00337nam a2200121Ia 4500008004100000022001400041040001100055100001900066245001200085260009000097300001700187300001100204251112s9999||||xx |||||||||||||| ||und||  a0036-8075  aCNCLSA  aFloyd E. Bloom 0aScience  cNovember 5, 1999bThe American Association for the Advancement of ScienceaWashington  aP. 1041-1804  bV. 286