Statistical mechanics of rumour spreading in network communities

AbstractWe report a preliminary investigation on interactions between networked social communities using the Ising model to analyze the spread of rumours. The inner opinion of a given community is forced to change through the introduction of a unique external source and we analyze how the other communities react to this change. We model two conceptual external sources: namely, “Strong-belief”, and “Propaganda”, by an infinitely strong inhomogeneous external field and a finite uniform external field, respectively. In the former case, the community changes independently from other communities while in the latter case according also to interactions with the other communities. We apply our model to synthetic networks as well as various real world data ranging from human physical contact networks to online social networks. The experimental results using real world data clearly demonstrate two distinct scenarios of phase transitions

On the chaotic behavior of a generalized logistic pp-adic dynamical system

In the paper we describe basin of attraction $p$-adic dynamical system $G(x)=(ax)^2(x+1)$. Moreover, we also describe the Siegel discs of the system, since the structure of the orbits of the system is related to the geometry of the $p$-adic Siegel discs.Comment: 19 pages. J. Differential Equations (2007) (to appear

Visual or spatial isolation in ruminants.

Livestock production in intensive systems has expanded the world, always agreeing to raise production levels and economic returns, respectively. This vertical integration of livestock has led to some adjustments in management and also on the premises, which has changed the behavior of animals, coming from both visual and spatial constraints of the individual. In dairy farming, the creation of calves in individual stalls is an example of vertical integration, thus making a common practice in many countries. Knowing that the cattle are social animals that show high willingness to form social bonds with other individuals of the same species, some agencies have implemented laws to ensure a minimum of comfort for these animals. A systematic study of social preferences of animals and the calming effects of different animal companion familiarity are needed to document the response to separation. The objective of this review, present and discuss the effect of spatial isolation and/or visual on the productive and behavioral responses of ruminant animals.A produção animal em sistemas intensivos tem se ampliado no mundo, sempre visando à elevação de índices produtivos e retorno econômico, respectivamente. Essa verticalização da pecuária tem provocado algumas adaptações de manejo e também nas instalações, que tem alterado o comportamento dos animais, oriundo das restrições tanto visual como espacial do indivíduo. Na pecuária leiteira, a criação de bezerros em baias individuais é um exemplo dessa verticalização, tornando então uma prática comum em muitos países. Sabendo que os bovinos são animais sociais que mostram alta disponibilidade para formar vínculo social com outros indivíduos da mesma espécie, alguns órgãos têm implantado legislações para garantir um mínimo de conforto para esses animais. Um estudo sistemático das preferências sociais dos animais e os efeitos calmantes do animal companheiro de familiaridade diferente são necessários para documentar a resposta à separação. Objetivou-se com esta revisão, apresentar e discutir o efeito do isolamento espacial e/ou visual sobre as respostas produtivas e comportamentais de animais ruminantes

Centrality Behaviour of J/ψ\psi Production in Na50

The J/$\psi$ production in 158 A GeV Pb-Pb interactions is studied, in the dimuon decay channel, as a function of centrality, as measured with the electromagnetic or with the very forward calorimeters. After a first sharp variation at mid centrality, both patterns continue to fall down and exhibit a curvature change at high centrality values. This trend excludes any conventional hadronic model and is in agreement with a deconfined quark-gluon phase scenario. We report also preliminary results on the measured charged multiplicity, as given by a dedicated detector.Comment: 5 pages, 7 figures (in eps) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL http://ismd31.ccnu.edu.cn