407 research outputs found

    On lower ramification subgroups and canonical subgroups

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    Let p be a rational prime, k be a perfect field of characteristic p and K be a finite totally ramified extension of the fraction field of the Witt ring of k. Let G be a finite flat commutative group scheme over O_K killed by some p-power. In this paper, we prove a description of ramification subgroups of G via the Breuil-Kisin classification, generalizing the author's previous result on the case where G is killed by p>2. As an application, we also prove that the higher canonical subgroup of a level n truncated Barsotti-Tate group G over O_K coincides with lower ramification subgroups of G if the Hodge height of G is less than (p-1)/p^n.Comment: 23 pages; Theorem 1.3 adde

    Dieudonne crystals and Wach modules for p-divisible fgroups

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    Let kk be a perfect field of characteristic p>2p>2 and KK an extension of F=FracW(k)F=\mathrm{Frac} W(k) contained in some F(μpr)F(\mu_{p^r}). Using crystalline Dieudonn\'e theory, we provide a classification of pp-divisible groups over OK\mathscr{O}_K in terms of finite height (φ,Γ)(\varphi,\Gamma)-modules over S:=W(k)[[u]]\mathfrak{S}:=W(k)[[u]]. Although such a classification is a consequence of (a special case of) the theory of Kisin--Ren, our construction gives an independent proof and allows us to recover the Dieudonn\'e crystal of a pp-divisible group from the Wach module associated to its Tate module by Berger--Breuil or by Kisin--Ren

    Analyse p-adique et complétés unitaires universels pour GL (F)

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    Soit p un nombre premier. Les résultats de cette thèse s'inscrivent dans le cadre du programme de Langlands p-adique. Lorsque V est une représentation p-adique de dimension 2 du groupe Gal(\bar{Qp}/Qp), on sait lui associer une représentation p-adique continue B(V) de GL (Qp). Si F est une extension finie non triviale de Qp, la question d'associer des représentations p-adiques de GL (F) aux représentations p-adiques de dimension 2 de Gal(\bar{Qp}/F) dans l'esprit d'une correspondance locale à la Langlands s'annonce beaucoup plus délicate. Dans ce texte, nous considérons des espaces de Banach p-adiques, munis d'une action linéaire continue de GL (F), qui sont des complétions unitaires universelles de certaines représentations localement Qp-analytiques de GL (F). Celles-ci sont susceptibles de jouer un rôle important dans une éventuelle correspondance de Langlands locale p-adique pour GL (F). Le résultat principal de cette thèse est démontré dans le Chapitre 3 et généralise des résultats antérieurs de Berger et Breuil. Il consiste en une description explicite de ces complétés unitaires universels à l'aide des fonctions continues sur F d'un certain type. Pour ce faire, nous introduisons dans le Chapitre 2 des espaces de Banach de fonctions de classe C^r, où r est un nombre rationnel positif, et leurs espaces duaux de distributions d'ordre r. Nous construisons une base de Banach et nous donnons un critère de prolongement des formes linéaires définies sur un espace de fonctions localement Qp-polynomiales en distributions d'ordre r. Ce faisant, nous généralisons des résultats classiques dus à Amice-Vélu et Vishik. Dans le Chapitre 4, nous exhibons des cas de non nullité pour les complétions unitaires universelles considérées par construction explicite de réseaux invariants. Cela donne de nouveaux cas de la conjecture proposée par Breuil et Schneider sur l'équivalence entre l'existence de normes invariantes sur certaines représentations localement algébriques de GL_d(F) et l'existence de certaines représentations de de Rham de Gal(\bar{Qp}/F).Let p be a prime. The subject of this thesis is the p-adic Langlands correspondence. If V is a p-adic representation of dimension 2 of the group Gal(\bar{Qp}/Qp), it is known how to associate to it a continuous p-adic representation B(V) of GL (Qp). If F is a non-trivial finite extension of Qp, the issue of associating p-adic representations of GL (F) to p-adic representations of dimension 2 of Gal(\bar{Qp}/F) in the spirit of a local Langlands correspondence appears much more delicate. In this text we consider a class of p-adic Banach spaces, endowed with a continuous linear action of GL (F), which are obtained as universal unitary completions of certain locally Qp-analytic representations of GL (F). Such representations are likely to play an important role in a future local p-adic Langlands correspondence for GL (F). The main result of this thesis is proved in Chapter 3 and generalizes some previous results of Berger and Breuil. It consists in an explicit description of these universal unitary completions by means of a certain class of continuous functions on F. In order to do this, we introduce in Chapter 2 a class of Banach spaces of functions of class C^r, where r is a positive rational number, as well as their dual spaces of distributions of order r. We build a Banach base and we give a criterion for telling when a linear form defined on a space of locally Qp-polynomial functions extends to a distribution of order r. As a consequence, we generalize some classical results due to Amice-Vélu and Vishik. In Chapter 4 we exhibit cases of non-nullity for these universal unitary completions, by an explicit construction of invariant lattices. This also provides new instances of the Breuil-Schneider conjecture about the equivalence between the existence of invariant norms on certain locally algebraic representations of GL_d(F) and the existence of certain De Rham representations of Gal(\bar{Qp}/F).PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

