The African seal, heliophoca Atlantica

Brightness discrimination in the South African fur seal (Arctocephalus pusillus)

Underwater, the contrast between object and background is much larger reduced with increasing distance between object and observer than in air. For marine predators, such as pinnipeds, it would therefore be advantageous to possess a high sensitivity for brightness differences, since this would increase the distance at which prey can be detected visually. Few studies have examined the brightness...

Apical seal versus coronal seal

the results of the initial study. It was concluded that the apical fluids, with their primary source being blood serum, diffuse into the empty canal spaces, stagnate, undergo degradation and then act as a physicochemical irritant when they diffuse back into periapical tissues. In support of this theory of stagnation, in 1955 Dow and Ingle showed that the majority of the endodontic failures were...

The UNESCO Seal of Excellence for Handicrafts

The UNESCO Seal of Excellence for Handicrafts

The Seal Calculus

The Seal Calculus is a process language for describing mobile computation. Threads and resources are tree structured; the nodes thereof correspond to agents, the units of mobility. The Calculus extends a π-calculus core with synchronous, objective mobility of agents over channels. This paper systematically compares all previous variants of Seal Calculus. We study their operational behaviour wit...