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International audience; In this paper, we describe SAFlex (Structural Alphabet Flexibility), an extension of an existing structural alphabet (HMM-SA), to better explore increasing protein three dimensional structure information by encoding conformations of proteins in case of missing residues or uncertainties. An SA aims to reduce three dimensional conformations of proteins as well as their analysis and comparison complexity by simplifying any conformation in a series of structural letters. Our methodology presents several novelties. Firstly, it can account for the encoding uncertainty by providing a wide range of encoding options: the maximum a posteri-ori, the marginal posterior distribution, and the effective number of letters at each given position. Secondly, our new algorithm deals with the missing data in the protein structure files (concerning more than 75% of the proteins from the Protein Data Bank) in a rigorous proba-bilistic framework. Thirdly, SAFlex is able to encode and to build a consensus encoding from different replicates of a single protein such as several homomer chains. This allows localizing structural differences between different chains and detecting structural variability, which is essential for protein flexibility identification. These improvements are illustrated on different proteins, such as the crystal structure of an eukaryotic small heat shock protein. They are promising to explore increasing protein redundancy data and obtain useful quantification of their flexibility.

In a public network, it is unlikely for a node which has limited resources to collaborate without gain. For avoidance of the fact that nodes refuse to cooperate in MANET, several schemes classified as reputation-based and credit-based, are considered suitable for ad-hoc networks, whereas many of these schemes are based on proactive or reactive routing protocols but none of them is based on a hybrid routing protocol. In this paper, we propose a new cooperation enforcement protocol for a hybrid routing protocol called AntTrust. This new protocol uses the nodes’ reputation to forward packets through the most reliable nodes. The main idea of the protocol is to provide an effective mechanism to measure the reputation of other nodes of the network and to punish all nodes which do not collaborate into the network. sciences of electronics,technologie of information and telecommunication(2012)