Éditeur(s) : HAL CCSD Springer
Résumé : International audience
It is known that a locally Lipschitz function f is approximately convex if, and only if, its Clarke subdifferential ∂C f is a submonotone operator. The main object of this work is to extend the above characterization to the class of lower semicontinuous functions. To this end, we establish a new approximate mean value inequality involving three points. We also show that an analogue of the Rockafellar maximal monotonicity theorem holds for this class of functions and we discuss the case of arbitrary subdifferentials
Mathematical Programming B

hal-00694605
https://hal.archives-ouvertes.fr/hal-00694605

Éditeur(s) : HAL CCSD
Résumé : International audience
Island barriers are common features along the world coastlines. They have a crucial role in protecting inland and rich lagoonal ecosystems. Erosion and sand transfers on these island barriers during extreme events such as tropical storms or typhoons remain poorly investigated. This work focuses on a multi-scales nalysis (season to decade) of the morphodynamics of Wan-Tzu-Liao sand barrier subjected to extreme waves and sea surges. We combine topographic measurements of the emerged beach at seasonal scale between 2011 to 2012 and long-term (1993-2009) shoreline changes using aerial photographs and satellite images. At the seasonal scale, during Monsoon, the sand was taken from the beach-front and transported seaward outside the study area. During typhoons season, 12 typhoons drove a beach recovery process resulting in a seaward shoreline shift. This annual behavior is discussed in term of roll-over process of the barrier. At the decadal scale, the shoreline changes evidence cross-shore processes in the north part of the barrier and longshore processes in the south. Although the chronic landward migration displays several stages, the strong losses of the barrier area occurs only since 2004 and call into question the general concept of conservation of mass during the roll-over of a barrier.
Revue Paralia, XIIIème Journées Nationales Génie CIvil Génie Côtier
Dunkerque, France

hal-01018203
https://hal.archives-ouvertes.fr/hal-01018203

Éditeur(s) : HAL CCSD
Résumé : International audience
It is classically admitted that the goodfriction properties of lamellar compounds are strongly related to their anisotropic structure and especially to the existence of weak interlayer interactions through the van der Waals gap separating the basal layers. As it is also known, the presence of the van der Waals gap in the structure of lamellar compounds will allow lot of chemical species to be intercalated in the structure leading both to the expansion of structure parameters and inter layer interactions modifications. The present work is concerned with the experimental and theoretical study of friction propertiesof Graphite Intercalated Compounds (GICs) in order to better understand thetribologiclamellar compounds. In order to modulate the interlayer interactions, two types of intercalated species were used, electrophylic species (AlCl3, FeCl3, SbCl5) and nucleophilic species (Li, K, Rb).
40th Leeds-Lyon Symposium on Tribology & Tribochemistry Forum 2013
Lyon, France

Droits : info:eu-repo/semantics/OpenAccess
hal-00926509
https://hal.archives-ouvertes.fr/hal-00926509
https://hal.archives-ouvertes.fr/hal-00926509/document
https://hal.archives-ouvertes.fr/hal-00926509/file/Delbe_9781.pdf
OATAO : 9781

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
The nine countries sharing the Amazon forest accounted for 89% of all malaria cases reported in the Americas in 2008. Remote sensing can help identify the environmental determinants of malaria transmission and their temporo-spatial evolution. Seventeen studies characterizing land cover or land use features, and relating them to malaria in the Amazon subregion, were identified. These were reviewed in order to improve the understanding of the land cover/use class roles in malaria transmission. The indicators affecting the transmission risk were summarized in terms of temporal components, landscape fragmentation and anthropic pressure. This review helps to define a framework for future studies aiming to characterize and monitor malaria.
ISSN: 1475-2875

inserm-00834790
http://www.hal.inserm.fr/inserm-00834790
http://www.hal.inserm.fr/inserm-00834790/document
http://www.hal.inserm.fr/inserm-00834790/file/1475-2875-12-192.pdf
DOI : 10.1186/1475-2875-12-192

