Strong shear of azimuthal plasma rotation velocity and a large density profile modification from a hollow to peaked profiles were successfully obtained in a cylindrical magnetized plasma, using voltage biased electrodes. The shear region and density profiles could be finely controlled by changing the voltage biased position as well as by the magnetic field configurations. A low frequency (<4 kHz) density oscillation was identified as a drift wave type: propagation in the electron diamagnetic direction with a rigid rotation (Mach number M∼−1 at the edge), opposite to the direction of the edge plasma rotation with M∼1.

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Some plants have toxicities that are dangerous for humans. In the case of poisoning by toxic plants, a rapid and easy screening test is required for accurate medical treatment or forensic investigation. In this study, we designed specific primer pairs for identification of toxic plants, such as subgenus Aconitum, genus Ricinus, genus Illicium, and genus Scopolia, by internal transcribed spacer sequences of nuclear ribosomal DNA. Allied species of target plants, foods, and human DNA were not detected, but each primer pair provided a specific PCR product from the target plant using real-time PCR. This method can detect the subgenus Aconitum, genus Ricinus, and genus Scopolia with template DNA of 10 pg, respectively, and genus Illicium with 1 pg. Furthermore, each primer pair provided the exact PCR product from digested target plants in artificial gastric fluid. When a trace unknown plant sample in forensic investigation is collected from stomach contents, this PCR assay may be useful for screening toxic plants.

Repeated transition phenomena with abrupt reductions and jumps of the electron density were observed (flip–flop pattern in bistable systems), by voltage biasing to an inserted electrode in the inner region of a rf- (radio frequency-) produced, cylindrical magnetized plasma. These global, self-excited, density transitions and back ones between two states were accompanied by changes of the floating potential profile and the bias current under various parameters. Control of the staying time probability in one of two states with hysteresis loops was attempted, changing the bias voltage, which showed the importance of a sheath region as well as fine structural patterns.

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