Quel discours de « la » science l’hétérogénéité sémiotique des médias construit-elle ?

Le corpus discursif examiné ici est divers: articles de la presse écrite, caractérisés par la co-présence de textes iconiques et verbaux, émissions radiophoniques, où seul fonctionne le texte oral, émissions télévisées, où s’articulent images mobiles et messages linguistiques oraux, parfois accompagnés d’inserts écrits. Ce qui réunit ces fragments discursifs différents est double, puisque référentiel – ils parlent tous d’objets scientifiques en relation avec la vie quotidienne – et méthodologique: c’est leur hétérogénéité sémiotique, dans ce qu’elle présente de variations mais aussi de données communes, qui est étudiée. L’analyse permet de poser des hypothèses concernant le mode de construction du discours scientifique dans ces médias.What is “the” scientific discourse constructed by the media’s semiotic heterogeneity?The discursive data examined here is varied: newspaper articles, characterized by the co-presence of iconic and verbal texts; radio broadcasts, which are entirely based on oral texts; television programs, where mobile images and oral linguistic messages are combined, occasionally accompanied by written inserts. What reunites these different discursive fragments is dual, because it is referential –they all speak of scientific objects in relation to daily life  and methodological  it is their semiotic heterogeneity, which present variations but also similarities, which is studied. The analysis should allow the posing of hypotheses, to be verified on a larger amount of data, concerning the mode by which the scientific discourse in these medias is constructed

Quel discours de « la » science l’hétérogénéité sémiotique des médias construit-elle ?

Le corpus discursif examiné ici est divers: articles de la presse écrite, caractérisés par la co-présence de textes iconiques et verbaux, émissions radiophoniques, où seul fonctionne le texte oral, émissions télévisées, où s’articulent images mobiles et messages linguistiques oraux, parfois accompagnés d’inserts écrits. Ce qui réunit ces fragments discursifs différents est double, puisque référentiel – ils parlent tous d’objets scientifiques en relation avec la vie quotidienne – et méthodologique: c’est leur hétérogénéité sémiotique, dans ce qu’elle présente de variations mais aussi de données communes, qui est étudiée. L’analyse permet de poser des hypothèses concernant le mode de construction du discours scientifique dans ces médias.What is “the” scientific discourse constructed by the media’s semiotic heterogeneity?The discursive data examined here is varied: newspaper articles, characterized by the co-presence of iconic and verbal texts; radio broadcasts, which are entirely based on oral texts; television programs, where mobile images and oral linguistic messages are combined, occasionally accompanied by written inserts. What reunites these different discursive fragments is dual, because it is referential –they all speak of scientific objects in relation to daily life  and methodological  it is their semiotic heterogeneity, which present variations but also similarities, which is studied. The analysis should allow the posing of hypotheses, to be verified on a larger amount of data, concerning the mode by which the scientific discourse in these medias is constructed

Pan-HA antibodies for influenza detection and quantification

The influenza virus imposes a heavy burden for society in terms of health and economy. Influenza is an elusive enveloped virus due to antigenic shift and drift of two surface proteins: neuraminidase (NA) and hemagglutinin (HA). As a result, new strains emerge every year which require seasonal vaccination for protection. Furthermore, large vaccine quantities are urgently needed in case of pandemics. Theoretically, vaccines against a new strain can be manufactured in as little as three weeks with certain platforms and technologies. However, vaccine quantification and release are still relying on the use of the Single Radial Immunodiffusion (SRID) assay using a strain-specific antibody to calculate HA concentration. This is a major limitation because it can take up to three months to generate the reagents necessary to run the SRID assay, including the strain-specific antibody. Hence, one of the major hurdles in the process of influenza vaccine production is the quantification of HA which is critical to establish proper dosing. To circumvent the need for strain-specific antibodies, we have produced two monoclonal antibodies (F211-11H12-3 and F211-10A9-2) against a highly conserved peptide sequence found within the HA molecule (1). Multiple strains belonging to 13 different influenza A subtypes, as well as 6 strains belonging to B lineages were detected by Western blot and dot blot. Overall, mAb F211-11H12-3 recognizes preferentially influenza A subtype 1, while the mAb F211-10A9-2 has a higher affinity for influenza A subtype 2. Therefore, all strains tested could be detected when both mAb are combined and used as a cocktail. Next, we performed quantitative dot blots by generating a standard curve ranging from 160ng/ml to 20µg/ml HA. This method is simple, easy to implement and highly reproducible. In-process samples as well as purified material can be quantified by dot blot after denaturation with urea. Even though the SRID is the only assay approved by regulatory agencies, quantitative dot blots can be used during manufacturing to optimize and monitor the production process. Finally, ELISA is widely used for quantification and preliminary data demonstrates that samples can be quantified with the pan-HA mAbs. In conclusion, a pan-HA antibody cocktail was generated against a highly conserved peptide sequence of influenza. Viruses produced in eggs and mammalian cells from 40 different strains were detected by Western blot. Reproducible quantification was achieved by dot blot using the two mAbs and an appropriate calibrating standard. The combination of pan-HA antibodies with an immunoassay such as the dot blot assay could accelerate process development and help establish new generation quantification methods for influenza. As the field is looking for flexible and versatile solutions to shift away from the SRID assay and strain-specific antibodies, the development of broad-spectrum antibodies offers a long-awaited alternative. 1) Chun et al, Universal antibodies and their applications to the quantitative determination of virtually all subtypes of the influenza A viral hemagglutinins, Vaccine (26), pp 6068-6076, 2008

