Exploring quality-aware architectural transformations at run-time: the ENIA case

Adapting software systems at run-time is a key issue, especially when these systems consist of components used as intermediary for human-computer interaction. In this sense, model transformation techniques have a widespread acceptance as a mechanism for adapting and evolving the software architecture of such systems. However, existing model transformations often focus on functional requirements, and quality attributes are only manually considered after the transformations are done. This paper aims to improve the quality of adaptations and evolutions in component-based software systems by taking into account quality attributes within the model transformation process. To this end, we present a quality-aware transformation process using software architecture metrics to select among many alternative model transformations. Such metrics evaluate the quality attributes of an architecture. We validate the presented quality-aware transformation process in ENIA, a geographic information system whose user interfaces are based on coarsegrained components and need to be adapted at run-time

Optical characterization of Mg-doped GaN films grown by metalorganic chemical vapor phase deposition

Scanning electron microscopy, micro-Raman, and photoluminescence (PL) measurements are reported for Mg-doped GaN films grown on (0001) sapphire substrates by low-pressure metalorganic chemical vapor phase deposition. The surface morphology, structural, and optical properties of GaN samples with Mg concentrations ranging from 1019 to 1021 cm−3 have been studied. In the scanning micrographs large triangular pyramids are observed, probably due to stacking fault formation and three-dimensional growth. The density and size of these structures increase with the amount of magnesium incorporated in the samples. In the photoluminescence spectra, intense lines were found at 3.36 and 3.31 eV on the triangular regions, where the presence of cubic inclusions was confirmed by micro-Raman measurements. The excitation dependence and temperature behavior of these lines enable us to identify their excitonic nature. From our study we conclude that the interface region between these defects and the surrounding wurtzite GaN could be responsible for PL [email protected] ; [email protected] ; [email protected]

Low-frequency excitations in glassy selenium: A comparison of neutron-scattering and molecular-dynamics results

12 págs.; 9 figs.; 1 tab.The microscopic low-frequency dynamics of glassy selenium is investigated by means of the concurrent use of neutron inelastic scattering and computer simulations. A separation of the dynamic response in terms of intra- and interchain processes is achieved from the analysis of the simulation results. The S(Q,E) dynamic structure factors are analyzed in terms of the frequency moments or from a model scattering law, and the wave-vector dependence of the relevant quantities is established. Finally, the anomalous behavior of the heat capacity at moderately low temperatures is shown to be originated by mostly interchain interactions. © 1993 The American Physical Society.This work has been supported in part by DGICYT Grant No. PB89-0037-C03.Peer Reviewe

X-ray nanoimaging of Nd3+ optically active ions embedded in Sr0.5Ba0.5Nb2O6 nanocrystals

