Yak

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Yak
Bos grunniens at Letdar on Annapurna Circuit.jpg
A yak in the Nepalese Himalayas.
Domesticated
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Bovinae
Genus: Bos
Species:
B. grunniens
Binomial name
Bos grunniens
Linnaeus, 1766
Synonyms

Poephagus grunniens

The yak (Bos grunniens), also known as the Tartary ox, grunting ox, [1] or hairy cattle, [2] is a species of long-haired domesticated cattle found throughout the Himalayan region of Gilgit-Baltistan (Kashmir, Pakistan), Nepal, Sikkim (India), the Tibetan Plateau, (China), Tajikistan and as far north as Mongolia and Siberia. It is descended from the wild yak (Bos mutus). [3]

Contents

Etymology

The English word yak originates from the Tibetan : གཡག་, Wylie : g.yag. In Tibetan and Balti it refers only to the male of the species, the female being called Tibetan : འབྲི་, Wylie : bri, Tibetan: འབྲི་, Wylie: dri or Tibetan : གནག, Wylie : g.nag in Tibetan and Tibetan : ཧཡག་མོ་, Wylie : hYag-mo in Balti. In English, as in most other languages that have borrowed the word, yak is usually used for both sexes, with bull or cow referring to each sex separately.

Taxonomy

Bronze model of yak from Gansu, China. Yuan dynasty, 1271-1368 AD Gansu Museum 2007 318.jpg
Bronze model of yak from Gansu, China. Yuan dynasty, 1271–1368 AD

Belonging to the genus Bos , Yaks are related to cattle (Bos primigenius). Mitochondrial DNA analyses to determine the evolutionary history of yaks have been inconclusive.

The yak may have diverged from cattle at any point between one and five million years ago, and there is some suggestion that it may be more closely related to bison than to the other members of its designated genus. [4] Apparent close fossil relatives of the yak, such as Bos baikalensis , have been found in eastern Russia, suggesting a possible route by which yak-like ancestors of the modern American bison could have entered the Americas. [5]

The species was originally designated as Bos grunniens ("grunting ox") by Linnaeus in 1766, but this name is now generally considered to refer only to the domesticated form of the animal, with Bos mutus ("mute ox") being the preferred name for the wild species. Although some authors still consider the wild yak to be a subspecies, Bos grunniens mutus, the ICZN made an official ruling in 2003 [6] permitting the use of the name Bos mutus for wild yaks, and this is now the more common usage. [7] [5] [8]

Except where the wild yak is considered as a subspecies of Bos grunniens, there are no recognised subspecies of yak.

Physical characteristics

A domestic yak at Yamdrok Lake. Bos grunniens at Yundrok Yumtso Lake.jpg
A domestic yak at Yamdrok Lake.

Yaks are heavily built animals with bulky frames, sturdy legs, rounded, cloven hooves, and extremely dense, long fur that hangs down lower than the belly. While wild yaks are generally dark, blackish to brown in colouration, domestic yaks can be quite variable in colour, often having patches of rusty brown and cream. They have small ears and wide foreheads, with smooth horns that are generally dark in colour. In males (bulls), the horns sweep out from the sides of the head, and then curve backward; they typically range from 48 to 99 cm (19 to 39 in) in length.

The horns of females (cows) are smaller, at 27 to 64 cm (11 to 25 in) in length, and have a more upright shape. Both sexes have a short neck with a pronounced hump over the shoulders, although this is larger and more visible in males. [5] Males weigh 350 to 585 kg (772 to 1,290 lb), females weigh 225 to 255 kg (496 to 562 lb). Wild yaks can be substantially heavier, bulls reaching weights of up to 1,000 kilograms (2,200 lb). [9] Depending on the breed, domestic yak males are 111–138 centimetres (44–54 in) high at the withers, while females are 105–117 centimetres (41–46 in) high at the withers. [10]

Both sexes have long shaggy hair with a dense woolly undercoat over the chest, flanks, and thighs to insulate them from the cold. Especially in bulls, this may form a long "skirt" that can reach the ground. The tail is long and horselike rather than tufted like the tails of cattle or bison. Domesticated yaks have a wide range of coat colours, with some individuals being white, grey, brown, roan or piebald. The udder in females and the scrotum in males are small and hairy, as protection against the cold. Females have four teats. [5]

