992 resultados para Knowledge Bases


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In this paper we study a model where non-cooperative agents may exchange knowledge in a competitive environment. As a potential factor that could induce the knowledge disclosure between humans we consider the timing of the moves of players. We develop a simple model of a multistage game in which there are only three players and competition takes place only within two stages. Players can share their private knowledge with their opponents and the knowledge is modelled as in uencing their marginal cost of e¤ort. We identify two main mechanisms that work towards knowledge disclosure. One of them is that before the actual competition starts, the stronger player of the rst stage of a game may have desire to share his knowledge with the "observer", be- cause this reduces the valuation of the prize of the weaker player of that stage and as a result his e¤ort level and probability of winning in a ght. Another mechanism is that the "observer" may have sometimes desire to share knowledge with the weaker player of the rst stage, because in this way, by increasing his probability of winning in that stage, he decreases the probability of winning of the stronger player. As a result, in the second stage the "observer" may have greater chances to meet the weaker player rather than the stronger one. Keywords: knowledge sharing, strategic knowledge disclosure, multistage contest game, non-cooperative games

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En la presente memoria se detallan con exactitud los pasos y procesos realizados para construir una aplicación que posibilite el cruce de datos genéticos a partir de información contenida en bases de datos remotas. Desarrolla un estudio en profundidad del contenido y estructura de las bases de datos remotas del NCBI y del KEGG, documentando una minería de datos con el objetivo de extraer de ellas la información necesaria para desarrollar la aplicación de cruce de datos genéticos. Finalmente se establecen los programas, scripts y entornos gráficos que han sido implementados para la construcción y posterior puesta en marcha de la aplicación que proporciona la funcionalidad de cruce de la que es objeto este proyecto fin de carrera.

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Report for the scientific sojourn at the National Institute for Public Health and the Environment (RIVM), Netherlands, from 2006 to 2008. This project aimed at creating scientific elements that could help deriving an integrated testing strategy for reproductive toxicity. Part of the project focused on the use of alternative tests for regulatory purposes. An in vitro-in vivo extrapolation method for embryotoxicity was proposed and evaluated. In vitro and in vivo dose descriptors were correlated; however, the scatter in the correlation was too large to allow an accurate estimation of an in vivo dose from an in vitro dose. The in vitro-in vivo extrapolation method together with toxicokinetic data was also applied to a category of substances (phthalates). Although based on a limited number of substances, the results suggested that in vitro-in vivo extrapolation for embryotoxicity is possible within a category of compounds if adequate toxicokinetic data is available. Because of the limitations that still remain in the use of alternative tests for reproductive toxicicity, other approaches to reduce animal testing were explored. Thus, a database of reproductive toxicity studies was created to retrospectively evaluate the comparative value of some studies or elements in a particular study. When compared to the subchronic toxicity study, the rat two-generation reproductive toxicity study had a considerable impact on the identification of hazard for reproductive toxicity, but not on the overall NOAEL. Among the two-generation studies included in our database, the second generation affected neither the overall NOAEL nor the critical effect. The rat and the rabbit developmental toxicity studies were, on average, similarly sensitive. However, for certain substances the developmental study in either one of the two species appeared to be more sensitive than in the other species.

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Des de que començà aquest projecte, el grup de recerca ha intentat aprofundir el coneixement de la Catalunya de la Guerra del Francès (1808 -1814) a partir d’una òptica britànica. El grup pretenia així desenvolupar la relació que es va establir entre els catalans i els britànics al llarg de tota la guerra, des dels primers contactes permesos per la presència de la flota britànica en la costa catalana fins a la intervenció de forces britàniques en territori català. D’aquesta manera, i primerament, el grup inicià la consulta de les bases de dades i catàlegs catalans i britànics per a completar el nostre llistat de referències arxivístiques i bibliogràfiques. El segon pas van ésser les tres estades d’investigació que entre el 2006 i el 2007 es van fer a Anglaterra, principalment a Londres. La investigació es realitzà a la British Library, al Institute of Historical Research of the School of Advanced Studies de la University of London, al National Maritime Museum i als National Archives of the United Kingdom. A continuació, el grup analitzà la informació recollida de la lectura de fonts primàries i bibliogràfiques en aquests centres de recerca. Finalment, el grup creu que la intensa relació que es va establir entre les dues parts, reflecteix la importància que les autoritats britàniques van donar a Catalunya, i que el seu aïllament amb el centre polític del bàndol patriota va permetre que desenvolupés les seves pròpies dinàmiques i cronologies, encara que s’integraven en el desenvolupament general de la guerra.

