On the complexity of semantic self-minimization

Partial Kripke structures model only parts of a state space and so enable aggressive abstraction of systems prior to verifying them with respect to a formula of temporal logic. This partiality of models means that verifications may reply with true (all refinements satisfy the formula under check), false (no refinement satisfies the formula under check) or dont know. Generalized model checking is the most precise verification for such models (all dont know answers imply that some refinements satisfy the formula, some dont), but computationally expensive. A compositional model-checking algorithm for partial Kripke structures is efficient, sound (all answers true and false are truthful), but may lose precision by answering dont know instead of a factual true or false. Recent work has shown that such a loss of precision does not occur for this compositional algorithm for most practically relevant patterns of temporal logic formulas. Formulas that never lose precision in this manner are called semantically self-minimizing. In this paper we provide a systematic study of the complexity of deciding whether a formula of propositional logic, propositional modal logic or the propositional modal mu-calculus is semantically self-minimizing. © 2009 Elsevier B.V. All rights reserved

Efficient Patterns for Model Checking Partial State Spaces in CTL & LTL

Compositional model checks of partial Kripke structures are efficient but incomplete as they may fail to recognize that all implementations satisfy the checked property. But if a property holds for such checks, it will hold in all implementations. Such checks are therefore under-approximations. In this paper we determine for which popular specification patterns, documented at a communityled pattern repository, this under-approximation is precise in that the converse relationship holds as well for all model checks. We find that many such patterns are indeed precise. Those that arent lose precision because of a sole propositional atom in mixed polarity. Hence we can compute, with linear blowup only, a semantic minimization in the same temporal logic whose efficient check renders the precise result for the original imprecise pattern. Thus precision can be secured for all patterns at low cost. © 2006 Elsevier B.V. All rights reserved

The soil conditions of the oak stand in the south-west part of Belarus

In the soil and climatic conditions of the oak stands (Quercus robur L.) grown installed: features of the state land-ground-water conditions on the water phy sical properties and moisture capacity; the regu-larities of distribution and content of nutrients were revealed; the granulometric composition of soil were established and the group and factional composition of humus were determined. The studies found that in the Bi alowieza Forest oak-woods grow on sod-podzolic and brown forest sandy and sabulous soils underlain by moraine loam. Oak-woods in the floodplains of Pripyat grow on floodplain sod gley sabulous soils with content of physical clay in humus horizons up to 20%. Soil conditions of oaks by water-physical characteristics, moisture reserves and agrochemical indicators are better in floodplain forests, while by density and granulometric texture – in upland types of oak-woods

Silicon resonant microcantilevers for absolute pressure measurement

This work is focused on the developing of silicon resonant microcantilevers for the measurement of the absolute pressure. The microcantilevers have been fabricated with a two-mask bulk micromachining process. The variation in resonance response of microcantilevers was investigated as a function of pressure 10−1-105 Pa, both in terms of resonance frequency and quality factor. A theoretical description of the resonating microstructure is given according to different molecular and viscous regimes. Also a brief discussion on the different quality factors contributions is presented. Theoretical and experimental data show a very satisfying agreement. The microstructure behavior demonstrates a certain sensitivity over a six decade range and the potential evolution of an absolute pressure sensor working in the same rang

СОВРЕМЕННЫЕ МЕТОДЫ КОМПЬЮТЕРНОЙ ДИАГНОСТИКИ НАРУШЕНИЙ ОККЛЮЗИИ И ФУНКЦИИ ВИСОЧНО-НИЖНЕЧЕЛЮСТНОГО СУСТАВА

To date, the traditional methods of instrumental diagnosis of occlusion and TMJ - quite time consuming and difficult to perform.Requires a very high qualification of experts capable of conducting such a diagnosis. In this regard, the existing and evolving digital technologycan not only producevarious removable and nonremovableorthodonticand orthopedicdesign, but also allow for a precise and easier to perform, diagnoseocclusion of dentition with the biomechanicsof the temporomandibular joint and the aesthetics of the patient's face.Традиционные методы инструментальной диагностики нарушений окклюзии и дисфункции височно-нижнечелюстного суставадостаточно трудоемки и сложны для выполнения. Необходима очень высокая квалификация специалистов способных провести такую диагностику. В этой связи существующие и постоянно развивающиеся цифровые технологии позволяют не только создавать различные съемные и несъемные ортопедические и ортодонтические конструкции, но также провести высокоточное и более простое обследование окклюзии с учетом биомеханики височно-нижнечелюстного сустава и эстетики лица пациента

Genome-wide association study reveals genetic variants associated with HIV-1C infection in a Botswana study population

Although there have been many studies of gene variant association with different stages of HIV/AIDS progression in United States and European cohorts, few gene-association studies have assessed genic determinants in sub-Saharan African populations, which have the highest density of HIV infections worldwide. We carried out genome-wide association studies on 766 study participants at risk for HIV-1 subtype C (HIV-1C) infection in Botswana. Three gene associations (AP3B1, PTPRA, and NEO1) were shown to have significant association with HIV-1C acquisition. Each gene association was replicated within Botswana or in the United States–African American or United States–European American AIDS cohorts or in both. Each associated gene has a prior reported influence on HIV/AIDS pathogenesis. Thirteen previously discovered AIDS restriction genes were further replicated in the Botswana cohorts, extending our confidence in these prior AIDS restriction gene reports. This work presents an early step toward the identification of genetic variants associated with and affecting HIV acquisition or AIDS progression in the understudied HIV-1C afflicted Botswana population

On Refinements of Boolean and Parametric Modal Transition Systems

We consider the extensions of modal transition systems (MTS), namely Boolean MTS and parametric MTS and we investigate the refinement problems over both classes. Firstly, we reduce the problem of modal refinement over both classes to a problem solvable by a QBF solver and provide experimental results showing our technique scales well. Secondly, we extend the algorithm for thorough refinement of MTS providing better complexity then via reductions to previously studied problems. Finally, we investigate the relationship between modal and thorough refinement on the two classes and show how the thorough refinement can be approximated by the modal refinement

Conformational landscapes of DNA polymerase I and mutator derivatives establish fidelity checkpoints for nucleotide insertion

The fidelity of DNA polymerases depends on conformational changes that promote the rejection of incorrect nucleotides before phosphoryl transfer. Here, we combine single-molecule FRET with the use of DNA polymerase I and various fidelity mutants to highlight mechanisms by which active-site side chains influence the conformational transitions and free-energy landscape that underlie fidelity decisions in DNA synthesis. Ternary complexes of high fidelity derivatives with complementary dNTPs adopt mainly a fully closed conformation, whereas a conformation with a FRET value between those of open and closed is sparsely populated. This intermediate-FRET state, which we attribute to a partially closed conformation, is also predominant in ternary complexes with incorrect nucleotides and, strikingly, in most ternary complexes of low-fidelity derivatives for both correct and incorrect nucleotides. The mutator phenotype of the low-fidelity derivatives correlates well with reduced affinity for complementary dNTPs and highlights the partially closed conformation as a primary checkpoint for nucleotide selection