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71.
Li Chao Brant Eleanor Budak Hikmet Zhang Baohong 《Journal of Zhejiang University. Science. B》2021,22(4):253-284
Since it was first recognized in bacteria and archaea as a mechanism for innate viral immunity in the early 2010 s,clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas) has rapidly been developed into a robust, multifunctional genome editing tool with many uses. Following the discovery of the initial CRISPR/Cas-based system, the technology has been advanced to facilitate a multitude of different functions. These include development as a base editor, prime editor, epigenetic editor, and CRISPR interference(CRISPRi) and CRISPR activator(CRISPRa) gene regulators. It can also be used for chromatin and RNA targeting and imaging. Its applications have proved revolutionary across numerous biological fields, especially in biomedical and agricultural improvement. As a diagnostic tool, CRISPR has been developed to aid the detection and screening of both human and plant diseases, and has even been applied during the current coronavirus disease 2019(COVID-19) pandemic. CRISPR/Cas is also being trialed as a new form of gene therapy for treating various human diseases, including cancers, and has aided drug development. In terms of agricultural breeding, precise targeting of biological pathways via CRISPR/Cas has been key to regulating molecular biosynthesis and allowing modification of proteins, starch, oil, and other functional components for crop improvement. Adding to this, CRISPR/Cas has been shown capable of significantly enhancing both plant tolerance to environmental stresses and overall crop yield via the targeting of various agronomically important gene regulators. Looking to the future, increasing the efficiency and precision of CRISPR/Cas delivery systems and limiting off-target activity are two major challenges for wider application of the technology. This review provides an in-depth overview of current CRISPR development, including the advantages and disadvantages of the technology,recent applications, and future considerations. 相似文献
72.
Transitions to becoming a teacher on an initial teacher education and training programme 总被引:1,自引:0,他引:1
This article is based on research with a group of one‐year Postgraduate Certificate in Education secondary trainee teachers during their initial teacher education and training in England. It considers tensions between trainees’ prior experiences and conceptions of teaching and their training programme. In doing so, it seeks to examine how a trainee’s dispositions as revealed through practice in various contexts are reflective of Bourdieu’s ‘habitus’. Associated with this, the paper also examines how particular forms of pre‐existing cultural capital and manifestations of biographical identity also pre‐dispose trainees to form affinities and disaffinities within particular fields. Lacanian concepts of the symbolic, imaginary and real are used to help explain how trainee teachers articulate resonance and dissonance during their field experiences, particularly in relation to ontological concerns of securing a professional stable sense of self. 相似文献
73.
Colby Hall Garrett J. Roberts Eunsoo Cho Lisa V. McCulley Megan Carroll Sharon Vaughn 《Educational Psychology Review》2017,29(4):763-794
This meta-analysis synthesizes the last two decades of experimental and quasi-experimental research on reading instruction across academic contexts (e.g., social studies, science, mathematics, English language arts) for English learners (ELs) in grades 4 through 8, to determine (a) the overall effectiveness of reading instruction for upper elementary and middle school students who are ELs and (b) how the magnitude of the effect varies based on student, instructional, and study characteristics. The analysis included a total of 11 studies with 46 individual effect sizes and yielded a mean effect size of g?=?0.35 across all (i.e., standardized and unstandardized) reading measures, g?=?0.01 across standardized reading measures, and g?=?0.43 across unstandardized reading measures. For all reading, unstandardized reading, all vocabulary, and unstandardized vocabulary measures, results suggest that higher quality studies tended to have smaller effects, and these effects were even more evident for unstandardized measures (i.e., one unit increase in study quality was associated with decreased effects: g?=?0.21, g?=?0.30, g?=?0.24, g?=?0.30, respectively). For all comprehension measures, effects were larger for instruction that included both vocabulary and comprehension (g?=?0.39) than for instruction that focused on vocabulary alone (g?=?0.08). Results suggest the benefit of developing and refining high-impact approaches to reading instruction for ELs that can be delivered across content areas and grades. 相似文献
74.
In Experiment 1, rats were trained to leverpress on a variable ratio (VR) 30 schedule with a 500-msec delay between the reinforced response and food delivery. Subjects that experienced a signal during the delay responded faster than did control subjects that received the stimulus un-correlated with reinforcement. Higher response rates were obtained when the stimulus used to signal reinforcement was auditory rather than visual. Experiments 2 and 3 compared the effects of signaling reinforcement with either a localized or a diffuse light on responding maintained by VR schedules of reinforcement. Elevated response rates were observed with the diffuse stimulus, but the localized stimulus failed to produce such potentiation. Experiment 3 also examined the conditioned reinforcing power of localized and diffuse visual stimuli. These results are discussed with reference to (1) theories of selective association and sign tracking and (2) their implications for current theories of signaling reinforcement. 相似文献
75.
A paired-associate memory task with pictures and words as items was used to categorize fourth graders into four learner types: HH, high picture-high word; HL, high picture-low word; LH, low picture-high word; LL, low picture-low word. Some children in each classification read prose passages with picture adjunct aids; other children read the passages without adjunct aids. Although free recall for the prose passage yielded inconclusive data, a constructed response test for facts in the prose passages revealed significant Aptitude × Treatment interactions, such that poor paired-associate learners (i.e., LLs) profited more than did good paired-associate learners (i.e., HHs) from picture aids on the prose task. The children's standardized reading scores were positively related to memory performance, but good and poor readers did not differ in their ability to profit from picture aids. It was suggested that less-strategic learners, such as those who perform poorly on paired-associate tasks, are more likely to be helped by externally provided mediational aids, while more-strategic learners are more likely to be helped by instructions to generate their own mediational aids. 相似文献
76.
77.
Hall Jacob A. Lei Jing Wang Qiu 《Educational technology research and development : ETR & D》2020,68(6):3115-3142
Educational technology research and development - The flipped approach has been widely adopted in higher education, yet its theoretical framework and use in teacher preparation courses have been... 相似文献
78.
Dianne J. Hall Casey G. Cegielski James N. Wade 《Decision Sciences Journal of Innovative Education》2006,4(2):237-257
The research described in this article reports the results of a study designed to evaluate the relationship among object‐oriented (OO) computer programming task performance and a student's (1) theoretical value belief, (2) cognitive ability, and (3) personality. The results of this study do not support the assertion that cognitive ability is a main determinant of performance. Rather, the findings suggest that characteristics of an individual nature have more effect on a student's performance. This supports our belief advanced herein that theoretical value belief and personality are significant predictors of computer programming performance in OO environments. From the findings of this study, we assert that academicians who must teach OO computer programming consider these factors when developing course materials or student assistance programs. 相似文献
79.
80.
Linda Watson Graeme Douglas Liz Hodges Mike McLinden Nigel Hall 《Journal of Research in Special Educational Needs》2004,4(2):82-90
There have been many efforts to conceptualise literacy, both in terms of its essence and component parts, but it has proved difficult to define. This paper considers work that is undertaken with children and older learners with sensory needs in order to promote the early stages of literacy. Recent government initiatives aimed at fostering literacy development have caused teachers of children with sensory needs to re-examine their practice. The paper discusses early literacy as part of children's attempts to communicate and describes children with sensory needs engaging in a range of activities that are termed 'literacy' by those working with them. By taking into account these activities, the authors endeavour to throw light on the broader questions around concepts of literacy. 相似文献