    A micro gas preconcentrator with improved performance for pollution monitoring and explosives detection

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    International audienceThis paper presents the optimization of a micro gas preconcentrator based on a micro-channel in porous and non-porous silicon filled with an adequate adsorbent. This micro gas preconcentrator is both applicable in the fields of atmospheric pollution monitoring (Volatil organic compounds—VOCs) and explosives detection (nitroaromatic compounds). Different designs of micro-devices and adsorbent materials have been investigated since these two parameters are of importance in the performances of the micro-device. The optimization of the device and its operation were driven by its future application in outdoor environments. Parameters such as the preconcentration factor, cycle time and the influence of the humidity were considered along the optimization process. As a result of this study, a preconcentrator with a total cycle time of 10 min and the use of single wall carbon nanotubes (SWCNTs) as adsorbent exhibits a good preconcentration factor for VOCs with a limited influence of the humidity. The benefits of using porous silicon to modify the gas desorption kinetics are also investigated

    Micro gas preconcentrator in porous silicon filled with a carbon absorbent

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    International audienceThis paper presents the development of a gas preconcentrator based on a micro-channel in porous silicon filled with carbon nanopowders by a micro-fluidic process. The particularity of this device is its applicability in the fields of atmospheric pollution monitoring by targeting VOCS (volatiles organic compounds). Various designs of micro-devices have been investigated and a special focus has been dedicated to the carbon adsorbent. The optimization of the device and its operation were driven by its future application in outdoor environments. The benefits of using porous silicon to ease the fixing of the carbon absorbent in micro-channels and to modify the gas desorption kinetic are also investigated. Results on a device based on a carbon adsorbent powder filled in a porous silicon micro-channel for benzene preconcentration are reported

    Análisis filogenético de aislamientos de Groundnut ringspot virus desde maní e identificación de posibles trips vectores asociados al cultivo de maní en la Argentina

