Depression may be challenging to assess in a patient with dementia. In patients with AD, the presence of depression may range from 6% to 30%, depending on the diagnostic criteria employed (Cummings et al., 1995). The prevalence and course of depression in dementia are controversial, due to several confounding factors.
Astronauts use space shuttles(trasport people and equipment), Space probes (robotic exploration, Spacecrafts (trasport crew, equipment, and other technologies).
But when the Apollo astronauts were on the moon, where there is no air, or when the Shuttle astronauts need to contact earth through the vacuum of space, radio has to be used because radio waves are electromagnetic waves and can travel easily in a vacuum. + 36 others found this useful. David Scott.