76 research outputs found

    De bosvegetatie van de Achterhoek en enkele aangrenzende gebieden

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    The tree, shrub, herb and moss vegetation of woodland in the Achterhoek and neighbouring areas was analysed. It was described according to the concepts of the French and Swiss school of Braun-Blanquet. The study was confined to woodland whose composition approached the natural state. Experimental areas were of different form from 150 to 300, sometimes 800 m 2. The sociological survey was supplemented by data on habitat, growth and age of the stand and the vegetation layers. The descriptions of the different plots were combined into tables, indicating the characteristic species of the association, the higher sociological units, the companion species and the accidental species, while subassociations were separated according to differentiating species. The descriptions and tables refer to plant communities belonging to Alnion glutinosae, Alneto-Fraxinion, Quercion and various degeneration stages.These chapters are preceded by a discussion of different climax theories. The work closes with an attempt to reconstruct the original vegetation

    Measurement of the branching ratio of pi^0 -> e^+e^- using K_L -> 3 pi^0 decays in flight

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    The branching ratio of the rare decay pi^0 -> e^+e^- has been measured in E799-II, a rare kaon decay experiment using the KTeV detector at Fermilab. The pi^0's were produced in fully-reconstructed K_L -> 3 pi^0 decays in flight. We observed 275 candidate pi^0 -> e^+e^- events, with an expected background of 21.4 +- 6.2 events which includes the contribution from Dalitz decays. We measured BR(pi^0 -> e^+e^-, x>0.95) = (6.09 +- 0.40 +- 0.24) times 10^{-8}, where the first error is statistical and the second systematic. This result is the first significant observation of the excess rate for this decay above the unitarity lower bound.Comment: New version shortened to PRL length limit. 5 pages, 4 figures. Published in Phys. Rev. Let

    Measurement of the rate of nu_e + d --> p + p + e^- interactions produced by 8B solar neutrinos at the Sudbury Neutrino Observatory

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    Solar neutrinos from the decay of 8^8B have been detected at the Sudbury Neutrino Observatory (SNO) via the charged current (CC) reaction on deuterium and by the elastic scattering (ES) of electrons. The CC reaction is sensitive exclusively to nu_e's, while the ES reaction also has a small sensitivity to nu_mu's and nu_tau's. The flux of nu_e's from ^8B decay measured by the CC reaction rate is \phi^CC(nu_e) = 1.75 +/- 0.07 (stat)+0.12/-0.11 (sys.) +/- 0.05(theor) x 10^6 /cm^2 s. Assuming no flavor transformation, the flux inferred from the ES reaction rate is \phi^ES(nu_x) = 2.39+/-0.34 (stat.)+0.16}/-0.14 (sys) x 10^6 /cm^2 s. Comparison of \phi^CC(nu_e) to the Super-Kamiokande Collaboration's precision value of \phi^ES(\nu_x) yields a 3.3 sigma difference, providing evidence that there is a non-electron flavor active neutrino component in the solar flux. The total flux of active ^8B neutrinos is thus determined to be 5.44 +/-0.99 x 10^6/cm^2 s, in close agreement with the predictions of solar models.Comment: 6 pages (LaTex), 3 figures, submitted to Phys. Rev. Letter

    The data acquisition system of the CHORUS experiment

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    In the years 1994-1998 the CHORUS Collaboration has recorded data in the CERN WA95 experiment. Here we describe the data acquisition system that has been used, featuring concurrent hierarchical state machines, a remote operating system, a buffer manager, a dispatcher, a control panel and a supervisor

    First Neutrino Observations from the Sudbury Neutrino Observatory

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    The first neutrino observations from the Sudbury Neutrino Observatory are presented from preliminary analyses. Based on energy, direction and location, the data in the region of interest appear to be dominated by 8B solar neutrinos, detected by the charged current reaction on deuterium and elastic scattering from electrons, with very little background. Measurements of radioactive backgrounds indicate that the measurement of all active neutrino types via the neutral current reaction on deuterium will be possible with small systematic uncertainties. Quantitative results for the fluxes observed with these reactions will be provided when further calibrations have been completed.Comment: Latex, 7 pages, 10 figures, Invited paper at Neutrino 2000 Conference, Sudbury, Canada, June 16-21, 2000 to be published in the Proceeding

    The data acquisition system of the CHORUS experiment

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    In the years 1994--1998 the CHORUS Collaboration has recorded data in the CERN WA95 experiment. Here we describe the data acquisition system that has been used, featuring concurrent hierarchical state machines, a remote operating system, a buffer manager, a dispatcher, a control panel and a supervisor

