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Hydra has a tubular bilayered epithelial body column with a dome-shaped head on one end and a foot on the other. Hydra lacks a permanent mouth: its head epithelium is sealed. Upon neuronal activation, a mouth opens at the apex of the head which can exceed the body column diameter in seconds, allowing Hydra to ingest prey larger than itself. While the kinematics of mouth opening are well characterized, the underlying mechanism is unknown. We show that Hydra mouth opening is generated by independent local contractions that require tissue-level coordination. We model the head epithelium as an active viscoelastic nonlinear spring network. The model reproduces the size, timescale and symmetry of mouth opening. It shows that radial contractions, travelling inwards from the outer boundary of the head, pull the mouth open. Nonlinear elasticity makes mouth opening larger and faster, contrary to expectations. The model correctly predicts changes in mouth shape in response to external forces. By generating innervated : nerve-free chimera in experiments and simulations, we show that nearest-neighbour mechanical signalling suffices to coordinate mouth opening. Hydra mouth opening shows that in the absence of long-range chemical or neuronal signals, short-range mechanical coupling is sufficient to produce long-range order in tissue deformations.

Based on empirical evidences and previous studies, we introduce and mathematically study a perception-driven model for the dynamics of buyer populations in markets of perishable goods. Buyer behaviours are driven partly by some loyalty to the sellers that they previously purchased at, and partly by the sensitivity to the intrinsic attractiveness of each seller in the market. On the other hand, the sellers update they attractiveness in time according to the difference between the volume of their clientele and the mean volume of buyers in the market, optimising either their profit when this difference is favourable or their competitiveness otherwise. While this negative feedback mechanism is a source of instability that promotes oscillatory behaviour, our analysis identifies the critical features of the dynamics that are responsible for the asymptotic stability of the stationary states, both in their immediate neighbourhood and globally in phase space. Altogether, this study provides mathematical insights into the consequences of introducing feedback into buyer–seller interactions in such markets, with emphasis on identifying conditions for long-term constancy of clientele volumes. [ABSTRACT FROM AUTHOR]

Meditation, psychedelics, and other similar practices or induction methods that can modulate conscious experience, are becoming increasingly popular in clinical and non-clinical settings. The phenomenology associated with such practices or modalities is vast. Many similar effects and experiences are also reported to occur spontaneously. We argue that this experiential range is still not fully described or understood in the contemporary literature, and that there is an ethical mandate to research it more extensively, starting with comprehensive documentation and definition. We review 50 recent clinical or scientific publications to assess the range of phenomena, experiences, effects, after-effects, and impacts associated with a broad variety of psychoactive compounds, meditative practices, and other modalities or events. This results in a large inventory synthesizing the reports of over 30,000 individual subjects. We then critically discuss various terms and concepts that have been used in recent literature to designate all or parts of the range this inventory covers. We make the case that specialized terminologies are needed to ground the nascent research field that is forming around this experiential domain. As a step in this direction, we propose the notion of “emergence” and some of its derivatives, such as “emergent phenomenology,” as possibly foundational candidates. [ABSTRACT FROM AUTHOR]

Engineering projects for complex technical systems such as automobiles demand extensive requirement specifications and corresponding hierarchy levels in system architectures. Especially when considering emergent phenomena, such as total weight or aerodynamics, a closely networked collaboration of discipline‐specific and cross‐disciplinary roles is required. Further, in large organizations with a group structure, resulting functional and non‐functional contents need to be managed by distinct Systems Engineering roles. For example, the role "property manager" takes care of achieving overarching product properties, such as weight or aerodynamics, which cannot be directly fixed, but result from many specifications. This paper proposes new Systems Engineering roles and their application in a German Original Equipment Manufacturer (OEM). For validation, the roles have already been applied in everyday engineering projects at the OEM. The concept proved to be indispensable and transferable to other Systems Engineering projects. [ABSTRACT FROM AUTHOR]

