( This ( apparently ( ( ( acts ( as ( ( a signal ) ( for ( the ( pyloric sphincter ) ) ) ) ) ) ( to close ) ) . ) ) )
(ROOT (S (NP (DT This)) (ADVP (RB apparently)) (VP (VBZ acts) (PP (IN as) (NP (NP (DT a) (NN signal)) (PP (IN for) (NP (DT the) (JJ pyloric) (NN sphincter))))) (S (VP (TO to) (VP (VB close))))) (. .)))
This apparently acts as a signal for the pyloric sphincter to close.
(ROOT (S (S (VP (VBG Acting) (PP (IN like) (NP (NNS drawstrings))) (S (VP (TO to) (VP (VB close) (PRT (RP off)) (NP (DT the) (JJ alimentary) (NN canal))))))) (, ,) (NP (DT the) (NN sphincter)) (VP (VBZ regulates) (NP (NP (DT the) (NN passage)) (PP (IN of) (NP (NP (NN material)) (PP (IN between) (NP (NNS compartments))))))) (. .)))