Shortening QBF Proofs with Dependency Schemes

We provide the first proof complexity results for QBF dependency calculi. By showing that the reflexive resolution path dependency scheme admits exponentially shorter Q-resolution proofs on a known family of instances, we answer a question first posed by Slivovsky and Szeider in 2014 [30]. Further, we conceive a method of QBF solving in which dependency recomputation is utilised as a form of inprocessing. Formalising this notion, we introduce a new calculus in which a dependency scheme is applied dynamically. We demonstrate the further potential of this approach beyond that of the existing static system with an exponential separation

DepQBF 6.0: A Search-Based QBF Solver Beyond Traditional QCDCL

We present the latest major release version 6.0 of the quantified Boolean formula (QBF) solver DepQBF, which is based on QCDCL. QCDCL is an extension of the conflict-driven clause learning (CDCL) paradigm implemented in state of the art propositional satisfiability (SAT) solvers. The Q-resolution calculus (QRES) is a QBF proof system which underlies QCDCL. QCDCL solvers can produce QRES proofs of QBFs in prenex conjunctive normal form (PCNF) as a byproduct of the solving process. In contrast to traditional QCDCL based on QRES, DepQBF 6.0 implements a variant of QCDCL which is based on a generalization of QRES. This generalization is due to a set of additional axioms and leaves the original Q-resolution rules unchanged. The generalization of QRES enables QCDCL to potentially produce exponentially shorter proofs than the traditional variant. We present an overview of the features implemented in DepQBF and report on experimental results which demonstrate the effectiveness of generalized QRES in QCDCL.Comment: 12 pages + appendix; to appear in the proceedings of CADE-26, LNCS, Springer, 201

Genomics and proteomics approaches to the study of cancer-stroma interactions

<p>Abstract</p> <p>Background</p> <p>The development and progression of cancer depend on its genetic characteristics as well as on the interactions with its microenvironment. Understanding these interactions may contribute to diagnostic and prognostic evaluations and to the development of new cancer therapies. Aiming to investigate potential mechanisms by which the tumor microenvironment might contribute to a cancer phenotype, we evaluated soluble paracrine factors produced by stromal and neoplastic cells which may influence proliferation and gene and protein expression.</p> <p>Methods</p> <p>The study was carried out on the epithelial cancer cell line (Hep-2) and fibroblasts isolated from a primary oral cancer. We combined a conditioned-medium technique with subtraction hybridization approach, quantitative PCR and proteomics, in order to evaluate gene and protein expression influenced by soluble paracrine factors produced by stromal and neoplastic cells.</p> <p>Results</p> <p>We observed that conditioned medium from fibroblast cultures (FCM) inhibited proliferation and induced apoptosis in Hep-2 cells. In neoplastic cells, 41 genes and 5 proteins exhibited changes in expression levels in response to FCM and, in fibroblasts, 17 genes and 2 proteins showed down-regulation in response to conditioned medium from Hep-2 cells (HCM). Nine genes were selected and the expression results of 6 down-regulated genes (<it>ARID4A</it>, <it>CALR</it>, <it>GNB2L1</it>, <it>RNF10</it>, <it>SQSTM1</it>, <it>USP9X</it>) were validated by real time PCR.</p> <p>Conclusions</p> <p>A significant and common denominator in the results was the potential induction of signaling changes associated with immune or inflammatory response in the absence of a specific protein.</p

Radiolabelled peptides for oncological diagnosis

Radiolabelled receptor-binding peptides targeting receptors (over)expressed on tumour cells are widely under investigation for tumour diagnosis and therapy. The concept of using radiolabelled receptor-binding peptides to target receptor-expressing tissues in vivo has stimulated a large body of research in nuclear medicine. The 111In-labelled somatostatin analogue octreotide (OctreoScan™) is the most successful radiopeptide for tumour imaging, and was the first to be approved for diagnostic use. Based on the success of these studies, other receptor-targeting peptides such as cholecystokinin/gastrin analogues, glucagon-like peptide-1, bombesin (BN), chemokine receptor CXCR4 targeting peptides, and RGD peptides are currently under development or undergoing clinical trials. In this review, we discuss some of these peptides and their analogues, with regard to their potential for radionuclide imaging of tumours

The effect of a novel crystallised bioactive glass-ceramic powder on dentine hypersensitivity: a long-term clinical study

P>The aim of this comparative clinical study was to evaluate a novel bioactive glass-ceramic (Biosilicate (R) 1-20 mu m particles) to treat dentine hypersensitivity (DH). Volunteers (n = 120 patients/ 230 teeth) received the following treatments: G1-Sensodyne (R), G2-SensiKill (R), G3-Biosilicate (R) incorporated in a 1% water-free-gel and G4-Biosilicate (R) mixed with distilled water at 1:10 ratio. G1 and G3 were applied at home, daily for 30 days; G2 and G4 were applied once a week by a dentist (four applications). A visual analogue scale (VAS) was employed to evaluate pain for each quadrant in one sensitive tooth at baseline, weekly during treatment and during a 6-month follow-up period. Dentine hypersensitivity values (G1/n = 52), (G2/n = 62), (G3/n = 59) and (G4/n = 59) were analysed with Kruskal-Wallis/Dunn tests. All the products were efficient in reducing DH after 4 weeks. Among the four materials tested, G4 demonstrated the best clinical performance and provided the fastest treatment to reduce DH pain. Distilled water proved to be an adequate vehicle to disperse Biosilicate (R). Low DH scores were maintained during the 6-month follow-up period. The hypothesis that the novel bioactive glass-ceramic may be an efficient treatment for DH was confirmed.FAPESP, State of Sao Paulo Research Foundation[04/05133-0]FAPESP, State of Sao Paulo Research Foundation[07/08179-9]CNPq, National Council for Scientific and Technological Development[0400604/2004-3]Cape