HP-CERTI: Towards a high performance, high availability open source RTI for composable simulations (04F-SIW-014)

Composing simulations of complex systems from already existing simulation components remains a challenging issue. Motivations for composable simulation include generation of a given federation driven by operational requirements provided "on the fly". The High Level Architecture, initially developed for designing fully distributed simulations, can be considered as an interoperability standard for composing simulations from existing components. Requirements for constructing such complex simulations are quite different from those discussed for distributed simulations. Although interoperability and reusability remain essential, both high performance and availability have also to be considered to fulfill the requirements of the end user. ONERA is currently designing a High Performance / High Availability HLA Run-time Infrastructure from its open source implementation of HLA 1.3 specifications. HP-CERTI is a software package including two main components: the first one, SHM-CERTI, provides an optimized version of CERTI based on a shared memory communication scheme; the second one, Kerrighed-CERTI, allows the deployment of CERTI through the control of the Kerrighed Single System Image operating system for clusters, currently designed by IRISA. This paper describes the design of both high performance and availability Runtime Infrastructures, focusing on the architecture of SHM-CERTI. This work is carried out in the context of the COCA (High Performance Distributed Simulation and Models Reuse) Project, sponsored by the DGA/STTC (Délégation Générale pour l'Armement/Service des Stratégies Techniques et des Technologies Communes) of the French Ministry of Defense

Genetic algorithms for automatic regroupment of Air Traffic Control sectors

http://dl.acm.org/citation.cfm?id=546164International audienceIn this paper, we show how genetic algorithms can be used to compute automatically a balanced regroupement of Air Traffic Control sectors to optimally reduce the number of controller teams during daily low flow periods

Finite Element Simulation of Multi Material Metal Forming

International audienceThe basic formulation for finite element modeling of metal forming processes is briefly recalled with the aim of treating the case of multi body interactions. This situation occurs when the tools are considered as deformable, when the work-piece includes several materials or when the physical structure is analyzed at the micro scale. The classical approach utilizes separate meshes for each body and the contact is enforced using different numerical methods: the complete coupling, the master and slave approach and a quasi-symmetrical formulation. The single mesh method with different constitutive equations corresponding to each material is more computationally effective, but its use is restricted to the cases when the contact between the different bodies does not evolve. Finally the Euler formulation can be used with a level set method for the description of the interfaces between different materials and its application to recrystallization for example

3D-LIVE : live interactions through 3D visual environments

This paper explores Future Internet (FI) 3D-Media technologies and Internet of Things (IoT) in real and virtual environments in order to sense and experiment Real-Time interaction within live situations. The combination of FI testbeds and Living Labs (LL) would enable both researchers and users to explore capacities to enter the 3D Tele-Immersive (TI) application market and to establish new requirements for FI technology and infrastructure. It is expected that combining both FI technology pull and TI market pull would promote and accelerate the creation and adoption, by user communities such as sport practitioners, of innovative TI Services within sport events

Selective changes in GABAA receptor subtypes in white matter neurons of patients with focal epilepsy

Mapping the distribution of GABAA receptor subtypes represents a promising approach to characterize alterations in cortical circuitry associated with neurological disorders. We previously reported subtype-selective changes in GABAA receptor expression in the grey matter of patients with focal epilepsy. In the present follow-up study, we focused on the subcortical white matter in the same tissue specimens obtained at surgery from 9 patients with temporal lobe epilepsy (TLE) and hippocampal sclerosis, 12 patients with TLE associated with neocortical lesions and 5 patients with frontal lobe epilepsy; post-mortem tissue from 4 subjects served as controls. The subunit composition and distribution of three major GABAA receptor subtypes were determined immunohistochemically with subunit-specific antibodies. In all cases, a majority of neurons in the white matter was distinctly labelled, allowing detailed visualization of their dendritic arborization and revealing a differential, cell type-specific expression pattern of α-subunit variants. In controls, α1-subunit staining was most prominent, displaying a gradient that decreased with depth, in parallel with the density of NeuN-positive cells. Subsets of pyramidal cells were α3-subunit-positive, and α2-subunit-labelled neurons were rare. In 19 of the 26 patients with focal epilepsy, no changes were detected as compared with controls. In five patients with TLE, striking changes in the dendritic arborization of a subset of white matter neurons were seen with the α1-subunit antibody. In two further patients with TLE, we observed a disorganized dendritic network immuno-positive for the α1-subunit, cell clusters selectively expressing the α2-subunit and small neuronal aggregates that expressed all subunits and appeared to connect to neighbouring white matter neurons. All seven patients with anomalies in the white matter had a selective reduction in α3-containing GABAA receptors in the superficial layers of the grey matter. These results demonstrate a distinct organization of GABAA receptors in human white matter neurons, consistent with an inhibitory network that is likely to be integrated functionally with the overlying grey matter. The altered dendritic morphology and changes in GABAA receptor expression in the white matter of a subset of patients with focal epilepsy are suggestive for a rewiring of neuronal circuit

