Compressed k2-Triples for Full-In-Memory RDF Engines

Current "data deluge" has flooded the Web of Data with very large RDF datasets. They are hosted and queried through SPARQL endpoints which act as nodes of a semantic net built on the principles of the Linked Data project. Although this is a realistic philosophy for global data publishing, its query performance is diminished when the RDF engines (behind the endpoints) manage these huge datasets. Their indexes cannot be fully loaded in main memory, hence these systems need to perform slow disk accesses to solve SPARQL queries. This paper addresses this problem by a compact indexed RDF structure (called k2-triples) applying compact k2-tree structures to the well-known vertical-partitioning technique. It obtains an ultra-compressed representation of large RDF graphs and allows SPARQL queries to be full-in-memory performed without decompression. We show that k2-triples clearly outperforms state-of-the-art compressibility and traditional vertical-partitioning query resolution, remaining very competitive with multi-index solutions.Comment: In Proc. of AMCIS'201

On the relation between the IR continuum and the active galactic nucleus in Seyfert galaxies

A sample of the brightest known Seyfert galaxies from the CfA sample is analyzed on the basis of ISO photometric and spectroscopic data. Regardless of the Seyfert type, the mid-IR continuum emission from these galaxies is found to be correlated with the coronal line emission arising in the nuclear active region. Conversely, the correlation degrades progressively when moving from the mid- to the far-IR emission, where it ends to vanish. It is concluded that the mid-IR emission is largely dominated by dust heated by processes associated with the active nucleus whereas the far-IR is a different component most probably unrelated with the active region. We suggest that the far-IR component is due to dust heated by the stellar population in the disks of these galaxies.Comment: 6 pages, 3 figures To be published in Astronomy and Astrophysic

Identification of the 4-hydroxyphenylacetate transport gene of Escherichia coli W : construction of a highly sensitive cellular biosensor

AbstractThe mechanism of uptake of 4-hydroxyphenylacetate (4-HPA) by Escherichia coli W. was investigated. The 4-HPA uptake was induced by 4-HPA, 3-hydroxyphenylacetate (3-HPA) or phenylacetate (PA) and showed saturation kinetics with apparent Kt and Vmax values of 25 μM and 3 nmol/min per 109 cells, respectively. Transport of 4-HPA was resistant to N,N″-dimethylcarbodiimide (DCCD), but was completely inhibited by cyanide and 4-nitrophenol, and, to a lower extent, by arsenate and azide, suggesting that energy is required for the uptake process. Competition studies showed that 4-HPA uptake was inhibited by 3-HPA or 3,4-dihydroxyphenylacetate (3,4-DHPA) but not by 2-hydroxyphenylacetate (2-HPA), l-tyrosine or other structural analogues, indicating a narrow specificity of the transport system. We have demonstrated, using two experimental approaches, that the hpaX gene of the 4-HPA catabolic cluster, which encodes a protein of the superfamily of transmembrane facilitators, is responsible for 4-HPA transport. Aside from the aromatic amino acid transport systems, hpaX is the first transport gene for an aromatic compound of enteric bacteria that has been characterized. A highly sensitive cellular biosensor has been constructed by coupling the 4-HPA transport system to a regulatory circuit that controls the production of β-galactosidase. This biosensor has allowed us to demonstrate that the transport system performs efficiently at very low external concentrations of 4-HPA, similar to levels that would be expected to occur in natural environments

Generated emotions by various types of games in physical education

El objetivo del presente estudio ha sido ahondar en el conocimiento de las emociones generadas a través de la práctica de diversos tipos de juegos, mediante la puesta en práctica de una propuesta diseñada a tal efecto. Más concretamente se ha tratado de conocer en qué medida, los juegos cooperativos y de oposición permiten el desarrollo emocional del alumnado en comparación con los juegos populares cooperativos y de oposición. Los participantes han sido un total de 50 alumnos y alumnas de sexto curso de Educación Primaria. El instrumento empleado ha sido el cuestionario sobre las percepciones socioemocionales de Gil-Madrona y Martínez (2016). Los resultados indican una gran similitud entre la utilización de los juegos cooperativos y juegos populares cooperativos. No obstante, los juegos populares de oposición producen mayores emociones positivas en el alumnado respecto a los juegos de oposición. El porcentaje de alumnado que se decanta por las emociones plancenteras es manifiestamente superior al de aquellos que se decantan por las displacenteras. Finalmente, se concluye que la propuesta utilizada es eficaz para producir emociones en los cuatro dominios de acción motriz objeto de estudioThe aim of this research has been to know which are the generated emotions through the practice of diverse kinds of games, through a proposal. Specifically, it is have been tried to know how cooperative and opposition games allow for the emotional development of the students with respect to traditional cooperative games and traditional opposition games. A total of 50 children of 6th grade took part in this work. The instrument used was the Gil-Madrona and Martinez's questionnaire (2016) about socio-emotional perceptions. The results indicate a similarity between using cooperative and traditional cooperative games. However, traditional opposition games produce greater positive emotions in students with respect to opposition games. Finally, it is concluded that the approach used is effective to produce emotions in the four motor domains studie

On the relation between the coronal line emission and the IR/X-ray emission in Seyfert galaxies

