160 research outputs found
EnquĂȘte sur l'enquĂȘte 'Les rĂ©seaux Ă©conomiques souterrains en citĂ© de transit (1981-2010)' de Jean-François LaĂ© et Numa Murard
LâenquĂȘte « Les rĂ©seaux Ă©conomiques souterrains en citĂ© de transit » a Ă©tĂ© rĂ©alisĂ©e par Jean-François LaĂ©, professeur Ă©mĂ©rite de lâUniversitĂ© Paris 8 Vincennes â Saint Denis et Numa Murard, professeur Ă©mĂ©rite de lâUniversitĂ© Paris Diderot. Elle a la particularitĂ© dâavoir Ă©tĂ© menĂ©e en deux fois, puisquâelle a donnĂ© lieu Ă une premiĂšre enquĂȘte rĂ©alisĂ©e au dĂ©but des annĂ©es 1980 puis Ă un retour sur enquĂȘte en 2010. Lâorigine de cette recherche remonte Ă lâexpĂ©rience de Jean-François LaĂ© comme travailleur social dans une citĂ© dite de transit de la ville dâElbeuf, en Seine-Maritime. AprĂšs sa rencontre avec Numa Murard au CERFI (Centre dâĂ©tudes, de recherche et de formation institutionnelle), ils dĂ©cident tous deux de rĂ©aliser cette enquĂȘte, ayant obtenu des financements de la CNAF (Caisse nationale des affaires familiales) et du ministĂšre de lâUrbanisme et du Logement. Elle donnera lieu Ă la rĂ©daction dâun rapport et Ă la publication dâun ouvrage en 1985, LâArgent des pauvres. Trente ans plus tard, les deux chercheurs dĂ©cident de revenir sur les terrains de leur premiĂšre enquĂȘte, dans le cadre dâun documentaire radiophonique. Un ouvrage sera publiĂ© suite Ă ce retour, intitulĂ© Deux gĂ©nĂ©rations dans la dĂ©bine et paru en 2012. Pour lâenquĂȘte initiale comme pour le retour sur enquĂȘte, les deux chercheurs se sont immergĂ©s en ethnographes dans la vie quotidienne des habitants de la citĂ© de transit. Sâils se sont principalement focalisĂ©s sur la vie Ă©conomique des enquĂȘtĂ©s, ils ont ouvert un ensemble de thĂ©matique allant bien au-delĂ de ce que laisse Ă penser le titre de lâenquĂȘte. Si la mĂ©thodologie est particuliĂšre, la mĂ©thode dâexposition lâest tout autant puisquâelle ressort de ce que Jean-François LaĂ© et Numa Murard appellent la « sociologie narrative ». Le corpus de documents fourni par les chercheurs a trait aux deux Ă©tapes de cette recherche. Il rĂ©unit notamment un carnet de terrain et le rapport publiĂ© suite Ă la premiĂšre enquĂȘte, de mĂȘme que diffĂ©rentes notes prĂ©paratoires, des photos et des transcriptions dâenregistrements collectĂ©s lors du retour sur enquĂȘte. Sâil est parcellaire du fait de la perte de certains documents, ce corpus donne une idĂ©e prĂ©cise des mĂ©thodes dâenquĂȘte des deux chercheurs et ouvre des pistes de rĂ©utilisation, notamment dans un cadre pĂ©dagogique.
