In order to provide mobile worldwide communication services, cellular systems can be based on a multilayered, multisized cells architecture characterized by the use of different technologies. Satellites can cover lightly populated areas, as well as those areas where other means cannot be used (like the sea); ® xed base stations, with different transmission powers and thus different cell sizes, ...

Teaching how to develop medium size information systems in courses with high matriculation rates is a complex task. In Latin America this is an important issue because, due to high matriculation rates and scarce resources, Schools of Engineering have, in general, very low graduation rates and high drop-out rates. This paper presents the experiences of a team of teachers, during a period of eigh...

The sequencing of the Mycobacterium tuberculosis (MTB) H37Rv genome has facilitated deeper insights into the biology of MTB, yet the functions of many MTB proteins are unknown. We have used sensitive profile-based search procedures to assign functional and structural domains to infer functions of gene products encoded in MTB. These domain assignments have been made using a compendium of sequenc...

Introduction The wide use of computer graphics in games, entertainment, medical, architectural and cultural applications, has led it to becoming a prevalent area of research. At the current stage of technology, users can interactively navigate through complex, polygon-based scenes rendered with sophisticated lighting effects and high quality antialiasing techniques. Animated characters (or agen...

We calculated the median values of the following parameters for 87 groups of galaxies with three to eight components: the mean rms velocity of the galaxies in the group, Sv = 166 km/s; the harmonic mean radius, Rh = 29 kpc; and the mass-to-light ratio, Mvir/L = 33M⊙/L⊙. The Mvir/L ratio depends on the population of the system, while Sv does not depend on Rh. To ascertain the relationship betwee...

The problem of learning maps with mobile robots has received considerable attention over the past years. Most of the approaches, however, assume that the environment is static during the data-acquisition phase. In this paper we consider the problem of creating maps with mobile robots in populated environments. Our approach uses a probabilistic method to track multiple people and to incorporate ...

BACKGROUND Few studies have attempted to understand the complexity of microbial populations in Pakistan where infectious diseases are prevalent. This study was undertaken to assess bacterial biodiversity in Nehr-e-Khayyam a heavily polluted stream connected to the Arabian Gulf, which runs through a densely populated urban area in Karachi, Pakistan. METHODS Employing a universal pair of oligon...

Bell's introduction of the fibroblast-populated collagen lattice (FPCL) has facilitated the study of collagen-cell interactions. As a result of the numerous modifications of the casting of FPCLs, the in vivo applications of these in vitro findings have been confusing. Here experimental FPCL contraction findings are viewed in regard to three proposed mechanisms responsible for lattice contractio...