466 research outputs found

    On peak phenomena for non-commutative H∞H^\infty

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    A non-commutative extension of Amar and Lederer's peak set result is given. As its simple applications it is shown that any non-commutative H∞H^\infty-algebra H∞(M,τ)H^\infty(M,\tau) has unique predual,and moreover some restriction in some of the results of Blecher and Labuschagne are removed, making them hold in full generality.Comment: final version (the presentation of some part is revised and one reference added

    Automatiser la construction de règles de corrélation : prérequis et processus

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    National audienceLes systèmes d'entreprise sont aujourd'hui composés de plusieurs dizaines, centaines ou milliers d'entités communiquant potentiellement avec des machines externes inconnues. Dans ces systèmes de nombreux détecteurs, sondes et IDS sont déployés et inondent les systèmes de supervision de messages et d'alertes. La problématique d'un administrateur en charge de la supervision est alors de détecter des motifs d'attaques contre le système au sein de ce flot de notifications. Pour cela, il dispose d'outils de corrélation permettant d'identifier des scénarios complexes à partir de ces notifications de bas niveau. Cependant, la spécification de ces scénarios demande d'avoir au préalable construit les règles de corrélation adéquates. Ce papier se focalise sur une méthode de génération de règles de corrélation et des prérequis nécessaires à cette opération. Il évalue ensuite le travail requis pour obtenir de telles règles dans le cas d'un processus de génération automatisé

    Reconstrucción paleoclimática y paleoambiental de la Península Ibérica durante el Cuaternario, aplicación de modelos geoprospectivos para la evaluación de escenarios futuros

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    Esta comunicación trata de resumir el trabajo realizado por el ITGE, BRGM, CCMA, IPE, ETSIMM y ENRESA en el proyecto titulado "Paleoclimatological Revision of Climate Evolution and Environment in Western Mediterranean Region. Evaluation of future evolution scenarios in the Iberian Peninsula", en el marco del Programa de la Comisión de las Comunidades Europeas sobre Gestión y Almacenamiento de Residuos Radioactivos (contrato CEC FI2WCT91- 0075)

    On the smoothness of L p of a positive vector measure

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s00605-014-0666-7We investigate natural sufficient conditions for a space L p(m) of pintegrable functions with respect to a positive vector measure to be smooth. Under some assumptions on the representation of the dual space of such a space, we prove that this is the case for instance if the Banach space where the vector measure takes its values is smooth. We give also some examples and show some applications of our results for determining norm attaining elements for operators between two spaces L p(m1) and Lq (m2) of positive vector measures m1 and m2.Professor Agud and professor Sanchez-Perez authors gratefully acknowledge the support of the Ministerio de Economia y Competitividad (Spain), under project #MTM2012-36740-c02-02. Professor Calabuig gratefully acknowledges the support of the Ministerio de Economia y Competitividad (Spain), under project #MTM2011-23164.Agud Albesa, L.; Calabuig Rodriguez, JM.; Sánchez Pérez, EA. (2015). On the smoothness of L p of a positive vector measure. Monatshefte für Mathematik. 178(3):329-343. https://doi.org/10.1007/s00605-014-0666-7S3293431783Beauzamy, B.: Introduction to Banach Spaces and Their Geometry. North-Holland, Amsterdam (1982)Diestel, J., Uhl, J.J.: Vector measures. In: Mathematical Surveys, vol. 15. AMS, Providence (1977)Fernández, A., Mayoral, F., Naranjo, F., Sáez, C., Sánchez-Pérez, E.A.: Spaces of p-integrable functions with respect to a vector measure. Positivity 10, 1–16 (2006)Ferrando, I., Rodríguez, J.: The weak topology on LpL^p L p of a vector measure. Topol. Appl. 155(13), 1439–1444 (2008)Godefroy, G.: Boundaries of a convex set and interpolation sets. Math. Ann. 277(2), 173–184 (1987)Howard, R., Schep, A.R.: Norms of positive operators on LpL^p L p -spaces. Proc. Am. Math. Soc. 109(1), 135–146 (1990)Lindenstrauss, J., Tzafriri, L.: Classical Banach Spaces II. Springer, Berlin (1977)Meyer-Nieberg, P.: Banach Latticces. Universitext, Springer-Verlag, Berlin (1991)Okada, S., Ricker, W.J., Sánchez-Pérez, E.A.: Optimal Domain and Integral Extension of Operators Acting in Function Spaces. Operator Theory: Advances and Applications, vol. 180. Birkhäuser Verlag, Basel (2008)Schep, A.: Products and factors of Banach function spaces. Positivity 14(2), 301–319 (2010

