146 research outputs found

    CLAPI, une base de données multimodale pour la parole en interaction : apports et dilemmes

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    Dans cette contribution, nous prĂ©sentons la base CLAPI dĂ©veloppĂ©e au laboratoire ICAR dans le contexte de l’évolution des bases de donnĂ©es de langues parlĂ©es en France au cours des trente derniĂšres annĂ©es. Nous dĂ©taillons les deux composantes de CLAPI, l’archive de corpus de langue parlĂ©e en interaction audio et vidĂ©o enregistrĂ©s dans des situations sociales naturelles variĂ©es, et la plateforme d’outils.L’usage et l’apport de CLAPI sont illustrĂ©s par deux Ă©tudes. L’une dĂ©crit comment la base peut ĂȘtre utilisĂ©e pour des travaux de linguistique interactionnelle intĂ©grant la multimodalitĂ© (« oh lĂ  là ») ; l’autre concerne une recherche combinant donnĂ©es et mĂ©tadonnĂ©es (« trop »). L’article est aussi l’occasion d’un bilan plus gĂ©nĂ©ral. La mise en perspective montre en effet qu’aprĂšs la pĂ©riode des questions est venue celle des dilemmes. La pĂ©riode des questions, choix et dĂ©cisions Ă  toutes sortes de niveaux a accompagnĂ© la mise en place des bases de donnĂ©es. L’expĂ©rience permet maintenant de mesurer leurs indĂ©niables apports en termes non seulement de quantitĂ© de donnĂ©es disponibles (et traitables grĂące aux outils), mais aussi de qualitĂ© (comme consĂ©quence des exigences de standardisation liĂ©es au partage des donnĂ©es). La pĂ©riode des dilemmes nous conduit Ă  nous interroger sur les meilleurs choix Ă  opĂ©rer aujourd’hui dans les relations entre la poursuite des recherches sur des corpus variĂ©s (et parfois sensibles) et les exigences des bases de donnĂ©es ouvertes.In this contribution, we present the development of the CLAPI by the ICAR Lab in the context of the evolution of the databases of spoken languages in France during the last thirty years. We describe the two components of CLAPI, the archive of corpus of spoken languages in interaction, audio and video, recorded in varied naturally-occurring social situations, and the plateform of tools.The use and the support of CLAPI the research are shown out of two studies. One illustrates how the database can be used for working in an interactional linguistic perspective, including multimodality (“oh lĂ  là”); the other concerns a research combining data and metadata (“trop”).The article is also the occasion of a more general assessment. The perspective on the last thirty years shows that after a period of questions came that of dilemmas. The period of questions, choices and decisions at various levels accompanied the implementation of the databases. The experience enables now to measure their undeniable contributions in terms not only of quantity of available data (and possibly dealt with supported by the tools), but also of quality of the data (as a consequence of the requirements of standardization linked to the needs of sharing the data). The period of the dilemmas leads us to wonder about the best choices to be operated today among continuing research on varied corpuses (sometimes delicate) and the requirements of the databases

    Effect of maternal obesity and preconceptional weight loss on male and female offspring metabolism and olfactory performance in mice

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    © 2019 by the authors. Licensee MDPI, Basel, Switzerland. According to the “developmental origins of health and disease” (DOHaD) concept, maternal obesity predisposes the offspring to non-communicable diseases in adulthood. While a preconceptional weight loss (WL) is recommended for obese women, its benefits on the offspring have been poorly addressed. We evaluated whether preconceptional WL was able to reverse the adverse effects of maternal obesity in a mouse model, exhibiting a modification of foetal growth and of the expression of genes encoding epigenetic modifiers in liver and placenta. We tracked metabolic and olfactory behavioural trajectories of offspring born to control, obese or WL mothers. After weaning, the offspring were either put on a control diet (CD) or a high-fat (HFD). After only few weeks of HFD, the offspring developed obesity, metabolic alterations and olfactory impairments, independently of maternal context. However, male offspring born to obese mother gained even more weight under HFD than their counterparts born to lean mothers. Preconceptional WL normalized the offspring metabolic phenotypes but had unexpected effects on olfactory performance: a reduction in olfactory sensitivity, along with a lack of fasting-induced, olfactory-based motivation. Our results confirm the benefits of maternal preconceptional WL for male offspring metabolic health but highlight some possible adverse outcomes on olfactory-based behaviours

    Antibodies elicited in adults by a primary Plasmodium falciparum blood-stage infection recognize different epitopes compared with immune individuals

