Khulan, Batbayar; Drake, Amanda J
Epidemiological evidence suggests that exposure to an adverse environment in early life is associated with an increased risk of cardio-metabolic and behavioral disorders in adulthood, a phenomenon termed 'early life programming'. One major hypothesis for early life programming is fetal glucocorticoid overexposure. In animal studies, prenatal glucocorticoid excess as a consequence of maternal stress or through exogenous administration to the mother or fetus is associated with programming effects on cardiovascular and metabolic systems and on the brain. These effects can be transmitted to subsequent generations. Studies in humans provide some evidence that prenatal glucocorticoid exposure may exert similar programming effects on glucose/insulin homeostasis, blood pressure and neurodevelopment. The mechanisms by which glucocorticoids mediate these effects are unclear but may include a role for epigenetic modifications. This review discusses the evidence for glucocorticoid programming in animal models and in humans. Copyright © 2012 Elsevier Ltd. All rights reserved.
This paper reports an exploratory study of a school peer mediation program implemented as an alternative way to manage bullying and other destructive conflict. The study explores the effects of the program on the well-being of members of the school community by examining perceptions of students, staff and a sample of parents and former students. Drawing on therapeutic jurisprudence (TJ) the study explores whether the component parts of the program, separately or together, promote intended or unintended therapeutic effects. The preliminary findings of the study emphasise the importance of peer mediation training and suggest that existing scholarship in the area of school conflict resolution and peer mediation, when viewed through a TJ lens, may provide valuable insights into how to optimally configure programs for development and adoption in schools and other community settings. The study highlights the lack of attention paid by the legal system to valuable scholarship in the area of school conflict resolution and peer mediation, which may have implications for the understanding and development of legal processes and the law in general. Copyright © 2010 Elsevier Ltd. All rights reserved.
Eckenrode, John; Campa, Mary I; Morris, Pamela A; Henderson, Charles R; Bolger, Kerry E; Kitzman, Harriet; Olds, David L
We examine maternal life-course mediators of the impact of a nurse home visitation program on reducing child maltreatment among participants in the Elmira trial of the Nurse Family Partnership program from the first child's birth through age 15. For women having experienced low to moderate levels of domestic violence, program effects on the number of confirmed maltreatment reports were mediated by reductions in numbers of subsequent children born to mothers and their reported use of public assistance. Together, the two mediators explained nearly one half of the total effect of nurse home visiting on child maltreatment. The long-term success of this program on reducing child maltreatment can be explained, at least in part, by its positive effect on pregnancy planning and economic self-sufficiency.
Kendra M. Lewis
Full Text Available Mitigating and preventing substance use among adolescents requires approaches that address the multitude of factors that influence this behavior. Such approaches must be tested, not only for evidence of empirical effectiveness, but also to determine the mechanisms by which they are successful. The aims of the present study were twofold: 1 To determine the effectiveness of a school-based social-emotional and character development (SECD program, Positive Action (PA, in reducing substance use (SU among a sample of U.S. youth living in a low-income, urban environment, and 2 to test one mechanism by which the program achieves its success. We used longitudinal mediation analysis to test the hypotheses that: 1 students attending PA intervention schools engage in significantly less SU than students attending control schools, 2 students attending PA intervention schools show significantly better change in SECD than students attending control schools, and 3 the effect of the PA intervention on SU is mediated by the change in SECD. Analyses revealed program effects on both SECD and SU, a relationship between SECD and SU, and the effects of PA on SU were completely mediated by changes in SECD. Future research directions and implications for school-based social-emotional and character development efforts and substance use prevention are addressed.
Zhou, Qing; Sandler, Irwin N.; Millsap, Roger E.; Wolchik, Sharlene A.; Dawson-McClure, Spring R.
This study examines whether program effects on mother-child relationship quality and effective discipline mediated the 6-year longitudinal effects of the New Beginnings Program (NBP) to improve mental health and competence outcomes in 218 adolescents from divorced families in a randomized experimental trial. The NBP is a theory-based and…
... 7 Agriculture 7 2010-01-01 2010-01-01 false Annual certification of State mediation programs. 785... AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS CERTIFIED STATE MEDIATION PROGRAM § 785.3 Annual certification of State mediation programs. To obtain FSA certification of the State's mediation program, the...
... 7 Agriculture 7 2010-01-01 2010-01-01 false Grants to certified State mediation programs. 785.4..., DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS CERTIFIED STATE MEDIATION PROGRAM § 785.4 Grants to certified State mediation programs. (a) Eligibility. To be eligible to receive a grant, a State mediation program...
Stice, Eric; Rohde, Paul; Seeley, John R.; Gau, Jeff M.
Objective: Evaluate a new 5-step method for testing mediators hypothesized to account for the effects of depression prevention programs. Method: In this indicated prevention trial, at-risk teens with elevated depressive symptoms were randomized to a group cognitive-behavioral (CB) intervention, group supportive expressive intervention, CB…
MacKinnon, David P.
This paper describes methods for testing mediation and moderation effects in a dataset, both together and separately. Investigations of this kind are especially valuable in prevention research to obtain information on the process by which a program achieves its effects and whether the program is effective for subgroups of individuals. A general model that simultaneously estimates mediation and moderation effects is presented, and the utility of combining the effects into a single model is described. Possible effects of interest in the model are explained, as are statistical methods to assess these effects. The methods are further illustrated in a hypothetical prevention program example. PMID:19003535
Whitehill, Jennifer M; Webster, Daniel W; Frattaroli, Shannon; Parker, Elizabeth M
Cities are increasingly adopting CeaseFire, an evidence-based public health program that uses specialized outreach workers, called violence interrupters (VIs), to mediate potentially violent conflicts before they lead to a shooting. Prior research has linked conflict mediation with program-related reductions in homicides, but the specific conflict mediation practices used by effective programs to prevent imminent gun violence have not been identified. We conducted case studies of CeaseFire programs in two inner cities using qualitative data from focus groups with 24 VIs and interviews with eight program managers. Study sites were purposively sampled to represent programs with more than 1 year of implementation and evidence of program effectiveness. Staff with more than 6 months of job experience were recruited for participation. Successful mediation efforts were built on trust and respect between VIs and the community, especially high-risk individuals. In conflict mediation, immediate priorities included separating the potential shooter from the intended victim and from peers who may encourage violence, followed by persuading the parties to resolve the conflict peacefully. Tactics for brokering peace included arranging the return of stolen property and emphasizing negative consequences of violence such as jail, death, or increased police attention. Utilizing these approaches, VIs are capable of preventing gun violence and interrupting cycles of retaliation.
... DEPARTMENT OF AGRICULTURE Farm Service Agency Information Collection; Certified State Mediation... supports the Certified State Mediation Program. The information collection is necessary to ensure the grant... submit comments by any of the following methods: Mail: Carol Wagner, Certified State Mediation Program...
Jenkins, Randall C; Smillov, Arlene E; Goodwin, Matthew A
The Florida Patient Safety and Presuit Mediation Program (FLPSMP) is a mandatory mediation program designed to provide deserving patients with fast, fair compensation while limiting the healthcare provider expenses incurred during traditional litigation. Mediation occurs before litigation begins; therefore, patients with meritorious claims receive compensation often years earlier than they would with extended litigation. This early mediation fosters confidential and candid communication between doctors and patients, which promotes early fact-finding and candid discussion. The program went into effect across the University of Florida (UF) Health system on January 1, 2008. In an article previously published in this journal, we discussed the positive trend observed 2 years after the implementation of the FLPSMP. This article incorporates 5 years of data, which includes new benchmarks with state and national data, to demonstrate that the program can be used successfully as a medical malpractice solution. © 2014 American Society for Healthcare Risk Management of the American Hospital Association.
Eden, S.; Bezer, M.
The research examined the effect of an intervention program employing 3D immersive virtual reality (IVR), which focused on the perception of sequential time, on the mediation level and behavioural aspects of children with intellectual disability (ID). The intervention is based on the mediated learning experience (MLE) theory, which refers the…
Dudley, William N; Benuzillo, Jose G; Carrico, Mineh S
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.
Chan, K. C. G.; Imai, K.; Yam, S. C. P.; Zhang, Z.
An essential goal of program evaluation and scientific research is the investigation of causal mechanisms. Over the past several decades, causal mediation analysis has been used in medical and social sciences to decompose the treatment effect into the natural direct and indirect effects. However, all of the existing mediation analysis methods rely on parametric modeling assumptions in one way or another, typically requiring researchers to specify multiple regression models involving the treat...
Koning, Ina M; Maric, Marija; MacKinnon, David; Vollebergh, Wilma A M
Previous work revealed that the combined parent-student alcohol prevention program (PAS) effectively postponed alcohol initiation through its hypothesized intermediate factors: increase in strict parental rule setting and adolescents' self-control (Koning, van den Eijnden, Verdurmen, Engels, & Vollebergh, 2011). This study examines whether the parental strictness precedes an increase in adolescents' self-control by testing a sequential mediation model. A cluster randomized trial including 3,245 Dutch early adolescents (M age = 12.68, SD = 0.50) and their parents randomized over 4 conditions: (1) parent intervention, (2) student intervention, (3) combined intervention, and (4) control group. Outcome measure was amount of weekly drinking measured at age 12 to 15; baseline assessment (T0) and 3 follow-up assessments (T1-T3). Main effects of the combined and parent intervention on weekly drinking at T3 were found. The effect of the combined intervention on weekly drinking (T3) was mediated via an increase in strict rule setting (T1) and adolescents' subsequent self-control (T2). In addition, the indirect effect of the combined intervention via rule setting (T1) was significant. No reciprocal sequential mediation (self-control at T1 prior to rules at T2) was found. The current study is 1 of the few studies reporting sequential mediation effects of youth intervention outcomes. It underscores the need of involving parents in youth alcohol prevention programs, and the need to target both parents and adolescents, so that change in parents' behavior enables change in their offspring. (c) 2015 APA, all rights reserved).
Fairchild, Amanda J; Mackinnon, David P; Taborga, Marcia P; Taylor, Aaron B
R(2) effect-size measures are presented to assess variance accounted for in mediation models. The measures offer a means to evaluate both component paths and the overall mediated effect in mediation models. Statistical simulation results indicate acceptable bias across varying parameter and sample-size combinations. The measures are applied to a real-world example using data from a team-based health promotion program to improve the nutrition and exercise habits of firefighters. SAS and SPSS computer code are also provided for researchers to compute the measures in their own data.
Fairchild, Amanda J.; MacKinnon, David P.; Taborga, Marcia P.; Taylor, Aaron B.
R2 effect-size measures are presented to assess variance accounted for in mediation models. The measures offer a means to evaluate both component paths and the overall mediated effect in mediation models. Statistical simulation results indicate acceptable bias across varying parameter and sample-size combinations. The measures are applied to a real-world example using data from a team-based health promotion program to improve the nutrition and exercise habits of firefighters. SAS and SPSS computer code are also provided for researchers to compute the measures in their own data. PMID:19363189
Ethisan, P.; Chapman, R.
Elderly population is considered as a vulnerable group and prone to develop multiple medical problems. This aging population is rapidly increasing in developing countries especially in Thailand. Methods: This study was a quasi-experimental study to evaluate the effectiveness of Group-Mediated Lifestyle Physical Activity program on change health benefit in physical activity among elderly people by using validated and reliable Global Physical Activity Questionnaire-GPAQv2. The study was conducted in Phranakhonsiayutthaya district, Ayutthaya province due to its population being the second highest elderly in the Central Region of Thailand. A total of 102 persons of age 60 and over who could read and write Thai language were selected purposively. However, 52 elderly were enrolled in the intervention group and 50 were enrolled for the control group. General Linear Model repeated-measures ANOVA was used to evaluate the effects of Group-Mediated Lifestyle Physical Activity (GLPA) program on change health benefit in physical activity among elderly. Results: Overall health benefit at baseline were similar between intervention and control group and found statistically non-significant with p-value 0.638 (>0.05). However, the mean score of health benefit was 23.21 ± 29.23 in intervention group and 20.74 ± 23.18 in control group. One third of participants of intervention group had not found health benefit due to physical activity while in control group this number was more than half. After elderly received Group-Mediated Lifestyle Physical Activity program intervention for 6 month found significant statistical differences as compared with mean score at baseline (health benefit 6 month, intervention group =40.7 ± 34.28 and control group =4.56 ± 8.79). Conclusion: The effect of Group-Mediated Lifestyle Physical Activity program change intervention was statistically significant in health benefit after intervention program between intervention and control group. Our study
Cook, Jacqueline Yvonne; Boes, Susan R.
A literature review was conducted to understand how mediators and faculty view a Peer Mediation Program (PMP). The review identified four subgroups: mediators, teachers, administrators, and school counselors as well as their views on the success or lack of success of PMPs. The research also reflects how to best engage stakeholders in the mediation…
Stice, Eric; Marti, C. Nathan; Rohde, Paul; Shaw, Heather
Objective: Test the hypothesis that reductions in thin-ideal internalization and body dissatisfaction mediate the effects of a dissonance-based eating disorder prevention program on reductions in eating disorder symptoms over 1-year follow-up. Method: Data were drawn from a randomized effectiveness trial in which 306 female high school students…
Duong, Mylien T; Kelly, Brynn M; Haaland, Wren L; Matsumiya, Brandon; Huey, Stanley J; McCarty, Carolyn A
This study tested potential moderators and mediators of an indicated depression prevention program for middle school students, Positive Thoughts and Actions (PTA). Participants were 120 students randomly assigned to PTA, or a brief, individually administered supportive intervention (Individual Support Program, or ISP). Youths completed measures of depressive symptoms at baseline, post-intervention, and 12-month follow-up. Hierarchical regression was used to test three moderators-ethnic minority status, gender, and baseline depressive symptoms-and three mediators representing functional outcomes targeted by PTA-parent-child communication, attitude towards school, and health behavior. Ethnic minority status did not moderate PTA effects at post-intervention but did moderate PTA effects at 12-month follow-up. At 12 months, PTA appeared to be more effective for White participants than ethnic minority youth. Follow-up analyses suggested this moderation effect was due to the tendency of ethnic minority youth, especially those with fewer symptoms at baseline, to drop out by 12 months. Neither gender nor baseline depressive symptoms moderated the effects of PTA. Although PTA improved health behavior and attitudes toward school, there was no evidence that any of these functional outcomes measured mediated the impact of PTA on depressive symptoms. Future directions are discussed.
Vansteelandt, Stijn; Daniel, Rhian M
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.
Weichold, Karina; Tomasik, Martin J.; Silbereisen, Rainer K.; Spaeth, Michael
In this study, the effectiveness of a life skills program to impede tobacco use in early adolescence was scrutinized. The focus was on the mediating role of yielding to peer pressure. The universal school-based life skills program IPSY (Information + Psychosocial Competence = Protection) against adolescent substance use was implemented over 3…
... state agricultural loan mediation programs? 617.7430 Section 617.7430 Banks and Banking FARM CREDIT... Mediation Programs § 617.7430 Are institutions required to participate in state agricultural loan mediation programs? (a) If initiated by a borrower, System institutions must participate in state mediation programs...
Tein, Jenn-Yun; Sandler, Irwin N; MacKinnon, David P; Wolchik, Sharlene A
This study presents a reanalysis of data from an effective preventive intervention for children from divorced families to test mediation of program effects. The study involved 157 children, age 9-12 years, who were randomly assigned to a parenting program or a literature control condition. Program effects to reduce posttest internalizing problems were mediated through improvement in mother-child relationship quality. Program effects to reduce externalizing problems at posttest and 6 months were mediated through improvement in posttest parental methods of discipline and mother-child relationship quality. The study also describes a new methodology to test mediation of Program x Baseline Status interactions. Analyses demonstrate mediation effects primarily for children who began the program with poorer scores on discipline, mother-child relationship quality, and externalizing problems.
MacKinnon, David P.; Taborga, Marcia P.; Morgan-Lopez, Antonio A.
This paper describes research designs and statistical analyses to investigate how tobacco prevention programs achieve their effects on tobacco use. A theoretical approach to program development and evaluation useful for any prevention program guides the analysis. The theoretical approach focuses on action theory for how the program affects mediating variables and on conceptual theory for how mediating variables are related to tobacco use. Information on the mediating mechanisms by which tobacco prevention programs achieve effects is useful for the development of efficient programs and provides a test of the theoretical basis of prevention efforts. Examples of these potential mediating mechanisms are described including mediated effects through attitudes, social norms, beliefs about positive consequences, and accessibility to tobacco. Prior research provides evidence that changes in social norms are a critical mediating mechanism for successful tobacco prevention. Analysis of mediating variables in single group designs with multiple mediators are described as well as multiple group randomized designs which are the most likely to accurately uncover important mediating mechanisms. More complicated dismantling and constructive designs are described and illustrated based on current findings from tobacco research. Mediation analysis for categorical outcomes and more complicated statistical methods are outlined. PMID:12324176
Latham, Nancy K.; Ni, Pengsheng; Jette, Alan M.
Objectives This study examined whether self-efficacy mediated the effect of the HIP Rehab exercise program on activity limitations in older adults after hip fracture, and whether the mediation effect was different between different gender and age groups. Design Randomized controlled trial (RCT) Setting Community Participants Two hundred and thirty two participants aged 79±9.4 years with hip fracture were randomly assigned to intervention (n=120) or attention control (n=112) groups. Interventions The 6-month intervention, the HIP Rehab, is a functionally-oriented, home-based exercise program. Data was collected at baseline, post-intervention (6 months), and follow-up (9 months). Main outcome measure Activity Measure for Post-Acute Care (AM-PAC) Results The mediation effect of the HIP Rehab exercise program on Basic Mobility function through self-efficacy for exercise was significant at 9 months (βindirect=0.21). Similarly, the mediation effect of the intervention on Daily Activity function through self-efficacy for exercise was significant at 9 months (βindirect=0.49). In subgroup analyses, the mediation effect was significant at 9 months in the younger group (≤79 years old) in comparison to the older group, and was significant in females in comparison to males. Conclusion Self-efficacy may play a partial mediating role for the effect on some longer-term functional outcomes in the HIP Rehab intervention. The results suggest that program components that target self-efficacy should be incorporated in the future hip fracture rehabilitation interventions. Age and gender of the targeted participants may also need to be considered when developing interventions. PMID:25701101
Sears, Lindsay E; Coberley, Carter R; Pope, James E
The aim of this study was to examine the direct and mediated effects of a telephonic health coaching program on changes to healthy behaviors, life satisfaction, and optimism. This longitudinal correlational study of 4881 individuals investigated simple and mediated relationships between participation in a telephonic health risk coaching program and outcomes from three annual Well-being Assessments. Program participation was directly related to improvements in healthy behaviors, life satisfaction and optimism, and indirect effects of coaching on these variables concurrently and over a one-year time lag were also supported. Given previous research that improvements to life satisfaction, optimism, and health behaviors are valuable for individuals, employers, and communities, a clearer understanding of intervention approaches that may impact these outcomes simultaneously can drive greater program effectiveness and value on investment.
Chang, Feng-Hang; Latham, Nancy K; Ni, Pengsheng; Jette, Alan M
To examine whether self-efficacy mediated the effect of the Home-based Post-Hip Fracture Rehabilitation program on activity limitations in older adults after hip fracture and whether the mediating effect was different between sex and age groups. Randomized controlled trial. Community. Participants with hip fracture (N=232; mean age ± SD, 79±9.4y) were randomly assigned to intervention (n=120, 51.7%) and attention control (n=112, 48.3%) groups. The 6-month intervention, the Home-based Post-Hip Fracture Rehabilitation, is a functionally oriented, home-based exercise program. Data were collected at baseline, postintervention (6mo), and follow-up (9mo). Activity Measure for Post-Acute Care. The mediating effect of the Home-based Post-Hip Fracture Rehabilitation program on Basic Mobility function through self-efficacy for exercise was significant at 9 months (βindirect=.21). Similarly, the mediating effect of the intervention on Daily Activity function through self-efficacy for exercise was significant at 9 months (βindirect=.49). In subgroup analyses, the mediating effect was significant at 9 months in the younger group (age, ≤79y) in comparison to the older group and was significant in women in comparison to men. Self-efficacy may play a partial mediating role in the effect on some longer-term functional outcomes in the Home-based Post-Hip Fracture Rehabilitation intervention. The results suggest that program components that target self-efficacy should be incorporated in future hip fracture rehabilitation interventions. Age and sex of the targeted participants may also need to be considered when developing interventions. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Wang, Wei; Nelson, Suchitra; Albert, Jeffrey M
Mediators are intermediate variables in the causal pathway between an exposure and an outcome. Mediation analysis investigates the extent to which exposure effects occur through these variables, thus revealing causal mechanisms. In this paper, we consider the estimation of the mediation effect when the outcome is binary and multiple mediators of different types exist. We give a precise definition of the total mediation effect as well as decomposed mediation effects through individual or sets of mediators using the potential outcomes framework. We formulate a model of joint distribution (probit-normal) using continuous latent variables for any binary mediators to account for correlations among multiple mediators. A mediation formula approach is proposed to estimate the total mediation effect and decomposed mediation effects based on this parametric model. Estimation of mediation effects through individual or subsets of mediators requires an assumption involving the joint distribution of multiple counterfactuals. We conduct a simulation study that demonstrates low bias of mediation effect estimators for two-mediator models with various combinations of mediator types. The results also show that the power to detect a nonzero total mediation effect increases as the correlation coefficient between two mediators increases, whereas power for individual mediation effects reaches a maximum when the mediators are uncorrelated. We illustrate our approach by applying it to a retrospective cohort study of dental caries in adolescents with low and high socioeconomic status. Sensitivity analysis is performed to assess the robustness of conclusions regarding mediation effects when the assumption of no unmeasured mediator-outcome confounders is violated. Copyright © 2013 John Wiley & Sons, Ltd.
Nelson, Suchitra; Albert, Jeffrey M.
Mediators are intermediate variables in the causal pathway between an exposure and an outcome. Mediation analysis investigates the extent to which exposure effects occur through these variables, thus revealing causal mechanisms. In this paper, we consider the estimation of the mediation effect when the outcome is binary and multiple mediators of different types exist. We give a precise definition of the total mediation effect as well as decomposed mediation effects through individual or sets of mediators using the potential outcomes framework. We formulate a model of joint distribution (probit-normal) using continuous latent variables for any binary mediators to account for correlations among multiple mediators. A mediation formula approach is proposed to estimate the total mediation effect and decomposed mediation effects based on this parametric model. Estimation of mediation effects through individual or subsets of mediators requires an assumption involving the joint distribution of multiple counterfactuals. We conduct a simulation study that demonstrates low bias of mediation effect estimators for two-mediator models with various combinations of mediator types. The results also show that the power to detect a non-zero total mediation effect increases as the correlation coefficient between two mediators increases, while power for individual mediation effects reaches a maximum when the mediators are uncorrelated. We illustrate our approach by applying it to a retrospective cohort study of dental caries in adolescents with low and high socioeconomic status. Sensitivity analysis is performed to assess the robustness of conclusions regarding mediation effects when the assumption of no unmeasured mediator-outcome confounders is violated. PMID:23650048
Full Text Available Abstract Objectives This paper aims to identify the mediating mechanisms of a school-based obesity prevention program (DOiT. Methods The DOiT-program was implemented in Dutch prevocational secondary schools and evaluated using a controlled, cluster-randomised trial (September 2003 to May 2004. We examined mediators of effects regarding (1 consumption of sugar containing beverages (SCB; (2 consumption of high caloric snacks; (3 screen-viewing behaviour; and (4 active commuting to school. To improve these behaviours the DOiT-program tried to influence the following potentially mediating variables: attitude, subjective norm, perceived behavioural control, and habit-strength. Results Both in boys (n = 418 and girls (n = 436 the DOiT-intervention reduced SCB consumption (between group difference in boys = -303.5 ml/day, 95% CI: -502.4;-104.5, between group difference in girls = -222.3 ml/day, 95% CI: -371.3;-73.2. The intervention did not affect the other examined behaviours. In girls, no intervention effect on hypothetical mediators was found nor evidence of any mediating mechanisms. Boys in intervention schools improved their attitude towards decreasing SCB consumption, while this behaviour became less of a habit. Indeed, attitude and habit strength were significant mediators of the DOiT-intervention's effect (4.5 and 3.8%, respectively on SCB consumption among boys. Conclusion Our findings imply that interventions aimed at EBRB-change should be gender-specific. Future studies aimed at reducing SCB consumption among boys should target attitude and habit strength as mediating mechanisms. Our study did not resolve the mediating mechanisms in girls. Trial registration International Standard Randomised Controlled Trial Number Register ISRCTN87127361
Chin A Paw, M.J.M.; Singh, A.S.; Brug, J.; Mechelen, van, W.
Abstract Objectives This paper aims to identify the mediating mechanisms of a school-based obesity prevention program (DOiT). Methods The DOiT-program was implemented in Dutch prevocational secondary schools and evaluated using a controlled, cluster-randomised trial (September 2003 to May 2004). We examined mediators of effects regarding (1) consumption of sugar containing beverages (SCB); (2) consumption of high caloric snacks; (3) screen-viewing behaviour; and (4) active commuting to school...
Wang, Wei; Nelson, Suchitra; Albert, Jeffrey M.
Mediators are intermediate variables in the causal pathway between an exposure and an outcome. Mediation analysis investigates the extent to which exposure effects occur through these variables, thus revealing causal mechanisms. In this paper, we consider the estimation of the mediation effect when the outcome is binary and multiple mediators of different types exist. We give a precise definition of the total mediation effect as well as decomposed mediation effects through individual or sets ...
Han, Sang Sook; Kim, Nam Eun
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.
Levenson, Michael R; Aldwin, Carolyn M; Yancura, Loriena
We evaluated the efficacy of an emotional education program that seeks to reduce the intergenerational transmission of negative interaction patterns by increasing forgiveness and spirituality. We examined both reduction of psychological symptoms and increase in positive psychological outcomes over the course of a year, as well as the mediators of this change. At baseline, the sample consisted of 99 participants and 47 waiting list controls. Comparisons of scores from baseline (Time 1) to one week after the Hoffman Quadrinity Process (Time 2) showed large declines in negative affect (depressive symptoms) and increases in both positive outcomes (mastery, empathy, emotional intelligence, life satisfaction, forgiveness, and spiritual experience) and health and well-being. Over the course of a year, most of these gains were sustained, in comparison with the control group. Further, increases in forgiveness and spirituality mediated the effect of program participation on depressive symptoms.
Jeong, Yeon-Gyu; Jeong, Yeon-Jae; Kim, Won-Cheol; Kim, Jeong-Soo
[Purpose] Quality of life (QoL) can be closely related to caregiver burden, which may be a potential mediating effect on the relationships among stroke patient caregivers. This study investigated the predictors of caregiver's QoL based on patient and caregiver characteristics, with caregiver burden as a mediator. [Methods] This study was conducted using surveys, a literature review, and interviews. Survey data were collected from 238 subjects, who were diagnosed with stroke, and their family caregivers from October 2013 to April 2014. [Results] Caregiver health status, income, spouses caring for patients, and duration of hospitalization were identified as significant predictors of caregivers' QoL with a mediating effect of caregiver burden. The time spent on caregiving per day and patient education level were the only direct predictors of caregivers' QoL. [Conclusion] The responsibility of caring for patients with stroke, in particular for a spouse, must be administered by means of a holistic family-centered rehabilitation program. In addition, financial support and availability of various health and social service programs must be comprehensively provided in order to maintain caregivers' well-being.
Tucker, Joan S; Edelen, Maria Orlando; Huang, Wenjing
Parent-child mediation programs are intended to resolve or manage disputes and improve family functioning, but rigorous evaluations of their effectiveness are lacking. Families referred to a community-based mediation program (N = 111) were randomized to an intervention or wait-list control group, and completed three surveys over a 12-week period. With the exception of parent-reported child delinquency (which decreased more in the intervention group), this evaluation provides little support for the short-term effectiveness of parent-child mediation for improving family functioning and reducing child problem behaviors in general. Given that this is the first randomized controlled trial of a parent-child mediation program, additional evaluations involving larger samples and longer follow-ups are needed before firm conclusions can be drawn about the effectiveness of this intervention.
Tucker, Joan S.; Edelen, Maria Orlando; Huang, Wenjing
Parent-child mediation programs are intended to resolve or manage disputes and improve family functioning, but rigorous evaluations of their effectiveness are lacking. Families referred to a community-based mediation program (N=111) were randomized to an intervention or wait-list control group, and completed three surveys over a 12-week period. With the exception of parent-reported child delinquency (which decreased more in the intervention group), this evaluation provides little support for the short-term effectiveness of parent-child mediation for improving family functioning and reducing child problem behaviors in general. Given that this is the first randomized controlled trial of a parent-child mediation program, additional evaluations involving larger samples and longer follow-ups are needed before firm conclusions can be drawn about the effectiveness of this intervention. PMID:26762375
Vansteelandt, Stijn; Daniel, Rhian M.
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...
... INTERNATIONAL TRADE COMMISSION Issuance of Revised Users' Manual for Commission Mediation Program... 65615 (Nov. 8, 2008). The Commission has determined to issue a revised Users' Manual for its program for the mediation of investigations under section 337 of the Tariff Act of 1930. The revised Users' Manual...
O'Rourke, Holly P; MacKinnon, David P
Mediation models are used in prevention and intervention research to assess the mechanisms by which interventions influence outcomes. However, researchers may not investigate mediators in the absence of intervention effects on the primary outcome variable. There is emerging evidence that in some situations, tests of mediated effects can be statistically significant when the total intervention effect is not statistically significant. In addition, there are important conceptual and practical reasons for investigating mediation when the intervention effect is nonsignificant. This article discusses the conditions under which mediation may be present when an intervention effect does not have a statistically significant effect and why mediation should always be considered important. Mediation may be present in the following conditions: when the total and mediated effects are equal in value, when the mediated and direct effects have opposing signs, when mediated effects are equal across single and multiple-mediator models, and when specific mediated effects have opposing signs. Mediation should be conducted in every study because it provides the opportunity to test known and replicable mediators, to use mediators as an intervention manipulation check, and to address action and conceptual theory in intervention models. Mediators are central to intervention programs, and mediators should be investigated for the valuable information they provide about the success or failure of interventions.
Rahm, Dianne; Reed, B. J.; Rydl, Teri L.
An overview of Internet-mediated learning in public affairs programs identifies issues for faculty, students, and administrators, including intellectual property rights, instructional issues, learning approaches, student expectations, logistics and support, complexity of coordination, and organizational control. (DB)
Telephone-mediated group programs are an important but under-utilized medium for reaching frail or disabled older persons' family carers who are in need of support. The primary purpose and style of group programs can range across a broad spectrum–encompassing educational, supportive and therapeutic types. Gerontological social workers are the members of the multidisciplinary care team whose training, experience and supervision makes them most suitable for facilitating this broad range of group types. Drawing on the experience of training a number of group facilitators, this article provides suggestions for social workers contemplating the use of telephone-mediated groups and highlights groupwork skills peculiar to conducting group programs via the telephone.
Zulman, Donna M; Damschroder, Laura J; Smith, Ryan G; Resnick, Paul J; Sen, Ananda; Krupka, Erin L; Richardson, Caroline R
In response to rising health care costs associated with obesity rates, some health care insurers are adopting incentivized technology-enhanced wellness programs. The purpose of this study is to evaluate the large-scale implementation of an incentivized Internet-mediated walking program for obese adults and to examine program acceptance, adherence, and impact. A mixed-methods evaluation was conducted to investigate program implementation, acceptance, and adherence rates, and physical activity rates among program participants. Program implementation was shaped by national and state policies, data security concerns, and challenges related to incentivizing participation. Among 15,397 eligible individuals, 6,548 (43 %) elected to participate in the walking program, achieving an average of 6,523 steps/day (SD 2,610 steps). Participants who uploaded step counts for 75 % of days for a full year (n = 2,885) achieved an average of 7,500 steps (SD 3,093). Acceptance and participation rates in this incentivized Internet-mediated walking program suggest that such interventions hold promise for engaging obese adults in physical activity.
Zugna, Daniela; Richiardi, Lorenzo
Mediation analysis aims to decompose the total effect of the exposure on the outcome into a direct effect (unmediated) and an indirect effect (mediated by a mediator). When the interest also lies on understanding whether the exposure effect differs in different sub-groups of study population or under different scenarios, the mediation analysis needs to be integrated with interaction analysis. In this setting it is necessary to decompose the total effect not only into two components, the direct and indirect effects, but other two components linked to interaction. The interaction between the exposure and the mediator in their effect on the outcome could indeed act through the effect of the exposure on the mediator or through the mediator when the mediator is not totally explained by the exposure. We describe options for decomposition, proposed in literature, of the total effect and we illustrate them through a hypothetical example of the effect of age at diagnosis of cancer on survival, mediated and unmediated by the therapeutical approach, and a numerical example.
Jackson, Christine; Ennett, Susan T; Reyes, H Luz McNaughton; Hayes, Kim A; Dickinson, Denise M; Choi, Seulki; Bowling, J Michael
This 4-year efficacy trial tested whether a home-based, self-administered parenting program could have a long-term effect on children's cognitive susceptibility to alcohol use, and it tested hypothesized moderators and mediators of any such program effect. Using a two-group randomized controlled design, 1076 children (540 treatment; 536 control; mean age of 9.2 years at baseline) completed telephone interviews prior to randomization and follow-up interviews 12, 24, 36, and 48 months post-baseline. Mothers of children randomized to treatment received a 5-month-long parenting program during year 1, followed by two 1-month-long boosters in years 2 and 3. Exposure to the program was significantly inversely associated with susceptibility to alcohol use 48 months post-baseline (b = -0.03, p = .04), with no variation in program effects by parental alcohol use or mother's race/ethnicity or education, suggesting broad public health relevance of the parenting program. Path analyses of simple indirect effects through each hypothesized mediator showed that program exposure positively influenced parental communication to counter pro-drinking influences in the family and media domains and parental rule setting 36 months post-baseline; these variables, in turn, predicted reduced susceptibility to alcohol use 48 months post-baseline. Parallel (multiple) mediation analysis showed that the program had a significant indirect effect on susceptibility through parental rule setting. Together, the findings indicate that internalization of protective alcohol-related expectancies and intentions is possible among children whose mothers provide early exposure to alcohol-specific socialization. Additional research is needed to link alcohol-specific socialization during childhood with adolescent drinking outcomes.
Lu, Frank Jing-Horng; Hsu, Eva Ya-Wen; Wang, Junn-Ming; Huang, Mei-Yao; Chang, Jo-Ning; Wang, Chien-Hsin
The purpose of this study was to examine the associations of exercise identity, exercise commitment, exercise dependence, and, particularly, the mediating effects of exercise commitment on the relationship between exercise identity and exercise dependence. 253 Taiwanese regular exercisers completed measures, including the Exercise Dependence Scale-Revised, the Exercise Identity Scale, the Exercise Commitment Scale, and the Godin Leisure Time Exercise Questionnaire. Results showed that exercise identity, exercise dependence, and two types of exercise commitment were moderately to highly correlated. Furthermore, structural equation modelling indicated that a "have to" commitment partially mediated the relationship between exercise identity and exercise dependence. Based on the mediating role of a "have to" commitment, the findings are particularly informative to exercise instructors and for exercise program managers.
Full Text Available A set of mediation analyses were carried out in this study using data from It’s Your Game. . .Keep It Real (IYG, a successful HIV/STI/pregnancy prevention program. The IYG study evaluated a skill and normbased. HIV/STI/pregnancy prevention program that was implemented from 2004 to 2007 among 907 urban low-income middle school youth in Houston, TX, USA. Analyses were carried out to investigate the degree to which a set of proposed psychosocial measures of behavioral knowledge, perceived self-efficacy, behavioral, and normative beliefs, and perceived risky situations, all targeted by the intervention, mediated the intervention’s effectiveness in reducing initiation of sex. The mediation process was assessed by examining the significance and size of the estimated effects from the mediating pathways. The findings from this study provide evidence that the majority of the psychosocial mediators targeted by the IYG intervention are indeed related to the desired behavior and provide evidence that the conceptual theory underlying the targeted psychosocial mediators in the intervention is appropriate. Two of the psychosocial mediators significantly mediated the intervention effect, knowledge of STI signs and symptoms and refusal self-efficacy. This study suggests that the underlying causal mechanisms of action of these interventions are complex and warrant further analyses.
Partridge, Stephanie R; McGeechan, Kevin; Bauman, Adrian; Phongsavan, Philayrath; Allman-Farinelli, Margaret
Explanatory evaluation of interventions for prevention of weight gain is required beyond changes in weight, to determine for whom the intervention works and the underlying mechanisms of change. It was hypothesised that participant characteristics moderate intervention effect on weight change and improved eating and physical activity behaviours during the 3-month program mediate the relationship between intervention and weight. In our randomised controlled trial, young adults at risk of weight gain (n = 250) were assigned either to an intervention group that received a 3-month mHealth (TXT2BFiT) program with 6-month maintenance or to a control group. Data were collected via online self-report surveys. Hypothesised moderators and mediators of the intervention effect on weight were independently assessed in PROCESS macro models for 3 and 9-month weight change. Males (P = 0.01), mid-20s age group (P = 0.04), and higher income earners (P = 0.02) moderated intervention effects on weight change at 3-months and males only at 9-months (P = 0.02). Weight change at 3 (-1.12 kg) and 9-months (-1.38 kg) remained significant when 3-month nutrition and physical activity behaviours were specified as mediators (P <0.01 and P = 0.01 respectively). Indirect paths explained 39% (0.72/1.85 kg) and 40 % (0.92/2.3 kg) of total effect on weight change at 3 and 9-months respectively. Increased vegetable intake by intervention group at 3-months accounted for 19 and 17% and decreased sugar-sweetened beverages accounted for 8 and 13% of indirect weight change effects at 3 and 9-months respectively. TXT2BFiT was effective for both young men and women. Small sustained behavioural changes, including increased vegetable intake and decreased sugar-sweetened beverages consumption significantly mediated the intervention's effects on weight change. Improved eating behaviours and increased physical activity accounted for approximately 40% of the weight change. The trial is
Turnuklu, Abbas; Kacmaz, Tarkan; Gurler, Selma; Turk, Fulya; Kalender, Alper; Zengin, Feza; Sevkin, Burcak
The effectiveness of conflict resolution and peer mediation (CRPM) training among 10- and 11-year-old elementary school students was examined. The CRPM training program consisted of skills, such as understanding the nature of interpersonal conflicts, communication, anger management, negotiation and peer mediation. The research was carried out…
Quaresma, A M; Palmeira, A L; Martins, S S; Minderico, C S; Sardinha, L B
The aim of this study was to explore the effects of social support and behavioral regulation of exercise on physical activity (PA) and quality of life (QoL), in a Portuguese school-based intervention. We hypothesized that serial mediation effects would be present leading to greater levels of PA and QoL. The sample comprised 1042 students (549 boys), aged 10-16 years, BMI = 19.31 ± 3.51, allocated to two groups of schools: control (n = 207) and intervention (n = 835). This study will report the 24 months results of the program, which aimed to develop healthy lifestyles. Questionnaires were used to measure PA, QoL, motivation to exercise and social support. There was no direct impact of the intervention on QoL or PA. Serial mediation analyses were conducted. Social support (P motivation (P = 0.085) increased more on intervention group. Indirect effects were observed in all serial mediation models. The positive indirect effects on PA and QoL were explained by the increase on peer/parent support in serial with the increase in intrinsic motivation (P motivation (P school-based intervention promoted the development of social support and motivational mechanisms that explained higher levels of PA and QoL. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please email: firstname.lastname@example.org.
Full Text Available The present research examined the influences of pay for performance programs on employee performance in the Romanian context, by comparing a sample of employees in companies in which such programs are implemented to a sample of employees in organizations in which performance is not used as a criterion in deciding financial rewards. Results show that the work performances of the former, as evaluated by the direct supervisors of each employee, are significantly higher than those of the latter, and that this effect of performance pay is partly mediated by its positive effects on employee perceptions of distributive and procedural justice. Furthermore, results indicate that the individual – level financial incentive systems are more efficient in fostering work performance than the team – level performance pay programs in the Romanian employee sample, and that they also have stronger effects on the two dimensions of organizational justice.
Schimidt, Teresa Cristina Gioia; Duarte, Yeda Aparecida de Oliveira; Silva, Maria Julia Paes da
Replicating the training program in non-verbal communication based on the theoretical framework of interpersonal communication; non-verbal coding, valuing the aging aspects in the perspective of active aging, checking its current relevance through the content assimilation index after 90 days (mediate) of its application. A descriptive and exploratory field study was conducted in three hospitals under direct administration of the state of São Paulo that caters exclusively to Unified Health System (SUS) patients. The training lasted 12 hours divided in three meetings, applied to 102 health professionals. Revealed very satisfactory and satisfactory mediate content assimilation index in 82.9%. The program replication proved to be relevant and updated the setting of hospital services, while remaining efficient for healthcare professionals.
Guagliano, Justin M; Lonsdale, Chris; Rosenkranz, Richard R; Parker, Philip D; Agho, Kingsley E; Kolt, Gregory S
The objective of this study was to test whether coaches' physical activity levels, contextual variables, and coaches' behavioural variables mediated the effect of an intervention on female basketball players' moderate-to-vigorous physical activity (MVPA) and inactivity in an organised youth sport (OYS) setting. Randomised controlled trial Data for the current study were derived from a two-armed, parallel-group randomised controlled trial. This study ran over the course of a 5-day OYS basketball program in 2 sports centres in Sydney, Australia. A convenience sample of 76 female players and 8 coaches were recruited. Coaches allocated to the intervention condition attended 2 coach education sessions, where strategies to increase MVPA and decrease inactivity were taught. There was a significant effect between changes in coach MVPA and player MVPA (unstandardised regression coefficient [B] = 0.26, 95% CI = 0.14 to 0.38) which coincided with a significant indirect effect (B = 1.80, 95% CI = 0.85 to 2.85). There was also a significant effect between changes in coach inactivity and player inactivity (B = -0.23, 95% CI = -0.14 to -0.31), which coincided with a significant indirect effect (B = -3.20, 95% CI = -0.14 to -0.31). No significant indirect effects were found for lesson context and coaches' behaviours variables. Coaches' MVPA and inactivity significantly mediated the effect of the intervention on player MVPA and inactivity, respectively. Consequently, coaches' physical activity levels appear to be important for influencing their players' physical activity levels. Published by Elsevier Ltd.
Spence, Alison C; Campbell, Karen J; Crawford, David A; McNaughton, Sarah A; Hesketh, Kylie D
Young children's diets are currently suboptimal. Given that mothers have a critical influence on children' diets, they are typically a target of interventions to improve early childhood nutrition. Understanding the maternal factors which mediate an intervention's effect on young children's diets is important, but has not been well investigated. This research aimed to test whether maternal feeding knowledge, maternal feeding practices, maternal self-efficacy, and maternal dietary intakes acted as mediators of the effect of an intervention to improve child diet quality. The Melbourne Infant Feeding Activity and Nutrition Trial (InFANT) Program was a cluster-randomized controlled trial, conducted from 2008-2010. This novel, low-dose, health promotion intervention was delivered quarterly over 15 months and involved educational activities, promotion of peer discussion, a DVD and written materials. Post-intervention, when children were approximately 18 months of age, child diets were assessed using multiple 24-hour recalls and a purpose-developed index of diet quality, the Obesity Protective Dietary Index. Maternal mediators were assessed using a combination of previously validated and purpose-deigned tools. Mediation analysis was conducted using the test of joint significance and difference of coefficients methods. Across 62 parents' groups in Melbourne, Australia, 542 parents were recruited. Post- intervention, higher maternal feeding knowledge and lower use of foods as rewards was found to mediate the direct intervention effect on child diet quality. While other aspects of maternal feeding practices, self-efficacy and dietary intakes did not act as mediators, they were associated with child diet quality. Mediation analysis of this novel health promotion intervention showed the importance of maternal feeding knowledge and use of foods as rewards in impacting child diet quality. The other maternal factors assessed were appropriate targets but further research on how to
Wang, Lijuan; Zhang, Zhiyong
This study investigated influences of censored data on mediation analysis. Mediation effect estimates can be biased and inefficient with censoring on any one of the input, mediation, and output variables. A Bayesian Tobit approach was introduced to estimate and test mediation effects with censored data. Simulation results showed that the Bayesian…
Williams, Jason; Herman-Stahl, Mindy; Calvin, Sara L; Pemberton, Michael; Bradshaw, Michael
This study explored the mediating mechanisms of two Web-based alcohol interventions in a sample of active duty United States military personnel. Personnel were recruited from eight bases and received the Drinker's Check-Up (N=1483), Alcohol Savvy (N=688), or served as controls (N=919). The interventions drew on motivational interviewing and social learning theory and targeted multiple mediators including social norms, perceived risks and benefits, readiness to change, and coping strategies. Baseline data were collected prior to the intervention and follow-up data on alcohol consumption were gathered 1 month and 6 months after program completion. Two mediation models were examined: (1) a longitudinal two-wave model with outcomes and mediators assessed concurrently at the 1-month follow-up; and (2) a three-wave model in which the causal chain was fully lagged. Results indicated strong support for the role of perceived descriptive norms in transmitting the effects of the Drinker's Check-Up, with consistent mediation across the majority of alcohol outcome measures for both the concurrent and fully lagged mediation models. These results suggest that web-based interventions that are effective in lowering perceived norms about the frequency and quantity of drinking may be a viable strategy for reducing alcohol consumption in military populations. The results did not support program mediation by the other targeted variables, indicating the need for future research on the effective components of alcohol interventions. The mediation models also suggest reasons why program effects were not found for some outcomes or were different across programs.
Teresa Cristina Gioia Schimidt
Full Text Available OBJECTIVE Replicating the training program in non-verbal communication based on the theoretical framework of interpersonal communication; non-verbal coding, valuing the aging aspects in the perspective of active aging, checking its current relevance through the content assimilation index after 90 days (mediate of its application. METHOD A descriptive and exploratory field study was conducted in three hospitals under direct administration of the state of São Paulo that caters exclusively to Unified Health System (SUS patients. The training lasted 12 hours divided in three meetings, applied to 102 health professionals. RESULTS Revealed very satisfactory and satisfactory mediate content assimilation index in 82.9%. CONCLUSION The program replication proved to be relevant and updated the setting of hospital services, while remaining efficient for healthcare professionals.
Saunders, Christina T; Blume, Jeffrey D
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.
Miočević, Milica; O'Rourke, Holly P; MacKinnon, David P; Brown, Hendricks C
This project examined the performance of classical and Bayesian estimators of four effect size measures for the indirect effect in a single-mediator model and a two-mediator model. Compared to the proportion and ratio mediation effect sizes, standardized mediation effect-size measures were relatively unbiased and efficient in the single-mediator model and the two-mediator model. Percentile and bias-corrected bootstrap interval estimates of ab/s Y , and ab(s X )/s Y in the single-mediator model outperformed interval estimates of the proportion and ratio effect sizes in terms of power, Type I error rate, coverage, imbalance, and interval width. For the two-mediator model, standardized effect-size measures were superior to the proportion and ratio effect-size measures. Furthermore, it was found that Bayesian point and interval summaries of posterior distributions of standardized effect-size measures reduced excessive relative bias for certain parameter combinations. The standardized effect-size measures are the best effect-size measures for quantifying mediated effects.
Choi, Han Gyo; Ahn, Sung Hee
The aim of this study was to examine the mediating effect of empowerment in the relationship of nurse managers' authentic leadership, with nurses' organizational commitment and job satisfaction. The participants in this study were 273 registered nurses working in five University hospitals located in Seoul and Gyeonggi Province. The measurements included the Authentic Leadership Questionnaire, Condition of Work Effectiveness Questionnaire-II, Organizational Commitment Questionnaire and Korea-Minnesota Satisfaction Questionnaire. Data were analyzed using t-test, ANOVA, Scheffé test, Pearson correlation coefficients, simple and multiple regression techniques with the SPSS 18.0 program. Mediation analysis was performed according to the Baron and Kenny method and Sobel test. There were significant correlations among authentic leadership, empowerment, organizational commitment and job satisfaction. Empowerment showed perfect mediating effects in the relationship between authentic leadership and organizational commitment. It had partial mediating effects in the relationship between authentic leadership and job satisfaction. In this study, nurse managers' authentic leadership had significant influences on nurses organizational commitment and job satisfaction via empowerment. Therefore, to enhance nurses' organizational commitment and job satisfaction, it is necessary to build effective strategies to enhance nurse manager's authentic leadership and to develop empowering education programs for nurses.
Sandler, Irwin; Tein, Jenn-Yun; Cham, Heining; Wolchik, Sharlene; Ayers, Tim
This study reports on the findings from a 6-year follow-up of a randomized trial of the Family Bereavement Program (FBP) on the outcomes for spousally bereaved parents. Spousally bereaved parents (N = 131) participated in the trial in which they were randomly assigned to receive the FBP (N = 72) or literature control (N = 59). Parents were assessed at four time points: pretest, posttest, and 11-month and 6-year follow-up. They reported on mental health problems, grief, and parenting at all four time periods. At the 6-year follow-up, parents reported on additional measures of persistent complex bereavement disorder, alcohol abuse problems, and coping efficacy. Bereaved parents in the FBP as compared to those in the literature control had lower levels of symptoms of depression, general psychiatric distress, prolonged grief, and alcohol problems, and higher coping efficacy (for mothers) at the 6-year follow-up. Multiple characteristics of the parent (e.g., gender, age, and baseline mental health problems) and of the spousal death (e.g., cause of death) were tested as moderators of program effects on each outcome, but only 3 of 45 tests of moderation were significant. Latent growth modeling found that the effects of the FBP on depression, psychiatric distress, and grief occurred immediately following program participation and were maintained over 6 years. Mediation analysis found that improvement in positive parenting partially mediated program effects to reduce depression and psychiatric distress, but had an indirect effect to higher levels of grief at the 6-year follow-up. Mediation analysis also found that improved parenting at the 6-year follow-up was partially mediated by program effects to reduce depression and that program effects to increase coping efficacy at the 6-year follow-up was partially mediated through reduced depression and grief and improved parenting. FBP reduced mental health problems, prolonged grief, and alcohol abuse, and increased coping
Sigal, Amanda B; Wolchik, Sharlene A; Tein, Jenn-Yun; Sandler, Irwin N
This study examined whether the New Beginnings Program for divorced families led to improvements in youth's educational goals and job aspirations 6 years following participation and tested whether several parenting and youth variables mediated the program effects. Participants were 240 youth aged 9 to 12 years at the initial assessment, and data were part of a randomized, experimental trial of a parenting skills preventive intervention targeting children's postdivorce adjustment. The results revealed positive effects of the program on youth's educational goals and job aspirations 6 years after participation for those who were at high risk for developing later problems at program entry. Further, intervention-induced changes in mother-child relationship quality and youth externalizing problems, internalizing problems, self-esteem, and academic competence at the 6-year follow-up mediated the effects of the program on the educational expectations of high-risk youth. Intervention-induced changes in youth externalizing problems and academic competence at the 6-year follow-up mediated the effects of the program on the job aspirations of high-risk youth.
Nguyen, Quynh C; Osypuk, Theresa L; Schmidt, Nicole M; Glymour, M Maria; Tchetgen Tchetgen, Eric J
Despite the recent flourishing of mediation analysis techniques, many modern approaches are difficult to implement or applicable to only a restricted range of regression models. This report provides practical guidance for implementing a new technique utilizing inverse odds ratio weighting (IORW) to estimate natural direct and indirect effects for mediation analyses. IORW takes advantage of the odds ratio's invariance property and condenses information on the odds ratio for the relationship between the exposure (treatment) and multiple mediators, conditional on covariates, by regressing exposure on mediators and covariates. The inverse of the covariate-adjusted exposure-mediator odds ratio association is used to weight the primary analytical regression of the outcome on treatment. The treatment coefficient in such a weighted regression estimates the natural direct effect of treatment on the outcome, and indirect effects are identified by subtracting direct effects from total effects. Weighting renders treatment and mediators independent, thereby deactivating indirect pathways of the mediators. This new mediation technique accommodates multiple discrete or continuous mediators. IORW is easily implemented and is appropriate for any standard regression model, including quantile regression and survival analysis. An empirical example is given using data from the Moving to Opportunity (1994-2002) experiment, testing whether neighborhood context mediated the effects of a housing voucher program on obesity. Relevant Stata code (StataCorp LP, College Station, Texas) is provided. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: email@example.com.