Deux entretiens ont Ă©tĂ© rĂ©alisĂ©s par l'Ă©quipe beQuali avec les auteurs de l'enquĂȘte : le premier avec Jean-François LaĂ©,Numa Murard et Fabien Deshayes au CRESPPA, le deuxiĂšme avec Jean-François LaĂ© et Numa Murard au CDSP
The Avian Transcription Factor c-Rel is Expressed in Lymphocyte Precursor Cells and Antigen-Presenting Cells During Thymus Development
Transcription factors of the Rel/NF-ÎșB family are widely involved in the immune system. In this
study, we investigate the in vivo expression of the avian protein c-Rel in the T-cell lineage during
thymus development. The majority of thymocytes do not express the c-Rel protein. However,
lymphocyte precursor cells that colonize the thymus express the c-Rel protein shortly after their
homing in the organ and before they begin to differentiate, c-Rel is also detected in different
subsets of,antigen-presenting cells such as epithelial cells, dendritic cells, and macrophages. In
vitro studies have shown that Rel/NF-ÎșB proteins are sequestered in an inactive form in the
cytoplasm by interaction with the IÎșBα inhibitory protein. By immunocytochemistry, we show
that in vivo c-Rel is localized in the cytoplasm of antigen-presenting cells but in both the
cytoplasm and nucleus of lymphocyte precursor cells. The cytoplasmic localization of c-Rel in
antigen-presenting cells correlates with a high expression of IÎșBα, whereas the nuclear
localization of c-Rel in lymphocyte precursor cells correlates with a much lower expression of
IÎșBα. These results suggest that c-Rel might be constitutively activated in lymphocyte precursor
cells
Ets1-Related Protein Is a Key Regulator of Vasculogenesis in Zebrafish
During embryonic development, multiple signaling pathways control specification, migration, and differentiation of the vascular endothelial cell precursors, angioblasts. No single gene responsible for the commitment of mesenchymal cells to the angioblast cell fate has been identified as yet. Here we report characterization and functional studies of Etsrp, a novel zebrafish ETS domain protein. etsrp embryonic expression is only restricted to vascular endothelial cells and their earliest precursors. Morpholino knockdown of Etsrp protein function resulted in the complete absence of circulation in zebrafish embryos. Angioblasts in etsrpâmorpholino-injected embryos (morphants) failed to undergo migration and differentiation and did not coalesce into functional blood vessels. Expression of all vascular endothelial molecular markers tested was severely reduced in etsrp morphants, whereas hematopoietic markers were not affected. Overexpression of etsrp RNA caused multiple cell types to express vascular endothelial markers. etsrp RNA restored expression of vascular markers in cloche mutants, defective in hematopoietic and endothelial cell formation, arguing that etsrp functions downstream of cloche in angioblast formation. etsrp gene function was also required for endothelial marker induction by the vascular endothelial growth factor (vegf) and stem cell leukemia (scl/tal1). These results demonstrate that Etsrp is necessary and sufficient for the initiation of vasculogenesis
VE-statin/egfl7 Expression in Endothelial Cells Is Regulated by a Distal Enhancer and a Proximal Promoter under the Direct Control of Erg and GATA-2
Angiogenesis is the process by which new blood vessels arise from existing ones by the budding out of endothelial cell capillaries from the luminal side of blood vessels. Blood vessel formation is essential for organ development during embryogenesis and is associated with several physiological and pathological processes, such as wound healing and tumor development. The VE-statin/egfl7 gene is specifically expressed in endothelial cells during embryonic development and in the adult. We studied here the regulatory mechanisms that control this tissue-specific expression. RT-qPCR analyses showed that the specificity of expression of VE-statin/egfl7 in endothelial cells is not shared with its closest neighbor genes notch1 and agpat2 on the mouse chromosome 2. Chromatin-immunoprecipitation analysis of histone modifications at the VE-statin/egfl7 locus showed that the chromatin is specifically opened in endothelial cells, but not in fibroblasts at the transcription start sites. A 13 kb genomic fragment of promoter was cloned and analyzed by gene reporter assays which showed that two conserved regions are important for the specific expression of VE-statin/egfl7 in endothelial cells; a â8409/â7563 enhancer and the â252/+38 region encompassing the exon-1b transcription start site. The latter contains essential GATA and ETS-binding sites, as assessed by linker-scanning analysis and site-directed mutagenesis. An analysis of expression of the ETS and GATA transcription factors showed that Erg, Fli-1 and GATA-2 are the most highly expressed factors in endothelial cells. Erg and GATA-2 directly control the expression of the endogenous VE-statin/egfl7 while Fli-1 probably exerts an indirect control, as assessed by RNA interference and chromatin immunoprecipitation. This first detailed analysis of the mechanisms that govern the expression of the VE-statin/egfl7 gene in endothelial cells pinpoints the specific importance of ETS and GATA factors in the specific regulation of genes in this cell lineage
