Effects of Turbulent Mixing on the Critical Behavior

Effects of strongly anisotropic turbulent mixing on the critical behavior are studied by means of the renormalization group. Two models are considered: the equilibrium model A, which describes purely relaxational dynamics of a nonconserved scalar order parameter, and the Gribov model, which describes the nonequilibrium phase transition between the absorbing and fluctuating states in a reaction-diffusion system. The velocity is modelled by the d-dimensional generalization of the random shear flow introduced by Avellaneda and Majda within the context of passive scalar advection. Existence of new nonequilibrium types of critical regimes (universality classes) is established.Comment: Talk given in the International Bogolyubov Conference "Problems of Theoretical and Mathematical Physics" (Moscow-Dubna, 21-27 August 2009

Salt sensitivity and timed drug therapy in arterial hypertension. Enhancing antihypertensive drug efficacy: a controlled randomised trial

Background. An elevated or inadequate sensitivity to salt intake is an important mechanism for maintaining high blood pressure in patients with arterial hypertension. Chronopharmacotherapy comprises an important approach to control arterial hypertension through personalised correction of blood pressure but requires a further proof of efficacy in salt-sensitive hypertensive patients.Objectives. An assessment of six-month dynamics of diurnal and nocturnal peripheral and central blood pressure in salt-sensitive patients with arterial hypertension under chronopharmacothe­rapy.Methods. A controlled randomised trial included 86 salt-sensitive patients with arterial hypertension. Salt sensitivity was estimated with a Kharchenko’s test. All patients had circadian monitoring of the peripheral and central blood pressure and glomerular filtration rate at baseline and in a six-month follow-up. The patients were randomised into 3 cohorts. Cohort A united patients received perindopril and amlodipine in morning, cohort B — perindopril in morning, amlodipine in evening, cohort C — perindopril in evening, amlodipine in morning. Statistica 12 (StatSoftInc, USA) was used for nonparametric statistical analyses.Results. In six months of chronopharmacotherapy a target arterial pressure was registered in 87.5% patients in cohort A, 96.4 and 96.2% patients in cohorts B and C, respectively. All cohorts exhibited a declining peripheral and central blood pressure over therapy. Cohort A had a greater decline in daytime, and cohorts B and C — both diurnally and nocturnally. Cohorts B and C had more patients with an adequate nocturnal blood pressure decline. Glomerular filtration rate also elevated with perindopril or amlodipine intake before bedtime.Conclusion. The perindopril or amlodipine intake before bedtime in a combined therapy for arterial hypertension provided for a target blood pressure in the overall majority of patients, effectively reduced peripheral and central blood pressure at all time intervals, contributed to optimising the circadian blood pressure profile and increased the glomerular filtration rate

Two-dimensional magnetoexcitons in the presence of spin-orbit coupling

We study theoretically the effect of spin-orbit coupling on quantum well excitons in a strong magnetic field. We show that, in the presence of an in-plane field component, the excitonic absorption spectrum develops a double-peak structure due to hybridization of bright and dark magnetoexcitons. If the Rashba and Dresselhaus spin-orbit constants are comparable, the magnitude of splitting can be tuned in a wide interval by varying the azimuthal angle of the in-plane field. We also show that the interplay between spin-orbit and Coulomb interactions leads to an anisotropy of exciton energy dispersion in the momentum plane. The results suggest a way for direct optical measurements of spin-orbit parameters.Comment: 9 pages, 6 figure

Non-Linear Algebra and Bogolubov's Recursion

Numerous examples are given of application of Bogolubov's forest formula to iterative solutions of various non-linear equations: one and the same formula describes everything, from ordinary quadratic equation to renormalization in quantum field theory.Comment: LaTex, 21 page

Sequential superradiant scattering from atomic Bose-Einstein condensates

We theoretically discuss several aspects of sequential superradiant scattering from atomic Bose-Einstein condensates. Our treatment is based on the semiclassical description of the process in terms of the Maxwell-Schroedinger equations for the coupled matter-wave and optical fields. First, we investigate sequential scattering in the weak-pulse regime and work out the essential mechanisms responsible for bringing about the characteristic fan-shaped side-mode distribution patterns. Second, we discuss the transition between the Kapitza-Dirac and Bragg regimes of sequential scattering in the strong-pulse regime. Finally, we consider the situation where superradiance is initiated by coherently populating an atomic side mode through Bragg diffraction, as in studies of matter-wave amplification, and describe the effect on the sequential scattering process.Comment: 9 pages, 4 figures. Submitted to Proceedings of LPHYS'06 worksho