Éditeur(s) : HAL CCSD IOP Publishing
Résumé : International audience
Based on the very recent work by Censor and Segal (2009 J. Convex Anal. 16 587-600) and inspired by Xu (2006 Inverse Problems 22 2021-34) and Yang (2004 Inverse Problems 20 1261-6), we investigate an algorithm for solving the split common fixed-point problem for the class of demicontractive operators in a Hilbert space. Our results improve and/or develop previously discussed feasibility problems and related algorithms. It is worth mentioning that the convex feasibility formalism is at the core of the modeling of many inverse problems and has been used to model significant real-world problems, for instance, in sensor networks, in radiation therapy treatment planning, in computerized tomography and data compression, see Censor et al (2006 Phys. Med. Biol. 51 2353-65) and Combettes (1996 Adv. Imaging Electron. Phys. 95 155-270) and references therein.
ISSN: 0266-5611

hal-00778174
https://hal.univ-antilles.fr/hal-00778174
DOI : 10.1088/0266-5611/26/5/055007

Éditeur(s) : HAL CCSD
Résumé : 32 pages
Wind energy production is very sensitive to instantaneous wind speed fluctuations. Thus rapid variation of wind speed due to changes in the local meteorological conditions can lead to electrical power variations of the order of the nominal power output. In small grids, as they exist for example on some islands in the French West Indies, such fluctuations can cause instabilities in case of intermediate power shortages. To palliate these difficulties, it is essential to identify and characterize the wind speed distributions. This allows to anticipate the eventuality of power shortage or power surge. Therefore, it is of interest to categorize wind speed fluctuations into distinct classes and to estimate the probability of a distribution to belong to a class. This paper presents a method for classifying wind speed histograms by estimating a finite mixture of Dirichlet distributions. The SAEM algorithm that we use provides a fine distinction between wind speed distribution classes. It's a new nonparametric method for wind speed sequences classification. However, we show that the wind speed distributions in each class correspond to specific Gram- Charlier densities.
https://hal.archives-ouvertes.fr/hal-00319608

hal-00319608
https://hal.archives-ouvertes.fr/hal-00319608
https://hal.archives-ouvertes.fr/hal-00319608v2/document
https://hal.archives-ouvertes.fr/hal-00319608/file/Article_dirichlet.pdf
ARXIV : 0810.4422

Éditeur(s) : HAL CCSD
Résumé : 18 pages
This article adresses questions on localization and microlocalization in the framework of the so called (C,E,P)-algebras of generalized functions. We give new results on nonlinear properties of the asymptotic singular spectrum in the multi-parameter case, a tool to describe the singularities of generalized solutions associated to problems which are classically ill-posed. Wa apply the theory to a transport equation with strongly irregular coefficients and initial data.
https://hal.univ-antilles.fr/hal-00761112

hal-00761112
https://hal.univ-antilles.fr/hal-00761112
https://hal.univ-antilles.fr/hal-00761112/document
https://hal.univ-antilles.fr/hal-00761112/file/DT2010-03_Devoue_al3.pdf

Éditeur(s) : HAL CCSD
Résumé : Aricle soumis à Solar Energy
In order to qualify the fluctuating nature of solar radiation under tropical climate, we classify daily distributions of the clearness index kt by estimating a finite mixture of Dirichlet distributions without assuming any parametric hypothesis on these daily distributions. The method is applied to solar radiation measurements performed in Guadeloupe (16°2 N, 61 W) where important fluctuations can be observed even within a short period of a few minutes. The results put in evidence four distinct classes of distributions corresponding to different types of days. The sequence of such classes can be of interest for prediction.
https://hal.archives-ouvertes.fr/hal-00289567

hal-00289567
https://hal.archives-ouvertes.fr/hal-00289567
https://hal.archives-ouvertes.fr/hal-00289567/document
https://hal.archives-ouvertes.fr/hal-00289567/file/Article_Classif_soumis.pdf

