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Registro Completo |
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Biblioteca(s): |
Embrapa Pecuária Sul. |
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Data corrente: |
28/11/2011 |
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Data da última atualização: |
15/02/2012 |
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Tipo da produção científica: |
Resumo em Anais de Congresso |
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Autoria: |
LACA, E. A.; GENRO, T. C. M.; GENRO NETO, J. S. |
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Afiliação: |
EMILIO ANDRÉS LACA, University of California Davis, CA, USA; TERESA CRISTINA MORAES GENRO, CPPSUL; JAIRO SILVEIRA GENRO NETO, Universidade Federal de Santa Maria, RS, Brasil. |
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Título: |
Bayesian hierarchical models to improve estimation of diet composition by alkane profiles. |
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Ano de publicação: |
2011 |
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Fonte/Imprenta: |
In: REUNIÓN DE LA ASOCIACIÓN LATINOAMERICANA DE PRODUCCIÓN ANIMAL, 22., 2011, Montevideo, Uruguay. Memorias... Montevideo: Asociación Uruguaya de Producción Animal, 2011. |
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Descrição Física: |
1 CD-ROM. |
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Idioma: |
Inglês |
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Conteúdo: |
Alkane profiles in forage and feces are used to determine diet composition, essentially by inverting a linear mixing equation. Depending on the number of dietary components, number of alkanes and difference in forage profiles, the linear equations can be over or underdetermined. We compared the typical non-negative least squares (NNLS) method against a novel Bayesian hierarchical model (BHM) where diet composition is represented as latent variables modeled with parameters shared by the models for fecal and forage profiles. Forage and fecal profiles were obtained from steers grazing either Brachiaria brizantha cv Marandu, Panicum maximum cv. Mombaça, or Pennisetum purpureum cv. Cameroon at Embrapa Beef Cattle, Campo Grande, MS, Brazil. Herbage and fecal samples were collected in the dry and early wet seasons. Herbage was sampled by 20-cm horizons sorted into stem/sheath and leaf blade as dietary components. Feces were collected from 6 animals in the morning and afternoon. Fecal profiles were corrected by faecal recoveries using mean values from the literature. Distributions of diets estimated by NNLS were obtained by Monte Carlo simulation of profiles using parameters and covariance matrices estimated from data. The BHM yielded posterior distributions directly by using Monte Carlo Markov Chains. NNLS resulted in highly variables diets with distributions that were clearly non-normal. BHM resulted in quasi-normal posterior distributions. We conclude that both approaches are better than the normal approach where diet covariances are calculated ad-hoc. The BHM method has the potential to be vastly superior because it allows the simultaneous integration in a formally correct manner, however, convergence can be difficult. MenosAlkane profiles in forage and feces are used to determine diet composition, essentially by inverting a linear mixing equation. Depending on the number of dietary components, number of alkanes and difference in forage profiles, the linear equations can be over or underdetermined. We compared the typical non-negative least squares (NNLS) method against a novel Bayesian hierarchical model (BHM) where diet composition is represented as latent variables modeled with parameters shared by the models for fecal and forage profiles. Forage and fecal profiles were obtained from steers grazing either Brachiaria brizantha cv Marandu, Panicum maximum cv. Mombaça, or Pennisetum purpureum cv. Cameroon at Embrapa Beef Cattle, Campo Grande, MS, Brazil. Herbage and fecal samples were collected in the dry and early wet seasons. Herbage was sampled by 20-cm horizons sorted into stem/sheath and leaf blade as dietary components. Feces were collected from 6 animals in the morning and afternoon. Fecal profiles were corrected by faecal recoveries using mean values from the literature. Distributions of diets estimated by NNLS were obtained by Monte Carlo simulation of profiles using parameters and covariance matrices estimated from data. The BHM yielded posterior distributions directly by using Monte Carlo Markov Chains. NNLS resulted in highly variables diets with distributions that were clearly non-normal. BHM resulted in quasi-normal posterior distributions. We conclude that both approaches are bet... Mostrar Tudo |
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Palavras-Chave: |
Melhoramento forrageira; Modelo bayesiano; Perfil alcalino. |
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Categoria do assunto: |
K Ciência Florestal e Produtos de Origem Vegetal |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/48108/1/G158-pagina173poster.pdf
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Marc: |
LEADER 02430nam a2200181 a 4500
001 1907473
005 2012-02-15
008 2011 bl uuuu u00u1 u #d
100 1 $aLACA, E. A.
245 $aBayesian hierarchical models to improve estimation of diet composition by alkane profiles.$h[electronic resource]
260 $aIn: REUNIÓN DE LA ASOCIACIÓN LATINOAMERICANA DE PRODUCCIÓN ANIMAL, 22., 2011, Montevideo, Uruguay. Memorias... Montevideo: Asociación Uruguaya de Producción Animal$c2011
300 $c1 CD-ROM.
