271 research outputs found

    The redshift and broad band spectral energy distribution of NRAO 150

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    Context. NRAO 150 is one of the brightest radio and mm AGN sources on the northern sky. It has been revealed as an interesting source where to study extreme relativistic jet phenomena. However, its cosmological distance has not been reported so far, because of its optical faintness produced by strong Galactic extinction. Aims. Aiming at measuring the redshift of NRAO 150, and hence to start making possible quantitative studies from the source. Methods. We have conducted spectroscopic and photometric observations of the source in the near-IR, as well as in the optical. Results. All such observations have been successful in detecting the source. The near-IR spectroscopic observations reveal strong Hα\alpha and Hβ\beta emission lines from which the cosmological redshift of NRAO 150 (z=1.517±0.002z=1.517\pm0.002) has been determined for the first time. We classify the source as a flat-spectrum radio-loud quasar, for which we estimate a large super-massive black-hole mass 5×109M\sim5\times 10^{9} \mathrm{M_\odot}. After extinction correction, the new near-IR and optical data have revealed a high-luminosity continuum-emission excess in the optical (peaking at 2000\sim2000\,\AA, rest frame) that we attribute to thermal emission from the accretion disk for which we estimate a high accretion rate, 30\sim30\,% of the Eddington limit. Conclusions. Comparison of these source properties, and its broad-band spectral-energy distribution, with those of Fermi blazars allow us to predict that NRAO 150 is among the most powerful blazars, and hence a high luminosity -although not detected yet- γ\gamma-ray emitter.Comment: 8 pages, 4 figure

    Evolution of EEG motor rhythms after spinal cord injury: A longitudinal study

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    Spinal cord injury (SCI) does not only produce a lack of sensory and motor function caudal to the level of injury, but it also leads to a progressive brain reorganization. Chronic SCI patients attempting to move their affected limbs present a significant reduction of brain activation in the motor cortex, which has been linked to the deafferentation. The aim of this work is to study the evolution of the motor-related brain activity during the first months after SCI. Eighteen subacute SCI patients were recruited to participate in bi-weekly experimental sessions during at least two months. Their EEG was recorded to analyze the temporal evolution of the event-related desynchronization (ERD) over the motor cortex, both during motor attempt and motor imagery of their paralyzed hands. The results show that the a and ß ERD evolution after SCI is negatively correlated with the clinical progression of the patients during the first months after the injury. This work provides the first longitudinal study of the event-related desynchronization during the subacute phase of spinal cord injury. Furthermore, our findings reveal a strong association between the ERD changes and the clinical evolution of the patients. These results help to better understand the brain transformation after SCI, which is important to characterize the neuroplasticity mechanisms involved after this lesion and may lead to new strategies for rehabilitation and motor restoration of these patients

    Introducción a las ecuaciones de primer grado. Propuesta para un aula inclusiva de 1º de la e.s.o

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    Este trabajo presenta una propuesta didáctica para la asignatura de Matemáticas de 1º de la E.S.O. Tiene como objetivo desarrollar la introducción de las ecuaciones de primer grado en un aula inclusiva donde nos encontraremos diferentes ritmos de aprendizaje

    “On water” reactivity between carbohydrate-derived nitroalkenes and furans

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    Las reacciones ecológicas "sobre el agua" de derivados de carbohidratos con nitroalkenes furano, 2-methylfuran y furfural N,N-dimethylhydrazone han sido investigados bajo diferentes métodos de mezcla, como un agitador magnético y un agitador de acción con la muñeca. Los furyl derivados cíclicos y acíclicos de los carbohidratos fueron obtenidos con elevada diastereo-selectividad.Eco-friendly “on water” reactions of carbohydrate-derived nitroalkenes with furan, 2-methylfuran and furfural N,N-dimethylhydrazone have been investigated under different mixing methods, such as a magnetic stirrer and a wrist-action shaker. Cyclic and acyclic furyl derivatives from carbohydrates were obtained with high diastereoselectivity.• Gobierno de Extremadura y Fondos FEDER. Ayuda a Grupos de Investigación GR15022 • Universidad de Extremadura. Plan de Iniciación a la Investigación, Desarrollo Tecnológico e Innovación 2015, para Verónica Luque AgudopeerReviewe

