Effect of ambient temperature increase on intestinal mucosa amylolytic activity in freshwater fish

The relationship between the level of the intestinal mucosa amylolytic activity (AA) of juvenile goldfish Carassius auratus, carp Cyprinus carpio, roach Rutilus rutilus and perch Perca fluviatilis and the rate of water temperature increase was studied. Increase in water heating rate significantly influences AA and the level of upper lethal temperatures defined by critical thermal maximum (CTM) during different seasons. At a low rate of water temperature increase, 0.04 °C/h, AA and the level of CTM are maximal during all seasons. More rapid rates of heating, 4–50 °C/h, increase the AA during the summer and usually decrease it by 2- to 7.5-fold during other seasons. Rapid increase in ambient temperature in the autumn–winter period, unnatural for seasonal dynamics, produces a negative impact upon the fish’s carbohydrate hydrolysis rate and thermal resistance.     

Biological activity of peptide extracts of medicinal plants against phytopathogenic fungi and oomycetes

The biological activity of eight peptide extracts of medicinal plants is tested under laboratory conditions with the use of a number of test systems to determine their ability to inhibit growth and development of a number of phytopathogenic fungi and oomycetes. A multicomponent extract consisting of individual extracts of field horsetail, elecampane, and greater celandine is the most effective.     

Use of nitroxide spin probes and electron paramagnetic resonance for assessing reducing power of beer. role of SH groups

Intensity of EPR spectra of stable organic free radicals, nitroxides, is decreasing with time if the radicals are dissolved in beer. The process is determined by a chemical reaction of nitroxide reduction by components naturally present in beer. Kinetics can be described as a simple irreversible first order with respect to both nitroxide and one reducing agent. Effective concentration of the reducing agent and the corresponding reaction rate constant has been determined. It is demonstrated that the nitroxide reduction is sensitive to the presence of solvent-accessible SH groups of proteins present in beer. It is proposed that quantitative analysis of reduction kinetics of small water-soluble nitroxide radicals such as TEMPO and TEMPOL can be used to assess the reducing power of beer. The effect of accelerated aging of beer achieved at elevated temperatures on nitroxide reduction kinetics is demonstrated.     

Transformation of unsymmetrical dimethylhydrazine in soils

The transformation of unsymmetrical dimethylhydrazine (UDMH, a propellant component) applied at a rate of 240 g/kg to different soils was studied. The kinetic regularities of a decrease in the UDMH concentration and the accumulation of its transformation products leached out from dry and wet soils were investigated 3, 10, 30, and 90 days after its application. As the UDMH enters the soil, it vaporizes, and the elevated moisture of the soils promotes an increase in the pollutant’s concentration at the initial moment; then, the concentration differences become leveled to the end of observation. It was also shown that the higher the organic matter content in the soil, the higher the UDMH concentration. However, at the end of the observations, on the 90th day, the total UDMH concentration did not exceed 0.5% of its initial content. In order to explain the UDMH behavior in the soils, one should take into account the existence of different forms of this substance and the changes in their ratios with time. The main portion of UDMH retained by the soil in the free form is transformed during the first few days. The products of the UDMH transformation, such as 1-methyl-1,2,4-triazole, formic acid dimethylhydrazide, dimethylguanidine, and dimethylamine are formed in considerable amounts, and their concentrations should be controlled in places of UDMH spills on soils.     

The methods of geomorphometry and digital soil mapping for assessing spatial variability in the properties of agrogray soils on a slope

The relationships between the morphometric parameters (MPs) of topography calculated on the basis of digital elevation model (АSTER GDEM, 30 m) and the properties of the plow layer of agrogray soils on a slope were analyzed. The contribution of MPs to the spatial variability of the soil moisture reached 42%; to the content of physical clay (<0.01 mm particles), 59%; to the humus content, 46%; to the total nitrogen content, 31%; to the content of nitrate nitrogen, 28%; to the content of mobile phosphorus, 40%; to the content of exchangeable potassium, 45%; to the content of exchangeable calcium, 67%; to the content of exchangeable magnesium, 40%; and to the soil pH, 42%. A comparative analysis of the plow layer within the eluvial and transitional parts of the slope was performed with the use of geomorphometric methods and digital soil mapping. The regression analysis showed statistically significant correlations between the properties of the plow layer and the MPs describing surface runoff, geometric forms of surface, and the soil temperature regime.     

Changes in the Soil Cover under the Impact of Short-Term Climate Fluctuations

Eurasian Soil Science - The climate of the 1950s–1990s in the center of the Russian Plain was characterized by the alternation of cool–wet and warm–dry periods, which is confirmed...