|  | 
         
          | Description: 
             This image shows nutrient 
            flow in a fungus. The yellow represents carbon, the red nitrogen, 
            and the blue phosphorus. The fungus ingests nutrients from its periphery 
            to its center and distributes the nutrients from its center to its 
            outer parts, creating a bottleneck at the center. |   
          | Source: 
             Mark Fricker, Oxford University |   
          | Story:  Traffic 
            model maps congestion TRN July 27/August 3, 2005
 |   
          | TRN Categories: 
             Physics; Networking |   
          | Form: 
             Still |  |