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Treatable causes of fever among children under five years in a seasonal malaria transmission area in Burkina Faso

Infectious Diseases of Poverty 2018年第1期7卷 583-592页

作者： francois kiemde Marc Christian Tahita Palpouguini Lompo Toussaint Rouamba Athanase M.Some Halidou Tinto Petra F.Mens Henk D.F.H.Schallig Michael Boele van Hensbroek Institut de Recherche en Science de la Sante-Unite de Recherche Clinique de Nanoro NanoroBurkina Faso Academic Medical Centre Department of Medical MicrobiologyParasitology UnitAmsterdamThe Netherlands Global Child Health Group Academic Medical CentreUniversity of AmsterdamAmsterdamThe Netherlands

Background:Fever remains a major public health *** Burkina Faso,more than half of febrile children are considered not to be infected by *** study prospectively assessed probable(treatable)causes of fever in Burkinabe ***:A prospective study was conducted among febrile children(≥37.5°C)under 5 years of age presenting at four health facilities and one referral hospital in rural Burkina *** each participant,blood was collected for malaria microscopy and culture,urine for dipstick testing and culturing if tested positive for leucocytes and nitrite,stool for rotavirus/adenovirus testing,culture and parasitology,and a nasopharyngeal swab for ***:In total 684 febrile children were included in the *** falciparum malaria was found in 49.7%(340/684)of the participants and non-malaria infections in 49.1%(336/684)of *** non-nalaria infections included gastro-intestinal infections(37.0%),common bacterial pathogens of nasopharynx(24.3%),bacterial bloodstream infections(6.0%)and urinary tract infections(1.8%).Nearly 45%(154/340)of the malaria infected children were co-infected with non-nalaria infections,but only 3.2%(11/340)of these co-infections could be considered as a possible alternative cause of *** contrast,in the malaria microscopy negative children 18.0%(62/344)of the infections could be the probable cause of the *** were not isolated from 23.7%(162/684)of the febrile ***:Malaria remains the most common pathogen found in febrile children in Burkina ***,a relative high number of febrile children had non-malaria *** correct diagnosis of these non-malaria fevers is a major concern,and there is an urgent need to develop more point-of-care diagnostic tests and capacities to identify and treat the causes of these fevers.

关键词： Fever Children Infectious diseases Malaria

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Inverse Scattering for a Schr■dinger Operator with a Repulsive Potential

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1485-1492页

作者： francois NICOLEAU Laboratoire de Mathéatiques Jean Leray UMR CNRS-UN 6629 Département de Mathématiques2 rue de la Houssinière BP 92208 F-44322 Nantes cedex 03 France

We consider a pair of Hamiltonians （H, H0） on L2（R^n）, where H0=p^2 -x^2 is a SchrSdinger operator with a repulsive potential, and H = H0＋V（x）. We show that, under suitable assumptions on the decay of the elect... 详细信息

关键词： Inverse scattering Repulsive potential

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Visualization of bHLH transcription factor interactions in living mammalian cell nuclei and developing chicken neural tube by FRET

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Cell Research 2006年第6期16卷 585-598页

作者： francois Guillemot UK London NW7 1AA Mill Hill Division of Molecular Neurobiology National Institute for Medical Research The Ridgeway

Members of the basic helix-loop-helix(bHLH)gene family play important roles in vertebrate *** thisstudy,confocal microscopy-based fluorescence resonance energy transfer(FRET)is used to monitor bHLH protein-proteininteractions under various physiological ***-specific bHLH activators,NeuroD1,Mashl,Neurogeninl(Ngn1),Neurogenin2(Ngn2),and ubiquitous expressed E47 protein are tagged with enhanced yellow fluorescenceprotein(EYFP)and enhanced cyan fluorescence protein(ECFP),*** subcellular localization and mobilityof bHLH fusion proteins are examined in HEK293 *** transient transfection and in ovo electroporation,four pairsof tissue-specific bHLH activators and E47 protein are over-expressed in HEK293 cells and developing chick embryoneural *** the acceptor photobleaching method,FRET could be detected between these bHLH protein pairs inthe nuclei of transfected cells and developing neural ***/E47 and Ngn2/E47 FRET pairs show higher FRETefficiencies in the medial and the lateral half of chick embryo neural tube,*** suggests that these bHLHprotein pairs formed functional DNA-protein complexes with regulatory elements of their downstream target genes inthe specific *** work will help one understand the behaviours of bHLH factors in vivo.

