[Passive hearing stability in the bottle-nosed dolphin Tursiops truncatus to low frequency noise spectrum deformation].

In behavioral experiments on bottle-nosed dolphins there was evaluated efficiency of identification of the low frequency noises that represent a certain rhythmical sequence of impulses, at destabilization of their spectra by method of frequency wobble. Results of the experiments have shown that disturbance of spectra structure at erosion of its discrete components does not lead to a decrease of efficiency of the noise identification, which indicates the greater significance of the time, rather than spectral mechanisms at processing of the complex acoustic signals by the dolphin auditory system.

[Recognition of classes of noise-like signals by dolphins Tursiops truncatus].

The ability of the auditory system to perceive and to classify the noise-like signals imitating natural sea noises has been studied in dolphins Tursiops truncatus. Results of the studies carried out in a sea bay at free movement of the animals have shown that dolphins are able to determine noise-like signals and to ascribe them to a certain class by using invariant characters, such as rhythmical sequence of impulses, regardless of the frequency-time scale of the signal presentation.

Mechanisms by which dolphins identify target movement characteristics and their technical use in hydrolocation and radiolocation.

The ability of the localizing system of the dolphin Tursiops truncatus to discriminate the dynamic characteristics of an object being located (a radially moving target) was studied. Measurements were made of the thresholds of the animals' sensitivity to the target speed (2.6 cm/sec) and acceleration (0.6 cm/sec(2)). For location of a target moving at constant speed, dolphins were found to use probe signals consisting of two impulses, while accelerating targets were located using probe signals consisting of three impulses. These characteristics were used to propose new and highly effective technical methods for hydrolocation and radiolocation.

[Mechanisms of determining target locator velocity by dolphins and technical applications in hydrolocation and radiolocation].

Dolphin's (Tursiops truncatus) capacity to discriminate between dynamic characteristics of the object location (the target moving radially) was studied. The dolphin sensitivity thresholds for target velocity (2.6 cm/s) and for target acceleration (0.6 cm/s2) were measured. It has been shown that the animal emits two-pulse probe signal to locate the target moving with constant velocity, or three-pulse probe signal--to locate the accelerated target. New highly efficient technical methods of hydro- and radiolocation were suggested on the basis of these peculiarities.

Results of primary reconstructions in patients with lesion of the tibial arteries.

An analysis was made of 146 primary reconstructions performed in 141 patients with occlusion of the arteries of the femoropopliteal segment and leg. At the hospital stage an improvement of the clinical status was attained after primary operations in 98% of cases. The five-year cumulative bypass patency after operations.accounted for 43.5% while the limbs could be saved in 91.5% of cases. The results obtained in patients with stage 2B chronic arterial ischemia (according to the A.V.Pokrovsky classification, 1979) coincided with the results of bypass grafts of the popliteal artery (the 5-year patency was 56.9% with the limbs saved in - 81.2% of cases), whereas the results of in situ vein bypass were marked by a significantly better cumulative patency in the long-term period.

[Surgical treatment of abdominal aortic aneurysm in a patient with a horseshoe kidney (a case report)]. / Khirurgicheskoe lechenie anevrizmy briushnoi aorty u bol'nogo s podkovoobraznoi pochkoi (klinicheskii sluchai)..

This paper describes a clinical case of the treatment of a patient with associated abdominal aortic aneurysm and a horseshoe kidney. Examination revealed type II blood supply of the horseshoe kidney according to Crawford. The operation was performed from thoraco-phreno-lumbotomy on the left. During operation, we ligated the accessory renal artery with a good retrograde blood flow, branching out just from the aneurysmal sac. Examination carried out in the early and long-term postoperative period did not discover renal malfunction as shown by laboratory and radionuclide research methods.

[The structural characteristics of the echolocation signal in the beluga whale Delphinapterus leucas]. / Osobennosti struktury ékholokatsionnogo signala del'fina Delphinapterus leucas.

The sounding signal analysis of beluga dolphin under aquatory adaptation with orientation reflexes has been conducted. It has been shown that the single sounding orientation impulse of beluga has a complex structure. Its initial part consists of a large number of components and has a great power. The main part of impulse is frequency-modulated and has a large duration and constant amplitude. The spectral analysis of beluga's signal demonstrates the low-frequency character with spectrum maximal of 1.6 kHz.

[Dosage loads on the bone marrow in exposure to ionizing radiation]. / Dozovye nagruzki na kostnyi mozg pri vozdeistvii ioniziruiushchego izlucheniia.

The authors made calculations of the expected dose loads on the bone marrow in the population of several regions due to the disaster release of radionuclides at the Chernobyl Atomic Station as well as in professional groups subjected to ionizing radiation, in particular, those working with radium light-compounds of permanent effect. The dose loads were largest in the population of the Byelorussian ecological region. Persons working in conditions of ionizing radiation showed a functional insufficiency of hemopoiesis in correspondence with the doses but there was no synchronicity in the responses of the bone marrow and peripheral blood.

[Bone marrow tissue doses in various types of radiation exposure]. / Kostnomozgovye tkanevye dozy pri razlichnykh vidakh radiatsionnogo vozdeistviia.

Basing on some literature data and their own results, the authors calculated bone marrow radiation doses in global fallouts, medical x-ray investigations, a radionuclide fallout during the Chernobyl accident, and under occupational conditions during exposure to radiation factors of luminous compounds of permanent action (LCPA). Functional insufficiency of hemopoiesis and the absence of synchronization in bone marrow and peripheral blood responses to radiation exposure were revealed in professionals, working in contact with LCPA in correlation with doses of external inhomogeneous gamma-beam irradiation.

[The cellular sensitivity of the primary tumor and its metastases in breast cancer patients to cytostatics, interferon and tumor necrosis factor]. / Issledovanie chuvstvitel'nosti kletok pervichnoi opukholi i metastazov u bol'nykh rakom molochnoi zhelezy k tsitostatikam, interferonu i faktoru nekroza opukholei.

Samples of tumor tissue obtained from 47 patients with primary and metastatic breast cancer were implanted under the renal capsule of mice (SRCA-test) to assess individual sensitivity of these malignancies to cytostatics, recombinant interferon (rIFN) and--in some cases--to tumor necrosis factor (TNF). Primary tumor was shown to respond to cytostatics and rIFN in as few as 33.3 and 26.7% of cases, respectively. Xenografts of metastases displayed higher rates of response to all the drugs studied, viz. 64.2, 86.7 and 90% for cytostatics, rIFN and TNF, respectively.