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51.
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Men who had high-risk sex with men in the previous year ( N = 124) were asked to recall their thought processes at the time they last had unprotected anal sex with a man who was HIV-positive or of unknown serostatus. Self-justifications for non-condom use were examined individually and in internally validated scales. The most common single self-justification was I want to have unprotected sex because it feels good , endorsed by 76%. Other common thoughts included the notion that it is only human to slip up occasionally (59%) and the resolution to withdraw before ejaculation (59%). For scaled items, the most strongly endorsed themes were: (1) that condoms reduce sexual pleasure (any of 6 items endorsed at least slightly by 90%); (2) fatalism or leaving it to chance (11 items, 81%); and (3) loss of control (9 items, 77%). The thoughts and themes identified may be useful in planning individual and community prevention messages.  相似文献   
53.
Palma  Cândida  Santos  Raquel 《Studia Logica》2001,67(1):75-88
In this paper we use Hobby's duality for semi-De Morgan algebras, to characterize those algebras having only principal congruences in the classes of semi-De Morgan algebras, demi-pseudocomplemented lattices and almost pseudocomplemented lattices. This work extends some of the results reached by Beazer in [3] and [4].  相似文献   
54.
    
How does the act of explaining influence learning? Prior work has studied effects of explaining through a predominantly proximal lens, measuring short-term outcomes or manipulations within lab settings. Here, we ask whether the benefits of explaining extend to academic performance over time. Specifically, does the quality and frequency of student explanations predict students’ later performance on standardized tests of math and English? In Study 1 (N = 127 5th−6th graders), participants completed a causal learning activity during which their explanation quality was evaluated. Controlling for prior test scores, explanation quality directly predicted both math and English standardized test scores the following year. In Study 2 (N = 20,384 10th graders), participants reported aspects of teachers’ explanations and their own. Controlling for prior test scores, students’ own explanations predicted both math and English state standardized test scores, and teacher explanations were linked to test performance through students’ own explanations. Taken together, these findings suggest that benefits of explaining may result in part from the development of a metacognitive explanatory skill that transfers across domains and over time. Implications for cognitive science, pedagogy, and education are discussed.  相似文献   
55.
The paper retraces the elaboration of a model that accounts for the emergence of subjectivity-the possibility to distance self from others and oneself-if we consider people as always taken in social and cultural streams of meaning and tensions. It builds a model considering first, human experience as possible when a person takes distance from the here-and-now. Second, it suggests considering two general semiotic streams that feed in, or support, that distancing-social and cultural discourses, and personal experience. Third, a knitting model suggests the constant creation of personal patters out of these two streams. Fourth, a dynamic, star-like model is proposed to account for the actual and constant emergence of subjectivity out of such social and cultural configurations. The model is constituted by a 2, 3 or N-number of eight-shaped crossing loops, resulting in a star-like model situated in a 3 dimensional space. The proposition is to analyze a person in a specific situation: the attractors enabling these loops, or end-points of the star, are the relevant social and cultural elements: others with whom he or she interacts, specific bodies of shared knowledge, social representations, cultural elements and tools, and so on. In each situation, the relative strength of these elements, or the tension they generate, are negotiated by the person; the unique ways of dealing with that situation and inviting solutions can thus be seen as the emergent subjectivity. The model is explored to account for developmental dynamics at various scales in the lifecourse. Finally, the pragmatic interest of a model emphasizing complex configurations, not simple causalities, is recalled.  相似文献   
56.

Background and objective

Field invasion games, such as rugby union, can be conceptualised as dynamic social systems in which the agents continuously interact to contest ball possession and territorial gain. Accordingly, this study aimed to identify the collective system dynamics of rugby union phases-of-play near the try line by investigating whether ball displacement trajectory on the playing field provides insights on successful team performance.

Methods

Five rugby union matches were videotaped involving teams at a national league performance level. From these matches, 22 second phases-of-play were selected and digitized for analysis. The variable “distance gained” was investigated as a potential coordination variable describing functional coordination between players and teams. This variable concerned the distance between ball initial position and ball current position over time and was used to define the degree of territory gained by an attacking team.

