In this paper we discuss and confront recent results on metallicity variations in the local interstellar medium, obtained from observations of H II regions and...

We address one of the lingering mysteries of high-velocity clouds: If the anomalous negative velocities are the result of the approaching gas from old...

Contents: The classical scheme for gas phase reactions. Charge transfer at low energies. Electron abundances in dense clouds. Some problems in interstellar S...