Learning Gene Expression Through Modelling and Argumentation

There is emerging interest on the interactions between modelling and argumentation in specific contexts, such as genetics learning. It has been suggested that modelling might help students understand and argue on genetics. We propose modelling gene expression as a way to learn molecular genetics and diseases with a genetic component. The study is framed in Tiberghien’s (2000) two worlds of knowledge, the world of “theories & models” and the world of “objects & events”, adding a third component, the world of representations. We seek to examine how modelling and argumentation interact and connect the three worlds of knowledge while modelling gene expression. It is a case study of 10th graders learning about diseases with a genetic component. The research questions are as follows: (1) What argumentative and modelling operations do students enact in the process of modelling gene expression? Specifically, which operations allow connecting the three worlds of knowledge? (2) What are the interactions between modelling and argumentation in modelling gene expression? To what extent do these interactions help students connect the three worlds of knowledge and modelling gene expression? The argumentative operation of using evidence helps students to relate the three worlds of knowledge, enacted in all the connections. It seems to be a relationship among the number of interactions between modelling and argumentation, the connections between world of knowledge and students’ capacity to develop a more sophisticated representation. Despite this is a case study, this approach of analysis reveals potentialities for a deeper understanding of learning genetics though scientific practices.     

Hierarchical models for failure analysis of plates bent by distributed and localized transverse loadings

The failure analysis of simply supported, isotropic, square plates is addressed. Attention focuses on minimum failure load amplitudes and failure locations, von Mises＇ equivalent stress along the plate thickness is also addressed. Several distributed and localized loading conditions are considered. Loads act on the top of the plate. Bi-sinusoidal and uniform loads are taken into account for distributed loadings, while stepwise constant centric and off-centric loadings are addressed in the case of localized loadings. Analysis is performed considering plates whose length-to-thickness ratio a/h can be as high as 100 （thin plates） and as low as 2 （very thick plates）. Results are obtained via several 2D plate models. Classical theories （CTs） and higher order models are applied. Those theories are based on polynomial approximation of the displacement field. Among the higher order theories （HOTs） HOTsa models account for the transverse shear deformations, while HOTs models account for both transverse shear and transverse normal deformations. LHOTs represent a local application of the higher order theories. A layerwise approach is thus assumed： by means of mathematical interfaces, the plate is considered to be made of several fictitious layers. The exact 3D solution is presented in order to determine the accuracy of the results obtained via the 2D models. In this way a hierarchy among the 2D theories is established. CTs provide highly accurate results for a/h greater than 10 in the case of distributed loadings and greater than 20 for localized loadings. Results obtained via HOTs are highly accurate in the case of very thick plates for bi-sinusoidal and centric loadings. In the case of uniform and off-centric loadings a high gradient is present in the neighborhood of the plate top. In those cases, LHOTs yield results that match the exact solution.     

Among friends: the role of academic-preparedness diversity in individual performance within a small-group STEM learning environment

In this study, we investigate the relationship between academic-preparedness diversity within small learning groups and individual academic performance in science, technology, engineering, and mathematics (STEM) university courses. We further examine whether academic-preparedness diversity impacts academically more- and less-prepared students differently. We use data from 5367 university students nested within 1141 science, engineering, and mathematics learning groups and use a regression analysis to estimate the effect of group diversity, measured in two ways, on course performance. Our results indicate that academic-preparedness diversity is generally associated with positive learning outcomes, that academically less-prepared students derive greater benefit, and that less-prepared students fare best when they are not alone in a group of highly prepared students. Implications for teaching and small-group facilitation are addressed.     

‘Let's Save Energy!’: incorporating an environmental education dimension in the teaching of energy

A curricular unit called ‘Let's Save Energy!.’ was developed and tested as part of a project of Science Materials for Secondary Education. The project is focused on human needs, and how Science relates to them. This paper discusses how E.E. is built into a ‘traditional’ science topic (Energy), and some of the activities used to develop an awareness about the need and ways to ‘save’ Energy. A simulation game is presented with a focus on international co‐operation and environmental protection. The process of the development of the materials, and some results of its use in the classroom with 15/16‐year‐old pupils are discussed.     

Customer’s role in knowledge management and in the innovation process: effects on innovation capacity and marketing results

Scholars have acknowledged customer knowledge management (CKM) as a key strategic resource for improving innovation and supporting long-term customer relationship management. This study provides a deeper understanding of the internal antecedents of business innovation capacity overcoming previous approaches. A model that had not previously been tested was used to analyse the role of customer collaboration and CKM – measured as a second-order construct – in innovation processes and marketing results. To test the model, structural equation modelling (partial least squares) was applied to a random sample of 210 Spanish companies. Results confirm that CKM and customer collaboration are antecedents of innovation capacity and marketing results. Furthermore, the effect of CKM is greater than the effect of customer collaboration. This paper provides a basis for managers to encourage innovation in their companies and explains how managers can improve marketing results.     

NARST: a lived history

In this Forum, we construct a history of the National Association for Research in Science Education (NARST) through the analysis of documents and through the personal perspectives of individuals. The history of NARST is inseparable from the biography of the individuals through whose lives it was produced and reproduced. The history of NARST is a living history that both shapes and was shaped by the biographies of its members.

Special education in Spain at the beginning of the 21st century: the challenge to educate in an unequal and multicultural society

An overview of the challenges facing the Spanish Special Education system at the turn of the century is presented. Significant changes have occurred in Spain over the last two decades that have affected the landscape of Spanish public schools in an unprecedented way. First, since the late 1980s, students with a variety of disabilities have been attending general education classrooms along with their peers. Additionally, for the last 20 years, Spain has experienced a dramatic increase in immigration patterns from Northern Africa, Eastern Europe and Latin America. Thus, Spanish educators are facing the challenge of educating an increasingly heterogeneous student body. Students' different educational needs are often handed down to the special educator teacher who is faced with the task of ensuring the student's academic and social participation. Reform efforts conducted by Spanish educators to ensure that all students, regardless of their gender, ability level, ethnic and social backgrounds, as well as language and religion of origin, have equal access to a full social and academic participation in their schools and communities are described.