808 research outputs found

    Epidemiology of sports injuries in european union countries

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    La práctica deportiva es una actividad que se recomienda para mantener y promocionar la salud y los buenos hábitos. Sin embargo puede acarrear un riesgo importante de lesiones. Este estudio presenta, mediante técnicas de análisis multivariante, la relación que existe entre la tipo de lesiones, lugares del cuerpo donde se producen, los deportes más populares; fútbol, baloncesto, voleibol, y gimnasia, edad y países donde se practica, tomando datos de cinco países de la Unión Europea. Si relacionamos estas características entre sí, podemos elaborar estrategias específicas al tipo de deporte y país donde se practica, con el objeto de mejorar la prevención y poder disminuir la cantidad de lesiones que se producen.Participation in sports is a health promotion activity and maintains good habits that entail an important injury risk. The present article is a study using Multivariatye Analysis, the relationship between type of injury, location of injury, the most popular sports; soccer, basketball, volleyball, gymnastics, county where it has been practiced and age, in five European Union countries. With these relationships, we can develop specific strategies to improve prevention and to reduce the injuries that occur

    Predicting second virial coefficients of organic and inorganic compounds using Gaussian process regression

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    We show that by using intuitive and accessible molecular features it is possible to predict the temperature-dependent second virial coefficient of organic and inorganic compounds with Gaussian process regression. In particular, we built a low dimensional representation of features based on intrinsic molecular properties, topology and physical properties relevant for the characterization of molecule-molecule interactions. The featurization was used to predict second virial coefficients in the interpolative regime with a relative error ≲1% and to extrapolate the prediction to temperatures outside of the training range for each compound in the dataset with a relative error of 2.1%. Additionally, the model's predictive abilities were extended to organic molecules unseen in the training process, yielding a prediction with a relative error of 2.7%. Test molecules must be well-represented in the training set by instances of their families, which are high in variety. The method shows a generally better performance when compared to several semi-empirical procedures employed in the prediction of the quantity. Therefore, apart from being robust, the present Gaussian process regression model is extensible to a variety of organic and inorganic compounds

    On the formation of van der Waals complexes through three-body recombination

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    In this work, we show that van der Waals molecules X–RG (where RG is the rare gas atom) may be created through direct three-body recombination collisions, i.e., X + RG + RG → X–RG + RG. In particular, the three-body recombination rate at temperatures relevant for buffer gas cell experiments is calculated via a classical trajectory method in hyperspherical coordinates [Pérez-Ríos et al., J. Chem. Phys. 140, 044307 (2014)]. As a result, it is found that the formation of van der Waals molecules in buffer gas cells (1 K ≲ T ≲ 10 K) is dominated by the long-range tail (distances larger than the LeRoy radius) of the X–RG interaction. For higher temperatures, the short-range region of the potential becomes more significant. Moreover, we notice that the rate of formation of van der Walls molecules is of the same order of the magnitude independent of the chemical properties of X. As a consequence, almost any X–RG molecule may be created and observed in a buffer gas cell under proper conditions

    Classical threshold law for the formation of van der Waals molecules

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    We study the role of pairwise long-range interactions in the formation of van der Waals molecules through direct three-body recombination processes A + B + B → AB + B, based on a classical trajectory method in hyperspherical coordinates developed in our earlier works [J. Pérez-Ríos et al., J. Chem. Phys. 140, 044307 (2014); M. Mirahmadi and J. Pérez-Ríos, J. Chem. Phys. 154, 034305 (2021)]. In particular, we find the effective long-range potential in hyperspherical coordinates with an exact expression in terms of dispersion coefficients of pairwise potentials. Exploiting this relation, we derive a classical threshold law for the total cross section and the three-body recombination rate yielding an analytical expression for the three-body recombination rate as a function of the pairwise long-range coefficients of the involved partners

    Ion-atom-atom three-body recombination in cold hydrogen and deuterium plasmas

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    We present a detailed study about ion-atom-atom three-body recombination in hydrogen and deuterium plasmas based on classical trajectory calculations in hyperspherical coordinates. Our results, due to the predominant role of the long-range charged-induced dipole interaction, indicate that H2+ and D2+ are the main reaction products in the case of hydrogen and deuterium plasmas, respectively. In addition, we find a more steep energy-dependent reaction rate when the collision energy surpasses the dissociation energy of the molecular ion, thus entering a new dynamical regime dominated by short-range interactions

    The Effect of Circadian Rhythms on Shipping Accidents

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    Financiado para publicación en acceso abierto: Universidade da Coruña/CISUG[Abstract] It is a well-known fact that humans are subject to circadian alterations caused by the action of sunlight. This strongly affects their behaviour and skill, making them change their level of alertness from high at daytime to low at night-time. Taking into account this biological feature, and considering that commercial shipping is one of the oldest round-the-clock activities, raises the question whether bridge watchkeepers can carry out their tasks on night shifts with the same level of alertness as on day shifts. Furthermore, night bridge watchkeeping has to be performed in darkness or very dim light to improve the visual capacity of lookouts. A sample of vessel collisions was analysed and it was find out that this kind of accident tends to be more frequent and more serious during the darkness period of the solar day

    Excited-State Proton and Charge Transfer in Protonated Amino and Methylated Derivatives of 2-(2′-Hydroxyphenyl)benzimidazole

