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Abstract. Model studies are presented, each of which employs a different approach to solving the problem of nonadiabatic dynamics occurring at a solid surface. The jumping wave packet-type approach involving dynamics on two potential energy surfaces punctuated by Franck-Condon transitions was applied to the dynamics of CO desorbed from Ru following energetic electron bombardment. Classical dynamics was also employed in this system to gain a more detailed understanding of the factors important to the final molecular state distribution. To study charge transfer from an alkali-halide surface to a scattering atom, we have used full multi-surface quantum dynamics. A simple, but effective, analysis method was used to make a more detailed connection between the potential energy surfaces and the dynamics. To study the fate of the transferred electron and to model how this depends on substrate and projectile species, we have used a four-dimensional wave packet implementation in which two of the dimensions explicitly account for the electron dynamics. Finally, we consider the famous electron-hole pair excitation problem, from a density functional theory perspective. Spin nonadiabaticity is found to be a new important feature in gas-metal surface interactions. [ABSTRACT FROM AUTHOR]

Community-acquired respiratory distress syndrome toxin (CARDS TX) is a 591-amino-acid protein with ADP-ribosyltransferase and vacuolating activities that damages the cells lining the respiratory tracts of patients infected with the bacterial pathogen Mycoplasma pneumoniae. Crystals of CARDS TX were grown in space group C2, with unit-cell parameters a = 191.4, b = 107.4, c = 222.1 Å, β = 90.6°. A complete 2.2 Å data set was obtained from a single CARDS TX crystal. [ABSTRACT FROM AUTHOR]

Summary Single nucleotide substitutions were made in the core helices P4, P6, and P7, and in the metal-binding GAAA motif in the J4/5 region of the chloroplast group I rRNA intron of Chlamydomonas reinhardtii , Cr.LSU . In vitro assays showed that these substitutions had surprisingly strong effects on Cr.LSU self-splicing; however, splicing of all but the P6 mutations could be at least partially recovered by increasing the Mg2+ concentration. The mutant constructs were transformed into chloroplasts to replace the wild-type intron; however, only the P4 mutants became homoplasmic, indicating that the other mutations were lethal. The splicing-deficient P4125 A mutant, which exhibited slow growth and light sensitivity, was used to isolate suppressor strains that showed a substantial restoration of Cr.LSU splicing. Genetic analysis of the 7151, 7120 and 71N1 suppressors indicated that these mutations are in at least two nuclear genes. The 7151 suppressor mutation, which defines the chloroplast-splicing suppressor (css1 ) gene, had no obviously altered growth phenotype with the wild-type intron, and was dominant in vegetative diploids containing the mutant intron. All three of the suppressor strains also suppressed a mutation in the P4 region of the fourth psbA intron, Cr.psbA4 , indicating that these genes play a role in splicing of multiple group I introns in the chloroplast. [ABSTRACT FROM AUTHOR]