Damping of the HERA effect in DIS?

The drastic rise of the proton structure function F_2(x,Q^2) when the Bj\"orken variable x decreases, seen at HERA for a large span of Q^2, negative values for the 4-momentum transfer, may be damped when Q^2 increases beyond several hundreds GeV^2. A new data analysis and a comparison with recent models for the proton structure function is proposed to discuss this phenomenon in terms of the derivative \partial ln F_2(x,Q^2)/\partial ln(1/x).Comment: 14 pages (LaTeX) including 7 figures, misprints are correcte

Fuchs versus Painlev\'e

We briefly recall the Fuchs-Painlev\'e elliptic representation of Painlev\'e VI. We then show that the polynomiality of the expressions of the correlation functions (and form factors) in terms of the complete elliptic integral of the first and second kind, $K$ and $E$, is a straight consequence of the fact that the differential operators corresponding to the entries of Toeplitz-like determinants, are equivalent to the second order operator $L_E$ which has $E$ as solution (or, for off-diagonal correlations to the direct sum of $L_E$ and $d/dt$). We show that this can be generalized, mutatis mutandis, to the anisotropic Ising model. The singled-out second order linear differential operator $L_E$ being replaced by an isomonodromic system of two third-order linear partial differential operators associated with $\Pi_1$, the Jacobi's form of the complete elliptic integral of the third kind (or equivalently two second order linear partial differential operators associated with Appell functions, where one of these operators can be seen as a deformation of $L_E$). We finally explore the generalizations, to the anisotropic Ising models, of the links we made, in two previous papers, between Painlev\'e non-linear ODE's, Fuchsian linear ODE's and elliptic curves. In particular the elliptic representation of Painlev\'e VI has to be generalized to an ``Appellian'' representation of Garnier systems.Comment: Dedicated to the : Special issue on Symmetries and Integrability of Difference Equations, SIDE VII meeting held in Melbourne during July 200

Early

Arthritis Rheum. 2004 Dec;50(12):3934-40. Early response to immunosuppressive therapy predicts good renal outcome in lupus nephritis: lessons from long-term followup of patients in the Euro-Lupus Nephritis Trial. Houssiau FA, Vasconcelos C, D'Cruz D, Sebastiani GD, de Ramon Garrido E, Danieli MG, Abramovicz D, Blockmans D, Mathieu A, Direskeneli H, Galeazzi M, Gül A, Levy Y, Petera P, Popovic R, Petrovic R, Sinico RA, Cattaneo R, Font J, Depresseux G, Cosyns JP, Cervera R. Université Catholique de Louvain, Brussels, Belgium. [email protected] Abstract OBJECTIVE: In the Euro-Lupus Nephritis Trial (ELNT), 90 patients with lupus nephritis were randomly assigned to a high-dose intravenous cyclophosphamide (IV CYC) regimen (6 monthly pulses and 2 quarterly pulses with escalating doses) or a low-dose IV CYC regimen (6 pulses of 500 mg given at intervals of 2 weeks), each of which was followed by azathioprine (AZA). After a median followup of 41 months, a difference in efficacy between the 2 regimens was not observed. The present analysis was undertaken to extend the followup and to identify prognostic factors. METHODS: Renal function was prospectively assessed quarterly in all 90 patients except 5 who were lost to followup. Survival curves were derived using the Kaplan-Meier method. RESULTS: After a median followup of 73 months, there was no significant difference in the cumulative probability of end-stage renal disease or doubling of the serum creatinine level in patients who received the low-dose IV CYC regimen versus those who received the high-dose regimen. At long-term followup, 18 patients (8 receiving low-dose and 10 receiving high-dose treatment) had developed permanent renal impairment and were classified as having poor long-term renal outcome. We demonstrated by multivariate analysis that early response to therapy at 6 months (defined as a decrease in serum creatinine level and proteinuria <1 g/24 hours) was the best predictor of good long-term renal outcome. CONCLUSION: Long-term followup of patients from the ELNT confirms that, in lupus nephritis, a remission-inducing regimen of low-dose IV CYC followed by AZA achieves clinical results comparable with those obtained with a high-dose regimen. Early response to therapy is predictive of good long-term renal outcome. PMID: 15593207 [PubMed - indexed for MEDLINE

Large PT Double Photon Production in Hadronic Collisions - Beyond Leading Logarithm QCD Calculation

Aurenche P, Douiri A, Baier R, Fontannaz M, Schiff D. Large PT Double Photon Production in Hadronic Collisions - Beyond Leading Logarithm QCD Calculation. Zeitschrift für Physik C: Particles and fields. 1985;29(3):459-475

Gravitational Lensing by Black Holes

We review the theoretical aspects of gravitational lensing by black holes, and discuss the perspectives for realistic observations. We will first treat lensing by spherically symmetric black holes, in which the formation of infinite sequences of higher order images emerges in the clearest way. We will then consider the effects of the spin of the black hole, with the formation of giant higher order caustics and multiple images. Finally, we will consider the perspectives for observations of black hole lensing, from the detection of secondary images of stellar sources and spots on the accretion disk to the interpretation of iron K-lines and direct imaging of the shadow of the black hole.Comment: Invited article for the GRG special issue on lensing (P. Jetzer, Y. Mellier and V. Perlick Eds.). 31 pages, 12 figure

The ALLM parameterization of #sigma#_t_o_t(#gamma#&quot;*p). An update

The ALLM parameterization of #sigma#_t_o_t(#gamma#&quot;*p) has been updated by using all published F_2 data to determine its parameters. The fit yields a #chi#&quot;2/ndf of 0.97 for the 1356 data points. The updated ALLM parameterization, ALLM97, gives a good description of all the available data in the whole x and Q&quot;2 ranges studied so far (3 x 10&quot;-&quot;6&lt;x&lt;0.85, 0#&lt;=#Q&quot;2&lt;5000 GeV&quot;2). (orig.)Available from TIB Hannover: RA 2999(97-251) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman