

Pham, Andy V; Fine, Jodene Goldenring; Semrud-Clikeman, Margaret

2011-04-01

The current study examined the relation between attention, rapid automatized naming (RAN), and reading fluency among typically developing children. A total of 104 third- and fourth-grade children (8-11 years of age) completed RAN measures consisting of four stimuli (letter, digit, color, and object) and an oral reading fluency measure from the Gray Oral Reading Test-Fourth Edition. Correlational and hierarchical regression analyses revealed that all four RAN stimuli, particularly letter RAN, were significant predictors of reading fluency. Additionally, parent and teacher ratings of inattention from the Swanson, Nolan and Pelham-Version Four rating scale predicted RAN after controlling for gender, working memory, and estimated IQ. Further analyses indicated that RAN performance mediated the relation between inattention and reading fluency. Results support the need to consider attentional variables when assessing reading performance, even among typically developing children.

Friends' Alcohol-Related Social Networking Site Activity Predicts Escalations in Adolescent Drinking: Mediation by Peer Norms.

PubMed

Nesi, Jacqueline; Rothenberg, W Andrew; Hussong, Andrea M; Jackson, Kristina M

2017-06-01

Adolescents' increased use of social networking sites (SNS) coincides with a developmental period of heightened risk for alcohol use initiation. However, little is known regarding associations between adolescents' SNS use and drinking initiation nor the mechanisms of this association. This study examined longitudinal associations among adolescents' exposure to friends' alcohol-related SNS postings, alcohol-favorable peer injunctive norms, and initiation of drinking behaviors. Participants were 658 high-school students who reported on posting of alcohol-related SNS content by self and friends, alcohol-related injunctive norms, and other developmental risk factors for alcohol use at two time points, 1 year apart. Participants also reported on initiation of three drinking behaviors: consuming a full drink, becoming drunk, and heavy episodic drinking (three or more drinks per occasion). Probit regression analyses were used to predict initiation of drinking behaviors from exposure to alcohol-related SNS content. Path analyses examined mediation of this association by peer injunctive norms. Exposure to friends' alcohol-related SNS content predicted adolescents' initiation of drinking and heavy episodic drinking 1 year later, controlling for demographic and known developmental risk factors for alcohol use (i.e., parental monitoring and peer orientation). In addition, alcohol-favorable peer injunctive norms statistically mediated the relationship between alcohol-related SNS exposure and each drinking milestone. Results suggest that social media plays a unique role in contributing to peer influence processes surrounding alcohol use and highlight the need for future investigative and preventive efforts to account for adolescents' changing social environments. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Mechanisms of Behavior Change in Alcoholics Anonymous: Does AA lead to better alcohol use outcomes by reducing depression symptoms?

PubMed Central

Kelly, John F.; Stout, Robert L.; Magill, Molly; Tonigan, J. Scott; Pagano, Maria E.

2009-01-01

Rationale Indices of negative affect, such as depression, have been implicated in stress-induced pathways to alcohol relapse. Empirically-supported continuing care resources, such as Alcoholics Anonymous (AA), emphasize reducing negative affect to reduce relapse risk, but little research has been conducted to examine putative affective mechanisms of AA’s effects. Method Using lagged, controlled, hierarchical linear modeling and mediational analyses this study investigated whether AA participation mobilized changes in depression symptoms and whether such changes explained subsequent reductions in alcohol use. Alcohol dependent adults (N = 1,706), receiving treatment as part of a clinical trial, were assessed at intake, 3, 6, 9, 12, and 15 months. Results Findings revealed elevated levels of depression compared to the general population, which decreased during treatment and then remained stable over follow-up. Greater AA attendance was associated with better subsequent alcohol use outcomes and decreased depression. Greater depression was associated with heavier and more frequent drinking. Lagged, mediation analyses revealed that the effects of AA on alcohol use was partially mediated by reductions in depression symptoms. However, this salutary effect on depression itself appeared to be explained by AA’s proximal effect on reducing concurrent drinking. Conclusions AA attendance was both concurrently and predictively associated with improved alcohol outcomes. Although AA attendance was additionally associated with subsequent improvements in depression, it did not predict such improvements over and above concurrent alcohol use. AA appears to lead both to improvements in alcohol use and psychological and emotional well-being, which, in turn, may reinforce further abstinence and recovery-related change. PMID:20102345

Low heart rate variability and cancer-related fatigue in breast cancer survivors

PubMed Central

Crosswell, Alexandra D.; Lockwood, Kimberly G.; Ganz, Patricia A.; Bower, Julienne E.

2015-01-01

Cancer-related fatigue is a common and often long lasting symptom for many breast cancer survivors. Fatigued survivors show evidence of elevated inflammation, but the physiological mechanisms driving inflammatory activity have not been determined. Alterations in the autonomic nervous system, and particularly parasympathetic nervous system activity, are a plausible, yet understudied contributor to cancer-related fatigue. The goal of this study was to replicate one previous study showing an association between lower parasympathetic activity and higher fatigue in breast cancer survivors (Fagundes et al., 2011), and to examine whether inflammation mediates this association. Study participants were drawn from two samples and included 84 women originally diagnosed with early-stage breast cancer prior to age 50. Participants completed questionnaires, provided blood samples for determination of interleukin (IL)-6 and C-reactive protein (CRP), and underwent electrocardiography (ECG) assessment for evaluation of resting heart rate variability (HRV), a measure of parasympathetic activity. Results showed that lower HRV was associated with higher fatigue (p < .05), as predicted. In bivariate analyses, HRV was also correlated with circulating concentrations of IL-6 and CRP. However, path analyses did not support inflammation as a mediator of the association between HRV and fatigue; instead, associations among these variables appeared to be driven by age and BMI. These findings identify HRV as a potential contributor to cancer-related fatigue, but suggest that inflammation does not mediate this association in younger, healthy breast cancer survivors who are several years post-treatment. The autonomic nervous system merits additional attention in research on the etiology of cancer-related fatigue. PMID:24845177

The ties that bind: perceived social support, stress, and IBS in severely affected patients

PubMed Central

LACKNER, J. M.; BRASEL, A. M.; QUIGLEY, B M.; KEEFER, L.; KRASNER, S. S.; POWELL, C.; KATZ, L. A.; SITRIN, M. D.

2016-01-01

Background This study assessed the association between social support and the severity of irritable bowel syndrome (IBS) symptoms in a sample of severely affected IBS patients recruited to an NIH-funded clinical trial. In addition, we examined if the effects of social support on IBS pain are mediated through the effects on stress. Methods Subjects were 105 Rome II diagnosed IBS patients (F = 85%) who completed seven questionnaires which were collected as part of a pretreatment baseline assessment. Key Results Partial correlations were conducted to clarify the relationships between social support and clinically relevant variables with baseline levels of psychopathology, holding constant number of comorbid medical diseases, age, gender, marital status, ethnicity, and education. Analyses indicated that social support was inversely related to IBS symptom severity. Social support was positively related with less severe pain. A similar pattern of data was found for perceived stress but not quality of life impairment. Regression analyses examined if the effects of social support on pain are mediated by stress. The effects of social support on bodily pain were mediated by stress such that the greater the social support the less stress and the less pain. This effect did not hold for symptom severity, quality of life, or psychological distress. Conclusions & Inferences This study links the perceived adequacy of social support to the global severity of symptoms of IBS and its cardinal symptom (pain). It also suggests that the mechanism by which social support alleviates pain is through a reduction in stress levels. PMID:20465594

Effects of Calendula officinalis on human gingival fibroblasts.

PubMed

Saini, Pragtipal; Al-Shibani, Nouf; Sun, Jun; Zhang, Weiping; Song, Fengyu; Gregson, Karen S; Windsor, L Jack

2012-04-01

Calendula officinalis is commonly called the marigold. It is a staple topical remedy in homeopathic medicine. It is rich in quercetin, carotenoids, lutein, lycopene, rutin, ubiquinone, xanthophylls, and other anti-oxidants. It has anti-inflammatory properties. Quercetin, one of the active components in Calendula, has been shown to inhibit recombinant human matrix metalloproteinase (MMP) activity and decrease the expression of tumor necrosis factor-α, interleukin-1β (IL), IL-6 and IL-8 in phorbol 12-myristate 13-acetate and calcium ionophore-stimulated human mast cells. To examine the effects of Calendula on human gingival fibroblast (HGF) mediated collagen degradation and MMP activity. Lactate dehydrogenate assays were performed to determine the non-toxic concentrations of Calendula, doxycycline and quercetin. Cell-mediated collagen degradation assays were performed to examine the inhibitory effect on cell-mediated collagen degradation. Gelatin zymography was performed to examine their effects on MMP-2 activity. The experiments were repeated three times and ANOVA used for statistical analyses. Calendula at 2-3% completely inhibited the MMP-2 activity in the zymograms. Doxycycline inhibited HGF-mediated collagen degradation at 0.005, 0.01, 0.02 and 0.05%, and MMP-2 activity completely at 0.05%. Quercetin inhibited HGF-mediated collagen degradation at 0.005, 0.01 and 0.02%, and MMP-2 activity in a dose-dependent manner. Calendula inhibited HGF-mediated collagen degradation and MMP-2 activity more than the same correlated concentration of pure quercetin. Calendula inhibits HGF-mediated collagen degradation and MMP-2 activity more than the corresponding concentration of quercetin. This may be attributed to additional components in Calendula other than quercetin. Published by Elsevier Ltd.

The Mediating Role of Partner Communication Frequency on Condom Use Among African-American Adolescent Females Participating in an HIV Prevention Intervention

PubMed Central

Sales, Jessica M.; Lang, Delia L.; DiClemente, Ralph J.; Latham, Teaniese P; Wingood, Gina M.; Hardin, James W.; Rose, Eve S.

2011-01-01

Objective Although effective HIV prevention interventions have been developed for adolescents, few interventions have explored whether components of the intervention are responsible for the observed changes in behaviors post-intervention. This study examined the mediating role of partner communication frequency on African-American adolescent females’ condom use post-participation in a demonstrated efficacious HIV risk-reduction intervention. Main Outcome Measures Percent condom use in the past 60 days and consistent condom use in the past 6o days across the 12-month follow-up period. Design As part of a randomized controlled trial of African-American adolescent females (N=715), 15-21 years, seeking sexual health services, completed a computerized interview at baseline (prior to intervention) and again 6- and 12-month follow-up post-intervention participation. The interview assessed adolescents’ sexual behavior and partner communication skills, among other variables, at each time point. Using generalized estimating equation (GEE) techniques, both logistic and linear regression models were employed to test mediation over the 12-month follow-up period. Additional tests were conducted to assess the significance of the mediated models. Results Mediation analyses observed that partner communication frequency was a significant partial mediator of both proportion condom-protected sex acts (p =.001) and consistent condom use (p = .001). Conclusion Partner communication frequency, an integral component of this HIV intervention, significantly increased as a function of participating in the intervention partially explaining the change in condom use observed 12-months post-intervention. Understanding what intervention components are associated with behavior change is important for future intervention development. PMID:21843001

Changes in illness perceptions mediated the effect of cognitive behavioural therapy in severe functional somatic syndromes.

PubMed

Christensen, Sara Sletten; Frostholm, Lisbeth; Ørnbøl, Eva; Schröder, Andreas

2015-04-01

Although there is substantial evidence that cognitive behavioural therapy alleviates symptoms in functional somatic syndromes, the mechanisms of change are less investigated. This study examined whether changes in illness perceptions mediated the effect of cognitive behavioural therapy. We analysed additional data from a randomised controlled trial comparing completers of cognitive behavioural group therapy (46 patients) to an enhanced usual care group (66 patients). Proposed mediators (illness perceptions) and primary (physical health) and secondary (somatic symptoms and illness worry) outcomes were assessed by means of questionnaires at referral, baseline, end of treatment, and 10 and 16 months after randomisation. Multiple mediation analysis determined whether (1) changes in specific illness perceptions during treatment mediated the effect of cognitive behavioural therapy (primary analysis), and (2) whether changes in illness perceptions during the whole trial period were associated with improved outcome (secondary analysis). Improvements in illness perceptions during treatment partially mediated the effect of cognitive behavioural therapy on physical health one year after treatment (sum of indirect effects 1.556, BCa 95% CI (0.006; 3.620)). Improving perceived control was particularly important. Changes in illness perceptions from baseline to 16 months after randomisation were associated with clinically meaningful improvements in physical health, somatic symptoms and illness worry during the same period. Our results suggest that changing patients' illness perceptions is an important process in cognitive behavioural therapy for functional somatic syndromes. Challenging patients' own understanding of their illness may hence be a key element of successful treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

[Mediator effect of resilience between burnout and health in nursing staff].

PubMed

Arrogante, Óscar

2014-01-01

To determine the relationships between 3 burnout dimensions (Emotional Exhaustion, Depersonalization, and Reduced Personal Accomplishment), health (physical and mental health), and resilience, as well as to analyse the mediator role of resilience in relationships between burnout and health in a sample of Nursing staff. A correlational and cross-sectional study with probabilistic sampling was conducted on a sample of 194 Nursing staff of University Hospital of Fuenlabrada (Madrid), and composed of nurses (n=133) and nursing assistants (n=61). MBI-HSS (burnout syndrome), SF-12v1 (physical and mental components of health), 10-Item CD-RISC (resilience), and sociodemographic variables. Correlational analyses showed that mental health was negatively related with 3 burnout dimensions and positively with resilience. Furthermore, physical health was only negatively related with Emotional Exhaustion, and positively with resilience. Mediational analyses revealed that resilience mediated, on one hand, the relationship between Emotional Exhaustion and Depersonalization with mental health (partial mediation) and, on the other hand, the relationship between Reduced Personal Accomplishment and mental health (total mediation). Resilience is not only important to improve the mental health of Nursing staff, but also to buffer and minimize the negative consequences of the occupational stress to which they are at risk, with its most adverse result being signs of burnout. Therefore, resilience training should be promoted to improve nursing clinical practice. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Parental overprotection predicts the development of functional somatic symptoms in young adolescents.

PubMed

Janssens, Karin A M; Oldehinkel, Albertine J; Rosmalen, Judith G M

2009-06-01

To examine whether parental overprotection contributes to the development of functional somatic symptoms (FSS) in young adolescents. In addition, we aimed to study whether this potential effect of parental overprotection is mediated by parenting distress and/or moderated by the adolescent's sex. FSS were measured in 2230 adolescents (ages 10 to 12 years from the Tracking Adolescents' Individual Lives Survey) by the Somatic Complaints subscale of the Youth Self Report at baseline and at follow-up 2 1/2 years later. Parental overprotection as perceived by the child was assessed by means of the EMBU-C (Swedish acronym for my memories of upbringing-child version). Parents completed the Parenting Stress Index. Linear regression analyses were performed adjusted for FSS at baseline and sex. Parental overprotection was a predictor of the development of FSS in young adolescents (beta = 0.055, P < .01). Stratified analyses revealed that maternal overprotection was a predictor of the development of FSS in girls (beta = 0.085, P < .02), whereas paternal overprotection was a predictor of the development of FSS in boys (beta = 0.072, P < .01). A small (5.7%) but significant mediating effect of maternal parenting stress in the relationship between parental overprotection and FSS was found. Parental overprotection may play a role in the development of FSS in young adolescents.

Amelogenin exons 8 and 9 encoded peptide enhances leucine rich amelogenin peptide mediated dental pulp repair.

PubMed

Huang, Yulei; Goldberg, Michel; Le, Thuan; Qiang, Ran; Warner, Douglas; Witkowska, Halina Ewa; Liu, Haichuan; Zhu, Li; Denbesten, Pamela; Li, Wu

2012-01-01

Amelogenins containing exons 8 and 9 are alternatively spliced variants of amelogenin. Some amelogenin spliced variants have been found to promote pulp regeneration following pulp exposure. The function of the amelogenin spliced variants with the exons 8 and 9 remains unknown. In this study, we synthesized recombinant leucine rich amelogenin peptide (LRAP, A-4), LRAP plus exons 8 and 9 peptide (LRAP 8, 9) or exons 8 and 9 peptide (P89), to determine their effects on odontoblasts. In vivo analyses were completed following the insertion of agarose beads containing LRAP or LRAP 8, 9 into exposed cavity preparations of rat molars. After 8, 15 or 30 days' exposure, the pulp tissues were analyzed for changes in histomorphometry and cell proliferation by PCNA stainings. In vitro analyses included the effects of the addition of the recombinant proteins or peptide on cell proliferation, differentiation and adhesion of postnatal human dental pulp cells (DPCs). These studies showed that in vivo LRAP 8, 9 enhanced the reparative dentin formation as compared to LRAP. In vitro LRAP 8, 9 promoted DPC proliferation and differentiation to a greater extent than LRAP. These data suggest that amelogenin exons 8 and 9 may be useful in amelogenin-mediated pulp repair. Copyright © 2012 S. Karger AG, Basel.

Association Between Borderline Personality Features and Temporal Summation of Second Pain: A Cross-Sectional Study.

PubMed

You, Dokyoung S; Meagher, Mary W

2017-01-01

Individuals with greater borderline personality features may be vulnerable to chronic pain. Because pain is an unpleasant sensory and emotional experience, affect dysregulation as the core personality feature may be linked to pain hypersensitivity. Studies have found that greater borderline features are associated with increased intensity in clinical and experimental pain, and that depression mediates this increase. The current study further examined the association between borderline features and heat pain sensitivity, the contribution of affect dysregulation and the other borderline personality factors (identity problems, negative relationships, self-harming/impulsivity) to the association, and depression as a mediator. Additionally, we examined whether blunted sympathetic responses mediate the association between borderline features and temporal summation of second pain (TSSP). Thermal pain threshold, thermal TSSP and aftersensations pain were assessed in 79 healthy individuals with varying degrees of borderline features. TSSP is a proxy measure for central sensitization and refers to the gradual increase in pain to repeated nociceptive stimuli. A regression analysis showed that greater borderline features predicted greater TSSP (β = .22, p = .050, R 2 = .05). Borderline features were unrelated to pain threshold and TSSP decay. A stepwise regression showed greater TSSP in individuals with greater borderline features was accounted for by the negative relationships factor rather than the affect dysregulation factor. The results of mediational analyses showed depression and blunted sympathetic skin conductance responses mediated the positive association between TSSP and borderline features.

Emotional intelligence and depressive symptoms in Spanish institutionalized elders: does emotional self-efficacy act as a mediator?

PubMed Central

2016-01-01

Background. This work examines the relationship between emotional intelligence (EI) and depressive symptomatology in institutionalized older adults, delving into the mechanisms underlying this relationship. Considering that previous evidence of the variation of the EI-depression relationship depending on whether the emotional ability or the perception of that ability is evaluated, a model of multiple mediation was tested in which the dimensions of emotional self-efficacy (ESE) act as mediators in the relationship between ability EI and depressive symptomatology. Methods. The sample consisted of 115 institutionalized older adults (47.82% women; 80.3 ± 7.9 years of age) from the province of Jaén (Spain) who completed a test of ESE, a measure of ability EI, and a self-administered questionnaire of depressive symptoms. Results. The results showed a positive association between older adults’ emotional performance and depressive symptomatology, finding stronger associations with ESE than with EI abilities. In addition, multiple mediation analyses showed that two of the four dimensions of ESE fully mediated the relationship between ability EI and depressive symptoms. Discussion. These findings suggest that older adults’ high levels of emotional competence generate a feeling of ESE which can protect them against depressive symptoms. This work supports the predictive validity of emotional abilities and ESE for the mental health of a group that is particularly vulnerable to depression, institutionalized older adults. The limitations of the work are discussed, and future lines of research were considered. PMID:27547553

Linking and Psychological Functioning in a Chinese Sample: The Multiple Mediation of Response to Positive Affect

ERIC Educational Resources Information Center

Yang, Hongfei; Li, Juan

2016-01-01

The present study examined the associations between linking, response to positive affect, and psychological functioning in Chinese college students. The results of conducting multiple mediation analyses indicated that emotion- and self-focused positive rumination mediated the relationship between linking and psychological functioning, whereas…

Commentary: Mediation Analysis, Causal Process, and Cross-Sectional Data

ERIC Educational Resources Information Center

Shrout, Patrick E.

2011-01-01

Maxwell, Cole, and Mitchell (2011) extended the work of Maxwell and Cole (2007), which raised important questions about whether mediation analyses based on cross-sectional data can shed light on longitudinal mediation process. The latest article considers longitudinal processes that can only be partially explained by an intervening variable, and…

Anxiety, affect, self-esteem, and stress: mediation and moderation effects on depression.

PubMed

Nima, Ali Al; Rosenberg, Patricia; Archer, Trevor; Garcia, Danilo

2013-01-01

Mediation analysis investigates whether a variable (i.e., mediator) changes in regard to an independent variable, in turn, affecting a dependent variable. Moderation analysis, on the other hand, investigates whether the statistical interaction between independent variables predict a dependent variable. Although this difference between these two types of analysis is explicit in current literature, there is still confusion with regard to the mediating and moderating effects of different variables on depression. The purpose of this study was to assess the mediating and moderating effects of anxiety, stress, positive affect, and negative affect on depression. Two hundred and two university students (males  = 93, females  = 113) completed questionnaires assessing anxiety, stress, self-esteem, positive and negative affect, and depression. Mediation and moderation analyses were conducted using techniques based on standard multiple regression and hierarchical regression analyses. The results indicated that (i) anxiety partially mediated the effects of both stress and self-esteem upon depression, (ii) that stress partially mediated the effects of anxiety and positive affect upon depression, (iii) that stress completely mediated the effects of self-esteem on depression, and (iv) that there was a significant interaction between stress and negative affect, and between positive affect and negative affect upon depression. The study highlights different research questions that can be investigated depending on whether researchers decide to use the same variables as mediators and/or moderators.

Reducing self-objectification: are dissonance-based methods a possible approach?

PubMed Central

2013-01-01

Background Previous research has documented that self-objectification is associated with numerous negative outcomes including body shame, eating disorder (ED) pathology, and negative affect. This exploratory open study investigated whether or not an evidence-based body image improvement program that targets thin-ideal internalization in university women also reduces self-objectification. A second aim of the study was to determine if previous findings showing that body shame mediated the relationship between self-objectification and eating disorder pathology at a single time point (consistent with self-objectification theory) but did not mediate longitudinally (inconsistent with self-objectification theory) would be replicated in a new sample under novel conditions. Methods Ninety-six university women completed a peer-led dissonance-based intervention, along with assessment measures at pre-, post-intervention, 8-week and 8-month follow-up. To address the open trial nature of this study, a planned manipulation check was included to make sure that peer-led dissonance decreased thin-ideal internalization, body dissatisfaction, eating disorder pathology, and negative affect with effect sizes being similar to past randomized controlled trials. We hypothesized that all three subscales of the Objectified Body Consciousness Scale (i.e., self-surveillance, body shame, and appearance control beliefs) would be reduced. In addition, we hypothesized that body shame would mediate the relationship between self-objectification (i.e., self-surveillance) and eating disorder pathology at a both at a single time point and longitudinally. Results The planned manipulation check supported the interpretation that peer-led dissonance in this study largely yielded comparable changes to past controlled trials. In terms of changes in dependent variables, results supported all hypotheses with the exception of body shame, which remained unchanged. With regards to the mediation analyses, our first (cross-sectional) hypothesis but not our second (longitudinal) was supported. Conclusions Findings provide preliminary support for the use of dissonance interventions in reducing self-surveillance and body control beliefs. Results for body shame and the mediation analyses suggest that greater scrutiny of the body shame construct is warranted. PMID:24999392

Childhood maltreatment, psychological resources, and depressive symptoms in women with breast cancer.

PubMed

Kuhlman, Kate Ryan; Boyle, Chloe C; Irwin, Michael R; Ganz, Patricia A; Crespi, Catherine M; Asher, Arash; Petersen, Laura; Bower, Julienne E

2017-10-01

Childhood maltreatment is associated with elevated risk for depression across the human lifespan. Identifying the pathways through which childhood maltreatment relates to depressive symptoms may elucidate intervention targets that have the potential to reduce the lifelong negative health sequelae of maltreatment exposure. In this cross-sectional study, 271 women with early-stage breast cancer were assessed after their diagnosis but before the start of adjuvant treatment (chemotherapy, radiation, endocrine therapy). Participants completed measures of childhood maltreatment exposure, psychological resources (optimism, mastery, self-esteem, mindfulness), and depressive symptoms. Using multiple mediation analyses, we examined which psychological resources uniquely mediated the relationship between childhood maltreatment and depressive symptoms. Exposure to maltreatment during childhood was robustly associated with lower psychological resources and elevated depressive symptoms. Further, lower optimism and mindfulness mediated the association between childhood maltreatment and elevated depressive symptoms. These results support existing theory that childhood maltreatment is associated with lower psychological resources, which partially explains elevated depressive symptoms in a sample of women facing breast cancer diagnosis and treatment. These findings warrant replication in populations facing other major life events and highlight the need for additional studies examining childhood maltreatment as a moderator of treatment outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integrating mediation and moderation to advance theory development and testing.

PubMed

Karazsia, Bryan T; Berlin, Kristoffer S; Armstrong, Bridget; Janicke, David M; Darling, Katherine E

2014-03-01

The concepts and associated analyses of mediation and moderation are important to the field of psychology. Although pediatric psychologists frequently incorporate mediation and moderation in their theories and empirical research, on few occasions have we integrated mediation and moderation. In this article, conceptual reasons for integrating mediation and moderation are offered. We illustrate a model that integrates mediation and moderation. In our illustration, the strength of an indirect or a mediating effect varied as a function of a moderating variable. Clinical implications of the integration of mediation and moderation are discussed, as is the potential of integrated models to advance research programs in pediatric psychology.

Mass spectrometric identification of proteins that interact through specific domains of the poly(A) binding protein

PubMed Central

Zhang, Chongxu; Nielsen, Maria E. O.; Chiang, Yueh-Chin; Kierkegaard, Morten; Wang, Xin; Lee, Darren J.; Andersen, Jens S.; Yao, Gang

2013-01-01

Poly(A) binding protein (PAB1) is involved in a number of RNA metabolic functions in eukaryotic cells and correspondingly is suggested to associate with a number of proteins. We have used mass spectrometric analysis to identify 55 non-ribosomal proteins that specifically interact with PAB1 from Saccharomyces cerevisiae. Because many of these factors may associate only indirectly with PAB1 by being components of the PAB1-mRNP structure, we additionally conducted mass spectrometric analyses on seven metabolically defined PAB1 deletion derivatives to delimit the interactions between these proteins and PAB1. These latter analyses identified 13 proteins whose associations with PAB1 were reduced by deleting one or another of PAB1’s defined domains. Included in this list of 13 proteins were the translation initiation factors eIF4G1 and eIF4G2, translation termination factor eRF3, and PBP2, all of whose previously known direct interactions with specific PAB1 domains were either confirmed, delimited, or extended. The remaining nine proteins that interacted through a specific PAB1 domain were CBF5, SLF1, UPF1, CBC1, SSD1, NOP77, yGR250c, NAB6, and GBP2. In further study, UPF1, involved in nonsense-mediated decay, was confirmed to interact with PAB1 through the RRM1 domain. We additionally established that while the RRM1 domain of PAB1 was required for UPF1-induced acceleration of deadenylation during nonsense-mediated decay, it was not required for the more critical step of acceleration of mRNA decapping. These results begin to identify the proteins most likely to interact with PAB1 and the domains of PAB1 through which these contacts are made. PMID:22836166

Mass spectrometric identification of proteins that interact through specific domains of the poly(A) binding protein.

PubMed

Richardson, Roy; Denis, Clyde L; Zhang, Chongxu; Nielsen, Maria E O; Chiang, Yueh-Chin; Kierkegaard, Morten; Wang, Xin; Lee, Darren J; Andersen, Jens S; Yao, Gang

2012-09-01

Poly(A) binding protein (PAB1) is involved in a number of RNA metabolic functions in eukaryotic cells and correspondingly is suggested to associate with a number of proteins. We have used mass spectrometric analysis to identify 55 non-ribosomal proteins that specifically interact with PAB1 from Saccharomyces cerevisiae. Because many of these factors may associate only indirectly with PAB1 by being components of the PAB1-mRNP structure, we additionally conducted mass spectrometric analyses on seven metabolically defined PAB1 deletion derivatives to delimit the interactions between these proteins and PAB1. These latter analyses identified 13 proteins whose associations with PAB1 were reduced by deleting one or another of PAB1's defined domains. Included in this list of 13 proteins were the translation initiation factors eIF4G1 and eIF4G2, translation termination factor eRF3, and PBP2, all of whose previously known direct interactions with specific PAB1 domains were either confirmed, delimited, or extended. The remaining nine proteins that interacted through a specific PAB1 domain were CBF5, SLF1, UPF1, CBC1, SSD1, NOP77, yGR250c, NAB6, and GBP2. In further study, UPF1, involved in nonsense-mediated decay, was confirmed to interact with PAB1 through the RRM1 domain. We additionally established that while the RRM1 domain of PAB1 was required for UPF1-induced acceleration of deadenylation during nonsense-mediated decay, it was not required for the more critical step of acceleration of mRNA decapping. These results begin to identify the proteins most likely to interact with PAB1 and the domains of PAB1 through which these contacts are made.

Reduced in vitro T-cell responses induced by glutaraldehyde-modified allergen extracts are caused mainly by retarded internalization of dendritic cells

PubMed Central

Heydenreich, Bärbel; Bellinghausen, Iris; Lorenz, Steffen; Henmar, Helene; Strand, Dennis; Würtzen, Peter A; Saloga, Joachim

2012-01-01

Although allergen-specific immunotherapy is a clinically effective therapy for IgE-mediated allergic diseases, the risk of IgE-mediated adverse effects still exists. For this reason, chemically modified allergoids have been introduced, which may destroy IgE-binding sites while T-cell activation should be retained. The aim of the study was to analyse the differences between intact allergens and differently modified/aggregated allergoids concerning their internalization as well as T-cell and basophil activation. For this purpose human monocyte-derived immature dendritic cells (DC) were incubated with Phleum pratense or Betula verrucosa pollen extract or with the corresponding allergoids, modified with formaldehyde or glutaraldehyde. After an additional maturation process, the antigen-loaded mature DC were co-cultured with autologous CD4+ T cells. Allergenicity was tested by leukotriene release from basophils. In addition, the uptake of intact allergens and allergoids by immature DC was analysed. The proliferation of, as well as the interleukin-4 (IL-4), IL-10, IL-13 and interferon-γ production by, CD4+ T cells which had been stimulated with glutaraldehyde allergoid-treated DC was reduced compared with CD4+ T cells stimulated with intact allergen-treated or formaldehyde allergoid-treated DC. In line with this, glutaraldehyde-modified allergoids were more aggregated and were internalized more slowly. Furthermore, only the allergoids modified with glutaraldehyde induced a decreased leukotriene release by activated basophils. These findings suggest that IgE-reactive epitopes were destroyed more efficiently by modification with glutaraldehyde than with formaldehyde under the conditions chosen for these investigations. Glutaraldehyde-modified allergoids also displayed lower T-cell stimulatory capacity, which is mainly the result of greater modification/aggregation and diminished uptake by DC. PMID:22348538

Reduced in vitro T-cell responses induced by glutaraldehyde-modified allergen extracts are caused mainly by retarded internalization of dendritic cells.

PubMed

Heydenreich, Bärbel; Bellinghausen, Iris; Lorenz, Steffen; Henmar, Helene; Strand, Dennis; Würtzen, Peter A; Saloga, Joachim

2012-06-01

Although allergen-specific immunotherapy is a clinically effective therapy for IgE-mediated allergic diseases, the risk of IgE-mediated adverse effects still exists. For this reason, chemically modified allergoids have been introduced, which may destroy IgE-binding sites while T-cell activation should be retained. The aim of the study was to analyse the differences between intact allergens and differently modified/aggregated allergoids concerning their internalization as well as T-cell and basophil activation. For this purpose human monocyte-derived immature dendritic cells (DC) were incubated with Phleum pratense or Betula verrucosa pollen extract or with the corresponding allergoids, modified with formaldehyde or glutaraldehyde. After an additional maturation process, the antigen-loaded mature DC were co-cultured with autologous CD4(+) T cells. Allergenicity was tested by leukotriene release from basophils. In addition, the uptake of intact allergens and allergoids by immature DC was analysed. The proliferation of, as well as the interleukin-4 (IL-4), IL-10, IL-13 and interferon-γ production by, CD4(+) T cells which had been stimulated with glutaraldehyde allergoid-treated DC was reduced compared with CD4(+) T cells stimulated with intact allergen-treated or formaldehyde allergoid-treated DC. In line with this, glutaraldehyde-modified allergoids were more aggregated and were internalized more slowly. Furthermore, only the allergoids modified with glutaraldehyde induced a decreased leukotriene release by activated basophils. These findings suggest that IgE-reactive epitopes were destroyed more efficiently by modification with glutaraldehyde than with formaldehyde under the conditions chosen for these investigations. Glutaraldehyde-modified allergoids also displayed lower T-cell stimulatory capacity, which is mainly the result of greater modification/aggregation and diminished uptake by DC. © 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.

Relationships among race, education, criminal thinking, and recidivism: moderator and mediator effects.

PubMed

Walters, Glenn D

2014-02-01

Moderator and mediator relationships linking variables from three different theoretical traditions-race (subcultural theory), education (life-course theory), and criminal thinking (social learning theory)-and recidivism were examined in 1,101 released male federal prison inmates. Preliminary regression analyses indicated that racial status (White, Black, Hispanic) moderated the relationship between criminal thinking, as measured by the General Criminal Thinking (GCT) score of the Psychological Inventory of Criminal Thinking Styles (PICTS), and recidivism. Further analysis, however, revealed that it was not racial status, per se, that moderated the relationship between the PICTS and recidivism, but educational attainment. Whereas the PICTS was largely effective in predicting recidivism in inmates with 12 or more years of education, it was largely ineffective in predicting recidivism in inmates with fewer than 12 years of education. When education and the GCT score were compared as possible mediators of the race-recidivism relationship only the GCT successfully mediated this relationship. Sensitivity testing showed that the GCT mediating effect was moderately robust to violations of the sequential ignorability assumption on which causal mediation analysis rests. Moderator and mediator analyses are potentially important avenues through which theoretical constructs can be integrated and assessment strategies devised.

Importance of Mediator complex in the regulation and integration of diverse signaling pathways in plants.

PubMed

Samanta, Subhasis; Thakur, Jitendra K

2015-01-01

Basic transcriptional machinery in eukaryotes is assisted by a number of cofactors, which either increase or decrease the rate of transcription. Mediator complex is one such cofactor, and recently has drawn a lot of interest because of its integrative power to converge different signaling pathways before channeling the transcription instructions to the RNA polymerase II machinery. Like yeast and metazoans, plants do possess the Mediator complex across the kingdom, and its isolation and subunit analyses have been reported from the model plant, Arabidopsis. Genetic, and molecular analyses have unraveled important regulatory roles of Mediator subunits at every stage of plant life cycle starting from flowering to embryo and organ development, to even size determination. It also contributes immensely to the survival of plants against different environmental vagaries by the timely activation of its resistance mechanisms. Here, we have provided an overview of plant Mediator complex starting from its discovery to regulation of stoichiometry of its subunits. We have also reviewed involvement of different Mediator subunits in different processes and pathways including defense response pathways evoked by diverse biotic cues. Wherever possible, attempts have been made to provide mechanistic insight of Mediator's involvement in these processes.

Importance of Mediator complex in the regulation and integration of diverse signaling pathways in plants

PubMed Central

Samanta, Subhasis; Thakur, Jitendra K.

2015-01-01

Basic transcriptional machinery in eukaryotes is assisted by a number of cofactors, which either increase or decrease the rate of transcription. Mediator complex is one such cofactor, and recently has drawn a lot of interest because of its integrative power to converge different signaling pathways before channeling the transcription instructions to the RNA polymerase II machinery. Like yeast and metazoans, plants do possess the Mediator complex across the kingdom, and its isolation and subunit analyses have been reported from the model plant, Arabidopsis. Genetic, and molecular analyses have unraveled important regulatory roles of Mediator subunits at every stage of plant life cycle starting from flowering to embryo and organ development, to even size determination. It also contributes immensely to the survival of plants against different environmental vagaries by the timely activation of its resistance mechanisms. Here, we have provided an overview of plant Mediator complex starting from its discovery to regulation of stoichiometry of its subunits. We have also reviewed involvement of different Mediator subunits in different processes and pathways including defense response pathways evoked by diverse biotic cues. Wherever possible, attempts have been made to provide mechanistic insight of Mediator's involvement in these processes. PMID:26442070

Testing Mediation Using Multiple Regression and Structural Equation Modeling Analyses in Secondary Data

ERIC Educational Resources Information Center

Li, Spencer D.

2011-01-01

Mediation analysis in child and adolescent development research is possible using large secondary data sets. This article provides an overview of two statistical methods commonly used to test mediated effects in secondary analysis: multiple regression and structural equation modeling (SEM). Two empirical studies are presented to illustrate the…

Power Analysis for Complex Mediational Designs Using Monte Carlo Methods

ERIC Educational Resources Information Center

Thoemmes, Felix; MacKinnon, David P.; Reiser, Mark R.

2010-01-01

Applied researchers often include mediation effects in applications of advanced methods such as latent variable models and linear growth curve models. Guidance on how to estimate statistical power to detect mediation for these models has not yet been addressed in the literature. We describe a general framework for power analyses for complex…

How Teacher Emotional Support Motivates Students: The Mediating Roles of Perceived Peer Relatedness, Autonomy Support, and Competence

ERIC Educational Resources Information Center

Ruzek, Erik A.; Hafen, Christopher A.; Allen, Joseph P.; Gregory, Anne; Mikami, Amori Yee; Pianta, Robert C.

2016-01-01

Multilevel mediation analyses test whether students' mid-year reports of classroom experiences of autonomy, relatedness with peers, and competence mediate associations between early in the school year emotionally-supportive teacher-student interactions (independently observed) and student-reported academic year changes in mastery motivation and…

An examination of mediators of the transfer of cognitive speed of processing training to everyday functional performance.

PubMed

Edwards, Jerri D; Ruva, Christine L; O'Brien, Jennifer L; Haley, Christine B; Lister, Jennifer J

2013-06-01

The purpose of these analyses was to examine mediators of the transfer of cognitive speed of processing training to improved everyday functional performance (J. D. Edwards, V. G. Wadley,, D. E. Vance, D. L. Roenker, & K. K. Ball, 2005, The impact of speed of processing training on cognitive and everyday performance. Aging & Mental Health, 9, 262-271). Cognitive speed of processing and visual attention (as measured by the Useful Field of View Test; UFOV) were examined as mediators of training transfer. Secondary data analyses were conducted from the Staying Keen in Later Life (SKILL) study, a randomized cohort study including 126 community dwelling adults 63 to 87 years of age. In the SKILL study, participants were randomized to an active control group or cognitive speed of processing training (SOPT), a nonverbal, computerized intervention involving perceptual practice of visual tasks. Prior analyses found significant effects of training as measured by the UFOV and Timed Instrumental Activities of Daily Living (TIADL) Tests. Results from the present analyses indicate that speed of processing for a divided attention task significantly mediated the effect of SOPT on everyday performance (e.g., TIADL) in a multiple mediation model accounting for 91% of the variance. These findings suggest that everyday functional improvements found from SOPT are directly attributable to improved UFOV performance, speed of processing for divided attention in particular. Targeting divided attention in cognitive interventions may be important to positively affect everyday functioning among older adults. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Regulation of androgen receptor and histone deacetylase 1 by Mdm2-mediated ubiquitylation.

PubMed

Gaughan, Luke; Logan, Ian R; Neal, David E; Robson, Craig N

2005-01-01

The androgen receptor (AR) is a member of the nuclear hormone receptor family of transcription factors and plays a critical role in regulating the expression of genes involved in androgen-dependent and -independent tumour formation. Regulation of the AR is achieved by alternate binding of either histone acetyltransferase (HAT)-containing co-activator proteins, or histone deacetylase 1 (HDAC1). Factors that control AR stability may also constitute an important regulatory mechanism, a notion that has been confirmed with the finding that the AR is a direct target for Mdm2-mediated ubiquitylation and proteolysis. Using chromatin immunoprecipitation (ChIP) and re-ChIP analyses, we show that Mdm2 associates with AR and HDAC1 at the active androgen-responsive PSA promoter in LNCaP prostate cancer cells. Furthermore, we demonstrate that Mdm2-mediated modification of AR and HDAC1 catalyses protein destabilization and attenuates AR sactivity, suggesting that ubiquitylation of the AR and HDAC1 may constitute an additional mechanism for regulating AR function. We also show that HDAC1 and Mdm2 function co-operatively to reduce AR-mediated transcription that is attenuated by the HAT activity of the AR co-activator Tip60, suggesting interplay between acetylation status and receptor ubiquitylation in AR regulation. In all, our data indicates a novel role for Mdm2 in regulating components of the AR transcriptosome.

'Not good enough:' Exploring self-criticism's role as a mediator between childhood emotional abuse & adult binge eating.

PubMed

Feinson, Marjorie C; Hornik-Lurie, Tzipi

2016-12-01

Empirical studies have identified emotional abuse in childhood (CEA) as a risk factor with long-term implications for psychological problems. Indeed, recent studies indicate it is more prevalent than behavioral forms of abuse, (i.e. childhood sexual and physical abuse) and the childhood trauma most clearly associated with subsequent eating pathology in adulthood. However, relatively little is understood about the mechanisms linking these distal experiences. This study explores three psychological mechanisms - self-criticism (SC), depression and anxiety symptoms - as plausible mediators that may account for the relationship between CEA and binge eating (BE) among adult women. Detailed telephone interviews conducted with a community-based sample of 498 adult women (mean age 44) assess BE, CEA and SC along with the most frequently researched psychological variables, anxiety and depression. Regression analyses reveal that BE is partially explained by CEA along with the three mediators. Bootstrapping analysis, which compares multiple mediators within a single model using thousands of repeated random sampling observations from the data set, reveals a striking finding: SC is the only psychological variable that makes a significant contribution to explaining BE severity. The unique role of punitive self-evaluations vis-à-vis binge eating warrants additional research and, in the interim, that clinicians consider broadening treatment interventions accordingly. Copyright © 2016. Published by Elsevier Ltd.

An investigation of vago-regulatory and health-behavior accounts for increased inflammation in posttraumatic stress disorder.

PubMed

Dennis, Paul A; Weinberg, J Brice; Calhoun, Patrick S; Watkins, Lana L; Sherwood, Andrew; Dennis, Michelle F; Beckham, Jean C

2016-04-01

Posttraumatic stress disorder (PTSD) has been linked to chronic inflammation, a condition that poses a risk for cardiovascular disease. Attenuated vagal activity has been proposed as a potential mediator of PTSD and inflammation, although associated behavioral health risks-namely cigarette smoking and alcohol dependence-might also account for that link. Inflammation was quantified by fasting serum concentrations of C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-10, and thymus- and activation-regulated chemokine (TARC)/CCL17 collected from 85 participants with PTSD and 82 without PTSD. Latent variable modeling was used to assess the relationship between PTSD symptom severity and inflammation along with potential mediators vagal activity (respiratory sinus arrhythmia; RSA), smoking status, and lifetime alcohol dependence. PTSD symptom severity was associated with increased inflammation (β=.18, p=.02). However, this association was reduced in models that adjusted for RSA, smoking status, and lifetime alcohol dependence. Independent mediation effects were deemed significant via bootstrapping analyses. Together, RSA, smoking status, and lifetime alcohol dependence accounted for 95% of the effect of PTSD symptom severity on inflammation. Although RSA accounted for a modest proportion of the association between posttraumatic stress and pro-inflammatory responses, behavioral factors-specifically cigarette smoking and alcohol dependence-proved to be larger mediators. The benefits of PTSD treatment may be enhanced by additional interventions aimed at modifying these health behaviors. Published by Elsevier Inc.

