Varves form only in fresh or brackish water, because the high levels of salt in normal sea water coagulate the clay into coarse grains. Since the saline waters leave coarse particles all year, it is nearly impossible to distinguish the individual layers in salt waters.
An aspartate aminotransferase (AST) test measures the amount of this enzyme in the blood. AST is normally found in red blood cells, liver, heart, muscle tissue, pancreas, and kidneys. AST formerly was called serum glutamic oxaloacetic transaminase (SGOT). Low levels of AST are normally found in the blood. When body tissue or an organ such as the heart or liver is diseased or damaged, additional AST is released into the bloodstream. The amount of AST in the blood is directly related to the extent of the tissue damage.
Anemia is the most common cause of a low hematocrit result. Anemia occurs when the body has a below normal amount of red blood cells. This causes a hematocrit levels fall below normal. Malnutrition or nutritional deficiencies of certain vitamins or minerals can lead to anemia and produce low HCT blood test results.he value measures what percentage of red blood cells a blood sample contains. For example, a hematocrit 47% means that for every 100 mL of blood, 47 mL are red blood cells. The normal range for a male is between 40.7% and 50.3%. The normal range for a female is between 36.1% and 44.3%.