pith. sign in

arxiv: 2604.15598 · v2 · pith:4GWWMXNQnew · submitted 2026-04-17 · 🌊 nlin.CG · q-bio.QM· stat.AP

When do trajectories matter? Identifiability analysis for stochastic transport phenomena

Pith reviewed 2026-05-19 17:10 UTC · model grok-4.3

classification 🌊 nlin.CG q-bio.QMstat.AP
keywords identifiability analysisstochastic transportrandom walktrajectory datacount datadiffusionparameter estimationlattice model
0
0 comments X

The pith

Collecting individual trajectories resolves structural non-identifiability in stochastic diffusion models when count data alone fails.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper investigates how well parameters in a lattice-based random walk model of population dispersal can be estimated from different types of data. It finds that count data from fixed sampling regions can sometimes result in structural non-identifiability, where distinct parameter values produce the same population-level behavior. Incorporating trajectory data from individuals removes this issue and allows better comparison of experimental designs. A sympathetic reader would care because this guides efficient data collection in studies of animal, plant, or cell movement.

Core claim

The analysis of a lattice-based random walk model demonstrates that count data collected across a series of fixed sampling regions can lead to structural non-identifiability of the model parameters. This non-identifiability is alleviated by the collection of individual trajectory data. The combination of agent-based stochastic simulations, mean-field partial differential equation approximations, likelihood-based estimation, and identifiability analysis shows how different trajectory data collection protocols impact practical identifiability and model predictions.

What carries the argument

A combined identifiability analysis using agent-based simulations and mean-field PDE approximations to compare the inferential power of count data versus trajectory data in a random walk model.

If this is right

  • Structural non-identifiability can be detected through the use of mean-field approximations and likelihood estimation.
  • Practical identifiability improves with specific choices of trajectory sampling protocols.
  • Model-based predictions of population dispersal become more reliable when both data types are available.
  • Open-source code allows testing the approach on other stochastic transport models.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Field studies of dispersal might benefit from investing in individual tracking even at small scales.
  • Similar identifiability issues could arise in other stochastic models beyond lattice random walks.
  • Optimal experimental design in population biology could incorporate both aggregate and individual-level observations routinely.

Load-bearing premise

The lattice-based random walk model accurately represents the underlying stochastic transport phenomena and mean-field PDE approximations are valid in the regimes studied.

What would settle it

Observing that count data from a real system yields a unique parameter set without trajectory data would falsify the existence of structural non-identifiability in this modeling framework.

Figures

Figures reproduced from arXiv: 2604.15598 by Matthew J Simpson, Michael J Plank.

Figure 1
Figure 1. Figure 1: Schematic snapshot of a random walk process involving a population of individuals [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Visualization of the random walk model. Snapshots in the left column correspond [PITH_FULL_IMAGE:figures/full_fig_p008_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Continuum-discrete comparison for the simulation data from Figure 2. Profiles [PITH_FULL_IMAGE:figures/full_fig_p015_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Estimation and identifiability for unbiased motility using data from Figure 2. (a)– [PITH_FULL_IMAGE:figures/full_fig_p021_4.png] view at source ↗
Figure 7
Figure 7. Figure 7: Likelihood-based prediction for unbiased motion with data taken from Figure 2(e) [PITH_FULL_IMAGE:figures/full_fig_p029_7.png] view at source ↗
read the original abstract

Stochastic models of diffusion are routinely used to study dispersal of populations, including populations of animals, plants, seeds and cells. Advances in imaging and field measurement technologies mean that data are often collected across a range of scales, including count data collected across a series of fixed sampling regions to characterize population-level dispersal, as well as individual trajectory data to examine at the motion of individuals within a diffusive population. In this work we consider a lattice-based random walk model and examine the extent to which model parameters can be determined by collecting count data and/or trajectory data. Our analysis combines agent-based stochastic simulations, mean-field partial differential equation approximations, likelihood-based estimation, identifiability analysis, and model-based prediction. These combined tools reveal that working with count data alone can sometimes lead to challenges involving structural non-identifiability that can be alleviated by collecting trajectory data. Furthermore, these tools allow us to explore how different experimental designs impact inferential precision by comparing how different trajectory data collection protocols affects practical identifiability. Open source implementations of all algorithms used in this work are available on GitHub.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript examines parameter identifiability in a lattice-based random walk model of stochastic transport and dispersal. It combines agent-based stochastic simulations, mean-field PDE approximations, likelihood-based estimation, and formal identifiability analysis to argue that count data collected over fixed regions can produce structural non-identifiability, while the addition of individual trajectory data alleviates this issue. The work also compares different trajectory sampling protocols for their effect on practical identifiability and provides open-source code.

