77 research outputs found
Discovery of a weak magnetic field in the photosphere of the single giant Pollux
Aims: We observe the nearby, weakly-active single giant, Pollux, in order to
directly study and infer the nature of its magnetic field. Methods: We used the
new generation spectropolarimeters ESPaDOnS and NARVAL to observe and detect
circular polarization within the photospheric absorption lines of Pollux. Our
observations span 18 months from 2007-2009. We treated the spectropolarimetric
data using the Least-Squares Deconvolution method to create high
signal-to-noise ratio mean Stokes V profiles. We also measured the classical
activity indicator S-index for the Ca H&K lines, and the stellar radial
velocity (RV). Results: We have unambiguously detected a weak Stokes V signal
in the spectral lines of Pollux, and measured the related surface-averaged
longitudinal magnetic field Bl. The longitudinal field averaged over the span
of the observations is below one gauss. Our data suggest variations of the
longitudinal magnetic field, but no significant variation of the S-index. We
observe variations of RV which are qualitatively consistent with the published
ephemeris for a proposed exoplanet orbiting Pollux. The observed variations of
Bl appear to mimic those of RV, but additional data for this relationship to be
established. Using evolutionary models including the effects of rotation, we
derive the mass of Pollux and we discuss its evolutionary status and the origin
of its magnetic field. Conclusions: This work presents the first direct
detection of the magnetic field of Pollux, and demonstrates that ESPaDOnS and
NARVAL are capable of obtaining sub-G measurements of the surface-averaged
longitudinal magnetic field of giant stars, and of directly studying the
relationships between magnetic activity, stellar evolution and planet hosting
of these stars.Comment: 8 pages, 6 figures, accepted for publication in Astronomy and
Astrophysic
The energy of waves in the photosphere and lower chromosphere: III. Inversion setup for Ca II H spectra in local thermal equilibrium
The Ca II H line is one of the strongest lines in the solar spectrum and
provides continuous information on the solar atmosphere from the photosphere to
the lower chromosphere. We describe an inversion approach that reproduces
observed Ca II H spectra assuming LTE. We developed an inversion strategy based
on the SIR code. The approach uses a two-step procedure with an archive of
pre-calculated spectra to fit the line core and a subsequent iterative
modification to improve the fit in the line wing. Simultaneous spectra in the
630nm range can optionally be used to fix the continuum temperature. The method
retrieves 1D temperature stratifications neglecting lateral radiative
transport. LOS velocities are included by an empirical approach. An archive of
about 300.000 pre-calculated spectra is more than sufficient to reproduce the
line core of observed Ca II H spectra both in quiet Sun and in active regions.
The final thermodynamical stratifications match observed and best-fit spectra
to a level of about 0.5 (1) % of Ic in the line wing (core). Inversion schemes
based on pre-calculated spectra allow one a reliable and relatively fast
retrieval of solar properties from observed chromospheric spectra. The approach
can be easily extended to an 1D NLTE case by a simple exchange of the
pre-calculated archive spectra.Comment: 15 pages, 15 figures, accepted for publication in A&A. The animation
will only be provided in the A&A online sectio
The energy of waves in the photosphere and lower chromosphere: IV. Inversion results of Ca II H spectra
Most static 1D atmosphere models in the quiet Sun predict a rise of the gas
temperature at chromospheric layers, but numerical simulations only yield an
increase in the brightness temperature. We investigate the thermal structure in
the solar chromosphere as derived from an LTE inversion of Ca II H spectra in
QS and active regions. We investigate the temperature stratifications on
differences between magnetic and field-free regions in the QS, and between QS
and ARs. We determine the energy content of individual calcium bright grains
(BGs). The rms temperature fluctuations are below 100 K in the photosphere and
200-300 K in the chromosphere. The average temperature stratification in the QS
does not exhibit a clear chromospheric temperature rise, opposite to the AR
case. We find an energy content of about 7*10E18 J for BGs that repeat with a
cadence of about 160 secs. The precursors of BGs have a vertical extent of
about 200 km and a horizontal extent of about 1 Mm. The comparison of observed
with synthetic NLTE profiles confirms that the solar chromosphere in the QS
oscillates between an atmosphere in radiative equilibrium and one with a
moderate chromospheric temperature rise. Two-dimensional x-z temperature maps
exhibit nearly horizontal canopy-like structures with a few Mm extent around
photospheric magnetic field concentrations at a height of about 600 km. The
large difference between QS regions and ARs, and the better match of AR and
non-LTE reference spectra suggest that magnetic heating processes are more
important than commonly assumed. The temperature fluctuations in QS derived by
the LTE inversion do not suffice on average to maintain a stationary
chromospheric temperature rise. The spatially and vertically resolved
information on the temperature structure allows one to investigate in detail
the topology and evolution of the thermal structure in the lower solar
atmosphere.Comment: 16 pages, 16 figures + 1 page Appendix, accepted by A&
Atención Primaria y Trastornos Mentales y de l Comportamiento: una mirada exploratoria
Objetivo: Identificar la prevalencia de los problemas de comportamiento y salud mental que se relacionan con el primer nivel de atención a partir del análisis de las estadísticas de mortalidad a nivel nacional y en la provincia de Córdoba.
