732 research outputs found
PPAK Integral Field Spectroscopy survey of the Orion Nebula: Data Release
We present a low-resolution spectroscopic survey of the Orion nebula which
data we release for public use. In this article, we intend to show the possible
applications of this dataset analyzing some of the main properties of the
nebula. We perform an integral field spectroscopy mosaic of an area of ~5' X 6'
centered on the Trapezium region of the nebula, including the ionization front
to the south-east. The analysis of the line fluxes and line ratios of both the
individual and integrated spectra allowed us to determine the main
characteristics of the ionization throughtout the nebula.The final dataset
comprises 8182 individual spectra, which sample each one a circular area of
\~2.7" diameter. The data can be downloaded as a single row-stacked spectra
fits file plus a position table or as an interpolated datacube with a final
sampling of 1.5"/pixel. The integrated spectrum across the field-of-view was
used to obtain the main integrated properties of the nebula, including the
electron density and temperature, the dust extinction, the Halpha integrated
flux (after correcting for dust reddening), and the main diagnostic line
ratios. The individual spectra were used to obtain line intensity maps of the
different detected lines. These maps were used to study the distribution of the
ionized hydrogen, the dust extinction, the electron density and temperature,
and the helium and oxygen abundance...Comment: 13 pages, 8 figures, accepted for publishing in Astronomy &
Astrophysic
Incidencia de aflatoxinas B1, B2, G1 y G2 en raciones alimenticias de ganado ovino, y de aflatoxinas M1 en leche de oveja (abstract)
Publishe
Bisphenol A induces coronary endothelial cell necroptosis by activating RIP3/CamKII dependent pathway.
Epidemiological studies link long term exposure to xenoestrogen Bisphenol-A to adverse cardiovascular effects. Our previous results show that BPA induces hypertension by a mechanism involving CamKII activation and increased redox stress caused by eNOS uncoupling. Recently, CamKII sustained activation has been recognized as a central mediator of programmed cell death in cardiovascular diseases, including necroptosis. However, the role of necroptosis in cardiac response to BPA had not yet been explored. Mice exposed to BPA for 16 weeks showed altered heart function, electrical conduction, and increased blood pressure. Besides, a stress test showed ST-segment depression, indicative of cardiac ischemia. The hearts exhibited cardiac hypertrophy and reduced vascularization, interstitial edema, and large hemorrhagic foci accompanied by fibrinogen deposits. BPA initiated a cardiac inflammatory response, up-regulation of M1 macrophage polarization, and increased oxidative stress, coinciding with the increased expression of CamKII and the necroptotic effector RIP3. In addition, cell death was especially evident in coronary endothelial cells within hemorrhagic areas, and Evans blue extravasation indicated a vascular leak in response to Bisphenol-A. Consistent with the in vivo findings, BPA increased the necroptosis/apoptosis ratio, the expression of RIP3, and CamKII activation in endothelial cells. Necrostatin-1, an inhibitor of necroptosis, alleviated BPA induced cardiac dysfunction and prevented the inflammatory and hemorrhagic response in mice. Mechanistically, silencing of RIP3 reversed BPA-induced necroptosis and CamKII activation in endothelial cells, while inhibition of CamKII activation by KN-93 had no effect on RIP3 expression but decreased necroptotic cell death suggesting that BPA induced necroptosis is mediated by a RIP 3/CamKII dependent pathway. Our results reveal a novel pathogenic role of BPA on the coronary circulation. BPA induces endothelial cell necroptosis, promotes the weakening of coronary vascular wall, which caused internal ventricular hemorrhages, delaying the reparative process and ultimately leading to cardiac dysfunction.post-print4043 K
Aflatoxinas B1, B2, G1 y G2 en productos destinados a la alimentación de vacuno lechero y presencia de aflatoxina M1 en leche (abstract)
Publishe
Lensing of ultra-high energy cosmic rays in turbulent magnetic fields
We consider the propagation of ultra high energy cosmic rays through
turbulent magnetic fields and study the transition between the regimes of
single and multiple images of point-like sources. The transition occurs at
