Properties of the inner penumbral boundary and temporal evolution of a decaying sunspot

It was empirically determined that the umbra-penumbra boundaries of stable sunspots are characterized by a constant value of the vertical magnetic field. We analyzed the evolution of the photospheric magnetic field properties of a decaying sunspot belonging to NOAA 11277 between August 28 - September 3, 2011. The observations were acquired with the spectropolarimeter on-board of the Hinode satellite. We aim to proof the validity of the constant vertical magnetic-field boundary between the umbra and penumbra in decaying sunspots. A spectral-line inversion technique was used to infer the magnetic field vector from the full-Stokes profiles. In total, eight maps were inverted and the variation of the magnetic properties in time were quantified using linear or quadratic fits. We found a linear decay of the umbral vertical magnetic field, magnetic flux, and area. The penumbra showed a linear increase of the vertical magnetic field and a sharp decay of the magnetic flux. In addition, the penumbral area quadratically decayed. The vertical component of the magnetic field is weaker on the umbra-penumbra boundary of the studied decaying sunspot compared to stable sunspots. Its value seem to be steadily decreasing during the decay phase. Moreover, at any time of the shown sunspot decay, the inner penumbra boundary does not match with a constant value of the vertical magnetic field, contrary to what was seen in stable sunspots. During the decaying phase of the studied sunspot, the umbra does not have a sufficiently strong vertical component of the magnetic field and is thus unstable and prone to be disintegrated by convection or magnetic diffusion. No constant value of the vertical magnetic field was found for the inner penumbral boundary.Comment: Accepted for publication in Astronomy & Astrophysics, 6 pages, 7 figure

Tierra, fuego, agua y aire: la escultura en Raku

La incorporación al Espacio Europeo de Educación Superior, ha traído consigo cambios metodológicos docentes. Los departamentos de Escultura y Pintura de la Facultad de Bellas Artes no han querido ser ajenos a ellos y desde los mismos varios profesores hemos diseñado y llevado a cabo una actividad docente común centrada en los alumnos a través de la técnica del aprendizaje activo. Estudiantes de tercero, cuarto y quinto curso de licenciatura y grado han ejercitado diferentes competencias profesionales partiendo de un problema común propuesto: el diseño y construcción de un horno artesanal y la ideación y realización de esculturas cociéndolas en el mismo con la técnica del raku. El objetivo no era únicamente la resolución del problema sino que el alumno fuera capaz de adquirir y aplicar todo un conjunto de conocimientos tanto teóricos como prácticos de la disciplina convirtiéndose en protagonista de su propio aprendizaje. Los resultados se plasmaron posteriormente en la exposición de las obras y en la publicación del desarrollo del proceso en el campus virtualPeer Reviewe

Rapid and MR-Independent IK1 activation by aldosterone during ischemia-reperfusion

In ST elevation myocardial infarction (STEMI) context, clinical studies have shown the deleterious effect of high aldosterone levels on ventricular arrhythmia occurrence and cardiac mortality. Previous in vitro reports showed that during ischemia-reperfusion, aldosterone modulates K+ currents involved in the holding of the resting membrane potential (RMP). The aim of this study was to assess the electrophysiological impact of aldosterone on IK1 current during myocardial ischemia-reperfusion. We used an in vitro model of “border zone” using right rabbit ventricle and standard microelectrode technique followed by cell-attached recordings from freshly isolated rabbit ventricular cardiomyocytes. In microelectrode experiments, aldosterone (10 and 100 nmol/L, n=7 respectively) increased the action potential duration (APD) dispersion at 90% between ischemic and normoxic zones (from 95±4ms to 116±6 ms and 127±5 ms respectively, P<0.05) and reperfusion-induced sustained premature ventricular contractions occurrence (from 2/12 to 5/7 preparations, P<0.05). Conversely, potassium canrenoate 100 nmol/L and RU 28318 1 μmol/l alone did not affect AP parameters and premature ventricular contractions occurrence (except Vmax which was decreased by potassium canrenoate during simulated-ischemia). Furthermore, aldosterone induced a RMP hyperpolarization, evoking an implication of a K+ current involved in the holding of the RMP. Cell-attached recordings showed that aldosterone 10 nmol/L quickly activated (within 6.2±0.4 min) a 30 pS K+-selective current, inward rectifier, with pharmacological and biophysical properties consistent with the IK1 current (NPo =1.9±0.4 in control vs NPo=3.0±0.4, n=10, P<0.05). These deleterious effects persisted in presence of RU 28318, a specific MR antagonist, and were successfully prevented by potassium canrenoate, a non specific MR antagonist, in both microelectrode and patch-clamp recordings, thus indicating a MR-independent IK1 activation. In this ischemia-reperfusion context, aldosterone induced rapid and MR-independent deleterious effects including an arrhythmia substrate (increased APD90 dispersion) and triggered activities (increased premature ventricular contractions occurrence on reperfusion) possibly related to direct IK1 activation

