Association of Space Flight With Problems of the Brain and Eyes.

This study explores the association of cerebrospinal fluid pressure and brain upward shift with space flight–associated neuroocular syndrome in postflight astronauts.

Cavity mode identification for coherent terahertz emission from high-Tc superconductors.

Stacks of intrinsic Josephson junctions in BiSrCaCuO emit intense and coherent terahertz waves determined by the internal electromagnetic cavity resonance. We identify the excited transverse magnetic mode by observing the broadly tunable emissions from a nearly square stack and simulating the scattering spectrum. We employ a wedge-type interferometer to measure spatially-integrated power independently of the far-field pattern.