32 research outputs found
Techniques d'identification d'entitĂ©s nommĂ©es et de classification non-supervisĂ©e pour des requĂȘtes de recherche web Ă l'aide d'informations contenues dans les pages web visitĂ©es
Le web est maintenant devenu une importante source dâinformation et de divertissement pour un grand nombre de personnes et les techniques pour accĂ©der au contenu dĂ©sirĂ© ne cessent dâĂ©voluer. Par exemple, en plus de la liste de pages web habituelle, certains moteurs de recherche prĂ©sentent maintenant directement, lorsque possible, lâinformation recherchĂ©e par lâusager. Dans ce contexte, lâĂ©tude des requĂȘtes soumises Ă ce type de moteur de recherche devient un outil pouvant aider Ă perfectionner ce genre de systĂšme et ainsi amĂ©liorer lâexpĂ©rience dâutilisation de ses usagers. Dans cette optique, le prĂ©sent document prĂ©sentera certaines techniques qui ont Ă©tĂ© dĂ©veloppĂ©es pour faire lâĂ©tude des requĂȘtes de recherche web soumises Ă un moteur de recherche. En particulier, le travail prĂ©sentĂ© ici sâintĂ©resse Ă deux problĂšmes distincts. Le premier porte sur la classification non-supervisĂ©e dâun ensemble de requĂȘtes de recherche web dans le but de parvenir Ă regrouper ensemble les requĂȘtes traitant dâun mĂȘme sujet. Le deuxiĂšme problĂšme porte quant Ă lui sur la dĂ©tection non-supervisĂ©e des entitĂ©s nommĂ©es contenues dans un ensemble de requĂȘtes qui ont Ă©tĂ© soumises Ă un moteur de recherche. Les deux techniques proposĂ©es utilisent lâinformation supplĂ©mentaire apportĂ©e par la connaissance des pages web qui ont Ă©tĂ© visitĂ©es par les utilisateurs ayant Ă©mis les requĂȘtes Ă©tudiĂ©es
Model falsification diagnosis and sensor placement for leak detection in pressurized pipe networks
Pressurized pipe networks used for fresh-water distribution can take advantage of recent advances in sensing technologies and data-interpretation to evaluate their performance. In this paper, a leak-detection and a sensor placement methodology are proposed based on leak-scenario falsification. The approach includes modeling and measurement uncertainties during the leak detection process. The performance of the methodology proposed is tested on a full-scale water distribution network using simulated data. Findings indicate that when monitoring the flow velocity for 14 pipes over the entire network (295 pipes) leaks are circumscribed within a few potential locations. The case-study shows that a good detectability is expected for leaks of 50 L/min or more. A study of measurement configurations shows that smaller leak levels could also be detected if additional pipes are instrumented. (C) 2013 Elsevier Ltd. All rights reserved
Widespread anti-CRISPR proteins in virulent bacteriophages inhibit a range of Cas9 proteins
International audienceCRISPR-Cas systems are bacterial anti-viral systems, and bacterial viruses (bacteriophages, phages) can carry anti-CRISPR (Acr) proteins to evade that immunity. Acrs can also fine-tune the activity of CRISPR-based genome-editing tools. While Acrs are prevalent in phages capable of lying dormant in a CRISPR-carrying host, their orthologs have been observed only infrequently in virulent phages. Here we identify AcrIIA6, an Acr encoded in 33% of virulent Streptococcus thermophilus phage genomes. The X-ray structure of AcrIIA6 displays some features unique to this Acr family. We compare the activity of AcrIIA6 to those of other Acrs, including AcrIIA5 (also from S. thermophilus phages), and characterize their effectiveness against a range of CRISPR-Cas systems. Finally, we demonstrate that both Acr families from S. thermophilus phages inhibit Cas9-mediated genome editing of human cells
Innovation et développement dans les systÚmes agricoles et alimentaires
Lâinnovation est souvent prĂ©sentĂ©e comme lâun des principaux leviers pour promouvoir un dĂ©veloppement plus durable et plus inclusif. Dans les domaines de lâagriculture et de lâalimentation, lâinnovation est marquĂ©e par des spĂ©cificitĂ©s liĂ©es Ă sa relation Ă la nature, mais aussi Ă la grande diversitĂ© dâacteurs concernĂ©s, depuis les agriculteurs jusquâaux consommateurs, en passant par les services de recherche et de dĂ©veloppement. Lâinnovation Ă©merge des interactions entre ces acteurs, qui mobilisent des ressources et produisent des connaissances dans des dispositifs collaboratifs, afin de gĂ©nĂ©rer des changements. Elle recouvre des domaines aussi variĂ©s que les pratiques de production, lâorganisation des marchĂ©s, ou les pratiques alimentaires. Lâinnovation est reliĂ©e aux grands enjeux de dĂ©veloppement : innovation agro-Ă©cologique, innovation sociale, innovation territoriale, etc. Cet ouvrage porte un regard sur lâinnovation dans les systĂšmes agricoles et alimentaires. Il met un accent particulier sur lâaccompagnement de lâinnovation, en interrogeant les mĂ©thodes et les organisations, et sur lâĂ©valuation de lâinnovation au regard de diffĂ©rents critĂšres. Il sâappuie sur des rĂ©flexions portĂ©es par diffĂ©rentes disciplines scientifiques, sur des travaux de terrain conduits tant en France que dans de nombreux pays du Sud, et enfin sur les expĂ©riences acquises en accompagnant des acteurs qui innovent. Il combine des synthĂšses sur lâinnovation et des Ă©tudes de cas emblĂ©matiques pour illustrer les propos. Lâouvrage est destinĂ© aux enseignants, professionnels, Ă©tudiants et chercheurs
