Comparing System-response Retrieval Models for Open-domain and Casual Conversational Agent

International audienceThis paper studies corpus-based process to select a system-response usable both in chatterbot or as a fallback strategy. It presents, evaluates and compares two selection methods that retrieve and adapt a system-response from the OpenSubtitles2016 corpus given a human-utterance. A corpus of 800 annotated pairs is constituted. Evaluation consists in objective metrics and subjective annotation based on the validity schema proposed in the RE-WOCHAT shared task. Our study indicates that the task of assessing the validity of a system-response given a human-utterance is subjective to an important extent, and is thus a difficult task. Comparisons show that the selection method based on word embedding performs objectively better than the one based on TF-IDF in terms of response variety and response length

Association between psoas abscess and prosthetic hip infection: a case-control study

Background and purpose The relationship between prosthetic hip infection and a psoas abscess is poorly documented. We determined the frequency of prosthetic hip infections associated with psoas abscesses and identified their determinants

Secretion of Hepatitis C Virus Envelope Glycoproteins Depends on Assembly of Apolipoprotein B Positive Lipoproteins

The density of circulating hepatitis C virus (HCV) particles in the blood of chronically infected patients is very heterogeneous. The very low density of some particles has been attributed to an association of the virus with apolipoprotein B (apoB) positive and triglyceride rich lipoproteins (TRL) likely resulting in hybrid lipoproteins known as lipo-viro-particles (LVP) containing the viral envelope glycoproteins E1 and E2, capsid and viral RNA. The specific infectivity of these particles has been shown to be higher than the infectivity of particles of higher density. The nature of the association of HCV particles with lipoproteins remains elusive and the role of apolipoproteins in the synthesis and assembly of the viral particles is unknown. The human intestinal Caco-2 cell line differentiates in vitro into polarized and apoB secreting cells during asymmetric culture on porous filters. By using this cell culture system, cells stably expressing E1 and E2 secreted the glycoproteins into the basal culture medium after one week of differentiation concomitantly with TRL secretion. Secreted glycoproteins were only detected in apoB containing density fractions. The E1–E2 and apoB containing particles were unique complexes bearing the envelope glycoproteins at their surface since apoB could be co-immunoprecipitated with E2-specific antibodies. Envelope protein secretion was reduced by inhibiting the lipidation of apoB with an inhibitor of the microsomal triglyceride transfer protein. HCV glycoproteins were similarly secreted in association with TRL from the human liver cell line HepG2 but not by Huh-7 and Huh-7.5 hepatoma cells that proved deficient for lipoprotein assembly. These data indicate that HCV envelope glycoproteins have the intrinsic capacity to utilize apoB synthesis and lipoprotein assembly machinery even in the absence of the other HCV proteins. A model for LVP assembly is proposed

La loi sur le contrat d'assurance terrestre. Bilan et perspectives après 20 années d'application

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Conserved Omp85 lid-lock structure and substrate recognition in FhaC

Omp85 proteins mediate translocation of polypeptide substrates across and into cellular membranes. They share a common architecture comprising substrate-interacting POTRA domains, a C-terminal 16-stranded β-barrel pore and two signature motifs located on the inner barrel wall and at the tip of the extended L6 loop. The observation of two distinct conformations of the L6 loop in the available Omp85 structures previously suggested a functional role of conformational changes in L6 in the Omp85 mechanism. Here we present a 2.5 Å resolution structure of a variant of the Omp85 secretion protein FhaC, in which the two signature motifs interact tightly and form the conserved 'lid lock'. Reanalysis of previous structural data shows that L6 adopts the same, conserved resting state position in all available Omp85 structures. The FhaC variant structure further reveals a competitive mechanism for the regulation of substrate binding mediated by the linker to the N-terminal plug helix H1

L'étendue de la garantie dans le temps et les assurances de la responsabilité civile

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Les recours de l'assureur après indemnisation

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