调节模式对选择超载的影响及其机制：一个有中介的调节模型

当前,选择超载领域研究的焦点已从验证其是否存在,转向至其何时存在,即边界条件的探讨。本研究基于调节模式理论,分别以决策后悔和延迟选择作为选择超载的指标,开展两个实验探查选择超载存在的调节模式条件及所涉及的内在机制。实验1以决策后悔作指标,运用量表测试法操纵调节模式,初步探讨调节模式对选择超载的影响,结果发现调节模式调节了选项集与决策后悔的关系,即对评估模式的个体来说,面对大选项集比小选项集时体验到更强的后悔情绪,出现了选择超载,而对运动模式的个体而言,两种条件下的决策后悔无显著差异;实验2以延迟选择作指标,通过任务启动法操纵调节模式,进一步探讨调节模式对选择超载的影响及其机制,结果发现调节模式调节了选项集与延迟选择的关系,即对评估模式的个体来说,面对大选项集比小选项集时更倾向于延迟选择,出现了选择超载,而对运动模式的个体而言,两种条件下的延迟选择偏好无显著差异,进一步有中介的调节模型分析表明选择难度可以部分解释这种效应。总之,通过采用不同方法操纵调节模式,选取不同的选择超载指标,数据结果都一致支持：评估模式的个体比运动模式的个体更容易出现选择超载,选择难度在其中发挥着一定的中介作用。     

辩证分析兴奋性氨基酸对神经细胞的双重作用

兴奋性氨基酸（ＥＡＡｓ） 广泛分布于中枢神经系统,参与多种生理过程包括学习、记忆和伤害感受等。然而,ＥＡＡｓ 受体的过度兴奋却可引发一系列细胞事件,最终导致神经元的损伤与死亡。许多神经退行性疾病如早老性痴呆、癫痫和肌侧索硬化症等都与ＥＡＡｓ 的兴奋毒作用有关。目前的研究表明,由ＥＡＡｓ 受体过度兴奋所引发的细胞内钙超载是导致神经元死亡的最终途径     

Le rôle des stresseurs sur le comportement d’innovation : Quand le leadership habilitant du supérieur protège le potentiel d’innovation des travailleurs

This study focuses on the relationship between workplace stressors and innovative work behavior. The joint analysis of the mediation process supporting this relationship as well as the influence of certain external conditions such as the moderating role of the supervisor has made it possible to highlight the dynamic that underlie the relationship between stressors and innovation behavior. Using the challenge-hindrance model, this theory proposes that challenge (i.e., role overload) and hindrance (i.e., role ambiguity and role conflict) stressors exert positive and negative indirect effects, respectively, on innovative work behavior through psychological empowerment (PE). Furthermore, empowering leadership (EL) has the potential to optimize the benefits of challenge stressors and reduce the effects of hindrance stressors on PE and indirectly on innovation work behavior. In support of these predictions, a time-lagged study of 146 employees from various Canadian firms reveals that hindrance stressors, particularly role ambiguity, are negatively related to innovative work behavior through PE. Moreover, when EL was high, the positive effects of role overload were enhanced through PE while the negative effects of role ambiguity and role conflict were attenuated. The implications of these findings for research and practice are discussed.     

Dislocation relaxation and alloy softening of bcc alloys

Recently, low-frequency internal friction measurements on a series of Fe–Cr alloys by Konstantinovi? and Terentyev [M.J. Konstantinovi? and D. Terentyev, Mater. Sci. Eng. A 521–522 (2009) p.106] have demonstrated that increasing Cr concentrations lead to an increase in the strength of the β-relaxation at the cost of the γ-relaxation (Chambers’ notation). In the same concentration and temperature regime, the alloys show alloy softening. It is argued that both phenomena are due to the same process, namely the influence of foreign atoms on the transformation of the cores of a ₀?1 1 1?/2 screw dislocations from their low-temperature configuration, capable of forming kink pairs on {1 1 0} planes, to their high-temperature configuration with kink-pair generation on {2 1 1} planes.     

Irradiation-enhanced twin boundary migration in BCC Fe

The effects of irradiation on twin boundary migration in BCC Fe are studied by atomistic simulations. It is found that under the applied shear strain–stress, thermal spikes may create twinning dislocation loops (TDLs) at twin boundaries, so triggering twinning. Irradiation-generated clusters of point defect at twin boundaries may act as sources to nucleate TDLs. When a vacancy loop intersects with a twin boundary, the critical stress to activate a TDL is less than half of that required for a defect-free twin boundary.     

