Libration driven elliptical instability

The elliptical instability is a generic instability which takes place in any rotating flow whose streamlines are elliptically deformed. Up to now, it has been widely studied in the case of a constant, non-zero differential rotation between the fluid and the elliptical distortion with applications in turbulence, aeronautics, planetology and astrophysics. In this letter, we extend previous analytical studies and report the first numerical and experimental evidence that elliptical instability can also be driven by libration, i.e. periodic oscillations of the differential rotation between the fluid and the elliptical distortion, with a zero mean value. Our results suggest that intermittent, space-filling turbulence due to this instability can exist in the liquid cores and sub-surface oceans of so-called synchronized planets and moons

Is social media transforming canadian electioneering? : Hybridity and online partisan strategies in the 2012 Quebec election

This article investigates the extent to which provincial political parties made use of social media in their strategy, organization and communication in order to achieve their electoral goals during the Quebec 2012 general election. Using data from a series of 19 interviews conducted with online strategists and campaign directors from the five leading parties active in the 2012 election, we identify the strategic objectives these organizations followed when developing their social media campaigns. The strategists' narratives reveal that social media became a central component of electioneering and that parties were carrying out, in various forms, hybrid campaigns that combined traditional and emergent communication technologies and employed both old and new types of organizational principles.Cet article examine dans quelle mesure les partis politiques provinciaux ont inclus les médias sociaux dans leur stratégie, l'organisation et la communication de campagne pour atteindre leurs objectifs lors des élections générales de 2012 au Québec. À l'aide des données provenant d'une série de 19 entrevues menées auprès de stratèges et de directeurs de campagne des cinq principaux partis lors de l'élection de 2012, nous relevons les objectifs stratégiques poursuivis par ces derniers dans l'élaboration de leurs campagnes numériques. Les propos des stratèges révèlent que les médias sociaux sont devenus un élément central de l'organisation électorale et que les partis menaient, sous diverses formes, des campagnes hybrides dans lesquelles les technologies de communication traditionnelles et émergentes ainsi que d'anciens et de nouveaux types de principes organisationnels étaient combinés

Recherches sur la motricité du rumen chez les petits Ruminants. II - Relation entre la motricité et la glycémie

Le Bars Henri, Nitescu R., Simonnet Henri. Recherches sur la motricité du rumen chez les petits Ruminants. II) Relation entre la motricité et la glycémie. In: Bulletin de l'Académie Vétérinaire de France tome 106 n°7, 1953. pp. 351-360

Recherches sur la motricité du rumen chez les petits ruminants III. — Action de l’adrénaline

Le Bars Henri, Nitescu R., Simonnet Henri. Recherches sur la motricité du rumen chez les petits Ruminants. III) Action de l’adrénaline. In: Bulletin de l'Académie Vétérinaire de France tome 106 n°8, 1953. pp. 445-447

Recherches sur la motricité du rumen chez les petits ruminants I. Motricité normale

Le Bars Henri, Nitescu N., Simonnet Henri. Recherches sur la motricité du rumen chez les petits Ruminants. I) Motricité normale. In: Bulletin de l'Académie Vétérinaire de France tome 106 n°6, 1953. pp. 287-300

Tilt-over mode in a precessing triaxial ellipsoid

The tilt-over mode in a precessing triaxial ellipsoid is studied theoretically and numerically. Inviscid and viscous analytical models previously developed for the spheroidal geometry by Poincar\'e [Bull. Astr. 27, 321 (1910)] and Busse [J. Fluid Mech., 33, 739 (1968)] are extended to this more complex geometry, which corresponds to a tidally deformed spinning astrophysical body. As confirmed by three-dimensional numerical simulations, the proposed analytical model provides an accurate description of the stationary flow in an arbitrary triaxial ellipsoid, until the appearance at more vigorous forcing of time dependent flows driven by tidal and/or precessional instabilities.Comment: http://link.aip.org/link/doi/10.1063/1.350435

A novel behavioral fish model of nociception for testing analgesics

Pain is a major symptom in many medical conditions, and often interferes significantly with a person's quality of life. Although a priority topic in medical research for many years, there are still few analgesic drugs approved for clinical use. One reason is the lack of appropriate animal models that faithfully represent relevant hallmarks associated with human pain. Here we propose zebrafish (Danio rerio) as a novel short-term behavioral model of nociception, and analyse its sensitivity and robustness. Firstly, we injected two different doses of acetic acid as the noxious stimulus. We studied individual locomotor responses of fish to a threshold level of nociception using two recording systems: a video tracking system and an electric biosensor (the MOBS system). We showed that an injection dose of 10% acetic acid resulted in a change in behavior that could be used to study nociception. Secondly, we validated our behavioral model by investigating the effect of the analgesic morphine. In time-course studies, first we looked at the dose-response relationship of morphine and then tested whether the effect of morphine could be modulated by naloxone, an opioid antagonist. Our results suggest that a change in behavioral responses of zebrafish to acetic acid is a reasonable model to test analgesics. The response scales with stimulus intensity, is attenuated by morphine, and the analgesic effect of morphine is blocked with naloxone. The change in behavior of zebrafish associated with the noxious stimulus can be monitored with an electric biosensor that measures changes in water impedance. © 2011 by the authors; licensee MDPI, Basel, Switzerland

Field theory description of vacuum replicas

In this paper we develop a systematic quantum field theory based approach to the vacuum replica recently found to exist in effective low energy models in hadronic physics. A local operator creating the replica state is constructed explicitly. We show that a new effective quark-quark force arises in result of replica existence. Phenomenological implications of such a force are also briefly discussed.Comment: RevTeX4, 23 pages, 4 Postscript figures, uses epsfig.sty, to appear in Phys.Rev.