Agkistrodon piscivorus is a venomous snake, a species of pit viper, found in the southeastern United States. Adults are large and capable of delivering a painful and potentially fatal bite. When antagonized, they will stand their ground by coiling their bodies and displaying their fangs. Although their aggression has been exaggerated, individuals may bite when feeling threatened or being handled. This is the world's only semiaquatic viper, usually found in or near water, particularly in slow-moving and shallow lakes, streams, and marshes. The snake is a strong swimmer and will even enter the sea. It has successfully colonized islands off both the Atlantic and Gulf coasts.
The generic name is derived from the Greek words ancistro (hooked) and odon (tooth), and the specific name comes from the Latin piscis (fish) and voro (to eat); thus, the scientific name translates into “hooked-tooth fish-eater”. Common names include variants on water moccasin, swamp moccasin, black moccasin, cottonmouth, gapper, or simply viper. Many of the common names refer to the threat display, where this species will often stand its ground and gape at an intruder, exposing the white lining of its mouth. Three subspecies are currently recognized, including the nominate subspecies described here. Its diet consists mainly of fish and frogs but is otherwise highly varied and, uniquely, has even been reported to include carrion.
Congo is a 2001 BBC nature documentary series for television on the natural history of the Congo River of Central Africa. In three episodes, the series explores the variety of animals and habitats that are to be found along the river’s 4,700 km (2,922 mi) reach.
Congo was produced for the BBC Natural History Unit and the Discovery Channel by Scorer Associates. The series writer/producer was Brian Leith and the executive producer was Neil Nightingale. Series consultants were Michael Fay, Kate Abernethy, Jonathan Kingdon and Lee White.
Little filming was possible in the Democratic Republic of the Congo which encompasses the vast majority of the river's watershed. (The one exception to this is the brief sequence of Livingstone Falls.) The reason for this is that the Second Congo War (1998–2003) was underway during filming (1999–2000).
The series forms part of the Natural History Unit's Continents strand and was preceded by Andes to Amazon in 2000 and succeeded by Wild Africa later that year in 2001.
Congo (1954–1964) was a chimpanzee who learned how to draw and paint. Zoologist and surrealist painter Desmond Morris first observed his abilities when the chimp was offered a pencil and paper at two years of age. By the age of four, Congo had made 400 drawings and paintings. His style has been described as "lyrical abstract impressionism".
Congo was born in 1954. He learned to draw near the age of two, beginning when zoologist Desmond Morris offered Congo a pencil. Morris said, "He took Pencil and I placed a piece of card in front of him. This is how I recorded it at the time, 'Something strange was coming out of the end of the pencil. It was Congo's first line. It wandered a short way and then stopped. Would it happen again? Yes, it did, and again and again'." Morris soon observed that the chimp would draw circles, and had a basic sense of composition in his drawings. He also showed the ability of symmetrical consistency between two sides of a sketch; when Morris drew a shape at one side of a piece of paper, Congo would balance the structure by making marks on the other half of the paper. Similarly, if a color on one side contained blue for example, he would add blue to the other side as well to keep balance.
A top is a toy designed to be spun rapidly on the ground, the motion of which causes it to remain precisely balanced on its tip because of inertia. Such toys have existed since antiquity. Traditionally tops were constructed of wood, sometimes with an iron tip, and would be set in motion by aid of a string or rope coiled around its axis which, when pulled quickly, caused a rapid unwinding that would set the top in motion. Today they are often built of plastic, and modern materials and manufacturing processes allow tops to be constructed with such precise balance that they can be set in motion by a simple twist of the fingers and twirl of the wrist without need for string or rope.
The motion of a top is produced in the most simple forms by twirling the stem using the fingers. More sophisticated tops are spun by holding the axis firmly while pulling a string or twisting a stick or pushing an auger. In the kinds with an auger, an internal weight rotates, producing an overall circular motion. Some tops can be thrown, while firmly grasping a string that had been tightly wound around the stem, and the centrifugal force generated by the unwinding motion of the string will set them spinning upon touching ground.
A top is clothing that covers at least the chest, but which usually covers most of the upper human body between the neck and the waistline. The bottom of tops can be as short as mid-torso, or as long as mid-thigh. Men's tops are generally paired with pants, and women's with pants or skirts. Common types of tops are t-shirts, blouses and shirts.
The neckline is the highest line of the top, and may be as high as a head-covering hood, or as low as the waistline or bottom hem of the top. A top may be worn loose or tight around the bust or waist, and may have sleeves or shoulder straps, spaghetti straps (noodle straps), or may be strapless. The back may be covered or bare. Tops may have straps around the waist or neck, or over the shoulders.
In mathematics, the category of topological spaces, often denoted Top, is the category whose objects are topological spaces and whose morphisms are continuous maps or some other variant; for example, objects are often assumed to be compactly generated. This is a category because the composition of two continuous maps is again continuous. The study of Top and of properties of topological spaces using the techniques of category theory is known as categorical topology.
N.B. Some authors use the name Top for the category with topological manifolds as objects and continuous maps as morphisms.
Like many categories, the category Top is a concrete category (also known as a construct), meaning its objects are sets with additional structure (i.e. topologies) and its morphisms are functions preserving this structure. There is a natural forgetful functor
to the category of sets which assigns to each topological space the underlying set and to each continuous map the underlying function.