230 research outputs found

    TEC enhancement due to energetic electrons above Taiwan and the West Pacific

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    The energetic electrons of the inner radiation belt during a geomagnetic disturbance can penetrate in the forbidden range of drift shells located at the heights of the topside equatorial ionosphere (<1000 km). A good correlation was previously revealed between positive ionospheric storms and intense fluxes of quasi-trapped 30-keV electrons at ~900 km height in the forbidden zone. In the present work, we use statistics to validate an assumption that the intense electron fluxes in the topside equatorial ionosphere can be an important source of the ionization in the low-latitude ionosphere. The data on the energetic electrons were obtained from polar orbiting satellites over the periods of the 62 strong geomagnetic storms from 1999 to 2006. Ionospheric response to the selected storms was determined using global ionospheric maps of vertical total electron content (VTEC). A case-event study of a major storm on 9 November 2004 provided experimental evidence in support to the substantial ionization effect of energetic electrons during positive ionospheric storms at the low latitudes. Statistical analysis of nine magnetic storms indicated that the VTEC increases coincided with and coexisted with intense 30-keV electron fluxes irrespective of local time and phase of geomagnetic storm. We concluded that extremely intense fluxes of the 30-keV electrons in the topside low-latitude ionosphere can contribute ~ 10 - 30 TECU to the localized positive ionospheric storms.Comment: 15 pages, 4 figures, 1 table accepted for publication in Terrestrial, Atmospheric and Oceanic Sciences (TAO), Dec. 2012 A special issue on "Connection of solar and heliospheric activities with near-Earth space weather: Sun-Earth connection

    Climatic variability of the mean flow and stationary planetary waves in the NCEP/NCAR reanalysis data

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    NCEP/NCAR (National Center for Environmental Prediction &amp;ndash; National Center for Atmospheric Research) data have been used to estimate the long-term variability of the mean flow, temperature, and Stationary Planetary Waves (SPW) in the troposphere and lower stratosphere. The results obtained show noticeable climatic variabilities in the intensity and position of the tropospheric jets that are caused by temperature changes in the lower atmosphere. As a result, we can expect that this variability of the mean flow will cause the changes in the SPW propagation conditions. The simulation of the SPW with zonal wave number &lt;I&gt;m&lt;/I&gt;=1 (SPW1), performed with a linearized model using the mean flow distributions typical for the 1960s and for the beginning of 21st century, supports this assumption and shows that during the last 40 years the amplitude of the SPW1 in the stratosphere and mesosphere increased substantially. The analysis of the SPW amplitudes extracted from the geopotential height and zonal wind NCEP/NCAR data supports the results of simulation and shows that during the last years there exists an increase in the SPW1 activity in the lower stratosphere. These changes in the amplitudes are accompanied by increased interannual variability of the SPW1, as well. Analysis of the SPW2 activity shows that changes in its amplitude have a different sign in the northern winter hemisphere and at low latitudes in the southern summer hemisphere. The value of the SPW2 variability differs latitudinally and can be explained by nonlinear interference of the primary wave propagation from below and from secondary SPW2

    EVALUATION OF METAPHOR IDENTIFICATION PROCEDURE VU (MIPVU) BY THE CRITERIA OF A TRULY SCIENTIFIC METHOD

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    Due to the growing scholarly interest in metaphor in language, discourse, and thought within cognitive linguistics, metaphor identification is now the center of attention. A lot of methods have been developed to identify metaphors with different degrees of accuracy. The algorithms are based on different theoretical premises; their developers pursue various goals, for example, fully automated computer metaphor search. In order to choose the most reliable method for a given study, it is necessary to evaluate the existing methods by a number of specifically designed criteria. This article is aimed at evaluating Metaphor Identification Procedure VU (MIPVU) by nine criteria that in Russian scientific tradition are considered to be useful for determining whether a method is truly scientific. Before the evaluation is given, the essence of MIPVU (including all steps) is described and a context is analyzed with the help of the procedure, so this paper can also be used for initial familiarization with the procedure

