1,228 research outputs found

    Temporal and spatial variations of the absolute reflectivity of Jupiter and Saturn from 0.38 to 1.7 ÎĽ\mum with PlanetCam-UPV/EHU

    Full text link
    We provide measurements of the absolute reflectivity of Jupiter and Saturn along their central meridians in filters covering a wide range of visible and near-infrared wavelengths (from 0.38 to 1.7 ÎĽ\mum) that are not often presented in the literature. We also give measurements of the geometric albedo of both planets and discuss the limb-darkening behavior and temporal variability of their reflectivity values for a period of four years (2012-2016). This work is based on observations with the PlanetCam-UPV/EHU instrument at the 1.23 m and 2.2 m telescopes in Calar Alto Observatory (Spain). The instrument simultaneously observes in two channels: visible (VIS; 0.38-1.0 ÎĽ\mum) and short-wave infrared (SWIR; 1.0--1.7 ÎĽ\mum). We obtained high-resolution observations via the lucky-imaging method. We show that our calibration is consistent with previous independent determinations of reflectivity values of these planets and, for future reference, provide new data extended in the wavelength range and in the time. Our results have an uncertainty in absolute calibration of 10--20\%. We show that under the hypothesis of constant geometric albedo, we are able to detect absolute reflectivity changes related to planetary temporal evolution of about 5-10\%.Comment: 13 pages, 18 figures, (in press

    Yield Components in a Signal Grass-Clitoria Mixture Grazed at Different Herbage Allowance

    Get PDF
    A Signal grass-Clitoria mixture provides good quality forage in the dry tropic of southern Mexico. However, its response in leaf and stem yields to grazing at different daily herbage allowances is not well documented. The objective of this study was to determine available and residual leaf and stem yields in a Signal grass (Brachiaria decumbens)-Clitoria (Clitoria ternatea) mixture grazed at different daily herbage allowance

    Quark stars and quantum-magnetically induced collapse

    Full text link
    Quark matter is expected to exist in the interior of compact stellar objects as neutron stars or even the more exotic strange stars, based on the Bodmer-Witten conjecture. Bare strange quark stars and (normal) strange quark-matter stars, those possessing a baryon (electron-supported) crust, are hypothesized as good candidates to explain the properties of a set of peculiar stellar sources as the enigmatic X-ray source RX J1856.5-3754, some pulsars as PSR B1828-11 and PSR B1642-03, and the anomalous X-ray pulsars and soft gamma-ray repeaters. In the MIT bag model, quarks are treated as a degenerate Fermi gas confined to a region of space having a vacuum energy density BbagB_{bag} (the Bag constant). In this note, we modif{}y the MIT Bag Model by including the electromagnetic interaction. We also show that this version of the MIT model implies the anisotropy of the Bag pressure due to the presence of the magnetic field. The equations of state of degenerate quarks gases are studied in the presence of ultra strong magnetic fields. The behavior of a system made-up of quarks having (or not) anomalous magnetic moment is reviewed. A structural instability is found, which is related to the anisotropic nature of the pressures in this highly magnetized matter. The conditions for the collapse of this system are obtained and compared to a previous model of neutron stars build-up on a neutron gas having anomalous magnetic moment.Comment: 11 pages, 2 figure

    Forage Yield and Quality of Signal Grass-Clitoria Mixture Grazed at Different Frequencies

    Get PDF
    A Signal grass-Clitoria mixture provides good quality forage in the dry tropic of southern Mexico. Grazing frequency is a management tool that determines yield, botanical components and quality of pastures. The objective of this study was to determine forage yield, quality and botanical components in a Signal grass (Brachiaria decumbens)-Clitoria (Clitoria ternatea) mixture when grazed at different frequencies

    Neosporosis en caninos y bovinos

    Get PDF
    La neosporosis es una enfermedad que puede afectar a una amplia gama de huéspedes entre ellos caninos, bovinos, ovinos, caprinos, búfalos, ciervos, equinos y especies carnívoras, incluidos géneros silvestres. Dicha enfermedad es causada por Neospora caninum, parásito protozoario (coccidio) que genera un quiste de tejido intracelular perteneciente a la familia Sarcocystidae. Los caninos son los huéspedes definitivos y los hospedadores intermedios más comunes son los bovinos. El ciclo de vida de N. caninum se caracteriza por ser hete- roxeno facultativo complejo, que involucra un hospedador cánido definitivo, donde ocurre la replicación sexual y una gama de hospedadores intermediarios donde tiene lugar la replica- ción asexual. Después de pasar estas fases el canino elimina ooquistes a través de las heces contaminando así el alimento del ganado y por ende infectando al mismo. La transmisión vertical es la principal vía de contagio de los bóvidos tanto domésticos como silvestres. El signo característico de la neosporosis de las vacas es el aborto. En terneros y cachorros puede causar daños neurológicos
    • …
    corecore