Significance. If the central claim holds for the underlying stochastic process, the results offer concrete guidance on experimental design for inferring dispersal parameters from population count versus trajectory data in ecology, cell biology, and related fields. The combination of simulation, approximation, and identifiability tools, together with reproducible code, strengthens the practical utility of the findings.

major comments (2)
  1. [Methods and Results] The identifiability diagnostics and likelihood construction rely on mean-field PDE approximations (see the description of the analysis pipeline). Because the PDE is a large-population limit, any structural non-identifiability (flat likelihood ridges) detected under the PDE could be an artifact that disappears when the exact stochastic master equation or simulation-based likelihood is used. The central claim that “count data alone can sometimes lead to structural non-identifiability” for the stochastic transport process therefore requires explicit verification on the discrete lattice model.
  2. [Identifiability analysis] The manuscript should demonstrate that the reported non-identifiability persists (or is relieved) when the likelihood is evaluated directly from the agent-based stochastic realizations rather than from the PDE surrogate. Without this check, the conclusion that trajectory data alleviates a genuine feature of the stochastic process remains conditional on the validity of the continuum approximation in the relevant parameter regimes.
minor comments (2)
  1. Specify the exact parameter combinations that become structurally non-identifiable under count data (e.g., diffusion coefficient versus reaction rate) and report the corresponding profile likelihood or Hessian eigenvalues.
  2. Ensure the GitHub repository link is included in the final version and that the code for both the stochastic simulations and the PDE-based likelihood is clearly documented with example scripts.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their careful reading and constructive comments, which highlight an important aspect of validating our identifiability results. We address the concerns regarding the mean-field PDE approximation versus direct stochastic verification point by point below.

read point-by-point responses
  1. Referee: The identifiability diagnostics and likelihood construction rely on mean-field PDE approximations (see the description of the analysis pipeline). Because the PDE is a large-population limit, any structural non-identifiability (flat likelihood ridges) detected under the PDE could be an artifact that disappears when the exact stochastic master equation or simulation-based likelihood is used. The central claim that “count data alone can sometimes lead to structural non-identifiability” for the stochastic transport process therefore requires explicit verification on the discrete lattice model.

    Authors: We agree that explicit verification on the discrete lattice model is necessary to confirm that the structural non-identifiability is a genuine feature of the stochastic process rather than an artifact of the continuum limit. Although the manuscript already employs agent-based simulations to generate data and explore model behavior, the formal identifiability analysis and likelihood construction were performed using the PDE surrogate for tractability. In the revised manuscript we will add a dedicated subsection that constructs and evaluates likelihoods directly from ensembles of agent-based stochastic realizations for the parameter regimes previously identified as non-identifiable under the PDE. This will include profile-likelihood comparisons for count data alone and with added trajectory observations, thereby directly testing the central claim on the underlying stochastic model. revision: yes

  2. Referee: The manuscript should demonstrate that the reported non-identifiability persists (or is relieved) when the likelihood is evaluated directly from the agent-based stochastic realizations rather than from the PDE surrogate. Without this check, the conclusion that trajectory data alleviates a genuine feature of the stochastic process remains conditional on the validity of the continuum approximation in the relevant parameter regimes.

