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EDAR (gene)
Ectodysplasin A receptor (EDAR) is a protein that in humans is encoded by the ''EDAR'' gene. EDAR is a cell surface receptor for ectodysplasin A which plays an important role in the development of ectodermal tissues such as the skin. It is structurally related to members of the TNF receptor superfamily. Function ''EDAR'' and other genes provide instructions for making proteins that work together during embryonic development. These proteins form part of a signaling pathway that is critical for the interaction between two cell layers, the ectoderm and the mesoderm. In the early embryo, these cell layers form the basis for many of the body's organs and tissues. Ectoderm-mesoderm interactions are essential for the proper formation of several structures that arise from the ectoderm, including the skin, hair, nails, teeth, and sweat glands. Clinical significance Mutation in this gene have been associated with hypohidrotic ectodermal dysplasia, a disorder characterized by a lower de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethnic Groups Of Africa
The ethnic groups of Africa number in the thousands, with each ethnicity generally having their own language (or dialect of a language) and culture. The ethnolinguistic groups include various Afroasiatic, Khoisan, Niger-Congo, and Nilo-Saharan populations. The official population count of the various ethnic groups in Africa is highly uncertain due to limited infrastructure to perform censuses, and due to rapid population growth. Some groups have alleged that there is deliberate misreporting in order to give selected ethnicities numerical superiority (as in the case of Nigeria's Hausa, Fulani, Yoruba, and Igbo peoples). A 2009 genetic clustering study, which genotyped 1327 polymorphic markers in various African populations, identified six ancestral clusters. The clustering corresponded closely with ethnicity, culture, and language. A 2018 whole genome sequencing study of the world's populations observed similar clusters among the populations in Africa. At K=9, distinct ancestr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koreans
Koreans are an East Asian ethnic group native to the Korean Peninsula. The majority of Koreans live in the two Korean sovereign states of North and South Korea, which are collectively referred to as Korea. As of 2021, an estimated 7.3 million ethnic Korean diaspora, Koreans resided outside of Korea. Koreans are also an officially recognised ethnic minority in other several Continental and East Asian countries, including Koreans in China, China, Koreans in Japan, Japan, Koryo-saram, Kazakhstan, Koryo-saram, Russia, and Koryo-saram, Uzbekistan. Outside of Continental and East Asia, sizeable Korean communities have formed in Koreans in Germany, Germany, the British Koreans, United Kingdom, Koreans in France, France, the Korean Americans, United States, Korean Canadians, Canada, Korean Australians, Australia, and Korean New Zealanders, New Zealand. Etymology South Koreans refer to themselves as ''Hanguk-in'' or ''Hanguk-saram'', both of which mean "people of the Han". The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Asia
East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Japan, Japan, Economy of South Korea, South Korea, and Economy of Taiwan, Taiwan are among the world's largest and most prosperous. East Asia borders North Asia to the north, Southeast Asia to the south, South Asia to the southwest, and Central Asia to the west. To its east is the Pacific Ocean. East Asia, especially History of China, Chinese civilization, is regarded as one of the earliest Cradle of civilization#China, cradles of civilization. Other ancient civilizations in East Asia that still exist as independent countries in the present day include the History of Japan, Japanese, History of Korea, Korean, and History of Mongolia, Mongolian civilizations. Various other civilizations existed as independent polities in East Asia in the past ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Asia
North Asia or Northern Asia () is the northern region of Asia, which is defined in geography, geographical terms and consists of three federal districts of Russia: Ural Federal District, Ural, Siberian Federal District, Siberian, and the Far Eastern Federal District, Far Eastern. North Asia is bordered by the Arctic Ocean to its north; by Eastern Europe to its west; by Central Asia and East Asia to its south; and by the Pacific Ocean and Northern America to its east. It covers an area of , or 8.8% of Earth's total land area; and is the largest subregion of Asia by area, occupying approx. 29.4% of Asia's land area, but is also the least populated, with a population of around 37 million, accounting for merely 0.74% of Asia's population. Topographically, the region is dominated by the Eurasian Plate, except for its eastern part, which lies on the North American Plate, North American, Amurian Plate, Amurian, and Okhotsk Plates. It is divided by three major plains: the West Siberian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin D
Vitamin D is a group of structurally related, fat-soluble compounds responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, along with numerous other biological functions. In humans, the most important compounds within this group are vitamin D3 ( cholecalciferol) and vitamin D2 ( ergocalciferol). Unlike the other twelve vitamins, vitamin D is only conditionally essential, as with adequate skin exposure to the ultraviolet B (UVB) radiation component of sunlight there is synthesis of cholecalciferol in the lower layers of the skin's epidermis. For most people, skin synthesis contributes more than diet sources. Vitamin D can also be obtained through diet, food fortification and dietary supplements. In the U.S., cow's milk and plant-based milk substitutes are fortified with vitamin D3, as are many breakfast cereals. Government dietary recommendations typically assume that all of a person's vitamin D is taken by mouth, given the potential for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beringia
Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 70th parallel north, 72° north latitude in the Chukchi Sea; and on the south by the tip of the Kamchatka Peninsula. It includes the Chukchi Sea, the Bering Sea, the Bering Strait, the Chukchi Peninsula, Chukchi and Kamchatka peninsulas in Russia as well as Alaska in the United States and Yukon in Canada. The area includes land lying on the North American Plate and Siberian land east of the Chersky Range. At various times, it formed a land bridge referred to as the Bering land bridge, that was up to wide at its greatest extent and which covered an area as large as British Columbia and Alberta together, totaling about , allowing biological dispersal to occur between Asia and North America. Today, the only land that is visible from the central part of the Bering land bridge are the Diomede Islands, the Pribilof Isla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and greenhouse periods during which there are no glaciers on the planet. Earth is currently in the ice age called Quaternary glaciation. Individual pulses of cold climate within an ice age are termed '' glacial periods'' (''glacials, glaciations, glacial stages, stadials, stades'', or colloquially, ''ice ages''), and intermittent warm periods within an ice age are called '' interglacials'' or ''interstadials''. In glaciology, the term ''ice age'' is defined by the presence of extensive ice sheets in the northern and southern hemispheres. By this definition, the current Holocene epoch is an interglacial period of an ice age. The accumulation of anthropogenic greenhouse gases is projected to delay the next glacial period. History of research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tianyuan Man
Tianyuan man ( zh, t=田園洞人, s=田园洞人, p=Tiányuándòng Rén) are the remains of one of the earliest modern humans to inhabit East Asia. In 2007, researchers found 34 bone fragments belonging to a single individual at the Tianyuan Cave near Beijing, China. Radiocarbon dating shows the bones to be between 42,000 and 39,000 years old, which may be slightly younger than the only other finds of bones of a similar age at the Niah Caves in Sarawak on the South-east Asian island of Borneo. Subsistence Nothing is known directly about the material culture of this individual, since so far no artifacts or other cultural remains have been found at the site. Isotope analysis suggests that a substantial part of his diet came from freshwater fish. Physical anthropology Morphology Tianyuan man is considered an early modern homo sapiens. He lacks several mandibular features common among western Eurasian late archaic humans, showing its divergence. Based on the rate of dental occlu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Last Glacial Maximum
The Last Glacial Maximum (LGM), also referred to as the Last Glacial Coldest Period, was the most recent time during the Last Glacial Period where ice sheets were at their greatest extent between 26,000 and 20,000 years ago. Ice sheets covered much of Northern North America, Northern Europe, and Asia and profoundly affected Earth's climate by causing a major expansion of deserts, along with a large drop in sea levels. Based on changes in position of ice sheet margins dated via cosmogenic nuclide, terrestrial cosmogenic nuclides and radiocarbon dating, growth of ice sheets in the southern hemisphere commenced 33,000 years ago and maximum coverage has been estimated to have occurred sometime between 26,500 years ago and 20,000 years ago. After this, deglaciation caused an abrupt rise in sea level. Decline of the West Antarctica ice sheet occurred between 14,000 and 15,000 years ago, consistent with evidence for another abrupt rise in the sea level about 14,500 years ago. Glacier fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Northern East Asian
In archaeogenetics, the term Ancient Northern East Asian (ANEA), also known as Northern East Asian (NEA), is used to summarize the related ancestral components that represent the Ancient Northern East Asian peoples, extending from the Baikal region to the Yellow River and the Qinling-Huaihe Line in present-day central China. They are inferred to have diverged from Ancient Southern East Asians (ASEA) around 20,000 to 26,000 BCE. The ANEA can be differentiated into broadly three sub-groups, namely the “Ancient Northeast Asians“ (ANA), “Neo-Siberians", and "Yellow River farmers". The ANEA are to be distinguished from the derived and namely similar "Ancient Northeast Asian" (ANA) lineage, which is alternatively also known as "Amur ancestry", and which forms a sub-group of the ANEA grouping, specifically ancestral to hunter-gatherer people of the 7th-4th millennia before present, in the Amur region and later expanding to far-eastern Siberia, Mongolia and the Baikal regions, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shovel-shaped Incisors
Shovel-shaped incisors (or, more simply, shovel incisors) are incisors whose Glossary of dentistry, lingual surfaces are scooped as a consequence of lingual marginal ridges, Crown (tooth), crown curvature, or Basal (anatomy), basal Tubercle (anatomy), tubercles, either alone or in combination. Shovel-shaped incisors are significantly common in Indigenous peoples of the Americas, Amerindians from North America, North, Central America, Central, and South America. They are also common in East Asians and Central Asians, Inuit, and Aleut peoples of Siberian Yupik, Northeast Asia and North America (including but not limited to Inuit in eastern Alaska, Northern Canada, Arctic Canada, and Greenland). In certain European peoples, European and Demographics of Africa, African groups, shovel-shaped upper incisors are uncommon or not present. There is a spectrum of the degree of shoveled-ness, ranging on a scale from 0 to 7 of spatulate incisors to shoveled incisors. It was theorized that pos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