[EN] The spatial distribution of Sr0.5Ba0.5Nb2O6 nanocrystals is analyzed in a borate-based glass-ceramic by a synchrotron hard X-ray nanoimaging tool. Based on X-ray excited optical luminescence, we examined 2D projections of the Nd3+ optically active ions in the Sr0.5Ba0.5Nb2O6 nanocrystals, as well as in the glassy phase where they are embedded. Our findings reveal areas of agglomerations and/or clusters of nanocrystals ascribed to the diffusion coefficients of their constituent elements. They are characterized by high Nd3+ concentrations that may act as heterogeneous agents for the nucleation and growth of these nanocrystals. (C) 2017 Optical Society of AmericaMINECO, EU-FEDER and CSIC through the projects MAT2013-46649-C4-4-P, MAT201571070-REDC, MAT2016-75586-C4-2-P, MAT2016-75586-C4-4-P, 201550I021 and 201660I001, respectively. JAS acknowledges the Spanish Program Ramón y Cajal for his fellowship. We also thank the ESRF for the beam time allocated and experimental facilities.Martínez-Criado, G.; Alén, B.; Sans-Tresserras, JÁ.; Lozano-Gorrín, A.; Haro-González, P.; Martin, I.; Lavin, V. (2017). X-ray nanoimaging of Nd3+ optically active ions embedded in Sr0.5Ba0.5Nb2O6 nanocrystals. Optical Materials Express. 7(7):2424-2431. https://doi.org/10.1364/OME.7.002424S2424243177Nagata, K., Yamamoto, Y., Igarashi, H., & Okazaki, K. (1981). Properties of the hot-pressed strontium barium niobate ceramics. Ferroelectrics, 38(1), 853-856. doi:10.1080/00150198108209556Imai, T., Yagi, S., Yamazaki, H., & Ono, M. (1999). Effects of Heat Treatment on Photorefractive Sensitivity of Ce- and Eu-Doped Strontium Barium Niobate. Japanese Journal of Applied Physics, 38(Part 1, No. 4A), 1984-1988. doi:10.1143/jjap.38.1984Volk, T., Isakov, D., Salobutin, V., Ivleva, L., Lykov, P., Ramzaev, V., & Wöhlecke, M. (2004). Effects of Ni doping on properties of strontium–barium–niobate crystals. Solid State Communications, 130(3-4), 223-226. doi:10.1016/j.ssc.2004.01.039Romero, J. J., Andreeta, M. R. B., Andreeta, E. R. M., Bausá, L. E., Hernandes, A. C., & García Solé, J. (2004). Growth and characterization of Nd-doped SBN single crystal fibers. Applied Physics A, 78(7), 1037-1042. doi:10.1007/s00339-003-2151-3Chayapiwut, N., Honma, T., Benino, Y., Fujiwara, T., & Komatsu, T. (2005). Synthesis of Sm3+-doped strontium barium niobate crystals in glass by samarium atom heat processing. Journal of Solid State Chemistry, 178(11), 3507-3513. doi:10.1016/j.jssc.2005.09.002Haro-González, P., Martín, I. R., Martín, L. L., León-Luis, S. F., Pérez-Rodríguez, C., & Lavín, V. (2011). Characterization of Er3+ and Nd3+ doped Strontium Barium Niobate glass ceramic as temperature sensors. Optical Materials, 33(5), 742-745. doi:10.1016/j.optmat.2010.11.026Ivleva, L. I., Volk, T. R., Isakov, D. V., Gladkii, V. V., Polozkov, N. M., & Lykov, P. A. (2002). Growth and ferroelectric properties of Nd-doped strontium–barium niobate crystals. Journal of Crystal Growth, 237-239, 700-702. doi:10.1016/s0022-0248(01)01997-2Marcinkevičius, A., Juodkazis, S., Watanabe, M., Miwa, M., Matsuo, S., Misawa, H., & Nishii, J. (2001). Femtosecond laser-assisted three-dimensional microfabrication in silica. Optics Letters, 26(5), 277. doi:10.1364/ol.26.000277Sato, R., Benino, Y., Fujiwara, T., & Komatsu, T. (2001). YAG laser-induced crystalline dot patterning in samarium tellurite glasses. Journal of Non-Crystalline Solids, 289(1-3), 228-232. doi:10.1016/s0022-3093(01)00736-0Haro-González, P., Martín, L. L., González-Pérez, S., & Martín, I. R. (2010). Formation of Nd3+ doped Strontium Barium Niobate nanocrystals by two different methods. Optical Materials, 32(10), 1389-1392. doi:10.1016/j.optmat.2010.03.011Haro-González, P., Martín, I. R., & Creus, A. H. (2010). Nanocrystals distribution inside the writing lines in a glass matrix using Argon laser irradiation. Optics Express, 18(2), 582. doi:10.1364/oe.18.000582Haro-González, P., Martín, I. R., Arbelo-Jorge, E., González-Pérez, S., Cáceres, J. M., & Núñez, P. (2008). Laser irradiation in Nd3+ doped strontium barium niobate glass. Journal of Applied Physics, 104(1), 