341 research outputs found

    Le Cénozoïque du bassin de Paris : un enregistrement sédimentaire haute résolution des déformations lithosphériques en régime de faible subsidence

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    International audienceLe bassin de Paris est considĂ©rĂ© comme un exemple typique de bassin intracratonique affectĂ© par une subsidence thermique long terme. Le CĂ©nozoĂŻque correspond Ă  une pĂ©riode de faible subsidence (Ă©paisseurs infĂ©rieures Ă  350m) et marque la fin du fonctionnement de ce bassin. C’est en outre une pĂ©riode de forte dĂ©formation de la plaque europĂ©enne, dans un contexte de convergence Afrique-Eurasie et d’ouverture de l'Atlantique Nord caractĂ©risĂ©e par des inversions de grabens dans le Nord et l’Est de l’Europe. Si de nombreux hiatus ont Ă©tĂ© identifiĂ©s, les dĂ©formations cĂ©nozoĂŻques du bassin de Paris, situĂ©es sur une croute Ă  l’équilibre et leur relation aux contraintes en limite de plaque restent mĂ©connues. Cette thĂšse a pour objectif de recomposer Ă  haute rĂ©solution spatiale et temporelle (de l’ordre du million d’annĂ©es) les gĂ©omĂ©tries sĂ©dimentaires 3D et les palĂ©ogĂ©ographies successives du PalĂ©ocĂšne au dĂ©but de l’OligocĂšne. Ce travail qui s’appuie sur de nombreuses donnĂ©es biostratigraphiques consiste en une approche couplĂ©e de sĂ©dimentologie de faciĂšs et de corrĂ©lations diagraphiques (500 puits) selon les principes de la stratigraphie sĂ©quentielle. Trois ordres de sĂ©quences sont dĂ©finis. Les cycles d’ordre supĂ©rieur (4Ăšme et 3Ăšme ordre) enregistrent les variations climato-eustatiques. Cinq sĂ©quences de dĂ©pĂŽt (2e ordre), limitĂ©es par des discontinuitĂ©s et/ou des rĂ©organisations palĂ©ogĂ©ographiques sont identifiĂ©es : (1) Maastrichtien-Danien ; (2) ThanĂ©tien-YprĂ©sien ; (3) LutĂ©tien-Bartonien ; (4) Bartonien-Priabonien terminal et (5) Priabonien terminal-Chattien. Les architectures des sĂ©quences (1) Ă  (4) sont contrĂŽlĂ©es par des phases de flexures. AprĂšs des Ă©mersions lors des paroxysmes de flexuration, la relaxation progressive des flexures se traduit tout d’abord par la mise en place de profils pentĂ©s et ouverts, puis par des profils de plus en plus plats et confinĂ©s associĂ©s Ă  une transgression gĂ©nĂ©ralisĂ©e. Du ThanĂ©tien au Bartonien s’observent des flexures d’axe E-W, dont les Ăąges sont compatibles avec les diffĂ©rentes phases de la convergence IbĂ©rie-Eurasie. En outre, une dĂ©formation de courte durĂ©e Ă  l’YprĂ©sien basal est rattachĂ©e Ă  l'ouverture de l'Atlantique Nord. Enfin, une rĂ©orientation majeure du bassin possiblement liĂ©e au dĂ©but de la collision Apulie-Eurasie est observĂ©e au Priabonien. Ce travail fournit un calage Ă  haute rĂ©solution pour la comprĂ©hension et la modĂ©lisation des dĂ©formations intraplaques. DiffĂ©rentes tailles de flexure, de l’ordre de 150 Ă  plus 300 km sont observĂ©es traduisant une implication d’épaisseurs plus ou moins importantes de la lithosphĂšre

    Satellite DNA as a target for TaqMan real-time PCR detection of the pinewood nematode, Bursaphelenchus xylophilus

