1,228 research outputs found
Temporal and spatial variations of the absolute reflectivity of Jupiter and Saturn from 0.38 to 1.7 m with PlanetCam-UPV/EHU
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 m) 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 m) and short-wave infrared (SWIR; 1.0--1.7 m). 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
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
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
(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
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
La neosporosis es una enfermedad que puede afectar a una amplia gama de huĂ©spedes entre ellos caninos, bovinos, ovinos, caprinos, bĂşfalos, ciervos, equinos y especies carnĂvoras, incluidos gĂ©neros 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 huĂ©spedes 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 replicaciĂłn sexual y una gama de hospedadores intermediarios donde tiene lugar la replica- ciĂłn asexual. DespuĂ©s de pasar estas fases el canino elimina ooquistes a travĂ©s de las heces contaminando asĂ el alimento del ganado y por ende infectando al mismo. La transmisiĂłn vertical es la principal vĂa de contagio de los bĂłvidos tanto domĂ©sticos como silvestres. El signo caracterĂstico de la neosporosis de las vacas es el aborto. En terneros y cachorros puede causar daños neurolĂłgicos
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