462 research outputs found

    English language education at Guangxi University, China:challenges, responses and recommendations

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    This study is concerned with the growing expectation of the quality of English language education in China’s universities under the pressure of globalization as well as a developing Chinese society. Since the 1980s, four national curricula for English language education at universities have been introduced by the Chinese Ministry of Education, causing an unprecedented “English craze” in China’s higher education and other areas of its society. However, despite the heavy investment in terms of capital and facilities, the quality of English language education has become a pressing problem in higher education as well as in Chinese society. The aim of the research is to explore what the challenges and resolutions are in improving English language education at Guangxi University, China. The research project draws insight from a mixed methods approach underpinned by interpretivism and the research design is a case study. The data were collected through interviews with the university administrative staff, teaching staff and students, questionnaires with teachers and students, and documentary reading. The study found that administrative staff, teaching staff, and students at Guangxi University are currently confronted by wide variety of challenges as a result of the pressures coming from three hierarchical levels, namely, the global, national and institutional levels. The findings suggest that among the various challenges the most prominent ones involve teachers’ lack of career development training, lack of information on ongoing reform, different priorities by stakeholders in College English evaluation and students’ desires being mostly overlooked. Based on the research data, the study indicates remedial strategies in four domains: administration, course design, teacher career development and learning support. With regard to its contribution to the literature, by providing an illuminative case study within a global context, the research describes various responsive strategies taken at national and institutional levels, contributing to the developing body of theory on globalization in China’s higher education. The study offers diverse and different views III and experiences about English language education at the university level, which also contributes to the research tradition of language teaching in higher education. In this sense, the study has implications for theory, practice and future research in language teaching under a global context in higher education. Key words: English language education; interpretivism; a mixed methods approach; challenges; response

    The stochastic lot-sizing problem with quantity discounts

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    This paper addresses the stochastic lot-sizing problem with quantity discounts. In particular, we examine the uncapacitated finite-period economic lot-sizing problem in which the parameters in each period are random and discrete. When an order is placed, a fixed cost is incurred and an all-unit quantity discount is awarded based on the quantity ordered. The lead time is zero and the order is delivered immediately. First we study the case with overstocks by which the excess inventory incurs a holding cost. The objective in this case is to minimize the expected total cost including ordering and holding costs. The stochastic dynamics is modeled with a scenario tree. We characterize properties of the optimal policy and propose a polynomial time algorithm with complexity O ( n 3 ) for single discount level, where n is the number of nodes in the scenario tree. We extend the results to cases allowing stockout and multi-discount levels. Numerical experiments are conducted to evaluate the performance of the algorithm and to gain the man- agement insights

    Tumour Suppressor Function of RNase L in A Mouse Model

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    RNase L is one of the key enzymes involved in the molecular mechanisms of interferon (IFN) actions. Upon binding with its activator, 5′-phosphorylated, 2′-5′ oligoadenylates (2-5A), RNase L plays an important role in the antiviral and anti-proliferative functions of IFN, and exerts proapoptotic activity independent of IFN. In this study, we have found that RNase L retards proliferation in an IFN-dependent and independent fashion. To directly measure the effect of RNase L on tumour growth in the absence of other IFN-induced proteins, human RNase L cDNA was stably expressed in P-57 cells, an aggressive mouse fibrosarcoma cell line. Three clonal cell lines were isolated in which the overexpression of RNase L was 15–20-fold of the endogenous level. Groups of five nude mice were injected subcutaneously with either the human RNase L overexpressing clones (P-RL) or control cells transfected with an empty vector (P-Vec). Tumour growth by the two cell lines was monitored by measuring tumour volumes. In the P-RL group, tumour formation was significantly delayed and the tumours grew much slower compared to the control group. Morphologically, the P-RL tumour appeared to have more polygonal cells and increased single cell tumour necrosis. Interestingly, P-RL tumours eventually started to grow. Further analysis revealed, however, that these tumours no longer expressed ectopic RNase L. Our findings suggest that RNase L plays a critical role in the inhibition of fibrosarcoma growth in nude mice

    Validity and reliability of questionnaires measuring physical activity self-efficacy, enjoyment, social support among Hong Kong Chinese children

