Epidemiology

A system using beamed and reflected radio signals to and from an object in such a way that range, bearing, and other characteristics of the object may be determined.

The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).,One sievert is the dose equivalent of radiation exposure imparted by ionizing X-RAY (roentgen rays) or other radiation undergoing an energy loss of 1 joule per kilogram of body tissue (l gray). One sievert is equivalent to 100 rem (roentgen equivalent in man).,One gray is equivalent to the radiation exposure that deposits one joule per kilogram of animal tissue or other material, or 100 rads.

A method for ordering genetic loci along CHROMOSOMES. The method involves fusing irradiated donor cells with host cells from another species. Following cell fusion, fragments of DNA from the irradiated cells become integrated into the chromosomes of the host cells. Molecular probing of DNA obtained from the fused cells is used to determine if two or more genetic loci are located within the same fragment of donor cell DNA.

The observation, either continuously or at intervals, of the levels of radiation in a given area, generally for the purpose of assuring that they have not exceeded prescribed amounts or, in case of radiation already present in the area, assuring that the levels have returned to those meeting acceptable safety standards.

Uncontrolled release of radioactive material from its containment. This either threatens to, or does, cause exposure to a radioactive hazard. Such an incident may occur accidentally or deliberately.,Accidental dispersal of radioactive materials from a radiation source. Accidents at nuclear reactors can involve large groups of the population from dispersion of radioactivity into the environment and through fallout or a few individuals with high injurious doses.

Radioimmunoassay of proteins using antibody coupled to an immunosorbent.

Health concerns associated with the effects of radiation on the environment and on public and personal health.

Information systems, usually computer-assisted, designed to store, manipulate, and retrieve information for planning, organizing, directing, and controlling administrative activities associated with the provision and utilization of radiology services and facilities.

Techniques used to determine the age of materials, based on the content and half-lives of the RADIOACTIVE ISOTOPES they contain.

The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.,A device used for detecting or measuring ionizing radiation by counting the resulting ionizing events.,A radiation counter that uses a radiation-counter tube, operated in the Geiger range, to detect and count ionizing particles. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)