265 research outputs found

    Compatibilidad psicológica y rendimiento deportivo

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    Considerando las tripulaciones de veleros deportivos de dos plazas como grupos formales cuya eficiencia en la cooperación depende, entre otros factores, de la compatibilidad psicológica de los tripulantes, se estudiaron los seis timoneles y sus respectivos grumetes que integraron el Equipo Nacional Cubano del año en curso. De cada uno de los 12 deportistas se obtuvieron los datos mas generales de su historial deportivo, así como sus respuestas a dos inventarios de personalidad (E.P.Q. de Eysenck y Eysenck; Inventario de Temperamento de Strelau) y a un cuestionario de opiniones (basado en el método psicosocial de la selección de compañero), calculando los coeficientes de correlación de rango de Spearman para algunas de estas variables entre timoneles y grumetes, así como entre todas ellas y el rendimiento deportivo («ranking») de las tripulaciones. Se encontraron algunas correlaciones significativas que apoyan la hipótesis acerca de la importancia de la compatibilidad psicológica timonel-grumete para el rendimiento deportivo de la tripulación y por tanto para la selección de sus integrantesRegarding two-men crews of sail boats as formal groups whose eficiency in cooperation relies, among other factors, on the psychological compatibility of its members, the six skkipers and the six sailors integrating the current Cuban National Team of this sport were studied. From each of these 12 sportsmen, data from their sportive records and answers to two personality inventories (Eysenck's E.P.Q. and Strelau's Temperament Inventory) and a questionnaire of opinions (based on the psychosocial method of «partner selection») were obtained, calculating Spearman's rank correlation coefficients between skkipers and sailors for some of these variables and between all of them and the ranking of the crews. Some statiscally significant correlations were found, which points towards the importance of skkipper-sailor psychological compatibility for the ranking of the crew and therefore for the selection of of its member

    ANATRI 1.0: representation of dichotomous and polytomous item characteristic functions

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    El programa ANATRI permite estudiar varios modelos de Teoría de la Respuesta al Item para items dicotómicos y politómicos. Los modelos para items dicotómicos incluidos son los denominados como de 1, 2, 3 y 4 parámetros, en sus versiones normal y logística. Los modelos para items politómicos son el modelo de respuesta graduada, el modelo de crédito parcial y el modelo de respuesta nominal. El usuario selecciona el modelo y especifica los parámetros de uno o varios items. Mediante el programa se obtienen las curvas características de los items y, en su caso, las funciones de regresión asociadas a las diversas segmentaciones. Permite analizar en profundidad las propiedades particulares de los items, con lo que se facilita la didáctica de los diferentes modelosThe ANATRI program helps the user in studying dichotomous and polytomous Item Response Theory models. Normal and logistic versions for the 1-, 2-, 3- and 4-parameter models are included. Three polytomous models (Partial Credit, Nominal Response and Graded Response) are also available. The user chooses the model and specifies its parameters for one or more items. Items characteristic (or operating characteristic) curves are depicted. A deep analysis of just one item is also possible. This option allows a better understanding of peculiarities of each mode

    Low temperature regeneration of activated carbons using microwaves: Revising conventional wisdom

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    [EN] The purpose of this work was to explore the application of microwaves for the low temperature regeneration of activated carbons saturated with a pharmaceutical compound (promethazine). Contrary to expectations, microwave-assisted regeneration did not lead to better results than those obtained under conventional electric heating. At low temperatures the regeneration was incomplete either under microwave and conventional heating, being this attributed to the insufficient input energy. At mild temperatures, a fall in the adsorption capacity upon cycling was obtained in both devices, although this was much more pronounced for the microwave. These results contrast with previous studies on the benefits of microwaves for the regeneration of carbon materials. The fall in the adsorption capacity after regeneration was due to the thermal cracking of the adsorbed molecules inside the carbon porous network, although this effect applies to both devices. When microwaves are used, along with the thermal heating of the carbon bed, a fraction of the microwave energy seemed to be directly used in the decomposition of promethazine through the excitation of the molecular bonds by microwaves (microwave-lysis). These results point out that the nature of the adsorbate and its ability to interact with microwave are key factors that control the application of microwaves for regeneration of exhausted activated carbons.EÇ thanks The Council of Higher Education of Turkey (YÖK) for supporting her stay at INCAR (Oviedo) and the financial support of Istanbul University Research Fund (Project 3991) for her PhD thesis. JMB acknowledges CSIC for a JAE predoctoral fellowship. COA thanks the financial support of the projects CTM2008-01956 and CSIC-200980I131.Peer reviewe