Morehead, Kayla; Dunlosky, John; Rawson, Katherine A; Bishop, Melissa; Pyc, Mary A
When study is spaced across sessions (versus massed within a single session), final performance is greater after spacing. This spacing effect may have multiple causes, and according to the mediator hypothesis, part of the effect can be explained by the use of mediator-based strategies. This hypothesis proposes that when study is spaced across sessions, rather than massed within a session, more mediators will be generated that are longer lasting and hence more mediators will be available to support criterion recall. In two experiments, participants were randomly assigned to study paired associates using either a spaced or massed schedule. They reported strategy use for each item during study trials and during the final test. Consistent with the mediator hypothesis, participants who had spaced (as compared to massed) practice reported using more mediators on the final test. This use of effective mediators also statistically accounted for some - but not all of - the spacing effect on final performance.
Stapleton, Laura M.; Pituch, Keenan A.; Dion, Eric
This article presents 3 standardized effect size measures to use when sharing results of an analysis of mediation of treatment effects for cluster-randomized trials. The authors discuss 3 examples of mediation analysis (upper-level mediation, cross-level mediation, and cross-level mediation with a contextual effect) with demonstration of the…
VanderWeele, T J; Vansteelandt, S
Recent advances in the causal inference literature on mediation have extended traditional approaches to direct and indirect effects to settings that allow for interactions and non-linearities. In this paper, these approaches from causal inference are further extended to settings in which multiple mediators may be of interest. Two analytic approaches, one based on regression and one based on weighting are proposed to estimate the effect mediated through multiple mediators and the effects through other pathways. The approaches proposed here accommodate exposure-mediator interactions and, to a certain extent, mediator-mediator interactions as well. The methods handle binary or continuous mediators and binary, continuous or count outcomes. When the mediators affect one another, the strategy of trying to assess direct and indirect effects one mediator at a time will in general fail; the approach given in this paper can still be used. A characterization is moreover given as to when the sum of the mediated effects for multiple mediators considered separately will be equal to the mediated effect of all of the mediators considered jointly. The approach proposed in this paper is robust to unmeasured common causes of two or more mediators.
Cheong, JeeWon; MacKinnon, David P.; Khoo, Siek Toon
This study investigated a method to evaluate mediational processes using latent growth curve modeling. The mediator and the outcome measured across multiple time points were viewed as 2 separate parallel processes. The mediational process was defined as the independent variable influencing the growth of the mediator, which, in turn, affected the growth of the outcome. To illustrate modeling procedures, empirical data from a longitudinal drug prevention program, Adolescents Training and Learning to Avoid Steroids, were used. The program effects on the growth of the mediator and the growth of the outcome were examined first in a 2-group structural equation model. The mediational process was then modeled and tested in a parallel process latent growth curve model by relating the prevention program condition, the growth rate factor of the mediator, and the growth rate factor of the outcome. PMID:20157639
Preacher, Kristopher J.; Kelley, Ken
The statistical analysis of mediation effects has become an indispensable tool for helping scientists investigate processes thought to be causal. Yet, in spite of many recent advances in the estimation and testing of mediation effects, little attention has been given to methods for communicating effect size and the practical importance of those…
Zhang, Tie-Yuan; Bagot, Rose; Parent, Carine; Nesbitt, Cathy; Bredy, Timothy W; Caldji, Christian; Fish, Eric; Anisman, Hymie; Szyf, Moshe; Meaney, Michael J
There are profound maternal effects on individual differences in defensive responses and reproductive strategies in species ranging literally from plants to insects to birds. Maternal effects commonly reflect the quality of the environment and are most likely mediated by the quality of the maternal provision (egg, propagule, etc.), which in turn determines growth rates and adult phenotype. In this paper we review data from the rat that suggest comparable forms of maternal effects on defensive responses stress, which are mediated by the effects of variations in maternal behavior on gene expression. Under conditions of environmental adversity maternal effects enhance the capacity for defensive responses in the offspring. In mammals, these effects appear to 'program' emotional, cognitive and endocrine systems towards increased sensitivity to adversity. In environments with an increased level of adversity, such effects can be considered adaptive, enhancing the probability of offspring survival to sexual maturity; the cost is that of an increased risk for multiple forms of pathology in later life.
Stigler, Melissa Harrell; Perry, Cheryl L.; Smolenski, Derek; Arora, Monika; Reddy, K. Srinath
This article presents the results of a mediation analysis of Project MYTRI (Mobilizing Youth for Tobacco Related Initiatives in India), a randomized, controlled trial of a multiple-component, school-based tobacco prevention program for sixth- to ninth-graders (n = 14,085) in Delhi and Chennai, India. A mediation analysis identifies "how"…
Wang, Jian; Shete, Sanjay
A mediation model explores the direct and indirect effects of an initial variable ( X) on an outcome variable ( Y) by including a mediator ( M). In many realistic scenarios, investigators observe censored data instead of the complete data. Current research in mediation analysis for censored data focuses mainly on censored outcomes, but not censored mediators. In this study, we proposed a strategy based on the accelerated failure time model and a multiple imputation approach. We adapted a measure of the indirect effect for the mediation model with a censored mediator, which can assess the indirect effect at both the group and individual levels. Based on simulation, we established the bias in the estimations of different paths (i.e. the effects of X on M [ a], of M on Y [ b] and of X on Y given mediator M [ c']) and indirect effects when analyzing the data using the existing approaches, including a naïve approach implemented in software such as Mplus, complete-case analysis, and the Tobit mediation model. We conducted simulation studies to investigate the performance of the proposed strategy compared to that of the existing approaches. The proposed strategy accurately estimates the coefficients of different paths, indirect effects and percentages of the total effects mediated. We applied these mediation approaches to the study of SNPs, age at menopause and fasting glucose levels. Our results indicate that there is no indirect effect of association between SNPs and fasting glucose level that is mediated through the age at menopause.
Sigal, Amanda B.; Wolchik, Sharlene A.; Tein, Jenn-Yun; Sandler, Irwin N.
This study examined whether the New Beginnings Program for divorced families led to improvements in youth’s educational goals and job aspirations six years following participation and tested whether several parenting and youth variables mediated the program effects. Participants were 240 youth aged 9–12 years at the initial assessment, and data were part of a randomized, experimental trial of a parenting skills preventive intervention targeting children’s post-divorce adjustment. The results revealed positive effects of the program on youth’s educational goals and job aspirations six years after participation for those who were at high risk for developing later problems at program entry. Further, intervention-induced changes in mother-child relationship quality and youth externalizing problems, internalizing problems, self-esteem, and academic competence at the six-year follow-up mediated the effects of the program on the educational expectations of high-risk youth. Intervention-induced changes in youth externalizing problems and academic competence at the six-year follow-up mediated the effects of the program on the job aspirations of high-risk youth. Implications of the present findings for research with youth from divorced families and for the public health burden of divorce are discussed. PMID:22417189
Due to unsatisfactory number of researches investigating ELT post-graduate programs, and perceptions of academics and students in these programs regarding mediation theory of Feuerstein, this study attempted to investigate the aspects of this theory in doctorate and master programs in ELT department of a state university. Methodologically, this…
Full Text Available Abstract Background Although it is important to investigate how interventions work, no formal mediation analyses have been conducted to explain behavioral outcomes in school-based fat intake interventions in adolescents. The aim of the present study was to examine mediation effects of changes in psychosocial determinants of dietary fat intake (attitude, social support, self-efficacy, perceived benefits and barriers on changes in fat intake in adolescent girls. Methods Data from a 1-year prospective intervention study were used. A random sample of 804 adolescent girls was included in the study. Girls in the intervention group (n = 415 were exposed to a multi-component school-based intervention program, combining environmental changes with a computer tailored fat intake intervention and parental support. Fat intake and psychosocial determinants of fat intake were measured with validated self-administered questionnaires. To assess mediating effects, a product-of-coefficient test, appropriate for cluster randomized controlled trials, was used. Results None of the examined psychosocial factors showed a reliable mediating effect on changes in fat intake. The single-mediator model revealed a statistically significant suppression effect of perceived barriers on changes in fat intake (p = 0.011. In the multiple-mediator model, this effect was no longer significant, which was most likely due to changes in perceived barriers being moderately related to changes in self-efficacy (-0.30 and attitude (-0.25. The overall mediated-suppressed effect of the examined psychosocial factors was virtually zero (total mediated effect = 0.001; SE = 7.22; p = 0.992. Conclusion Given the lack of intervention effects on attitudes, social support, self-efficacy and perceived benefits and barriers, it is suggested that future interventions should focus on the identification of effective strategies for changing these theoretical mediators in the desired direction
Full Text Available Understanding the mechanisms of androgen receptor (AR activation in the milieu of low androgen is critical to effective treatment of castration-resistant prostate cancer (CRPC. Here, we report HOTAIR as an androgen-repressed lncRNA, and, as such, it is markedly upregulated following androgen deprivation therapies and in CRPC. We further demonstrate a distinct mode of lncRNA-mediated gene regulation, wherein HOTAIR binds to the AR protein to block its interaction with the E3 ubiquitin ligase MDM2, thereby preventing AR ubiquitination and protein degradation. Consequently, HOTAIR expression is sufficient to induce androgen-independent AR activation and drive the AR-mediated transcriptional program in the absence of androgen. Functionally, HOTAIR overexpression increases, whereas HOTAIR knockdown decreases, prostate cancer cell growth and invasion. Taken together, our results provide compelling evidence of lncRNAs as drivers of androgen-independent AR activity and CRPC progression, and they support the potential of lncRNAs as therapeutic targets.
Jensen, Jakob D; King, Andy J; Carcioppolo, Nicholas; Davis, LaShara
Past research has found that tailoring increases the persuasive effectiveness of a message. However, the observed effect has been small and the explanatory mechanism remains unknown. To address these shortcomings, a tailoring software program was created that personalized breast cancer screening pamphlets according to risk, health belief model constructs, and visual preference. Women aged 40 and older ( N = 119) participated in a 2 (tailored vs. stock message) × 2 (charts/graphs vs. illustrated visuals) × 3 (nested replications of the visuals) experiment. Participants provided with tailored illustrated pamphlets expressed greater breast cancer screening intentions than those provided with other pamphlets. In a test of 10 different mediators, perceived message relevance was found to fully mediate the tailoring × visual interaction.
Bellavia, Andrea; Valeri, Linda
Mediation analysis allows decomposing a total effect into a direct effect of the exposure on the outcome and an indirect effect operating through a number of possible hypothesized pathways. Recent studies have provided formal definitions of direct and indirect effects when multiple mediators are of interest and have described parametric and semiparametric methods for their estimation. Investigating direct and indirect effects with multiple mediators, however, can be challenging in the presence of multiple exposure-mediator and mediator-mediator interactions. In this paper we derive a decomposition of the total effect that unifies mediation and interaction when multiple mediators are present. We illustrate the properties of the proposed framework in a secondary analysis of a pragmatic trial for the treatment of schizophrenia. The decomposition is employed to investigate the interplay of side effects and psychiatric symptoms in explaining the effect of antipsychotic medication on quality of life in schizophrenia patients. Our result offers a valuable tool to identify the proportions of total effect due to mediation and interaction when more than one mediator is present, providing the finest decomposition of the total effect that unifies multiple mediators and interactions.
Király, Orsolya; Urbán, Róbert; Griffiths, Mark D; Ágoston, Csilla; Nagygyörgy, Katalin; Kökönyei, Gyöngyi; Demetrovics, Zsolt
The rapid expansion of online video gaming as a leisure time activity has led to the appearance of problematic online gaming (POG). According to the literature, POG is associated with different psychiatric symptoms (eg, depression, anxiety) and with specific gaming motives (ie, escape, achievement). Based on studies of alcohol use that suggest a mediator role of drinking motives between distal influences (eg, trauma symptoms) and drinking problems, this study examined the assumption that there is an indirect link between psychiatric distress and POG via the mediation of gaming motives. Furthermore, it was also assumed that there was a moderator effect of gender and game type preference based on the important role gender plays in POG and the structural differences between different game types. This study had two aims. The first aim was to test the mediating role of online gaming motives between psychiatric symptoms and problematic use of online games. The second aim was to test the moderator effect of gender and game type preference in this mediation model. An online survey was conducted on a sample of online gamers (N=3186; age: mean 21.1, SD 5.9 years; male: 2859/3186, 89.74%). The Brief Symptom Inventory (BSI), the Motives for Online Gaming Questionnaire (MOGQ), and the Problematic Online Gaming Questionnaire (POGQ) were administered to assess general psychiatric distress, online gaming motives, and problematic online game use, respectively. Structural regression analyses within structural equation modeling were used to test the proposed mediation models and multigroup analyses were used to test gender and game type differences to determine possible moderating effects. The mediation models fitted the data adequately. The Global Severity Index (GSI) of the BSI indicated that the level of psychiatric distress had a significant positive direct effect (standardized effect=.35, Pgaming motives: escape (standardized effect=.139, Pgaming (standardized effect size=.64
Mehta, Sagar; Shah, Devesh; Shah, Kushal; Mehta, Sanjiv; Mehta, Neelam; Mehta, Vivek; Mehta, Vijay; Mehta, Vaishali; Motiwala, Smita; Mehta, Naina; Mehta, Devendra
The objective was to assess the efficacy of a one-year, peer-mediated interventional program consisting of yoga, meditation and play therapy maintained by student volunteers in a school in India. The population consisted of 69 students between the ages of 6 and 11 years, previously identified as having attention deficit hyperactivity disorder (ADHD). A program, known as Climb-Up, was initially embedded in the school twice weekly. Local high school student volunteers were then trained to continue to implement the program weekly over the period of one year. Improvements in ADHD symptoms and academic performance were assessed using Vanderbilt questionnaires completed by both parents and teachers. The performance impairment scores for ADHD students assessed by teachers improved by 6 weeks and were sustained through 12 months in 46 (85%) of the enrolled students. The improvements in their Vanderbilt scores assessed by parents were also seen in 92% (P < 0.0001, Wilcoxon). The Climb-Up program resulted in remarkable improvements in the students' school performances that were sustained throughout the year. These results show promise for a cost-effective program that could easily be implemented in any school. PMID:23316384
Storrow, Rebecca A.
Florida family court mediation programs have typically been assessed with quantitative analysis. To understand the complexity of the experience of being a family mediator, it was necessary to explore how mediators practiced through qualitative research. Metaphors have been considered to be representations of mediators' mental models regarding…
SEM indicated a significant effect of sports participation on Internet addiction mediated by self-control. The results suggest the effectiveness of and need for sport and physical activity in Internet addiction treatment programs and for other addictions as well. Moreover, sports participation has a wider variety of psychological and physical benefits unlike intervention strategies or pharmacological treatments. Thus, the adoption of sports needs to be broadened from physical development to treating diverse psychological problems among adolescents.
Suk, Min Hyun; Oh, Won Oak; Im, Yeo Jin; Cho, Hun Ha
This study examined the mediating effect of school nurses' self efficacy, which is one of the significant cognitive factors influencing cultural sensitivity, on the mutual relationships between multicultural attitude and cultural sensitivity in Korean elementary schools. A cross-sectional descriptive survey design was used. Participants were 157 school nurses in elementary schools located in Gyeonggi-do, South Korea. The survey instruments included Teacher Multicultural Attitude Survey, Teacher Efficacy Scale, and Multicultural Sensitivity Scale. Data were analyzed using three regression equations to test the mediation model. The mean score of the school nurses' cultural sensitivity was relatively low. A positive correlation among multicultural attitude, self efficacy, and cultural sensitivity was noted. Self efficacy of school nurses showed a significant mediating effect on the relationships between multicultural attitude and cultural sensitivity. Given the meaningful influence of positive multicultural attitude on cultural sensitivity and significant mediator effect of self efficacy as a school nurse between the two variables, the strategies to cultivate a positive multicultural attitude and enhance school nurses' self efficacy in their unique role should be considered in a training program. School nurses' health care services will benefit from the improvement of cultural sensitivity toward young children from multicultural families. Copyright © 2015. Published by Elsevier B.V.
Jensen, M.; Wong, J.J.; Gonzales, N.A.; Dumka, L.E.; Millsap, R.; Coxe, S.
Objective This randomized trial of a family-focused preventive intervention for Mexican American middle schoolers examined internalizing, externalizing, and substance use outcomes in late adolescence, five years after completing the intervention. Parent-adolescent conflict was tested as a mediator of these effects. The role of parent and adolescent acculturation in these pathways was also examined. Method 498 7th grade adolescents and their primary female caregivers were randomized to receive either a 9-week, multi-component intervention or a brief workshop control group. Assessments were conducted at pre-test, two year follow-up (9th grade), and five year follow-up (when most participants were in the 12th grade). Results The Bridges program significantly reduced mother-adolescent conflict measured in the 9th grade, with conflict mediating program effects on internalizing and externalizing symptoms, adolescent substance use, and diagnosed internalizing disorder in late adolescence. Mother and child acculturation were both significantly predictive of late adolescence outcomes. Contrary to hypotheses, neither mother nor child acculturation emerged as a significant predictor of mother-adolescent conflict, and the interaction of mother and adolescent acculturation was similarly not related to mother-adolescent conflict. Intervention effects were largely consistent across different levels of acculturation. Conclusions These findings provide support for the efficacy of family-focused intervention during early adolescence, both in reducing mental health problems and substance use in the long term, as well as in impacting parent-adolescent conflict processes that appear to play an important role in the development of later adjustment problems. PMID:24730357
McKenzie, Donna Margaret
Stress triggered by workplace-based interpersonal conflict can result in damaged relationships, loss of productivity, diminished job satisfaction and increasingly, workers' compensation claims for psychological injury. This paper examined the literature on the role and effectiveness of mediation, as the most common method of Alternative Dispute Resolution, in resolving workplace relationship conflict. Available evidence suggests that mediation is most effective when supported by organisational commitment to ADR strategies, policies and processes, and conducted by independent, experienced and qualified mediators. The United States Postal Service program REDRESS™ is described as an illustration of the successful use of mediation to resolve conflict in the workplace. Copyright © 2015 Elsevier Ltd. All rights reserved.
Heo, YoungJin; Lee, Kyunghee
Previous studies have reported associations among smartphone addiction, school adjustment, and self-control. However, the causal relationship between smartphone addiction and school adjustment has not been clearly demonstrated. The current study examined the association between smartphone addiction and school adjustment and investigated the mediating effect of self-control in this association. A total of 790 students from five high schools in Daegu City, South Korea, were asked to provide demographic information and complete a self-diagnostic smartphone addiction scale and validated Korean version of a self-control scale. Among at-risk students, self-control did not mediate the relation between smartphone addiction and school adjustment; among those not at risk, there was a partial mediating effect. To improve school adjustment among high school students, prevention of smartphone addiction seems important. Smartphone addiction could be managed by strengthening self-control to promote healthy use of smartphones. The current results can serve as groundwork for the development of programs to improve school adjustment among high school students. [Journal of Psychosocial Nursing and Mental Health Services, xx(x), xx-xx.]. Copyright 2018, SLACK Incorporated.
VanderWeele, T.J.; Vansteelandt, S.
Recent advances in the causal inference literature on mediation have extended traditional approaches to direct and indirect effects to settings that allow for interactions and non-linearities. In this paper, these approaches from causal inference are further extended to settings in which multiple mediators may be of interest. Two analytic approaches, one based on regression and one based on weighting are proposed to estimate the effect mediated through multiple mediators and the effects throu...
Wearden, Alison J; Emsley, Richard
To examine potential mediators of the effect of pragmatic rehabilitation on improvements in fatigue following a randomized controlled trial for patients with chronic fatigue syndrome (CFS/ME) in primary care (IRCTN 74156610). Patients fulfilled the Oxford criteria for CFS. Ninety-five patients were randomized to pragmatic rehabilitation and 100 to general practitioner (GP) treatment as usual. The outcome was the Chalder fatigue scale score (0123 scoring) at end of treatment (20 weeks) and 1-year follow up (70 weeks). First, the effect of treatment on potential mediators was assessed. Then fatigue was regressed on significant mediators, treatment allocation, and baseline measures of fatigue and significant mediators. Reduction in limiting activities at 20 weeks mediated the positive effect of pragmatic rehabilitation on fatigue at 70 weeks (mediated effect size = -2.64, SE = 0.81, p = .001, proportion of effect mediated = 82.0%). Reduction in catastrophizing at 20 weeks mediated the positive effect of pragmatic rehabilitation on fatigue at 70 weeks (mediated effect size = -1.39, SE = 0.61, p = .023, proportion of effect mediated = 43.2%). Reductions in 70-week measures of fear avoidance, embarrassment avoidance, limiting activities, and all-or-nothing behavior all mediated improvement in fatigue at 70 weeks, although the causal direction of these cross-sectional effects cannot be determined. There were no between-group differences on measures of exercise capacity (a timed step test). Improvements in fatigue following pragmatic rehabilitation are related to changes in behavioral responses to and beliefs about fatigue.
Gonzálvez, María T; Morales, Alexandra; Orgilés, Mireia; Sussman, Steve; Espada, José P
Although some school-based tobacco cessation and prevention programs have been proven to be effective, there remains a lack of understanding of how these programs succeed. This longitudinal study aimed to test smoking intention as a mediator of Project EX's intervention efficacy to reduce tobacco use. Using a computerized random number generator, six high schools located in the Mediterranean coast were randomly selected to participate in the program condition (Spanish version of Project EX) or the waiting-list control group with baseline, immediate-posttest, and 12-month follow-up assessments. At baseline, 685 adolescents aged 14-20 years (mean age: 14.87; SD = 0.92; 47.4% were females) were evaluated using self-administered tests of tobacco, and smoking intention. A biomarker of smoke inhalation, a measurement of exhaled carbon monoxide (ECM), was used. Mediation analyses were conducted using the PROCESS v2.12 macro for Windows. Project EX had a significant effect on smoking intention. Indirect effects indicated that Project EX reduced the ECM level, and number of cigarettes used. This is the first Spanish study that explored intention as a mediator of the long-term efficacy of Project EX to reduce tobacco use in adolescents. Results suggested that interventions that reduce consumption intention at short-term are more likely to be successful in decreasing tobacco use in the long-term. Copyright © 2018 Elsevier Ltd. All rights reserved.
Full Text Available Transporters are important mediators of specific cellular uptake and thus, not only for effects, but also for side effects, metabolism, and excretion of many drugs such as cisplatin. Cisplatin is a potent cytostatic drug, whose use is limited by its severe acute and chronic nephro-, oto-, and peripheral neurotoxicity. For this reason, other platinum derivatives, such as carboplatin and oxaliplatin, with less toxicity but still with antitumoral action have been developed. Several transporters, which are expressed on the cell membranes, have been associated with cisplatin transport across the plasma membrane and across the cell: the copper transporter 1 (Ctr1, the copper transporter 2 (Ctr2, the P-type copper-transporting ATPases ATP7A and ATP7B, the organic cation transporter 2 (OCT2, and the multidrug extrusion transporter 1 (MATE1. Some of these transporters are also able to accept other platinum derivatives as substrate. Since membrane transporters display a specific tissue distribution, they can be important molecules that mediate the entry of platinum derivatives in target and also nontarget cells possibly mediating specific effects and side effects of the chemotherapeutic drug. This paper summarizes the literature on toxicities of cisplatin compared to that of carboplatin and oxaliplatin and the interaction of these platinum derivatives with membrane transporters.
Park, Soojin; Steiner, Peter M; Kaplan, David
Considering that causal mechanisms unfold over time, it is important to investigate the mechanisms over time, taking into account the time-varying features of treatments and mediators. However, identification of the average causal mediation effect in the presence of time-varying treatments and mediators is often complicated by time-varying confounding. This article aims to provide a novel approach to uncovering causal mechanisms in time-varying treatments and mediators in the presence of time-varying confounding. We provide different strategies for identification and sensitivity analysis under homogeneous and heterogeneous effects. Homogeneous effects are those in which each individual experiences the same effect, and heterogeneous effects are those in which the effects vary over individuals. Most importantly, we provide an alternative definition of average causal mediation effects that evaluates a partial mediation effect; the effect that is mediated by paths other than through an intermediate confounding variable. We argue that this alternative definition allows us to better assess at least a part of the mediated effect and provides meaningful and unique interpretations. A case study using ECLS-K data that evaluates kindergarten retention policy is offered to illustrate our proposed approach.
Smith, Jordan J; Morgan, Philip J; Plotnikoff, Ronald C; Stodden, David F; Lubans, David R
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.
Taguri, Masataka; Featherstone, John; Cheng, Jing
In many health studies, researchers are interested in estimating the treatment effects on the outcome around and through an intermediate variable. Such causal mediation analyses aim to understand the mechanisms that explain the treatment effect. Although multiple mediators are often involved in real studies, most of the literature considered mediation analyses with one mediator at a time. In this article, we consider mediation analyses when there are causally non-ordered multiple mediators. Even if the mediators do not affect each other, the sum of two indirect effects through the two mediators considered separately may diverge from the joint natural indirect effect when there are additive interactions between the effects of the two mediators on the outcome. Therefore, we derive an equation for the joint natural indirect effect based on the individual mediation effects and their interactive effect, which helps us understand how the mediation effect works through the two mediators and relative contributions of the mediators and their interaction. We also discuss an extension for three mediators. The proposed method is illustrated using data from a randomized trial on the prevention of dental caries.
... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Mediation of amendments. 923.83... Programs § 923.83 Mediation of amendments. (a) Section 307(h)(2) of the Act provides for mediation of... management program. Accordingly mediation is available to states or federal agencies when a serious...
Preacher, Kristopher J; Hayes, Andrew F
Researchers often conduct mediation analysis in order to indirectly assess the effect of a proposed cause on some outcome through a proposed mediator. The utility of mediation analysis stems from its ability to go beyond the merely descriptive to a more functional understanding of the relationships among variables. A necessary component of mediation is a statistically and practically significant indirect effect. Although mediation hypotheses are frequently explored in psychological research, formal significance tests of indirect effects are rarely conducted. After a brief overview of mediation, we argue the importance of directly testing the significance of indirect effects and provide SPSS and SAS macros that facilitate estimation of the indirect effect with a normal theory approach and a bootstrap approach to obtaining confidence intervals, as well as the traditional approach advocated by Baron and Kenny (1986). We hope that this discussion and the macros will enhance the frequency of formal mediation tests in the psychology literature. Electronic copies of these macros may be downloaded from the Psychonomic Society's Web archive at www.psychonomic.org/archive/.
Jo, Booil; Stuart, Elizabeth A.
The authors thank Dr. Lindsay Page for providing a nice illustration of the use of the principal stratification framework to define causal effects, and a Bayesian model for effect estimation. They hope that her well-written article will help expose education researchers to these concepts and methods, and move the field of mediation analysis in…
Hsu, Yawen; Alfermann, Dorothee; Lu, Frank J H; Lin, Linda L
Fear of falling leads to many adverse consequences and may compromise the quality of life of older adults. Psychological factors are potential mediators between the fear of falling and quality of life, but have yet to be explored in detail. This study presents results from examining the mediating effect of the self-concept of health and physical independence. Data from Western and Eastern countries were compared. Concerns about falling, the level of participation in physical activities, the self-concept of health and physical independence, and health-related quality of life were measured using samples from Taiwan (n = 193) and Germany (n = 182). Multiple regression models were used to test the mediating effects. The relationship between fear of falling and quality of life was partially mediated through participation in physical activities and the self-concept of health and physical independence in both the Taiwanese and German samples. In particular, the self-concept of health and physical independence of the Taiwanese sample resulted in the strongest mediating effect. Potential mediating mechanisms through both participation in physical activities and the self-concept of health and physical independence provide useful information for understanding related theories and for explicating interventions. Cultural factors should also be accounted for when conducting research and programs related to the fear of falling.
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
Nima, Ali Al; Rosenberg, Patricia; Archer, Trevor; Garcia, Danilo
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.
Liu, Lu; Haque, M. D.
This study identified the moderated mediation relationship among age, Internet self-efficacy, and statistics anxiety on student satisfaction after controlling for demographics and technology experiences in research methods courses in a blended professional doctoral program. One hundred and thirty-one students in a three-year Ed.D. Program…
Király, Orsolya; Urbán, Róbert; Griffiths, Mark D; Ágoston, Csilla; Nagygyörgy, Katalin; Kökönyei, Gyöngyi
Background The rapid expansion of online video gaming as a leisure time activity has led to the appearance of problematic online gaming (POG). According to the literature, POG is associated with different psychiatric symptoms (eg, depression, anxiety) and with specific gaming motives (ie, escape, achievement). Based on studies of alcohol use that suggest a mediator role of drinking motives between distal influences (eg, trauma symptoms) and drinking problems, this study examined the assumption that there is an indirect link between psychiatric distress and POG via the mediation of gaming motives. Furthermore, it was also assumed that there was a moderator effect of gender and game type preference based on the important role gender plays in POG and the structural differences between different game types. Objective This study had two aims. The first aim was to test the mediating role of online gaming motives between psychiatric symptoms and problematic use of online games. The second aim was to test the moderator effect of gender and game type preference in this mediation model. Methods An online survey was conducted on a sample of online gamers (N=3186; age: mean 21.1, SD 5.9 years; male: 2859/3186, 89.74%). The Brief Symptom Inventory (BSI), the Motives for Online Gaming Questionnaire (MOGQ), and the Problematic Online Gaming Questionnaire (POGQ) were administered to assess general psychiatric distress, online gaming motives, and problematic online game use, respectively. Structural regression analyses within structural equation modeling were used to test the proposed mediation models and multigroup analyses were used to test gender and game type differences to determine possible moderating effects. Results The mediation models fitted the data adequately. The Global Severity Index (GSI) of the BSI indicated that the level of psychiatric distress had a significant positive direct effect (standardized effect=.35, Pgaming motives: escape (standardized effect=.139
Nakagami, Eri; Xie, Bin; Hoe, Maanse; Brekke, John S
This study examined the nature of the relationships among neurocognition, intrinsic motivation, and psychosocial functioning for persons with schizophrenia. Hypotheses concerning both mediator and moderator mechanisms were tested. 120 individuals diagnosed with schizophrenia were recruited as they entered outpatient psychosocial rehabilitation programs. Measures of psychosocial functioning and intrinsic motivation were administered at baseline. Measures of neurocognition were administered at baseline by testers blind to scores on other study variables. Data were analyzed using latent construct modeling to test for mediator and moderator effects. There were strong bivariate relationships between neurocognition, intrinsic motivation, and psychosocial functioning. The results demonstrated that intrinsic motivation strongly mediated the relationship between neurocognition and psychosocial functioning. This mediation was evidenced by: (i) the direct path from neurocognition to functional outcome no longer being statistically significant after the introduction of motivation into the model, (ii) the statistical significance of the indirect path from neurocognition through motivation to functional outcome. There was no support for the two moderation hypotheses: the level of neurocognition did not influence the relationship between intrinsic motivation and psychosocial functioning, nor did the level of intrinsic motivation influence the relationship between neurocognition and psychosocial functioning. Neurocognition influences psychosocial functioning through its relationship with intrinsic motivation. Intrinsic motivation is a critical mechanism for explaining the relationship between neurocognition and psychosocial functioning. Implications for the theoretical understanding and psychosocial treatment of intrinsic motivation in schizophrenia are discussed.
... 7 Agriculture 7 2010-01-01 2010-01-01 false Fees for mediation services. 785.5 Section 785.5... AGRICULTURE SPECIAL PROGRAMS CERTIFIED STATE MEDIATION PROGRAM § 785.5 Fees for mediation services. A requirement that non-USDA parties who elect to participate in mediation pay a fee for mediation services will...
Fritz, Matthew S; Kenny, David A; MacKinnon, David P
Mediation analysis requires a number of strong assumptions be met in order to make valid causal inferences. Failing to account for violations of these assumptions, such as not modeling measurement error or omitting a common cause of the effects in the model, can bias the parameter estimates of the mediated effect. When the independent variable is perfectly reliable, for example when participants are randomly assigned to levels of treatment, measurement error in the mediator tends to underestimate the mediated effect, while the omission of a confounding variable of the mediator-to-outcome relation tends to overestimate the mediated effect. Violations of these two assumptions often co-occur, however, in which case the mediated effect could be overestimated, underestimated, or even, in very rare circumstances, unbiased. To explore the combined effect of measurement error and omitted confounders in the same model, the effect of each violation on the single-mediator model is first examined individually. Then the combined effect of having measurement error and omitted confounders in the same model is discussed. Throughout, an empirical example is provided to illustrate the effect of violating these assumptions on the mediated effect.
Karazsia, Bryan T; Berlin, Kristoffer S; Armstrong, Bridget; Janicke, David M; Darling, Katherine E
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.
VanderWeele, Tyler J; Tchetgen Tchetgen, Eric J
In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the "mediational g-formula." When there is no mediation, the mediational g-formula reduces to Robins' regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl's mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators.
Fritz, Matthew S.; Kenny, David A.; MacKinnon, David P.
Mediation analysis requires a number of strong assumptions be met in order to make valid causal inferences. Failing to account for violations of these assumptions, such as not modeling measurement error or omitting a common cause of the effects in the model, can bias the parameter estimates of the mediated effect. When the independent variable is perfectly reliable, for example when participants are randomly assigned to levels of treatment, measurement error in the mediator tends to underestimate the mediated effect, while the omission of a confounding variable of the mediator to outcome relation tends to overestimate the mediated effect. Violations of these two assumptions often co-occur, however, in which case the mediated effect could be overestimated, underestimated, or even, in very rare circumstances, unbiased. In order to explore the combined effect of measurement error and omitted confounders in the same model, the impact of each violation on the single-mediator model is first examined individually. Then the combined effect of having measurement error and omitted confounders in the same model is discussed. Throughout, an empirical example is provided to illustrate the effect of violating these assumptions on the mediated effect. PMID:27739903
To investigate the use of VTLoE as a basis for formal derivation of functional programs with effects. As a part of the process, a number of issues central to effective formal programming are considered. In particular it is considered how to develop a proof system suitable for pratical reasoning......, how to implement this system in the generic proof assistant Isabelle and finally how to apply the logic and the implementation to programming....
O'Rourke, Holly P; MacKinnon, David P
Although previous research has studied power in mediation models, the extent to which the inclusion of a mediator will increase power has not been investigated. To address this deficit, in a first study we compared the analytical power values of the mediated effect and the total effect in a single-mediator model, to identify the situations in which the inclusion of one mediator increased statistical power. The results from this first study indicated that including a mediator increased statistical power in small samples with large coefficients and in large samples with small coefficients, and when coefficients were nonzero and equal across models. Next, we identified conditions under which power was greater for the test of the total mediated effect than for the test of the total effect in the parallel two-mediator model. These results indicated that including two mediators increased power in small samples with large coefficients and in large samples with small coefficients, the same pattern of results that had been found in the first study. Finally, we assessed the analytical power for a sequential (three-path) two-mediator model and compared the power to detect the three-path mediated effect to the power to detect both the test of the total effect and the test of the mediated effect for the single-mediator model. The results indicated that the three-path mediated effect had more power than the mediated effect from the single-mediator model and the test of the total effect. Practical implications of these results for researchers are then discussed.
Feng, Danjun; Zhao, Wenjing; Shen, Shiyu; Chen, Jieru; Li, Lu
The gender-based stereotype of nursing as a female profession has been a large obstacle to men entering the nursing profession. However, there is little quantitative research on the influence of prejudice induced by this stereotype on male nursing students' willingness to be nurses. To examine the effect of perceived prejudice on willingness to be a nurse via the mediating effect of satisfaction with major among Chinese male nursing students. A cross-sectional survey was used. Four hundred and sixty male nursing students who were enrolled either in bachelor's programs in universities or advanced diploma programs in colleges in Jinan, China, were surveyed using questionnaires measuring perceived prejudice, satisfaction with major, and willingness to be a nurse. Structural equation modeling with bias-corrected bootstrapping was employed to determine the influence of perceived prejudice on willingness to be a nurse with major satisfaction as a mediator. Male students who were in an advanced diploma nursing program and those for whom nursing was the first-choice major reported significantly less perceived prejudice, greater satisfaction with major, and greater willingness to be nurses than did those in a bachelor's nursing program and those for whom nursing was not the first-choice major, respectively. Moreover, although perceived prejudice had no significant direct effect on willingness to be a nurse (β=0.07, p>0.05), it did have a strong indirect effect (full mediation) via satisfaction with major (β=-0.59, pnursing students' willingness to be nurses via the full mediating effect of satisfaction with major. Because this obsolete stereotype of nursing as a female occupation gives birth to prejudice against male nursing students, effective measures should be taken to change this stereotype to recruit more men as nursing staff. Copyright © 2016 Elsevier Ltd. All rights reserved.
Ali Al Nima
Full Text Available 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.
Nima, Ali Al; Rosenberg, Patricia; Archer, Trevor; Garcia, Danilo
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
Liu, Hongqiang; Van Damme, Jan; Gielen, Sarah; Van Den Noortgate, Wim
School composition effects have been consistently verified, but few studies ever attempted to study how school composition affects school achievement. Based on prior research findings, we employed multilevel mediation modeling to examine whether school processes mediate the effect of school composition upon school outcomes based on the data of 28…
Full Text Available The E2F1 transcription factor regulates cell proliferation and apoptosis through the control of a considerable variety of target genes. Previous work has detailed the role of other transcription factors in mediating the specificity of E2F function. Here we identify the NF-YB transcription factor as a novel direct E2F1 target. Genome-wide expression analysis of the effects of NFYB knockdown on E2F1-mediated transcription identified a large group of genes that are co-regulated by E2F1 and NFYB. We also provide evidence that knockdown of NFYB enhances E2F1-induced apoptosis, suggesting a pro-survival function of the NFYB/E2F1 joint transcriptional program. Bioinformatic analysis suggests that deregulation of these NFY-dependent E2F1 target genes might play a role in sarcomagenesis as well as drug resistance.
Révész, D; Verhoeven, J E; Milaneschi, Y; Penninx, B W J H
Depressive and anxiety disorders are associated with shorter leukocyte telomere length (LTL), an indicator of cellular aging. It is, however, unknown which pathways underlie this association. This study examined the extent to which lifestyle factors and physiological changes such as inflammatory or metabolic alterations mediate the relationship. We applied mediation analysis techniques to data from 2750 participants of the Netherlands Study of Depression and Anxiety. LTL was assessed using quantitative polymerase chain reaction. Independent variables were current depressive (30-item Inventory of Depressive Symptoms - Self Report) and anxiety (21-item Beck's Anxiety Inventory) symptoms and presence of a depressive or anxiety disorder diagnosis based on DSM-IV; mediator variables included physiological stress systems, metabolic syndrome components and lifestyle factors. Short LTL was associated with higher symptom severity (B = -2.4, p = 0.002) and current psychiatric diagnosis (B = -63.3, p = 0.024). C-reactive protein, interleukin-6, waist circumference, triglycerides, high-density lipoprotein cholesterol and cigarette smoking were significant mediators in the relationship between psychopathology and LTL. When all significant mediators were included in one model, the effect sizes of the relationships between LTL and symptom severity and current diagnosis were reduced by 36.7 and 32.7%, respectively, and the remaining direct effects were no longer significant. Pro-inflammatory cytokines, metabolic alterations and cigarette smoking are important mediators of the association between depressive and anxiety disorders and LTL. This calls for future research on intervention programs that take into account lifestyle changes in mental health care settings.
Caprara, Gian Vittorio; Luengo Kanacri, Bernadette Paula; Zuffianò, Antonio; Gerbino, Maria; Pastorelli, Concetta
Prosocial behaviors are considered integral to intervention goals that seek to promote successful youth development. This study examines the effect of a school-based intervention program entirely designed to promote prosocial behaviors called Promoting Prosocial and Emotional Skills to Counteract Externalizing Problems in Adolescence (Italian acronym CEPIDEA). The CEPIDEA curriculum was incorporated into routine educational practices and included five major components that reflect the personal determinants of prosocial behavior during adolescence. The present study assessed 151 students (48.7% female; M(age) = 12.4) of the intervention school and 140 students (51.2% female; M(age) = 13.0) of the control school at three points. A multi-group latent curve analysis revealed that the intervention group, compared with the control group, showed an increase in prosocial behavior, interpersonal self-efficacy beliefs, and agreeableness along with a decrease in physical aggression above and beyond the normative developmental trend of the these variables. Participants of the intervention also obtained higher grades than the control group at the end of middle school. Moderation effects for prosocial behavior and agreeableness evidenced that those who benefited most from the intervention were those adolescents with lower normative development of prosocial behavior, low initial level of agreeableness, and high initial level of physical aggression. The results also showed that the increase of prosocial behaviors mediated the decline of verbal aggression in adolescents who had attended the intervention. These findings suggest that interventions aimed at promoting prosocial behaviors while having the potential to support positive outcomes may also counteract or redirect negative trajectories of functioning.
Maddison, Ralph; Mhurchu, Cliona Ni; Jull, Andrew; Prapavessis, Harry; Foley, Louise S; Jiang, Yannan
Increased understanding of why and how physical activity impacts on health outcomes is needed to increase the effectiveness of physical activity interventions. A recent randomized controlled trial of an active video game (PlayStation EyeToy™) intervention showed a statistically significant treatment effect on the primary outcome, change from baseline in body mass index (BMI), which favored the intervention group at 24 weeks. In this short paper we evaluate the mediating effects of the secondary outcomes. To identify mediators of the effect of an active video games intervention on body composition. Data from a two-arm parallel randomized controlled trial of an active video game intervention (n = 322) were analyzed. The primary outcome was change from baseline in BMI. A priori secondary outcomes were considered as potential mediators of the intervention on BMI, including aerobic fitness (VO2Max), time spent in moderate-to-vigorous physical activity (MVPA), and food snacking at 24 weeks. Only aerobic fitness at 24 weeks met the conditions for mediation, and was a significant mediator of BMI. Playing active video games can have a positive effect on body composition in overweight or obese children and this effect is most likely mediated through improved aerobic fitness. Future trials should examine other potential mediators related to this type of intervention. Australian New Zealand Clinical Trials Registry Website: http://www.anzctr.org.au. Study ID number: ACTRN12607000632493.
Vanderweele, Tyler J
The causal inference literature has provided definitions of direct and indirect effects based on counterfactuals that generalize the approach found in the social science literature. However, these definitions presuppose well-defined hypothetical interventions on the mediator. In many settings, there may be multiple ways to fix the mediator to a particular value, and these various hypothetical interventions may have very different implications for the outcome of interest. In this paper, we consider mediation analysis when multiple versions of the mediator are present. Specifically, we consider the problem of attempting to decompose a total effect of an exposure on an outcome into the portion through the intermediate and the portion through other pathways. We consider the setting in which there are multiple versions of the mediator but the investigator has access only to data on the particular measurement, not information on which version of the mediator may have brought that value about. We show that the quantity that is estimated as a natural indirect effect using only the available data does indeed have an interpretation as a particular type of mediated effect; however, the quantity estimated as a natural direct effect, in fact, captures both a true direct effect and an effect of the exposure on the outcome mediated through the effect of the version of the mediator that is not captured by the mediator measurement. The results are illustrated using 2 examples from the literature, one in which the versions of the mediator are unknown and another in which the mediator itself has been dichotomized.
Seib, Charrlotte; Porter-Steele, Janine; Ng, Shu-Kay; Turner, Jane; McGuire, Amanda; McDonald, Nicole; Balaam, Sarah; Yates, Patsy; McCarthy, Alexandra; Anderson, Debra
This paper examines the direct and intermediary relationships between life stress, stress appraisal, and resilience, and increased anxiety and depressive symptoms in Australian women after cancer treatment. Data examined from 278 women aged 18 years and older previously treated for breast, gynaecological, or blood cancer, participating in the Australian Women's Wellness after Cancer Program. Serial mediation models interrogated the effect of stressful life events (List of Threatening Experiences-Modified) mediated by appraisal and coping (Perceived Stress Scale and Connor-Davidson Resilience Scale), on symptoms of anxiety and depression (Zung Self-rating Anxiety Scale and Center for Epidemiologic Studies Depression Scale). Over one-quarter (30.2%) of participants reported 1 or more stressful life events, other than their cancer, in the previous 6 months. Results indicate that perceived stress fully mediated the relationships between life stress, anxiety (indirect effect = 0.09, Bias-corrected bootstrap 95% CI 0.02-0.18, Percent mediation = 0.51), and depressive symptoms (indirect effect = 0.11, Bias-corrected bootstrap 95% CI 0.02-0.23, Percent mediation = 0.71) and accounted for more than half of the relationship between predictor and outcome. Findings indicate that stress appraisal mediated the relationship between past life stressors and anxiety and depressive symptoms. This analysis also highlights the need to consider wellness within a broader care context to identify potentially vulnerable patients to possibly avert future health concerns. Copyright © 2018 John Wiley & Sons, Ltd.
Mediatization research shares media effects studies' ambition of answering the difficult questions with regard to whether and how media matter and influence contemporary culture and society. The two approaches nevertheless differ fundamentally in that mediatization research seeks answers...... to these general questions by distinguishing between two concepts: mediation and mediatization. The media effects tradition generally considers the effects of the media to be a result of individuals being exposed to media content, i.e. effects are seen as an outcome of mediated communication. Mediatization...... research is concerned with long-term structural changes involving media, culture, and society, i.e. the influences of the media are understood in relation to how media are implicated in social and cultural changes and how these processes come to create new conditions for human communication and interaction...
Berkel, Cady; Mauricio, Anne M; Sandler, Irwin N; Wolchik, Sharlene A; Gallo, Carlos G; Brown, C Hendricks
This study tests a theoretical cascade model in which multiple dimensions of facilitator delivery predict indicators of participant responsiveness, which in turn lead to improvements in targeted program outcomes. An effectiveness trial of the 10-session New Beginnings Program for divorcing families was implemented in partnership with four county-level family courts. This study included 366 families assigned to the intervention condition who attended at least one session. Independent observers provided ratings of program delivery (i.e., fidelity to the curriculum and process quality). Facilitators reported on parent attendance and parents' competence in home practice of program skills. At pretest and posttest, children reported on parenting and parents reported child mental health. We hypothesized effects of quality on attendance, fidelity and attendance on home practice, and home practice on improvements in parenting and child mental health. Structural Equation Modeling with mediation and moderation analyses were used to test these associations. Results indicated quality was significantly associated with attendance, and attendance moderated the effect of fidelity on home practice. Home practice was a significant mediator of the links between fidelity and improvements in parent-child relationship quality and child externalizing and internalizing problems. Findings provide support for fidelity to the curriculum, process quality, attendance, and home practice as valid predictors of program outcomes for mothers and fathers. Future directions for assessing implementation in community settings are discussed.
Min Hyun Suk, PhD, RN
Conclusions: Given the meaningful influence of positive multicultural attitude on cultural sensitivity and significant mediator effect of self efficacy as a school nurse between the two variables, the strategies to cultivate a positive multicultural attitude and enhance school nurses' self efficacy in their unique role should be considered in a training program. School nurses' health care services will benefit from the improvement of cultural sensitivity toward young children from multicultural families.
... 7 Agriculture 7 2010-01-01 2010-01-01 false Mediation. 780.9 Section 780.9 Agriculture Regulations... PROGRAMS APPEAL REGULATIONS § 780.9 Mediation. (a) Any request for mediation must be submitted after... once: (1) If resolution of an adverse decision is not achieved in mediation, a participant may exercise...
Full Text Available Abstract Background Increased understanding of why and how physical activity impacts on health outcomes is needed to increase the effectiveness of physical activity interventions. A recent randomized controlled trial of an active video game (PlayStation EyeToy™ intervention showed a statistically significant treatment effect on the primary outcome, change from baseline in body mass index (BMI, which favored the intervention group at 24 weeks. In this short paper we evaluate the mediating effects of the secondary outcomes. Objective To identify mediators of the effect of an active video games intervention on body composition. Methods Data from a two-arm parallel randomized controlled trial of an active video game intervention (n = 322 were analyzed. The primary outcome was change from baseline in BMI. A priori secondary outcomes were considered as potential mediators of the intervention on BMI, including aerobic fitness (VO2Max, time spent in moderate-to-vigorous physical activity (MVPA, and food snacking at 24 weeks. Results Only aerobic fitness at 24 weeks met the conditions for mediation, and was a significant mediator of BMI. Conclusion Playing active video games can have a positive effect on body composition in overweight or obese children and this effect is most likely mediated through improved aerobic fitness. Future trials should examine other potential mediators related to this type of intervention. Trial registration Australian New Zealand Clinical Trials Registry Website: http://www.anzctr.org.au Study ID number: ACTRN12607000632493
Purpose: The aim of this research was to investigate the effect of transformational leadership and transactional contingent reward as complementary, but distinct, forms of leadership on facets of organizational identification via the perception of innovation and goal organizational values. Design/Methodology/Approach: Three studies were carried out implementing either a measurement of mediation or experimental-causal-chain design to test for the hypothesized effects. Findings: The measurement of mediation study showed that transformational leadership had a positive direct and indirect effect, via innovation value orientation, on cognitive identification, whereas transactional contingent reward was more strongly related to affective, rather than cognitive, identification, and goal orientation was a mediator of their link. The findings of the two experimental-causal-chain studies further supported the hypothesized effects. Transformational leadership was found to lead subordinates to perceive the culture as more innovative compared to transactional contingent reward, whereas transactional contingent reward led employees to perceive the culture as more goal, than innovation, oriented. Finally, innovation, compared to goal, value orientation increased cognitive identification, while goal orientation facilitated affective, rather than cognitive, identification. Implications: The practical implications involve the development of strategies organizations can apply, such as leadership training programs, to strengthen their ties with their employees, which, in turn, may have a positive impact on in-role, as well as extra-role, behaviors. Originality/Value: The originality of this research concerns the identification of distinct mechanisms explaining the effect of transformational leadership and transactional contingent reward on cognitive and affective identification applying an organizational culture perspective and a combination of measurement and causal mediation designs.
Yang, Fan; Wang, Jiebiao; Pierce, Brandon L; Chen, Lin S
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.
Benzo, Roberto P; Abascal-Bolado, Beatriz; Dulohery, Megan M
This study aimed to increase our understanding of general self-management (SM) abilities in COPD by determining if SM can predict disease specific quality of life (QoL), by investigating whether specific SM domains are significant in COPD and by exploring the mediating effect of the positive/negative affect in the association between SM and QoL. Cross-sectional study based on 292 patients with COPD. Measures included demographics, lung function, gait speed, health care utilization, positive/negative affect, SM abilities, breathlessness and disease specific QoL. We performed, correlation, multiple regression models and mediation analysis (positive/negative affect being mediator between SM and QoL association). After controlling for breathlessness, living alone, marital status, hospitalization history, age and lung function, SM related to QoL (pnegative affect ratio completely mediates the relationship of SM with QoL. SM is independently associated with disease specific QoL in COPD after adjustment significant covariates but positive/negative affect ratio completely mediates the relationship of SM with QoL. Measuring positive/negative affect and addressing investment behavior and self-efficacy are important in implementing COPD-SM programs. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.
Wang, Jian; Spitz, Margaret R; Amos, Christopher I; Wu, Xifeng; Wetter, David W; Cinciripini, Paul M; Shete, Sanjay
A mediation model explores the direct and indirect effects between an independent variable and a dependent variable by including other variables (or mediators). Mediation analysis has recently been used to dissect the direct and indirect effects of genetic variants on complex diseases using case-control studies. However, bias could arise in the estimations of the genetic variant-mediator association because the presence or absence of the mediator in the study samples is not sampled following the principles of case-control study design. In this case, the mediation analysis using data from case-control studies might lead to biased estimates of coefficients and indirect effects. In this article, we investigated a multiple-mediation model involving a three-path mediating effect through two mediators using case-control study data. We propose an approach to correct bias in coefficients and provide accurate estimates of the specific indirect effects. Our approach can also be used when the original case-control study is frequency matched on one of the mediators. We employed bootstrapping to assess the significance of indirect effects. We conducted simulation studies to investigate the performance of the proposed approach, and showed that it provides more accurate estimates of the indirect effects as well as the percent mediated than standard regressions. We then applied this approach to study the mediating effects of both smoking and chronic obstructive pulmonary disease (COPD) on the association between the CHRNA5-A3 gene locus and lung cancer risk using data from a lung cancer case-control study. The results showed that the genetic variant influences lung cancer risk indirectly through all three different pathways. The percent of genetic association mediated was 18.3% through smoking alone, 30.2% through COPD alone, and 20.6% through the path including both smoking and COPD, and the total genetic variant-lung cancer association explained by the two mediators was 69.1%.
