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| Elvarsson, B. P.; Taylor, L.; Trenkel, Verena; Kupca, V.; Stefansson, G.. |
| Statistical models of marine ecosystems use a variety of data sources to estimate parameters using composite or weighted likelihood functions with associated weighting issues and questions on how to obtain variance estimates. Regardless of the method used to obtain point estimates, a method is required for variance estimation. A bootstrap technique is introduced for the evaluation of uncertainty in such models, taking into account inherent spatial and temporal correlations in the datasets, which are commonly transferred as assumptions from a likelihood estimation procedure into Hessian-based variance estimation procedures. The technique is demonstrated on a real dataset and the effects of the number of bootstrap samples on estimation bias and variance... |
| Tipo: Text |
Palavras-chave: Bootstrapping; Correlated data; Fish population dynamics; Non-linear models. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00193/30459/29913.pdf |
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| Tholon,P; Queiroz,SA. |
| Growth curves models provide a visual assessment of growth as a function of time, and prediction body weight at a specific age. This study aimed at estimating tinamous growth curve using different models, and at verifying their goodness of fit. A total number 11,639 weight records from 411 birds, being 6,671 from females and 3,095 from males, was analyzed. The highest estimates of a parameter were obtained using Brody (BD), von Bertalanffy (VB), Gompertz (GP,) and Logistic function (LG). Adult females were 5.7% heavier than males. The highest estimates of b parameter were obtained in the LG, GP, BD, and VB models. The estimated k parameter values in decreasing order were obtained in LG, GP, VB, and BD models. The correlation between the parameters a and k... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Growth parameters; Growth evaluation; Non-linear models; Wild birds. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2007000100004 |
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| Silva,Mário Henrique Magalhães Araújo da; Malhado,Carlos Henrique Mendes; Kern,Elisandra Lurdes; Daltro,Darlene dos Santos; Cobuci,Jaime Araujo; Carneiro,Paulo Luiz Souza. |
| ABSTRACT The objective of this study was to evaluate inbreeding depression in Holstein cows in Brazil, considering their 305-day milk production (MP), age of first calving (AFC), and calving interval (CI). The effects of inbreeding depression on the traits were determined using four regression models (linear, quadratic, exponential, and Michaelis-Menten) about the errors generated by the animal model. The linear model was significant for CI, and the quadratic model was significant for CI and AFC. The Michaelis-Menten and exponential models were significant for MP, AFC, and CI. Inbreeding depression affected MP and CI. Cows with inbreeding coefficient of 15% produced approximately 260 kg less milk than non-inbred cows. A 1% increase in the inbreeding level... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calving interval; Inbreeding coefficient; Linear models; Non-linear models. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982019000100307 |
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| Teixeira, Cícero Monti; EPAMIG; Carvalho, Gabriel José de; UFLA; Andrade, Messias José Bastos de; UFLA; Silva, Carlos Alberto; UFLA; Pereira, Janser Moura; UFU. |
| O objetivo foi avaliar a produção de fitomassa, o acúmulo e liberação de macronutrientes, e a decomposição das palhadas de milheto (Pennisetum typhoides (Burm.) Stapf) solteiro e consorciado com crotalária (Crotalaria juncea), sob a cultura do feijoeiro. O delineamento foi o de blocos casualizados, com quatro repetições, em esquema de parcelas subdivididas. As parcelas foram constituídas pelas duas palhadas; as subparcelas, pelas épocas de avaliação, ao longo do cultivo do feijoeiro (0, 8, 16, 24, 40, 56 e 72 dias após a semeadura). Os resíduos coletados foram secos em estufa de circulação forçada de ar, a 65ºC, até atingirem massa constante, para a determinação da matéria seca remanescente. Posteriormente, foram moídos e encaminhados para laboratório,... |
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Palavras-chave: 5.01.03.04-0 Produção de Mudas ciclagem de nutrientes; Litter-bags; Decomposição; Modelos não-lineares; Consórcio gramínea x leguminosa. 5.01.01.03-0 nutrient cycling; Litter bags; Decomposition; Non-linear models; Grass x leguminous intercropping.. |
| Ano: 2009 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/1356 |
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| Ferreira,Abílio G.T.; Henrique,Douglas S.; Vieira,Ricardo A.M.; Maeda,Emilyn M.; Valotto,Altair A.. |
| The objective of this study was to evaluate four mathematical models with regards to their fit to lactation curves of Holstein cows from herds raised in the southwestern region of the state of Parana, Brazil. Initially, 42,281 milk production records from 2005 to 2011 were obtained from "Associação Paranaense de Criadores de Bovinos da Raça Holandesa (APCBRH)". Data lacking dates of drying and total milk production at 305 days of lactation were excluded, resulting in a remaining 15,142 records corresponding to 2,441 Holstein cows. Data were sorted according to the parity order (ranging from one to six), and within each parity order the animals were divided into quartiles (Q25%, Q50%, Q75% and Q100%) corresponding to 305-day lactation yield. Within each... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dairy cattle; Milk yield; Mathematical models selection; Non-linear models. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652015000100503 |
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