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    <p>Abstract</p> <p>Background</p> <p>Asexual stage antibody responses following initial <it>Plasmodium falciparum </it>infections in previously healthy adults may inform vaccine development, yet these have not been as intensively studied as they have in populations from malaria-endemic areas.</p> <p>Methods</p> <p>Serum samples were collected over a six-month period from twenty travellers having returned with falciparum malaria. Fourteen of these were malaria-naĂŻve and six had a past history of one to two episodes of malaria. Antibodies to seven asexual stage <it>P. falciparum </it>antigens were measured by ELISA. Invasion inhibitory antibody responses to the 19kDa fragment of merozoite surface protein 1 (MSP1<sub>19</sub>) were determined.</p> <p>Results</p> <p>Short-lived antibody responses were found in the majority of the subjects. While MSP1<sub>19 </sub>antibodies were most common, MSP1 block 2 antibodies were significantly less frequent and recognized conserved domains. Antibodies to MSP2 cross-reacted to the dimorphic allelic families and anti-MSP2 isotypes were not IgG3 skewed as shown previously. MSP1<sub>19 </sub>invasion inhibiting antibodies were present in 9/20 patients. A past history of malaria did not influence the frequency of these short-lived, functional antibodies (p = 0.2, 2-tailed Fisher's exact test).</p> <p>Conclusion</p> <p>Adults infected with <it>P. falciparum </it>for the first time, develop relatively short-lived immune responses that, in the case of MSP1<sub>19</sub>, are functional. Antibodies to the polymorphic antigens studied were particularly directed to allelic family specific, non-repetitive and conserved determinants and were not IgG subclass skewed. These responses are substantially different to those found in malaria immune individuals.</p

    An expanded global inventory of allelic variation in the most extremely polymorphic region of Plasmodium falciparum merozoite surface protein 1 provided by short read sequence data.

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    BACKGROUND: Within Plasmodium falciparum merozoite surface protein 1 (MSP1), the N-terminal block 2 region is a highly polymorphic target of naturally acquired antibody responses. The antigenic diversity is determined by complex repeat sequences as well as non-repeat sequences, grouping into three major allelic types that appear to be maintained within populations by natural selection. Within these major types, many distinct allelic sequences have been described in different studies, but the extent and significance of the diversity remains unresolved. METHODS: To survey the diversity more extensively, block 2 allelic sequences in the msp1 gene were characterized in 2400 P. falciparum infection isolates with whole genome short read sequence data available from the Pf3K project, and compared with the data from previous studies. RESULTS: Mapping the short read sequence data in the 2400 isolates to a reference library of msp1 block 2 allelic sequences yielded 3815 allele scores at the level of major allelic family types, with 46% of isolates containing two or more of these major types. Overall frequencies were similar to those previously reported in other samples with different methods, the K1-like allelic type being most common in Africa, MAD20-like most common in Southeast Asia, and RO33-like being the third most abundant type in each continent. The rare MR type, formed by recombination between MAD20-like and RO33-like alleles, was only seen in Africa and very rarely in the Indian subcontinent but not in Southeast Asia. A combination of mapped short read assembly approaches enabled 1522 complete msp1 block 2 sequences to be determined, among which there were 363 different allele sequences, of which 246 have not been described previously. In these data, the K1-like msp1 block 2 alleles are most diverse and encode 225 distinct amino acid sequences, compared with 123 different MAD20-like, 9 RO33-like and 6 MR type sequences. Within each of the major types, the different allelic sequences show highly skewed geographical distributions, with most of the more common sequences being detected in either Africa or Asia, but not in both. CONCLUSIONS: Allelic sequences of this extremely polymorphic locus have been derived from whole genome short read sequence data by mapping to a reference library followed by assembly of mapped reads. The catalogue of sequence variation has been greatly expanded, so that there are now more than 500 different msp1 block 2 allelic sequences described. This provides an extensive reference for molecular epidemiological genotyping and sequencing studies, and potentially for design of a multi-allelic vaccine

    A proteomic approach based on peptide affinity chromatography, 2-dimensional electrophoresis and mass spectrometry to identify multiprotein complexes interacting with membrane-bound receptors

