David Carral

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Pancreatic pseudocysts can be managed conservatively in the majority of patients but some of them will require surgical, endoscopic or percutaneous drainage. Endoscopic drainage represents an efficient modality of drainage with a high resolution rate and lower morbidity and mortality than the surgical or percutaneous approach. In this article we review the(More)
BACKGROUND propofol is a hypnotic used with increasing frequency for sedation during endoscopic procedures. Most of the reports published related with its employment by non-anaesthesiologists, refers to basic endoscopy, with little reference to its use in advanced endoscopy. OBJECTIVE to evaluate the efficacy and safety of propofol sedation administered(More)
Trajectory data have been used in a variety of studies, including human behavior analysis, transportation management, and wildlife tracking. While each study area introduces a different perspective, they share the need to integrate positioning data with domain-specific information. Semantic annotations are necessary to improve discovery, reuse, and(More)
The OWL 2 profiles are fragments of the ontology language OWL 2 for which standard reasoning tasks are feasible in polynomial time. Many OWL ontologies, however, contain a typically small number of out-of-profile axioms, which may have little or no influence on reasoning outcomes. We investigate techniques for rewriting axioms into the EL and RL profiles of(More)
The concepts of scale is at the core of cartographic abstraction and mapping. It defines which geographic phenomena should be displayed, which type of geometry and map symbol to use, which measures can be taken, as well as the degree to which features need to be exaggerated or spatially displaced. In this work, we present an ontology design pattern for map(More)
Ontology design patterns ease the engineering of ontologies, improve their quality, foster reusability, and support the alignment of ontologies by acting as common building blocks or strategies for reoccurring modeling problems. This makes ontology design patterns key enablers of semantic interoperability and, hence, a crucial technology for representing(More)
We report on a recent advance in integrating Rules and OWL. We discuss a recent proposal, known as nominal schemas, which realizes a seamless integration of Datalog rules into the description logic SROIQ which underlies OWL 2 DL. We present extensions of the standardized OWL syntaxes to incorporate nominal schemas, reasoning algorithms, and a first naive(More)
Description Logics – the logics underpinning the Web Ontology Language OWL – and rules are currently the most prominent paradigms used for modeling knowledge for the Semantic Web. While both of these approaches are based on classical logic, the paradigms also differ significantly, so that naive combinations result in undesirable properties such as(More)
INTRODUCTION The benign or malignant nature of ampullary tumours has prognostic and therapeutic implications. On the other hand the difficulty of reaching a correct preoperative diagnosis in these lesions is well known, even when we have a histological study obtained by endoscopic biopsies. MATERIAL AND METHODS We review all ERCP's in which biopsies of(More)
Extending description logics with so-called nominal schemas has been shown to be a major step towards integrating description logics with rules paradigms. However, establishing efficient algorithms for reasoning with nominal schemas has so far been a challenge. In this paper, we present an algorithm to reason with the description logic fragment ELROVn, a(More)