Distance decay 2.0 - A global synthesis of taxonomic and functional turnover in ecological communities.

Aim: Understanding the variation in community composition and species abundances (i.e., ß-diversity) is at the heart of community ecology. A common approach to examine ß-diversity is to evaluate directional variation in community composition by measuring the decay in the similarity among pairs of communities along spatial or environmental distance. We provide the first global synthesis of taxonomic and functional distance decay along spatial and environmental distance by analysing 148 datasets comprising different types of organisms and environments. Location: Global. Time period: 1990 to present. Major taxa studied: From diatoms to mammals. Method: We measured the strength of the decay using ranked Mantel tests (Mantel r) and the rate of distance decay as the slope of an exponential fit using generalized linear models. We used null models to test whether functional similarity decays faster or slower than expected given the taxonomic decay along the spatial and environmental distance. We also unveiled the factors driving the rate of decay across the datasets, including latitude, spatial extent, realm and organismal features. Results: Taxonomic distance decay was stronger than functional distance decay along both spatial and environmental distance. Functional distance decay was random given the taxonomic distance decay. The rate of taxonomic and functional spatial distance decay was fastest in the datasets from mid-latitudes. Overall, datasets covering larger spatial extents showed a lower rate of decay along spatial distance but a higher rate of decay along environmental distance. Marine ecosystems had the slowest rate of decay along environmental distances. Main conclusions: In general, taxonomic distance decay is a useful tool for biogeographical research because it reflects dispersal-related factors in addition to species responses to climatic and environmental variables. Moreover, functional distance decay might be a cost-effective option for investigating community changes in heterogeneous environments.

The link between childhood sexual abuse and myocardial infarction in a population-based study.

OBJECTIVES: This study examined the relationship between childhood sexual abuse (CSA) and myocardial infarction in men and women, while controlling for social determinants (i.e., socioeconomic status, social support, mental health) and traditional cardiovascular risk factors (i.e., age, race, obesity, smoking, physical inactivity, diabetes mellitus). METHODS: Population-based data were obtained from the 2010 Behavioral Risk Factor Surveillance System. Myocardial infarction was ascertained by self-report of a health-professional diagnosis. CSA was defined as forced sex with someone at least 5 years older before the age of 18. The final sample included 5,095 men and 7,768 women. RESULTS: After adjustment for 15 factors, abused males had nearly 3 times the odds of heart attack compared to non-abused males (OR=2.96; 95% CI=1.12, 7.85). Among women, CSA was not associated with heart attack in the age-race adjusted (OR=1.20; 95% CI=0.39, 3.68) or fully-adjusted (OR=0.88; 95% CI=0.28, 2.75) analyses. CONCLUSIONS: CSA was associated with heart attack in men, even when controlling for traditional risk factors; however, no association was found among women. Future research is needed to replicate the study's unique findings.