Termite mounds are known for their ability to maintain self-sustained ventilation and thermoregulation irrespective of external climatic conditions. Although there has been extensive interest in this topic, especially for designing energy-efficient buildings, it is still not fully understood how mound properties are controlled. This article reviews established knowledge and identifies gaps in the study of climate control within termite mounds, proposing an interdisciplinary approach that combines X-ray tomography and flow field simulations. Through specific examples, we demonstrate how these methods can deepen our understanding of termite mound structure and its climate-regulating functions.
{"title":"Termite mound architecture and climate control: a review of X-ray tomography and flow field simulation approaches.","authors":"Nengi Fiona Karibi-Botoye, Guy Theraulaz, Bagus Muljadi, Vasily Demyanov, Kamaljit Singh","doi":"10.1098/rsif.2025.0263","DOIUrl":"10.1098/rsif.2025.0263","url":null,"abstract":"<p><p>Termite mounds are known for their ability to maintain self-sustained ventilation and thermoregulation irrespective of external climatic conditions. Although there has been extensive interest in this topic, especially for designing energy-efficient buildings, it is still not fully understood how mound properties are controlled. This article reviews established knowledge and identifies gaps in the study of climate control within termite mounds, proposing an interdisciplinary approach that combines X-ray tomography and flow field simulations. Through specific examples, we demonstrate how these methods can deepen our understanding of termite mound structure and its climate-regulating functions.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20250263"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12539963/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145346050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Integrating factors affecting the success of invasive insect pests into dynamical models can help assessing their invasion risks and control. Here, we model the spread of a gall-forming hymenopteran parasite of chestnut trees, Dryocosmus kuriphilus, and its control agent, Torymus sinensis, across 23 natural forest sites located in the French Eastern Pyrenees. The integration of field estimates of the levels of bottom-up (frequency, density and genetic susceptibility of chestnut trees) and top-down (hyperparasitism by native insects and fungi) control of the pest in a Nicholson-Bailey model allowed to identify source and sink sites for the invasive species and its control agent. Comparisons with the observed levels of hyperparasitism by T. sinensis showed that it was found in 7/23 sink sites. The extension of our modelling into a two-site model showed that dispersal rates as low as 1‰ can be responsible for the persistence of T. sinensis in sinks, regardless of the precise dynamical regime of D. kuriphilus-T. sinensis coexistence in the source. Although dispersal promotes the persistence of the control agent and tends to homogenize its effectiveness in both sites, it was also shown to reduce the global biological control effectiveness at high rates of coupling.
{"title":"Source-sink dynamics explains the coexistence of the invasive pest <i>Dryocosmus kuriphilus</i> and its biological control agent <i>Torymus sinensis</i> across French Eastern Pyrenees.","authors":"Jean-Loup Zitoun, Raphaël Rousseau, Sébastien Gourbière","doi":"10.1098/rsif.2025.0283","DOIUrl":"10.1098/rsif.2025.0283","url":null,"abstract":"<p><p>Integrating factors affecting the success of invasive insect pests into dynamical models can help assessing their invasion risks and control. Here, we model the spread of a gall-forming hymenopteran parasite of chestnut trees, <i>Dryocosmus kuriphilus</i>, and its control agent, <i>Torymus sinensis</i>, across 23 natural forest sites located in the French Eastern Pyrenees. The integration of field estimates of the levels of bottom-up (frequency, density and genetic susceptibility of chestnut trees) and top-down (hyperparasitism by native insects and fungi) control of the pest in a Nicholson-Bailey model allowed to identify source and sink sites for the invasive species and its control agent. Comparisons with the observed levels of hyperparasitism by <i>T. sinensis</i> showed that it was found in 7/23 sink sites. The extension of our modelling into a two-site model showed that dispersal rates as low as 1‰ can be responsible for the persistence of <i>T. sinensis</i> in sinks, regardless of the precise dynamical regime of <i>D. kuriphilus</i>-<i>T. sinensis</i> coexistence in the source. Although dispersal promotes the persistence of the control agent and tends to homogenize its effectiveness in both sites, it was also shown to reduce the global biological control effectiveness at high rates of coupling.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20250283"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12539961/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145346137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-10-08DOI: 10.1098/rsif.2024.0916
Kamal Dingle, Pascal Hagolani, Roland Zimm, Muhammad Umar, Samantha O'Sullivan, Ard Louis
By linking genetic sequences to phenotypic traits, genotype-phenotype maps represent a key layer in biological organization. Their structure modulates the effects of genetic mutations which can contribute to shaping evolutionary outcomes. Recent work based on algorithmic information theory introduced an upper bound on the likelihood of a random genetic mutation causing a transition between two phenotypes, using only the conditional complexity between them. Here we evaluate how well this bound works for a range of genotype-phenotype maps, including a differential equation model for circadian rhythm, a matrix-multiplication model of gene regulatory networks, a developmental model of tooth morphologies for ringed seals, a polyomino-tile shape model of biological self-assembly, and the hydrophobic/polar (HP) lattice protein model. By assessing three levels of predictive performance, we find that the bound provides meaningful estimates of phenotype transition probabilities across these complex systems. These results suggest that transition probabilities can be predicted to some degree directly from the phenotypes themselves, without needing detailed knowledge of the underlying genotype-phenotype map.
