Abteilung Biophysik, Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg, D-39106 Magdeburg, Germany.
Phys Biol. 2013 Apr;10(2):026003. doi: 10.1088/1478-3975/10/2/026003. Epub 2013 Feb 13.
The plasmodium of the slime mould Physarum polycephalum forms a transportation network of veins, in which protoplasm is transported due to peristaltic pumping. This network forms a planar, weighted, undirected graph that, for the first time, can be extracted automatically from photographs or movies. Thus, data from real transportation networks have now become available for the investigation of network properties. We determine the local drag of the vein segments and use these data to calculate the transport efficiency. We unravel which veins form the backbone of the transportation network by using a centrality measure from graph theory. The principal vein segments lie on relatively ample cycles of veins, and the most important segments are those that belong simultaneously to two of these principal cycles. Each principal cycle contains a series of smaller cycles of veins of lower transport efficiency, thus reflecting the hierarchical and self-similar structure of the transportation network. Finally, we calculate accessibility maps that show how easily different nodes of the network may be reached from a given reference node.
多头绒泡菌的疟原虫形成了一个血管输送网络，其中原生质由于蠕动泵送而被输送。这个网络形成了一个平面的、加权的、无向的图，它可以首次从照片或电影中自动提取。因此，现在可以获得真实输送网络的数据来研究网络特性。我们确定了血管段的局部阻力，并使用这些数据来计算输送效率。我们使用图论中的中心性度量来揭示哪些血管构成了输送网络的主干。主要的血管段位于相对宽裕的血管环上，最重要的段是那些同时属于两个主要循环的段。每个主要循环都包含一系列较低输送效率的较小血管环，从而反映了输送网络的分层和自相似结构。最后，我们计算了可达性图，显示了网络的不同节点从给定参考节点到达的难易程度。
