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Gambling in young adults aged 17-24Â years: a population-based study
A large contemporary UK cohort study, the Avon Longitudinal Study of Parents and Children, was used to investigate gambling behavior and to explore the antecedents of regular gambling in the 17–24-year age group. Participants completed computer-administered gambling surveys in research clinics, on paper, and online. The sample sizes were 3566 at age 17 years, 3940 at 20 years, and 3841 at 24 years; only 1672 completed all three surveys. Participation in gambling in the last year was reported by 54% of 17-year-olds, rising to 68% at 20 years, and 66% at 24 years, with little overall variance. Regular (weekly) gambling showed a strong gender effect, increasing among young men from 13% at 17 years to 18% at 20 years, and 17% at 24 years. Although gambling frequency increased between the ages of 17 and 20 years, gambling behaviors showed little variance between 20 and 24 years, except online gambling and betting on horseraces. The commonest forms of gambling were playing scratchcards, playing the lottery, and private betting with friends. Gambling on activities via the internet increased markedly between 17 and 24 years, especially among males. In the fully adjusted model, individual antecedents of regular gambling were being male, and having a low IQ, an external locus of control, and high sensation seeking scores. Parental gambling behavior and maternal educational background were associated with regular gambling in both sexes. Regular gambling was associated with smoking cigarettes and frequent and harmful use of alcohol, but no associations with depression were found
Efectos del entrenamiento sobre variables electrocardiográficas en equinos Fina Sangre de Carrera
Los objetivos de este estudio fueron evaluar electrocardiográficamente equinos F.S.C después de un perÃodo de 12 meses de entrenamiento, aportar una base de datos electrocardiográficos en relación al sistema de entrenamiento usado en nuestro medio y complementar la información ya existente sobre los cambios en estos parámetros inducidos por el ejercicio. Se registraron 15 ejemplares, clÃnicamente sanos, en los cuales se obtuvieron trazados de las derivaciones unipolares aVR, aVL, aVF y de las derivaciones bipolares DI, DII, DIII, correspondientes al sistema clásico de Einthoven. Para la obtención de los registros se utilizó un equipo portátil de tres canales, usando agujas colocadas subcutáneamente en el cuerpo del animal, en puntos previamente estandarizados para ubicar los electrodos exploradores. Se analizó ritmo, frecuencia cardÃaca, amplitud, duración y configuración de los parámetros electrocardiográficos. Además, se obtuvieron los ejes eléctricos promedio de activación atrial, activación ventricular y repolarización ventricular (ÂP, ÂQRS y ÂT respectivamente).Los resultados obtenidos de las variables electrocardiográficas y vectoriales fueron comparados estadÃsticamente con los valores obtenidos de los mismos ejemplares en perÃodo de amansa (Dörner 2009). Se encontraron diferencias significativas en la frecuencia cardÃaca y en la duración del proceso de depolarización atrial, lo que evidenciarÃa el desarrollo de un proceso de adaptación fisiológica a la realización de un ejercicio sistemático y constante en el tiempo. Adicionalmente, no fue posible observar caracterÃsticas electrocardiográficas que permitieran inferir la presencia de una hipertrofia ventricular, lo cual atribuimos mayoritariamente al sistema de entrenamiento usado en nuestro medio más que a la duración de este. Por otro lado, se realizó un análisis de regresión entre el peso de los individuos y sus respectivos ejes eléctricos promedio ÂP, ÂQRS y ÂT, no encontrándose relación entre éstos, de igual manera a lo que ocurrió en perÃodo de amansa (Dörner 2009). En este estudio se corrobora y complementan los cambios en los parámetros electrocardiográficos inducidos por el ejercicio en equinos F.S.C.; no obstante, el aumento de la duración del intervalo QRS no fue significativo. Los datos obtenidos, principalmente la duración de QRS, son importantes al momento de evaluar y monitorear el sistema de entrenamiento utilizado
Photon Momentum Transfer in Single-Photon Double Ionization of Helium
We theoretically and experimentally investigate the photon momentum transfer in single-photon double ionization of helium at various large photon energies. We find that the forward shifts of the momenta along the light propagation of the two photoelectrons are roughly proportional to their fraction of the excess energy. The mean value of the forward momentum is about 8/5 of the electron energy divided by the speed of light. This holds for fast and slow electrons despite the fact that the energy sharing is highly asymmetric and the slow electron is known to be ejected by secondary processes of shake off and knockout rather than directly taking its energy from the photon. The biggest deviations from this rule are found for the region of equal energy sharing where the quasifree mechanism dominates double ionization
Multiorbital tunneling ionization of the CO molecule
We coincidently measure the molecular frame photoelectron angular
distribution and the ion sum-momentum distribution of single and double
ionization of CO molecules by using circularly and elliptically polarized
femtosecond laser pulses, respectively. The orientation dependent ionization
rates for various kinetic energy releases allow us to individually identify the
ionizations of multiple orbitals, ranging from the highest occupied to the next
two lower-lying molecular orbitals for various channels observed in our
experiments. Not only the emission of a single electron, but also the
sequential tunneling dynamics of two electrons from multiple orbitals are
traced step by step. Our results confirm that the shape of the ionizing
orbitals determine the strong laser field tunneling ionization in the CO
molecule, whereas the linear Stark effect plays a minor role.Comment: This paper has been accepted for publication by Physical Review
Letter
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