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This paper compares how increases in experience versus increases in knowledge about a public good affect willingness to pay (WTP) for its provision. This is challenging because while consumers are often certain about their previous experiences with a good, they may be uncertain about the accuracy of their knowledge. We therefore design and conduct a field experiment in which treated subjects receive a precise and objective signal regarding their knowledge about a public good before estimating their WTP for it. Using data for two different public goods, we show qualitative equivalence of the effect of knowledge and experience on valuation for a public good. Surprisingly, though, we find that the causal effect of objective signals about the accuracy of a subject’s knowledge for a public good can dramatically affect their valuation for it: treatment causes an increase of $150-$200 in WTP for well-informed individuals. We find no such effect for less informed subjects. Our results imply that WTP estimates for public goods are not only a function of true information states of the respondents but beliefs about those information states.

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In the context of the two-stage threshold model of decision making, with the agent’s choices determined by the interaction Of three “structural variables,” we study the restrictions on behavior that arise when one or more variables are xogenously known. Our results supply necessary and sufficient conditions for consistency with the model for all possible states of partial Knowledge, and for both single- and multivalued choice functions.

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The aim of this study is to perform a thorough comparison of quantitative susceptibility mapping (QSM) techniques and their dependence on the assumptions made. The compared methodologies were: two iterative single orientation methodologies minimizing the l2, l1TV norm of the prior knowledge of the edges of the object, one over-determined multiple orientation method (COSMOS) and anewly proposed modulated closed-form solution (MCF). The performance of these methods was compared using a numerical phantom and in-vivo high resolution (0.65mm isotropic) brain data acquired at 7T using a new coil combination method. For all QSM methods, the relevant regularization and prior-knowledge parameters were systematically changed in order to evaluate the optimal reconstruction in the presence and absence of a ground truth. Additionally, the QSM contrast was compared to conventional gradient recalled echo (GRE) magnitude and R2* maps obtained from the same dataset. The QSM reconstruction results of the single orientation methods show comparable performance. The MCF method has the highest correlation (corrMCF=0.95, r(2)MCF =0.97) with the state of the art method (COSMOS) with additional advantage of extreme fast computation time. The l-curve method gave the visually most satisfactory balance between reduction of streaking artifacts and over-regularization with the latter being overemphasized when the using the COSMOS susceptibility maps as ground-truth. R2* and susceptibility maps, when calculated from the same datasets, although based on distinct features of the data, have a comparable ability to distinguish deep gray matter structures.

