3,002 research outputs found
Universal R-matrix Of The Super Yangian Double DY(gl(1|1))
Based on Drinfeld realization of super Yangian Double DY(gl(1|1)), its
pairing relations and universal R-matrix are given. By taking evaluation
representation of universal R-matrix, another realization of
DY(gl(1|1)) is obtained. These two realizations of DY(gl(1|1)) are related by
the supersymmetric extension of Ding-Frenkel map.Comment: 6 pages, latex, no figure
A WENO Algorithm of the Temperature and Ionization Profiles around a Point Source
We develop a numerical solver for radiative transfer problems based on the
weighted essentially nonoscillatory (WENO) scheme modified with anti-diffusive
flux corrections, in order to solve the temperature and ionization profiles
around a point source of photons in the reionization epoch. Algorithms for such
simulation must be able to handle the following two features: 1. the sharp
profiles of ionization and temperature at the ionizing front (I-front) and the
heating front (T-front), and 2. the fraction of neutral hydrogen within the
ionized sphere is extremely small due to the stiffness of the rate equations of
atom processes. The WENO scheme can properly handle these two features, as it
has been shown to have high order of accuracy and good convergence in capturing
discontinuities and complicated structures in fluid as well as to be
significantly superior over piecewise smooth solutions containing
discontinuities. With this algorithm, we show the time-dependence of the
preheated shell around a UV photon source. In the first stage the I-front and
T-front are coincident, and propagate with almost the speed of light. In later
stage, when the frequency spectrum of UV photons is hardened, the speeds of
propagation of the ionizing and heating fronts are both significantly less than
the speed of light, and the heating front is always beyond the ionizing front.
In the spherical shell between the I- and T-fronts, the IGM is heated, while
atoms keep almost neutral. The time scale of the preheated shell evolution is
dependent on the intensity of the photon source. We also find that the details
of the pre-heated shell and the distribution of neutral hydrogen remained in
the ionized sphere are actually sensitive to the parameters used. The WENO
algorithm can provide stable and robust solutions to study these details.Comment: 24 pages, 7 figures, accepted in New Astronom
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Hemoglobin A1c Levels Modify Associations between Dietary Acid Load and Breast Cancer Recurrence.
BackgroundMetabolic acidosis promotes cancer metastasis. No prospective studies have examined the association between dietary acid load and breast cancer recurrence among breast cancer survivors, who are susceptible to metabolic acidosis. Hyperglycemia promotes cancer progression and acid formation; however, researchers have not examined whether hyperglycemia can modify the association between dietary acid load and breast cancer recurrence.MethodsWe studied 3081 early-stage breast cancer survivors enrolled in the Women's Healthy Eating and Living study who provided dietary information through 24-h recalls at baseline and during follow-up and had measurements of hemoglobin A1c (HbA1c) at baseline. We assessed dietary acid load using two common dietary acid load scores, potential renal acid load (PRAL) score and net endogenous acid production (NEAP) score.ResultsAfter an average of 7.3 years of follow-up, dietary acid load was positively associated with recurrence when baseline HbA1c levels were ≥ 5.6% (median level) and ≥5.7% (pre-diabetic cut-point). In the stratum with HbA1c ≥ 5.6%, comparing the highest to the lowest quartile of dietary acid load, the multivariable-adjusted hazard ratio was 2.15 (95% confidence interval [CI] 1.34-3.48) for PRAL and was 2.31 (95% CI 1.42-3.74) for NEAP. No associations were observed in the stratum with HbA1c levels were <5.6%. P-values for interactions were 0.01 for PRAL and 0.05 for NEAP.ConclusionsOur study demonstrated for the first time that even at or above normal to high HbA1c levels, dietary acid load was associated with increased risk of breast cancer recurrence among breast cancer survivors.ImpactsOur study provides strong evidence for developing specific dietary acid load guidelines based on HbA1c levels
Who is in charge and whose rules are followed..?: Power in a inter-organisational IS project
While Enterprise Resource Planning (ERP) system demand in China has been steadily increasing,
many of such implementation projects failed. Keda Industrial Co. Ltd (600986: Shanghai Stock
Exchange), a manufacturer of large scale machinery in China, however, was one of the few that
successfully deployed its ERP solution in 2005. In this case study, we document the ERP initiative of
Keda from its conception to its deployment, study the factors that contributed to its success, and
summarize Keda’s practices that substantiated the identified success factors
Identification of non-specific lipid transfer protein-1 as a calmodulin-binding protein in Arabidopsis
AbstractAlthough non-specific lipid transfer proteins (nsLTPs) are widely present in plants, their functions and regulations have not been fully understood. In this report, Arabidopsis nsLTP1 was cloned and expressed to investigate its binding to calmodulin (CaM). Gel overlay assays revealed that recombinant nsLTP1 bound to CaM in a calcium-independent manner. The association of nsLTP1 and CaM was corroborated using CaM–Sepharose beads to specifically isolate recombinant nsLTP1 from crude bacterial lysate. The CaM-binding site was mapped in nsLTP1 to the region of 69–80 amino acids. This region is highly conserved among plant nsLTPs, implicating that nsLTPs are a new family of CaM-binding proteins whose functions may be mediated by CaM signaling
Facile hydrothermal synthesis and optical limiting properties of TiO 2 -reduced graphene oxide nanocomposites
TiO2/reduced graphene oxide (RGO) nanocomposites Gx (RGO titania nanocomposite, x grams tetrabutyl titanate per 0.03 g RGO, x = 0.25, 0.50, 1.00) were prepared by a hydrothermal method: graphene oxide was reduced to RGO in a 2:1 water:ethanol mixture in the presence of varying quantities of tetrabutyl titanate, which deposited as TiO2 on the RGO sheets. The nanocomposites were characterized by a combination of Fourier transform infrared spectroscopy, diffuse reflectance ultraviolet-visible spectroscopy, photoluminescence spectroscopy, Raman spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy studies. The nanocomposite G0.25 exhibits enhanced nonlinear optical properties compared to its individual components, which is ascribed to a combination of mechanisms. The role of defects and electron/energy transfer in the optical limiting performance of G0.25 was clarified with the help of Raman and photoluminescence spectroscopies. Intensity-dependent switching between reverse saturable absorption and saturable absorption behavior was observed with the G0.50 nanocomposite
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