743 research outputs found
ΠΠ½Π°Π»ΠΈΠ· ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠΎΠ² ΠΏΠ»Π°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠ»Π΅ΠΊΡΡΠΎΡΠ½Π°Π±ΠΆΠ΅Π½ΠΈΡ Π² Π₯Π°ΡΡΠΊΠΎΠ²ΡΠΊΠΎΠΌ ΡΠ΅Π³ΠΈΠΎΠ½Π΅
ΠΡΠ΅ΠΊΡΠΈΠ²Π½ΡΡΡΡ ΠΏΡΠΎΡΠ΅ΡΡΠ² Π΅Π»Π΅ΠΊΡΡΠΎΠΏΠΎΡΡΠ°ΡΠ°Π½Π½Ρ Π·Π°ΠΏΡΠΎΠΏΠΎΠ½ΠΎΠ²Π°Π½ΠΎ ΠΎΡΡΠ½ΡΠ²Π°ΡΠΈ Π½Π΅ ΡΡΠ»ΡΠΊΠΈ Π²Π΅Π»ΠΈΡΠΈΠ½ΠΎΡ ΠΏΠΎΠΌΠΈΠ»ΠΊΠΈ ΠΏΡΠΎΠ³Π½ΠΎΠ·ΡΠ²Π°Π½Π½Ρ, Π° ΠΉ ΠΊΡΠ»ΡΠΊΡΡΡΡ Π½Π΅Π³Π°ΡΠΈΠ²Π½ΠΈΡ
Ρ ΠΏΠΎΠ·ΠΈΡΠΈΠ²Π½ΠΈΡ
ΠΏΠΎΠΌΠΈΠ»ΠΎΠΊ, ΡΠΎ Π²ΠΈΠΌΡΡΡΡΡΡΡΡ Π·Π° ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠΎΡ Π’Π΅ΠΉΠ»Π°. ΠΠΈΠΊΠΎΠ½Π°Π½ΠΎ Π°Π½Π°Π»ΡΠ· ΠΏΠ»Π°Π½ΠΎΠ²Π°Π½ΠΈΡ
Ρ ΡΠ°ΠΊΡΠΈΡΠ½ΠΈΡ
Π΄ΠΎΠ±ΠΎΠ²ΠΈΡ
ΠΎΠ±ΡΡΠ³ΡΠ² Π΅Π»Π΅ΠΊΡΡΠΎΡΠΏΠΎΠΆΠΈΠ²Π°Π½Π½Ρ Π² Π₯Π°ΡΠΊΡΠ²ΡΡΠΊΠΎΠΌΡ ΡΠ΅Π³ΡΠΎΠ½Ρ Π² 2008 Ρ 2009 ΡΠΎΠΊΠ°Ρ
. ΠΡΡΠ½Π΅Π½ΠΎ ΠΏΠΎΠΌΠΈΠ»ΠΊΠΈ ΠΏΠ΅ΡΠ΅ΠΎΡΡΠ½ΠΊΠΈ Ρ Π½Π΅Π΄ΠΎΠΎΡΡΠ½ΠΊΠΈ ΡΠ°ΠΊΡΠΈΡΠ½ΠΈΡ
ΠΎΠ±ΡΡΠ³ΡΠ², ΠΎΠ±ΡΠΈΡΠ»Π΅Π½Ρ ΡΠΊΠ»Π°Π΄ΠΎΠ²Ρ Π·Π°Π³Π°Π»ΡΠ½ΠΎΡ ΠΏΠΎΠΌΠΈΠ»ΠΊΠΈ Ρ ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΠΎ ΠΏΠ΅ΡΠ΅Π²Π°ΠΆΠ°Ρ ΠΏΠΎΠΌΠΈΠ»ΠΊΠ° Π½Π΅ΠΏΠΎΠ²Π½ΠΎΡ ΠΊΠΎΠ²Π°ΡΡΠ°ΡΡΡ ΠΏΡΠΎΠ³Π½ΠΎΠ·ΠΎΠ²Π°Π½ΠΈΡ
Ρ ΡΠ°ΠΊΡΠΈΡΠ½ΠΈΡ
Π·Π½Π°ΡΠ΅Π½Ρ Π΄ΠΎΠ±ΠΎΠ²ΠΈΡ
ΠΎΠ±ΡΡΠ³ΡΠ² ΡΠΈΠ½ΠΊΡ ΡΠΏΠΎΠΆΠΈΠ²Π°ΡΡΠ² ΠΠ "Π₯Π°ΡΠΊΡΠ²ΠΎΠ±Π»Π΅Π½Π΅ΡΠ³ΠΎ".The effectiveness of the processes of electricity supply was offered to assess not only with the magnitude of forecasting error, but with the number of negative and positive errors, measured by the method of Theil. The analysis of planned and actual daily volume of electricity in Kharkov region in 2008 and 2009 is realized. Errors of revaluation and underestimation of actual volumes are estimated, components of the general error are calculated and shown that the error of incomplete covariance for predicted and actual values of daily volumes of the market of consumers ΠΠ of "Kharkovo-blenergo" prevails
Superconductor-to-Spin-Density-Wave Transition in Quasi-One-Dimensional Metals with Ising Anisotropy
We study a mechanism for superconductivity in quasi-one-dimensional materials
with Ising anisotropy. In an isolated chain Ising anisotropy opens a spin gap;
if inter-chain coupling is sufficiently weak, single particle hopping is
suppressed and the physics of coupled chains is controlled by a competition
between pair hopping and exchange interaction. Spin density wave and triplet
superconductivity phases are found separated by a first order phase transition.
For particular parameter values a second order transition described by SO(4)
symmetry is found.Comment: 18 pages, 1 figur
Epistatic Interactions in {NS5A} of Hepatitis {C} Virus Suggest Drug Resistance Mechanisms
