5,890 research outputs found

    Democracy in the Digital Communication Environment: A Typology Proposal of Political Monitoring Processes

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    The digital environment creates new opportunities for citizen political participation. Among these, the monitoring of political and economic power centers stands out. This includes public scrutiny of the management of public funds and the activities of the public and economic systems, thus denouncing dysfunctional features. This article aims to describe, differentiate, and classify the various forms that monitoring can take in current democracies. The results indicate that three major monitoring fields exist: governmental monitoring, shared monitoring, and civic monitoring. This study focuses on the last by specifying its four types: watchdog function, extraction and filtration of secret information, expansion of issues through alternative journalism, and extension of representation beyond parliaments

    Comportamiento biológico intraarticular de distintos aloinjertos tendinosos: estudio experimental

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    Se ha efectuado un estudio experimental comparativo, con valoración macro y microscópica, de la supervivencia, dentro de la articulación de la rodilla del conejo, de tendones flexores sobre extensores y dentro de estos, entre tendones conservados en fresco, congelados, liofilizados y fijados en solución de glutaraldehido al 0,2%. Los tendones se mantuvieron libres en la articulación receptora durante periodos distintos de tiempo. Entre los resultados destaca la pérdida de volumen, en el tiempo, de la masa tendinosa (18% de despariciones totales, con un 28% de pérdida final global). Los tendones fijados en glutaraldehido fueron los que presentaron menor pérdida de volumen. Los tendones implantados en fresco y los congelados presentaron una mayor tasa de infección. La mejor respuesta de supervivencia se detectó en los tendones conservados en glutaraldehido y los congelados. Así mismo, tenían más posibilidades de sobrevivir los flexores que los extensores. Desde el punto de vista histológico, los tendones conservados en fresco desencadenaron una mayor respuesta inflamatoria, con gran alteración estructural. Desde el punto de vista microscópico no se han hallado diferencias significativas entre flexores y extensores.Different groups of flexor and extensor tendons have been compared in their abitihty survive within the rabbit knee joint. Tendons were grouped and compared according four different storage procedures like freezing, lyophylization and fixation in 0,2% glutaraldehid. Some of them were used in fresh. All tendons have been kept inside the joint as free graft. All specimens lost weight along the study (18% of total loosing of specimen, and 28% of global loosing). Tendons fixed in disclosed less loosing of volume. Allograft infection was related to the method o glutaraildehid of storage, relationship being statistically significant (fresh tendons and frozen tendons were infected more easily). The best survival was found in both frozen and glutaraldehid fixed tendons. Flexor tendons show more chances of survival than extensors tendons. Histologically, fresh tendons disclosed the greatest inflammatory reaction. Opposite to the macroscopic findings, there were no significant differences between flexors and extensors tendons in the microscopical study

    Nuevas formas de producción de noticias en el entorno digital y cambios en el periodismo: el caso 15-M

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    The 15-M movement, driven by mass mobilisations calling for the regeneration of the political system in May 2011, has had a huge impact in the public sphere. This paper analyses the changes in news production and distribution resulting from the example set by this social movement. The creation of “new” news using social media outside the boundaries established by the journalistic and political elites represents an innovative strategy to bring the movement’s demands onto the mainstream media agenda and to instigate monitoring processes

    Decoherence in supernova neutrino transformations suppressed by deleptonization

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    In the dense-neutrino region at 50-400 km above the neutrino sphere in a supernova, neutrino-neutrino interactions cause large flavor transformations. We study when the multi-angle nature of the neutrino trajectories leads to flavor decoherence between different angular modes. We consider a two-flavor mixing scenario between nu_e and another flavor nu_x and assume the usual hierarchy F(nu_e)>F{antinu_e)>F(nu_x)=F(antinu_x) for the number fluxes. We define epsilon=(F(nu_e)-F(antinu_e))/(F(antinu_e)-F(antinu_x)) as a measure for the deleptonization flux which is the one crucial parameter. The transition between the quasi single-angle behavior and multi-angle decoherence is abrupt as a function of epsilon. For typical choices of other parameters, multi-angle decoherence is suppressed for epsilon>0.3, but a much smaller asymmetry suffices if the neutrino mass hierarchy is normal and the mixing angle small. The critical epsilon depends logarithmically on the neutrino luminosity. In a realistic supernova scenario, the deleptonization flux is probably enough to suppress multi-angle decoherence.Comment: 17 pages, 12 figures. Misprint in Eq (14) correcte

