One of the most important standards that the API has set is the method used for measuring the density of petroleum. This standard is called the API gravity. Specific gravity is a ratio of the density of one substance to the density of a reference substance, usually water.
The most common symptoms of RSI include: 1  Pain. 2  Tingling. 3  A feeling of restlessness in the joint. 4  Weakness. 5  Throbbing. 6  Stiffness or cramp.
Symptoms of UTIs. Elderly people with serious urinary tract infection don't exhibit the hallmark sign of fever because their immune system is unable to mount a response to infection due to the effects of aging. In fact, elders often don't exhibit any of the common symptoms â or don't express them to their caregivers. UTIs in the elderly are often mistaken as the early stages of dementia or Alzheimer's, according to NIH, because symptoms include: 1  Confusion, or delirium-like state.  Agitation.