Experimental evidence has been found for consecutive projectile-target-projectile (triple) and projectile-target-projectile-target (quadruple) "ping-pong" scattering of ionized target electrons in single C+ +Xe collisions at 150 and 233 keV/u impact energies. Distinct signatures of the multiple electron scattering contributions to the high-energy part (300-3400 eV) of the double differential electron spectra have been separated and identified with the help of reference measurements using He+ projectile ions and different calculations.

Ability to produce megacin A, a bacteriocin of B. megaterium, was transferred from the strain B. megaterium 216 into auxotrophic derivatives of the strain B. megaterium KM via protoplast fusion and polyethylene-glycol-induced protoplast transformation by plasmid DNA, respectively. A 30.9 megadalton plasmid was detected in cells with MegA phenotype, and the loss of this phenotype was accompanied in each case with the elimination of that plasmid. The megacinogenic plasmid pBM309 has a single site for both BamHI and XhoI. It is cleaved by the endonucleases SalI, BglII, PstI, PvuII, and EcoRI into 3, 3, 4, 4, and 9 fragments, respectively. The physical map of this plasmid is presented.

A new setup for measuring partial photoion yields was developed and built at the Synchrotron Radiation Center. The vacuum chamber, which accommodates an ion time-of-flight spectrometer, a metal vapor oven, and a liquid nitrogen cooled trap, consists mainly of a standard conflat 6 in. six-way cross and a 6 in. tee. A differential pumping stage separates the vacuum chamber from the beam line. First experiments with this apparatus were performed using neon, lithium, and beryllium.

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