Éditeur(s) : HAL CCSD
Résumé : ABSTRACT Infectious complications are a leading cause of morbidity and mortality in patients with sickle cell disease. The exact reasons of the propensity of sickle cell patients to infection are not clear and are matter of debate. Besides, there is a striking variability of the clinical course of the disease between patients. This drew many scientists' attention. Genetic factors have been investigated as potential factor risks for infection in sickle cell patients, for example: HLA system; genes encoding Fc Human Immunoglobulin G receptor IIA, mannose-binding protein, and myeloperoxidase. Associations have been found, but all scientists agree that investigations have to be furthered. We investigated an association between HLA DRB1 and DQB1 polymorphism and infectious complications in sickle cell patients. Genotype frequencies were different between cases and controls for DRB1 locus. Indeed, HLA-DRB1*11 frequency was significantly higher in patients without infections than in patients with infections (χ² = 5.02; p = 0.025).
https://hal.archives-ouvertes.fr/hal-00387082

hal-00387082
https://hal.archives-ouvertes.fr/hal-00387082
https://hal.archives-ouvertes.fr/hal-00387082/document
https://hal.archives-ouvertes.fr/hal-00387082/file/MO_JOANNES_et_al_HLA_and_SCD.pdf

Éditeur(s) : HAL CCSD
Résumé : Macrophages (MΦ), well-known to play a key role in immune response, also respond to environmental toxic chemicals such as diesel exhaust particles (DEP), an air pollutant recently classified as carcinogenic to humans. MΦ are heterogeneous and plastic cells which activate according to their microenvironment into either an M1 subtype (so called classically activated or pro-inflammatory) under IFNγ and LPS stimulation or an M2 subtype (so called alternatively activated or anti-inflammatory) under IL-4 and/or IL-13 stimulation. However, potential effects of DEPs on M1/M2 MΦ polarization remain poorly documented. First, we characterized the expression marker of in vitro M-CSF-differentiated MΦ from human monocytes and activated into the M1 or M2 subtypes. Our main results show that M-CSF-generated MΦ considered as anti-inflammatory are actually able to switch to an M1 phenotype after IFNγ/LPS stimulation. Furthermore, the markers identified in this study were used to assess the impact of organic extracts of DEP (DEPe) on MΦ polarization and more generally on their physiology. DEPe alter some M1 and M2 markers expressed by polarized MΦ, without causing the overall inhibition of the M1 and M2 polarization process or the switch to a different phenotype. This phenotype alteration is associated with a decrease in the LPS-dependent inflammatory response in M1 MΦ and the chemotactic capacities in M2 MΦ. DEPe decrease the secretion of some cytokines and chemokines such as IL-6, IL-12p40 and CCL18 via AhR and/or Nrf2 activation. At the same time, we show that M1 and M2 MΦ in response to DEPe are able to secrete a sufficient level of a pro-fibrotic growth factor, the platelet derived growth factor B (PDGF-B) via AhR activation, leading to stimulation of lung fibroblast proliferation. Finally, these works show that DEPe have immunotoxic properties with regards to the physiology of human in vitro polarized MΦ. This immunotoxicity may then contribute to the deleterious effects of these urban environmental contaminants on human health.
Les macrophages (MΦ), des cellules clefs de la réponse immunitaire peuvent répondre à des contaminants environnementaux comme les particules diesel (DEP), des polluants atmosphériques récemment classés cancérigènes pour l'Homme. Les MΦ sont des cellules hétérogènes et plastiques qui s'activent en fonction de leur microenvironnement soit en MΦ M1 (dits classiquement activés ou pro-inflammatoires) sous l'effet de l'INFγ et du LPS soit en MΦ M2 (dits alternativement activés ou réparateurs) sous l'effet de l'IL-4 et/ou de l'IL-13. Les effets des DEP sur la polarisation M1/M2 des MΦ restent peu documentés. Nous avons dans un premier temps caractérisé l'expression des marqueurs des MΦ différenciés in vitro en présence de M-CSF à partir de monocytes humains et polarisés en sous-type M1 ou M2. Nos principaux résultats montrent que les MΦ différenciés au M-CSF considérés comme des MΦ anti-inflammatoires, sont en réalité capables de s'activer vers un phénotype M1 après une stimulation au LPS/IFNγ. De plus, les marqueurs mis en évidence au cours de ce travail ont permis d'évaluer l'impact d'extraits organiques de DEP (DEPe) sur la polarisation des MΦ et plus généralement sur leur physiologie. Les DEPe altèrent l'expression de certains marqueurs M1 et M2 des MΦ, sans toutefois provoquer d'inhibition globale des processus de polarisation M1 et M2 ou de transition d'un phénotype vers un autre. Cette altération du phénotype est associée à une diminution de la réponse inflammatoire LPS-dépendante dans les MΦ M1 et des capacités chimiotactiques des MΦ M2. Les DEPe diminuent la sécrétion de certaines cytokines et chimiokines comme l'IL-6, l'IL-12p40 et le CCL18 via l'activation d'AhR et/ou de Nrf2. Parallèlement, nous montrons que les MΦ M1 et M2 exposés aux DEPe sécrètent le platelet deried growth factor B (PDGF-B), un facteur de croissance profibrosant, via l'activation d'AhR en quantité suffisante pour stimuler la prolifération de fibroblastes pulmonaires. Au total, ces travaux démontrent que les DEP possèdent des propriétés immunotoxiques vis-à-vis de la physiologie des macrophages humains polarisés in vitro. Cette immunotoxicité pourrait participer aux effets délétères de ces contaminants environnementaux urbains sur la santé humaine.
https://tel.archives-ouvertes.fr/tel-01188679

