Ramsay J O, Bock R D, Gasser T
Department of Psychology, Montreal, Québec, Canada.
Ann Hum Biol. 1995 Sep-Oct;22(5):413-26. doi: 10.1080/03014469500004092.
A new type of smoothing spline designed for nonparametric estimation of growth acceleration curves was applied to longitudinal measures of height from the Fels, Zurich, and Berkeley growth studies. Landmark features of the individual acceleration curves were located and examined for site effects and site by sex interaction. The curves in each group were structurally averaged by transforming the age scale of each child to align the landmarks with overall means. The modal shapes of the structural average curves were found to be highly similar in the three studies, although the relative number of children who conformed to the modal pattern differed among the studies. Significant site by sex interactions were found in the timing of the landmarks associated with the pubertal growth spurt and with the prepubertal 'midspurt'.
一种为生长加速曲线的非参数估计而设计的新型平滑样条被应用于来自费尔斯、苏黎世和伯克利生长研究的身高纵向测量数据。确定了个体加速曲线的标志性特征，并检查了部位效应以及部位与性别的交互作用。通过转换每个儿童的年龄尺度以使标志性特征与总体均值对齐，对每组曲线进行结构平均。尽管符合模式模式的儿童相对数量在各研究中有所不同，但在这三项研究中，结构平均曲线的模态形状高度相似。在与青春期生长突增以及青春期前“中期突增”相关的标志性特征的时间方面，发现了显著的部位与性别交互作用。
