a b s t r a c tThe aim of this study was to develop an in vitro embryo culture medium without either fetal calf serum or BSA, using various growth factors and cytokines (GFs-CYKs; IGF-I, IGF-II, bFGF, LIF, GM-CSF, TGF-b1, and PDGF-BB), and other molecules with surfactant and embryotrophic properties, such as recombinant albumin (RA) and hyaluronan (HA). The first part of the study was dedicated to define the best combination of GFs-CYKs þ RA þ HA for optimal embryonic development. Next, we compared development rates and embryo quality (inner cell mass [ICM]-to-total cell number [TCN] ratio), and postthaw survival and hatching rates using this synthetic medium (T1) and a control medium: synthetic oviduct fluid þ BSA þ ITS (insulin, transferrin, and selenium). The blastocyst rates were significantly higher with T1 than those with the control at 7 and 8 days after fertilization. There was no significant difference in TCN or the ICM/TCN ratio between the two treatments. Survival and hatching rates 48 hours after thawing were similar for both treatments. Finally, nine embryo transfers were conducted using fresh and previously frozen Day-7 blastocysts to evaluate the in vivo viability of embryos produced in this synthetic medium; four gestations were obtained from six fresh embryos and one gestation from three frozen embryos. In conclusion, the fetal calf serum and BSA-free medium, supplemented with GFs-CYKs þ RA þ HA, improved embryo development and gave comparable ICM/TCN ratios and postthaw survival rates to the control with BSA. Fresh and frozen embryos produced in this medium are viable for embryo transfer. This fully synthetic method of embryo culture is a useful means of reducing the risk of disease transmission via embryo transfer.
International audienceL'acquisition des liaisons est bien documentée et a donné lieu à plusieurs théorisations, dont un modèle basé sur l'usage, essentiellement étayé sur des données expérimentales recueillies en contexte déterminant-nom. Notre but est d'examiner si ce modèle est généralisable à la liaison après les clitiques verbaux, deuxième grand contexte de liaison catégorique. Nous observons les productions de 205 enfants âgés de 3 à 6 ans recueillies dans le contexte de tâches expérimentales. L’étude permet de poser des repères sur l'acquisition de la liaison préverbale et de la comparer à la liaison prénominale
le langage (LRL), EA 999. damien chabanal, loic liégeois et thierry chanier 66 schemas. Secondly, we would like to show how the analysis of parentalchild interactions collected in natural everyday situations challenges the mere phonological analysis of the acquisition of phonological variation, and especially of schwa elision in monosyllabic words.
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