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1.
研究目的：提高胞外多糖索拉胶的产量。 创新要点：透明颤菌血红蛋白基因在质粒上表达,不加抗生素发酵生产索拉胶。 研究方法：将透明颤菌血红蛋白基因构建到广谱质粒pCM158上得到重组质粒pCM158-vgb,重组质粒转入土壤杆菌ZX09中,使透明颤菌血红蛋白在土壤杆菌ZX09中表达。 重要结论：在土壤杆菌ZX09中颤菌血红蛋白的表达解决了发酵过程中氧受限的问题,提高了宿主菌的呼吸速率、蔗糖酶活性和黏度,将发酵产物索拉胶的产量提高了30％。  相似文献   

2.
Insect resistance and glyphosate tolerance have been two of the most important traits in the genetic improvement of various crops. In this study, two Bacillus thuringiensis (Bt) insecticidal genes, Cry1Ac and Cry1Ig, and a modified glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene (G10) were combined into a single transferred DNA (T-DNA) fragment and introduced into rice by Agrobacterium-mediated transformation. A transgenic line with single-copy T-DNA insertion named GAI-14 was found to be highly resistant to striped stem borer and rice leaf roller, and tolerant to glyphosate. Analysis of T-DNA border sequence suggested that the transgenes were inserted at the chromosome 3 and appeared to have not interrupted any known or putative genes. A field trial observed no significant difference in the basic agronomic traits between GAI-14 and the recipient rice.  相似文献   

3.
The Agrobacterium-mediated transformation system is the most commonly used method in soybean transformation. Screening of soybean genotypes favorable for Agrobacterium-infection and tissue regeneration is the most important step to establish an efficient genetic transformation system. In this study, twenty soybean genotypes that originated from different soybean production regions in China were screened for transient infection, regeneration capacity, and stable transgenic efficiency. Three genotypes, Yuechun 04-5, Yuechun 03-3, and Tianlong 1, showed comparable stable transgenic efficiencies with that of the previously reported American genotypes Williams 82 and Jack in our experimental system. For the Tianlong 1, the average stable transformation efficiency is 4.59%, higher than that of control genotypes (Jack and Williams 82), which is enough for further genomic research and genetic engineering. While polymerase chain reaction (PCR), LibertyLink strips, and β-glucuronidase (GUS) staining assays were used to detect the insertion and expression of the transgene, leaves painted with 135 mg/L Basta could efficiently identify the transformants.  相似文献   

4.
Although technology for automatic grading of multiple choice exams has existed for several decades, it is not yet as widely available or affordable as it should be. The main reasons preventing this adoption are the cost and the complexity of the setup procedures. In this paper, Eyegrade, a system for automatic grading of multiple choice exams is presented. While most current solutions are based on expensive scanners, Eyegrade offers a truly low-cost solution requiring only a regular off-the-shelf webcam. Additionally, Eyegrade performs both mark recognition as well as optical character recognition of handwritten student identification numbers, which avoids the use of bubbles in the answer sheet. When compared with similar webcam-based systems, the user interface in Eyegrade has been designed to provide a more efficient and error-free data collection procedure. The tool has been validated with a set of experiments that show the ease of use (both setup and operation), the reduction in grading time, and an increase in the reliability of the results when compared with conventional, more expensive systems.  相似文献   

5.
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6.
Self-regulated learning (SRL) has been highlighted as a critical aspect of translation learning. However, past work in translation learning has rarely sought to synthesize translation learning strategies under a self-regulated learning paradigm. Further research would be confined by the paucity of a psychometrically sound instrument to measure learners' self-regulated translation learning strategies. This study aimed to develop a reliable and valid self-regulated translation learning strategy scale (SRTLSS). Based on relevant literature, we hypothesized a hierarchical model and generated items for the SRTLSS. Drawing on the response from 873 Chinese English majors, the validated SRTLSS had 25 items addressing five dimensions: self-control, meaning fulfillment, value and interest, text processing, and retrieving strategies. Results demonstrated the SRTLSS has good measurement validity and reliability with strong invariance across undergraduate and graduate students. The SRTLSS can be used as a complementary tool to diagnose learners' weaknesses and strengths in translation teaching and learning.  相似文献   

