Other studies have confirmed that it is possible to induce insulin resistance in normal volunteers simply with sleep restriction to four hours per night, even with a single night. (idmprogram.com)
A number of well - controlled European studies have carefully explored the action of hallucinogens on the brains of normal volunteers [see «Psychedelic Healing?» (scientificamerican.com)
Reference ranges are established by testing NORMAL volunteer donors and are verified every year with more volunteer NORMAL donors. (wellnessmama.com)