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11.
The Effects of Work Intensity on Adolescent Mental Health, Achievement, and Behavioral Adjustment: New Evidence from a Prospective Study 总被引:3,自引:0,他引:3
Jeylan T. Mortimer Michael D. Finch Seongryeol Ryu Michael J. Shanahan Kathleen T. Call 《Child development》1996,67(3):1243-1261
This article examines the effects of work intensity on adolescent mental health, academic achievement, and behavioral adjustment. Questionnaire data were collected yearly from an initial panel of 1,000 randomly selected ninth graders (14-15 years old). Consistent with other studies, students who worked at higher intensity engaged in more alcohol use. The methodological strengths of this research (a representative panel studied prospectively over a 4-year period with minimal attrition and an analysis incorporating key control and lagged variables) provide strong evidence that adolescent work fosters alcohol use. The contention that work of high intensity has deleterious effects on mental health, academic achievement, and 2 other indicators of behavioral adjustment did not withstand our stringent tests. However, high school seniors who worked at moderate intensity (1-20 hours per week) had higher grades than both nonworkers and students who worked more hours per week. 相似文献
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The Influence of James C. McCroskey’s Research in South Korea 总被引:1,自引:1,他引:0
In honor and remembrance of Dr. James C. McCroskey, this article looks at McCroskey’s influence in Korean academic fields. We find that McCroskey’s scholarly articles and books were increasingly cited from 2001 to 2016 and that his work has been cited in Korean journals across diverse fields. In addition to the communication and education fields, McCroskey was cited also in the fields of science and medicine in South Korea. The findings document the international and interdisciplinary impact of McCroskey’s scholarship. 相似文献
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We present a multigroup multilevel confirmatory factor analysis (CFA) model and a procedure for testing multilevel factorial invariance in n-level structural equation modeling (nSEM). Multigroup multilevel CFA introduces a complexity when the group membership at the lower level intersects the clustered structure, because the observations in different groups but in the same cluster are not independent of one another. nSEM provides a framework in which the multigroup multilevel data structure is represented with the dependency between groups at the lower level properly taken into account. The procedure for testing multilevel factorial invariance is illustrated with an empirical example using an R package xxm2. 相似文献
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柳昌娇 《南阳师范学院学报》2010,9(2):112-118
文章介绍韩国大学教学《中国文学史》的实际情况,大体反映了韩国大学一般的教学特点,包括教学目标,教学意义,教材与教学内容,教学方法与评价方法等。文章也有实际具体教案可参考。 相似文献
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Myungjin Jung Liye Zou Jane Jie Yu Seungho Ryu Zhaowei Kong Lin Yang Minsoo Kang Jingyuan Lin Hong Li Lee Smith Paul D. Loprinzi 《运动与健康科学(英文)》2020,9(6):562-577
ObjectiveThis study aimed to examine (1) the independent effects of hypoxia on cognitive function and (2) the effects of exercise on cognition while under hypoxia.MethodsDesign: Systematic review with meta-analysis. Data sources: PubMed, Scopus, Web of Science, PsychInfo, and SPORTDiscus were searched. Eligibility criteria for selecting studies: randomized controlled trials and nonrandomized controlled studies that investigated the effects of chronic or acute exercise on cognition under hypoxia were considered (Aim 2), as were studies investigating the effects of hypoxia on cognition (Aim 1).ResultsIn total, 18 studies met our inclusionary criteria for the systematic review, and 12 studies were meta-analyzed. Exposure to hypoxia impaired attentional ability (standardized mean difference (SMD) = –0.4), executive function (SMD = –0.18), and memory function (SMD = –0.26), but not information processing (SMD = 0.27). Aggregated results indicated that performing exercise under a hypoxia setting had a significant effect on cognitive improvement (SMD = 0.3, 95% confidence interval: 0.14 – 0.45, I2 = 54%, p < 0.001). Various characteristics (e.g., age, cognitive task type, exercise type, exercise intensity, training type, and hypoxia level) moderated the effects of hypoxia and exercise on cognitive function.ConclusionExercise during exposure to hypoxia improves cognitive function. This association appears to be moderated by individual and exercise/hypoxia-related characteristics. 相似文献
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A group recommendation system for online communities 总被引:1,自引:0,他引:1
