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This paper estimates models of the transitional effects of food insecurity experiences on children's non-cognitive performance in school classrooms using a panel of 4710 elementary students enrolled in 1st, 3rd, and 5th grade (1999-2003). In addition to an extensive set of child and household-level characteristics, we use information on U.S. counties to control for potential confounding effects of the local economic and noneconomic environment on children's household transitions between states of food insecurity and food security. The time horizon of our analysis affords insight into factors underlying children's formation of non-cognitive skills and the efficiency of classroom-based educational production in elementary school. Overall, we find significant negative developmental effects for children with food insecurity at home; and that children experiencing an early transition from food insecurity in 1st grade to food security in 3rd grade have even larger impairments that persist through 5th grade.  相似文献   
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We study the problem of web search result diversification in the case where intent based relevance scores are available. A diversified search result will hopefully satisfy the information need of user-L.s who may have different intents. In this context, we first analyze the properties of an intent-based metric, ERR-IA, to measure relevance and diversity altogether. We argue that this is a better metric than some previously proposed intent aware metrics and show that it has a better correlation with abandonment rate. We then propose an algorithm to rerank web search results based on optimizing an objective function corresponding to this metric and evaluate it on shopping related queries.  相似文献   
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This feature briefly examines the development of knowledge translation, knowledge transfer and the knowledge broker role as constituting the next manifestation of the movement that brought us evidence based medicine and its derivatives. It examines the extent to which health information professionals currently meet the specification for a knowledge broker role. In doing so it assesses the strengths and weaknesses of the profession when ranged alongside the five components of the knowledge transfer process that is, problem identification; knowledge development and selection; analysis of context; knowledge transfer interventions; and knowledge utilization. Current deficiencies also lie in a need for political astuteness and awareness and in a lack of knowledge of the most significant models of behavioural change. The feature concludes by examining the potential for knowledge team approaches arguing that gains from a wider perspective that encompasses the entire knowledge process may be even more significant than the pooling of collective knowledge, skills and expertise.  相似文献   
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