Yaks are not known to produce the characteristic lowing (mooing) sound of cattle, but both wild and domestic yaks grunt and squeak, which inspired the scientific name of the domestic yak variant, Bos grunniens (grunting bull). Nikolay Przhevalsky named the wild variant Bos mutus (silent bull) believing that it did not make a sound at all, but it does. [11]

Physiology

Yak rider near Tsomgo Lake, Sikkim (3700 m) The Yak Rider.JPG
Yak rider near Tsomgo Lake, Sikkim (3700 m)

Yak physiology is well adapted to high altitudes, having larger lungs and heart than cattle found at lower altitudes, as well as greater capacity for transporting oxygen through their blood, [12] [13] due to the persistence of foetal haemoglobin throughout life. [14] Conversely, yaks have trouble thriving at lower altitudes, [15] and are prone to suffering from heat exhaustion above about 15 °C (59 °F). Further adaptations to the cold include a thick layer of subcutaneous fat, and an almost complete lack of functional sweat glands. [12]

Compared with domestic cattle, the rumen of yaks is unusually large, relative to the omasum.[ citation needed ] This likely allows them to consume greater quantities of low-quality food at a time, and to ferment it longer so as to extract more nutrients. [12] Yak consume the equivalent of 1% of their body weight daily while cattle require 3% to maintain condition.[ citation needed ] They are grazing herbivores, with their wild ancestors feeding primarily on grass and sedges, [16] with some herbs and dwarf shrubs. [17]

Reproduction and life history

Ten-day-old yak. Yak calf in Austria 2009.jpg
Ten-day-old yak.

Yaks mate in the summer, typically between July and September, depending on the local environment. For the remainder of the year, many bulls wander in small bachelor groups away from the large herds, but, as the rut approaches, they become aggressive and regularly fight among each other to establish dominance. In addition to non-violent threat displays, bellowing, and scraping the ground with their horns, bull yaks also compete more directly, repeatedly charging at each other with heads lowered or sparring with their horns. Like bison, but unlike cattle, males wallow in dry soil during the rut, often while scent-marking with urine or dung. [5] Females enter oestrus up to four times a year, and females are receptive only for a few hours in each cycle. [18]

Gestation lasts between 257 and 270 days, [12] so that the young are born between May and June, and results in the birth of a single calf. The cow finds a secluded spot to give birth, but the calf is able to walk within about ten minutes of birth, and the pair soon rejoin the herd. [12] Females of both the wild and domestic forms typically give birth only once every other year, [5] although more frequent births are possible if the food supply is good.

Calves are weaned at one year and become independent shortly thereafter. Wild calves are initially brown in color, and only later develop the darker adult hair. Females generally give birth for the first time at three or four years of age, [19] and reach their peak reproductive fitness at around six years. Yaks may live for more than twenty years in domestication or captivity, [5] although it is likely that this may be somewhat shorter in the wild.

Husbandry

Domesticated yaks have been kept for thousands of years, primarily for their milk, fibre (wool), and meat, and as beasts of burden. Their dried droppings are an important fuel, used all over Tibet, and are often the only fuel available on the high, treeless Tibetan Plateau. Yaks transport goods across mountain passes for local farmers and traders and are an attraction for climbing and trekking expeditions: "Only one thing makes it hard to use yaks for long journeys in barren regions. They will not eat grain, which could be carried on the journey. They will starve unless they can be brought to a place where there is grass." [20] They also are used to draw ploughs. [21] Yaks' milk is often processed to a cheese called chhurpi in Tibetan and Nepali languages, and byaslag in Mongolia. Butter made from yaks' milk is an ingredient of the butter tea that Tibetans consume in large quantities, [22] and is also used in lamps and made into butter sculptures used in religious festivities. [23]

Yak racing Yak racing.jpg
Yak racing

Outside the Himalayas

Small numbers of herds can be found in the United States and Canada, as well as New Zealand and some parts of Europe. Yaks have generated interest outside the Himalayas as a commercial crop and by cattle breeders. The main interest of North American yak breeders is lean meat production by hybridizing with other cattle, followed by wool production. [24]

