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131.
SYNOPSIS. Ochromonas danica in a complex natural growth medium dies at 6–10 C in 4 days; O. malhamensis in ∼2 days. O. danica grown in the medium supplemented with 4.0% glycerol survived at −10±2 C for 35 days, and with 8% glycerol 29 days. O. malhamensis lasted only to 5 days in these media supplemented with 4% glycerol. Ethylene glycol and dimethylsulfoxide were too toxic to be effective. Difficulties in freeze-preservation of certain other phagocytic cells, notably blood granulocytes having comparatively simple flexuous outer membranes, add interest to use of O. danica and O. malhamensis as test organisms for preservation methods, especially in the convenient, inexpensive -10 to -20 C range. Biphasic media with an overlay of distilled water serve for conservation at room temperature. Problems of mutational erosion of these photosynthetic phagotrophs are discussed. 相似文献
132.
P. Frankenberg 《Plant Ecology》1978,37(2):91-100
Summary It is attempted to determine in detail the boundaries between the extratropical flora (holarctis), the saharo-arabian flora and the tropical flora (palaeotropis) in arid northern Africa on the basis of life forms.The analysis is based on 1258 species selected by a frequency distribution (Fig. 2). The species are classified into 12 groups of different life forms and floristic elements; phanerophytes (Ph), chamaephytes (Ch), hemicryptophytes (H) and therophytes (Th), as well as a tropical fkoristic element (P), a saharo-arabian (S) and an extratropical one (H). Thus, floristic boundaries of the tropics and the extratropical regions could be differentiated for the four life forms concerned (Fig. 4). The eight boundaries separate zones dominated by different floristic elements of any life form. Fig. 4 shows that, e.g., the floristic boundary of tropical phanerophytes runs much further north than equivalent boundaries of other life forms. A more detailed interpretation of fig. 4 is given for the east and west coast and for the Nile valley. The differences between the east and the west coast are explained by different temperature conditions (cold ocean current). For the Nile valley it could be shown that the taller the life forms of tropical species, the further north their numbers are still dominant over the equivalent extratropical life forms.Zonal life form spectra (Fig. 5) are presented for each floristic element. Therophytes and chamaephytes are the dominant life forms in the Sahara. Therophytes dominate on shallow gravelly soils over solid rock, whereas chamaephytes dominate where their roots can penetrate into deeper layers.Some relations between life forms or floristic elements and elimate are shown using correlation analysis. In this connection the physiology of summer and winter therophytes is briefly discussed.
Nomenklatur nach Quézel (1965) 相似文献
133.
L Frankenberg 《Laboratory animals》1979,13(4):311-312
The puncture is performed during ether anaesthesia and will usually give 0.6-0.8 ml within 10-15 s. Blood volumes up to 1 ml have frequently been obtained from adult mice with this method. 相似文献