Hepatitis C virus (HCV) causes a major health burden and can be effectively treated by direct-acting antivirals (DAAs). The non-structural protein 5A (NS5A), which plays a role in the viral genome replication, is one of the DAAs’ targets. Resistance-associated viruses (RAVs) harbouring NS5A resistance-associated mutations (RAMs) have been described at baseline and after therapy failure. A mutation from glutamine to arginine at position 30 (Q30R) is a characteristic RAM for the HCV sub/genotype (GT) 1a, but arginine corresponds to the wild type in the GT-1b; still, GT-1b strains are susceptible to NS5A-inhibitors. In this study, we show that GT-1b strains with R30Q often display other specific NS5A substitutions, particularly in positions 24 and 34. We demonstrate that in GT-1b secondary substitutions usually happen after initial R30Q development in the phylogeny, and that the chemical properties of the corresponding amino acids serve to restore the positive charge in this region, acting as compensatory mutations. These findings may have implications for RAVs treatment
Intersecting Loop Models on Z^D: Rigorous Results
We consider a general class of (intersecting) loop models in D dimensions,
including those related to high-temperature expansions of well-known spin
models. We find that the loop models exhibit some interesting features - often
in the ``unphysical'' region of parameter space where all connection with the
original spin Hamiltonian is apparently lost. For a particular n=2, D=2 model,
we establish the existence of a phase transition, possibly associated with
divergent loops. However, for n >> 1 and arbitrary D there is no phase
transition marked by the appearance of large loops. Furthermore, at least for
D=2 (and n large) we find a phase transition characterised by broken
translational symmetry.Comment: LaTeX+elsart.cls; 30 p., 6 figs; submitted to Nucl. Phys. B; a few
minor typos correcte
Two phase transitions in the fully frustrated model
The fully frustrated model on a square lattice is studied by means of
Monte Carlo simulations. A Kosterlitz-Thouless transition is found at , followed by an ordinary Ising transition at a slightly
higher temperature, . The non-Ising exponents reported by
others, are explained as a failure of finite size scaling due to the screening
length associated with the nearby Kosterlitz-Thouless transition.Comment: REVTEX file, 8 pages, 5 figures in uuencoded postscrip
Evidence for Complex Subleading Exponents from the High-Temperature Expansion of the Hierarchical Ising Model
Using a renormalization group method, we calculate 800 high-temperature
coefficients of the magnetic susceptibility of the hierarchical Ising model.
