2,216 research outputs found
El Buscón de Quevedo, la Vida de Pasamonte y el Quijote de Avellaneda
Francisco de Quevedo se burló del manuscrito de la Vida y trabajos
de Jerónimo de Pasamonte al componer un pasaje de El Buscón, y Avellaneda, al escribir el Quijote apócrifo, dio respuesta a la burla que Quevedo había hecho de Pasamonte, lo que ratifica que Avellaneda y
Pasamonte eran la misma persona. Las conclusiones obtenidas permiten
además precisar la fecha de composición de El Buscón
Killing by lung cancer or by diabetes? The trade-off between smoking and obesity
As the prevalence of smoking has decreased to below 20%, health practitioners interest has shifted towards the prevalence of obesity, and reducing it is one of the major health challenges in decades to come. In this paper we study the impact that the final product of the anti-smoking campaign, that is, smokers quitting the habit, had on average weight in the population. To these ends, we use data from the Behavioral Risk Factors Surveillance System, a large series of independent representative cross-sectional surveys. We construct a synthetic panel that allows us to control for unobserved heterogeneity and we exploit the exogenous changes in taxes and regulations to instrument the endogenous decision to give up the habit of smoking. Our estimates, are very close to estimates issued in the ’90s by the US Department of Health, and indicate that a 10% decrease in the incidence of smoking leads to an average weight increase of 2.2 to 3 pounds, depending on choice of specification. In addition, we find evidence that the effect overshoots in the short run, although a significant part remains even after two years. However, when we split the sample between men and women, we only find a significant effect for men. Finally, the implicit elasticity of quitting smoking to the probability of becoming obese is calculated at 0.58. This implies that the net benefit from reducing the incidence of smoking by 1% is positive even though the cost to society is $0.6 billions.
On the evolution of the molecular line profiles induced by the propagation of C-shock waves
We present the first results of the expected variations of the molecular line
emission arising from material recently affected by C-shocks (shock
precursors). Our parametric model of the structure of C-shocks has been coupled
with a radiative transfer code to calculate the molecular excitation and line
profiles of shock tracers such as SiO, and of ion and neutral molecules such as
H13CO+ and HN13C, as the shock propagates through the unperturbed medium. Our
results show that the SiO emission arising from the early stage of the magnetic
precursor typically has very narrow line profiles slightly shifted in velocity
with respect to the ambient cloud. This narrow emission is generated in the
region where the bulk of the ion fluid has already slipped to larger velocities
in the precursor as observed toward the young L1448-mm outflow. This strongly
suggests that the detection of narrow SiO emission and of an ion enhancement in
young shocks, is produced by the magnetic precursor of C-shocks. In addition,
our model shows that the different velocity components observed toward this
outflow can be explained by the coexistence of different shocks at different
evolutionary stages, within the same beam of the single-dish observations.Comment: 7 pages, 4 figures, accepted for publication in Ap
Huellas del joven Martínez Ruiz en el Azorín adulto: sobre el sistema ecléctico de la tetralogía crítica (1912-1915)
En este artículo se salvará la aparente distancia que separa al joven José Martínez Ruiz (1873-1967), simpatizante del anarquismo, del Azorín conservador en que se convirtió en su madurez. Para ello se presentará su tetralogía crítica, formada por Lecturas españolas (1912), Clásicos y modernos (1913), Los valores literarios (1914) y Al margen de los clásicos (1915), como el resultado de un anhelo juvenil por construir una historia de la literatura española. Se realizará un cotejo entre estas cuatro obras y el libro La evolución de la crítica, de 1899, con el objetivo de determinar qué influencia tuvieron las diversas escuelas teóricas examinadas en este opúsculo en su crítica literaria de madurez. De este análisis se concluirá que es posible apreciar una continuidad entre las metodologías críticas analizadas en La evolución de la crítica y las practicadas