6,565 research outputs found
The evolution of H{\sc ii} galaxies: Testing the bursting scenario through the use of self-consistent models
We have computed a series of realistic and self-consistent models of the
emitted spectra of H{\sc ii} galaxies. Our models combine different codes of
chemical evolution, evolutionary population synthesis and photoionization. The
emitted spectrum of H{\sc ii} galaxies is reproduced by means of the
photoionization code CLOUDY, using as ionizing spectrum the spectral energy
distribution of the modelled H{\sc ii} galaxy, which in turn is calculated
according to a Star Formation History (SFH) and a metallicity evolution given
by a chemical evolution model that follows the abundances of 15 different
elements. The contribution of emission lines to the broad-band colours is
explicitly taken into account.
The results of our code are compared with photometric and spectroscopic data
of H{\sc ii} galaxies. Our technique reproduces observed diagnostic diagrams,
abundances, equivalent width-colour and equivalent width-metallicity relations
for local H{\sc ii} galaxies.Comment: 13 figures and 2 tables, accepted for publication in MNRAS Main
Journa
Changes in Access to Health Services of the Immigrant and Native-Born Population in Spain in the Context of Economic Crisis
Aim: To analyze changes in access to health care and its determinants in the immigrant and native-born populations in Spain, before and during the economic crisis. Methods: Comparative analysis of two iterations of the Spanish National Health Survey (2006 and 2012). Outcome variables were: unmet need and use of different healthcare levels; explanatory variables: need, predisposing and enabling factors. Multivariate models were performed (1) to compare outcome variables in each group between years, (2) to compare outcome variables between both groups within each year, and (3) to determine the factors associated with health service use for each group and year. Results: unmet healthcare needs decreased in 2012 compared to 2006; the use of health services remained constant, with some changes worth highlighting, such as the decline in general practitioner visits among autochthons and a narrowed gap in specialist visits between the two populations. The factors associated with health service use in 2006 remained constant in 2012. Conclusion: Access to healthcare did not worsen, possibly due to the fact that, until 2012, the national health system may have cushioned the deterioration of social determinants as a consequence of the financial crisis. Further studies are necessary to evaluate the effects of health policy responses to the crisis after 2012
Star Formation and Selective Dust Extinction in Luminous Starburst Galaxies
We investigate the star formation and dust extinction properties of very
luminous infrared galaxies whose spectra display a strong Hdelta line in
absorption and a moderate [OII] emission (e[a] spectrum). This spectral
combination has been suggested to be a useful method to identify dusty
starburst galaxies at any redshift on the basis of optical data alone. We
compare the average e(a) optical spectrum with synthetic spectra that include
both the stellar and the nebular contribution, allowing dust extinction to
affect differentially the stellar populations of different ages. We find that
reproducing the e(a) spectrum requires the youngest stellar generations to be
significantly more extinguished by dust than older stellar populations, and
implies a strong ongoing star formation activity at a level higher than in
quiescent spirals. A model fitting the optical spectrum does not necessarily
produce the observed FIR luminosity and this can be explained by the existence
of stellar populations which are practically obscured at optical wavelengths.
Models in which dust and stars are uniformly mixed yield a reddening of the
emerging emission lines which is too low compared to observations: additional
foreground reddening is required.Comment: 17 pages, 4 Postscript figures, ApJ in pres
Planificacion y desarrollo de la Industria Maquimsa
140 p.La gran competencia industrial que se esta viviendo, ha creado mentalidad en los empresarios, de resguardar al máximo su capital invertido, ya sea en maquinaria, equipos, edificios, etc. y alarga la vida útil de cada uno de ellos, pare así poder bajar sus costos de producción. Como también, de llevar una planificación y un control seguro de todos los procesos o actividades que se desean realizar, de tal manera de poder controlar cada elemento que pueda producir perdidas. Para llevar a cabo tales planes, es necesario tener un control adecuado de la aplicación de factores tan importantes como son la seguridad industrial, el control de perdidas y la manutención. Tomando en cuenta los factores ya analizados, se ha creado conveniente centralizar esta tesis en estos temas de vital importancia para la exigencia en el mercado y el avance a tecnología y si bien es cierto para nuestra formación como futuro profesional. La tesis comprenderá tres capítulos y un apéndice En el primer capitulo, se analizara conceptos y elementos teóricos de la seguridad industrial, para luego poder darle una aplicación en la industria, posteriormente en el capitulo 2, se realizara` el estudio de control de perdida en el cual se vera la factibilidad de crear un programa en el que se evalúa técnica y económicamente los temas anteriores. En este último capitulo, se realizan un estudio teórico y su respectiva aplicación en base a un programa de manutención preventiva. Para terminar se complementara en un apéndice de toda la información referente a la industria en cuestión
Synthetic spectra of H Balmer and HeI absorption lines. II: Evolutionary synthesis models for starburst and post-starburst galaxies
We present evolutionary stellar population synthesis models to predict the
spectrum of a single-metallicity stellar population, with a spectral sampling
of 0.3 A in five spectral regions between 3700 and 5000 A. The models, which
are optimized for galaxies with active star formation, synthesize the profiles
of the hydrogen Balmer series (Hb, Hg, Hd, H8, H9, H10, H11, H12 and H13) and
the neutral helium absorption lines (HeI 4922, HeI 4471, HeI 4388, HeI 4144,
HeI 4121, HeI 4026, HeI 4009 and HeI 3819) for a burst with an age ranging from
1 to 1000 Myr, and different assumptions about the stellar initial mass
function. Continuous star formation models lasting for 1 Gyr are also
presented. The input stellar library includes NLTE absorption profiles for
stars hotter than 25000 K and LTE profiles for lower temperatures. The
temperature and gravity coverage is 4000 K <Teff< 50000 K and 0.0< log g$< 5.0,
respectively.