    Activation of aromatic C−C bonds of 2,2’-bipyridine ligands

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    4,4’-Disubstituted-2,2′-bipyridine ligands coordinated to Mo and Re cationic fragments become dearomatized by an intramolecular nucleophilic attack from a deprotonated N-alkylimidazole ligand in cis disposition. The subsequent protonation of these neutral complexes takes place on a pyridine carbon atom rather than at nitrogen, weakening an aromatic C−C bond and affording a dihydropyridyl moiety. Computational calculations allowed for the rationalization of the formation of the experimentally obtained products over other plausible alternatives.Financialsupport from Ministerio de Economía y Competitividad/FEDER (grant CTQ2015-70231-P) and Principado de Asturias (grant GRUPIN14-103) is gratefully acknowledged. J.D.thanks COMPUTAEX for granting access to LUSITANIA supercomputing facilities.Peer Reviewe

    Quantum entanglement patterns in the structure of atomic nuclei within the nuclear shell model

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    Quantum entanglement offers a unique perspective into the underlying structure of strongly-correlated systems such as atomic nuclei. In this paper, we use quantum information tools to analyze the structure of light and medium mass berillyum, oxygen, neon and calcium isotopes within the nuclear shell model. We use different entanglement metrics, including single-orbital entanglement, mutual information, and von Neumann entropies for different equipartitions of the shell-model valence space and identify mode/entanglement patterns related to the energy, angular momentum and isospin of the nuclear single-particle orbitals. We observe that the single-orbital entanglement is directly related to the number of valence nucleons and the energy structure of the shell, while the mutual information highlights signatures of proton-proton and neutron-neutron pairing. Proton and neutron orbitals are weakly entangled by all measures, and in fact have the lowest von Neumann entropies among all possible equipartitions of the valence space. In contrast, orbitals with opposite angular momentum projection have relatively large entropies. This analysis provides a guide for designing more efficient quantum algorithms for the noisy intermediate-scale quantum era.Comment: Submitted to EPJA Topical Issue "Quantum computing in low-energy nuclear theory

    Chagas disease in Latin American migrants: a Spanish challenge

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    AbstractChagas’ disease affects millions in Latin America and is the leading cause of cardiomyopathy and death due to cardiovascular disease in patients aged 30–50 years. As a consequence of immigration it has settled in several European countries, where besides imported cases, autochthonous infections arise through vertical transmission and blood/organ donation. All Latin American immigrants who attended our Unit were screened for T. cruzi infection (ELISA and IFAT ± PCR). An ECG and echocardiogram were requested for all positive patients, and oesophageal manometry, barium swallow and barium enema were requested according to patient symptoms. All patients under 50 years without severe cardiac involvement and who had not received correct treatment previously were treated with benznidazole 5 mg/kg/day for 60 days. Patients were followed-up with serology and PCR 1 month after treatment ended and every 6 months thereafter. A total of 1146 Latin Americans were screened for T. cruzi (357 positive serology results). The typical patient profile was a Bolivian female, of rural origin, in her fourth decade of life, without evidence of visceral involvement. Treatment tolerance was poor, with 29.7% discontinuing treatment due to adverse reactions. Among those with adverse reactions (52%), the most frequent were cutaneous hypersensitivity (68.7%), gastrointestinal upset (20%) and nervous system disturbances (16.2%). T. cruzi infection is no longer limited to Latin America. Poor treatment tolerance can limit current treatment options. More epidemiological data are necessary to estimate the magnitude of a problem of great relevance for public health and health resource planning

    The Spatial Extent of (U)LIRGs in the mid-Infrared I: The Continuum Emission

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    We present an analysis of the extended mid-infrared (MIR) emission of the Great Observatories All-Sky LIRG Survey (GOALS) sample based on 5-15um low resolution spectra obtained with the IRS on Spitzer. We calculate the fraction of extended emission as a function of wavelength for the galaxies in the sample, FEE_lambda. We can identify 3 general types of FEE_lambda: one where it is constant, one where features due to emission lines and PAHs appear more extended than the continuum, and a third which is characteristic of sources with deep silicate absorption at 9.7um. More than 30% of the galaxies have a median FEE_lambda larger than 0.5 implying that at least half of their MIR emission is extended. Luminous Infrared Galaxies (LIRGs) display a wide range of FEE in their warm dust continuum (0<=FEE_13.2um<=0.85). The large values of FEE_13.2um that we find in many LIRGs suggest that their extended MIR continuum emission originates in scales up to 10kpc. The mean size of the LIRG cores at 13.2um is 2.6kpc. However, once the LIR of the systems reaches the threshold of ~10^11.8Lsun, all sources become clearly more compact, with FEE_13.2um<=0.2, and their cores are unresolved. Our estimated upper limit for the core size of ULIRGs is less than 1.5kpc. The analysis indicates that the compactness of systems with LIR>~10^11.25Lsun strongly increases in those classified as mergers in their final stage of interaction. The FEE_13.2um is also related to the contribution of an active galactic nucleus (AGN) to the MIR. Galaxies which are more AGN-dominated are less extended, independently of their LIR. We finally find that the extent of the MIR continuum emission is correlated with the far-IR IRAS log(f_60um/f_100um) color. This enables us to place a lower limit to the area in a galaxy from where the cold dust emission may originate, a prediction which can be tested soon with the Herschel Space Telescope.Comment: 18 pages, 8 figures, accepted for publication in Ap

