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| Registros recuperados: 11 | |
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| Macedo,Osmar Jesus; Barbin,Décio; Mourão,Gerson Barreto. |
| Covariance functions and random regression models have been considered as an alternative for data adjustment, in sequence, stemming from the same animal along time and which presents a structured pattern of covariance. Aiming to evaluate the performance of random regression models based on the Legendre, modified Jacobi and trigonometric functions, data concerning the weights of Nellore breed animals were used from birth to the 800th day of life, in models that assumed direct additive and animal permanent environmental effects coefficients. The Schwarz Bayesian information criterion (BIC) led to the selection of the models Legendre of order six (ML6), Jacobi of order five (MJ5) and trigonometric of order six (MT6), the ML6 model presenting the lowest BIC.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Additive variance; Heritability; Jacobi; Legendre; Longitudinal data. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000400014 |
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| Silva,Fabyano Fonseca e; Zambrano,Maria Fernanda Betancur; Varona,Luis; Glória,Leonardo Siqueira; Lopes,Paulo Sávio; Silva,Marcos Vinícius Gualberto Barbosa; Arbex,Wagner; Lázaro,Sirlene Fernandes; Resende,Marcos Deon Vilela de; Guimarães,Simone Eliza Facioni. |
| ABSTRACT: Genome association analyses have been successful in identifying quantitative trait loci (QTLs) for pig body weights measured at a single age. However, when considering the whole weight trajectories over time in the context of genome association analyses, it is important to look at the markers that affect growth curve parameters. The easiest way to consider them is via the two-step method, in which the growth curve parameters and marker effects are estimated separately, thereby resulting in a reduction of the statistical power and the precision of estimates. One efficient solution is to adopt nonlinear mixed models (NMM), which enables a joint modeling of the individual growth curves and marker effects. Our aim was to propose a genome association... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: SNP markers; Body weight; Longitudinal data. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162017000100001 |
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| COSTA, W. G. da; SANTOS, I. G. dos; SILVA JÚNIOR, A. C. da; CRUZ, C. D.; NASCIMENTO, M.; FERREIRA, R. de P.; VILELA, D.. |
| The aim of this study was to obtain estimates of genetic parameters via meta-analysis and mixed models to evaluate the potential of the germplasm from Embrapa Pecuaria Sudeste for integration in breeding programs. Data on the dry matter yield of 77 accessions evaluated in 24 harvests were used. Descriptive analysis was performed for mixed model and meta-analytical estimates. The variances for each parameter were estimated. For the meta-analysis, variances were used as weighting measures, and the fixed and random models were tested. A diagonal structure was considered for the residual variance matrix. Mean dry matter yield ranged from 1019.5 to 2684 kg ha-1. The phenotypic, permanent environmental, and genotypic variances oscillated widely throughout the... |
| Tipo: Artigo de periódico |
Palavras-chave: Longitudinal data; Genetic estimates; Estimativa genética; Dados longitudinais; Medicago Sativa; Alfafa; Meta-analysis. |
| Ano: 2021 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1135248 |
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| SILVA, F. F.; ROCHA, G. S.; RESENDE, M. D. V. de; GUIMARÃES, S. E. F.; PETERNELLI, L. A.; DUARTE, D. A. S.; AZEVEDO, C.. |
| Foi proposta uma metodologia para avaliação genética de curvas de crescimento considerando-se informações de marcadores SNPs (Single Nucleotide Polymorphisms). Em um primeiro passo foram ajustados modelos de crescimento não lineares (logístico) aos dados de peso-idade de cada animal, e em um segundo passo as estimativas dos parâmetros de tais modelos foram consideradas como fenótipos em um modelo de regressão (LASSO Bayesiano ? BL) cujas covariáveis foram os genótipos dos marcadores SNPs. Este enfoque possibilitou estimar os valores genéticos genômicos (GBV) para peso em qualquer tempo da trajetória de crescimento, refletindo na confecção de curvas de crescimento genômicas, as quais permitiram a identificação de grupos de indivíduos geneticamente... |
| Tipo: Separatas |
Palavras-chave: Melhoramento genético; SNP; Dados longitudinais; LASSO bayesiano; Longitudinal data; Bayesian LASSO. |
| Ano: 2013 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/974473 |
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| Melhim, Almuhanad; O'Donoghue, Erik J.; Shumway, C. Richard. |
| Recent consolidation in agriculture has shifted production toward fewer but larger farms, reshaping business relationships between farmers, processors, input suppliers, and local communities. We analyze growth and diversification of U.S. corn, wheat, apple, and beef farms by examining longitudinal changes in 10 size cohorts through three successive censuses. We fail to reject Gibrat’s law in apple and wheat industries and the mean reversion hypothesis in beef and corn industries. Apple and wheat farms diversify over time. The findings suggest that scale economies diminish for large farms across all four industries and scope economies dominate scale economies for large apple and wheat farms. |
| Tipo: Journal Article |
Palavras-chave: Diversification; Firm growth; Gibrat’s law; Longitudinal data; Scale economies; Scope economies; Agribusiness; Farm Management; Production Economics; Q12. |
| Ano: 2009 |
URL: http://purl.umn.edu/48757 |
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| Registros recuperados: 11 | |
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