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Biomedical subjects

A A Smirnova

Publications and source records attributed to A A Smirnova.

At least 19 recordsLinked to original sources
PubMed2005

[Role of reflux in evolution and prognosis of acute thrombophlebitis of lower extremities varicose veins].

Role of venous reflux in evolution and prediction of acute varicotrombophlebitis (AVTP) has been evaluated with coloured duplex scanning performed as daily monitoring. It is demonstrated that venous reflux determines the direction and rate of thromb formation, it potential of embolism, promotes formation of floating thrombi. Study of venous reflux permits to predict the evolution of AVTP. It is one of the key elements which influences the thrombus formation and determines policy of treatment of varicose disease complicated with AVTP.

Aged↗
PubMed2003

Prototype symbolization in hooded crows.

Studies were undertaken to determine whether four crows previously trained to an image-based abstract selection rule could establish a relationship between the number of elements in a group and initially indifferent symbols (arabic numerals) and operate with these symbols, i.e., studies addressed the ability of these birds to symbolize. Unlike other similar studies, there was no use of special development of associative connections between the symbols and the corresponding arrays of elements, but conditions were created in which birds could observe these relationships on the basis of comparison with previously obtained information. Demonstration series were performed for this purpose, in which correct solutions by the crow resulted in receipt of a number of larvae corresponding to the number of elements in the array pictured or numeral imaged on the stimulus selected by the crow. Images belonged to the same category as the corresponding stimulus for selection (the second stimulus was another category): if the image was an array, then the corresponding picture for selection also bore an array, and vice versa. Crows could solve the task successfully by using an image-based selection rule. In test series, the image and both selection stimuli were initially from different categories: if the image was a numeral, then both selection stimuli were arrays, and vice versa. All four crows successfully coped with this task. Despite the absence of any similarity between the image and "correct" stimulus, they selected the array corresponding to the numeral and vice versa. It is suggested that the birds could achieve this result by comparing the information obtained during the presentation series--about the number of reinforcement units corresponding to each stimulus. Similar experiments showed that crows could use numbers to perform operations analogous to arithmetic addition.

Animals↗
PubMed2001

A large outdoor radial maze for comparative studies in birds and mammals.

For a comparative neurobiological analysis of spatial learning and memory, a large outdoor eight-arm radial maze was constructed which permits behavioral assessment of many avian and mammalian species both from the laboratory or the wild, using the same metric space and session schedules. It consists of a central part of 250cm diameter, and has arms of 650cm length, 170cm height and 80cm width. In order to determine appropriate training schedules for comparison of different species, we tested four mammalian and two avian species during 9-15 sessions: 18 albino rats (Rattus norvegicus), nine outdoors and nine in a conventional small indoor maze; six guinea pigs (Cavia porcellus); six rabbits (Oryctolagus cuniculus); five hedgehogs (Erinaceus europaeus); seven hooded crows (Corvus corone cornix) and six chickens (Gallus domesticus). Rats learned fast in both mazes yet significantly better in the large one. Good-to-excellent learning was also observed in juvenile rabbits and wild-caught crows, although the latter tended to avoid arms in the vicinity of the observer. Hedgehogs and chickens did not show significant learning as a group, but some individuals appeared to learn the task. Guinea pigs remained continuously passive and could not be trained. Thus, in spite of species-specific demands for reward, adaptation and pre-training, this type of radial maze permits to directly compare a wide variety of species. Such comparability is essential for an analysis of underlying neurobiological mechanisms.

Animals↗
PubMed2000

Use of number by crows: investigation by matching and oddity learning.

Hooded crows were trained in two-alternative simultaneous matching and oddity tasks with stimulus sets of three different categories: color (black and white), shape (Arabic Numerals 1 and 2, which were used as visual shapes only), and number of elements (arrays of one and two items). These three sets were used for training successively and repeatedly; the stimulus set was changed to the next one after the criterion (80% correct or better over 30 consecutive trials) was reached with the previous one. Training was continued until the criterion could be reached within the first 30 to 50 trials for each of the three training sets. During partial transfer tests, familiar stimuli (numerals and arrays in the range from 1 to 2) were paired with novel ones (numerals and arrays in the range from 3 to 4). At the final stage of testing only novel stimuli were presented (numerals and arrays in the range from 5 to 8). Four of 6 birds were able to transfer in these tests, and their performance was significantly above chance. Moreover, performance of the birds on the array stimuli did not differ from their performance on the color or shape stimuli. They were capable of recognizing the number of elements in arrays and comparing the stimuli by this attribute. It was concluded that crows were able to apply the matching (or oddity) concept to stimuli of numerical category.

Animals↗
PubMed1979

[Use of the bicycle ergometric test in the differential diagnosis of climacteric cardiopathy].

Bicycle ergometry on the "Elema" electrical bicycle ergometer was conducted on 6, patients of climacteric age (41 to 55 years) with pain in the region of the heart and ECG changes. The method made it possible to confirm the diagnosis of climacteric cardiopathy in 39 and to reveal climacteric cardiopathy and concurrent ischemic heart disease in 23 patients. It was noted that physical load had a favourable effect on processes of repolarization in the myocardium of patients with climacteric cardiopathy.

Adult↗
PubMed1976

[Characteristics of the course of pregnancy in women with heart defects].

In 33 patients with different forms of the cardiac valves lesion the specificity marking the course of atriomegalia was studied on the ground of clinical, roentgenological and functional findings. Unlike non-pregnant women with similar forms of the malady here intercurrent pulmonary hypertension during gestation was ascertained, this increasing the hazard of developing edema of the lungs. The authors give preference to delivery in these patients via natural maternal passages by employing the operation with application of obstetrical forceps.

Adult↗
PubMedDate not supplied

Quantitative evaluations in gray crows: generalization of the relative attribute "larger set".

Four gray crows were trained to choose the larger of two sets presented to them within the "1-12" range. The color, form, and size of the stimulus elements on cards, as well as the patterns of their disposition, were varied constantly during training, while at the same time prohibiting the use of extraneous features not relating to the number of elements. In order to exclude choice on the basis of the total area of the elements, series of presentations with variation of the ratio of the number of elements and their total area were carried out: in half of the presentations the larger set consisted of small elements, and the smaller set of large elements; in the second half, the reverse. In this range all of the birds demonstrated a high accuracy of evaluations (75.3 +/- 2.4%), including when there were minimal differences between the sets to be compared. Thus, in the "1-12" range, the crows were found to be capable of accurately comparing sets precisely on the basis of the number of elements in them. When a transition was made to a new "10-20" range, all of the crows demonstrated a successful transfer of the developed reaction (71.5 +/- 2.3%). However, when the ratio of the number of elements and their total area was varied, only two birds were able to cope with this task (71.9 +/- 3.6%). Overall, the results obtained indicate a capacity of crows for the formation of the concept "larger set," and are regarded as a manifestation of a high level of development of reflective activity.

Animals↗