Approximating partial derivatives of first and second order by quadratic spline quasi-interpolants

paru dans la revue sous le titre : Approximating partial derivatives of first and second order by quadratic spline quasi-interpolants on uniform meshesGiven a bivariate function $f$ defined in a rectangular domain $\omega$, we approximate it by a $C^1$ quadratic spline quasi-interpolant (abbr. QI) and we take partial derivatives of this QI as approximations to those of $f$. We give error estimates and asymptotic expansions for these approximations. We also propose a simple algorithm for the determination of stationary points, illustrated by a numerical example

Quadratic spline quasi-interpolants and collocation methods

International audienceUnivariate and multivariate quadratic spline quasi-interpolants provide interesting approximation formulas for derivatives of approximated functions that can be very accurate at some points thanks to the superconvergence properties of these operators. Moreover, they also give rise to good global approximations of derivatives on the whole domain of definition. From these results, some collocation methods are deduced for the solution of ordinary or partial differential equations with boundary conditions. Their convergence properties are illustrated on some numerical examples of elliptic boundary value problems

Entre l’Adour et la Baïse (partie occidentale du département du Gers, France) : une importante source de matières premières siliceuses du Sénonien

La région étudiée correspond à la partie occidentale du département du Gers. Elle couvre une partie de la vallée de l’Adour, de ses affluents (Izaute, Midour, Douze) et de la vallée de la Gélise. Une étude géologique et une collecte de 290 galets alluviaux provenant des formations plio-quaternaires et couvrant les parties sommitales de cette région ont été réalisées de 2010 à 2012. Parallèlement, l’examen de 132 artefacts de gisements gersois attribuables au Paléolithique supérieur a été mené. Les matériaux recueillis ont été soumis à des analyses pétrographiques, sédimentologiques et paléontologiques. Elles ont conduit à discerner 19 types lithologiques qui ont été caractérisés :- un seul type est attribuable au Cénozoïque ;- deux types sont caractéristiques des formations du Flysch pyrénéen ;- dix types paraissent attribuables au Sénonien (du Coniacien au Campanien) ;- six types contiennent une microfaune du Maastrichtien supérieur à Lepidorbitoides.Ces types ont été regroupés en six groupes qui mettent en valeur les niveaux stratigraphiques et les environnements paléogéographiques des différentes époques. Il en est ressorti que seulement 0,2 % des galets alluvionnaires proviennent des formations crétacées du Flysch pyrénéen, 45 % sont issus du Maastrichtien supérieur à Lepidorbitoides, et 54 % du Sénonien (Coniacien à Campanien). Les artefacts en silex collectés dans la même région donnent des résultats très comparables (49 % de Maastrichtien).En conclusion, on peut retenir, à ce jour, que cette partie du plateau du Lannemezan présente des zones alluvionnaires du Plio-Pleistocène qui montrent une forte teneur en galets de silex pour lesquels nous avons établi une origine géologique sénonienne et maastrichtienne. L’utilisation de ces matériaux lithiques au Paléolithique supérieur est évidente.La mise en évidence d’une nouvelle source de matières premières dans la partie méridionale du bassin d’Aquitaine sera à prendre en compte et remet sans doute en question nombre d’interprétations antérieures.This study refers the western part of the « Gers département » in which occurs the Adour valley and its tributaries (Izaute, Midour and Douze) and the Gelise valley. A geological study was carried out from 2010 to 2012.. It allowed us to collect 290 alluvial siliceous pebbles from the Plio-Pleistocene sediments. At the same time 132 flint artefacts of prehistoric sources (Upper Paleolithic) were collected. Petrographic, sedimentological and paleontological studies were carried out. They allow us to distinguish 19 lithological types :- 1 related to the Cenozoic formation ;- 2 associated with Flysch deposits from the the Pyrenean orogenic belt ;- 10 attributed to Senonian age ;- 6 imputed to Maastrichtian with Lepidorbitoides.After that these types were brought together into six sections which show their stratigraphic positions and their paleogeographical environments.- 0,2 % of the alluvial pebbles were related to the Pyrenean Flysch ;- 45 % were of Uppermost Maastrichtian age (Lepidorbitoides ) ;- 54 % were of Senonian age (Coniacian to Middle Maastrichtian).On the other hand, the artefacts collected show a very similar proportions of siliceous pebbles (49 % of Maastrichtian with Lepidorbitoides).The result of this study is that, up to now, the western part of the Lannemezan Plateau includes alluvial areas of Plio-Pleistocene age, containing a large amount of flint pebbles of Upper Cretaceous age. Gathering of this siliceous raw material by palaeolithic communities is obvious.It is also patent that to find out a new lithic raw material located in the southern Aquitaine will be to be retained into account, while former interpretations have to be amended

