(S (S (PP (PP (IN From) (BASENP (NN 1978))) (PP (TO to) (BASENP (NN 2006)))) (COMMA ,) (S (BASENP (PRP he)) (VP (VP (VP (VP (VBD participated) (PP (IN in))) (COMMA ,) (VP (VB lead))) (CC and) (VP (VBD organized))) (NP (QP (ADVP (RBR more) (IN than)) (NN 45)) (BASENP (JJ Arctic) (NNS expeditions)))))) (PERIOD .))