Results

Analysis of distance gained dynamics in attacking sub-phases demonstrated the intermittent character of rugby union performers displacement trajectories on the playing field. Amplitude of ball movements was revealed as a distinguishing feature related to attacking effectiveness. Successful attacking phases displayed lower distances of positional retreat, with the maximum retreat distance achieved sooner in successful compared to unsuccessful phases-of-play. Autocorrelation and ApEn analyses suggested low system variability within time series data concerning both performance outcomes. However, evidence of less regularity and more complexity was found in unsuccessful phases-of-play.

Conclusion

Results suggested that distance gained dynamics manifests a characteristic collective behaviour pattern that captures the macroscopic functional order of multi-player attack–defence systems in team sports like rugby union.  相似文献   
57.
The present study investigated how European adolescents cope with perceived future-related stress. Altogether 3,154 adolescents (mean age of 15 years) from four countries (n = 1,071 Italians, n = 1,433 Germans, n = 308 French, and n = 341 British) participated in the study. They completed the Problem Questionnaire, which assesses future-related stress, and the CASQ, which assesses how three coping styles (active coping, internal coping, and withdrawal) are used to deal with future-related stress. German and British adolescents showed low levels of stress, whereas French and Italian adolescents had high levels. All adolescents anticipated future-related problems but did not portray their futures negatively. In addition, they dealt with future-related stress actively and showed high levels of coping competence. Adolescents used active coping strategies most frequently, followed by thinking about possible solutions. Dysfunctional coping strategies (e.g., withdrawal) were used much less often. The effects of age, gender, and family variables on stress perception and coping style were negligible. Overall, our findings highlight the tenets of positive psychology by revealing that adolescents are concerned about their futures and that they show high agency in dealing with future-related problems. Further, the findings are relevant for positive youth development programs, especially those which endorse positive orientation to the future and coping competence.  相似文献   
58.
This is a normative study with 409 adult nonpatients living in the state of Sao Paulo, Brazil. The Rorschach was administered by a team of nine psychologists; eight had had further training in the Rorschach method by the Brazilian Rorschach Society and one intensively was prepared by the project coordinator. Of the study participants, 200 lived in the state capital (Sao Paulo) and the other 209 were in other large and small cities in the state, including a coastal city and one in the mountains. Previous psychological or psychiatric treatments were criteria for exclusion. Each protocol was coded independently by two examiners, and then agreement of the two codings was checked. Differences between the two codings were discussed in a meeting of the whole team, which was supervised by the project coordinator to guarantee codification quality control. Upon completion of the codings, an analysis of examiner differences was undertaken, the results of which are in the text. Interrater reliability statistics among examiners were calculated, including percentage of agreement and kappa. Reliability statistics among examiners at the response level are presented as are Comprehensive System (CS; 1999, 2003) findings.  相似文献   
59.
Fundamental physics makes no clear use of causal notions; it uses laws that operate in relevant respects in both temporal directions and that relate whole systems across times. But by relating causation to evidence, we can explain how causation fits in to a physical picture of the world and explain its temporal asymmetry. This paper takes up a deliberative approach to causation, according to which causal relations correspond to the evidential relations we need when we decide on one thing in order to achieve another. Tamsin's taking her umbrella is a cause of her staying dry, for example, if and only if her deciding to take her umbrella for the sake of staying dry is adequate grounds for believing she'll stay dry. This correspondence explains why causation matters: knowledge of causal structure helps us make decisions that are evidence of outcomes we seek. The account also explains why we can control the future and not the past, and why causes come before their effects. When agents properly deliberate, their decisions can never count as evidence for any outcomes they may seek in the past. From this it follows that causal relations don't run backwards. This deliberative asymmetry is itself traced back to asymmetries of evidence and entropy, providing a new way of deriving causal asymmetry from temporally symmetric laws.  相似文献   
60.
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