The human embryo, but not its yolk sac, generates lympho-myeloid stem cells: Mapping multipotent hematopoietic cell fate in intraembryonic mesoderm
AbstractWe have traced emerging hematopoietic cells along human early ontogeny by culturing embryonic tissue rudiments in the presence of stromal cells that promote myeloid and B cell differentiation, and by assaying T cell potential in the NOD-SCID mouse thymus. Hematogenous potential was present inside the embryo as early as day 19 of development in the absence of detectable CD34+ hematopoietic cells, and spanned both lymphoid and myeloid lineages from day 24 in the splanchnopleural mesoderm and derived aorta where CD34+ progenitors appear at day 27. By contrast, hematopoietic cells arising in the third week yolk sac, as well as their progeny at later stages, were restricted to myelopoiesis and therefore are unlikely to contribute to definitive hematopoiesis in man
Ets-1 Confers Cranial Features on Neural Crest Delamination
Neural crest cells (NCC) have the particularity to invade the environment where they differentiate after separation from the neuroepithelium. This process, called delamination, is strikingly different between cranial and trunk NCCs. If signalings controlling slow trunk delamination start being deciphered, mechanisms leading to massive and rapid cranial outflow are poorly documented. Here, we show that the chick cranial NCCs delamination is the result of two events: a substantial cell mobilization and an epithelium to mesenchyme transition (EMT). We demonstrate that ets-1, a transcription factor specifically expressed in cranial NCCs, is responsible for the former event by recruiting massively cranial premigratory NCCs independently of the S-phase of the cell cycle and by leading the gathered cells to straddle the basal lamina. However, it does not promote the EMT process alone but can cooperate with snail-2 (previously called slug) to this event. Altogether, these data lead us to propose that ets-1 plays a pivotal role in conferring specific cephalic characteristics on NCC delamination
Peut-on enseigner lâart ? : Les Ă©coles supĂ©rieures dâart, entre forme scolaire et libertĂ© artistique.
International audienceThis article seeks to highlight original teaching methods, inspired by the charismatic status of the artist, which are being used in French art schools. Using a set of ethnographic data (observations, interviews), the author reveals how art schools are breaking away from the academic pattern by concentrating on a teaching style which promotes student autonomy. Firstly, the study of the curricula developed in different art schools serves to demonstrate how these curricula evolve, between first and final year, from a âcollection typeâ to an âintegratedâ one. The author then shows what form the ideal type of âpedagogy for autonomyâ takes in art schools and what the implications are for the distribution of knowledge and power between teachers and students. Finally, the author reveals the tension that can exist between two contradictory parts which students have to play: between the need to claim artistic autonomy and the obligation to respect some elements of the academic pattern.Cet article vise Ă mettre en lumiĂšre les modalitĂ©s pĂ©dagogiques originales mises en Ćuvre dans les Ă©coles supĂ©rieures dâart françaises, en lien avec le statut charismatique de lâartiste. Sâappuyant sur un ensemble de donnĂ©es de type ethnographique (observations, entretiens), lâauteur tente de montrer comment les Ă©coles dâart sâĂ©mancipent radicalement de la forme scolaire tout en mettant en avant une pĂ©dagogie centrĂ©e sur lâautonomie de lâĂ©tudiant. Dans un premier temps, lâĂ©tude des curricula dĂ©veloppĂ©s dans diffĂ©rents Ă©tablissements permet de montrer comment ceux-ci Ă©voluent au cours du cursus dâune relative intĂ©gration jusquâĂ lâouverture la plus complĂšte. Ensuite, lâauteur dĂ©montre de quelle maniĂšre lâidĂ©al-type de « la pĂ©dagogie de lâautonomie » sâincarne aux beaux-arts et comment y sont soulevĂ©s les enjeux que cette pĂ©dagogie implique pour la distribution des savoirs et des pouvoirs entre enseignants et Ă©tudiants. Enfin, lâauteur met au jour la tension qui peut exister entre deux positions contradictoires que lâĂ©tudiant se doit dâadopter : entre la nĂ©cessitĂ© de revendiquer une rĂ©elle autonomie artistique et lâobligation de respecter certains Ă©lĂ©ments du cadre scolaire.
Du collectif dans les Ă©coles supĂ©rieures dâart. Entre rĂ©gime de singularitĂ©, Ă©valuation scolaire et construction de rĂ©seaux.
