12 research outputs found
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
Whistler wave radiation from a pulsed loop antenna located in a cylindrical duct with enhanced plasma density
Whistler wave radiation from a pulsed loop antenna located in a cylindrical duct with enhanced plasma density
Whistler wave radiation from a pulsed loop antenna located in a cylindrical duct with enhanced plasma density
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