2,234 research outputs found

    A unified scenario for the origin of spiral and elliptical galaxy structural scaling laws

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    Elliptical (E) and spiral (S) galaxies follow tight, but different, scaling laws that link their stellar masses, radii, and characteristic velocities. Mass and velocity, for example, scale tightly in spirals with little dependence on galaxy radius (the 'Tully-Fisher relation'; TFR). On the other hand, ellipticals appear to trace a 2D surface in size-mass-velocity space (the 'Fundamental Plane'; FP). Over the years, a number of studies have attempted to understand these empirical relations, usually in terms of variations of the virial theorem for E galaxies and in terms of the scaling relations of dark matter halos for spirals. We use Lambda cold dark matter (ΛCDM) cosmological hydrodynamical simulations to show that the scaling relations of both ellipticals and spirals arise as the result of (i) a tight galaxy mass-dark halo mass relation and (ii) the self-similar mass profile of cold dark matter halos. In this interpretation, E and S galaxies of a given stellar mass inhabit halos of similar masses, and their different scaling laws result from the varying amounts of dark matter enclosed within their luminous radii. This scenario suggests a new galaxy distance indicator applicable to galaxies of all morphologies and provides simple and intuitive explanations for long-standing puzzles, such as why the TFR is independent of surface brightness, or what causes the 'tilt' in the FP. Our results provide strong support for the predictions of ΛCDM in the strongly non-linear regime, as well as guidance for further improvements to cosmological simulations of galaxy formation.Fil: Ferrero, Santiago Ismael. University of Oslo; NoruegaFil: Navarro, Julio F.. University of Victoria; CanadáFil: Abadi, Mario Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Benavides Blanco, Jose Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentin

    Special Considerations in Facial Transplantation: A Systematic Review

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    Background: Vascularized composite allotransplantation (VCA) of the face is an exceedingly complex procedure, requiring extensive planning and surgical precision in order to successfully manage patients with facial disfigurements. This review aims to present an overview of the salient anatomic considerations in facial transplantation, as well as give attention to unique patient populations and special considerations. Methods: A literature review was performed in search of articles pertaining to considerations in facial transplantation using the databases PubMed, Web of Science, and Cochrane. Articles selected for further review included full-text articles with an emphasis on specific anatomic defects and how they were addressed in the transplant process, as well as management of special patient populations undergoing facial transplantation. Results: In total, 19 articles were deemed appropriate for inclusion. This systematic review of the literature pertaining to considerations in facial transplantation revealed common themes, as well as the importance of a multidisciplinary approach to the procedure. The ultimate outcome is dependent upon the synchronization of subunits of the allograft and the desired functional outcomes, including osseous, ocular, oral, and otologic considerations. Management of specific pathology and subgroups of patients are critical aspects. Although pediatric face transplantation has not yet been performed, it is likely a future step in the evolution of this procedure. Conclusion: When performing a face transplantation, many components must be considered pre-, intra-, and post-operatively. This systematic review presents specific anatomic considerations, as well as information about special patient populations within this cross-section of multidisciplinary microsurgery, psychiatry, and transplant immunology

    Cambios en la estacionalidad de la vegetación y la carga animal en la provincia de La Pampa (Argentina)

