Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-10-09 Cooperative journals: 《心理学报》
Abstract： Although studies have found that exercise can lead to changes in the plasticity of the motor cortex, little is known about the changes in primary motor cortex synaptic plasticity associated with different forms of exercise among older adults. The purpose of this study was to compare the differences in motor cortex synaptic plasticity associated with a small hand muscle among older adults who regularly participated in table tennis or tai chi or who were sedentary.Based on inclusion/exclusion criteria and their answers to a self-reported questionnaire, 54 older adults (60~70 years) were selected who often participated in table tennis (n = 18) or tai chi (n = 18) exercise or who were sedentary (n = 18). The target muscle was the abductor pollicis brevis of the right hand. Motor cortex synaptic plasticity associated with the abductor pollicis brevis muscle was induced by a paired combination of peripheral nerve electrical stimulation and transcranial magnetic stimulation with an interval of 25 ms (PAS25). Single-pulse and double-pulse transcranial magnetic stimulation was applied to the left primary motor cortex to measure changes in motor evoked potentials (MEPs) and short-interval intracortical inhibition recorded in the abductor pollicis brevis muscle before and after PAS25, to compare the differences in primary motor cortex synaptic plasticity among the three groups.The results showed that mean MEP amplitudes immediately and 30 and 60 min after PAS25 in the table tennis group were significantly higher than those in sedentary group; mean MEP amplitudes immediately and 30 min after PAS25 in the tai chi group were significantly higher than those in the sedentary group; and mean MEP amplitudes immediately and 30 and 60 min after PAS25 in the table tennis group were significantly higher than those in the tai chi group. There were no differences in the short-interval intracortical inhibition at any time point after PAS25 among the three groups.These results indicated that regular participation in table tennis or tai chi can induce a sustained increase in primary motor cortex excitability in older adults and that there are differences in primary motor cortex synaptic plasticity in older adults associated with different forms of exercise. These results suggest that increased synaptic plasticity in the motor cortex may play an important role in the acquisition and promotion of motor skills during exercise in older adults.
Subjects: Psychology >> Physiological Psychology submitted time 2023-06-27
Abstract： Although studies have found that exercise can lead to changes in the plasticity of the motor cortex, little is known about the changes in primary motor cortex synaptic plasticity associated with different forms of exercise among older adults. The purpose of this study was to compare the differences in motor cortex synaptic plasticity associated with a small hand muscle among older adults who regularly participated in table tennis or tai chi or who were sedentary.
Based on inclusion/exclusion criteria and their answers to a self-reported questionnaire, 54 older adults (60~70 years) were selected who often participated in table tennis (n=18) or tai chi (n=18) exercise or who were sedentary (n=18). The target muscle was the abductor pollicis brevis of the right hand. Motor cortex synaptic plasticity associated with the abductor pollicis brevis muscle was induced by a paired combination of peripheral nerve electrical stimulation and transcranial magnetic stimulation with an interval of 25 ms (PAS25). Single-pulse and double-pulse transcranial magnetic stimulation was applied to the left primary motor cortex to measure changes in motor evoked potentials (MEPs) and short-interval intracortical inhibition recorded in the abductor pollicis brevis muscle before and after PAS25, to compare the differences in primary motor cortex synaptic plasticity among the three groups.
The results showed that mean MEP amplitudes immediately and 30 and 60 min after PAS25 in the table tennis group were significantly higher than those in sedentary group; mean MEP amplitudes immediately and 30 min after PAS25 in the tai chi group were significantly higher than those in the sedentary group; and mean MEP amplitudes immediately and 30 and 60 min after PAS25 in the table tennis group were significantly higher than those in the tai chi group. There were no differences in the short-interval intracortical inhibition at any time point after PAS25 among the three groups.
These results indicated that regular participation in table tennis or tai chi can induce a sustained increase in primary motor cortex excitability in older adults and that there are differences in primary motor cortex synaptic plasticity in older adults associated with different forms of exercise. These results suggest that increased synaptic plasticity in the motor cortex may play an important role in the acquisition and promotion of motor skills during exercise in older adults.