Full Text Available A mediation model explores the direct and indirect effects between an independent variable and a dependent variable by including other variables (or mediators. Mediation analysis has recently been used to dissect the direct and indirect effects of genetic variants on complex diseases using case-control studies. However, bias could arise in the estimations of the genetic variant-mediator association because the presence or absence of the mediator in the study samples is not sampled following the principles of case-control study design. In this case, the mediation analysis using data from case-control studies might lead to biased estimates of coefficients and indirect effects. In this article, we investigated a multiple-mediation model involving a three-path mediating effect through two mediators using case-control study data. We propose an approach to correct bias in coefficients and provide accurate estimates of the specific indirect effects. Our approach can also be used when the original case-control study is frequency matched on one of the mediators. We employed bootstrapping to assess the significance of indirect effects. We conducted simulation studies to investigate the performance of the proposed approach, and showed that it provides more accurate estimates of the indirect effects as well as the percent mediated than standard regressions. We then applied this approach to study the mediating effects of both smoking and chronic obstructive pulmonary disease (COPD on the association between the CHRNA5-A3 gene locus and lung cancer risk using data from a lung cancer case-control study. The results showed that the genetic variant influences lung cancer risk indirectly through all three different pathways. The percent of genetic association mediated was 18.3% through smoking alone, 30.2% through COPD alone, and 20.6% through the path including both smoking and COPD, and the total genetic variant-lung cancer association explained by the two
Blanco, Fernando; Matute, Helena; A Vadillo, Miguel
Several classic studies have concluded that the accuracy of identifying uncontrollable situations depends heavily on depressive mood. Nondepressed participants tend to exhibit an optimistic illusion of control, whereas depressed participants tend to better detect a lack of control. Recently, we suggested that the different activity levels (measured as the probability of responding during a contingency learning task) exhibited by depressed and nondepressed individuals is partly responsible for this effect. The two studies presented in this paper provide further support for this mediational hypothesis, in which mood is the distal cause of the illusion of control operating through activity level, the proximal cause. In Study 1, the probability of responding, P(R), was found to be a mediator variable between the depressive symptoms and the judgments of control. In Study 2, we intervened directly on the mediator variable: The P(R) for both depressed and nondepressed participants was manipulated through instructions. Our results confirm that P(R) manipulation produced differences in the participants' perceptions of uncontrollability. Importantly, the intervention on the mediator variable cancelled the effect of the distal cause; the participants' judgments of control were no longer mood dependent when the P(R) was manipulated. This result supports the hypothesis that the so-called depressive realism effect is actually mediated by the probability of responding.
Huang, Yen-Tsung; Yang, Hwai-I
Mediation analyses have been a popular approach to investigate the effect of an exposure on an outcome through a mediator. Mediation models with multiple mediators have been proposed for continuous and dichotomous outcomes. However, development of multimediator models for survival outcomes is still limited. We present methods for multimediator analyses using three survival models: Aalen additive hazard models, Cox proportional hazard models, and semiparametric probit models. Effects through mediators can be characterized by path-specific effects, for which definitions and identifiability assumptions are provided. We derive closed-form expressions for path-specific effects for the three models, which are intuitively interpreted using a causal diagram. Mediation analyses using Cox models under the rare-outcome assumption and Aalen additive hazard models consider effects on log hazard ratio and hazard difference, respectively; analyses using semiparametric probit models consider effects on difference in transformed survival time and survival probability. The three models were applied to a hepatitis study where we investigated effects of hepatitis C on liver cancer incidence mediated through baseline and/or follow-up hepatitis B viral load. The three methods show consistent results on respective effect scales, which suggest an adverse estimated effect of hepatitis C on liver cancer not mediated through hepatitis B, and a protective estimated effect mediated through the baseline (and possibly follow-up) of hepatitis B viral load. Causal mediation analyses of survival outcome with multiple mediators are developed for additive hazard and proportional hazard and probit models with utility demonstrated in a hepatitis study.
Choi, Eun Ha; Kim, Eun-Kyung; Kim, Pil Bong
EDUCATIONAL LEADERSHIP OF NURSING UNIT MANAGERS ON TEAM EFFECTIVENESS: Mediating Effects of Organizational Communication Satisfaction. This study identifies the effects of the educational leadership of nursing unit managers on team effectiveness and the mediating effects of organizational communication satisfaction; it highlights the importance of educational leadership and organizational communication and provides the data needed to enhance the education capacity of managers. The participants were 216 nursing unit managers of staff nurses at a tertiary hospital located in C Region, South Korea, and nurses who had worked for more than six months at the same hospital. This study was conducted using questionnaires on educational leadership, team effectiveness, and organizational communication satisfaction. Data analysis was performed with a t-test, ANOVA, Scheffé, Pearson's correlation coefficient, and simple and multiple regression analyses using SPSS version 23.0. Mediation analysis was tested using Baron and Kenny's regression analysis and a Sobel test. The mean score for the educational leadership of nursing unit managers was 3.74(±0.68); for organizational communication satisfaction, 3.14(±0.51); and for team effectiveness, 3.52(±0.49). Educational leadership was significantly positively correlated with team effectiveness and organizational communication satisfaction. Organizational communication satisfaction demonstrated a complete mediating effect on the relationship between educational leadership and team effectiveness (β=.61, pcommunication satisfaction among nurses; this supports the idea that educational leadership can contribute to team effectiveness. This suggests that the educational leadership and communication capacity of nursing unit managers must be improved to enhance the performance of nursing organizations. Copyright © 2018. Published by Elsevier B.V.
Full Text Available Mediation refers to the effect transmitted by mediators that intervene in the relationship between an exposure and a response variable. Mediation analysis has been broadly studied in many fields. However, it remains a challenge for researchers to consider complicated associations among variables and to differentiate individual effects from multiple mediators.  proposed general definitions of mediation effects that were adaptable to all different types of response (categorical or continuous, exposure, or mediation variables. With these definitions, multiple mediators of different types can be considered simultaneously, and the indirect effects carried by individual mediators can be separated from the total effect. Moreover, the derived mediation analysis can be performed with general predictive models. That is, the relationships among variables can be modeled using not only generalized linear models but also nonparametric models such as the Multiple Additive Regression Trees. Therefore, more complicated variable transformations and interactions can be considered in analyzing the mediation effects. The proposed method is realized by the R package 'mma'. We illustrate in this paper the proposed method and how to use 'mma' to estimate mediation effects and make inferences.
Tsai, Wen-Wei; Matsumura, Shigenobu; Liu, Weiyi; Phillips, Naomi G; Sonntag, Tim; Hao, Ergeng; Lee, Soon; Hai, Tsonwin; Montminy, Marc
Increases in circulating glucagon during fasting maintain glucose balance by stimulating hepatic gluconeogenesis. Acute ethanol intoxication promotes fasting hypoglycemia through an increase in hepatic NADH, which inhibits hepatic gluconeogenesis by reducing the conversion of lactate to pyruvate. Here we show that acute ethanol exposure also lowers fasting blood glucose concentrations by inhibiting the CREB-mediated activation of the gluconeogenic program in response to glucagon. Ethanol exposure blocked the recruitment of CREB and its coactivator CRTC2 to gluconeogenic promoters by up-regulating ATF3, a transcriptional repressor that also binds to cAMP-responsive elements and thereby down-regulates gluconeogenic genes. Targeted disruption of ATF3 decreased the effects of ethanol in fasted mice and in cultured hepatocytes. These results illustrate how the induction of transcription factors with overlapping specificity can lead to cross-coupling between stress and hormone-sensitive pathways.
Katzmann, Josepha; Hautmann, Christopher; Greimel, Lisa; Imort, Stephanie; Pinior, Julia; Scholz, Kristin; Döpfner, Manfred
Parent training (PT) delivered as a guided self-help intervention may be a cost- and time-effective intervention in the treatment of children with externalizing disorders. In face-to-face PT, parenting strategies have repeatedly been identified as mediating mechanisms for the decrease of children's problem behavior. Few studies have examined possible mediating effects in guided self-help interventions for parents. The present study aimed to investigate possible mediating variables of a behaviorally oriented guided self-help program for parents of children with externalizing problems compared to a nondirective intervention in a clinical sample. A sample of 110 parents of children with externalizing disorders (80 % boys) were randomized to either a behaviorally oriented or a nondirective guided self-help program. Four putative mediating variables were examined simultaneously in a multiple mediation model using structural equation modelling. The outcomes were child symptoms of ADHD and ODD as well as child externalizing problems, assessed at posttreatment. Analyses showed a significant indirect effect for dysfunctional parental attributions in favor of the group receiving the behavioral program, and significant effects of the behavioral program on positive and negative parenting and parental self-efficacy, compared to the nondirective intervention. Our results indicate that a decrease of dysfunctional parental attributions leads to a decrease of child externalizing problems when parents take part in a behaviorally oriented guided self-help program. However, none of the putative mediating variables could explain the decrease in child externalizing behavior problems in the nondirective group. A change in dysfunctional parental attributions should be considered as a possible mediator in the context of PT.
Full Text Available Abstract Background Regular participation in physical activity can prevent many chronic health conditions. Computerized self-management programs are effective clinical tools to support patient participation in physical activity. This pilot study sought to develop and evaluate an online interface for primary care providers to refer patients to an Internet-mediated walking program called Stepping Up to Health (SUH and to monitor participant progress in the program. Methods In Phase I of the study, we recruited six pairs of physicians and medical assistants from two family practice clinics to assist with the design of a clinical interface. During Phase II, providers used the developed interface to refer patients to a six-week pilot intervention. Provider perspectives were assessed regarding the feasibility of integrating the program into routine care. Assessment tools included quantitative and qualitative data gathered from semi-structured interviews, surveys, and online usage logs. Results In Phase I, 13 providers used SUH and participated in two interviews. Providers emphasized the need for alerts flagging patients who were not doing well and the ability to review participant progress. Additionally, providers asked for summary views of data across all enrolled clinic patients as well as advertising materials for intervention recruitment. In response to this input, an interface was developed containing three pages: 1 a recruitment page, 2 a summary page, and 3 a detailed patient page. In Phase II, providers used the interface to refer 139 patients to SUH and 37 (27% enrolled in the intervention. Providers rarely used the interface to monitor enrolled patients. Barriers to regular use of the intervention included lack of integration with the medical record system, competing priorities, patient disinterest, and physician unease with exercise referrals. Intention-to-treat analyses showed that patients increased walking by an average of 1493 steps
Gilsoul, Jessica; Simon, Jessica; Hogge, Michaël; Collette, Fabienne
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.
Full Text Available Several classic studies have concluded that the accuracy of identifying uncontrollable situations depends heavily on depressive mood. Nondepressed participants tend to exhibit an optimistic illusion of control, whereas depressed participants tend to better detect a lack of control. Recently, we suggested that the different activity levels (measured as the probability of responding during a contingency learning task exhibited by depressed and nondepressed individuals is partly responsible for this effect. The two studies presented in this paper provide further support for this mediational hypothesis, in which mood is the distal cause of the illusion of control operating through activity level, the proximal cause. In Study 1, the probability of responding, P(R, was found to be a mediator variable between the depressive symptoms and the judgments of control. In Study 2, we intervened directly on the mediator variable: The P(R for both depressed and nondepressed participants was manipulated through instructions. Our results confirm that P(R manipulation produced differences in the participants' perceptions of uncontrollability. Importantly, the intervention on the mediator variable cancelled the effect of the distal cause; the participants' judgments of control were no longer mood dependent when the P(R was manipulated. This result supports the hypothesis that the so-called depressive realism effect is actually mediated by the probability of responding.
Blanco, Fernando; Matute, Helena; A. Vadillo, Miguel
Several classic studies have concluded that the accuracy of identifying uncontrollable situations depends heavily on depressive mood. Nondepressed participants tend to exhibit an optimistic illusion of control, whereas depressed participants tend to better detect a lack of control. Recently, we suggested that the different activity levels (measured as the probability of responding during a contingency learning task) exhibited by depressed and nondepressed individuals is partly responsible for this effect. The two studies presented in this paper provide further support for this mediational hypothesis, in which mood is the distal cause of the illusion of control operating through activity level, the proximal cause. In Study 1, the probability of responding, P(R), was found to be a mediator variable between the depressive symptoms and the judgments of control. In Study 2, we intervened directly on the mediator variable: The P(R) for both depressed and nondepressed participants was manipulated through instructions. Our results confirm that P(R) manipulation produced differences in the participants’ perceptions of uncontrollability. Importantly, the intervention on the mediator variable cancelled the effect of the distal cause; the participants’ judgments of control were no longer mood dependent when the P(R) was manipulated. This result supports the hypothesis that the so-called depressive realism effect is actually mediated by the probability of responding. PMID:23029435
VanderWeele, Tyler J.; Vansteelandt, Stijn; Robins, James M.
Methods from causal mediation analysis have generalized the traditional approach to direct and indirect effects in the epidemiologic and social science literature by allowing for interaction and non-linearities. However, the methods from the causal inference literature have themselves been subject to a major limitation in that the so-called natural direct and indirect effects that are employed are not identified from data whenever there is a variable that is affected by the exposure, which also confounds the relationship between the mediator and the outcome. In this paper we describe three alternative approaches to effect decomposition that give quantities that can be interpreted as direct and indirect effects, and that can be identified from data even in the presence of an exposure-induced mediator-outcome confounder. We describe a simple weighting-based estimation method for each of these three approaches, illustrated with data from perinatal epidemiology. The methods described here can shed insight into pathways and questions of mediation even when an exposure-induced mediator-outcome confounder is present. PMID:24487213
Barata José T
Full Text Available Abstract Background Changes in body image and subjective well-being variables (e.g. self-esteem are often reported as outcomes of obesity treatment. However, they may, in turn, also influence behavioral adherence and success in weight loss. The present study examined associations among obesity treatment-related variables, i.e., change in weight, quality of life, body image, and subjective well-being, exploring their role as both mediators and outcomes, during a behavioral obesity treatment. Methods Participants (BMI = 31.1 ± 4.1 kg/m2; age = 38.4 ± 6.7 y were 144 women who attended a 12-month obesity treatment program and a comparison group (n = 49, who received a general health education program. The intervention included regular group meetings promoting lasting behavior changes in physical activity and dietary intake. Body image, quality of life, subjective well-being, and body weight were measured at baseline and treatment's end. Mediation was tested by multiple regression and a resampling approach to measure indirect effects. Treatment group assignment was the independent variable while changes in weight and in psychosocial variables were analyzed alternatively as mediators and as dependent variables. Results At 12 months, the intervention group had greater weight loss (-5.6 ± 6.8% vs. -1.2 ± 4.6%, p Conclusion Changes in weight and body image may reciprocally affect each other during the course of behavioral obesity treatment. No evidence of reciprocal relationships was found for the other models under analysis; however, weight changes partially explained the effects of treatment on quality of life and self-esteem. Weight and psychosocial changes co-occur during treatment and will probably influence each other dynamically, in ways not yet adequately understood. Results from this study support the inclusion of intervention contents aimed at improving body image in weight management programs.
Purpose: The aim of this research was to investigate the effect of transformational leadership and transactional contingent reward as complementary, but distinct, forms of leadership on facets of organizational identification via the perception of innovation and goal organizational values. Design/Methodology/Approach: Three studies were carried out implementing either a measurement of mediation or experimental-causal-chain design to test for the hypothesized effects. Findings: The measurement of mediation study showed that transformational leadership had a positive direct and indirect effect, via innovation value orientation, on cognitive identification, whereas transactional contingent reward was more strongly related to affective, rather than cognitive, identification, and goal orientation was a mediator of their link. The findings of the two experimental-causal-chain studies further supported the hypothesized effects. Transformational leadership was found to lead subordinates to perceive the culture as more innovative compared to transactional contingent reward, whereas transactional contingent reward led employees to perceive the culture as more goal, than innovation, oriented. Finally, innovation, compared to goal, value orientation increased cognitive identification, while goal orientation facilitated affective, rather than cognitive, identification. Implications: The practical implications involve the development of strategies organizations can apply, such as leadership training programs, to strengthen their ties with their employees, which, in turn, may have a positive impact on in-role, as well as extra-role, behaviors. Originality/Value: The originality of this research concerns the identification of distinct mechanisms explaining the effect of transformational leadership and transactional contingent reward on cognitive and affective identification applying an organizational culture perspective and a combination of measurement and causal mediation designs
... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false OCRM mediation. 930.111 Section 930... FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Secretarial Mediation § 930.111 OCRM mediation. The availability of mediation does not preclude use by the parties of alternative means for...
Daniel, R M; De Stavola, B L; Cousens, S N; Vansteelandt, S
In diverse fields of empirical research-including many in the biological sciences-attempts are made to decompose the effect of an exposure on an outcome into its effects via a number of different pathways. For example, we may wish to separate the effect of heavy alcohol consumption on systolic blood pressure (SBP) into effects via body mass index (BMI), via gamma-glutamyl transpeptidase (GGT), and via other pathways. Much progress has been made, mainly due to contributions from the field of causal inference, in understanding the precise nature of statistical estimands that capture such intuitive effects, the assumptions under which they can be identified, and statistical methods for doing so. These contributions have focused almost entirely on settings with a single mediator, or a set of mediators considered en bloc; in many applications, however, researchers attempt a much more ambitious decomposition into numerous path-specific effects through many mediators. In this article, we give counterfactual definitions of such path-specific estimands in settings with multiple mediators, when earlier mediators may affect later ones, showing that there are many ways in which decomposition can be done. We discuss the strong assumptions under which the effects are identified, suggesting a sensitivity analysis approach when a particular subset of the assumptions cannot be justified. These ideas are illustrated using data on alcohol consumption, SBP, BMI, and GGT from the Izhevsk Family Study. We aim to bridge the gap from "single mediator theory" to "multiple mediator practice," highlighting the ambitious nature of this endeavor and giving practical suggestions on how to proceed. © 2014 The Authors Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.
Bergman, Ingvar; Almkvist, Ove
The present study investigated the extent to which the effect of age on cognitive ability is predicted by individual differences in physical health. The sample consisted of 118 volunteer subjects who were healthy and ranging in age from 26 to 91. The examinations included a clinical investigation, magnetic resonance imaging (MRI) brain neuroimaging, and a comprehensive neuropsychological assessment. The effect of age on fluid IQ with and without visual spatial praxis and on crystallized IQ was tested whether being fully-, partially- or non-mediated by physical health. Structural equation analyses showed that the best and most parsimonious fit to the data was provided by models that were fully mediated for fluid IQ without praxis, non-mediated for crystallized IQ and partially mediated for fluid IQ with praxis. The diseases of the circulatory and nervous systems were the major mediators. It was concluded from the pattern of findings that the effect of age on fluid intelligence is fully mediated by physical health, while crystallized intelligence is non-mediated and visual spatial praxis is partially mediated, influenced mainly by direct effects of age. Our findings imply that improving health by acting against the common age-related circulatory- and nervous system diseases and risk factors will oppose the decline in fluid intelligence with age. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
... 45 Public Welfare 3 2010-10-01 2010-10-01 false Mediation. 617.10 Section 617.10 Public Welfare... OF AGE IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE FROM NSF § 617.10 Mediation. (a) NSF will refer to the Federal Mediation and Conciliation Service all complaints that fall within...
Sigal, Amanda B.; Wolchik, Sharlene A.; Tein, Jenn-Yun; Sandler, Irwin N.
This study examined whether the New Beginnings Program for divorced families led to improvements in youth's educational goals and job aspirations 6 years following participation and tested whether several parenting and youth variables mediated the program effects. Participants were 240 youth aged 9 to 12 years at the initial assessment, and data…
Anomaly-mediated supersymmetry breaking in the context of 4D conformally sequestered models is combined with Poppitz-Trivedi D-type gauge-mediation. The implementation of the two mediation mechanisms naturally leads to visible soft masses at the same scale so that they can cooperatively solve the μ and flavor problems of weak scale supersymmetry, as well as the tachyonic-slepton problem of pure anomaly-mediation. The tools are developed in a modular fashion for more readily fitting into the general program of optimizing supersymmetric dynamics in hunting for the most attractive weak scale phenomenologies combined with Planck-scale plausibility
Hsu, Mei-Chi; Tu, Chun-Hsien
To test a hypothetical three-path mediation model evaluating the effects of functional status and depressive symptoms on the relationship between fatigue and quality of life in patients with cancer on the basis of the Theory of Unpleasant Symptoms. Patients with cancer often experience two or more concurrent, interrelated, mutually influential symptoms. Multiple unpleasant symptoms that have been proposed as mediating variables affecting quality of life in a model proposed in recent cancer studies are scanty. This study was a cross-sectional, descriptive, correlational design. Three hundred and twenty-six patients with cancer from oncology clinics were recruited in Taiwan between 2010-2011. Mediation models were tested and confirmed by applying structural modelling using Analysis of Moment Structures and the joint significance test. Fatigue affects patient quality of life directly or indirectly through functional status and depressive symptoms. These two mediating variables exhibited direct effects on quality of life. A path analysis approach revealed that 47·28 and 67·70% of the total effects of functional status and depressive symptoms, respectively, on the quality-of-life mediation models are attributable to 29·6 and 44·7% of the total effects between fatigue and quality of life, which mediated through two mediators, respectively. Quality of life may be enhanced by simultaneously improving physiological and psychological factors. An understanding of mediating effects is valuable in nursing care of patients with cancer, particularly in the early phase of treatment or in newly diagnosed stages I-III or recently treated patients with cancer in different disease stages. © 2013 John Wiley & Sons Ltd.
Yu, Yongju; Peng, Li; Liu, Botao; Liu, Yunbo; Li, Min; Chen, Long; Xie, Junrun; Li, Jing; Li, Jiawen
Stress-related growth can occur after various traumas or stressful events. In order to investigate how anxiety and depression relate to stress-related growth, this study was conducted with 443 Chinese army recruits who had just finished a 3-month recruit training program. Path analyses revealed that resilience and positive/negative coping partially mediated the effect of anxiety on perceived stress-related growth, while negative coping fully mediated the relationship between depression and perceived stress-related growth. Moreover, positive coping partially carried the influence of resilience on perceived stress-related growth. Anxiety and depression may be potential targets for intervention to enhance the development of stress-related growth among Chinese army recruits. © The Author(s) 2015.
Qingzhao Yu; Bin Li
Mediation refers to the effect transmitted by mediators that intervene in the relationship between an exposure and a response variable. Mediation analysis has been broadly studied in many fields. However, it remains a challenge for researchers to consider complicated associations among variables and to differentiate individual effects from multiple mediators.  proposed general definitions of mediation effects that were adaptable to all different types of response (categorical or continuous...
Visser, S.; Danielson, R.M.; Parr, J.F.
The interactions of soil physical, chemical, and biological processes are ultimately expressed in a soil's fertility and its capacity for plant production. Consequently, much of the research conducted to date regarding the impact of acid-forming pollutants on soil properties has been geared towards possible effects on plant productivity. This trend continues in this paper where the effects of acidic deposition on microbial communities are reviewed in relation to potential impact on plant growth. The objectives of the review are to discuss: (1) The effects of acid-forming emissions (primarily S-containing pollutants) on microbial community structure with emphasis on qualitative and quantitative aspects; (2) The effects of acidic deposition on microbially mediated processes (i.e., community functions); (3) Acidification effects of pollutants on symbiotic and disease-causing microorganisms. The symbionts discussed include ectomycorrhizal fungi, vesicular-arbuscular mycorrhizal fungi, and N/sub 2/-fixing bacteria, particularly Rhizobium, while the disease-causing microorganisms will include those responsible for foliage, stem, and root diseases.
Stacey, F G; James, E L; Chapman, K; Lubans, D R
Despite increasing numbers of cancer survivors and evidence that diet and physical activity improves the health of cancer survivors, most do not meet guidelines. Some social cognitive theory (SCT)-based interventions have increased physical activity behavior, however few have used objective physical activity measures. The Exercise and Nutrition Routine Improving Cancer Health (ENRICH) randomized controlled trial reported a significant intervention effect for the primary outcome of pedometer-assessed step counts at post-test (8-weeks) and follow-up (20-weeks). The aim of this study was to test whether the SCT constructs operationalized in the ENRICH intervention were mediators of physical activity behavior change. Randomized controlled trial with 174 cancer survivors and carers assessed at baseline, post-test (8-weeks), and follow-up (20-weeks). Participants were randomized to the ENRICH six session face-to-face healthy lifestyle program, or to a wait-list control. Hypothesized SCT mediators of physical activity behavior change (self-efficacy, behavioral goal, outcome expectations, impediments, and social expectations) were assessed using valid and reliable scales. Mediation was assessed using the Preacher and Hayes SPSS INDIRECT macro. At eight weeks, there was a significant intervention effect on behavioral goal (A = 9.12, p = 0.031) and outcome expectations (A = 0.25, p = 0.042). At 20 weeks, the intervention had a significant effect on self-efficacy (A = 0.31, p = 0.049) and behavioral goal (A = 13.15, p = 0.011). Only changes in social support were significantly associated with changes in step counts at eight weeks (B = 633.81, p = 0.023). Behavioral goal was the only SCT construct that had a significant mediating effect on step counts, and explained 22 % of the intervention effect at 20 weeks (AB = 397.9, 95 % CI 81.5-1025.5). SCT constructs had limited impact on objectively-assessed step counts in a multiple health
Wang, Yan; Chen, Xinguang; Gong, Jie; Yan, Yaqiong
More effective tobacco prevention and cessation programs require in-depth understanding of the mechanism by which multiple factors interact with each other to affect smoking behaviors. Stress has long been recognized as a risk factor for smoking. However, the underlying mediation and moderation mechanisms are far from clear. The purpose of this study was to examine the role of negative emotions in mediating the link between stress and smoking and whether this indirect link was modified by resilience. Survey data were collected using audio computer-assisted self-interview (ACASI) from a large random sample of urban residents (n = 1249, mean age = 35.1, 45.3% male) in Wuhan, China. Perceived stress, negative emotions (anxiety, depression), resilience were measured with reliable instruments also validated in China. Self-reported smoking was validated with exhaled carbon monoxide. Mediation analysis indicated that two negative emotions fully mediated the link between stress and intensity of smoking (assessed by number of cigarettes smoked per day, effect =.082 for anxiety and.083 for depression) and nicotine dependence (assessed by DSM-IV standard, effect =.134 for anxiety and.207 for depression). Moderated mediation analysis demonstrated that the mediation effects of negative emotions were negatively associated with resilience. Results suggest resilience interacts with stress and negative emotions to affect the risk of tobacco use and nicotine dependence among Chinese adults. Further research with longitudinal data is needed to verify the findings of this study and to estimate the effect size of resilience in tobacco intervention and cessation programs.
Lecheler, S.K.; de Vreese, C.H.
There is no satisfactory account of the psychological processes that mediate a news framing effect. Based on an experimental study (N = 1,537), this article presents a mediation analysis of a news framing effect on opinion, testing for two important mediation processes: belief importance and belief
Full Text Available The increasing dependency of emerging adults (EA on their family of origin and their lower future expectations challenge intergenerational family support exchanges and may affect their impact on satisfaction with life. This study aims to examine the mediation effect of familism, filial maturity, and relationship satisfaction between different directions of support (received, given and anticipated between both and satisfaction with life. Data was collected through the administration of self-report questionnaires to a convenience sample of 243 EA (18-30 years old of both genders, students and workers, of different socioeconomic statuses. Results corroborate the mediation effect of the study variables and suggest that the magnitude of this impact depends on the direction of the support: partial mediations are observed for the received support, whereas total mediations are observed for the given support.
Koehn, S; Stavrou, N A M; Young, J A; Morris, T
The applied model of mental imagery use proposed an interaction effect between imagery type and imagery ability. This study had two aims: (a) the examination of imagery ability as a moderating variable between imagery type and dispositional flow, and (b) the testing of alternative mediation models. The sample consisted of 367 athletes from Scotland and Australia, who completed the Sport Imagery Questionnaire, Sport Imagery Ability Questionnaire, and Dispositional Flow Scale-2. Hierarchical regression analysis showed direct effects of imagery use and imagery ability on flow, but no significant interaction. Mediation analysis revealed a significant indirect path, indicating a partially mediated relationship (P = 0.002) between imagery use, imagery ability, and flow. Partial mediation was confirmed when the effect of cognitive imagery use and cognitive imagery ability was tested, and a full mediation model was found between motivational imagery use, motivational imagery ability, and flow. The results are discussed in conjunction with potential future research directions on advancing theory and applications. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Chung, Jiwoo [College of Pharmacy, CMRI, Research Institute of Pharmaceutical Sciences, BK21 Plus KNU Multi-Omics Based Creative Drug Research Team, Kyungpook National University, Daegu 41566 (Korea, Republic of); Ku, Sae-Kwang [Department of Anatomy and Histology, College of Korean Medicine, Daegu Haany University, Gyeongsan 38610 (Korea, Republic of); Lee, Suyeon [College of Pharmacy, CMRI, Research Institute of Pharmaceutical Sciences, BK21 Plus KNU Multi-Omics Based Creative Drug Research Team, Kyungpook National University, Daegu 41566 (Korea, Republic of); Bae, Jong-Sup, E-mail: firstname.lastname@example.org [College of Pharmacy, CMRI, Research Institute of Pharmaceutical Sciences, BK21 Plus KNU Multi-Omics Based Creative Drug Research Team, Kyungpook National University, Daegu 41566 (Korea, Republic of)
Lysozyme, found in relatively high concentration in blood, saliva, tears, and milk, protects us from the ever-present danger of bacterial infection. Previous studies have reported proinflammatory responses of endothelial cells to the release of polyphosphate(PolyP). In this study, we examined the anti-inflammatory responses and mechanisms of lysozyme and its effects on PolyP-induced septic activities in human umbilical vein endothelial cells (HUVECs) and mice. The survival rates, septic biomarker levels, behavior of human neutrophils, and vascular permeability were determined in PolyP-activated HUVECs and mice. Lysozyme suppressed the PolyP-mediated vascular barrier permeability, upregulation of inflammatory biomarkers, adhesion/migration of leukocytes, and activation and/or production of nuclear factor-κB, tumor necrosis factor-α, and interleukin-6. Furthermore, lysozyme demonstrated protective effects on PolyP-mediated lethal death and the levels of the related septic biomarkers. Therefore, these results indicated the therapeutic potential of lysozyme on various systemic inflammatory diseases, such as sepsis or septic shock. -- Highlights: •PolyP is shown to be an important mediator of vascular inflammation. •Lysozyme inhibited PolyP-mediated hyperpermeability. •Lysozyme inhibited PolyP-mediated septic response. •Lysozyme reduced PolyP-induced septic mortality.
Chung, Jiwoo; Ku, Sae-Kwang; Lee, Suyeon; Bae, Jong-Sup
Lysozyme, found in relatively high concentration in blood, saliva, tears, and milk, protects us from the ever-present danger of bacterial infection. Previous studies have reported proinflammatory responses of endothelial cells to the release of polyphosphate(PolyP). In this study, we examined the anti-inflammatory responses and mechanisms of lysozyme and its effects on PolyP-induced septic activities in human umbilical vein endothelial cells (HUVECs) and mice. The survival rates, septic biomarker levels, behavior of human neutrophils, and vascular permeability were determined in PolyP-activated HUVECs and mice. Lysozyme suppressed the PolyP-mediated vascular barrier permeability, upregulation of inflammatory biomarkers, adhesion/migration of leukocytes, and activation and/or production of nuclear factor-κB, tumor necrosis factor-α, and interleukin-6. Furthermore, lysozyme demonstrated protective effects on PolyP-mediated lethal death and the levels of the related septic biomarkers. Therefore, these results indicated the therapeutic potential of lysozyme on various systemic inflammatory diseases, such as sepsis or septic shock. -- Highlights: •PolyP is shown to be an important mediator of vascular inflammation. •Lysozyme inhibited PolyP-mediated hyperpermeability. •Lysozyme inhibited PolyP-mediated septic response. •Lysozyme reduced PolyP-induced septic mortality.
Sajjadi, H; Jorjoran Shushtari, Z; Mahboubi, S; Rafiey, H; Salimi, Y
Understanding pathways that influence substance use potential (SUP) can help with effective substance use prevention interventions among adolescents. The aim of the present study is to contribute to a better understanding of the SUP of adolescents by examining the mediating role of social network quality in the SUP of Iranian adolescents. A cross-sectional study. Structural equation modeling was conducted to assess the hypothesized model that social network quality would mediate the association of family socio-economic status, a mental health disorder, and family smoking with addiction potential. The model shows a good fit to the data. Social network quality mediated the effect of family smoking on the SUP for boys. A mental health disorder had a positive significant direct effect on addiction potential for both girls and boys. Social network quality mediates the effect of family smoking on boys' addiction potential in the context of Iran. Educational programs based on local societal ways and cultural norms are recommended to change tobacco smoking behavior among family members. In addition, to prevent subsequent substance use among adolescents, more effort is needed to improve their mental health. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Identifying the causal mechanisms is becoming more essential in social and medical sciences. In the presence of treatment non-compliance, the Intent-To-Treated effect (hereafter, ITT effect) is identified as long as the treatment is randomized (Angrist et al., 1996). However, the mediated portion of effect is not identified without additional…
Zhu, Xiaohong; Caplan, Jeffrey; Mamillapalli, Padmavathi; Czymmek, Kirk; Dinesh-Kumar, Savithramma P
Programmed cell death (PCD) initiated at the pathogen-infected sites during the plant innate immune response is thought to prevent the development of disease. Here, we describe the identification and characterization of an ER-localized type IIB Ca2+-ATPase (NbCA1) that function as a regulator of PCD. Silencing of NbCA1 accelerates viral immune receptor N- and fungal-immune receptor Cf9-mediated PCD, as well as non-host pathogen Pseudomonas syringae pv. tomato DC3000 and the general elicitor cryptogein-induced cell death. The accelerated PCD rescues loss-of-resistance phenotype of Rar1, HSP90-silenced plants, but not SGT1-silenced plants. Using a genetically encoded calcium sensor, we show that downregulation of NbCA1 results in the modulation of intracellular calcium signalling in response to cryptogein elicitor. We further show that NbCAM1 and NbrbohB function as downstream calcium decoders in N-immune receptor-mediated PCD. Our results indicate that ER-Ca2+-ATPase is a component of the calcium efflux pathway that controls PCD during an innate immune response. PMID:20075858
Morrison, Amanda S.; Heimberg, Richard G.
The goal of the present studies was to examine whether attentional control, a self-regulatory attentional mechanism, mediates the effect of social anxiety on positive affect. We tested this mediation in two studies using undergraduate students selected to represent a broad range of severity of social anxiety. Self-report assessments of social anxiety, attentional control, and positive affect were collected in a cross-sectional design (Study 1) and in a longitudinal design with three assessment points (Study 2). Results of both studies supported the hypothesized mediational model. Specifically, social anxiety was inversely related to attentional control, which itself positively predicted positive affect. This mediation remained significant even when statistically controlling for the effects of depression. Additionally, the hypothesized model provided superior model fit to theoretically-grounded equivalent models in both studies. Implications of these findings for understanding diminished positive affect in social anxiety are discussed. PMID:23254261
Liou, Hsien-Chin; Peng, Zhong-Yan
The interactive functions of weblogs facilitate computer-mediated peer reviews for collaborative writing. As limited research has been conducted on examining the training effects of peer reviews on students' peer comments, their revision quality, and their perceptions when composing in weblogs, the present case study aims to fill the gap. Thirteen…
Basil, Michael D.
This study examined personal concern, perceived risk, and sexual behavior of 147 college students a year after Magic Johnson announced he tested positive for HIV (Human Immunodeficiency Virus). It found that identification mediates message effects, suggesting that a spokesperson with whom an audience can identify insures the greatest likelihood of…
... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Termination of mediation. 930.115... MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Secretarial Mediation § 930.115 Termination of mediation. Mediation shall terminate: (a) At any time the Federal and State agencies agree to a...
Shalova, Irina N; Lim, Jyue Yuan; Chittezhath, Manesh; Zinkernagel, Annelies S; Beasley, Federico; Hernández-Jiménez, Enrique; Toledano, Victor; Cubillos-Zapata, Carolina; Rapisarda, Annamaria; Chen, Jinmiao; Duan, Kaibo; Yang, Henry; Poidinger, Michael; Melillo, Giovanni; Nizet, Victor; Arnalich, Francisco; López-Collazo, Eduardo; Biswas, Subhra K
Sepsis is characterized by a dysregulated inflammatory response to infection. Despite studies in mice, the cellular and molecular basis of human sepsis remains unclear and effective therapies are lacking. Blood monocytes serve as the first line of host defense and are equipped to recognize and respond to infection by triggering an immune-inflammatory response. However, the response of these cells in human sepsis and their contribution to sepsis pathogenesis is poorly understood. To investigate this, we performed a transcriptomic, functional, and mechanistic analysis of blood monocytes from patients during sepsis and after recovery. Our results revealed the functional plasticity of monocytes during human sepsis, wherein they transited from a pro-inflammatory to an immunosuppressive phenotype, while enhancing protective functions like phagocytosis, anti-microbial activity, and tissue remodeling. Mechanistically, hypoxia inducible factor-1α (HIF1α) mediated this functional re-programming of monocytes, revealing a potential mechanism for their therapeutic targeting to regulate human sepsis. Copyright © 2015 Elsevier Inc. All rights reserved.
Full Text Available The present paper focuses on the effects of personality traits on the levels of Internet addiction and cyberchondria and their consequent effects on well-being. For the purposes of the research, mediation analyses were carried out, clarifying the influence of personality traits on well-being mediated by Internet addiction, cyberchondria and anxiety aroused by online health information seeking. It was established that Neuroticism leads to decreased well-being through the mediating influence of health anxiety, escalation and persistence of health concerns. Health anxiety is a mediator in the relationship between Openness to Experience and well-being. It was established that low levels of Agreeableness and Conscientiousness, and high levels of Openness, and Neuroticism, influence Internet addiction, which in turn leads to decreased well-being. Furthermore, we established the mediated influence of Internet addiction on the tendency for cyberchondria and health anxiety through using the Internet for health information and judgment biases.
Frazier, Patricia A.; Tix, Andrew P.; Barron, Kenneth E.
The goals of this article are to (a) describe differences between moderator and mediator effects; (b) provide nontechnical descriptions of how to examine each type of effect, including study design, analysis, and interpretation of results; (c) demonstrate how to analyze each type of effect; and (d) provide suggestions for further reading. The…
Like studies focused on the detection of a main or total effect, a principal consideration in the design of studies examining mediation is the power with which mediation effects can be detected if they exist (e.g., Raudenbush, 1997). However, unlike studies concerning the detection of main effects, literature has not established power formulas for…
Johansen, Stine Liv
Children’s play must nowadays be understood as a mediatized field in society and culture. Media – understood in a very broad sense - holds severe explanatory power in describing and understanding the practice of play, since play happens both with, through and inspired by media of different sorts........ In this presentation the case of ‘playing soccer’ will be outlined through its different mediated manifestations, including soccer games and programs on TV, computer games, magazines, books, YouTube videos and soccer trading cards....
Biesanz, Jeremy C; Falk, Carl F; Savalei, Victoria
Theoretical models specifying indirect or mediated effects are common in the social sciences. An indirect effect exists when an independent variable's influence on the dependent variable is mediated through an intervening variable. Classic approaches to assessing such mediational hypotheses ( Baron & Kenny, 1986 ; Sobel, 1982 ) have in recent years been supplemented by computationally intensive methods such as bootstrapping, the distribution of the product methods, and hierarchical Bayesian Markov chain Monte Carlo (MCMC) methods. These different approaches for assessing mediation are illustrated using data from Dunn, Biesanz, Human, and Finn (2007). However, little is known about how these methods perform relative to each other, particularly in more challenging situations, such as with data that are incomplete and/or nonnormal. This article presents an extensive Monte Carlo simulation evaluating a host of approaches for assessing mediation. We examine Type I error rates, power, and coverage. We study normal and nonnormal data as well as complete and incomplete data. In addition, we adapt a method, recently proposed in statistical literature, that does not rely on confidence intervals (CIs) to test the null hypothesis of no indirect effect. The results suggest that the new inferential method-the partial posterior p value-slightly outperforms existing ones in terms of maintaining Type I error rates while maximizing power, especially with incomplete data. Among confidence interval approaches, the bias-corrected accelerated (BC a ) bootstrapping approach often has inflated Type I error rates and inconsistent coverage and is not recommended; In contrast, the bootstrapped percentile confidence interval and the hierarchical Bayesian MCMC method perform best overall, maintaining Type I error rates, exhibiting reasonable power, and producing stable and accurate coverage rates.
Steady-state analysis of primary solvent isotope effects on enzyme-catalyzed reactions, mediated by solvent-shielded di- or triprotic groups on the enzyme, yields equations describing the upper limit of intramolecular isotopic discrimation. For diprotic groups [P/sub H]/[P/sub D/] = 3k/sub H//k/sub D/ + 3), and for triprotic groups [P/sub H/]/[P/sub D/] = [7(k/sub H//k/sub D/ 2 = 10k/sub H/k/sub D/ + 1]/[(k/sub H//k/sub D/) 2 + 10k/sub H//k/sub D/ + 7]. Given a normal intrinsic isotope effect of k/sub H//k/sub D/ = 7, maximal isotopic discrimation in 50:50 H 2 O:D 2 O is therefore 2.2 and 3.3, respectively, versus 1.0 for a monoprotic group. Intermediate values of isotope discrimination may be interpreted with respect to distinguishing enzyme-mediated catalytic mechanisms from those of direct transfer between solvent and substrate, and to identifying mediating groups, by comparisons of isotopic discrimination at high and low concentrations of substrates and by reference to intrinsic and intermolecular isotope effects
Di Noia, Jennifer; Prochaska, James O.
This study identified mediators of a Transtheoretical Model (TTM) intervention to increase fruit and vegetable consumption among economically disadvantaged African American adolescents (N = 549). Single-and multiple-mediator models were used to determine whether pros, cons, self-efficacy, and stages of change satisfied four conclusions necessary…
Di Blasi, Maria; Cavani, Paola; Pavia, Laura; Tosto, Crispino; La Grutta, Sabina; Lo Baido, Rosa; Giordano, Cecilia; Schimmenti, Adriano
The relationship between social anxiety (SA) and cannabis use among adolescents and young adults is a highly debated topic. In this cross-sectional study, we tested whether cannabis use expectancies mediated the association between SA and cannabis use severity in a sample of 343 young adults (74.3% male) who used cannabis. They completed self-report measures for the screening of problematic cannabis use (Cannabis Use Problems Identification Test) and SA symptoms (Social Interaction Anxiety Scale and Social Phobia Scale). A multiple mediation analysis was used to test whether marijuana effect expectancies mediate SA effect on problematic cannabis use. SA was negatively associated with cannabis use severity in this sample, and we found evidence that cannabis use expectancies fully mediated this relationship. Specifically, global negative effect expectancies influence the relationship between SA and problematic cannabis use. These findings may inform current prevention strategies and clinical intervention for young adults who use cannabis.
Maria Di Blasi
Full Text Available The relationship between social anxiety (SA and cannabis use among adolescents and young adults is a highly debated topic. In this cross-sectional study, we tested whether cannabis use expectancies mediated the association between SA and cannabis use severity in a sample of 343 young adults (74.3% male who used cannabis. They completed self-report measures for the screening of problematic cannabis use (Cannabis Use Problems Identification Test and SA symptoms (Social Interaction Anxiety Scale and Social Phobia Scale. A multiple mediation analysis was used to test whether marijuana effect expectancies mediate SA effect on problematic cannabis use. SA was negatively associated with cannabis use severity in this sample, and we found evidence that cannabis use expectancies fully mediated this relationship. Specifically, global negative effect expectancies influence the relationship between SA and problematic cannabis use. These findings may inform current prevention strategies and clinical intervention for young adults who use cannabis.
Yu, Nancy Xiaonan; Zhang, Jianxin; Chow, Amy Y M; Chan, Celia H Y; Chan, Cecilia L W
Fate control has been often misconceptualized as a superstitious belief and overlooked in health psychology. It is not known how this cultural belief might impact the well-being of Chinese people living with HIV. This study examined the protective role of fate control for well-being and the potential mediation effect of resilience. Participants in this study were rural patients who contracted HIV via commercial blood donation. In this cross-sectional survey, 250 participants completed measures of fate control, well-being, and resilience. The results showed that fate control and resilience were positively associated with well-being. Resilience mediated the association between fate control and well-being. Our findings provide insight into the adaptive function of fate control as a cognitive defensive mechanism and highlight the need to incorporate this cultural belief in developing culturally sensitive intervention programs for resilience enhancement tailored for this understudied population infected with HIV living in rural China.
Walters, Glenn D
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.
Elizur, Yoel; Somech, Lior Y
Parenting intervention (PI) is an effective treatment for children's conduct problems (CP) that has been shown to be mediated by improved parenting practices and parenting self-efficacy. Recently, Hitkashrut's randomized controlled trial demonstrated that ineffective parenting (IP) mediated effects on callous-unemotional (CU) traits and effortful control (EC), while controlling for more general treatment effects on CP. These temperament and personality-based features predict the formation of early-onset antisocial trajectories with poor long-term prognosis. The objective of this study was to use Hitkashrut's 3-wave dataset to test posttreatment EC and CU mediation of treatment effect on 1-year follow-up CP, and to determine whether mediation by each child-level potential mediator remains significant when tested concurrently with the parenting mediator. Parents of 209 3-5 year-old preschoolers (163 boys; 46 girls), with subclinical-clinical range CP were assigned to 14-session co-parent training groups (n = 140 couples), or to minimal intervention control groups (n = 69 couples). Assessments were based on both parents' questionnaires. An intent-to-treat analysis showed that EC and CU traits simultaneously mediated treatment effects on CP in one EC/CU mediational model. The concurrent testing of child- and parent-level mediators showed mediation by IP and CU traits in the CU/IP model, and IP mediation in the EC/IP model. Similar results were obtained in mediational analyses that controlled for the shared variance between the mediators and CP at T2. Overall, the findings support an intervention model of coaching parents of high-CP children to promote moral self-regulatory competencies while concurrently applying behavioral methods that directly target CP.
Kaptein, M.C.; Castaneda, D.; Fernandez, N.; Nass, C.
The feeling of connectedness experienced in computer-mediated relationships can be explained by the similarity-attraction effect (SAE). Though SAE is well established in psychology, the effects of some types of similarity have not yet been explored. In 2 studies, we demonstrate similarity-attraction
Full Text Available In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting such an analysis. The package is organized into two distinct approaches. Using the model-based approach, researchers can estimate causal mediation effects and conduct sensitivity analysis under the standard research design. Furthermore, the design-based approach provides several analysis tools that are applicable under different experimental designs. This approach requires weaker assumptions than the model-based approach. We also implement a statistical method for dealing with multiple (causally dependent mediators, which are often encountered in practice. Finally, the package also offers a methodology for assessing causal mediation in the presence of treatment noncompliance, a common problem in randomized trials.
Lecheler, S.; Schuck, A.R.T.; de Vreese, C.H.
The underlying psychological processes that enable framing effects are often described as cognitive. Yet, recent studies suggest that framing effects may also be mediated by emotional response. The role of specific emotions in mediating the framing effect process, however, has yet to be fully
Pentz, M A
Several types of prevention programs have shown effects on delaying or reducing youth tobacco use for periods of 1-5 years or more. These are referred to as evidence-based programs. However, they are not widely used. At the same time, with few exceptions, adolescent tobacco use rates have been stable or have increased in the 1990s. The challenge for prevention is to identify critical components shared by effective prevention programs--that is, components most associated with effect, and then to evaluate factors that are most likely to promote adoption, implementation, and diffusion of effective programs across schools and communities in the United States. Effective tobacco prevention programs focus on counteracting social influences on tobacco use, include either direct training of youth in resistance and assertiveness skills or, for policy and community organization interventions, direct or indirect (through adults) training in community activism, and are mainly theory-based, with an emphasis on three levels of theory: (a) personal (attitudes, normative expectations, and beliefs); (b) social (social or group behavior); and/or (c) environmental (communications and diffusion). Program effects increase with the use of booster sessions, standardized implementor training and support, multiple program components, and multiple levels of theory. Overall, multi-component community programs that have a school program as a basis, with supportive parent, media, and community organization components, have shown the most sustained effects on tobacco use. Positive program adoption by the school or community, extent and quality of program implementation, and existence of credible networks of leaders to promote the program are critical for any effect. Research on predictors of adoption, implementation, and diffusion of evidence-based programs is scanty relative to outcome research. In addition, more research is needed on why multi-component programs appear to be most effective
JaKa, Meghan M; Sherwood, Nancy E; Flatt, Shirley W; Pacanowski, Carly R; Pakiz, Bilgé; Thomson, Cynthia A; Rock, Cheryl L
Understanding the degree to which eating behaviors, such as disinhibition and restraint, are associated with weight loss and weight loss maintenance could contribute to further refinement of effective weight management intervention strategies. The purpose of this analysis was to examine if these factors mediate weight loss or weight loss maintenance using data from a randomized controlled trial testing a commercial weight loss program that delivered behavioral counseling and structured meal plans including prepackaged foods. Mediation analyses were used to examine whether changes in disinhibition and restraint mediated the relationship between intervention and weight change during initial weight loss (0-6 months), continued weight loss (6-12 months), or weight loss maintenance (12-24 months) phases. Only decreases in disinhibition between baseline and 6 months mediated the intervention effect on initial weight loss. Our results suggest the mediation effects of these eating behaviors are modest and other factors contribute to a larger, more complex long-term weight loss prognosis.
Bramsen, Rikke H; Lasgaard, Mathias; Koss, Mary P; Shevlin, Mark; Elklit, Ask; Banner, Jytte
The present study modeled the direct relationship between child sexual abuse (CSA) and adolescent peer-to-peer sexual victimization (APSV) and the mediated effect via variables representing the number of sexual partners, sexual risk behavior, and signaling sexual boundaries. A cross-sectional study on the effect of CSA on APSV was conducted, utilizing a multiple mediator model. Mediated and direct effects in the model were estimated employing Mplus using bootstrapped percentile based confidence intervals to test for significance of mediated effects. The study employed 327 Danish female adolescents with a mean age of 14.9 years (SD = 0.5). The estimates from the mediational model indicated full mediation of the effect of CSA on APSV via number of sexual partners and sexual risk behavior. The current study suggests that the link between CSA and APSV was mediated by sexual behaviors specifically pertaining to situations of social peer interaction, rather than directly on prior experiences of sexual victimization. The present study identifies a modifiable target area for intervention to reduce adolescent sexual revictimization. © 2013 American Orthopsychiatric Association.
Park, Soojin; Kürüm, Esra
Randomized experiments are often complicated because of treatment noncompliance. This challenge prevents researchers from identifying the mediated portion of the intention-to-treated (ITT) effect, which is the effect of the assigned treatment that is attributed to a mediator. One solution suggests identifying the mediated ITT effect on the basis of the average causal mediation effect among compliers when there is a single mediator. However, considering the complex nature of the mediating mechanisms, it is natural to assume that there are multiple variables that mediate through the causal path. Motivated by an empirical analysis of a data set collected in a randomized interventional study, we develop a method to estimate the mediated portion of the ITT effect when both multiple dependent mediators and treatment noncompliance exist. This enables researchers to make an informed decision on how to strengthen the intervention effect by identifying relevant mediators despite treatment noncompliance. We propose a nonparametric estimation procedure and provide a sensitivity analysis for key assumptions. We conduct a Monte Carlo simulation study to assess the finite sample performance of the proposed approach. The proposed method is illustrated by an empirical analysis of JOBS II data, in which a job training intervention was used to prevent mental health deterioration among unemployed individuals. Copyright © 2018 John Wiley & Sons, Ltd.
Esser, Peter; Mehnert, Anja; Johansen, Christoffer
OBJECTIVE: Because cancer-related stigmatization is prevalent but difficult to change, research on its impact on psychological burden and respective intervening variables is needed. Therefore, we investigated the effect of stigmatization on depressive symptomatology and whether body image mediates...... this relationship. METHODS: This bicentric study assessed patients of 4 major tumor entities. We measured stigmatization (SIS-D), depressive symptomatology (PHQ-9), and body image (FKB-20). Applying multiple mediator analyses, we calculated the total effect of stigmatization on depressive symptomatology...
Nima, Ali Al; Rosenberg, Patricia; Archer, Trevor; Garcia, Danilo
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 differ...
Full Text Available During the course of their ontogenesis, plants are continuously exposed to a large variety of abiotic stress factors which can damage tissues and jeopardize the survival of the organism unless properly countered. While animals can simply escape and thus evade stressors, plants as sessile organisms have developed complex strategies to withstand them. When the intensity of a detrimental factor is high, one of the defense programs employed by plants is the induction of programmed cell death (PCD. This is an active, genetically controlled process which is initiated to isolate and remove damaged tissues thereby ensuring the survival of the organism. The mechanism of PCD induction usually includes an increase in the levels of reactive oxygen species (ROS which are utilized as mediators of the stress signal. Abiotic stress-induced PCD is not only a process of fundamental biological importance, but also of considerable interest to agricultural practice as it has the potential to significantly influence crop yield. Therefore, numerous scientific enterprises have focused on elucidating the mechanisms leading to and controlling PCD in response to adverse conditions in plants. This knowledge may help to develop novel strategies to obtain more resilient crop varieties with improved tolerance and enhanced productivity. The aim of the present review is to summarize the recent advances in research on ROS-induced PCD related to abiotic stress and the role of the organelles in the process.