    Authors: We accept this recommendation and will perform the requested demonstration. The revised version will include new figures and text showing likelihood surfaces obtained from direct simulation-based inference on the agent-based model. These results will confirm that flat ridges associated with count data persist in the discrete stochastic setting, while the addition of trajectory data removes the structural non-identifiability and improves practical identifiability. The analysis will be conducted both in regimes where the mean-field approximation is accurate and at smaller population sizes to assess robustness, thereby removing the conditional nature of the current conclusions. revision: yes

Circularity Check

0 steps flagged

No significant circularity; analysis relies on external simulations and likelihood methods

full rationale

The paper's core claim—that count data can induce structural non-identifiability alleviated by trajectory data—is supported by agent-based stochastic simulations, mean-field PDE approximations, and likelihood-based estimation performed against independently generated data. No derivation step reduces a prediction or identifiability diagnostic to a fitted parameter by construction, nor does any load-bearing premise collapse to a self-citation chain. The analysis remains self-contained against external benchmarks, consistent with the reader's assessment of score 2.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Limited information from abstract only; no specific free parameters or invented entities mentioned. The model choice itself functions as a domain assumption.

axioms (1)
  • domain assumption The stochastic process is a lattice-based random walk
    Central modeling choice invoked for all simulations and approximations.

pith-pipeline@v0.9.0 · 5724 in / 1009 out tokens · 55758 ms · 2026-05-19T17:10:03.635746+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

What do these tags mean?
matches
The paper's claim is directly supported by a theorem in the formal canon.
supports
The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends
The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses
The paper appears to rely on the theorem as machinery.
contradicts
The paper's claim conflicts with a theorem or certificate in the canon.
unclear
Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Identifiability Limits of Physics-Informed Inference for Spatial Stochastic Dynamics from Static Snapshots

    q-bio.QM 2026-07 unverdicted novelty 7.0

    Structural identifiability analysis shows point sources restore identifiability for inferring spatial stochastic dynamics parameters from static snapshots, unlike distributed sources, with limits depending on modeling...

Reference graph

Works this paper leans on

78 extracted references · 78 canonical work pages · cited by 1 Pith paper · 1 internal anchor

  1. [1]

    Introduction to Econophysics: Correlations and Complexity in Finance

    Mantegna RN, Stanley HE. Introduction to Econophysics: Correlations and Complexity in Finance. Cambridge: Cambridge University Press; 1999. doi:10.1017/CBO9780511755767

  2. [2]

    Redner.A Guide to First-Passage Processes

    Redner S. A Guide to First-Passage Processes. Cambridge: Cambridge University Press; 2001. doi:10.1017/CBO9780511606014

  3. [3]

    Mathematical Biology I: An Introduction

    Murray JD. Mathematical Biology I: An Introduction. vol. 17 of Interdisciplinary Ap- plied Mathematics. 3rd ed. New York: Springer; 2002. doi:10.1007/b98868

  4. [4]

    Random Walks in Biology

    Berg HC. Random Walks in Biology. Expanded ed. Princeton University Press; 1983

  5. [5]

    URL:https://doi.org/10.1098/rsif.2008.0014 Dalesman S, Rundle SD, Coleman RA, Cotton PA

    Codling EA, Plank MJ, Benhamou S. Random walk models in biology. Journal of the Royal Society Interface. 2008;5:813-34. doi:10.1098/rsif.2008.0014

  6. [6]

    Random walk models in the life sciences: in- cluding births, deaths and local interactions

    Plank MJ, Simpson MJ, Baker RE. Random walk models in the life sciences: in- cluding births, deaths and local interactions. Journal of the Royal Society Interface. 2025;22(222):20240422. doi:10.1098/rsif.2024.0422

  7. [7]

    Diffusion and Ecological Problems: Modern Perspectives

    Okubo A, Levin SA. Diffusion and Ecological Problems: Modern Perspectives. 2nd ed. New York: Springer; 2001. doi:10.1007/978-1-4757-4978-6

  8. [8]

    Lattice population dynamics for plants with dispersing seeds and vegetative propagation

    Harada Y, Iwasa Y. Lattice population dynamics for plants with dispersing seeds and vegetative propagation. Researches on Population Ecology. 1994;36:237-49. doi:10.1007/BF02514940

  9. [9]

    A mechanistic simulation model of seed dispersal by animals

    Will H, Tackenberg O. A mechanistic simulation model of seed dispersal by animals. Journal of Ecology. 2008;96(5):1011-22. doi:10.1111/j.1365-2745.2007.01341.x

  10. [10]

    Mechanistic models of seed dispersal by animals

    Morales JM, Mor´ an L´ opez T. Mechanistic models of seed dispersal by animals. Oikos. 2022;2022(2):e08328. doi:10.1111/oik.08328. 36