Predicting fruit consumption: the role of habits, previous behavior and mediation effects

PubMed Central

2014-01-01

Background This study assessed the role of habits and previous behavior in predicting fruit consumption as well as their additional predictive contribution besides socio-demographic and motivational factors. In the literature, habits are proposed as a stable construct that needs to be controlled for in longitudinal analyses that predict behavior. The aim of this study is to provide empirical evidence for the inclusion of either previous behavior or habits. Methods A random sample of 806 Dutch adults (>18 years) was invited by an online survey panel of a private research company to participate in an online study on fruit consumption. A longitudinal design (N = 574) was used with assessments at baseline and after one (T2) and two months (T3). Multivariate linear regression analysis was used to assess the differential value of habit and previous behavior in the prediction of fruit consumption. Results Eighty percent of habit strength could be explained by habit strength one month earlier, and 64% of fruit consumption could be explained by fruit consumption one month earlier. Regression analyses revealed that the model with motivational constructs explained 41% of the behavioral variance at T2 and 38% at T3. The addition of previous behavior and habit increased the explained variance up to 66% at T2 and to 59% at T3. Inclusion of these factors resulted in non-significant contributions of the motivational constructs. Furthermore, our findings showed that the effect of habit strength on future behavior was to a large extent mediated by previous behavior. Conclusions Both habit and previous behavior are important as predictors of future behavior, and as educational objectives for behavior change programs. Our results revealed less stability for the constructs over time than expected. Habit strength was to a large extent mediated by previous behavior and our results do not strongly suggest a need for the inclusion of both constructs. Future research needs to assess the conditions that determine direct influences of both previous behavior and habit, since these influences may differ per type of health behavior, per context stability in which the behavior is performed, and per time frame used for predicting future behavior. PMID:25037859

Personality and attention: Levels of neuroticism and extraversion can predict attentional performance during a change detection task.

PubMed

Hahn, Sowon; Buttaccio, Daniel R; Hahn, Jungwon; Lee, Taehun

2015-01-01

The present study demonstrates that levels of extraversion and neuroticism can predict attentional performance during a change detection task. After completing a change detection task built on the flicker paradigm, participants were assessed for personality traits using the Revised Eysenck Personality Questionnaire (EPQ-R). Multiple regression analyses revealed that higher levels of extraversion predict increased change detection accuracies, while higher levels of neuroticism predict decreased change detection accuracies. In addition, neurotic individuals exhibited decreased sensitivity A' and increased fixation dwell times. Hierarchical regression analyses further revealed that eye movement measures mediate the relationship between neuroticism and change detection accuracies. Based on the current results, we propose that neuroticism is associated with decreased attentional control over the visual field, presumably due to decreased attentional disengagement. Extraversion can predict increased attentional performance, but the effect is smaller than the relationship between neuroticism and attention.

Negative thinking as a coping strategy mediator of pain and internalizing symptoms in adolescents with sickle cell disease.

PubMed

Barakat, Lamia P; Schwartz, Lisa A; Simon, Katherine; Radcliffe, Jerilynn

2007-06-01

The objective of this study was to examine the role of coping strategies, specifically negative thinking, in mediating the association of pain with symptoms of anxiety and depression in adolescents with sickle cell disease. Fifty-two 12-18-year-old adolescents with sickle cell disease completed a daily pain diary and paper-and-pencil measures of pain, pain coping, depression and anxiety. Symptoms of depression and anxiety were within the non-clinical range. Preliminary analyses indicated that lower family income was associated with higher reports of pain and negative thinking. Mediation regression analyses supported negative thinking as mediating the association of: (1) pain intensity with depression, and (2) pain interference with daily activities with anxiety. Findings highlight negative thinking as a factor compromising adolescents' adaptation to sickle cell pain; however, further investigation is required to determine the mediating influence of pain coping. Associations for lower income emphasize the multiple risk factors experienced by many of these adolescents.

Do attentional capacities and processing speed mediate the effect of age on executive functioning?

PubMed

Gilsoul, Jessica; Simon, Jessica; Hogge, Michaël; Collette, Fabienne

2018-02-06

The executive processes are well known to decline with age, and similar data also exists for attentional capacities and processing speed. Therefore, we investigated whether these two last nonexecutive variables would mediate the effect of age on executive functions (inhibition, shifting, updating, and dual-task coordination). We administered a large battery of executive, attentional and processing speed tasks to 104 young and 71 older people, and we performed mediation analyses with variables showing a significant age effect. All executive and processing speed measures showed age-related effects while only the visual scanning task performance (selective attention) was explained by age when controlled for gender and educational level. Regarding mediation analyses, visual scanning partially mediated the age effect on updating while processing speed partially mediated the age effect on shifting, updating and dual-task coordination. In a more exploratory way, inhibition was also found to partially mediate the effect of age on the three other executive functions. Attention did not greatly influence executive functioning in aging while, in agreement with the literature, processing speed seems to be a major mediator of the age effect on these processes. Interestingly, the global pattern of results seems also to indicate an influence of inhibition but further studies are needed to confirm the role of that variable as a mediator and its relative importance by comparison with processing speed.

Interpersonal sensitivity mediates the effects of child abuse and affective temperaments on depressive symptoms in the general adult population.

PubMed

Otsuka, Ayano; Takaesu, Yoshikazu; Sato, Mitsuhiko; Masuya, Jiro; Ichiki, Masahiko; Kusumi, Ichiro; Inoue, Takeshi

2017-01-01

Recent studies have suggested that multiple factors interact with the onset and prognosis of major depressive disorders. In this study, we investigated how child abuse, affective temperaments, and interpersonal sensitivity are interrelated, and how they affect depressive symptoms in the general adult population. A total of 415 volunteers from the general adult population completed the Patient Health Questionnaire-9, the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Autoquestionnaire version, the Child Abuse and Trauma Scale, and the Interpersonal Sensitivity Measure, which are all self-administered questionnaires. Data were subjected to structural equation modeling (Mplus), and single and multiple regression analyses. The effect of child abuse on depressive symptoms was mediated by interpersonal sensitivity and 4 affective temperaments, including depressive, cyclothymic, anxious, and irritable temperaments. In addition, the effect of these temperaments on depressive symptoms was mediated by interpersonal sensitivity, indicating the indirect enhancement of depressive symptoms. In contrast to these 4 temperaments, the hyperthymic temperament did not mediate the effect of child abuse on depressive symptoms; its effect was not mediated by interpersonal sensitivity. However, a greater hyperthymic temperament predicted decreased depressive symptoms and interpersonal sensitivity, independent of any mediation effect. Because this is a cross-sectional study, long-term prospective studies are necessary to confirm its findings. Therefore, recall bias should be considered when interpreting the results. As the subjects were adults from the general population, the results may not be generalizable towards all patients with major depression. This study suggests that child abuse and affective temperaments affect depressive symptoms partly through interpersonal sensitivity. Interpersonal sensitivity may have a major role in forming the link between abuse, affective temperament, and depression.

Attitudes toward healthy eating: a mediator of the educational level-diet relationship.

PubMed

Lê, J; Dallongeville, J; Wagner, A; Arveiler, D; Haas, B; Cottel, D; Simon, C; Dauchet, L

2013-08-01

A higher educational level is associated with a healthier diet. The goal of this study was to establish whether this association is mediated by attitudes toward healthy eating. The cross-sectional MONA LISA-NUT study was performed in 2005-2007 on adults aged 35-64 years from northern and north-eastern France. Diet quality was assessed on the basis of a 3-day food record and a validated score based on French national dietary guidelines. Specific questions investigated attitudes toward healthy eating. Multivariate analyses were used to quantify the proportion of the educational level-diet relationship that was mediated by attitudes toward healthy eating. Among the 1631 subjects, favourable attitudes toward healthy eating were associated with both higher educational level and diet quality. In the mediation analysis, 'organic food consumption' explained 14% (95% confidence interval (8;24)) of the educational level-diet relationship and 'attention paid to health when buying food' explained 9% (3;16). In contrast, 'attention to food choice', 'searching for information about food' and 'perceived role of eating' were not mediators of the association between educational level and diet. In a multivariate model, the attitude items together accounted for 25% (10;45) of the relationship. The mediation was more pronounced in women than in men (37% (15;54) vs 16% (1;27), respectively) and was significant for consumption of fruits and vegetables (23% (13;37)), whole-grain food (32% (15;58)) and seafood (22% (9;55)). Our results suggest that poor attitudes toward healthy eating in groups with low socioeconomic status constitute an additional factor (along with cost constraints) in the choice of unhealthy foods.

Endogenous pro-resolving and anti-inflammatory lipid mediators: a new pharmacologic genus

PubMed Central

Serhan, C N; Chiang, N

2008-01-01

Complete resolution of an acute inflammatory response and its return to homeostasis are essential for healthy tissues. Here, we overview ongoing efforts to characterize cellular and molecular mechanisms that govern the resolution of self-limited inflammation. Systematic temporal analyses of evolving inflammatory exudates using mediator lipidomics-informatics, proteomics, and cellular trafficking with murine resolving exudates demonstrate novel endogenous pathways of local-acting mediators that share both anti-inflammatory and pro-resolving properties. In murine systems, resolving-exudate leukocytes switch their phenotype to actively generate new families of mediators from major omega-3 fatty acids EPA and DHA termed resolvins and protectins. Recent advances on their biosynthesis and actions are reviewed with a focus on the E-series resolvins (RvE1, RvE2), D series resolvins (RvD1, RvD2) and the protectins including neuroprotectin D1/protectin D1 (NPD1/PD1) as well as their aspirin-triggered epimeric forms. Members of each new family demonstrate potent stereo-specific actions, joining the lipoxins as endogenous local signals that govern resolution and endogenous anti-inflammation mechanisms. In addition to their origins and roles in resolution biology in the immune system, recent findings indicate that these new mediator families also display potent protective actions in lung, kidney, and eye as well as enhance microbial clearance. Thus, these endogenous agonists of resolution pathways constitute a novel genus of chemical mediators that possess pro-resolving, anti-inflammatory, and antifibrotic as well as host-directed antimicrobial actions. These may be useful in the design of new therapeutics and treatments for diseases with the underlying trait of uncontrolled inflammation and redox organ stress. PMID:17965751

Morphine-induced antinociception in the rat: supra-additive interactions with imidazoline I₂ receptor ligands.

PubMed

Li, Jun-Xu; Zhang, Yanan; Winter, Jerrold C

2011-11-01

Pain remains a significant clinical challenge and currently available analgesics are not adequate to meet clinical needs. Emerging evidence suggests the role of imidazoline I(2) receptors in pain modulation primarily from studies of the non-selective imidazoline receptor ligand, agmatine. However, little is known of the generality of the effect to selective I(2) receptor ligands. This study examined the antinociceptive effects of two selective I(2) receptor ligands 2-BFI and BU224 (>2000-fold selectivity for I(2) receptors over α(2) adrenoceptors) in a hypertonic (5%) saline-induced writhing test and analyzed their interaction with morphine using a dose-addition analysis. Morphine, 2-BFI and BU224 but not agmatine produced a dose-dependent antinociceptive effect. Both composite additive curve analyses and isobolographical plots revealed a supra-additive interaction between morphine and 2-BFI or BU224, whereas the interaction between 2-BFI and BU224 was additive. The antinociceptive effect of 2-BFI and BU224 was attenuated by the I(2) receptor antagonist/α(2) adrenoceptor antagonist idazoxan but not by the selective α(2) adrenoceptor antagonist yohimbine, suggesting an I(2) receptor-mediated mechanism. Agmatine enhanced the antinociceptive effect of morphine, 2-BFI and BU224 and the enhancement was prevented by yohimbine, suggesting that the effect was mediated by α(2) adrenoceptors. Taken together, these data represent the first report that selective I(2) receptor ligands have substantial antinociceptive activity and produce antinociceptive synergy with opioids in a rat model of acute pain. These data suggest that drugs acting on imidazoline I(2) receptors may be useful either alone or in combination with opioids for the treatment of pain. Copyright © 2011 Elsevier B.V. All rights reserved.

Self-reported peer victimization and suicidal ideation in adolescent psychiatric inpatients: the mediating role of negative self-esteem.

PubMed

Jones, Heather A; Bilge-Johnson, Sumru; Rabinovitch, Annie E; Fishel, Hazel

2014-10-01

The current study investigated relationships among self-reported peer victimization, suicidality, and depression in adolescent psychiatric inpatients. Sixty-seven adolescent psychiatric inpatients at a Midwestern children's hospital completed measures of bullying and peer victimization, suicidal ideation, and depression during their inpatient stay. Analyses indicated significant moderate correlations among victimization, suicidal ideation, and depression in adolescents. Results from mediational analyses found that negative self-esteem mediated the relationship between peer victimization and suicidal ideation. To date, this study is the first to directly examine the mechanisms underlying the relationship between peer victimization and suicidal ideation in adolescent psychiatric inpatients. © The Author(s) 2013.

Anxiety, Affect, Self-Esteem, and Stress: Mediation and Moderation Effects on Depression

PubMed Central

Nima, Ali Al; Rosenberg, Patricia; Archer, Trevor; Garcia, Danilo

2013-01-01

Background Mediation analysis investigates whether a variable (i.e., mediator) changes in regard to an independent variable, in turn, affecting a dependent variable. Moderation analysis, on the other hand, investigates whether the statistical interaction between independent variables predict a dependent variable. Although this difference between these two types of analysis is explicit in current literature, there is still confusion with regard to the mediating and moderating effects of different variables on depression. The purpose of this study was to assess the mediating and moderating effects of anxiety, stress, positive affect, and negative affect on depression. Methods Two hundred and two university students (males  = 93, females  = 113) completed questionnaires assessing anxiety, stress, self-esteem, positive and negative affect, and depression. Mediation and moderation analyses were conducted using techniques based on standard multiple regression and hierarchical regression analyses. Main Findings The results indicated that (i) anxiety partially mediated the effects of both stress and self-esteem upon depression, (ii) that stress partially mediated the effects of anxiety and positive affect upon depression, (iii) that stress completely mediated the effects of self-esteem on depression, and (iv) that there was a significant interaction between stress and negative affect, and between positive affect and negative affect upon depression. Conclusion The study highlights different research questions that can be investigated depending on whether researchers decide to use the same variables as mediators and/or moderators. PMID:24039896

Associations of sense of coherence with psychological distress and quality of life in inflammatory bowel disease.

PubMed

Freitas, Thiago H; Andreoulakis, Elias; Alves, Gilberto S; Miranda, Hesley L L; Braga, Lúcia L B C; Hyphantis, Thomas; Carvalho, André F

2015-06-07

To investigate the relationship between sense of coherence, psychological distress and health related quality of life in inflammatory bowel disease (IBD). This cross-sectional study enrolled a consecutive sample of 147 IBD (aged 45.1 ± 14.1 years; 57.1% female) patients recruited from a tertiary gastroenterology service. Sixty-four participants met diagnostic criteria for Crohn's disease, while eighty-three patients had ulcerative colitis. Socio-demographic data (education, age, race, gender, gross monthly income and marital status), disease-related variables (illness activity, relapse rate in past 2 years, history of surgery and time since diagnosis), sense of coherence (Antonovsky's SOC scale), psychological distress symptoms (Hospital Anxiety and Depression Scale) and health-related quality of life (HRQoL; WHOQOL-Bref) were assessed. Hierarchical multiple regression analyses were performed to identify factors that are independently associated with psychological distress and HRQoL in patients with IBD and to provide indications for possible moderating or mediating effects. In addition, formal moderation and mediation analyses (Sobel tests) were performed to confirm potential moderators/mediators of the relationship between SOC, psychological distress symptoms and HRQoL. Lower SOC scores (std beta= -0.504; P < 0.001), female gender (std beta = 0.176; P = 0.021) and White race (std beta = 0.164; P = 0.033) were independently associated with higher levels of depressive symptoms, while lower levels of SOC (std beta = -0.438; P < 0.001) and higher relapse rate (std beta = 0.161; P = 0.033) were independently associated with more severe anxiety symptoms. A significant interaction between time since diagnosis and SOC was found with regard to the severity of depressive or anxiety symptoms, as the interaction term (time since diagnosis X SOC) had beta coefficients of -0.191 (P = 0.009) and -0.172 (P = 0.026), respectively. Lower levels of anxiety symptoms (std beta = -0.369; P < 0.001), higher levels of SOC (std beta = 0.231; P = 0.016) and non-White race (std beta = -0.229; P = 0.006), i.e., mixed-race, which represented the reference category, were independently associated with higher levels of overall HRQoL. Anxiety symptoms were the most potent independent correlate of most aspects of HRQoL. In addition, anxiety mediated the association between SOC and satisfaction with health, as well as its relationship with physical, mental, and social relations HRQoL. Depressive symptoms also mediated the association between SOC and mental HRQoL. Our data indicated that SOC is an important construct, as it influences psychological distress and has significant albeit indirect effects on several HRQoL domains in IBD.

Association of childhood trauma and panic symptom severity in panic disorder: Exploring the mediating role of alexithymia.

PubMed

Zou, Zhili; Huang, Yulan; Wang, Jinyu; He, Ying; Min, Wenjiao; Chen, Xu; Wang, Jing; Zhou, Bo

2016-12-01

The aim of the present study was to examine the association between childhood trauma (CT), alexithymia, and panic symptom severity in patients with panic disorder (PD). Moreover, the effect of specific subtypes of CT on alexithymia and panic symptom severity was also investigated. 142 patients with PD and 146 healthy age-matched and sex-matched controls were enrolled in the study. The Structured Clinical Interview for DSM-IV axis I (SCID-I), Childhood Trauma Questionnaire-28 item Short Form (CTQ-28), Toronto Alexithymia Scale (TAS-20), and Panic Disorder Severity Scale (PDSS) were administered to all subjects. The relationships among CT subtypes, alexithymia, and panic symptom severity were investigated using Pearson's correlation analysis. The types of CT that predict alexithymia and panic symptom severity were also investigated using Regression analyses. PD patients showed higher scores on reporting all kinds of CT except sexual abuse. In addition, the TAS-20, DIF (difficulty identifying feelings) and DDF (difficulty describing feelings) scores were significantly higher in patients with PD than in controls. Significant positive correlations were noted among CT, alexithymia and panic symptoms severity. Results of regression analyses showed alexithymia as a mediator between the different types of CT and panic disorder severity, except sexual abuse. Although self-report questionnaires are reliable and widely used, the phenomenon of patients who underreport or overreport their symptoms cannot be ignored. The present study showed that CT and alexithymia are more common in patients with PD and impact the severity of panic symptoms. Results suggest that alexithymia may be an important mediator between CT and panic disorder severity. Copyright © 2016 Elsevier B.V. All rights reserved.

Demonstration of GTG as an endogenous initiation codon for a human mRNA transcript revealed by molecular cloning of the serpin endopin 2B.

PubMed

Hwang, Shin-Rong; Garza, Christina Z; Wegrzyn, Jill; Hook, Vivian Y H

2004-08-16

This study demonstrates utilization of the novel GTG initiation codon for translation of a human mRNA transcript that encodes the serpin endopin 2B, a protease inhibitor. Molecular cloning revealed the nucleotide sequence of the human endopin 2B cDNA. Its deduced primary sequence shows high homology to bovine endopin 2A that possesses cross-class protease inhibition of elastase and papain. Notably, the human endopin 2B cDNA sequence revealed GTG as the predicted translation initiation codon; the predicted translation product of 46 kDa endopin 2B was produced by in vitro translation of 35S-endopin 2B with mammalian (rabbit) protein translation components. Importantly, bioinformatic studies demonstrated the presence of the entire human endopin 2B cDNA sequence with GTG as initiation codon within the human genome on chromosome 14. Further evidence for GTG as a functional initiation codon was illustrated by GTG-mediated in vitro translation of the heterologous protein EGFP, and by GTG-mediated expression of EGFP in mammalian PC12 cells. Mutagenesis of GTG to GTC resulted in the absence of EGFP expression in PC12 cells, indicating the function of GTG as an initiation codon. In addition, it was apparent that the GTG initiation codon produces lower levels of translated protein compared to ATG as initiation codon. Significantly, GTG-mediated translation of endopin 2B demonstrates a functional human gene product not previously predicted from initial analyses of the human genome. Further analyses based on GTG as an alternative initiation codon may predict new candidate genes of the human genome.

Nonredundant functions of Arabidopsis LecRK-V.2 and LecRK-VII.1 in controlling stomatal immunity and jasmonate-mediated stomatal closure.

PubMed

Yekondi, Shweta; Liang, Fu-Chun; Okuma, Eiji; Radziejwoski, Amandine; Mai, Hsien-Wei; Swain, Swadhin; Singh, Prashant; Gauthier, Mathieu; Chien, Hsiao-Chiao; Murata, Yoshiyuki; Zimmerli, Laurent

2018-04-01

Stomatal immunity restricts bacterial entry to leaves through the recognition of microbe-associated molecular patterns (MAMPs) by pattern-recognition receptors (PRRs) and downstream abscisic acid and salicylic acid signaling. Through a reverse genetics approach, we characterized the function of the L-type lectin receptor kinase-V.2 (LecRK-V.2) and -VII.1 (LecRK-VII.1). Analyses of interactions with the PRR FLAGELLIN SENSING2 (FLS2) were performed by co-immunoprecipitation and bimolecular fluorescence complementation and whole-cell patch-clamp analyses were used to evaluate guard cell Ca 2+ -permeable cation channels. The Arabidopsis thaliana LecRK-V.2 and LecRK-VII.1 and notably their kinase activities were required for full activation of stomatal immunity. Knockout lecrk-V.2 and lecrk-VII.1 mutants were hyper-susceptible to Pseudomonas syringae infection and showed defective stomatal closure in response to bacteria or to the MAMPs flagellin and EF-Tu. By contrast, Arabidopsis over-expressing LecRK-V.2 or LecRK-VII.1 demonstrated a potentiated stomatal immunity. LecRK-V.2 and LecRK-VII.1 are shown to be part of the FLS2 PRR complex. In addition, LecRK-V.2 and LecRK-VII.1 were critical for methyl jasmonate (MeJA)-mediated stomatal closure, notably for MeJA-induced activation of guard cell Ca 2+ -permeable cation channels. This study highlights the role of LecRK-V.2 and LecRK-VII.1 in stomatal immunity at the FLS2 PRR complex and in MeJA-mediated stomatal closure. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Turtle Functions Downstream of Cut in Differentially Regulating Class Specific Dendrite Morphogenesis in Drosophila

PubMed Central

Sulkowski, Mikolaj J.; Iyer, Srividya Chandramouli; Kurosawa, Mathieu S.; Iyer, Eswar Prasad R.; Cox, Daniel N.

2011-01-01

Background Dendritic morphology largely determines patterns of synaptic connectivity and electrochemical properties of a neuron. Neurons display a myriad diversity of dendritic geometries which serve as a basis for functional classification. Several types of molecules have recently been identified which regulate dendrite morphology by acting at the levels of transcriptional regulation, direct interactions with the cytoskeleton and organelles, and cell surface interactions. Although there has been substantial progress in understanding the molecular mechanisms of dendrite morphogenesis, the specification of class-specific dendritic arbors remains largely unexplained. Furthermore, the presence of numerous regulators suggests that they must work in concert. However, presently, few genetic pathways regulating dendrite development have been defined. Methodology/Principal Findings The Drosophila gene turtle belongs to an evolutionarily conserved class of immunoglobulin superfamily members found in the nervous systems of diverse organisms. We demonstrate that Turtle is differentially expressed in Drosophila da neurons. Moreover, MARCM analyses reveal Turtle acts cell autonomously to exert class specific effects on dendritic growth and/or branching in da neuron subclasses. Using transgenic overexpression of different Turtle isoforms, we find context-dependent, isoform-specific effects on mediating dendritic branching in class II, III and IV da neurons. Finally, we demonstrate via chromatin immunoprecipitation, qPCR, and immunohistochemistry analyses that Turtle expression is positively regulated by the Cut homeodomain transcription factor and via genetic interaction studies that Turtle is downstream effector of Cut-mediated regulation of da neuron dendrite morphology. Conclusions/Significance Our findings reveal that Turtle proteins differentially regulate the acquisition of class-specific dendrite morphologies. In addition, we have established a transcriptional regulatory interaction between Cut and Turtle, representing a novel pathway for mediating class specific dendrite development. PMID:21811639

Mediation, identification, and plausibility: an illustration using children's mental health services.

PubMed

Foster, E Michael

2014-10-01

Analyses of mediation are important for understanding the effects of mental health services and treatments. The most common approach is to add potential mediators as regressors and to estimate the direct and indirect effects of the treatment of interest. This practice makes the strong assumption that the mediator itself does not suffer from unobserved confounding--that it is as if randomly assigned. In many instances, this assumption seems rather implausible. The objective of this article is to describe the identification problem that represents the fundamental challenge of causal inference. It outlines how mediation complicates identification and considers several identification strategies. The goal of this article is not to propose a new method for handling mediation or to identify a best method for doing so. The latter, in fact, is impossible. The contribution of the article is to illustrate how one can think about possible approaches to mediation in the context of a specific empirical study. Using data from a large evaluation of a demonstration project in children's mental health services (n = 763), the article illustrates identification strategies. That demonstration improved service delivery in several ways but primarily by offering services "intermediate" between inpatient and outpatient. These analyses focus on the impact of these intermediate services on 6-month improvement in a behavior checklist commonly used to measure psychopathology and competence among children and youths. The results highlight how different identification strategies produce different answers to key questions. These alternative findings have to be assessed in light of substantive knowledge of the program involved. The analyses generally support the notion that children and youths treated at the demonstration site who received intermediate services benefited from them. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Mediation analysis of relationships between chronic inflammation and quality of life in older adults.

PubMed

Nowakowski, Alexandra C H; Graves, Katelyn Y; Sumerau, J E

2016-03-22

This article summarizes exploratory analyses of relationships between chronic inflammation, its physical consequences, and quality of life (QoL). It summarizes key findings from preliminary analyses, and contextualizes these results with extant sociomedical literature to recommend directions for future research. Cross-sectional data from the National Social Life, Health, and Aging Project (NSHAP) were used to explore these relationships. Inflammation was assessed via the biomarker C-reactive protein (CRP). We examined associations between CRP levels and two different domains of QoL: happiness with life in general and happiness with intimate relationships. We used ordinal logistic regression with companion OLS models and Sobel-Goodman tests to assess potential mediation, and also conducted a variety of sensitivity analyses. Findings suggest that mediation pathways for the overall association between chronic inflammation and QoL may differ markedly across particular outcome constructs. Specifically, it shows mediation potential for the clinical sequelae of chronic inflammation in frameworks using happiness as an outcome measure, but not in those using relationship satisfaction. Disability appears to mediate the effect of inflammation by 27 %; chronic pain appears to exert a similar mediation effect of 21 %. Pain and disability linked to chronic inflammation appear to play a small but significant mediating role in the overall reduction in QoL observed among older adults with biomarker evidence of chronic inflammation. We note that these patterns are best framed as dynamic elements of a complex causal fabric, rather than powerful determinants that override other factors contributing to QoL. Hypotheses for further exploration using longitudinal data from the NSHAP are thus offered, pending availability of Wave III data in future years.

Transforming individual civic engagement into community collective efficacy: the role of bonding social capital.

PubMed

Collins, Charles R; Neal, Jennifer Watling; Neal, Zachary P

2014-12-01

Collective efficacy is defined as residents' perceived collective capacity to take coordinated and interdependent action on issues that affect their lives. This study explored factors associated with neighborhood collective efficacy among residents. Utilizing a national sample of 4,120 urban households provided by Annie E. Casey Foundation's Making Connection Initiative, we investigated the mediating role of residents' perceptions of bonding social capital (i.e. reciprocity, trust, and shared norms) in the association between civic engagement and collective efficacy. Multiple regression analyses revealed that civic engagement and bonding social capital were both directly related to collective efficacy. Additionally, bonding social capital partially mediated the relationship between civic engagement and collective efficacy. Specifically, residents who reported greater levels of civic engagement also reported higher levels of bonding social capital. In turn, residents who reported higher levels of bonding social capital also reported higher levels of neighborhood collective efficacy. We discuss implications of these findings for researchers and practitioners interested in associations of neighborhood collective efficacy.

Working in the sky: a diary study on work engagement among flight attendants.

PubMed

Xanthopoulou, Despoina; Bakker, Arnold B; Heuven, Ellen; Demerouti, Evangelia; Schaufeli, Wilmar B

2008-10-01

This study aims to gain insight in the motivational process of the Job Demands-Resources (JD-R) model by examining whether daily fluctuations in colleague support (i.e., a typical job resource) predict day-levels of job performance through self-efficacy and work engagement. Forty-four flight attendants filled in a questionnaire and a diary booklet before and after consecutive flights to three intercontinental destinations. Results of multilevel analyses revealed that colleague support had unique positive effects on self-efficacy and work engagement. Self-efficacy did not mediate the relationship between support and engagement, but work engagement mediated the relationship between self-efficacy and (in-role and extra-role) performance. In addition, colleague support had an indirect effect on in-role performance through work engagement. These findings shed light on the motivational process as outlined in the JD-R model, and suggest that colleague support is an important job resource for flight attendants helping them reach their work-related goals.

patterns of doctor–patient interaction in online environment.

PubMed

Zummo, Marianna Lya

2015-01-01

This paper questions the nature of the communicative event that takes place in online contexts between doctors and web-users, showing computer-mediated linguistic norms and discussing the nature of the participants’ roles. Based on an analysis of 1005 posts occurring between doctors and the users of health service websites, I analyse how doctor–patient communication is affected by the medium and how health professionals overcome issues concerning the virtual medical visit. Results suggest that (a) online medical answers offer a different service from that expected by users, as doctors cannot always fulfill patient requests, and (b) net consultations use aspects of traditional doctor–patient exchange and yet present a language and a style that are affected by the computer-mediated environment. Additionally, it seems that this new form leads to a different model of doctor–patient relationship. The findings are intended to provide new insights into web-based discourse in doctor–patient communication and to demonstrate the emergence of a new style in medical communication.

Supportive Coparenting Relationships as a Haven of Psychological Safety at the Transition to Parenthood

PubMed Central

Schoppe-Sullivan, Sarah J.; Settle, Theresa; Lee, Jin-kyung; Kamp Dush, Claire M.

2016-01-01

Guided by research on psychological safety, we used longitudinal survey data from a sample of 182 dual-earner male-female couples to examine the role of supportive coparenting in mediating relations between adult attachment orientations and parenting stress/satisfaction, and further considered whether parenting self-efficacy moderated relations between supportive coparenting and parenting stress/satisfaction. Path analyses using IBM SPSS AMOS 22 and bootstrapping techniques indicated that fathers’ (but not mothers’) perceptions of supportive coparenting at 3 months postpartum mediated the associations between their attachment anxiety in the third trimester of pregnancy and their parenting stress and satisfaction at 9 months postpartum. Additional tests of moderation revealed that mothers’ perceptions of greater supportive coparenting were associated with lower parenting stress only when their parenting self-efficacy was low, but fathers’ perceptions of greater supportive coparenting were associated with greater parenting satisfaction only when their parenting self-efficacy was high. Implications and limitations are discussed. PMID:29056880

The additive effects of depressive symptoms and polysubstance use on HIV risk among gay, bisexual, and other men who have sex with men.

PubMed

Card, Kiffer G; Lachowsky, Nathan J; Armstrong, Heather L; Cui, Zishan; Wang, Lu; Sereda, Paul; Jollimore, Jody; Patterson, Thomas L; Corneil, Trevor; Hogg, Robert S; Roth, Eric A; Moore, David M

2018-07-01

Among gay, bisexual, and other men who have sex with men (GBM), collinearity between polysubstance use and mental health concerns has obscured their combined effects on HIV risk with multivariable results often highlighting only one or the other. We used mediation and moderation analyses to examine the effects of polysubstance use and depressive symptoms on high-risk sex (i.e., condomless anal sex with serodiscordant/unknown status partner) in a sample of sexually-active GBM, aged ≥16 years, recruited in Metro Vancouver using respondent driven sampling. Hospital Anxiety and Depression Scale scores assessed mental health. Alcohol Use Disorder Identification Test scores assessed alcohol disorders. Poly-use of multiple drug types (e.g., stimulants, sedatives, opiates, hallucinogens) was assessed over the previous six months. Among 719 predominantly white (68.0%), gay-identified (80.7%) GBM, alcohol use was not associated with increased prevalence of high-risk sex. Controlling for demographic factors and partner number, an interaction between polysubstance use and depressive symptoms revealed that the combined effects were additively associated with increased odds for high-risk sex. Mediation models showed that polysubstance use partially mediated the relationship between depressive symptoms and high-risk sex. An interaction effect between polysubstance use (defined by using 3 or more substances in the past six months) and depressive symptoms (defined by HADS scores) revealed that the combination of these factors was associated with increased risk for high-risk sex - supporting a syndemic understanding of the production of HIV risk. Copyright © 2018 Elsevier Ltd. All rights reserved.

Pubertal development, spare time activities, and adolescent delinquency: testing the contextual amplification hypothesis.

PubMed

Kretschmer, Tina; Oliver, Bonamy R; Maughan, Barbara

2014-08-01

Extensive evidence supports associations between early pubertal timing and adolescent externalizing behavior, but how and under which conditions they are linked is not fully understood. In addition, pubertal development is also characterized by variations in the relative speed at which individuals mature, but studies linking pubertal 'tempo' and outcomes are scarce. This study examined the mediating and moderating roles of spare time activities in associations between pubertal development and later delinquency, using data from a large (4,327 girls, 4,250 boys) longitudinal UK cohort (Avon Longitudinal Study of Parents and Children). Self-reports of Tanner stage were available from ages 9 to 14, spare time activities at age 12 and delinquency at age 15. Pubertal development was examined using latent growth models. Spare time activities were categorized using factor analyses, yielding four types (hanging out at home, hanging out outside, consumerist behavior, and sports/games), which were examined as mediators and moderators. Earlier and faster maturation predicted delinquency in boys and girls. Spare time activities partially mediated these links such that early maturing girls more often engaged in hanging out outside, which placed them at greater risk for delinquency. In addition, compared to their later and slower maturing counterparts, boys who matured earlier and faster were less likely to engage in sports/games, a spare time activity type that is linked to lower delinquency risk. No moderation effects were found. The findings extend previous research on outcomes of early maturation and show how spare time activities act as proxies between pubertal development and delinquency.

Refractory Organics in Comet 67P Churyumov-Gerasimenko: Additional Evidence for Large-scale Mixing in the Primitive Solar Nebula?

NASA Technical Reports Server (NTRS)

Nuth, J. A.; Johnson, N. M.; Ferguson, F. T.; Hilchenbach, M.; Merouane, S.; Paquette, J. A.; Stenzel, O.; Cottin, H.; Fray, N.; Bardyn, A.;

Electrochemical analyses of redox-active iron minerals: a review of nonmediated and mediated approaches.

PubMed

Sander, Michael; Hofstetter, Thomas B; Gorski, Christopher A

2015-05-19

Redox-active minerals are ubiquitous in the environment and are involved in numerous electron transfer reactions that significantly affect biogeochemical processes and cycles as well as pollutant dynamics. As a consequence, research in different scientific disciplines is devoted to elucidating the redox properties and reactivities of minerals. This review focuses on the characterization of mineral redox properties using electrochemical approaches from an applied (bio)geochemical and environmental analytical chemistry perspective. Establishing redox equilibria between the minerals and working electrodes is a major challenge in electrochemical measurements, which we discuss in an overview of traditional electrochemical techniques. These issues can be overcome with mediated electrochemical analyses in which dissolved redox mediators are used to increase the rate of electron transfer and to facilitate redox equilibration between working electrodes and minerals in both amperometric and potentiometric measurements. Using experimental data on an iron-bearing clay mineral, we illustrate how mediated electrochemical analyses can be employed to derive important thermodynamic and kinetic data on electron transfer to and from structural iron. We summarize anticipated methodological advancements that will further contribute to advance an improved understanding of electron transfer to and from minerals in environmentally relevant redox processes.

Posttraumatic stress disorder symptoms and attitudes about social support: Does shame matter?

PubMed

Dodson, Thomas S; Beck, J Gayle

2017-04-01

Considerable research has examined the association between posttraumatic stress disorder (PTSD) symptoms and social support. One facet of this relationship that deserves greater attention concerns trauma survivors' negative expectations towards social support, termed negative network orientation. To expand our understanding of negative network orientation, the current study examined shame as a possible mediator in the relationship between PTSD symptoms and negative network orientation, in a sample of 202 female survivors of intimate partner violence (IPV). Additionally, a history of child abuse (CA) was evaluated as a moderator of the association between shame and negative network orientation in this model. Path analyses indicated a significant indirect effect between PTSD symptoms and negative network orientation through shame, indicative of mediation. A history of CA moderated this effect, such that women with a history of CA in addition to IPV showed a significantly stronger relationship between PTSD symptoms and negative network orientation through shame, relative to women who only had a history of IPV. These findings support the relevance of shame in understanding the association between PTSD symptoms and negative beliefs about social support and highlight the role of childhood abuse as a moderator in this process among IPV survivors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Does Age Moderate the Effect of Spirituality/Religiousness in Accounting for Alcoholics Anonymous Benefit?

PubMed Central

Montes, K. S.; Tonigan, J. S.

2017-01-01

Objective Gains in spiritual/religious (S/R) practices among Alcoholics Anonymous (AA) members are associated with reductions in drinking. This study had the following aims: (a) examine spirituality/religiousness as a mediator of the relationship between AA attendance and reductions in drinking behavior to replicate past research findings and to (b) examine age-cohort as a moderator of the mediational analyses given that empirical evidence (e.g., generational differences in spirituality) suggests that age may influence the acquisition of gains in spirituality/religiousness during AA as well as the expression of these gains on drinking behavior. Method Measures were administered to 253 participants recruited from community-based AA and outpatient treatment programs at baseline, 3, 6, 9, and 12-months, and 210 (83%) participants provided complete data to test study aims. Results Gains in S/R practices mediated the relationship between AA attendance and increased abstinence, but not drinking intensity. Simple slopes analyses indicated a positive association between AA attendance and gains in S/R practices among younger AA affiliates but not older AA affiliates in the moderated-mediational analyses. However, age was not found to moderate the global mediational effect. Conclusions The results from the current study inform efforts to increase positive change in AA affiliates’ drinking behavior by highlighting specific aspects of S/R practices that should be targeted based on the age of an AA affiliate. PMID:28824222

Does Age Moderate the Effect of Spirituality/Religiousness in Accounting for Alcoholics Anonymous Benefit?

PubMed

Montes, K S; Tonigan, J S

2017-01-01

Gains in spiritual/religious (S/R) practices among Alcoholics Anonymous (AA) members are associated with reductions in drinking. This study had the following aims: (a) examine spirituality/religiousness as a mediator of the relationship between AA attendance and reductions in drinking behavior to replicate past research findings and to (b) examine age-cohort as a moderator of the mediational analyses given that empirical evidence (e.g., generational differences in spirituality) suggests that age may influence the acquisition of gains in spirituality/religiousness during AA as well as the expression of these gains on drinking behavior. Measures were administered to 253 participants recruited from community-based AA and outpatient treatment programs at baseline, 3, 6, 9, and 12-months, and 210 (83%) participants provided complete data to test study aims. Gains in S/R practices mediated the relationship between AA attendance and increased abstinence, but not drinking intensity. Simple slopes analyses indicated a positive association between AA attendance and gains in S/R practices among younger AA affiliates but not older AA affiliates in the moderated-mediational analyses. However, age was not found to moderate the global mediational effect. The results from the current study inform efforts to increase positive change in AA affiliates' drinking behavior by highlighting specific aspects of S/R practices that should be targeted based on the age of an AA affiliate.

Exercise self-identity: interactions with social comparison and exercise behaviour.

PubMed

Verkooijen, Kirsten T; de Bruijn, Gert-Jan

2013-01-01

Possible interactions among exercise self-identity, social comparison and exercise behaviour were explored in a sample of 417 undergraduate students (mean age = 21.5, SD = 3.0; 73% female). Two models were examined using self-report data; (1) a mediation model which proposed an association between social comparison and exercise behaviour mediated by exercise self-identity and (2) a moderation model proposing an association between exercise behaviour and self-identity moderated by social comparison. Results of the mediation analyses revealed partial mediation of the social comparison--exercise behaviour relationship by self-identity in females. Results of the moderation analyses revealed in males a significant interaction of social comparison with exercise behaviour in the prediction of self-identity - the positive association between exercise behaviour and exercise self-identity showed only significant among male students who believed to exercise equally much or less than peers. Possible explanations and implications for exercise promotion are discussed.

Self-Esteem and Problematic Drinking in China: A Mediated Model.

PubMed

Zhai, Hui; Yang, Yanjie; Sui, Hong; Wang, Wenbo; Chen, Lu; Qiu, Xiaohui; Yang, Xiuxian; Qiao, Zhengxue; Wang, Lin; Zhu, Xiongzhao; Yang, Jiarun

2015-01-01

Although self-esteem is related to problematic drinking, the mechanisms by which it affects drinking remain unclear. The purpose of this study was to determine whether coping mechanisms mediate the relationship between self-esteem and problematic drinking among Chinese men and women with alcohol use disorders and to recommend appropriate interventions for drinking problems. A cross-sectional survey was conducted in Harbin, Heilongjiang Province, China. A sample of 5,689 community residents was screened, and 517 male and 172 female problematic drinkers were chosen to participate in this study. A self-esteem scale, a coping questionnaire and an alcohol use disorder identification test were completed in order to assess participants' self-esteem, coping mechanisms and alcohol use disorders, respectively. Participants' socio-demographic data were also gathered at this stage. The resulting data were examined via descriptive statistics, correlations and bootstrap analyses. Lower self-esteem levels were related to problematic drinking, and there were no gender differences in the relationship between self-esteem and problematic drinking. A relationship between low self-esteem and negative coping was observed only in men. Negative coping thus mediated the relationship between self-esteem and problematic drinking among men, but this was not the case for women. Positive coping did not mediate the relationship between self-esteem and problematic drinking among the participants, regardless of gender. Self-esteem and coping strategies are correlated among problematic drinkers. In addition, there are gender differences in the manners in which negative coping mediates the relationship between self-esteem and problematic drinking. Problematic drinking interventions directed at males should simultaneously address low self-esteem and negative coping.

Job attitudes and well-being among public vs. private physicians: organizational justice and job control as mediators.

PubMed

Heponiemi, Tarja; Kuusio, Hannamaria; Sinervo, Timo; Elovainio, Marko

2011-08-01

The present study examined whether there are differences in job-related attitudes and well-being among physicians working in private sector and public sector. In addition, we examined whether psychosocial factors (organizational justice and job control) could mediate these possible differences in different sectors. Cross-sectional survey data from the Finnish Health Professional Study was used. A random sample of Finnish physicians included 1522 women and 1047 men aged 25-65 years. Outcome variables were job satisfaction, organizational commitment, psychological distress, work ability and sleeping problems. Job control and organizational justice were measured using established questionnaires. Series of regression analyses were performed and the mediational effects were tested following the procedures outlined by Baron and Kenny. Physicians working in private sector had higher levels of job satisfaction and organizational commitment and lower levels of psychological distress and sleeping problems when compared with physicians working in public sector. Private physicians also had higher levels of organizational justice, which acted as a mediator behind more positive attitudes and better well-being in private sector. Private physicians had higher levels of job control but it did not act as a mediator. Private physicians feel better than public physicians and this is partly due to higher organizational justice in private sector. Public health care organizations should invest effort to increase the fairness in their organizations and management and pay more attention in improving the well-being of their employees, which could possibly increase the attractiveness of public sector as a career option.

Proteomic analysis of the signaling pathway mediated by the heterotrimeric Gα protein Pga1 of Penicillium chrysogenum.