关键词： bHLH confocal microscopy chick embryo neural tube FRET in ovo electroporation photobleach

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Conditions for Set Agreement with an Application to Synchronous Systems

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Journal of Computer Science & Technology 2009年第3期24卷 418-433页

作者： francois Bonnet Michel Raynal IRISA University of Rennes35042 Rennes CedexFrance

The k-set agreement problem is a generalization of the consensus problem： considering a system made up of n processes where each process proposes a value, each non-faulty process has to decide a value such that a decided value is a proposed value, and no more than k different values are decided. While this problem cannot be solved in an asynchronous system prone to t process crashes when t≥ k, it can always be solved in a synchronous system; [t/k]＋1 is then a lower bound on the number of rounds （consecutive communication steps） for the non-faulty processes to decide. The condition-based approach has been introduced in the consensus context. Its aim was to both circumvent the consensus impossibility in asynchronous systems, and allow for more efficient consensus algorithms in synchronous systems. This paper addresses the condition-based approach in the context of the k-set agreement problem. It has two main contributions. The first is the definition of a framework that allows defining conditions suited to the l-set agreement problem and the second is a generic synchronous k-set agreement algorithm based on conditions.

关键词： agreement problem condition efficiency lower bound synchronous system

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Discrete Duality Finite Volume Discretization of the Thermal-P_(N) Radiative Transfer Equations on General Meshes

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Communications in Computational Physics 2022年第2期31卷 398-448页

作者： francois Hermeline Universite Paris-Saclay Laboratoire en Informatique Haute Performance pour le Calcul et la simulationCEADAMDIF91297 ArpajonFrance

The discrete duality finite volume method has proven to be a practical tool for discretizing partial differential equations coming from a wide variety of areas of physics on nearly arbitrary *** main ingredients of the method are:(1)use of three meshes,(2)use of the Gauss-Green theorem for the approximation of derivatives,(3)discrete integration by *** this article we propose to extend this method to the coupled grey thermal-P_(N) radiative transfer equations in Cartesian and cylindrical coordinates in order to be able to deal with two-dimensional Lagrangian approximations of the interaction of matter with *** stability under a Courant-Friedrichs-Lewy condition and the preservation of the diffusion asymptotic limit are proved while the experimental second-order accuracy is observed with manufactured *** numerical experiments are reported which show the good behavior of the method.

关键词： Hybrid multiscale models radiative transfer equation grey P_(N)approximation discrete duality finite volume method

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Maximizing the Delivery of MPR Broadcasting Under Realistic Physical Layer Assumptions

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Journal of Computer Science & Technology 2008年第3期23卷 451-460页

作者： francois Ingelrest David Simplot-Ryl LCAV EPFLCH-1015LausanneSwitzerland IRCICA/LIFL CNRS UMR 8022Univ.Lille 1INRIA Lille-Nord EuropeFrance

It is now commonly accepted that the unit disk graph used to model the physical layer in wireless networks does not reflect real radio transmissions, and that a more realistic model should be considered for experimental simulations. Previous work on realistic scenarios has been focused on unicast, however broadcast requirements are fundamentally different and cannot be derived from the unicast case. Therefore, the broadcast protocols must be adapted in order to still be efficient under realistic assumptions. In this paper, we study the well-known multipoint relay broadcast protocol （MPR）, in which each node has to choose a set of 1-hop neighbors to act as relays in order to cover the whole 2-hop neighborhood. We give experimental results showing that the original strategy used to select these multipoint relays does not suit a realistic model. On the basis of these results, we propose new selection strategies solely based on link quality. One of the key aspects of our solutions is that our strategies do not require any additional hardware and may be implemented at the application layer, which is particularly relevant to the context of ad hoc and sensor networks where energy savings are mandatory. We finally provide new experimental results that demonstrate the superiority of our strategies under realistic physical assumptions.

关键词： ad hoc network multipoint relay broadcasting realistic physical layer sensor network

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The Micromechanics of Biological and Biomimetic Staggered Composites

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Journal of Bionic Engineering 2012年第4期9卷 446-456页

作者： Sacheen Bekah Reza Rabiei francois Barthelat Department of Mechanical Engineering McGill University 817 Sherbrooke Street West Montreal QC H3A 2K6 Canada

Natural materials such as bone, tooth and nacre achieve attractive properties through the ＂staggered structure＂, which consists of stiff, parallel inclusions of large aspect ratio bonded together by a more ductile and tougher matrix. This seemingly simple structure displays sophisticated micromechanics which lead to unique combinations of stiffness, strength and toughness. In this article we modeled the staggered structure using finite elements and small Representative Volume Elements （RVEs） in order to explore microstructure-property relationships. Larger aspect ratio of inclusions results in greater stiffiless and strength, and also significant amounts of energy dissipation provided the inclusions do not fracture in a brittle fashion. Interestingly the ends of the inclusions （the junctions） behave as crack-like features, generating theoretically infinite stresses in the adjacent inclusions. A fracture mechanics criterion was therefore used to predict the failure of the inclusions, which led to new insights into how the interfaces act as a ＂＇soft wrap＂ for the inclusions, completely shielding them from excessive stresses. The effect of statistics on the mechanics of the staggered structure was also assessed using larger scale RVEs. Variations in the microstructure did not change the modulus of the material, but slightly decreased the strength and significantly decreased the failure strain. This is explained by strain localization, which can in turn be delayed by incorporating waviness to the inclusions. In addition, we show that the columnar and random arrangements, displaying different deformation mechanisms, lead to similar overall prop- erties. The guidelines presented in this study can be used to optimize the design of staggered synthetic composites to achieve mechanical performances comparable to natural materials.

