This happens about 2-3% of the time in people with celiac disease and can lead to false-negative test results. Common tests for celiac disease include: 1  Anti-tissue transglutaminase antibody (anti-tTG), IgA: detects antibodies to tissue transglutaminase, an enzyme that causes the crosslinking of certain proteins. 2  Anti-tTG, IgA is the most sensitive and specific blood test for celiac disease.
A contour line is a line drawn on a topographic map to indicate ground elevation or depression. A contour interval is the vertical distance or difference in elevation between contour lines. Index contours are bold or thicker lines that appear at every fifth contour line.
The standard contour interval on weather maps is 4 mb, which is easily divided by two or four. The most commonly seen heavy contours are 1000 mb, usually encircling lows, and 1024 mb, usually encircling highs. There are upper-air maps for pressures of 850 mb, 700 mb, 500 mb and 250 mb.