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SUMMARY : Eukaryotic DNA interacts with the nuclear proteins using non-covalent ionic interactions. Proteins can recognize specific nucleotide sequences based on the sterical interactions with the DNA and these specific protein-DNA interactions are the basis for many nuclear processes, e.g. gene transcription, chromosomal replication, and recombination. New technology termed ChIP-Seq has been recently developed for the analysis of protein-DNA interactions on a whole genome scale and it is based on immunoprecipitation of chromatin and high-throughput DNA sequencing procedure. ChIP-Seq is a novel technique with a great potential to replace older techniques for mapping of protein-DNA interactions. In this thesis, we bring some new insights into the ChIP-Seq data analysis. First, we point out to some common and so far unknown artifacts of the method. Sequence tag distribution in the genome does not follow uniform distribution and we have found extreme hot-spots of tag accumulation over specific loci in the human and mouse genomes. These artifactual sequence tags accumulations will create false peaks in every ChIP-Seq dataset and we propose different filtering methods to reduce the number of false positives. Next, we propose random sampling as a powerful analytical tool in the ChIP-Seq data analysis that could be used to infer biological knowledge from the massive ChIP-Seq datasets. We created unbiased random sampling algorithm and we used this methodology to reveal some of the important biological properties of Nuclear Factor I DNA binding proteins. Finally, by analyzing the ChIP-Seq data in detail, we revealed that Nuclear Factor I transcription factors mainly act as activators of transcription, and that they are associated with specific chromatin modifications that are markers of open chromatin. We speculate that NFI factors only interact with the DNA wrapped around the nucleosome. We also found multiple loci that indicate possible chromatin barrier activity of NFI proteins, which could suggest the use of NFI binding sequences as chromatin insulators in biotechnology applications. RESUME : L'ADN des eucaryotes interagit avec les protéines nucléaires par des interactions noncovalentes ioniques. Les protéines peuvent reconnaître les séquences nucléotidiques spécifiques basées sur l'interaction stérique avec l'ADN, et des interactions spécifiques contrôlent de nombreux processus nucléaire, p.ex. transcription du gène, la réplication chromosomique, et la recombinaison. Une nouvelle technologie appelée ChIP-Seq a été récemment développée pour l'analyse des interactions protéine-ADN à l'échelle du génome entier et cette approche est basée sur l'immuno-précipitation de la chromatine et sur la procédure de séquençage de l'ADN à haut débit. La nouvelle approche ChIP-Seq a donc un fort potentiel pour remplacer les anciennes techniques de cartographie des interactions protéine-ADN. Dans cette thèse, nous apportons de nouvelles perspectives dans l'analyse des données ChIP-Seq. Tout d'abord, nous avons identifié des artefacts très communs associés à cette méthode qui étaient jusqu'à présent insoupçonnés. La distribution des séquences dans le génome ne suit pas une distribution uniforme et nous avons constaté des positions extrêmes d'accumulation de séquence à des régions spécifiques, des génomes humains et de la souris. Ces accumulations des séquences artéfactuelles créera de faux pics dans toutes les données ChIP-Seq, et nous proposons différentes méthodes de filtrage pour réduire le nombre de faux positifs. Ensuite, nous proposons un nouvel échantillonnage aléatoire comme un outil puissant d'analyse des données ChIP-Seq, ce qui pourraient augmenter l'acquisition de connaissances biologiques à partir des données ChIP-Seq. Nous avons créé un algorithme d'échantillonnage aléatoire et nous avons utilisé cette méthode pour révéler certaines des propriétés biologiques importantes de protéines liant à l'ADN nommés Facteur Nucléaire I (NFI). Enfin, en analysant en détail les données de ChIP-Seq pour la famille de facteurs de transcription nommés Facteur Nucléaire I, nous avons révélé que ces protéines agissent principalement comme des activateurs de transcription, et qu'elles sont associées à des modifications de la chromatine spécifiques qui sont des marqueurs de la chromatine ouverte. Nous pensons que lés facteurs NFI interagir uniquement avec l'ADN enroulé autour du nucléosome. Nous avons également constaté plusieurs régions génomiques qui indiquent une éventuelle activité de barrière chromatinienne des protéines NFI, ce qui pourrait suggérer l'utilisation de séquences de liaison NFI comme séquences isolatrices dans des applications de la biotechnologie.

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In this paper we are aimed to investigate the relationship between Catalan knowledge and individual earnings in Catalonia. Using data from 2006, we find a positive earning return to Catalan proficiency; however, when accounting for self-selection into Catalan knowledge, we find a higher language return (20% of extra earnings), suggesting that individuals who are more prone to know Catalan are also less remunerated than others (negative selection effect). Moreover, we also find important complementarities between language knowledge and completed education, which means that only more educated individuals benefit from Catalan knowledge.

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This paper investigates the economic value of Catalan knowledge for national and foreign first- and second-generation immigrants in Catalonia. Specifically, drawing on data from the “Survey on Living Conditions and Habits of the Catalan Population (2006)”, we want to quantify the expected earnings differential between individuals who are proficient in Catalan and those who are not, taking into account the potential endogeneity between knowledge of Catalan and earnings. The results indicate the existence of a positive return to knowledge of Catalan, with a 7.5% increase in earnings estimated by OLS; however, when we account for the presence of endogeneity, monthly earnings are around 18% higher for individuals who are able to speak and write Catalan. However, we also find that language and education are complementary inputs for generating earnings in Catalonia, given that knowledge of Catalan increases monthly earnings only for more educated individuals.