por el Azorín adulto. Asimismo, se propondrá que su labor crítica de madurez se sostiene sobre un sistema amplio y ecléctico heredado de estas teorías con las que se familiarizó en su juventud.This article expects to overcome the apparent distance noticed between the young José Martínez Ruiz (1873-1967), sympathizer of the anarchism, to the conservative author that later became known as Azorín. This way, his critical tetralogy (formed by Lecturas españolas, 1912, Clásicos y modernos, 1913, Los valores literarios, 1914, and Al margen de los clásicos, 1915) will be presented as a result of a young desire of writing a history of the Spanish literature. After this, the influence of his 1899 work La evolución de la crítica in the books mentioned above will be analyzed. In addition, it will be concluded that it is possible to appreciate continuity between the critical methodologies that Martínez Ruiz analyzed in La evolución de la crítica and those which he displayed to write his critical tetralogy. Finally, it will be proposed that his adult critical methodology is based on an eclectic system, which derives from the different theories of literary criticism that he learnt as a young writer
The magnetic precursor of L1448-mm: Excitation differences between ion and neutral fluids
Shock modelling predicts an electron density enhancement within the magnetic
precursor of C-shocks. Previous observations of SiO, H13CO+, HN13C and H13CN
toward the young L1448-mm outflow showed an over-excitation of the ion fluid
that was attributed to an electron density enhancement in the precursor. We
re-visit this interpretation and test if it still holds when we consider
different source morphologies and kinetic temperatures for the observed
molecules, and also give some insight on the spatial extent of the electron
density enhancement around L1448-mm.
We estimate the opacities of H13CO+ and HN13C by observing the J=3\to2 lines
of rarer isotopologues to confirm that the emission is optically thin. To model
the excitation of the molecules, we use the large velocity gradient (LVG)
approximation with updated collisional coefficients to i) re- analyse the
observations toward the positions where the over-excitation of H13CO+ has
previously been observed [i.e. toward L1448- mm at offsets (0,0) and (0,-10)],
and ii) to investigate if the electron density enhancement is still required
for the cases of extended and compact emission, and for kinetic temperatures of
up to 400 K. We also report several lines of SiO, HN13C and H13CO+ toward new
positions around this outflow, to investigate the spatial extent of the
over-excitation of the ions in L1448-mm. From the isotopologue observations, we
find that the emission of H13CO+ and HN13C from the precursor is optically thin
if this emission is extended. Using the new collisional coefficients, an
electron density enhancement is still needed to explain the excitation of
H13CO+ for extended emission and for gas temperatures of\le 400 K toward
L1448-mm (0,-10), and possibly also toward L1448-mm (0,0). For compact emission
the data cannot be fitted. We do not find any evidence for the over-excitation
of the ion fluid toward the newly observed positions around L1448-mm.
The observed line emission of SiO, H13CO+ and HN13C toward L1448-mm (0,0) and
(0,-10) is consistent with an electron density enhancement in the precursor
component, if this emission is spatially extended. This is also true for the
case of high gas temperatures (\le400 K) toward the (0,-10) offset. The
electron density enhancement seems to be restricted to the southern, redshifted
lobe of the L1448-mm outflow. Interferometric images of the line emission of
these molecules are needed to confirm the spatial extent of the over-excitation
of the ions and thus, of the electron density enhancement in the magnetic
precursor of L1448-mm.Comment: Accepted for publication in A&A; 9 pages, 3 figure
Abundant Z-cyanomethanimine in the interstellar medium: paving the way to the synthesis of adenine
We report the first detection in the interstellar medium of the Z-isomer of
cyanomethanimine (HNCHCN), an HCN dimer proposed as precursor of adenine. We
identified six transitions of Z-cyanomethanimine, along with five transitions
of E-cyanomethanimine, using IRAM 30m observations towards the Galactic Center
quiescent molecular cloud G+0.693. The Z-isomer has a column density of
(2.00.6)10 cm and an abundance of
