Branch Retinal Artery Occlusion - Pathophysiology. 1  Most commonly, a branch retinal artery occlusion occurs secondary to an embolus. Emboli typically originate within vessels upstream where they dislodge and travel within the circulatory system to ultimately become lodged downstream in a vessel with a smaller lumen.
Ragtime is a musical form or style that is defined as a syncopated melody (usually in 2/4 time) over a regular, march tempo bass line. Improvisation was common but little of that aspect has been preserved.
The genre has its origins in the red light districts of African-American communities in St. Louis years before being published as popular sheet music for piano. Ernest Hogan (1865â1909) was an pioneer of ragtime music and the first to publish in the musical genre.