Large-scale molecular dynamics simulation of magnetic properties of amorphous iron under pressure

Author name used in this publication: C. H. Woo2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Calderon Multiplicative Preconditioned EFIE With Perturbation Method

In this paper, we address the low-frequency breakdown and inaccuracy problems in the Calderón multiplicative preconditioned electric field integral equation (CMP-EFIE) operator, and propose the perturbation method as a remedy for three-dimensional perfect electric conductor (PEC) scatterers. The electric currents at different frequency orders as a power series can be obtained accurately in a recursive manner by solving the same matrix system with updated right hand side vectors. This method does not either require a search for the loops in the loop-tree/-star based method or include charge as additional unknown in the augmented EFIE method. Numerical examples show the far-field pattern can be accurately computed at extremely low frequencies by the proposed perturbation method. © 1963-2012 IEEE.published_or_final_versio

Solving multi-scale low frequency electromagnetic problems

In this paper, we will discuss two methods to tackle the low-frequency, multi-scale electromagnetics problem. First we will discuss the augmented electric field integral equation (AEFIE), and then, we will discuss the equivalence principle algorithm (EPA). The AEFIE allows the solution of such problems without the need to perform a loop search of a complex structure. The EPA allows the separation of circuit physics from wave physics in a multiscale problem. Hybridization of these two methods will be discussed.published_or_final_versionThe 4th European Conference on Antennas and Propagation (EuCAP) 2010, Barcelona, Spain, 12-16 April 2010. In Proceedings of the 4th EuCAP, 2010, p. 1-

The role of proheparanase in synaptic plasticity at the hippocampus

Abstract no. P-110Perineuronal heparan sulfate (HS) moieties are implicated in the modulation of neurotransmission by controlling the functional properties of AMPA-type glutamate receptors. We hypothesize that neuronal mechanisms modulate peri-synaptic HS level, thereby regulating synaptic strength and plasticity. To address this, basal synaptic strength and long-term changes in synaptic efficacy in the Schaffer collateral pathway of the rat hippocampus were assessed in relation to strategies that perturb peri-synaptic HS. In hippocampal slices, heparitinase treatment led to dose-dependent attenuation of long-term potentiation (LTP) in correlation with loss of perineuronal HS …postprin

Regulatory role of proheparanase with peri-synaptic heparan sulfate proteoglycan and AMPA-type glutamate receptor in synaptic plasticity

Poster Presentation: P59AMPA-type glutamate receptors (AMPAR) govern excitatory synaptic transmission. Perineuronal heparan sulfates (HS) have been implicated in controlling the open-state of AMPAR. Our finding of neuronal heparanase expression in adult rats led us to test (1) if neuronal heparanase is secreted and (2) if the secreted form acts on perineuronal HS to modulate synaptic plasticity. Neuronal secretion of heparanase was triggered by phorbol ester of rat hippocampal neurons in culture. Western blot analysis of the secreted product revealed enzymatically inactive proheparanase, but not the enzymatically active heparanase. Synaptosomes prepared from phorbol ester-treated rat cortexslices showed enrichment in proheparanase; co-immunoprecipitation studies further showed association of AMPAR subunits (GluA1 and GluA2/3) with both syndecan-3 (a transmembrane HS-proteoglycan) and proheparanase, suggesting their partnership in the peri-synaptic environment. Treatment of hippocampal neurons in culture with recombinant proheparanase triggered internalization of proheparanase, perineuronal HS-proteoglycans and AMPARs, suggesting their clustering as a functional complex. Heparitinase pre-treatment of hippocampal neuron cultures reduced proheparanase-induced internalization of AMPARs, suggesting that the HS moiety is critical for effecting the partnership. Treatment of hippocampal slices with recombinant proheparanase resulted in down-regulation of both basal synaptic strength and LTP at Schaffer collateral synapses. These results reveal a novel role of neuronal proheparanase in resetting AMPAR and perineuronal HS levels at the synapse and thus the modulation of synaptic plasticity.postprin

Walking in the cement forest: a health enhancement and pedometer-determined ambulatory (HEPA) program in Hong Kong

Congress Theme: A Celebration of Diversity and Inclusion in Active AgeingThis journal suppl.entitled: Supplement issue: Abstracts for the 8th World Congress on Ageing and Physical Activitypublished_or_final_versionThe 8th Annual World Congress on Active Ageing (WCAA): A Celebration of Diversity and Inclusion in Active Ageing, Glasgow, Scotland, UK, 13 -17 August 2012. In Journal of Aging and Physical Activity, 2012, v. 20, Suppl., p. S226-S22

Walking in the High-rise City: A Health Enhancement and Pedometer-determined Ambulatory (HEPA) Program in Hong Kong

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A home-based exercise intervention for caregivers of persons with dementia: study protocol for a randomised controlled trial

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The study of a single injection of intravitreal triamcinolone acetonide in silicone oil filled eye using MRI

Poster Presentations - Session 3: anstract no. PS3-4postprin