2,437 research outputs found
A New Method of Vibration Analysis of Elastic Systems, Based on the Lagrange Equations of the First Kind
 
Tropospheric forcing of the boreal polar vortex splitting in January 2003
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
Report of the Working Group on the Composition of Ultra High Energy Cosmic Rays
For the first time a proper comparison of the average depth of shower maximum
() published by the Pierre Auger and Telescope Array Observatories
is presented. The distributions measured by the Pierre Auger
Observatory were fit using simulated events initiated by four primaries
(proton, helium, nitrogen and iron). The primary abundances which best describe
the Auger data were simulated through the Telescope Array (TA) Middle Drum (MD)
fluorescence and surface detector array. The simulated events were analyzed by
the TA Collaboration using the same procedure as applied to their data. The
result is a simulated version of the Auger data as it would be observed by TA.
This analysis allows a direct comparison of the evolution of with energy of both data sets. The
measured by TA-MD is consistent with a preliminary simulation of the Auger data
through the TA detector and the average difference between the two data sets
was found to be .Comment: To appear in the Proceedings of the UHECR workshop, Springdale USA,
201
The Simplest Model of the Turning Movement of a Car with its Possible Sideslip
The simplest model of the turning movement of a car with its possiple sideslip is considered. To this end, a nonholonomic problem with nonretaining constraints is solved. The four possible types of the car motion are studied
Shape of primary proton spectrum in multi-TeV region from data on vertical muon flux
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.
Effect of Age on the Hemostatic Function in Patients with Degenerative Diseases of the Large Joints
Background: Aging is associated with an increased hypercoagulable state. Degenerative diseases of the large joints are also accompanied by increased coagulation activity. We investigated the effect of age on the hemostatic function in patients with osteoarthritis. Material and Methods: The study included 192 patients with osteoarthritis admitted to the clinic for primary hip or knee arthroplasty. The patients were categorized into 5 age groups: the age group under 40 years, the 41–to-50 -year age group, the 51–to-60-year age group, the 61-to-70- year age group, and the age group over 70 years. The general blood clotting tests, platelet number, fibrinogen, antithrombin, protein C, TAT, D-dimer, vonWillebrand factor (vWF), PAI-1, ß-thromboglobulin were determined. Results: Among patients with osteoarthritis, the antithrombin III level significantly decreased by the age of 50; however, above the age of 60 there was a distinct decrease in platelet count, and over the age of 70 the activity of the extrinsic coagulation pathway and the plasminogen level dropped significantly. TAT and D-dimer levels were elevated in most of the patients. Conclusion: The decrease in platelet count coupled with the activity of the extrinsic coagulation pathway in elderly osteoarthritic patients may increase blood loss during total arthroplasty; also, the drop in the anticoagulant and fibrinolytic potential may play a negative role in strengthening the prothrombotic state during the postoperative period
Pathophysiological changes at single and multiple introduction of Ciprofloxacin solution under experimental conditions
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
Ultrathin Tropical Tropopause Clouds (UTTCs) : I. Cloud morphology and occurrence
Subvisible cirrus clouds (SVCs) may contribute to dehydration close to the tropical tropopause. The higher and colder SVCs and the larger their ice crystals, the more likely they represent the last efficient point of contact of the gas phase with the ice phase and, hence, the last dehydrating step, before the air enters the stratosphere. The first simultaneous in situ and remote sensing measurements of SVCs were taken during the APE-THESEO campaign in the western Indian ocean in February/March 1999. The observed clouds, termed Ultrathin Tropical Tropopause Clouds (UTTCs), belong to the geometrically and optically thinnest large-scale clouds in the Earth´s atmosphere. Individual UTTCs may exist for many hours as an only 200--300 m thick cloud layer just a few hundred meters below the tropical cold point tropopause, covering up to 105 km2. With temperatures as low as 181 K these clouds are prime representatives for defining the water mixing ratio of air entering the lower stratosphere
Soluble Thrombomodulin and Major Orthopedic Surgery
Background: A high level of soluble thrombomodulin (sTM) is associated with a lower risk of thrombosis but can cause severe bleeding after operations. Deep vein thrombosis (DVT) and blood loss are serious threats after orthopedic surgery. The aim of our pilot study was to evaluate the effect of the preoperative level of sTM on coagulation and inflammation as well as the blood loss and the development of symptomatic DVT after total large joint replacement.
Methods and Results: In all patients (n=50) who underwent total hip or knee replacement, sTM, PrC, D-dimer, vWF, CRP, and platelets were determined before and after the operation. According to the preoperative sTM level, patients were divided into 2 groups: the thrombomodulin low (TML) group (n=25) and thrombomodulin high (TMH) group (n=25). The concentration of sTM was 4.4 [3.4, 4.7] ng/ml in the TML-group and 8.7[7.3, 10.6] ng/ml in the TMH-group. After surgery, D-dimer, vWF, platelet count and CRP were higher and total blood loss was lower in the TML group. In the TML-group, a symptomatic DVT was detected in 3(12%) patients; in the TMH-group, a symptomatic DVT was identified only in 1(4%) case.
Conclusion: These findings support the important role of sTM in coagulation, inflammation, bleeding, and presumably in venous thrombosis after major orthopedic surgery
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