Entre l’Adour et la Baïse (partie occidentale du département du Gers, France) : une importante source de matières premières siliceuses du Sénonien

La région étudiée correspond à la partie occidentale du département du Gers. Elle couvre une partie de la vallée de l’Adour, de ses affluents (Izaute, Midour, Douze) et de la vallée de la Gélise. Une étude géologique et une collecte de 290 galets alluviaux provenant des formations plio-quaternaires et couvrant les parties sommitales de cette région ont été réalisées de 2010 à 2012. Parallèlement, l’examen de 132 artefacts de gisements gersois attribuables au Paléolithique supérieur a été mené. Les matériaux recueillis ont été soumis à des analyses pétrographiques, sédimentologiques et paléontologiques. Elles ont conduit à discerner 19 types lithologiques qui ont été caractérisés :- un seul type est attribuable au Cénozoïque ;- deux types sont caractéristiques des formations du Flysch pyrénéen ;- dix types paraissent attribuables au Sénonien (du Coniacien au Campanien) ;- six types contiennent une microfaune du Maastrichtien supérieur à Lepidorbitoides.Ces types ont été regroupés en six groupes qui mettent en valeur les niveaux stratigraphiques et les environnements paléogéographiques des différentes époques. Il en est ressorti que seulement 0,2 % des galets alluvionnaires proviennent des formations crétacées du Flysch pyrénéen, 45 % sont issus du Maastrichtien supérieur à Lepidorbitoides, et 54 % du Sénonien (Coniacien à Campanien). Les artefacts en silex collectés dans la même région donnent des résultats très comparables (49 % de Maastrichtien).En conclusion, on peut retenir, à ce jour, que cette partie du plateau du Lannemezan présente des zones alluvionnaires du Plio-Pleistocène qui montrent une forte teneur en galets de silex pour lesquels nous avons établi une origine géologique sénonienne et maastrichtienne. L’utilisation de ces matériaux lithiques au Paléolithique supérieur est évidente.La mise en évidence d’une nouvelle source de matières premières dans la partie méridionale du bassin d’Aquitaine sera à prendre en compte et remet sans doute en question nombre d’interprétations antérieures.This study refers the western part of the « Gers département » in which occurs the Adour valley and its tributaries (Izaute, Midour and Douze) and the Gelise valley. A geological study was carried out from 2010 to 2012.. It allowed us to collect 290 alluvial siliceous pebbles from the Plio-Pleistocene sediments. At the same time 132 flint artefacts of prehistoric sources (Upper Paleolithic) were collected. Petrographic, sedimentological and paleontological studies were carried out. They allow us to distinguish 19 lithological types :- 1 related to the Cenozoic formation ;- 2 associated with Flysch deposits from the the Pyrenean orogenic belt ;- 10 attributed to Senonian age ;- 6 imputed to Maastrichtian with Lepidorbitoides.After that these types were brought together into six sections which show their stratigraphic positions and their paleogeographical environments.- 0,2 % of the alluvial pebbles were related to the Pyrenean Flysch ;- 45 % were of Uppermost Maastrichtian age (Lepidorbitoides ) ;- 54 % were of Senonian age (Coniacian to Middle Maastrichtian).On the other hand, the artefacts collected show a very similar proportions of siliceous pebbles (49 % of Maastrichtian with Lepidorbitoides).The result of this study is that, up to now, the western part of the Lannemezan Plateau includes alluvial areas of Plio-Pleistocene age, containing a large amount of flint pebbles of Upper Cretaceous age. Gathering of this siliceous raw material by palaeolithic communities is obvious.It is also patent that to find out a new lithic raw material located in the southern Aquitaine will be to be retained into account, while former interpretations have to be amended

From the Adour valley to the Gelise valley (western part of the Gers department): an important occurrence of siliceous raw material of Senonian origin.

