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  • 1
    Electronic Resource
    Electronic Resource
    Depth related amino acid uptake by Prochlorococcus cyanobacteria in the Southern Atlantic tropical gyre (2004)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology ecology 50 (2004), S. 0 
    Details
    ISSN: 1574-6941
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Ambient concentrations and turnover rates of two amino acids, leucine and methionine, by total bacterioplankton and Prochlorococcus cyanobacteria were determined along a latitudinal transect across the Southern Atlantic gyre using a combined isotopic dilution and flow cytometric sorting technique. The ambient concentrations of methionine (0.2–0.65 nM) were about 2 times higher than the concentrations of leucine, while the turnover rates of the two amino acids were remarkably similar (0.1–0.7 nM d−1). The concentrations of both amino acids did not vary significantly with depth between 3 and 150 m but their turnover rates were 1.5–2 times higher in the top 3–80 m. Prochlorococcus took up amino acids in situ at high rates. Using a representative 35S-methionine precursor, about 25% of total bacterioplankton consumption of amino acids could be assigned to Prochlorococcus with low red fluorescence (Pro LRF) inhabiting the surface mixed layer down to 80 m and about 50% assigned to Prochlorococcus with high red fluorescence (Pro HRF) living below 100 m. In the same deep waters the cellular amino acid uptake of Pro LRF was less than 6% of that of the Pro HRF, indicating declining metabolic activity of the former. The mean cellular uptake rate of Pro HRF at depths below 120 m was 2.5 amol cell−1 d−1, 4 times higher than the rates of Pro LRF in the top 80 m. The difference could be partially explained by Pro HRF cellular biomass being twice that of Pro LRF. The biomass specific rates of Prochlorococcus were comparable or higher (particular of the Pro HRF) than that of other bacterioplankton. The reported findings could explain ecological success of mixotrophic Prochlorococcus cyanobacteria over both strictly autotrophic algae and heterotrophic bacteria in oligotrophic regions sustained by nutrient remineralisation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/j.femsec.2004.06.009
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  • 2
    Electronic Resource
    Electronic Resource
    Zur Kenntnis der Leukoplakia penis (1908)
    Springer
    Archives of dermatological research 91 (1908), S. 91-98 
    Details
    ISSN: 1432-069X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01843293
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  • 3
    Electronic Resource
    Electronic Resource
    Rotierende Fibrillen in derSynura-Geißel (1974)
    Springer
    Protoplasma 79 (1974), S. 215-223 
    Details
    ISSN: 1615-6102
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Bewegung der uniplanaren Geißel vonSynura sphagnicola wurde im positiven Phasenkontrast gefilmt und durch Einzelbildanalyse untersucht. 1. Treten kleinere Wellen auf, so besteht eine Beziehung zwischen Wellenlänge und Wellengeschwindigkeit: Alle auf der Geißel befindlichen Wellen brauchen, unabhängig von ihrer Wellenlänge, die gleiche Zeit, um eine Wellenlänge weiterzurücken. 2. Zeigt sich eine rhythmische Schwankung in der Geschwindigkeit des Wellenablaufes, so sind davon große wie kleine Wellen gleichermaßen betroffen. Die Periode dieser rhythmischen Bewegung entspricht der Ablaufzeit einer Wellenlänge. 3. Besonders im basalen Bereich der Geißel auftretende Verzögerungen der Wellen werden meist durch eine Beschleunigung im distalen Bereich ausgeglichen. 4. Sogenannte „Stehende Wellen“ kommen nur im basalen Teil vor. 5. In einigen Fällen war eine aus der Geißelspitze herausragende Fibrille zu erkennen, die genau im Rhythmus des Wellenablaufes rotierte. Die beschriebenen Phänomene lassen sich mit Hilfe von Fibrillen, die entlang der ganzen Geißel rotieren, leicht erklären, während nach der Sliding-force-Theorie und nach der Kontraktionstheorie komplizierte Systeme für die Koordination der aktiven Prozesse in oder zwischen den Fibrillen angenommen werden müssen.
