Exp\'erimentation d'une ressource pour une situation de recherche et de preuve entre pairs

This paper is about an experiment with the goal of testing a primary teacher's resource. This is the next part of a research presented at EMF2009. This resource must help a teacher to practice a research and proof activity between peers with her pupils even she had never done this before. The paper presents the problems given by this project and describes the means to build the resource and the methodology of the experiment with some classmates. The results are given illustrating the complexity of the underlying process.Comment: Espace math\'ematique francophone, Gen\`eve : Suisse (2012

Recursos didácticos del y para el profesor de matemáticas. Una experiencia de formación continua en la modalidad en línea y a distancia

Dentro de un programa de maestría en matemática educativa en la modalidad en línea y a distancia del Instituto Politécnico Nacional de México, la cual es cursada por profesores de matemáticas en servicio, se realizó un curso cuyo objetivo principal era diseñar recursos didácticos para el profesor de matemáticas. El curso se basó principalmente en el trabajo de Georget (2009), en el cual se presentan herramientas que permiten proponer y evaluar un recurso didáctico. En este reporte se presenta un primer análisis de algunos de los elementos que conformaron dicho curso así como reflexiones sobre su organización didáctica y la manera en que ésta podría modificarse

Pour une étude didactique des collectifs d’enseignants des mathématiques

O trabalho científico em forma de artigo deve conter um resumo em português e o resumo correspondente em língua estrangeira: inglês, francês ou espanhol, com um máximo de 15 linhas em espaço simples e uma relação de cinco palavras-chave descritoras do conteúdo do trabalho apresentadas em português e em língua estrangeira: inglês, francês ou espanhol. Não usar tradutor automático. Recomenda-se passar por revisão de profissional especializado. Este resumo deve ser escrito em fonte Times New Roman, 11pts, em espaço simples sem recuo de parágrafo

G x E interactions on yield and quality in Coffea arabica: New F1 hybrids outperform American cultivars

Conventional American cultivars of coffee are no longer adapted to global warming. Finding highly productive and stable cultivars in different environments without neglecting quality characteristics has become a priority for breeders. In this study, new Arabica F1 hybrids clones were compared to conventional American varieties in seven contrasting environments, for yield, rust incidence and volume of the canopy. The quality was assessed through size, weight of 100 beans, biochemical analysis (24 aroma precursors and 31 volatiles compounds) and sensory analysis. Conventional varieties were the least productive, producing 50% less than the best hybrid. The AMMI model analysis pointed out five hybrids as the most stable and productive. Two F1 hybrids clones, H1-Centroamericano and H16-Mundo Maya, were superior to the most planted American cultivar in Latin and Central America showing a high yield performance and stability performance. H1-Centroamerica and Starmaya contain more d-limonene than Caturra, while Starmaya contain more 3-methylbutanoic acid than the control. Those two latter volatiles compounds are linked with good cup quality in previous studies. In terms of sensory analysis, Starmaya and H1-Centroamericano scored better than control

TELMA Cross Experiment Guidelines

Cerulli, M., Pedemonte, B., Robotti, E. (eds.). Internal Report, R.I. 01/07, I.T.D. - C.N.R., GenovaThis document contains the guidelines developed by members of TELMA as a means for planning, conducting, and analysing a cross experiment aimed at contributing to the construction of a shared research perspective among TELMA teams . This is the product of the PhD students and young researchers that brought forward the whole activity. The actual experimental phase was proceeded by a reflective phase in which an agreement was achieved on what research questions to address during the experiment. On this basis the first version of the guidelines document was built, containing all the research questions to be addressed, but also the experimental plans for each team. This included the employed didactical functionalities of the considered ICT tools, indications of the experimental settings, and the methods of data collection and analysis. During the whole experimental phase, the document was constantly updated, and shared among the involved persons which were periodically required to compare the different activities and reflections brought forward by all the teams

Coffee Somatic Embryogenesis: How Did Research, Experience Gained and Innovations Promote the Commercial Propagation of Elite Clones From the Two Cultivated Species?

Since the 1990s, somatic embryogenesis (SE) has enabled the propagation of selected varieties, Arabica F1 hybrid and Robusta clones, originating from the two cultivated coffee species, Coffea arabica and Coffea canephora, respectively. This paper shows how mostly empirical research has led to successful industrial transfers launched in the 2000s in Latin America, Africa, and Asia. Coffee SE can be considered as a model for other woody perennial crops for the following reasons: (i) a high biological efficiency has been demonstrated for propagated varieties at all developmental stages, and (ii) somaclonal variation is understood and mastered thanks to intensive research combining molecular markers and field observations. Coffee SE is also a useful model given the strong economic constraints that are specific to this species. In brief, SE faced four difficulties: (i) the high cost of SE derived plants compared to the cost of seedlings of conventional varieties, (ii) the logistic problems involved in reaching small-scale coffee growers, (iii) the need for certification, and (iv) the lack of solvency among small-scale producers. Nursery activities were professionalized by introducing varietal certification, quality control with regard to horticultural problems and somaclonal variation, and sanitary control for Xylella fastidiosa. In addition, different technology transfers were made to ensure worldwide dissemination of improved F1 Arabica hybrids and Robusta clones. Innovations have been decisive for successful scaling-up and reduction of production costs, such as the development of temporary immersion bioreactors for the mass production of pre-germinated embryos, their direct sowing on horticultural soil, and the propagation of rejuvenated SE plants by rooted mini-cuttings. Today, SE is a powerful tool that is widely used in coffee for biotechnological applications including propagation and genetic transformation. Basic research has recently started taking advantage of optimized SE protocols. Based on -omics methodologies, research aims to decipher the molecular events involved in the key developmental switches of coffee SE. In parallel, a high-throughput screening of active molecules on SE appears to be a promising tool to speed-up the optimization of SE protocols