    Higgs Bosons and the Indirect Search for WIMPs

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    We investigated the contribution of the MSSM Higgs bosons produced in the neutralino annihilation in the Earth and Sun to the total WIMPs detection signals. We found that this contribution is very important and results in a lower bound for the muon flux from the Sun of 10^{-7} - 10^{-8} m^{-2} yr^{-1} for neutralinos heavier than 200 GeV. We noticed that due to the SUSY charged Higgs bosons one can expect an energetic tau neutrino flux from the Sun at a level of 10^2 m^{-2} yr^{-1}.Comment: 10 pages, 4 figures. Talk given at Dark2000, Heidelberg, Germany, 10-15 July, 200

    Metabolic Risk Factors and Their Impact on Quality of Life in Patients with Pancreatic Cancer, Acute or Exacerbated Chronic Pancreatitis

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    Аim: to evaluate metabolic risk factors and their impact on quality of life in patients with pancreatic cancer (PC) and in patients with acute or exacerbated chronic pancreatitis.Materials and methods. Forty-five patients with PC (group 1) and 141 patients with acute pancreatitis or exacerbated chronic pancreatitis (group 2) in an observational multicenter clinical cross-sectional uncontrolled study were examined. Clinical, laboratory and instrumental examination of patients and assessment of risk factors (lipid profile, blood plasma glucose, obesity, arterial hypertension) were carried out in accordance with clinical recommendations. Patients completed the SF-36 questionnaire once to assess quality of life at hospital admission before treatment.Results. In group 1, indicators of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) in blood serum (3.7 ± 0.2; 2.2 ± 0.2 and 0.8 ± 0.1 mmol/L) were lower than in group 2 (5.1 ± 0.1; 3.1 ± 0.1 and 1.2 ± 0.1 mmol/L; p &lt; 0.05). Arterial hypertension was more common in group 1 (55.6 %) than in group 2 (34.8 %; p = 0.013). The presence of arterial hypertension increases the chance of having PC by 2.7 times (p &lt; 0.05). Body mass index parameters, including obesity, as well as parameters of triglycerides, and fasting plasma glucose, did not differ between the groups. Logistic regression analysis revealed a direct relationship with PC HDL hypocholesterolemia (Exp B = 4.976; p &lt; 0.001) and arterial hypertension (Exp B = 2.742; p = 0.027) and an inverse relationship — with hypercholesterolemia (Exp B = 0.204; p = 0.002). The chance of having PC was not associated with age, fasting plasma glucose ³ 7.0 mmol/L, obesity. Quality of life indicators were higher in group 1 than in group 2 on four SF-36 scales: bodily pain (68.1 ± 5.1 and 36.8 ± 2.0; p &lt; 0.001), general health (51.1 ± 2.5 and 38.0 ± 1.7 points; p &lt; 0.001), social functioning (74.7 ± 3.0 and 64.5 ± 2.2 points; p = 0.007), role emotional functioning (28.2 ± 5.2 and 12.5 ± 3.1 points; p = 0.007) and in the general domain “physical component of health” (40.2 ± 1.0 and 33.6 ± 0.8 points; p &lt; 0.001). In group 1 with HDL hypocholesterolemia compared with its absence, the indicators of role emotional functioning (22.2 ± 5.1 and 51.9 ± 13.7 points; p = 0.020) were lower, with arterial hypertension compared with its absence — role physical functioning (5.0 ± 4.0 and 25.5 ± 7.5 points; p = 0.036) and role emotional functioning (16.0 ± 5.1 and 43.3 ± 8.8 points; p = 0.007) were lower.Conclusions. In patients with PC arterial hypertension was more common and the levels of total cholesterol, LDL-C and HDL-C were lower than in patients with acute or exacerbated chronic pancreatitis. The chance of having PC is directly associated with HDL hypocholesterolemia, with arterial hypertension, inversely — with hypercholesterolemia, and is not associated with age, fasting plasma glucose ³ 7 mmol/L, or obesity. In patients with PC, quality of life indicators were higher on four SF-36 scales and on the general domain “physical component of health” than in the group with acute or exacerbated chronic pancreatitis. In patients with PC metabolic factors significantly worsened self-assessment of quality of life in terms of role functioning; in patients with acute or exacerbated chronic pancreatitis there was no such association
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