1,133 research outputs found
Integral field spectroscopy of selected areas of the Bright Bar and Orion-S cloud in the Orion Nebula
We present integral field spectroscopy of two selected zones in the Orion
Nebula obtained with the Potsdam Multi-Aperture Spectrophotometer (PMAS),
covering the optical spectral range from 3500 to 7200 A and with a spatial
resolution of 1". The observed zones are located on the prominent Bright Bar
and on the brightest area at the northeast of the Orion South cloud, both
containing remarkable ionization fronts. We obtain maps of emission line fluxes
and ratios, electron density and temperatures, and chemical abundances. We
study the ionization structure and morphology of both fields, which ionization
fronts show different inclination angles with respect to the plane of the sky.
We find that the maps of electron density, O+/H+ and O/H ratios show a rather
similar structure. We interpret this as produced by the strong dependence on
density of the [OII] lines used to derive the O+ abundance, and that our
nominal values of electron density-derived from the [SII] line ratio-may be
slightly higher than the appropriate value for the O+ zone. We measure the
faint recombination lines of OII in the field at the northeast of the Orion
South cloud allowing us to explore the so-called abundance discrepancy problem.
We find a rather constant abundance discrepancy across the field and a mean
value similar to that determined in other areas of the Orion Nebula, indicating
that the particular physical conditions of this ionization front do not
contribute to this discrepancy.Comment: 15 pages, 10 figures. Accepted for publication in MNRA
Carbon and oxygen in HII regions of the Magellanic Clouds: abundance discrepancy and chemical evolution
We present C and O abundances in the Magellanic Clouds derived from deep
spectra of HII regions. The data have been taken with the Ultraviolet-Visual
Echelle Spectrograph at the 8.2-m VLT. The sample comprises 5 HII regions in
the Large Magellanic Cloud (LMC) and 4 in the Small Magellanic Cloud (SMC). We
measure pure recombination lines (RLs) of CII and OII in all the objects,
permitting to derive the abundance discrepancy factors (ADFs) for O^2+, as well
as their O/H, C/H and C/O ratios. We compare the ADFs with those of other HII
regions in different galaxies. The results suggest a possible metallicity
dependence of the ADF for the low-metallicity objects, but more uncertain for
high-metallicity objects. We compare nebular and B-type stellar abundances and
we find that the stellar abundances agree better with the nebular ones derived
from collisionally excited lines (CELs). Comparing these results with other
galaxies we observe that stellar abundances seem to agree better with the
nebular ones derived from CELs in low-metallicity environments and from RLs in
high-metallicity environments. The C/H, O/H and C/O ratios show almost flat
radial gradients, in contrast with the spiral galaxies where such gradients are
negative. We explore the chemical evolution analysing C/O vs. O/H and comparing
with the results of HII regions in other galaxies. The LMC seems to show a
similar chemical evolution to the external zones of small spiral galaxies and
the SMC behaves as a typical star-forming dwarf galaxy.Comment: Accepted for publication in MNRAS, 17 pages, 11 figures, 8 table
Predicción de amputación mediante MESS (Mangled Extremity Severity Score) en pacientes con lesión traumática vascular grave
En este estudio retrospectivo y ciego se analizan las historias clínicas de 60 pacientes
(63 miembros inferiores), que ingresaron en nuestro hospital desde 1978 a 1992 a
causa de una lesión traumática vascular grave; en este grupo no se incluyeron los pacientes con
traumatismo vascular localizado por encima de la cadera o debajo del tobillo. El objetivo del
estudio ha sido investigar si el MESS (Mangled extremity severity score) es un sistema útil para
decidir entre la amputación precoz o el intento de reconstrucción en este tipo de pacientes. De
36 miembros que terminaron en amputación, 34 tuvieron un MESS de 7 o más, demostrando
una sensibilidad del test del 94,4%. De 27 miembros que se salvaron, 22 tuvieron un MESS de
6 o menos, demostrando una especificidad del 81,4%. Así pues, el MESS es un test útil para
predecir la necesidad o no de amputar un miembro con lesión vascular traumática grave, pero
no es absolutamente fiable. Parece más fiable cuando se aplica a pacientes con traumatismo
vascular grave que cuando se aplica a pacientes con traumatismo, tengan o no lesión vascular.60 patients (63 limbs) suffering from a severe vascular injury of the lower extremities
between 1978-1992 have been retrospectively reviewed. Those cases wherein vascular injury
was located above the hip level or under the ankle level were not included. The aim of this study
was to investígate whether the Mangled Extremity Severity Score (MESS) is a useful test to decide
between limb salvage or early amputation in this type of patients. Among 36 amputated limbs. 34
had a score equal or greater than 7, the rate of sensitivity of the test was 94,4%. Among 27 salvaged
limbs, 22 had a score equal or lower than 6, showing a rate of specificity of 81,4%. The MESS
seems to be a very useful test for prediction of limb salvage versus amputation with severe vascular
injury, although it is not totally reliable. It seems better when applied to patients with vascular injury,
rather than to those with mangled extremity, with or without vascular injury
USO DE SISTEMAS DE INFORMACIÓN GEOGRÁFICA (SIG) PARA LA DETERMINACIÓN DE PARÁMETROS UTILIZADOS EN LA CONSTRUCCIÓN DE MAPAS DE VULNERABILIDAD DE ACUÍFEROS
La validez y fiabilidad de los mapas de vulnerabilidad de acuíferos a la
contaminación depende en gran medida de la disponibilidad de una
cantidad importante de datos de gran calidad y de su posterior tratamiento.
