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 anticytomegalovirus antibody titres associated with caregiving burden in younger caregivers?
Answer: These data suggest that in the absence of immunosenescence, the chronic stress of caregiving is not sufficient to compromise the immune response to persistent CMV infection. However, an indirect mechanism to poorer health in caregivers might be via adoption of disadvantageous health behaviours in response to stress. Statement of contribution What is already known on this subject? Older caregivers of spouses with dementia show a poorer immune response against latent viruses when compared to age- and sex-matched controls. Younger parental caregivers of children with developmental disabilities show a poorer antibody response to vaccination. What does this study add? The study showed no association between caregiving stress and CMV antibody titre in young caregivers. There were higher CMV antibody titres in the caregivers who engage in unhealthy behaviours.

Ex Output:
no


Ex Input:
Question: Does transient ischemia limit subsequent ischemic regional dysfunction in humans : a transesophageal echocardiographic study during minimally invasive coronary artery bypass surgery?
Answer: Ischemic dysfunction was precipitated by the 5-min LAD occlusion, as shown by the increase in LVWMS and pulmonary artery pressure. However, a 5-min coronary occlusion and the resulting ischemia do not alter regional left ventricular systolic function during subsequent ischemia in humans.

Ex Output:
no


Ex Input:
Question: Is directional distribution of neoplasia in Barrett 's esophagus influenced by distance from the gastroesophageal junction?
Answer: Single-center study may limit external validity.

Ex Output:

no