The article attempts to reconstruct the patterns of perception documented in Bulgarian cultural texts which conseptualised the Bulgarian land as borderlands of civilisation. The author presents the historical and cultural conditions for the deliberate purification of the image of Balgarian culture as resistant to Ottoman influences which took place in 19th and 20th century. Futhremore, the article demonstrates the ways in which Bulgarian artists and thinkers conseptualised the observations and intuitions inconsistent with this understanding of the national idea.
Needle yellowing is a typical symptom of declíning spruce trees [Picea abies (L.) Karst.] which grow at altitudes over 700 m a.s.l. In tiie chloroplasts of yellowing needles the thylakoidal systém was reduced. The contents of chlorophyll (Chl) a, b, carotene (a + |3) and neoxanthin in the needles decreased simultaneously, while lutein and the pigments of the xanthophyll cycle were less affected. Activities of the xanthophyli cycle were inhibited only in the advanced stages of yellowing. Yellowing processes with comparable symptoms could be induced in artificial atmospheres, simulating realistic conditions of pollution. Possible mechanisms accounting for the yellowing process were examined. Fast yellowing events occurred not only under full sunlight, but also imder red radiation (X > 600 ran). Therefore, the excited Chl probably sensitized pigment destruction. As the light-harvesting C\ň-a/b- protein complex of Photosystem 2 lost its photo- and acid-stability before yellowing occiured, chloroplasts were changed from a photostable to a photolabile state.
Molecular modeling of the H4-H5-loop of the α2 isoform of Na+/K+-ATPase in the E1 and E2 conformations revealed that twisting of the nucleotide (N) domain toward the phosphorylation (P) domain is connected with the formation of a short π-helix between Asp369 and Thr375. This conformational change close to the hinge region between the N-domain and the P-domain could be an important event leading to a bending of the N-domain by 64.7° and to a shortening of the distance between the ATP binding site and the phosphorylation site (Asp369) by 1.22 nm from 3.22 nm to 2.00 nm. It is hypothesized that this shortening mechanism is involved in the Na+-dependent formation of the Asp369 phospho-intermediate as part of the overall Na+/K+-ATPase activity., G. Tejral ... [et al.]., and Obsahuje seznam literatury