11 research outputs found
The Picard and the Gauss-Weierstrass singular integrals of functions in two variables
We study some approximation properties of the Picard and the Gauss-Weierstrass singular integrals of functions of two variables belonging to some exponential weighted spaces. In Sec. 3.1 and 3.2 we give two theorems on the degree of approximation and two theorems of the Voronovskaya type. In Sec. 3.3 the Bernstein inequalities for these singular integrals are proved.Some similar results for the Picard and the Gauss-Weierstrass singular integral of functions of one variable were given in [1] - [3]
Length-weight relationships and condition factor of eight fish species inhabiting the Rocha Lagoon, Uruguay
Cytogenetic characterization of the Arabidopsis thaliana natural tetraploid ecotype Warschau stability during in vitro regeneration
Seasonal composition, abundance and biomass of the subestuarine fish assemblage in SolĂs Chico (RĂo de la Plata estuary, Uruguay)
Abstract The large estuaries can present long narrow branches called subestuaries or tidal creeks. These types of subsystems are distributed along the Uruguayan coast of the RĂo de la Plata estuary and are very important as nursery and refuge areas for fish. For the first time, the seasonal composition and abundance of the fish community of the SolĂs Chico subestuary was studied by using beach and gill nets. Fourteen species, mainly euryhaline (86%) presented a significant representation of juvenile stages. The fish community was dominated by Odontesthes argentinensis, Platanichthys platana, Mugil liza, Brevoortia aurea, Micropogonias furnieri and Paralichthys orbignyanus, similar to adjacent subestuaries. While Micropogonias furnieri and B. aurea were the most abundant species, some other species were rarely caught. A seasonal variation of the fish assemblage abundance was detected, with higher values in autumn showing a positive correlation with temperature. Species that complete their life cycle in the RĂo de la Plata estuary, some of which are relevant to fisheries (64% of the analyzed species) were captured in the SolĂs Chico subestuary. The importance of this environment as a transitional system for some estuarine fish species is advised