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

Environmental enrichment results in both brain connectivity efficiency and selective improvement in different behavioral tasks

Exposure to environmental enrichment (EE) has been a useful model for studying the effects of experience on brain plasticity, but to date, few is known about the impact of this condition on the brain functional networks that probably underlies the multiple behavioral improvements. Hence, we assessed the effect of an EE protocol in adult Wistar rats on the performance in several behavioral tasks testing different domains (Open field (OP): locomotor activity; Elevated-zero maze (EZM): anxiety-related behaviors; 5-choice serial reaction time task (5-CSRTT): attentional processes; 4-arm radial water maze (4-RAWM): spatial memory) in order to check its effectiveness in a wide range of functions. After this, we analyzed the functional brain connectivity underlying each experimental condition through cytochrome C oxidase (COx) histochemistry. Our EE protocol reduced both locomotor activity in the OP and anxiety-related behaviors in the EZM. On the other hand, enriched rats showed more accuracy in the 4-RAWM, whereas 5-CSRTT performance was not significantly ameliorated by EE condition. In relation to COx functional connectivity, we found that EE reduced the number of strong positive correlations both in basal and training conditions, suggesting a modulating effect on specific brain connections. Our results suggest that EE seems to have a selective effect on specific brain regions, such as prefrontal cortex and hippocampus, leading to a more efficient brain connectivity.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. PPIT.UMA.B1.2017/3

Multilevel Multiphase Feedforward Space-Vector Modulation Technique

Multiphase converters have been applied to an increasing number of industrial applications in recent years. On the other hand, multilevel converters have become a mature technology mainly in medium- and high-power applications. One of the problems of multilevel converters is the dc voltage unbalance of the dc bus. Depending on the loading conditions and the number of levels of the converter, oscillations appear in the dc voltages of the dc link. This paper presents a feedforward modulation technique for multilevel multiphase converters that reduces the distortion under balanced or unbalanced dc conditions. The proposed modulation method can be applied to any multilevel-converter topology with any number of levels and phases. Experimental results are shown in order to validate the proposed feedforward modulation technique.Ministerio de Ciencia e Innovación DPI2009-07004Ministerio de Eduación y Ciencia TEC2007-6187

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

Development of indices of larval bluefin tuna (Thunnus thynnus) in the western Mediterranean sea

Fishery independent indices of bluefin tuna larvae in the western Mediterranean Sea are presented utilizing ichthyoplankton survey data collected from 2001 through 2005 by the Spanish Institute of Oceanography. Indices were developed using larval catch rates collected using two different types of bongo gear by employing a delta-lognormal modeling approach, including following covariates: water temperature at 25 m, salinity at 25 m, water depth, time of day, geostrophic water velocities, year, and a gear variable for the combined modelSe presentan índices de larvas de atún rojo independientes de la pesquería en el mar Mediterráneo occidental utilizando datos de prospecciones de ictioplancton recopilados desde 2001 hasta 2005 por el Instituto Español de Oceanografía. Los índices se desarrollaron utilizando tasas de captura larval recopiladas utilizando dos tipos diferentes de red bongo y empleando un enfoque delta-lognormal de modelación, que incluía las siguientes covariables: temperatura del agua a 25 m, salinidad a 25 m, profundidad del agua, hora del día, velocidad del agua geostrófica, año y una variable de arte para el modelo combinad

Adsorption of representative pharmaceutical compounds from hospital wastewater by carbon materials