Objectives: Adoption of potentially consciousness-altering practices may be leading to a rise in emergent phenomena (EP): sudden unusual mental or somatic experiences often interpreted as spiritual, mystical, energetic, or magical in nature. It is unclear how frequently these altered states of consciousness occur and what the clinical implications may be. Anecdotal accounts and prior literature suggest that EP may be common, under-reported, and followed by either positive or negative changes to well-being. We sought to supplement prior evidence on the prevalence and effects of EP among general populations with large-scale quantitative measurements. Method: We measured the prevalence of EP, while not on mind-altering substances, through completion of online surveys by representative samples from three international communities (n = 3135). The communities sampled were UK Qualtrics online panelists, US-based MTurk workers, and the readers of a popular rationalist blog. Samples were broadly representative of underlying populations. Results: Forty-five percent of participants reported experiencing non-pharmacologically induced EP at least once in their lives, including derealization (17%), unitive experiences (15%), ecstatic thrills (15%), vivid perceptions (11%), changes in perceived size (10%), bodily heat or electricity (9%), out-of-body experiences (8%), and perception of non-physical lights (5%). Respondents reported a mix of positive and negative well-being outcomes following EP, with 13% claiming moderate or greater suffering and 1.1% claiming life-threatening suffering. Of those who experienced suffering, 63% did not seek help. Conclusions: EP are widespread among the studied populations with potential for both positive and negative outcomes, the latter of which do not appear to be adequately addressed through recourse to clinical practice. [ABSTRACT FROM AUTHOR]

Using a lipopolysaccharide model of acute lung injury, we previously showed that endothelin-1 (ET-1), a potent mediator of vasoconstriction, may act as a "gatekeeper" for the influx of inflammatory cells into the lung. These studies provided a rationale for testing the effect of HJP272, an endothelin receptor antagonist (ERA), in hamster models of pulmonary fibrosis induced by intratracheal instillation of either bleomycin (BLM) or amiodarone (AM). To determine the temporal effects of blocking ET-1 activity, animals were given HJP272 either 1 h before initiation of lung injury or 24 h afterward. The results indicated that pretreatment with this agent caused significant reductions in various inflammatory parameters, whereas post-treatment was ineffective. This finding suggests that ERAs are only effective at a very early stage of pulmonary fibrosis and explains their lack of success in clinical trials involving patients with this disease. Nevertheless, ERAs could serve as prophylactic agents when combined with drugs that may induce pulmonary fibrosis. Furthermore, developing a biomarker for the initial changes in the lung extracellular matrix could increase the efficacy of ERAs and other therapeutic agents in preventing the progression of the disease. While no such biomarker currently exists, we propose the ratio of free to peptide-bound desmosine, a unique crosslink of elastin, as a potential candidate for detecting the earliest modifications in lung microarchitecture associated with pulmonary fibrosis. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this article is to draw attention to the specificity of emergent phenomena in organization and management, the study of which requires an approach derived from complex adaptive systems. Design/methodology/approach: The article uses a critical analysis of research on emergent phenomena in organizations from the perspective of complex social systems. This analysis made it possible to distinguish types of emergence in organization and management depending on the type of agents (members) and interactions that take place in the organization and indicated the causes of emergent phenomena. Findings: The article creates a research framework for complex emergent phenomena and shows how to use computer simulation to study complex emergent phenomena in organizations. Originality/value: A relatively new direction of research are analyzes within the theory of complex adaptive systems, the aim of which is to model and explain the behavior of systems of interconnected objects based on knowledge about the laws of individual elements (at the local level) and the structure of their connections. Therefore, it seems interesting to use computer tools developed based on complexity theory, especially agent-based models, as proposed in this article to study emergent phenomena in organizations. Since there are many approaches and ways of using computer simulations to study complex adaptation phenomena, a method of creating a simulation model and a method of conducting research using it were proposed. [ABSTRACT FROM AUTHOR]

Developing an effective treatment for pulmonary emphysema will require a better understanding of the molecular changes responsible for distention and rupture of alveolar walls. A potentially useful approach to studying this process involves the concept of emergence in which interactions at different levels of scale induce a phase transition comprising a spontaneous reorganization of chemical and physical systems. Recent studies in our laboratory provide evidence of this phenomenon in pulmonary emphysema by relating the emergence of airspace enlargement to the release of elastin-specific desmosine and isodesmosine (DID) crosslinks from damaged elastic fibers. When the mean alveolar diameter exceeded 400 μm, the level of peptide-free DID in human lungs was greatly increased, reflecting rapid acceleration of elastin breakdown, alveolar wall rupture, and a phase transition to an active disease state that is less responsive to treatment. Based on this finding, it is hypothesized that free DID in urine and other body fluids may serve as a biomarker for early detection of airspace enlargement, thereby facilitating timely therapeutic intervention and reducing the risk of respiratory failure.

