3,364 research outputs found
Importância da apicultura no Pantanal Sul-Mato-Grossense.
Panorama da Apicultura brasileira e mundial; Apicultura no Pantanal Sul-Mato-Grossense; Caracterização; Potencial econômico; Produção extrativista; Flora apícola; Instalação do apiário; Manejo do apiário.bitstream/item/81133/1/DOC56.pd
Quantum gases on a torus
This manuscript is aimed at studying the thermodynamic properties of quantum
gases confined to a torus. To do that, we consider \textit{noninteracting}
gases within the grand canonical ensemble formalism. In this context, fermoins
and bosons are taken into account and the calculations are properly provided in
both analytical and numerical manners. In particular, the system turns out to
be sensitive to the topological parameter under consideration: the winding
number. Furthermore, we also derive a model in order to take into account
\textit{interacting} quantum gases. To corroborate our results, we implement
such a method for two different scenarios: a ring and a torus.Comment: 22 pages, 7 figure
Gravitational waves effects in a Lorentz-violating scenario
This paper focuses on how the production and polarization of gravitational
waves are affected by spontaneous Lorentz symmetry breaking, which is driven by
a self-interacting vector field. Specifically, we examine the impact of a
smooth quadratic potential and a non-minimal coupling, discussing the
constraints and causality features of the linearized Einstein equation. To
analyze the polarization states of a plane wave, we consider a fixed vacuum
expectation value (VEV) of the vector field. Remarkably, we verify that a
space-like background vector field modifies the polarization plane and
introduces a longitudinal degree of freedom. In order to investigate the
Lorentz violation effect on the quadrupole formula, we use the modified Green
function. Finally, we show that the space-like component of the background
field leads to a third-order time derivative of the quadrupole moment, and the
bounds for the Lorentz-breaking coefficients are estimated as well.Comment: 19 pages and 1 figur
Thermal analysis of photon-like particles in rainbow gravity
This work is devoted to study the thermodynamic behavior of photon--like
particles within the \textit{rainbow} gravity formalism. To to do this, we
chose two particular ansatzs to accomplish our calculations. First, we consider
a dispersion relation which avoids UV divergences, getting a positive effective
cosmological constant. We provide \textit{numerical} analysis for the
thermodynamic functions of the system and bounds are estimated. Furthermore, a
phase transition is also expected for this model. Second, we consider a
dispersion relation employed in the context of \textit{Gamma Ray Bursts}.
Remarkably, for this latter case, the thermodynamic properties are calculated
in an \textit{analytical} manner and they turn out to depend on the harmonic
series , gamma , polygamma and zeta Riemann
functions .Comment: 22 pages, 7 figure
Thermodynamical properties of an ideal gas in a traversable wormhole
In this work, we analyze the thermodynamic properties of non--interacting
particles under influence of the gravitational field of a traversable wormhole.
In particular, we investigate how the thermodynamic quantities are affected by
the Ellis wormhole geometry, considering three different regions to our study:
asymptotically far, close to the throat, and at the throat. The thermodynamic
quantities turn out to depend strongly on parameter that controls the wormhole
throat radius. By varying it, there exist an expressive modification in the
thermodynamic state quantities, exhibiting both usual matter and dark
energy--like behaviors. Finally, the interactions are regarded to the energy
density and it seems to indicate that it "cures" the dark energy--like
features.Comment: 29 pages and 18 figure
Maspin expression in normal skin and usual cutaneous carcinomas
Maspin is a serine protease inhibitor whose gene is located on 3q27. Several lines of evidence point towards its putative role as tumor suppressor gene and angiogenesis inhibitor; however, there are compelling data showing that maspin is also expressed in the nuclear compartment and might be associated with the differentiation of specific cell lineages. No systematic study of maspin expression in normal skin and usual skin carcinomas have been published so far. We semiquantitatively analyzed the distribution and immunoreactivity pattern of maspin in 14 squamous cell carcinomas (SCCs) and 16 basal cell carcinomas (BCCs) and in the adjacent normal epidermis of all cases. We also examined the correlation of maspin expression with histological type, grade, vascular invasion, perineural infiltration, and mitotic counting. Cytoplasmic expression of maspin was observed in suprabasal, prickle, and granular cell layers of normal epidermis; cells of the germinative hair matrix, Henle's and Huxley's layers, and cuticle of hair follicles; mature sebaceous cells and sweat gland's secretory cells. Nuclear expression was detected in some basal/myoepithelial cells of the sweat glands and scattered mature sebaceous cells. All SCCs but one grade IV SCC showed maspin expression, and it was correlated with the differentiation of these neoplasms. BCCs presented variable maspin expression, while metatypical carcinomas showed moderate to intense maspin expression, nodular BCCs variable contents of maspin and displayed a peculiar distribution, confined to the center of the neoplastic nodules. Two BCCs and one SCC showed maspin nuclear expression. No correlation with other clinical pathological features was observed. Our findings do not support the role of maspin as a tumor suppressor gene and suggest that this serpin is probably associated with specific lines of differentiation
Solos ferruginosos em áreas de canga, sinclinal do gandarela, quadrilátero ferrífero (MG).
O presente trabalho visa contribuir na caracterização de solos relacionados a áreas de canga (ferricrete, ironstone) no Quadrilátero Ferrífero (Minas Gerais, Brasil), para melhor entendimento sobre seus processos de gênese e da dinâmica ambiental desses ecossistemas. A Sinclinal do Gandarela abriga as maiores extensões de canga e ecossistemas relacionados preservados em Minas Gerais, e constitui importante local de recarga dos mananciais que abastecem a Região Metropolitana de Belo Horizonte. Foram descritos, coletados e analisados 6 perfis de solo, sob diferentes fitofisionomias, ocorrendo numa sequência de topos da serra do Gandarela, sobre a mesma litologia (itabiritos da Fm. Cauê - Gr. Itabira). Em laboratório foi separada a fração terra fina (< 2 mm) e quantificados a composição granulométrica, pH em água, complexo sortivo, carbono orgânico, e óxidos de ferro, alumínio e silício pelo ataque sulfúrico. Todos os solos estudados são argilosos, de cores vermelhas, com teores muito elevados de óxidos de ferro indicados pelo ataque sulfúrico, distróficos ou álicos, com altos teores de carbono orgânico, e ocorrência expressiva de concreções ferruginosas na fração grosseira, em geral em proporção superior a 50% em volume. A matéria orgânica constitui elemento chave na manutenção e ciclagem de nutrientes nos ecossistemas relacionados aos solos estudados. Todos os solos estudados são classificados como Oxisols pela Soil Taxonomy, mas de acordo com o Sistema Brasileiro de Classificação de Solos, alguns enquadram-se como Latossolos e outros como Plintossolos. O enquadramento taxonômico segundo critérios atuais do SiBCS restringe sua utilização como estraficador ambiental na realidade estudada
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