A Markov chain model has been proposed as a mechanism that generates human sleep stages. A method for estimating the parameters of the model, i.e., the transition probabilities (rates) between sleep stages, has been introduced and applied to 95 hypnograms taken from 23 subjects. The rates characterize interindividual differences and nightly variations of the sleep mechanism, related to sleep-on...

Background & Aims: There are limited information about prevalence of smoking, drug abuse and its associated factors amongst Iranian students. The present study aimed to determine prevalence of smoking and drug abuse amongst male high school students in Ilam and the role of associated psychological and social factors. Method: Overall, 1000 male high school students were recruited using a multi-s...

Due to the rapid development of information technology, an increasing number smokers choose online smoking cessation communities interact with other individuals help themselves quit smoking. Though it is well known that social support plays a key role in process cessation, features one can get from remain unclear. We collected user interaction data largest Chinese community, forum Baidu Tieba. ...

OBJECTIVE Evaluate the implementation of a smoking prevention program via a questionnaire. Both knowledge and attitudes toward smoking behavior and smoking cessation were also investigated MATERIAL AND METHOD An experimental study was conducted between October 2011 and July 2012. Two hundred twenty six school students from Mathayom 1 to 6 participated into the present study. They were divided...

PURPOSE This study examined the moderating and mediating effects of self-efficacy on the relationships between predictor variables (decisional balance and processes of change) and the outcome variable (stages of change) using the Transtheoretical Model. DESIGN Cross-sectional data were collected from 147 current and former smokers at three vocational technical high schools in Korean metropoli...

Growth and pubertal development are important health markers. We used the data of a longitudinal growth study on a contemporary sample of US youth to examine the relationship between peak height velocity (PHV) and Tanner staging. We observed a substantial variability in the timing of PHV across Tanner stages, which is an important consideration for clinicians when assessing growth.