  11. [11]

    Stochastic Modelling of Reaction–Diffusion Processes; 2020

    Erban R, Chapman SJ. Stochastic Modelling of Reaction–Diffusion Processes; 2020. doi:10.1017/9781108628389

  12. [12]

    Modeling and simulating chemical reactions

    Higham DJ. Modeling and simulating chemical reactions. SIAM Review. 2008;50(2):347-

  13. [13]

    doi:10.1137/060666457

  14. [14]

    Quan- tifying the roles of cell motility and cell proliferation in a circular barrier assay

    Simpson MJ, Treloar KK, Binder BJ, Haridas P, Manton KJ, Leavesley DI, et al. Quan- tifying the roles of cell motility and cell proliferation in a circular barrier assay. Journal of the Royal Society Interface. 2013;10(82):20130007. doi:10.1098/rsif.2013.0007

  15. [15]

    Multiple types of data are required to identify the mechanisms influencing the spatial ex- pansion of melanoma cell colonies

    Treloar KK, Simpson MJ, Haridas P, Manton KJ, Leavesley DI, McElwain DLS, et al. Multiple types of data are required to identify the mechanisms influencing the spatial ex- pansion of melanoma cell colonies. BMC Systems Biology. 2013;7:137. doi:10.1186/1752- 0509-7-137

  16. [16]

    A review of estimating animal abundance

    Seber GAF. A review of estimating animal abundance. Biometrics. 1986;42(2):267-92. doi:10.2307/2531049

  17. [17]

    Choice of size and number of quadrats to estimate density and fre- quency in Poisson and binomially dispersed populations

    Swindel BF. Choice of size and number of quadrats to estimate density and fre- quency in Poisson and binomially dispersed populations. Biometrics. 1983;39(2):455-64. doi:10.2307/2531018

  18. [18]

    Rapid behavioral matura- tion accelerates failure of stressed honey bee colonies

    Perry CJ, Søvik E, Myerscough MR, Barron AB. Rapid behavioral matura- tion accelerates failure of stressed honey bee colonies. Proceedings of the Na- tional Academy of Sciences of the United States of America. 2015;112(11):3427-32. doi:10.1073/pnas.1422089112

  19. [19]

    The pattern of neural crest advance in the cecum and colon

    Druckenbrod NR, Epstein ML. The pattern of neural crest advance in the cecum and colon. Developmental Biology. 2005;287(1):125-33. doi:10.1016/j.ydbio.2005.08.040

  20. [20]

    Behavior of enteric neural crest-derived cells varies with respect to the migratory wavefront

    Druckenbrod NR, Epstein ML. Behavior of enteric neural crest-derived cells varies with respect to the migratory wavefront. Developmental Dynamics. 2007;236(1):84-92. doi:10.1002/dvdy.20974

  21. [21]

    Design and interpretation of cell tra- jectory assays

    Bowden LG, Simpson MJ, Baker RE. Design and interpretation of cell tra- jectory assays. Journal of the Royal Society Interface. 2013;10(88):20130630. doi:10.1098/rsif.2013.0630. 37

  22. [22]

    Multi-scale modeling of a wound- healing cell migration assay

    Cai AQ, Landman KA, Hughes BD. Multi-scale modeling of a wound- healing cell migration assay. Journal of Theoretical Biology. 2007;245(3):576-94. doi:10.1016/j.jtbi.2006.10.024

  23. [23]

    Cell migration and proliferation during monolayer formation and wound healing

    Tremel A, Cai A, Tirtaatmadja N, Hughes BD, Stevens GW, Landman KA, et al. Cell migration and proliferation during monolayer formation and wound healing. Chemical Engineering Science. 2009;64:247-53. doi:10.1016/j.ces.2008.10.008

  24. [24]

    Migration of individual microvessel en- dothelial cells: stochastic model and parameter measurement

    Stokes CL, Lauffenburger DA, Williams SK. Migration of individual microvessel en- dothelial cells: stochastic model and parameter measurement. Journal of Cell Science. 1991;99(2):419-30. doi:10.1242/jcs.99.2.419

  25. [25]