NNT : 2015REN1S011
tel-01188679
https://tel.archives-ouvertes.fr/tel-01188679
https://tel.archives-ouvertes.fr/tel-01188679/document
https://tel.archives-ouvertes.fr/tel-01188679/file/JAGUIN_Marie.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
The present research work is a part of the KUNSHEN Franco-Taiwanese research project which aims at investigating the hydro/morphodynamics of barrier islands driven by typhoon events. This study focuses on the impact of the Talim tropical storm on the Wan-tzu-liao sand barrier (Taiwan) in terms of water level rising and watertable overheight. In-situ measurements are provided by a cross-shore network of pressure sensors extended from the intertidal zone to the top of the barrier. Extreme offshore wave conditions are encountered during Talim, with significant wave height greater than 10m at the storm peak. It is shown that measured setups are smaller than those predicted by usual empirical parameterization. Groundwater dynamics is strongly affected by the storm, with watertable overheight of the order of one meter under the barrier top. Watertable dynamics is influenced by waves, tides and rainfalls.
Coastal Dynamics 2013

hal-00831573
https://hal.archives-ouvertes.fr/hal-00831573

Éditeur(s) : HAL CCSD
Résumé : International audience
https://hal.archives-ouvertes.fr/hal-01436542

hal-01436542
https://hal.archives-ouvertes.fr/hal-01436542
DOI : 10.1109/IGARSS.2011.6049595

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
In this work, we have studied quenching of the fluorescence of two well-known oxygen probes, 1-pyrene butyric acid (PBA) and tris(2,2'-bipyridine)ruthenium ([Ru(bpy)(3)](2+)) by reactive oxygen species (superoxide anion, nitric oxide derivative, hydrogen peroxide) and by the O(2) molecule. Both, time-resolved and steady state fluorescence measurements were performed in solution (ethanol, dimethyl sufoxide, water) and in micelles of Sodium Dodecyl Sulfate that serve as a model for membrane-containing biological structures. We have found that only the free radicals and O(2) can actively quench for the two probes, but not the diamagnetic H(2)O(2). Our data correspond to the classical Stern-Volmer equation. H(2)O(2) has an effect only at high molar concentrations (>0.1 M). In contrast, effective concentrations of free radicals and O(2) that lead to quenching are in millimolar range. In conclusion, our methods allows for detecting global ROS that are small free radicals without interference from the reactive hydroxyl radical. Our data suggest that the method can be used for the quantification of ROS in individual living cells based on the measurement of fluorescence lifetime of those probes
ISSN: 1053-0509

hal-01326234
https://hal.archives-ouvertes.fr/hal-01326234
DOI : 10.1007/s10895-008-0425-z