Talloen, Wouter; Moerkerke, Beatrijs; Loeys, Tom; De Naeghel, Jessie; Van Keer, Hilde; Vansteelandt, Stijn
To assess the direct and indirect effect of an intervention, multilevel 2-1-1 studies with intervention randomized at the upper (class) level and mediator and outcome measured at the lower (student) level are frequently used in educational research. In such studies, the mediation process may flow through the student-level mediator (the within…
Buffart, Laurien M; Newton, Robert U; Chinapaw, Mai J; Taaffe, Dennis R; Spry, Nigel A; Denham, James W; Joseph, David J; Lamb, David S; Brug, Johannes; Galvão, Daniel A
The current study examined effects, moderators (for whom), and mediators (working mechanisms) of 12 months of exercise on health-related quality of life (HRQoL) in older long-term survivors of prostate cancer. In total, 100 men aged 71.7 years (standard deviation, 6.4 years) were randomly assigned to 6 months of supervised aerobic and resistance exercise followed by 6 months of a home-based exercise maintenance program (EX group) or printed education material regarding physical activity for 12 months (PA group). Assessments took place at baseline and after 6 and 12 months. Generalized estimating equations were used to study the effects of EX versus PA on HRQoL at 6 and 12 months, adjusting for baseline HRQoL. The authors examined potential sociodemographic and clinical moderators by adding interaction terms, and potential physical and psychological mediators using the product-of-coefficients test. At 6 months, significant beneficial effects were found for global QoL, physical function, and social function in the EX group compared with the PA group. For physical function, beneficial effects were sustained at 12 months. Moderation analyses demonstrated larger effects of EX versus PA for patients who were married, started exercising sooner after their diagnosis, and previously used bisphosphonates. Changes in lower body functional performance significantly mediated the effect of EX on global QoL, physical function, and social function. No mediating effects on HRQoL were found for aerobic fitness, physical activity, fatigue, distress, or falls self-efficacy. Aerobic and resistance exercise appears to have beneficial effects on HRQoL among older, long-term survivors of prostate cancer. Effects were moderated by marital status, time since diagnosis, and use of bisphosphonates, and were mediated by lower body functional performance. © 2015 American Cancer Society.
Full Text Available The purpose of this study is to analyze the effect of the bank’s image and trust on customer satisfaction, as well as the effect of the image of the bank, trust, and satisfaction on customer loyalty. The study used sample of 100 people who were taken by purposive sampling technique. This research utilized multiple linear regression analysis and path analysis. Based on the hypothesis test, the results show that the image of the bank was significantly has positive effect on customer satisfaction, but trust has no significant effect on customer satisfaction. In addition, the bank’s image has no significant effect on customer loyalty. Moreover, trust and customer satisfaction significantly have positive effect on customer loyalty. Mediation test shows that customer satisfaction mediates the effect of the bank’s image on customer loyalty and customer satisfaction does not mediate trust on customer loyalty. Info
... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Secretarial mediation efforts. 930.114... MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Secretarial Mediation § 930.114 Secretarial mediation efforts. (a) Following the close of the hearing, the hearing officer shall transmit the...
Ahmad, M. F.; Zakuan, N.; Rasi, Raja Zuraidah R. M.; Hisyamudin, M. N. N.
Total Quality Management (TQM) is vital management tool in ensuring a company can success in the continuously growing competition in the global market. In order to survive in the global market with intense competition amongst regions and enterprises, the adoption of tools and techniques are essential in improving business performance. However, only few previous studies have examined the mediators and moderators between TQM and business performance. This present research proposed a TQM performance model with mediator effect of TPM with structural equation modelling, which is a more comprehensive model for developing countries, specifically for Malaysia. A questionnaire was prepared and sent to 1500 companies from automotive industry and the related vendors in Malaysia, giving a 21.3 per cent rate. The result concludes that TPM is partial mediation between and TQM and Business Performance with indirect effect (IE) is 0.25 which can be categorised as high mediator effect.
Cutbush, Stacey; Williams, Jason; Miller, Shari
This longitudinal study tested whether sexual harassment perpetration mediates the relationship between bullying perpetration and teen dating violence (TDV) perpetration and tested moderated mediation by assessing whether the developmental pathway varies by gender among middle school-aged youth. Although TDV has been associated with bullying and sexual harassment, the developmental relationship among all three behaviors has rarely been examined, especially by gender. The data were collected from one cohort of seventh grade middle school students (N = 612) from four schools. Students were surveyed every 6 months during seventh and eighth grades for a total of four waves of data collection. Structural equation modeling (SEM) was conducted to address the study aims, consisting of three stages: measurement models, mediation, and moderated mediation (otherwise known as Contrast of Mediated Effects). Results indicate no evidence of mediation. However, in the overall model, bullying and sexual harassment both emerged as significant predictors of TDV at a later time point. Among girls, only bullying significantly predicted TDV at a later time point, and, among boys, only sexual harassment significantly predicted TDV at a later time point. Prevention programs that target bullying and sexual harassment perpetration may reduce later perpetration of TDV. Further research is needed to disentangle the temporal relationships between these aggressive behaviors among youth.
Hur, Ji-Won; Kim, Won-Joong; Kim, Yong-Ku
Suicidal probability is an actual tendency including negative self-evaluation, hopelessness, suicidal ideation, and hostility. The purpose of this study was to examine the role of psychosocial variances in the suicidal probability of adolescents, especially the role of mediating variance. This study investigated the mediating effects of psychosocial factors such as depression, anxiety, self-esteem, stress, and social support on the suicidal probability among 1,586 adolescents attending middle and high schools in the Kyunggi Province area of South Korea. The relationship between depression and anxiety/suicidal probability was mediated by both social resources and self-esteem. Furthermore, the influence of social resources was mediated by interpersonal and achievement stress as well as self-esteem. This study suggests that suicidal probability in adolescents has various relationships, including mediating relations, with several psychosocial factors. The interventions on suicidal probability in adolescents should focus on social factors as well as clinical symptoms.
Hong, Guanglei; Deutsch, Jonah; Hill, Heather D.
Conventional methods for mediation analysis generate biased results when the mediator--outcome relationship depends on the treatment condition. This article shows how the ratio-of-mediator-probability weighting (RMPW) method can be used to decompose total effects into natural direct and indirect effects in the presence of treatment-by-mediator…
Tingley, Dustin; Yamamoto, Teppei; Hirose, Kentaro; Keele, Luke; Imai, Kosuke
In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting su...
Kuster, Farah; Orth, Ulrich; Meier, Laurenz L
Previous research supports the vulnerability model of low self-esteem and depression, which states that low self-esteem operates as a prospective risk factor for depression. However, it is unclear which processes mediate the effect of low self-esteem. To test for the mediating effect of rumination, the authors used longitudinal mediation models, which included exclusively prospective effects and controlled for autoregressive effects of the constructs. Data came from 663 individuals (aged 16 to 62 years), who were assessed 5 times over an 8-month period. The results indicated that low self-esteem predicted subsequent rumination, which in turn predicted subsequent depression, and that rumination partially mediated the prospective effect of low self-esteem on depression. These findings held for both men and women, and for both affective-cognitive and somatic symptoms of depression. Future studies should test for the mediating effects of additional intrapersonal and interpersonal processes.
Richardson, Caroline R; Buis, Lorraine R; Janney, Adrienne W; Goodrich, David E; Sen, Ananda; Hess, Michael L; Mehari, Kathleen S; Fortlage, Laurie A; Resnick, Paul J; Zikmund-Fisher, Brian J; Strecher, Victor J; Piette, John D
Approximately half of American adults do not meet recommended physical activity guidelines. Face-to-face lifestyle interventions improve health outcomes but are unlikely to yield population-level improvements because they can be difficult to disseminate, expensive to maintain, and inconvenient for the recipient. In contrast, Internet-based behavior change interventions can be disseminated widely at a lower cost. However, the impact of some Internet-mediated programs is limited by high attrition rates. Online communities that allow participants to communicate with each other by posting and reading messages may decrease participant attrition. Our objective was to measure the impact of adding online community features to an Internet-mediated walking program on participant attrition and average daily step counts. This randomized controlled trial included sedentary, ambulatory adults who used email regularly and had at least 1 of the following: overweight (body mass index [BMI] ≥ 25), type 2 diabetes, or coronary artery disease. All participants (n = 324) wore enhanced pedometers throughout the 16-week intervention and uploaded step-count data to the study server. Participants could log in to the study website to view graphs of their walking progress, individually-tailored motivational messages, and weekly calculated goals. Participants were randomized to 1 of 2 versions of a Web-based walking program. Those randomized to the "online community" arm could post and read messages with other participants while those randomized to the "no online community" arm could not read or post messages. The main outcome measures were participant attrition and average daily step counts over 16 weeks. Multiple regression analyses assessed the effect of the online community access controlling for age, sex, disease status, BMI, and baseline step counts. Both arms significantly increased their average daily steps between baseline and the end of the intervention period, but there were no
Zucchini, Leon; Claussen, Jörg; Trüg, Moritz
. Alternatively, research on strategic discounting suggests that small operators use on-net discounts to advertise with low on-net prices. We test the relative strength of these effects using data on tariff setting in German mobile telecommunications between 2001 and 2009. We find that large operators are more......Mobile telecommunication operators routinely charge subscribers lower prices for calls on their own network than for calls to other networks (on-net discounts). Studies on tariff-mediated network effects suggest this is due to large operators using on-net discounts to damage smaller rivals...
Huang, Jin; Oshima, Karen M. Matta; Kim, Youngmi
Using two waves of data from the Child Development Supplement in the Panel Study of Income Dynamics, this study investigates whether parental characteristics (parenting stress, parental warmth, psychological distress, and parent’s self-esteem) mediate household food insecurity’s relations with child behavior problems. Fixed-effects analyses examine data from a low-income sample of 416 children from 249 households. This study finds that parenting stress mediates the effects of food insecurity ...
Yates, Brian T; Mannix, Danyelle; Freed, Michael C; Campbell, Jean; Johnsen, Matthew; Jones, Kristine; Blyler, Crystal R
Examine cost differences between Consumer Operated Service Programs (COSPs) as possibly determined by a) size of program, b) use of volunteers and other donated resources, c) cost-of-living differences between program locales, d) COSP model applied, and e) delivery system used to implement the COSP model. As part of a larger evaluation of COSP, data on operating costs, enrollments, and mobilization of donated resources were collected for eight programs representing three COSP models (drop-in centers, mutual support, and education/advocacy training). Because the 8 programs were operated in geographically diverse areas of the US, costs were examined with and without adjustment for differences in local cost of living. Because some COSPs use volunteers and other donated resources, costs were measured with and without these resources being monetized. Scale of operation also was considered as a mediating variable for differences in program costs. Cost per visit, cost per consumer per quarter, and total program cost were calculated separately for funds spent and for resources donated for each COSP. Differences between COSPs in cost per consumer and cost per visit seem better explained by economies of scale and delivery system used than by cost-of-living differences between program locations or COSP model. Given others' findings that different COSP models produce little variation in service effectiveness, minimize service costs by maximizing scale of operation while using a delivery system that allows staff and facilities resources to be increased or decreased quickly to match number of consumers seeking services.
Full Text Available Connie White-Williams,1 Kathleen L Grady,2 Pariya Fazeli,1 Susan Myers,1 Linda Moneyham,3 Karen Meneses,3 Bruce Rybarczyk4 1University of Alabama Medical Center, Birmingham, AL, USA; 2Division of Cardiac Surgery, Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; 3School of Nursing, University of Alabama at Birmingham, Birmingham, AL, USA; 4Department of Psychology, Clinical Psychology Program, Virginia Commonwealth University, Richmond, VA, USA Abstract: The purpose of this research was to examine whether satisfaction with social support and coping effectiveness mediate the relationship between stress and health-related quality of life (HRQOL 5 years after heart transplantation. Data were collected from 212 heart transplant patients (80% male, 92% white, mean age 59.9 years at four United States sites using the Heart Transplant Stressor Scale, Social Support Index, Jalowiec Coping Scale, and Quality of Life Index. Using Baron and Kenny's approach, a series of regression equations for mediation revealed that both satisfaction with social support and coping partially mediated the relationship between perceived stress and HRQOL. Understanding the relationships of social support, stress, and coping on patients' HRQOL is important for the development of interventions to provide optimal patient care. Keywords: heart transplantation, social support, coping, stress, mediation
Nakajima, Miho; Hattori, Yosuke; Tanno, Yoshihiko
Previous studies have shown that two types of private self-consciousness result in opposing effects on depression; one of which is self-rumination, which leads to maladaptive effect, and the other is self-reflection, which leads to an adaptive effect. Although a number of studies have examined the mechanism of the maladaptive effect of self-rumination, only a few studies have examined the mechanism of the adaptive effect of self-reflection. The present study examined the process of how self-reflection affected depression adaptively, Based on the previous findings, we proposed a hypothetical model assuming that hardiness acts as a mediator of self-reflection. To test the validity of the model, structural equation modeling analysis was performed with the cross-sectional data of 155 undergraduate students. The results. suggest that the hypothetical model is valid. According to the present results and previous findings, it is suggested that self-reflection is associated with low levels of depression and mediated by "rich commitment", one component of hardiness.
Kim, Ji Young; Lee, Kyunghee
The purpose of this study was to examine the moderating mediation effect of self-esteem on the relations among adolescents' abuse experiences, depression and anxiety, and suicidal ideation. The participants were selected using secondary data from a population in the 2012 Korea Welfare Panel Survey (KOWEPS). Data were analyzed using SPSS 15.0 and SPSS Macro, and bootstrapping and hierarchical regression analysis were performed to analyze multilevel models. First, analysis of the mediating effect of the adolescents' abuse showed that there was significant mediating influence between suicidal ideation and depression and anxiety. Second, hierarchical regression analysis showed that self-esteem had significant mediation effect on depression and anxiety in adolescents' suicidal ideation. Third, SPSS Macro showed that self-esteem also significantly moderated the mediating effect of adolescents' abuse experiences on suicidal ideation through depression and anxiety. The study results suggest that in future research on adolescent's abuse experience, the risk of suicide in depression and anxiety scores should be selected through evaluation of each individual's self-esteem scale. Coping strategies with immediate early intervention should be suggested.
Full Text Available The scales of the African Viper Bitis arietans were tested for optical effects. Spectral intensity was recorded at incident angles over the visible spectrum for dark, pale, and ventral scale regions. The lowest spectral intensity recordings were associated with scales which have the greatest level of micro-structuring. Our results indicate that scale appearance in B. arietans is a product of microstructure-mediated optical effects. The optical effect may play a role in improving the ecological performance of the snake in its natural environment.
Steen, Johan; Loeys, Tom; Moerkerke, Beatrijs; Vansteelandt, Stijn
The advent of counterfactual-based mediation analysis has triggered enormous progress on how, and under what assumptions, one may disentangle path-specific effects upon combining arbitrary (possibly nonlinear) models for mediator and outcome. However, current developments have largely focused on single mediators because required identification assumptions prohibit simple extensions to settings with multiple mediators that may depend on one another. In this article, we propose a procedure for obtaining fine-grained decompositions that may still be recovered from observed data in such complex settings. We first show that existing analytical approaches target specific instances of a more general set of decompositions and may therefore fail to provide a comprehensive assessment of the processes that underpin cause-effect relationships between exposure and outcome. We then outline conditions for obtaining the remaining set of decompositions. Because the number of targeted decompositions increases rapidly with the number of mediators, we introduce natural effects models along with estimation methods that allow for flexible and parsimonious modeling. Our procedure can easily be implemented using off-the-shelf software and is illustrated using a reanalysis of the World Health Organization's Large Analysis and Review of European Housing and Health Status (WHO-LARES) study on the effect of mold exposure on mental health (2002-2003). © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: email@example.com.
Simons, Nadja K.; Gossner, Martin M.; Lewinsohn, Thomas M.; Boch, Steffen; Lange, Markus; Müller, Jörg; Pašalić, Esther; Socher, Stephanie A.; Türke, Manfred; Fischer, Markus; Weisser, Wolfgang W.
Intensive land use is a driving force for biodiversity decline in many ecosystems. In semi-natural grasslands, land-use activities such as mowing, grazing and fertilization affect the diversity of plants and arthropods, but the combined effects of different drivers and the chain of effects are largely unknown. In this study we used structural equation modelling to analyse how the arthropod communities in managed grasslands respond to land use and whether these responses are mediated through changes in resource diversity or resource quantity (biomass). Plants were considered resources for herbivores which themselves were considered resources for predators. Plant and arthropod (herbivores and predators) communities were sampled on 141 meadows, pastures and mown pastures within three regions in Germany in 2008 and 2009. Increasing land-use intensity generally increased plant biomass and decreased plant diversity, mainly through increasing fertilization. Herbivore diversity decreased together with plant diversity but showed no response to changes in plant biomass. Hence, land-use effects on herbivore diversity were mediated through resource diversity rather than quantity. Land-use effects on predator diversity were mediated by both herbivore diversity (resource diversity) and herbivore quantity (herbivore biomass), but indirect effects through resource quantity were stronger. Our findings highlight the importance of assessing both direct and indirect effects of land-use intensity and mode on different trophic levels. In addition to the overall effects, there were subtle differences between the different regions, pointing to the importance of regional land-use specificities. Our study underlines the commonly observed strong effect of grassland land use on biodiversity. It also highlights that mechanistic approaches help us to understand how different land-use modes affect biodiversity. PMID:25188423
Huang, Jing; Yuan, Ying
Most existing methods for mediation analysis assume that mediation is a stationary, time-invariant process, which overlooks the inherently dynamic nature of many human psychological processes and behavioral activities. In this article, we consider mediation as a dynamic process that continuously changes over time. We propose Bayesian multilevel time-varying coefficient models to describe and estimate such dynamic mediation effects. By taking the nonparametric penalized spline approach, the proposed method is flexible and able to accommodate any shape of the relationship between time and mediation effects. Simulation studies show that the proposed method works well and faithfully reflects the true nature of the mediation process. By modeling mediation effect nonparametrically as a continuous function of time, our method provides a valuable tool to help researchers obtain a more complete understanding of the dynamic nature of the mediation process underlying psychological and behavioral phenomena. We also briefly discuss an alternative approach of using dynamic autoregressive mediation model to estimate the dynamic mediation effect. The computer code is provided to implement the proposed Bayesian dynamic mediation analysis. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Vanessa N Durand
Full Text Available This longitudinal secondary analysis examined which early language and speech abilities are associated with school-aged reading skills, and whether these associations are mediated by cognitive ability. We analyzed vocabulary, syntax, speech sound maturity, and cognition in a sample of healthy children at age 3 years (N=241 in relation to single word reading (decoding, comprehension, and oral reading fluency in the same children at age 9 to 11 years. All predictor variables and the mediator variable were associated with the three reading outcomes. The predictor variables were all associated with cognitive abilities, the mediator. Cognitive abilities partially mediated the effects of language on reading. After mediation, decoding was associated with speech sound maturity; comprehension was associated with receptive vocabulary; and oral fluency was associated with speech sound maturity, receptive vocabulary, and syntax. In summary, all of the effects of language on reading could not be explained by cognition as a mediator. Specific components of language and speech skills in preschool made independent contributions to reading skills 6 to 8 years later. These early precursors to later reading skill represent potential targets for early intervention to improve reading.
Kaptein, M.C.; Castaneda, D.; Fernandez, N.; Nass, C.
The feeling of connectedness experienced in computer-mediated relationships can be explained by the similarity-attraction effect (SAE). Though SAE is well established in psychology, the effects of some types of similarity have not yet been explored. In 2 studies, we demonstrate similarity-attraction
Vuorre, Matti; Bolger, Niall
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.
... 7 Agriculture 7 2010-01-01 2010-01-01 false Reports by qualifying States receiving mediation grant... SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS CERTIFIED STATE MEDIATION PROGRAM § 785.8 Reports by qualifying States receiving mediation grant funds. (a) Annual report by certified State...
Full Text Available The purpose of the present study is to investigate the mediational role of automatic thoughts on the association between self-esteem and academic motivation. Differences would be analyzed separated according to gender and faculty studied. Participants of the study are 210 undergraduate students (%42.4, 89 women; %57.6, 121 men selected randomly from counselling and intelligence teaching departments of University in Northern Cyprus. All permissions were taken. In order of the aim of self-esteem were assessed using ‘Rosenberg Self-Esteem Questionarie’’. In addition academic motivation was measured by ‘Academic Motivation Scale’ and ‘Automatic Thoughts Inventory’was used in measuring automatic thought levels of the participants. At this study relational screening analysis used, and mediation effect of automatic thoughts were analyzed using Baron and Kenny’s (1986 mediation analysis method. Partial mediation effect of amotivation subscale was proved among self-esteem and negative automatic thought. Evaluating the total effect and direct effect, it is indicated that, the difference is 28% of indirect effect value. Amotivation is related to self esteem and negative automatic thoughts
Wu, Pei-Chen; Kuo, Shin-Ting
The primary purpose of this study was to utilize a multidimensional perspective to examine whether children's self-concept served as a mediator between academic achievement and depression, and to further investigate whether this mediation effect was moderated by the ages of children. The participants consisted of 632 Taiwanese children in the…
Wu, Jyh-Jeng; Chen, Ying-Hueih; Chien, Shu-Hua
Impulse purchasing is a pervasive yet relatively little-discussed phenomenon. This study investigates the effect of impulse purchases on trust, as well as the mediating effect of stickiness and the mental budgeting account in the group buying context. Questionnaires were sent to group buying participants. The results show that impulse purchases have a positive effect on trust and that both stickiness and the mental budgeting account present a mediating effect.
Zaccard, Colleen R; Watkins, Simon C; Kalinski, Pawel; Fecek, Ronald J; Yates, Aarika L; Salter, Russell D; Ayyavoo, Velpandi; Rinaldo, Charles R; Mailliard, Robbie B
The ability of dendritic cells (DC) to mediate CD4(+) T cell help for cellular immunity is guided by instructive signals received during DC maturation, as well as the resulting pattern of DC responsiveness to the Th signal, CD40L. Furthermore, the professional transfer of antigenic information from migratory DC to lymph node-residing DC is critical for the effective induction of cellular immune responses. In this study we report that, in addition to their enhanced IL-12p70 producing capacity, human DC matured in the presence of inflammatory mediators of type 1 immunity are uniquely programmed to form networks of tunneling nanotube-like structures in response to CD40L-expressing Th cells or rCD40L. This immunologic process of DC reticulation facilitates intercellular trafficking of endosome-associated vesicles and Ag, but also pathogens such HIV-1, and is regulated by the opposing roles of IFN-γ and IL-4. The initiation of DC reticulation represents a novel helper function of CD40L and a superior mechanism of intercellular communication possessed by type 1 polarized DC, as well as a target for exploitation by pathogens to enhance direct cell-to-cell spread. Copyright © 2015 by The American Association of Immunologists, Inc.
Full Text Available This study was conducted to examine the effect of adequacy of benefits and distributive justice on personal outcomes (i.e., job satisfaction and organizational commitment using 583 usable questionnaires gathered from Malaysian public institutions of higher learning (PLEARNINGINSTITUTE sector. The outcomes of step-wise regression analysis showed that the inclusion of distributive justice in the analysis has increased the effect of adequacy of benefits on both job satisfaction and organizational commitment. Furthermore, the findings of this study confirm that distributive justice do act as a partial mediating variable in the benefits program models of the organizational sector sample. In addition, implications and limitations, as well as directions for future research are discussed.
Kim, Hyejin; Kim, Ji-Su; Choe, Kwisoon; Kwak, Yeunhee; Song, Jae-Seok
To test a model of the relationship between nurses' burnout and emotional labour using structural equation modelling to identify the mediating effects of workplace violence. Nurses are a group that experiences high emotional labour and are exposed to various types of violence in the clinical setting. Burnout is related to emotional labour as well as exposure of workplace violence, but alternatives to reduce burnout in the context of emotional labour (e.g. reduction of workplace violence) have not been extensively investigated. This study adopted a cross-sectional design. A convenience sample comprising 400 nurses from 4 university hospitals in Korea was selected from 10 - 30 October 2016. Data on nurses' level of emotional labour, burnout and workplace violence were collected from participants. A composite-indicator structural equation model was used to examine the mediation model. Overall, 356 nurses (89.0%) returned the completed questionnaires. Burnout was significantly and positively associated with emotional labour and workplace violence. In addition, workplace violence mediated the relationship between emotional labour and burnout related to the nursing job. The findings suggest that, to alleviate burnout in clinical nurses due to emotional labour, various programs and policy measures should be adopted to prevent their exposure to workplace violence and to enhance the organizational management of violence. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
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.
Menatti, Andrew R.; Weeks, Justin W.; Levinson, Cheri A.; McGowan, Maggie M.
Previous findings indicate that social anxiety and bulimia co-occur at high rates; one mechanism that has been proposed to link these symptom clusters is perfectionism. We tested meditational models among 167 female undergraduates in which maladaptive evaluative perfectionism concerns (MEPC; i.e., critical self-evaluative perfectionism) mediated the relationship between social anxiety and bulimic symptoms. Results from a first model indicated that MEPC mediated the relationship between fear of public scrutiny and bulimia symptoms. This indirect effect was significant above and beyond the indirect effects of maladaptive body-image cognitions and perfectionism specific to pure personal standards. A second model was tested with MEPC mediating the relationship between social interaction anxiety and bulimia symptoms. Similar results were obtained; however, in this model, a significant direct effect remained after partialing out the indirect effect of the mediators. Theoretical implications are discussed. PMID:24932054
Deerberg, Andrea; Sosna, Justyna; Thon, Lutz; Belka, Claus; Adam, Dieter
Programmed cell death (PCD) is essential for development and homeostasis of multicellular organisms and can occur by caspase-dependent apoptosis or alternatively, by caspase-independent PCD (ciPCD). Bcl-2, a central regulator of apoptosis, localizes to both mitochondria and the endoplasmic reticulum (ER). Whereas a function of mitochondrial and ER-specific Bcl-2 in apoptosis has been established in multiple studies, corresponding data for ciPCD do not exist. We utilized Bcl-2 constructs specifically localizing to mitochondria (Bcl-2 ActA), the ER (Bcl-2 cb5), both (Bcl-2 WT) or the cytosol/nucleus (Bcl-2 ΔTM) and determined their protective effect on ceramide-mediated ciPCD in transiently and stably transfected Jurkat cells. Expression of the constructs was verified by immunoblots. Ceramide-mediated ciPCD was induced by treatment with human recombinant tumor necrosis factor and determined by flow cytometric measurement of propidium iodide uptake as well as by optical analysis of cell morphology. Only wildtype Bcl-2 had the ability to efficiently protect from ceramide-mediated ciPCD, whereas expression of Bcl-2 solely at mitochondria, the ER, or the cytosol/nucleus did not prevent ceramide-mediated ciPCD. Our data suggest a combined requirement for both mitochondria and the ER in the induction and the signaling pathways of ciPCD mediated by ceramide
Full Text Available Abstract Background Programmed cell death (PCD is essential for development and homeostasis of multicellular organisms and can occur by caspase-dependent apoptosis or alternatively, by caspase-independent PCD (ciPCD. Bcl-2, a central regulator of apoptosis, localizes to both mitochondria and the endoplasmic reticulum (ER. Whereas a function of mitochondrial and ER-specific Bcl-2 in apoptosis has been established in multiple studies, corresponding data for ciPCD do not exist. Methods We utilized Bcl-2 constructs specifically localizing to mitochondria (Bcl-2 ActA, the ER (Bcl-2 cb5, both (Bcl-2 WT or the cytosol/nucleus (Bcl-2 ΔTM and determined their protective effect on ceramide-mediated ciPCD in transiently and stably transfected Jurkat cells. Expression of the constructs was verified by immunoblots. Ceramide-mediated ciPCD was induced by treatment with human recombinant tumor necrosis factor and determined by flow cytometric measurement of propidium iodide uptake as well as by optical analysis of cell morphology. Results Only wildtype Bcl-2 had the ability to efficiently protect from ceramide-mediated ciPCD, whereas expression of Bcl-2 solely at mitochondria, the ER, or the cytosol/nucleus did not prevent ceramide-mediated ciPCD. Conclusion Our data suggest a combined requirement for both mitochondria and the ER in the induction and the signaling pathways of ciPCD mediated by ceramide.
Full Text Available The effects of six non-dissolved redox mediators (RM immobilized in cellulose acetate beads on enhancing Cr(VI reduction by Mangrovibacter plantisponsor CR1 were investigated. In addition, the voltammetric behaviours and electron transfer capacities of the redox mediators were examined using electrochemical methods. Compared to the control beads, the Cr(VI bioreduction rate with 1-chloroanthraquinone cellulose acetate beads (1-CAQ/CA beads was increased up to 4.5-fold, which was mainly attributed to enhanced electron transfer by 1-CAQ. The redox mediators also improved the oxidation–reduction potential values of the Cr(VI bioreduction processes, which might assist in Cr(VI bioreduction. The role of the redox mediators was discussed based on the cyclic voltammetric characteristics (E0' of the redox mediators and the electrochemical impedance spectroscopy characteristics (Rct of the RM/CA beads. A linear correlation was found for the reaction constant k and the 1-CAQ concentration (C1-CAQ, which was k = 1.5674 C1-CAQ + 4.8506 (R2 = 0.9683. The Cr(VI bioreduction was affected by temperature, and the optimum pH for the Cr(VI bioreduction was 6.5. The results of repeated-batch operations showed that 1-CAQ/CA beads exhibited good stability and persistence. This study contributes to a better understanding of the effects of the redox mediator on Cr(VI bioreduction process and demonstrates its promising potential for environmental bioremediation applications.
This study examines to what extent corporations use sustainability control systems (SCS) to translate proactive sustainability strategy into corporate sustainability performance. The study investigates the mediating effect of SCS on the relationship between proactive sustainability strategy and corporate sustainability performance. Survey data were collected from top managers in 175 multinational and local corporations operating in Sri Lanka and analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). SCS were observed to only partially mediate the relationship between proactive sustainability strategy and corporate sustainability performance. The mediating effect of SCS is further examined under three sustainability strategies; environmental and social strategies reveal a partial mediation, while the economic strategy exhibits no mediation. The study also finds that (i) a proactive sustainability strategy is positively associated with SCS and corporate sustainability performance and (ii) SCS are positively associated with corporate sustainability performance. Copyright © 2017 Elsevier Ltd. All rights reserved.
Liu, Jianghong; Ulrich, Connie
Mediation statistical models help clarify the relationship between independent predictor variables and dependent outcomes of interest by assessing the impact of third variables. This type of statistical analysis is applicable for many clinical nursing research questions, yet its use within nursing remains low. Indeed, mediational analyses may help nurse researchers develop more effective and accurate prevention and treatment programs as well as help bridge the gap between scientific knowledge and clinical practice. In addition, this statistical approach allows nurse researchers to ask - and answer - more meaningful and nuanced questions that extend beyond merely determining whether an outcome occurs. Therefore, the goal of this paper is to provide a brief tutorial on the use of mediational analyses in clinical nursing research by briefly introducing the technique and, through selected empirical examples from the nursing literature, demonstrating its applicability in advancing nursing science.
Williams, Olajide; DeSorbo, Alexandra; Noble, James; Gerin, William
Low thrombolysis rates for acute ischemic stroke are linked to delays in seeking immediate treatment due to low public stroke awareness. We aimed to assess whether "Child-Mediated Stroke Communication" could improve stroke literacy of parents of children enrolled in a school-based stroke literacy program called Hip Hop Stroke. Parents of children aged 9 to 12 years from 2 public schools in Harlem, New York City, were recruited to participate in stroke literacy questionnaires before and after their child's participation in Hip Hop Stroke, a novel Child-Mediated Stroke Communication intervention delivered in school auditoriums. Parental recall of stroke information communicated through their child was assessed 1-week after the intervention. Fifth and sixth grade students (n=182) were enrolled into Hip Hop Stroke. One hundred two parents were approached in person to participate; 75 opted to participate and 71 completed both the pretest and post-test (74% response rate and 95% retention rate). Parental stroke literacy improved after the program; before the program, 3 parents of 75 (3.9%) were able to identify the 5 cardinal stroke symptoms, distracting symptom (chest pains), and had an urgent action plan (calling 911) compared with 21 of 71 parents (29.6%) postintervention (P<0.001). The FAST mnemonic was known by 2 (2.7%) of participants before the program versus 29 (41%) after program completion (P<0.001). Knowledge of stroke signs and symptoms remains low among residents of this high-risk population. The use of Child-Mediated Stroke Communication suggests that school children aged 9 to 12 years may be effective conduits of critical stroke knowledge to their parents.
Questions of mediation are often of interest in reasoning about mechanisms, and methods have been developed to address these questions. However, these methods make strong assumptions about the absence of confounding. Even if exposure is randomized, there may be mediator-outcome confounding variables. Inference about direct and indirect effects is particularly challenging if these mediator-outcome confounders are affected by the exposure because in this case these effects are not identified irrespective of whether data is available on these exposure-induced mediator-outcome confounders. In this paper, we provide a sensitivity analysis technique for natural direct and indirect effects that is applicable even if there are mediator-outcome confounders affected by the exposure. We give techniques for both the difference and risk ratio scales and compare the technique to other possible approaches. PMID:25580387
... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Request for Secretarial mediation. 930... RESOURCE MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Secretarial Mediation § 930.112 Request for Secretarial mediation. (a) The Secretary or other head of a Federal agency, or the...
Doss, Brian D; Mitchell, Alexandra; Georgia, Emily J; Biesen, Judith N; Rowe, Lorelei Simpson
Empirically based couple therapy results in significant improvements in relationship satisfaction for the average couple; however, further research is needed to identify mediators that lead to change and to ensure that improvements in mediators predict subsequent-not just concurrent-relationship satisfaction. In addition, given that much of the current literature on couple therapy examines outcomes in a research environment, it is important to examine mediators in a treatment-as-usual setting. To address these questions, 161 heterosexual couples (322 individuals) received treatment-as-usual couple therapy at one of two Veteran Administration Medical Centers (M = 5.0 and 13.0 sessions at the two sites) and were assessed before every session. The majority of couples were married (85%) and had been together for a median of 7.8 years (SD = 13). Participants were primarily White, non-Hispanic (69%), African American (21%), and White, Hispanic/Latino (8%). Individuals' own self-reported improvements in communication, emotional closeness, and psychological distress (but not frequency of behaviors targeted in treatment) mediated the effect of treatment on their subsequent relationship satisfaction. When all significant mediators were examined simultaneously, improvements in men's and women's emotional closeness and men's psychological distress independently mediated subsequent relationship satisfaction. In contrast, improvements in earlier relationship satisfaction mediated the effect of treatment only on subsequent psychological distress. This study identifies unique mediators of treatment effects and shows that gains in mechanisms predict subsequent relationship satisfaction. Future investigations should focus on the role of emotional closeness and psychological distress-constructs that have often been neglected-in couple therapy. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
Andersen, Ingelise; Gamborg, Michael; Osler, Merete
To investigate whether the effect of occupational grade on the risk of myocardial infarction (MI) is mediated by income with different aspects of income taken into account.......To investigate whether the effect of occupational grade on the risk of myocardial infarction (MI) is mediated by income with different aspects of income taken into account....
The goal of the proposed study was fourfold: (i) to examine the effects of parental alcoholism on adult offspring's self-esteem; (ii) to identify and test possible mediators and moderators of parental alcoholism effects on the self-esteem of adult offspring; (iii) to examine the utility and relevance of attachment theory (Bowlby J. (1969) Attachment and Loss: Vol. 1. Attachment. New York: Basic Books) in explaining parental alcoholism effects on self-esteem and (iv) to address some of the methodological limitations identified in past research on adult children of alcoholics (ACOA). Participants (N = 515) completed retrospective reports of parental alcoholism, family stressors, family communication patterns, parental attachment and a current measure of self-esteem. The results showed support for the detrimental effects of parental alcoholism on offspring self-esteem and offered partial support for family stressors as a mediator of parental alcoholism effects on parental attachment and parental attachment as a mediator of parental alcoholism effects on offspring self-esteem, respectively. Finally, support was found for family communication patterns as a moderator of the effects of family stressors on attachment. The study findings offer preliminary support for the utility of attachment theory in explicating parental alcoholism effects on the self-esteem of adult offspring. Findings from the present study make salient the need to consider factors beyond the identification of parental alcohol abuse when explicating individual differences in offspring self-esteem in adulthood. The identification of protective and risk factors can contribute to the development of optimal intervention strategies to help ACOAs better than simply the knowledge of family drinking patterns.
Lubans, David R; Smith, Jordan J; Morgan, Philip J; Beauchamp, Mark R; Miller, Andrew; Lonsdale, Chris; Parker, Philip; Dally, Kerry
The aim of this study was to explore the effect of the Active Teen Leaders Avoiding Screen-time (ATLAS) intervention on psychological well-being in adolescent boys and to examine the potential mediating mechanisms that might explain this effect. ATLAS was evaluated using a cluster randomized controlled trial in 14 secondary schools located in low-income communities (N = 361 adolescent boys, mean age = 12.7 ± .5 years). The 20-week intervention was guided by self-determination theory and involved: professional development for teachers, provision of fitness equipment to schools, enhanced school sport sessions, researcher-led seminars, a smartphone application, and parental strategies for reducing screen time. Assessments were conducted at baseline and immediately post intervention (8 months). Psychological well-being was measured using the Flourishing Scale. Motivational regulations (intrinsic, identified, introjected, controlled, and amotivation) and basic psychological needs (autonomy, competence, and relatedness) in school sport, muscular fitness, resistance training skill competency, and recreational screen time were examined as potential mediating mechanisms of the intervention effect. The intervention effect on well-being was small but statistically significant. Within a multiple mediator model, changes in autonomy needs satisfaction, recreational screen time, and muscular fitness significantly mediated the effect of the intervention on psychological well-being. In addition to the physical health benefits, targeted physical activity programs for adolescent boys may have utility for mental health promotion through the mechanisms of increasing autonomy support and muscular fitness and reducing screen time. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
Puttabyatappa, Muraly; Andriessen, Victoria; Mesquitta, Makeda; Zeng, Lixia; Pennathur, Subramaniam; Padmanabhan, Vasantha
Prenatal testosterone (T) excess in sheep leads to peripheral insulin resistance (IR), reduced adipocyte size, and tissue-specific changes, with liver and muscle but not adipose tissue being insulin resistant. To determine the basis for the tissue-specific differences in insulin sensitivity, we assessed changes in negative (inflammation, oxidative stress, and lipotoxicity) and positive mediators (adiponectin and antioxidants) of insulin sensitivity in the liver, muscle, and adipose tissues of control and prenatal T-treated sheep. Because T excess leads to maternal hyperinsulinemia, fetal hyperandrogenism, and functional hyperandrogenism and IR in their female offspring, prenatal and postnatal interventions with antiandrogen, flutamide, and the insulin sensitizer rosiglitazone were used to parse out the contribution of androgenic and metabolic pathways in programming and maintaining these defects. Results showed that (1) peripheral IR in prenatal T-treated female sheep is related to increases in triglycerides and 3-nitrotyrosine, which appear to override the increase in high-molecular-weight adiponectin; (2) liver IR is a function of the increase in oxidative stress (3-nitrotyrosine) and lipotoxicity; (3) muscle IR is related to lipotoxicity; and (4) the insulin-sensitive status of visceral adipose tissue appears to be a function of the increase in antioxidants that likely overrides the increase in proinflammatory cytokines, macrophages, and oxidative stress. Prenatal and postnatal intervention with either antiandrogen or insulin sensitizer had partial effects in preventing or ameliorating the prenatal T-induced changes in mediators of insulin sensitivity, suggesting that both pathways are critical for the programming and maintenance of the prenatal T-induced changes and point to potential involvement of estrogenic pathways. Copyright © 2017 Endocrine Society.
Fischer-Lokou, Jacques; Lamy, Lubomir; Guéguen, Nicolas; Dubarry, Alexandre
An experiment with 212 students (100 men, 112 women; M age = 18.3 years, SD = 0.9) was carried out to compare the effect of four techniques used by mediators on the number of agreements contracted by negotiators. Under experimental conditions, mediators were asked either to rephrase (reformulate) negotiators' words or to imitate them or to show active listening behavior, or finally, to use a free technique. More agreements were reached in the active listening condition than in both free and rephrase conditions. Furthermore, mediators in the active listening condition were perceived, by the negotiators, as more efficient than mediators using other techniques, although there was no significant difference observed between the active listening and imitation conditions. © The Author(s) 2016.
Shehzad, Adeeb; Qureshi, Munibah; Anwar, Muhammad Nabeel; Lee, Young Sup
Inflammation can promote the development of arthritis, obesity, cardiovascular, type II diabetes, pancreatitis, metabolic and neurodegenerative diseases, and certain types of cancer. Compounds isolated from plants have been practiced since ancient times for curing various ailments including inflammatory disorders and to support normal physiological functions. Curcumin (diferuloylmethane) is a yellow coloring agent, extracted from turmeric that has been used for the prevention and treatment of various inflammatory diseases. Numerous studies have shown that curcumin modulate multiple molecular targets and can be translated to the clinics for multiple therapeutic processes. There is compelling evidence that curcumin can block cell proliferation, invasion, and angiogenesis as well as reduced the prolonged survival of cancer cells. Curcumin mediates anti-inflammatory effect through downregulation of inflammatory cytokines, transcription factors, protein kinases, and enzymes that promote inflammation and development of chronic diseases. In addition, curcumin induces apoptosis through mitochondrial and receptor-mediated pathways by activating caspase cascades. Curcumin is a safe and nontoxic drug that has been reported to be well tolerated. Available clinical trials support the potential role of curcumin for treatment of various inflammatory disorders. However, curcumin's efficacy is hindered by poor absorption and low bioavailability, which limit its translation into clinics. This review outlines the potential pharmacological and clinical role of curcumin, which provide a gateway for the beneficial role of plant isolated compounds in treatment of various inflammatory diseases and cancer. © 2017 Institute of Food Technologists®.
Wilcox, Claire E; Tonigan, J Scott
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.
Soureti, A.; Hurling, R.; van Mechelen, W.; Cobain, M.; Chin A Paw, M.J.M.
Objective: The present study aimed to advance our understanding of health-related theory, that is, the alleged intention-behavior gap in an obese population. It examined the mediating effects of planning on the intention-behavior relationship and the moderated mediation effects of age, self-efficacy
Khanna, N; Khosla, R; Kohli, J
Intraperitoneal (i.p.) administration of (+/-) pentazocine (10, 30 & 50 mg/kg), a Sigma opioid agonist, resulted in a dose dependent anticonvulsant action against maximal electroshock seizures in mice. This anticonvulsant effect of pentazocine was not antagonized by both the doses of naloxone (1 and 10 mg/kg) suggesting thereby that its anticonvulsant action is probably mediated by Sigma opiate binding sites. Its anticonvulsant effect was potentiated by both the anticonvulsant drugs viz. diazepam and diphenylhydantoin. Morphine, mu opioid agonist, on the other hand, failed to protect the animals against maximal electroshock seizures when it was given in doses of 10-40 mg/kg body wt.
Emsley, Richard; Dunn, Graham; White, Ian R
Complex intervention trials should be able to answer both pragmatic and explanatory questions in order to test the theories motivating the intervention and help understand the underlying nature of the clinical problem being tested. Key to this is the estimation of direct effects of treatment and indirect effects acting through intermediate variables which are measured post-randomisation. Using psychological treatment trials as an example of complex interventions, we review statistical methods which crucially evaluate both direct and indirect effects in the presence of hidden confounding between mediator and outcome. We review the historical literature on mediation and moderation of treatment effects. We introduce two methods from within the existing causal inference literature, principal stratification and structural mean models, and demonstrate how these can be applied in a mediation context before discussing approaches and assumptions necessary for attaining identifiability of key parameters of the basic causal model. Assuming that there is modification by baseline covariates of the effect of treatment (i.e. randomisation) on the mediator (i.e. covariate by treatment interactions), but no direct effect on the outcome of these treatment by covariate interactions leads to the use of instrumental variable methods. We describe how moderation can occur through post-randomisation variables, and extend the principal stratification approach to multiple group methods with explanatory models nested within the principal strata. We illustrate the new methodology with motivating examples of randomised trials from the mental health literature.
Pinto, B M; Lynn, H; Marcus, B H; DePue, J; Goldstein, M G
In theory-based interventions for behavior change, there is a need to examine the effects of interventions on the underlying theoretical constructs and the mediating role of such constructs. These two questions are addressed in the Physically Active for Life study, a randomized trial of physician-based exercise counseling for older adults. Three hundred fifty-five patients participated (intervention n = 181, control n = 174; mean age = 65.6 years). The underlying theories used were the Transtheoretical Model, Social Cognitive Theory and the constructs of decisional balance (benefits and barriers), self-efficacy, and behavioral and cognitive processes of change. Motivational readiness for physical activity and related constructs were assessed at baseline, 6 weeks, and 8 months. Linear or logistic mixed effects models were used to examine intervention effects on the constructs, and logistic mixed effects models were used for mediator analyses. At 6 weeks, the intervention had significant effects on decisional balance, self-efficacy, and behavioral processes, but these effects were not maintained at 8 months. At 6 weeks, only decisional balance and behavioral processes were identified as mediators of motivational readiness outcomes. Results suggest that interventions of greater intensity and duration may be needed for sustained changes in mediators and motivational readiness for physical activity among older adults.
Wiedermann, Wolfgang; Li, Xintong; von Eye, Alexander
In a recent update of the standards for evidence in research on prevention interventions, the Society of Prevention Research emphasizes the importance of evaluating and testing the causal mechanism through which an intervention is expected to have an effect on an outcome. Mediation analysis is commonly applied to study such causal processes. However, these analytic tools are limited in their potential to fully understand the role of theorized mediators. For example, in a design where the treatment x is randomized and the mediator (m) and the outcome (y) are measured cross-sectionally, the causal direction of the hypothesized mediator-outcome relation is not uniquely identified. That is, both mediation models, x → m → y or x → y → m, may be plausible candidates to describe the underlying intervention theory. As a third explanation, unobserved confounders can still be responsible for the mediator-outcome association. The present study introduces principles of direction dependence which can be used to empirically evaluate these competing explanatory theories. We show that, under certain conditions, third higher moments of variables (i.e., skewness and co-skewness) can be used to uniquely identify the direction of a mediator-outcome relation. Significance procedures compatible with direction dependence are introduced and results of a simulation study are reported that demonstrate the performance of the tests. An empirical example is given for illustrative purposes and a software implementation of the proposed method is provided in SPSS.
Berry, Alessandra; Borgi, Marta; Terranova, Livia; Chiarotti, Flavia; Alleva, Enrico; Cirulli, Francesca
An ever increasing interest in the therapeutic aspects of the human-animal bond has led to a proliferation of animal-assisted interventions (AAI) involving dogs. However, most of these programs lack a solid methodological structure, and basic evaluative research is needed. The purpose of this study was to test the value of dog-assisted interventions as an innovative tool to increase quality of life in the geriatric population. Nineteen patients (men and women) with a mean age of 85 years participated in the study. Interactions between patients and visiting dogs occurred either in a social situation (socialization sessions) or in a therapeutic context (physical therapy sessions). We derived and characterized a specific ethogram of elderly-dog interactions aimed at evaluating the effectiveness of visiting dogs in improving mood, catalyzing social interactions and reducing their everyday apathetic state. Cortisol levels were also measured in the saliva, and depressive state was evaluated. Overall, results show a time-dependent increase in social behaviour and spontaneous interactions with the dogs. Dog-mediated interactions affected the daily increase in cortisol levels, thus having an 'activational effect', in contrast to the apathetic state of institutionalized elderly. Dog-mediated intervention programs appear to be promising tools to improve the social skills and enrich the daily activities of the institutionalized elderly. © 2012 The Authors. Psychogeriatrics © 2012 Japanese Psychogeriatric Society.
Barner, J.O.; Cunningham, M.E.; Freshley, M.D.; Lanning, D.D.
This is the final report of the High Burnup Effects Program (HBEP). It has been prepared to present a summary, with conclusions, of the HBEP. The HBEP was an international, group-sponsored research program managed by Battelle, Pacific Northwest Laboratories (BNW). The principal objective of the HBEP was to obtain well-characterized data related to fission gas release (FGR) for light water reactor (LWR) fuel irradiated to high burnup levels. The HBEP was organized into three tasks as follows: Task 1 -- high burnup effects evaluations; Task 2 -- fission gas sampling; and Task 3 -- parameter effects study. During the course of the HBEP, a program that extended over 10 years, 82 fuel rods from a variety of sources were characterized, irradiated, and then examined in detail after irradiation. The study of fission gas release at high burnup levels was the principal objective of the program and it may be concluded that no significant enhancement of fission gas release at high burnup levels was observed for the examined rods. The rim effect, an as yet unquantified contributor to athermal fission gas release, was concluded to be the one truly high-burnup effect. Though burnup enhancement of fission gas release was observed to be low, a full understanding of the rim region and rim effect has not yet emerged and this may be a potential area of further research. 25 refs., 23 figs., 4 tabs
Kaskutas, Lee Ann; Bond, Jason; Humphreys, Keith
This study tested the hypothesis that the relationship between Alcoholics Anonymous (AA) involvement and reduced substance use is partially explained (or 'mediated') by changes in social networks. This is a naturalistic longitudinal study of the course of alcohol problems. Study sites were the 10 largest public and private alcohol treatment programs in a northern California county. Three hundred and seventy-seven men and 277 women were recruited upon seeking treatment at study sites. At baseline and 1-year follow-up, we assessed alcohol consequences and dependence symptoms, consumption, social support for abstinence, pro-drinking social influences and AA involvement. In the structural equation model, AA involvement was a significant predictor of lower alcohol consumption and fewer related problems. The size of this effect decreased by 36% when network size and support for drinking were included as mediators. In logistic regression models predicting abstinence at follow-up, AA remained highly significant after including social network variables but was again reduced in magnitude. Thirty-day abstinence was predicted by AA involvement (OR=2.9), not having pro-drinking influences in one's network (OR=0.7) and having support for reducing consumption from people met in AA (versus no support; OR=3.4). In contrast, having support from non-AA members was not a significant predictor of abstinence. For alcohol-related outcomes other than abstinence, significant relationships were found for both AA-based and non-AA-based support. The type of social support specifically given by AA members, such as 24-hour availability, role modeling and experientially based advice for staying sober, may help to explain AA's mechanism of action. Results highlight the value of focusing on outcomes reflective of AA's goals (such as abstinence) when studying how AA works.
Siniscalchi, Michael J.; Jing, Jian; Weiss, Klaudiusz R.
Repetition priming is characterized by increased performance as a behavior is repeated. Although this phenomenon is ubiquitous, mediating mechanisms are poorly understood. We address this issue in a model system, the feeding network of Aplysia. This network generates both ingestive and egestive motor programs. Previous data suggest a chemical coding model: ingestive and egestive inputs to the feeding central pattern generator (CPG) release different modulators, which act via different second messengers to prime motor activity in different ways. The ingestive input to the CPG (neuron CBI-2) releases the peptides feeding circuit activating peptide and cerebral peptide 2, which produce an ingestive pattern of activity. The egestive input to the CPG (the esophageal nerve) releases the peptide small cardioactive peptide. This model is based on research that focused on a single aspect of motor control (radula opening). Here we ask whether repetition priming is observed if activity is triggered with a neuron within the core CPG itself and demonstrate that it is not. Moreover, previous studies demonstrated that effects of modulatory neurotransmitters that induce repetition priming persist. This suggests that it should be possible to “prime” motor programs triggered from within the CPG by first stimulating extrinsic modulatory inputs. We demonstrate that programs triggered after ingestive input activation are ingestive and programs triggered after egestive input activation are egestive. We ask where this priming occurs and demonstrate modifications within the CPG itself. This arrangement is likely to have important consequences for “task” switching, i.e., the cessation of one type of motor activity and the initiation of another. PMID:27466134
Full Text Available In this paper, we explore the way in which institutional contexts mediate values-focused behaviour change, with potential design implications. We use concepts taken from training research, where “learning transfer” refers to the translation into practice of the learning acquired during training: it is considered necessary to generalize it for the job context and for it to be maintained over a period of time on the job. In this paper, we analyse the example of one education for sustainable development (ESD intervention that is already established as pedagogically effective when it is deployed in diverse institutional environments worldwide—the Youth as Agents of Behaviour Change program of the International Federation of Red Cross and Red Crescent Societies (IFRC. This allows an opportunity to consider variations in learning transfer due to distinctive moderating institutional features, which can now be understood in terms of varying transfer climates, levels of leadership support and opportunities to practice. Additional barriers of tokenistic consultation, lack of role clarity and perverse effects of increased distance between trainees and their colleagues on return were also seen. ESD programs intending to bridge the values-action gap could benefit from not focusing only on the training content, but pre-planning organisational support for returning trainees and including in the training ways for them to assess and plan to overcome such difficulties.
