Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Genetic variation of traits measured in several environments. II. Inference on between-environment homogeneity of intra-class correlations | Genet Sei Evol 1995 27 125-134 Elsevier INRA 125 Original article Genetic variation of traits measured in several environments. II. Inference on between-environment homogeneity of intra-class correlations c Robert JL Foulley V Ducrocq Institut national de la recherche agronomique station de génétique quantitative et appliquée centre de recherche de Jouy-en-Josas 78352 Jouy-en-Josas cedex France Received 28 April 1994 accepted 26 September 1994 Summary - This paper describes a further contribution to the problem of testing homogeneity of intra-class correlations among environments in the case of univariate linear models without making any assumption about the genetic correlation between environments. An iterative generalized expectation-maximization EM algorithm as described in Foulley and Quaas 1994 is presented for computing restricted maximum likelihood REML estimates of the residual and between-family components of variance and covariance. Three different parameterizations cartesian polar and spherical coordinates are proposed to compute EM-REML estimators under the reduced constant intra-class correlation between environments model. This procedure is illustrated with the analysis of simulated data. heteroskedasticity parameterization intra-class correlation expectationmaximization restricted maximum likelihood Resume Variation génétique de caractères mesurés dans plusieurs milieux. II. Inference relative à des correlations intra-classe constantes entre milieux. Get article décrit une approche permettant d estimer les composantes de variance-covariance entre milieux dans le cas de correlation intra-classe homogènes entre milieux sans faire d hypothese sur les correlations génétiques entre milieux pris 2 à 2. Un algorithme iteratif d esperance-maximisation EM comparable à celui décrit par Foulley et Quaas 1994 est propose pour calculer les estimations du maximum de vraisemblance restreinte REML des com-posantes résiduelles etfamiliales de variance covariance. .
