802 research outputs found
Assessment of β-D-Glucosidase Activity from Two Typical Strains of the Lactic Acid Bacteria, Oenococcus oeni, in China
β-D-glucosidase (βG) is one of the most interesting glycosidases for the hydrolysis of glycoconjugatedprecursors to release active aromatic compounds in musts and wines. Oenococcus oeni strains SD-2a and31MBR are widely used in Chinese wines to reduce the acidity. In the present study, the βG activity of thetwo strains was localised and partially characterised using synthetic substrate. The activity occurred inwhole cells, sonication supernatants and debris, but not in the culture supernatants for both strains. Wholecells of strain SD-2a possessed greater βG activity, while strain 31MBR showed higher enzyme activity inthe sonication supernatants. Strain 31MBR exhibited higher total enzyme activity than strain SD-2a. Theoptimum temperatures for βG from the two strains were 40ºС at pH 3.5 and 50ºС at pH 5.0, respectively.Ethanol at low concentrations had a positive effect on βG activity in both strains, while a wine-like pH (3.5)decreased the enzyme activity to a great extent. Whole cells of strain SD-2a showed the highest activityamong all samples tested under wine-like conditions. Thus, strain SD-2a proved to have potential foraroma improvement in winemaking
Passenger transmission and productiveness of transit lines with high loads
Deterministic transit capacity analysis applies to planning, design and operational management of urban transit systems. The Transit Capacity and Quality of Service Manual (1) and Vuchic (2, 3) enable transit performance to be quantified and assessed using transit capacity and productive capacity. This paper further defines important productive performance measures of an individual transit service and transit line. Transit work (p-km) captures the transit task performed over distance. Passenger transmission (p-km/h) captures the passenger task delivered by service at speed. Transit productiveness (p-km/h) captures transit work performed over time. These measures are useful to operators in understanding their services’ or systems’ capabilities and passenger quality of service. This paper accounts for variability in utilized demand by passengers along a line and high passenger load conditions where passenger pass-up delay occurs. A hypothetical case study of an individual bus service’s operation demonstrates the usefulness of passenger transmission in comparing existing and growth scenarios. A hypothetical case study of a bus line’s operation during a peak hour window demonstrates the theory’s usefulness in examining the contribution of individual services to line productive performance. Scenarios may be assessed using this theory to benchmark or compare lines and segments, conditions, or consider improvements
Magnetization Plateaux in Bethe Ansatz Solvable Spin-S Ladders
We examine the properties of the Bethe Ansatz solvable two- and three-leg
spin- ladders. These models include Heisenberg rung interactions of
arbitrary strength and thus capture the physics of the spin- Heisenberg
ladders for strong rung coupling. The discrete values derived for the
magnetization plateaux are seen to fit with the general prediction based on the
Lieb-Schultz- Mattis theorem. We examine the magnetic phase diagram of the
spin-1 ladder in detail and find an extended magnetization plateau at the
fractional value in agreement with the experimental observation
for the spin-1 ladder compound BIP-TENO.Comment: 11 pages, 1 figur
Polarization of AGN in UV Spectral Range
We present the review of some new problems in cosmology and physics of stars
in connection with future launching of WSO. We discuss three problems. UV
observations of distant z > 6 quasars allow to obtain information on the soft <
1 KeV X-ray radiation of the accretion disk around a supermassive black hole
because of its cosmological redshift. Really the region of X-ray radiation is
insufficiently investigated because of high galactic absorption. In a result
one will get important information on the reionization zone of the Universe.
Astronomers from ESO revealed the effect of alignment of electric vectors of
polarized QSOs. One of the probable mechanism of such alignment is the
conversion of QSO radiation into low mass pseudoscalar particles (axions) in
the extragalactic magnetic field. These boson like particles have been
predicted by new SUSY particle physics theory. Since the probability of such
conversion is increasing namely in UV spectral range one can expect the strong
correlation between UV spectral energy distribution of QSO radiation and
polarimetric data in the optical range. In the stellar physics one of the
interesting problems is the origin of the X-ray sources with super Eddington
luminosities. The results of UV observations of these X-ray sources will allow
to find the origin of these sources as accreting intermediate mass black holes.Comment: 6 pages, 3 figure
Stability and metastability of skyrmions in thin lamellae of Cu2OSeO3
We report small-angle x-ray scattering measurements of the skyrmion lattice in two 200-nm-thick Cu2OSeO3 lamellae aligned with the applied magnetic field parallel to the out of plane [110] or [100] crystallographic directions. Our measurements show that the equilibrium skyrmion phase in both samples is expanded significantly compared to bulk crystals, existing between approximately 30 and 50 K over a wide region of magnetic field. This skyrmion state is elliptically distorted at low fields for the [110] sample, and symmetric for the [100] sample, possibly due to crystalline anisotropy becoming more important at this sample thickness than it is in bulk samples. Furthermore, we find that a metastable skyrmion state can be observed at low temperature by field cooling through the equilibrium skyrmion pocket in both samples. In contrast to the behavior in bulk samples, the volume fraction of metastable skyrmions does not significantly depend on cooling rate. We show that a possible explanation for this is the change in the lowest temperature of the skyrmion state in this lamellae compared to bulk, without requiring different energetics of the skyrmion state
Rms-flux relation in the optical fast variability data of BL Lacertae object S5 0716+714
The possibility that BL Lac S5 0716+714 exhibits a linear root mean square
(rms)-flux relation in its IntraDay Variability (IDV) is analysed. The results
may be used as an argument in the existing debate regarding the source of
optical IDV in Active Galactic Nuclei. 63 time series in different optical
bands were used. A linear rms-flux relation at a confidence level higher than
65% was recovered for less than 8% of the cases. We were able to check if the
magnitude is log-normally distributed for eight timeseries and found, with a
confidence > 95%, that this is not the case.Comment: Accepted by Astrophysics and Space Scienc
Exact diagonalization of the generalized supersymmetric t-J model with boundaries
We study the generalized supersymmetric model with boundaries in three
different gradings: FFB, BFF and FBF. Starting from the trigonometric R-matrix,
and in the framework of the graded quantum inverse scattering method (QISM), we
solve the eigenvalue problems for the supersymmetric model. A detailed
calculations are presented to obtain the eigenvalues and Bethe ansatz equations
of the supersymmetric model with boundaries in three different
backgrounds.Comment: Latex file, 32 page
Resolving the Azimuthal Ambiguity in Vector Magnetogram Data with the Divergence-Free Condition: Application to Discrete Data
We investigate how the divergence-free property of magnetic fields can be
exploited to resolve the azimuthal ambiguity present in solar vector
magnetogram data, by using line-of-sight and horizontal heliographic derivative
information as approximated from discrete measurements. Using synthetic data we
test several methods that each make different assumptions about how the
divergence-free property can be used to resolve the ambiguity. We find that the
most robust algorithm involves the minimisation of the absolute value of the
divergence summed over the entire field of view. Away from disk centre this
method requires the sign and magnitude of the line-of-sight derivatives of all
three components of the magnetic field vector.Comment: Solar Physics, in press, 20 pages, 11 figure
Directed evolution and predictive modelling of galactose oxidase towards bulky benzylic and unactivated secondary alcohols
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Solutions of the reflection equation for face and vertex models associated with and
We present new diagonal solutions of the reflection equation for elliptic
solutions of the star-triangle relation. The models considered are related to
the affine Lie algebras and
. We recover all known diagonal solutions associated with these
algebras and find how these solutions are related in the elliptic regime.
Furthermore, new solutions of the reflection equation follow for the associated
vertex models in the trigonometric limit.Comment: 10 pages, LaTeX, no figure
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