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Registros recuperados: 11 | |
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Brook, Barry W; Northern Territory University; barry.brook@ntu.edu.au; Burgman, Mark A; University of Melbourne; m.burgman@botany.unimelb.edu.au; Frankham, Richard; Macquarie University; rfrankha@rna.bio.mq.edu.au. |
Population viability analysis (PVA) is used in conservation biology to predict extinction probabilities for threatened species. Previous studies have revealed large differences between the predictions of PVA modeling packages, but these comparisons included a range of nonstandard factors. A standardized comparison of five PVA packages (GAPPS, INMAT, RAMAS Metapop, RAMAS Stage, and VORTEX) was conducted on six examples (two mammals, two birds, one reptile, and a hypothetical bird/mammal-like life history). The individual-based packages (GAPPS and VORTEX) predicted a consistently higher risk of extinction than their matrix-based counterparts (INMAT and the RAMAS programs). This arose as only the former considered the effect of demographic stochasticity in... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Demographic stochasticity; Extinction risk; Individual-based models; Matrix-based models; Model comparison; Parameter estimation; Population viability analysis; Sex ratio. |
Ano: 2000 |
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Sacher,Johannes; Saa,Pedro; Cárcamo,Martín; López,Javiera; Gelmi,Claudio A; Pérez-Correa,Ricardo. |
Background: Calibration of dynamic models in biotechnology is challenging. Kinetic models are usually complex and differential equations are highly coupled involving a large number of parameters. In addition, available measurements are scarce and infrequent, and some key variables are often non-measurable. Therefore, effective optimization and statistical analysis methods are crucial to achieve meaningful results. In this research, we apply a metaheuristic scatter search algorithm to calibrate a solid substrate cultivation model. Results: Even though scatter search has shown to be effective for calibrating difficult nonlinear models, we show here that a posteriori analysis can significantly improve the accuracy and reliability of the estimation.... |
Tipo: Journal article |
Palavras-chave: Gibberella fujikuroi; Gibberellic acid; Global optimization; Metaheuristics; Nonlinear dynamic models; Parameter estimation; Solid substrate cultivation. |
Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582011000500007 |
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Pethybridge, Heidi; Weijerman, Mariska; Perrymann, Holly; Audzijonyte, Asta; Porobic, Javier; Mcgregor, Vidette; Girardin, Raphael; Bulman, Cathy; Ortega-cisneros, Kelly; Sinerchia, Matteo; Hutton, Trevor; Lozano-montes, Hector; Mori, Mao; Novaglio, Camilla; Fay, Gavin; Gorton, Rebecca; Fulton, Elizabeth. |
Calibration of complex, process-based ecosystem models is a timely task with modellers challenged by many parameters, multiple outputs of interest and often a scarcity of empirical data. Incorrect calibration can lead to unrealistic ecological and socio-economic predictions with the modeller’s experience and available knowledge of the modelled system largely determining the success of model calibration. Here we provide an overview of best practices when calibrating an Atlantis marine ecosystem model, a widely adopted framework that includes the parameters and processes comprised in many different ecosystem models. We highlight the importance of understanding the model structure and data sources of the modelled system. We then focus on several model outputs... |
Tipo: Text |
Palavras-chave: Best practices; Model diagnostics; Food web; Pedigree; Parameter estimation. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00516/62723/67160.pdf |
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Lupo, Coralie; Travers, Marie-agnes; Tourbiez, Delphine; Barthélémy, Clement; Beaunée, Gaël; Ezanno, Pauline. |
Vibrio aestuarianus is a bacterium related to mortality outbreaks in Pacific oysters, Crassostrea gigas, in France, Ireland, and Scotland since 2011. Knowledge about its transmission dynamics is still lacking, impairing guidance to prevent and control the related disease spread. Mathematical modeling is a relevant approach to better understand the determinants of a disease and predict its dynamics in imperfectly observed pathosystems. We developed here the first marine epidemiological model to estimate the key parameters of V. aestuarianus infection at a local scale in a small and closed oyster population under controlled laboratory conditions. Using a compartmental model accounting for free-living bacteria in seawater, we predicted the infection dynamics... |
Tipo: Text |
Palavras-chave: Marine epidemiology; Parameter estimation; Compartmental model; ABC method; Global sensitivity analysis; Basic reproduction number R-0; Crassostrea gigas; Oyster mortality. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00495/60652/64148.pdf |
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Vargas-Villamil,Luis Manuel; Ku-Vera,Juan Carlos; Vargas-Villamil,Felipe; Medina-Peralta,Salvador; Avila-Vales,Eric José; Aranda-Ibañez,Emilio Manuel; Avendaño-Reyes,Leonel. |
The objective of this study was to use the Turix model (a new mechanistic dynamic model that can be used for feed evaluation under tropical conditions), along with in situ and in vitro sugar cane experimental data from a previous study, to evaluate sugar cane kinetics through estimation of three parameters associated with ruminal bacterial growth: kM,SmL, the substrate uptake; kLM, the bacterial growth from intermediate metabolite; and Y VFAP,FS, the products related to volatile fatty acid yield. Values of these parameters for the whole sugar cane and its neutral detergent fiber (NDF) and acid detergent fiber (ADF) fractions were: a) kM, SmL, 16.20, 50.47 and 21.97 mL h-1 (mg M)-1 ; b) kLM, 96.00, 543.00 and 1,680.00 h-1 ; and, 1.02, 0.40 and 0.23 g g-1 ,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Model fitting; Parameter estimation; Ruminant; Simulation; Sugar cane. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000400009 |
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Milani,Marília; Lopes,Sidinei José; Bellé,Rogério Antônio; Backes,Fernanda Alice Antonello Londero. |
ABSTRACT: The objective of this study was to characterize the height (H) and leaf number (LN) of China pinks, grown in seven substrates, as a function of degree days, using the logistic growth model. H and LN were measured from 56 plants per substrate, for 392 plants in total. Plants that were grown on substrates formed of 50% soil with 50% rice husk ash (50% S + 50% RH) and 80% rice husk ash with 20% worm castings (80% RH + 20% W) had the longest vegetative growth period (74d), corresponding to 1317.9ºCd. The logistic growth model, adjusted for H, showed differences in the estimation of maximum expected height (α) between the substrates, with values between 10.47cm for 50% S + 50% RH and 35.75cm for Mecplant(r). When α was estimated as LN, variation was... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dianthus chinensis L; Growth model; Protected environment; Parameter estimation. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016001101924 |
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Registros recuperados: 11 | |
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