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31.
This paper considers the major patterns of downstream migration in Arctic lamprey ammocoetes in Kamchatka rivers. Ammocoetes of different age groups are shown to be constantly noted in the composition of the migrant part of a river community. The greatest intensity of downstream migration in ammocoetes of the age class 0+ is noted in the period of their primary dispersion in late July-early August. The ammocoetes of the age groups 1+ and older migrate from spring to late autumn, but their concentrations are not high. The significant similarity of such a biologic feature as downstream migration in ammocoetes and juvenile salmonids serves as an example of ecological analogy.  相似文献   
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Flow cytometry was used to analyse the free calcium content in leukocytes of peripheral blood in children with allergic diseases, both before and after contacting with allergens and mediators of anaphylaxis. Computer analysis with a special mathematical program was used to evaluate the gravity-centre coordinate of the histograms obtained. More than a 10% shift to the right on the X-axis was diagnosed as an increased sensitivity of peripheral blood cells to the allergens or mediators of anaphylaxis. Good correlations were obtained between our data and different provocation tests, usually used in practical allergology.  相似文献   
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Journal of Ichthyology - In order to extend the geography of genetic studies at the broad circumpolar range of Arctic charr we analyzed sequence variation of mtDNA control region (537–547...  相似文献   
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Fractionated polyuridylic acid with an average chain length of 55 nucleotides forms binary complexes with 30S subunits with a stoichiometry of I:I. These complexes are heterogeneous in stability. The more stable one is characterized by an association constant K2 - 5.5xI09 M-I, and the less stable-by KI = I06xM-I, at 20 mM Mg2+, 200 mM NH4(+) and 0 degrees C. The main reason for this heterogeneity is the presence or absence of the ribosomal protein SI in the presence or absence of the ribosomal protein SI in the subunits. Decrease of Mg2+ concentration down to 5 mM hardly changes the K2 values but reduction of the NH4(+) concentration to 50 mM results in a 25-fold increase of K2. Association constants K2 for the stable complex, i.e. in the presence of SI protein, were measured at different temperatures (0 - 30 degrees C) and the thermodynamic parameters of binding (delta H degrees, delta S degrees, delta G degrees) were determined. Analogous experiments were made with 70S ribosomes. K2 values as well as delta H degrees, delta S degrees, delta G degrees appeared the same both for 30S and 70S ribosomes in all conditions examined. This is strong evidence that the 50S subunits do not contribute to the interaction of poly(U) with the complete 70S ribosomes.  相似文献   
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The 30 S subunit contains 2 sites for tRNA binding (Phe-tRNA, AcPhe-tRNA, tRNAPheOH) with the functional properties of D and A sites of the 70 S ribosome after attachment of 50 S subunit. The third (E) site specific for deacylated tRNA is introduced into 70 S ribosome by its 50 S subunit. The E-site binding of tRNAPheOH is not sensitive to either tetracycline and edeine, and practically codon-independent. The affinity constant of tRNAPheOH for the E site is 2-3 orders of magnitude lower than that for the D site.  相似文献   
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Migratory behavior, size composition, and feeding patterns of the underyearlings of sockeye salmon Oncorhynchus nerka from different intraspecific phenotypic groups in the Ozernaya River basin are studied. Complex organization of main phenotypic groups is demonstrated: several labile spatial-temporal groups are defined within them. The discovered phenotypic polymorphism is temporal and manifested by the sockeye salmon underyearlings only during the period in which they reach the main rearing grounds.  相似文献   
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