Therapeutic targeting of cathepsin C::from pathophysiology to treatment
Cathepsin C (CatC) is a highly conserved tetrameric lysosomal cysteine dipeptidyl aminopeptidase. The best characterized physiological function of CatC is the activation of pro-inflammatory granule-associated serine proteases. These proteases are synthesized as inactive zymogens containing an N-terminal pro-dipeptide, which maintains the zymogen in its inactive conformation and prevents premature activation, which is potentially toxic to the cell. The activation of serine protease zymogens occurs through cleavage of the N-terminal dipeptide by CatC during cell maturation in the bone marrow. In vivo data suggest that pharmacological inhibition of pro-inflammatory serine proteases would suppress or attenuate deleterious effects of inflammatory/auto-immune disorders mediated by these proteases. The pathological deficiency in CatC is associated with Papillon-LefĂšvre syndrome. The patients however do not present marked immunodeficiency despite the absence of active serine proteases in immune defense cells. Hence, the transitory pharmacological blockade of CatC activity in the precursor cells of the bone marrow may represent an attractive therapeutic strategy to regulate activity of serine proteases in inflammatory and immunologic conditions. A variety of CatC inhibitors have been developed both by pharmaceutical companies and academic investigators, some of which are currently being employed and evaluated in preclinical/clinical trials
Techniques d'identification d'entitĂ©s nommĂ©es et de classification non-supervisĂ©e pour des requĂȘtes de recherche web Ă l'aide d'informations contenues dans les pages web visitĂ©es
Le web est maintenant devenu une importante source dâinformation et de divertissement pour un grand nombre de personnes et les techniques pour accĂ©der au contenu dĂ©sirĂ© ne cessent dâĂ©voluer. Par exemple, en plus de la liste de pages web habituelle, certains moteurs de recherche prĂ©sentent maintenant directement, lorsque possible, lâinformation recherchĂ©e par lâusager. Dans ce contexte, lâĂ©tude des requĂȘtes soumises Ă ce type de moteur de recherche devient un outil pouvant aider Ă perfectionner ce genre de systĂšme et ainsi amĂ©liorer lâexpĂ©rience dâutilisation de ses usagers. Dans cette optique, le prĂ©sent document prĂ©sentera certaines techniques qui ont Ă©tĂ© dĂ©veloppĂ©es pour faire lâĂ©tude des requĂȘtes de recherche web soumises Ă un moteur de recherche. En particulier, le travail prĂ©sentĂ© ici sâintĂ©resse Ă deux problĂšmes distincts. Le premier porte sur la classification non-supervisĂ©e dâun ensemble de requĂȘtes de recherche web dans le but de parvenir Ă regrouper ensemble les requĂȘtes traitant dâun mĂȘme sujet. Le deuxiĂšme problĂšme porte quant Ă lui sur la dĂ©tection non-supervisĂ©e des entitĂ©s nommĂ©es contenues dans un ensemble de requĂȘtes qui ont Ă©tĂ© soumises Ă un moteur de recherche. Les deux techniques proposĂ©es utilisent lâinformation supplĂ©mentaire apportĂ©e par la connaissance des pages web qui ont Ă©tĂ© visitĂ©es par les utilisateurs ayant Ă©mis les requĂȘtes Ă©tudiĂ©es
Effect of fermented milks on humoral immune response in mice
Eight groups of 20 CD-1 mice were fed for eight days with UHT milk
fermented by one of the following bacteria: Bifidobacterium Iongum,
Lactobacillus acidophilus, L. delbrueckii spp. bulgaricus, L. casei
spp.rhamnosus, L. helveticus, Lactococcus lactis spp. cremoris, Lactococcus lactis spp. lactis, Streptococcus salivarius spp. thermophilus. No
significant differences were observed in the serum IgG and IgA level, nor in the
bronchoalveolar lgG level. Only mice fed milk fermented with L. delbrueckii
spp. bulgaricus showed a significant increase (P < 0.05) in their bronchoalveolar lgA level after eight days. The extent of proteolysis of the fermented
milks was not correlated with the bronchoalveolar lgA level
Structural Insights into Lactococcal Siphophage p2 Baseplate Activation Mechanism
International audienceVirulent phages infecting L. lactis, an industry-relevant bacterium, pose a significant risk to the quality of the fermented milk products. Phages of the Skunavirus genus are by far the most isolated lactococcal phages in the cheese environments and phage p2 is the model siphophage for this viral genus. The baseplate of phage p2, which is used to recognize its host, was previously shown to display two conformations by X-ray crystallography, a rested state and an activated state ready to bind to the host. The baseplate became only activated and opened in the presence of Ca 2+. However, such an activated state was not previously observed in the virion. Here, using nanobodies binding to the baseplate, we report on the negative staining electron microscopy structure of the activated form of the baseplate directly observed in the p2 virion, that is compatible with the activated baseplate crystal structure. Analyses of this new structure also established the presence of a second distal tail (Dit) hexamer as a component of the baseplate, the topology of which differs largely from the first one. We also observed an uncoupling between the baseplate activation and the tail tip protein (Tal) opening, suggesting an infection mechanism more complex than previously expected