Topiramate in the treatment of severe myoclonic epilepsy in infancy

AbstractThe aim of this study was to assess the effectiveness of topiramate (TPM) as an add-on regimen in reducing seizure rate in a population sample of patients diagnosed with severe myoclonic epilepsy in infancy (SME). Eighteen patients were evaluated. The mean observation time was 10.5 months (range, 6–18 months). Seizure frequency and type were recorded. Topiramate was administered as an add-on regimen at a starting dose of 1 mg kg−1and titrated to a maximum of 6–8 mg per kg per day. Different escalation rates were used, mainly weekly or fortnightly increments of dose. Three patients (16.6%) became seizure free, and 10 (55.6%) had a >50% reduction in seizure frequency: six of them (22.2%) achieved a reduction greater than 75%. Side-effects were observed in nine patients , eight with a weekly titration schedule and one with a fortnightly schedule. TPM is effective as adjunctive therapy for SME. Side-effects were mild and transient, generally related to rapid dosage titration

L'impact des insectes parasites des graines sur les capacités de régénération naturelle des peuplements de cèdre de l'Atlas et de sapin pectiné en Languedoc-Roussillon

La régénération naturelle des peuplements forestiers est soumise à diverses contraintes environnementales, dont les insectes ravageurs des cônes et des graines. Depuis 2004, nous avons estimé l'impact de ces ravageurs dans 11 cédraies et 11 sapinières de la région Languedoc-Roussillon. Les résultats montrent que ces insectes peuvent causer des pertes importantes de graines qui participeraient sans cela à la régénération des peuplements. Les peuplements en mélange semblent plus infestés que les peuplements purs. Cette étude a aussi permis de mettre en évidence le transfert d'un ravageur du cèdre sur le sapin. Certaines mesures sanitaires et le maintien du suivi des populations de ravageurs sont préconisées pour mieux anticiper et limiter l'impact de ces insectes sur la régénération naturelle des peuplements

Formation of disclination lines near a free nematic interface

We have studied the nucleation and the physical properties of a -1/2 wedge disclination line near the free surface of a confined nematic liquid crystal. The position of the disclination line has been related to the material parameters (elastic constants, anchoring energy and favored anchoring angle of the molecules at the free surface). The use of a planar model for the structure of the director field (whose predictions have been contrasted to those of a fully three-dimensional model) has allowed us to relate the experimentally observed position of the disclination line to the relevant properties of the liquid crystals. In particular, we have been able to observe the collapse of the disclination line due to a temperature-induced anchoring angle transition, which has allowed us to rule out the presence of a real disclination line near the nematic/isotropic front in directional growth experiments. 61.30.Jf,61.30.G

Topological Defects and Interactions in Nematic Emulsions

Inverse nematic emulsions in which surfactant-coated water droplets are dispersed in a nematic host fluid have distinctive properties that set them apart from dispersions of two isotropic fluids or of nematic droplets in an isotropic fluid. We present a comprehensive theoretical study of the distortions produced in the nematic host by the dispersed droplets and of solvent mediated dipolar interactions between droplets that lead to their experimentally observed chaining. A single droplet in a nematic host acts like a macroscopic hedgehog defect. Global boundary conditions force the nucleation of compensating topological defects in the nematic host. Using variational techniques, we show that in the lowest energy configuration, a single water droplet draws a single hedgehog out of the nematic host to form a tightly bound dipole. Configurations in which the water droplet is encircled by a disclination ring have higher energy. The droplet-dipole induces distortions in the nematic host that lead to an effective dipole-dipole interaction between droplets and hence to chaining.Comment: 17 double column pages prepared by RevTex, 15 eps figures included in text, 2 gif figures for Fig. 1

Tuning bilayer twist using chiral counterions

From seashells to DNA, chirality is expressed at every level of biological structures. In self-assembled structures it may emerge cooperatively from chirality at the molecular scale. Amphiphilic molecules, for example, can form a variety of aggregates and mesophases that express the chirality of their constituent molecules at a supramolecular scale of micrometres (refs 1-3), Quantitative prediction of the large-scale chirality based on that at the molecular scale remains a largely unsolved problem. Furthermore, experimental control over the expression of chirality at the supramolecular level is difficult to achieve(4-7): mixing of different enantiomers usually results in phase separation(18). Here we present an experimental and theoretical description of a system in which chirality can be varied continuously and controllably ('tuned') in micrometre-scale structures. we observe the formation of twisted ribbons consisting of bilayers of gemini surfactants (two surfactant molecules covalently linked at their charged head groups). We find that the degree of twist and the pitch of the ribbons can be tuned by the introduction of opposite-handed chiral counterions in various proportions. This degree of control might be of practical value; for example, in the use of the helical structures as templates for helical crystallization of macromolecules(8,9).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62619/1/399566a0.pd