DNA methylation age of blood predicts all-cause mortality in later life

Background: DNA methylation levels change with age. Recent studies have identified biomarkers of chronological age based on DNA methylation levels. It is not yet known whether DNA methylation age captures aspects of biological age. Results: Here we test whether differences between people's chronological ages and estimated ages, DNA methylation age, predict all-cause mortality in later life. The difference between DNA methylation age and chronological age ({increment}age) was calculated in four longitudinal cohorts of older people. Meta-analysis of proportional hazards models from the four cohorts was used to determine the association between {increment}age and mortality. A 5-year higher {increment}age is associated with a 21% higher mortality risk, adjusting for age and sex. After further adjustments for childhood IQ, education, social class, hypertension, diabetes, cardiovascular disease, and APOE e4 status, there is a 16% increased mortality risk for those with a 5-year higher {increment}age. A pedigree-based heritability analysis of {increment}age was conducted in a separate cohort. The heritability of {increment}age was 0.43. Conclusions: DNA methylation-derived measures of accelerated aging are heritable traits that predict mortality independently of health status, lifestyle factors, and known genetic factors

Volgo-Uralia : the first U-Pb, Lu-Hf and Sm-Nd isotopic evidence of preserved Paleoarchean crust

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Danopolonian migmatization of Mesoproterozoic sedimentary rocks in southernmost Sweden: a SIMS zircon study

To assess the age and origin of the metasedimentary migmatites in southernmost Sweden and their relationships with the Mesoproterozoic granitoid magmatism in the area, we have dated migmatite zircon using the secondary ion mass spectrometry U-Pb method. The studied metasedimentary migmatites, here called the Noteboda migmatites, occur along the southwestern boundary of the 1442 Ma Taghusa granitoid intrusion in southeastern Skane. They contain the mineral assemblage garnet + biotite +/- muscovite + cordierite + sillimanite + quartz + plagioclase + K-feldspar and were formed during a retrograde evolution from c. 750-720 degrees C and 6 kbar (peak conditions) to c. 675 degrees C and 4 kbar. Zircon is characterized by detrital cores surrounded by U-rich rims and overgrowths. Separate rounded metamorphic grains also exist. The age probability-density distribution peaks for detrital zircon are at c. 1700, 1670, 1650, 1610, 1570 and 1530 Ma. These ages suggest Gothian orogenic rocks in the present west as the most probable principal source. Sedimentation occurred after c. 1530 Ma, the age of the youngest detrital zircon, indicating the existence of a previously unknown period of Mesoproterozoic sedimentation in southernmost Sweden. A homogeneous zircon overgrowth yielded a concordant Pb-207/Pb-206 age of 1439 +/- 5 Ma, which dates the migmatization and is close to the age of the Taghusa intrusion. We conclude that the burial of the sediments down to c. 20 km, their metamorphism and progressive migmatization took place concurrently with granitic magmatism, NE-SW compression, folding and shearing of the crust between 1460 and 1440Ma during the Danopolonian orogeny

Chemical and isotopic compositions of Archean magmatic and metasedimentary rocks and minerals from the Podolia domain, Ukrainian Shield

Zircons from the oldest magmatic and metasedimentary rocks in the Podolia domain of the Ukrainian shield were studied and dated by the U-Pb method on a NORDSIM secondary-ion mass spectrometer. Age of zircon cores in enderbite gneisses sampled in the Kazachii Yar and Odessa quarries on the opposite banks of the Yuzhnyi Bug River reaches 3790 Ma. Cores of terrigenous zircons in quartzites from the Odessa quarry as well as in garnet gneisses from the Zaval'e graphite quarry have age within 3650-3750 Ma. Zircon rims record two metamorphic events around 2750-2850 Ma and 1900-2000 Ma. Extremely low U content in zircons of the second age group indicates conditions of the granulite facies metamorphism in Paleoproterozoic within the Podolia domain. Measured data on orthorocks (enderbite-gneiss) and metasedimentary rocks unambiguously suggest existence of the ancient Paleoarchean crust in the Podolia (Dniester-Bug) domain of the Ukrainian shield. They contribute in our knowledge of scales of formation and geochemical features of the primordial crust