Random regression analyses to model the longitudinal measurements of yolk proportions in the laying chicken.

Cubic spline function was used in a genetic evaluation to model the change of yolk proportion over the lay life. A total of 19,862 yolk proportion records of 2,324 hens was used. The evaluated submodels consisted of 3 to 6 knot models. The same knots were fitted for genetic and permanent environmental splines. The residual effects were specified to be independently and normally distributed, but with heterogeneous variance for each test week. (Co)variance components were estimated by the average information restricted maximum likelihood (AIREML) method. The best fitting random regression model (RRM) was a submodel with 4 knots at 32, 36, 52, and 72 wk of age for genetic and permanent environmental effects. The estimate of genetic variance was larger than that of permanent environmental variance at the same time point. The heritability of yolk proportion ranged from 0.32 to 0.55, and the repeatability ranged between 0.45 and 0.73. The genetic correlations between test wk were from moderate to unity. To the best of our knowledge, this was the first report on the use of a RRM to evaluate yolk proportion. The results of this study showed that random regression models with the spline function could be used for improvement of yolk proportion.

Comparative study on radiation pneumonitis occurred in lung cancer with mediastinal tumors and esophageal after radiotherapy / 肿瘤研究与临床

Objective A comparative study of clinical factors and dose-volume histogram (DVH)parameters on the impact of radiation pneumonitis occurred in the three-dimensional conformal radiotherapy of lung cancer (lung target)and mediastinal tumors and esophageal (mediastinal target).Methods Review 83cases lung cancer,mediastinal tumors and esophageal patients,and analyzed with chi-square tests on the correlation of the clinical factors (gender,age,tumor location,stage,chemotherapy) with radiation pneumonitis;have relevance analysis between the DVH parameters of two targets and radiation pneumonitis; lung target and mediastinal target volume DVH parameters compared to the t-test.Results ≥2 radiation pneumonitis was 36.5 ％.≥2 radiation pneumonitis occurred in various clinical factors had no significant effect.DVH parameters of the two targets,V5,V10,V20,V30,whole lung dose (MLD) were significantly related to RP.Two targets of RP patients V5 [(50.9±17.8) ％,(69.9±20.4) ％],V10 [(38.6±15.2) ％,(53.5±18.8) ％] were statistically significant by t-test (t =2.434,P ＜ 0.05),while V20 (t =0.388,P ＞ 0.05),V30 (t =0.005,P ＞ 0.05) and MLD (t =0.138,P ＞0.05) were no significant difference (P ＞ 0.05),so the same results with the two targets of patients without RP obtained.Conclusion In the lung target and mediastinal target of radiotherapy radiation pneumonitis is related with DVH parameters,especially V20,V30 and MLD impact on the occurrence of RP.