( ( These changes ) ( ( were ( ( observed ( more often ) ) ( among ( women ( in ( the ( two ( experimental groups ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT These) (NNS changes)) (VP (VBD were) (VP (VBN observed) (ADVP (RBR more) (RB often)) (PP (IN among) (NP (NP (NNS women)) (PP (IN in) (NP (DT the) (CD two) (JJ experimental) (NNS groups))))))) (. .)))
These changes were observed more often among women in the two experimental groups.
(ROOT (S (NP (JJ Multiple) (NN fission)) (VP (VBZ is) (ADVP (RBR more) (RB often)) (VP (VBN observed) (PP (IN among) (NP (NNS protists))))) (. .)))