Avaliação da atividade inseticida de óleos essenciais de plantas da flora nordestina contra a mosca-branca (Bemisia argentifolii).

E conhecido que muitas plantas encerram micromoleculas oriundas do metabolismo secundario, tais como alcaloides, flavonoides, triterpenos, limnnoides, dentre outras, as quais apresentam funcao de protecao contra fitopatogenos e insetos fitofagos. Dos varios exemplos, podemos citar os glicoalcaloides em Solanaceace, os limonoides em Rutaceae, Meliaceae e Simarubaceae. Algumas dessas substancias sao conhecidas por suas propriedade inseticidas, dentre as quais podemos citar: rotenoides obtidos das especies de Lonchocarpus; nicotina de Nicotiana tabacum; precocenos de Ageratrum conyzoides e piretrinas de Crysanthemum cineraefolium (Craveiro e Machado, 1986).bitstream/CNPAT-2010/5858/1/Pa-080.pd

Localization properties of a tight-binding electronic model on the Apollonian network

An investigation on the properties of electronic states of a tight-binding Hamiltonian on the Apollonian network is presented. This structure, which is defined based on the Apollonian packing problem, has been explored both as a complex network, and as a substrate, on the top of which physical models can defined. The Schrodinger equation of the model, which includes only nearest neighbor interactions, is written in a matrix formulation. In the uniform case, the resulting Hamiltonian is proportional to the adjacency matrix of the Apollonian network. The characterization of the electronic eigenstates is based on the properties of the spectrum, which is characterized by a very large degeneracy. The $2\pi /3$ rotation symmetry of the network and large number of equivalent sites are reflected in all eigenstates, which are classified according to their parity. Extended and localized states are identified by evaluating the participation rate. Results for other two non-uniform models on the Apollonian network are also presented. In one case, interaction is considered to be dependent of the node degree, while in the other one, random on-site energies are considered.Comment: 7pages, 7 figure

Cana-do-brejo.

Cana-do-brejo (Costus spicatus Jacq.), também conhecida como cana-de-macaco, cana-do-mansa, caatinga, cana-branca, cana-do-mato, é nativa em quase todo o Brasil, principalmente em áreas de Mata Atlântica e Amazônica, onde é tradicionalmente utilizada como medicinal e ornamental, devido a sua ação diurética e beleza.bitstream/item/51600/1/f-01.pd

Níveis de proteínas totais, albuminas, globulinas e gama-globulinas no soro de matrizes caprinas da raça Moxotó e Saanen criadas no semi-árido nordestino.

São escassos os dados na literatura referentes ao nível de proteínas plasmáticas específicos para as raças nativas e exóticas da espécie caprina. Este estudo teve como objetivo determinar e comparar os níveis de proteínas totais, albuminas, globulinas e gama-globulinas no soro de matrizes caprinas da raça Saanen e Moxotó criadas no Semi-Árido Nordestino, ao longo de 528 horas após o parto. A concentração das proteínas totais foi determinada pelo método do biureto, e para albuminas, utilizou-se o método do verde de bromocresol. A concentração de globulinas foi obtida através da diferença entre proteínas totais e albuminas. Para gamaglobulinas foi utilizado o teste de turbidez de sulfato de zinco. Na análise estatística utilizou-se o software SAS. As médias gerais obtidas para os valores de proteínas totais, albuminas, globulinas e gama-globulinas da espécie caprina, considerando as duas raças, foram de 6,57±1,44; 2,94±0,58 e 3,67±0,84 g/dL e 0,82 ±0,23 de absorvância, respectivamente. Entre raças, foi observada diferença estatística, somente para os valores de gama-globulinas. Constatou-se um leve aumento nos valores de albuminas e discreta diminuição de globulinas da raça Saanen, a partir de 96 horas pós-parto

Gravitation and Duality Symmetry

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 teleparallel gravity or general relativity.Comment: 7 pages, no figures. Version 2: minor presentation changes, references added. Accepted for publication in Int. J. Mod. Phys.

Nanopercolation

We investigate through direct molecular mechanics calculations the geometrical properties of hydrocarbon mantles subjected to percolation disorder. We show that the structures of mantles generated at the critical percolation point have a fractal dimension $d_{f} \approx 2.5$. In addition, the solvent access surface $A_{s}$ and volume $V_{s}$ of these molecules follow power-law behavior, $A_{s} \sim L^{\alpha_A}$ and $V_{s} \sim L^{\alpha_V}$, where $L$ is the system size, and with both critical exponents $\alpha_A$ and $\alpha_V$ being significantly dependent on the radius of the accessing probing molecule, $r_{p}$. Our results from extensive simulations with two distinct microscopic topologies (i.e., square and honeycomb) indicate the consistency of the statistical analysis and confirm the self-similar characteristic of the percolating hydrocarbons. Due to their highly branched topology, some of the potential applications for this new class of disordered molecules include drug delivery, catalysis, and supramolecular structures.Comment: 4 pages, 5 figure