013112. doi:10.1063/1.2952011Kowalska, D., Haro-González, P., Martín, I. R., & Cáceres, J. M. (2010). Analysis of the optical properties of Er3+-doped strontium barium niobate nanocrystals using time-resolved laser spectroscopy. Applied Physics A, 99(4), 771-776. doi:10.1007/s00339-010-5716-yPellicer-Porres, J., Segura, A., Martínez-Criado, G., Rodríguez-Mendoza, U. R., & Lavín, V. (2012). Formation of nanostructures in Eu3+doped glass–ceramics: an XAS study. Journal of Physics: Condensed Matter, 25(2), 025303. doi:10.1088/0953-8984/25/2/025303Martínez-Criado, G., Alén, B., Sans, J. A., Homs, A., Kieffer, I., Tucoulou, R., … Yi, G. (2012). Spatially resolved X-ray excited optical luminescence. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 284, 36-39. doi:10.1016/j.nimb.2011.08.013Martínez-Criado, G., Sans, J. A., Segura-Ruiz, J., Tucoulou, R., Solé, A. V., Homs, A., … Alén, B. (2011). X-ray excited optical luminescence imaging of InGaN nano-LEDs. physica status solidi (c), 9(3-4), 628-630. doi:10.1002/pssc.201100430Villanova, J., Segura-Ruiz, J., Lafford, T., & Martinez-Criado, G. (2012). Synchrotron microanalysis techniques applied to potential photovoltaic materials. Journal of Synchrotron Radiation, 19(4), 521-524. doi:10.1107/s0909049512021383Smith, J., Akbari-Sharbaf, A., Ward, M. J., Murphy, M. W., Fanchini, G., & Kong Sham, T. (2013). Luminescence properties of defects in nanocrystalline ZnO. Journal of Applied Physics, 113(9), 093104. doi:10.1063/1.4794001Armelao, L., Heigl, F., Jürgensen, A., Blyth, R. I. R., Regier, T., Zhou, X.-T., & Sham, T. K. (2007). X-ray Excited Optical Luminescence Studies of ZnO and Eu-Doped ZnO Nanostructures. The Journal of Physical Chemistry C, 111(28), 10194-10200. doi:10.1021/jp071379fMartínez-Criado, G., Villanova, J., Tucoulou, R., Salomon, D., Suuronen, J.-P., Labouré, S., … Morse, J. (2016). ID16B: a hard X-ray nanoprobe beamline at the ESRF for nano-analysis. Journal of Synchrotron Radiation, 23(1), 344-352. doi:10.1107/s1600577515019839Jamieson, P. B., Abrahams, S. C., & Bernstein, J. L. (1968). Ferroelectric Tungsten Bronze‐Type Crystal Structures. I. Barium Strontium Niobate Ba0.27Sr0.75Nb2O5.78. The Journal of Chemical Physics, 48(11), 5048-5057. doi:10.1063/1.1668176Haro-González, P., Martín, I. R., & Hernández Creus, A. (2011). Nanocrystals formation on Ho3+ doped strontium barium niobate glass. Journal of Luminescence, 131(4), 657-661. doi:10.1016/j.jlumin.2010.11.011Lavı́n, V., Rodrı́guez-Mendoza, U. R., Martı́n, I. R., & Rodrı́guez, V. D. (2003). Optical spectroscopy analysis of the Eu3+ ions local structure in calcium diborate glasses. Journal of Non-Crystalline Solids, 319(1-2), 200-216. doi:10.1016/s0022-3093(02)01914-2Chernaya, T. S., Volk, T. R., Verin, I. A., Ivleva, L. I., & Simonov, V. I. (2002). Atomic structure of (Sr0.50Ba0.50)Nb2O6 single crystals in the series of (SrxBa1 − x )Nb2O6 compounds. Crystallography Reports, 47(2), 213-216. doi:10.1134/1.1466494Erbil, A., Cargill III, G. S., Frahm, R., & Boehme, R. F. (1988). Total-electron-yield current measurements for near-surface extended x-ray-absorption fine structure. Physical Review B, 37(5), 2450-2464. doi:10.1103/physrevb.37.2450Solé, V. A., Papillon, E., Cotte, M., Walter, P., & Susini, J. (2007). A multiplatform code for the analysis of energy-dispersive X-ray fluorescence spectra. Spectrochimica Acta Part B: Atomic Spectroscopy, 62(1), 63-68. doi:10.1016/j.sab.2006.12.002Martínez-Criado, G., Homs, A., Alén, B., Sans, J. A., Segura-Ruiz, J., Molina-Sánchez, A., … Yi, G.-C. (2012). Probing Quantum Confinement within Single Core–Multishell Nanowires. Nano Letters, 12(11), 5829-5834. doi:10.1021/nl303178uMartínez-Criado, G., Segura-Ruiz, J., Alén, B., Eymery, J., Rogalev, A., Tucoulou, R., & Homs, A. (2014). Exploring Single Semiconductor Nanowires with a Multimodal Hard X-ray Nanoprobe. Advanced Materials, 26(46), 7873-7879. doi:10.1002/adma.201304345Shyu, J.-J., & Wang, J.-R. (2000). Crystallization and Dielectric Properties of SrO-BaO-Nb2O5-SiO2Tungsten-Bronze Glass-Ceramics. Journal of the American Ceramic Society, 83(12), 3135-3140. doi:10.1111/j.1151-2916.2000.tb01694.