7.
Spatial language is the language of spatial concepts and spatial relationships. Prior research has demonstrated an association between spatial language and spatial thinking in pre-school children. However, there is limited evidence exploring age-based differences in spatial language in older childhood. This cross-sectional study has three main aims. First, we present a novel spatial language measure and show differences in spatial language performance across age groups from 6 to 10 years (N = 155). Second, having demonstrated that our measure is sensitive to age-based progression, we use regression analyses to determine relations between spatial language and performance on a range of spatial tasks (r2:1.2%–9.0%). Third, we investigate the relations between spatial language and different mathematics skills (r2:0.2%–15.4%) and propose mechanisms that may explain these associations. We discuss how these findings lay a foundation for future spatial language interventions as a novel tool which may lead to educational improvements in mathematics.  相似文献   

8.
Phenomena associated with the pendulum present numerous opportunities for assessing higher order human capabilities related to scientific inquiry and the discovery of natural law. This paper illustrates how systematic assessment of scientific inquiry capabilities, using pendulum phenomena, can provide a useful tool for classroom teachers and program planners. Structured inquiry, a technique of teacher-facilitated student inquiry involving direct interaction between students and natural phenomena, is presented as a way to establish student competence in applying scientific inquiry capabilities (e.g., conceptualizing variation due to error). This approach to assessment can heighten student curiosity and provide a concrete referent for complementary cultural, historical, and scientific instruction. The role of assessment in constructively shaping science education programs is considered.  相似文献   

9.
Much is known about how to provide safe environments for preschool children (3–5 years-of-age); however, many preschool children still experience preventable injuries—particularly children living in poverty. This study examined the use of an assessment tool used to identify children at risk for unintended injury in two large, federally funded Head Start programs during home visits. Families of preschool children in two multi-center Head Start programs (N = 499 and N = 228) were screened by teachers for risks related to safety in their home and parenting environment during mandatory Head Start home visits in the fall and spring. The safety screening tool was part of an established, broader interview assessment called the Family Map, which was designed to help Head Start programs meet mandatory performance standards related to the identification of risk and strengths in the family. Study results indicated that a large number of preschool children from low-income backgrounds were at risk for a variety of risks related to unintentional injury. Further, in some areas Head Start families increased their safety related parenting behaviors by the second assessment with different areas noted in the two programs. This study demonstrated that, beyond the use of the tool to identify families in need of intervention services, it can be used by childcare providers to effectively monitor family need and for program self-assessment.  相似文献   

10.
Eukaryotic initiation factor subunit c(eIF3c) has been identified as an oncogene that is over-expressed in tumor cells and,therefore,is a potential therapeutic target for gene-based cancer treatment.This study was focused on investigating the effect of small interfering RNA(siRNA)-mediated eIF3c gene knockdown on colon cancer cell survival.The eIF3c gene was observed to be highly expressed in colon cancer cell models.The expression levels of the gene in eIF3c siRNA infected and control siRNA infected cells were compared via real-time polymerase chain reaction(PCR) and western blotting analysis.Cell proliferation levels were analyzed employing 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium bromide(MTT) and colony formation assays.Furthermore,the effects of eIF3c gene knockdown on the cell cycle and apoptosis were analyzed using flow cytometry.The results showed that suppression of eIF3c expression significantly(P<0.001) reduced cell proliferation and colony formation of RKO colon cancer cells.The cell cycle was arrested by decreasing the number of cells entering S phase.Further,apoptosis was induced as a result of eIF3c knockdown.Collectively,eIF3c deletion effectively reduced the survival of colon cancer cells and could be used as a therapeutic tool for colon cancer therapy.  相似文献   

