Sur les immeubles hyperboliques (On hyperbolic buildings)

The aim of this paper is to give a geometric approach to Tits' amalgam method to construct buildings and to initiate a study of hyperbolic buildings, i.e. whose types are reflexion systems of the real hyperbolic space. We construct lots of examples and study their cohomology at infinity. We construct CAT(–1) polyhedral complexes having big discrete parabolic groups of isometries.     

New access to lipo-chitooligosaccharide nodulation factors

Sulfonated and non-sulfonated lipo-chitooligosaccharides involved in Sinorhizobium meliloti-legume symbiosis are efficiently obtained on a multi mg scale by a 2-step procedure combining biotechnological and chemical approaches.     

Large-scale finite-wavelength modulation within turbulent shear flows

We show that turbulent "spirals" and "spots" observed in Taylor-Couette and plane Couette flow correspond to a turbulence-intensity modulated finite-wavelength pattern which in every respect fits the phenomenology of coupled noisy Ginzburg-Landau (amplitude) equations with noise. This suggests the existence of a long-wavelength instability of the homogeneous turbulence regime.     

Convenient Access to Fluorescent Probes by Chemoselective Acylation of Hydrazinopeptides: Application to the Synthesis of the First Far‐Red Ligand for Apelin Receptor Imaging

Herein, we develop a convenient method to facilitate the solution‐phase fluorescent labelling of peptides based on the chemoselective acylation of α‐hydrazinopeptides. This approach combines the advantages of using commercially available amine‐reactive dyes and very mild conditions, which are fully compatible with the chemical sensitivity of the dyes. The usefulness of this approach was demonstrated by the labelling of apelin‐13 peptide. Various fluorescent probes were readily synthesized, enabling the rapid optimization of their affinities for the apelin receptor. Thus, the first far‐red fluorescent ligand with sub‐nanomolar affinity for the apelin receptor was characterized and shown to track the receptor efficiently in living cells by fluorescence confocal microscopy.     

Population inversion in a single InGaAs quantum dot using the method of adiabatic rapid passage

Preparation of a specific quantum state is a required step for a variety of proposed quantum applications. We report an experimental demonstration of optical quantum state inversion in a single semiconductor quantum dot using adiabatic rapid passage. This method is insensitive to variation in the optical coupling in contrast with earlier work based on Rabi oscillations. We show that when the pulse power exceeds a threshold for inversion, the final state is independent of power. This provides a new tool for preparing quantum states in semiconductor dots and has a wide range of potential uses.     

Extensive and subextensive chaos in globally coupled dynamical systems

Using a combination of analytical and numerical techniques, we show that chaos in globally coupled identical dynamical systems, whether dissipative or Hamiltonian, is both extensive and subextensive: their spectrum of Lyapunov exponents is asymptotically flat (thus extensive) at the value λ(0) given by a single unit forced by the mean field, but sandwiched between subextensive bands containing typically O(logN) exponents whose values vary as λ?λ(∞)+c/logN with λ(∞)≠λ(0).     

Spectrometrie de Masse des Epoxydes Phenyles—II

The fragmentation of aromatic epoxides proceeds either directly through loss of one molecule of aldehyde or ketone which leads to a symmetrical ion, or through rearrangement of the molecular ion into the isomeric carbonyl radical ion. Substituents on the aromatic ring have a marked influence on the fragmentation.