The (Un)Changing Role of Mandarin Chinese in Language Education in Hong Kong

With the impending change of status of Hong Kong from a British colony to an integral partof the People's Republic of China (PRC)on 1 July 1997,the future role of Putonghua (Mandarin), which is the national language of the PRC, has been widely debated. In particular,teachers,educationalists and policy-makers are interested to know whatwill happen within the education system in Hong Kong. Since an overwhelming majority of the population are Southern Chinese in origin, Cantonese is used as a lingua franca in society and as a major medium of instruction at primary level and in the secondary schools which promote mother-tongue teaching. With the expansion of higher education, the use of Cantonese in lectures and seminars in universities is now becoming common. This paper reports on the status and use of the two Chinese varieties, i.e. Cantonese and Putonghua in education in Hong Kong, analyses the increasing economic links and social interaction between Hong Kong and the PRC, and discusses various proposals concerning the (un)changing role of Mandarin in the post-1997 education context.published_or_final_versio

Retroperitoneal schwannoma: A common tumour in an uncommon site

We describe a female adult patient who presented with acute retention of urine and vague abdominal discomfort. A provisional diagnosis of ovarian tumour was made after crosssectional imaging. At laparotomy a very large retroperitoneal mass was biopsied and found to be a schwannoma after pathological examination. The clinical, radiological, and pathological features of this disease are discussed in this report.published_or_final_versio

DNA methylation of microRNA genes in multiple myeloma

DNA methylation is one of the heritable epigenetic modifications, leading to repressed gene expressions and consequent phenotypic alterations without changing the DNA sequence. MicroRNA (miRNA) is a novel class of short non-coding RNA molecules regulating a wide range of cellular functions through translational repression of their target genes. Recently, epigenetic dysregulation of tumor-suppressor miRNA genes by promoter DNA methylation has been implicated in human cancers, including multiple myeloma (MM). This article presents a brief overview of the pathogenesis of MM, the role of DNA methylation in cancer biology, methods of DNA methylation analysis, miRNA biology and dysregulation of miRNAs in MM and summaries the current data on the role of DNA methylation of tumor-suppressive miRNAs in MM.postprin

Testing for double threshold autoregressive conditional heteroscedastic model

The testing problem for the hypothesis of linearity against the double threshold autoregressive conditional heteroscedastic model is addressed. The, problem is nonstandard as the threshold parameter is a nuisance parameter which is absent under the null hypothesis. We will show that the asymptotic null distribution of the Lagrange-multiplier test statistic is a functional of a zero-mean Gaussian process. In some cases, we give the upper percentage points of the test statistic. The performance of the test statistic is illustrated by extensive simulation experiments and an example.published_or_final_versio

Perceived oral health condition and self-satisfaction with oral health

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Outcome measures of chronic arthritis in Hong Kong: comparison of the AIMS2 (Chinese) and WHO quality of life - brief form (WHOQOL-BREF) (HK)

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Methylation of TET2, CBL and CEBPA in Ph-negative myeloproliferative neoplasms

A loss-of-function mutation of TET2, CBL and CEBPA has been implicated in the pathogenesis or leukaemic transformation of myeloproliferative neoplasm. As tumour suppressor genes may potentially be inactivated by promoter hypermethylation, the authors studied the methylation status of these genes in three cell lines and diagnostic marrow samples from 45 patients with myeloproliferative neoplasm (MPN) (essential thrombocythaemia, N=34; polycythaemia vera, N=7 and primary myelofibrosis, N=4) by methylation-specific PCR. TET2 was heterozygously methylated in MEG-01 and K562 but completely unmethylated in HEL. On the other hand, both CBL and CEBPA were completely unmethylated in all three cell lines. In the primary marrow samples, methylation of TET2 occurred in two (5.9%) patients with essential thrombocythaemia (4.4% of all patients), both without JAK2 V617 mutation, but not in polycythaemia vera or primary myelofibrosis. There was no association between TET2 methylation with the type of MPN (p=0.713). Hypermethylation of CBL or CEBPA was not detected in any patients. In summary, methylation of TET2, CBL and CEBPA is infrequent in MPN at diagnosis. The role of methylation of these genes at the time of leukaemic transformation warrants further study.published_or_final_versio

Cost-effective approaches for high-resolution bioimaging by time-stretched confocal microscopy at 1um

