A newly discovered fossil record of steroid molecules, spanning 1.64 billion years, points to ancient organisms in the eukaryotic domain being capable of only early steps in the synthesis of sterol molecules.

Deep reinforcement learning has been used to improve computer code by treating the task as a game — with no special knowledge needed on the part of the player. The result has already worked its way into countless programs.

Hybrid molecules containing organic and inorganic components were assembled through bottom-up synthesis into a continuous network of interpenetrating molecular-scale organic and inorganic ionic domains. The resulting material, called elastic ceramic plastic, shows ceramic-like hardness and strength, rubber-like deformability and resilience, and plastic-like mouldability.

A previously unknown neural circuit in the brains of female mice is activated during infanticidal behaviour, and reciprocally inhibits another circuit that promotes maternal-care behaviour. These circuits show opposing changes in excitability when female mice become mothers, explaining the switch in young-directed behaviours that occurs with motherhood.