    Cutting the cylinder into squares: The square form factor

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    In this article we present a method for constructing two-point functions in the spirit of the hexagon proposal, which leads us to propose a "square form factor". Since cutting the square gives us two squares, we can write a consistency condition that heavily constrains such form factors. In particular, we are able to use this constraint to reconstruct the Gaudin through the forest expansion of the determinant appearing in its definition. We also use this procedure to compute the norm of off-shell Bethe states for some simple cases.Comment: 34 pages, 10 figure

    Portafolios crítico de experiencias de aprendizaje: los sistemas de información geográfica en secundaria y bachillerato

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    “No se puede idear castigo más espantoso para los peores criminales que hacerles estudiar un montón de libros de texto de Geografía como los que los niños de nuestras escuelas se ven condenados a estudiar” (John Richard Green, 1880). Más de un siglo nos separan de esta célebre cita, tiempo en el que sin lugar a ningún tipo de duda, la sociedad ha cambiado enormemente en todos los aspectos. La revolución tecnología ha supuesto una transformación radical en cualquier ámbito de nuestra vida pero ¿Por qué no ha sucedido lo mismo en nuestra forma de educar y de aprender? En el presente Trabajo Fin de Máster se analizan una serie de propuestas y experiencias referentes a la innovación educativa en el ámbito de la Geografía, concretamente relacionadas con la inclusión de las nuevas tecnologías de información geográfica, con el fin de observar sus ventajas, inconvenientes y principales dificultades a la hora de su puesta en práctica en los centros escolares

    Climate-sensitive hydrological drought insurance for irrigated agriculture under deep uncertainty. Insightful results from the Cega River Basin in Spain

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    This paper assesses the feasibility and robustness of an index-based insurance scheme against hydrological droughts under climate change. To this end, we develop a grand ensemble that samples both modeling and scenario uncertainty in the estimation of the insurance risk premium, so to reveal potential unfavorable surprises and minimize regret in the design of the proposed insurance scheme. The grand ensemble combines four microeconomic models and seven GAMLSS models, which are run for three alternative climate change scenarios: stationary climate/no climate change, RCP 2.6, and RCP 8.5. Methods are illustrated with an application to the Cega River Sub-basin (CRS) in central Spain. Results indicate that for a conventional deductible of 30%, the proposed index-based insurance scheme would be actuarially feasible and affordable under all models for the stationary climate scenario (i.e., robust). For climate change scenarios RCP 2.6 and 8.5 and a 30% deductible, the suggested index-based insurance would be actuarially feasible under most models, albeit some outliers point towards potential unfavorable surprises. Lower deductibles decrease feasibility, particularly for deductibles <10%

    The Carbonation of Wollastonite: A Model Reaction to Test Natural and Biomimetic Catalysts for Enhanced CO2 Sequestration

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    One of the most promising strategies for the safe and permanent disposal of anthropogenic CO2 is its conversion into carbonate minerals via the carbonation of calcium and magnesium silicates. However, the mechanism of such a reaction is not well constrained, and its slow kinetics is a handicap for the implementation of silicate mineral carbonation as an effective method for CO2 capture and storage (CCS). Here, we studied the different steps of wollastonite (CaSiO3) carbonation (silicate dissolution -> carbonate precipitation) as a model CCS system for the screening of natural and biomimetic catalysts for this reaction. Tested catalysts included carbonic anhydrase (CA), a natural enzyme that catalyzes the reversible hydration of CO2(aq), and biomimetic metal-organic frameworks (MOFs). Our results show that dissolution is the rate-limiting step for wollastonite carbonation. The overall reaction progresses anisotropically along different [hkl] directions via a pseudomorphic interface-coupled dissolution–precipitation mechanism, leading to partial passivation via secondary surface precipitation of amorphous silica and calcite, which in both cases is anisotropic (i.e., (hkl)-specific). CA accelerates the final carbonate precipitation step but hinders the overall carbonation of wollastonite. Remarkably, one of the tested Zr-based MOFs accelerates the dissolution of the silicate. The use of MOFs for enhanced silicate dissolution alone or in combination with other natural or biomimetic catalysts for accelerated carbonation could represent a potentially effective strategy for enhanced mineral CCS.This research was funded by the Spanish Government (grants CGL2015-70642-R, CGL2015-73103-EXP, CTQ2017-84692-R), EU FEDER funding, the University of Granada (“Unidad Científica de Excelencia” UCE-PP2016-05) and the Junta de Andalucía (grant P11-RNM-7550 and Research Group RNM-179). We thank the personnel of the Centro de Instrumentación Científica (CIC) of the University of Granada for their help during TG-DSC, FESEM, -XRD, and ICP-OES analyses
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