3,109 research outputs found
The largest virialized dark halo in the universe
Using semi-analytic approach, we present an estimate of the properties of the
largest virialized dark halos in the present universe for three different
scenarios of structure formation: SCDM, LCDM and OCDM models. The resulting
virial mass and temperature increase from the lowest values of and 9.8 keV in OCDM, the mid-range values of and 31 keV in LCDM, to the highest values of
, 65 keV in SCDM. As compared with the
largest virialized object seen in the universe, the richest clusters of
galaxies, we can safely rule out the OCDM model. In addition, the SCDM model is
very unlikely because of the unreasonably high virial mass and temperature. Our
computation favors the prevailing LCDM model in which superclusters may be
marginally regarded as dynamically-virialized systems.Comment: 5 pages, Accepted by Int. J. Mod. Phys.
A Semantic Graph-Based Approach for Mining Common Topics From Multiple Asynchronous Text Streams
In the age of Web 2.0, a substantial amount of unstructured
content are distributed through multiple text streams in an
asynchronous fashion, which makes it increasingly difficult
to glean and distill useful information. An effective way to
explore the information in text streams is topic modelling,
which can further facilitate other applications such as search,
information browsing, and pattern mining. In this paper, we
propose a semantic graph based topic modelling approach
for structuring asynchronous text streams. Our model in-
tegrates topic mining and time synchronization, two core
modules for addressing the problem, into a unified model.
Specifically, for handling the lexical gap issues, we use global
semantic graphs of each timestamp for capturing the hid-
den interaction among entities from all the text streams.
For dealing with the sources asynchronism problem, local
semantic graphs are employed to discover similar topics of
different entities that can be potentially separated by time
gaps. Our experiment on two real-world datasets shows that
the proposed model significantly outperforms the existing
ones
Tako-tsubo cardiomyopathy after a quarrel.
Objective: To report a case of Tako-tsubo cardiomyopathy in a blind woman.Case presentation: We report a confirmed case of Tako-tsubo cardiomyopathy in a 55-year-old blind woman with past medical history of ocular trauma. The patient suffered from sudden chest pain after a quarrel. Transthoracic echocardiogram (TTE) showed regional wall motion abnormalities. Coronary angiogram showed no significant coronary stenosis, but ventriculogram demonstrated apical ballooning akinesis and hypercontraction in the basal segments. The follow-up TTE revealed a recovery of systolic function 6 weeks later.Conclusion: We report a case of Tako-tsubo cardiomyopathy after a quarrel, implicating that severe emotional or physical stress could trigger myocardial stunning.Keywords: Tako-tsubo cardiomyopathy, ocular trauma, blindness, postmenopaus
Functional renormalization group study of neutral and charged pion under magnetic fields in the quark-meson model
We calculated the masses of neutral and charged pion and pion decay constants
under an extra magnetic field at zero temperature. The quantum fluctuations are
integrated through the functional renormalization group. We consider the quark
and meson propagators in the Landau level representation and weak-field
expansion, respectively. The neutral pion mass monotonically decreases with the
magnetic field, while the charged pion mass monotonically increases with the
magnetic field. The pion decay constant and the quark mass show the magnetic
catalysis behavior at vanishing temperature. The neutral pion mass and pion
decay constant are quantitatively in agreement with the lattice QCD results in
the region of , and no non-monotonic mass behavior for
charged pion has been observed in this framework.Comment: 10 pages, 5 figure
Maillard reaction induces changes in saccharides and amino acids during stir-baking of areca nuts
Purpose: To investigate changes in saccharides and amino acids induced by Maillard reaction (MR) during stir-baking of areca nuts (AN).Methods: The pH of aqueous extracts of AN and charred AN (CAN) were measured by a pH meter, and their absorbances at 420 nm were read in an ultraviolet-visible (UV-VIS) spectrophotometer. Changes in saccharides and amino acids were evaluated by high performance liquid chromatography (HPLC) and automated amino acid analyzer, respectively.Results: The pH of AN (5.85 ± 0.09) was lower than that of CAN (5.25 ± 0.04). Stir-baking significantly increased the A420 value of AN (0.32 ± 0.01 to 0.62 ± 0.02 (CAN). In addition, the contents of reducing saccharides (fructose and glucose) and free amino acids (serine, lysine, arginine and proline) were significantly decreased in the stir-baked CAN compared with AN.Conclusion: MR, during stir-baking of AN, decreases levels of free amino acids and reducing sugars due probably to the reaction between saccharides and amino acids.Keywords: Areca nut, Stir-baking, Maillard reaction, Reducing sugars, Free amino acid
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