Track

Track or Tracks may refer to:

Electronics and computing

Entertainment

Song

A song is a single (and often standalone) work of music intended to be sung by the human voice with distinct and fixed pitches and patterns using sound and silence and a variety of forms that often include the repetition of sections. Written words created specifically for music or for which music is specifically created, are called lyrics. If a pre-existing poem is set to composed music in classical music it is an art song. Songs that are sung on repeated pitches without distinct contours and patterns that rise and fall are called chants. Songs in a simple style that are learned informally are often referred to as folk songs. Songs that are composed for professional singers are called popular songs. These songs, which have broad appeal, are often composed by professional songwriters, composers and lyricists. Art songs are composed by trained classical composers for concert performances. Songs are performed live and recorded. Songs may also appear in plays, musical theatre, stage shows of any form, and within operas.

Track (rail transport)

The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, railroad ties (sleepers, British English) and ballast (or slab track), plus the underlying subgrade. It enables trains to move by providing a dependable surface for their wheels to roll. For clarity it is often referred to as railway track (British English and UIC terminology) or railroad track (predominantly in the United States). Tracks where electric trains or electric trams run are equipped with an electrification system such as an overhead electrical power line or an additional electrified rail.

The term permanent way also refers to the track in addition to lineside structures such as fences etc.

Structure

Traditional track structure

Notwithstanding modern technical developments, the overwhelmingly dominant track form worldwide consists of flat-bottom steel rails supported on timber or pre-stressed concrete sleepers, which are themselves laid on crushed stone ballast.

Leer

Leer is a town in the district of Leer, the northwestern part of Lower Saxony, Germany. It is situated on the river Leda, a tributary of the river Ems, near the border with the Netherlands.

It has a railway and autobahn connection to Groningen, Netherlands, Emden, Bremen and the South (Rheine and the Ruhrpott industrial region).

Geography

Leer had been a settlement long before it was first mentioned in written documents. Originally the city was situated at a meander near the mouth of the river Leda into the Ems, which is still the center of the town today. Even though Leer is some 30 km (19 mi) away from the coast, it can be reached by large ships via the Ems. Leer lies close to the Dutch border; the district of Leer shares a border with the Dutch province of Groningen.

History

County of East Frisia 1464–1744  Kingdom of Prussia 1744–1806
Kingdom of Holland 1806–1810
 First French Empire 1810–1813
 Kingdom of Prussia 1813–1815
 Kingdom of Hanover 1815–1866
 Kingdom of Prussia 1866–1871
 German Empire 1871–1918
 Weimar Republic 1918–1933
 Nazi Germany 1933–1945
 Allied-occupied Germany 1945–1949
 West Germany 1949–1990
 Germany 1990–present

Chimaera

Chimaeras are cartilaginous fishes in the order Chimaeriformes, known informally as ghost sharks, rat fish (not to be confused with the rattails), spookfish (not to be confused with the true spookfish of the family Opisthoproctidae), or rabbit fish (not to be confused with the true rabbitfishes of the family Siganidae).

At one time, a "diverse and abundant" group (based on the fossil record), their closest living relatives are sharks, though in evolutionary terms, they branched off from sharks nearly 400 million years ago and have remained isolated ever since. Today, they are largely confined to deep water.

Description and habits

Chimaeras live in temperate ocean floors down to 2,600 m (8,500 ft) deep, with few occurring at depths shallower than 200 m (660 ft). Exceptions include the members of the genus Callorhinchus, the rabbit fish and the spotted ratfish, which locally or periodically can be found at relatively shallow depths. Consequently, these are also among the few species from the Chimaera order kept in public aquaria. They have elongated, soft bodies, with a bulky head and a single gill-opening. They grow up to 150 cm (4.9 ft) in length, although this includes the lengthy tail found in some species. In many species, the snout is modified into an elongated sensory organ.

Graft-chimaera

In horticulture, a graft-chimaera may arise in grafting at the point of contact between rootstock and scion and will have properties intermediate between those of its "parents". A graft-chimaera is not a true hybrid but a mixture of cells, each with the genotype of one of its "parents": it is a chimaera. Hence, the once widely used term "graft-hybrid" is not descriptive; it is now frowned upon.

Propagation is by cloning only. In practice graft-chimaeras are not noted for their stability and may easily revert to one of the "parents".

Nomenclature

Article 21 of the ICNCP stipulates that a graft-chimaera can be indicated either by

Chimaera (Well of Echoes)

Chimaera is the fourth and final book in Ian Irvine's The Well of Echoes quartet.