Stefano eDel Duca
Full Text Available Research on polyamines in plants laps a long way of about 50 years and many roles have been discovered for these aliphatic cations. Polyamines regulate cell division, differentiation, organogenesis, reproduction, dormancy-break and senescence, homeostatic adjustments in response to external stimuli and stresses. Nevertheless, the molecular mechanisms of their multiple activities are still matter of research. Polyamines are present in free and bound forms and interact with several important cell molecules; some of these interactions may occur by covalent linkages catalyzed by transglutaminase, giving rise to ‘cationisation’ or cross-links among specific proteins. Senescence and PCD can be delayed by polyamines; in order to re-interpret some of these effects and to obtain new insights into their molecular mechanisms, their conjugation has been revised here. The transglutaminase-mediated interactions between proteins and polyamines are the main target of this review. After an introduction on the characteristics of this enzyme, on its catalysis and role in PCD in animals, the plant senescence and PCD models in which TGase has been studied, are presented: the corolla of naturally senescing or excised flowers, the leaves senescing, either excised or not, the pollen during self-incompatible pollination, the hypersensitive response and the tuber storage parenchyma during dormancy release. In all the models examined, transglutaminase appears to be involved by a similar molecular mechanism as described during apoptosis in animal cells, even though several substrates are different. Its effect is probably related to the type of PCD, but mostly to the substrate to be modified in order to achieve the specific PCD program. As a cross-linker of polyamines and proteins, transglutaminase is an important factor involved in multiple, sometimes controversial, roles of polyamines during senescence and PCD.
Wakamura, T; Akaike, H; Omori, Y; Niimi, Y; Takahashi, S; Fujimaki, A; Maekawa, S; Otani, Y
In some materials the competition between superconductivity and magnetism brings about a variety of unique phenomena such as the coexistence of superconductivity and magnetism in heavy-fermion superconductors or spin-triplet supercurrent in ferromagnetic Josephson junctions. Recent observations of spin-charge separation in a lateral spin valve with a superconductor evidence that these remarkable properties are applicable to spintronics, although there are still few works exploring this possibility. Here, we report the experimental observation of the quasiparticle-mediated spin Hall effect in a superconductor, NbN. This compound exhibits the inverse spin Hall (ISH) effect even below the superconducting transition temperature. Surprisingly, the ISH signal increases by more than 2,000 times compared with that in the normal state with a decrease of the injected spin current. The effect disappears when the distance between the voltage probes becomes larger than the charge imbalance length, corroborating that the huge ISH signals measured are mediated by quasiparticles.
Karimli, Leyla; Ssewamala, Fred M
This present study tests the proposition that an economic strengthening intervention for families caring for AIDS-orphaned adolescents would positively affect adolescent future orientation and psychosocial outcomes through increased asset accumulation (in this case, by increasing family savings). Using longitudinal data from the cluster-randomized experiment, we ran generalized estimating equation models with robust standard errors clustering on individual observations. To examine whether family savings mediate the effect of the intervention on adolescents' future orientation and psychosocial outcomes, analyses were conducted in three steps: (1) testing the effect of intervention on mediator; (2) testing the effect of mediator on outcomes, controlling for the intervention; and (3) testing the significance of mediating effect using Sobel-Goodman method. Asymmetric confidence intervals for mediated effect were obtained through bootstrapping-to address the assumption of normal distribution. Results indicate that participation in a matched Child Savings Account (CSA) program improved adolescents' future orientation and psychosocial outcomes by reducing hopelessness, enhancing self-concept, and improving adolescents' confidence about their educational plans. However, the positive intervention effect on adolescent future orientation and psychosocial outcomes was not transmitted through saving. In other words, participation in the matched CSA program improved adolescent future orientation and psychosocial outcomes regardless of its impact on reported savings. Further research is necessary to understand exactly how participation in economic strengthening interventions, for example, those that employ matched CSAs, shape adolescent future orientation and psychosocial outcomes: what, if not savings, transmits the treatment effect and how? Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
Cardoza, Deanna Janine
The purpose of this research study was to examine the effectiveness of training students in peer mediation (Mediator Mentors Curriculum), and how peer mediation-training influences third- through fifth-grade student perceptions of self-esteem, resiliency, and social competence. The research was a mixed-methods design with both quantitative and…
... 45 Public Welfare 2 2010-10-01 2010-10-01 false Mediation and fair hearings. 400.83 Section 400.83... Employment § 400.83 Mediation and fair hearings. (a) Mediation—(1) Public/private RCA program. The State must ensure that a mediation period prior to imposition of sanctions is provided to refugees by local...
Fix, Rebecca L; Alexander, Apryl A; Burkhart, Barry R
Depression, substance use, and impulsivity have been linked to family violence exposure and to the development of violent offending during adolescence. Additionally, the indirect effects associated with these factors may not generalize across different racial/ethnic adolescent populations. The present study tested whether race/ethnicity moderated the mediated relationship between family violence exposure and violent offending, with depression, substance use, and impulsivity as mediators. A sample of 1,359 male adolescents was obtained from a juvenile correctional program. Between-racial/ethnic group comparisons were generally consistent with previous findings. The overall moderated mediation model was significant in predicting violence for both racial/ethnic groups. Different factors influenced violent offending among African Americans and European Americans in the tested model. Furthermore, race/ethnicity moderated the relationship between family violence exposure and impulsivity and substance use. Implications and future directions resolving issues are discussed concerning whether race/ethnicity should be included as a moderator in models of violence.
Ambrose, Maureen L; Schminke, Marshall; Mayer, David M
Supervisors' perceptions of how fairly they are treated by their own supervisors can influence their subordinates' perceptions, attitudes, and behavior. We present a moderated mediation model that demonstrates how work group structure can enhance or constrain these effects. Results show supervisors' perceptions of the fairness of the interactional treatment they receive relate to their subordinates' perceptions of interactional justice climate, and this relationship is stronger in work groups with more organic structures. Furthermore, consistent with the moderated mediation prediction, interactional justice climate mediates the relationship between supervisors' perceptions of interactional justice and outcomes when work group structures are more organic. We discuss the implications of the findings for research on justice and trickle-down effects. PsycINFO Database Record (c) 2013 APA, all rights reserved.
Fairchild, Amanda J; McQuillin, Samuel D
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.
Kim, Chanmin; Daniels, Michael J; Marcus, Bess H; Roy, Jason A
We propose a Bayesian non-parametric (BNP) framework for estimating causal effects of mediation, the natural direct, and indirect, effects. The strategy is to do this in two parts. Part 1 is a flexible model (using BNP) for the observed data distribution. Part 2 is a set of uncheckable assumptions with sensitivity parameters that in conjunction with Part 1 allows identification and estimation of the causal parameters and allows for uncertainty about these assumptions via priors on the sensitivity parameters. For Part 1, we specify a Dirichlet process mixture of multivariate normals as a prior on the joint distribution of the outcome, mediator, and covariates. This approach allows us to obtain a (simple) closed form of each marginal distribution. For Part 2, we consider two sets of assumptions: (a) the standard sequential ignorability (Imai et al., 2010) and (b) weakened set of the conditional independence type assumptions introduced in Daniels et al. (2012) and propose sensitivity analyses for both. We use this approach to assess mediation in a physical activity promotion trial. © 2016, The International Biometric Society.
Bramsen, Rikke Holm; Lasgaard, Mathias; Koss, Mary P; Elklit, Ask; Banner, Jytte
The aim of the present study was to investigate the relationship between child maltreatment and severe early adolescent peer-on-peer sexual aggression, using a multiple mediator model. The study comprised 330 male Grade 9 students with a mean age of 14.9 years (SD=0.5). Estimates from the mediation model indicated significant indirect effects of child physical abuse on sexual aggression via peer influence and insecure-hostile masculinity. No significant total effect of child sexual abuse and child neglect on sexual aggression was found. Findings of the present study identify risk factors that are potentially changeable and therefore of value in informing the design of prevention programs aiming at early adolescent peer-on-peer sexual aggression in at-risk youth.
Huang, Jin; Oshima, Karen M Matta; Kim, Youngmi
Using two waves of data from the Child Development Supplement in the Panel Study of Income Dynamics, this study investigates whether parental characteristics (parenting stress, parental warmth, psychological distress, and parent's self-esteem) mediate household food insecurity's relations with child behavior problems. Fixed-effects analyses examine data from a low-income sample of 416 children from 249 households. This study finds that parenting stress mediates the effects of food insecurity on child behavior problems. However, two robustness tests produce different results from those of the fixed-effects models. This inconsistency suggests that household food insecurity's relations to the two types of child behavior problems need to be investigated further with a different methodology and other measures.
... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Mediation of term grazing... Lands § 251.103 Mediation of term grazing permit disputes. (a) Decisions subject to mediation. In those States with Department of Agriculture certified mediation programs, any holder of a term grazing permit...
Singh, Akanksha; Braun, Julia; Decker, Emilia; Hans, Sarah; Wagner, Agnes; Weisser, Wolfgang W; Zytynska, Sharon E
Interactions between aboveground and belowground terrestrial communities are often mediated by plants, with soil organisms interacting via the roots and aboveground organisms via the shoots and leaves. Many studies now show that plant genetics can drive changes in the structure of both above and belowground communities; however, the role of plant genetic variation in mediating aboveground-belowground interactions is still unclear. We used an earthworm-plant-aphid model system with two aphid species (Aphis fabae and Acyrthosiphon pisum) to test the effect of host-plant (Vicia faba) genetic variation on the indirect interaction between the belowground earthworms (Eisenia veneta) on the aboveground aphid populations. Our data shows that host-plant variety mediated an indirect ecological effect of earthworms on generalist black bean aphids (A. fabae), with earthworms increasing aphid growth rate in three plant varieties but decreasing it in another variety. We found no effect of earthworms on the second aphid species, the pea aphid (A. pisum), and no effect of competition between the aphid species. Plant biomass was increased when earthworms were present, and decreased when A. pisum was feeding on the plant (mediated by plant variety). Although A. fabae aphids were influenced by the plants and worms, they did not, in turn, alter plant biomass. Previous work has shown inconsistent effects of earthworms on aphids, but we suggest these differences could be explained by plant genetic variation and variation among aphid species. This study demonstrates that the outcome of belowground-aboveground interactions can be mediated by genetic variation in the host-plant, but depends on the identity of the species involved.
Coppens, Leonora C; Verkoeijen, Peter P J L; Bouwmeester, Samantha; Rikers, Remy M J P
The testing effect is the finding that information that is retrieved during learning is more often correctly retrieved on a final test than information that is restudied. According to the semantic mediator hypothesis the testing effect arises because retrieval practice of cue-target pairs (mother-child) activates semantically related mediators (father) more than restudying. Hence, the mediator-target (father-child) association should be stronger for retrieved than restudied pairs. Indeed, Carpenter (2011) found a larger testing effect when participants received mediators (father) than when they received target-related words (birth) as final test cues. The present study started as an attempt to test an alternative account of Carpenter's results. However, it turned into a series of conceptual (Experiment 1) and direct (Experiment 2 and 3) replications conducted with online samples. The results of these online replications were compared with those of similar existing laboratory experiments through small-scale meta-analyses. The results showed that (1) the magnitude of the raw mediator testing effect advantage is comparable for online and laboratory experiments, (2) in both online and laboratory experiments the magnitude of the raw mediator testing effect advantage is smaller than in Carpenter's original experiment, and (3) the testing effect for related cues varies considerably between online experiments. The variability in the testing effect for related cues in online experiments could point toward moderators of the related cue short-term testing effect. The raw mediator testing effect advantage is smaller than in Carpenter's original experiment.
Shen, Yu-Sheng; Lung, Shih-Chun Candice
Previous studies have shown both health and environmental benefits of green spaces, especially in moderating temperature and reducing air pollution. However, the characteristics of green structures have been overlooked in previous investigations. In addition, the mediation effects of green structures on respiratory mortality have not been assessed. This study explores the potential mediation pathways and effects of green structure characteristics on respiratory mortality through temperature, ...
Mujgan Bozkaya; Irem Erdem Aydin
In this study, perspectives of the first year students in the completely online Information Management Associate Degree Program at Anadolu University regarding computer as a communication medium were investigated. StudentsÕ perspectives on computer-mediated communications were analyzed in the light of three different views in the area of computer-mediated communications: The first view suggests that face-to-face settings are better communication environments compared to computer-mediated envi...
Hamada, Nobuyuki; Hara, Takamitsu; Kobayashi, Yasuhiko; Matsumoto, Hideki
A rapidly growing body of experimental evidence indicates that ionizing radiation induces biological effects in non-irradiated bystander cells that have received signals from adjacent or distant irradiated cells. This phenomenon, which has been termed the ionizing radiation-induced bystander effect, challenges the long-standing paradigm that radiation traversal through the nucleus of a cell is a prerequisite to elicit genetic damage or a biological response. Bystander effects have been observed in a number of experimental systems, and cells whose nucleus or cytoplasm is irradiated exert bystander responses. Bystander cells manifest a multitude of biological consequences, such as genetic and epigenetic changes, alterations in gene expression, activation of signal transduction pathways, and delayed effects in their progeny. Several mediating mechanisms have been proposed. These involve gap junction-mediated intercellular communication, secreted soluble factors, oxidative metabolism, plasma membrane-bound lipid rafts, and calcium fluxes. This paper reviews briefly the current knowledge of the bystander effect with a focus on proposed mechanisms. The potential benefit of bystander effects to cancer radiotherapy will also be discussed. (author)
Mortensen, Thomas Bøtker; Knudsen, Mette Præst
The purpose of this paper is to investigate whether collaborative experience can act as a mediating variable on the use of inter-organizational relationships on NPD performance. The paper tests two different research questions: 1) Is there a possible mediating effect of experience on the linkage...... between inter-organizational relationships and performance? And If yes: what is the nature of the mediating effect and the resulting influence on performance? The paper is motivated by the growing literature on the importance of inter-organizational relationships created by the idea that firms operate...
Overdijk, Marije B.; Jansen, J. H. Marco; Nederend, Maaike
RIIb as well as activating FcgRs induce DARA cross-linking-mediated PCD. In conclusion, our in vitro and in vivo data show that FcgRmediated cross-linking of DARA induces PCD of CD38-expressing multiple myeloma tumor cells, which potentially contributes to the depth of response observed in DARA......Emerging evidence suggests that FcgR-mediated cross-linking of tumor-bound mAbs may induce signaling in tumor cells that contributes to their therapeutic activity. In this study, we show that daratumumab (DARA), a therapeutic human CD38 mAb with a broad-spectrum killing activity, is able to induce...... programmed cell death (PCD) of CD38+ multiple myeloma tumor cell lines when cross-linked in vitro by secondary Abs or via an FcgR. By comparing DARA efficacy in a syngeneic in vivo tumor model using FcRg-chain knockout or NOTAM mice carrying a signaling-inactive FcRg-chain, we found that the inhibitory Fcg...
Wang, Zhixin; Ma, Caiyun; Han, Hongjuan; He, Runlian; Zhou, Liye; Liang, Ruifeng; Yu, Hongmei
Although there are many studies on the relationship between patient-related factors and negative caregiver outcomes, the specifics of this relationship are poorly understood. We aimed to examine whether caregiver social support moderated the relationship between patient factors and negative outcomes for caregivers of community-dwelling older adults with Alzheimer's disease (AD), and whether positive aspects of caregiving mediated this relationship. We conducted a cross-sectional study of patients diagnosed with AD from 2 hospitals and 3 communities in Taiyuan, China, and their caregivers. Latent moderated structural equations and the bias-corrected percentile bootstrap method were used to estimate the parameters of moderating and mediating effects, respectively. Social support significantly moderated the effects of AD patient cognitive function (P mediated the association between patient depression and caregiver burden (P = 0.006), caregiver anxiety (P = 0.007), and caregiver depression (P = 0.034). The findings identify social support as a moderator and positive aspects of caregiving as a mediator of the relationship between patient-related factors and negative caregiver outcomes. The results suggest that health care providers must offer more effective social support for caregivers. In addition, prompt identification of patient and caregiver emotional states could help to improve quality of life. Copyright © 2018 John Wiley & Sons, Ltd.
Murayama, Yoh; Ohba, Hiromi; Yasunaga, Masashi; Nonaka, Kumiko; Takeuchi, Rumi; Nishi, Mariko; Sakuma, Naoko; Uchida, Hayato; Shinkai, Shoji; Fujiwara, Yoshinori
The aim of this study was to clarify the effect of an intergenerational program on elderly persons' symptoms of depressive mood and in improving their sense of coherence, which is an element for successful coping with stressors. We evaluated an intervention research project (Research of Productivity by Intergenerational Sympathy [REPRINTS]), in which volunteers >65 years old read picture books to children in a school setting. The intervention group (REPRINTS) was recruited through intensive weekly training seminars for three months. The no-contact control group members were also recreated to participate in health checks and surveys for data collection purposes. Eventually, 26 participants in the intervention group and 54 in the control group were included for data analysis. The age or gender was not significantly different between the intervention and control groups. A two-way repeated-measures ANOVA shows a time × group significant interaction effects. Analyses of the simple main effects showed that sense of meaningfulness significantly increased for members of the intervention group at all terms, with no changes in the control group over time. Multiple mediation analysis revealed that participation in the intergenerational program was associated with a sense of manageability which was also significantly related to depressive mood. Intergenerational programs could serve as key health promoters among elderly people by decreasing the risk of social isolation and loneliness due to the greater sense of meaningfulness. However, given our limited sample size, generalizability was restricted and studies with larger cohorts are required to further validate our findings.
Ban, Jiyoon; Oh, Insoo
The current study examined the mediating effects of the teacher and peer relationships between parental abuse/neglect and a child's emotional/behavioral problems. A total of 2070 student surveys from the panel of the Korean Child Youth Panel Study (KCYPS) were analyzed by path analysis. The key findings of this study are outlined below. Firstly, parental physical and emotional abuse and neglect had significant effects on children's problems. The direct effect of parental abuse on emotional/behavioral problems was higher than the direct effect of parental neglect on emotional/behavioral problems. Secondly, the teacher relationship partially mediated the effects of the parental abuse/neglect on emotional/behavioral problems. Thirdly, the peer relationship also partially mediated the effects of parental abuse/neglect on children's emotional/behavioral problems. The indirect effect of parental neglect via teacher relationships and peer relationships was stronger than the indirect effect of parental abuse. This study is significant in that it identified that parental abuse/neglect was mediated by the teacher and peer relationship, thereby suggesting an implication for effective intervention with children who have suffered abuse and neglect. In terms of the teacher and peer relationship, understanding the influence of parental abuse and neglect on children's problems was discussed, and the limitations and recommendations for future study were suggested. Copyright © 2016 Elsevier Ltd. All rights reserved.
Fairchild, Amanda J.; McQuillin, Samuel D.
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
Weng, Xiaoqian; Li, Guangze; Li, Rongbao
This study examined the mediating role of working memory (WM) in the relation between rapid automatized naming (RAN) and Chinese reading comprehension. Three tasks assessing differentially visual and verbal components of WM were programmed by E-prime 2.0. Data collected from 55 Chinese college students were analyzed using correlations and hierarchical regression methods to determine the connection among RAN, reading comprehension, and WM components. Results showed that WM played a significant mediating role in the RAN-reading relation and that auditory WM made stronger contributions than visual WM. Taking into account of the multi-component nature of WM and the specificity of Chinese reading processing, this study discussed the mediating powers of the WM components, particularly auditory WM, further clarifying the possible components involved in the RAN-reading relation and thus providing some insight into the complicated Chinese reading process.
Full Text Available Background: The ubiquitous use of mobile phones provides an ideal opportunity to deliver interventions to increase physical activity levels. Understanding potential mediators of such interventions is needed to increase their effectiveness. A recent randomized controlled trial of a mobile phone and Internet (mHealth intervention was conducted in New Zealand to determine the effectiveness on exercise capacity and physical activity levels in addition to current cardiac rehabilitation (CR services for people (n=171 with ischaemic heart disease (IHD. Significant intervention effect was observed for self-reported leisure time physical activity and walking, but not peak oxygen uptake (PVO2 at 24 weeks. There was also significant improvement in self-efficacy.Objective: To evaluate the mediating effect of self-efficacy on physical activity levels in an mHealth delivered exercise CR programme. Methods: Treatment evaluations were performed on the principle of intention to treat (ITT. Adjusted regression analyses were conducted to evaluate the main treatment effect on leisure time physical activity and walking at 24 weeks, with and without change in self-efficacy as the mediator of interest. Results: Change in self-efficacy at 24 weeks significantly mediated the treatment effect on leisure time physical activity by 13%, but only partially mediated the effect on walking by 4% at 24 weeks. Conclusion: An mHealth intervention involving text messaging and Internet support had a positive treatment effect on leisure time physical activity and walking at 24 weeks, and this effect was likely mediated through changes in self-efficacy. Future trials should examine other potential mediators related to this type of intervention.
Reardon, Sean F.; Unlu, Fatih; Zhu, Pei; Bloom, Howard S.
We explore the use of instrumental variables (IV) analysis with a multisite randomized trial to estimate the effect of a mediating variable on an outcome in cases where it can be assumed that the observed mediator is the only mechanism linking treatment assignment to outcomes, an assumption known in the IV literature as the exclusion restriction.…
Yuan, Ying; MacKinnon, David P.
In this article, we propose Bayesian analysis of mediation effects. Compared with conventional frequentist mediation analysis, the Bayesian approach has several advantages. First, it allows researchers to incorporate prior information into the mediation analysis, thus potentially improving the efficiency of estimates. Second, under the Bayesian…
Sahoo, S.; Maharana, L.; Behera, B.R.
We study the effect of both Z and Z'-mediated flavor-changing neutral currents (FCNCs) on the B s → μ + μ - rare decay process. Mixing between ordinary and exotic left-handed quarks induces Z-mediated FCNC whereas mixing of right-handed ordinary and exotic quarks induces Z'-mediated FCNC. We find the branching ratio is enhanced from its standard model (SM) value due to the effect of both Z and Z'-mediated FCNCs. (author)
Kagey, Michael H.; Newman, Jamie J.; Bilodeau, Steve; Zhan, Ye; Orlando, David A.; van Berkum, Nynke L.; Ebmeier, Christopher C.; Goossens, Jesse; Rahl, Peter B.; Levine, Stuart S.; Taatjes, Dylan J.; Dekker, Job; Young, Richard A.
Summary Transcription factors control cell specific gene expression programs through interactions with diverse coactivators and the transcription apparatus. Gene activation may involve DNA loop formation between enhancer-bound transcription factors and the transcription apparatus at the core promoter, but this process is not well understood. We report here that Mediator and Cohesin physically and functionally connect the enhancers and core promoters of active genes in embryonic stem cells. Mediator, a transcriptional coactivator, forms a complex with Cohesin, which can form rings that connect two DNA segments. The Cohesin loading factor Nipbl is associated with Mediator/Cohesin complexes, providing a means to load Cohesin at promoters. DNA looping is observed between the enhancers and promoters occupied by Mediator and Cohesin. Mediator and Cohesin occupy different promoters in different cells, thus generating cell-type specific DNA loops linked to the gene expression program of each cell. PMID:20720539
Eustis, Ross; Tsang, Tsz Ming; Yang, Brigham; Scott, Daniel; Liaw, Bor Yann
A significant level of power generation from an abiotic, air breathing, mediated reducing sugar-air alkaline battery/fuel cell has been achieved in our laboratories at room temperature without complicated catalysis or membrane separation in the reaction chamber. Our prior studies suggested that mass transport limitation by the mediator is a limiting factor in power generation. New and effective mediators were sought here to improve charge transfer and power density. Forty-five redox dyes were studied to identify if any can facilitate mass transport in alkaline electrolyte solution; namely, by increasing the solubility and mobility of the dye, and the valence charge carried per molecule. Indigo dyes were studied more closely to understand the complexity involved in mass transport. The viability of water-miscible co-solvents was also explored to understand their effect on solubility and mass transport of the dyes. Using a 2.0 mL solution, 20% methanol by volume, with 100 mM indigo carmine, 1.0 M glucose and 2.5 M sodium hydroxide, the glucose-air alkaline battery/fuel cell attained 8 mA cm-2 at short-circuit and 800 μW cm-2 at the maximum power point. This work shall aid future optimization of mediated charge transfer mechanism in batteries or fuel cells.
Kasten, Stefanie; van Osch, Liesbeth; Eggers, Sander Matthijs; de Vries, Hein
Sufficient fruit consumption is beneficial for a healthy live. While many Dutch adults intent to eat the recommended amount of fruit, only 5-10% of the population actually adheres to the recommendation. One mechanism that can help to narrow this gap between intention and actual fruit consumption is action planning. However, action planning is only assumed to be effective if plans are enacted. This study assessed which action plans are made and enacted, and further aimed to investigate two main hypotheses: 1. the effect of action planning (at T1) on fruit consumption (at T2) is mediated by plan enactment (at T3); 2. positive intentions (2a), high self-efficacy (2b) and a strong habit to eat fruit (2c) enhance the mediation of plan enactment, whereas a strong habit to eat snacks (2d) hinders the mediation of plan enactment. This study was a self-reported longitudinal online survey study. A total of 428 participants filled in a survey, measuring demographic factors (e.g. gender, age, education level), several socio-cognitive constructs (i.e. attitudes, self-efficacy, habit, action planning, plan enactment), and fruit consumption, at three points in time (baseline, after 1 month, and after 3 months). Mediation and moderated mediation analyses were used to investigate the planning-plan enactment- fruit consumption relationship. Up to 70% of the participants reported to have enacted their T1 action plans at T2. Action planning on fruit consumption was fully mediated by plan enactment (Hypothesis 1). All four proposed moderators (i.e. intention, self-efficacy, habit to consume fruit, and habit to consume snacks) significantly influenced the mediation (Hypotheses 2a-2d). Mediation of plan enactment was only present with high levels of intention, high levels of self-efficacy, strong habits to eat fruit, and weak habits to eat snacks. The study suggests the importance of plan enactment for fruit consumption. Furthermore, it emphasizes the necessity of facilitating factors
Shen, Yu-Sheng; Lung, Shih-Chun Candice
Previous studies have shown both health and environmental benefits of green spaces, especially in moderating temperature and reducing air pollution. However, the characteristics of green structures have been overlooked in previous investigations. In addition, the mediation effects of green structures on respiratory mortality have not been assessed. This study explores the potential mediation pathways and effects of green structure characteristics on respiratory mortality through temperature, primary and secondary air pollutants separately using partial least squares model with data from Taiwan. The measurable characteristics of green structure include the largest patch percentage, landscape proportion, aggregation, patch distance, and fragmentation. The results showed that mortality of pneumonia and chronic lower respiratory diseases could be reduced by minimizing fragmentation and increasing the largest patch percentage of green structure, and the mediation effects are mostly through reducing air pollutants rather than temperature. Moreover, a high proportion of but fragmented green spaces would increase secondary air pollutants and enhance health risks; demonstrating the deficiency of traditional greening policy with primary focus on coverage ratio. This is the first research focusing on mediation effects of green structure characteristics on respiratory mortality, revealing that appropriate green structure planning can be a useful complementary strategy in environmental health management.
Probst, Thomas; Dinkel, Andreas; Schmid-Mühlbauer, Gabriele; Radziej, Katharina; Limburg, Karina; Pieh, Christoph; Lahmann, Claas
Vertigo symptoms can lead to more or less vertigo-related handicap. This longitudinal study investigated whether depression, anxiety, and/or somatization mediate the relationship between vertigo symptoms and vertigo-related handicap. N=111 patients with vertigo/dizziness provided complete data on the following measures: Vertigo symptoms at baseline, depression at 6-month follow-up, anxiety at 6-month follow-up, somatization at 6-month follow-up, and vertigo handicap at 12-month follow-up. Mediation analyses with bootstrapping were performed to investigate the mediating role of anxiety, depression, and somatization in the relationship between vertigo symptoms and vertigo-related handicap. When the mediating role of anxiety, depression, and somatization was evaluated separately from each other in single mediation models, the effect vertigo symptoms at baseline exerted on vertigo-related handicap at 12-month follow-up was significantly mediated by depression at 6-month follow-up (pvertigo symptoms at baseline on vertigo-related handicap at 12-month follow-up (pvertigo symptoms lead to vertigo-related handicap. Copyright © 2016 Elsevier Inc. All rights reserved.
Hitlan, Robert Thomas; A Zárate, Michael; Kelly, Kristine M; Catherine DeSoto, M
This research investigated the effects of linguistic ostracism, defined as any communication setting in which a target individual (or group) is ostracized by another individual (or group) in a language that the target has extremely limited ability to understand. Participants were included or ostracized by their group members during a computer-mediated group discussion. Half of the ostracized participants were linguistically ostracized via their group members conversing with one another in a language the participant did not know well (Spanish Ostracism: SO), or in a language the participant did know well (English Ostracism: EO). SO participants reported feeling less similar than both included and EO participants. SO participants also reported being angrier and expressed more prejudice than included participants (and EO participants using effect size estimates). Results also provided support for the hypothesized serial mediation model. Findings are discussed in terms of implications for intergroup relations.
Lo, Herman H M; Ng, Siu Man; Chan, Cecilia L W; Lam, K F; Lau, Bobo H P
Previous studies have identified different, but highly correlated variables explaining the effects of mindfulness training. Many of them are limited by tautological explanation. Under the framework of the mind-body connection, mindfulness training cultivates body awareness and promotes self-management of illness. Stagnation, a concept from Chinese medicine, may help explain the mechanism of change in mindfulness training. Individuals with depressive and anxiety symptoms (n=82) were randomized to either a Compassion-Mindfulness Therapy (C-MT) program or a waitlist control condition. The effect of stagnation as a mediator was investigated for dependent variables including depression, anxiety, and other physical and mental health variables. Depression, anxiety, stagnation, physical distress, daily functioning, positive affect, negative affect. Compared with the participants in the control group, those who completed C-MT demonstrated significant decreases in depression, F(1, 78)=15.67, p<.001, anxiety, F(1, 78)=7.72, p<.001, stagnation, F(1, 78)=4.96, p<.001, and other body-mind-spirit well-being measures. After entering the change in stagnation as the mediator, the effect of treatment reduced: depression (.35-.22), anxiety (.33-.05), and same patterns in other three secondary measures. The Sobel test was administered and significant reductions between group and depression (z=2.18, p=.029), anxiety (z=2.21, p=.027), and three secondary other measures (p<.05) were indicated. The study provides initial support for the role of stagnation in mediating changes in mindfulness training. It adds evidence to body-mind nondualism and offers new possibilities in studying treatment process and change mechanism. Copyright © 2013 Elsevier Ltd. All rights reserved.
Full Text Available Priscila Corraini,1 Morten Olsen,1 Lars Pedersen,1 Olaf M Dekkers,1,2 Jan P Vandenbroucke1–3 1Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark; 2Leiden University Medical Center, Leiden, the Netherlands; 3Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK Abstract: We revisited the three interrelated epidemiological concepts of effect modification, interaction and mediation for clinical investigators and examined their applicability when using research databases. The standard methods that are available to assess interaction, effect modification and mediation are explained and exemplified. For each concept, we first give a simple “best-case” example from a randomized controlled trial, followed by a structurally similar example from an observational study using research databases. Our explanation of the examples is based on recent theoretical developments and insights in the context of large health care databases. Terminology is sometimes ambiguous for what constitutes effect modification and interaction. The strong assumptions underlying the assessment of interaction, and particularly mediation, require clinicians and epidemiologists to take extra care when conducting observational studies in the context of health care databases. These strong assumptions may limit the applicability of interaction and mediation assessments, at least until the biases and limitations of these assessments when using large research databases are clarified. Keywords: methods, epidemiology, effect modifiers, stratified analyses, health care administrative claims
Yuan, Ying; MacKinnon, David P.
This article proposes Bayesian analysis of mediation effects. Compared to conventional frequentist mediation analysis, the Bayesian approach has several advantages. First, it allows researchers to incorporate prior information into the mediation analysis, thus potentially improving the efficiency of estimates. Second, under the Bayesian mediation analysis, inference is straightforward and exact, which makes it appealing for studies with small samples. Third, the Bayesian approach is conceptua...
Barry W Alto
Full Text Available Predators may affect prey population growth and community diversity through density mediated lethal and trait mediated non-lethal effects that influence phenotypic traits of prey. We tested experimentally the roles of thinning the density of prey (lethality in the absence of predator cues and density and trait mediated effects (lethality + intimidation of predatory midge Corethrella appendiculata on competing native and invasive mosquito prey. Predator-mediated reductions in prey and density reductions in the absence of C. appendiculata resulted in lower percent survivorship to adulthood and estimates of the finite rate of increase (λ' for invasive mosquito Aedes albopictus relative to that of controls. In most instances, thinning the density of prey in the absence, but not in the presence, of C. appendiculata cues resulted in lower survivorship to adulthood and λ' for native mosquito Aedes triseriatus relative to that of controls. Together, these results suggested trait mediated effects of C. appendiculata specific to each species of mosquito prey. Release from intraspecific competition attributable to density reductions in the absence, but not in the presence, of C. appendiculata enhanced growth and lengthened adult lifespan relative to that of controls for A. albopictus but not A. triseriatus. These results show the importance of predator-mediated density and trait mediated effects on phenotypic traits and populations of invasive and native mosquitoes. Species-specific differences in the phenotypic responses of prey may be due, in part, to longer evolutionary history of C. appendiculata with A. triseriatus than A. albopictus.
Consortium for Appropriate Dispute Resolution in Special Education (CADRE), Eugene, OR.
This brief paper, in Spanish, discusses the use of mediation as a method for resolving disagreements between schools or early intervention programs and parents of children with disabilities. It identifies benefits of mediation such as maintenance of an ongoing and positive relationship between the school and family, simple resolution of conflicts…
Ganz, Jennifer B; Heath, Amy K; Lund, Emily M; Camargo, Siglia P H; Rispoli, Mandy J; Boles, Margot; Plaisance, Lauren
Although research has investigated the impact of peer-mediated interventions and visual scripts on social and communication skills in children with autism spectrum disorders, no studies to date have investigated peer-mediated implementation of scripts. This study investigated the effects of peer-implemented scripts on a middle school student with autism, intellectual impairments, and speech-language impairment via a multiple baseline single-case research design across behaviors. The target student demonstrated improvements in three communicative behaviors when implemented by a trained peer; however, behaviors did not generalize to use with an untrained typically developing peer.
CANTALEANO, KAREN RAPHAELE; RODRIGUES, GRAZIELA PERRETTO; MARTINS, TOMAS SPARANO
ABSTRACT Purpose: The purpose of this article is to verify the mediating effect of a proactive market orientation capability in the relationship between entrepreneurial orientation (EO) and service innovation in micro and small companies in the food-away from home sector. We analyzed the mediating effect of a marketing capability (proactive market capability) because, according to Morgan et al. (2009), a capability is an ability developed from a strategic orientation, and capabilities and or...
Gao, Tingting; Xiang, Yu-Tao; Zhang, Han; Zhang, Zhao; Mei, Songli
The purposes of this study were to investigate the mediating effect of smartphone addiction and depression on neuroticism and quality of life. Self-reported measures of neuroticism, smart-phone addiction, depression, and quality of life were administered to 722 Chinese university students. Results showed smartphone addiction and depression were both significantly affected neuroticism and quality of life. The direct effect of neuroticism on quality of life was significant, and the chain-mediating effect of smartphone addiction and depression was also significant. In conclusion, neuroticism, smartphone addiction, and depression are important variables that worsen quality of life. Copyright © 2017 Elsevier B.V. All rights reserved.
Yamada, Ann-Marie; Lee, Karen K; Dinh, Tam Q; Barrio, Concepción; Brekke, John S
This study investigated intrinsic motivation as a mediator of the relationship between clinical symptoms and functioning. The mediation model was tested with a sample of 166 adults with schizophrenia spectrum disorders attending psychosocial rehabilitation programs in a diverse urban community. Ethnic minority status was examined as a moderator of the mediation model. Motivation was measured using items reflecting intrapsychic drive. Symptoms were assessed with the expanded Brief Psychiatric Rating Scale and functioning with the Role Functioning Scale. Motivation was a significant mediator of the relationship between functioning and all symptom scores; fully mediating the relationship between functioning and negative, disorganized, and global symptoms, and partially mediating the relationship between positive symptoms and functioning. Motivation scores between ethnic minority and nonminority individuals differed significantly (p moderation effect was indicated. The strong mediation effect schizophrenia of motivation on the symptoms-functioning relationship supports future work to translate findings into effective recovery-oriented services.
Ng, Kok-Yee; Ang, Soon; Chan, Kim-Yin
The trait theory of leadership is advanced by a joint investigation of the mediating role of (a) leadership self-efficacy (LSE = leader's perceived capabilities to perform leader roles) in linking neuroticism, extraversion, and conscientiousness with leader effectiveness and (b) the moderating role of job demands and job autonomy in influencing the mediation. Using K. J. Preacher, D. D. Rucker, and A. F. Hayes' (2007) moderated mediation framework, the authors tested the model (over a 2-year period) with matched data from 394 military leaders and their supervisors. Results showed that LSE mediated the relationships for neuroticism, extraversion, and conscientiousness with leader effectiveness. Moderated mediation analyses further revealed that LSE mediated the relationships for (a) all 3 personality variables for only those leaders with low job demands; (b) neuroticism and conscientiousness for only those leaders with high job autonomy; and (c) extraversion, regardless of a leader's level of job autonomy. Results underscore the importance of accounting for leaders' situational contexts when examining the relationships between personality, LSE, and effectiveness.
Rikke Holm Bramsen
Full Text Available Objective: The aim of the present study was to investigate the relationship between child maltreatment and severe early adolescent peer-on-peer sexual aggression, using a multiple mediator model. Methods: The study comprised 330 male Grade 9 students with a mean age of 14.9 years (SD=0.5. Results: Estimates from the mediation model indicated significant indirect effects of child physical abuse on sexual aggression via peer influence and insecure-hostile masculinity. No significant total effect of child sexual abuse and child neglect on sexual aggression was found. Conclusions: Findings of the present study identify risk factors that are potentially changeable and therefore of value in informing the design of prevention programs aiming at early adolescent peer-on-peer sexual aggression in at-risk youth.
Bühler, Anneke; Schröder, Elke; Silbereisen, Rainer K
Research has shown that life skills programs are the most effective single activity in school-based substance abuse prevention. However, little is known about the processes through which they are effective. This study examines whether an evidence-based prevention program targeting general competence is effective through the promotion of knowledge about life skills and enhanced related behaviors. Based on a sample of 442 fifth graders participating in a quasi-experimental prevention study, as expected, mediation analyses revealed that increased knowledge about life skills paralleled an increase in students' distant attitudes toward alcohol and nicotine use. Unexpectedly, behaviors manifesting enhanced life skills were found not only among program participants who remained experimental/non-smokers or stopped smoking but also among smokers. In general, findings suggest that favorable prevention outcomes may be influenced through building knowledge about general life skills. The notion of uniform mechanisms of effectiveness in prevention programs is discussed.
β3-adrenoceptor mediates β3-selective agonist-induced effects on energy expenditure, insulin secrtion and food ... Journal of the Ghana Science Association ... is usually associated with obesity, also involves defective energy expenditure, ...
Full Text Available Abstract Background Conducting process evaluations of health promoting interventions, and measuring the effectiveness of specific intervention components, may help in the understanding of program failure or success. The purposes of the present study were to examine adults' exposure to and involvement in specific components of a three year long pseudo-experimental community-based physical activity intervention, and to examine the relationship between such exposure and participation and changes in stages of change in physical activity and psychosocial mediators. Methods 1497 persons in the intervention group attended the baseline survey in 2000 (50.6% and 1204 (80.4 of baseline attendees provided data on the outcome variables of the present study. In 2003, 1089 were still living in the area, and were re-invited to follow-up assessments. Current analyses are based on the 603 persons (mean age 49 ± 10 years who provided baseline and follow-up data for the current purposes (56.6% follow-up rate. Process data, stages of change in physical activity, and potential psychosocial mediators of change in physical activity were assessed by questionnaires. The theory-based intervention was composed of communication, physical activity, environmental and participatory components. Data were analysed using frequency and descriptive statistics, Chi-square and t-tests, and regression analyses. Results Exposure and participation rates in the various intervention components varied greatly (1.5–92.7%. Participation in walking groups and aerobic exercise groups, as well as having seen the "Walk the stairs"-poster were significantly and positively related to change in stages of change in physical activity (β = .12, p = .011; β = .211, p Conclusion Findings revealed that particular intervention components, such as participation in physical activity groups, were more strongly related to forward transition in stages of change in physical activity than others. These
Carpenter, Shana K.
Previous research has proposed that tests enhance retention more than do restudy opportunities because they promote the effectiveness of mediating information--that is, a word or concept that links a cue to a target (Pyc & Rawson, 2010). Although testing has been shown to promote retention of mediating information that participants were asked…
Mancini, Anthony D; Prati, Gabriele; Black, Sarah
Although research has confirmed that violent losses can exacerbate grief reactions, few investigations have explored underlying mechanisms. In this study, the authors used a dataset on bereaved spouses and bereaved parents at 4- and 18-months postloss to examine the mediating effects of self-worth and worldviews (benevolence and meaningfulness beliefs). Persons bereaved by violent causes had significantly more posttraumatic stress disorder (PTSD), grief, and depression symptoms at 4- and 18-months postloss than persons bereaved by natural causes. Moreover, self-worth but not worldviews mediated the effects of violent loss on PTSD and depression symptoms cross sectionally and PTSD symptoms longitudinally. Findings underscore that self-views are a critical component of problematic reactions to violent loss, but fail to support the role of "shattered" worldviews. Copyright © 2011 International Society for Traumatic Stress Studies.
Wykes, Til; Reeder, Clare; Huddy, Vyv; Taylor, Rumina; Wood, Helen; Ghirasim, Natalia; Kontis, Dimitrios; Landau, Sabine
Background Cognitive remediation (CRT) affects functioning but the extent and type of cognitive improvements necessary are unknown. Aim To develop and test models of how cognitive improvement transfers to work behaviour using the data from a current service. Method Participants (N49) with a support worker and a paid or voluntary job were offered CRT in a Phase 2 single group design with three assessments: baseline, post therapy and follow-up. Working memory, cognitive flexibility, planning and work outcomes were assessed. Results Three models were tested (mediation — cognitive improvements drive functioning improvement; moderation — post treatment cognitive level affects the impact of CRT on functioning; moderated mediation — cognition drives functioning improvements only after a certain level is achieved). There was evidence of mediation (planning improvement associated with improved work quality). There was no evidence that cognitive flexibility (total Wisconsin Card Sorting Test errors) and working memory (Wechsler Adult Intelligence Scale III digit span) mediated work functioning despite significant effects. There was some evidence of moderated mediation for planning improvement if participants had poorer memory and/or made fewer WCST errors. The total CRT effect on work quality was d = 0.55, but the indirect (planning-mediated CRT effect) was d = 0.082 Conclusion Planning improvements led to better work quality but only accounted for a small proportion of the total effect on work outcome. Other specific and non-specific effects of CRT and the work programme are likely to account for some of the remaining effect. This is the first time complex models have been tested and future Phase 3 studies need to further test mediation and moderated mediation models. PMID:22503640
Zhou, Ji; Urhahne, Detlef
Based on Weiner's attributional theory of intrapersonal motivation, the mediating effect of attributions between teacher judgment and student motivation was examined. In two studies, 144 German and 272 Chinese fourth-grade elementary school students were tested on their mathematical achievement, causal ascriptions for success and failure,…
Park, Wall Yun; Yoon, Sook Hee
This study was a secondary analysis to verify the mediating role of organizational citizenship behavior (OCB) between organizational justice (OJ) and organizational effectiveness (OE) in nursing organizations. The RN-BSNs and their colleagues in Seoul and Busan were subjects. The data was collected for 20 days between September 13 and October 2, 2004. Two hundred eighty three data sets were used for the final analysis. The fitness of models were tested using AMOS 5. The fitness of hypothetical model was moderate. Procedural Justice (PJ), Interaction Justice (IJ) and Distributive Justice (DJ) had direct effects on Job Satisfaction (JS), Organizational Commitment (OC) and Turnover Intention (TI) in OE, and indirect effects on JS, OC and TI mediated by OCB. The modified model improved with ideal fitness showed the causal relations among OE. In modified model, PJ, IJ and DJ had direct positive effects on OCB and JS and OC in OE, and indirect effects on JS and OC mediated by OCB. JS and OC in OE had a direct negative effect on TI. OCB mediated the relationship between OJ and OE, so the nursing managers should enhance OCB of the nurses in order to improve OE.
Weman-Josefsson, Karin; Lindwall, Magnus; Ivarsson, Andreas
Based on the Self-determination theory process model, this study aimed to explore relationships between the latent constructs of psychological need satisfaction, autonomous motivation and exercise behaviour; the mediational role of autonomous motivation in the association of psychological need satisfaction with exercise behaviour; as well as gender and age differences in the aforementioned associations. Adult active members of an Internet-based exercise program (n = 1091) between 18 and 78 years of age completed a test battery on motivational aspects based on Self-determination theory. The Basic Psychological Needs in Exercise Scale and the Behavioural Regulation in Exercise Questionnaire-2 were used to measure need satisfaction and type of motivation and the Leisure Time Exercise Questionnaire to measure self-reported exercise. Need satisfaction predicted autonomous motivation, which in turn predicted exercise, especially for women. Autonomous motivation was found to mediate the association between need satisfaction and exercise. Age and gender moderated several of the paths in the model linking need satisfaction with motivation and exercise. The results demonstrated gender and age differences in the proposed sequential mechanisms between autonomous motivation and exercise in the process model. This study thus highlights a potential value in considering moderating factors and the need to further examine the underlying mechanisms between needs, autonomous motivation, and exercise behaviour.
Fairchild, Amanda J.; McQuillin, Samuel D.
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…
Wodtke, Geoffrey T; Parbst, Matthew
Although evidence indicates that neighborhoods affect educational outcomes, relatively little research has explored the mechanisms thought to mediate these effects. This study investigates whether school poverty mediates the effect of neighborhood context on academic achievement. Specifically, it uses longitudinal data from the Panel Study of Income Dynamics, counterfactual methods, and a value-added modeling strategy to estimate the total, natural direct, and natural indirect effects of exposure to an advantaged rather than disadvantaged neighborhood on reading and mathematics abilities during childhood and adolescence. Contrary to expectations, results indicate that school poverty is not a significant mediator of neighborhood effects during either developmental period. Although moving from a disadvantaged neighborhood to an advantaged neighborhood is estimated to substantially reduce subsequent exposure to school poverty and improve academic achievement, school poverty does not play an important mediating role because even the large differences in school composition linked to differences in neighborhood context appear to have no appreciable effect on achievement. An extensive battery of sensitivity analyses indicates that these results are highly robust to unobserved confounding, alternative model specifications, alternative measures of school context, and measurement error, which suggests that neighborhood effects on academic achievement are largely due to mediating factors unrelated to school poverty.
Minderman, J; Lind, J; Cresswell, W
The effect of competition for a limiting resource on the population dynamics of competitors is usually assumed to operate directly through starvation, yet may also affect survival indirectly through behaviourally mediated effects that affect risk of predation. Thus, competition can affect more than
Yan Bingsheng; Li Lihua; Sun Hongtao
This article explored the effect of instrumental interaction and relational interaction on consumer engagement (community engagement and brand engagement) among community members. The mediating effect of E-social capital was investigated as well. The research results showed that: both instrumental interaction and interpersonal interaction promote the formation of E-social capital (online trust and online reciprocity); online trust plays a partial mediating role between community interaction (...
Han, Sangsook; Kim, Ohsook; Joo, Yunsu; Choi, Eunduck; Han, Jeongwon
The purpose of this study was to investigate the casual relationship between nurses' mentoring and turnover intention and to verify the goodness of fit between a hypothetical model and actual data in order to suggest an adequate model. The survey was conducted with 434 nurses working in general hospitals in Seoul. Data were collected during February 2013, and analyzed with SPSS Windows 18.0 and AMOS 7.0. Mentoring was found to have a direct effect on decrease in role stress. Role stress had a direct effect on increase in burnout and mentoring, with role stress as a mediator, there was an indirect effect on burnout. Burnout had a direct effect on increase in turnover intention, and role stress, with burnout as a mediator, and mentoring, through role stress and burnout, an indirect effect was found on increase in turnover intention. The results of this study indicate that nursing managers should put effort into reducing role stress and burnout, while seeking to establish a more efficient mentoring system so that for nurses, there will be a lowering of turnover intention.
Williams, Kirk R; Stansfield, Richard
To manage intimate partner violence (IPV), the criminal justice system has turned to risk assessment instruments to predict if a perpetrator will reoffend. Empirically determining whether offenders assessed as high risk are those who recidivate is critical for establishing the predictive validity of IPV risk assessment instruments and for guiding the supervision of perpetrators. But by focusing solely on the relation between calculated risk scores and subsequent IPV recidivism, previous studies of the predictive validity of risk assessment instruments omitted mediating factors intended to mitigate the risk of this behavioral recidivism. The purpose of this study was to examine the mediating effects of such factors and the moderating effects of risk assessment on the relation between assessed risk (using the Domestic Violence Screening Instrument-Revised [DVSI-R]) and recidivistic IPV. Using a sample of 2,520 perpetrators of IPV, results revealed that time sentenced to jail and time sentenced to probation each significantly mediated the relation between DVSI-R risk level and frequency of reoffending. The results also revealed that assessed risk moderated the relation between these mediating factors and IPV recidivism, with reduced recidivism (negative estimated effects) for high-risk perpetrators but increased recidivism (positive estimate effects) for low-risk perpetrators. The implication is to assign interventions to the level of risk so that no harm is done. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Gao, Meng; Li, Yu-Chen; Zhang, Wei
To examine the mediating effect of self-concept between interparental conflict and mental health in children and adolescents. A total of 689 students (10-18 years) were surveyed using the convenient sampling method, and their mental health, self-concept, and interparental conflict were examined by the general status questionnaire, Strengths and Difficulties Questionnaire, Self-Description Questionnaire, and Children's Perception of Interparental Conflict Scale. Structural equation modeling (SEM) and simultaneous analysis of several groups were used to construct the mediator model and analyze the data, respectively. The Bootstrap method was used to assess the significance of the mediating effects. Interparental conflict was positively correlated with mental health of children and adolescents (Pself-concept (PSelf-concept was negatively correlated with mental health (PSelf-concept had a partial (60%) mediating effect between interparental conflict and mental health. Academic stage, but not gender, had a regulatory role on interparental conflict, mental health, and self-concept. Self-concept plays an important role between interparental conflict and mental health. It is necessary to improve self-concept level in children and adolescents exposed to interparental conflict.
Loeys, Tom; Talloen, Wouter; Goubert, Liesbet; Moerkerke, Beatrijs; Vansteelandt, Stijn
It is well known from the mediation analysis literature that the identification of direct and indirect effects relies on strong no unmeasured confounding assumptions of no unmeasured confounding. Even in randomized studies the mediator may still be correlated with unobserved prognostic variables that affect the outcome, in which case the mediator's role in the causal process may not be inferred without bias. In the behavioural and social science literature very little attention has been given so far to the causal assumptions required for moderated mediation analysis. In this paper we focus on the index for moderated mediation, which measures by how much the mediated effect is larger or smaller for varying levels of the moderator. We show that in linear models this index can be estimated without bias in the presence of unmeasured common causes of the moderator, mediator and outcome under certain conditions. Importantly, one can thus use the test for moderated mediation to support evidence for mediation under less stringent confounding conditions. We illustrate our findings with data from a randomized experiment assessing the impact of being primed with social deception upon observer responses to others' pain, and from an observational study of individuals who ended a romantic relationship assessing the effect of attachment anxiety during the relationship on mental distress 2 years after the break-up. © 2016 The British Psychological Society.
