Phase transition in the Sznajd model with independence

We propose a model of opinion dynamics which describes two major types of social influence -- conformity and independence. Conformity in our model is described by the so called outflow dynamics (known as Sznajd model). According to sociologists' suggestions, we introduce also a second type of social influence, known in social psychology as independence. Various social experiments have shown that the level of conformity depends on the society. We introduce this level as a parameter of the model and show that there is a continuous phase transition between conformity and independence

The role of inflexible minorities in the breaking of democratic opinion dynamics

We study the effect of inflexible agents on two state opinion dynamics. The model operates via repeated local updates of random grouping of agents. While floater agents do eventually flip their opinion to follow the local majority, inflexible agents keep their opinion always unchanged. It is a quenched individual opinion. In the bare model (no inflexibles), a separator at 50% drives the dynamics towards either one of two pure attractors, each associated with a full polarization along one of the opinions. The initial majority wins. The existence of inflexibles for only one of the two opinions is found to shift the separator at a lower value than 50% in favor of that side. Moreover it creates an incompressible minority around the inflexibles, one of the pure attractors becoming a mixed phase attractor. In addition above a threshold of 17% inflexibles make their side sure of winning whatever the initial conditions are. The inflexible minority wins. An equal presence of inflexibles on both sides restores the balanced dynamics with again a separator at 50% and now two mixed phase attractors on each side. Nevertheless, beyond 25% the dynamics is reversed with a unique attractor at a fifty-fifty stable equilibrium. But a very small advantage in inflexibles results in a decisive lowering of the separator at the advantage of the corresponding opinion. A few percent advantage does guarantee to become majority with one single attractor. The model is solved exhaustedly for groups of size 3.Comment: 18 pages, 12 figure

From 2000 Bush-Gore to 2006 Italian elections: Voting at fifty-fifty and the Contrarian Effect

A sociophysical model for opinion dynamics is shown to embody a series of recent western hung national votes all set at the unexpected and very improbable edge of a fifty-fifty score. It started with the Bush-Gore 2000 American presidential election, followed by the 2002 Stoiber-Schr\H{o}der, then the 2005 Schr\H{o}der-Merkel German elections, and finally the 2006 Prodi-Berlusconi Italian elections. In each case, the country was facing drastic choices, the running competing parties were advocating very different programs and millions of voters were involved. Moreover, polls were given a substantial margin for the predicted winner. While all these events were perceived as accidental and isolated, our model suggests that indeed they are deterministic and obey to one single universal phenomena associated to the effect of contrarian behavior on the dynamics of opinion forming. The not hung Bush-Kerry 2005 presidential election is shown to belong to the same universal frame. To conclude, the existence of contrarians hints at the repetition of hung elections in the near future.Comment: 17 pages, 8 figure

Legal determinants of external finance revisited : the inverse relationship between investor protection and societal well-being

This paper investigates relationships between corporate governance traditions and quality of life as measured by a number of widely reported indicators. It provides an empirical analysis of indicators of societal health in developed economies using a classification based on legal traditions. Arguably the most widely cited work in the corporate governance literature has been the collection of papers by La Porta et al. which has shown, inter alia, statistically significant relationships between legal traditions and various proxies for investor protection. We show statistically significant relationships between legal traditions and various proxies for societal health. Our comparative evidence suggests that the interests of investors may not be congruent with the interests of wider society, and that the criteria for judging the effectiveness of approaches to corporate governance should not be restricted to financial metrics

NFC as an Alternative for Improving Videogame Development in Mobile Devices

La aparición de nuevas alternativas de interacción puede llevar a generar videojuegos cada vez más interesantes, este es el caso de la interacción con el teléfono móvil, especialmente la tecnología NFC. Sin embargo no existe un referente para conocer qué tipos de videojuegos serían los más apropiados para desarrollar con NFC. Por tanto, este artículo aporta una revisión de varias fuentes para determinar el estado actual de videojuegos con NFC para futuras referencias de generadores de contenido y emprendedores en el campo de los videojuegos; como contribuciones se tiene una revisión en varias fuentes a nivel comercial, bibliográfico y de tiendas de aplicaciones para generar el estado actual y el esquema de posibles videojuegos con los cuales NFC podría interactuar, determinando las categorías de videojuegos más apropiadas para desarrollar con dicha tecnología y proponiendo algunas características que NFC permite implementar.The emergence of new interaction alternatives can result in increasingly interesting videogames; this is the case of the interaction with the mobile phone, especially NFC technology. However, there is not a model to get to know the types of videogames that would be more appropriate to be developed with NFC. Therefore, this article provides a review of several sources to determine current state of videogames with NFC for future reference of content generators and entrepreneurs in the field of videogames; as a contribution, there is a review of several commercial, bibliographic sources and applications shops to generate current state and a scheme of potential videogames with which NFC could interact by determining categories of the most appropriate videogames to be developed with such a technology and proposing some features that can be implemented with the NFC

