A large number of the valley networks scarring Mars's surface were carved by water melting beneath glacial ice, not by free-flowing rivers as previously thought, according to new research. The findings effectively throw cold water on the dominant 'warm and wet ancient Mars' hypothesis, which postulates that rivers, rainfall and oceans once existed on the red planet.
The study of cellular dynamics is crucial to understand how cells develop and how diseases progress. Scientist have now created 'scVelo' - a machine learning method and open source software to estimate the dynamics of gene activity in single cells. This allows biologists to robustly predict the future state of individual cells.