Vivas, María; Zas, Rafael; Sampedro, Luis; Solla, Alejandro
The resistance to abiotic stress is increasingly recognised as being impacted by maternal effects, given that environmental conditions experienced by parent (mother) trees affect stress tolerance in offspring. We hypothesised that abiotic environmental maternal effects may also mediate the resistance of trees to biotic stress. The influence of maternal environment and maternal genotype and the interaction of these two factors on early resistance of Pinus pinaster half-sibs to the Fusarium circinatum pathogen was studied using 10 mother genotypes clonally replicated in two contrasting environments. Necrosis length of infected seedlings was 16% shorter in seedlings grown from favourable maternal environment seeds than in seedlings grown from unfavourable maternal environment seeds. Damage caused by F. circinatum was mediated by maternal environment and maternal genotype, but not by seed mass. Mechanisms unrelated to seed provisioning, perhaps of epigenetic nature, were probably involved in the transgenerational plasticity of P. pinaster, mediating its resistance to biotic stress. Our findings suggest that the transgenerational resistance of pines due to an abiotic stress may interact with the defensive response of pines to a biotic stress. PMID:23922944
Full Text Available The resistance to abiotic stress is increasingly recognised as being impacted by maternal effects, given that environmental conditions experienced by parent (mother trees affect stress tolerance in offspring. We hypothesised that abiotic environmental maternal effects may also mediate the resistance of trees to biotic stress. The influence of maternal environment and maternal genotype and the interaction of these two factors on early resistance of Pinus pinaster half-sibs to the Fusarium circinatum pathogen was studied using 10 mother genotypes clonally replicated in two contrasting environments. Necrosis length of infected seedlings was 16% shorter in seedlings grown from favourable maternal environment seeds than in seedlings grown from unfavourable maternal environment seeds. Damage caused by F. circinatum was mediated by maternal environment and maternal genotype, but not by seed mass. Mechanisms unrelated to seed provisioning, perhaps of epigenetic nature, were probably involved in the transgenerational plasticity of P. pinaster, mediating its resistance to biotic stress. Our findings suggest that the transgenerational resistance of pines due to an abiotic stress may interact with the defensive response of pines to a biotic stress.
Xu, Shuai; Wang, Jufang; Ding, Nan; Hu, Wentao; Zhang, Xurui; Wang, Bing; Hua, Junrui; Wei, Wenjun; Zhu, Qiyun
Bystander effects can be induced through cellular communication between irradiated cells and non-irradiated cells. The signals that mediate this cellular communication, such as cytokines, reactive oxygen species, nitric oxide and even microRNAs, can be transferred between cells via gap junctions or extracellular medium. We have previously reported that miR-21, a well described DDR (DNA damage response) microRNA, is involved in radiation-induced bystander effects through a medium-mediated way. However, the mechanisms of the microRNA transfer have not been elucidated in details. In the present study, it was found that exosomes isolated from irradiated conditioned medium could induce bystander effects. Furthermore, we demonstrated plenty of evidences that miR-21, which is up-regulated as a result of mimic transfection or irradiation, can be transferred from donor or irradiated cells into extracellular medium and subsequently get access to the recipient or bystander cells through exosomes to induce bystander effects. Inhibiting the miR-21 expression in advance can offset the bystander effects to some extent. From all of these results, it can be concluded that the exosome-mediated microRNA transfer plays an important role in the radiation-induced bystander effects. These findings provide new insights into the functions of microRNAs and the cellular communication between the directly irradiated cells and the non-irradiated cells.
Christensen, Sara Sletten; Frostholm, Lisbeth; Ørnbøl, Eva
Objective 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....... Methods 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...
Kelsey, J E; Belluzzi, J D
Brief electrical stimulation of the enkephalin-rich globus pallidus at 1-h intervals produced kindled, clonic seizures in rats as rapidly as similar stimulation of the amygdala. Massing the kindling trials at 10-min intervals inhibited the occurrence of subsequent seizures, especially following globus pallidus stimulation. Naloxone (20 mg/kg), an opiate receptor antagonist, reversed this post-ictal inhibition of seizures following massed trials, but had no effect on seizures kindled at 1-h intervals. Thus, endorphin-released during seizures do not appear to mediate the production of kindled seizures, but do appear to mediate the transient posts ictal inhibition of seizures.
Zapata-Martín del Campo, Carlos Manuel; Martínez-Rosas, Martín
Corticotrophin releasing factor, vasopressin, oxytocin, natriuretic hormones, angiotensin, neuregulins, some purinergic substances, and some cytokines contribute to the long-term modulation and restructuring of cardiovascular regulation networks and, at the same time, have relevance in situations of comorbid abnormal stress responses. The synthesis, release, and receptor expression of these mediators seem to be under epigenetic control since early stages of life, possibly underlying the comorbidity to coronary artery disease (CAD) and stress-related disorders (SRD). The exposure to environmental conditions, such as stress, during critical periods in early life may cause epigenetic programming modifying the development of pathways that lead to stable and long-lasting alterations in the functioning of these mediators during adulthood, determining the risk of or resilience to CAD and SRD. However, in contrast to genetic information, epigenetic marks may be dynamically altered throughout the lifespan. Therefore, epigenetics may be reprogrammed if the individual accepts the challenge to undertake changes in their lifestyle. Alternatively, epigenetics may remain fixed and/or even be inherited in the next generation. In this paper, we analyze some of the common neuroendocrine functions of these mediators in CAD and SRD and summarize the evidence indicating that they are under early programming to put forward the theoretical hypothesis that the comorbidity of these diseases might be epigenetically programmed and modified over the lifespan of the individual. PMID:29670001
Carlos Manuel Zapata-Martín del Campo
Full Text Available Corticotrophin releasing factor, vasopressin, oxytocin, natriuretic hormones, angiotensin, neuregulins, some purinergic substances, and some cytokines contribute to the long-term modulation and restructuring of cardiovascular regulation networks and, at the same time, have relevance in situations of comorbid abnormal stress responses. The synthesis, release, and receptor expression of these mediators seem to be under epigenetic control since early stages of life, possibly underlying the comorbidity to coronary artery disease (CAD and stress-related disorders (SRD. The exposure to environmental conditions, such as stress, during critical periods in early life may cause epigenetic programming modifying the development of pathways that lead to stable and long-lasting alterations in the functioning of these mediators during adulthood, determining the risk of or resilience to CAD and SRD. However, in contrast to genetic information, epigenetic marks may be dynamically altered throughout the lifespan. Therefore, epigenetics may be reprogrammed if the individual accepts the challenge to undertake changes in their lifestyle. Alternatively, epigenetics may remain fixed and/or even be inherited in the next generation. In this paper, we analyze some of the common neuroendocrine functions of these mediators in CAD and SRD and summarize the evidence indicating that they are under early programming to put forward the theoretical hypothesis that the comorbidity of these diseases might be epigenetically programmed and modified over the lifespan of the individual.
Zapata-Martín Del Campo, Carlos Manuel; Martínez-Rosas, Martín; Guarner-Lans, Verónica
Corticotrophin releasing factor, vasopressin, oxytocin, natriuretic hormones, angiotensin, neuregulins, some purinergic substances, and some cytokines contribute to the long-term modulation and restructuring of cardiovascular regulation networks and, at the same time, have relevance in situations of comorbid abnormal stress responses. The synthesis, release, and receptor expression of these mediators seem to be under epigenetic control since early stages of life, possibly underlying the comorbidity to coronary artery disease (CAD) and stress-related disorders (SRD). The exposure to environmental conditions, such as stress, during critical periods in early life may cause epigenetic programming modifying the development of pathways that lead to stable and long-lasting alterations in the functioning of these mediators during adulthood, determining the risk of or resilience to CAD and SRD. However, in contrast to genetic information, epigenetic marks may be dynamically altered throughout the lifespan. Therefore, epigenetics may be reprogrammed if the individual accepts the challenge to undertake changes in their lifestyle. Alternatively, epigenetics may remain fixed and/or even be inherited in the next generation. In this paper, we analyze some of the common neuroendocrine functions of these mediators in CAD and SRD and summarize the evidence indicating that they are under early programming to put forward the theoretical hypothesis that the comorbidity of these diseases might be epigenetically programmed and modified over the lifespan of the individual.
Brody, Gene H; Chen, Yi-Fu; Kogan, Steven M; Murry, Velma McBride; Brown, Anita C
This report extends earlier accounts by addressing the effects of the Strong African American Families (SAAF) program across 65 months. Two hypotheses were tested: (a) Rural African American youths randomly assigned to participate in SAAF would demonstrate lower rates of alcohol use than would control youths more than 5 years later, and (b) SAAF's effects on deterring the onset of alcohol use in early adolescence would carry forward to mediate the program's long-term effects. African American youths in rural Georgia (mean age at pretest = 10.8 years) were assigned randomly to the SAAF group (n = 369) or to a control group (n = 298). Past-month alcohol use was assessed at pretest and at 9, 18, 29, 53, and 65 months after pretest. SAAF participants increased their alcohol use at a slower rate than did adolescents in the control condition across the follow-up assessments. At the 65-month assessment, SAAF participants reported having drunk alcohol half as often as did youths in the control group. Consistent with the second hypothesis, SAAF's effects on deterring initiation carried forward to account for its effects on alcohol use across time. Training in protective parenting processes and self-regulatory skills during preadolescence may contribute to a self-sustaining trajectory of disinterest in and avoidance of alcohol use during adolescence when peers begin to model and sanction it. (c) 2010 APA, all rights reserved
Atlas, Lauren Y; Lindquist, Martin A; Bolger, Niall; Wager, Tor D
Recent human neuroimaging studies have investigated the neural correlates of either noxious stimulus intensity or reported pain. Although useful, analyzing brain relationships with stimulus intensity and behavior separately does not address how sensation and pain are linked in the central nervous system. In this study, we used multi-level mediation analysis to identify brain mediators of pain--regions in which trial-by-trial responses to heat explained variability in the relationship between noxious stimulus intensity (across 4 levels) and pain. This approach has the potential to identify multiple circuits with complementary roles in pain genesis. Brain mediators of noxious heat effects on pain included targets of ascending nociceptive pathways (anterior cingulate, insula, SII, and medial thalamus) and also prefrontal and subcortical regions not associated with nociceptive pathways per se. Cluster analysis revealed that mediators were grouped into several distinct functional networks, including the following: somatosensory, paralimbic, and striatal-cerebellar networks that increased with stimulus intensity; and 2 networks co-localized with "default mode" regions in which stimulus intensity-related decreases mediated increased pain. We also identified "thermosensory" regions that responded to increasing noxious heat but did not predict pain reports. Finally, several regions did not respond to noxious input, but their activity predicted pain; these included ventromedial prefrontal cortex, dorsolateral prefrontal cortex, cerebellar regions, and supplementary motor cortices. These regions likely underlie both nociceptive and non-nociceptive processes that contribute to pain, such as attention and decision-making processes. Overall, these results elucidate how multiple distinct brain systems jointly contribute to the central generation of pain. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
GUCEL, Cem; TOKMAK, Ismail; TURGUT, Hakan
The aim of this study is to examine the effects of locus of control on organizational citizenship behaviors and the mediating effect of the perceived organizational support. For this aim, firstly, the locus of control, then organizational citizenship behaviors and, finally, the mediating effect of the perceived organizational support are explained. In the application part, a questionnaire including the measures of the locus of control, organizational support and organizational citizenship beh...
Kühne, R.J.; Weber, P.; Sommer, K.
A new stream of research indicates that framing effects are based on emotional as well as cognitive processes. However, it is not entirely clear whether emotions mediate framing effects and what the moderators of emotional mediation processes are. To address these questions, we conducted an
Inauen, Jennifer; Stocker, Andrea; Scholz, Urte
Coping planning, the formation of plans to overcome behavioral barriers is assumed to promote health behavior maintenance, but the literature on this is inconsistent. In this study, we aimed to investigate the mechanisms of a coping planning intervention that adversely affected maintained safe water consumption. We also explored perceived behavioral difficulty as a potential moderator of coping planning interventions. In the second phase of a cluster-randomised trial, households (N = 177 analyzed) were randomly allocated to a coping planning intervention or a comparison group (repetition of interventions from first intervention phase). Safe water consumption, the mechanisms of coping planning, and perceived difficulty were measured pre-post. The data were analyzed using mediation and moderated mediation analysis. Changes in behavioral intention mediated the intervention effects on behavioral maintenance (b = -0.36, 95% CI [-0.91, -0.03]). Changes in perceived coping planning (b = 0.08, 95% CI [-0.12, 0.34]), and maintenance self-efficacy (b = -0.13, 95% CI [-0.45, 0.01]) did not mediate the effects. Prior perceived difficulty moderated the coping planning intervention effects on maintenance via intention. Coping planning may decrease motivation for health behavior maintenance for persons who experienced few barriers prior to the planning intervention. © 2018 The International Association of Applied Psychology.
Li, Ming; And Others
Reports a study that examined the characteristics that enable graduate sport management programs to achieve their objectives. Surveys of sport management educators found they agreed on 11 characteristics that indicated a sport management program's effectiveness. Respondents believed an effective program should produce sport managers, not…
Full Text Available Objective: To explore the effect of hydromorphone hydrochloride combined with ropivacaine for PCEA after orthopedic surgery on the synthesis of pain mediators, inflammatory mediator and oxygen free radicals. Methods: A total of 120 patients with fracture who underwent operation in the hospital between July 2014 and December 2016 were collected and divided into control group and observation group according to the random number table method, 60 cases in each group. Control group received morphine hydrochloride combined with ropivacaine for analgesia, observation group received hydromorphone hydrochloride combined with ropivacaine for analgesia, and the postoperative analgesia lasted for 48 h. The differences in serum levels of pain mediators, inflammatory mediators and oxidative stress indexes were compared between the two groups. Results: Immediately after operation, the differences in serum levels of pain mediators, inflammatory mediators and oxidative stress indexes were not statistically significant between the two groups. 48 h after operation, serum PGE2, SP, β-EP, IL-6, MCP-1, HMGB-1 and MDA levels of both groups of patients were significantly lower than those immediately after operation while Cu-Zn SOD and GSH-Px levels were significantly higher than those immediately after operation, and serum PGE2, SP, β-EP, IL-6, MCP-1, HMGB-1 and MDA levels of observation group were significantly lower than those of control group while Cu-Zn SOD and GSH-Px levels were significantly higher than those of control group. Conclusion: Hydromorphone hydrochloride combined with ropivacaine for PCEA after orthopedic surgery is effective in alleviating pain and inhibiting systemic inflammatory response.
Liu, Jianghong; Raine, Adrian
Early malnutritional status has been associated with reduced cognitive ability in childhood. However, there are almost no studies on the effect of malnutrition on positive social behavior, and no tests of possible mediating mechanisms. This study tests the hypothesis that poor nutritional status is associated with impaired social functioning in childhood, and that neurocognitive ability mediates this relationship. We assessed 1553 male and female 3-year-olds from a birth cohort on measures of malnutrition, social behavior and verbal and spatial neurocognitive functions. Children with indicators of malnutrition showed impaired social behavior (p malnutrition and degree of social behavior, with increased malnutrition associated with more impaired social behavior. Neurocognitive ability was found to mediate the nutrition–social behavior relationship. The mediation effect of neurocognitive functioning suggests that poor nutrition negatively impacts brain areas that play important roles in developing positive social behavior. Findings suggest that reducing poor nutrition, alternatively promoting good nutrition, may help promote positive social behavior in early childhood during a critical period for social and neurocognitive development, with implications for improving positive health in adulthood. PMID:27133006
Coane, Jennifer H.; Huff, Mark J.; Hutchison, Keith A.
Younger and older adults studied lists of words directly (e.g., creek, water) or indirectly (e.g., beaver, faucet) related to a nonpresented critical lure (CL; e.g., river). Indirect (i.e., mediated) lists presented items that were only related to CLs through nonpresented mediators (i.e., directly related items). Following study, participants completed a condition-specific task, math, a recall test with or without a warning about the CL, or tried to guess the CL. On a final recognition test, warnings (vs. math and recall without warning) decreased false recognition for direct lists, and guessing increased mediated false recognition (an ironic effect of guessing) in both age groups. The observed age-invariance of the ironic effect of guessing suggests that processes involved in mediated false memory are preserved in aging and confirms the effect is largely due to activation in semantic networks during encoding and to the strengthening of these networks during the interpolated tasks. PMID:26393390
Guay, Frédéric; Ratelle, Catherine; Roy, Amélie; Litalien, David
Three conceptual models were tested to examine the relationships among academic self-concept, autonomous academic motivation, and academic achievement. This allowed us to determine whether 1) autonomous academic motivation mediates the relation between academic self-concept and achievement, 2) academic self-concept mediates the relation between autonomous academic motivation and achievement, or 3) both motivational constructs have an additive effect on academic achievement. A total of 925 hig...
Jan B. Rosen
Full Text Available Moral decision making involves affective and cognitive functions like emotional empathy, reasoning and cognitive empathy/theory of mind (ToM, which are discussed to be subject to age-related alterations. Additionally, sex differences in moral decision making have been reported. However, age-related changes in moral decision making from early to late adulthood and their relation to sex and neuropsychological functions have not been studied yet.One hundred ninety seven participants (122 female, aged 19 to 86 years, were tested with a moral decision making task comprising forced choice everyday life situations in which an altruistic option that favors a socially accepted alternative had to be considered against an egoistic option that favors personal benefit over social interests. The percentage of altruistic decisions was analyzed. A structural equation model (SEM was calculated to test the hypothesis whether age and sex predict altruistic moral decision, and whether relevant neuropsychological domains mediate these hypothesized relationships.A significant relationship between age and moral decision making was found indicating more frequent altruistic decisions with increasing age. Furthermore, women decided more altruistically than men. The SEM showed that both age and sex are significant predictors of altruistic moral decision making, mediated by emotional empathy but not by reasoning. No cognitive empathy and ToM scores were correlated to age and moral decision-making at the same time and thus were not included in the SEM.Our data suggest that increasing age and female sex have an effect on altruistic moral decisions, but that this effect is fully mediated by emotional empathy. The fact that changes of moral decision making with age are mediated by emotional empathy can be interpreted in the light of the so-called positivity effect and increasing avoidance of negative affect in aging. The mediated sex effect might represent both biological
Rosen, Jan B; Brand, Matthias; Kalbe, Elke
Moral decision making involves affective and cognitive functions like emotional empathy, reasoning and cognitive empathy/theory of mind (ToM), which are discussed to be subject to age-related alterations. Additionally, sex differences in moral decision making have been reported. However, age-related changes in moral decision making from early to late adulthood and their relation to sex and neuropsychological functions have not been studied yet. One hundred ninety seven participants (122 female), aged 19-86 years, were tested with a moral decision making task comprising forced choice "everyday life" situations in which an altruistic option that favors a socially accepted alternative had to be considered against an egoistic option that favors personal benefit over social interests. The percentage of altruistic decisions was analyzed. A structural equation model (SEM) was calculated to test the hypothesis whether age and sex predict altruistic moral decision, and whether relevant neuropsychological domains mediate these hypothesized relationships. A significant relationship between age and moral decision making was found indicating more frequent altruistic decisions with increasing age. Furthermore, women decided more altruistically than men. The SEM showed that both age and sex are significant predictors of altruistic moral decision making, mediated by emotional empathy but not by reasoning. No cognitive empathy and ToM scores were correlated to age and moral decision making at the same time and thus were not included in the SEM. Our data suggest that increasing age and female sex have an effect on altruistic moral decisions, but that this effect is fully mediated by emotional empathy. The fact that changes of moral decision making with age are mediated by emotional empathy can be interpreted in the light of the so-called "positivity effect" and increasing avoidance of negative affect in aging. The mediated sex effect might represent both biological aspects and
Bein, Edward; Deutsch, Jonah; Hong, Guanglei; Porter, Kristin E; Qin, Xu; Yang, Cheng
This study investigates appropriate estimation of estimator variability in the context of causal mediation analysis that employs propensity score-based weighting. Such an analysis decomposes the total effect of a treatment on the outcome into an indirect effect transmitted through a focal mediator and a direct effect bypassing the mediator. Ratio-of-mediator-probability weighting estimates these causal effects by adjusting for the confounding impact of a large number of pretreatment covariates through propensity score-based weighting. In step 1, a propensity score model is estimated. In step 2, the causal effects of interest are estimated using weights derived from the prior step's regression coefficient estimates. Statistical inferences obtained from this 2-step estimation procedure are potentially problematic if the estimated standard errors of the causal effect estimates do not reflect the sampling uncertainty in the estimation of the weights. This study extends to ratio-of-mediator-probability weighting analysis a solution to the 2-step estimation problem by stacking the score functions from both steps. We derive the asymptotic variance-covariance matrix for the indirect effect and direct effect 2-step estimators, provide simulation results, and illustrate with an application study. Our simulation results indicate that the sampling uncertainty in the estimated weights should not be ignored. The standard error estimation using the stacking procedure offers a viable alternative to bootstrap standard error estimation. We discuss broad implications of this approach for causal analysis involving propensity score-based weighting. Copyright © 2018 John Wiley & Sons, Ltd.
Reardon, Sean F.; Unlu, Faith; Zhu, Pei; Bloom, Howard
We explore the use of instrumental variables (IV) analysis with a multi-site randomized trial to estimate the effect of a mediating variable on an outcome in cases where it can be assumed that the observed mediator is the only mechanism linking treatment assignment to outcomes, as assumption known in the instrumental variables literature as the…
... 32 National Defense 5 2010-07-01 2010-07-01 false Mediation. 776.38 Section 776.38 National... Professional Conduct § 776.38 Mediation. (a) Mediation: (1) A covered attorney may act as a mediator between... mediation, including the advantages and risks involved, and the effect on the attorney-client...
Murphy, Edel; Dooley, Barbara; Menton, Aoife; Dolphin, Louise
The primary aim of this study was to investigate whether the relationship between global self-worth and weight concerns and global self-worth and shape concerns was mediated by pertinent body image factors, while controlling for gender and estimated BMI. Participants were 775 adolescents (56% male) aged 12-18years (M=14.6; SD=1.50). Mediation analysis revealed a direct and a mediated effect between global self-worth and two body image models: 1) weight concerns and 2) shape concerns. The strongest mediators in both models were physical appearance, restrained eating, and depression. Partial mediation was observed for both models, indicating that body image factors which span cognitive, affective, and behavioral constructs, explain the association between global self-worth and weight and shape concerns. Implications for future research, weight and shape concern prevention and global self-worth enhancement programs are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.
Wang, Y W; Liu, G Z; Zhou, X T; Sheng, P J; Cui, F F; Shi, T
Objective: To investigate the interaction between mental elasticityand occupational stress and depressionin female nurses and the mediating effect of mental elasticity, as well as the functioning way of mental elasticity in occupational stress-depression. Methods: From August to October, 2015, cluster sampling was used to select 122 female nurses in a county-level medical institution as study subjects. The Connor-Davidson Resilience Scale (CD-RISC) , Occupational Stress Inventory-Revised Edition (OSI-R) , and Self-Rating Depression Scale (SDS) were used to collect the data on mental elasticity, occupational stress, and depression and analyze their correlation and mediating effect. Results: The 122 female nurses had a mean mental elasticity score of 62.4±15.1, which was significantly lower than the Chinese norm (65.4±13.9) ( P occupational stress and depression ( r =-0.559 and -0.559, both P Occupational stress and the two subscales mental stress reaction and physical stress reaction were positively correlated with depression ( r =0.774, 0.734, and 0.725, all P occupational stress had a positive predictive effect on depression ( β =0.744, P occupational stress on depression and a significant mediating effect of mental elasticity ( a =-0.527, b =-0.227, c =0.744, c '=0.627; all P occupational stress and depression and can alleviate the adverse effect of occupational stress and reduce the development of depression.
Evans, Shirley F; Beebe, Maureen; Mahmood, Maryam; Janthachotikun, Sawanya; Eldoumi, Heba; Peterson, Sandra; Payton, Mark; Perkins-Veazie, Penelope; Smith, Brenda J; Lucas, Edralin A
This pilot study examined the effects of freeze-dried mango (Mangifera indica L.) supplementation on anthropometric measurements, lipid parameters, and inflammatory mediators in obese individuals. A total of 20 obese (body mass index [BMI]: 30-35 kg/m2) adults (11 men and 9 women), aged 20 to 50 years, received 10 g/d of ground freeze-dried mango pulp for 12 weeks. Anthropometrics, lipids, and inflammatory mediators were assessed at baseline and after 12 weeks of mango supplementation. There were no differences between baseline and final visits in inflammatory mediators, lipids, diet, physical activity, and anthropometrics. Relationships were present at baseline and final visits between adiponectin and high-density lipoprotein cholesterol and between leptin and fat mass. Correlations were found after 12 weeks of mango supplementation between leptin and the following variables: waist-to-height ratio, BMI, percent fat, and fat mass. Our findings demonstrate that 12-week consumption of freeze-dried mango by obese individuals has no impact on obesity-related inflammation. PMID:28983188
Liu, Feng-Chuan; Cheng, Kai-Lin; Chao, Minston; Tseng, Hsu-Min
This paper aims to provide empirical evidence concerning the impact of team climate on knowledge sharing behavior and the mediating effects of individuals' altruistic intentions in the context of healthcare settings. Questionnaire data were collected from 212 administrators employed at a medical center in Taiwan. Team climate was assessed by the Team Climate Inventory composed of four factors, participative safety, support for innovation, vision, and task orientation. The proposed hypotheses were tested using structural equation modeling. The influence of the team innovation climate on knowledge sharing behavior was evident. Furthermore, individuals' altruistic intentions played a full mediating role in the relationship between team innovation climate and knowledge sharing behavior. These results contribute to the field of the people-orientated perspective in knowledge management. The full mediating effect of employees' altruistic intentions provides healthcare team managers the direction to accelerate knowledge sharing behavior.
Lu, Ethel Regis
Mediating Global Filipinos: The Filipino Channel and the Filipino Diaspora examines the notion of the "global Filipino" as imagined and constructed vis-à-vis television programs on The Filipino Channel (TFC). This study contends that transnational Philippine media broadly construct the notion of "global Filipinos" as diverse, productive, multicultural citizens, which in effect establishes a unified overseas Filipino citizenry for Philippine economic welfare and global cultural capital. Desp...
Fairchild, Amanda J.; McQuillin, Samuel D.
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 pr...
MacKinnon, David P; Coxe, Stefany; Baraldi, Amanda N
Business theories often specify the mediating mechanisms by which a predictor variable affects an outcome variable. In the last 30 years, investigations of mediating processes have become more widespread with corresponding developments in statistical methods to conduct these tests. The purpose of this article is to provide guidelines for mediation studies by focusing on decisions made prior to the research study that affect the clarity of conclusions from a mediation study, the statistical models for mediation analysis, and methods to improve interpretation of mediation results after the research study. Throughout this article, the importance of a program of experimental and observational research for investigating mediating mechanisms is emphasized.
Wu, Wei; Carroll, Ian A; Chen, Po-Yi
Cross-lagged panel models (CLPMs) are widely used to test mediation with longitudinal panel data. One major limitation of the CLPMs is that the model effects are assumed to be fixed across individuals. This assumption is likely to be violated (i.e., the model effects are random across individuals) in practice. When this happens, the CLPMs can potentially yield biased parameter estimates and misleading statistical inferences. This article proposes a model named a random-effects cross-lagged panel model (RE-CLPM) to account for random effects in CLPMs. Simulation studies show that the RE-CLPM outperforms the CLPM in recovering the mean indirect and direct effects in a longitudinal mediation analysis when random effects exist in the population. The performance of the RE-CLPM is robust to a certain degree, even when the random effects are not normally distributed. In addition, the RE-CLPM does not produce harmful results when the model effects are in fact fixed in the population. Implications of the simulation studies and potential directions for future research are discussed.
VanderWeele, Tyler J.; Hong, Guanglei; Jones, Stephanie M.; Brown, Joshua L.
Peer influence and social interactions can give rise to spillover effects in which the exposure of one individual may affect outcomes of other individuals. Even if the intervention under study occurs at the group or cluster level as in group-randomized trials, spillover effects can occur when the mediator of interest is measured at a lower level than the treatment. Evaluators who choose groups rather than individuals as experimental units in a randomized trial often anticipate that the desirable changes in targeted social behaviors will be reinforced through interference among individuals in a group exposed to the same treatment. In an empirical evaluation of the effect of a school-wide intervention on reducing individual students’ depressive symptoms, schools in matched pairs were randomly assigned to the 4Rs intervention or the control condition. Class quality was hypothesized as an important mediator assessed at the classroom level. We reason that the quality of one classroom may affect outcomes of children in another classroom because children interact not simply with their classmates but also with those from other classes in the hallways or on the playground. In investigating the role of class quality as a mediator, failure to account for such spillover effects of one classroom on the outcomes of children in other classrooms can potentially result in bias and problems with interpretation. Using a counterfactual conceptualization of direct, indirect and spillover effects, we provide a framework that can accommodate issues of mediation and spillover effects in group randomized trials. We show that the total effect can be decomposed into a natural direct effect, a within-classroom mediated effect and a spillover mediated effect. We give identification conditions for each of the causal effects of interest and provide results on the consequences of ignoring “interference” or “spillover effects” when they are in fact present. Our modeling approach
Kresin, V.Z.; Wolf, S.A.; Deutscher, G.
The theoretical model capable of calculating the superconducting properties (e.g. Tc, energy gaps, etc) of materials such as Y 1 Ba 2 Cu 3 O 7 which consist of two conducting subsystem (planes and chains) is developed. The system is characterized by two energies gaps. The interplay of two channels (phonon-mediated processes and the intrinsic proximity effect) inducing the superconducting state in the chains is studied. The proximity effect combined with the phonon-mediated channel appears to be favorable for superconductivity. The theory describes the effect of the oxygen ordering on Tc and the induced gap and allows us to explain a number of experiments including the plateau in Tc versus oxygen, the large residual microwave losses, zero-bias anomalies and the temperature dependence of the penetration depth. (orig.)
Yuan, Ying; MacKinnon, David P.
Mediation analysis has many applications in psychology and the social sciences. The most prevalent methods typically assume that the error distribution is normal and homoscedastic. However, this assumption may rarely be met in practice, which can affect the validity of the mediation analysis. To address this problem, we propose robust mediation analysis based on median regression. Our approach is robust to various departures from the assumption of homoscedasticity and normality, including heavy-tailed, skewed, contaminated, and heteroscedastic distributions. Simulation studies show that under these circumstances, the proposed method is more efficient and powerful than standard mediation analysis. We further extend the proposed robust method to multilevel mediation analysis, and demonstrate through simulation studies that the new approach outperforms the standard multilevel mediation analysis. We illustrate the proposed method using data from a program designed to increase reemployment and enhance mental health of job seekers. PMID:24079925
Luby, Joan; Belden, Andy; Botteron, Kelly; Marrus, Natasha; Harms, Michael P; Babb, Casey; Nishino, Tomoyuki; Barch, Deanna
IMPORTANCE The study provides novel data to inform the mechanisms by which poverty negatively impacts childhood brain development. OBJECTIVE To investigate whether the income-to-needs ratio experienced in early childhood impacts brain development at school age and to explore the mediators of this effect. DESIGN, SETTING, AND PARTICIPANTS This study was conducted at an academic research unit at the Washington University School of Medicine in St Louis. Data from a prospective longitudinal study of emotion development in preschool children who participated in neuroimaging at school age were used to investigate the effects of poverty on brain development. Children were assessed annually for 3 to 6 years prior to the time of a magnetic resonance imaging scan, during which they were evaluated on psychosocial, behavioral, and other developmental dimensions. Preschoolers included in the study were 3 to 6 years of age and were recruited from primary care and day care sites in the St Louis metropolitan area; they were annually assessed behaviorally for 5 to 10 years. Healthy preschoolers and those with clinical symptoms of depression participated in neuroimaging at school age/early adolescence. EXPOSURE Household poverty as measured by the income-to-needs ratio. MAIN OUTCOMES AND MEASURES Brain volumes of children's white matter and cortical gray matter, as well as hippocampus and amygdala volumes, obtained using magnetic resonance imaging. Mediators of interest were caregiver support/hostility measured observationally during the preschool period and stressful life events measured prospectively. RESULTS Poverty was associated with smaller white and cortical gray matter and hippocampal and amygdala volumes. The effects of poverty on hippocampal volume were mediated by caregiving support/hostility on the left and right, as well as stressful life events on the left. CONCLUSIONS AND RELEVANCE The finding that exposure to poverty in early childhood materially impacts brain
Shi, Rui; Zhang, Shilei; Xu, Hang; Liu, Xufeng; Miao, Danmin
This correlation study investigated the relationship between nurses' regulatory focus and burnout, as mediated by their perceptions of transformational leadership, using a cross-sectional research design with anonymous questionnaires. In July-August 2012, data were collected from 378 nurses from three hospitals in Shaanxi Province, China, using self-report questionnaires for measuring the nurses' regulatory focus, their level of burnout and their perception of whether the leadership of their supervisor was transformational. Structural equation modelling and bootstrapping procedures were used to identify the mediating effect of their perceptions of transformational leadership. The results supported our hypothesized model. The type of regulatory focus emerged as a significant predictor of burnout. Having a perception of transformational leadership partially mediated the relationship between regulatory focus and burnout. Having a promotion focus reduced burnout when the participants perceived transformational leadership, whereas having a prevention focus exhibited the opposite pattern. The mediating effect of the perception of transformational leadership suggests that a promotion focus may help diminish burnout, directly and indirectly. Nurse managers must be aware of the role of a regulatory focus and cultivate promotion focus in their followers. © 2014 Wiley Publishing Asia Pty Ltd.
Full Text Available Cognitive self-regulation can strongly modulate pain and emotion. However, it is unclear whether self-regulation primarily influences primary nociceptive and affective processes or evaluative ones. In this study, participants engaged in self-regulation to increase or decrease pain while experiencing multiple levels of painful heat during functional magnetic resonance imaging (fMRI imaging. Both heat intensity and self-regulation strongly influenced reported pain, but they did so via two distinct brain pathways. The effects of stimulus intensity were mediated by the neurologic pain signature (NPS, an a priori distributed brain network shown to predict physical pain with over 90% sensitivity and specificity across four studies. Self-regulation did not influence NPS responses; instead, its effects were mediated through functional connections between the nucleus accumbens and ventromedial prefrontal cortex. This pathway was unresponsive to noxious input, and has been broadly implicated in valuation, emotional appraisal, and functional outcomes in pain and other types of affective processes. These findings provide evidence that pain reports are associated with two dissociable functional systems: nociceptive/affective aspects mediated by the NPS, and evaluative/functional aspects mediated by a fronto-striatal system.
..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM Administrative Compliance § 205.663 Mediation. Any dispute with respect to denial of certification or proposed suspension or revocation of certification under this part may...
Brouillet, Sophie; Hoffmann, Pascale; Benharouga, Mohamed; Salomon, Aude; Schaal, Jean-Patrick; Feige, Jean-Jacques; Alfaidy, Nadia
Endocrine gland derived vascular endothelial growth factor (EG-VEGF) also called prokineticin (PK1), has been identified and linked to several biological processes including angiogenesis. EG-VEGF is abundantly expressed in the highest vascularized organ, the human placenta. Here we characterized its angiogenic effect using different experimental procedures. Immunohistochemistry was used to localize EG-VEGF receptors (PROKR1 and PROKR2) in placental and umbilical cord tissue. Primary microvascular placental endothelial cell (HPEC) and umbilical vein-derived macrovascular EC (HUVEC) were used to assess its effects on proliferation, migration, cell survival, pseudovascular organization, spheroid sprouting, permeability and paracellular transport. siRNA and neutralizing antibody strategies were used to differentiate PROKR1- from PROKR2-mediated effects. Our results show that 1) HPEC and HUVEC express both types of receptors 2) EG-VEGF stimulates HPEC's proliferation, migration and survival, but increases only survival in HUVECs. and 3) EG-VEGF was more potent than VEGF in stimulating HPEC sprout formation, pseudovascular organization, and it significantly increases HPEC permeability and paracellular transport. More importantly, we demonstrated that PROKR1 mediates EG-VEGF angiogenic effects, whereas PROKR2 mediates cellular permeability. Altogether, these data characterized angiogenic processes mediated by EG-VEGF, depicted a new angiogenic factor in the placenta, and suggest a novel view of the regulation of angiogenesis in placental pathologies.
Aaltonen, K I; Rosenström, T; Baryshnikov, I; Karpov, B; Melartin, T; Suominen, K; Heikkinen, M; Näätänen, P; Koivisto, M; Joffe, G; Isometsä, E
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.
Chiang, Chung-Hsin; Chu, Ching-Lin; Lee, Tsung-Chin
Joint attention intervention for children with autism spectrum disorders was focused on improving joint engagement and joint attention skills. The purpose of this study was to develop a caregiver-mediated joint engagement intervention program combined with body movement play to investigate the effects of joint engagement/joint attention skills in…
Hongyan, Lin; Zhankui, Chen
Mobile shopping is increasing in prevalence and has become a necessary part of many people's daily lives. However, one main channel for mobile shopping, mobile shopping applications (apps), has not been thoroughly investigated. This study focused on mobile text advertising delivered from mobile shopping apps using the intention to purchase as the dependent variable for testing its marketing effect. In the context of a promotion focus vs. a prevention focus, we used Higgins' regulatory focus theory combined with Ajzen's TPB and Herzog's U&G to analyze the mechanism by which consumers formulate an intention to purchase in a mobile advertising context. This empirical study surveyed 320 consumers who had made a purchase using a mobile shopping app in the previous month. The results showed that infotainment, irritation, and subjective norms were significantly associated with attitudes; in turn, attitudes mediated the impact of these three factors on the intention to purchase. Moreover, a high promotion focus not only strengthened the positive effect of infotainment on attitudes but also intensified the mediation effect of attitudes between infotainment and the intention to purchase. A high prevention focus also consolidated the negative effect of irritation on attitudes as well as reinforced the mediation effect of attitudes between irritation and the intention to purchase. Furthermore, attitudes, subjective norms, and perceived behavioral control collectively impacted the intention to purchase. These findings shed light on ways to customize goods information in mobile advertising and have strong theoretical and practical implications.
Full Text Available Mobile shopping is increasing in prevalence and has become a necessary part of many people's daily lives. However, one main channel for mobile shopping, mobile shopping applications (apps, has not been thoroughly investigated. This study focused on mobile text advertising delivered from mobile shopping apps using the intention to purchase as the dependent variable for testing its marketing effect. In the context of a promotion focus vs. a prevention focus, we used Higgins' regulatory focus theory combined with Ajzen's TPB and Herzog's U&G to analyze the mechanism by which consumers formulate an intention to purchase in a mobile advertising context. This empirical study surveyed 320 consumers who had made a purchase using a mobile shopping app in the previous month. The results showed that infotainment, irritation, and subjective norms were significantly associated with attitudes; in turn, attitudes mediated the impact of these three factors on the intention to purchase. Moreover, a high promotion focus not only strengthened the positive effect of infotainment on attitudes but also intensified the mediation effect of attitudes between infotainment and the intention to purchase. A high prevention focus also consolidated the negative effect of irritation on attitudes as well as reinforced the mediation effect of attitudes between irritation and the intention to purchase. Furthermore, attitudes, subjective norms, and perceived behavioral control collectively impacted the intention to purchase. These findings shed light on ways to customize goods information in mobile advertising and have strong theoretical and practical implications.
Hongyan, Lin; Zhankui, Chen
Mobile shopping is increasing in prevalence and has become a necessary part of many people's daily lives. However, one main channel for mobile shopping, mobile shopping applications (apps), has not been thoroughly investigated. This study focused on mobile text advertising delivered from mobile shopping apps using the intention to purchase as the dependent variable for testing its marketing effect. In the context of a promotion focus vs. a prevention focus, we used Higgins' regulatory focus theory combined with Ajzen's TPB and Herzog's U&G to analyze the mechanism by which consumers formulate an intention to purchase in a mobile advertising context. This empirical study surveyed 320 consumers who had made a purchase using a mobile shopping app in the previous month. The results showed that infotainment, irritation, and subjective norms were significantly associated with attitudes; in turn, attitudes mediated the impact of these three factors on the intention to purchase. Moreover, a high promotion focus not only strengthened the positive effect of infotainment on attitudes but also intensified the mediation effect of attitudes between infotainment and the intention to purchase. A high prevention focus also consolidated the negative effect of irritation on attitudes as well as reinforced the mediation effect of attitudes between irritation and the intention to purchase. Furthermore, attitudes, subjective norms, and perceived behavioral control collectively impacted the intention to purchase. These findings shed light on ways to customize goods information in mobile advertising and have strong theoretical and practical implications. PMID:28690564
The main objectives of this article are to describe the effects of mediated learning experience (MLE) strategies in mother-child interactions on the child's cognitive modifiability, the effects of distal factors (e.g., socioeconomic status, mother's intelligence, child's personality) on MLE interactions, and the effects of situational variables on MLE processes. Methodological aspects of measurement of MLE interactions and of cognitive modifiability, using a dynamic assessment approach, are discussed. Studies with infants showed that the quality of mother-infant MLE interactions predict later cognitive functioning and that MLE patterns and children's cognitive performance change as a result of intervention programs. Studies with preschool and school-aged children showed that MLE interactions predict cognitive modifiability and that distal factors predict MLE interactions but not the child's cognitive modifiability. The child's cognitive modifiability was predicted by MLE interactions in a structured but not in a free-play situation. Mediation for transcendence (e.g., teaching rules and generalizations) appeared to be the strongest predictor of children's cognitive modifiability. Discussion of future research includes the consideration of a holistic transactional approach, which refers to MLE processes, personality, and motivational-affective factors, the cultural context of mediation, perception of the whole family as a mediational unit, and the "mediational normative scripts."
Uysal, Recep; Satici, Seydi Ahmet; Akin, Ahmet
This study examined the mediating effects of Facebook addiction on the relationship between subjective vitality and subjective happiness. 297 university students (157 women, 140 men; M age = 20.1 yr., SD = 1.3) were administered the Facebook Addiction Scale, the Subjective Vitality Scale, and the Subjective Happiness Scale. Hierarchical regression analysis showed that Facebook addiction partially mediated the relationship between subjective vitality and subjective happiness.
Liu, S; Wang, Z; Zhao, C; Huang, X; Liang, X; Wang, X; Lu, S; Scherpbier, R W
To examine the effects of early comprehensive interventions on home environment and child neurodevelopment among children younger than 3 years in poor rural areas of China, as well as the underlying mediating and moderating mechanisms. Non-randomized intervention study was conducted among 216 children aged 0-3 years in Shanxi province of China. Based on a 2 × 2 factor design, children in Lin and Fenxi County were assigned to an intervention group with duration less than 1 year (n = 26) or an intervention group with duration longer than 1 year (n = 82), while children in Fangshan County served as a control group with duration less than 1 year (n = 30) or a control group with duration longer than 1 year (n = 78). The control group received national public health services (NPHS), while the intervention group received NPHS plus comprehensive interventions covering health, nutrition, early psychosocial stimulation, and child protection. Home environment (Infant-Toddler Home Observation for Measurement of the Environment [HOME]) and child neurodevelopment (Ages and Stages Questionnaire [ASQ]) were measured by observation and interview with mothers after the intervention program. The intervention group showed significantly higher overall HOME, organization, learning materials, and involvement than the control group, only for a duration longer than 1 year. Children in the intervention group performed better in overall ASQ, fine motor, problem-solving, and personal-social than children in the control group. Moderated mediation analyses indicated that there were significantly indirect effects of treatment on overall ASQ through overall HOME, organization, and involvement only when the duration was longer than 1 year. Early comprehensive interventions longer than 1 year improve home environment and promote child neurodevelopment among children younger than 3 years in poor rural areas. What is more, effects of early comprehensive interventions longer than 1 year on
Kang, Yun-Mi; Chung, Kyung-Sook; Kook, In-Hoon; Kook, Yoon-Bum; Bae, Hyunsu; Lee, Minho; An, Hyo-Jin
Although bee venom (BV) is a toxin that causes bee stings to be painful, it has been widely used clinically for the treatment of certain immune‑associated diseases. BV has been used traditionally for the treatment of chronic inflammatory diseases. In this regard, the present study analyzed the effect of BV on the regulation of inflammatory mediator production by mast cells and their allergic inflammatory responses in an animal model. HMC‑1 cells were treated with BV prior to stimulation with phorbol‑12‑myristate 13‑acetate plus calcium ionophore A23187 (PMACI). The production of allergy‑associated pro‑inflammatory mediators was examined, and the underlying mechanisms were investigated. Furthermore, to investigate whether BV exhibits anti‑inflammatory effects associated with anti‑allergic effects in vivo, a compound 48/80‑induced anaphylaxis model was used. BV inhibited histamine release, mRNA expression and production of cytokines in the PMACI‑stimulated HMC‑1 cells. Furthermore, the inhibitory effects of BV on mitogen‑activated protein kinase (MAPK), MAPK kinase, signal transducer and activator of transcription 3 (STAT3) and Akt were demonstrated. The present study also investigated the ability of BV to inhibit compound 48/80‑induced systemic anaphylaxis in vivo. BV protected the mice against compound 48/80‑induced anaphylactic‑associated mortality. Furthermore, BV suppressed the mRNA expression levels of pro‑inflammatory cytokines, and suppressed the activation of MAPK and STAT3 in this model. These results provide novel insights into the possible role of BV as a modulator for mast cell‑mediated allergic inflammatory disorders.
Devos, Geert; Tuytens, Melissa; Hulpia, Hester
This study examines the relation between principals' leadership and teachers' organizational commitment, mediated by distributed leadership. Data were collected from 1,495 teachers in 46 secondary schools. Structural equation modeling indicated that the effect of principals' leadership on teachers' organizational commitment is…
Haenen, Sharon; Nyklíček, Ivan; VAN Son, Jenny
BACKGROUND: There is increasing evidence that mindfulness-based interventions reduce psychological distress in various medical populations. However, it has hardly been studied if these effects are mediated by an increase in mindfulness. The aim of this study was to examine mediating effects...... of various mindfulness facets on effects of a Mindfulness Based Cognitive Therapy (MBCT) on perceived stress and mood. METHODS: Outpatients with diabetes types 1 and 2 and low levels of emotional wellbeing were randomized into a group receiving MBCT (n=70) or a waiting-list control group (n=69). Primary...... outcomes were mood and perceived stress. Before, after and at follow-up (6months post intervention) relevant questionnaires were completed. RESULTS: Mediation analysis using bootstrap resampling indicated that increases in total mindfulness and the facets observing and nonreactivity mediated the effects...
The present study examined the relationship between two categories of religious involvement, namely religious belief and religious behavior, and life satisfaction among Korean Christians (N = 278) with spiritual well-being and self-esteem as potential mediators in this relationship by using structural equation modeling (SEM). The results supported the full mediated structural model and indicated that religious belief had a significant indirect effect on life satisfaction through the mediators, spiritual well-being and self-esteem. Religious behavior did not have an indirect or direct effect on life satisfaction among Korean Christians. The significance, implications, and limitations of the study were discussed.
Janet L. Johnson
Full Text Available Project SOAR provided after-school programs that afforded expanded learning opportunities to help students succeed in local public schools and to contribute to the general welfare of the community. Program components focused on building students’ academic skills and positive attitudes, aided by teachers, mentors, parent education, and local agencies. Instructional programs were conducted to help reduce drug use and violence. Activities included academic assistance, technology training, mentoring, service learning projects, and education in life skills and the arts. Parent involvement was encouraged. Behavioral and academic outcomes—especially at the high school level—were analyzed to determine program effectiveness regarding academic achievement, dropout rates, and rates and frequency of suspensions. Successful program elements and strategies are noted.
Deković, M.; Asscher, J.J.; Hermanns, J.; Reitz, E.; Prinzie, P.; van den Akker, A.L.
The present study aimed to (1) determine the long-term effectiveness of Home-Start, a preventive parenting program, and (2) test the hypothesis that changes in maternal sense of competence mediate the program's effects. Participants were 124 mothers (n = 66 intervention, n = 58 comparison). Four
Noh, Jin-Won; Park, Hyunchun; Kim, Minji; Kwon, Young Dae; Kim, Jin-Seok; Yu, Shieun
This study investigated the mediation effect of stress between the experience of discrimination and life satisfaction among North Korean refugees who resettled in South Korea. The findings of the current study provide empirical evidence for the need of social interventions to mitigate adverse effects of stress on North Korean refugees who are subject to social discrimination on a daily basis. In this study, we included 500 subjects among 2,138 North Korean refugees who took refuge in South Korea in 2007. The interview started from April 6th 2009 and finished on May 25th 2009. We conducted moderator effect analysis with Path analysis was conducted because we confirm the experience of discrimination was affected by life satisfaction and stress can affected life satisfaction as a moderator. The experience of discrimination significantly affects stress and stress significantly affects life satisfaction. However, the experience of discrimination was not directly related to life satisfaction. The more stress the study respondents experienced, the lower the life satisfaction they reported. The present finding suggests that the effects of discriminating experiences on the life satisfaction of North Korean refugees in South Korea were mediated by their own perceived stress.
Full text of publication follows: starting from the assumptions of support theory, this project analyzed the extent to which the specification of potential side effects influences the perceived risk associated, with a particular medication. Respondents were presented with an instruction leaflet for a medication which indicated (a) the overall probability that a side effect will occur or (b) the probability of occurrence of several specific side effects. Support theory predicts that the cognitive availability of potential side effects and therefore the perceived risk increases as a function of the specificity with which the side effects are presented. In contrast the evaluation-mediation hypothesis predicts that a more detailed presentation of potential side effects enhances the perceived quality of the information leaflet and thereby leads to a reduction of perceived risk. Support for the evaluation-mediation hypothesis was found in a series of studies which included the editing hypothesis and the elaboration likelihood model as additional explanations: the more detailed the information about potential side effects, the lower the estimated risk of suffering a side effect on taking the medication. As predicted, the influence of presentation specificity on perceived risk was mediated almost exclusively by the perceived quality of the information leaflet. A current series of studies seeks to support the evaluation-mediation hypothesis in a completely different domain, the perceived risk of environmental pollution by motor vehicles. (author)
Chughtai, Aamir Ali
This study investigated the mediating role of organizational identification and psychological safety in the relationship between servant leadership and two employee outcomes: employee voice and negative feedback seeking behavior. The sample for this study comprised of 174 full-time employees drawn from a large food company based in Pakistan. Results showed that organizational identification and psychological safety partially mediated the effects of servant leadership on voice and negative feedback seeking behavior. The theoretical and practical implications of this research are discussed.
