As rates of depression and suicide in youth spike, experts are asking whether social media makes kids depressed — or do depressed kids simply spend more time on social media?

A new study provides answers. Researchers at UC San Francisco found that as preteens used more social media, their depressive symptoms increased. Yet the reverse wasn’t true — a rise in depressive symptoms didn't predict a later increase in social media use.

With its fascinating ability to regrow entire limbs and internal organs, the Mexican axolotl is the ideal model for studying regeneration. Scientists from the lab of Elly Tanaka at IMBA now found a factor that tells cells which part of the arm to regenerate - and used it to reprogram the identity of cells as they develop. This breakthrough for the regeneration research field has implications for tissue engineering, including in human tissues. The study was published in the journal Nature today.

Derek Leben, in his new book AI Fairness: Designing Equal Opportunity Algorithms (MIT Press, 2025), tackles this pressing issue, offering a philosophical framework to evaluate and mitigate the inherent biases of AI. Leben draws inspiration from the work of the philosopher John Rawls, proposing a theory of algorithmic justice built upon core principles including autonomy, equal treatment, and equal impact. These principles, he argues, should guide the design and deployment of AI systems, ensuring they meet a "minimally acceptable level of accuracy," avoid irrelevant attributes, and provide equal opportunity.