PubMed

Carrasco-Navarro, Ulises; Vera-Estrella, Rosario; Barkla, Bronwyn J; Zúñiga-León, Eduardo; Reyes-Vivas, Horacio; Fernández, Francisco J; Fierro, Francisco

2016-10-06

The heterotrimeric Gα protein Pga1-mediated signaling pathway regulates the entire developmental program in Penicillium chrysogenum, from spore germination to the formation of conidia. In addition it participates in the regulation of penicillin biosynthesis. We aimed to advance the understanding of this key signaling pathway using a proteomics approach, a powerful tool to identify effectors participating in signal transduction pathways. Penicillium chrysogenum mutants with different levels of activity of the Pga1-mediated signaling pathway were used to perform comparative proteomic analyses by 2D-DIGE and LC-MS/MS. Thirty proteins were identified which showed differences in abundance dependent on Pga1 activity level. By modifying the intracellular levels of cAMP we could establish cAMP-dependent and cAMP-independent pathways in Pga1-mediated signaling. Pga1 was shown to regulate abundance of enzymes in primary metabolic pathways involved in ATP, NADPH and cysteine biosynthesis, compounds that are needed for high levels of penicillin production. An in vivo phosphorylated protein containing a pleckstrin homology domain was identified; this protein is a candidate for signal transduction activity. Proteins with possible roles in purine metabolism, protein folding, stress response and morphogenesis were also identified whose abundance was regulated by Pga1 signaling. Thirty proteins whose abundance was regulated by the Pga1-mediated signaling pathway were identified. These proteins are involved in primary metabolism, stress response, development and signal transduction. A model describing the pathways through which Pga1 signaling regulates different cellular processes is proposed.

Association Between Internalized HIV-Related Stigma and HIV Care Visit Adherence.

PubMed

Rice, Whitney S; Crockett, Kaylee B; Mugavero, Michael J; Raper, James L; Atkins, Ghislaine C; Turan, Bulent

2017-12-15

Internalized HIV-related stigma acts as a barrier to antiretroviral therapy (ART) adherence, but its effects on other HIV care continuum outcomes are unclear. Among 196 HIV clinic patients in Birmingham, AL, we assessed internalized HIV-related stigma and depressive symptom severity using validated multi-item scales and assessed ART adherence using a validated single-item measure. HIV visit adherence (attended out of total scheduled visits) was calculated using data from clinic records. Using covariate-adjusted regression analysis, we investigated the association between internalized stigma and visit adherence. Using path analytic methods with bootstrapping, we tested the mediating role of depressive symptoms in the association between internalized stigma and visit adherence and the mediating role of visit adherence in the association between internalized stigma and ART adherence. Higher internalized stigma was associated with lower visit adherence (B = -0.04, P = 0.04). Black (versus white) race and depressive symptoms were other significant predictors within this model. Mediation analysis yielded no indirect effect through depression in the association between internalized stigma and visit adherence (B = -0.18, SE = 0.11, 95% confidence interval: -0.44 to -0.02) in the whole sample. Supplemental mediated moderation analyses revealed gender-specific effects. Additionally, the effect of internalized stigma on suboptimal ART adherence was mediated by lower visit adherence (B = -0.18, SE = 0.11, 95% confidence interval: -0.44 to -0.02). Results highlight the importance of internalized HIV stigma to multiple and sequential HIV care continuum outcomes. Also, findings suggest multiple intervention targets, including addressing internalized stigma directly, reducing depressive symptoms, and promoting consistent engagement in care.

Passion, Trait Self-Control, and Wellbeing: Comparing Two Mediation Models Predicting Wellbeing.

PubMed

Briki, Walid

2017-01-01

Research has found that passion and trait self-control represented key determinants of wellbeing. Yet, no study to date has attempted to investigate the mediating influences of trait self-control and passion for accounting for the relationships between passion, trait self-control, and wellbeing (dependent variable). Using different frameworks, such as the dualistic model of passion and the neo-socioanalytic theory, the present study proposed two mediation models, considering either trait self-control (model 1) or passion (model 2) as the mediating variable. Five hundred nine volunteers from the United States (326 females and 183 males; M age = 31.74, SD age = 11.05, from 18 to 70 years old), who reported being passionate about a specific activity (e.g., fishing, swimming, blogging; M passion = 5.94, SD passion = 0.89), answered questionnaires assessing harmonious and obsessive passion, trait self-control, and wellbeing (measured through hedonic and eudaimonic wellbeing scales). Preliminary analyses revealed that both models were significant ( model 1: absolute GoF = 0.366, relative GoF = 0.971, outer model GoF = 0.997, inner model GoF = 0.973, R 2 = 18.300%, p < 0.001; model 2: absolute GoF = 0.298; relative GoF = 0.980; outer model GoF = 0.997; inner model GoF = 0.982; R 2 = 12.111%, p < 0.001). Correlational analyses revealed positive relationships between harmonious passion, trait self-control, and wellbeing, and no relationships of obsessive passion with trait self-control and wellbeing. Mediation analyses revealed that trait self-control significantly mediated the relationship between harmonious passion and wellbeing (i.e., partial mediation, VAF = 33.136%). Harmonious passion appeared to significantly mediate the positive effect of trait self-control on wellbeing; however, the size of the mediating effect indicated that (almost) no mediation would take place (i.e., VAF = 11.144%). The present study is the first to examine the relationships between passion, trait self-control, and wellbeing, and supports the view that trait self-control and harmonious passion represent not only adaptive and powerful constructs, but also key determinants of wellbeing. Implications for the study of passion, trait self-control and wellbeing are discussed.

Passion, Trait Self-Control, and Wellbeing: Comparing Two Mediation Models Predicting Wellbeing

PubMed Central

Briki, Walid

2017-01-01

Research has found that passion and trait self-control represented key determinants of wellbeing. Yet, no study to date has attempted to investigate the mediating influences of trait self-control and passion for accounting for the relationships between passion, trait self-control, and wellbeing (dependent variable). Using different frameworks, such as the dualistic model of passion and the neo-socioanalytic theory, the present study proposed two mediation models, considering either trait self-control (model 1) or passion (model 2) as the mediating variable. Five hundred nine volunteers from the United States (326 females and 183 males; Mage = 31.74, SDage = 11.05, from 18 to 70 years old), who reported being passionate about a specific activity (e.g., fishing, swimming, blogging; Mpassion = 5.94, SDpassion = 0.89), answered questionnaires assessing harmonious and obsessive passion, trait self-control, and wellbeing (measured through hedonic and eudaimonic wellbeing scales). Preliminary analyses revealed that both models were significant (model 1: absolute GoF = 0.366, relative GoF = 0.971, outer model GoF = 0.997, inner model GoF = 0.973, R2 = 18.300%, p < 0.001; model 2: absolute GoF = 0.298; relative GoF = 0.980; outer model GoF = 0.997; inner model GoF = 0.982; R2 = 12.111%, p < 0.001). Correlational analyses revealed positive relationships between harmonious passion, trait self-control, and wellbeing, and no relationships of obsessive passion with trait self-control and wellbeing. Mediation analyses revealed that trait self-control significantly mediated the relationship between harmonious passion and wellbeing (i.e., partial mediation, VAF = 33.136%). Harmonious passion appeared to significantly mediate the positive effect of trait self-control on wellbeing; however, the size of the mediating effect indicated that (almost) no mediation would take place (i.e., VAF = 11.144%). The present study is the first to examine the relationships between passion, trait self-control, and wellbeing, and supports the view that trait self-control and harmonious passion represent not only adaptive and powerful constructs, but also key determinants of wellbeing. Implications for the study of passion, trait self-control and wellbeing are discussed. PMID:28611704

Modifying interpretation biases in body dysmorphic disorder: Evaluation of a brief computerized treatment.

PubMed

Summers, Berta J; Cougle, Jesse R

2016-12-01

Individuals meeting diagnostic criteria for body dysmorphic disorder (BDD; N = 40) were enrolled in a randomized, four-session trial comparing interpretation bias modification (IBM) training designed to target social evaluation- and appearance-related interpretation biases with a placebo control training condition (PC). Sessions took place over the course of two weeks (two sessions per week). Analyses indicated that, relative to the PC condition, IBM led to a significant increase in benign biases and reduction in threat biases at post-treatment. IBM also led to greater reductions in BDD symptoms compared to PC, though this effect was present at high but not low levels of pre-treatment BDD symptoms. Additionally, compared to PC, IBM led to lower urge to check and lower fear in response to an in vivo appearance-related stressor (having their picture taken from different angles), though the latter effect was present only among those reporting elevated fear at pre-treatment. The effects of treatment on interpretation biases and BDD symptoms were largely maintained at a one-month follow-up assessment. Moderated-mediation analyses showed that change in threat bias mediated the effect of condition on post-treatment symptoms for individuals high in pre-treatment BDD symptoms. The current study provides preliminary support for the efficacy of IBM for BDD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Longitudinal Trajectories of Parental Involvement in Type 1 Diabetes and Adolescents’ Adherence

PubMed Central

King, Pamela S.; Berg, Cynthia A.; Butner, Jonathan; Butler, Jorie M.; Wiebe, Deborah J.

2016-01-01

Objective The purpose of this study was to examine longitudinal trajectories of parental involvement and adolescent adherence to the Type 1 diabetes regimen, to determine whether changes in multiple facets of parental involvement over time predicted subsequent changes in adolescents’ adherence, and to examine whether adolescent self-efficacy mediated the effect of parental involvement on adherence. Method Two hundred fifty-two adolescents (M age = 12.49 years, SD = 1.53; 53.6% females) diagnosed with Type 1 diabetes mellitus, their mothers, and 188 fathers were enrolled in a 2.5-year longitudinal study. Across 5 time points, up to 252 adolescents and their parents completed measures of adherence, parental involvement (diabetes monitoring, behavioral involvement in diabetes management, and acceptance), and adolescent diabetes self-efficacy. Results Using multilevel modeling, analyses indicated significant average declines over time in adherence and most indicators of parental involvement. Lagged multilevel models indicated that declines in mothers’ and fathers’ acceptance and diabetes monitoring predicted subsequent declines in adolescents’ adherence. Additional analyses revealed that longitudinal associations between both maternal acceptance and diabetes monitoring and subsequent adolescent adherence were mediated by adolescents’ self-efficacy. Conclusions Results of this study, which were largely consistent across reporters, highlight the importance of maintaining parental involvement in diabetes across adolescence and suggest that parental involvement is beneficial for adolescents’ adherence, in part, because it contributes to higher self-efficacy for diabetes management among adolescents. PMID:23795709

Contribution of the Cholinergic System to Verbal Memory Performance in Mild Cognitive Impairment.

PubMed

Peter, Jessica; Lahr, Jacob; Minkova, Lora; Lauer, Eliza; Grothe, Michel J; Teipel, Stefan; Köstering, Lena; Kaller, Christoph P; Heimbach, Bernhard; Hüll, Michael; Normann, Claus; Nissen, Christoph; Reis, Janine; Klöppel, Stefan

2016-06-18

Acetylcholine is critically involved in modulating learning and memory function, which both decline in neurodegeneration. It remains unclear to what extent structural and functional changes in the cholinergic system contribute to episodic memory dysfunction in mild cognitive impairment (MCI), in addition to hippocampal degeneration. A better understanding is critical, given that the cholinergic system is the main target of current symptomatic treatment in mild to moderate Alzheimer's disease. We simultaneously assessed the structural and functional integrity of the cholinergic system in 20 patients with MCI and 20 matched healthy controls and examined their effect on verbal episodic memory via multivariate regression analyses. Mediating effects of either cholinergic function or hippocampal volume on the relationship between cholinergic structure and episodic memory were computed. In MCI, a less intact structure and function of the cholinergic system was found. A smaller cholinergic structure was significantly correlated with a functionally more active cholinergic system in patients, but not in controls. This association was not modulated by age or disease severity, arguing against compensational processes. Further analyses indicated that neither functional nor structural changes in the cholinergic system influence verbal episodic memory at the MCI stage. In fact, those associations were fully mediated by hippocampal volume. Although the cholinergic system is structurally and functionally altered in MCI, episodic memory dysfunction results primarily from hippocampal neurodegeneration, which may explain the inefficiency of cholinergic treatment at this disease stage.

Associations of indoor carbon dioxide concentrations and environmental susceptibilities with mucous membrane and lower respiratory building related symptoms in the BASE study: Analyses of the 100 building dataset

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erdmann, Christine A.; Apte, Michael G.

Using the US EPA 100 office-building BASE Study dataset, they conducted multivariate logistic regression analyses to quantify the relationship between indoor CO{sub 2} concentrations (dCO{sub 2}) and mucous membrane (MM) and lower respiratory system (LResp) building related symptoms, adjusting for age, sex, smoking status, presence of carpet in workspace, thermal exposure, relative humidity, and a marker for entrained automobile exhaust. In addition, they tested the hypothesis that certain environmentally-mediated health conditions (e.g., allergies and asthma) confer increased susceptibility to building related symptoms within office buildings. Adjusted odds ratios (ORs) for statistically significant, dose-dependent associations (p < 0.05) for dry eyes,more » sore throat, nose/sinus congestion, and wheeze symptoms with 100 ppm increases in dCO{sub 2} ranged from 1.1 to 1.2. These results suggest that increases in the ventilation rates per person among typical office buildings will, on average, reduce the prevalence of several building related symptoms by up to 70%, even when these buildings meet the existing ASHRAE ventilation standards for office buildings. Building occupants with certain environmentally-mediated health conditions are more likely to experience building related symptoms than those without these conditions (statistically significant ORs ranged from 2 to 11).« less

Subjective Age and Changes in Memory in Older Adults.

PubMed

Stephan, Yannick; Sutin, Angelina R; Caudroit, Johan; Terracciano, Antonio

2016-07-01

The subjective experience of aging, indexed by how old or young an individual feels, has been related to well-being and health-related outcomes among older adults. The present study examined whether subjective age is associated with memory level and changes, as indexed by measures of immediate and delayed recall. A complementary purpose was to test the mediating role of depressive symptoms and physical activity in the relation between subjective age and memory changes. Participants were drawn from three waves of the Health and Retirement Study. Subjective age, baseline memory measures, and covariates were assessed during the 2008 wave (N = 5809), depressive symptoms and physical activity were assessed again in the 2010 wave, and the follow-up memory measures were assessed in the 2012 wave. Regression analyses that included demographic, metabolic, and vascular covariates revealed that a younger subjective age at baseline was associated with better concurrent performance and with slower decline in immediate and delayed recall. Bootstrap procedures indicated that fewer depressive symptoms mediated these associations. Additional analyses revealed that memory level and change were unrelated to changes in subjective age. Beyond chronological age, the subjective experience of age is associated with cognitive aging. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeremy Semrau; Sung-Woo Lee; Jeongdae Im

2010-09-30

The overall objective of this project, 'Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils' was to develop effective, efficient, and economic methodologies by which microbial production of nitrous oxide can be minimized while also maximizing microbial consumption of methane in landfill cover soils. A combination of laboratory and field site experiments found that the addition of nitrogen and phenylacetylene stimulated in situ methane oxidation while minimizing nitrous oxide production. Molecular analyses also indicated that methane-oxidizing bacteria may play a significant role in not only removing methane, but in nitrous oxide production as well, although themore » contribution of ammonia-oxidizing archaea to nitrous oxide production can not be excluded at this time. Future efforts to control both methane and nitrous oxide emissions from landfills as well as from other environments (e.g., agricultural soils) should consider these issues. Finally, a methanotrophic biofiltration system was designed and modeled for the promotion of methanotrophic activity in local methane 'hotspots' such as landfills. Model results as well as economic analyses of these biofilters indicate that the use of methanotrophic biofilters for controlling methane emissions is technically feasible, and provided either the costs of biofilter construction and operation are reduced or the value of CO{sub 2} credits is increased, can also be economically attractive.« less

Mindfulness Mechanisms in Sports: Mediating Effects of Rumination and Emotion Regulation on Sport-Specific Coping.

PubMed

Josefsson, Torbjörn; Ivarsson, Andreas; Lindwall, Magnus; Gustafsson, Henrik; Stenling, Andreas; Böröy, Jan; Mattsson, Emil; Carnebratt, Jakob; Sevholt, Simon; Falkevik, Emil

2017-01-01

The main objective of the project was to examine a proposed theoretical model of mindfulness mechanisms in sports. We conducted two studies (the first study using a cross-sectional design and the second a longitudinal design) to investigate if rumination and emotion regulation mediate the relation between dispositional mindfulness and sport-specific coping. Two hundred and forty-two young elite athletes, drawn from various sports, were recruited for the cross-sectional study. For the longitudinal study, 65 elite athletes were recruited. All analyses were performed using Bayesian statistics. The path analyses showed credible indirect effects of dispositional mindfulness on coping via rumination and emotion regulation in both the cross-sectional study and the longitudinal study. Additionally, the results in both studies showed credible direct effects of dispositional mindfulness on rumination and emotion regulation. Further, credible direct effects of emotion regulation as well as rumination on coping were also found in both studies. Our findings support the theoretical model, indicating that rumination and emotion regulation function as essential mechanisms in the relation between dispositional mindfulness and sport-specific coping skills. Increased dispositional mindfulness in competitive athletes (i.e. by practicing mindfulness) may lead to reductions in rumination, as well as an improved capacity to regulate negative emotions. By doing so, athletes may improve their sport-related coping skills, and thereby enhance athletic performance.

The effect of computer-mediated administration on self-disclosure of problems on the addiction severity index.

PubMed

Butler, Stephen F; Villapiano, Albert; Malinow, Andrew

2009-12-01

People tend to disclose more personal information when communication is mediated through the use of a computer. This study was conducted to examine the impact of this phenomenon on the way respondents answer questions during computer-mediated, self-administration of the Addiction Severity Index (ASI) called the Addiction Severity Index-Multimedia Version((R)) (ASI-MV((R))). A sample of 142 clients in substance abuse treatment was administered the ASI via an interviewer and the computerized ASI-MV((R)), three to five days apart in a counterbalanced order. Seven composite scores were compared between the two test administrations using paired t-tests. Post hoc analyses examined interviewer effects. Comparisons of composite scores for each of the domains between the face-to-face administered and computer-mediated, self-administered ASI revealed that significantly greater problem severity was reported by clients in five of the seven domains during administration of the computer-mediated, self-administered version compared to the trained interviewer version. Item analyses identified certain items as responsible for significant differences, especially those asking clients to rate need for treatment. All items that were significantly different between the two modes of administration revealed greater problem severity reported on the ASI-MV((R)) as compared to the interview administered assessment. Post hoc analyses yielded significant interviewer effects on four of the five domains where differences were observed. These data support a growing literature documenting a tendency for respondents to be more self-disclosing in a computer-mediated format over a face-to-face interview. Differences in interviewer skill in establishing rapport may account for these observations.

Physical Activity and Bone Health in Schoolchildren: The Mediating Role of Fitness and Body Fat

PubMed Central

Torres-Costoso, Ana; Gracia-Marco, Luis; Sánchez-López, Mairena; Notario-Pacheco, Blanca; Arias-Palencia, Natalia; Martínez-Vizcaíno, Vicente

2015-01-01

Background The relationship between physical activity (PA) and bone health is well known, although the role of percent body fat (%BF) and fitness as confounders or mediators in this relationship remains uncertain. Objective To examine whether the association between PA and bone mineral content (BMC) is mediated by %BF and cardiorespiratory fitness (CRF). Methods In this cross sectional study, BMC, total %BF (by DXA), vigorous PA (VPA), CRF, age and height were measured in 132 schoolchildren (62 boys, aged 8–11 years). ANCOVA was used to test differences in BMC by %BF, CRF and VPA, controlling for different sets of confounders. Simple mediation analyses and serial multiple mediation analyses were fitted to examine whether the relationship between PA and BMC is mediated by %BF and fitness. Results Children with high %BF had higher total body BMC than their peers after controlling for all sets of confounders. Children with good CRF or VPA had significantly less total body BMC after controlling for age and sex but in children with good CRF this inverse relation disappeared after adjusting by %BF. %BF and CRF both act as a full mediator in the association between VPA and BMC, after inclusion of the potential confounders in the models. Conclusion Fitness and %BF seem to have a mediator role on the relationship between physical activity and bone mass. PMID:25915941

Effects of multiple enzyme-substrate interactions in basic units of cellular signal processing

NASA Astrophysics Data System (ADS)

Seaton, D. D.; Krishnan, J.

2012-08-01

Covalent modification cycles are a ubiquitous feature of cellular signalling networks. In these systems, the interaction of an active enzyme with the unmodified form of its substrate is essential for signalling to occur. However, this interaction is not necessarily the only enzyme-substrate interaction possible. In this paper, we analyse the behaviour of a basic model of signalling in which additional, non-essential enzyme-substrate interactions are possible. These interactions include those between the inactive form of an enzyme and its substrate, and between the active form of an enzyme and its product. We find that these additional interactions can result in increased sensitivity and biphasic responses, respectively. The dynamics of the responses are also significantly altered by the presence of additional interactions. Finally, we evaluate the consequences of these interactions in two variations of our basic model, involving double modification of substrate and scaffold-mediated signalling, respectively. We conclude that the molecular details of protein-protein interactions are important in determining the signalling properties of enzymatic signalling pathways.

Mediating Effects of Social Support on Quality of Life for Parents of Adults with Autism

ERIC Educational Resources Information Center

Marsack, Christina N.; Samuel, Preethy S.

2017-01-01

The aim of this study was to examine the mediating effect of formal and informal social support on the relationship of caregiver burden and quality of life (QOL), using a sample of 320 parents (aged 50 or older) of adult children with autism spectrum disorder (ASD). Multiple linear regression and mediation analyses indicated that caregiver burden…

Burnout and health among critical care professionals: The mediational role of resilience.

PubMed

Arrogante, Oscar; Aparicio-Zaldivar, Eva

2017-10-01

To analyse the mediational role of resilience in relationships between burnout and health in critical care professionals; to determine relationships among resilience level, three burnout dimensions, and physical/mental health; and to establish demographic differences in psychological variables evaluated. Cross-sectional study. A total of 52 critical care professionals, mainly nurses, were recruited from an intensive care unit of Madrid (Spain). All participants were assessed with the questionnaires 10-item Connor-Davidson Resilience Scale, Maslach Burnout Inventory-Human Services Survey, and Short Form-12 Health Survey. No demographic differences were found. Three burnout dimensions were negatively associated with mental health and resilience. Mediational analyses revealed resilience mediated 1) the relationships between emotional exhaustion and depersonalisation with mental health (partial mediations) and 2) the relationship between personal accomplishment and mental health (total mediation). Resilience minimises and buffers the impact of negative outcomes of workplace stress on mental health of critical care professionals. As a result, resilience prevents the occurrence of burnout syndrome. Resilience improves not only their mental health, but also their ability to practice effectively. It is therefore imperative to develop resilience programs for critical care nurses in nursing schools, universities and health centres. Copyright © 2017 Elsevier Ltd. All rights reserved.

Workplace ostracism And workplace behaviors: A moderated mediation model of perceived stress and psychological empowerment.

PubMed

Chung, Yang Woon

2018-05-01

Workplace ostracism research has examined numerous underlying mechanisms to understand the link between workplace ostracism and behavioral outcomes. Ostracism has been suggested to be an interpersonal stressor; however, research has not investigated workplace ostracism from a stress perspective. Therefore, the study investigated the mediating effect of perceived stress for the relationships between workplace ostracism and helping behavior, voicing behavior, and task performance. The study also investigated the moderating effect of psychological empowerment for the relationships between perceived stress and behavioral outcomes. The study design was a three-wave self-reported questionnaire. The study sampled 225 full-time employees in South Korea and regression analyses with bootstrapping were conducted to test the moderated mediation models. The bootstrapped 95% CI around the indirect effects did not contain zero; therefore, perceived stress mediated the relationship between workplace ostracism and helping behavior (-.06), voicing behavior (-.07), and task performance (-.07). Further, the moderated mediation analyses found perceived stress mediated the relationships between workplace ostracism and behavioral outcomes only when individuals perceived low levels of psychological empowerment. The findings suggest that workplace ostracism is a stressor and psychological empowerment can mitigate the negative effects of ostracism on behavioral outcomes.

Why do boys eat less fruit and vegetables than girls?

PubMed

Bere, Elling; Brug, Johannes; Klepp, Knut-Inge

2008-03-01

To explore why boys eat less fruit and vegetables (F&V) than girls, using longitudinal data following pupils from the age of 12.5 to 15.5 years, including perceived accessibility, modelling, intention, preferences, self-efficacy and knowledge of recommendations as potential mediators. A longitudinal study, based on data collected among the control schools within the intervention project 'Fruits and Vegetables Make the Marks'. This sample contains 896 6th and 7th graders from 20 randomly selected elementary schools within two Norwegian counties. Questionnaires were administered in May 2002 and May 2005 (when the participants were in 9th and 10th grade in 18 secondary elementary schools). In single mediation analyses all determinants mediated parts of the gender difference, but only preferences decreased the gender difference to a level below statistical significance. Preferences alone explained 81% of the gender difference. In the multiple mediation analyses, the six mediators together explained 91% of the gender difference, but only preferences and perceived accessibility contributed uniquely to the explanation, with 25% and 10% respectively. Preference appears as the strongest mediator of the difference in F&V intakes between boys and girls. Further research should explore why girls like F&V more than boys.

Identification of miRNAs and Their Targets in the Liverwort Marchantia polymorpha by Integrating RNA-Seq and Degradome Analyses

PubMed Central

Lin, Pin-Chun; Lu, Chia-Wei; Shen, Bing-Nan; Lee, Guan-Zong; Bowman, John L.; Arteaga-Vazquez, Mario A.; Liu, Li-Yu Daisy; Hong, Syuan-Fei; Lo, Chu-Fang; Su, Gong-Min; Kohchi, Takayuki; Ishizaki, Kimitsune; Zachgo, Sabine; Althoff, Felix; Takenaka, Mizuki; Yamato, Katsuyuki T.; Lin, Shih-Shun

2016-01-01

Bryophytes (liverworts, hornworts and mosses) comprise the three earliest diverging lineages of land plants (embryophytes). Marchantia polymorpha, a complex thalloid Marchantiopsida liverwort that has been developed into a model genetic system, occupies a key phylogenetic position. Therefore, M. polymorpha is useful in studies aiming to elucidate the evolution of gene regulation mechanisms in plants. In this study, we used computational, transcriptomic, small RNA and degradome analyses to characterize microRNA (miRNA)-mediated pathways of gene regulation in M. polymorpha. The data have been integrated into the open access ContigViews-miRNA platform for further reference. In addition to core components of the miRNA pathway, 129 unique miRNA sequences, 11 of which could be classified into seven miRNA families that are conserved in embryophytes (miR166a, miR390, miR529c, miR171-3p, miR408a, miR160 and miR319a), were identified. A combination of computational and degradome analyses allowed us to identify and experimentally validate 249 targets. In some cases, the target genes are orthologous to those of other embryophytes, but in other cases, the conserved miRNAs target either paralogs or members of different gene families. In addition, the newly discovered Mpo-miR11707.1 and Mpo-miR11707.2 are generated from a common precursor and target MpARGONAUTE1 (LW1759). Two other newly discovered miRNAs, Mpo-miR11687.1 and Mpo-miR11681.1, target the MADS-box transcription factors MpMADS1 and MpMADS2, respectively. Interestingly, one of the pentatricopeptide repeat (PPR) gene family members, MpPPR_66 (LW9825), the protein products of which are generally involved in various steps of RNA metabolism, has a long stem–loop transcript that can generate Mpo-miR11692.1 to autoregulate MpPPR_66 (LW9825) mRNA. This study provides a foundation for further investigations of the RNA-mediated silencing mechanism in M. polymorpha as well as of the evolution of this gene silencing pathway in embryophytes. PMID:26861787

Internalized weight bias mediates the relationship between depressive symptoms and disordered eating behavior among women who think they are overweight.

PubMed

Sienko, Rachel M; Saules, Karen K; Carr, Meagan M

2016-08-01

This study tested the potential mediating role of Internalized Weight Bias (IWB) in the relationship between depressive symptoms (DEP-SX) and disordered eating behavior. In particular, we hypothesized that IWB may be an intervening variable in the well documented association between depression and disordered eating. College women (N=172) who were taking undergraduate psychology courses and who endorsed thinking they were overweight completed the Patient Health Questionnaire depression screener (PHQ-9), the Weight Bias Internalization Scale (WBIS), and the Eating Disorder Examination Questionnaire (EDE-Q). Bootstrapping mediation analyses were conducted to explore the relationships between these variables. IWB was significantly correlated with eating disorder symptoms and DEP-SX, but not Body Mass Index. Mediation analyses supported a model in which IWB mediated the relationship between DEP-SX and disordered eating behavior. Results indicate that individuals with elevated DEP-SX may be likely to internalize weight bias, which may in turn lead to maladaptive approaches to eating and weight control, regardless of one's actual weight status. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mediation Analysis of the Efficacy of the Eban HIV/STD Risk-Reduction Intervention for African American HIV Serodiscordant Couples.

PubMed

El-Bassel, Nabila; Jemmott, John B; Bellamy, Scarlett L; Pequegnat, Willo; Wingood, Gina M; Wyatt, Gail E; Landis, J Richard; Remien, Robert H

2016-06-01

Targeting couples is a promising behavioral HIV risk-reduction strategy, but the mechanisms underlying the effects of such interventions are unknown. We report secondary analyses testing whether Social-Cognitive-Theory variables mediated the Eban HIV-risk-reduction intervention's effects on condom-use outcomes. In a multisite randomized controlled trial conducted in four US cities, 535 African American HIV-serodiscordant couples were randomized to the Eban HIV risk-reduction intervention or attention-matched control intervention. Outcomes were proportion condom-protected sex, consistent condom use, and frequency of unprotected sex measured pre-, immediately post-, and 6 and 12 months post-intervention. Potential mediators included Social-Cognitive-Theory variables: outcome expectancies and self-efficacy. Mediation analyses using the product-of-coefficients approach in a generalized-estimating-equations framework revealed that condom-use outcome expectancy, partner-reaction outcome expectancy, intention, self-efficacy, and safer-sex communication improved post-intervention and mediated intervention-induced improvements in condom-use outcomes. These findings underscore the importance of targeting outcome expectancies, self-efficacy, and safer-sex communication in couples-level HIV risk-reduction interventions.

Parental education associations with children's body composition: mediation effects of energy balance-related behaviors within the ENERGY-project.

PubMed

Fernández-Alvira, Juan M; te Velde, Saskia J; De Bourdeaudhuij, Ilse; Bere, Elling; Manios, Yannis; Kovacs, Eva; Jan, Natasa; Brug, Johannes; Moreno, Luis A

2013-06-21

It is well known that the prevalence of overweight and obesity is considerably higher among youth from lower socio-economic families, but there is little information about the role of some energy balance-related behaviors in the association between socio-economic status and childhood overweight and obesity. The objective of this paper was to assess the possible mediation role of energy balance-related behaviors in the association between parental education and children's body composition. Data were obtained from the cross sectional study of the "EuropeaN Energy balance Research to prevent excessive weight Gain among Youth" (ENERGY) project. 2121 boys and 2516 girls aged 10 to 12 from Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia and Spain were included in the analyses. Data were obtained via questionnaires assessing obesity related dietary, physical activity and sedentary behaviors and basic anthropometric objectively measured indicators (weight, height, waist circumference). The possible mediating effect of sugared drinks intake, breakfast consumption, active transportation to school, sports participation, TV viewing, computer use and sleep duration in the association between parental education and children's body composition was explored via MacKinnon's product-of-coefficients test in single and multiple mediation models. Two different body composition indicators were included in the models, namely Body Mass Index and waist circumference. The association between parental education and children's body composition was partially mediated by breakfast consumption, sports participation, TV viewing and computer use. Additionally, a suppression effect was found for sugared drinks intake. No mediation effect was found for active transportation and sleep duration. The significant mediators explained a higher proportion of the association between parental education and waist circumference compared to the association between parental education and BMI. Tailored overweight and obesity prevention strategies in low SES preadolescent populations should incorporate specific messages focusing on the importance of encouraging daily breakfast consumption, increasing sports participation and decreasing TV viewing and computer use. However, longitudinal research to support these findings is needed.

Identifying cis-mediators for trans-eQTLs across many human tissues using genomic mediation analysis.

PubMed

Yang, Fan; Wang, Jiebiao; Pierce, Brandon L; Chen, Lin S

2017-11-01

The impact of inherited genetic variation on gene expression in humans is well-established. The majority of known expression quantitative trait loci (eQTLs) impact expression of local genes ( cis -eQTLs). More research is needed to identify effects of genetic variation on distant genes ( trans -eQTLs) and understand their biological mechanisms. One common trans -eQTLs mechanism is "mediation" by a local ( cis ) transcript. Thus, mediation analysis can be applied to genome-wide SNP and expression data in order to identify transcripts that are " cis -mediators" of trans -eQTLs, including those " cis -hubs" involved in regulation of many trans -genes. Identifying such mediators helps us understand regulatory networks and suggests biological mechanisms underlying trans -eQTLs, both of which are relevant for understanding susceptibility to complex diseases. The multitissue expression data from the Genotype-Tissue Expression (GTEx) program provides a unique opportunity to study cis -mediation across human tissue types. However, the presence of complex hidden confounding effects in biological systems can make mediation analyses challenging and prone to confounding bias, particularly when conducted among diverse samples. To address this problem, we propose a new method: Genomic Mediation analysis with Adaptive Confounding adjustment (GMAC). It enables the search of a very large pool of variables, and adaptively selects potential confounding variables for each mediation test. Analyses of simulated data and GTEx data demonstrate that the adaptive selection of confounders by GMAC improves the power and precision of mediation analysis. Application of GMAC to GTEx data provides new insights into the observed patterns of cis -hubs and trans -eQTL regulation across tissue types. © 2017 Yang et al.; Published by Cold Spring Harbor Laboratory Press.

Lymphangioleiomyomatosis Biomarkers Linked to Lung Metastatic Potential and Cell Stemness

PubMed Central

Ruiz de Garibay, Gorka; Herranz, Carmen; Llorente, Alicia; Boni, Jacopo; Serra-Musach, Jordi; Mateo, Francesca; Aguilar, Helena; Gómez-Baldó, Laia; Petit, Anna; Vidal, August; Climent, Fina; Hernández-Losa, Javier; Cordero, Álex; González-Suárez, Eva; Sánchez-Mut, José Vicente; Esteller, Manel; Llatjós, Roger; Varela, Mar; López, José Ignacio; García, Nadia; Extremera, Ana I.; Gumà, Anna; Ortega, Raúl; Plà, María Jesús; Fernández, Adela; Pernas, Sònia; Falo, Catalina; Morilla, Idoia; Campos, Miriam; Gil, Miguel; Román, Antonio; Molina-Molina, María; Ussetti, Piedad; Laporta, Rosalía; Valenzuela, Claudia; Ancochea, Julio; Xaubet, Antoni; Casanova, Álvaro; Pujana, Miguel Angel

2015-01-01

Lymphangioleiomyomatosis (LAM) is a rare lung-metastasizing neoplasm caused by the proliferation of smooth muscle-like cells that commonly carry loss-of-function mutations in either the tuberous sclerosis complex 1 or 2 (TSC1 or TSC2) genes. While allosteric inhibition of the mechanistic target of rapamycin (mTOR) has shown substantial clinical benefit, complementary therapies are required to improve response and/or to treat specific patients. However, there is a lack of LAM biomarkers that could potentially be used to monitor the disease and to develop other targeted therapies. We hypothesized that the mediators of cancer metastasis to lung, particularly in breast cancer, also play a relevant role in LAM. Analyses across independent breast cancer datasets revealed associations between low TSC1/2 expression, altered mTOR complex 1 (mTORC1) pathway signaling, and metastasis to lung. Subsequently, immunohistochemical analyses of 23 LAM lesions revealed positivity in all cases for the lung metastasis mediators fascin 1 (FSCN1) and inhibitor of DNA binding 1 (ID1). Moreover, assessment of breast cancer stem or luminal progenitor cell biomarkers showed positivity in most LAM tissue for the aldehyde dehydrogenase 1 (ALDH1), integrin-ß3 (ITGB3/CD61), and/or the sex-determining region Y-box 9 (SOX9) proteins. The immunohistochemical analyses also provided evidence of heterogeneity between and within LAM cases. The analysis of Tsc2-deficient cells revealed relative over-expression of FSCN1 and ID1; however, Tsc2-deficient cells did not show higher sensitivity to ID1-based cancer inhibitors. Collectively, the results of this study reveal novel LAM biomarkers linked to breast cancer metastasis to lung and to cell stemness, which in turn might guide the assessment of additional or complementary therapeutic opportunities for LAM. PMID:26167915

Self-Efficacy versus Perceived Enjoyment as Predictors of Physical Activity Behavior

PubMed Central

Lewis, Beth A.; Williams, David M.; Frayeh, Amanda L.; Marcus, Bess H.

2015-01-01

Objective Self-efficacy and physical activity (PA) enjoyment are related to PA behavior, but it is unclear which is more important and how they interrelate. The purpose of this study was to examine how these two constructs interrelate to influence PA behavior. Design Participants were low active adults (n=448) participating in a RCT examining the effect of a PA promotion intervention. Participants completed physical activity, enjoyment, and self-efficacy measures at baseline, six, and 12 months. Results Self-efficacy and enjoyment at both baseline and six months predicted PA at 12 months. However, enjoyment was a stronger predictor than self-efficacy in that self-efficacy no longer predicted PA behavior when included alongside enjoyment. In follow-up mediation analyses, enjoyment at six months did not mediate the effect of baseline self-efficacy on 12-month PA; however, six-month self-efficacy mediated the effect of baseline enjoyment on 12-month PA. Conclusion Our results indicate that interventions should perhaps initially focus on increasing enjoyment of physical activity. Greater PA enjoyment appears to influence individuals’ self-reported ability to engage in regular PA (i.e., higher self-efficacy ratings). Additional research is needed to better understand the interrelationships between self-efficacy and enjoyment and how these constructs affect PA. PMID:26541890

Language proficiency and metacognition as predictors of spontaneous rehearsal in children.

PubMed

Bebko, James M; McMorris, Carly A; Metcalfe, Alisa; Ricciuti, Christina; Goldstein, Gayle

2014-03-01

Despite decades of research on fundamental memory strategies such as verbal rehearsal, the potential underlying skills associated with the emergence of rehearsal are still not fully understood. Two studies examined the relative roles of language proficiency and metamemory in predicting rehearsal use, as well as the prediction of metamemory performance by language proficiency. In Study 1, 59 children, 5 to 8 years old, were administered a serial recall task, 2 language measures, a nonverbal cognitive measure, and a rapid automatized naming (RAN) task. Language proficiency, RAN, and age were significant individual predictors of rehearsal use. In hierarchical regression analyses, language proficiency mediated almost completely the age → rehearsal use relation. In addition, automatized naming was a strong but partial mediator of the contribution of language proficiency to rehearsal use. In Study 2, 54 children were administered a metamemory test, a language measure, and a serial recall task. Metamemory skills and, again, language proficiency significantly predicted rehearsal use in the task. The predictive strength of metamemory skills was mediated by the children's language proficiency. The mutually supportive roles of automatized naming, language, and metamemory in the emergence of spontaneous cumulative verbal rehearsal are discussed in the context of the resulting model, along with the minimal roles of age and aspects of intelligence.

Pheromonally mediated sexual isolation among denning populations of red-sided garter snakes, Thamnophis sirtalis parietalis.

PubMed

Lemaster, Michael P; Mason, Robert T

2003-04-01

Utilizing behavioral experiments and chemical analyses, we examined whether pheromonally mediated sexual isolation exists between denning populations of red-sided garter snakes (Thamtnophis sirtalis parietalis) in Manitoba, Canada. Simultaneous choice tests conducted during the breeding season revealed that adult males from a hibernaculum in central Manitoba displayed a strong courtship preference for females from their own population over females from a hibernaculum in western Manitoba, whereas males from the western Manitoba hibernaculum showed no such preference. In addition. trailing experiments testing the response of males from the two hibernacula to familiar and unfamiliar female trails showed similar results, demonstrating that the observed male preference is mediated through chemical cues. Subsequent chemical analysis of the female sexual attractiveness pheromone. a homologous series of long-chain saturated and (omega-9 cis-unsaturated methyl ketones responsible for eliciting male courtship behavior and trailing behavior in garter snakes, showed significant variation in the composition of the pheromone between the two populations. Specifically, the two populations varied in the relative concentrations of individual unsaturated methyl ketones expressed by females. These results suggest that sexual isolation exists to a degree among denning populations of red-sided garter snakes due to variation in the expression of the female sexual attractiveness pheromone.

Social anxiety and suicidal ideation: Test of the utility of the interpersonal-psychological theory of suicide.

PubMed

Buckner, Julia D; Lemke, Austin W; Jeffries, Emily R; Shah, Sonia M

2017-01-01

Social anxiety is related to greater suicidality, even after controlling for depression and other psychopathology. The Interpersonal-Psychological Theory of Suicide (IPTS; Joiner, 2005) proposes that people are vulnerable to wanting to die by suicide if they experience both perceived burdensomeness (sense that one is a burden to others) and thwarted belongingness (a greater sense of alienation from others). Socially anxious persons may be especially vulnerable to these interpersonal factors. The current study tested whether interpersonal IPTS components independently and additively mediate the social anxiety-suicidal ideation (SI) relation among 780 (80.5% female) undergraduates. Social anxiety was significantly, robustly related to SI and to thwarted belongingness and perceived burdensomeness. Social anxiety was indirectly related to SI via thwarted belongingness and perceived burdensomeness. The sum of these indirect effects was significant. Moderated mediation analyses indicated that perceived burdensomeness only mediated the relation between social anxiety and SI at higher levels of thwarted belongingness. Findings highlight that difficulties in interpersonal functioning may serve as potential pathways through which social anxiety may lead to greater suicidality. Findings highlight that difficulties in interpersonal functioning may serve as potential pathways through which social anxiety may lead to greater suicidality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Arg354 in the catalytic centre of bovine liver catalase is protected from methylglyoxal-mediated glycation.

PubMed

Scheckhuber, Christian Q

2015-12-30

In addition to controlled post-translational modifications proteins can be modified with highly reactive compounds. Usually this leads to a compromised functionality of the protein. Methylglyoxal is one of the most common agents that attack arginine residues. Methylglyoxal is also regarded as a pro-oxidant that affects cellular redox homeostasis by contributing to the formation of reactive oxygen species. Antioxidant enzymes like catalase are required to protect the cell from oxidative damage. These enzymes are also targets for methylglyoxal-mediated modification which could severely affect their catalytic activity in breaking down reactive oxygen species to less reactive or inert compounds. Here, bovine liver catalase was incubated with high levels of methylglyoxal to induce its glycation. This treatment did not lead to a pronounced reduction of enzymatic activity. Subsequently methylglyoxal-mediated arginine modifications (hydroimidazolone and dihydroxyimidazolidine) were quantitatively analysed by sensitive nano high performance liquid chromatography/electron spray ionisation/tandem mass spectrometry. Whereas several arginine residues displayed low to moderate levels of glycation (e.g., Arg93, Arg365, Arg444) Arg354 in the active centre of catalase was never found to be modified. Bovine liver catalase is able to tolerate very high levels of the modifying α-oxoaldehyde methylglyoxal so that its essential enzymatic function is not impaired.

Poxvirus-induced alteration of arachidonate metabolism.

PubMed Central

Palumbo, G J; Glasgow, W C; Buller, R M

1993-01-01

Recent evidence suggests that orthopoxviruses have an obligate requirement for arachidonic acid metabolites during replication in vivo and in vitro. Our report indicates that a virus family (Poxviridae) possesses multiple genes that function to regulate arachidonate metabolism. Analyses of BS-C-1 cells infected with cowpox virus or vaccinia virus detected enhanced arachidonate product formation from both the cyclooxygenase (specifically prostaglandins E2 and F2 alpha) and lipoxygenase (specifically 15-hydroxyeicosatetraenoic acid and 12-hydroxyeicosatetraenoic acid) pathways. In contrast, human parainfluenza type 3 or herpes simplex virus type 1 infections did not increase arachidonate metabolism. Results were consistent with a virus early-gene product either directly mediating or inducing a host factor that mediated the up-regulation of arachidonate metabolism, although vaccinia growth factor was not responsible. In addition, the cowpox virus 38-kDa protein-encoding gene, which is associated with inhibition of an inflammatory response, correlated with inhibition of formation of a product biochemically characteristic of (14R,15S)-dihydroxyeicosatetraenoic acid. We propose that orthopoxvirus-induced up-regulation of arachidonic acid metabolism during infection renders the infected cells susceptible to generation of inflammatory mediators from both the cyclooxygenase and the lipoxygenase pathways, and poxviruses, therefore, possess at least one gene (38K) that can alter the lipoxygenase-metabolite spectrum. PMID:8383332

Indirect pathways between depressive symptoms and marital distress: the role of conflict communication, attributions, and attachment style.

