The Curvature Operator of the Second Kind in Dimension Three.

This article aims to understand the behavior of the curvature operator of the second kind under the Ricci flow in dimension three. First, we express the eigenvalues of the curvature operator of the second kind explicitly in terms of that of the curvature operator (of the first kind). Second, we prove that -positive/ -nonnegative curvature operator of the second kind is preserved by the Ricci flow in dimension three for all .

Computed vs. film-based radiographs' contour artifacts influence diagnosis of secondary caries.

To test local grey-scale changes on dental bitewing radiographs near filling margins for image acquisition. Forty approximal preparations in caries-free amalgam filled teeth and bitewing radiographs were acquired under standardized conditions applying four techniques. Film-based analog radiographs were digitized using flat-bed scanner (FDR).

Timing and body condition of dichromatic Black Redstarts during autumn migration.

Individual variation in postjuvenile molt in male Black Redstart is pronounced with about 90% of young males retaining female-like coloration ( plumage type) and about 10% acquiring adult male-like feathers ( plumage type). We examined whether autumn migration timing and body condition differed between individuals of the two plumage types. We used the data of 10,977 Black Redstarts captured during autumn at a ringing site in northern Switzerland where a protocol to record plumage types of captures has been applied since 1980.