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 ...

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

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 ...

Air pollution is a leading cause of mortality, but controls on vehicle emissions have achieved reductions in deaths related to fine particulate matter pollution. Electrification of vehicles and ...

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 ...

Posttranscriptional regulation of gene expression by RNA-binding proteins can enhance the speed and robustness of cell state transitions by controlling RNA stability, localization, or if, when, or ...

PNAS: Welcome to Science Sessions, the podcast of the Proceedings of the National Academy of Sciences, where we connect you with Academy members, researchers, and policymakers. Join us as we explore ...

We thank Fitzgerald (1) for the interest in our study. Fitzgerald’s letter focuses on our analyses examining differences between US states that employed COVID-19 vaccine mandates and those that ...