MOTIVATION: Antibodies are an important class of biological drugs, but with limitations, such as inadequate pharmacokinetics, adverse immunogenicity and high production costs. Synthetic peptides for the desired target represent an important alternative to antibodies. However, no computational tool exists to guide the design of these peptides. RESULTS: To identify the interacting residues in a given antibody-antigen (Ab-Ag) interface we used Interface Interacting Residue (I2R), a selection method based on computed molecular interactions. The aggregation of all the molecular interactions between epitope and paratope residues allowed us to transform the 3D Ab-Ag complex structures into interface graphs. Based on these data and the probability of molecular interaction we developed EPI-Peptide Designer tool that uses predicted paratope residues for an epitope of interest to generate targeted peptide ligand libraries. EPI-Peptide Designer successfully predicted 301 peptides able to bind to LiD1 target protein (65% of the experimentally tested peptides), an enrichment of 22% compared to randomly generated peptides. This tool should enable the development of a new generation of synthetic interacting peptides that could be very useful in the biosensor, diagnostic and therapeutic fields. AVAILABILITY AND IMPLEMENTATION: All software developed in this work are available at http://www.biocomp.icb.ufmg.br/biocomp/ CONTACT: [email protected] SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

The problem of improving an initial segmentation of medical data by making use of gray level, texture, and gradient information is addressed. The mathematical environment is that of Markov random fields and stochastic processes. This yields two major advantages: automatic selection of program parameters and ergonomic software that can be used to test homogeneity properties of regions. The method is applied to echocardiographic images in order to segment cardiac cavities.>

Presents a Markov random field model designed to construct a segmentation of echocardiographic images from an initial segmentation. An iterative procedure for estimating the model parameters is described and results are presented for a sequence of cardiac images in order to segment cardiac cavities.>

The weight distributions of an(87,29)and a(58,29)circulant code are enumerated. The circulants are based on the quadratic residues and the quadratic nonresidues modulo the prime29. The(87,29)code is known to be cyclic while the(58,29)code is self-dual.