Analysis of the ways of formation of the entomofaunistic complexes in the Northwest Caucasus based on the material on coleopterous insects (Coleoptera)

By the example of 14 coleopterous insect families, namely Gyrinidae, Haliplidae, Noteridae, Dytiscidae, Carabidae, Hydrophilidae, Staphylinidae, Lucanidae, Trogidae, Scarabaeidae, Elateridae, Alleculidae, Tenebrionidae, and Chrysomelidae, regularities and the basic sources of formation of the most typical landscapecoenotic complexes in the Northwest Caucasus are discussed. The total number of the species included in the material analyzed amounts to about 2000. The maximal species diversity (854 species) is registered for the deciduous forests and dry open woodlands. In total, 11 types of the chorological complexes and distributional ranges (chorotypes) of the regional beetle fauna are distinguished. Significant concordance of the chorologic patterns in some groups of beetles is established. In this respect, Carabidae and Tenebrionoidea seem to be the closest on the one hand, and also Elateridae and Scarabaeoidea, on the other. The zonal fauna of the Northwest Caucasus is formed basically by species possessing Boreal ranges, while the azonal fauna, predominantly by species with the Ancient Mediterranean ranges. Allocation of coleopterous insects within regional zoochorones is investigated as well. It is established, that in different zoochorones of the upland part of the region the majority of coenofaunas show significant similarity of the arealogical pattern, even though being composed frequently by different taxa. The fauna of agrarian landscapes of the Northwest Caucasus is also examined. It includes 382 beetle species. The overwhelming majority of them belongs to the ground beetles (229 species), leaf beetles (78), and Scarabaeoidea (30). This fauna reveals the maximal similarity with the coenofaunas of the lowland steppe and meadows. It is established that the major role in formation of the agrocenoses beetle fauna belongs to the natural plain and upland steppe and treeless fields, foothill broad-leaf forests and open woodlands, and also to the floodplain and lowland forests. The bulk of the species occurring in the agrocenoses possesses wide ranges, predominantly of the Boreal type. Some peculiarities of the regional endemism are discussed as well.     

Kinesins in the Arabidopsis genome: A comparative analysis among eukaryotes

Background  

Receptor protein tyrosine phosphatase rho (RPTPρ, gene symbol PTPRT) is a member of the type IIB RPTP family. These transmembrane molecules have been linked to signal transduction, cell adhesion and neurite extension. The extracellular segment contains MAM, Ig-like and fibronectin type III domains, and the intracellular segment contains two phosphatase domains. The human RPTPρ gene is located on chromosome 20q12-13.1, and the mouse gene is located on a syntenic region of chromosome 2. RPTPρ expression is restricted to the central nervous system.     

Freshwater testate amoebae in the Belaya River basin (Northwestern Caucasus)

Fifty-two species and intraspecific taxa of testate amoebae have been detected in 24 different habitats in the Belaya River basin (Northwestern Caucasus). Four types of communities are distinguished which differ in the composition of the complex of dominating species: freshwater species from bottom sediments in water bodies and water courses, soil-dwelling species from inundated parts of floodplains, a mixture of soildwelling and freshwater species in different littoral biotopes, and eurybiontic species in moss hummocks along the banks.     

Analogue model of motoneurons to investigate the distribution of synaptic inputs

Analogue models of lumbar motoneurons of the monkey and cat were built on the basis of measurement of the electrical parameters of these cells and reproduction of the structure and dimensions of their body and dendrites stained intracellularly with procion yellow. Synaptic inputs were simulated by short-acting shunts activated at different points of the membrane. The way in which the amplitudinal and temporal course of the artificial EPSPs and their interaction and sensitivity to a polarizing current depended on the spatial localization of the corresponding inputs was investigated, revealing a correlation between the properties of the EPSP and the localization of its generator. Properties of the synaptic inputs were found to depend not only on their distance from the soma, but also on their arrangement on particular branches of the dendrites. Agreement between the results obtained in experiments on the analogue model and on actual motoneurons and the correlation between the electrophysiological, morphological, and model concepts are discussed.I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 5, No. 3, pp. 289–297, May–June, 1973.