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: Are flavones from Erythrina falcata modulators of fear memory?
Answer: Our results demonstrate that vitexin, isovitexin and diosmetin-6-C-glucoside and flavonoidic fractions resulted in a significant retention of fear memory but did not prevent the extinction of fear memory. These results further substantiate that the treatment with pure flavonoids or flavanoid-rich fractions might represent potential therapeutic approaches for the treatment of neurocognitive disorders, improvement of memory acquisition and spontaneous recovery of fear.
answer:
yes

question:
Question: Is unexplained elevated maternal serum alpha-fetoprotein predictive of adverse perinatal outcome in an indigent urban population?
Answer: Elevated maternal serum alpha-fetoprotein levels offer little if any additional predictive value for adverse perinatal outcome in populations already at high risk for such outcomes on the basis of obstetric or socioeconomic criteria.
answer:
no

question:
Question: Does right atrial overdrive pacing prevent atrial fibrillation after coronary artery bypass surgery?
Answer: Atrial overdrive pacing and bradycardia prevention pacing were not effective in the prevention of AF after CABG.
answer:
no