New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Contamination on AMS Sample Targets by Modern Carbon is Inevitable

Accelerator mass spectrometry (AMS) measurements of the radiocarbon content in very old samples are often challenging and carry large relative uncertainties due to possible contaminations acquired during the preparation and storage steps. In case of such old samples, the natural surrounding levels of C-14 from gases in the atmosphere, which may well be the source of contamination among others, are 2-3 orders of magnitude higher than the samples themselves. Hence, serious efforts are taken during the preparation steps to have the samples pristine until measurements are performed. As samples often have to be temporarily stored until AMS measurements can be performed, storage conditions also become extremely crucial. Here we describe an assessment of this process of contamination in background AMS samples. Samples, both as pressed graphite (on AMS targets) and graphite powder, were stored in various storage conditions (CO2-spiked air) to investigate the extent of contamination. The experiments clearly show that the pressed targets are more vulnerable to contamination than the unpressed graphite. Experiments conducted with enriched CO2-spiked laboratory air also reveal that the contaminating carbon is not only limited to the target surface but also penetrates into the matrix. A combination of measurements on understanding the chemical nature of the graphitization product, combined with long-available knowledge on "adventitious carbon" from the surface science community, brought us to the conclusion that contamination is to a certain extent inevitable. However, it can be minimized, and should be dealt with by sputter-cleaning the samples individually before the actual measurement

Electronic sputtering of LiF by Krypton (10 MeV/u): size dependent energy distributions of Li+(LiF)n clusters

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