energies around , where is the distance traversed by the
CR's with electric charge in the turbulent magnetic field of root mean
square strength and coherence length . We find that above only sources located in a fraction of a few % of the sky can reach large
amplifications of its principal image or start developing multiple images. New
images appear in pairs with huge magnifications, and they remain amplified over
a significant range of energies. At decreasing energies the fraction of the sky
in which sources can develop multiple images increases, reaching about 50% for
. The magnification peaks become however increasingly narrower and for
their integrated effect becomes less noticeable. If a uniform
magnetic field component is also present it would further narrow down the
peaks, shrinking the energy range in which they can be relevant. Below some kind of scintillation regime is reached, where many demagnified
images of a source are present but with overall total magnification of order
unity. We also search for lensing signatures in the AGASA data studying
two-dimensional correlations in angle and energy and find some interesting
hints.Comment: 30 pages, 16 figures, final version with minor change
Estudio in vitro del efecto de los ácidos fenólicos naturales sobre el crecimiento y producción de aflatoxinas por Aspergillus parasiticus: abstract
Publishe
Prevención y reducción de toxinas de Fusarium en cereales mediante el uso de ácidos fenólicos naturales: abstract
Publishe
Portland cement clinkers turned into garnets by spark plasma sintering
The feasibility of sintering Portland cement clinker powders by Spark Plasma Sintering (SPS) has been studied. Different SPSed compacts have been successfully obtained by this technique. The compacts have been characterized by means of X-Ray Diffraction, InfraRed spectroscopy, Scanning Electron Microscopy, Raman Microscopy and Vickers hardness. It is worth noting the finding that slight mineralogical variations in the starting compositions may induce dramatic changes, both in the final mineralogical composition and in the morphology, which can affect the properties of the SPSed compacts. Thus, we find that SPS allows artificial garnets to be obtained in the laboratory by applying pressures as low as 50Â MPa, while they are materials that would require much higher pressures in natural environments (2-10Â GPa). According to the Selsing model, it has been calculated that the material itself acts as a pressure amplifier at the micrometric level by a factor of 40-200 times. A new model describing the formation of garnets considering the emergence of two transitory eutectic liquids has been explained to justify this phenomenon. This result opens the door to looking for compositions for specific applications with high added value in the field (i.e. high hardness), mainly in the manufacturing of high-pressure (GPa) phases by applying relatively low pressures (MPa).The Authors acknowledge the financial support of the PID2020-119130 GB-I00 project funded by MCIN/AEI/10.13039/501100011033 and by CSIC under grant 201960E103. Thanks to the Official Laboratory for Testing of Construction Materials (LOEMCO, Getafe, Madrid, Spain) for free supply of the clinker sample
Mycoprev: elaboración de un código de buenas prácticas en la zona fronteriza España-Francia-Andorra como herramienta de prevención y control de micotoxinas en cereales: abstract
Publishe
Abundance determination in HII regions from spectra without the [OII]3727+3729 line
We suggest an empirical calibration for determination of oxygen and nitrogen
abundances and electron temperature in HII regions where the [OII]3727+3729
line (R_2) is not available. The calibration is based on the strong emission
lines of OIII, NII, and SII (NS calibration) and derived using the spectra of
HII regions with measured electron temperatures as calibration datapoints. The
NS calibration makes it possible to derive abundances for HII regions in nearby
galaxies from the SDSS spectra where R_2 line is out of the measured wavelength
range, but can also be used for the oxygen and nitrogen abundances
determinations in any HII region independently whether the nebular oxygen line
[OII]3727+3729 is available or not. The NS calibration provides reliable oxygen
and nitrogen abundances for HII regions over the whole range of metallicities.Comment: 6 pages, 4 figures, accepted for publication in the MNRA
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