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421.
Male–male vocal competition in anuran species is critical for mating success; however, it is also highly time-consuming, energetically demanding and likely to increase predation risks. Thus, we hypothesized that changes in the social context would cause male vocal competition to change in real time in order to minimize the costs and maximize the benefits of competition. To test this hypothesis, we assessed the effect of repeating playbacks of either white noise (WN) or male advertisement calls on male call production in the Emei music frog (Babina daunchina), a species in which males build mud-retuse burrows and call from within these nests. Previous studies have shown that calls produced from inside burrows are highly sexually attractive (HSA) to females while those produced outside nests are of low sexual attractiveness (LSA). Results showed that most subjects called responsively after the end of WN playbacks but before the onset of conspecific call stimuli although call numbers were similar, indicating that while males adjusted competitive patterns according to the biological significance of signals, their competitive motivation did not change. Furthermore, these data indicate that the frogs had evolved the ability of interval timing. Moreover, when the inter-stimulus interval (ISI) between playbacks was varied, the subjects preferentially competed with HSA calls when the ISI was short (<4 s) but responded equally to HSA and LSA calls if the ISI was long (≥4 s), suggesting that males allocate competitive efforts depending on both the perceived sexual attractiveness of rivals and the time available for calling. Notably, approximately two-thirds of male calls occurred in response to HSA calls, a preference rate comparable to that previously found for females in phonotaxis experiments and consistent with the idea that the mechanisms underlying both the male’s competitive responses to rivals and the female’s preferences toward potential mates coevolved under the same selective pressure.  相似文献   
422.
Bilinguals have been shown to be less susceptible to Stroop interference in their first language than monolinguals, though the cause is currently being debated. In two experiments, we explored how cognitive control and word recognition contribute to the Stroop effect by contrasting cognitive control (via a Simon arrow task), word recognition speed (via a Chinese/English word recognition task) and Stroop susceptibility (via a verbal Stroop task) between proficient and non‐proficient Chinese–English bilinguals. Compared to non‐proficient bilinguals, proficient bilinguals showed better cognitive control at inhibiting irrelevant information, and they were slower at recognising Chinese words but quicker at recognising English words. Critically, we also showed that proficient bilinguals showed a smaller Stroop effect than non‐proficient bilinguals in Chinese but a comparable Stroop effect as non‐proficient bilinguals in English. The results cannot be accounted for by cognitive control or word recognition speed alone; instead, they are best accommodated by assuming that cognitive control and word recognition speed jointly determine the Stroop effect. Thus, we conclude that enhanced cognitive control and delayed word recognition combine to reduce Stroop effect in bilinguals as compared to monolinguals.  相似文献   
423.
Throughout life new neurons are generated in dentate gyrus of hippocampus. Previous studies have found that spatial tasks can rescue newly born neurons from death. However, it is still unknown whether new neurons are similarly affected by all types of hippocampal-dependent tasks. Here we investigated the possible effects of working memory task (WMT) on immature neurons. Mice were trained in reference memory task and WMT respectively. The reference memory task used the classical hidden platform (HP) water maze task, while WMT used a delayed matching-to-place (DMTP) water maze task. Bromodeoxyuridine (BrdU) was administrated during the early or late phase of training, or 1week prior to training, in order to label dividing proliferating cells. After water maze training, the number of BrdU-labeled cells in dentate gyrus of hippocampus was compared. In addition, hippocampal brain-derived neurotrophic factor (BDNF) and Notch 1 receptor were characterized using Western blot. Serum corticosterone levels were also measured using enzyme immunoassay. Results showed that HP task and DMTP task did not change the number of BrdU-labeled cells produced during the early or late phase of training. As expected, the HP task increased the number of BrdU-labeled cells produced 1 week prior to training. However, DMTP task decreased the number of BrdU-labeled cells produced 1 week prior to training. Both tasks lead to a significant increase in serum corticosterone levels and did not change the expression of BDNF and Notch 1 receptor in hippocampus. Taken together, these results demonstrate that WMT has different effects on survival of immature neurons, and therefore suggests immature neurons may have more than one role depending on the demands of the tasks.  相似文献   
424.
