Covariances
Mostrando 1-12 de 65 artigos, teses e dissertações.
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1. Impact of reproductive and productive rates on levels of inbreeding and genetic gain of pigs through data simulation
ABSTRACT The objective of this study was to evaluate the impact of farrowing and mortality rates on inbreeding levels and genetic gain through data simulation. Data came from two real populations A and B, composed of Pietrain and Landrace breed pigs, respectively. To generate the simulated populations, a Fortran-language simulator was developed using the (co
R. Bras. Zootec.. Publicado em: 15/08/2019
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2. Strategies to control inbreeding in a pig breeding program: a simulation study
RESUMO: O objetivo deste estudo foi avaliar, por meio de simulação de dados, o impacto das restrições no número máximo de irmãos completos e meios-irmãos selecionados para machos e fêmeas no nível de endogamia e ganho genético do rebanho. Os dados originais são provenientes das populações reais A e B, compostas por suínos da raça Pietrain e
Cienc. Rural. Publicado em: 10/07/2019
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3. Heritability estimation and genetic correlations for mature weight, visual scores, and growth traits in Nellore cattle
ABSTRACT This study was intended to estimate the genetic associations between growth traits and visual scores with possible changes in mature weight (MW) in 397,900 Nellore animals. A bi-character analysis was performed to estimate the (co)variances and genetic parameters for MW, which comprises the following traits: conformation, finishing precocity, muscul
R. Bras. Zootec.. Publicado em: 10/06/2019
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4. Heritability of advertisement call properties of the Japanese quail
Resumo O objetivo deste estudo foi investigar as variâncias e covariâncias genéticas entre as características do canto de anúncio de codornas japonesas. A duração da primeira, segunda e terceira sílaba, o comprimento do intervalo 1 (entre a primeira e a segunda sílaba), o intervalo 2 (entre a segunda e a terceira sílaba) e o amortecimento (extensã
Braz. J. Biol.. Publicado em: 30/05/2019
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5. Associations among growth, scrotal circumference, and visual score of beef cattle in performance tests on pasture or in feedlots
ABSTRACT This study aimed to evaluate associations among final weight (FW), average daily gain (ADG), scrotal circumference (SC), and visual score (VS) of beef cattle in performance tests on pasture or in feedlots. Genetic parameters for FW, ADG, SC, and VS of young Nellore bulls performance-tested on pasture or in feedlots were evaluated by mixed model. The
R. Bras. Zootec.. Publicado em: 2017-04
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6. Estudo das covariâncias envolvidas no método k0 de análise por ativação neutrônica / Study of covariances involved in the k0 method of neutron activation analysis
O presente trabalho se propôs ao desenvolvimento de uma metodologia para o tratamento das incertezas do método k0 de Análise por Ativação Neutrônica (AAN), de forma abrangente e acurada, aplicando a metodologia de Análise por Covariâncias. Todos os parâmetros envolvidos na determinação da concentração de um elemento estudado foram analisados de
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/12/2011
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7. Análise comparativa dos padrões de covariação genética e fenotípica no crânio e mandíbula de Calomys expulsus (Rodentia: Muroidea) / Comparative analysis of phenotypic and genetic covariances in the skull and mandible of the vesper mouse Calomys expulsus (Rodentia: Muroidea)
Os padrões de covariância genética entre caracteres, expressos pela matriz de covariância aditiva G, desempenham um papel importante na evolução de morfologias complexas, visto que esta matriz influencia a direção e magnitude da resposta à seleção em uma população. Assumindo-se a estabilidade da matriz G ao longo do tempo, pode-se testar explici
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/04/2011
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8. Selection objectives and criteria for sheep in Central Brazil
Three production systems for sheep (Low - L, Medium - M and High - H technology), with increasing technological levels, were studied under conditions in the Center-west of Brazil, to determine economic weights and selection indices of important traits. Receipts and costs were simulated using an economic simulator to calculate the structure of the operational
R. Bras. Zootec.. Publicado em: 2011-12
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9. Use of direct and iterative solvers for estimation of SNP effects in genome-wide selection
The aim of this study was to compare iterative and direct solvers for estimation of marker effects in genomic selection. One iterative and two direct methods were used: Gauss-Seidel with Residual Update, Cholesky Decomposition and Gentleman-Givens rotations. For resembling different scenarios with respect to number of markers and of genotyped animals, a simu
Genetics and Molecular Biology. Publicado em: 26/02/2010
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10. Assimilação de dados com redes neurais artificiais em modelo de circulação geral da atmosfera / Data assimilation with artificial neural networks in atmospheric general circulation model
Weather forecasting systems require a model for the time evolution and an estimate of the current state of the system. The numerical weather prediction (NWP) incorporates the equations of atmospheric dynamics with physical process and it can predict the future state of the atmosphere. Data assimilation provides such an initial estimate of the atmosphere wher
Publicado em: 2010
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11. Inverse problem in proton-proton elastic scattering in the impact parameter representations / Problema inverso do espalhamento elastico proton-proton na representacao de parametro de impacto
The Impact Parameter and Eikonal Representations are investigated by means of an empirical analysis of the experimental data on proton-proton elastic scattering, at the highest energy region with experimental information available (six data sets at center of mass energies 19.4 - 62.5 GeV). Making use of a novel model-independent parametrization for the scatt
Publicado em: 2009
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12. Effect of data structure on estimates of (co) variances of the weight of breast-in beef cattle, using simulated data / EFEITO DA ESTRUTURA DOS DADOS SOBRE AS ESTIMATIVAS DE (CO)VARIÂNCIAS DE PESO À DESMAMA EM BOVINOS DE CORTE, USANDO DADOS SIMULADOS
The objective was to evaluate the effects of the year (sample size, genealogy and data structure), mother-offspring link proportion (mother-offspring pairs, both with weaning weights), inclusion (M2) or not (M1) of the genetic direct-maternal covariance in the model, the direct-maternal correlation (C) magnitude and the direct and maternal genetic variance r
Publicado em: 2009