2,822 research outputs found

    LDA-based Term Profiles for Expert Finding in a Political Setting

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    A common task in many political institutions (i.e. Parliament) is to find politicians who are experts in a particular field. In order to tackle this problem, the first step is to obtain politician profiles which include their interests, and these can be automatically learned from their speeches. As a politician may have various areas of expertise, one alternative is to use a set of subprofiles, each of which covers a different subject. In this study, we propose a novel approach for this task by using latent Dirichlet allocation (LDA) to determine the main underlying topics of each political speech, and to distribute the related terms among the different topic-based subprofiles. With this objective, we propose the use of fifteen distance and similarity measures to automatically determine the optimal number of topics discussed in a document, and to demonstrate that every measure converges into five strategies: Euclidean, Dice, Sorensen, Cosine and Overlap. Our experimental results showed that the scores of the different accuracy metrics of the proposed strategies tended to be higher than those of the baselines for expert recommendation tasks, and that the use of an appropriate number of topics has proved relevant

    Positive unlabeled learning for building recommender systems in a parliamentary setting

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    Our goal is to learn about the political interests and preferences of the Members of Parliament by mining their parliamentary activity, in order to develop a recommendation/filtering system that, given a stream of documents to be distributed among them, is able to decide which documents should receive each Member of Parliament. We propose to use positive unlabeled learning to tackle this problem, because we only have information about relevant documents (the own interventions of each Member of Parliament in the debates) but not about irrelevant documents, so that we cannot use standard binary classifiers trained with positive and negative examples. We have also developed a new algorithm of this type, which compares favourably with: a) the baseline approach assuming that all the interventions of other Members of Parliament are irrelevant, b) another well-known positive unlabeled learning method and c) an approach based on information retrieval methods that matches documents and legislators' representations. The experiments have been carried out with data from the regional Andalusian Parliament at Spain

    Automatic Construction of Multi-faceted User Profiles using Text Clustering and its Application to Expert Recommendation and Filtering Problems

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    In the information age we are living in today, not only are we interested in accessing multimedia objects such as documents, videos, etc. but also in searching for professional experts, people or celebrities, possibly for professional needs or just for fun. Information access systems need to be able to extract and exploit various sources of information (usually in text format) about such individuals, and to represent them in a suitable way usually in the form of a profile. In this article, we tackle the problems of profile-based expert recommendation and document filtering from a machine learning perspective by clustering expert textual sources to build profiles and capture the different hidden topics in which the experts are interested. The experts will then be represented by means of multi-faceted profiles. Our experiments show that this is a valid technique to improve the performance of expert finding and document filtering

    Electrical Conductive Properties of 3D-PrintedConcrete Composite with Carbon Nanofibers

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    Electrical conductive properties in cement-based materials have received attention in recent years due to their key role in many innovative application (i.e., energy harvesting, deicing systems, electromagnetic shielding, and self-health monitoring). In this work, we explore the use 3D printing as an alternative method for the preparation of electrical conductive concretes. With this aim, the conductive performance of cement composites with carbon nanofibers (0, 1, 2.5, and 4 wt%) was explored by means of a combination of thermogravimetric analysis (TGA) and dielectric spectroscopy (DS) and compared with that of specimens prepared with the traditional mold method. The combination of TGA and DS gave us a unique insight into the electrical conductive properties, measuring the specimens’ performance while monitoring the amount in water confined in the porous network. Experimental evidence of an additional contribution to the electrical conductivity due to sample preparation is provided. In particular, in this work, a strong correlation between water molecules in interconnected pores and the σ(ω) values is shown, originating, mainly, from the use of the 3D printing technique.This work was born under the umbrella of the ECRETE project (RTI2018-098554-B-I00) funded by MCIN/AEI/10.13039/501100011033 (Program I+D+i RETOS INVESTIGACIÓN 2018), the project PoroPCM (PCI2019-103657) funded by MCIN/AEI/10.13039/501100011033 and co-founded by the European Union (Programación Conjunta Internacional 2019) and the project NRG-STORAGE (GA 870114) funded by the European Commission. Research conducted in the scope of the Transnational Common Laboratory (LTC) Aquitaine-Euskadi Network in Green Concrete

    Effects of a blend of chestnut and quebracho tannins on gut health and performance of broiler chickens

