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201.
Abstract: The few available studies on fetal age estimation concern very small samples, and statistical analysis is sometimes inadequate. In this survey, we used germs of deciduous teeth to estimate fetal age. Forty‐nine fetuses and 40 mandibles were scanned, and observations and measurements were made on DentaScan images. After checking their repeatability and reproducibility (analysis of variance), we defined thresholds using Fisher’s linear discriminant analysis to calculate the probability that a fetus was over or below a predefined age threshold. The forensic threshold which is of particular interest in France is 22 weeks amenorrhea. Relationships between fetal age and deciduous germ measurements were then sought by multiple linear regression. The thresholds gave very good results: 91.84% of good probability for the threshold of 22 weeks amenorrhea with no chance of error. The most precise age evaluation obtained nevertheless gave a range of ±4.6 weeks amenorrhea, so greater accuracy is still needed.  相似文献   
202.
Drawing from an ecological assets framework as well as research and theory on positive youth development, this study examined the relationship of early adolescents’ satisfaction with life to trait optimism and assets representing the social contexts in which early adolescents spend most of their time. Self-reports of satisfaction with life, optimism, and ecological assets in the school (school connectedness), neighborhood (perceived neighborhood support), family (perceived parental support), and peer group (positive peer relationships) were assessed in a sample of 1,402 4th to 7th graders (47% female) from 25 public elementary schools. Multilevel modeling (MLM) was conducted to analyze the variability in life satisfaction both at the individual and the school level. As hypothesized, adding optimism and the dimensions representing the ecology of early adolescence to the model significantly reduced the variability in life satisfaction at both levels of analysis. Both personal (optimism) and all of the ecological assets significantly and positively predicted early adolescents’ life satisfaction. The results suggest the theoretical and practical utility of an assets approach for understanding life satisfaction in early adolescence.  相似文献   
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