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Fitting ecological and physiological data to rectangular hyperbolae: a comparison of methods using Monte Carlo simulations
Citation
Berges, JA and Montagnes, DJS and Hurd, CL and Harrison, PJ, Fitting ecological and physiological data to rectangular hyperbolae: a comparison of methods using Monte Carlo simulations, Marine Ecology Progress Series, 114 pp. 175-183. ISSN 0171-8630 (1994) [Refereed Article]
Copyright Statement
Copyright 1994 Inter-Research
Official URL: http://www.int-res.com.ezproxy.utas.edu.au/article...
Abstract
Recommendations were developed to help aquatic scientists select which curve fitting
method should be used to fit data that are expected to follow rectangular hyperbolic relationships. Rectangular
hyperbolae of the form V = (VmaxS)/(Km + S), where V is a biological rate and S is the concentration
of some substrate, are widely used by researchers to model the kinetics of processes such as
enzyme activity versus substrate concentration, nutrient uptake versus nutrient concentration, and
grazing and growth rate versus prey concentration. A variety of procedures exist to estimate the parameters
Vmax (the rate of the process at saturating substrate concentration) and Km, (the concentration of
S at which half the saturated rate is achieved). There has been extensive discussion in the biochemical
and ecological literature as to which fitting method is most appropriate, based largely on theoretical
and statistical considerations. However, the assumptions inherent in these fitting procedures are typically
violated by the data obtained in many field and laboratory studies, e.g. the measurement of S has
an associated error, or error levels in the measurement of V may not be constant across S. Thus, there
is a problem predicting a priori which fitting method should be used. In this study, this problem was
approached using Monte Carlo simulations. Data sets with known Vmax and Km were constructed for 5
different data cases, ranging from data sets where saturation was not achieved to data sets where very
few sub-saturated measurements were available. Random, normally distributed errors were assigned
to each point based on a 10 %, 20 % or 50 % constant or variable error in the estimate of V, or 20 % error
in both S and V Six fitting procedures were applied including linear methods (Lineweaver-Burk;
Eadie-Hofstee; Hanes-Woolf), the median method (Eisenthal and Cornish-Bowden), and non-linear
least-squares methods (Cleland-Wilkinson; Tseng-Hsu). Non-linear methods were generally superior,
but for data sets with low error (10%) all methods gave almost equally accurate results. Data with constant
error were more difficult to fit than those where error varied with V. Criteria for selecting a fitting method based on data characteristics are discussed and applied to actual data sets
Item Details
Item Type: | Refereed Article |
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Keywords: | modelling physiological responses, seaweed, invertebrates, microalgae |
Research Division: | Biological Sciences |
Research Group: | Ecology |
Research Field: | Ecological physiology |
Objective Division: | Expanding Knowledge |
Objective Group: | Expanding knowledge |
Objective Field: | Expanding knowledge in the biological sciences |
UTAS Author: | Hurd, CL (Professor Catriona Hurd) |
ID Code: | 93177 |
Year Published: | 1994 |
Deposited By: | IMAS Research and Education Centre |
Deposited On: | 2014-07-15 |
Last Modified: | 2014-08-01 |
Downloads: | 0 |
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