001     16500
005     20200702121602.0
024 7 _ |2 pmid
|a pmid:21786313
024 7 _ |2 DOI
|a 10.1002/etc.630
024 7 _ |2 WOS
|a WOS:000295309400024
037 _ _ |a PreJuSER-16500
041 _ _ |a eng
082 _ _ |a 690
084 _ _ |2 WoS
|a Environmental Sciences
084 _ _ |2 WoS
|a Toxicology
100 1 _ |a Gao, Z.
|b 0
|0 P:(DE-HGF)0
245 _ _ |a Improving Uncertainty Analysis in Kinetic Evaluations Using Iteratively Reweighted Least Squares
260 _ _ |a Lawrence, KS
|b SETAC [u.a.]
|c 2011
300 _ _ |a 2363 - 2371
336 7 _ |a Journal Article
|0 PUB:(DE-HGF)16
|2 PUB:(DE-HGF)
336 7 _ |a Output Types/Journal article
|2 DataCite
336 7 _ |a Journal Article
|0 0
|2 EndNote
336 7 _ |a ARTICLE
|2 BibTeX
336 7 _ |a JOURNAL_ARTICLE
|2 ORCID
336 7 _ |a article
|2 DRIVER
440 _ 0 |a Environmental Toxicology and Chemistry
|x 0730-7268
|0 1870
|y 10
|v 30
500 _ _ |3 POF3_Assignment on 2016-02-29
500 _ _ |a Record converted from VDB: 12.11.2012
520 _ _ |a Kinetic parameters of environmental fate processes are usually inferred by fitting appropriate kinetic models to the data using standard nonlinear least squares (NLS) approaches. Although NLS is appropriate to estimate the optimum parameter values, it implies restrictive assumptions on data variances when the confidence limits of the parameters must also be determined. Particularly in the case of degradation and metabolite formation, the assumption of equal error variance is often not realistic because the parent data usually show higher variances than those of the metabolites. Conventionally, such problems would be tackled by weighted NLS regression, which requires prior knowledge about the data errors. Instead of implicitly assuming equal error variances or giving arbitrary weights decided by the researcher, we use an iteratively reweighted least squares (IRLS) algorithm to obtain the maximum likelihood estimates of the model parameters and the error variances specific for the different species in a model. A study with simulated data shows that IRLS gives reliable results in the case of both unequal and equal error variances. We also compared results obtained by NLS and IRLS, with probability distributions of the parameters inferred with a Markov-Chain Monte-Carlo (MCMC) approach for data from aerobic transformation of different chemicals in soil. Confidence intervals obtained by IRLS and MCMC are consistent, whereas NLS leads to very different results when the error variances are distinctly different between different species. Because the MCMC results can be assumed to reflect the real parameter distribution imposed by the observed data, we conclude that IRLS generally yields more realistic estimates of confidence intervals for model parameters than NLS.
536 _ _ |a Terrestrische Umwelt
|c P24
|2 G:(DE-HGF)
|0 G:(DE-Juel1)FUEK407
|x 0
588 _ _ |a Dataset connected to Web of Science, Pubmed
650 _ 2 |2 MeSH
|a Algorithms
650 _ 2 |2 MeSH
|a Confidence Intervals
650 _ 2 |2 MeSH
|a Kinetics
650 _ 2 |2 MeSH
|a Least-Squares Analysis
650 _ 2 |2 MeSH
|a Likelihood Functions
650 _ 2 |2 MeSH
|a Markov Chains
650 _ 2 |2 MeSH
|a Models, Chemical
650 _ 2 |2 MeSH
|a Monte Carlo Method
650 _ 2 |2 MeSH
|a Uncertainty
650 _ 7 |a J
|2 WoSType
653 2 0 |2 Author
|a Kinetic evaluation
653 2 0 |2 Author
|a Nonlinear optimization
653 2 0 |2 Author
|a Degradation kinetic
653 2 0 |2 Author
|a Least squares
700 1 _ |a Green, J.W.
|b 1
|0 P:(DE-HGF)0
700 1 _ |a Vanderborght, J.
|b 2
|u FZJ
|0 P:(DE-Juel1)129548
700 1 _ |a Schmitt, W.
|b 3
|0 P:(DE-HGF)0
773 _ _ |a 10.1002/etc.630
|g Vol. 30, p. 2363 - 2371
|p 2363 - 2371
|q 30<2363 - 2371
|0 PERI:(DE-600)2027441-5
|t Environmental toxicology and chemistry
|v 30
|y 2011
|x 0730-7268
856 7 _ |u http://dx.doi.org/10.1002/etc.630
909 C O |o oai:juser.fz-juelich.de:16500
|p VDB
|p VDB:Earth_Environment
913 1 _ |k P24
|v Terrestrische Umwelt
|l Terrestrische Umwelt
|b Erde und Umwelt
|0 G:(DE-Juel1)FUEK407
|x 0
913 2 _ |a DE-HGF
|b Marine, Küsten- und Polare Systeme
|l Terrestrische Umwelt
|1 G:(DE-HGF)POF3-250
|0 G:(DE-HGF)POF3-259H
|2 G:(DE-HGF)POF3-200
|v Addenda
|x 0
914 1 _ |y 2011
915 _ _ |0 StatID:(DE-HGF)0010
|a JCR/ISI refereed
920 1 _ |k IBG-3
|l Agrosphäre
|g IBG
|0 I:(DE-Juel1)IBG-3-20101118
|x 0
970 _ _ |a VDB:(DE-Juel1)130550
980 _ _ |a VDB
980 _ _ |a ConvertedRecord
980 _ _ |a journal
980 _ _ |a I:(DE-Juel1)IBG-3-20101118
980 _ _ |a UNRESTRICTED


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