Journal of The Royal Society Interface最新文献

A long-standing goal of evolutionary developmental biology is to identify the rules by which processes governing individual cells scale up to organism-level patterning. The viscoelastic properties of embryonic tissues imply collective cell behaviours, leading to the expectation that gene regulatory networks should capitalize on the material properties of tissues. Here, we show that large-scale variation in morphogenesis can be traced to cell-level dynamic. In avian beak primordia, we find that fields of mesenchymal cells undergo cycles of local jamming that predictably change coordination of cell shapes and movements. These cycles, in turn, alter the spatial reach of regulatory proteins, shaping their gradients in relation to tissue mechanical state. Long-range gradients of proteins most sensitive to local jamming differ the most across populations and, through their priming of tissue compartmentalization, can facilitate evolutionary divergence in beak morphology. Jamming transitions might thus allow these tissues to reconcile seemingly contradictory needs: robust maintenance, facilitated by jamming phase that resets or synchronizes cells, and adaptive flexibility, promoted by unjamming phase, that allow rearrangements, explorations or expansions. These transitions can also integrate stochastic physical processes and biological regulation allowing local rules governing cell behaviours to propagate to tissue-level patterning, ultimately promoting diversification and plasticity while preserving robustness.

The spatial organization of organic/inorganic components at the cartilage-bone interface in the human growth plate remains poorly understood. This study uses time-of-flight secondary ion mass spectrometry (ToF-SIMS) for the first time on human growth plate samples to provide insights into these interfaces. Three polydactyly specimens were analysed to map spatial variations of hydroxyapatite and collagen-related components. Regions of interest were statistically evaluated using Dunn's multiple comparisons and Spearman correlations. The calcified cartilage interface represents a critical transition zone, marked by a sharp decline in organic matrix components (e.g. CH₄N⁺) and a concurrent increase in mineral fragments (CaPO₂⁺, Ca⁺), particularly evident in large-area images. A significant peak in the Ca⁺/CH₄N⁺ ratio (p < 0.0001) highlighted a rapid shift from organic-rich to mineral-rich composition. Correlations between organic (CNO⁻) and mineral (PO₂⁻) markers indicated early-stage mineralization, while phosphate and mineralized bone fragments confirmed full mineralization (trabecular and cortical bone). Results were consistent with existing literature, supporting a structured, progressive mineralization pattern characteristic of endochondral ossification. This study demonstrates the first application of ToF-SIMS on human growth plate samples from polydactyly cases, highlighting the capacity of ToF-SIMS for large-scale imaging of human growth plate interfaces and its potential relevance to orthopaedic research.

Targeted dengue interventions require reliable estimates of transmission intensity and population immunity at the local level. The force of infection (FOI) provides an objective measure of transmission intensity, but its estimation traditionally relies on resource-intensive seroprevalence surveys. We developed a hierarchical extension of existing catalytic models to estimate FOI using routine age-stratified surveillance data, allowing partial pooling of information across districts within provinces. We applied this approach to dengue surveillance data from Jakarta and West Java provinces, Indonesia, and compared it with non-hierarchical implementations. Both hierarchical and non-hierarchical approaches produced FOI estimates consistent with 2014 seroprevalence data. The hierarchical framework provided more robust estimates through partial pooling under varied data availability scenarios but showed sensitivity to age-stratification choices and could miss district-specific patterns when local epidemiology differed from regional trends. Model comparison using expected log pointwise predictive density showed that accounting for overdispersion through negative binomial likelihood improved model performance regardless of hierarchical structure. Our analysis showed distinct patterns in reporting parameters between provinces, with Jakarta showing higher reporting rates despite lower FOI estimates than West Java. Implementation of the hierarchical framework requires understanding of local dengue epidemiology, as clustering districts with different epidemiological profiles could produce inaccurate estimates.

The contact network structure resulting from social interaction between people is a key aspect of epidemic dynamics and control. While many studies have measured first-order network characteristics such as degree, measuring higher order properties of these networks, such as clustering, remains a challenge. Here, we present the results of a study of first- and second-order network structure from a representative cohort of individuals in Guangdong province, China. The number of reported daily contacts is similar across individuals aged 2 to 55 years, except for young adults (ages 16-25) who have relatively fewer daily contacts, while the number of contacts declines with age above 55 years old. The association between age and contact rate persisted after adjusting for mediating factors. Individuals living in higher population density areas made more contacts outside the home than individuals in low-density areas. Contacts of young children and older adults were more locally clustered than middle-aged adults. Individuals living in high population density areas had lower levels of local clustering compared with individuals from low-density areas. Adjustment for characteristics of the contacts themselves reduces the variation in local clustering between participants of different ages; however, the strong association with population density remains.

