Les sciences sociales à l’épreuve de l’expertise

Dans son premier numéro, Sociologie a interrogé la posture du sociologue dans le champ médiatique. Dans le prolongement d’un autre questionnement initié lors du colloque « Le sociologue dans la Cité. Éthique et utilité publique » tenu à l’Ehess, les rapports de la production de connaissance en sciences sociales avec l’aide à la décision politique, le champ de l’expertise, font ici l’objet d’une attention particulière (...)

Humanos y no-humanos: un balance de la etapa alcanzada en la sociología de los colectivos

En los últimos años, numerosos trabajos se han esforzado por establecer los contornos de un modo de existencia social de los objetos que escapan al doble obstáculo naturalista y constructivista. Sobre esta base, mostramos cómo es posible renovar las teorías de la acción y del actor. Sobre todo, sugerimos que conviene dotar al actor de un sentido ordinario de la objetividad que dé cuenta de sus posibilidades de compromiso en una amplia gama de relaciones con los objetos. En la segunda parte, revisamos algunas herramientas de análisis del “colectivo”, término forjado por Bruno Latour para designar lo social extendido a los no-humanos que lo componen. Mostramos la dimensión política que oculta cada uno de los ensamblajes de personas y objetos así identificados.Over the last few years a lot of research work has focused on establishing the outline of a mode of social existence of objects in order to escape the dual naturalist and constructivist pitfall. On this basis, we show how it is possible to renew action and actor theories. We notably suggest that an actor should be given an ordinary sense of objectiveness, which takes into account their possibility to engage within a wide range of object relations. In the second part, we review several tools used to analyze a “collective”, the term forged by B. Latour to refer to the social world as extended to the non-humans making it up. We underline the political dimension embedded in each assembly of persons and objects identified in this way

Expression of cell wall related genes in basal and ear internodes of silking brown-midrib-3, caffeic acid O-methyltransferase (COMT) down-regulated, and normal maize plants

<p>Abstract</p> <p>Background</p> <p>Silage maize is a major forage and energy resource for cattle feeding, and several studies have shown that lignin content and structure are the determining factors in forage maize feeding value. In maize, four natural <it>brown-midrib </it>mutants have modified lignin content, lignin structure and cell wall digestibility. The greatest lignin reduction and the highest cell wall digestibility were observed in the <it>brown-midrib-3 </it>(<it>bm3</it>) mutant, which is disrupted in the caffeic acid <it>O</it>-methyltransferase (COMT) gene.</p> <p>Results</p> <p>Expression of cell wall related genes was investigated in basal and ear internodes of normal, COMT antisens (AS225), and <it>bm3 </it>maize plants of the INRA F2 line. A cell wall macro-array was developed with 651 gene specific tags of genes specifically involved in cell wall biogenesis. When comparing basal (older lignifying) and ear (younger lignifying) internodes of the normal line, all genes known to be involved in constitutive monolignol biosynthesis had a higher expression in younger ear internodes. The expression of the COMT gene was heavily reduced, especially in the younger lignifying tissues of the ear internode. Despite the fact that AS225 transgene expression was driven only in sclerenchyma tissues, COMT expression was also heavily reduced in AS225 ear and basal internodes. COMT disruption or down-regulation led to differential expressions of a few lignin pathway genes, which were all over-expressed, except for a phenylalanine ammonia-lyase gene. More unexpectedly, several transcription factor genes, cell signaling genes, transport and detoxification genes, genes involved in cell wall carbohydrate metabolism and genes encoding cell wall proteins, were differentially expressed, and mostly over-expressed, in COMT-deficient plants.</p> <p>Conclusion</p> <p>Differential gene expressions in COMT-deficient plants highlighted a probable disturbance in cell wall assembly. In addition, the gene expressions suggested modified chronology of the different events leading to cell expansion and lignification with consequences far beyond the phenylpropanoid metabolism. The reduced availability of monolignols and S units in <it>bm3 </it>or AS225 plants led to plants also differing in cell wall carbohydrate, and probably protein, composition. Thus, the deficiency in a key-enzyme of the lignin pathway had correlative effects on the whole cell wall metabolism. Furthermore, the observed differential expression between <it>bm3 </it>and normal plants indicated the possible involvement in the maize lignin pathway of genes which up until now have not been considered to play this role.</p

Maize cell wall degradability, from whole plant to tissue level: different scales of complexity

Today, maize stover can be considered as a model for investigating secondary cell wall formation in grasses with major applications in cattle feeding (forage maize) and green energy production (bioethanol, biogas, etc). Up until now, cell wall formation and cell wall degradability have been considered at the whole plant scale. However, a detailed examination of leaves and internodes has underlined a large diversity of lignified cell types (xylem vessels, parenchyma, sub-epidermal and perivascular sclerenchyma) and significant variations in the organization and / or the composition of these different cell types. In this review, we highlighted several aspects of this complexity and their consequences on valorization processes both in agriculture or industries

Projections from the Dorsomedial Division of the Bed Nucleus of the Stria Terminalis to Hypothalamic Nuclei in the Mouse

Acknowledgments: All the authors contributed to perform the experiments. SC designed the experiments, analyzed the data and wrote the paper. MB, JAG, DB and PYR edited the manuscript. This work was supported by the Region Franche-Comté, France (PYR), by The Francis Crick Institute (DB), by the Swiss National Science Foundation (PZ00P3_167934/1) and the Novartis Foundation for medical-biological research (19B145) (SC) The data that support the findings of this study are available from the corresponding author upon reasonable request.Peer reviewedPublisher PD