Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: Can cats control their purr?
One hypothesis, backed by electromyographic studies, is that cats produce the purring noise by using the vocal folds or the muscles of the larynx to alternately dilate and constrict the glottis rapidly, causing air vibrations during inhalation and exhalation. Combined with the steady inhalation and exhalation of air as the cat breathes, a purring noise is produced with strong harmonics.
Domestic cats have barbed penises, with about 120–150 one millimeter long backwards-pointing spines. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which is a trigger for ovulation. Lions also have barbed penises. Male felids urinate backwards by curving the tip of the glans penis backward. When male cheetahs urine-mark their territories, they stand one meter away from a tree or rock surface with the tail raised, pointing the penis either horizontally backward or 60° upward.
Cats have seven cervical vertebrae like almost all mammals, thirteen thoracic vertebrae (humans have twelve), seven lumbar vertebrae (humans have five), three sacral vertebrae (humans have five because of their bipedal posture), and, except for Manx cats and other shorter tailed cats, twenty-two or twenty-three caudal vertebrae (humans have three to five, fused into an internal coccyx). The extra lumbar and thoracic vertebrae account for the cat's enhanced spinal mobility and flexibility, compared to humans. The caudal vertebrae form the "tail", used by the cat as a counterbalance to the body during quick movements. Between their vertebrae, they have elastic discs, useful for cushioning the jump landings.
Cats is a 1998 direct-to-video musical film based on the stage musical "Cats" by Andrew Lloyd Webber, itself based on the novel "Old Possum's Book of Practical Cats" by T. S. Eliot. Lloyd Webber himself personally oversaw orchestration for the film and called on Gillian Lynne, the original show's choreographer, to personally train the cast for the film. Trevor Nunn, the original director, did not serve as the director of this production.
Lloyd Webber embarked on his next project without a lyricist, turning instead to the poetry of T. S. Eliot. "Cats" (1981) was to become the longest running musical in London, where it ran for 21 years before closing. On Broadway, "Cats" ran for 18 years, a record which would ultimately be broken by another Lloyd Webber musical, "The Phantom of the Opera".
The best-known musical adaptation of the poems is Andrew Lloyd Webber's musical "Cats", which was premiered in the West End of London in 1981 and on Broadway in 1982. It became the longest-running Broadway show in history until it was overtaken by another musical by Lloyd Webber, "The Phantom of the Opera", and then by "Chicago". As well as the characters found in the book, "Cats" introduces several additional characters from Eliot's unpublished drafts, most notably Grizabella. A film adaptation of "Cats" is due for release on December 20, 2019.
"Memory" is a show tune from the 1981 musical "Cats". It is sung by the character Grizabella, a one-time glamour cat who is now only a shell of her former self. The song is a nostalgic remembrance of her glorious past and a declaration of her wish to start a new life. Sung briefly in the first act and in full near the end of the show, "Memory" is the climax of the musical, and by far its most popular and best-known song. Elaine Paige originated the role of Grizabella in the West End production of "Cats", the first to perform the song publicly on stage and bringing attention to its writers Andrew Lloyd Webber and Trevor Nunn, who received the 1981 Ivor Novello award for Best Song Musically and Lyrically.
Cats in ancient Egypt were represented in social and religious practices of Ancient Egypt for more than 30 centuries. Several Ancient Egyptian deities were depicted and sculptured with cat-like heads such as Mafdet, Bastet and Sekhmet, representing justice, fertility and power.
The deity Mut was also depicted as a cat and in the company of a cat.
It was announced on 27 June 2014 that "Cats" will be returning to London from December 2014 for a 12-week run at the London Palladium following the UK national tour with the original creative team featuring direction from Trevor Nunn, choreography by Gillian Lynne and design by John Napier. The run was later extended through April 2015. Along with this Andrew Lloyd Webber would be rewriting a number of songs from the musical. Speaking on the revival, Lloyd Webber himself said, "we wanted to do Cats again ourselves, then the Palladium came up and Trevor fell in love with it. We’re taking the Cats show that’s touring and working on it afresh." The musical returned to the London Palladium for a run lasting from 23 October 2015 to 2 January 2016 starring Beverley Knight as Grizabella.
The lyric, written by "Cats" director Trevor Nunn, was loosely based on T. S. Eliot's poems "Preludes" and 
"Rhapsody on a Windy Night"." Andrew Lloyd Webber's former writing partner Tim Rice and contemporary collaborator Don Black submitted a lyric to the show's producers for consideration, although Nunn's version was favoured. Elaine Paige has said that she sang a different lyric to the tune of "Memory" for the first ten previews of "Cats".
