( ( Sleep ( Studies Breathing ) ) ( ( is ( ( ( usually automatic ) and ) ( controlled ( by ( centers ( in ( ( the brain ) ( that ( ( respond ( to ( ( the levels ) ( of ( oxygen ( and ( carbon dioxide ) ) ) ) ) ) ) ( in ( the blood ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Sleep) (NNPS Studies) (NNP Breathing)) (VP (VBZ is) (UCP (ADJP (RB usually) (JJ automatic)) (CC and) (VP (VBN controlled) (PP (IN by) (NP (NP (NNS centers)) (PP (IN in) (NP (NP (DT the) (NN brain)) (SBAR (WHNP (WDT that)) (S (VP (VBP respond) (PP (TO to) (NP (NP (DT the) (NNS levels)) (PP (IN of) (NP (NN oxygen) (CC and) (NN carbon) (NN dioxide))))) (PP (IN in) (NP (DT the) (NN blood))))))))))))) (. .)))
Sleep Studies Breathing is usually automatic and controlled by centers in the brain that respond to the levels of oxygen and carbon dioxide in the blood.
(ROOT (S (NP (DT The) (NN brain)) (VP (VBP stem) (S (NP (NP (NN monitor)) (PRN (-LRB- -LRB-) (PRP s) (-RRB- -RRB-))) (NP (NP (DT the) (NN level)) (PP (IN of) (NP (NP (NN carbon) (NN dioxide)) (PP (IN in) (NP (DT the) (NN blood)))))))) (. .)))