4,214 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

    Real Hacienda y Negocios: García de Salcedo, Oficial Real en Lima (1532-1556)

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    In the context of the expansion of mercantile capitalism and the transformation of the State during the sixteenth century, this article focuses on the tensions between private interests and those of the Castilian Crown, particularly the work of the Royal Treasury (Real Hacienda) during the Conquest. It examines the case of one of the first royal officials in Peru. The violation of state norms by administrative agents of the monarchy has been treated by different authors from different perspectives. The reason for returning to this issue here consists in observing it as a strategy combined with other mechanisms of profit extraction in the process of the Conquest and in economic activities in commercial and agrarian sectors

    Nota sobre la pirofilita de Águilas (Murcia, SE de España)

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    Se hace un estudio previo del yacimiento de la pirofilita de Águilas (Provincia de Murcia, SE de España). Pirofilita, cuarzo, micas blancas y caolinita son los constituyentes de estas mineralizaciones filonianas que encajan enfisuras de las filitas del complejo Alpujárride. El origen de la pirofilita está relacionado con un proceso de metamorfismoregional de un material sedimentario rico en aluminio. La principal reacciónimplicada seria:1 Caolinita + 2 SiO2 = 1 Pirofilita + H2OSe contempla asimismo como posibilidad alternativa, un proceso de segregación metamórfica. Se dan datos ópticos, de análisis químico y de difracción de Rayos X

    Módulo online de cinemática como soporte a la enseñanza semipresencial de la Física en Ingeniería

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    Las nuevas tecnologías en materia de información y comunicación nos ofrecen las oportunidades para un mayor aprovechamiento de las herramientas y recursos, que permita mejorar el proceso de enseñanza-aprendizaje. Aprovechando las nuevas oportunidades que ofrecen medios como internet se diseñó y desarrolló un sistema hipermedial (website) denominado: programa SEHCP (Software Educativo Hipermedia Cinemática de la Partícula) como soporte al proceso de enseñanza-aprendizaje del tema Cinemática de la Partícula. El software fue utilizado por una muestra representativa de los tipos de destinatarios para los que fue diseñado y la consiguiente evaluación diagnóstica; la muestra estuvo conformada por alumnos de la asignatura Física Mecánica y alumnos del Curso Introductorio de la Facultad de Ingeniería de la Universidad de Carabobo-Venezuela

    Electromagnetic multipole moments of elementary spin-1/2, 1, and 3/2 particles

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    We study multipole decompositions of the electromagnetic currents of spin-1/2, 1, and 3/2 particles described in terms of Lagrangians designed to reproduce representation specific wave equations which are second order in the momenta and which emerge within the recently elaborated Poincar\'e covariant projector method. We calculate the electric multipoles of the above spins for the spinor, the four-vector, and the four-vector--spinor representations, attend to the most general non-Lagrangian spin-3/2 currents which are allowed by Lorentz invariance to be of third order in the momenta and construct the linear current equivalent of identical multipole moments of one of them. We conclude that such non-Lagrangian currents are not necessarily more general than the two-term currents emerging within the covariant projector method. We compare our results with those of the conventional Proca-, and Rarita-Schwinger frameworks. Finally, we test the representation dependence of the multipoles by placing spin-1 and spin-3/2 in the respective (1,0)\oplus(0,1), and (3/2,0)\oplus(0,3/2) single-spin representations. We observe representation independence of the charge monopoles and the magnetic dipoles, in contrast to the higher multipoles, which turn out to be representation dependent. In particular, we find the bi-vector (1,0)(0,1)(1,0)\oplus (0,1) to be characterized by an electric quadrupole moment of opposite sign to the one found in (1/2,1/2)(1/2,1/2), and consequently, to the WW boson. Our finding points toward the possibility that the ρ\rho meson could transform as part of an antisymmetric tensor with an a1a_{1} meson-like state as its representation companion.Comment: 27 pages, 2 figure

    Evaluation of the small ruminants cystic ovarian disease using transrectal ultrasonography

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    A transrectal ultrasonic method using a 7.5 MHz linear-array transducer was used in 194 ewes and 39 goats to study the characteristc of cystic ovaries. Cystic structures found on the ovaries include follicular cysts and luteinised cysts. Follicular cysts showed up as non-echogenic structures with a 1.5 ± 0.4 cm diameter. The cysts luteinised showed an echogenic rim of tissue, ranging from 2- 3 mm, around the cyst; the central cavity was 1±0.2 cm. In total, 4.1 percent of ewes and 5.1 percent of goats exhibited follicular cysts. Only 1 percent of ewes and 2.6 percent of goats showed luteinised cysts. In conclusion, the results demonstrated that transrectal ultrasonography provides a noninvasive form of visual access to the ovary from small ruminants, to evaluate pathological changes before the aplication of superovulation treatments and embryo transfer.Se ha realizado un estudio de las características ecográficas de estructuras quísticas ováricas en 194 ovejas y 39 cabras de diferentes razas y procedentes de distintas zonas geográficas, con el objeto de valorar la ecografía transrectal con sondas de alta resolución (7,5 MHz) como criterio de selección de animales destinados a programas de superovulación y recogida de embriones. Los quistes foliculares tenían una incidencia de presentación del 4,1 p.100 en las ovejas y del 5,1 p.100 en las cabras, presentándose ecográficamente con una morfología esférica anecoica de 1,5±0,4 cm de diámetro, con paredes finas y generalmente bien definidas. Los quistes luteínicos tuvieron una presentación del 1 p.100 en las ovejas y del 2,6 p.100 en las cabras. Ecográficamente se caracterizaban por presentar una cavidad central anecógena 1±0,2 cm, rodeada por un anillo ecogénico de 2-3 mm de espesor. No había diferencias significativas en la frecuencia de presentación de quistes ováricos entre ambas especies. Los resultados muestran que la ecografía transrectal con sondas de alta resolución permite la realización de un diagnóstico eficaz de la patología quística ovárica en los pequeños rumiantes, siendo recomendable esta metodología en la selección de hembras donantes y receptoras

    Expression of Novel Opsins and Intrinsic Light Responses in the Mammalian Retinal Ganglion Cell Line RGC-5. Presence of OPN5 in the Rat Retina

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    The vertebrate retina is known to contain three classes of photoreceptor cells: cones and rods responsible for vision, and intrinsically photoresponsive retinal ganglion cells (RGCs) involved in diverse non-visual functions such as photic entrainment of daily rhythms and pupillary light responses. In this paper we investigated the potential intrinsic photoresponsiveness of the rat RGC line, RGC-5, by testing for the presence of visual and non-visual opsins and assessing expression of the immediate-early gene protein c-Fos and changes in intracellular Ca2+mobilization in response to brief light pulses. Cultured RGC-5 cells express a number of photopigment mRNAs such as retinal G protein coupled receptor (RGR), encephalopsin/panopsin (Opn3), neuropsin (Opn5) and cone opsin (Opn1mw) but not melanopsin (Opn4) or rhodopsin. Opn5 immunoreactivity was observed in RGC-5 cells and in the inner retina of rat, mainly localized in the ganglion cell layer (GCL). Furthermore, white light pulses of different intensities and durations elicited changes both in intracellular Ca2+ levels and in the induction of c-Fos protein in RGC-5 cell cultures. The results demonstrate that RGC-5 cells expressing diverse putative functional photopigments display intrinsic photosensitivity which accounts for the photic induction of c-Fos protein and changes in intracellular Ca2+ mobilization. The presence of Opn5 in the GCL of the rat retina suggests the existence of a novel type of photoreceptor cell
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