Consider the linear system Ax=b where the coefficient matrix A is an M-matrix. In the present work, it is proved that the rate of convergence of the Gauss-Seidel method is faster than the mixed-type splitting and AOR (SOR) iterative methods for solving M-matrix linear systems. Furthermore, we improve the rate of convergence of the mixed-type splitting iterative method by applying a preconditio...

OBJECTIVES To compare individual with community risk factors for adolescent smoking. DESIGN A cross-sectional observational study with multivariate analysis. SETTING National telephone survey. PARTICIPANTS 3646 US adolescents aged 13-18 years in 2007 recruited through a random digit-dial survey. OUTCOME MEASURES Ever tried smoking and, among experimental smokers, smoking intensity (base...

BACKGROUND Girl education is believed to be the best means of reducing girl child marriage (marriage <18 years) globally. However, in South Asia, where the majority of girl child marriages occur, substantial improvements in girl education have not corresponded to equivalent reductions in child marriage. This study examines the levels of education associated with female age at marriage over the ...

BACKGROUND Non-fatal overdose is a major determinant of morbidity among injection drug users (IDU). We sought to evaluate factors associated with non-fatal overdose among IDU in Vancouver. METHODS We examined non-fatal overdose among participants in the Vancouver Injection Drug Users Study. Correlates of non-fatal overdose occurring between 1996 and 2004 were identified using generalized esti...

consider the linear system ax=b where the coefficient matrix a is an m-matrix. in the present work, it is proved that the rate of convergence of the gauss-seidel method is faster than the mixed-type splitting and aor (sor) iterative methods for solving m-matrix linear systems. furthermore, we improve the rate of convergence of the mixed-type splitting iterative method by applying a precondition...

consider the linear system ax=b where the coefficient matrix a is an m-matrix. in the present work, it is proved that the rate of convergence of the gauss-seidel method is faster than the mixed-type splitting and aor (sor) iterative methods for solving m-matrix linear systems. furthermore, we improve the rate of convergence of the mixed-type splitting iterative method by applying a precondition...

BACKGROUND Multi-drug resistance (MDR) has been a cause of concern for tuberculosis (TB) control in both developed and developing countries. This study described the characteristics and risk factors associated with MDR-TB among 287 cases and 291 controls in Henan province, China. METHODS A hospital-based case-control study was conducted between June 2012 and December 2013. The study subjects ...

PURPOSE Postvertebral augmentation vertebral compression fractures are common; repeated vertebral augmentation is usually performed for prompt pain relief. This study aimed to evaluate the incidence and risk factors of repeat vertebral augmentation. METHODS We performed a retrospective, nationwide, population-based longitudinal observation study, using the National Health Insurance Research D...

Background Persons living with HIV often face discrimination in safe sex and reproductive choices, especially in lowresource settings. This study assessed fertility desires and intentions, risk perception and correlates of ever use of at least one safer conception method among HIV-infected women attending a tertiary health facility ...