147 research outputs found

    An Improved Taylor Algorithm for Computing the Matrix Logarithm

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    [EN] The most popular method for computing the matrix logarithm is a combination of the inverse scaling and squaring method in conjunction with a Pade approximation, sometimes accompanied by the Schur decomposition. In this work, we present a Taylor series algorithm, based on the free-transformation approach of the inverse scaling and squaring technique, that uses recent matrix polynomial formulas for evaluating the Taylor approximation of the matrix logarithm more efficiently than the Paterson-Stockmeyer method. Two MATLAB implementations of this algorithm, related to relative forward or backward error analysis, were developed and compared with different state-of-the art MATLAB functions. Numerical tests showed that the new implementations are generally more accurate than the previously available codes, with an intermediate execution time among all the codes in comparison.This research was funded by the European Regional Development Fund (ERDF) and the Spanish Ministerio de Economia y Competitividad Grant TIN2017-89314-P.Ibáñez González, JJ.; Sastre, J.; Ruíz Martínez, PA.; Alonso Abalos, JM.; Defez Candel, E. (2021). An Improved Taylor Algorithm for Computing the Matrix Logarithm. Mathematics. 9(17):1-19. https://doi.org/10.3390/math9172018S11991

    Parathyroid Hormone-Related Protein Promotes Inflammation in the kidney with an Obstructed ureter

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    Parathyroid hormone-related protein (PTHrP) promotes fibrogenesis in the acutely damaged kidney. Considering the relation between fibrosis and inflammation, we studied transgenic mice that overexpress PTHrP in the proximal tubule. When unilateral ureteric obstruction was induced in these transgenic mice, we found that they had more renal tubulointerstitial damage, leukocyte influx, and expression of proinflammatory factors than their control littermates. Reversal of PTHrP constitutive overexpression in these transgenic mice or treatment of control mice with the PTHrP antagonist (7–34) decreased this inflammatory response. Losartan, which abolished obstruction-induced endogenous PTHrP upregulation, also decreased the latter response but less effectively in transgenic mice. The PTHrP fragment (1–36) induced nuclear factor-jB (NF-jB) activation and proinflammatory cytokine overexpression in mouse cortical tubule cells in culture as well as migration of the macrophage cell line Raw 264.7. All these effects were decreased by PTHrP (7–34) and NF-jB or extracellular signal-regulated kinase (ERK) activation inhibitors. Our findings suggest a critical role of PTHrP in the renal inflammatory process that results from ureteral obstruction and indicate that ERK-mediated NF-jB activation seems to be an important mechanism whereby PTHrP triggers renal inflammatio

    Crecimiento y Eficiencia en el Uso de Nutrientes de Plantas de Pinus cooperi C. E. Blanco Producidas en Vivero con un Fertilizante de Liberación Controlada

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    La fertilización es una de las actividades más importantes y costosas en la producción de plantas forestales en contenedor. La aplicación de fertilizantes de liberación controlada (FLC) permite disminuir costos, al ser incorporados en el sustrato en un sólo evento. Sin embargo, es necesario definir la dosis óptima con base a las necesidades nutricionales de cada especie. El objetivo de este estudio fue determinar el efecto de tres dosis de FLC en el crecimiento morfológico y en la eficiencia del uso de nitrógeno (EUN) en plantas de Pinus cooperi C. E. Blanco en vivero. Como fertilizante se utilizó Multicote 8® [18-6-12 de nitrógeno (N), fósforo (P) y potasio (K)] en tres dosis: 4, 6 y 8 g L-1 de sustrato. A las 49 semanas de cultivo se evaluó el diámetro en la base del tallo, la altura, el peso seco aéreo y de la raíz, y su relación. Se realizó un análisis foliar de N, P y K para determinar el estado nutricional de las plantas mediante análisis de vectores y EUN. Los tratamientos se analizaron bajo un diseño completamente al azar con análisis de varianzas (ANOVA) y pruebas de medias de Tukey. Los individuos fertilizados con dosis de 6 y 8 g L-1 tuvieron mejores atributos morfológicos. La relación de peso seco aéreo / peso seco radicular se mantuvo en los valores deseables en todos los tratamientos. El contenido de N, P y K fue superior con las dosis de 6 y 8 g L-1, aunque la EUN se incrementó a medida que la dosis de FLC fue menor. Los nomogramas de vectores indican que una dosis alta no tiene un efecto en el crecimiento, incluso puede existir toxicidad por fertilización excesiva. Se concluye que la dosis de 6 g L-1 de FLC favorece el crecimiento y nutrición de P. cooperi en vivero