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    Crop production is traversing expansion and intensification processes all over the planet and in consequence the large scale cattle production is being displaced to marginal lands with lower stocking capacity. The objective of this work was to assess the seasonality of vegetation in La Pampa province located in a semiarid region in Argentina and to explore if the variations in seasonality are related to the stocking rate. The hypothesis is the changes in stocking rate of rangelands and its grazing pressure alter the proportion of different vegetation functional groups and so the vegetation seasonality. It is predicted that overgrazing of seasonal grasses will alter the proportion of woody species having consequences over spectral indices. It was analyzed satellite data, particularly the MODIS Enhanced Vegetation Index (EVI) and related it to stocking rate records from SENASA. This work evidences the relationship between the stocking rate and the spectral index EVI, indicator of the primary productivity of vegetation, at departmental scale in the natural areas of Monte and Espinal of La Pampa. Results indicate that in western region (Monte) there was an increment in the stocking rate at department level and a decrease in vegetation seasonality. It is posed that the higher grazing pressure led to the overgrazing of the most palatable herbaceous species, increasing the shrub proportion in landscape.La producción de cultivos está atravesando procesos de expansión e intensificación alrededor de todo el planeta. En consecuencia, la producción ganadera está siendo desplazada hacia tierras marginales de menor capacidad de carga. El objetivo de este trabajo es evaluar la estacionalidad de la vegetación en la provincia de La Pampa, ubicada en la región semiárida argentina; y explorar si las variaciones en la estacionalidad están relacionadas con la carga de ganado vacuno. Se plantea como hipótesis que los cambios en la carga animal y la presión de pastoreo alteran la proporción de diferentes grupos funcionales de vegetación, y de esta manera, su estacionalidad. Se predice que el sobrepastoreo de los pastos más estacionales alterará la proporción de especies leñosas, y ello repercutirá sobre los índices espectrales. Se analizó la información satelital, particularmente el Índice de Vegetación Mejorado (EVI) de MODIS y se lo relacionó con los registros de carga animal de SENASA. Este trabajo evidencia la relación entre la carga animal y el EVI, indicador de la productividad primaria de la vegetación, a la escala de departamento en las áreas naturales del Monte y el Espinal de La Pampa. Los resultados indican que al oeste de la provincia (Monte) hubo un aumento de la carga animal y una disminución de la estacionalidad de la vegetación a escala de departamento. La mayor presión de pastoreo habría conducido al sobrepastoreo de las especies herbáceas más palatables aumentando la proporción de arbustos en el paisaje.Fil: Di Bella, Carlos Marcelo. Instituto Nacional de Tecnología Agropecuaria (Argentina)Fil: Beget, María Eugenia. Instituto Nacional de Tecnología Agropecuaria (Argentina)Fil: Campos, Alfredo Nicolás. Instituto Nacional de Tecnología Agropecuaria (Argentina)Fil: Viglizzo, Ernesto. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Jobbágy, Esteban. Consejo Nacional de Investigaciones Científicas y TécnicasFil: García, Alfredo Gabriel. Instituto Nacional de Tecnología Agropecuaria (Argentina)Fil: Cotroneo, Santiago. Instituto Nacional de Tecnología Agropecuaria (Argentina

    Clinical relevance of galectin-1 and galectin-3 in rheumatoid arthritis patients: Differential regulation and correlation with disease activity

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    Galectins, a family of animal lectins, play central roles in immune system regulation, shaping both innate and adaptive responses in physiological and pathological processes. These include rheumatoid arthritis (RA), a chronic multifactorial autoimmune disease characterized by inflammatory responses that affects both articular and extra-articular tissues. Galectins have been reported to play central roles in RA and its experimental animal models. In this perspective article we present new data highlighting the regulated expression of galectin-1 (Gal-1) and galectin-3 (Gal-3) in sera from RA patients under disease-modifying anti-rheumatic drugs (DMARDs) and/or corticoid treatment in the context of a more comprehensive discussion that summarizes the roles of galectins in joint inflammation. We found that Gal-1 levels markedly increase in sera from RA patients and positively correlate with erythrocyte sedimentation rate (ERS) and disease activity score 28 (DAS-28) parameters. On the other hand, Gal-3 is downregulated in RA patients, but positively correlates with health assessment questionnaire parameter (HAQ). Finally, by generating receiver-operator characteristic (ROC) curves, we found that Gal-1 and Gal-3 serum levels constitute good parameters to discriminate patients with RA from healthy individuals. Our findings uncover a differential regulation of Gal-1 and Gal-3 which might contribute to the anti-inflammatory effects elicited by DMARDs and corticoid treatment in RA patients.Fil: Mendez Huergo, Santiago Patricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Hockl, Pablo Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Stupirski, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Maller, Sebastian Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Morosi, Luciano Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Pinto, Nicolás Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Berón, Ana M.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Musuruana, Jorge L.. Provincia de Santa Fe. Ministerio de Salud. Hospital J. B. Iturraspe; ArgentinaFil: Nasswetter, Gustavo Guillermo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Cavallasca, Javier A.. Provincia de Santa Fe. Ministerio de Salud. Hospital J. B. Iturraspe; ArgentinaFil: Rabinovich, Gabriel Adrián. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