The relation between the X-ray, the coronal line and the infrared (IR) emissions in a sample of the brightest known Seyfert galaxies is analysed. A close relationship between the absorption-corrected soft X-ray emission and both the mid-IR and the coronal line emission is found for the Seyfert type 2 objects in the sample. The coronal line and the X-ray emissions are both main tracers of the central activity, hence their relationship with the mid-IR emission points to nuclear energetic process as the main responsibles of the heating of the circumnuclear dust. On the other hand, the above relations do not seem to hold for the Seyfert type 1 discussed in the sample, at least when the comparisons are done in a flux diagram. This is partially because of the reduced number of objects of this type analysed in this work and the fact that the measured soft X-ray emission in Seyfert 1s is systematically larger, by at least an order of magnitude, than that in the Seyfert 2 counterparts. Finally, the hard X-ray emission in the studied sample appears unrelated to either the mid-IR or the coronal line emission.Comment: 14 pages, 3 figures To be published in MNRAS (accepted

Long- term effects of fire and three fire-fighting chemicals on a soil-plant system.

The impacts of fire and fire-fighting chemicals (FFC) on soil properties and the soil-plant system were evaluated five years after treatment application. Unburnt soils (US) were compared with burnt soils treated with water alone (BS) or with foaming agent (BS+Fo), Firesorb polymer (BS+Fi), or ammonium polyphosphate (BS+Ap). Soils (0-2 cm depth) and foliar material (Ulex micranthus, Pterospartum tridentatum, Erica umbellata and Pinus pinaster) were analysed for total-C, total-N, δ 15N, nutrients (soil-available; plant-total), pH and inorganic-N (soils) and vegetation cover and height. No long-term effects of FFC on soil properties were found except for pH (BS+Fo > BS+Ap), inorganic-N and P (BS+Ap > other treatments). BS+Ap plants usually showed higher values of δ 15N, N, P and Na, but less K. Soil coverage by Pterospartum and Ulex was higher in BS+Ap than in other treatments, while the opposite was observed for Erica; shrubs were always taller in BS+Ap. After 3 years of growth, the size of pine seedlings followed the order BS+Ap > US > other treatments. Foliar N and P, scrub regeneration and growth of pines showed the long-term fertilizing effect of ammonium polyphosphate, although the second highest pine mortality was found in the BS+Ap treatment. The foaming agent did not affect vegetation cover, and Firesorb had no noticeable effect on shrubs but the highest pine mortality.Peer reviewe

IBSE: An OWL Interoperability Evaluation Infrastructure

The technology that supports the Semantic Web presents a great diversity and, whereas all the tools use different types of ontologies, not all of them share a common knowledge representation model, which may pose problems when they try to interoperate. The Knowledge Web European Network of Excellence is organizing a benchmarking of interoperability of ontology tools using OWL as interchange language with the goal of assessing and improving tool interoperability. This paper presents the development of IBSE, an evaluation infrastructure that allows executing automatically the benchmarking experiments and provides an easy way of analysing the results. Thus,including new tools into the evaluation infrastructure will be simple and straightforward

CLIWOC multilingual meteorological dictionary

This dictionary is the first attempt to express the wealth of archaic logbook wind force terms in a form that is comprehensible to the modern-day reader. Oliver and Kington (1970) and Lamb (1982) have drawn attention to the importance of logbooks in climatic studies, and Lamb (1991) offered a conversion scale for early eighteenth century English wind force terms, but no studies have thus far pursued the matter to any greater depth. This text attempts to make good this deficiency, and is derived from the research undertaken by the CLIWOC project1 in which British, Dutch, French and Spanish naval and merchant logbooks from the period 1750 to 1850 were used to derive a global database of climatic information. At an early stage in the project it was apparent that many of the logbook weather terms, whilst conforming to a conventional vocabulary, possessed meanings that were unclear to twenty-first century readers or had changed over time. This was particularly the case for the important element of wind force; but no special plea is entered for the evolution in nautical vocabulary, which often reflected more wide-ranging changes in the respective native languages.The key objective was to translate the archaic vocabulary of the late eighteenth and early nineteenth century mariner into expressions directly comparable with the Beaufort Scale (see Appendix I). Only then could the projects scientific programme be embarked upon. This dictionary is the result of the largest undertaking into logbook studies that has yet been carried out. Several thousand logbooks from British, Dutch, French and Spanish archives were examined, and the exercise offered a unique opportunity to explore the vocabulary of the one hundred year period beginning in 1750. The logbooks from which the raw data have been abstracted range widely across the North and South Atlantic and the Indian Oceans. Only the Pacific, largely in consequence of the paucity of regular naval activity in that area, is not well represented. The range of climates encountered in this otherwise wide geographic domain gives ample opportunity for the full range of the mariners nautical weather vocabulary to be assessed, from the calms of the Equatorial regions, through the gales of the mid-latitude systems to the fearsome storms of the tropical latitudes. The Trade Winds belts, the Doldrums, the unsettled mid-latitudes, even the icy wastes of the high latitudes, are all embraced in this study. It is not here intended to pass any judgements on the climatological record of the logbooks, and this text seeks only to provide a means of understanding archaic wind force terms and, other than to indicate those items that were not commonly used, no information is given on the frequency with which different terms appeared in the logbooks. Attention is, furthermore, confined to Dutch, English, French and Spanish because these once great imperial powers were the only nations able to support wide-ranging ocean-going fleets with their attendant collections of logbooks and documents over this long period of time. The work is offered to the wider academic community in the hope that they will prove to be of as much value as it has been to the CLIWOC team