Stimulus diffusion is a type of expansion diffusion in which the idea is acceptable or adopted but not in its original form and expanded to culturally acceptable.
For example :
1. Mc. Donalds is also in India but not in beef. Indians culture will not accept beef and so it is with different forms like veg, non veg but the idea is same.
2. Yoga is an idea where in different regions use yoga for different reasons but the idea is same.
The HIV virus continuously invades and destroys T-cells (lymphocytes). Eventually the body can't replace the T-cells fast enough, and the immune system deteriorates. When the immune system has deteriorated to the point that it is unable to fight off diseases, a person is diagnosed with AIDS.
An electric arc is a visible plasma discharge between two electrodes that is caused by electrical current ionizing gasses in the air. Electric arcs occur in nature in the form of lightning.