maintains a surprisingly buoyant tone throughout , notwithstanding some of the writers ' sporadic dips 
(ROOT (S (VP (VBZ maintains) (NP (DT a) (ADJP (RB surprisingly) (JJ buoyant)) (NN tone)) (ADVP (IN throughout)) (, ,) (PP (VBG notwithstanding) (NP (NP (DT some)) (PP (IN of) (NP (NP (DT the) (NNS writers) (POS ')) (JJ sporadic) (NNS dips))))))))
(ROOT (S (VP (VBZ ) (NP (DT ) (ADJP (RB ) (JJ )) (NN )) (ADVP (IN )) (, ) (PP (VBG ) (NP (NP (DT )) (PP (IN ) (NP (NP (DT ) (NNS ) (POS )) (JJ ) (NNS ))))))))