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951.
Buoyancy of natural populations of marine phytoplankton 总被引:1,自引:0,他引:1
C. Lännergren 《Marine Biology》1979,54(1):1-10
Buoyancy of natural populations of marine phytoplankton was studied in a fjord in western Norway during the diatom bloom and in autumn. The study was carried out under approximate in situ conditions by means of an apparatus described in the paper. During the spring bloom, positive buoyancy was observed only once. Sinking rates of individual fractions ranged from 0 to more than 9 m day-1, and the mean sinking rates of the total chlorophyll content from 0 to at least 2. 2 m day-1. The highest rates occurred in the post-bloom period, while sinking appeared negligible from the onset of the bloom up to its culmination. In autumn, the population was dominated by small, flagellated cells. Positive buoyancy, or upward migration, was then observed in two out of three experiments. 相似文献
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Five species of Sepiola and Sepictta were reared in the laboratory from egg to adult size. Spawning was achieved in 3 species of Sepiola after 5 to 7 months. The growth rate of the species reared did not depend upon temperature, which ranged from 12.5° to 20°C. A fairly constant size increase (2.5 mm mantle length/month) was observed in Sepiola during the 5 months after hatching. In Sepietta, the same growth rate was observed until the fourth month after hatching, when it increased to the rate of 5 mm mantle length/month.Laboratoire associé au C.N.R.S. 相似文献
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Green liquor dregs is the biggest waste fraction at sulphate pulp mills. It is commonly landfilled. Here we demonstrate that
the utilization of green liquor dregs as a neutralizing agent for acidic wastewaters is a potential alternative and an environmentally
friendly method in contrast to its landfill disposal. The liming effect value of 39.6% for green liquor dregs, expressed as
Ca equivalent, is similar to the liming effect value of 38% of a commercial limestone product. In addition, the pH value of
10.7 indicates a strong liming effect. 相似文献
956.
Marco Tasin Anna-Carin Bäckman Marie Bengtsson Nélia Varela Claudio Ioriatti Peter Witzgall 《Chemoecology》2006,16(2):87-92
Summary. Host plant volatiles which attract insect herbivores for egg-laying are of principal interest with respect to insect ecology
and evolution. Direct applications concern population monitoring and control through behavioural manipulation. Identification
of behaviourally active plant secondary metabolites is essential also for plant breeding for insect resistance. Grapevine
moth females Lobesia botrana are attracted by upwind flight to green grape berries Vitis vinifera. The headspace of grape berries was collected on air filters. A solvent extract of these filters, released from a sprayer,
attracted females in the wind tunnel. The results demonstrate that volatile cues mediate attraction of grapevine moth females
to grape berries, and that headspace collections capture the essence of this odour signal. The air filter extracts were examined
by gas chromatography coupled with electroantennographic detection, and the compounds eliciting a consistent antennal response
in L. botrana females were identified by mass spectrometry. The headspace collection apparatus was calibrated for collection efficiency
of the active compounds. Their recovery rate ranged from 35 % for methyl salicylate to 83 % for (E,E)-α-farnesene. A synthetic ten-component blend was then formulated. The blend consisted of compounds eliciting an antennal
response, formulated in a blend ratio corrected for differences in collection efficiency. Subsequent wind tunnel tests showed
that female attraction to this synthetic ten-component blend was not significantly different from attraction to grape berries,
or to headspace collections of the same berries. At a release rate of 35 ng/h of the most abundant compound (E)-β-caryophyllene,
20 % of the test females approached the source of sprayed headspace collections and the ten-component synthetic blend, respectively.
In comparison, 100 g of green berries, releasing the main compound (E)-β-caryophyllene at a rate of ca. 4.7 ng/h, attracted
10 % of the females by upwind flight followed by source contact. 相似文献
957.
Barbara Raffaelli Eija Leppälä Clément Chappuis Kristiina Wähälä 《Environmental Chemistry Letters》2006,4(1):1-9
Seven new dibenzylbutyrolactone and six new dibenzylbutanediol lignans were prepared to assist in the identification of a
number of potential mammalian metabolites of the endocrine disrupting plant lignans syringaresinol and medioresinol, present
in food. 相似文献
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