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51.
The field of positive youth development has expanded focus from articulating and measuring desired manifestations of positive well-being to assembling the environmental conditions known to promote these desired outcomes. Evidence of the effectiveness of community-level efforts promoting positive youth development is still emerging, in particular theory-driven examples of community-driven youth development. This study examined the Community Action Framework, one theory-based community youth development model, through the experiences of the Ready by 21 Austin/Travis County coalition (RB21). The coalition connects youth-serving organizations and also regional coalitions, while promoting the positive development of area youth. Participant observation, interviewing, and archival strategies were integrated to capture information related to the complex and dynamic coalition. Results indicated that RB21 represents a practical and meaningful application of the Community Action Framework. Specific examples and recommendations are provided as guidance for other community level youth development efforts.  相似文献   
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Do electronic newspaper databases contain all of the stories that appear in the print edition? And does this depend on the database used? To explore these questions, we collected print copies of newspapers from cities across the USA and Canada. We compared coverage of two topics in these newspapers with the coverage obtained from keyword searches in three electronic newspaper databases. We conclude that the stories obtained through electronic searches are consistent across databases but can vary from the print source. Importantly, national and international coverage is more likely to be missing than local or statewide/provincial coverage.  相似文献   
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A linear population risk model used by the U.S. Food and Drug Administration (FDA) Center for Veterinary Medicine (CVM) estimates the risk of human cases of campylobacteriosis caused by fluoroquinolone-resistant Campylobacter. Among the cases of campylobacteriosis attributed to domestically produced chicken, the fluoroquinolone resistance is assumed to result from the use of fluoroquinolones in poultry in the United States. Properties of the linear population risk model are contrasted with those of a farm-to-fork model commonly used for microbial risk assessments. The utility of the linear population model for the purpose for which it was used by CVM is discussed.  相似文献   
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Travis  Curtis C. 《Risk analysis》1998,18(6):661-662
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55.
Emergy evaluation of food production in urban residential landscapes   总被引:1,自引:0,他引:1  
To transform cities from heterotrophic into sustainable ecosystems many authors have called for increased food production, including home gardening, in urban areas. We conducted an emergy analysis of four model backyard landscape plots—a conventional ornamental landscape, an intensive organic garden, an edible landscape, and a forest garden—to assess the yield and sustainability of these systems. Data were collected during the 2001 growing season and extrapolated to make a five year projection. In the 2001 season, all plots had low Emergy Yield Ratios (EYR) of between 0.0003 and 0.17 and extremely low Emergy Sustainability Indices (SI). In the five year projection, all plots still had low EYRs of between 0.0008 and 0.33 and very low SIs. These low indices are due primarily to the high levels of economic inputs required for the installation and maintenance of these plots in an urban context. Analyses performed on larger systems (households, neighborhoods and cities) containing productive landscapes such as those studied here may produce different results. Installing food-producing landscapes in urban areas without altering the networks by which such landscapes are supplied, however, may not substantially alter the heterotrophic nature of cities.  相似文献   
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This paper reexamines the scaling approaches used in cancer risk assessment and proposes a more precise body weight scaling factor. Two approaches are conventionally used in scaling exposure and dose from experimental animals to man: body weight scaling (used by FDA) and surface area scaling (BW0.67--used by EPA). This paper reanalyzes the Freireich et al. (1966) study of the maximum tolerated dose (MTD) of 14 anticancer agents in mice, rats, dogs, monkeys, and humans, the dataset most commonly cited as justification for surface area extrapolation. This examination was augmented with an analysis of a similar dataset by Schein et al. (1970) of the MTD of 13 additional chemotherapy agents. The reanalysis shows that BW0.75 is a more appropriate scaling factor for the 27 direct-acting compounds in this dataset.  相似文献   
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We examine the roles of major trade languages in international trade and foreign direct investment (FDI) flows. Empirical results confirm that speaking a common language increases trade and FDI flows, yet the effect of major languages is more substantial in FDI than in international trade. In addition, we find evidence of a hierarchy in transaction costs of major languages in both trade and FDI.  相似文献   
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