The Nymph Architect of the Cicada <em>Guyalna chlorogena</em>: Behaviours and Ecosystem

At the beginning of the last year of its larval life, the nymph of Guyalna chlorogena builds, from a vertical well, which is the result of a verticalization process from a deep horizontal gallery, a clay turret 20 to 40 cm high which appears as a regulating device of the physico-chemical conditions inside the burrow. The construction of the turret is remarkable for its finish. The nymph maintains, repairs and rebuilds it if necessary. It opens and closes it under certain circumstances. Before moulting, the nymph comes out at the top, opening it according to a set protocol and time schedule, using its chitins’ forelegs. The burrow is associated in a commensal relationship with arborescent Fabaceae species (of the Tachigali genus) through its nutrition mode, the suction of the elaborated sap in fine roots, close to the meristems

Present eternity : quests of temporality in the literary production of the &quot;extr&#234;me contemporain&quot; in France (The Writings of Dominique Fourcade and Emmanuel Hocquard)

The term \uab extr\ueame contemporain \ubb is an expression currently used by scholars to indicate the French literary production of the last 20 years. This term was used in a work of literature for the first time by the French poet Dominique Fourcade in 1986 (\uc9l\ue9gie L apostrophe E.C.) in reference to an epoch, but also to a new sense of experiencing time and space in the so-called \uab age of digital reproducibility \ubb. The aim of this paper is to consider how the change in temporal protocols due to the triumph of Big Optics (Paul Virilio) affects the sense of teleology (destiny) and the quest for experience in French contemporary poetry (in particular, in the genre of the elegy). Including both memory and anticipation, the \uab extr\ueame contemporain \ubb production seems to prefer the \u201ctime of now\u201d, Jetz-zeit in Benjamin\u2019s words, to past or testimony, and speaks to the present, whose responsibility is to give voice to a space where everything is simply allowed to happen

Dynamic NMR study of rotational isomerism in the carbanion of p-trifluoromethanesulfonylbenzyltriflone in aprotic solvents

Rotational isomerism in the conjugate carbanion of p-trifluoromethanesulfonylbenzyltriflone was studied by dynamic NMR spectroscopy (1H, 13C). Treatment of the experimental spectra affords the activation parameters of the processes. The activation enthalpies (48 kJ mol-1) for the rotational barrier around the CAr - C carbon- carbon bond are indicative of a relatively weak -order of this bond and are nearly identical in the three dipolar aprotic solvents studied, namely acetonitrile, dimethyl sulfoxide and acetone. Changes in the rates of the conformation exchange around the CAr - C bond are mainly a reflection of the solvent dependence of the entropy change (from almost 0 in acetonitrile, to -8 in DMSO and -13 J K-1 mol-1 in acetone). These data are discussed in relation to information on the electronic density distribution, as obtained from an analysis of the 13C chemical shift of the anion of the benzyltriflone

L'énergie à découvert

L'énergie est devenue une question vitale pour les sociétés, le citoyen, l'humanité tout entière. Sujet scientifique, économique, politique et écologique majeur, elle suscite des débats, parfois violents, sur les choix à faire aujourd'hui et leurs conséquences pour l'avenir des hommes et de la planète. Mais, alors que se tient le grand débat national sur la transition énergétique, comment se forger une opinion objective sans connaître les données scientifiques les plus complètes sur les potentiels et les limites de chaque source d'énergie ? Ce livre les met enfin à la disposition du public. L'énergie, qu'est-ce que c'est ? Quelles sont les grandes lois physiques qui la gouvernent ? Comment la produire, la transporter, la stocker ? Le solaire, la biomasse, l'éolien, l'hydraulique sont-ils des solutions alternatives suffisantes ? Et quelle part leur réserver à l'avenir ? Les nombreux articles de ce livre (près de 130) proposent au citoyen des outils pour se faire une opinion face à ces questions. Physiciens, chimistes, biologistes, géophysiciens, environnementalistes, géographes, économistes, y précisent, chiffres et schémas à l'appui, la place respective des énergies fossiles, du nucléaire et des énergies renouvelables. Au-delà, ils expliquent quelles sont les perspectives offertes par la science sur le mix énergétique, le problème du stockage, l'amélioration de nos usages de l'énergie, ses impacts environnementaux et sanitaires