Rivastigmine (sold under the trade name Exelon) is a parasympathomimetic or cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer's type and dementia due to Parkinson's disease.
Quick Answer. According to the University of Washington, cows sleep for approximately 3.9 hours per day, meaning that they spend about 16.9 percent of the day sleeping. Adult humans sleep for approximately 8 hours per day, which represents 33.3 percent of the day. Human infants sleep approximately 16 hours per day.
Stage N2 occurs throughout the sleep period and represents 45-55% of total sleep time. Stage N3 (delta or slow wave sleep) occurs mostly in the first third of the night and constitutes 5-15% of total sleep time. REM represents 20-25% of total sleep time and occurs in 4-5 episodes throughout the night.