( They ( ( ( are now ) ( working ( to ( replicate ( the feat ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP are) (ADVP (RB now)) (VP (VBG working) (S (VP (TO to) (VP (VB replicate) (NP (DT the) (NN feat))))))) (. .)))
They are now working to replicate the feat.
(ROOT (S (S (VP (TO To) (VP (VB confirm) (NP (NP (DT the) (NN work)) (PP (IN of) (NP (DT another) (NN scientist))))))) (, ,) (NP (DT a) (NN scientist)) (VP (MD might) (VP (VB replicate) (NP (PRP$ their) (NN work)))) (. .)))