Plasmodium berghei: The effect of five protease inhibitors, TPCK, TLCK, PMSF, leupeptin, and 1,10-phenanthroline on in vitro gametogenesis and early zygote development of P. berghei was investigated. PMSF and leupeptin showed no effect. Cysteine/serine protease inhibitors TPCK/TLCK at concentrations of 75 and 100μM were effective on inhibiting exflagellation center formation, and this effect was reversible with the addition of l-cysteine. Exflagellation center formation was most effectively blocked by 1,10-phenanthroline (1mM), and exflagellation center numbers were restored by the addition of Zn2+. A reduction of ookinete production was observed when TPCK/TLCK (100μM) was added at 2h after gametogenesis, but no effect was observed with 1,10-phenanthroline (1mM). Our results suggest that proteolysis is important in both gametocyte activation and sexual development of P. berghei.

In this paper, we propose the use of the Belief-Desire-Intention (BDI) model for cognitive agents for the implementation of animated characters. The BDI agent architecture has been widely used in dynamic and complex scenarios where agents may need to act under incomplete and incorrect information about other agents and the environment. In this work, we bring together an articulated model for character animation and an interpreter for AgentSpeak(L), an agent-oriented programming language that implements the BDI architecture. We have developed an interface that allows the BDI-based agent reasoning system to be used for guiding the behaviour of articulated characters in a virtual environment. This is a promising approach for the high-level specification of complex computer animations. The paper also presents a simple 3D animation that illustrates the use of BDI specifications in our approach.

This study is a contribution towards the understanding of the mode of action of Shiva-3 and more generally that of cecropin-like peptides. Structural information on Shiva-3 (a cecropin-like synthetic peptide) in water and in a membrane-mimicking environment (trifluoroethanol alcohol, SDS) were obtained using analytical centrifugation, CD and NMR spectroscopies. A total of 20 converged structures were retained on the basis of 197 non-redundant experimental constraints, including 166 distance constraints from the nuclear Overhauser effect measurements and 31 dihedral angle restraints derived from the purged COSY experiments. Some results obtained in presence of SDS are also presented. The toxic effects of the peptides obtained by cleavage (trypsin and lysine-C hydrolysis) of Shiva-3 on Escherichia coli and on Plasmodium berghei sporogonic stages are reported. Biological effects are discussed in relation to the calculated structure. The antiparasite activity and the low mosquito toxicity of Shiva-3 make this peptide a good candidate for genetic transformation of mosquito vectors which warrants further studies aimed at the improvement of the molecule.

The effect of a synthetic cecropin-like peptide, Shiva-3, on in vitro ookinete development and on the early sporogonic stages of Plasmodium berghei in the midgut of Anopheles albimanus was investigated. Peptide concentrations of 75 and 100 μM were effective (P < 0.05) in reducing ookinete production and the number of infected mosquitoes in almost all experiments. These peptide concentrations in the midgut were not toxic for the survival of the mosquitoes. Complete inhibition was obtained if 100 μM Shiva-3 was applied in the first 8 hr of parasite development. The deleterious effect of the peptide on the parasite was effective after exposure for as short as 50 sec and the permanence of free peptide in the mosquito midgut was estimated to be of a minimum of 5 min. These observations indicate the possibility of using Shiva-like peptide genes to engineering malaria-resistant vectors as an alternative in malaria control strategies.

Three morphologically different pupal phenotypes (green, striped, brown) were selected from a parent strain of Anopheles albimanus Wiedemann collected from the Suchiate region in the state of Chiapas, Mexico. Significant differences in susceptibility to coindigenous Plasmodium vivax Grassi & Feletti were observed when striped was compared with the parent colony as well as with brown and with green phenotypes. Differences in susceptibility were not significant between the other phenotypes and the parent colony.

A natural way for developing characters that are able to react appropriately to unexpected events and circumstances is by the use of artificial in- telligence techniques, in particular those related to the areas of autonomous agents and multi- agent systems. In this paper, we propose the use of the Belief-Desire-Intention (BDI) model of cognitive agents for the implementation of an- imated characters. In order to do so, we have integrated an articulated model for character an- imation and an interpreter for AgentSpeak(L), an agent-oriented programming language based on the BDI architecture. In particular, this ap- proach is suitable for characters that may need to act on multiple foci of attention, and is therefore a promising approach for the high-level speci- fication of complex computer animations. We illustrate our approach with an animation of a storehouse robot.

This paper proposes an architecture to implement autonomous synthetic actors in virtual worlds. These actors are represented by an articulated structure and have cognitive reasoning using BDI logic. Such architecture uses an interpreter for AgentSpeak language developed by the Artificial Intelligence group at UFRGS, and an articulated body animation model. This work suggests the development of a communication interface between the two systems described above, using sockets. Resumo. Este artigo propõe uma arquitetura para implementar atores sintéticos autônomos em ambientes virtuais que combinam raciocínio cognitivo usando lógica BDI e representação e movimentação do corpo usando uma estrutura articulada. A arquitetura apresentada utiliza um interpretador para a linguagem AgentSpeak, desenvolvido pelo grupo de Inteligência Artificial da UFRGS, e um modelo de corpo articulado com animação e propõe uma interface de comunicação entre os dois sistemas utilizando sockets.