The Preservation Of Artificial Cultures Of Moulds

Summary

The subtidal marine algal flora of Sullom Voe was reassessed in 1983 after an interval of ten years. Only a few changes in communities were detected; these, not surprisingly, were at sites of major coastal engineering works.     

Characterization Of The S' Subsite Specificity Of Trypsin

The S' subsite specificity of bovine trypsin has been studied by partitioning of o-nitrophenylsulfenyl-L-arginyl-trypsin (formed using o-nitrophenylsulfenyl-L-arginine alkyl esters as acyl donors) between various amino acid-derived nucleophiles and water. The data obtained from spectrophotometric measurements confirmed a preference of trypsin for arginine residues in the P'₁-position, which is less marked but quite similar to that of chymotrypsin. The amides of leucine, phenylalanine, methionine, threonine, lysine and valine are better for synthesis than the corresponding methyl esters, and show a moderate nucleophile efficiency, decreasing in that order. Amides of acidic amino acids and D-leucine were ineffective in forming the peptide bond, whereas norvaline amide and dipeptide amides lead to increased aminolysis.     

The Specificity Of Processes Of Motivational Conditioning In The Human Mind

The methodological principle of the objectification of needs, which in activity theory explains the ontological development of motivation (Leont'ev, 1975), is in need of concrete psychological development to ascertain what influences and mental processes give rise to such objectification. In terms of biological motivation, this question is made easier by the existence of a detailed system of data, accumulated in conditioning studies, concerning the acquisition of the capacity to activate a person by neutral stimuli. A psychological interpretation of these data purports to explain the fact that the conditioned response phenomenon indicates not only a redirecting of unconditioned responses toward new stimuli but also the genesis, in response to this stimulus, of subjective relations orienting the person toward influences relevant to his needs. Such an interpretation therefore helps to concretize the concept of the objectification of biological needs (Vilyunas, 1986. Pp. 154-74).     

Perception Of Color As A Function Of The Combined Effect Of The Surroundings And A Test Field

The wide variety of shades of color that a human being is capable of perceiving consists of pigment colors, a considerable number of which are colors with gray and black hues. Only some of this wide variety of colors may be reproduced by the use of isolated autoluminescent sources of radiation: colors with dark shades cannot be produced. Under what possible conditions, we may ask, can the entire range of pigment colors be reproduced by luminescent sources of radiation?     

The Formation Of A Behavioral Act: The Problem Of Intrasystemic Heterochronicity

Among the timely questions facing contemporary physiology, study of the laws of formation of new behavioral acts in learning by human beings and animals is one of the most important. The general theory of functional systems has made a substantial contribution to resolution of this problem [1-6]. According to this theory, human and animal behavior are based on the formation of special physiological integrations, selectively uniting central and peripheral components of the organism to achieve an overall adaptative result. It was found that such functional systems, despite the considerable variability in their component composition, always have an invariable internal operational architectonics [5]. Their functioning always involves the same sequence of key mechanisms: processes of afferent synthesis and the system of the acceptor of the result of an action (ARA), the realization of an "executive act," the accomplishment of an adaptative result, and evaluation of its parameters.     

Observation On The Germination Of The Seeds Of Crinum Macowani,Baker

Arid and semi-arid areas occupy an increasing fraction of the Earth's surface. Legume floras exist for most of these areas, but there is little information as to whether the plants nodulate and fix nitrogen (N) in their native habitats, although many have been used over millennia for food, forage and medicinal and other uses.

This review shows that, in those arid and semi-arid areas where data are available, the ability of legumes to nodulate is a significant attribute. It examines some host genera present and, where known, the bacteria that induce nodulation in them.

With some exceptions all legumes from well-studied arid areas have the potential to nodulate. Semi-arid areas vary between continents in terms of legume genera present, the probable extent of N fixation and in the endosymbionts (rhizobia) that induce nodulation in them.

With climate change and an increasing world population, there is an urgent need to develop the diverse range of nodulated legumes native to dry environments. With modern methods this goal is readily achievable.