Programming languages in economics: a comparison among Fortran77, C++, and Java

The main objective of this paper was to compare the computer programming languages Fortran77, C++, and Java under four aspects: runtime efficiency, readability, ease of learning, and reliability. For this comparison, we revised the specialized literature on programming languages and used pieces of codes of these three programming languages. The purpose of this comparison was to provide some objective information for economists interested in learning one or more of these languages.Programming language, Runtime efficiency, Readability, Reliability, Teaching/Communication/Extension/Profession,

Fermionic vacuum polarization induced by a non-Abelian vortex

In this paper, we analyze the fermionic condensate (FC) and the vacuum expectation value (VEV) of the energy-momentum tensor associated with an isospin-$1/2$ charged massive fermionic field induced by the presence of a $SU(2)$ vortex, taking into account the effect of the conical geometry produced by this object. We consider the vortex as an idealized topological defect, i.e., very thin, straight and carrying a magnetic flux running along its core. Besides the direct coupling of the fermionic field with the iso-vector gauge field, we also admit the coupling with the scalar sector of the non-Abelian vortex system, expressed as a vector in the three-dimensional isospace. Due to this interaction, the FC is expressed as the sum of two contributions associated with the two different effective masses for the $\pm 1/2$ fermionic components of the isospin operator, $\tau^3/2$. The VEV of the energy-tensor also presents a similar structure. The vacuum energy density is equal to the radial and axial stresses. As to the azimuthal one, it is expressed in terms of the radial derivative of energy-density. Regarding to the magnetic flux, both, the FC and the VEV of the energy-momentum tensor, can be positive or negative. Another interesting consequence of the interaction with the bosonic sector, the FC and VEV of the energy-momentum tensor, present different intensity for different values of the ratio between the scalar coupling constant and the mass of the fermionic field. This is a new feature that the system presents.Comment: 24 pages, 4 figures. Version accepted for publication in IJMP

Critérios para determinação da idade ideal de liberação de Cotesia flavipes.

Publicado também no Cadernos de Agroecologia, v. 7, n.2, 2012

Diversidade genética da população do fungo Lasiodiplodia theobromae associada espécies e híbridos de citros.

Recentemente constatou-se que o fungo Lasiodiplodia theobromae é o agente causal da doença denominada Descamamento Eruptivo dos Citros (DEC), até então considerada como uma disfunção cítrica de causa desconhecida. A constatação do fungo ocorreu em observações de sintomas típicos em 90 plantas de diferentes espécies cítricas e híbridos