5,371 research outputs found

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

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    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

    Methotrexate Gold Nanocarriers: Loading and Release Study: Its Activity in Colon and Lung Cancer Cells

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    In the present study, the synthesis of gold nanoparticles (AuNPs) loaded with methotrexate (MTX) has been carried out in order to obtain controlled size and monodispersed nanocarriers of around 20 nm. The characterization study shows metallic AuNPs with MTX polydispersed on the surface. MTX is linked by the replacement of citrate by the MTX carboxyl group. The drug release profiles show faster MTX release when it is conjugated, which leads to the best control of plasma concentration. Moreover, the enhanced release observed at pH 5 could take advantage of the pH gradients that exist in tumor microenvironments to achieve high local drug concentrations. AuNP–MTX conjugates were tested by flow cytometry against lung (A-549) and colon (HTC-116) cancer cell lines. Results for A-549 showed a weaker dose–response e ect than for colon cancer ones. This could be related to the presence of folate receptors in line HTC-116 in comparison to line A-549, supporting the specific uptake of folate-conjugated AuNP–MTX by folate receptor positive tumor cells. Conjugates exhibited considerably higher cytotoxic e ects compared with the e ects of equal doses of free MTX. Annexin V-PI tests sustained the cell death mechanism of apoptosis, which is normally disabled in cancer cells.Spanish GovernmentJunta de Andalucía P18-RT-419

    Global trends in child obesity: Are figures converging?

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    Childhood obesity has become one of the most serious global health challenges of our time. The combined prevalence of overweight and obesity has rapidly increased worldwide during the last two decades, especially in some developing countries where obesity is reaching levels on a par with some industrialized countries, or even higher. This fast growth has occurred especially in countries in the midst of rapid social-economic transitions. Most international comparisons focus on the adult population while analyses focusing on the child population are more limited. Using the methodology developed by Phillips and Sul, this paper studies the worldwide evolution of children’s body mass index (BMI), overweight and obesity prevalence for a large sample of countries during the period 1975–2016. Our results indicate that the figures for BMI or the prevalence of obesity in different countries do not converge, while the opposite is the case for overweight prevalence in children. Furthermore, there is a non-linear relationship between obesity and income or human capital, indicating that low and middle-income countries require a strong initiative for health policies targeting obesity prevention

    Cloudy bag model: convergent perturbation expansion for the nucleon

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    A previously published bound on the probability of finding n pions in the dressed nucleon in Chew-Low theory is improved. The proof is then extended to the recently derived cloudy-bag-model Hamiltonian. Together with a bound on the average number of pions (0.9±1.0), our result strongly suggests a rapid convergence of the perturbation expansion in the cloudy bag model

    Exercise addiction and satisfaction of fitness center users as precursors to the intention of continuing to engage in physical activity

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    Exercise addiction occurs when a person engages in excessive physical activity until they lose control. Among individuals attending fitness centers, the risk of developing exercise addiction has been estimated to be close to 10%. The objective of this study was to determine whether exercise addiction may be an antecedent of satisfaction with the service received and/or of the intention of continuing to partake in leisure-time physical activity at fitness centers in a direct or indirect manner. A total of 361 individuals (29.05 ± 11.40 years old) who were physically active at Spanish fitness centers were asked to respond to a questionnaire on exercise addiction, satisfaction with the sports service, and their intention to continue to engage in physical activity. A multi-group analysis was conducted to check for differences in relationships by sex. The results show the relationships between addiction, satisfaction, and intention to continue physical activity. The standardized values display differences between men and women, with women exhibiting the highest values for the relationships between addiction and the rest of the constructs. Satisfaction with the sports service is a mediator in the relationship between exercise addiction and intention to engage in leisure-time physical activity

    A phylogenomic look into the systematics of oceanic squids (order Oegopsida)

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    Fernández-Álvarez, Fernando Á, Taite, Morag, Vecchione, Michael, Villanueva, Roger, Allcock, A Louise (2022): A phylogenomic look into the systematics of oceanic squids (order Oegopsida). Zoological Journal of the Linnean Society 194 (4): 1212-1235, DOI: 10.1093/zoolinnean/zlab069, URL: https://academic.oup.com/zoolinnean/article/194/4/1212/637713
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