355 research outputs found
Dissecting a hot molecular core: The case of G31.41+0.31
We made a detailed observational analysis of a well known hot molecular core
lying in the high-mass star-forming region G31.41+0.31. This core is believed
to contain deeply embedded massive stars and presents a velocity gradient that
has been interpreted either as rotation or as expansion, depending on the
authors. Our aim was to shed light on this question and possibly prepare the
ground for higher resolution ALMA observations which could directly detect
circumstellar disks around the embedded massive stars. Observations at
sub-arcsecond resolution were performed with the Submillimeter Array in methyl
cyanide, a typical hot molecular core tracer, and 12CO and 13CO, well known
outflow tracers. We also obtained sensitive continuum maps at 1.3 mm. Our
findings confirm the existence of a sharp velocity gradient across the core,
but cannot confirm the existence of a bipolar outflow perpendicular to it. The
improved angular resolution and sampling of the uv plane allow us to attain
higher quality channel maps of the CH3CN lines with respect to previous studies
and thus significantly improve our knowledge of the structure and kinematics of
the hot molecular core. While no conclusive argument can rule out any of the
two interpretations (rotation or expansion) proposed to explain the velocity
gradient observed in the core, in our opinion the observational evidence
collected so far indicates the rotating toroid as the most likely scenario. The
outflow hypothesis appears less plausible, because the dynamical time scale is
too short compared to that needed to form species such as CH3CN, and the mass
loss and momentum rates estimated from our measurements appear too high.Comment: Astronomy and Astrophysics, in pres
Cuadrado del binomio
En este capítulo, presentamos el proceso de diseño e implementación de la unidad didáctica del cuadrado de un binomio para grado octavo. Iniciamos con la descripción de los análisis previos (análisis de contenido, análisis cognitivo y análisis de instrucción) a la implementación que permitieron producir el primer diseño de la unidad didáctica del tema. Seguidamente, detallamos el trabajo realizado en el análisis de actuación, con el cual empezamos a analizar y a revaluar aspectos del diseño implementado de acuerdo con los resultados obtenidos por los estudiantes. Justi camos el nuevo diseño de la unidad didáctica con base en los resultados de esos análisis. Por último, concluimos con algunas re exiones sobre la experiencia vivida a lo largo del proceso
Annihilation of Dipolar Dark Matter to Photons
In this work we study the annihilation of fermionic dark matter, considering
it as a neutral particle with nonvanishing magnetic () and electric ()
dipole moments. Effective cross-section of the process is computed starting from a general form of coupling
in the framework of an extension of the Standard
Model. By taking into account annihilation of DM pairs into mono-energetic
photons, we found that for small masses, , an
electric dipole moment is required to satisfy
the current residual density inferences. Additionally, in order to pin down
models viable to describe the physics of dark matter at the early Universe we
also constrain our model according to recent measurements of the temperature
anisotropies of the cosmic background radiation, we report constraints to the
electric and magnetic dipole moments for a range of masses within our model.Comment: 20 pages, 6 figure
Concurrencia en torno a la planificación estratégica urbana. Análisis, aprendizajes y sinergias de la estrategia Zaragoza +20
Este trabajo analiza la Estrategia Zaragoza +20, marco de planificación estratégica que contiene las directrices para la intervención en la ciudad de Zaragoza (España) y su entorno metropolitano en los próximos años. En el contexto de la Planificación Estratégica Urbana, se describen los antecedentes y se revisa críticamente la metodología y enfoques empleados para la formulación del plan. La Estrategia se alinea con las principales agendas urbanas nacionales e internacionales, lo que supone uno de los primeros ejemplos en la planificación de las ciudades españolas..