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    The pinewood nematode (PWN), Bursaphelenchus xylophilus , is a major pathogen of conifers, which impacts on forest health, natural ecosystem stability and international trade. As a consequence, it has been listed as a quarantine organism in Europe. A real-time PCR approach based on TaqMan chemistry was developed to detect this organism. Specific probe and primers were designed based on the sequence of the Msp I satellite DNA family previously characterized in the genome of the nematode. The method proved to be specific in tests with target DNA from PWN isolates from worldwide origin. From a practical point of view, detection limit was 1 pg of target DNA or one individual nematode. In addition, PWN genomic DNA or single individuals were positively detected in mixed samples in which B. xylophilius was associated with the closely related non-pathogenic species B. mucronatus , up to the limit of 0.01% or 1% of the mixture, respectively. The real-time PCR assay was also used in conjunction with a simple DNA extraction method to detect PWN directly in artificially infested wood samples. These results demonstrate the potential of this assay to provide rapid, accurate and sensitive molecular identification of the PWN in relation to pest risk assessment in the field and quarantine regulation

    The use of Copernicus Marine Service products to describe the state of the Tropical Western Pacific Ocean around the Islands: a case study

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    Fiji served as President of the UN General Assembly in 2017, linking climate (SDG13) and ocean (SDG14) as the foundation of blue economies for island and coastal states around the world. The resulting United Nations Oceans outcome statement stressed “the importance of enhancing understanding of the health and role of our ocean and the stressors on its ecosystems, including through assessments on the state of the ocean, based on science and on traditional knowledge systems. We also stress the need to further increase marine scientific research to inform and support decision-making, and to promote knowledge hubs and networks to enhance the sharing of scientific data, best practices and ‘know-how.’” (UN, 2017). The Copernicus Marine Service Atlas for the Pacific Ocean States goes beyond the unique compilation of CMIP3 climate model projections and data tools compiled by the Pacific Climate Change Science Program (PCCSP, 2011, 2014). A complete overview of tropical Pacific observing network is available in the WMO publication library (GCOS, 2014a, 2014b). Our study focuses on the application of the available CMEMS products to the Pacific domain defined by PCCSP. As president of COP23, Prime Minister Frank Bainimarama has emphasized the importance of the climate and ocean connection and the need to protect ocean health to protect the planet: ‘We are all in the same canoe’ (https://cop23.com.fj/fijian-prime-minister-cop23-president-remarks-assuming-presidency-cop23/). The Copernicus Marine Service Atlas for Pacific Ocean States compiled by the author team responds directly to Fiji’s requests at the 2017 United Nation Oceans for SDG 14, life below water and the 2017 COP23 for SDG13, climate action which goes beyond the Pacific

    Evaluation de L’efficacite et de L’acceptabilite de la Prise en Charge Ambulatoire de la Malnutrition Aigue Chez les Enfants Vivants Avec le Vih (Evvih) Au Centre Hospitalier Regional De Ziguinchor (Chrz)/ Senegal

