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.

[Q]: Context: Invasive species can have devastating effects on native ecosystems and therefore impose a significant threat to human welfare. The introduction rate of invasive species has accelerated dramatically in recent times due to human activity (anthropogenic effects), with a steadily growing pool of widespread tramp species. We present an in-depth analysis of four pantropical species of Xyleborus ambrosia beetles (Xyleborus volvulus, Xyleborus perforans, Xyleborus ferrugineus, and Xyleborus affinis) with similar ecology (fungus cultivation in dead wood), reproductive biology (permanent inbreeding) and genetic system (haplodiploidy). The unique combination of reproductive traits and broad host plant usage pre-adapts these beetles for colonizing of new areas.', 'We found that all four species were broadly distributed long before human-assisted dispersal became common, and that the impact of anthropogenic effects varied among the species. For X. volvulus, X. perforans, and X. affinis there was evidence of ancient establishment in numerous regions, but also of abundant recent introductions into previously colonized areas. For X. ferrugineus, we found clear biogeographical structuring of old clades, but little evidence for recent successful introductions.
Answer: Our results indicate that current human-aided transoceanic dispersal has strongly affected the genetic makeup of three of the species in this study. However, current biogeographical patterns of all four species are equally, if not more strongly, influenced by ancient establishment on different continents.
[A]: Do globally distributed Xyleborus species reveal recurrent intercontinental dispersal in a landscape of ancient worldwide distributions?

[Q]: Context: It has been hypothesized that minichromosome maintenance (MCM) proteins, which are replicative control factors, can be used to detect tumor proliferation. The aim of the present study was to investigate the expression of MCM in colorectal cancer tissues and correlate it to clinical outcomes.', 'The study included 145 patients with colorectal cancer who underwent curative surgery, from January 2002 until December 2004, at the Kurume University Hospital in Fukuoka, Japan. The median follow-up duration was 87 months. The expression of MCM7 in tissues was studied by immuno-histochemical staining. The labeling index (LI) of MCM7 was calculated by dividing the number of positively-stained cells by the total number of cells counted. We divided samples into two groups: positive (MCM7 LI 76% or higher) and negative (MCM7 LI less than 76%).', 'In patients with Dukes A and B, there were no significant differences in either overall survival (OS) or recurrence-free survival (RFS) between patents with MCM7-positive and those with MCM7-negative disease. On the other hand, in patients with Dukes C, there was significantly worse OS and RFS for patients with MCM7-positive compared to those with MCM7-negative disease.
Answer: We found that the expression of MCM7 is an independent risk factor for RFS in patients with Dukes C colorectal cancer. Further studies are required to investigate the validity of MCM7 protein expression for its potential clinical use in colorectal cancer therapy and prognosis.
[A]: Is minichromosome maintenance protein 7 a risk factor for recurrence in patients with Dukes C colorectal cancer?

[Q]: Context: The present study was designed to give possible answers to some of the discrepancies regarding the presence or not of intact fetal cells in maternal plasma during pregnancy.', '12-mL peripheral blood was collected from 33 pregnant women in the second trimester: 6 mL was harvested by 3-step Percoll gradient centrifugation and plasma cells were analyzed by FISH with X/Y chromosome specific probes. From the remaining 6 mL, plasma-derived cells were isolated with three different gradient centrifugation protocols and apoptosis was determined following EthBr staining.', 'The number of cells recovered ranged from 900 to 3000. At least one Y positive signal was seen in 12 out of 17 cases with male fetuses at a frequency of 0.12% (range 0.05-0.27%). No XY cells were detected in the plasma of women carrying female fetuses. Hybridization efficiency was <60%. EthBr staining demonstrated that the majority of these cells were in their late apoptosis.
Answer: Our findings confirm the presence of intact fetal apoptotic cells in maternal plasma; however, their late apoptotic state and the low number does not as yet encourage their use in clinical practice.
[A]:
Are fetal cells in maternal plasma found in a late state of apoptosis?