Filamentous actin is polar and, therefore, the two ends of the filament are different. Because of this polarity, the filaments often fit into other cellular structures in only one orientation, in a similar manner to how many of the parts of man-made structures are assembled. Growth, the addition of monomeric actin to the filament, occurs predominantly in one direction; the plus direction.
Larger landscaping rocks, such as boulders, can cost upwards of $800 per ton. For example, a volcanic rock can cost $600 per ton, and an Artic white boulder can cost $150 per ton. Natural stone edging, ideal for gardens and walkways, can cost $200 to $600 per ton.
1 Spring lawn cleanups of a 1/3 to 1/2 acre lawn typically cost $200 to $500, not including extreme circumstances such as large tree removals or excessive water damage.2  Larger lawns of 1+ acres can easily exceed $1,000. 3  Removing a small lake or a large fallen tree from a property can easily double the total cleanup cost. Often times, however, companies will pro-rate a tree removal for rights to the wood (if of burnable quality). 2  Professional landscapers charge $30 to $50 per person, per hour. 3  An average crew consisting of 3 men will cost $90 to $150 per hour.