Large noncollinearity and spin reorientation in the novel Mn2RhSn Heusler magnet.

Noncollinear magnets provide essential ingredients for the next generation memory technology. It is a new prospect for the Heusler materials, already well known due to the diverse range of other fundamental characteristics. Here, we present a combined experimental and theoretical study of novel noncollinear tetragonal Mn(2)RhSn Heusler material exhibiting unusually strong canting of its magnetic sublattices. It undergoes a spin-reorientation transition, induced by a temperature change and suppressed by an external magnetic field. Because of the presence of Dzyaloshinskii-Moriya exchange and magnetic anisotropy, Mn(2)RhSn is suggested to be a promising candidate for realizing the Skyrmion state in the Heusler family.

[The correlation between fish growth and several biochemical characteristics by the example of the steelhead Parasalmo mykiss Walb].

Correlation analysis demonstrated a statistically significant correlation of linear-weight characteristics of the steelhead rainbow trout (cultivated steelhead form) with an RNA/DNA ratio and the expression level of the gene encoding cytochrome c oxidase (CO) in two-year-old individuals (1+) as well as the expression level of the gene encoding the myosin heavy chain (MyHC) and activities of the enzymes CO and lactate dehydrogenase (LDH) in muscles and 1-glycerophosphate dehydrogenase (1-GPDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) in the liver of two- and three-year-old individuals (1+ and 2+). With age, the correlation of 1-GPDH and G-6-PDH activities in the rainbow trout liver with the fish body weight increased, whereas their correlations with the body length reduced. The age- and sex-related distinctions in the MyHC gene expression and activities of the white muscle enzyme LDH and the liver enzymes 2-GPDH and G-6-PDH were detected in rainbow trout of both age cohorts.

[The prediction of resistance to emotional stress based on the individual testing of behavior]. / Prognozirovanie ustoichivosti k émotsional'nomu stressu na osnove individual'nogo testirovaniia povedeniia.

On the basis of the elaborated experimental model for testing of emotional interaction of animals individual typification of behaviour was established according to which all experimental male rats of August line were subdivided into groups: I--rats manifesting behaviour of avoidance, "victims" of electrocutaneous stimulation; II--without definite behaviour with respect to the "victim" rat; III--rats, preferring the behaviour determining electrocutaneous stimulation of the "victim" rat. All typified animals were subjected to emotional stress with the use of the elaborated experimental model of aggressive-conflict behaviour. Stability against emotional stress of each group of animals was studied. Significant differences were established of stability degree to emotional stress of the rats of three groups manifesting different types of behavioural reaction in conditions of emotional interaction. The most stable were rats of the I group, the least--of the III group; rats of the II group were in the middle position. Typification on the basis of testing of emotional interaction of animals allows to prognosticate individual stability against emotional stress.

[An experimental model for testing the emotional interactions of animals]. / Eksperimental'naia model' dlia testirovaniia émotsional'nogo vzaimodeistviia zhivotnykh.

A new experimental model has been worked out for testing of animals emotional interaction; it represents a maze, consisting of two start chambers, passages and central chambers. Individual testing of animals behaviour was carried out on the basis of recording of active preventing of electrocutaneous stimulation of another animal, which was realized in the maze by means of choice by the tested animals of one of two possible movement directions excluding electrocutaneous stimulation of the animal-victim in the central chamber. The experiments were carried out on 35 male Wistar rats. As a result the animals were divided into three groups according to their behaviour type--per cent of running delivering the rat-victim from the electric current. The elaborated model has revealed a high precision of typification at testing of the individual behaviour in conditions of rats emotional interaction and it may be used for individual behavioural tests of other small laboratory animals.

[Effects of colchicine, cyclic nucleotides and biogenic amines on the chemoreceptor apparatus of the tongue]. / Vliianie kolkhitsina, tsiklicheskikh nukleotidov i biogennykh aminov na khemoretseptornyi apparat iazyka.

