Differential impact of drugs on the outcome of ETV6-RUNX1 positive childhood B-cell precursor acute lymphoblastic leukaemia : results of the EORTC CLG 58881 and 58951 trials

info:eu-repo/semantics/publishe

Finding Optimal Routes for Harvesting Tree Access

The layout of forest roads to access cut trees is often done manually in tropical forests, yielding suboptimal road networks with respect to the building cost. An alternative consists in using numerical optimization techniques to find a solution to this problem, also known as the multiple target access problem (MTAP). We used six numerical methods, three of which were found in the literature, to solve the MTAP. The six methods were compared on the basis on the building cost of the road network that they create, and on the basis of the computing time. They were used to solve randomly generated MTAP and also to solve a real case-study in an Indonesian rain-forest at Bulungan. The method that yielded the lowest building cost also required the longest computing time. Its computing time is actually so long that this method cannot be used in real situations. The fastest method poorly minimized the building cost. Among the four remaining methods, two methods were faster than the two others (by a factor 1.5 and 2). One of these two faster methods also yielded the lowest building costs among the four remaining method

Finding Optimal Routes for Harvesting Tree Access

The layout of forest roads to access cut trees is often done manually in tropical forests, yielding suboptimal road networks with respect to the building cost. An alternative consists in using numerical optimization techniques to find a solution to this problem, also known as the multiple target access problem (MTAP). We used six numerical methods, three of which were found in the literature, to solve the MTAP. The six methods were compared on the basis on the building cost of the road network that they create, and on the basis of the computing time. They were used to solve randomly generated MTAP and also to solve a real case-study in an Indonesian rain-forest at Bulungan. The method that yielded the lowest building cost also required the longest computing time. Its computing time is actually so long that this method cannot be used in real situations. The fastest method poorly minimized the building cost. Among the four remaining methods, two methods were faster than the two others (by a factor 1.5 and 2). One of these two faster methods also yielded the lowest building costs among the four remaining method

The impact of climate changes during the Holocene on vegetation in northern French Guiana

The impact of climatic changes that occurred during the last glacial maximum and the Holocene on vegetation changes in the Amazon Basin and the Guiana Shield are still widely debated. The aim of our study was to investigate whether major changes in vegetation (i.e. transitions between rainforests and C4 savannas) occurred in northern French Guiana during the Holocene. We measured variations in the d13C of soil organic matter at eight sites now occupied by forest or savannah. The forest sites were selected to cover two regions (forest refugia and peneplains) which are thought to have experienced different intensities of disturbance during the latest Pleistocene and the Holocene. We found that none of the forest sites underwent major disturbances during the Holocene, i.e. they were not replaced by C4 savannahs or C4 forest savannahs for long periods. Our results thus suggest that tropical rainforests in northern French Guiana were resilient to drier climatic conditions during the Holocene. Nevertheless, geographical and vertical variations in the 13C of SOM were compatible with minor changes in vegetation, variations in soil processes or in soil physical properties

Geomorphic control of rain-forest floristic composition in French Guiana : more than a soil filtering effect ?

The influence of geomorphological features on rain-forest diversity has been reported in different Amazonian regions. Soil filtering is often assumed to underlie the observed geomorphic control on the floristic composition but other hypotheses related to biogeography or long-term forest dynamics are also possible. We tested relationships between geomorphology, soil properties and forest composition in French Guiana rain forest using a recent geomorphological map and a large dataset comprising 3132 0.2-ha plots and 421 soil cores. Soil properties were characterized by laboratory analyses and by field descriptions indicating drainage capacity and classification according to the World Reference Base (WRB). The influence of soils and geomorphology on beta-diversity was tested using variance partitioning and ANOVA-like tests. Our results confirm the hypothesis of a strong relationship between geomorphological landscapes and soil properties. Soil filtering significantly influenced the abundance of more than 40 species or groups of species. However geomorphic control of forest composition involves much more than the effects of the soil, which only explain a minor part of the broad-scale patterns of forest diversity related to geomorphological landscapes. These results reinforce the alternative hypotheses linking geomorphological landscapes to long-term forest change under the control of historical processes that shaped forest diversity