PubMed

Heene, Els L D; Buysse, Ann; Van Oost, Paulette

2005-12-01

Previous studies have focused on concomitants of depression and marital distress in order to help explain the relationship between the two, suggesting that several variables, such as conflict communication, attributions, and attachment style, are associated with depression, marital distress, or both. Our contention is that the selected variables may be important mediators (hypothesis 1) or moderators (hypothesis 2) of the concomitance between depression and marital adjustment, exploring the direct and indirect ways in which depressive symptoms and marital adjustment are related. In total, 415 heterosexual couples were recruited, and a series of regression analyses was conducted to test our hypotheses separately for men and women. Results indicated that demand-withdrawal, avoidance, causal attributions, and secure, ambivalent, and avoidant attachment mediated the relation between depressive symptoms and marital adjustment in the female sample, whereas constructive communication and causal and responsible attributions were significant mediators of men's levels of depressive symptoms and marital adjustment. In addition, avoidance and secure attachment moderated the association between depressive symptoms and marital adjustment in the female sample, and causal attributions were significant moderators of the association between depressive symptoms and marital adjustment for men. Several conclusions and implications for theory and future research are discussed.

Assessing the Mediating Role of Social Support in Childhood Maltreatment and Psychopathology Among College Students in Northern Ireland.

PubMed

Lagdon, Susan; Ross, Jana; Robinson, Martin; Contractor, Ateka A; Charak, Ruby; Armour, Cherie

2018-02-01

The detrimental impact of early trauma, particularly childhood maltreatment, on mental health is well documented. Although it is understood that social support can act as a protective factor toward mental health for children who experience such adversity, few studies have addressed the experience of childhood maltreatment and the important function of social support in adulthood. The current study aimed to assess the mediating role of social support in the relationship between childhood experiences of maltreatment and mental health outcomes including anxiety, depression, posttraumatic stress disorder (PTSD), and problematic alcohol use in a sample of university students ( N = 640) from Northern Ireland. Results of binary logistic regression analyses indicated that those reporting experiences of childhood maltreatment were at increased odds of mental health outcomes of PTSD, anxiety, and depression, but not alcohol use. Those reporting greater social support were significantly less likely to report on these mental health outcomes. In addition, the indirect paths from childhood maltreatment through social support to PTSD, depression, and anxiety were all significant, suggesting that social support, particularly family support, is a significant mediator of these relationships. Such findings have important implications for the social care response to children experiencing maltreatment and future support for such children as they transition to adolescence and adulthood.

Self-efficacy versus perceived enjoyment as predictors of physical activity behaviour.

PubMed

Lewis, Beth A; Williams, David M; Frayeh, Amanda; Marcus, Bess H

2016-01-01

Self-efficacy and physical activity (PA) enjoyment are related to PA behaviour, but it is unclear which is more important and how they interrelate. The purpose of this study was to examine how these two constructs interrelate to influence PA behaviour. Participants were low-active adults (n = 448) participating in a RCT examining the effect of a PA promotion intervention. Participants completed physical activity, enjoyment and self-efficacy measures at baseline, six and 12 months. Self-efficacy and enjoyment at both baseline and six months predicted PA at 12 months. However, enjoyment was a stronger predictor than self-efficacy, in that self-efficacy no longer predicted PA behaviour when included alongside enjoyment. In follow-up mediation analyses, enjoyment at six months did not mediate the effect of baseline self-efficacy on 12-month PA; however, six-month self-efficacy mediated the effect of baseline enjoyment on 12-month PA. Our results indicate that interventions should perhaps initially focus on increasing enjoyment of physical activity. Greater PA enjoyment appears to influence individuals' self-reported ability to engage in regular PA (i.e. higher self-efficacy ratings). Additional research is needed to better understand the interrelationships between self-efficacy and enjoyment and how these constructs affect PA.

Characterization of aromatic residue-controlled protein retention in the endoplasmic reticulum of Saccharomyces cerevisiae.

PubMed

Mei, Meng; Zhai, Chao; Li, Xinzhi; Zhou, Yu; Peng, Wenfang; Ma, Lixin; Wang, Qinhong; Iverson, Brent L; Zhang, Guimin; Yi, Li

2017-12-15

An endoplasmic reticulum (ER) retention sequence (ERS) is a characteristic short sequence that mediates protein retention in the ER of eukaryotic cells. However, little is known about the detailed molecular mechanism involved in ERS-mediated protein ER retention. Using a new surface display-based fluorescence technique that effectively quantifies ERS-promoted protein ER retention within Saccharomyces cerevisiae cells, we performed comprehensive ERS analyses. We found that the length, type of amino acid residue, and additional residues at positions -5 and -6 of the C-terminal HDEL motif all determined the retention of ERS in the yeast ER. Moreover, the biochemical results guided by structure simulation revealed that aromatic residues (Phe-54, Trp-56, and other aromatic residues facing the ER lumen) in both the ERS (at positions -6 and -4) and its receptor, Erd2, jointly determined their interaction with each other. Our studies also revealed that this aromatic residue interaction might lead to the discriminative recognition of HDEL or KDEL as ERS in yeast or human cells, respectively. Our findings expand the understanding of ERS-mediated residence of proteins in the ER and may guide future research into protein folding, modification, and translocation affected by ER retention. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Effects of tylosin, tilmicosin and tulathromycin on inflammatory mediators in bronchoalveolar lavage fluid of lipopolysaccharide-induced lung injury.

PubMed

Er, Ayse; Yazar, Enver

2012-12-01

The aim of this study was to determine the anti-inflammatory effects of macrolides through kinetic parameters in bronchoalveolar lavage fluid (BALF) of lipopolysaccharide-induced lung injury. Rats were divided into four groups: lipopolysaccharide (LPS), LPS + tylosin, LPS + tilmicosin and LPS + tulathromycin. BALF samples were collected at sampling times. TNF, IL-1β, IL-6, IL-10 and 13,14-dihydro-15-keto-prostaglandin F2α (PGM) and C-reactive protein (CRP) were analysed. Area under the curve (AUC) and maximum plasma concentration (Cmax) values of inflammatory mediators were determined by a pharmacokinetic computer programme. When inflammatory mediator concentrations were compared between the LPS group and other groups for each sampling time, the three macrolides had no pronounced depressor effect on cytokine levels, but they depressed PGM and CRP levels. In addition, tylosin and tilmicosin decreased the AUC0-24 level of TNF, while tilmicosin decreased the AUC0-24 level of IL-10. Tylosin and tulathromycin decreased the AUC0-24 of PGM, and all three macrolides decreased the AUC0-24 of CRP. Especially tylosin and tulathromycin may have more expressed anti-inflammatory effects than tilmicosin, via depressing the production of inflammatory mediators in the lung. The AUC may be used for determining the effects of drugs on inflammation. In this study, the antiinflammatory effects of these antibiotics were evaluated with kinetic parameters as a new and different approach.

The Erosive Effects of Racism: Reduced Self-control Mediates the Relation between Perceived Racial Discrimination and Substance Use in African American Adolescents

PubMed Central

Gibbons, Frederick X.; O'Hara, Ross E.; Stock, Michelle L.; Gerrard, Meg; Weng, Chih-Yuan; Wills, Thomas A.

2012-01-01

Perceived racial discrimination, self-control, anger, and either substance use or use cognitions were assessed in two studies conducted with samples of African American adolescents. The primary goal was to examine the relation between discrimination and self-control over time; a second goal was to determine if that relation mediates the link between discrimination and substance use found in previous research. Study 1, which included a latent growth curve analysis with three waves of data, indicated that experience with discrimination (from age 10 to age 18) was associated with reduced self-control, which then predicted increased substance use. Additional analyses indicated anger was also a mediator of this discrimination to use relation. Study 2, which was experimental, showed that envisioning an experience involving discrimination was associated with an increase in substance-related responses to double entendre words (e.g., “pot,” “roach”) in a word association task, especially for participants who were low in dispositional self-control. The effect was again mediated by reports of anger. Thus, the “double mediation” pattern was: discrimination → more anger and reduced self-control → increased substance use and/or substance cognitions. Results are discussed in terms of the long-term impact of discrimination on self-control and health behavior. Implications for interventions aimed at ameliorating the negative effects of discrimination and low self-control on health are also discussed. PMID:22390225

Work ability, effort-reward imbalance and disability pension claims.

PubMed

Wienert, J; Spanier, K; Radoschewski, F M; Bethge, M

2017-12-30

Effort-reward imbalance (ERI) and self-rated work ability are known independent correlates and predictors of intended disability pension claims. However, little research has focused on the interrelationship between the three and whether self-rated work ability mediates the relationship between ERI and intended disability pension claims. To investigate whether self-rated work ability mediates the association between ERI and intended disability pension claims. Baseline data from participants of the Third German Sociomedical Panel of Employees, a 5-year cohort study that investigates determinants of work ability, rehabilitation utilization and disability pensions in employees who have previously received sickness benefits, were analysed. We tested direct associations between ERI with intended disability pension claims (Model 1) and self-rated work ability (Model 2). Additionally, we tested whether work ability mediates the association between ERI and intended disability pension claims (Model 3). There were 2585 participants. Model 1 indicated a significant association between ERI and intended disability pension claims. Model 2 showed a significant association between ERI and self-rated work ability. The mediation in Model 3 revealed a significant indirect association between ERI and intended disability pension claims via self-rated work ability. There was no significant direct association between ERI and intended disability pension claims. Our results support the adverse health-related impact of ERI on self-rated work ability and intended disability pension claims. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Does multitasking mediate the relationships between episodic memory, attention, executive functions and apathetic manifestations in traumatic brain injury?

PubMed

Arnould, Annabelle; Rochat, Lucien; Dromer, Emilie; Azouvi, Philippe; Van der Linden, Martial

2018-03-01

Apathy is frequently described in patients with traumatic brain injury (TBI); its negative consequences particularly affect functional independence. Among apathetic manifestations, lack of initiative and lack of interest have mainly been associated with cognitive impairments. However, few studies have been conducted to precisely identify the underlying cognitive processes. Our aims were (1) to determine the best predictor of apathy from among several cognitive processes, including episodic memory and attention/executive mechanisms and multitasking, and (2) to examine to what extent multitasking could mediate the relationships between specific cognitive processes and lack of initiative/interest. Seventy participants (34 patients with TBI matched with 36 control participants) were given a questionnaire to assess anxio-depressive symptoms, four tasks to assess specific cognitive processes, and one task to assess real-life multitasking. Participants' relatives completed an apathy questionnaire. Multitasking, as assessed by the number of goals not achieved, was the only significant predictor of apathetic manifestations. In addition, the mediation analyses revealed that multitasking performance mediated the relationships between verbal episodic memory and lack of initiative/interest, whereas executive and attentional functions were only indirectly related to lack of initiative/interest due to their significant impacts on multitasking. These results shed new light on the aetiology of apathetic manifestations in patients with TBI, indicating how specific cognitive deficits are expressed in real-life multitasking, and consequently, how they may lead to the development and/or maintenance of apathetic manifestations. © 2016 The British Psychological Society.

Cancer survivors in the workplace: sleep disturbance mediates the impact of cancer on healthcare expenditures and work absenteeism.

PubMed

Gonzalez, Brian D; Grandner, Michael A; Caminiti, Courtney B; Hui, Siu-Kuen Azor

2018-06-05

History of cancer is significantly associated with increases in healthcare costs, worse work performance, and higher absenteeism in the workplace. This is particularly important as most cancer survivors return to employment. Sleep disturbance is a largely overlooked potential contributor to these changes. Data from 9488 state employees participating in the Kansas State employee wellness program were used to assess cancer history, sleep disturbance, healthcare expenditures, work performance ratings, and absenteeism. Participants were categorized as having had no history of breast or prostate cancer, a past history only with no current cancer treatment, or current treatment for breast or prostate cancer. Indirect mediation analyses determined whether sleep disturbance mediated the influence of cancer status on outcomes. Employees receiving treatment for breast or prostate cancer had significantly greater healthcare expenditures and absenteeism than those with a past history or no history of cancer (ps < .0001). Sleep disturbance significantly mediated the impact of cancer on healthcare expenditures and absenteeism (ps < .05), accounting for 2 and 8% of the impact of cancer on healthcare expenditure and missed full days of work, respectively. The worse outcomes observed among employees receiving treatment for breast and prostate cancer, the most common forms of cancer among women and men, were partially explained by the impacts of cancer and treatment for cancer on sleep disturbance. These findings suggest that preventing or addressing sleep disturbance may result in economic benefits in addition to improvements in health and quality of life.

Mediators of the Relation Between Community Violence and Sexual Risk Behavior Among Adults Attending a Public Sexually Transmitted Infection Clinic.

PubMed

Senn, Theresa E; Walsh, Jennifer L; Carey, Michael P

2016-07-01

Prior research shows that violence is associated with sexual risk behavior, but little is known about the relation between community violence (i.e., violence that is witnessed or experienced in one's neighborhood) and sexual risk behavior. To better understand contextual influences on HIV risk behavior, we asked 508 adult patients attending a publicly funded STI clinic in the U.S. (54 % male, M age = 27.93, 68 % African American) who were participating in a larger trial to complete a survey assessing exposure to community violence, sexual risk behavior, and potential mediators of the community violence-sexual risk behavior relation (i.e., mental health, substance use, and experiencing intimate partner violence). A separate sample of participants from the same trial completed measures of sexual behavior norms, which were aggregated to create measures of census tract sexual behavior norms. Data analyses controlling for socioeconomic status revealed that higher levels of community violence were associated with more sexual partners for men and with more episodes of unprotected sex with non-steady partners for women. For both men and women, substance use and mental health mediated the community violence-sexual risk behavior relation; in addition, for men only, experiencing intimate partner violence also mediated this relation. These results confirm that, for individuals living in communities with high levels of violence, sexual risk reduction interventions need to address intimate partner violence, substance use, and mental health to be optimally effective.

Mediators of the Relation Between Community Violence and Sexual Risk Behavior Among Adults Attending a Public Sexually Transmitted Infection Clinic

PubMed Central

Senn, Theresa E.; Walsh, Jennifer L.; Carey, Michael P.

2016-01-01

Prior research shows that violence is associated with sexual risk behavior, but little is known about the relation between community violence (i.e., violence that is witnessed or experienced in one's neighborhood) and sexual risk behavior. To better understand contextual influences on HIV risk behavior, we asked 508 adult patients attending a publicly-funded STI clinic in the U.S. (54% male, Mage = 27.93, 68% African American) who were participating in a larger trial to complete a survey assessing exposure to community violence, sexual risk behavior, and potential mediators of the community violence-sexual risk behavior relation (i.e., mental health, substance use, and experiencing intimate partner violence). A separate sample of participants from the same trial completed measures of sexual behavior norms, which were aggregated to create measures of census tract sexual behavior norms. Data analyses controlling for socioeconomic status revealed that higher levels of community violence were associated with more sexual partners for men and with more episodes of unprotected sex with non-steady partners for women. For both men and women, substance use and mental health mediated the community violence-sexual risk behavior relation; in addition, for men only, experiencing intimate partner violence also mediated this relation. These results confirm that, for individuals living in communities with high levels of violence, sexual risk reduction interventions need to address intimate partner violence, substance use, and mental health to be optimally effective. PMID:27000155

Reverse electron transport effects on NADH formation and metmyoglobin reduction.

PubMed

Belskie, K M; Van Buiten, C B; Ramanathan, R; Mancini, R A

2015-07-01

The objective was to determine if NADH generated via reverse electron flow in beef mitochondria can be used for electron transport-mediated reduction and metmyoglobin reductase pathways. Beef mitochondria were isolated from bovine hearts (n=5) and reacted with combinations of succinate, NAD, and mitochondrial inhibitors to measure oxygen consumption and NADH formation. Mitochondria and metmyoglobin were reacted with succinate, NAD, and mitochondrial inhibitors to measure electron transport-mediated metmyoglobin reduction and metmyoglobin reductase activity. Addition of succinate and NAD increased oxygen consumption, NADH formation, electron transport-mediated metmyoglobin reduction, and reductase activity (p<0.05). Addition of antimycin A prevented electron flow beyond complex III, therefore, decreasing oxygen consumption and electron transport-mediated metmyoglobin reduction. Addition of rotenone prevented reverse electron flow, increased oxygen consumption, increased electron transport-mediated metmyoglobin reduction, and decreased NADH formation. Succinate and NAD can generate NADH in bovine tissue postmortem via reverse electron flow and this NADH can be used by both electron transport-mediated and metmyoglobin reductase pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

Work characteristics, socioeconomic position and health: a systematic review of mediation and moderation effects in prospective studies

PubMed Central

Hoven, Hanno; Siegrist, Johannes

2013-01-01

Social inequalities in health persist in modern societies. The contribution of adverse work and employment conditions towards their explanation is analysed by two approaches, mediation and moderation. Yet the relative significance of each approach remains unclear in respective research. We set out to study this question by conducting a systematic literature review. We included all original papers based on prospective observational studies of employed cohorts that were published between January 1980 and October 2012 meeting our search criteria, by using major databases and by observing established quality criteria. 26 reports were included after quality assessment. 17 studies examined the mediation hypothesis and nine studies tested the moderation hypothesis. Moderate support was found for the mediation hypothesis where OR or HR of health according to socioeconomic position (SEP) were reduced in a majority of analyses after introducing work characteristics in multivariate models. Evidence in favour of the moderation hypothesis was found in some studies, demonstrating stronger effects of adverse work on health among people with low SEP. Despite some support in favour of the two hypotheses future research should aim at reducing the heterogeneity in defining and measuring core variables and at applying advanced statistical analyses. Policy recommendations would benefit from a higher degree of consistency of respective research evidence. PMID:23739492

Work characteristics, socioeconomic position and health: a systematic review of mediation and moderation effects in prospective studies.

PubMed

Hoven, Hanno; Siegrist, Johannes

2013-09-01

Social inequalities in health persist in modern societies. The contribution of adverse work and employment conditions towards their explanation is analysed by two approaches, mediation and moderation. Yet the relative significance of each approach remains unclear in respective research. We set out to study this question by conducting a systematic literature review. We included all original papers based on prospective observational studies of employed cohorts that were published between January 1980 and October 2012 meeting our search criteria, by using major databases and by observing established quality criteria. 26 reports were included after quality assessment. 17 studies examined the mediation hypothesis and nine studies tested the moderation hypothesis. Moderate support was found for the mediation hypothesis where OR or HR of health according to socioeconomic position (SEP) were reduced in a majority of analyses after introducing work characteristics in multivariate models. Evidence in favour of the moderation hypothesis was found in some studies, demonstrating stronger effects of adverse work on health among people with low SEP. Despite some support in favour of the two hypotheses future research should aim at reducing the heterogeneity in defining and measuring core variables and at applying advanced statistical analyses. Policy recommendations would benefit from a higher degree of consistency of respective research evidence.

Childhood abuse and late-life depression: Mediating effects of psychosocial factors for early- and late-onset depression.

PubMed

Wielaard, Ilse; Hoyer, Mathijs; Rhebergen, Didi; Stek, Max L; Comijs, Hannie C

2018-03-01

Childhood abuse makes people vulnerable to developing depression, even in late life. Psychosocial factors that are common in late life, such as loneliness or lack of a partner, may explain this association. Our aim was to investigate whether the association between childhood abuse and depression in older adults can be explained by psychosocial factors. Cross-sectional data were derived from the Netherlands Study of Depression in Older Persons (aged 60-93), including 132 without lifetime depression, 242 persons with an early-onset depression (<60 years), and 125 with a late-onset (≥60 years) depression. Childhood abuse (yes/no) and a frequency-based childhood abuse index were included. Multinomial regression and multivariable mediation analyses were used to examine the association between childhood abuse and the onset of depression, and the influence of loneliness, social network, and partner status. Multinomial regression analyses showed a significant association between childhood abuse and the childhood abuse index with early- and late-onset depression. Multivariable mediation analyses showed that the association between childhood abuse and early-onset depression was partly mediated by social network size and loneliness. This was particularly present for emotional neglect and psychological abuse, but not for physical and sexual abuse. No psychosocial mediators were found for the association between childhood abuse and late-onset depression. A smaller social network and feelings of loneliness mediate the association between childhood abuse and early-onset depression in older adults. Our findings show the importance of detecting childhood abuse as well as the age at depression onset and mapping of relevant psychosocial factors in the treatment of late-life depression. Copyright © 2018 John Wiley & Sons, Ltd.

Improvement in emotional eating associated with an enhanced body image in obese women: mediation by weight-management treatments' effects on self-efficacy to resist emotional cues to eating.

PubMed

Annesi, James J; Mareno, Nicole

2015-12-01

To assess effects of cognitive-behavioural weight-loss treatments on self-efficacy to control emotionally cued eating and whether those changes mediate relationships between body satisfaction and emotional eating. Emotional eating is common, especially in women with obesity. A better understanding of relationships of its psychosocial correlates might benefit behavioural weight-loss treatments. A field-based, quantitative study incorporated two theoretically derived weight-loss treatments using repeated measures analyses that employed validated surveys. Women with obesity volunteered for a community-based weight-loss study and were assigned to either a treatment of a manual plus phone support (n = 47), or in-person contacts emphasizing self-regulation (n = 48), over 6 months. Both emphasized physical activity, healthy eating and building self-efficacy for enabling the health-behaviour changes. Data were collected between 2013-2014. Multiple regression analyses assessed predictors of self-efficacy change. Mixed-model analysis of variances assessed treatment differences in psychosocial changes. Mediation analyses assessed mediation of the relationships between body satisfaction and emotional eating changes. Changes in Overall mood and Self-regulation significantly predicted change in Self-efficacy to control emotionally cued eating. Changes in Body satisfaction, Emotional eating, Mood, Self-regulating eating and Self-efficacy were significant overall, and each significantly greater in the in-person treatment. Self-efficacy significantly mediated the relationship between changes in Body satisfaction and Emotional eating total (and Emotional eating when depressed or anxious, but not when frustrated/angry). Results clarified mediation of the dynamic relationship between body satisfaction and emotional eating, which might enable behavioural weight-loss treatments to better-address emotional eating. © 2015 John Wiley & Sons Ltd.

No mediating effects of glycemic control and inflammation on the association between vitamin D and lung function in the general population.

PubMed

Kaul, Anne; Gläser, Sven; Hannemann, Anke; Stubbe, Beate; Felix, Stefan B; Nauck, Matthias; Ewert, Ralf; Friedrich, Nele

2017-04-01

Vitamin D deficiency is discussed to be associated with lung health. While former studies focused on subjects suffering from pulmonary diseases, we aimed to investigate the association of 25-hydroxy vitamin D [25(OH)D] with lung function in the general population and examined whether mediating effects of inflammation, glycemic control or renal function exist. 1404 participants from the Study of Health in Pomerania with pulmonary function testing assessed by expiratory volume in 1 s (FEV 1 ), forced vital capacity (FVC), total lung capacity and Krogh index were used. Adjusted analysis of variance, linear regression models and mediation analyses were performed. Significant positive associations between 25(OH)D levels and FEV 1 , FVC and Krogh index were found. Mediator analyses revealed no mediating effect of inflammation (fibrinogen), glycemic control (HbA1c) or renal function (eGFR) on associations with FEV 1 or FVC. With respect to Krogh-Index, the association to 25(OH)D was slightly mediated by fibrinogen with a proportion mediated of 9.7%. Significant positive associations of 25(OH)D with lung function were revealed in a general population. The proposed mediating effects of inflammation, glycemic control and renal function on these relations were not confirmed. Further studies examining the causality of the association between 25(OH)D and lung function are necessary. Copyright © 2017 Elsevier Ltd. All rights reserved.

Motivation toward Physical Exercise and Subjective Wellbeing: The Mediating Role of Trait Self-Control

PubMed Central

Briki, Walid

2016-01-01

Motivation toward physical exercise (MPE) and trait self-control (TSC) were identified as key predictors of subjective wellbeing (SWB). However, there has not been any research designed to examine the mediating role of TSC in the relationship between MPE and SWB. The present study utilizes self-determination theory, control-process theory of self-regulation, and theory of multiple pathways of TSC in order to examine whether TSC mediates the relationships of autonomous MPE (A-MPE), controlled MPE (C-MPE), and impersonal MPE (NO-MPE) with SWB using structural equation modeling (XLSTAT PLS). Three hundred seventeen adult American individuals (Mage = 32.97, SDage = 11.30), who reported to be regular exercisers, voluntarily answered questionnaires assessing MPE, TSC, and SWB. Correlational analyses revealed positive relationships between A-MPE, TSC, and SWB, and negative relationships of C-MPE and NO-MPE with TSC and SWB. Mediation analyses revealed that TSC mediated the relationships of A-MPE (partial mediation) and C-MPE (full mediation) with SWB, but did not mediate the relationship between NO-MPE and SWB. The estimates of the quality of the hypothesized model were acceptable (outer model GoF = 0.935; absolute GoF = 0.330; relative GoF = 0.942; inner model GoF = 1.008; R2 = 36.947%). Finally, this study supports the view that MPE can influence SWB through TSC, and incites to pursue the examination of the relationships between self-determined motivation, self-regulation mechanisms, and health-related outcomes. PMID:27761126

Mediating role of borderline personality disorder traits in the effects of childhood maltreatment on suicidal behaviour among mood disorder patients.

PubMed

Aaltonen, K I; Rosenström, T; Baryshnikov, I; Karpov, B; Melartin, T; Suominen, K; Heikkinen, M; Näätänen, P; Koivisto, M; Joffe, G; Isometsä, E

2017-07-01

Substantial evidence supports an association between childhood maltreatment and suicidal behaviour. However, few studies have examined factors mediating this relationship among patients with unipolar or bipolar mood disorders. Depressive disorder and bipolar disorder (ICD-10-DCR) patients (n=287) from the Helsinki University Psychiatric Consortium (HUPC) Study were surveyed on self-reported childhood experiences, current depressive symptoms, borderline personality disorder traits, and lifetime suicidal behaviour. Psychiatric records served to complement the information on suicide attempts. We examined by formal mediation analyses whether (1) the effect of childhood maltreatment on suicidal behaviour is mediated through borderline personality disorder traits and (2) the mediation effect differs between lifetime suicidal ideation and lifetime suicide attempts. The impact of childhood maltreatment in multivariate models on either lifetime suicidal ideation or lifetime suicide attempts showed comparable total effects. In formal mediation analyses, borderline personality disorder traits mediated all of the total effect of childhood maltreatment on lifetime suicide attempts, but only one fifth of the total effect on lifetime suicidal ideation. The mediation effect was stronger for lifetime suicide attempts than for lifetime suicidal ideation (P=0.002) and independent of current depressive symptoms. The mechanisms of the effect of childhood maltreatment on suicidal ideation versus suicide attempts may diverge among psychiatric patients with mood disorders. Borderline personality disorder traits may contribute to these mechanisms, although the influence appears considerably stronger for suicide attempts than for suicidal ideation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Placental Abruption and Perinatal Mortality With Preterm Delivery as a Mediator: Disentangling Direct and Indirect Effects

PubMed Central

Ananth, Cande V.; VanderWeele, Tyler J.

2011-01-01

The authors use recent methodology in causal inference to disentangle the direct and indirect effects that operate through a mediator in an exposure-response association paradigm. They demonstrate how total effects can be partitioned into direct and indirect effects even when the exposure and mediator interact. The impact of bias due to unmeasured confounding on the exposure-response association is assessed through a series of sensitivity analyses. These methods are applied to a problem in perinatal epidemiology to examine the extent to which the effect of abruption on perinatal mortality is mediated through preterm delivery. Data on over 26 million US singleton births (1995–2002) were utilized. Risks of mortality among abruption and nonabruption births were 102.7 and 6.2 per 1,000 births, respectively. Risk ratios of the natural direct and indirect (preterm delivery-mediated) effects of abruption on mortality were 10.18 (95% confidence interval: 9.80, 10.58) and 1.35 (95% confidence interval: 1.33, 1.38), respectively. The proportion of increased mortality risk mediated through preterm delivery was 28.1%, with even higher proportions associated with deliveries at earlier gestational ages. Sensitivity analyses underscore that the qualitative conclusions of some mediated effects and substantial direct effects are reasonably robust to unmeasured confounding of a fairly considerable magnitude. PMID:21430195

Evidence for the indirect effects of perceived public stigma on psychosocial outcomes: The mediating role of self-stigma.

PubMed

Kao, Yu-Chen; Lien, Yin-Ju; Chang, Hsin-An; Wang, Sheng-Chiang; Tzeng, Nian-Sheng; Loh, Ching-Hui

2016-06-30

This study examined the possible mediating role of self-stigma in the relationship between perceived public stigma and psychosocial outcomes and how this mechanism may be contingent on illness severity in a non-Western (Chinese) sample. A total of 251 participants, namely 151 psychiatric outpatients with psychotic disorders and 100 psychiatric outpatients without psychotic disorders, completed a questionnaire on stigma and psychosocial outcomes that covered topics such as self-esteem, depressive symptoms, and subjective quality of life (QoL). Using a cross-sectional design, ordinary least squares regression and bootstrapping mediation analyses were used to test whether self-stigma mediated the relationship between perceived public stigma and psychosocial outcomes and whether this mediating process was moderated by diagnostic status. The results indicated that self-stigma mediated the effect of perceived public stigma on psychosocial outcomes such as self-esteem, depressive symptoms, and subjective QoL among both patients with psychotic disorders and those without psychotic disorders after controlling for demographic and clinical characteristics. Further, moderated mediation analyses revealed that the indirect effect of perceived public stigma on psychosocial outcomes were not moderated by the status of psychotic diagnoses. Self-stigma might be an essential and tractable target for interventions aimed at breaking the vicious cycle of discrimination and stigmatization toward people with mental illness regardless of their diagnoses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Confounding in statistical mediation analysis: What it is and how to address it.

PubMed

Valente, Matthew J; Pelham, William E; Smyth, Heather; MacKinnon, David P

2017-11-01

Psychology researchers are often interested in mechanisms underlying how randomized interventions affect outcomes such as substance use and mental health. Mediation analysis is a common statistical method for investigating psychological mechanisms that has benefited from exciting new methodological improvements over the last 2 decades. One of the most important new developments is methodology for estimating causal mediated effects using the potential outcomes framework for causal inference. Potential outcomes-based methods developed in epidemiology and statistics have important implications for understanding psychological mechanisms. We aim to provide a concise introduction to and illustration of these new methods and emphasize the importance of confounder adjustment. First, we review the traditional regression approach for estimating mediated effects. Second, we describe the potential outcomes framework. Third, we define what a confounder is and how the presence of a confounder can provide misleading evidence regarding mechanisms of interventions. Fourth, we describe experimental designs that can help rule out confounder bias. Fifth, we describe new statistical approaches to adjust for measured confounders of the mediator-outcome relation and sensitivity analyses to probe effects of unmeasured confounders on the mediated effect. All approaches are illustrated with application to a real counseling intervention dataset. Counseling psychologists interested in understanding the causal mechanisms of their interventions can benefit from incorporating the most up-to-date techniques into their mediation analyses. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The association between home environmental variables and soft drink consumption among adolescents. Exploration of mediation by individual cognitions and habit strength.

PubMed

Tak, N I; Te Velde, S J; Oenema, A; Van der Horst, K; Timperio, A; Crawford, D; Brug, J

2011-04-01

Soft-drink consumption is one of the important target behaviours for the prevention of excessive weight gain among adolescents. To be able to modify these behaviours in obesity prevention interventions, further understanding of the underlying factors and mediational pathways is required. The present study aimed to explore associations between home environment variables and adolescent soft drink consumption and potential mediation of these associations by individual cognitions derived from the Theory of Planned Behaviour and habit strength. The ENDORSE study (N=1005) provided data on soft drink consumption and on home environment variables related to soft drink consumption (availability, accessibility, parental modelling, and parental rules), cognitive variables (intention, attitude, perceived behaviour control, and parental norm) and habit strength. Multiple mediation analyses were conducted using regression analyses according to the steps described by MacKinnon to assess the association between home environment variables and soft drink consumption and mediation of these associations by cognitive variables and habit strength. The bootstrapping method was used to calculate the confidence intervals. There were significant associations between the home environment variables and soft drink consumption. After inclusion of the mediators the strength of these associations was reduced. In the multiple mediator models, habit strength (39.4-62.6%) and intention (19.1-36.6%) were the strongest mediators. Intention and habit strength partly mediate the associations between home environment factors and soft drink consumption, suggesting that home environment variables influence soft drink consumption both indirectly and directly. Copyright © 2011 Elsevier Ltd. All rights reserved.

Linking organizational resources and work engagement to employee performance and customer loyalty: the mediation of service climate.

PubMed

Salanova, Marisa; Agut, Sonia; Peiró, José María

2005-11-01

This study examined the mediating role of service climate in the prediction of employee performance and customer loyalty. Contact employees (N=342) from 114 service units (58 hotel front desks and 56 restaurants) provided information about organizational resources, engagement, and service climate. Furthermore, customers (N=1,140) from these units provided information on employee performance and customer loyalty. Structural equation modeling analyses were consistent with a full mediation model in which organizational resources and work engagement predict service climate, which in turn predicts employee performance and then customer loyalty. Further analyses revealed a potential reciprocal effect between service climate and customer loyalty. Implications of the study are discussed, together with limitations and suggestions for future research. ((c) 2005 APA, all rights reserved).

A cohort study on self-reported role stressors at work and poor sleep: does sense of coherence moderate or mediate the associations?

PubMed

Hansen, Åse Marie; Grynderup, Matias Brødsgaard; Rugulies, Reiner; Conway, Paul Maurice; Garde, Anne Helene; Török, Eszter; Mikkelsen, Eva Gemzøe; Persson, Roger; Hogh, Annie

2018-05-01

The aim of the present study was to examine the bidirectional associations between subjective role ambiguity and role conflicts at work, respectively, and self-reported sleep 2 years later. In addition, we also examine whether sense of coherence (SOC) moderate or mediate the association between role stressors and poor sleep and between poor sleep and role stressors. We used questionnaire data collected in 2006 and 2008 from the Workplace Bullying and Harassment cohort. In 2006, 3363 responded to the questionnaire and in 2008 1671 responded. In total, 1569 participants responded in both 2006 and 2008 to the questions on role stressors (in terms of role ambiguity and role conflicts at work) and sleep problems in both 2006 and 2008. Sleep problems were assessed with the awakening index (AWI) and the disturbed sleep index (DSI). Moderation and mediation analyses of the association were estimated using structural equation modelling. We found a prospective association between role stressors and sleep problems [beta values were 0.07 (95% CI 0.03-0.11) and 0.05 (CI 0.01-0.10) for DSI and AWI, respectively] when adjusting for sleep problems at baseline, age, sex, and life style factors (i.e. alcohol, smoking, and leisure time physical activity). SOC moderated the association showing that participants with lower SOC scores who reported higher role ambiguity reported sleep problems to a higher extent than participants with high SOC scores. SOC also mediated the association between role stressors and sleep problems. We also found support for sleep problems at baseline and role stressors 2 years later [DSI 0.04 (CI 0.00-0.08) and 0.15 (CI 0.09-0.21)] for role ambiguity and role conflicts, respectively. Similar results were observed for AWI. Subjective role stressors were prospectively associated with sleep problems. Yet, sleep problems could also prospectively predict subjective role stressors (i.e. reverse causation). The analyses also showed that SOC may be regarded as both a mediating and a moderating factor of the association between subjective role conflicts and poor sleep. We found that SOC moderated the prospective association so participants with low SOC report more sleep problems with subjective role conflicts compared to participants with high SOC. Finally, we also found SOC mediated the prospective association between subjective role stressors and sleep problems and the reverse association.

Subunit architecture and functional modular rearrangements of the transcriptional Mediator complex

PubMed Central

Tsai, Kuang-Lei; Tomomori-Sato, Chieri; Sato, Shigeo; Conaway, Ronald C.; Conaway, Joan W.; Asturias, Francisco J.

2014-01-01

SUMMARY The multisubunit Mediator comprising ~30 distinct proteins, plays an essential role in gene expression regulation by acting as a bridge between DNA binding transcription factors and the RNA polymerase II (RNAPII) transcription machinery. Efforts to uncover the Mediator mechanism have been hindered by a poor understanding of its structure, subunit organization, and conformational rearrangements. By overcoming biochemical and image analysis hurdles, we obtained accurate EM structures of yeast and human Mediators. Subunit localization experiments, docking of partial X-ray structures, and biochemical analyses resulted in comprehensive mapping of yeast Mediator subunits and a complete reinterpretation of our previous Mediator organization model. Large-scale Mediator rearrangements depend on changes at the interfaces between previously described Mediator modules, which appear to be facilitated by factors conducive to transcription initiation. Conservation across eukaryotes of Mediator structure, subunit organization, and RNA polymerase II interaction suggest conservation of fundamental aspects of the Mediator mechanism. PMID:24882805

How teacher emotional support motivates students: The mediating roles of perceived peer relatedness, autonomy support, and competence.

PubMed

Ruzek, Erik A; Hafen, Christopher A; Allen, Joseph P; Gregory, Anne; Mikami, Amori Yee; Pianta, Robert C

2016-04-01

Multilevel mediation analyses test whether students' mid-year reports of classroom experiences of autonomy, relatedness with peers, and competence mediate associations between early in the school year emotionally-supportive teacher-student interactions (independently observed) and student-reported academic year changes in mastery motivation and behavioral engagement. When teachers were observed to be more emotionally-supportive in the beginning of the school year, adolescents reported academic year increases in their behavioral engagement and mastery motivation. Mid-year student reports indicated that in emotionally-supportive classrooms, adolescents experienced more developmentally-appropriate opportunities to exercise autonomy in their day-to-day activities and had more positive relationships with their peers. Analyses of the indirect effects of teacher emotional support on students' engagement and motivation indicated significant mediating effects of autonomy and peer relatedness experiences, but not competence beliefs, in this sample of 960 students (ages 11-17) in the classrooms of 68 middle and high school teachers in 12 U.S. schools.

How teacher emotional support motivates students: The mediating roles of perceived peer relatedness, autonomy support, and competence

PubMed Central

Ruzek, Erik A.; Hafen, Christopher A.; Allen, Joseph P.; Gregory, Anne; Mikami, Amori Yee; Pianta, Robert C.

2017-01-01

Multilevel mediation analyses test whether students' mid-year reports of classroom experiences of autonomy, relatedness with peers, and competence mediate associations between early in the school year emotionally-supportive teacher-student interactions (independently observed) and student-reported academic year changes in mastery motivation and behavioral engagement. When teachers were observed to be more emotionally-supportive in the beginning of the school year, adolescents reported academic year increases in their behavioral engagement and mastery motivation. Mid-year student reports indicated that in emotionally-supportive classrooms, adolescents experienced more developmentally-appropriate opportunities to exercise autonomy in their day-to-day activities and had more positive relationships with their peers. Analyses of the indirect effects of teacher emotional support on students' engagement and motivation indicated significant mediating effects of autonomy and peer relatedness experiences, but not competence beliefs, in this sample of 960 students (ages 11–17) in the classrooms of 68 middle and high school teachers in 12 U.S. schools. PMID:28190936

The relationship between physical appearance concerns, disgust, and anti-fat prejudice.

PubMed

O'Brien, Kerry S; Daníelsdóttir, Sigrún; Ólafsson, Ragnar P; Hansdóttir, Ingunn; Fridjónsdóttir, Thorarna G; Jónsdóttir, Halla

2013-09-01

This study examined relationships between physical appearance concerns (fear of fat, body image disturbance; BIDQ), disgust, and anti-fat prejudice (dislike, blame), and tested whether disgust mediates relationships between physical appearance concerns and anti-fat prejudice. Participants (N=1649; age=28 years) provided demographic data and completed measures of anti-fat prejudice, tendency to feel disgust, and physical appearance concerns. Univariate, multivariate, and mediation analyses were conducted. Univariate and multivariate associations were found between fear of fat, BIDQ, disgust, and anti-fat prejudice for women. For women only, mediation analyses showed that disgust partially mediated relationships between physical appearance concerns and dislike of fat people. For men, univariate and multivariate relationships were found between fear of fat, and dislike and blame of fat people, but disgust was not related to anti-fat prejudice. Newer constructs centering on physical appearance concerns and disgust appear promising candidates for understanding anti-fat prejudice. Copyright © 2013 Elsevier Ltd. All rights reserved.

The relationship between pain, disability, guilt and acceptance in low back pain: a mediation analysis.

PubMed

Serbic, Danijela; Pincus, Tamar

2017-08-01

Pain-related guilt is a common yet unexplored psychological factor in low back pain (LBP). It has recently been linked to greater depression, anxiety and disability in LBP, hence an understanding of how it can be managed in the presence of pain and disability is necessary. Since acceptance of pain has been shown to be associated with improved outcomes in chronic pain, we examined whether it might also help reduce guilt in people with LBP. To this end, a series of mediation analyses were conducted on data from 287 patients with chronic LBP, in which acceptance of pain was tested as a mediator of the relationship between pain/disability and guilt. Results showed that acceptance of pain reduced the impact of pain/disability on pain-related guilt in all mediation analyses. Pain-related guilt might be a potential target for acceptance based interventions, thus this relationship should be further tested using longitudinal designs.

[Relationship Between General Cognitive Abilities and School Achievement: The Mediation Role of Learning Behavior].

PubMed

Weber, H M; Rücker, S; Büttner, P; Petermann, F; Daseking, M

2015-10-01

General cognitive abilities are still considered as the most important predictor of school achievement and success. Whether the high correlation (r=0.50) can be explained by other variables has not yet been studied. Learning behavior can be discussed as one factor that influences the relationship between general cognitive abilities and school achievement. This study examined the relationship between intelligence, school achievement and learning behavior. Mediator analyses were conducted to check whether learning behavior would mediate the relationship between general cognitive abilities and school grades in mathematics and German. Statistical analyses confirmed that the relationship between general cognitive abilities and school achievement was fully mediated by learning behavior for German, whereas intelligence seemed to be the only predictor for achievement in mathematics. These results could be confirmed by non-parametric bootstrapping procedures. RESULTS indicate that special training of learning behavior may have a positive impact on school success, even for children and adolescents with low IQ. © Georg Thieme Verlag KG Stuttgart · New York.

Anterior insular cortex mediates bodily sensibility and social anxiety

PubMed Central

Shibata, Midori; Moriguchi, Yoshiya; Umeda, Satoshi

2013-01-01

Studies in psychiatry and cognitive neuroscience have reported an important relationship between individual interoceptive accuracy and anxiety level. This indicates that greater attention to one’s bodily state may contribute to the development of intense negative emotions and anxiety disorders. We hypothesized that reactivity in the anterior insular cortex underlies the intensity of interoceptive awareness and anxiety. To elucidate this triadic mechanism, we conducted functional magnetic resonance imaging (fMRI) and mediation analyses to examine the relationship between emotional disposition and activation in the anterior insular cortex while participants evaluated their own emotional and bodily states. Our results indicated that right anterior insular activation was positively correlated with individual levels of social anxiety and neuroticism and negatively correlated with agreeableness and extraversion. The results of the mediation analyses revealed that activity in the right anterior insula mediated the activity of neural correlates of interoceptive sensibility and social fear. Our findings suggest that attention to interoceptive sensation affects personality traits through how we feel emotion subjectively in various situations. PMID:22977199

Missed or Delayed Medical Care Appointments by Older Users of Nonemergency Medical Transportation

PubMed Central

MacLeod, Kara E.; Ragland, David R.; Prohaska, Thomas R.; Smith, Matthew Lee; Irmiter, Cheryl; Satariano, William A.

2015-01-01

Purpose of the Study: This study identified factors associated with canceling nonemergency medical transportation appointments among older adult Medicaid patients. Design and Methods: Data from 125,913 trips for 2,913 Delaware clients were examined. Mediation analyses, as well as, multivariate logistic regressions were conducted. Results: Over half of canceled trips were attributed to client reasons (e.g., no show, refusal). Client characteristics (e.g., race, sex, functional status) were associated with cancelations; however, these differed based on the cancelation reason. Regularly scheduled trips were less likely to be canceled. Implications: The evolving American health care system may increase service availability. Additional policies can improve service accessibility and overcome utilization barriers. PMID:24558264

Dectin-1-mediated signaling leads to characteristic gene expressions and cytokine secretion via spleen tyrosine kinase (Syk) in rat mast cells.

