41 research outputs found

    Fragmentation functions using e+e- data from PETRA and LEP

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    We investigate fragmentation of charged particles in e+e- annihilation at 22, 35 and 44 GeV in terms of their polar angle and momentum distributions. From the angular distribution the ratio of longitudinal to total hadronic cross-section was determined at an average energy scale of 36.6 GeV to be σL/σtot=0.076±0.013\sigma_L / \sigma_{tot} = 0.076 \pm 0.013. At next-to-leading order this yields αS(36.6GeV)=0.150±0.025 \alpha_S (36.6 GeV) = 0.150 \pm 0.025 . The ξ=ln(1/x)\xi = \ln (1/x) distributions were used in conjunction with OPAL data from 91-208 GeV to study the scale dependence of the maximum position, ξ0\xi_0. We studied flavour dependence of ξ0\xi_0 as a possible explanation of this problem, using direct flavour dependent measurements of ξ0\xi_0 at 91 GeV by OPAL.Comment: 4 pages, 4 figures. Talk given by M. Blumenstengel at QCD 02, Montpellier, France, July 200

    Measurement of the longitudinal and transverse cross-section in e^+e^- annihilation at sqrt(s)=35-44 GeV

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    An investigation of the polar angle distribution of charged hadrons is presented using data taken by the JADE experiment at the PETRA e^+e^- collider at centre-of-mass energies of 35 and 44 GeV. From fits to the polar angle distribution the longitudinal, sigma_L, and transverse, sigma_T, cross-section relative to the total hadronic are determined at an average energy scale of 36.6 GeV. The results are sigma_L/sigma_tot = 0.067 +/- 0.013, sigma_T/sigma_tot = 0.933 -/+ 0.013 where total errors are given and the results are exactly anti-correlated. Using the next-to-leading order QCD prediction for the longitudinal cross-section, the value alpha_S(36.6 GeV) = 0.150 +/- 0.025 of the strong coupling constant is obtained in agreement with the world average value of alpha_S evolved to an energy scale of 36.6 GeV.Comment: 12 pages, LaTeX2e, 5 .eps-files included, pennames.sty included, submitted to Phys. Lett.

    Bendamustine: Safety and Efficacy in the Management of Indolent Non-Hodgkins Lymphoma

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    Bendamustine (Treanda, Ribomustin) was recently approved by the US Food and Drug Administration (FDA) for treatment of patients with rituximab refractory indolent lymphoma and is expected to turn into a frontline therapy option for indolent lymphoma. This compound with amphoteric properties was designed in the former Germany Democratic Republic in 1960s and re-discovered in 1990s with multiple successive well-designed studies. Bendamustine possesses a unique mechanism of action with potential antimetabolite properties, and only partial cross-resistance with other alkylators. Used in combination with rituximab in vitro, bendamustine shows synergistic effects against various leukemia and lymphoma cell lines. In clinical studies, bendamustine plus rituximab is highly effective in patients with relapsed-refractory indolent lymphoma, inducing remissions in 90% or more and a median progression-free survival of 23–24 months. The optimal dosing and schedule of bendamustine administration is largely undecided and varies among studies. Results of ongoing trials and dose-finding studies will help to further help ascertain the optimal place of bendamustine in the management of indolent NHL

    The fate of the homoctenids (Tentaculitoidea) during the Frasnian-Famennian mass extinction (Late Devonian)

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    The homoctenids (Tentaculitoidea) are small, conical-shelled marine animals which are amongst the most abundant and widespread of all Late Devonian fossils. They were a principal casualty of the Frasnian-Famennian (F-F, Late Devonian) mass extinction, and thus provide an insight into the extinction dynamics. Despite their abundance during the Late Devonian, they have been largely neglected by extinction studies. A number of Frasnian-Famennian boundary sections have been studied, in Poland, Germany, France, and the United States. These sections have yielded homoctenids, which allow precise recognition of the timing of the mass extinction. It is clear that the homoctenids almost disappear from the fossil record during the latest Frasnian “Upper Kellwasser Event”. The coincident extinction of this pelagic group, and the widespread development of intense marine anoxia within the water column, provides a causal link between anoxia and the F-F extinction. Most notable is the sudden demise of a group, which had been present in rock-forming densities, during this anoxic event. One new species, belonging to Homoctenus is described, but is not formally named here

    Event shapes in e+e- annihilation and deep inelastic scattering

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    This article reviews the status of event-shape studies in e+e- annihilation and DIS. It includes discussions of perturbative calculations, of various approaches to modelling hadronisation and of comparisons to data.Comment: Invited topical review for J.Phys.G; 40 pages; revised version corrects some nomenclatur

    Simulation of milling cells in shell through the cam module Compas‐3D v18

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    У роботі проведено комп’ютерне моделювання фрезерування карманів дослідної оболонки корпусу ракетно‐космічного призначення із алюмінієвого сплаву. При моделюванні застосована програма «Модуль ЧПУ. Фрезерная обработка», що є інтегрована в систему тривимірного моделювання КОМПАС‐3D v18. Показано, що з трьох стратегій фрезерування карманів («зігзаг», «еквідистанта», «по рядках») найбільш продуктивною є стратегія «зігзаг».The computer simulation of the milling of cells of the experimental shell of the rocket space housing of aluminum alloy. For simulation, we use the program "CNC Module. Milling Processing", which is integrated into Compas‐3D v18. It is shown that of the three pocket milling strategies ("zigzag", "equidistant", "line by line") the most productive is the "zigzag" strategy

    Alectorioid morphologies in Paleogene lichens : New evidence and re-evaluation of the fossil Alectoria succini Mägdefrau

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    One of the most important issues in molecular dating studies concerns the incorporation of reliable fossil taxa into the phylogenies reconstructed from DNA sequence variation in extant taxa. Lichens are symbiotic associations between fungi and algae and/or cyanobacteria. Several lichen fossils have been used as minimum age constraints in recent studies concerning the diversification of the Ascomycota. Recent evolutionary studies of Lecanoromycetes, an almost exclusively lichen-forming class in the Ascomycota, have utilized the Eocene amber inclusion Alectoria succinic as a minimum age constraint. However, a re-investigation of the type material revealed that this inclusion in fact represents poorly preserved plant remains, most probably of a root. Consequently, this fossil cannot be used as evidence of the presence of the genus Alectoria (Parmeliaceae, Lecanorales) or any other lichens in the Paleogene. However, newly discovered inclusions from Paleogene Baltic and Bitterfeld amber verify that alectorioid morphologies in lichens were in existence by the Paleogene. The new fossils represent either a lineage within the alectorioid group or belong to the genus Oropogon.Peer reviewe
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