Symbols as constraints

2009 ◽  
Vol 17 (3) ◽  
pp. 653-676 ◽  
Author(s):  
Joanna Raczaszek-Leonardi

The paper draws a parallel between natural language symbols and the symbolic mode in living systems. The inextricability of symbols and the dynamics with which they are functionally related shows that much of their structuring is due to dynamics and self-organization. It is also stressed that important factors that determine the shape of language structure lie outside individual mind/brains and they draw on time-scales quite different from those of phenomenological experience. Analysis of language into units and subsystems is thus not straightforward, since they show functionality on many levels and many time-scales. Finally it is recognized that, as a specific and specialized system of inter-individual coordination, natural language is many hierarchical levels away form simpler forms of information transmission in biological systems.

2016 ◽  
Vol 6 (1) ◽  
pp. 20150098 ◽  
Author(s):  
Markus J. Buehler ◽  
Guy M. Genin

Advances in multiscale models and computational power have enabled a broad toolset to predict how molecules, cells, tissues and organs behave and develop. A key theme in biological systems is the emergence of macroscale behaviour from collective behaviours across a range of length and timescales, and a key element of these models is therefore hierarchical simulation. However, this predictive capacity has far outstripped our ability to validate predictions experimentally, particularly when multiple hierarchical levels are involved. The state of the art represents careful integration of multiscale experiment and modelling, and yields not only validation, but also insights into deformation and relaxation mechanisms across scales. We present here a sampling of key results that highlight both challenges and opportunities for integrated multiscale experiment and modelling in biological systems.


2012 ◽  
Vol 102 (3) ◽  
pp. 505a
Author(s):  
Peter Salamon ◽  
Mariam Ghochani ◽  
James Nulton ◽  
Terrence G. Frey ◽  
Avinoam Rabinovitch ◽  
...  

2018 ◽  
Vol 5 (4) ◽  
pp. 110 ◽  
Author(s):  
Kazusa Beppu ◽  
Ziane Izri ◽  
Yusuke Maeda ◽  
Ryota Sakamoto

As expressed “God made the bulk; the surface was invented by the devil” by W. Pauli, the surface has remarkable properties because broken symmetry in surface alters the material properties. In biological systems, the smallest functional and structural unit, which has a functional bulk space enclosed by a thin interface, is a cell. Cells contain inner cytosolic soup in which genetic information stored in DNA can be expressed through transcription (TX) and translation (TL). The exploration of cell-sized confinement has been recently investigated by using micron-scale droplets and microfluidic devices. In the first part of this review article, we describe recent developments of cell-free bioreactors where bacterial TX-TL machinery and DNA are encapsulated in these cell-sized compartments. Since synthetic biology and microfluidics meet toward the bottom-up assembly of cell-free bioreactors, the interplay between cellular geometry and TX-TL advances better control of biological structure and dynamics in vitro system. Furthermore, biological systems that show self-organization in confined space are not limited to a single cell, but are also involved in the collective behavior of motile cells, named active matter. In the second part, we describe recent studies where collectively ordered patterns of active matter, from bacterial suspensions to active cytoskeleton, are self-organized. Since geometry and topology are vital concepts to understand the ordered phase of active matter, a microfluidic device with designed compartments allows one to explore geometric principles behind self-organization across the molecular scale to cellular scale. Finally, we discuss the future perspectives of a microfluidic approach to explore the further understanding of biological systems from geometric and topological aspects.


Author(s):  
Martin Nilsson ◽  
Steen Rasmussen

Realistic molecular dynamics and self-assembly is represented in a lattice simulation where water, water-hydrocarbons, and water-amphiphilic systems are investigated. The details of the phase separation dynamics and the constructive self-assembly dynamics are discussed and compared to the corresponding experimental systems. The method used to represent the different molecular types can easily be expended to include additional molecules and thus allow the assembly of more complex structures. This molecular dynamics (MD) lattice gas fills a modeling gap between traditional MD and lattice gas methods. Both molecular objects and force fields are represented by propagating information particles and all microscopic interactions are reversible. Living systems, perhaps the ultimate constructive dynamical systems, is the motivation for this work and our focus is a study of the dynamics of molecular self-assembly and self-organization. In living systems, matter is organized such that it spontaneously constructs intricate functionalities at all levels from the molecules up to the organism and beyond. At the lower levels of description, chemical reactions, molecular selfassembly and self-organization are the drivers of this complexity. We shall, in this chapter, demonstrate how molecular self-assembly and selforganization processes can be represented in formal systems. The formal systems are to be denned as a special kind of lattice gas and they are in a form where an obvious correspondence exists between the observables in the lattice gases and the experimentally observed properties in the molecular self-assembly systems. This has the clear advantage that by using these formal systems, theory, simulation, and experiment can be conducted in concert and can mutually support each other. However, a disadvantage also exists because analytical results are difficult to obtain for these formal systems due to their inherent complexity dictated by their necessary realism. The key to novelt simpler molecules (from lower levels), dynamical hierarchies are formed [2, 3]. Dynamical hierarchies are characterized by distinct observable functionalities at multiple levels of description. Since these higher-order structures are generated spontaneously due to the physico-chemical properties of their building blocks, complexity can come for free in molecular self-assembly systems. Through such processes, matter apparently can program itself into structures that constitute living systems [11, 27, 30].


Science ◽  
2011 ◽  
Vol 333 (6047) ◽  
pp. 1252-1254 ◽  
Author(s):  
Petra Schwille

How synthetic can “synthetic biology” be? A literal interpretation of the name of this new life science discipline invokes expectations of the systematic construction of biological systems with cells being built module by module—from the bottom up. But can this possibly be achieved, taking into account the enormous complexity and redundancy of living systems, which distinguish them quite remarkably from design features that characterize human inventions? There are several recent developments in biology, in tight conjunction with quantitative disciplines, that may bring this literal perspective into the realm of the possible. However, such bottom-up engineering requires tools that were originally designed by nature’s greatest tinkerer: evolution.


2000 ◽  
Vol 08 (02) ◽  
pp. 141-149 ◽  
Author(s):  
MICHEL CABANAC ◽  
MAURICIO RUSSEK

Control theory is concerned mainly with the treatment of signals. This article takes into account that living beings not only treat information, but they are open systems traversed by flows of energy and mass. A new block diagram of the regulation process is proposed, taking into account this fundamental difference between engineered and living systems. This new diagram possesses both didactic and heuristic advantages.


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