The influenza virus neuraminidase inhibitor produced by Staphylococcus aureus

The glycoproteinic complex has been isolated from the Staphylococcus aureus culture fluid possessing an activity inhibiting influenza virus neuraminidase. Two fractions have been further purified containing different monosugars components, the first one has been shown to contain mannose, glucose, rhamnose, glucosamine, and galactosamine, while rhamnose is absent in the second fraction, A component of fraction 1 inhibits the neuraminidase activity and at the same time enhances the virus hemagglutinating activity more strongly comparing to the fraction 2. Some chemical modifications of the substances of the fractions studied (periodate oxidation, protease pretreatment, and delipidization) prove the carbohydrate component of the complex to be responsible for its antineuraminidase activity. The protease pretreatment decreases twice the antineuraminidase activity of the fraction 2 having no influence on this activity of the fraction 1.З культурального середовища золотистого стафілокока (S. aureus) виділено гліколіпопротеїновий комплекс з активністю, що гальмує ней рамінідазу вірусу грипу. Очищено дві фракції з різним вмістом моносахаридів. Показано, що фракція І міс­тить манозу, глюкозу, рамнозу, глюкозамін та галактозамін; друга – всі ці моносахариди, крім рамнози. Речовина з фракції 1 гальмує нейрамінідазну активність та одночасно посилює гемаглютинативну активність вірусу значно сильніше, ніж речовина з фракції 2. Ряд хімічних модифікацій вивчених речовин (перйодатне окислення, обробка протеазою та деліпідизація) підтверджують роль вуглеводного компонента комплексу у здійсненні його антинейрамінідазної дії; обробка протеазою вдвічі знижує антинейрамінідазну активність фракції 2, не впливаючи на таку ж активність фракції 1.Из культуральной среды S. aureus выделен гликолипопротеиновый комплекс с активностью, ингибирующей нейраминидазную активность вируса гриппа. Получены две фракции с различным содержанием моносахаридов, первая из которых включает маннозу, глюкозу, рамнозу, глюкозамин и галактозамин; вто­рая – все эти моносахариды, кроме римнозы. Вещество, содержащееся во фракции I, ингибирует нейраминидазную активность и в то же время усиливает гемагглютинирующую активность вируса гриппа значительно более выражению, чем вещество из фракции 2. Ряд химических модификаций изучаемых фракций (перйодатное окисление, обработка протеазой и делипидизация) доказывает роль углеводного компонента ком­плекса в его антинейраминидазной активности; при этом обработка протеазой вдвое снижает антинейраминидазную активность фракции 2, не влияя на подобную активность фракции 1

Renormalization Group and Decoupling in Curved Space: II. The Standard Model and Beyond

We continue the study of the renormalization group and decoupling of massive fields in curved space, started in the previous article and analyse the higher derivative sector of the vacuum metric-dependent action of the Standard Model. The QCD sector at low-energies is described in terms of the composite effective fields. For fermions and scalars the massless limit shows perfect correspondence with the conformal anomaly, but similar limit in a massive vector case requires an extra compensating scalar. In all three cases the decoupling goes smoothly and monotonic. A particularly interesting case is the renormalization group flow in the theory with broken supersymmetry, where the sign of one of the beta-functions changes on the way from the UV to IR.Comment: 27 pages, 8 figure

On Properties of Vacuum Axial Symmetric Spacetime of Gravitomagnetic Monopole in Cylindrical Coordinates

We investigate general relativistic effects associated with the gravitomagnetic monopole moment of gravitational source through the analysis of the motion of test particles and electromagnetic fields distribution in the spacetime around nonrotating cylindrical NUT source. We consider the circular motion of test particles in NUT spacetime, their characteristics and the dependence of effective potential on the radial coordinate for the different values of NUT parameter and orbital momentum of test particles. It is shown that the bounds of stability for circular orbits are displaced toward the event horizon with the growth of monopole moment of the NUT object. In addition, we obtain exact analytical solutions of Maxwell equations for magnetized and charged cylindrical NUT stars.Comment: 16 pages, 3 figures, 1 tabl

Torsion, an alternative to dark matter?

