Study of the Effect of Service Period on Milk Productivity

This article provides information about the service life of cows after calving. Also, the amount of unrefined fat in the diet of pregnant cows should not exceed 40-50 g, which corresponds to 1 t of live weight. Given that the excess carbohydrates consumed in the animal's body are also converted into fat, it is necessary to once again avoid the excess of easily digestible carbohydrates in the die

Cook's distance for ridge estimator in semiparametric regression

Abstract The detection of influential observations has attracted a great deal of attention in last few decades. Most of the ideas of determining influential observations are based on single-case diagnostics with ith case deleted. The Cook's distance are most commonly used among the other single-case diagnostics and successfully applied to various statistical models. In this article, we propose Cook's distance for the ridge regression estimator of the parametric component in the semiparametric regression model to detect influential observations. We investigate the performance of proposed diagnostic to detect influential observations by using real data and simulation data

Detection of influential observations in semiparametric regression model

En este artículo, se consideran modelos de regresión semiparamétrica yse examinan observaciones influenciales que pueden tener efectos sobre losestimadores para este modelo. Una de las formas de medir la influenciade una observación individual es borrando la observación en el conjunto de datos. La medida más común bajo esta idea es la distancia de Cook. Recientemente,Daniel Peña introdujo una nueva medida basada en estas ideas.Las distancias de Cook para el vector de parámetros, la función de suavizamientoy la variable respuesta en modelos de regresión semiparamétrica hansido expresadas por otros autores como funciones de los residuales y los puntosde apalancamiento. Se deriva en este artículo, una medida del tipo de lade Peña como función de los residuales y puntos de apalancamiento para elmismo modelo. Se compara el desempeño de estas medidas para la detecciónde observaciones influenciales usando datos reales y bajo simulación. Los resultadosmuestran que la medida de Peña es mejor que la distancia de Cookpara detectar outliers y puntos de apalancamiento en conjuntos de datosgrandes en los modelos de regresión semiparamétrica tales como el modelode regresión lineal

Thermoluminescent properties of Sr2P2O7 doped with copper and some rare earth elements

In this study. Sr2P2O7 was doped with some rare earth oxides (Pr6O11, Nd2O3, Dy2O3, Ho2O3, Er2O3, and Tm2O3) at 0.5%, 1%, 2%, 3%, 4%, 5%, 10%, and 15% (by weight) and co-doped with CuO by heating at 900 C for 10 h. Structural analysis of the products was carried out by powder X-ray diffraction (XRD). XRD patterns of the samples showed that doping did not alter the orthorhombic structure of the Sr2P2O7. Thermoluminescence (TL) glow curve measurements were obtained and these showed that Pr and Cu-doped Sr2P2O7 exhibit very significant thermoluminescence glow peaks, suggesting these could be promising dosimetric materials. Bearing this in mind, some TL dosimetric properties of Sr2P2O7:Cu,Pr compounds are presented in this paper, confirming they are promising for this application

Enuresis prevalence and accompanying factors in schoolchildren: A questionnaire study from Southeast Anatolia

Introduction: The aims of this study were to establish the prevalence of enuresis, to determine accompanying factors, and to identify common methods in the management of enuresis in Turkish children aged between 6 and 11 years living in eastern Anatolia. Methods: The parents of 3,527 schoolchildren aged between 6 and 11 years completed a self-administered questionnaire. The questionnaire asked about sociodemographic data, enuresis data, physical or psychological disorders, and family stressors. Descriptive statistics and chi(2) test were used for data analysis. Results: The response rate was 88%. The overall prevalence of reported enuresis was 12.96%, and the prevalence of marked enuresis ( at least weekly) was 9.8%. Enuresis was notably more common in boys ( male: female ratio 1.6), and the prevalence rates decreased by age without gender bias. Of all enuretic children, 21% had also daytime bed-wetting. The rate of a positive family history was 42% for siblings only and 66% for the other family members. Significantly more of the dry children woke up spontaneously at night to void as compared with the enuretic children ( p < 0.001). The parental concern level was not high, and only 15% of the children visited a physician for the management of enuresis. Low socioeconomic status, unfavorable perinatal or postnatal history, and unsatisfactory familial characteristics were significantly more frequent in the enuretic group (p < 0.05). The enuretic children had also higher rates of poor school performance and poor social adaptation as compared with nonenuretic children (p < 0.001). Conclusions: These results suggest that the prevalence of enuresis in eastern Anatolia is similar to that reported from western Anatolia and from most other countries. Turkish families did not report a high-level concern about enuresis, and the problem was managed primarily within the family. Copyright (C) 2004 S. Karger AG, Basel