Norm and essential norm of differences of differentiation composition operators between Bloch spaces have been estimated in this paper. As a result, we find characterizations for boundedness and compactness of these operators.

The fossilization of organic remains and shell material by calcium phosphate minerals provides an illuminating, but time-bounded, window into Ediacaran–Cambrian animal evolution. For reasons that remain unknown, phosphatic fossil preservation declined signifi cantly through Cambrian Series 2. Here, we investigate the phosphorus (P) sources for phosphatic Cambrian carbonates, presenting sediment...

This review of the current knowledge of impact spherule layers in the Barberton greenstone belt, together with new petrographic, geochemical, and field data on a number of impact and volcanic spherical particle horizons, highlight a number of problems with the proposition of frequent and large meteorite impacts during mid-Archean times. Field data indicate that some of the four previously propo...

Analyses of bulk petrographic data indicate that during the Late Paleozoic wildfires were more prevalent than at present. We propose that the development of fire systems through this interval was controlled predominantly by the elevated atmospheric oxygen concentration (p(O2)) that mass balance models predict prevailed. At higher levels of p(O2), increased fire activity would have rendered vege...

We present a proof that in Orlicz spaces the Amemiya norm and the Orlicz norm coincide for any Orlicz function ‘p. This gives the answer for an open problem. We also give a description of the Amemiya type for the Mazur-Orlicz F-norm.