Session: Optics Imaging Algorithms and Analysis IIOptical imaging based on time-stretch process has recently been proven as a powerful tool for delivering ultra-high frame rate (< 1MHz) which is not achievable by the conventional image sensors. Together with the capability of optical image amplification for overcoming the trade-off between detection sensitivity and speed, this new imaging modality is particularly valuable in high-throughput biomedical diagnostic practice, e.g. imaging flow cytometry. The ultra-high frame rate in time-stretch imaging is attained by two key enabling elements: dispersive fiber providing the time-stretch process via group-velocity-dispersion (GVD), and electronic digitizer. It is well-known that many biophotonic applications favor the spectral window of 1μm. However, reasonably high GVD (< 0.1 ns/nm) in this range can only be achieved by using specialty single-mode fiber (SMF) at 1μm. Moreover, the ultrafast detection has to rely on the state-of- the-art digitizer with significantly wide-bandwidth and high sampling rate (e.g. <10 GHz, <40 GS/s). These stringent requirements imply the prohibitively high-cost of the system and hinder its practical use in biomedical diagnostics. We here demonstrate two cost-effective approaches for realizing time-stretch confocal microscopy at 1μm: (i) using the standard telecommunication SMF (e.g. SMF28) to act as a few-mode fiber (FMF) at 1μm for the time-stretch process, and (ii) implementing the pixel super-resolution (SR) algorithm to restore the high-resolution (HR) image when using a lower-bandwidth digitizer. By using a FMF (with a GVD of 0.15ns/nm) and a modified pixel-SR algorithm, we can achieve time-stretch confocal microscopy at 1μm with cellular resolution ( 3μm) at a frame rate 1 MHz.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.published_or_final_versio

Fabrication of Photovoltaic Cell From Rhenium Containing Polymer

Photovoltaic devices were fabricated using rhenium bis(arylimino) acenaphthene (DIAN) complex containing poly(p-phenylenevinylene). These polymers absorb strongly in the visible region at ca. 440-550 nm. In addition, this type of transition metal based polymers have been shown to exhibit large photo-sensitivity due to the presence of the rhenium complex, which has a relatively long-lived Metal-to-Ligand Charge Transfer (MLCT) character. By using this type of polymers, the metal content can be adjusted easily by simply changing the monomer feed ratio. Moreover, the excited state properties and electronic absorption properties can be modified by varying the structure of the diimine ligand coordinated to the metal. This approach allows us to fine-tune the absorption spectra of the polymers by employing different types of rhenium complex derivatives. PEDOT:PSS and PTCDI were used as the hole and electron transport layers, respectively. The ITO/PEDOT:PSS/DIAN-PPV/PTCDI/Al devices were found to exhibit photovoltaic response under the illumination of AMI solar radiation. The short-circuit current ISC, open-circuit voltage V OC, and the fill factor FF were measured to be 38 μA/cm 2, 0.93 V and 0.21 respectively. Another photovoltaic device was prepared with the structure ITO/PEDOT:PSS/DIAN-PPV:TiO2/PTCDI/Al and its photovoltaic properties were studied. The presence of TiO2 will assist the electron transport of the DIAN-PPV to the PTCDI, in which the electrons can be collected at the aluminium electrode. The short-circuit current ISC open-circuit voltage VOC, and the fill factor FF were measured to be 51 μA/cm2, 1.18 V and 0.12 respectively. It was observed that the power conversion efficiency of photovoltaic devices related closely to the rhenium content and the structure of the rhenium complex used.published_or_final_versio

Methylation of miR-34a, miR-34b/c, miR-124-1 and miR-203 in Ph-negative myeloproliferative neoplasms

BACKGROUND: MicroRNA (miR) miR-34a, -34b/c, -124-1 and -203 are tumor suppressor miRs implicated in carcinogenesis. METHODS: We studied DNA methylation of these miRs in Philadelphia-negative (Ph-ve) myeloproliferative neoplasms (MPNs). Methylation-specific PCR (MSP), verified by direct sequencing of the methylated MSP products, was performed in cell lines, normal controls and diagnostic marrow samples of patients with MPNs. RESULTS: Methylation of these miRs was absent in the normal controls. miR-34b/c were homozygously methylated in HEL cells but heterozygously in MEG-01. In HEL cells, homozygous miR-34b/c methylation was associated with miR silencing, and 5-aza-2'-deoxycytidine treatment led to re-expression of both miR-34b and miR-34c, consistent with that both miRs are under the regulation of the same promoter CpG island. miR-34a was heterozygously methylated in MEG-01 and K-562. miR-203 was completely unmethylated in K-562 and SET-2 but no MSP amplification was found in both HEL and MEG-01, suggestive of miR deletion. In primary samples, four each had miR-34b/c and -203 methylation, in which two had concomitant methylation of miR-34b/c and -203. miR-34a was methylated in one patient and none had methylation of miR-124-1. Seven patients (15.6%) had methylation of at least one of the four miRs. miR methylation did not correlate with clinical parameters, disease complications or JAK2 V617F mutation. CONCLUSION: This is the first report of miR hypermethylation in MPNs. miR-203 hypermethylation is not specific to Ph+ve leukemias but also present in Ph-ve MPNs. miR-34b/c methylation was associated with reversible miR silencing. There was no correlation of miR methylation with clinical demographic data or outcome.published_or_final_versio