1,065 research outputs found

    SPARQL Query Recommendations by Example

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    In this demo paper, a SPARQL Query Recommendation Tool (called SQUIRE) based on query reformulation is presented. Based on three steps, Generalization, Specialization and Evaluation, SQUIRE implements the logic of reformulating a SPARQL query that is satisfiable w.r.t a source RDF dataset, into others that are satisfiable w.r.t a target RDF dataset. In contrast with existing approaches, SQUIRE aims at rec- ommending queries whose reformulations: i) reflect as much as possible the same intended meaning, structure, type of results and result size as the original query and ii) do not require to have a mapping between the two datasets. Based on a set of criteria to measure the similarity between the initial query and the recommended ones, SQUIRE demonstrates the feasibility of the underlying query reformulation process, ranks appropriately the recommended queries, and offers a valuable support for query recommendations over an unknown and unmapped target RDF dataset, not only assisting the user in learning the data model and content of an RDF dataset, but also supporting its use without requiring the user to have intrinsic knowledge of the data

    Psoriatic arthritis: genetics and pathogenesis

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    Psoriatic arthritis is a complex disease affecting primarily peripheral and axial joints and entheses together with the skin. The pathogenesis is characterized by a genetic background and by inflammatory mechanisms which may be triggered by environmental factors. Several susceptibility genes have been investigated; they include HLA genes, genes within the HLA region and genes outside the HLA region. T cells, including the recently described subset Th17, are thought to play an important role in the acute and chronic phases of the disease. Some of these findings allowed novel therapeutic interventions or opened new promising approaches in treatment. The most relevant data of the literature are summarized and discussed

    Failure to achieve lupus low disease activity state (LLDAS) six months after diagnosis is associated with early damage accrual in Caucasian patients with systemic lupus erythematosus

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    Background: The aim was to assess the attainability and outcome of the lupus low disease activity state (LLDAS) in the early stages of systemic lupus erythematosus (SLE). Methods: LLDAS prevalence was evaluated at 6 (T1) and 18 (T2) months after diagnosis and treatment initiation (T0) in a monocentric cohort of 107 (median disease duration 9.7 months) prospectively followed Caucasian patients with SLE. Reasons for failure to achieve LLDAS were also investigated. Multivariate models were built to identify factors associated with lack of LLDAS achievement and to investigate the relationship between LLDAS and Systemic Lupus International Collaboration Clinics (SLICC)/Damage Index (SDI) accrual. Results: There were 47 (43.9%) patients in LLDAS at T1 and 48 (44.9%) at T2. The most frequent unmet LLDAS criterion was prednisolone dose >7.5 mg/day (83% of patients with no LLDAS at T1). Disease manifestations with the lowest remission rate during follow up were increased anti-double-stranded DNA (persistently present in 85.7% and 67.5% of cases at T1 and T2, respectively), low serum complement fractions (73.2% and 66.3%) and renal abnormalities (46.4% and 28.6%). Renal involvement at T0 was significantly associated with failure to achieve LLDAS both at T1 (OR 7.8, 95% CI 1.4-43.4; p = 0.019) and T2 (OR 3.9, 95% CI 1.4-10.6; p = 0.008). Presence of any organ damage (SDI â\u89¥1) at T2 was significantly associated with lack of LLDAS at T1 (OR 5.0, 95% CI 1.5-16.6; p = 0.009) and older age at diagnosis (OR 1.05 per year, 95% CI 1.01-1.09; p = 0.020). Conclusion: LLDAS is a promising treatment target in the early stages of SLE, being attainable and negatively associated with damage accrual, but it fit poorly to patients with renal involvement

    Addressing exploitability of Smart City data

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    Central to a number of emerging Smart Cities are online platforms for data sharing and reuse: Data Hubs and Data Catalogues. These systems support the use of data by developers through enabling data discoverability and access. As such, the effectiveness of a Data Catalogue can be seen as the way in which it supports `data exploitability': the ability to assess whether the provided data is appropriate to the given task. Beyond technical compatibility, this also regards validating the policies attached to data. Here, we present a methodology to enable Smart City Data Hubs to better address exploitability by considering the way policies propagate across the data flows applied in the system

    Profit Shifting Frictions and the Geography of Multinational Activity

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    We develop a quantitative general equilibrium model of multinational activity embedding corporate taxation and profit shifting. In addition to trade and investment frictions, our model shows that profit-shifting frictions shape the geography of multinational production. Key to our model is the distinction between the corporate tax elasticity of real activity and profit shifting. The quantification of our model requires estimates of shifted profits flows. We provide a new, model-consistent methodology to calibrate bilateral profit-shifting frictions based on accounting identities. We simulate various tax reforms aimed at curbing tax-dodging practices of multinationals and their impact on a range of outcomes, including tax revenues and production. Our results show that the effects of the international relocation of firms across countries are of comparable magnitude as the direct gains in taxable income

    The Open University Linked Data - data.open.ac.uk

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    The article reports on the evolution of data.open.ac.uk, the Linked Open Data platform of the Open University, from a research experiment to a data hub for the open content of the University. Entirely based on Semantic Web technologies (RDF and the Linked Data principles), data.open.ac.uk is used to curate, publish and access data about academic degree qualifications, courses, scholarly publications and open educational resources of the University. It exposes a SPARQL endpoint and several other services to support developers, including queries stored server-side and entity lookup using known identifers such as course codes and YouTube video IDs. The platform is now a key information service at the Open University, with several core systems and websites exploiting linked data through data.open.ac.uk. Through these applications, data.open.ac.uk is now fulfilling a key role in the overall data infrastructure of the university, and in establishing connections with other educational institutions and information providers

    Supervised learning of soliton X-junctions in lithium niobate films on insulator

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    In this Letter, the first implementation, to our knowledge, of X-junctions between photorefractive soliton waveguides in lithium niobate-on-insulator (LNOI) films is reported. The experiments were performed on 8 μm thick films of congru- ent undoped LiNbO3. Compared with bulk crystals, the use of films reduces the soliton formation time, allows more con- trol over the interaction between the injected soliton beams, and opens a route to integration with silicon optoelectronics functions. The created X-junction structures show effective supervised learning, directing the signals propagated inside the soliton waveguides into the output channels highlighted by the control assigned by the external supervisor. Thus, the obtained X-junctions have behaviors analogous to biological neurons

    Large deviations for random walks on Gromov-hyperbolic spaces

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    Let Γ\Gamma be a countable group acting on a geodesic Gromov-hyperbolic metric space XX and μ\mu a probability measure on Γ\Gamma whose support generates a non-elementary subsemigroup. Under the assumption that μ\mu has a finite exponential moment, we establish large deviations results for the distance and the translation length of a random walk with driving measure μ\mu. From our results, we deduce a special case of a conjecture regarding large deviations of spectral radii of random matrix products.Comment: V1 --> V2: Modifications and small corrections after the referee reports, to appear in Ann. Sci. Ec. Norm. Super. (50 pages
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