Colchycine considerably decreased sensitivity of the Rana temporaria tongue's chemoreceptors to adequate stimulation. The effect is reversible and can be abolished by administration of drugs initiating setting of the cells' microtubular apparatus: 3',5'-cAMP, theophylline, adrenaline as well as by activation of the sympathetic system. The restoring effect of these agents is specific since 2',3'-cAMP, 5'-AMP, serotonin, inosine, acetylcholine and 3,'5'-cGMP prove ineffective in restoring the reactions after colchycine administration although they do alter the activity of the receptors in normal conditions. The revealed colchycine-sensitive, 3',5'-cAMP-dependent process seems to be associated with the microtubular apparatus of the receptor cell. Its role in the receptor structures is discussed.

[Comparative evaluation of carbohydrate metabolism in perch (Perca fluviatilis L.) from water bodies with different contents of humic acids]. / Sravnitel'naia otsenka uglevodnogo obmena okunei (Perca fluviatilis L.) iz vodoemov s razlichnym urovnem soderzhaniia guminovykh kislot.

Characteristic features of energy metabolism, related to the adaptation of fish to adverse environmental conditions, were detected in perch (Perca fluviatilis L.) inhabiting the lake with a high humus content, compared to perch from the control lake. We studied a complex of enzymes involved in carbohydrate metabolism and assessed the relationship between metabolic pathways using correlation analysis. The intensity of oxidative metabolism was greater in the gulls. The activation of energy metabolism in the liver was characterized by an increased consumption of carbohydrates. In addition, the role of the liver-specific lactate dehydrogenase (LDH) isoform D4 also increased. The activity of enzymes involved in carbohydrate metabolism decreased most strongly in white skeletal muscles, whereas the role of the pentose-phosphate pathway (along with glycolysis) in the production of muscle lactate increased. The adaptation of fish to a high-humus aquatic environment was accompanied by a slight decrease in their fatness.

[Effect of antibodies against tubulin on the activity of taste receptors]. / Vliianie antitel protiv tubulina na aktivnost' vkusovogo retseptorogo apparata.

Electrophysiological studies were carried out to investigate the effect of monospecific tubulin antibodies on the activity of the receptor gustatory apparatus of Rana temporaria under adequate stimulation of receptors with NaCl and glucose solutions and water. There was a significant decrease in receptor responses to NaCl and water stimulation after administration of antibodies. Glucose responses were less prone to the effect of antibodies. The authors discuss the mechanism of the involvement of the microtubules-tubulin system found in receptor formations into the peripheral mechanisms of chemoreception.

[Recovery of colchicine-blocked chemoreceptor reactions of the frog tongue as affected by electrical stimulation of the sympathetic nervous system]. / Vosstanovlenie zablokirovannykh kolkhitsinom reaktsii khemoretseptorov iazyka liagushki pod vliianiem élektricheskogo razdrazheniia simpaticheskoi nervnoi sistemy.

Under adequate stimulation of tongue chemoreceptors with feeds synchronous recording of the total afferent impulse activity of the glossal branches of Rana temporaria glossopharyngeal nerves was used to demonstrate the facilitation effect of electric stimulation of the I sympathetic ganglion on the receptor reactions in health and after treatment with colchicine provoking a considerable weakening of the reactions. The data are discussed in the light of the adaptation-trophic effect of the sympathetic system at the level of molecular-metabolic intracellular processes. No poisoning effect of alkaloid on the sympathetic fibers has been recorded.

[Increasing resistance to emotional stress by endogenous peptide prolactin]. / Povyshenie ustoichivosti k émotsional'nomu stressu s pomoshch'iu éndogennogo peptida prolaktina.

In real work we studied ability of endogenic peptide prolactin to raise the resistance of emotional stress under existing conditions of experimental model. Emotional stress was formed in the course of 5 days during 5 hours with fixation of groups of rats. All experimental animals were divided into three groups. The experiments showed the ability of the prolactin to raise the resistance of emotional stress.