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

Estudio geomorfológico de las terrazas fluviales cuaternarias del Valle del Tajo (sector Aranjuez-Toledo)

[Resumen] En esta comunicación se analiza la morfología de los distintos niveles de terraza que pertenecientes al sistema fluvial Tajo-Jarama existen en el tramo comprendido entre Aranjuez y Toledo; igualmente se estudian las características sedimentológicas de los aluviones asociados a estas terrazas, así como otras formaciones detríticas de diferentes épocas geológicas que se advierten en esta zona de la Submeseta Sur. De esta manera se continuan las observaciones realizadas por nosotros hace unos años en las terrazas del Tajo, aguas arriba de Aranjuez y hasta las inmediaciones del embalse de Almoguera, en la provincia de Guadalajara (GONZALEZ MARTIN y ASENSIO AMOR, 1979), así como las investigaciones dedicadas a las deformaciones pseudo-tectónicas que en ocasiones afectan a los conjuntos sedimentarios fluviales (GONZALEZ MARTIN y ASENSIO AMOR, 1980)[Resumé] On étude dans ce travail les caracteres géomorphologiques des différents niveaux de terrasses dans la vallée du Tajo-Jarama (Aranjuez-Toledo). En meme temps, on analyse les caractéristiques sédimentologiques des materiaux associés aux ces formes morphologiques et des autres formations détritiques des ages tertiaires et quaternaires. De cette façon nous poursuivons les observations faites, il y a quelque temps, pour nous meme. D'un cote, le systeme de terrasses dans l'amont de Aranjuez et jusqu'a les environs de Almoguera (GONZALEZ MARTIN y ASENSIO AMOR, 1979). De l'autre, les recherches consacrées aux déformations pseudo-tectoniques visibles quelques fois dans ces ensambles sédimentaires quaternaires (GONZALEZ MARTIN y ASENSIO AMOR, 1980)

Synthesis of periglacial processes in Galicia (Spain)

[Resumen] En esta comunicación, de carácter bibliográfico, los autores incluyen con un breve comentario las publicaciones que hacen referencia a fenómenos periglaciares en Galicia[Abstract] In this note, of bibliographical characteristic, the authors enclose with a brief commentary about the periglacial geomorphology publications in the country of the Galicia

Synthesis of geomorphological processes in the «Galaico-Astur» Bounds

[Resumen] En este trabajo se analizan los distintos procesos geomorfológicos que han intervenido en el modelado de formas en el sector Galaico-Astur. Actualmente, los procesos de índole dinámica (fluviales, marinos, etc.) y los edafogenéticos son los que muestran una mayor incidencia aunque condicionados por la influencia de factores estructurales y de orden climático; buena parte de su eficacia está favorecida, igualmente, por las acciones antrópicas. En lo que respecta a los procesos antiguos, éstos vuelven a revestir su mayor importancia dentro de la tipología dinámica; no obstante, ellos presentan una originalidad más contrastada al haber actuado bajo condiciones climáticas más rigurosas y extremas, y con niveles de base marinos muy diferentes.[Abstract] In this synthesis we analyse the several geomorphological processes that have contributed to model the landforms in the «Galaico-Astur» area. At present, the dynamic nature processes (fluvial, marine, etc.) show a greater incidence though they are conditioned by the inf1uén:~ of climatic and structural factors; most of their efficacy results also increased by antrhopactions. As regards the ancient processes, those of dynamic type are again the more important ones. Furthermore, they appear more stressed because their action was performed on different sea-marine levels and their effects were reinforced by extreme and severe climatic conditions

¿Es posible la clasificación de individuos perinatales a partir de caracteres objetivos?

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

Bosonization on a lattice: The emergence of the higher harmonics

6 págs.; 2 figs.A general and transparent procedure to bosonize fermions placed on a lattice is presented. Harmonics higher than kF in the one-particle Green function are shown to appear due to the compact character of real electron bands. Quantitative estimations of the role of higher harmonics are made possible by this bosonization technique. © 1995 The American Physical Society.J.F. was supported by DEYCIT Project No. PB93-1248.Peer Reviewe

Identificando actividades de matematización horizontal y vertical en un proceso de clasificación

La noción de matematización progresiva se expresa través de una secuencia generada por dos tipos de actividad matemática relacionadas reflexivamente: la matematización horizontal y la vertical (Treffers, 1987). Aunque, frecuentemente, la matematización horizontal se describe a través de la transformación de una situación problemática en un problema matemático propiamente dicho, en nuestro trabajo utilizaremos este concepto en un sentido más amplio que nos permitirá incluir situaciones de partida que sean de naturaleza ya matemática (Rasmussen, Zandieh, King & Teppo, 2005). Las actividades que pueden ser identificadas cuando se produce la matematización horizontal y la matematización vertical han sido descritas por Üzel y Mert Uyangör (2006)

Evaluation and optimization of the Sysmex UF1000i system for the screening of urinary tract infection in primary health care elderly patients

Objective Urinary tract infections (UTIs) are a common problem in the elderly population. Urine culture is still considered the "gold standard" to diagnose infection in this population. However, urine cultures are laborious and costly, and most samples will yield no growth. Methods An evaluation was made of the Sysmex UF-1000i flow cytometer as a screening tool for UTI in an elderly population older than 65 years who lived in the community, using 346 urine samples submitted for culture. Results The Receiver Operating Characteristic (ROC) analysis showed a significant difference (P < 0.01) between 0.98 bacteria area under the curve value and 0.82 of white blood cells (WBC). The combination of both counts for screening did not show any improvement in specificity or sensitivity. According to our data, the use of a single cut-off point of 200 bacteria/μL is suggested, in which the sensitivity and specificity were 99.11% and 91.59%, respectively, with a NPV of 99.49%. Moreover, this cut-off value could avoid 60.24% of the samples to be cultured, with a minimal false negative results rate of 0.87%. Conclusions The stratification of age groups stratification helps in selecting a more adjusted Sysmex UF1000i cut-off limit, leading to an improvement in the screening parameters that would imply a better management of these infections, as well as a high reduction in the workload and cost savings