00345nam a2200121Ia 4500008004100000022001400041040001100055100002700066245001200093260009100105300001600196300001100212251112s9999||||xx |||||||||||||| ||und||  a0036-8075  aCNCLSA  aDaniel E. Koshland Jr. 0aScience  cFebruary 12, 1993bThe American Association for the Advancement of ScienceaWashington  aP. 865-1990  bV. 259