Thyroid hormones which causes the thyroid to enlarge (the resulting medical condition is called "endemic colloid goitre"; see goitre). This has the effect of increasing the thyroid's ability to trap more iodide, compensating for the iodine deficiency and allowing it to produce adequate amounts of thyroid hormone. Most of the thyroid hormone circulating in the blood is bound to "transport protein"s. Only a very small fraction of the circulating hormone is free (unbound) and biologically active, hence measuring concentrations of free thyroid hormones is of great diagnostic value. When thyroid hormone is bound, it is not active, so the amount of free
Trace field of a representation algebra formula_12 is then as simple as possible, more precisely: The algebra formula_12 is called the quaternion algebra of formula_4. The quaternion algebra of formula_7 is called the "invariant quaternion algebra" of formula_4, denoted by formula_24. As for trace fields, the former is not the same for all groups in the same commensurability class but the latter is. If formula_4 is an arithmetic Fuchsian group then formula_26 and formula_24 together are a number field and quaternion algebra from which a group commensurable to formula_4 may be derived. The theory for Kleinian groups (discrete subgroups of formula_29) is mostly similar as