Research

The Indian government established a dedicated centre for research into yak husbandry, the ICAR-National Research Centre on Yak, in 1989. It is located at Dirang, Arunachal Pradesh, and maintains a yak farm in the Nyukmadung area at an altitude of 2,750 metres (9,020 ft) above MSL. [25]

Yak breeding and hybridization

In Nepal, Tibet, and Mongolia, domestic cattle are crossbred with yaks. This gives rise to the infertile male dzo མཛོ། as well as fertile females known as dzomo or zhom མཛོ་མོ།, which may be crossed again with cattle. The Dwarf Lulu breed, "the only Bos primigenius taurus type of cattle in Nepal" has been tested for DNA markers and found to be a mixture of both taurine and zebu types of cattle (B. p. taurus and B. p. indicus) with yak. [26] According to the International Veterinary Information Service, the low productivity of second-generation cattle–yak crosses makes them suitable only as meat animals. [27]

Crosses between yaks and domestic cattle (Bos primigenius taurus) have been recorded in Chinese literature for at least 2,000 years. [5] Successful crosses have also been recorded between yak and American bison, [27] gaur, and banteng, generally with similar results to those produced with domestic cattle. [5]

Yak domestication

Jacques et al. (2021) [28] show that most elaborate yak-related terminologies are found within Tibetic and Gyalrongic languages. Both branches also have native terms for yak-cattle hybrids, suggesting that Tibetic and Gyalrongic speakers may have independently cross-bred yaks and cattle, predating the proto-Gyalrongic split (3221 [2169-4319] BP [29] ) from Tibeto-Gyalrongic. The oldest dated physical evidence of yak domestication is from 2,500 years BP. [30]

Customs

Blood-drinking festival

In Nepal, there is an annual festival held to drink the fresh blood of yak in the belief that it cures varieties of diseases such as gastritis, jaundice and body strain. [31] [32] The fresh blood is extracted from the neck of a yak without killing it. The cut is healed after the ceremony is over. [33] The ritual is believed to be originated in Tibet and Mustang. [34]

Yak sports

In parts of Tibet and Karakorum, yak racing is a form of entertainment at traditional festivals and is considered an important part of their culture. More recently, sports involving domesticated yaks, such as yak skiing or yak polo, are being marketed as tourist attractions in South Asian countries, including in Gilgit-Baltistan, Pakistan.[ citation needed ]

See also

Related Research Articles

<span class="mw-page-title-main">Aurochs</span> Extinct species of large cattle that inhabited Asia, Europe, and Northern Africa

The aurochs is an extinct cattle species, considered to be the wild ancestor of modern domestic cattle. With a shoulder height of up to 180 cm (71 in) in bulls and 155 cm (61 in) in cows, it was one of the largest herbivores in the Holocene; it had massive elongated and broad horns that reached 80 cm (31 in) in length.

<span class="mw-page-title-main">Beefalo</span> Hybrid of cattle and bison

Beefalo constitute a hybrid offspring of domestic cattle, usually a male in managed breeding programs, and the American bison, usually a female in managed breeding programs. The breed was created to combine the characteristics of both animals for beef production.

<span class="mw-page-title-main">Zebu</span> South Asian domestic cattle

The zebu, sometimes known in the plural as indicine cattle, Camel cow or humped cattle, is a species or subspecies of domestic cattle originating in South Asia. Zebu, like many Sanga cattle breeds, differs from taurine cattle by a fatty hump on their shoulders, a large dewlap, and sometimes drooping ears. They are well adapted to withstanding high temperatures and are farmed throughout the tropics.

<span class="mw-page-title-main">Bovinae</span> Subfamily of mammals

Bovines comprise a diverse group of 10 genera of medium to large-sized ungulates, including cattle, bison, African buffalo, water buffalos, and the four-horned and spiral-horned antelopes. The evolutionary relationship between the members of the group is still debated, and their classification into loose tribes rather than formal subgroups reflects this uncertainty. General characteristics include cloven hooves and usually at least one of the sexes of a species having true horns. The largest extant bovine is the gaur.

<i>Bos</i> Genus of wild and domestic cattle

Bos is a genus of bovines, which includes, among others, wild and domestic cattle.

