301 research outputs found

    Trace initial interaction from final state observable in relativistic heavy ion collisions

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    In order to trace the initial interaction in ultra-relativistic heavy ion collision in all azimuthal directions, two azimuthal multiplicity-correlation patterns -- neighboring and fixed-to-arbitrary angular-bin correlation patterns -- are suggested. From the simulation of Au + Au collisions at 200 GeV by using the Monte Carlo models RQMD with hadron re-scattering and AMPT with and without string melting, we observe that the correlation patterns change gradually from out-of-plane preferential one to in-plane preferential one when the centrality of collision shifts from central to peripheral, meanwhile the anisotropic collective flow v_2 keeps positive in all cases. This regularity is found to be model and collision energy independent. The physics behind the two opposite trends of correlation patterns, in particular, the presence of out-of-plane correlation patterns at RHIC energy, are discussed.Comment: 5pages, 4figure

    On Holographic Dual of the Dyonic Reissner-Nordstr\"om Black Hole

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    It is shown that the hidden conformal symmetry, namely SO(2,2)SL(2,R)L×SL(2,R)RSO(2,2) \sim SL(2,R)_L \times SL(2,R)_R symmetry, of the non-extremal dyonic Reissner-Nordstr\"om black hole can be probed by a charged massless scalar field at low frequencies. The existence of such hidden conformal symmetry suggests that the field theory holographically dual to the 4D Reissner-Nordstr\"om black hole indeed should be a 2D CFT. Although the associated AdS3_3 structure does not explicitly appear in the near horizon geometry, the primary parameters of the dual CFT2_2 can be exactly obtained without the necessity of embedding the 4D Reissner-Nordstr\"om black hole into 5D spacetime. The duality is further supported by comparing the absorption cross sections and real-time correlators obtained from both the CFT and the gravity sides.Comment: 18 pages, no figure, typos correcte

    Twofold Hidden Conformal Symmetries of the Kerr-Newman Black Hole

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    In this paper, we suggest that there are two different individual 2D CFTs holographically dual to the Kerr-Newman black hole, coming from the corresponding two possible limits --- the Kerr/CFT and Reissner-Nordstr\"om/CFT correspondences, namely there exist the Kerr-Newman/CFTs dualities. A probe scalar field at low frequencies turns out can exhibit two different 2D conformal symmetries (named by JJ- and QQ-pictures, respectively) in its equation of motion when the associated parameters are suitably specified. These twofold dualities are supported by the matchings of entropies, absorption cross sections and real time correlators computed from both the gravity and the CFT sides. Our results lead to a fascinating "microscopic no hair conjecture" --- for each macroscopic hair parameter, in additional to the mass of a black hole in the Einstein-Maxwell theory, there should exist an associated holographic CFT2_2 description.Comment: 21 pages, 1 figure, typos correcte

    ESTIMATION IN A PROPORTIONAL HAZARD MODEL FOR SEMI-MARKOV COUNTING PROCESS

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    Abstract: Estimation is studied in a regression model for counting processes whose baseline intensity processes are of semi-Markov form. Asymptotic normality is established for a Breslow-type estimator of the cumulative baseline hazard for each gap time of the counting process

    Synthesis and properties of novel soluble fluorinated polyamides containing pyridine and sulfone moieties

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    AbstractA new diamine containing pyridine and trifluoromethylphenyl groups, 4-(4-trifluoromethylphenyl)-2,6-bis(4-aminophenyl)pyridine, was synthesized and used in the preparation of the fluorinated polyamides containing pyridine and sulfone moieties with inherent viscosities of 0.70–1.06dLg−1 by the low temperature polycondensation with 4,4′-sulfonyl dibenzoyl chloride, 4,4′-[sulfonyl bis(4-phenyleneoxy)]dibenzoyl chloride, 3,3′-[sulfonyl bis(4-phenyleneoxy)]dibenzoyl chloride and 4,4′-[sulfonyl bis(2,6-dimethyl-1,4-phenyleneoxy)]dibenzoyl chloride in N,N-dimethylacetamide (DMAc) solution containing pyridine, respectively. All the polymers are amorphous and readily soluble in organic solvents such as DMAc, N-methyl-2-pyrrolidinone (NMP), N,N-dimethylformamide, dimethyl sulfoxide, pyridine (Py), and tetrahydrofuran at room temperature. The resulting polymers showed glass transition temperatures between 280 and 318°C and 10% weight loss temperatures ranging from 485°C to 516°C, and char yields at 800°C higher than 50% in nitrogen. All polymers could be casted into transparent, flexible and strong films from DMAc solutions with tensile strengths of 72–81MPa, elongations at break of 12–15%, and tensile moduli of 1.8–2.1GPa. These polymers had low dielectric constants of 3.40–3.51 (1MHz), low moisture absorption in the range of 1.08–1.28%, and high transparency with an ultraviolet–visible absorption cut-off wavelength in the 374–382nm range