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    Antimicrobial restrictions prompted the search for cost and biologically effective alternatives to replace antimicrobial growth promoters (AGPs) in food-producing animals. In addition, the efficacy of this alternatives needs to be contrasted in field/commercial trials under different challenge conditions. However only a few studies describing the impact of tannins or others AGP-alternatives in commercial poultry production conditions are actually available. The aim of the present work is to study how the inclusion of a blend of chestnut and quebracho tannins can affect broiler productive performance and health under commercial conditions. Three experiments with different approaches were conducted: (1) a trial comparing the effects of both additives (tannins vs AGP) on different commercial farms at the same time; (2) the follow-up of one farm during an entire productive year; and (3) an experimental trial using a C. perfringens challenge model in broiler chickens. Although productive results from field trials were similar among treatments, evaluations of gut health indicators showed improvements in the tannins treated flocks. Frequency and severity of intestinal gross lesions were reduced in jejunum (42% vs 23%; p<0.05–1.37 vs. 0.73; p<0.01, respectively) and ileum (25% vs. 10%; p<0.0.5–1.05 vs. 0.58; p<0.01) in tannins treated birds. Results from 16S studies, show that cecal microbiota diversity was not differentially affected by AGPs or tannins, but changes in the relative abundance of certain taxa were described, including Lactobacillus and Bifidobacterium groups. Results from experimental C. perfringens necrotic enteritis showed that tannins treated birds had reduced incidence of gross lesions in jejunum (43.75 vs. 74.19%; p<0.01) and ileum (18.75% vs. 45.16%; p<0.05) compared with control. These results suggest that AGPs can be replaced by tannins feed additives, and contribute in the implementation of antimicrobial-free programs in broilers without affecting health or performance.Instituto de PatobiologíaFil: Redondo, Enzo Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología Veterinaria; ArgentinaFil: Redondo, Enzo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Redondo, Leandro Martí­n. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología Veterinaria; ArgentinaFil: Redondo, Leandro Martí­n. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bruzzone, Octavio Augusto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Bruzzone, Octavio Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Diaz Carrasco, Juan María. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología Veterinaria; ArgentinaFil: Diaz Carrasco, Juan María. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabral, Claudio. Silvateam; ArgentinaFil: Garces, Victorino M. Granja Tres Arroyos; ArgentinaFil: Liñeiro, Maximo M. Granja Tres Arroyos; ArgentinaFil: Fernandez Miyakawa, Mariano Enrique. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología Veterinaria; ArgentinaFil: Fernandez Miyakawa, Mariano Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    FKBP52 is involved in the regulation of SOCE channels in the human platelets and MEG 01 cells

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    AbstractImmunophilins are FK506-binding proteins that have been involved in the regulation of calcium homeostasis, either by modulating Ca2+ channels located in the plasma membrane or in the rough endoplasmic reticulum (RE). We have investigated whether immunophilins would participate in the regulation of stored-operated Ca2+ entry (SOCE) in human platelets and MEG 01. Both cell types were loaded with fura-2 for determining cytosolic calcium concentration changes ([Ca2+]c), or stimulated and fixed to evaluate the protein interaction profile by performing immunoprecipitation and western blotting. We have found that incubation of platelets with FK506 increases Ca2+ mobilization. Thapsigargin (TG)-evoked, Thr-evoked SOCE and TG-evoked Mn2+ entry resulted in significant reduction by treatment of platelets with immunophilin antagonists. We confirmed by immunoprecipitation that immunophilins interact with transient receptor potential channel 1 (TRPC1) and Orai1 in human platelets. FK506 and rapamycin reduced the association between TRPC1 and Orai1 with FK506 binding protein (52) (FKBP52) in human platelets, and between TRPC1 and the type II IP3R, which association is known to be crucial for the maintenance of SOCE in human platelets. FKBP52 role in SOCE activation was confirmed by silencing FKBP52 using SiRNA FKBP52 in MEG 01 as demonstrated by single cell configuration imaging technique. TRPC1 silencing and depletion of cell of TRPC1 and FKBP52 simultaneously, impair activation of SOCE evoked by TG in MEG 01. Finally, in MEG 01 incubated with FK506 we observed a reduction in TRPC1/FKBP52 coupling, and similarly, FKBP52 silencing reduced the association between IP3R type II and TRPC1 during SOCE. All together, these results demonstrate that immunophilins participate in the regulation of SOCE in human platelets

    Threshold Learning Dynamics in Social Networks

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    Social learning is defined as the ability of a population to aggregate information, a process which must crucially depend on the mechanisms of social interaction. Consumers choosing which product to buy, or voters deciding which option to take with respect to an important issue, typically confront external signals to the information gathered from their contacts. Economic models typically predict that correct social learning occurs in large populations unless some individuals display unbounded influence. We challenge this conclusion by showing that an intuitive threshold process of individual adjustment does not always lead to such social learning. We find, specifically, that three generic regimes exist separated by sharp discontinuous transitions. And only in one of them, where the threshold is within a suitable intermediate range, the population learns the correct information. In the other two, where the threshold is either too high or too low, the system either freezes or enters into persistent flux, respectively. These regimes are generally observed in different social networks (both complex or regular), but limited interaction is found to promote correct learning by enlarging the parameter region where it occurs.This work is supported by MEC (Spain) through project FISICOS (FIS2007-60327). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

    IL-10 released by a new inflammation-regulated lentiviral system efficiently attenuates zymosan-induced arthritis

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    We thank Dr Filip Lim for critical reading of the manuscript, and Dr S. Bartlett for English editing and helpful discussions. We also thank Drs. David Sancho and M. A. del Pozo for providing us with DCs and immortalized MEFs, respectively. AR is supported by Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+I) and Instituto de Salud Carlos III (FIS; PI060122), the Spanish Ministry of Science and Innovation (MICINN;SAF2009-10691) and the Comunidad Autónoma de Madrid (S2006/BIO-0236 and S2010/BMD-2312). JMR is supported by MICINN (RECAVA RD06/0014/005) and by from Fundació La Marató de TV3 (Grant 080731
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