Cryopreservation of encapsulated apices of sugarcane : effect of freezing procedure and histology

SUMMARY: The effect of sucrose concentration during the pregrowth treatment and of the freezing procedure on the survival of encapsulated apices of 6 sugarcane varieties was investigated. The optimal sucrose concentration was 0.75M. Survival was noted with both rapid freezing by direct immersion in liquid nitrogen and slow freezing using a programmable freezer but it was generally higher &er rapid cooling. Important genotypic variation was observed for both parameters studied. Histological examination revealed that cells were slightly harmed during pregrowth and freezing. Apices could withstand freezing as a whole. Direct regrowth of cryopreserved apices occurred within 3 days after thawing

Plant regeneration from cultured immature inflorescences of coconut (Cocos nucifera L.) : evidence for somatic embryogenesis

Les inflorescences immatures de cocotier appartenant à 3 génotypes différents étaient cultivées sur un milieu solide renfermant du charbon actif (2 %) et des concentrations de 2,4 D comprises entre 1,5 et 3,5 x 10-4. Des cals globuleux blancs, formés à partir des méristèmes floraux immatures, dépendaient de l'âge de l'inflorescence et de la concentration en 2,4 D. L'acquisition de la compétence embryogène est décrite par l'histologie. Les embryons somatiques, présentants un axe bipolaire fonctionnel avec un méristème apical complètement différencié, sont présentés pour la première fois dans cet article. La maturation des embryons conduit à une régénération reproductible de cette plante récalcitrante #in vitro$. Des détails sont donnés sur les besoins en hormones exogènes pour l'acquisition de la compétence embryogène et la maturation des embryons. (Résumé d'auteur

The Coq Proof Assistant : A Tutorial : Version 6.1

Projet COQCoq is a proof assistant based on a higher-order logic allowing powerful definitions of functions. This document is a tutorial for the version V6.1 of Coq. This version is available by anonymous ftp at ftp.inria.fr:/INRIA/Projects/coq/V6.1 and ftp.ens-lyon.fr:/pub/LIP/COQ/V6.

The Coq Proof Assistant : A Tutorial : Version 7.2

Projet COQCoq is a proof assistant based on a higher-order logic. Coq allows to handle calculus mathematical assertions and to check mechanically proofs of these assertions. It helps to find formal proofs, and allows extraction of a certified program from the constructive proof of its formal specification. This document is a tutorial for the version V7.2 of Coq which is available from http://coq.inria.fr

The Coq Proof Assistant, A Tutorial, Version 5.10

Projet CO

Symmetric microwave potentials for interferometry with thermal atoms on a chip

International audienceA trapped atom interferometer involving state-selective adiabatic potentials with two microwave frequencies on a chip is proposed. We show that this configuration provides a way to achieve a high degree of symmetry between the two arms of the interferometer, which is necessary for coherent splitting and recombination of thermal (i.e., noncondensed) atoms. The resulting interferometer holds promise to achieve high contrast and long coherence time, while avoiding the mean-field interaction issues of interferometers based on trapped Bose-Einstein condensates