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    This is the peer-reviewed version of the following article: The Journal of Physical Chemistry B 2015, 119, 2475–2489, DOI: 10.1021/jp507917u, which has been published in final form at https://pubs.acs.org/doi/abs/10.1021/jp507917u. This article may be used for non-commercial purposes onlyWe studied the excited-state behavior of a family of mono- and diprotonated derivatives of 2-phenylbenzimidazole in different solvents, using steady-state and time-resolved fluorescence spectroscopy. The species investigated were 2-(4′-amino-2′-hydroxyphenyl)benzimidazole (1), the diethylamino analogue 2-(4′-N,N-diethylamino-2′-hydroxyphenyl)benzimidazole (2) and its N-methylated derivative 1-methyl-2-(4′-N,N-diethylamino-2′-hydroxyphenyl)benzimidazole (3). The O-methoxy derivatives of 2 and 3 (2-OMe and 3-OMe), and the simpler models 2-phenylbenzimidazole (4) and its 4′-amino (5) and 4′-dimethylamino (6) derivatives were also studied. We found that the dications of 1, 2, and 3 (protonated at the benzimidazole N3 and at the amino group) were strong photoacids, which were deprotonated at the hydroxyl group upon excitation in aqueous solution (totally for 2 and 3) to give a tautomer of the ground-state monocation. In contrast, no photodissociation was observed for the monocations of these species. Instead, some of the monocations studied behaved as molecular rotors, for which electronic excitation led to a twisted intramolecular charge transfer (TICT) state. The monocations of 2, 3, 2-OMe, 3-OMe, and 6, protonated at the benzimidazole N3, experienced a polarity- and viscosity-dependent radiationless deactivation associated with a large-amplitude rotational motion. We propose that this process is connected to an intramolecular charge transfer from the dimethylaminophenyl or diethylaminophenyl moiety (donor) to the protonated benzimidazole group (acceptor) of the excited monocation, which yields a twisted charge-transfer species. No fluorescence from this species was detected except for 3 and 3-OMe in low-viscosity solventsWe are indebted to the European Regional Development Fund, the Spanish Ministry of Economy and Competitiveness (Grant CTQ2010-17835), and the Xunta de Galicia (Grants GPC2013/052, CN2012/314, and EM2012/091) for financial support of our work. S.R. and J.L.P.L. are thankful for a MEC-FPU fellowship and a “Ramón y Cajal” contract, respectivelyS

    Ozone Formation in Ternary Collisions: Theory and Experiment Reconciled

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    The present Letter shows that the formation of ozone in ternary collisions O + O2 + M—the primary mechanism of ozone formation in the stratosphere—at temperatures below 200 K (for M=Ar) proceeds through a formation of a temporary complex MO2, while at temperatures above ∼700  K, the reaction proceeds mainly through a formation of long-lived vibrational resonances of O*3. At intermediate temperatures 200–700 K, the process cannot be viewed as a two-step mechanism, often used to simplify and approximate collisions of three atoms or molecules. The developed theoretical approach is applied to the reaction O + O2 + Ar because of extensive experimental data available. The rate coefficients for the formation of O3 in ternary collisions O + O2 + Ar without using two-step approximations were computed for the first time as a function of collision energy. Thermally averaged coefficients were derived for temperatures 5–900 K. It is found that the majority of O3 molecules formed initially are weakly bound. Accounting for the process of vibrational quenching of the nascent population, a good agreement with available experimental data for temperatures 100–900 K is obtained

    Consistency of cruise data of the CARINA database in the Atlantic sector of the Southern Ocean

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    13 pages, 9 figures, 1 table.-- M. Hoppema ... et al.Initially a North Atlantic project, the CARINA carbon synthesis was extended to include the Southern Ocean. Carbon and relevant hydrographic and geochemical ancillary data from cruises all across the Arctic Mediterranean Seas, Atlantic and Southern Ocean were released to the public and merged into a new database as part of the CARINA synthesis effort. Of a total of 188 cruises, 37 cruises are part of the Southern Ocean, including 11 from the Atlantic sector. The variables from all Southern Ocean cruises, including dissolved inorganic carbon (TCO2), total alkalinity, oxygen, nitrate, phosphate and silicate, were examined for cruise-to-cruise consistency in one collective effort. Seawater pH and chlorofluorocarbons (CFCs) are also part of the database, but the pH quality control (QC) is described in another Earth System Science Data publication, while the complexity of the Southern Ocean physics and biogeochemistry prevented a proper QC analysis of the CFCs. The area-specific procedures of quality control, including crossover analysis between stations and inversion analysis of all crossover data (i.e. secondary QC), are briefly described here for the Atlantic sector of the Southern Ocean. Data from an existing, quality controlled database (GLODAP) were used as a reference for our computations – however, the reference data were included into the analysis without applying the recommended GLODAP adjustments so the corrections could be independently verified. The outcome of this effort is an internally consistent, high-quality carbon data set for all cruises, including the reference cruises. The suggested corrections by the inversion analysis were allowed to vary within a fixed envelope, thus accounting for natural variability. The percentage of cruises adjusted ranged from 31% (for nitrate) to 54% (for phosphate) depending on the variable.This work has been done and funded as part of the EU project CARBOOCEAN (no. 511176; GOCE). Additional support from the International Ocean Carbon Coordination Project IOCCP (Maria Hood) and the hospitality of the Hanse Institute for Advanced Study (HWK Delmenhorst, Germany) was gratefully accepted. R. M. Key was supported by NOAA grants NA08OAR4320752 and NA08OAR4310820; X. Lin by NOAA grant NA08OAR4310820; A. Velo, F. F. Perez and A. F. R´ıos by grants: PGIDIT05OXIC40203PM Xunta de Galicia and CTM200627116E/MAR MEC; M. A´ lvarez by grant RYC-2006-001836; R. G. J. Bellerby by IPY project Bipolar Atlantic Thermohaline Circulation (BIAC, IPY Cluster #23) and Southern Ocean Biogeochemistry: Education and research (project no. 180328) from the Norwegian Research Council.Peer reviewe
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