It’s a head-scratcher. The University of Texas at Austin scrambled yesterday to account for a collection of brains that disappeared from one of its research centers. Preserved in jars of formaldehyde, the organs were taken from autopsies of mentally ill patients. It was rumored and later debunked that the Austin clock-tower sniper was among them. UT officials finally said the missing parts ended up as biological waste. But skeptics wonder if that explanation is merely a head fake.