Qualitative and quantitative analysis of systems and synthetic biology constructs using P systems

YesComputational models are perceived as an attractive alternative to mathematical models (e.g., ordinary differential equations). These models incorporate a set of methods for specifying, modeling, testing, and simulating biological systems. In addition, they can be analyzed using algorithmic techniques (e.g., formal verification). This paper shows how formal verification is utilized in systems and synthetic biology through qualitative vs quantitative analysis. Here, we choose two well-known case studies: quorum sensing in P. aeruginosas and pulse generator. The paper reports verification analysis of two systems carried out using some model checking tools, integrated to the Infobiotics Workbench platform, where system models are based on stochastic P systems.EPSR

A genome screen in multiple sclerosis reveals susceptibility loci on chromosome 6p21 and 17q22

The population prevalence of multiple sclerosis is 0.1%; however, the risk of the disease in the siblings of affected individuals is very much higher at 3-5%. The importance of genetic factors in accounting for this increased risk is confirmed by the results of twin and adoption studies. Despite the evidence for a strong genetic effect, a weak major histocompatibility complex (MHC) association is the only consistently observed feature in the genetics of multiple sclerosis. Other candidates have been proposed, including genes encoding the immunoglobulin heavy chain, T cell receptor beta chain and APOC2, but none has yet been confirmed. Evidence for linkage and association to the myelin basic protein gene has been reported in a genetically isolated Finnish population, but it has not been possible to reproduce these results in other populations. We used a two-stage approach to search the human genome for the genes causing susceptibility to multiple sclerosis. Two principal regions of linkage are identified, chromosomes 17q22 and 6p21 (MHC). Our results are compatible with genetic models involving epistatic interaction between these and several additional genes

Estrutura populacional de Petrolisthes armatus (Gibbes) (Decapoda, Anomura, Porcellanidae) da Ilha do Farol, Matinhos, Paraná, Brasil Population structure of Petrolisthes armatus (Gibbes) (Decapoda, Anomura, Porcellanidae) from Farol Isle, Matinhos, Paraná, Brazil

<abstract language="eng">Population structure of the porcelain crab Petrolisthes armatus (Gibbes, 1850) from the rocky shore of the Farol isle (25º51'S, 48º32'W) was carried out in the following aspects: annual fluctuation of the density, distribution of the developmental stages and sexes over year round, size composition and recruiting period of juveniles into the population. Monthly collections were made in the three sites of the midlittoral, from November/89 to April/91, with the aid of a trap. The air temperature ranged from 13ºC to 28ºC, that of the surface water from 16ºC lo 29ºC and the salinity of the surface water from 06.7‰ to 31.5‰. A total of 5.585 individuals of Petrolisthes armatus was collected, among which, 116 were in the megalopa stage, 1,579 juveniles, 830 immature males, 729 immature females, 1,161 mature males, 744 mature females and 426 ovigerous females. The population density ranged from 15.3 to 305.0 ind.m-2, with a peak in January. This density is the highest among the porcelain crab populations known from the literature. The species has continuous reproduction, but, there were two main cohorts in the year: summer one that was longer and more abundant and the winter one that was shorter and the less numerous