Transformations of Logic Programs on Infinite Lists

We consider an extension of logic programs, called \omega-programs, that can be used to define predicates over infinite lists. \omega-programs allow us to specify properties of the infinite behavior of reactive systems and, in general, properties of infinite sequences of events. The semantics of \omega-programs is an extension of the perfect model semantics. We present variants of the familiar unfold/fold rules which can be used for transforming \omega-programs. We show that these new rules are correct, that is, their application preserves the perfect model semantics. Then we outline a general methodology based on program transformation for verifying properties of \omega-programs. We demonstrate the power of our transformation-based verification methodology by proving some properties of Buechi automata and \omega-regular languages.Comment: 37 pages, including the appendix with proofs. This is an extended version of a paper published in Theory and Practice of Logic Programming, see belo

A Bayesian Networks Approach to Operational Risk

A system for Operational Risk management based on the computational paradigm of Bayesian Networks is presented. The algorithm allows the construction of a Bayesian Network targeted for each bank using only internal loss data, and takes into account in a simple and realistic way the correlations among different processes of the bank. The internal losses are averaged over a variable time horizon, so that the correlations at different times are removed, while the correlations at the same time are kept: the averaged losses are thus suitable to perform the learning of the network topology and parameters. The algorithm has been validated on synthetic time series. It should be stressed that the practical implementation of the proposed algorithm has a small impact on the organizational structure of a bank and requires an investment in human resources limited to the computational area

Independent Configurable Architecture for Reliable Operation of Unmanned Systems with Distributed Onboard Services

This paper presents the development of ICAROUS-2 (Independent Configurable Architecture for Reliable Operation of Unmanned Systems with Distributed Onboard Services), the second generation of a software architecture that integrates several algorithms as distributed onboard services to enable robust autonomous UAS applications. In particular, the ICAROUS architecture defines a framework to perform detect and avoid, geofencing, path monitoring, path planning, and autonomous decision making to ensure safety and mission progress. Most of the core algorithms implemented in ICAROUS are formally verified using an interactive theorem prover. These algorithms are composed together using a plan execution engine, whose operational semantics is formally specified. A description of the integrated architecture, services currently available, and flight test results highlighting the capability of ICAROUS are presented

A coupled thermal-analytical and mechanical approach to investigate the behavior of bonded anchors cured at sub-zero temperatures

In post-installed connection in reinforced concrete structures, bonded anchors are commonly adopted when elevated mechanical performances are required. Such performances may be significantly impaired by adverse service conditions, above all temperature variations with respect to room ambient one. It is also generally acknowledged that the curing temperature may impact on the anchor performances, to the extent that all the main existing qualification procedures assess the anchor behavior when cured at different temperatures, in particular below zero Celsius degree. However, among the few investigations focusing on the impact of a low curing temperature on the long term behavior of an anchor, a low effort exists in addressing the relationship between the anchor mechanical behavior and the thermal properties of the bonding agent. The paper proposes a coupled thermal-analytical and mechanical approach to detect potential critical issues in the long term mechanical behavior of the anchor as a function of the adhesive behavior, as investigated by thermal or thermo-mechanical analyses. To the scope, a wide investigation on two adhesives is carried out comprising MDSC, DMA, pull-out and sustained load tests. On the basis of the obtained results, it is concluded that some thresholds in the variations of degree of conversion and phase transition temperatures may indicate a negligible impact of a low curing temperature on the anchor mechanical behavior, but also that existing qualification procedures are not able to capture the anchor behavior, when cured at low temperatures and subjected, during its service life, to temperatures higher than room ambient one

TYPE AND COUNTER-TYPE FROM SPECIFIC CHROMOSOMAL REGIONS

Several studies have shown the importance of segmental deletions/duplications in the field of chromosome pathologies. Non allelic homologous recombination, NAHR, between chromosomes or sister chromatids, mediated by segmental duplications, is the foundation of frequent mechanisms for structural chromosome mutations such as micro-deletions, micro-duplications, translocations, inversions, and marker chromosomes. We analyzed three distinct genomic regions (22q11.2, 17p11.2, 16p11.2) and we discussed how the same chromosome region can be affected by deletion or by reciprocal duplication, respectively responsible for a syndrome or for a reciprocal counter-syndrome, with different phenotypic manifestation

The ghrelin paradox in the control of equine chondrocyte function: The good and the bad

Increasing evidence suggests a role for ghrelin in the control of articular inflammatory diseases like osteoarthritis (OA). In the present study we examined the ability of ghrelin to counteract LPS-induced necrosis and apoptosis of chondrocytes and the involvement of GH secretagogue receptor (GHS-R)1a in the protective action of ghrelin. The effects of ghrelin (10-7-10-11\u202fmol/L) on equine primary cultured chondrocytes viability and necrosis in basal conditions and under LPS treatment (100\u202fng/ml) were detected by using both acridine orange/propidium iodide staining and annexin-5/propidium iodide staining. The presence of GHS-R1a on chondrocytes was detected by Western Blot. The involvement of the GHS-R1a in the ghrelin effect against LPS-induced cytotoxicity was examined by pretreating chondrocytes with D-Lys3-GHRP-6, a specific GHS-R1a antagonist, and by using des-acyl ghrelin (DAG, 10-7and 10-9\u202fmol/L) which did not recognize the GHS-R 1a. Low ghrelin concentrations reduced chondrocyte viability whereas 10-7\u202fmol/L ghrelin protects against LPS-induced cellular damage. The protective effect of ghrelin depends on the interaction with the GHS-R1a since it is significantly reduced by D-Lys3-GHRP-6. The negative action of ghrelin involves caspase activation and could be due to an interaction with a GHS-R type different from the GHS-R1a recognized by both low ghrelin concentrations and DAG. DAG, in fact, induces a dose-dependent decrease in chondrocyte viability and exacerbates LPS-induced damage. These data indicate that ghrelin protects chondrocytes against LPS-induced damage via interaction with GHS-R1a and suggest the potential utility of local GHS-R1a agonist administration to treat articular inflammatory diseases such as OA

COPY NUMBER VARIATIONS IN THE ETIOLOGY OF EPILEPSY

Epilepsy is one of the most common neurological disorders in humans with a prevalence of 1% and a lifetime incidence of 3%. Idiopathic epilepsies occur in the absence of identifiable causal factors, but recent evidences show the role of genetic factors in the developing of these disorders. In particular, several studies focused their attention on the role of copy number variations (CNVs) in the etiology of epilepsy. In recent years, many CNVs have been identified, like 15q11.2, 15q13.3 and 16p13.11 microdeletions, 22q11.2 microduplication and many others. Possible candidate genes included in these regions were also studied and they seem to be involved in neuronal transmission and ion transport. The possibility to identify new rare CNVs allow a greater understanding of the mechanisms of epilepsy and other neurodevelopmental disorders