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    Groundnut ringspot virus (GRSV), genus Tospovirus, is a thrips-transmitted virus infecting peanuts (Arachis hypogaea L.) in Córdoba province, Argentina. Fourteen viral isolates were recovered from Tospovirus-like symptomatic plants from different peanut fields. Viral isolates as GRSV were identified by serological and molecular tests. Nucleotide and derived amino acid sequence analyses of the nucleocapsid (N) gene indicated a high degree of identity between the GRSV peanut isolates, indicating that there is no molecular variability in the N gene of the GRSV that infects peanuts in the cropping area of Córdoba. In this study, we determined the presence of thrips species in the crop, which can potentially transmit the virus. Thrips were observed in all the evaluated peanut fields. Frankliniella schultzei was the most frequently identified species followed by Caliothrips phaseoli and Frankliniella occidentalis. This work reports the presence of F. schultzei and F. occidentalis in peanuts in Argentina for the first time. These results along with the high degree of similarity between the GRSV peanut isolates suggest that the virus could be transmitted by F. schultzei, which has been cited as its most efficient vector.Groundnut ringspot virus (GRSV, género Tospovirus) es un virus que infecta naturalmente el cultivo de maní (Arachis hypogaea L.) en la región productora de Córdoba, Argentina. En distintas localidades de la provincia, se colectaron 14 aislamientos virales provenientes de maníes que manifestaban síntomas característicos de Tospovirus. Todos los aislamientos virales fueron identificados como GRSV mediante pruebas serológicas y moleculares. El análisis de las secuencias nucleotídicas y de amino ácidos deducidas del gen de la nucleoproteína (N) reveló un alto grado de identidad entre los 14 aislamientos, indicando que no existe variabilidad molecular en el gen N del GRSV que infecta maní en la provincia de Córdoba. En este estudio se determinó la presencia de trips en el cultivo que pueden potencialmente transmitir la enfermedad. Estos insectos fueron observados colonizando maní en todos los lotes evaluados. La especie identificada con mayor frecuencia fue Frankliniella schultzei, seguida de Caliothrips phaseoli y Frankliniella occidentalis. Este es el primer reporte de F. schultzei y F. occidentalis afectando maní en Argentina. Estos resultados, junto con el elevado grado de similitud encontrado entre los distintos aislamientos de GRSV, sugieren que el virus puede ser transmitido por F. schultzei, citado como el vector más eficiente del GRSV

    Elaboración de sondas moleculares para la detección de virus de yerba mate

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    La yerba mate (Ilex paraguariensis A St‐Hil) es un arbusto perenne originario de América del Sur. En Argentina, se evidenciaron plantas de yerba mate con síntomas virales de amarillamiento, clorosis de nervaduras, moteado, anillos y diseños lineales cloróticos. Análisis mediante microscopía electrónica, técnicas moleculares y secuenciación masiva, permitieron identificar los virus Yerba mate chlorosis-associated virus (YmCaV), perteneciente al género Cytorhabdovirus, Yerba mate-associated circular DNA virus (YMaCV), un virus circular de ADN monocatenario, y otro patógeno viral parcialmente secuenciado, posiblemente de la familia Closteroviridae. El objetivo del trabajo fue elaborar sondas moleculares para la identificación masiva de los virus de yerba mate. Se purificaron productos de PCR amplificados con cebadores específicos, diseñados para cada uno de los virus. Los productos aislados se clonaron y secuenciaron para confirmar la identidad del inserto. A partir de los plásmidos seleccionados se sintetizaron ribosondas para la detección de YmCaV y el posible closterovirus, y una sonda de DNA para el virus YMaCV, utilizando los kits ?RNA Labeling and Detection? y ?DIG DNA Labeling and Detection? (Roche), respectivamente. Para el diagnóstico de plantas de yerba mate, se ajustó la técnica dot blot en nitrocelulosa. Las sondas específicas para YmCaV y YMaCV reaccionaron con los testigos positivos de cada virus, mientras que no reaccionaron con los testigos negativos. La sonda para la detección del posible closterovirus sigue en desarrollo. Este trabajo permitió ajustar una técnica para el diagnóstico masivo de los virus YmCaV y YMaCV.Fil: Nome, Claudia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; ArgentinaFil: Bejerman, Nicolas. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; ArgentinaFil: de Breuil, Soledad. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; Argentina5to Congreso Argentino de Fitopatología y 59º Reunión APS División CaribeArgentinaAsociación Argentina de Fitopatólogo

    Universal deformation rings for the symmetric group S_4

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    Let k be an algebraically closed field of characteristic 2, and let W be the ring of infinite Witt vectors over k. Let S_4 denote the symmetric group on 4 letters. We determine the universal deformation ring R(S_4,V) for every kS_4-module V which has stable endomorphism ring k and show that R(S_4,V) is isomorphic to either k, or W[t]/(t^2,2t), or the group ring W[Z/2]. This gives a positive answer in this case to a question raised by the first author and Chinburg whether the universal deformation ring of a representation of a finite group with stable endomorphism ring k is always isomorphic to a subquotient ring of the group ring over W of a defect group of the modular block associated to the representation.Comment: 12 pages, 2 figure

