DNA分子中的螺旋结构与功能

DNA是生物体遗传信息的载体,而其中的螺旋结构具有重要的生物学功能.右手双螺旋DNA结构是其贮存和传递遗传信息的分子基础,调控蛋白通过识别双螺旋沟中的信息调节基因表达;原核细胞的染色体DNA形成的负超螺旋分区结构有利于基因表达时的操纵子的协同调节;真核细胞线状染色体DNA缠绕组蛋白形成的负超螺旋,以及超螺旋环也是基因复制与表达所必需的.     

Teaching Bioinformatics and Neuroinformatics by Using Free Web-based Tools

This completely computer-based module''s purpose is to introduce students to bioinformatics resources. We present an easy-to-adopt module that weaves together several important bioinformatic tools so students can grasp how these tools are used in answering research questions. Students integrate information gathered from websites dealing with anatomy (Mouse Brain Library), quantitative trait locus analysis (WebQTL from GeneNetwork), bioinformatics and gene expression analyses (University of California, Santa Cruz Genome Browser, National Center for Biotechnology Information''s Entrez Gene, and the Allen Brain Atlas), and information resources (PubMed). Instructors can use these various websites in concert to teach genetics from the phenotypic level to the molecular level, aspects of neuroanatomy and histology, statistics, quantitative trait locus analysis, and molecular biology (including in situ hybridization and microarray analysis), and to introduce bioinformatic resources. Students use these resources to discover 1) the region(s) of chromosome(s) influencing the phenotypic trait, 2) a list of candidate genes—narrowed by expression data, 3) the in situ pattern of a given gene in the region of interest, 4) the nucleotide sequence of the candidate gene, and 5) articles describing the gene. Teaching materials such as a detailed student/instructor''s manual, PowerPoints, sample exams, and links to free Web resources can be found at http://mdcune.psych.ucla.edu/modules/bioinformatics.     

Promoting more future-ready anatomy education after the Covid-19 pandemic: A scoping review

The coronavirus disease 2019 (Covid-19) pandemic caused an abrupt transition from face-to-face to online anatomy teaching, learning, and assessment. Although online education has ensured the continuity of anatomy education during the pandemic, its implementation has been challenging, and its effectiveness has been questioned. Therefore, literature pertinent to online anatomy education during the pandemic is crucial to explain Covid-19's disruptions to this field. Accordingly, this scoping review explored changes, disruptions, and gaps in anatomy teaching and assessment during Covid-19 using an enhanced version of Arksey and O′Malley's six-stage protocol. Five online databases were searched for articles that described changes and disruptions in anatomy education. Three independent researchers were involved in titles, abstracts, and full texts screening, while another four researchers were independently involved in data extraction, charting, and synthesis. This review revealed six themes: immediate strategic plans and actions, teaching and learning changes, online assessment practice, students' and educators' receptivity and adaptability, online learning and assessment effects, and future directions. It also revealed four gaps: non-future-ready curricula, learning obstacles, administrative and teaching challenges, and online education ethical issues. The results were reported in tabular and narrative forms, following the PRISMA Extension for Scoping Reviews (PRISMA-ScR guidelines). Understanding the evolution and gaps in anatomy education during the Covid-19 pandemic will help anatomists design future-ready, adaptable curricula.     

Characterization of Pathogenic Human MSH2 Missense Mutations Using Yeast as a Model System: A Laboratory Course in Molecular Biology

This work describes the project for an advanced undergraduate laboratory course in cell and molecular biology. One objective of the course is to teach students a variety of cellular and molecular techniques while conducting original research. A second objective is to provide instruction in science writing and data presentation by requiring comprehensive laboratory reports modeled on the primary literature. The project for the course focuses on a gene, MSH2, implicated in the most common form of inherited colorectal cancer. Msh2 is important for maintaining the fidelity of genetic material where it functions as an important component of the DNA mismatch repair machinery. The goal of the project has two parts. The first part is to create mapped missense mutation listed in the human databases in the cognate yeast MSH2 gene and to assay for defects in DNA mismatch repair. The second part of the course is directed towards understanding in what way are the variant proteins defective for mismatch repair. Protein levels are analyzed to determine if the missense alleles display decreased expression. Furthermore, the students establish whether the Msh2p variants are properly localized to the nucleus using indirect immunofluorescence and whether the altered proteins have lost their ability to interact with other subunits of the MMR complex by creating recombinant DNA molecules and employing the yeast 2-hybrid assay.     

