Urodynamic testing or urodynamics is a study that assesses how the bladder and urethra are performing their job of storing and releasing urine. Urodynamic tests can help explain symptoms such as:
Some mixtures give rise to the reddish and purplish fall colors of trees such as dogwoods and sumacs, while others give the sugar maple its brilliant orange. The autumn foliage of some trees show only yellow colors. Others, like many oaks, display mostly browns. All these colors are due to the mixing of varying amounts of the chlorophyll residue and other pigments in the leaf during the fall season.
The tans and browns of oaks are caused by tannins which accumulate as the chlorophyll disappears. Fall color starts in September with poison ivy and sumac and ends in November with the larches and weeping willows. Frost and freezing temperatures will stop the coloration process and blacken the leaves. Source: Barbara Larson, Extension Educator, Horticulture. Morton Arboretum: Why Leaves Change Color.