Contribución al conocimiento biológico del calamar argentino Illex illecebrosus argentinus

The present work deals with the biological study of the squid Illex illecebrosus argentinus of the Buenos Aires area (Argentina) in the southwest Atlantic ocean. According to recent research (Voss, pers. comm.) the squid obtained in commercial fishing in the waters off Buenos Aires Province (Castellanos), which in proper of the S.W. Atlantic. The material studied comes from commercial fishing done in in two sectors: one ranging from 36~' to 37~' S, and the other from 39~' to 42~' S in latitude, while both extend from 55~' to 62~' W in longitude. The fishing area varies during the years, being located more towards the North in summer and more towards the South in winter, following the fishing of hake. The number of individuals studied was 186. Their total length ranged from 195 mm to 670 mm for both sexes. The sampling showed that the males had lesser length and weight than the females: that is, a secondary sexual dimorphism was observed. At the length of 240 mm the squid reaches its sexual maturity. Sexual activity is observed the year around, but not simultaneously for the whole population, that is to say, spawning does not take place en masse but, on the contrary, it occurs during a prolonged period. In summer, from December to March, the greatest spawning period is observed. This takes place in the same habitat for the whole squid population. The squid herein studied is a cold water species, the water temperature ranging from 5~' to 12~' C in the sites of the largest catches. The squid is caught at depths ranging from 7 to 250 meters with a trawl net. In Patagonian waters, somewhat smaller individual are caught with 'poteras' at depths ranging from 1 to 8 fathoms.

Finite element solution of Navier Stokes equations adapted to a priori error estimates

The paper is based on qualitative properties of the solution of the Navier-Stokes equations for incompressible fluid, and on properties of their finite element solution. In problems with corner-like singularities (e.g. on the well-known L-shaped domain) usually some adaptive strategy is used. In this paper we present an alternative approach. For flow problems on domains with corner singularities we use the a priori error estimates and asymptotic expansion of the solution to derive an algorithm for refining the mesh near the corner. It gives very precise solution in a cheap way. We present some numerical results.

湖南尖吻蝮蛇毒出血毒素的圆二色性和化学修饰

用远紫外CD谱研究了湖南产尖吻蝮蛇毒的两个出血毒素(DaHT-1、DaHT-2)的溶液构象, 计算得DaHT-1的#alpha#螺旋、#beta#折叠、无规卷曲的含量分别为36.9%, 35.5%, 27.6%; DaHT-2的#alpha#螺旋、#beta#折叠、无规卷曲分别为23.4%, 31.3%, 45.3%。随pH的增大或减小。温度和pH对CD谱的影响相似。0.02mol/L EDTA便导致两个出血毒素呈极度的无序状态。胰蛋白酶不影响它们的出血活性。图4表4参10