(S (S (BASENP (DT The) (NN study)) (VP (VBZ has) (VP (VBN been) (VP (VBN published) (PP (IN in) (NP (NP (BASENP (DT this) (NN week) (POS 's)) (NN edition)) (PP (IN of) (NP (BASENP (DT the) (NN journal)) (BASENP (NNP Nature)))))))))) (PERIOD .))