Degree of Satisfaction-based Adaptive Interaction in Spatial Prisoner's Dilemma

To study why the altruistic cooperation behavior can emerge and maintain among egoistical individuals, researchers across several disciplines have made great contributions for the solutions of this fascinating problem. Ordinarily, the spatial structure is a most-often used framework to investigate the cooperative dynamics of evolutionary game. However, very few researchers take into account the reaction of evolutionary game dynamics to interactive intensity between individuals. On account of this, we propose a computational model of automatic adjustment the interactive intensity based on individual’s degree of satisfaction to study the iterated prisoner’s dilemma game in a two-dimensional square lattice. In this model, selfish individual considers whether the benefits obtained from the other party satisfies its own requirements to determine the intensity of interaction from it to the other party. More specifically, the interactive intensity from an individual x to its some neighbor y is driven by the relations between x obtained current benefit from y (denoted by Px→y) and x’s satisfaction payoff (denoted by Sp). If Px→y > Sp, x will increase the intensity of interaction from itself to y; On the contrary, if Px→y < Sp, x will weaken the intensity of interaction; Other scenario remain the same. Simulation results show that the proposed mechanism can effectively promote the emergence and maintain of cooperation in population, and the satisfying coefficient α (0 < α < 1) plays an essential role on cooperation. Interestingly, we found that there are some optimal values α can lead to the best promotion of cooperation. But individual’s overclaim (α > 1) is not conducive to the effective promotion of cooperation between selfish individuals even for some very small temptation to defect. Our results may contribute to the understanding of cooperative dynamics by considering the reaction of evolutionary game dynamics to network.

Ginástica para Todos e corpos experientes: um diálogo entre a ginástica e outras práticas corporais

INTRODUÇÃO: A Ginástica para Todos (GPT) vem consolidando experiências nos mais diferentes contextos socioeducativos e abarcando diferentes públicos. No Brasil, país onde essa prática gímnica é fortemente associada à Extensão Universitária, observamos nos últimos anos seu desenvolvimento junto ao público idoso. OBJETIVO: Analisar a experiência de integrantes do projeto de GPT intitulado “Ginástica para Corpos Experientes”, vinculado ao Programa UniversIDADE (Unicamp), e as possíveis relações entre essa experiência com a GPT e as vivências das participantes em outras práticas corporais. MÉTODOS: De natureza qualitativa e caracterizada como estudo de caso, partimos da realização de entrevistas estruturadas com nove integrantes do referido projeto. A análise de dados foi subsidiada pela Análise de Conteúdo. RESULTADOS: Os resultados indicam que as experiências corporais das colaboradoras se concentram nas categorias “Ginástica de Condicionamento” e “Ginástica de Conscientização Corporal”, sendo, em sua maioria, realizadas de forma individual. Oito entre as nove participantes afirmaram notar diferenças significativas entre as experiências em outras práticas e aquelas com a GPT. As diferenças apontadas versam, principalmente, sobre a proposta pedagógica utilizada neste projeto e sobre os seus desdobramentos: a criação de vínculos sociais entre integrantes, as possibilidades de adaptação de movimentos e técnicas, o fomento de habilidades sociais por meio das dinâmicas coletivas e a ação das(os) professoras(es) como facilitadores para o aprendizado de movimentos e possibilidades do corpo. CONCLUSÃO: Concluímos que o projeto “Ginástica para Corpos Experientes” oportuniza a prática da GPT de modo a contribuir com as demandas e os interesses – sociais, físicos e psicológicos – característicos do processo de envelhecimento, oportunizando a prática da ginástica de forma flexível, motivada e potente para a constituição de relações sociais. TITLE: Gymnastics for All and experienced bodies: a dialogue between gymnastics and other physical activities ABSTRACT BACKGROUND: Gymnastics for All (GfA) has been consolidating experiences in the most different socio-educational contexts, increasingly reaching heterogeneous participants. In Brazil, a country where GfA is strongly associated with University Extension, we have observed in recent years its development with the elderly public. OBJECTIVE: This study aimed to analyse the experiences of participants of the GfA project entitled “Gymnastics for Experienced Bodies”, from the “Programa UniversIDADE” (Unicamp), and the possible relations with the participants’ previous experiences regarding other physical activities. METHODS: In this case study, structured interviews were made with nine participants of the project. The data analysis was carried out based on the Content Analysis methodology. RESULTS: The results indicate that the participants’ previous experiences are concentrated in two subcategories – “Fitness” and “Mind-Body Exercises” – being mostly done individually. Eight out of nine participants said they noticed significant differences between their previous experiences and their participation on the GfA project. The differences pointed out were, mainly, on the pedagogical proposal that guides this GfA project and on the consequences of this approach: the creation of social bonds with other participants, the possibilities of adapting movements and their techniques, the promotion of social skills through cooperative dynamics, and, finally, the coach’s role as a facilitator whilst learning new movements and skills. CONCLUSION: We conclude that GfA can contribute to the demands and interests – social, physical, and psychological – characteristic of the aging process, allowing the practice of gymnastics in a flexible, motivated, and powerful way, mainly regarding the constitution of social ties.

