Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Example Input: Context: Coming off their home win over the Rams, the Bengals flew to Bill Walsh Field at Monster Park for a Saturday night interconference duel with the San Francisco 49ers. After a scoreless first quarter, Cincinnati trailed early in the second quarter as 49ers QB Shaun Hill got a 3-yard TD run. Afterwards, the Bengals would take the lead as kicker Shayne Graham managed to get a 24-yard field goal, while QB Carson Palmer completed a 52-yard TD pass to WR Chris Henry. San Francisco would end the half with Hill completing a 17-yard TD pass to TE Vernon Davis. In the third quarter, the 49ers increased their lead with kicker Joe Nedney getting a 29-yard and a 38-yard field goal. In the fourth quarter, Cincinnati tried to respond as Graham kicked a 35-yard field goal. However, the 49ers' defense held on for the win. With the loss, the Bengals fell to 5-9, securing Head Coach Marvin Lewis' first losing season with Cincinnati. 
 Question: Which team lost to the Rams in the prior week?
Example Output: bengals

Example Input: Context: Young people frequently say that they want to exercise, but they just can't find the time. The solution just might be in-office interval training. Recent studies show that very short but intense exercise rapidly builds and maintains fitness and health, even when the workout is only a few minutes long. Work the stairs You can complete an excellent, effective -- and very brief -- workout in an office stairwell, says Martin Gibala, a professor of kinesiology at McMaster University in Canada and an expert on interval training. For a study that he and his colleagues presented earlier this year, they asked 12 out-of-shape women in their 20s to warm up for two minutes by slowly walking up and down stairs in a campus office building. They completed three of these abbreviated stair workouts per week for six weeks. By the end, their aerobic fitness had improved substantially, the researchers reported, by about as much as if they had been running or cycling each week for hours. Fidget your way to fitness. Parents and teachers may once have urged you to sit still, but wiggling, tapping your toes, standing briefly, and otherwise fidgeting as much as possible at your desk is in fact good for your body. In one recent study, college students showed healthier blood flow in their lower legs if they fidgeted than if they did not. Even better, a 2008 study found that among office workers, those who frequently fidgeted burned as many as 300 calories more each day than those who resolutely stayed still. 
 Question: How many studies are shown in the passage?
Example Output: three

Example Input: Context: The glycoprotein sclerostin (Scl; 22 kDa), which is involved in bone metabolism, may play a role in vascular calcification in haemodialysis (HD) patients. In the present study, we investigated the relation between serum Scl (sScl) and mortality. The effects of dialysis modality and the magnitude of the convection volume in haemodiafiltration (HDF) on sScl were also investigated. In a subset of patients from the CONTRAST study, a randomized controlled trial comparing HDF with HD, sScl was measured at baseline and at intervals of 6, 12, 24 and 36 months. Patients were divided into quartiles, according to their baseline sScl. The relation between time-varying sScl and mortality with a 4-year follow-up period was investigated using crude and adjusted Cox regression models. Linear mixed models were used for longitudinal measurements of sScl. The mean (standard deviation) age of 396 test subjects was 63.6 (13.9 years), 61.6% were male and the median follow-up was 2.9 years. Subjects with the highest sScl had a lower mortality risk than those with the lowest concentrations [adjusted hazard ratio 0.51 (95% confidence interval, CI, 0.31-0.86, P = 0.01)]. Stratified models showed a stable sScl in patients treated with HD ( +2.9 pmol/L/year, 95% CI -0.5 to +6.3, P = 0.09) and a decreasing concentration in those treated with HDF ( -4.5 pmol/L/year, 95% CI -8.0 to -0.9, P = 0.02). The relative change in the latter group was related to the magnitude of the convection volume. (i) A high sScl is associated with a lower mortality risk in patients with end-stage kidney disease; (ii) treatment with HDF causes sScl to fall; and (iii) the relative decline in patients treated with HDF is dependent on the magnitude of the convection volume. 
 Question: Sclerostin regulates what process?
Example Output:
bone metabolism