Thermal counting statistics in an atomic two-mode squeezed vacuum state

We measure the population distribution in one of the atomic twin beams generated by four-wave mixing in an optical lattice. Although the produced two-mode squeezed vacuum state is pure, each individual mode is described as a statistical mixture. We confirm the prediction that the particle number follows an exponential distribution when only one spatio-temporal mode is selected. We also show that this distribution accounts well for the contrast of an atomic Hong--Ou--Mandel experiment. These experiments constitute an important validation of our twin beam source in view of a future test of a Bell inequalities.Comment: SciPost submissio

Efficient click-addition sequence for polymer–polymer couplings

Controlled radical polymerization methods and click chemistry form a versatile toolbox for creating complex polymer architectures. However, the incompatibility between the functional groups required for click reactions and the reaction conditions of radical polymerization techniques often limits application. Here, we demonstrate how combining two complementary click reactions in a sequence circumvents compatibility issues. We employ isocyanate-amine addition on a polymer obtained by RAFT without purification, thus allowing us to work at exact equimolarity. The addition of commercially available amine-functional azido or strained alkyne compounds, yields orthogonally modified polymers, which can be coupled together in a subsequent strain promoted cycloaddition (SPAAC). The efficiency of this reaction sequence is demonstrated with different acrylate, methacrylate, and acrylamide polymers giving block copolymers in high yield. The resulting diblock copolymers remain active towards RAFT polymerization, thus allowing access to multiblock structures by simple chain extension. The orthogonality of the isocyanate-amine reaction, SPAAC and RAFT polymerization (both in terms of monomer and chain end groups) is a key advantage and offers access to functional and challenging polymer architectures without the need for stringent reaction conditions or laborious intermediate purifications

Poly(bromoethyl acrylate) : a reactive precursor for the synthesis of functional RAFT materials

Postpolymerization modification has become a powerful tool to create a diversity of functional materials. However, simple nucleophilic substitution reactions on halogenated monomers remains relatively unexplored. Here we report the synthesis of poly(bromoethyl acrylate) (pBEA) by reversible addition–fragmentation chain transfer (RAFT) polymerization to generate a highly reactive polymer precursor for postpolymerization nucleophilic substitution. RAFT polymerization of BEA generated well-defined homopolymers and block copolymers over a range of molecular weights. The alkylbromine-containing homopolymer and block copolymer precursors were readily substituted by a range of nucleophiles in good to excellent conversion under mild and efficient reaction conditions without the need of additional catalysts. The broad range of nucleophilic species that are compatible with this postmodification strategy enables facile synthesis of complex functionalities, from permanently charged polyanions to hydrophobic polythioethers to glycopolymers

La sécurité du jeu et le jeu de la sécurité : piratage, loi et politique publique

Le présent rapport est l’objet d’une étude du lien entre les organisations criminelles et le contrôle social dans le domaine de la criminalité informatique. D’abord, nous examinerons quelques attaques montées contre des appareils de jeu électronique. Ensuite, nous analyserons de quelle façon ces cyberattaques ont été commises et quelle est la capacité de l’État et du secteur industriel à les combattre. Enfin, nous comparerons nos conclusions à celles tirées d’autres études sur le piratage dans l’industrie des jeux de hasard et nous discuterons de l’importance de nos conclusions pour les systèmes d’application de la loi, de sécurité et de protection des consommateurs.This paper studies the relationship between criminal organization and social control in the area of computer crime. We examine a “cheat at play” scheme that hacked into electronic gambling machines. We focus on how these cyber-attacks were committed and on the ability of the state and the industry to control them. We compare and contrast our findings with the research on hacking and the gambling industry and conclude by discussing the implications that our research has for law enforcement, security and public policy

Maximum-likelihood models for mapping genetic markers showing segregation distortion : 2. F2 populations

Dans la génération F2, la sélection naturelle des gamètes et des zygotes peut affecter les linkages génétiques. Une équation mathématique qui prend toutes les probabibilités de linkage en compte est développée. L'intégration des marqueurs génétiques dominants et codominants permet d'obtenir une courbe de probabilité asymptotique. La comparaison de l'utilité et de la précision des modèles montre que la prise en compte des marqueurs dominants seuls ne donne pas assez d'information sur le cas de distorsions de ségrégation. L'estimation de la fraction de recombinaisons entre les marqueurs codominants est peu affectée par la sélection, ce qui n'est pas le cas pour les marqueurs dominant

Using genotyping-by-sequencing to understand Musa diversity

Poster presented at Plant and Animal Genome, PAG XXII. San Diego (USA), 11-15 Jan 201