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Dans le cadre de la politique d’intégration, l’État français impose aux étrangers l’apprentissage de la langue nationale, et met en place des formations gratuites. L’encadrement serré de celles assurées par des formateurs professionnels au sein des marchés publics de l’Office français de l’immigration et de l’intégration a fait l’objet de recherches récentes (Mercier, 2020; Vadot, 2022). Mais le rôle des bénévoles dans cette politique reste peu étudié. A partir d’une enquête ethnographique menée dans une association et auprès d’agents de préfecture, cet article analyse les conséquences du système de subvention (l’appel à projets) sur les pratiques de formation. Malgré certaines adaptations, voire résistances, le travail bénévole est largement contraint par les prescriptions des pouvoirs publics, et l’obligation d’apprendre le français. En particulier, les petites associations apparaissent comme lieu de relégation des personnes peu ou pas scolarisées, prises dans une « trappe de l’analphabétisme. »

Recirculation of solid digestate through digesters has been demonstrated to be a potential simple strategy to increase continuous stirred-tank reactor biogas plant efficiency. This study extended this earlier work and investigated solid digestate post-treatment using liquid isolated ligninolytic aerobic consortia in order to increase methane recovery during the recirculation. Based on sampling in several natural environments, an enrichment and selection method was implemented using a Lab-scale Automated and Multiplexed (an)Aerobic Chemostat system to generate ligninolytic aerobic consortia. Then, obtained consortia were further cultivated under liquid form in bottles. Chitinophagia bacteria and Sordariomycetes fungi were the two dominant classes of microorganisms enriched through these steps. Finally, these consortia where mixed with the solid digestate before a short-term aerobic post-treatment. However, consortia addition did not increase the efficiency of aerobic post-treatment of solid digestate and lower methane yields were obtained in comparison to the untreated control. The main reason identified is the respiration of easily degradable fractions (e.g., sugars, proteins, amorphous cellulose) by the selected consortia. Thus, this paper highlights the difficulties of constraining microbial consortia to sole ligninolytic activities on complex feedstock, such as solid digestate, that does not only contain lignocellulosic structures.

This study aimed to develop sex reversal procedures targeting the embryonic period as tools to study the early steps of sex differentiation in Nile tilapia with XX, XY, and YY sexual genotypes. XX eggs were exposed to masculinizing treatments with androgens (17α-methyltestosterone, 11-ketotestosterone) or aromatase inhibitor (Fadrozole), whereas XY and YY eggs were subjected to feminizing treatments with estrogen analog (17α-ethynylestradiol). All treatments consisted of a single or double 4-hr immersion applied between 1 and 36 hour post-fertilization (hpf). Concentrations of active substances were 1000 or 2000 μg l(-1) in XX and XY, and 2000 or 6500 μg l(-1) in YY. Masculinizing treatments of XX embryos achieved a maximal sex reversal rate of 10% with an exposure at 24 hpf to 1000 μg l(-1) of 11-ketotestosterone or to 2000 μg l(-1) of Fadrozole. Feminization of XY embryos was more efficient and induced up to 91% sex reversal with an exposure to 2000 μg l(-1) of 17α-ethynylestradiol. Interestingly, similar treatments failed to reverse YY fish to females, suggesting either that a sex determinant linked to the Y chromosome prevents the female pathway when present in two copies, or that a gene present on the X chromosome is needed for the development of a female phenotype., (© 2014 Wiley Periodicals, Inc.)