Taxonomy of the spring dwelling amphipod Synurella ambulans (Crustacea: Crangonyctidae) in West Russia: with notes on its distribution and ecology

This study deals with taxonomic problems of the semi-subterranean crangonyctid amphipod Synurella ambulans (F. Müller, 1846), well-known from various freshwater habitats in Europe. The taxonomy of the species S. ambulans and the generic diagnosis for the genus Synurella are revised. A new synonymy is proposed: Synurella ambulans (F. Müller, 1846) = Synurella ambulans meschtscherica Borutzky, 1929, syn. nov. The affinity with the related groups, distribution and ecology of the species are examined

About discrete hedging and option pricing

The approach that allows find European option price on the assumption of hedging at discrete times is proposed. The routine allows find the option price not for lognormal distribution functions of underlying asset only but for other classes of distribution functions too. It is shown that there exists a nonzero possibility that market parameters can take values such that to realize the hedging policy becomes impossible. This fact is not in contradiction with Black-Scholes option price model as long as this possibility tends to zero at the limit of continuous hedging.option pricing model, finance mathematical model, discrete hedging