Think boys mature faster than girls?  Or vice versa?   Let's go to the MRI!

Researchers at Oregon Health&Science University and Washington University in St. Louis say they can now accurately predict a young person's age simply by taking an MRI brain scan and analyzing it with a numerical model. 
Since man has been able to think about big issues, such as why we are the way we are, it has been known that what happens during the daytime, including emotional stress and physical activity, can affect sleep. When an animal is active and awake, research shows, regulatory substances also build up in the brain that induce sleep.

But what in wakefulness is driving these sleep regulatory substances?  Sleep disorders affect between 50 and 70 million Americans, according to the Institute of Medicine of the National Academies. The Institute also estimates the lost productivity and mishaps of fatigue cost businesses roughly $150 billion, while motor vehicle accidents involving tired drivers cost at least $48 billion a year.