Feature

  1. Health & Medicine

    Standing Up to Gravity

    Studies in space can help physicians better understand a disorder in which patients get faint or dizzy while standing.

    By Damaris Christensen
  2. Astronomy

    Cosmic Dawn

    New computer simulations suggest that the first stars in the universe were extremely massive and left behind gamma-ray bursts that may already have been detected by telescopes orbiting Earth.

    By Ron Cowen
  3. Health & Medicine

    What Activates AIDS?

    New studies suggest that a natural process called immune activation—the signaling that alerts immune cells of foreign invaders—plays a key role in explaining why infection with the human immunodeficiency virus progresses to AIDS more quickly in some people than in others.