Passive leadership,role stressors,and affective organizational commitment: A time-lagged study among health care employees

IntroductionThis study examines the relationships of passive leadership and role stressors to affective organizational commitment among hospital employees.ObjectiveThis study's objective was to understand the mediating effect of role stressors (conflict, overload, and ambiguity) in the relation between passive leadership and affective organizational commitment.MethodWe used a structural equation modeling approach on a sample of 185 hospital employees and a time-lagged design in which predictor and mediators were assessed at Time 1 and affective organizational commitment was obtained 3 years later.ResultsFindings revealed that passive leadership was positively related to all three role stressors and that role ambiguity fully mediated a negative relationship between passive leadership and affective organizational commitment. Moreover, the relationship between passive leadership and role conflict was stronger when role overload was high.ConclusionThis study suggests organizations should strive to limit the emergence of passive leadership behaviors among supervisors due to their detrimental effects on the long-term development of affective commitment via role ambiguity.     

Job Satisfaction as a Mediator of the Relationship Between Job Stressors and Affective, Continuance, and Normative Commitment: A Path Analytical Approach

This article investigates the potential mediating role of job satisfaction between job stressors—namely, role overload-quantitative, role overload-qualitative, and lack of career development—as sources of stress on the one hand, and various facets of organizational commitment—namely, affective, continuance, and normative—on the other hand. A sample of 361 employees in a number of organizations in the United Arab Emirates (UAE) was used. Path analysis revealed that role overload-quantitative directly and negatively influences both job satisfaction and affective commitment and that lack of career development as a source of stress directly and negatively influences job satisfaction. Findings also suggest that job satisfaction mediates the influences of role overload-quantitative on various facets of organizational commitment. Implications, future lines of research, and limitations are discussed.     

角色压力源对教师生理健康与心理健康的影响

首先,对角色压力源量表在中国文化背景下的适用性进行了检验,6所学校586份调查问卷的探索性因素分析和内部一致性分析表明,角色压力源问卷具有较好的效度和信度;7所学校612份调查问卷的验证性因素分析进一步验证了角色压力源问卷的效度和信度。然后,利用7所学校612份有效数据,采用层次回归分析考察了角色压力源与教师生理健康、心理健康的关系,结果表明:角色压力源对教师的生理健康与心理健康有显著的负向影响。     

Leading in times of crisis: How perceived COVID-19-related work intensification links to daily e-mail demands and leader outcomes

The COVID-19 crisis brought numerous challenges to work life. One of the most notable may be the acceleration of digital transformation, accompanied by an intensification of e-mail usage and related demands such as high e-mail workload. While research quickly started to examine the implications of these changes for employees, another important group of stakeholders has been overlooked: leaders. We focus on leaders during the COVID-19 crisis and examine how COVID-19-related work intensification links to leaders' e-mail overload appraisal and finally exhaustion and transformational leadership, a leader behaviour especially needed in times of crisis. In a 5-day diary study in September 2020, 84 leaders responded to daily surveys on 343 days. Results of multilevel analysis showed that perceived COVID-19-related work intensification was positively linked to worktime spent dealing with e-mail and appraised e-mail overload. E-mail overload appraisal was positively related to leaders' exhaustion, but unrelated to their transformational behaviour. Day-specific time spent dealing with e-mail, however, was negatively related to transformational leadership. E-mail overload appraisal mediated the relationship between COVID-19-related work intensification and exhaustion. Turning the focus on leaders during the COVID-19 crisis, our study has important implications for the design of work of leaders in times of crisis and beyond.     

肿瘤是限铁机制的体现,其功能是防卫细菌——解读肿瘤之谜

通过哲学思辨质疑肿瘤是异己的判断.列举肿瘤的特征,探索肿瘤的实质.通过对限铁机制和铁致癌机理的研究,对铁致癌以及铁是癌细胞营养素的假设提出质疑.经过辩证思考推断,肿瘤是对坏血酸遗传缺陷的代偿性补救措施,是限铁机制的体现,是进化适应的特征,它的功能是聚集游离铁,不让细菌获得铁,以降低细菌感染的风险.同时提供证据,证明肿瘤确有降低细菌感染风险的功效.继而提出细胞癌变的可能机理,并据此解释肿瘤何以转移,何以避免免疫摧毁.最后提出对肿瘤发病机制的定义,并提出预防肿瘤的关键措施.