131 research outputs found

    Special Geometry of Euclidean Supersymmetry III: the local r-map, instantons and black holes

    Full text link
    We define and study projective special para-Kahler manifolds and show that they appear as target manifolds when reducing five-dimensional vector multiplets coupled to supergravity with respect to time. The dimensional reductions with respect to time and space are carried out in a uniform way using an epsilon-complex notation. We explain the relation of our formalism to other formalisms of special geometry used in the literature. In the second part of the paper we investigate instanton solutions and their dimensional lifting to black holes. We show that the instanton action, which can be defined after dualising axions into tensor fields, agrees with the ADM mass of the corresponding black hole. The relation between actions via Wick rotation, Hodge dualisation and analytic continuation of axions is discussed.Comment: 72 pages, 2 figure

    Aplicaciones de la espectroscopía SERS (Surface-Enhanced Raman Scattering) a la detección de pigmentos orgánicos naturales en objetos del Patrimonio Cultural

    Get PDF
    16 páginas, 17 figuras.La espectroscopía Raman, cuyas prestaciones se han visto considerablemente mejoradas en los últimos 15 años debido a la introducción de técnicas de microscopía (que han sido posibles gracias a importantes avances tecnológicos en filtros ópticos y detectores de alta sensibilidad), se ha convertido en una técnica de identificación molecular de gran utilidad en el campo del Patrimonio Cultural [1]. Al igual que la más conocida espectroscopía Infrarroja, la espectroscopía Raman proporciona información sobre los compuestos moleculares presentes en la muestra bajo estudio, ampliando por ello la información acerca de la presencia de elementos químicos que suministran otras técnicas espectroscópicas tales como XRF, SEM - EDX, PIXE y LIBS utilizadas habitualmente en el análisis de objetos artísticos [2]. Hoy en día podemos encontrar la técnica de microscopía Raman en los departamentos de Conservación y Restauración de los más importantes Museos y Bibliotecas de todo el mundo, utilizándose como técnica no destructiva (incluso in situ) para diagnóstico de diferentes materiales que van desde los pigmentos inorgánicos hasta los biomateriales, en objetos artísticos tan diferentes como manuscritos, pinturas, textiles, cerámicas, vidrios, esculturas, monumentos, e incluso momias o cañones hundidos. La información que se obtiene puede resultar decisiva para la datación y autenticación de las obras artísticas, y ayuda a determinar los cambios físicos y/o químicos que han contribuido a su deterioro a través de la identificación de los productos de degradación de los materiales originales.Agradecemos al MICINN (Proyectos FIS2007-63065 y CONSOLIDER CSD 2007- 0058) y a la Comunidad de Madrid (MICROSERES, S2009TIC-1476) por la financiación parcial de los trabajos aquí expuestos. Agradecemos también el apoyo recibido de la Red Temática de Patrimonio Histórico y Cultural (CSIC). MVC y EdP agradecen al CSIC y al FSE 2007-2013 la concesión de sus respectivos Contratos post- y predoctoral.Peer reviewe

    High precision measurement of the radiative capture cross section of 238U at the n-TOF CERN facility

    Get PDF
    The importance of improving the accuracy on the capture cross-section of 238U has been addressed by the Nuclear Energy Agency, since its uncertainty significantly affects the uncertainties of key design parameters for both fast and thermal nuclear reactors. Within the 7th framework programme ANDES of the European Commission three different measurements have been carried out with the aim of providing the 238U(n,γ) cross-section with an accuracy which varies from 1 to 5%, depending on the energy range. Hereby the final results of the measurement performed at the n TOF CERN facility in a wide energy range from 1 eV to 700 keV will be presented

    Does ALS-FUS without FUS mutation represent ALS-FET? Report of three cases

    Get PDF
    Altres ajuts: This study was partially funded by Fundacio Marató de TV3 (grant no. 20143810 to RSV, no. 20141610 to EG and no. 201437.10 to RRG) and Fondo Europeo de Desarrollo Regional (FEDER) (PI16/01673 to JG and PI15/01618 to RRG). We are indebted to the Neurological Tissue Bank of the Biobanc-Hospital Clinic-IDIBAPS, Barcelona, Spain, for data and sample procurement. We thank Sara Charif, Veronica Santiago, Carmen Schweiger, Leire Etxarri and Abel Muñoz for technical assistance

    Clinical and laboratory features of anti-MAG neuropathy without monoclonal gammopathy

    Get PDF
    Antibodies against myelin-associated glycoprotein (MAG) almost invariably appear in the context of an IgM monoclonal gammopathy associated neuropathy. Very few cases of anti-MAG neuropathy lacking IgM-monoclonal gammopathy have been reported. We investigated the presence of anti-MAG antibodies in 69 patients fulfilling diagnostic criteria for CIDP. Anti-MAG antibodies were tested by ELISA and confirmed by immunohistochemistry. We identified four (5.8%) anti-MAG positive patients without detectable IgM-monoclonal gammopathy. In two of them, IgM-monoclonal gammopathy was detected at 3 and 4-year follow-up coinciding with an increase in anti-MAG antibodies titers. In conclusion, anti-MAG antibody testing should be considered in chronic demyelinating neuropathies, even if IgM-monoclonal gammopathy is not detectable

    Re-programming mouse liver-resident invariant natural killer T cells for suppressing hepatic and diabetogenic autoimmunity