Spatially resolved X-ray excited optical luminescence

Spatially resolved luminescence distributions in semiconductor heterostructures were investigated by core level excitation using hard X-ray (sub-) microbeams. Compact and mobile XEOL instruments have been developed and well adapted on the hard X-ray beamline ID22 of the European Synchrotron Radiation Facility for different wavelength collection ranges: UV-VIS and NIR. Linked by multimode optical fibers, their special designs provide precise scanning microscopy and allow easy access for multiple detection modes. Based on the hard X-ray microprobe station of ID22, details of the equipments, spectral data and representative examples are briefly described. Data collections from InAs and InGaN quantum heterostructures support the excellent performance of the optical devices. © 2011 Elsevier B.V. All rights reserved.This work was partially supported by the NANOWIRING Marie Curie ITN (EU project No. PITN-GA-2010-265073).Peer Reviewe

Estudio y restauración del sable en acero de Damasco de Mehemet Alí

The present manuscript is about study and restoration of a sabre, which belonged to Mehemet Ali. The work has been adopted a scientific and a historical approach. Scientific one has revealed the secrets of Damascus steel, so admired by the power of their swords as well as by the beauty of their beautiful markings, and damascene works. Techniques such as Optical Microscopy, Scanning Electron Microscopy (SEM), ICP Mass and Ultrasonic have been used in order to achieve this scientific research. Historical approach has carried out a work about the contribution of Mehemet Ali, especially to Egypt in the 18th and 19th centuries.El presente artículo trata sobre el estudio y restauración del sable perteneciente a Mehemet Alí. Este trabajo se ha realizado bajo dos enfoques diferentes: científico e histórico. El primero, en donde se han desvelado los secretos internos de este maravilloso y genuino acero de Damasco, tan admirado por el poder de sus espadas como por la belleza de las aguas y damasquinados presentes en las mismas. Para ello nos hemos ayudado de técnicas como la Microscopía Óptica, Microscopía Electrónica de Barrido (MEB), ICP Masas y Ultrasonidos. Bajo el segundo enfoque, se ha realizado un seguimiento histórico de Mehemet Alí, y su contribución al Egipto de los siglos XVIII y XIX

Probing quantum confinement within single core-multishell nanowires

Theoretically core-multishell nanowires under a cross-section of hexagonal geometry should exhibit peculiar confinement effects. Using a hard X-ray nanobeam, here we show experimental evidence for carrier localization phenomena at the hexagon corners by combining synchrotron excited optical luminescence with simultaneous X-ray fluorescence spectroscopy. Applied to single coaxial n-GaN/InGaN multiquantum-well/p-GaN nanowires, our experiment narrows the gap between optical microscopy and high-resolution X-ray imaging and calls for further studies on the underlying mechanisms of optoelectronic nanodevices. © 2012 American Chemical Society.The authors thank Irina Snigireva and Armando Vicente Sole for their assistance with the SEM measurements and data processing using PyMca, respectively. We thank Remi Tocoulou and Peter Cloetens for their help and the ESRF for the beam time allocated. We also thank Andrei Rogalev for the valuable discussions and Gary Admans for the critical reading of the manuscript. This work has been partially supported by the NANOWIRING Marie Curie ITN (EU project no. PITN-GA-2010-265073), as well as by the EPIC-NANOTICS (TEC2011-29120-C05-04) and Q&C-LIGHT (S2009ESP-1503) from Spanish MEC and CAM, respectively.Martínez Criado, G.; Homs Puron, AA.; Alen, B.; Sans Tresserras, JÁ.; Segura Ruiz, J.; Molina Sánchez, A.; Susini, J.... (2012). Probing quantum confinement within single core-multishell nanowires. Nano Letters. 12(11):5829-5834. https://doi.org/10.1021/nl303178uS58295834121

