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: Are arterial stiffness and pulse wave reflection increased in patients suffering from severe periodontitis?
Answer: The results of this study confirm the association between periodontal inflammation and increased cardiovascular risk shown by impaired vascular health in case of severe periodontitis. As impaired vascular health is a common finding in patients suffering from severe periodontal disease a concomitant routine cardiovascular evaluation may be advised.

Ex Output:
yes

Ex Input:
Question: Is human endogenous retrovirus ( HERV ) expression induced by treatment with the histone deacetylase ( HDAC ) inhibitors in cellular models of HIV-1 latency?
Answer: We show that HDAC inhibitors did not substantially increase the transcription of the analysed HERV env or pol genes, suggesting that histone acetylation is not crucial for controlling HERV expression in these experimental models and in ex vivo primary human T cells. Importantly, this indicates that unwanted HERV expression does not appear to be a barrier to the use of HDAC inhibitors in HIV-1 cure strategies.

Ex Output:
no

Ex Input:
Question: Are pregnancy-associated plasma protein a levels decreased in obstetric cholestasis?
Answer: In this study, the first trimester PAPP-A levels in the obstetric cholestasis cases were found to be significantly lower than the control group. Low PAPP-A levels should be a warning for obstetric cholestasis.

Ex Output:
yes