<span class="mw-page-title-main">Dzo</span> Hybrid between the yak and domestic cattle

A dzo is a hybrid between the yak and domestic cattle. The word dzo technically refers to a male hybrid, while a female is known as a dzomo or zhom. In Mongolian, it is called a khainag (хайнаг). There is also the English language portmanteau term of yattle, a combination of the words yak and cattle, as well as yakow, a combination of the words yak and cow.

<span class="mw-page-title-main">Heck cattle</span> German breed of cattle

The Heck or Munich-Berlin is a German breed or type of domestic cattle. It was bred in the 1920s by Heinz and Lutz Heck in an attempt to breed back the extinct aurochs. Controversy revolves around methodology and success of the programme. There are considerable differences between Heck cattle and the aurochs in build, height, and body proportions. Furthermore, there are other cattle breeds which resemble their wild ancestors at least as much as Heck cattle.

<span class="mw-page-title-main">Gayal</span> Species of domestic cattle

The gayal, also known as the Drung ox or mithun, is a large domestic cattle distributed in Northeast India, Bangladesh, Myanmar and in Yunnan, China.

<span class="mw-page-title-main">Banteng</span> Species of wild bovine discovered in Southeast Asia

The banteng, also known as tembadau, is a species of wild bovine found in Southeast Asia.

The yakalo is a cross of the yak and the American bison. It was produced by hybridisation experiments in the 1920s, when crosses were made between yak bulls and both pure bison cows and bison-cattle hybrid cows. As with many other inter-specific crosses, only female hybrids were found to be fertile. Few of the hybrids survived, and the experiments were discontinued in 1928.

<span class="mw-page-title-main">Bovid hybrid</span> Crossbreeds in the bovid family

A bovid hybrid is the hybrid offspring of members of two different species of the bovid family. There are 143 extant species of bovid, and the widespread domestication of several species has led to an interest in hybridisation for the purpose of encouraging traits useful to humans, and to preserve declining populations. Bovid hybrids may occur naturally through undirected interbreeding, traditional pastoral practices, or may be the result of modern interventions, sometimes bringing together species from different parts of the world.

<span class="mw-page-title-main">Bovini</span> Tribe of cattle

The tribe Bovini or wild cattle are medium to massive bovines that are native to Eurasia, North America, and Africa. These include the enigmatic, antelope-like saola, the African and Asiatic buffalos, and a clade that consists of bison and the wild cattle of the genus Bos. Not only are they the largest members of the subfamily Bovinae, they are the largest species of their family Bovidae. The largest species is the gaur, weighing up to 1,500 kg (3,300 lb).

<span class="mw-page-title-main">Sanga cattle</span> Breed of cattle

Sanga cattle is the collective name for indigenous cattle of some regions in Africa. They are sometimes identified as a subspecies with the scientific name Bos taurus africanus. Their history of domestication and their origins in relation to taurine cattle, zebu cattle (indicine), and native African varieties of the ancestral aurochs are a matter of debate. "African taurine", "sanga", "zenga", "sheko", "African indicine" are all sub-groups of Sanga cattle.

<span class="mw-page-title-main">Indian aurochs</span>

The Indian aurochs is an extinct subspecies of aurochs that inhabited West Asia and the Indian subcontinent from the Late Pleistocene until its eventual extinction during the South Asian Stone Age. With no remains younger than 3,800 YBP ever recovered, the Indian aurochs was the first of the three aurochs subspecies to become extinct; the Eurasian aurochs and the North African aurochs persevered longer, with the latter bring known by the Roman Empire, and the former surviving until the mid-17th century in Central Europe.

<span class="mw-page-title-main">Cattle</span> Large, domesticated, cloven-hooved herbivores

Cattle are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus Bos. Mature female cattle are called cows and mature male cattle are bulls. Young female cattle are called heifers, young male cattle are oxen or bullocks, and castrated male cattle are known as steers.

<span class="mw-page-title-main">Yak butter</span> Butter made from yak milk

Yak butter is butter made from the milk of the domestic yak. Many herder communities in China, India, Mongolia, Nepal, Gilgit-Baltistan Pakistan and Tibet produce and consume dairy products made from yak's milk, including butter. Whole yak's milk has about twice the fat content of whole cow's milk, producing a butter with a texture closer to cheese. It is a staple food product and trade item for herder communities in south Central Asia and the Tibetan Plateau.

