126 research outputs found
The instantaneous radial growth rate of stellar discs
We present a new and simple method to measure the instantaneous mass and
radial growth rates of the stellar discs of spiral galaxies, based on their
star formation rate surface density (SFRD) profiles. Under the hypothesis that
discs are exponential with time-varying scalelengths, we derive a universal
theoretical profile for the SFRD, with a linear dependence on two parameters:
the specific mass growth rate and
the specific radial growth rate
of the disc. We test our theory on a sample of 35 nearby spiral galaxies, for
which we derive a measurement of and . 32/35
galaxies show the signature of ongoing inside-out growth (). The typical derived e-folding timescales for mass and radial growth in our
sample are ~ 10 Gyr and ~ 30 Gyr, respectively, with some systematic
uncertainties. More massive discs have a larger scatter in and
, biased towards a slower growth, both in mass and size. We
find a linear relation between the two growth rates, indicating that our galaxy
discs grow in size at ~ 0.35 times the rate at which they grow in mass; this
ratio is largely unaffected by systematics. Our results are in very good
agreement with theoretical expectations if known scaling relations of disc
galaxies are not evolving with time.Comment: MNRAS, accepted. 14 pages, 4 figures, 3 tables. Additional material
(Atlas.pdf) available at
http://www.filippofraternali.com/downloads/index.htm
Superior fruit total soluble solid content of red x pink F1 hybrids over nearly-isogenic parental lines
Comunicación realizada en el congresoPink-coloured tomatoes are reputed as good flavoured and are very popular in local markets. Pink tomatoes show a transparent, colourless fruit cuticle in contrast to the naringenin-chalcone flavonoid-rich, orange-yellow cuticle of normal, red tomatoes due to the y (colourless epidermis) recessive mutation in MYB12 gene located in chromosome 1. In order to investigate the basis of the alleged higher quality of pink vs. red tomatoes and, especially, our previous observations of good flavour in hybrids between red and pink tomato varieties, two red x pink F1 crosses between pairs of tomato near-isogenic lines were obtained, namely ‘Ailsa Craig’ wt/wt x ‘Ailsa Craig’ y/y and ‘Ponderosa Red’ wt/wt x ‘Ponderosa Red’ y/y, being the latter a pink tomato line in which y allele was introgressed from its closely related ‘Ponderosa Pink’ cultivar. The parental lines and the two F1 hybrids were grown to harvest in a greenhouse and total soluble solids (°Brix) and titratable acidity (TA) were measured in red ripe fruits. While no differences for °Brix were observed between the parents of each cross, significantly higher °Brix was measured in the two red x pink F1’s compared to their corresponding parental lines. No clear differences between parental lines and F1 crosses were shown for TA. The experiment was repeated but including also the pink x red, reciprocal F1 crosses. The overdominance for °Brix but not for TA was confirmed in the red x pink hybrids while the pink x red hybrids produced °Brix values similar to those of their parents.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
The GALEX/S4G UV-IR color-color diagram: Catching spiral galaxies away from the Blue Sequence
We obtained GALEX FUV, NUV, and Spitzer/IRAC 3.6m photometry for > 2000
galaxies, available for 90% of the S4G sample. We find a very tight "GALEX Blue
Sequence (GBS)" in the (FUV-NUV) versus (NUV-[3.6]) color-color diagram which
is populated by irregular and spiral galaxies, and is mainly driven by changes
in the formation timescale () and a degeneracy between and dust
reddening. The tightness of the GBS provides an unprecedented way of
identifying star-forming galaxies and objects that are just evolving to (or
from) what we call the "GALEX Green Valley (GGV)". At the red end of the GBS,
at (NUV-[3.6]) > 5, we find a wider "GALEX Red Sequence (GRS)" mostly populated
by E/S0 galaxies that has a perpendicular slope to that of the GBS and of the
optical red sequence. We find no such dichotomy in terms of stellar mass
(measured by ), since both massive () blue and red sequence galaxies are identified. The type that is
proportionally more often found in the GGV are the S0-Sa's and most of these
are located in high-density environments. We discuss evolutionary models of
galaxies that show a rapid transition from the blue to the red sequence on
timescale of years.Comment: 7 pages, 4 figures, 1 table. Accepted for publication in ApJ
Halpha Kinematics of S4G Spiral Galaxies - III. Inner rotation curves
We present a detailed study of the shape of the innermost part of the
rotation curves of a sample of 29 nearby spiral galaxies, based on high angular
and spectral resolution kinematic Halpha Fabry-Perot observations. In
particular, we quantify the steepness of the rotation curve by measuring its
slope dRvc(0). We explore the relationship between the inner slope and several
galaxy parameters, such as stellar mass, maximum rotational velocity, central
surface brightness ({\mu}0), bar strength and bulge-to-total ratio. Even with
our limited dynamical range, we find a trend for low-mass galaxies to exhibit
shallower rotation curve inner slopes than high-mass galaxies, whereas steep
inner slopes are found exclusively in high-mass galaxies. This trend may arise
from the relationship between the total stellar mass and the mass of the bulge,
which are correlated among them. We find a correlation between the inner slope
of the rotation curve and the morphological T-type, complementary to the
scaling relation between dRvc(0) and {\mu}0 previously reported in the
literature. Although we find that the inner slope increases with the Fourier
amplitude A2 and decreases with the bar torque Qb, this may arise from the
presence of the bulge implicit in both A2 and Qb. As previously noted in the
literature, the more compact the mass in the central parts of a galaxy (more
concretely, the presence of a bulge), the steeper the inner slopes. We conclude
that the baryonic matter dominates the dynamics in the central parts of our
sample galaxies.Comment: 11 pages, 11 figures, accepted for publication in MNRA
Análisis de expresión de genes potencialmente implicados en la deposición de la cutícula del fruto en líneas de introgresión de tomate
La cutícula vegetal es la capa más externa que cubre los órganos aéreos de las plantas y los protege de la pérdida de agua y del ataque de patógenos, además de determinar rasgos de calidad de fruto como el agrietado o la vida post cosecha.
