Continuous flows in the plane.- New conditions for existence of invariant measures in ergodic theory.- Approximation and spectral multiplicity.- Approximation and invariance.- On some applications of probability methods to additive number theoretic problems.- Example of an ergodic measure preserving transformation on an infinite measure space.- Some results on convergence rates for weighted averages.- A note on ?-finite invariant measures.- Super-mean-valued functions and semipolar sets.- Liftings and derivation bases.- Lipschitz functions and the prevalence of strict ergodicity for continuous-time flows.- Weak ratio convergence of measures in infinite measure spaces.- Transformations without finite invariant measure have finite strong generators.- On the Araki-Woods asymptotic ratio set and non-singular transformations of a measure space.- Imbedding Bernoulli shifts in flows.- On the existence of a ?-finite invariant measure under a generalized Harris condition.- The Ambrose-Kakutani theorem and the poisson process.- Generalized martingales.- Local ergodic theorems for N-parameter semigroups of operators.