The brain of the domesticated cat is about long, and weighs . If a typical cat is taken to be long with a weight of , then the brain would be at 0.91% of its total body mass, compared to 2.33% of total body mass in the average human. Within the encephalization quotient proposed by Jerison in 1973, values above 1 are classified big brained, while values lower than 1 are small brained. The domestic cat is attributed a value of between 1–1.71 relative to human value that is 7.44–7.8. The largest brains in the Felidae family are those of the tigers in Java and Bali, of which the largest relative brain size within the "panthera" is the "tigris". It is debated whether there exists a causal relationship between brain size and intelligence in vertebrates. Correlations have been shown between these factors in a number of experiments. However, correlation does not imply causation. Most experiments involving the relevance of brain size to intelligence hinge on the assumption that complex behavior requires a complex (and therefore intelligent) brain; however, this connection has not been consistently demonstrated.
In "The Obsequies of an Egyptian Cat" (1886, 32 x 49"), a priestess kneels before an altar upon which is placed the mummy of a cat. She is burning incense, and has presented offerings of flowers and food to the cat's spirit, together with a plate of milk. On the wall behind the priestess is an Egyptian fresco, and a statue of the goddess Sekhmet or Bastet enthroned guards the entrance to the temple. Stairs lead up to the doorway, through which a view of the sky and other buildings are visible.
The signs of diabetes mellitus are caused by a persistently high blood glucose concentration, which may be caused by either insufficient insulin, or by a lack of response to insulin. Most cats have a type of diabetes mellitus similar to human diabetes mellitus type 2, with β-cell dysfunction and insulin resistance. Factors which contribute to insulin resistance include obesity and endocrine diseases such as acromegaly. Acromegaly affects 20–30% of diabetic cats; it can be diagnosed by measuring the concentration of insulin-like growth factor-1 (IGF-1) in the blood.
Funerary cults are especially associated with ancient Egypt, where it was common for royalty, those associated with royalty, cats, and the wealthy to be mummified. This practice was done so as to preserve their bodies for the journey to the afterlife. The deity Osiris, who was the dying and reviving god and Lord of the Egyptian afterlife, was usually depicted as a mummy in Egyptian art. Also at Bubastis, where Bast was worshiped, there was a massive cat cemetery. Cats were also thought to journey to the afterlife, usually to join their owners. These needed their own material goods for this journey, such as food.
A fully-grown "Smilodon" weighed approximately and had a short tail, powerful legs, and a large head. The cats have two huge canine teeth, about long, that are used to kill prey by suffocation. The jaws could open to about 120 degrees in order to use these fangs to deadly effect. They would die out due to climate change.
Under the Second Spanish Republic Catalonia obtained a Statute of Home Rule in 1932, with a regional administration given the old name of "Generalitat". Autonomous government was suppressed upon the victory of the Spanish Nationalists in 1939, to be restored under the 1978 Constitution as the "Generalitat de Catalunya". Tension built up following the judicial suspension of parts of a revised Statute of Autonomy in 2010, in particular concerning autonomy in taxation policy and the use of the term "nation". There were massive demonstrations in 2010 and 2012, after which the Catalan government organised independence referendums in 2014 and 2017, the latter forming the basis for the Catalan declaration of independence of 2017.
The presence of a distinct Catalan language has been seen as the basis for "the claim of Catalonia to be considered as something more than a mere region". Catalan is spoken also in Valencia, the Balearics, and certain adjacent areas of France. The language was prevalent in Catalonia and beyond during the Middle Ages, but "died as a language of culture in the early 16th century", being revived in the 19th century with the "Renaixença". The use of the language was restricted under Franco, but since then it has achieved the status of co-official language and has been actively promoted by Catalonia's government.
The general bite-and-retreat hypothesis has been criticised because of its bloodiness and because the struggling prey would have attracted any predators and scavengers in the area. The idea that a single animal would wound, release, and follow a prey animal has been counteracted more strongly. Cats rarely walk away from prey until they have eaten their fill and it would have risked being stolen by other predators.
Relaxation techniques, such as exercise, yoga or meditation, may be useful in relieving the stress that may aggravate tics, but the majority of behavioral interventions (such as relaxation training and biofeedback, with the exception of habit reversal) have not been systematically evaluated and are not empirically supported therapies for Tourette's. Deep brain stimulation has been used to treat adults with severe Tourette's that does not respond to conventional treatment, but it is regarded as an invasive, experimental procedure that is unlikely to become widespread.