    Levy Stability Index from Multifractal Spectrum

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    A method for extracting the Levy stability index μ\mu from the multi-fractal spectrum f(α)f(\alpha) in high energy multiparticle production is proposed. This index is an important parameter, characterizing the non-linear behaviour of dynamical fluctuations in high energy collisions. Using the random cascading α\alpha model as example, the validity of this method is tested. It is shown that this method, basing on a linear fit, is consistent with and more accurate than the usual method of fitting the ratio of qqth to 2nd order multi-fractal (R\'enyi) dimensions to the Peschanski formula.Comment: 7 pages 4 PS figures Record-No: HZPP-980

    Neuropeptide Y-mediated sex- and afferent-specific neurotransmissions contribute to sexual dimorphism of baroreflex afferent function

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    BACKGROUND: Molecular and cellular mechanisms of neuropeptide-Y (NPY)-mediated gender-difference in blood pressure (BP) regulation are largely unknown. METHODS: Baroreceptor sensitivity (BRS) was evaluated by measuring the response of BP to phenylephrine/nitroprusside. Serum NPY concentration was determined using ELISA. The mRNA and protein expression of NPY receptors were assessed in tissue and single-cell by RT-PCR, immunoblot, and immunohistochemistry. NPY was injected into the nodose while arterial pressure was monitored. Electrophysiological recordings were performed on nodose neurons from rats by patch-clamp technique. RESULTS: The BRS was higher in female than male and ovariectomized rats, while serum NPY concentration was similar among groups. The sex-difference was detected in Y1R, not Y2R protein expression, however, both were upregulated upon ovariectomy and canceled by estrogen replacement. Immunostaining confirmed Y1R and Y2R expression in myelinated and unmyelinated afferents. Single-cell PCR demonstrated that Y1R expression/distribution was identical between A- and C-types, whereas, expressed level of Y2R was ~15 and ~7 folds higher in Ah- and C-types than A-types despite similar distribution. Activation of Y1R in nodose elevated BP, while activation of Y2R did the opposite. Activation of Y1R did not alter action potential duration (APD) of A-types, but activation of Y2R- and Y1R/Y2R in Ah- and C-types frequency-dependently prolonged APD. N-type ICa was reduced in A-, Ah- and C-types when either Y1R, Y2R, or both were activated. The sex-difference in Y1R expression was also observed in NTS. CONCLUSIONS: Sex- and afferent-specific expression of Neuropeptide-Y receptors in baroreflex afferent pathway may contribute to sexual-dimorphic neurocontrol of BP regulation

    Potential Use of Plectranthus amboinicus in the Treatment of Rheumatoid Arthritis

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    Plectranthus amboinicus (P. amboinicus) is a folk herb that is used to treat inflammatory diseases or swelling symptoms in Taiwan. We investigated therapeutic efficacy of P. amboinicus in treating Rheumatoid Arthritis (RA) using collagen-induced arthritis animal model. Arthritis was induced in Lewis rats by immunization with bovine type II collagen. Serum anti-collagen IgG, IgM and C-reactive protein (CRP) were analyzed. To understand the inflammation condition of treated animals, production of TNF-α, IL-6 and IL-1β from peritoneal exudates cells (PEC) were also analyzed. P. amboinicus significantly inhibited the footpad swelling and arthritic symptoms in collagen-induced arthritic rats, while the serum anti-collagen IgM and CRP levels were consistently decreased. The production of pro-inflammatory cytokines TNF-α, IL-6 and IL-1β were also decreased in the high dosage of P. amboinicus group. Here, we demonstrate the potential anti-arthritic effect of P. amboinicus for treating RA, which might confer its anti-rheumatic activity. This differs the pharmacological action mode of indomethacin

    The RN/CFT Correspondence Revisited

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    We reconsidered the quantum gravity description of the near horizon extremal Reissner-Nordstr{\o}m black hole in the viewpoint of the AdS2_2/CFT1_1 correspondence. We found that, for pure electric case, the right moving central charge of dual 1D CFT is 6Q26 Q^2 which is different from the previous result 6Q36 Q^3 of left moving sector obtained by warped AdS3_3/CFT2_2 description. We discussed the discrepancy in these two approaches and examined novel properties of our result.Comment: revtex4, 16 pages, sign mistakes corrected, references include
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