scholarly journals Self-organized biotectonics of termite nests

2021 ◽  
Vol 118 (5) ◽  
pp. e2006985118
Author(s):  
Alexander Heyde ◽  
Lijie Guo ◽  
Christian Jost ◽  
Guy Theraulaz ◽  
L. Mahadevan
Keyword(s):  
Collective Action ◽  
Minimal Model ◽  
Nest Architecture ◽  
Governing Equations ◽  
Spatiotemporal Evolution ◽  
Self Organized ◽  
Building Behavior ◽  
Collective Building ◽  
Hydrodynamic Fields ◽  
Termite Nest

The termite nest is one of the architectural wonders of the living world, built by the collective action of workers in a colony. Each nest has several characteristic structural motifs that allow for efficient ventilation, cooling, and traversal. We use tomography to quantify the nest architecture of the African termite Apicotermes lamani, consisting of regularly spaced floors connected by scattered linear and helicoidal ramps. To understand how these elaborate structures are built and arranged, we formulate a minimal model for the spatiotemporal evolution of three hydrodynamic fields—mud, termites, and pheromones—linking environmental physics to collective building behavior using simple local rules based on experimental observations. We find that floors and ramps emerge as solutions of the governing equations, with statistics consistent with observations of A. lamani nests. Our study demonstrates how a local self-reinforcing biotectonic scheme is capable of generating an architecture that is simultaneously adaptable and functional, and likely to be relevant for a range of other animal-built structures.

scholarly journals AN EXPERIMENTAL COLLECTIVE INTELLIGENCE RESEARCH TOOL

2014 ◽  
pp. 40-50
Author(s):  
Bei Wang ◽  
Dung Hoang ◽  
Idris Daiz ◽  
Chiedu Okpala ◽  
Tarek M. Sobh
Keyword(s):  
Collective Behavior ◽  
Collective Intelligence ◽  
Research Tool ◽  
Research Implementation ◽  
Self Organized ◽  
Experimental Software ◽  
Efficient Alternative ◽  
Building Behavior ◽  
Alternative Research ◽  
Software And Hardware

The Collective Intelligence Research Tool (CIRT) is an experimental software and hardware research tool. It provides an inexpensive and efficient alternative research implementation that demonstrates simulations of the collective behavior of self-organized systems, primarily social insects. The software focuses on 2D simulations of the woodchip-collecting behavior of termites and 3D simulations of the building behavior of wasps. The hardware simulation employs a Boe-Bot robot, which has the potential of simulating simple movements of a social insect, by extending its functionality through adding sensors and integrating a control chip.

scholarly journals Pandemic makers: Emergent networks of collective entrepreneurship in response to crisis

2021 ◽  
Author(s):  
Russell Browder ◽  
Angela Forgues ◽  
Stella Seyb ◽  
Howard Aldrich
Keyword(s):  
Collective Action ◽  
Resource Constraints ◽  
Learned Resourcefulness ◽  
Local Networks ◽  
Self Organized ◽  
Collective Entrepreneurship ◽  
Multiple Case ◽  
Entrepreneurial Action ◽  
Emergent Networks

In response to COVID-19 and the shortage of personal protective equipment, the maker community activated local networks in a display of collective action. We conducted a multiple case study of emergent networks to understand how makers self-organized for collective entrepreneurial action while facing resource constraints and legitimacy deficits. Although the maker community has endeavored to break free from institutional constraints, they nonetheless formed relationships with institutions in need. They deployed learned resourcefulness and learned legitimation strategies with varying degrees of effectiveness. Our findings contribute to the literature on resourcefulness, legitimation, and collective action in entrepreneurship processes.

Nonviolent Communal Strategies in Insurgencies Case Study on Afghanistan

2019 ◽  
pp. 203-226
Author(s):  
Christoph Zürcher
Keyword(s):  
Rural Communities ◽  
Collective Action ◽  
Survey Data ◽  
Armed Groups ◽  
Self Organized ◽  
Self Defense ◽  
External Actors

In insurgencies, rural communities are the most vulnerable segment of society. Rural communities in Afghanistan are traditionally highly self-organized and capable of collective action. It is therefore reasonable to assume that communities will make collective efforts to minimize the risks of getting harmed. Using qualitative and survey data, this chapter investigates this proposition and shows that three strategies are often used and believed by respondents to be effective: negotiating with armed groups, neutrality, and self-defense. It describes these strategies and highlights the conditions under which they may be more or less effective. It then discusses how external actors can inadvertently reduce the space for such civil actions and make communities less safe, and what can be done to avoid this.

