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Woei Hung 《Educational technology research and development : ETR & D》2011,59(4):529-552
The success of an intervention depends not only upon its theoretical soundness, but also on proper implementation that reflects
the guidelines derived from its theoretical conception. Debates surrounding the effectiveness of problem-based learning (PBL)
have focused on its theoretical conception and students’ learning outcomes, but implementation is seemingly absent from the
picture. This paper attempts to describe what research evidence is needed to fill in this missing information and provide
a clearer picture of PBL. The author examines current PBL implementation practices and identifies potentially confounding
variables that may play a role in inconsistent or conflicting research results in PBL. For example, various models of PBL
have been developed and implemented to afford the specific instructional needs of the institution or learner population. These
PBL models are in fact quite different in terms of the nature of problem solving and the degrees of self-directed learning,
which theoretically, should result in different types of learning outcomes. Without distinguishing the models used, the results
of comparative PBL research could have been confounded. Furthermore, human factors are another set of confounding variables
that could influence the students’ learning processes and consequently affect PBL implementations and research results. To
remedy these problems and reach PBL’s full potential, as well as obtain a more accurate picture of PBL as an instructional
method and its effects on students’ learning, some fundamental changes are needed. 相似文献
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The present study examined the role of verbal working memory (memory span and tongue-twister), two-character Chinese pseudoword reading (two tasks), rapid automatized naming (RAN) (letters and numbers), and phonological segmentation (deletion of rimes and onsets) in inferential text comprehension in Chinese in 31 less competent comprehenders compared with 37 reading comprehension control students and 23 chronological age controls. It was hypothesized that the target students would perform poorly on these cognitive and linguistic tasks as compared with their controls. Furthermore, verbal working memory and pseudoword reading would explain a considerable amount of individual variation in Chinese text comprehension. RAN would have a nonsignificant role in text comprehension. Structural equation analyses and hierarchical multiple regression analyses generally upheld these hypotheses. Our findings support current literature of the role of verbal working memory in reading comprehension found in English. The results, however, suggest differential role of the constructs and the tasks in reading comprehension and provide some answers for comprehension impairment in Chinese students. 相似文献
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Yu-Jui Che Huei-Wen Wu Lien-Yu Hung Ching-Ann Liu Hwan-You Chang Kuan Wang Gwo-Bin Lee 《Biomicrofluidics》2015,9(5)
Affinity reagents recognizing biomarkers specifically are essential components of clinical diagnostics and target therapeutics. However, conventional methods for screening of these reagents often have drawbacks such as large reagent consumption, the labor-intensive or time-consuming procedures, and the involvement of bulky or expensive equipment. Alternatively, microfluidic platforms could potentially automate the screening process within a shorter period of time and reduce reagent and sample consumption dramatically. It has been demonstrated recently that a subpopulation of tumor cells known as cancer stem cells possess high drug resistance and proliferation potential and are regarded as the main cause of metastasis. Therefore, a peptide that recognizes cancer stem cells and differentiates them from other cancer cells will be extremely useful in early diagnosis and target therapy. This study utilized M13 phage display technology to identify peptides that bind, respectively, to colon cancer cells and colon cancer stem cells using an integrated microfluidic system. In addition to positive selection, a negative selection process was integrated on the chip to achieve the selection of peptides of high affinity and specificity. We successfully screened three peptides specific to colon cancer cells and colon cancer stem cells, namely, HOLC-1, HOLC-2, and COLC-1, respectively, and their specificity was measured by the capture rate between target, control, and other cell lines. The capture rates are 43.40 ± 7.23%, 45.16 ± 7.12%, and 49.79 ± 5.34% for colon cancer cells and colon cancer stem cells, respectively, showing a higher specificity on target cells than on control and other cell lines. The developed technique may be promising for early diagnosis of cancer cells and target therapeutics. 相似文献
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In this paper, we develop themes from complexity and chaos theory that help to explain the technological change process. We apply two quantifiers, correlation dimensions and Lyapunov exponents, to examine the signs and degrees of chaotic technological dynamics. To illustrate our ideas, we study the development of electronic displays from 1976 to 2010, using patent data. The results of the chaos model are matched against the profiles of patent citations. Our analysis contributes to the development of a chaotic model of technological change. 相似文献
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对21世纪我国高校网球热的预测 总被引:15,自引:0,他引:15
网球运动历史悠久,是世界上开展得十分广泛且深受人们喜爱的一项体育运动。随着我国改革开放的深入,人民生活水平的提高,网球运动逐渐普及,以其固有的价值和魅力,受到大学生们的青睐,在21世纪我国高校将掀起网球热。本文较详细地阐述了掀起网球热的理由。 相似文献