Neuromorphic computing-which aims to mimic the collective and emergent behavior of the brain's neurons, synapses, axons, and dendrites-offers an intriguing, potentially disruptive solution to society's ever-growing computational needs. Although much progress has been made in designing circuit elements that mimic the behavior of neurons and synapses, challenges remain in designing networks of elements that feature a collective response behavior. We present simulations of networks of circuits and devices based on superconducting and Mott-insulating oxides that display a multiplicity of emergent states that depend on the spatial configuration of the network. Our proposed network designs are based on experimentally known ways of tuning the properties of these oxides using light ions. We show how neuronal and synaptic behavior can be achieved with arrays of superconducting Josephson junction loops, all within the same device. We also show how a multiplicity of synaptic states could be achieved by designing arrays of devices based on hydrogenated rare earth nickelates. Together, our results demonstrate a research platform that utilizes the collective macroscopic properties of quantum materials to mimic the emergent behavior found in biological systems.

Organizations develop different methodologies for product, customization, and improvement. In time, the best-known methods and practices are established and standardized for new product development. However, to enhance performance and outcomes, customization is typically needed and requires additional time and effort, requiring a high learning curve. An approach of operational planning to ascertain projected outcomes for a variety of scenarios is agent-based modeling and simulation. This study focuses on product design, an essential aspect of new products. An agent-based model (ABM) has been developed using a paradigm of the design management organizational function represented by four autonomous agents, their actions, and interactions. The objective is to assess the aggregate emergent behavior of the design management organization. Research questionnaires are used to obtain data consisting of agent characteristics from firms covering services and manufacturing, across multiple industry sectors. An initial network of design-related agents was developed based on the collected data. Simulation of the model provided data consisting on a time series of units sold by the simulated organization. NetLogo-based simulations indicated responsiveness in organizational behavior when customer satisfaction drops, in terms of fitness to specifications. This behavior resulted in reversing negative trends in units sold. The time scale of the simulation, metric levels, and behavior was validated using sales data from a company in the electronics manufacturing industry. This model provides guidance on how to configure new product development teams, modifying designer hiring processes, scheduling product development committees, and plan customer feedback collection. [ABSTRACT FROM AUTHOR]

Studies of active matter—systems consisting of individuals or ensembles of internally driven and damped locomotors—are of interest to physicists studying nonequilibrium dynamics, biologists interested in individuals and swarm locomotion, and engineers designing robot controllers. While principles governing active systems on hard ground or within fluids are well studied, another class of systems exists at deformable interfaces. Such environments can display mixes of fluid-like and elastic features, leading to locomotor dynamics that are strongly influenced by the geometry of the surface, which, in itself, can be a dynamical entity. To gain insight into principles by which locomotors are influenced via a deformation field alone (and can influence other locomotors), we study robot locomotion on an elastic membrane, which we propose as a model of active systems on highly deformable interfaces. As our active agent, we use a differential driven wheeled robotic vehicle which drives straight on flat homogeneous surfaces, but reorients in response to environmental curvature. We monitor the curvature field–mediated dynamics of a single vehicle interacting with a fixed deformation as well as multiple vehicles interacting with each other via local deformations. Single vehicles display precessing orbits in centrally deformed environments, while multiple vehicles influence each other by local deformation fields. The active nature of the system facilitates a differential geometry–inspired mathematical mapping from the vehicle dynamics to those of test particles in a fictitious “spacetime,” allowing further understanding of the dynamics and how to control agent interactions to facilitate or avoid multivehicle membrane-induced cohesion. [ABSTRACT FROM AUTHOR]