    A High Spatial Resolution Mid-Infrared Spectroscopic Study of the Nuclei and Star-Forming Regions in Luminous Infrared Galaxies

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    We present a high spatial (diffraction-limited) resolution (~0.3") mid-infrared (MIR) spectroscopic study of the nuclei and star-forming regions of 4 local luminous infrared galaxies (LIRGs) using T-ReCS on the Gemini South telescope. We investigate the spatial variations of the features seen in the N-band spectra of LIRGs on scales of ~100 pc, which allow us to separate the AGN emission from that of the star formation (SF). We compare our Gemini T-ReCS nuclear and integrated spectra of LIRGs with those obtained with Spitzer IRS. The 9.7um silicate absorption feature is weaker in the nuclei of the LIRGs than in the surrounding regions. This is probably due to the either clumpy or compact environment of the central AGN or young, nuclear starburst. We find that the [NeII] luminosity surface density is tightly and directly correlated with that of Pa-alpha for the LIRG star-forming regions (slope of 1.00+-0.02). Although the 11.3um PAH feature shows also a trend with Pa-alpha, this is not common for all the regions. We also find that the [NeII]\Pa-alpha ratio does not depend on the Pa-alpha equivalent width (EW), i.e., on the age of the ionizing stellar populations, suggesting that, on the scales probed here, the [NeII] emission line is a good tracer of the SF activity in LIRGs. On the other hand, the 11.3um PAH\Pa-alpha ratio increases for smaller values of the Pa-alpha EW (increasing ages), indicating that the 11.3um PAH feature can also be excited by older stars than those responsible for the Pa-alpha emission. Additional high spatial resolution observations are essential to investigate, in a statistical way, the star formation in local LIRGs at the smallest scales and to probe ultimately whether they share the same physical properties as high-z LIRGs, ULIRGs and submillimiter galaxies.Comment: 23 pages (apjstyle), 19 figures, accepted for publicacion in Ap

    Primeros resultados sobre la aplicación de la técnica de racemización de aminoácidos en la Región de Murcia (SE de la Península Ibérica) y su interés en estudios de paleosismología

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    Geochronology is a critical issue in paleoseismological research. The aminoacid racemization technique shows important advantages respect to more traditional dating methods; not just for the lower costs and promptness, also because the object to analyze is relatively frequent, in this study: terrestrial gastropods. Furthermore, the costs of the analysis are by far faster and cheaper compared to other dating techniques. Racemization results allow comparing the relative age from different sedimentary units from one trench to another.Additionally, the racemization technique can also be used as a geochronological tool, provided a calibration curve has been first obtained for the particular climate for the area and, ideally, for a particular genus. In this study we show the results obtained from the analysis of 40 samples of terrestrial gastropods from 7 different trenches located in the Murcia Region (SE Spain). Making use of the D/L ratio of aspartic acid we show the coherence found between relative stratigraphic ages and the racemization age. Finally, we show a provisional conversion equation between age of racemization, obtained from Torres et al. (1997) algorithm, and the likely age of the samples. RESUMEN: El control geocronológico es una cuestión crítica en los estudios de paleosismología. La técnica de racemización de aminoácidos ofrece importantes ventajas respecto a otros métodos de datación, tanto en los costes y rapidez, como en la facilidad de encontrar el objeto de análisis; en este estudio, gasterópodos terrestres. Los resultados permiten comparar la edad relativa entre unidades sedimentarias diferentes de unas zanjas a otras. La técnica de racemización también es una herramienta geocronológica, si bien es necesario primero establecer una curva de calibración para el ambiente climático de la zona e, idealmente, para un género concreto. En este estudio se muestran los resultados obtenidos en 40 muestras de gasterópodos terrestres recogidas en 7 zanjas de investigación paleosismológica en la Región de Murcia. Haciendo uso de la relación D/L del ácido aspártico mostramos la coherencia entre las edades relativas estratigráficas y su edad de racemización. Finalmente, proponemos una relación provisional de conversión entre las edades de racemización obtenidas por el algoritmo de Torres et al. (1997) para gasterópodos de la zona central de la Península Ibérica y la edad probable de las muestras
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