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Gale–Shapley algorithm
Since B is a stable matching, m2 must be matched in B to some woman he prefers to w1, say w3. This means that in A, m2 has visited w3 before arriving at w1, which means that w3 has rejected him. By similar considerations, and since the graph is finite, we must eventually have a directed cycle in which each man was reje...
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Strategic considerations The GS algorithm is a truthful mechanism from the point of view of men (the proposing side). I.e, no man can get a better matching for himself by misrepresenting his preferences. Moreover, the GS algorithm is even group-strategy proof for men, i.e., no coalition of men can coordinate a misrepr...
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The GS algorithm is non-truthful for the women (the reviewing side): each woman may be able to misrepresent her preferences and get a better match.
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Gale–Shapley algorithm
Implementation in software packages R: The Gale–Shapley algorithm (also referred to as deferred-acceptance algorithm) for the stable marriage and the hospitals/residents problem is available as part of the matchingMarkets and matchingR packages. API: The MatchingTools API provides a free application programming interfa...
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Recognition Shapley and Roth were awarded 2012 Nobel Memorial Prize in Economic Sciences "for the theory of stable allocations and the practice of market design"; Gale had died in 2008. See also Deferred-acceptance auction References External links Gale–Shapley JavaScript Demonstration Stable matching Lloyd Shapley Alg...
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Andean civilizations
The Andean civilizations were complex societies of many cultures and peoples mainly developed in the river valleys of the coastal deserts of Peru. They stretched from the Andes of southern Colombia southward down the Andes to Chile and northwest Argentina. Archaeologists believe that Andean civilizations first develope...
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Despite severe environmental challenges, the Andean civilizations domesticated a wide variety of crops, some of which became of worldwide importance. The Andean civilizations were also noteworthy for monumental architecture, textile weaving, and many unique characteristics of the societies they created. Less than a ce...
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Spanish rule ended or transformed many elements of the Andean civilizations, notably influencing religion and architecture. Uniqueness The civilization of the Andes was one of five in the world deemed by scholars to be "pristine", that is indigenous and not derived from other civilizations. Due to its isolation from ot...
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Andean civilization lacked several characteristics distinguishing it from the pristine civilizations in the Old World and from the Mesoamerican cultures. First, and perhaps most important, Andean civilizations did not have a written language. Instead, their societies used the quipu, a system of knotted and colored str...
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Andean civilizations also lacked wheeled vehicles and draft animals. People on land traveled only by foot and the transport of goods was only by humans or llama, pack animals which could carry loads of up to one-fourth of their weight, a maximum of . Llamas were not big or strong enough to be used for plowing or as ri...
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Moreover, Andean civilizations faced severe environmental challenges. The earliest civilizations were on the hyper-arid desert coast of Peru. Agriculture was possible only with irrigation in valleys crossed by rivers coming from the high Andes, plus in a few fog oases called lomas. In the Andes, agriculture was limit...
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Finally, the Andean civilizations lacked money. Copper axe-monies (also called "naipes") and Spondylus shells functioned as mediums of exchange in some areas, especially coastal Ecuador, but most of the Andes area had economies organized on reciprocity and redistribution rather than money and markets. These characteris...
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Some scholars believe that the earliest civilizations on the Peruvian coast initially relied more upon maritime resources than agriculture during the formative period of their societies. However, as in all civilizations until the late 19th century, agriculture was the principal occupation of the great majority of the p...
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The challenges of the environment required sophisticated agricultural technology. Unlike the Middle East, the Andes lacked easily domesticated and large-seeded plants such as wheat and barley and large and easily domesticated animals such as horses and cattle. Agriculture on the desert coast required the development o...
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Archaeological cultures Caral
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The Norte Chico civilization, also called Caral, was a complex pre-Columbian society that included as many as 30 major population centers in what is now the Norte Chico region of north-central coastal Peru. It is the oldest known civilization in the Americas and one of the Cradles of civilization where civilization sep...
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Valdivia The Valdivia Culture is one of the oldest settled cultures recorded in the Americas. It emerged from the earlier Las Vegas culture and thrived on the Santa Elena peninsula near the modern-day town of Valdivia, Ecuador between 3500 BCE and 1800 BCE. Chavín
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The Chavín culture is thought to have been primarily a religious movement. The culture apparently began in the Peruvian highlands and then spread outward throughout the country. The Chavín culture has very distinctive art styles, particularly in effigy pots, a number of which were in feline shapes. Chavin de Huantar wa...
