Methods to verify parameter equality in nonlinear regression models

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genetic trends in the expected progeny difference of the asymptotic weight of Nelore females

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Analysis of beef cattle longitudinal data applying a nonlinear model

The objective of this work was to evaluate the Nelore beef cattle, growth curve parameters using the Von Bertalanffy function in a nested Bayesian procedure that allowed estimation of the joint posterior distribution of growth curve parameters, their (co)variance components, and the environmental and additive genetic components affecting them. A hierarchical model was applied; each individual had a growth trajectory described by the nonlinear function, and each parameter of this function was considered to be affected by genetic and environmental effects that were described by an animal model. Random samples of the posterior distributions were drawn using Gibbs sampling and Metropolis-Hastings algorithms. The data set consisted of a total of 145,961 BW recorded from 15,386 animals. Even though the curve parameters were estimated for animals with few records, given that the information from related animals and the structure of systematic effects were considered in the curve fitting, all mature BW predicted were suitable. A large additive genetic variance for mature BW was observed. The parameter a of growth curves, which represents asymptotic adult BW, could be used as a selection criterion to control increases in adult BW when selecting for growth rate. The effect of maternal environment on growth was carried through to maturity and should be considered when evaluating adult BW. Other growth curve parameters showed small additive genetic and maternal effects. Mature BW and parameter k, related to the slope of the curve, presented a large, positive genetic correlation. The results indicated that selection for growth rate would increase adult BW without substantially changing the shape of the growth curve. Selection to change the slope of the growth curve without modifying adult BW would be inefficient because their genetic correlation is large. However, adult BW could be considered in a selection index with its corresponding economic weight to improve the overall efficiency of beef cattle production.

Características do crescimento morfométrico e composição corporal de girinos de rã-touro em cativeiro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ecofisiologia de morfotipos reto e espiralado de Cylindrospermopsis raciborskii (Cyanobacteria) em condições controladas

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

Curva de crescimento e exportação de nutrientes e sódio por frutos de mangueira Palmer, Haden e Tommy Atkins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Potencial de uso de gramíneas como substrato pasteurizado no cultivo do cogumelo Pleurotus ostreatus (Jacq.) P. Kumm

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Expressão e análise de proteínas recombinantes de Xanthomonas axonopodis pv. citri em E. coli, visando análise estrutural por cristalografia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização fenotípica e funcional de mutantes da bactéria fitopatogênica Xanthomonas citri subsp. citri

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fenologia, produção e qualidade dos frutos de cultivares de mangueira em condições subtropicais

Pós-graduação em Agronomia (Horticultura) - FCA

Avaliação do método de Iwatsu et al., (1981) para isolamento de leveduras negras do solo, degradadoras de hidrocarbonetos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento ponderal de bubalinos Murrah criados em pastagem de capim-marandu (Brachiaria Brizantha cv Marandu) no Estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modelos duplo sigmoidais para o crescimento de frutos do cafeeiro

Coffee is one of the main products of Brazilian agriculture, the country is currently the largest producer and exporter. Knowing the growth pattern of a fruit can assist in the development of culture indicating for example, the times of increased fruit weight and its optimum harvest, essential to improve the management and quality of coffee. Some authors indicate that the growth curve of the coffee fruit has a double sigmoid shape. However, it consists of just a visual observation without exploring the use of regression models. The aims of this study were: i) determine if the growth pattern of the coffee fruit is really double sigmoidal; ii) to propose a new approach in weighted importance re-sampling to estimate the parameters of regression models and select the most suitable double sigmoidal model to describe the growth of coffee fruits; iii) to study the spatial distribution effect of the crop in the growth curve of coffee fruits. In the first article the aim was determine if the growth pattern of the coffee fruit is really double sigmoidal. The models double Gompertz and double Logistic showed significantly superior fit to models of simple sigmoid confirming that the standard of coffee fruits growth is really double sigmoidal. In the second article we propose to consider an approximation of the likelihood as the candidate distribution of the weighted importance resampling, aiming to facilitate the process of obtaining samples of marginal distributions of each parameter. This technique was effective since it provided parameters with practical interpretation and low computational effort, therefore, it can be used to estimate parameters of double sigmoidal growth curves. The nonlinear model double Logistic was the most appropriate to describe the growth curve of coffee fruits. In the third article aimed to verify the influence of different planting alignments and sun exposure faces in the fruits growth curve. A difference between the growth rates in the two stages of fruit development was identified, regardless the side. Although it has been proven differences in productivity and quality of coffee, there was no difference between the growth curves in the different planting alignments herein studied.

Programa computacional para ajuste de curvas polinomiais em experimentos envolvendo dados longitudinais

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Modelos de crescimento e das respostas de frangas de postura submetidas a diferentes ingestões de aminoácidos sulfurados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)