22 research outputs found
Study and interest of cellular load in respiratory samples for the optimization of molecular virological diagnosis in clinical practice
Human metapneumovirus
National audienceThe human metapneumovirus (hMPV) is a new Pneumovirinae related to the avian metapneumovirus type C. hMPV genome differs from human respiratory syncytial virus (RSV) genome by the gene order and the lack of nonstructural genes. Two genetic sub-groups and four sub-types of hMPV are identified. hMPV infections evolve as regular winter outbreaks which have roughly the same size and overlaping RSV epidemics. Among hospitalized children in Caen. hMPV is detected in 9.7% of the cases after RSV (37%), rhinovirus (18%), influenza virus (14.5%), adenovirus (9%), and parainfluenza virus (5%). Most of hMPV infections are observed in children suffering from bronehiolitis, but the localization to lower respiratory tract and the severity of the disease are less frequent in comparison with RSV infections. hMPV is very difficult to isolate using cell culture. Up to now, the only way for hMPV diagnosis was the TS-CRP assays. But the recent apparition of direct antigenic tests allows us to get a fair, rapid, and economic diagnostic tool. (C) 2008 Elsevier Masson SAS
Autoimmune diabetes onset results from qualitative rather than quantitative age-dependent changes in pathogenic T-cells.
Diabetogenic T-cells can be detected in pre-diabetic nonobese diabetic (NOD) mice after transfer in NOD-SCID recipients. Here we demonstrate that 6-week-old pre-diabetic NOD mice, >2 months before disease onset, already harbor pathogenic T-cells in equal numbers to overtly diabetic animals. The delay in diabetes appearance is explained by the presence of regulatory CD4+ CD25+ T-cells that control diabetogenic effectors and that are, in our hands, transforming growth factor (TGF)-beta-dependent. Our present results suggest, however, that diabetes onset is only partly explained by a decline in this regulatory T-cell activity. Another major factor appears to be the progressive resistance of diabetogenic cells to TGF-beta-dependent mediated inhibition. We propose that progression to overt disease correlates with the pathogenic T-cell's escape from TGF-beta-dependent T-cell-mediated regulation
High Performance Computing for the Reduced Basis Method. Application to Natural Convection
In this paper, we are interested in applying the reduced basis methodology (RBM) to
steady-state natural convection problems. The latter has applications in many engineering
domains and being able to apply the RBM would allow to gain huge computation savings when
querying the model for many parameter evaluations. In this work, we focus on the order
reduction of the model — in particular the handling of the non-linear terms, — as well as
the design of the RBM computational framework and the requirements on high performance
computing to treat 3D models using Feel++, a C++ open source library to solve
partial differential equations. Numerical experiments are presented on 2D and 3D
models
A Reduced Basis Framework: Application to large scale non-linear multi-physics problems
In this paper we present applications of the reduced basis method (RBM) to large-scale
non-linear multi-physics problems. We first describe the mathematical framework in place
and in particular the Empirical Interpolation Method (EIM) to recover an affine
decomposition and then we propose an implementation using the open-source library
Feel++ which provides both the reduced basis and finite element layers. Large
scale numerical examples are shown and are connected to real industrial applications
arising from the High Field Resistive Magnets development at the Laboratoire National des
Champs Magnétiques Intenses
Extended generalized Lagrangian multipliers for magnetohydrodynamics using adaptive multiresolution methods
We present a new adaptive multiresoltion method for the numerical simulation of ideal
magnetohydrodynamics. The governing equations, i.e., the compressible
Euler equations coupled with the Maxwell equations are discretized using a finite volume
scheme on a two-dimensional Cartesian mesh. Adaptivity in space is obtained via Harten’s
cell average multiresolution analysis, which allows the reliable introduction of a locally
refined mesh while controlling the error. The explicit time discretization uses a compact
Runge–Kutta method for local time stepping and an embedded Runge-Kutta scheme for
automatic time step control. An extended generalized Lagrangian multiplier approach with
the mixed hyperbolic-parabolic correction type is used to control the incompressibility of
the magnetic field. Applications to a two-dimensional problem illustrate the properties of
the method. Memory savings and numerical divergences of magnetic field are reported and
the accuracy of the adaptive computations is assessed by comparing with the available
exact solution
firedrakeproject/petsc4py: The Python interface to PETSc
firedrakeproject/petsc4py: The Python interface to PETScfiredrakeproject/petsc4py: The Python interface to PETScFiredrake_20190815.
firedrakeproject/petsc4py: The Python interface to PETSc
This release is specifically created to document the version of petsc4py used in a particular set of experiments using Firedrake. Please do not cite this as a general source for Firedrake or any of its dependencies. Instead, refer to https://www.firedrakeproject.org/citing.htmlThis release is specifically created to document the version of petsc4py used in a particular set of experiments using Firedrake. Please do not cite this as a general source for Firedrake or any of its dependencies. Instead, refer to https://www.firedrakeproject.org/citing.html20181204.