74,444 research outputs found

    Reversibility Checking for Markov Chains

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    In this paper, we present reversibility preserving operations on Markov chain transition matrices. Simple row and column operations allow us to create new reversible transition matrices and yield an easy method for checking a Markov chain for reversibility

    Laser-catalyzed spin-exchange process in a Bose-Einstein condensate

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    We show theoretically that it is possible to optically control collective spin-exchange processes in spinor Bose condensates through virtual photoassociation. The interplay between optically induced spin exchange and spin-dependent collisions provides a flexible tool for the control of atomic spin dynamics, including enhanced or inhibited quantum spin oscillations, the optically-induced ferromagnetic-to-antiferromagnetic transition, and coherent matter-wave spin conversion.Comment: 4 pages, 4 figure

    Single chargino production via gluon-gluon fusion in a supersymmetric theory with an explicit R-parity violation

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    We studied the production of single charginoχ~1±\tilde{\chi}_1^{\pm} accompanied by μ∓\mu^{\mp} lepton via gluon-gluon fusion at the LHC. The numerical analysis of their production rates is carried out in the mSUGRA scenario with some typical parameter sets. The results show that the cross sections of the χ~1±μ∓\tilde{\chi}_1^{\pm}\mu^{\mp} productions via gluon-gluon collision are in the order of 1∼1021 \sim 10^{2} femto barn quantitatively at the CERN LHC, and can be competitive with production mechanism via quark-antiquark annihilation process.Comment: LaTex file, 18 pages, 4 EPS file

    Olig2/Plp-positive progenitor cells give rise to Bergmann glia in the cerebellum.

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    NG2 (nerve/glial antigen2)-expressing cells represent the largest population of postnatal progenitors in the central nervous system and have been classified as oligodendroglial progenitor cells, but the fate and function of these cells remain incompletely characterized. Previous studies have focused on characterizing these progenitors in the postnatal and adult subventricular zone and on analyzing the cellular and physiological properties of these cells in white and gray matter regions in the forebrain. In the present study, we examine the types of neural progeny generated by NG2 progenitors in the cerebellum by employing genetic fate mapping techniques using inducible Cre-Lox systems in vivo with two different mouse lines, the Plp-Cre-ER(T2)/Rosa26-EYFP and Olig2-Cre-ER(T2)/Rosa26-EYFP double-transgenic mice. Our data indicate that Olig2/Plp-positive NG2 cells display multipotential properties, primarily give rise to oligodendroglia but, surprisingly, also generate Bergmann glia, which are specialized glial cells in the cerebellum. The NG2+ cells also give rise to astrocytes, but not neurons. In addition, we show that glutamate signaling is involved in distinct NG2+ cell-fate/differentiation pathways and plays a role in the normal development of Bergmann glia. We also show an increase of cerebellar oligodendroglial lineage cells in response to hypoxic-ischemic injury, but the ability of NG2+ cells to give rise to Bergmann glia and astrocytes remains unchanged. Overall, our study reveals a novel Bergmann glia fate of Olig2/Plp-positive NG2 progenitors, demonstrates the differentiation of these progenitors into various functional glial cell types, and provides significant insights into the fate and function of Olig2/Plp-positive progenitor cells in health and disease

    The Nature of Quantum Hall States near the Charge Neutral Dirac Point in Graphene

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    We investigate the quantum Hall (QH) states near the charge neutral Dirac point of a high mobility graphene sample in high magnetic fields. We find that the QH states at filling factors ν=±1\nu=\pm1 depend only on the perpendicular component of the field with respect to the graphene plane, indicating them to be not spin-related. A non-linear magnetic field dependence of the activation energy gap at filling factor ν=1\nu=1 suggests a many-body origin. We therefore propose that the ν=0\nu=0 and ±1\pm1 states arise from the lifting of the spin and sub-lattice degeneracy of the n=0n=0 LL, respectively.Comment: 4 pages, 4 figures, to appear in Phys. Rev. Let

    Do different forms of government ownership matter for bank capital behavior? Evidence from China

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    This study attempts to reconcile the conflicting theoretical predictions regarding how government ownership affects bank capital behaviour. Using a unique Chinese bank dataset over 2006-2015 we find that government-owned banks have higher target capital ratios and adjust these ratios faster compared to private banks, supporting the ‘development/political’ view of the government’s role in banking. This effect is stronger for local government-owned and state enterprise-owned banks than for central government-owned banks. We also find that undercapitalized government-owned banks increase equity while undercapitalized foreign banks contract assets and liabilities as their respective main strategy to adjust their capital ratios
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