Events and activities of the Earth and its structures.

Diamond. A crystalline form of carbon that occurs as hard, colorless or tinted isomeric crystals. It is used as a precious stone, for cutting glass, and as bearings for delicate mechanisms. (From Grant & Hackh's Chemical Dictionary, 5th ed)

Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.

A state in southeastern Australia. Its capital is Sydney. It was discovered by Captain Cook in 1770 and first settled at Botany Bay by marines and convicts in 1788. It was named by Captain Cook who thought its coastline resembled that of South Wales. (From Webster's New Geographical Dictionary, 1988, p840 & Room, Brewer's Dictionary of Names, 1992, p377)

Salts or ions of the theoretical carbonic acid, containing the radical CO2(3-). Carbonates are readily decomposed by acids. The carbonates of the alkali metals are water-soluble; all others are insoluble. (From Grant & Hackh's Chemical Dictionary, 5th ed)

Tools used in dentistry that operate at high rotation speeds.

A trace element with the atomic symbol B, atomic number 5, and atomic weight [10.806; 10.821]. Boron-10, an isotope of boron, is used as a neutron absorber in BORON NEUTRON CAPTURE THERAPY.

The ash, dust, gases, and lava released by volcanic explosion. The gases are volatile matter composed principally of about 90% water vapor, and carbon dioxide, sulfur dioxide, hydrogen, carbon monoxide, and nitrogen. The ash or dust is pyroclastic ejecta and lava is molten extrusive material consisting mainly of magnesium silicate. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Hard, amorphous, brittle, inorganic, usually transparent, polymerous silicate of basic oxides, usually potassium or sodium. It is used in the form of hard sheets, vessels, tubing, fibers, ceramics, beads, etc.

Literary and oral genre expressing meaning via symbolism and following formal or informal patterns.

Method of measuring and mapping the scope of vision, from central to peripheral of each eye.

An autonomous region located in central Asia, within China.

Inland bodies of still or slowly moving FRESH WATER or salt water, larger than a pond, and supplied by RIVERS and streams.

Dissertations embodying results of original research and especially substantiating a specific view, e.g., substantial papers written by candidates for an academic degree under the individual direction of a professor or papers written by undergraduates desirous of achieving honors or distinction.

Water containing no significant amounts of salts, such as water from RIVERS and LAKES.

A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)

A country spanning from central Asia to the Pacific Ocean.

The sixth planet in order from the sun. It is one of the five outer planets of the solar system. Its twelve natural satellites include Phoebe and Titan.

A plant family of the order Pinales, class Pinopsida, division Coniferophyta (conifers). They are mainly resinous, aromatic evergreen trees.

Restraining belts fastened to the frame of automobiles, aircraft, or other vehicles, and strapped around the person occupying the seat in the car or plane, intended to prevent the person from being thrown forward or out of the vehicle in case of sudden deceleration.

A body of water covering approximately one-fifth of the total ocean area of the earth, extending amidst Africa in the west, Australia in the east, Asia in the north, and Antarctica in the south. Including the Red Sea and the Persian Gulf, it constitutes the third largest ocean after the ATLANTIC OCEAN and the PACIFIC OCEAN. (New Encyclopaedia Britannica Micropaedia, 15th ed, 1990, p289)

Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.

Computer-based representation of physical systems and phenomena such as chemical processes.

A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)

A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.

Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.

Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.

A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals and causes visceral leishmaniasis (LEISHMANIASIS, VISCERAL). The sandfly genera Phlebotomus and Lutzomyia are the vectors.

A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)

A product of hard secondary xylem composed of CELLULOSE, hemicellulose, and LIGNANS, that is under the bark of trees and shrubs. It is used in construction and as a source of CHARCOAL and many other products.

Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.

Medical complexes consisting of medical school, hospitals, clinics, libraries, administrative facilities, etc.

The ability to recognize when information is needed and to locate, evaluate, and use the needed information effectively.

The study of natural phenomena by observation, measurement, and experimentation.