Infrastructure means the basic structure of an organization or system. A company's infrastructure would include all the fixed assets, i.e., the building, equipment, machinery and tools required to manufacture their product. Although people are not fixed assets they would be included in the company's infrastructure too.
Rarely a serious problem. Look-alikes: Jumping oak gall, tubakia leaf spot, oak leaf blister, other fungal leaf spots. Jumping oak gall Brown leaves appear on trees in the white oak group in late spring. Severe infections may cause the leaves to turn black, curl up and fall. On the underside are brown galls with the larva of a small wasp inside.
Maple seeds do not fall off the tree until the wings are quite dry. This has two advantages. For one thing it makes them lighter so that they will fly farther. It also makes the wing more brittle so that once they land the wing material may break away from the seed.