Neodymium: Neodymium. An element of the rare earth family of metals. It has the atomic symbol Nd, atomic number 60, and atomic weight 144.24, and is used in industrial applications.Samarium: Samarium. An element of the rare earth family of metals. It has the atomic symbol Sm, atomic number 62, and atomic weight 150.36. The oxide is used in the control rods of some nuclear reactors.Rubidium: An element that is an alkali metal. It has an atomic symbol Rb, atomic number 37, and atomic weight 85.47. It is used as a chemical reagent and in the manufacture of photoelectric cells.Organophosphorus Compounds: Organic compounds that contain phosphorus as an integral part of the molecule. Included under this heading is broad array of synthetic compounds that are used as PESTICIDES and DRUGS.Radioisotopes: Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Organometallic Compounds: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)Isotopes: Atomic species differing in mass number but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.Evolution, Planetary: Creation and development of bodies within solar systems, includes study of early planetary geology.Geology: The science of the earth and other celestial bodies and their history as recorded in the rocks. It includes the study of geologic processes of an area such as rock formations, weathering and erosion, and sedimentation. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Geological Phenomena: The inanimate matter of Earth, the structures and properties of this matter, and the processes that affect it.Earth (Planet): Planet that is the third in order from the sun. It is one of the four inner or terrestrial planets of the SOLAR SYSTEM.Paleontology: The study of early forms of life through fossil remains.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Gills: Paired respiratory organs of fishes and some amphibians that are analogous to lungs. They are richly supplied with blood vessels by which oxygen and carbon dioxide are exchanged directly with the environment.Status Epilepticus: A prolonged seizure or seizures repeated frequently enough to prevent recovery between episodes occurring over a period of 20-30 minutes. The most common subtype is generalized tonic-clonic status epilepticus, a potentially fatal condition associated with neuronal injury and respiratory and metabolic dysfunction. Nonconvulsive forms include petit mal status and complex partial status, which may manifest as behavioral disturbances. Simple partial status epilepticus consists of persistent motor, sensory, or autonomic seizures that do not impair cognition (see also EPILEPSIA PARTIALIS CONTINUA). Subclinical status epilepticus generally refers to seizures occurring in an unresponsive or comatose individual in the absence of overt signs of seizure activity. (From N Engl J Med 1998 Apr 2;338(14):970-6; Neurologia 1997 Dec;12 Suppl 6:25-30)History, Ancient: The period of history before 500 of the common era.Greek World: A historical and cultural entity dispersed across a wide geographical area under the influence of Greek civilization, culture, and science. The Greek Empire extended from the Greek mainland and the Aegean islands from the 16th century B.C., to the Indus Valley in the 4th century under Alexander the Great, and to southern Italy and Sicily. Greek medicine began with Homeric and Aesculapian medicine and continued unbroken to Hippocrates (480-355 B.C.). The classic period of Greek medicine was 460-136 B.C. and the Graeco-Roman period, 156 B.C.-576 A.D. (From A. Castiglioni, A History of Medicine, 2d ed; from F. H. Garrison, An Introduction to the History of Medicine, 4th ed)Minerals: Native, inorganic or fossilized organic substances having a definite chemical composition and formed by inorganic reactions. They may occur as individual crystals or may be disseminated in some other mineral or rock. (Grant & Hackh's Chemical Dictionary, 5th ed; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Roman World: A historical and cultural entity dispersed across a wide geographical area under the political domination and influence of ancient Rome, bringing to the conquered people the Roman civilization and culture from 753 B.C. to the beginning of the imperial rule under Augustus in 27 B.C. The early city built on seven hills grew to conquer Sicily, Sardinia, Carthage, Gaul, Spain, Britain, Greece, Asia Minor, etc., and extended ultimately from Mesopotamia to the Atlantic. Roman medicine was almost entirely in Greek hands, but Rome, with its superior water system, remains a model of sanitation and hygiene. (From A. Castiglioni, A History of Medicine, 2d ed pp196-99; from F. H. Garrison, An Introduction to the History of Medicine, 4th ed, pp107-120)Textbooks as Topic: Books used in the study of a subject that contain a systematic presentation of the principles and vocabulary of a subject.Floods: Sudden onset water phenomena with different speed of occurrence. These include flash floods, seasonal river floods, and coastal floods, associated with CYCLONIC STORMS; TIDALWAVES; and storm surges.Faculty: The teaching staff and members of the administrative staff having academic rank in an educational institution.Judgment: The process of discovering or asserting an objective or intrinsic relation between two objects or concepts; a faculty or power that enables a person to make judgments; the process of bringing to light and asserting the implicit meaning of a concept; a critical evaluation of a person or situation.Documentaries and Factual FilmsScience: The study of natural phenomena by observation, measurement, and experimentation.Half-Life: The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.Pattern Recognition, Visual: Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Face: The anterior portion of the head that includes the skin, muscles, and structures of the forehead, eyes, nose, mouth, cheeks, and jaw.Biogenesis: The origin of life. It includes studies of the potential basis for life in organic compounds but excludes studies of the development of altered forms of life through mutation and natural selection, which is BIOLOGICAL EVOLUTION.Catalogs, LibraryPhysiognomy: An assessment of a person's personality based on their facial and other external features.Nobel PrizeCatalogs as Topic: Ordered compilations of item descriptions and sufficient information to afford access to them.Hydrothermal Vents: Hot springs on the ocean floor. They are commonly found near volcanically active places such as mid-oceanic ridges.Religion and ScienceReligious Philosophies: Sets of beliefs on the nature of the universe or Man.Therapeutic Misconception: Misunderstanding among individuals, frequently research subjects, of scientific methods such as randomization and placebo controls.Thinking: Mental activity, not predominantly perceptual, by which one apprehends some aspect of an object or situation based on past learning and experience.Educational Measurement: The assessing of academic or educational achievement. It includes all aspects of testing and test construction.Students: Individuals enrolled in a school or formal educational program.Famous PersonsPhysics: The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Health Physics: The science concerned with problems of radiation protection relevant to reducing or preventing radiation exposure, and the effects of ionizing radiation on humans and their environment.Radiation Oncology: A subspecialty of medical oncology and radiology concerned with the radiotherapy of cancer.Radiation ProtectionRadiometry: The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.Quality of Life: A generic concept reflecting concern with the modification and enhancement of life attributes, e.g., physical, political, moral and social environment; the overall condition of a human life.