844 research outputs found
Jurisprudencia civil
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Formation of S0 galaxies through mergers. Evolution in the Tully-Fisher relation since
(Abridged version) We explore whether a scenario that combines an origin by
mergers at 1.8-1.5 with a subsequent passive evolution of the resulting
S0 remnants since 0.8-1 is compatible with observational data of S0s in
the Tully-Fisher relation (TFR). We studied a set of major and minor merger
experiments from the GalMer database that generate massive S0 remnants. We
analysed the location of these remnants in the photometric and stellar TFRs
assuming that they correspond to galaxies. We then estimated their
evolution in these planes over the last 7 Gyr. The results were compared with
data of real S0s and spirals at different redshifts. We also tested how the use
of Vcirc or Vrot,max affects the results. We found that just after 1-2
Gyr of coalescence, major mergers generate S0 remnants that are outliers of the
local photometric and stellar TFRs at . After 4-7 Gyr of
passive evolution in isolation, the S0 remnants move towards the local TFR,
although the initial scatter among them persists. This scatter is sensitive to
the indicator used for the rotation velocity: Vcirc values yield a lower
scatter than when Vrot,max values are considered instead. In the planes
involving Vrot,max, a clear segregation of the S0 remnants in terms of the
spin-orbit coupling of the model is observed, in which the remnants of
retrograde encounters overlap with local S0s hosting counter-rotating discs.
The location of the S0 remnants at agrees well with the observed
distribution of local S0 galaxies in the -, Vcirc- and
Vrot,max- planes. Thus, massive S0 galaxies may have been formed
through major mergers that occurred at high redshift and have later evolved
towards the local TFR through passive evolution in relative isolation, a
mechanism that would also contribute to the scatter observed in this relation.Comment: 19 pages, 15 figures. Accepted for publication in A&
Formation of S0 galaxies through mergers. Bulge-disc structural coupling resulting from major mergers
Observations reveal a strong structural coupling between bulge and disc in S0
galaxies, which seems difficult to explain if they have formed from supposedly
catastrophic events such as major mergers. We face this question by quantifying
the bulge-disc coupling in dissipative simulations of major and minor mergers
that result in realistic S0s. We have studied the dissipative N-body binary
merger simulations from the GalMer database that give rise to realistic,
relaxed E/S0 and S0 remnants (67 major and 29 minor mergers). We simulate
surface brightness profiles of these S0-like remnants in the K-band, mimicking
typical observational conditions, to perform bulge-disc decompositions
analogous to those carried out in real S0s. The global bulge-disc structure of
these remnants has been compared with real data, and they distribute in the B/T
- r_e - h_d parameter space consistently with real bright S0s, where B/T is the
bulge-to-total luminosity ratio, r_e is the bulge effective radius, and h_d is
the disc scalelength. Major mergers can rebuild a bulge-disc coupling in the
remnants after having destroyed the structures of the progenitors, whereas
minor mergers directly preserve them. Remnants exhibit B/T and r_e/h_d spanning
a wide range of values, and their distribution is consistent with observations.
Many remnants have bulge Sersic indices ranging 1<n<2, flat appearance, and
contain residual star formation in embedded discs, a result which agrees with
the presence of pseudobulges in real S0s. Contrary to the popular view, mergers
(and in particular, major events) can result in S0 remnants with realistically
coupled bulge-disc structures in less than ~3 Gyr. In conclusion, the
bulge-disc coupling and the presence of pseudobulges in real S0s cannot be used
as an argument against the possible major-merger origin of these galaxies.Comment: 23 pages, accepted for publication in Astronomy and Astrophysics
(version after minor language corrections
Evaluación de estrategias de afrontamiento desde la perspectiva de la interacción persona-situación: desarrollo y validación del Cuestionario Situado de Afrontamiento para Adultos
Background: Although coping strategies are considered to contribute to resilience to adversity, their use is not stable, but varies depending on the specifi c adversity. However, to date, most of the questionnaires assessing coping do not consider its situational character. The objective of this study is to develop and validate the Situated Coping Questionnaire
for Adults (SCQA), which assesses coping in the face of fi ve different kinds of adverse contexts to take into account its situational dimension. Methods: A total of 430 Spanish adults (256 from the general population, 77 people suffering from cancer or HIV, and 97 parents of children with cancer or developmental problems) completed the SCQA and two
resilience questionnaires (the Brief Resilience Scale and the 10-item Connor-Davidson Resilience Scale) for validation purposes. Results: Confirmatory factor analyses showed the superiority of the personsituation model; the situation infl uences the degree to which people use specific coping strategies; however, coping is also stable to some extent.