PubMed

Kimura, Yukihiro; Chihara, Kazuyasu; Honjoh, Chisato; Takeuchi, Kenji; Yamauchi, Shota; Yoshiki, Hatsumi; Fujieda, Shigeharu; Sada, Kiyonao

2014-11-07

Dectin-1 recognizes β-glucan and plays important roles for the antifungal immunity through the activation of spleen tyrosine kinase (Syk) in dendritic cells or macrophages. Recently, expression of Dectin-1 was also identified in human and mouse mast cells, although its physiological roles were largely unknown. In this report, rat mast cell line RBL-2H3 was analyzed to investigate the molecular mechanism of Dectin-1-mediated activation and responses of mast cells. Treatment of cells with Dectin-1-specific agonist curdlan induced tyrosine phosphorylation of cellular proteins and the interaction of Dectin-1 with the Src homology 2 domain of Syk. These responses depended on tyrosine phosphorylation of the hemi-immunoreceptor tyrosine-based activation motif in the cytoplasmic tail of Dectin-1, whereas they were independent of the γ-subunit of high-affinity IgE receptor. DNA microarray and real-time PCR analyses showed that Dectin-1-mediated signaling stimulated gene expression of transcription factor Nfkbiz and inflammatory cytokines, such as monocyte chemoattractant protein-1, IL-3, IL-4, IL-13, and tumor necrosis factor (TNF)-α. The response was abrogated by pretreatment with Syk inhibitor R406. These results suggest that Syk is critical for Dectin-1-mediated activation of mast cells, although the signaling differs from that triggered by FcϵRI activation. In addition, these gene expressions induced by curdlan stimulation were specifically observed in mast cells, suggesting that Dectin-1-mediated signaling of mast cells offers new insight into the antifungal immunity. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

The prohibitin-repressive interaction with E2F1 is rapidly inhibited by androgen signalling in prostate cancer cells

PubMed Central

Koushyar, S; Economides, G; Zaat, S; Jiang, W; Bevan, C L; Dart, D A

2017-01-01

Prohibitin (PHB) is a tumour suppressor molecule with pleiotropic activities across several cellular compartments including mitochondria, cell membrane and the nucleus. PHB and the steroid-activated androgen receptor (AR) have an interplay where AR downregulates PHB, and PHB represses AR. Additionally, their cellular locations and chromatin interactions are in dynamic opposition. We investigated the mechanisms of cell cycle inhibition by PHB and how this is modulated by AR in prostate cancer. Using a prostate cancer cell line overexpressing PHB, we analysed the gene expression changes associated with PHB-mediated cell cycle arrest. Over 1000 gene expression changes were found to be significant and gene ontology analysis confirmed PHB-mediated repression of genes essential for DNA replication and synthesis, for example, MCMs and TK1, via an E2F1 regulated pathway—agreeing with its G1/S cell cycle arrest activity. PHB is known to inhibit E2F1-mediated transcription, and the PHB:E2F1 interaction was seen in LNCaP nuclear extracts, which was then reduced by androgen treatment. Upon two-dimensional western blot analysis, the PHB protein itself showed androgen-mediated charge differentiation (only in AR-positive cells), indicating a potential dephosphorylation event. Kinexus phosphoprotein array analysis indicated that Src kinase was the main interacting intracellular signalling hub in androgen-treated LNCaP cells, and that Src inhibition could reduce this AR-mediated charge differentiation. PHB charge change may be associated with rapid dissociation from chromatin and E2F1, allowing the cell cycle to proceed. The AR and androgens may deactivate the repressive functions of PHB upon E2F1 leading to cell cycle progression, and indicates a role for AR in DNA replication licensing. PMID:28504694

Self-Esteem and Problematic Drinking in China: A Mediated Model

PubMed Central

Zhai, Hui; Yang, Yanjie; Sui, Hong; Wang, Wenbo; Chen, Lu; Qiu, Xiaohui; Yang, Xiuxian; Qiao, Zhengxue; Wang, Lin; Zhu, Xiongzhao; Yang, Jiarun

2015-01-01

Background Although self-esteem is related to problematic drinking, the mechanisms by which it affects drinking remain unclear. The purpose of this study was to determine whether coping mechanisms mediate the relationship between self-esteem and problematic drinking among Chinese men and women with alcohol use disorders and to recommend appropriate interventions for drinking problems. Methods A cross-sectional survey was conducted in Harbin, Heilongjiang Province, China. A sample of 5,689 community residents was screened, and 517 male and 172 female problematic drinkers were chosen to participate in this study. A self-esteem scale, a coping questionnaire and an alcohol use disorder identification test were completed in order to assess participants’ self-esteem, coping mechanisms and alcohol use disorders, respectively. Participants’ socio-demographic data were also gathered at this stage. The resulting data were examined via descriptive statistics, correlations and bootstrap analyses. Results Lower self-esteem levels were related to problematic drinking, and there were no gender differences in the relationship between self-esteem and problematic drinking. A relationship between low self-esteem and negative coping was observed only in men. Negative coping thus mediated the relationship between self-esteem and problematic drinking among men, but this was not the case for women. Positive coping did not mediate the relationship between self-esteem and problematic drinking among the participants, regardless of gender. Conclusions Self-esteem and coping strategies are correlated among problematic drinkers. In addition, there are gender differences in the manners in which negative coping mediates the relationship between self-esteem and problematic drinking. Problematic drinking interventions directed at males should simultaneously address low self-esteem and negative coping. PMID:26451595

Exposure to apoptotic activated CD4+ T cells induces maturation and APOBEC3G-mediated inhibition of HIV-1 infection in dendritic cells.

PubMed

Mohanram, Venkatramanan; Johansson, Ulrika; Sköld, Annette E; Fink, Joshua; Kumar Pathak, Sushil; Mäkitalo, Barbro; Walther-Jallow, Lilian; Spetz, Anna-Lena

2011-01-01

Dendritic cells (DCs) are activated by signaling via pathogen-specific receptors or exposure to inflammatory mediators. Here we show that co-culturing DCs with apoptotic HIV-infected activated CD4(+) T cells (ApoInf) or apoptotic uninfected activated CD4(+) T cells (ApoAct) induced expression of co-stimulatory molecules and cytokine release. In addition, we measured a reduced HIV infection rate in DCs after co-culture with ApoAct. A prerequisite for reduced HIV infection in DCs was activation of CD4(+) T cells before apoptosis induction. DCs exposed to ApoAct or ApoInf secreted MIP-1α, MIP-1β, MCP-1, and TNF-α; this effect was retained in the presence of exogenous HIV. The ApoAct-mediated induction of co-stimulatory CD86 molecules and reduction of HIV infection in DCs were partially abrogated after blocking TNF-α using monoclonal antibodies. APOBEC3G expression in DCs was increased in co-cultures of DCs and ApoAct but not by apoptotic resting CD4(+) T cells (ApoRest). Silencing of APOBEC3G in DC abrogated the HIV inhibitory effect mediated by ApoAct. Sequence analyses of an env region revealed significant induction of G-to-A hypermutations in the context of GG or GA dinucleotides in DNA isolated from DCs exposed to HIV and ApoAct. Thus, ApoAct-mediated DC maturation resulted in induction of APOBEC3G that was important for inhibition of HIV-infection in DCs. These findings underscore the complexity of differential DC responses evoked upon interaction with resting as compared with activated dying cells during HIV infection.

Cravings as a mediator and moderator of drinking outcomes in the COMBINE study.

PubMed

Subbaraman, Meenakshi Sabina; Lendle, Samuel; van der Laan, Mark; Kaskutas, Lee Ann; Ahern, Jennifer

2013-10-01

Investigators of the COMBINE (Combining Medications and Behavioral Interventions for Alcoholism) study examined whether combining medications with a behavioral intervention would improve outcomes over monotherapies. Unexpectedly, the combination did not offer any advantage over either treatment alone. This study aimed to explain the lack of incremental benefit offered by the combination over either monotherapy by assessing the role of cravings as a treatment mediator and moderator. Secondary mediation and moderation analyses of COMBINE study data. Eleven United States academic sites. A total of 863 patients randomized to one of four treatment groups: naltrexone (100 mg/day; n = 209), the combined behavioral intervention (CBI, n = 236), naltrexone and CBI combined (n = 213) and placebo naltrexone (n = 205). Percentage of days abstinent (PDA) measured between 13 and 16 weeks post-baseline. Cravings, the potential mediator/moderator, were measured at baseline, weeks 4 and 12 using the Obsessive-Compulsive Drinking Scale. Compared with placebo, naltrexone, CBI and the combination all increased PDA by an additional 6-10 percentage points for those with high cravings (P < 0.05 for all three treatment groups). None had significant effects on PDA for those with low cravings. The effects of all three treatments were mediated at least partially by cravings; craving reduction explained 48-53% of treatment effects (P < 0.05 for all three treatment groups). Furthermore, naltrexone appeared to reduce cravings at 4 weeks, while CBI did not reduce cravings until 12 weeks. The Combining Medications and Behavioral Interventions for Alcoholism (COMBINE) naltrexone + CBI combination may not be more beneficial than either monotherapy because craving reduction is a common mechanism of both. © 2013 Society for the Study of Addiction.

The molecular mechanism of mediation of adsorbed serum proteins to endothelial cells adhesion and growth on biomaterials.

PubMed

Yang, Dayun; Lü, Xiaoying; Hong, Ying; Xi, Tingfei; Zhang, Deyuan

2013-07-01

To explore molecular mechanism of mediation of adsorbed proteins to cell adhesion and growth on biomaterials, this study examined endothelial cell adhesion, morphology and viability on bare and titanium nitride (TiN) coated nickel titanium (NiTi) alloys and chitosan film firstly, and then identified the type and amount of serum proteins adsorbed on the three surfaces by proteomic technology. Subsequently, the mediation role of the identified proteins to cell adhesion and growth was investigated with bioinformatics analyses, and further confirmed by a series of cellular and molecular biological experiments. Results showed that the type and amount of adsorbed serum proteins associated with cell adhesion and growth was obviously higher on the alloys than on the chitosan film, and these proteins mediated endothelial cell adhesion and growth on the alloys via four ways. First, proteins such as adiponectin in the adsorbed protein layer bound with cell surface receptors to generate signal transduction, which activated cell surface integrins through increasing intracellular calcium level. Another way, thrombospondin 1 in the adsorbed protein layer promoted TGF-β signaling pathway activation and enhanced integrins expression. The third, RGD sequence containing proteins such as fibronectin 1, vitronectin and thrombospondin 1 in the adsorbed protein layer bound with activated integrins to activate focal adhesion pathway, increased focal adhesion formation and actin cytoskeleton organization and mediated cell adhesion and spreading. In addition, the activated focal adhesion pathway promoted the expression of cell growth related genes and resulted in cell proliferation. The fourth route, coagulation factor II (F2) and fibronectin 1 in the adsorbed protein layer bound with cell surface F2 receptor and integrin, activated regulation of actin cytoskeleton pathway and regulated actin cytoskeleton organization. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mediation analysis of decisional balance, sun avoidance and sunscreen use in the precontemplation and preparation stages for sun protection.

PubMed

Santiago-Rivas, Marimer; Velicer, Wayne F; Redding, Colleen

2015-01-01

Mediation analyses of sun protection were conducted testing structural equation models using longitudinal data with three waves. An effect was said to be mediated if the standardised path between processes of change, decisional balance and sun protection outcomes was significant. Longitudinal models of sun protection using data from individuals in the precontemplation (N = 964) and preparation (N = 463) stages who participated of an expert system intervention. Nine processes of change for sun protection, decisional balance constructs of sun protection (pros and cons), sun avoidance behaviour and sunscreen use. With the exception of two processes in the preparation stage, processes of change predicted the pros (r = .126-.614), and the pros predicted the outcomes (r = .181-.272). Three models with the cons as mediator in the preparation stage, and none in the precontemplation stage, showed a mediated relationship between processes and outcomes. In general, mediation analyses found both the process of change-to-pros and pros-to-behaviour paths significant for both precontemplation and preparation stages, and for both sun avoidance and sunscreen use outcomes. Findings provide support for the importance of assessing the role of underlying risk cognitions in improving sun protection adherence.

Adolescent Depression and Negative Life Events, the Mediating Role of Cognitive Emotion Regulation

PubMed Central

Stikkelbroek, Yvonne; Bodden, Denise H. M.; Kleinjan, Marloes; Reijnders, Mirjam; van Baar, Anneloes L.

2016-01-01

Background Depression during adolescence is a serious mental health problem. Difficulties in regulating evoked emotions after stressful life events are considered to lead to depression. This study examined if depressive symptoms were mediated by various cognitive emotion regulation strategies after stressful life events, more specifically, the loss of a loved one, health threats or relational challenges. Methods We used a sample of 398 adolescents (Mage = 16.94, SD = 2.90), including 52 depressed outpatients, who all reported stressful life event(s). Path analyses in Mplus were used to test mediation, for the whole sample as well as separately for participants scoring high versus low on depression, using multigroup analyses. Results Health threats and relational challenging stressful life events were associated with depressive symptoms, while loss was not. More frequent use of maladaptive strategies was related to more depressive symptoms. More frequent use of adaptive strategies was related to less depressive symptoms. Specific life events were associated with specific emotion regulation strategies. The relationship between challenging, stressful life events and depressive symptoms in the whole group was mediated by maladaptive strategies (self-blame, catastrophizing and rumination). No mediation effect was found for adaptive strategies. Conclusion The association between relational challenging, stressful life events and depressive symptoms was mediated by maladaptive, cognitive emotion regulation strategies. PMID:27571274

Mediation Analysis of Decisional Balance, Sun Avoidance, and Sunscreen Use in the Precontemplation and Preparation Stages for Sun Protection

PubMed Central

Velicer, Wayne F.; Redding, Colleen

2015-01-01

Objective Mediation analyses of sun protection were conducted testing structural equation models using longitudinal data with three waves. An effect was said to be mediated if the standardized path between processes of change, decisional balance, and sun protection outcomes were significant. Design Longitudinal models of sun protection using data from individuals in the precontemplation (N=964) and preparation (N =463) stages who participated of an expert system intervention. Main Outcome Measures Nine processes of change for sun protection, decisional balance constructs of sun protection (pros and cons), sun avoidance behavior, and sunscreen use. Results With the exception of two processes in the preparation stage, processes of change predicted the pros (r= .126 to .614), and the pros predicted the outcomes (r= .181 to .272). Three models with the cons as mediator in the preparation stage, and none in the precontemplation stage, showed a mediated relationship between processes and outcomes. Conclusion In general, mediation analyses found both the process of change-to-pros and pros-to-behavior paths significant for both precontemplation and preparation stages, and for both sun avoidance and sunscreen use outcomes. Findings provide support for the importance of assessing the role of underlying risk cognitions in improving sun protection adherence. PMID:26040293

Negative evaluations of self and others, and peer victimization as mediators of the relationship between childhood adversity and psychotic experiences in adolescence: the moderating role of loneliness.

PubMed

Murphy, Siobhan; Murphy, Jamie; Shevlin, Mark

2015-09-01

Previous research has identified an association between traumatic experiences and psychotic symptoms. Few studies, however, have explored the underlying mechanisms and contingent nature of these associations in an integrated model. This study aimed to test a moderated mediation model of negative childhood experiences, associated cognitive processes, and psychotic experiences within a context of adolescent loneliness. Cross-sectional survey. A total of 785 Northern Irish secondary school adolescents completed the survey. A moderated mediation model was specified and tested. Childhood experiences of threat and subordination were directly associated with psychotic experiences. Analyses indicated that peer victimization was a mediator of this effect and that loneliness moderated this mediated effect. A new model is proposed to provide an alternative framework for assessing the association between trauma and psychotic experience in adolescence that recognizes loneliness as a significant contextual moderator that can potentially strengthen the trauma-psychosis relationship. Moderated mediation analyses poses an alternative framework to the understanding of trauma-psychosis associations Adolescent loneliness is a vulnerability factor within this association Data are based on a Northern Irish sample with relatively low levels of loneliness Cross-sectional data cannot explore the developmental course of these experiences in adolescence. © 2015 The British Psychological Society.

N-acetyl cysteine inhibits lipopolysaccharide-mediated induction of interleukin-6 synthesis in MC3T3-E1 cells through the NF-kB signaling pathway.

PubMed

Guo, Ling; Zhang, Hui; Li, Wangyang; Zhan, Danting; Wang, Min

2018-06-06

Interleukin-6 (IL-6) is a potent stimulator of osteoclastic activity. Lipopolysaccharide (LPS) has been shown to regulate the expression of potent inflammatory factors, including TNF-α and IL-6. Currently, effective therapeutic treatments for bacteria-caused bone destruction are limited. N-acetyl cysteine (NAC) is an antioxidant small molecule that possibly modulates osteoblastic differentiation. However, whether NAC can affect the LPS-mediated reduction of IL-6 synthesis in MC3T3-E1 cells is still unknown. The aim of this study was to investigate the role of NAC in the LPS -mediated reduction of IL-6 synthesis by MC3T3-E1 cells and to explore the underlying molecular mechanisms. In addition, we aimed to determine the involvement of the NF-kB pathway in any changes in IL-6 expression observed in response to LPS and NAC. MC3T3-E1 cells (ATCC, CRL-2593) were cultured in α-minimum essential medium. Cells were stimulated using NAC or LPS at various concentrations. Cell proliferation was observed at multiple time points using a cell counting kit 8 (CCK-8). IL-6 mRNA expression and protein synthesis were determined using quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay analyses. NF-kB mRNA expression and protein synthesis was determined using qPCR and Western blots analyses. The results demonstrate that LPS induced IL-6 and NF-kB mRNA expression and protein synthesis in the cultured MC3T3-E1 cells. However, these effects were abolished following pre-treatment with NAC. Pretreatment with NAC (1 mmol/l) or BAY11-7082 (10 μmol/l) both significantly inhibited the NF-kB activity induced by LPS. NAC inhibits the LPS-mediated induction of IL-6 synthesis in MC3T3-E1 cells through the NF-kB pathway. Copyright © 2018 Elsevier Ltd. All rights reserved.

Normative Beliefs, Expectancies, and Alcohol-Related Problems among College Students; Implications for Theory and Practice.

ERIC Educational Resources Information Center

Fearnow-Kenny, Melodie D.; Wyrick, David L.; Hansen, William B.; Dyreg, Doug; Beau, Dan B.

2001-01-01

Investigation (1) examined interrelations among normative beliefs, alcohol expectancies, and alcohol-related problems, and (2) investigated whether alcohol-related expectancies mediate associations between normative beliefs and alcohol-related problems. Analyses revealed that alcohol expectancies mediate the relationship between normative beliefs…

Parenting Behavior and Adolescent Conduct Problems: Reciprocal and Mediational Effects

ERIC Educational Resources Information Center

Simons-Morton, Bruce; Chen, Rusan; Hand, Laura Shaffer; Haynie, Denise L.

2008-01-01

This research examined the relationship between parenting practices and adolescent conduct problems and the mediation of these relationships by two parent-adolescent relationship variables, conflict and psychological autonomy. Autoregressive latent trajectory (ALT) analyses were used to assess relationships over time between parent practices and…

Parenting Practices and Adolescent Sexual Behavior: A Longitudinal Study

ERIC Educational Resources Information Center

Bersamin, Melina; Todd, Michael; Fisher, Deborah A.; Hill, Douglas L.; Grube, Joel W.; Walker, Samantha

2008-01-01

The effects of parental attitudes, practices, and television mediation on adolescent sexual behaviors were investigated in a study of adolescent sexuality and media (N = 887). Confirmatory factor analyses supported an eight-factor parenting model with television mediation factors as constructs distinct from general parenting practices. Logistic…

Population Distribution Analyses Reveal a Hierarchy of Molecular Players Underlying Parallel Endocytic Pathways

PubMed Central

Gupta, Gagan D.; Howes, Mark T.; Chandran, Ruma; Das, Anupam; Menon, Sindhu; Parton, Robert G.; Sowdhamini, R.; Thattai, Mukund; Mayor, Satyajit

2014-01-01

Single-cell-resolved measurements reveal heterogeneous distributions of clathrin-dependent (CD) and -independent (CLIC/GEEC: CG) endocytic activity in Drosophila cell populations. dsRNA-mediated knockdown of core versus peripheral endocytic machinery induces strong changes in the mean, or subtle changes in the shapes of these distributions, respectively. By quantifying these subtle shape changes for 27 single-cell features which report on endocytic activity and cell morphology, we organize 1072 Drosophila genes into a tree-like hierarchy. We find that tree nodes contain gene sets enriched in functional classes and protein complexes, providing a portrait of core and peripheral control of CD and CG endocytosis. For 470 genes we obtain additional features from separate assays and classify them into early- or late-acting genes of the endocytic pathways. Detailed analyses of specific genes at intermediate levels of the tree suggest that Vacuolar ATPase and lysosomal genes involved in vacuolar biogenesis play an evolutionarily conserved role in CG endocytosis. PMID:24971745

Predictors of attachment security in preschool children from intact and divorced families.

PubMed

Nair, Hira; Murray, Ann D

2005-09-01

The authors selected 58 mother-child dyads from divorced and intact families to participate in a study on the impact of divorce on preschoolers' attachment security. The authors explored pathways that lead to security of attachment. They found that mothers from divorced families were younger, had lower income levels, and had lower levels of education compared with their intact counterparts. Divorced mothers also reported significantly higher levels of stress, depression, need for social support, and conflict with their spouses. Mothers from intact families were more likely to use positive (authoritative) parenting styles compared with divorced mothers. Children in the divorced group had lower security scores on the Attachment Q-Set instrument (E. Waters, 1995). Regression analyses indicated that parenting style made a direct (independent) contribution to attachment security. In addition, temperament was related to attachment security, but temperament did not diminish the association of parenting style with attachment security. Furthermore, regression analyses indicated that the relationship of divorce to attachment security was mediated by parenting style.

Results of an independent evaluation of Project ALERT delivered in schools by Cooperative Extension.

PubMed

St Pierre, Tena L; Osgood, D Wayne; Mincemoyer, Claudia C; Kaltreider, D Lynne; Kauh, Tina J

2005-12-01

Reported are results of an independent effectiveness study of the Project ALERT drug prevention program implemented in eight Pennsylvania middle schools by outside program leaders employed by Cooperative Extension. In this randomized, 2-cohort longitudinal evaluation, 1,649 seventh-grade students completed a pretest and four waves of posttests over the 2-year program and 1-year follow-up. Project ALERT's effectiveness was tested through a 3-level hierarchical linear model. Analyses failed to yield any positive effects for substance use or mediators for use in the adult or teen-assisted delivery of the curriculum. An extensive set of additional analyses detected no differential program effects by student risk level, gender, school, or level of implementation quality. Potential explanations for outcomes relative to Project ALERT's original effectiveness trial are discussed, as well as implications for future research, including the need to conduct independent effectiveness studies of previously validated programs in a variety of contexts.

The neurocognitive profile of mood disorders - a review of the evidence and methodological issues.

PubMed

Porter, Richard J; Robinson, Lucy J; Malhi, Gin S; Gallagher, Peter

2015-12-01

Cognitive abnormalities are an established part of the symptomatology of mood disorders. However, questions still exist regarding the exact profile of these deficits in terms of the domains most affected, their origins, and their relationship to clinical subtypes. This review aims to examine the current state of the evidence and to examine ways in which the field may be advanced. Studies examining cognitive function in bipolar disorder (BD) and unipolar major depression (MDD) were examined. Given the number and variability of such studies, particular attention was paid to meta-analyses and to meta-regression analyses which examined the possible mediators of cognitive impairment. Meta-analyses are available for MDD and BD in both depression and euthymia. Several analyses examine mediators. Results do not support the presence of domain specific deficits but rather a moderate deficit across a range of domains in BD and in MDD. The data on clinical mediators is inconsistent, even with regard to the effect of mood state. A two-tiered approach, with the broad-based application of standardized measures on a large-scale, and the refined application of theoretically driven experimental development would significantly further our understanding of neurocognitive processing in mood disorder. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The mediating role of interpersonal cognition on the relationships between personality and adolescent ego development.

PubMed

Liu, Yih-Lan

2013-01-01

The author investigated whether interpersonal cognition mediated the relationships between defense, social sensitivity, and ego development. Participants (N = 616; M age = 15.66 years, SD = .52 year; 276 boys) from northwestern Taiwan completed a battery of questionnaires. Structural equation modeling and mediation analyses supported the hypothesis that interpersonal cognition would mediate the path between defense and ego development, and the path between social sensitivity and ego development. Defense and social sensitivity were found to have direct effects on ego development. The study provides evidence of the mediating effect of interpersonal cognition on the association between personality and ego development.

Cognitive mediation of clinical improvement after intensive exposure therapy of agoraphobia and social phobia.

PubMed

Vögele, Claus; Ehlers, Anke; Meyer, Andrea H; Frank, Monika; Hahlweg, Kurt; Margraf, Jürgen

2010-03-01

The present study investigated cognitive mediation of clinical improvement in patients with agoraphobia (N=427) or social phobia (N=98) receiving high-density exposure therapy in a naturalistic clinical treatment setting. Patients were assessed before therapy, 6 weeks after the end of therapy, and 1 year thereafter, using a self-report assessment battery. Lower level mediation analyses provided support for the notion that cognitive changes partially mediate clinical improvement after exposure therapy. Changes in cognitions relating to physical catastrophes mediated treatment outcome only for patients with agoraphobia, whereas changes in cognitions about loss of control mediated outcome for both agoraphobia and social phobia patients. Changes in relationship satisfaction did not mediate symptomatic improvement. The results extend previous findings by demonstrating mediation in an unselected clinical sample and by providing evidence for the specificity of mediation effects. They further support the importance of cognitive changes in cognitive-behavior therapy. (c) 2009 Wiley-Liss, Inc.

A Tutorial in Bayesian Potential Outcomes Mediation Analysis.

PubMed

Miočević, Milica; Gonzalez, Oscar; Valente, Matthew J; MacKinnon, David P

2018-01-01

Statistical mediation analysis is used to investigate intermediate variables in the relation between independent and dependent variables. Causal interpretation of mediation analyses is challenging because randomization of subjects to levels of the independent variable does not rule out the possibility of unmeasured confounders of the mediator to outcome relation. Furthermore, commonly used frequentist methods for mediation analysis compute the probability of the data given the null hypothesis, which is not the probability of a hypothesis given the data as in Bayesian analysis. Under certain assumptions, applying the potential outcomes framework to mediation analysis allows for the computation of causal effects, and statistical mediation in the Bayesian framework gives indirect effects probabilistic interpretations. This tutorial combines causal inference and Bayesian methods for mediation analysis so the indirect and direct effects have both causal and probabilistic interpretations. Steps in Bayesian causal mediation analysis are shown in the application to an empirical example.

Can ethnic background differences in children's body composition be explained by differences in energy balance-related behaviors? A mediation analysis within the energy-project.

PubMed

Fernández-Alvira, Juan Miguel; Te Velde, Saskia J; Jiménez-Pavón, David; Manios, Yannis; Singh, Amika; Moreno, Luis A; Brug, Johannes

2013-01-01

In affluent countries, children from non-native ethnicity have in general less favourable body composition indicators and energy balance-related behaviors (EBRBs) than children from native ethnicity. However, differences between countries have been reported. A school-based survey among 10-12 years old children was conducted in seven European countries with a standardized protocol. Weight, height and waist circumference were measured; engagement in EBRBs was self-reported. For those countries with significant ethnic differences in body composition (Greece and the Netherlands), multilevel mediation analyses were conducted, to test the mediating effect of the EBRBs in the association between ethnic background and body composition indicators. Analyses were adjusted for gender and age, and for parental education in a later step. Partial mediation was found for sugared drinks intake and sleep duration in the Greek sample, and breakfast in the Dutch sample. A suppression effect was found for engagement in sports activites in the Greek sample. Ethnic differences in children's body composition were partially mediated by differences in breakfast skipping in the Netherlands and sugared drinks intake, sports participation and sleep duration in Greece.

Does Competence Mediate the Associations between Puberty and Internalizing or Externalizing Problems in Adolescent Girls

PubMed Central

Negriff, Sonya; Hillman, Jennifer, B.; Dorn, Lorah D.

2011-01-01

Purpose To examine separate mediational models linking a) menarcheal status or b) pubertal timing to internalizing and externalizing problems through competence. Method Cross-sectional analyses of 262 adolescent girls (11–17 years; M=14.93, SD=2.17) enrolled in a longitudinal study examining the association of psychological functioning and smoking with reproductive and bone health. Measures of menarcheal status (pre/post), pubertal timing (early, on-time, or late), internalizing and externalizing behavior, and perceived competence (parent and adolescent report) were obtained. Structural Equation Modeling was used for analyses. Results Perceived competence was found to fully mediate the association between menarcheal status and parent report of internalizing and externalizing problems. For adolescent report, there was a full mediation effect for internalizing problems but a partial mediation effect for externalizing problems. Being menarcheal was related to lower competence which was related to higher internalizing and externalizing problems. Models including pubertal timing were not significant. Conclusions Perceived competence is important in understanding the associations between menarcheal status and internalizing and externalizing problems. Interventions targeting competence, particularly in post-menarcheal girls, may reduce or prevent problem behaviors. PMID:21939864

Physical inactivity mediates the association between the perceived exercising behavior of social network members and obesity: a cross-sectional study.

PubMed

Leroux, Janette S; Moore, Spencer; Richard, Lucie; Gauvin, Lise

2012-01-01

Social networks influence the spread of depression, health behaviors, and obesity. The social networks of older urban-dwelling adults were examined to assess whether physical inactivity mediated the association between social networks and obesity. Data come from the Montreal Neighborhood Networks and Healthy Aging study (n=2707). Self-reported height and weight were used to calculate body mass index (BMI) with obesity defined as a BMI ≥ 30. A name generator/interpreter instrument was used to elicit participants' core ties (i.e., alters), and assess whether alters exercised regularly and resided in participants' neighborhoods. The International Physical Activity Questionnaire was used to measure physical inactivity. Separate multilevel logistic regression analyses were conducted for younger (18-54 years) and older (55 years plus) age groups to examine the association between the exercising behavior of alters and obesity. Ancillary analyses examined whether the residential location of alters was associated with obesity. Mediation analyses assessed whether physical inactivity mediated the association between alter exercising behavior and obesity. Models adjusted for participant socio-demographic and -economic characteristics. Among the older age stratum (55 years plus), physically inactive individuals were more likely obese (OR 2.14; 95% CIs: 1.48-3.10); participants who had more exercising alters were less likely obese (OR: 0.85; 95% CIs: 0.72-0.99). Physical inactivity mediated the association between exercising alters and obesity. Ancillary analyses showed that having exercising alters in the neighborhood compared to other locations tended to reduce the odds of obesity. This work demonstrates the importance of social networks among older adults in facilitating a physically active lifestyle and reducing the odds of obesity. Such findings can inform the design of public health interventions that seek to improve the environmental conditions supporting the physical activity of older adults.

Effect of NaI/I 2 mediators on properties of PEO/LiAlO 2 based all-solid-state supercapacitors

NASA Astrophysics Data System (ADS)

Yin, Yijing; Zhou, Juanjuan; Mansour, Azzam N.; Zhou, Xiangyang

NaI/I 2 mediators and activated carbon were added into poly(ethylene oxide) (PEO)/lithium aluminate (LiAlO 2) electrolyte to fabricate composite electrodes. All solid-state supercapacitors were fabricated using the as prepared composite electrodes and a Nafion 117 membrane as a separator. Cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge measurements were conducted to evaluate the electrochemical properties of the supercapacitors. With the addition of NaI/I 2 mediators, the specific capacitance increased by 27 folds up to 150 F g -1. The specific capacitance increased with increases in the concentration of mediators in the electrodes. The addition of mediators also reduced the electrode resistance and rendered a higher electron transfer rate between mediator and mediator. The stability of the all-solid-state supercapacitor was tested over 2000 charge/discharge cycles.

Psychological mediators related to clinical outcome in cognitive behavioural therapy for coronary heart disease: A sub-analysis from the SUPRIM trial.

PubMed

Norlund, Fredrika; Olsson, Erik Mg; Pingel, Ronnie; Held, Claes; Svärdsudd, Kurt; Gulliksson, Mats; Burell, Gunilla

2017-06-01

Background The Secondary Prevention in Uppsala Primary Healthcare Project (SUPRIM) was a randomized controlled trial of a group-based cognitive behavioural therapy stress management programme for patients with coronary heart disease. The project was successful in reducing the risk of fatal or non-fatal first recurrent cardiovascular events. The aim of this study was to analyse the effect of cognitive behavioural therapy on self-rated stress, somatic anxiety, vital exhaustion and depression and to study the associations of these factors with the reduction in cardiovascular events. Methods A total of 362 patients were randomly assigned to intervention or usual care groups. The psychological outcomes were assessed five times during 24 months and analysed using linear mixed models. The mediating roles of the outcomes were analysed using joint modelling of the longitudinal and time to event data. Results The intervention had a positive effect on somatic anxiety ( p < 0.05), reflecting a beneficial development over time compared with the controls. Stress, vital exhaustion and depression did not differ between the groups over time. Mediator analysis suggested that somatic anxiety may have mediated the effect of treatment on cardiovascular events. Conclusions The intervention had a small positive effect on somatic anxiety, but did not affect stress, vital exhaustion or depression in patients with coronary heart disease. Somatic anxiety was associated with an increased risk of cardiovascular events and might act as a partial mediator in the treatment effect on cardiovascular events. However, the mechanisms between the intervention and the protective cardiovascular outcome remain to be identified.

Distress and Diabetes Treatment Adherence: A Mediating Role for Perceived Control

PubMed Central

Gonzalez, Jeffrey S.; Shreck, Erica; Psaros, Christina; Safren, Steven A.

2014-01-01

Objective To understand independent pathways linking emotional distress, medication adherence and glycemic control in adults with type 2 diabetes, as well as the potential mediating effects of perceived control over illness and self-efficacy. Methods Adults with type 2 diabetes (N = 142) were recruited for an intervention study evaluating cognitive behavioral therapy for adherence and depression. Depressive symptom severity was assessed via semi-structured interview. Validated self-reports assessed diabetes-related distress, perceived control over diabetes (perceived control), self-efficacy for diabetes self-management and medication adherence. Glycemic control was evaluated by hemoglobin A1c (A1C). Only baseline data were included in correlational and linear regression analyses. Results Perceived control was an important mediator for both medication adherence and A1C outcomes. Specifically, regression analyses demonstrated that diabetes distress, but not depression severity, was significantly related to medication adherence and A1C. Self-efficacy and perceived control were also independently associated with medication adherence and A1C. Mediation analyses demonstrated a significant indirect effect for diabetes distress and medication adherence, through perceived control and self-efficacy. The relationship between distress and A1C was accounted for by an indirect effect through perceived control. Conclusion Results demonstrate that diabetes-related emotional distress is associated with poorer treatment adherence and glycemic control among adults with type 2 diabetes; these relationships were partially mediated through perceived control over diabetes. Perceptions of one’s personal ability to influence diabetes may be important in understanding the pathway between emotional distress and poor diabetes treatment outcomes. PMID:25110840

Subcortical volumetric changes across the adult lifespan: subregional thalamic atrophy accounts for age-related sensorimotor performance declines.

PubMed

Serbruyns, Leen; Leunissen, Inge; Huysmans, Toon; Cuypers, Koen; Meesen, Raf L; van Ruitenbeek, Peter; Sijbers, Jan; Swinnen, Stephan P

2015-04-01

Even though declines in sensorimotor performance during healthy aging have been documented extensively, its underlying neural mechanisms remain unclear. Here, we explored whether age-related subcortical atrophy plays a role in sensorimotor performance declines, and particularly during bimanual manipulative performance (Purdue Pegboard Test). The thalamus, putamen, caudate and pallidum of 91 participants across the adult lifespan (ages 20-79 years) were automatically segmented. In addition to studying age-related changes in the global volume of each subcortical structure, local deformations within these structures, indicative of subregional volume changes, were assessed by means of recently developed shape analyses. Results showed widespread age-related global and subregional atrophy, as well as some notable subregional expansion. Even though global atrophy failed to explain the observed performance declines with aging, shape analyses indicated that atrophy in left and right thalamic subregions, specifically subserving connectivity with the premotor, primary motor and somatosensory cortical areas, mediated the relation between aging and performance decline. It is concluded that subregional volume assessment by means of shape analyses offers a sensitive tool with high anatomical resolution in the search for specific age-related associations between brain structure and behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

The alpha subunit of Go interacts with promyelocytic leukemia zinc finger protein and modulates its functions.

PubMed

Won, Jung Hee; Park, Jung Sik; Ju, Hyun Hee; Kim, Soyeon; Suh-Kim, Haeyoung; Ghil, Sung Ho

2008-05-01

Heterotrimeric GTP-binding proteins (G proteins) mediate signal transduction generated by neurotransmitters and hormones. Go, a member of the Go/Gi family, is the most abundant heterotrimeric G protein in the brain. Most mechanistic analyses on Go activation demonstrate that its action is mediated by the Gbetagamma dimer; downstream effectors for its alpha subunit (Goalpha) have not been clearly defined. Here, we employ the yeast two-hybrid system to screen for Goalpha-interacting partners in a cDNA library from human fetal brain. The transcription factor promyelocytic leukemia zinc finger protein (PLZF) specifically bound to Goalpha. Interactions between PLZF and Goalpha were confirmed using in vitro and in vivo affinity binding assays. Activated Goalpha interacted directly with PLZF, and enhanced its function as a transcriptional and cell growth suppressor. Notably, PLZF activity was additionally promoted by the Go/ialpha-coupled cannabinoid receptor (CB) in HL60 cells endogenously expressing CB and PLZF. These results collectively suggest that Goalpha modulates the function of PLZF via direct interactions. Our novel findings provide insights into the diverse cellular roles of Goalpha and its coupled receptor.

BRI2 (ITM2b) Inhibits Aβ Deposition in Vivo

PubMed Central

Kim, Jungsu; Miller, Victor M.; Levites, Yona; West, Karen Jansen; Zwizinski, Craig W.; Moore, Brenda D.; Troendle, Fredrick J.; Bann, Maralyssa; Verbeeck, Christophe; Price, Robert W.; Smithson, Lisa; Sonoda, Leilani; Wagg, Kayleigh; Rangachari, Vijayaraghavan; Zou, Fanggeng; Younkin, Steven G.; Graff-Radford, Neill; Dickson, Dennis; Rosenberry, Terrone; Golde, Todd E.

2008-01-01

Analyses of the biologic effects of mutations in the BRI2 (ITM2b) and the amyloid β precursor protein (APP) genes support the hypothesis that cerebral accumulation of amyloidogenic peptides in familial British and familial Danish dementias and Alzheimer’s disease (AD) is associated with neurodegeneration. We have used somatic brain transgenic technology to express the BRI2 and BRI2-Aβ1-40 transgenes in amyloid β protein precursor (APP) mouse models. Expression of BRI2-Aβ1-40 mimics the suppressive effect previously observed using conventional transgenic methods, further validating the somatic brain transgenic methodology. Unexpectedly, we also find that expression of wild type human BRI2 reduces cerebral Aβ deposition in an AD mouse model. Additional data indicate that the 23 amino acid peptide, Bri23, released from BRI2 by normal processing is present in human cerebrospinal fluid (CSF), inhibits Aβ aggregation in vitro, and mediates its anti-amyloidogenic effect in vivo. These studies demonstrate that BRI2 is a novel mediator of Aβ deposition in vivo. PMID:18524908

Pan-cancer analysis of somatic copy number alterations implicates IRS4 and IGF2 in enhancer hijacking

PubMed Central

Weischenfeldt, Joachim; Dubash, Taronish; Drainas, Alexandros P.; Mardin, Balca R.; Chen, Yuanyuan; Stütz, Adrian M.; Waszak, Sebastian M.; Bosco, Graziella; Halvorsen, Ann Rita; Raeder, Benjamin; Efthymiopoulos, Theocharis; Erkek, Serap; Siegl, Christine; Brenner, Hermann; Brustugun, Odd Terje; Dieter, Sebastian M.; Northcott, Paul A.; Petersen, Iver; Pfister, Stefan M.; Schneider, Martin; Solberg, Steinar K.; Thunissen, Erik; Weichert, Wilko; Zichner, Thomas; Thomas, Roman; Peifer, Martin; Helland, Aslaug; Ball, Claudia R.; Jechlinger, Martin; Sotillo, Rocio; Glimm, Hanno; Korbel, Jan O.

2018-01-01

Extensive prior research has focused on somatic copy-number alterations (SCNAs) affecting cancer genes, yet the extent to which recurrent SCNAs exert their influence through rearranging cis-regulatory elements remains unclear. Here, we present a framework for inferring cancer-related gene overexpression resulting from cis-regulatory element reorganization (e.g., enhancer hijacking), by integrating SCNAs, gene expression data, and information on chromatin interaction domains. Analysis of 7,416 cancer genomes uncovered several pan-cancer candidate genes, including IRS4, SMARCA1 and TERT. We demonstrate that IRS4 overexpression in lung cancer associates with recurrent deletions in cis, and present evidence supporting a tumor-promoting role. We additionally pursued cancer type-specific analyses, uncovering IGF2 as a target for enhancer hijacking in colorectal cancer. IGF2-containing tandem duplications result in the de novo formation of a 3D contact domain comprising IGF2 and a lineage-specific super-enhancer, which mediates high-level gene activation. Our framework enables systematic inference of cis-regulatory element rearrangements mediating dysregulation in cancer. PMID:27869826

Femininity and Kin-Directed Altruism in Androphilic Men: A Test of an Evolutionary Developmental Model.

PubMed

VanderLaan, Doug P; Petterson, Lanna J; Vasey, Paul L

2016-04-01

Androphilia refers to sexual attraction and arousal toward males whereas gynephilia refers to sexual attraction and arousal toward females. This study tested the adaptive feminine phenotype model of the evolution of male androphilia via kin selection, which posits that the development of an evolved disposition toward elevated kin-directed altruism among androphilic males is contingent on the behavioral expression of femininity. Gynephilic men, androphilic women, and androphilic men (N = 387) completed measures of childhood and adulthood gender expression and concern for kin's well-being. Adulthood femininity correlated positively with uncle/aunt-like tendencies among androphilic men and women. Although androphilic women reported greater willingness to invest in nieces and nephews than gynephilic and androphilic men, mediation analyses indicated that adult femininity completely mediated these group differences. In addition, changes in the expression of femininity between childhood and adulthood were associated with parallel changes in concern for the well-being of kin among androphilic men. Thus, these findings suggest that femininity is key to the expression of kin-directed altruism among androphilic males and may have been important in the evolution of male androphilia.

Relational aggression and psychological control in the sibling relationship: mediators of the association between maternal psychological control and adolescents' emotional adjustment.

PubMed

Campione-Barr, Nicole; Lindell, Anna K; Greer, Kelly Bassett; Rose, Amanda J

2014-08-01

The association between mothers' psychological control and their children's emotional adjustment problems is well documented. However, processes that may explain this association are not well understood. The present study tested the idea that relational aggression and psychological control within the context of the sibling relationship may help to account for the relation between mothers' psychological control and adolescents' internalizing symptoms. Older (M = 16.46, SD = 1.35 years) and younger (M = 13.67, SD = 1.56 years) siblings from 101 dyads rated the psychological control they received from mothers and siblings, and the relational aggression they received from siblings. Despite some similarities between psychological control and relational aggression, confirmatory factor analyses provided evidence that the two sibling processes are distinct. Maternal psychological control was related to psychological control and relational aggression within the sibling relationship, which were related to adolescents' anxiety and depressed mood. In addition, sibling relational aggression was a more powerful mediator of the relationship between maternal psychological control and adolescent adjustment than sibling psychological control.

