Clinical feasibility trial of a motion detection system for fall prevention in hospitalized older adult patients.

The purpose of this pilot study was to test the feasibility of a wireless 5-sensor, motion detection system (5S-MDS) with hospitalized older adults. Interventions to prevent hospital-based falls in older adults are important to reduce morbidity, mortality, and health care costs. Wearable motion sensors, which track and wirelessly transmit body movements, may identify human movement patterns that immediately precede falls, thus allowing early prevention.

Modeling international cooperation in human space exploration for the twenty-first century.

The policy process of international cooperation in space exploration. including optimistic and pessimistic scenarios for the twenty-first century, is modeled and examined in this study. In the optimistic scenario, international cooperation involves a balanced and interdependent distribution of capabilities between states, their respective national space agencies and communities of space scientists and space engineers.

A ground-based study for a shuttle BRIC experiment on gravity effects on gene expression.

A BRIC (Biological Research In a Canister) experiment to investigate the effects of reduced gravity at the molecular level using Arabidopsis has been initiated. In preparation for a space flight experiment, a series of ground-based studies were conducted. Results from these studies indicate that: 1) up to 20,000 seeds can be germinated on a 100 mm diameter Petri plate, 2) nylon membrane is the best surface for recovery of plant material after freezing, 3) depending on the age of the seedlings at the time of freezing, 20 to 40 g of tissue can be obtained from Petri plates that fit in a single canister; 4) tissue from one canister yields adequate amounts of RNA to perform differential display to isolate gravity-regulated genes.

Moderate sodium restriction does not alter lower body negative pressure tolerance.

Hypothesis: Space travel with exposure to microgravity leads to a significant reduction in orthostatic tolerance on return to Earth, for which countermeasures are only partially successful. The purpose of this study was to examine the effect of moderate dietary sodium restriction on tolerance to LBNP.

Methods: Eight healthy men, age 25.

The heart is not necessarily empty at syncope.

Background: Although extensively investigated, the mechanism(s) of post-spaceflight orthostatic intolerance has not been elucidated. Several researchers have proposed that the "trigger" for syncope is an empty ventricle, initiated when a hypercontractile state, possibly due to a sudden surge in epinephrine, causes the walls of the left ventricle to touch leading to a profound sympatho-inhibition and intense vagal stimulation.

Hypothesis: A markedly reduced left ventricular end systolic volume (LVESV) achieved during progressive, presyncopal-limited lower body negative pressure (LBNP) is the trigger for syncope.