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The Nazca culture (also Nasca) was the archaeological culture that flourished from 100 to 800 CE beside the dry southern coast of Peru in the river valleys of the Rio Grande de Nazca drainage and the Ica Valley (Silverman and Proulx, 2002). Having been heavily influenced by the preceding Paracas culture, which was know...
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Moche
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The Moche civilization (alternately, the Mochica culture, Early Chimu, Pre-Chimu, Proto-Chimu, etc.) flourished in northern Peru from about 100 CE to 800 CE, during the Regional Development Epoch. While this issue is the subject of some debate, many scholars contend that the Moche were not politically organized as a mo...
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Chachapoyas The Chachapoyas, or the 'Cloud people', were an Andean civilization living in a cloud forests of the Amazonas region of present-day northern Peru. The Incas conquered the Chachapoyas shortly before the arrival of the Spanish in Peru. The first firm evidence of their existence dates back to around 700 CE, al...
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The Wari () were a Middle Horizon civilization that flourished in the south-central Andes and coastal area of Peru, from about CE 500 to 1000. (The Wari culture is not to be confused with the modern ethnic group and language known as Wari', with which it has no known link.) Wari, as the former capital city was called, ...
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Tiwanaku
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Tiwanaku (Spanish: Tiahuanaco and Tiahuanacu) is an important Pre-Columbian archaeological site in western Bolivia, South America. Tiwanaku is recognized by Andean scholars as one of the most important precursors to the Inca Empire, flourishing as the ritual and administrative capital of a major state power for approxi...
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Historical cultures Chimú The Chimú were the residents of Chimor, with its capital at the city of Chan Chan, a large adobe city in the Moche Valley of present-day Trujillo, Peru. The culture arose about 900 CE. The Inca ruler Topa Inca Yupanqui led a campaign which conquered the Chimú around 1470 CE.
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This was just fifty years before the arrival of the Spanish in the region. Consequently, Spanish chroniclers were able to record accounts of Chimú culture from individuals who had lived before the Inca conquest. Similarly, archaeological evidence suggest Chimor grew out of the remnants of Moche culture; early Chimú po...
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The Inca Empire, or Incan Empire (Quechua: Tawantinsuyu), was the largest empire in pre-Columbian America. The administrative, political and military center of the empire was located in Cusco. The Inca civilization arose from the Peruvian highlands sometime in the early 13th century, and the last Inca stronghold was co...
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Muisca
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The Muisca was the Chibcha-speaking people that formed the Muisca Confederation in the central highlands of present-day Colombia. They were encountered by the troops of Gonzalo Jiménez de Quesada, in name of the Spanish Empire at the time of the conquest in the spring of 1537. The Muisca comprised two confederations: H...
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Timoto-Cuica
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Timoto–Cuica people was composed primarily of two tribes, the Timotes and the Cuicas, that inhabited in the Andean region of western Venezuela. They were closely related to the Muisca people of the Andes, who spoke a Chibcha language. The Timoto-Cuicas were not only composed of the Timoto and the Cuica tribes, but also...
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See also History of Argentina History of Bolivia History of Chile History of Colombia History of Ecuador History of Peru Periodization of Pre-Columbian Peru Amazonas before the Inca Empire Guaman Poma Pambokancha, religious site Population history of American indigenous peoples Tumi Quechua people Kogi peo...
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Further reading Besom, Thomas. Of Summits and Sacrifice: An Ethnohistoric Study of Inka Religious Practices (University of Texas Press; 2010) 230 pages; combines archaeological and textual data in study of practices of human sacrifice and mountain worship. Burger, Richard L. Machu Picchu; Unveling the Mystery of the ...
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External links Peru Cultural Society Inca Emuseum @ Minnesota State University Peruvian National Museum of Archaeology, Anthropology, and History Civilizations Hill people
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National Center for Charitable Statistics
The National Center for Charitable Statistics (NCCS) is a clearing house for information about the nonprofit sector of the U.S. economy. The National Center for Charitable Statistics builds national, state, and regional databases and develops standards for reporting on the activities of all tax-exempt organizations. Se...
