4,862 research outputs found
The gaseous extent of galaxies and the origin of Lyman alpha absorption systems. IV: Lyman alpha absorbers arising in a galaxy group
We present new GHRS observations of Lyman alpha absorption lines associated
with a group of galaxies towards the QSO 1545+2101. We have identified eight
distinct Lyman alpha absorption features in the spectrum of QSO 1545+2101 at a
mean redshift of z=0.2648 with a velocity dispersion of 163 km/s. A group of
galaxies is detected in the vicinity of this QSO at a mean redshift of z=0.2645
and velocity dispersion 239 km/s.
The identification of discrete absorption systems indicates that they arise
in clouds of neutral hydrogen rather than in a diffuse intragroup medium. Our
analysis suggests that the Lyman alpha absorption lines are associated with
individual galaxies in the group, although a one-to-one relationship between
absorbers and galaxies is difficult to establish in such a dense environment.Comment: 16 pages, 3 figures. Accepted for publication in Ap
Clasificación climática de los bosques de Abies pinsapo en el sur de España
Understanding the current distribution of vegetation and its interaction with climate regularity is important for predicting its future change. 35 weather stations with monthly resolutions have been reconstructed using GENPT software to study the pinsapo fir forest climate types. Ten climate variables have been used to describe the particular climate of A. pinsapo forests following the Climatic System of Allué (1990). A climate examination suggests that pinsapo fir forests might be established in a particular climate, which seems to be unique in the Iberian Peninsula, though the species also grows under other climates. A multivariable analysis has been done, providing five classes of pinsapo fir forests sharing some climate features: Atlantic, Mediterranean, warm, continental and cold. Results are biogeographically consistent and may help to explain plant biogeography in this region. Preservation efforts in pinsapo fir forests should be concentrated on the distribution areas with the highest risk of the climate change impact.Los estudios de distribución actual de la vegetación, en un contexto de cambio global, son un elemento importante para predecir los posibles cambios futuros. En este trabajo, a partir de 35 estaciones meteorológicas, se realizó la reconstrucción de los tipos climáticos para el pinsapo, utilizando 10 variables del Sistema Fitoclimatico de Allué (1990). Los resultados sugieren la existencia de un clima específico para la distribución del pinsapo, que parece ser único en la península ibérica, aunque la especie también esta presente en otros fitoclimas. A partir de un análisis multivariable se han identificado cinco clases fitoclimáticas con presencia de pinsapo: atlántico, mediterráneo, templado, continental y frío. Los resultados son biogeográficamente consistentes y pueden ayudar a explicar la biogeografía de su área de distribución. Los programas de conservación del pinsapo deberían utilizar información fitoclimática para definir las zonas prioritarias de protección frente a los posibles efectos del cambio climático
Ventajas y desventajas de la aplicación de la técnica de HR-ICP-MS al análisis inorgánico de aguas en terrenos volcánicos
La técnica de ICP-MS ha supuesto un gran avance en el análisis de aguas en los últimos decenios tal y como recogen las normativas al respecto en Europa, Estados Unidos, etc., habiéndose convertido en una técnica de referencia particularmente en el tema de calidad del agua. La alta resolución aplicada a la ICP-MS reduce considerablemente las interferencias y su combinación con detectores aptos para concentraciones mayoritarias hace que se disponga de una herramienta analítica muy competitiva que permite determinar simultáneamente elementos mayoritarios y trazas, incluidos halógenos (Cl, Br, I), y además relaciones isotópicas (ej., Li y B). Estos aproximadamente 60 parámetros geoquímicos permiten una caracterización exhaustiva de las aguas para temas de calidad y también ayudan a discernir más fácilmente el origen y el tránsito de las aguas a través de diferentes terrenos volcánicos. Por otra parte, la HR-ICP-MS es de gran aplicación a la determinación de los aportes geoquímicos volcanogénicos a los balances biogeoquímicos regionales, como por ejemplo de los materiales piroclásticos, a través del análisis de lixiviados procedentes de la simulación de la interacción del agua con estos productos eruptivos. En este trabajo se exponen los pros y contras de la aplicación de la HR-ICP-MS a aguas en problemáticas volcanogénicas a través de diferentes ejemplos (Islandia, Argentina, Chile, etc.). Agradecemos la asistencia del Servicio labGEOTOP (infraestructura cofinanciada por FEDER-UE, Ref. CSIC08-4E-001) del ICTJA-CSIC. La financiación fue proporcionada por QUECA (MINECO, CGL2011-23307). Este estudio se llevó a cabo en el marco del Grupo Reconocido GEOPAM (2014 SGR 869).La financiación fue proporcionada por QUECA (MINECO, CGL2011-23307). Este estudio se llevó a cabo en el marco del Grupo Reconocido GEOPAM (2014 SGR 869).Peer Reviewe
Clinical and radiological outcome of the Chimaera short nailing system in inter- and subtrochanteric fractures.
cephalomedullary devices are popular treatment for femoral intertrochanteric or subtrochanteric fractures. Various complications include post-surgical lateral thigh pain and cut-out. To prevent those complications, a new concept cephalomedullary device system was designed (Chimaera, Orthofix®). This study aimed to evaluate the clinical and radiological outcomes in patients with femoral intertrochanteric or subtrochanteric fractures treated with the proximal femoral cephalomedullary device system.
