Notas sobre os historiadores e suas fontes

The aim of this text is to discuss the different meanings attributed to notions of historical sources and documents from the nineteenth century, when history was constituted as a discipline. It is important to point out the centrality of this issue to the different conceptions about the production of knowledge in this field.

A importância da pesquisa de fontes para os estudos históricos

The importance of research sources for historical studies. In our text we try to call the attention to the fact that, concerning the sources, the most important aspect is the researcher who considers them. This consideration is a product of history, thus in each period and according to his social and political status, the researcher will conceive the sources in a particular way. Therefore, there is no single way to deal with the sources, which is unrelated to how the researcher behaves in relation to contemporary issues.

Estudos sobre o Brasil Colonial: arquivos e fontes

The information technology and the increasing interest in the American Latin studies, especially about Brazil, are the objective of these reflections. In the research about the colonial period in Brazil, a group of works, systematized and divulged by electronic means, beyond the usual sources – Portuguese, Italian and Brazilian Universities and Institutes – are from Europe and North America, and its access is facilitated by the worldwide network. Platforms and collections such as Europeana and others less known constitute important sources to the studies of this field. We will comment here some fundamentals to contribute to the subject sources of colonial Brazil.

Annona emarginata (Schltdl.) H. Rainer 'araticum-de-terra-fria' cultivada com variação de nitrogênio: produtividade e perfil químico dos voláteis foliares

Pós-graduação em Agronomia (Horticultura) - FCA

Potencial de resíduos agroindustriais como fontes de compostos bioativos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fontes potássicas na produção do pimenteiro em substrato fertirrigado

Pós-graduação em Agronomia (Horticultura) - FCA

Resposta da terceira soqueira da cana-de-açúcar à aplicação de nitrogênio na presença e ausência de silício

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Análise econômica do milho em sucessão a diferentes adubos verdes, manejos do solo e doses de nitrogênio

Technologies that increase crop yields are possible when providing profitability to the producer. The objective of this study was to evaluate production costs and profitability of maize in production systems in Cerrado. The study was conducted in Selviria (Mato Grosso do Sul State), Brazil, in the years 2009/10 and 2010/11. The experiment was arranged in randomized blocks with four replications in factorial and mixed with tracks. We established 36 treatments, three green manures (Pennisetum glaucum, Crotalaria juncea and intercropping Pennisetum glaucum + Crotalaria juncea), three soil management practices (no-tillage system, "heavy disking" + "levelling disking" and "chisel plow" + "levelling disking") and four doses of N (0, 60, 90 and 120 kg ha(-1)). For economic analysis were estimated operational cost, the gross revenue obtained by the product of the productivity of the treatments and the value of corn (R$ 0,417 kg or R$ 25,00 sc(-1)) and the ratio revenue / cost of treatment. Whereas higher values (revenue/cost > 1) and lower (revenue/cost ratio < 1) as a parameter in the analysis of profitability, it can be concluded that corn under no-tillage had the highest profitability in succession to Pennisetum glaucum growing profitability with increasing N rates, in succession to Crotalaria juncea and in the absence of nitrogen application on the coverage achieved higher profitability compared to other treatments and in succession to the consortium Pennisetum glaucum + Crotalaria juncea doses of N was between 50 and 55 kg ha(-1) offer greater profitability to the cultivation of corn.

Características morfogênicas e estruturais da Brachiaria brizantha cv. Marandu submetida a diferentes doses de nitrogênio e alturas de resíduos

The objective of this study was to evaluate the rate of leaf appearance, leaf elongation rate, number of green leaves, length of blade and stem of Brachiaria brizantha cv. Marandu under different nitrogen levels and two residue heights. A randomized block design was used in a 4 x 2 factorial scheme, four doses of nitrogen (100, 200, 300 and 400 kg N ha(-1) year(-1)) and two residue heights (5 and 15 cm). There was significant interaction between residue height and nitrogen levels for leaf appearance rate of signal grass, which was influenced negatively and linearly by the residue heights being observed an average reduction of 28.20% from lower to higher residue. There was no interaction between the levels of nitrogen x residue height on the number of green leaves. The dosage that provided the highest stalk in the residue height of 5 cm was of 271.5 kg N ha(-1). An increase of 0.0745 cm tiller(-1) day(-1) for 1 kg of N ha(-1) applied to height of 15 cm of residue was observed. Nitrogen fertilization contributes positively to growth and development of rates of appearance and leaf extension. The management of pasture of Brachiaria brizantha cv. Marandu with 5 cm of residue and fertilization with 100 kg N ha(-1) provided better answer morphogenic traits.

Crescimento e produção do maracujazeiro amarelo, sob diferentes fontes e doses de fósforo em cobertura

Brazil is the largest world producer of yellow passion fruit, a fruit crop which is exigent in nutrients, although little studied in relation to phosphorus fertilizing, fundamental on plant establishment. An experiment was carried out during the period of March/2010 to April/2011 in Remigio County, Paraiba State, Brazil, in order to evaluate the vegetative and productive attributes of yellow passion fruit plants under different sources and doses of phosphorus. Treatments were distributed in randomized blocks in tree replications and twelve plants by plot using the factorial design 2 x 5 referring the sources of superphosphate triple and superphosphate simple at levels P2O5 of 0, 12, 18, 24 and 30 g cave(-1). The following variables were recorded: stem diameter, number of productive branches, number of fruits per plant, fruit mass and fruit yield. The sources and doses of phosphorus affected growth and fruit production of yellow passion plants. The triple superphosphate is the most phosphorus efficient source for growth and fruit production of yellow passion fruit. The triple superphosphate dose which promoted the maximum yield of yellow passion fruit is 42.86 g.