Commognitive analysis of undergraduate mathematics students' first encounter with the subgroup test

NASA Astrophysics Data System (ADS)

Ioannou, Marios

2018-06-01

This study analyses learning aspects of undergraduate mathematics students' first encounter with the subgroup test, using the commognitive theoretical framework. It focuses on students' difficulties as these are related to the object-level and metalevel mathematical learning in group theory, and, when possible, highlights any commognitive conflicts. In the data analysis, one can identify three types of difficulties, relevant to object-level learning: namely regarding the frequently observed confusion between groups and sets, the object-level rules of visual mediators, and the object-level rules of contextual notions, such as permutations, exponentials, sets and matrices. In addition, data analysis suggests two types of difficulties, relevant to metalevel learning. The first refers to the actual proof that the three conditions of subgroup test hold, and the second is related to syntactic inaccuracies, incomplete argumentation and problematic use of visual mediators. Finally, this study suggests that there are clear links between object-level and metalevel learning, mainly due to the fact that objectification of the various relevant mathematical notions influences the endorsement of the governing metarules.

Does playing pay? The fitness-effect of free play during childhood.

PubMed

Greve, Werner; Thomsen, Tamara; Dehio, Cornelia

2014-04-29

Evolutionary developmental psychology claims that the sequences and processes of human development, in fact the mere fact of ontogeny itself, have to be viewed as evolutionary products. However, although the functional benefits of childish behavior (child playing) for cognitive and emotional development have been shown repeatedly, claiming evolutionary adaptiveness of playing in childhood suggests that childish play supports evolutionary success in mature stages of development. This hypothesis is tested in a study with N=134 adults (93 females; age range 20-66 years). Participants were asked to recollect their play experiences during childhood in detail, and to report their current developmental status with respect to several aspects of social success. Results show that the opportunity for and the promotion of free play in childhood significantly predict some indicators of social success. Additional analyses strive to explore mediating processes for this relationship. In particular, the mediating role of individual adaptivity (flexibility of goal adjustment) is investigated. Results suggest that freely playing in childhood promotes developmental resources, in particular individual adaptivity in adulthood, which, in turn, promote developmental success.

Impact of high-performance work systems on individual- and branch-level performance: test of a multilevel model of intermediate linkages.

PubMed

Aryee, Samuel; Walumbwa, Fred O; Seidu, Emmanuel Y M; Otaye, Lilian E

2012-03-01

We proposed and tested a multilevel model, underpinned by empowerment theory, that examines the processes linking high-performance work systems (HPWS) and performance outcomes at the individual and organizational levels of analyses. Data were obtained from 37 branches of 2 banking institutions in Ghana. Results of hierarchical regression analysis revealed that branch-level HPWS relates to empowerment climate. Additionally, results of hierarchical linear modeling that examined the hypothesized cross-level relationships revealed 3 salient findings. First, experienced HPWS and empowerment climate partially mediate the influence of branch-level HPWS on psychological empowerment. Second, psychological empowerment partially mediates the influence of empowerment climate and experienced HPWS on service performance. Third, service orientation moderates the psychological empowerment-service performance relationship such that the relationship is stronger for those high rather than low in service orientation. Last, ordinary least squares regression results revealed that branch-level HPWS influences branch-level market performance through cross-level and individual-level influences on service performance that emerges at the branch level as aggregated service performance.

Role of hypoxia-inducible factor-{alpha} in hepatitis-B-virus X protein-mediated MDR1 activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Hyo-Kyung; Han, Chang Yeob; Cheon, Eun-Pa

2007-06-01

The transition from chemotherapy-responsive cancer cells to chemotherapy-resistant cancer cells is mainly accompanied by the increased expression of multi-drug resistance 1 (MDR1). We found that hepatitis-B-virus X protein (HBx) increases the transcriptional activity and protein level of MDR1 in a hepatoma cell line, H4IIE. In addition, HBx overexpression made H4IIE cells more resistant to verapamil-uptake. HBx stabilized hypoxia-inducible factor-1{alpha} (HIF-1{alpha}) and induced the nuclear translocation of C/EBP{beta}. Reporter gene analyses showed that HBx increased the reporter activity in the cells transfected with the reporter containing MDR1 gene promoter. Moreover, the luciferase reporter gene activity was significantly inhibited by HIF-1{alpha} siRNAmore » but not by overexpression of C/EBP dominant negative mutant. These results imply that HBx increases the MDR1 transporter activity through the transcriptional activation of the MDR1 gene with HIF-1{alpha} activation, and suggest HIF-1{alpha} for the therapeutic target of HBV-mediated chemoresistance.« less

Hydrogen-Bond and Supramolecular-Contact Mediated Fluorescence Enhancement of Electrochromic Azomethines.

PubMed

Wałęsa-Chorab, Monika; Tremblay, Marie-Hélène; Skene, William G

2016-08-01

An electronic push-pull fluorophore consisting of an intrinsically fluorescent central fluorene capped with two diaminophenyl groups was prepared. An aminothiophene was conjugated to the two flanking diphenylamines through a fluorescent quenching azomethine bond. X-ray crystallographic analysis confirmed that the fluorophore formed multiple intermolecular supramolecular bonds. It formed two hydrogen bonds involving a terminal amine, resulting in an antiparallel supramolecular dimer. Hydrogen bonding was also confirmed by FTIR and NMR spectroscopic analyses, and further validated theoretically by DFT calculations. Intrinsic fluorescence quenching modes could be reduced by intermolecular supramolecular contacts. These contacts could be engaged at high concentrations and in thin films, resulting in fluorescence enhancement. The fluorescence of the fluorophore could also be restored to an intensity similar to its azomethine-free counterpart with the addition of water in >50 % v/v in tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), and acetonitrile. The fluorophore also exhibited reversible oxidation and its color could be switched between yellow and blue when oxidized. Reversible electrochemically mediated fluorescence turn-off on turn-on was also possible. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The discursive self-construction of suicidal help seekers in computer-mediated discourse.

PubMed

Kupferberg, Irit; Gilat, Izhak

2012-01-01

The study focuses on the discursive self-construction of suicidal help seekers in an open computer-mediated forum for mental help. Our theoretical framework is inspired by a functionalist approach to discourse, which emphasizes that language resources are self-displaying. It also espouses discursive psychology, which prioritizes the study of psychological and social phenomena in discursive processes. In addition, we adopt the Four World Approach to the analysis of positioning. Qualitative and quantitative analyses show that the density of 'irrealis' (i.e. negation, future and wishes) units and figurative forms was significantly higher in the suicidal messages compared with the messages of other troubled selves, who produced more 'realis' units (i.e. specific and generic stories) and information questions. We interpret these findings as showing that in their attempt to conceptualize conflict and pain, suicidal help-seekers shied away from the narration of past experience and focused instead on the construction of death. The other troubled help seekers used realis units and questions in order to describe their experience to guarantee that help would be provided.

Phage-induced lysis enhances biofilm formation in Shewanella oneidensis MR-1

PubMed Central

Gödeke, Julia; Paul, Kristina; Lassak, Jürgen; Thormann, Kai M

2011-01-01

Shewanella oneidensis MR-1 is capable of forming highly structured surface-attached communities. By DNase I treatment, we demonstrated that extracellular DNA (eDNA) serves as a structural component in all stages of biofilm formation under static and hydrodynamic conditions. We determined whether eDNA is released through cell lysis mediated by the three prophages LambdaSo, MuSo1 and MuSo2 that are harbored in the genome of S. oneidensis MR-1. Mutant analyses and infection studies revealed that all three prophages may individually lead to cell lysis. However, only LambdaSo and MuSo2 form infectious phage particles. Phage release and cell lysis already occur during early stages of static incubation. A mutant devoid of the prophages was significantly less prone to lysis in pure culture. In addition, the phage-less mutant was severely impaired in biofilm formation through all stages of development, and three-dimensional growth occurred independently of eDNA as a structural component. Thus, we suggest that in S. oneidensis MR-1 prophage-mediated lysis results in the release of crucial biofilm-promoting factors, in particular eDNA. PMID:20962878

Global analysis of gene expression reveals mRNA superinduction is required for the inducible immune response to a bacterial pathogen

PubMed Central

Barry, Kevin C; Ingolia, Nicholas T; Vance, Russell E

2017-01-01

The inducible innate immune response to infection requires a concerted process of gene expression that is regulated at multiple levels. Most global analyses of the innate immune response have focused on transcription induced by defined immunostimulatory ligands, such as lipopolysaccharide. However, the response to pathogens involves additional complexity, as pathogens interfere with virtually every step of gene expression. How cells respond to pathogen-mediated disruption of gene expression to nevertheless initiate protective responses remains unclear. We previously discovered that a pathogen-mediated blockade of host protein synthesis provokes the production of specific pro-inflammatory cytokines. It remains unclear how these cytokines are produced despite the global pathogen-induced block of translation. We addressed this question by using parallel RNAseq and ribosome profiling to characterize the response of macrophages to infection with the intracellular bacterial pathogen Legionella pneumophila. Our results reveal that mRNA superinduction is required for the inducible immune response to a bacterial pathogen. DOI: http://dx.doi.org/10.7554/eLife.22707.001 PMID:28383283

Interparental Conflict Relative to Suicidal Ideation in Chinese Adolescents: The Roles of Coping Strategies and Meaning in Life

PubMed Central

Zhang, Rongwei; Li, Dan; Chen, Fei; Ewalds-Kvist, Béatrice M.; Liu, Shihong

2017-01-01

The aim of this study was to explore the paths between interparental conflict and Chinese adolescents’ suicidal ideation. Altogether 931 adolescents (Mage = 17.84, SD = 0.77, females = 531) completed the Dyadic Consensus Scale, Self-Report Coping Scale, Meaning in Life Questionnaire, and Positive and Negative Suicide Ideation questionnaires. Mediation analyses were conducted, focusing on the relations between interparental conflict and suicidal ideation along with coping styles and a sense of meaning in life. The results showed that interparental conflict indirectly predicted adolescents’ suicidal ideation via three mediators: coping-approach strategies, presence of meaning, and the joint serial effects of coping-approach strategies and presence of meaning in Chinese adolescents. In addition, boys were more likely to be at risk for suicidal ideation than girls, so were 10th graders compared to 11th graders. These findings supported a combined distress-to-meaninglessness line of thinking along with the use of coping-approach strategies to depress self-harm ideation. Generally, interparental conflict should be kept out of youngsters’ immediate vicinity as a preventive measure of suicidal ideation. PMID:28690561

Perceived Social Support Mediating the Relationship between Perceived Stress and Job Satisfaction

ERIC Educational Resources Information Center

Sultan, Sarwat; Rashid, Safia

2015-01-01

This research was conducted to examine the mediating effect of perceived social support between perceived stress and job satisfaction among employees. A conveniently selected sample of 280 employees provided the information on Perceived Social Support Scale, Perceived Stress Scale, and Job Satisfaction Survey. Employing Regression analyses,…

Mediation of Changes in Anxiety and Depression During Treatment of Social Phobia

ERIC Educational Resources Information Center

Moscovitch, David A.; Stefan G. Hofmann, Michael K.; Suvak, Michael K.; In-Albon, Tina

2005-01-01

To investigate the interactive process of changes in social anxiety and depression during treatment, the authors assessed weekly symptoms in 66 adult outpatients with social phobia (social anxiety disorder) who participated in cognitive- behavioral group therapy. Multilevel mediational analyses revealed that improvements in social anxiety mediated…

Alternative High School Students' Physical Activity: Role of Self-Efficacy

ERIC Educational Resources Information Center

Kenyon, Denyelle Baete; Kubik, Martha Y.; Davey, Cynthia; Sirard, John; Fulkerson, Jayne A.

2012-01-01

Objective: To examine physical activity self-efficacy as a mediator of the association between perceived barriers to PA and moderate-to-vigorous physical activity (MVPA) among alternative high school (AHS) students. Methods: Students (N = 145) from 6 AHS completed self-report questionnaires. Results: Mediation analyses revealed partial mediation…

The relationship between internalized stigma, negative symptoms and social functioning in schizophrenia: the mediating role of self-efficacy.

PubMed

Hill, Kimberley; Startup, Mike

2013-04-30

The broad aim of the present study was to gain a greater understanding of the processes that contribute to negative symptoms and social functioning in schizophrenia. More specifically, a theoretical model was proposed predicting that self-efficacy would mediate the relationship between internalized stigma and both negative symptoms and social functioning in schizophrenia. Initial analyses revealed that all variables were correlated. Specifically, internalized stigma was strongly correlated with negative symptoms, social functioning and self-efficacy. Furthermore, self-efficacy was strongly related to negative symptoms and moderately associated with social functioning. Further analyses however did not support the mediational role of self-efficacy. The theoretical and clinical implications of the findings, together with recommendations for future research, are outlined. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Identifying cis-mediators for trans-eQTLs across many human tissues using genomic mediation analysis

PubMed Central

Yang, Fan; Wang, Jiebiao; Pierce, Brandon L.; Chen, Lin S.

2017-01-01

The impact of inherited genetic variation on gene expression in humans is well-established. The majority of known expression quantitative trait loci (eQTLs) impact expression of local genes (cis-eQTLs). More research is needed to identify effects of genetic variation on distant genes (trans-eQTLs) and understand their biological mechanisms. One common trans-eQTLs mechanism is “mediation” by a local (cis) transcript. Thus, mediation analysis can be applied to genome-wide SNP and expression data in order to identify transcripts that are “cis-mediators” of trans-eQTLs, including those “cis-hubs” involved in regulation of many trans-genes. Identifying such mediators helps us understand regulatory networks and suggests biological mechanisms underlying trans-eQTLs, both of which are relevant for understanding susceptibility to complex diseases. The multitissue expression data from the Genotype-Tissue Expression (GTEx) program provides a unique opportunity to study cis-mediation across human tissue types. However, the presence of complex hidden confounding effects in biological systems can make mediation analyses challenging and prone to confounding bias, particularly when conducted among diverse samples. To address this problem, we propose a new method: Genomic Mediation analysis with Adaptive Confounding adjustment (GMAC). It enables the search of a very large pool of variables, and adaptively selects potential confounding variables for each mediation test. Analyses of simulated data and GTEx data demonstrate that the adaptive selection of confounders by GMAC improves the power and precision of mediation analysis. Application of GMAC to GTEx data provides new insights into the observed patterns of cis-hubs and trans-eQTL regulation across tissue types. PMID:29021290

Agrobacterium tumefaciens-mediated transformation of Mucor circinelloides.

PubMed

Nyilasi, I; Acs, K; Papp, T; Nagy, E; Vágvölgyi, C

2005-01-01

The Agrobacterium tumefaciens-mediated transformation of the zygomycetous fungus Mucor circinelloides is described. A method was also developed for the hygromycin B-based selection of Mucor transformants. Transformation with the hygromycin B phosphotransferase gene of Escherichia coli controlled by the heterologous Aspergillus nidulans trpC promoter resulted in hygromycin B-resistant clones. The presence of the hygromycin resistance gene in the genome of the transformants was verified by polymerase chain reaction and Southern hybridization: the latter analyses revealed integrations in the host genome at different sites in different transformants. The stability of transformants remained questionable during the latter analyses.

The associations of morningness-eveningness with anger and impulsivity in the general population.

PubMed

Hwang, Jeong Yeon; Kang, Seung-Gul; Gwak, Ah Reum; Park, Juhyun; Lee, Yu Jin

2016-01-01

The aim of this study was to investigate the relationships among morningness-eveningness, impulsivity and anger in the general population. A total of 1000 community-dwelling subjects (500 males) aged 20-77 years (mean± SD age: 39.6 ± 11.6 years) completed the morningness-eveningness questionnaire (MEQ), Barratt impulsiveness scale (BIS), Spielberger State-Trait Anger Expression Inventory (STAXI) and Center for Epidemiologic Studies Depression Scale. Moderation and mediation analyses were performed to determine whether the relationship between two variables depended on the third variable, referred to as a moderator, and whether the third variable, known as a mediator, was associated with the other two variables establishing causation. The MEQ scores exhibited significant negative associations with BIS (p < 0.001) and STAXI (p < 0.001) scores, and high scores on the BIS were associated with high scores on the STAXI (p < 0.001). Impulsivity, as measured by the BIS, played a role as a moderator (p < 0.001) in the relationship between MEQ and STAXI, and anger, as measured by the STAXI, acted as moderator (p = 0.030) in the association between MEQ and BIS. However, after controlling for the interaction of the BIS and MEQ, the MEQ scores did not significantly predict STAXI scores (p = 0.070). Additionally, the effect size of the mediating effect of the BIS scores on the relationship between the MEQ and STAXI (percent mediation: 53.2%) was larger than that of the STAXI scores on the association between the MEQ and BIS (percent mediation: 31.8%). The present results demonstrate that morningness-eveningness was closely related with both impulsivity and anger in the general population. Furthermore, these findings suggest that impulsivity may exercise a great influence on the association between morningness-eveningness and anger in two ways: as a moderator by modulating this relationship based on the level of impulsivity and as a mediator by acting as an intermediary factor.

Residential road traffic noise and general mental health in youth: The role of noise annoyance, neighborhood restorative quality, physical activity, and social cohesion as potential mediators.

PubMed

Dzhambov, Angel; Tilov, Boris; Markevych, Iana; Dimitrova, Donka

2017-12-01

Given the ubiquitous nature of both noise pollution and mental disorders, their alleged association has not escaped the spotlight of public health research. The effect of traffic noise on mental health is probably mediated by other factors, which have not been elucidated sufficiently. Herein, we aimed to disentangle the pathways linking road traffic noise to general mental health in Bulgarian youth, with a focus on several candidate mediators - noise annoyance, perceived restorative quality of the living environment, physical activity, and neighborhood social cohesion. A cross-sectional sample was collected in October - December 2016 in the city of Plovdiv, Bulgaria. It consisted of 399 students aged 15-25years, recruited from two high schools and three universities. Road traffic noise exposure (L den ) was derived from the strategic noise map of Plovdiv. Mental health was measured with the 12-item form of the General Health Questionnaire (GHQ-12). Noise annoyance, perceived restorative quality of the living environment, commuting and leisure time physical activity, and neighborhood social cohesion were assessed using validated questionnaires. Analyses were based on linear regression mediation models and a structural equation modeling (SEM) to account for the hypothesized interdependencies between candidate mediators. Results showed that higher noise exposure was associated with worse mental health only indirectly. More specifically, tests of the single and parallel mediation models indicated independent indirect paths through noise annoyance, social cohesion, and physical activity. In addition, the SEM revealed that more noise annoyance was associated with less social cohesion, and in turn with worse mental health; noise annoyance was also associated with lower neighborhood restorative quality, thereby with less social cohesion and physical activity, and in turn with worse mental health. However, causality could not be established. Further research is warranted to expand our still limited understanding of these person-environment interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proteomic Interaction Patterns between Human Cyclins, the Cyclin-Dependent Kinase Ortholog pUL97 and Additional Cytomegalovirus Proteins

PubMed Central

Steingruber, Mirjam; Kraut, Alexandra; Socher, Eileen; Sticht, Heinrich; Reichel, Anna; Stamminger, Thomas; Amin, Bushra; Couté, Yohann; Hutterer, Corina; Marschall, Manfred

2016-01-01

The human cytomegalovirus (HCMV)-encoded cyclin-dependent kinase (CDK) ortholog pUL97 associates with human cyclin B1 and other types of cyclins. Here, the question was addressed whether cyclin interaction of pUL97 and additional viral proteins is detectable by mass spectrometry-based approaches. Proteomic data were validated by coimmunoprecipitation (CoIP), Western blot, in vitro kinase and bioinformatic analyses. Our findings suggest that: (i) pUL97 shows differential affinities to human cyclins; (ii) pUL97 inhibitor maribavir (MBV) disrupts the interaction with cyclin B1, but not with other cyclin types; (iii) cyclin H is identified as a new high-affinity interactor of pUL97 in HCMV-infected cells; (iv) even more viral phosphoproteins, including all known substrates of pUL97, are detectable in the cyclin-associated complexes; and (v) a first functional validation of pUL97-cyclin B1 interaction, analyzed by in vitro kinase assay, points to a cyclin-mediated modulation of pUL97 substrate preference. In addition, our bioinformatic analyses suggest individual, cyclin-specific binding interfaces for pUL97-cyclin interaction, which could explain the different strengths of interactions and the selective inhibitory effect of MBV on pUL97-cyclin B1 interaction. Combined, the detection of cyclin-associated proteins in HCMV-infected cells suggests a complex pattern of substrate phosphorylation and a role of cyclins in the fine-modulation of pUL97 activities. PMID:27548200

[Family and school violence: the mediator role of self-esteem and attitudes towards institutional authority].

PubMed

Cava, María Jesús; Musitu, Gonzalo; Murgui, Sergio

2006-08-01

This study analyses the influence of family communication and parental valuation of school on adolescent violent behaviour at school. By means of a structural equation model, both its direct and indirect influence through school and family self-esteem of the adolescent and his attitude towards school authority are analysed. The sample is composed of 665 adolescents whose ages range from 12 to 16 years old. The results confirm the existence of an indirect relationship but not direct influence of the family on school violence. The attitude of the adolescent towards school authority is the mediator variable which shows the strongest direct effect on school violence. Also, the two dimensions of self-esteem considered are significant intermediate variables. These results and their implications are analysed.

Peer relationship and adolescent smartphone addiction: The mediating role of self-esteem and the moderating role of the need to belong.

PubMed

Wang, Pengcheng; Zhao, Meng; Wang, Xingchao; Xie, Xiaochun; Wang, Yuhui; Lei, Li

2017-12-01

Background and aims Adolescent smartphone addiction has received increased attention in recent years, and peer relationship has been found to be a protective factor in adolescent smartphone. However, little is known about the mediating and moderating mechanisms underlying this relation. The aim of this study was to investigate (a) the mediating role of self-esteem in the association between student-student relationship and smartphone addiction, and (b) the moderating role of the need to belong in the indirect relationship between student-student relationship and adolescent smartphone addiction. Methods This model was examined with 768 Chinese adolescents (mean age = 16.81 years, SD = 0.73); the participants completed measurements regarding student-student relationship, self-esteem, the need to belong, and smartphone addiction. Results The correlation analyses indicated that student-student relationship was significantly negatively associated with adolescent smartphone addiction, and the need to belong was significantly positively associated with adolescent smartphone addiction. Mediation analyses revealed that self-esteem partially mediated the link between student-student relationship and adolescent smartphone addiction. Moderated mediation further indicated that the mediated path was weaker for adolescents with lower levels of the need to belong. Discussion and conclusion High self-esteem could be a protective factor against smartphone addiction for adolescents with a strong need to belong as these students appeared to be at elevated risk of developing smartphone addiction.

Streetscape greenery and health: stress, social cohesion and physical activity as mediators.

PubMed

de Vries, Sjerp; van Dillen, Sonja M E; Groenewegen, Peter P; Spreeuwenberg, Peter

2013-10-01

Several studies have shown a positive relationship between local greenspace availability and residents' health, which may offer opportunities for health improvement. This study focuses on three mechanisms through which greenery might exert its positive effect on health: stress reduction, stimulating physical activity and facilitating social cohesion. Knowledge on mechanisms helps to identify which type of greenspace is most effective in generating health benefits. In eighty neighbourhoods in four Dutch cities data on quantity and quality of streetscape greenery were collected by observations. Data on self-reported health and proposed mediators were obtained for adults by mail questionnaires (N = 1641). Multilevel regression analyses, controlling for socio-demographic characteristics, revealed that both quantity and quality of streetscape greenery were related to perceived general health, acute health-related complaints, and mental health. Relationships were generally stronger for quality than for quantity. Stress and social cohesion were the strongest mediators. Total physical activity was not a mediator. Physical activity that could be undertaken in the public space (green activity) was, but less so than stress and social cohesion. With all three mediators included in the analysis, complete mediation could statistically be proven in five out of six cases. In these analyses the contribution of green activity was often not significant. The possibility that the effect of green activity is mediated by stress and social cohesion, rather than that it has a direct health effect, is discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mediators of effects of a selective family-focused violence prevention approach for middle school students.

PubMed

2012-02-01

This study examined how parenting and family characteristics targeted in a selective prevention program mediated effects on key youth proximal outcomes related to violence perpetration. The selective intervention was evaluated within the context of a multi-site trial involving random assignment of 37 schools to four conditions: a universal intervention composed of a student social-cognitive curriculum and teacher training, a selective family-focused intervention with a subset of high-risk students, a condition combining these two interventions, and a no-intervention control condition. Two cohorts of sixth-grade students (total N = 1,062) exhibiting high levels of aggression and social influence were the sample for this study. Analyses of pre-post change compared to controls using intent-to-treat analyses found no significant effects. However, estimates incorporating participation of those assigned to the intervention and predicted participation among those not assigned revealed significant positive effects on student aggression, use of aggressive strategies for conflict management, and parental estimation of student's valuing of achievement. Findings also indicated intervention effects on two targeted family processes: discipline practices and family cohesion. Mediation analyses found evidence that change in these processes mediated effects on some outcomes, notably aggressive behavior and valuing of school achievement. Results support the notion that changing parenting practices and the quality of family relationships can prevent the escalation in aggression and maintain positive school engagement for high-risk youth.

48 CFR 6101.54 - Alternative dispute resolution [Rule 54].

Code of Federal Regulations, 2010 CFR

2010-10-01

... as ADR Neutrals, most commonly use a combination of facilitative and evaluative mediation approaches...) Evaluative mediation. In addition to engaging in facilitative mediation, if authorized under the terms of the...

48 CFR 6101.54 - Alternative dispute resolution [Rule 54].

Code of Federal Regulations, 2012 CFR

2012-10-01

... as ADR Neutrals, most commonly use a combination of facilitative and evaluative mediation approaches...) Evaluative mediation. In addition to engaging in facilitative mediation, if authorized under the terms of the...

48 CFR 6101.54 - Alternative dispute resolution [Rule 54].

Code of Federal Regulations, 2014 CFR

2014-10-01

... as ADR Neutrals, most commonly use a combination of facilitative and evaluative mediation approaches...) Evaluative mediation. In addition to engaging in facilitative mediation, if authorized under the terms of the...

48 CFR 6101.54 - Alternative dispute resolution [Rule 54].

Code of Federal Regulations, 2011 CFR

2011-10-01

... as ADR Neutrals, most commonly use a combination of facilitative and evaluative mediation approaches...) Evaluative mediation. In addition to engaging in facilitative mediation, if authorized under the terms of the...

48 CFR 6101.54 - Alternative dispute resolution [Rule 54].

Code of Federal Regulations, 2013 CFR

2013-10-01

... as ADR Neutrals, most commonly use a combination of facilitative and evaluative mediation approaches...) Evaluative mediation. In addition to engaging in facilitative mediation, if authorized under the terms of the...

Sexual Victimization and Somatic Complaints in Pregnancy: Examination of Depression as a Mediator.

PubMed

Littleton, Heather

2015-01-01

Research suggests that women with histories of sexual victimization are more likely to experience somatic complaints in pregnancy. However, prior studies have been limited by homogenous samples, have primarily only examined the relationship of childhood sexual abuse (CSA) to somatic complaints, and have not examined potential mechanisms explaining this association. Thus, the current study examined the relationship between lifetime sexual victimization history and somatic complaints in pregnancy in an ethnically diverse sample of pregnant women. Additionally, depressive symptoms were examined as a mediator of the sexual victimization-somatic complaints relationship. Women were recruited from the waiting room of a university-affiliated obstetrics-gynecology clinic to complete a study of psychological health and negative sexual experiences. The 407 currently pregnant participants who completed measures of their sexual victimization history, depressive symptoms, and somatic complaints were primarily African American (53.6%), low to middle income (75.4%), and reported an unplanned pregnancy (72%). A total of 27.7% of women had a history of CSA and/or adolescent/adult sexual assault. Mediation analyses using bootstrapping supported depression as a significant mediator of the relationship between sexual victimization and somatic complaints, with a medium-sized effect (κ(2) = .09). Having a history of sexual victimization is associated with risk for poor mental and physical health during pregnancy. There are likely multiple mechanisms explaining the association between sexual victimization and somatic complaints in pregnancy, which should be investigated in future research. Copyright © 2015 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

FKBP5 DNA methylation does not mediate the association between childhood maltreatment and depression symptom severity in the Detroit Neighborhood Health Study.

PubMed

Bustamante, Angela C; Aiello, Allison E; Guffanti, Guia; Galea, Sandro; Wildman, Derek E; Uddin, Monica

2018-01-01

Exposure to childhood maltreatment increases the risk of developing mental illness later in life. Childhood maltreatment and depression have both been associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis-a key regulator of the body's stress response. Additionally, HPA axis dysregulation has been implicated in the etiology of a range of mental illnesses. A substantial body of work has shown history of childhood maltreatment alters DNA methylation levels within key HPA axis genes. We therefore investigated whether one of these key genes, FKBP5 mediates the relationship between childhood maltreatment and depression, and assessed FKBP5 DNA methylation and gene expression within 112 adults from the Detroit Neighborhood Health Study (DNHS). DNA methylation was assessed in 4 regions, including the upstream promoter, downstream promoter, and two glucocorticoid response elements (GREs) via pyrosequencing using whole blood derived DNA; Taqman assays measured relative RNA expression from leukocytes. Mediation analyses were conducted using sequential linear regression. Childhood maltreatment was significantly associated with depression symptom severity (FDR < 0.006), but was not a significant predictor of DNA methylation in any of the four loci examined. FKBP5 showed elevated expression levels in participants with vs. without a history of depression (p < 0.001); no significant difference in gene expression levels was observed in relation to childhood maltreatment (p > 0.05). Our results suggest DNA methylation does not mediate the childhood maltreatment-depression association in the DNHS. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Relationship Between Maternal Domestic Violence and Infant and Toddlers' Emotional Regulation: Highlighting the Need for Preventive Services.

PubMed

Geyer, Chelsea; Ogbonnaya, Ijeoma Nwabuzor

2017-11-01

In an effort to further understand the impact of domestic violence (DV) on infant and toddlers' development, this research utilized data from the second cohort of National Survey of Child and Adolescent Well-Being (NSCAW II) to examine the relationship between maternal DV and infant and toddlers' emotional regulation, and determine whether mothers' receipt of DV services mediated this relationship. The sample was limited to children aged 0 to 3 years and included (a) infants less than 1 year old ( n = 603), (b) infants 1 to less than 2 years old ( n = 310), and (c) toddlers 2 to 3 years old ( n = 268). Infant/toddlers' emotional regulation was measured using mothers' response on the How My Infant/Toddler/Child Usually Acts questionnaire. In addition, data were collected to assess whether (a) active DV was present during the time of the Child Protective Services (CPS) investigation and (b) mothers received DV services during the past year. Study research questions were examined using a series of multiple regression analyses. Mediation was tested based on Baron and Kenny's recommended model for establishing mediation. The mediational model was not found to be significant; however, a positive relationship existed between maternal DV and emotional regulation among infants aged less than 1 year old (β = 1.61, p = .039). There were no statistically significant relationships between DV and emotional regulation in the other age groups. These findings highlight the need to provide CPS-involved families victimized by DV with services that focus on preventing poor infant emotional regulation.

Recall of threat and submissiveness in childhood and psychopathology: the mediator effect of self-criticism.

PubMed

Castilho, Paula; Pinto-Gouveia, José; Amaral, Vânia; Duarte, Joana

2014-01-01

Research has robustly shown that early negative parenting experiences are associated with psychopathology and self-criticism in adulthood. This study investigates recall of personal feelings of perceived threat and subordination in childhood and its relation to psychopathology. In addition, we explore the mediator role of self-criticism in this association. A sample of 193 subjects from the general population completed self-report questionnaires measuring the study variables. The mediator analyses suggested that the impact of submissiveness experiences in childhood on depression and anxiety is mediated by self-criticism. Our findings highlight the route through which the recall of personal feelings of perceived involuntary subordination to parents contributes to depression and anxiety in adulthood. Although the relation between early experiences of abuse and later psychological problems is now well established, there has been less study on subtler forms of threat and subordinate behaviour in childhood. Given ours and previous findings, therapists should be aware of, and prone to explore, these early experiences. Most studies exploring early negative experiences mainly refer to attachment theory-related constructs (e.g., attachment style). We also highlight the importance of noting rank structure and rank style in the family. Self-criticism seems to be a key process in the relation between early aversive experiences of subordination and psychopathology. Given the idea that self-reassuring operates through a different affect system, helping people develop inner warmth and compassion for the self may be important to counteract feelings of self-hatred and self-attack. Copyright © 2012 John Wiley & Sons, Ltd.

Physical Fitness and Aortic Stiffness Explain the Reduced Cognitive Performance Associated with Increasing Age in Older People.

PubMed

Kennedy, Greg; Meyer, Denny; Hardman, Roy J; Macpherson, Helen; Scholey, Andrew B; Pipingas, Andrew

2018-01-01

Greater physical fitness is associated with reduced rates of cognitive decline in older people; however, the mechanisms by which this occurs are still unclear. One potential mechanism is aortic stiffness, with increased stiffness resulting in higher pulsatile pressures reaching the brain and possibly causing progressive micro-damage. There is limited evidence that those who regularly exercise may have lower aortic stiffness. To investigate whether greater fitness and lower aortic stiffness predict better cognitive performance in older people and, if so, whether aortic stiffness mediates the relationship between fitness and cognition. Residents of independent living facilities, aged 60-90, participated in the study (N = 102). Primary measures included a computerized cognitive assessment battery, pulse wave velocity analysis to measure aortic stiffness, and the Six-Minute Walk test to assess fitness. Based on hierarchical regression analyses, structural equation modelling was used to test the mediation hypothesis. Both fitness and aortic stiffness independently predicted Spatial Working Memory (SWM) performance, however no mediating relationship was found. Additionally, the derived structural equation model shows that, in conjunction with BMI and sex, fitness and aortic stiffness explain 33% of the overall variation in SWM, with age no longer directly predicting any variation. Greater fitness and lower aortic stiffness both independently predict better SWM in older people. The strong effect of age on cognitive performance is totally mediated by fitness and aortic stiffness. This suggests that addressing both physical fitness and aortic stiffness may be important to reduce the rate of age associated cognitive decline.

Subunit architecture and functional modular rearrangements of the transcriptional mediator complex.

PubMed

Tsai, Kuang-Lei; Tomomori-Sato, Chieri; Sato, Shigeo; Conaway, Ronald C; Conaway, Joan W; Asturias, Francisco J

2014-06-05

The multisubunit Mediator, comprising ∼30 distinct proteins, plays an essential role in gene expression regulation by acting as a bridge between DNA-binding transcription factors and the RNA polymerase II (RNAPII) transcription machinery. Efforts to uncover the Mediator mechanism have been hindered by a poor understanding of its structure, subunit organization, and conformational rearrangements. By overcoming biochemical and image analysis hurdles, we obtained accurate EM structures of yeast and human Mediators. Subunit localization experiments, docking of partial X-ray structures, and biochemical analyses resulted in comprehensive mapping of yeast Mediator subunits and a complete reinterpretation of our previous Mediator organization model. Large-scale Mediator rearrangements depend on changes at the interfaces between previously described Mediator modules, which appear to be facilitated by factors conducive to transcription initiation. Conservation across eukaryotes of Mediator structure, subunit organization, and RNA polymerase II interaction suggest conservation of fundamental aspects of the Mediator mechanism. Copyright © 2014 Elsevier Inc. All rights reserved.

Pleiotropic Meta-Analyses of Longitudinal Studies Discover Novel Genetic Variants Associated with Age-Related Diseases

PubMed Central

He, Liang; Kernogitski, Yelena; Kulminskaya, Irina; Loika, Yury; Arbeev, Konstantin G.; Loiko, Elena; Bagley, Olivia; Duan, Matt; Yashkin, Arseniy; Ukraintseva, Svetlana V.; Kovtun, Mikhail; Yashin, Anatoliy I.; Kulminski, Alexander M.

2016-01-01

Age-related diseases may result from shared biological mechanisms in intrinsic processes of aging. Genetic effects on age-related diseases are often modulated by environmental factors due to their little contribution to fitness or are mediated through certain endophenotypes. Identification of genetic variants with pleiotropic effects on both common complex diseases and endophenotypes may reveal potential conflicting evolutionary pressures and deliver new insights into shared genetic contribution to healthspan and lifespan. Here, we performed pleiotropic meta-analyses of genetic variants using five NIH-funded datasets by integrating univariate summary statistics for age-related diseases and endophenotypes. We investigated three groups of traits: (1) endophenotypes such as blood glucose, blood pressure, lipids, hematocrit, and body mass index, (2) time-to-event outcomes such as the age-at-onset of diabetes mellitus (DM), cancer, cardiovascular diseases (CVDs) and neurodegenerative diseases (NDs), and (3) both combined. In addition to replicating previous findings, we identify seven novel genome-wide significant loci (< 5e-08), out of which five are low-frequency variants. Specifically, from Group 2, we find rs7632505 on 3q21.1 in SEMA5B, rs460976 on 21q22.3 (1 kb from TMPRSS2) and rs12420422 on 11q24.1 predominantly associated with a variety of CVDs, rs4905014 in ITPK1 associated with stroke and heart failure, rs7081476 on 10p12.1 in ANKRD26 associated with multiple diseases including DM, CVDs, and NDs. From Group 3, we find rs8082812 on 18p11.22 and rs1869717 on 4q31.3 associated with both endophenotypes and CVDs. Our follow-up analyses show that rs7632505, rs4905014, and rs8082812 have age-dependent effects on coronary heart disease or stroke. Functional annotation suggests that most of these SNPs are within regulatory regions or DNase clusters and in linkage disequilibrium with expression quantitative trait loci, implying their potential regulatory influence on the expression of nearby genes. Our mediation analyses suggest that the effects of some SNPs are mediated by specific endophenotypes. In conclusion, these findings indicate that loci with pleiotropic effects on age-related disorders tend to be enriched in genes involved in underlying mechanisms potentially related to nervous, cardiovascular and immune system functions, stress resistance, inflammation, ion channels and hematopoiesis, supporting the hypothesis of shared pathological role of infection, and inflammation in chronic age-related diseases. PMID:27790247

High temporal resolution fluorescence measurements of a mitochondrial dye for detection of early stage apoptosis

PubMed Central

Iyer, Divya; Ray, Rachel D.; Pappas, Dimitri

2013-01-01

In the present study, early stage apoptosis is explored with high temporal resolution. In addition to monitoring early apoptosis induction in single cells by ultrasensitive confocal fluorescence microscopy (UCFM), the mitochondrial proteins release kinetics was explored. The current study shows development and optimization of a novel, rapid apoptosis assay to explore the earliest changes in cells by the intrinsic apoptosis pathway. We show that early apoptotic changes in the mitochondria begin nearly simultaneously with the addition of an apoptosis-inducing drug, such as staurosporine. With a temporal resolution of five minutes, this non-invasive analytical technique can elucidate the earliest apoptotic events in living cells. Moreover, our results show that the mitochondrial inter-membrane proteins are not involved in the extrinsic pathway of Ramos cells mediated by an anti-CD95 antibody. Additional techniques such as light microscopy and flow cytometry were employed to confirm the results obtained by ultrasensitive confocal fluorescence microscopy. The results of this study help to understand the earliest mechanisms of apoptosis induction in cells, enabling new methods of drug testing and dose-response analyses. PMID:23831722

Potential of mean force between like-charged nanoparticles: Many-body effect

NASA Astrophysics Data System (ADS)

Zhang, Xi; Zhang, Jin-Si; Shi, Ya-Zhou; Zhu, Xiao-Long; Tan, Zhi-Jie

2016-03-01

Ion-mediated interaction is important for the properties of polyelectrolytes such as colloids and nucleic acids. The effective pair interactions between two polyelectrolytes have been investigated extensively, but the many-body effect for multiple polyelectrolytes still remains elusive. In this work, the many-body effect in potential of mean force (PMF) between like-charged nanoparticles in various salt solutions has been comprehensively examined by Monte Carlo simulation and the nonlinear Poisson-Boltzmann theory. Our calculations show that, at high 1:1 salt, the PMF is weakly repulsive and appears additive, while at low 1:1 salt, the additive assumption overestimates the repulsive many-body PMF. At low 2:2 salt, the pair PMF appears weakly repulsive while the many-body PMF can become attractive. In contrast, at high 2:2 salt, the pair PMF is apparently attractive while the many-body effect can cause a weaker attractive PMF than that from the additive assumption. Our microscopic analyses suggest that the elusive many-body effect is attributed to ion-binding which is sensitive to ion concentration, ion valence, number of nanoparticles and charges on nanoparticles.

Associations between children's social functioning and physical activity participation are not mediated by social acceptance: a cross-sectional study.

PubMed

Sebire, Simon J; Jago, Russell; Fox, Kenneth R; Page, Angie S; Brockman, Rowan; Thompson, Janice L

2011-09-30

Physical activity (PA) during childhood often occurs in social contexts. As such, children's ability to develop and maintain friendship groups may be important in understanding their PA. This paper investigates the associations among children's social functioning, and physical activity and whether perceptions of social acceptance mediate any social functioning-PA association. A cross sectional survey in which 652 10-11 year olds self-reported their peer (e.g. difficulties with friends) and conduct (e.g. anger/aggression) problems, prosocial behaviours (e.g. being kind to others) and perceptions of social acceptance. Physical activity was objectively assessed by Actigraph GT1M accelerometers to estimate counts per minute, (CPM) and minutes of moderate-to-vigorous physical activity (MVPA). Linear regression analyses were conducted to investigate associations between social functioning and PA. Indirect effects were analysed to explore mediation by social acceptance. Among boys, peer problems were negatively associated with CPM and MVPA and conduct problems were positively associated with CPM and MVPA. Prosocial behaviour was unrelated to PA in boys. Social functioning was not associated with PA among girls. Social acceptance did not mediate the social functioning-PA relationship. Boys' conduct and peer problems were associated positively and negatively respectively with their PA but this relationship was not mediated by perceptions of social acceptance. Future research should study alternative mediators to understand the processes underpinning this relationship.

Cumulative Risk Exposure and Waist Circumference in Preschool-Aged Children: the Mediating Role of Television and Moderating Role of Sex.

PubMed

Grummon, Anna H; Vaughn, Amber; Jones, Deborah J; Ward, Dianne S

2017-08-01

Children exposed to multiple stressors are more likely to be overweight, but little is known about the mechanisms explaining this association. This cross-sectional study examined whether children exposed to multiple stressors had higher waist circumference, and whether this association was mediated through children's television time. Participants were 319 parent-child dyads. Children were 2-5 years old and had at least one overweight parent (BMI ≥ 25 kg/m 2 ). Data were collected at baseline of a larger childhood obesity prevention study and included information on psychosocial stressors (e.g., parenting stress), demographic stressors (e.g., low income), children's television time, and children's waist circumference. Two cumulative risk scores were created by summing stressors in each domain (demographic and psychosocial). Mediation and moderated mediation analyses were conducted. Indirect effects of both cumulative risk scores on waist circumference through television time were not significant; however, moderated mediation analyses found significant moderation by gender. The indirect effects of both risk scores on waist circumference through television time were significant and positive for girls, but near-zero for boys. Reducing television time should be explored as a strategy for buffering against the negative health effects of exposure to multiple stressors among girls. Longitudinal and intervention research is needed to confirm these results and to identify mediating factors between cumulative risk and body weight among boys.

Mediating effects of resistance training skill competency on health-related fitness and physical activity: the ATLAS cluster randomised controlled trial.

PubMed

Smith, Jordan J; Morgan, Philip J; Plotnikoff, Ronald C; Stodden, David F; Lubans, David R

2016-01-01

The purpose of this study was to examine the mediating effect of resistance training skill competency on percentage of body fat, muscular fitness and physical activity among a sample of adolescent boys participating in a school-based obesity prevention intervention. Participants were 361 adolescent boys taking part in the Active Teen Leaders Avoiding Screen-time (ATLAS) cluster randomised controlled trial: a school-based program targeting the health behaviours of economically disadvantaged adolescent males considered "at-risk" of obesity. Body fat percentage (bioelectrical impedance), muscular fitness (hand grip dynamometry and push-ups), physical activity (accelerometry) and resistance training skill competency were assessed at baseline and post-intervention (i.e., 8 months). Three separate multi-level mediation models were analysed to investigate the potential mediating effects of resistance training skill competency on each of the study outcomes using a product-of-coefficients test. Analyses followed the intention-to-treat principle. The intervention had a significant impact on the resistance training skill competency of the boys, and improvements in skill competency significantly mediated the effect of the intervention on percentage of body fat and the combined muscular fitness score. No significant mediated effects were found for physical activity. Improving resistance training skill competency may be an effective strategy for achieving improvements in body composition and muscular fitness in adolescent boys.

