Dynamics of a hyperbolic system that applies at the onset of the oscillatory instability

A real hyperbolic system is considered that applies near the onset of the oscillatory instability in large spatial domains. The validity of that system requires that some intermediate scales (large compared with the basic wavelength of the unstable modes but small compared with the size of the system) remain inhibited; that condition is analysed in some detail. The dynamics associated with the hyperbolic system is fully analysed to conclude that it is very simple if the coefficient of the cross-nonlinearity is such that , while the system exhibits increasing complexity (including period-doubling sequences, quasiperiodic transitions, crises) as the bifurcation parameter grows if ; if then the system behaves subcritically. Our results are seen to compare well, both qualitatively and quantitatively, with the experimentally obtained ones for the oscillatory instability of straight rolls in pure Rayleigh - Bénard convection

Stable self-similar blow-up dynamics for slightly L2L^2-supercritical generalized KdV equations

In this paper we consider the slightly $L^2$-supercritical gKdV equations $\partial_t u+(u_{xx}+u|u|^{p-1})_x=0$, with the nonlinearity $5<p<5+\varepsilon$ and $0<\varepsilon\ll 1$ . We will prove the existence and stability of a blow-up dynamic with self-similar blow-up rate in the energy space $H^1$ and give a specific description of the formation of the singularity near the blow-up time.Comment: 38 page

L’interprétationnisme pluraliste et la nature de l’oeuvre littéraire

Dans cet essai, nous voulons contribuer à poser les bases épistémologiques et ontologiques d’une approche composite de la théorie de l’interprétation que nous désignerons sous le nom d’« interprétationnisme pluraliste ». À l’encontre de l’intentionnalisme hypothétique, mais à l’instar de la théorie du patchwork dont il s’inspire, l’interprétationnisme pluraliste admet une variété de modes d’interprétations sans concéder de statut privilégié à aucun. Cette approche s’accorde avec la thèse de l’interprétation imputationnelle que l’on justifie sur la base d’une analyse de la nature et de la formation des concepts interprétatifs. Elle est aussi compatible avec un modèle tripartite de l’ontologie de l’oeuvre littéraire qui permet d’éviter les critiques habituelles soulevées contre l’interprétation imputationnelle, à savoir le singularisme et l’objection de la dissolution de l’oeuvre.In this essay, we want to contribute to lay down some epistemological and ontological bases for a composite view of the theory of interpretation that we are calling “pluralist interpretationism”. Contrary to hypothetical intentionalism, but like the patchwork theory from which it is derived, pluralist interpretationism recognizes a variety of modes of interpretation without conceding to any a privileged status. This view agrees with the thesis of imputationalist interpretation which can be justified by an analysis of the nature and formation of interpretive concepts. It is also compatible with a tridimensional model of the ontology of literary works that avoids the usual criticisms raised against interpretative imputationalist such as singularism and the reductio ad absurdum

Effects of soil insecticide treatments on northern corn rootworm, Diabrotica barberi [Coleoptera : Chrysomelidae] populations and on corn yield

Durant 3 ans, des essais au champ ont permis d'evaluer les effets de trois insecticides appliqués au sol lors des semis sur les populations de la chrysomèle des racines du maïs (Diabrotica barberi). Dans chacune des parcelles, une cage d'émergence a été placée au-dessus d'un plant de maïs (Zea mays) et les populations d'adultes ont été suivies hebdomadairement. Les dommages faits par les larves aux racines de maïs ont été évalués et le rendement en grains a été déterminé à la fin de la saison de croissance des plantes. Les traitements insecticides ont réduit significativement le nombre d'adultes émergeant durant la première année seulement. La force d'arrachage était reliée négativement au nombre d'adultes émergeant par plant. Chaque année le rendement en grains des parcelles traitées n'était pas significativement différent de celui des parcelles non traitées. Les traitements insecticides peuvent donc réduire le nombre d'adultes émergeant sans toutefois augmenter les rendements.A 3-yr field study was conducted to determine the effects of three soil applied insecticides on northern corn rootworm (Diabrotica barberi) populations. In each plot, an emergence cage was placed over a corn (Zea mays) plant, and adult populations were monitored weekly. Larval damage to corn roots was evaluated and corn yield was recorded at the end of the growing season. Insecticide treatments significantly reduced the number of emerging adults in the first yr, but no difference was observed in the following yr. Root strength was negatively correlated to the number of emerging adults per plant. Each yr, corn yields in treated plots did not differ significantly from yield in untreated plots, which suggests that insecticide treatments can reduce the number of emerging adults without increasing yields

La bibliothèque tiers-lieu

La bibliothèque troisième lieu joue un rôle structurant dans le développement des nouvelles bibliothèques en Scandinavie, en Angleterre ainsi qu\u27au Québec, si on considère que de nombreux projets se réfèrent à ce modèle. Comment, après examen des objections, inscrire ce concept dans la perspective du développement durable

Mitoparans: mitochondriotoxic cell penetrating peptides and novel inducers of apoptosis.

