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Discussed are the possibilities of using syntaxa from floristic classification for the analysis of secondary restorative successions after forest cutting in South Ural Region. Peculiarities of secondary forest communities classification that may be viewed as subjects of indigenous vegetation syntaxa forming, sub-associations or could be systematized according to 'deductive' classification introduced by K. Kopecky and S. Heiny are considered. An example is presented of an analysis of communities succession system formed after cutting down hemiboreal pine and birch-pine herbaceous forests of Bupleuro-Pinetum association. Within this system the processes of divergence and convergence of succession series take place. Divergence occur as a result of lifting of the influence caused by dominants edificating role and manifestation of differences in soil humidification, also as a consequence of soil enrichment by mineral elements after burning down the felling debris. The reason behind convergence is grading influence of renewed forest stand. Trends in species richness changes during restorative successions may differ depending on ecotope features. In course of a succession, models of tolerance and inhibition become apparent.

There was analyzed the influence of warmth, moisture, and soil fertility on species richness and phytosociological spectrum of phytocenoses of three classes of Southern Ural autochthonous forests: Querco-Fagetea (nemoraloher-bosa), Vaccinio-Peceetea (boreal forests), and Brachypodio-Betuletea (hemiboreal forests). Environmental factors were estimated by Landolt's scales. We studied the changes of syntaxa of association rank by means of gradient phy-tosociological analysis. In phytosociological specter, in addition to the cenoflora of the three investigated classes, we estimated the representation of species from steppes (class Festuco-Brometea), xerothermal forest edges (class Tri-folio-Geranietea), and meadows (class Molinio-Arrhenatheretea). For boreal and hemiboreal forests, the dependence of cenoses species richness on environmental factors is parabolic, with its maximum in the middle of the gradient. With respect to nemoral forests, species richness declines with increase of environmental factors values. Maximum species richness is registered when the proportion of species of the own cenosis class in the community is maximal. The contribution of the ecotone effect (inclusion of other classes' species in the community composition) enhances as species richness reduces.

There was studied the traumatic disease course in 11 pregnant women with different variants of severe combined thoracic and abdominal trauma, constituting 1.6% of total number of injured persons, suffering polytrauma. Polytrauma have had caused severe course of traumatic disease in majority of pregnant women. In the early postshock period the complications had occurred in 90.9% of injured persons. Antenatal death of fetus was noted in 81.8% of pregnant women with polytrauma. All pregnant women after polytrauma are alive.

Eco-floristic classification (Brawn-Blanquet system) is useful since in similar manner it can establish ecological units of different level (syntaxons) that have high indicative value. Syntaxons can be used as markers of terrestrial ecosystems of different range. Although this system was proposed by analogy with plant taxonomy it reflects vegetation continuum. The application of this approach is based on certain standards and supported by developed software. The elements of arbitrariness in Brawn-Blanquet method are constrained by rules of strict recommendations. The method is considered as necessary in studies of biodiversity in protected areas.

Non-infectious virus particles produced by influenza virus (classical fowl plague)-infected Ehrlich ascitic carcinoma cells have the same morphology, size and sedimentation rate as the standard virions. Their main difference from the allantoic virus is their extreme fragility. They remain intact upon a short-term centrifugation in sucrose solutions but desintegrate upon prolonged centrifugation. In isopicnic fractionation they are detected in two forms, with a density of 1.23 g/ml retaining the hemagglutinating but not the neuraminidase activity and with a density of 1.27 g/ml deprived of both hemagglutinating and neuraminidase activity. In the electron microscopic examination the 1.23 g/ml structure appears as virus particles with defective areas in the surface spikes layer whereas the 1.27 g/ml structure has no spike layer at all. The protein analysis by polyacryl amide gel electrophoresis revealed a sharply reduced amount of the membrane protein in the ascitic virus. A hypothesis is suggested according to which the reduced amount of the membrane protein is the cause of the unusual fragility of ascitic virus particle membranes as a result of which they readily lose glycoproteins which, in its turn, leads to their reduced infectious activity.

Noninfectious virus particles were produced in Ehrlich ascites tumor cells infected intraperitoneally with fowl plague virus. The PFU yield of virus per cell was less than 0.1 and the ratio PFU/HA units in the progeny virus was less than 10(3). The virus particles had the same morphology and size as egg-grown virus but were more fragile. They were disrupted by centrifugation through sucrose and caesium chloride gradients, but this disruption was avoided by fixing the particles with formaldehyde before centrifugation. Analysis of polypeptides by SDS-PAGE showed that ascites-grown virus particles contained reduced amounts of matrix protein compared with egg-grown virus.

The properties of fowl plague virus (Influenzavirus A) nucleocapsids isolated from the cytoplasm of infected Ehrlich ascites carcinoma cells and chick embryo cells were compared. Nucleocapsids isolated from both systems possessed similar polypeptides (P and NP) but differed in their biophysical characteristics. Nucleocapsids from ascites cells sedimented in velocity sucrose gradients slower (from 25 to 50 S) and the majority of them banded at higher density in CsCl gradients (rho 1.38 as compared to 1.34 g/ml) than nucleocapsids from chick embryo cells. In the electron microscope they appeared as thin threads 3--4 nm in diameter.