1,307 research outputs found

    Designing CALL for learning Chinese characters

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    Despite the enormity of its quantity, printed or written forms of Chinese characters are composed from a limited number of common components. For example, the characters for pond( ), lake( ), stream( ), river ( ), sea( ) and ocean( ) all contain a component in common, a three-dot component representing water. When this clue is explicitly highlighted to students, the learning of Chinese characters can be greatly enhanced. Using a computer to help students to develop this kind of structural awareness about language learning has not yet been thoroughly examined. This paper reports on the design of CALL software based on a pedagogic method which helps students to develop the higher order skills to analyse and categorise Chinese characters by using components. The result of the classroom experiment has shown supportive evidence on the feasibility and the need of integrating the software with an affective and contextual way of teaching Chinese characters.postprin

    Roles of endothelin-1 in beta-amyloid-induced neurotoxicity in hippocampus: an implication for Alzheimer’s pathology

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    Poster F - Nervous System Disorders: abstract no. P3-F-012The British Neuroscience Association’s Festival of NeuroscienceAlzheimer’s disease (AD) is an incurable neurodegenerative disorder. Abnormal levels of endothelin-1 (ET-1) have been demonstrated in parietal white matter(1), cerebral cortex and vessels of the AD brain(2). Neuronal death and accumulation of beta-amyloid (Aβ) are prominent pathological features of AD. Significant neuronal death is found in Aβ-treated primary neurons and Aβ-overexpressing mouse models(3,4). ET-1 is a known vasoconstrictor and neuro-active peptide. ET-1 induces apoptosis in primary retinal neurons(5). In contrary, ET-receptor (ETR) type B agonist can rescue neurons from Aβ-induced apoptosis(6). These findings suggest ET-1 plays dual roles in neurodegeneration and neuroprotection, respectively. This study aims to investigate the effect of ET-1 on Aβ-induced cell death in hippocampal neurons. Primary hippocampal neurons were pretreated with or without ETR antagonists prior to the treatment of oligomeric form of Aβ1-42, ET-1 or both on 14 DIV. Cell viability was measured by MTT assay. Changes in protein expression in apoptotic and ET-1 signaling pathways were assessed by western-blot analysis. This study shed light on the roles of ET-1 in Aβ1-42-neurotoxicity, building upon which the ET-1 signaling pathway as a potential therapeutic target for AD can be further investigated.published_or_final_versio

    Searching (the) FIRST radio arcs near ACO clusters

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    Gravitational lensing (GL) of distant radio sources by galaxy clusters should produce radio arc(let)s. We extracted radio sources from the FIRST survey near Abell cluster cores and found their radio position angles to be uniformly distributed with respect to the cluster centres. This result holds even when we restrict the sample to the richest or most centrally condensed clusters, and to sources with high S/N and large axial ratio. Our failure to detect GL with statistical methods may be due to poor cluster centre positions. We did not find convincing candidates for arcs either. Our result agrees with theoretical estimates predicting that surveys much deeper than FIRST are required to detect the effect. This is in apparent conflict with the detection of such an effect claimed by Bagchi & Kapahi (1995).Comment: 6 pages; 8 figures and 1 style file are included; to appear in Proc. "Observational Cosmology with the New Radio Surveys", eds. M. Bremer, N. Jackson & I. Perez-Fournon, Kluwer Acad. Pres

    Opioid therapy for chronic non-cancer pain: guidelines for Hong Kong

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    Clinical correlation of nuclear survivin in esophageal squamous cell carcinoma

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    To examine the correlation of survivin (both total and nuclear survivin) with clinicopathological parameters of esophageal squamous cell carcinoma (ESCC) patients. Tumors and non-tumor tissues near the proximal resection margins were resected from ESCC patients undergone esophagectomy. Quantitative polymerase chain reaction (qPCR) was performed to detect survivin mRNA expression level in the 10 paired tumor and adjacent non-tumor tissues. To confirm with the clinical situation, survivin mRNA and protein expression were measured by qPCR and immunoblot, respectively, in 5 ESCC cell lines and a non-neoplastic esophageal epithelial cell line. Immunohistochemistry was employed to reveal the cellular localization of survivin in tumor tissues isolated from the 64 ESCC patients undergone surgery alone. Up-regulation of survivin mRNA and protein was found in 5 ESCC lines (HKESC-1, HKESC-2, HKESC-3, HKESC-4, and SLMT-1) when compared to a non-neoplastic esophageal epithelial cell line NE-1. In particular, HKESC-3, HKESC-4, and SLMT-1 cells demonstrated ~50-fold increase in survivin mRNA. High level of survivin mRNA in tumor tissues when compared to non-tumor tissues was found in 70 % (7 of 10) of clinical cases. The increase in expression ranged from ~twofold to ~16-fold. Immunohistochemistry results showed that survivin was found at the cell nuclei in all specimens examined. Nuclear expression of survivin was inversely associated with the likelihood of developing nodal metastasis (p = 0.021) and significantly associated with early-stage ESCC (p = 0.039). Nuclear survivin could serve as a marker for indicating disease status in ESCC patients. © 2012 The Author(s).published_or_final_versio

