694 research outputs found

    Muros de escollera en urbanizaciones

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    The uneven and slopes terrain force us to intervene with rigid or flexible containment structures. Containment structures tend to be mostly of reinforced concrete or steel sheet piling. For some time, the use of stone jetties as containment structures and permanent stabilization in housing estates is being imposed. This type of structure has been used successfully in slopes of roads and jetties on port. When moving it to suburbia has disparaged some aspects, both design and calculation, not taking into account actions in risk areas, or eliminating essential components as filters and drain components. This document analyzes the work of intervention in two works affected in Motril (Granada, Spain) and Almeria (Spain), where the breakwaters were utilized, reaching recidivism in one of them. Guide for the design and construction of breakwaters in roadworks from the Ministry of Public Works in 1998, revised in 2006, [3] is a valuable document but requires a Decalogue of specific instructions for use in works of urbanization, in general of lower volume, and with the largest number of meetings of surfaces. Three-dimensionality is usually an important factor to take into account.Los desniveles y pendientes del terreno nos obligan a intervenir mediante estructuras de contención, rígidas o flexibles. Las estructuras de contención suelen ser en su mayor parte de hormigón armado o tablestacas metálicas. Desde hace algún tiempo se está imponiendo la utilización de escolleras de piedra como estructuras de contención y estabilización permanentes en urbanizaciones. Este tipo de estructuras ya habían sido usadas con éxito en taludes de carreteras y espigones de puerto. Al trasladarse a las urbanizaciones se ha menospreciado algunos aspectos, tanto de diseño y cálculo, no teniendo en cuenta las acciones sísmicas en zonas de riesgo como Motril, o eliminando componentes esenciales como filtros y drenajes. El presente documento analiza los trabajos de intervención realizados en dos obras siniestradas en Motril y Almería (España), donde se utilizaron las escolleras, uno de ellos incluso reincidente. La Guía para el diseño y construcción de escolleras en obras de carreteras del Ministerio de Fomento de 1998, revisada en 2006, es un valioso documento pero precisa de un decálogo de instrucciones precisas para su uso en obras de urbanización, en general de menor volumen, y con mayor número de encuentros de superficies. La tridimensionalidad suele ser un factor importante a tener en cuenta

    Quality indicators in radiation oncology: proposal of the Spanish Society of Radiation Oncology (SEOR) for a continuous improvement of the quality of care in oncology.

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    Purpose Current cancer treatment options include surgical intervention, radiotherapy, and chemotherapy. The quality of the provision of each of them and their effective coordination determines the results in terms of benefit/risk. Regarding the radiation oncology treatments, there are not stabilised quality indicators to be used to perform control and continuous improvement processes for healthcare services. Therefore, the Spanish Society of Radiation Oncology has undertaken a comprehensive project to establish quality indicators for use with the information systems available in most Spanish healthcare services. Methods A two-round Delphi study examines consensus of several possible quality indicators (n = 28) in daily practice. These indicators were defined after a bibliographic search and the assessment by radiation oncology specialists (n = 8). They included aspects regarding treatment equipment, patient preparation, treatment, and follow-up processes and were divided in structure, process, and outcome indicators. Results After the evaluation of the defined quality indicators (n = 28) by an expert panel (38 radiation oncologist), 26 indicators achieved consensus in terms of agreement with the statement. Two quality indicators did not achieve consensus. Conclusions There is a high degree of consensus in Spanish Radiation Oncology specialists on which indicators in routine clinical practice can best measure quality. These indicators can be used to classify services based on several parameters (patients, equipments, complexity of the techniques used, and scientific research). Furthermore, these indicators allow assess our current situation and set improvements’ objectives.pre-print241 K

    Dynamical age differences among coeval star clusters as revealed by blue stragglers