Integrar esta información en un Sistema de Información Geográfica (SIG)
sirve para asegurar su representatividad, disponibilidad oportuna y manejo
de la misma. Ante esta situación se ha diseñado un SIG para el estudio del
acuífero del Valle de Toluca (Altiplano mexicano) que ha permitido
concentrar la información existente en diversos organismos públicos y
privados así como homogeneizar y tratar dicha información con objeto de
abordar diversos tipos de estudios de carácter hidrogeológico. Uno de estos
estudios es la elaboración del mapa de vulnerabilidad del acuífero mediante
la aplicación de la metodología DRASTIC. Un primer paso fue establecer el
mapa de profundidad del nivel piezométrico con base en diversos métodos
de interpolación, de esta forma se pudo comprobar que el método Kriging
lineal es el que ofrecía mejores y más consistentes resultados, además de
ser el más sencillo de aplicar. Igualmente, se comprobó la ventaja del uso
de SIG ya que facilitó el almacenamiento y tratamiento de la información, así
como la elaboración de los diversos tipos de mapas y su superposición.
ABSTRACT
Reliability and validity of the maps of groundwater vulnerability strongly
depend on the availability of an important amount of data of great quality and
its later treatment. Putting this information into a geographic Information
System (GIS) serves to assure its representativeness, opportune availability
and manipulation of the same one. A hydrogeologic GIS for the study of the
aquifer of the Valley of Toluca has been designed (Mexican Highlands). This
SIG has allowed to concentrate the existing information in diverse public and
private organisms as well as to provide the optimal data representation and
to manipulate this information with object to approach diverse types of
hydrogeological studies. One of these studies is the elaboration of
groundwater vulnerability map by means of DRASTIC methodology. A first
step was to establish the map of depth to water using diverse methods of
interpolation,. It was possible to be verified that the linear kriging method is
the one that offered better and consistent results, besides to be simplest to
apply. Others advantages of the SIG use are the ease for the storage and
data processing, as well as for the elaboration of the diverse types of maps
and its superposition
Refractory Thrombocytopenia Responds to Octreotide Treatment in a Case of Evans Syndrome with Gastric Neuroendocrine Tumor
A 37-year-old woman with history of Evans Syndrome with poor response to high-dose corticoid treatment presented to the emergency department with gastrointestinal and vaginal bleeding. The patient was later diagnosed with severe thrombocytopenia and a stage G1, well-differentiated gastric neuroendocrine tumor, confirmed by a biopsy. A total gastrectomy was performed to eradicate the tumor. After being treated with a total splenectomy for her Evans Syndrome with no clinical or laboratory improvement, she began regular treatment with octreotide on the basis of a possible hepatic metastasis. Days after the initiation of the octreotide, an increase in the platelet count was evidenced by laboratory findings, from 2,000 platelets/mm3 to 109,000 platelets/mm3 . Weeks later, the hepatic metastasis is discarded by a negative octreotide-body scan, and the octreotide treatment was interrupted. Immediately after the drug interruption, a progressive and evident descent in the platelet count was evidenced (4000 platelets/mm3 ). The present case report highlights the possible association between octreotide treatment and a severe thrombocytopenia resistant to conventional treatment.Revisión por pare
Radial and tangential migration of telencephalic somatostatin neurons originated from the mouse diagonal area
