Experimental Power for Indirect Effects in Group-randomized Studies with Group-level Mediators

Mediation analyses have provided a critical platform to assess the validity of theories of action across a wide range of disciplines. Despite widespread interest and development in these analyses, literature guiding the design of mediation studies has been largely unavailable. Like studies focused on the detection of a total or main effect, an important design consideration is the statistical power to detect indirect effects if they exist. Understanding the sensitivity to detect indirect effects is exceptionally important because it directly influences the scale of data collection and ultimately governs the types of evidence group-randomized studies can bring to bear on theories of action. However, unlike studies concerned with the detection of total effects, literature has not established power formulas for detecting multilevel indirect effects in group-randomized designs. In this study, we develop closed-form expressions to estimate the variance of and the power to detect indirect effects in group-randomized studies with a group-level mediator using two-level linear models (i.e., 2-2-1 mediation). The results suggest that when carefully planned, group-randomized designs may frequently be well positioned to detect mediation effects with typical sample sizes. The resulting power formulas are implemented in the R package PowerUpR and the PowerUp!-Mediator software (causalevaluation.org).     

Help yourself by helping others: The joint impact of group member organizational citizenship behaviors and group cohesiveness on group member objective task performance change

This paper examines how a group member's individual‐targeted citizenship behavior (OCBI) and organization‐targeted citizenship behavior (OCBO) interact with a salient group‐level contextual variable, group cohesiveness, to foster positive change for that group member, starting with job self‐efficacy change, and followed by objective task performance change. Over a span of 6 months, we engaged in multilevel, multisource, multistage data collection and surveyed 587 members in 83 work groups. Our results indicate that a group member's OCBI, in comparison with OCBO, is more positively related to his or her job self‐efficacy change. Group cohesiveness was found to attenuate the relationship between a group member's OCBI and job self‐efficacy change, and conversely, to accentuate the relationship between a group member's OCBO and job self‐efficacy change. Furthermore, a group member's job self‐efficacy change mediated the interactive effects of the group member's OCBI and group cohesiveness (as well as the group member's OCBO and group cohesiveness) on his or her objective task performance change.     

Influence of plastic strain localisation on the mechanical properties of metal matrix composites

The aim of the present study is to reveal the most critical underlying factor influencing the mechanical properties of metal matrix composites (MMCs). It is shown that the mechanical properties of MMCs are essentially governed by the degree of strain localisation during plastic deformation. In other words, the MMCs exhibit superior mechanical performance only if the strain localisation is obviously inhibited and the accumulated stresses can be effectively transferred out. The work provides a new perspective in guiding the design of next-generation high-performance MMCs by suppressing the strain localisation as far as possible.     

Engagement Attentional Bias toward Value-Associated Stimuli

Recent evidence has shown that learning to associate the value of behavioral outcomes with specific stimuli (i.e., value learning/association) can induce attentional capture in a subsequent visual search task. Here we investigated the component of attentional bias toward value-associated stimuli in the dot-probe paradigm. In the training phase, participants learned to associate nonsense shape outlines with monetary wins or losses. The shapes were then used as cues in an explicit no feedback dot-probe task. Probe appeared at either the salient (congruent trial) or nonsalient location (incongruent trial). Results indicate attentional bias toward value-associated stimuli, futher more this attentional bias is driven by an engagement bias.     

浅议青年文化发展与构建社会主义和谐社会

本文以分析青年群体的基本特点为起点,集中阐释了青年群体在实现自身社会化的过程中,青年文化对其社会角色的塑造以及青年文化在构建社会主义和谐社会历史进程中的独特作用。     

系统化细菌鉴定方法的探索及其启示

细菌鉴定有着悠久的历史。随着现代科学技术的快速发展,许多新方法、新技术在细菌鉴定中广泛应用,大大提高了鉴定水平。细菌鉴定技术的发展历程,引发我们探索系统化细菌鉴定的新方法,并带给我们对认识事物、看待问题、进行科学思维、继承与创新等方面的哲学思考。     

The timeline of threat processing in repressors: more evidence for early vigilance and late avoidance

Evidence is mixed concerning whether individuals with a repressive coping style can actually selectively avoid threatening stimuli. Recent research (Calvo & Eysenck, 2000) on repressors’ threat processing suggests that it is necessary to take into account the timeline of this bias. A spontaneous trait inference paradigm was used here to test the hypothesis that repressors would, relative to others, be less likely to infer unfavorable and threatening traits. However, if pressured to make trait inferences quickly, it was predicted that they would be less likely than others to infer favorable and unthreatening traits. Repressors and nonrepressors were presented with passages that could have supported positive or negative trait inferences. In Study 1, they were asked to respond to trait words as quickly as possible but were not held accountable for doing so. In Study 2, time pressure was increased to capture uncorrected trait inferences. Results indicated that repressors were more likely to make positive trait inferences than others when simply asked to respond quickly. Under time pressure, this bias disappeared. Results point to the importance of taking into account an important moderator between coping style and threat, namely, the stage of processing at which differences in threat processing are being assessed.     

母亲守门行为与父子依恋的关系：父亲教养投入的中介作用

以597个核心家庭的父亲、母亲和青少年为研究对象,通过问卷调查探讨了母亲守门行为与父子依恋的关系以及父亲教养投入在其中的中介作用。结果表明：（1）母亲开门行为正向预测父子依恋,母亲关门行为负向预测父子依恋;（2）母亲开门行为通过正向预测父亲教养投入的部分中介作用间接预测父子依恋,而母亲关门行为通过负向预测父亲教养投入的部分中介作用间接预测父子依恋。研究结果扩展了母亲守门行为的作用效果研究,对家庭教育实践具有一定的指导意义。