Canonical Transformations in a Higher-Derivative Field Theory

It has been suggested that the chiral symmetry can be implemented only in classical Lagrangians containing higher covariant derivatives of odd order. Contrary to this belief, it is shown that one can construct an exactly soluble two-dimensional higher-derivative fermionic quantum field theory containing only derivatives of even order whose classical Lagrangian exhibits chiral-gauge invariance. The original field solution is expressed in terms of usual Dirac spinors through a canonical transformation, whose generating function allows the determination of the new Hamiltonian. It is emphasized that the original and transformed Hamiltonians are different because the mapping from the old to the new canonical variables depends explicitly on time. The violation of cluster decomposition is discussed and the general Wightman functions satisfying the positive-definiteness condition are obtained.Comment: 12 pages, LaTe

Hilbert Space of Isomorphic Representations of Bosonized Chiral QCD2QCD_2

We analyse the Hilbert space structure of the isomorphic gauge non-invariant and gauge invariant bosonized formulations of chiral $QCD_2$ for the particular case of the Jackiw-Rajaraman parameter $a = 2$. The BRST subsidiary conditions are found not to provide a sufficient criterium for defining physical states in the Hilbert space and additional superselection rules must to be taken into account. We examine the effect of the use of a redundant field algebra in deriving basic properties of the model. We also discuss the constraint structure of the gauge invariant formulation and show that the only primary constraints are of first class.Comment: LaTeX, 19 page

Boas práticas de produção de suínos.

bitstream/item/57842/1/CUsersPiazzonDocumentsCIT-50.pdfColaboradores: Cátia Silene Klein; Doralice Pedroso de Paiva; Franco Martins; Jalusa Deon Kich; Janice Reis Ciacci Zanella; Jerônimo Fávero; Jorge V. Ludke; Luiz Carlos Bordin; Marcelo Miele; Martha M. Higarashi; Nelson Morés; Osmar A. Dalla Costa; Paulo Armando v. de Oliveira; Marisa Teresinha Bertol; Virgínia Santiago Silva

Breeding new sugarcane clones by mixed models under genotype by environmental interaction.

Sugarcane (Saccharumspp.) is one of the most important crops cultivated in the tropics and subtropics and plays a signifi cant economic and environmental role in Brazil. Twenty- four new clones were evaluated in different locations as potential models for recommendation as new varieties. The mixed model methodology, using the harmonic mean of the relative per- formance of genetic values (MHPRVG), facilitated the analysis of genotypic stability and adapt- ability, culminating in the recommendation of clones for each location. MHPRVG ranked clones RB92579, RB867515, SP81-3250, RB947520 and RB931530 as the best fi ve, and, addition- ally, clones with greater genotypic potential were identifi ed for each test in the six localities

On the regular-geometric-figure solution to the N-body problem

The regular-geometric-figure solution to the $N$-body problem is presented in a very simple way. The Newtonian formalism is used without resorting to a more involved rotating coordinate system. Those configurations occur for other kinds of interactions beyond the gravitational ones for some special values of the parameters of the forces. For the harmonic oscillator, in particular, it is shown that the $N$-body problem is reduced to $N$ one-body problems.Comment: To appear in Eur. J. Phys. (5 pages

Selection index and molecular markers in reciprocal recurrent selection in maize.

Reciprocal recurrent selection among full-sib families is one of the outstanding methodologies of maize improvement. since gains are possible in the per se and/or in cross population. Here the selection index proposed by Smith and Hazel was used in the cited methodology; besides. an additiolnal phase involving RAPD markers was introduced to preserve the genetic variability of the selected genotypes and identifv contaminants before their recombination. Multivariate techniques of grouping and discriminant analyses were used for this purpose. to assure the continuance of the improvement program and amplify the genetic distance between the populations Cimmyt and Piranão, which were used for an intervarietal hybrid. The molecullar technique proved useful to identifv contaminants and helpful in the choice of the genotypes to be recombined to maximize heterosis among populations. The technique can be included in recurrent selection programs, mainlv those that target the development of hybrids