L-Ilf3 and L-NF90 Traffic to the Nucleolus Granular Component: Alternatively-Spliced Exon 3 Encodes a Nucleolar Localization Motif

Ilf3 and NF90, two proteins containing double-stranded RNA-binding domains, are generated by alternative splicing and involved in several functions. Their heterogeneity results from posttranscriptional and posttranslational modifications. Alternative splicing of exon 3, coding for a 13 aa N-terminal motif, generates for each protein a long and short isoforms. Subcellular fractionation and localization of recombinant proteins showed that this motif acts as a nucleolar localization signal. Deletion and substitution mutants identified four arginines, essential for nucleolar targeting, and three histidines to stabilize the proteins within the nucleolus. The short isoforms are never found in the nucleoli, whereas the long isoforms are present in the nucleoplasm and the nucleoli. For Ilf3, only the posttranslationally-unmodified long isoform is nucleolar, suggesting that this nucleolar targeting is abrogated by posttranslational modifications. Confocal microscopy and FRAP experiments have shown that the long Ilf3 isoform localizes to the granular component of the nucleolus, and that L-Ilf3 and L-NF90 exchange rapidly between nucleoli. The presence of this 13 aminoacid motif, combined with posttranslational modifications, is responsible for the differences in Ilf3 and NF90 isoforms subcellular localizations. The protein polymorphism of Ilf3/NF90 and the various subcellular localizations of their isoforms may partially explain the various functions previously reported for these proteins

Activités de recherche et de preuve entre pairs à l'école élémentaire : perspectives ouvertes par les communautés de pratique d'enseignants

This thesis is about research and proof activities between peers (RPP) in mathematics classrooms and about the ways of promoting their implementation at the end of the primary school. It is based on classical tools in mathematics education (Robert & Rogalski 2002). It is also enriched by the theory of communities of practice (CoP) (Wenger 1998) which is presented and discussed, and by the ergonomic approach of computer supported learning environments, whose use is enlarged to resources for teachers. The potentials of research, debate, resistance, dynamic and didactic resistance are defined to characterize more precisely RPP activities. A comparative analysis of existing experiments and teaching resources is presented, together with a literature study about the still limited exploitation of the theory of CoP in mathematics education. An experiment, held during 3 years and based on a teachers' CoP, has permitted to operationalize this theory in an original way (participation/reification, boundary objet, trajectory) with the goal of favouring evolutions of practice. Some open problems already experimented were presented to the teachers. Resource ergonomics was refined to solve the incompleteness paradox of resources concerning the quantity of information usable and acceptable by a teacher. The analyses developed show the interest of the proposed approach and possibilities for its optimization. They also show that the complexity of RPP activities can explain their limited diffusion within teachers' practices.La thèse traite des activités de recherche et de preuve entre pairs (RPP) en classe de mathématiques et des moyens de favoriser leur mise en œuvre à la fin de l'école primaire. Le travail mené s'appuie sur des outils classiques en didactique des mathématiques (Robert & Rogalski 2002). Il est enrichi par la théorie des communautés de pratique (CoP) (Wenger 1998) qui est présentée et discutée, et par des concepts d'ergonomie des environnements informatiques pour l'apprentissage humain dont l'usage est élargi aux ressources destinées aux enseignants. Les potentiels de recherche, de débat, de résistance, de résistance dynamique, didactique, sont définis pour mieux caractériser les activités RPP. Une analyse comparée d'expériences antérieures et de ressources destinées aux enseignants est présentée, ainsi qu'une étude de la littérature concernant l'exploitation, encore limitée, de la théorie des CoP en didactique des mathématiques. Une expérimentation, menée sur 3 années et s'appuyant sur une CoP d'enseignants, a permis d'opérationnaliser cette théorie de manière nouvelle (participation/réification, objet frontière, courtage, trajectoire) dans le but de favoriser des évolutions de pratique. Des ressources présentaient aux enseignants des problèmes ouverts déjà expérimentés. Leur ergonomie était affinée pour résoudre le paradoxe d'incomplétude des ressources concernant la quantité d'information utilisable et acceptable par un enseignant. Les analyses ont montré l'intérêt de l'approche proposée, les possibilités de son optimisation, et le fait que la complexité des activités RPP peut largement expliquer leur faible diffusion dans les pratiques enseignantes

Une étude des évolutions pédagogiques et didactiques dans les colloques CETSIS

International audienceDes enseignants et chercheurs de l'enseignement supérieur en électronique, électrotechnique et automatique se réunissent en colloques pour échanger sur leurs pratiques pédagogiques. Les organisateurs du colloque CETSIS 2013 ont « commandé » une expertise de cette pratique communautaire à des chercheurs en didactiques. Nous rendons compte de la construction de cette expertise et de ses résultats. Les colloques atteignent l’objectif qui leur est fixé, d’être un lieu de diffusion, d’échange d’expériences et de compétences. Ils tendent aussi à poursuivre implicitement d'autres objectifs. Une partie des enquêtés est désireuse de s’orienter vers des pratiques de recherche en didactique et en pédagogie dans le domaine EEA. Le morcellement du domaine en petites spécialités montre la richesse et la difficulté de cette orientation. Nous suggérons quelques développements de nature à soutenir cette orientation et ainsi compléter la richesse des colloques CETSIS