“ PCAST shall be composed of not more than 16 members, one of whom shall be the Assistant to the President for Science and Technology (‘‘Assistant’’) , and 15 of whom shall be distinguished individuals from the nonfederal sector appointed by the President. The nonfederal sector members shall be representative of the diverse perspectives and expertise in this Nation's investments in science and technology. The Assistant to the President for Science and Technology shall co-chair PCAST with a nonfederal sector member selected by the President. ”