153 research outputs found

    Combining Multiple Web Accessibility Evaluation Reports using Semantic Web Technologies

    Get PDF
    This paper describes a process for automatic combination of testing reports for the accessibility of Web applications, obtained by different testing tools and applying different standards on Web accessibility. Interoperability is guaranteed using semantic Web technologies, which allow describing the reports by RDF (Resource Description Framework) triples. The reports refer to elements of a knowledge base consisting of vocabularies, ontologies and rules of inference, in which the conceptual relations between accessibility standards, as WCAG (Web Content Accessibility Guidelines) or Section 508 among others, are formalized previously. A software prototype that uses the Apache Jena framework for implementing the process is presented

    Quasinormal modes of massive charged flavor branes

    Get PDF
    We present an analysis and classification of vector and scalar fluctuations in a D3/D7 brane setup at finite termperature and baryon density. The system is dual to an N=2 supersymmetric Yang-Mills theory with SU(N_c) gauge group and N_f hypermultiplets in the fundamental representation in the quenched approximation. We improve significantly over previous results on the quasinormal mode spectrum of D7 branes and stress their novel physical interpretation. Amongst our findings is a new purely imaginary scalar mode that becomes tachyonic at sufficiently low temperature and baryon density. We establish the existence of a critical density above which the scalar mode stays in the stable regime for all temperatures. In the vector sector we study the crossover from the hydrodynamic to the quasiparticle regime and find that it moves to shorter wavelengths for lower temperatures. At zero baryon density the quasinormal modes move toward distinct discrete attractor frequencies that depend on the momentum as we increase the temperature. At finite baryon density, however, the trajectories show a turning behavior such that for low temperature the quasinormal mode spectrum approaches the spectrum of the supersymmetric zero temperature normal modes. We interpret this as resolution of the singular quasinormal mode spectrum that appears at the limiting D7 brane embedding at vanishing baryon density.Comment: 56 pages, 40 figure

    MicroRNA-181a regulates IFN-γ expression in effector CD8+ T cell differentiation

    Get PDF
    CD8+ T cells are key players in immunity against intracellular infections and tumors. The main cytokine associated with these protective responses is interferon-γ (IFN-γ), whose production is known to be regulated at the transcriptional level during CD8+ T cell differentiation. Here we found that microRNAs constitute a posttranscriptional brake to IFN-γ expression by CD8+ T cells since the genetic interference with the Dicer processing machinery resulted in the overproduction of IFN-γ by both thymic and peripheral CD8+ T cells. Using a gene reporter mouse for IFN-γ locus activity, we compared the microRNA repertoires associated with the presence or absence of IFN-γ expression. This allowed us to identify a set of candidates, including miR-181a and miR-451, which were functionally tested in overexpression experiments using synthetic mimics in peripheral CD8+ T cell cultures. We found that miR-181a limits IFN-γ production by suppressing the expression of the transcription factor Id2, which in turn promotes the Ifng expression program. Importantly, upon MuHV-4 challenge, miR-181a-deficient mice showed a more vigorous IFN-γ+ CD8+ T cell response and were able to control viral infection significantly more efficiently than control mice. These data collectively establish a novel role for miR-181a in regulating IFN-γ-mediated effector CD8+ T cell responses in vitro and in vivo.info:eu-repo/semantics/publishedVersio

    Effect of serum phosphate on parathyroid hormone secretion during hemodialysis

    Get PDF
    Effect of serum phosphate on parathyroid hormone secretion during hemodialysis.BackgroundRecent studies have demonstrated that a high concentration of phosphate directly stimulates parathyroid hormone (PTH) secretion. High serum levels of phosphate are usually observed in patients with end-stage renal disease. The aim of the present study was to evaluate whether serum phosphate concentration had an acute effect on PTH secretion in hemodialysis patients. The levels of serum phosphate were manipulated during the hemodialysis session by using a phosphate free dialysate or a dialysate with a high content of phosphate.MethodsTen stable hemodialysis patients with PTH values above 300 pg/ml were included in the study. A PTH-calcium curve was obtained during both high phosphate and phosphate free hemodialysis.ResultsThe serum phosphate concentration remained high (2.17 ± 0.18mM) throughout the high phosphate hemodialysis and decreased progressively to normal levels (1.02 ± 0.06mM) during the phosphate free hemodialysis. The serum PTH levels at maximal inhibition by hypercalcemia (minimal PTH) were greater during the high phosphate than the phosphate free hemodialysis (413 ± 79 vs. 318 ± 76 pg/ml, P < 0.003). In all patients the values of minimum PTH were greater during the high phosphorus than the phosphorus free hemodialysis. The values of maximally stimulated PTH during hypocalcemia and the set point of the PTH-calcium curve were similar during the high phosphate and the phosphate free hemodialysis.ConclusionThe maintenance of high serum phosphorus levels during hemodialysis prevented, in part, the inhibition of PTH secretion by calcium, which strongly suggests that in hemodialysis patients high serum phosphate contributes directly to the elevation of PTH levels despite normal or high serum calcium concentration

    The CARMENES search for exoplanets around M dwarfs: Two planets on opposite sides of the radius gap transiting the nearby M dwarf LTT 3780