scholarly journals Who Needs the Experts? The Politics and Practices of Alternative Humanitarianism and Its Relationship to NGOs

2021 ◽  
Author(s):  
Armine Ishkanian ◽  
Isabel Shutes
Keyword(s):  
Collective Action ◽  
Recent Literature ◽  
Self Organized ◽  
Migration Crisis

AbstractDrawing on fieldwork in Greece, we examine the politics and practices of autonomous volunteering in the context of the migration crisis. This involves individuals engaging in activities to support migrants through non-registered, self-organized and self-governed groups that work independent from and in some cases, even in opposition to NGOs. We consider autonomous volunteering as a form of collective action and argue that it constitutes an alternative humanitarianism. While recent literature has sought to identify the rise of emergent practices of alternative humanitarianism in Europe, research has often overlooked how autonomous volunteers distinguish themselves from, relate to and collaborate with NGOs and conversely, how NGOs view and engage with them. We found that despite their critiques of NGOs and their determination to work independently, there were instances of cooperation between autonomous volunteers and NGOs. These interactions did not become substantive alliances, as the work of NGOs and autonomous volunteers continued to be disconnected from each other.

Protesting Youth

2017 ◽  
Vol 225 (4) ◽  
pp. 336-346 ◽  
Author(s):  
Jacquelien van Stekelenburg ◽  
Bert Klandermans
Keyword(s):  
Collective Action ◽  
News Media ◽  
Crucial Role ◽  
Significant Others ◽  
Contentious Politics ◽  
Social Embeddedness ◽  
Highly Educated ◽  
Self Organized ◽  
Connective Action

Abstract. “Twitter protests” and “Facebook revolutions” imbue the coverage of contentious politics in news media and academic outlets alike. As long as such protests are not compared to conventional mobilized events it is hard to ascertain the supposed differences between connective and collective action. We report a study that does just that: we examine if it makes a difference whether people are recruited through self-organized rather than organization-centered routes. We surveyed participants and nonparticipants in both actions (N = 319), asking who participated in the respective action, how they were mobilized, and why they participated. Results reveal that in some ways the recruitment route does make a difference, while in others it doesn’t. Recruits of connective action were lower educated, felt politically efficacious, and mainly mobilized via informal (virtual) mobilizing channels, while recruits of collective action were highly educated, politically interested, and mainly mobilized via formal mobilizing channels. Social embeddedness played a crucial role in both campaigns, but more so in self-organized actions: approving networks increase the chances of being asked, influenced, and motivated by significant others, while disapproving milieus decrease the chance of being asked, influenced, and motivated by others. Approving networks thus expand informal mobilization, the more so for self-organized connective action.

scholarly journals Modeling the mechanobioelectricity of cell clusters

2020 ◽  
Author(s):  
Alessandro Leronni
Keyword(s):  
Water Pressure ◽  
Polymer Network ◽  
Growth Dynamics ◽  
Governing Equations ◽  
Spatiotemporal Evolution ◽  
Finite Strain Theory ◽  
Electro Osmosis ◽  
A Cell ◽  
Compressible Hyperelasticity ◽  
Water And Ion Transport

Abstract We propose a continuum finite strain theory for the interplay between the bioelectricity and the poromechanics of a cell cluster. Specifically, we refer to a cluster of closely packed cells, whose mechanics is governed by a polymer network of cytoskeletal filaments joined by anchoring junctions, modeled through compressible hyperelasticity. The cluster is saturated with a solution of water and ions. We account for water and ion transport in the intercellular spaces, between cells through gap junctions, and across cell membranes through aquaporins and ion channels. Water fluxes result from the contributions due to osmosis, electro-osmosis, and water pressure, while ion fluxes encompass electro-diffusive and convective terms. We consider both the cases of permeable and impermeable cluster boundary, the latter simulating the presence of sealing tight junctions. We solve the coupled governing equations for a one-dimensional axisymmetric benchmark through finite elements, thus determining the spatiotemporal evolution of the intracellular and extracellular ion concentrations, setting the membrane potential, and water concentrations, establishing the cluster deformation. When suitably complemented with genetic, biochemical, and growth dynamics, we expect this model to become a useful instrument for investigating specific aspects of developmental mechanobioelectricity.

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