Cluster headaches can last from 15 minutes to several hours at a time, and can recur daily for weeks in a row, and then go away until another “cluster” episode. Although there is no known cure for ...

Galaxies and clusters are the ensembles of stars and other astronomical objects bound together by gravitational forces. Galaxies are ordered into galaxy groups, which are in turn organised into ...

FNR is a global regulator of the Escherichia coli aerobic-anaerobic growth transition and relies on an [Fe-S] cluster cofactor to control its oxygen-dependent activity. Details of the chemical ...