The relation between role overload and work performance remains insufficiently understood. Drawing upon conservation of resources theory, we expected role overload to negatively relate to performance through psychological strain and this relation to be buffered by leader–member exchange. Study 1 examined depression as a severe type of strain that mediates between role overload and in-role performance, job dedication, and voice behavior. Study 2 used generic, perceived strain as a mediator between role overload and in-role performance and reward recommendations. Both studies (...) tested LMX’s buffering effect, controlling for role ambiguity and conflict. A supplementary panel study assessed the temporal relationship between role overload and strain. Role overload triggered psychological strain, which undermined performance, and LMX acted as a buffer on role overload, but not on role ambiguity or role conflict. We discuss the implications of these findings for theory and practice. (shrink)

BackgroundAthletes will increase their state anxiety under stress situations, which will lead to the decline of sports performance. The improvement of anxiety by probiotics has been reported, but there is a lack of research in the athlete population. The purpose of the current study is to explore the effectiveness of probiotics in improving athletes’ state anxiety and sports performance under stress situations.MethodsWe conducted this single-arm study in Chongqing Institute of Sports Technology. In the 8-week study, 21 Chongqing young divers were (...) given probiotic Bifidobacterium animalis subsp. lactis BB-12 daily. The state anxiety and sports performance of athletes were measured before, during, and after the intervention, and the gut microbiota of athletes was measured before and after the intervention.ResultsThe intervention results showed that cognitive state anxiety, somatic state anxiety, and anxiety emotion were improved. In terms of gut microbiota, the intervention did not change the gut microbial composition but increased the abundance of Bifidobacteriaceae. At the 8th week, the performance of athletes under stress was significantly improved.LimitationsFirst of all, due to the restriction of the number of subjects in this study, there was no control group. Secondly, although the athletes’ diet was recorded in this study, the influence of this factor on gut microbiota was not eliminated. Finally, the anxiety level of the athletes in this study was obtained through a self-report, lacking physiological data in state anxiety.ConclusionThe results show that probiotics intervention can improve the state anxiety of athletes under stress situation and improve the performance of athletes under stress situation. (shrink)

PurposePast research has documented a significant relationship between family violence and adolescent violence. However, much is unknown about the processes through which this association occurs, especially in the non-Western cultural context. To address this gap, we propose an integrated model encompassing multiple pathways that connect family violence to adolescent violence. Specifically, this study investigates how family violence is related to adolescent violence through violent peer association, normative beliefs about violence, and negative emotions.MethodWe tested the model using the two-wave survey data (...) collected from a probability sample of more than 1,100 adolescents residing in one of the largest metropolitan areas in China in 2015 to 2016.Results and ConclusionsThe results indicated that family violence predicted adolescent violence perpetration. Violent peer association, normative beliefs, and negative emotions, however, mediated much of the relationship between family violence and adolescent violence. (shrink)

An improved image enhancement approach via nonsubsampled contourlet transform is proposed in this article. We constructed a geometric image transform by combining nonsubsampled directional filter banks and a nonlinear mapping function. Here, the NSCT of the input image is first decomposed for L-levels and its noise standard deviation is estimated. It is followed by calculating the noise variance and threshold calculation, and computing the magnitude of the corresponding coefficients in all directional subbands. Then, the nonlinear mapping function is used to (...) modify the NSCT coefficients for each directional subband, which keeps the coefficients of strong edges, amplifies the coefficients of weak edges, and zeros the noise coefficients. Finally, the enhanced image is reconstructed from the modified NSCT coefficients. Three experiments are carried out respectively on images from subjective vision quality and objective evaluation measures. The first experiment is the algorithm performed on images. The subsequent experiments are the information entropy and spatial frequency. The experimental results demonstrate that the proposed method can gain better performance in enhancing the low-contrast parts of an image while keeping its clear edges. (shrink)