The Application of Conceptual Metaphor in English Vocabulary Teaching

As the basic unit of expression, vocabulary is the foundation of English and is closely related to students’ overall language ability. However, many teachers tend to teach English vocabulary in traditional way, simply listing words with little attention to context in daily instruction. As a result, students mechanically memorize words without understanding the connotation and extension of words, which frequently leads to misunderstandings in vocabulary comprehension and inflexible vocabulary application. To solve this problem, this study considers cognitive linguistics as the guide to exploring vocabulary teaching based on conceptual metaphor. Following the definition, mechanism, and classification of conceptual metaphor, it makes an overview of both the international and Chinese studies concerning the application of conceptual metaphor in English vocabulary teaching, and finds that the lack of empirical research, the small sample size, the short time of experiment, the uncomprehensive research results and students’ different ability to accept this teaching method remain to be further solved. This contributes to the existing problems in vocabulary teaching and cultivating students’ competence in cognitive acquisition

Analysis of the Aerodynamic Character of Bionic Wingspan on the Basis of Frigate Wing Structure

This paper extracts the frigate bird’s leading edge contour by CATIA on the basis of the obverse and side pictures when frigate bird glides. Then three bionic wingspans of bending update, forward and integrating the two are built combining NACA 4412 airfoil. Compared with simple wingspan, the drag force of testing wingspan can be suppressed significantly, because the wingspan bending forward can form airflow of S style which declines the slope of the path-line of airflow and reduces the leading edge’s pressures. As a result the working condition is improved because the bending forward wingspan reduces air’s velocity. The lift efficiency of bending update wingspan may be improved because of increasing the leading edge’s pressure resulting in high speed airflow. Key words: leading edge contour; bionic wingspans; NACA 4412; aerodynamic performanc

An miR-200 Cluster on Chromosome 23 Regulates Sperm Motility in Zebrafish

Besides its well-documented roles in cell proliferation, apoptosis, and carcinogenesis, the function of the p53-microRNA axis has been recently revealed in the reproductive system. Recent studies indicated that miR-200 family members are dysregulated in nonobstructive azoospermia patients, whereas their functions remain poorly documented. The aim of this study was to investigate the function of the miR-200 family on zebrafish testis development and sperm activity. There was no substantial difference in testis morphology and histology between wild-type (WT) and knockout zebrafish with deletion of miR-200 cluster on chromosome 6 (chr6-miR-200-KO) or on chromosome 23 (chr23-miR-200-KO). Interestingly, compared with WT zebrafish, the chr6-miR-200-KO zebrafish had no difference on sperm motility, whereas chr23-miR-200-KO zebrafish showed significantly improved sperm motility. Consistently, ectopic expression of miR-429a, miR-200a, and miR-200b, which are located in the miR-200 cluster on chromosome 23, significantly reduced motility traits of sperm. Several sperm motility-related genes, such as amh, wt1a, and srd5a2b have been confirmed as direct targets of miR-200s on chr23. 17a-ethynylestradiol (EE2) exposure resulted in upregulated expression of p53 and miR-429a in testis and impairment of sperm motility. Strikingly, in p53 mutant zebrafish testis, the expression levels of miR-200s on chr23 were significantly reduced and accompanied by a stimulation of sperm motility. Moreover, the upregulation of miR-429a associated with EE2 treatment was abolished in testis with p53 mutation. And the impairment of sperm activity by EE2 treatment was also eliminated when p53 was mutated. Together, our results reveal that miR-200 cluster on chromosome 23 controls sperm motility in a p53-dependent manner.</p