In research using laptop screens, cats quickly learned to associate sounds and animations. Image credit: Sheila Fitzgerald/Shutterstock.

Recent studies in mice suggest that how the egg cells hold onto and get rid of their proteins may be key to this survival. Although most proteins are renewed every few days, two studies show that some ...

Hu et al. (1) report the construction of a chimeric coronavirus (rOC43-CoV2-S) in which the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replaces that of the ...

Edited by Mark Thiemens, University of California San Diego, La Jolla, CA; received June 19, 2024; accepted September 5, 2024 ...

Neither of the two competing, long-debated explanations about birth rate declines may be entirely accurate. There could be big implications for policy and programs related to family planning for many ...

Mammalian organs, including the lung and the kidney, often use a branched design to maximize their functional capacity and efficiency. Lung formation requires two developmental processes: branching ...

The study of human behavior traditionally focuses on the here and now. After all, people cannot take surveys or participate in experiments if they are not alive today. Here, we propose a way to ...

Japanese macaque (Macaca fuscata) nursing a newborn. Image credit: Angela Stojan (University of Vienna, Vienna, Austria). Birth and maternal mortality in Japanese macaques The heads of fetuses in some ...

The Proceedings of the National Academy of Sciences (PNAS) wants everyone visiting PNAS.org to feel welcome. Through our platform provider, Atypon, this website meets Level AA of the World Wide Web ...

Edited by Joseph Kieber, The University of North Carolina at Chapel Hill, Chapel Hill, NC; received July 29, 2024; accepted September 9, 2024 ...

Most humanists and scientists now agree that science is special in its relationship to the real world, more special than are other human activities—religion and politics, for instance. But ...