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    AbstractBackgroundPhysical activity (PA) correlates have not been extensively studied in Hong Kong children.ObjectiveThe aim of this study is to assess the validity and reliability of translated scales to measure PA related self-efficacy, enjoyment and social support in Hong Kong Chinese children.MethodsSample 1 (n=273, aged 8–12years) was recruited (May–June, 2013) from two primary schools. Confirmatory factor analyses (CFA) were conducted to assess factorial validity. Criterion validity was assessed by correlating measured constructs with self-reported PA. Cronbach's alpha was computed to assess scale internal consistency. The intraclass correlation coefficient (ICC) was performed to assess scale test–retest reliability. Criterion validity was further examined in Sample 2 (n=84, aged 8–12years) from a third school by correlating measured constructs with objectively measured PA collected in September 2013 and February 2014.ResultsThe CFA results supported the one-factor structure of the scales. All PA correlates were significantly (p<0.01) associated with self-reported PA in Sample 1. Self-efficacy and enjoyment were significantly (p<0.05) correlated with objectively measured PA in Sample 2. All the scales demonstrated acceptable internal consistency. All ICC values of the scales suggested acceptable test–retest reliability.ConclusionThe results provide psychometric support for using the scales to measure PA correlates among Hong Kong Chinese children

    Cell-free Circulating miRNA Biomarkers in Cancer.

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    Considerable attention and an enormous amount of resources have been dedicated to cancer biomarker discovery and validation. However, there are still a limited number of useful biomarkers available for clinical use. An ideal biomarker should be easily assayed with minimally invasive medical procedures but possess high sensitivity and specificity. Commonly used circulating biomarkers are proteins in serum, most of which require labor-intensive analysis hindered by low sensitivity in early tumor detection. Since the deregulation of microRNA (miRNA) is associated with cancer development and progression, profiling of circulating miRNAs has been used in a number of studies to identify novel minimally invasive miRNA biomarkers. In this review, we discuss the origin of the circulating cell-free miRNAs and their carriers in blood. We summarize the clinical use and function of potentially promising miRNA biomarkers in a variety of different cancers, along with their downstream target genes in tumor initiation and development. Additionally, we analyze some technical challenges in applying miRNA biomarkers to clinical practice

    Recognition of specific sialoglycan structures by oral streptococci impacts the severity of endocardial infection.

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    Streptococcus gordonii and Streptococcus sanguinis are primary colonizers of the tooth surface. Although generally non-pathogenic in the oral environment, they are a frequent cause of infective endocarditis. Both streptococcal species express a serine-rich repeat surface adhesin that mediates attachment to sialylated glycans on mucin-like glycoproteins, but the specific sialoglycan structures recognized can vary from strain to strain. Previous studies have shown that sialoglycan binding is clearly important for aortic valve infections caused by some S. gordonii, but this process did not contribute to the virulence of a strain of S. sanguinis. However, these streptococci can bind to different subsets of sialoglycan structures. Here we generated isogenic strains of S. gordonii that differ only in the type and range of sialoglycan structures to which they adhere and examined whether this rendered them more or less virulent in a rat model of endocarditis. The findings indicate that the recognition of specific sialoglycans can either enhance or diminish pathogenicity. Binding to sialyllactosamine reduces the initial colonization of mechanically-damaged aortic valves, whereas binding to the closely-related trisaccharide sialyl T-antigen promotes higher bacterial densities in valve tissue 72 hours later. A surprising finding was that the initial attachment of streptococci to aortic valves was inversely proportional to the affinity of each strain for platelets, suggesting that binding to platelets circulating in the blood may divert bacteria away from the endocardial surface. Importantly, we found that human and rat platelet GPIbα (the major receptor for S. gordonii and S. sanguinis on platelets) display similar O-glycan structures, comprised mainly of a di-sialylated core 2 hexasaccharide, although the rat GPIbα has a more heterogenous composition of modified sialic acids. The combined results suggest that streptococcal interaction with a minor O-glycan on GPIbα may be more important than the over-all affinity for GPIbα for pathogenic effects

    Mediator complex component MED13 regulates zygotic genome activation and is required for postimplantation development in the mouse

