3,523 research outputs found
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International audienceIn this paper, we present the aim and architecture of our dialogue modeling project. We focus on producing logical representations of questions and answers in dialogue. Our view is to narrow the problem of identifying incomprehension in dialogue to the one of finding logical incoherences in speech acts combinations
Recent and Ancient Signature of Balancing Selection around the S-Locus in Arabidopsis halleri and A. lyrata
Balancing selection can maintain different alleles over long evolutionary times. Beyond this direct effect on the molecular targets of selection, balancing selection is also expected to increase neutral polymorphism in linked genome regions, in inverse proportion to their genetic map distances from the selected sites. The genes controlling plant self-incompatibility are subject to one of the strongest forms of balancing selection, and they show clear signatures of balancing selection. The genome region containing those genes (the S-locus) is generally described as nonrecombining, and the physical size of the region with low recombination has recently been established in a few species. However, the size of the region showing the indirect footprints of selection due to linkage to the S-locus is only roughly known. Here, we improved estimates of this region by surveying synonymous polymorphism and estimating recombination rates at 12 flanking region loci at known physical distances from the S-locus region boundary, in two closely related self-incompatible plants Arabidopsis halleri and A. lyrata. In addition to studying more loci than previous studies and using known physical distances, we simulated an explicit demographic scenario for the divergence between the two species, to evaluate the extent of the genomic region whose diversity departs significantly from neutral expectations. At the closest flanking loci, we detected signatures of both recent and ancient indirect effects of selection on the S-locus flanking genes, finding ancestral polymorphisms shared by both species, as well as an excess of derived mutations private to either species. However, these effects are detected only in a physically small region, suggesting that recombination in the flanking regions is sufficient to quickly break up linkage disequilibrium with the S-locus. Our approach may be useful for distinguishing cases of ancient versus recently evolved balancing selection in other systems
Topological Space Partition for Fast Ray Tracing in Architectural Models
International audienceFast ray-tracing requires an efficient acceleration structure. For architectural environment, the most famous is the cells-and-portals one. Many previous works attempt to automatically construct a good cells-and-portals. We propose a new acceleration structure which extends the classical cells-and-portals. It is automatically extracted from the topological model of a given building. It contains a low number of large volumes, all of them linked into a graph model. The scan of our structure is particularly simple and rapid, using all the topological information available from the topological model. The scan can be done for a single ray, or a wide ray packet. We show in this paper that our structure allows an interactive rendering even for large building models, with direct lighting from some thousands of point lights
Draft Genome Sequence of an International Clonal Lineage 1 Acinetobacter baumannii Strain from Argentina
In the last few years Acinetobacter baumannii has emerged worldwide as an important nosocomial pathogen in medical institutions. Here, we present the draft genome sequence of the international clonal lineage 1 (ICL1) A. baumannii strain A144 that was isolated in a hospital in Buenos Aires City in the year 1997. The strain is susceptible to carbapenems and resistant to trimethoprim and gentamicin.Fil: Vilacoba, Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Déraspe, Maxime. Laval University; CanadáFil: Traglia, German Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Roy, Paul H.. Laval University; CanadáFil: Ramirez, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentina. California State University; Estados UnidosFil: Centron, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin
Visualisation interactive de grands bâtiments
Best paper awardNational audienceLes performances des algorithmes de lancer de rayons sont directement liées à la structure accélératrice utilisée. En ce qui concerne les environnements architecturaux, plusieurs travaux ont précédemment démontré que la structure accélératrice la plus efficace est la structure cellules-et-passages. Dans cet article, nous proposons une nouvelle structure accélératrice qui consiste en une extension des structures cellules-et-passages classiques par une description topologique complète de la scène. La structure de données est décrite par un graphe dont le parcours, utilisant l'ensemble des propriétés topologiques de notre modèle, est particulièrement simple et rapide. Nous montrons dans cet article que notre structure permet un rendu interactif même pour de grands bâtiments composés de plusieurs centaines de pièces meublées en prenant en compte l'éclairage direct de plusieurs milliers de sources lumineuses ponctuelles
Reliable Control through Wireless Networks
submitted paperReliability is one of the biggest challenges when using Wireless Sensor-Actuator Networks in control systems. This paper exploits the transactional guarantees offered by the LINC coordination environment to provide reliability and robustness in wireless control systems. First, LINC transactions were embedded in the mirco-controllers to deal with possible communication errors, faulty devices, and concurrent access to the devices. Then, an active replication mechanism was provided so that the system can be correctly recovered from hardware and communication failures. A case study of a ball and plate problem is detailed. The plate is lift up and down by three motors. Each motor is controlled by a micro-controller communicating in wireless with the system controller
Characterization of a second open reading frame in genome segment 10 of bluetongue virus
