Retin-A (tretinoin) is a form of vitamin A that helps the skin renew itself. The Retin-A and Avita brands of tretinoin are used to treat acne. The Renova brand of tretinoin is used to reduce the appearance of fine wrinkles and mottled skin discoloration, and to make rough facial skin feel smoother. Retin-A may also be used for purposes not listed in this medication guide.
Waste Stream. The total flow of solid waste from homes, businesses, institutions, and manufacturing plants that is recycled, burned, or disposed of in landfills, or segments thereof such as the residential waste stream or the recyclable waste stream..
Recurring (intermittent) streams have water in the channel for at least part of the year. A stream of the first order is a stream which does not have any other recurring or perennial stream feeding into it.When two first-order streams come together, they form a second-order stream. stream is a body of water with a current, confined within a bed and stream banks.