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    Understanding factors that regulate zygotic genome activation (ZGA) is critical for determining how cells are reprogrammed to become totipotent or pluripotent. There is limited information regarding how this process occurs physiologically in early mammalian embryos. Here, we identify a mediator complex subunit, MED13, as translated during mouse oocyte maturation and transcribed early from the zygotic genome. Knockdown and conditional knockout approaches demonstrate that MED13 is essential for ZGA in the mouse, in part by regulating expression of the embryo-specific chromatin remodeling complex, esBAF. The role of MED13 in ZGA is mediated in part by interactions with E2F transcription factors. In addition to MED13, its paralog, MED13L, is required for successful preimplantation embryo development. MED13L partially compensates for loss of MED13 function in preimplantation knockout embryos, but postimplantation development is not rescued by MED13L. Our data demonstrate an essential role for MED13 in supporting chromatin reprogramming and directed transcription of essential genes during ZGA.Fil: Miao, Yi Liang. National Institutes of Health; Estados UnidosFil: Gambini, Andres. National Institutes of Health; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zhang, Yingpei. National Institutes of Health; Estados UnidosFil: Padilla Banks, Elizabeth. National Institutes of Health; Estados UnidosFil: Jefferson, Wendy N.. National Institutes of Health; Estados UnidosFil: Bernhardt, Miranda L.. National Institutes of Health; Estados UnidosFil: Huang, Weichun. National Institutes of Health; Estados UnidosFil: Li, Leping. National Institutes of Health; Estados UnidosFil: Williams, Carmen J.. National Institutes of Health; Estados Unido

    Differential gene expression in the nucleus accumbens with ethanol self-administration in inbred alcohol-preferring rats

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    The current study examined the effects of operant ethanol (EtOH) self-administration on gene expression in the nucleus accumbens (ACB) and amygdala (AMYG) of inbred alcohol-preferring (iP) rats. Rats self-trained on a standard two-lever operant paradigm to administer either water-water, EtOH (15% v/v)-water, or saccharin (SAC; 0.0125% g/v)-water. Animals were killed 24 hr after the last operant session, and the ACB and AMYG dissected; RNA was extracted and purified for microarray analysis. For the ACB, there were 513 significant differences at the p < 0.01 level in named genes: 55 between SAC and water; 215 between EtOH and water, and 243 between EtOH and SAC. In the case of the AMYG (p < 0.01), there were 48 between SAC and water, 23 between EtOH and water, and 63 between EtOH and SAC group. Gene Ontology (GO) analysis indicated that differences in the ACB between the EtOH and SAC groups could be grouped into 15 significant (p < 0.05) categories, which included major categories such as synaptic transmission, cell and ion homeostasis, and neurogenesis, whereas differences between the EtOH and water groups had only 4 categories, which also included homeostasis and synaptic transmission. Several genes were in common between the EtOH and both the SAC and water groups in the synaptic transmission (e.g., Cav2, Nrxn, Gabrb2, Gad1, Homer1) and homeostasis (S100b, Prkca, Ftl1) categories. Overall, the results suggest that changes in gene expression in the ACB of iP rats are associated with the reinforcing effects of EtOH

    Feasibility of low-intensity psychological interventions for emotional and behavioural difficulties in children and young people with genetic conditions: a case series

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    Background: Children with genetic conditions may experience significant mental health difficulties such as anxiety and challenging behaviour. However, understanding of the feasibility and effectiveness of psychological interventions for emotional and behavioural problems in the context of genetic conditions is limited. Low-intensity psychological interventions have demonstrated promise in paediatric populations and may be able to address their mental health difficulties. / Method: A case series design was used to assess the feasibility of low-intensity interventions for emotional and behavioural difficulties in children and young people with genetic conditions recruited from a mental health drop-in centre at a tertiary hospital. Participants received seven weekly sessions with a trained practitioner. The intervention was based on existing modular treatments and evidence-based self-help materials. Feasibility and treatment satisfaction were assessed, as well as measures of symptoms of anxiety and challenging behaviour, treatment goals, and quality of life, at baseline, during treatment, and six-month follow-up. / Results: Five participants received treatment for challenging behaviour, one for anxiety, and one for obsessive compulsive disorder. All participants completed treatment. Clinically significant change in the SDQ Total score was found in three participants. All participants demonstrated progress in goals and symptoms of emotional and behavioural difficulties over the course of treatment. / Conclusions: Low-intensity psychological interventions for emotional and behavioural difficulties in children and young people with genetic conditions is feasible, acceptable, and potentially beneficial. Further research is warranted to examine the effectiveness of the intervention and its use in clinical paediatric settings
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