11.
This article presents the design and evaluation of a tool for inspecting conceptual models of system behaviour. The basis for this research is the Garp framework for qualitative simulation. This framework includes modelling primitives, such as entities, quantities and causal dependencies, which are combined into model fragments and scenarios. Given a library of model fragments and a scenario describing an initial situation, the qualitative simulation engine generates predictions in the form of a state–transition graph. This rich knowledge representation has potential for educational purposes. However, communicating the contents of simulation models effectively to learners is not trivial. The predicate logic format used by Garp is not easy for non-experts to understand, and a simulation often contains so much information that it is difficult to get an overview while still having access to detailed information. To address these problems, a tool has been developed that generates graphical representations of the information contained in a qualitative simulation. This tool, named VisiGarp, incorporates a vocabulary of graphical elements for model ingredients and relationships, and combines these into interactive diagrams. VisiGarp has been evaluated by thirty students, with promising results, using a setup which included simulation results and exercises about Brazilian Cerrado ecology.  相似文献   

12.
Since there is an increasing recognition to address the need to move practicing teachers to a higher standard of practice, mentoring or coaching has been receiving increasing attention. A variety of tools has been developed to make these relationships more effective. Work within a recent mentor project indicated current tools were not detailed enough for mentors to provide effective feedback to mentees. This paper presents a more detailed tool and describes categories of pedagogical practices related to an extended inquiry-cycle model. During the course of the project, mentors and mentees also used this tool for adapting existing curriculum to a more standards-based mode of instruction, thus having it function as a planning tool.
Bernard ZubrowskiEmail:
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13.
This paper examines the validity of the Approaches and Study Skills Inventory for Students—short version (ASSIST; Tait et al. in Improving student learning: Improving students as learners, 1998), to be used with Portuguese undergraduate students. The ASSIST was administrated to 566 students, in order to analyse a Portuguese version of this inventory. Exploratory factor analysis (principal axis factor analysis followed by direct oblimin rotation) reproduced the three main factors that correspond to the original dimensions of the inventory (deep, surface apathetic and strategic approaches to learning). The results are consistent with the background theory on approaches to learning. Additionally, the reliability analysis revealed acceptable internal consistency indexes for the main scales and subscales. This inventory might represent a valuable research tool for the assessment of approaches to learning among Portuguese higher education students.  相似文献   

14.
《Learning and Instruction》2007,17(2):123-139
This study investigated the metaphors that prospective teachers in Turkey (N = 1,142) formulated to describe the concept of “teacher”. Participants completed the prompt “A teacher is like… because…” by focusing on only one metaphor to indicate their conceptualization of teaching and learning. Altogether 64 valid personal metaphors were analyzed and 10 main conceptual themes were identified. Significant associations were detected between participants' gender and study program type and six of the conceptual themes. Metaphors seem to provide a powerful cognitive tool in gaining insight into prospective teachers' professional thinking.  相似文献   

15.
When teachers believe that students' abilities are fixed, their students' motivation, well-being, and performance tend to suffer. While many interventions have been developed to reduce these so-called fixed mindsets in students and increase the belief that abilities are malleable (i.e., a growth mindset), there are no cost-effective, scalable interventions targeting teachers' mindsets. To address this need, we developed a brief intervention consisting of a reflection task in which teachers thought and wrote about their mission as educators. Two experiments with preservice teachers (total N = 576) revealed that this brief intervention increased their growth mindsets (meta-analytic d = 0.25). This increase did not dissipate over the course of a week (meta-analytic d = 0.26), suggesting the intervention's effects are not ephemeral. Although more work is needed to establish the robustness and generalizability of this intervention's effects, it may ultimately become a useful tool for teacher education programs.  相似文献   

16.
Abstract

This paper is designed to encourage discussion on two particular approaches to solving two problems concerning the training of staff in small businesses. It describes ‘The Business Analyst’, a ‘do‐it‐yourself training needs analysis tool intended to be used by managers of small businesses. It has also proved to be a powerful negotiating tool between training providers and managers, and a management aid for training institutions. Secondly, the paper describes the present state of development of a hi‐tech approach to the provision of information about training opportunities.  相似文献   

