Who are the Thinkers leaders?

There are 4 S.I.Ns around the world responsible for sharing scientific and technological knowledge through small study groups: Dr. Bruno Candeias - S.I.N. Ambassador Brazil / Dr. Patrícia Fretes - S.I.N. Ambassador Paraguay / Dr. Fernando Duarte - S.I.N. Ambassador Portugal / Dr. Rick Kline - S.I.N. Ambassador USA