We present a stochastic model for the size of a taxon in paleobiology, in which we allow for the evolution of new taxon members, and both individual and catastrophic extinction events. The model uses ideas from the theory of birth and death processes. Some general properties of the model are developed, and a fuller discussion is given for specific distributions of the time between catastrophic ...

This study investigates the microbial community composition in the biofilms grown on two different support media in fixed biofilm reactors for aerobic wastewater treatment, using next generation sequencing (NGS) technology. The chemical composition of the new type of support medium (TDR) was found to be quite different from the conventionally used support medium (stone). The analysis of 16S rRN...

A new taxon Oncocnemis michaelorum srnkai Beshkov, ssp. n. is described from the Balkan Peninsula, Bulgaria. The subspecies, in comparison with other European members of confusa (Freyer, [1839]) species group, shows differences both outward appearance and female male genitalia, including everted vesica. a local endemic race, found three localities close to each ca. 30 km NW Sofia. It abundant t...