    Get PDF
    Full list of authors: Nowak, G.; Luque, R.; Parviainen, H.; Pallé, E.; Molaverdikhani, K.; Béjar, V. J. S.; Lillo-Box, J.; Rodríguez-López, C.; Caballero, J. A.; Zechmeister, M.; Passegger, V. M.; Cifuentes, C.; Schweitzer, A.; Narita, N.; Cale, B.; Espinoza, N.; Murgas, F.; Hidalgo, D.; Zapatero Osorio, M. R.; Pozuelos, F. J.; Aceituno, F. J.; Amado, P. J.; Barkaoui, K.; Barrado, D.; Bauer, F. F.; Benkhaldoun, Z.; Caldwell, D. A.; Casasayas Barris, N.; Chaturvedi, P.; Chen, G.; Collins, K. A.; Collins, K. I.; Cortés-Contreras, M.; Crossfield, I. J. M.; de León, J. P.; Díez Alonso, E.; Dreizler, S.; El Mufti, M.; Esparza-Borges, E.; Essack, Z.; Fukui, A.; Gaidos, E.; Gillon, M.; Gonzales, E. J.; Guerra, P.; Hatzes, A.; Henning, Th.; Herrero, E.; Hesse, K.; Hirano, T.; Howell, S. B.; Jeffers, S. V.; Jehin, E.; Jenkins, J. M.; Kaminski, A.; Kemmer, J.; Kielkopf, J. F.; Kossakowski, D.; Kotani, T.; Kürster, M.; Lafarga, M.; Latham, D. W.; Law, N.; Lissauer, J. J.; Lodieu, N.; Madrigal-Aguado, A.; Mann, A. W.; Massey, B.; Matson, R. A.; Matthews, E.; Montañés-Rodríguez, P.; Montes, D.; Morales, J. C.; Mori, M.; Nagel, E.; Oshagh, M.; Pedraz, S.; Plavchan, P.; Pollacco, D.; Quirrenbach, A.; Reffert, S.; Reiners, A.; Ribas, I.; Ricker, G. R.; Rose, M. E.; Schlecker, M.; Schlieder, J. E.; Seager, S.; Stangret, M.; Stock, S.; Tamura, M.; Tanner, A.; Teske, J.; Trifonov, T.; Twicken, J. D.; Vanderspek, R.; Watanabe, D.; Wittrock, J.; Ziegler, C.; Zohrabi, F.We present the discovery and characterisation of two transiting planets observed by the Transiting Exoplanet Survey Satellite (TESS) orbiting the nearby (d∗ ≈ 22 pc), bright (J ≈ 9 mag) M3.5 dwarf LTT 3780 (TOI-732). We confirm both planets and their association with LTT 3780 via ground-based photometry and determine their masses using precise radial velocities measured with the CARMENES spectrograph. Precise stellar parameters determined from CARMENES high-resolution spectra confirm that LTT 3780 is a mid-M dwarf with an effective temperature of Teff = 3360 ± 51 K, a surface gravity of log g∗ = 4.81 ± 0.04 (cgs), and an iron abundance of [Fe/H] = 0.09 ± 0.16 dex, with an inferred mass of M∗ = 0.379 ± 0.016M· and a radius of R∗ = 0.382 ± 0.012R·. The ultra-short-period planet LTT 3780 b (Pb = 0.77 d) with a radius of 1.35-0.06+0.06 R·, a mass of 2.34-0.23+0.24 M·, and a bulk density of 5.24-0.81+0.94 g cm-3 joins the population of Earth-size planets with rocky, terrestrial composition. The outer planet, LTT 3780 c, with an orbital period of 12.25 d, radius of 2.42-0.10+0.10 R·, mass of 6.29-0.61+0.63 M·, and mean density of 2.45-0.37+0.44 g cm-3 belongs to the population of dense sub-Neptunes. With the two planets located on opposite sides of the radius gap, this planetary system is anexcellent target for testing planetary formation, evolution, and atmospheric models. In particular, LTT 3780 c is an ideal object for atmospheric studies with the James Webb Space Telescope (JWST). © 2020 ESO.CARMENES is an instrument for the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Institut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 "Blue Planets around Red Stars", the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia. This paper includes data collected by the TESS mission. Funding for the TESS mission is provided by the NASA Explorer Program. We acknowledge the use of public TOI Release data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This article is partly based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sanchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. This work makes use of observations from the LCOGT network. This work makes use of observations acquired with the T150 telescope at Sierra Nevada Observatory, operated by the Instituto de Astrofisica de Andalucia (IAACSIC). Some of the Observations in the paper made use of the High-Resolution Imaging instrument 'Alopeke at Gemini-North. `Alopeke was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. IRD is operated by the Astrobiology Center of the National Institutes of Natural Sciences. The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the WalloniaBrussels Federation. TRAPPIST is funded by the Belgian Fund for Scientific Research (Fond National de la Recherche Scientifique, FNRS) under the grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Fundation (SNF). TRAPPIST-North is a project funded by the University of Liege (Belgium), in collaboration with Cadi Ayyad University of Marrakech (Morocco) M.G. and E.J. are F.R.S.-FNRS Senior Research Associate. The authors acknowledge funding from the Spanish Ministry of Economics and Competitiveness through projects PGC2018-098153-B-C31 and AYA2015-69350-C3-2-P. This work is partly supported by JSPS KAKENHI Grant Numbers JP18H01265 and JP18H05439, and JST PRESTO Grant Number JPMJPR1775. V.M.P. acknowledges support from NASA Grant NNX17AG24G. T.H. acknowledges support from the European Research Council under the Horizon 2020 Framework Program via the ERC Advanced Grant Origins 83 24 28. This research has been partially funded by Project No. MDM-2017-0737 Unidad de Excelencia "Maria de Maeztu" -Centro de Astrobiologia (INTA-CSIC). This research acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709) and project AYA2016-794425

