Trapping of Spin-0 fields on tube-like topological defects

We have considered the localization of resonant bosonic states described by a scalar field $\Phi$ trapped in tube-like topological defects. The tubes are formed by radial symmetric defects in $(2,1)$ dimensions, constructed with two scalar fields $\phi$ and $\chi$, and embedded in the $(3,1)-$dimensional Minkowski spacetime. The general coupling between the topological defect and the scalar field $\Phi$ is given by the potential $\eta F(\phi,\chi)\Phi^2$. After a convenient decomposition of the field $\Phi$, we find that the amplitudes of the radial modes satisfy Schr\"odinger-like equations whose eigenvalues are the masses of the bosonic resonances. Specifically, we have analyzed two simple couplings: the first one is $F(\phi,\chi)=\chi^2$ for a fourth-order potential and, the second one is a sixth-order interaction characterized by $F(\phi,\chi)=(\phi\chi)^2$% . In both cases the Schr\"odinger-like equations are numerically solved with appropriated boundary conditions. Several resonance peaks for both models are obtained and the numerical analysis showed that the fourth-order potential generates more resonances than the sixth-order one.Comment: 7 pages, 10 figures, matches version published in Physics Letters

The role performed by the teacher’s question in the learning of quadratic function in an exploratory mathem

Communication plays a key role in teaching and learning processes. Questions are a communicational act greatly used by teachers to structure their discourse, establish dynamics, and foster interaction between the different participants in the classroom. In view of these potentialities of questions in the classroom context, we have developed a teaching experiment with the aim of understand the role of the teacher's question in the learning of topics on functions. Considering the nature of this aim, a methodology of qualitative and interpretative nature was used. The data collection was based on the students’ written productions and on the audio and video recordings of a mathematics class of a Grade 10 educational group (in northern Portugal). Data analysis is based on content analysis techniques, crossing collected data and categories emerging from the literature. The study revealed that the teacher’s questions alternated between confirmation, focalization, and inquiry, with inquiry prevailing. Questions aimed at testing the student’s knowledge gave both the teacher and actual student important information. Questions that focused the student’s attention on a particular detail enabled the students to organize their reasoning and structure their answer. Questions that required the students to explain or justify their thoughts were those that proved to most contribute to the development of the student’s reasoning process.info:eu-repo/semantics/publishedVersio

Analysis of equilibrium in industrial variables through Error Correction Models

This research aimed to evaluate the relationship between variables of the temperature adjustment and the percentage of heating in the molding oven of the Polyethylene Terephthalate Resin (PTR) used in the manufacture of the preform of two-liter bottles. It also investigated the direction of causality between these variables in order to determine how an external shock is transmitted to the system. Vector Error Correction (VEC) methodology was used to carry out this study. It was possible to identify the variable to be monitored and estimate the minimum time for the system to reach the stability of the oven temperature

Introdução, coleta e caracterização de recursos genéticos de guandu para produção e grãos e forragem.

O guandu (Cajanus cajan (L.) Millspaugh) é uma das principais leguminosas cultivadas nos trópicos e subtrópicos. Apesar de ocupar o sexto lugar no mundo em área e produção de grãos em relação a outras leguminosas, como o feijão, ervilha e grão-de-bico, presenta, em relação a essas, maior diversidade de uso

Preliminary evaluation of pigeonpea genotypes in the Brazilian Semi-Arid Tropics.

Pigeonpea is a potential crop for the Brazilian semiárid region. However, the available information about it is very limited. Embrapa - Cpatsa, has been carrying out a breeding program to identify suitable genotypes for grain and forage production, using introductions from other regions of the country and from abroad, especially from ICRISAT Asia Center, India

Efeito de diferentes densidades de Telenomus remus no parasitismo de ovos de Spodoptera frugiperda em milho, algodão e soja.

O efeito da liberação de diferentes densidades de Telenomus remus Nixon (Hymenoptera: Scelionidae) por ovo de Spodoptera frugiperda J.E. Smith, 1797 (Lepidoptera: Noctuidae) foi determinado através do estudo do parasitismo após liberações de números variáveis de adultos do parasitoide em relação a um número fixo de ovos da praga. Os ovos foram expostos ao parasitismo no interior de gaiolas com armação de ferro (50 x 50 x 120 cm), recobertas com tecido branco. Foram realizados seis bioensaios, que avaliaram o efeito das densidades de parasitoides em dois estágios fenológicos distintos de três culturas (algodão, milho e soja). Para o milho foi fixado um total de 200 ovos/gaiola e para algodão e soja um total de 300 ovos/gaiola. Os bioensaios foram conduzidos em blocos casualizados com dez tratamentos e dez repetições. Os tratamentos foram 0; 5; 10; 15; 20; 25; 30; 35; 40 e 45 fêmeas de T. remus/gaiola. Após 24 horas da liberação dos parasitoides as posturas foram retiradas das plantas e acondicionadas em câmara climatizada com temperatura de 25±1°C, e umidade relativa de 70±10% e fotofase de 12 h até a avaliação do parasitismo. Os resultados foram submetidos à análise de regressão, relacionando-se o número de fêmeas de T. remus liberadas/gaiola e porcentagem de parasitismo. Em todas as culturas, a resposta do parasitismo em relação ao aumento da densidade de parasitoides pode ser explicada através de uma relação linear crescente entre o número de fêmeas liberadas e o parasitismo de T. remus em ovos de S. frugiperda. Na cultura do milho, os maiores valores de parasitismo foram de 99,8 e 96,8%, nas proporções de 35 e 40 fêmeas/gaiolas nos estágio V4 e V10, respectivamente, que foram estatisticamente iguais. Para a cultura do algodão, os maiores valores de parasitismo foram de 77,8 e 73%, nas proporções de 35 e 40 fêmeas/gaiola no estágio vegetativo e reprodutivo, respectivamente. Na cultura da soja os maiores valores de parasitismo foram de 75,8 e 54,4%, na proporção de 45 fêmeas/gaiola para ambos os estágios vegetativo e reprodutivo. Assim, é possível concluir que as liberações de T. remus nas densidades testadas para as culturas de milho, algodão e soja resultaram em parasitismo superior a 70% nas maiores densidades avaliadas, com exceção do ensaio com soja no estágio reprodutivo.SICONBIOL 2011

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