This study refers the western part of the “Gers department” which covers the Adour valley, its tributaries (Izaute, Midour and Douze) and the Gélise valley. A geological study was carried out from 2010 to 2012. It allowed us to collect 290 alluvial siliceous pebbles from the Plio-Pleistocene sediments. At the same time, 132 flint artefacts from prehistoric sources in the Gers (Upper Palaeolithic) were collected. Petrographic, sedimentological and palaeontological studies were carried out. They allowed us to distinguish 19 lithological types:- 1 related to the Cenozoic formation;- 2 associated with Flysch deposits from the Pyrenean orogenic belt;- 10 attributed to the Senonian age (from the Coniacian to the Campanian);- 6 imputed to the Upper Maastrichtian with Lepidorbitoides.Then these types were brought together into six groups that show their stratigraphic positions and their palaeogeographic environments at different time periods.- 0.2 % of the alluvial pebbles were related to the Pyrenean Flysch;- 45 % were of Upper Maastrichtian age (Lepidorbitoides);- 54 % were of Senonian age (Coniacian to Middle Maastrichtian).The artefacts collected in the same region show a very similar proportion of siliceous pebbles (49 % of Maastrichtian with Lepidorbitoides).The result of this study is that, up to now, the western part of the Lannemezan Plateau includes alluvial areas of Plio-Pleistocene age, containing a large amount of flint pebbles of Upper Cretaceous age (Senonian and Maastrichtian). The gathering of this siliceous raw material by Palaeolithic communities is obvious. The identification of a new lithic raw material located in the southern Aquitaine Basin will have to be taken into account, while former interpretations probably have to be amended

The Blood of Healthy Individuals Exhibits CD8 T Cells with a Highly Altered TCR Vb Repertoire but with an Unmodified Phenotype

CD8 T cell clonal expansions (TCE) have been observed in elderly, healthy individuals as well in old mice, and have been associated with the ageing process. Both chronic latent and non-persistent viral infections have been proposed to drive the development of distinct non-functional and functional TCE respectively. Biases in TCR Vβ repertoire diversity are also recurrently observed in patients that have undergone strong immune challenge, and are preferentially observed in the CD8 compartment. Healthy adults can also exhibit CD8 T cells with strong alterations of their CDR3 length distribution. Surprisingly, no specific investigations have been conducted to analyze the CD8 T cell repertoire in normal adults, to determine if such alterations in TCR Vβ repertoire share the features of TCE. In this study, we characterized the phenotype and function of the CD8 population in healthy individuals of 25–52 years of age. All but one of the EBV-positive HLA-B8 healthy volunteers that were studied were CMV-negative. Using a specific unsupervised statistical method, we identified Vβ families with altered CDR3 length distribution and increased TCR Vβ/HPRT transcript ratios in all individuals tested. The increase in TCR Vβ/HPRT transcript ratio was more frequently associated with an increase in the percentage of the corresponding Vβ+ T cells than with an absence of modification of their percentage. However, in contrast with the previously described TCE, these CD8+ T cells were not preferentially found in the memory CD8 subset, they exhibited normal effector functions (cytokine secretion and cytotoxic molecule expression) and they were not reactive to a pool of EBV/CMV/Flu virus peptides. Taken together, the combined analysis of transcripts and proteins of the TCR Vβ repertoire led to the identification of different types of CD8+ T cell clone expansion or contraction in healthy individuals, a situation that appears more complex than previously described in aged individuals

A map and a database for flint-bearing formations in Southern France: A tool for Petroarchaeology

Une carte des principales formations à silex du sud de la France est en cours de réalisation. Elle propose, à tous les préhistoriens, une base nécessaire au développement d’études interrégionales sur la circulation des silex. Elle est le fruit d’une collaboration entre des acteurs impliqués dans la problématique de caractérisation de la provenance des silex. Elle regroupe les résultats de leurs prospections systématiques ou ciblées dans six régions (Aquitaine, Auvergne, Languedoc-Roussillon, Midi-Pyrénées, Provence-Alpes-Côte-d’Azur, Rhône-Alpes). Elle intègre, en plus, le dépouillement d’un grand nombre de documents : i) les principaux articles et thèses traitant des formations à silex du sud de la France ; ii) plus de 200 fiches issues de la base de données du sous-sol BSS du BRGM, qui permettent de visualiser des logs ou des documents scannés ; iii) 529 cartes géologiques à 1/50 000 et leurs notices. La carte est organisée en trois couches de données superposables : une carte des affleurements ou gîtes primaires, une carte des altérites et des formations superficielles remaniées et une carte des formations alluviales. La carte existera dans deux versions numériques aisément actualisables : une version dans un format PDF et une version sous la forme d’un SIG. C’est l’ensemble de la formation contenant le ou les même(s) type(s) de silex qui est prise en compte, le terme de formation désignant un terrain possédant des caractères communs et qui constitue un ensemble cartographiable. Chacune des formations recensées fait l’objet d’une notice simplifiée qui décrit l’encaissant et - le ou les - type(s) de silex présent(s). Ces notices descriptives et explicatives contiennent des photos à toutes les échelles (de la formation à l’échelle microscopique). Des références bibliographiques géologiques et archéologiques complèteront chaque notice. La version définitive de ces notices constituera un atlas. Les archéologues et géologues disposeront ainsi de fiches descriptives pour chaque type de silex et son encaissant. Elles serviront aux diagnoses analytiques (structures, textures et compositions minéralogiques).A map of the main flint bearing formations in the South of France is under construction. It will provide an essential basis to develop interregional studies about flint procurements and travels. It results from collaboration between actors involved in topic flint sourcing. It includes results of their systematic surveys and studies in six regions (Aquitaine, Auvergne, Languedoc-Roussillon, Midi-Pyrenees, Provence-Alpes - Côte d’Azur, Rhône-Alpes). Moreover, it includes a large number of associated data : i) The main papers and those dealing with flint bearing formations of southern France, ii) more than 200 records from the under-soil database BSS BRGM, which give access to logs or scanned documents iii) 529 geological maps at 1/50 000 and their leaflets. The map is organized in three superimposed layers : a map of outcrops or primary deposits, a map of surficial weathered formation and a revised map of alluvial formations. The map is available in two versions which are easily updatable : a PDF version and an interactive GIS version. In this document, every formation containing the same type (s) (s) of flint is taken into account and forms a mappable entity. Every listed formation is linked to a text which describes the parent rock and/or the type(s) of flint(s). These records contain descriptive and explanatory pictures at different scale (naked eye to microscopic scale). Geological and archaeological references complement every record. The final version will constitute an atlas. Archaeologists and geologists will find description sheets of every type of flint and bearing rock. They will help for analytical diagnoses (structure, texture and mineralogical composition)