Play is a quintessential human behaviour, underpinned by motor organisation and fundamental for learning and development. However, the motor patterns underlying play have not been computationally characterised in children with autism, despite known play pattern differences, including reduced social and pretend play. Recent evidence of fundamental neuromotor disruption in autism suggests neuromotor organisation differences may underpin play differences. We employed a digital game to examine play patterns in 878 children aged 2.5-6 years old, including 372 diagnosed with autism spectrum disorders (ASD), 64 diagnosed with other neurodevelopmental disorders and 441 without known neurodevelopmental problems (WP). Computational characterisation of play patterns by network analysis revealed significant differences between groups in the motor organisation of its sequential steps. Children with ASD developed an indirect, two-step pattern during the social food-sharing aspect of the game, in contrast to a direct, single-step pattern by WP children. These findings provide new variables for the digital characterisation of ASD. They reveal differences in the sequential nature of goal-directed motor organisation made in play in autism that precede higher-order differences in social cognition and emotional regulation reported in the literature, giving important insight into the psychomotor nature of autism for its education, care and support.

How do animals coordinate their motion during migration? Traditional models of movement coordination, for example, describing bird flocks or fish schools, rely on visual interactions. However, many animals are blind, requiring movement coordination through the maintenance of physical contact. The risks and cost of becoming accidentally separated may encourage the evolution of compensatory strategies. Here, we study tandem running in blind termites. We quantitatively investigate how these animals use their appendages to maintain stable pair movements. During tandem runs, male followers use their palps and antennae to maintain physical contact with female leaders. Our posture-tracking analysis revealed that termites dynamically change their antennal movements. Males stabilize their antennae to maintain contact with their partners while their palps are in contact. When the male palps lost contact with a female, males started swinging antennae while increasing movement speed. Antenna removal experiments revealed that antennal swinging contributes to pair maintenance, and males compensate for single antenna loss by increasing the swinging of the remaining one. By providing detailed information on contact-based movement coordination, our results contribute to understanding the diversity of animal collective motion.

The biomechanical behaviour of vascular tissues is influenced by the presence of residual stresses, yet their role in vascular adaptation to pathological conditions remains largely unexplored. These residual stresses may arise within the vessel wall as a result of growth and remodelling (G&R) processes governed by the principles of tensional homeostasis. This study extends our previous work by refining a computational workflow that integrates homeostasis-driven G&R into patient-specific carotid geometries. Key advancements include adopting a total Lagrangian framework to handle complex geometries, introducing novel post-processing metrics for improved comparisons and conducting statistical analyses to assess G&R's impact on biomechanical evaluations of atherosclerotic vessels. These improvements enabled the analysis of a cohort of 18 cases, incorporating patient-specific geometries and pathological tissue distributions reconstructed from clinical imaging data. Results suggest that G&R generally reduces peak stress, though its effectiveness depends on plaque morphology and tissue composition. High calcification leads to localized stress concentrations, limiting remodelling, whereas matrix-rich regions promote stress homogenization. At the cohort level, findings underscore the need for patient-specific analyses in plaque risk evaluation, reinforcing the importance of personalized biomechanical modelling in assessing atherosclerotic disease and guiding clinical decision-making.

Human cooperation arises naturally and is essential for the development of successful societies. This study aims to identify which aspects of the interaction influence societal cooperation and defection. Specifically, we investigate human cooperation within the framework of the Multiplayer Iterated Prisoner's Dilemma game, modelling the decision-making process by using the drift-diffusion model (DDM). We propose a novel Bayesian model for the evolution of the DDM parameters, based on the nature of interactions experienced with other players. This approach enables us to predict the evolution of the expected rate of cooperation within the population. We successfully validate our model using an unseen test dataset-separated from the training one-and apply it to explore three strategic scenarios known from previous research to affect cooperation: (i) manipulation of co-players, (ii) the use of rewards and punishments, and (iii) time pressure. Our model successfully explains the test dataset and behaves consistently with established findings in the literature on human behaviour in these simulated scenarios. These results support the potential of our model as a foundational tool for developing and testing strategies that foster cooperation, improving our ability to study, understand and intervene in scenarios where individual and collective interests conflict.

Cell competition is a fitness control mechanism in tissues, where less fit cells are eliminated to maintain tissue homeostasis. Two primary mechanisms of cell competition have been identified: contact-dependent apoptosis and mechanical stress-induced competition. While both operate in tissues, their combined impact on population dynamics is unclear. Here, we present a cell-based computational model that integrates cellular mechanics with proliferation, contact-induced apoptosis and mechanically triggered apoptosis to investigate competition between two distinct cell types. Using this framework, we systematically examine how differences in physical traits-such as stiffness, adhesion and crowding sensitivity-govern competitive outcomes. Our results show that apoptosis rates alone are insufficient to predict cell fate; differences in proliferation and contact inhibition play equally important, context-dependent roles. Notably, we find that increased cell stiffness can confer a fitness advantage, enabling stiffer cells to outcompete softer neighbours. However, cells with reduced stiffness can become 'soft' supercompetitors if they exhibit faster growth and lower sensitivity to crowding. We also demonstrate that colony size critically influences competition: a minimum size is required for mutant expansion, below which elimination becomes stochastic. This stochastic clearance is driven by a protrusive instability in the interface between two cells that promotes invasion of the supercompetitors.

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.