The telencephalic subpallium is the source of various GABAergic interneuron cohorts that invade the pallium via tangential migration. Based on genoarchitectonic studies, the subpallium has been subdivided into four major domains: striatum, pallidum, diagonal area and preoptic area (Puelles et al. 2013; Allen Developing Mouse Brain Atlas), and a larger set of molecularly distinct progenitor areas (Flames et al. 2007). Fate mapping, genetic lineage-tracing studies, and other approaches have suggested that each subpallial subdivision produces specific sorts of inhibitory interneurons, distinguished by differential peptidic content, which are distributed tangentially to pallial and subpallial target territories (e.g., olfactory bulb, isocortex, hippocampus, pallial and subpallial amygdala, striatum, pallidum, septum). In this report, we map descriptively the early differentiation and apparent migratory dispersion of mouse subpallial somatostatin-expressing (Sst) cells from E10.5 onward, comparing their topography with the expression patterns of the genes Dlx5, Gbx2, Lhx7-8, Nkx2.1, Nkx5.1 (Hmx3), and Shh, which variously label parts of the subpallium. Whereas some experimental results suggest that Sst cells are pallidal, our data reveal that many, if not most, telencephalic Sst cells derive from de diagonal area (Dg). Sst-positive cells initially only present at the embryonic Dg selectively populate radially the medial part of the bed nucleus striae terminalis (from paraseptal to amygdaloid regions) and part of the central amygdala; they also invade tangentially the striatum, while eschewing the globus pallidum and the preoptic area, and integrate within most cortical and nuclear pallial areas between E10.5 and E16.5.This work was funded by the Spanish Ministry of Science and Innovation grant BFU2008-04156, and SENECA Foundation contract 0458/GERM/06-10891 to L.P.; and the Local Government of Castilla-La Mancha grant PII1I09-0065-8194 to C.D. Infrastructure support provided by the University of Murcia and Castilla-La Mancha is also acknowledged
Spatially Resolved Star Formation Main Sequence of Galaxies in the Califa Survey
Cano-Díaz, M. et. al.The >main sequence of galaxies> - defined in terms of the total star formation rate ψ versus the total stellar mass M - is a well-studied tight relation that has been observed at several wavelengths and at different redshifts. All earlier studies have derived this relation from integrated properties of galaxies. We recover the same relation from an analysis of spatially resolved properties, with integral field spectroscopic (IFS) observations of 306 galaxies from the CALIFA survey. We consider the SFR surface density in units of log(M yr Kpc) and the stellar mass surface density in units of log(M Kpc) in individual spaxels that probe spatial scales of 0.5-1.5 Kpc. This local relation exhibits a high degree of correlation with small scatter (σ = 0.23 dex), irrespective of the dominant ionization source of the host galaxy or its integrated stellar mass. We highlight (i) the integrated star formation main sequence formed by galaxies whose dominant ionization process is related to star formation, for which we find a slope of 0.81 ± 0.02; (ii) for the spatially resolved relation obtained with the spaxel analysis, we find a slope of 0.72 ± 0.04; and (iii) for the integrated main sequence, we also identified a sequence formed by galaxies that are dominated by an old stellar population, which we have called the retired galaxies sequence.Financial support: M.C.D. and S.F.S.: DGAPA-UNAM funding; CONACyT-180125 and PAPIIT IA-100815 projects. Z.S.: EU Marie Curie Career Integration Grant >SteMaGE> PCIG12-GA-2012-326466. Y.A.: RyC-2011-09461 and AYA2013-47742-C4-3-P projects from the Spanish MINECO and the SELGIFS programme, funded by the EU (FP7-PEOPLE-2013-IRSES-612701). C.J.W.: Marie Curie Career Integration Grant 303912. R.M.G.D.: AyA2014-57490-P and J.A. P12-FQM2828 grants. J.F.B.: AYA2013-48226-C3-1-P from the Spanish MINECO grant. L.G.: Millennium Science Initiative through grant IC120009, and by CONICYT through FONDECYT grant 3140566.Peer Reviewe
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