    Analysis of the roles of microvessel endothelial cell random motility and chemotaxis in angiogenesis

    Stokes CL, Lauffenburger DA. Analysis of the roles of microvessel endothelial cell random motility and chemotaxis in angiogenesis. Journal of Theoretical Biology. 1991;152(3):377-403. doi:10.1016/S0022-5193(05)80201-2

  26. [26]

    GDNF is a chemoattractant for enteric neural cells

    Young HM, Hearn CJ, Farlie PG, Canty AJ, Thomas PQ, Newgreen DF. GDNF is a chemoattractant for enteric neural cells. Developmental Biology. 2001;229(2):503-16. doi:10.1006/dbio.2000.0100

  27. [27]

    Single particle tracking reveals spatial and dynamic organization of the Escherichia coli biofilm matrix

    Birjiniuk A, Billings N, Nance E, Hanes J, Ribbeck K, Doyle PS. Single particle tracking reveals spatial and dynamic organization of the Escherichia coli biofilm matrix. New Journal of Physics. 2014;16(8):085014. doi:10.1088/1367-2630/16/8/085014

  28. [28]

    Bio- physical aspects underlying the swarm to biofilm transition

    Worlitzer VM, Jose A, Grinberg I, B¨ ar M, Heidenreich S, Eldar A, et al. Bio- physical aspects underlying the swarm to biofilm transition. Science Advances. 2022;8(24):eabn8152. doi:10.1126/sciadv.abn8152

  29. [29]

    Flexible continuous-time modelling for heterogeneous animal movement

    Harris KJ, Blackwell PG. Flexible continuous-time modelling for heterogeneous animal movement. Ecological Modelling. 2013;255:29-37. doi:10.1016/j.ecolmodel.2013.01.020

  30. [30]

    URL: https://doi.org/10.1016/j.tree.2007.10.009 Preisser EL, Bolnick DI, Benard MF

    Patterson TA, Thomas L, Wilcox C, Ovaskainen O, Matthiopoulos J. State-space mod- els of individual animal movement. Trends in Ecology & Evolution. 2008;23:87-94. doi:10.1016/j.tree.2007.10.009

  31. [31]

    Tracking butterfly movements with harmonic radar reveals an effect of population age on movement distance

    Ovaskainen O, Smith AD, Osborne JL, Reynolds DR, Carreck NL, Martin AP, et al. Tracking butterfly movements with harmonic radar reveals an effect of population age on movement distance. Proceedings of the National Academy of Sciences of the United States of America. 2008;105(49):19090-5. doi:10.1073/pnas.0802066105. 38

  32. [32]

    Diffusion of indi- vidual birds in starling flocks

    Cavagna A, Duarte Queir´ os SM, Giardina I, Stefanini F, Viale M. Diffusion of indi- vidual birds in starling flocks. Proceedings of the Royal Society B: Biological Sciences. 2013;280(1756):20122484. doi:10.1098/rspb.2012.2484

  33. [33]

    Determination of parameter identifiability in nonlinear biophysical models: A Bayesian approach,

    Hines KE, Middendorf TR, Aldrich RW. Determination of parameter identifiability in nonlinear biophysical models: A Bayesian approach. Journal of General Physiology. 2014;143(4):401-16. doi:10.1085/jgp.201311116

  34. [34]

    2021 On structural and practical identifiability.Current Opinion in Systems Biology25, 60–69

    Wieland FG, Hauber AL, Rosenblatt M, T¨ onsing C, Timmer J. On structural and practical identifiability. Current Opinion in Systems Biology. 2021;25:60-9. doi:10.1016/j.coisb.2021.03.005

  35. [35]

    On structural and practical identifiability:

    Heinrich M, Rosenblatt M, Wieland FG, Stigter H, Timmer J. On structural and practical identifiability: Current status and update of results. Current Opinion in Systems Biology. 2025;41:100546. doi:10.1016/j.coisb.2025.100546

  36. [36]

    2026 Parameter Identifiability, Parameter Estimation, and Model Predic- tion for Differential Equation Models.SIAM REVIEW

    Simpson MJ, Baker RE. Parameter identifiability, parameter estimation and model prediction for differential equation models. SIAM Review. 2026;68:153-71. doi:10.1137/24M1667968

