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.
We spend almost 50 percent of our total sleep time in stage 2 sleep, about 20 percent in REM sleep, and the remaining 30 percent in the other stages. Infants, by contrast, spend about half of their sleep time in REM sleep. During stage 1, which is light sleep, we drift in and out of sleep and can be awakened easily.