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.

[EX 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.
[EX A]: Do globally distributed Xyleborus species reveal recurrent intercontinental dispersal in a landscape of ancient worldwide distributions?

[EX Q]: Context: Progenitor cells isolated from cardiac explant-derived cells improve cardiac function after myocardial infarction (MI). To fully realize the therapeutic potential of these cells, it is essential to develop a safe and efficient delivery method. Therefore, the objective of this study was to determine the efficacy of our newly developed approach to retrograde coronary vein (RCV) infusion of cardiac c-Kit(+) cells in a small-animal model of congestive heart failure (CHF).', 'Sprague-Dawley rats underwent experimental MI. After 21 days, cardiac explant-derived c-Kit(+) cells were delivered to both sham and CHF animals using RCV delivery. Vehicle-treated (serum-free medium) sham and CHF animals were used as controls. Cardiac function and heart tissues were evaluated 21 days post-transplantation.', 'RCV-delivered cells were retained in infarcted hearts for at least 21 days after transplantation. At 21 days post-RCV infusion, the majority of transplanted c-Kit(+)/GFP(+) cells were localized in the left ventricle. Compared with vehicle-treated CHF animals, RCV-treated rats showed a significant improvement in cardiac function. Furthermore, RCV-treated rats exhibited an increase in capillary density, a decrease in total heart collagen, and a reduction in both infarct size and cardiomyocyte hypertrophy when compared with vehicle-treated CHF rats.
Answer: Our study showed that the RCV infusion approach is an efficient technique for targeted cell delivery to the infarcted myocardium. Cardiac c-Kit(+) cells, delivered using RCV infusion ameliorated progression of heart failure, improved cardiac function and retarded myocardial remodeling in heart failure rats.
[EX A]: Does retrograde coronary vein infusion of cardiac explant-derived c-Kit+ cells improves function in ischemic heart failure?

[EX Q]: Context: The modifiable variable best proven to improve survival after resection of pancreatic adenocarcinoma is the addition of adjuvant chemotherapy. A theoretical advantage of minimally invasive pancreaticoduodenectomy (MI-PD) is the potential for greater use and earlier initiation of adjuvant therapy, but this benefit remains unproven.', 'The 2010-2012 National Cancer Data Base (NCDB) was queried for patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma. Subjects were classified as MI-PD versus open pancreaticoduodenectomy (O-PD). Baseline variables were compared between groups. The independent effect of surgical approach on the use and timing of adjuvant chemotherapy was estimated using multivariable regression analyses.', 'For this study, 7967 subjects were identified: 1191 MI-PD (14.9%) and 6776 O-PD (85.1%) patients. Patients who underwent MI-PD were more likely to have been treated at academic hospitals. Otherwise, the groups had no baseline differences. In both the MI-PD and O-PD groups, approximately 50% of the patients received adjuvant chemotherapy, initiated at a median of 54 versus 55 days postoperatively (p = 0.08). After multivariable adjustment, surgical approach was not independently associated with use (odds ratio 1.00; p = 0.99) or time to initiation of adjuvant chemotherapy (-2.3 days; p = 0.07). Younger age, insured status, lower comorbidity score, higher tumor stage, and the presence of lymph node metastases were independently associated with the use of adjuvant chemotherapy.
Answer: At a national level, MI-PD does not result in greater use or earlier initiation of adjuvant chemotherapy. As surgeons and institutions continue to gain experience with this complex procedure, it will be important to revisit this benchmark as a justification for its increasing use for patients with pancreatic cancer.
[EX A]:
Does minimally Invasive Pancreaticoduodenectomy Improve Use or Time to Initiation of Adjuvant Chemotherapy for Patients With Pancreatic Adenocarcinoma?