TASK DEFINITION: Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
PROBLEM: Context: Rapa Nui (Easter Island), located in the easternmost corner of the Polynesian Triangle, is one of the most isolated locations on the planet inhabited by humans. Archaeological and genetic evidence suggests that the island was first colonized by Polynesians around AD 1200, during their eastward expansion. Although it remains contentious whether Polynesians reached South America, suggestive evidence has been brought forward supporting the possibility of Native American contact prior to the European "discovery" of the island in AD 1722.', 'We generated genome-wide data for 27 Rapanui. We found a mostly Polynesian ancestry among Rapanui and detected genome-wide patterns consistent with Native American and European admixture. By considering the distribution of local ancestry tracts of eight unrelated Rapanui, we found statistical support for Native American admixture dating to AD 1280-1495 and European admixture dating to AD 1850-1895.
Answer: These genetic results can be explained by one or more pre-European trans-Pacific contacts.

SOLUTION: Do genome-wide ancestry patterns in Rapanui suggest pre-European admixture with Native Americans?

PROBLEM: Context: Besides chronic stress, chronic pain is a prevalent determinant for depression. Changes induced in specific brain regions by sustained pain may alter the processing of affective information, thus resulting in anxiodepressive disorders. Here, we compared the role of the anterior cingulate cortex (ACC) and the posterior insular cortex in the anxiodepressive, sensory, and affective aspects of chronic pain.', 'Neuropathic pain was induced by cuffing the right sciatic nerve of C57BL/6J mice. Lesions were performed by local injection of ibotenic acid and chronic activation of the ACC by optogenetic stimulation. Anxiodepressive-related behaviors were evaluated through the novelty suppressed feeding, marble burying, splash, and forced swimming tests. Mechanical thresholds were determined using von Frey filaments, and the relief of spontaneous pain was determined by using place conditioning.', 'The ACC lesion prevented the anxiodepressive consequences of chronic pain without affecting the sensory mechanical allodynia. Conversely, the tonic or spontaneous pain and the anxiodepressive consequences of pain remained present after posterior insular cortex lesion, even though the mechanical allodynia was suppressed. Furthermore, optogenetic stimulation of the ACC was sufficient to induce anxiety and depressive-like behaviors in naive animals.
Answer: Our results show that, at cortical level, the sensory component of chronic pain remains functionally segregated from its affective and anxiodepressive components. Spontaneous tonic pain and evoked allodynia can be experimentally dissociated. Furthermore, the ACC appears as a critical hub for mood disorders, including for the anxiodepressive consequences of chronic pain, and thus constitutes an important target for divulging the underlying mechanism.

SOLUTION: Is the anterior cingulate cortex a critical hub for pain-induced depression?

PROBLEM: Context: To determine the rate of persistent tracheocutaneous fistula (TCF) in pediatric patients managed with stomal maturation at the time of the tracheostomy.', 'Retrospective chart analysis of all cases of tracheostomy performed at a tertiary pediatric care center between 2001 and 2011.', 'The use of stomal maturation, number of decannulations, number of persistent TCFs, timing of TCF repair, and the overall mortality were assessed.', 'A total of 264 patients received tracheostomy between 2001 and 2011. Of the total, 173 (66%) underwent stomal maturation. Of those 173 patients, 89 patients (51% of maturation group) underwent planned decannulation. Forty seven (53%) of the 89 decannulated were found to have a persistent TCF in the stomal maturation group. These were diagnosed an average of 1.3 years (range, 4-43 months) after decannulation. Of the 91 patients (34% of the total) who did not undergo stomal maturation, 44 (48% of nonmaturation group) underwent planned decannulation. Twenty of the 44 patients decannulated (45%) were diagnosed with a residual TCF 8 to 28 months later. Both groups achieved similar rates of decannulation (51% maturation vs. 48% non-maturation [P=.80]) and TCF (27% maturation vs. 22% non-maturation [P=.44]). Overall, mortality rates were (32/173) 18% (matured) versus (26/91) 29% (nonmatured). No mortalities were tracheostomy related. The mean (standard deviation) time from operation to TCF closure among those with TCF was 4.0 (1.9) years.
Answer: Comparable rates of persistent TCF with stomal maturation (27%) and without maturation (22%) were found in this single institution's 10-year experience.

SOLUTION:
Does stomal maturation increase the rate of tracheocutaneous fistulas?