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Many students have a deep interest in astronomy, but a limited opportunity to use telescopes to explore the heavens. The MicroObservatory Network of automated telescopes is designed to provide access to classroom teachers who wish their students to conduct projects over the World Wide Web. The intuitive interface makes it easy for even 10-year-olds to take pictures. Telescopes can be remotely pointed and focused: filters, field of view, and exposure times can be changed easily. Images are archived at the website, along with sample challenges and a user bulletin board, all of which encourage collaboration among schools. Wide geographic separation of instruments provides access to distant night skies during local daytime. Since first light in 1995, we have learned much about remote troubleshooting, designing for unattended use, and for acquiring the kinds of images that students desire. This network can be scaled up from its present capability of 240,000 images each year to provide telescope access for all US students with an interest in astronomy. Our WWW address is http://mo-www.harvard.edu/MicroObservatory/  相似文献   
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The evaluation plan arid preliminary results are reported for the ATS‐6 Satellite interactive telecommunication program for teaching at sites remote from an established medical school. The technical aspects of the system were seen as quite adequate and did not appear to substantially inhibit interaction. In the Fairbanks broadcasts analyzed, the average number of interactions ranged from 1.49 to 2.60 per minute. Ninety percent of the interaction flowed across the Satellite during Omak transmissions. Participants tended to initiate communication when they were on camera rather than when viewing their counterparts. Omak participants directed a higher percentage of the communication in student/resident programs (70%) than in faculty continuing education programs (59%). Interaction analysis indicated the categories of giving opinion, information, and suggestion were most frequent. Asking for opinion and suggestion occurred infrequently. The most frequent emotional expression was offering solidarity (e.g., reassurance), while there were exceedingly few expressions of disagreement, tension and antagonism. User acceptance of the system was determined to be very high. Participants with frequent exposure to the Satellite modality tended to have positive reaction. A significant difference in knowledge gain is reported in one of two basic science areas taught via Satellite as compared to regular instruction.  相似文献   
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Roy Corden 《Literacy》1998,32(3):27-31
In this article Roy Corden explores the view that the meaning of text is something readers construct by talking their way into. He illustrates some of the potential of appropriate, focused and well managed collaborative learning situations where children use their spoken language to develop literary skills and their awareness of language.  相似文献   
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Museums, art galleries, botanical gardens, national parks, science centers, zoos, aquaria and historic sites are important public learning institutions. The free‐choice learning offered in these settings is closely linked to visitors' intrinsic motivation, making it important to understand the motivational factors that impact on visitors' experiences. This paper presents data from a questionnaire administered to visitors at three sites: a museum, an art gallery, and an aquarium. Similarities and differences among the sites are reported in relation to visitors' expectations, perceptions of learning opportunities, engagement in motivated learning behaviors, and perceptions of the learning experience. The importance of learning to museum visitors and the unique opportunities and challenges of the museum in relation to other educational leisure settings are discussed. The authors argue that the study of motivational factors might contribute to the development of a common theoretical foundation for interpretation in museums and other informal learning settings.  相似文献   
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Cardiometabolic syndrome is one of the major public health issues of this century which describes a cluster of clinical characteristics. Seventy two patients with coronary artery disease (CAD) and cardiometabolic syndrome and forty healthy age and sex matched normal controls were selected for this study. Detailed clinical epidemiological and anthropometric characteristics were noted. Lipid profile and Cytokinesis-block micronuclei (CBMN) assay using cytochalasin B were carried out in all the subjects. Serum total cholesterol, triglyceride and LDL-cholesterol was significantly higher and HDL cholesterol was significantly lower in patients compared to their normal counter-parts (P<0.05). CBMN frequency of the patients was significantly higher at all ages compared to their normal counter parts (P<0.05). Various risk factors like diabetes, hypertension, dyslipidemia, abdominal obesity, smoking and alcoholism were found influenced the CBMN frequency; but the changes were not significant. From this study it can be concluded that DNA damage was found to be higher in patients with cardiometabolic syndrome which may be attributed to the generation of free radicals associated with alcohol consumption, tobacco use, dyslipidemia and glucose intolerance and the accumulation of free radicals with increase in age.  相似文献   
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We propose a novel form of nonlinear stochastic filtering based on an iterative evaluation of a Kalman-like gain matrix computed within a Monte Carlo scheme as suggested by the form of the parent equation of nonlinear filtering (Kushner–Stratonovich equation) and retains the simplicity of implementation of an ensemble Kalman filter (EnKF). The numerical results, presently obtained via EnKF-like simulations with or without a reduced-rank unscented transformation, clearly indicate remarkably superior filter convergence and accuracy vis-à-vis most available filtering schemes and eminent applicability of the methods to higher dimensional dynamic system identification problems of engineering interest.  相似文献   
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