Bioavailability of tetracycline hydrochloride capsules (an in vivo study)]

Blood absorption of tetracycline hydrochloride of various dispersity levels from capsules containing tetracycline alone or in combination with additives, such as magnesium carbonate and calcium salts was studied on humans. It was found that higher dispersity levels of tetracycline hydrochloride powder in capsules was not accompanied by increased blood absorption of the antibiotic. Addition of magnesium carbonate and calcium salts to the antibiotic in the process of capsulation markedly retarded the blood absorption. Clear correlation between the antibiotic dissolution rate in vitro and intensity of its blood absorption in volunteers was shown.     

Coevolution of life history traits and morphology in female subterranean amphipods

Subterranean species show a distinct morphology, yet the adaptive significance of some traits, like body size and shape, is poorly understood and cannot be explained solely by distinct environmental conditions (darkness, less food). We predicted that in females some morphological changes may have co‐evolved with life history traits, and that co‐evolving life history traits provide at least part of the explanation for evolutionary changes of morphology. Using museum material we tested this prediction on the subterranean amphipod genus Niphargus. We studied six species found in springs and eight species found in cave lakes. We treated them as two ecologically distinct groups, and the major ecological differences between them were the availability of nutrients and the water currents. Cave species were found to be larger and stouter (as inferred from the shape of coxal plates, which are part of the marsupium), they had larger eggs and lower reproductive effort per brood, whereas the egg number and brood volume if corrected for the body size were not different. Using phylogenetic independent contrasts, we found a positive correlation between body shape and egg volume, a positive correlation between body size and egg volume, and a negative correlation between body size and reproductive effort per brood. We tentatively conclude that evolutions of morphology and life histories are functionally connected and that co‐evolving traits contribute to overall selective regime.     

Basic principles of developing national standards for antibiotics

The main principles in preparation of national standards of the antibiotics manufacture in the USSR are compared with those of the World Health Organization. The characteristics of preparing standards of mono- and multicomponent antibiotics, as well as the requirements for optimal packing of the standards are presented.     

Creative dynamics approach to neural intelligence

The thrust of this paper is to introduce and discuss a substantially new type of dynamical system for modelling biological behavior. The approach was motivated by an attempt to remove one of the most fundamental limitations of artificial neural networks — their rigid behavior compared with even simplest biological systems. This approach exploits a novel paradigm in nonlinear dynamics based upon the concept of terminal attractors and repellers. It was demonstrated that non-Lipschitzian dynamics based upon the failure of Lipschitz condition exhibits a new qualitative effect — a multi-choice response to periodic external excitations. Based upon this property, a substantially new class of dynamical systems — the unpredictable systems — was introduced and analyzed. These systems are represented in the form of coupled activation and learning dynamical equations whose ability to be spontaneously activated is based upon two pathological characteristics. Firstly, such systems have zero Jacobian. As a result of that, they have an infinite number of equilibrium points which occupy curves, surfaces or hypersurfaces. Secondly, at all these equilibrium points, the Lipschitz conditions fails, so the equilibrium points become terminal attractors or repellers depending upon the sign of the periodic excitation. Both of these pathological characteristics result in multi-choice response of unpredictable dynamical systems. It has been shown that the unpredictable systems can be controlled by sign strings which uniquely define the system behaviors by specifying the direction of the motions in the critical points. By changing the combinations of signs in the code strings the system can reproduce any prescribed behavior to a prescribed accuracy. That is why the unpredictable systems driven by sign strings are extremely flexible and are highly adaptable to environmental changes. It was also shown that such systems can serve as a powerful tool for temporal pattern memories and complex pattern recognition. It has been demonstrated that new architecture of neural networks based upon non-Lipschitzian dynamics can be utilized for modelling more complex patterns of behavior which can be associated with phenomenological models of creativity and neural intelligence.