181 research outputs found

    Delimitación de los conceptos de novedad y neologicidad

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    El objetivo de este estudio consiste en profundizar en las nociones de novedad y neologicidad con el fin de aislar las propiedades que contribuyen a la caracterización de la cualidad de neológico. En concreto, partimos de la idea de que el criterio lexicográfico, aunque proporciona una metodología sistemática y coherente, ofrece resultados limitados porque, de acuerdo con la percepción del hablante, algunas de las unidades identificadas como neológicas no se considerarían como tales. Por este motivo, en el marco de las tesis doctorales presentadas en el ámbito de la neología, proponemos un enfoque teórico para el estudio de estos conceptos y, a continuación, planteamos un análisis aplicado a partir de un conjunto más amplio de criterios. Las observaciones anotadas en este trabajo muestran que, efectivamente, las nociones analizadas son relevantes para avanzar en la delimitación del concepto de neologismo y contribuir, de esta forma, en la investigación actual en neología.Neology is a field of knowledge devoted to the study of new lexical units that appear in a particular language in a specific period of time. In order to identify its object of study, which is the neologism, the lexicographical criterion is the most widely-used parameter, because it provides a coherent and systematic methodology. However, the results obtained with this criterion show some limitations, such as the fact that, according to speakers’ perception, some units identified as neological are not considered new. For this reason, the aim of this article is to carry out an in-depth study of the concepts of newness and neologicity in order to detail the properties that contribute to the characterization of neological units. First of all, we propose a theoretical approach in order to develop, subsequently, an applied analysis using a greater number of criteria. The recorded observations show that the notions analysed are, in effect, relevant to the improvement of the delimitation of the concept of neologism and contribute considerably to neology research

    Identification of particles with Lorentz factor up to 10410^{4} with Transition Radiation Detectors based on micro-strip silicon detectors

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    This work is dedicated to the study of a technique for hadron identification in the TeV momentum range, based on the simultaneous measurement of the energies and of the emission angles of the Transition Radiation (TR) X-rays with respect to the radiating particles. A detector setup has been built and tested with particles in a wide range of Lorentz factors (from about 10310^3 to about 4×1044 \times 10^4 crossing different types of radiators. The measured double-differential (in energy and angle) spectra of the TR photons are in a reasonably good agreement with TR simulation predictions.Comment: 31 pages, 12 figures, paper published on Nuclear Instruments & Methods

    Inherited MC1R variants in patients with melanoma are associated with better survival in women

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    Background: Women have a better melanoma prognosis, and fairer skin/hair colour. The presence of inherited MC1R variants has been associated with a better melanoma prognosis, but its interaction with sex is unknown. Objectives: To evaluate the relationship between germline MC1R status and survival, and determine any association with sex. Methods: This was a cohort study including 1341 patients with melanoma from the Melanoma Unit of the Hospital Clinic of Barcelona, between January 1996 and April 2018. We examined known sex‐related prognosis factors as they relate to features of melanoma and evaluated the sex‐specific role of MC1R in overall and melanoma‐specific survival. Hazard ratios (HRs) were calculated using univariate and multivariate Cox logistic regression. Results: Men showed lower overall survival than women (P < 0·001) and the presence of inherited MC1R variants was not associated with better survival in our cohort. However, in women the presence of MC1R variants was associated with better overall survival in the multivariate analysis [HR 0·57, 95% confidence interval (CI) 0·38-0·85; P = 0·006] but not in men [HR 1·26, 95% CI 0·89-1·79; P = 0·185 (P‐value for interaction 0·004)]. Analysis performed for melanoma‐specific survival showed the same level of significance. Conclusions: Inherited MC1R variants are associated with improved overall survival in women with melanoma but not in men. Intrinsic sex‐dependent features can modify the role of specific genes in melanoma prognosis. We believe that survival studies of patients with melanoma should include analysis by sex and MC1R genotype

    20-ps resolution Clock Distribution Network for a fast-timing single photon detector

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    The time resolution of active pixel sensors whose timestamp mechanism is based on Time-to-Digital Converters is critically linked to the accuracy in the distribution of the master clock signal that latches the timestamp values across the detector. The Clock Distribution Network that delivers the master clock signal must compensate process-voltage-temperature variations to reduce static time errors (skew), and minimize the power supply bounce to prevent dynamic time errors (jitter). To achieve sub-100ps time resolution within pixel detectors and thus enable a step forward in multiple imaging applications, the network latencies must be adjusted in steps well below that value. Power consumption must be kept as low as possible. In this work, a self-regulated Clock Distribution Network that fulfills these requirements is presented for the FastICpix single photon detector ¿ aiming at a 65nm process. A 40 MHz master clock is distributed to 64x64 pixels over an area of 2.4x2.4 cm2 using digital Delay-Locked Loops, achieving clock leaf skew below 20 ps with a power consumption of 26 mW. Guidelines are provided to adapt the system to arbitrary chip area and pixel pitch values, yielding a versatile design with very fine time resolution