{"title":"Bounding phenotype transition probabilities via conditional complexity.","authors":"Kamal Dingle, Pascal Hagolani, Roland Zimm, Muhammad Umar, Samantha O'Sullivan, Ard Louis","doi":"10.1098/rsif.2024.0916","DOIUrl":"10.1098/rsif.2024.0916","url":null,"abstract":"<p><p>By linking genetic sequences to phenotypic traits, genotype-phenotype maps represent a key layer in biological organization. Their structure modulates the effects of genetic mutations which can contribute to shaping evolutionary outcomes. Recent work based on algorithmic information theory introduced an upper bound on the likelihood of a random genetic mutation causing a transition between two phenotypes, using only the conditional complexity between them. Here we evaluate how well this bound works for a range of genotype-phenotype maps, including a differential equation model for circadian rhythm, a matrix-multiplication model of gene regulatory networks, a developmental model of tooth morphologies for ringed seals, a polyomino-tile shape model of biological self-assembly, and the hydrophobic/polar (HP) lattice protein model. By assessing three levels of predictive performance, we find that the bound provides meaningful estimates of phenotype transition probabilities across these complex systems. These results suggest that transition probabilities can be predicted to some degree directly from the phenotypes themselves, without needing detailed knowledge of the underlying genotype-phenotype map.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20240916"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12503940/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-10-22DOI: 10.1098/rsif.2025.0528
Jordi Pla-Mauri, Ricard Solé
Living systems have evolved cognitive complexity to reduce environmental uncertainty, enabling them to predict and prepare for future conditions. Anticipation, distinct from simple prediction, involves active adaptation before an event occurs and is a key feature of both neural and aneural biological agents. Building on the moving average convergence-divergence principle from financial trend analysis, we propose an implementation of anticipation through synthetic biology by designing and evaluating experimentally testable minimal genetic circuits capable of anticipating environmental trends. Through deterministic and stochastic analyses, we demonstrate that these motifs achieve robust anticipatory responses under a wide range of conditions. Our findings suggest that simple genetic circuits could be naturally exploited by cells to prepare for future events, providing a foundation for engineering predictive biological systems.
{"title":"A minimal genetic circuit for cellular anticipation.","authors":"Jordi Pla-Mauri, Ricard Solé","doi":"10.1098/rsif.2025.0528","DOIUrl":"10.1098/rsif.2025.0528","url":null,"abstract":"<p><p>Living systems have evolved cognitive complexity to reduce environmental uncertainty, enabling them to predict and prepare for future conditions. Anticipation, distinct from simple prediction, involves active adaptation before an event occurs and is a key feature of both neural and aneural biological agents. Building on the moving average convergence-divergence principle from financial trend analysis, we propose an implementation of anticipation through synthetic biology by designing and evaluating experimentally testable minimal genetic circuits capable of anticipating environmental trends. Through deterministic and stochastic analyses, we demonstrate that these motifs achieve robust anticipatory responses under a wide range of conditions. Our findings suggest that simple genetic circuits could be naturally exploited by cells to prepare for future events, providing a foundation for engineering predictive biological systems.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20250528"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12539953/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145346075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael Pan, Fatemeh Malekipour, Peter Pivonka, Ashleigh V Morrice-West, Jennifer A Flegg, R Chris Whitton, Peta L Hitchens
Fractures of the distal limb in Thoroughbred racehorses primarily occur because of accumulation of bone microdamage from high-intensity training. Mathematical models of subchondral bone adaptation of the third metacarpal lateral condyles are capable of approximating existing data for Thoroughbred racehorses in training or at rest. To improve upon previous models, we added a dynamic resorption rate and microdamage accumulation and repair processes. Our ordinary differential equation model simulates the coupled processes of bone adaptation and microdamage accumulation, and is calibrated to data on racehorses in training and rest. Sensitivity analyses of our model suggest that joint loads and distances covered per day are among the most significant parameters for predicting microdamage accumulated during training. We also use the model to compare the impact of incrementally increasing training programmes as horses enter training from a period of rest, and maintenance workloads of horses that are race fit on bone adaptation. We find that high-speed training accounts for the majority of damage to the bone. Furthermore, for horses in race training, the estimated rates of bone repair are unable to offset the rate of damage accumulation under a typical Australian racing campaign, highlighting the need for regular rest from training.
