Renal Replacement Therapy (RRT) Overview. Overview of RRT. Renal replacement therapy (RRT) is required when the kidneys are functioning at less than 10â15 percent. Dialysis. People with advanced chronic renal failure (CRF), kidney failure, who have progressed to end-stage renal disease (ESRD) usually require dialysis.
Rods are maximally sensitive to wavelengths near 500 nm, and play little, if any, role in colour vision. In brighter light, such as daylight, vision is photopic: light is detected by cone cells which are responsible for colour vision.
Determine the type of scales. Female cones have two types of scales: bract and seed or ovuliferous scales. Bract scales are modified leaves and develop first, earlier on in spring or summer; seed scales develop later and cover the bract scales to protect the ovules, which will develop into pine seeds.