Combination of Lyapunov Functions and Density Functions for Stability of Rotational Motion

Lyapunov methods and density functions provide dual characterizations of the solutions of a nonlinear dynamic system. This work exploits the idea of combining both techniques, to yield stability results that are valid for almost all the solutions of the system. Based on the combination of Lyapunov and density functions, analysis methods are proposed for the derivation of almost input-to-state stability, and of almost global stability in nonlinear systems. The techniques are illustrated for an inertial attitude observer, where angular velocity readings are corrupted by non-idealities

Influence of aluminum on root growth and of anatomy Stenocalyx dysentericus (DC.) O. Berg

This study aimed to evaluate the effect of aluminum (Al) on root growth and root anatomical structure of Stenocalyx dysentericus seedlings. Newly emerged plants were grown in simple solution composed of 0.1 μM of CaCl2.2H2O and five Al concentrations of 0, 150, 300, 600, and 1200 μM for 37 days in a hydroponic system. Subsequently, the seedlings were evaluated for root growth, relative root elongation, and anatomical studies using bright-field and fluorescence microscopy techniques. The results showed tolerance by S. dysentericus, with more root relative elongation in treatments with 150, 300, and 600 μM of Al. The anatomical studies revealed the presence of Al in root tissue, through the morin reagent, mainly in the 1200 μM treatment, characterizing some internal detoxification mechanism. S. dysentericus demonstrated tolerance in the tests with Al, principally at lower doses. These results may be entirely linked to its wide distribution in the cerrado domain, demonstrating to be a species  adapted to soils with higher Al concentration. S. dysentericus, when subjected to treatment with Al, showed a stimulating effect on root growth; for this species, low concentrations of Al may be essential for better root growth.Keywords: Cerrado, acidic soils, plant toxicity, toleranc

A visual category filter for Google images

We extend the constellation model to include heterogeneous parts which may represent either the appearance or the geometry of a region of the object. The pans and their spatial configuration are learnt simultaneously and automatically, without supervision, from cluttered images. We describe how this model can be employed for ranking the output of an image search engine when searching for object categories. It is shown that visual consistencies in the output images can be identified, and then used to rank the images according to their closeness to the visual object category. Although the proportion of good images may be small, the algorithm is designed to be robust and is capable of learning in either a totally unsupervised manner, or with a very limited amount of supervision. We demonstrate the method on image sets returned by Google's image search for a number of object categories including bottles, camels, cars, horses, tigers and zebras

Manejo do dossel vegetativo e seu efeito nos componentes de produção da videira Merlot.

A poda verde é uma prática cultural utilizada para melhorar as condições do dossel vegetativo dos vinhedos, visando a favorecer a qualidade da uva e do vinho. Nesse sentido, realizou-se este experimento entre as safras de 1993/1994 e 1996/1997, com diferentes modalidades de poda verde, num vinhedo do cv. Merlot conduzido em latada. Houve 12 tratamentos e três repetições, sendo o delineamento experimental em blocos casualizados. Os tratamentos constituíram-se da testemunha e de 11 diferentes modalidades de poda verde, ou seja, desbrota, desponta e desfolha, algumas delas em diferentes épocas do ciclo vegetativo da videira. O componente principal 1, da análise de componentes principais (ACP) feita em cada ano, separadamente, mostra que o tratamento 10 (desbrota + desponta + desfolha realizada no início da floração, eliminando-se as folhas abaixo dos cachos) discriminou-se nos quatro anos, e os tratamentos 7 (desfolha realizada 21 dias antes da colheita, eliminando-se metade das folhas abaixo dos cachos) e 6 (desfolha realizada 21 dias antes da colheita, eliminando-se as folhas abaixo dos cachos), em três deles; a ACP da média dos quatro anos também evidencia essa discriminação entre eles. Constata-se que o tratamento 10 foi um dos que tiveram intensidade de poda verde mais intensa, caracterizando-se por variáveis indicativas de plantas com vigor e produtividade mais baixos que os demais

Single Spin Asymmetry ANA_N in Polarized Proton-Proton Elastic Scattering at s=200\sqrt{s}=200 GeV

We report a high precision measurement of the transverse single spin asymmetry $A_N$ at the center of mass energy $\sqrt{s}=200$ GeV in elastic proton-proton scattering by the STAR experiment at RHIC. The $A_N$ was measured in the four-momentum transfer squared $t$ range $0.003 \leqslant |t| \leqslant 0.035$ \GeVcSq, the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of $A_N$ and its $t$-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the single spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated by the Pomeron amplitude at this $\sqrt{s}$, we conclude that this measurement addresses the question about the presence of a hadronic spin flip due to the Pomeron exchange in polarized proton-proton elastic scattering.Comment: 12 pages, 6 figure