1,178 research outputs found
Aedes (Stegomyia) aegypti L. e a culicideofauna associada em área urbana da região sul, Brasil
Foram mostrados alguns aspectos sobre a ecologia de 11 espĂ©cies de Culicidae que procriam em recipientes, em uma área urbana do Sul do Brasil. Os mais variados tipos de recipientes foram listados como eficientes criadouros para larvas de culicĂdeos. Aedes aegypti apareceu como espĂ©cie recĂ©m-introduzida e limitada somente a duas áreas da cidade. As espĂ©cies predominantes foram: Culex quinquefasciatus, Culex coronator, Aedes aegypti, Aedes fluviatilis e Limatus durhamii.Some aspects of the ecology of eleven species of Culicidae that were found breeding in recipients in an urban area of Southern Brazil are presented. A great variety of recipients were listed as efficient breeding sites. Apparently Aedes aegypti has been recently introduced into the region and was limited to two areas of the city. Culex quinquefasciatus, Cx. coronator, Ae. aegypti, Ae. fluviatilis e Limatus durhamii were the predominant species
Scalar perturbation spectra from warm inflation
We present a numerical integration of the cosmological scalar perturbation
equations in warm inflation. The initial conditions are provided by a
discussion of the thermal fluctuations of an inflaton field and thermal
radiation using a combination of thermal field theory and thermodynamics. The
perturbation equations include the effects of a damping coefficient
and a thermodynamic potential . We give an analytic expression for the
spectral index of scalar fluctuations in terms of a new slow-roll parameter
constructed from . A series of toy models, inspired by spontaneous
symmetry breaking and a known form of the damping coefficient, lead to a
spectrum with on large scales and on small scales.Comment: 12 pages, 5 figures, RevTeX 4, revised with extra figure
Animal-based agriculture, phosphorus management and water quality in Brazil: options for the future
Non-Minimal Warm Inflation and Perturbations on the Warped DGP Brane with Modified Induced Gravity
We construct a warm inflation model with inflaton field non-minimally coupled
to induced gravity on a warped DGP brane. We incorporate possible modification
of the induced gravity on the brane in the spirit of -gravity. We study
cosmological perturbations in this setup. In the case of two field inflation
such as warm inflation, usually entropy perturbations are generated. While it
is expected that in the case of one field inflation these perturbations to be
removed, we show that even in the absence of the radiation field, entropy
perturbations are generated in our setup due to non-minimal coupling and
modification of the induced gravity.Comment: 29 pages, 7 figures, Accepted by Gen. Rel Gravi
Economic analysis of an agrosilvipastoral system for a mountainous area in Zona da Mata Mineira, Brazil
Synergistic warm inflation
We consider an alternative warm inflationary scenario in which scalar
fields coupled to a dissipative matter fluid cooperate to produce power--law
inflation. The scalar fields are driven by an exponential potential and the
bulk dissipative pressure coefficient is linear in the expansion rate. We find
that the entropy of the fluid attains its asymptotic value in a characteristic
time proportional to the square of the number of fields. This scenario remains
nearly isothermal along the inflationary stage. The perturbations in energy
density and entropy are studied in the long--wavelength regime and seen to grow
roughly as the square of the scale factor. They are shown to be compatible with
COBE measurements of the fluctuations in temperature of the CMB.Comment: 13 pages, Revtex 3 To be published in Physical Review
Influence of edapho-climatic factors on the sporulation and colonization of arbuscular mycorrhizal fungi in two Amazonian native fruit species
Arbuscular mycorrhizal fungi (AMF) colonization and spore numbers in the rhizosphere of two fruit species, Paullinia cupana Mart. and Theobroma grandiflorum Schum., growing in a terra firme ecosystem in Central Amazonia were studied from August 1998 to May 2000. Climatic and edaphic factors were also determined to investigate their influence on mycorrhizal variables. Soil pH, Al, Mn and effective cation exchange capacity exhibited seasonal variations during the investigation period. Temporal variations in mycorrhizal colonization levels and spore numbers occurred, indicating seasonality. Moreover, the patterns of mycorrhizal colonization levels and spore numbers for both host species were similar during the studied period. Mycorrhizal variables were related to climatic and edaphic factors, however, the intensity and type of influence of climatic and soil characteristics on AMF development tended to vary with the season and host plant species in Central Amazonia conditions
New Upper Limit of Terrestrial Equivalence Principle Test for Rotating Extended Bodies
Improved terrestrial experiment to test the equivalence principle for
rotating extended bodies is presented, and a new upper limit for the violation
of the equivalence principle is obtained at the level of 1.6, which is limited by the friction of the rotating gyroscope. It
means the spin-gravity interaction between the extended bodies has not been
observed at this level.Comment: 4 page
Chemical composition and acaricidal activity of the leaf and fruit essential oils of Protium heptaphyllum (Aubl.) Marchand (Burseraceae)
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