Summary. 1  Algae are a necessary component of any healthy natural pond ecosystem. 2  However, excessive inputs of nutrients can lead to an overabundance of algae. 3  Excessive growth of filamentous algae, referred to as mats, moss, or scum, is one of the most common problems encountered by pond owners.
From Wikipedia, the free encyclopedia. The history of radiation therapy or radiotherapy can be traced back to experiments made soon after the discovery of x-rays (1895), when it was shown that exposure to radiation produced cutaneous burns.ases sprung up of the development of carcinoma in patients who had used conventional radium therapy up to 40 years after the original treatments. Robley D. Evans made the first measurements of exhaled radon and radium excretion from a former dial painter in 1933.
Sign in to receive recommendations (Learn more). Radiation therapy â also called radiotherapy â is a highly targeted and highly effective way to destroy cancer cells in the breast that may stick around after surgery. Radiation can reduce the risk of breast cancer recurrence by about 70%.Despite what many people fear, radiation therapy is relatively easy to tolerate and its side effects are limited to the treated area.adiation can reduce the risk of breast cancer recurrence by about 70%. Despite what many people fear, radiation therapy is relatively easy to tolerate and its side effects are limited to the treated area.