The Involvement of SMILE/TMTC3 in Endoplasmic Reticulum Stress Response

The state of operational tolerance has been detected sporadically in some renal transplanted patients that stopped immunosuppressive drugs, demonstrating that allograft tolerance might exist in humans. Several years ago, a study by Brouard et al. identified a molecular signature of several genes that were significantly differentially expressed in the blood of such patients compared with patients with other clinical situations. The aim of the present study is to analyze the role of one of these molecules over-expressed in the blood of operationally tolerant patients, SMILE or TMTC3, a protein whose function is still unknown.We first confirmed that SMILE mRNA is differentially expressed in the blood of operationally tolerant patients with drug-free long term graft function compared to stable and rejecting patients. Using a yeast two-hybrid approach and a colocalization study by confocal microscopy we furthermore report an interaction of SMILE with PDIA3, a molecule resident in the endoplasmic reticulum (ER). In accordance with this observation, SMILE silencing in HeLa cells correlated with the modulation of several transcripts involved in proteolysis and a decrease in proteasome activity. Finally, SMILE silencing increased HeLa cell sensitivity to the proteasome inhibitor Bortezomib, a drug that induces ER stress via protein overload, and increased transcript expression of a stress response protein, XBP-1, in HeLa cells and keratinocytes.In this study we showed that SMILE is involved in the endoplasmic reticulum stress response, by modulating proteasome activity and XBP-1 transcript expression. This function of SMILE may influence immune cell behavior in the context of transplantation, and the analysis of endoplasmic reticulum stress in transplantation may reveal new pathways of regulation in long-term graft acceptance thereby increasing our understanding of tolerance

Incidence of Sarcoma Histotypes and Molecular Subtypes in a Prospective Epidemiological Study with Central Pathology Review and Molecular Testing

International audienceBACKGROUND: The exact overall incidence of sarcoma and sarcoma subtypes is not known. The objective of the present population-based study was to determine this incidence in a European region (Rhone-Alpes) of six million inhabitants, based on a central pathological review of the cases. METHODOLOGY/PRINCIPAL FINDINGS: From March 2005 to February 2007, pathology reports and tumor blocks were prospectively collected from the 158 pathologists of the Rhone-Alpes region. All diagnosed or suspected cases of sarcoma were collected, reviewed centrally, examined for molecular alterations and classified according to the 2002 World Health Organization classification. Of the 1287 patients screened during the study period, 748 met the criteria for inclusion in the study. The overall crude and world age-standardized incidence rates were respectively 6.2 and 4.8 per 100,000/year. Incidence rates for soft tissue, visceral and bone sarcomas were respectively 3.6, 2.0 and 0.6 per 100,000. The most frequent histological subtypes were gastrointestinal stromal tumor (18%; 1.1/100,000), unclassified sarcoma (16%; 1/100,000), liposarcoma (15%; 0.9/100,000) and leiomyosarcoma (11%; 0.7/100,000). CONCLUSIONS/SIGNIFICANCE: The observed incidence of sarcomas was higher than expected. This study is the first detailed investigation of the crude incidence of histological and molecular subtypes of sarcomas