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Metadata vocabularies provide various semantic relations between concepts. For content-based recommender systems, these relations enable a wide range of concepts to be recommended. However, not all semantically related concepts are interesting for end users. In this paper, we identified a number of semantic relations, which are within one vocabulary (e.g. a concept has a broader/narrower concept) and across multiple vocabularies (e.g. an artist is associated to an art style). Our goal is to investigate which semantic relations are useful for recommendations of art concepts and to look at the combined use of artwork features and semantic relations in sequence. These sequences of ratings allow us to derive some navigation patterns from users, which might enhance the accuracy of recommendations and be reused for other recommender systems in similar domains. We tested the CHIP demonstrator, called the Art Recommender with end users by recommending both semanticallyrelated concepts and artworks features (e.g.creator, material, subject).

Bridging the gap between low-level features and semantics is a problem commonly acknowledged in the Multimedia community. Event modeling can fill the gap. In this paper we present the Simple Event Model (SEM) and its application in a Maritime Safety and Security use case about Situational Awareness. We show how we abstract over low-level features, recognize simple behavior events using a Piecewise Linear Segmentation algorithm, and model the events as instances of SEM. We apply deduction rules, spatial proximity reasoning, and semantic web reasoning in SWI-Prolog to derive abstract events from the recognized simple events. The use case described in this paper come from the Dutch Poseidon project.

Current state-of-the-art ontology-alignment evaluation methods are based on the assumption that alignment relations come in two flavors: correct and incorrect. Some alignment systems find more correct mappings than others and hence, by this assumption, they perform better. In practical applications however, it does not only matter how many correct mappings you find, but also which correct mappings you find. This means that, apart from correctness, relevance should also be included in the evaluation procedure. In this paper we expand the sample-based evaluation of the OAEI 2007 food task with a sample evaluation that uses relevance to prototypical search tasks as a selection criterion for the drawing of sample mappings.

Despite the success of the Web Ontology Language OWL, the development of expressive means for querying OWL knowledge bases is still an open issue. In this paper, we investigate how a very natural and desirable form of queries-namely conjunctive ones-can be used in conjunction with OWL such that one of the major design criteria of the latter-namely decidability-can be retained. More precisely, we show that querying the tractable fragment of OWL 1.1 is decidable. We also provide a complexity analysis and show that querying unrestricted is undecidable. © 2008 Springer-Verlag Berlin Heidelberg.

International audience; All type I IFNs act through a single cell surface receptor composed of the IFNAR1 and IFNAR2 subunits and two associated cytoplasmic tyrosine kinases of the Janus family, Tyk2 and Jak1. A central issue in type I IFN biology is to understand how a multitude of subtypes can generate similar signaling outputs but also govern specific cellular responses. This review summarizes results from the last decade that contributed to our current state of knowledge of IFN-receptor complex structure and assembly.

OBO is an ontology language that has often been used for modeling ontologies in the life sciences. Its definition is relatively informal, so, in this paper, we provide a clear specification for OBO syntax and semantics via a mapping to OWL. This mapping also allows us to apply existing Semantic Web tools and techniques to OBO. We show that Semantic Web reasoners can be used to efficiently reason with OBO ontologies. Furthermore, we show that grounding the OBO language in formal semantics is useful for the ontology development process: using an OWL reasoner, we detected a likely modeling error in one OBO ontology. © 2008 Springer-Verlag Berlin Heidelberg.

Summary Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is a selenoprotein belonging to the family of glutathione peroxidases. PHGPx has long been considered a major antioxidant that, in cooperation with vitamin E, protects biomembranes. To determine the expression pattern of PHGPx mRNA in human, quantitative RT-polymerase chain reaction (PCR) analyses using RNA from different embryonal and adult tissues were performed. A predominant expression was found in testes. In spermatozoa, PHGPx was found to be localized in the mid-piece of spermatozoa. We studied the relationship between spermatozoa PHGPx expression, mutations in PHGPx gene and human oligoasthenozoospermia, a defect in which both the number and the motility of spermatozoa are significantly below normal. Spermatozoa specimens from 45 infertile males were analysed for fertility-related parameters according to World Health Organisation and were classified as suffering from oligoasthenozoospermia. Two patients (4.44%) showed no expression of PHGPx and in nine patients (20.00%), a reduced expression of the enzyme was observed. DNA sequences of various regions of the PHGPx gene (coding, 5′flanking region and intron 1) from these patients and 58 fertile volunteers were analysed for mutations by PCR amplification and direct sequencing. Sequence data revealed no cause/effect relationship for any of the variants. From these data it can be concluded that oligoasthenozoospermia is associated with a decrease in the level of expression of PHGPx in the spermatozoa of some infertile men (24.44%), but is not linked to mutations in PHGPx gene.

Adult cutaneous Langerhans cell histiocytosis (LCH) is a rare disease. We report two cases illustrating the variability of the clinical presentation andthe response to treatment. In both cases a remission was achieved: in one case a partial remission with psoralen plus UVA irradiation (PUVA) and methotrexate plus topical corticosteroid ointment; in the other case by treatment with thalidomide. Despite a therapeutic response, both patients later developed haematological malignancies: a chronic myelo-monocytic leukaemia and an acute lymphatic leukaemia. In conclusion, patients with adultcutaneous LCH should be monitored carefully so that a secondary malignancy is not overlooked.

We discuss access to e-documents from three different perspectives beyond the plain keyword web-search of the entire document. The first one is the situation-depending delivery of multimedia documents adapting the preferred form (picture, text, speech) to the available information capacity or need exemplified by documents from the annotated media database of the Rijksmuseum. It goes beyond Quality of Service methods which insist on delivering information in the same form even if that is no longer effective. Secondly, we discuss the use of ontologies to provide access across diverse library categorizations as part of the W3C semantic web. The system translates codes in the one catalogue system into a set of codes in another expanding the potential access to digital heritage knowledge across all library systems in the ontology, such as AAT, Worldnet and IconClass. Thirdly, we discuss access to the pictorial contents of paintings by computer vision techniques, here showing in examples of Pieter de Hoogh and Johannes Vermeer which one of the two consistently painting photometric realistic in addition to adhering to the geometric realism as they both did. It is concluded access is the key issue in digital cultural heritage - be it access by situational delivery of e-document of cultural heritage, be it access to diverse knowledge systems, or be it access to the pictorial content of the picture

We introduce a Believes, Desires and Plans (BDP) agent that acts in a virtual environment using multi-modal interaction with the user. The environment is our virtual theatre environment. In this environment different agents have been introduced. In order to obtain a more uniform framework for agent interaction and a more uniform agent architecture we introduced a BDP agent for interactions between visitors and domain agents that inhabit this environment. We demonstrate how such an agent can play the role of a librarian in a virtual library.

In this paper we show that reinforcement learning can be used for minutiae detection in fingerprint matching. Minutiae are characteristic features of fingerprints that determine their uniqueness. Classical approaches use a series of image processing steps for this task, but lack robustness because they are highly sensitive to noise and image quality. We propose a more robust approach, in which an autonomous agent walks around in the fingerprint and learns how to follow ridges in the fingerprint and how to recognize minutiae. The agent is situated in the environment, the fingerprint, and uses reinforcement learning to obtain an optimal policy. Multi-layer perceptrons are used for overcoming the difficulties of the large state space. By choosing the right reward structure and learning environment, the agent is able to learn the task. One of the main difficulties is that the goal states are not easily specified, for they are part of the learning task as well. That is, the recognition of minutiae has to be learned in addition to learning how to walk over the ridges in the fingerprint. Results of successful first experiments are presented.