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.
Tweet. Share this. Radiotherapy or radiation therapy is the general term for the use of radiation in the treatment of disease. Radiotherapy uses ionizing radiation to kill harmful cells in the body. Ionizing radiation can come from many sources, such as x-rays, gamma rays, or proton beams.When used for cancer treatments, radiation kills cancerous cells and shrinks tumors.weet. Share this. Radiotherapy or radiation therapy is the general term for the use of radiation in the treatment of disease. Radiotherapy uses ionizing radiation to kill harmful cells in the body. Ionizing radiation can come from many sources, such as x-rays, gamma rays, or proton beams.