Fissure filling is a treatment that improves the apparent clarity of a gemstone by removing air and replacing it with a substance that has a refractive index similar to the host material. Many different substances may be used to fill fissures: oils, resins, waxes, glass, and various polymers, to name a few.
Cerebral autoregulation is a process in mammals, which aims to maintain adequate and stable cerebral blood flow.hile most systems of the body show some degree of autoregulation, the brain is very sensitive to over-and underperfusion. Cerebral autoregulation plays an important role in maintaining an appropriate blood flow to that region.
The Limbic System. Â­When we look more closely at the areas of the brain involved with laughter, the limbic system seems to be central. The limbic system is a network of structures loÂ­cated beneath the cerebral cortex. This system is important because it controls some behaviors that are essential to the life of all mammals (finding food, self-preservation). Interestingly, the same structures found in the human limbic system can also be found in the brains of evolutionary ancient animals such as the alligator.