…where we talk: time at Los Alamos, modeling TB, and tips for international flights.

Dr. Kirschner was the first mathematics professor appointed in a medical school. She researches immune responses to infections using multiscale modeling. She served as Editor-in-Chief of the Journal of Theoretical Biology for 20 years and as president of SMB.

Learn more about Denise’s work on her website: http://malthus.micro.med.umich.edu

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• Twitter: @smb_mathbiology 
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• The Bulletin of Mathematical Biology

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The Society is accepting nominations for the 2027 Society Prize Award cycle. Society members are encouraged to nominate candidates by submitting the required materials in PDF format via the Prize submission form. Contact SMB Secretary Brandilyn Stigler (secretary@smb.org) if you have any questions.

By Monday, 14 September 2026, the nominator must submit:

• Contact information for the nominators and nominee, including SMB Members IDs for both nominator and nominee
• A letter (no more than 4 pages) describing the nominee's qualifications and commenting on the nominee's scientific contributions for the society award.
• The nominee's curriculum vitae, including all publications.
• Two supporting letter

Submit Your Prize Nomination

Nominees may be affiliated with non-academic institutions, however, please note that Society membership is a requirement for the nominator and nominee. All applications must be complete and submitted by Monday, 23:59PM ET, 14 September 2026 in order to be considered.

Refining niche metric calculations: A modified weighting approach to Colwell and Futuyma’s method

by Kürşad Özkan, Serkan Özdemir, Bart Muys, Salih Doğan

This study resolves long-standing limitations of the Colwell & Futuyma (1971) method for calculating niche breadth and niche overlap. The original weighting factors collapse to zero when resource states are empty or uniformly used, making niche calculations undefined. We introduce modified weighting factors based on exponential transformations that always yield positive values, ensuring valid niche metric computation under any resource matrix structure. Testing with eight hypothetical matrices and an empirical mite community dataset demonstrated that the edj factor consistently produces ecologically meaningful results, correctly ranking specialists and generalists and resolving previously undefined niche overlap.

Image Description: This study introduces modified weighting factors based on exponential transformations to resolve the mathematical limitations of classical niche metrics (Colwell & Futuyma 1971; Hanski 1978). The classical weighting factors collapse to zero under certain resource matrix configurations, rendering niche breadth and overlap calculations undefined. The proposed modification ensures strictly positive weights while preserving the unit-sum constraint and full compatibility with the original framework. Validation across eight hypothetical matrices and an empirical dataset of 18 Raphignathoid mite species across six habitats in Türkiye demonstrates that the modified relative factor consistently produces ecologically coherent niche metrics, correctly ranking specialists and generalists and resolving previously undefined niche overlap estimates.

Ensemble Optimal Control for Managing Drug Resistance in Cancer Therapies

by Alessandro Scagliotti; Federico Scagliotti; Laura Deborah Locati; Federico Sottotetti

Cancer treatment often relies on the highest dose a patient can tolerate, but this may not be the best way to control tumors over time. This study uses mathematical modeling to explore a different approach: managing the balance between drug-sensitive and drug-resistant cancer cells. By simulating prostate cancer treated with androgen deprivation therapy, the authors show how treatment timing could be adapted rather than kept continuously high. The proposed “Off-On” adaptive therapy starts with observation and introduces treatment only when needed, aiming to keep the disease under long-term control. The work suggests that smarter schedules, not simply more drug, may improve chronic cancer management.

Image Description: Left: Ensemble optimal control approach. Center: On-Off Adaptive Therapy. Right: Off-On Adaptive Therapy.

Revisiting Turing's Chemical Basis of Morphogenesis

by John J. Tyson

Although Alan Turing’s 1952 paper on the chemical basis of morphogenesis is a classic of theoretical biology, it is notoriously difficult to read. His chemical examples are unusual, his linear stability analysis of the homogeneous steady state seems unnecessarily complex, and his numerical simulations are mysterious. To make Turing’s paper more accessible, I pose his reaction-diffusion equations in dimensionless form, place his linear stability analysis in the context of later approaches, revise his models in more chemically realistic terms, and provide help for computing Turing patterns in one- or two spatial dimensions. I also discuss how Turing’s stationary patterns relate to traveling waves in reaction-diffusion equations.

