Several are noted 
( Several ( are noted ) )
(ROOT (S (NP (JJ Several)) (VP (VBP are) (VP (VBN noted)))))
Nothing has been recorded.
( Nothing ( ( has ( been recorded ) ) . ) )
(ROOT (S (NP (NN Nothing)) (VP (VBZ has) (VP (VBN been) (VP (VBN recorded)))) (. .)))