Ana Teresa de Carvalho Correa de Oliveira

O lugar das matemáticas na Licenciatura em Matemática: que matemáticas e que práticas formativas?

This article is an essay that aims to problematize and discuss the place of mathematics in Mathematics Teacher Degree programs. It is organized around two basic questions: what are we talking about when we refer to mathematics that teachers need to know well for teaching? Which educational practices can contribute to the appropriation of this fundamental mathematics by future teachers for their professional work? To find the answers, different social practices of mathematics educators were problematized seeking clues in those practices regarding the kind of mathematical knowledge required and mobilized in their work. After that, some historical attempts to address the problem of mathematical education of teachers were reviewed, with Felix Klein, Richard Courant and Bento de Jesus Caraca as references, and some Brazilian and international research regarding the training of mathematics teachers. Based on these studies, this article highlights the existence, in the initial training of mathematics teachers, of a quasi trichotomy among academic mathematics, didactic-pedagogic content and teaching practice in schools. To break with this trichotomic tradition some changes are suggested regarding the practice and research on teacher education. For example, teacher training in mathematics must be guided by the different social practices of mathematics educators. These practices can to be adopted in training and projects in which undergraduates can to be integrated, making contrasts, discussions and investigations about the relationships among their undergraduate training in mathematics, their pedagogical-didactic training related to the content, and the complexity of school practices.

Manutenção em laboratório de Anopheles albitarsis e Anopheles aquasalis por copulacao induzida

Many species of mosquitoes are unsuited to life in a laboratory because they fail to copulate in cages. This situation may be largely eliminated by the technique in current use for manually inducing inseminations as outlined. We have used this technique for the first time in relation to Anopheles albitarsis and A. aquasalis, species of malaria vectors which are difficult to mate spontaneously in captivity. The pre-mating age of the males and the temperature at which they are held affect the ability of male to transfer sperm. Mating males 8 to 14 days old with females at any age, resulted in a high order of insemination. Temperature of 25°C and humidity of 80% RH enhanced the degree of insemination.

Solid-state fermentation of co-products from palm oil processing: Production of lipase and xylanase and effects on chemical composition

Abstract The palm oil industry generates large amounts of lignocellulosic co-products. Palm kernel cake (PKC) and palm pressed fibre (PPF) have nutritional limitations as ingredients in animal feed, and are therefore little used. Solid-state fermentation (SSF) is one alternative treatment to improve the nutritional value of these co-products and to increase their possible use, through the production of enzymes such as lipases and xylanases. These enzymes can reduce the contents of undesirable compounds, such as lipids, and degrade some components of the fibres to improve the digestibility of these co-products. The fungi Aspergillus niger, Aspergillus oryzae and Aspergillus awamori were able to grow in PKC/PPF (40/60 w/w) culture medium by SSF, and to produce xylanase and lipase. A. niger showed the highest lipase activity (20.7 U g−1) at 72 h. A. awamori higher xylanase activity than the other fungi at all culture periods, reaching a maximum activity of 134.2 U g−1 at 72 h. The unfermented co-products contained 7.49% lipids and 7.38% non-fibrous carbohydrates (NFC). Lipase produced by these fungi during SSF reduced the lipid content by 36%, 40% and 45% for A. oryzae, A. awamori and A. niger, respectively. The production of xylanases by SSF probably increased the NFC contents by up to 64%. Fermented solids with A. oryzae and A. awamori had the highest levels of NFC, 20.3% and 13.94%, respectively, which improved the nutritional value of these co-products.