11,377 research outputs found

    Method for Identifying Regulators of Protein-Advanced Glycation End Product (Protein-Age) Formation

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    The invention relates to methods for identifying compounds which affect cellular stress. In particular, the method relates to identifying compounds which inhibit protein advanced glycation end product formation, where the compounds are carbonyl scavengers which inhibit the formation. The assay involves combing the substance of interest with histone H1 and ADP-ribose, and then measuring fluorescence and protein cross linking. Various inhibitors of protein AGE glycation have been identified, using this assay

    Relativistic Acoustic Geometry

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    Sound wave propagation in a relativistic perfect fluid with a non-homogeneous isentropic flow is studied in terms of acoustic geometry. The sound wave equation turns out to be equivalent to the equation of motion for a massless scalar field propagating in a curved space-time geometry. The geometry is described by the acoustic metric tensor that depends locally on the equation of state and the four-velocity of the fluid. For a relativistic supersonic flow in curved space-time the ergosphere and acoustic horizon may be defined in a way analogous the non-relativistic case. A general-relativistic expression for the acoustic analog of surface gravity has been found.Comment: 14 pages, LaTe

    Large-N bounds on, and compositeness limit of, gauge and gravitational interactions

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    In a toy model of gauge and gravitational interactions in D≄4D \ge 4 dimensions, endowed with an invariant UV cut-off Λ\Lambda, and containing a large number NN of non-self-interacting matter species, the physical gauge and gravitational couplings at the cut-off, αg≡g2ΛD−4\alpha_g \equiv g^2 \Lambda^{D-4} and αG≡GNΛD−2\alpha_G \equiv G_N \Lambda^{D-2}, are shown to be bounded by appropriate powers of 1N{1\over N}. This implies that the infinite-bare-coupling (so-called compositeness) limit of these theories is smooth, and can even resemble our world. We argue that such a result, when extended to more realistic situations, can help avoid large-N violations of entropy bounds, solve the dilaton stabilization and GUT-scale problems in superstring theory, and provide a new possible candidate for quintessence.Comment: 8 pages, Latex, minor modifications in notations and reference

    Method and Use of α-Amino-ÎČ-Mercapto-Ethane Derivatives as Dicarbonyl Scavengers for Treatment of Conditions Resulting from Protein, Lipid, and DNA Damage

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    Methods of inhibiting damage to proteins, lipids, and DNA by the use of penicillamines and other α-amino-ÎČ,ÎČ-mercapto-ÎČ,ÎČ-dimethyl-ethane compounds as dicarbonyl scavengers is disclosed

    Black hole entropy: inside or out?

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    A trialogue. Ted, Don, and Carlo consider the nature of black hole entropy. Ted and Carlo support the idea that this entropy measures in some sense ``the number of black hole microstates that can communicate with the outside world.'' Don is critical of this approach, and discussion ensues, focusing on the question of whether the first law of black hole thermodynamics can be understood from a statistical mechanics point of view.Comment: 42 pages, contribution to proceedings of Peyresq

    Threshold configurations in the presence of Lorentz violating dispersion relations

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    A general characterization of lower and upper threshold configurations for two particle reactions is determined under the assumptions that the single particle dispersion relations E(p) are rotationally invariant and monotonic in p, and that energy and momentum are conserved and additive for multiple particles. It is found that at a threshold the final particle momenta are always parallel and the initial momenta are always anti-parallel. The occurrence of new phenomena not occurring in a Lorentz invariant setting, such as upper thresholds and asymmetric pair production thresholds, is explained, and an illustrative example is given.Comment: 5 pages, 3 figure

    Resonance NLS Solitons as Black Holes in Madelung Fluid

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    A new resonance version of NLS equation is found and embedded to the reaction-diffusion system, equivalent to the anti-de Sitter valued Heisenberg model, realizing a particular gauge fixing condition of the Jackiw-Teitelboim gravity. The space-time points where dispersion change the sign correspond to the event horizon, and the soliton solutions to the AdS black holes. The soliton with velocity bounded above describes evolution on the hyperboloid with nontrivial winding number and create under collisions the resonance states with a specific life time.Comment: Plain Tex, 12 pages, 6 figure

    Model of black hole evolution

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    From the postulate that a black hole can be replaced by a boundary on the apparent horizon with suitable boundary conditions, an unconventional scenario for the evolution emerges. Only an insignificant fraction of energy of order (mG)−1(mG)^{-1} is radiated out. The outgoing wave carries a very small part of the quantum mechanical information of the collapsed body, the bulk of the information remaining in the final stable black hole geometry.Comment: 9 pages, harvmac, 3 figures, minor addition

    Stochastically Fluctuating Black-Hole Geometry, Hawking Radiation and the Trans-Planckian Problem

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    We study the propagation of null rays and massless fields in a black hole fluctuating geometry. The metric fluctuations are induced by a small oscillating incoming flux of energy. The flux also induces black hole mass oscillations around its average value. We assume that the metric fluctuations are described by a statistical ensemble. The stochastic variables are the phases and the amplitudes of Fourier modes of the fluctuations. By averaging over these variables, we obtain an effective propagation for massless fields which is characterized by a critical length defined by the amplitude of the metric fluctuations: Smooth wave packets with respect to this length are not significantly affected when they are propagated forward in time. Concomitantly, we find that the asymptotic properties of Hawking radiation are not severely modified. However, backward propagated wave packets are dissipated by the metric fluctuations once their blue shifted frequency reaches the inverse critical length. All these properties bear many resemblences with those obtained in models for black hole radiation based on a modified dispersion relation. This strongly suggests that the physical origin of these models, which were introduced to confront the trans-Planckian problem, comes from the fluctuations of the black hole geometry.Comment: 32 page

    Model of black hole evolution

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    From the postulate that a black hole can be replaced by a boundary on the apparent horizon with suitable boundary conditions, an unconventional scenario for the evolution emerges. Only an insignificant fraction of energy of order (mG)−1(mG)^{-1} is radiated out. The outgoing wave carries a very small part of the quantum mechanical information of the collapsed body, the bulk of the information remaining in the final stable black hole geometry.Comment: 9 pages, harvmac, 3 figures, minor addition
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