· Holistic models are needed to capture ecosystem complexity and connectivity. · The Virtual Ecosystem connects plant, animal, soil microbial and abiotic domains. · Such models can unify the understanding of ecosystems among disciplines. The myriad interactions among individual plants, animals, microbes and their abiotic environment generate emergent phenomena that will determine the future of life on Earth. Here, we argue that holistic ecosystem models – incorporating key biological domains and feedbacks between biotic and abiotic processes and capable of predicting emergent phenomena – are required if we are to understand the functioning of complex, terrestrial ecosystems in a rapidly changing planet. We argue that holistic ecosystem models will provide a framework for integrating the many approaches used to study ecosystems, including biodiversity science, population and community ecology, soil science, biogeochemistry, hydrology and climate science. Holistic models will provide new insights into the nature and importance of feedbacks that cut across scales of space and time, and that connect ecosystem domains such as microbes with animals or above with below ground. They will allow us to critically examine the origins and maintenance of ecosystem stability, resilience and sustainability through the lens of systems theory, and provide a much-needed boost for conservation and the management of natural environments. We outline our approach to developing a holistic ecosystem model – the Virtual Ecosystem – and argue that while the construction of such complex models is obviously ambitious, it is both feasible and necessary. [ABSTRACT FROM AUTHOR]

The 2021 Nobel Prize in Physics recognized the fundamental role of complex systems in the natural sciences. In order to celebrate this milestone, this editorial presents the point of view of the editorial board of JPhys Complexity on the achievements, challenges, and future prospects of the field. To distinguish the voice and the opinion of each editor, this editorial consists of a series of editor perspectives and reflections on few selected themes. A comprehensive and multi-faceted view of the field of complexity science emerges. We hope and trust that this open discussion will be of inspiration for future research on complex systems.

Local social interactions among individuals in animal groups generate collective behavior, allowing groups to adjust to changing conditions. Historically, scientists from different disciplines have taken different approaches to modeling collective behavior. We describe how each can contribute to the goal of understanding natural systems. Simple bottom-up models that describe individuals and their interactions directly have demonstrated that local interactions far from equilibrium can generate collective states. However, such simple models are not likely to describe accurately the actual mechanisms and interactions in play in any real biological system. Other classes of top-down models that describe group-level behavior directly have been proposed for groups where the function of the collective behavior is understood. Such models cannot necessarily explain why or how such functions emerge from first principles. Because modeling approaches have different strengths and weaknesses and no single approach will always be best, we argue that models of collective behavior that are aimed at understanding real biological systems should be formulated to address specific questions and to allow for validation. As examples, we discuss four forms of collective behavior that differ both in the interactions that produce the collective behavior and in ecological context, and thus require very different modeling frameworks. 1) Harvester ants use local interactions consisting of brief antennal contact, in which one ant assesses the cuticular hydrocarbon profile of another, to regulate foraging activity, which can be modeled as a closed-loop excitable system. 2) Arboreal turtle ants form trail networks in the canopy of the tropical forest, using trail pheromone; one ant detects the volatile chemical that another has recently deposited. The process that maintains and repairs the trail, which can be modeled as a distributed algorithm, is constrained by the physical configuration of the network of vegetation in which they travel. 3) Swarms of midges interact acoustically and non-locally, and can be well described as agents moving in an emergent potential well that is representative of the swarm as a whole rather than individuals. 4) Flocks of jackdaws change their effective interactions depending on ecological context, using topological distance when traveling but metric distance when mobbing. We discuss how different research questions about these systems have led to different modeling approaches.