Éditeur(s) : HAL CCSD
Résumé : Similarity-based diversity (Leinster and Cobbold 2012) encompasses classical measures of diversity, including the number of species, Shannon and Simpson diversity, and also phylogenetic and functional diversity. We derive two estimators to allow applying it to real, often under-sampled data, and its decomposition into alpha, beta and gamma diversity when an assemblage of communities is considered.
https://hal-agroparistech.archives-ouvertes.fr/hal-00989454

hal-00989454
https://hal-agroparistech.archives-ouvertes.fr/hal-00989454
https://hal-agroparistech.archives-ouvertes.fr/hal-00989454v3/document
https://hal-agroparistech.archives-ouvertes.fr/hal-00989454/file/DqZ%20%28HAL%29.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
The carbon capture and storage is considered as one of the solutions of reducing the effects of global warming. It consists in injecting large quantities of CO 2 in supercritical form directly into deeply located geological formations. One of the methods involves sequestration in the carbonate sedimentary rocks (sandstones and limestones) which are considered as a promising solution. The morphology of the pore network and solid skeleton defines important macroscopic prop-erties of the rock (permeability, stiffness). Modelling at micro scale of random heterogeneous materials (porous media) should be based on morphological and statistical characterisation 1,2 of the investigated microstructure. The work is focused on a reconstruction method by grains deposit 3 , for various range of pa-rameters, to obtain equivalent model of natural rock samples (oolitic limestone and fontainebleau sandstone). Generated samples satisfy morphological and statistical informations 4 which were obtained by 3D image analysis of X-ray tomography of the natural rock samples. For validation of the modelling numerical computations of mechanical and transfer properties are also provided.
14th European Mechanics of Materials Conference - EMMC14
Gothembourg, Sweden

hal-01103163
https://hal.archives-ouvertes.fr/hal-01103163

Éditeur(s) : HAL CCSD
Résumé : A standard approach for large scale image classification involves high dimensional features and Stochastic Gradient Descent algorithm (SGD) for the minimization of classical Hinge Loss in the primal space. Although complexity of Stochastic Gradient Descent is linear with the number of samples these method suffers from slow convergence. In order to cope with this issue, we propose here a Stochastic Low-Rank Newton Descent SLND for minimization of any calibrated loss in the primal space. SLND approximates the inverse Hessian by the best low-rank approximation according to squared Frobenius norm. We provide core optimization for fast convergence. Theoretically speaking, we show explicit convergence rates of the algorithm using these calibrated losses, which in addition provide working sets of parameters for experiments. Experiments are provided on the SUN, Caltech256 and ImageNet databases, with simple, uniform and efficient ways to tune remaining SLND parameters. On each of these databases, SLND challenges the accuracy of SGD with a speed of convergence faster by order of magnitude.
https://hal.archives-ouvertes.fr/hal-00825414

hal-00825414
https://hal.archives-ouvertes.fr/hal-00825414
https://hal.archives-ouvertes.fr/hal-00825414/document
https://hal.archives-ouvertes.fr/hal-00825414/file/TechnicalReport.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
The extraction of knowledge from social networks is an area that has experienced significant growth in recent years. Indeed, thanks to the improvement of storage and calculation capacities, and the heterogeneity of data that can currently be extracted, much effort has been made to go beyond traditional knowledge, by proposing new kinds of patterns that take into account the context. However, while many works were interested in designing new patterns of knowledge or in optimizing existing approaches, few studies have been focused in merging patterns and on the useful knowledge emerging from such fusions. In this work, we focus on two network clustering approaches, able to extract two distinct kinds of patterns, and we seek to understand both the intersections that can exist between them and the knowledge that emerges from their fusion. The first is the classical nodes clustering approach that consists in searching for communities into a network. The second is the search for frequent conceptual links, a new link clustering approach that aims identifying frequent links between groups of nodes sharing common attributes. We propose a set of original measures that aim to evaluate the amount of shared information between these patterns when they are extracted from a same network. These measures are applied to three datasets and demonstrate the interest in simultaneously considering several sources of knowledge.
Advances in Knowledge Discovery and Management (AKDM)

hal-01514227
https://hal.archives-ouvertes.fr/hal-01514227
DOI : 10.1007/978-3-319-45763-5_13

