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.
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Question: 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.

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

Question: Context: Sit-to-stand tasks are commonly facilitated by modifying the initial position of the center of mass relative to the feet. It was hypothesized that modifications in the center of mass trajectory during sit-to-stand tasks altered the total body momentum at seat departure and redistributed the lower extremity net joint moments.', 'Between-task within-subject comparison was employed using a robust statistical method to accommodate for small sample size.', 'Six individuals performed four sit-to-stand tasks with systematic modifications in the initial center of mass position by varying the orientation of the lower extremity segments. The momentum of the center of mass and lower extremity net joint moments were quantified and compared.', 'Reducing the horizontal center of mass displacement significantly reduced horizontal total body momentum required at seat departure. Sit-to-stand tasks initiated with more horizontal shank and thigh positions required significantly greater knee and hip extensor net joint moments than those with more vertical shank and thigh positions. Sit-to-stand tasks initiated with vertical shank positions also required significantly greater hip extensor net joint moments as compared to those with more horizontal shank orientations.
Answer: When changes in initial center of mass position are made, alteration in center of mass horizontal momentum and the orientation of the lower extremity segments relative to the reaction force are observed. Consequently, mechanical demand imposed on the ankle, knee, and hip joint is redistributed. The magnitude of the net joint moments is dependent on the segment orientation, the reaction force, and the adjacent net joint moment.

Answer: Does modifying center of mass trajectory during sit-to-stand tasks redistribute the mechanical demand across the lower extremity joints?

Question: Context: Serum levels of matrix metalloproteinase-9 (MMP-9) which agree with progression in solid and haematological tumours were correlated to the risk of disease progression in 62 patients with early (Binet stage A) B-cell chronic lymphocytic leukaemia (CLL). Sera were taken at diagnosis and tested by an enzyme-linked immunosorbent assay.', 'MMP-9 levels positively correlated with haemoglobin levels (P = 0.03) and platelet count (P = 0.03). No association was found with main clinico-haematological features representative of tumour mass, such as peripheral blood lymphocytosis, bone marrow histology, Rai substages and beta-2 microglobulin (beta-2m). A cut-off of MMP-9 levels corresponding to 33rd percentile (203 ng/mL) or higher identified earlier upstaging and shorter progression-free survival. MMP-9 was a significant prognostic marker in multivariate analysis and partially independent of Rai substages, which suggests its inclusion into such a staging system to better stratify prognostically Rai stages I and II patients.
Answer: MMP-9 serum levels predict disease behaviour and help to refine the prognosis of stage A CLL patients.

Answer:
Do increased serum levels of matrix metalloproteinase-9 predict clinical outcome of patients with early B-cell chronic lymphocytic leukaemia?