Question How reliable is the process of delimiting plant species by morphotyping sterile specimens from a highly diverse Amazonian forest plot? Location Biological Dynamics of Forest Fragments Project (BDFFP), Central Amazon, Manaus, Brazil. Methods A taxonomic exercise was conducted during a Center for Tropical Forest Science (CTFS) Taxonomy Workshop held in Manaus in April 2011, using specimens collected in a 25‐ha forest plot. The plant species from this plot had been previously delimited by morphotyping of ca. 80 000 sterile specimens, a process that resulted in the recognition of 115 cases (accounting for 38% of all trees) in which species delimitation was problematic. For the workshop, we selected a subsample of specimens for eight of these difficult cases (taxonomic groups/complexes) and asked 14 participants with different levels of botanical training to independently sort these specimens into morphospecies. We then compared the classifications made by all participants and explored correlations between botanical training and plant classification. Results The classification of specimens into morphospecies was highly variable among participants, except for one taxonomic group/complex, for which the median pair‐wise similarity was 95%. For the other seven taxonomic groups/complexes, median pair‐wise similarity values ranged from 52% to 67%. Training did not increase the similarity in the definition of morphospecies except for two taxonomic groups/complexes, for which there was higher congruence between the classifications made by participants with a high level of botanical training than in comparisons that included less‐experienced participants. The total number of morphospecies defined by participants was highly variable for all taxonomic groups/complexes, with the total number varying from 12 to 46 (a 383% difference). Conclusions Local plant species delimitation by morphotyping sterile specimens is prone to large uncertainties, and botanical training may not reduce them. We argue that uncertainty in species delimitation should be explicitly considered in plant biodiversity inventories as diversity estimates may be strongly affected by such uncertainties. We recommend that species delimitation and identification be treated as separate processes and that difficulties be explicitly recorded, so as to permit error estimates and the refinement of taxonomic data.

Adolescents in the most favored regions (especially students in private schools in the region) had a prevalence of being overweight and suffering from obesity.

Abstract. The aim of this paper is to propose a conceptual model of change that can facilitate the teaching and learning process through a collaborative learning model supported by computer based on a model of constructivist education and the 5 C's methodology (SALES, 2005 IntroduçãoA difusão da tecnologia digital nas últimas décadas do século XX proporcionou uma mudança radical na educação. Alunos contemporâneos do ensino médio representam a geração que cresceu cercado pelas novas tecnologias. Eles passam a maior parte do tempo usando computadores, vídeo games, câmeras de vídeo, telefones celulares e todas as outras ferramentas da era digital.Esse quadro é representativo do avanço da das Tecnologias Digitais de Informação e Comunicação (TDIC) tanto no que concerne às descobertas nessa área como no que diz respeito à propagação de seu uso. Como consequência desse cenário, surge a necessidade de que os espaços de aprendizagem, sejam na escola ou fora dela, apropriem-se de seus recursos, tais como os objetos de aprendizagem (OA) e os ambientes virtuais.

RESUMO1 Recebido para publicação em 28/06/99 e na forma revisada em 13/09/99. A aplicação de herbicidas em pós-emergência inicial e em pós-emergência dirigida pode causar injúrias às plantas de milho, quando estas são atingidas por produtos não totalmente seletivos. Como esses herbicidas são basicamente bloqueadores de processos metabólicos, surge a dúvida de quais serão os efeitos dessas injúrias na produção final de grãos de milho. Assim, o objetivo deste trabalho foi estudar o efeito da fitotoxidade causada pela aplicação de herbicidas na fase inicial e na pós-emergência tardia da cultura e o seu efeito na produção de grãos. Foi utilizado o híbrido BRS 3123, em 12 tratamentos repetidos 4 vezes. Esses tratamentos consistiram da aplicação dos seguintes herbicidas: cyanazine + simazine + assist, aplicados nos estádios de crescimentos de 4 e 6 folhas e paraquat + extravon e ametryn + assist, aplicados no estádio de 12 folhas, em jato dirigido. Foram incluídos também testemunhas com e sem capinas, além dos tratamentos com retirada mecânica das folhas do 1 o e do 1 o ao 3 o pares de folha. Foram avaliados: área foliar, matéria seca, teor de clorofila nas folhas, altura da planta e da inserção de espigas, diâmetro do colmo, índice de espigas, peso de 1000 grãos e produção de grãos. Observou-se que no no primeiro ano agrícola (94/95), as variáveis de crescimento não foram afetadas pelos tratamentos, ao passo que no ano seguinte, o melhor desenvolvimento das plantas foi obtido com a aplicação de cyanazine + simazine, enquanto que paraquat + extravon, ametryn + assist e testemunha sem capina, (devido ao efeito de matocompetição), resultaram nos piores tratamentos até a floração do milho. A maior produção de espigas e grãos no primeiro ano foi obtida com o tratamento cyanazine + simazine + assist, enquanto que, no segundo ano, paraquat + extravon e ametryn + assist proporcionaram as maiores produções, apesar das injúrias observadas na área foliar.Palavras chave: Injúria, fotoassimilados, Zea mays. ABSTRACT Toxicity of herbicides post emergents at maize crop initial phaseHerbicide application at post emergence stage may cause injuries to maize plants, when these plants are reached randomly by non selective products. Since these herbicides act basically blocking metabolic processes , the question which has been raised is concerned what are the effects that these injuries will result in the grain production. Therefore the objective of this work was to study the phytotoxic effects caused by the application of herbicides at the initial phase and at late post emergency stage of the crop and its effect in the grain production. It was used the hybrid BRS 3123, with 12 treatments in 4 replications. These treatments were performed by the combination of the application of the following herbicides: cyanazine + simazine with

The aim of this work was to evaluate the organogenesis of Marubakaido apple rootstock under different aluminium concentratons. The explants were calli derived from apple internodes treated with either 2,4-dichlorophenoxyacetic acid or pichloram at 0.5 and 1.0 μM and under five different aluminium concentrations (0, 5, 10, 15, 20 mg/L). These calli were then treated with aluminium at 0, 5, 10, 15, and 20 mg/L. It was observed shoot regeneration only for those calli previously treated with pichloram. There were no significant difference among the aluminium concentrations.