4,637 research outputs found

    Cluster size entropy in the Axelrod model of social influence: small-world networks and mass media

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    We study the Axelrod's cultural adaptation model using the concept of cluster size entropy, ScS_{c} that gives information on the variability of the cultural cluster size present in the system. Using networks of different topologies, from regular to random, we find that the critical point of the well-known nonequilibrium monocultural-multicultural (order-disorder) transition of the Axelrod model is unambiguously given by the maximum of the Sc(q)S_{c}(q) distributions. The width of the cluster entropy distributions can be used to qualitatively determine whether the transition is first- or second-order. By scaling the cluster entropy distributions we were able to obtain a relationship between the critical cultural trait qcq_c and the number FF of cultural features in regular networks. We also analyze the effect of the mass media (external field) on social systems within the Axelrod model in a square network. We find a new partially ordered phase whose largest cultural cluster is not aligned with the external field, in contrast with a recent suggestion that this type of phase cannot be formed in regular networks. We draw a new qBq-B phase diagram for the Axelrod model in regular networks.Comment: 21 pages, 7 figure

    Strategic Behaviour, Resource Valuation and Competition in Electricity Markets

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    By means of a suitable Bayesian game we study spot electricity markets from a structural point of view. We address the problem of individual and aggregate eficciency and we show how to value water from market observables. We compare the former to engineering methods and apply our methodology to Colombian spot electricity market. Our results show that big gas and small hydro plants overbid, resources are undervalued by engineering costs and aggregate costs would have been considerably smaller if agents had played optimally. Revealed costs show a substantial gain in eficciency in the Vickrey auction compared to the actual uniform auction.Multi-unit auctions, Oligopoly, electricity markets

    Challenging educational barriers : undocumented immigrant student advocates

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    Boundary control for a class of dissipative differential operators including diffusion systems

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    In this paper we study a class of partial differential equations (PDE's), which includes Sturm-Liouville systems and diffusion equations. From this class of PDE's we define systems with control and observation through the boundary of the spatial domain. That is, we describe how to select boundary conditions, such that the resulting system has inputs and outputs acting through the boundary. Furthermore, these boundary conditions are chosen in a way that the resulting system has a nonincreasing energy.\u

    Vaccination of Cattle with the N Terminus of LppQ of Mycoplasma mycoides subsp. mycoides Results in Type III Immune Complex Disease upon Experimental Infection

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    Contagious bovine pleuropneumonia (CBPP) is a serious respiratory disease of cattle caused by Mycoplasma mycoides subsp. mycoides. Current vaccines against CBPP induce short-lived immunity and can cause severe postvaccine reactions. Previous studies have identified the N terminus of the transmembrane lipoprotein Q (LppQ-N') of M. mycoides subsp. mycoides as the major antigen and a possible virulence factor. We therefore immunized cattle with purified recombinant LppQ-N' formulated in Freund's adjuvant and challenged them with M. mycoides subsp. mycoides. Vaccinated animals showed a strong seroconversion to LppQ, but they exhibited significantly enhanced postchallenge glomerulonephritis compared to the placebo group (P = 0.021). Glomerulonephritis was characterized by features that suggested the development of antigen-antibody immune complexes. Clinical signs and gross pathological scores did not significantly differ between vaccinated and placebo groups. These findings reveal for the first time the pathogenesis of enhanced disease as a result of antibodies against LppQ during challenge and also argue against inclusion of LppQ-N' in a future subunit vaccine for CBPP
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