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National Center for Charitable Statistics
When the Electronic Data Initiative for Nonprofits Coalition was formed in 2002, the National Center for Charitable Statistics advised the group in furtherance of the goal of integrated federal and state electronic reporting and dissemination of data on nonprofit organizations. GuideStar works with the National Center ...
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National Center for Charitable Statistics
History The National Center for Charitable Statistics was established on March 15, 1982, as a research division of Independent Sector. Russy Sumariwalla was the first executive director of the National Center for Charitable Statistics. Prior to its establishment, no one knew exactly how many nonprofit organizations exi...
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National Center for Charitable Statistics
The National Center for Charitable Statistics, along with several other nonprofit organizations, was instrumental in creating the National Taxonomy of Exempt Entities classification system or NTEE Codes. The National Taxonomy of Exempt Entities classifies organizations into more than 100 different categories based on t...
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List of power stations in Iran
By 2012, Iran had roughly 400 power plant units. By the end of 2013, Iran had a total installed electricity generation capacity of 70,000 MW, which had been increased from 90 MW in 1948, and 7024 MW in 1978. It is planned to add more than 5,000 MW of generation capacity annually to the power grid, which will almost do...
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List of power stations in Iran
It was predicted Iran accounts for 17.08% of MENA power generation by 2014. The natural gas was the major fuel used to generate electricity in Iran in 2009, accounting for an estimated 56.8% of primary energy demand (PED), followed by oil at 40.8% and hydro power at 1.4%. As of 2010, the average efficiency of power pla...
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Electricity generation in 2008, accounted for 203.8 billion kWh or roughly one percent of world's total production, which was increased by 5.9 percent comparing with the year before. In 2008, the total electricity generated was 190.2 billion kWh which 93.3% was generated by power plants affiliated with the Ministry of ...
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In 2010, 900,000 jobs were directly or indirectly related to the power industry in Iran. Currently, Iran's spares power capacity stands at 3 per cent, but this amount is much lower than the ideal 25 percent of peak power used. It has been estimated that 23.5 percent of the electricity generation is wasted in the transm...
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Electric power industry in Iran has become self-sufficient in producing the required equipment to build power plants. While most of the electricity generators are run by the government, the equipment producers and contractors are generally from the private sector. Iran is among the top ten manufacturers of gas turbines...
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Nuclear power plants Darkhovin Nuclear Power Plant is Iran's first indigenously designed and built power plant besides the research reactor of IR-40. Bushehr Nuclear Power Plant is Iran's first nuclear power plant and it has been manufactured with the technical assistance of Russia.
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International projects Iran is not only self-sufficient in power plant construction but has also concluded a number of contracts on implementing projects in neighboring states. As of 2010, Iranian energy and resource development firms are involved in 50 projects worth over USD 2.2 billion in more than 20 countries acro...
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One of Iran’s most important international projects will see the construction of a $200-million hydroelectric dam in Nicaragua starting 2011. Iran is currently engaged in dam construction in Tajikistan, Armenia and Azerbaijan, and consultations are underway with a number of other countries. Kenya, Sri Lanka, Bolivia an...
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Foreign direct investment According to the Ministry of Energy, Germany has invested $445 million in construction of the Pareh-Sar combined cycle power plant in northern Iran, while the UAE has invested $720 million in construction of a gas power plant as well as a combined cycle power plant in Isfahan and Shiraz. In 20...
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Mapna Company. Sahand, Bistoun, Shazand, Shahid Montazeri, Tous, Shahid Rajaei and Neishabour power stations are among the profit-making plants, work on privatizing them will be finalized by late March 2007. Jahrom, Khalij-e Fars (Persian Gulf) and Sahand power plants will be ceded to the private sector in 2009. All do...
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Energy/electricity bourse The new energy/electricity bourse will be inaugurated in 2012. This will bring about more competition and transparency in Iran’s electricity market. Experts believe that following the launch of the subsidies reform plan, the electricity industry will undergo significant changes and will become...
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As at 2012, Iran had over 400 power plant units and 38 electricity distribution companies which buy the electricity from producers. Iran has over 100 companies which consume more than 20 MW of electricity per year. The average price of each kilowatt of electricity is 450 rials (around 5 cents) during the first phase of...
