2,753 research outputs found

    Study of a navigation and traffic control technique employing satellites. Volume 3 - User hardware Interim report

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    User hardware configurations and requirements for navigation and air traffic control technique using satellite

    Glucocorticoid receptor action in metabolic and neuronal function [version 1; referees: 3 approved]

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    Glucocorticoids via the glucocorticoid receptor (GR) have effects on a variety of cell types, eliciting important physiological responses via changes in gene expression and signaling. Although decades of research have illuminated the mechanism of how this important steroid receptor controls gene expression using in vitro and cell culture–based approaches, how GR responds to changes in external signals in vivo under normal and pathological conditions remains elusive. The goal of this review is to highlight recent work on GR action in fat cells and liver to affect metabolism in vivo and the role GR ligands and receptor phosphorylation play in calibrating signaling outputs by GR in the brain in health and disease. We also suggest that both the brain and fat tissue communicate to affect physiology and behavior and that understanding this “brain-fat axis” will enable a more complete understanding of metabolic diseases and inform new ways to target them

    An analytical model for bore-driven run-up

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    We use a hodograph transformation and a boundary integral method to derive a new analytical solution to the shallow-water equations describing bore-generated run-up on a plane beach. This analytical solution differs from the classical Shen-Meyer runup solution in giving significantly deeper and less asymmetric swash flows, and also by predicting the inception of a secondary bore in both the backwash and the uprush in long surf. We suggest that this solution provides a significantly improved model for flows including swash events and the run-up following breaking tsunamis

    Study of a navigation and traffic control technique employing satellites. Volume 5 - Addendum. Traffic control data links Final report

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    Data links for air traffic control capability by satellites of NAVSTAR syste

    The applications of satellites to communications, navigation and surveillance for aircraft operating over the contiguous United States. Volume 1 - Technical report

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    Satellite applications to aircraft communications, navigation, and surveillance over US including synthesized satellite network and aircraft equipment for air traffic contro

    Coincidence of length spectra does not imply isospectrality

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    Penrose--Lifshits mushrooms are planar domains coming in nonisometric pairs with the same geodesic length spectrum. Recently S. Zelditch raised the question whether such billiards also have the same eigenvalue spectrum for the Dirichlet Laplacian (conjecturing ``no''). Here we show that generically (in the class of smooth domains) the two members of a mushroom pair have different spectra.Comment: 8 pages, 5 figure

    Relic Radiation from an Evaporating Black Hole

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    We present a non-string-theoretic calculation of the microcanonical entropy of relic integer-spin Hawking radiation -- at fixed total energy EE. The only conserved macroscopic quantity is the total energy EE (the total energy of the relic radiation). Data for a boundary-value approach, with massless, integer-spin perturbations, are set on initial and final space-like hypersurfaces. In the resulting 1-dimensional statistical-mechanics problem, the real part of the (complex) time separation at spatial infinity, T=Texp(iδ),δ>0T = {\mid}T{\mid}\exp(-i\delta), \delta >0, is the variable conjugate to the total energy. We count the number of weak-field configurations on the final space-like hypersurface with energy EE. One recovers the Cardy formula and the Bekenstein-Hawking entropy, if Re(T) is of the order of the black-hole life- time, leading to a statistical interpretation of black-hole entropy. The microcanonical entropy includes a logarithmic correction to the black-hole area law, which is {\it universal} (independent of black-hole parameters). Here, the discreteness of the energy levels is crucial. This approach is compared with that of string theory for the transition to the fundamental-string r\'egime in the final stages of evaporation. The squared coupling, g2g^2, regulating the transition to a highly-excited string state and {\it vice versa}, can be related to the angle, δ\delta, of complex-time rotation above. The strong-coupling r\'egime corresponds to a Euclidean black hole, while the physical limit of a Lorentzian space-time (as δ0+ \delta \to 0_+) corresponds to the weak-coupling r\'egime. This resembles the transition to a highly-excited string-like state which subsequently decays into massless particles, thereby avoiding the naked singularity.Comment: To appear in International Journal of Modern Physics

    Liouville field theory with heavy charges. II. The conformal boundary case

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    We develop a general technique for computing functional integrals with fixed area and boundary length constraints. The correct quantum dimensions for the vertex functions are recovered by properly regularizing the Green function. Explicit computation is given for the one point function providing the first one loop check of the bootstrap formula.Comment: LaTeX 26 page

    Time dependence of Bragg forward scattering and self-seeding of hard x-ray free-electron lasers

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    Free-electron lasers (FELs) can now generate temporally short, high power x-ray pulses of unprecedented brightness, even though their longitudinal coherence is relatively poor. The longitudinal coherence can be potentially improved by employing narrow bandwidth x-ray crystal optics, in which case one must also understand how the crystal affects the field profile in time and space. We frame the dynamical theory of x-ray diffraction as a set of coupled waves in order to derive analytic expressions for the spatiotemporal response of Bragg scattering from temporally short incident pulses. We compute the profiles of both the reflected and forward scattered x-ray pulses, showing that the time delay of the wave τ\tau is linked to its transverse spatial shift Δx\Delta x through the simple relationship Δx=cτcotθ\Delta x = c\tau \cot\theta, where θ\theta is the grazing angle of incidence to the diffracting planes. Finally, we apply our findings to obtain an analytic description of Bragg forward scattering relevant to monochromatically seed hard x-ray FELs.Comment: 11 pages, 6 figure

    Medical information prior to invasive medical procedures in otorhinolaryngology–head and neck surgery in France

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    SummaryBased on a review of the medical literature (PubMed database, keywords: medical information, informed consent), the authors analyse the main medicolegal aspects concerning the patient information that must be provided in France prior to any invasive diagnostic or therapeutic medical procedures in otorhinolaryngology head and neck surgery, as well as the patient's perception and recall of the information provided, the quality of the information provided and problems encountered in providing this information. In the light of this review, several solutions are recommended to improve this essential phase prior to obtaining the patient's informed consent
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