Coefficient of Partial Correlation and Its Calculation

This thesis offers the general concept of coefficient of partial correlation.Starting with regres-sion analysis,the paper,by using samples,infers the general formula of expressing coefficient of partial correlation by way of simple correlation coefficient.

Statistical Analysis of Leaf Water Use Efficiency and Physiology Traits of Winter Wheat Under Drought Condition

Five statistical methods including simple correlation, multiple linear regression, stepwise regression, principal components, and path analysis were used to explore the relationship between leaf water use efficiency （WUE） and physiological traits （photosynthesis rate, stomatal conductance, transpiration rate, intercellular CO2 concentration, etc.） of 29 wheat cultivars. The results showed that photosynthesis rate, stomatal conductance, and transpiration rate were the most important leaf WUE parameters under drought condition. Based on the results of statistical analyses, principal component analysis could be the most suitable method to ascertain the relationship between leaf WUE and relative physiological traits. It is reasonable to assume that high leaf WUE wheat could be obtained by selecting breeding materials with high photosynthesis rate, low transpiration rate, and stomatal conductance under dry area.

A Cross-Sectional Study According to Risk Factors Associated with Erectile Dysfunction in Men

Background: Erectile dysfunction (ED) is a common condition in general population. It has a negative impact on the couple’s quality of life. In 1995, it was estimated that it affected 152 million people worldwide, and that it would affect more than 322 million people in 2025 with a large increase in developing countries. Several studies have suggested a causal link between ED and cardiovascular disease. In the Democratic Republic of Congo, no studies exist on this subject. Nonetheless, we are seeing increased promotion on the management of sexual disorders in our media, which could testify to the extent of this problem. Objective: To assess the extent of cardiovascular risk factors for ED in Kinshasa. Material and Methods: This is a cross-sectional study for analytical purposes. It collected several categories of individuals from May 1 to October 31, 2018. The severity of ED was assessed by the IIEF-5 score and the associated risk factors sought via logistic regression. Results: The mean age of the respondents was 59.9 ± 19.2 years, more than half of the respondents were over the age of 60 years old (60%). The ED proportion was 78.8%, and 75% of respondents had at least moderate ED. This anomaly was significantly elevated among respondents aged over 60 years (94.8%), diabetics (87.5%), hypertensive patients (92.3%) and stroke victims (86%). The independently associated risk factors were: age > 60 years [ORa: 9.87;95% CI: 6.42 - 10.48, p < 0.001], diabetes mellitus [ORa: 2.99;95% CI: 1.80 - 4.95, p = 0.013] and the stroke [ORa: 2.1;95% CI: 1.36 - 3.39;p = 0.012%]. The age threshold predicting ED was 67 years. Conclusion: ED is a frequent disorder in our environment and likely to affect the quality of life of men who suffer from it. There is an ED and cardiovascular risk factors correlation. A proactive attitude of the caregiver in current practice would allow early detection of ED with a view to early and optimal management.