Conventional acute myocardial infarction (AMI) diagnosis is quite accurate and has proved its effectiveness. However, despite this, discovering more operative methods of this disease detection is underway. From this point of view, the application of exhaled air analysis for a similar diagnosis is valuable. The aim of the paper is to research effective machine learning algorithms for the predictive model for AMI diagnosis constructing, using exhaled air spectral data. The target group included 30 patients with primary myocardial infarction. The control group included 42 healthy volunteers. The ‘LaserBreeze’ laser gas analyzer (Special Technologies Ltd, Russia), based on the dual-channel resonant photoacoustic detector cell and optical parametric oscillator as the laser source, had been used. The pattern recognition approach was applied in the same manner for the set of extracted concentrations of AMI volatile markers and the set of absorption coefficients in a most informative spectral range 2.900 ± 0.125 µm. The created predictive model based on the set of absorption coefficients provided 0.86 of the mean values of both the sensitivity and specificity when linear support vector machine (SVM) combined with principal component analysis was used. The created predictive model based on using six volatile AMI markers (C5H12, N2O, NO2, C2H4, CO, CO2) provided 0.82 and 0.93 of the mean values of the sensitivity and specificity, respectively, when linear SVM was used.

Rapeseed has a multifunctional agricultural and environmental value. According to statistics, the growth of acreage occupied by rapeseed in the Russian Federation for 10 years reached 126.8 % or 872.9 thousand ha. The article provides an assessment of spring rapeseed production for oilseeds in the Clearfield system at different levels of mineral nutrition in combination with Ecorost bio-fertilizer in conditions of the Non-Chernozem Zone of Russia. The studies were carried out in 2018–2019 at an experimental agrotechnological station of Ryazan State Agrotechnological University Named after P.A. Kostychev (FSBEI HE RSATU) on gray forest soils. High efficiency of the Clearfield production system has been established. The introduction of N180P120K60 complex for pre-sowing cultivation contributed to the formation of maximum indicators of the rapeseed yield formula and size. The highest yields were shown by Ecorost variants: Kultus KL N180P120K60 (27.8 dt/ha), Cultus KL N180 (27.3 dt/ha), Cebra KL N180P120K60, N180 (24.4 dt/ha), Cyclus KL N180, N90P60K60 (26.6 dt/ha). The maximum profitability of rapeseed oilseeds production was obtained on N180 variant Kultus KL (133.5 %).

To understand all the structural complexity of soil fertility, one can use the principal component analysis of factor analysis. Factor analysis, with all its shortcomings to identify structural relationships between variables, can be used to understand the complexity of soil fertility, by some assumptions. It can be estimated through bonitet. The work was carried out on the basis of materials from an agrochemical survey of agro-gray soils. Exchangeable acidity, mobile forms of phosphorus and potassium, humus, the sum of exchangeable bases and bonitet calculated in accordance with them were analyzed. The sample number was 68. Group 0 included bonitet with values less than 90 units and group 1 had bonitet with values more than 90 units. It was found that the contribution of exchangeable acidity and phosphorus to the first main component, which accounted for about 39% of the total dispersion, was maximum and equal to 0.7 and 0.84 units, respectively. Humus and potassium were positively associated with the second component (29% of dispersion) and their contribution was 0.7 and 0.81 units, respectively.

The mineralogical composition of clay loamy agro-gray soil and the content of nutrient elements in the soil and its fractions were determined. This allowed estimating the nutrient supply and natural productivity of the soil. The long-term use of soils with the application of mineral and organic fertilizers affected the soil mineralogy: both aggradation and degradation processes were observed. The fertilizing system recommended for application to the agro-gray soil did not affect the crystal-chemical parameters of soil minerals. However, soil acidification and changes in the humus fractional composition towards increasing the content of fulvic acids show intensive degradation of soil minerals, which can lead to adverse consequences for soil fertility.