25,809 research outputs found
Counting real rational functions with all real critical values
We study the number of real rational degree n functions (considered up to
linear fractional transformations of the independent variable) with a given set
of 2n-2 distinct real critical values. We present a combinatorial reformulation
of this number and pose several related questions.Comment: 12 pages (AMSTEX), 3 picture
On total reality of meromorphic functions
We show that if a meromorphic function of degree at most four on a real
algebraic curve of an arbitrary genus has only real critical points then it is
conjugate to a real meromorphic function after a suitable projective
automorphism of the image.Comment: 13 page
The significance of ACTH for the process of formation of complex heparin compounds in the blood during immobilization stress
Adrenocorticotropin (ACTH) was administered to rats at different times following adrenalectomy. Adrenocorticotropin caused a significant increase in the formation of heparin complexes even in the absence of stress factor. When ACTH secretion is blocked, immobilization stress is not accompanied by an increase in the process of complex formation. The effect of ACTH on the formation of heparin complexes was mediated through its stimulation of the adrenal cortex
Complete transfer of populations from a single state to a pre-selected superposition of states using Piecewise Adiabatic Passage
We develop a method for executing robust and selective transfer of
populations between a single level and pre-selected superpositions of energy
eigenstates. Viewed in the frequency domain, our method amounts to executing a
series of simultaneous adiabatic passages into each component of the target
superposition state. Viewed in {the} time domain, the method works by
accumulating the wavefunction of the target wave packet as it revisits the
Franck Condon region, in what amounts to an extension of the Piecewise
Adiabatic Passage technique [ Shapiro et.al., Phys. Rev. Lett. 99, 033002
(2007)] to the multi-state regime. The viability of the method is verified by
performing numerical tests for the Na_2 molecule.Comment: 8 pages, 4 figure
Participation of the hypophyseal-adrenal cortex system in thrombin clearance during immobilization stress
Thrombin marked with I-131 resulted in a considerable increase of the thrombined clearance rate in healthy male rats during stress caused by an immobilization lasting 30 minutes, and in an increase of thrombin clearance occurred by a combination of immobilization and administration of adrenocorticotropin (ACTH). Contrary to ACTH, the thrombin clearance is not stimulated in healthy animals by hydrocortisone. The results of the examination are presented
The role of ACTH and glucocorticoids in nonenzymatic fibrinolysis during immobilization stress in animals
The role of the altered hormonal status of an organism in the activation of the anticoagulative system during stress is investigated. The 30 minute immobilization stress was shown to raise significantly the nonenzymatic fibrinolytic activity of blood in rats. Combined with adrenocorticotropin (ACTH) the effect is still greater. Intravenous administration of 0.2 m1 0.01 percent solution of protamine sulphate prevented the nonenzymatic fibrinolysis induced by the stress. Administration of ACTH after protomine sulphate again raised the fibrinolysis. This suggests that ACTH stimulates the release of heparin
Anderson localization of a Bose-Einstein condensate in a 3D random potential
We study the effect of Anderson localization on the expansion of a
Bose-Einstein condensate, released from a harmonic trap, in a 3D random
potential. We use scaling arguments and the self-consistent theory of
localization to show that the long-time behavior of the condensate density is
controlled by a single parameter equal to the ratio of the mobility edge and
the chemical potential of the condensate. We find that the two critical
exponents of the localization transition determine the evolution of the
condensate density in time and space.Comment: 4 pages, 2 figure
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