Prognostic signatures in breast cancer: correlation does not imply causation

Testing the statistical associations between microarray-based gene expression signatures and patient outcome has become a popular approach to infer biological and clinical significance of laboratory observations. Venet and colleagues recently demonstrated that the majority of randomly generated gene signatures are significantly associated with outcome of breast cancer patients, and that this association stems from the fact that a large proportion of the transcriptome is significantly correlated with proliferation, a strong predictor of outcome in breast cancer patients. These findings demonstrate that a statistical association between a gene signature and disease outcome does not necessarily imply biological significance

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

Efeito da complementação alimentar no pós-parto sobre o desempenho produtivo de cabritos Sem Raça Definida (SRD).

A presente pesquisa foi desenvolvida numa fazenda particular em Pe- trolina- PE, no período de maio a novembro de 1995, e objetivou avaliar o efeito da complementação alimentar de matrizes sem raça definida (SRD) sobre o desem- penho produtivo dos cabritos criados em caatinga não cercada. O delineamento experimental utilizado foi inteiramente casualizado com três tratamentos (T1 : pas- tagem nativa (PN); T2: PN + 25% de NDT e T3 PN + 50% de NDT) e 16 repetições cada. A complementação alimentar foi à base de feno de leucena (Leucaena leu- cocephala (Lam.) de Wit) e raspa de mandioca (Manihot esculenta Crantz.) forne- cida a partir do primeiro dia pós-parto. Para os três tratamentos, os pesos médios observados para os cabritos, do nascimento aos 168 dias de idade, foram estatis- ticamente iguais (P>0,05). A taxa geral de mortalidade de crias aos 112 dias de idade foi de 20,41 %o Não foi possível observar efeito dos tratamentos na taxa de sobrevivência das crias, uma vez que, as causas mais comuns de desaparecimen- to dos animais são roubos e predadores

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

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

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 $H_{n}$, gamma $\Gamma(z)$, polygamma $\psi_{n}(z)$ and zeta Riemann functions $\zeta(z)$.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