Pharmaceuticals are a class of emerging environmental contaminants that are extensively and increasingly being used in human and veterinary medicine. The worldwide consumption of these substances has increased in both hospitals and households, which represents a major concern in terms of their potential harmful effects on the environment and human health [1]. Thus, fluoroquinolone antibiotics are widely used in human medicine and animal breeding for preventing and curing diseases. Ciprofloxacin is a wide-spectrum fluoroquinolone antibiotic extensively used in the world, which can generate high contributions to public sewers. Meanwhile, carbamazepine, one of the most widely prescribed psychoactive drugs, shows important endocrine disrupting effects and it is frequently detected in high concentrations in both WWTPs effluents and river water. Because of the removal efficiency of these compounds in the conventional wastewater treatment plants is not complete (ranging from 7-8% for carbamazepine), it is necessary the implementation of tertiary technologies in order to achieve WWTPs effluents with a better quality. Adsorption onto carbon materials has proven as an efficient treatment in the removal of a broad spectrum of micro-pollutants. This work has been focused on the study of equilibrium adsorption of carbamazepine (CBZ) and ciprofloxacin (CPX) from ultrapure water at 30 ºC using carbonaceous materials. Commercial carbon materials (AC-F400 activated carbon, multi-walled carbon nanotubes, MWNT, and carbon nanofibers, CNF) and lab-synthesized activated carbons from peach stones (AC-PS) and rice husk (AC-RH) as precursors have been used. Moreover, carbon adsorbents have been used to treat a real hospital wastewater containing 55 different pharmaceutical compounds. Among them, both CBZ and CPX were found at concentrations of 162.55 and \u3e 40 ng.L-1, respectively. The removal efficiency of quality macroscopic parameters (Total Organic Carbon concentration, TOC, Total Nitrogen concentration, TN, carbonates, CO32-, and aromaticity) and each of the pharmaceuticals contained in the wastewater was evaluated. Large adsorption capacities of CBZ and CPX (around 240 and 200 mg.g-1) were found in 4 hours, using adsorbent doses ranging from 2-3 g.L-1, natural pH, temperature of 30 ºC and stirring rate of 250 rpm. In addition, competitive adsorption experiments using both pollutants in ultrapure water have been performed. The bi-component adsorption systems were reasonably well-fitted by the extended Freundlich model equation. In the treatment of the hospital wastewater, a maximum TOC reduction of 96.5% ([TOC]0 = 110 mg L-1) was achieved by adsorption onto AC-RH activated carbon, since all the studied macroscopic parameters were too efficiently removed. Moreover, by the adsorption treatment, the complete disappearance of all the pharmaceutical compounds (except two of them) was observed. References [1] S. Ortiz de García, G. Pinto Pinto, P. García Encina, R. Irusta Mata, Consumption and occurrence of pharmaceutical and personal care products in the aquatic environment in Spain, Sci. Total Environ. 444 (2013) 451–465

Spatial and temporal analysis of the seasonal and interannual variability in the tropical Pacific simulated with a coupled GCM

In the first part of this work, the dominant time scales that explain the tropical variability of the first SINTEX simulation (ECHAM4(T30)-ORCA) are identified through a spectral analysis. Higher order spectral analysis is used to examine the interactions among these time scales. The time series analyzed are an average of sea surface temperature over the Niño3 region. The time scales obtained are compared with those identified in another coupled GCM simulation (ECHAM4(T42)-OPYC3). The higher importance of the biannual time scale in this last is explained partly by the strength of the coupling between the annual and the biannual time scales. There is no such strong coupling in the SINTEX simulation. Important differences among the generation of the simulated warm (or cold) event suggest the need of a systematic classification to isolate their relevant features. Therefore in the second part of this work, we address this problem. A space-time cluster analysis is performed on a data set built by collecting the values of the heat content anomalies in the tropical Pacific region, in the fifteen months previous to a peak in the Niño3 Index that has been identified as a ‘warm’ (or ‘cold’) event. In the case of the warm events, three types of generation schemes are found. In two of them, there are anomalies of heat content in the west, north and south of the equator, more than nine months before the events start. In the third case, the anomalies appear and grow in the central equatorial Pacific. Only two types are needed to classify the generation of cold events. Negative sea level height anomalies appear six months before the Niño3 Index reaches the (local) minimum. They are located north of the equator in one of the groups, and south of it in the other. Some of these characteristic traits also appear in observations of warm and cold events