4,233 research outputs found
Density Dependent Parametrization Models: Formalism and Applications
In this work we derive a formalism to incorporate asymmetry and temperature
effects in the Brown-Rho (BR) scaled lagrangian model in a mean field theory.
The lagrangian density discussed in this work requires less parameters than the
usual models with density dependent couplings. We also present the formalism
with the inclusion of the eight lightest baryons, two lightest leptons, beta
equilibrium and charge neutrality in order to apply the BR scaled model to the
study of neutron stars. The results are again compared with the ones obtained
from another density dependent parametrization model. The role played by the
rearrangement term at T=0 for nuclear or neutron star matter and at finite
temperature is investigated. The BR scaled model is shown to be a good tool in
studies involving density dependent effective masses and in astrophysics
applications.Comment: 23 pages, 10 figure
Costs Associated with Malaria in Pregnancy in the Brazilian Amazon, a Low Endemic Area Where Plasmodium vivax Predominates.
BACKGROUND: Information on costs associated with malaria in pregnancy (MiP) in low transmission areas where Plasmodium vivax predominates is so far missing. This study estimates health system and patient costs of MiP in the Brazilian Amazon. METHODS/PRINCIPAL FINDINGS: Between January 2011 and March 2012 patient costs for the treatment of MiP were collected through an exit survey at a tertiary referral hospital and at a primary health care centre in the Manaus metropolitan area, Amazonas state. Pregnant and post-partum women diagnosed with malaria were interviewed after an outpatient consultation or at discharge after admission. Seventy-three interviews were included in the analysis. Ninety-six percent of episodes were due to P. vivax and 4% to Plasmodium falciparum. In 2010, the total median costs from the patient perspective were estimated at US 216.29 for an outpatient consultation and an admission, respectively. When multiple P. vivax infections during the same pregnancy were considered, patient costs increased up to US 103.51 for a P. vivax malaria episode and US 118.51 and US 17,038.50, of which 92.4% (US$ 15,741.14) due to P. vivax infection. CONCLUSION: Despite being an area of low risk malaria transmission, MiP is responsible for a significant economic burden in Manaus. Especially when multiple infections are considered, costs associated with P. vivax are higher than costs associated with P. falciparum. The information generated may help health policy decisions for the current control and future elimination of malaria in the area
Análise do mercado paraense de mel no período de 1995 a 2010.
Este artigo tem como objetivo analisar a situação do mercado de mel mundial e a nível brasileiro, mais especificamente do Estado do Pará. Para tanto, foram utilizados dados secundários das bases estatísticas do IBGE e FAO. Os resultados mostraram que a China ainda é a principal produtora do mel in natura, possuindo grande influência nos preços no mercado mundial apícola, e o Brasil, em 2010, aparece em 10º lugar no ranking de produção. No aspecto produtivo brasileiro, a região norte participa de uma pequena escala da produção, tendo como principal Estado produtor o Pará. Depois de utilizar a metodologia dos mínimos quadrados como ferramenta econométrica para o cálculo da demanda paraense de mel in natura, obteve-se a proporção da quantidade demandada de mel em relação ao seu preço e à renda per capita paraense
The pasta phase within density dependent hadronic models
In the present paper we investigate the onset of the pasta phase with
different parametrisations of the density dependent hadronic model and compare
the results with one of the usual parametrisation of the non-linear Walecka
model. The influence of the scalar-isovector virtual delta meson is shown. At
zero temperature two different methods are used, one based on coexistent phases
and the other on the Thomas-Fermi approximation. At finite temperature only the
coexistence phases method is used. npe matter with fixed proton fractions and
in beta-equilibrium are studied. We compare our results with restrictions
imposed on the the values of the density and pressure at the inner edge of the
crust, obtained from observations of the Vela pulsar and recent isospin
diffusion data from heavy-ion reactions, and with predictions from spinodal
calculations.Comment: 15 pages, 11 figures and 7 table
Etnocultivo do jambu para abastecimento da cidade de Belém, estado do Pará.
O jambu que faz parte da gastronomia cultural dos paraenses como componente do pato-notucupi e tacacá vem sofrendo grandes transformações com relação a sua utilização. É cultivado por produtores periurbanos em pequenas áreas, em conjunto com outras hortaliças, sobretudo para atender o consumo da cidade de Belém e dos principais núcleos urbanos da mesorregião do Nordeste Paraense. Foi efetuado um levantamento histórico da utilização do jambu, das mudanças com relação e seu emprego na culinária, para indústria de cosméticos e fármacos e nas práticas usadas pelos agricultores periurbanos dos municípios de Ananindeua, Benevides, Santa Izabel do Pará e Santo Antônio de Tauá. A urbanização e a especulação de terras nas áreas próximas de Belém, o surgimento de polos de produção em outros estados e países, o processo de patenteamento para novos produtos no exterior e uso na gastronomia nacional e internacional estão transformando o jambu em uma nova hortaliça dos trópicos
In vitro culture of cupuassu zygotic embryos (Theobroma gradiflorum (Willd.ex spreng.) Scham.).
Dual equivalence in models with higher-order derivatives
We introduce a class of higher-order derivative models in (2,1) space-time
dimensions. The models are described by a vector field, and contain a
Proca-like mass term which prevents gauge invariance. We use the gauge
embedding procedure to generate another class of higher-order derivative
models, gauge-invariant and dual to the former class. We show that the results
are valid in arbitrary (d,1) space-time dimensions when one discards the
Chern-Simons and Chern-Simons-like terms. We also investigate duality at the
quantum level, and we show that it is preserved in the quantum scenario. Other
results include investigations concerning the gauge embedding approach when the
vector field couples with fermionic matter, and when one adds nonlinearity.Comment: RevTex4, 14 pages; new version includes duality at the quantum level,
and new references. To be published in J. Phys.
The importance of the mixed phase in hybrid stars built with the Nambu-Jona-Lasinio model
We investigate the structure of hybrid stars based on two different
constructions: one is based on the Gibbs condition for phase coexistence and
considers the existence of a mixed phase (MP), and the other is based on the
Maxwell construction and no mixed phase is obtained. The hadron phase is
described by the non-linear Walecka model (NLW) and the quark phase by the
Nambu-Jona-Lasinio model (NJL). We conclude that the masses and radii obtained
are model dependent but not significantly different for both constructions.Comment: 8 pages, 7 figures, 3 table
Caracterização dos pomares caseiros dos pequenos agricultores familiares do município de Tomé-Açu Pará.
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