What are some examples of natural hazards that can occur quickly with little or no warning?

What is a traditional chinese touch therapy involving finger pressure applied to specific areas of the body to restore the flow of qi.

What causes darkening of the skin as melanin production increases

The small molecule cyclic amp (camp) takes about 0.2 second to diffuse 10 μm, on average, in a cell. suppose that camp is produced near the plasma membrane on one end of the cell; how long will it take for this camp to diffuse through the cytosol and reach the opposite end of a very large cell, on average? assume that the cell is 200 μm in diameter.