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Iran's electricity export and related technical and engineering services exports was valued at $4 billion in 2011. In 2010, the total of Iran’s electricity exports to Afghanistan, Iraq (650 MW), Azerbaijan, Armenia, Pakistan and Turkey reached 878 megawatts and the total of imports from Armenia (237 MW) and Turkmenista...
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In service With about 300 clear sunny days a year and an average of 2,200 kilowatt-hour solar radiation per square meter, Iran has a great potential to tap solar energy. Under construction Tidal and wave power Wind Others
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Decentralized power generation In addition to the above power plants, there was 1800 MW cumulative installed capacity in 2011, which belonged to small scale decentralized power plants, some of which were not connected to the national grid, and many being privately built and run. This capacity is planned for increase to...
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External links Iran Water & Power Development Company List of dams in Iran Tavanir - Iran's Electric Power Generation Organization Energy Exchange of Iran Specialized reports Iran Power Market Outlook to 2030, 55-page report, 2012 Iran power, 57-page report, 2010 Thermal Power Market Outlook in Iran to 2020, 78-...
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Osteochondroprogenitor cell
Osteochondroprogenitor cells are progenitor cells that arise from mesenchymal stem cells (MSC) in the bone marrow. They have the ability to differentiate into osteoblasts or chondrocytes depending on the signalling molecules they are exposed to, giving rise to either bone or cartilage respectively. Osteochondroprogenit...
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Osteochondroprogenitor cell
Discovery Alexander Friedenstein and his colleagues first identified osteoprogenitor cells in multiple mammalian tissues, before any genetic or morphological criteria were put in place for bone marrow or connective tissues. Osteoprogenitor cells can be identified by their associations with existing bone or cartilage st...
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Osteochondroprogenitor cell
Cell signalling and differentiation Osteochondroprogenitor can be found between MSCs and the terminally differentiated osteoblasts and chondrocytes. Via different signalling molecules and combinations the osteochondroprogenitor will differentiate into either osteoblasts or chondrocytes. Differentiation into chondrocyte...
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Osteochondroprogenitor cell
Chondrocytes are only present in cartilage where they will produce cartilaginous matrix to maintain the structure. Sox9, L-Sox5 and Sox6 are needed for the osteochondroprogenitor to undergo chondrocytic differentiation. The transcription factor Sox9 can be found in multiple sites in the body (pancreas, central nervous ...
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Osteochondroprogenitor cell
Osteoblasts are cells that group together to form units, called osteons, to produce bone. Runx2 (which may also be known as Cbfa1), and Osx (a zinc finger containing transcription factor) are necessary for osteochondroprogenitor cells to differentiate into the osteoblast cell lineage. These factors also have a role in ...
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β-catenin of the canonical Wnt signalling pathway plays a role in cell fate determination, as it is critical for osteoblastogenesis, and the differentiation of chondrocytes into osteoblasts. Knock out of the entire pathway results in early embryonic death, therefore most research of this nature utilised conditional kno...
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During mandible development, most of it is formed through intramembranous ossification, where endochondral ossification will occur in the proximal region. TGF-β is important for cell proliferation and differentiation during skeletogenesis. During this process, TGF-β can stimulate differentiation into either chondrocyte...
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TGF-β determines and regulates cell lineages during endochondral ossification through Sox9 and Runx2 signalling pathways. TGF-β will act as a stimulator of chondrogenesis, and an inhibitor of osteoblastic differentiation, by blocking the Runx2 factor through Smad3 activation. Sox9 stimulates differentiation into chondr...
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Loss of TGF-β signalling will lead to reduced Sox9 activity, but not prevent it completely, suggesting that there must be other factors and signalling pathways regulating Sox9 activity. Once Sox9 activity is lost, differentiation into the osteoblastic lineage dominates.
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Embryonic development It is thought that through a combination of biochemical and biophysical stimuli, the uncommitted stem cells of the embryo will undergo differentiation into certain cell lineages. However the exact mechanism and signalling pathways are still unclear. Studies have shown that embryonic stem cells are...
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Osteoprogenitor cell condensations can aggregate, dissipate or condense depending on the signals present, however these still remain largely unknown. Depending on the different effects, the cellular condensations may differentiate into osteogenic or chondrocytic condensations.