关键词： biological materials biomimetics representative volume element fracture mechanics finite element analysis

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Multiscale Mechanics and Optimization of Gastropod Shells

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Journal of Bionic Engineering 2011年第4期8卷 357-368页

作者： Mostafa Yourdkhani Damiano Pasini francois Barthelat Department of Mechanical Engineering McGill University 817 Sherbrooke Street West Montreal QC H3A 2K6 Canada

A vast majority of mollusks grow a hard shell for protection. The structure of these shells comprises several levels of hierarchy that increase their strength and their resistance to natural threats. This article focuses on nacreous shells, which are composed of two distinct layers. The outer layer is made of calcite, which is a hard but brittle material, and the inner layer is made of nacre, a tough and ductile material. The inner and outer layers are therefore made of materials with distinct structures and properties. In this article, we demonstrate that this system is optimum to defeat attacks from predators. A two-scale mod- eling and optimization approach was used. At the macroscale, a two-layer finite element model of a seashell was developed to capture shell geometry. At the microscale, a representative volume element of the microstructure of nacre was used to model the elastic modulus of nacre as well as a multiaxial failure criterion, both expressed as function of microstructural parameters. Experiments were also performed on actual shells of red abalone to validate the results obtained from simulations and gain insight into the way the shell fails under sharp perforation. Both optimization and experimental results revealed that the shell displays optimum performance when two modes of failure coincide within the structure. Finally, guidelines for designing two-layer shells were proposed to improve the performance of engineered protective systems undergoing similar structural and loading conditions.

关键词： seashell multiscale modeling representative volume element failure criterion nacre multiscale optimization

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Development of a portable reference aerosol generator （PRAG） for calibration of particle mass concentration measurements

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Particuology 2018年第2期16卷 134-142页

作者： francois Gaie-Levrel Soleiman Bourrous Tatiana Macé Laboratoire national de metrologie et d'essais (LNE) Chemistry and Biology Division Gas and Aerosol Metrology Department I Rue Caston Boissier 75724 Paris Cedex 15 France Institut de Radioprotection et de SUreté Nucleaire (LRSN) PSNRES SCA Gif-sur-Yvette 91192 France

The tapered element oscillating microbalance with filter dynamics measurement system （TEOM-FDMS） is an instrument commonly employed by the French air quality monitoring network. This instrument is currently calibrated with calibration weights traceable to SI but having value and mass differences between each of them that are not representative of real atmospheric particle mass measurements. Moreover, these calibration weights do not allow detection of any technical problems associated with either the TEOM-FDMS sampling system upstream of the mass measurement or the intrinsic TEOM-FDMS filtration system. Therefore, a calibration method was developed using a portable reference aerosol generator （PRAG） that produces known and stable particle mass concentrations over time. Here, we present the characterization of the PRAG system in terms of a reference range of particle masses between 30 - 10 and 3456 ± 83 μg at three sampling times. Its coupling with the TEOM-FDMS and a global comparison between the defined reference range of particle masses and the measured masses obtained with each TEOM-FDMS implicated in this study are also presented.

关键词： Aerosol Generator Mass concentration Particulate mass Calibration TEOM-FDMS

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On Single Distribution Lattice Boltzmann Schemes for the Approximation of Navier Stokes Equations

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Communications in Computational Physics 2023年第8期34卷 613-671页

作者： francois Dubois Pierre Lallemand Laboratoire de Mathematiques d’Orsay Faculte des Sciences d’OrsayUniversite Paris-SaclayFrance Conservatoire National des Arts et Metiers LMSSC laboratoryParisFrance International Research Laboratory 3457 Centre National de la Recherche ScientifiqueCentre de Recherches MathematiquesUniversite de MontrealMontrealQCCanada Beijing Computational Science Research Center Haidian DistrictBeijing 100094China

In this contribution we study the formal ability of a multi-resolution-times lattice Boltzmann scheme to approximate isothermal and thermal compressible Navier Stokes equations with a single particle *** precisely,we consider a total of 12 classical square lattice Boltzmann schemes with prescribed sets of conserved and nonconserved *** question is to determine the algebraic expressions of the equilibrium functions for the nonconserved moments and the relaxation parameters associated to each *** compare the fluid equations and the result of the Taylor expansion method at second order accuracy for bidimensional examples with a maximum of 17 velocities and three-dimensional schemes with at most 33 *** some cases,it is not possible to fit exactly the physical *** several examples,we adjust the Navier Stokes equations and propose nontrivial expressions for the equilibria.

关键词： Partial differential equations asymptotic analysis

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