After a pregnancy of about 100 days the female gives birth to usually 1 - 4 babies. The young leave their family after 1–2 years, and they become mature at about 3 years. Jaguars can live up to 10–12 years old in freedom, but in captivity (such as in zoos) they can live to 20–22 years old.
Cheetah
A cheetah ("Acinonyx jubatus") is a medium large cat which lives in Africa. It is the fastest land animal and can run up to 112 kilometers per hour for a short time. Most cheetahs live in the savannas of Africa. There are a few in Asia. Cheetahs are active during the day, and hunt in the early morning or late evening.
The cheetah compared to other big cats is light and slimly built. Its long thin legs and long spotted tail are necessary for fast running. Its lightly built, thin form is in sharp contrast with the robust build of other big cats. The head-and-body length ranges from . The cheetah stands 70 to 90 cm at the shoulder, and weighs .
The slightly curved claws are only weakly retractable (semi-retractable). This is a major point of difference between the cheetah and the other big cats, which have fully retractable claws.
Cheetahs are active during the day, and hunt in the early morning or late evening. Cheetahs are carnivores. They prey on antelope, wildebeest, zebras, warthogs, hares, birds, rodents, snakes, fish, lizards and even jackals.
When the cheetah hunts, it slowly and secretly moves toward its prey. When it is close to the prey (about 10–30 meters), it runs after it very quickly. Cheetahs kill their prey by tripping it during the chase. To kill medium- to large-sized prey, the cheetah bites the prey's throat to suffocate it to death. A bite on the back of the neck or the snout is enough to kill smaller prey.
The cheetah cannot defend itself against lions or hyenas who would take the cheetah's prey away. The prey is taken to a shaded place. The cheetah, exhausted after the chase, rests beside the kill and pants heavily for some time. Once they recover, cheetahs eat fast, and consume large quantities as soon as they can.
Pregnant females give birth to about 3 to 5 cubs or kittens after three months pregnancy. It takes two years of full-time supervision by the mother before the cubs are ready to live independent lives. They need to learn how to catch prey, and that takes time. The young are vulnerable to larger predators: lions especially try to kill cheetahs.
The cheetah has unusually low genetic variability and a very low sperm count. Their sperms also suffer from deformed flagellae, and so their movement is damaged. Apparently, cheetahs went through a great reduction in numbers during the last ice age. Inbreeding after the event further reduced the variation (genetic drift).
Due to the fact that cheetah never attack and kill humans it was extremely popular as a hunting pet since antiquity and especially in medieval times in the Near and Middle East.
In the modern times cheetah probably is the most difficult to have as a pet among wild cats, due to necessity of wide open spaces for cheetah to run with the full speed for they proper development. And especially it's very important to feed them properly, because cheetah in captivity have to be fed only lean steamed meat so cheetah don't get sick and perish.
The cheetah is the fastest of the land dwellers.
The acceleration of a cheetah allows it to reach speeds of up to hundreds of kilometers per hour in three seconds (its maximum speed is 112 kilometers per hour). The speed that a cheetah can develop from the start in 3 seconds cannot be achieved by any sports racing car.
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Quartz
Quartz is a tectosilicate mineral that is the second most common mineral in Earth's continental crust. Its crystal structure is a framework of SiO silicon–oxygen tetrahedra. Each shares an oxygen atom with another tetrahedron, so the overall chemical formula is SiO or silica.
There are many different varieties of quartz, some of which are semi-precious gemstones. They have been used for a long time to make jewelry and hardstone carvings. Agate, amethyst, rose quartz are all forms of quartz.
Quartz crystals are used in oscillators, for example in quartz clocks. People also extract the silicon to make semiconductors.
The majority of sand is small quartz bits. Quartz has a mineral hardness of 7. (mohs scale).
The word "quartz" comes from the German word "quarz".
'Fused quartz' is glass made of silica in non-crystalline form. It does not contain other ingredients that are added to other glass to lower the melting point. Fused silica has high working and melting temperatures. For some purposes, fused quartz is better than other types of glass due to its purity. The glass is used in a number of high-tech products.
Shocked quartz is a form of quartz that has a microscopic structure different from normal quartz. Under intense pressure (but limited temperature), the crystalline structure of quartz is deformed along planes inside the crystal. These planes show up as lines under a microscope.
Shocked quartz is found worldwide, especially in impact craters and in the thin Cretaceous–Paleogene boundary layer. This is at the contact between Cretaceous and Paleogene rocks. It is further evidence (in addition to iridium enrichment) that the transition between the two geologic periods was caused by a large impact. Eugene Shoemaker discovered it in building stones in the Bavarian town of Nördlingen. The stones were from shocked metamorphic rocks, such as breccia, of a meteor crater.
Pink Floyd
Pink Floyd were an English rock band that became famous in the 1960s and 1970s. They performed for more than 30 years, and have sold more than 200 million (200,000,000) albums. They are famous for their live shows and deep music. Most of their albums are concept albums, which means every song is linked through a theme. Their first album was "The Piper at the Gates of Dawn", which was released in 1967. Their latest album is "The Endless River", which was released in November 2014. The band were named after the blues artists "Pink Anderson" and "Floyd Council" by Syd Barrett, one of the band's founder members. In 2005, they played at a concert called Live Aid after 24 years of not playing together. The line up was David Gilmour, Roger Waters, Nick Mason and Richard Wright. They have made some very popular albums including "The Dark Side of the Moon," which was released in 1973 and "The Wall," which was released in 1979. After Richard Wright died in 2008, David Gilmour has said that he does not want to reunite, despite Roger saying he might want to. It is now believed that David Gilmour and Roger Waters are friends after becoming enemies for a long time.
Syd Barrett started the group, and played guitar and sang in the band. He left soon after, at the start of 1968, because of a mental illness that was made worse by heavy drug use. The other people in the band were Roger Waters (bass guitar and vocals), David Gilmour (lead guitar and vocals), Richard Wright (keyboard and vocals), and Nick Mason (drums). David Gilmour joined the band in 1968. Roger Waters quit the band in 1985.
During most of their career, they played a kind of rock music that some people call "progressive rock".
The original members of Pink Floyd met in an architectural college. The band started as a blues band. Later, under Syd Barrett's leadership, they played music that was psychedelic in style. After Barrett left the band, they started to play longer and more complicated songs, and to play at a lot of colleges and universities. Soon, they were famous as studio musicians who loved to experiment with music. On the album "Atom Heart Mother", from 1970, they used a brass band and a choir.