Estimating and testing mediation and moderation in within-subject designs.

PubMed

Judd, C M; Kenny, D A; McClelland, G H

2001-06-01

Analyses designed to detect mediation and moderation of treatment effects are increasingly prevalent in research in psychology. The mediation question concerns the processes that produce a treatment effect. The moderation question concerns factors that affect the magnitude of that effect. Although analytic procedures have been reasonably well worked out in the case in which the treatment varies between participants, no systematic procedures for examining mediation and moderation have been developed in the case in which the treatment varies within participants. The authors present an analytic approach to these issues using ordinary least squares estimation.

Within-subject mediation analysis for experimental data in cognitive psychology and neuroscience.

PubMed

Vuorre, Matti; Bolger, Niall

2017-12-15

Statistical mediation allows researchers to investigate potential causal effects of experimental manipulations through intervening variables. It is a powerful tool for assessing the presence and strength of postulated causal mechanisms. Although mediation is used in certain areas of psychology, it is rarely applied in cognitive psychology and neuroscience. One reason for the scarcity of applications is that these areas of psychology commonly employ within-subjects designs, and mediation models for within-subjects data are considerably more complicated than for between-subjects data. Here, we draw attention to the importance and ubiquity of mediational hypotheses in within-subjects designs, and we present a general and flexible software package for conducting Bayesian within-subjects mediation analyses in the R programming environment. We use experimental data from cognitive psychology to illustrate the benefits of within-subject mediation for theory testing and comparison.

Transformational Leadership and Organizational Citizenship Behavior: A Meta-Analytic Test of Underlying Mechanisms.

PubMed

Nohe, Christoph; Hertel, Guido

2017-01-01

Based on social exchange theory, we examined and contrasted attitudinal mediators (affective organizational commitment, job satisfaction) and relational mediators (trust in leader, leader-member exchange; LMX) of the positive relationship between transformational leadership and organizational citizenship behavior (OCB). Hypotheses were tested using meta-analytic path models with correlations from published meta-analyses (761 samples with 227,419 individuals overall). When testing single-mediator models, results supported our expectations that each of the mediators explained the relationship between transformational leadership and OCB. When testing a multi-mediator model, LMX was the strongest mediator. When testing a model with a latent attitudinal mechanism and a latent relational mechanism, the relational mechanism was the stronger mediator of the relationship between transformational leadership and OCB. Our findings help to better understand the underlying mechanisms of the relationship between transformational leadership and OCB.

Beyond total treatment effects in randomised controlled trials: Baseline measurement of intermediate outcomes needed to reduce confounding in mediation investigations.

PubMed

Landau, Sabine; Emsley, Richard; Dunn, Graham

2018-06-01

Random allocation avoids confounding bias when estimating the average treatment effect. For continuous outcomes measured at post-treatment as well as prior to randomisation (baseline), analyses based on (A) post-treatment outcome alone, (B) change scores over the treatment phase or (C) conditioning on baseline values (analysis of covariance) provide unbiased estimators of the average treatment effect. The decision to include baseline values of the clinical outcome in the analysis is based on precision arguments, with analysis of covariance known to be most precise. Investigators increasingly carry out explanatory analyses to decompose total treatment effects into components that are mediated by an intermediate continuous outcome and a non-mediated part. Traditional mediation analysis might be performed based on (A) post-treatment values of the intermediate and clinical outcomes alone, (B) respective change scores or (C) conditioning on baseline measures of both intermediate and clinical outcomes. Using causal diagrams and Monte Carlo simulation, we investigated the performance of the three competing mediation approaches. We considered a data generating model that included three possible confounding processes involving baseline variables: The first two processes modelled baseline measures of the clinical variable or the intermediate variable as common causes of post-treatment measures of these two variables. The third process allowed the two baseline variables themselves to be correlated due to past common causes. We compared the analysis models implied by the competing mediation approaches with this data generating model to hypothesise likely biases in estimators, and tested these in a simulation study. We applied the methods to a randomised trial of pragmatic rehabilitation in patients with chronic fatigue syndrome, which examined the role of limiting activities as a mediator. Estimates of causal mediation effects derived by approach (A) will be biased if one of the three processes involving baseline measures of intermediate or clinical outcomes is operating. Necessary assumptions for the change score approach (B) to provide unbiased estimates under either process include the independence of baseline measures and change scores of the intermediate variable. Finally, estimates provided by the analysis of covariance approach (C) were found to be unbiased under all the three processes considered here. When applied to the example, there was evidence of mediation under all methods but the estimate of the indirect effect depended on the approach used with the proportion mediated varying from 57% to 86%. Trialists planning mediation analyses should measure baseline values of putative mediators as well as of continuous clinical outcomes. An analysis of covariance approach is recommended to avoid potential biases due to confounding processes involving baseline measures of intermediate or clinical outcomes, and not simply for increased precision.

[Effects of nurses' perception of servant leadership on leader effectiveness, satisfaction and additional effort: focused on the mediating effects of leader trust and value congruence].

PubMed

Han, Sang Sook; Kim, Nam Eun

2012-02-01

This study was done to examine the effects of nurses' perception of servant leadership on leader effectiveness, satisfaction and promoting additional effort. The focus was the mediating effects of leader trust and value congruence. Data were collected from 361 RN-BSN students and nurses participating in nationally attended in-service training programs. Data were analyzed using descriptive statistics and structural analysis with SPSS 17.0 windows program and Amos 7.0. Direct effects of nurses' perception of servant leadership were negative, but mediating effects of trust and value congruency were positively correlated with leader effectiveness, satisfaction and additional effort, that is servant leadership should be effective through mediating factors. The study results indicate that if the middle managers of nurses can build leader trust and value congruency between nurses through servant leadership, leader effectiveness, satisfaction and additional effort on the part of the nurses could result in a positive change in the long term.

The Mediational Role of Coping Strategies in the Relationship Between Self-Esteem and Risk of Internet Addiction

PubMed Central

Servidio, Rocco; Gentile, Ambra; Boca, Stefano

2018-01-01

The aim of the present study is to explore, through a mediation model, the relationship among self-esteem, coping strategies, and the risk of Internet addiction in a sample of 300 Italian university students. We submitted the data to a descriptive, mediational comparison between variables (t-test), and correlational statistical analyses. The results confirmed the effect of self-esteem on the risk of Internet addiction. However, we found that the introduction of coping strategies as a mediator gives rise to partial mediation. A low level of self-esteem is a predictor of avoidance-oriented coping that, in turn, affects the risk of Internet addiction.

Self-regulatory processes mediate the intention-behavior relation for adherence and exercise behaviors.

PubMed

de Bruin, Marijn; Sheeran, Paschal; Kok, Gerjo; Hiemstra, Anneke; Prins, Jan M; Hospers, Harm J; van Breukelen, Gerard J P

2012-11-01

Understanding the gap between people's intentions and actual health behavior is an important issue in health psychology. Our aim in this study was to investigate whether self-regulatory processes (monitoring goal progress and responding to discrepancies) mediate the intention-behavior relation in relation to HIV medication adherence (Study 1) and intensive exercise behavior (Study 2). In Study 1, questionnaire and electronically monitored adherence data were collected at baseline and 3 months later from patients in the control arm of an HIV-adherence intervention study. In Study 2, questionnaire data was collected at 3 time points 6-weeks apart in a cohort study of physical activity. Complete data at all time points were obtained from 51 HIV-infected patients and 499 intensive exercise participants. Intentions were good predictors of behavior and explained 25 to 30% of the variance. Self-regulatory processes explained an additional 11% (Study 1) and 6% (Study 2) of variance in behavior on top of intentions. Regression and bootstrap analyses revealed at least partial, and possibly full, mediation of the intention-behavior relation by self-regulatory processes. The present studies indicate that self-regulatory processes may explain how intentions drive behavior. Future tests, using different health behaviors and experimental designs, could firmly establish whether self-regulatory processes complement current health behavior theories and should become routine targets for intervention. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Caenorhabditis elegans reveals a FxNPxY-independent low-density lipoprotein receptor internalization mechanism mediated by epsin1

PubMed Central

Kang, Yuan-Lin; Yochem, John; Bell, Leslie; Sorensen, Erika B.; Chen, Lihsia; Conner, Sean D.

2013-01-01

Low-density lipoprotein receptor (LDLR) internalization clears cholesterol-laden LDL particles from circulation in humans. Defects in clathrin-dependent LDLR endocytosis promote elevated serum cholesterol levels and can lead to atherosclerosis. However, our understanding of the mechanisms that control LDLR uptake remains incomplete. To identify factors critical to LDLR uptake, we pursued a genome-wide RNA interference screen using Caenorhabditis elegans LRP-1/megalin as a model for LDLR transport. In doing so, we discovered an unanticipated requirement for the clathrin-binding endocytic adaptor epsin1 in LDLR endocytosis. Epsin1 depletion reduced LDLR internalization rates in mammalian cells, similar to the reduction observed following clathrin depletion. Genetic and biochemical analyses of epsin in C. elegans and mammalian cells uncovered a requirement for the ubiquitin-interaction motif (UIM) as critical for receptor transport. As the epsin UIM promotes the internalization of some ubiquitinated receptors, we predicted LDLR ubiquitination as necessary for endocytosis. However, engineered ubiquitination-impaired LDLR mutants showed modest internalization defects that were further enhanced with epsin1 depletion, demonstrating epsin1-mediated LDLR endocytosis is independent of receptor ubiquitination. Finally, we provide evidence that epsin1-mediated LDLR uptake occurs independently of either of the two documented internalization motifs (FxNPxY or HIC) encoded within the LDLR cytoplasmic tail, indicating an additional internalization mechanism for LDLR. PMID:23242996

Fbw7 promotes ubiquitin-dependent degradation of c-Myb: involvement of GSK3-mediated phosphorylation of Thr-572 in mouse c-Myb.

PubMed

Kitagawa, K; Hiramatsu, Y; Uchida, C; Isobe, T; Hattori, T; Oda, T; Shibata, K; Nakamura, S; Kikuchi, A; Kitagawa, M

2009-06-25

Expression of oncoprotein c-Myb oscillates during hematopoiesis and hematological malignancies. Its quantity is not only regulated through transcriptional control but also through the ubiquitin-proteasome pathway, accompanied by phosphorylation, although the mechanisms are poorly understood. In this report, we tried to identify an E3 ubiquitin ligase, which targets c-Myb for ubiquitin-dependent degradation. We found that an F-box protein, Fbw7, interacted with c-Myb, which is mutated in numerous cancers. Fbw7 facilitated ubiquitylation and degradation of c-Myb in intact cells. Moreover, depletion of Fbw7 by RNA interference delayed turnover and increased the abundance of c-Myb in myeloid leukemia cells concomitantly, and suppressed the transcriptional level of gamma-globin, which receives transcriptional repression from c-Myb. In addition, we analysed sites required for both ubiquitylation and degradation of c-Myb. We found that Thr-572 is critical for Fbw7-mediated ubiquitylation in mouse c-Myb using site-directed mutagenesis. Fbw7 recognized the phosphorylation of Thr-572, which was mediated by glycogen synthase kinase 3 (GSK3). In consequence, the c-Myb protein was markedly stabilized by the substitution of Thr-572 to Ala. These observations suggest that SCF(Fbw7) ubiquitin ligase regulates phosphorylation-dependent degradation of c-Myb protein.

Psychosocial job characteristics and psychological distress / well-being: the mediating role of personal goal facilitation.

PubMed

Pisanti, Renato; van der Doef, Margot; Maes, Stan; Violani, Cristiano; Lazzari, David

2016-01-01

This study examined the mediating role of personal goal facilitation through work (PGFW), defined as perceptions of the extent to which one's job facilitates the attainment of one's personal goals, in the association between psychosocial job characteristics and psychological distress and job-related well-being. Questionnaire data from 217 nurses (84% female, with a mean age of 42.7 years, SD=7.2) were analyzed. Participants completed the following measures: the Leiden Quality of Work Questionnaire for Nurses, Workplace Goal Facilitation Inventory, Maslach Burnout Inventory-Human Services Survey, and Utrecht Work Engagement Scale (short version). A cross-sectional study design was applied. Hierarchical multiple regression analyses were conducted. The results indicated that unfavorable psychosocial job characteristics (high demands, low control, and low social support) were associated with lower PGFW. Furthermore, personal goal facilitation through work explained significant additional variance (from 2 to 11%) in psychological distress (somatic complaints and emotional exhaustion) and job-related well-being (personal accomplishment, job satisfaction, and work engagement), controlling for demographic indicators and psychosocial job characteristics. Finally, the results provided support for the mediating effects of PGFW between all psychosocial job characteristics and all outcomes, except in the case of depersonalization. This study suggests that hindered personal goal facilitation may be a mechanism through which psychosocial job characteristics have a negative impact on employees' well-being.

A review of pharmacogenetic studies of substance-related disorders*

PubMed Central

Jones, Jermaine D.; Comer, Sandra D.

2015-01-01

Background Substance-related disorders (SRDs) are a major cause of morbidity and mortality worldwide. Family, twin, and adoption studies have demonstrated the substantial heritability of SRDs. To determine the impact of genetic variation on risk for SRD and the response to treatment, researchers have conducted a number of secondary data analyses and quasi-experimental studies that target one or more candidate gene variants. Methods This review examines studies in which candidate polymorphisms were examined as mediator variables to identify pharmacogenetic effects on subjective responses to drug administration or cues or outcomes of medication trials for SRDs. Efforts to use a meta-analytic approach to quantify these effects are premature because the number of available studies using similar methods and outcomes is limited, so the present review is qualitative. Results Findings from these studies provide preliminary evidence of clinically relevant pharmacogenetic effects. However, independent replication of these findings has been sparse. Conclusions Although this growing body of literature has produced conflicting results, improved statistical controls may help to clarify the findings. Additionally, the use of empirically derived sub-phenotypes (i.e., which serve to differentiate distinct groups of affected individuals) may also help to identify genetic mediators of pharmacologic response in relation to SRDs. The identification of genetic mediators can inform clinical care both by identifying risk factors for SRDs and predicting adverse events and therapeutic outcomes associated with specific pharmacotherapies. PMID:25819021

Determination of the transforming activities of adenovirus oncogenes.

PubMed

Nevels, Michael; Dobner, Thomas

2007-01-01

The last 50 yr of molecular biological investigations into human adenoviruses (Ads) have contributed enormously to our understanding of the basic principles of normal and malignant cell growth. Much of this knowledge stems from analyses of the Ad productive infection cycle in permissive host cells. Also, initial observations concerning the transforming potential of human Ads subsequently revealed decisive insights into the molecular mechanisms of the origins of cancer and established Ads as a model system for explaining virus-mediated transformation processes. Today it is well established that cell transformation by human Ads is a multistep process involving several gene products encoded in early transcription units 1A (E1A) and 1B (E1B). Moreover, a large body of evidence now indicates that alternative or additional mechanisms are engaged in Ad-mediated oncogenic transformation involving gene products encoded in early region 4 (E4) as well as epigenetic changes resulting from viral DNA integration. In particular, studies on the transforming potential of several E4 gene products have now revealed new pathways that point to novel general mechanisms of virus-mediated oncogenesis. In this chapter we describe in vitro and in vivo assays to determine the transforming and oncogenic activities of the E1A, E1B, and E4 oncoproteins in primary baby rat kidney cells and athymic nude mice.

Cell transformation by human adenoviruses.

PubMed

Endter, C; Dobner, T

2004-01-01

The last 40 years of molecular biological investigations into human adenoviruses have contributed enormously to our understanding of the basic principles of normal and malignant cell growth. Much of this knowledge stems from analyses of their productive infection cycle in permissive host cells. Also, initial observations concerning the carcinogenic potential of human adenoviruses subsequently revealed decisive insights into the molecular mechanisms of the origins of cancer, and established adenoviruses as a model system for explaining virus-mediated transformation processes. Today it is well established that cell transformation by human adenoviruses is a multistep process involving several gene products encoded in early transcription units 1A (E1A) and 1B (E1B). Moreover, a large body of evidence now indicates that alternative or additional mechanisms are engaged in adenovirus-mediated oncogenic transformation involving gene products encoded in early region 4 (E4) as well as epigenetic changes resulting from viral DNA integration. In particular, detailed studies on the tumorigenic potential of subgroup D adenovirus type 9 (Ad9) E4 have now revealed a new pathway that points to a novel, general mechanism of virus-mediated oncogenesis. In this chapter, we summarize the current state of knowledge about the oncogenes and oncogene products of human adenoviruses, focusing particularly on recent findings concerning the transforming and oncogenic properties of viral proteins encoded in the E1B and E4 transcription units.

Determination of the transforming activities of adenovirus oncogenes.

PubMed

Speiseder, Thomas; Nevels, Michael; Dobner, Thomas

2014-01-01

The last 50 years of molecular biological investigations into human adenoviruses (Ads) have contributed enormously to our understanding of the basic principles of normal and malignant cell growth. Much of this knowledge stems from analyses of the Ad productive infection cycle in permissive host cells. Also, initial observations concerning the transforming potential of human Ads subsequently revealed decisive insights into the molecular mechanisms of the origins of cancer and established Ads as a model system for explaining virus-mediated transformation processes. Today it is well established that cell transformation by human Ads is a multistep process involving several gene products encoded in early transcription units 1A (E1A) and 1B (E1B). Moreover, a large body of evidence now indicates that alternative or additional mechanisms are engaged in Ad-mediated oncogenic transformation involving gene products encoded in early region 4 (E4) as well as epigenetic changes resulting from viral DNA integration. In particular, studies on the transforming potential of several E4 gene products have now revealed new pathways that point to novel general mechanisms of virus-mediated oncogenesis. In this chapter we describe in vitro and in vivo assays to determine the transforming and oncogenic activities of the E1A, E1B, and E4 oncoproteins in primary baby rat kidney cells, human amniotic fluid cells and athymic nude mice.

Social embeddedness as a mechanism for linking social cohesion to well-being among older adults: moderating effect of gender

PubMed Central

Momtaz, Yadollah Abolfathi; Haron, Sharifah Azizah; Ibrahim, Rahimah; Hamid, Tengku Aizan

2014-01-01

Background The positive effect of social cohesion on well-being in older adults has been well documented. However, relatively few studies have attempted to understand the mechanisms by which social cohesion influences well-being. The main aim of the current study is to identify social pathways in which social cohesion may contribute to well-being. Methods The data for this study (taken from 1,880 older adults, aged 60 years and older) were drawn from a national survey conducted during 2008–2009. The survey employed a two-stage stratified sampling process for data collection. Structural equation modeling was used to test mediating and moderating analyses. Results The proposed model documented a good fit to the data (GFI =98; CFI =0.99; RMSEA =0.04). The findings from bootstrap analysis and the Sobel test revealed that the impact of social cohesion on well-being is significantly mediated by social embeddedness (Z=5.62; P<0.001). Finally, the results of a multigroup analysis test showed that social cohesion influences well-being through the social embeddedness mechanism somewhat differently for older men than women. Conclusion The findings of this study, in addition to supporting the importance of neighborhood social cohesion for the well-being of older adults, also provide evidence that the impact of social cohesion towards well-being is mediated through the mechanism of social embeddedness. PMID:24904206

Social embeddedness as a mechanism for linking social cohesion to well-being among older adults: moderating effect of gender.

PubMed

Momtaz, Yadollah Abolfathi; Haron, Sharifah Azizah; Ibrahim, Rahimah; Hamid, Tengku Aizan

2014-01-01

The positive effect of social cohesion on well-being in older adults has been well documented. However, relatively few studies have attempted to understand the mechanisms by which social cohesion influences well-being. The main aim of the current study is to identify social pathways in which social cohesion may contribute to well-being. The data for this study (taken from 1,880 older adults, aged 60 years and older) were drawn from a national survey conducted during 2008-2009. The survey employed a two-stage stratified sampling process for data collection. Structural equation modeling was used to test mediating and moderating analyses. The proposed model documented a good fit to the data (GFI =98; CFI =0.99; RMSEA =0.04). The findings from bootstrap analysis and the Sobel test revealed that the impact of social cohesion on well-being is significantly mediated by social embeddedness (Z=5.62; P<0.001). Finally, the results of a multigroup analysis test showed that social cohesion influences well-being through the social embeddedness mechanism somewhat differently for older men than women. The findings of this study, in addition to supporting the importance of neighborhood social cohesion for the well-being of older adults, also provide evidence that the impact of social cohesion towards well-being is mediated through the mechanism of social embeddedness.

A review of pharmacogenetic studies of substance-related disorders.

PubMed

Jones, Jermaine D; Comer, Sandra D

2015-07-01

Substance-related disorders (SRDs) are a major cause of morbidity and mortality worldwide. Family, twin, and adoption studies have demonstrated the substantial heritability of SRDs. To determine the impact of genetic variation on risk for SRD and the response to treatment, researchers have conducted a number of secondary data analyses and quasi-experimental studies that target one or more candidate gene variants. This review examines studies in which candidate polymorphisms were examined as mediator variables to identify pharmacogenetic effects on subjective responses to drug administration or cues or outcomes of medication trials for SRDs. Efforts to use a meta-analytic approach to quantify these effects are premature because the number of available studies using similar methods and outcomes is limited, so the present review is qualitative. Findings from these studies provide preliminary evidence of clinically relevant pharmacogenetic effects. However, independent replication of these findings has been sparse. Although this growing body of literature has produced conflicting results, improved statistical controls may help to clarify the findings. Additionally, the use of empirically derived sub-phenotypes (i.e., which serve to differentiate distinct groups of affected individuals) may also help to identify genetic mediators of pharmacologic response in relation to SRDs. The identification of genetic mediators can inform clinical care both by identifying risk factors for SRDs and predicting adverse events and therapeutic outcomes associated with specific pharmacotherapies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Ama1p-activated anaphase-promoting complex regulates the destruction of Cdc20p during meiosis II

PubMed Central

Tan, Grace S.; Magurno, Jennifer; Cooper, Katrina F.

2011-01-01

The execution of meiotic divisions in Saccharomyces cerevisiae is regulated by anaphase-promoting complex/cyclosome (APC/C)–mediated protein degradation. During meiosis, the APC/C is activated by association with Cdc20p or the meiosis-specific activator Ama1p. We present evidence that, as cells exit from meiosis II, APC/CAma1 mediates Cdc20p destruction. APC/CAma1 recognizes two degrons on Cdc20p, the destruction box and destruction degron, with either domain being sufficient to mediate Cdc20p destruction. Cdc20p does not need to associate with the APC/C to bind Ama1p or be destroyed. Coimmunoprecipitation analyses showed that the diverged amino-terminal region of Ama1p recognizes both Cdc20p and Clb1p, a previously identified substrate of APC/CAma1. Domain swap experiments revealed that the C-terminal WD region of Cdh1p, when fused to the N-terminal region of Ama1p, could direct most of Ama1p functions, although at a reduced level. In addition, this fusion protein cannot complement the spore wall defect in ama1Δ strains, indicating that substrate specificity is also derived from the WD repeat domain. These findings provide a mechanism to temporally down-regulate APC/CCdc20 activity as the cells complete meiosis II and form spores. PMID:21118994

Does parental mediation of media influence child outcomes? A meta-analysis on media time, aggression, substance use, and sexual behavior.

PubMed

Collier, Kevin M; Coyne, Sarah M; Rasmussen, Eric E; Hawkins, Alan J; Padilla-Walker, Laura M; Erickson, Sage E; Memmott-Elison, Madison K

2016-05-01

The current study examined how parental mediation of media (restrictive mediation, active mediation, and coviewing) influenced child outcomes. Three meta-analyses, 1 for each type of mediation, were conducted on a total of 57 studies. Each analysis assessed the effectiveness of parental mediation on 4 pertinent child outcomes: media use, aggression, substance use, and sexual behavior. The overall results indicated small, but significant relationships between child outcomes and restrictive mediation (r+ = -.06), and coviewing (r+ = .09). Overall active mediation was nonsignificant, though active mediation was individually related to lower levels of aggression (r+ = -.08), sexual behavior (r+ = -.06), and substance use (r+ = -.11). This analysis revealed that parents may have the ability to mitigate some of the adverse effects of the media by using certain mediation strategies. Overall, a cooperative effort from the communication and parenting fields is necessary for a comprehensive analysis of parental mediation as well as a disentanglement of the various parental mediation measures. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

White matter microstructural variability mediates the relation between obesity and cognition in healthy adults.

PubMed

Zhang, Rui; Beyer, Frauke; Lampe, Leonie; Luck, Tobias; Riedel-Heller, Steffi G; Loeffler, Markus; Schroeter, Matthias L; Stumvoll, Michael; Villringer, Arno; Witte, A Veronica

2018-05-15

Obesity has been linked with structural and functional brain changes. However, the impact of obesity on brain and cognition in aging remains debatable, especially for white matter. We therefore aimed to determine the effects of obesity on white matter microstructure and potential implications for cognition in a well-characterized large cohort of healthy adults. In total, 1255 participants (50% females, 19-80 years, BMI 16.8-50.2 kg/m 2 ) with diffusion-weighted magnetic resonance imaging at 3T were analysed. Tract-based spatial statistics (TBSS) probed whether body mass index (BMI) and waist-to-hip ratio (WHR) were related to fractional anisotropy (FA). We conducted partial correlations and mediation analyses to explore whether obesity or regional FA were related to cognitive performance. Analyses were adjusted for demographic, genetic, and obesity-associated confounders. Results showed that higher BMI and higher WHR were associated with lower FA in multiple white matter tracts (p < 0.05, FWE-corrected). Mediation analyses provided evidence for indirect negative effects of higher BMI and higher WHR on executive functions and processing speed through lower FA in fiber tracts connecting (pre)frontal, visual, and associative areas (indirect paths, |ß| ≥ 0.01; 99% |CI| > 0). This large cross-sectional study showed that obesity is correlated with lower FA in multiple white matter tracts in otherwise healthy adults, independent of confounders. Moreover, although effect sizes were small, mediation results indicated that visceral obesity was linked to poorer executive functions and lower processing speed through lower FA in callosal and associative fiber tracts. Longitudinal studies are needed to support this hypothesis. Copyright © 2018 Elsevier Inc. All rights reserved.

"Small Talk Is Not Cheap": Phatic Computer-Mediated Communication in Intercultural Classes

ERIC Educational Resources Information Center

Maíz-Arévalo, Carmen

2017-01-01

The present study aims to analyse the phatic exchanges performed by a class of nine intercultural Master's students during a collaborative assignment which demanded online discussion using English as a lingua franca (ELF). Prior studies on the use of phatic communication in computer-mediated communication have concentrated on social networking…

Proteomic Analyses of Cellular Events Mediating/Inhibiting Chemical-Induced Injury

DTIC Science & Technology

2009-07-21

cells in patients with sarcoidosis , an innammatory disease which is onen located in the lungs [27,28J. Cell signaling in the NRF-2 Mediated Oxidative...bronchoalveolar lavage cells in sarcoidosis . J Clin Invest 2007, 117:3576-3582. 28. Yang Y, Fujita J, Bandoh 5, Ohtsuki Y, Yamadori I, Yoshinouchi T

Negative Opinion of Company Environment Mediates Career Choice of Accountancy Students

ERIC Educational Resources Information Center

Tong, David Yoon Kin; Tong, Xue Fa

2012-01-01

Purpose: The purpose of this paper is to explore accountancy students' pre-employment decisions as regards pursuing a career after completing an internship. The paper aims to analyse the mediating effect of aspects of students' training experience in firms as direct/indirect factors which influence their career decisions.…

Speaking to Read: Meta-Analysis of Peer-Mediated Learning for English Language Learners

ERIC Educational Resources Information Center

Cole, Mikel W.

2014-01-01

This meta-analysis examines the effectiveness of a group of instructional approaches (i.e., cooperative, collaborative, and peer tutoring) at improving literacy outcomes for English language learners. Main effects analyses of a sample of 28 experimental and quasi-experimental studies reveal that peer-mediation is more effective for ELLs than…

Lifelong Learning in Artistic Context Mediated by Advanced Technologies

ERIC Educational Resources Information Center

Ferrari, Mirella

2016-01-01

This research starts by analysing the current state of artistic heritage in Italy and studying some examples in Europe: we try to investigate the scope of non-formal learning in artistic context, mediated by advanced technology. The framework within which we have placed our investigation is that of lifelong learning and lifedeep learning. The…

When Mothers Have Serious Mental Health Problems: Parenting as a Proximal Mediator

ERIC Educational Resources Information Center

Oyserman, D.; Bybee, D.; Mowbray, C.; Hart-Johnson, T.

2005-01-01

Maternal mental health (MMH) problems are associated with lack of confidence in one's parenting, overly lax or too harsh discipline, and child academic underperformance. We asked if parenting mediates the effect of MMH problems on academic outcomes even among mothers with serious mental illness (n=164). Structural equation analyses show a…

Mediation Analysis in a Latent Growth Curve Modeling Framework

ERIC Educational Resources Information Center

von Soest, Tilmann; Hagtvet, Knut A.

2011-01-01

This article presents several longitudinal mediation models in the framework of latent growth curve modeling and provides a detailed account of how such models can be constructed. Logical and statistical challenges that might arise when such analyses are conducted are also discussed. Specifically, we discuss how the initial status (intercept) and…

Prospective Teachers' Future Time Perspective and Professional Plans about Teaching: The Mediating Role of Academic Optimism

ERIC Educational Resources Information Center

Eren, Altay

2012-01-01

This study aimed to examine the mediating role of prospective teachers' academic optimism in the relationship between their future time perspective and professional plans about teaching. A total of 396 prospective teachers voluntarily participated in the study. Correlation, regression, and structural equation modeling analyses were conducted in…

Business cycles, hypertension and cardiovascular disease: evidence from the Icelandic economic collapse.

PubMed

Asgeirsdottir, Tinna Laufey; Olafsdottir, Thorhildur; Ragnarsdottir, Dagny Osk

2014-08-01

Business cycles affect people's lives. A growing literature examines their effect on health outcomes. The available studies on the relationship between ambient economic conditions and cardiovascular health show mixed results. They are furthermore limited in their outcome measures, focusing mostly on mortality. We examined the relationship between economic conditions and cardiovascular disease and hypertension, using the Icelandic economic collapse of 2008. Logit regression analyses are used to examine the relationship between economic conditions and the probability of reporting a cardiovascular disease or hypertension. We furthermore investigated potential mediators of this relationship. The data used come from a health and lifestyle survey carried out by the Public Health Institute of Iceland in 2007 and 2009. The crisis was positively related to hypertension in males but no statistically significant relationship was found for females. The mediation analyses indicated partial mediation through changes in working hours and stress level, but negligible mediation through changes in income. The male hypertension was, however, suppressed by concurrent changes in smoking and body weight. Only examining mortality effects of society-wide economic conditions may understate the overall effect on cardiovascular health.

Serum magnesium and the risk of prediabetes: a population-based cohort study.

PubMed

Kieboom, Brenda C T; Ligthart, Symen; Dehghan, Abbas; Kurstjens, Steef; de Baaij, Jeroen H F; Franco, Oscar H; Hofman, Albert; Zietse, Robert; Stricker, Bruno H; Hoorn, Ewout J

2017-05-01

Previous studies have found an association between serum magnesium and incident diabetes; however, this association may be due to reverse causation, whereby diabetes may induce urinary magnesium loss. In contrast, in prediabetes (defined as impaired fasting glucose), serum glucose levels are below the threshold for urinary magnesium wasting and, hence, unlikely to influence serum magnesium levels. Thus, to study the directionality of the association between serum magnesium levels and diabetes, we investigated its association with prediabetes. We also investigated whether magnesium-regulating genes influence diabetes risk through serum magnesium levels. Additionally, we quantified the effect of insulin resistance in the association between serum magnesium levels and diabetes risk. Within the population-based Rotterdam Study, we used Cox models, adjusted for age, sex, lifestyle factors, comorbidities, kidney function, serum levels of electrolytes and diuretic use, to study the association between serum magnesium and prediabetes/diabetes. In addition, we performed two mediation analyses: (1) to study if common genetic variation in eight magnesium-regulating genes influence diabetes risk through serum magnesium levels; and (2) to quantify the proportion of the effect of serum magnesium levels on diabetes that is mediated through insulin resistance (quantified by HOMA-IR). A total of 8555 participants (mean age, 64.7 years; median follow-up, 5.7 years) with normal glucose levels (mean ± SD: 5.46 ± 0.58 mmol/l) at baseline were included. A 0.1 mmol/l decrease in serum magnesium level was associated with an increase in diabetes risk (HR 1.18 [95% CI 1.04, 1.33]), confirming findings from previous studies. Of interest, a similar association was found between serum magnesium levels and prediabetes risk (HR 1.12 [95% CI 1.01, 1.25]). Genetic variation in CLDN19, CNNM2, FXYD2, SLC41A2, and TRPM6 significantly influenced diabetes risk (p < 0.05), and for CNNM2, FXYD2, SLC41A2 and TRPM6 this risk was completely mediated by serum magnesium levels. We found that 29.1% of the effect of serum magnesium levels on diabetes was mediated through insulin resistance, whereas for prediabetes 13.4% was mediated through insulin resistance. Low serum magnesium levels are associated with an increased risk of prediabetes and this increased risk is similar to that of diabetes. Furthermore, common variants in magnesium-regulating genes modify diabetes risk through serum magnesium levels. Both findings support a potential causal role of magnesium in the development of diabetes, where the hypothesised pathway is partly mediated through insulin resistance.

Episodic feeling-of-knowing accuracy and cued recall in the elderly: evidence for double dissociation involving executive functioning and processing speed.

PubMed

Perrotin, Audrey; Isingrini, Michel; Souchay, Céline; Clarys, David; Taconnat, Laurence

2006-05-01

This research investigated adult age differences in a metamemory monitoring task-episodic feeling-of-knowing (FOK) and in an episodic memory task-cued recall. Executive functioning and processing speed were examined as mediators of these age differences. Young and elderly adults were administered an episodic FOK task, a cued recall task, executive tests and speed tests. Age-related decline was observed on all the measures. Correlation analyses revealed a pattern of double dissociation which indicates a specific relationship between executive score and FOK accuracy, and between speed score and cued recall. When executive functioning and processing speed were evaluated concurrently on FOK and cued recall variables, hierarchical regression analyses showed that executive score was a better mediator of age-related variance in FOK, and that speed score was the better mediator of age-related variance in cued recall.

Client Predictors of Short-term Psychotherapy Outcomes among Asian and White American Outpatients

PubMed Central

Kim, Jin E.; Zane, Nolan W.; Blozis, Shelley A.

2015-01-01

Purpose To examine predictors of psychotherapy outcomes, focusing on client characteristics that are especially salient for culturally diverse clients. Method Sixty clients (31 women; 27 White Americans, 33 Asian Americans) participated in this treatment study. Client characteristics were measured at pre-treatment, and outcomes were measured post-fourth session via therapist ratings of functioning and symptomatology. Regression analyses were utilized to test for predictors of outcomes, and bootstrap analyses were utilized to test for mediators. Results Higher levels of somatic symptoms predicted lower psychosocial functioning at post-treatment. Avoidant coping style predicted more negative symptoms and more psychological discomfort. Non-English language preference predicted worse outcomes; this effect was mediated by an avoidant coping style. Conclusions Language preference, avoidant coping style, and somatic symptoms predicted treatment outcome in a culturally diverse sample. Findings suggest that race/ethnicity-related variables may function through mediating proximal variables to affect outcomes. PMID:22836681

Why are hyperactivity and academic achievement related?

PubMed

Saudino, Kimberly J; Plomin, Robert

2007-01-01

Although a negative association between hyperactivity and academic achievement is well documented, little is known about the genetic and/or environmental mechanisms responsible for the association. The present study explored links between parent and teacher ratings of hyperactive behavior problems and teacher-assessed achievement in a sample of 1,876 twin pairs (mean age 7.04 years). The results did not differ across rater, nor were there significant differences between males or females or for twins in the same or different classrooms. Hyperactivity was significantly correlated with achievement. Multivariate model-fitting analyses revealed significant genetic and nonshared environmental covariance between the two phenotypes. In addition, bivariate heritabilities were substantial, indicating that the phenotypic correlations between hyperactivity and achievement were largely mediated by genetic influences.

Loneliness and sleep quality: dyadic effects and stress effects.

PubMed

Segrin, Chris; Burke, Tricia J

2015-01-01

The aims of this investigation are to determine whether loneliness is associated with a person's own sleep quality and sleep quality of their partner, and to test stress as a potential mediator. Participants were 255 couples in married (75%) or cohabiting relationships who completed self-report measures of loneliness, sleep quality, stress, and depression. Results of Actor-Partner Interdependence analyses replicated findings in the literature showing an association between loneliness and poor sleep quality. The more lonely a male participant was, the lower his partner's sleep quality. In addition, the more lonely participants were, the higher they rated their partner's sleep disturbance. There were significant indirect effects of loneliness on poor sleep quality through increased stress, even after controlling for depression.

Social integration and the mental health of Black adolescents

PubMed Central

Rose, Theda; Joe, Sean; Shields, Joseph; Caldwell, Cleopatra Howard

2014-01-01

The influence of family, school, and religious social contexts on the mental health of Black adolescents has been understudied. This study used Durkheim’s Social Integration Theory to examine these associations in a nationally representative sample of 1,170 Black adolescents, ages 13-17. Mental health was represented by positive and negative psychosocial well-being indicators. Results showed that adolescents’ integration into family and school were related to better mental health. Additionally, commitment to religious involvement positively influenced mental health. Although the direct effect of religious involvement was inversely related to mental health, mediation analyses revealed a positive influence through religious commitment. Findings suggest a greater emphasis on all three social contexts when designing strategies to improve the mental health of Black adolescents. PMID:24815855

Proteome Analyses of Staphylococcus aureus Biofilm at Elevated Levels of NaCl

PubMed Central

Islam, Nazrul; Ross, Julia M; Marten, Mark R

2016-01-01

Our studies demonstrate that sodium chloride (NaCl) induces changes in biofilm, mediated by increased production of polysaccharides intercellular adhesion (PIA). We identified 12 proteins that showed higher abundance in increased level of NaCl. This includes one important protein (IsaA) known to be associated with biofilm stability. In addition, we also found higher abundance of a cold shock protein, CspA, at higher NaCl. We have also identified several other proteins that are differentially expressed to the elevated levels of NaCl and mapped them in the regulatory pathways of PIA. The majority of proteins are involved with various aspects bacterial metabolic function. Our results demonstrated that NaCl influences gene regulatory networks controlling exopolysaccharide expression. PMID:26973848

About the dark and bright sides of self-efficacy: workaholism and work engagement.

PubMed

Del Líbano, Mario; Llorens, Susana; Salanoval, Marisa; Schaufeli, Wilmar B

2012-07-01

Taking the Resources-Experiences-Demands Model (RED Model) by Salanova and colleagues as our starting point, we tested how work self-efficacy relates positively to negative (i.e., work overload and work-family conflict) and positive outcomes (i.e., job satisfaction and organizational commitment), through the mediating role of workaholism (health impairment process) and work engagement (motivational process). In a sample of 386 administrative staff from a Spanish University (65% women), Structural Equation Modeling provided full evidence for the research model. In addition, Multivariate Analyses of Variance showed that self-efficacy was only related positively to one of the two dimensions of workaholism, namely, working excessively. Finally, we discuss the theoretical and practical contributions in terms of the RED Model.

Interventional Effects for Mediation Analysis with Multiple Mediators.

PubMed

Vansteelandt, Stijn; Daniel, Rhian M

2017-03-01

The mediation formula for the identification of natural (in)direct effects has facilitated mediation analyses that better respect the nature of the data, with greater consideration of the need for confounding control. The default assumptions on which it relies are strong, however. In particular, they are known to be violated when confounders of the mediator-outcome association are affected by the exposure. This complicates extensions of counterfactual-based mediation analysis to settings that involve repeatedly measured mediators, or multiple correlated mediators. VanderWeele, Vansteelandt, and Robins introduced so-called interventional (in)direct effects. These can be identified under much weaker conditions than natural (in)direct effects, but have the drawback of not adding up to the total effect. In this article, we adapt their proposal to achieve an exact decomposition of the total effect, and extend it to the multiple mediator setting. Interestingly, the proposed effects capture the path-specific effects of an exposure on an outcome that are mediated by distinct mediators, even when-as often-the structural dependence between the multiple mediators is unknown, for instance, when the direction of the causal effects between the mediators is unknown, or there may be unmeasured common causes of the mediators.

Increases in soil aggregation following phosphorus additions in a tropical premontane forest are not driven by root and arbuscular mycorrhizal fungal abundances

NASA Astrophysics Data System (ADS)

Camenzind, Tessa; Papathanasiou, Helena; Foerster, Antje; Dietrich, Karla; Hertel, Dietrich; Homeier, Juergen; Oelmann, Yvonne; Olsson, Pål Axel; Suárez, Juan; Rillig, Matthias

2015-12-01

Tropical ecosystems have an important role in global change scenarios, in part because they serve as a large terrestrial carbon pool. Carbon protection is mediated by soil aggregation processes, whereby biotic and abiotic factors influence the formation and stability of aggregates. Nutrient additions may affect soil structure indirectly by simultaneous shifts in biotic factors, mainly roots and fungal hyphae, but also via impacts on abiotic soil properties. Here, we tested the hypothesis that soil aggregation will be affected by nutrient additions primarily via changes in arbuscular mycorrhizal fungal (AMF) hyphae and root length in a pristine tropical forest system. Therefore, the percentage of water-stable macroaggregates (> 250µm) (WSA) and the soil mean weight diameter (MWD) was analyzed, as well as nutrient contents, pH, root length and AMF abundance. Phosphorus additions significantly increased the amount of WSA, which was consistent across two different sampling times. Despite a positive effect of phosphorus additions on extraradical AMF biomass, no relationship between WSA and extra-radical AMF nor roots was revealed by regression analyses, contrary to the proposed hypothesis. These findings emphasize the importance of analyzing soil structure in understudied tropical systems, since it might be affected by increasing nutrient deposition expected in the future.

Degradation mechanisms of DDX induced by the addition of toluene and glycerol as cosubstrates in a zero-valent iron pretreated soil.

PubMed

Velasco, Antonio; Aburto-Medina, Arturo; Shahsavari, Esmaeil; Revah, Sergio; Ortiz, Irmene

2017-01-05

Abiotic and biotic processes can be used to remediate DDX (DDT, DDD, DDE, and DDNS) contaminated soils; these processes can be fostered using specific carbon-amendments to stimulate particular soil indigenous microbial communities to improve rates or extent of degradation. In this study, toluene and glycerol were evaluated as cosubstrates under aerobic and anoxic conditions to determine the degradation efficiencies of DDX and to elucidate possible degradation mechanisms. Slurry microcosms experiments were performed during 60 days using pretreated soil with zero-valent iron (ZVI). Toluene addition enhanced the percentage of degradation of DDX. DDNS was the main compound degraded (around 86%) under aerobic conditions, suggesting cometabolic degradation of DDX by toluene-degrading soil bacteria. Glycerol addition under anoxic conditions favored the abiotic degradation of DDX mediated by sulfate-reducing bacteria activity, where DDT was the main compound degraded (around 90%). The 16S rDNA metagenomic analyses revealed Rhodococcus ruber and Desulfosporosinus auripigmenti as the predominant bacterial species after 40 days of treatment with toluene and glycerol additions, respectively. This study provides evidence of biotic and abiotic DDX degradation by the addition of toluene and glycerol as cosubstrates in ZVI pretreated DDX-contaminated soil. Copyright © 2016 Elsevier B.V. All rights reserved.

Pain and symptoms of depression in older adults living in community and in nursing homes: the role of activity restriction as a potential mediator and moderator.

