Dietary recommendations: comparing dietary guidelines from Brazil and the United States Recomendações dietéticas: comparação entre os guias alimentares brasileiro e americano

The Brazilian dietary guidelines are based in part on mainstream United States' recommendations, in spite of the criticisms and shortcomings of the American guidelines. In this paper, Brazilian food guidelines are summarized and discussed in comparison with the USA recommendations. American and Brazilian dietary recommendations are quite similar in many aspects, particularly those related to variety in the diet, the importance of physical activity and weight management. Different to American guidelines, those from Brazil advise people to choose fresh foods, to prefer healthier types of fat, to limit trans fat intake and to eat good sources of protein, but does not recommend the consumption of whole grains. Besides the challenges related to their implementation, indicators for the evaluation of the effectiveness of these guidelines should be established from the beginning, particularly those related to changes in dietary habits and the prevalence of obesity.<br>O guia alimentar brasileiro é baseado parcialmente nas recomendações americanas a despeito das críticas e problemas identificados no documento dos Estados Unidos. Neste artigo, as recomendações alimentares para o Brasil são resumidas e discutidas em comparação com as recomendações estadunidenses. Os guias alimentares brasileiro e americano são bastante similares em diversos aspectos, particularmente aqueles relacionados com a variação da dieta, a importância da atividade física e o gerenciamento do peso. Diferentemente dos Estados Unidos, o guia brasileiro estimula o consumo de alimentos frescos, aconselha o uso de fontes saudáveis de gorduras, a limitação do consumo de gordura trans, o consumo de boas fontes de proteínas, mas não indica o consumo de grãos integrais. Além dos desafios relacionados com a sua implantação, os indicadores para a avaliação da eficácia dos guias alimentares devem ser estabelecidos desde sua implantação, particularmente, os relacionados a mudanças nos hábitos alimentares e à prevalência da obesidade

Kinetochore kinesin CENP-E is a processive bi-directional tracker of dynamic microtubule tips

During vertebrate mitosis, the centromere-associated kinesin CENP-E transports misaligned chromosomes to the plus ends of spindle microtubules. Subsequently, the kinetochores that form at the centromeres establish stable associations with microtubule ends, which assemble and disassemble dynamically. Here we provide evidence that after chromosomes have congressed and bi-oriented, the CENP-E motor continues to play an active role at kinetochores, enhancing their links with dynamic microtubule ends. Using a combination of single molecule approaches and laser trapping in vitro we demonstrate that once reaching microtubule ends, CENP-E converts from a lateral transporter into a microtubule tip-tracker which maintains association with both assembling and disassembling microtubule tips. Computational modeling of this behavior supports our proposal that CENP-E tip-tracks bi-directionally via a “tethered motor” mechanism, which relies on both the motor and tail domains of CENP-E. Our results provide a molecular framework for CENP-E's contribution to the stability of attachments between kinetochores and dynamic microtubule ends