35 research outputs found

    Phylogenomics and the rise of the angiosperms

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    Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5,6,7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade

    Survival after surgery or therapeutic catheterisation for congenital heart disease in children in the United Kingdom: analysis of the central cardiac audit database for 2000-1

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    Objectives To analyse simple national statistics and survival data collected in the central cardiac audit database after treatment for congenital heart disease and to provide long term comparative statistics for each contributing centre. Design Prospective, longitudinal, observational, national cohort survival study. Setting UK central cardiac audit database. Main outcome measures Survival at 30 days and one year after treatment in the year April 2000-March 2001, assessed by using both volunteered life status and independently validated life status through the Office for National Statistics, using the patient's unique NHS number, or the general register offices of Scotland and Northern Ireland. Institutional results following a group of six benchmark operations and three benchmark catheterisation procedures. Results Since April 2000 data have been received from all 13 UK tertiary centres performing cardiac surgery or therapeutic cardiac catheterisation in children with congenital heart disease. Altogether 3666 surgical procedures and 1828 therapeutic catheterisations were performed. Central tracking of mortality identified 469 deaths, 194 occurring within 30 days and 275 later. Forty two of the 194 deaths within 30 days were detected by central tracking but not by volunteered data. For surgery overall, survival at 30 days was 94.9%, falling to 91.2% at one year; this effect was most marked for infants. For therapeutic catheterisation survival at 30 days was 99.1%, falling to 98.1% at one year. Survival of individual centres or individual operators did not differ from the national average after benchmark procedures. Conclusions Independent data validation is essential for accurate survival analysis. One year survival gives a more realistic view of outcome than traditional perioperative mortality. Currently no detectable difference exists in survival between any of the 13 UK tertiary congenital heart disease centres, but confidence intervals for small centres are wide, limiting our power to detect underperformance from analysis of a single year's data. Appropriately resourced, focused national audit is capable of accurate data collection on which nationwide, long term quality control can be based

    Balloon valvuloplasty of the aortic valve in children: a surgical view

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