[Ecological aspects of myasthenia gravis in the Orenburg region].

The paper reflects the problem of adverse environmental factors on human health, including those on the prevalence of myasthenia and on the blood levels of trace elements in the patient. It outlines the environmental status in the Orenburg Region, which is most unfavorable in the Eastern and Central areas. Myasthenia morbidity trends for its increase are covered in 1967 to 2006.

[Automated genetic register and computer support for the physician's diagnostic decisions].

Computer-based genetical register "GENREG" allows to carry out a prophylactic medical examination for families with children, having hereditary diseases, multifactorial pathology and congenital developmental defects of various nature, and also epidemiological examination. Automated consultative system for pre-laboratory diagnosis of genetically determined diseases after the phenotypical manifestations "DIAGEN" allows to identify up to 1200 nosologic units; diagnostic value (or weight) of the signs according to physician's evaluation is taken into consideration. The system sorts out a narrow differential-and-diagnostic row and information about specific laboratory and functional changes for every selected diagnosis.

[An automated system of preventive care of the juvenile population: structure and functions].

Automated system of prophylactic medical examination to be used on three levels of service, with a polyclinic as a starting point. The developed system includes: management of preventive check-ups, formation of groups with risk for pathologic conditions and management of a second-time medical examination. Use of this medico-technological system, according to its results, permits to increase the effect and purposefulness of prophylactic medical examinations in children.

[Description of electromyograms using a mathematical model of single joint movement].

A mathematical model for motor control over one-joint fast and slow movements is proposed based on the equilibrium point (EP) hypothesis. Equations describing a reaction of the muscle with its servo to an EP shift are presented. EMG level is estimated as a function of kinematic and control variables.

[A model of control of the movement of the multiarticular extremity].

A model for coordinated execution of multijoint goal-directed limb movements is suggested from the following principles. (1) Central control signals for a single limb joint are individually formed, proceeding from its ability to bring the limb nearer to the target and leaving control signals directed simultaneously to other joint out of account. The joints thereby behave as a set of Tsetlin's abstract automata [11], each functioning independently and guided by a common, collective effect.

[Biomechanical characteristics of the wiping reflex cycle].

Multijoint goal-directed hindlimb movements in response to chemical stimulation delivered to different skin sites on the medial back surface (wiping reflex-WR) were filmed and analysed in spinal or intact frogs Rana temporaria. Each WR cycle was divisible into five phases (flexion, lifting, aiming, wiping and extension) usually separated from each other by postural interruptions. One or several of the phases might spontaneously be reduced or deleted at all (e.

[A model of central regulation of movement parameters].

The central processes responsible for a gradation of muscle torques or joint angles are suggested on the basis of the mass-spring hypothesis. Two fundamental commands (reciprocal and co- activative ) involved in the control over antagonist muscles are defined in terms of shifts of the so-called invariant characteristics (muscle torque vs joint angle). Each of the commands is graded by a neuronal ensemble arranged in line.

[A wave nature of the central regulation of the trajectory of the articular angle in man].

It is supposed that muscles of a single joint are controlled by a wave propagation of excitation along a central line-ordered neuronal ensemble. The number of steady active output ensemble neurons increases with wave-front displacement and the neurons discretely contribute to the motor command that is defined in terms of shifts of the so-called invariant muscle force-length characteristics. The terminal position of the wave front is responsible for the final angular limb position, whereas the wave velocity responsible for the peak movement speed.

Interaction of afferent and efferent signals underlying joint position sense: empirical and theoretical approaches.

A model of joint position sense is considered based on the concept that central motor commands are adequately expressed in terms of shifts of the so-called invariant length-tension characteristics for agonist and antagonist muscles. The main points of this concept are discussed to clarify them and to prevent misunderstanding. The basic idea of the model is that the efferent copy of the central motor commands plays the role of a reference frame for evaluation of afferent proprioceptive discharges.

[Locomotion of Barents Sea ophiuroids].

Locomotion of 5 species of Ophiuroids from the Barents Sea has been described--Ophiura albida, O. robusta, O. sarsi, Ophiacantha bidentata, Ophiopholis aculeata.

[Modulation of Renshaw cell activity during scratching].

The activity of the Renshaw cells was recorded during fictitious scratching in 7 decerebrated and 1 spinal curarized cats. The flexor and extensor Renshaw cells were identified according to the responses induced by orthodromic stimulation of muscle nerves. Before the beginning of rhythmical oscillations, the background activity of the flexor Renshaw cells was inhibited.

[Variations in the membrane potentials of motor neurons during the generation of scratching].

The activity of motoneurons of the ankle flexor and extensor muscles was recorded intracellularly during fictitious scratching in decerebrate curarized cats. Before the beginning of rhythmical oscillation a large depolarization and tonic discharge were observed in flexor motoneurons, while the membrane potential of extensor ones did not change. When the rhythmical generation began, a short periodic hyperpolarization and corresponding pause in the discharge lasting for the extensor phase of the cycle appeared in flexor motoneurons.

[Activity of propriospinal neurons in cats during the scratch reflex].

In the thalamic cats immobilized with flaxedil, the tactile stimulation of the pinna evoked fictitious scratching, i.e. rhythmical activity of the hindlimb motoneurons with a pattern of discharge typical of the actual scratching.

[Turning over in the ophiuroid Amphipholis kochii].

The reaction of turning over in the ophiuroid A. kochii Lütken begins when the ambulacral legs are detached from the substrate. At the bottom, when aboral side of the animal touches the substrate, turning over begins with oral flexion of three arms.

[Moments in human leg joints during walking].

An automated method is developed to obtain the moments of internal forces in the leg joints during walking. A considerable variability of joints moments is observed, which sufficiently exceeds that of the kinematic parameters of walking. For normal walking three different types of joints moments can be distinguished.

[Coordination of the movement of the tube feet and arms of ophiurae during locomotion].

A role of the tube feet is considered for locomotion of ophiura Amphipholis kochii. During stepping, a tube foot sticks to the ground at its front position, and comes unstuck at the end of the step when reaching a certain hind position (relatively the direction of locomotion). Such an organization of the tubefoot mechanisms of stepping simplifies considerably the cooridination of tube feet and arms movements.

[Coordination of arm movement during locomotion in Ophiuroidea].

Ophiura Amphipholis kochii Lütken can move with any one of five arms directed forwards; therefore, each arm performs various functions during locomotion. The arm amputated together with the adjoining part of the central nervous ring is capable of complicated behaviour, particularly, of locomotion. Transection of the central nervous ring results in disturbances of the arms coordination.

[Types of locomotion in Ophiuroidea].

Locomotor movements of two species of ophiura from the Sea of Japan: Ophiura sarsi vadicola Djakonov and Amphipholis kochii Lütken, were filmed. Ophiura sarsi moves by means of two symmetric pairs of arms which perform rhythmical rowing movements, the fifth arm is passive and directed backwards. Animals of this species do not use tube feet in locomotion.