    Control formal a través de la Geometría y la Representación: fundamentos históricos

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    Junta de Andalucía-Consejería de Política TerritorialEscuela Técnica Superior de Arquitectura de la Universidad de SevillaExcm. Ayuntamiento de SevillaColegio Oficial de Arquitectos de Andalucía Occidenta

    Contralateral asymmetry for breast cancer detection : A CADx approach

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    Early detection is fundamental for the effective treatment of breast cancer and the screening mammography is the most common tool used by the medical community to detect early breast cancer development. Screening mammograms include images of both breasts using two standard views, and the contralateral asymmetry per view is a key feature in detecting breast cancer. we propose a methodology to incorporate said asymmetry information into a computer-aided diagnosis system that can accurately discern between healthy subjects and subjects at risk of having breast cancer. Furthermore, we generate features that measure not only a view-wise asymmetry, but a subject-wise one. Briefly, the methodology co-registers the left and right mammograms, extracts image characteristics, fuses them into subjectwise features, and classifies subjects. In this study, 152 subjects from two independent databases, one with analog- and one with digital mammograms, were used to validate the methodology. Areas under the receiver operating characteristic curve of 0.738 and 0.767, and diagnostic odds ratios of 23.10 and 9.00 were achieved, respectively. In addition, the proposed method has the potential to rank subjects by their probability of having breas

    Hypercytokinemia in COVID-19: Tear cytokine profile in hospitalized COVID-19 patients

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    The aim of this study is to analyze the concentrations of cytokines in tear of hospitalized COVID-19 patients compared to healthy controls. Tear samples were obtained from 41 healthy controls and 62 COVID-19 patients. Twenty-seven cytokines were assessed: interleukin (IL)-1b, IL-1RA, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL9, IL-10, IL-12, IL-13, IL-15, IL-17, eotaxin, fibroblast growth factor basic, granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte colony-stimulating factor (GM-CSF), interferon (IFN)-γ, interferon gamma-induced protein, monocyte chemo-attractant protein-1, macrophage inflammatory protein (MIP)-1a, MIP-1b, platelet-derived growth factor (PDGF), regulated on activation normal T cell expressed and secreted, tumor necrosis factor-α and vascular endothelial growth factor (VEGF). In tear samples of COVID-19 patients, an increase in IL-9, IL-15, G-CSF, GM-CSF, IFN-γ, PDGF and VEGF was observed, along with a decrease in eotaxin compared to the control group (p < 0.05). A poor correlation between IL-6 levels in tear and blood was found. IL-1RA and GM-CSF were significantly lower in severe patients and those who needed treatment targeting the immune system (p < 0.05). Tear cytokine levels corroborate the inflammatory nature of SARS-CoV-2

    Successful development and clinical translation of a novel anterior lamellar artificial cornea