Influences of reading online texts in Korean English language learners' cultural identities

This qualitative case study investigated 4 Korean elementary level English language learners' (ELLs) cultural identities when they read online texts at home and school. The participants were fourth- or fifth-grade students. The data consisted of observations, interviews, field notes, reflective journals, and the ELLs' verbal reports at home and school between the spring and the fall of 2010. The author's purpose was to identify the influences of reading online texts at home and school in Korean elementary level ELLs' cultural identities. Findings revealed that the online text readings helped the ELLs form, maintain, and shift their cultural identities. The author discusses Korean ELLs' languages, cultures, and technologies in the contexts of electronic literacies and suggests educational implications to facilitate their reading online texts.     

Liberal education: An overlapping pragmatic consensus

In reviewing the course of liberal education in the US during the 20th century, Bruce Kimball in 1995 proposed that a pragmatic consensus was emerging about the understanding of liberal education. The two-fold tradition of liberal education, with its shifting emphases and accommodations between 'orators' and 'philosophers,' was being transformed into a 'new American tradition of liberal education deeply rooted in the resurgent intellectual tradition of pragmatism'. A number of different, even contradictory, criticisms of Kimball's thesis have been offered concerning the existence and nature of such a consensus and its relationship(s) to pragmatism. We suggest that the consensus thesis and the criticisms it has encountered might be best understood by comparing it to Rawls's idea of an 'overlapping consensus'. Comparing and contrasting Kimball's project and Rawls's approach suggests that the emerging consensus concerning liberal education at the beginning of the 21st century is an overlapping consensus, that is, a consensus whose nature is pragmatic, as well as a consensus whose substantive tenets are rationalized by pragmatism. Understanding the consensus in this way accounts for the varied criticism that Kimball's thesis has received and makes a significant difference in understanding the theory and practice of liberal education in the 21st century.     

如何提高学生的在线自我调节学习？——基于先前在线学习经历与家庭背景的比较

在线教学中学生要具备一定的在线自我调节学习能力才能取得好的学习成效,而学生的在线自我调节学习受诸多因素的影响。本研究从先赋性背景和后致性学校过程性因素的视角,基于“新冠疫情期间研究型大学本科生学习体验调查”项目中某大学的数据,考查学生家庭背景和先前在校在线学习经历与在线自我调节学习的关系。研究发现：家庭背景和先前在校的在线学习经历都显著影响学生在线自我调节学习,且先前在线学习经历的影响独立于家庭背景。超过七成的学生在新冠肺炎疫情前有过在线学习经历,且主要是来源于本校的正式在线学分课。这一研究结果的实践启示是：高校可以通过提供正式在线学习的机会抵消学生家庭背景的负面作用来培养学生的在线自我调节学习,这将有助于他们应对紧急情况下大规模在线教学时可能面临的挑战。     

Economics of Education. The Need to go Beyond Human Capital Theory and Production-Function Analysis

Human capital theory takes for granted that an individual's demand of education will automatically be transformed into real human capital: there is no supply constraint or, said differently, educational systems can be assimilated to 'neutral' black boxes mechanically transforming input into output. This optimistic view of human capital production was rapidly abandoned. In the late 1960s some economists began to revise the assumption that the black box's functioning was neutral with regard to human capital production. Supply-side economics of education appeared first under the form of production-function analysis. It was initially believed that the information delivered by such input/output approach would help policy makers and administrators choose the most productive 'mix' of inputs. But the major conclusion of this line of research is that there is apparently no clear and undeniable relation between both expenditure per student and the specific resources they can buy (teachers' degrees and experience, smaller student-teacher ratios) on the one hand, and student achievement on the other hand. This probably means that further conceptual development is necessary to overcome the current analytical - and also political - deadlock. This paper argues that one promising way consists of introducing organisational assets as well as non-monetary inputs into the production function paradigm.     