Precipitation strengthening and reversed yield stress asymmetry in Mg alloys containing rare-earth elements: A quantitative study

AbstractThe effect of prismatic plates on the mechanical behaviour at low and high temperature of a Mg-1 wt.% Mn- 1 wt%Nd alloy was determined. For this purpose, a weakly textured extruded bar, exhibiting similar values for the critical resolved shear stresses of the various deformation systems, was annealed at 275 °C for different time periods. During these thermal treatments the grain size and texture remained invariant, but different precipitate distributions, characterised by transmission electron microscopy (TEM), were generated. The as-extruded and the annealed material were tested under tension and compression at room temperature (RT) and 250 °C along the extrusion direction. Precipitation was observed to harden the alloy at RT and to induce a reversed yield stress (YS) asymmetry, the compressive YS being higher than the tensile YS. At 250 °C, the alloy is anomalously resistant under compressive conditions, exhibiting an enhanced reversed YS asymmetry. In order to assess the strengthening effect of particles on the individual major Mg deformation systems, appropriate versions of the Orowan equation were developed. The correlation of the predicted results with the experimental data revealed that reversed YS asymmetry at RT is attributable to a strong promotion of prismatic slip over twinning. Finally, experimental observations by TEM suggested that reversed YS asymmetry at high temperature arises from a different interaction of pyramidal <c+a> dislocations with particles and solutes in tension and compression

Temporal evolution of arch filaments as seen in He I 10830 \r{A}

We study the evolution of an arch filament system (AFS) and of its individual arch filaments to learn about the processes occurring in them. We observed the AFS at the GREGOR solar telescope on Tenerife at high cadence with the very fast spectroscopic mode of the GREGOR Infrared Spectrograph (GRIS) in the He I 10830 \AA\ spectral range. The He I triplet profiles were fitted with analytic functions to infer line-of-sight (LOS) velocities to follow plasma motions within the AFS. We tracked the temporal evolution of an individual arch filament over its entire lifetime, as seen in the He I 10830 \AA\ triplet. The arch filament expanded in height and extended in length from 13" to 21". The lifetime of this arch filament is about 30 min. About 11 min after the arch filament is seen in He I, the loop top starts to rise with an average Doppler velocity of 6 km/s. Only two minutes later, plasma drains down with supersonic velocities towards the footpoints reaching a peak velocity of up to 40 km/s in the chromosphere. The temporal evolution of He I 10830 \AA\ profiles near the leading pore showed almost ubiquitous dual red components of the He I triplet, indicating strong downflows, along with material nearly at rest within the same resolution element during the whole observing time. We followed the arch filament as it carried plasma during its rise from the photosphere to the corona. The material then drained toward the photosphere, reaching supersonic velocities, along the legs of the arch filament. Our observational results support theoretical AFS models and aids in improving future models.Comment: Accepted for publication in Astronomy & Astrophysics, 12 pages, 15 figures, 1 online movi

WMS Integrator: continuous access to neighboring WMS

The INSPIRE Directive, and SDI initiatives, promote that geographic data (GI) is updated and maintained in the most appropriate level or who is responsible. This fact motivates the emergence of many map services (WMS) that offer the same data in different geographical contexts. The atomization of WMS, for geographic domains, difficult the use for users interested in a topic: they must search for WMS, select layers and handle overlapping. This poster presents a facilitator node that manages WMS: URLs, layers, CRS, formats and versions, and offering a seamless WMS that integrate horizontally and vertically layers offered by WMS cascaded. The most important contributions of developed facilitator node (WMS-integrator) are the ability to: carry out some verifications, requests to the different WMS versions, mask spatially responses by boundaries polygons and merge the responses to finally deliver a single image as result that avoid data overlappin

Revisión crítica de la estimulación subtalámica en la enfermedad de Parkinson

The authors critically review subthalamic nucleus (STN) stimulation for Parkinson's disease (PD) at long follow-up (3-5 years). Subthalamic stimulation induce a significant improvement during the "off" medication in the assessment motor score UPDRS (Unified Parkinson Disease Rating Scale) 3-5 years after surgery. Results show that the benefits obtained in tremor, rigidity, bradykinesia, dyskinesias induced by medication and levodopa reduction are significantly maintained during long term. The improvement in other clinical signs as gait and postural stability at long follow-up are not maintained comparing with the benefits obtained one year after surgery. A high percentage of patients show a cognitive disturbance during the follow-up period that may be correlated with the disease progression. The conclusion is that bilateral STN stimulation is an effective treatment for PD patients at long term but it should be considered earlier in the course of P