Oval of Aurorae Borealis and the Ring Current in the Earth's Magnetosphere

Oval of aurora borealis and ring current in earth magnetospher

Magnetic Field in the Tail of the Magnetosphere and Its Dimensions

Index of magnetic activity and variations of geomagnetic dimensions of magnetosphere tai

Distributivity breaking and macroscopic quantum games

Examples of games between two partners with mixed strategies, calculated by the use of the probability amplitude as some vector in Hilbert space are given. The games are macroscopic, no microscopic quantum agent is supposed. The reason for the use of the quantum formalism is in breaking of the distributivity property for the lattice of yes-no questions arising due to the special rules of games. The rules of the games suppose two parts: the preparation and measurement. In the first part due to use of the quantum logical orthocomplemented non-distributive lattice the partners freely choose the wave functions as descriptions of their strategies. The second part consists of classical games described by Boolean sublattices of the initial non-Boolean lattice with same strategies which were chosen in the first part. Examples of games for spin one half are given. New Nash equilibria are found for some cases. Heisenberg uncertainty relations without the Planck constant are written for the "spin one half game"

Cyclosporin A-insensitive permeability transition in brain mitochondria - Inhibition by 2-aminoethoxydiphenyl borate

The mitochondrial permeability transition pore (PTP) may operate as a physiological Ca 2 � release mechanism and also contribute to mitochondrial deenergization and release of proapoptotic proteins after pathological stress, e.g. ischemia/reperfusion. Brain mitochondria ex- hibit unique PTP characteristics, including relative re- sistance to inhibition by cyclosporin A. In this study, we report that 2-aminoethoxydiphenyl borate blocks Ca 2 � - induced Ca 2 � release in isolated, non-synaptosomal rat brain mitochondria in the presence of physiological con- centrations of ATP and Mg 2 � .Ca 2 � release was not me - diated by the mitochondrial Na � /Ca 2 � exchanger or by reversal of the uniporter responsible for energy-depend- ent Ca 2 � uptake. Loss of mitochondrial Ca 2 � was accom - panied by release of cytochrome c and pyridine nucleo- tides, indicating an increase in permeability of both the inner and outer mitochondrial membranes. Under these conditions, Ca 2 � -induced opening of the PTP was not blocked by cyclosporin A, antioxidants, or inhibitors of phospholipase A 2 or nitric-oxide synthase but was abol - ished by pretreatment with bongkrekic acid. These find- ings indicate that in the presence of adenine nucleotides and Mg 2 � ,Ca 2 � -induced PTP in non-synaptosomal brain mitochondria exhibits a unique pattern of sensitivity to inhibitors and is particularly responsive to 2-amino- ethoxydiphenyl borate

World first complex optical instrumental observations of aurora in the Arctic in 1899?1900

International audienceThis report presents data and analysis of visual, photographic and auroral spectral data, obtained by the Russian astronomer J. Sykora from the Russian-Swedish expedition to Spitsbergen during the 1899?1900 winter season, which are historically significant for auroral studies. These data seem to be the first instrumental observations of auroral spectra in the Arctic and some of the emissions discovered have world priority. The second known photos in the world of aurora from the Arctic and undoubtedly the first ones for geomagnetic latitudes of about 75° in the Spitsbergen Archipelago were obtained. The results of the expedition are discussed from a modern point of view and compared with our knowledge of the 21st century. A description of the equipment and methods that were used by Russian astronomers is presented. Both photographic and spectral devices using registration by photographic plates were used, along with special methods of their development and enhancement. Some statistical analysis was done on the basis of the expedition reports and diaries. This analysis shows that by using Sykora's data it was possible to discover the auroral oval or instantaneous auroral distribution over the polar region. Analysis of photographic samples and sketches of the aurora demonstrate typical auroral form outlines as they are described today. Spectral plates exposed for several hours to auroral lights revealed not only the main auroral emissions, which were well-known at that time, but several other unidentified weak emissions, which were rediscovered and interpreted years later. Keywords. History of geophysics (Atmospheric sciences, instruments and techniques

A substorm in midnight auroral precipitation

International audienceDMSP F7 spacecraft observations for the whole of 1986 were used to construct the empirical model of the midnight auroral precipitation during a substorm. The model includes the dynamics of different auroral precipitation boundaries and simultaneous changes in average electron precipitation energy and energy flux in different precipitation regions during all substorm phases, as well as the IMF and solar wind plasma signatures during a substorm. The analysis of the model shows a few important features of precipitation. (1) During the magnetic quietness and just before the beginning of the substorm expansive phase the latitudinal width of the auroral precipitation in the nightside sector is about 5 ? 6° CGL, while that of the auroral oval is about 2 ? 3° CGL during such periods. (2) For about 5 min before the substorm onset a decrease in the average precipitating electron energy in the equatorward part of auroral zone was observed simultaneously, with an increase in both the average electron energy and energy flux of electron precipitation in the poleward part of the auroral zone. (3) The isotropy boundary position in the beginning of the substorm expansive phase coincides well with the inner edge of the central plasma sheet. The analysis of interplanetary medium parameters shows that, on average, during the substorm development, the solar wind dynamic pressure was about 1.5 times that of the magnetic quietness period. Substorms occurred predominantly during the southward IMF orientation, suggesting that substorm onset often was not associated with the northern turn or decrease in the southward interplanetary Bz . The Northern Hemisphere's substorms occurred generally during the positive interplanetary By in winter, and they were observed when the interplanetary By was negative in summer