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El present treball vol constatar un fet, que alhora ha resultat motor d'aquest. La realitat tal com se'ns planteja és la següent: sembla que no existeix un model organitzat i globalizador de competències, a manera de paradigma integrat, que relacioni els processos educatius que s'esdevenen en el si de la família i de l'escola. La definició d'aquesta problemàtica tan estretament relacionada amb la tasca docent ens ha conduït a plantejar una hipòtesi d'investigació, que pot formular-se d'aquesta manera. El nostre sistema educatiu preveu la implicació de la institució familiar en la formació competencial dels escolars?, i si és així, ens plantegem la segona qüestió: és possible elaborar un model de formació competencial que articuli els processos educatius que s'esdevenen en el si de la família i de l'escola de forma operativa i integrada? Per aconseguir respondre a aquestes qüestions s'inicia el treball amb l'estudi i posterior exposició dels següents punts: el marc legislatiu més recent, (des de la primera norma postconstitucional que va regular la participació dels pares a l'escola fins als nostres dies), les propostes formulades pels Consells Escolars Autonòmics i de l'Estat en les seves trobades anuals i les dades obtingudes de diversos informes realitzats pel INCE sobre la participació dels pares a l'escola. Tenint en compte que el nucli de la recerca gira al voltant de la relació família-escola a nivell competencial, s’exposa -més endavant- el marc legal i institucional, que actualment sembla favorable a la viabilitat d'un desenvolupament competencial comú entre família i escola . A continuació, es mostren unes taules amb indicadors que facilitaran l'estudi de la potencial relació entre les competències que es desenvolupen a l'escola i les que es donen en la família. Els aspectes relacionats amb la família els obtindrem de les aportacions trobades en obres i documents de pedagogs rellevants com Pestalozzi, Froebel, Montessori i Decroly. Al final del treball podem trobar -mitjançant l'assignació d'indicadors o descriptors- la relació que s'estableix entre les accions familiars i les competències escolars. Aquest treball permet postular que no només és possible articular una formació competencial del nen / a en la família i l'escola, sinó que les dues institucions educatives són articulables i sinèrgiques en aquest desenvolupament, optimitzant la formació competencial.

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This paper explores the earnings return to Catalan knowledge for public and private workers in Catalonia. In doing so, we allow for a double simultaneous selection process. We consider, on the one hand, the non-random allocation of workers into one sector or another, and on the other, the potential self-selection into Catalan proficiency. In addition, when correcting the earnings equations, we take into account the correlation between the two selectivity rules. Our findings suggest that the apparent higher language return for public sector workers is entirely accounted for by selection effects, whereas knowledge of Catalan has a significant positive return in the private sector, which is somewhat higher when the selection processes are taken into account.

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Aquest document complementa les subtasques 2.4.2, 2.4.3 i 2.4.4 relacionades amb els Informes dels estudis de viabilitat constructiva, els resultats de la intervenció i la validació de la intervenció, proporcionant el nexe lògic entre la caracterització de les tècniques no-destructives i semidestructives realitzat en els documents I2.17 i I.2.18 i les millores de processos que s'aborden d'una forma més sistemàtica en el *SP4, en relació amb el desenvolupament i aplicació de models d'optimització multicriteri. Per a arribar a aquest objectiu i resoldre els problemes de interoperabilitat lligats a diferents bases de dades, ha estat necessari estendre l'Ontologia orientada inicialment en el SP6 per a usuaris amb algun tipus de discapacitat, a usuaris corresponents als tècnics que vagin a desenvolupar les intervencions d'acord amb les tècniques disponibles. Aquesta extensió inclou el diagrama entitat-relació que estén al cas dels tècnics l'esquema conceptual inicialment restringit als usuaris finals (ciutadans eventualment discapacitats). La major dificultat procedeix del caràcter excepcional de moltes de les intervencions realitzades, la qual cosa fa realment difícil l'estandardització dels processos orientats a resoldre el problema de l'accessibilitat al Patrimoni