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    There is accumulating evidence that membrane-bound receptors interact with many intracellular proteins. Multiprotein complexes associated with ionotropic receptors have been extensively characterized, but the identification of proteins interacting with G protein-coupled receptors (GPCRs) has so far only been achieved in a piecemeal fashion, focusing on one or two protein species. We describe a method based on peptide affinity chromatography, two-dimensional electrophoresis, mass spectrometry and immunoblotting to identify the components of multiprotein complexes interacting directly or indirectly with intracellular domains of GPCRs or, more generally, any other membrane-bound receptor. Using this global approach, we have characterized multiprotein complexes that bind to the carboxy-terminal tail of the 5-hydroxytryptamine type 2C receptor and are important for its subcellular localization in CNS cells (BĂ©camel et al., EMBO J., 21(10): 2332, 2002)

    Pre-Clinical Assessment of Novel Multivalent MSP3 Malaria Vaccine Constructs

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    BACKGROUND: MSP3 has been shown to induce protection against malaria in African children. The characterization of a family of Plasmodium falciparum merozoite surface protein 3 (MSP3) antigens sharing a similar structural organization, simultaneously expressed on the merozoite surface and targeted by a cross-reactive network of protective antibodies, is intriguing and offers new perspectives for the development of subunit vaccines against malaria. METHODS: Eight recombinant polyproteins containing carefully selected regions of this family covalently linked in different combinations were all efficiently produced in Escherichia coli. The polyproteins consisted of one monovalent, one bivalent, one trivalent, two tetravalents, one hexavalent construct, and two tetravalents incorporating coiled-coil repeats regions from LSA3 and p27 vaccine candidates. RESULTS: All eight polyproteins induced a strong and homogeneous antibody response in mice of three distinct genotypes, with a dominance of cytophilic IgG subclasses, lasting up to six months after the last immunization. Vaccine-induced antibodies exerted a strong monocyte-mediated in vitro inhibition of P. falciparum growth. Naturally acquired antibodies from individuals living in an endemic area of Senegal recognized the polyproteins with a reactivity mainly constituted of cytophilic IgG subclasses. CONCLUSIONS: Combination of genetically conserved and antigenically related MSP3 proteins provides promising subunit vaccine constructs, with improved features as compared to the first generation construct employed in clinical trials (MSP3-LSP). These multivalent MSP3 vaccine constructs expand the epitope display of MSP3 family proteins, and lead to the efficient induction of a wider range of antibody subclasses, even in genetically different mice. These findings are promising for future immunization of genetically diverse human populations

    A rapid and robust tri-color flow cytometry assay for monitoring malaria parasite development

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    Microscopic examination of Giemsa-stained thin blood smears remains the gold standard method used to quantify and stage malaria parasites. However, this technique is tedious, and requires trained microscopists. We have developed a fast and simple flow cytometry method to quantify and stage, various malaria parasites in red blood cells in whole blood or in vitro cultured Plasmodium falciparum. The parasites were stained with dihydroethidium and Hoechst 33342 or SYBR Green I and leukocytes were identified with an antibody against CD45. Depending on the DNA stains used, samples were analyzed using different models of flow cytometers. This protocol, which does not require any washing steps, allows infected red blood cells to be distinguished from leukocytes, as well as allowing non-infected reticulocytes and normocytes to be identified. It also allows assessing the proportion of parasites at different developmental stages. Lastly, we demonstrate how this technique can be applied to antimalarial drug testing

    Omega-3 Fatty Acids from Fish Oil Lower Anxiety, Improve Cognitive Functions and Reduce Spontaneous Locomotor Activity in a Non-Human Primate

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    Omega-3 (ω3) polyunsaturated fatty acids (PUFA) are major components of brain cells membranes. ω3 PUFA-deficient rodents exhibit severe cognitive impairments (learning, memory) that have been linked to alteration of brain glucose utilization or to changes in neurotransmission processes. ω3 PUFA supplementation has been shown to lower anxiety and to improve several cognitive parameters in rodents, while very few data are available in primates. In humans, little is known about the association between anxiety and ω3 fatty acids supplementation and data are divergent about their impact on cognitive functions. Therefore, the development of nutritional studies in non-human primates is needed to disclose whether a long-term supplementation with long-chain ω3 PUFA has an impact on behavioural and cognitive parameters, differently or not from rodents. We address the hypothesis that ω3 PUFA supplementation could lower anxiety and improve cognitive performances of the Grey Mouse Lemur (Microcebus murinus), a nocturnal Malagasy prosimian primate. Adult male mouse lemurs were fed for 5 months on a control diet or on a diet supplemented with long-chain ω3 PUFA (n = 6 per group). Behavioural, cognitive and motor performances were measured using an open field test to evaluate anxiety, a circular platform test to evaluate reference spatial memory, a spontaneous locomotor activity monitoring and a sensory-motor test. ω3-supplemented animals exhibited lower anxiety level compared to control animals, what was accompanied by better performances in a reference spatial memory task (80% of successful trials vs 35% in controls, p<0.05), while the spontaneous locomotor activity was reduced by 31% in ω3-supplemented animals (p<0.001), a parameter that can be linked with lowered anxiety. The long-term dietary ω3 PUFA supplementation positively impacts on anxiety and cognitive performances in the adult mouse lemur. The supplementation of human food with ω3 fatty acids may represent a valuable dietary strategy to improve behavioural and cognitive functions

