Using corpora to develop learners’ collocational competence

This article investigates the role of direct corpus use in learners’ collocational competence in academic writing. An experiment was conducted between two groups of Chinese postgraduates who had no previous knowledge of corpora. It was embedded in a regular 4-month linguistics course in the students’ programmes, where a corpus-assisted method was used for the experimental group and a traditional, or rule-based, method was used for the control group. The English essays written by these two groups of learners from different time periods (before, immediately after, and two months after the course) were analysed regarding the learners’ collocational use—in particular, verb-preposition collocations. The results reveal that while both groups showed improvements in their academic writing, the students in the experimental group displayed a significant improvement in the use of collocations, including a higher rate of accuracy, or naturalness, and an increased use of academic collocations and fixed phraseological items. It is thus concluded that the knowledge and use of corpora can help students raise their awareness of habitual collocational use and develop their collocational competence. This supports the positive role of direct corpus application in an EFL context

A corpus-based study of the high frequency nouns 'time' and 'thing': Investigating the role of phraseology in the construction of meaning in discourse

The current study investigates the phraseological behaviour of two high frequency nouns, $time$ and $thing$, and aims to explore the role of phraseology in the construction of meaning in discourse and how phraseology is represented in English teaching in China. The term “phraseology” in this study refers to both the form of lexical or lexicogrammatical co-occurrence (e.g. collocations, lexicalised phrases, patterns and frames) and their usage (e.g. syntagmatic, semantic, pragmatic and textual features). The results show that there is a close relationship between phraseology and phenomena such as polysemy, metaphor, evaluation and vagueness which are important to the construction of meaning. These phenomena are largely exhibited by phraseological items rather than single words. The current study argues that phraseology rather than individual words should be considered as the primary unit of meaning in discourse. The results suggest that phraseology can serve a disambiguating role both at the ‘lexical’ level (e.g. different senses of a ‘polysemous’ word or phrase) and at the ‘discourse’ level. For instance, different metaphorical or evaluative meanings can be identified by examining the use of phraseological items associated with these meanings. This study also shows that the representation of phraseology in English teaching in China is still problematic in terms of the selection and presentation of phraseological items, and recommends that more attention be paid to the treatment of phraseology in teaching and that corpus evidence should be used to inform the design of future pedagogic materials in China

Development of trinucleotide (GGC)n SSR markers in peanut ( Arachis hypogaea L.)

Cultivated peanut ( Arachis hypogaea L.) is an oilseed crop of economic importance. It is native to South America, and it is grown extensively in the semi-arid tropics of Asia, Africa, and Latin America. Given an extremely narrow genetic base, efforts are being made to develop simple sequence repeat (SSR) markers to provide useful genetic and genomic tools for the peanut research community. A SSR-enriched library to isolate trinucleotide (GGC)n SSRs in peanut was constructed. A total of 143 unique sequences containing (GGC)n repeats were identified. One hundred thirty eight primer pairs were successfully designed at the flanking regions of SSRs. A suitable polymerase was chosen to amplify these GC-rich sequences. Although a low level of polymorphism was observed in cultivated peanut by these new developed SSRs, a high level of transferability to wild species would be beneficial to increasing the number of SSRs in wild species

An effective method for cloning of partial MADS-box genes related to flower development in groundnut

Based on the most conserved region of the MADS box, a pair of degenerate primers were designed and used to amplify the genomic DNA of groundnut (cv. JL 24). The results indicate that an amplified fragment, related to flower development, showed a high homology to the MADS-box protein of Arabidopsis thaliana. This study laid the foundation for obtaining the full length of the MADS-box gene in groundnu

Detection of Candida DNA in peritoneal fluids by PCR assay optimizing the diagnosis and treatment for intra-abdominal candidiasis in high-risk ICU patients: A prospective cohort study

BackgroundIntra-abdominal candidiasis (IAC) is the predominant type of invasive candidiasis with high mortality in critically ill patients. This study aimed to investigate whether the polymerase chain reaction (PCR) assay for detecting Candida DNA in peritoneal fluids (PF) is useful in diagnosing and management of IAC in high-risk patients in intensive care unit (ICU).MethodsA prospective single-center cohort study of surgical patients at high risk for IAC was conducted in the ICU. PF was collected from the abdominal drainage tubes (within 24 h) or by percutaneous puncture. Direct PF smear microscopy, PF culture, blood culture, and serum (1–3)-β-D-glucan were performed in all patients. For Candida PCR assay, the ITS1/ITS4 primers that targeted the ITS1-5.8 s-ITS2 regions were used for PCR, and sequencing analysis was used to identify the pathogen at the species level. IAC was defined according to the 2013 European consensus criteria.ResultsAmong 83 patients at high risk for IAC, the IAC criteria were present in 17 (20.5%). The sensitivity and specificity of the Candida PCR assay were 64.7 and 89.4%, respectively, and the area under the receiver operating characteristic curve was 0.77 (95% CI: 0.63–0.91). In this cohort, the positive predictive value and negative predictive value were 90.8% (95% CI: 80.3–96.2%) and 61.1% (95% CI: 36.1–81.7%), respectively. Diagnostic consistency was moderate (kappa 0.529, p < 0.001) according to the 2013 European consensus criteria.ConclusionDetection of Candida DNA in PF using PCR can be considered an adjunct to existing routine diagnostic tools which may optimize the diagnosis and antifungal treatment of IAC in high-risk patients in the ICU

A Stochastic Simulation Analysis Of The Effects Of Indian Wheat Production Instability On The World Wheat Market

Adverse weather factors in India augment the instability in wheat supply and trade. Consequently, India's wheat trade is a classic example of stochastic supply being the dominant factor in determining trade flows. This study analyses the effects of random fluctuations in India's wheat supply on domestic and world price variability and trade flows of India and major exporters and importers by using stochastic simulation analysis. Production instability causes price variability of $71 per metric ton under autarky condition. However, price variability is mitigated once trade is allowed. Thus, trade acts as a buffer stock program in reducing price variability. The results show that production shortfalls (surpluses) in India benefit wheat exporters (importers) and hurt importers (exporters)