2,013 research outputs found

    Wirkungen hoher Schwefelgaben auf Mineralstoffgehalte, Proteinfraktionen und KleberqualitÀt von Weizen aus biologisch-dynamischem Anbau

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    In der vorgestellten Arbeit sollte geprĂŒft werden, ob hohe Schwefel-Gaben den Dehnwiderstand des Klebers weiter verringern und welche Auswirkungen diese auf die Proteinfraktionen ausĂŒben. Gleichzeitig sollte ein Beitrag zur Schwefel-ErnĂ€hrung von Weizen unter biologisch-dynamischen AnbauverhĂ€ltnissen geleistet werden. Auf einem Winterweizenschlag (Sorte Bussard) eines biologisch-dynamisch wirt­schaftenden Betriebes (Dottenfelderhof, Bad Vilbel) wurde 1998 zu Vegetationsbe­ginn ein SchwefeldĂŒngungsversuch (0, 50, 100, 200, 400 kg S/ha als Kalimagnesia) angelegt. - ErtrĂ€ge, Stickstoff-, Schwefel-, Kalium- und Magnesium-Gehalte des Korns unter­schieden sich nicht. - Dagegen wurden die S-Gehalte des Strohs schon ab einer Gabe von 50 kg S/ha signifikant erhöht. - Ab Mengen von 200 kg S/ha ergaben sich signifikant niedrigere Gehalte HMW-Glutenin sowie DehnwiderstĂ€nde des Klebers. - Dagegen waren in der RP-HPLC-Analyse des Endospermmehls keine Unter­schiede erkennbar. Die Ergebnisse dieses Versuchs sind deshalb so bedeutsam, weil sie die AbhĂ€n­gigkeit der Proteinstruktur des Weizens im Zusammenhang mit der Schwefelversor­gung in folgender Weise bestĂ€tigen: WĂ€hrend bekannt ist, dass Schwefel-Mangel feste Kleber bzw. Teige induziert, werden die Kleber unter dem Einfluss hoher Schwefel-Gaben (im Überschuss) wei­cher. Aus solchen PhĂ€nomenen konnte dann ein weiterer Aspekt des Leitbildes fĂŒr die ZĂŒchtung von Weizensorten fĂŒr den biologisch-dynamischen Anbau entwickelt werden: - weichere Kleber - höhere Gehalte an Albuminen und Globulinen - gute Proteingehalte (bei akzeptablen ErtrĂ€gen) durch verbesserte NĂ€hrstoffauf­nahme (bessere Durchwurzelung

    Energy-angle dispersion of accelerated heavy ions at 67P/Churyumov–Gerasimenko: implication in the mass-loading mechanism

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    The Rosetta spacecraft studied the comet 67P/Churyumov–Gerasimenko for nearly two years. The Ion Composition Analyzer instrument on board Rosetta observed the positive ion distributions in the environment of the comet during the mission. A portion of the comet's neutral coma is expected to get ionized, depending on the comet's activity and position relative to the Sun, and the newly created ions are picked up and accelerated by the solar wind electric field, while the solar wind flow is deflected in the opposite direction. This interaction, known as the mass-loading mechanism, was previously studied by comparing the bulk flow direction of both the solar wind protons and the accelerated cometary ions with respect to the direction of the magnetic and the convective solar wind electric field. In this study, we show that energy–angle dispersion is occasionally observed. We report two types of dispersion: one where the observed motion is consistent with ions gyrating in the local magnetic field and another where the energy–angle dispersion is opposite to that expected from gyration in the local magnetic field. Given that the cometary ion gyro-radius in the undisturbed solar wind magnetic and electric field is expected to be too large to be detected in this way, our observations indicate that the local electric field might be significantly smaller than that of the undisturbed solar wind. We also discuss how the energy–angle dispersion, which is not consistent with gyration, may occur due to spatially inhomogeneous densities and electric fields

    Neurotoxische Enzephalopathie unter Neuroleptika und Lithium

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    Zusammenfassung: Überlappende neuroleptische Medikationen sind in psychiatrischen Behandlungen gelegentlich unumgĂ€nglich. Wir berichten ĂŒber eine unter schizoaffektiver Störung leidende 60-jĂ€hrige Frau, welche vorĂŒbergehend 3 Neuroleptika und Lithium erhielt. Hierunter entwickelte sie eine neurotoxische Enzephalopathie mit Symptomen eines malignen neuroleptischen Syndroms. GegenwĂ€rtig ist unklar, ob irreversible HirnschĂ€den zurĂŒckbleiben werden. Wir empfehlen engmaschige EEG-Kontrollen zur FrĂŒherkennung von NeurotoxizitĂ€

    Information transfer by vector spin chirality in finite magnetic chains

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    Vector spin chirality is one of the fundamental characteristics of complex magnets. For a one-dimensional spin-spiral state it can be interpreted as the handedness, or rotational sense of the spiral. Here, using spin-polarized scanning tunneling microscopy, we demonstrate the occurrence of an atomic-scale spin-spiral in finite individual bi-atomic Fe chains on the (5x1)-Ir(001) surface. We show that the broken inversion symmetry at the surface promotes one direction of the vector spin chirality, leading to a unique rotational sense of the spiral in all chains. Correspondingly, changes in the spin direction of one chain end can be probed tens of nanometers away, suggesting a new way of transmitting information about the state of magnetic objects on the nanoscale.Comment: accepted by Physical Review Letter

    Evolution of the ion environment of comet 67P during the Rosetta mission as seen by RPC-ICA

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    Rosetta has followed comet 67P from low activity at more than 3.6 au heliocentric distance to high activity at perihelion (1.24 au) and then out again. We provide a general overview of the evolution of the dynamic ion environment using data from the RPC-ICA ion spectrometer. We discuss where Rosetta was located within the evolving comet magnetosphere. For the initial observations, the solar wind permeated all of the coma. In 2015 mid-April, the solar wind started to disappear from the observation region, to re-appear again in 2015 December. Low-energy cometary ions were seen at first when Rosetta was about 100 km from the nucleus at 3.6 au, and soon after consistently throughout the mission except during the excursions to farther distances from the comet. The observed flux of low-energy ions was relatively constant due to Rosetta's orbit changing with comet activity. Accelerated cometary ions, moving mainly in the antisunward direction gradually became more common as comet activity increased. These accelerated cometary ions kept being observed also after the solar wind disappeared from the location of Rosetta, with somewhat higher fluxes further away from the nucleus. Around perihelion, when Rosetta was relatively deep within the comet magnetosphere, the fluxes of accelerated cometary ions decreased, as did their maximum energy. The disappearance of more energetic cometary ions at close distance during high activity is suggested to be due to a flow pattern where these ions flow around the obstacle of the denser coma or due to charge exchange losses
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