Éditeur(s) : HAL CCSD Springer Verlag/EDP Sciences
Résumé : International audience
Context: Woodcutting is a very old technology but scientific research is scarce on the subject. In the last 50 years much work on basic mechanisms as well as industrial processes has been done in France. Aims: The specific nature of wood introduces strong differences between wood and metal cutting processes. The paper focuses on French teams' contributions. Results: The basic aspects of the tool–material interaction for different basic modes in woodcutting are highlighted. In primary conversion such as sawing, veneer cutting or green wood chipping, huge progress comes from automation and the possibility of linking the process to log and product quality through new sensors. In secondary processing much has been done on the links between the cutting process, surface qualification and the properties of these surfaces for further processing, such as gluing or coating. Tool wear depends on the cutting process, timber quality, and species. Trade-offs are required in tool technology and coating technologies may improve tool life. Conclusion: A large amount of knowledge and innovation has come from 50 years of worldwide research effort, with France being particularly active in this period. The transfer of skills from metals cutting industry was often a key, but much is needed to move closer to both metal cutting sector and woodcutting skills among craftsmen.
ISSN: 1286-4560

hal-01135156
https://hal.archives-ouvertes.fr/hal-01135156
https://hal.archives-ouvertes.fr/hal-01135156/document
https://hal.archives-ouvertes.fr/hal-01135156/file/Wood_machining_focus_French_research_Thibaut_al_2015.pdf
DOI : 10.1007/s13595-015-0460-2

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The present work is concerned with the study of the tribological properties of various fluorinated carbon phases obtained at room temperature and then post-treated under fluorine atmosphere at different temperatures. The tribological tests evidence good intrinsic properties for all the compounds (friction coefficient in the range 0.07-0.09). Differences appear after few cycles. Friction measurements after 100 cycles and complementary Raman analyses of the tribofilm remaining in the wear scar point out that long term tribologic properties of the fluorinated compounds strongly depend on the evolution undergone by the materials under friction. The release of HF molecules, the loss of fluorine and partial rebuilding of graphitic phases are at the origin of the degradation of the friction properties. The good properties of the compounds post-treated at temperature in the range 150-300 °C are attributed to the chemical and structural stability of these compounds under friction.
ISSN: 0022-3697

hal-00756133
https://hal.archives-ouvertes.fr/hal-00756133
https://hal.archives-ouvertes.fr/hal-00756133/document
https://hal.archives-ouvertes.fr/hal-00756133/file/Delbe_6346.pdf
DOI : 10.1016/j.jpcs.2006.01.084

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
BACKGROUND AND AIMS: Infection by hepatitis C virus is a worldwide health problem. An inadequate Th2 cytokine response promotes the fibrosis-cirrhosis fate. Immune-modulating molecules favoring a Th2 profile, such as HLA-G molecules of the HLA class Ib family, may play a role in chronic hepatitis. HLA-G contributes to the escape of tumors, and their involvement in viral infections has been increasingly described. The aim of this work was to study the expression of HLA-G in the liver, its cellular source and its regulation in cases of chronic C hepatitis. METHODS: HLA-G cells in blocks of liver derived from patients infected with HCV were labeled by immunohistochemistry and enumerated. Double immunofluorescence allowed the identification of the cellular source. HLA-G secretion by a human mast cell line was quantified by ELISA after various stimulations. After treatment with IFN-α real-time PCR was performed to determine the kinetics of cytokine expression profiles, followed by heat map clustering analysis. RESULTS: The number of HLA-G + cells was significantly associated with the area of fibrosis. For the first time, we identify the HLA-G+ cells as being mast cells. HLA-G secretion was significantly induced in human mast cells stimulated by IL-10 or interferons of class I. The transcriptome of the secretome of this cell line stimulated by IFN-α revealed that i) the HLA-G gene is upregulated late, ii) T lymphocytes and NK cells are recruited. CONCLUSIONS: These findings suggest an autocrine loop in the genesis of HCV liver fibrosis, based on mast cells expressing HLA-G.
ISSN: 0168-8278

hal-00874106
https://hal.archives-ouvertes.fr/hal-00874106
https://hal.archives-ouvertes.fr/hal-00874106/document
https://hal.archives-ouvertes.fr/hal-00874106/file/Amiot-Expression-HLA-G-revised.pdf
DOI : 10.1016/j.jhep.2013.09.006