    The Potent Respiratory System of Osedax mucofloris (Siboglinidae, Annelida) - A Prerequisite for the Origin of Bone-Eating Osedax?

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    Members of the conspicuous bone-eating genus, Osedax, are widely distributed on whale falls in the Pacific and Atlantic Oceans. These gutless annelids contain endosymbiotic heterotrophic bacteria in a branching root system embedded in the bones of vertebrates, whereas a trunk and anterior palps extend into the surrounding water. The unique life style within a bone environment is challenged by the high bacterial activity on, and within, the bone matrix possibly causing O2 depletion, and build-up of potentially toxic sulphide. We measured the O2 distribution around embedded Osedax and showed that the bone microenvironment is anoxic. Morphological studies showed that ventilation mechanisms in Osedax are restricted to the anterior palps, which are optimized for high O2 uptake by possessing a large surface area, large surface to volume ratio, and short diffusion distances. The blood vascular system comprises large vessels in the trunk, which facilitate an ample supply of oxygenated blood from the anterior crown to a highly vascularised root structure. Respirometry studies of O. mucofloris showed a high O2 consumption that exceeded the average O2 consumption of a broad line of resting annelids without endosymbionts. We regard this combination of features of the respiratory system of O. mucofloris as an adaptation to their unique nutrition strategy with roots embedded in anoxic bones and elevated O2 demand due to aerobic heterotrophic endosymbionts

    A Phase 1 Trial of MSP2-C1, a Blood-Stage Malaria Vaccine Containing 2 Isoforms of MSP2 Formulated with MontanideÂź ISA 720

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    Background: In a previous Phase 1/2b malaria vaccine trial testing the 3D7 isoform of the malaria vaccine candidate Merozoite surface protein 2 (MSP2), parasite densities in children were reduced by 62%. However, breakthrough parasitemias were disproportionately of the alternate dimorphic form of MSP2, the FC27 genotype. We therefore undertook a dose-escalating, double-blinded, placebo-controlled Phase 1 trial in healthy, malaria-naĂŻve adults of MSP2-C1, a vaccine containing recombinant forms of the two families of msp2 alleles, 3D7 and FC27 (EcMSP2-3D7 and EcMSP2-FC27), formulated in equal amounts with MontanideÂź ISA 720 as a water-in-oil emulsion. Methodology/Principal Findings: The trial was designed to include three dose cohorts (10, 40, and 80 ÎŒg), each with twelve subjects receiving the vaccine and three control subjects receiving MontanideÂź ISA 720 adjuvant emulsion alone, in a schedule of three doses at 12-week intervals. Due to unexpected local reactogenicity and concern regarding vaccine stability, the trial was terminated after the second immunisation of the cohort receiving the 40 ÎŒg dose; no subjects received the 80 ÎŒg dose. Immunization induced significant IgG responses to both isoforms of MSP2 in the 10 ÎŒg and 40 ÎŒg dose cohorts, with antibody levels by ELISA higher in the 40 ÎŒg cohort. Vaccine-induced antibodies recognised native protein by Western blots of parasite protein extracts and by immunofluorescence microscopy. Although the induced anti-MSP2 antibodies did not directly inhibit parasite growth in vitro, IgG from the majority of individuals tested caused significant antibody-dependent cellular inhibition (ADCI) of parasite growth. Conclusions/Significance: As the majority of subjects vaccinated with MSP2-C1 developed an antibody responses to both forms of MSP2, and that these antibodies mediated ADCI provide further support for MSP2 as a malaria vaccine candidate. However, in view of the reactogenicity of this formulation, further clinical development of MSP2-C1 will require formulation of MSP2 in an alternative adjuvant. Trial Registration: Australian New Zealand Clinical Trials Registry 12607000552482
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