Linear Stability of Triangular Equilibrium Points in the Generalized Photogravitational Restricted Three Body Problem with Poynting-Robertson Drag

In this paper we have examined the linear stability of triangular equilibrium points in the generalised photogravitational restricted three body problem with Poynting-Robertson drag. We have found the position of triangular equilibrium points of our problem. The problem is generalised in the sense that smaller primary is supposed to be an oblate spheroid. The bigger primary is considered as radiating. The equations of motion are affected by radiation pressure force, oblateness and P-R drag. All classical results involving photogravitational and oblateness in restricted three body problem may be verified from this result. With the help of characteristic equation, we discussed the stability. Finally we conclude that triangular equilibrium points are unstable.Comment: accepted for publication in Journal of Dynamical Systems & Geometric Theories Vol. 4, Number 1 (2006

La violence : une plénitude de sens

Chacun sait que les États-Unis ont connu au cours de leur histoire de nombreuses formes de violence individuelle ou collective dont les assassinats de président et les émeutes raciales sont les formes les plus connues. Mais , paradoxalement, la sociologie a peu abordé l'analyse de ces phénomènes. C'est à cette lacune que l'auteur tente de remédier en cherchant à établir une typologie qui soit une grille de lecture des manifestations de violence. Son hypothèse de départ est en effet que la violence peut être, comme un langage, articulée et diversifiée. La charge polémique évidente n'ôte rien, on le verra, à l'acuité sociologique de la réflexion.Freyberg J. Walter, Lautman Jacques. La violence : une plénitude de sens. In: Sociologie du travail, 13ᵉ année n°4, Octobre-décembre 1971. pp. 337-349

A justiça, o direito e os bancos de dados epidemiológicos Justice, law and epidemiological data bases

A compreensão das características do direito do século XXI, que enfrenta uma crise de legitimidade, e das grandes linhas que definem o relacionamento entre a sociedade e a ciência nesse século, marcado pelo risco e, conseqüentemente, pelo medo, sustentam a busca do justo equilíbrio entre a proteção individual e o desenvolvimento coletivo empreendida. Esse exercício foi realizado tendo como objeto os bancos de dados epidemiológicos. Examinou-se o interesse social, que pretende ter à disposição bancos de dados com as mais completas informações sobre todos os aspectos da vida das pessoas, e o interesse individual, que espera o máximo respeito à esfera da vida privada de cada membro da sociedade. Conclui-se que o direito na "sociedade do risco" demanda a construção de mecanismos que permitam a decisão e o controle públicos, de todos os cidadãos, a respeito do grau de risco que pretendem correr. No caso em exame, comissões de cidadãos, peritos e populares deveriam opinar sobre a construção, a alimentação e o uso dos bancos de dados. Nesse caso, seria importante, também, tornar acessível para todos os operadores do sistema jurídico as informações relativas a tais temas do direito sanitário.<br>An understanding of the characteristics of the law in the XXI century, facing a crisis of legitimacy characterized by risk and thus fear as the main lines defining the relationship between the society and science blur, supports the quest for a fair balance between individual protection and public development. This exercise was conducted with epidemiological data bases as its purpose. The interests of society that require data bases to be made available with full information on all aspects of people's lives were examined, in parallel to individual interests that demand the utmost respect for the private life of each member of society. The conclusion is that, in a risk society, the law requires the construction of mechanisms that allow public decision and control by all citizens of level of risk they are willing to accept. For the matter under examination, committees of citizens and experts, as well as grassroots groups, should decide on the construction, inputs and use of data bases. It would also be important to provide all practitioners within the legal system with information related to such subjects as health law

Does the French Connection (Poincaré, Lautman) Provide Some Insights Facing the Thesis That Meta-mathematics Is an Exception to the Slogan That Mathematics Concerns Structures?

International audienc