Does Timing Matter? Exploring the Effects of Measurement Error on Models

by Brock D. Sherlock; Marko A.A. Boon; Maria Vlasiou; Adelle C.F. Coster

Measurement error is inevitable in experimental data collection. Mathematical biologists typically account for dependent variable errors, while independent variable errors are less commonly considered. This work investigates how independent-variable measurement error affects parameter inference in biological systems and reviews statistical methods to address it. We find that parameter inference is often robust to measurement errors, even without explicitly accounting for them. However, some systems are susceptible to these errors, leading to biased parameter estimates. We evaluate correction methods, focusing on their assumptions and data requirements, to guide researchers in selecting appropriate approaches for their specific contexts.

Image Description: Illustration of the effects of measurement error in the independent variable. An oscillating model, the amplitude is estimated from synthetic data. The experimental protocol prescribes independent variable values for data collection. These designated times align with the peaks and troughs of the oscillation. However, the independent variable is subject to error and the true values at which measurements are taken are distributed about the prescribed values. When the true independent variable values are recorded (top) naïve parameter estimation can recover the amplitude that generated the data. However, when only the protocol prescribed values are recorded, as opposed to the true independent variable value at measurement, (bottom) naive parameter estimation leads to a biased estimate.

Damage-Driven Irreversibility and Emergent Senescence in Age–Structured Cell Populations

by Koffi Enakoutsa

A transient stress episode is sufficient to cause a lasting increase in the senescent cell fraction — even after the stressor is completely removed.

Article Summary and Graphical Abstract

A Hallmark-Integrated, Agent-Based Framework for Intratumor Heterogeneity in Melanoma Evolution

by Khola Jamshad, Trachette L. Jackson

We introduce a computational model that uses biologically informed cell behaviors to simulate how genetic diversity within a single tumor shapes its growth and structure over time. The model accounts for mutation-specific advantages, and interactions between tumor and immune cells. Focusing on melanoma, we find that simulated tumors can develop three distinct levels of heterogeneity, influenced by how frequently new mutations arise and by the tumor’s ability to attract immune cells. We also show that tumor cell movement is necessary to reproduce the complex tumor shapes observed in patients. Together, these findings provide a framework for building patient-specific tumor models that connect genetic information to tumor behavior.

A scheme for the BEP-HIM agent-based model for tumor evolution with key findings for melanoma.

Mono- and Polyauxic Growth Kinetics: A Semi-Mechanistic Framework for Complex Biological Dyanmics

by Gustavo Mockaitis

Understanding how microbes grow in complex mixtures, like those in bioenergy and waste valorization, is tricky. Current math models are either too basic or demand impractical amounts of data. This study introduces a smart, open-source tool that bridges the gap. It breaks down messy, multi-phase growth curves into clear, overlapping steps. By using automated algorithms to filter bad data and find the best fit, it pulls real biological insights, such as true growth rates and delay times, straight from standard, easy-to-collect observations. It’s a reliable way to turn everyday reactor data into deep, actionable understanding.

Unified semi-mechanistic framework for polyauxic microbial growth analysis. Experimental biomass-versus-time data, illustrated with a chemostat context, are processed through a modeling pipeline that reformulates canonical sigmoidal equations, estimates parameters by global and local optimization, and performs model selection. The output is an overall fitted curve decomposed into individual growth phases, yielding interpretable phase-specific kinetic parameters such as maximum growth rate and lag time.

Emergence of Bursting and Delay-Induced Spiral Patterns in Eco-Epidemiological Systems

by Namrata Mani Tripathi

Understanding the spatio-temporal dynamics of interacting populations is crucial for ecological systems. We develop an eco-epidemic model with susceptible and infected prey and predators, incorporating carryover $(f_1)$, fear $(f_2)$, and recovery $(\gamma)$. Existence, boundedness, and Hopf bifurcation are established. Without delays, $f_1$ stabilizes while $f_2$ destabilizes dynamics, and recovery affects populations. With delays, chaotic oscillations and bursting arise in unstable regimes, while sufficient recovery suppresses delay effects. Spatial analysis shows Turing patterns, where delays and recovery shape spirals and clusters, influencing ecosystem stability.

Delay-driven eco-epidemic dynamics illustrating how fear, carryover, and recovery generate chaotic oscillations and spiral pattern formation in space.