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1.

Background  

Phylogenies capture the evolutionary ancestry linking extant species. Correlations and similarities among a set of species are mediated by and need to be understood in terms of the phylogenic tree. In a similar way it has been argued that biological networks also induce correlations among sets of interacting genes or their protein products.  相似文献   
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Sexual dimorphism in the emergence of the deciduous dentition of French-Canadian children may be explained by differences in recumbent length. Relative to the chronological age scale, boys are longer and their teeth emerge earlier than girls. Recumbent lengths attained at the exact age of emergence, as estimated by fifth-order polynomials fitted to each subject's serial data, are comparable between the sexes. Multi- and univariate analyses of variance show no significant sex differences in the lengths attained at the age of emergence of the deciduous teeth. These findings suggest that clinical standards for emergence of deciduous teeth scaled relative to length rather than chronological age are more accurate and efficient.  相似文献   
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南瓜雌蕊与自花及远缘花粉的相互作用   总被引:2,自引:0,他引:2  
南瓜柱头表面经去垢剂、蛋白酶及Con A处理后花粉不能萌发或花粉管生长受阻,Con A能专一地与柱头表面结合。柱头块加入培养液可促进花粉萌发。不同的远缘花粉授粉后在雌蕊不同部位受阻。在成熟南瓜雌蕊提取液中检测到血凝活性,凝集素可能参与雌蕊对远缘花粉的抑制。  相似文献   
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Weight, stature, arm circumference, and the triceps skinfold were measured in 1,410 school children, 6 through 14 years of age, from two urban colonias in the city of Oaxaca de Juarez (n = 479), and from two rural Ladino (n = 467) and two rural Zapotec (n = 464) communities in the Valley of Oaxaca in southern Mexico. Children from rural Ladino communities and urban colonias are significantly taller, heavier, and more muscular than children in rural Zapotec communities. The differences between rural Ladino and urban colonia children favor the former, particularly for weight and stature. These observations thus suggest (1) that children in the rural, indigenous communities in the Valley of Oaxaca are relatively undernourished compared to children in Ladinoized and urban communities, and (2) that rural-to-urban migration does not necessarily result in improved growth status.  相似文献   
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Weight, stature, arm circumference, and the triceps skinfold were measured in 1,410 school children, 6 through 14 years of age, from two urban colonias in the city of Oaxaca de Juarez (n = 479), and from two rural Ladino (n = 467) and two rural Zapotec (n = 464) communities in the Valley of Oaxaca in southern Mexico. Children from rural Ladino communities and urban colonias are significantly taller, heavier, and more muscular than children in rural Zapotec communities. The differences between rural Ladino and urban colonia children favor the former, particularly for weight and stature. These observations thus suggest (1) that children in the rural, indigenous communities in the Valley of Oaxaca are relatively undernourished compared to children in Ladinoized and urban communities, and (2) that rural-to-urban migration does not necessarily result in improved growth status.  相似文献   
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