Some Variations on Maxwell's Equations

In the first sections of this article, we discuss two variations on Maxwell's equations that have been introduced in earlier work--a class of nonlinear Maxwell theories with well-defined Galilean limits (and correspondingly generalized Yang-Mills equations), and a linear modification motivated by the coupling of the electromagnetic potential with a certain nonlinear Schroedinger equation. In the final section, revisiting an old idea of Lorentz, we write Maxwell's equations for a theory in which the electrostatic force of repulsion between like charges differs fundamentally in magnitude from the electrostatic force of attraction between unlike charges. We elaborate on Lorentz' description by means of electric and magnetic field strengths, whose governing equations separate into two fully relativistic Maxwell systems--one describing ordinary electromagnetism, and the other describing a universally attractive or repulsive long-range force. If such a force cannot be ruled out {\it a priori} by known physical principles, its magnitude should be determined or bounded experimentally. Were it to exist, interesting possibilities go beyond Lorentz' early conjecture of a relation to (Newtonian) gravity.Comment: 26 pages, submitted to a volume in preparation to honor Gerard Emch v. 2: discussion revised, factors of 4\pi corrected in some equation

Stories of pre-war, war and exile: Bosnian refugee children in Sweden.

While standardized questionnaires produce counts of isolated events, a semi-structured interview derives a story, a complex narrative in time and place. Ninety Bosnian refugee children and adolescents (ages 1-20), resettled in Sweden, were assessed in a semi-structured clinical interview designed to identify and offer support to children at risk. A family-child account of traumatic exposure was analysed quantitatively and qualitatively. Type-stories or clusters of experience were identified for three distinct periods: prior to war, during war, and after war in exile. The extent of trauma-stress exposure during each of these periods proved unrelated. Pre-war experience presented as preponderantly good and safe. Differences in child exposure during war and exile could be understood in relation to identifiable socio-demographic factors; particularly ethnic background, social class, child age and family size. Further, the stories derived cast light on the equity of Swedish refugee reception, exposing both egalitarian and discriminatory tendencies

On the virial coefficients of nonabelian anyons

We study a system of nonabelian anyons in the lowest Landau level of a strong magnetic field. Using diagrammatic techniques, we prove that the virial coefficients do not depend on the statistics parameter. This is true for all representations of all nonabelian groups for the statistics of the particles and relies solely on the fact that the effective statistical interaction is a traceless operator.Comment: 9 pages, 3 eps figure

Diffeomorphism Groups and Anyon Fields

We make use of unitary representations of the group of diffeomorphisms of the plane to construct an explicit field theory of anyons. The resulting anyon fields satisfy q-commutators, where q is the well-known phase shift associated with a single counterclockwise exchange of a pair of anyons. Our method uses a realization of the braid group by means of paths in the plane, that transform naturally under diffeomorphisms of R{sup 2}

Labor-Management Cooperation: Bath Iron Works\u27s Bold New Approach

An increasing number of employers and unions have found that the best way to compete in the marketplace and secure both profits for the firm and good jobs for workers is through cooperative worker-management relations. As Americans obtain more education, and with the changing nature of some work, employers increasingly find it appropriate to rearrange responsibilities and tasks to employees, who work sometimes as teams and other times as individuals. For their part, more highly educated employees express greater desire to participate in workplace decisions and have the knowledge and competence to undertake more tasks at the workplace. It is clearer now than in the past that creating value at the workplace is the joint responsibility of management and labor. To compete in the world market, Bath Iron Works must change. We must expand our vision to look at the big picture, instead of focusing on just a small piece of the world. In order to achieve the significant improvements necessary to better our performance on naval contracts, as well as enable us to enter into the commercial/industrial market, we must develop a rational plan that allows us to be the most efficient and competitive manufacturing organization in the world

Anharmonicity of flux lattices and thermal fluctuations in layered superconductors

We study elasticity of a perpendicular flux lattice in a layered superconductor with Josephson coupling between layers. We find that the energy contains ln(flux displacement) terms, so that elastic constants cannot be strictly defined. Instead we define effective elastic constants by a thermal average. The tilt modulus has terms with ln(T) which for weak fields, i.e. Josephson length smaller than the flux line spacing, lead to displacement square average proportional to T/ln(T). The expansion parameter indicates that the dominant low temperature phase transition is either layer decoupling at high fields or melting at low fields.Comment: 15 pages, 2 eps figures, Revtex, submitted to Phys. Rev. B. Sunj-class: superconductivit