Galactic Nonlinear Dynamic Model

We develop a model for spiral galaxies based on a nonlinear realization of the Newtonian dynamics starting from the momentum and mass conservations in the phase space. The radial solution exhibits a rotation curve in qualitative accordance with the observational data.Comment: 6 pages, 1 figure. Talk given in the 7th Alexander Friedmann International Seminar, June 29 to July 5, 2008, Joao Pessoa, PB, Brazi

Seleção genômica ampla.

Introdução; Genética de associação; Seleção genômica ampla; Definição; Tipos de população; Validação cruzada; Fatores que afetam a seleção genômica ampla; Métodos estatísticos na seleção genômica ampla; RR-BLUP; Bayes A; Bayes B; LASSO Bayesiano; Estimação dos efeitos genéticos genômicos na população de seleção; Exemplos; Aplicação da seleção genômica ampla em diferentes organismos; Aplicações da seleção genômica no melhoramento animal; Aplicações da seleção genômica no melhoramento de plantas; Perspectivas; Referências

Mineralogia da argila de latossolos estimada por alocação a partir do teor total de óxidos do ataque sulfúrico.

E apresentado um metodo de alocacao que estima a composicao mineralogica da argila de latossolos a partir dos teores de oxidos pelos metodos do ataque sulfurico e da difracao de raios X. Esse metodo e adequado para latossolos cuja fracao argila e constituida predominantemente decaulinita, gibbsita, hematita e goethita

Relation between phosphorus adsorption and clay mineralogical components of latosols of the Central Plateau of Brazil.

Com o objetivo de verificar o comportamento adsortivo de fosforo dos componentes mineralogicos da fracao argila, foram coletados amostras superficiais de oito solos, com textura e mineralogia variaveis. A goethita foi o principal componente dessa fracao responsavel pelas variacoes observadas na capacidade tampao maxima e na adsorcao maxima de fosforo

A biased random-key genetic algorithm with forward-backward improvement for the resource constrained project scheduling problem

This paper presents a biased random-key genetic algorithm for the resource constrained project scheduling problem. The chromosome representation of the problem is based on random keys. Active schedules are constructed using a priority-rule heuristic in which the priorities of the activities are defined by the genetic algorithm. A forward-backward improvement procedure is applied to all solutions. The chromosomes supplied by the genetic algorithm are adjusted to reflect the solutions obtained by the improvement procedure. The heuristic is tested on a set of standard problems taken from the literature and compared with other approaches. The computational results validate the effectiveness of the proposed algorithm

A random key based genetic algorithm for the resource constrained project scheduling problem

This paper presents a genetic algorithm for the Resource Constrained Project Scheduling Problem (RCPSP). The chromosome representation of the problem is based on random keys. The schedule is constructed using a heuristic priority rule in which the priorities of the activities are defined by the genetic algorithm. The heuristic generates parameterized active schedules. The approach was tested on a set of standard problems taken from the literature and compared with other approaches. The computational results validate the effectiveness of the proposed algorithm

New accuracy estimators for genomic selection with application in a cassava (Manihot esculenta) breeding program.

ABSTRACT. Genomic selection is the main force driving applied breeding programs and accuracy is the main measure for evaluating its efficiency. The traditional estimator (TE) of experimental accuracy is not fully adequate. This study proposes and evaluates the performance and efficiency of two new accuracy estimators, called regularized estimator (RE) and hybrid estimator (HE), which were applied to a practical cassava breeding program and also to simulated data. The simulation study considered two individual narrow sense heritability levels and two genetic architectures for traits. TE, RE, and HE were compared under four validation procedures: without validation (WV), independent validation, ten-fold validation through jacknife allowing different markers, and with the same markers selected in each cycle. RE presented accuracies closer to the parametric ones and less biased and more precise ones than TE. HE proved to be very effective in the WV procedure. The estimators were applied to five traits evaluated in a cassava experiment, including 358 clones genotyped for 390 SNPs. Accuracies ranged from 0.67 to 1.12 with TE and from 0.22 to 0.51 with RE. These results indicated that TE overestimated the accuracy and led to one accuracy estimate (1.12) higher than one, which is outside of the parameter space. Use of RE turned the accuracy into the parameter space. Cassava breeding programs can be more realistically implemented using the new estimators proposed in this study, providing less risky practical inferences

Variability of the anthracnose fungus Colletotrichum graminicola in sorghum genotype mixtures.

This paper reports partial results obtained on the variability of Colletotrichum graminicola developed in response to the host diversity generated by three-line combination of sorghum (Sorghum bicolor) genotypes. Nine sorghum lines were used in this study: CMSXS210B, CMSXS112B, CMSXS215B, CMSXS221B, CMSXS169R, CMSXS180R, CMSXS182R, CMSXS227R, and CMSXS116R. A total of 39 treatments on mixtures and pure stands of the component lines were evaluated in the field for the development of anthracnose, as a natural epidemic. Samples of the single spore isolates of the pathogen of each treatment indicated a reduction in the phenotypic diversity and an increase in the frequency of more complex races in genotype mixturesin relation to the pure stands of each genotype. O presente trabalho relata resultados parciais sobre a variabilidade de Colletotrichum graminicola, agente causal da antracnose do sorgo (Sorghum bicolor), desenvolvida em resposta à diversidade gerada na população hospedeira através de misturas formadas pela combinação, três a três, de diferentes linhagens de sorgo. Nove linhagens foram utilizadas neste estudo: CMSXS210B, CMSXS112B, CMSXS215B, CMSXS221B, CMSXS169R,CMSXS180R, CMSXS182R, CMSXS227R, and CMSXS116R. Misturas e estandes puros de cada linhagem componente, em um total de 39 tratamentos, foram avaliados no campo, para o desenvolvimento da antracnose em condições de infecção natural. Amostras de isolados monospóricos do patógeno obtidas de cada tratamento indicaram uma redução na diversidade fenotípica do patógeno e um aumento na freqüência de raças de maior complexidade em todas as misturas em relação aos estandes puros de cada genótipo