Learning through science writing via online peer assessment in a college biology course

This study used an online peer assessment activity to help 47 college students to learn biology through writing. Each student submitted a biology writing report to an online system and then experienced three rounds of peer assessment. During the online peer assessment process, self, peer and expert evaluation scores for the writing were gathered across three rounds. It was found that self-assessment scores were not quite consistent with the expert's scores, but the peer assessment scores demonstrated adequate validity with the expert's evaluation. In particular, when the students had more rounds of peer assessment for reviewing the writing, the validity of the peer scores was enhanced. An examination of the students' writing scores, allocated by peers and expert, indicated that the students significantly improved the writing as the peer assessment activity proceeded. Content analyses of the students' writing also revealed that their writing gradually developed with significantly better coverage, richness and organization resulting from the online peer assessment activity.     

Increasing Student Success Using Online Quizzing in Introductory (Majors) Biology

Students often complain about their perceived disconnect between the time and effort spent studying and their subsequent performance on exams. Robert Bjork''s research asserts that retrieval of stored information acts as a memory modifier, and that using tests as learning events creates “desirable difficulties that enhance learning.” To determine the effect of utilizing testing as a learning event in the introductory (majors) biology classroom, we used an online homework platform to give required quizzes throughout the course. Analysis of exam grades earned by those taking 100% of pre-exam quizzes indicates that not only does this group have a significantly higher exam average than the group of students who took 0% of the pre-exam quizzes, but they also have a significantly higher exam average than the class average. Through detailed, statistical analysis, the benefit of quizzing is demonstrated to be significant for students of diverse academic abilities. Pre-exam quizzing using an online homework platform is an effective way to increase student performance on exams and allows class time to be utilized for teaching activities.     

A comparison of teacher and principal perception of an outstanding biology teacher

The purpose of this study was to ascertain the level of agreement or disagreement between principals and teachers when using established criteria to measure the effectiveness of a biology teacher. To obtain information regarding their perceptions of an outstanding biology teacher, twenty-two principals and forty-one biology teachers were chosen randomly from English-speaking high schools within a 50 km radius of metropolitan Montreal, Quebec, Canada. The measuring instrument was a modified version of Dieter's questionnaire that evolved from his doctoral study of the National Association of Biology Teachers-Outstanding Biology Teacher Award Program. The data collected from the two populations were tested using one-way ANOVA (analysis of variance) or by applying normal approximation. Results indicated that both the principals and teachers agree on the relative importance of most criteria, particularly those related to the teacher's classroom behavior and academic background in biology. From such results, it was possible to construct one stereotype of the outstanding biology teacher. A number of recommendations were made from the results of the study, which were directed to the (a) teachers and their professional organization, (b) principals and the school boards, (c) teacher training institutions, and (d) researchers in teacher evaluation.     

A footnote in the psychology of persuasion

The rhetorical problem of concretizing the ideal is explored via the relationship between form and fact in Richard Weaver's theory of truth. The investigation reveals that reliance on analogic form permits Weaver's arguments to function externally as if empirically grounded and internally in the analytic fashion of logico‐mathematical reasoning. Explication of Weaver's rhetorical method suggests that analogic structure, example, and analogy are fundamental ways of rhetorical knowing.     

The Human in the Machine: Reflections on mentoring at the British Open University

Mentoring has had a key role in the British Open University's intricate distance education system for more than 30 years. However, it has changed very substantially as the system's technology has changed. In this article, after providing some definitions, I review the early history and the changes that have put mentoring online. I describe my own experience as a tutor in the university's online MA in Open and Distance Education, and explain Salmon's model for e-moderating (e-mentoring) developed in the university's Business School. Finally, I reflect on mentoring online today: what is essential for us to understand is how the best of 'old-fashioned' mentoring face-to-face can be built into online mentoring together with the best of what the technology enables us to do. Mentors must learn to weave ideas online, with their students, empowering them to do likewise. The mentor, 'the human in the machine', is indispensable.     