Is there Universality in the Dielectric Response of Polar Glass Formers?

The frequency dispersion of structural α-relaxation obtained from broadband dielectric spectroscopy measurements is relatively narrow in many polar glass-formers. On the other hand, it becomes much broader when probed by other techniques, including photon correlation spectroscopy (PCS), nuclear magnetic resonance (NMR), and mechanical shear modulus. Therefore, the dynamics of glass-formers observed by dielectric permittivity spectroscopy (DS) is called into question. Herein we propose a way to resolve this problem. First, we point out an unresolved Johari-Goldstein (JG) β-relaxation is present nearby the α-relaxation in these polar glass-formers. The dielectric relaxation strength of the JG β-relaxation is sufficiently weak compared to the α-relaxation so that the narrow dielectric frequency dispersion faithfully represents the dynamic heterogeneity and cooperativity of the α-relaxation. However, when the other techniques are used to probe the same glass-former, there is a reduction of relaxation strength of α-relaxation relative to that of the JG β-relaxation. Additionally, the separation between the α and the JG β relaxations in dielectric permittivity) decreases when probed by mechanical shear modulus. These changes in relation of α- to JG β-relaxation, when examined by the other techniques, engender the non-negligible contribution of the latter to the former. Hence the apparent α-relaxation is broader than observed by the dielectric permittivity. The broadening is artificial because it is due to a confluence of the α and JG β relaxations with a disparity in their relaxation strengths much less when the other techniques than by dielectric permittivity are used. This explanation is supported by showing the α-relaxation of polar glass-formers becomes broader when the dielectric data are represented in terms of the electric modulus instead of permittivity. The broadening, in this case, is again due to a reduction of the relaxation strength of the α-relaxation relative to that of the JG β-relaxation in the electric modulus representation. A corollary of the explanation applicable to weakly polar glass-formers having JG β-relaxation widely separated from the α-relaxation is the prediction that the frequency dispersion of dielectric α-relaxation is nearly the same as that of the electric modulus, and there is no significant additional broadening when probed by the other techniques. A host of experimental data from the literature and our new measurements are given to support the explanation for polar glass-formers and the ancillary prediction for weakly polar glass-formers. Thus the narrow frequency dispersion of the intense relaxation in polar glass-formers observed by dielectric permittivity is real and genuinely represents the dynamically heterogeneous and cooperative dynamics of α-relaxation. By contrast, the broad dispersion found by the other techniques is artificial and misleading.

Back To the Back-channel

This chapter focuses on the use of the back-channel between the British government and the IRA from 1991 through 1993 and on the distinctive role of secrecy in the development of a sense of common purpose between the parties. It highlights the contribution of key British officials who advocated the reopening of the channel and an inclusive peace settlement. It also examines the importance of back-channel links between the Irish government and the SDLP on one hand, and Sinn Féin on the other, in creating pressure for progress. From 1989 onwards, the British government and the IRA made conciliatory public statements and gestures. Then, in April 1991, the British government reopened the back-channel to the IRA, sending an emissary to ask Brendan Duddy to act once again as intermediary. The particular back-channel involving Duddy established a joint project of secrecy, creating a shared task that built trust and mutual understanding. Close interpersonal relationships, continuity of personnel with previous phases of conflict, and the exclusion of internal opponents contributed to distinctively strong cooperative dynamics that helped to sustain cooperation and generate substantial progress.

Cooperative Dynamics in the Fiber Bundle Model

We discuss the cooperative failure dynamics in the fiber bundle model where the individual elements or fibers are Hookean springs that have identical spring constants but different breaking strengths. When the bundle is stressed or strained, especially in the equal-load-sharing scheme, the load supported by the failed fiber gets shared equally by the rest of the surviving fibers. This mean-field-type statistical feature (absence of fluctuations) in the load-sharing mechanism helped major analytical developments in the study of breaking dynamics in the model and precise comparisons with simulation results. We intend to present a brief review on these developments.