THE COMPARISON OF SOME CHARACTERISTICS OF ELECTRODELESS UHFD IN WAVEGUIDE AND OF DCD

No abstract availabl

Application of telecommunications technologies in the management of territories

© 2020 by ASERS® Publishing. All rights reserved. Contemporary management of territories cannot be imagined without the effective use of telecommunications technologies, which create conditions for the systematic and harmonious development of territories, as well as their identification in today’s global digital space. Besides, it should be noted that the existing management systems are largely outdated and ineffective for the modern globally progressive information environment and their full functioning. Based on the conducted expert survey, the authors identified tasks of implementing telecommunications technologies in the management of rural territories, users of telecommunications technologies used when managing rural territories, opportunities for positioning rural territories through telecommunications technologies, areas for implementing telecommunications technologies in the management of rural territories, as well as presented the experience of the EU countries in the development of rural territories based on the concept of the smart village

Studies on the semen biology and sperm cryopreservation in the sterlet, Acipenser ruthenus L.

The present study investigated motility, acrosome reaction, fertility and cryobiological parameters of the semen of the sterlet, Acipenser ruthenus L. Sperm motility persisted for about 4 min in water, and the main swimming type was the linear motion. Motility was prolonged at osmolalities of 12.5 mosmol kg(−1) and in the presence of magnesium ions, while calcium had no effect. Also a pH in the range of 7.0–9.0 had no effect on ` motility. At osmolalities of 25–50 mosmol kg(−1) the sperm motility was partly inhibited, at osmolalities of 100 mosmol kg(−1), completely and irreversibly. In 50 mosmol kg(−1) solutions with 2.5–5 mM L(−1) KCl the motility inhibition was total, but reversible. The acrosome reaction was not induced by one of the described solutions, but the percentage of spermatozoa with reacted acrosomes was low (<20%) and highly variable in all experiments. The optimal extender base for cryopreservation was a solution consisting of 50 mM L(−1) NaCl, 5 mM L(−1) KCl, 10 mM L(−1) Tris (pH 8.5). From the tested cryoprotectants only dimethylsulphoxide (DMSO) and methanol provided sufficient cryoprotection. After freezing and thawing, the motility rates and swimming velocities were higher with DMSO than with methanol. However, the fertility was very significantly reduced with DMSO (10.3±0.5%) while with methanol fertilization rates in a similar range (32.7±4.4%) as with fresh semen (33.90±0.8%) could be obtained. Optimal freezing conditions for sterlet semen were in the vapour of liquid nitrogen 3–5 cm (−95°C to −85°C) above its surface, the optimal thawing conditions at 25°C for 30 s. The acrosome reaction was not induced by these cryopreservation protocols