A machine-learning system has been developed that can monitor heart rate using facial video clips that are captured passively by the user-facing camera during everyday smartphone use. The system meets industry accuracy standards for heart-rate measurement and is as accurate as wearable technology for measuring daily resting heart rate.

A fertilized egg’s first few divisions rely on proteins stored in fibrous structures. The ordered nature of these structures and clues about their function are revealed.

A large-scale experiment tested the impact of changing the Bluesky feed-ranking algorithm on political content and perceptions during the 2024 US presidential election. By making feeds more representative of users, the ‘diversified extremity’ algorithm reduced exposure to polarizing content and made perceptions of social norms more accurate, without reducing user enjoyment.

One in six Internet-using adolescents in parts of Africa and Asia faced technology-facilitated sexual abuse in 2020–21. As digital access expands globally, better protection is crucial.