  37. [37]

    A Bayesian computational approach to explore the optimal duration of a cell proliferation assay

    Browning AP, McCue SW, Simpson MJ. A Bayesian computational approach to explore the optimal duration of a cell proliferation assay. Bulletin of Mathematical Biology. 2017;79:1888-906. doi:10.1007/s11538-017-0311-4

  38. [38]

    Bayesian inference of agent-based models: a tool for studying kidney branching morphogenesis

    Lambert B, MacLean AL, Fletcher AG, Coombes AN, Little MH, Byrne HM. Bayesian inference of agent-based models: a tool for studying kidney branching morphogenesis. Journal of Mathematical Biology. 2018;76:1673-97. doi:10.1007/s00285-018-1208-z

  39. [39]

    Inference and prediction for stochastic models of biological pop- ulations undergoing migration and proliferation

    Simpson MJ, Plank MJ. Inference and prediction for stochastic models of biological pop- ulations undergoing migration and proliferation. Journal of the Royal Society Interface. 2025;22(231):20250536. doi:10.1098/rsif.2025.0536

  40. [40]

    Multi-species simple exclusion pro- cesses

    Simpson MJ, Landman KA, Hughes BD. Multi-species simple exclusion pro- cesses. Physica A: Statistical Mechanics and its Applications. 2009;388(4):399-406. doi:10.1016/j.physa.2008.10.038

  41. [41]

    and Tildesley, Dominic J

    Pawitan Y. In All Likelihood: Statistical Modelling and Inference Using Likelihood. Oxford Science Publications; 2001. doi:10.1093/oso/9780198507659.001.0001. 39

  42. [42]

    Random dispersal in theoretical populations

    Skellam JG. Random dispersal in theoretical populations. Biometrika. 1951;38(1–2):196-

  43. [43]

    doi:10.1093/biomet/38.1-2.196

  44. [44]

    Mathematical Models in Biology

    Edelstein-Keshet L. Mathematical Models in Biology. vol. 46. Philadelphia, PA: Society for Industrial and Applied Mathematics; 2005

  45. [45]

    Elements of Mathematical Ecology

    Kot M. Elements of Mathematical Ecology. Cambridge: Cambridge University Press; 2001

  46. [46]

    Traveling waves in a coarse-grained model of volume-filling cell invasion: Simulations and comparisons

    Crossley RM, Maini PK, Lorenzi T, Baker RE. Traveling waves in a coarse-grained model of volume-filling cell invasion: Simulations and comparisons. Studies in Applied Mathematics. 2023;151(4):1471-97. doi:10.1111/sapm.12635

  47. [47]

    Phenotypic switch- ing mechanisms determine the structure of cell migration into extracellular ma- trix under the ‘go-or-grow’ hypothesis

    Crossley RM, Painter KJ, Lorenzi T, Maini PK, Baker RE. Phenotypic switch- ing mechanisms determine the structure of cell migration into extracellular ma- trix under the ‘go-or-grow’ hypothesis. Mathematical Biosciences. 2024;374:109240. doi:10.1016/j.mbs.2024.109240

  48. [48]

    Reconciling transport models across scales: The role of volume exclusion

    Taylor PR, Yates CA, Simpson MJ, Baker RE. Reconciling transport models across scales: The role of volume exclusion. Physical Review E. 2015;92(4):040701. doi:10.1103/PhysRevE.92.040701

  49. [49]

    Physics of transport and traffic phenom- ena in biology: From molecular motors and cells to organisms

    Chowdhury D, Schadschneider A, Nishinari K. Physics of transport and traffic phenom- ena in biology: From molecular motors and cells to organisms. Physics of Life Reviews. 2005;2:318-52. doi:10.1016/j.plrev.2005.09.001

  50. [50]

    A one-dimensional model of cell diffusion and aggregation, incorporating volume filling and cell-to-cell adhesion

    Anguige K, Schmeiser C. A one-dimensional model of cell diffusion and aggregation, incorporating volume filling and cell-to-cell adhesion. Journal of Mathematical Biology. 2009;58(3):395-427. doi:10.1007/s00285-008-0197-8

  51. [51]