王微的“疾病书写”及其文学史意义

寒食(五石)散中毒引起的药源性疾病深刻影响了刘宋王微的文学创作,相较于皇甫谧和王羲之、王献之父子等前辈作家,王微将石药中毒情形的描写与病人幽微情绪的传达有机地融为一体,其文"怨思抑扬",具有感人至深的力量。与今人对中国古代文学"疾病书写"传统的通常认知不同,它表明,至晚在刘宋时期,作家们就已经开始在文学创作中把"病残之躯的展示"和"生命意义的思考"有机结合起来,此举丰富了文学的题材、拓展了文学表现世俗生活的疆域,为后世的"涉病文学"创作提供了资源,是晋唐"疾病书写"传统演进过程中的重要一环。     

Addressing the Wellness Needs of Online Distance Learners

As more opportunities for enrolling in online courses and programs become available, ensuring the quality of such educational experiences will continue to increase in importance. One factor determining quality concerns the student support services available to distance learners. Unfortunately, these services are often underdeveloped or overlooked, especially those support services associated with the 'extracurricular needs' of distance learners. The inclusion of wellness resources within the instructional design of an online course is one approach attempting to meet the challenge of providing such services to learners. The purpose of this study was to determine which student support service resources should be included in an Online Wellness Resource Center (OWRC) available within an online course. A needs assessment was conducted to determine whether learners perceived a need for access to wellness resources. Finding that they did express this need, the assessment then identified the specific wellness resources to include in an OWRC.     

Understanding Early Elementary Children's Conceptual Knowledge of Plant Structure and Function through Drawings

This study examined children''s drawings to explain children''s conceptual understanding of plant structure and function. The study explored whether the children''s drawings accurately reflect their conceptual understanding about plants in a manner that can be interpreted by others. Drawing, survey, interview, and observational data were collected from 182 students in grades K and 1 in rural southeastern United States. Results demonstrated the children held a wide range of conceptions concerning plant structure and function. These young children held very simple ideas about plants with respect to both their structure and function. Consistent with the drawings, the interviews presented similar findings.     

“嵌入”与“破局”：疫情背景下我国国际科研合作关系的延续与创新

本研究分析了2016—2021年我国国际科研合作的特点与趋势。通过对中国学者国际合作文章发表数据的描述性分析和对参与国际合作的18位中国学者的访谈，分析了疫情背景下中国国际科研合作在伙伴国家、合作学科、合作模式等方面的趋势，探讨了影响我国建立和保持国际科研合作关系的因素。研究发现，中美合作势头较之十年前有所放缓，中国与“一带一路”国家的科研合作增长较快，且学科分布较为广泛。“优先依附”与“同质性”是中国与传统科研伙伴合作的重要机制，新的国际局势和新冠疫情制约了中国学者新型国际合作关系的建立，影响程度与其合作关系的来源和强度有关。未来中国可将“一带一路”国家作为国际科研合作的增长点，着力提升对关键合作要素的贡献，建立跨国合作“退潮”的防御机制，以应对新形势下所可能面临的风险与挑战。     

Family resources and mid‐life level of education: a longitudinal study of the mediating influence of childhood parental involvement

This paper draws on the concept of parental involvement, popular among educators and policy‐makers, in investigating differences in level of attained education by family background. The question is if parental involvement in children's schooling at age 14 acts as a mediator between family resources and mid‐life level of attained education. Using structural equation modeling we analyze longitudinal survey and register data of a Swedish metropolitan cohort born in 1953 (n = 3300). Several of the commonly used indicators of involvement are investigated, distinguishing between parents' involvement beliefs, such as educational aspirations and agreement with school curriculum, and involvement practices, such as reading children's schoolbooks and helping with homework. We find that parents' educational aspirations are an important mediator between family resources and attained level of education, while other involvement forms are related to academic performance only. We also find that parental involvement is greater in families with more resources, which leads us to warn against developments turning more responsibility for children's schooling over to parents. Unless sensitive to the diverse family contexts this might increase the importance of family resources for children's educational outcomes.