{"title":"A mathematical model of metacarpal subchondral bone adaptation, microdamage and repair in racehorses.","authors":"Michael Pan, Fatemeh Malekipour, Peter Pivonka, Ashleigh V Morrice-West, Jennifer A Flegg, R Chris Whitton, Peta L Hitchens","doi":"10.1098/rsif.2025.0297","DOIUrl":"10.1098/rsif.2025.0297","url":null,"abstract":"<p><p>Fractures of the distal limb in Thoroughbred racehorses primarily occur because of accumulation of bone microdamage from high-intensity training. Mathematical models of subchondral bone adaptation of the third metacarpal lateral condyles are capable of approximating existing data for Thoroughbred racehorses in training or at rest. To improve upon previous models, we added a dynamic resorption rate and microdamage accumulation and repair processes. Our ordinary differential equation model simulates the coupled processes of bone adaptation and microdamage accumulation, and is calibrated to data on racehorses in training and rest. Sensitivity analyses of our model suggest that joint loads and distances covered per day are among the most significant parameters for predicting microdamage accumulated during training. We also use the model to compare the impact of incrementally increasing training programmes as horses enter training from a period of rest, and maintenance workloads of horses that are race fit on bone adaptation. We find that high-speed training accounts for the majority of damage to the bone. Furthermore, for horses in race training, the estimated rates of bone repair are unable to offset the rate of damage accumulation under a typical Australian racing campaign, highlighting the need for regular rest from training.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20250297"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12483640/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-10-15DOI: 10.1098/rsif.2025.0462
Stephen Maren
The Beckman Institute for Advanced Science of Technology at the University of Illinois Urbana-Champaign was established in 1989 with the generous support of the Arnold and Mabel Beckman Foundation. It was built to break through disciplinary boundaries and produce scientific discoveries that could only be made by teams using interdisciplinary approaches. After 36 years, I reflect on the transformative legacy of the Beckman Institute at Illinois and how it informs my perspective on future of interdisciplinary research.
{"title":"The Beckman legacy and the future of interdisciplinary research.","authors":"Stephen Maren","doi":"10.1098/rsif.2025.0462","DOIUrl":"10.1098/rsif.2025.0462","url":null,"abstract":"<p><p>The Beckman Institute for Advanced Science of Technology at the University of Illinois Urbana-Champaign was established in 1989 with the generous support of the Arnold and Mabel Beckman Foundation. It was built to break through disciplinary boundaries and produce scientific discoveries that could only be made by teams using interdisciplinary approaches. After 36 years, I reflect on the transformative legacy of the Beckman Institute at Illinois and how it informs my perspective on future of interdisciplinary research.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20250462"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12520765/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145292688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-10-08DOI: 10.1098/rsif.2025.0183
Mario Castro, Rafael Vida, Javier Galeano, Jose A Cuesta
Metagenomic data has significantly advanced microbiome research by employing ecological models, particularly in personalized medicine. The generalized Lotka-Volterra (gLV) model is commonly used to understand microbial interactions and predict ecosystem dynamics. However, gLV models often fail to capture complex interactions, especially when data are limited or noisy. This study critically assesses the effectiveness of gLV and similar models using Bayesian inference and a model reduction method based on information theory. We found that ecological data often leads to non-interpretability and overfitting due to limited information, noisy data and parameter sloppiness. Our results highlight the need for simpler models that align with the available data and propose a distribution-based approach to better capture ecosystem diversity, stability and competition. These findings challenge current bottom-up ecological modelling practices and aim to shift the focus towards a statistical mechanics view of ecology based on distributions of parameters.
