Fitting the determined impedance in the guinea pig inner ear to Randles circuit using square error minimization in the range of 100 Hz to 50 kHz.

Objective. Several lumped and distributed parameter models of the inner ear have been proposed to improve vestibular implant stimulation. The models should account for all significant physical phenomena that influence the current propagation, such as the electrical double layer (EDL) and medium polarization. The electrical properties of the medium are reflected in the electrical impedance; therefore, the study aimed to measure the impedance in the guinea pig inner ear and construct its equivalent circuit.Approach. The electrical impedance was measured from 100 Hz to 50 kHz between a pair of platinum electrodes immersed in 0.9% NaCl saline solution using sinusoidal voltage signals. The Randles circuit was fitted to the measured impedance in the saline solution in order to estimate the EDL parameters (C,W,andRct) of the electrode interface in saline. Then, the electrical impedance was measured between all combinations of the electrodes located in the semicircular canal ampullae and the vestibular nerve in the guinea pigin vitro. The extended Randles circuit considering the medium polarization (Ri,Re,Cm) together with EDL parameters (C,Rct) obtained from the saline solution was fitted to the measured impedance of the guinea pig inner ear. The Warburg element was assumed negligible and was not considered in the guinea pig model.Main results. For the set-up used, the obtained EDL parameters were:C=27.09*10-8F,Rct=18.75kΩ.The average values of intra-, extracellular resistances, and membrane capacitance wereRi=4.74kΩ,Re=45.05kΩ,Cm=9.69*10-8F,respectively.Significance. The obtained values of the model parameters can serve as a good estimation of the EDL for modelling work. The EDL, together with medium polarization, plays a significant role in the electrical impedance of the guinea pig inner ear, therefore, they should be considered in electrical conductivity models to increase the credibility of the simulations.

[Vector systems and rhythms in movements and orientation of elk (Alces alces L.) and other wild animals (Mammalia)]. / Vektornye sistemy i ritmy v peremeshcheniiakh i orientatsii losei (Alces alces L.) i drugikh zverei (Mammalia).

The orientation of elk and other mammals studied in fields with visual and instrumental tracing has obviously hierarchical organization. Animals usually choose general direction headed for distant markers and then select short-distance landmarks. Movements of animals to distant and close landmarks is characterized by almost constant or regularly changing angles between main direction and movement vector. Fragments of trajectories represent left-side or right-side spirals with decreasing or increasing curvature according to the main direction. Three types of spirals differed by average values of initial angles are considered. Orientation to distant landmarks or along direction of movement possesses discrete reaction on the given landmarks and has some characters of iteration process. Special rhythms of activity (rhythms of orientation changing) participate in regulation of changing of movement directions and orientation reactions. They take part in formation of sinusoid, spiral and other trajectories. Rhythmic regulation involves great statistical variability of parameters (lengths, angles, time periods between consecutive orientations) that can be adaptive meaning. Lengths of orientation vectors and trajectory fragments are similar to some linear elements of landscape. Angular parameters of orientation are more variable. The main ones are similar to the angular parameters of Earth rotation. It looks, that orientation parameters evolved under the influence of Sun-Earth compass in inertial field of Earth rotation.

[Treatment in diffuse phlegmons of the neck]. / Lechenie pri razlitykh flegmonakh shei.

The authors made an analysis of results of treatment of 146 patients with diffuse phlegmons of the neck. The use of cryoplasmic-antifermentative complex and plasmapheresis in complex treatment allowed to increase the efficiency of pathogenetic therapy for phlegmons of the neck and contact mediastinitis, to improve the entry of antibiotics and enzyme inhibitors into the inflammation focus and to get better results of treatment.

[Indirect electrochemical oxidation of blood plasma in combined treatment of patients with acute mediastinitis]. / Nepriamoe élektrokhimicheskoe okislenie plazmy krovi v kompleksnom lechenii bol'nykh ostrym mediastinitom.

Treatment results in 61 patients with acute mediastinitis are analyzed. Combined treatment of acute mediastinitis, including cryoplasma-antienzymic complex use and indirect electrochemical blood plasma detoxication, promotes disappearance of microcirculation disorders, to earlier decreasing of endogenic intoxication, outcomes improvement.

[The effect of the gas hypoxic mixture GHM-8 on the capacity of the stromal clonogenic cells (CFU-F) in rat bone marrow for postradiation recovery]. / Vliianie gazovoi gipoksicheskoi smesi GGS-8 na sposobnost' stromal'nykh klonogennykh kletok (KOE-F) kostnogo mozga krys k postradiatsionnomu vosstanovleniiu.

