Timer to shut off portable air samplers.

Portable air samplers used at Los Alamos National Laboratory produce noise levels that make it difficult to conduct classes or tours in their vicinity. If air samplers are shut off during a class or tour, it may not be restarted at the end of the class or tour, preventing detection of low level airborne contamination or the measurement of a more significant release during a later operation. To enable clear communication during tours and classes a timer was designed and constructed that allows an air sampler to be shut of for a short, fixed duration and automatically restarted. A schematic and parts list is included.

Midodrine prevents orthostatic intolerance associated with simulated spaceflight.

Many astronauts after being weightless in space become hypotensive and presyncopal when they assume an upright position. This phenomenon, known as orthostatic intolerance, may interfere with astronaut function during reentry and after spaceflight and may limit the ability of an astronaut to exit a landed spacecraft unaided during an emergency. Orthostatic intolerance is more pronounced after long-term spaceflight and is a major concern with respect to the extended flights expected aboard the International Space Station and for interplanetary exploration class missions, such as a human mission to Mars. Fully effective countermeasures to this problem have not yet been developed. To test the hypothesis that alpha-adrenergic stimulation might provide an effective countermeasure, we conducted a 16-day head-down-tilt bed-rest study (an analog of weightlessness) using normal human volunteers and administered the alpha(1)-agonist drug midodrine at the end of the bed-rest period. Midodrine was found to significantly ameliorate excessive decreases in blood pressure and presyncope during a provocative tilt test. We conclude that midodrine may be an effective countermeasure for the prevention of orthostatic intolerance following spaceflight.