<span class="mw-page-title-main">Wild yak</span> Species of mammal

The wild yak is a large, wild bovine native to the Himalayas. It is the ancestor of the domestic yak.

Turano-Mongolian cattle are a group of taurine cattle that are found in Northern and Eastern Asia. They are morphologically and genetically distinct from the Near-Eastern group of taurine cattle, from which European cattle are descended; they may have been domesticated independently.

<span class="mw-page-title-main">Bovina (subtribe)</span> Subtribe of cattle

Bovina is a subtribe of the Bovini tribe that generally includes the two living genera, Bison and Bos. However, this dichotomy has been challenged recently by molecular work that suggests that Bison should be regarded as a subgenus of Bos. Wild bovinans can be found naturally in North America and Eurasia.

References

  1. ↑ Scherf, Beate (2000). "World Watch List for Domestic Animal Diversity" (PDF). World Watch List for Domestic Animal Diversity. FAO: 653.
  2. ↑ "Yak | mammal". Encyclopædia Britannica.
  3. ↑ Grubb, P. (2005). "Order Artiodactyla". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 691. ISBN   978-0-8018-8221-0. OCLC   62265494.
  4. ↑ Guo, S.; et al. (2006). "Taxonomic placement and origin of yaks: implications from analyses of mtDNA D-loop fragment sequences". Acta Theriologica Sinica. 26 (4): 325–330.
  5. 1 2 3 4 5 6 7 8 9 Leslie, D.M.; Schaller, G.B. (2009). "Bos grunniens and Bos mutus (Artiodactyla: Bovidae)". Mammalian Species. 836: 1–17. doi: 10.1644/836.1 .
  6. ↑ International Commission on Zoological Nomenclature (2003). "Opinion 2027. Usage of 17 specific names based on wild species which are predated by or contemporary with those based on domestic animals (Lepidoptera, Osteichthyes, Mammalia): conserved". Bulletin of Zoological Nomenclature. 60: 81–84.
  7. ↑ Buzzard, P.; Berger, J. (2016). "Bos mutus". IUCN Red List of Threatened Species . 2016: e.T2892A101293528. doi: 10.2305/IUCN.UK.2016-2.RLTS.T2892A101293528.en . Retrieved 12 November 2021.
  8. ↑ Gentry, A.; Clutton-Brock, J.; Groves, C. P. (2004). "The naming of wild animal species and their domestic derivatives". Journal of Archaeological Science. 31 (5): 645. doi:10.1016/j.jas.2003.10.006.
  9. ↑ Buchholtz, C. (1990). True Cattle (Genus Bos). pp. 386–397 in S. Parker, ed. Grzimek's Encyclopedia of Mammals, Volume 5. New York: McGraw-Hill Publishing Company. (quoted in Oliphant, M. (2003). Bos grunniens (On-line), Animal Diversity Web. Accessed 4 April 2009)
  10. ↑ "The Yak. Chapter 2: Yak breeds". FAO. Retrieved 31 August 2017.
  11. ↑ "Origins, Domestication and Distribution of Yak". FAO. Retrieved 31 August 2017.
  12. 1 2 3 4 5 "The Yak in Relation to Its Environment". FAO.
  13. ↑ The Yak, Second Edition. Bangkok: Regional Office for Asia and the Pacific Food and Agriculture Organization of the United Nations, ISBN   92-5-104965-3. Accessed 8 August 2008.
  14. ↑ Sarkar, M.; Das, D. N.; Mondal, D. B. (1999). "Fetal Haemoglobin in Pregnant Yaks (Poephagus grunniens L.)". The Veterinary Journal. 158 (1): 68–70. doi:10.1053/tvjl.1999.0361. PMID   10409419.
