00334nam a2200121Ia 4500008004100000022001400041040001100055100001900066245001200085260008800097300001600185300001100201251112s9999||||xx |||||||||||||| ||und||  a0036-8075  aCNCLSA  aFloyd E. Bloom 0aScience  cNovember 1, 1996bThe American Association for the Advancement of ScienceaNew York  aP. 701-1576  bV. 274