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: Poultry remains a major source of foodborne bacterial infections. A variety of additives with presumed anti-microbial and/or growth-promoting effects are commonly added to poultry feed during commercial grow-out, yet the effects of these additives on the gastrointestinal microbial community (the GI microbiome) as the bird matures remain largely unknown. Here we compared temporal changes in the cecal microbiome to the effects of formic acid, propionic acid, and medium-chain fatty acids (MCFA) added to feed and/or drinking water.', 'Cecal bacterial communities at day of hatch (n=5 birds), 7d (n=32), 21d (n=27), and 42d (n=36) post-hatch were surveyed using direct 454 sequencing of 16S rRNA gene amplicons from each bird in combination with cultivation-based recovery of a Salmonella Typhimurium marker strain and quantitative-PCR targeting Clostridium perfringens. Treatment effects on specific pathogens were generally non-significant. S. Typhimurium introduced by oral gavage at day of hatch was recovered by cultivation from nearly all birds sampled across treatments at 7d and 21d, but by 42d, S. Typhimurium was only recovered from ca. 25% of birds, regardless of treatment. Sequencing data also revealed non-significant treatment effects on genera containing known pathogens and on the cecal microbiome as a whole. In contrast, temporal changes in the cecal microbiome were dramatic, highly significant, and consistent across treatments. At 7d, the cecal community was dominated by three genera (Flavonifractor, Pseudoflavonifractor, and a Lachnospiracea sequence type) that accounted for more than half of sequences. By 21d post-hatch, a single genus (Faecalibacterium) accounted for 23-55% of sequences, and the number of Clostridium 16S rRNA gene copies detected by quantitative-PCR reached a maximum.\Question: Are successional changes in the chicken cecal microbiome during 42 days of growth independent of organic acid feed additives?

A: Over the 42 d experiment, the cecal bacterial community changed significantly as measured by a variety of ecological metrics and increases in the complexity of co-occurrence networks. Management of poultry to improve animal health, nutrition, or food safety may need to consider the interactive effects of any treatments with the dramatic temporal shifts in the taxonomic composition of the cecal microbiome as described here.
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Q: Context: Although uncommon, hearing loss after spinal anesthesia has been described. Vestibulocochlear dysfunction after spinal anesthesia in which 22-gauge and 25-gauge Quincke needles were used was investigated to determine if needle size affected hearing.', 'Patients with American Society of Anesthesiologists physical status I and II, aged 20 to 40 years, who were undergoing lower extremity surgery under spinal anesthesia were randomized into 2 groups. After intravenous hydration, 3 mL of 0.5% bupivacaine was administered for spinal anesthesia, which was performed with a 22-gauge Quincke needle in group I (n=30) patients and a 25-gauge Quincke needle in group II (n=30) patients. Before surgery and 2 days after surgery, pure-tone audiometry and tympanometry were performed. Preoperative and postoperative hearing data were obtained in the right and left ears for every frequency. Headache, nausea, and vomiting and cranial nerve III, IV, V, VI, VII, and VIII function were assessed on postoperative day 2.', 'Demographic data were not different between the groups. No hypoacousis was noted at any frequency during the entire testing period in either group. Two patients from group I experienced postdural puncture headache on postoperative day 3, and neither had hearing loss. No patient had cranial nerve dysfunction.\Question: Does hearing loss occur in young patients undergoing spinal anesthesia?

A: We were unable to induce hearing loss in young patients undergoing spinal anesthesia by injecting the anesthetic with a 22-gauge or a 25-gauge Quincke needle.
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Q: Context: To investigate the potential of specific angiotensin II subtype 1 (AT1) receptor blockade to modify the mesenteric hemodynamic response to acute hypovolemia and retransfusion.', 'Prospective, randomized, controlled experimental study.', 'University-affiliated animal research laboratory.', 'Fasted, anesthetized, ventilated, juvenile domestic pigs of both sexes.', 'Acute, graded hypovolemia by 20% and 40% of the total estimated blood volume followed by retransfusion in control animals (CTRL; n = 10) and animals pretreated with the AT1 receptor blocker candesartan (CAND; n = 10).', 'Invasive monitoring of arterial and central venous blood pressures, cardiac output, portal venous blood flow, and jejunal mucosal blood flow. Blood gases were repeatedly analyzed to calculate oxygen delivery and consumption. Thirty minutes after each level of hypovolemia at 20% and 40%, cardiac output was decreased in CTRL animals from a baseline of 2.9 +/- 0.1 to 1.8 +/- 0.2 and 1.1 +/- 0.2 L/min, with no differences compared with CAND animals. Cardiac output was restored to 3.0 +/- 0.3 L/min 30 mins after retransfusion in CTRL animals, with no significant intergroup differences. Baseline portal venous blood flow (Q(MES)) and jejunal mucosal perfusion (PU(JEJ)) were greater in CAND animals compared with CTRL animals. During graded hypovolemia, CAND animals maintained Q(MES) and PU(JEJ) at significantly higher levels compared with CTRL animals, particularly after 40% hemorrhage (+221% and + 244%, respectively, relative to the mean values in CTRL animals). The same pattern was observed after retransfusion. Moreover, the calculated mesenteric critical oxygen delivery was significantly greater in CTRL animals (74 mL/min) compared with CAND animals (34 mL/min). No animals died in the CAND group, whereas four animals died during 40% hypovolemia or retransfusion in the CTRL group.\Question: Does specific angiotensin II receptor blockage improve intestinal perfusion during graded hypovolemia in pigs?

A:
Specific AT1 blockade before acute hypovolemia significantly ameliorated mesenteric and, in particular, jejunal mucosal hypoperfusion. In addition, cardiovascular stability was improved, and mortality in conjunction with acute hypovolemia and retransfusion could be completely avoided. These findings support a fundamental role of the renin-angiotensin system in the mesenteric response to acute hypovolemia and indicate a substantial interventional potential for candesartan in conjunction with circulatory stress.
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