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This is a brief account of our numerical study of the tearing mode reconnection. We demonstrate two main points. First, we show that, given sufficiently small resistivity, the Rutherford regime always exists; larger values of Delta' require smaller values of resistivity. Rutherford's negligible-inertia assumption is validated and the asymptotically linear dependence of the time derivative of the island width on the resistivity and Delta' is confirmed. Second, we find that, at large Delta', the Rutherford regime is followed by a nonlinear stage of fast growth linked to X-point collapse and formation of a current sheet. This causes the reconnection to become Sweet-Parke (SP) like. The signature resistivity^{1/2} scaling of the effective island growth rate is, indeed, found in this nonlinear stage. The SP stage culminates in the saturation of the mode, which can, thus, be achieved much faster than via Rutherford regime., Comment: latex, 4 pages, 8 figures; Paper 4-208, Proceedings of the 31st EPS Conference on Plasma Physics, London 28 June - 2 July 2004

Using a linear theory the dispersion relation of electrothermal waves in a seeded, partially ionized gas is derived. Two modes appear, one of which is always damped, while the other is unstable in certain plasma situations. This is the ionization instability and the growth rate has been calculated as a function of the steady state electron temperature, the angle between the steady state current density and the wave vector, the Hall parameter, and the instability wavelength.