    Role of miR-338-5p as a novel modulator of chemoresistannce in esophageal cancer

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    Conference Theme: Anticancer Drug Action and Drug Resistance: from Cancer Biology to the ClinicINTRODUCTION: Multimodal treatment incorporating surgical resection and the use of chemotherapeutic drugs is commonly used in the management of esophageal cancer. However, resistance to chemotherapy drugs may contribute to poor treatment outcome and cancer recurrence. Increasing evidence suggests that miRNAs regulate the sensitivity of cancer to chemotherapeutic drugs. 5-Fluorouracil (5-FU) is an antimetabolite agent ...postprin

    Properties of Blood, Porphyrins, and Exposure to Legacy and Emerging Persistent Organic Pollutants in Surf Scoters (Melanitta perspicillata) Overwintering on the South Coast of British Columbia, Canada

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    The surf scoter (Melanitta perspicillata) is a little-studied species of North American sea duck. Estimates suggest it has experienced a precipitous decline in breeding numbers over the latter half of the past century. To investigate the potential role of contaminant uptake and toxicity in the population decline, this study undertook to measure blood chemistry, porphyrin concentrations, EROD, and organic contaminants in mature surf scoters wintering in the Strait of Georgia, BC, Canada. Hepatic organochlorine pesticide, polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofuran, polychlorinated biphenyl (PCB), polybrominated diphenyl ether, and nonylphenol concentrations were relatively low; for example, ΣTEQs (toxic equivalents) for PCBs, dioxins, and furans combined ranged from 4.7 ng/kg wet weight in reference-site (Baynes Sound) birds to 11.4 ng/kg wet weight in birds from Vancouver Harbour. Nonetheless, elevated EROD activity indicated that birds in Howe Sound were responding to an Ah-receptor-mediated stressor, which was also affecting hematocrit values and possibly vitamin A status. In addition, a low proportion of lymphocytes in individuals across locations in early spring samples was associated with poor body condition. The apparent loss of fitness just prior to the onset of northerly migrations to breeding grounds is of particular concern. Compromised health of mature birds at this point in the season might impact negatively on the productivity and survival of some individuals, particularly those overwintering in Howe Sound

    SHH1, a Homeodomain Protein Required for DNA Methylation, As Well As RDR2, RDM4, and Chromatin Remodeling Factors, Associate with RNA Polymerase IV

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    DNA methylation is an evolutionarily conserved epigenetic modification that is critical for gene silencing and the maintenance of genome integrity. In Arabidopsis thaliana, the de novo DNA methyltransferase, DOMAINS REARRANGED METHYLTRANSFERASE 2 (DRM2), is targeted to specific genomic loci by 24 nt small interfering RNAs (siRNAs) through a pathway termed RNA–directed DNA methylation (RdDM). Biogenesis of the targeting siRNAs is thought to be initiated by the activity of the plant-specific RNA polymerase IV (Pol-IV). However, the mechanism through which Pol-IV is targeted to specific genomic loci and whether factors other than the core Pol-IV machinery are required for Pol-IV activity remain unknown. Through the affinity purification of NUCLEAR RNA POLYMERASE D1 (NRPD1), the largest subunit of the Pol-IV polymerase, we found that several previously identified RdDM components co-purify with Pol-IV, namely RNA–DEPENDENT RNA POLYMERASE 2 (RDR2), CLASSY1 (CLSY1), and RNA–DIRECTED DNA METHYLATION 4 (RDM4), suggesting that the upstream siRNA generating portion of the RdDM pathway may be more physically coupled than previously envisioned. A homeodomain protein, SAWADEE HOMEODOMAIN HOMOLOG 1 (SHH1), was also found to co-purify with NRPD1; and we demonstrate that SHH1 is required for de novo and maintenance DNA methylation, as well as for the accumulation of siRNAs at specific loci, confirming it is a bonafide component of the RdDM pathway
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