A prospective cohort study involved consecutive patients with Arbeitsgemeinschaft für Osteosynthesefragen/ Orthopaedic Trauma Association type 31-A1, 2, 3 fractures treated with the Chimaera short cephalomedullary device system from October 2016 to September 2017 at our level 1 trauma center. The Parker and Palmer mobility score and Jensen social function scores and post-surgical lateral thigh pain were assessed at 3 months post-operatively and compared to before surgery. Radiologic assessment consisted of controlling the position of the cephalic screw by using the tip-apex distance (TAD) and Cleveland zone as well as union and cut-out rates.
We included 99 patients (79 women; 100 hips; one bilateral fracture 3 months after a first trochanteric fracture) with a mean follow-up of 2 years. The Parker and Palmer mobility score decreased by 22% at 3 months post-operatively as compared with the pre-fracture score (42/99 patients showed a return to their pre-injury level). The Jensen social function score increased by 16.5% at 3 months post-operatively as compared with the pre-fracture score (68/99 patients showed a return to their pre-injury level). No major intra-operative complication was recorded. Nine TAD scores were > 25 mm. The mean TAD was 16.5 mm (range 5-36), and the lag screw position was well positioned in most (95%) hips according to Cleveland zones. Three patients required revision surgery (one for cut-out of the lag screw, one for hip osteoarthritis and one for gluteus medius insufficiency). All patients but the one with the cut-out showed fracture union.
The Chimaera short cephalomedullary device exhibited good mid-term functional and radiological outcomes
Influencia de las condiciones experimentales en la determinación de S, Cl, Br y I en agua por espectrometría de masas de alta resolución (HR-ICP-MS)
A systematic study was undertaken to optimize a method to determine S, Cl, Br and I in water by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The sample composition and preparation conditions (the total dissolved solids -TDS-, the total organic compounds -TOC- and the addition of nitric acid) were evaluated to assess the sample matrix influence. Furthermore, the effect of instrumental parameters (carrier gas flow rate, sample flow rate, radiofrequency -RF- power and analyzer resolution) was also studied to minimize the
contribution of polyatomic species, and to establish the required resolution. Low, medium or high resolutions were compared in terms of background level and sensitivity. After optimization, a multivariate robustness test was carried out by means of a Placket-Burman design. This method was applied to samples of the Llobregat and Ter rivers which are used for the drinking water system of the Metropolitan Area of Barcelona (~4.5 million inhabitants), Catalonia, northeast Spain.Este estudio fue financiado a través del Proyecto QUECA del Ministerio de Economía y Competitividad de España (CGL2011-23307) y el Proyecto PICT-2013-1259 (FONCyT, Argentina). Los análisis se realizaron en el Laboratorio de Geoquímica labGEOTOP en el ICTJA CSIC, infraestructura cofinanciada por FEDER-UE(Ref. CSIC08-4E-001).Peer Reviewe
A theoretical model for tellurite-sulfates NaCu(TeO)(SO)(OH) and KCu(TeO)(SO)(OH)
A theoretical model for two new tellurite-sulfates, namely
NaCu(TeO)(SO)(OH) and KCu(TeO)(SO)
(OH) is determined to be compatible with ab-initio calculations. The
results obtained in this work show that some previous speculations in the
literature about the couplings are correct, obtaining a model with a mixture of
ferromagnetic and antiferromagnetic couplings. We use a combination of
numerical techniques to study the magnetic properties of the model. Our
numerical calculations based on the density-matrix renormalization group method
reveal that the system presents Ising-like magnetization plateaux at rational
values of the saturation magnetization.Comment: 7 pages, 8 figure
Surgical clavicle reconstruction after aneurysmal bone cyst resection in a child: A simple method
The clavicle is an infrequent location for primary tumors in general, and aneurysmal bone cyst (ABC) of the clavicle is particularly rare. The challenge of the functional and esthetic result in the treatment of these lesions in the pediatric population is high when considering the reconstruction of critical bone defects. In this article, we present the case of a seven -year -old boy with an ABC in the middle third of the clavicle, treated by resection and reconstruction with free autograft of the fibula stabilized by using an intramedullary titanium nail. We offer a description of the used technique, considerations about treatment options in children, and a follow-up of more than two -and -a -half years
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