In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Input: Consider Input: Context: Previous follow-up studies indicate that increased visual cortical, ventral cingulate and subcortical responses of depressed individuals to sad facial stimuli, but not happy stimuli could represent reversible markers of disease severity. We hypothesized that greater responses in these areas to sad stimuli, but not happy stimuli, would predict better subsequent clinical outcome. We also explored areas that would predict a poor outcome.', 'Twelve melancholically depressed individuals in the early stages of antidepressant treatment in a secondary care setting participated in two experiments comparing responses to varying intensities of sad and happy facial stimuli, respectively, using event related functional MRI. They repeated the experiments after a mean delay of 12 weeks of treatment.', 'There was a variation in response to treatment. Greater right visual cortex and right subgenual cingulate (R-BA25) responses to sad stimuli, but not happy stimuli, in the early stages of treatment were associated with a good clinical outcome. Greater ventrolateral prefrontal cortex responses to either stimulus type were associated with a relatively poor outcome.\Question: Do subgenual cingulate and visual cortex responses to sad faces predict clinical outcome during antidepressant treatment for depression?

Output: The sample size was modest and patients were taking a variety of antidepressants.

Input: Consider Input: Context: Old compared with young adults walk with reduced ankle and increased hip mechanical output. We examined the idea that age, leg strength, or both are related to the age-related changes in mechanical output during gait.', 'Healthy young (n = 32, age 21.5 years) and old adults (n = 32, age 76.8 years) participated in biomechanical gait analyses at 1.5 m/s and were also measured for maximal leg strength.', 'Analysis 1 confirmed previous data as old compared with young adults walked with 50 % more hip positive work and 18 % less ankle positive work. Analysis 2 showed that leg strength did not affect gait kinetics in groups of subjects with similar ages. In a weak young and a strong old group, Analysis 3 showed that old adults still walked with 23 % greater hip positive work. The group by joint interaction in Analysis 4 was suggestive of an even greater reliance on hip and less reliance on ankle work in weak compared with strong old adults.\Question: Do age and muscle strength mediate the age-related biomechanical plasticity of gait?

Output: Age and leg strength both contribute to the age-related changes in mechanical output during gait. Exercise prescription, normally targeting the knee extensors, should also involve ankle and hip muscles.

Input: Consider Input: Context: People with a history of rheumatic fever (RF) are at high risk of recurrent attacks and of developing rheumatic heart disease following a streptococcal throat infection. Giving penicillin to these people can prevent recurrent attacks of RF and subsequent rheumatic heart disease. However, there is no agreement on the most effective method of giving penicillin.', 'To assess the effects of different penicillin regimens and formulations for preventing streptococcal infection and RF recurrence.', 'We searched the Controlled Trials Register (Cochrane Library Issue 2, 2001), Medline (January 1966-July 2000), Embase (January 1985-July 2000), reference lists of articles, and contacted experts in the field.', 'Randomised and quasi-randomised studies comparing: (i) oral with intramuscular penicillin; and (ii) 2- or 3-weekly with 4-weekly intramuscular penicillin in patients with previous RF.', 'Two reviewers independently assessed trial quality and extracted data.', 'Six studies were included (1,707 patients). Data were not pooled because of clinical and methodological heterogeneity of the trials. Four trials (1,098 patients) compared intramuscular with oral penicillin and all showed that intramuscular penicillin was more effective in reducing RF recurrence and streptococcal throat infections than oral penicillin. One trial (360 patients) compared 2-weekly with 4-weekly intramuscular penicillin. Penicillin given every 2 weeks was better at reducing RF recurrence (relative risk (RR) 0.52, 95% confidence interval (CI): 0.33-0.83) and streptococcal throat infections (RR 0.60, 95% CI: 0.42-0.85). One trial (249 patients) showed that 3-weekly intramuscular penicillin injections reduced streptococcal throat infections (RR 0.67, 95% CI: 0.48-0.92) compared with 4-weekly intramuscular penicillin.\Question: Is intramuscular penicillin more effective than oral penicillin in secondary prevention of rheumatic fever -- a systematic review?
Output: Intramuscular penicillin seemed to be more effective than oral penicillin in preventing RF recurrence and streptococcal throat infections. Two-weekly or 3-weekly injections appeared to be more effective than 4-weekly injections. However, the evidence is based on poor-quality trials and the use of outdated formulations of oral penicillin.