    Modelos para aprendizaje automático en tiempo real sobre entornos de big data

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    En la actualidad existen incontables fuentes de información en tiempo real que provienen de redes de sensores, plataformas de observación del tiempo, mediciones de gases, observación de la tierra desde plataformas satelitales, ciudades inteligentes, entre un sin número de instrumentos que censan y transmiten datos. A su vez, hay una creciente demanda por el desarrollo de herramientas que permitan extraer conocimiento a partir de esos grandes repositorios de datos. El aprendizaje automático es un área de la inteligencia artificial, donde sus métodos contribuyen en el proceso de descubrimiento de conocimiento para la toma de decisiones inteligentes. Las demandas para la extracción de conocimiento en entornos de Big Data han acrecentado el interés por la utilización de técnicas tradicionales de aprendizaje automático en distintos problemas de repositorios masivos y entornos de flujos (o streaming ) de datos donde muchas veces no es posible su almacenamiento, pero se requiere tomar decisiones en tiempo real.Eje: Base de Datos y Minería de Datos.Red de Universidades con Carreras en Informátic

    High precision X-ray logN-logS distributions: implications for the obscured AGN population

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    We have constrained the extragalactic source count distributions over a broad range of X-ray fluxes and in various energy bands to test whether the predictions from X-ray background synthesis models agree with the observational constraints provided by our measurements. We have used 1129 XMM-Newton observations at |b|>20 deg covering a sky area of 132.3 deg^2 to compile the largest complete samples of X-ray objects to date in the 0.5-1 keV, 1-2 keV, 2-4.5 keV, 4.5-10 keV, 0.5-2 keV and 2-10 keV energy bands. Our survey includes in excess of 30,000 sources down to ~10^-15 erg/cm^2/s below 2 keV and down to ~10^{-14} erg/cm^2/s above 2 keV. A break in the source count distributions was detected in all energy bands except the 4.5-10 keV band. An analytical model comprising 2 power-law components cannot adequately describe the curvature seen in the source count distributions. The shape of the logN(>S)-logS is strongly dependent on the energy band with a general steepening apparent as we move to higher energies. This is due to non-AGN populations, comprised mainly of stars and clusters of galaxies, contribute up to 30% of the source population at energies 10^{-13} erg/cm^2/s, and these populations of objects have significantly flatter source count distributions than AGN. We find a substantial increase in the relative fraction of hard X-ray sources at higher energies, from >55% below 2 keV to >77% above 2 keV. However the majority of sources detected above 4.5 keV still have significant flux below 2 keV. Comparison with predictions from the synthesis models suggest that the models might be overpredicting the number of faint absorbed AGN, which would call for fine adjustment of some model parameters such as the obscured to unobscured AGN ratio and/or the distribution of column densities at intermediate obscuration.Comment: Accepted for publication in Astronomy and Astrophysics. Abridged Abstract. 23 pages, 47 figures, 8 table

    Genomes of Fasciola hepatica from the Americas reveal colonization with Neorickettsia Endobacteria related to the agents of Potomac Horse and Human Sennetsu Fevers

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    Food borne trematodes (FBTs) are an assemblage of platyhelminth parasites transmitted through the food chain, four of which are recognized as neglected tropical diseases (NTDs). Fascioliasis stands out among the other NTDs due to its broad and significant impact on both human and animal health, as Fasciola sp., are also considered major pathogens of domesticated ruminants. Here we present a reference genome sequence of the common liver fluke, Fasciola hepatica isolated from sheep, complementing previously reported isolate from cattle. A total of 14,642 genes were predicted from the 1.14 GB genome of the liver fluke. Comparative genomics indicated that F. hepatica Oregon and related food-borne trematodes are metabolically less constrained than schistosomes and cestodes, taking advantage of the richer millieux offered by the hepatobiliary organs. Protease families differentially expanded between diverse trematodes may facilitate migration and survival within the heterogeneous environments and niches within the mammalian host. Surprisingly, the sequencing of Oregon and Uruguay F. hepatica isolates led to the first discovery of an endobacteria in this species. Two contigs from the F. hepatica Oregon assembly were joined to complete the 859,205 bp genome of a novel Neorickettsia endobacterium (nFh) closely related to the etiological agents of human Sennetsu and Potomac horse fevers. Immunohistochemical studies targeting a Neorickettsia surface protein found nFh in specific organs and tissues of the adult trematode including the female reproductive tract, eggs, the Mehlis' gland, seminal vesicle, and oral suckers, suggesting putative routes for fluke-to-fluke and fluke-to-host transmission. The genomes of F. hepatica and nFh will serve as a resource for further exploration of the biology of F. hepatica, and specifically its newly discovered transkingdom interaction with nFh and the impact of both species on disease in ruminants and humans

