Normalizations with exponentially small remainders for nonautonomous analytic periodic vector fields

In this paper we deal with analytic nonautonomous vector fields with a periodic time-dependancy, that we study near an equilibrium point. In a first part, we assume that the linearized system is split in two invariant subspaces E0 and E1. Under light diophantine conditions on the eigenvalues of the linear part, we prove that there is a polynomial change of coordinates in E1 allowing to eliminate up to a finite polynomial order all terms depending only on the coordinate u0 of E0 in the E1 component of the vector field. We moreover show that, optimizing the choice of the degree of the polynomial change of coordinates, we get an exponentially small remainder. In the second part, we prove a normal form theorem with exponentially small remainder. Similar theorems have been proved before in the autonomous case : this paper generalizes those results to the nonautonomous periodic case

Static Analysis of Aspect Interaction and Composition in Component Models

International audienceComponent based software engineering and aspect orientation are claimed to be two complementary approaches. While the former ensures the modularity and the reusability of software entities, the latter enables the modularity of crosscutting concerns that cannot be modularized by regular components. Nowadays, several approaches and frameworks are dedicated to integrate aspects into component models. However, when several aspects are woven, interferences may appear which results on undesirable behaviors. The contribution of this paper is twofold. First, we show how aspectualized component models can be formally modeled in Uppaal model checker in order to detect potential interferences among aspects. Second, we provide an extendible catalog of composition operators used for aspect composition. We illustrate our general approach with an airport Internet service example

Biogeochemical modelling of anaerobic vs. aerobic methane oxidation in a meromictic crater lake (Lake Pavin, France)

International audienceMethane is a powerful greenhouse gas and its concentration in the atmosphere has increased over the past decades. Methane produced by methanogenic Archae can be consumed through aerobic and anaerobic oxidation pathways. In anoxic conditions found in freshwater environments such as meromictic lakes, CH4 oxidation pathways involving different terminal electron acceptors such as NO 3 , SO2 4 , and oxides of Fe and Mn are thermodynamically possible. In this study, a reactive transport model was developed to assess the relative significance of the different pathways of CH4 consumption in the water column of Lake Pavin. In most cases, the model reproduced experimental data collected from the field from June 2006 to June 2007. Although the model and the field measurements suggest that anaerobic CH4 oxidation may contribute to CH4 consumption in the water column of Lake Pavin, aerobic oxidation remains the major sink of CH4 in this lake

From Research to Operational Biomonitoring of Freshwaters: A Suggested Conceptual Framework and Practical Solutions

International audienceThe contradictory demands of managers (quick relevant operational responses) and ecologists (need time for in-depth research) involved in freshwater biomonitoring are still relevant today. To contribute to solving this dilemma, we are proposing a novel biomonitoring approach, which among many others, could be used in this field and further developed in the future. Biomonitoring actions are integrated in conceptual schemes, in which hydrology, chemistry, hydrogeology and geomorphology bear as much importance as biology. Among biomonitoring tools, a harmonization system allows end-users to use a set of qualitative indicators (various biotic indices) and integrate the information given by individual biotic indices. Functional traits and calculation of an ecological potential in porous aquatic habitats (surficial coarse sediments and the hyporheic system) are regarded as a basis for assessing ecological functioning of streams and rivers. This last methodology takes into account the dynamics of water exchanges between surface water and groundwater. Objectives of ecological quality, ecological potentials and resilience capacity that need to be preserved or rehabilitated in aquatic habitats are established. In lakes, a similar approach was followed and a general typology of lake functioning was proposed, including that for urban lakes. All those biomonitoring tools are transferred to end-users and subject to further research. The final purpose is to promote practical high-tech tools which are continually and interactively connected with ongoing research

Separatrix splitting at a Hamiltonian 02iω0^2 i\omega bifurcation

We discuss the splitting of a separatrix in a generic unfolding of a degenerate equilibrium in a Hamiltonian system with two degrees of freedom. We assume that the unperturbed fixed point has two purely imaginary eigenvalues and a double zero one. It is well known that an one-parametric unfolding of the corresponding Hamiltonian can be described by an integrable normal form. The normal form has a normally elliptic invariant manifold of dimension two. On this manifold, the truncated normal form has a separatrix loop. This loop shrinks to a point when the unfolding parameter vanishes. Unlike the normal form, in the original system the stable and unstable trajectories of the equilibrium do not coincide in general. The splitting of this loop is exponentially small compared to the small parameter. This phenomenon implies non-existence of single-round homoclinic orbits and divergence of series in the normal form theory. We derive an asymptotic expression for the separatrix splitting. We also discuss relations with behaviour of analytic continuation of the system in a complex neighbourhood of the equilibrium

