Résumé : Dans cet article nous présentons une architecture pour la description et la recherche de documents manuscrits anciens. Nous utilisons une décomposition en Curvelets des images pour indexer les fragments linéaires de l’écriture. Appartenant à la famille des ondelettes, cette transformée nous permet d’avoir plusieurs niveaux de détails. Le schéma général consiste à analyser les orientati...

Successful insect development is achieved via appropriate fluctuation of ecdysteroid levels. When an insect's ecdysteroid level is disrupted, physiological and developmental defects occur. In the pupa of the silkworm, Bombyx mori, the rectal sac is an essential organ that operates as a repository for degraded ecdysteroids, and it can be distended by administration of 20-hydroxyecdysone (20E). O...

Il existait au Moyen-âge des pensées profondes et raffinées du choix social, surtout chez Ramon Llull, (ca 1232-1316) et Nicolaus Krebs, surnommé ‘de Cusa’ ou ‘Cusanus’ (1401-64). Deux règles fondamentales du choix social moderne, c'est-à-dire celles de Copeland (généralisation de la règle de Condorcet) et de Borda, ont été proposées par Llull et Cusanus plusieurs siècles avant l'«âge d'or» du ...

G-protein-coupled receptors (GPCRs) transmit extracellular signals across the cell membrane. GPCR kinases (GRKs) desensitize GPCR signals in the cell membrane. However, the role and mechanism of GRKs in the desensitization of steroid hormone signaling are unclear. In this study, we propose that GRK2 is phosphorylated by protein kinase C (PKC) in response to induction by the steroid hormone 20-h...

We studied the effects of the molting hormone 20-hydroxyecdysone (20E) on leg sensory-motor networks of the red swamp crayfish, Procambarus clarkii. The hormone was injected in isolated crayfish and network activity was analyzed 3 days after injection using electrophysiology on an in vitro preparation of the leg locomotor network. This 20E treatment deeply reduced motor activity, by affecting b...

The insect hormone 20-hydroxy-ecdysone (20E) peaks at different stages during the life cycle. The hormone signal is commonly transmitted by a nuclear receptor consisting of the ecdysone receptor (EcR) and Ultraspiracle (Usp, orthologous to vertebrate RXR). EcR:Usp then initiate the expression of a series of gene regulators that help mediate biological responses to the hormone. Here, we investig...

Olfactory information mediating sexual behavior is crucial for reproduction in many animals, including insects. In male moths, the macroglomerular complex (MGC) of the primary olfactory center, the antennal lobe (AL) is specialized in the treatment of information on the female-emitted sex pheromone. Evidence is accumulating that modulation of behavioral pheromone responses occurs through neuron...

SYNOPSIS. The regulation of the ecdysteroid-induced cascade of transcription factors by 20-hydroxyecdysone (20E) and juvenile hormone (JH) in the epidermis of the lepidopteran Manduca sexta is summarized. Both the levels and isoforms of the ecdysone receptor (EcR) and Ultraspiracle (USP) change during the molt. The 20E induction of MHR3, an orphan receptor that appears relatively late in the ca...

Résumé H. S. Klein et S. L. Engerman — Frets et mortalité dans la traite négrière vers Rio de Janeiro, 1825-1830. Une analyse systématique des documents maritimes et commerciaux pour cette période permet d'établir non seulement les points d'origine des esclaves et leur importance numérique relative, mais encore la mortalité en cours de route. Par rapport à la situation à la fin du XVIIIe siècle...