排序方式： 共有37条查询结果，搜索用时 15 毫秒
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Amna Khan Farzana Hayat Ahmad Muhammad Muddassir Malik 《Education and Information Technologies》2017,22(6):2767-2804
This study aimed to identify the impact of a game based learning (GBL) application using computer technologies on student engagement in secondary school science classrooms. The literature reveals that conventional Science teaching techniques (teacher-centered lecture and teaching), which foster rote learning among students, are one of the major concerns in Pakistan Education system. This leads to student disengagement in science lessons eventually resulting in student absenteeism and dropouts from the schools. This study consisted of five stages: (1) examining the impact of Digital Game-Based Learning (DGBL) and gamification on engagement, learning and gender difference, and literature related to using DGBL models for instructional design; (2) planning learning activities and developing a GBL application based on a specific content in Science; (3) conducting an intervention with a sample of 72 participants of 8th grade (aged 12–15) in a low cost private school of Pakistan following quasi-experimental research framework; (4) observing behaviour and emotions of the participants during science lessons; (5) conducting pre and post tests to assess the learning outcomes of participants followed by focus groups discussion. Analysis from Friedman test, Mann-Whitney U test, and Wilcoxon Signed Rank test show that the GBL application has a positive influence on student engagement. However, GBL application was not equally effective for all students since girls outperformed boys in terms of engagement and learning outcomes. This study gives insights into the development of better educational games to promote student learning. 相似文献
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Empirical modeling of the score distributions associated with retrieved documents is an essential task for many retrieval
applications. In this work, we propose modeling the relevant documents’ scores by a mixture of Gaussians and the non-relevant
scores by a Gamma distribution. Applying Variational Bayes we automatically trade-off the goodness-of-fit with the complexity
of the model. We test our model on traditional retrieval functions and actual search engines submitted to TREC. We demonstrate
the utility of our model in inferring precision-recall curves. In all experiments our model outperforms the dominant exponential-Gaussian
model. 相似文献
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Aslam Fataar 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1997,43(4):331-348
This paper focuses on the policy issue of expanding schooling in a post-apartheid South Africa. The Project of placing about two million children of school-going age in school is viewed as central to the rebuilding of South Africa. The paper argues that this project should be located within the peculiar history of this country's educational underdevelopment. Challenging the constraining influence of the New Right context should be central in conceptualising the provision of expanded school access. Access policy should be based on a notion of educational development that is linked to the overall socioeconomic development of this society. The view is promoted in this paper that a policy of quantitative expansion of schooling should not ignore the quality of such schooling. 相似文献
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Farzana Shain 《Education 3-13》2016,44(1):8-18
ABSTRACTEducation researchers, policy-makers and practitioners in the UK have debated the question of what, and how much, schools can do to mitigate the effects of parental background on educational outcomes over the last half a century. A range of programmes, strategies and interventions have been implemented, and continue to be implemented in an effort to ‘break the link’ between socio-economic disadvantage and low educational outcomes, but educational inequalities have persisted. This paper draws on theoretical and empirical research to offer a new analysis of compensatory education in England across three main phases since the 1960s. 相似文献
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Singh PP Chandra A Mahdi F Roy A Sharma P 《Indian journal of clinical biochemistry : IJCB》2010,25(3):225-243
The antioxidants are essential molecules in human system but are not miracle molecules. They are neither performance enhancers
nor can prevent or cure diseases when taken in excess. Their supplemental value is debateable. In fact, many high quality
clinical trials on antioxidant supplement have shown no effect or adverse outcomes ranging from morbidity to all cause mortality.