Sistemas de cultivo antecessores e doses de nitrogênio em cobertura no feijoeiro em plantio direto = cover crop systems and nitrogen topdressing on common bean in no tillage

The objective of this work was to evaluate the grass cover crop production in crop systems involving maize and Urochloa ruziziensis, and the influence of topdressing nitrogen rates in the yield and agronomic efficiency on common-bean cultivated in succession in no-tillage. The experiments were conducted in Jaboticabal-SP, in a eutrophic red latosol, in the second year of no-tillage system implementation. The IPR 139 cultivar was used in split plot design with three replications, in randomized block. The plots had been composed for three crop systems in the summer season, with maize exclusive, maize intercropped with U. ruziziensis and U. ruziziensis exclusive. The subplots had been constituted for five nitrogen rates (0, 40, 80, 120 and 160 kg ha(-1)), applied as topdressing at V4-4 in irrigated common-bean cultivated in the winter-spring season. The use of U. ruziziensis in crops systems, exclusive or intercropped with maize favors the grass cover crop production sufficiently to total soli surface covered, possibility similar grain yield compared to maize exclusive. The topdressing nitrogen application doesn't affect the common-bean yield in succession to maize and U. ruziziensis intercropped. The increase of nitrogen rates in common-bean in succession to maize exclusive improves the yield, although decreases the agronomic efficiency.

Ciclagem do nitrogênio relacionada ao sistema de produção

Pós-graduação em Agronomia (Agricultura) - FCA

Atributos químicos e físicos de um argissolo cultivado com Panicum maximum Jacq. cv. IPR-86 Milênio, sob lotação rotacionada e adubado com nitrogênio

A avaliação dos atributos químicos e físicos do solo é necessária em estudos que exploram intensivamente os sistemas de pastejo. No presente trabalho, objetivou-se avaliar as variações nos atributos físicos e químicos de um Argissolo cultivado com capim-milênio, sob pastejo, no intervalo compreendido entre outubro/2001 e maio/2002, no quinto ano de aplicação sucessiva das seguintes doses de N: 0, 150, 300 e 450 kg ha-1. Após os cinco anos de aplicação de 450 kg ha-1 de N, o teor de MO aumentou em 5 g dm-3, o que resultou em aumento da CTC. No período de outubro/2001 a maio/2002 houve diminuição nos valores de pH e de V com a aplicação de N. A densidade do solo variou pouco com a adubação nitrogenada; a percentagem de microporos aumentou e a de macroporos diminuiu na camada de 0-5 cm com o aumento das doses de N, mas a porosidade total permaneceu constante; e a resistência à penetração, quando o solo apresentava 90 g kg-1 de água, não foi afetada pelas doses de N e não foi restritiva ao crescimento das plantas.

Fluoretação das águas de abastecimento público em um município com diferentes fontes de captação

Maintaining the levels of fluoride ion in public water supply within the parameters of adequacy it becomes essential so the measure carries a greater impact on caries prevention and control, without increasing the prevalence of dental fluorosis. Thus, it is necessary a rigorous control of the process, avoiding the undesired effects at levels above recommended levels, as well as avoiding levels below the recommended that do not offer the highest benefit. The aim of this study was to analyze the content of fluoride in public water supply in the city of Birigui, SP, with different sources of supply, checking if the fluoride levels are within the recommended. The samples were collected monthly from points previously established, with the knowledge of the distribution network of water and identifying the amount and location of supply sources and water treatment plant. Analyses were performed in duplicate in the period from January to December of 2009, in the laboratory - NEPESCO - of the Dental School of Araçatuba, Univ Estadual Paulista – UNESP, using an ion analyzer coupled to a specific electrode for fluoride. Of the total samples (n = 512), 44% (n = 224) had adequate levels and 56% (n = 288) inadequate levels, 10% (n = 49) lower levels and 46% (n = 239) showed levels above the recommended. There were differences in results when comparing the analysis of different sources. The fluoride concentration in the majority of the samples from deep wells was classified as inadequate not offering the desired benefit, or exposing the population to the risk of dental fluorosis.

Estirpes de Leveduras Assimiladoras de Fontes de Carbono para Produção de Etanoll

Nas etapas fermentativas destinadas a produção de etanol, observa-se o desenvolvimento de diversos contaminantes, dentre elas as leveduras selvagens, que muitas vezes comprometem a produtividade e qualidade do produto final. Desta forma, o trabalho objetivou caracterizar, classificar e determinar marcadores genéticos-moleculares para 5 estirpes de leveduras (C69, C128, C271, CAT e Saccharomyces cerevisiae). A avaliação envolveu a determinação da assimilação de fonte de carbono e técnica de RAPD (Random Amplified Polymorphic DNA). Os resultados obtidos através dos testes de assimilação de fontes de carbono são importantes para diferenciação e caracterização de leveduras. Sendo, as leveduras C69,C128 e C271 com habilidade para desdobrar xilose como fonte de carbono. A técnica de RAPD obteve dois primers sozinhos não sendo suficientes para a geração de 100 bandas polimórficas para a população, levando-se em conta os resultados do tratamento 2 de 50ng: que pelo polimorfismo gerado pode-se discriminar três grupos principais e distintos: a amostra três sozinha, porém que ocupa uma similaridade com o grupo formado pelo controle e a estirpe 4, e por último o grupo formado pelas amostras 1 e 2, separados do anterior.