Morphology of the spectral resonance structure of the electromagnetic background noise in the range of 0.1?4 Hz at <i>L</I> = 5.2

International audienceContinuous observations of fluctuations of the geomagnetic field at Sodankylä Geophysical Observatory (L = 5.2) were used for a comprehensive morphological study of the spectral resonance structure (SRS) seen in the background electromagnetic noise in the frequency range of 0.1?4.0 Hz. It is shown that the occurrence rate of SRS is higher in the nighttime than in the daytime. The occurrence rate is higher in winter than in summer. The SRS frequencies and the difference between neighbouring eigenfrequencies (the frequency scale) increase towards nighttime and decrease towards daytime. Both frequency scale and occurrence rate exhibit a clear tendency to decrease from minimum to maximum of the solar activity cycle. It is found that the occurrence rate of SRS decreases when geomagnetic activity increases. The SRS is believed to be a consequence of a resonator for Alfvén waves, which is suggested to exist in the upper ionosphere. According to the theory of the ionospheric Alfvén resonator (IAR), characteristics of SRS crucially depend on electron density in the F-layer maximum, as well as on the altitudinal scale of the density decay above the maximum.We compared the SRS morphological properties with predictions of the IAR theory. The ionospheric parameters needed for calculation were obtained from the ionosphere model (IRI-95), as well as from measurements made with the ionosonde in Sodankylä. We conclude that, indeed, the main morphological properties of SRS are explained on the basis of the IAR theory. The measured parameters of SRS can be used for improving the ionospheric models

Aggregation, Pretransitional Behavior, And Optical Properties In The Isotropic Phase Of Lyotropic Chromonic Liquid Crystals Studied In High Magnetic Fields

We report results on the high-field magneto-optical response of four aqueous, lyotropic, chromonic liquid crystal formulations in the isotropic phase. Measurements of the field-induced birefringence at temperatures above the isotropic-nematic coexistence region at high magnetic fields reveal qualitative differences in different materials; these differences can be attributed to the nature of aggregation and are discussed within the context of competing aggregation models. Extending these measurements to very high fields and large optical phase differences reveals the presence of an unexpected optical phenomenon: magnetic field-induced circular birefringence, measured in the Voigt geometry, in a system containing no molecularly chiral species. Possible origins of this effect are discussed

The role of «proteolysis-antiproteolysis» system genes in occupational COPD development.

COPD is multifactorial disease, in which hereditary predisposition and environmental factors (including work conditions) play an important role. Among the genes associated with possible predisposition to COPD development a group of genes with the expression impacting the activity of “proteolysis-antiproteolysis – MMP2, MM9, TIMP2, A2M, ELN is considered. The main group of 72 underground coal miners with COPD (mean age 53,7±5,8 years, mean work experience – 21,8±4,8 years), and control group of 79 healthy miners (mean age – 48,2±5,6 years, mean work experience – 20,2±4,5 years) were examined. Polymorphism of genes with out bronchopulmonary pathology MMP9, α2M was revealed using PCR with electroforetic detection in agarosegel. Polymorphism of genes TIMP2, MMP2, ELN was revealed using PCR with fluorescent detection (RealTime PCR). By the data of molecular-genetic research among miners with COPD of occupational etiology (main group) and miners without it (control group) there was estabkished a reliable difference for the genotypes:MMP9*СС,TIMP2*GG; MMP9*СС,MMP2*CC,TIMP2*G/G,α2M*IIe/IIe,ELN*Gly/Gly; MMP9*СС,MMP2*CТ,TIMP2*G/G,α2M*IIe/Val,ELN*Gly/Gly; MMP9*СС,MMP2*CС,TIMP2*G/G,α2M*IIe/Val,ELN*Ser/Se; MMP9*СТ,MMP2*CC,TIMP2*G/G,α2M*IIe/IIe,ELN*Gly/Ser. These genotypes are associated with resistance for COPD development in underground coal miners ofUkraine. The obtained results testify to the participation of genes encoding protein synthesis of the system "proteolysantiproteolysis": MMP2, MMP9, TIMP2, A2M, ELN in the formation of genetic predisposition and resistance to the development of COPD of professional etiology in miners, which reveals new opportunities in the prevention of this disease in workers subject to the high concentrations of coal-rock dust