Regression analyses showed that coping strategies contribute to predict resilience, supporting the validity of the SCQA. The questionnaire and its sub-scales showed adequate reliability. Conclusion: The SCQA is deemed a reliable and valid means of situated coping assessment for use in several populationsAntecedentes: aunque se considera que las estrategias de afrontamiento contribuyen a la resiliencia frente a la adversidad, su uso no es estable, sino que varía en función
del tipo de adversidad. Sin embargo, la mayoría de los cuestionarios de afrontamiento no tienen en cuenta su carácter situacional. El objetivo de este estudio es desarrollar y validar el Cuestionario Situado de Afrontamiento para Adultos (SCQA por sus siglas en inglés), que evalúa afrontamiento en cinco contextos diferentes. Método: 430 adultos españoles (256 población general, 77 personas con VIH o cáncer y 97 padres de niños con cáncer
o problemas de desarrollo) completaron el SCQA y dos cuestionarios de resiliencia (Brief Resilience Scale y Connor-Davidson Resilience Scale-10) con propósitos de validación. Resultados: los análisis factoriales confirmatorios mostraron la superioridad del modelo persona-situación; la situación influye en la utilización de distintas estrategias de afrontamiento, sin embargo, estas también son relativamente estables. Los análisis de
regresión mostraron que las estrategias de afrontamiento contribuyeron a predecir resiliencia en la dirección esperada, aportando evidencias de validez. El cuestionario y sus subescalas mostraron adecuada fiabilidad. Conclusión: el SCQA ha mostrado ser un cuestionario fiable y válido para evaluar afrontamiento desde una perspectiva situacional y en múltiples poblacione
Evolution induced by dry minor mergers onto fast-rotator S0 galaxies
We analysed collisionless N-body simulations of intermediate and minor dry
mergers onto S0s to test whether these mergers can generate S0 galaxies with
kinematics intermediate between fast and slow rotators. We find that minor
mergers induce a lower decrease of the global rotational support than
encounters of lower mass ratios, which results in S0s with properties
intermediate between fast and slow rotators. The resulting remnants are
intrinsically more triaxial, less flattened, and span the whole range of
apparent ellipticities up to . They do not show
lower apparent ellipticities in random projections than initially; on the
contrary, the formation of oval distortions and the disc thickening increase
the percentage of projections at . In the
experiments with S0b progenitor galaxies, minor mergers tend to spin up the
bulge and to decrease slightly its intrinsic ellipticity, whereas in the cases
of primary S0c galaxies they keep the rotational support of the bulge nearly
constant and decrease significantly its intrinsic ellipticity. The remnant
bulges remain nearly spherical (), but exhibit a wide range
of triaxialities (). In the plane of global anisotropy of
velocities () vs. intrinsic ellipticity (),
some of our models extend the linear trend found in previous major merger
simulations towards higher values, while others
depart from it. This is consistent with the wide dispersion exhibited by real
S0s in this diagram compared with ellipticals, which follow the linear trend
drawn by major merger simulations. The different trends exhibited by
ellipticals and S0 galaxies in the - diagram may
be pointing to the different role played by major mergers in the build-up of
each morphological type.Comment: Corrected typos. 20 pages, 14 figures. Accepted for publishing in A&
Infraestructura de alta disponibilidad en redes desplegables