We explore the concept of emergent quantum-like theory in complex adaptive systems, and examine in particular the concrete example of such an emergent (or "mock") quantum theory in the Lotka–Volterra system. In general, we investigate the possibility of implementing the mathematical formalism of quantum mechanics on classical systems, and what would be the conditions for using such an approach. We start from a standard description of a classical system via Hamilton–Jacobi (HJ) equation and reduce it to an effective Schrodinger-type equation, with a (mock) Planck constant ▪ , which is system-dependent. The condition for this is that the so-called quantum potential V Q , which is state-dependent, is canceled out by some additional term in the HJ equation. We consider this additional term to provide for the coupling of the classical system under consideration to the 'environment'. We assume that a classical system could cancel out the V Q term (at least approximately) by fine tuning to the environment. This might provide a mechanism for establishing a stable, stationary states in (complex) adaptive systems, such as biological systems. In particular, we present a general argument as to why the non-equilibrium dynamics of a classical system could lead to a mock quantum description that ensures stability compatible with adaptability. In this context we emphasize the state dependent nature of the mock quantum dynamics and we also introduce the new concept of the mock quantum, state dependent, statistical field theory. We also discuss some universal features of the quantum-to-classical as well as the mock-quantum-to-classical transition found in the turbulent phase of the hydrodynamic formulation of our proposal. In this way we re-frame the concept of decoherence into the concept of 'quantum turbulence', i.e. that the transition between quantum and classical could be defined in analogy to the transition from laminar to turbulent flow in hydrodynamics. • Emergent Quantum-like theory in classical systems – "Mock Quantum" theory. • Mock quantum - a theory for stability in complex adaptive systems. • Non-equilibrium dynamics of a classical complex system in quantum like description. • Implementation of the Mock Quantum theory in the Lotka–Volterra model. • Quantum-Classical and Mock_Quantum–Classical transitions as hydrodynamic processes. [ABSTRACT FROM AUTHOR]

The economy as a whole and most of its constituent parts, like markets, government institutions, firms, or households, are inherently complex conceptual constructions. Micro-level diversity, decentralized interaction, self-organization, adaptation and learning, emergence, and evolution, are some of the fundamental features that the above entities share and that allow to classify them as being complex entities. In a complex economic system, existing structures of interaction are in constant mutation as individual agents contact and influence one another and, by doing so, reshape the macro environment in which socio-economic relations unfold. Notwithstanding the observed pervasiveness of complexity in economics, there are a few areas of economic thought where the discussion on the theme has gained an exceptional relevance. In this article, six of such areas are identified and their complex nature is highlighted and scrutinized. These pertain to: (i) Knowledge interactions and technological innovation; (ii) Corporate design and organizational learning; (iii) Public policies directed at market regulation; (iv) Banking and financial markets; (v) Environmental economics, sustainability, and climate change; and (vi) income inequality. [ABSTRACT FROM AUTHOR]

Abstract—Gaze following, the ability to redirect one’s visual at- tention to look at what another person is seeing, is foundational for imitation, word learning, and theory-of-mind. Previous theories have suggested that the development of gaze following in human infants is the product of a basic gaze following mechanism, plus the gradual incorporation of several distinct new mechanisms that im- prove the skill, such as spatial inference, and the ability to use eye direction information as well as head direction. In this paper, we offer an alternative explanation based on a single learning mecha- nism. From a starting state with no knowledge of the implications of another organism’s gaze direction, our model learns to follow gaze by being placed in a simulated environment where an adult caregiver looks around at objects. Our infant model matches the development of gaze following in human infants as measured in key experiments that we replicate and analyze in detail.

Emergency goods distribution plays an important role in the grid emergency relief command system. However, the traditional experience-based distribution plan currently in the power grid cannot meet the increasing demand for the types and quantities of emergency goods, meanwhile, most studies ignore the uncertainty in distribution parameters and diversification of distribution objectives, which causes a gap between theoretical research and practical application. Therefore, this paper establishes a model to guide the logistics design for transferring relief supplies. The model first assesses the importance of affected areas for determining distribution priority based on the electrical characteristics. To better simulate reality, the uncertainties in demand, supply, and the costs of procurement and transportation are considered. Additionally, the model features three objectives: shortening the travel time, reducing the goods shortage, and saving the total cost of pre- and post-disaster phases. In order to handle the uncertainties, the robust optimization approach is utilized. The numerical example is solved with ε-constraint exact method, and this case illustrates the specific process of goods distribution, the relationship between objectives, and the sensitivity analysis of uncertainties. For the large-size forms, two heuristic algorithms are proposed and the efficiency of the proposed algorithms is assessed.

