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: Is allogeneic red blood cell transfusion an independent risk factor for the development of postoperative bacterial infection?
Answer: These data support the hypothesis that allogeneic red cell transfusion is an independent risk factor for the development of postoperative bacterial infection in patients undergoing colorectal surgery. This association provides further reason to minimise exposure to allogeneic transfusions in the perioperative setting.

Answer: yes

Question: Question: Are cognitive-behavioral phenotypes of Williams syndrome associated with genetic variation in the GTF2I gene , in a healthy population?
Answer: These findings implicate the GTF2I gene in the neurogenetic basis of social communication and social anxiety, both in Williams syndrome and among individuals in healthy populations.

Answer: yes

Question: Question: Do mental health service use among high school students exposed to interpersonal violence?
Answer: Associations between adolescent violence exposure and mental health service contact vary by forms of exposure. Outreach to a broader set of exposed youth may reduce the impact of violence and its consequences for vulnerable students.

Answer:
yes