544 research outputs found

    An unsupervised approach to disjointness learning based on terminological cluster trees

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    In the context of the Semantic Web regarded as a Web of Data, research efforts have been devoted to improving the quality of the ontologies that are used as vocabularies to enable complex services based on automated reasoning. From various surveys it emerges that many domains would require better ontologies that include non-negligible constraints for properly conveying the intended semantics. In this respect, disjointness axioms are representative of this general problem: these axioms are essential for making the negative knowledge about the domain of interest explicit yet they are often overlooked during the modeling process (thus affecting the efficacy of the reasoning services). To tackle this problem, automated methods for discovering these axioms can be used as a tool for supporting knowledge engineers in modeling new ontologies or evolving existing ones. The current solutions, either based on statistical correlations or relying on external corpora, often do not fully exploit the terminology. Stemming from this consideration, we have been investigating on alternative methods to elicit disjointness axioms from existing ontologies based on the induction of terminological cluster trees, which are logic trees in which each node stands for a cluster of individuals which emerges as a sub-concept. The growth of such trees relies on a divide-and-conquer procedure that assigns, for the cluster representing the root node, one of the concept descriptions generated via a refinement operator and selected according to a heuristic based on the minimization of the risk of overlap between the candidate sub-clusters (quantified in terms of the distance between two prototypical individuals). Preliminary works have showed some shortcomings that are tackled in this paper. To tackle the task of disjointness axioms discovery we have extended the terminological cluster tree induction framework with various contributions: 1) the adoption of different distance measures for clustering the individuals of a knowledge base; 2) the adoption of different heuristics for selecting the most promising concept descriptions; 3) a modified version of the refinement operator to prevent the introduction of inconsistency during the elicitation of the new axioms. A wide empirical evaluation showed the feasibility of the proposed extensions and the improvement with respect to alternative approaches

    Possible role of ABO system in age-related diseases and longevity: a narrative review

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    ABO blood group antigens are expressed either on the surface of red blood cells either on a variety of other cells. Based on the available knowledge of the genes involved in their biosynthesis and their tissue distribution, their polymorphism has been suggested to provide intraspecies diversity allowing to cope with diverse and rapidly evolving pathogens. Accordingly, the different prevalence of ABO group genotypes among the populations has been demonstrated to be driven by malaria selection. In the similar manner, a particular ABO blood group may contribute to favour life-extension via biological mechanisms important for surviving or eluding serious disease. In this review, we will suggest the possible association of ABO group with age-related diseases and longevity taking into account the biological role of the ABO glycosyltransferases on some inflammatory mediators as adhesion molecule

    Centenarians and diet: what they eat in the Western part of Sicily.

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    This paper pays attention to the modifiable lifestyle factors such as diet and nutrition that might influence life extension and successful ageing. Previous data reported that in Sicily, the biggest Mediterranean island, there are some places where there is a high frequency of male centenarians with respect to the Italian average. The present data show that in Sicani Mountain zone there are more centenarians with respect to the Italian average. In fact, in five villages of Sicani Mountains, there were 19 people with an age range of 100-107 years old from a total population of 18,328 inhabitants. So, the centenarian number was 4.32-fold higher than the national average (10.37 vs. 2.4/10,000); the female/male ratio was 1.1:1 in the study area, while the national ratio is 4.54:1. Unequivocally, their nutritional assessment showed a high adherence to the Mediterranean nutritional profile with low glycemic index food consumed. To reach successful ageing it is advisable to follow a diet with low quantity of saturated fat and high amount of fruits and vegetables rich in phytochemicals

    CNT Conductive Epoxy Composite Metamaterials: Design, Fabrication, and Characterization

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    17 USC 105 interim-entered record; under review.In this study, carbon nanotube (CNT) epoxy composite films were fabricated, characterized, and tested as resonant, plasmonic metamaterials. CNT–epoxy formulations, containing diverse CNT loadings, were fabricated and templates were used to generate repeating arrays of squares of diverse dimensions. Their absorption characteristics were characterized by collecting free space reflectivity data in the microwave band, using an arch setup in an anechoic chamber. Data were collected from 2 to 20 GHz. The materials behavior was modeled using a standard unit-cell-based finite element model, and the experimental and calculated data were compared. The experimental results were successfully reproduced with appropriate adjustments to relative permittivity of the composite films. This research demonstrates the ability to use CNT-based conductive composites for manufacturing metamaterials, offering a potentially lighter-weight alternative in place of traditional metal films. Lower conductivity than other conductors causes a widening of the absorption curves, providing a wider band of frequency absorption

    MASTER IN “GEOGRAPHY, GOVERNANCE AND ECONOMICS. INSTRUMENTS, METHODS AND GEOGRAPHIC INFORMATION SYSTEM FOR TERRITORIAL MANAGEMENT” OF UNIVERSITY OF VERONA. OVERVIEW, REFERENCE DOCUMENTS AND CARTOGRAPHIC PRACTICAL EXPERIENCE

