Cells act as building blocks of multicellular organisms, forming higher-order structures at different biological scales. Niches, tissues and, ultimately, entire organisms consist of single cells that ...remain in constant communication. Emergence of developmental patterns and tissue architecture thus relies on single cells acting as a collective, coordinating growth, migration, cell fate transitions and cell type sorting. For this, information has to be transmitted forward from cells to tissues and fed back to the individual cell to allow dynamic and robust coordination. Here, we define the design principles of tissue organisation integrating chemical, genetic and mechanical cues. We also review the state-of-the-art technologies used for dissecting collective cellular behaviours at single cell– and tissue-level resolution. We finally outline future challenges that lie in a comprehensive understanding of how single cells coordinate across biological scales to insure robust development, homoeostasis and regeneration of tissues.
•Self-organising swarms of drones designed to engage in autonomous fire suppression.•Focus on self-coordination mechanisms for desired firefighting behaviour to emerge.•Particle swarm algorithm ...adapted to physical dynamic environments of high severity.•Efficient physics-based two-dimensional model of fire propagation (calibrated).•Scalability and fault-tolerance of fire-fighting system.
Swarm intelligence (SI) is concerned with the collective behaviour that emerges from decentralised self-organising systems, whilst swarm robotics (SR) is an approach to the self-coordination of large numbers of simple robots which emerged as the application of SI to multi-robot systems. Given the increasing severity and frequency of occurrence of wildfires and the hazardous nature of fighting their propagation, the use of disposable inexpensive robots in place of humans is of special interest. This paper demonstrates the feasibility and potential of employing SR to fight fires autonomously, with a focus on the self-coordination mechanisms for the desired firefighting behaviour to emerge. Thus, an efficient physics-based model of fire propagation and a self-organisation algorithm for swarms of firefighting drones are developed and coupled, with the collaborative behaviour based on a particle swarm algorithm adapted to individuals operating within physical dynamic environments of high severity and frequency of change. Numerical experiments demonstrate that the proposed self-organising system is effective, scalable and fault-tolerant, comprising a promising approach to dealing with the suppression of wildfires – one of the world's most pressing challenges of our time.
The COVID-19 pandemic that gripped the world since the end of 2019 has been felt most immediately both as a health crisis and an economic, social and political crisis. Secondary impacts of social ...distancing and lockdown in many countries have put strains on people’s capacities to provide essential food and medicines for themselves and their families. In response, outside of centralised government and voluntary sector frameworks, local mutual aid groups have emerged around the world as a primary site of community resilience. Given mutual aid’s strong links to the anarchist political tradition, for example in its identification by Kropotkin as a factor in evolution, this article suggests that these new mutual aid groups can be understood best through the related concept of self-organisation. Tying anarchist approaches to mutual aid and self-organisation together, it is argued that cybernetics and Stafford Beer’s Viable System Model (VSM) offer useful tools in helping both academic analysis and on-the-ground practice assess and improve the effectiveness of mutual aid in and beyond the COVID-19 crisis. The article offers a qualitative thematic analysis of anarchist and related texts published during the pandemic that reflect on mutual aid practice. In doing so, it highlights some of the challenges and tensions such self-organised mutual aid practice might face and proposes a participatory research agenda drawing on Beer’s VSM.
The ‘new materialism’ is the most common name given to a series of movements in several fields that criticise anthropocentrism, rethink subjectivity by playing up the role of inhuman forces within ...the human, emphasize the self-organizing powers of several nonhuman processes, explore dissonant relations between those processes and cultural practice, rethink the sources of ethics, and commend the need to fold a planetary dimension more actively and regularly into studies of global, interstate and state politics. After reviewing several key tenets of this diverse movement in philosophy, biology and the human sciences, we focus on how it casts light on the dissonant relations between the drives of neoliberal capitalism and boomerang effects from nonhuman forces. Exploration of such relations both dramatises the fragility of things today and helps to explain why many constituencies refuse to acknowledge and address it. After presenting a few capital–force-field conjunctions that illustrate the fragility of things, this article briefly explores some intercoded counter-strategies to address the contemporary predicament.
In this article, we develop a unifying framework for the understanding of spatial vegetation patterns in heterogeneous landscapes. While much recent research has focused on self‐organised vegetation ...the prevailing view is still that biological patchiness is mostly due to top‐down control by the physical landscape template, disturbances or predators. We suggest that vegetation patchiness in real landscapes is controlled both by the physical template and by self‐organisation simultaneously, and introduce a conceptual model for the relative roles of the two mechanisms. The model considers four factors that control whether vegetation patchiness is emerged or imposed: soil patch size, plant size, resource input and resource availability. The last three factors determine the plant‐patch size, and the plant‐to‐soil patch size ratio determines the impact of self‐organisation, which becomes important when this ratio is sufficiently small. A field study and numerical simulations of a mathematical model support the conceptual model and give further insight by providing examples of self‐organised and template‐controlled vegetation patterns co‐occurring in the same landscape. We conclude that real landscapes are generally mixtures of template‐induced and self‐organised patchiness. Patchiness variability increases due to source–sink resource relations, and decreases for species of larger patch sizes.
The purpose of this article is to explore what kind of (land-use) regulation is more compatible with a radical acceptance of the idea of the complexity of socio-spatial systems and of the intrinsic ...limits of explanation and prediction. The article applies insights from complexity sciences to planning practice, critically comparing different land-use regulatory instruments (in particular, patterning-instruments and framework-instruments). The main result and conclusion is that it is necessary to embrace the challenge of complexity and self-organisation, and consequently to start profound revision of regulatory instruments.
The dynamics of pedestrian flows can be captured in a continuum modelling framework. However, compared to vehicular flow, this is a much more challenging task. In particular the integration of flow ...propagation and path choice are known to be problematic. Furthermore, pedestrian flow is characterised by different self-organised phenomena, such as the formation of dynamic lanes and diagonal stripes, which have not yet been captured in a continuum modelling framework.
This contribution puts forward a novel multi-class continuum model that captures some of the key features of pedestrian flows. It considers path choice behaviour on both the strategic (pre-trip) and tactical (en-route) level. To achieve this, we present a methodology to derive a continuum model from a microscopic walker model, in this case the social forces model. In doing so, we show that the interaction term present in the social forces model introduces a local path choice component in the equilibrium velocity.
Having derived the model, we analyse its properties both by means of mathematical analyses and simulation studies. This reveals the general behaviour of the model, as well as the ability of the model to reproduce self-organised structures, and phase transitions. To the best of our knowledge, this is the first continuum model that is able to reproduce these self-organised structures.
•State-of-the-art macroscopic model with global and local route choice behaviour.•Multi-class continuum modelling based on microscopic modelling principles (i.c. social forces model).•Derivation of explicit relation for equilibrium speed and walking direction.•Reproduction of self-organised phenomena, such as dynamic lane formation, and formation of diagonal stripes.•Preliminary results show model’s ability to also reproduce phase transitions.
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