Anomalous exponents in the rapid-change model of the passive scalar advection in the order ϵ3\epsilon^{3}

Field theoretic renormalization group is applied to the Kraichnan model of a passive scalar advected by the Gaussian velocity field with the covariance $- <{\bf v}(t,{\bf x}){\bf v}(t',{\bf x'})> \propto\delta(t-t')|{\bf x}-{\bf x'} |^{\epsilon}$. Inertial-range anomalous exponents, related to the scaling dimensions of tensor composite operators built of the scalar gradients, are calculated to the order $\epsilon^{3}$ of the $\epsilon$ expansion. The nature and the convergence of the $\epsilon$ expansion in the models of turbulence is are briefly discussed.Comment: 4 pages; REVTeX source with 3 postscript figure

Study of the ρ\rho, ω\omega, ϕ→ηγ→7γ\phi\to\eta\gamma\to 7\gamma Decays with an SND Detector on a VEPP-2M Collider

The $e^+e^-\to\eta\gamma\to 7\gamma$ process was studied in the energy range $2E=600\div 1060$ MeV with an SND detector on a VEPP-2M $e^+e^-$ collider. The decay branching ratios $B(\phi\to\eta\gamma)=(1.343\pm 0.012\pm 0.055)\cdot 10^{-2}$, $B(\omega\to\eta\gamma)=(4.60\pm 0.72\pm 0.19)\cdot 10^{-4}$, and $B(\rho\to\eta\gamma)=(2.69\pm 0.32\pm 0.16)\cdot 10^{-4}$ were measured.Comment: 5 pages, 4 figure

The Minimum Stellar Mass in Early Galaxies

The conditions for the fragmentation of the baryonic component during merging of dark matter halos in the early Universe are studied. We assume that the baryonic component undergoes a shock compression. The characteristic masses of protostellar molecular clouds and the minimum masses of protostars formed in these clouds decrease with increasing halo mass. This may indicate that the initial stellar mass function in more massive galaxies was shifted towards lower masses during the initial stages of their formation. This would result in an increase of the number of stars per unit halo mass, i.e., the efficiency of star formation.Comment: 18 pages, 7 figure

Сальважная лимфаденэктомия у пациентов с рецидивом рака предстательной жедезы после радикальной простатэктомии

A separate group of patients who underwent radical prostatectomy, make patients with isolated recurrence of cancer in the lymph nodes, limited by regional and / or retroperitoneal lymph nodes. Alternatively, treatment of this patient group can be used open or laparoscopic lymphadenectomy (robot-assisted). The analysis of literature indicate an increase in disease-free survival of these patients during lymphadenectomy. Imaging techniques such as multiparametric magnetic resonance imaging and positron emission tomography, allow more accurately identify lymph nodes in patients with biochemical recurrence of prostate cancer after radical prostatectomy. Отдельную группу больных, перенесших радикальную простатэктомию, составляют пациенты с изолированным рецидивом рака в лимфатических узлах, ограниченных регионарными и / или забрюшинными лимфатическими узлами. В качестве одного из вариантов лечения данной группы пациентов может быть применена лимфаденэктомия открытым или лапароскопическим (робот-ассистированным) доступами. Проведенный анализ литературных источников указывает на увеличение общей выживаемости данной группы пациентов при проведении лимфаденэктомии. Доступные методы визуализации, такие как мультипараметрическая магнитно-резонансная томография и позитронно-эмиссионная томография, позволяют более точно идентифицировать поражение лимфатических узлов у пациентов с биохимическим рецидивом рака простаты после радикальной простатэктомии.

Magnetic Resonance of the Intrinsic Defects of the Spin-Peierls Magnet CuGeO3

ESR of the pure monocrystals of CuGeO3 is studied in the frequency range 9-75 GHz and in the temperature interval 1.2-25 K. The splitting of the ESR line into several spectral components is observed below 5 K, in the temperature range where the magnetic susceptibility is suppressed by the spin-Peierls dimerization. The analysis of the magnetic resonance signals allows one to separate the signals of the S=1/2- and S=1 defects of the spin-Peierls phase. The value of g-factor of these signals is close to that of the Cu-ion. The additional line of the magnetic resonance is characterized by an anomalous value of the g-factor and by the threshold-like increase of the microwave susceptibility when the microwave power is increasing. The ESR signals are supposingly attributed to two types of the planar magnetic defects, arising at the boundaries of the domains of the spin-Peierls state with the different values of the phase of the dimerization.Comment: LATEX-text, 12 PS-figures, typos corrected, LATEX-style change