162 research outputs found

    Computing Strong and Weak Permissions in Defeasible Logic

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    In this paper we propose an extension of Defeasible Logic to represent and compute three concepts of defeasible permission. In particular, we discuss different types of explicit permissive norms that work as exceptions to opposite obligations. Moreover, we show how strong permissions can be represented both with, and without introducing a new consequence relation for inferring conclusions from explicit permissive norms. Finally, we illustrate how a preference operator applicable to contrary-to-duty obligations can be combined with a new operator representing ordered sequences of strong permissions which derogate from prohibitions. The logical system is studied from a computational standpoint and is shown to have liner computational complexity

    Strategic Argumentation is NP-Complete

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    In this paper we study the complexity of strategic argumentation for dialogue games. A dialogue game is a 2-player game where the parties play arguments. We show how to model dialogue games in a skeptical, non-monotonic formalism, and we show that the problem of deciding what move (set of rules) to play at each turn is an NP-complete problem

    Changes to temporary norms

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    Normative systems accommodate temporary norms of several types, which can also be modified in different, and codified ways. In this paper we address the problem of modifying temporary norms that are represented by means of the combination of two known formalisms in the current literature. The framework evolves from a known one, which provides a system of norms at two distinct layers, and represents changes at the two layers as means to provide room for the codified change types. This results in four novel operators that anticipate and extend norms in two different combined ways, by preserving or not the effects of the norms in the period of time generated by the temporal modifications. We study these new oper- ators and show how they relate to the operators of annulment and abrogation analysed elsewhere

    Sequence Semantics for Norms and Obligations

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    This paper presents a new version of the sequence semantics presented at DEON 2014. This new version allows us for a capturing the distinction between logic of obligations and logic of norms. Several axiom schemata are discussed, while soundness and completeness results are proved

    Molecular analysis of the mating type (MAT1) locus in strains of the heterothallic ascomycete Botrytis cinerea

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    Botrytis cinerea shows a heterothallic bipolar mating‐type system; homothallism has been occasionally observed. MAT1 genes and flanking regions in the reference strains SAS56 (MAT1‐1) and SAS405 (MAT1‐2) and their monoascosporic progeny were analysed. The two mating types confirmed different sequences of 2513 bp (MAT1‐1) and 2776 bp (MAT1‐2), flanked by near identical regions. In all isolates, each idiomorph included two mating‐type specific genes: MAT1‐1‐1 (1161 bp), encoding an alpha‐domain containing protein, and MAT1‐1‐5 (1301 bp); or MAT1‐2‐1 (1236 bp), encoding a HMG‐domain protein, and MAT1‐2‐4 (712 bp); the latter genes encode putative proteins of unknown function. Truncated MAT1‐1‐1 (670 bp) and MAT1‐2‐1 (92 bp) sequences of the opposite mating‐type were found in the flanking regions. Idiomorph‐specific PCR primer pairs were used to explore the structure of the MAT1 locus in ascospore progeny and field isolates showing homothallic behaviour, and the locus organization in all of them did not differ from that of heterothallic strains. Constitutive expression of all the four mating‐type genes was ascertained by RT‐PCR at four different developmental stages (mycelium, sclerotia at two different stages and apothecia). Antisense transcription of the MAT1‐2‐1 gene with isoforms from alternative splicing was detected. Comparative analysis of MAT1 loci in B. cinerea and in the closely related homothallic Sclerotinia sclerotiorum led to the identification of short nearly identical sequences

    Dietary Supplementation of Oregano and Sage Dried Leaves on Performances and Meat Quality of Rabbits

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    Abstract The aim of this research was to evaluate the dietary supplementation 1% (w/w) of oregano and sage dried leaves on performances and meat quality of broiler rabbits. A feeding trial, which lasted 48 d, was carried out on 105 male Bianca Italiana rabbits randomly divided in seven groups and fed ad libitum. At the end of the trial ten animals per group were slaughtered and samples of dorsal muscle were taken in order to perform laboratory analysis. Mortality rate did not statistically differ between groups. Growth performances of animals fed diets supplemented with aromatic plants were higher (

    First Report of Pseudomonas Grapevine Bunch Rot Caused by Pseudomonas syringae pv. syringae .

