The aim of this study was to evaluate the performance of three Nile tilapia strains in Brazil compared to Genomar Supreme™ Generation 24 from the Philippines. Tilapia fingerlings, male population, of approximately 8 g which were cultivated in water recirculation systems containing 0.5 m 3 tanks, density of 60 fish m −3 , with four replicates (tanks). The fish will be fed three times a day with the same commercial feed for each particular growth phase according to biomass in each tank. Five fish from each tank were sampled at the start and 60th, 120th, 180th and 240th days of cultivation. They were determined the weight gain, feed conversion and homogeneity of batch in each period. The Gompertz model given by y = Ae (−Be −Kx) was fit and it was calculated the absolute and relative growth rate. The weight and age at inflection point were calculated too. The improvement programme from Genomar in the Philippines brings tilapia strain with better growth rate and performance when compared with the one commercialized in Brazil. This Philippine strain constitutes an important potential to improve tilapia farm in Brazil. However, the use of this genetics needs to be accomplished in this country.

This study aimed to evaluate the growth and performance of genetically improved tilapia reared at different temperatures. Four hundred and eighty fingerlings of Genomar Supreme Tilapia, GST (8.39 ± 0.60 g) were equally separated into three indoor water recirculation systems maintained at 22, 26 and 30 ºC. Each of four tanks contained 500 liters with 40 fish per tank in natural photoperiod. The fish were fed ad libitum with the same feed for each growth phase, weighing the total feed supplied. After 30 min of feeding, leftover feed was collected, dried in an oven and weighed. Ten fish from each tank were weighed at days 1, 30, 60, 90, 120, 150, 180 and 210. Survival, weight gain, feed conversion and feed intake in each period were determined. Fish reared at 30 ºC and 26 ºC showed a higher specific growth rate than that of fish reared at 22ºC (P≤0.05). Feed intake increased along temperature and feed conversion and was poorest in fish reared at 26ºC (P≤0.05). Final fish weight estimates at day 210 by the Gompertz model were 597.84, 819.26 and 1079.39 g for 22, 26 and 30 ºC, respectively. At 30 ºC, fish had a higher absolute growth rate (7.76 g day−1) and lower weight (459.30 g) and age (95.85 days) at the inflection point. Tilapia at 22 ºC had a higher weight (539.57 g) and age (197 days) and lower absolute growth rate (4.52 g day−1). It was concluded that GST tilapia can potentially improve aquaculture in all Brazilian regions based on different rearing temperatures.

O objetivo deste trabalho foi identificar e analisar os elementos da base de conhecimentos para o ensino, fundamentalmente aqueles relacionados aos Conhecimentos Pedagógicos de Conteúdo que são expressos nas interações entre uma professora da Educação Básica, um licenciando em física e um professor formador, participantes de um Grupo de Planejamento Conjunto (GPC). Esse GPC planejou e executou uma atividade experimental investigativa sobre a temática “energia e suas transformações”. Todas as reuniões entre os membros do GPC foram gravadas em áudio e posteriormente transcritas para serem analisadas. Os resultados foram agrupados em categorias e analisados sob os fundamentos de referenciais que versam sobre a base de conhecimentos para o ensino de professores e os conhecimentos pedagógicos de conteúdo. Observou-se também a relação dos conhecimentos encontrados com o GPC e com a metodologia das atividades experimentais investigativas. As análises demonstram o potencial da formação de grupos de planejamento conjunto na ocorrência desses conhecimentos, com ênfase nos conhecimentos de conteúdo e pedagógicos de conteúdo, e contém elementos para a discussão sobre formas de abordagem formativas que contemplem o desenvolvimento da base de conhecimentos para o ensino.

Neste artigo, o autor analisa a cena de jazz da cidade de São Paulo. Para isso, foram investigados bares especializados em jazz. Após apresentar as caracterí­sticas da cena, são levantadas algumas situações de conflito, resultantes de interesses divergentes dos participantes. Ao final, baseado em observações de Ruth Finnegan, discute-se a relação entre músico amador e músico profissional e a situação dos jazzistas nesse contexto.