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    Globular star clusters that formed at the same cosmic time may have evolved rather differently from a dynamical point of view (because that evolution depends on the internal environment) through a variety of processes that tend progressively to segregate stars more massive than the average towards the cluster centre. Therefore clusters with the same chronological age may have reached quite different stages of their dynamical history (that is, they may have different dynamical ages). Blue straggler stars have masses greater than those at the turn-off point on the main sequence and therefore must be the result of either a collision or a mass-transfer event. Because they are among the most massive and luminous objects in old clusters, they can be used as test particles with which to probe dynamical evolution. Here we report that globular clusters can be grouped into a few distinct families on the basis of the radial distribution of blue stragglers. This grouping corresponds well to an effective ranking of the dynamical stage reached by stellar systems, thereby permitting a direct measure of the cluster dynamical age purely from observed properties.Comment: Published on the 20 December 2012 issue of Natur

    Blue Straggler Stars in Globular Clusters: a powerful tool to probe the internal dynamical evolution of stellar systems

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    This chapter presents an overview of the main observational results obtained to date about Blue Straggler Stars (BSSs) in Galactic Globular Clusters (GCs). The BSS specific frequency, radial distribution, chemical composition and rotational properties are presented and discussed in the framework of using this stellar population as probe of GC internal dynamics. In particular, the shape of the BSS radial distribution has been found to be a powerful tracer of the dynamical age of stellar systems, thus allowing the definition of the first empirical "dynamical clock".Comment: Chapter 5, in Ecology of Blue Straggler Stars, H.M.J. Boffin, G. Carraro & G. Beccari (Eds), Astrophysics and Space Science Library, Springe

    Exploring countermovement jump variables across competitive levels and playing positions in futsal

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    IntroductionThe aims of this study were to compare several countermovement jump (CMJ) kinetic variables between professional (PRO) and semi-professional (SEMI-PRO) futsal players and examine the differences amongst playing positions.MethodsCMJ performance from 56 male futsal players (25.2 ± 4.8 years; weight: 74.4 ± 6.4 kg) was analysed. Players were separated into PRO (n = 29; 27.0 ± 4.4 years; 75.4 ± 6.0 kg) and SEMI-PRO (n = 27; 22.7 ± 4.3 years; 73.1 ± 6.8 kg), and according to playing position: defenders (n = 16; 25.4 ± 3.7 years; 75.2 ± 6.0 kg), wingers (n = 26; 23.5 ± 4.5 years; 72.0 ± 6.9 kg), and pivots (n = 14; 28.0 ± 5.6 years; 77.8 ± 4.3 kg). Linear mixed models and effect sizes were used for the analyses based on the mean of two jumps for each variable.ResultsPRO players presented a deeper center of mass (COM) displacement (p = 0.002, ES = 0.83), greater eccentric (Ecc) absolute (p = 0.019, ES = 0.61) and relative peak power (p = 0.046, ES = 0.52), and achieved greater Ecc peak velocities (p = 0.004, ES = 0.76) when compared to SEMI-PRO. Non-significant and trivial-to-small differences were observed in all the other CMJ variables according to the competitive level and playing position.DiscussionEcc capabilities (i.e., deeper COM displacement, greater Ecc absolute and relative peak power, and peak velocity) during vertical jump seem to differentiate PRO and SEMI-PRO players. However, CMJ variables do not discriminate amongst playing positions in futsal players

    The second and third parameters of the Horizontal Branch in Globular Clusters

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    The Horizontal Branch (HB) second parameter of Globular Clusters (GCs) is a major open issue in stellar evolution. Large photometric and spectroscopic databases allow a re-examination of this issue. We derive median and extreme (90% of the distribution) colours and magnitudes of stars along the HB for about a hundred GCs. We transform these into median and extreme masses of stars on the HB taking into account evolutionary effects, and compare these masses with those expected at the tip of the Red Giant Branch to derive the total mass lost by the stars. A simple linear dependence on metallicity of this total mass lost explains well the median colours of HB stars. Adopting this mass loss law as universal, we find that age is the main second parameter. However, at least a third parameter is clearly required. The most likely candidate is the He abundance, which might be different in GCs stars belonging to the different stellar generations whose presence was previously derived from the Na-O and Mg-Al anticorrelations. Variations in the median He abundance allow explaining the extremely blue HB of some GCs; such variations are correlated with the R-parameter. Suitable He abundances allow deriving ages from the HB which are consistent with those obtained from the Main Sequence. Small corrections to these latter ages are then proposed, producing a tight age-metallicity relation for disk and bulge GCs. Star-to-star variations in the He content explain the extension of the HB. There is a strong correlation between this extension and the interquartile of the Na-O anticorrelation. The main driver for the variations in the He-content within GCs seems the total cluster mass. 47 Tuc and M3 exhibit exceptional behaviours; however, they can be accommodated in a scenario for the formation of GCs that relates their origin to cooling flows generated after very large episodes of star formation.Comment: 30 pages, 31 figures. In press on Astronomy and Astrophysics, version after language editin

