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Yaks
The yak (''Bos grunniens''), also known as the Tartary ox, grunting ox, hairy cattle, or domestic yak, is a species of long-haired domesticated cattle found throughout the Himalayan region, the Tibetan Plateau, Tajikistan, the Pamir Mountains, and as far north as Mongolia and Siberia. It is descended from the wild yak (''Bos mutus''). Etymology The English word ''yak'' originates from the . In Tibetan and Balti it refers only to the male of the species, the female being called or in Tibetan and 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 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 suggesti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Himalayas
The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than list of highest mountains on Earth, 100 peaks exceeding elevations of above sea level lie in the Himalayas. The Himalayas abut on or cross territories of Himalayan states, six countries: Nepal, China, Pakistan, Bhutan, India and Afghanistan. The sovereignty of the range in the Kashmir region is disputed among India, Pakistan, and China. The Himalayan range is bordered on the northwest by the Karakoram and Hindu Kush ranges, on the north by the Tibetan Plateau, and on the south by the Indo-Gangetic Plain. Some of the world's major rivers, the Indus River, Indus, the Ganges river, Ganges, and the Yarlung Tsangpo River, Tsangpo–Brahmaputra River, Brahmaputra, rise in the vicinity of the Himalayas, and their combined drainage basin is home to some 6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-altitude Adaptation
Organisms can live at high altitude, either on land, in water, or while flying. Decreased oxygen availability and decreased temperature make life at such altitudes challenging, though many species have been successfully adapted via considerable physiological changes. As opposed to short-term acclimatisation (immediate physiological response to changing environment), high-altitude adaptation means irreversible, evolved physiological responses to high-altitude environments, associated with heritable behavioural and genetic changes. Among vertebrates, only few mammals (such as leaf-eared mice, yaks, ibexes, Tibetan gazelles, vicunas, llamas, mountain goats, etc.) and certain birds are known to have completely adapted to high-altitude environments. Human populations such as some Tibetans, South Americans and Ethiopians live in the otherwise uninhabitable high mountains of the Himalayas, Andes and Ethiopian Highlands respectively. The adaptation of humans to high altitude is an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wild Yak
The wild yak (''Bos mutus'') is a large, wild bovine native to the Himalayas. It is the ancestor of the domestic yak (''Bos grunniens''). Taxonomy The ancestor of the wild and domestic yak is thought to have diverged from '' Bos primigenius'' at a point between one and five million years ago. The wild yak is now normally treated as a separate species from the domestic yak (''Bos grunniens''). Based on genomic evidence, the closest relatives of yaks are considered to be bison, which have historically been considered members of their own titular genus, rendering the genus '' Bos'' paraphyletic. Relationships of members of the genus ''Bos'' based on nuclear genomes after Sinding, et al. 2021. Description The wild yak is among the largest extant bovid species. Adults stand about tall at the shoulder, and weigh . The head and body length is , not counting the tail of .Han Jianlin, M. Melletti, J. Burton, 2014, Wild yak (Bos mutus Przewalski, 1883), Ecology, Evolution and Behavio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chagan-Uzun
Chagan-Uzun (; , ''Çagan-Uzun'') is a types of inhabited localities in Russia, rural locality (a Village#Russia, selo) in Kosh-Agachsky District, the Altai Republic, Russia. The population was 439 as of 2016. There are 5 streets. Geography Chagan-Uzun is located 29 km northwest of Kosh-Agach (the district's administrative centre) by road. Ortolyk is the nearest rural locality. References Rural localities in Kosh-Agachsky District {{AltaiRepublic-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Commission On Zoological Nomenclature
The International Commission on Zoological Nomenclature (ICZN) is an organization dedicated to "achieving stability and sense in the scientific naming of animals". Founded in 1895, it currently comprises 26 commissioners from 20 countries. Organization The ICZN is governed by the "Constitution of the ICZN", which is usually published together with the ICZN Code. Members are elected by the Section of Zoological Nomenclature, established by the International Union of Biological Sciences (IUBS). The regular term of service of a member of the Commission is six years. Members can be re-elected up to a total of three full six-year terms in a row. After 18 continuous years of elected service, a break of at least three years is prescribed before the member can stand again for election. Activities Since 2014, the work of the Commission is supported by a small secretariat based at the National University of Singapore, in Singapore. Previously, the secretariat was based in London and f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subcutaneous Fat
