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41.
Klassifikation der Prachtfinken, Spermestidae, auf Grund der Rachenzeichnungen ihrer Nestlinge 总被引:1,自引:0,他引:1
Hans Steiner 《Journal of Ornithology》1960,101(1-2):92-112
Ohne ZusammenfassungMotto: Mitunter gerät der Taxonom in ein Dilemma, worin ihm keine Nomenklatur-Regel zu Hilfe kommt.E. Stresemann, Vierteljahrsschr. Naturf. Ges. Zürich, Jahrg. 104, 1959, S. 213. 相似文献
42.
Michael Lippert Karl Steiner Hans-Dieter Payer Sabina Simons Christian Langebartels Heinrich Sandermann Jr. 《Trees - Structure and Function》1996,10(4):268-275
An exposure — response study with proportionalto-ambient ozone levels was conducted in closed chambers on 3-year-old European beech (Fagus sylvatica L.) of montane origin. The fumigation started in April 1990 and lasted for a single growing season. Climate data and ozone concentrations monitored at an experimental station of the Institute for Applied Plant Biology, Schönenbuch, Switzerland were simulated in the exposure chambers 12 days later (1*O3). To test exposure-response relations three additional treatments were applied, subambient (0.2*O3) and two proportionally increased ozone treatments (1.5*O3 and 2*O3). The photosynthetic behaviour of the trees in August revealed the light reactions to be less affected than parameters which are related to the dark reactions of photosynthesis. Assimilation (A350), apparent carboxylation efficiency (CE), and maximum photosynthetic capacity (A2500) were reduced with increasing ozone concentration. For the ozone response of CE and A2500 Critical Levels were calculated. 相似文献
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Semicontinuously grown wild carrot ( Daucus carota L.) cells were used in an investigation of the effect of culture medium pH on ammonium uptake in suspension cultures as a first step in exploring the relationship between pH and anthocyanin biosynthesis. In contrast to published data showing decreasing uptake rates with decreasing culture medium pH, ammonium-limited, semicontinuous carrot cell cultures showed a 25% greater ammonium uptake rate at pH 4.5 than at pH 5.5. When cells that had been grown semicontinuously in medium with a pH of 4.5 or 5.5 were grown in batch cultures at pH 4.5, 5.5 or 6.5 the ammonium uptake rates were those of the semicontinuous cultures, indicating that the pH of the batch culture medium had no effect on ammonium uptake rates over 7 days. The cell culture was composed of very small aggregates when it was grown semicontinuously in medium at pH 4.5, but was composed of large aggregates when it was grown semicontinuously in medium at pH 5.5. The aggregation/disaggregation of the cells was pH dependent, as changing the pH of the semicontinuous culture medium altered the extent of the aggregation. We conclude that the change in culture medium pH caused the cells to aggregate or disaggregate which in turn decreased or increased the rate of ammonium uptake from the medium. 相似文献
46.
Platelet activation was elevated by changes in the fluorescence anisotropy of the sulfhydryl-reactive fluorescent probe, (5-[2-(iodoacetyl) aminacetyl]aminonaphthalene-1-sulfonic acid. The membrane-permeable fluorophore was shown to bind to a multitude of cytoplasmic and membrane proteins. Platelets were stimulated by addition of thrombin, arachidonic acid or ADP under conditions that did not induce aggregation. A sudden increase in the fluorescence anisotropy, r of moderate degree (25-33%) occurred during the first 60 s after exposure of platelets to the aggregating agents and was sustained during the entire period of observation (15-18 min). Phenylmethylsulfonyl thrombin was unable to produce these changes in fluorescence anisotropy. Preincubation of platelets with colchicine reduced r within 30-60 s after platelets were exposed to thrombin. These findings are interpreted as an indication of a general decrease in the 'motional freedom' of the fluorophores and indirectly their ligand molecules. 相似文献
47.
Robert F. Steiner Mahnaz Motevalli-Alibadi 《Archives of biochemistry and biophysics》1984,234(2):522-530
The average separation of the phenolic groups of tyrosine-99 and tyrosine-138 has been measured by radiationless energy transfer between each tyrosine and the nitro derivative of the second tyrosine. A separation of 16.7 ± 0.7 Å was found in the absence of Ca2+ and 15.5 ± 0.7 Å in the presence of Ca2+. 相似文献
48.
R F Steiner 《Archives of biochemistry and biophysics》1984,228(1):105-112
The quenching by radiationless energy transfer of the ultraviolet fluorescence of Tyr-99 and Tyr-138 by bound 1-anilinonaphthalene-8-sulfonate (1,8-ANS) has been employed to determine the separation of a hydrophobic binding site of 1,8-ANS from each of the tyrosines. The results suggest that the dominant binding site is located in the N-terminal region of domain III. 相似文献
49.
In this study we examined the effects of inhibitors of the lipoxygenase and cyclooxygenase pathways on mouse myoblast fusion. The fusion of cloned mouse myoblasts was markedly inhibited, in a dose-dependent manner, when cells were cultured in medium supplemented with either phenidone (1-phenyl-3-pyrazolidione) or BW755c (3-amino-1-(3-tri-fluoromethylphenyl)-2-pyrazoline), drugs which have been reported to inhibit lipoxygenase and cyclo-oxygenase activities. Fusion was also inhibited when these cells were cultured in medium supplemented with esculetin (6,7-dihydroxycoumarin) which has been reported to inhibit lipoxygenase activity. Removal of the above inhibitors resulted in a return to control levels of fusion. Fusion was not demonstrably inhibited with aspirin (acetylsalicylic acid) and only inhibited to a minor extent with indomethacin (1-(p-chlorobenzoyl)-5-methoxy-2-methylindole-3-acetic acid); both of these drugs are inhibitors of cyclo-exygenase activity. 相似文献
50.
W. Austin Spruill Alton L. Steiner Laura L. Tres A. L. Kierszenbaum 《Molecular and cellular biochemistry》1984,60(2):147-157
Summary Protein-bound cyclic AMP (cAMP) levels in cultured rat Sertoli cells have been determined after exposure to follicle-stimulating hormone (FSH) and agents which elevate intracellular cAMP or mimic cAMP action. Changes in the content of protein-bound cAMP were correlated with changes in receptor availability determined by measuring [3H] cAMP binding. Using the photoaffinity analog of cAMP, 8-N3 [32P] cAMP, two major cAMP-binding proteins in Sertoli cell cytosol, with molecular weights of 47 000 and 53 000 daltons, were identified as regulatory subunits of type I and type II cAMP-dependent protein kinases, respectively. Densitometric analysis of autoradiograms demonstrated differential activation of the two isozymes in response to treatment with FSH and other agents. Results of this study demonstrate the value of measuring changes in protein-bound cAMP and the utility of the photoaffinity labeling technique in correlating hormone-dependent processes in which activation of cAMP-dependent protein kinase occurs. 相似文献