Should students design or interact with models? Using the Bifocal Modelling Framework to investigate model construction in high school science

The Bifocal Modelling Framework (BMF) is an approach for science learning which links students’ physical experimentation with computer modelling in real time, focusing on the comparison of the two media. In this paper, we explore how a Bifocal Modelling implementation supported learning outcomes related to both content and metamodeling knowledge, focusing on the role of designing models. Our study consisted of three conditions implemented with a total of 69 9th grade high-school students. The first and second classes were assigned two implementation modes of BMF: with and without a model design module. The third condition, employed as a control, consisted of a class that received instruction in the school’s traditional approach. Our results indicate that students participating in both BMF implementations demonstrated improved content knowledge and a better understanding of metamodeling. However, only the ‘BMF-with-design’ group improved significantly in both content and metamodeling knowledge. Our qualitative analyses indicate that both BMF groups designed detailed models that included scientific explanations. However only students who engaged in the model design component: (1) completed a detailed model displaying molecular interaction; and (2) developed a critical perspective about models. We discuss the implications of those results for teaching scientific science concepts and metamodeling knowledge.     

Analysis of a varnish applied by Nicéphore Niépce to make a print used for photographic purpose transparent

Nicéphore Niépce carried out a lot of meticulous experiments that led him to the invention of photography. In particular, in the 1820s, he obtained heliographs by coating a substrate with a light-sensitive substance, which was then exposed to light under a paper print made translucent with the help of varnish. The objective of the work described here is to determine how Niépce made these paper prints transparent. Did he use his experimental knowledge on photosensitive resins, or did he apply commonly used recipes of his time to make paper transparent? To date, no studies have been carried out on the varnish used by Nicéphore Niépce and no previous research has undertaken analytical investigations on Nicéphore's prints, using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Gas Chromatography/Mass Spectrometry (GC/MS). In this paper, we identify the varnishes used by Nicéphore Niépce on four transparent prints, now belonging to the Nicéphore Niépce museum in Chalon-sur-Saône, France. The varnish he used was based on a diterpenic Pinaceae sp. resin (most probably colophony). The finding is supported by historical knowledge about varnishes.     

LEDs as a tool to enhance faded colours of museums artefacts

A procedure to enhance the faded colours of museums artefacts is presented. The method is based on adjusting the spectral profile of the light while maintaining a given white colour of the illumination. The procedure is tested using colour LED clusters and a series of damaged samples and their good condition counterparts. The intensity of the three components of four feasible LED clusters is computed in order to produce white illumination metameric to a white LED light source taken as a reference. Colorimetric calculations are performed to model the colour changes undergone by target colour samples using illumination based on colour LED association with respect to the white LED reference. The model is based on CIELAB specification and allows to optimize the choice of three-colour LED associations that modify the hue and the saturation of a few target colour areas of illuminated samples while other areas are left moderately desaturated. Modelling and experimental visual validation were practically obtained by adjusting the intensity of five calibrated colour LEDs, blue, cyan, green, amber and red, accommodated in a light booth. A visual validation was conducted asking 20 observers to rate the colourfulness appearance of aged inkjet prints under every LED cluster with respect to the colourfulness of their original counterparts under the reference white LED source. The visual assessments agreed with the colorimetric predictions. Finally, a demonstration is shown of the feasibility of the method by simulating the rejuvenated appearance of a natural history specimen of which the museum possesses two differently aged items.     

Effects of foreign acquisitions on R&D activity: Evidence from firm-level data for France

This paper investigates the causal effect of foreign acquisitions on the research and development (R&D) activities of domestic target firms over the period 1994–2004. Using accounting data on French innovative manufacturing firms, we implement appropriate difference-in-difference estimation techniques associated with a matching propensity score procedure. We find that the acquisitions of French firms by foreign companies boost R&D spending. There is a simultaneous rise in the external and in-house R&D expenditures of French acquired firms. R&D is more contracted out to local research providers, in particular to local public laboratories and universities. The increase in internal R&D spending benefits to development, but also basic and applied research. Finally, the growth of the R&D budget is not only financed by internal resources but also receives financing from external partners, especially parent companies. Thus, our results call into question the idea that foreign takeovers hamper the R&D development of target firms and are detrimental to the national innovation system of the host country. First, acquisitions appear to bring efficiency gains enough to counterbalance the various costs of integration and market power effects, pushing firms to invest more in R&D. Acquisitions do not seem to incite managers to take shorter term and more financial driven decisions at the expense of R&D. Second, when motivated by technology sourcing and overseas R&D development, acquisitions might be used to access the specific know-how of target firms and to tap into the knowledge of the national innovation system. Then, purchaser firms could be more likely to develop the innovative capability of target firms and to strengthen their linkages with local partners than to reduce them and relocate R&D abroad.     

Pédagogie and didactique: An incestuous relationship

This article deals with the evolution of pedagogical theory in the Francophone world. At present, two major currents of reflection on education exist in the Francophone world. The first, called didactique – didactics – relates to teacher planning, working chiefly from considerations about the pupil's cognitive characteristics. The second, called pédagogie – pedagogy – relates to the features of pedagogical reflection-in-action. This article analyzes the distinctions between the two currents with a view to determining whether they constitute genuine differences.     

Boys who don’t like sports: family lifestyle and transmission of dispositions

Many studies have stressed the key role played by competitive sports in the socialization of boys, particularly in middle-class families. This article looks at the minority group of boys from this social class who dislike competition and participate in few, if any, sports. We present case studies of six boys and their families, interviewed on several occasions. Based on Bourdieu’s [1979. La Distinction. Une critique sociale du jugement [Distinction. A social critique of the judgement of taste]. Paris: Minuit; 1980. Le sens pratique [Practical reason. On the theory of action]. Paris: Minuit] theoretical framework and the concepts of capital, habitus, and lifestyle, we analyze the socialization modes involved in the construction of an atypical gender habitus. All of the boys we interviewed had developed a liking for activities socially attributed to females, in specific family configurations. Beyond these common points, our data allowed us to identify two groups of families: in the middle-class families well endowed with cultural capital, the parents place priority on a ‘cultivated’ lifestyle and pass on to their sons a taste for mainstream cultural activities, which (from their point of view) do not include sports. In the middle-class families less interested in mainstream cultural forms, the parents wish their sons were more sports-oriented. In these homes, there is evidence of problems related to the transmission of the paternal sports capital.     

Mass deacidification of papers and books: V. Fungistatic properties of papers treated with aminoalkylalkoxysilanes

A new process using aminoalkylalkoxysilanes (AAAS) was developed recently for paper and book mass deacidification. This process is entirely novel in that, besides deacidifying, it also improves the mechanical properties of paper. In the present article, the properties of inhibition of fungal growth of the treated papers are investigated. It was found that the AAAS tested acted as surface-active antifungal agents when introduced in the paper, significantly reducing the growth of Aspergillus niger and Paecilomyces variotii, two fungal species commonly found in storage areas of libraries and archives. The AAAS which seemed the most efficient in preventing the fungal development was 3-aminopropylmethyldimethoxysilane (AMDES), functionalised with a primary amine. The effect was significant in the different papers tested which demonstrated the protection against the proliferation of filamentous fungi in vitro for papers treated with AMDES. The higher concentration of AMDES inside the paper proved to be the most effective. The highest efficiency was reached for AAAS uptakes around 6%. At this concentration the sporulation of the two strains was inhibited and the development of A. niger mycelia was highly reduced.