Search

Ukrainian breeders evolved and have been evolving meat breeds but at the same time in the nearest future the main part of beef will be produced in dairy cattle- breeding as a by-product of milk production. The aim of the research was to study the productive and technological qualities of the mixed breeds of cattle produced from crossing of the cows of the Ukrainian Red dairy breed with the bulls of meat breeds: Aberdin Angus, Ukrainian, Volynian and the Southern breed of Znamensky type. Scientific and production experiment was carried out on the research farm “Stepove” Kirovograd region, at the research agricultural station and 64 bulls of different breed combinations and 16 purebred bulls of Ukrainian Red dairy breed were taken for the experiment. The bulls under investigation were kept in accordance with the technology and the rules adopted on the farm, they were fed by the same diet. The ration of the bulls was balanced by the detailed standards (Kalashnikov, 1985) that provided the daily weight gains at the level of 900 g and more. The composition of the feeds was changed depending on the season of the year and the period of animal growing. The analysis of the change of the live weight of the young cattle kept in the similar technological conditions has shown that the animals of different genotypes had different dynamics of growth. One of the reasons for that was the fact that they had had different live weights at birth. The calves of Aberdin Angus mixed breed had the lowest live weight at birth (Р< 0,05), due to their high energy of growth they surpassed the animals of the control group in the live weight. They had the highest relative rate of growth from birth to 18-month-old age. The mixed bulls produced from the bull of the Ukrainian Red meat breed had the highest absolute weight gain (554,5 kg) and, respectively, the highest daily weight gain (1014 g). The data of the results of the slaughter proved high meat productivity of bulls in all the groups. All groups of mixed bulls had higher slaughtering output by 1,4-3,9% as compared to the bulls of the control group. As for the level of profitability of beef production even without donation the bulls produced from crossing the cows of Ukrainian Red dairy breed with the bulls of the Ukrainian meat breed had the best results (51,3%), the mixed bulls produced from crossing with Aberdin Angus breed had a little lower values (50,4%) than with Volynian meat breed (47,5%) and Znamensky type of the Southern meat breed (46,0%).

Silver nanoparticles are known to have inhibitory and bactericidal effects and they play a significant role in the development of new antimicrobial substances against a number of pathogenic microorganisms. In this article the minimum bactericidal concentration of the silver nanoparticles on two different bacteria cultures (Escherichia coli and Staphylococcus aureus) as well as the possibility to enhance their antimicrobial activity using laser irradiation was investigated. It was found, that solutions of silver nanoparticles at concentrations ≥ 3120 μg/ml cause death of both types of studied microorganisms. Dispersion of nanoparticles after laser irradiation caused the inhibition of Staphylococcus aureusat lower concentrations.

Cytoplasmic tyrosyl-tRNA synthetase (TyrRS) is one of the key enzymes of protein biosynthesis. TyrRSs of pathogenic organisms have gained attention as potential targets for drug development. Identifying structural differences between various TyrRSs will facilitate the development of specific inhibitors for the TyrRSs of pathogenic organisms. However, there is a deficiency in structural data for mammalian cytoplasmic TyrRS in complexes with substrates. In this work, we constructed spatial structure of full-length Bos taurus TyrRS (BtTyrRS) and its complexes with substrates using the set of computational modeling techniques. Special attention was paid to BtTyrRS complexes with substrates [L-tyrosine, K+ and ATP:Mg2+] and intermediate products [tyrosyl-adenylate (Tyr-AMP), K+ and PPi:Mg2+] with the different catalytic loop conformations. In order to analyze their dynamical properties, we performed 100 ns of molecular dynamics (MD) simulations. MD simulations revealed new structural data concerning the tyrosine activation reaction in mammalian TyrRS. Formation of strong interaction between Lys154 and γ-phosphate suggests the additional role of CP1 insertion as an important factor for ATP binding. The presence of a potassium-binding pocket within the active site of mammalian TyrRS compensates the absence of the second lysine in the KMSKS motif. Our data provide new details concerning a role of K+ ions at different stages of the first step of the tyrosylation reaction, including the coordination of substrates and involvement in the PPi releasing. The results of this work suggest that differences between ATP-binding sites of mammalian and bacterial TyrRSs are meaningful and could be exploited in the drug design.

Peripheral circulation can be divided in two components: continuous one, which includes continual fluctuation of muscular vessels diameters; and discrete one, which is caused by opening and closing of pre-capillary sphincters causes the activation-deactivation of capillaries. The state of each capillary sphincter depends on concentration of tissues vasodilator metabolites in the neighborhood of this capillary. Application of Cellular Automata simulation approach allows to study the behavior of separate capillary system as critically self-organized system and to investigate the different types of interaction between muscular arterial vessels and capillary network. Analysis of clinical data revealed significant difference in oxygen concentration in arterial and venous blood at normal conditions, at blood flow insufficiency conditions, and at hyperdynamic state of system circulation. This causes significant influence on fluctuation properties of capillary network and of tissues oxygen saturation. Depending on the state of system blood flow each capillary opens and closes at different thresholds of concentration of tissues vasodilator metabolites, closely correlated with tissues oxygen content. Different types of capillary network behavior have been simulated for various heart rhythm disturbances, which cause irregularity of fluctuations of system blood flow. Results of simulations were collated with clinical data and have a good correspondence with them. Regulation of peripheral circulation of blood includes its metabolically caused redistribution, stabilization of the main hemodynamic characteristics at the level of microcirculatory units and mass transfer inside them. The final stabilization of blood pressure occurs at the level of arterioles, then in microcirculatory unit performs a countertransport of oxygen and metabolites through the wall of the true capillary and arteriovenous shunting of blood (ChernukhA Rushmer, 1986, e.a.). The blood flow in arteries is studied in most detail (Achakri e.a. 1994, Cavalcanti & rsino, 1996; Little, 1989; Rushmer, 1986, e.a.). However, the integral properties of peripheral blood