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121.
Satellite remote sensing techniques can be used for conducting environmental change detection studies following a natural disaster. Modern computer technology and free access to global satellite imagery allows educators to introduce undergraduate students to the fields of remote sensing and encourage their scientific participation through a research assignment that also serves as an educational exercise. The undergraduate physical science laboratory manuals used in higher education that contain printed remote sensing material often fail to effectively achieve these goals. This class exercise utilizes digital satellite imagery for studying the floods that resulted in the Paraná River region in South America during El Niño 1997–98. In addition, it examines vegetation cover and spectral profiles from the study area in order to further understand and assess the changes that were caused by this recurrent climatic anomaly.  相似文献   
122.
The described interdisciplinary course helped a mixed population of in-service secondary English and biology teacher-participants increase their genetics content knowledge and awareness of Ethical, Legal, and Social Implications (ELSI) that arose from discoveries and practices associated with the Human Genome Project. This was accomplished by applying a critical literacy approach that allows people develop cognitive skills such that they are able to "read the world" (Wink, 2004). The approach is one that permits readers to go beyond the literal text to examine what is present as well as what is missing as it relates to issues of equity and fairness. Becoming critically literate enabled these teacher-participants to challenge the subtle attitudes, values, and beliefs conveyed by a range of written and oral texts. The teacher-participants in this course improved their critical literacy skills by actively reading, critically writing about, and using evidence to support their conclusions about issues arising from advances in human genetics. A biologist, a linguist, and an educator collaboratively designed and taught the course. The personalized focus on the integration of thoughtful reading and writing in this class enhanced the teacher-participants' (n = 16) professional and intellectual development and will potentially improve learning in their biology and English classrooms in the future.  相似文献   
123.
Two experiments evaluated history effects on induced and operant variability. College students typed three-digit sequences on a computer keyboard. Sequence variability was induced (by no reinforcement or variation- independent reinforcement) or reinforced (by variation- or repetition-dependent reinforcement). Conditions with induced and operant variability were presented according to a reverse between-groups design. In Experiment 1, we examined transitions from the variation or repetition contingencies to no reinforcement, and vice versa. In Experiment 2, the variation or repetition contingencies were followed or preceded by variation-independent reinforcement. The results showed that (1) a history of no reinforcement impaired operant variability learning; (2) induced variability levels were higher and lower after a history of reinforcement for variation and repetition, respectively; (3) repetition was more easily disrupted by no reinforcement and independent reinforcement than was variation; and (4) response variability and stability were a function of past and current reinforcement conditions. These results indicate that reinforcement history influences both induced and operant variability levels.  相似文献   
124.
The literature on trolling has viewed trolling as discrete instances of transgression undertaken by antagonistic individuals. We identify three main issues with current theorizations: diffuse definitions of “trolling,” blurred boundaries between trolling and other online anti-social behaviors, and the context dependency of trolling. To address these unresolved issues, we adopt a practice-based theoretical approach. Informed by this approach, we analyze trolling behaviors not as products of individuals' attitudes, values, and decisions, but rather as behaviors embedded within and occurring as part of social practices. Specifically, we conduct a practice-based theoretical analysis in a multi-site exploratory study involving online archival research and in-depth interviews with online community members. Based on this analysis, we propose that trolling be conceived as a constellation of three social practices: learning, assimilating, and transgressing. Also, we find that practices of trolling transgression can have a dual pro-social and anti-social impact in online communities.  相似文献   
125.
Supervised exercise has shown benefits for subjects with asthma, but little is known about the effectiveness of unsupervised physical activity on this population. We investigated the effects of a 12-week unsupervised pedometer-based physical activity program on daily steps and on clinical and psychological parameters of adults with asthma. Clinically stable adults with moderate to severe asthma were encouraged to take daily 30-minute walks and were randomized to pedometer and control groups. The pedometer group received pedometers and individualized daily step targets. Changes in daily steps (average of steps taken during six consecutive days), six-minute walk test (6MWT), health-related quality of life, asthma control and anxiety and depression levels were assessed 12 weeks after intervention and 24–28 weeks after randomization. Thirty-seven participants were recruited and 30 completed the intervention. At 12 weeks, the groups differed significantly in daily steps (adjusted average difference, 2488 steps; 95% confidence interval [CI], 803 to 4172; p = 0.005) and in the 6MWT (adjusted average difference, 21.9 m; 95% CI, 6.6 to 37.3; p = 0.006). These differences were not significant 24–28 weeks after randomization. The program was effective in increasing daily steps of adults with moderate to severe asthma 12 weeks after intervention.  相似文献   
126.
Change-of-direction (COD) ability is an essential physical component for soccer. This study examined the relationships between conventional speed–power assessments and COD performance in elite young soccer players. Twenty-five under-20 male players from the same club (age: 17.6?±?0.8 years, height: 178.1?±?6.7?cm, body mass [BM]: 72.2?±?7.9?kg) performed sprint speed tests, vertical jumps, loaded jump squats, half squats, and Zigzag COD assessments. Moreover, the COD deficit was calculated as the difference between 20-m sprint velocity and Zigzag COD test velocity. A Pearson correlation analysis was used to determine the correlations between Zigzag COD performance and COD deficit with speed and power outputs. Although no significant relationships between speed–power variables and COD ability were present, there were still strong positive correlations between traditional neuromechanical measures and COD deficit. Briefly, it seems that higher performances in speed and power tests are not necessarily related to better performances in specific COD maneuvers. Therefore, it is recommended that coaches and technical staff include specific COD drills in soccer player routines to optimize the transference from speed and power capacities to specific COD performance.  相似文献   
127.
128.
Abstract

The generality of the variability in practice prediction, arising from Schmidt's schema theory (1975) of motor learning was tested on young children. More specifically, the structure of the variability session and its subsequent influence on transfer performance to a novel variation of the task was examined. Children tossed a weighted bean bag to a fixed target location. Three groups experienced variability in practice with four bean bags of varying weights (3, 4, 5, and 6 oz.); however, the trial-by-trial presentation of each weight was different for each group. One group received a random presentation of each weight from trial to trial while another experienced random presentations of a weight for blocks of three trials. The third variability group received blocked practice with six trials per block for each weight. All variability groups experienced the same amount of practice at each weight. A constant practice group experienced only a single weight. Following 24 practice trials, all subjects transferred outside the range of previous experience, receiving three trials with one of two possible test weights (2 oz. or 7 oz.). The results indicated that the variability group practicing with blocks of three trials at each variation led to superior performance at transfer to novel variations of the task. Overall, the experiment suggested that transfer performance for children is affected by the appropriate structure of variable practice which formulates the schemata for movement production.  相似文献   
129.
130.
Spanish-speaking learners of French, aged 9 to 11 years old, were tested after approximately 7months of French instruction to explore the contribution of phonological and syntactic awareness in L2 in 4 components of L2 reading, taking oral competence in L2 andreading in L1 into account. Phonological tasksin L2 better explain decoding. Word recognitionthrough the visual route is best explained bythe corresponding ability in L1. Sentencecomprehension is best explained by oralcompetence in L2, although it is stronglycorrelated with syntactic awareness. Finally,text comprehension is explained by thecorresponding ability in L1, althoughcorrelations with syntactic awareness and oralcompetence are strong. Theoretical implicationsare derived from these findings, and questionsrelative to the subjects' age and level ofbilingualism as well as methodological issuesare discussed.  相似文献   
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