The new Statute of Autonomy of Catalonia, approved by referendum, was contested by important sectors of the Spanish nationalism and the conservative People's Party, sending the law to the partisan Constitutional Court of Spain which, in 2010, decided to declare non valid some of the articles that established an autonomous Catalan system of Justice, better aspects of the financing, the status of the Catalan language or the references of Catalonia as a nation. As a response, on 10 July 2010, a successful demonstration was held, and the civil society started a process of organization in order to exert the right of self-determination. While the economic crisis affected profoundly Spain, CiU win the Catalan election of 2010, promising a fiscal agreement similar to the Basque. Its leader, Artur Mas, was appointed as president. Initially supported by the PP, his government carried out a program of austerity. During the National Day of Catalonia, on 11 September 2012, a massive demonstration in the streets of Barcelona organized by the organization Catalan National Assembly ("Assemblea Nacional Catalana", ANC) claimed for independence and a referendum of self-determination.
Banjo the Woodpile Cat is a 1979 animated short film directed by Don Bluth. It follows the story of Banjo, an overly curious and rebellious kitten who, after getting into trouble for falling from a house to see if he could land on his feet, runs away from his woodpile home in his owners' farm in Payson, Utah by catching a truck to Salt Lake City. Produced in a shoestring budget, and created in Bluth's garage, the film took four years to make and it was the first production of Don Bluth Productions, later Sullivan Bluth Studios. It had a short theatrical run from December 21 to 28, 1979 at the Egyptian Theatre in Hollywood and the Peppertree Cinema in Northridge as an opening short for the holiday re-release of "The Muppet Movie", but did not appear on network television until 1982.
Habit reversal training (HRT), massed negative practice, biofeedback, relaxation, hypnosis and other behavioral approaches are proposed as alternative treatments of tics, but few have been well assessed. Relaxation techniques, such as exercise, yoga or meditation, may be useful in relieving stress that may aggravate tics, but the majority of behavioral interventions (such as relaxation training and biofeedback, with the exception of habit reversal) have not been systematically evaluated and are not proven therapies for Tourette's.
The mechanism by which cats purr is an object of speculation. There is a unique "neural oscillator" in the cat’s brain of uncertain significance.
No cat can both purr and roar. The subdivision of the Felidae into "purring cats" on one hand and "roaring cats" on the other goes back to Owen (1834/1835) and was definitively introduced by Pocock (1916), based on whether the hyoid bone of the larynx is incompletely ("roarers") or completely ("purrers") ossified. However, Weissengruber et al. (2002) argued that the ability of a cat species to purr is not affected by the anatomy of its hyoid.
It was once believed that only the cats of the genus "Felis" could purr. However, felids of the genus "Panthera" (tigers, lions, jaguars and leopards) also produce sounds similar to purring, but only when exhaling. The subdivision of the Felidae into ‘purring cats’ on the one hand and ‘roaring cats ’ (i.e. non-purring) on the other, originally goes back to Owen (1834/1835) and was definitely introduced by Pocock (1916), based on a difference in hyoid anatomy. The ‘roaring cats’ (lion, "Panthera leo"; tiger, "P. tigris"; jaguar, "P. onca"; leopard, "P. pardus") have an incompletely ossified hyoid, which according to this theory, enables them to roar but not to purr. On the other hand, the snow leopard ("Uncia uncia"), as the fifth felid species with an incompletely ossified hyoid, purrs (Hemmer, 1972). All remaining species of the family Felidae (‘purring cats’) have a completely ossified hyoid which enables them to purr but not to roar. However, Weissengruber et al. (2002) argued that the ability of a cat species to purr is not affected by the anatomy of its hyoid, i.e. whether it is fully ossified or has a ligamentous epihyoid, and that, based on a technical acoustic definition of roaring, the presence of this vocalization type depends on specific characteristics of the vocal folds and an elongated vocal tract, the latter rendered possible by an incompletely ossified hyoid.
Purring may have developed as an evolutionary advantage as a signalling mechanism of reassurance between mother cats and nursing kittens. Post-nursing cats often purr as a sign of contentment: when being petted, becoming relaxed, or eating. The mechanism by which cats purr is elusive. The cat has no unique anatomical feature that is clearly responsible for the sound. It was until recent times, believed that only the cats of the "Felis" genus could purr. However, felids of the genus "Panthera" (tiger, lion, jaguar, and leopard) also produce non-continuous sounds, called "chuffs", similar to purring, but only when exhaling.