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This article reports the first results of the three-year longitudinal study of the social maps of children beginning the transition to adolescence. This exploratory study is guided by Bronfenbrenner's conception of the ecology of human development, stressing the importance of a phenomenological orientation to development in the context of ecological transitions. The study focuses on characteristics of children's social networks (the web of relationships in which the individual is involved) as a function of neighborhood type, socioeconomic status, and level of physical maturation. The social heterogeneity of the social network (e.g., the relative salience of peers versus adults) is a primary concern. The child's and parent's perceptions of the network, of the people available to help the child, and the child's friends are compared within the context of ecological, socioeconomic, and maturational factors. The results (for 111 sixth-grade children from three contrasting neighborhood schools) shed some light on age segregation and the overall heterogeneity of the social environments of children facing the transition to adolescence. They provide a context and a baseline for the longitudinal study.A version of this paper was presented at the 85th annual convention of the American Psychological Association, San Francisco, August 25–30, 1977.Received his Ph.D. in human development and family studies from Cornell University in 1973. Principal interests are the ecology of social development and child maltreatment.  相似文献   
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The accuracy and precision of chronological age estimation based on the stages of third molar tooth development was studied in a sample of 679 radiographs from individuals of Hispanic origin. The age range was 14.0 to 25.0 years. Eight raters from the University of Texas Health Science Center at Houston Dental Branch evaluated the radiographs according to Demirjian's schematic definitions of crown and root formation. The objective of this study was to evaluate the chronology of third molar development in Hispanics following the protocol of a previous study. Within the Hispanic population, the rate of male third molar development is greater than that of female third molar development for ten stages of crown-root formation. Also within this Hispanic population sample, the rate of maxillary third molar development is ahead of mandibular third molar development. The mean absolute difference between chronological age and estimated age was +/-3.0 years in females and +/- 2.6 years in males.  相似文献   
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New formulae for estimating stature in the Balkans   总被引:2,自引:0,他引:2  
Recent studies of secular change and allometry have observed differential limb proportions between the sexes, among and within populations. These studies suggest that stature prediction formulae developed from American Whites may be inappropriate for European populations. The purpose of this investigation is to present more appropriate stature prediction equations for use in the Balkans to aid present-day identifications of the victims of genocide. The reference sample totals 545 white males obtained from World War II data. The Eastern European sample totals 177 males and includes both Bosnian and Croatian victims of the recent war. Mean stature for Eastern Europeans was obtained from the literature. Results show that formulae based on Trotter and Gleser systematically underestimate stature in the Balkans. Because Eastern Europeans are taller than American Whites it is appropriate to use this as an "informative prior" that can be applied to future cases. This informative prior can be used in predictive formulae, since it is probably similar to the sample from which the Balkan forensic cases were drawn. Based on Bayes' Theorem new predictive stature formulae are presented for Eastern Europeans.  相似文献   
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The PowerPlex 16 System from Promega Corporation allows single tube multiplex amplification of sixteen short tandem repeat (STR) loci including all 13 core combined DNA index system STRs. This report presents an updated validation of the PowerPlex 16 System on Applied Biosystem's 96 capillary 3730xl DNA Analyzer. The validation protocol developed in our laboratory allows for the analysis of 1536 loci (96 x 16) in c. 50 min. We have further optimized the assay by decreasing the reaction volume to one-quarter that recommended by the manufacturer thereby substantially reducing the total cost per sample without compromising reproducibility or specificity. This reduction in reaction volume has the ancillary benefit of dramatically increasing the sensitivity of the assay allowing for accurate analysis of lower quantities of DNA. Due to its substantially increased throughput capability, this extended validation of the PowerPlex 16 System should be useful in reducing the backlog of unanalyzed DNA samples currently facing public DNA forensic laboratories.  相似文献   
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In recent years climate change has become integrated into pre-existing, but fragmented structures of global security governance. In this article I argue that while institutional fragmentation of global climate security governance is not automatically problematic, the phenomenon of ideational fragmentation that often goes with it is highly disadvantageous to achieving climate security for people. This is because the preferences of a diverse group of security organisations/actors (in this article the Organisation for Security and Co-operation in Europe, the North Atlantic Treaty Organisation, the European Union and the United States/Pentagon) are often vastly removed from the global agenda set by the United Nations and its expressed preference for understanding climate security in terms of human security. I suggest that the first step towards overcoming ideational fragmentation would have to be the advancement of a universal definition of climate security by an authoritative source, however, given that security is for many actors a matter of perception the chances of overcoming ideational fragmentation are slim.  相似文献   
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