Allometric Scaling Laws in the Exploratory Behavior of the Physarum Plasmodium

2012 ◽  
Vol 3 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Tomohiro Shirakawa
Keyword(s):  
Adaptive Behavior ◽  
Exploratory Behavior ◽  
Physarum Polycephalum ◽  
Cytoplasmic Streaming ◽  
Scaling Laws ◽  
Allometric Scaling ◽  
Tubular Structure ◽  
Plasmodium Of Physarum Polycephalum

The plasmodium of Physarum polycephalum is a unicellular and multinuclear giant amoeba. In this paper, the authors investigate four allometric laws in the exploratory behavior of the plasmodium, and integrate them into one schema based on the dynamics of cytoplasmic streaming. This study reveals a novel function of the tubular structure of the plasmodium, shedding new light on the adaptive behavior of the organism.

DEVELOPING PROXIMITY GRAPHS BY PHYSARUM POLYCEPHALUM: DOES THE PLASMODIUM FOLLOW THE TOUSSAINT HIERARCHY?

2009 ◽  
Vol 19 (01) ◽  
pp. 105-127 ◽  
Author(s):  
ANDREW ADAMATZKY
Keyword(s):  
Foraging Behavior ◽  
Delaunay Triangulation ◽  
Spanning Tree ◽  
Physarum Polycephalum ◽  
Minimum Spanning Tree ◽  
Nearest Neighbour ◽  
Minimal Spanning Tree ◽  
Proximity Graphs ◽  
Relative Neighborhood Graph ◽  
Plasmodium Of Physarum Polycephalum

Plasmodium of Physarum polycephalum spans sources of nutrients and constructs varieties of protoplasmic networks during its foraging behavior. When the plasmodium is placed on a substrate populated with sources of nutrients, it spans the sources with protoplasmic network. The plasmodium optimizes the network to deliver efficiently the nutrients to all parts of its body. How exactly does the protoplasmic network unfold during the plasmodium's foraging behavior? What types of proximity graphs are approximated by the network? Does the plasmodium construct a minimal spanning tree first and then add additional protoplasmic veins to increase reliability and through-capacity of the network? We analyze a possibility that the plasmodium constructs a series of proximity graphs: nearest-neighbour graph (NNG), minimum spanning tree (MST), relative neighborhood graph (RNG), Gabriel graph (GG) and Delaunay triangulation (DT). The graphs can be arranged in the inclusion hierarchy (Toussaint hierarchy): NNG ⊆ MST ⊆ RNG ⊆ GG ⊆ DT . We aim to verify if graphs, where nodes are sources of nutrients and edges are protoplasmic tubes, appear in the development of the plasmodium in the order NNG → MST → RNG → GG → DT , corresponding to inclusion of the proximity graphs.

scholarly journals On the Internalisation, Intraplasmodial Carriage and Excretion of Metallic Nanoparticles in the Slime Mould, Physarum Polycephalum

2011 ◽  
Vol 3 (3) ◽  
pp. 1-14 ◽  
Author(s):  
Richard Mayne ◽  
David Patton ◽  
Ben de Lacy Costello ◽  
Andrew Adamatzky ◽  
Rosemary Camilla Patton
Keyword(s):  
Metallic Nanoparticles ◽  
Physarum Polycephalum ◽  
Nutrient Concentration ◽  
Laboratory Experiments ◽  
Micro Scale ◽  
Naked Eye ◽  
High Nutrient ◽  
High Nutrient Concentration ◽  
Silver Metal ◽  
Plasmodium Of Physarum Polycephalum

The plasmodium of Physarum polycephalum is a large single cell visible with the naked eye. When inoculated on a substrate with attractants and repellents the plasmodium develops optimal networks of protoplasmic tubes which span sites of attractants (i.e. nutrients) yet avoid domains with a high nutrient concentration. It should therefore be possible to program the plasmodium towards deterministic adaptive transformation of internalised nano- and micro-scale materials. In laboratory experiments with magnetite nanoparticles and glass micro-spheres coated with silver metal the authors demonstrate that the plasmodium of P. polycephalum can propagate the nano-scale objects using a number of distinct mechanisms including endocytosis, transcytosis and dragging. The results of the authors’ experiments could be used in the development of novel techniques targeted towards the growth of metallised biological wires and hybrid nano- and micro-circuits.

scholarly journals A gene encoding the major beta tubulin of the mitotic spindle in Physarum polycephalum plasmodia.

1988 ◽  
Vol 8 (3) ◽  
pp. 1275-1281 ◽  
Author(s):  
T G Burland ◽  
E C Paul ◽  
M Oetliker ◽  
W F Dove
Keyword(s):  
Mitotic Spindle ◽  
Physarum Polycephalum ◽  
Fruit Fly ◽  
Beta Tubulin ◽  
Gene Encoding ◽  
Neutral Drift ◽  
Beta 2 ◽  
Restricted Use ◽  
Microtubular Organelles ◽  
Plasmodium Of Physarum Polycephalum

The multinucleate plasmodium of Physarum polycephalum is unusual among eucaryotic cells in that it uses tubulins only in mitotic-spindle microtubules; cytoskeletal, flagellar, and centriolar microtubules are absent in this cell type. We have identified a beta-tubulin cDNA clone, beta 105, which is shown to correspond to the transcript of the betC beta-tubulin locus and to encode beta 2 tubulin, the beta tubulin expressed specifically in the plasmodium and used exclusively in the mitotic spindle. Physarum amoebae utilize tubulins in the cytoskeleton, centrioles, and flagella, in addition to the mitotic spindle. Sequence analysis shows that beta 2 tubulin is only 83% identical to the two beta tubulins expressed in amoebae. This compares with 70 to 83% identity between Physarum beta 2 tubulin and the beta tubulins of yeasts, fungi, alga, trypanosome, fruit fly, chicken, and mouse. On the other hand, Physarum beta 2 tubulin is no more similar to, for example, Aspergillus beta tubulins than it is to those of Drosophila melanogaster or mammals. Several eucaryotes express at least one widely diverged beta tubulin as well as one or more beta tubulins that conform more closely to a consensus beta-tubulin sequence. We suggest that beta-tubulins diverge more when their expression pattern is restricted, especially when this restriction results in their use in fewer functions. This divergence among beta tubulins could have resulted through neutral drift. For example, exclusive use of Physarum beta 2 tubulin in the spindle may have allowed more amino acid substitutions than would be functionally tolerable in the beta tubulins that are utilized in multiple microtubular organelles. Alternatively, restricted use of beta tubulins may allow positive selection to operate more freely to refine beta-tubulin function.

Non-invasive assessment of allometric scaling laws in the human coronary tree

2010 ◽  
Vol 5 (1) ◽  
pp. 15 ◽  
Author(s):  
Damian Craiem ◽  
Mariano E. Casciaro ◽  
Sebastian Graf ◽  
Enrique P. Gurfinkel ◽  
Ricardo L. Armentano
Keyword(s):  
Scaling Laws ◽  
Allometric Scaling ◽  
Non Invasive
Sign in / Sign up

Export Citation Format

Share Document