Metodología: La fuente analizada fue la Base de Datos de Mortalidad 2005 y 2006 del Ministerio de Salud de la Nación. Se calcularon Tasas de Mortalidad Bruta (TMB) y Específica (TME) según sexo, edad y causa por Trastornos Mentales y de Comportamiento (TMyC), Mortalidad Proporcional (MP) y la razón de tasas para país y provincia de Córdoba. Softwares SPSS e InfoStat.
Resultados: En el año 2005, la TMB fue similar entre país y provincia de Córdoba, mientras que las TME por causa y por sexo fueron inferiores en Córdoba. Los TMyC representaron el 0,74% de MP en Argentina, valores similares se registraron en 2006. Entre las muertes por TMyC, los Trastornos Mentales Orgánicos (TMO) y Trastornos Mentales y del Comportamiento debido al Uso de Alcohol (TMA), ocasionaron el 96% de las muertes registradas. Las muertes por TMO se acumulan a partir de los 60 años y las muertes por TMA se expresan como causa de muerte a partir de los 30 años. Las mujeres presentan una mayor incidencia en los TMO y los varones en los TMA. En la provincia de Córdoba se observaron valores similares a los registrados en el total del país.
Conclusión: La prevalencia de los TMyC observados en los registros de estadísticas vitales de Argentina y provincia de Córdoba se relacionan a patologías que están incluidas como necesidades en el primer nivel de atención
Vaccination of piglets at 2 and 3 weeks of age with Ingelvac PRRSFLEX® EU provides protection against heterologous field challenge in the face of homologous maternally derived antibodies
The Seventh Data Release of the Sloan Digital Sky Survey
This paper describes the Seventh Data Release of the Sloan Digital Sky Survey
(SDSS), marking the completion of the original goals of the SDSS and the end of
the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most
of the roughly 2000 deg^2 increment over the previous data release lying in
regions of low Galactic latitude. The catalog contains five-band photometry for
357 million distinct objects. The survey also includes repeat photometry over
250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A
coaddition of these data goes roughly two magnitudes fainter than the main
survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2
in the Northern Galactic Cap, closing the gap that was present in previous data
releases. There are over 1.6 million spectra in total, including 930,000
galaxies, 120,000 quasars, and 460,000 stars. The data release includes
improved stellar photometry at low Galactic latitude. The astrometry has all
been recalibrated with the second version of the USNO CCD Astrograph Catalog
(UCAC-2), reducing the rms statistical errors at the bright end to 45
milli-arcseconds per coordinate. A systematic error in bright galaxy photometr
is less severe than previously reported for the majority of galaxies. Finally,
we describe a series of improvements to the spectroscopic reductions, including
better flat-fielding and improved wavelength calibration at the blue end,
better processing of objects with extremely strong narrow emission lines, and
an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor
correction
Chemical Tagging in the Sdss-Iii/Apogee Survey: New Identifications of Halo Stars with Globular Cluster Origins
We present new identifications of five red giant stars in the Galactic halo with chemical abundance patterns that indicate they originally formed in globular clusters. Using data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) Survey available through Sloan Digital Sky Survey (SDSS) Data Release 12, we first identify likely halo giants, and then search those for the well-known chemical tags associated with globular clusters, specifically enrichment in nitrogen and aluminum. We find that 2% of the halo giants in our sample have this chemical signature, in agreement with previous results. Following the interpretation in our previous work on this topic, this would imply that at least 13% of halo stars originally formed in globular clusters. Recent developments in the theoretical understanding of globular cluster formation raise questions about that interpretation, and we concede the possibility that these migrants represent a small fraction of the halo field. There are roughly as many stars with the chemical tags of globular clusters in the halo field as there are in globular clusters, whether or not they are accompanied by a much larger chemically untaggable population of former globular cluster stars
