instruction:
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.
question:
Question: Do norepinephrine and ephedrine counteract the increase in cutaneous microcirculation induced by spinal anaesthesia?
Answer: Improved skin perfusion induced by spinal anaesthesia was not counteracted by the use of norepinephrine or ephedrine.
answer:
no

question:
Question: Is tobacco smoking associated with decreased semen quality?
Answer: Results demonstrated a decline in semen quality in a dose dependent tobacco smoking manner.
answer:
yes

question:
Question: Is insertion/deletion polymorphism of the angiotensin I-converting enzyme gene associated with restenosis after coronary stent placement?
Answer: The ACE DD genotype or D allele does not influence the 1-year clinical and angiographic outcome of patients undergoing coronary stent placement. These data suggest that routine determination of the ACE genotype may not help identify patients who are at a higher risk of thrombotic and restenotic events after coronary stent placement.
answer:
no