    A remark on totally smooth renormings

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    [EN] E. Oja, T. Viil, andD. Werner showed, in Totally smooth renormings, Archiv der Mathematik, 112, 3, (2019), 269-281, that a weakly compactly generated Banach space ( X, center dot) with the property that every linear functional on X has a unique Hahn-Banach extension to the bidual X ** (the so-called Phelps' property U in X **, also known as the Hahn-Banach smoothness property) can be renormed to have the stronger property that for every subspace Y of X, every linear functional on Y has a unique Hahn-Banach extension to X ** (the so-called total smoothness property of the space). We mention here that this result holds in full generality -without any restriction on the space- and in a stronger form, thanks to a result ofM. Raja, On dual locally uniformly rotund norms, Israel Journal of Mathematics 129 (2002), 77-91.Supported by AEI/FEDER (project MTM2017-83262-C2-2-P of Ministerio de Economia y Competitividad), by Fundacion Seneca, Region de Murcia (Grant 19368/PI/14), and Universitat Politecnica de Valencia (A. J. Guirao). Supported by AEI/FEDER (project MTM2017-83262-C2-1-P of Ministerio de Economia y Competitividad) and Universitat Politecnica de Valencia (V. Montesinos). We thank the referees for their work, that neatly improved the original version of this note to its final form.Cobollo, C.; Guirao Sánchez, AJ.; Montesinos Santalucia, V. (2020). A remark on totally smooth renormings. Revista de la Real Academia de Ciencias Exactas Físicas y Naturales Serie A Matemáticas. 114(2):1-4. https://doi.org/10.1007/s13398-020-00831-5S141142Fabian, M., Habala, P., Hájek, P., Montesinos, V., Zizler, V.: Banach space theory: the basis of linear and nonlinear analysis. Springer, New York (2011)Fabian, M., Montesinos, V., Zizler, V.: Smoothness in Banach spaces. Selected problems. Rev. R. Acad. Cien. Ser. A. Mat. RACSAM. 100(1–2), 101–125 (2006)Ferrari, S., Orihuela, J., Raja, M.: Generalized metric properties of spheres and renorming of Banach spaces. Rev. R. Acad. Cienc. Exactas Fis. Natl. Ser. A Math. RACSAM. 113, 2655–2663 (2019)Foguel, S.R.: On a theorem by A. E. Taylor. Proc. Amer. Math. Soc. 9, 325 (1958)Godefroy, G.: Points de Namioka, espaces normants, applications à la théorie isométrique de la dualité. Israel J. Math. 38, 209–220 (1981)Guirao, A.J., Montesinos, V., Zizler, V.: Open Problems in the geometry and analysis of Banach spaces. Springer International Pub, Switzerland (2016)Harmand, P., Werner, D., Werner, W.: M-ideals in Banach spaces and Banach algebras. Lecture notes in math, vol. 1547. Springer, Berlin (1993)Haydon, R.: Locally uniformly rotund norms in Banach spaces and their duals. J. Funct. Anal. 254, 2023–2039 (2008)Oja, E., Viil, T., Werner, D.: Totally smooth renormings. Archiv. der. Mathematik. 112(3), 269–281 (2019)Phelps, R.R.: Uniqueness of Hahn–Banach extensions and unique best approximation. Trans. Amer. Math. Soc. 95, 238–255 (1960)Raja, M.: On dual locally uniformly rotund norms. Israel J. Math. 129, 77–91 (2002)Smith, R.J., Troyanski, S.L.: Renormings of C(K)C(K) spaces. Rev. R. Acad. Cienc. Exactas Fís. Natl. Ser. A Math. RACSAM 104(2), 375–412 (2010)Sullivan, F.: Geometrical properties determined by the higher duals of a Banach space. Illinois J. Math. 21, 315–331 (1977)Taylor, A.E.: The extension of linear functionals. Duke Math. J. 5, 538–547 (1939

