412 research outputs found
Vector meson quasinormal modes in a finite-temperature AdS/QCD model
We study the spectrum of vector mesons in a finite temperature plasma. The
plasma is holographically described by a black hole AdS/QCD model. We compute
the boundary retarded Green's function using AdS/CFT prescriptions. The
corresponding thermal spectral functions show quasiparticle peaks at low
temperatures. Then we calculate the quasinormal modes of vector mesons in the
soft-wall black hole geometry and analyse their temperature and momentum
dependences.Comment: 27 pages, 9 figure
Produção de dois clones de acerola (Malpighia glabra L.) sob diferentes regimes de irrigação.
Com uma area de mais de dois milhoes de hectares plantados com fruteiras , o Brasil ja foi o maior produtor mundial de frutas, estando hoje em segundo lugar. (...) Este trabalho tem como objetivo estudar a frequencia de irrigacao na performance produtiva de dois tipos delecionados de acerola, nas condicoes do litoral cearense. Estas plntas foram obtidas originariamente a partir de sementes coletadas por pesquisadores do CNPAT em 1989, na Fazenda CAJUBA, em Nova Soure, BA (...) Programa de adubacao e dosagens (em g/planta/ano) usadas no experimento de acerola na Estacao Experimental do Vale do Curu.bitstream/CNPAT-2010/5348/1/Ct-018.pd
Tuberculosis in a shopping centre, Portugal, 2004-5
Genotyping enables to confirm or exclude a tuberculosis (TB) cluster. Excluding the link between cases is particularly important in countries with intermediate/high incidence of TB where the emergence of several TB cases in a particular location in space or time (higher than the expected) could be explained by chance alone. During 2004 and 2005, five TB cases occurred in five shops of a Portuguese shopping centre which employed a total of about 1000 workers. After an epidemiological survey, 52 close contacts were identified and screened. Latent tuberculosis infection was diagnosed in 10 contacts (eight family members and two work colleagues of cases). Genotyping of the Mycobacterium tuberculosis isolates revealed no link between the cases. For this reason no screening of all staff of the shopping centre was carried out. However, close contacts (52) and all fellow workers (1000) were kept under surveillance for two years, and no additional cases were diagnosed. The present analysis demonstrates that the exclusion of a chain of ongoing transmission by genotyping for the investigation of a cluster is cost-effective from the perspective of the public health service, because it allows to avoid unnecessary large scale screening operation and instead to direct resources to more effective measures of TB control.info:eu-repo/semantics/publishedVersio
XIPE: the X-ray Imaging Polarimetry Explorer
X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and
temporal variability measurements and to imaging, allows a wealth of physical
phenomena in astrophysics to be studied. X-ray polarimetry investigates the
acceleration process, for example, including those typical of magnetic
reconnection in solar flares, but also emission in the strong magnetic fields
of neutron stars and white dwarfs. It detects scattering in asymmetric
structures such as accretion disks and columns, and in the so-called molecular
torus and ionization cones. In addition, it allows fundamental physics in
regimes of gravity and of magnetic field intensity not accessible to
experiments on the Earth to be probed. Finally, models that describe
fundamental interactions (e.g. quantum gravity and the extension of the
Standard Model) can be tested. We describe in this paper the X-ray Imaging
Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a
small mission with a launch in 2017 but not selected. XIPE is composed of two
out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD)
filled with a He-DME mixture at their focus and two additional GPDs filled with
pressurized Ar-DME facing the sun. The Minimum Detectable Polarization is 14 %
at 1 mCrab in 10E5 s (2-10 keV) and 0.6 % for an X10 class flare. The Half
Energy Width, measured at PANTER X-ray test facility (MPE, Germany) with JET-X
optics is 24 arcsec. XIPE takes advantage of a low-earth equatorial orbit with
Malindi as down-link station and of a Mission Operation Center (MOC) at INPE
(Brazil).Comment: 49 pages, 14 figures, 6 tables. Paper published in Experimental
Astronomy http://link.springer.com/journal/1068
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