17.
University administrators may invest significant time and resources with the goal of improving their U.S. News & World Report ranking, but the real impact of these investments is not well known since, as other universities make similar changes, rankings become a moving target. This research removes the mystique of the U.S. News ranking process by producing a ranking model that faithfully recreates U.S. News outcomes and quantifies the inherent “noise” in the rankings for all nationally ranked universities. The model developed can be a valuable tool to institutional researchers and university leaders by providing detailed insight into the U.S. News ranking process. It allows the impact of changes to U.S. News subfactors to be studied when variation between universities and within subfactors is present. Numerous simulations were run using this model to understand the effect of each subfactor individually and to determine the amount of change that would be required for a university to improve its rank or move into the top 20. Results show that for a university ranked in the mid-30 s it would take a significant amount of additional resources, directed in a very focused way, to become a top-ranked national university, and that rank changes of up to ± 4 points should be considered “noise”. These results can serve as a basis for frank discussions within a university about the likelihood of significant changes in rank and provide valuable insight when formulating strategic goals.  相似文献   

18.
In this article thought experiments are uncovered as key stimuli of philosophical potential in children’s literature and their presentation and function is examined in a selection of focal texts, including: Lewis Carroll’s Alice’s Adventures in Wonderland (1865) and Through the Looking-Glass (1871); Even the Parrot by Dorothy Sayers (1944); Nina Bawden’s Carrie’s War (1974); and A Game of Soldiers (1985) by Jan Needle. The thought experiment is a device common to science and philosophy and has been recognised as an heuristic tool in literature generally, but here children’s literature is drawn into the conversation, revealing that—as a dynamic mechanism of children’s narrative—thought experiments have a long-standing and particular role to play in books for young people. This paper connects with a recent turn in children’s literature discourse toward the conditions of power in books for young readers; it moves on the debate by demonstrating that the apparatus of thought experimentation places the implied child reader in a position of philosophical responsibility and forward thinking. Presenting thought experiments in different ways, formal properties of the thought experiment—such as conversational mode, double engagement and modal positioning—are identified and shown to open up a philosophical space of subsequence in children’s texts.  相似文献   

19.
This study examined the inclusion of nature of science (NOS) in popular science writing to determine whether it could serve supplementary resource for teaching NOS and to evaluate the accuracy of text mining and classification as a viable research tool in science education research. Four groups of documents published from 2001 to 2010 were analyzed: Scientific American, Discover magazine, winners of the Royal Society Winton Prize for Science Books, and books from NSTA’s list of Outstanding Science Trade Books. Computer analysis categorized passages in the selected documents based on their inclusions of NOS. Human analysis assessed the frequency, context, coverage, and accuracy of the inclusions of NOS within computer identified NOS passages. NOS was rarely addressed in selected document sets but somewhat more frequently addressed in the letters section of the two magazines. This result suggests that readers seem interested in the discussion of NOS-related themes. In the popular science books analyzed, NOS presentations were found more likely to be aggregated in the beginning and the end of the book, rather than scattered throughout. The most commonly addressed NOS elements in the analyzed documents are science and society and empiricism in science. Only one inaccurate presentation of NOS were identified in all analyzed documents. The text mining technique demonstrated exciting performance, which invites more applications of the technique to analyze other aspects of science textbooks, popular science writing, or other materials involved in science teaching and learning.  相似文献   

20.
Monitoring the quality of teaching practices of primary school teachers in low-and-middle-income countries is often hampered by the lack of freely available classroom observation tools that are feasible to administer, validated in their own setting, and can be used as part of national monitoring systems. To address this discrepancy, Teach, an open-access classroom observation tool, was developed to measure the quality of teaching practices of primary school teachers in low-and-middle-income countries. This paper uses data from Punjab, Pakistan to evaluate the validity of Teach. Results show that Teach scores were internally consistent, presented good inter-rater reliability, and provided sufficient information to differentiate low from high-quality teaching practices. Further, higher Teach scores were associated with higher student outcomes.  相似文献   

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