The central parsecs of M87: jet emission and an elusive accretion disc

We present the first simultaneous spectral energy distribution (SED) of M87 core at a scale of 0.4 arcsec ($\sim 32\, \rm{pc}$) across the electromagnetic spectrum. Two separate, quiescent, and active states are sampled that are characterized by a similar featureless SED of power-law form, and that are thus remarkably different from that of a canonical active galactic nuclei (AGN) or a radiatively inefficient accretion source. We show that the emission from a jet gives an excellent representation of the core of M87 core covering ten orders of magnitude in frequency for both the active and the quiescent phases. The inferred total jet power is, however, one to two orders of magnitude lower than the jet mechanical power reported in the literature. The maximum luminosity of a thin accretion disc allowed by the data yields an accretion rate of $< 6 \times 10^{-5}\, \rm{M_\odot \, yr^{-1}}$, assuming 10% efficiency. This power suffices to explain M87 radiative luminosity at the jet-frame, it is however two to three order of magnitude below that required to account for the jet's kinetic power. The simplest explanation is variability, which requires the core power of M87 to have been two to three orders of magnitude higher in the last 200 yr. Alternatively, an extra source of power may derive from black hole spin. Based on the strict upper limit on the accretion rate, such spin power extraction requires an efficiency an order of magnitude higher than predicted from magnetohydrodynamic simulations, currently in the few hundred per cent range.Comment: 18 pages, 6 figures. Accepted for publication in MNRA

Long- term effects of fire and three fire-fighting chemicals on a soil-plant system.

The impacts of fire and fire-fighting chemicals (FFC) on soil properties and the soil-plant system were evaluated five years after treatment application. Unburnt soils (US) were compared with burnt soils treated with water alone (BS) or with foaming agent (BS+Fo), Firesorb polymer (BS+Fi), or ammonium polyphosphate (BS+Ap). Soils (0-2 cm depth) and foliar material (Ulex micranthus, Pterospartum tridentatum, Erica umbellata and Pinus pinaster) were analysed for total-C, total-N, δ 15N, nutrients (soil-available; plant-total), pH and inorganic-N (soils) and vegetation cover and height. No long-term effects of FFC on soil properties were found except for pH (BS+Fo > BS+Ap), inorganic-N and P (BS+Ap > other treatments). BS+Ap plants usually showed higher values of δ 15N, N, P and Na, but less K. Soil coverage by Pterospartum and Ulex was higher in BS+Ap than in other treatments, while the opposite was observed for Erica; shrubs were always taller in BS+Ap. After 3 years of growth, the size of pine seedlings followed the order BS+Ap > US > other treatments. Foliar N and P, scrub regeneration and growth of pines showed the long-term fertilizing effect of ammonium polyphosphate, although the second highest pine mortality was found in the BS+Ap treatment. The foaming agent did not affect vegetation cover, and Firesorb had no noticeable effect on shrubs but the highest pine mortality.Peer reviewe

Alteraciones de la superficie del cuerpo vertebral en una población medieval de Logroño (s. XI y XII)

X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200

Interest and Applicability of Meta-Heuristic Algorithms in the Electrical Parameter Identification of Multiphase Machines

Multiphase machines are complex multi-variable electro-mechanical systems that are receiving special attention from industry due to their better fault tolerance and power-per-phase splitting characteristics compared with conventional three-phase machines. Their utility and interest are restricted to the definition of high-performance controllers, which strongly depends on the knowledge of the electrical parameters used in the multiphase machine model. This work presents the proof-of-concept of a new method based on particle swarm optimization and standstill time-domain tests. This proposed method is tested to estimate the electrical parameters of a five-phase induction machine. A reduction of the estimation error higher than 2.5% is obtained compared with gradient-based approaches.Plan Estatal 2013-2016 Retos - Proyectos I+D+i DPI2013-44278-RPlan Estatal 2013-2016 Retos - Proyectos I+D+i DPI2016-76144-

MALDI_TOF mass spectrometry does not differentiate between brucella species, suggesting that the may represent a single species

Comunicaciones a congreso

ÁREA DE ACTIVIDAD Y COMPORTAMIENTO DEL LAGARTO Tropidurus hispidus (Spix 1825) (SAURIA-TROPIDURIDAE) EN CERRO COLORADO. CUMANÁ, ESTADO SUCRE, VENEZUELA

El área de actividad y algunas pautas en el comportamiento de adultos del lagarto Tropidurus hispidus fueron estudiados en Cerro Colorado, estado Sucre, Venezuela. Para calcular el área de actividad se utilizaron los métodos del polígono convexo y el de la elipse. El área de actividad en los machos (334,81 m2) resultó ser cualitativamente mayor que el de las hembras (105,85 m2), no se detectaron diferencias significativas entre ambas. En las hembras entre el área de actividad y la masa corporal, se registró una relación negativa y significativa, pero no así en los machos. Se identificaron ocho pautas de posición, cinco de mantenimiento y siete de desplazamiento.   PALABRAS CLAVE: Tropidurus hispidus, área de actividad, comportamiento, noreste, Venezuela.   ABSTRACT Home range and other patterns of behavior of adult lizards, Tropidurus hispidus, were studied in their habitat in Cerro Colorado, state of Sucre, Venezuela. The minimum convex polygon method and that of the ellipse were used to calculate the lizards’ area of activity. Mean home range for males resulted qualitatively larger (334.81 m2) than that of females (105.85 m2). No significant differences were found. Home range negatively correlated with body mass in females but not in males. Twenty behavioral patterns were identified, eight of position, five of maintenance, and seven of locomotion.   KEY WORDS: Tropidurus hispidus, home range, behavior, northeastern Venezuela