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    We thank the Andalusian Public Foundation Progress and Health, through the Andalusian Initiative for Advanced Therapies, for assuming the roles and responsibilities of sponsoring this clinical trial. We thank Dr. Manuel de la Rosa and Dr. Salvador Arias Santiago for providing insight and expertise that assisted the research.The datasets generated and/or analyzed during the current study are available in the Gene Expression Omnibus (GEO) public repository, ref. GSE86584 https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE86584Blindness due to corneal diseases is a common pathology affecting up to 23 million individuals worldwide. The tissue‐engineered anterior human cornea, which is currently being tested in a Phase I/II clinical trial to treat severe corneal trophic ulcers with preliminary good feasibility and safety results. This bioartificial cornea is based on a nanostructured fibrin–agarose biomaterial containing human allogeneic stromal keratocytes and cornea epithelial cells, mimicking the human native anterior cornea in terms of optical, mechanical, and biological behavior. This product is manufactured as a clinical‐grade tissue engineering product, fulfilling European requirements and regulations. The clinical translation process included several phases: an initial in vitro and in vivo preclinical research plan, including preclinical advice from the Spanish Medicines Agency followed by additional preclinical development, the adaptation of the biofabrication protocols to a good manufacturing practice manufacturing process, including all quality controls required, and the design of an advanced therapy clinical trial. The experimental development and successful translation of advanced therapy medicinal products for clinical application has to overcome many obstacles, especially when undertaken by academia or SMEs. We expect that our experience and research strategy may help future researchers to efficiently transfer their preclinical results into the clinical settings.This study was supported by the Spanish National Plan for Scientific and Technical Research and Innovation (I + D + I) from the Spanish Ministry of Economy and Competitiveness (Carlos III Institute of Health), grants FIS PI14/0955 and FIS PI17/0391 (both cofinanced by ERDF‐FEDER, European Union); by the Spanish Ministry of Health, Social Policy and Equity, grant EC10‐285; and by preclinical research funds from the Regional Ministry of Health through the Andalusian Initiative for Advanced Therapies

    Archeological patrimony spatial data infrastructure implementation: Tolmo de Minateda

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    En este artículo se presenta la solución desarrollada para una Infraestructura de Datos Espaciales Arqueológica incorporando productos geomáticos de muy alta resolución. El caso de estudio principal es el Parque Arqueológico del Tolmo de Minateda (Hellín, Albacete). Entre la información geográfica de alta resolución publicada se incluyen ortoimágenes, modelos digitales de superficie, nubes de puntos y el marco de referencia topográfico. En el artículo se describe el instrumental y la metodología empleadas en su producción. La IDE implementada intenta cumplir los estándares aplicables, integrando entre sus componentes un visualizador, un directorio de servicios, y un catálogo de metadatos de datos y servicios. Entre las características que diferencian al visualizador desarrollado de los convencionales en las IDE destaca la particularidad de permitir desplegar visualizadores 3D de algunos productos geomáticos, nubes de puntos y modelos texturizados. También se integra gestión de usuarios para controlar la información accesible en función de cada perfil. Finalmente, en el propio visor se incorporan herramientas de descarga de productos geomáticos. Para el proyecto se ha desarrollado un portal web a modo de gestor de contenidos disponible en: http://www.archaeo3dwebgis.com. Para la presentación del proyecto se ha preparado un vídeo accesible desde la propia web del proyecto o mediante el enlace: https://vimeo.com/242930977.In this article we present the solution developed for an Archeological SDI including very high resolution geomatic respurces. The main study case is the Archaeological Park of Tolmo de Minateda (Hellín, Albacete). High resolution published geographical information includes orthoimages, digital surface models, point clouds and the topographic reference frame. This article describes the instruments and methodology used in its production. The implemented SDI tries to be comnformant with applicable standards, integrating in its components a viewer, a services directory, and a catalog of data and services metadata. Among the characteristics that differentiate the developed visewer from the usual ones in other SDIs, it is remarkable the possibility of open 3D viewers for some geomatics products, point clouds and textured models. User management is also integrated to control the information accessible according to each profile. Finally, geomatic products download tools are incorporated into the viewer. For the project, a web portal has been developed as a content manager available at: http://www.archaeo3dwebgis.com. For the presentation of the project, a video has been prepared and it is accessible from the project website or through the link: https://vimeo.com/242930977
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