52 research outputs found

    An improved method to produce adults of Costelytra zealandica White (Coleoptera: Melolothinae) from field-collected larvae

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    Rearing techniques provide a unique opportunity to study aspects of insect ecology, behaviour and physiology. Both the larval and adult stages in Melolonthinae scarabs have important impacts on crop and pasture yields worldwide. Rearing techniques for this group of phytophagous beetles usually results in a low survival rate from larva to adult, varying from 10% to 50%. Here, the current rearing method used for the New Zealand grass grub (Costelytra zealandica) was improved by increasing the pupation weight threshold, as well as by changing the container type used to rear the larvae. This improved method produced an 83% increase in the survival rate from larva to adult, and the technique developed here may help increase the laboratory survival rate of other Melolonthinae species worldwide

    CLUH regulates mitochondrial metabolism by controlling translation and decay of target mRNAs

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    Mitochondria are essential organelles that host crucial metabolic pathways and produce adenosine triphosphate. The mitochondrial proteome is heterogeneous among tissues and can dynamically change in response to different metabolic conditions. Although the transcriptional programs that govern mitochondrial biogenesis and respiratory function are well known, posttranscriptional regulatory mechanisms remain unclear. In this study, we show that the cytosolic RNA-binding protein clustered mitochondria homologue (CLUH) regulates the expression of a mitochondrial protein network supporting key metabolic programs required under nutrient deprivation. CLUH exerts its function by controlling the stability and translation of target messenger RNAs. In the absence of Cluh, mitochondria are severely depleted of crucial enzymes involved in catabolic energy-converting pathways. CLUH preserves oxidative mitochondrial function and glucose homeostasis, thus preventing death at the fetal–neonatal transition. In the adult liver, CLUH ensures maximal respiration capacity and the metabolic response to starvation. Our results shed new light on the posttranscriptional mechanisms controlling the expression of mitochondrial proteins and suggest novel strategies to tailor mitochondrial function to physiological and pathological conditions.Peer reviewe

    Pierre-Alain Mercier, François Plassard et Victor Scardigli, La société digitale. Les nouvelles technologies au futur quotidien, 1984

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    Postic Marie-Noëlle. Pierre-Alain Mercier, François Plassard et Victor Scardigli, La société digitale. Les nouvelles technologies au futur quotidien, 1984. In: Sociologie du travail, 27ᵉ année n°3, Juillet-septembre 1985. L'action industrielle de l'Etat. pp. 361-363

    Pierre-Alain Mercier, François Plassard et Victor Scardigli, La société digitale. Les nouvelles technologies au futur quotidien, 1984

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    Postic Marie-Noëlle. Pierre-Alain Mercier, François Plassard et Victor Scardigli, La société digitale. Les nouvelles technologies au futur quotidien, 1984. In: Sociologie du travail, 27ᵉ année n°3, Juillet-septembre 1985. L'action industrielle de l'Etat. pp. 361-363

    La maladie thrombo-embolique veineuse (description et devenir chez la personne âgée de plus de 70 ans)

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    BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Auto-organisation de matériaux multi-échelles par séchage (des mécanismes de retrait des ménisques dans un milieu poreux modèle à la cristallisation de nanoparticules)

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    L'organisation des matériaux sur plusieurs échelles de longueur peut leur donner des propriétés physiques spécifiques intéressantes pour l'optique, ou la biodétection par exemple. Il est en particulier possible d'atteindre une organisation hiérarchique de nanoparticules par évaporation d'une suspension colloïdale sur une surface texturée. Cette thèse porte sur l'auto-organisation de matériaux multi échelles par séchage d'une solution en milieu poreux modèle formé entre un substrat et une surface décorée d'un réseau de plots micrométriques. Nous avons étudié les mécanismes de recul d'un ménisque conduisant à la formation de films durant l'évaporation d'une solution de tensioactifs dans ce milieu. Nous avons de plus pu établir un modèle numérique rendant compte des évolutions temporelles des paramètres macroscopiques de la goutte tels que son aire, son périmètre ou la morphologie des films formés. Nous avons ensuite effectué des expériences de séchage en milieu poreux modèle de suspensions de quantum dots fonctionnalisés par des molécules amphiphiles et nous avons caractérisé les matériaux obtenus par diffraction des rayons X aux petits angles et par différentes techniques de microscopie. Nous avons enfin pu généraliser cette technique d'auto-organisation multi-échelle à des nanobâtonnets métalliques ou semiconducteurs.The multi-scale organization of materials can give them specific physical properties making them interesting devices for applications in many fields that include optics and bio-detection. It is possible to achieve a hierarchical organization of nanoparticles via the evaporation of a colloidal suspension on a micro-textured surface. This work focuses on the self-organization of multi-scale materials through the drying of complex fluids in a porous medium consisting of an assembly of regularly arranged micron-sized pillars. More specifically, we have studied experimentally the physical mechanisms behind the retraction of menisci that occurs during the drying of a solution of surfactants and leads to the formation of dried-liquid films between pillars. In addition, we have developed a simple model based on experimental observations that allows us to predict the evolution of most of the macroscopic features of the drying drop, that is, its area, its perimeter, and the morphology of the obtained films. Then, we studied the drying of suspensions containing quantum dots functionalized with amphiphilic molecules and we characterized the resulting material using several techniques, including small angle X-ray diffraction and optical microscopy. We conclude with a generalization of this technique to the drying of suspensions containing other particles such as gold nanorods and semiconducting nanorods.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

    Observer les situations éducatives /

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    Bibliogr.: p. 291-311Notes (part. bibliogr.) au bas des p
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