    Excluded-volume effects in the diffusion of hard spheres

    Bruna M, Chapman SJ. Excluded-volume effects in the diffusion of hard spheres. Phys- ical Review E. 2012;85(1):011103. doi:10.1103/PhysRevE.85.011103

  52. [52]

    A stochastic model for wound healing

    Callaghan T, Khain E, Sander LM, Ziff RM. A stochastic model for wound healing. Journal of Statistical Physics. 2006;122(5):909-24. doi:10.1007/s10955-006-9022-1

  53. [53]

    Modeling tumor cell migra- tion: From microscopic to macroscopic models

    Deroulers C, Aubert M, Badoual M, Grammaticos B. Modeling tumor cell migra- tion: From microscopic to macroscopic models. Physical Review E. 2009;79(3):031917. doi:10.1103/PhysRevE.79.031917. 40

  54. [54]

    Multicellular computer simulation of morphogenesis: blastocoel roof thinning and matrix assembly in Xenopus laevis

    Longo D, Peirce SM, Skalak TC, Davidson L, Marsden M, Dzamba B, et al. Multicellular computer simulation of morphogenesis: blastocoel roof thinning and matrix assembly in Xenopus laevis. Developmental Biology. 2004;271(1):210-22. doi:10.1016/j.ydbio.2004.03.021

  55. [55]

    Rec- onciling diverse mammalian pigmentation patterns with a fundamental mathematical model

    Mort RL, Ross RJH, Hainey KJ, Harrison OJ, Keighren MA, Landini G, et al. Rec- onciling diverse mammalian pigmentation patterns with a fundamental mathematical model. Nature Communications. 2016;7:10288. doi:10.1038/ncomms10288

  56. [56]

    Volume-filling and quorum-sensing in models for chemosensitive movement

    Painter KJ, Hillen T. Volume-filling and quorum-sensing in models for chemosensitive movement. Canadian Applied Mathematics Quarterly. 2002;10(4):501-43

  57. [57]

    Modelling stripe formation in zebrafish: an agent- based approach

    Volkening A, Sandstede B. Modelling stripe formation in zebrafish: an agent- based approach. Journal of the Royal Society Interface. 2015;12(112):20150812. doi:10.1098/rsif.2015.0812

  58. [58]

    From individual to collective behavior in bacte- rial chemotaxis

    Erban R, Othmer HG. From individual to collective behavior in bacte- rial chemotaxis. SIAM Journal on Applied Mathematics. 2004;65(1):361-91. doi:10.1137/S003613990343241X

  59. [59]

    The diffusion limit of transport equations derived from velocity-jump processes

    Hillen T, Othmer HG. The diffusion limit of transport equations derived from velocity-jump processes. SIAM Journal on Applied Mathematics. 2000;61(3):751-75. doi:10.1137/S0036139999358167

  60. [60]

    Lattice and non-lattice models of tumour angiogenesis

    Plank MJ, Sleeman BD. Lattice and non-lattice models of tumour angiogenesis. Bulletin of Mathematical Biology. 2004;66(6):1785-819. doi:10.1016/j.bulm.2004.04.001

  61. [61]

    Random walks of swarming on monotonic resource distri- bution in a landscape

    Shi Z, Jiang D, Wang H. Random walks of swarming on monotonic resource distri- bution in a landscape. SIAM Journal on Applied Mathematics. 2025;85(3):1287-313. doi:10.1137/24M1708826

  62. [62]

    The derivation of chemotaxis equations as limit dynamics of moderately interacting stochastic many-particle systems

    Stevens A. The derivation of chemotaxis equations as limit dynamics of moderately interacting stochastic many-particle systems. SIAM Journal on Applied Mathematics. 2000;61:183-212. doi:10.1137/S0036139998342065

  63. [63]

    The role of cell-cell adhesion in wound healing

    Khain E, Sander LM, Schneider-Mizell CM. The role of cell-cell adhesion in wound healing. Journal of Statistical Physics. 2007;128:209-18. doi:10.1007/s10955-006-9194- 8. 41

  64. [64]

    Modelling count data with partial differ- ential equation models in biology

    Simpson MJ, Murphy RJ, Maclaren OJ. Modelling count data with partial differ- ential equation models in biology. Journal of Theoretical Biology. 2024;580:111732. doi:10.1016/j.jtbi.2024.111732