1.510. The relative abundance ratio between the isomers is
[Z/E]6. This value cannot be explained by the two chemical formation
routes previously proposed (gas-phase and grain surface), which predicts
abundances ratios between 0.9 and 1.5. The observed [Z/E] ratio is in good
agreement with thermodynamic equilibrium at the gas kinetic temperature
(130210 K). Since isomerization is not possible in the ISM, the two species
may be formed at high temperature. New chemical models, including surface
chemistry on dust grains and gas-phase reactions, should be explored to explain
our findings. Whatever the formation mechanism, the high abundance of Z-HNCHCN
shows that precursors of adenine are efficiently formed in the ISM.Comment: Accepted in Monthly Notices of the Royal Astronomical Society Letter
Complex organic molecules in the Galactic Centre: the N-bearing family
We present an unbiased spectral line survey toward the Galactic Centre (GC)
quiescent giant molecular cloud (QGMC), G+0.693 using the GBT and IRAM 30
telescopes. Our study highlights an extremely rich organic inventory of
abundant amounts of nitrogen (N)-bearing species in a source without signatures
of star formation. We report the detection of 17 N-bearing species in this
source, of which 8 are complex organic molecules (COMs). A comparison of the
derived abundances relative to H is made across various galactic and
extragalactic environments. We conclude that the unique chemistry in this
source is likely to be dominated by low-velocity shocks with X-rays/cosmic rays
also playing an important role in the chemistry. Like previous findings
obtained for O-bearing molecules, our results for N-bearing species suggest a
more efficient hydrogenation of these species on dust grains in G+0.693 than in
hot cores in the Galactic disk, as a consequence of the low dust temperatures
coupled with energetic processing by X-ray/cosmic ray radiation in the GC.Comment: 24 pages, 23 figures, 7 tables, accepted for publication in MNRA
Catálogo de la flora vascular del Cerro del Toruño (Comarca de Los Alcores, Alcalá de Guadaíra, Sevilla)
Situado en la comarca de Los Alcores, el Cerro del Toruño es un cabezo calcarenítico incluido en el área metropolitana de Sevilla. Se encuentra protegido por la normativa provincial por el valor y naturalidad de su vegetación. El objetivo del presente estudio es la catalogación de su flora y su puesta en valor como reducto de vegetación natural en un paisaje fuertemente antropizado. Se han inventariado un total de 351 especies, 324 de ellas autóctonas, de las que tres están recogidas en la lista roja andaluza. El catálogo incluye 4 novedades corológicas de especies nativas a nivel provincial y 16 a nivel comarcal. La diversidad encontrada en la zona de estudio es comparable a la de zonas cercanas, dada la heterogeneidad de sus hábitats. Se comentan brevemente las comunidades vegetales de acebuchar, palmitar y matorral xerófilo sobre roquedos calcareníticos, en las que se ha observado un mejor grado de conservación. Finalmente se discute la importancia biogeográfica de los Alcores como isla edáfica tanto para especies calcícolas como psammófilas y litorales, dado el carácter mayoritariamente arcilloso de la Depresión del Guadalquivir.Checklist of vascular flora of the Toruño hill (Alcores region, Alcalá de Guadaira, Seville). Located in Los Alcores region, the Cerro del Toruño is a calcarenitic hill included in Sevilla’s metropolitan area. It is protected by provincial regulations due to the value and naturalness of its vegetation. The aim of this study is to catalogue its flora and highlight its importance as a patch of relict natural vegetation within a strongly anthropic landscape. We recorded 351 species, of which 324 are native and three included in the Andalusian red list. The checklist includes 4 new chorological records at the provincial level and 16 at the regional level. Species diversity is comparable to nearby areas, given its habitat heterogeneity. The wild olive copse, Mediterranean fan palm formations, and xerophilous scrublands on calcarenitic rocks display a better conservation situation and are briefly commented. Finally, we discuss the biogeographic importance of Los Alcores region as an edaphic island, surrounded by the mostly clayey Guadalquivir valley, for calcicolous and coastal sand species
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