294 research outputs found

    Wavelet transform modulus maxima based fractal correlation analysis

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    The wavelet transform modulus maxima (WTMM) used in the singularity analysis of one fractal function is extended to study the fractal correlation of two multifractal functions. The technique is developed in the framework of joint partition function analysis (JPFA) proposed by Meneveau et al. [1] and is shown to be equally effective. In addition, we show that another leading approach developed for the same purpose, namely, relative multifractal analysis, can be considered as a special case of JPFA at a particular parameter setting.Comment: 18 pgs, 5 fig

    Self Organized Scale-Free Networks from Merging and Regeneration

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    We consider the self organizing process of merging and regeneration of vertices in complex networks and demonstrate that a scale-free degree distribution emerges in a steady state of such a dynamics. The merging of neighbor vertices in a network may be viewed as an optimization of efficiency by minimizing redundancy. It is also a mechanism to shorten the distance and thus decrease signaling times between vertices in a complex network. Thus the merging process will in particular be relevant for networks where these issues related to global signaling are of concern

    On kaonic hydrogen. Quantum field theoretic and relativistic covariant approach

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    We study kaonic hydrogen, the bound K^-p state A_(Kp). Within a quantum field theoretic and relativistic covariant approach we derive the energy level displacement of the ground state of kaonic hydrogen in terms of the amplitude of K^-p scattering for arbitrary relative momenta. The amplitude of low-energy K^-p scattering near threshold is defined by the contributions of three resonances Lambda(1405), Lambda(1800) and Sigma^0(1750) and a smooth elastic background. The amplitudes of inelastic channels of low-energy K^-p scattering fit experimental data on near threshold behaviour of the cross sections and the experimental data by the DEAR Collaboration. We use the soft-pion technique (leading order in Chiral Perturbation Theory) for the calculation of the partial width of the radiative decay of pionic hydrogen A_(pi p) -> n + gamma and the Panofsky ratio. The theoretical prediction for the Panofsky ratio agrees well with experimental data. We apply the soft-kaon technique (leading order in Chiral Perturbation Theory) to the calculation of the partial widths of radiative decays of kaonic hydrogen A_(Kp) -> Lambda^0 + gamma and A_(Kp) -> Sigma^0 + gamma. We show that the contribution of these decays to the width of the energy level of the ground state of kaonic hydrogen is less than 1%.Comment: 33 pages, 1 figure, latex, References are adde

    Serum S100A8/A9 and S100A12 Levels in Children With Polyarticular Forms of Juvenile Idiopathic Arthritis: Relationship to Maintenance of Clinically Inactive Disease During Anti–Tumor Necrosis Factor Therapy and Occurrence of Disease Flare After Discontinuation of Therapy

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    © 2018, American College of Rheumatology Objective: To determine the relationship between serum levels of S100A8/A9 and S100A12 and the maintenance of clinically inactive disease during anti–tumor necrosis factor (anti-TNF) therapy and the occurrence of disease flare following withdrawal of anti-TNF therapy in patients with polyarticular forms of juvenile idiopathic arthritis (JIA). Methods: In this prospective, multicenter study, 137 patients with polyarticular-course JIA whose disease was clinically inactive while receiving anti-TNF therapy were enrolled. Patients were observed for an initial 6-month phase during which anti-TNF treatment was continued. For those patients who maintained clinically inactive disease over the 6 months, anti-TNF was withdrawn and they were followed up for 8 months to assess for the occurrence of flare. Serum S100 levels were measured at baseline and at the time of anti-TNF withdrawal. Spearman\u27s rank correlation test, Mann-Whitney U test, Kruskal-Wallis test, receiver operating characteristic (ROC) curve, and Kaplan-Meier survival analyses were used to assess the relationship between serum S100 levels and maintenance of clinically inactive disease and occurrence of disease flare after anti-TNF withdrawal. Results: Over the 6-month initial phase with anti-TNF therapy, the disease state reverted from clinically inactive to clinically active in 24 (18%) of the 130 evaluable patients with polyarticular-course JIA; following anti-TNF withdrawal, 39 (37%) of the 106 evaluable patients experienced a flare. Serum levels of S100A8/A9 and S100A12 were elevated in up to 45% of patients. Results of the ROC analysis revealed that serum S100 levels did not predict maintenance of clinically inactive disease during anti-TNF therapy nor did they predict disease flare after treatment withdrawal. Elevated levels of S100A8/A9 were not predictive of the occurrence of a disease flare within 30 days, 60 days, 90 days, or 8 months following anti-TNF withdrawal, and elevated S100A12 levels had a modest predictive ability for determining the risk of flare within 30, 60, and 90 days after treatment withdrawal. Serum S100A12 levels at the time of anti-TNF withdrawal were inversely correlated with the time to disease flare (r = −0.36). Conclusion: Serum S100 levels did not predict maintenance of clinically inactive disease or occurrence of disease flare in patients with polyarticular-course JIA, and S100A12 levels were only moderately, and inversely, correlated with the time to disease flare

    Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

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    We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η\eta|<0.8) and transverse momentum range 0.2< pTp_{\rm T}< 5.0 GeV/cc. The elliptic flow signal v2_2, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ±\pm 0.002 (stat) ±\pm 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v2(pT)_2(p_{\rm T}) reaches a maximum of 0.2 near pTp_{\rm T} = 3 GeV/cc. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

    The impact of solar and atmospheric parameter uncertainties on the measurement of θ13\theta_{13} and δ\delta

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    We present in this paper the analysis of the measurement of the unknown PMNS parameters θ13\theta_{13} and δ\delta at future LBL facilities performing complete three parameters fits, each time fully including in the fit one of the atmospheric and solar oscillation parameters within its present (future) error. We show that, due to the presence of degeneracies, present uncertainties on θ23\theta_{23} and Δm232\Delta m^2_{23} worsen significantly the precision on (θ13\theta_{13},δ\delta) at future LBL experiments. Only if a precision on the atmospheric parameters at least similar to what expected at T2K-I is reached, then the sensitivities to θ13\theta_{13} and δ\delta that have been presented in the literature for many facilities (where θ23\theta_{23} and Δm232\Delta m^2_{23} are generally considered as fixed external inputs) can indeed be almost recovered.On the other hand, the impact on this measurement of the uncertainties on the solar parameters, θ12\theta_{12} and Δm122\Delta m^2_{12} is already negligible. Our analysis has been performed using three reference setups: the SPL Super-Beam and the standard low-γ\gamma β\beta-Beam, both aiming toward a Mton Water \v{C}erenkov detector located at L=130 km; the 50 GeV Neutrino Factory with a 40 kton Magnetized Iron Detector to look for the ``golden channel'' νeνμ\nu_e \to \nu_\mu with baseline L=3000 km and a 4 kton Emulsion Cloud Chamber to look for the ``silver channel'' νeντ\nu_e \to \nu_\tau with baseline L=732 km.Comment: 42 pages, 64 figures. Comments added, final version to appear in EPJ

    Equilibrium configurations of two charged masses in General Relativity

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    An asymptotically flat static solution of Einstein-Maxwell equations which describes the field of two non-extreme Reissner - Nordstr\"om sources in equilibrium is presented. It is expressed in terms of physical parameters of the sources (their masses, charges and separating distance). Very simple analytical forms were found for the solution as well as for the equilibrium condition which guarantees the absence of any struts on the symmetry axis. This condition shows that the equilibrium is not possible for two black holes or for two naked singularities. However, in the case when one of the sources is a black hole and another one is a naked singularity, the equilibrium is possible at some distance separating the sources. It is interesting that for appropriately chosen parameters even a Schwarzschild black hole together with a naked singularity can be "suspended" freely in the superposition of their fields.Comment: 4 pages; accepted for publication in Phys. Rev.

    Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV

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    Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at sNN\sqrt{s_{_{\rm NN}}} = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in η<0.8|\eta|<0.8 and 0.3<pT<200.3 < p_T < 20 GeV/cc are compared to the expectation in pp collisions at the same sNN\sqrt{s_{\rm NN}}, scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor RAAR_{\rm AA}. The result indicates only weak medium effects (RAAR_{\rm AA} \approx 0.7) in peripheral collisions. In central collisions, RAAR_{\rm AA} reaches a minimum of about 0.14 at pT=6p_{\rm T}=6-7GeV/cc and increases significantly at larger pTp_{\rm T}. The measured suppression of high-pTp_{\rm T} particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
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