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It was shown that tobacco leaf treatment with 100 mM H₂0₂ increased their content ofendogenous H₂0₂ and activities of catalase and hydrolases (acid phosphatase, proteases, and RNase) and also caused'various chang- es in the cell structure. In this case, programmed cell death (PCD) occurred in some cells, which was ob- served as chromatin condensation, cytoplasm collapse, etc. In the meantime, many cells displayed organelle activation rather than PCD. It is suggested that cells that undergo H₂0₂-dependent PCD release signaling molecules inducing protective mechanisms against oxidative stress in neighboring cells not exhibiting PCD.
Strategies for conservation of endangered amphibian and reptile species are discussed. One-fifth of all vertebrates belongs to the category of "endangered species," and amphibians are first on the list (41%). Every fifth reptile species is in danger of extinction, and insufficient information is characteristic of every other fifth. As has been demonstrated, efficient development of a network of nature conservation areas, cryopreservation, and methods for laboratory breeding and reintroduction play.the key roles in adequate strategies for preservation of amphibians and reptiles.
The lipid composition and content were analyzed in lettuce Lactica sativa L. (variety Stone head) leaves grown in a weak horizontal permanent magnetic field (PMF) produced by Helmholtz coils of 400 A/m strength under controlled conditions of illumination and temperature in phytothrone. Control plants were grown under the same conditions in a geomagnetic field. PMF decreased the total lipid content by 40% due to a significant decrease in polar and neutral lipids. Among polar lipids, the fractions of glycolipids and phospholipids diminished. Among glycolipids, the content of monogalactosyldiacylglycerols was lower by 25-52%. The content of phospholipids decreased, too, namely phosphatidylglycerols were lower by 17-51%, phosphatidylcholines by 21-24%, phosphatidylethanolamines by 12-20%, and phosphatidylinositols by 12-41%. Therefore, weak PMF reduced the content of lipids in membranes, including the chloroplast, mitochondrial, and cytoplasmic membranes.
Emission of methane from the grass-moss fens of the Western Siberia subtaiga was studied using a static chamber method. It was established that a median half of the interquartile range of the specific flow of CH4 in the studied wetland ecosystems constituted 4.9 ± 2.9 mg of CH4/(m2 x h). It was shown that such a high spatial variability of emission is caused mainly by the difference in the level of fen waters. It was found that, in these observations, a higher level of the water stand correlates with lower emission values. The causes of this phenomenon are discussed, and recommendations for conducting field studies for estimating the regional flow are given.
The orosensory food testing behavior in fish was studied using the nine-spined stickleback Pungitiuspungitius as an example. The patterns of the chronology of manipulations performed by fish in testing food objects were identified. The existence of two stereotypical patterns of feeding behavior was confirmed, and their new characteristics were obtained. The relationship between the responsiveness to food and the predisposition of fish to feeding was revealed.
It is revealed that the larval brain of Pterostichus niger, an active predator with well-developed long-distance sense organs (the set of antennal sensilla and lateral ocelli, or stemmata) at hatching already contains optic lobes, which include two groups of optic neuropils and complex antennal lobes of glomerular neuropil. It is shown that the central complex of the protocerebrum is represented by a bipartite protocerebral bridge and the upper part of the central body and the mushroom bodies include, numerous Kenyon cells, a well-developed calyx, a peduncular apparatus, and numerous neuroblasts.