Acknowledgments The authors would like to thank Keith Holding at the University of Wolverhampton for his outstanding technical support. This work was supported in part by Samantha Dickson Brain Tumour Trust.Introduction: The amphipathic helical peptide mastoparan (MP; H-INLKALAALAKKIL-NH2) inserts into biological membranes to modulate the activity of heterotrimeric G proteins and other targets. Moreover, whilst cell free models of apoptosis demonstrate MP to facilitate mitochondrial permeability transition and release of apoptogenic cytochrome c, MP-induced death of intact cells has been attributed to its non-specific membrane destabilising properties (necrotic mechanisms). However, MP and related peptides are known to activate other signalling systems, including p42/p44 MAP kinases and could therefore, also modulate cell fate and specific apoptotic events. The ability of MP to facilitate mitochondrial permeability in cell free systems has lead to proposals that MP could be of utility in tumour therapeutics provided that it conferred features of cellular penetration and mitochondrial localization. We have recently reported that our highly potent amphipathic MP analogue mitoparan (mitP; [Lys5,8Aib10]MP; Aib = -aminoisobutyric acid) specifically promotes apoptosis of human cancer cells, as was confirmed by in situ TUNEL staining and activation of caspase-3. Moreover, we have also demonstrated that mitP penetrates plasma membranes and redistributes to co-localize with mitochondria. Complementary studies, using isolated mitochondria, further demonstrated that mitP, through co-operation with a protein of the permeability transition pore complex voltage-dependent anion channel (VDAC), induced swelling and permeabilization of mitochondria, leading to the release of the apoptogenic factor cytochrome c. An expanding field of peptide and cell penetrating peptide (CPP) research has focussed on the selective targeting of tumours by engineering constructs that incorporate cell-specific or tissue–specific address motifs. Peptidyl address motifs could enhance the selectivity of drug delivery whilst the improved cellular uptake offered by CPP enhances bioavailability. Thus and as a potential therapeutic strategy, we extended our findings to design target-specific mitP analogues. The integrin-specific address motif RGD and a Fas ligand mimetic WEWT were incorporated by N-terminal acylation of mitP to produce novel tandem-linked chimeric peptides

Experimental study of a liquid Xenon PET prototype module

A detector using liquid Xenon in the scintillation mode is studied for Positron Emission Tomography (PET). The specific design aims at taking full advantage of the liquid Xenon properties. It does feature a promising insensitive to any parallax effect. This work reports on the performances of the first LXe prototype module, equipped with a position sensitive PMT operating in the VUV range (178 nm).Comment: Proc. of the 7th International Workshops on Radiation Imaging Detectors (IWORID-7), Grenoble, France 4-7 July 200

The Mass Dependence of Star Formation Histories in Barred Spiral Galaxies

We performed a series of 29 gasdynamical simulations of disc galaxies, barred and unbarred, with various stellar masses, to study the impact of the bar on star formation history. Unbarred galaxies evolve very smoothly, with a star formation rate (SFR) that varies by at most a factor of three over a period of 2 Gyr. The evolution of barred galaxies is much more irregular, especially at high stellar masses. In these galaxies, the bar drives a substantial amount of gas toward the centre, resulting in a high SFR, and producing a starburst in the most massive galaxies. Most of the gas is converted into stars, and gas exhaustion leads to a rapid drop of star formation after the starburst. In massive barred galaxies (stellar mass M* > 2x10^10 Msun) the large amount of gas funnelled toward the centre is completely consumed by the starburst, while in lower-mass barred galaxies it is only partially consumed. Gas concentration is thus higher in lower-mass barred galaxies than it is in higher-mass ones. Even though unbarred galaxies funnelled less gas toward their centre, the lower SFR allows this gas to accumulate. At late times, the star formation efficiency is higher in barred galaxies than unbarred ones, enabling these galaxies to maintain a higher SFR with a smaller gas supply. Several properties, such as the global SFR, central SFR, or central gas concentration, vary monotonically with time for unbarred galaxies, but not for barred galaxies. Therefore one must be careful when comparing barred and unbarred galaxies that share one observational property, since these galaxies might be at very different stages of their respective evolution