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    Objectif : La malnutrition aigĂŒe est frĂ©quente chez les enfants infectĂ©s par le VIH. L’objectif de notre travail Ă©tait d’évaluer l’efficacitĂ© et l’acceptabilitĂ© des protocoles de rĂ©cupĂ©ration nutritionnelle ambulatoire basĂ©s sur les aliments prĂȘts Ă  l’emploi (ATPE) chez les EVVIH. MatĂ©riel et mĂ©thodes : Il s’agissait d’une Ă©tude prospective, rĂ©alisĂ©e Ă  la pĂ©diatrie du CHRZ du 7 janvier au 31 Septembre 2018. Ont Ă©tĂ© inclus les EVVIH, ĂągĂ©s de 6 mois Ă  19 ans prĂ©sentant une malnutrition aigĂŒe modĂ©rĂ©e ou sĂ©vĂšre sans complication. Le suivi Ă©tait bimensuel jusqu’à l’atteinte du poids cible. Un bilan clinico-biologique et anthropomĂ©trique, la dĂ©livrance des ATPE et la mesure de l’observance aux prescriptions Ă©taient rĂ©alisĂ©s. RĂ©sultats : Douze enfants vivants avec le VIH ont Ă©tĂ© inclus dont 3 MAS et 9 MAM sur un total de 25 enfants suivis soit une prĂ©valence de 48%. Le sexe ratio (1,4) en faveur des garçons. L’ñge mĂ©dian (9,5 ans). Ils Ă©taient sous ARV dans 92% des cas. La moitiĂ© des patients avait un Ăąge > Ă  10 ans. La toux Ă©tait le symptĂŽme le plus retrouvĂ© (67%) suivie de la diarrhĂ©e (58,3%), des vomissements (8,3%), une otite moyenne chronique (8,3%). La charge virale au dĂ©but de l'Ă©tude a montrĂ© (5cas < 50 copies, 3cas < 5000 copies, 4cas > 15 000 copies). Le taux d'hĂ©moglobine Ă©tait < 10g/dl dans 92% des cas. Un problĂšme d'observance de la prise d'ATPE a Ă©tĂ© notĂ© dans 58,3%. Onze enfants ont atteint leur poids cible. Nous n’avons pas notĂ© de perdu de vu ni d’hospitalisĂ©. Conclusion : Les ATPE bien que efficaces, pausent souvent un problĂšme d’acceptabilitĂ©. On gagnerait Ă  amĂ©liorer le gout et la prĂ©sentation pour permettre une meilleure observance. Objective: Acute malnutrition is common in children with HIV infection. The objective of our work was to evaluate the efficiency and acceptability of ambulatory nutritional recovery protocols (ATPE) based on ready-to-use food) in HIV-positive children (EVVIH). Methods: This was a prospective study, conducted at the pediatrics of the regional hospital center of Ziguinchor (CHRZ) from January 7th to September 31st, 2018. We included all HIV-positive children (EVVIH), aged between 6 months and 19 years with relatively acute or severe malnutrition without complication. The follow-up was done every two months until target weight was reached. A clinic-biological and anthropometric report, the issuing of ATPE and the measurement of compliance with prescriptions were carried out. Results: We chose 12 children living with HIV, including 3 MAS and 9 MAM out of a total of 25 children followed, with a prevalence of 48%. The sex ratio (1.4) was in favor of boys. The medium age was (9.5 years). They were under ARV in 92% of cases. Half of the patients were > 10 years old. Coughing was the most common symptom (67%) followed by diarrhea (58.3%), vomiting (8.3%), medium chronic otitis (8.3%). The viral affection at the beginning of the study showed (5cases <50 copies, 3cases <5000 copies, 4cases> 15,000 copies). The hemoglobin level was <10g / dl in 92% of cases. A problem of respect of ATPE taking was noted in 58.3%. Eleven children reached their target weight. We did not notice any loss ofsight and no child was hospitalized. Conclusion: Although the ATPE are efficient, they often cause a problem of acceptability. It would be better to improve the taste and the presentation to allow a better observance

    InclusiĂłn de GĂ©nero en las PolĂ­ticas de Agricultura, Cambio ClimĂĄtico, Seguridad Alimentaria y NutriciĂłn en Honduras y Guatemala

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    SegĂșn el quinto informe del Panel Intergubernamental de Expertos sobre el Cambio ClimĂĄtico (IPCC, por sus siglas en inglĂ©s), la regiĂłn de Centro AmĂ©rica ha experimentado en los Ășltimos años cambios en la variabilidad climĂĄtica, aumentos en los extremos de temperatura, y en los episodios extremos, hechos que han afectado gravemente a la regiĂłn (Magrin, 2014). Por ejemplo, las temperaturas extremas han aumentado y la duraciĂłn de la canĂ­cula en la regiĂłn se ha incrementado considerablemente, de 2 a 4 meses (PNA, 2018). Las proyecciones climĂĄticas para el año 2100 no son alentadoras, y prevĂ©n mĂĄs aumentos de temperaturas y variabilidad en las precipitaciones (Magrin,2014). Los impactos del cambio climĂĄtico en los sistemas agrĂ­colas productivos estĂĄn afectando gravemente al estado de seguridad alimentaria y nutriciĂłn (SAN) en Guatemala y Honduras (FAO, 2015). Estos impactos, tendrĂĄn tambiĂ©n implicaciones de gĂ©nero, debido a los diferentes roles, dificultades, oportunidades y prioridades que hombres y mujeres, de diferentes edades y origen Ă©tnico, tienen. Por ejemplo, en Centro AmĂ©rica, la desigualdad social, polĂ­tica y econĂłmica se traduce en las mujeres teniendo un menor acceso a la asistencia tĂ©cnica, crĂ©ditos financieros y a la titularidad de la tierra que los hombres, aun con el importante rol que las mujeres juegan en la producciĂłn agrĂ­cola y la seguridad alimentaria y nutriciĂłn de las familias de la regiĂłn (CAC, 2018). Resulta fundamental por lo tanto, que las iniciativas polĂ­ticas diseñadas para la adaptaciĂłn y mitigaciĂłn del cambio climĂĄtico, desarrollen consideraciones explĂ­citas de gĂ©nero para poder contribuir a cerrar las brechas de gĂ©nero existentes en el sector agrĂ­cola