El propósito del presente Trabajo de Fin de Grado es realizar un análisis de las redes desplegables de alta disponibilidad del Ejército de Tierra. Las redes desplegables en el Ejército de Tierra adolecen de falta de redundancia tanto en las conexiones como en los equipos que conforman la red, esto hace a las redes desplegables más sensibles y vulnerables. Por ello en este trabajo se buscan formas de solucionar los problemas que aparecen en los Nodos de SIMACET en su versión 5. La metodología seguida en este TFG ha sido, primeramente, realizar un estudio sobre los componentes del nodo y, de forma simultánea, realizar entrevistas con los administradores con el fin de detectar y recopilar las vulnerabilidades, si es que poseen alguna, de los diferentes equipos. Posteriormente se han buscado soluciones a los problemas existentes, así como mejoras para conseguir que sean más operativos. Finalmente, se ha realizado un estudio de costes con el fin de cuantificar las mejoras. La conclusión obtenida en el siguiente trabajo es que a pesar de buscar una reducción de medios y por tanto de costes en los nodos, las necesidades operativas y tácticas a las que se enfrenta el Ejército de Tierra hacen necesaria la incorporación de un segundo Nodo SIMACET v.5 de menor entidad para ser usado como respaldo, así como pequeñas modificaciones en los equipos.<br /
THE INTERMEDIATE-MASS EMBEDDED CLUSTER GM 24 REVISITED: NEW INFRARED AND RADIO OBSERVATIONS*
New and archived high-resolution infrared (IR; 1-20 μm) and radio-continuum images of the isolated embedded cluster and associated compact H II region, GM 24, are presented and measured photometrically. The nucleus of the complex is Irs 3, or IRAS 17136-3617, located at the densest part of the molecular cloud. This object is composed of at least three compact near-IR sources (A, B, and C) that are the most luminous and massive young stellar components and provide most of the ionizing energy to the cometary-shaped radio H II region. The 3.6 cm radio map shows a complex structure with an extended emission peak and two very compact components very close to Irs 3A. Large inhomogeneities in the dust density within the nebula cause considerably different morphologies in the observed emission of hydrogen recombination lines, namely Paβ, Brγ, and Brα. No H2 line emission at 2.12 μm was detected. The embedded IR cluster is found to contain more than 100 members within a radius of around 40'', which corresponds to 0.39 pc. The total stellar mass is estimated to be ≥250 M ☉. The extinction to the nearby edge of the cluster is determined to be AV = 13, though a number of sources, including Irs 3, are reddened by AV > 50. A fraction of near-IR sources, mainly in the periphery of the cluster, are main-sequence A-B-type stars, while a large fraction (~50%) of the detected members show significant IR excesses, including several Class I young stellar objects with luminosities ranging from a few solar luminosities near our sensitivity limit, to 1.5 × 105 L ☉, the derived luminosity of Irs 3
The effect of spray‐dried porcine plasma on gilthead seabream (Sparus aurata) intestinal microbiota
The effect of spray‐dried porcine plasma (SDPP) on the intestinal histological organization and autochthonous microbiota composition was evaluated in Sparus aurata. Fish were fed a basal diet (51 g/kg protein, 17 g/kg fat, 20.6 MJ/kg gross energy) and a diet containing 3 g/kg SDPP for 95 days (initial body weight, BW = 9.5 ± 0.2g, mean ± SD). The inclusion of SDPP promoted growth (p .05) between both groups. Intestinal microbiota was dominated by Proteobacteria (>85%) and Firmicutes (5%–12%), whereas Bacteroidetes never represented more than 1.5%. γ‐Proteobacteria, and Bacilli and Clostridia were the predominant classes. The short administration of SDPP (20 days) resulted in changes in microbiota diversity and richness associated with an increase in the sequences of the genus Lactobacillus and to a decrease in the genus Vibrio, whereas these changes were reverted at 95 days. Intestinal goblet cell density was not correlated to microbiota diversity and richness changes rather than to the immunostimulatory effect of the SDPP.info:eu-repo/semantics/acceptedVersio
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