In the size range from lO-4 to 10’ pg (carbon) body weight, the biomass of plankton in the euphotic layer of the North Pacific Central Gyre decreases as an allometric function of body weight. Even in a steady state ecosystem such as that analyzed here, there is variability in space and time; this suggests that one must be careful in extrapolating the relation to less predictable marine areas. I...

This thesis is dedicated to the study of the magnetic properties of GaMnAs nanometric layers by the ferromagnetic resonance (FMR) technique. Three series of samples have been studied to investigate independently the influence of the strain, the hole concentration and the Mn concentration on the magnetic properties of GaMnAs. In the first series, the Ga1−xMnxAs samples with x=0.07, grown on GaAs...

This paper describes the isolation and characterization of rhamnogalacturonan II, a hitherto unobserved component of the primary ceo wails of dicotyledonous plants. Rhamnogalacturonan II constitutes 3 to 4% of the primary ceo wais of suspension-cultured sycamore (Acerpseudoplatanus) cels. Rhamnogalacturonan II is a very complex polysaccharide yielding, upon hydrolysis, 10 different monosacchari...