Building the genomic nation: ‘Homo Brasilis’ and the ‘Genoma Mexicano’ in comparative cultural perspective
This is the final version of the article. Available from SAGE Publications via the DOI in this record.This article explores the relationship between genetic research, nationalism and the construction of collective social identities in Latin America. It makes a comparative analysis of two research projects – the ‘Genoma Mexicano’ and the ‘Homo Brasilis’ – both of which sought to establish national and genetic profiles. Both have reproduced and strengthened the idea of their respective nations of focus, incorporating biological elements into debates on social identities. Also, both have placed the unifying figure of the mestizo/mestiço at the heart of national identity constructions, and in so doing have displaced alternative identity categories, such as those based on race. However, having been developed in different national contexts, these projects have had distinct scientific and social trajectories: in Mexico, the genomic mestizo is mobilized mainly in relation to health, while in Brazil the key arena is that of race. We show the importance of the nation as a frame for mobilizing genetic data in public policy debates, and demonstrate how race comes in and out of focus in different Latin American national contexts of genomic research, while never completely disappearing.This article arises out of two projects: ‘Race, genomics and mestizaje (mixture) in Latin America:
a comparative approach’ funded by the ESRC (grant RES-062-23-1914) and ‘Public engagement
with genomic research and race in Latin America’ funded by The Leverhulme Trust (grant
RPG-044)
A cytoplasmic Slo3 isoform is expressed in somatic tissues
Slo3 is a pH-sensitive and weakly voltage-sensitive potassium channel that is essential for male fertility in mouse and whose expression is regarded as sperm-specific. These properties have proposed Slo3 as a candidate target for male contraceptive drugs. Nonetheless, the tissue distribution of Slo3 expression has not been rigorously studied yet. Applying computational and RT-PCR approaches, we identified expression of two short Slo3 isoforms in somatic mouse tissues such as brain, kidney and eye. These isoforms, which seem to result of transcription starting sites between exons 20 and 21, have an identical open reading frame, both encoding the terminal 381 amino acids of the cytosolic Slo3 domain. We corroborated the expression of these isoforms in mouse brain and testis by Western-blot. The complete isoform encoding the Slo3 ion channel was uniquely detected in testis, both at transcript and protein level. Although the functional role of the cytosolic Slo3 isoforms remains to be established, we propose that they may have a functional effect by modulating Slo channels trafficking and/or activity. This study confirms that expression of full-length Slo3 is sperm-specific but warns against developing contraceptive drugs targeting the C-terminal tail of Slo3 channels
Xanthomonas prunicola sp. nov., a novel pathogen that affects nectarine (Prunus persica var. nectarina) trees
Three isolates obtained from symptomatic nectarine trees (Prunus persica var. nectarina) cultivated in Murcia, Spain, which showed yellow and mucoid colonies similar to Xanthomonas arboricola pv. pruni, were negative after serological and real-time PCR analyses for this pathogen. For that reason, these isolates were characterized following a polyphasic approach that included both phenotypic and genomic methods. By sequence analysis of the 16S rRNA gene, these novel strains were identified as members of the genus Xanthomonas, and by multilocus sequence analysis (MLSA) they were clustered together in a distinct group that showed similarity values below 95 % with the rest of the species of this genus. Whole-genome comparisons of the average nucleotide identity (ANI) of genomes of the strains showed less than 91 % average nucleotide identity with all other species of the genus Xanthomonas. Additionally, phenotypic characterization based on API 20 NE, API 50 CH and BIOLOG tests differentiated the strains from the species of the genus Xanthomonas described previously. Moreover, the three strains were confirmed to be pathogenic on peach (Prunus persica), causing necrotic lesions on leaves. On the basis of these results, the novel strains represent a novel species of the genus Xanthomonas, for which the name Xanthomonas prunicola is proposed. The type strain is CFBP 8353 (=CECT 9404=IVIA 3287.1)
The GUAPOS project: G31.41+0.31 Unbiased ALMA sPectral Observational Survey. IV. Phosphorus-bearing molecules and their relation with shock tracers
The astrochemistry of the important biogenic element phosphorus (P) is still
poorly understood, but observational evidence indicates that P-bearing
molecules are likely associated with shocks. We study P-bearing molecules, as
well as some shock tracers, towards one of the chemically richest hot molecular
core, G31.41+0.31, in the framework of the project "G31.41+0.31 Unbiased ALMA
sPectral Observational Survey" (GUAPOS), observed with the Atacama Large
Millimeter Array (ALMA). We have observed the molecules PN, PO, SO, SO2, SiO,
and SiS, through their rotational lines in the spectral range 84.05-115.91 GHz,
covered by the GUAPOS project. PN is clearly detected while PO is tentatively
detected. The PN emission arises from two regions southwest of the hot core
peak, "1" and "2", and is undetected or tentatively detected towards the hot
core peak. the PN and SiO lines are very similar both in spatial emission
morphology and spectral shape. Region "1" is in part overlapping with the hot
core and it is warmer than region "2", which is well separated from the hot
core and located along the outflows identified in previous studies. The column
density ratio SiO/PN remains constant in regions "1" and "2", while SO/PN,
SiS/PN, and SO2/PN decrease by about an order of magnitude from region "1" to
region "2", indicating that SiO and PN have a common origin even in regions
with different physical conditions. Our study firmly confirms previous
observational evidence that PN emission is tightly associated with SiO and it
is likely a product of shock-chemistry, as the lack of a clear detection of PN
towards the hot-core allows to rule out relevant formation pathways in hot gas.