The models can be used to date starburst and post-starburst galaxies until 1
Gyr. They have been tested on data for clusters in the LMC, the super-star
cluster B in the starburst galaxy NGC 1569, the nucleus of the dwarf elliptical
NGC 205 and a luminous "E+A" galaxy. The full data set is available for
retrieval at http://www.iaa.es/ae/e2.html and at
http://www.stsci.edu/science/starburst/, or on request from the authors at
[email protected]: To be published in ApJS. 48 pages and 20 figure
copanlisib monotherapy activity in relapsed or refractory indolent b cell lymphoma combined analysis from phase i and ii studies
n/
Creació d'un sistema d'informació geogràfica i un visor web per a la Base de dades de riscos naturals d'Andorra
El projecte ha consistit en una estada de tres mesos al Centre d'Estudis de la Neu i la Muntanya d'Andorra (CENMA) amb l'objectiu de: definir i implementar un sistema d'informació geogràfica que permeti gestionar, manipular i analitzar les dades de la BDRNA; desenvolupar un visor web a través del qual servir les dades de la BDRNA; utilitzar programari específic de codi lliur
[Determinants of the use of different healthcare levels in the General System of Social Security in Health in Colombia and the Unified Health System in Brazil].
OBJECTIVE:
To compare the use of different healthcare levels, and its determinants, in two different health systems, the General System of Social Security in Health (GSSSH) and the Unified Health System (UHS) in municipalities in Colombia and Brazil.
METHODS:
A cross-sectional study was carried out, based on a population survey in two municipalities in Colombia (n=2163) and two in Brazil (n=2155). Outcome variables consisted of the use of primary care services, outpatient secondary care services, and emergency care in the previous 3 months. Explanatory variables were need and predisposing and enabling factors. Bivariate and multivariate logistic regression analyses were performed by healthcare level and country.
RESULTS:
The determinants of use differed by healthcare level and country: having a chronic disease was associated with a greater use of primary and outpatient secondary care in Colombia, and was also associated with the use of emergency care in Brazil. In Colombia, persons enrolled in the contributory scheme more frequently used the services of the GSSSH than persons enrolled with subsidized contributions in primary and outpatient secondary care and more than persons without insurance in any healthcare level. In Brazil, the low-income population and those without private insurance more frequently used the UHS at any level. In both countries, the use of primary care was increased when persons knew the healthcare center to which they were assigned and if they had a regular source of care. Knowledge of the referral hospital increased the use of outpatient secondary care and emergency care.
CONCLUSIONS:
In both countries, the influence of the determinants of use differed according to the level of care used, emphasizing the need to analyze healthcare use by disaggregating it by level of care
The AMS-RICH velocity and charge reconstruction
The AMS detector, to be installed on the International Space Station,
includes a Ring Imaging Cerenkov detector with two different radiators, silica
aerogel (n=1.05) and sodium fluoride (n=1.334). This detector is designed to
provide very precise measurements of velocity and electric charge in a wide
range of cosmic nuclei energies and atomic numbers. The detector geometry, in
particular the presence of a reflector for acceptance purposes, leads to
complex Cerenkov patterns detected in a pixelized photomultiplier matrix. The
results of different reconstruction methods applied to test beam data as well
as to simulated samples are presented. To ensure nominal performances
throughout the flight, several detector parameters have to be carefully
monitored. The algorithms developed to fulfill these requirements are
presented. The velocity and charge measurements provided by the RICH detector
endow the AMS spectrometer with precise particle identification capabilities in
a wide energy range. The expected performances on light isotope separation are
discussed.Comment: Contribution to the ICRC07, Merida, Mexico (2007); Presenter: F.
Bara
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