Chloroplast DNA of the protozoan flagellate, Euglena gracilis, exists as circular molecules, 40 mum in contour length, as shown by electron microscopy and buoyant density analyses.

It is generally argued that most clusters of galaxies host cooling flows in which radiative cooling in the centre causes a slow inflow. However, recent observations by Chandra and XMM conflict with the predicted cooling flow rates. Here we report highly resolved hydrodynamic simulations which show that buoyant bubbles can offset the cooling in the inner regions of clusters and can significantly...

35S-Labeled proteoglycans produced by chondrocytes from immature and mature rabbits were fractionated on associative CsCl gradients. In all cultures, greater than 85% of the incorporated radioactivity was present in the A1 fraction (rho 1.60) as chondroitin sulfate/keratin sulfate-substituted aggregating proteoglycan monomer; the remainder was present in small proteoglycans in the A2, A3, and A...

Synthesis and turnover of nitrate reductase molecules and soluble proteins of tobacco XD cells were studied by labeling pre-existing proteins with 14C-arginine to make them radioactive and with 99 atom % ‘5N to increase their buoyant density. The cells were then transferred to medium in which new proteins were synthesized from 14N and were radioactively labeled with 3H-arginine. The breakdown o...