Inverse opal ceria–zirconia: architectural engineering for heterogeneous catalysis

The application of inverse opal structured materials is extended to the ceria–zirconia (Ce_(0.5)Zr_(0.5)O_2) system and the significance of material architecture on heterogeneous catalysis, specifically, chemical oxidation, is examined

RUNX1 Reshapes the Epigenetic Landscape at the Onset of Haematopoiesis

Cell fate decisions during haematopoiesis are governed by lineage-specific transcription factors, such as RUNX1, SCL/TAL1, FLI1 and C/EBP family members. To gain insight into how these transcription factors regulate the activation of haematopoietic genes during embryonic development, we measured the genome-wide dynamics of transcription factor assembly on their target genes during the RUNX1-dependent transition from haemogenic endothelium (HE) to haematopoietic progenitors. Using a $Runx1^{−/−}$ embryonic stem cell differentiation model expressing an inducible Runx1 gene, we show that in the absence of RUNX1, haematopoietic genes bind SCL/TAL1, FLI1 and C/EBPβ and that this early priming is required for correct temporal expression of the myeloid master regulator PU.1 and its downstream targets. After induction, RUNX1 binds to numerous de novo sites, initiating a local increase in histone acetylation and rapid global alterations in the binding patterns of SCL/TAL1 and FLI1. The acquisition of haematopoietic fate controlled by Runx1 therefore does not represent the establishment of a new regulatory layer on top of a pre-existing HE program but instead entails global reorganization of lineage-specific transcription factor assemblies

Microglia activation in a model of retinal degeneration and TUDCA neuroprotective effects

Background: Retinitis pigmentosa is a heterogeneous group of inherited neurodegenerative retinal disorders characterized by a progressive peripheral vision loss and night vision difficulties, subsequently leading to central vision impairment. Chronic microglia activation is associated with various neurodegenerative diseases including retinitis pigmentosa. The objective of this study was to quantify microglia activation in the retina of P23H rats, an animal model of retinitis pigmentosa, and to evaluate the therapeutic effects of TUDCA (tauroursodeoxycholic acid), which has been described as a neuroprotective compound. Methods: For this study, homozygous P23H line 3 and Sprague-Dawley (SD) rats were injected weekly with TUDCA (500 mg/kg, ip) or vehicle (saline) from 20 days to 4 months old. Vertical retinal sections and whole-mount retinas were immunostained for specific markers of microglial cells (anti-CD11b, anti-Iba1 and anti-MHC-II). Microglial cell morphology was analyzed and the number of retinal microglial was quantified. Results: Microglial cells in the SD rat retinas were arranged in regular mosaics homogenously distributed within the plexiform and ganglion cell layers. In the P23H rat retina, microglial cells increased in number in all layers compared with control SD rat retinas, preserving the regular mosaic distribution. In addition, a large number of amoeboid CD11b-positive cells were observed in the P23H rat retina, even in the subretinal space. Retinas of TUDCA-treated P23H animals exhibited lower microglial cell number in all layers and absence of microglial cells in the subretinal space. Conclusions: These results report novel TUDCA anti-inflammatory actions, with potential therapeutic implications for neurodegenerative diseases, including retinitis pigmentosa.This research was supported by grants from the Spanish Ministry of Economy and Competitiveness-FEDER (BFU2012-36845), Instituto de Salud Carlos III (RETICS RD12/0034/0010), Organización Nacional de Ciegos Españoles (ONCE), FUNDALUCE, Asociación Retina Asturias and Fundación Jesús de Gangoiti

Evaluation de la bande MIR de SPOT 4 pour le suivi agro-environnemental de la zone cotonnière Ouest du Burkina Faso : rapport final

La région Ouest du Burkina Faso dispose encore des terres cultivables. Elle constitue un important pôle d'attraction des populations originaires des zones Nord et Centre du pays où la pression démographique est forte. Il en résulte des problèmes de saturation de l'espace et de dégradation du milieu et de la fertilité du sol. Pour les responsables du développement, l'organisation d'un système permanent d'observation et d'information agro-environnemental devient urgente. Un projet est initié afin d'évaluer les apports pratiques et théoriques du canal MIR de SPOT 4 pour la cartographie des grandes formations végétales et du domaine cultivé ainsi que pour l'amélioration des statistiques agricoles en zone soudanienne (appui à la statistique cotonnière et gestion des ressources naturelles). L'analyse de la bande MIR permet une meilleure observation des zones où l'humidité est plus importante, aussi bien sur des sols cultivés que sur des sols non cultivés. Une autre amélioration concerne la partition numérique entre sols cultivés et non cultivés. En effet, le canal MIR permet de différencier les sols cultivés avec végétation verte clairsemée et les sols non cultivés avec une couverture végétale jaunissante. Cette distinction relative aux pixels de végétation peut s'observer visuellement dans certaines situations mais reste toutefois très subtile. Par contre, il n'y aucune amélioration dans la distinction entre céréales sèches ou sénescentes et sols non cultivés recouverts de végétation herbacée sèch

Ulva armoricana (Ulvales, Chlorophyta) from the coasts of Brittany (France). II. Nuclear rDNA ITS sequence analysis

International audienc

Enhancement of the magnetoresistence at the Curie temperature of the ferromagnetic insulator La_1.5Sr_0.5MnRhO₆

We report a study of the magnetic and electrical properties of the ferromagnetic insulator La1.5Sr0.5MnRhO6. A significant magnetoresistance is found in this system which is largest at the Curie temperature (Tc) even though there is no metal-insulator transition. The electrical transport is found to be activated above Tc and described by a variable range hopping law below Tc. Above Tc the carriers are magnetic polarons with a size which increases as the temperature approaches the magnetic transition. Rh substitution preserves ferromagnetic ordering, in contrast with the effect of other dopants on the B sites, but modifies the electrostatic potential leading to carrier localization. We attribute the peak in the magnetoresistance at Tc to the field-induced suppression of critical spin fluctuations which modulate the energetic barriers seen by the carriers