13,368 research outputs found
Hemispherical power asymmetries in the WMAP 7-year low-resolution temperature and polarization maps
We test the hemispherical power asymmetry of the WMAP 7-year low-resolution
temperature and polarization maps. We consider two natural estimators for such
an asymmetry and exploit our implementation of an optimal angular power
spectrum estimator for all the six CMB spectra. By scanning the whole sky
through a sample of 24 directions, we search for asymmetries in the power
spectra of the two hemispheres, comparing the results with Monte Carlo
simulations drawn from the WMAP 7-year best-fit model. Our analysis extends
previous results to the polarization sector. The level of asymmetry on the ILC
temperature map is found to be compatible with previous results, whereas no
significant asymmetry on the polarized spectra is detected. Moreover, we show
that our results are only weakly affected by the a posteriori choice of the
maximum multipole considered for the analysis. We also forecast the capability
to detect dipole modulation by our methodology at Planck sensitivity.Comment: 7 pages, 9 figures. Accepted for publication in MNRA
The effect of the environment on the Faber Jackson relation
We investigate the effect of the environment on the Faber Jackson (FJ)
relation, using a sample of 384 nearby elliptical galaxies and estimating
objectively their environment on the typical scale of galaxy clusters. We show
that the intrinsic scatter of the FJ is significantly reduced when ellipticals
in high density environments are compared to ellipticals in low density ones.
This result, which holds on a limited range of overdensities, is likely to
provide an important observational link between scaling relations and formation
mechanisms in galaxies.Comment: accepted by Ap
Two-photon decay of heavy quarkonium from heavy-quark spin symmetry
With the recent measurements on and at CLEO,
Babar and Belle, and with the prospect of finding the at the
Tevatron, it seems appropriate to have another look at the two-photon decay of
heavy quarkonium from the standpoint of an effective Lagrangian based on local
operator expansion and heavy-quark spin symmetry. In this talk, I would like to
discuss a recent work on the two-photon decay rates of ground states and
excited states of and using the local operator expansion
approach and heavy-quark spin symmetry and taking into account the
binding-energy. We find that the predicted two-photon width for agrees
well with experiment, but the predicted value for is twice larger
than the CLEO estimation. We point out that the essentially model-independent
ratio of two-photon width to the leptonic width and the
two-photon width could be used to extract the strong coupling
constant .Comment: 9 pages, Talk given at the QCD@Work 2007 International Workshop on
QCD: Theory and Experiment}, Martina Franca, Italy, 16--20 June 200
Análise da situação da ATEPA (Assistência Técnica e Extensão Pesqueira e AquÃcola) no Tocantins: perspectivas e entraves.
O presente estudo tem como objetivo geral analisar a situação dos serviços de ATEPA (Assistência Técnica e Extensão Pesqueira e AquÃcola) no Tocantins e, especificamente, mapear e caracterizar as empresas prestadoras de ATEPA; e caracterizar o perfil dos extensionistas que atuam no setor pesqueiro. O estudo tem caráter exploratório-descritivo utilizando-se de fontes primárias, com o apoio da técnica de entrevista semi-estruturada, além de fontes secundárias.Organizado por: SÃlvio Ricardo Maurano; AQUACIÊNCIA 2012
Seasonal variations in the rate of photosynthetic activity and chemical composition of the seagrass Cymodocea nodosa (Ucr.) Asch.
Temporal changes in biomass, rate of photosynthetic activity and chemical composition of the seagrass Cymodocea nodosa (Ucr.) Asch., under the influence of various environmental factors, were followed in the Faborsa Bay, Northern Adriatic. Throughout the year the estimated average biomass was about 130 g dry wt m-2 with annual production of 80 g C m-2. In general, leaf length, biomass and production showed clear seasonality, with maximum values during the summer period (July-September) and clear minima in winter. Net oxygen production was closely related to biomass, leaf length, chlorophyll concentration, water temperature and incident light intensity. No clear seasonality was observed in the chemical composition (protein, fats, total phosphorus) of C. nodosa. Over the annual cycle, the range of measured variables was 10-16% for protein, 1.7-3.1% for fat, 0.3-0.8% for phosphorus, 1.6-2.6 for nitrogen in leaves, and 5-17% for protein, 0.9-3.2% for fat, 0.1-0.6% for phosphorus and 0.9-2.8 for nitrogen in roots.No disponibl
Scaling of variables and the relation between noncommutative parameters in Noncommutative Quantum Mechanics
We consider Noncommutative Quantum Mechanics with phase space
noncommutativity. In particular, we show that a scaling of variables leaves the
noncommutative algebra invariant, so that only the self-consistent effective
parameters of the model are physically relevant. We also discuss the recently
proposed relation of direct proportionality between the noncommutative
parameters, showing that it has a limited applicability.Comment: Revtex4, 4 pages; version to match the published on
CaracterÃsticas que devem ser avaliadas para seleção ou compra de touros.
A aquisição de touros para o rebanho de cria é um aspecto extremamente importante na tomada de decisão, pois envolve, além do investimento direto nesta compra, o desempenho produtivo e reprodutivo do rebanho e o progresso genético dos animais. Assim, diferentes aspectos devem ser levados em conta quando da compra ou da seleção destes reprodutores no próprio rebanho. Em geral, salientam-se a fertilidade, a libido, funcionalidade, conformação frigorÃfica, caracterÃsticas raciais e os resultados de avaliação genética, especialmente, em termos de DEP - Diferença Esperada na Progênie.bitstream/CPAP/56241/1/CT72.pdfFormato eletrônic
Switching of Magnetic Moments of Nanoparticles by Surface Acoustic Waves
We report evidence of the magnetization reversal in nanoparticles by surface
acoustic waves (SAWs). The experimental system consists of isolated magnetite
nanoparticles dispersed on a piezoelectric substrate. Magnetic relaxation from
a saturated state becomes significantly enhanced in the presence of the SAW at
a constant temperature of the substrate. The dependence of the relaxation on
SAW power and frequency has been investigated. The effect is explained by the
effective ac magnetic field generated by the SAW in the nanoparticles.Comment: Accepted in Europhysics Letter
Núcleos de seleção em bovinos de corte no Pantanal.
Este documento tem o objetivo de levantar a possibilidade, por meio de núcleos de seleção, em futuro próximo, de estruturar um programa de melhoramento de bovinos de corte especÃfico para o Pantanal.bitstream/CPAP/55780/1/DOC88.pdfFormato Eletrônico
Caracterização do sistema de produção de bovinos de corte do Pantanal.
bitstream/CPAP-2009-09/56878/1/FOL139.pd
- …