2,234 research outputs found
On integration of the Kowalevski gyrostat and the Clebsch problems
For the Kowalevski gyrostat change of variables similar to that of the
Kowalevski top is done. We establish one to one correspondence between the
Kowalevski gyrostat and the Clebsch system and demonstrate that Kowalevski
variables for the gyrostat practically coincide with elliptic coordinates on
sphere for the Clebsch case. Equivalence of considered integrable systems
allows to construct two Lax matrices for the gyrostat using known rational and
elliptic Lax matrices for the Clebsch model. Associated with these matrices
solutions of the Clebsch system and, therefore, of the Kowalevski gyrostat
problem are discussed. The Kotter solution of the Clebsch system in modern
notation is presented in detail.Comment: LaTeX, 24 page
Etiopathogenesis and principles of myasthenia gravis treatment
The review addresses issues of etiological studies of synaptic defects underlying severe immunological disease of neuromuscular system myasthenia gravis. Current concepts on molecular mechanisms of muscle weakness accompanying this disease are considered, development of new algorithms of myasthenia gravis treatment is discussed
Analytic non-integrability of the Suslov problem
Agraïments: The second author is supported by the grants AGAUR PIV-DGR-2010 and by FCT through CAMGDS, Lisbon
Measurement of decay rate and parameters at KEDR
Using the inclusive photon spectrum based on a data sample collected at the
peak with the KEDR detector at the VEPP-4M collider, we
measured the rate of the radiative decay as well
as mass and width. Taking into account an asymmetric photon
lineshape we obtained keV, MeV/, MeV.Comment: 6 pages, 3 figure
Effects of experimental domestication of silver foxes (Vulpes vulpes) on vocal behaviour
This paper systematizes and generalizes a research cycle devoted to studying the acoustics and vocal behaviour of silver foxes that differ in their tolerance to humans. The research revealed that 50-year selection for tameness toward people resulted in selective use by Tame foxes toward humans of two call types, pant and cackle. At the same time, the selected for aggression toward people Aggressive foxes and the non-selected for behaviour Control foxes, selectively use toward humans cough and snort. Thus, call types representing vocal indicators of friendly and aggressive behaviour of foxes toward humans have been revealed by the research. Nevertheless, experimental domestication did not change vocal behaviour of foxes toward conspecifics; all three strains did not differ by their vocal behaviour toward same-strain silver foxes. Relationship has been investigated between vocal behaviour and degree of tolerance toward people for hybrids between Tame and Aggressive foxes and for backcrosses to Tame and Aggressive foxes. Effect was estimated between fox sex and the degree of human impact on focal fox for variables of fox vocal behaviour. The research revealed the universal for mammals vocal indicators of emotional arousal that are independent of the emotional valence. Characteristics of vocal behaviour that are related with positive and negative emotional valence have been revealed. A simple and effective method for estimating animal discomfort based on ”joint calls” that takes into account the characteristics of all calls irrespective of their acoustic structure has been revealed. The obtained results provide a basis for further comparative studies of the acoustic structure and vocal behaviour for other taxa of the genus Vulpes and the related canid genera (Canis, Cuon, Lycaon)
Measurement of J/psi to eta_c gamma at KEDR
We present a study of the inclusive photon spectra from 5.9 million J/psi
decays collected with the KEDR detector at the VEPP-4M e+e- collider. We
measure the branching fraction of radiative decay J/psi to eta_c gamma, eta_c
width and mass. Our preliminary results are: M(eta_c) = 2979.4+-1.5+-1.9 MeV,
G(eta_c) = 27.8+-5.1+-3.3 MeV, B(J/psi to eta_c gamma) = (2.34+-0.15+-0.40)%.Comment: To be published in Proceedings of the PhiPsi09, Oct. 13-16, 2009,
Beijing, Chin
Use of Levosimendan in Cardiac Anesthesiology
The authors consider the main aspects of the rational use of the novel inotropic drug levosimendan in cardiosurgical patients on the basis of the results of the trials described in the literature and on their own findings in this review. The purpose of the analysis made was to provide a rationale for the effective use of this drug. The review shows the role of the ultrasound indicator left ventricular ejection fraction, the prognostic scale EuroSCORE, and the natriuretic peptides NT-proBNP and BNP in defining indications for levosimendan administration for preoperative preparation. There are original data on the lower level of the natriuretic peptides due to levosimendan therapy. The target hemodynamic monitoring values indicating that it is essential to use levosimendan in postperfusion heart failure are discussed. It is shown that it is expedient to use levosimendan simultaneously with traditional medical measures, by taking into account the pharmacokinetic features of a calcium sensitizer. The problem of levosimendan readministration in patients operated on the heart as well is stated. That there are no clear algorithms for repeated use of the drug is shown. At the same time, possible options of this therapy in different clinical situations are given. Key words: levosimendan, cardiosurgery, heart failure
Measurement of B(J/psi->eta_c gamma) at KEDR
We present a study of the inclusive photon spectrum from 6.3 million J/psi
decays collected with the KEDR detector at the VEPP-4M e+e- collider. We
measure the branching fraction of the radiative decay J/psi -> eta_c gamma,
eta_c width and mass. Taking into account an asymmetric photon line shape we
obtain: M(eta_c) = (2978.1 +- 1.4 +- 2.0) MeV/c^2, Gamma(eta_c) = (43.5 +- 5.4
+- 15.8) MeV, B(J/psi->eta_c gamma) = (2.59 +- 0.16 +- 0.31)%$.Comment: 6 pages, 1 figure. To be published in the proceedings of the 4th
International Workshop on Charm Physics (Charm2010), October 21-24, 2010,
IHEP, Beijin
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