On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt

International audienceObservations and modelling are presented which illustrate the ability of the Finland CUTLASS HF radar to monitor the afternoon-evening equatorward auroral boundary during weak geomagnetic activity. The subsequent substorm growth phase development was also observed in the late evening sector as a natural continuation of the preceding auroral oval dynamics. Over an 8 h period the CUTLASS Finland radar observed a narrow (in range) and persistent region of auroral F- and (later) E-layer echoes which gradually moved equatorward, consistent with the auroral oval diurnal rotation. This echo region corresponds to the subvisual equatorward edge of the diffuse luminosity belt (SEEL) and the ionospheric footprint of the inner boundary of the electron plasma sheet. The capability of the Finland CUTLASS radar to monitor the E-layer SEEL-echoes is a consequence of the nearly zero E-layer rectilinear aspect angles in a region 5?10° poleward of the radar site. The F-layer echoes are probably the boundary blob echoes. The UHF EISCAT radar was in operation and observed a similar subvisual auroral arc and an F-layer electron density enhancement when it appeared in its antenna beam.Key words: Ionsophere (ionospheric irregularities) · Magnetospheric physics (auroral phenomena; magnetosphere?ionosphere interactions

Spatial variations of ionospheric conductivity and radar auroral amplitude in the eastward electrojet region during pre-substorm conditions

The dependence of auroral backscatter amplitude on different ionospheric parameters (conductivity, current density, electric field) is studied by means of data recorded by STARE (Scandinavian Twin Auroral Radar Experiment), the two-dimensional Scandinavian Magnetometer Array (SMA), and auroral all-sky cameras. The observations were made on 16 March 1978 during pre-substorm conditions in the region of the eastward polar electrojet. The paper shows that in this event the auroral backscatter amplitudes in the 140 MHz frequency band were controlled mainly by spatial variations in the electron density or conductivity inside the back-scatter volume. To a certain extent also a linear relationship between backscatter amplitude and ionospheric current density was found but it is regarded as a special case of a more general relationship between electron density and backscatter amplitude. A stable discontinuity in the Hall conductivity over the most equatorward auroral arc was deduced from the data: On the equatorward side the conductivity was 3-5 times higher than on the nearby poleward side. Our conclusions are discussed in the light of some previously published results on the same subject.           ARK: https://n2t.net/ark:/88439/y000016 Permalink: https://geophysicsjournal.com/article/262 &nbsp

Mitochondrial alpha-ketoglutarate dehydrogenase complex generates reactive oxygen species

Mitochondria-produced reactive oxygen species (ROS) are thought to contribute to cell death caused by a multitude of pathological conditions. The molecular sites of mitochondrial ROS production are not well established but are generally thought to be located in complex I and complex III of the electron transport chain. We measured H 2 O 2 production, respiration, and NADPH reduction level in rat brain mitochondria oxidizing a variety of respiratory substrates. Under conditions of maximum respiration induced with either ADP or carbonyl cyanide p -trifluoromethoxyphenylhydrazone, � -ketoglutarate supported the highest rate of H 2 O 2 production. In the absence of ADP or in the presence of rotenone, H 2 O 2 production rates correlated with the reduction level of mitochondrial NADPH with various substrates, with the exception of � -ketoglutarate. Isolated mitochondrial � -ketoglutarate dehydrogenase (KGDHC) and pyruvate dehy- drogenase (PDHC) complexes produced superoxide and H 2 O 2 . NAD � inhibited ROS production by the isolated enzymes and by perme- abilized mitochondria. We also measured H 2 O 2 production by brain mitochondria isolated from heterozygous knock-out mice deficient in dihydrolipoyl dehydrogenase (Dld). Although this enzyme is a part of both KGDHC and PDHC, there was greater impairment of KGDHC activity in Dld-deficient mitochondria. These mitochondria also produced significantly less H 2 O 2 than mitochondria isolated from their littermate wild-type mice. The data strongly indicate that KGDHC is a primary site of ROS production in normally functioning mitochondria

Theoretical aspects of it consulting: problems and prospects

This article discusses the theoretical aspects of IT consulting - its problems and prospects. Today it is difficult to imagine a really successful business, which would not have resorted to consulting services. IT consulting helps to solve most of the problems that arise during the conduct of business. The article gives the definition, historical background, see the formation of consulting in Russia and abroadВ данной статье рассматриваются теоретические аспекты ИТ - консалтинга - его проблемы и перспективы. На сегодняшний день трудно представить себе по-настоящему успешный бизнес, который бы не прибегал к услугам консалтинга. ИТ - консалтинг помогает решить большинство проблем, которые возникают во время ведения бизнеса. В статье даны определения, приведена историческая справка становления консалтинга в России и за рубежо