    DC-electric-field-induced and low-frequency electromodulation second-harmonic generation spectroscopy of Si(001)-SiO2_2 interfaces

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    The mechanism of DC-Electric-Field-Induced Second-Harmonic (EFISH) generation at weakly nonlinear buried Si(001)-SiO2_2 interfaces is studied experimentally in planar Si(001)-SiO2_2-Cr MOS structures by optical second-harmonic generation (SHG) spectroscopy with a tunable Ti:sapphire femtosecond laser. The spectral dependence of the EFISH contribution near the direct two-photon E1E_1 transition of silicon is extracted. A systematic phenomenological model of the EFISH phenomenon, including a detailed description of the space charge region (SCR) at the semiconductor-dielectric interface in accumulation, depletion, and inversion regimes, has been developed. The influence of surface quantization effects, interface states, charge traps in the oxide layer, doping concentration and oxide thickness on nonlocal screening of the DC-electric field and on breaking of inversion symmetry in the SCR is considered. The model describes EFISH generation in the SCR using a Green function formalism which takes into account all retardation and absorption effects of the fundamental and second harmonic (SH) waves, optical interference between field-dependent and field-independent contributions to the SH field and multiple reflection interference in the SiO2_2 layer. Good agreement between the phenomenological model and our recent and new EFISH spectroscopic results is demonstrated. Finally, low-frequency electromodulated EFISH is demonstrated as a useful differential spectroscopic technique for studies of the Si-SiO2_2 interface in silicon-based MOS structures.Comment: 31 pages, 14 figures, 1 table, figures are also available at http://kali.ilc.msu.su/articles/50/efish.ht

    Cognitive disorders in patients with chronic kidney disease: specificities of clinical assessment

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    Neurocognitive disorders are frequent among chronic kidney disease (CKD) patients. Identifying and characterizing cognitive impairment (CI) can help to assess the ability of adherence to CKD risk reduction strategy, identify potentially reversible causes of cognitive decline, modify pharmacotherapy, educate the patient and caregiver and provide appropriate patient and caregiver support. Numerous factors are associated with the development and progression of CI in CKD patients and various conditions can influence the results of cognitive assessment in these patients. Here we review clinical warning signs that should lead to cognitive screening; conditions frequent in CKD at risk to interfere with cognitive testing or performance, including specificities of cognitive assessment in dialysis patients or after kidney transplantation; and available tests for screening and observed cognitive patterns in CKD patients

    Folding of Matrix Metalloproteinase-2 Prevents Endogenous Generation of MHC Class-I Restricted Epitope

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    BACKGROUND: We previously demonstrated that the matrix metalloproteinase-2 (MMP-2) contained an antigenic peptide recognized by a CD8 T cell clone in the HLA-A*0201 context. The presentation of this peptide on class I molecules by human melanoma cells required a cross-presentation mechanism. Surprisingly, the classical endogenous processing pathway did not process this MMP-2 epitope. METHODOLOGY/PRINCIPAL FINDINGS: By PCR directed mutagenesis we showed that disruption of a single disulfide bond induced MMP-2 epitope presentation. By Pulse-Chase experiment, we demonstrated that disulfide bonds stabilized MMP-2 and impeded its degradation. Finally, using drugs, we documented that mutated MMP-2 epitope presentation used the proteasome and retrotranslocation complex. CONCLUSIONS/SIGNIFICANCE: These data appear crucial to us since they established the existence of a new inhibitory mechanism for the generation of a T cell epitope. In spite of MMP-2 classified as a self-antigen, the fact that cross-presentation is the only way to present this MMP-2 epitope underlines the importance to target this type of antigen in immunotherapy protocols
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