This paper examines the relationship between psychological contract breach and insomnia among older workers (aged 40 years and up). Drawing upon the conservation of resources theory, we conceptualize breach as a stressful event characterized by a perceived threat, failure to gain, or actual loss of valued resources, which increases psychological distress and insomnia. Moreover, we hypothesized that older workers' generativity concerns would act as a personal resource that would buffer the negative impact of breach. We tested our proposed model in 2 studies (Study 1 = 123; Study 2 = 168) of employee–spouse dyads. Results revealed that psychological distress mediated the relationship between psychological contract breach and insomnia. These mediated relationships were significant for those with low, but not for those with high levels of generativity concerns. These effects remained significant even after controlling for perceived organizational support (i.e., a social exchange mechanism). Theoretical and practical implications are discussed. 相似文献
Objectives: There are 3 standardized versions of the Detection Response Task (DRT), 2 using visual stimuli (remote DRT and head-mounted DRT) and one using tactile stimuli. In this article, we present a study that proposes and validates a type of auditory signal to be used as DRT stimulus and evaluate the proposed auditory version of this method by comparing it with the standardized visual and tactile version.
Methods: This was a within-subject design study performed in a driving simulator with 24 participants. Each participant performed 8 2-min-long driving sessions in which they had to perform 3 different tasks: driving, answering to DRT stimuli, and performing a cognitive task (n-back task). Presence of additional cognitive load and type of DRT stimuli were defined as independent variables. DRT response times and hit rates, n-back task performance, and pupil size were observed as dependent variables.
Results: Significant changes in pupil size for trials with a cognitive task compared to trials without showed that cognitive load was induced properly. Each DRT version showed a significant increase in response times and a decrease in hit rates for trials with a secondary cognitive task compared to trials without. Similar and significantly better results in differences in response times and hit rates were obtained for the auditory and tactile version compared to the visual version. There were no significant differences in performance rate between the trials without DRT stimuli compared to trials with and among the trials with different DRT stimuli modalities.
Conclusions: The results from this study show that the auditory DRT version, using the signal implementation suggested in this article, is sensitive to the effects of cognitive load on driver's attention and is significantly better than the remote visual and tactile version for auditory–vocal cognitive (n-back) secondary tasks. 相似文献
AbstractUranium mining and ore processing are known to be harmful to the environment and human health if the waste generated is not managed properly. The aim of the present study is to determine the radiological indices in the mill tailings and review the possible attempts to utilize and minimize its hazardous effect. The activity concentrations of natural radionuclides, 238U, 232Th, 226Ra, and 40K have been measured by gamma spectrometry using HP-Ge detector. The average activity concentrations of 238U, 232Th, 226Ra, and 40K in the tailings wastes were 2071.8, 59.92, 6921.262, and 445. 57?Bq/kg respectively which are higher than the international average limit. The ranges of hazard indices such as Radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), γ-radiation hazard index Iγ, Dose rate (nGy/h) and annual effective dose equivalent (AED), were estimated. Uraniumm isotopic ratios in the ore –material and mill tailing samples indicate migration out of radionuclides to the surrounding environment causing contamination and many dangerous diseases. Fairly, all investigated tailing waste samples do not satisfy the universal standards, the studied wastes relatively still have high uranium contents and need reprocessing. 相似文献
Fish is a major source of livelihood for the majority of people living around the Okavango Delta in northwestern Botswana. Gender dynamics and governance regimes determine differential access to, and control of, resources between women and men in the area. The purpose of this case study is to critically assess the embeddedness of gendered inequities in the governance of Okavango Delta fishery. Primary data was collected through focus group discussions and face‐to‐face interviews of 96 basket fishers from five villages along the Panhandle area of the Okavango River. The study found that past and present Okavango Delta fishery policy and programme interventions tended to entrench rather than minimize gendered disparities between women and men fishers' access to and control over fish resources, asset accumulation and employment opportunities. Basket fishers have intimate knowledge of flood variability, fish migration and habitat and use this knowledge to make decisions about when and where to harvest what fish species. Women fishers' ecological knowledge, interests and concerns however, have been excluded from current zoning and closed season regulations and co‐management structures. The paper concludes that past and current development interventions as well as the regulatory framework continue to entrench pre‐existing gender relations in the fishery sector which excludes, disempowers and marginalizes women fishers. We recommend innovative co‐management and local based structures which recognize the diversity of interests and interest groups. 相似文献