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The positioning of the osteoprogenitor cell condensations determines the cell lineage before the signalling molecules can. This is due to their positions relative to any epithelial surfaces. Osteoblastic and chondrogenic condensations differ in their biophysical parameters within the embryo. Their distance in relation ...
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Osteochondroprogenitor cell
Consequence of defects in osteochondroprogenitor cells
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Osteochondroprogenitor cell
Deletion of the Trsp gene in osteochondroprogenitor cells results in abnormal bone growth, delayed ossification, chondronecrosis and dwarfism. General Trsp gene deletion is lethal to the embryo. The results of this research was used as a model for Kashin-Beck disease. Kashin-Beck is a result of combinatorial environmen...
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Osteochondroprogenitor cell
Loss of the regulator, Pten, of the Phophatidylinositol3’ kinase pathway results in skeletal overgrowth and growth plate dysfunction, due to overproduction of the matrix and accelerated hypertrophic differentiation. See also List of human cell types derived from the germ layers References Skeletal disorders Congenita...
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Yazd Solar Power Station
The Yazd Solar Power Station is an integrated solar combined cycle (ISCC) power station situated near Yazd, Iran which became operational in 2009, and in 2011 as a solar integrated plant. The plant has a capacity of 467 MW and uses solar energy to augment its steam generation by concentrating solar power technology. Se...
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Shiraz Solar Power Plant
Shiraz Solar Power Plant is a concentrating solar power type pilot power station situated near Shiraz, Iran. It became operational in 2008. The plant uses concentrating parabolic mirrors to focus a beam of light on a tower making steam for electricity generating turbines. It has a capacity of 250 kilowatt (kW). It is ...
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Shiraz Solar Power Plant
Solar power stations in Iran Buildings and structures in Fars Province
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Cell potency
Cell potency is a cell's ability to differentiate into other cell types. The more cell types a cell can differentiate into, the greater its potency. Potency is also described as the gene activation potential within a cell, which like a continuum, begins with totipotency to designate a cell with the most differentiation...
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Cell potency
Totipotency Totipotency (Lat. totipotentia, "ability for all [things]") is the ability of a single cell to divide and produce all of the differentiated cells in an organism. Spores and zygotes are examples of totipotent cells. In the spectrum of cell potency, totipotency represents the cell with the greatest differenti...
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A fully differentiated cell can return to a state of totipotency. The conversion to totipotency is complex and not fully understood. In 2011, research revealed that cells may differentiate not into a fully totipotent cell, but instead into a "complex cellular variation" of totipotency. Stem cells resembling totipotent ...
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The human development model can be used to describe how totipotent cells arise. Human development begins when a sperm fertilizes an egg and the resulting fertilized egg creates a single totipotent cell, a zygote. In the first hours after fertilization, this zygote divides into identical totipotent cells, which can late...
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Research on Caenorhabditis elegans suggests that multiple mechanisms including RNA regulation may play a role in maintaining totipotency at different stages of development in some species. Work with zebrafish and mammals suggest a further interplay between miRNA and RNA-binding proteins (RBPs) in determining developmen...
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In mouse primordial germ cells, genome-wide reprogramming leading to totipotency involves erasure of epigenetic imprints. Reprogramming is facilitated by active DNA demethylation involving the DNA base excision repair enzymatic pathway. This pathway entails erasure of CpG methylation (5mC) in primordial germ cells vi...
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Pluripotency
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In cell biology, pluripotency (Lat. pluripotentia, "ability for many [things]") refers to a stem cell that has the potential to differentiate into any of the three germ layers: endoderm (interior stomach lining, gastrointestinal tract, the lungs), mesoderm (muscle, bone, blood, urogenital), or ectoderm (epidermal tissu...
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Induced pluripotency
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Induced pluripotent stem cells, commonly abbreviated as iPS cells or iPSCs, are a type of pluripotent stem cell artificially derived from a non-pluripotent cell, typically an adult somatic cell, by inducing a "forced" expression of certain genes and transcription factors. These transcription factors play a key role in ...
