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  • 1985-1989  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Vertical distribution and abundance of Acantharia and their symbionts (1988)
    Springer
    Marine biology 97 (1988), S. 559-569 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Microzooplankton was sampled during two cruises (Galápagos Vents, March 1985; Tongue of the Ocean and western edge of the Sargasso Sea, October/November 1985) by various collection methods (Niskin bottles, plankton nets, divers) to determine the vertical distribution and abundance of Acantharia. The larger size classes of Protozoa are dominated by the sarcodines, and Acantharia are frequently the most abundant of these in mesotrophic and oligotrophic oceans. The absolute densities of Acantharia have been consistently underestimated in many previous studies for two reasons: their skeletons dissolve in preserved samples, and they are undersampled by fine-meshed plankton nets. The previously identified dissolution problem may be less severe for concentrated samples because the dissolution of a portion of the Acantharia will raise the dissolved strontium concentration in the sample. Twenty five and 160 μm-mesh plankton nets consistently underestimate the abundance of net plankton by one to two orders of magnitude. Possible reasons for this significant error are discussed. In the Equatorial Pacific Ocean, Acantharia were found at densities as high as 30 liter-1 and integrated abundances of 1.58 to 5.34x105 Acantharia m-2. Up to 90% were concentrated near the surface; their abundance declined sharply below 20 m. At two stations in the Atlantic, peak densities reached 6.4 liter-1. Wind-mixing may spread individuals more evenly through the euphotic zone, but they reestablish their surface maximum during period of calm. Acantharia generally have relatively few, but large symbionts. Small individuals average about 6 symbionts per host, larger hosts average 40 symbionts, and some individuals may have thousands of algal cells. Acantharia symbionts made up less than 1% of the chlorophyll in the water column, even at their host's peak abundances of 30 liter-1. However, production estimates, using published sarcodine-symbiont production-rates, suggest that Acantharia could occasionally account for up to 20% or more of the carbon fixation in the upper euphotic zone of oligotrophic oceans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00391052
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Obligate mixotrophy inLaboea strobila, a ciliate which retains chloroplasts (1988)
    Springer
    Marine biology 99 (1988), S. 415-423 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The planktonic ciliateLaboea strobila Lohmann sequesters photosynthetically functional chloroplasts derived from ingested algae. The chloroplasts lie free in the cytoplasm and are most abundant just under the pellicle of the ciliate. The maximum rate of photosynthesis (Pmax) was 925 pg C ciliate-1h-1 (3.7 pg C pg chl.a -1h-1). At saturating irradiance, the amount of carbon fixed h-1 equaled 12.6% of the body carbon of the ciliate. To grow,L. strobila requires both light and algal food. In the absence of food, survival ofL. strobila is significantly longer in the light than in the dark. Based on ingestion rate and photosynthetic rate, we calculate that photosynthesis can make an important contribution to this ciliate's carbon budget even when algal food is plentiful.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02112135
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Electrooxidation of urea at the ruthenium titanium oxide electrode (1986)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 32 (1986), S. 1450-1458 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Urea adsorbs on the ruthenium titanium oxide electrode, depressing the observed current. For artificial kidney dialysate concentrations of urea and NaCl (0.50 kg/m3 and 100 mol/m3, respectively), the major electrolysis products are N2, CO2, O2, and H2, and the reaction mechanism is solution oxidation of urea by anodically generated active chlorine. A nitrogen-yielding direct electrode reaction is observed at high urea concentration (30 kg/m3) and low NaCl concentration (10-100 mol/m3).
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690320906
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Membrane separations in biotechnology (bioprocess technology series, volume 1). By W. Courtney Mcgregor, Ed., Marcel Dekker. Inc., 408 pp., 1986, $65.00 (1987)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 33 (1987), S. 1053-1053 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690330624
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    Paper (German National Licenses)
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