( ( At ( ( the end ) ( of ( the ( breeding season ) ) ) ) ) ( , ( and ( ovariectomy ( ( ( produces ( ( ( no change ) ( in ( ( ( LH levels ) ( -LRB- ( ( ( no interaction ) ( with feedback ) ) -RRB- ) ) ) 2 ) ) ) -RRB- ) ) ( those ( that ( fail ( to ( ( produce ( endogenous ( circannual cycles ) ) ) ( in ( ( the absence ) ( of ( environmental cues ) ) ) ) ) ) ) ) ) ) - ) ) ) ) )
(ROOT (S (PP (IN At) (NP (NP (DT the) (NN end)) (PP (IN of) (NP (DT the) (VBG breeding) (NN season))))) (, ,) (NP (NNP and)) (ADVP (RB ovariectomy)) (VP (VBZ produces) (PRN (NP (NP (DT no) (NN change)) (PP (IN in) (NP (NP (NNP LH) (NNS levels)) (PRN (-LRB- -LRB-) (NP (NP (DT no) (NN interaction)) (PP (IN with) (NP (NN feedback)))) (-RRB- -RRB-)) (NP (CD 2))))) (-RRB- -RRB-)) (NP (NP (DT those)) (SBAR (WHNP (WDT that)) (S (VP (VBP fail) (S (VP (TO to) (VP (VB produce) (NP (JJ endogenous) (JJ circannual) (NNS cycles)) (PP (IN in) (NP (NP (DT the) (NN absence)) (PP (IN of) (NP (JJ environmental) (NNS cues))))))))))))) (: -)))
At the end of the breeding season, and ovariectomy produces no change in LH levels (no interaction with feedback) 2) those that fail to produce endogenous circannual cycles in the absence of environmental cues -
(ROOT (S (NP (JJ Circannual) (JJ behavioral) (NNS rhythms)) (VP (VBP are) (VP (VBN linked) (PP (TO to) (NP (NP (DT the) (JJ yearly) (NN cycle)) (PP (IN of) (NP (NNS seasons))))))) (. .)))