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    Pseudomonas syringae pv. syringae, a Gammaproteobacterium belonging to genomospecies 2 within the P. syringae complex, is distributed worldwide, and it is responsible for bacterial canker on >100 different hosts, including the grapevine. P. syringae pv. syringae induces necrotic lesions in the leaf blades, veins, petioles, shoots, rachis, and tendrils on grapevine cultivars in different areas. P. syringae pv. syringae has been associated with severe economic losses in different grape cultivars in Australia, where it causes inflorescence rot. In midsummer to late summer 2017, symptoms of berry rots differing from those caused by the common berry rots agents were observed in different cultivar Red Globe vineyards of Apulia (southern Italy). As proven by fulfillment of Koch's postulates, these symptoms were caused by a bacterium that, according to the results of biochemical, physiological, nutritional, antimicrobial activity, and pathogenicity tests and sequencing of 16S ribosomal DNA, gyrB, rpoB, and rpoD genes, was identified as P. syringae pv. syringae. This is the first report of Pseudomonas grapevine bunch rot

    Does Systematic Preliminar Colour Doppler Study Reduce Kidney Biopsy Complication Incidence?

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    While ultrasonography is widely performed prior to biopsy, colour Doppler examination is often used only to discover post-biopsy complications. Aim of this paper was to evaluate the usefulness of colour Doppler examination in planning the optimal site of puncture for renal biopsy. Present analysis includes 561 consecutive percutaneous renal biopsies performed from the same operator. Until August 2000 332 biopsies were performed after a preliminary ultrasonography (Group A). From September 2000, 229 patients underwent even a preliminary colour Doppler study (Group B). Postbioptic bleeding were categorized as minor (gross hematuria or subcapsular perinephric hematoma < 4 cmq of greater diameter) or major (hematoma >4 cmq of greater diameter; requiring blood transfusion or invasive procedures; leading to acute renal failure, urine tract obstruction, septicaemia, or death). Major complications were seen in 2.1% in Group A while in Group B only one case was reported (0.43%). Minor clinically significant complications occur in 7.8% in Group A and in 3.4% of cases of Group B. Colour Doppler reduced drastically the incidence of complications observed before the introduction of routine colour Doppler examination prior to biopsy. In our opinion, these data support the use of preliminary colour Doppler study when a biopsy is planned

    The characteristics of different diagnostic tests in adult mild asthmatic patients : comparison with patients with asthma-like symptoms by gastro-oesophageal reflux.

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    SummaryBackgroundDiagnosing asthma cannot be always easy. It is important to consider the validity of the diagnostic tests, and/or how much more commonly they are positive in patients with asthma compared to healthy subjects and, particularly, to patients with asthma-like symptoms.ObjectiveTo evaluate the validity of diagnostic tests for asthma, in terms of sensitivity, specificity, positive and negative predictive values, in patients with bronchial asthma compared to patients affected by gastro-oesophageal reflux disease (GERD) with asthma-like symptoms, and healthy control subjects without asthma and gastro-oesophageal reflux (GER).DesignSingle-center, cross-sectional, observational study.PatientsWe studied 60 patients with mild asthma, 30 patients with GERD and asthma-like symptoms and 25 healthy control subjects.MeasurementsWe measured provocative concentration of methacholine causing a 20% fall in the forced expiratory volume in 1s (MCh PC20/FEV1), the amplitude percent mean of peak expiratory flow (A%M of PEF), derived from twice-daily readings for >2 weeks, the FEV1/forced vital capacity (FEV1/FVC) ratio, the eosinophil count in blood and in induced sputum and the serum eosinophil cationic protein (ECP) levels.ResultsFEV1/FVC ratio, A%M of PEF, blood eosinophils counts and serum ECP levels were less sensitive and specific when the reference population was composed of patients with asthma-like symptoms by GER. While, MCh PC20/FEV1 and induced sputum eosinophils count were the most sensitive (both 90%) and specific (89% and 92%, respectively) tests.ConclusionOur findings demonstrate that MCh PC20/FEV1 and the induced sputum eosinophil count are the most useful objective tests in patients with mild asthma. All patients with asthma presented both an MCh PC20/FEV1 <1500μg and eosinophils count in the induced sputum >1%
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