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Visualizing a Fischer projection. In chemistry, the Fischer projection, devised by Emil Fischer in 1891, is a two-dimensional representation of a three-dimensional organic molecule by projection. Fischer projections were originally proposed for the depiction of carbohydrates and used by chemists, particularly in organic chemistry and biochemistry.
Fischer–Tropsch process. The Fischer–Tropsch process (FT) is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen, known as syngas, into liquid hydrocarbons. These reactions occur in the presence of metal catalysts, typically at temperatures of 150–300 °C (302–572 °F) and pressures of one to ...
Common kingfisher. The common kingfisher ( Alcedo atthis ), also known as the Eurasian kingfisher and river kingfisher, is a small kingfisher with seven subspecies recognized within its wide distribution across Eurasia and North Africa. It is resident in much of its range, but migrates from areas where rivers freeze in winter.
Fisher information. In mathematical statistics, the Fisher information (sometimes simply called information [1]) is a way of measuring the amount of information that an observable random variable X carries about an unknown parameter θ of a distribution that models X. Formally, it is the variance of the score, or the expected value of the ...
Fishing nets have been used widely in the past, including by stone age societies. The oldest known fishing net is the net of Antrea, found with other fishing equipment in the Karelian town of Antrea, Finland, in 1913. The net was made from willow, and dates back to 8300 BC. [1] Recently, fishing net sinkers from 27,000 BC were discovered in ...
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions. Large-scale commercial fishing is called ...
Large predator fish with higher trophic levels have been depleted in wild fisheries. As a result, the fishing industry has been systematically "fishing down the food web", targeting fish species at progressively decreasing trophic levels. The trophic level of a fish is the position it occupies on the food chain.
Grouper. Groupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes . Not all serranids are called "groupers"; the family also includes the sea basses. The common name "grouper" is usually given to fish in one of two large genera: Epinephelus and Mycteroperca.