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.

Q: Context: Urinary dysfunction (UD) is common after rectal cancer treatment, but the contribution of each treatment component (surgery and radiotherapy) to its development remains unclear. This study aimed to evaluate UD during 5 years after total mesorectal excision (TME) and to investigate the influence of preoperative radiotherapy (PRT) and surgical factors.', 'Patients with operable rectal cancer were randomized to TME with or without PRT. Questionnaires concerning UD were completed by 785 patients before and at several time points after surgery. Possible risk factors, including PRT, demographics, tumour location, and type and extent of resection, were investigated by multivariable regression analysis.', 'Long-term incontinence was reported by 38.1 per cent of patients, of whom 72.0 per cent had normal preoperative function. Preoperative incontinence (relative risk (RR) 2.75, P = 0.001) and female sex (RR 2.77, P < 0.001) were independent risk factors. Long-term difficulty in bladder emptying was reported by 30.6 per cent of patients, of whom 65.0 per cent had normal preoperative function. Preoperative difficulty in bladder emptying (RR 2.94, P < 0.001), peroperative blood loss (RR 1.73, P = 0.028) and autonomic nerve damage (RR 2.82, P = 0.024) were independent risk factors. PRT was not associated with UD.\Question: Is urinary dysfunction after rectal cancer treatment mainly caused by surgery?

A: UD is a significant clinical problem after rectal cancer treatment and is not related to PRT, but rather to surgical nerve damage.
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Q: Context: Perls' stain is routinely used to demonstrate iron in liver biopsies. We tested the hypothesis that it may be unnecessary in cases, where no iron or another similar pigment was seen on the routine hematoxylin and eosin (H and E) stained section.", "The aim of this study was to evaluate the efficiency of H and E stain in demonstrating iron in liver biopsies as well as to determine the possibility of replacing Perls' stain with H and E stain.", "Two hundred pairs of slides of liver biopsies were taken from the archival files of the Department of Pathology from 2006 to 2011. Perls' and H and E slides were independently reviewed for the presence of iron.", "Hundred and one cases showed the presence of iron using H and E stain. 84 of 86 cases showed positive iron using both Perls' and H and E stains. Seventeen cases were positive using H and E stain but negative with Perls'. Only two cases did not show the presence of iron using H and E stain. Ninety-seven cases were negative using both Perls' and H and E stains. H and E stain showed a sensitivity, specificity, accuracy, positive predictive valve, and negative predictive value of 97.67%, 85.08%, 90.5%, 83.16%, and 97.98%, respectively.\Question: Do hematoxylin and eosin stain shows a high sensitivity but sub-optimal specificity in demonstrating iron pigment in liver biopsies?

A: We demonstrate that the H and E stain is a sensitive method to detect iron pigment in liver biopsies, particularly when present in large quantities. A negative H and E stain might obviate the need for extra Perls' staining, thus saving costs and shortening report turn-around times.
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Q: Context: Larger food portions lead to increased intake but the mechanism behind this effect is unclear. We investigated the effect of portion size on bite size, eating rate, deceleration rate, and meal duration.', 'Thirty-seven overweight women attended 5 visits after a 3 h fast and consumed a 229, 303, 400, 529 or 700 g portion of a lunch meal in random order. Meal eating parameters were measured with the Sussex Ingestion Pattern Monitor. Data were analyzed with mixed effects models.', 'Average bite size increased by 0.22 g for every 100 g increase in portion size (p=0.001); portion size had a non-linear effect on eating rate, increasing with portion sizes up to about 540 g (p=0.01). Deceleration rate (reduction in speed of eating) decreased by 20% (p<0.001) and meal duration increased by 22.5% for every 100 g increase in portion size (p<0.001), relative to the smallest portion.\Question: Do large portion sizes increase bite size and eating rate in overweight women?

A:
Increasing portion size led to a larger bite size and faster eating rate, but a slower reduction in eating speed during the meal. These changes may underlie greater energy intakes with exposure to large portions. Interventions to reduce bite size and slow eating rate may provide individuals with strategies to reduce the risk of overconsumption.
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