Some researchers, including Nancy Kedersha, a biologist at ImmunoGen (a biotechnology company in Cambridge, Massachusetts) who was one of the discoverers of vaults, think they regularly switch from open(ie, flowers) to closed (ie, barrels).
Mozilla says its latest version of open-sourced Firefox was downloaded 7.1 million times, while Microsoft reported last week that IE 9 was downloaded 2.35 million times.