Dinâmica de adubos verdes no sistema solo-planta.

bitstream/item/33522/1/documento-127.pd

Adubação foliar em tomateiro estaqueado. (Lycopersicum esculentum, mill). Santa Cruz - Kada.

Experimento realizado em solo latossol vermelho escuro-fase arenosa intergra de Terra roxa estruturada.Resumo

Cana-de-açúcar cultivada em solo adubado com lodo de esgoto: nutrientes, metais pesados e produtividade.

A pesquisa objetivou avaliar o uso de lodo de esgoto (Le) na adubação de soqueira (2o corte) de cana-de-açúcar (Saccharum spp., var. RB72-454). Aplicou-se Le ao solo, localizando-o no fundo de um sulco com 15 cm de profundidade e distando 40 cm da linha de cana. Avaliaram-se os efeitos das doses do Le (0, 15 e 30 t.ha-1) nas produtividades de biomassa e de açúcar, nos teores de nutrientes e de metais pesados do solo e da planta. O Le diminuiu a acidez potencial (H + Al) do solo e forneceu nutrientes para a cana-de-açúcar, principalmente P, S, Ca, Cu e Zn, o que refletiu em aumentos de produtividades de colmos e de açúcar por hectare. O Le causou aumentos de exportações de P, S, Ca, Cu, K, Mg e Ni pela parte aérea da cana-de-açúcar; tais aumentos, por sua vez, foram motivados pelos aumentos dos teores destes elementos no tecido vegetal, e da produtividade em biomassa. Os metais pesados (Cd, Cr, Ni e Pb), contidos no Le, não apresentaram perigo à cadeia trófica à curto prazo

Small changes at single nodes can shift global network dynamics

Understanding the sensitivity of a system's behavior with respect to parameter changes is essential for many applications. This sensitivity may be desired - for instance in the brain, where a large repertoire of different dynamics, particularly different synchronization patterns, is crucial - or may be undesired - for instance in power grids, where disruptions to synchronization may lead to blackouts. In this work, we show that the dynamics of networks of phase oscillators can acquire a very large and complex sensitivity to changes made in either their units' parameters or in their connections - even modifications made to a parameter of a single unit can radically alter the global dynamics of the network in an unpredictable manner. As a consequence, each modification leads to a different path to phase synchronization manifested as large fluctuations along that path. This dynamical malleability occurs over a wide parameter region, around the network's two transitions to phase synchronization. One transition is induced by increasing the coupling strength between the units, and another is induced by increasing the prevalence of long-range connections. Specifically, we study Kuramoto phase oscillators connected under either Watts-Strogatz or distance-dependent topologies to analyze the statistical properties of the fluctuations along the paths to phase synchrony. We argue that this increase in the dynamical malleability is a general phenomenon, as suggested by both previous studies and the theory of phase transitions.Comment: 14 pages, 8 figure

Effects of benzydamine and mouthwashes containing benzydamine on Candida albicans adhesion, biofilm formation, regrowth, and persistence

Objectives To assess the effects of benzydamine and mouthwashes (MoWs) containing benzydamine on different stages of Candida albicans biofilm: adhesion, formation, persistence, and regrowth (if perturbed). Materialsandmethods C.albicansCA1398,carryingthebioluminescenceACT1p-gLUC59fusionproduct,wasemployed. Fungal cells were exposed for 1\u2032, 5\u2032, or 15\u2032 to 4 different benzydamine concentrations (0.075 to 0.6%) to 2 mouthwashes (MoWs) containing benzydamine and to a placebo MoW (without benzydamine). Treated cells were tested for adhesion (90 min) and biofilm formation (24-h assay). Next, 24- and 48-h-old biofilms were exposed to benzydamine and MoWs to assess regrowth and persistence, respectively. The effects of benzydamine, MoWs containing benzydamine, and placebo on different biofilm stages were quantified by bioluminescence assay and by the production of quorum sensing (QS) molecules. Results Benzydamine and MoWs containing benzydamine impaired C. albicans ability to adhere and form biofilm, counter- acted C. albicans persistence and regrowth, and impaired a 48-h-old biofilm. Some of these effects paralleled with alterations in QS molecule secretion. Conclusions Our results show for the first time that benzydamine and MoWs containing benzydamine impair C. albicans capacity to form biofilm and counteract biofilm persistence and regrowth. Clinical relevance Benzydamine and MoWs containing benzydamine capacity to affect C. albicans biofilm provides an interesting tool to prevent and treat oral candidiasis. Likely, restraining C. albicans colonization through daily oral hygiene may counteract colonization and persistence by other critical oral pathogens, such as Streptococcus mutans, whose increased virulence has been linked to the presence of C. albicans biofilm

Atomic Disorder in Fossil Tooth and Bone Mineral: An FTIR Study Using the Grinding Curve Method

