Without variable valve timing or variable valve lift, the valve timing must be the same for all engine speeds and conditions, therefore compromises are necessary. An engine equipped with a variable valve timing actuation system is freed from this constraint, allowing performance to be improved over the engine operating range.
A variety of medical specialists treat people with osteoporosis, including internists, gynecologists, family doctors, endocrinologists, rheumatologists, physiatrists, orthopaedists, and geriatricians. There are a number of ways to find a doctor who treats osteoporosis patients. If you have a primary care or family doctor, discuss your concerns with him or her. Your doctor may treat the disease or be able to refer you to an osteoporosis specialist.
Depending on your particular symptoms, a diagnosis of scleroderma may be made by: 1  A general internist. 2  A dermatologist, who specializes in treating diseases of the skin, hair, and nails. 3  An orthopaedist, who treats bone and joint disorders.  A pulmonologist, who is trained to treat lung problems.