  65. [65]

    Correcting mean-field approximations for birth-death-movement processes

    Baker RE, Simpson MJ. Correcting mean-field approximations for birth-death-movement processes. Physical Review E. 2010;82(4):041905. doi:10.1103/PhysRevE.82.041905

  66. [66]

    Pair approximation for lattice models with multiple interaction scales

    Ellner SP. Pair approximation for lattice models with multiple interaction scales. Jour- nal of Theoretical Biology. 2001;210(4):435-47. doi:10.1006/jtbi.2001.2322

  67. [67]

    Continuum models describing probabilistic motion of tagged agents in exclusion processes

    Plank MJ, Simpson MJ. Continuum models describing probabilistic motion of tagged agents in exclusion processes. Physical Review E. 2026;113:014137. doi:10.1103/lzqy- n5mw

  68. [68]

    Statistical Inference

    Casella G, Berger R. Statistical Inference. 2nd ed.; 2024. doi:10.1201/9781003456285

  69. [69]

    Handbook of Mathematical Functions with Formu- las, Graphs, and Mathematical Tables

    Abramowitz M, Stegun IA, editors. Handbook of Mathematical Functions with Formu- las, Graphs, and Mathematical Tables. vol. 55 of National Bureau of Standards Applied Mathematics Series; 1964

  70. [70]

    The Generalization of Student’s Ratio , year =

    Wilks SS. The large-sample distribution of the likelihood ratio for testing composite hypotheses. The Annals of Mathematical Statistics. 1938;9(1):60-2. doi:10.1214/aoms/1177732360

  71. [71]

    Profile likelihood for estimation and confidence intervals

    Royston P. Profile likelihood for estimation and confidence intervals. The Stata Journal. 2007;7(3):376-87. doi:10.1177/1536867X0700700305

  72. [72]

    Making predictions using poorly identified mathematical models

    Simpson MJ, Maclaren OJ. Making predictions using poorly identified mathematical models. Bulletin of Mathematical Biology. 2024;86(7):80. doi:10.1007/s11538-024-01294- 0

  73. [73]

    Incorporating Spatial Diffusion into Models of Bursty Stochastic Transcription

    Miles CE. Incorporating spatial diffusion into models of bursty stochastic transcription. Journal of the Royal Society Interface. 2025;22(225):20240739. doi:10.1098/rsif.2024.0739

  74. [74]

    Mathematical Biosciences , volume =

    Simpson MJ, Walker SA, Studerus EN, McCue SW, Murphy RJ, Maclaren OJ. Pro- file likelihood-based parameter and predictive interval analysis guides model choice 42 for ecological population dynamics. Mathematical Biosciences. 2023;355:108950. doi:10.1016/j.mbs.2022.108950

  75. [75]

    HTTP Mailbox - Asynchronous RESTful Communication

    Vardeman SB. What about the other intervals? The American Statistician. 1992;46(3):193-7. doi:10.1080/00031305.1992.10475882

  76. [76]

    Profile-Wise Analysis: A profile likelihood-based workflow for identifiability analysis, estimation, and prediction with mechanis- tic mathematical models

    Simpson MJ, Maclaren OJ. Profile-Wise Analysis: A profile likelihood-based workflow for identifiability analysis, estimation, and prediction with mechanis- tic mathematical models. PLOS Computational Biology. 2023;19(9):e1011515. doi:10.1371/journal.pcbi.1011515

  77. [77]

    Likelihood-based inference, identifiability, and pre- diction using count data from lattice-based random walk models

    Liu Y, Warne DJ, Simpson MJ. Likelihood-based inference, identifiability, and pre- diction using count data from lattice-based random walk models. Physical Review E. 2024;110(4):044405. doi:10.1103/PhysRevE.110.044405

  78. [78]

    DifferentialEquations.jl—A Performant and Feature-Rich Ecosystem for Solving Differential Equations in Julia,

    Rackauckas C, Nie Q. DifferentialEquations.jl: A performant and feature-rich ecosys- tem for solving differential equations in Julia. Journal of Open Research Software. 2017;5(1):15. doi:10.5334/jors.151. 43