The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, or superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and macrophages. The subcutaneous tissue is derived from the mesoderm, but unlike the dermis, it is not derived from the mesoderm's dermatome region. It consists primarily of loose connective tissue and contains larger blood vessels and nerves than those found in the dermis. It is a major site of fat storage in the body. In arthropods, a hypodermis can refer to an epidermal layer of cells that secretes the chitinous cuticle. The term also refers to a layer of cells lying immediately below the epidermis of plants. Structure * Fibrous bands anchoring the skin to the deep fascia * Collagen and elastin fibers attaching it to the dermis * Fat is absent from the eyelids, clitoris, penis, much of pinna, and scrotum * Blood vessels on route to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foetal Haemoglobin
Fetal hemoglobin, or foetal haemoglobin (also hemoglobin F, HbF, or α2γ2) is the main oxygen carrier protein in the human fetus. HemoglobinF is found in fetal red blood cells, and is involved in transporting oxygen from the mother's bloodstream to organs and tissues in the fetus. It is produced at around 6weeks of pregnancy and the levels remain high after birth until the baby is roughly 2–4months old. HemoglobinF has a different composition than adult forms of hemoglobin, allowing it to bind (or attach to) oxygen more strongly; this in turn enables the developing fetus to retrieve oxygen from the mother's bloodstream, which occurs through the placenta found in the mother's uterus. In the newborn, levels of hemoglobin F gradually decrease and reach adult levels (less than 1% of total hemoglobin) usually within the first year, as adult forms of hemoglobin begin to be produced. Diseases such as beta thalassemias, which affect components of the adult hemoglobin, can delay this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Yak Rider
''The'' is a grammatical article in English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of the archaic pronoun ''thee' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nikolay Przhevalsky
Nikolay Mikhaylovich Przhevalsky (or Prjevalsky;; , . – ) was a Russian geographer and a renowned explorer of Central and East Asia. Although he never reached his ultimate goal, the city of Lhasa in Tibet, he still travelled through regions then unknown to Westerners, such as northern Tibet (modern Tibet Autonomous Region), Amdo (now Qinghai) and Dzungaria (now northern Xinjiang). He contributed substantially to European knowledge of Central Asian geography. Przhevalsky described several species previously unknown to European science, such as Przewalski's horse, Przewalski's gazelle, and the wild Bactrian camel, all of which are now endangered. He was also a mentor of the explorer Pyotr Kozlov. Biography Przhevalsky was born in the Kimborovo family estate (in the Smolensky Uyezd of the Smolensk Governorate of the Russian Empire) which belonged to his grandfather from his mother's side, a Russian nobleman Aleksei Stepanovich Karetnikov, and his wife Ksenia Davydovna Karet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teat
A teat is the projection from the mammary glands of mammals from which milk flows or is ejected for the purpose of feeding young. In many mammals, the teat projects from the udder. The number of teats varies by mammalian species and often corresponds to the average litter size for that animal. In some cases, the teats of female animals are milked for the purpose of human consumption. The quality of some domesticated animals is determined by the establishment of desired characteristics, such as teat size and placement. Number and positioning in other animals The number and positioning of mammary glands and teats varies widely among mammals. The protruding teats and accompanying glands can be located anywhere along the two milk lines. In general, most mammals develop mammary glands in pairs along these lines, with a number approximating the number of young typically birthed at a time. The number of teats varies from 2 (in elephants and anthropoids) to 18 (in pigs). Marsupials u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scrotum
In most terrestrial mammals, the scrotum (: scrotums or scrota; possibly from Latin ''scortum'', meaning "hide" or "skin") or scrotal sac is a part of the external male genitalia located at the base of the penis. It consists of a sac of skin containing the external spermatic fascia, testicles, epididymides, and vasa deferentia. The scrotum will usually tighten when exposed to cold temperatures. The scrotum is homologous to the labia majora in females. Structure In regards to humans, the scrotum is a suspended two-chambered sac of skin and muscular tissue containing the testicles and the lower part of the spermatic cords. It is located behind the penis and above the perineum. The perineal raphe is a small, vertical ridge of skin that expands from the anus and runs through the middle of the scrotum front to back. The scrotum is also a distention of the perineum and carries some abdominal tissues into its cavity including the testicular artery, testicular vein, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
