• Association between hindrance stress and state anxiety: the moderating role of HPA-axis function to acute stress

    分类: 心理学 >> 应用心理学 提交时间: 2023-09-14

    摘要:Objective: Nowadays, young adults are facing stressors from several aspects. They have already become the most anxious groups in Chinese society and in risk of developing a series of anxiety disorders. The theory of challenge-hindrance stress was proposed to explain the positive and negative outcomes of different stressors. It has been widely tested mostly in the field of organization and management. In the current study, we used the challenge-hindrance stress theory to clarify the association between stress in daily life and anxiety. We also examined the HPA-axis function buffering the influence of daily stress on anxiety.
    Methods: we used the edited Chinese version of challenge-hindrance stress scales to measure challenge and hindrance stress over 6 months. The level of anxiety was measured by state-trait anxiety inventory. We also carried out a Trier Social Stress Test (TSST) in laboratory and recorded the change of cortisol level during the 60 minutes right after the acute stress.
    Results: Results show that the recent level of hindrance stress positively predicts trait anxiety, but the level of challenge stress does not predict trait anxiety. It is also found that, the cortisol decline rate during the recovery of acute stress moderates the association between stress and anxiety. To be exact, individuals with low cortisol decline rate could not recover to baseline level even after rather long rest, and hindrance stress in their lives would lead to higher level of anxiety. But for individuals who has high cortisol decline rate after acute stress, they recover fast to baseline after the stressor disappear, and they become less anxious although facing the same level of hindrance stress
    Limitations: Firstly, we only examined anxiety but left other distal outcomes of stress such as wellbeing to be further studied. Secondly, we choose the decline rate of cortisol to represent the HPA-axis function instead of taking different systems into consideration. Thirdly, stress appraisal could be further examined in the challenge-hindrance stress researches in addition to different stressors.
    Conclusions: The current study checked the association between stress and anxiety under the framework of challenge-hindrance stress. We examined the moderating mechanism of HPA-axis function, and discussed the effect of physiological toughness from the respective of resources and demands.

  • The afterthought phenomenon in stress: impacts of retrospective appraisal on stress responses

    分类: 心理学 >> 应用心理学 提交时间: 2023-09-13

    摘要:Background: While psychosocial stressors trigger neuroendocrine responses and affect task performance, many studies overlook the dynamic nature of the stress appraisal process. Goal: This study aims to explore whether subjective appraisals at various time points can interpret individual stress responses, both behaviorally and physiologically, using controlled laboratory conditions. Methods: A total of 137 effective participants were recruited to induce individual stress states using the Trier Social stress Test (TSST). Subjective appraisals were measured both before (anticipatory appraisal) and after the stressor (retrospective appraisal). Concurrently, participants' cortisol responses and task performances were documented. Results: Findings indicate that anticipatory appraisal doesn't significantly impact task performance, whereas retrospective appraisal markedly affects performance of the corresponding tasks. Regarding cortisol levels, multivariate regression analysis revealed that only the retrospective appraisal of the speech task accounted for the observed variance in cortisol response under stress. Discussion: The data suggests that retrospective appraisals are more indicative of behavioral and physiological responses to psychosocial stressors than anticipatory appraisals. These findings lend empirical support to refining the biopsychosocial model and underscore the utility of retrospective appraisal in capturing individual stress response variations.

  • The Relation between X-ray and Ultraviolet Variability of Quasars

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要:The relation between X-ray and UV/optical variability in AGNs has been explored in many individual sources, however a large sample study is yet absent. Through matching the XMM-Newton serendipitous X-ray and UV source catalogs with SDSS quasars, we build a sample of 802 epoch-pairs of 525 quasars showing clear variability in logFx-logFuv space. After correcting for the effect of photometric noise, we find 35.6\pm2.1% of the epoch-pairs show asynchronous variability between X-ray and UV (brightening in one band but dimming in the other). This indicates only in 28.8\pm4.2% of the epoch-pairs the X-ray and UV variability are intrinsically coordinated. The variability synchronicity exhibits no dependence on physical parameters of quasars or the time lag of the epoch-pairs, except for stronger variability tends to have stronger synchronicity. Switches between synchronous and asynchronous variability are also seen in individual sources. The poor coordination clearly contradicts both the X-ray reprocessing model and the accretion rate variation model for AGN variability. The ratios of the observed X-ray variability amplitude to that in UV span a broad range and peak at ~ 2. The dominant fraction of the ratios appear too small to be attributed to X-ray reprocessing, and too large for accretion rate variation. The inhomogeneous disk model which incorporates both X-ray and UV/optical variability in AGNs is favored by the observed stochastic relation between X-ray and UV variations.

  • The Pan-STARRS1 z>5.6 quasar survey II: Discovery of 55 Quasars at 5.6

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要:The identification of bright quasars at z>6 enables detailed studies of supermassive black holes, massive galaxies, structure formation, and the state of the intergalactic medium within the first billion years after the Big Bang. We present the spectroscopic confirmation of 55 quasars at redshifts 5.6展开 -->