    Nesprins are mechanotransducers that discriminate epithelial-mesenchymal transition programs

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    © 2020 DĂ©jardin et al. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms/). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 International license, as described at https://creativecommons.org/licenses/by-nc-sa/4.0/).LINC complexes are transmembrane protein assemblies that physically connect the nucleoskeleton and cytoskeleton through the nuclear envelope. Dysfunctions of LINC complexes are associated with pathologies such as cancer and muscular disorders. The mechanical roles of LINC complexes are poorly understood. To address this, we used genetically encoded FRET biosensors of molecular tension in a nesprin protein of the LINC complex of fibroblastic and epithelial cells in culture. We exposed cells to mechanical, genetic, and pharmacological perturbations, mimicking a range of physiological and pathological situations. We show that nesprin experiences tension generated by the cytoskeleton and acts as a mechanical sensor of cell packing. Moreover, nesprin discriminates between inductions of partial and complete epithelial-mesenchymal transitions. We identify the implicated mechanisms, which involve α-catenin capture at the nuclear envelope by nesprin upon its relaxation, thereby regulating ÎČ-catenin transcription. Our data thus implicate LINC complex proteins as mechanotransducers that fine-tune ÎČ-catenin signaling in a manner dependent on the epithelial-mesenchymal transition program.This material is based on work supported by the Centre national de la recherche scientifique (CNRS), Agence nationale de la recherche (ANR; grants ANR-13-JSV5-0007 and ANR-14-CE09-0006), France BioImaging (ANR-10-INBS-04), la Ligue contre le Cancer (REMX17751 to P.M. Davidson), and the Fondation ARC pour la Recherche sur le Cancer (PDF20161205227 to P.M. Davidson). P.S. Carollo has received funding from the European Union’s Horizon 2020 Framework Programme for Research and Innovation (Marie SkƂodowska-Curie grant agreement 665850-INSPIRE) and acknowledges the Ecole Doctorale FrontiĂšres de l'Innovation en Recherche et Éducation (FIRE) Programme Bettencourt. E.R. Gomes was supported by a European Research Council consolidator grant (617676).info:eu-repo/semantics/publishedVersio

    Unexplored vegetal green synthesis of silver nanoparticles: A preliminary study with Corchorus olitorus Linn and Ipomea batatas (L.) Lam

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    Antibacterial properties of silver ion are known from ancient times. The plant extract mediated synthesis of nanoparticles is gaining popularity due to green chemistry for the generation of nanosized materials. Corchorus olitorus Linn and Ipomea batatas (L.) Lam are world crops having leaves of high nutritional value. In the present work, Ag and AgCl nanoparticles were synthesized by incubating leaf aqueous extracts with silver nitrate salt, making them to react in the dark. Plasmon resonance bands, studied by ultraviolet spectroscopy, have been obtained. X-ray diffraction (XRD) revealed the average size of pure crystallites composed of Ag and AgCl. Optimization studies for the synthesis process highlight positive impact of pH, reaction time and reactants quantities.Key words: Silver, nanoparticles, Corchorus olitorus, Ipomea batatas, X-ray diffraction

    RODIN project, Topology Optimization 2.0?

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    RODIN project is an attempt to propose a new kind of topology optimization tools. It has been motivated by the combination of two events: (1) the industrials demands for getting past serious limits identified in the available tools, (2) the advent of a new mathematical approach in the mid 2000's presenting very interesting properties. This project has been launched in July 2012 and is supported by French public funding. It is a collaborative project that gathers ten partners (ranging from academics to software editors and industrials end-users) and firmly aims at overcoming technical and scientific locks in the area of topology optimization. RODIN is therefore an ambitious and risky project that will possibly mark the birth of a new numerical tool
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