80 resultados para basic duality
em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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We show that there exists a duality between the local coordinates and the solutions of the Klein-Gerdon equation in curved spacetime in the same sense as in the Minkowski spacetime. However, the duality in curved spacetime does not have the same generality as in flat spacetime and it holds only if the system satisfies certain constraints. We derive these constraints and the basic equations of duality and discuss the implications in the quantum theory. (C) 2000 Elsevier B.V. B.V. All rights reserved.
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By generalizing the Hodge dual operator to the case of soldered bundles, and working in the context of the teleparallel equivalent of general relativity, an analysis of the duality symmetry in gravitation is performed. Although the basic conclusion is that, at least in the general-case, gravitation is not dual symmetric, there is a particular theory in which this symmetry shows up. It is a self dual (or anti-self dual) teleparallel gravity in which, due to the fact that it does not contribute to the interaction of fermions with gravitation, the purely tensor part of torsion is assumed to vanish. The ensuing fermionic gravitational interaction is found to be chiral. Since duality is intimately related to renormalizability, this theory may eventually be more amenable to renormalization than telepaxallel gravity or general relativity.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The existence of an interpolating master action does not guarantee the same spectrum for the interpolated dual theories. In the specific case of a generalized self-dual (GSD) model defined as the addition of the Maxwell term to the self-dual model in D = 2 + 1, previous master actions have furnished a dual gauge theory which is either nonlocal or contains a ghost mode. Here we show that by reducing the Maxwell term to first order by means of an auxiliary field we are able to define a master action which interpolates between the GSD model and a couple of non-interacting Maxwell-Chern-Simons theories of opposite helicities. The presence of an auxiliary field explains the doubling of fields in the dual gauge theory. A generalized duality transformation is defined and both models can be interpreted as self-dual models. Furthermore, it is shown how to obtain the gauge invariant correlators of the non-interacting MCS theories from the correlators of the self-dual field in the GSD model and vice-versa. The derivation of the non-interacting MCS theories from the GSD model, as presented here, works in the opposite direction of the soldering approach.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The aim of the present study was to conduct a critical literature review about the technique of computer-guided surgery in implantology to highlight the indications, purposes, immediate loading of implants and complications, protocol of fabrication, and functioning of virtual planning software. This literature review was based on OLDMEDLINE and MEDLINE databases from 2002 to 2010 using the key words "computer-guided surgery" and "implant-supported prosthesis." Thirty-four studies regarding this topic were found. According to the literature review, it was concluded that the computer-assisted surgery is an excellent treatment alternative for patients with appropriate bone quantity for implant insertion in complete and partially edentulous arches. The Procera Nobel Guide software (Nobel Biocare) was the most common software used by the authors. In addition, the flapless surgery is advantageous for positioning of implants but with accurate indication. Although the computer-guided surgery may be helpful for virtual planning of cases with severe bone resorption, the conventional surgical technique is more appropriate. The surgical guide is important for insertion of the implants regardless of the surgical technique, and the success of immediate loading after computer-guided surgery depends on the accuracy of clinical and/or laboratorial steps.
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Background: the poor predictability of periodontal regenerative treatment of Class III furcation defects stimulates the study of alternatives to improve its results, such as the use of polypeptide growth factors. The objective of this study was to evaluate, both histologically and histometrically, the effects of topical application of basic fibroblast growth factor (b-FGF) associated with guided tissue regeneration (GTR) in the treatment of Class III defects surgically induced in dogs.Methods: All second and fourth premolars of 5 mongrel dogs were used and randomly assigned to one of three treatment groups: group 1 (control), treated with scaling and root planing, tetracycline hydrochloride (125 mg/ml) conditioning, and GTR with a collagen membrane; group 2, same treatment as group 1 plus 0.5 mg of b-FGF; group 3, same treatment as group 1 plus 1.0 mg of b-FGF. After a 90-day healing period, routine histologic processing and staining with hematoxylin and eosin and Masson trichrome were performed.Results: the descriptive analysis indicated better regenerative results in both groups treated with b-FGF while the histometric data, analyzed by means of analysis of variance (ANOVA), showed greater filling of the defects in group 2 in comparison to the defects in groups 3 and 1, respectively, which was represented by a smaller area of plaque-occupied space (P = 0.004) as well as a greater amount of newly formed cementum (P = 0.002).Conclusions: These results indicate that b-FGF, especially in smaller doses, may enhance the regenerative results in Class III furcation lesions, leading to greater filling of these defects with both mineralized and non-mineralized tissues.
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The karyotypes of five species of Brazilian Pseudophyllinae belonging to four tribes were here studied. The data available in the literature altogether with those obtained with species in here studied allowed us to infer that 2n(♂)=35 is the highest chromosome number found in the family Tettigoniidae and that it is present in species belonging to Pseudophyllinae, Zaprochilinae and in one species of Tettigoniinae. In spite of that all five species exhibit secondary karyotypes arisen surely by a mechanism of chromosomal rearrangement of centric fusion, tandem fusion and centric inversion types from those with 2n(♂)=35 and FN=35, they share some common traits. The X chromosome is submetacentric (FN=36), heteropicnotic during the first prophase, the largest of the set but its size is rather variable among the species and the sex chromosomal mechanism is of the XO( ♂ ), XX( ♀ ) type. The chromosomal rearrangements involved in the karyotype evolution of the Pseudophyllinae and its relationship with those of the family Tettigoniidae are discussed and we propose that the basic and the ancestral karyotype of the Tettigoniidae is formed by 2n(♂)=35, FN=35 and not by 2n(♂)=31, FN= 31, as usually accepted.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)