scholarly journals Self-Organised Critical Dynamics as a Key to Fundamental Features of Complexity in Physical, Biological, and Social Networks

Dynamics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 181-197
Author(s):  
Bosiljka Tadić ◽  
Roderick Melnik
Keyword(s):  
Driving Forces ◽  
Spin Dynamics ◽  
Social Systems ◽  
Higher Order ◽  
The Self ◽  
Mathematical Framework ◽  
Critical Systems ◽  
Driving Mode ◽  
Critical Fluctuations ◽  
Temporal Correlations

Studies of many complex systems have revealed new collective behaviours that emerge through the mechanisms of self-organised critical fluctuations. Subject to the external and endogenous driving forces, these collective states with long-range spatial and temporal correlations often arise from the intrinsic dynamics with the threshold nonlinearity and geometry-conditioned interactions. The self-similarity of critical fluctuations enables us to describe the system using fewer parameters and universal functions that, on the other hand, can simplify the computational and information complexity. Currently, the cutting-edge research on self-organised critical systems across the scales strives to formulate a unifying mathematical framework, utilise the critical universal properties in information theory, and decipher the role of hidden geometry. As a prominent example, we study the field-driven spin dynamics on the hysteresis loop in a network with higher-order structures described by simplicial complexes, which provides a geometric-frustration environment. While providing motivational illustrations from physical, biological, and social systems, along with their networks, we also demonstrate how the self-organised criticality occurs at the interplay of the complex topology and driving mode. This study opens up new promising routes with powerful tools to address a long-standing challenge in the theory and applications of complexity science ingrained in the efficient analysis of self-organised critical states under the competing higher-order interactions embedded in complex geometries.

scholarly journals Simulations of Higher-Order Protein Organizations Using a Fuzzy Framework

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
B. Tüű-Szabó ◽  
L. T. Kóczy ◽  
M. Fuxreiter
Keyword(s):  
Driving Forces ◽  
Critical Role ◽  
Critical Factor ◽  
Higher Order ◽  
Mathematical Framework ◽  
Protein Assemblies ◽  
Binding Motifs ◽  
Spatiotemporal Regulation ◽  
The Impact

Spatiotemporal regulation of the biochemical information is often linked to supramolecular organizations proteins and nucleic acids, the driving forces of which have yet to be elucidated. Although the critical role of multivalency in phase transition has been recognized, the organization principles of higher-order structures need to be understood. Here, we present a fuzzy mathematical framework to handle the heterogeneity of interactions patterns and the resultant multiplicity of conformational states in protein assemblies. In this model, redundant binding motifs can establish simultaneous and partial interactions with multiple targets. We demonstrate that these multivalent, weak contacts facilitate polymer formation, while recapitulating the observed valency-dependence. In addition, the impact of linker dynamics and motif binding affinity, as well as the interplay between the two effects was studied. Our results support that fuzziness is a critical factor in driving higher-order protein organizations, and this could be used as a general framework to simulate different kinds of supramolecular assemblies.

Keynote

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Jeanne LIEDTKA
Keyword(s):  
Organizational Performance ◽  
Design Thinking ◽  
Social Systems ◽  
Field Research ◽  
Higher Order ◽  
Lens Design ◽  
Social Sector ◽  
Extensive Field ◽  
Innovative Solutions ◽  
The Impact

The value delivered by design thinking is almost always seen to be improvements in the creativity and usefulness of the solutions produced. This paper takes a broader view of the potential power of design thinking, highlighting its role as a social technology for enhancing the productivity of conversations for change across difference. Examined through this lens, design thinking can be observed to aid diverse sets of stakeholders’ abilities to work together to both produce higher order, more innovative solutions and to implement them more successfully. In this way, it acts as a facilitator of the processes of collectives, by enhancing their ability to learn, align and change together. This paper draws on both the author’s extensive field research on the use of design thinking in social sector organizations, as well as on the literature of complex social systems, to discuss implications for both practitioners and scholars interested in assessing the impact of design thinking on organizational performance.

Combined influence of axial electron temperature and exponential plasma density ramp on the self-focusing of a chirped laser in plasma

2020 ◽  
Vol 75 (7) ◽  
pp. 671-675
Author(s):  
Niti Kant ◽  
Vishal Thakur
Keyword(s):  
Electron Temperature ◽  
Pulse Laser ◽  
Plasma Density ◽  
Beam Width ◽  
Spot Size ◽  
Higher Order ◽  
The Self ◽  
Chirped Pulse ◽  
Self Focusing ◽  
Paraxial Ray

AbstractAn analysis of the self-focusing of highly intense chirped pulse laser under exponential plasma density ramp with higher order value of axial electron temperature has been done. Beam width parameter is derived by using paraxial ray approximation and then solved numerically. It is seen that self-focusing of chirped pulse laser is intensely affected by the higher order values of axial electron temperature. Further, influence of exponential plasma density ramp is studied and it is concluded that self-focusing of laser enhances and occurs earlier. On the other hand defocusing of beam reduces to the great extent. It is noticed that the laser spot size reduces significantly under joint influence of the density ramp and the axial electron temperature. Present analysis may be useful for the analysis of quantum dots, the laser induced fusion and etc.

scholarly journals Magnetisation Processes in Geometrically Frustrated Spin Networks with Self-Assembled Cliques

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 336 ◽  
Author(s):  
Bosiljka Tadić ◽  
Miroslav Andjelković ◽  
Milovan Šuvakov ◽  
Geoff J. Rodgers
Keyword(s):  
Domain Walls ◽  
Spin Dynamics ◽  
Higher Order ◽  
Spin Networks ◽  
Graph Theoretic ◽  
Geometrically Frustrated ◽  
Geometric Frustration ◽  
Antiferromagnetic Materials ◽  
Geometrically Constrained ◽  
Ferromagnetic Interactions

Functional designs of nanostructured materials seek to exploit the potential of complex morphologies and disorder. In this context, the spin dynamics in disordered antiferromagnetic materials present a significant challenge due to induced geometric frustration. Here we analyse the processes of magnetisation reversal driven by an external field in generalised spin networks with higher-order connectivity and antiferromagnetic defects. Using the model in (Tadić et al. Arxiv:1912.02433), we grow nanonetworks with geometrically constrained self-assemblies of simplexes (cliques) of a given size n, and with probability p each simplex possesses a defect edge affecting its binding, leading to a tree-like pattern of defects. The Ising spins are attached to vertices and have ferromagnetic interactions, while antiferromagnetic couplings apply between pairs of spins along each defect edge. Thus, a defect edge induces n − 2 frustrated triangles per n-clique participating in a larger-scale complex. We determine several topological, entropic, and graph-theoretic measures to characterise the structures of these assemblies. Further, we show how the sizes of simplexes building the aggregates with a given pattern of defects affects the magnetisation curves, the length of the domain walls and the shape of the hysteresis loop. The hysteresis shows a sequence of plateaus of fractional magnetisation and multiscale fluctuations in the passage between them. For fully antiferromagnetic interactions, the loop splits into two parts only in mono-disperse assemblies of cliques consisting of an odd number of vertices n. At the same time, remnant magnetisation occurs when n is even, and in poly-disperse assemblies of cliques in the range n ∈ [ 2 , 10 ] . These results shed light on spin dynamics in complex nanomagnetic assemblies in which geometric frustration arises in the interplay of higher-order connectivity and antiferromagnetic interactions.

scholarly journals Metabolic evolution and the self-organization of ecosystems

2017 ◽  
Vol 114 (15) ◽  
pp. E3091-E3100 ◽  
Author(s):  
Rogier Braakman ◽  
Michael J. Follows ◽  
Sallie W. Chisholm
Keyword(s):  
Organic Carbon ◽  
Metabolic Rate ◽  
Light Adaptation ◽  
Atmospheric Oxygen ◽  
Heterotrophic Bacterium ◽  
The Self ◽  
Self Organization ◽  
Steady Increase ◽  
Mathematical Framework ◽  
Metabolic Evolution

