In this article, the MR findings of primary small bowel neoplasms are described and the MR findings for the differential diagnosis are discussed.”
“Describing large-scale patterns of biological diversity is a first step towards understanding the mechanisms that generate and maintain diversity.
The highly diverse deep-sea floor is the largest ecosystem on Earth, but the productivity-diversity relationship in this biome is not well characterized. We investigated this relationship by using biomass of nematodes as a proxy for productivity (particulate selleck compound organic carbon flux to the seabed). We used sample data collected from the New Zealand and Antarctic regions and combined these with published data from around the globe for broader analyses. There was a significant unimodal relationship between nematode biomass and diversity, i.e. expected number of species, ES(51) both within the New Zealand region and across ocean basins. This relationship remained significant after accounting for the effects of both water depth and nematode abundance. These findings support earlier suggestions of a unimodal productivity-diversity relationship in the deep sea that were based on other proxies (e. g. water depth, modelled particulate click here organic carbon flux). We argue that the ‘productivity context’ is of primary importance when determining the strength and nature of
the relationship between other environmental factors and diversity. Studies that include either or both extremes of the productivity scale are likely to find that productivity is the main factor limiting deep-sea diversity, whereas those focusing on the intermediate productivity range are more likely to find that other factors (e. g. disturbance, habitat heterogeneity) play a role.”
“A methodology to design and
optimise fibre metal laminates for improved fatigue and damage tolerance properties is presented. selleck chemical The lay-ups are defined in a systematic manner where the number and thickness of metal layers are varied and the lay-ups are divided into grades in which the amount and orientation of the fibre plies in the fibre layers are defined. The optimisation procedure is implemented with genetic algorithms and the lay-ups are designed such that the fatigue crack propagation or residual strength criteria is satisfied. The design criteria are evaluated using prediction methods and fitness approximations of these prediction methods. The latter evaluation aims to speed up the optimisation procedure. The functions of the fitness approximation are verified against the prediction methods and the design solutions of both evaluation methods are in compliance with each other. In conclusion, the procedure managed to find the optimal solutions within the design space while an improvement in computation time is achieved with the use of fitness approximation. (C) 2015 Elsevier Ltd. All rights reserved.