Turkem jewellery is due to its high artistic quality considered the most valuable jewellery of the Central Asia. It is characterized by its robust, yet elegant form, combination of typical materials and distinctive processing techniques. The article deals with the Turkmen jewellery in the past (late 19th century – early 20th century) and the present. Attention is paid to the used material, technological proces, design and implementation of jewellery in everyday life. Jewellery workshop of the contemporary jeweller Murat Sakhatov from Ashgabat is also presented., Tereza Hejzlarová., and Obsahuje seznam literatury
The photosynthesis and related plant productivity aspects of plants and cyanobacteria depend upon the functioning of photosystem 2 (PS2), associated with D1 and D2 heterodimer reaction centre core proteins. The D1 protein is encoded by psbA gene, genetically localized on the plastid genome (cpDNA), contains functional cofactors of PS2 in association with D2 protein, and also functions for radiant energy transformation through oxidation of water and reduction of plastoquinone. Surprisingly, D1 protein accounts for even less than 1% of the total thylakoid membrane protein content. In spite of that, its rate of turnover is very much comparable to ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) large subunit, most abundantly present in green tissue. The normal functioning of PS2 possesses damage-repair cycles of D1 protein. Generally, rate of photodamage does not exceed the rate of repair under optimal growth conditions, therefore, no adverse effect on photosynthetic efficiency is manifest. However, under strong irradiance coupled with elevated temperature, level of photodamage exceeds the rate of repair, resulting in photoinhibition, photodegradation of D1 protein, and lowering photosynthetic efficiency linked with plant productivity eventually. The features of D1 turnover process are reviewed, particularly with respect to molecular mechanisms.