Recientemente identificamos dos regiones QTL en el cromosoma 3 asociadas a la cantidad de cutícula del fruto (cm3.1 y cm3.2) en una población RIL de un cruzamiento de la especie cultivada con el silvestre Solanum pimpinellifolium acc. TO-937. Además, una IL con una introgresión de TO-937 que contiene cm3.1 y cm3.2 (sp3-3) presentaba menor cantidad de cutícula que la línea parental de tomate cultivado ‘Moneymaker’ (MM). Con el objetivo de identificar genes candidatos para estos QTLs, la expresión de genes situados en las regiones próximas a los picos de los QTLs fue analizada mediante RT-qPCR a partir de extracciones de ARN de piel de frutos en cuatro estadios de desarrollo en las líneas sp3-3 y en MM.
Se estudió la anotación de los genes en las regiones genómicas de ambos QTLs y se analizó la expresión de 42 de ellos. Los genes que presentaban mayores diferencias en sus perfiles de expresión entre las líneas sp3-3 y MM fueron analizados de nuevo empleando dos subILs obtenidas por selección asistida por marcadores que presentaban introgresiones acortadas de cm3.1 y cm3.2 e individualizadas, permitiendo así aislar los efectos de los dos QTLs y evitando posibles interferencias para la deposición de cutícula de otros QTLs conocidos que se sitúan en una región próxima a cm3.2 que también está presente en sp3-3.
Los resultados obtenidos de este segundo análisis fueron consistentes con los anteriores y permitieron plantear 2-3 genes candidatos para cada uno de los dos QTLs, que serán estudiados próximamente mediante análisis funcional y que arrojarán luz sobre los mecanismos genéticos que subyacen a las diferencias observadas en la deposición de cutícula en diferentes cultivares de tomate.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
The GALEX/S(4)G Surface Brightness and Color Profiles Catalog. I. Surface Photometry and Color Gradients of Galaxies
We present new spatially resolved surface photometry in the far-ultraviolet (FUV) and near-ultraviolet (NUV) from images obtained by the Galaxy Evolution Explorer (GALEX) and IRAC1 (3.6 mu m) photometry from the Spitzer Survey of Stellar Structure in Galaxies (S(4)G). We analyze the radial surface brightness profiles mu(FUV), mu(NUV), and mu[3.6], as well as the radial profiles of (FUV - NUV), (NUV -[3.6]), and (FUV -[3.6]) colors in 1931 nearby galaxies (z < 0.01). The analysis of the 3.6 mu m surface brightness profiles also allows us to separate the bulge and disk components in a quasi-automatic way and to compare their light and color distribution with those predicted by the chemo-spectrophotometric models for the evolution of galaxy disks of Boissier & Prantzos. The exponential disk component is best isolated by setting an inner radial cutoff and an upper surface brightness limit in stellar mass surface density. The best-fitting models to the measured scale length and central surface brightness values yield distributions of spin and circular velocity within a factor of two of those obtained via direct kinematic measurements. We find that at a surface brightness fainter than mu([3.6]) = 20.89 mag arcsec(-2), or below 3 x 10(8) M-circle dot kpc(-2) in stellar mass surface density, the average specific star formation rate (sSFR) for star-forming and quiescent galaxies remains relatively flat with radius. However, a large fraction of GALEX Green Valley galaxies show a radial decrease in sSFR. This behavior suggests that an outside-in damping mechanism, possibly related to environmental effects, could be testimony of an early evolution of galaxies from the blue sequence of star-forming galaxies toward the red sequence of quiescent galaxies
H-alpha kinematics of S4G spiral galaxies-II. Data description and non-circular motions
We present a kinematical study of 29 spiral galaxies included in the Spitzer
Survey of Stellar Structure in Galaxies, using Halpha Fabry-Perot data obtained
with the Galaxy Halpha Fabry-Perot System instrument at the William Herschel
Telescope in La Palma, complemented with images in the R-band and in Halpha.
