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

Toxicity of ZnO nanoparticles, ZnO bulk and ZnCl2 on earthworms in a spiked natural soil and toxicological effects of leachates on aquatic organisms

The present study assessed the uptake and toxicity of ZnO nanoparticles (NPs), ZnO bulk, and ZnCl2 salt in earthworms in spiked agricultural soils. In addition, the toxicity of aqueous extracts to Daphnia magna and Chlorella vulgaris was analyzed to determine the risk of these soils to the aquatic compartment. We then investigated the distribution of Zn in soil fractions to interpret the nature of toxicity. Neither mortality nor differences in earthworm body weight were observed compared with the control. The most sensitive end point was reproduction. ZnCl2 was notably toxic in eliminating the production of cocoons. The effects induced by ZnO-NPs and bulk ZnO on fecundity were similar and lower than those of the salt. In contrast to ZnO bulk, ZnO-NPs adversely affected fertility. The internal concentrations of Zn in earthworms in the NP group were greater than those in the salt and bulk groups, although bioconcentration factors were consistently <1. No relationship was found between toxicity and internal Zn amounts in earthworms. The results from the sequential extraction of soil showed that ZnCl2 displayed the highest availability compared with both ZnO. Zn distribution was consistent with the greatest toxicity showed by the salt but not with Zn body concentrations. The soil extracts from both ZnO-NPs and bulk ZnO did not show effects on aquatic organisms (Daphnia and algae) after short-term exposure. However, ZnCl2 extracts (total and 0.45-μm filtered) were toxic to Daphnia

Efecto de la poda en plantaciones de pino radiata afectadas por Fusarium circinatum

Fusarium circinatum Nirenberg and O’Donnell (1998) is the causal agent of Pitch Canker Disease (PCD) in Pinus species, producing damage to the main trunk and lateral branches as well as causing branch dieback. The disease has been detected recently in northern Spain in Pinus spp. seedlings at nurseries and in Pinus radiata D. Don adult trees in plantations. Fusarium circinatum seems to require a wound to enter the tree, not only that as caused by insects but also that resulting from damage by humans, i.e. mechanical wounds. However, the effects of pruning on the infection process have yet to be studied. The aim of the present study was to know how the presence of mechanical damage caused by pruning affects PCD occurrence and severity in P. radiata plantations. Fifty P. radiata plots (pruned and unpruned) distributed throughout 16 sites affected by F. circinatum in the Cantabria region (northern Spain) were studied. Symptoms of PCD presence, such as dieback, oozing cankers and trunk deformation were evaluated in 25 trees per plot and related to pruning effect. A significant relationship between pruning and the number of cankers per tree was observed, concluding that wounds caused by pruning increase the chance of pathogen infection. Other trunk symptoms, such as the presence of resin outside the cankers, were also higher in pruned plots. These results should be taken into account for future management of Monterrey Pine plantations.Fusarium circinatum Nirenberg and O’Donnell (1998) es el agente causante de la enfermedad del chancro resinoso del pino, que afecta a especies del género Pinus y provoca la aparición de chancros resinosos en el tronco y en ramas gruesas, además de puntisecado en la guía terminal. Esta enfermedad fue detectada recientemente en el norte de España asociada a plántulas de coníferas en vivero y a plantaciones de Pinus radiata D. Don. Fusarium circinatum suele requerir una herida en el árbol para poder infectarlo. Estas heridas pueden estar causadas por insectos o ser de origen antrópico, como las heridas mecánicas. Con la finalidad de conocer cómo las heridas producidas durante la poda afectan a la severidad de la enfermedad del chancro resinoso del pino, se estudiaron 50 parcelas de P. radiata (podadas y no podadas) distribuidas a lo largo de la provincia de Cantabria. En cada una de las parcelas fueron evaluados 25 árboles, en los que se estudiaron los síntomas más característicos de la enfermedad, como son puntisecado, presencia de chancros resinosos y deformación del tronco, relacionándolos con la presencia de poda. Se observó una relación significativa entre la poda y el número de chancros presentes en el árbol, lo que indica que la herida producida en este tratamiento selvícola es susceptible de infección por parte del patógeno. Otros síntomas también presentes en el tronco, como los exudados de resina fuera del chancro, aparecieron más frecuentemente en las parcelas podadas. Estos resultados son de gran trascendencia para el futuro manejo de las plantaciones de P. radiata afectadas por el chancro resinoso del pino

The effect of additions of anticorrosive pigments on the cathodic delamitation and wear resistance of an epoxy powder coating