We confront Einstein-Cartan's theory with the Hubble diagram. An affirmative answer to the question in the title is compatible with today's supernovae data.Comment: 14 pp, 3 figures. Version 2 matches the version published in Gen. Rel. Grav., references added. Version 3 corrects a factor 3 in Cartan's equations to become

On Possible Light-Torsion Mixing in Background Magnetic Field

The interaction of the light with propagating axial torsion fields in the presence of an external magnetic field has been investigated. Axial torsion fields appearing in higher derivative quantum gravity possess two states, with spin one and zero, with different masses. The torsion field with spin-0 state is a ghost that can be removed if its mass is infinite. We investigate the possibility when the light mixes with the torsion fields resulting in the effect of vacuum birefringence and dichroism. The expressions for ellipticity and the rotation of light polarization axis depending on the coupling constant and the external magnetic field have been obtained.Comment: 12 pages, title changed, shortened journal version, accepted in Eur.Phys.J.

Detection of Solar Rotational Variability in the LYRA 190 - 222 nm Spectral Band

We analyze the variability of the spectral solar irradiance during the period from 7 January, 2010 until 20 January, 2010 as measured by the Herzberg channel (190-222 nm) of the Large Yield RAdiometer (LYRA) onboard PROBA2. In this period of time observations by the LYRA nominal unit experienced degradation and the signal produced by the Herzberg channel frequently jumped from one level to another. Both these factors significantly complicates the analysis. We present the algorithm which allowed us to extract the solar variability from the LYRA data and compare the results with SORCE/SOLSTICE measurements and with modeling based on the Code for the Solar Irradiance (COSI)

Scalar-Tensor Gravity and Quintessence

Scalar fields with inverse power-law effective potentials may provide a negative pressure component to the energy density of the universe today, as required by cosmological observations. In order to be cosmologically relevant today, the scalar field should have a mass $m_\phi = O(10^{-33} {\mathrm eV})$, thus potentially inducing sizable violations of the equivalence principle and space-time variations of the coupling constants. Scalar-tensor theories of gravity provide a framework for accommodating phenomenologically acceptable ultra-light scalar fields. We discuss non-minimally coupled scalar-tensor theories in which the scalar-matter coupling is a dynamical quantity. Two attractor mechanisms are operative at the same time: one towards the tracker solution, which accounts for the accelerated expansion of the Universe, and one towards general relativity, which makes the ultra-light scalar field phenomenologically safe today. As in usual tracker-field models, the late-time behavior is largely independent on the initial conditions. Strong distortions in the cosmic microwave background anisotropy spectra as well as in the matter power spectrum are expected.Comment: 5 pages, 4 figure

A sequential quadratic penalty method for nonlinear semidefinite programming

2003-2004 > Academic research: refereed > Publication in refereed journa

A model of the Universe including Dark Energy accounted for by both a Quintessence Field and a (negative) Cosmological Constant

In this work we present a model of the universe in which dark energy is modelled explicitely with both a dynamical quintessence field and a cosmological constant. Our results confirm the possibility of a future collapsing universe (for a given region of the parameter space), which is necessary for a consistent formulation of string theory and quantum field theory. We have also reproduced the measurements of modulus distance from supernovae with good accuracy.Comment: 11 pages, 4 figures, only the results for the single exponential potential are preserved. One author added. Some changes in the reference section. Submitted to Physical Review

Multifractality and critical fluctuations at the Anderson transition

Critical fluctuations of wave functions and energy levels at the Anderson transition are studied for the family of the critical power-law random banded matrix ensembles. It is shown that the distribution functions of the inverse participation ratios (IPR) $P_q$ are scale-invariant at the critical point, with a power-law asymptotic tail. The IPR distribution, the multifractal spectrum and the level statistics are calculated analytically in the limits of weak and strong couplings, as well as numerically in the full range of couplings.Comment: 14 pages, 13 eps figure