Coal forms from the accumulation of plant debris, usually in a swamp environment. When plant debris dies and falls into the swamp the standing water of the swamp protects it from decay. Swamp waters are usually deficient in oxygen, which would react with the plant debris and cause it to decay.
Porokeratosis is generally considered to be a benign condition though malignant transformation has been seen in all but the punctate variety, necessitating regular followup of patients with porokeratosis (Maubec et al., 2005; Sasson & Krain, 1996).
Benign Paroxysmal Positional Vertigo (BPPV) is the most common of vestibular disorders and the most easily treated. In most patients, it can be cured with a simple physical therapy maneuver. BPPV can affect people of all ages, although it is most common in folks over the age of 60.enign Paroxysmal Positional Vertigo (BPPV) is the most common of vestibular disorders and the most easily treated. In most patients, it can be cured with a simple physical therapy maneuver. BPPV can affect people of all ages, although it is most common in folks over the age of 60.