1,030 research outputs found
Early Cosmic Formation of Massive Black Holes
The evolution of nonlinear density fluctuations around the Jeans mass shortly
after cosmological recombination is analyzed using a 3D
hydrodynamics/dark--matter code. The Cosmic Background Radiation (CBR) exerts
Compton friction on free electrons due to peculiar velocities. The dynamics
therefore depends strongly on the gas ionization history. Under a variety of
ionization conditions and in systems with or without non-baryonic components,
the baryons lose angular momentum efficiently and collapse to form a compact
optically--thick object which would probably quickly evolve into a massive
black hole. Attention is concentrated on elucidating some of the novel physical
effects in early cosmological collapses, but ways in which more realistic
calculations might be made and in which the scenario could be incorporated into
a more complete cosmogonic model are discussed.Comment: LaTeX file, figures not included. For hardcopy of figures contact
[email protected]. Institute for Advanced Study number AST 93/11-
Mortality secondary to fulminant hepatic failure in patients with prior resolution of hepatitis B virus infection in Japan
© 2006 by [The University of Chicago Press ]ArticleCLINICAL INFECTIOUS DISEASES. 47(5):E52-E56(2008)journal articl
A generalization of determinant formulas for the solutions of Painlev\'e II and XXXIV equations
A generalization of determinant formulas for the classical solutions of
Painlev\'e XXXIV and Painlev\'e II equations are constructed using the
technique of Darboux transformation and Hirota's bilinear formalism. It is
shown that the solutions admit determinant formulas even for the transcendental
case.Comment: 20 pages, LaTeX 2.09(IOP style), submitted to J. Phys.
Epidemiology of hepatocellular carcinoma in Japan
The original publication is available at www.springerlink.comArticleJOURNAL OF GASTROENTEROLOGY. 44:102-107 (2009)journal articl
Rational Solutions of the Painleve' VI Equation
In this paper, we classify all values of the parameters , ,
and of the Painlev\'e VI equation such that there are
rational solutions. We give a formula for them up to the birational canonical
transformations and the symmetries of the Painlev\'e VI equation.Comment: 13 pages, 1 Postscript figure Typos fixe
CLINICAL AND VIROLOGICAL FEATURES OF PATIENTS WITH FULMINANT HEPATIC FAILURE DUE TO HEPATITIS B VIRUS REACTIVATION FROM HBSAG-NEGATIVE STATUS
ArticleJOURNAL OF HEPATOLOGY. 52(Supplement 1):S286-S286 (2010)conference pape
One-Point Probability Distribution Functions of Supersonic Turbulent Flows in Self-Gravitating Media
Turbulence is essential for understanding the structure and dynamics of
molecular clouds and star-forming regions. There is a need for adequate tools
to describe and characterize the properties of turbulent flows. One-point
probability distribution functions (pdf's) of dynamical variables have been
suggested as appropriate statistical measures and applied to several observed
molecular clouds. However, the interpretation of these data requires comparison
with numerical simulations. To address this issue, SPH simulations of driven
and decaying, supersonic, turbulent flows with and without self-gravity are
presented. In addition, random Gaussian velocity fields are analyzed to
estimate the influence of variance effects. To characterize the flow
properties, the pdf's of the density, of the line-of-sight velocity centroids,
and of the line centroid increments are studied. This is supplemented by a
discussion of the dispersion and the kurtosis of the increment pdf's, as well
as the spatial distribution of velocity increments for small spatial lags. From
the comparison between different models of interstellar turbulence, it follows
that the inclusion of self-gravity leads to better agreement with the observed
pdf's in molecular clouds. The increment pdf's for small spatial lags become
exponential for all considered velocities. However, all the processes
considered here lead to non-Gaussian signatures, differences are only gradual,
and the analyzed pdf's are in addition projection dependent. It appears
therefore very difficult to distinguish between different physical processes on
the basis of pdf's only, which limits their applicability for adequately
characterizing interstellar turbulence.Comment: 38 pages (incl. 17 figures), accepted for publication in ApJ, also
available with full resolution figures at
http://www.strw.leidenuniv.nl/~klessen/Preprint
A highly efficient transient protoplast system for analyzing defence gene expression and protein–protein interactions in rice
The transient assay system based on mesophyll or cultured cell-derived protoplasts has been exploited in several plant species and has become a powerful tool for rapid gene functional analysis and biochemical manipulations. However, the system has not been widely used in rice owing to the difficulties in large-scale isolation of viable rice protoplasts from leaves or suspension-cultured cells. Here, we describe a significantly improved method to isolate a large number of protoplasts from stem and sheath tissues of both young and mature plants. High-level coexpression of multiple constructs and efficient suppression of exogenous and endogenous genes were observed in the stem- and sheath-derived protoplasts. A transient green fluorescent protein and luciferase-based reporter system for defence-related genes expression analysis has been established, which is useful for screening and characterizing genes involved in rice defence signalling pathways. Furthermore, a protoplast-based bimolecular fluorescence complementation (BiFC) system for the detection of protein–protein interactions in living rice cells was developed. The YFP complementation of two split-YFP halves mediated by homodimerization of the GUS and SPIN1, a cell-death related protein, was observed in transfected protoplasts. In combination with genetic, genomic and proteomic approaches, the established versatile protoplast transient assay system will facilitate large-scale functional analysis of defence-related genes in rice
Anti-Helicobacter pylori seropositivity: influence on severity and treatment response in patients with chronic hepatitis C
The definitive version is available at www.blackwell-synergy.comArticleJOURNAL OF VIRAL HEPATITIS. 14(1): 48-54 (2007)journal articl
- …