Metabolism mediates the flow of matter and energy through the biosphere. We examined how metabolic evolution shapes ecosystems by reconstructing it in the globally abundant oceanic phytoplankterProchlorococcus. To understand what drove observed evolutionary patterns, we interpreted them in the context of its population dynamics, growth rate, and light adaptation, and the size and macromolecular and elemental composition of cells. This multilevel view suggests that, over the course of evolution, there was a steady increase inProchlorococcus’ metabolic rate and excretion of organic carbon. We derived a mathematical framework that suggests these adaptations lower the minimal subsistence nutrient concentration of cells, which results in a drawdown of nutrients in oceanic surface waters. This, in turn, increases total ecosystem biomass and promotes the coevolution of all cells in the ecosystem. Additional reconstructions suggest thatProchlorococcusand the dominant cooccurring heterotrophic bacterium SAR11 form a coevolved mutualism that maximizes their collective metabolic rate by recycling organic carbon through complementary excretion and uptake pathways. Moreover, the metabolic codependencies ofProchlorococcusand SAR11 are highly similar to those of chloroplasts and mitochondria within plant cells. These observations lead us to propose a general theory relating metabolic evolution to the self-amplification and self-organization of the biosphere. We discuss the implications of this framework for the evolution of Earth’s biogeochemical cycles and the rise of atmospheric oxygen.

scholarly journals Ultralow Power Dual-Gated Subthreshold Oxide Neuristors: An Enabler for Higher Order Neuronal Temporal Correlations

ACS Nano ◽  
2018 ◽  
Vol 12 (11) ◽  
pp. 11263-11273 ◽  
Author(s):  
Rohit Abraham John ◽  
Nidhi Tiwari ◽  
Chen Yaoyi ◽  
Ankit ◽  
Naveen Tiwari ◽  
...  
Keyword(s):  
Higher Order ◽  
Temporal Correlations ◽  
Ultralow Power

scholarly journals THE SELF-ORGANIZED MULTI-LATTICE MONTE CARLO SIMULATION

2004 ◽  
Vol 15 (09) ◽  
pp. 1249-1268 ◽  
Author(s):  
DENIS HORVÁTH ◽  
MARTIN GMITRA
Keyword(s):  
Monte Carlo ◽  
Finite Size ◽  
Simulation Method ◽  
Monte Carlo Step ◽  
The Self ◽  
Square Lattice ◽  
Critical Systems ◽  
Lattice Systems ◽  
Steady Regime ◽  
Self Organized

Self-organized Monte Carlo simulations of 2D Ising ferromagnet on the square lattice are performed. The essence of the suggested simulation method is an artificial dynamics consisting of the well-known single-spin-flip Metropolis algorithm supplemented by a random walk on the temperature axis. The walk is biased towards the critical region through a feedback based on instantaneous energy and magnetization cumulants, which are updated at every Monte Carlo step and filtered through a special recursion algorithm. The simulations revealed the invariance of the temperature probability distribution function, once some self-organized critical steady regime is reached, which is called here noncanonical equilibrium. The mean value of this distribution approximates the pseudocritical temperature of canonical equilibrium. In order to suppress finite-size effects, the self-organized approach is extended to multi-lattice systems, where the feedback basis on pairs of instantaneous estimates of the fourth-order magnetization cumulant on two systems of different size. These replica-based simulations resemble, in Monte Carlo lattice systems, some of the invariant statistical distributions of standard self-organized critical systems.

scholarly journals Network organizations: The structural arrangement behind new organizational forms

1995 ◽  
Vol 26 (3) ◽  
pp. 97-107
Author(s):  
José L. Alvarez ◽  
M. Anton Ferreira
Keyword(s):  
Driving Forces ◽  
Social Systems ◽  
Organizational Structures ◽  
Organizational Forms ◽  
Network Organization ◽  
Business Systems ◽  
Structural Arrangement ◽  
New Organizational Forms ◽  
Four Levels ◽  
Concept Network

This article elaborates the main meanings of the concept 'network organization' and the underlying structural arrangement behind most of the new organizational forms and the main alternative to the still dominant bureaucratic organizational structure. The concept is applied to four levels of analysis: macro economic and business systems; inter-organizational collaborative arrangements; intra-organizational structures; and informal intra-organizational social systems. Through this taxonomy, an attempt is made to disentangle the different meanings of the concept 'network organization'. Throughout, we seek to highlight the main variables that managers should take into account when making decisions and conducting operations in networks. The article commences with a brief historical overview of the evolution of organizational forms and the driving forces behind current development in the field.

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