Viruses have often evolved overlapping reading frames in order to maximise their coding capacity. Until recently, the segmented double-stranded (ds) RNA genome of viruses of the Orbivirus genus was thought to be monocistronic but the identification of the bluetongue virus (BTV) NS4 protein changed this assumption. A small open reading frame (ORF) in segment 10, overlapping the NS3 ORF in the +1 position that is maintained in more than 300 strains of the 26 different BTV serotypes and in more of 200 strains of the phylogenetically related African horse sickness (AHSV). In BTV, this ORF (named S10-ORF2 in this study) encodes a putative protein of 50-59 amino acid residues in length and appears to be under a strong positive selection. HA- or GFP-tagged versions of S10-ORF2 expressed from transfected plasmids localised within the nucleoli of transfected cells unless a putative nucleolar localisation signal was mutated S10-ORF2 inhibited gene expression, but not RNA translation, in transient transfection reporter assays. In both mammalian and insect cells, BTV S10-ORF2 deletion mutants (BTV8ΔS10-ORF2) displayed similar replication kinetics to wild type virus. In vivo, S10-ORF2 deletion mutants were pathogenic in mouse models of disease. Although further evidence is required for S10-ORF2 expression during infection, the data presented provide an initial characterisation of this open reading frame
Clinical, anatomical and pathological features in the three variants of primary progressive aphasia : a review
Primary progressive aphasias (PPA) are neurodegenerative diseases clinically
characterized by an early and relatively isolated language impairment. Three main
clinical variants, namely the nonfluent/agrammatic variant (nfvPPA), the semantic
variant (svPPA), and the logopenic variant (lvPPA) have been described, each with
specific linguistic/cognitive deficits, corresponding anatomical and most probable
pathological features. Since the discovery and the development of diagnostic criteria for
the PPA variants by the experts in the field, significant progress has been made in the
understanding of these diseases. This review aims to provide an overview of the literature
on each of the PPA variant in terms of their clinical, anatomical and pathological features,
with a specific focus on recent findings. In terms of clinical advancements, recent
studies have allowed a better characterization and differentiation of PPA patients based
on both their linguistic and non-linguistic profiles. In terms of neuroimaging, techniques
such as diffusion imaging and resting-state fMRI have allowed a deeper understanding
of the impact of PPA on structural and functional connectivity alterations beyond the
well-defined pattern of regional gray matter atrophy. Finally, in terms of pathology,
despite significant advances, clinico-pathological correspondence in PPA remains far
from absolute. Nonetheless, the improved characterization of PPA has the potential to
have a positive impact on the management of patients. Improved reliability of diagnoses
and the development of reliable in vivo biomarkers for underlying neuropathology will
also be increasingly important in the future as trials for etiology-specific treatments
become available
Interregional migration of human creative capital:The case of "Bohemian graduates"
The human capital endowment has long been perceived to be of paramount importance to regional growth and development. In recent years, there also has been a widely held belief that creativity, going hand in hand with innovation and knowledge creation, readily translates into regional competitiveness. Attracting quality human capital and cultivating creative industry/class have been given an unprecedented level of significance in regional policies. As a result of this, understanding the factors determining the migration behaviour of graduates – and especially graduates in creative disciplines – has clear implications for policy makers. In addressing these issues and advancing our understanding of the relationship between creativity and mobility in human capital, this study provides the first empirical analysis of the role played by graduates' subject background (i.e. creative vs. non-creative subjects) in influencing their migration choice in the UK. Our data employed in this paper primarily draw on the Destinations of Lea-vers from Higher Education Survey (DLHE) 2006/2007, collected by the UK's Higher Education Statistic Agency. Graduates are classified into five migration categories based on their migration choices from domicile to university and then onto workplace. Our results show that graduates from disciplines such as business/management and more importantly engineering/technology are more migratory and more likely to be repeat migrants and land higher paid jobs, while graduates from creative arts, education or law are less mobile and, on average, earn less
Atrophy in Alzheimer’s disease and semantic dementia : an ALE meta-analysis of voxel-based morphometry studies
Background/Objectives: Alzheimer’s disease (AD) and semantic dementia (SD) have distinct episodic memory profiles
despite the hippocampal atrophy that characterizes both diseases. The aim of this study was to delineate the pattern of gray
matter (GM) atrophy associated with AD and SD as well as any differences in these patterns by pooling together the results
of previous voxel-based morphometry (VBM) studies.
Methods/Overview: We conducted a meta-analysis of VBM studies that investigated GM atrophy in AD patients versus
controls (CTRLs) and in SD patients versus CTRLs using the activation likelihood estimation (ALE) approach. Our systematic
review allowed us to identify 63 VBM studies.
Results: The results confirmed that in addition to the classical cortical pattern of atrophy involving posterior medial and lateral
regions in AD and the anterior lateral temporal lobes in SD, both AD and SD patients are characterized by bilateral atrophy of
the hippocampus. Furthermore, in SD, the hippocampal atrophy was limited to the anterior portion of the hippocampus, while
in AD, both the anterior and posterior parts of the hippocampus exhibited atrophy. When we compared the foci identified in
the studies that compared AD patients versus CTRLs with those identified in the studies that compared SD patients versus
CTRLs, we observed that the atrophy in the posterior hippocampus and precuneus was more severe in AD.
Conclusion: These results support theories that propose that the deficits observed in AD result from damage to the episodic
memory network, which involves the posterior hippocampus and posterior medial brain regions. However, sparing of the
posterior hippocampus in SD could explain the absence of episodic memory deficits in this population
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