Reginol interpretation of river Indus water quality data using regression model

Water samples were collected from river Indus over 591 km2 from Kashmor to Keti Bandar/Shah Bandar in the province of Sindh, Pakistan, during 2008 and 2009 on seasonal bases. These samples were analyzed for 12 water quality variables including physical and chemical parameters. Then correlation study was carried out and correlation co-efficient “r” was determined using correlation matrix to identify the highly correlated and interrelated parameters. Regression model were developed to test the significant ‘r’ and P-value test was carried out to test the significance of the pair of parameters. F-test was also used to examine the joint-effects of several independent variables without taking into account the separate effects of each variable. The comparison of the observed and predicted values of different parameters using regression equation suggested that the regression model provide useful means of rapid and easier monitoring of water quality of a river in a region.Key words: Regression model, correlation coefficient, river indus, monitoring, physico-chemical parameters

Testosterone Is Associated with Erectile Dysfunction: A Cross-Sectional Study in Chinese Men

Testosterone is essential for the regulation of erectile physiology, but the relationship between low testosterone and erectile dysfunction (ED) has not been firmly established.To examine the association between serum total, free and bio-available testosterone and ED in a population-based sample.A consecutive series of 1776 men aged 20–77 participated in the routine physical examination from September 2009 to December 2009 in Guangxi, China. ED was assessed using the five-item International Index of Erectile Function (IIEF-5) questionnaire. Total testosterone (TT), sex hormone binding globulin (SHBG) and other biochemical profiles were measured. Free testosterone (FT) and bio-available testosterone (BT) were calculated based on Vermeulen’s formula. Data were collected with regard to smoking, alcoholic drinking, physical activity and metabolic syndrome.The prevalence of ED (IIEF-5<22) was 47.6%. Men with ED were significantly older, and more prone to smoke cigarettes (≥20 cigarettes/day) or drink alcohol (≥3 drinks/week), and more likely to have elevated blood pressure (P = 0.036) or hyperglycemia (P<0.001) compared with those without ED. The significant increase in SHBG with age was parallel to its increase with increasing severity of ED (P<0.001). The obscure increase in TT across the ED status was detected without significance (P = 0.418), but TT was positively associated with ED after adjustment for age [odds ratio (OR)  = 1.02, 95% CI (confidence internal): 1.00–1.04]. FT and BT were inversely associated with ED (OR = 0.14, 95%CI: 0.06–0.33; OR = 0.92 (95%CI: 0.89–0.96, respectively) in the univariate analysis, and this inverse association appeared to be independent of smoking status, alcoholic drinking, physical activity, hyper-triglyceridemia and hyperglycemia.FT and BT are inversely related to worsening ED, whereas the positive association between TT and ED is most likely due to the increase in SHBG