skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Functional Interdependence in Coupled Dissipative Structures: Physical Foundations of Biological Coordination
Coordination within and between organisms is one of the most complex abilities of living systems, requiring the concerted regulation of many physiological constituents, and this complexity can be particularly difficult to explain by appealing to physics. A valuable framework for understanding biological coordination is the coordinative structure, a self-organized assembly of physiological elements that collectively performs a specific function. Coordinative structures are characterized by three properties: (1) multiple coupled components, (2) soft-assembly, and (3) functional organization. Coordinative structures have been hypothesized to be specific instantiations of dissipative structures, non-equilibrium, self-organized, physical systems exhibiting complex pattern formation in structure and behaviors. We pursued this hypothesis by testing for these three properties of coordinative structures in an electrically-driven dissipative structure. Our system demonstrates dynamic reorganization in response to functional perturbation, a behavior of coordinative structures called reciprocal compensation. Reciprocal compensation is corroborated by a dynamical systems model of the underlying physics. This coordinated activity of the system appears to derive from the system’s intrinsic end-directed behavior to maximize the rate of entropy production. The paper includes three primary components: (1) empirical data on emergent coordinated phenomena in a physical system, (2) computational simulations of this physical system, and (3) theoretical evaluation of the empirical and simulated results in the context of physics and the life sciences. This study reveals similarities between an electrically-driven dissipative structure that exhibits end-directed behavior and the goal-oriented behaviors of more complex living systems.  more » « less
Award ID(s):
1735225
PAR ID:
10280755
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Entropy
Volume:
23
Issue:
5
ISSN:
1099-4300
Page Range / eLocation ID:
614
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; ; ; et al (, Science)
    null (Ed.)
    The structural and functional complexity of multicellular biological systems, such as the brain, are beyond the reach of human design or assembly capabilities. Cells in living organisms may be recruited to construct synthetic materials or structures if treated as anatomically defined compartments for specific chemistry, harnessing biology for the assembly of complex functional structures. By integrating engineered-enzyme targeting and polymer chemistry, we genetically instructed specific living neurons to guide chemical synthesis of electrically functional (conductive or insulating) polymers at the plasma membrane. Electrophysiological and behavioral analyses confirmed that rationally designed, genetically targeted assembly of functional polymers not only preserved neuronal viability but also achieved remodeling of membrane properties and modulated cell type–specific behaviors in freely moving animals. This approach may enable the creation of diverse, complex, and functional structures and materials within living systems. 
    more » « less
  2. ; (, IEEE)
    The design of autonomous, dynamically selfassembled robots that perform collective motion at the microscale can help in advancing the fundamental principles of self-assembly and coordinated behavior of complex structures. Here, we discuss the dissipative collective dynamics of soft colloidal micro-rotators driven by magnetic rotating fields with different orientation. The micro-rotators were polydimethylsiloxane microbeads with internally aligned magnetic nanoparticle chains, which respond to the torque created by rotating magnetic fields. The dynamic assembly patterns and their collective motion when actuated by in-plane and by transversal rotating fields were characterized. In all cases, we observed a rich variety of new modes of collective dynamics of the micro-rotor ensembles. We categorized these dynamics into three different types including caterpillar motion and cartwheel motion in case of a transverse-plane rotating field and gear-like motion in case of an in-plane field. The influence of field parameters such as rotational speed was studied. These fascinating dynamic patterns and motility modes could find application in future microrobots operating in complex biological fluids. 
    more » « less
  3. ; ; ; ; ; ; (, Soft Matter)
    Recently, the study of long, slender living worms has gained attention due to their unique ability to form highly entangled physical structures, exhibiting emergent behaviors. These organisms can assemble into an active three-dimensional soft entity referred to as the “blob”, which exhibits both solid-like and liquid-like properties. This blob can respond to external stimuli such as light, to move or change shape. In this perspective article, we acknowledge the extensive and rich history of polymer physics, while illustrating how these living worms provide a fascinating experimental platform for investigating the physics of active, polymer-like entities. The combination of activity, long aspect ratio, and entanglement in these worms gives rise to a diverse range of emergent behaviors. By understanding the intricate dynamics of the worm blob, we could potentially stimulate further research into the behavior of entangled active polymers, and guide the advancement of synthetic topological active matter and bioinspired tangling soft robot collectives. 
    more » « less
  4. ; (, Chemistry – A European Journal)
    Abstract Nature‐inspired synthetic dissipative self‐assemblies have attracted much attention recently. However, it remains a major challenge to achieve precise control over dissipative supramolecular assembly structures and functions of self‐contained systems. Here we combine light and electricity as two clean, and spatiotemporally addressable fuels to provide precise control over the morphology for dissipative self‐assembly of a perylene bisimide glycine (PBIg) building block in a self‐contained solution. In this design, electrochemical oxidation provides the positive fuel to activate PBIg self‐assembly while photoreduction supplies the negative fuel to deactivate the system for disassembly. Through programming the two counteracting fuels, we demonstrated the control of PBIg self‐assembly into a variety of assembly morphologies in a self‐contained system. In addition, by exerting light and electrical dual fuels simultaneously, we could create an active homeostasis exhibiting dynamic instability, leading to morphological change to asymmetric assemblies with curvatures. Such precise control over self‐assembly of self‐contained systems may find future applications in programming complex active materials as well as formulating pharmaceutical reagents with desired morphologies. 
    more » « less
  5. ; ; ; ; ; (, Proceedings of the National Academy of Sciences)
    The seemingly straightforward task of tying one’s shoes requires a sophisticated interplay of joints, muscles, and neural pathways, posing a formidable challenge for researchers studying the intricacies of coordination. A widely accepted framework for measuring coordinated behavior is the Haken–Kelso–Bunz (HKB) model. However, a significant limitation of this model is its lack of accounting for the diverse variability structures inherent in the coordinated systems it frequently models. Variability is a pervasive phenomenon across various biological and physical systems, and it changes in healthy adults, older adults, and pathological populations. Here, we show, both empirically and with simulations, that manipulating the variability in coordinated movements significantly impacts the ability to change coordination patterns—a fundamental feature of the HKB model. Our results demonstrate that synchronized bimanual coordination, mirroring a state of healthy variability, instigates earlier transitions of coordinated movements compared to other variability conditions. This suggests a heightened adaptability when movements possess a healthy variability. We anticipate our study to show the necessity of adapting the HKB model to encompass variability, particularly in predictive applications such as neuroimaging, cognition, skill development, biomechanics, and beyond. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email