"Ici, on ne se parle pas, on se tue !" : échanges à la sortie du collège en Seine-Saint-Denis

National audienceLa conversation reproduite dans cet article a lieu en 2003, à la sortie du collège, dans une cité d’habitat social de Seine-Saint-Denis. Les 11200 habitants de cette cité, en grande majorité d’origine étrangère, appartiennent à 60 nationalités différentes. Ils constituent une population de plus en plus précaire,issue de façon croissante d’Afrique subsaharienne. 38 % des jeunes de 15-24 ans sont sans diplôme en 1999 (contre 20 % en France métropolitaine) et leur taux de chômage est proche de 50 % (contre 26 % en France métropolitaine)

Inter-formation dans le cadre d'un partenariat éducatif : exemple dans une Zus de Loire Atlantique

National audienc

Inter-formation dans le cadre d’un partenariat éducatif

Cet article présente une expérience réussie de partenariat entre professionnels de l’éducation, en particulier entre des enseignants et des éducateurs de prévention, dans une Zone Urbaine Sensible et son collège. L’histoire de ce dispositif, mis en œuvre pour faire réussir tous les élèves, est d’abord développée. Puis, les conditions qui lui ont permis de durer plusieurs années suivies de celles qui ont conduit à son interruption sont ensuite mises en évidence. Le caractère exceptionnel et la fragilité d’une telle construction collective sont ainsi montrés, rappelant que, d’une façon générale, les professionnels de terrain manquent d’un soutien institutionnel en rapport avec l’ampleur des problèmes qu’ils ont à résoudre.This paper describes a successful experiment of partnership among educational professionals, namely between teachers and street educators, in a junior high-school of an underprivileged urban area. First, the scheme which was implemented to drive all pupils to success is firstly exposed. Secondly, we shed the light on the conditions which allowed the scheme to last several years and those that let it to its termination. The exceptional nature of such a collective endeavour and its fragility are pointed out. Overall, the article highlights that professionals do not benefit from enough institutional support for handling the problems they face.Este artículo presenta una experiencia exitosa de cooperación entre profesionales de la educación, en particular entre profesores y educadores de prevención, en una zona urbana sensible y su colegio. En primer lugar, se desarrolla la historia de este dispositivo puesto en marcha para ayudar al éxito de todos los alumnos. Posteriormente, se ponen de manifiesto las condiciones que han permitido que dure varios años y aquellas que han llevado a su interrupción. Se muestra el carácter excepcional y la fragilidad de un dispositivo colectivo de este tipo, recordando que, de manera general, los profesionales especialistas carecen de un apoyo institucional en relación con la importancia de los problemas que han de resolver

Inter-formation dans le cadre d’un partenariat éducatif

Cet article présente une expérience réussie de partenariat entre professionnels de l’éducation, en particulier entre des enseignants et des éducateurs de prévention, dans une Zone Urbaine Sensible et son collège. L’histoire de ce dispositif, mis en œuvre pour faire réussir tous les élèves, est d’abord développée. Puis, les conditions qui lui ont permis de durer plusieurs années suivies de celles qui ont conduit à son interruption sont ensuite mises en évidence. Le caractère exceptionnel et la fragilité d’une telle construction collective sont ainsi montrés, rappelant que, d’une façon générale, les professionnels de terrain manquent d’un soutien institutionnel en rapport avec l’ampleur des problèmes qu’ils ont à résoudre.This paper describes a successful experiment of partnership among educational professionals, namely between teachers and street educators, in a junior high-school of an underprivileged urban area. First, the scheme which was implemented to drive all pupils to success is firstly exposed. Secondly, we shed the light on the conditions which allowed the scheme to last several years and those that let it to its termination. The exceptional nature of such a collective endeavour and its fragility are pointed out. Overall, the article highlights that professionals do not benefit from enough institutional support for handling the problems they face.Este artículo presenta una experiencia exitosa de cooperación entre profesionales de la educación, en particular entre profesores y educadores de prevención, en una zona urbana sensible y su colegio. En primer lugar, se desarrolla la historia de este dispositivo puesto en marcha para ayudar al éxito de todos los alumnos. Posteriormente, se ponen de manifiesto las condiciones que han permitido que dure varios años y aquellas que han llevado a su interrupción. Se muestra el carácter excepcional y la fragilidad de un dispositivo colectivo de este tipo, recordando que, de manera general, los profesionales especialistas carecen de un apoyo institucional en relación con la importancia de los problemas que han de resolver