Genomic Characterization of Host Factors Related to SARS-CoV-2 Infection in People with Dementia and Control Populations: The GR@ACE/DEGESCO Study
Emerging studies have suggested several chromosomal regions as potential host genetic factors involved in the susceptibility to SARS-CoV-2 infection and disease outcome. We nested a COVID-19 genome-wide association study using the GR@ACE/DEGESCO study, searching for susceptibility factors associated with COVID-19 disease. To this end, we compared 221 COVID-19 confirmed cases with 17,035 individuals in whom the COVID-19 disease status was unknown. Then, we performed a meta-analysis with the publicly available data from the COVID-19 Host Genetics Initiative. Because the APOE locus has been suggested as a potential modifier of COVID-19 disease, we added sensitivity analyses stratifying by dementia status or by disease severity. We confirmed the existence of the 3p21.31 region (LZTFL1, SLC6A20) implicated in the susceptibility to SARS-CoV-2 infection and TYK2 gene might be involved in COVID-19 severity. Nevertheless, no statistically significant association was observed in the COVID-19 fatal outcome or in the stratified analyses (dementia-only and non-dementia strata) for the APOE locus not supporting its involvement in SARS-CoV-2 pathobiology or COVID-19 prognosis
Recommendations for dental care in a situation of SARS-COV-2 pandemic and post-pandemic
La Odontología es una de las cinco profesiones más expuestas a contraer COVID-19, debido a la exposición -durante las actividades clínicas-al contacto con sangre, saliva, aerosoles, manipulación de sustancias potencialmente nocivas. El conocimiento de los riesgos propios de su entorno tiene como objetivo último evitar que los odontólogos y las personas vinculadas a la práctica profesional provoquen -por desconocimiento, inobservancia o falta de apropiación de los saberes-contagios y/o impactos desfavorables para ellos y el ambiente. Al minimizar el riesgo y la posibilidad de infecciones cruzadas se evitarán mayores contagios, en el contexto actual, sin desatender las emergencias odontológicas.publishedVersionFil: Allende Posse, María. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Arévalo, Paola. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Bojanich, Alejandra. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Bono, A. Colegio Odontológico de la Provincia de Córdoba; Argentina.Fil: Busleiman, Federico. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Castillo, Beatriz. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Castillo, Graciela. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Castillo, María Cristina. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Ermoli, J. Colegio Odontológico de la Provincia de Córdoba; Argentina.Fil: Flores, N. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Gigena, Pablo. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Girardi, Mónica. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Gutvay, Ada. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Herrera, Analía. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Huespe Rico, Verónica. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Irazuzta, María Laura. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Martínez, Dora. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Moriconi, E. Provincia de Córdoba. Ministerio de Ciencia y Tecnología; Argentina.Fil: Pereyra, María Eugenia. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Priotto, Elba. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Raya Tonetti, G. Provincia de Córdoba. Ministerio de Ciencia y Tecnología; Argentina.Fil: Rezzónico, M. S. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Scatena, Gabriela. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Vera, Mónica. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina.Fil: Zorrilla, Inés. Universidad Nacional de Córdoba. Facultad de Odontología. Equipo de Investigación en Higiene y Bioseguridad y Centro de Bioseguridad; Argentina
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