Estimating Extracellular Fluid Volume in Healthy Individuals: Evaluation of Existing Formulae and Development of a New Equation

peer reviewedIntroduction: Several clinical settings require an accurate estimation of the physiologically expected extracellular fluid volume (ECFV). We aimed to analyze the performances of existing ECFV-estimating equations and to develop a new equation. Methods: The performances of 11 ECFV-estimating equations were analyzed in 228 healthy kidney donor candidates (Bichat Hospital, Paris, France) who underwent ECFV measurement using the distribution volume of 51Cr-labeled EDTA (51Cr-EDTA). An equation was developed using a penalized linear modeling approach (elastic net regression) and externally (Tenon Hospital, Paris, France, N = 142) validated. Results: Participants from Bichat (mean age 45.2 ± 12.0 years, 43.0% men) and Tenon (47.8 ± 10.3 years, 29.6% men) hospitals had a mean measured ECFV of 15.4 ± 2.8 l and 15.1 ± 2.1 l, respectively. Available ECFV-estimating formulae have highly variable precision and accuracy. The new equation incorporating body weight, height, sex, and age had better precision and accuracy than all other equations in the external validation cohort, with a median bias of −0.20 (95% CI: −0.35 to −0.05) l versus −2.63 (−2.87 to −2.42) l to −0.57 (− 0.83 to −0.40) l and 0.21 (0.12 to 0.43) l to 2.89 (2.65 to 3.11) l, for underestimating and overestimating equations, respectively, an interquartile range for the bias of 0.88 (0.70 to 1.08) l versus 0.91 (0.71 to 1.20) l to 1.93 (1.67 to 2.25) l, and an accuracy within 10% of 90.9% (83.8 to 94.4) versus 88.0% (81.0 to 92.3) to 8.5% (4.2 to 13.4). These results were consistent across subgroups defined by sex, body mass index (BMI), body surface area (BSA), age, and ethnicity. Conclusion: We developed and validated a new equation to estimate the individual reference value of ECFV, which is easily usable in clinical practice. Further validation in cohorts including individuals of extreme age and corpulence remains needed

Autophagy discriminates between Alix and ESCRTs.

International audienceAlix and ESCRT proteins are required for membrane fission during viral budding and egress and during the abscission stage of cytokinesis. These common roles have suggested that Alix functions as an ESCRT protein, a conclusion challenged by the finding that unlike ESCRTs, which control the formation of multivesicular endosomes, Alix does not influence the degradation of the EGF receptor. We previously showed that Alix controls neuronal death by an unknown mechanism, but dependent on its interaction with ESCRT proteins. Since then, numerous reports have shown that ESCRTs participate in macroautophagy. Given the direct interaction between ESCRTs and Alix, together with the known contribution of autophagy to cell death, it was hypothesized that Alix controls autophagy and thereby cell death. Our recent published results show that this is not the case. ESCRT protein activity therefore needs Alix for viral budding and cytokinesis but not for autophagy. The function of ESCRT can thus be clearly be disconnected from that of Alix

ROLE DES PROTEINES G HETEROTRIMERIQUES ET DES PHOSPHOINOSITIDES 3 PHOSPHATE DANS LE CONTROLE DE LA MACRO AUTOPHAGIE

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Autophagy discriminates between Alix and ESCRTs.

International audienceAlix and ESCRT proteins are required for membrane fission during viral budding and egress and during the abscission stage of cytokinesis. These common roles have suggested that Alix functions as an ESCRT protein, a conclusion challenged by the finding that unlike ESCRTs, which control the formation of multivesicular endosomes, Alix does not influence the degradation of the EGF receptor. We previously showed that Alix controls neuronal death by an unknown mechanism, but dependent on its interaction with ESCRT proteins. Since then, numerous reports have shown that ESCRTs participate in macroautophagy. Given the direct interaction between ESCRTs and Alix, together with the known contribution of autophagy to cell death, it was hypothesized that Alix controls autophagy and thereby cell death. Our recent published results show that this is not the case. ESCRT protein activity therefore needs Alix for viral budding and cytokinesis but not for autophagy. The function of ESCRT can thus be clearly be disconnected from that of Alix