{"title":"Scarce data, noisy inferences and overfitting: the hidden flaws in ecological dynamics modelling.","authors":"Mario Castro, Rafael Vida, Javier Galeano, Jose A Cuesta","doi":"10.1098/rsif.2025.0183","DOIUrl":"10.1098/rsif.2025.0183","url":null,"abstract":"<p><p>Metagenomic data has significantly advanced microbiome research by employing ecological models, particularly in personalized medicine. The generalized Lotka-Volterra (gLV) model is commonly used to understand microbial interactions and predict ecosystem dynamics. However, gLV models often fail to capture complex interactions, especially when data are limited or noisy. This study critically assesses the effectiveness of gLV and similar models using Bayesian inference and a model reduction method based on information theory. We found that ecological data often leads to non-interpretability and overfitting due to limited information, noisy data and parameter sloppiness. Our results highlight the need for simpler models that align with the available data and propose a distribution-based approach to better capture ecosystem diversity, stability and competition. These findings challenge current bottom-up ecological modelling practices and aim to shift the focus towards a statistical mechanics view of ecology based on distributions of parameters.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20250183"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12505159/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-10-15DOI: 10.1098/rsif.2025.0510
Korin Reznikov, Valery Melnikov, Nir Sapir
Radar technology has become a powerful tool for studying animal aeroecology in the lower atmosphere, particularly bird migration across large spatio-temporal scales. Quantifying bird density from radar data requires radar cross-section (RCS) estimates. Although RCS data exist for small bird species, large birds, especially soaring and flocking species, remain poorly characterized, partly due to technical challenges in measuring and modelling their complex morphology. This study introduces a practical and accessible modelling framework for estimating species-specific RCS in large birds, using the T-matrix electromagnetic scattering method, based on geometrically simplified representations of bird morphology. We computed spherical RCS values for 11 large bird species across C- and S-band radar wavelengths and compared them with both spherical and prolate spheroidal RCS estimates obtained using the WIPL-D software, a method previously validated for biological targets. As expected, the spherical simplification led to a systematic overestimation of RCS relative to a more anatomically representative model. However, the bias was consistent and can be corrected using regression-derived scaling factors. This approach addresses the critical lack of empirical RCS data for large birds, offering an alternative that can be implemented in open-source platforms. It can be integrated with automated detection tools to enhance our understanding of migration patterns in understudied bird groups and to support efforts to mitigate bird-aircraft collisions.
{"title":"Estimating large birds' radar cross-section for aeroecology studies using T-matrix modelling.","authors":"Korin Reznikov, Valery Melnikov, Nir Sapir","doi":"10.1098/rsif.2025.0510","DOIUrl":"10.1098/rsif.2025.0510","url":null,"abstract":"<p><p>Radar technology has become a powerful tool for studying animal aeroecology in the lower atmosphere, particularly bird migration across large spatio-temporal scales. Quantifying bird density from radar data requires radar cross-section (RCS) estimates. Although RCS data exist for small bird species, large birds, especially soaring and flocking species, remain poorly characterized, partly due to technical challenges in measuring and modelling their complex morphology. This study introduces a practical and accessible modelling framework for estimating species-specific RCS in large birds, using the T-matrix electromagnetic scattering method, based on geometrically simplified representations of bird morphology. We computed spherical RCS values for 11 large bird species across C- and S-band radar wavelengths and compared them with both spherical and prolate spheroidal RCS estimates obtained using the WIPL-D software, a method previously validated for biological targets. As expected, the spherical simplification led to a systematic overestimation of RCS relative to a more anatomically representative model. However, the bias was consistent and can be corrected using regression-derived scaling factors. This approach addresses the critical lack of empirical RCS data for large birds, offering an alternative that can be implemented in open-source platforms. It can be integrated with automated detection tools to enhance our understanding of migration patterns in understudied bird groups and to support efforts to mitigate bird-aircraft collisions.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20250510"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12520780/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145292686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-10-22DOI: 10.1098/rsif.2025.0338
Aliza Ehrman, Thomas Kriecherbauer, Lars Grüne, Michael Margaliot
The ribosome flow model (RFM) is a phenomenological model for the unidirectional flow of particles along a one-dimensional chain of [Formula: see text] sites. The RFM has been extensively used to study the dynamics of ribosome flow along a single-mRNA molecule during translation. In this case, the particles model ribosomes and each site corresponds to a consecutive group of codons. Networks of interconnected RFMs have been used to model and analyse large-scale translation in the cell and, in particular, the effects of competition for shared resources. Here, we analyse the RFM with a negative feedback connection from the protein production rate to the initiation rate. This model is based on, for example, the production of proteins that inhibit the translation of their own mRNA. The RFM with negative feedback is a 2-cooperative dynamic system, i.e. its flow maps the set of vectors with up to one-sign variation to itself. Using tools from the theory of 2-cooperative dynamical systems, we provide a simple condition guaranteeing that the closed-loop system admits at least one non-trivial periodic solution. When this condition holds, we also explicitly characterize a large set of initial conditions such that any solution emanating from this set converges to a non-trivial periodic solution. Such a solution corresponds to a periodic pattern of ribosome densities along the mRNA and to a periodic pattern of protein production.
