21 research outputs found
Data-driven learning of collocations by Chinese learners of English:a longitudinal perspective
Collocations, a crucial component of language competence, remain a challenge for L2 learners across all proficiency levels. While the data-driven learning (DDL) approach has shown great potential for collocation learning from a shorter-term perspective, this study investigates its effectiveness in the long term, examining both linguistic gains and changes in learners’ confidence about which words collocate. The effect of DDL was compared with learning collocations using a corpus-based collocations dictionary and non-corpus-based tools. Learners’ experience with the tools was also explored through a questionnaire. The study employed a quasi-experimental research design with 100 Chinese learners of English as participants in two experimental groups and a control group. A novel corpus tool, #LancsBox (Brezina et al., Citation2015), was used in the DDL approach to identify and visualise collocations. The results showed that the learners in the DDL group increased their collocation knowledge at the end of the treatment and retained the gains three months later. The learners also reported a significant increase in their confidence about which words collocate. Both changes were found to be more substantial than the effects of using the corpus-based collocations dictionary or other tools. As for their experience, learners reported satisfaction with using corpora in their writing and, importantly, continued with corpus consultation three months after the end of the intervention. The findings have implications for integrating corpus consultation into learning practice both inside and outside of the classroom, showing that with sufficient training, DDL can provide an effective method to learn complex linguistic features such as collocations
A Mutation in Intracellular Loop 4 Affects the Drug-Efflux Activity of the Yeast Multidrug Resistance ABC Transporter Pdr5p
Multidrug resistance protein Pdr5p is a yeast ATP-binding cassette (ABC) transporter in the plasma membrane. It confers multidrug resistance by active efflux of intracellular drugs. However, the highly polymorphic Pdr5p from clinical strain YJM789 loses its ability to expel azole and cyclohexmide. To investigate the role of amino acid changes in this functional change, PDR5 chimeras were constructed by segmental replacement of homologous BY4741 PDR5 fragments. Functions of PDR5 chimeras were evaluated by fluconazole and cycloheximide resistance assays. Their expression, ATPase activity, and efflux efficiency for other substrates were also analyzed. Using multiple lines of evidence, we show that an alanine-to-methionine mutation at position 1352 located in the predicted short intracellular loop 4 significantly contributes to the observed transport deficiency. The degree of impairment is likely correlated to the size of the mutant residue
Evaluating the effect of data-driven learning (DDL) on the acquisition of academic collocations by Chinese learners of English
Collocations, prefabricated multi-word combinations, are considered to be a crucial component of language competence which indicates the central role they should play in language teaching and learning (e.g., Nesselhauf, 2005). However, collocations remain a challenge to L2 learners at different proficiency levels, present a particular difficulty to Chinese learners of English (cf. Granger & Bestgen, 2014). Corpora, as a valuable source of reliable information about language, are a potentially useful source of evidence in language pedagogy. The pedagogical applications of corpora can be realised through direct corpus-based data-driven learning (DDL). Although DDL represents an approach that has been argued to offer an effective teaching method for the acquisition of academic collocations and hence may be beneficial to learners (e.g., Nesseulhauf, 2005), a DDL approach has so far not become a mainstream teaching practice and it is mostly conducted through activities based on either hands-on or paper-based concordance line; this highlights the need to explore the effect of using new corpus tools, beyond simple concordancing (Vyatkina & Boulton, 2017). This study, therefore, investigates the effectiveness of DDL by using a new corpus tool, #LancsBox (Brezina, McEnery & Wattam, 2015). This study used data from 100 Chinese students of English from a Chinese university and employed a quasiexperimental method, using a pre-test-and-post-test (including a delayed test) controlgroup research design to compare the achievement of the use of DDL and a corpus- based collocations dictionary with a control group in teaching academic collocations to the Chinese EFL learners. Results showed that the DDL approach was effective in improving Chinese EFL learners’ both receptive and productive knowledge of collocations. Learners’ attitudes indicated that the majority of learners were satisfied with using the DDL approach in collocation learning while writing and believed corpus consultation, particularly by means of the concordances and collocation network, was very useful in collocations learning both receptively and productively. The findings suggested using corpus tool could facilitate learners’ collocations learning. They also contribute to the potential application of corpora and the new corpus tool into mainstream language learning classroom and providing guidance and materials for teachers wishing to implement the method in collocations learning
HuR Uses AUF1 as a Cofactor To Promote p16INK4 mRNA Decayâ–ż
In this study, we show that HuR destabilizes p16INK4 mRNA. Although the knockdown of HuR or AUF1 increased p16 expression, concomitant AUF1 and HuR knockdown had a much weaker effect. The knockdown of Ago2, a component of the RNA-induced silencing complex (RISC), stabilized p16 mRNA. The knockdown of HuR diminished the association of the p16 3′ untranslated region (3′UTR) with AUF1 and vice versa. While the knockdown of HuR or AUF1 reduced the association of Ago2 with the p16 3′UTR, Ago2 knockdown had no influence on HuR or AUF1 binding to the p16 3′UTR. The use of EGFP-p16 chimeric reporter transcripts revealed that p16 mRNA decay depended on a stem-loop structure present in the p16 3′UTR, as HuR and AUF1 destabilized EGFP-derived chimeric transcripts bearing wild-type sequences but not transcripts with mutations in the stem-loop structure. In senescent and HuR-silenced IDH4 human diploid fibroblasts, the EGFP-p16 3′UTR transcript was more stable. Our results suggest that HuR destabilizes p16 mRNA by recruiting the RISC, an effect that depends on the secondary structure of the p16 3′UTR and requires AUF1 as a cofactor
OTUD5 cooperates with TRIM25 in transcriptional regulation and tumor progression via deubiquitination activity
The mechanisms by which deubiquitinases modulate tumour progression are not fully understood. Here, the authors perform an RNAi screen and identify that the deubiquitinase OTUD5 suppresses cancer growth in a TRIM25 dependent manner, which in turn controls the expression of tumour suppressor protein, PML
Mitochondrial Trafficking and Processing of Telomerase RNA TERC
Summary: Mitochondrial dysfunctions play major roles in many diseases. However, how mitochondrial stresses are relayed to downstream responses remains unclear. Here we show that the RNA component of mammalian telomerase TERC is imported into mitochondria, processed to a shorter form TERC-53, and then exported back to the cytosol. We found that the import is regulated by PNPASE, and the processing is controlled by mitochondrion-localized RNASET2. Cytosolic TERC-53 levels respond to changes in mitochondrial functions but have no direct effect on these functions. These findings uncover a mitochondrial RNA trafficking pathway and provide a potential mechanism for mitochondria to relay their functional states to other cellular compartments. : The functions of most mitochondrial RNAs imported from the cytosol are poorly understood. Cheng et al. provide evidence that the RNA component of mammalian telomerase TERC is imported into mitochondria, processed to a shorter form TERC-53, and then exported back to the cytosol. The cytosolic TERC-53 level serves as a potential indicator of mitochondrial functions. Keywords: mitochondria, RNA, import, export, processing, mitochondrial dysfunction, retrograde signaling, TERC, telomerase, RNASET
Membrane localization of Pdr5p and its mutant variants.
<p>Isolated plasma membranes (15 µg/lane) were electrophoresed on an SDS–8% polyacrylamide gel and visualized with Coomassie blue (top panel). Pdr5p (middle panel) and Pma1p (bottom panel) were immunodetected with specific antibodies as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0029520#s4" target="_blank">materials and methods</a> section. Filled arrowheads indicate Pdr5p and open arrowheads indicate Pma1p. Coomassie blue stained SDS-PAGE gel (upper panel) and western blot (lower panel) of the same strains are shown.</p