School effectiveness in East Asia: Concepts, origins and implications

Identifies several features in East Asian schools which coincide with commonly recognized characteristics of effective schools in the Western literature: community support, teacher professionalism, attention to quality and high expectations. Attributes this to the East Asian culture and discusses three major dimensions of the East Asian culture: the individual-community dimension, the effort-ability dichotomy and the holistic-analytic tendency in analyses. Traces the origin of such cultural dimensions in the ancient literature and explores the implications of such cultural dimensions in school management. Briefly highlights two major challenges to the adoption of an effective schooling system in East Asia.published_or_final_versio

CFD study of dynamic wind actions on faces of a tall building

Section B: Numerical simulation and theoretical analysisThe article can be viewed at: http://wgy091.ust.hk:8080/document/HKWE1papers.pdfThis paper computes and investigates the fluctuating wind forces on different building faces of a 6:1:1 square-section tall building with LES. Time histories of aerodynamic forces on building faces are computed from which power spectra and cross correlation analysis are made. The computation results are compared to past wind tunnel data from base balance and wind pressure measurements. Most results show qualitative agreement.published_or_final_versio

Economic impact of political barriers to cross-border acquisitions: An empirical study of CNOOC's unsuccessful takeover of Unocal

In 2005, the US Congress challenged the acquisition by CNOOC (a Chinese state-owned enterprise) of Unocal (a US firm). This challenge creates a political barrier for foreign companies to acquire US oil companies. This paper examines the stock price reaction of US oil companies to this political opposition. Using an event study methodology, we find that this political barrier resulted in a substantial decline in the market value of US oil companies. For a period of 44 days, during which six anti-CNOOC-takeover political events occurred, the cumulative decline in the market value of a portfolio of 13 US oil refining firms was $47.5 billion and that of a portfolio of 66 US oil and gas exploration firms was$11.4 billion. This study is the first to analyze and quantify the stock price reaction of US non-merging firms to political barriers to cross-border acquisitions. It also has a policy implication regarding the recent enactment of the Foreign Investment and National Security Act of 2007. © 2009 Elsevier B.V. All rights reserved.postprin

Dynamic wind loading of H-shaped tall buildings

Fulltext in: http://www.iawe.org/Proceedings/7APCWE/M3A_5.pdfTechnical Session: M3-A High-Rise Building, no.5Dynamic wind loads on a number of H-shaped tall buildings are measured in the wind tunnel with a highfrequency force balance for all wind incidences. The aim is to investigate the size effect of the recessed cavities on the dynamic wind loading behavior of the building. Combinations of three widths and three depths of a cavity are tested. It is found that at most wind incidences, the presence of cavities on the building faces leads to little modifications to the magnitudes and behavior of mean and fluctuating overturning moment coefficients. However, reduced magnitudes of across-wind moment fluctuations are found at normal incidence and different behavior of across-wind excitation is revealed by the across-wind moment spectra. Wind torsion is noticeably modified by the presence of the recessed cavities.link_to_subscribed_fulltex

Miniaturized Via-Free Magneto-Electric Dipole Antenna Fed by Substrate Integrated Coaxial Line on Reactive Impedance Surface

A wideband via-free magneto-electric (ME) dipole antenna is conceived for millimeter wave band applications. Herein, the electric dipole patch and a half-wavelength radiating slot are excited in phase on the patch layer by a substrate integrated coaxial line (SICL) to fulfill the complementary conditions as a ME dipole. The proposed antenna omits the deployment of the vertically oriented shorted patch, which relieves the typical quarter-wavelength height constraint and fabrication complexity of the conventional ME dipole antennas. The antenna is further loaded with the capacitive reactive impedance surface (RIS) to achieve size miniaturization and bandwidth enhancement. The finalized dimension (excluding the RIS) is 0.36 λ0 × 0.48 λ0 × 0.13 λ0, where λ0 denotes the wavelength in free-space at the center frequency. A wide impedance bandwidth of 64.8% (17.1 GHz - 33.5 GHz) is achieved for SWR ≤ 2, in which the antenna gain varies from 5.9 dBi to 8.8 dBi. Besides, a consistent unidirectional radiation pattern can be observed across the operating frequency band. In the sequel, the same antenna is aggregated into an 8-element linear array which is fed by a designated 8-way SICL network. Finally, an active simulation has been performed to verify the ability of the array in beam scanning