    Period Spaces for Hodge Structures in Equal Characteristic

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    We develop the analog in equal positive characteristic of Fontaine's theory for crystalline Galois representations of a p-adic field. In particular we describe the analog of Fontaine's functor which assigns to a crystalline Galois representation an isocrystal with a Hodge filtration. In equal characteristic the role of isocrystals and Hodge filtrations is played by z-isocrystals and Hodge-Pink structures. The latter were invented by Pink. Our first main result in this article is the analog of the Colmez-Fontaine Theorem that "weakly admissible implies admissible". Next we construct period spaces for Hodge-Pink structures on a fixed z-isocrystal. These period spaces are analogs of the Rapoport-Zink period spaces for Fontaine's filtered isocrystals in mixed characteristic and likewise are rigid analytic spaces. For our period spaces we prove the analog of a conjecture of Rapoport and Zink stating the existence of a "universal local system" on a Berkovich open subspace of the period space. As a consequence of "weakly admissible implies admissible" this Berkovich open subspace contains every classical rigid analytic point of the period space. As the principal tool to demonstrate these results we use the analog of Kedlaya's Slope Filtration Theorem which we also formulate and prove here.Comment: v3: final version, appears in Annals of Mathematic

    Production of polyclonal antiserum for the detection of cymbidium mosaic virus and odontoglossum ringspot virus in orchids.

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    Las orquídeas (familia Orchidaceae) son susceptibles a diversos factores bióticos y abióticos que afectan su desarrollo y calidad. Entre ellos, Cymbidium mosaic virus (CymMV) y Odontoglossum ringspot virus (ORSV) son los patógenos más frecuentes y de mayor importancia económica a nivel mundial. La transmisión mecánica de estos virus y la multiplicación principalmente agámica de las orquídeas hacen necesario contar con material madre libre de virus. El objetivo de este trabajo fue elaborar reactivos de diagnóstico para la detección de CymMV y ORSV. Se elaboró un antisuero policlonal contra CymMV+ORSV que se tituló 1:10000 mediante NC-ELISA. El antisuero fue procesado y se obtuvieron IgG e IgG-conjugada anti CymMV+ORSV dilución 1:500 para su utilización en DAS-ELISA. La capacidad inmunodiagnóstica de esta técnica se evaluó mediante el análisis de muestras provenientes de orquídeas con síntomas característicos de infección viral, recolectadas en viveros comerciales de la ciudad de Córdoba, Argentina. La presencia de virosis se detectó en el 22 % de las muestras estudiadas y en el 75 % de los establecimientos relevados. La capacidad de estos reactivos para identificar CymMV, ORSV e infecciones mixtas en orquídeas permitirá agilizar y economizar los análisis. Esto representaría una ventaja para las detecciones a gran escala.Orchids (family Orchidaceae) are susceptible to several biotic and abiotic factors that affect their development and quality. Among them, Cymbidium mosaic virus (CymMV) and Odontoglossum ringspot virus (ORSV) are the most frequent pathogens, with the greatest economic impact worldwide. The mechanical transmission of these viruses in addition to the predominantly agamic multiplication of orchids, make it necessary to work with virus-free plant material. The objective of this work was to develop diagnostic reagents for the detection of CymMV and ORSV. A polyclonal antiserum against CymMV + ORSV was made with a titer of 1:10000 determined by NC-ELISA. The antiserum was processed generating IgG and IgG-conjugated” anti CymMV+ORSV were obtained for use in DAS-ELISA in a dilution of 1:500. The immunodiagnostic capacity of this technique was evaluated by analyzing samples from orchids with characteristic viral symptoms, collected from commercial nurseries in the city of Córdoba, Argentina. Viral infections were detected in 22 % of the samples analyzed and in 75 % of the nurseries surveyed. The ability of these reagents to identify CymMV, ORSV and mixed infections in orchids, will speed up analyzes and reduce their costs. This would represent an advantage for large-scale detections.Fil: Dottori, Carolina Andrea. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: de Breuil, Soledad. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; ArgentinaFil: Tuma Borgonovo, Maria Alejandra. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Nome, Sergio Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; Argentin
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