Micro-confinement of bacteria into w/o emulsion droplets for rapid detection and enumeration

International audienceToday, rapid detection and identification of bacteria in microbiological diagnosis is a major issue. Reference methods usually rely on growth of microorganisms, with the drawback of lengthy time-to-result. The method provides global information on a clonal population that is known to be inhomogeneous relative to metabolic states and activities. Therefore, there may be a significant advantage of methods that allow characterisation of individual bacteria from a large population, both for test time reduction and the clinical value of the characterisation. We report here a method for rapid detection and real-time monitoring of the metabolic activities of single bacteria. Water-in-oil emulsions were used to encapsulate single Escherichia coli cells into picolitre (pL)-sized microreactor droplets. The glucuronidase activity in each droplet was monitored using the fluorogenic reporter molecule MUG (4-methylumbelliferyl- - d-glucuronide) coupled to time-lapse fluorescence imaging of the droplets. Such bacterial confinement provides several major advantages. (1) Enzymatic activities of a large number of single bacterium-containing droplet could be monitored simultaneously, allowing the full characterisation of metabolic heterogeneity in a clonal population. We monitored glucuronidase enzymatic activity and growth over ∼200 single bacteria over a 24-h period. (2) Micro-confinement of cells in small volumes allows rapid accumulation of the fluorescent metabolite, hence decreasing the detection time. Independent of the initial concentration of bacteria in the sample, detection of the presence of bacteria could be achieved in less than 2 h. (3) Considering the random distribution of bacteria in droplets, this method allowed rapid and reliable enumeration of bacteria in the initial sample. Overall, the results of this study showed that confinement of bacterial cells increased the effective concentration of fluorescent metabolites leading to rapid (2 h) detection of the fluorescent metabolites, thus significantly reducing time to numeration

Mid-infrared two-octave spanning supercontinuum generation in a Ge-Se-Te glass suspended core fiber

International audienc

1,2-Dihydrophosphete: A Platform for the Molecular Engineering of Electroluminescent Phosphorus Materials for Light-Emitting Devices

International audienceThe discovery and molecular engineering of novel electroluminescent emitting materials is still a challenge in optoelectronics. In this work, we report on the development of new π-conjugated oligomers incorporating a dihydrophosphete skeleton. Variation of the substitution pattern of 1,2-dihydrophosphete derivatives and chemical modification of their P atoms afford thermally stable derivatives which are suitable emitters to construct organic light-emitting diodes. The optical and the electrochemical properties of these new P-based oligomers have been investigated in detail and are supported by DFT calculations. The OLED devices exhibit good performance and current independent CIE coordinate

Dose-response assessment of the anti-cancer efficacy of soy isoflavones in dimethylhydrazine-treated rats fed 6% fructooligosaccharide

We investigated the combinatorial effects of different doses of dietary soy isoflavones (SI) and fructooligosaccharide (FOS) in a rat model of colon cancer. We hypothesized that increased bioavailability of SI metabolites due to dietary FOS may increase production of bioactive equol and affect colon carcinogenesis in a dose-dependent manner. Sprague-Dawley male rats were injected with 12-dimethylhydrazine (DMH) and were provided experimental diets that contained 0, 10, 50, 150, or 500 mg SI per kg of diet and 6% FOS for 12 weeks. The number of aberrant crypt foci (ACF) and the expression of cyclooxygenase-2 (COX-2) in colonic tissues were significantly decreased in the 6% FOS-fed groups compared to the control group. Gut transit time and fecal pH were significantly lower, and fecal concentrations of bifidobacteria were increased with 6% FOS. However, dietary SI supplementation in combination with 6% dietary FOS did not affect ACF formation or COX-2 expression. Plasma equol concentrations were dose-dependently increased by supplementation of SI up to 500 mg/kg of diet. In conclusion, SI supplementation up to 500 mg/kg of diet appeared to have no additive beneficial effects in rats with chemically-induced colon cancer that were fed 6% FOS, although plasma equol was dose-dependently increased