The cathodic delamination and wear resistance of epoxy powder coatings were evaluated after adding 3 % (by wt.) of calcium ion exchanged micropigments from amorphous synthetic silica. The materials were manufactured through the innovative and economical hot mixing method, and three different coatings were considered: commercial epoxy, epoxy without micropigments submitted to the hot mixing treatment, and epoxy with micropigments. The curing kinetics of the powder coatings was studied in order to evaluate the possible effects of the micropigments on the epoxy, using differential scanning calorimetry (DSC). In addition, mechanical properties of coatings (hardness and scratch resistance) and their wear resistance (reciprocal tribometer tests) were assessed. After provoking a controlled mechanical failure in the coatings, their delamination resistance was analyzed by scanning Kelvin probe (SKP). The delamination front was calculated after adding a drop of 3.5 % NaCl solution and taking measurements for 26 days. The results show that the corrosion attack progresses through a cathodic delamination mechanism. The addition of corrosion inhibitors in epoxy powder coatings has not only allowed a considerable improvement in delamination resistance, but has also led to greater mechanical and wear resistance. At the same time, it has simultaneously reduced the chances for mechanical failure of the coating and decreased the progression rate of damage, if it occurs. The study has also been completed with electrochemical impedance spectroscopy and polarization measured of fully-immersed defective coatings in 3.5 % NaCl.The authors acknowledge financial support from the European Union's Horizon 2020 research and innovation program through grant agreement No 766437 (ESSIAL project)

Morteros de albañilería con escombros de demolición

The possibility of recycling construction rubble, its technical and economic effectiveness, and the social and ecological impact they provide for our society is the reason and the starting point for an optimal exploitation of this aggregate in the manufacture of masonry mortar, since it has the same inherent properties as those obtained from the quarry aggregates, described in the Cuban standard NC52-79:93. The work consists in the preparation and study of masonry mortars using recycled aggregates -demolition product-. Four volumetric dosages were prepared (1:4; 1:5; 1:6 y 1:8), which were submitted to physical and mechanical tests at 7, 28 and 60 days, adherence resistance at 28 days, and capillary absorption, obtaining similar results to those.La posibilidad real del reciclaje de escombros, su efectividad técnica, económica, y el impacto social y ecológico que proporciona a la sociedad, es nuestro punto de partida para lograr un óptimo aprovechamiento de este árido como futuro agregado fundamental en la obtención de un mortero de albañilería, capaz de tener como propiedades aquellas intrínsecas de los propios morteros obtenidos a partir de áridos de cantera y recogidos en la norma cubana NC52-79:93. El trabajo consiste en la preparación y estudio de morteros de albañilería empleando árido reciclado -producto de demolición- como agregado. Se prepararon 4 dosificaciones volumétricas (1:4; 1:5; 1:6 y 1:8), las cuales fueron sometidas a ensayos físico-mecánicos al, 28 y 60 días, resistencia a la adherencia a 28 días, y absorción capilar, obteniéndose resultados comparables con los morteros de albañilería tradicionales

Ira y actividad física. Un estudio en estudiantes universitarios

La actividad física es de vital importancia en estos tiempos donde abunda la incertidumbre y desesperación de las personas. Esta se ha convertido en la solución dado que conociendo sus beneficios y siendo constante se pueden lograr las metas propuestas. Por estas razones, se plantean los siguientes objetivos: analizar el nivel de actividad física e ira y establecer las posibles relaciones entre las variables generales, académicas, psicosociales y físico-deportivas en estudiantes universitarios, con una muestra total de 497 estudiantes universitarios de edades comprendidas entre los 18 y 25 años y una edad media de 21,50 años (DT=6,24). Se han utilizado diversos instrumentos para la consecución de los objetivos como un cuestionario de tipo ad-hoc, para las variables sociodemográficas. Por otra parte, la escala de actitud hacia la actividad física y el cuestionario de agresividad, para las variables psicosociales. Los resultados muestran cómo realizar actividad física de manera diaria y tener una buena actitud hacia esta reduce las conductas agresivas en los estudiantes universitarios y, por ende, ven reducida su irascibilidad

Hospital Virtual Móvil: Seguimiento del Tratamiento de un Paciente con Vih Desde Su Teléfono Móvil

En los últimos años la movilidad se ha convertido en uno de los puntos de mayor desarrollo dentro de las tecnologías de la información. Uno de los campos en los que las nuevas herramientas de movilidad han encontrado mayor aceptación, es el ámbito de la asistencia sanitaria. Este rápido desarrollo se puede aprovechar para facilitar el cuidado de enfermedades crónicas complejas como el VIH/SIDA que requieren un gran control de la enfermedad y su tratamiento. Dentro del proyecto Hospital VIHrtual se ha creado un portal web con servicios adecuados a los pacientes de VIH y que permite al paciente el acceso en cualquier momento y lugar utilizando su teléfono móvil. Todo ello con el fin de favorecer el cumplimiento del paciente y permitir mejorar su calidad de vida