Institution
Pompeu Fabra University
Education•Barcelona, Spain•
About: Pompeu Fabra University is a education organization based out in Barcelona, Spain. It is known for research contribution in the topics: Population & Context (language use). The organization has 8093 authors who have published 23570 publications receiving 858431 citations. The organization is also known as: Universitat Pompeu Fabra & UPF.
Topics: Population, Context (language use), Gene, Computer science, Politics
Papers published on a yearly basis
Papers
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TL;DR: An anytime algorithm to solve the coalition structure generation problem, which uses a novel representation of the search space, which partitions the space of possible solutions into sub-spaces such that it is possible to compute upper and lower bounds on the values of the best coalition structures in them.
Abstract: Coalition formation is a fundamental type of interaction that involves the creation of coherent groupings of distinct, autonomous, agents in order to efficiently achieve their individual or collective goals. Forming effective coalitions is a major research challenge in the field of multi-agent systems. Central to this endeavour is the problem of determining which of the many possible coalitions to form in order to achieve some goal. This usually requires calculating a value for every possible coalition, known as the coalition value, which indicates how beneficial that coalition would be if it was formed. Once these values are calculated, the agents usually need to find a combination of coalitions, in which every agent belongs to exactly one coalition, and by which the overall outcome of the system is maximized. However, this coalition structure generation problem is extremely challenging due to the number of possible solutions that need to be examined, which grows exponentially with the number of agents involved. To date, therefore, many algorithms have been proposed to solve this problem using different techniques -- ranging from dynamic programming, to integer programming, to stochastic search -- all of which suffer from major limitations relating to execution time, solution quality, and memory requirements.
With this in mind, we develop an anytime algorithm to solve the coalition structure generation problem. Specifically, the algorithm uses a novel representation of the search space, which partitions the space of possible solutions into sub-spaces such that it is possible to compute upper and lower bounds on the values of the best coalition structures in them. These bounds are then used to identify the sub-spaces that have no potential of containing the optimal solution so that they can be pruned. The algorithm, then, searches through the remaining sub-spaces very efficiently using a branch-and-bound technique to avoid examining all the solutions within the searched subspace(s). In this setting, we prove that our algorithm enumerates all coalition structures efficiently by avoiding redundant and invalid solutions automatically. Moreover, in order to effectively test our algorithm we develop a new type of input distribution which allows us to generate more reliable benchmarks compared to the input distributions previously used in the field. Given this new distribution, we show that for 27 agents our algorithm is able to find solutions that are optimal in 0.175% of the time required by the fastest available algorithm in the literature. The algorithm is anytime, and if interrupted before it would have normally terminated, it can still provide a solution that is guaranteed to be within a bound from the optimal one. Moreover, the guarantees we provide on the quality of the solution are significantly better than those provided by the previous state of the art algorithms designed for this purpose. For example, for the worst case distribution given 25 agents, our algorithm is able to find a 90% efficient solution in around 10% of time it takes to find the optimal solution.
254 citations
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Pompeu Fabra University1, French Institute of Health and Medical Research2, Pierre-and-Marie-Curie University3, Oslo University Hospital4, Odense University Hospital5, University of Bologna6, Utrecht University7, Charité8, University of Paris9, University of Würzburg10, University Medical Center Groningen11, Ludwig Maximilian University of Munich12, Boston Children's Hospital13, Karolinska Institutet14, Paris Descartes University15, Centre for Health Protection16
TL;DR: Coexistence of eczema, rhinitis, and asthma in the same child is more common than expected by chance alone-both in the presence and absence of IgE sensitisation-suggesting that these diseases share causal mechanisms.
254 citations
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TL;DR: In this article, the authors considered the standard one-dimensional Downsian model of two-candidate elections, where one candidate (A) enjoys an advantage over the other candidate (D), but voters' preferences are Euclidean, and any voter will vote for candidate A over candidate D unless D is closer to her ideal point by some fixed distance.
253 citations
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Norwegian Institute of Public Health1, Oslo University Hospital2, University of Bergen3, University of Oslo4, Haukeland University Hospital5, King's College London6, Wellcome Trust Sanger Institute7, University of North Carolina at Chapel Hill8, Michigan State University9, University of Aberdeen10, University of Duisburg-Essen11, University of Paris12, Utrecht University13, University of Padua14, University of Barcelona15, Pompeu Fabra University16, Poznan University of Medical Sciences17, University of Helsinki18, Leiden University Medical Center19, Leiden University20, Harvard University21, Seconda Università degli Studi di Napoli22, University of Salerno23, University of Toronto24, Medical University of Vienna25, Children's Hospital of Philadelphia26, University of Pennsylvania27, Scripps Research Institute28, National Institutes of Health29, Tokai University30
TL;DR: This article performed a GWAS in 2907 cases with AN from 14 countries (15 sites) and 14 860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3).