    Tratamiento con glucocorticoides en pacientes con inflamación relacionada a angiopatía amiloide cerebral: ¿qué tan útil son?

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    Objective. The objective of this review is to analyze the most recent evidence on the usefulness of glucocorticoids in patients with Inflammation Related to Cerebral Amyloid Angiopathy (IrCAA). Methods. Systematic review. A bibliographic search was carried out in the search engines and databases PubMed, ScienceDirect, Embase, EBSCO and MEDLINE databases, including any article related to the evaluation of the usefulness, efficacy or safety of glucocorticoids on inflammation of the cerebral amyloid angiopathy, would be included, giving priority to original studies and systematic reviews and meta-analyses. Results. It was found that the current evidence on its use is limited, deriving mainly from case reports, case series and retrospective studies. However, it seems that these agents cause a favorable response with partial resolution of the neurological manifestations immediately and/or progressively in the medium and long term, as well as abnormal imaging changes, given by vasogenic edema and cortical and subcortical microbleeds. although the improvement of the latter is not very marked. Conclusion. Current evidence on the use of glucocorticoids and their impact on clinical and neuroimaging outcomes is limited.Objetivo. El objetivo de esta revisión consiste en analizar la evidencia más reciente sobre la utilidad de los glucocorticoides en pacientes con Inflamación relacionada a Angiopatía Amiloide Cerebral (IrAAC). Métodos. Revisión sistemática. Se llevó a cabo una búsqueda bibliográfica en los motores de búsqueda y bases de datos bases de datos PubMed, ScienceDirect, Embase, EBSCO y MEDLINE, incluyendo cualquier artículo relacionado con la evaluación de la utilidad, eficacia o seguridad de los glucocorticoides sobre la inflamación de angiopatía amiloide cerebral, sería incluido, dando prioridad a los estudios originales y a las revisiones sistemáticas y meta-análisis. Resultados. Se encontró que, la evidencia actual sobre su uso es limitada, derivando principalmente de casos reporte, series de casos y estudios retrospectivos. No obstante, parece ser que estos agentes ocasionan una respuesta favorable con solución parcial de las manifestaciones neurológicas de manera inmediata y/o progresiva a mediano y largo plazo, así como de los cambios anormales imagenológicos, dados por edema vasogénico y microsangrados corticales y subcorticales, aunque la mejoría de este último, no es muy marcado. Conclusión. La evidencia actual sobre el uso de glucocorticoides y su impacto sobre desenlaces clínicos y neuroimagenológicos es limitada

    Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

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    Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 <pT,assoc<pT,trig< < p_{\rm{T}, assoc} < p_{\rm{T}, trig} < 5.0 GeV/cc is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range η<0.9|\eta|<0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161

    Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider

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    Measurements of multi-particle azimuthal correlations (cumulants) for charged particles in p-Pb and Pb-Pb collisions are presented. They help address the question of whether there is evidence for global, flow-like, azimuthal correlations in the p-Pb system. Comparisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a Δη|\Delta \eta| gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high-multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of v2{4}v_{2}\{4\} to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find v2{4}v2{6}0v_{2}\{4\} \simeq v_{2}\{6\}\neq 0 which is indicative of a Bessel-Gaussian function for the v2v_{2} distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four- and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a Δη>1.4|\Delta\eta| > 1.4 gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87

    Charge separation relative to the reaction plane in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}= 2.76 TeV

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    Measurements of charge dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudo-rapidity range η<0.8|\eta| < 0.8 are presented as a function of the collision centrality, particle separation in pseudo-rapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge dependent azimuthal correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
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