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Defined skin commensal bacteria elicit a dermal dendritic-cell-dependent, long-lasting, commensal-specific CD8+ T-cell response that promotes protection against pathogens while preserving tissue homeostasis.
The measurement of the rotational periods of 30 cool stars in the 2.5-billion-year-old cluster NGC 6819 allows the calibration of gyrochronology — the determination of a star’s age on the basis of its rotation period — over a much broader age range than hitherto, meaning that it might be possible to determine the ages of many cool stars in the Galactic field with a precision of roughly 10 per cent.
