Rémi Jullien

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Volatile substances in the atmosphere surrounding gregarious locustsSchistocerca gregaria andLocusta migratoria were captured and investigated by combined gas chromatography-mass spectrometry. Three aromatic derivates have been identified: phenol, guaiacol, and veratrole. Their relative percentages differ for different ages and species. Behavioral tests(More)
A three-dimensional Voronoi tessellation of folded proteins is used to analyze geometrical and topological properties of a set of proteins. To each amino acid is associated a central point surrounded by a Voronoi cell. Voronoi cells describe the packing of the amino acids. Special attention is given to reproduction of the protein surface. Once the Voronoi(More)
The packing geometry of amino acids in folded proteins is analyzed via a modified Voronoï tessellation method which distinguishes bulk and surface. From a statistical analysis of the Voronoï cells over 40 representative proteins, it appears that the packings are in average similar to random packings of hard spheres encountered in condensed matter physics,(More)
We use classical molecular dynamics simulations to study the dynamics of sodium atoms in amorphous Na2O-4SiO2. We find that the sodium trajectories form a well connected network of pockets and channels. Inside these channels the motion of the atoms is not cooperative but rather given by independent thermally activated hops of individual atoms between the(More)
The experimental density dependence of gas (argon and nitrogen) permeability of partially densified silica aerogels in the Knudsen regime is quantitatively accounted for by a computer model. The model simulates both the structure of the sintered material and the random ballistic motion of a point particle inside its voids. The same model is also able to(More)
The cuticular hydrocarbons ofLocusta migratoria cinerascens—larvae and adults, males and females, gregarious and solitaries—have been investigated by combined gas chromatography-mass spectrometry. The hydrocarbons comprise 52–78% of the cuticular lipids and are divided inton-alkanes (28.7–47.3%), 3-, 4-, and 5-methylalkanes (11.3–15.8%), internally branched(More)
UNLABELLED Voro3D is an original easy-to-use tool, which provides a brand new point of view on protein structures through the three-dimensional (3D) Voronoi tessellations. To construct the Voronoi cells associated with each amino acid by a number of different tessellation methods, Voro3D uses a protein structure file in the PDB format as an input. After(More)
Genetics studies gave an insight into the evolutionary systematics of theS. americana complex. Chemical analysis and comparison of the cuticular hydrocarbons of five species of this complex (S. gregaria, cancellata,americana, piceifrons, andpallens) confirmed the species status previously established by hybridization and also revealed new elements. We have(More)
An extension of the Voronoi tessellation, the Laguerre polyhedral decomposition, is introduced and applied to the analysis of the packing geometry of amino-acids in folded proteins. This method considers an ensemble of points with different weights and therefore it is well suited for a geometrical analysis of a set of objects with a wide size distribution.(More)