[en] In the general area of confinement improvement and concept advancement, recent results in the MST reversed-field pinch include 1) improved confinement at 500 kA plasma current, with copious energetic electrons and sustained elevated ion temperature greater than 1 keV; 2) raised density in improved-confinement plasmas from injection of frozen deuterium pellets; 3) sustainment of 10% of the plasma current by oscillating field current drive (ac helicity injection), in agreement with theory for the applied power; 4) wave injection from electron Bernstein wave and lower hybrid wave antennas, satisfying theoretical expectations of plasma loading at power levels of about 100 kW. Substantial progress has been made in understanding the causes and effects of magnetic reconnection in the RFP: 1) discovery that fast ions with large gyro-radii are well-confined in the standard RFP, despite the underlying stochasticity of the magnetic field; 2) determination that ion heating during reconnection events appears to be localized to the reconnection layer; 3) observation that global magnetic self-organization (characterized by sudden changes in magnetic energy, plasma momentum, and ion temperature) occurs only when spontaneous (m = 1) and driven (m = 0) reconnection are present simultaneously. Diagnostic system development continues, including charge-exchange recombination spectroscopy for fluctuation measurement, multi-point and multi-pulse Thomson scattering, spectral motional Stark effect measurement of low-field vertical bar B vertical bar, and multi-color soft x-ray detector arrays for tomographic measurement of time-resolved electron temperature. (author)