Recent Advances in Chromospheric and Coronal Polarization Diagnostics

I review some recent advances in methods to diagnose polarized radiation with which we may hope to explore the magnetism of the solar chromosphere and corona. These methods are based on the remarkable signatures that the radiatively induced quantum coherences produce in the emergent spectral line polarization and on the joint action of the Hanle and Zeeman effects. Some applications to spicules, prominences, active region filaments, emerging flux regions and the quiet chromosphere are discussed.Comment: Review paper to appear in "Magnetic Coupling between the Interior and the Atmosphere of the Sun", eds. S. S. Hasan and R. J. Rutten, Astrophysics and Space Science Proceedings, Springer-Verlag, 200

THE WORLD MARKET FOR SOYBEANS: PRICE TRANSMISSION INTO BRAZIL AND EFFECTS FROM THE TIMING OF CROP AND TRADE

This paper investigates the price transmission in the world market for soybeans using time series econometrics models. The theoretical model developed by Mundlack and Larson (1992) is based on the Law of the One Price, which assumes price equalization across all local markets in the long run and allows for deviations in the short run. The international market was characterized by three relevant soybean prices: Rotterdam Port, Argentina and the United States. The paper estimates the elasticity of transmission of these prices into soybean prices in Brazil. There were carried causality and cointegration tests in order to identify whether there is significant long-term relationship among these variables. There was also calculated the impulse-response function and forecast error variance decomposition to analyze the transmission of variations in the international prices over Brazilian prices. An exogeneity test was also carried out so as to check whether the variables respond to short term deviations from equilibrium values. Results validated the Law of the One Price in the long run. In line with many studies, this paper showed that Brazil and Argentina can be seen as price takers as long as the speed of their adjustment to shocks is faster than in the United States, the latter being a price maker. An interesting conclusion was reached when the pattern of the impulse response functions was compared to the timing of crop and trade in Brazil, Argentina and the United States. These seasonal differences may help explaining the pattern of the response of Brazilian prices to shocks in the international market, especially that the response from shocks in the United States is opposite to the response from shocks in Argentina because harvest in the two hemispheres occurs in different periods. In addition, the one-month lag between Brazilian and Argentine harvests may contribute to explain a turning point in the impulse-response function that occurs one month after the shock.

Geometrical foundations of fractional supersymmetry

A deformed $q$-calculus is developed on the basis of an algebraic structure involving graded brackets. A number operator and left and right shift operators are constructed for this algebra, and the whole structure is related to the algebra of a $q$-deformed boson. The limit of this algebra when $q$ is a $n$-th root of unity is also studied in detail. By means of a chain rule expansion, the left and right derivatives are identified with the charge $Q$ and covariant derivative $D$ encountered in ordinary/fractional supersymmetry and this leads to new results for these operators. A generalized Berezin integral and fractional superspace measure arise as a natural part of our formalism. When $q$ is a root of unity the algebra is found to have a non-trivial Hopf structure, extending that associated with the anyonic line. One-dimensional ordinary/fractional superspace is identified with the braided line when $q$ is a root of unity, so that one-dimensional ordinary/fractional supersymmetry can be viewed as invariance under translation along this line. In our construction of fractional supersymmetry the $q$-deformed bosons play a role exactly analogous to that of the fermions in the familiar supersymmetric case.Comment: 42 pages, LaTeX. To appear in Int. J. Mod. Phys.

A dual-mode generalized likelihood ratio approach to self-reorganizing digital flight control system design

The research is reported on the problems of failure detection and reliable system design for digital aircraft control systems. Failure modes, cross detection probability, wrong time detection, application of performance tools, and the GLR computer package are discussed

Scattering polarization in the CaII Infrared Triplet with Velocity Gradients

Magnetic field topology, thermal structure and plasma motions are the three main factors affecting the polarization signals used to understand our star. In this theoretical investigation, we focus on the effect that gradients in the macroscopic vertical velocity field have on the non-magnetic scattering polarization signals, establishing the basis for general cases. We demonstrate that the solar plasma velocity gradients have a significant effect on the linear polarization produced by scattering in chromospheric spectral lines. In particular, we show the impact of velocity gradients on the anisotropy of the radiation field and on the ensuing fractional alignment of the CaII levels, and how they can lead to an enhancement of the zero-field linear polarization signals. This investigation remarks the importance of knowing the dynamical state of the solar atmosphere in order to correctly interpret spectropolarimetric measurements, which is important, among other things, for establishing a suitable zero field reference case to infer magnetic fields via the Hanle effect.Comment: 14 pages, 10 figures, 3 appendixes, accepted for publication in Ap

Spin-half bosonic classification

In this paper, we define a new spinor classification that encompasses the recently proposed spin-half bosons with mass dimension three-half. As it will be shown, these particles, which are governed by a first-order equation and consequently provide a local theory, belong to a specific subclass of class-2 spinors within the bosonic classification, playing a similar role to Dirac spinors within the Lounesto classification. Such bosonic classification is shown to be closely connected with the usual fermionic Lounesto classification, and thus, evincing a symmetry between Dirac fermions and spin-half bosons.Comment: 5 page

Telenomus remus Nixon egg parasitization of three species of Spodoptera under different temperatures.

Telenomus remus Nixon is a promising biocontrol agent as an egg parasitoid of Spodoptera spp., but the lack of information on the host?parasitoid interactions in this system precludes its applied use in agriculture. Therefore, we studied the parasitism capacity of T. remus on eggs of Spodoptera cosmioides (Walker), Spodoptera eridania (Cramer), and Spodoptera frugiperda (Smith) in a range of temperatures (19, 22, 25, 28, 31, and 34 ± 1°C) under controlled conditions (70 ± 10% RH and 12 h photophase). Egg masses of Spodoptera spp. were offered to a single-mated T. remus female on a daily basis. More than 80% lifetime parasitism on eggs of S. cosmioides, S. frugiperda, and S. eridania was reached from 1 to 5, 1 to 7, and 1 to 9 days, respectively, at temperatures from 19 to 34°C. More than 80% parasitization was obtained at extreme temperatures for all hosts studied. Lifetime parasitization of S. frugiperda, S. cosmioides, and S. eridania was affected by temperature, with the lowest values for S. frugiperda (34°C) and S. cosmioides (19 and 34°C). Parasitization of S. eridania eggs was reduced around 18% at 28 and 31°C, but dropped more severely at 34°C. Parasitoid longevity was reduced as temperature increased. Thus, our data indicated that T. remus might be suitable as a biocontrol agent against S. eridania, S. cosmioides, and S. frugiperda in geographical areas that fit the temperature range studied here, even though T. remus parasitism was reduced at 34°C