3,677 research outputs found
Is the Convergence of Accounting Standards Good for Stock Markets?
This paper examines the impact of the convergence of Hong Kong Accounting Standard 40 (HKAS 40) with the International Financial Reporting Standard (IFRS) on the stock prices of firms in the property industry. Using a sample of 22111 firm-day observations, we show that the new standard has a negative impact on the stock performance of these firms.Hong Kong Accounting Standard 40, Event Window, Stock Return.
Crosstalk between astrocytic CXCL12 and microglial CXCR4 contributes to the development of neuropathic pain
published_or_final_versio
Waveguiding and photoluminescence in Er<sup>3+</sup>-doped Ta<sub>2</sub>O<sub>5</sub> planar waveguides
The optimization of erbium-doped Ta2O5 thin film waveguides deposited by magnetron sputtering onto thermally oxidized silicon wafer is described. Optical constants of the film were determined by ellipsometry. For the slab waveguides, background losses below 0.4dB/cm at 633nm have been obtained before post-annealing. The samples, when pumped at 980nm yielded abroad photoluminescence spectrum (FWHM ~50 nm) centred at 1534nm, corresponding to 4 I 13/2 to the 4 I 15/2 transition of Er3+ ion. The samples were annealed up to 600 °C and both photoluminescence power and fluorescence lifetime increase with post-annealing temperature and a fluorescence lifetime of 2.4ms was achieved, yielding promising results for compact waveguide amplifier
A two-year randomized clinical trial of chlorhexidine varnish on dental caries in Chinese preschool children
The objective of this study was to assess the effect of six-monthly professional applications of chlorhexidine varnish on the prevention of dental caries in primary molars in Chinese preschool children. In a double-blinded, randomized, placebo-controlled clinical trial, 334 children aged 4-5 years were randomly divided into two groups. Children in the test group received six-monthly applications of a 40% chlorhexidine varnish, and the control children received a placebo varnish. Caries status of the children was assessed by two calibrated examiners at baseline and after 24 months, according to criteria recommended by the World Health Organization. The two-year mean caries increments in the test and the control group children were 1.0 and 1.6 decayed, missing, or filled molar surfaces (dmfs-molar), respectively, a 37.3% reduction (t test, p = 0.036). No side-effects were found. It was concluded that six-monthly applications of chlorhexidine varnish were effective in reducing the incidence of dental caries in primary molars.published_or_final_versio
Dynamics of ferroelectric nano cluster in BaTiO3 observed as a real time correlation between two soft X-ray laser pulses
We carry out a theoretical investigation to clarify the dynamic property of
photo-created nano-sized ferroelectric cluster observed in the paraelectric
BaTiO3 as a real time correlation of speckle pattern between two soft X-ray
laser pulses, at just above the paraelectric-ferroelectric phase transition
temperature. Based on a model with coupled soft X-ray photon and ferroelectric
phonon mode, we study the time dependence of scattering probability by using a
perturbative expansion approach. The cluster-associated phonon softening as
well as central peak effects are well reproduced in the phonon spectral
function via quantum Monte Carlo simulation. Besides, it is found that the time
dependence of speckle correlation is determined by the relaxation dynamics of
ferroelectric clusters. Near the transition point, cluster excitation is
stable, leading to a long relaxation time. While, at high temperature, cluster
structure is subject to the thermal fluctuation, ending up with a short
relaxation time.Comment: 9 pages, 3 figure
Pseudo-unitary symmetry and the Gaussian pseudo-unitary ensemble of random matrices
Employing the currently discussed notion of pseudo-Hermiticity, we define a
pseudo-unitary group. Further, we develop a random matrix theory which is
invariant under such a group and call this ensemble of pseudo-Hermitian random
matrices as the pseudo-unitary ensemble. We obtain exact results for the
nearest-neighbour level spacing distribution for (2 X 2) PT-symmetric
Hamiltonian matrices which has a novel form, s log (1/s) near zero spacing.
