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81.
With the availability of the whole genome sequence of Escherichia coli or Corynebacterium glutamicum, strategies for directed DNA manipulation have developed rapidly. DNA manipulation plays an important role in understanding the function of genes and in constructing novel engineering bacteria according to requirement. DNA manipulation involves modifying the autologous genes and expressing the heterogenous genes. Two alternative approaches, using electroporation linear DNA or recombinant suicide plasmid, allow a wide variety of DNA manipulation. However, the over-expression of the desired gene is generally executed via plasmid-mediation. The current review summarizes the common strategies used for genetically modifying E. coli and C. glutamicum genomes, and discusses the technical problem of multi-layered DNA manipulation. Strategies for gene over-expression via integrating into genome are proposed. This review is intended to be an accessible introduction to DNA manipulation within the bacterial genome for novices and a source of the latest experimental information for experienced investigators. 相似文献
82.
Jie Yuan Sarah Carr Guosheng Ding Shimin Fu John Xuexin Zhang 《Reading and writing》2017,30(3):631-651
Prolonged inspection of a Chinese character induces a feeling of uncertainty of the character, a phenomenon named as Orthographic Satiation. However, there has not been direct evidence showing that such satiation does occur at the orthographic level. To investigate whether Chinese satiation occurs at the orthographic level or at other levels, the present study applies a speeded repetition priming paradigm to Chinese, which has been successfully used to examine Semantic Satiation in English. When judging whether a category name matched an exemplar word, participants showed gradually slower responses as the character standing for the category name was repeated, indicating the occurrence of satiation. However, repetition of a character without accessing its meaning, or repeated access to its meaning without repeating the character itself, did not elicit satiation. The results suggest Orthographic Satiation occurs not at the orthographic level, but at a level associating orthography and meaning during Chinese character reading. 相似文献
83.
Using data from the New Immigrant Survey, a study based on a nationally representative sample of legal immigrants, the present study extends prior research on the academic outcomes of immigrants' children by examining the roles of pre- and postmigration parental characteristics and the home environment. An analysis of 2,147 children aged 6-12 shows that parents' premigration education is more strongly associated with children's academic achievement than any other pre- or postmigration attribute. Premigration parental attributes account for the test score disadvantage of Mexican-origin children of legal immigrants, relative to their non-Latino counterparts. The findings reveal continuities and discontinuities in parental socioeconomic status and demonstrate that what parents bring to the United States and their experiences after arrival influence children's academic achievement. 相似文献
84.
Supplemental instruction classes have been shown in many studies to enhance performance in the supported courses and even to improve graduation rates. Generally, there has been little evidence of a differential impact on students from different ethnic/racial backgrounds. At San Francisco State University, however, supplemental instruction in the Introductory Biology I class is associated with even more dramatic gains among students from underrepresented minority populations than the gains found among their peers. These gains do not seem to be the product of better students availing themselves of supplemental instruction or other outside factors. The Introductory Biology I class consists of a team-taught lecture component, taught in a large lecture classroom, and a laboratory component where students participate in smaller lab sections. Students are expected to master an understanding of basic concepts, content, and vocabulary in biology as well as gain laboratory investigation skills and experience applying scientific methodology. In this context, supplemental instruction classes are cooperative learning environments where students participate in learning activities that complement the course material, focusing on student misconceptions and difficulties, construction of a scaffolded knowledge base, applications involving problem solving, and articulation of constructs with peers. 相似文献
85.
Aisi LI 《Frontiers of Education in China》2014,9(2):188-210
The foundation of Shanxi University is a prime example of the collaborative efforts in higher education between the Chinese and British in late Qing China (1842–1912). Both sides made compromises, with the Chinese adapting their ideas of educational sovereignty, and the British agreeing to work under the supervision of the local government. Such a collaboration was made possible by the individual personalities of the two founders and their visions for China’s higher education. The dual structure of the university, with one department to teach Chinese learning and the other to teach Western learning, showed that, at a local and personal level, these officials and missionaries opted for direct cooperation, despite the myriad changes and upheavals following the Boxer Movement. In addition, by allowing foreign missionaries into critical roles in a government university, the principle of ti-yong dualism was gradually being adapted. The formation of Shanxi University not only demonstrates the dynamics of the Sino-Western educational relationship and the roles individuals played in it, but also stimulates reflection on China’s contemporary cross-border partnerships in higher education 相似文献
86.
87.
The first large-scale, nationwide academic achievement testing program using Stanford Achievement Test (Stanford) for deaf and hard-of-hearing children in the United States started in 1969. Over the past three decades, the Stanford has served as a benchmark in the field of deaf education for assessing student academic achievement. However, the validity and reliability of using the Stanford for this special student population still require extensive scrutiny. Recent shifts in educational policy environment, which require that schools enable all children to achieve proficiency through accountability testing, warrants a close examination of the adequacy and relevance of the current large-scale testing of deaf and hard-of-hearing students. This study has three objectives: (a) it will summarize the historical data over the last three decades to indicate trends in academic achievement for this special population, (b) it will analyze the current federal laws and regulations related to educational testing and special education, thereby identifying gaps between policy and practice in the field, especially identifying the limitations of current testing programs in assessing what deaf and hard-of-hearing students know, and (c) it will offer some insights and suggestions for future testing programs for deaf and hard-of-hearing students. 相似文献
88.
89.
Thinking aloud together: A teacher’s semiotic mediation of a whole-class conversation about percents
How does classroom interaction support students’ apprenticeship into the ways of speaking, writing, and diagramming that constitute the practice of mathematics? We address this problem through an interpretative analysis of a whole-group conversation about alternative ways of solving a problem involving percent discounts that occurred in a sixth grade classroom. This research study draws upon Dewey’s theory of inquiry, Vygotsky’s cultural–historical psychology, Freudenthal’s realistic mathematics education, and Halliday’s systemic functional linguistics (SFL). From Freudenthal, we borrow the notions of mathematizing and guided reinvention—the former notion offers a view of mathematics as an activity of structuring subject matter and the latter one provides insights into the processes whereby mathematizing is learned and taught in the classroom. We glean from Dewey his view of reflective thinking as inquiry and the role that conversations may serve therein. We rely upon Vygotsky’s notions of a verbal thinking plane and a social phase of learning in order to reconsider the function of whole-class interaction in apprenticing students into mathematizing. Finally, SFL provides us with tools for explaining the choices of grammar and vocabulary students and teachers make as they realize meanings in whole-group conversations. Treating the selected whole-class conversation as a text, we focus our analysis on how this text came to mean what it did. Our central questions are as follows: What meanings were realized in the whole-class conversation by teacher and students and how were these meanings realized? How did the teacher’s lexico-grammatical choices guide the students’ choices? In addressing these questions, we advance an interpretation of the conversation as paradigmatic of students and teacher thinking aloud together about percents. 相似文献