    Precision scans of the pixel cell response of double sided 3D pixel detectors to pion and x-ray beams

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    hree-dimensional (3D) silicon sensors offer potential advantages over standard planar sensors for radiation hardness in future high energy physics experiments and reduced charge-sharing for X-ray applications, but may introduce inefficiencies due to the columnar electrodes. These inefficiencies are probed by studying variations in response across a unit pixel cell in a 55μm pitch double-sided 3D pixel sensor bump bonded to TimePix and Medipix2 readout ASICs. Two complementary characterisation techniques are discussed: the first uses a custom built telescope and a 120GeV pion beam from the Super Proton Synchrotron (SPS) at CERN; the second employs a novel technique to illuminate the sensor with a micro-focused synchrotron X-ray beam at the Diamond Light Source, UK. For a pion beam incident perpendicular to the sensor plane an overall pixel efficiency of 93.0±0.5% is measured. After a 10o rotation of the device the effect of the columnar region becomes negligible and the overall efficiency rises to 99.8±0.5%. The double-sided 3D sensor shows significantly reduced charge sharing to neighbouring pixels compared to the planar device. The charge sharing results obtained from the X-ray beam study of the 3D sensor are shown to agree with a simple simulation in which charge diffusion is neglected. The devices tested are found to be compatible with having a region in which no charge is collected centred on the electrode columns and of radius 7.6±0.6μm. Charge collection above and below the columnar electrodes in the double-sided 3D sensor is observed

    Timing performance of the LHCb VELO Timepix3 Telescope

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    We performed a detailed study of the timing performance of the LHCb VELO Timepix3 Telescope with a 180 GeV/c mixed hadron beam at the CERN SPS. A twofold method was developed to improve the resolution of single-plane time measurements, resulting in a more precise overall track time measurement. The first step uses spatial information of reconstructed tracks in combination with the measured signal charge in the sensor to correct for a mixture of different effects: variations in charge carrier drift time; variations in signal induction, which are the result of a non-uniform weighting field in the pixels; and lastly, timewalk in the analog front-end. The second step corrects for systematic timing offsets in Timepix3 that vary from -2 ns to 2 ns. By applying this method, we improved the track time resolution from 438±\,\pm\,16 ps to 276±\,\pm\,4 ps

    The CORDEX Flagship Pilot Study in southeastern South America: a comparative study of statistical and dynamical downscaling models in simulating daily extreme precipitation events

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    The aim of this work is to present preliminary results of the statistical and dynamical simulations carried out within the framework of the Flagship Pilot Study in southeastern South America (FPS-SESA) endorsed by the Coordinated Regional Climate Downscaling Experiments (CORDEX) program. The FPS-SESA initiative seeks to promote inter-institutional collaboration and further networking with focus on extreme rainfall events. The main scientific aim is to study multi-scale processes and interactions most conducive to extreme precipitation events through both statistical and dynamical downscaling techniques, including convection-permitting simulations. To this end, a targeted experiment was designed considering the season October 2009 to March 2010, a period with a record number of extreme precipitation events within SESA. Also, three individual extreme events within that season were chosen as case studies for analyzing specific regional processes and sensitivity to resolutions. Four dynamical and four statistical downscaling models (RCM and ESD respectively) from different institutions contributed to the experiment. In this work, an analysis of the capability of the set of the FPS-SESA downscaling methods in simulating daily precipitation during the selected warm season is presented together with an integrated assessment of multiple sources of observations and available CORDEX Regional Climate Model simulations. Comparisons among all simulations reveal that there is no single model that performs best in all aspects evaluated. The ability in reproducing the different features of daily precipitation depends on the model. However, the evaluation of the sequence of precipitation events, their intensity and timing suggests that FPS-SESA simulations based on both RCM and ESD yield promising results. Most models capture the extreme events selected, although with a considerable spread in accumulated values and the location of heavy precipitation.Thanks to CORDEX for endorsing the FPS-SESA. This work was supported by the University of Buenos Aires 2018- 20020170100117BA grant; JMG, MLB, SAS, RPR funding from the Spanish Research Council (CSIC) I-COOP+ Program “reference COOPB20374”. JMG, JF and AL-G acknowledge support from the Spanish R&D Program through projects MULTI-SDM (CGL2015-66583-R) and INSIGNIA (CGL2016-79210-R), co-funded by the European Regional Development Fund (ERDF/FEDER). AL-G acknowledges support from the Spanish R&D Program through the predoctoral contract BES-2016-078158. Universidad de Cantabria simulations have been carried out on the Altamira Supercomputer at the Instituto de Física de Cantabria (IFCA-CSIC), member of the Spanish Supercomputing Network. MB acknowledges support from the Simons Associateship of the Abdus Salam International Centre for Theoretical Physics. RH acknowledges support from the project LTT17007 funded by the Ministry of Education, Youth, and Sports of the Czech Republic
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