This shows a level repulsion in marked distinction with an algebraic form in
the Wigner surmise. We believe that this paves way for a description of varied
phenomena in two-dimensional statistical mechanics, quantum chromodynamics, and
so on.Comment: 9 pages, 2 figures, LaTeX, submitted to the Physical Review Letters
on August 20, 200
Recording advances for neural prosthetics
An important challenge for neural prosthetics research is to record from populations of neurons over long periods of time, ideally for the lifetime of the patient. Two new advances toward this goal are described, the use of local field potentials (LFPs) and autonomously positioned recording electrodes. LFPs are the composite extracellular potential field from several hundreds of neurons around the electrode tip. LFP recordings can be maintained for longer periods of time than single cell recordings. We find that similar information can be decoded from LFP and spike recordings, with better performance for state decodes with LFPs and, depending on the area, equivalent or slightly less than equivalent performance for signaling the direction of planned movements. Movable electrodes in microdrives can be adjusted in the tissue to optimize recordings, but their movements must be automated to be a practical benefit to patients. We have developed automation algorithms and a meso-scale autonomous electrode testbed, and demonstrated that this system can autonomously isolate and maintain the recorded signal quality of single cells in the cortex of awake, behaving monkeys. These two advances show promise for developing very long term recording for neural prosthetic applications
-scaling and heat capacity in relativistic ion collisions
The -scaling method has been applied to the total multiplicity
distribution of the relativistic ion collisions of p+p, C+C and Pb+Pb which
were simulated by a Monte Carlo package, LUCIAE 3.0. It is found that the
-scaling parameter decreases with the increasing of the system size.
Moreover, the heat capacities of different mesons and baryons have been
extracted from the event-by-event temperature fluctuation in the region of low
transverse mass and they show the dropping trend with the increasing of impact
parameter.Comment: version 2: major change: 4 pages, 3 figures; Proceeding of
International Conference on "Strangeness in Quark Matter" (SQM2004), Cape
Town, South Africa, Spet. 2004 (Submitted to J. Phys. G.
normal and anomalous suppressions in a hadron and string cascade model
A mechanism for the effective dissociation of a pair in the colour
electric field of strings is introduced into a hadron and string cascade model,
i.e. JPCIAE, which is based on the LUND model, simulating ultra-relativistic
nucleus - nucleus collisions. This new mechanism together with the known
mechanism of nuclear absorption (both baryons and mesons) could reproduce
fairly the data of the normal and anomalous suppressions in minimum
bias pA, AB (with light projectile), and Pb + Pb collisions at 200 A GeV/c.
However the impact parameter (E_T) dependence of the suppression
factor, both, in S + U and Pb + Pb reactions at 200 A GeV/c and 158 A GeV/c,
respectively, is not well reproduced. We also tested the additional mechanism
of the energy degradation of leading particles, with which both, the normal and
anomalous suppressions in minimum bias pA, AB, and Pb + Pb collisions
and the E_T dependence of the suppression factor are better
reproduced.Comment: 16 pages (RevTex), 6 ps-figures, to be published in J. Phys.
Central administration of C-x-C chemokine receptor type 4 antagonist alleviates the development and maintenance of peripheral neuropathic pain in mice
Aim
To explore the roles of C-X-C chemokine receptor type 4 (CXCR4) in spinal processing of neuropathic pain at the central nervous system (CNS).
Methods
Peripheral neuropathic pain (PNP) induced by partial sciatic nerve ligation (pSNL) model was assessed in mice. Effects of a single intrathecal (central) administration of AMD3100 (intrathecal AMD3100), a CXCR4 antagonist, on pain behavior and pain-related spinal pathways and molecules in the L3-L5 spinal cord segment was studied compare to saline treatment.
Results
Rotarod test showed that intrathecal AMD3100 did not impair mice motor function. In pSNL-induced mice, intrathecal AMD3100 delayed the development of mechanical allodynia and reversed the established mechanical allodynia in a dose-dependent way. Moreover, intrathecal AMD3100 downregulated the activation of JNK1 and p38 pathways and the protein expression of p65 as assessed by western blotting. Real-time PCR test also demonstrated that substance P mRNA was decreased, while adrenomedullin and intercellular adhesion molecule mRNA was increased following AMD3100 treatment.
Conclusion
Our results suggest that central (spinal) CXCR4 is involved in the development and maintenance of PNP and the regulation of multiple spinal molecular events under pain condition, implicating that CXCR4 would potentially be a therapeutic target for chronic neuropathic pain.published_or_final_versio
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