    Class-B CpG-ODN Formulated With a Nanostructure Induces Type I Interferons-Dependent and CD4+ T Cell-Independent CD8+ T-Cell Response Against Unconjugated Protein Antigen

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    There is a need for new vaccine adjuvant strategies that offer both vigorous antibody and T-cell mediated protection to combat difficult intracellular pathogens and cancer. To this aim, we formulated class-B synthetic oligodeoxynucleotide containing unmethylated cytosine-guanine motifs (CpG-ODN) with a nanostructure (Coa-ASC16 or coagel) formed by self-assembly of 6-0-ascorbyl palmitate ester. Our previous results demonstrated that mice immunized with ovalbumin (OVA) and CpG-ODN formulated with Coa-ASC16 (OVA/CpG-ODN/Coa-ASC16) elicited strong antibodies (IgG1 and IgG2a) and Th1/Th17 cellular responses without toxic systemic effects. These responses were superior to those induced by a solution of OVA with CpG-ODN or OVA/CpG-ODN formulated with aluminum salts. In this study, we investigated the capacity of this adjuvant strategy (CpG-ODN/Coa-ASC16) to elicit CD8+ T-cell response and some of the underlying cellular and molecular mechanisms involved in adaptive response. We also analyzed whether this adjuvant strategy allows a switch from an immunization scheme of three-doses to one of single-dose. Our results demonstrated that vaccination with OVA/CpG-ODN/Coa-ASC16 elicited an antigen-specific long-lasting humoral response and importantly-high quality CD8+ T-cell immunity with a single-dose immunization. Moreover, Coa-ASC16 promoted co-uptake of OVA and CpG-ODN by dendritic cells. The CD8+ T-cell response induced by OVA/CpG-ODN/Coa-ASC16 was dependent of type I interferons and independent of CD4+ T-cells, and showed polyfunctionality and efficiency against an intracellular pathogen. Furthermore, the cellular and humoral responses elicited by the nanostructured formulation were IL-6-independent. This system provides a simple and inexpensive adjuvant strategy with great potential for future rationally designed vaccines

    Diseño de plataforma rotativa para medición de dispositivos acústicos

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    La medición de diversas características de un dispositivo acústico requiere la utilización de equipos, instrumentos, instalaciones y operadores que conforman el sistema de medición. Para medir la directividad de una fuente o receptor sonoro se necesita caracterizar la radiación o sensibilidad en el espacio respectivamente. Por lo cual, la precisión y exactitud del posicionamiento del dispositivo ensayado son factores significativos para obtener resultados plausibles y de calidad. Por lo general, los sistemas automáticos de medición de dispositivos acústicos son complejos y costosos. En este trabajo, se presenta el diseño de una plataforma rotativa de alta precisión angular y bajo costo, implementada con un motor paso a paso, un reductor mecánico y un circuito electrónico de control y excitación, la cual forma parte de un sistema automático de medición de dispositivos acústicos.Publicado en: Mecánica Computacional, vol. XXXV, no. 2Facultad de Ingenierí

    Diseño de plataforma rotativa para medición de dispositivos acústicos

    Get PDF
    La medición de diversas características de un dispositivo acústico requiere la utilización de equipos, instrumentos, instalaciones y operadores que conforman el sistema de medición. Para medir la directividad de una fuente o receptor sonoro se necesita caracterizar la radiación o sensibilidad en el espacio respectivamente. Por lo cual, la precisión y exactitud del posicionamiento del dispositivo ensayado son factores significativos para obtener resultados plausibles y de calidad. Por lo general, los sistemas automáticos de medición de dispositivos acústicos son complejos y costosos. En este trabajo, se presenta el diseño de una plataforma rotativa de alta precisión angular y bajo costo, implementada con un motor paso a paso, un reductor mecánico y un circuito electrónico de control y excitación, la cual forma parte de un sistema automático de medición de dispositivos acústicos.Publicado en: Mecánica Computacional, vol. XXXV, no. 2Facultad de Ingenierí
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