893,003 research outputs found

    Functional Approach to Classical Yang-Mills Theories

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    Sometime ago it was shown that the operatorial approach to classical mechanics, pioneered in the 30's by Koopman and von Neumann, can have a functional version. In this talk we will extend this functional approach to the case of classical field theories and in particular to the Yang-Mills ones. We shall show that the issues of gauge-fixing and Faddeev-Popov determinant arise also in this classical formalism.Comment: 4 pages, Contribution to the Proceedings of the International Meeting "Quantum Gravity and Spectral Geometry" (Naples, July 2-7, 2001

    A New synthesis of triazolo[4,5-g]quinolines and unexpected ring reduced products by treatment with hydrazine hydrate

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    A new synthesis of the linear heterocycle 4-chloro-1H-triazolo[4,5-g]quinoline by reduction of the novel compound 4-chloro-1H-triazolo[4,5-g]quinoline-1-oxide is reported. Treatment of the latter with hydrazine hydrate in ethanol in a sealed steel vessel in the presence or not of palladised charcoal, under various conditions of both time and temperature, afforded some derivatives of both ring reduction and ring construction

    Serotonin system implication in L-DOPA-induced dyskinesia: from animal models to clinical investigations

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    In the recent years, the serotonin system has emerged as a key player in the induction of l-DOPA-induced dyskinesia (LID) in animal models of Parkinson's disease. In fact, serotonin neurons possess the enzymatic machinery able to convert exogenous l-DOPA to dopamine (DA), and mediate its vesicular storage and release. However, serotonin neurons lack a feedback control mechanism able to regulate synaptic DA levels. While in a situation of partial DA depletion spared DA terminals can buffer DA released from serotonin neurons, the progression of DA neuron degeneration impairs this protective mechanism, causing swings in synaptic DA levels and pulsatile stimulation of post-synaptic DA receptors. In line with this view, removal of serotonin neurons by selective toxin, or pharmacological silencing of their activity, produced complete suppression of LID in animal models of Parkinson's disease. In this article, we will revise the experimental evidence pointing to the important role of serotonin neurons in dyskinesia, and we will discuss the clinical implications. © 2014 Carta and Tronci

    Mapping Connectedness of Global Cities: α, β and γ tiers

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    An elaboration of data from a database in the form of an atlas. The atlas shows the categorization of world cities into α, β and γ tiers, based upon their international connectedness. From this visualization it emerges where each city is virtually oriented to other cities of the same level of inter-connectivity. The world map is configured as an archipelago, where each city appears utterly separated from its geographical surrounding and closer to other cities of the same level. The leading parameters for the new configuration are based on mutual connections, primarily in the global economic system. The atlas shows the world cities according to the GaWC categorization of 201
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