Syntactic awareness of Cantonese-speaking children

The development of metalinguistic awareness, and specifically syntactic awareness, (here measured by age-related changes in the ability to judge and revise unacceptable sentences), reflects developmental changes in focus from semantic to syntactic properties of sentences. Previous research reported that children find judgements of word-order changes easier than morphological violations (Hakes, 1980). We hypothesized that this difference in ease of judgement is linked to the language under investigation. That is, there may be a relationship between the functional load of grammatical morphemes and ability to detect syntactic violations. This study investigated the development of syntactic awareness in Cantonese-speaking children. Fifty-six subjects from four age groups (three, five, seven and 20 years old) were asked to judge the grammaticality of 40 sentences (18 with word-order changes and 22 with morphological violations) and correct the grammatically deviant sentences. There was a significant age effect on subjects’ performance in both judgement and revision tasks. Children scored significantly higher in judging sentences with word order changes than those with morphological violations. They also scored higher on word order revisions than morphological revisions, an unexpected finding. The success of correcting morphological violations varied by morphological marker, apparently according to each marker's degree of obligatory use in the language. It would seem then that syntactic awareness is very much affected by language-specific characteristics.published_or_final_versio

Improving file distribution performance by grouping in peer-to-peer networks

It has been shown that the peer-to-peer paradigm is more efficient than the traditional client-server model for file sharing among a large number of users. Given a group of leechers who wants to download a single file and a group of seeds who possesses the whole file, the minimum time needed for distributing the file to all users can be calculated based on their bandwidth availabilities. A scheduling algorithm has been developed so that every leecher can obtain the file within this minimum time. Unfortunately, this mechanism is not optimal with regard to the average download time among the peers. In this paper, we study how to reduce the average download time without prolonging the time needed for all leechers to obtain the file from a theoretical perspective. Based on the bandwidth capacities, the seeds and leechers are divided into different groups. We identify the necessary conditions for grouping to bring about benefits. We also study the impact on performance when leechers leave the system before the downloading process is complete. To evaluate our mechanism, we conduct extensive simulations and compare the performance with a BitTorrentlike file sharing algorithm. The results show that our grouping protocol successfully reduces the average download time over a wide range of system configurations. © 2009 IEEE.published_or_final_versio

Novel bandwidth strategy for wireless P2P file sharing

With the rapid development of the mobile device technology and wireless network technology, the need of an efficient file sharing method on wireless network becomes more and more significant. Peer-to-Peer(P2P) file distribution, as a quite popular method being used now, is a promising choice. However, the limitation of bandwidth of wireless networks greatly restricts the performance of wireless P2P. In this paper, we propose a new idea of better utilizing the limited bandwidth to improve the file distribution performance. The criteria of an optimal splitting of the half-duplex bandwidth is deduced with mathematical analysis. To achieve a further improvement on the average distribution time, we also propose a grouping strategy which works with the bandwidth strategy. Simulation results show that our mechanism can efficiently reduce the file distribution time among wireless peers. © 2011 IEEE.published_or_final_versionThe 2011 IEEE Wireless Communications and Networking Conference (WCNC), Cancun, Mexico, 28-31 March 2011. In IEEE Wireless Communications and Networking Conference Proceedings, 2011, p. 2161-216

A novel grouping strategy for reducing average distribution time in P2P file sharing

Peer-to-Peer(P2P) file distribution has been widely used for file sharing in recent years. When compared with the traditional client-server model, the P2P model is a lot more efficient as each user can act as both a client and a server. This enables the P2P file distribution to scale well with increasing number of users. Grouping strategy has been introduced to reduce the average distribution time among peers without prolonging the total time needed to obtain a file. In this paper, a novel grouping strategy which groups peers of similar bandwidth together is introduced. We mathematically illustrate that under certain circumstances, this new grouping strategy performs better than the Greedy Grouping mechanism. To understand the performance of our grouping mechanism more comprehensively, we conduct extensive simulations. The results show that our mechanism can enhance the performance significantly in different network settings. ©2010 IEEE.published_or_final_versionThe 2010 IEEE International Conference on Communications (ICC), Cape Town, South Africa, 1-5 May 2010. In IEEE International Conference on Communications, 201

Recognizing true H5N1 infections in humans during confirmed outbreaks.

INTRODUCTION: The goal of this study was to evaluate whether any characteristics that are evident at presentation for urgent medical attention could be used to differentiate cases of H5N1 in the absence of viral testing. METHODOLOGY: Information about exposure to poultry, clinical signs and symptoms, treatments, and outcomes was abstracted from existing data in the global avian influenza registry (www.avianfluregistry.org) using standardized data collection tools for documented and possible cases of H5N1 infection who presented for medical attention between 2005-2011 during known H5N1 outbreaks in Azerbaijan, Indonesia, Pakistan and Turkey. RESULTS: Demography, exposure to poultry, and presenting symptoms were compared, with only the common symptoms of fever and headache presenting significantly more frequently in confirmed H5N1 cases than in possible cases. Reported exposure to  infected humans was also more common in confirmed cases. In contrast, unexplained respiratory illness, sore throat, excess sputum production, and rhinorrhea were more frequent in possible cases. Overall, oseltamivir treatment showed a survival benefit, with the greatest benefit shown in H5N1 cases who were treated within two days of symptom onset (51% reduction in case fatality). CONCLUSION: Since prompt treatment with antivirals conferred a strong survival benefit for H5N1 cases, presumptive antiviral treatment should be considered for all possible cases presenting during an outbreak of H5N1 as a potentially life-saving measure

Randomised, double-blind, placebo-controlled study investigating the effects of inorganic nitrate on vascular function, platelet reactivity and restenosis in stable angina: protocol of the NITRATE-OCT study

KSR and this work are funded by an NIHR Doctoral Fellowship (DRF-2014-07-008

Phase I-II clinical trial assessing safety and efficacy of umbilical cord blood mononuclear cell transplant therapy of chronic complete spinal cord injury

published_or_final_versionCreative Commons: Attribution 3.0 Hong Kong Licens

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

The Cytotoxic Necrotizing Factor of Yersinia pseudotuberculosis (CNFy) is Carried on Extracellular Membrane Vesicles to Host Cells

In this study we show Yersinia pseudotuberculosis secretes membrane vesicles (MVs) that contain different proteins and virulence factors depending on the strain. Although MVs from Y. pseudotuberculosis YPIII and ATCC 29833 had many proteins in common (68.8% of all the proteins identified), those located in the outer membrane fraction differed significantly. For instance, the MVs from Y. pseudotuberculosis YPIII harbored numerous Yersinia outer proteins (Yops) while they were absent in the ATCC 29833 MVs. Another virulence factor found solely in the YPIII MVs was the cytotoxic necrotizing factor (CNFy), a toxin that leads to multinucleation of host cells. The ability of YPIII MVs to transport this toxin and its activity to host cells was verified using HeLa cells, which responded in a dose-dependent manner; nearly 70% of the culture was multinucleated after addition of 5 mu g/ml of the purified YPIII MVs. In contrast, less than 10% were multinucleated when the ATCC 29833 MVs were added. Semi-quantification of CNFy within the YPIII MVs found this toxin is present at concentrations of 5 -10 ng per mu g of total MV protein, a concentration that accounts for the cellular responses see