Elaborating the structures of a science discipline to improve problem-solving instruction: An account of Classical Genetics' theory structure,function, and development

Situating the conceptual knowledge of a science discipline in the context of its use in the solving of problems allows students the opportunity to develop: a highly structured and functional understanding of the conceptual structure of the discipline; general and discipline-specific problem-solving strategies and heuristics; and insight into the nature of science as an intellectual activity. In order realize these potential learning outcomes, the reconstructions of scientific theories used in problem solving must provide a detailed account of (1) realistic scientific problems and their solutions; (2) problem-solving strategies and patterns of reasoning of disciplinary experts; (3) the various ways that theories function for both disciplinary experts and students; and (4) the way theories, as solutions to realistic scientific problems, develop over time. The purpose of this paper, therefore, is to provide further specificity regarding a philosophical reconstruction of the structure of Classical Genetics Theory that can facilitate problem-solving instruction. We analyze syntactic, semantic and problem-based accounts of theory structure with respect to the above criteria and develop a reconstruction that incorporates elements from the latter two. We then describe how that reconstruction can facilitate realistic problem solving on the part of students.     

Effects of breakfast with different calorigenic amounts on blood glucose, insulin and glucagon levels

This study was aimed to investigate the relationship between breakfast and serum glucose, insulin and glucagon concentrations in order to establish a model breakfast appropriate for Chinese. Twenty-four volunteers were randomly assigned to four study groups: high carbohydrate breakfast, high fat and protein breakfast, the typical breakfast and fasting. Each subject had serum and urine samples collected while fasting and at 1,2 and 3.5 hours following the meal. The concentration of serum glucose, insulin and glucagon was measured. The levels of serum glucose in group A,B and C differed significantly at 1 and 2 hour after meal compared to those at fasting (P<0.05). The serum glucose in group A increased insignificantly after meal. The serum insulin levels were in group A,B and C significant different compared with control group(P<0.05).Those peaked at 1 hour after meal ,with group C rising the furthest. Compared with the fasting group, the serum glucagons rose and maintained the increase after breakfast in group A,B and C (P<0.05).The data suggested that various diets with different calorigenic amounts increased hormone concentration to various extents. We found that a breakfast rich in carbohydrates could maintain proper blood glucose level.     

Beginning teachers’ perceptions of their levels of pedagogical knowledge and skills: did they change since their graduation from initial teacher preparation?

This study investigated changes in beginning teachers’ self-perceptions of their pedagogical knowledge and skills after their first year of teaching. Surveys were administered to 322 graduating student teachers at the end of the initial teacher preparation programme and at the end of their first year of teaching to compare if there were any differences in their self-perceptions. The results of the study showed significant increases in beginning teachers’ perceptions of their pedagogical knowledge and skills in three factors: Instructional Support, Accommodating Diversity and Classroom Management. Results established the development of teachers to be an ongoing process that is initiated but not completed in initial teacher preparation. Implications of findings for induction and mentoring of beginning teachers are discussed.     

A structural analysis of market competition in the U.S. TV syndication industry, 1981–1990

The author explores how the structure of the national television programming market has changed during the past decade and finds that the market has become highly concentrated and is increasingly being dominated by foreign owners. The author argues that the trends provide support for relaxation of prohibitions on television networks’ participation in syndication     

The influence of lexical and sublexical variables in normal and poor Spanish readers

The main aim of our study was to find out the effect of several lexical and sublexical variables (lexical category, lexical frequency, syllabic structure, and word length) in the acquisition of reading in a transparent language such as Spanish. The second goal of our study was the comparison of the effect of these variables in normal and poor Spanish readers. One hundred and forty children (aged between 6 and 12), twenty of whom were poor readers, were tested using a reading test of 306 items in which we balanced all the variables. The dependent variable was the percentage of correct responses in a decontextualized word reading test. Our results showed that all the above mentioned variables produced a significant effect on the number of errors made by the children. This pattern of results suggests no difference between the processes involved in the reading acquisition of Spanish and those implicated in deep orthographies such as English. Our results also showed no qualitative differences between normal and poor readers. The four variables studied showed the same behaviour in their effect on reading performance for both normal and poor readers, indicating that poor readers also use both the lexical and the phonological route. Our data suggest the universality of the dual route model, independent of the transparency or opaqueness of the different alphabetical languages.     

Information Technology and Gender. Problems and Proposals

The paper examines the possible reasons why there is a gender bias towards males studying computing at secondary school level. The authors have surveyed recent research in the area of information technology (IT) and gender, highlighted some of the major areas for discussion and made a number of recommendations for improving classroom practice. The recommendations are arranged under five headings: access to the curriculum; course design; teachers' attitudes and teaching styles; language; assessment issues; and the role of technology. The aim is to alert teachers to the importance of considering how gender bias is being perpetuated, and then to examine how practice can be improved. The recommendations follow the example already set by the Association for Science Education in the United Kingdom, and note the work done in Scotland by the General Teaching Council in addressing gender as a key issue. Although the discussion focuses upon the Scottish context and in particular the development of computing studies, many of the points apply equally well to the introduction of IT as a cross‐curricular theme at both the primary and secondary stages. This is particularly relevant as IT is a significant development within the 5‐14 Programme in Scotland and mirrors innovation in the area of IT in England and Wales.