AGRICULTURE |
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Agriculture (a term which encompasses farming) is the art, science or practice of producing food, feed, fiber and many other desired goods by the systematic raising of plants and animals. Agri is from Latin ager ("a field"), and culture is from Latin cultura, meaning "cultivation" in the strict sense of tillage of the soil. Thus a literal reading of the English word yields tillage of the soil of a field. In actual usage, Agriculture denotes a broad array of activities essential to food and material production, including all techniques for raising and processing livestock (see Animal husbandry) no less than those essential to crop planting and harvesting.
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CANCER - GENERAL |
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Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis. This unregulated growth is caused by damage to DNA, resulting in mutations to genes that encode for proteins controlling cell division. Many mutation events may be required to transform a normal cell into a malignant cell. These mutations can be caused by chemicals or physical agents called carcinogens, by close exposure to radioactive materials, or by certain viruses that can insert their DNA into the human genome. Mutations occur spontaneously, or are passed down generations as a result of germ line mutations.
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COASTAL WETLANDS |
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In physical geography, a wetland is an environment "at the interface between truly terrestrial ecosystems...and truly aquatic systems...making them different from each yet highly dependent on both" (Mitsch & Gosselink, 1986). In essence, wetlands are ecotones.
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FISHERIES |
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A fishery (plural: fisheries) is an organized effort by humans to catch fish or other aquatic species, an activity known as fishing. Generally, a fishery exists for the purpose of providing human food, although other aims are possible (such as sport or recreational fishing), or obtaining ornamental fish or fish products such as fish oil. Industrial fisheries are fisheries where the catch is not intended for direct human consumption (Castro and Huber 2003).
Regardless of purpose, however, the term fishery generally refers to a fishing effort centered on either a particular ecoregion or a particular species or type of fish or aquatic animal, and usually fisheries are differentiated by both criteria. Examples would be the salmon fishery of Alaska, the cod fishery off the Lofoten islands or the tuna fishery of the Eastern Pacific. Most fisheries are marine, rather than freshwater; most marine fisheries are based near the coast. This is not only because harvesting from relatively shallow waters is easier than in the open ocean, but also because fish are much more abundant near the coastal shelf, due to coastal upwelling and the abundance of nutrients available there.
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HYDROLOGY |
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Hydrology (from Greek: Yδρoλoγια, Yδωρ+Λoγos, Hydrologia, the "study of water") is the study of the movement, distribution, and quality of water throughout the Earth, and thus addresses both the hydrologic cycle and water resources. A practitioner of hydrology is a hydrologist, working within the fields of either earth or environmental science, or civil and environmental engineering.
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POLLUTION |
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Pollution is the release of environmental contaminants. Carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), and nitrogen oxides produced by industry and motor vehicles are common air pollutants. Sunlight converts nitrogen oxides and hydrocarbons to ozone or smog. Water pollutants may consist of a wide range of organic and inorganic chemicals such as heavy metals, petrochemicals, chloroform, and bacteria. Water pollution may also occur in the form of thermal pollution and dissolved oxygen depletion. Soil contamination is an important aspect of environmental pollution; this phenomenon occurs when chemicals are released by spill or underground storage tank leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE, herbicides, pesticides and chlorinated hydrocarbons. The U.S., Russia, China and Japan are the world leaders in air pollution emissions; however, Canada is the number two country on a per capita basis.
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