The conventional quantities obtained from differences of ratios of coefficients
show unexpected smooth oscillations with a period growing logarithmically and
can be fitted assuming corrections to the scaling laws with complex exponents.Comment: 10 pages, Latex , uses revtex. 2 figures not included (hard copies
available on request
Space Station Freedom ground data system: Design and operations
Over the previous year the Space Station Freedom (SSF) Program (SSFP) ground data distribution system has become independent of a number of data systems that were to have been provided by other National Aeronautics and Space Administration (NASA) programs. Consequently, the SSFP has outlined the basic architecture of a new data system dedicated to supporting SSF requirements. This has been accomplished through a complete redesign of the ground network and a reallocation of selected functions. There are a number of aspects of the new ground data distribution system that are unique among NASA programs. These considerations make SSF ground data distribution one of the most extensive and complex data management challenges encountered in the arena of Space Operations. A description of this system comprises the main focus of the paper
Roughening Induced Deconstruction in (100) Facets of CsCl Type Crystals
The staggered 6-vertex model describes the competition between surface
roughening and reconstruction in (100) facets of CsCl type crystals. Its phase
diagram does not have the expected generic structure, due to the presence of a
fully-packed loop-gas line. We prove that the reconstruction and roughening
transitions cannot cross nor merge with this loop-gas line if these degrees of
freedom interact weakly. However, our numerical finite size scaling analysis
shows that the two critical lines merge along the loop-gas line, with strong
coupling scaling properties. The central charge is much larger than 1.5 and
roughening takes place at a surface roughness much larger than the conventional
universal value. It seems that additional fluctuations become critical
simultaneously.Comment: 31 pages, 9 figure
Measurements of the Exerted Pressure by Pelvic Circumferential Compression Devices
Data on the efficacy and safety of non-invasive Pelvic Circumferential Compression Devices (PCCDs) is limited. Tissue damage may occur if a continuous pressure on the skin exceeding 9.3 kPa is sustained for more than two or three hours. The aim of this study was to gain insight into the pressure build-up at the interface, by measuring the PCCD-induced pressure when applying pulling forces to three different PCCDs (Pelvic Binder((R)) , SAM-Sling ((R)) and T-POD((R)) ) in a simplified model. The resulting exerted pressures were measured at four 'anatomical' locations (right, left, posterior and anterior) in a model using a pressure measurement system consisting of pressure cuffs. The exerted pressure varied substantially between the locations as well as between the PCCDs. Maximum pressures ranged from 18.9-23.3 kPa and from 19.2-27.5 kPa at the right location and left location, respectively. Pressures at the posterior location stayed below 18 kPa. At the anterior location pressures varied markedly between the different PCCDs. The circumferential compression by the different PCCDs showed high pressures measured at the four locations using a simplified model. Difference in design and functional characteristics of the PCCDs resulted in different pressure build-up at the four locations. When following the manufacturer's instructions, the exerted pressure of all three PCCDs tested exceeded the tissue damaging level (9.3 kPa). In case of prolonged use in a clinical situation this might put patients at risk for developing tissue damage
Berry phase and adiabaticity of a spin diffusing in a non-uniform magnetic field
An electron spin moving adiabatically in a strong, spatially non-uniform
magnetic field accumulates a geometric phase or Berry phase, which might be
observable as a conductance oscillation in a mesoscopic ring. Two contradicting
theories exist for how strong the magnetic field should be to ensure
adiabaticity if the motion is diffusive. To resolve this controversy, we study
the effect of a non-uniform magnetic field on the spin polarization and on the
weak-localization effect. The diffusion equation for the Cooperon is solved
exactly. Adiabaticity requires that the spin-precession time is short compared
to the elastic scattering time - it is not sufficient that it is short compared
to the diffusion time around the ring. This strong condition severely
complicates the experimental observation.Comment: 16 pages REVTEX, including 3 figure
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