STRONG REPRESENTATION OF THE QUANTILE FUNCTION FOR LEFT TRUNCATED AND DEPENDENT DATA

International audienceLet (X i) i≥1 be a sequence of strong-mixing random variables with common unknown absolutely continuous distribution function F subject to random left truncation. Let F −1 (p) denote the pth (p ∈]0, 1[) quantile function of the marginal distribution function of the X i 's which is estimated by the sample quantile F −1 n (p). In this paper, we derive the strong consistency and a strong representation for F −1 n (p), the quantile function of the Lynden-Bell estimator of F for strong-mixing processes

Does biological maturity actually confound gender-related differences in physical activity in preadolescence?

Aim To examine: (i) if maturity-related gender differences in moderate-to-vigorous physical activity (MVPA) depend on how maturity status is defined and measured; and (ii) the influence of maturity level on compliance with PA recommendations. Methods The study involved 253 children (139 boys) aged 9.9 ± 0.9 years, with mean stature and weight of 1.39 ± 0.08 m and 35.8 ± 8.8 kg respectively. Their PA was evaluated using an Actigraph accelerometer (Model 7164). Maturity was assessed using the estimated age at peak height velocity (APHV) and a standardized APHV by gender (i.e. centred APHV). Results Boys engaged in significantly more MVPA than girls (P < 0.0001). There was a significant correlation between the centred APHV and MVPA in boys (r = 0.20; P = 0.016), but not in girls (r = 0.13; P = 0.155). An ancova controlling for the estimated APHV showed no significant interactions between gender and APHV, and the main effect of gender on MVPA was negated. Conversely, there was a significant main effect of APHV on MVPA (F 1,249 = 6.12; P = 0.014; η p 2 = 0.024). Only 9.1% of children met the PA recommendations, including 14.4% of boys and 2.6% of girls (P < 0.01). This observation also applies in both pre-APHV (12.7% of boys vs. 2.4% of girls, P < 0.001) and post-APHV children (23.8% of boys vs. 3.4% of girls, P < 0.0001). No differences in PA guidelines were observed between pre-APHV and post-APHV children. Conclusions Among prepubescent children, the influence of biological maturity on gender differences in PA may be a function of how maturity status is determined. The most physically active prepubescent children were those who were on time according to APHV

Tests dans le cas d'un melange de lois dans les modeles parametriques et non parametriques

* INRA, Laboratoire de Biometrie, Centre de Jouy en Josas Diffusion du document : INRA, Laboratoire de Biometrie, Centre de Jouy en Josas Diplôme : Dr. d'Universit

Tests for genetic linkage and homogeneity

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Estimation and tests in finite mixture models for censored survival data

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Likelihood ratio tests in contamination models

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