  15. ↑ Yak, Animal genetics training resources version II: Breed Information. Adopted from: Bonnemaire, J. "Yak". In: Mason, Ian L. (ed). (1984). Evolution of Domesticated Animals. London: Longman, pp. 39–45. ISBN   0-582-46046-8. Accessed 8 August 2008.
  16. ↑ Harris, R.B.; Miller, D.J. (October 2009). "Overlap in summer habitats and diets of Tibetan Plateau ungulates". Mammalia. 59 (2): 197–212. doi:10.1515/mamm.1995.59.2.197. S2CID   84659876.
  17. ↑ Schaller, G.B.; Liu, W. (1996). "Distribution, status, and conservation of wild yak Bos grunniens". Biological Conservation. 76 (1): 1–8. doi:10.1016/0006-3207(96)85972-6.
  18. ↑ Sarkar, M.; Prakash, B.S. (2005). "Timing of ovulation in relation to onset of estrus and LH peak in yak (Poephagus grunniens L.)". Animal Reproduction Science. 86 (4): 353–362. doi:10.1016/j.anireprosci.2004.08.005. PMID   15766812.
  19. ↑ Zi, X.D. (2003). "Reproduction in female yaks (Bos grunniens) and opportunities for improvement". Theriogenology. 59 (5–6): 1303–1312. doi:10.1016/S0093-691X(02)01172-X. PMID   12527077.
  20. ↑ Golden Book Encyclopedia, Vol. 16 p. 1505b. Rockefeller Center, NY: Golden Press (1959).
  21. ↑ Gyamtsho, Pema. "Economy of Yak Herders" (PDF).
  22. ↑ Tibet and Tibetan Foods. Flavorandfortune.com. Retrieved on 2012-12-19.
  23. ↑ Yaks, butter & lamps in Tibet, webexhibits.org
  24. ↑ "Part 3 - Yak in nontraditional environments by Gerald Wiener". FAO.
  25. ↑ "ICAR-National Research Centre on Yak".
  26. ↑ Takeda, K.; Satoh, M.; Neopane, S.P.; Kuwar, B.S.; Joshi, H.D.; Shrestha, N.P.; Fujise, H.; Tasai, M.; Tagami, T.; Hanada, H. (2004). "Mitochondrial DNA analysis of Nepalese domestic dwarf cattle Lulu". Animal Science Journal. 75 (2): 103. doi:10.1111/j.1740-0929.2004.00163.x.
  27. 1 2 Zhang, R.C. (14 December 2000). "Interspecies Hybridization between Yak, Bos taurus and Bos indicus and Reproduction of the Hybrids". In: Recent Advances in Yak Reproduction, Zhao, X.X.; Zhang, R.C. (eds.). International Veterinary Information Service.
  28. ↑ Jacques, G.; d'Alpoim Guedes, J.; Zhang, S. (2021). "Yak Domestication: A Review of Linguistic, Archaeological, and Genetic Evidence". Ethnobiology Letters. 12 (1): 103–114. doi: 10.14237/ebl.12.1.2021.1755 . S2CID   238997533.
  29. ↑ Sagart, L.; Jacques, G.; Lai, Y.; Ryder, R.J.; Thouzeau, V.; Greenhill, S.J.; List, J.-M. (2019). "Dated language phylogenies shed light on the ancestry of Sino-Tibetan". Ethnobiology Letters. 116 (21): 10317–10322. Bibcode:2019PNAS..11610317S. doi: 10.1073/pnas.1817972116 . PMC   6534992 . PMID   31061123.
  30. ↑ "Earliest evidence for domestic yak found using both archaeology, ancient DNA". ScienceDaily. 13 December 2023. Retrieved 14 December 2023.
  31. ↑ Degen, Allan A.; Kam, Michael; Pandey, Shambhu B.; Upreti, Chet R.; Pandey, Sanjeev; Regmi, Prajwal (21 October 2007). "Transhumant Pastoralism in Yak Production in the Lower Mustang District of Nepal". Nomadic Peoples. 11 (2): 57–85. doi:10.3167/np.2007.110204.
  32. ↑ "People flock to Mustang to drink yak blood" . Retrieved 7 June 2021.
  33. ↑ "Festival to drink Yak blood begins in Nepal". Hindustan Times. 20 July 2008. Retrieved 7 June 2021.
  34. ↑ Ians (11 March 2010). "Nepal now sees blood drinking festival". The Hindu. Kathmandu. ISSN   0971-751X . Retrieved 7 June 2021.
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