A Cross-Age Study of the Understanding of Three Genetic Concepts: How Do They Image the Gene, DNA and Chromosome?

The study was carried out with 175 Turkish students by using drawings at different ages understanding of gene, DNA and chromosome concepts. Students from 8th, 9th, 11th grades and, science and biology student teachers were simply asked to draw the structure of gene, DNA and chromosome in a cell and also to give explanations about these three concepts. Differences in understanding between the age groups were found to be significant for the concepts of gene and DNA. None of the groups exhibit sound understanding and regardless of the age levels, students in all groups had alternative ideas about the three concepts investigated.     

Genes, environment, and dyslexia the 2005 Norman Geschwind memorial lecture

This article presents an overview of some methods and results from our continuing studies of genetic and environmental influences on dyslexia, and on individual differences across the normal range that have been conducted over the past 25 years in the Colorado Learning Disabilities Research Center (CLDRC) and in related projects. CLDRC investigators compare the similarities of identical twin pairs who share all their genes and fraternal twins who share half their segregating genes to assess the balance of genetic, shared family environment, and nonshared environment influences on dyslexia and on individual differences across the normal range. We have learned that among the children we have studied in Colorado, group deficits in reading (dyslexia) and individual differences in reading across the normal range are primarily due to genetic influences, and these genetic influences are often shared with some of the same genetic influences on deficits and individual differences in language and ADHD. We have also learned from our molecular-genetic linkage studies that there are regions on several chromosomes likely to contain genes that influence dyslexia. Several specific genes within these regions have been tentatively identified through molecular-genetic association analyses, but much more research is needed to understand the pathways among specific genes, regions of noncoding DNA that regulate the activity of those genes, the brain, and dyslexia. I conclude with a discussion of our research on individual differences in early reading development, on the role of early learning constraints in dyslexia, and on how genetic influences are expressed through their interaction and correlation with the environment.     

Types and Qualities of Knowledge and their Relations to Problem Solving in Physics

Based on empirical findings and theoretical considerations related to the field of expertise research, the importance of “types” and “qualities” of knowledge in relation to problem solving in physics was investigated. The students (N =138) in this study had a level of competence that corresponds to an intensive beginner college course in physics. It was found that conceptual declarative knowledge and problem scheme knowledge are excellent predictors of problem solving performance. However, a detailed analysis shows that the first knowledge type is more typical for low achievers (novices) in physics problem solving whereas the second type is predominately used by high achievers (experts). Regarding types and qualities of knowledge and their relations to problem solving, the results of a multidimensional scaling analysis (MDS) indicate that two dimensions of knowledge can be distinguished. On the extreme limits of the first dimension, which could be named “problem solving relevance vs. structure of discipline”, are the types of knowledge and the qualities of knowledge, respectively. The second dimension of knowledge could be named “single knowledge elements vs. organised knowledge units”. There are types of knowledge as well as qualities of knowledge distributed along this dimension. Consequences of these results for improving physics education are discussed.     

Using the known to chart the unknown: A review of first-language influence on the development of English-as-a-second-language spelling skill

Currently, there is a practical demand and necessity for research on how English-as-a-second language (ESL) learners acquire literacy skills, such as spelling. One important issue of this research agenda is how ESL learners apply first-language knowledge to learning to spell in English. Twenty-seven studies were reviewed that investigated the influence of the first language on ESL learners’ development of English spelling skill. Evidence was found for both positive and negative transfer of first-language knowledge and processes to ESL learners’ English spelling. These results are in agreement with theoretical propositions about the interdependence between first- and second-language academic skills [e.g., Cummins, J. (1981). In California State Department of Education (Ed.), Schooling and language minority students: A theoretical framework (pp. 3–49). Los Angeles: Evaluation, Dissemination, and Assessment Center, California State University, Los Angeles]. The findings are discussed in relation to the ESL learner’s first-language proficiency level and distance between first language and English. Comparisons are drawn between ESL learners’ and English monolinguals’ spelling development and suggestions for future research are provided.     

从代理成本看国有企业产权改革的路径选择

国有企业的代理成本与其他所有制企业的代理成本相比高了许多。从委托-代理理论及现有的国有企业代理成本的研究成果来看,国有企业委托-代理关系具有特殊性,其代理成本过高的根源在于产权不清晰。     

The Centros Concertados in Spain, Parental Demand and Implications for Equity

In Spain, the exercise of choice by parents of a suitable school for their children is not practised by all families in the same way. The evidence shows that an increasing social polarisation and a substantial disequilibrium in schooling are taking place in compulsory education. There is a high concentration of immigrant students in public schools in contrast with what happened in the centros concertados (private schools with public funding). This situation is especially unbalanced in some Autonomous Communities, such as the Community of Madrid, Catalonia, Valencia and Andalusia. The inequalities in the distribution of students in the network of public schools and private schools financed by public funds are producing significant responses from parents, teachers, experts, and also from other social groups. Some of the proposals made by different experts and by the Spanish Ministry of Education are analysed in order to reach to a quality education in more equitable conditions for all students.     

高考政策的国家利益优先性探讨

高考政策属于国家的公共政策。作为高校招生考试,高考应该坚持高等教育领域的国家利益优先性,但因为高考政策同时涉及为高校输送新生的基础教育领域的国家利益,而且基础教育领域的国家利益比高等教育领域的国家利益影响更为广泛、更为久远,所以高考政策应在为高校选拔新生的同时,坚持基础教育领域的国家利益优先。但现实却是,有些高考政策使基础教育领域的国家利益优先性体现不充分。这就要求高考政策进行必要的、及时的改革。     

基层电大开放教育接轨农村、服务农民的和谐理念

致力于中国农民素质教育是电大系统实施网络教育必须担负的历史使命,基层电大接轨农村、服务农民是开放教育可持续发展的必然趋势。当今农村地区发展的不平衡现状和农民个体活动呈现的独立性、选择性、多变性等形态,决定了各地基层电大在向农村和农民实施开放教育的过程中,必须于教育观念、教育技术以及教育中远期目标上紧紧把持和谐的理念。