Sex-specific difference in migration schedule as a precursor of protandry in a long-distance migratory bird.

Protandry, the earlier arrival of males at the breeding grounds relative to females, is common in migratory birds. However, due to difficulties in following individual birds on migration, we still lack knowledge about the spatiotemporal origin of protandry during the annual cycle, impeding our understanding of the proximate drivers of this phenomenon. Here, we use full annual cycle tracking data of red-backed shrikes Lanius collurio to investigate the occurrence of sex-related differences in migratory pattern, which could be viewed as precursors (proximate causes) to protandry.

Cellular shear stiffness reflects progression of arsenic-induced transformation during G1.

Cancer cells consistently exhibit decreased stiffness; however, the onset and progression of this change have not been characterized. To study the development of cell stiffness changes, we evaluated the shear stiffness of populations of cells during transformation to a carcinogenic state. Bronchial epithelial cells were exposed to sodium arsenite to initiate early stages of transformation.