How to determine the parameters of polymer crystallization for modeling the injection-molding process?

International audienceTo understand the relationship between 'polymers-processing conditions-structures-properties', crystallization is one of the major concerned phenomena. A general crystallization model derived from Avrami's work has been developed at CEMEF and implemented into a 3D finite element code for injection-molding named Rem3D®. It gives a precise description of the crystallization event, allows the determination of morphological features, but it requires a reliable determination of the crystallization parameters. The experimental procedures adopted to capture relevant experimental parameters are presented. The determination of overall kinetics, density of potential nuclei with activation frequency of nuclei into crystalline entities, and growth rate is carried out with polarized optical microscopy (POM) and is supplemented by small angle light scattering (SALS). The treatment of data is performed by a classical method or using an inverse genetic algorithm method to extract the parameters necessary to our model. The 2D simulation of the crystallization, illustrated with Rem3D®, reproduces the experimental reality quite accurately, in the case of an isothermal and static crystallization. This is applied to two polymers, an isotactic homopolymer polypropylene iPP and a polyether-block amide PEBAX®

Thermodynamics and Thermokinetics to Model Phase Transitions of Polymers over Extended Temperature and Pressure Ranges Under Various Hydrostatic Fluids

We are grateful to InTech the publisher of the book "Thermodynamics - Interaction Studies - Solids, Liquids and Gases", for letting this publication being archived in this Open Access repository. The publication is available from Intech Open Access Publisher: http://www.intechopen.com/articles/show/title/thermodynamics-and-thermokinetics-to-model-phase-transitions-of-polymers-over-extended-temperature-aInternational audienceA scientific understanding of the behaviour of polymers under extreme conditions of temperature and pressure becomes inevitably of the utmost importance when the objective is to produce materials with well-defined final in-use properties and to prevent the damage of materials during on-duty conditions. The proper properties as well as the observed damages are related to the phase transitions together with intimate pattern organization of the materials. Thermodynamic and thermokinetic issues directly result from the thermodynamic independent variables as temperature, pressure and volume that can stay constant or be scanned as a function of time. Concomitantly, these variables can be coupled with a mechanical stress, the diffusion of a solvent, and/or a chemically reactive environment. A mechanical stress can be illustrated in a chemically inert environment by an elongation and/or a shear. Diffusion is typically described by the sorption of a solvent. A chemical environment is illustrated by the presence of a reactive environment as carbon dioxide or hydrogen for example. Challenging aspects are polymer pattern multi scale organizations, from the nanometric to the macrometric scale, and their importance regarding industrial and technological problems, as described in the state of the art in Part 2. New horizons and opportunities are at hands through pertinent approaches, including advanced ad hoc experimental techniques with improved modelling and simulation. Four striking illustrations, from the interactions between a solvent and a polymer to the growth patterns, are illustrated in Part 3

Altered expression of α3-containing GABAA receptors in the neocortex of patients with focal epilepsy

