(S (S (BASENP (NN One-fourth)) (VP (VBP admit) (SBAR (S (BASENP (PRPD their) (NN sleep) (NNS problems)) (VP (MD do) (VP (VB have) (NP (BASENP (DT an) (NN impact)) (PP (IN on) (BASENP (PRPD their) (JJ daily) (NNS lives)))))))))) (PERIOD .))