1 Why the test is used: Between 75% and 90% of people with lupus have a positive anti-dsDNA test. 2  Also, the test is very specific for lupus. 3  Therefore, a positive test can be useful in confirming a diagnosis. 4  For many people, the titer, or level, of the antibodies rises as the disease becomes more active.
The zone below ground where the pore spaces are filled with ground water is called the saturated zone. Above the saturated zone, where the pore spaces are not filled with ground water, is the unsaturated zone. The water table marks the boundary between the saturated and unsaturated zone. The water table intersects Earth's surface at rivers and at lakes.
How Much of the Earth is Covered with Water? About 70% of the earthâs surface is covered with water. Ninety-seven percent of the water on the earth is salt water. Salt water is filled with salt and other minerals, and humans cannot drink this water. Although the salt can be removed, it is a difficult and expensive process. Two percent of the water on earth is glacier ice at the North and South Poles.