Wegvliegen in het oneindige. De plafondschilderingen in het Koninklijk Paleis Amsterdam

In 1655-1656 the ceilings of the Weeskamer and the Thesaurie Ordinaris of the Amsterdam town hall were painted by Cornelis Holsteijn, that of the Justitiekamer by Nicolaes van Helt Stockade and that of the Burgemeesterskamer by Jan van Bronkhorst. The allegorical representations of justice, against the backdrop of a blue sky, are embedded in the architectural structure of the rooms on the first floor. In 2006, the Stichting Restauratie Atelier Limburg was commissioned to study the effects that natural aging and interventions done in the past had had on the linen canvas and the painter’s materials that had been used. The fact that smalt, a blue pigment that turns grey over time, was used for the sky parts had repeatedly led to extensive restorations. The 19th-century wax-resin canvasses no longer provided sufficient support and extensive repainting of the original surfaces – which in turn also suffered from discoloration – made it necessary to intervene again. The restoration consisted of urgent conservative interventions to make the canvas robust again and an extensive cleaning of the painted surface to bring to light the trompe-l’oeil effect again. By removing the much yellowed and shiny layers of varnish as well as the discoloured repainted parts, the original rendition of space in the painted ceilings was done justice again. The reconstruction of the authentic colours of the architecture was done on the basis of information gained from elements that had never been painted over. The combined interventions restored the ensemble to its former unity.In 1655-1656 werden plafondschilderingen voor de Weeskamer en de Thesaurie Ordinaris van het Amsterdamse stadhuis gemaakt door Cornelis Holsteijn, voor de Justitiekamer door Nicolaes van Helt Stockade en voor de Burgemeesterskamer door Jan van Bronkhorst. De allegorische voorstellingen op de rechtspraak, tegen de achtergrond van een blauwe hemel, zijn gevat in de architectonische structuur van de zalen op de bel-étage. In 2006 kreeg de Stichting Restauratie Atelier Limburg de opdracht om de effecten van natuurlijke veroudering en ingrepen uit het verleden op de linnen drager en de gebruikte schildersmaterialen te onderzoeken. Het gebruik van smalt voor de hemelpartijen, een blauw pigment dat na verloop van tijd vergrijst, had herhaaldelijk aanleiding gegeven tot ingrijpende restauraties. De was-hars bedoekingen uit de negentiende eeuw hadden hun steunfunctie verloren en breedvoerige overschilderingen van het oorspronkelijk verfoppervlak, die op hun beurt ook weer waren verkleurd, maakten een nieuwe behandeling noodzakelijk. De restauratie bestond uit urgente conserverende ingrepen om de linnen dragers weer stevigheid te bieden en een ingrijpende schoonmaak van het verfoppervlak om het trompe-l’oeil -effect weer tot uitdrukking te brengen. Door de verwijdering van sterk vergeelde en glimmende vernislagen, en van de verkleurde overschilderingen kwam de oorspronkelijke weergave van de ruimte in de plafondschilderingen weer tot haar recht. De reconstructie van de authentieke kleuren van de architectuur werd uitgevoerd op basis van gegevens afkomstig van onderdelen die nooit overschilderd waren geweest. Deze twee ingrepen herstelden de eenheid van het ensemble

LptM promotes oxidative maturation of the lipopolysaccharide translocon by substrate binding mimicry

Insertion of lipopolysaccharide (LPS) into the bacterial outer membrane (OM) is mediated by a druggable OM translocon consisting of a β-barrel membrane protein, LptD, and a lipoprotein, LptE. The β-barrel assembly machinery (BAM) assembles LptD together with LptE at the OM. In the enterobacterium Escherichia coli, formation of two native disulfide bonds in LptD controls translocon activation. Here we report the discovery of LptM (formerly YifL), a lipoprotein conserved in Enterobacteriaceae, that assembles together with LptD and LptE at the BAM complex. LptM stabilizes a conformation of LptD that can efficiently acquire native disulfide bonds, whereas its inactivation makes disulfide bond isomerization by DsbC become essential for viability. Our structural prediction and biochemical analyses indicate that LptM binds to sites in both LptD and LptE that are proposed to coordinate LPS insertion into the OM. These results suggest that, by mimicking LPS binding, LptM facilitates oxidative maturation of LptD, thereby activating the LPS translocon

Rapid response to the M_w 4.9 earthquake of November 11, 2019 in Le Teil, Lower Rhône Valley, France

On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower Rhône Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude, and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations), geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional Cévenne fault system in a context of present-day compressional tectonics

Les opérations de coopération transfrontalières : la concrétisation d’une politique de défense et de sécurité européenne ?

International audienc

L’enseignement religieux et le droit local en Alsace-Moselle

International audienc

L’évolution des rapports entre autorités déconcentrées et collectivités territoriales en matière de sécurité

International audienc

Le concept de sécurité commune : vers une mise en oeuvre effective ?

Issus du colloque éponyme organisé à Paris par le CERAP, Centre d'études et de recherches sur l'administration publique, l'Université Paris 13 et le GERCIE le 8 novembre 2013International audienc

Les grandes orientations du plan ministériel contre le harcèlement des femmes au sein des Armées : une avancée tangible ?

International audienc

Determination des activites thermodynamiques du bore et du carbone dans la phase carbure du systeme bore/carbone

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc