BACKGROUND Laparoscopic cholecystectomy (LC) is taking the place of an effective and tested procedure in surgery, therefore it must not be inferior to the standard modality in any aspect. Some complications specific to the technique, however, are severe and complication rate seem to be higher than in standard open surgery. METHODS In this paper the authors report their guiding principles in a...

So far, two species of Neotherina Dognin have been recorded in Costa Rica. Neotherina imperilla (Dognin) occurs primarily at altitudes between 1100 and 1700 meters and Neotherina callas (Druce) which is widely distributed above 1100 meters. A third, new species, Neotherina xanthosa Sullivan and Chacón is described from altitudes above 2400 meters. Heterogeneity of the genus is discussed.

We present experimental demonstrations of in-building impulse radio (IR) ultra-wideband (UWB) link consisting of 100 m multi mode fiber (MMF) and 4 m wireless transmission at a record 4 Gbps, and a record 8 m wireless transmission at 2.5 Gbps. A directly modulated vertical cavity surface emitting laser (VCSEL) was used for the generation of the optical signal. 8 m at 2.5 Gbps corresponds to a b...

In this paper we use the O’Nan–Scott Theorem and Aschbacher’s theorem to classify the primitive permutation groups of degree less than 2500. MSC: 20B15, 20B10 1 Historical Background The classification of the primitive permutation groups of low degree is one of the oldest problems in group theory. The earliest significant progress was made by Jordan, who in 1871 counted the primitive permutatio...