《萄子·王制篇》有《序官》一章,专门论述职官制度,通过对“乘白”、“乡师”、“州里”、“治市”、“治田”等条的考证.发现《序官》官制带有明显的齐国色彩。《序官》以及《王制篇》可能是苟子在齐国游学时所写。由于《王制》在齐国成书,当然为齐国学者所看到,《管子·立政》的作者为解决“国之贫”“五事”,所以《省官》一章有选择性地摘抄了《序官》“五官”。  相似文献   
425.
Before the developmental trajectory, outcomes, and related interventions of gratitude can be accurately and confidently studied among the youth, researchers must ensure that they have psychometrically sound measures of gratitude that are suitable for this population. Thus, considering that no known scales were specifically designed to measure gratitude in youth, this study aimed to answer an important question: Are the existing gratitude scales used with adults valid for use with youth? The present study is an empirical investigation, based on a large youth sample (N = 1,405) with ages ranging from 10 to 19 years old, of the psychometric properties of scores of the Gratitude Questionnaire-6 (GQ-6; M. E. McCullough, R. A. Emmons, & J.-A. Tsang, 2002), the Gratitude Adjective Checklist (GAC; M. E. McCullough, R. A. Emmons, & J.-A. Tsang, 2002), and the Gratitude Resentment and Appreciation Test (GRAT)-short form (M. Thomas & P. Watkins, 2003). Single-group and multiple-group confirmatory factor analyses indicated that the factor structures of these gratitude scales resemble those found with adults and were invariant across age groups. Scores of all three gratitude scales revealed acceptable internal consistency estimates (i.e., >.70) across age groups. Results showed that whereas scores of all three gratitude scales were positively correlated with each other for 14- to 19-year-olds, GRAT-short form scores tended to display relatively low correlations with scores of the other two measures for younger children (10-13 years old). Furthermore, the nomological network analysis showed that scores of all three gratitude scales were positively correlated with positive affect and life satisfaction scores across the age groups. The relationships with negative affect and depression scores, however, seemed dependent on the child's age. Pending results from subsequent research recommendations for researchers interested in studying gratitude in youth are offered.  相似文献   
426.
Previous studies suggest that aging is associated with impairment of attention. However, it is not known whether this represents a global attentional deficit or relates to a specific attentional network. We used the attention network test to examine three groups of younger, middle-aged, and older participants with respect to the efficiency of three anatomically defined attentional networks: alerting network, orienting network, and executive control network. Age-related change was found to have the greatest effect on the executive network and the least effect on the alerting network as well as on overall mean response time. Impairment of the orienting network was found to be insignificant. Age-related deterioration of the prefrontal lobe, the dopaminergic system, and function of specific genes may explain the age-related changes in executive attention, which occur after the fourth decade of life.  相似文献   
427.

Purpose  

Social cynicism, defined as negative beliefs about people and social institutions, shows negative impact on people’s affective reactions. We extended this line of work by testing the moderating effects of social cynicism on the relationships between relationship conflict and its affective consequences.  相似文献   
428.
“技术认识”解析   总被引:1,自引:0,他引:1  
要阐明技术认识论的性质、内容和理论系统,必须从技术认识开始,这是研究技术认识论的基点。明确技术认识的一个前提是准确把握什么是技术,澄清技术认识与非技术认识的界限,以此为基础才能明确什么是技术认识。一、技术与技术认识  相似文献   
429.
自我设限是指个体针对可能到来的失败威胁而事先设置障碍,以达到自我保护或自我提升的目的,是一种消极的应对方式。自我设限在学业中的具体体现就是学业自我设限。中学生学习负担重,心理压力大,学业自我设限行为较为普遍。下文所述的自我设限的行为表现、不良后果和干预策略旨在为学校教育提供科学信息,帮助自我设限的学生走出学业困境,从容的应对学习中的困难和挑战。  相似文献   
430.
The authors propose a new procedure for reducing faking on personality tests within selection contexts. This computer-based procedure attempts to identify and warn potential fakers early on during the testing process and then give them a chance for recourse. Two field studies were conducted to test the efficacy of the proposed procedure. Study 1 participants were 157 applicants competing for 10 staff positions at a large university located in a southern city in the People's Republic of China. In Study 1, potential fakers received a warning message, whereas nonfakers received a nonwarning (control) message. Study 2 participants were 386 Chinese college students applying for membership of a popular student organization at the same university where Study 1 was conducted. In Study 2, the warning and control messages were randomly assigned to all applicants. Results showed some promise for the proposed procedure, but several practical issues need to be considered.  相似文献   
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