tailieunhanh - báo cáo khoa học: "Selection on selected records"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Selection on selected records | Génét. Sél. Evoỉ. 1983 15 1 91-98 Selection on selected records B. GOFFINET . Laboratoừe de Biométrie Centre de Recherches de Toulouse c hemin de Borde-Rouge F 31320 Castanet-Tolosan Summary The problem of selecting individuals according to their additive genetic values and of estimating those values is considered. It is assumed that the selection is based on a vector of observations made on a group of individuals which were themselves selected according to 1 certain vector of observations. An optimal selection rule applicable irrespective of the distribution of the random variable nvolved in the setting is derived. In particular it is shown that the restrictions regarding the ise of the BLUP Best Linear Unbiased Predictor pointed out by Henderson can be relaxed. Key-words Selection mixed models BLUP. Resume Selection sur données issues de selection On considère le problème de la selection d individus pour leurs valeurs génétiques additives et de I estimation de ces valeurs. La selection est basée sur un vecteur d observations faites sur un ensemble d individus eux-mêmes issus d une selection sur un certain vecteur d observations. On obtient une regie optimale de selection applicable quelle que soit la distribution des variables aléatoires de 1 expérience. En particulier on montre que les contraintes d utilisation du BLUP meilleur prédicteur linéaire sans biais proposées par Henderson peuvent être atténuées. Mots-clés Selection modèle mixte BLUP. I. Introduction Animal and plant breeders are often faced with the problem of choosing items . sires or varieties among a set of available candidates. Generally selection is based on a vector of observations made on these or other items which were themselves selected according to another vector of observations. Therefore it is important to develop a selection rule that is optimal in some sense. Henderson 1973 1975 in a multi- 92 B. GOFFINET variate normal setting showed that if certain conditions related to fixed