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Dependence of the sound-signal frequency on the animal body length was studied in 14 ground squirrel species (genus Spermophilus) of Eurasia. Regression analysis of the total sample yielded a low determination coefficient (R2 = 26%), because the total sample proved to be heterogeneous in terms of signal frequency within the dimension classes of animals. When the total sample was divided into two groups according to signal frequency, two statistically significant models (regression equations) were obtained in which signal frequency depended on the body size at high determination coefficients (R2 = 73 and 94% versus 26% for the total sample). Thus, the problem of correlation between animal body size and the frequency of their vocal signals does not have a unique solution.

A series of environmentally safe bioactive chelators based on racemic aspartic and glutamic acids have been obtained. In addition, an optically active L-isomer of N-(carboxymethyl) aspartic acid (L-CMA) was synthesized, and its acid-base characteristics were determined by pH-titration analysis. The detected high activity of the nitrogen atom of L-CMA (pK4 = 10.42) is apparently due to the betainic structure of this compound in solution and formation of a cycle with an intramolecular hydrogen bond between the nitrogen atom of the protonated amino group and the oxygen atom of the water molecule included in this cycle. This hypothesis is confirmed by IR spectral analysis of the L-isomers of the parent acids.

The destruction of complexons derived from succinic acid under the action of UV radiation was studied. IR spectroscopy, thin-layer paper chromatography, and complexometric titration were used to determine the destruction products of these complexons. It was found that the complexons decompose under UV irradiation substantially more easily than ethylenediaminetetraacetic acid does, and the products of their decomposition can undergo a biological utilization under natural conditions. The data obtained in the study make it possible to choose, instead of ethylenediaminetetraacetic acid, ligands that will be nearly fully destructible in the light without deteriorating the ecology.

A linear control problemwith a nonsingleton initial set is dealt with. For this problem,we consider the problem of transforming this initial set along trajectories of a linear controlled system into some fixed terminal set in a finite time using a single control. Various aspects of this control problem are studied using the machinery of support functions.

The drawing of Netherlandish painter Pieter Bruegel the Elder “The Big Fish Eat the Little Fish” reflects perhaps not political allusions, as it is interpreted in the history of art, but a graphic food-chains scheme. It is possible that the picture engraving, stored in the British Museum, has influenced the creation of the food-chains concept by British ecologists Johnstone [1], Hardy [2] and Elton [3]. The taxonomic attachment of organisms depicted in the drawing has been determined.

We consider a linear control problem with a partially known initial condition. Kalman’s observability theory of linear controlled system is applied to derive constructive sufficient conditions under which the control process to attain a terminal set M can be decomposed into the following stages: first collect information on system output, then apply this information to reconstruct the system’s initial state, and finally proceed with active control to attain the terminal set M.