6 research outputs found
Halo of NGC 4631 and models of cosmic-ray transport
The halo of edge on spiral galaxy of NGC 4631 is studied from 327 MHz to 10700 MHz to delineate the models of cosmic ray transport. Preliminary studies show that the spectral steepening as a function of height above the plane can be understood in terms of the simplest cosmic ray transport models, viz., simple isotropic diffusion in an infinite medium
Cavity QED determination of atomic number statistics in optical lattices
We study the reflection of two counter-propagating modes of the light field
in a ring resonator by ultracold atoms either in the Mott insulator state or in
the superfluid state of an optical lattice. We obtain exact numerical results
for a simple two-well model and carry out statistical calculations appropriate
for the full lattice case. We find that the dynamics of the reflected light
strongly depends on both the lattice spacing and the state of the matter-wave
field. Depending on the lattice spacing, the light field is sensitive to
various density-density correlation functions of the atoms. The light field and
the atoms become strongly entangled if the latter are in a superfluid state, in
which case the photon statistics typically exhibit complicated multimodal
structures.Comment: 10 pages revtex, 13 figure
Screening of plants found in the State of Amazonas, Brazil for activity against Aedes aegypti larvae Triagem de plantas encontradas no Estado do Amazonas para atividade larvicida contra Aedes aegypti
Ethanol, methanol and water extracts representing mostly native plant species found in the Amazon region were prepared, respectively, by maceration, continuous liquid-solid extraction and infusion, followed by evaporation and freeze-drying. The freeze-dried extracts were tested for lethality toward Aedes aegypti larvae at test concentrations of 500 mg / mL. In general, methanol extracts exhibited the greatest larvicidal activity. The following 7 methanol extracts of (the parts of) the indicated plant species were the most active, resulting in 100% mortality in A. aegypti larvae: Tapura amazonica Poepp. (root), Piper aduncum L. (leaf and root), P. tuberculatum Jacq. (leaf, fruit and branch). and Simaba polyphylla (Cavalcante) W.W. Thomas (branch).<br>Extratos aquosos, etanólicos e metanólicos, representando principalmente espécies vegetais nativas encontradas na região Amazônica, foram preparados, respectivamente, por infusão, maceração e extração contínua líquido-sólido, seguida de evaporação e liofilização. Os extratos liofilizados foram testados para atividade contra larvas de Aedes aegypti, na concentração única de 500 mg / mL. Os extratos metanólicos foram, em geral, os que apresentaram maior atividade larvicida. Os seguintes 7 extratos metanólicos das (partes das) espécies vegetais indicadas foram os mais ativos, provocando 100% de mortalidade em larvas de A. aegypti: Tapura amazonica Poepp. (raiz), Piper aduncum L. (folha e raiz), P. tuberculatum Jacq. (folha, fruto e galho) e Simaba polyphylla (Cavalcante) W.W. Thomas (galho)