Subjects: Psychology >> Developmental Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： Computational modeling applies the regulations and rules of mathematics. It can be used to assess the inconsistency of theory and empirical results, integrate and develop theories, and represent complex, nonlinear, and non-recursion organizational behavior phenomena. However, computational models have not been used much in organizational behavior research. Using complex network analysis and a literature review, this study introduced three widely used computational modeling approaches (i.e., agent-based, system dynamics, and cellular automata) and the topics and types of research questions these computational models address. Computational modeling can help researchers to explore new research fields, change the theoretical pattern of organizational behavior, and support and development the existing research achievements. This study is a tutorial manual of computational modeling in organizational behavior research.
Subjects: Psychology >> Social Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： Uncertainties in the external environment are constant and difficult to predict in a world filled with VUCA (volatility, uncertainty, complexity, ambiguity; Bennett & Lemoine, 2014), which has caused career shocks to become an increasingly important part of current career scholarship. Akkermans et al. (2018) defined a career shock as “a disruptive and extraordinary event that is, at least to some degree, caused by factors outside the focal individual’s control and that triggers a deliberate thought process concerning one’s career” (p. 4). These authors suggested that the occurrence of a career shock can either be positively or negatively valenced (Akkermans et al., 2018); that is, positive career shocks are more likely to be associated with positive career outcomes, and negative shocks are more likely to be associated with negative outcomes. However, due to individual differences in the cognition of events or time factors, this categorization may have some shortcomings. We found that the literature includes several theoretical perspectives that have been or could be used to scaffold our understanding of the positive or negative impacts of career shocks, and a multiperspective model may provide evidence to support the reclassification of career shocks and help clarify the effects of career shocks. First, we found that the main reasons for the positive or negative effects of career shocks on employees’ behaviour can be explained in terms of different mechanisms and processes. More specifically, the transactional model of stress and coping, the job demands-resources model, and affective event theory could help elucidate how different cognitive, motivational and emotional responses to a career shock can influence the effects of such shocks on behavioural outcomes, those providing insights into the different processes by which shocks impact outcomes. Event system theory focuses on the characteristics or attributes of career shock events that make them salient and therefore likely to impact such outcomes, which could also help explain how their impacts can be extended over time as events vary in duration and timing or as event strength evolves. Second, based on the transactional model of stress and coping, the present study proposed a new classification of career shocks, namely, challenging career shocks and hindering career shocks. Third, we explored the mechanism underlying the impacts of challenging and hindering career shocks on individual behaviour based on the transactional model of stress and coping, the job demands-resources model, and affective event theory. We proposed that challenging career shocks are positively related to problem-focused coping, work engagement and positive affectivity and that hindering career shocks are positively related to emotion-focused coping, burnout and negative affectivity. Furthermore, the attributes (e.g., the strength) of events could moderate the effects of career shocks. Finally, we identify a number of avenues for future research, including developing the concept and attributes of career shock, enriching the empirical research on the new classification of career shocks, exploring additional mechanisms underlying career shocks, and examining the outcomes of career shocks. The present study contributes to the emerging career shock literature by providing a new perspective on the classification of career shocks and developing a new dedicated theoretical model to help us understand the mechanisms underlying career shocks and their effects on career processes as well as behavioural outcomes more completely. Our study also has important practical implications for helping employees make sense of and prepare for career shocks; this research can also improve the ability of career counsellors and managers to help employees better cope with career shocks by avoiding their negative impacts, which is conducive to the long-term and stable development of organizations and employees.
Subjects: Psychology >> Social Psychology submitted time 2023-03-27 Cooperative journals: 《心理学报》
Abstract： Procedural motor learning includes sequence learning and random learning. Neuroimaging studies have shown that the dorsolateral prefrontal cortex (DLPFC) and primary motor cortex (M1) play significant roles in procedural motor learning; however, the connectivity between the DLPFC and M1 and its relationship with different procedural motor learning are still unclear. In this study, the serial response time task (SRTT) and transcranial magnetic stimulation (TMS) were used to explore the differences in left DLPFC-M1 connectivity between the different types of procedural motor learning. In experiment 1, dual-site paired-pulse TMS was used to detect the optimal interval from the DLPFC to the M1. In experiment 2, the participants were divided into two groups that underwent sequence learning or random learning. Behavioral data, motor evoked potentials from the M1 and electrophysiological data of DLPFC-M1 connectivity were assessed before and after learning. The behavioral results showed that the learning effect of the sequence learning group was better. The electrophysiological results showed that motor evoked potentials from the M1 were the same before and after learning in both groups. At the optimal interval and appropriate stimulation intensity, the DLPFC-M1 connectivity in the sequence learning group was changed, and it was related to learning performance; however that in the random learning group was not significantly changed. The results suggest that enhanced connectivity between the DLPFC and M1 may be an important explanation for the better performance in sequence learning. The results provide robust electrophysiological evidence for the role of DLPFC in motor learning.
