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91.
Private organizations and public sector regarding child welfare services have been two main actors in improving the quality of children ’s lives. In this paper, the author examines two cases of childre... 相似文献
92.
Inertial microfluidics is an emerging class of technologies developed to separate circulating tumor cells (CTCs). However, defining design parameters and flow conditions for optimal operation remains nondeterministic due to incomplete understanding of the mechanics, which has led to challenges in designing efficient systems. Here, we perform a parametric study of the inertial focusing effects observed in low aspect ratio curvilinear microchannels and utilize the results to demonstrate the isolation of CTCs with high purity. First, we systematically vary parameters including the channel height, width, and radius of curvature over a wide range of flow velocities to analyze its effect on size dependent differential focusing and migration behaviors of binary (10 μm and 20 μm) particles. Second, we use these results to identify optimal flow regimes to achieve maximum separation in various channel configurations and establish design guidelines to readily provide information for developing spiral channels tailored to potentially arbitrary flow conditions that yield a desired equilibrium position for optimal size based CTC separation. Finally, we describe a fully integrated, sheath-less cascaded spiral microfluidic device to continuously isolate CTCs. Human breast cancer epithelial cells were successfully extracted from leukocytes, achieving 86.76% recovery, 97.91% depletion rate, and sustaining high viability upon collection to demonstrate the versatility of the device. Importantly, this device was designed without the cumbersome trail-and-error optimization process that has hindered the development of designing such inertial microfluidic systems. 相似文献
93.
94.
Associative classification methods have been recently applied to various categorization tasks due to its simplicity and high accuracy. To improve the coverage for test documents and to raise classification accuracy, some associative classifiers generate a huge number of association rules during the mining step. We present two algorithms to increase the computational efficiency of associative classification: one to store rules very efficiently, and the other to increase the speed of rule matching, using all of the generated rules. Empirical results using three large-scale text collections demonstrate that the proposed algorithms increase the feasibility of applying associative classification to large-scale problems. 相似文献
95.
Techniques used to prepare clinical samples have been perfected for use in diagnostic testing in a variety of clinical situations, e.g., to extract, concentrate, and purify respiratory virus particles. These techniques offer a high level of purity and concentration of target samples but require significant equipment and highly trained personnel to conduct, which is difficult to achieve in resource-limited environments where rapid testing and diagnostics are crucial for proper handling of respiratory viruses. Microfluidics has popularly been utilized toward rapid virus detection in resource-limited environments, where most devices focused on detection rather than sample preparation. Initial microfluidic prototypes have been hindered by their reliance on several off-chip preprocessing steps and external laboratory equipment. Recently, sample preparation methods have also been incorporated into microfluidics to conduct the virus detection in an all-in-one, automated manner. Extraction, concentration, and purification of viruses have been demonstrated in smaller volumes of samples and reagents, with no need for specialized training or complex machinery. Recent devices show the ability to function independently and efficiently to provide rapid, automated sample preparation as well as the detection of viral samples with high efficiency. In this review, methods of microfluidic sample preparation for the isolation and purification of viral samples are discussed, limitations of current systems are summarized, and potential advances are identified. 相似文献
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97.
Susan Yoon 《科学教学研究杂志》2008,45(8):900-921
This study investigated seventh grade learners' decision making about genetic engineering concepts and applications. A social network analyses supported by technology tracked changes in student understanding with a focus on social and conceptual influences. Results indicated that several social and conceptual mechanisms potentially affected how and why ideas were taken up in the learning system of the classroom. Mechanisms included copying or memetic processes such as “do as the smart students do” and friendship selection. Study outcomes are compared with the broader literature on memes and memetic processes to reveal general evolutionary ideas such as the development of prestige, identity versus problem‐solving strategies, extended phenotypes, and memeplexes. Educational implications for this research are also addressed. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 900–921, 2008 相似文献
98.
Since 2001, the issue of the low ratio of women faculty in universities has been prominent in Korea because of its negative
impact on female students and gender equality at the university level that has affected human resource development and utilization
at the national level. To address this issue, the Korean government developed and executed an education policy, the Policy
on Women Faculty Increase (PWFI) from 2004 to 2006. This paper investigated reactions to the PWFI and changes made as a result
of the policy in the conservative Korean higher education context. We found that although the PWFI has particularly contributed
to increasing the representativeness of women faculty in areas in which women faculty used to be rare, overall the PWFI has
not made significant improvements in most participating universities due to the lack of internal motives and drivers and effective
systems to support the policy. Recommendations for improvements in the policy are offered. 相似文献
99.
To test the hypothesis that biological motion perception is developmentally integrated with important social cognitive abilities, 12-month-olds ( N = 36) were shown a display of a human point-light figure turning to observe a target. Infants spontaneously and reliably followed the figure's "gaze" despite the absence of familiar and socially informative features such as a face or eyes. This suggests that biological motion displays are sufficient to convey rich psychological information such as attentional orientation and is the first evidence to show that biological motion perception and social cognitive abilities are functionally integrated early in the course of typical development. The question of whether common neural substrates for biological motion perception and analysis of gaze direction underlies the functional integration seen behaviorally is discussed. 相似文献
100.
This study explored an expanded definition and motivations for binge-watching behavior. In addition to the number of episodes, the amount of time, frequency, and engagement in binge-watched programs were considered for the binge-watching definition. Study findings revealed that over half of the respondents of this study were light binge viewers. In addition, among a total of seven motivations identified in literature, only the entertainment motivation is a significant predictor of binge watching for those with a low level of binge watching, while both passing time and entertainment were found to be significant predictors for those with a high level of binge watching. 相似文献