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Nestbox provision is a technique used to increase nest-site availability for secondary cavity-nesting birds. However, little is known about the demographic consequences of nestbox provision in different habitat types. To assess how nestbox provision affects the density of hole-nesting birds simultaneously in two contrasting habitats, we compared the breeding density of Great Tits along transects without nestboxes with that in transects where nestboxes were provided. Although the initial density of breeders was considerably higher in the deciduous habitat than in the coniferous habitat, provision of nestboxes increased density by a similar number of additional pairs in each habitat type. Thus, the provision of nestboxes in managed coniferous forests may be as effective in increasing the breeding opportunities of cavity nesters as in deciduous stands. Moreover, previous research showed that pairs in deciduous habitat with nestboxes have consistently lower breeding success than those in coniferous habitat with nestboxes. It is possible that the addition of nestboxes in the preferred habitat increased density to such an extent that density-dependent effects became apparent.  相似文献   
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Catalytic activities of catalase (CAT) immobilized on graphite--GMZ, soot--"NORIT" and "PM-100" to mediate decomposition of 3-Cl-C6H4COOOH (3-CPBA) in acetonitrile have been investigated. Under these conditions, the kinetic parameters Km, k, Ea, Vmax, and Z0 were calculated. Conclusions on a probable mechanism of the catalytic process observed were drawn from the calculated values of deltaG*, deltaH*, and deltaS*. A quantitative UV-spectrophotometrical approach was used as the basic analytical tool. The electrochemical reduction of oxygen generated in enzyme catalysed 3-CPBA decomposition was examined with polarization curves method.  相似文献   
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Glucose oxidase (E. C. 1.1.3.4) was immobilized on electrochemically modified graphite to obtain an enzyme electrode. The working surface of the electrode was coated with gelatine to prevent desorption of the enzyme. In substrate (glucose) solutions the amperometric signal of the enzyme electrode was due to the electroreduction of H202 generated in the enzyme layer. The linearity of the electrode response was found up to a substrate concentration of 300 microM at a working potential of 0 mV (vs. Ag/AgCl). It was shown that the electrode did not respond to L-ascorbic and uric acid at that working potential. The response time was about 2 min. The enzyme electrode keeps about 50% of its initial activity after a one-week storage at 4 degrees C.  相似文献   
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Rapid progress in genome research creates a wealth of information on the functional annotation of mammalian genome sequences. However, as we accumulate large amounts of scientific information we are facing problems of how to integrate and relate the data produced by various genomic approaches. Here, we propose the novel concept of an organ atlas where diverse data from expression maps to histological findings to mutant phenotypes can be queried, compared and visualized in the context of a three-dimensional reconstruction of the organ. We will seek proof of concept for the organ atlas by elucidating genetic pathways involved in development and pathophysiology of the kidney. Such a kidney atlas may provide a paradigm for a new systems-biology approach in functional genome research aimed at understanding the genetic bases of organ development, physiology and disease.Key Words: EuReGene, kidney, genome, development, pathophysiology, genetics  相似文献   
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