Bone and tooth mineral generally undergo diagenetic changes. These changes in the carbonate hydroxyapatite structure and composition can affect the signals embedded in the mineral phase, such as migration behavior, age of the specimen and the reconstruction of past environments. Mineral preservation state can be assessed using infrared spectroscopy which provides information on crystal disorder at the atomic level and mineral composition. Here we present a new approach to evaluate carbonate hydroxyapatite atomic disorder using infrared spectroscopy and the standard KBr sample mounting method. We show that by repeated grinding of the sample and then plotting the infrared splitting factor against the width of the major phosphate absorption peak after each grinding, grinding curves with well defined trend lines can be obtained. The offsets between curves reflect differences in atomic disorder. We show that grinding curve offsets can be used to evaluate the state of preservation of bone, dentine and enamel mineral.Les os et les dents subissent généralement des changements diagénétiques. Ces changements de la structure et de la composition de l’hydroxyapatite carbonatée peuvent affecter les signaux inclus dans la phase minérale, tels que les comportements de migration, l’âge des spécimens ou la reconstitution des environnements passés. L’état de préservation de la phase minérale peut être déterminé par la spectrométrie infrarouge qui fournit des informations sur le désordre structural et sur la composition du minéral. Dans cette étude, nous présentons une nouvelle approche permettant d’évaluer le désordre cristallin en utilisant la spectrométrie infrarouge. Nous montrons ici qu’un broyage répété de l’échantillon et la représentation graphique des valeurs de splitting factor et de la largeur à mi-hauteur de la principale bande d’absorption des phosphates après chaque broyage, peut permettre de définir des courbes de broyage avec des tendances bien définies. Un décalage entre ces courbes reflète des différences de désorganisation à l’échelle atomique

TEORES E ACÚMULO DE NUTRIENTES EM FUNÇÃO DA POPULAÇÃO DE PLANTAS DE CANOLA

To determine spacing and plant density effects on the nutrient contents of canola, an experiment was installed at Experimental Farm of São Manuel of the Faculdade de Ciências Agronômicas do Campus de Botucatu - SP, in Red Yellow Latosol soil, where the main plots were spacing (broadcast, 18cm and 36cm rows) and the subplots were density (600, 900 and 1.200 thousand plants.ha-1), with four replications. Plants were sampled at 30, 45, 60, 90 and 130 days after emergence for evaluation in the dry matter production and the nutrient content. The results showed that spacing and density influenced nutrient contents. The maximum accumulation for macronutrients was at 45 days after planting and maximum for Zn, Fe and B occurred at 45 days and for Cu and Mn at 60 days after emergence.Procurando determinar os efeitos da população de plantas nos teores de nutrientes da canola, conduziu-se um experimento, na Fazenda Experimental de São Manuel, pertencente à Faculdade de Ciências Agronômicas do Campus de Botucatu (SP), em solo classificado como Latossolo Vermelho - Amarelo, com 9 tratamentos, resultantes da combinação de 3 densidades (6.105, 9.105 e 12.105 plantas ha-1) e 3 espaçamentos (a lanço, 18 e 36 cm), com 4 repetições. Utilizou-se o delineamento em blocos casualizados com parcelas subdivididas. Foram colhidas plantas aos 30, 45, 60, 90 e 130 dias após a emergência da cultura, e avaliados os parâmetros produção de matéria seca, teores e conteúdos de nutrientes. Os espaçamentos e as densidades de plantas influenciaram de diferentes modos os teores e conteúdos de nutrientes. O máximo de acúmulo dos macronutrientes e para Zn, Fe , B e deu-se aos 45 dias após emergência das plantas. Para o Cu e o Mn o máximo acúmulo se deu aos 60 dias após emergência da canola

ADUBAÇÃO FOLIAR DO FEIJOEIRO COM NUTRIENTES, VITAMINA B1 E METIONINA

Two experiments were set to determine foliar fertilization effects on bean (Phaseolus vulgaris L.) productivity. The following treatments were used: T1, T2, T3, T4 and T5 (three foliar aplications with formulations 1, 4, 5, 2 and 3 with 3 kg.ha-1 each time), T6 and T7 (three foliar aplications of methionine and vitamin B1, 3 g.ha -1 each time) and T8 (control treatment). T1 consisted of (micro + Mg + S + methionine); T2 (solution with P); T3 (solution with Ca); T4 (micro + Mg + S + vitamin B1), and T5 (micro + Mg + S). Contents of macro and micronutrients of grains, physiological quality of grains and produtivity were evaluated. In a general way, the different treatments, did not influence neither the bean plant produtivity, nor the physiological quality of grain.Procurando determinar os efeitos da adubação foliar sobre a produtividade do feijoeiro (Phaseolus vulgaris L.) foram conduzidos dois experimentos. Os tratamentos, com quatro repetições, com aplicações foliares aos 30, 45 e 60 dias após a emergência das plantas foram: T1 (micro + Mg + S + metionina); T2 (micro + Mg + S + vitamina B1); T3 (micro + Mg + S); T4 (somente P); T5 (somente Ca); T6 (metionina); T7 ( vitamina B1); e T8 (testemunha). Nos tratamentos 1, 2, 3, 4 e 5 foram usadas doses de 3 kg.ha-1, por aplicação e nos tratamentos 6 e 7, doses de 3 g.ha-1. Foram avaliados os teores de macro e micronutrientes dos grãos, a qualidade fisiológica dos grãos e a produtividade. Os diferentes tratamentos realizados não foram eficientes para aumentar produtividade e qualidade fisiológica dos grãos

Simulação do crescimento e desenvolvimento do trigo irrigado utilizando o modelo CERES-Wheat na região de Campinas - SP.

Este trabalho tem como objetivos apresentar de forma sucinta o funcionamento do modelo CERES-Wheat inserido na plataforma DSSAT 3.5, assim como apresentar os resultados obtidos das simulações realizadas com o modelo e os observados em experimento de campo, em especial a sua capacidade de detectar os efeitos da aplicação de N sob a fenologia e produtividade de grãos do trigo sob irrigação.bitstream/CNPTIA/9961/1/circtec2.pdfAcesso em: 28 maio 2008