Multiple Scattering of Electromagnetic Waves by an Array of Parallel Gyrotropic Rods

We study multiple scattering of electromagnetic waves by an array of parallel gyrotropic circular rods and show that such an array can exhibit fairly unusual scattering properties and provide, under certain conditions, a giant enhancement of the scattered field. Among the scattering patterns of such an array at its resonant frequencies, the most amazing is the distribution of the total field in the form of a perfect self-similar structure of chessboard type. The scattering characteristics of the array are found to be essentially determined by the resonant properties of its gyrotropic elements and cannot be realized for arrays of nongyrotropic rods. It is expected that the results obtained can lead to a wide variety of practical applications.Comment: 5 pages, 6 figure

Indicators of Food Activity as Breeding Dairy Cattle Characteristics

The article presents the data of ethological studies on dairy cows of the Ayrshire breed of the second lactation under conditions of stall-tethered keeping in the spring. Animals with increased nutritional activity have milk yield per 305 days of lactation higher by 1662 kg (P> 0.999) compared with animals with reduced nutritional activity. The amount of milk fat in animals with increased food activity is 72.8 kg more (P> 0.999), and the total amount of milk protein is 47.8 kg more (P> 0.999) than in animals with reduced food activity. An increased index of food activity characterizes Ayrshire cows. Comparison of milk yields obtained from Ayrshire cows with milk yields of cows with reduced food activity leads to the establishment of the following results: there is a difference in milk yield for the first lactation of 1179 kg (P> 0.999), a difference in the amount of milk fat 53.2 kg (P> 0.99), and by the amount of milk protein – 36.4 kg (P> 0.99). Comparison of the total activity index led to the following results: the difference in milk yield per 305 days of lactation is 1386 kg (P> 0.999), in the amount of milk fat 61.3 kg (P> 0.999), milk protein 40.0 kg (P> 0.999). The highest correlation is observed between the index of food activity and milk productivity in ultra-active animals. In infra-passive cows, the correlation between the index of food activity and milk productivity is negative. Therefore, an effective means of increasing milk productivity is the selection of animals of Ayrshire breed by ethological individuality, taking into account indices of food, motor, and general activity. The studied indices of ethological activity are inherited by cows and can be effectively used in breeding and breeding with highly productive cattle of the Vologda selection

Lactic-Acid Bacteria Supplement Fermented Dairy Products with Human Behavior-Modifying Neuroactive Compounds

Using high performance liquid chromatography, we established that probiotic Lactobacillus strains (Lactobacillus helveticus 100ash, L. helveticus NK-1, L. casei K3III24, and L. delbrueckii subsp. bulgaricus) grown on two milk-containing nutrient media produce important neuromediators such as biogenic amines, their precursors and deamination products, as well as neuroactive amino acids. The concentrations of biogenic amines (such as catecholamines and, with L. helveticus 100ash, also serotonin) equal or exceed those contained in the bloodstream of healthy adult humans, whereas those of most amino acids are comparatively low, except for gamma-aminobutyric acid (GABA). Of paramount importance is the fact that the bacterial cultures can release micromolar amounts of GABA and L-3,4-dihydroxyphenylalanine (DOPA)into the milk-containing media. It is known that DOPA passes through the gut-blood and the blood-brain barrier and converts into major neurotransmitters (dopamine and norepinephrine) that influence important aspects of human behavior. The data obtained suggest that dairy products fermented by live lactobacilli-containing starters are potential sources of human behavior-modifying substances

Electrostatic charge-charge and dipole-dipole interactions near the surface of a medium with screening non-locality (Review Article)

Interaction energy between two point charges, WQQ′ , or two point dipoles, WPP′ , located in a medium with a constant dielectric permittivity near the plane surface of a metallic or semiconducting substrate with the spatial dispersion of its dielectric function has been revisited. The calculations were made on the basis of the Green's function method for layered systems. Long-range lateral asymptotics were found. The non-local character of screening in the substrates was shown to substantially modify the dependences of WQQ′ and WPP′ on the distance between the objects concerned. Thus, the purported conventional electrostatic interactions between adsorbed atoms and molecules (modeled by point charges and point dipoles) should be reconsidered making allowance for the substrate polarization. In particular, this factor may significantly influence the structure of electrostatic dipole lattices arising near the surfaces of solids, as well as the kinetics of charge or dipole motion over the surface