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We propose to interpret the stellar IMF as a property of the turbulence in the star-forming gas. Gravitationally unstable density enhancements in the turbulent flow collapse and form stars. Their mass distribution can be derived analytically from the power spectrum of the turbulent flow and the isothermal shock jump conditions in the magnetized gas. [ABSTRACT FROM AUTHOR]

Calculations of the properties of point defects in metals by computer simulations have the enormous advantages over other classes of materials since, to first order, charge exchange and angular forces can be neglected, thereby greatly reducing the computational effort. Moreover, the structure, concentration and diffusivity of both the vacancy and interstitial defects are known experimentally in a number of metals, so that a solid base of information is available to validate the simulation models employed. In this article we will first briefly summarize this base of experimental knowledge and then discuss current state of the art methods for calculating the properties of defects in metals, citing notable successes and failures. Each subsection is laid out discussing first the ground state energies of the defect structures, then the defect concentration (or entropy), and finally the migration properties of the defects. In the last section, we will briefly examine attempts to apply the concepts of defect structures in crystalline structures to metallic glasses. [ABSTRACT FROM AUTHOR]

The article presents general economic indicators, indicators pertaining to the costs of social welfare and indicators pertaining to labour market conditions and unemployment in the Nordic countries. A large number of possible indicators are available and are more or less appropriate, depending on the specific question. The general idea here is to choose indicators dealing with how conditions in the different Nordic countries have changed in relation to each other and in relation to other industrialized countries. To avoid some of the problems of comparability of data, the sources are international or Nordic bodies. The article also deals with indicators of political structures. The indicators include data on national elections and government composition during the last 15 years. The article concludes that a number of different economic indicators show that the four Nordic countries have taken rather different paths after 1980. Finland and Sweden both experienced the effects of a deep economic crisis that followed the international recession in 1991. Denmark was affected but to a lesser degree, partly because Denmark already had higher levels of unemployment and partly because of its much earlier attempts to restructure the country's economy. Norway was the least affected, and this is largely due to its oil resources.

We simulate in one dimension the magnetic shearing instability for a vertical magnetic field penetrating a Keplerian accretion disc. An initial equilibrium state is perturbed by adding a single eigenmode of the shearing instability and the subsequent evolution is followed into the nonlinear regime. Assuming that the perturbation is the most rapidly growing eigenmode, the linear theory remains applicable until the magnetic pressure perturbation is strong enough to induce significant deviations from the original density. If the initial perturbation is not the fastest growing mode, the faster growing modes will appear after some time. [ABSTRACT FROM AUTHOR]

A magnetically dominated plasma driven by braiding motions on boundaries at which magnetic field lines are anchored is forced to dissipate the work being done upon it, no matter how small the electrical resistivity may be. Recent numerical experiments have clarified the mechanisms through which balance between the boundary work and the dissipation in the interior is achieved. The results largely confirm Parker's (1972) idea of "topological dissipation"; dissipation is achieved through the formation of a hierarchy of electrical current sheets. Current sheets form as a result of the topological interlocking of individual strands of magnetic field. The average level of dissipation is well described by a scaling law that is independent of the electrical resistivity. [ABSTRACT FROM AUTHOR]

The magnetic shear instability appears to be a workable mechanism for generating turbulence in accretion discs. The magnetic field, in turn, is generated by a dynamo process that taps energy from the Keplerian shear flow. Large scale magnetic fields are generated, whose strength is comparable with, or in excess of, the turbulent kinetic energy. Such models enable us to investigate the detailed nature of turbulence in discs. We discuss in particular the possibility of generating convection, where the heat source is viscous and magnetic heating in the bulk of the disc. [ABSTRACT FROM AUTHOR]