{"title":"Negative feedback and oscillations in a model for mRNA translation.","authors":"Aliza Ehrman, Thomas Kriecherbauer, Lars Grüne, Michael Margaliot","doi":"10.1098/rsif.2025.0338","DOIUrl":"10.1098/rsif.2025.0338","url":null,"abstract":"<p><p>The ribosome flow model (RFM) is a phenomenological model for the unidirectional flow of particles along a one-dimensional chain of [Formula: see text] sites. The RFM has been extensively used to study the dynamics of ribosome flow along a single-mRNA molecule during translation. In this case, the particles model ribosomes and each site corresponds to a consecutive group of codons. Networks of interconnected RFMs have been used to model and analyse large-scale translation in the cell and, in particular, the effects of competition for shared resources. Here, we analyse the RFM with a negative feedback connection from the protein production rate to the initiation rate. This model is based on, for example, the production of proteins that inhibit the translation of their own mRNA. The RFM with negative feedback is a 2-cooperative dynamic system, i.e. its flow maps the set of vectors with up to one-sign variation to itself. Using tools from the theory of 2-cooperative dynamical systems, we provide a simple condition guaranteeing that the closed-loop system admits at least one non-trivial periodic solution. When this condition holds, we also explicitly characterize a large set of initial conditions such that any solution emanating from this set converges to a non-trivial periodic solution. Such a solution corresponds to a periodic pattern of ribosome densities along the mRNA and to a periodic pattern of protein production.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20250338"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12539956/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145346099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-10-15DOI: 10.1098/rsif.2025.0276
Yuanhang Zhu, Leo Liu, Tianjun Han, Qimin Feng, Keith W Moored, Qiang Zhong, Daniel B Quinn
Rays and skates tend to have different fin kinematics depending on their proximity to a ground plane such as the sea-floor. Near the ground, rays tend to be more undulatory (high wavenumber), while far from the ground, rays tend to be more oscillatory (low wavenumber). It is unknown whether these differences are driven by hydrodynamics or other biological pressures. Here, we show that near the ground, the time-averaged lift on a ray-like fin is highly dependent on wavenumber. We support our claims using a ray-inspired robotic rig that can produce oscillatory and undulatory motions on the same fin. Potential flow simulations reveal that lift is always negative because quasi-steady forces overcome wake-induced forces. Three-dimensional flow measurements demonstrate that oscillatory wakes are more disrupted by the ground than undulatory wakes. All these effects lead to a suction force towards the ground that is stronger and more destabilizing for oscillatory fins than undulatory fins. Our results suggest that wavenumber plays a role in the near-ground dynamics of ray-like fins, particularly in terms of dorsoventral accelerations. The fact that lower wavenumber is linked with stronger suction forces offers a new way to interpret the depth-dependent kinematics of rays and ray-inspired robots.
{"title":"Wavenumber affects the lift of ray-inspired fins near a substrate.","authors":"Yuanhang Zhu, Leo Liu, Tianjun Han, Qimin Feng, Keith W Moored, Qiang Zhong, Daniel B Quinn","doi":"10.1098/rsif.2025.0276","DOIUrl":"10.1098/rsif.2025.0276","url":null,"abstract":"<p><p>Rays and skates tend to have different fin kinematics depending on their proximity to a ground plane such as the sea-floor. Near the ground, rays tend to be more undulatory (high wavenumber), while far from the ground, rays tend to be more oscillatory (low wavenumber). It is unknown whether these differences are driven by hydrodynamics or other biological pressures. Here, we show that near the ground, the time-averaged lift on a ray-like fin is highly dependent on wavenumber. We support our claims using a ray-inspired robotic rig that can produce oscillatory and undulatory motions on the same fin. Potential flow simulations reveal that lift is always negative because quasi-steady forces overcome wake-induced forces. Three-dimensional flow measurements demonstrate that oscillatory wakes are more disrupted by the ground than undulatory wakes. All these effects lead to a suction force towards the ground that is stronger and more destabilizing for oscillatory fins than undulatory fins. Our results suggest that wavenumber plays a role in the near-ground dynamics of ray-like fins, particularly in terms of dorsoventral accelerations. The fact that lower wavenumber is linked with stronger suction forces offers a new way to interpret the depth-dependent kinematics of rays and ray-inspired robots.</p>","PeriodicalId":17488,"journal":{"name":"Journal of The Royal Society Interface","volume":"22 231","pages":"20250276"},"PeriodicalIF":3.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12520773/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145292689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}