Prebiotic effects: metabolic and health benefits

The different compartments of the gastrointestinal tract are inhabited by populations of micro-organisms. By far the most important predominant populations are in the colon where a true symbiosis with the host exists that is a key for well-being and health. For such a microbiota, 'normobiosis' characterises a composition of the gut 'ecosystem' in which micro-organisms with potential health benefits predominate in number over potentially harmful ones, in contrast to 'dysbiosis', in which one or a few potentially harmful micro-organisms are dominant, thus creating a disease-prone situation. The present document has been written by a group of both academic and industry experts (in the ILSI Europe Prebiotic Expert Group and Prebiotic Task Force, respectively). It does not aim to propose a new definition of a prebiotic nor to identify which food products are classified as prebiotic but rather to validate and expand the original idea of the prebiotic concept (that can be translated in 'prebiotic effects'), defined as: 'The selective stimulation of growth and/or activity(ies) of one or a limited number of microbial genus(era)/species in the gut microbiota that confer(s) health benefits to the host.' Thanks to the methodological and fundamental research of microbiologists, immense progress has very recently been made in our understanding of the gut microbiota. A large number of human intervention studies have been performed that have demonstrated that dietary consumption of certain food products can result in statistically significant changes in the composition of the gut microbiota in line with the prebiotic concept. Thus the prebiotic effect is now a well-established scientific fact. The more data are accumulating, the more it will be recognised that such changes in the microbiota's composition, especially increase in bifidobacteria, can be regarded as a marker of intestinal health. The review is divided in chapters that cover the major areas of nutrition research where a prebiotic effect has tentatively been investigated for potential health benefits. The prebiotic effect has been shown to associate with modulation of biomarkers and activity(ies) of the immune system. Confirming the studies in adults, it has been demonstrated that, in infant nutrition, the prebiotic effect includes a significant change of gut microbiota composition, especially an increase of faecal concentrations of bifidobacteria. This concomitantly improves stool quality (pH, SCFA, frequency and consistency), reduces the risk of gastroenteritis and infections, improves general well-being and reduces the incidence of allergic symptoms such as atopic eczema. Changes in the gut microbiota composition are classically considered as one of the many factors involved in the pathogenesis of either inflammatory bowel disease or irritable bowel syndrome. The use of particular food products with a prebiotic effect has thus been tested in clinical trials with the objective to improve the clinical activity and well-being of patients with such disorders. Promising beneficial effects have been demonstrated in some preliminary studies, including changes in gut microbiota composition (especially increase in bifidobacteria concentration). Often associated with toxic load and/or miscellaneous risk factors, colon cancer is another pathology for which a possible role of gut microbiota composition has been hypothesised. Numerous experimental studies have reported reduction in incidence of tumours and cancers after feeding specific food products with a prebiotic effect. Some of these studies (including one human trial) have also reported that, in such conditions, gut microbiota composition was modified (especially due to increased concentration of bifidobacteria). Dietary intake of particular food products with a prebiotic effect has been shown, especially in adolescents, but also tentatively in postmenopausal women, to increase Ca absorption as well as bone Ca accretion and bone mineral density. Recent data, both from experimental models and from human studies, support the beneficial effects of particular food products with prebiotic properties on energy homaeostasis, satiety regulation and body weight gain. Together, with data in obese animals and patients, these studies support the hypothesis that gut microbiota composition (especially the number of bifidobacteria) may contribute to modulate metabolic processes associated with syndrome X, especially obesity and diabetes type 2. It is plausible, even though not exclusive, that these effects are linked to the microbiota-induced changes and it is feasible to conclude that their mechanisms fit into the prebiotic effect. However, the role of such changes in these health benefits remains to be definitively proven. As a result of the research activity that followed the publication of the prebiotic concept 15 years ago, it has become clear that products that cause a selective modification in the gut microbiota's composition and/or activity(ies) and thus strengthens normobiosis could either induce beneficial physiological effects in the colon and also in extra-intestinal compartments or contribute towards reducing the risk of dysbiosis and associated intestinal and systemic pathologies

Benzofuran-fused Phosphole: Synthesis, Electronic, and Electroluminescence Properties

International audienceA synthetic route to novel benzofuran-fused phosphole derivatives 3-5 is described. These compounds showed optical and electrochemical properties that differ from their benzothiophene analog. Preliminary results show that 4 can be used as an emitter in OLEDs, illustrating the potential of these new compounds for opto-electronic applications