submitted time 2023-03-25 Cooperative journals: 《心理科学进展》
Abstract： Uncertainties in the external environment are constant and difficult to predict in a world filled with VUCA (volatility, uncertainty, complexity, ambiguity; Bennett & Lemoine, 2014), which has caused career shocks to become an increasingly important part of current career scholarship. Akkermans et al. (2018) defined a career shock as “a disruptive and extraordinary event that is, at least to some degree, caused by factors outside the focal individual’s control and that triggers a deliberate thought process concerning one’s career” (p. 4). These authors suggested that the occurrence of a career shock can either be positively or negatively valenced (Akkermans et al., 2018); that is, positive career shocks are more likely to be associated with positive career outcomes, and negative shocks are more likely to be associated with negative outcomes. However, due to individual differences in the cognition of events or time factors, this categorization may have some shortcomings. We found that the literature includes several theoretical perspectives that have been or could be used to scaffold our understanding of the positive or negative impacts of career shocks, and a multiperspective model may provide evidence to support the reclassification of career shocks and help clarify the effects of career shocks. First, we found that the main reasons for the positive or negative effects of career shocks on employees’ behaviour can be explained in terms of different mechanisms and processes. More specifically, the transactional model of stress and coping, the job demands-resources model, and affective event theory could help elucidate how different cognitive, motivational and emotional responses to a career shock can influence the effects of such shocks on behavioural outcomes, those providing insights into the different processes by which shocks impact outcomes. Event system theory focuses on the characteristics or attributes of career shock events that make them salient and therefore likely to impact such outcomes, which could also help explain how their impacts can be extended over time as events vary in duration and timing or as event strength evolves. Second, based on the transactional model of stress and coping, the present study proposed a new classification of career shocks, namely, challenging career shocks and hindering career shocks. Third, we explored the mechanism underlying the impacts of challenging and hindering career shocks on individual behaviour based on the transactional model of stress and coping, the job demands-resources model, and affective event theory. We proposed that challenging career shocks are positively related to problem-focused coping, work engagement and positive affectivity and that hindering career shocks are positively related to emotion-focused coping, burnout and negative affectivity. Furthermore, the attributes (e.g., the strength) of events could moderate the effects of career shocks. Finally, we identify a number of avenues for future research, including developing the concept and attributes of career shock, enriching the empirical research on the new classification of career shocks, exploring additional mechanisms underlying career shocks, and examining the outcomes of career shocks. The present study contributes to the emerging career shock literature by providing a new perspective on the classification of career shocks and developing a new dedicated theoretical model to help us understand the mechanisms underlying career shocks and their effects on career processes as well as behavioural outcomes more completely. Our study also has important practical implications for helping employees make sense of and prepare for career shocks; this research can also improve the ability of career counsellors and managers to help employees better cope with career shocks by avoiding their negative impacts, which is conducive to the long-term and stable development of organizations and employees.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-19 Cooperative journals: 《金属学报》
Abstract： The effect of Hf on the as- cast, heat- treated microstructures and stress rupture properties under 1100 ℃ and 140 MPa was investigated in four second generation Ni-based single crystal superalloys DD11 with various levels of Hf (0~0.80%, mass fraction) additions. The results indicate that increasing Hf addition resulted in decreasing the solidus and liquidus temperatures, while it enhanced the volume fraction of (g +g') eutectic and MC carbide as well as solidification segregation. The number of micropores reduced significantly and the volume fraction of residual (g +g') eutectic and MC carbide increased after heat treatment as Hf content increased. Compared to the Hf-free alloy, the stress rupture life was observed to increase in the alloys with 0.40%Hf, but dropped in the alloy containing 0.80%Hf. Hf addition increased the elemental partitioning ratio of Re, Mo, Cr, resulting in increasing g /g' misfit and decreasing the spacing of g /g' interfacial dislocation networks. The solution strengthing effect was also improved with the enhanced concentration of Re, Mo and Cr in g phase in Hf-modified alloys. However, when the Hf content was 0.80% in DD11 alloy, the stress rupture properties was decreased obviously due to high volume fraction of residual (g +g') eutectic and MC carbide in heat-treated microstructures.
Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2022-12-23
Abstract：
Most previous studies agree that career shocks can be either positively (receiving an unexpected award) or negatively (unexpectedly losing one’s job) valenced. However, due to individual differences in the cognition of events or time factors, this categorization may have some shortcomings. Based on the transactional model of stress and coping, the present study proposes a new classification of career shocks, namely, challenging and hindering career shocks, and further explores the mechanism underlying the impacts of career shocks on individual behaviour based on the transactional model of stress and coping, the job demands-resources model, affective event theory, and event system theory; finally, the paper clarifies when and why career shocks have positive or negative impacts on employees.
Peer Review Status:
Awaiting Review
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-06-21 Cooperative journals: 《干旱区研究》
Abstract：干旱区湿地在改善地区生态环境，维护地区生态稳定等方面发挥着重要作用，研究干旱区湿地土壤碳（C）、氮（N）、磷（P）等元素的生态化学计量学特征，有助于深入了解干旱区湿地土壤养分的供给能力及循环与平衡机制。本文以河西走廊西段，疏勒河中下游的草本沼泽（T1）和季节性咸水沼泽（T2）土壤为研究对象，分析了这两种沼泽湿地土壤C、N、P生态化学计量学特征及其影响因素。结果表明：① 0～100 cm土壤C/N、N/P、C/P均为T2（15.07，5.94，98.01）＞T1（12.49，2.50，30.22）；随土层深度的增加，土壤C/N、N/P、C/P均在T1有两个峰值（0～10 cm和中间层），T2有一个峰值（中间层）。② 0～100 cm土壤C/N、N/P、C/P空间变异性大，且均为T2＞T1。③ T1和T2土壤的N/P与土壤水分呈极显著正相关（P<0.01），C/P与土壤水分、全N呈极显著正相关（P<0.01），与碱解N呈显著正相关（P<0.05）；T2土壤C/N、N/P、C/P与土壤容重呈极显著正相关（P<0.01），C/N与土壤水分呈极显著的正相关（P<0.01），N/P与土壤有机C呈显著正相关（P<0.05）；T1土壤N/P与土壤有机C呈极显著正相关（P<0.01）。④ 土壤水分是影响两种沼泽湿地土壤C、N、P计量比的关键因子。因此，保护干旱区湿地土壤关键在于采取合理的节水用水措施，该结果可为干旱区湿地土壤保护、管理以及生态恢复提供科学依据。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-06-19 Cooperative journals: 《干旱区研究》
Abstract：干旱区湿地在改善地区生态环境，维护地区生态稳定等方面发挥着重要作用，研究干旱区湿地土壤碳（C）、氮（N）、磷（P）等元素的生态化学计量学特征，有助于深入了解干旱区湿地土壤养分的供给能力及循环与平衡机制。本文以河西走廊西段，疏勒河中下游的草本沼泽（T1）和季节性咸水沼泽（T2）土壤为研究对象，分析了这两种沼泽湿地土壤C、N、P生态化学计量学特征及其影响因素。结果表明：① 0～100 cm土壤C/N、N/P、C/P均为T2（15.07，5.94，98.01）＞T1（12.49，2.50，30.22）；随土层深度的增加，土壤C/N、N/P、C/P均在T1有两个峰值（0～10 cm和中间层），T2有一个峰值（中间层）。② 0～100 cm土壤C/N、N/P、C/P空间变异性大，且均为T2＞T1。③ T1和T2土壤的N/P与土壤水分呈极显著正相关（P<0.01），C/P与土壤水分、全N呈极显著正相关（P<0.01），与碱解N呈显著正相关（P<0.05）；T2土壤C/N、N/P、C/P与土壤容重呈极显著正相关（P<0.01），C/N与土壤水分呈极显著的正相关（P<0.01），N/P与土壤有机C呈显著正相关（P<0.05）；T1土壤N/P与土壤有机C呈极显著正相关（P<0.01）。④ 土壤水分是影响两种沼泽湿地土壤C、N、P计量比的关键因子。因此，保护干旱区湿地土壤关键在于采取合理的节水用水措施，该结果可为干旱区湿地土壤保护、管理以及生态恢复提供科学依据。
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