Of the common causes for exudative pleural effusions, parapneumonic effusions have the highest diagnostic priority. Even in the face of antibiotic therapy, infected pleural effusions can rapidly coagulate and organize to form fibrous peels that might require surgical decortication.
Retrogradation is the landward change in position of the front of a river delta with time.etrogradation is the landward change in position of the front of a river delta with time.
The term retrograde comes from the Latin word retrogradus, which literally means âbackward step.â. As the name suggests, retrograde is when a planet appears to go backward in its orbit, as viewed from Earth. Astronomers refer to this as âapparent retrograde motion,â because it is an optical illusion. The opposite of retrograde is direct or prograde motion.