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Der gemeinsame europäische Referenzrahmen für Sprachen (GER) ist ein wichtiges Dokument, das seit seinem Erscheinen die Fremdsprachendidaktik sowie das Fremdsprachenlernen stark beeinflusst. Die Diskussionen über die Wirkung reichen seit seiner Entstehung bis heute von radikaler Ablehnung bis zu einer vorsichtig positiven Einschätzung seiner Wirkung. Nach fast zwei Jahrzehnten seiner Existenz wird er aus der Perspektive der Fremdsprachendidaktik diskutiert. Die theoretischen Überlegungen werden mithilfe von Auszügen aus einigen Leitfadeninterviews von Lehrkräften, die Erfahrungen mit dem DaF-Unterricht vor dem GER und mit dem GER haben, aus einer neuen Perspektive betrachtet. Abschließend werden jene Aspekte des GER hervorgehoben, die einer Modifikation dieses ansonsten wichtigen Dokuments für das Fremdsprachenlernen bedürfen und die zum Teil im Begleitheft (CEFR/CV) bereits revidiert wurden.
A skeletal world revision of the genus is presented to accompany a family account for Flora Malesiana. 82 species are recognised, of which 74 occur in the Malesiana region. Six species are desctibed as new, one species is raised from infraspecific status, and five species are restored from synonymy. Many names are typified for the first time. Three widespread, or locally abundant hybrids are also included. Full descriptions are given for new (6) or recircumscribed (7) species, and emended descriptions of species arc given where necessary (9). Critical notes are given for all the species. Little known and excluded species are discussed. An index to all published species names and an index of exsiccatae is given.
[ω- (3-Acetylpyridinio) -n-alkyl] adenosine pyrophosphates are coenzyme analogs of NAD⊕. The adenosine pyrophosphate moiety and the 3-acetylpyridine ring of the analogs are connected by n-alkyl chains of different lengths (ethyl -hexyl). The analogs form strong dissociating complexes with lactate dehydrogenase. The complex formation is predominantly achieved by interaction of the ADP moiety with its respective binding domain at the active site.
The redox potentials of the analogs and NAD are of similar magnitude. The coenzyme function of the analogs depends upon the length of the hydrocarbon chain. Lactate dehydrogenase and alcohol dehydrogenases from yeast and horse liver do not catalize hydrogen transfer from their substrates to any other alkyl analog but [4- (3-acetylpyridinio)-n-butyl] adenosine pyrophosphate, aldehyde dehydrogenase from horse liver catalizes hydrogen transfer from acetaldehyde to the pentyl derivative and glyceraldehyde-3-phosphate dehydrogenase catalizes hydrogen transfer to both analogs. In no case, hydrogen transfer from or to one of the 3-acetylpyridine-n-alkyl analogs proceeded with a velocity comparable to NAD or its 3-acetylpyridine analog. The results show that the nicotinamide bound ribose in NAD is involved in the binding and the activation of the coenzyme.
New reactive coenzyme analogues for affinity labeling of NAD+ and NADP+ dependent dehydrogenases
(1995)
Reactive coenzyme analogues ω-(3-diazoniumpyridinium)alkyl adenosine diphosphate were prepared by reaction of ω-(3-aminopyridinium)alkyl adenosine diphosphate with nitrous acid. In these compounds the nicotinamide ribose is substituted by hydrocarbon chains of varied lengths (n-ethyl to n-pentyl). The diazonium compounds are very unstable and decompose rapidly at room temperature. They show a better stability at 0 °C. L actate and alcohol dehydrogenase do not react with any of the analogues. Glyceraldehyde-3-phosphate dehydrogenase reacts rapidly with the diazonium pentyl compound. Decreasing the length of the alkyl chain significantly decreases the inactivation velocity. 3α,20β-Hydroxysteroid dehydrogenase reacts at 0 °C with the ethyl homologue and slowly with the propyl compound. The butyl-and pentyl analogues do not inactivate at 0 °C. Tests with 14C -labeled 2-(3-diazoniumpyridinium)ethyl adenosine diphosphate show that complete loss of enzyme activity results after incorporation of 2 moles of inactivator into 1 mole of tetrameric enzyme. 4-(3-Acetylpyridinium)butyl 2 ′-phospho-adenosine diphosphate, a structural analogue of NADP +, was prepared by condensation of adenosine-2,3-cyclophospho-5′-phosphomorpholidate with (3-acetylpyridinium)butyl phosphate, followed by hydrolysis of the cyclic phosphoric acid ester with 2 ′:3′-cyclonucleotide-3′-phosphodiesterase. Because of the redox potential (-315 mV) and the distance between the pyridinium and phosphate groups, this analogue is a hydrogen acceptor and its reduced form a hydrogen donor in tests with alcohol dehyd rogenase from Thermoanaerobium brockii. The reduced form of the coenzyme analogue also is a hydrogen donor with glutathione reductase. With other NADP +-dependent dehydrogenases the com pound has been show n to be a competitive inhibitor against the natural coenzyme. The acetyl group reacts with bromine to form the bromoacetyl group. This reactive bromoacetyl analogue is a specific active-site directed irreversible inhibitor of isocitrate dehydrogenase.
