Ensaio comparativo avançado de arroz de sequeiro em Altamira, Pará - ano agrícola 1998/1999.

bitstream/item/52948/1/PesquisaAnd0160001.pd

Solitary Waves For Some Nonlinear Schrödinger Systems

In this paper we study the existence of radially symmetric positive solutions in Hrad 1 (RN) × Hrad 1 (RN) of the elliptic system:- Δ u + u - (α u2 + β v2) u = 0,- Δ v + ω2 v - (β u2 + γ v2) v = 0,N = 1, 2, 3, where α and γ are positive constants (β will be allowed to be negative). This system has trivial solutions of the form (φ{symbol}, 0) and (0, ψ) where φ{symbol} and ψ are nontrivial solutions of scalar equations. The existence of nontrivial solutions for some values of the parameters α, β, γ, ω has been studied recently by several authors [A. Ambrosetti, E. Colorado, Bound and ground states of coupled nonlinear Schrödinger equations, C. R. Acad. Sci. Paris, Ser. I 342 (2006) 453-458; T.C. Lin, J. Wei, Ground states of N coupled nonlinear Schrödinger equations in Rn, n ≤ 3, Comm. Math. Phys. 255 (2005) 629-653; T.C. Lin, J. Wei, Ground states of N coupled nonlinear Schrödinger equations in Rn, n ≤ 3, Comm. Math. Phys., Erratum, in press; L. Maia, E. Montefusco, B. Pellacci, Positive solutions for a weakly coupled nonlinear Schrödinger system, preprint; B. Sirakov, Least energy solitary waves for a system of nonlinear Schrödinger equations in RN, preprint; J. Yang, Classification of the solitary waves in coupled nonlinear Schrödinger equations, Physica D 108 (1997) 92-112]. For N = 2, 3, perhaps the most general existence result has been proved in [A. Ambrosetti, E. Colorado, Bound and ground states of coupled nonlinear Schrödinger equations, C. R. Acad. Sci. Paris, Ser. I 342 (2006) 453-458] under conditions which are equivalent to ours. Motivated by some numerical computations, we return to this problem and, using our approach, we give a more detailed description of the regions of parameters for which existence can be proved. In particular, based also on numerical evidence, we show that the shape of the region of the parameters for which existence of solution can be proved, changes drastically when we pass from dimensions N = 1, 2 to dimension N = 3. Our approach differs from the ones used before. It relies heavily on the spectral theory for linear elliptic operators. Furthermore, we also consider the case N = 1 which has to be treated more extensively due to some lack of compactness for even functions. This case has not been treated before. © 2007 Elsevier Masson SAS. All rights reserved.251149161Ambrosetti, A., Colorado, E., Bound and ground states of coupled nonlinear Schrödinger equations (2006) C. R. Acad. Sci. Paris, Ser. I, 342, pp. 453-458Bonorino, L., Brietzke, E., Lukaszczyk, J.P., Taschetto, C., Properties of the period function for some hamiltonian systems and homogeneous solutions of a semilinear elliptic equation (2005) J. Differential Equations, 214, pp. 156-175Lin, T.C., Wei, J., Ground states of N coupled nonlinear Schrödinger equations in Rn, n ≤ 3 (2005) Comm. Math. Phys., 255, pp. 629-653Reed, M., Simon, B., (1972) Methods of Modern Mathematical Physics, IV, Analysis of Operators, , Academic Press, New YorkReed, M., Simon, B., (1972) Methods of Modern Mathematical Physics, II, Fourier Analysis, , Academic Press, New YorkYang, J., Classification of the solitary waves in coupled nonlinear Schrödinger equations (1997) Physica D, 108, pp. 92-11

CNA 8170: linhagem de arroz adaptada para o ecossistema terra firme do Estado do Pará.

Cópia de trabalho editado em CD-ROM

Metodologia para conversão de genótipos de milho em endosperma normal para QPM.

xSuplemento. Edição dos resumos do 41º Congresso Nacional de Genética, Caxambu, MG, 1995

Galerias filtrantes para subirrigación, Brasil.

EI arte de recolectar agua de lluvia es milenario (National Academy of Science, 1974). Antiguamente, en la edad de bronce, se ampliaba la escorrentía superficial a través del aplanamiento de la superficie del suelo en las partes altas; ésta, era conducida por canales hacia las partes bajas y utilizada para la agricultura. Desde aquellos tiempos, se observaba también que los caminos tenían una gran capacidad de producir caudales significativos; sin embargo, sólo desde los aíios cincuenta, es que en Australia (Public Works Department of Western Australia, 1956), se empezó a estudiar científicamente Ia utilización de carreteras y caminos como una estrategia para Ia inducción del aprovechamiento de Ia escorrentía superficial. A propósito, millones de acres fueron recortados por carreteras con el objetivo de recoger agua de lluvia para los agricultores de ese país; pero, debido a la necesidad de sus pobladores, esa agua era almacenada en reservorios superficiales y tanques utilizándose en gran parte para consumo humano y animal; y, en raros casos, para cultivos. Actualmente existen experiencias de esta práctica con diferentes configuraciones en varios países como México, Israel y Brasil

Caracterização de sementes de Cucurbita sp.

O objetivo deste trabalho foi avaliar a variabilidade das caracteristicas morfológicas de sementes de abóbora encontrads noBAG de abóbora e moranga da Embrapa Hortaliças a partir de uma amostragem de 40 acessos. A metodologia consistiu em avaliar atraves de pesos e medidas os seguintes parametros: largura, comprimento, espessura, cor, superfície, lustre.CD-ROM. Suplemento. Trabalho apresentado no 51. Congresso Brasileiro de Olericultura, Viçosa, MG

The discriminant power of RNA features for pre-miRNA recognition

Computational discovery of microRNAs (miRNA) is based on pre-determined sets of features from miRNA precursors (pre-miRNA). These feature sets used by current tools for pre-miRNA recognition differ in construction and dimension. Some feature sets are composed of sequence-structure patterns commonly found in pre-miRNAs, while others are a combination of more sophisticated RNA features. Current tools achieve similar predictive performance even though the feature sets used - and their computational cost - differ widely. In this work, we analyze the discriminant power of seven feature sets, which are used in six pre-miRNA prediction tools. The analysis is based on the classification performance achieved with these feature sets for the training algorithms used in these tools. We also evaluate feature discrimination through the F-score and feature importance in the induction of random forests. More diverse feature sets produce classifiers with significantly higher classification performance compared to feature sets composed only of sequence-structure patterns. However, small or non-significant differences were found among the estimated classification performances of classifiers induced using sets with diversification of features, despite the wide differences in their dimension. Based on these results, we applied a feature selection method to reduce the computational cost of computing the feature set, while maintaining discriminant power. We obtained a lower-dimensional feature set, which achieved a sensitivity of 90% and a specificity of 95%. Our feature set achieves a sensitivity and specificity within 0.1% of the maximal values obtained with any feature set while it is 34x faster to compute. Even compared to another feature set, which is the computationally least expensive feature set of those from the literature which perform within 0.1% of the maximal values, it is 34x faster to compute.Comment: Submitted to BMC Bioinformatics in October 25, 2013. The material to reproduce the main results from this paper can be downloaded from http://bioinformatics.rutgers.edu/Static/Software/discriminant.tar.g