Cited by 166Gene Regulatory Network AnalysisControl Systems and IdentificationStatistical and numerical algorithms

Data-based identifiability analysis of non-linear dynamical models

Open access
Hengl, S., Kreutz, C., Timmer, J., Maiwald, T.·2007·Bioinformatics

Abstract

Motivation: Mathematical modelling of biological systems is becoming a standard approach to investigate complex dynamic, non-linear interaction mechanisms in cellular processes. However, models may comprise non-identifiable parameters which cannot be unambiguously determined. Non-identifiability manifests itself in functionally related parameters, which are difficult to detect. Results: We present the method of mean optimal transformations, a non-parametric bootstrap-based algorithm for identifiability testing, capable of identifying linear and non-linear relations of arbitrarily many parameters, regardless of model size or complexity. This is performed with use of optimal transformations, estimated using the alternating conditional expectation algorithm (ACE). An initial guess or prior knowledge concerning the underlying relation of the parameters is not required. Independent, and hence identifiable parameters are determined as well. The quality of data at disposal is included in our approach, i.e. the non-linear model is fitted to data and estimated parameter values are investigated with respect to functional relations. We exemplify our approach on a realistic dynamical model and demonstrate that the variability of estimated parameter values decreases from 81 to 1% after detection and fixation of structural non-identifiabilities. Availability: Our algorithm is written in Matlab and R. It is available from the authors on request. An implementation of ACE, written in Matlab as well as in C, is available online at www.stefanhengl.de Contact: hengl@fdm.uni-freiburg.de Supplementary information: Supplementary data are available at Bioinformatics online.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1093/bioinformatics/btm382

Cites

13 of 13 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The Hengl et al. (2007) approach detects structural non-identifiability via functional relations for arbitrary models but is not intended to detect practical non-identifiability.

    “An approach to detect structural non-identifiability by the corresponding functional relations was introduced by Hengl et al. (2007).It is able to detect flatness of likelihood for arbitrary models, but it is not intended to detect practical non-identifiability.”

    From Structural and practical identifiability analysis of partially observed dynamical models by exploiting the profile likelihood (2009) · cites this paper as Hengl et al., 2007

    The Approach and Conclusion describe detecting structural non-identifiability through functionally related parameters in nonlinear models. But the Introduction explicitly lists practical identifiability analysis, accounting for data quality, as an aim of the method, contrary to the claim that it is not intended for that purpose. The passages do not specifically describe the method as detecting likelihood flatness. (LLM, conf=0.90)

    Experimental — accuracy not yet measured
  • Non-identifiability of our model arises in part because the quantity, quality and type of data are inadequate and relationships among parameters and experimental observables are inherently non-unique.

    “Non-identifiability of our model arises in part because the quantity, quality and type of data are inadequate and relationships among parameters and experimental observables are inherently non-unique (Hengl et al, 2007).”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 3

  1. [5]5. Godfrey,K.R. and DiStefano, J.J. (1987) Identifiabiliy of Model Parameters in Identifiability of Parametric Models, Chapter 1. Pergamon Press, Oxford, pp. 1-20.
  2. [7]7. Lecourtier,Y. et al. (1987) Volterra and Generating Power Series Approach to Identifiability Testing in Identifiability of Parametric Models, Chapter 5. Pergamon Press, Oxford, pp. 50-66.
  3. [12]12. Seber,G. and Wild,C. (1988) Nonlinear Regression. Wiley, New York.

Cited by

Sorted by citations

Authors
Hengl, S., Kreutz, C., Timmer, J., & Maiwald, T.
Affiliations
University of Freiburg (DE)
Corresponding author
Hengl, S.
Venue
Bioinformatics
Published
2007-07-28
Volume
23
Issue
19
Pages
2612-2618
ISSN
  • 1367-4803 (ISSN-L)
  • 1367-4811
OpenAlex
W2130191588
Cited by
166
References
13
Citations by year
2026: 4 · 2025: 1 · 2024: 7 · 2023: 5 · 2022: 4 · 2021: 10 · 2020: 7 · 2019: 5 · 2018: 6 · 2017: 3 · 2016: 13 · 2015: 14 · 2014: 12 · 2013: 14 · 2012: 12
FWCI
4.24
Type
journal article
Language
en
Open access
Locations
  • Bioinformatics (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Deutsches Krebsforschungszentrum
  • Bundesministerium für Bildung und Forschung (0313074D)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gene Regulatory Network Analysis
  • Physical Sciences › Engineering › Control and Systems Engineering › Control Systems and Identification
  • Physical Sciences › Mathematics › Applied Mathematics › Statistical and numerical algorithms
Keywords
parameter identifiability, alternating conditional expectation, biological systems modelling, data quality assessment
MeSH terms
Algorithms, Artificial Intelligence, Computer Simulation, Models, Biological, Pattern Recognition, Automated, Signal Transduction, Databases, Factual, Information Storage and Retrieval, Nonlinear Dynamics, Proteome

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review