Intergenerational correlations in size at birth and the contribution of environmental factors: The Uppsala Birth Cohort Multigenerational Study, Sweden, 1915-2002.

Sizes at birth of parents and their children are known to be correlated, reflecting in part the influence of fetal and maternal genes. Sociodemographic factors, regarded as aspects of the shared environment across generations, would also be expected to contribute, but evidence is limited. In the present study, the authors aimed to quantify the role of the shared environment in explaining intergenerational correlations in birth weight and length by using data across 3 consecutive generations from the Uppsala Birth Cohort Multigenerational Study in Uppsala, Sweden. That study included birth and sociodemographic data on 7,657 singletons born in Uppsala in 1915-1929 (generation 1) and their grandchildren (generation 3). Standard regression and biometric models were used to study the correlations in size at birth of generation 1-generation 3 pairs. The data showed stronger correlations in maternal pairs than in paternal pairs for birth weight (0.125 vs. 0.096, P = 0.02) but not for birth length (0.097 vs. 0.093, P = 0.77). These correlations were not reduced by adjustment for sociodemographic factors in regression models. In contrast, significant shared-environment contributions to the intergenerational correlations were identified in biometric models, averaging 14% for both birth measures. These models assumed a common latent factor for the sociodemographic variables. The present results show that the shared environment moderately but significantly contributes to intergenerational correlations

A new method for numerical solution of checkerboard fields

We consider a generalized version of the standard checkerboard and discuss the difficulties of finding the corresponding field by standard numerical treatment. A new numerical method is presented which converges independently of the local conductivities

Contrasting Effects of Maternal and Paternal Age on Offspring Intelligence: The clock ticks for men too

Mary Cannon discusses the implications of a new cohort study showing an association between increasing paternal age and poorer cognitive abilities in the offspring

Wiener integrals, Malliavin calculus and covariance measure structure

We introduce the notion of {\em covariance measure structure} for square integrable stochastic processes. We define Wiener integral, we develop a suitable formalism for stochastic calculus of variations and we make Gaussian assumptions only when necessary. Our main examples are finite quadratric variation processes with stationary increments and the bifractional Brownian motion.Comment: 50 page

Smoking Patterns in Ghanaian Civil Servants: Changes Over Three Decades

The number of smokers in developing countries is expected to increase as markets in high income countries begin to decline and multinational tobacco companies shift their marketing efforts to lower income countries. We determined the prevalence and distribution of smoking in a cross-sectional study of 1,015 urban civil servants in Accra, Ghana (82.7% participation rate) in 2006. The results were compared to the findings from a previous study in 1976 of civil servants in Accra to estimate the changes in smoking patterns over a 30 year period. In our 2006 study, the smoking prevalence rate was 6.1% (95% CI: 4.8–8.9) and 0.3% (95% CI: 0.006–1.4) in men and women respectively. These figures were dramatically lower than the rates of 32% and 5.9% reported for men and women respectively in the previous study. Knowledge of the health risks associated with smoking may have contributed to the lower rates

The association between anthropometric measures of adiposity and the progression of carotid atherosclerosis.

BACKGROUND: Few reports are available on the contribution of general and abdominal obesity to the progression of carotid atherosclerosis in late adulthood. This study investigated the impact of four simple anthropometric measures of general and abdominal obesity on the progression of carotid atherosclerosis and the extent to which the association between adiposity and the progression of plaque burden is mediated by cardiometabolic markers. METHODS: Four thousand three hundred forty-five adults (median age 60) from the population-based Tromsø Study were followed over 7 years from the first carotid ultrasound screening to the next. The progression of carotid atherosclerosis was measured in three ways: incidence of plaques in previously plaque-free participants; change in the number of plaques; and total plaque area (TPA). We used generalised linear models to investigate the association between each adiposity measure - body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) - and each outcome. Models were adjusted for potential confounders (age, sex, smoking, education, physical activity). The pathways through which any associations observed might operate were investigated by further adjusting for cardiometabolic mediators (systolic blood pressure, cholesterol, and HbA1c). RESULTS: There was little evidence that adiposity was related to the formation of new plaques during follow-up. However, abdominal adiposity was associated with TPA progression. WHtR showed the largest effect size (mean change in TPA per one standard deviation (SD) increase in WHtR of 0.665 mm2, 95% confidence interval 0.198, 1.133) while BMI showed the smallest. Effect sizes were substantially reduced after the adjustment for potential mediators. CONCLUSIONS: Abdominal obesity indirectly measured with WC seems more strongly associated with the progression of TPA than general obesity. These associations appear to be largely mediated by known cardiometabolic markers