Several Chochrane Meta-analysis and Markov Model techniques, which are presently best available statistical models to derive
conclusive answers for comparing large number of trials, support these claims. Nevertheless none of these statistical techniques
are flawless. Hence, more efforts are needed to develop perfect statistical model to analyze the pooled data and further double
blind, placebo controlled interventional clinical trials, which are gold standard, should be implicitly conducted to get explicit
answers. Superoxide dismutase (SOD), glutathione peroxidase and catalase are termed as primary antioxidants as these scavenge
superoxide anion and hydrogen peroxide. All these three enzymes are inducible enzymes, thereby inherently meaning that body
increases or decreases their activity as per requirement. Hence there is no need to attempt to manipulate their activity nor
have such efforts been clinically useful. SOD administration has been tried in some conditions especially in cancer and myocardial
infarction but has largely failed, probably because SOD is a large molecule and can not cross cell membrane. The dietary antioxidants,
including nutrient antioxidants are chain breaking antioxidants and in tandem with enzyme antioxidants temper the reactive
oxygen species (ROS) and reactive nitrogen species (RNS) within physiological limits. Since body is able to regulate its own
requirements of enzyme antioxidants, the diet must provide adequate quantity of non-enzymic antioxidants to meet the normal
requirements and provide protection in exigent condition. So far, there is no evidence that human tissues ever experience
the torrent of reactive species and that in chronic conditions with mildly enhanced generation of reactive species, the body
can meet them squarely if antioxidants defense system in tissues is biochemically optimized. We are not yet certain about
optimal levels of antioxidants in tissues. Two ways have been used to assess them: first by dietary intake and second by measuring
plasma levels. Lately determination of plasma/serum level of antioxidants is considered better index for diagnostic and prognostic
purposes. The recommended levels for vitamin A, E and C and beta carotene are 2.2–2.8 μmol/l; 27.5–30 μmol/l; 40–50 μmol/l
and 0.4–0.5 μmol/l, respectively. The requirement and recommended blood levels of other dietary antioxidants are not established.
The resolved issues are (1) essential to scavenge excess of radical species (2) participants in redox homeostasis (3) selective
antioxidants activity against radical species (4) there is no universal antioxidant and 5) therapeutic value in case of deficiency.
The overarching issues are (1) therapeutic value as adjuvant therapy in management of diseases (2) supplemental value in developing
population (3) selective interactivity of antioxidant in different tissues and on different substrates (4) quantitative contribution
in redox balance (5) mechanisms of adverse action on excess supplementation (6) advantages and disadvantages of prooxidant
behavior of antioxidants (7) behavior in cohorts with polymorphic differences (8) interaction and intervention in radiotherapy,
diabetes and diabetic complications and cardiovascular diseases (9) preventive behavior in neurological disorders (10) benefits
of non-nutrient dietary antioxidants (11) markers to assess optimized antioxidants status (12) assessment of benefits of supplementation
in alcoholics and heavy smokers. The unresolved and intriguing issues are (1) many compounds such as vitamin A and many others
possessing both antioxidant and non-antioxidant properties contribute to both the activities in vivo or exclusively only to
non-antioxidant activity and (2) since human tissues do not experience the surge of FR, whether there is any need to develop
stronger synthetic antioxidants. Theoretically such antioxidants may do more harm than good. 相似文献
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Shibba Takkar Chhabra Shivani Mehta Sandeep Chhabra Manikant Singla Naved Aslam Bishav Mohan Gurpreet Singh Wander 《Indian journal of clinical biochemistry : IJCB》2018,33(2):235-238
Torsades de pointes with prolonged QTc interval is a form of ventricular tachycardia. Many predisposing factors have been identified and hypocalcemia is among the rare ones. Our case illustrates that though rare, hypocalcemia might manifest as torsades de pointes with prolongation of QTc interval. Early diagnosis and management of dyselectrolytemia can prevent these patients from catastrophic torsades de pointes. 相似文献
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Many queries have multiple interpretations; they are ambiguous or underspecified. This is especially true in the context of Web search. To account for this, much recent research has focused on creating systems that produce diverse ranked lists. In order to validate these systems, several new evaluation measures have been created to quantify diversity. Ideally, diversity evaluation measures would distinguish between systems by the amount of diversity in the ranked lists they produce. Unfortunately, diversity is also a function of the collection over which the system is run and a system’s performance at ad-hoc retrieval. A ranked list built from a collection that does not cover multiple subtopics cannot be diversified; neither can a ranked list that contains no relevant documents. To ensure that we are assessing systems by their diversity, we develop (1) a family of evaluation measures that take into account the diversity of the collection and (2) a meta-evaluation measure that explicitly controls for performance. We demonstrate experimentally that our new measures can achieve substantial improvements in sensitivity to diversity without reducing discriminative power. 相似文献
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