A new NAD⊕-isomer was prepared, in which the ᴅ-ribose of the adenosine moiety was sub stituted by the enantiomeric ʟ-ribose. As compared to nicotinamide-adenine-dinucleotide (NAD⊕) and NADH the coenzyme isomer (ᴅ,ʟ)-NAD⊕ and its dihydroform (ᴅ,ʟ)-NADH are far less tightly bound to lactate dehydrogenase and alcohol dehydrogenase from horse liver. In the presence of the second substrate (ᴅ,ʟ)-NAD⊕ and (ᴅ,ʟ)-NADH act as hydrogen acceptor and hydrogen donator, respectively, with lactate dehydrogenase and alcohol dehydrogenases from horse liver and yeast. Compared to NAD⊕ and NADH the Michaelis constants are always increased, the catalytic constants (V/Et) were found to be decreased except for the dihydroform reacting with alcohol dehydrogenase from liver.
Grundwasser-Ganglinien unter verschiedenen Pflanzengesellschaften in nordwestdeutschen Heidemooren
(1986)
In einem naturnahen nordwestdeutschen Heidemoor wurden die Grundwasser-Ganglinien im Jahresverlauf unter verschiedenen Pflanzengesellschaften gemessen. Untersucht wurden in Transekten vom Moorkern bis zu den Rändern das Erico-Sphagnetum magellanici, das Rhynchosporetum albae, das Myricetum gale sowie sekundäre Erica tetralix-Heiden auf entwässerten Torfen. Vor allem innerhalb der floristisch unterschiedlichen Varianten und Ausbildungen des Erico-Sphagnetum magellanici ergeben sich besonders feine Abstufungen der Grundwasser-Ganglinien.
Flora und Vegetation eines kleinen Moores in der Lüneburger Heide, das wegen seiner seltenen Pflanzen und Pflanzengesellschaften 1975 unter Naturschutz gestellt wurde, werden beschrieben. Es lassen sich vier Assoziationen und sechs Gesellschaften unklarer Zugehörigkeit unterscheiden. Die wichtigste Gesellschaft ist das Erico-Sphagnetum magellanici mit einem bemerkenswert hohen Anteil von Narthecium ossifragum. Die Verteilung der Pflanzengesellschaften ist in zwei Vegetationskarten dargestellt. Außerdem werden Probleme des Naturschutzes erörtert und Vorschläge zur Erhaltung der heutigen Pflanzendecke gemacht.
In der Süd-Slowakei (Ipel-Tal) wurden fünf selten gefundene Spinnenarten nachgewiesen, zu deren Verbreitung in der Slowakei wenig bekannt ist: Runcinia lateralis (C.L.KOCH, 1838), Allomengea vidua (O.P.CAMBRIDGE, 1889), Theridion simile C.L.KOCH, 1836, Gibbaranea ullrichi(HAHN, 1835) und Dolomedes fimbriatus (CLERCK, 1757).
The nervous system is a non-linear dynamical complex system with many feedback loops. A conventional wisdom is that in the brain the quantum fluctuations are self-averaging and thus functionally negligible. However, this intuition might be misleading in the case of non-linear complex systems. Because of an extreme sensitivity to initial conditions, in complex systems the microscopic fluctuations may be amplified and thereby affect the system’s behavior. In this way quantum dynamics might influence neuronal computations. Accumulating evidence in non-neuronal systems indicates that biological evolution is able to exploit quantum stochasticity. The recent rise of quantum biology as an emerging field at the border between quantum physics and the life sciences suggests that quantum events could play a non-trivial role also in neuronal cells. Direct experimental evidence for this is still missing but future research should address the possibility that quantum events contribute to an extremely high complexity, variability and computational power of neuronal dynamics.