background: the main purpose of this study was to assess the factorial validity and reliability of the iranian versions of the personality and behavior system scales (49 items) of the ahdq ( the adolescent health and development questionnaire ) and interrelations among them based on jessor's pbt (problem behavior theory) . methods: a multi-staged approach was employed. the cross-cultural adapta...

conclusions orem’s self-care model is significantly effective in reducing the fatigue of multiple sclerosis patients. objectives to determining the effect of orem’s self-care model on fatigue in multiple sclerosis patients. patients and methods this research involved a clinical trial. sixty-three multiple sclerosis patients at the vice-chancellor in treatment affairs of yasuj university of medi...

Work zones are critical parts of the transportation infrastructure renewal process consisting of rehabilitation of roadways, maintenance, and utility work. Given the specific nature of a work zone (complex arrangements of traffic control devices and signs, narrow lanes, duration) a number of crashes occur with varying severities involving different vehicle sizes. In this paper we attempt to inv...

In this article, we show the general relation between standardization methods and marginal structural models. Standardization has been recognized as a method to control confounding and to estimate causal parameters of interest. Because standardization requires stratification by confounders, the sparse-data problem will occur when stratified by many confounders and one then might have an unstabl...

In genome-enabled prediction, parametric, semi-parametric, and non-parametric regression models have been used. This study assessed the predictive ability of linear and non-linear models using dense molecular markers. The linear models were linear on marker effects and included the Bayesian LASSO, Bayesian ridge regression, Bayes A, and Bayes B. The non-linear models (this refers to non-lineari...

Environmental stressors often show effects that are delayed in time, requiring the use of statistical models that are flexible enough to describe the additional time dimension of the exposure-response relationship. Here we develop the family of distributed lag non-linear models (DLNM), a modelling framework that can simultaneously represent non-linear exposure-response dependencies and delayed ...

Probabilistic models over strings have played a key role in developing methods that take into consideration indels as phylogenetically informative events. There is an extensive literature on using automata and transducers on phylogenies to do inference on these probabilistic models, in which an important theoretical question is the complexity of computing the normalization of a class of string-...

Simulation studies present an important statistical tool to investigate the performance, properties and adequacy of statistical models in pre-specified situations. One of the most important statistical models in medical research is the proportional hazards model of Cox. In this paper, techniques to generate survival times for simulation studies regarding Cox proportional hazards models are pres...

the cold climate is a favorable parameter for the development of tension cracks and decrease of rock brittleness. therefore, this paper attempts to investigate the hamekasi porous limestone in order to predict the brittleness indices during freeze-thaw cycles. the freeze–thaw test was executed for one cycle including 16 h of freezing, and 8 h of thawing. the geo mechanical properties and brittl...

We consider the problem of measurements made by several laboratories (or methods) on virtually the same object of interest. In general, the number of measurements made at each laboratory may differ. Moreover, the laboratories may exhibit the between-laboratory variability caused by the systematic error due to each laboratory, as well as different within-laboratory variances caused by different ...