The rate equations for a continuous four level laser are solved in this letter, taking into account the finite lower level lifetime and the crystal field splitting of the laser levels.

The bottom line here is the more fiber you eat, perhaps, a lower level of hormone in your body, and therefore, a lower lifetime risk of developing breast cancer.

Early bouts of joblessness, or starting in a lower-level job with lower pay, can mean lower levels of career attainment and earnings over a lifetime.