    Atomic surface segregation and structural characterization of PdPt bimetallic nanoparticles

    Get PDF
    "Bimetallic nanoparticles are of interest since they lead to many interesting electrical, chemical, catalytic, and optical properties. They are particularly important in the field of catalysis since they show superior catalytic properties than their monometallic counterparts. The structures of bimetallic nanoparticles depend mainly on the synthesis conditions and the miscibility of the two components. In this work, PdPt alloyed-bimetallic nanoparticles (NPs) were synthesized through the polyol method, and characterized using spherical aberration (Cs) corrected scanning transmission electron microscopy (STEM). High-angle annular dark-field (HAADF)-STEM images of bimetallic nanoparticles were obtained. The contrast of images shows that nanoparticles have an alloy structure with an average size of 8.2 nm. Together with the characterization of nanoparticles, a systematic molecular dynamics simulations study focused on the structural stability and atomic surface segregation trends in 923-atom PdPt alloyed-bimetallic NPs was carried out.

    Climate change impacts on crop breeding: Targeting interacting biotic and abiotic stresses for wheat improvement

    Get PDF
    Wheat (Triticum aestivum L.) as a staple crop is closely interwoven into the development of modern society. Its influence on culture and economic development is global. Recent instability in wheat markets has demonstrated its importance in guaranteeing food security across national borders. Climate change threatens food security as it interacts with a multitude of factors impacting wheat production. The challenge needs to be addressed with a multidisciplinary perspective delivered across research, private, and government sectors. Many experimental studies have identified the major biotic and abiotic stresses impacting wheat production, but fewer have addressed the combinations of stresses that occur simultaneously or sequentially during the wheat growth cycle. Here, we argue that biotic and abiotic stress interactions, and the genetics and genomics underlying them, have been insufficiently addressed by the crop science community. We propose this as a reason for the limited transfer of practical and feasible climate adaptation knowledge from research projects into routine farming practice. To address this gap, we propose that novel methodology integration can align large volumes of data available from crop breeding programs with increasingly cheaper omics tools to predict wheat performance under different climate change scenarios. Underlying this is our proposal that breeders design and deliver future wheat ideotypes based on new or enhanced understanding of the genetic and physiological processes that are triggered when wheat is subjected to combinations of stresses. By defining this to a trait and/or genetic level, new insights can be made for yield improvement under future climate conditions

    MARCOT Pathfinder at Calar Alto progress report

    Get PDF
    Ground-Based and Airborne Telescopes IX (2022), Montreal, Jul 17-22, 2022.--Proceedings of SPIE - The International Society for Optical Engineering vol. 12182 Article number 121820MMARCOT Pathfinder is a precursor for MARCOT (Multi Array of Combined Telescopes) at Calar Alto Observatory (CAHA) in Spain. MARCOT is intended to provide CARMENES, currently fiber-fed from the CAHA 3.5m Telescope, with a 5-15m light collecting area from a battery of several tens of small telescopes that are incoherently fed into the final joint single fiber feed of the spectrograph. The modular concept, based on commercially available telescopes, results in cost estimates that are a fraction of the ones for extremely large telescopes (ELT). As a novel approach, MARCOT will employ Multi-Mode Photonic Lanterns (MM-PL) that are being developed as a variant of classical photonic lanterns, to combine the light from the individual telescopes to a single fiber feed to the instrument. This progress report presents the overall concept of MARCOT, the pathfinder telescope and enclosure that is being commissioned at CAHA, the concept of MM-PL, and the next step of installing the Potsdam Multiplex Raman Spectrograph (MRS). MARCOT Pathfinder will be used to validate the conceptual design and predicted performance of MM-PL on sky with a 7-unit telescope prototype. © 2022 SPIE.The authors acknowledge financial support from the State Agency for Research of the Spanish MCIU through the Center of Excellence Severo Ochoa award to the Instituto de Astrofisica de Andalucia (SEV20170709). This research has been partially funded by the Junta de Andalucia (SOMM17 5208 IAA). KM, JD, and MMR acknowledge support from BMBF grant 03Z22AN11 "Astrophotonics", DFG grant 326946494, "NAIR", and BMBF grant 03Z22AI1 "Strategic Investment", at the Zentrum fur Innovationskompetenz innoFSPEC.Peer reviewe
    • …
    corecore