RESUMO Interesses e relações de poder ocorrem na avaliação de trabalhos, em processo editorial realizado em periódicos científicos. Tais processos tornam-se mais evidentes em meio a controvérsias científicas. Argumentamos que a atuação de editoras e editores de periódicos é fundamental para compreender como interesses e relações de poder interferem na política editorial, em disputas por estabelecimento ou encerramento de controvérsias. O artigo analisa como políticas editoriais influenciam controvérsias científicas. A controvérsia proposta é o debate sobre o papel do campesinato na questão agrária, disputa orientada por diferentes pressupostos, e localizada principalmente no programa de pesquisa marxista. O corpus de pesquisa é formado por artigos, editoriais, livros e resenhas publicados em três periódicos internacionais de Estudos Agrários: The Journal of Peasant Studies, Journal of Agrarian Change e Agrarian South: Journal of Political Economy, além de entrevistas semiestruturadas com editores. Analisaram-se os conteúdos, a recorrência de temas e a atuação de editoras e editores no fluxo editorial. Diferentes modos de atuação de editoras e editores operam para omitir ou evidenciar posições na controvérsia, direcionando-a para o encerramento ou a continuidade do debate.

ABSTRACT Situations demonstrate interests and power relations in evaluation of papers in scientific controversies in editorial process in journals. We argue the role of journal editors is fundamental to understanding editorial policy in situations of opening and closing controversies. The article analyzes how editorial policies interfere with scientific controversies. The controversy analyzed is the dispute over the role of the peasantry in the agrarian question, debate guided by different assumptions, carried out mainly in the Marxist research program. The research corpus consisted of articles, editorials, books and book reviews published in three international journals of Agrarian Studies: The Journal of Peasant Studies, Journal of Agrarian Change and Agrarian South: Journal of Political Economy, and semi-structured interviews with editors. Contents, recurrence of themes and the performance of editors in the editorial process were analyzed. Different ways of action by editors operate to omit or highlight positions in the controversy, guiding to the closure or continuity of the debate.

Abstract: The objective of this work was to obtain, through the tree pruning pyrolysis, coal to be used in the removal of pollutants present in gray waters. The coal obtained during the process was used in a gray water filtration column and dye adsorption test. In this investigation it was proposed the treatment of gray water by the following series steps: (a) coagulation/ flocculation, (b) decantation, (c) sand filtration and (d) coal filtration column. The maximum coal yield was 60.10% obtained at 360 ºC and heating rate of 30 ºC/min. The gray water polishing using the coal obtained from the tree pruning pyrolysis process was efficient in the removal of the studied analytical parameters. For turbidity, COD, total solids and residual chlorine parameters, the removal values were 99, 98, 71 and 100 %, respectively. The charcoal from the filtration column was responsible for removing organ matter of gray water.

The use of digital image analysis as an analytical tool is a reality nowadays, and the use of smartphones stands out due to its high accessibility and practicality. Ascorbic acid (AA) is a natural and essential vitamin available as a supplement as a result of its use in preventing and treating several pathologies. This paper reports a simple, fast and low cost method using smartphone image analysis for quantification of AA based on its interfering effect in the enzymatic colorimetric detection of glucose. Commercial vitamin C tablets were used as prediction set for AA quantification, showing very satisfactory results (relative errors < 4%), where no statistical difference at a 95% confidence level was observed between the AA content estimated by the imaging method and the labeled reference values. As advantages, this method does not use expensive reagents neither laborious procedures to carry out the analysis.

O Índice de Área Foliar (IAF) é determinante nos processos de trocas de massa e energia nos ecossistemas, sendo fundamental para o entendimento das mudanças no clima regional e na dinâmica do ecossistema. O objetivo deste trabalho foi analisar, por meio da geoestatística, a variabilidade e dependência espacial dos valores de índice de área foliar (IAF) em áreas naturais de campo 'baixo', campo 'alto' e floresta de transição no Sul do Amazonas. Os valores de IAF foram determinados numa malha regular com 33 pontos para cada área estudada, e a aquisição dos dados foi feita pelo analisador de dossel LAI-2000, que permite se calcular a estrutura da vegetação com base na radiação que penetra na copa das árvores. Os valores médios do IAF variaram de acordo com a área estudada, com maiores valores na floresta (4,42 m²m-2), seguida pelo campo alto (2,03 m²m-2) e campo baixo (1,72 m²m-2). Em todas as áreas os valores de IAF mostraram dependência espacial com o uso da krigagem entre as amostras e apresentam distribuição espacial diferenciada em cada área estudada: o grau de dependência espacial foi moderado na floresta de transição e fraco para os campos naturais, sendo que no campo alto a distância limite em que os pontos estão correlacionados é de 35,3 m. No mapa de krigagem foi possível observar manchas com valores altos e baixos distribuídos de forma diferenciada entre as áreas estudadas.

The Leaf Area Index (LAI) has strong influence on ecosystems' energy and mass exchange and is fundamental to the understanding of regional climate changes and ecosystem dynamics. The main goal of this work was to establish, based on geostatistical analyses, the variability and spatial dependence of LAI in the natural fields and transitional forest in southern Amazonas State, in Brazil. The LAI was measured in a regular grid with 33 points at each studied area. Field measurements were done using the canopy analyser LAI-2000, which calculates the structure of the vegetation based on the radiation beneath the tree canopy. The average values of LAI varied according to the studied sites: the highest values were found in the transitional forest (4.42 m²m-2), followed by the high (2.03 m²m-2) and low (1.72 m²m-2) natural fields. All studied sites showed spatial dependence according to the kriging methods, but with different degrees of dependence: spatial dependence was moderate at the transition forest and weak at the natural fields. In the more arboreal open field, the maximum limit at which the points are correlated reached a distance of 35.3 m. The kriging maps proved to be very important tools for describing the spatial distribution of LAI in the Amazon.

Bioorganic and biological chemistry have been found to be highly motivating to undergraduate students and in this context, biochemical blood parameter analysis emerges as highly attractive content. In this proposal, several aspects related to analyses of glucose, cholesterol and triglycerides using the enzymatic colorimetric method were involved, and the findings have at least two relevant implications: i) introducing students to connections between organic chemistry and biology based on enzymatic processes, including reactivity and mechanistic aspects; ii) performing a micro scale bioassay analysis. The proposal requires two theoretical classes (2 h per class) and one practical class (4 h).