We examine the effect of model misspecification for two classes of semi-parametric survival models frequently used for the analysis of right-censored survival data, additive and multiplicative models for the conditional hazard rate. The additive class will be represented by Aalen’s linear model [1], while the multiplicative class will be represented by the Cox proportional hazards (PH) model [2...

In this study phenotypic and genetic factors affecting the reproductive efficiency of Lori-Bakhtiari ewes were determined using 8202 reproductive records of 2478 ewes collected at Shooli research station in the southwestern part of Iran (Shahrekord) during 1989 to 2012. Reproductive efficiency over all consecutive lambing opportunities were calculated by adding the total reproductive efficiency...

introduction: genetic resources in any country are valuable materials which needed to be conserved for a sustainable agriculture. an animal phenotype is generally affected by genetic and environmental factors. to increase mean performance in a population under consideration not only environmental conditions, but also genetic potential of the animals should be improved. although, environmental i...

in this research, 6517 records, collected by khojir sheep breeding station (tehran, iran), during 1991 to 2011 were used to estimate genetic parameters of lamb survival in zandi sheep. genetic parameters were estimated using 16 different models of animal model, sire and threshold models using reml procedures. the aic criterion was used to evaluate the models. the effects in the most suitable an...

in this study, the effect of maternal additive genetic and environment on body weight at 6 weeks (bwt6w), breast width (hbrs), carcass weight (carcwt), breast weight (brswt), blood hematocrit value (hem), residual feed intake (rfi), daily feed intake (dfi) and average daily gain (adg) were investigated in a commercial broiler dam line. with and without maternal effects, six different animal mod...

This paper considers statistical inference for additive partial linear models when the linear covariate is measured with error. To improve the accuracy of the normal approximation based confidence intervals, we develop an empirical likelihood based statistic, which is shown to be asymptotically chi-square distributed. We emphasize the finite-sample performance of the proposed method by conducti...

A 4exible method for modelling capture–recapture data with continuous covariates that describe heterogeneous catchability is developed. The well established generalized additive modelling framework is used. An estimator of population size is developed using this method. The performance of the method is demonstrated using neural tube defect capture–recapture data from the Netherlands, with the b...

BACKGROUND Multi-state models, as an extension of traditional models in survival analysis, have proved to be a flexible framework for analysing the transitions between various states of sickness absence and work over time. In this paper we study a cohort of work rehabilitation participants and analyse their subsequent sickness absence using Norwegian registry data on sickness benefits. Our aim ...