    Full text link
    Invariant NKT (iNKT) cells comprise a heterogeneous group of non-circulating, tissue-resident T lymphocytes that recognize glycolipids, including alpha-galactosylceramide (?GalCer), in the context of CD1d, but whether peripheral iNKT cell subsets are terminally differentiated remains unclear. Here we show that mouse and human liver-resident ?GalCer/CD1d-binding iNKTs largely correspond to a novel Zbtb16+Tbx21+Gata3+MaflowRorc- subset that exhibits profound transcriptional, phenotypic and functional plasticity. Repetitive in vivo encounters of these liver iNKT (LiNKT) cells with intravenously delivered ?GalCer/CD1d-coated nanoparticles (NP) trigger their differentiation into immunoregulatory, IL-10+IL-21-producing Zbtb16highMafhighTbx21+Gata3+Rorc- cells, termed LiNKTR1, expressing a T regulatory type 1 (TR1)-like transcriptional signature. This response is LiNKT-specific, since neither lung nor splenic tissue-resident iNKT cells from ?GalCer/CD1d-NP-treated mice produce IL-10 or IL-21. Additionally, these LiNKTR1 cells suppress autoantigen presentation, and recognize CD1d expressed on conventional B cells to induce IL-10+IL-35-producing regulatory B (Breg) cells, leading to the suppression of liver and pancreas autoimmunity. Our results thus suggest that LiNKT cells are plastic for further functional diversification, with such plasticity potentially targetable for suppressing tissue-specific inflammatory phenomena.© 2022. The Author(s)

    Cryptic population structure reveals low dispersal in Iberian wolves

    Get PDF
    Abstract Highly mobile mammalian carnivores are expected to have the capability to maintain high levels of gene flow across large geographic scales. Nonetheless, surprising levels of genetic structure have been found in many such populations. We combined genetic and spatial behavioural information from wolves (Canis lupus) in the Iberian Peninsula (Western Europe) during the last two decades to present a particular case of low dispersal levels in a large carnivore population persisting in human-dominated landscapes. We found an exceptionally reticulated pattern of cryptic population structure emerging at two hierarchical levels, in which four or eleven meaningful genetic clusters can be recognized, respectively. These clusters were characterized by moderate-high levels of differentiation (average pairwise FST = 0.09–0.19), low levels of admixture and varying degrees of genetic diversity. The number of dispersers identified among the 11 clusters was very low (<4% out of 218 wolves). Spatial information of tracked wolves further confirmed the geographical genetic patterns (only 2 out of 85 collared wolves overlapped with more than one genetic cluster). The high levels of genetic structure in this population may be determined by the recent demographic history of this population, among other factors. The identification of meaningful genetic clusters has implications for the delineation of conservation units and, consequently, on the conservation and management actions for Iberian wolves

    Preferred Growth Direction by PbS Nanoplatelets Preserves Perovskite Infrared Light Harvesting for Stable, Reproducible, and Efficient Solar Cells

    Get PDF
    Formamidinium‐based perovskite solar cells (PSCs) present the maximum theoretical efficiency of the lead perovskite family. However, formamidinium perovskite exhibits significant degradation in air. The surface chemistry of PbS has been used to improve the formamidinium black phase stability. Here, the use of PbS nanoplatelets with (100) preferential crystal orientation is reported, to potentiate the repercussion on the crystal growth of perovskite grains and to improve the stability of the material and consequently of the solar cells. As a result, a vertical growth of perovskite grains, a stable current density of 23 mA cm−2, and a stable incident photon to current efficiency in the infrared region of the spectrum for 4 months is obtained, one of the best stability achievements for planar PSCs. Moreover, a better reproducibility than the control device, by optimizing the PbS concentration in the perovskite matrix, is achieved. These outcomes validate the synergistic use of PbS nanoplatelets to improve formamidinium long‐term stability and performance reproducibility, and pave the way for using metastable perovskite active phases preserving their light harvesting capability

    Cenozoic deformation of Iberia: a model for intraplate mountain building and basin development based on analogue modelling

    Get PDF
    Inferences from analogue models support lithospheric folding as the primary response to large-scale shortening manifested in the present day topography of Iberia. This process was active from the late Oligocene-early Miocene during the Alpine orogeny and was probably enhanced by reactivation of inherited Variscan faults. The modeling results confirm the dependence of fold wavelength on convergence rate and hence the strength of the layers of the lithosphere such that fold wavelength is longest for fast convergence rates favoring whole lithosphere folding. Folding is associated with the formation of dominantly pop-up type mountain ranges in the brittle crust and thickening of the ductile layers in the synforms of the buckle folds by flow. The mountain ranges are represented by upper crustal pop-ups forming the main topographic relief. The wavelengths of the topographic uplifts, both, in model and nature suggest mechanical decoupling between crust and mantle. Moreover, our modeling results suggest that buckling in Iberia took place under rheological conditions where the lithospheric mantle is stronger than the lower crust. The presence of an indenter, inducing oblique shortening in response to the opening of the King's Trough in the north western corner of the Atlantic Iberian margin controls the spacing and obliquity of structures. This leads to the transfer of the deformation from the moving walls towards the inner part of the model, creating oblique structures in both brittle and ductile layers. The effect of the indenter, together with an increase on the convergence rate produced more complex brittle structures. These results show close similarities to observations on the general shape and distribution of mountain ranges and basins in Iberia, including the Spanish Central System and Toledo Mountains.Peer reviewe
    corecore