Iron, silicate, and light co-limitation of three Southern Ocean diatom species

The effect of combined iron, silicate, and light co-limitation was investigated in the three diatom species Actinocyclus sp. Ehrenberg, Chaetoceros dichaeta Ehrenberg, and Chaetoceros debilis Cleve, isolated from the Southern Ocean (SO). Growth of all species was co-limited by iron and silicate, reflected in a significant increase in the number of cell divisions compared to the control. Lowest relative Si uptake and drastic frustule malformation was found under iron and silicate co-limitation in C. dichaeta, while Si limitation in general caused cell elongation in both Chaetoceros species. Higher light intensities similar to SO surface conditions showed a negative impact on growth of C. dichaeta and Actinocyclus sp. and no effect on C. debilis. This is in contrast to the assumed light limitation of SO diatoms due to deep wind driven mixing. Our results suggest that growth and species composition of Southern Ocean diatoms is influenced by a sensitive interaction of the abiotic factors, iron, silicate, and light

Contract Aware Components, 10 years after

The notion of contract aware components has been published roughly ten years ago and is now becoming mainstream in several fields where the usage of software components is seen as critical. The goal of this paper is to survey domains such as Embedded Systems or Service Oriented Architecture where the notion of contract aware components has been influential. For each of these domains we briefly describe what has been done with this idea and we discuss the remaining challenges.Comment: In Proceedings WCSI 2010, arXiv:1010.233

ATLAS Data Transfer Functional Test (October 2006)

Data transfer function test was conducted in October 2006. DDM software components were used to transmit, control and monitor data movement. The main purpose of the test was to check system functionality during data transfer from CERN ATLAS centers. The issue of large files transfer is also have been tested

Identification of potential prognostic biomarkers for node-negative breast tumours by proteomic analysis: a multicentric 2004 national PHRC study

We used a 2D-electrophoresis (2-DE) proteomic approach to identify novel biomarkers in node-negative breast cancers. This retrospective study focused on a population of patients with ductal pN0M0 tumours. A subset of patients who developed metastases and in whose tumours were found high levels of uPA and PAI-1 (metastatic relapse, MR: n=20) were compared to another subset in whom no metastatic relapse occurred and whose tumours were found to have low levels of uPA and PAI-1 (no relapse, NR: n=21). We used a 2-DE coupled with MS approach to screen cytosol fractions using two pH-gradient scales, a broad scale (3.0-11.0) and a narrower scale focussing in on a protein rich region (5.0-8.0). This study was conducted on 41 cytosol specimens analyzed in duplicate on two platforms. The differential analysis of more than 2,000 spots in 2-DE gels, obtained on the two platforms, allowed the identification of 13 proteins which were confirmed by western blotting. Two proteins, GPDA and FABP4 were down-regulated in the MR subset whereas all the others were up-regulated. An in silico analysis revealed that GMPS (GUAA), GAPDH (G3P), CFL1 (COF1) and FTL (FRIL), the most informative genes, displayed a proliferation profile (high expression in basal-like, HER2+ and luminal B molecular subtypes). Inversely, similar to FABP4, GPD1 [GPDA] displayed a high expression in luminal A subtype, a profile characteristic of tumour suppressor genes. Despite the small size of our cohort, the 2-DE analysis gave interesting results which were confirmed by the in silico analysis showing that some of the corresponding genes had a strong prognostic impact in breast cancer, mostly because of their link with proliferation: GMPS, GAPDH, FTL and GPD1. A validation phase on a larger cohort is now needed before these biomarkers could be considered for use in clinical practice

Metadata for ATLAS

This document provides an overview of the metadata, which are needed to characterize ATLAS event data at different levels (a complete run, data streams within a run, luminosity blocks within a run, individual events)