The Contribution of Active Galactic Nuclei to the Microjansky Radio Population

A X-ray background synthesis model is used to calculate the contribution of Active Galactic Nuclei (AGNs) to the 1.4 GHz number counts between 100 nJy and 10 mJy. The number counts are broken down into contributions from radio-quiet and radio-loud AGNs, obscured and unobscured AGNs, and for different ranges in redshift and 2-10 keV X-ray luminosity, L_X. Compton-thick AGNs are included, but only to the level required to fit the peak of the X-ray background. The predicted radio counts show that the microJy AGN population will be dominated by obscured, radio-quiet Seyfert galaxies with log L_X < 43, and spanning 0 < z <~ 3. However, depending on the exact relationship between the radio and X-ray luminosities in radio-quiet AGNs, additional radio flux due to star-formation within AGN host galaxies may be necessary in order to match the observed AGN counts at a flux density of ~50 microJy. The star-formation rates (SFR) required are modest, only ~3 Msun per year, assuming a constant rate with z and L_X. A more observationally and theoretically motivated relationship, where the SFR \propto (1+z)^{1.76}(log L_X-40)^{3.5}, will also account for the observed counts. The microJy AGN population will provide a very clean sample to trace the accretion and galactic star-formation histories of Seyfert galaxies over a significant fraction of cosmic time.Comment: 30 pages, 11 figures, accepted by the Ap

Long-term use of non-steroidal anti-inflammatory drugs and the risk of myocardial infarction in the general population

BACKGROUND: Recent data indicate that chronic use of coxibs leads to an increased occurrence of thrombotic cardiovascular events. This raises the question as to whether traditional non-steroidal anti-inflammatory drugs (tNSAIDs) might also produce similar hazards. Our aim has been to evaluate the association between the chronic use of tNSAIDs and the risk of myocardial infarction (MI) in patients. METHODS: We performed a nested case-control analysis with 4,975 cases of acute MI and 20,000 controls, frequency matched to cases by age, sex, and calendar year. RESULTS: Overall, current use of tNSAID was not associated with an increased risk of MI (RR:1.07;95%CI: 0.95–1.21). However, we found that the relative risk (RR) of MI for durations of tNSAID treatment of >1 year was 1.21 (95% CI, 1.00–1.48). The corresponding RR was 1.34 (95% CI, 1.06–1.70) for non-fatal MI. The effect was independent from dose. The small risk associated with long-term use of tNSAIDs was observed among patients not taking low-dose aspirin (RR: 1.29; 95% CI, 1.01–1.65). The effect of long-term use for individual tNSAIDs ranged from a RR of 0.87 (95% CI, 0.47–1.62) with naproxen to 1.38 (95% CI, 1.00–1.90) with diclofenac. CONCLUSION: This study adds support to the hypothesis that chronic treatment with some tNSAIDs is associated with a small increased risk of non-fatal MI. Our data are consistent with a substantial variability in cardiovascular risks between individual tNSAIDs

Influence of vibrations on electron transport through nanoscale contacts

In this article we present a novel semi-analytical approach to calculate first-order electron-vibration coupling constants within the framework of density functional theory. It combines analytical expressions for the first-order derivative of the Kohn-Sham operator with respect to nuclear displacements with coupled-perturbed Kohn-Sham theory to determine the derivative of the electronic density matrix. This allows us to efficiently compute accurate electron-vibration coupling constants. We apply our approach to describe inelastic electron tunneling spectra of metallic and molecular junctions. A gold junction bridged by an atomic chain is used to validate the developed method, reproducing established experimental and theoretical results. For octane-dithiol and octane-diamine single-molecule junctions we discuss the influence of the anchoring group and mechanical stretching on the inelastic electron tunneling spectra.Comment: 13 pages, 5 figure