Composition and dynamics of plasma in Saturn's magnetosphere.

During Cassini's initial orbit, we observed a dynamic magnetosphere composed primarily of a complex mixture of water-derived atomic and molecular ions. We have identified four distinct regions characterized by differences in both bulk plasma properties and ion composition. Protons are the dominant species outside about 9 RS (where RS is the radial distance from the center of Saturn), whereas inside, the plasma consists primarily of a corotating comet-like mix of water-derived ions with approximately 3% N+. Over the A and B rings, we found an ionosphere in which O2+ and O+ are dominant, which suggests the possible existence of a layer of O2 gas similar to the atmospheres of Europa and Ganymede.

Amount and distribution of fume contaminants in the lungs of an arc welder post mortem.

This study describes various post-mortem examinations of the lungs of a shipyard arc welder. These investigations comprised morphological methods, including gross pathology and radiography, histological and ultrastructural examinations, chemical analysis of lung tissue, and sensitive magnetic measurements, which can now be used to detect magnetic contaminants, such as welding fume, in human tissue. Such methods can also show the distribution of contaminants. The amount of welding-fume contaminants was low, only 110 mg. The contaminant iron seemed to represent only 10% of the total iron chemically analysed in lung tissue. The concentration of the total iron was 4-10 times higher than that in control tissue. Contaminants tended to collect in the central areas of the lungs. Two concentration centres could be observed in each lung, one anterior and one posterior. There was slight fibrosis around pigmented areas. Histological findings were similar to those of previous studies. Transmission electron micrographs showed that enlarged lysosomes of macrophages contained electron-dense granules, 450 nm to less than 5 nm in diameter, which formed aggregates and short chains, and resembled welding-fume particles in the breathing zone. Our results show the value of studying the same material by a number of inter-related methods.