Cortisol on Sunday as indicator of recovery from work: Prediction by observer ratings of job demands and control

Several considerations guided the research reported in this paper. First, recovery is pivotal for preventing stressful experiences from inducing long-term consequences. Second, cortisol levels under relaxed conditions constitute a good baseline measure. Third, there are many calls to avoid common method problems. Therefore, the Job Demands–Control (JDS) model, one of the most prominent models in occupational stress, should be tested by a combination of observation, self-report, and physiological data in terms of predicting recovery-related variables. In a sample of 53 Swiss employees, we assessed the JDS variables, demands and control, by systematic observation, fatigue at the end of work as an indicator of short-term recovery by questionnaire, and delayed recovery by baseline levels of cortisol on a Sunday under relaxing conditions. In line with expectations, regression analyses showed an impact of job demands and control on Sunday cortisol levels, and this effect was fully mediated by after work fatigue. Contrary to expectations, there was no significant interaction between job demands and control. Demonstrating that job demands and control predict after-work fatigue as well as a delayed physiological marker of recovery, these findings suggest that high after-work fatigue may entail costs to the individual’s physiological systems.     

工作经验对社会企业创业资源整合的影响

很多成功的社会企业创建者都有着丰富的先前工作经验,且工作经验对创业过程有着重要的影响。对此,在结合了资源基础理论、知识转移理论的基础上,运用扎根理论,通过收集分析典型社会企业的案例资料,构建出"社会企业创建者的先前工作经验对创业资源整合的影响"的理论框架,并分析了先前工作经验对社会企业创业资源整合的影响机制。研究结果表明,社会创业者的先前工作经验对创业资源的整合能力有正向的影响关系。     

Agency Problems and Airport Security: Quantitative and Qualitative Evidence on the Impact of Security Training

We analyze the issue of agency costs in aviation security by combining results from a quantitative economic model with a qualitative study based on semi‐structured interviews. Our model extends previous principal‐agent models by combining the traditional fixed and varying monetary responses to physical and cognitive effort with nonmonetary welfare and potentially transferable value of employees' own human capital. To provide empirical evidence for the tradeoffs identified in the quantitative model, we have undertaken an extensive interview process with regulators, airport managers, security personnel, and those tasked with training security personnel from an airport operating in a relatively high‐risk state, Turkey. Our results indicate that the effectiveness of additional training depends on the mix of “transferable skills” and “emotional” buy‐in of the security agents. Principals need to identify on which side of a critical tipping point their agents are to ensure that additional training, with attached expectations of the burden of work, aligns the incentives of employees with the principals' own objectives.     

Interactive effects of urbanization and year on invasive and native ant diversity of sacred groves of South India

Urban Ecosystems - Urbanization is a major threat to native biodiversity. Invasion of tramp species is a major consequence of urbanization, which might threaten native species. Ants are established...     

Discrete-time survival analysis under ranked set sampling: an application to Turkish motor insurance data

Survival models with continuous-time data are still superior methods of survival analysis. However when the survival data is discrete, taking it as continuous leads the researchers to incorrect results and interpretations. The discrete-time survival model has some advantages in applications such as it can be used for non-proportional hazards, time-varying covariates and tied observations. However, it has a disadvantage about the reconstruction of the survival data and working with big data sets. Actuaries are often rely on complex and big data whereas they have to be quick and efficient for short period analysis. Using the mass always creates inefficient processes and consumes time. Therefore sampling design becomes more and more important in order to get reliable results. In this study, we take into account sampling methods in discrete-time survival model using a real data set on motor insurance. To see the efficiency of the proposed methodology we conducted a simulation study.     

Complexity properties of complementary prisms

The complementary prism \(G\bar{G}\) of a graph G arises from the disjoint union of the graph G and its complement \(\bar{G}\) by adding the edges of a perfect matching joining pairs of corresponding vertices of G and \(\bar{G}\). Haynes, Henning, Slater, and van der Merwe introduced the complementary prism and as a variation of the well-known prism. We study algorithmic/complexity properties of complementary prisms with respect to cliques, independent sets, k-domination, and especially \(P_3\)-convexity. We establish hardness results and identify some efficiently solvable cases.     

A new approach to use multivariate auxiliary information in sample surveys

A new approach to form multivariate difference estimator is suggested which does not require the knowledge of unknown population parameters as such. It gives minimum variance among the class of multivariate difference estimators. The performance of this estimator with respect to Des Raj's (J. Amer. Statist. Assoc. 60 (1965), 270–277) multivariate difference estimator is illustrated. Using the information on two auxiliary variates, the robustness of Des Raj's estimator y_d is studied empirically. Two new estimators to estimate population mean/total are developed on the same lines as that of y_d. The performance of these estimators is studied for a wide variety of populations.