Umeh, Kanayo F
There is limited understanding of ethnic inequalities in doctor-patient communication regarding personal care plans (PCPs). This study investigated the mediating effects of positive mental wellbeing on differences in PCP-related doctor-patient communication amongst South Asian and Caucasian UK residents. Data from 10,980 respondents to the 2013 Health Survey for England was analysed using bootstrapping methods. Constructs from the WEMWBS (Warwick and Edinburgh Mental Wellbeing Scale) (Stewart-Brown, S., and K. Janmohamed. 2008. Warwick, UK) were assessed as mediators of relations between ethnicity and several doctor-patient communication variables, including PCP-related interactions; (a) had a PCP-related discussion about a long-term condition with a doctor/nurse, and (b) had this conversation within the past year, (c) agreed to a PCP with a health professional; and (d) talked to a doctor in the past 2 weeks. Bootstrapped mediation analysis (Hayes, A. F. 2013. Introduction to Mediation, Moderation, and Conditional Process Analysis: A Regression-based Approach. New York, NY: The Guilford Press) showed that three positive mind-sets mediated associations between ethnicity and doctor-patient contact, including PCP-related communication. Being able to make up one's mind (ab = -0.05; BC a CI [-0.14, 0.01]) mediated the effect of ethnicity on agreeing to a PCP, while having energy to spare (ab = 0.07; BC a CI [-0.04, 0.12]), and feeling good about oneself (ab = 0.03; BC a CI [0.01, 0.07]), mediated ethnic effects on talking to a doctor during the past fortnight. The mediating effect of reported energy persisted after controlling for medical history, perceived health, and other covariates. Ethnic disparities in doctor-patient interaction, including PCP-related communication, are partly explained by positive mental wellbeing. Gauging positive psychological moods in patients, particularly self-worth, self-perceived vigour and decisiveness, are relevant to
Niesta Kayser, Daniela; Graupmann, Verena; Fryer, James W.; Frey, Dieter
Two experiments examined how individuals respond to a restriction presented within an approach versus an avoidance frame. In Study 1, working on a problem-solving task, participants were initially free to choose their strategy, but for a second task were told to change their strategy. The message to change was embedded in either an approach or avoidance frame. When confronted with an avoidance compared to an approach frame, the participants’ reactance toward the request was greater and, in turn, led to impaired performance. The role of reactance as a response to threat to freedom was explicitly examined in Study 2, in which participants evaluated a potential change in policy affecting their program of study herein explicitly varying whether a restriction was present or absent and whether the message was embedded in an approach versus avoidance frame. When communicated with an avoidance frame and as a restriction, participants showed the highest resistance in terms of reactance, message agreement and evaluation of the communicator. The difference in agreement with the change was mediated by reactance only when a restriction was present. Overall, avoidance goal frames were associated with more resistance to change on different levels of experience (reactance, performance, and person perception). Reactance mediated the effect of goal frame on other outcomes only when a restriction was present. PMID:27242572
Scherr, Kyle C.; Madon, Stephanie; Guyll, Max; Willard, Jennifer; Spoth, Richard
This research examined whether self-verification acts as a general mediational process of self-fulfilling prophecies. The authors tested this hypothesis by examining whether self-verification processes mediated self-fulfilling prophecy effects within a different context and with a different belief and a different outcome than has been used in prior research. Results of longitudinal data obtained from mothers and their adolescents (N = 332) indicated that mothers’ beliefs about their adolescents’ educational outcomes had a significant indirect effect on adolescents’ academic attainment through adolescents’ educational aspirations. This effect, observed over a six year span, provided evidence that mothers’ self-fulfilling effects occurred, in part, because mothers’ false beliefs influenced their adolescents’ own educational aspirations which adolescents then self-verified through their educational attainment. The theoretical and applied implications of these findings are discussed. PMID:21357755
Scherr, Kyle C; Madon, Stephanie; Guyll, Max; Willard, Jennifer; Spoth, Richard
This research examined whether self-verification acts as a general mediational process of self-fulfilling prophecies. The authors tested this hypothesis by examining whether self-verification processes mediated self-fulfilling prophecy effects within a different context and with a different belief and a different outcome than has been used in prior research. Results of longitudinal data obtained from mothers and their adolescents (N=332) indicated that mothers' beliefs about their adolescents' educational outcomes had a significant indirect effect on adolescents' academic attainment through adolescents' educational aspirations. This effect, observed over a 6-year span, provided evidence that mothers' self-fulfilling effects occurred, in part, because mothers' false beliefs influenced their adolescents' own educational aspirations, which adolescents then self-verified through their educational attainment. The theoretical and applied implications of these findings are discussed.
Rosen, Jan B.; Brand, Matthias; Kalbe, Elke
Moral decision making involves affective and cognitive functions like emotional empathy, reasoning and cognitive empathy/theory of mind (ToM), which are discussed to be subject to age-related alterations. Additionally, sex differences in moral decision making have been reported. However, age-related changes in moral decision making from early to late adulthood and their relation to sex and neuropsychological functions have not been studied yet. One hundred ninety seven participants (122 female), aged 19–86 years, were tested with a moral decision making task comprising forced choice “everyday life” situations in which an altruistic option that favors a socially accepted alternative had to be considered against an egoistic option that favors personal benefit over social interests. The percentage of altruistic decisions was analyzed. A structural equation model (SEM) was calculated to test the hypothesis whether age and sex predict altruistic moral decision, and whether relevant neuropsychological domains mediate these hypothesized relationships. A significant relationship between age and moral decision making was found indicating more frequent altruistic decisions with increasing age. Furthermore, women decided more altruistically than men. The SEM showed that both age and sex are significant predictors of altruistic moral decision making, mediated by emotional empathy but not by reasoning. No cognitive empathy and ToM scores were correlated to age and moral decision making at the same time and thus were not included in the SEM. Our data suggest that increasing age and female sex have an effect on altruistic moral decisions, but that this effect is fully mediated by emotional empathy. The fact that changes of moral decision making with age are mediated by emotional empathy can be interpreted in the light of the so-called “positivity effect” and increasing avoidance of negative affect in aging. The mediated sex effect might represent both biological aspects
Barrera, Manuel; Strycker, Lisa A; Mackinnon, David P; Toobert, Deborah J
In behavioral research directed at the treatment of type 2 diabetes, the challenge is to understand how interventions might facilitate long-term lifestyle changes. The Mediterranean Lifestyle Program (MLP) is an intervention for postmenopausal women diagnosed with type 2 diabetes that has shown promising effects on outcomes that include increased physical activity and reduced fat consumption. The present study extended previous findings by evaluating diet-specific and activity-specific social-ecological resources as possible mediators of intervention effects over a 2-year period. Percent calories from saturated fat and caloric expenditure per week in all physical activities were assessed with self-report questionnaires. The MLP was successful in increasing participants' use of diet-specific and activity-specific family/friend and neighborhood resources. There was some evidence that changes in those resources mediated intervention effects on saturated fat consumption and physical activity outcomes. The experimental manipulation of mediators and the demonstrated mediational effects provided some support for the conclusion that social-ecological resources can contribute to improvements in healthful lifestyles for women with type 2 diabetes. (c) 2008 APA, all rights reserved
Tudor-Locke Catrine E
Full Text Available Abstract Background Many studies have reported significant behavioral impact of physical activity interventions. However, few have examined changes in potential mediators of change preceding behavioral changes, resulting in a lack of information concerning how the intervention worked. Our purpose was to examine mediation effects of changes in psychosocial variables on changes in physical activity in type 2 diabetes patients. Methods Ninety-two patients (62 ± 9 years, 30, 0 ± 2.5 kg/m2, 69% males participated in a randomized controlled trial. The 24-week intervention was based on social-cognitive constructs and consisted of a face-to-face session, telephone follow-ups, and the use of a pedometer. Social-cognitive variables and physical activity (device-based and self-reported were collected at baseline, after the 24-week intervention and at one year post-baseline. PA was measured by pedometer, accelerometer and questionnaire. Results Post-intervention physical activity changes were mediated by coping with relapse, changes in social norm, and social modeling from family members (p ≤ 0.05. One-year physical activity changes were mediated by coping with relapse, changes in social support from family and self-efficacy towards physical activity barriers (p ≤ 0.05 Conclusions For patients with type 2 diabetes, initiatives to increase their physical activity could usefully focus on strategies for resuming regular patterns of activity, on engaging family social support and on building confidence about dealing with actual and perceived barriers to activity. Trial Registration NCT00903500, ClinicalTrials.gov.
Park, Yu Kyoung; Song, Ji Hoon; Yoon, Seung Won; Kim, Jungwoo
Purpose: The purpose of this study is to investigate the mediating effect of work engagement on the relationship between learning organization and innovative behavior. Design/methodology/approach: This study used surveys as a data collection tool and implemented structural equation modeling for empirically testing the proposed research model.…
Jacky T. Thomas
Full Text Available Personal distress is an aspect of the empathy construct which has been negatively associated with a range of psychological and behavioral problems. However, it is unclear whether mindfulness serves to buffer these negative relationships. This study examines direct effects and mediation effects of personal distress and mindfulness among three measures of professional quality of life: compassion fatigue, burnout, and compassion satisfaction. This model was tested using a sample of clinical social workers (n = 171. Results indicated that higher personal distress is significantly associated with higher compassion fatigue and burnout and lower compassion satisfaction, while mindfulness is significantly associated with lower compassion fatigue and burnout and higher compassion satisfaction. Mediation analyses showed significant indirect effects on all three measures of professional quality of life, with effect sizes in the small to moderate range. The indirect effects of mindfulness via the personal distress path accounted for 14-22% of the total effect of mindfulness on the three measures of professional quality of life. Implications for the education and training of social workers are discussed.
In the relevant literature, it is often debated whether learning programming requires high-level thinking skills, the lack of which consequently results in the failure of students in programming. The complex nature of programming and individual differences, including study approaches, thinking styles, and the focus of supervision, all have an…
Marsack, Christina N.; Samuel, Preethy S.
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…
Amris Rusli Tanjung
Full Text Available This paper investigate the effects of superiors performance evaluation behaviors on subordinates work-related attitudes mediated used performance measure. We used leadership style initiating structure and consideration and performance measure use objective and subjective measures on managerial work related attitudes goal clarity and evaluation fairness. We test our hypotheses using survey data from 56 middle-level managers in 4 services organizations. The results from Structural Equation Model with PLS show that an initiating structure leadership style has significant effect goal clarity and used objective performance measure mediated relationship initiating structure and goal clarity and used subjective performance measure not mediated relationship consideration leadership style and fairness in evaluation. Consideration leadership behavior instead only has a direct impact on fairness in evaluation. These findings have important implications for management accounting research on superiors use of performance measures and provide an explanation of some of the problematic findings in the literature.
Yu, Nancy Xiaonan; Liu, Chang; Yue, Zhenzhu
The number of Hong Kong citizens living in mainland China is increasing. The process of acculturation may create opportunities for psychological growth. This study aimed at examining whether resilience mediated the effects of acculturation on psychological growth in college students from Hong Kong to Guangzhou. In this cross-sectional survey, 164 college students in Guangzhou who were Hong Kong permanent residents (female: 46%, age: 21.09 ± 1.50) joined the study. The integration group reported more psychological growth than the assimilation, separation, and marginalization groups. Resilience partially mediated the effect of integration on psychological growth and fully mediated the effect of marginalization on psychological growth. Resilience represents one of the mechanisms to explain beneficial effects of integration on psychological growth in college students from Hong Kong to Guangzhou. Theoretical considerations to rethink the acculturation model, implications for developing intervention programs, and recommendations for future research are discussed.
Agler, Robert; De Boeck, Paul
Mediation analysis has become a very popular approach in psychology, and it is one that is associated with multiple perspectives that are often at odds, often implicitly. Explicitly discussing these perspectives and their motivations, advantages, and disadvantages can help to provide clarity to conversations and research regarding the use and refinement of mediation models. We discuss five such pairs of perspectives on mediation analysis, their associated advantages and disadvantages, and their implications: with vs. without a mediation hypothesis, specific effects vs. a global model, directness vs. indirectness of causation, effect size vs. null hypothesis testing, and hypothesized vs. alternative explanations. Discussion of the perspectives is facilitated by a small simulation study. Some philosophical and linguistic considerations are briefly discussed, as well as some other perspectives we do not develop here. PMID:29187828
Agler, Robert; De Boeck, Paul
Mediation analysis has become a very popular approach in psychology, and it is one that is associated with multiple perspectives that are often at odds, often implicitly. Explicitly discussing these perspectives and their motivations, advantages, and disadvantages can help to provide clarity to conversations and research regarding the use and refinement of mediation models. We discuss five such pairs of perspectives on mediation analysis, their associated advantages and disadvantages, and their implications: with vs. without a mediation hypothesis, specific effects vs. a global model, directness vs. indirectness of causation, effect size vs. null hypothesis testing, and hypothesized vs. alternative explanations. Discussion of the perspectives is facilitated by a small simulation study. Some philosophical and linguistic considerations are briefly discussed, as well as some other perspectives we do not develop here.
Poss, Zachary C.; Ebmeier, Christopher C.
The Mediator complex is a multi-subunit assembly that appears to be required for regulating expression of most RNA polymerase II (pol II) transcripts, which include protein-coding and most non-coding RNA genes. Mediator and pol II function within the pre-initiation complex (PIC), which consists of Mediator, pol II, TFIIA, TFIIB, TFIID, TFIIE, TFIIF and TFIIH and is approximately 4.0 MDa in size. Mediator serves as a central scaffold within the PIC and helps regulate pol II activity in ways that remain poorly understood. Mediator is also generally targeted by sequence-specific, DNA-binding transcription factors (TFs) that work to control gene expression programs in response to developmental or environmental cues. At a basic level, Mediator functions by relaying signals from TFs directly to the pol II enzyme, thereby facilitating TF-dependent regulation of gene expression. Thus, Mediator is essential for converting biological inputs (communicated by TFs) to physiological responses (via changes in gene expression). In this review, we summarize an expansive body of research on the Mediator complex, with an emphasis on yeast and mammalian complexes. We focus on the basics that underlie Mediator function, such as its structure and subunit composition, and describe its broad regulatory influence on gene expression, ranging from chromatin architecture to transcription initiation and elongation, to mRNA processing. We also describe factors that influence Mediator structure and activity, including TFs, non-coding RNAs and the CDK8 module. PMID:24088064
Intriligator, Kenneth; Sudano, Matthew
There has been interest in generalizing models of gauge mediation of supersymmetry breaking. As shown by Meade, Seiberg, and Shih (MSS), the soft masses of general gauge mediation can be expressed in terms of the current two-point functions of the susy-breaking sector. We here give a simple extension of their result which provides, for general gauge mediation, the full effective potential for squark pseudo-D-flat directions. The effective potential reduces to the sfermion soft masses near the origin, and the full potential, away from the origin, can be useful for cosmological applications. We also generalize the soft masses and effective potential to allow for general gauge mediation by Higgsed gauge groups. Finally, we discuss general gauge mediation in the limit of small F-terms, and how the results of MSS connect with the analytic continuation in superspace results, based on a spurion analysis.
Mereish, Ethan H; N'cho, Hammad S; Green, Carlton E; Jernigan, Maryam M; Helms, Janet E
Discrimination is related to depression and poor self-esteem among Black men. Poorer self-esteem is also associated with depression. However, there is limited research identifying how self-esteem may mediate the associations between discrimination and depressive symptoms for disparate ethnic groups of Black men. The purpose of this study was to examine ethnic groups as a moderator of the mediating effects of self-esteem on the relationship between discrimination and depressive symptoms among a nationally representative sample of African American (n = 1201) and Afro-Caribbean American men (n = 545) in the National Survey of American Life. Due to cultural socialization differences, we hypothesized that self-esteem would mediate the associations between discrimination and depressive symptoms only for African American men, but not Afro-Caribbean American men. Moderated-mediation regression analyses indicated that the conditional indirect effects of discrimination on depressive symptoms through self-esteem were significant for African American men, but not for Afro-Caribbean men. Our results highlight important ethnic differences among Black men.
Eather, Narelle; Morgan, Philip J; Lubans, David R
Few studies have examined the mediators of behavior change in successful school-based physical activity interventions. The aim of this study was to explore potential mediators of physical activity in the Fit-4-Fun program for primary school children. Group randomized controlled trial. Four primary schools were recruited in April, 2011 and randomized by school into intervention or control conditions. Participants included 213 children (mean age = 10.7 years ± 0.6; 52.2% female) with the treatment group (n = 118) completing the 8-week multi-component Fit-4-Fun program. Participants were assessed at baseline, 3- and 6-months. Physical activity was measured using Yamax SW700 pedometers (mean steps/day) and questionnaires were used to assess constructs from Social Cognitive Theory and Competence Motivation Theory. Hypothesized mediators measured included social support from peers, parents and teachers; physical activity self-efficacy (barrier and task); enjoyment; and perceived school physical environment. Mediation was assessed using Preacher and Hayes' multiple mediation regression SPSS macro. Action theory (A), conceptual theory (B) and the significance of the product of coefficients (AB) are reported. The intervention had a significant effect on physical activity (pFun program successfully targeted social support for physical activity provided by classroom teachers which contributed to improved physical activity in children. These results demonstrate that classroom teachers play a key role in influencing physical activity behavior outcomes in children.Trial Registration No: ACTRN12611000976987.
McAdoo, Ryan M; Key, Kylie N; Gronlund, Scott D
Two broad approaches characterize the type of evidence that mediates recognition memory: discrete state and continuous. Discrete-state models posit a thresholded memory process that provides accurate information about an item (it is detected) or, failing that, no mnemonic information about the item. Continuous models, in contrast, posit the existence of graded mnemonic information about an item. Evidence favoring 1 approach over the other has been mixed, suggesting the possibility that the mediation of recognition memory may be adaptable and influenced by other factors. We tested this possibility with 2 experiments that varied the semantic similarity of word targets and fillers. Experiment 1, which used semantically similar fillers, displayed evidence of continuous mediation (contrary to Kellen & Klauer, 2015), whereas Experiment 2, which used semantically dissimilar fillers, displayed evidence of discrete mediation. The results have implications for basic theories of recognition memory, as well as for theories of applied domains like eyewitness identification. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Full Text Available Abstract Background In this study, exposure refers to survivors who suffered from life-changing situations, such as personal injuries, the deaths or injury of family members, relatives or friends or the loss of or damage to personal or family property, as a result of the earthquake. The mediating effect of risk perception on the exposure and psychological health in survivors from the Longmen Shan Fault area and the moderating effect of social support on the relationship between risk perception and psychological health were both examined. Method A cross-sectional survey was conducted in a local Longmen Shan Fault area near the epicenter of the 2008 Wenchuan earthquake. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV, the standard Chinese 12-item Short Form (SF-12v2, and the Social Support Rating Scale (SSRS were used to interview 2,080 earthquake survivors in the period one-year after the earthquake. Based on the environment and the characteristics of the Longmen Shan Fault area, a risk perception questionnaire was developed to evaluate survivor risk perception. Factor and regression analyses were conducted to determine the hypothetical relations. Results The analyses provided effective support for the hypothesized model. Survivor risk perception was classified into direct risk perception and indirect risk perception. Survivor direct risk perception was found to play a partial mediating role in the relationship between exposure and the two domains (Physical component summary (PCS and the Mental component summary (MCS of psychological health. Survivor indirect risk perception was found to have a only partial mediating effect on the association between exposure and MCS. Social support was found to moderate the influence of risk perception on psychological health. Conclusion Risk communication should be considered in future post-earthquake psychological assistance programs and social support strategies could also be
Goddard, Kate; Roudsari, Abdul; Wyatt, Jeremy C
Automation bias (AB)--the tendency to over-rely on automation--has been studied in various academic fields. Clinical decision support systems (CDSS) aim to benefit the clinical decision-making process. Although most research shows overall improved performance with use, there is often a failure to recognize the new errors that CDSS can introduce. With a focus on healthcare, a systematic review of the literature from a variety of research fields has been carried out, assessing the frequency and severity of AB, the effect mediators, and interventions potentially mitigating this effect. This is discussed alongside automation-induced complacency, or insufficient monitoring of automation output. A mix of subject specific and freetext terms around the themes of automation, human-automation interaction, and task performance and error were used to search article databases. Of 13 821 retrieved papers, 74 met the inclusion criteria. User factors such as cognitive style, decision support systems (DSS), and task specific experience mediated AB, as did attitudinal driving factors such as trust and confidence. Environmental mediators included workload, task complexity, and time constraint, which pressurized cognitive resources. Mitigators of AB included implementation factors such as training and emphasizing user accountability, and DSS design factors such as the position of advice on the screen, updated confidence levels attached to DSS output, and the provision of information versus recommendation. By uncovering the mechanisms by which AB operates, this review aims to help optimize the clinical decision-making process for CDSS developers and healthcare practitioners.
Gunreben-Stempfle, Birgit; Griessinger, Norbert; Lang, Eberhard; Muehlhans, Barbara; Sittl, Reinhard; Ulrich, Kathrin
To investigate if the effectiveness of a 96-hour multidisciplinary headache treatment program exceeds the effectiveness of a 20-hour program and primary care. When dealing with chronic back pain, low-intensity multidisciplinary treatment yields no significantly better results than standard care and monodisciplinary therapy; however, high-intensity treatment does. For multidisciplinary headache treatment, such comparisons are not yet available. In a previous study undertaken by our Pain Center, the outcome of a minimal multidisciplinary intervention model (20-hour) did not exceed primary care. Forty-two patients suffering from frequent headaches (20 +/- 9 headache days/month; range: 8-30) were treated and evaluated in a 96-hour group program. The results were compared with the outcomes of the previous study. Subjects who had undergone either the 20-hour multidisciplinary program or the primary care were used as historical control groups. A significant reduction in migraine days (P tension-type headache days (P tension-type headache days (P = .016), and frequency of migraine attacks (P = .016). In comparison with the 20-hour multidisciplinary program, the 96-hour program showed significantly better effects only in the reduction of migraine days (P = .037) and depression score (P = .003). The responder-rates (> or =50% improvement) in the 96-hour program were significantly higher than in the 20-hour program (migraine days, P = .008; tension-type headache days, P = .044) and primary care (migraine days, P = .007; tension-type headache days, P = .003; tension-type headache intensity, P = .037). The effect sizes were small to medium in the 96-hour program. Particularly with the reduction of migraine symptomatology, the 96-hour program performed better than the 20-hour program, which produced only negligible or small effects. Intensive multidisciplinary headache treatment is highly effective for patients with chronic headaches. Furthermore, migraine symptomatology
Isarida, Toshiko K; Kubota, Takayuki; Nakajima, Saki; Isarida, Takeo
The present study reexamined the mood-mediation hypothesis for explaining background-music-dependent effects in free recall. Experiments 1 and 2 respectively examined tempo- and tonality-dependent effects in free recall, which had been used as evidence for the mood-mediation hypothesis. In Experiments 1 and 2, undergraduates (n = 75 per experiment) incidentally learned a list of 20 unrelated words presented one by one at a rate of 5 s per word and then received a 30-s delayed oral free-recall test. Throughout the study and test sessions, a piece of music was played. At the time of test, one third of the participants received the same piece of music with the same tempo or tonality as at study, one third heard a different piece with the same tempo or tonality, and one third heard a different piece with a different tempo or tonality. Note that the condition of the same piece with a different tempo or tonality was excluded. Furthermore, the number of sampled pieces of background music was increased compared with previous studies. The results showed neither tempo- nor tonality-dependent effects, but only a background-music-dependent effect. Experiment 3 (n = 40) compared the effects of background music with a verbal association task and focal music (only listening to musical selections) on the participants' moods. The results showed that both the music tempo and tonality influenced the corresponding mood dimensions (arousal and pleasantness). These results are taken as evidence against the mood-mediation hypothesis. Theoretical implications are discussed.
Zhao, Huanhuan; Zhang, Heyun; Xu, Yan
The present study attempts to examine the effect of perceived descriptive norms on corrupt intention (e.g., bribe-taking intention) and then further explore the psychological mechanism underlying this effect. Based on social cognitive theory, we established a mediation model in which moral disengagement partially mediated the link between perceived descriptive norms and corrupt intention. In Study 1, participants (N = 690) completed a series of questionnaires, and the results demonstrated that, while perceived descriptive norms were positively associated with corrupt intention, it was partially mediated by moral disengagement. In Study 2, we conducted a priming experiment (N = 161) to test the causal relationship and psychological mechanism between perceived descriptive norms and corrupt intention. The results revealed that perceived descriptive norms triggered the propensity of individuals to morally disengage, which in turn, partially increased their corrupt intention. This study not only extends previous research by providing evidence that moral disengagement may be one of the reasons why perceived descriptive norms facilitate corrupt intention, but also suggests that reshaping normative beliefs and preventing the moral disengagement of individuals may be the effective ways to curb corrupt behaviours. © 2017 International Union of Psychological Science.
Mª del Mar Ramos-González
Full Text Available This article investigates how a management approach based on sustainable entrepreneurship can positively affect corporate reputation. The analysis showed that this effect is enhanced by the mediating effect of good governance based on ethical behavior. The empirical study was conducted using data for 104 large Spanish firms defined as sustainable by the Corporate Reputation Business Monitor (MERCO ranking.
Ulfsdotter, Malin; Enebrink, Pia; Lindberg, Lene
Parenting programs have been highlighted as a way of supporting and empowering parents. As programs designed to promote children's health and well-being are scarce, a new health-promotion program, All Children in Focus, has been developed. The purpose of this trial was to evaluate the potential effectiveness of the program in promoting parental self-efficacy and child health and development, as well as to investigate possible moderators of these outcomes. A multicenter randomized waitlist-controlled trial was conducted. The trial included 621 parents with children aged 3-12 years. Parents were randomized to receive the intervention directly or to join a waitlist control group. Parents completed questionnaires at baseline, 2 weeks after the intervention, and 6 months post-baseline. To evaluate potential effects of the program, as well as any moderating variables, multilevel modeling with a repeated-measures design was applied. Parents in the intervention group reported that their self-efficacy (p parents in the control group. One variable was found to moderate both outcomes: parents' positive mental health. Furthermore, parents' educational level and number of children moderated parental self-efficacy, while the children's age moderated child health and development. Having a poor positive mental health, a university-level education, more than one child in the family, and older children, made the families benefit more. In the first randomized controlled trial of All Children in Focus, we found that the program appears to promote both parental self-efficacy and children's health and development in a general population. Additionally, we found that families may benefit differently depending on their baseline characteristics. This contributes to an existing understanding of the advantages of offering universal parenting programs as a public health approach to strengthening families. However, further research is needed to investigate long-term effects and mediating
Okubo, Ryo; Inoue, Takeshi; Hashimoto, Naoki; Suzukawa, Akio; Tanabe, Hajime; Oka, Matsuhiko; Narita, Hisashi; Ito, Koki; Kako, Yuki; Kusumi, Ichiro
Previous studies indicated that personality traits have a mediator effect on the relationship between childhood abuse and depressive symptoms in major depressive disorder and nonclinical general adult subjects. In the present study, we aimed to test the hypothesis that personality traits mediate the relationship between childhood abuse and depressive symptoms in schizophrenia. We used the following questionnaires to evaluate 255 outpatients with schizophrenia: the Child Abuse and Trauma Scale, temperament and character inventory, and Patients Health Questionnire-9. Univariate analysis, multiple regression analysis, and structured equation modeling (SEM) were used to analyze the data. The relationship between neglect and sexual abuse and the severity of depressive symptoms was mostly mediated by the personality traits of high harm avoidance, low self-directedness, and low cooperativeness. This finding was supported by the results of stepwise multiple regression analysis and the acceptable fit indices of SEM. Thus, our results suggest that personality traits mediate the relationship between childhood abuse and depressive symptoms in schizophrenia. The present study and our previous studies also suggest that this mediator effect could occur independent of the presence or type of mental disorder. Clinicians should routinely assess childhood abuse history, personality traits, and their effects in schizophrenia. Copyright © 2017. Published by Elsevier B.V.
Guh, Wei-Yuan; Lin, Shang-Ping; Fan, Chwei-Jen; Yang, Chin-Fang
This study investigated the mediating role of institutional trust and affective commitment on the relationship between organizational justice and organizational citizenship behaviors. The study participants were 315 faculty members at 67 public/private universities of technology and vocational colleges in Taiwan. Structural equation modeling was used to analyze the relationships between the variables and assess the goodness of fit of the overall model. Organizational justice was positively related to institutional trust and there was an indirect effect of organizational justice on affective commitment through institutional trust. In addition, the relation between institutional trust and affective commitment was positive and affective commitment was shown to have a positive relation to organizational citizenship behaviors. Institutional trust was found to indirectly affect organizational citizenship behaviors through affective commitment. Most importantly, this study suggested a mediating effect of institutional trust and affective commitment on the relation between organizational justice and organizational citizenship behaviors. Implications, limitations, and future research were also discussed.
Mak, Kwok-Kei; Cerin, Ester; McManus, Alison M; Lai, Ching-Man; Day, Jeffrey R; Ho, Sai-Yin
This study investigated the mediating role of body mass index (BMI) in the relationship between physical activity and body esteem in adolescents. Nine hundred and five Hong Kong Chinese students aged 12-18 years participated in a cross-sectional study in 2007. Students' BMI was computed as an indicator of their body composition. Their physical activity level and body esteem were examined using the Physical Activity Rating for Children and Youth (PARCY) and Body Esteem Scale (BES), respectively. Structural equation modelling was used to investigate the mediating effects of BMI and physical activity in predicting body esteem, with stratification by sex. The overall fit of the hypothesized models was satisfactory in boys (NFI = 0.94; NNFI = 0.88; CFI = 0.95; RMSEA = 0.07) and girls (NFI = 0.89; NNFI = 0.77; CFI = 0.91; RMSEA = 0.11). When BMI was considered as a mediator, higher physical activity had a significant negative total effect on body esteem in boys, but not in girls. The indirect effect of higher physical activity on body esteem via BMI was positive in boys, but negative in girls. Regular physical activity may help overweight adolescents, especially boys, improve their body esteem. Kinesiologists and health professionals could explore the use of physical activity prescriptions for weight management, aiming at body esteem improvement in community health programs for adolescents. Among Western adolescents, negative body esteem is more pervasive in girls than in boys. There are consistent findings of the association between higher body mass index and lower body esteem in adolescents, but the association between physical activity and body esteem are equivocal. A negative association between body mass index and body esteem was found in both Hong Kong adolescent boys and girls. The indirect effect of physical activity on body esteem via body mass index was positive in Hong Kong adolescent boys, but negative in girls.
In policy evaluations, interest may focus on why a particular treatment works. One tool for understanding why treatments work is causal mediation analysis. In this essay, I focus on the assumptions needed to estimate mediation effects. I show that there is no "gold standard" method for the identification of causal mediation effects. In…
This study investigates the effectiveness of pair programming on student learning and satisfaction in introductory programming courses. Pair programming, used in the industry as a practice of an agile development method, can be adopted in classroom settings to encourage peer learning, increase students' social skills, and enhance student…
Lund, Asta Breinholt; Jæger, Mads Meier
This study analyzes whether teachers' evaluations of children's academic skills mediate the effect of cultural capital on educational performance. We use ECLS-K data with repeated measures on children in 1st, 3rd and 5th grade and apply fixed effects models, that control for unobserved time...... invariant child and family characteristics. The analysis shows that teacher evaluations have positive effect on educational performance, but that cultural capital has no effect on teacher evaluations. Instead cultural capital has a direct positive effect on educational performance....
Le, Yunying; Fredman, Steffany J; Feinberg, Mark E
The current study examined parenting stress (disaggregated into personal distress and child rearing stress) at 12 months postpartum as a mediator of the longitudinal association between parental negative affectivity at 6 months postpartum and harsh parenting at 3 years postpartum for first-time parents with a child transitioning from late toddlerhood to the early preschool years. Analyses were conducted using Mediation for Actor Partner Interdependence Modeling in a sample of 164 couples who participated in a randomized controlled trial of a universal, couple-based transition to parenthood program. There were indirect actor effects of negative affect on a parent's own harsh parenting through both dimensions of parenting stress, with a stronger mediating effect for personal distress than child rearing stress. There were also indirect partner effects of negative affect on one's partner's harsh parenting through the partner's parenting stress, with a stronger indirect partner effect from mothers' negative affect to fathers' harsh parenting than vice versa. Specifically, the mediating effect of personal distress was found for both mothers and fathers, whereas the mediating effect of child rearing stress was found from mothers' negative affect to fathers' harsh parenting only. Findings highlight the importance of a dyadic approach in examining the longitudinal association between negative affect and harsh parenting and suggest that reducing parenting stress in the first year postpartum may decrease the risk of future harsh parenting among couples in which one or both partners experience negative affectivity. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
VanderWeele, Tyler J.
The causal inference literature has provided definitions of direct and indirect effects based on counterfactuals that generalize the approach found in the social science literature. However, these definitions presuppose well defined hypothetical interventions on the mediator. In many settings there may be multiple ways to fix the mediator to a particular value and these different hypothetical interventions may have very different implications for the outcome of interest. In this paper we cons...
Xu, Wen; Yuan, Jifeng; Yang, Shuiyun; Ching, Chi-Bun; Liu, Jiankang
Microbial synthesis of ubiquinone by fermentation processes has been emerging in recent years. However, as ubiquinone is a primary metabolite that is tightly regulated by the host central metabolism, tweaking the individual pathway components could only result in a marginal improvement on the ubiquinone production. Given that ubiquinone is stored in the lipid bilayer, we hypothesized that introducing additional metabolic sink for storing ubiquinone might improve the CoQ 10 production. As human lipid binding/transfer protein saposin B (hSapB) was reported to extract ubiquinone from the lipid bilayer and form the water-soluble complex, hSapB was chosen to build a compensatory metabolic sink for the ubiquinone storage. As a proof-of-concept, hSapB-mediated metabolic sink systems were devised and systematically investigated in the model organism of Escherichia coli. The hSapB-mediated periplasmic sink resulted in more than 200% improvement of CoQ 8 over the wild type strain. Further investigation revealed that hSapB-mediated sink systems could also improve the CoQ 10 production in a CoQ 10 -hyperproducing E. coli strain obtained by a modular pathway rewiring approach. As the design principles and the engineering strategies reported here are generalizable to other microbes, compensatory sink systems will be a method of significant interest to the synthetic biology community.
Wong, Jessie J; Gonzales, Nancy A; Montaño, Zorash; Dumka, Larry; Millsap, Roger E
Parental depression is a major risk factor in child development. Growing research suggests parenting programs can positively impact parental depressive symptoms, although the specific mechanisms that explain these effects are unknown. The current study examined parenting mediated effects of a parenting program on mothers' and fathers' depressive symptoms, as well as the role of child behavior in linking parenting to reductions in depressive symptoms. The study samples included 494 mothers and 288 fathers of Mexican origin adolescents who participated in a randomized trial of the Bridges to High School Program/Proyecto Puentes a la Secundaria, a universal prevention and promotion intervention that included parent training but did not directly target parental depressive symptoms. Parenting mediator models tested program effects on parental depressive symptoms through changes in harsh and supportive parenting. Results showed a significant indirect intervention effect on maternal depressive symptoms through changes in mothers' harsh parenting. Next, child behavior models revealed a partial mediation effect of harsh parenting and a full mediation effect of supportive parenting on maternal depressive symptoms through mothers' reports of child externalizing symptoms. Indirect effects of fathers' harsh and supportive parenting on paternal depressive symptoms were also found through fathers' reports of child behavior. PsycINFO Database Record (c) 2014 APA, all rights reserved.
Employee assistance programs have grown at a dramatic rate, yet the effectiveness of these programs has been called into question. The purpose of this paper was to assess the effectiveness of employee assistance programs (EAPs) by reviewing recently published EAP evaluations. All studies evaluating EAPs published since 1975 from peer-reviewed journals in the English language were included in this analysis. Each of the articles was assessed in the following areas: (a) program description (subj...
Riva, Valentina; Cantiani, Chiara; Dionne, Ginette; Marini, Andrea; Mascheretti, Sara; Molteni, Massimo; Marino, Cecilia
This study tested the role of temporary memory, measured by phonological short-term memory (pSTM) and verbal working memory (vWM), as a mediator of the effect of 3 putative risk factors (i.e., socioeconomic status, home literacy environment, birth gestational age) upon expressive and receptive language. A community-based sample of 646 Italian children aged 6-11 years was assessed with a comprehensive battery of language and cognitive tests. A mediation analysis was used to examine whether memory mediates environmental/biological effects on language. The results demonstrated a developmental cascade of effects, whereby the duration of pregnancy drives vWM functioning that, in turn, may affect expressive linguistic outcome Conclusion: Treatments focused on vWM, specifically to preterm children, may improve their language development, with enduring consequences on educational and psychosocial outcomes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Seo, Jin-Hee; Jeong, Eui-Suk; Choi, Yang-Kyu
Gastric cancer is the second most common cause of cancer-related death in males and the fourth in females. Traditional treatment has poor prognosis because of recurrence and systemic side effects. Therefore, the development of new therapeutic strategies is an important issue. Lentivirus-mediated shRNA stably inhibits target genes and can efficiently transduce most cells. Since overexpressed cyclin D1 is closely related to human gastric cancer progression, inhibition of cyclin D1 using specific targeting could be an effective treatment method of human gastric cancer. The therapeutic effect of lentivirus-mediated shRNA targeting of cyclin D1 (ShCCND1) was analyzed both in vitro and in vivo experiments. In vitro, NCI-N87 cells with downregulation of cyclin D1 by ShCCND1 showed significant inhibition of cell proliferation, cell motility, and clonogenicity. Downregulation of cyclin D1 in NCI-N87 cells also resulted in significantly increased G1 arrest and apoptosis. In vivo, stable NCI-N87 cells expressing ShCCND1 were engrafted into nude mice. Then, the cancer-growth inhibition effect of lentivirus was confirmed. To assess lentivirus including ShCCND1 as a therapeutic agent, intratumoral injection was conducted. Tumor growth of the lentivirus-treated group was significantly inhibited compared to growth of the control group. These results are in accordance with the in vitro data and lend support to the mitotic figure count and apoptosis analysis of the tumor mass. The lentivirus-mediated ShCCND1 was constructed, which effectively inhibited growth of NCI-N87-derived cancer both in vitro and in vivo. The efficiency of shRNA knockdown and variation in the degree of inhibition is mediated by different shRNA sequences and cancer cell lines. These experimental results suggest the possibility of developing new gastric cancer therapies using lentivirus-mediated shRNA
CHOI, Wan-Suk; KIM, Bo-Kyung; KIM, Ki-Do; MOON, Ok-Kon; YEUM, Dong-Moon
This study examined the impact of the number of painful stimuli on life satisfaction among workers who experienced an industrial accident and investigated how self-esteem and sleeping time affected life satisfaction. The Korea Workers’ Compensation & Welfare Service conducted the first nationwide panel survey on occupational health and safety insurance in 2013–2014 through a stratified systematic sampling on 2,000 industrial accident workers who completed convalescence. Based on the dataset, our study analyzed 1,832 workers experiencing an industrial accident after excluding 168 disease patients. For the research model analysis, a four-stage hierarchical regression analysis technique was applied using the SPSS regression analysis Macro program of PROCESS Procedure. To test mediated indirect effects of the self-esteem and sleeping time, the bootstrapping technique was applied. Life satisfaction, self-esteem and sleeping time decreased as the number of painful stimuli increased. Life satisfaction decreased as self-esteem and sleeping time decreased. On balance, the partial mediation model confirmed that self-esteem and sleeping time both mediate the impact of the number of painful stimuli on life satisfaction. PMID:27021061
Choi, Wan-Suk; Kim, Bo-Kyung; Kim, Ki-Do; Moon, Ok-Kon; Yeum, Dong-Moon
This study examined the impact of the number of painful stimuli on life satisfaction among workers who experienced an industrial accident and investigated how self-esteem and sleeping time affected life satisfaction. The Korea Workers' Compensation & Welfare Service conducted the first nationwide panel survey on occupational health and safety insurance in 2013-2014 through a stratified systematic sampling on 2,000 industrial accident workers who completed convalescence. Based on the dataset, our study analyzed 1,832 workers experiencing an industrial accident after excluding 168 disease patients. For the research model analysis, a four-stage hierarchical regression analysis technique was applied using the SPSS regression analysis Macro program of PROCESS Procedure. To test mediated indirect effects of the self-esteem and sleeping time, the bootstrapping technique was applied. Life satisfaction, self-esteem and sleeping time decreased as the number of painful stimuli increased. Life satisfaction decreased as self-esteem and sleeping time decreased. On balance, the partial mediation model confirmed that self-esteem and sleeping time both mediate the impact of the number of painful stimuli on life satisfaction.
Osberg, Timothy M; Billingsley, Katherine; Eggert, Meredith; Insana, Maribeth
Does exposure to college drinking movies impact upon subsequent college student drinking? If so, what mechanisms mediate such an effect? In the first study to address these questions, we assessed college drinking movie exposure in a sample of 479 college freshmen early in their first semester and examined its relation to subsequent drinking and drinking consequences one month later. Hypothesized mediators of this effect included college alcohol beliefs (beliefs that drinking is central to college life), positive and negative alcohol expectancies, and descriptive and injunctive norms. Using bootstrapping procedures, results indicated that movie exposure exerted direct effects on both drinking and drinking consequences. Movie exposure also had significant indirect effects on drinking through all of the hypothesized mediators, with the exception of negative alcohol expectancies. All mediated movie exposure's effects on drinking consequences, with the exception of injunctive norms. Contrast analyses revealed that college alcohol beliefs had the strongest mediational effects in the relationship between movie exposure and both drinking and consequences. The implications of these findings for precollege alcohol education programs are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.
Moisiadis, Vasilis G; Matthews, Stephen G
Fetal development is a critical period for shaping the lifelong health of an individual. However, the fetus is susceptible to internal and external stimuli that can lead to adverse long-term health consequences. Glucocorticoids are an important developmental switch, driving changes in gene regulation that are necessary for normal growth and maturation. The fetal hypothalamic-pituitary-adrenal (HPA) axis is particularly susceptible to long-term programming by glucocorticoids; these effects can persist throughout the life of an organism. Dysfunction of the HPA axis as a result of fetal programming has been associated with impaired brain growth, altered behaviour and increased susceptibility to chronic disease (such as metabolic and cardiovascular disease). Moreover, the effects of glucocorticoid-mediated programming are evident in subsequent generations, and transmission of these changes can occur through both maternal and paternal lineages.
VanderWeele, Tyler J
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.
Full Text Available Summary: Humoral immune responses are tailored to the invading pathogen through regulation of key transcription factors and their networks. This is critical to establishing effective antibody-mediated responses, yet it is unknown how B cells integrate pathogen-induced signals to drive or suppress transcriptional programs specialized for each class of pathogen. Here, we detail the key role of the transcription factor c-Myb in regulating the T-bet-mediated anti-viral program. Deletion of c-Myb in mature B cells significantly increased serum IgG2c and CXCR3 expression by upregulating T-bet, normally suppressed during Th2-cell-mediated responses. Enhanced expression of T-bet resulted in aberrant plasma cell differentiation within the germinal center, mediated by CXCR3 expression. These findings identify a dual role for c-Myb in limiting inappropriate effector responses while coordinating plasma cell differentiation with germinal center egress. Identifying such intrinsic regulators of specialized antibody responses can assist in vaccine design and therapeutic intervention in B-cell-mediated immune disorders. : Piovesan et al. examine how B cells establish transcriptional programs that result in tailored responses to invading pathogens. The authors find that the transcription factor c-Myb represses the T-bet-mediated anti-viral program in B cells. c-Myb limits inappropriate effector responses while coordinating plasma cell differentiation with germinal center egress. Keywords: B cells, c-Myb, T-bet, immunoglobulin, CXCR3, plasma cell, germinal center
Rose, Brigid M; Holmbeck, Grayson N; Coakley, Rachael Millstein; Franks, Elizabeth A
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.
Abdullah M. Alzahem
Full Text Available The dental education stress effects and sources were explored thoroughly in the literature, but the effectiveness of stress management programs received less attention. This study introduced a new stress management program, named Dental Education Stress Management (DESM program. It showed its effectiveness in a quasi-experimental pretest-posttest-follow-up-control group design. The new program was based on the principle of psychoeducation and consisted of three 90-min sessions, to teach dental students how to better deal with their stress symptoms and to reduce their general stress level. Two instruments were used to assess the level of stress of the dental students, namely the Dental Environment Stress questionnaire (DES, and the Psychological Stress Measure (PSM-9. Results show that the DESM program has the desired effect of decreasing the stress levels of its participants, and these effects lasted for at least two weeks. Because of several methodological limitations of the study more research is needed to draw more generalizable conclusions.
Sheng, Xiaotong; Yan, Jingmin; Meng, Yue; Kang, Yuying; Han, Zhen; Tai, Guihua; Zhou, Yifa; Cheng, Hairong
This study was aimed at investigating the immunomodulating activity of Hericium erinaceus polysaccharide (HEP) in mice, by assessing splenic lymphocyte proliferation (cell-mediated immunity), serum hemolysin levels (humoral immunity), phagocytic capacity of peritoneal cavity phagocytes (macrophage phagocytosis), and NK cell activity. ELISA of immunoglobulin A (SIgA) in the lamina propria, and western blotting of small intestinal proteins were also performed to gain insight into the mechanism by which HEP affects the intestinal immune system. Here, we report that HEP improves immune function by functionally enhancing cell-mediated and humoral immunity, macrophage phagocytosis, and NK cell activity. In addition, HEP was found to upregulate the secretion of SIgA and activate the MAPK and AKT cellular signaling pathways in the intestine. In conclusion, all these results allow us to postulate that the immunomodulatory effects of HEP are most likely attributed to the effective regulation of intestinal mucosal immune activity.
Jeong, Michelle; Tan, Andy; Brennan, Emily; Gibson, Laura; Hornik, Robert C.
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
Mambet Doue, Constance; Roussiau, Nicolas
This research investigates the indirect effects of religiosity (practice and belief) on therapeutic compliance in 81 HIV-positive patients who are migrants from sub-Saharan Africa (23 men and 58 women). Using analyses of mediation and standard multiple regression, including a resampling procedure by bootstrapping, the role of these mediators (magical-religious beliefs and nonuse of toxic substances) was tested. The results show that, through magical-religious beliefs, religiosity has a negative indirect effect, while with the nonuse of toxic substances, religious practice has a positive indirect effect. Beyond religiosity, the role of mediators is highlighted in the interaction with therapeutic compliance.
Full Text Available Background: It is unclear whether the relationship between cigarette smoking and atopy is mediated by body fat mass, such as the Body Mass Index (BMI. We assessed the mediating role of BMI on the relationship between smoking and atopy in Chinese adults. Methods: A hospital-based case-control study of 786 atopic cases and 2771 controls was conducted in adults aged 18 years or older from March 2010 to September 2014 in Harbin, China. Mediation models were used to estimate the indirect effects of smoking on atopic sensitization through BMI. Results: Compared to non-smokers, light smokers and moderate smokers had a lower risk of inhalant allergen sensitization. The indirect effect of smoking and sensitization to aeroallergens were only observed in light smokers (point estimate, −0.026; 95% CI, −0.062 to −0.004. The mediating roles of BMI on the relationships between smoking and other types of allergic sensitization were not statistically significant. Conclusion: BMI appeared to partially mediate the effect of light smoking on sensitization to aeroallergens. However, considering the other harmful health effects of cigarette smoking, the effective method to lower the incidence of atopy would be to decrease body fat mass by physical exercise and employing other more healthy ways of living rather than smoking.
Overbeek Mathilde M
Full Text Available Abstract Background Children who witness interparental violence are at a heightened risk for developing psychosocial, behavioral and cognitive problems, as well as posttraumatic stress symptoms. For these children the psycho-educational secondary prevention program 'En nu ik...!' ('It's my turn now!' has been developed. This program includes specific therapeutic factors focused on emotion awareness and expression, increasing feelings of emotional security, teaching specific coping strategies, developing a trauma narrative, improving parent-child interaction and psycho-education. The main study aim is to evaluate the effectiveness of the specific therapeutic factors in the program. A secondary objective is to study mediating and moderating factors. Methods/design This study is a prospective multicenter randomized controlled trial across cities in the Netherlands. Participants (N = 140 are referred to the secondary preventive intervention program by police, social work, women shelters and youth (mental health care. Children, aged 6-12 years, and their parents, who experienced interparental violence are randomly assigned to either the intervention program or the control program. The control program is comparable on nonspecific factors by offering positive attention, positive expectations, recreation, distraction, warmth and empathy of the therapist, and social support among group participants, in ways that are similar to the intervention program. Primary outcome measures are posttraumatic stress symptoms and emotional and behavioral problems of the child. Mediators tested are the ability to differentiate and express emotions, emotional security, coping strategies, feelings of guilt and parent-child interaction. Mental health of the parent, parenting stress, disturbances in parent-child attachment, duration and severity of the domestic violence and demographics are examined for their moderating effect. Data are collected one week before the program
Cavazza, Nicoletta; Serpe, Alessandra
Research on the role of organizational and psychosocial factors in influencing risk behaviors and the likelihood of injury at work showed that safety climate also has great impact on workers' behavior. However, the mechanisms through which this impact operates are still partially unclear. In order to explore the role that attitudinal ambivalence toward wearing PPE might play in mediating the impact of safety climate on safety norm violations, a questionnaire was administered to 345 Italian workers. Three dimensions of safety climate (i.e., company safety concern, senior managers' safety concern, supervisors' attitudes towards safety) were found to be positively associated with the individual ambivalence level, whereas the fourth one (i.e., work pressure) was negatively correlated with it. In turn, low levels of ambivalence were associated with a lower tendency to break the safety norms, even though the perception of a good safety climate also maintained a direct effect on unsafe behaviors. Designers of training program for the prevention of work related injuries must pay great attention to the psycho-social factors (such as the effects of the safety climate perception by employees on their attitudes and behaviors), and include specific contents into the prevention programs in order to improve workers compliance with safety norms.
Nieberding, Richard J
...). From the artifacts associated with this mentorship program, it appears that the Army highly values this program as a way to create a culture and climate that fosters learning and development for future leadership. This project will examine the effectiveness of mentorship in the today's Army and evaluate whether the program is sufficient to meet the needs for the Army's next generation of soldiers and leaders.
Leung, K.H.; Ehrke, M.J.; Bercsenyi, K.; Mihich, E.
The effect of human prealbumin fraction as allogeneic cell-mediated immunity in primary sensitization cultures of murine spleen cells was studied by 3H-thymidine uptake and specific 51Cr release assays. Prealbumin caused a dose-dependent augmentation of these responses. Human serum albumin, bovine serum albumin, and calf-thymosin fraction 5 had little effect. Prealbumin was active when added on day 0 or 1 but not thereafter. Prealbumin added to effector cells from immunized mice did not change their lytic activity. Prealbumin, but not human serum albumin or thymosin fraction 5, augmented secondary cell-mediated immunity in culture after primary immunization in mice. A slow growing mammary tumor line, which originated as a spontaneous mammary tumor in a DBA/2 HaDD breeder mouse, initially grows in 100% of DBA/2J mice but is then rejected in 10 to 20% of them. When prealbumin (59 microgram/day) was given subcutaneously for 2 weeks to DBA/2J mice and the tumor implanted 2 weeks later. 78% of the mice rejected the tumor and were then resistant to a rechallenge
Costa, Joana; Pinto-Gouveia, José
This study explores experiential avoidance as a mediator in the relationship between coping (rational coping, avoidant coping and detached/ emotional coping) and psychopathology (depression, anxiety and stress). A battery of self-report questionnaires was used to assess coping, experiential avoidance and depression, anxiety and stress in 70 participants with a chronic pain from Portuguese primary health care units. Regression analyses were performed and showed preliminary evidence supporting the mediation role of experiential avoidance in a Portuguese sample with chronic pain. Results show that experiential avoidance partially or fully mediate the effects of rational coping and detached/emotional coping on depression and stress. Implications for clinical practice were discussed and suggest that psychopathology is not necessary direct product of coping and other processes, such as experiential avoidance, are likely involved. Copyright © 2010 John Wiley & Sons, Ltd.
Wade, Tracey D; Wilksch, Simon M; Paxton, Susan J; Byrne, Susan M; Austin, S Bryn
The current study examined whether media internalization, found to mediate the relationship between selected prevention programs and outcomes, mediated the impact of two universal prevention programs that targeted risk factors for eating disorders and obesity, namely weight concern, and shape concern. Students randomized to a media literacy (Media Smart) program (N = 269, 65% females, mean age 12.97 years) and a healthy lifestyle (Life Smart) program (N = 347, 69% females, mean age 13.07 years) were included in the analyses. There were four waves of data (baseline, end of intervention, 6- and 12-month follow-up). Latent growth curve modeling was used to explore whether group assignment influenced levels of media internalization, and whether that in turn influenced change over time of our two outcome variables. Being randomly allocated to Media Smart as opposed to Life Smart resulted in less growth of both outcome variables through the influence on decreasing levels of media internalization. Findings provided support for the suggestion that media literacy programs exert an impact on outcomes related to eating disorder risk through changes to media internalization. Future research should examine whether these mechanisms of change differ between girls and boys. © 2017 Wiley Periodicals, Inc.
Chng, Grace S; Liau, Albert; Khoo, Angeline; Li, Dongdong
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.
Leenheer, J.; Bijmolt, T.H.A.; van Heerde, H.J.; Smidts, A.
This paper studies the effects of loyalty programs on share-of-wallet using market-wide household panel data on supermarket purchases.We find that loyalty programs relate positively to share-of-wallet, but the programs differ in effectiveness and some are ineffective.Both a saving component and a multi-vendor structure enhance the effectiveness of a loyalty program, but high discounts do not lead to higher share-of-wallets.Further, if households have multiple loyalty cards, the effectiveness ...
Painter, Julia E.; Sales, Jessica M.; Pazol, Karen; Wingood, Gina M.; Windle, Michael; Orenstein, Walter A.; DiClemente, Ralph J.
