Paper List
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SSDLabeler: Realistic semi-synthetic data generation for multi-label artifact classification in EEG
This paper addresses the core challenge of training robust multi-label EEG artifact classifiers by overcoming the scarcity and limited diversity of ma...
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Decoding Selective Auditory Attention to Musical Elements in Ecologically Valid Music Listening
This paper addresses the core challenge of objectively quantifying listeners' selective attention to specific musical components (e.g., vocals, drums,...
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Physics-Guided Surrogate Modeling for Machine Learning–Driven DLD Design Optimization
This paper addresses the core bottleneck of translating microfluidic DLD devices from research prototypes to clinical applications by replacing weeks-...
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Mechanistic Interpretability of Antibody Language Models Using SAEs
This work addresses the core challenge of achieving both interpretability and controllable generation in domain-specific protein language models, spec...
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The Effective Reproduction Number in the Kermack-McKendrick model with age of infection and reinfection
This paper addresses the challenge of accurately estimating the time-varying effective reproduction number ℛ(t) in epidemics by incorporating two crit...
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Fluctuating Environments Favor Extreme Dormancy Strategies and Penalize Intermediate Ones
This paper addresses the core challenge of determining how organisms should tune dormancy duration to match the temporal autocorrelation of their envi...
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Covering Relations in the Poset of Combinatorial Neural Codes
This work addresses the core challenge of navigating the complex poset structure of neural codes to systematically test the conjecture linking convex ...
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Revealing stimulus-dependent dynamics through statistical complexity
This paper addresses the core challenge of detecting stimulus-specific patterns in neural population dynamics that remain hidden to traditional variab...
Exactly Solvable Population Model with Square-Root Growth Noise and Cell-Size Regulation
Institute for Theoretical Physics, Department of Physics, Utrecht University, Utrecht, Netherlands | Centre for Complex Systems Studies, Utrecht University, Utrecht, Netherlands
The 30-Second View
IN SHORT: This paper addresses the fundamental gap in understanding how microscopic growth fluctuations, specifically those with size-dependent (square-root) noise, shape population-level fitness and statistics in cell populations, providing an exactly solvable model that contrasts sharply with existing size-independent noise models.
Innovation (TL;DR)
- Theory Demonstrates that the asymptotic population growth rate Λ is exactly equal to the mean single-cell growth rate k, independent of noise strength σ and division mechanisms, establishing square-root growth noise as neutral for long-term fitness.
- Methodology Derives exact, closed-form expressions for the steady-state snapshot cell-size distribution, showing it results from a universal one-sided exponential convolution of the deterministic inverse-square-law solution, with kernel width σ².
- Theory Proves that the mean-rescaled population size Nt/⟨Nt⟩ converges to a stationary compound Poisson–exponential distribution determined solely by the growth noise parameter σ, independent of division or partitioning noise.
Key conclusions
- Population growth rate Λ = k exactly, demonstrating fitness neutrality of square-root noise (contrasting with models where Λ increases with variance of size-independent noise).
- Steady-state population mean cell size shifts by -σ² (e.g., ⟨s⟩pop = 2ln2 - σ² + O(e^{-1/σ²})), while variance is modified only at order σ⁴, showing a hierarchy of decoupling.
- The coefficient of variation of total cell number saturates to √(2σ²), and the full distribution of the mean-rescaled population size is a compound Poisson–exponential, providing concrete, testable signatures.
Abstract: We analyze a size-structured branching process in which individual cells grow exponentially according to a Feller square-root process and divide under general size-control mechanisms. We obtain exact expressions for the asymptotic population growth rate, the steady-state snapshot distribution of cell sizes, and the fluctuations of the total cell number. Our first result is that the population growth rate is exactly equal to the mean single-cell growth rate, for all noise strengths and for all division and size-regulation schemes that maintain size homeostasis. Thus square-root growth noise is neutral with respect to long-term fitness, in sharp contrast to models with size-independent stochastic growth rates. Second, we show that the steady-state population cell-size distribution is obtained from the deterministic inverse-square-law solution by a one-sided exponential convolution with kernel width set by the strength of growth fluctuations. Third, the mean-rescaled population size Nt/⟨Nt⟩ converges to a stationary compound Poisson–exponential distribution that depends only on growth noise. This distribution, and hence the long-time shape of population-size fluctuations, is unchanged by division-size noise or asymmetric partitioning. These results identify Feller-type exponential growth with square-root noise as an exactly solvable benchmark for stochastic growth in size-controlled populations and provide concrete signatures that distinguish it from models with size-independent growth-rate noise.