Results 1 - 10 of 89747
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[en] In this paper we calculate the next-to-leading-order (NLO) corrections to ρ-meson electromagnetic form factors by employing the factorization approach. We find that the NLO correction to is around 30% of the leading-order (LO) contribution in the region . The NLO correction to is close to 20% of the LO one in the region . The NLO radiative corrections to the electric, magnetic, and quadruple form factors are sizeable in magnitude and agree with those from other approaches.
[en] The proton's elastic electromagnetic form factors are calculated using an ansatz for the nucleon's Poincare covariant Faddeev amplitude that only retains scalar diquark correlations. A spectator approximation is employed for the current. On the domain of q2 accessible in modern precision experiments these form factors are a sensitive probe of nonperturbative strong interaction dynamics. The ratio of Pauli and Dirac form factors can provide realistic constraints on models of the nucleon and thereby assist in developing an understanding of nucleon structure. (author)
[en] Osteoclastogenesis is dependent on distinct stimuli that prime and activate osteoclast differentiation. One cytokine needed to prime monocytes for osteoclastogenesis is TGF-β, which enables and augments RANKL and TNF-α-induced osteoclast differentiation. However, the precise time-period during which this occurs and the molecular mechanism mediating this action are unknown. We report here TGF-β prime monocytes for osteoclast formation within 24 h by regulating expression of NFATc1, a key osteoclastic transcription factor. TGF-β directly induces cytoplasmic NFATc1 expression within 24 h, but is unable to stimulate NFATc1 nuclear translocation. Furthermore, RANKL-induced NFATc1 expression is dependent on the presence of TGF-β during the early stages of osteoclastogenesis. Similarly, TNF-α activates osteoclastogenesis by stimulating translocation of TGF-β-induced NFATc1. In light of these findings, it is apparent that osteoclast formation is dependent on coordinated interactions between TGF-β and RANKL/TNF-α that regulate the expression and intracellular distribution of NFATc1 during early stages of osteoclast differentiation
[en] The microscopic study of a cell is meant for the determination of the infinite multiplication factor of the cell, which is given by the four factor formula: K(infinite) = n(epsilon)pf. The analysis of an homogeneous reactor is similar to that of an heterogeneous reactor, but each factor of the four factor formula can not be calculated by the formulas developed in the case of an homogeneous reactor. A great number of methods was developed for the calculation of heterogeneous reactors and some of them are discussed. (Author)
[pt]O estudo microscopico da celula destina-se a determinacao do fator de multiplicacao infinita da celula, que e dado pela formula dos quatro fatores K(infinito) = n(epsilon)pf. A analise de um reator heterogeneo e semelhante a de um reator homogeneo, mas cada um dos quatro fatores nao pode ser computado pelas formulas desenvolvidas para o reator homogeneo. Um grande numero de metodos foi desenvolvido para o calculo de reatores heterogeneos e alguns deles sao discutidos neste trabalho. (Autor)
[en] Nucleon form factors are calculated on q2(set-membership sign)[0,3] GeV2 using an ansatz for the nucleon's Faddeev amplitude motivated by quark-diquark solutions of the relativistic Faddeev equation. Only the scalar diquark is retained, and it and the quark are confined. A good description of the data requires a nonpointlike diquark correlation with an electromagnetic radius of 0.8 rπ. The composite, nonpointlike nature of the diquark is crucial. It provides for diquark-breakup terms that are of greater importance than the diquark photon absorption contribution. (c) 1999 The American Physical Society
[en] Radiotherapy occupies a major place in cancer treatment, a place tending to expand under the impetus of several factors: constant progress of the techniques used, which provide new treatment options and now enable precision management of tumours with complex shapes; the development of conservative surgery with which it is combined; the ageing of the population, which should on its own lead to a 10% increase in treatments over the next few years. At the beginning of the third millennium French radiotherapy has experienced a major crisis with the occurrence in 2006 and 2007 of accidents which have had very serious consequences on the health of the patients involved. This crisis led the public authorities to introduce a 'national road map' to avoid the occurrence of further accidents in the future and to guarantee treatments of optimal quality to the patients. The mobilization of all concerned has been at the level of the challenge, and the implementation of measures to ensure treatment safety is now well under way in the radiotherapy establishments and centres. In his report preparing the way for the drafting of the Second Cancer Plan 2009-2013, Professor Grunfeld notes that 'a major paradigm change in the discipline' has been initiated as a consequence. Our system of care in radiotherapy nevertheless still has a worrying weakness; it concerns the fragility of the human resources of the radiotherapy teams, which it is essential to consolidate rapidly. (author)
[en] We reformulate the soft-collinear effective theory which includes the collinear quark and soft gluons. The quark form factor is used to prove that SCETII reproduces the IR physics of the full theory. We give a factorization proof in deep inelastic lepton-hadron scattering by use of the position space formulation
[en] Korean red ginseng is a traditional health food frequently used to prevent or treat various diseases worldwide. In this study, we evaluated the immunomodulatory activities of eleven compounds (1–11) isolated from Korean red ginseng, focusing on T cell function. First, the effects of the eleven compounds were studied on the regulation of IL-2, a potent T cell growth factor. Compounds 5, 7, and 9 significantly increased IL-2 secretion in phorbol 12-myristate 13-acetate (PMA)/ionomycin (Io)-induced EL-4 T cells. Next, we examined the effects of compounds 5, 7, and 9 on the regulation of transcription factors related to IL-2 production in T cells. Compound 9 significantly increased the PMA/Io-induced promoter activity of nuclear factor of activated T cells (NF-AT) in EL-4 T cells, but did not have any significant effects on the promoters of NF- κB. These results suggest that compound 9 activates T cell function via the regulation of NF-AT-mediated IL-2 production.
[en] A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering, at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer range 0-7 fm. This procedure is made possible with the advent of recent polarization measurements. The parameterizations allow a phenomenological characterization of the deuteron electromagnetic structure. They can be used to remove ambiguities in the form factors extraction from future polarization data
[en] Calculations of collinear correlation functions in perturbative QCD and Soft-Collinear Effective Theory (SCET) require a prescription for subtracting soft or zero-bin contributions in order to avoid double counting the contributions from soft modes. At leading order in λ, where λ is the SCET expansion parameter, the zero-bin subtractions have been argued to be equivalent to convolution with soft Wilson lines. We give a proof of the factorization of naive collinear Wilson lines that is crucial for the derivation of the equivalence. We then check the equivalence by computing the non-Abelian two-loop mixed collinear-soft contribution to the jet function in the quark form factor. These results provide strong support for the equivalence, which can be used to give a nonperturbative definition of the zero-bin subtraction at lowest order in λ