The effect of gas hypoxic mixture, containing 8% of O2 (GHM-8), on the ability of cell precursors of haemopoietic stroma (which form colonies (clones) of fibroblasts (CFU-F) in a culture, and are present in the bone marrow of adult rats) to repair potentially lethal and sublethal radiation damages has been investigated. The recovery of CFU-F from potentially lethal damages, that was studied after their delayed survival in a culture following irradiation of animals, proceeds at nearly the same rate in cells irradiated both in the air and in hypoxic conditions (GHM-8). Fractionated irradiation reduces the radioprotective effect of GHM-8 for CFU-F, particularly for the radioresistant subpopulation; the ability of CFU-F to recover from sublethal radiation damages decreases.

[The functional status of the hypophyseal-adrenal cortical adaptation system in children in Byelarus living under the action of low doses of radiation after the accident at the Chernobyl Atomic Electric Power Station]. / O funktsional'nom sostoianii gipofizarno-kortikoadrenalovoi sistemy adaptatsii detei Belarusi, zhivushchikh v usloviiakh deistvii malykh doz radiatsii posle avarii na ChAES.

The analysis of the status of sympatho-adrenal and hypophysis-adrenal medulla systems of adaptation in children living in territories contaminated by radionuclides was carried out. A decrease in the catecholamine level in children's urine and hyperactivity of the hormonal response of adrenal medulla to endogenous ACTH indicated the reduced ability of adaptation and decreased resistance of children's organisms to stress factors of the environment.

[The synchronization of behavior and individual distances in groups of wild boars (Sus scrofa L.)]. / Sinkhronizatsiia povedeniia i individual'nye distantsii v gruppakh kabanov (Sus scrofa L.).

Some ways of synchronization are identified in the wild pig behaviour, which are parallel body orientation, group getting together and away, individual approaching and moving away, sound signals. Parallel synchronization is characteristic for various compact groups, males and females exposing some differences in the synchronization duration and distances. The synchronization is mainly a property of individuals united by common motivation and interests. Each family union, each offspring group have their own peculiarities of synchronization depending on their structure. Synchronization duration and distances vary by season, while within- and between-group distances are different in ages and sexes. Two ways of appearance of special distances are recognized. The synchronization works as a trigger system regulation spatial distribution of individuals and various social functions.

[Binding of SSB-protein from Ehrlich ascites carcinoma cells with DNA and polyribonucleotides]. / Sviazyvanie SSB-belka iz kletok astsitnoi kartsinomy érlikha s DNK i poliribonukleotidami.

Binding of SSB-protein from Ehrlich ascites tumor to ssDNA from M13 phage leads to its compactization. The structure of the complex at the protein/DNA ratios far from the saturation level looks like "beads-on the string". DNA that was fully saturated with protein forms collapsed globular structure. Binding of the protein to the dsDNA from phage lambda increases its flexibility and decreases the coil dimensions; no "beads-on the string" structure are seen. The protein possess slight destabilizing effect on hairpin helices of M13DNA. Competition studies demonstrate that the binding properties of protein with polyribonucleotide lattices and DNA's decrease in ranking as follows: poly(rG) greater than or equal to poly(rI) greater than or equal to ssDNA greater than dsDNA greater than poly(rA) congruent to approximately poly(rU). Thus SSB-protein from Ehrlich ascites tumor differs significantly from its presumed prokaryotic analogs.

[Dynamics of the spectral-coherent characteristics of the human EEG in healthy subjects and brain pathology]. / Dinamika spektral'no-kogerentnykh kharakteristik EEG cheloveka v norme i pri patologii mozga.

EEGs of 15 healthy subjects and 30 patients in early period after surgical ablation of tumours with basal localization, were investigated by means of monitor "Neuro-1" which allows to obtain in continuous regime characteristics of EEG dynamics according to power spectra and reveal the characteristics of intercentral relations of electrical brain processes by coherence and phase shifts. In healthy subjects in the period of transition from wakefulness to drowsiness highly coherent beta-rhythm (16-18 Hz) was revealed, preceeding typical picture of drowsiness and sleep. Study of the patients shows that certain characteristics of coherence and phasic shifts have an important prognostic value. Conclusion is made that for estimation of the functional state of healthy subjects during transition from wakefulness to drowsiness and of patients in early postoperative period the data on spectra of coherence are most informative.

[Energy metabolism in spontaneous regression of transplantable tumors]. / Energeticheskii obmen pri spontannoi regressii perevivaemykh opukholei.

In spontaneous regression of rat sarcoma 45, Walker carcinosarcoma in rats and Brown-Pearce carcinoma in rabbits there was found biochemically and histochemically the enhancement of oxidation processes in the organism of animals, which was associated with the reduction of the ATP content, the increased rate of the coupling of oxidation to phosphorylation. Not only the normalization of all steps of the energetic provision chain in observed but also the exceeding of separate parameters of the energy homeostasis with relation to normal values.