Class A (type D) CpG ODNs (CpG-A ODNs) contain a central palindromic phosphodiester (PO) CpG sequence and a PS-modified 3â poly-G tail. The poly G tails form intermolecular tetrads that result in high molecular weight ordered structures.
Why does a tornado form when cold and hot air meet? The collision of warm and cold air is not the direct cause of a tornado, nor is it absolutely necessary. When a cold air mass pushes into a warm air mass (this is called a câ¦old front) the warmer, less dense air is forced upwards.
Heat itself does not rise, but hot air does. The cycle of rising hot air and cool sinking air is what creates many weather phenomenon, such as tornadoes and hurricanes as well as everyday thunderstorms and breezes. With global warming, the warmer seas and ground will cause this cycle to become exacerbated.