Background and Overview: The conceptualization of personality pathology, or personality disturbance, is now at a substantive crossroads. Some researchers (and clinicians) prefer a focus on the domains of personality pathology that are well-described and captured in traditional categorical diagnostic approaches that, in some instances, abut normal personality constructs. Other workers argue to move the study of personality disorder (PD) closer to personality science seeking continuous connections between PD and established dimensions of healthy-range, normal personality. Most of the latter efforts revolve around correlational and factor analytic study of phenotypic expressions of PD features and normal personality dimensions. It is notable, however, that both visions of the PD/personality interface are essentially unlinked to an understanding of shared neurobiological underpinnings (i.e., neurotransmitter-influenced neurobehavioral systems) of both personality disturbance and normal personality1. Here, we present a nontechnical, conceptual overview of our approach to this problem, advancing a neurobehavioral approach that seeks to anchor both normal personality and personality disturbance within a matrix of brain-based neurobiological systems, incorporating genetic, epigenetic, and environmental inputs. In this brief paper, we seek only to provide a necessarily cursory introduction to how we conceptualize this area and illustrate, in broad outline, our effort to characterize both personality and personality disturbance anchored in neurobehavioral systems. Our approach, which we began developing in the middle 1990s, can be juxtaposed with the more recently proposed DSM-5 Alternative Model of Personality Disorders as well as the well-established five-factor approach to PD. [ABSTRACT FROM AUTHOR]

This paper was written in honor of Prof. Ted Geballe's 100th birthday. It concerns a new emergent phenomenon called three-dimensional negative electronic compressibility. The physical content, driving mechanism, and context of the initial discovery of this phenomenon in an iridate material are reviewed. An integrative approach based on multiple experimental methods for carrier concentration modulation and chemical potential shift measurement is proposed for the quest of this phenomenon in other materials. Its implications on the physical properties of materials, in particular terms of electrostatic screening and phase separation, are discussed along with some of its unique prospects for applications. [ABSTRACT FROM AUTHOR]

We consider a stochastic process which is (a) described by a continuous-time Markov chain on only short time-scales and (b) constrained to conserve a number of hidden quantities on long time-scales. We assume that the transition matrix of the Markov chain is given and the conserved quantities are known to exist, but not explicitly given. To study the stochastic dynamics we propose to use the principle of stationary entropy production. Then the problem can be transformed into a variational problem for a suitably defined "action" and with time-dependent Lagrange multipliers. We show that the stochastic dynamics can be described by a Schrödinger equation, with Lagrange multipliers playing the role of phases, whenever (a) the transition matrix is symmetric or the detailed balance condition is satisfied, (b) the system is not too far from the equilibrium and (c) the number of the conserved quantities is large. [ABSTRACT FROM AUTHOR]

Developing an effective treatment for pulmonary emphysema will require a better understanding of the molecular changes responsible for distention and rupture of alveolar walls. A potentially useful approach to studying this process involves the concept of emergence in which interactions at different levels of scale induce a phase transition comprising a spontaneous reorganization of chemical and physical systems. Recent studies in our laboratory provide evidence of this phenomenon in pulmonary emphysema by relating the emergence of airspace enlargement to the release of elastin-specific desmosine and isodesmosine (DID) crosslinks from damaged elastic fibers. When the mean alveolar diameter exceeded 400 μm, the level of peptide-free DID in human lungs was greatly increased, reflecting rapid acceleration of elastin breakdown, alveolar wall rupture, and a phase transition to an active disease state that is less responsive to treatment. Based on this finding, it is hypothesized that free DID in urine and other body fluids may serve as a biomarker for early detection of airspace enlargement, thereby facilitating timely therapeutic intervention and reducing the risk of respiratory failure., Competing Interests: The author has a financial interest in MatRx Therapeutics, which is developing the use of hyaluronan as a treatment for chronic obstructive pulmonary disease. He also is listed as an inventor on USPTO 17/821,672, which includes a method for measuring desmosine with liquid chromatography and tandem mass spectrometry., (Copyright © 2023 Cantor.)