Association between HSV1 Seropositivity and Obesity: Data from the National Health and Nutritional Examination Survey, 2007–2008

BACKGROUND: Herpes simplex virus (HSV) is among the most common sexually transmitted pathogens in the United States and worldwide. HSV has a high incidence of undetected cases. In addition, there is no treatment, and there is a lack of knowledge why disparities among populations exist. Research studies suggest that fat tissue may participate in body's immune responses, and the impact of obesity on susceptibility to HSV1 infection is not clear. The purpose of this study was to examine whether obesity is a risk factor for HSV1 infection using a large sample from the general population. METHODS/PRINCIPAL FINDINGS: This cross-sectional study used data from the National Health and Examination and Nutritional Examination Survey (NHANES) from 2007-2008. Variables, gender, age, race/ethnicity, marital status, education, poverty level, and diabetes represented potential confounders and were included in analyses. The two-tailed Pearson's chi square, student's t test, and a multiple logistic regression analysis were applied to evaluate associations using a significance value of p≤0.05. Adjusted odds ratios with 95% confidence interval represented the degree of these associations. The prevalence of HSV1 infection in US population between 20 and 49 years old was 60.3% (n = 1,536). In this study, having a BMI classified as the obese group (BMI 30-39.9) was significantly associated with HSV1 infection before [unadjusted OR = 1.74 (95% CI 1.20-2.51), p = 0.006] and after controlling for socio-demographic factors [adjusted OR = 1.50 (95%CI 1.06-2.13)], p = 0.026]. This association was stronger than three already established risk factors of age, female gender, and poverty level. CONCLUSIONS/SIGNIFICANCE: This study provides evidence that obesity may play a role in the susceptibility to HSV1 infection. Findings from this study suggest that obesity should be considered when designing preventive measures for HSV1 infection. These results may also explain why some people acquire HSV1 infections and some do not. Further, these findings may justify an increased emphasis on the control and prevention of HSV1 transmission and other pathogens in overweight and obese populations

Measurements of the friction coefficient: discussion on the results in the framework of the time series analysis

Tribology studies the interaction between surfaces in relative motion with a particular focus on the principles of friction, wear and lubrication. The measurement of the friction coefficient (COF) is extremely sensitive to experimental friction force fluctuations thus making COF direct measurement not a trivial task. In this manuscript, a novel approach toward the understanding of the friction coefficient behavior during reciprocating tests is proposed. The proposed procedure represents a first approach for a deep investigation about measured COF distribution during tribological tests. It is based on the analysis of COF data measured during the tests in the framework of time series analysis and it was applied to several real tests in dry-friction showed as example of application. Output parameters (i.e., friction, traction force) were investigated to detect trends, connected to running-in period of the tribo-couple, seasonal, connected to the periodicity induced from reciprocating motion, and residual components. After “smoothing” the COF data set by removing the trend and seasonal components, the residual component was analyzed to check the stationary of the COF data set which represents the most characteristic interval in friction measurements