Cell identity and nucleo-mitochondrial genetic context modulate OXPHOS performance and determine somatic heteroplasmy dynamics

Heteroplasmy, multiple variants of mitochondrial DNA (mtDNA) in the same cytoplasm, may be naturally generated by mutations but is counteracted by a genetic mtDNA bottleneck during oocyte development. Engineered heteroplasmic mice with nonpathological mtDNA variants reveal a nonrandom tissue-specific mtDNA segregation pattern, with few tissues that do not show segregation. The driving force for this dynamic complex pattern has remained unexplained for decades, challenging our understanding of this fundamental biological problem and hindering clinical planning for inherited diseases. Here, we demonstrate that the nonrandom mtDNA segregation is an intracellular process based on organelle selection. This cell type-specific decision arises jointly from the impact of mtDNA haplotypes on the oxidative phosphorylation (OXPHOS) system and the cell metabolic requirements and is strongly sensitive to the nuclear context and to environmental cues

Inhibition of inflammatory signaling in Pax5 mutant cells mitigates B-cell leukemogenesis

Altres ajuts: We would like to thank the "Fundación Ramón Areces," a Research Contract with the "Fundación Síndrome de Wolf-Hirschhorn o 4p-", and institutional grants from the "Fundación Ramón Areces" and "Banco de Santander" to the CBMSO. Research in the ISG group is partially supported by by Junta de Castilla y León (UIC-017, CSI001U16, and CSI234P18), and by the German Jose Carreras Foundation (DJCLS R13/26; DJCLS 07R/2019). AC-G and M.I.-H. are supported by FSE-Conserjería de Educación de la Junta de Castilla y León 2019 and 2020 (ESF- European Social Fund) fellowship, respectively. J.R.-G. is supported by a scholarship from University of Salamanca co-financed by Banco Santander and ESF.PAX5 is one of the most frequently mutated genes in B-cell acute lymphoblastic leukemia (B-ALL), and children with inherited preleukemic PAX5 mutations are at a higher risk of developing the disease. Abnormal profiles of inflammatory markers have been detected in neonatal blood spot samples of children who later developed B-ALL. However, how inflammatory signals contribute to B-ALL development is unclear. Here, we demonstrate that Pax5 heterozygosis, in the presence of infections, results in the enhanced production of the inflammatory cytokine interleukin-6 (IL-6), which appears to act in an autocrine fashion to promote leukemia growth. Furthermore, in vivo genetic downregulation of IL-6 in these Pax5 heterozygous mice retards B-cell leukemogenesis, and in vivo pharmacologic inhibition of IL-6 with a neutralizing antibody in Pax5 mutant mice with B-ALL clears leukemic cells. Additionally, this novel IL-6 signaling paradigm identified in mice was also substantiated in humans. Altogether, our studies establish aberrant IL6 expression caused by Pax5 loss as a hallmark of Pax5-dependent B-ALL and the IL6 as a therapeutic vulnerability for B-ALL characterized by PAX5 loss

Ferromagnetism in semiconductors and oxides: prospects from a ten years' perspective

Over the last decade the search for compounds combining the resources of semiconductors and ferromagnets has evolved into an important field of materials science. This endeavour has been fuelled by continual demonstrations of remarkable low-temperature functionalities found for ferromagnetic structures of (Ga,Mn)As, p-(Cd,Mn)Te, and related compounds as well as by ample observations of ferromagnetic signatures at high temperatures in a number of non-metallic systems. In this paper, recent experimental and theoretical developments are reviewed emphasising that, from the one hand, they disentangle many controversies and puzzles accumulated over the last decade and, on the other, offer new research prospects.Comment: review, 13 pages, 8 figures, 109 reference