Summary We describe the maize supply chain in Portugal for maize bread, a traditional bread type. As this bread is not labelled as ‘contains genetically modified organisms’ it should not contain more than 0.9 per cent genetically modified ingredients. On the basis of interviews we identify a general lack of documentation of the presence or absence of genetically modified ingredients along the complete supply chain (farmers, traders, mills and bakeries). Part of this deficiency is probably driven by a lack of awareness of the labelling rules at the end of the supply chain. A test of maize bread showed that more than 40 per cent of breads were indeed over the labelling threshold, and should be labelled. This includes GM maize that is not cultivated in the EU and enters the supply chain via international trade. We conclude that the realisation of coexistence and segregation requires involvement of the full supply chain, rather than just segregation at the start, if bread is to be sold with a GMO content below the 0.9 per cent threshold level. Alternatively, retailers can label their bread. This might be a cheaper solution and as a study from Switzerland shows may not result in adverse consumer reaction.

ResumoEste artigo debruça-se sobre o papel das TIC no desenvolvimento de aspetos do conhecimento didático (tipo de tarefas e formas de comunicação) e da capacidade reflexiva de futuros professores de Matemática durante o seu estágio. O estudo envolve três estagiários colocados em escolas diferentes. Os dados foram recolhidos através de duas entrevistas a cada estagiário (uma no início e outra no final do estágio) e da análise documental (reflexão de aulas e mensagens de e mail e do fórum). As TIC permitiram a partilha e a discussão de situações da sala de aula, o trabalho conjunto entre orientadores e estagiários, o que contribuiu para o desenvolvimento do conhecimento didático e da capacidade reflexiva dos estagiários. Estes usaram diferentes tipos de tarefas e promoveram formas de comunicação para além da unidirecional. A interpretação, problematização e reconstrução de alguns momentos contribuíram para verem a própria prática como fonte para aprender a ensinar.

We discuss how collaborative relationships may develop in lesson study groups, paying attention to the critical incidents that may arise. This qualitative research study is based on two lesson studies with primary and middle school teachers. Data were collected through a researcher’s journal, audio records of working sessions, video records of research lessons, post lesson reflections, and individual interviews. In the two cases, the collaborative relationships developed as common aims and ways of productive joint work emerged. In the development of these relationships, several critical incidents had a strong influence, in some cases positive and in other cases negative.