2,104 research outputs found

    Tropospheric forcing of the boreal polar vortex splitting in January 2003

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    e dynamical evolution of the relatively warm stratospheric winter season 2002–2003 in the Northern Hemisphere was studied and compared with the cold winter 2004–2005 based on NCEP-Reanalyses. Record low temperatures were observed in the lower and middle stratosphere over the Arctic region only at the beginning of the 2002–2003 winter. Six sudden stratospheric warming events, including the major warming event with a splitting of the polar vortex in mid-January 2003, have been identified. This led to a very high vacillation of the zonal mean circulation and a weakening of the stratospheric polar vortex over the whole winter season. An estimate of the mean chemical ozone destruction inside the polar vortex showed a total ozone loss of about 45 DU in winter 2002–2003; that is about 2.5 times smaller than in winter 2004–2005. Embedded in a winter with high wave activity, we found two subtropical Rossby wave trains in the troposphere before the major sudden stratospheric warming event in January 2003. These Rossby waves propagated north-eastwards and maintained two upper tropospheric anticyclones. At the same time, the amplification of an upward propagating planetary wave 2 in the upper troposphere and lower stratosphere was observed, which could be caused primarily by those two wave trains. Furthermore, two extratropical Rossby wave trains over the North Pacific Ocean and North America were identified a couple of days later, which contribute mainly to the vertical planetary wave activity flux just before and during the major warming event. It is shown that these different tropospheric forcing processes caused the major warming event and contributed to the splitting of the polar vortex

    Shape of primary proton spectrum in multi-TeV region from data on vertical muon flux

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    It is shown, that primary proton spectrum, reconstructed from sea-level and underground data on muon spectrum with the use of QGSJET 01, QGSJET II, NEXUS 3.97 and SIBYLL 2.1 interaction models, demonstrates not only model-dependent intensity, but also model-dependent form. For correct reproduction of muon spectrum shape primary proton flux should have non-constant power index for all considered models, except SIBYLL 2.1, with break at energies around 10-15 TeV and value of exponent before break close to that obtained in ATIC-2 experiment. To validate presence of this break understanding of inclusive spectra behavior in fragmentation region in p-air collisions should be improved, but we show, that it is impossible to do on the basis of the existing experimental data on primary nuclei, atmospheric muon and hadron fluxes.Comment: Submitted to Phys. Rev.

    Synthesis, Structure, and Magnetic Properties of an Al2O3/Ge-p/Al2O3/Co Thin-Film System

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    Abstract—Structural and magnetic measurements are made of an Al2O3/Ge-p/Al2O3/Co thin-film system. The structure is synthesized via ion-plasma deposition and can be used as a tunnel heterostructure. The dependences of the magnetic properties of cobalt on the rate of its deposition and the rates of deposition of preceding layers are established

    Pathophysiological changes at single and multiple introduction of Ciprofloxacin solution under experimental conditions

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    The article presents the results of experimental biological modelling of single and subacute introduction of Ciprofloxacin to the rabbits. State of an organism of animals was estimated by biochemical, hematological, hemostatic and morphologic indices. Introduction of preparation samples was intravenous, according to the Instruction of medical use. Main result of the experiments is determination of toxic effects that are typical for fluorinequinolone and developed on the background of multiple introduction of preparation in the doses higher than therapeutic

    EVALUATION OF TOXICITY OF INFUSION SOLUTION OF POTASSIUM AND MAGNESIUM ASPARAGINATE 500 ML IN EXPERIMENT

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    We carried out an experimental research of infusion solution of potassium, and magnesium asparaginate at the single and. repeated introduction to the animals (rabbits). We determined the fact of the demonstration of toxic features of the preparation at single introduction in shock doze (243,5 mg/kg): increase of hepatic enzymes activity and. of some other biochemical indices, decrease of cardiac beat rhythm and. appearance of plural extrasystoles

    TO THE POSSIBILITY OF REVEALING OF SIDE EFFECTS OF METRONIDAZOLE (0,5% INFUSION SOLUTION, 100 ML) IN EXPERIMENT

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    An. experimental research, of infusion solution of Metronidazole at single and repeated administration to the animals (rabbits) was carried out. Distinct signs of toxicity of the researched pattern. in the dose that is ten times higher than maximum, daily dose were determined. It concerns statistically reliably changed hematologic, biochemical and. electrophysiological indices that are typical for Metronidazole in particular. Only the fact of increase of content of creatinine in blood serum in 2 weeks after the administration, of the preparation should be registered but in this case it can be the signal to stop further administration, of the preparation

    Половые отличия пула свободных аминокислот-нейромедиаторов у крыс Крушинского-Молодкиной

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    The study of the role of neurotransmitter systems in the pathogenesis of epilepsy is one of the priorities of epileptology. New data on the functions of free neurotransmitter-like amino acid in the central nervous system are of the greatest importance and determine the prospects for the development of novel effective anticonvulsants. It is widely believed in clinical medicine that epilepsy has distinct gender characteristics. The aim of this study was to investigate the gender peculiarities in the content of neurotransmitter amino acids in the brain of Krushinsky-Molodkina (KM) rats, which were used as model organisms for the study of genetically induced audiogenic epilepsy. The content of Asp, Glu, GABA, Gly, and Tau of the medulla oblongata, hippocampus and cerebral cortex were determined using high-performance liquid chromatography (HPLC) in intact KM rats, KM rats exposed to a series of epileptiform seizures, and Wistar rats (control group). Both the Wistar and KM rats had gender distinctions in the distribution of free amino acids among the investigated brain parts. The audiogenic epilepsy was characterized by smoothing gender differences as well as differences between the concentrations of free amino acids in the cortex and medulla oblongata, specific for Wistar rats. The changes observed in male rats after the set of seizures included the increase in GABA concentration and a decrease in the Gly level in all investigated brain parts, as well as the decrease of the Tau content in the cortex and hippocampus. At the same time, the Glu content in cortex increased, while the Asp level decreased. After 6 days of audiogenic stimulations the female KM rats demonstrated the increase in the Glu level in all investigated brain parts, the increase in Gly and Asp levels in hippocampus, and no changes in the GABA content. Thus, after the set of epileptiform seizures the KM rats achieved a new steady state of the studied amino acids pool, which differed in males and females. In this case, gender differences significantly changed after the seizures. © 2020 Russian Academy of Medical Sciences. All rights reserved.The work was performed within the framework of the state task of the IIF UB RAS (Registration number AAAA-A18-118020590108-7)

    Type II Radio Emission and Solar Particle Observations

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    The 28 October 2003 flare gave us the unique opportunity to compare the acceleration time of high-energy protons with the escaping time of those particles which have been measured onboard spacecraft and by neutron monitors network as GLE event. High-energy emission time scale and shock wave height and velocity time dependencies were also studied.Comment: International Journal of Modern Physics A, Volume 20, Issue 29, pp. 6705-6707 (2005
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