Inference Rules in Nelson’s Logics, Admissibility and Weak Admissibility

© 2015, Springer Basel. Our paper aims to investigate inference rules for Nelson’s logics and to discuss possible ways to determine admissibility of inference rules in such logics. We will use the technique offered originally for intuitionistic logic and paraconsistent minimal Johannson’s logic. However, the adaptation is not an easy and evident task since Nelson’s logics do not enjoy replacement of equivalences rule. Therefore we consider and compare standard admissibility and weak admissibility. Our paper founds algorithms for recognizing weak admissibility and admissibility itself – for restricted cases, to show the problems arising in the course of study

RETROSPECTIVE ANALYSIS OF BIOLOGICAL AND MOLECULAR-GENETIC PROPERTIES OF STRAINS - CAUSATIVE AGENTS OF CHOLERA - ISOLATED IN UKRAINE IN 1994 - 2011

Aim. Retrospective analysis of biological and molecular-genetic properties of strains - causative agents of cholera - isolated in the period of epidemics in Ukraine in 1994 - 2011. Materials and methods. Phenotypic and molecular-genetic properties of 5 strains of cholera vibrios, biovar El Tor isolated from cholera patients and 4 strains from the environmental samples were studied using traditional bacteriological and genetic methods. Detection of DNA for toxigenicity genes and genes characteristic for El Tor and classic biovar were carried out by PCR method using reagent kits «AmpliSens- Vibrio cholerae FRT» and «.Vibrio cholerae ctxB-rstR-rstC genes, REF» (an experimental test system). Sequencing of genomes of 4 strains of causative agents of cholera was carried out in genetic analyzer Ion Torrent Personal Genome Machine. Results. Strains of cholera vibrios identified in Ukraine in 1994 and 2011 such as a typical toxigenic biovar El Tor (V cholerae 01, El Tor, Ogawa, Hly-, ctxA+, tcpA+) contain genes of the classic cholera vibrio in their genome and are genetically altered (hybrid) variants of cholera vibrio biovar El Tor producing enterotoxin CT1 and having increased virulence, that was clinically manifested in predominance of severe forms of cholera in Mariupol of Donetsk region in 2011. Genome sequences of the 4 studied strains were deposited into the international database DDBJ/EMBL/GenBank. Conclusion. The studied isolates were established to belong to a clade of strains associated with cholera outbreaks in Haiti and Asian continent, from where genetically altered strains of cholera vibrios biovar El Tor were introduced to Haiti in 2010, based on results of comparison of genomic sequences of the studied strains with genomes of V. cholera strains from the international database GenBank

Unification in modal logic

National audienceIn this talk, we will give a survey of the results on unification in modal logic and we will present some of the open problems whose solution will have a great impact on the future of the area. After an introductory part about unification in equational theories, we will consider the case of Boolean unification, we will study the unification problem in Intuitionistic Propositional Logic and transitive normal modal logics like K4, we will introduce the notions of projective and transparent unifiers and we will define filtering unification. Then, we will present the latest results obtained within the context of unification in description logics and in multimodal, tense and epistemic logics