4 a.m.

1. 1979 - La superpetroliera Exxon Valdez si infrange su una scogliera nello stretto Prince William del golfo di Alaska, disperdendo in mare 38 milioni di litri di petrolio 4 a.m.

2. 1989 - Il reattore atomico di Three Miles Island esplode creando il più grande disastro nucleare della storia americana 5 a.m.

3. March 28, 1979 at Three Mile Island, a nuclear plant in Pennsylvania. An accident occurred from 4-6 am, in which operators were too fatigued to notice right away when coolant water was lost. When they did notice, they were not alert enough to take care of the problem efficiently. June 9, 1985 at Davis-Besse, a nuclear power generating reactor at Oak Harbor, Ohio. At about 1:30am, a control operator continually made the incorrect operations in response to a shortage of cooler water, resulting in a potentially serious situation. Disaster was prevented when the workers for the next shift arrived and took care of the problem. April, 1986 at Chernobyl, a nuclear reactor in Ukraine. With critical automatic safety systems shut off, the reactor began to overheat at about 1:30am. The sleepy shiftworkers didn't think to turn the automatic safety systems back on, but instead turned off the cooling system, causing the reactor to get too hot. In result of the explosionthat occurred, many people were severely affected by the radiation. January 6, 1986 at the Kennedy Space Center. Before the Columbia space shuttle was to be launched, an over tired operator pressed the wrong button, the button that released needed fuel from the shuttle's tank. Fortunately, the error was detected in time to cancel the launch. January, 1986 - Poor decisions were made by sleep deprived managers resulting in the Challenger catastrophe. August 1988 - Peach Bottom Nuclear Reactor in Pennsylvania was shut down because workers were found sleeping on the job. March 24, 1989 - The Exxon Valdez oil spill off the coast of Alaska had major consequences, including the cost of $41 million to help 800 birds and a few hundred sea otters. Many other animals could not be helped. An estimated 36,000 birds and 3000 otters died. The total estimated clean up cost was about $2 billion!

4. 1986 - Lo Space Shuttle esplode dopo il decollo. 11.39 a.m.

5. Accident frequency Moresleep, fewer accidents Less sleep, more accidents 2,800 2,700 4,200 2,600 4000 2,500 3,800 2,400 3,600 Spring time change (hour sleep loss) Fall time change (hour sleep gained) Monday after time change Monday before time change Sleep Deprivation

14. During sleep deprivation, overall performance typically declines - primarily as a result of a reduction in speed.

15. Sleep deprivation impairs alertness, cognitive performance, and mood.

16. …the more effective triazolam and zolpidem* were for inducing sleep, the greater the performance decrement at peak of drug effect. …triazolam appeared to impair basic field survival skills. *Triazolam and zolpidem are sleep inducing drugs.

17. We found that caffeine is safe and effective in sustaining performance when sleep is not possible yet alertness and cognitive performance must be maintained.