    The CHORUS neutrino oscillation search experiment

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    The CHORUS experiment has successfully finished run I (320~000 recorded \numu\ CC in 94/95) and performed half of run II (225~000 \numu\ CC in 96). The analysis chain was exercised on a small data sample for the muonic \tdecay\ search using for the first time fully automatic emulsion scanning. This pilot analysis, resulting in a limit \sintth \leq 3 \cdot 10^{-2}, confirms that the CHORUS proposal sensitivity (\sintth \leq 3 \cdot 10^{-4}) is within reach in two years

    Proton-Antiproton Annihilation and Meson Spectroscopy with the Crystal Barrel

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    This report reviews the achievements of the Crystal Barrel experiment at the Low Energy Antiproton Ring (LEAR) at CERN. During seven years of operation Crystal Barrel has collected very large statistical samples in pbarp annihilation, especially at rest and with emphasis on final states with high neutral multiplicity. The measured rates for annihilation into various two-body channels and for electromagnetic processes have been used to test simple models for the annihilation mechanism based on the quark internal structure of hadrons. From three-body annihilations three scalar mesons, a0(1450), f0(1370) and f0(1500) have been established in various decay modes. One of them, f0(1500), may be identified with the expected ground state scalar glueball.Comment: 64 pages, LATEX file, 36 figures are available as ps files at http://afuz01.cern.ch/claude/ Submitted to Reviews of Modern Physic

    Measurement of the νe\nu_e and Total 8^{8}B Solar Neutrino Fluxes with the Sudbury Neutrino Observatory Phase I Data Set

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    This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kt-year exposure of heavy water to the solar 8^8B neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic uncertainties, and estimates of backgrounds. Also discussed are SNO's approach to statistical extraction of the signals from the three neutrino reactions (charged current, neutral current, and elastic scattering) and the results of a search for a day-night asymmetry in the νe\nu_e flux. Under the assumption that the 8^8B spectrum is undistorted, the measurements from this phase yield a solar νe\nu_e flux of ϕ(νe)=1.760.05+0.05(stat.)0.09+0.09(syst.)×106\phi(\nu_e) = 1.76^{+0.05}_{-0.05}{(stat.)}^{+0.09}_{-0.09} {(syst.)} \times 10^{6} cm2^{-2} s1^{-1}, and a non-νe\nu_e component ϕ(νμτ)=3.410.45+0.45(stat.)0.45+0.48(syst.)×106\phi(\nu_{\mu\tau}) = 3.41^{+0.45}_{-0.45}{(stat.)}^{+0.48}_{-0.45} {(syst.)} \times 10^{6} cm2^{-2} s1^{-1}. The sum of these components provides a total flux in excellent agreement with the predictions of Standard Solar Models. The day-night asymmetry in the νe\nu_e flux is found to be Ae=7.0±4.9(stat.)1.2+1.3A_{e} = 7.0 \pm 4.9 \mathrm{(stat.)^{+1.3}_{-1.2}}% \mathrm{(sys.)}, when the asymmetry in the total flux is constrained to be zero.Comment: Complete (archival) version of SNO Phase I results. 78 pages, 46 figures, 34 table

    The status of platinum anticancer drugs in the clinic and in clinical trials

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    Since its approval in 1979 cisplatin has become an important component in chemotherapy regimes for the treatment of ovarian, testicular, lung and bladder cancers, as well as lymphomas, myelomas and melanoma. Unfortunately its continued use is greatly limited by severe dose limiting side effects and intrinsic or acquired drug resistance. Over the last 30 years, 23 other platinum-based drugs have entered clinical trials with only two (carboplatin and oxaliplatin) of these gaining international marketing approval, and another three (nedaplatin, lobaplatin and heptaplatin) gaining approval in individual nations. During this time there have been more failures than successes with the development of 14 drugs being halted during clinical trials. Currently there are four drugs in the various phases of clinical trial (satraplatin, picoplatin, LipoplatinTM and ProLindacTM). No new small molecule platinum drug has entered clinical trials since 1999 which is representative of a shift in focus away from drug design and towards drug delivery in the last decade. In this perspective article we update the status of platinum anticancer drugs currently approved for use, those undergoing clinical trials and those discontinued during clinical trials, and discuss the results in the context of where we believe the field will develop over the next decade
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