It rises in the Valdai Hills of Russia, 225m above sea level north-west of Moscow. The Kama, Oka, Vetluga and the Sura are its main tributaries. The Volga and its tributaries form the Volga river system, which drains an area of about 1.35 million square kilometres in Russia. The Volga Delta has a length of about 160 kilometres. It includes
555 channels and small streams. It is the largest estuary in Europe. It is the only place in Russia where pelicans, flamingoes, and lotuses may be found. The Volga freezes for most of its length for three months each year. Some of the biggest reservoirs in the world can be found along the river.
Oi!
Oi! is a type of punk rock that was started in the United Kingdom in the late 1970s. The people that started it wanted to connect punk with a working class street-level following. Oi! is a mixing of the styles of early punk bands, such as The Clash, Sex Pistols and the Ramones. It is also influenced by early British rock bands (such as The Rolling Stones and The Who), football chants, pub rock and glam rock bands. The music is often very simple, and the lyrics are blunt (brutally honest, without tact).
Punk rock began to become popular in the 1970s. Some perceived that it was becoming more and more commercialised. This was the kind of thing that punks were against. Oi! began partly as a response to this perception. It was also partly a response to stereotyping that others made about punks. One stereotype was that many people in the early punk rock scene were young people using big words and trying to be artistic, but failing.
Early Oi! bands such as Sham 69 were around for years before the word "Oi!" was used to describe their style of music. The word was first used as a name for the new genre in 1980, by journalist Garry Bushell. He took the name from the way the Cockney Rejects used "Oi!" during live shows to introduce their songs. "Oi! Oi! Oi!" was the title of the third track on their second album. The word is an old Cockney expression, meaning "hey" or "hello". Other bands that were labelled as Oi! bands in the early days of the genre included Angelic Upstarts, The 4-Skins, The Business, Blitz, The Blood, and Combat 84. More recent punk bands such as Rancid and Dropkick Murphys have credited Oi! as a source of inspiration.
Brothers Grimm
The Brothers Grimm (German: "Die Brüder Grimm", also "Gebrüder Grimm") were the brothers Jakob and Wilhelm Grimm. They were German academics and most famous for their collections of folktales and fairy tales, and for their work in linguistics.
The Grimm brothers both became linguists. They are the inventors of German philology. They also did other language-related work, like publishing one of the first grammar books for the German language.
They also wrote fairy tales, and collected the tales which people told them. They published a collection of fairy tales known as "Grimms' Fairy Tales" ("Grimms Märchen").
Heavy metal
Heavy metal may mean:
Bryozoa
Bryozoans, also known as the Polyzoa, Ectoprocta or moss animals, are a phylum of small aquatic animals living in colonies. The colonies usually have a skeleton of calcium carbonate. Bryozoans have a long fossil history, starting in the Ordovician. In their life-style they resemble the polyps which form coral. They generally like warm, tropical waters but live all over the world. There are about 5,000 living species, and 15,000 fossil species are known.
The colonies are formed by tiny (~0.2mm) members called zooids. They secrete tubes, usually of lime (CaCO), sometimes of chitin, an organic compound. The zooids in a colony are all clones, produced by asexual reproduction. Despite this, most species produce different morphs: zooids with different functions.
All bryozoa have a lophophore. This is a ring of ten tentacles surrounding the mouth, each tentacle covered with cilia. When feeding, the zooid extends the lophophore outwards; when resting it is withdrawn into the mouth to protect it from predators.
Bryozoan skeletons grow in a variety of shapes and patterns: mound-shaped, lacy fans, branching twigs, and even corkscrew-shaped. Their skeletons have many tiny openings. Each opening is the home of "zooid". They have a body with a U-shaped gut, opening at the mouth and at the anus. They feed with their lophophore. The tentacles of the bryozoans are ciliated. The beating of the cilia creates a current of water which drives food (mainly phytoplankton) towards the mouth. In some groups, notably some ctenostomes, a gizzard may be formed.
Bryozoans do not have a respiratory, or a blood system, because their small size allows diffusion of gases and nutrients. However, they do have a simple nervous system, and muscles, which together can quickly take the zooid down into its shelter.
One species of bryozoan, "Bugula neritina", is of interest as a source of chemicals, bryostatins, which are under investigation as anti-cancer agents.
Bryozoans can reproduce both sexually and asexually. All Bryozoans, as far as is known, are hermaphrodite (meaning they are both male and female).
All members of a colony are clones: they are genetically identical, produced by asexual reproduction. This occurs by budding off new zooids from the first zooid. So the colony grows; this is the way a colony expands in size. If a piece of a bryozoan colony breaks off, the piece can continue to grow and will form a new colony.
All zooids in a colony are linked by strands of epithelial cells. The individual members of a colony, the zooids, are in some species generalised: they feed, and they can reproduce on occasion. But in most species the zooids are specialised to diffent functions. In this case the feeding zooids are called "autozooids", and the non-feeding members are called "heterozooids". Functions done by heterozooids include sexual reproduction, protection, locomotion, plumbing, structural support. The functions of some heterozooids is still unknown. The commonest function is that eggs are developed in brooding chambers ("ovicells") on female or hermaphrodite heterozooids. There are variations in the details: sometimes a little complex of heterozooids produce larvae in a cooperative effort.
Another way to describe the bryozoa which develop heterozooids is to say they are polymorphic. This term is used in biology to describe the way a genetically unified population develops into clearly distinct forms. The polymorphism is usually controlled by genetic switching mechanisms, but in bryozoa there is little knowledge of their genetics.
Most species of Bryozoan live in marine environments. There are about 50 species which inhabit freshwater. In their aquatic habitats, bryozoans live on all types of hard substrates: sand grains, rocks, shells, wood, blades of kelp, pipes and ships may be heavily encrusted with bryozoans. Some bryozoan colonies, however, do not grow on solid substrates, but form colonies on sediment. While some species live at depths of 8,200 m, most bryozoans live in much shallower water. Most bryozoans are sessile and immobile, but a few colonies are able to creep about, and a few species of non-colonial bryozoans live and move about in the spaces between sand grains. One remarkable species makes its living while floating in the Southern Ocean. Several bryozoan species live in the Midwestern United States, especially in Ohio, Indiana, and Kentucky which was once a part of a large ocean, the Western Interior Seaway.
Their diet consists of small microorganisms, including diatoms and other unicellular algae. In turn, bryozoans are preyed on by grazing organisms such as sea urchins and fish.