Background: School-based vaccination programs may provide an effective strategy to immunize adolescents against influenza. This study examined whether adolescent attitudes toward influenza vaccination mediated the relationship between receipt of a school-based influenza vaccination intervention and vaccine uptake. Methods: Participants were…
Full Text Available Even with identification of multiple causal genetic variants for common human diseases, understanding the molecular processes mediating the causal variants' effect on the disease remains a challenge. This understanding is crucial for the development of therapeutic strategies to prevent and treat disease. While static profiling of gene expression is primarily used to get insights into the biological bases of diseases, it makes differentiating the causative from the correlative effects difficult, as the dynamics of the underlying biological processes are not monitored. Using yeast as a model, we studied genome-wide gene expression dynamics in the presence of a causal variant as the sole genetic determinant, and performed allele-specific functional validation to delineate the causal effects of the genetic variant on the phenotype. Here, we characterized the precise genetic effects of a functional MKT1 allelic variant in sporulation efficiency variation. A mathematical model describing meiotic landmark events and conditional activation of MKT1 expression during sporulation specified an early meiotic role of this variant. By analyzing the early meiotic genome-wide transcriptional response, we demonstrate an MKT1-dependent role of novel modulators, namely, RTG1/3, regulators of mitochondrial retrograde signaling, and DAL82, regulator of nitrogen starvation, in additively effecting sporulation efficiency. In the presence of functional MKT1 allele, better respiration during early sporulation was observed, which was dependent on the mitochondrial retrograde regulator, RTG3. Furthermore, our approach showed that MKT1 contributes to sporulation independent of Puf3, an RNA-binding protein that steady-state transcription profiling studies have suggested to mediate MKT1-pleiotropic effects during mitotic growth. These results uncover interesting regulatory links between meiosis and mitochondrial retrograde signaling. In this study, we highlight the advantage
Full Text Available Geriatric depression is associated with the overall quality of life (QOL. However, how depressive symptoms affect the different domains and facets of QOL in older adults, and whether depressive symptoms mediate the relationship between physical disability and QOL in older adults are unclear.A total of 490 ambulatory community-dwelling older adults aged 65 years or above were interviewed using the brief version of the World Health Organisation Quality of Life instrument (WHOQOL-BREF, the Modified Barthel Index (MBI, the 15-item Geriatric Depression Scale (GDS-15, and the Mini-Mental State Examination (MMSE. Sequential models for multiple linear regressions were analysed to determine if the MBI, GDS-15 and MMSE scores predict the WHOQOL-BREF scores. The potential mediation effects of depression (as determined by the GDS-15 on the relationship between MBI and WHOQOL-BREF were also analysed.The GDS-15 score was predictive of the scores of the four domains and all 26 facets of the WHOQOL-BREF. The significant predictive effects of the MBI score on 15 of the 26 facets of the WHOQOL-BREF were reduced to three after the adjustment for the GDS-15 score. Depression (as assessed by the GDS-15 is a mediator of the relationship between MBI and the physical, psychological and environmental domains of the WHOQOL-BREF.Depression (assessed by the GDS-15 may affect the scores of every domain and all facets of the WHOQOL-BREF in the elderly. Furthermore, it may mediate the relationship between the MBI and on QOL scores. We recommend taking depressive symptoms into consideration when measuring community-dwelling older adults' QOL and providing active ageing programs.
Chen, Zewen; Wang, Lei; Ke, Jun; Xiao, DaLiao
Epidemiological studies and experimental studies have demonstrated that intrauterine adverse environment increases the risk of cardiovascular disease (CVD) in adulthood. However, whether an individual develops a cardiovascular dysfunctional phenotype may depend on genetic background, age, and sex. In this review, we summarize some of the recent experimental animal studies in the developmental programming of adult CVD with an emphasis on sex differences and the potential role of estrogen in mediating sexual dimorphism. Few epidemiological studies report the effect of sex on the developmental programming of CVD. However, numerous experimental animal studies have shown a sex difference in fetal programming of adult cardiovascular dysfunction. Most of the animal studies indicate that male offspring develop cardiovascular dysfunction and CVD in adulthood, whereas adult females appear to be protected. Estrogen is one of the key factors that contributes to the sex difference of adult CVD. Estrogen/its receptor (ER) may interact with the RAS system by changes of DNA methylation patterns at the target gene promoter, serve as an antioxidant to counteract the prenatal insults-induced heightened ROS, and function as an eNOS activator to increase vasodilation, resulting in the protection of female offspring from the development of hypertension and other CVDs. These studies suggest that estrogen/ER may contribute to sex differences in cardiovascular response to an adverse intrauterine environment and play a significant role in modulating the cardiovascular response in adulthood. Copyright© Bentham Science Publishers; For any queries, please email at firstname.lastname@example.org.
Chen, Nigel T M; Basanovic, Julian; Notebaert, Lies; MacLeod, Colin; Clarke, Patrick J F
Transcranial direct current stimulation (tDCS) is a neuromodulatory technique which has garnered recent interest in the potential treatment for emotion-based psychopathology. While accumulating evidence suggests that tDCS may attenuate emotional vulnerability, critically, little is known about underlying mechanisms of this effect. The present study sought to clarify this by examining the possibility that tDCS may affect emotional vulnerability via its capacity to modulate attentional bias towards threatening information. Fifty healthy participants were randomly assigned to receive either anodal tDCS (2 mA/min) stimulation to the left dorsolateral prefrontal cortex (DLPFC), or sham. Participants were then eye tracked during a dual-video stressor task designed to elicit emotional reactivity, while providing a concurrent in-vivo measure of attentional bias. Greater attentional bias towards threatening information was associated with greater emotional reactivity to the stressor task. Furthermore, the active tDCS group showed reduced attentional bias to threat, compared to the sham group. Importantly, attentional bias was found to statistically mediate the effect of tDCS on emotional reactivity, while no direct effect of tDCS on emotional reactivity was observed. The findings are consistent with the notion that the effect of tDCS on emotional vulnerability may be mediated by changes in attentional bias, holding implications for the application of tDCS in emotion-based psychopathology. The findings also highlight the utility of in-vivo eye tracking measures in the examination of the mechanisms associated with DLPFC neuromodulation in emotional vulnerability. Copyright © 2017 Elsevier Ltd. All rights reserved.
MacKinnon, David P.; Fairchild, Amanda J.
Mediating variables continue to play an important role in psychological theory and research. A mediating variable transmits the effect of an antecedent variable on to a dependent variable, thereby providing more detailed understanding of relations among variables. Methods to assess mediation have been an active area of research for the last two decades. This paper describes the current state of methods to investigate mediating variables. PMID:20157637
MacKinnon, David P.; Fairchild, Amanda J.
Mediating variables continue to play an important role in psychological theory and research. A mediating variable transmits the effect of an antecedent variable on to a dependent variable, thereby providing more detailed understanding of relations among variables. Methods to assess mediation have been an active area of research for the last two decades. This paper describes the current state of methods to investigate mediating variables.
Kuo, Huai-Ting; Lin, Kuan-Chia; Li, I-Chuan
This study explores the mediating effects of job satisfaction on work stress and turnover intention among long-term care nurses in Taiwan. Healthcare institutions face a nursing shortage, and it is important to examine the factors that influence turnover intention among nurses. Excessive levels of work stress may lead to employee dissatisfaction and a significant inverse relationship between work stress and job satisfaction, including subsequent effects on turnover among nurses. However, little is known about the mediating role of job satisfaction on work stress and turnover intention among long-term care nurses. A cross-sectional survey and a correlation design were used. Multistage linear regression was used to test the mediation model. This study showed that job satisfaction significantly mediated the relationship between work stress and turnover intention. Thirty-eight percent of the variance in turnover intention explained by work stress was accounted for by the mediation pathway. The results of this study showed that higher job satisfaction significantly decreased work stress and turnover intention among long-term care nurses. This study provides nursing administrators with a resource to build a supportive environment to increase nurses' job satisfaction and to decrease their stress and turnover. © 2013 John Wiley & Sons Ltd.
Qin, Peng; Xu, Lin; Zhong, Wenjing; Yu, Alfred C H
The interaction between ultrasound pulses and microbubbles is known to generate acoustic cavitation that may puncture biological cells. This work presents new experimental findings on the bioeffects of ultrasound-microbubble mediated cavitation in plant cells with emphasis on direct observations of morphological impact and analysis of viability trends in tobacco BY-2 cells that are widely studied in higher plant physiology. The tobacco cell suspensions were exposed to 1 MHz ultrasound pulses in the presence of 1% v/v microbubbles (10% duty cycle; 1 kHz pulse repetition frequency; 70 mm between probe and cells; 1-min exposure time). Few bioeffects were observed at low peak negative pressures (cavitation presumably occurred. In contrast, at 0.9 MPa peak negative pressure (with more inertial cavitation activities according to our passive cavitation detection results), random pores were found on tobacco cell wall (observed via scanning electron microscopy) and enhanced exogenous uptake into the cytoplasm was evident (noted in our fluorescein isothiocyanate dextran uptake analysis). Also, instant lysis was observed in 23.4% of cells (found using trypan blue staining) and programmed cell death was seen in 23.3% of population after 12 h (determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling [TUNEL]). These bioeffects generally correspond in trend with those for mammalian cells. This raises the possibility of developing ultrasound-microbubble mediated cavitation into a targeted gene transfection paradigm for plant cells and, conversely, adopting plant cells as experimental test-beds for sonoporation-based gene therapy in mammalian cells. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.
Hamilton, Kristen R; Ansell, Emily B; Reynolds, Brady; Potenza, Marc N; Sinha, Rajita
Stress and impulsivity contribute to alcohol use, and stress may also act via impulsivity to increase drinking behavior. Impulsivity represents a multi-faceted construct and self-report and behavioral assessments may effectively capture distinct clinically relevant factors. The present research investigated whether aspects of impulsivity mediate the effect of stress on alcohol use. A community-based sample of 192 men and women was assessed on measures of cumulative stress, alcohol use, self-reported impulsivity, and behavioral choice and response impulsivity. Data were analyzed using regression and bootstrapping techniques to estimate indirect effects of stress on drinking via impulsivity. Cumulative adversity exhibited both direct effects and indirect effects (via self-reported impulsivity) on drinking behavior. Additional models examining specific types of stress indicated direct and indirect effects of trauma and recent life events, and indirect effects of major life events and chronic stressors on drinking behavior. Overall, cumulative stress was associated with increased drinking behavior, and this effect was partially mediated by self-reported impulsivity. Self-reported impulsivity also mediated the effects of different types of stress on drinking behavior. These findings highlight the value of mediation models to examine the pathways through which different types of stress increase drinking behavior. Treatment and prevention strategies should focus on enhancing stress management and self-control.
Barrick, Murray R; Stewart, Greg L; Piotrowski, Mike
Research shows consistent relations between personality and job performance. In this study the authors develop and test a model of job performance that examines the mediating effects of cognitive-motivational work orientations on the relationships between personality traits and performance in a sales job (N = 164). Covariance structural analyses revealed proximal motivational variables to be influential mechanisms through which distal personality traits affect job performance. Specifically, striving for status and accomplishment mediate the effects of Extraversion and Conscientiousness on ratings of sales performance. Although Agreeableness was related to striving for communion, neither Agreeableness nor communion striving was related to success in this sales job. The importance of the proposed motivational orientations model is discussed.
Sang Back Nam
Full Text Available The purpose of the current study was to investigate the influence of Paralympic sponsorship on corporate image and consumer purchase intension, and the mediating role of corporate image between sponsorship and purchase intention was examined. Furthermore, it was to investigate which dimension of corporate image plays as the mediating role in the relationship between Paralympic sponsorship and consumer purchase intention. 400 data were collected from residents of Seoul, Incheon, Busan, and Kwangju, Korea from December 20th, 2010 to January 10th, and 384 data were used. The data were analyzed by using SPSS/PC ver. 15.0 for Windows and AMOS 7.0 program. The mediating effects were tested by using Bootrapping method. The significance level was set at á = .05, and the results are as follows. First, promotion and contribution dimensions of Paralympic sponsorship had positive effects on corporate image. Second, Paralympic sponsorship had positive effects on consumers' purchase intention. Third, among corporate image dimensions, only corporate contribution image had positive effects on consumers' purchase intention. Fourth, corporate contribution dimension was partially mediating in the relationship between promotion dimension of Paralympic sponsorship and consumers' purchase intention and contribution dimension of Paralympic sponsorship and consumers'purchase intention.
Granero, Roser; Louwaars, Leonie; Ezpeleta, Lourdes
To investigate the mediating mechanisms of oppositional defiant disorder (ODD) in preschoolers through pathways analysis, considering the family socioeconomic status (SES) as the independent variable and the parenting style and the children's executive functioning (EF) as the mediating factors. The sample included 622 three-year-old children from the general population. Multi-informant reports from parents and teachers were analyzed. Structural Equation Modeling showed that the associations between SES, EF, parenting style and ODD levels differed by children's gender: (a) for girls, the association of low SES and high ODD scores was partially mediated by difficulties in EF inhibition, and parenting practices defined by corporal punishment and inconsistent discipline obtained a quasi-significant indirect effect into the association between SES and ODD; (b) for boys, SES and EF (inhibition and emotional control) had a direct effect on ODD with no mediation. SES seems a good indicator to identify children at high-risk for prevention and intervention programs for ODD. Girls with ODD in families of low SES may particularly benefit from parent training practices and training in inhibition control.
Carson, Valerie; Salmon, Jo; Arundell, Lauren; Ridgers, Nicola D; Cerin, Ester; Brown, Helen; Hesketh, Kylie D; Ball, Kylie; Chinapaw, Mai; Yildirim, Mine; Daly, Robin M; Dunstan, David W; Crawford, David
The optimal targets and strategies for effectively reducing sedentary behavior among young people are unknown. Intervention research that explores changes in mediated effects as well as in outcome behaviors is needed to help inform more effective interventions. Therefore, the purpose of this study was to examine the mid-intervention mediating effects on children's objectively assessed classroom and total weekday sedentary time in the Transform-Us! intervention. The results are based on 293 children, aged 7- to 9-years-old at baseline, from 20 schools in Melbourne, Australia. Each school was randomly allocated to one of four groups, which targeted reducing sedentary time in the school and family settings (SB; n = 74), increasing or maintaining moderate- to vigorous-intensity physical activity in the school and family settings (PA; n = 75), combined SB and PA (SB + PA; n = 80), or the current practice control (C; n = 64). Baseline and mid-intervention data (5-9 months) were collected in 2010 and analyzed in 2012. Classroom and total weekday sedentary time was objectively assessed using ActiGraph accelerometers. The hypothesized mediators including, child enjoyment, parent and teacher outcome expectancies, and child perceived access to standing opportunities in the classroom environment, were assessed by questionnaire. The SB + PA group spent 13.3 min/day less in weekday sedentary time at mid-intervention compared to the control group. At mid-intervention, children in the SB group had higher enjoyment of standing in class (0.9 units; 5-unit scale) and all intervention groups had more positive perceptions of access to standing opportunities in the classroom environment (0.3-0.4 units; 3-unit scale), compared to the control group. However, none of the hypothesized mediator variables had an effect on sedentary time; thus, no mediating effects were observed. While beneficial intervention effects were observed on some hypothesized mediating
Wongpakaran, Tinakon; Wongpakaran, Nahathai; Tanchakvaranont, Sitthinant; Bookkamana, Putipong; Pinyopornpanish, Manee; Wannarit, Kamonporn; Satthapisit, Sirina; Nakawiro, Daochompu; Hiranyatheb, Thanita; Thongpibul, Kulvadee
Despite the fact that pain is related to depression, few studies have been conducted to investigate the variables that mediate between the two conditions. In this study, the authors explored the following mediators: cognitive function, self-sacrificing interpersonal problems, and perception of stress, and the effects they had on pain symptoms among patients with depressive disorders. An analysis was performed on the data of 346 participants with unipolar depressive disorders. The 17-item Hamilton Depression Rating Scale, Mini-Mental State Examination, the pain subscale of the health-related quality of life (SF-36), the self-sacrificing subscale of the Inventory of Interpersonal Problems, and the Perceived Stress Scale were used. Parallel multiple mediator and serial multiple mediator models were used. An alternative model regarding the effect of self-sacrificing on pain was also proposed. Perceived stress, self-sacrificing interpersonal style, and cognitive function were found to significantly mediate the relationship between depression and pain, while controlling for demographic variables. The total effect of depression on pain was significant. This model, with an additional three mediators, accounted for 15% of the explained variance in pain compared to 9% without mediators. For the alternative model, after controlling for the mediators, a nonsignificant total direct effect level of self-sacrificing was found, suggesting that the effect of self-sacrificing on pain was based only on an indirect effect and that perceived stress was found to be the strongest mediator. Serial mediation may help us to see how depression and pain are linked and what the fundamental mediators are in the chain. No significant, indirect effect of self-sacrificing on pain was observed, if perceived stress was not part of the depression and/or cognitive function mediational chain. The results shown here have implications for future research, both in terms of testing the model and in
Kretschmer, Veronika; Schmidt, Klaus-Helmut; Griefahn, Barbara
The present study examined whether the relationship between light exposure and cognitive functioning is mediated by psychological well-being in elderly persons working night shifts. The role of psychological well-being has been neglected so far in the relationship between bright light and cognitive performance. Sleepiness and mood were applied as indicators of psychological well-being. Cognitive functioning was examined in terms of concentration, working memory, and divided attention. A total of thirty-two test persons worked in three consecutive simulated night shifts, 16 under bright light (3,000 lux) and 16 under room light (300 lux). Concentration, working memory, and divided attention were measured by computerised tasks. The hypothesised mediators were recorded by questionnaires. Mediation analyses were conducted for estimating direct, total, and indirect effects in simple mediation models. Results indicate that sleepiness and mood did not function as mediators in the prediction of concentration, working memory, and/or divided attention by light exposure. Sleepiness led to an underestimation of the positive bright-light effect on concentration performance. Mood showed only a random effect due to the positive bright-light effect on working memory. Sleepiness and mood could completely be excluded as mediators in the relationship between light exposure and cognitive functioning. This study underlines that psychological well-being of elderly persons is not a critical component in the treatment of bright light on cognitive performance in the night shift workplace. In summary, it becomes evident that bright light has a strong direct and independent effect on cognitive performance, particularly on working memory and concentration.
Song, Ji Hoon; Kolb, Judith A.; Lee, Ung Hee; Kim, Hye Kyoung
Engagement as an area of increasing interest has been discussed in terms of a wide array of organizational policies, practices, and outcomes. This study focuses on a specific aspect of work engagement and its relationship with leadership practices and the outcome of knowledge creation. The mediating effect of employees' work engagement level was…
Kitko, Kristina E; Hong, Tu; Lazarenko, Roman M; Ying, Da; Xu, Ya-Qiong; Zhang, Qi
Graphene possesses extraordinary properties that promise great potential in biomedicine. However, fully leveraging these properties requires close contact with the cell surface, raising the concern of unexpected biological consequences. Computational models have demonstrated that graphene preferentially interacts with cholesterol, a multifunctional lipid unique to eukaryotic membranes. Here we demonstrate an interaction between graphene and cholesterol. We find that graphene increases cell membrane cholesterol and potentiates neurotransmission, which is mediated by increases in the number, release probability, and recycling rate of synaptic vesicles. In fibroblasts grown on graphene, we also find an increase in cholesterol, which promotes the activation of P2Y receptors, a family of receptor regulated by cholesterol. In both cases, direct manipulation of cholesterol levels elucidates that a graphene-induced cholesterol increase underlies the observed potentiation of each cell signaling pathway. These findings identify cholesterol as a mediator of graphene's cellular effects, providing insight into the biological impact of graphene.
Bilstad, Julie Brat
This study is a response to the research and request presented by Bang and Midelfart (2010), to further investigate the effect dialogue can have on management team s effectiveness. The purpose of the study was to investigate and explain the effect of team psychological safety on task performance and team member satisfaction, with dialogue as a mediator in this relationship. 215 Norwegian and Danish management teams in the private and public sector were studied. As expected, team psychological...
Tak Yuli R
Full Text Available Abstract Background The incidence of depressive symptoms increases during adolescence, from 10.0% to 24.5% at age 11 to 15, respectively. Experiencing elevated levels of depressive symptoms increases the risk of a depressive disorder in adulthood. A universal school-based depression prevention program Op Volle Kracht (OVK was developed, based on the Penn Resiliency Program, aimed at preventing the increase of depressive symptoms during adolescence and enhancing positive development. In this study the effectiveness of OVK will be tested and possible mediators of program effects will be focus of study as well. Method The effectiveness of OVK will be tested in a randomized controlled trial with two conditions, intervention (OVK and control condition (care as usual. Schools are randomly assigned to research conditions. OVK will be incorporated in the school curriculum, maximizing program attendance. OVK consists of 16 lessons of 50 min, given by trained psychologists to groups of 11-15 students. OVK contains Cognitive Behavioral Therapy, social skills training, problem solving and decision making. Outcomes are measured at 6, 12, 18 and 24 months follow up, to monitor long term program effects. Primary outcome is level of depressive symptoms, secondary outcomes are: anxiety, hopelessness, cognitive bias, substance use, truancy, life satisfaction, coping, self-efficacy, optimism, happiness, friendship, school performance and school attitude. The questionnaires for students will be administered in the school setting. Parents will complete a questionnaire at baseline only. Discussion In this paper the study into the effectiveness of the depression prevention program OVK was described. It is expected that OVK will prevent the increase in depressive symptoms during adolescence and enhance positive development in the intervention condition, compared to the control condition. If OVK will be effective, it can be implemented in the school context by which
Tak, Yuli R; Van Zundert, Rinka Mp; Kuijpers, Rowella Cwm; Van Vlokhoven, Boukje S; Rensink, Hettie Fw; Engels, Rutger Cme
The incidence of depressive symptoms increases during adolescence, from 10.0% to 24.5% at age 11 to 15, respectively. Experiencing elevated levels of depressive symptoms increases the risk of a depressive disorder in adulthood. A universal school-based depression prevention program Op Volle Kracht (OVK) was developed, based on the Penn Resiliency Program, aimed at preventing the increase of depressive symptoms during adolescence and enhancing positive development. In this study the effectiveness of OVK will be tested and possible mediators of program effects will be focus of study as well. The effectiveness of OVK will be tested in a randomized controlled trial with two conditions, intervention (OVK) and control condition (care as usual). Schools are randomly assigned to research conditions. OVK will be incorporated in the school curriculum, maximizing program attendance. OVK consists of 16 lessons of 50 min, given by trained psychologists to groups of 11-15 students. OVK contains Cognitive Behavioral Therapy, social skills training, problem solving and decision making. Outcomes are measured at 6, 12, 18 and 24 months follow up, to monitor long term program effects. Primary outcome is level of depressive symptoms, secondary outcomes are: anxiety, hopelessness, cognitive bias, substance use, truancy, life satisfaction, coping, self-efficacy, optimism, happiness, friendship, school performance and school attitude. The questionnaires for students will be administered in the school setting. Parents will complete a questionnaire at baseline only. In this paper the study into the effectiveness of the depression prevention program OVK was described. It is expected that OVK will prevent the increase in depressive symptoms during adolescence and enhance positive development in the intervention condition, compared to the control condition. If OVK will be effective, it can be implemented in the school context by which numerous adolescents can be reached. Netherlands Trial
Varni, James W; Shulman, Robert J; Self, Mariella M; Saeed, Shehzad A; Zacur, George M; Patel, Ashish S; Nurko, Samuel; Neigut, Deborah A; Franciosi, James P; Saps, Miguel; Denham, Jolanda M; Dark, Chelsea Vaughan; Bendo, Cristiane B; Pohl, John F
The primary objective was to investigate the mediating effects of patient-perceived medication adherence barriers in the relationship between gastrointestinal symptoms and generic health-related quality of life (HRQOL) in adolescents with inflammatory bowel disease (IBD). The secondary objective explored patient health communication and gastrointestinal worry as additional mediators with medication adherence barriers in a serial multiple mediator model. The Pediatric Quality of Life Inventory™ Gastrointestinal Symptoms, Medicines, Communication, Gastrointestinal Worry, and Generic Core Scales were completed in a 9-site study by 172 adolescents with IBD. Gastrointestinal Symptoms Scales measuring stomach pain, constipation, or diarrhea and perceived medication adherence barriers were tested for bivariate and multivariate linear associations with HRQOL. Mediational analyses were conducted to test the hypothesized mediating effects of perceived medication adherence barriers as an intervening variable between gastrointestinal symptoms and HRQOL. The predictive effects of gastrointestinal symptoms on HRQOL were mediated in part by perceived medication adherence barriers. Patient health communication was a significant additional mediator. In predictive analytics models utilizing multiple regression analyses, demographic variables, gastrointestinal symptoms (stomach pain, constipation, or diarrhea), and perceived medication adherence barriers significantly accounted for 45, 38, and 29 percent of the variance in HRQOL (all Ps barriers explain in part the effects of gastrointestinal symptoms on HRQOL in adolescents with IBD. Patient health communication to healthcare providers and significant others further explain the mechanism in the relationship between gastrointestinal symptoms, perceived medication adherence barriers, and HRQOL.
Ricotta, Emily E; Boulay, Marc; Ainslie, Robert; Babalola, Stella; Fotheringham, Megan; Koenker, Hannah; Lynch, Matthew
SBCC campaigns are designed to act on cognitive, social and emotional factors at the individual or community level. The combination of these factors, referred to as 'ideation', play a role in determining behaviour by reinforcing and confirming decisions about a particular health topic. This study introduces ideation theory and mediation analysis as a way to evaluate the impact of a malaria SBCC campaign in Tanzania, to determine whether exposure to a communication programme influenced universal coverage through mediating ideational variables. A household survey in three districts where community change agents (CCAs) were active was conducted to collect information on ITN use, number of ITNs in the household, and perceptions about ITN use and ownership. Variables relating to attitudes and beliefs were combined to make 'net ideation'. Using an ideational framework, a mediation analysis was conducted to see the impact exposure to a CCA only, mass media and community (M & C) messaging only, or exposure to both, had on household universal coverage, through the mediating variable net ideation. All three levels of exposure (CCA, M & C messaging, or exposure to both) were significantly associated with increased net ideation (CCA: 0.283, 95% CI: 0.136-0.429, p-value: mediation analysis is an applicable new tool to assess SBCC campaigns. Ideation as a mediator of the effects of communication exposure on household universal coverage has implications for designing SBCC to support both mass and continuous distribution efforts, since both heavily rely on consumer participation to obtain and maintain ITNs. Such systems can be strengthened by SBCC programming, generating demand through improving social norms about net ownership and use, perceived benefits of nets, and other behavioural constructs.
Kim, EunYoung; Cho, Inhyo; Kim, Eun Joo
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.
Jia, Xuji; Liu, Xia
Using cross-sectional data from rural-to-urban migrant adolescents in urban areas of Beijing, China, we examined the mediating effects of social support (i.e. teacher support and classmate support) in the relationship between perceived discrimination (PD) and antisocial behaviour (ASB) among Chinese migrant adolescents. Participants were 897 adolescents (459 boys and 438 girls, mean age = 13.34 years) from four migrant schools (68.8%) and four public schools (31.2%). Participants completed self-report questionnaires concerning PD, ASB, teacher support and classmate support. Results indicated that Chinese migrant adolescents who perceived more discrimination were more likely to engage in ASB. Teacher support partially mediated the relationship between PD and ASB. Gender moderated this mediational relationship, such that teacher support exerted a mediating role among girls, but not boys. The findings suggest that reductions in teacher support may partially account for the effect of PD on ASB among Chinese migrant adolescents girls. © 2016 International Union of Psychological Science.
Shania Dwi Rantika
Full Text Available Leaders who promote ethical behavior are believed to affect their employees’ well-being. This study was conducted to examine psychological empowerment as the intervening variable that connects ethical leadership to employees’ well-being, work engagement, and emotional exhaustion. By using a mail survey, we distributed questionnaires to 219 auditors from 11 public accounting firms in Jakarta. All the hypotheses in this study were supported. Ethical leadership has a positive effect on psychological empowerment. Thus, psychological empowerment positively relates to work engagement and negatively relates to emotional exhaustion. The result demonstrated that psychological empowerment partially mediates the effect of ethical leadership on work engagement and fully mediates the effect on ethical leadership and emotional exhaustion. The findings reveal that ethical leadership stimulates the psychological empowerment of the employee, thus, it enhances work engagement and also minimizes emotional exhaustion.
Full Text Available The mediation activity as an alternative way of solving conflicts occupies an important place in modernsociety. Currently, the mediation reached its maturity worldwide being adopted without reservations.The future of solving conflicts is undoubtedly closely related to mediation. XXth century is the century of solvingconflicts amiably outside the court room. In Romania and the mediation profession were regulated by the Law no.192/2006, on the basis of the idea that mediation is one of the major themes of the reform strategy of the judicialsystem 2005-2007. By adopting the mentioned law it was followed the idea of reducing the volume of activitycourts, and therefore, relieve them of as many cases, with the direct effect on the quality of justice. Mediation is avoluntary process in which the parties with a neutral and impartial third party, without power of decision - themediator - who is qualified to assist the parties to negotiate, facilitating the communication between them andhelping them to reach a unanimous effective and sustainable agreement. The parties may resort to mediation beforeor after triggering a trial. Mediation can be applied, in principle, on any type of conflict. However, theRomanian legislator has established special stipulations on conflict mediation in criminal, civil and familylaw. Although not expressly provided, the stipulations regarding the civil conflicts and also apply to commercialconflicts. Therefore, the mediation is applicable to most types of lawsuits, except those relating to personalrights. As a "win- win" principle, the mediation does not convert any of the parties defeated or victorious; allthose involved have gained by applying this procedure.
in the mediated transparent society. The paper concludes that, based on these analyses, the mediated panopticism working on the business segment is not an effective disciplinary apparatus, which can guarantee that business corporations are carrying out important ecological or ethical improvements....
Ryan, W.; Scott, O.; Lori, B.; Blair, S.
Utility green pricing programs represent one way in which consumers can voluntarily support the development of renewable energy. The design features and effectiveness of these programs varies considerably. Based on a survey of utility program managers in the United States, this article provides insight into which program features might help maximize both customer participation in green pricing programs and the amount of renewable energy purchased by customers in those programs. We find that program length has a substantial impact on customer participation and purchases; to achieve higher levels of success, utilities will need to remain committed to their product offering for some time. Our findings also suggest that utilities should consider higher renewable energy purchase thresholds for residential customers in order to maximize renewable energy sales. Smaller utilities are found to be more successful than larger utilities, and we find some evidence that providing private benefits to nonresidential participants can enhance success. Interestingly, we find little evidence that the cost of the green pricing product greatly impacts customer participation and renewable energy sales, at least over the narrow range of premiums embedded in our data set, and for the initial set of green power purchasers. (author)
Madon, Stephanie; Guyll, Max; Buller, Ashley A; Scherr, Kyle C; Willard, Jennifer; Spoth, Richard
This research examined whether self-fulfilling prophecy effects are mediated by self-verification, informational conformity, and modeling processes. The authors examined these mediational processes across multiple time frames with longitudinal data obtained from two samples of mother-child dyads (N-sub-1 = 486; N-sub-2 = 287), with children's alcohol use as the outcome variable. The results provided consistent support for the mediational process of self-verification. In both samples and across several years of adolescence, there was a significant indirect effect of mothers' beliefs on children's alcohol use through children's self-assessed likelihood of drinking alcohol in the future. Comparatively less support was found for informational conformity and modeling processes as mediators of mothers' self-fulfilling effects. The potential for self-fulfilling prophecies to produce long-lasting changes in targets' behavior via self-verification processes are discussed. (c) 2008 APA, all rights reserved
Mustillo, Sarah A.; Dorsey, Shannon; Conover, Kate; Burns, Barbara J.
Using longitudinal data on 1,813 children and parents from a nationally representative child-welfare sample, National Survey of Child and Adolescent Well-Being (NSCAW), this study investigated physically abusive and neglectful parenting as mediating the effects of parent depression on child mental health by developmental stage. Findings from…
Brawley Lawrence R
Full Text Available Abstract Background When examining the prevalence of physical inactivity by gender and age, women over the age of 25 are at an increased risk for sedentary behavior. Childbearing and motherhood have been explored as one possible explanation for this increased risk. Post natal exercise studies to date demonstrate promising physical and psychological outcomes, however few physical activity interventions have been theory-driven and tailored to post natal exercise initiates. The purpose of this study was to compare the effects of a group-mediated cognitive behavioral intervention based upon social-cognitive theory and group dynamics (GMCB to a standard care postnatal exercise program (SE. Method A randomized, two-arm intervention design was used. Fifty-seven post natal women were randomized to one of two conditions: (1 a standard exercise treatment (SE and (2 a standard exercise treatment plus group-mediated cognitive behavioral intervention (GMCB. Participants in both conditions participated in a four-week intensive phase where participants received standard exercise training. In addition, GMCB participants received self-regulatory behavioral skills training via six group-mediated counseling sessions. Following the intensive phase, participants engaged in a four-week home-based phase of self-structured exercise. Measures of physical activity, barrier efficacy, and proximal outcome expectations were administered and data were analyzed using ANCOVA procedures. Results and discussion ANCOVA of change scores for frequency, minutes, and volume of physical activity revealed significant treatment effects over the intensive and home-based phases (p's Conclusion While both exercise programs resulted in improvements to exercise participation, the GMCB intervention produced greater improvement in overall physical activity, barrier efficacy and proximal outcome expectations.
Stephanie Baird Wilkerson, PhD Carol Haden EdD Magnolia Consulting,LLC Education and public outreach (EPO) program developers and providers seeking insights regarding effective practices for evaluating EPO activities programs benefit from understanding why evaluation is critical to the success of EPO activities and programs, what data collection methods are appropriate, and how to effectively communicate and report findings. Based on our extensive experience evaluating EPO programs, we will share lessons learned and examples of how these practices play out in actual evaluation studies. EPO program developers, providers, and evaluators must consider several factors that influence which evaluation designs and data collection methods will be most appropriate, given the nature of EPO programs. Effective evaluation practices of EPO programs take into account a program's phase of development, duration, and budget as well as a program's intended outcomes. EPO programs that are just beginning development will have different evaluation needs and priorities than will well-established programs. Effective evaluation practices consider the 'life' of a program with an evaluation design that supports a program's growth through various phases including development, revision and refinement, and completion. It would be premature and inappropriate to expect the attainment of longer-term outcomes of activities during program development phases or early stages of implementation. During program development, EPO providers should clearly define program outcomes that are feasible and appropriate given a program's scope and expected reach. In many respects, this directly relates to the amount of time, or duration, intended audiences participate in EPO programs. As program duration increases so does the likelihood that the program can achieve longer-term outcomes. When choosing which outcomes are reasonable to impact and measure, program duration should be considered. Effective evaluation
Colombo, Stefano; Brisander, Magnus; Haglöf, Jakob
Factors determining the pH-controlled dissolution kinetics of nilotinib formulations with the pH-titrable polymer hydroxypropyl methylcellulose phthalate, obtained by carbon dioxide-mediated precipitation, were mechanistically examined in acid and neutral environment. The matrix effect, modulating...... in the polymer matrix were mediated by hydrogen bonding between the drug and the phthalate groups on the polymer. Simultaneous Raman and UV-imaging studies of the effect of drug load on the swelling and dissolution of the polymer matrix revealed that high nilotinib load prevented matrix swelling on passage from...
Wang, Aolin; Arah, Onyebuchi A.
Recent work has considerably advanced the definition, identification and estimation of controlled direct, and natural direct and indirect effects in causal mediation analysis. Despite the various estimation methods and statistical routines being developed, a unified approach for effect estimation under different effect decomposition scenarios is still needed for epidemiologic research. G-computation offers such unification and has been used for total effect and joint controlled direct effect estimation settings, involving different types of exposure and outcome variables. In this study, we demonstrate the utility of parametric g-computation in estimating various components of the total effect, including (1) natural direct and indirect effects, (2) standard and stochastic controlled direct effects, and (3) reference and mediated interaction effects, using Monte Carlo simulations in standard statistical software. For each study subject, we estimated their nested potential outcomes corresponding to the (mediated) effects of an intervention on the exposure wherein the mediator was allowed to attain the value it would have under a possible counterfactual exposure intervention, under a pre-specified distribution of the mediator independent of any causes, or under a fixed controlled value. A final regression of the potential outcome on the exposure intervention variable was used to compute point estimates and bootstrap was used to obtain confidence intervals. Through contrasting different potential outcomes, this analytical framework provides an intuitive way of estimating effects under the recently introduced 3- and 4-way effect decomposition. This framework can be extended to complex multivariable and longitudinal mediation settings
Ju, Soyoung; Lee, Yanghee
The purpose of this study is to identify the developmental trajectories of peer attachment, self-esteem, depression, and child maltreatment, and to understand the longitudinal mediation effects that peer attachment and self-esteem have on the influence of perceived abuse on early adolescent depression. This study uses Year 1 to Year 5 data of the 4th grader panel of the Korea Youth Panel Survey (KYPS) and utilizes a multivariate latent growth model to analyze the main variables in the applicable data between 5th (i.e., Year 2) and 8th (i.e., Year 5) grades. The results indicate that from the 5th to the 8th grade, the degree of abuse and depression increases while self-esteem gradually decreases with slowly lowering peer attachment. A significant distribution of the initial values and the rate of change were present for all main variables of the study, confirming individual differences in time wise changes. Further, more exposure to abuse correlated with a decrease in self-esteem, while an increase in self-esteem greatly reduced depression. The initial value of self-esteem showed a partial mediation effect, whereas the rate of change indicated a full mediation effect with a significant longitudinal mediation effect. More experience of abuse during early adolescence indicated a lower degree of peer attachment, and a higher peer attachment was related to decreased depression. A significant partial mediation effect was present for both the initial value and the rate of change of peer attachment, and a longitudinal mediation effect was present. This study confirmed that self-esteem in early adolescents is an important protective factor that can greatly reduce the degree of depression, and suggests continuous interventions conducted to increase self-esteem in adolescence. Furthermore, by determining that peer attachment decreases the degree of depression in children at risk, the study emphasizes the healing aspect of adolescent peer attachment. Copyright © 2017 Elsevier
Shoraka, Ali R; Otzel, Dana M; M Zilli, Eduardo; Finney, Glen R; Doty, Leilani; Falchook, Adam D; Heilman, Kenneth M
Action-intentional programs control "when" we initiate, inhibit, continue, and stop motor actions. The purpose of this study was to learn if there are changes in the action-intentional system with healthy aging, and if these changes are asymmetrical (right versus left upper limb) or related to impaired interhemispheric communication. We administered tests of action-intention to 41 middle-aged and older adults (61.9 ± 12.3 years). Regression analyses revealed that older age predicted a decrement in performance for tests of crossed motor response inhibition as well as slower motor initiation with the left hand. Changes in action-intention with aging appear to be related to alterations of interhemispheric communication and/or age-related right hemisphere dysfunction; however, further research is needed to identify the mechanisms for age-related changes in the brain networks that mediate action-intention.
Foster, E Michael
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.
Basim, H. Nejat; Begenirbas, Memduh; Can Yalcin, Rukiye
One of the most indispensable and important elements of education is teachers whose personality closely affects training and education. In this context, this study examined the effects of teachers' personality traits on their emotional exhaustion in a mediating model which centers around emotional labor. Data were obtained from 798 teachers…
Campbell, Rebecca; Patterson, Debra; Fehler-Cabral, Giannina
In recent years, there has been renewed interest among community psychologists in indigenous interventions, which are programs created by local practitioners (rather than researchers) already rooted in their communities. Indigenous interventions have strong ecological validity, but their effectiveness is often unknown because so few are rigorously evaluated. The goal of this project was to use Kelly and Trickett's ecological theory as a conceptual framework for evaluating an indigenous intervention and its mediating mechanisms of effectiveness. The focal intervention was a midwestern Sexual Assault Nurse Examiner (SANE) program, which provides post-assault medical care, crisis intervention, and medical forensic exams for sexual assault survivors. Prior studies of SANE programs have suggested that these interventions may help increase sexual assault prosecution rates. In this case example, we used a mixed methods design to determine if this program contributed to increased prosecution rates, and if so, why. Based on qualitative interviews with key stakeholders, we found substantial evidence for the Principle of Interdependence such that the SANE program strengthened the interconnections between the legal and medical systems, which contributed to increased prosecution. The intervention was effective in these outcomes because it promoted Cycling of Resources throughout the systems and fostered Adaptation of new roles for legal and medical personnel. Moving beyond this specific case example, this paper also examines cross-cutting advantages and struggles of using an ecological approach in the evaluation of indigenous community interventions.
Ahmet Cezmi SAVAS
Full Text Available The purpose of this study is to investigate the effects of depression level on the effects of work stress on the intention of leaving employment among education employee. The sample of the current research includes 67 principals, 79 assistant principals, and 163 teachers who work in various schools in the city center of Gaziantep during 2013-2014 education year. It was found that work stress and depression level were significant predictors of intention of leaving employment. Based on the results that the mediator effect of depression level when the level of work stress of education employee is predicting the intention of leaving of employment, it was found the level of depression is a mediator, and related solutions are presented.
The aim of this investigation was to replicate the stereotype threat and lift effects in a motor task in a neutral sex-typed activity, using somatic and cognitive anxiety as key mediators of these phenomena. It was hypothesized that an ingroup/outgroup social categorization based on gender would have distinctive effects for female and male participants. A total of 161 French physical education students were randomly assigned to three threat conditions--no threat, female threat, and male threat--thus leading to a 3 x 2 (threat by gender) design. The analyses revealed a stereotype lift effect on the performances for both male and female participants, as well as a stereotype threat effect only for female participants. They also indicated that somatic anxiety had a mediating effect on the performance of female participants targeted by a negative stereotype, but that it had a facilitating effect on their performance. The stereotype threat and lift effects on motor tasks were replicated in a neutral sex-typed activity and somatic anxiety seems to have a facilitating mediating effect of the relationships between the gender-conditions (control or female threat) interaction and free-throw performance. The model used to distinguish somatic and cognitive anxiety appeared to be a relevant means of explaining the stereotype threat and lift mechanisms.
Arrogante, Oscar; Aparicio-Zaldivar, Eva
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.
Konopack James F
Full Text Available Abstract Background Physical activity has been established as an important determinant of quality of life, particularly among older adults. Previous research has suggested that physical activity’s influence on quality of life perceptions is mediated by changes in self-efficacy and health status. In the same vein, spirituality may be a salient quality of life determinant for many individuals. Methods In the current study, we used path analysis to test a model in which physical activity, spirituality, and social support were hypothesized to influence global quality of life in paths mediated by self-efficacy and health status. Cross-sectional data were collected from a sample of 215 adults (male, n = 51; female, n = 164 over the age of 50 (M age = 66.55 years. Results The analysis resulted in a model that provided acceptable fit to the data (χ2 = 33.10, df = 16, p Conclusions These results support previous findings of an efficacy-mediated relationship between physical activity and quality of life, with the exception that self-efficacy in the current study was moderately associated with physical health status (.38 but not mental health status. Our results further suggest that spirituality may influence health and well-being via a similar, efficacy-mediated path, with strongest effects on mental health status. These results suggest that those who are more spiritual and physically active report greater quality of life, and the effects of these factors on quality of life may be partially mediated by perceptions of self-efficacy.
Wang, Yang; Chang, Ying; Fu, Jialiang; Wang, Lie
Burnout among nurses not only threatens their own health, but also that of their patients. Exploring risk factors of nurse' burnout is important to improve nurses' health and to increase the quality of health care services. This study aims to explore the relationship between work-family conflict and burnout among Chinese female nurses and the mediating role of psychological capital in this relationship. This cross-sectional study was performed during the period of September and October 2010. A questionnaire that consisted of the Maslach Burnout Inventory-General Survey (MBI-GS), the work-family conflict scale and the psychological capital questionnaire (PCQ-24) scale, as well as demographic and working factors, was distributed to nurses in Liaoning province, China. A total of 1,332 individuals (effective response rate: 78.35%) became our subjects. Hierarchical linear regression analyses were performed to explore the mediating role of psychological capital. Both work interfering family conflict and family interfering work conflict were positively related with emotional exhaustion and cynicism. However, work interfering family conflict was positively related with professional efficacy whereas family interfering work conflict was negatively related with it. Psychological capital partially mediated the relationship of work interfering family conflict with emotional exhaustion and cynicism; and partially mediated the relationship of family interfering work conflict with emotional exhaustion, cynicism and professional efficacy. Work-family conflict had effects on burnout and psychological capital was a mediator in this relationship among Chinese nurses. Psychological capital was a positive resource for fighting against nurses' burnout.
Brooks, Patricia J; Kempe, Vera
In this study, we sought to identify cognitive predictors of individual differences in adult foreign-language learning and to test whether metalinguistic awareness mediated the observed relationships. Using a miniature language-learning paradigm, adults (N = 77) learned Russian vocabulary and grammar (gender agreement and case marking) over six 1-h sessions, completing tasks that encouraged attention to phrases without explicitly teaching grammatical rules. The participants' ability to describe the Russian gender and case-marking patterns mediated the effects of nonverbal intelligence and auditory sequence learning on grammar learning and generalization. Hence, even under implicit-learning conditions, individual differences stemmed from explicit metalinguistic awareness of the underlying grammar, which, in turn, was linked to nonverbal intelligence and auditory sequence learning. Prior knowledge of languages with grammatical gender (predominantly Spanish) predicted learning of gender agreement. Transfer of knowledge of gender from other languages to Russian was not mediated by awareness, which suggests that transfer operates through an implicit process akin to structural priming.
Gannouni, Kais; Ramboarison-Lalao, Lovanirina
When exploring the effects of leadership on students, most studies have focused on either how leadership affects the students' academic outcomes or how it contributes to their personal development. This study merged both approaches and aimed to measure the mediating effects of self-efficacy and self-determination among leadership, students'…
Madon, Stephanie; Guyll, Max; Buller, Ashley A.; Scherr, Kyle C.; Willard, Jennifer; Spoth, Richard
This research examined whether self-fulfilling prophecy effects are mediated by self-verification, informational conformity, and modeling processes. The authors examined these mediational processes across multiple time frames with longitudinal data obtained from two samples of mother – child dyads (N1 = 487; N2 = 287). Children’s alcohol use was the outcome variable. The results provided consistent support for the mediational process of self-verification. In both samples and across several years of adolescence, there was a significant indirect effect of mothers’ beliefs on children’s alcohol use through children’s self-assessed likelihood of drinking alcohol in the future. Comparatively less support was found for informational conformity and modeling processes as mediators of mothers’ self-fulfilling effects. The potential for self-fulfilling prophecies to produce long lasting changes in targets’ behavior via self-verification processes are discussed. PMID:18665708
Tan Poh Leong; Laily Paim
This study aimed to measure the effect of intention as a mediator in the relationship between internal factors and external factors on consumption. The factors were a) internal factors: knowledge, awareness, health consciousness, product attributes, environmental concern, and b) external factors: subjective norms, perceived behaviour control, and media and advertisement. From the review of literature, there were limited studies done on the mediating effect of intention on the relationship bet...
Guo, Peng; Zhang, Chunfang; Wang, Yi; Yu, Xinwei; Zhang, Zhichao; Zhang, Dongdong
This study investigated the effects of different long-term fertilizations on humic substances (HSs), humic acids (HAs) and humins, functioning as redox mediators for various microbial redox biotransformations, including 2,2',4,4',5,5'- hexachlorobiphenyl (PCB 153 ) dechlorination, dissimilatory iron reduction, and nitrate reduction, and their electron-mediating natures. The redox activity of HSs for various microbial redox metabolisms was substantially enhanced by long-term application of organic fertilizer (pig manure). As a redox mediator, only humin extracted from soils with organic fertilizer amendment (OF-HM) maintained microbial PCB 153 dechlorination activity (1.03 μM PCB 153 removal), and corresponding HA (OF-HA) most effectively enhanced iron reduction and nitrate reduction by Shewanella putrefaciens. Electrochemical analysis confirmed the enhancement of their electron transfer capacity and redox properties. Fourier transform infrared analysis showed that C=C and C=O bonds, and carboxylic or phenolic groups in HSs might be the redox functional groups affected by fertilization. This research enhances our understanding of the influence of anthropogenic fertility on the biogeochemical cycling of elements and in situ remediation ability in agroecosystems through microorganisms' metabolisms. Copyright © 2017 Elsevier Ltd. All rights reserved.
Highland, Krista B.; Tercyak, Kenneth P.; Luta, Gheorghe; Niaura, Raymond S.
Introduction Parenting has been shown to affect smoking among children in U.S. majority groups, but less is known about this association among multiethnic urban populations. Our study examines the role of parenting on smoking among a highly diverse sample. Methods Health surveys were collected from eighth graders (N =459) in 2 low-income urban schools. Structural equation models examined the direct and indirect effects of authoritative parenting on lifetime smoking. A moderated mediation analysis examined whether indirect effects of authoritative parenting vary among racial/ethnic groups. Results Authoritative controlling parenting, characterized by limit setting, was positively associated with anti-tobacco parenting. Anti-tobacco parenting was inversely associated with smoking, mediating the relationship between controlling parenting and smoking. There was no evidence that mediation was moderated by race/ethnicity. Conclusions Parent training, which focuses on setting rules and expectations, can be an important and universal element of smoking prevention programs targeted to youth in diverse communities. PMID:24306966
Stanton, Cassandra A; Highland, Krista B; Tercyak, Kenneth P; Luta, Gheorghe; Niaura, Raymond S
Parenting has been shown to affect smoking among children in U.S. majority groups, but less is known about this association among multiethnic urban populations. Our study examines the role of parenting on smoking among a highly diverse sample. Health surveys were collected from eighth graders (N = 459) in 2 low-income urban schools. Structural equation models examined the direct and indirect effects of authoritative parenting on lifetime smoking. A moderated mediation analysis examined whether indirect effects of authoritative parenting vary among racial/ethnic groups. Authoritative controlling parenting, characterized by limit setting, was positively associated with anti-tobacco parenting. Anti-tobacco parenting was inversely associated with smoking, mediating the relationship between controlling parenting and smoking. There was no evidence that mediation was moderated by race/ethnicity. Parent training, which focuses on setting rules and expectations, can be an important and universal element of smoking prevention programs targeted to youth in diverse communities.
Purba, D.E.; Oostrom, J.K.; Van der Molen, H.T.; Born, M.P.
This study aims to investigate the mediating effect of affective commitment on the relationship between personality and organizational citizenship behavior (OCB) in a non-Western culture. We attempt to increase understanding of how personality and work attitudes affect OCB in a culture where
Annissa Chairum Soebandono
Full Text Available This research was conducted for analyzing the effect of mediating variable that is individual task proactivity as one of the proactivities of behavior towards the relationship between self-efficacy and the employees’ performance in the logistics companies of shipping the goods. It uses convenience sampling, which is a non-probability sampling method for getting the sample of 52 employees. They were divided into two divisions, namely infrastructure and quality assurance. The questionnaire consists of two parts, in which some were assessed by themselves and others that were assessed by the supervisor. They were analyzed using path analysis using analytical tools developed by Hayes, Preacher-Hayes with the simple mediation models. It was found that employees have self-efficacy, individual task proactivity, and relatively high performance, in which individual task proactivity can be a mediating variable on the effect self-efficacy on performance.
Lee, Sang Won; Bae, Geum Ye; Rim, Hyo-Deog; Lee, Seung Jae; Chang, Sung Man; Kim, Byung-Soo; Won, Seunghee
Previous studies have reported that childhood maltreatment experiences could induce biological and psychological vulnerability in depressive disorders. However, it is still unclear that type-specific effects of childhood maltreatment on psychological resilience, depressive symptoms and interactions among childhood maltreatment experiences, resilience, and depressive symptoms. A total of 438 medical students were included in the study. The Childhood Trauma Questionnaire-Short Form, the Conner-Davidson Resilience Scale, and the Beck Depression Inventory were used for measuring childhood maltreatment experiences, psychological resilience, and depressive symptoms, respectively. We investigated the effects of childhood maltreatment experiences on resilience and depressive symptoms using correlation analysis. In addition, we analyzed the mediating effect of resilience on the association between childhood maltreatment and symptoms of depression. Among childhood maltreatment, emotional neglect was a significant predictor of the scores of low resilience and high depressive symptoms in both gender groups (all psresilience was found to be a mediator connecting emotional neglect experiences with depressive symptoms. Our results suggest that emotional neglect has detrimental effects on mood and resilience, and clinicians need to focus on the recovery of resilience when they deal with depressive symptoms in victims of childhood maltreatment.
Full Text Available The primary objective of this study is to investigate the effects of the sub-dimension of consumer-based brand equity which are called brand awareness, perceived quality, brand associations and brand loyalty on brand preference and the second goal is to find out the mediating role of family on these relations. For this purpose, a study was conducted with the participation of 295 people in Ankara. According to the research result, perceived quality and brand loyalty positively effects on brand preferences but there is no significant effect of brand awareness and brand association on these preferences. And also it is observed that family does not have any mediating role on these relations.
Erickson, Thane M; Mayer, Stefanie E; Lopez-Duran, Nestor L; Scarsella, Gina M; McGuire, Adam P; Crocker, Jennifer; Abelson, James L