Impaired transmission in GABAergic circuits is thought to contribute to the pathogenesis of epilepsy. Although it is well established that major reorganization of GABAA receptor subtypes occurs in the hippocampus of patients with medically refractory temporal lobe epilepsy (TLE), it is unclear whether this disorder is also associated with alterations in GABAA receptor subtypes in the neocortex. Here we have investigated immunohistochemically the subunit composition and neocortical distribution of three major GABAA receptor subtypes using antibodies specifically recognizing the subunits α1, α2, α3, β2/3 and γ2. Cortical tissue was obtained at surgery from patients with TLE and hippocampal sclerosis (HS; n = 9), TLE associated with neocortical lesions (non-HS; n = 12) and frontal lobe epilepsy (FLE; n = 5), with post-mortem samples serving as controls (n = 4). A distinct laminar and neuronal expression pattern of the α-subunit variants was found across the neocortical regions examined in the temporal and frontal lobes in both control and patient tissue samples. In the five patients with FLE, GABAA receptor subunit staining was unchanged as compared to controls. In patients with TLE we observed a marked decrease in α3-subunit staining in the superficial neocortical layers (I-III), but no change in the deep layers (V and VI) or in the expression pattern of the α1 and α2-subunits. Reduced expression in α3-containing GABAA receptors was detected in six out of nine patients of the HS group and four out of twelve patients of the non-HS group. Histopathological changes were present in eight out of the ten patients with decreased α3-subunit staining. The selective reduction in α3-containing GABAA receptors was confirmed using semiquantitative measurements of optical density (OD). The specific changes unique to α3-subunit expression in the superficial neocortical layers of patients with TLE suggest that this subtype is of particular significance in the reorganization of cortical GABAergic systems in focal epileps

3D-LIVE : live interactions through 3D visual environments

This paper explores Future Internet (FI) 3D-Media technologies and Internet of Things (IoT) in real and virtual environments in order to sense and experiment Real-Time interaction within live situations. The combination of FI testbeds and Living Labs (LL) would enable both researchers and users to explore capacities to enter the 3D Tele-Immersive (TI) application market and to establish new requirements for FI technology and infrastructure. It is expected that combining both FI technology pull and TI market pull would promote and accelerate the creation and adoption, by user communities such as sport practitioners, of innovative TI Services within sport events

Genomics of glycopeptidolipid biosynthesis in Mycobacterium abscessus and M. chelonae

<p>Abstract</p> <p>Background</p> <p>The outermost layer of the bacterial surface is of crucial importance because it is in constant interaction with the host. Glycopeptidolipids (GPLs) are major surface glycolipids present on various mycobacterial species. In the fast-grower model organism <it>Mycobacterium smegmatis</it>, GPL biosynthesis involves approximately 30 genes all mapping to a single region of 65 kb.</p> <p>Results</p> <p>We have recently sequenced the complete genomes of two fast-growers causing human infections, <it>Mycobacterium abscessus </it>(CIP 104536T) and <it>M. chelonae </it>(CIP 104535T). We show here that these two species contain genes corresponding to all those of the <it>M. smegmatis </it>"GPL locus", with extensive conservation of the predicted protein sequences consistent with the production of GPL molecules indistinguishable by biochemical analysis. However, the GPL locus appears to be split into several parts in <it>M. chelonae </it>and <it>M. abscessus</it>. One large cluster (19 genes) comprises all genes involved in the synthesis of the tripeptide-aminoalcohol moiety, the glycosylation of the lipopeptide and methylation/acetylation modifications. We provide evidence that a duplicated acetyltransferase (<it>atf1 </it>and <it>atf2</it>) in <it>M. abscessus </it>and <it>M. chelonae </it>has evolved through specialization, being able to transfer one acetyl at once in a sequential manner. There is a second smaller and distant (<it>M. chelonae</it>, 900 kb; <it>M. abscessus</it>, 3 Mb) cluster of six genes involved in the synthesis of the fatty acyl moiety and its attachment to the tripeptide-aminoalcohol moiety. The other genes are scattered throughout the genome, including two genes encoding putative regulatory proteins.</p> <p>Conclusion</p> <p>Although these three species produce identical GPL molecules, the organization of GPL genes differ between them, thus constituting species-specific signatures. An hypothesis is that the compact organization of the GPL locus in <it>M. smegmatis </it>represents the ancestral form and that evolution has scattered various pieces throughout the genome in <it>M. abscessus </it>and <it>M. chelonae</it>.</p