( ( In ( cases ( of ( positive feedback ) ) ) ) ( , ( ( an action ) ( ( produces ( ( a reaction ) ( which ( ( in turn ) ( intensifies ( ( the condition ) ( responsible ( for ( the ( first action ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NP (NNS cases)) (PP (IN of) (NP (JJ positive) (NN feedback))))) (, ,) (NP (DT an) (NN action)) (VP (VBZ produces) (NP (NP (DT a) (NN reaction)) (SBAR (WHNP (WDT which)) (S (PP (IN in) (NP (NN turn))) (VP (VBZ intensifies) (S (NP (DT the) (NN condition)) (ADJP (JJ responsible) (PP (IN for) (NP (DT the) (JJ first) (NN action)))))))))) (. .)))
In cases of positive feedback, an action produces a reaction which in turn intensifies the condition responsible for the first action.
(ROOT (S (NP (JJ Positive) (NN feedback)) (VP (VP (VBZ intensifies) (NP (NP (DT a) (NN change)) (PP (IN in) (NP (NP (DT the) (NN body) (POS 's)) (JJ physiological) (NN condition))))) (CONJP (RB rather) (IN than)) (VP (VBG reversing) (NP (PRP it)))) (. .)))