Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.

Ex Input:
Question: Is the dorsal motor nucleus of the vagus an obligatory trigger site of Parkinson 's disease : a critical analysis of alpha-synuclein staging?
Answer: Our results demonstrate a predominant involvement of the SN and NBM in PD but do not support the existence of a medullary induction site of alpha Syn pathology in all PD brains.

Ex Output:
no

Ex Input:
Question: Does gPR39 activate proliferation and differentiation of porcine intramuscular preadipocytes through targeting the PI3K/AKT cell signaling pathway?
Answer: It indicated that GPR39 was a transducer of Zn(2+), and enhanced proliferation and differentiation of porcine intramuscular preadipocytes through activation of the PI3K/Akt signaling pathway.

Ex Output:
yes

Ex Input:
Question: Is inflammatory infiltrate ( prostatitis ) in whole mounted radical prostatectomy specimens from black and white patients an etiology for racial difference in prostate specific antigen?
Answer: To our knowledge no significant racial difference exists in the extent of inflammatory infiltrate, and inflammation was not the etiology of the racial difference in serum PSA levels in this clinically localized prostate cancer cohort.

Ex Output:
no