16,618 research outputs found
Symmetry Aspects in Nonrelativistic Multi-Scalar Field Models and Application to a Coupled Two-Species Dilute Bose Gas
We discuss unusual aspects of symmetry that can happen due to entropic
effects in the context of multi-scalar field theories at finite temperature. We
present their consequences, in special, for the case of nonrelativistic models
of hard core spheres. We show that for nonrelativistic models phenomena like
inverse symmetry breaking and symmetry non-restoration cannot take place, but a
reentrant phase at high temperatures is shown to be possible for some region of
parameters. We then develop a model of interest in studies of Bose-Einstein
condensation in dilute atomic gases and discuss about its phase transition
patterns. In this application to a Bose-Einstein condensation model, however,
no reentrant phases are found.Comment: 8 pages, 1 eps figure, IOP style. Based on a talk given by R. O.
Ramos at the QFEXT05 workshop, Barcelona, Spain, September 5-9, 2005. One
reference was update
Detection of Leishmania infantum by PCR, serology and cellular immune response in a cohort study of Brazilian dogs
The sensitivity and specificity of PCR, serology (ELISA) and lymphoproliferative response to Leishmania antigen for the detection of Leishmania infantum infection were evaluated in a cohort of 126 dogs exposed to natural infection in Brazil. For PCR, Leishmania DNA from bone-marrow was amplified with both minicircle and ribosomal primers. The infection status and time of infection of each dog were estimated from longitudinal data. The sensitivity of PCR in parasite-positive samples was 98%. However, the overall sensitivity of PCR in post-infection samples, from dogs with confirmed infection, was only 68%. The sensitivity of PCR varied during the course of infection, being highest (78–88%) 0–135 days post-infection and declining to around 50% after 300 days. The sensitivity of PCR also varied between dogs, and was highest in sick dogs. The sensitivity of serology was similar in parasite-positive (84%), PCR-positive (86%) and post-infection (88%) samples. The sensitivity of serology varied during the course of infection, being lowest at the time of infection and high (93–100%) thereafter. Problems in determining the specificity of serology are discussed. The sensitivity and specificity of cellular responsiveness were low. These data suggest that PCR is most useful in detecting active or symptomatic infection, and that serology can be a more sensitive technique for the detection of all infected dogs
Encapsulation of rosmarinic acid into chitosan nanoparticles
Introduction: The use of nanotechnology in medical sciences is a innovation that promises a new age of health. Among the different approaches explored so far, chitosan exhibits favourable and unique biological properties, such as biocompatibility, biodegradability, non-antigenic, non-toxicity and mucoadhesiveness . On the other hand, natural extracts have been incorporated in chitosan films, or macro/microparticles, becoming more effective as antimicrobial or improving the antioxidant protection. The combination of antioxidants and nanoparticles is seen as the key to success in the topical administration of therapeutic antioxidants . Phenolic compound like rosmarinic acid are potent natural antioxidant with a multitude of biological activities like anti-inflammatory, antimutagen, antibacterial and antiviral as well as high potential radical scavenging activity.info:eu-repo/semantics/publishedVersio
Boas Práticas Agropecuárias na ordenha de cabras leiteiras.
bitstream/CNPC-2010/22767/1/ct39.pd
CaracterĂsticas quimico-nutricionais da polpa de Caryocar coriaceum WITTM da regiĂŁo Meio-Norte do Brasil.
A espĂ©cie Caryocar coriaceum (pequi) Ă© tĂpica da regiĂŁo Meio-Norte do Brasil e de outras regiões do Nordeste, onde faz parte da sua culinária e do dia-a-dia nordestino. Objetivou-se neste trabalho avaliar caracterĂsticas quĂmicas e nutricionais da polpa de pequi, de origem dos Estados do PiauĂ e MaranhĂŁo. As seguintes caracterĂsticas foram avaliadas: acidez total titulável (ATT), pH, e percentagens de gordura (GORD), proteĂna bruta (PB), fibra bruta (FB) e carboidratos (CT). Os resultados indicam que a variabilidade Ă© bem maior entre indivĂduos nas diversas populações que entre populações. Em geral, maiores teores de GORD e FB foram obtidos em indivĂduos de populações do MaranhĂŁo, ao passo que em PB os maiores foram observados em indivĂduos provenientes de populações do PiauĂ
Applicability of the Linear delta Expansion for the lambda phi^4 Field Theory at Finite Temperature in the Symmetric and Broken Phases
The thermodynamics of a scalar field with a quartic interaction is studied
within the linear delta expansion (LDE) method. Using the imaginary-time
formalism the free energy is evaluated up to second order in the LDE. The
method generates nonperturbative results that are then used to obtain
thermodynamic quantities like the pressure. The phase transition pattern of the
model is fully studied, from the broken to the symmetry restored phase. The
results are compared with those obtained with other nonperturbative methods and
also with ordinary perturbation theory. The results coming from the two main
optimization procedures used in conjunction with the LDE method, the Principle
of Minimal Sensitivity (PMS) and the Fastest Apparent Convergence (FAC) are
also compared with each other and studied in which cases they are applicable or
not. The optimization procedures are applied directly to the free energy.Comment: 13 pages, 10 eps figures, revtex, replaced with published versio
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