We propose the PN emitting region "2" as a new astrophysical laboratory for
shock-chemistry studiesComment: 15 pages, 11 figures, accepted for publication in A&
Congenital long QT syndrome
Artículo especialThe long QT syndrome (LQTS) is an hereditary disease that produces a malfunction on the sodium and potassium channels of the heart
and lengthens the duration of the cardiac repolarization stage. It is characterized by the appearance of syncopes, arrhythmias and even
sudden death. There are two variants of the congenital LQTS: the autosomal dominant Romano-Ward syndrome and the autosomal recessive
Jervell-Lange-Nielsen syndrome, that is associated with sensorineural deafness and is less frequent than the other type. The diagnosis
is made from the clinical criteria, the electrocardiogram and the family history. In the last few years, molecular studies have been developed,
opening new possibilities not only for its diagnosis but also for the treatment of these patients.N
The GUAPOS project: III. Characterization of the O- and N-bearing complex organic molecules content and search for chemical differentiation
Context. The G31.41+0.31 Unbiased ALMA sPectral Observational Survey (GUAPOS) project targets the hot molecular core (HMC) G31.41+0.31 (G31) to reveal the complex chemistry of one of the most chemically rich high-mass star-forming regions outside the Galactic center (GC). Aims. In the third paper of the project we present a study of nine O-bearing (CH3OH, 13CH3OH, CH318OH, CH3CHO, CH3OCH3, CH3COCH3, C2H5OH, aGg′-(CH2OH)2, and gGg′-(CH2OH)2) and six N-bearing (CH3CN,13CH3CN, CH313CN, C2H3CN, C2H5CN, and C2H513CN) complex organic molecules toward G31. The aim of this work is to characterize the abundances in G31 and to compare them with the values estimated in other sources. Moreover, we searched for a possible chemical segregation between O-bearing and N-bearing species in G31, which hosts four compact sources as seen with higher angular resolution data. In the discussion we also include the three isomers of C2H4O2 and the O- and N-bearing molecular species NH2CHO, CH3NCO, CH3C(O)CH2, and CH3NHCHO, which were analyzed in previous GUAPOS papers. Methods. Observations were carried out with the interferometer ALMA and cover the entire Band 3 from 84 to 116 GHz (∼32 GHz bandwidth) with an angular resolution of 1.2″ × 1.2″ (∼4400 au × 4400 au) and a spectral resolution of ∼0.488 MHz (∼1.3- 1.7 km s-1). The transitions of the 14 molecular species were analyzed with the tool SLIM of MADCUBA to determine the physical parameters of the emitting gas. Moreover, we analyzed the morphology of the emission of the molecular species. Results. The values of abundances with respect to H2 in G31 range from 10-6 to 10-10 for the different species. We compared the abundances with respect to methanol of O-bearing, N-bearing, and O- and N-bearing COMs in G31 with 27 other sources, including other hot molecular cores inside and outside the GC, hot corinos, shocked regions, envelopes around young stellar objects, and quiescent molecular clouds, and with chemical models. Conclusions. From the comparison with other sources there is not a unique template for the abundances in hot molecular cores, pointing toward the importance of the thermal history for the chemistry of the various sources. The abundances derived from the chemical models are in good agreement, within a factor of 10, with those of G31. From the analysis of the maps we derived the peak positions of all the molecular species toward G31. Different species peak at slightly different positions, and this, together with the different central velocities of the lines obtained from the spectral fitting, point to chemical differentiation of selected O-bearing species
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