(S (S (BASENP (NN Human) (NNS rights) (NNS activists)) (VP (VBP have) (VP (VBN speculated) (SBAR (IN that) (S (BASENP (NNP Uribe)) (VP (MD might) (VP (VB have) (VP (VBN influenced) (BASENP (DT the) (NN visa) (NN denial)))))))))) (PERIOD .))