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.
The saturated zone beneath the water table is called an aquifer, and aquifers are huge storehouses of water. What you are looking at in this picture is a well that exposes the water table, with an aquifer beneath it. Of course, I am cheating here, as at the beach, the level of the water table is always at the same level as the ocean, which is just below the surface of the beach.