International audienceCette communication vise Ă Ă©tudier la façon dont le(s) collectif(s) peu(ven)t exister dans les Ă©coles supĂ©rieures dâart françaises et les contraintes spĂ©cifiques que soulĂšvent de telles collaborations entre Ă©tudiants artistes. En partant dâexemples concrets, cette communication a pour objectif de mettre en lumiĂšre les diffĂ©rents obstacles qui sâopposent Ă la construction dâun collectif (voire de collaborations ponctuelles) dans les Ă©coles dâart. Dâun cĂŽtĂ©, le « rĂ©gime de singularitĂ© » propre Ă la crĂ©ation artistique, et notamment dans les arts plastiques, semble ĂȘtre intrinsĂšquement contraire Ă la rĂ©alisation de tels collectifs de travail. De lâautre, la nĂ©cessitĂ© dâĂ©valuer des individus isolĂ©s, dans un cadre scolaire et afin de dĂ©livrer des diplĂŽmes, empĂȘchent Ă©galement la prĂ©sentation dâĆuvres produites collectivement, obligation Ă©tant de distinguer les contributions de chacun. Pour autant, les collectifs dâartistes, rĂ©unissant plusieurs Ă©tudiants, peuvent exister aux beaux-arts. Ils peuvent sâinscrire ainsi dans une volontĂ© de rapprochement entre pairs, partageant des conditions similaires, Ă un Ăąge oĂč ce type de sociabilitĂ© est Ă©levĂ©. Le travail collaboratif peut Ă©galement ĂȘtre encouragĂ© par les enseignants eux-mĂȘmes, souhaitant par lĂ mĂȘme favoriser les Ă©changes entre Ă©tudiants et, surtout, crĂ©er un vĂ©ritable esprit de classe (ici entendue au sens scolaire du terme). Enfin, cette communication vise Ă apporter un Ă©clairage gĂ©nĂ©ral sur la notion de collectif dans les Ă©coles dâart, revenant ainsi sur les formes de collaboration et dâentraide qui peuvent exister aux beaux-arts, mais aussi sur la compĂ©tition entre Ă©tudiants quâon peut Ă©galement observer. Cette communication sâappuie sur un travail de terrain menĂ© dans le cadre dâune thĂšse de doctorat soutenue en mars 2014. Il a notamment permis de collecter des Ă©lĂ©ments empiriques variĂ©s, Ă la fois qualitatifs et quantitatifs. Ainsi, prĂšs de 80 entretiens ont Ă©tĂ© rĂ©alisĂ©s, avec des enseignant(e)s et des Ă©tudiant(e)s issu(e)s de diffĂ©rentes Ă©coles dâart. De mĂȘme, des observations ont Ă©tĂ© mises en Ćuvre sur des pĂ©riodes allant dâune semaine Ă un semestre, dans trois Ă©tablissements diffĂ©rents, en Ăle-de-France et dans le Nord. Ces donnĂ©es ethnographiques constituent le socle de cette communication. Elles sont complĂ©tĂ©es par une Ă©tude des documentations produites par les Ă©tablissements (les « livrets de lâĂ©tudiant » notamment).Cette communication vise donc Ă comprendre dans quelle mesure les collectifs de travail peuvent exister aux beaux-arts, dans un contexte oĂč les habitudes de travail, la culture professionnelle et les rĂšgles scolaires constituent des obstacles Ă ce type de pratiques. En premier lieu, je prĂ©senterais la façon dont le « rĂ©gime de singularitĂ© » propre Ă la crĂ©ation artistique sâoppose Ă la crĂ©ation de collectif dans les Ă©coles dâart et implique dans ces Ă©tablissements la mise en Ćuvre dâun enseignement fortement individualisĂ©e. Ensuite, je mettrais en lumiĂšre la façon dont les rĂšgles scolaires, notamment en ce qui concerne lâĂ©valuation, sont Ă©galement un frein Ă la crĂ©ation de collectif et quelles peuvent en ĂȘtre les consĂ©quences pour les Ă©tudiants. Enfin, adoptant un point de vue plus gĂ©nĂ©ral pour aborder la question du travail collectif, je montrerais comment les Ă©coles dâart sont Ă la fois des lieux de collaborations et de compĂ©titions
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