PubMed

López-Lopez, Almudena; González, José L; Alonso-Fernández, Miriam; Cuidad, Noelia; Matías, Borja

2014-10-01

Chronic pain is likely to lead to depressive symptoms, but the nature of this relationship is not completely clear. The aim of the present study is to analyze the role of activity restriction in the pain-depression relationship in older people, and to test the hypothesis that this role is more relevant in community-dwelling older people than in nursing home residents. Depressive symptoms, pain intensity, and activity restriction were measured in a sample of 208 older adults with osteoarthritis, 102 living in nursing homes (NH), and 106 in the community. Analyses were carried out using moderation and moderated mediation analyses approach, treating activity restriction as a confounder. RESULTS showed a significant confounding effect of activity restriction, interaction effect between pain intensity and activity restriction on depression, and modifying effect of pain intensity on depression by adding activity restriction into the model. These results suggest a potential mediating and moderating effects of activity restriction. Moreover, analyses suggest that, surprisingly, the strength of the mediation could be higher in nursing homes. Overall, it may be that what is really important to emotional well-being is not so much pain itself, but rather the way in which the pain alters older people's lives. The greater strength of the mediation in NH might be understood within the scope of self-determination theory. Generally speaking, the NH context has been considered as a coercive setting, promoting non-autonomous orientation. In this context, when events are objectively coercive, people may lack perceived autonomy and hence be at greater risk of depression.

[Parents' and Children's Perspectives of Parental Mediation Strategies in Association with Children's Internet Skills].

PubMed

Glüer, Michael; Lohaus, Arnold

2018-02-01

Parents' and Children's Perspectives of Parental Mediation Strategies in Association with Children's Internet Skills The purpose of this study was to examine the association of parental mediation strategies (from parents' and children's perspective) and children's internet skills. In total 194 parent-child dyads were questioned about their parent's mediation strategies. The children (fifth to ninth grade) additionally answered questions about their internet skills and the amount of time they spent daily on the internet. Parents' and children's ratings of the parental mediation strategies showed moderate associations. Parents reported to use more often mediation strategies than was perceived by their children. The mediation strategies had only limited value for the prediction of the children's internet skills. Parents' and children's perspective about restrictive content mediation were both negatively associated to children's internet skills. After controlling for children's age, sex and time spent daily on the internet, results showed that only congruencies between children's and parental perspectives regarding the parental restrictive content mediation were associated with decreased technical and social internet skills. Additionally, discrepancies between the children's and parental perspectives regarding the parental use of technical mediation were associated with decreased technical internet skills. Discrepancies regarding the parental mediation strategy monitoring were related to increased information navigation skills.

Causal relationship between the AHSG gene and BMD through fetuin-A and BMI: multiple mediation analysis.

PubMed

Sritara, C; Thakkinstian, A; Ongphiphadhanakul, B; Chailurkit, L; Chanprasertyothin, S; Ratanachaiwong, W; Vathesatogkit, P; Sritara, P

2014-05-01

Using mediation analysis, a causal relationship between the AHSG gene and bone mineral density (BMD) through fetuin-A and body mass index (BMI) mediators was suggested. Fetuin-A, a multifunctional protein of hepatic origin, is associated with bone mineral density. It is unclear if this association is causal. This study aimed at clarification of this issue. A cross-sectional study was conducted among 1,741 healthy workers from the Electricity Generating Authority of Thailand (EGAT) cohort. The alpha-2-Heremans-Schmid glycoprotein (AHSG) rs2248690 gene was genotyped. Three mediation models were constructed using seemingly unrelated regression analysis. First, the ln[fetuin-A] group was regressed on the AHSG gene. Second, the BMI group was regressed on the AHSG gene and the ln[fetuin-A] group. Finally, the BMD model was constructed by fitting BMD on two mediators (ln[fetuin-A] and BMI) and the independent AHSG variable. All three analyses were adjusted for confounders. The prevalence of the minor T allele for the AHSG locus was 15.2%. The AHSG locus was highly related to serum fetuin-A levels (P < 0.001). Multiple mediation analyses showed that AHSG was significantly associated with BMD through the ln[fetuin-A] and BMI pathway, with beta coefficients of 0.0060 (95% CI 0.0038, 0.0083) and 0.0030 (95% CI 0.0020, 0.0045) at the total hip and lumbar spine, respectively. About 27.3 and 26.0% of total genetic effects on hip and spine BMD, respectively, were explained by the mediation effects of fetuin-A and BMI. Our study suggested evidence of a causal relationship between the AHSG gene and BMD through fetuin-A and BMI mediators.

Mechanisms of change underlying the efficacy of cognitive behaviour therapy for chronic fatigue syndrome in a specialist clinic: a mediation analysis.

PubMed

Stahl, D; Rimes, K A; Chalder, T

2014-04-01

Several randomized controlled trials (RCTs) have shown that cognitive behavioural psychotherapy (CBT) is an efficacious treatment for chronic fatigue syndrome (CFS). However, little is known about the mechanisms by which the treatment has its effect. The aim of this study was to investigate potential mechanisms of change underlying the efficacy of CBT for CFS. We applied path analysis and introduce novel model comparison approaches to assess a theoretical CBT model that suggests that fearful cognitions will mediate the relationship between avoidance behaviour and illness outcomes (fatigue and social adjustment). Data from 389 patients with CFS who received CBT in a specialist service in the UK were collected at baseline, at discharge from treatment, and at 3-, 6- and 12-month follow-ups. Path analyses were used to assess possible mediating effects. Model selection using information criteria was used to compare support for competing mediational models. Path analyses were consistent with the hypothesized model in which fear avoidance beliefs at the 3-month follow-up partially mediate the relationship between avoidance behaviour at discharge and fatigue and social adjustment respectively at 6 months. The results strengthen the validity of a theoretical model of CBT by confirming the role of cognitive and behavioural factors in CFS.

Multiple dimensions of spirituality in recovery: a lagged mediational analysis of Alcoholics Anonymous' principal theoretical mechanism of behavior change.

PubMed

Krentzman, Amy R; Cranford, James A; Robinson, Elizabeth A R

2013-01-01

Alcoholics Anonymous (AA) states that recovery is possible through spiritual experiences and spiritual awakenings. Research examining spirituality as a mediator of AA's effect on drinking has been mixed. It is unknown whether such findings are due to variations in the operationalization of key constructs, such as AA and spirituality. To answer these questions, the authors used a longitudinal model to test 2 dimensions of AA as focal predictors and 6 dimensions of spirituality as possible mediators of AA's association with drinking. Data from the first 18 months of a 3-year longitudinal study of 364 alcohol-dependent individuals were analyzed. Structural equation modeling was used to replicate the analyses of Kelly et al. (Alcohol Clin Exp Res. 2011;35:454-463) and to compare AA attendance and AA involvement as focal predictors. Multiple regression analyses were used to determine which spirituality dimensions changed as the result of AA participation. A trimmed, data-driven model was employed to test multiple mediation paths simultaneously. The findings of the Kelly et al. study were replicated. AA involvement was a stronger predictor of drinking outcomes than AA attendance. AA involvement predicted increases in private religious practices, daily spiritual experiences, and forgiveness of others. However, only private religious practices mediated the relationship between AA and drinking.

Does competence mediate the associations between puberty and internalizing or externalizing problems in adolescent girls?

PubMed

Negriff, Sonya; Hillman, Jennifer B; Dorn, Lorah D

2011-10-01

To examine separate mediational models linking (a) menarcheal status or (b) pubertal timing to internalizing and externalizing problems through competence. This study involved cross-sectional analyses of 262 adolescent girls (age: 11-17 years; mean = 14.93, standard deviation = 2.17) enrolled in a longitudinal study examining the association of psychological functioning and smoking with reproductive and bone health. Measures of menarcheal status (pre/post), pubertal timing (early, on-time, or late), internalizing and externalizing behavior, and perceived competence (parent and adolescent report) were obtained. Structural equation modeling was used for analyses. Perceived competence was found to fully mediate the association between menarcheal status and parent report of internalizing and externalizing problems. For adolescent report, there was a full mediation effect for internalizing problems but a partial mediation effect for externalizing problems. Being menarcheal was related to lower competence, which was in turn related to higher internalizing and externalizing problems. Models including pubertal timing were not significant. Perceived competence is important in understanding the associations between menarcheal status and internalizing and externalizing problems. Interventions targeting competence, particularly in postmenarcheal girls, may reduce or prevent problem behaviors. Copyright © 2011 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Impostor feelings as a moderator and mediator of the relationship between perceived discrimination and mental health among racial/ethnic minority college students.

PubMed

Cokley, Kevin; Smith, Leann; Bernard, Donte; Hurst, Ashley; Jackson, Stacey; Stone, Steven; Awosogba, Olufunke; Saucer, Chastity; Bailey, Marlon; Roberts, Davia

2017-03-01

This study investigated whether impostor feelings would both moderate and mediate the relationship between perceived discrimination and mental health in a sample of diverse ethnic minority college students (106 African Americans, 102 Asian Americans, 108 Latino/a Americans) at an urban public university. African American students reported higher perceived discrimination than Asian American and Latino/a American students, while no racial/ethnic group differences were reported for impostor feelings. Analyses revealed that among African American students, high levels of impostor feelings moderated the perceived discrimination and depression relationship and mediated the perceived discrimination and anxiety relationship. Among Asian American students, impostor feelings mediated the relationship between perceived discrimination and both depression and anxiety. Among Latino/a American students low levels of impostor feelings moderated the relationship between perceived discrimination and both depression and anxiety, and partially mediated the relationship between perceived discrimination and anxiety. Multigroup path analyses revealed a significantly stronger impact of impostor feelings on depression among African American students and a stronger impact of perceived discrimination on impostor feelings among African American and Latino/a American students. Clinical implications and future research directions are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Garrison's model of self-directed learning: preliminary validation and relationship to academic achievement.

PubMed

Abd-El-Fattah, Sabry M

2010-11-01

In this project, 119 undergraduates responded to a questionnaire tapping three psychological constructs implicated in Garrison's model of self-directed learning: self-management, self-monitoring, and motivation. Mediation analyses showed that these psychological constructs are interrelated and that motivation mediates the relationship between self-management and self-monitoring. Path modeling analyses revealed that self-management and self-monitoring significantly predicted academic achievement over two semesters with self-management being the strongest predictor. Motivation significantly predicted academic achievement over the second semester only. Implications of these findings for self-directed learning and academic achievement in a traditional classroom setting are discussed.

Fungal-mediated mortality explains the different effects of dung leachates on the germination response of grazing increaser and decreaser species

NASA Astrophysics Data System (ADS)

Carmona, Carlos P.; Navarro, Elena; Peco, Begoña

2016-01-01

Depending on their response to grazing, grassland species can be categorized as grazing increasers or decreasers. Grazing by livestock includes several different activities that can impact species differently. Recent evidence suggest that one of these actions, dung deposition, can reduce the germinative performance of decreaser species, thus favouring increasers. The present study tested the hypothesis that decreased germinative success of decreaser species is caused by a greater activity of fungal pathogens under the influence of dung leachates. We performed a phytotron experiment analysing the germination and fungal infections of fourteen species from Mediterranean grasslands. Species were grouped into phylogenetically-related pairs, composed of an increaser and a decreaser species. Seeds of each species were germinated under four different treatments (control, dung leachate addition, fungicide addition and dung leachate and fungicide addition), and the differences in germination percentage, germination speed and infection rate between each increaser species and its decreaser counterpart were analysed. Decreaser species were more affected by mortality than increaser ones, and these differences were higher under the presence of dung leachates. The differences in germinative performance after excluding the effect of seed mortality did not differ between treatments, showing that the main mechanism by which dung leachates favour increaser species is through increased mortality of the seeds of decreaser species. Drastic reductions in the number of dead seeds in the treatments including fungicide addition further revealed that fungal pathogens are responsible for these differences between species with different grazing response. The different vulnerabilities of increaser and decreaser species to the increased activity of fungal pathogens under the presence of dung leachates seems the main reason behind the differential effect of these leachates on species with different grazing response.

Women, Physical Activity, and Quality of Life: Self-concept as a Mediator.

PubMed

Gonzalo Silvestre, Tamara; Ubillos Landa, Silvia

2016-02-22

The objectives of this research are: (a) analyze the incremental validity of physical activity's (PA) influence on perceived quality of life (PQL); (b) determine if PA's predictive power is mediated by self-concept; and (c) study if results vary according to a unidimensional or multidimensional approach to self-concept measurement. The sample comprised 160 women from Burgos, Spain aged 18 to 45 years old. Non-probability sampling was used. Two three-step hierarchical regression analyses were applied to forecast PQL. The hedonic quality-of-life indicators, self-concept, self-esteem, and PA were included as independent variables. The first regression analysis included global self-concept as predictor variable, while the second included its five dimensions. Two mediation analyses were conducted to see if PA's ability to predict PQL was mediated by global and physical self-concept. Results from the first regression shows that self-concept, satisfaction with life, and PA were significant predictors. PA slightly but significantly increased explained variance in PQL (2.1%). In the second regression, substituting global self-concept with its five constituent factors, only the physical dimension and satisfaction with life predicted PQL, while PA ceased to be a significant predictor. Mediation analysis revealed that only physical self-concept mediates the relationship between PA and PQL (z = 1.97, p < .050), and not global self-concept. Physical self-concept was the strongest predictor and approximately 32.45 % of PA's effect on PQL was mediated by it. This study's findings support a multidimensional view of self-concept, and represent a more accurate image of the relationship between PQL, PA, and self-concept.

Network analyses based on comprehensive molecular interaction maps reveal robust control structures in yeast stress response pathways

PubMed Central

Kawakami, Eiryo; Singh, Vivek K; Matsubara, Kazuko; Ishii, Takashi; Matsuoka, Yukiko; Hase, Takeshi; Kulkarni, Priya; Siddiqui, Kenaz; Kodilkar, Janhavi; Danve, Nitisha; Subramanian, Indhupriya; Katoh, Manami; Shimizu-Yoshida, Yuki; Ghosh, Samik; Jere, Abhay; Kitano, Hiroaki

2016-01-01

Cellular stress responses require exquisite coordination between intracellular signaling molecules to integrate multiple stimuli and actuate specific cellular behaviors. Deciphering the web of complex interactions underlying stress responses is a key challenge in understanding robust biological systems and has the potential to lead to the discovery of targeted therapeutics for diseases triggered by dysregulation of stress response pathways. We constructed large-scale molecular interaction maps of six major stress response pathways in Saccharomyces cerevisiae (baker’s or budding yeast). Biological findings from over 900 publications were converted into standardized graphical formats and integrated into a common framework. The maps are posted at http://www.yeast-maps.org/yeast-stress-response/ for browse and curation by the research community. On the basis of these maps, we undertook systematic analyses to unravel the underlying architecture of the networks. A series of network analyses revealed that yeast stress response pathways are organized in bow–tie structures, which have been proposed as universal sub-systems for robust biological regulation. Furthermore, we demonstrated a potential role for complexes in stabilizing the conserved core molecules of bow–tie structures. Specifically, complex-mediated reversible reactions, identified by network motif analyses, appeared to have an important role in buffering the concentration and activity of these core molecules. We propose complex-mediated reactions as a key mechanism mediating robust regulation of the yeast stress response. Thus, our comprehensive molecular interaction maps provide not only an integrated knowledge base, but also a platform for systematic network analyses to elucidate the underlying architecture in complex biological systems. PMID:28725465

Transformational Leadership and Organizational Citizenship Behavior: A Meta-Analytic Test of Underlying Mechanisms

PubMed Central

Nohe, Christoph; Hertel, Guido

2017-01-01

Based on social exchange theory, we examined and contrasted attitudinal mediators (affective organizational commitment, job satisfaction) and relational mediators (trust in leader, leader-member exchange; LMX) of the positive relationship between transformational leadership and organizational citizenship behavior (OCB). Hypotheses were tested using meta-analytic path models with correlations from published meta-analyses (761 samples with 227,419 individuals overall). When testing single-mediator models, results supported our expectations that each of the mediators explained the relationship between transformational leadership and OCB. When testing a multi-mediator model, LMX was the strongest mediator. When testing a model with a latent attitudinal mechanism and a latent relational mechanism, the relational mechanism was the stronger mediator of the relationship between transformational leadership and OCB. Our findings help to better understand the underlying mechanisms of the relationship between transformational leadership and OCB. PMID:28848478

Mediation Analysis: A Practitioner's Guide.

PubMed

VanderWeele, Tyler J

2016-01-01

This article provides an overview of recent developments in mediation analysis, that is, analyses used to assess the relative magnitude of different pathways and mechanisms by which an exposure may affect an outcome. Traditional approaches to mediation in the biomedical and social sciences are described. Attention is given to the confounding assumptions required for a causal interpretation of direct and indirect effect estimates. Methods from the causal inference literature to conduct mediation in the presence of exposure-mediator interactions, binary outcomes, binary mediators, and case-control study designs are presented. Sensitivity analysis techniques for unmeasured confounding and measurement error are introduced. Discussion is given to extensions to time-to-event outcomes and multiple mediators. Further flexible modeling strategies arising from the precise counterfactual definitions of direct and indirect effects are also described. The focus throughout is on methodology that is easily implementable in practice across a broad range of potential applications.

Interventional effects for mediation analysis with multiple mediators

PubMed Central

Vansteelandt, Stijn; Daniel, Rhian M.

2016-01-01

The mediation formula for the identification of natural (in)direct effects has facilitated mediation analyses that better respect the nature of the data, with greater consideration of the need for confounding control. The default assumptions on which it relies are strong, however. In particular, they are known to be violated when confounders of the mediator–outcome association are affected by the exposure. This complicates extensions of counterfactual-based mediation analysis to settings that involve repeatedly measured mediators, or multiple correlated mediators. VanderWeele, Vansteelandt, and Robins21 introduced so-called interventional (in)direct effects. These can be identified under much weaker conditions than natural (in)direct effects, but have the drawback of not adding up to the total effect. In this article, we adapt their proposal in order to achieve an exact decomposition of the total effect, and extend it to the multiple mediator setting. Interestingly, the proposed effects capture the path-specific effects of an exposure on an outcome that are mediated by distinct mediators, even when – as often – the structural dependence between the multiple mediators is unknown; for instance, when the direction of the causal effects between the mediators is unknown, or there may be unmeasured common causes of the mediators. PMID:27922534

Patients' perceptions of sharing in decisions: a systematic review of interventions to enhance shared decision making in routine clinical practice.

PubMed

Légaré, France; Turcotte, Stéphane; Stacey, Dawn; Ratté, Stéphane; Kryworuchko, Jennifer; Graham, Ian D

2012-01-01

Shared decision making is the process in which a healthcare choice is made jointly by the health professional and the patient. Little is known about what patients view as effective or ineffective strategies to implement shared decision making in routine clinical practice. This systematic review evaluates the effectiveness of interventions to improve health professionals' adoption of shared decision making in routine clinical practice, as seen by patients. We searched electronic databases (PubMed, the Cochrane Library, EMBASE, CINAHL, and PsycINFO) from their inception to mid-March 2009. We found additional material by reviewing the reference lists of the studies found in the databases; systematic reviews of studies on shared decision making; the proceedings of various editions of the International Shared Decision Making Conference; and the transcripts of the Society for Medical Decision Making's meetings. In our study selection, we included randomized controlled trials, controlled clinical trials, controlled before-and-after studies, and interrupted time series analyses in which patients evaluated interventions to improve health professionals' adoption of shared decision making. The interventions in question consisted of the distribution of printed educational material; educational meetings; audit and feedback; reminders; and patient-mediated initiatives (e.g. patient decision aids). Two reviewers independently screened the studies and extracted data. Statistical analyses considered categorical and continuous process measures. We computed the standardized effect size for each outcome at the 95% confidence interval. The primary outcome of interest was health professionals' adoption of shared decision making as reported by patients in a self-administered questionnaire. Of the 6764 search results, 21 studies reported 35 relevant comparisons. Overall, the quality of the studies ranged from 0% to 83%. Only three of the 21 studies reported a clinically significant effect for the primary outcome that favored the intervention. The first study compared an educational meeting and a patient-mediated intervention with another patient-mediated intervention (median improvement of 74%). The second compared an educational meeting, a patient-mediated intervention, and audit and feedback with an educational meeting on an alternative topic (improvement of 227%). The third compared an educational meeting and a patient-mediated intervention with usual care (p = 0.003). All three studies were limited to the patient-physician dyad. To reduce bias, future studies should improve methods and reporting, and should analyze costs and benefits, including those associated with training of health professionals. Multifaceted interventions that include educating health professionals about sharing decisions with patients and patient-mediated interventions, such as patient decision aids, appear promising for improving health professionals' adoption of shared decision making in routine clinical practice as seen by patients.

Mediators of Effects of a Selective Family-Focused Violence Prevention Approach for Middle School Students

PubMed Central

2013-01-01

This study examined how parenting and family characteristics targeted in a selective prevention program mediated effects on key youth proximal outcomes related to violence perpetration. The selective intervention was evaluated within the context of a multi-site trial involving random assignment of 37 schools to four conditions: a universal intervention composed of a student social-cognitive curriculum and teacher training, a selective family-focused intervention with a subset of high-risk students, a condition combining these two interventions, and a no-intervention control condition. Two cohorts of sixth-grade students (total N=1,062) exhibiting high levels of aggression and social influence were the sample for this study. Analyses of pre-post change compared to controls using intent-to-treat analyses found no significant effects. However, estimates incorporating participation of those assigned to the intervention and predicted participation among those not assigned revealed significant positive effects on student aggression, use of aggressive strategies for conflict management, and parental estimation of student’s valuing of achievement. Findings also indicated intervention effects on two targeted family processes: discipline practices and family cohesion. Mediation analyses found evidence that change in these processes mediated effects on some outcomes, notably aggressive behavior and valuing of school achievement. Results support the notion that changing parenting practices and the quality of family relationships can prevent the escalation in aggression and maintain positive school engagement for high-risk youth. PMID:21932067

[The mediating role of the interpersonal schemas between parenting styles and psychological symptoms: a schema focused view].

PubMed

Soygüt, Gonca; Cakir, Zehra

2009-01-01

The first aim of this study was to examine the relationships between perceived parenting styles and interpersonal schemas. The second purpose was to investigate the mediator role of interpersonal schemas between perceived parenting styles and psychological symptoms. University students (N=94), ages ranging between 17-26, attending to different faculty and classes, have completed Interpersonal Schema Questionnaire, Young Parenting Inventory and Symptom Check List-90. A series of regression analyses revealed that perceived parenting styles have predictive power on a number of interpersonal schemas. Further analyses pointed out that the mediator role of Hostility situation of interpersonal schemas between psychological symptoms and normative, belittling/criticizing, pessimistic/worried parenting styles on the mother forms (Sobel z= 1.94-2.08, p < .01); and normative, belittling/criticizing, emotionally depriving, pessimistic/worried, punitive, and restricted/emotionally inhibited parenting styles (Sobel z= 2.20-2.86, p < .05-.01) on the father forms of the scales. Regression analyses pointed out the predictive power of perceived parenting styles on interpersonal schemas. Moreover, the mediator role of interpersonal schemas between perceived parenting styles and psychological symptoms was also observed. Excluding pessimistic/anxious parenting styles, perceived parenting styles of mothers and fathers differed in their relation to psychological symptoms. In overall evaluation, we believe that, although schemas and parental styles have some universalities in relation to their impacts on psychological health, further research is necessary to address their implications and possible paternal differences in our collectivistic cultural context.

Domain- and nucleotide-specific Rev response element regulation of feline immunodeficiency virus production

PubMed Central

Na, Hong; Huisman, Willem; Ellestad, Kristofor K.; Phillips, Tom R.; Power, Christopher

2010-01-01

Computational analysis of feline immunodeficiency virus (FIV) RNA sequences indicated that common FIV strains contain a rev response element (RRE) defined by a long unbranched hairpin with 6 stem-loop sub-domains, termed stem-loop A (SLA). To examine the role of the RNA secondary structure of the RRE, mutational analyses were performed in both an infectious FIV molecular clone and a FIV CAT-RRE reporter system. These studies disclosed that the stems within SLA (SA1, 2, 3, 4, and 5) of the RRE were critical but SA6 was not essential for FIV replication and CAT expression. These studies also revealed that the secondary structure rather than an antisense protein (ASP) mediates virus expression and replication in vitro. In addition, a single synonymous mutation within the FIV-RRE, SA3/45, reduced viral reverse transcriptase activity and p24 expression after transfection but in addition also showed a marked reduction in viral expression and production following infection. PMID:20570310

Fluid Centrality: A Social Network Analysis of Social-Technical Relations in Computer-Mediated Communication

ERIC Educational Resources Information Center

Enriquez, Judith Guevarra

2010-01-01

In this article, centrality is explored as a measure of computer-mediated communication (CMC) in networked learning. Centrality measure is quite common in performing social network analysis (SNA) and in analysing social cohesion, strength of ties and influence in CMC, and computer-supported collaborative learning research. It argues that measuring…

Socioenvironmental Risk and Adjustment in Latino Youth: The Mediating Effects of Family Processes and Social Competence

ERIC Educational Resources Information Center

Prelow, Hazel M.; Loukas, Alexandra; Jordan-Green, Lisa

2007-01-01

The direct and mediated effects of socioenvironmental risk on internalizing and externalizing problems among Latino youth aged 10-14 were examined using prospective analyses. Participants in this study were 464 Latino mother and child dyads surveyed as part of the "Welfare, Children & Families: A Three City Study." It was hypothesized that…

The Complexity of Learning: Exploring the Interplay of Different Mediational Means in Group Learning with Digital Tools

ERIC Educational Resources Information Center

Engeness, Irina; Edwards, Anne

2017-01-01

The relationship between the different mediational means for supporting students' learning with digital tools in science group work in a Norwegian lower-secondary school is examined. Analyses of teacher-student and student-student interactions are located in cultural-historical theory and draw on Galperin's conceptualisation of learning processes.…

The Relations between Implicit Intelligence Beliefs, Autonomous Academic Motivation, and School Persistence Intentions: A Mediation Model

ERIC Educational Resources Information Center

Renaud-Dubé, Andréanne; Guay, Frédéric; Talbot, Denis; Taylor, Geneviève; Koestner, Richard

2015-01-01

This study attempts to test a model in which the relation between implicit theories of intelligence and students' school persistence intentions are mediated by intrinsic, identified, introjected, and external regulations. Six hundred and fifty students from a high school were surveyed. Contrary to expectations, results from ESEM analyses indicated…

An Evaluation of the Pattern between Students' Motivation, Learning Strategies and Their Epistemological Beliefs: The Mediator Role of Motivation

ERIC Educational Resources Information Center

Sen, S.; Yilmaz, A.; Yurdagül, H.

2014-01-01

This study aims at analysing the relations between students' achievement motivation, learning strategies and their epistemological beliefs in learning through structural equation modelling, and at exploring the mediation role of motivation in the relations between learning strategies and epistemological beliefs. The study group was composed of 446…

Parenting Styles and Bullying at School: The Mediating Role of Locus of Control

ERIC Educational Resources Information Center

Georgiou, Stelios N.; Ioannou, Myria; Stavrinides, Panayiotis

2017-01-01

The current study examined the mediating role of children's locus of control in the relation between parenting styles and bully-victim experiences at school. Participants were 447 students aged 10 and 11 years old from 13 different elementary, urban, and rural schools in Cyprus. Analyses using structural equation modeling showed that parenting…

Educators' Understanding of the Mediation Role in the Classroom

ERIC Educational Resources Information Center

Ngidi, D. P.

2012-01-01

This study investigated educators' understanding of the mediation role in the classroom. A quantitative research approach was used in a survey of a sample of 261 participants. To this end, a questionnaire was used for collecting data. The Chi-square test was used to analyse data and to test the hypotheses of the study. The findings indicated that…

Transcriptomic profiling-based mutant screen reveals three new transcription factors mediating menadione resistance in Neurospora crassa.

PubMed

Zhu, Jufen; Yu, Xinxu; Xie, Baogui; Gu, Xiaokui; Zhang, Zhenying; Li, Shaojie

2013-06-01

To gain insight into the regulatory mechanisms of oxidative stress responses in filamentous fungi, the genome-wide transcriptional response of Neurospora crassa to menadione was analysed by digital gene expression (DGE) profiling, which identified 779 upregulated genes and 576 downregulated genes. Knockout mutants affecting 130 highly-upregulated genes were tested for menadione sensitivity, which revealed that loss of the transcription factor siderophore regulation (SRE) (a transcriptional repressor for siderophore biosynthesis), catatase-3, cytochrome c peroxidase or superoxide dismutase 1 copper chaperone causes hypersensitivity to menadione. Deletion of sre dramatically increased transcription of the siderophore biosynthesis gene ono and the siderophore iron transporter gene sit during menadione stress, suggesting that SRE is required for repression of iron uptake under oxidative stress conditions. Contrary to its phenotype, the sre deletion mutant showed higher transcriptional levels of genes encoding reactive oxygen species (ROS) scavengers than wild type during menadione stress, which implies that the mutant suffers a higher level of oxidative stress than wild type. Uncontrolled iron uptake in the sre mutant might exacerbate cellular oxidative stress. This is the first report of a negative regulator of iron assimilation participating in the fungal oxidative stress response. In addition to SRE, eight other transcription factor genes were also menadione-responsive but their single gene knockout mutants showed wild-type menadione sensitivity. Two of them, named as mit-2 (menadione induced transcription factor-2) and mit-4 (menadione induced transcription factor-4), were selected for double mutant analysis. The double mutant was hypersensitive to menadione. Similarly, the double mutation of mit-2 and sre also had additive effects on menadione sensitivity, suggesting multiple transcription factors mediate oxidative stress resistance in an additive manner. Copyright © 2013 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Functional K(ATP) channels in the rat retinal microvasculature: topographical distribution, redox regulation, spermine modulation and diabetic alteration.

PubMed

Ishizaki, Eisuke; Fukumoto, Masanori; Puro, Donald G

2009-05-15

The essential task of the circulatory system is to match blood flow to local metabolic demand. However, much remains to be learned about this process. To better understand how local perfusion is regulated, we focused on the functional organization of the retinal microvasculature, which is particularly well adapted for the local control of perfusion. Here, we assessed the distribution and regulation of functional K(ATP) channels whose activation mediates the hyperpolarization induced by adenosine. Using microvascular complexes freshly isolated from the rat retina, we found a topographical heterogeneity in the distribution of functional K(ATP) channels; capillaries generate most of the K(ATP) current. The initiation of K(ATP)-induced responses in the capillaries supports the concept that the regulation of retinal perfusion is highly decentralized. Additional study revealed that microvascular K(ATP) channels are redox sensitive, with oxidants increasing their activity. Furthermore, the oxidant-mediated activation of these channels is driven by the polyamine spermine, whose catabolism produces oxidants. In addition, our observation that spermine-dependent oxidation occurs predominately in the capillaries accounts for why they generate most of the K(ATP) current detected in retinal microvascular complexes. Here, we also analysed retinal microvessels of streptozotocin-injected rats. We found that soon after the onset of diabetes, an increase in spermine-dependent oxidation at proximal microvascular sites boosts their K(ATP) current and thereby virtually eliminates the topographical heterogeneity of functional K(ATP) channels. We conclude that spermine-dependent oxidation is a previously unrecognized mechanism by which this polyamine modulates ion channels; in addition to a physiological role, spermine-dependent oxidation may also contribute to microvascular dysfunction in the diabetic retina.

A Systematic Study of the Effect of Different Molecular Weights of Hyaluronic Acid on Mesenchymal Stromal Cell-Mediated Immunomodulation

PubMed Central

Gómez-Aristizábal, Alejandro; Kim, Kyung-Phil; Viswanathan, Sowmya

2016-01-01

Introduction Osteoarthritis (OA) is associated with chronic inflammation, and mesenchymal stromal cells (MSCs) have been shown to provide pain relief and reparative effects in clinical investigations. MSCs are often delivered with hyaluronic acid (HA), although the combined mechanism of action is not fully understood; we thus investigated the immunomodulatory effects of combining MSCs with different molecular weights (MW) of HA. Methods HAs with MWs of 1.6 MDa (hHA), 150 kDa or 7.5 kDa, were added to MSCs alone or MSC-immune cell co-cultures. Gene expression analyses, flow cytometry and cytokine measurements were assessed to determine the effect of HAs on the MSC interactions with immune cells. Results MSCs in the presence of HAs, in both normal and lymphocyte-conditioned medium, showed negligible changes in gene expression. While addition of hHA resulted in increased proliferation of activated lymphocytes, both in the presence and absence of MSCs, the overall combined effect was a more regulated, homeostatic one; this was supported by higher ratios of secreted IL10/IFNγ and IL10/IL2, in lymphocyte cultures, than with lower MW HAs or no HA, both in the presence and absence of MSCs. In addition, examination of monocyte-derived macrophages showed an increased M2 macrophage frequency (CD14+CD163+CD206+) in the presence of hHA, both with and without MSCs. Conclusions hHA produces a less pro-inflammatory environment than lower MW HAs. Moreover, combining hHA with MSCs has an additive effect on the MSC-mediated immunomodulation, suggestive of a more potent combination treatment modality for OA. PMID:26820314

Assembly of the Arp5 (Actin-related Protein) Subunit Involved in Distinct INO80 Chromatin Remodeling Activities*

PubMed Central

Yao, Wei; Beckwith, Sean L.; Zheng, Tina; Young, Thomas; Dinh, Van T.; Ranjan, Anand; Morrison, Ashby J.

2015-01-01

ATP-dependent chromatin remodeling, which repositions and restructures nucleosomes, is essential to all DNA-templated processes. The INO80 chromatin remodeling complex is an evolutionarily conserved complex involved in diverse cellular processes, including transcription, DNA repair, and replication. The functional diversity of the INO80 complex can, in part, be attributed to specialized activities of distinct subunits that compose the complex. Furthermore, structural analyses have identified biochemically discrete subunit modules that assemble along the Ino80 ATPase scaffold. Of particular interest is the Saccharomyces cerevisiae Arp5-Ies6 module located proximal to the Ino80 ATPase and the Rvb1-Rvb2 helicase module needed for INO80-mediated in vitro activity. In this study we demonstrate that the previously uncharacterized Ies2 subunit is required for Arp5-Ies6 association with the catalytic components of the INO80 complex. In addition, Arp5-Ies6 module assembly with the INO80 complex is dependent on distinct conserved domains within Arp5, Ies6, and Ino80, including the spacer region within the Ino80 ATPase domain. Arp5-Ies6 interacts with chromatin via assembly with the INO80 complex, as IES2 and INO80 deletion results in loss of Arp5-Ies6 chromatin association. Interestingly, ectopic addition of the wild-type Arp5-Ies6 module stimulates INO80-mediated ATP hydrolysis and nucleosome sliding in vitro. However, the addition of mutant Arp5 lacking unique insertion domains facilitates ATP hydrolysis in the absence of nucleosome sliding. Collectively, these results define the requirements of Arp5-Ies6 assembly, which are needed to couple ATP hydrolysis to productive nucleosome movement. PMID:26306040

Positive affect, negative affect, stress, and social support as mediators of the forgiveness-health relationship.

PubMed

Green, Michelle; Decourville, Nancy; Sadava, Stanley

2012-01-01

Structural equation modeling was used to test a model in which positive affect, negative affect, perceived stress, and social support were hypothesized to mediate the relationship between forgiveness and mental and physical health. Six hundred and twenty-three undergraduates completed a battery of self-report measures. Results of the analyses indicated that the forgiveness-health relation was mediated by positive affect, negative affect, stress, and the interrelationship between negative affect and stress. There was limited support for social support and the interrelationship between positive affect and social support as mediators. The results suggested that the relationship between forgiveness and health is mediated rather than direct. Implications and directions for future research are discussed.

Evaluating mediation and moderation effects in school psychology: A presentation of methods and review of current practice

PubMed Central

Fairchild, Amanda J.; McQuillin, Samuel D.

2017-01-01

Third variable effects elucidate the relation between two other variables, and can describe why they are related or under what conditions they are related. This article demonstrates methods to analyze two third-variable effects: moderation and mediation. The utility of examining moderation and mediation effects in school psychology is described and current use of the analyses in applied school psychology research is reviewed and evaluated. Proper statistical methods to test the effects are presented, and different effect size measures for the models are provided. Extensions of the basic moderator and mediator models are also described. PMID:20006988

Evaluating mediation and moderation effects in school psychology: a presentation of methods and review of current practice.

PubMed

Fairchild, Amanda J; McQuillin, Samuel D

2010-02-01

Third variable effects elucidate the relation between two other variables, and can describe why they are related or under what conditions they are related. This article demonstrates methods to analyze two third-variable effects: moderation and mediation. The utility of examining moderation and mediation effects in school psychology is described and current use of the analyses in applied school psychology research is reviewed and evaluated. Proper statistical methods to test the effects are presented, and different effect size measures for the models are provided. Extensions of the basic moderator and mediator models are also described.

Remediating politics: brand(ed) new sexualities and real bodies online.

PubMed

Fotopoulou, Aristea

2013-01-01

This article suggests that, in a world emerging in and through mediation, branded sex bloggers and portals become (re)mediators of queer and feminist politics. It examines the websites of two porn production companies, Nofauxxx and Furry Girl, and analyses how they respond to older media forms, re-articulate long-standing debates about pornography in new mediated environments, and re-signify the pornographic object. Key in this process is the circulation of "authenticity," "real bodies," and "diversity" discourses. Through this circulation, sex blogger/brand portals mediate models of queer and feminist political engagement entrenched with notions of digital networks and free markets more generally.

Parental mediation and cyberbullying - a longitudinal study.

PubMed

Chng, Grace S; Liau, Albert; Khoo, Angeline; Li, Dongdong

2014-01-01

Parents use active and restrictive mediation strategies to guide and regulate children's online participation and the online risks they encounter. However, changes in parental mediation do occur over time and the effectiveness of these strategies on cyberbullying demands for further empirical investigation. The current study addresses these issues with a sample of 1084 students (49% girls) in a longitudinal, three-wave design. Gender differences were tested via multi-group analyses. Longitudinal growth models showed that parental use of both active and restrictive mediation decreased over time. For both types of mediation, the mean rate of change had a significant effect on boys' engagement in cyberbullying, but not for girls. Initial levels of restrictive mediation, but not active mediation, were found to be significantly predictive of cyberbullying in both genders. Girls had higher initial levels of both parental mediation types in comparison to boys. The results reveal that the effectiveness of active and restrictive mediation in relation to students' cyberbullying differs and informs us on gender differences. The implications of these results for parental education in online mediation are discussed.

Causal Models for Mediation Analysis: An Introduction to Structural Mean Models.

PubMed

Zheng, Cheng; Atkins, David C; Zhou, Xiao-Hua; Rhew, Isaac C

2015-01-01

Mediation analyses are critical to understanding why behavioral interventions work. To yield a causal interpretation, common mediation approaches must make an assumption of "sequential ignorability." The current article describes an alternative approach to causal mediation called structural mean models (SMMs). A specific SMM called a rank-preserving model (RPM) is introduced in the context of an applied example. Particular attention is given to the assumptions of both approaches to mediation. Applying both mediation approaches to the college student drinking data yield notable differences in the magnitude of effects. Simulated examples reveal instances in which the traditional approach can yield strongly biased results, whereas the RPM approach remains unbiased in these cases. At the same time, the RPM approach has its own assumptions that must be met for correct inference, such as the existence of a covariate that strongly moderates the effect of the intervention on the mediator and no unmeasured confounders that also serve as a moderator of the effect of the intervention or the mediator on the outcome. The RPM approach to mediation offers an alternative way to perform mediation analysis when there may be unmeasured confounders.

Patient Expectancy as a Mediator of Placebo Effects in Antidepressant Clinical Trials.

PubMed

Rutherford, Bret R; Wall, Melanie M; Brown, Patrick J; Choo, Tse-Hwei; Wager, Tor D; Peterson, Bradley S; Chung, Sarah; Kirsch, Irving; Roose, Steven P

2017-02-01

Causes of placebo effects in antidepressant trials have been inferred from observational studies and meta-analyses, but their mechanisms have not been directly established. The goal of this study was to examine in a prospective, randomized controlled trial whether patient expectancy mediates placebo effects in antidepressant studies. Adult outpatients with major depressive disorder were randomly assigned to open or placebo-controlled citalopram treatment. Following measurement of pre- and postrandomization expectancy, participants were treated with citalopram or placebo for 8 weeks. Independent samples t tests determined whether patient expectancy differed between the open and placebo-controlled groups, and mixed-effects models assessed group effects on Hamilton Depression Rating Scale (HAM-D) scores over time while controlling for treatment assignment. Finally, mediation analyses tested whether between-group differences in patient expectancy mediated the group effect on HAM-D scores. Postrandomization expectancy scores were significantly higher in the open group (mean=12.1 [SD=2.1]) compared with the placebo-controlled group (mean=11.0 [SD=2.0]). Mixed-effects modeling revealed a significant week-by-group interaction, indicating that HAM-D scores for citalopram-treated participants declined at a faster rate in the open group compared with the placebo-controlled group. Patient expectations postrandomization partially mediated group effects on week 8 HAM-D. Patient expectancy is a significant mediator of placebo effects in antidepressant trials. Expectancy-related interventions should be investigated as a means of controlling placebo responses in antidepressant clinical trials and improving patient outcome in clinical treatment.

Understanding catastrophizing from a misdirected problem-solving perspective.

PubMed

Flink, Ida K; Boersma, Katja; MacDonald, Shane; Linton, Steven J

2012-05-01

The aim is to explore pain catastrophizing from a problem-solving perspective. The links between catastrophizing, problem framing, and problem-solving behaviour are examined through two possible models of mediation as inferred by two contemporary and complementary theoretical models, the misdirected problem solving model (Eccleston & Crombez, 2007) and the fear-anxiety-avoidance model (Asmundson, Norton, & Vlaeyen, 2004). In this prospective study, a general population sample (n= 173) with perceived problems with spinal pain filled out questionnaires twice; catastrophizing and problem framing were assessed on the first occasion and health care seeking (as a proxy for medically oriented problem solving) was assessed 7 months later. Two different approaches were used to explore whether the data supported any of the proposed models of mediation. First, multiple regressions were used according to traditional recommendations for mediation analyses. Second, a bootstrapping method (n= 1000 bootstrap resamples) was used to explore the significance of the indirect effects in both possible models of mediation. The results verified the concepts included in the misdirected problem solving model. However, the direction of the relations was more in line with the fear-anxiety-avoidance model. More specifically, the mediation analyses provided support for viewing catastrophizing as a mediator of the relation between biomedical problem framing and medically oriented problem-solving behaviour. These findings provide support for viewing catastrophizing from a problem-solving perspective and imply a need to examine and address problem framing and catastrophizing in back pain patients. ©2011 The British Psychological Society.

Relationship between resilience, social support as well as anxiety/depression of lung cancer patients: A cross-sectional observation study.

PubMed

Hu, Tingjie; Xiao, Jian; Peng, Juan; Kuang, Xiao; He, Bixiu

2018-01-01

The mood of patients with lung carcinoma would be greatly influenced by the diagnosing and treating processes. This study was aimed to explore the effects of resilience between social assistance and anxiety/depression of patients with lung cancer, which may assist in clinical intervention. A cross-sectional pilot study was conducted on lung cancer patients at Xiangya Hospital of Central South University, China. A total of 289 patients aged 25-81 years were included in this study. Correlational analyses revealed that anxiety/depression was negatively associated with psychological resilience and each dimension of social assistance, including subjective support, objective support along with the supports utilization (P < 0.01). Furthermore, psychological resilience was positively related to subjective support (P < 0.01), support utilization (P < 0.01) along with objective support (P < 0.05). Mediational analyses showed that, on the one hand, resilience could partially mediate the relation between anxiety and subjective support and totally mediate the relationship between support utilization and anxiety. On the other hand, resilience could totally mediate the relation between depression and subjective support and partially mediate the relation between support utilization and depression. However, resilience did not play an intermediary role between anxiety/depression and objective support. Lower psychological anxiety and depression would be experienced by lung cancer patients with higher resilience and social support. The level of anxiety and depression would be indirectly affected by social support through the mediation of resilience.