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Epigenetic factors are also thought to be involved in the actual reprogramming of somatic cells in order to induce pluripotency. It has been theorized that certain epigenetic factors might actually work to clear the original somatic epigenetic marks in order to acquire the new epigenetic marks that are part of achievi...
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Due to their great similarity to ESCs, the medical and research communities are interested iPSCs. iPSCs could potentially have the same therapeutic implications and applications as ESCs but without the controversial use of embryos in the process, a topic of great bioethical debate. The induced pluripotency of somatic c...
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Somatic expression of combined transcription factors can directly induce other defined somatic cell fates (transdifferentiation); researchers identified three neural-lineage-specific transcription factors that could directly convert mouse fibroblasts (skin cells) into fully functional neurons. This result challenges th...
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Some of the possible medical and therapeutic uses for iPSCs derived from patients include their use in cell and tissue transplants without the risk of rejection that is commonly encountered. iPSCs can potentially replace animal models unsuitable as well as in vitro models used for disease research. Naive vs. primed plu...
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Findings with respect to epiblasts before and after implantation have produced proposals for classifying pluripotency into two distinct phases: "naive" and "primed". The baseline stem cells commonly used in science that are referred as embryonic stem cells (ESCs) are derived from a pre-implantation epiblast; such epibl...
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Another major difference that was observed, with respect to cell potency, is that post-implantation epiblast stem cells are unable to contribute to blastocyst chimeras, which distinguishes them from other known pluripotent stem cells. Cell lines derived from such post-implantation epiblasts are referred to as epiblast-...
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Native pluripotency in plants Un-induced pluripotency has been observed in root meristem tissue culture, especially by Kareem et al 2015, Kim et al 2018, and Rosspopoff et al 2017. This pluripotency is regulated by various regulators, including PLETHORA 1 and PLETHORA 2; and PLETHORA 3, PLETHORA 5, and PLETHORA 7, whos...
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Multipotency Multipotency is when progenitor cells have the gene activation potential to differentiate into discrete cell types. For example, a multipotent blood stem cell —and this cell type can differentiate itself into several types of blood cell like lymphocytes, monocytes, neutrophils, etc., but it is still ambigu...
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Research related to multipotent cells suggests that multipotent cells may be capable of conversion into unrelated cell types. In another case, human umbilical cord blood stem cells were converted into human neurons. There is also research on converting multipotent cells into pluripotent cells. Multipotent cells are fou...
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MSCs may prove to be a valuable source for stem cells from molars at 8–10 years of age, before adult dental calcification. MSCs can differentiate into osteoblasts, chondrocytes, and adipocytes.
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Oligopotency In biology, oligopotency is the ability of progenitor cells to differentiate into a few cell types. It is a degree of potency. Examples of oligopotent stem cells are the lymphoid or myeloid stem cells. A lymphoid cell specifically, can give rise to various blood cells such as B and T cells, however, not t...
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In cell biology, a unipotent cell is the concept that one stem cell has the capacity to differentiate into only one cell type. It is currently unclear if true unipotent stem cells exist. Hepatoblasts, which differentiate into hepatocytes (which constitute most of the liver) or cholangiocytes (epithelial cells of the bi...
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Read code
Read codes are a clinical terminology system that was in widespread use in General Practice in the United Kingdom until around 2018, when NHS England switched to using SNOMED CT. Read codes are still in use in Scotland and in England are permitted for use in NHS secondary care settings, such as dentistry and mental hea...
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Read code
History Since its origins in the 1980s, the system has evolved through three major technical design changes and significantly expanded its content.
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Read code
Read version 1 (4-byte Read) The first version was developed in the early 1980s by Dr James Read, a Loughborough general medical practitioner. The scheme was structured similarly to ICD-9: each code was composed of four consecutive characters: first character 0-9, A-Z (excepting I and O), remaining three characters 0-...
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Read code
Because of its four character code structure, Read Codes version 1 was more commonly known as 4-Byte Read. The first release was in April 1986; the final official release of 4-Byte Read occurred in April 2009.
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Read version 2 (5-byte Read) 4-Byte Read could only encode a monoaxial hierarchy with a maximum of 4 hierarchical levels. The operational NHS requirement to provide a direct crossmap to both ICD-9-CM and OPCS-4 implied an additional hierarchical level was required. Accordingly, a new scheme was devised with exactly the...
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