Jae Kyeong Kim Hyea Kyeong Kim Hee Young Oh Young U. Ryu 《International Journal of Information Management》2010
Online communities are virtual spaces over the Internet in which a group of people with similar interests or purposes interact with others and share information. To support group activities in online communities, a group recommendation procedure is needed. Though there have been attempts to establish group recommendation, they focus on off-line environments. Further, aggregating individuals’ preferences into a group preference or merging individual recommendations into group recommendations—an essential component of group recommendation—often results in dissatisfaction of a small number of group members while satisfying the majority. To support group activities in online communities, this paper proposes an improved group recommendation procedure that improves not only the group recommendation effectiveness but also the satisfaction of individual group members. It consists of two phases. The first phase was to generate a recommendation set for a group using the typical collaborative filtering method that most existing group recommendation systems utilize. The second phase was to remove irrelevant items from the recommendation set in order to improve satisfaction of individual members’ preferences. We built a prototype system and performed experiments. Our experiment results showed that the proposed system has consistently higher precision and individual members are more satisfied. 相似文献
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This article characterizes “engagement in science learning” from a sociocultural perspective and offers a mixed method approach to measuring engagement that combines critical discourse analysis (CDA) and social network analysis (SNA). Conceptualizing engagement from a sociocultural perspective, the article discusses the advantages of a mixed methodological approach, and specifically how mixed methods can expand and enrich our understanding of engagement in certain science learning situations. Through this sociocultural viewpoint, engagement is defined as meaningful changes in disciplinary discourse practice, which captures the dialectical relationship between the individual and collective. The combined use of CDA and SNA integrates an individual's relative position in a group with her situated language use. 相似文献
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Understanding the mechanism behind cancer metastasis is a major challenge in cancer biology. Several in vitro models have been developed to mimic a cancer microenvironment by engineering cancer–endothelial cell (EC) and cancer-stromal cell interactions. It has been challenging to realistically mimic angiogenesis, intravasation, and extravasation using macro-scale approaches but recent progress in microfluidics technology has begun to yield promising results. We present a metastasis chip that produce microvessels, where EC and stromal cells can be patterned in close proximity to tumor cells. The vessels are formed following a natural morphogenic process and have smooth boundaries with proper cell-cell junctions. The engineered microvessels are perfusable and have well-defined openings toward inlet and outlet channels. The ability to introduce cancer cells into different locations bordering to the microvessel wall allowed generation and maintenance of appropriate spatial gradients of growth factors and attractants. Cancer angiogenesis and its inhibition by anti-vascular endothelial growth factor (bevacizumab) treatment were successfully reproduced in the metastasis chip. Cancer intravasation and its modulation by treatment of tumor necrosis factor-α were also modeled. Compared to other models, the unique design of the metastasis chip that engineers a clear EC-cancer interface allows precise imaging and quantification of angiogenic response as well as tumor cell trans-endothelial migration. The metastasis chip presented here has potential applications in the investigation of fundamental cancer biology as well as in drug screening. 相似文献
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KIM Chong-Min WON Chung-In RYU Joonghyun CHO Cheol-Hyung BHAK Jonghwa KIM Deok-Soo 《浙江大学学报(A卷英文版)》2006,7(9):1492-1499
INTRODUCTION Being the bio era, a significant research effort has been devoted to the study of proteins since they are related to the critical body functions. There have been many studies on proteins, with the voluminous related data being currently available in various pub- lic repositories including the Protein Data Bank (PDB) (CATH, 2006; DALI, 2006; MSD, 2006; RCSB PDB, 2006; SCOP Database, 2006). Given the atomic complexes of proteins, ana- lyzing interactions between them… 相似文献