Abstract: Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome-wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2907 cases with AN from 14 countries (15 sites) and 14 860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery data sets. Seventy-six (72 independent) single nucleotide polymorphisms were taken forward for in silico (two data sets) or de novo (13 data sets) replication genotyping in 2677 independent AN cases and 8629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication data sets comprised 5551 AN cases and 21 080 controls. AN subtype analyses (1606 AN restricting; 1445 AN binge-purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01 × 10(-7)) in SOX2OT and rs17030795 (P=5.84 × 10(-6)) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76 × 10(-)(6)) between CUL3 and FAM124B and rs1886797 (P=8.05 × 10(-)(6)) near SPATA13. Comparing discovery with replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P=4 × 10(-6)), strongly suggesting that true findings exist but our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field.
253 citations
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University of Washington1, Ghent University2, University of Geneva3, University of Michigan4, Katholieke Universiteit Leuven5, Princess Anne Hospital6, Churchill Hospital7, University of Tartu8, University of Antwerp9, University of Groningen10, University of Chicago11, Pompeu Fabra University12, University of Southampton13, Salisbury District Hospital14, Salisbury NHS Foundation Trust15, University of São Paulo16, Autonomous University of Barcelona17, Howard Hughes Medical Institute18
TL;DR: The findings broaden the phenotypic spectrum associated with 15q13.3 deletions and suggest that, in some individuals, deletion of 15q 13.3 is not sufficient to cause disease.
Abstract: Recurrent 15q13.3 microdeletions were recently identified with identical proximal (BP4) and distal (BP5) breakpoints and associated with mild to moderate mental retardation and epilepsy. To further assess the clinical implications of this novel 15q13.3 microdeletion syndrome, eighteen new probands with a deletion were molecularly and clinically characterised. In addition, we evaluated the characteristics of a family with a more proximal deletion between BP3 and BP4. Finally, four patients with a duplication in the BP3-BP4-BP5 region were included in this study to ascertain the clinical significance of duplications in this region. The 15q13.3 microdeletion in our series was associated with a highly variable intra- and inter-familial phenotype. At least eleven of the eighteen deletions identified were inherited. Moreover, seven of ten siblings from four different families also had this deletion: one had a mild developmental delay, four had only learning problems during childhood, but functioned well in daily life as adults, whereas the other two had no learning problems at all. In contrast to previous findings, seizures were not a common feature in our series (only two of seventeen living probands). Three patients with deletions had cardiac defects and deletion of the KLF13 gene, located in the critical region, may contribute to these abnormalities. The limited data from the single family with the more proximal BP3-BP4 deletion suggest this deletion may have little clinical significance. Patients with duplications of the BP3-BP4-BP5 region did not share a recognizable phenotype, but psychiatric disease was noted in two of four patients. Overall, our findings broaden the phenotypic spectrum associated with 15q13.3 deletions and suggest that, in some individuals, deletion of 15q13.3 is not sufficient to cause disease. The existence of microdeletion syndromes, associated with an unpredictable and variable phenotypic outcome, will pose the clinician with diagnostic difficulties and challenge the commonly used paradigm in the diagnostic setting that aberrations inherited from a phenotypically normal parent are usually without clinical consequences.
252 citations
Authors
Showing all 8248 results
Name | H-index | Papers | Citations |
---|---|---|---|
Andrei Shleifer | 171 | 514 | 271880 |
Paul Elliott | 153 | 773 | 103839 |
Bert Brunekreef | 124 | 806 | 81938 |
Philippe Aghion | 122 | 507 | 73438 |
Anjana Rao | 118 | 337 | 61395 |
Jordi Sunyer | 115 | 798 | 57211 |
Kenneth J. Arrow | 113 | 411 | 111221 |
Xavier Estivill | 110 | 673 | 59568 |
Roderic Guigó | 108 | 304 | 106914 |
Mark J. Nieuwenhuijsen | 107 | 647 | 49080 |
Jordi Alonso | 107 | 523 | 64058 |
Alfonso Valencia | 106 | 542 | 55192 |
Luis Serrano | 105 | 452 | 42515 |
Vadim N. Gladyshev | 102 | 490 | 34148 |
Josep M. Antó | 100 | 493 | 38663 |