Generic occurrence of rings in rotating systems

In rotating scattering systems, the generic saddle-center scenario leads to stable islands in phase space. Non-interacting particles whose initial conditions are defined in such islands will be trapped and form rotating rings. This result is generic and also holds for systems quite different from planetary rings.Comment: 10 pages, 5 ps figures; uses elsart.sty and epsfig.sty Accepted in Phys. Lett.

The use of theatre for development in the prevention of HIV/AIDS : a dissertation presented in partial fulfilment of the requirements for the degree Master of Philosophy in Development Studies at Massey University

Over the last three decades development practitioners have begun to search for new theoretical approaches to the problems of underdevelopment. This has given rise to approaches that focus on the participation of people and their culture in development programs. The teachings of Paulo Freire, latterly developed by Augusto Boal, gave voice to theatre that is participatory, provides two-way communication and aims to raise the critical awareness of spectators. This form of theatre is known as Theatre for Development. It aims to promote awareness of political, social and economic issues. Theatre for Development goes beyond the theatrical event giving people skills to confront problems and solve them. The AIDS pandemic is a human tragedy that is threatening development in the world's poorest countries. In fact, 95 per cent of people with HIV or AIDS live in developing countries. HIV accentuates inadequacies that exist in health care infrastructures and highlights social and economic inequalities. There is no known cure for this disease but through systematic national programs that focus on preventing HIV transmission it is possible to significantly lower infection rates. Theatre should be part of any national HIV/AIDS program. Theatre for Development is effective in communicating HIV/AIDS related information and promoting attitude changes. Theatre has many advantages as an educational technique; it engages participants, is appropriate to the local situation, adapts to indigenous cultures, assists with skill development and encourages discussion about sensitive issues. In Vanuatu, Wan Smolbag theatre uses Theatre for Development to provide people with the knowledge and skills required to prevent HIV/AIDS infection. The mainstay of this Non Governmental Organisations' (NGO) work is short interactive theatre pieces of 20 to 50 minutes. In addition, WSB has created videos, radio dramas and educational materials. WSB's HIV/AIDS theatre is based on the Freiran concepts of participation and dialogue. As a consequence, the group's theatre reflects the lives of its participants and is proving that theatre can be a powerful tool for improving people's knowledge of HIV/AIDS

Towards an Emotionally Conscious Social Theory

This article attempts to contribute to the on-going discussion regarding the 'future of sociology and social theory' by suggesting that classical and contemporary social theories have yet to provide satisfactory accounts of the emotional components of human society. Following a discussion of how emotions have been downplayed in classical and contemporary theory, evidence is presented in support of a sociology that would include the study of emotions as part of broader studies of the social. A central proposition of this article is that the harmonization of studies of 'micro' and 'macro' realities would facilitate the development of a systems theory that neither excludes diversity nor minimizes the immutable emotional needs of individuals and their social systems. In support of the above argument, the author presents some new evidence pointing to the primacy of the human emotions across cultural boundaries.Social Theory, Sociology of Emotions, Self, Identity, Micro, Macro, Postmodernism.

Origin of chaos in the spherical nuclear shell model: role of symmetries

To elucidate the mechanism by which chaos is generated in the shell model, we compare three random-matrix ensembles: the Gaussian orthogonal ensemble, French's two-body embedded ensemble, and the two-body random ensemble (TBRE) of the shell model. Of these, the last two take account of the two-body nature of the residual interaction, and only the last, of the existence of conserved quantum numbers like spin, isospin, and parity. While the number of independent random variables decreases drastically as we follow this sequence, the complexity of the (fixed) matrices which support the random variables, increases even more. In that sense we can say that in the TBRE, chaos is largely due to the existence of (an incomplete set of) symmetries.Comment: 21 pages, 3 ps-figures. Revised version to appear in Nucl. Phys. A. New text and figures adde

Phase-Space Volume of Regions of Trapped Motion: Multiple Ring Components and Arcs

The phase--space volume of regions of regular or trapped motion, for bounded or scattering systems with two degrees of freedom respectively, displays universal properties. In particular, sudden reductions in the phase-space volume or gaps are observed at specific values of the parameter which tunes the dynamics; these locations are approximated by the stability resonances. The latter are defined by a resonant condition on the stability exponents of a central linearly stable periodic orbit. We show that, for more than two degrees of freedom, these resonances can be excited opening up gaps, which effectively separate and reduce the regions of trapped motion in phase space. Using the scattering approach to narrow rings and a billiard system as example, we demonstrate that this mechanism yields rings with two or more components. Arcs are also obtained, specifically when an additional (mean-motion) resonance condition is met. We obtain a complete representation of the phase-space volume occupied by the regions of trapped motion.Comment: 19 pages, 17 figure