Introduction

La place et le rôle des médias dans le fonctionnement social des démocraties occidentales constituent, à n’en pas douter, un terrain d’observation largement pris en compte par les sciences sociales. Les travaux sur ces questions se multiplient et cette multiplication n’est pas sans poser elle-même un certain nombre de questions. La conception de ce numéro est issue de certaines de ces interrogations et de la volonté des différents contributeurs – et de ceux de l’ouvrage qui suivra - de marque..

Relevant Spatial Scales of Chemical Variation in Aplysina aerophoba

Understanding the scale at which natural products vary the most is critical because it sheds light on the type of factors that regulate their production. The sponge Aplysina aerophoba is a common Mediterranean sponge inhabiting shallow waters in the Mediterranean and its area of influence in Atlantic Ocean. This species contains large concentrations of brominated alkaloids (BAs) that play a number of ecological roles in nature. Our research investigates the ecological variation in BAs of A. aerophoba from a scale of hundred of meters to thousand kilometers. We used a nested design to sample sponges from two geographically distinct regions (Canary Islands and Mediterranean, over 2500 km), with two zones within each region (less than 50 km), two locations within each zone (less than 5 km), and two sites within each location (less than 500 m). We used high-performance liquid chromatography to quantify multiple BAs and a spectrophotometer to quantify chlorophyll a (Chl a). Our results show a striking degree of variation in both natural products and Chl a content. Significant variation in Chl a content occurred at the largest and smallest geographic scales. The variation patterns of BAs also occurred at the largest and smallest scales, but varied depending on which BA was analyzed. Concentrations of Chl a and isofistularin-3 were negatively correlated, suggesting that symbionts may impact the concentration of some of these compounds. Our results underline the complex control of the production of secondary metabolites, with factors acting at both small and large geographic scales affecting the production of multiple secondary metabolites

La doctrine du doyen Bonnard sur le droit naturel

International audienceRésumé à veni

La doctrine du doyen Bonnard sur le droit naturel

International audienceRésumé à veni

L'utopie liturgique (la "Missa en si mineur" de Johann Sebastian Bach)

AIX-MARSEILLE1-BU Lettres (130012101) / SudocPARIS-EPHE 4 (751052333) / SudocSudocFranceF

Préface de Bernard Stiegler, Postface de Jean-Max Noyer

Comme depuis les commencements de l'Ecriture, l'Hypertextualité ne cesse de venir vers nous, dès l'émergence des villes ou des cités, 1 l'Hyperville ne cesse de venir à notre rencontre selon des formes et des devenirs très hétérogènes. L'Hyperville de Franck Cormerais n'est pas la mère de toutes les villes passées, présentes et à venir, mais une actualisation incarnation spécifique singulière de ce Virtuel qui donc nous précède, la ville contributive. Cette Hyperville à la fois déjà là sous des formes locales et modèles limités, se différencie d'autres actualisations en cours, d'autres incarnations associées à des économies politiques dominantes, à des manières de faire converger physique sociale et biopolitique pour définir des territoires urbains d'hypercontrôle des populations. Les diverses formes de " Smart cities" sont ici visées mais aussi des formes hybrides où sont tissés à la fois les forces et les énergies, les ressources et les peaux du monde, le tissage continue des êtres et des choses, des artefacts et des objets…

Insights on the particle-attached riverine archaeal community shifts linked to seasons and to multipollution during a Mediterranean extreme storm event

International audienceRivers are representative of the overall contamination found in their catchment area. Contaminant concentrations in watercourses depend on numerous factors including land use and rainfall events. Globally, in Mediterranean regions, rainstorms are at the origin of fluvial multipollution phenomena as a result of Combined Sewer Overflows (CSOs) and floods. Large loads of urban-associated microorganisms, including faecal bacteria, are released from CSOs which place public health - as well as ecosystems - at risk. The impacts of freshwater contamination on river ecosystems have not yet been adequately addressed, as is the case for the release of pollutant mixtures linked to extreme weather events. In this context, microbial communities provide critical ecosystem services as they are the only biological compartment capable of degrading or transforming pollutants. Through the use of 16S rRNA gene metabarcoding of environmental DNA at different seasons and during a flood event in a typical Mediterranean coastal river, we show that the impacts of multipollution phenomena on structural shifts in the particle-attached riverine bacteriome were greater than those of seasonality. Key players were identified via multivariate statistical modelling combined with network module eigengene analysis. These included species highly resistant to pollutants as well as pathogens. Their rapid response to contaminant mixtures makes them ideal candidates as potential early biosignatures of multipollution stress. Multiple resistance gene transfer is likely enhanced with drastic consequences for the environment and human-health, particularly in a scenario of intensification of extreme hydrological events