520 $aAlkane profiles in forage and feces are used to determine diet composition, essentially by inverting a linear mixing equation. Depending on the number of dietary components, number of alkanes and difference in forage profiles, the linear equations can be over or underdetermined. We compared the typical non-negative least squares (NNLS) method against a novel Bayesian hierarchical model (BHM) where diet composition is represented as latent variables modeled with parameters shared by the models for fecal and forage profiles. Forage and fecal profiles were obtained from steers grazing either Brachiaria brizantha cv Marandu, Panicum maximum cv. Mombaça, or Pennisetum purpureum cv. Cameroon at Embrapa Beef Cattle, Campo Grande, MS, Brazil. Herbage and fecal samples were collected in the dry and early wet seasons. Herbage was sampled by 20-cm horizons sorted into stem/sheath and leaf blade as dietary components. Feces were collected from 6 animals in the morning and afternoon. Fecal profiles were corrected by faecal recoveries using mean values from the literature. Distributions of diets estimated by NNLS were obtained by Monte Carlo simulation of profiles using parameters and covariance matrices estimated from data. The BHM yielded posterior distributions directly by using Monte Carlo Markov Chains. NNLS resulted in highly variables diets with distributions that were clearly non-normal. BHM resulted in quasi-normal posterior distributions. We conclude that both approaches are better than the normal approach where diet covariances are calculated ad-hoc. The BHM method has the potential to be vastly superior because it allows the simultaneous integration in a formally correct manner, however, convergence can be difficult.
653 $aMelhoramento forrageira
653 $aModelo bayesiano
653 $aPerfil alcalino
700 1 $aGENRO, T. C. M.
700 1 $aGENRO NETO, J. S.
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Registro original: |
Embrapa Pecuária Sul (CPPSUL) |
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| Registros recuperados : 139 | |
| 7. |  | MACHADO, E.; MAEDA, S. Efeito da mistura de lodo celulósico com cinza de biomassa de madeira no desenvolvimento de Pinus taeda L. In: EVENTO DE INICIAÇÃO CIENTÍFICA DA EMBRAPA FLORESTAS, 11., 2012, Colombo. Anais. Colombo: Embrapa Florestas, 2012. (Embrapa Florestas. Documentos, 240). Editores técnicos: Marcílio José Thomazini, Elenice Fritzsons, Patrícia Raquel Silva, Guilherme Schnell e Schuhli, Denise Jeton Cardoso, Luziane Franciscon. EVINCI. Resumos.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Florestas. |
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| 10. | | MAEDA, S.; PEREIRA, C. M. Formas de fósforo em solo submetido à aplicação de lodo celulósico. In: REUNIÃO BRASILEIRA DE CIÊNCIA DO SOLO E NUTRIÇÃO DE PLANTAS, 30.; REUNIÃO BRASILEIRA SOBRE MICORRIZAS, 14.; SIMPÓSIO BRASILEIRO DE MICROBIOLOGIA DO SOLO, 12.; REUNIÃO BRASILEIRA DE BIOLOGIA DO SOLO, 9.; SIMPÓSIO SOBRE SELÊNIO NO BRASIL, 1., 2012, Maceió. A responsabilidade socioambiental da pesquisa agrícola: anais. Viçosa, MG: SBCS, 2012. FERTBIO 2012. 3 p. CD-ROM. Resumo expandido.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Florestas. |
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| 17. | | SASS, A. L.; MAEDA, S. Uso de lodo celulósico e cinza de caldeira em reflorestamento de eucalipto. In: EVENTO DE INICIAÇÃO CIENTÍFICA DA EMBRAPA FLORESTAS, 12., 2013, Colombo. Anais. Colombo: Embrapa Florestas, 2013. (Embrapa Florestas. Documentos, 253). Editores técnicos: Marcílio José Thomazini, Elenice Fritzsons, Patrícia Raquel Silva, Guilherme Schnell e Schuhli, Denise Jeton Cardoso, Luziane Franciscon. EVINCI. Resumos.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Florestas. |
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| 18. | | BOGNOLA, I. A.; MAEDA, S. Tecnologias de precisão na silvicultura. Opiniões Florestal: Celulose, Papel, Carvão, Siderurgia, Painéis e Madeira, ano 13, n. 43, p. 37-38, mar./maio 2016.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: C - 0 |
| Biblioteca(s): Embrapa Florestas. |
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| 20. | | DUCHEIKO, H. A. S.; SOARES, M. T. S.; MAEDA, S. Alterações de fósforo, cobre e zinco em latossolo vermelho distrófico sob aplicação de dejeto suíno, no município de Assis Chateaubriand, Paraná. In: EVENTO DE INICIAÇÃO CIENTÍFICA DA EMBRAPA FLORESTAS, 19., 2020, Colombo. Anais. Colombo: Embrapa Florestas, 2020. p. 21. (Embrapa Florestas. Documentos, 343).| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Florestas. |
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| Registros recuperados : 139 | |
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