Mixing causes the precipitant and protein to collide. It has been termed a "universal" precipitant for polar proteins. In the laboratory it is a common precipitant and cryoprotectant in protein crystallography. In adults, loneliness is a major precipitant of depression and alcoholism. For example, sleep deprivation may act as a precipitant of epileptic seizures. Bush camping is a common precipitant of infection so particular care is required. A minor bump to the head is the most commonly reported precipitant. Once the precipitant is removed, the enzyme activity returns to normal levels. The bis(dicarbollide) [Co(CBH)] has been used as a precipitant for removal of Cs from radiowastes. Minor head trauma is a common attack precipitant, so FHM sufferers should avoid contact sports.