Schwinger-Dyson equations and the quark-antiquark static potential

In lattice QCD, a confining potential for a static quark-antiquark pair can be computed with the Wilson loop technique. This potential, dominated by a linear potential at moderate distances, is consistent with the confinement with a flux tube, an extended and scalar system also directly observable in lattice QCD. Quantized flux tubes have also been observed in another class of confinement, the magnetic confinement in type II superconductors. On the other hand the solution of Schwinger Dyson Equations, say with the Landau gauge fixing and the truncation of the series of Feynman diagrams, already at the rainbow level for the self energy and at the ladder level for the Bethe Salpeter equation, provides a signal of a possible inverse quartic potential in momentum space derived from one gluon and one ghost exchange, consistent with confinement. Here we address the successes, difficulties and open problems of the matching of these two different perspectives of confinement, the Schwinger-Dyson perspective versus the flux tube perspective.Comment: 12 pages, 18 figures; talk presented at QCD-TNT, Trento, 7-11 sep 200

Essential oil of Elyonurus muticus (Sprengel) O. Kuntze (Gramineae).

Twelve compounds were identified by GC.MS in the essential oil of Elyonurus muticus leaves, native in the Brazilian Pantanal. Spathulenol (18.6%), B-caryophyllene (17.9%) and camphene (11.5%) were the major components found in the oil

Water network design using a multiobjective real options framework

This is the final version of the article. Available from the publisher via the DOI in this record.Water distribution networks (WDNs) are an essential element of urban infrastructure. To achieve a good level of performance, the traditional design of WDNs based on expected future conditions should be replaced by a flexible design, using real options (ROs), that accounts for uncertainty by taking a broader view of possible future options. This work proposes a multiobjective ROs framework that sets out to reduce costs, minimize hydraulic pressure deficiency, and a third objective for minimizing carbon emissions. A multiobjective simulated annealing algorithm is used to identify the Pareto-optimal solutions, thus enabling a tradeoff analysis between solutions. These trade-offs show that a low pressure deficit solution is achieved by increasing investment at a much faster rate after a certain pressure deficit threshold (60 m). Also, the pressure deficits can only be reduced by increasing carbon emissions. Finally, this work also emphasizes the importance of including carbon emissions as a specific objective by comparing the results of the proposed model and another one that did not cover the environmental objective. The results show that it is possible to reduce CO2 for the same level of capital expenditure or the same level of network pressure deficits if carbon emissions are minimized in the optimization process.This study had the support of Fundac¸ao para a Ci ˜ encia e ˆ Tecnologia (FCT), through the Strategic Project UID/MAR/ 04292/2013 granted to MARE

Clavibacter michiganensis subsp. insidiosus: bactéria quarentenária com risco para as culturas forrageiras no Brasil.

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Produção sazonal de óleo essencial em uma população natural de Piper aduncum L. em Adrianópolis - PR.

O objetivo desta pesquisa foi verificar a produção sazonal de óleo essencial em uma população natural de Piper aduncum L. no município de Adrianópolis - PR

Curtobacterium flaccumfaciens pv. flaccumfaciens Murcha bacteriana do feijoeiro e da soja: alto risco de disseminação no Brasil.

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Repetibilidade para caracteres de frutos em plantas de camucamuzeiro.

O objetivo deste trabalho foi estimar os coeficientes de repetibilidade para caracteres de frutos em plantas de camucamuzeiro. Foram avaliadas 27 plantas pertencentes a um Ensaio clonal da Embrapa Amazônia Oriental, em Belém, PA. De cada planta foram colhidos cinco frutos para a mensuração de sete caracteres. As estimativas de repetibilidade foram obtidas pelos métodos estatísticos da análise de variância, componentes principais e análise estrutural. Em todos os caracteres as estimativas de repetibilidade apresentaram valores muito semelhantes nos três métodos. As estimativas dos coeficientes de repetibilidade e as previsibilidades foram relativamente altas (r ? 0,50 e R2 ? 82,80%) para o caráter espessura da casca, demonstrando regularidade das plantas nas várias medições (frutos), em todos os métodos. Para esse caráter, o número mínimo de frutos necessários para a avaliação do real valor dos genótipos foi de 20 frutos com confiabilidade de 95%, tornando-os factíveis no uso de inferências genéticas para as condições do estudo. Os demais caracteres exibiram repetibilidades e coeficientes de determinação de baixas magnitudes, indicando necessidade de maior controle ambiental para suas mensurações