Asymptotic stability at infinity for differentiable vector fields of the plane

Let X:R2\Dr->R2 be a differentiable (but not necessarily C1) vector field, where r>0 and Dr={z\in R2:|z|\le r}. If for some e>0 and for all p\in R2\Dr, no eigenvalue of D_p X belongs to (-e,0]\cup {z\in\C:\mathcal{R}(z)\ge 0}, then (a)For all p\in R2\Dr, there is a unique positive semi--trajectory of X starting at p; (b)\mathcal{I}(X), the index of X at infinity, is a well defined number of the extended real line [-\infty,\infty); (c) There exists a constant vector v\in R2 such that if \mathcal{I}(X) is less than zero (resp. greater or equal to zero), then the point at infinity \infty of the Riemann sphere R2\cup\set{\infty} is a repellor (resp. an attractor) of the vector field X+v.Comment: 16 pages, 7 figure

Estudo comparativo entre uma pastagem nativa e o capim pangola (Digitaria decumbens) visando a produção de leite.

Produção de leite através de um criatorio em regime de campo na zona da mata de Pernambuco.Resumo

Numerical-experimental analysis of the permeability-porosity relationship in triply periodic minimal surfaces scaffolds

Bone Tissue Engineering has been focusing on improving the current methods for bone repair, being the use of scaffolds presented as an upgrade to traditional surgery techniques. Scaffolds are artificially porous matrices, meant to promote cell seeding and proliferation, being these properties influenced by the permeability of the structure. This work employed experimental pressure drop tests and Computational Fluid Dynamics models to assess permeability (and fluid streamlines) within different triply periodic minimal surfaces scaffold geometries (Schwarz D, Gyroid and Schwarz P). The pressure outputs from the computational analysis presented a good correlation with the experimental results, with R2 equal to 0.903; they have also shown that a lower porosity may not mean a lower permeability if the geometry is altered, such as the difference between 60% porous Gyroid scaffolds (8.1*10-9 mm2) and 70% porous Schwarz D scaffolds (7.1*10-9 mm2). Fluid streamlines revealed how the Gyroid geometries are the most appropriate design for most bone tissue engineering applications, due to their consistent fluid permeation, followed by Schwarz D. The Schwarz P geometries have shown flat streamlines and significant variation of the permeability with the porosity (an increase of 10% in their porosity lead to an increase in the permeability from 5.1*10-9 mm2 to 11.7*10-9 mm2), which would imply a poor environment for cell seeding and proliferation.info:eu-repo/semantics/publishedVersio

Digestibilidade da matéria seca do feno de alfafa e farelo de mamona desintoxicada pela técnica do "saco de nylon".

Comparação da digestibilidade de matéria seca do feno de alfafa e do farelo de mamona desintoxicada, pela técnica do saco de nylon, utilizando-se como repetições 2 bovinos fistulados adultos da raça holandesa

Chemical ecology of echinoderms: Impact of environment and diet in metabolomic profile

The phylum Echinodermata constitutes a successful and widespread group comprising Asteroidea, Ophiuroidea, Echinoidea, Holothuroidea and Crinodeia. Nowadays, marine organisms are being given a lot of attention in drug discovery pipelines. In these studies, sponges and nudibranchs are frequently addressed, however an increasing number of works focus their attention in echinoderms. Given the fact that many of the bioactive molecules found in echinoderms are diet-derived, different feeding behavior and surrounding environment plays a critical role in the chemical composition of echinoderms. In this work, the most relevant chemical classes of small molecules present in echinoderms, such as fatty acids, carotenoids and sterols will be addressed. When data is available, the influence of the environment on the chemical profile of these organisms will be discussed.(undefined

Estudos sobre nível proteíco e uréia na alimentação de vacas mestiças em produção.

Estudos sobre nivel proteina e ureia na alimentacao de vacas mesticas em producao

Evaluación de las dimensiones de la personalidad depresiva en el PID-5 y de la sintomatología depresiva en una muestra comunitaria

The alternative model for the classification of personality disorders presented in the DSM-5 is based on the hypothesis of continuity between normal personality and personality disorders. The main objective of this study is to analyze the relationship between depressive symptomatology and the domains and facets of the PID-5, especially the Depressivity facet. A convenience sample of the general population (N = 453) was used. Participants responded to the PID-5 and the CES-D. In a multiple regression model including all the PID-5 facets, only Depressivity and Anhedonia had a significant individual effect on predicting the CES-D score. Correlation analysis suggested that Depressivity and Anhedonia could be considered as defining the depressive traits of personality disorders and supported the continuity between these disorders and depressive symptomatology. A Taxometric Analysis with the Depressivity facet and CES-D score as indicators supported the dimensional nature of depressivity in a broad sense (depressive traits/ depressive symptomatology).info:eu-repo/semantics/publishedVersio

On the width of the last scattering surface

We discuss the physical effects of some accelerated world models on the width of the last scattering surface (LSS) of the cosmic microwave background radiation (CMBR). The models considered in our analysis are X-matter (XCDM) and a Chaplygin type gas. The redshift of the LSS does not depend on the kind of dark energy (if XCDM of Chaplygin). Further, for a Chaplygin gas, the width of the LSS is also only weakly dependent on the kind of scenario (if we have dark energy plus cold dark matter or the unified picture).Comment: 10 pages, 1 figure, 2 tables, accepted to IJMP