The primary goal is to study the evolution and properties of the main
structural components of galaxies through the kinematical analysis of the FP
data, complemented with studies of morphology, star formation and mass
distribution. In this paper we describe how the FP data have been obtained,
processed and analysed. We present the resulting moment maps, rotation curves,
velocity model maps and residual maps. Images are available in FITS format
through the NASA/IPAC Extragalactic Database and the Centre de Donn\'ees
Stellaires. With these data products we study the non-circular motions, in
particular those found along the bars and spiral arms. The data indicate that
the amplitude of the non-circular motions created by the bar does not correlate
with the bar strength indicators. The amplitude of those non-circular motions
in the spiral arms does not correlate with either arm class or star formation
rate along the spiral arms. This implies that the presence and the magnitude of
the streaming motions in the arms is a local phenomenon.Comment: 23 pages, 14 figures, without appendices, accepted to be published in
MNRA
The Thick Disk in the Galaxy NGC 4244 from S^4G Imaging
If thick disks are ubiquitous and a natural product of disk galaxy formation and/or evolution processes, all
undisturbed galaxies that have evolved during a significant fraction of a Hubble time should have a thick disk. The
late-type spiral galaxy NGC 4244 has been reported as the only nearby edge-on galaxy without a confirmed thick
disk. Using data from the Spitzer Survey of Stellar Structure in Galaxies (S^4G) we have identified signs of two disk
components in this galaxy. The asymmetries between the light profiles on both sides of the mid-plane of NGC 4244
can be explained by a combination of the galaxy not being perfectly edge-on and a certain degree of opacity of
the thin disk. We argue that the subtlety of the thick disk is a consequence of either a limited secular evolution in
NGC 4244, a small fraction of stellar material in the fragments which built the galaxy, or a high amount of gaseous
accretion after the formation of the galaxy
Impact of different waves of COVID-19 on emergency medical services and out-of-hospital cardiopulmonary arrest in Madrid, Spain
Out-of-hospital cardiac arrest (OHCA) is one of the three
leading causes of death in industrialized countries.[1,2] Some
studies have described the impact of the first COVID-19
pandemic wave in terms of the number of cases and
OHCA survival rates in various regions,[3-5] but few have
addressed the relationship between the successive phases
and how they affected OHCA.[6,7] The 14-d cumulative
incidence peaked at more than 990 cases, with these rates
remaining above 200 for an eight-month period between
15 March 2020 and 15 March 2021 in Madrid, Spain.
The objectives of the current study were twofold. First,
we sought to describe how the different waves in the first
pandemic year aff ected the healthcare activity of the Spanish
emergency medical services (EMS). Second, we compared
effects of the pandemic year on OHCA care to those of
the preceding non-pandemic year in terms of initiating
cardiopulmonary resuscitation and survival in a community
with a high incidence of COVID-19.post-print164 K
UEMCOM Radio: reinforcement of powers by streaming and podcasting.
[ES] UEMCOM Radio, la emisora por internet de la Facultad de Artes y Comunicación de la UEM, se ha convertido en una herramienta docente, que vertebra el plan de estudios de las diferentes titulaciones covirtiéndose en punto de referencia para el campus cuyos planes de estudio, su enfoque hacia el mundo laboral y su claustro ha conseguido encontrar una vía de trabajo acorde con las demandas educativas, sociales y empresariales del siglo XXI y del EEES.[EN] UEMCOM Radio provides support to study plans of many faculties, and it is a reference point for the whole of our University, whose course plans, focus on the labour market and academic staff use UEMCOM Radio as a work platform suited for the educational, social and business demands of the XXI century within the European Higher Education Area.[FR] Est devenu un outil pédagogique qui vertèbre et agglutine le plan d'études des différentes titres pour devenir un point de référence pour tout le campus universitaire dont les plans d'étude et de son approche vers le monde du travail et son corps de professeurs a réussi à trouver une voie de travail conforme aux exigences éducatives, sociales et des entreprises du XXIe siècle et dans l'E.E.E.S.Ceballos Norte, JJ.; Lemrini El Ouahhabi, M.; Mateos Pizarro, RM.; Vázquez Fernández, MÁ.; Barrero Muñoz, J.; Sánchez Sanz, J.; Ruiz González, M.... (2011). UECOM Radio: Refuerzo de competencias mediante streaming y podcasting. REDU. Revista de Docencia Universitaria. 8(2):45-72. https://doi.org/10.4995/redu.2010.6195OJS45728
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