The effects of Elateridae larvae (wireworms) on the structure, functional diversity, and tolerance of the soil microbial population in steppe ecosystems have been investigated. The trophic and locomotor activity of wireworms leads to an appreciable increase in bacterial abundance and suppression of fungal activity. The fungal hyphae in the presence of wireworms are significantly damaged, which can be related to the feeding activity of Elateridae. The increase of bacterial abundance on the background of exclusion of the fungal component shifts the microbial succession to the acceleration of organic matter mineralization. The microbial consumption of mono- and oligosaccharides, alcohols, and water-soluble compounds increases in the presence of wireworms (multisubstrate test). The effect of Elateridae larvae on the microorganisms transforming nitrogen compounds is species-specific. Agriotes obscurus activity decreases their consumption of urea and creatinine by 2.1-2.5 times, and Selatosomus aeneus increases it by 1.3 and 2.5 times, respectively. The intensity of actual nitrogen fixation in the soil increases in the presence of wireworms by almost 4 times, but the losses of gaseous nitrogen do not increase because of the decrease in both the denitrification and methanogenesis rates
The external morphological and internal histological features of morphogenic structures (embryoids, calli with embryoids, and calli with buds and roots) have been studied in vitro in a wheat anther culture by light microscopy. The results of this study have been compared with data obtained earlier by scanning electron microscopy.
Glochidia of three freshwater anodontine bivalves: Kunashiria Starobogatov in Zatrawkin, 1983, Sinanodonta Modell, 1944, from the Far East, and Anodonta Lamarck, 1799, were investigated by scanning electron microscopy. Data on the microsculpture of the outer surface of glochidial valves are given. Among the three genera discussed, the glochidia of Anodonta are the largest, with a loose-looped outer microsculpture and numerous granules. The glochidia of Kunashiria and Sinanodonta differ by the valve height--length proportions and some details of the outer microsculpture: glochidia of Kunashiria have a tight-looped outer sculpture while the glochidia of Sinanodonta have a loose-net outer sculpture.
We have studied the distribution of plant fibers of different sizes in the digestive tracts of two hare species: the brown hare (Lepus euopaeus) and the mountain hare (L. timidus). In all studied hares (18 specimens), the highest amount of fine-sized fibers (less than 0.25 mm length) was observed in the cecum (50-70% of the total fiber mass). It was found out that the fine-sized content in the digestive tract, and especially in the cecum, is provided not only by the separation mechanism of the colon, but also by coprophagy. It was shown that repeated passage of food through the digestive tract compensates small volume of the cecum and increases the period of digestion of the same portions of food.
The general patterns of the effect of cuttings on the habitat structure, abundance, territorial distribution, and specific ecological features of 11 small mammalian species are analyzed based on long-term studies (1958-2013) covering the overall area of eastern Fennoscandia. The responses to concentrated cuttings common for most of the examined species include a decrease in total population size, transition to an- arrhythmic population dynamics with drastic short-term rises and deep long depressions, formation of unstable mosaic spatial distribution, disturbances of the reproduction rates, and a decrease in reproduction intensity.
In this study, we investigate the influence of a mother on the behavior of young rabbits during the prepubertal period. It is shown that the presence ofthe mother affects the ratio of types of activity in offspring and the mother can demonstrate behavioral patterns to suppress aggressive behavior in offspring. It was found that rabbits in the prepubertal period continue to have active contact with their mother and make successful attempts at sucking. It was noted that, in terms of percentage, both in the frequency and duration of different forms of activity among rabbits from one to three months of age, a neutral socially oriented and feeding behavior appear to be predominant. There were significant differences in the frequency of the socially oriented behavior and the duration of feeding behavior in young rabbits, who grew up with their mother and without her.
Flora similarity was assessed using complete floristic lists of five ecotopes in each of four mounds along the transect from meadow steppes to desert steppes. It was found that the circumapical similitude of floras is more significant than the expositional similitude. Soil analysis in separate ecotopes showed that regular changes in the biogeochemical features are manifested along the topographic gradient and under the effect of the insolation exposure of slopes in local (mound) ecosystems. It was noted that the slopes are characterized by the most abundant steppe vegetation classes in the phytosociological spectrum of mound ecotopes.
