Northwestern Medicine scientists have discovered how cells responsible for hair growth perceive physical forces in their ...

When the force applied was less than 7 piconewtons, the bond between PD-1 and the ligand got stronger and lasted longer. When the force was higher than 8, the bond weakened and broke more easily.

Basically, the questions were: Should all use of physical force by parents be avoided, or are there cases where they might feel it is appropriate? When a strong-willed or willful child is ...