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Ectodysplasin A Receptor
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 densit ... [...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 residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 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 peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethnic Groups Of Africa
The ethnic groups of Africa number in the thousands, with each population generally having its 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, both due to limited infrastructure to perform censuses and due to the rapid population growth. There have also been accusations of 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 ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell-surface Receptors
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 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 peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residues ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectodysplasin A2 Receptor
Tumor necrosis factor receptor superfamily member 27 is a protein that in humans is encoded by the ''EDA2R'' gene. EDA-A1 and EDA-A2 are two isoforms of ectodysplasin that are encoded by the anhidrotic ectodermal dysplasia (EDA) gene. Mutations in EDA give rise to a clinical syndrome characterized by loss of hair, sweat glands, and teeth. The protein encoded by this gene specifically binds to EDA-A2 isoform. This protein is a type III transmembrane protein of the TNFR (tumor necrosis factor receptor) superfamily, and contains 3 cysteine Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula . The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile. When present as a deprotonated catalytic residue, sometime ...-rich repeats and a single transmembrane domain but lacks an N-terminal signal peptide. Multiple alternatively spliced transcript variants have been found for this gene, but some variants lack suffici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lapa Do Santo
Lapa do Santo is an archaeological site located in the northern part of the Lagoa Santa karst, in the state of Minas Gerais in east-central Brazil. It documents human presence since ca. 12000 years ago presenting three discrete occupation phases that correspond to the early, middle and late Holocene. Llithic technology, zooarchaeology, and multi- isotopic analyses indicate groups of hunter gathers with low mobility and a subsistence strategy focused on gathering plant foods and hunting small and mid-sized mammals. The use of Lapa do Santo as an interment ground started between 10.3-10.6 cal kyBP with primary burials. Between 9.4-9.6 cal kyBP central elements in the treatment of the dead were tooth removal, mutilation, defleshing, exposure to fire and possibly cannibalism, all to reduce the body ahead of reburial of the remains while adhering to strict rules. In the absence of monumental architecture or grave goods, these groups were using parts of fresh corpses to elaborate th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anzick-1
Anzick-1 is a Paleo-Indian male infant whose remains were found in south central Montana, United States, in 1968, and date to 13,000–12,850 years BP. The child was found with more than 115 tools made of stone and antlers and dusted with red ocher, suggesting an honorary burial. Anzick-1 is the only human who has been discovered from the Clovis Complex, and is the first ancient Native American genome to be fully sequenced. Paleogenomic analysis of the remains revealed Siberian ancestry and a close genetic relationship to modern Native Americans, including those of Central and South America. These findings support the hypothesis that modern Native Americans are descended from Asian populations who crossed Beringia between 23,000 and 14,000 years ago. Anzick-1's discovery and subsequent analysis has been controversial. The remains were found on private land, so compliance with the Native American Graves Protection and Repatriation Act (NAGPRA) was not required in their study. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upward Sun River Site
The Upward Sun River site, or Xaasaa Na’, is a Late Pleistocene archaeological site associated with the Paleo-Arctic tradition, located in the Tanana River Valley, Alaska. Dated to around 11,500 BP, Upward Sun River is the site of the oldest human remains discovered on the American side of Beringia. The site was first discovered in 2006. The layer with the human remains at Upward Sun River is most similar to the level 6 layer from Ushki Lake, Kamchatka. Both sites are the only Beringian burials found so far from that period. Etymology The name of the site, Upward Sun River, is a direct translation of the Middle Tanana name for the site, ''Xaasaa Na’''. The Middle Tanana name was recorded from the mother of a mother-daughter pair, two of the last remaining speakers of Middle Tanana, during an interview in the 1960s. Human remains The first excavation at Upward Sun River in 2010 yielded the cremated remains of a 3-year-old individual. The individual had been cremated insid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scythian
The Scythians or Scyths, and sometimes also referred to as the Classical Scythians and the Pontic Scythians, were an ancient Eastern * : "In modern scholarship the name 'Sakas' is reserved for the ancient tribes of northern and eastern Central Asia and Eastern Turkestan to distinguish them from the related Massagetae of the Aral region and the Scythians of the Pontic steppes. These tribes spoke Iranian languages, and their chief occupation was nomadic pastoralism." * : "Near the end of the 19th century V.F. Miller (1886, 1887) theorized that the Scythians and their kindred, the Sauromatians, were Iranian-speaking peoples. This has been a popular point of view and continues to be accepted in linguistics and historical science .. * : "From the end of the 7th century B.C. to the 4th century B.C. the Central- Eurasian steppes were inhabited by two large groups of kin Iranian-speaking tribes – the Scythians and Sarmatians .. * : "All contemporary historians, archeologists and li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afanasevo Culture
The Afanasievo culture, or Afanasevo culture (Afanasevan culture) (russian: Афанасьевская культура ''Afanas'yevskaya'' kul'tura), is the earliest known archaeological culture of south Siberia, occupying the Minusinsk Basin and the Altai Mountains during the eneolithic era, 3300 to 2500 BCE. It is named after a nearby mountain, Gora Afanasieva () in what is now Bogradsky District, Khakassia, Russia. David W. Anthony believes that the Afanasevan population was descended from people who migrated c. 3700–3300 BCE across the Eurasian Steppe from the pre- Yamnaya Repin culture of the Don-Volga region. Because of its geographical location and dating, Anthony and earlier scholars such as Leo Klejn, J. P. Mallory and Victor H. Mair have linked the Afanasevans to the Proto-Tocharian language. Dating Conventional archaeological understanding tended to date at around 2000–2500 BC. However radiocarbon gave dates as early as 3705 BC on wooden tools and 287 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motala
Motala () is a locality and the seat of Motala Municipality, Östergötland County, Sweden with 29,823 inhabitants (41,956 in the entire municipality) in 2010. It is the third largest city of Östergötland, following Linköping and Norrköping. Motala is situated on the eastern shore of Lake Vättern and is regarded as the main centre of both the Göta Canal and the surrounding lake region. History Motala Church dates from the 13th century. For several centuries, Motala remained a small village, mainly regarded as a stopping post on the road to the nearby town of Vadstena, one of the cultural centres of medieval Sweden. However, King Gustav Vasa had a manor house built at Motala and later Queen Kristina had a summer residence built at the spa resort of Medevi, 20 km north of the town. When the Göta Canal was built in the early 19th century, Motala became an important town for the trade on the canal. The builder of the canal, Baltzar von Platen, has his grave beside it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin D
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). The major natural source of the vitamin is synthesis of cholecalciferol in the lower layers of epidermis of the skin through a chemical reaction that is dependent on sun exposure (specifically UVB radiation). Cholecalciferol and ergocalciferol can be ingested from the diet and supplements. Only a few foods, such as the flesh of fatty fish, naturally contain significant amounts of vitamin D. In the U.S. and other countries, cow's milk and plant-derived milk substitutes are fortified with vitamin D, as are many breakfast cereals. Mushrooms exposed to ultraviolet light contribute useful amounts of vitamin D2. Dietary recommendations typically assume that all of a person's vitamin D is taken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