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    Analisi del territorio, interpretazione della sua complessità, individuazione delle dinamiche di sviluppo (o di regressione) e formulazione di scenari funzionali alle scelte politiche territoriali rappresentano idee guida intorno alle quali si è strutturata l’iniziativa formativa cui si riferisce nel presente contributo. Si mostreranno in sintesi, inoltre, la “mappa” del cofinanziamento al servizio della formazione, gli obiettivi programmati, i protagonisti, i quadri strategici e le priorità di intervento sulla base dei quali si sono realizzate esperienze di stage nell’ambito della rappresentazione cartografica strettamente connessa ad un quadro di sviluppo relativo alle nuove tecnologie ICT applicate al territorio. Fondi strutturali, politiche di coesione, regolamenti CE, obiettivi connessi, in primis, la cooperazione territoriale e la competitività della Regione Veneto si intersecano ed esplicano attraverso la creazione di competenze rivolte alla gestione di territori complessi. All’interno di questi ultimi si innervano dinamiche strettamente legate alla nascita di sistemi locali e di innovativi approcci di governance per il governo del territorio.Territorial analysis, interpretation and identification of development paths, scenario-building exercises represent the concepts to which we referred when structuring the master degree henceforth presented. The paper is divided into two parts (reflecting the organization given to the course). In the first one - in order to facilitate the understanding of current trends - we describe the rational behind such a project and discuss its theoretical underpinnings [making explicit reference to the debate over local (economic) development)]. Emerging local and regional systems act progressively more as gateways through which (economic) knowledge is transferred and as key nodes of the worldwide network channelling economic efficiency and growth. Policies aimed at enhancing competitiveness gain more relevance, also because of the societal and territorial re-organization those processes imply. In order for the students to acquire the theoretical tools necessary to better understand territorial dynamics, part of the degree focuses on analysing participatory governance mechanisms currently implemented (baring in mind the role social relationships play as a structuring factor that triggers interactive learning and interconnects individuals and organizations). In the second part of the article, we offer an overview of the EU co-funding schemes aimed at improving human capital training. We give information on objectives, actors involved, national and regional strategic frameworks programmes and priorities, structural funds regulations and the cohesion policy. A final paragraph will be specifically dedicated to describe internship experiences. The latter have been designed, in fact, in such a way that students were asked to both work within the field of cartographic/territorial research and use the latest ICT tools available (the training for which was given in a specific module)

    Association between interleukin-10 polymorphisms and Alzheimer's disease: a systematic review and meta-analysis

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    It has been hypothesized that polymorphisms of interleukin (IL)-10 genes affect the risk of developing late onset Alzheimer's disease (AD). However, results of different studies are often inconsistent. Our aim was to investigate by meta-analysis the association of the common polymorphisms comprehensively defining the genetic variability of the IL-10 gene with AD risk. Fifteen studies investigating the association between IL-10 polymorphisms (-1082,-819,-592) and AD were found and analyzed. The model-free approach was applied to meta-analyze these case-control genetic association studies. Available data suggested an association between-1082 polymorphism and AD risk with a marginal statistical significance (GG versus AG/AA: pooled odds ratio [OR]: 0.82, 95% confidence interval CI: 0.65-1.02) and evidence of a moderate degree of between-study heterogeneity (χ 2 = 27.13, d.f. = 13, p = 0.01, I 2 = 52%). For the-819 and-592 polymorphisms, we did not find an association with AD, but significant between-study heterogeneity made genotype data pooling unacceptable. Analysis by IL-10 haplotype showed that the-1082G/-819C/-592C haplotype is associated with a lower risk of AD, although with a marginal statistical significance, probably due to the low number of studies included (GCC versus other genotypes: OR: 0.61, 95% CI: 0.32-1.15; I 2: 85%). Current findings suggest a possible association between-1082 A > G polymorphism and the risk of developing AD; this effect is more evident in the oldest patients. The high degree of between-study heterogeneity, due to several underpowered studies and to other methodological problems of individual studies underlies the need for further methodologically adequate studies. © 2012-IOS Press and the authors. All rights reserved

    Pathophysiology of vascular dementia

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    The concept of Vascular Dementia (VaD) has been recognized for over a century, but its definition and diagnostic criteria remain unclear

    Blood group does not appear to affect longevity a pilot study in centenarians from Western Sicily

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    Centenarians are the best example of extreme human longevity, and they represent a selected population in which the appearance of major age-related diseases, such as cancer, and cardiovascular diseases among others, has been consistently delayed or escaped. The study of the long-lived individual genetic profile has the purpose to possibly identify the genes and the allelic variations influencing extended life expectancy, hence considering them as biomarkers of age-related diseases onset and development. The present study shows no significant differences between allelic variations of ABO blood groups among a group of centenarians from Western Sicily

    The Ability to Look Beyond. The Treatment of Peripheral Arterial Disease

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    This paper offers a practical overview of the contemporary management of patients with peripheral arterial disease presenting intermittent claudication (IC), including clinical and instrumental diagnosis, risk factors modification, medical management, and evidence-based revascularization indications and techniques. Decision making represents a crucial element in the management of the patient with IC; for this, we think a review of this type could be very useful, especially for non-vascular specialists
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