485 research outputs found

    Geodesign in Pampulha cultural and heritage urban area: Visualization tools to orchestrate urban growth and dynamic transformations

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    This paper discusses the role of visualization in Geodesign methodology consideringits applications in the case study of the region of Pampulha in Belo Horizonte,Minas Gerais, Brazil. In order to consider the opinion of the participants, their effortswere recorded in different steps of the process, at different stages of Geodesign iterations,and different possibilities of visualization were tested. The methodology of Geodesignwas applied in different applications and with different tools. The goal was to determinewhether different techniques and tools used in the process of Geodesign contributed toimproved understanding of data and problem context, and to derive guidelines for improvedGeodesign techniques and tools

    An all-order proof of the equivalence between Gribov's no-pole and Zwanziger's horizon conditions

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    The quantization of non-Abelian gauge theories is known to be plagued by Gribov copies. Typical examples are the copies related to zero modes of the Faddeev-Popov operator, which give rise to singularities in the ghost propagator. In this work we present an exact and compact expression for the ghost propagator as a function of external gauge fields, in SU(N) Yang-Mills theory in the Landau gauge. It is shown, to all orders, that the condition for the ghost propagator not to have a pole, the so-called Gribov's no-pole condition, can be implemented by demanding a nonvanishing expectation value for a functional of the gauge fields that turns out to be Zwanziger's horizon function. The action allowing to implement this condition is the Gribov-Zwanziger action. This establishes in a precise way the equivalence between Gribov's no-pole condition and Zwanziger's horizon condition.Comment: 11 pages, typos corrected, version accepted for publication in Phys. Lett.

    The universal character of Zwanziger's horizon function in Euclidean Yang-Mills theories

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    In light of the recently established BRST invariant formulation of the Gribov-Zwanziger theory, we show that Zwanziger's horizon function displays a universal character. More precisely, the correlation functions of local BRST invariant operators evaluated with the Yang-Mills action supplemented with a BRST invariant version of the Zwanziger's horizon function and quantized in an arbitrary class of covariant, color invariant and renormalizable gauges which reduce to the Landau gauge when all gauge parameters are set to zero, have a unique, gauge parameters independent result, corresponding to that of the Landau gauge when the restriction to the Gribov region Ω\Omega in the latter gauge is imposed. As such, thanks to the BRST invariance, the cut-off at the Gribov region Ω\Omega acquires a gauge independent meaning in the class of the physical correlators.Comment: 14 pages. v2: version accepted by Phys.Lett.

    Implementing the Gribov-Zwanziger framework in N=1 Super Yang-Mills in the Landau gauge

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    The Gribov-Zwanziger framework accounting for the existence of Gribov copies is extended to N=1 Super Yang--Mills theories quantized in the Landau gauge. We show that the restriction of the domain of integration in the Euclidean functional integral to the first Gribov horizon can be implemented in a way to recover non-perturbative features of N=1 Super Yang--Mills theories, namely: the existence of the gluino condensate as well as the vanishing of the vacuum energy.Comment: 19 pages, no figure

    Some remarks on the spectral functions of the Abelian Higgs Model

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    We consider the unitary Abelian Higgs model and investigate its spectral functions at one-loop order. This analysis allows to disentangle what is physical and what is not at the level of the elementary particle propagators, in conjunction with the Nielsen identities. We highlight the role of the tadpole graphs and the gauge choices to get sensible results. We also introduce an Abelian Curci-Ferrari action coupled to a scalar field to model a massive photon which, like the non-Abelian Curci-Ferarri model, is left invariant by a modified non-nilpotent BRST symmetry. We clearly illustrate its non-unitary nature directly from the spectral function viewpoint. This provides a functional analogue of the Ojima observation in the canonical formalism: there are ghost states with nonzero norm in the BRST-invariant states of the Curci-Ferrari model.Comment: 32 pages, 12 figure

    hrGH treatment of glucocorticoid-induced short stature in children

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    O uso crônico de glicocorticóides no tratamento de doenças sistêmicas causa diminuição da velocidade de crescimento (VC), podendo acarretar perda estatural final. As interações entre o eixo adrenal e o eixo GH-sistema IGF têm sido descritas, podendo ocorrer em nível hipotalâmico-hipofisário e na regulação do sistema IGF, inclusive modulando o sinal do IGF-1R. Pode-se dizer que o quadro clínico deve ser considerado como estado de deficiência de Igf-1, absoluta e/ou funcional. As intervenções que possibilitam a normalização funcional do eixo GH-IGF poderiam reduzir a perda estatural destas crianças. Os estudos realizados em pacientes com artrite reumatóide juvenil em tratamento com corticóides mostraram aceleração da VC e diminuição da perda protéica com o uso de GH recombinante humano (hrGH). A aceleração da VC foi também descrita em pacientes sob corticoterapia crônica por causa da doença intestinal inflamatória ou do transplante renal após o uso de hrGH. A dose de hrGH guarda correlação positiva com a aceleração da VC e os resultados reforçam que esta deficiência funcional do eixo GH-IGF pode ser revertida com a administração de hrGH. O efeito do hrGH é restrito ao período de tratamento e depende do esquema de reposição do hrGH, do estado nutricional e das condições da doença de base.The treatment of systemic diseases with glucocorticoids is often associated with decreased height velocity (HV), and can result in shorter final height. Interactions between adrenal and GH-IGF axis have been described and can occur at hypothalamic-pituitary level or at the regulation of IGF system, including the IGF1R signaling. The clinical state of these patients may be considered as an absolute and/or functional IGF-1 deficiency. Interventions aiming to restore the normal function of GH-IGF axis might reduce the glucocorticoids-induced growth suppression in these children. It has been shown that recombinant human GH (hrGH) induces an increase in HV and a decrease in protein loss in patients with juvenile idiopathic arthritis treated with glucocorticoids. Significant increment in HV was also described after hrGH treatment in children under glucocorticoid therapy due to inflammatory bowel disease or renal transplantation. There is a positive correlation between HV and the dose of hrGH. The results support that the IGF-1 deficiency in these children may be counteract by hrGH therapy. The effect of hrGH is observed only during the treatment period and depends on the replacement strategy, nutritional status and disease control
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