    Notes: Summary The motion of the uniplanar flagellum ofSynura sphagnicola has been filmed in positive phase contrast. The propagation of waves has been investigated by single frame analysis. 1. If smaller waves appear, a relation exists between wave length and wave velocity: All waves of the flagellum need the same time for the propagation of one wave length, independently of the wave length. 2. If a rhythmical variation appears in the velocity of waves, short and long waves are similary concerned. The period of this rhythmical motion corresponds with the propagation-time of one wave length. 3. Retarded waves appear especially in the basal region of the flagellum which are usually compensated by accelerations in the distal region. 4. So-called “standing waves” appear only in the basal region. 5. A slender fibril projecting out of the flagellum tip has been recognized in some cases. It rotates exactly in the rhythm of the wave movement. The most simple interpretation for the described phenomena is the assumption that fibrils rotate along the whole length of the flagellum. The current theories of contraction and of sliding forces need intricate systems for the coordination of the active processes in or between the fibrils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02055790
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  • 4
    Electronic Resource
    Electronic Resource
    Zur Fibrillenrotation in derSynura-Geißel (1975)
    Springer
    Protoplasma 85 (1975), S. 285-290 
    Details
    ISSN: 1615-6102
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Bewegung der aus der Spitze der Geißel der ChrysophyceaeSynura sphagnicola herausragenden Fibrillen wurde gefilmt. Einzelbildanalyse des Bewegungsablaufs läßt keinen Zweifel darüber, daß diese Fibrillen eine eigenständige Rotation ausführen. Einige hydrodynamische Konsequenzen dieser Rotation werden in Zusammenhang mit den elektronenoptisch festgestellten „Speichen“ diskutiert.
    Notes: Summary The rotation of slender stiff fibrils projecting out in some cases of the uniplanar flagellum ofSynura sphagnicola has been filmed. Single frame analysis has shown that no doupt is possible on the true rotation of these fibrils in the flagellum. Some hydrodynamic consequences are discussed in relation to the “spokes” demonstrated with the electron microscope.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01567953
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  • 5
    Electronic Resource
    Electronic Resource
    Anisotropieeffekte konjugierter cyclischer Systeme, VI. Struktur und magnetische Anisotropie mesitylsubstituierter Ferrocene (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1968-1982 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Anisotropy Effects of Conjugated Cyclic Systems, VI. Structure and Magnetic Anisotropy of Mesityl-substituted FerrocenesTwo isomeric ferrocene derivatives have been obtained from 2-(2-ethyl-4,6-dimethylphenyl)-1,3-dimethylcyclopentadiene (22a). The exo,exo- (9) as well as the endo,endo-configuration (10) of these were determined by X-ray structure analysis. The assignment of the 1H NMR signals of the methyl groups in the spectrum of 1,1′,3,3′-tetramethyl-2,2′-dimesitylferrocene (7) is derived from the spectra of 9 and 10. Signals of methyl groups in exo-position of the mesitylferrocene are shifted by -0.74 ppm to higher magnetic field. Signals of methyl groups in endo-position directed towards the iron atom are shifted downfield by +0.71 ppm. Therefore, ferrocene develops a diamagnetic anisotropy which is similar to that of benzene.
    Notes: Aus 2-(2-Ethyl-4,6-dimethylphenyl)-1,3-dimethylcyclopentadien (22a) werden zwei isomere Ferrocenderivate erhalten. Durch Röntgenstrukturanalysen wird deren exo,exo-(9) bzw. endo,endo-Konfiguration (10) bestimmt. Anhand der 1H-NMR-Spektren dieser Ferrocene ist die Zuordnung der Methylgruppensignale im 1H-NMR-Spektrum des 1,1′,3,3′-Tetramethyl-2,2′-dimesitylferrocens (7) bewiesen. Signale von Methylgruppen in exo-Stellung des Mesitylferrocens werden um -0.74 ppm nach hohem Magnetfeld und solche von zum Eisenatom gerichteten in endo-Stellung um +0.71 ppm nach tiefem Feld verschoben. Daraus leitet sich für Ferrocen eine dem Benzol ähnliche diamagnetische Anisotropieverteilung ab.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180521
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  • 6
    Electronic Resource
    Electronic Resource
    Notiz über die Eliminierung des Halogens aus 1,4-Dibromtricyclo[6.4.0.04,9]dodecan (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 4613-4615 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Notice about the Elimination of Halogen from 1,4-Dibromotricyclo[6.4.0.04,9]dodecanecis-1,5-Dimethylenedecaline (3) is formed in a Grob-fragmentation by treatment of the title compounds 1 with sodium or lithium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851181131
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