16,551 research outputs found
Effective interactions from q-deformed inspired transformations
From the mass term for the transformed quark fields, we obtain effective
contact interactions of the NJL type. The parameters of the model that maps a
system of non-interacting transformed fields into quarks interacting via NJL
contact terms are discussed
On the q-deformation of the NJL model
Using a q-deformed fermionic algebra we perform explicitly a deformation of
the Nambu-Jona-Lasinio (NJL) Hamiltonian. In the Bogoliubov-Valatin approach we
obtain the deformed version of the functional for the total energy, which is
minimized to obtain the corresponding gap equation. The breaking of chiral
symmetry and its restoration in the limit are then discussed.Comment: 5 eps figure
O tucumã (Astrocaryum vulgare Mart.) principais características e potencialidade agroindustrial.
bitstream/item/40987/1/Boletim-Pesquisa-75-CPATU.pd
Physical approximations for the nonlinear evolution of perturbations in dark energy scenarios
The abundance and distribution of collapsed objects such as galaxy clusters
will become an important tool to investigate the nature of dark energy and dark
matter. Number counts of very massive objects are sensitive not only to the
equation of state of dark energy, which parametrizes the smooth component of
its pressure, but also to the sound speed of dark energy as well, which
determines the amount of pressure in inhomogeneous and collapsed structures.
Since the evolution of these structures must be followed well into the
nonlinear regime, and a fully relativistic framework for this regime does not
exist yet, we compare two approximate schemes: the widely used spherical
collapse model, and the pseudo-Newtonian approach. We show that both
approximation schemes convey identical equations for the density contrast, when
the pressure perturbation of dark energy is parametrized in terms of an
effective sound speed. We also make a comparison of these approximate
approaches to general relativity in the linearized regime, which lends some
support to the approximations.Comment: 15 pages, 2 figure
Residual effect of fertilizing with castor cake on micronutrients of a soil irrigated with domestic wastewater.
Is Thyroid Stunning Clinically Relevant? A Retrospective Analysis Of 208 Patients.
Current guidelines have advised against the performance of (131)I-iodide diagnostic whole body scintigraphy (dxWBS) to minimize the occurrence of stunning, and to guarantee the efficiency of radioiodine therapy (RIT). The aim of the study was to evaluate the impact of stunning on the efficacy of RIT and disease outcome. This retrospective analysis included 208 patients with differentiated thyroid cancer managed according to a same protocol and followed up for 12-159 months (mean 30 ± 69 months). Patients received RIT in doses ranging from 3,700 to 11,100 MBq (100 mCi to 300 mCi). Post-RIT-whole body scintigraphy images were performed 10 days after RIT in all patients. In addition, images were also performed 24-48 hours after therapy in 22 patients. Outcome was classified as no evidence of disease (NED), stable disease (SD) and progressive disease (PD). Thyroid stunning occurred in 40 patients (19.2%), including 26 patients with NED and 14 patients with SD. A multivariate analysis showed no association between disease outcome and the occurrence of stunning (p = 0.3476). The efficacy of RIT and disease outcome do not seem to be related to thyroid stunning.58292-30
La gestion démocratique des écoles: de l´autogouvernement à l’émergence d’une post-démocratie gestionnaire?
O autor assinala três elementos básicos que têm sido historicamente associados à gestão democrática das escolas: eleição, colegialidade, participação na decisão. A combinação ou rejeição de algumas dessas diferentes dimensões, em contextos sociais específicos, pode resultar em várias concepções de gestão
democrática das escolas, desde o autogoverno até à possível ascensão de uma pós-democracia gestionária.The author points out three basic elements that have been
historically associated with the democratic management of schools: election,
collegiality, participation in decision-making. The combination or the rejection
of some of those different dimensions in specific social contexts may result
in various conceptions of democratic management of schools, from selfgovernment
to the possible rise of a managerial post-democracyL’auteur souligne trois éléments de base qui ont été historiquement
associés à la gestion démocratique des écoles: l’élection, la collégialité, la
participation à la décision. La combinaison ou le rejet de certaines de ces
différentes dimensions, dans des contextes sociaux spécifiques, peuvent entraîner des diverses conceptions de la gestion démocratique des écoles, de l’autogouvernement à l’émergence d’une post-démocratie gestionnaire(undefined
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