Miniaturized Via-Free Magneto-Electric Dipole Antenna Fed by Substrate Integrated Coaxial Line on Reactive Impedance Surface

A wideband via-free magneto-electric (ME) dipole antenna is conceived for millimeter wave band applications. Herein, the electric dipole patch and a half-wavelength radiating slot are excited in phase on the patch layer by a substrate integrated coaxial line (SICL) to fulfill the complementary conditions as a ME dipole. The proposed antenna omits the deployment of the vertically oriented shorted patch, which relieves the typical quarter-wavelength height constraint and fabrication complexity of the conventional ME dipole antennas. The antenna is further loaded with the capacitive reactive impedance surface (RIS) to achieve size miniaturization and bandwidth enhancement. The finalized dimension (excluding the RIS) is 0.36 λ0 × 0.48 λ0 × 0.13 λ0, where λ0 denotes the wavelength in free-space at the center frequency. A wide impedance bandwidth of 64.8% (17.1 GHz - 33.5 GHz) is achieved for SWR ≤ 2, in which the antenna gain varies from 5.9 dBi to 8.8 dBi. Besides, a consistent unidirectional radiation pattern can be observed across the operating frequency band. In the sequel, the same antenna is aggregated into an 8-element linear array which is fed by a designated 8-way SICL network

Ultrastructural studies of Massarina ingoldiana and M. purpurascens

Ascus and ascospore appendage structures can be important characters in delineation of genera. We have therefore examined the ascus and ascospore ultrastructure of Massarina ingoldiana and M. purpurascens, as Massarina is thought to be a heterogeneous genus. The ascus wall of M. ingoldiana is two layered and comparable to M. thalassiae. Ascospores of both species comprise an electron-transparent mesosporium, an electron-dense episporium and an exosporial mucilaginous sheath. In this respect they are similar to the ultrastructure of other Massarina species, and should be maintained in Massarina.published_or_final_versio

Optical studies of ZnS:Mn films grown by pulsed laser deposition

Author name used in this publication: C. L. MakAuthor name used in this publication: K. H. Wong2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Patients with Helicobacter pylori positive and negative duodenal ulcers have distinct clinical characteristics

Aim: To assess the clinical characteristics of Helicobacter pylori (H pylori) negative duodenal ulcer. Methods: Patients with an endoscopic diagnosis of duodenal ulcer between 1996 and 2002 were included in the present study. Patients were considered to be negative for H pylori, if both histological examination and rapid urease test of biopsy specimens were negative. A comparison was made between patients with H pylori positive and negative duodenal ulcers. Results: A total of 1 343 patients were studied. Their mean age was 54.7±0.5 years. There was a male preponderance (M:F = 2.5:1). Three hundred and ninety-eight patients (29.6%) did not have H pylori infection. The annual proportion of patients with H pylori negative duodenal ulcers increased progressively from 1996 to 2002. On multivariate analysis, patients with H pylori negative duodenal ulcer were more likely to be older, have concomitant medical problem, pre-existing malignancy, recent surgery, underlying sepsis, or taken non-steroidal anti-inflammatory drugs. In terms of clinical presentations, patients with H pylori negative duodenal ulcer were more likely to present with bleeding, multiple ulcers and larger ulcers. Conclusion: The proportion of patients with H pylori negative duodenal ulcers is on the rise because of a continued drop in incidence of H pylori positive duodenal ulcers in recent years. Such patients have distinct clinical characteristics and it is important to ascertain the H pylori status before starting eradication therapy. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

A novel p70 S6 kinase-microRNA biogenesis axis mediates multicellular spheroid formation in ovarian cancer progression

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