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fortification

(Encyclopedia)fortification, system of defense structures for protection from enemy attacks. Fortification developed along two general lines: permanent sites built in peacetime, and emplacements and obstacles hasti...

symbolic logic

(Encyclopedia)symbolic logic or mathematical logic, formalized system of deductive logic, employing abstract symbols for the various aspects of natural language. Symbolic logic draws on the concepts and techniques ...

Gorbachev, Mikhail Sergeyevich

(Encyclopedia)Gorbachev, Mikhail Sergeyevich mēkhəyēlˈ sĭrgāˈyəvich gərbəchofˈ ...

Ryukyu Islands

(Encyclopedia)Ryukyu Islands rēo͞oˈkyo͞o [key], Jap. Ryukyu-retto or Nansei-shoto [southwest group], archipelago (1990 est. pop. 1,500,000), c.1,850 sq mi (4,790 sq km), SW Japan, in the W Pacific Ocean. The ch...

Samoa, country, SW Pacific Ocean

(Encyclopedia)Samoa, formerly Western Samoa, officially Independent State of Samoa, constitutional monarchy (2015 est. pop. 194,000), South Pacific, comprising the western half of the Samoa island chain. There are ...

Aleutian Islands

(Encyclopedia)Aleutian Islands əlo͞oˈshən [key], chain of rugged, volcanic islands curving c.1,200 mi (1,900 km) west from the tip of the Alaska Peninsula and approaching Russia's Komandorski Islands. A partial...

DNA fingerprinting

(Encyclopedia)DNA fingerprinting or DNA profiling, any of several similar techniques for analyzing and comparing DNA from separate sources, used especially in law enforcement to identify suspects from hair, blood, ...

seafloor spreading

(Encyclopedia)CE5 Schematic model of the oceanic crust, showing seafloor spreading seafloor spreading, theory of lithospheric evolution that holds that the ocean floors are spreading outward from vast underwate...

crustacean

(Encyclopedia)CE5 Internal anatomy of a female crayfish, representative of the class Crustacea crustacean krŭstāˈshən [key], primarily aquatic arthropod of the subphylum Crustacea. Most of the 44,000 crusta...

genetic engineering

(Encyclopedia)CE5 Genetic engineering: Gene-splicing techniques genetic engineering, the use of various methods to manipulate the DNA (genetic material) of cells to change hereditary traits or produce biologica...