Primary plant successions on volcanic deposits of the Tolbachinskii DoI Plateau (Central Kamchatka) were studied. The main factors determining the succession rate were revealed. The peculiarities of plant successions on lava flows and ash-scoria deposits differed significantly. Some common mechanisms for all volcanic regions of the world were revealed. The leading factors of plant succession on lava flows were the type of lava surface, the texture of lava, and the fine tephra accumulation rate. The main factors determining plant succession on ash-scoria deposits were wind and water erosion and the distance to the seed sources. The time of formation of a secondary permanent larch (Larix cajanderi Mayr.) forest should take about 1500-2000 years on lava flows and up to 1000 years (but not less than 300-500 years) on ash-scoria plains.
The distribution patterns of the common arctic zooplankton species Oithona similis and Oithona atlantica were investigated in the Barents Sea during warm and temperate years. The maximum abundance and biomass of Oithona spp. (159 x 10(3) ind./m2 and 38.8 mgC/m2, respectively) were recorded in the waters of Atlantic origin. O. atlantica occurred in Arctic waters only during anomalously warm years. It has been found that the quantitative characteristics of O. similis were negatively correlated with salinity and the winter NAO index, whereas the abundance of O. atlantica in Atlantic waters was positively correlated with the temperature anomaly. It is found that the abundance and biomass of Oithona pp. were comparable with the values recorded in other Arctic regions.
An assessment is given for the contemporary state of zooplankton community in the waters of the upper reaches of the Kenti River system under the conditions of long-term potash-sulfate industrial pollution. This article presents a number of structural indicators of the zooplankton community that show simplification in the structure of species diversity and its reduction, as well as the disappearance of a number of systematic groups. It is noted that the number of zooplankton taxa increases with distance from the source of pollution (Kostomukshskoe and Kento lakes), and the average quantitative indicators also increase in this case. A comparison with the results that were previously obtained for the reservoirs of the studied environment has been carried out.
The phylogenetic position of the genera Rossithidium and Psammothidium was studied using the plastid gene rbcL. The genus Rossithidium is not an independent taxon and should be transferred to Psammothidium. Taxa from Psammothidium genus formed a sister, but independent clade to taxa with Achnanthidium. Our data has shown that the order Achnathales was not the natural taxon and should be reduced, but the three families included in it were natural. Genera like Psammothidium (including Rossithidium) and Lemnicola should be included into the family Achnanthidiaceae. Therefore, raphe does not play an important role in diatom taxonomy and its loss occurred many times during the evolution of diatoms.
The activity and spectrum of proteinases in the intestines of host fishes change upon infestation with cestodes. Serine proteinases are found to make a greater contribution to the total proteolytic activity. The reduction of proteolytic activity is associated with adsorption of the enzymes of the host on the surface of cestodes, and the increase in the activity is caused by the injury of the intestinal mucosa by the attachment apparatuses of cestodes. The inhibition of proteainase activity indicates the possible participation of microbiota enzymes in protein hydrolyses.
A comparative study of yellow-anthered and red-anthered forms of Scots pine, growing in hydrothermally contrasting bog and upland ecotopes, was performed by karyological traits and nuclear DNA content. Some differences were revealed between yellow-anthered and red-anthered forms of pine as components of intraspecific diversity in'the frequency of occurrence of violations in the number of chromosomes, chromosome sizes (total length of diploid set, absolute and relative lengths), the centromeric index, the localization of secondary constrictions in chromosomes, and the amount of DNA.
It was shown previously that the Mongolian hamster (Allocricetulus curtatus) is a mammalian species with irregular short hibernation. The purpose of the present study was to determine how this status affects seasonal changes in the biochemical and hematological parameters in A. curtatus males under a natural temperature and light regime. It was found that a reduction in circulating white blood cells, specifically lymphocytes, neutrophils, eosinophils, basophils, and monocytes, occurred in-winter. and bilirubin levels increased in spring. These characteristics make Mongolian hamsters closer to the true hibernating species. At the same time, the character of seasonal changes in the number of red blood cells, glucose, total protein, creatinine, and albumin is closer to species with torpor.