    Kinetic study of the formation of colloidal gold nanoparticles by gallic acid using stopped-flow mixing device and light scattering detection

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    II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

    Determination of antioxidant additives in foodstuffs by direct measurement of gold nanoparticle formation using resonance light scattering detection

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    III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

    Magnetic Domains and Surface Effects in Hollow Maghemite Nanoparticles

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    In the present work, we investigate the magnetic properties of ferrimagnetic and noninteracting maghemite (g-Fe2O3) hollow nanoparticles obtained by the Kirkendall effect. From the experimental characterization of their magnetic behavior, we find that polycrystalline hollow maghemite nanoparticles are characterized by low superparamagnetic-to-ferromagnetic transition temperatures, small magnetic moments, significant coercivities and irreversibility fields, and no magnetic saturation on external magnetic fields up to 5 T. These results are interpreted in terms of the microstructural parameters characterizing the maghemite shells by means of an atomistic Monte Carlo simulation of an individual spherical shell model. The model comprises strongly interacting crystallographic domains arranged in a spherical shell with random orientations and anisotropy axis. The Monte Carlo simulation allows discernment between the influence of the structure polycrystalline and its hollow geometry, while revealing the magnetic domain arrangement in the different temperature regimes.Comment: 26 pages, 8 figures. In press in Phys. Rev.

    The Cauchy problem for a class of two-dimensional nonlocal nonlinear wave equations governing anti-plane shear motions in elastic materials

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    This paper is concerned with the analysis of the Cauchy problem of a general class of two-dimensional nonlinear nonlocal wave equations governing anti-plane shear motions in nonlocal elasticity. The nonlocal nature of the problem is reflected by a convolution integral in the space variables. The Fourier transform of the convolution kernel is nonnegative and satisfies a certain growth condition at infinity. For initial data in L2L^{2} Sobolev spaces, conditions for global existence or finite time blow-up of the solutions of the Cauchy problem are established.Comment: 15 pages. "Section 6 The Anisotropic Case" added and minor changes. Accepted for publication in Nonlinearit

    Broadband distortion modeling in Lyman-α\alpha forest BAO fitting

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    In recent years, the Lyman-α\alpha absorption observed in the spectra of high-redshift quasars has been used as a tracer of large-scale structure by means of the three-dimensional Lyman-α\alpha forest auto-correlation function at redshift z2.3z\simeq 2.3, but the need to fit the quasar continuum in every absorption spectrum introduces a broadband distortion that is difficult to correct and causes a systematic error for measuring any broadband properties. We describe a kk-space model for this broadband distortion based on a multiplicative correction to the power spectrum of the transmitted flux fraction that suppresses power on scales corresponding to the typical length of a Lyman-α\alpha forest spectrum. Implementing the distortion model in fits for the baryon acoustic oscillation (BAO) peak position in the Lyman-α\alpha forest auto-correlation, we find that the fitting method recovers the input values of the linear bias parameter bFb_{F} and the redshift-space distortion parameter βF\beta_{F} for mock data sets with a systematic error of less than 0.5\%. Applied to the auto-correlation measured for BOSS Data Release 11, our method improves on the previous treatment of broadband distortions in BAO fitting by providing a better fit to the data using fewer parameters and reducing the statistical errors on βF\beta_{F} and the combination bF(1+βF)b_{F}(1+\beta_{F}) by more than a factor of seven. The measured values at redshift z=2.3z=2.3 are $\beta_{F}=1.39^{+0.11\ +0.24\ +0.38}_{-0.10\ -0.19\ -0.28}and and b_{F}(1+\beta_{F})=-0.374^{+0.007\ +0.013\ +0.020}_{-0.007\ -0.014\ -0.022}(1 (1\sigma,2, 2\sigmaand3 and 3\sigma$ statistical errors). Our fitting software and the input files needed to reproduce our main results are publicly available.Comment: 28 pages, 15 figures, matches the published versio
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