1 You have signs of infection, such as: 2  Increased pain, swelling, warmth, or redness around the bite. 3  Red streaks leading from the bite. 4  Pus draining from the bite.  A fever.
A negative index of refraction due to three-dimensional chirality is demonstrated for abilayered metamaterial based on pairs of mutually twisted planar metal patterns in parallel planes, which alsoshows negative electric and magnetic responses and exceptionally strong optical activity and circular dichro-ism.
Optical Density and Refractive Index A transparent medium is sometimes said to have a high optical density (or to be relatively dense) if it has a high refractive index. For example, one may say that total internal reflection is possible only if the beam comes from the optically more dense medium.