title: Arabic numerals

text: Al-Nasawi wrote in the early 11th century that mathematicians had not agreed on the form of the numerals, but most of them had agreed to train themselves with the forms now known as Eastern Arabic numerals. The oldest specimens of the written numerals available are from Egypt and date to 873–874 CE. They show three forms of the numeral "2" and two forms of the numeral "3", and these variations indicate the divergence between what later became known as the Eastern Arabic numerals and the Western Arabic numerals. The Western Arabic numerals came to be used in the Maghreb and Al-Andalus from the 10th century onward. Some amount of consistency in the Western Arabic numeral forms endured from the 10th century, found in a Latin manuscript of Isidore of Seville's "Etymologiae" from 976 and the Gerbertian abacus, into the 12th and 13th centuries, in early manuscripts of translations from the city of Toledo.


title: Arabic numerals

text: Calculations were originally performed using a dust board ("takht", Latin: "tabula"), which involved writing symbols with a stylus and erasing them. The use of the dust board appears to have introduced a divergence in terminology as well: whereas the Hindu reckoning was called "ḥisāb al-hindī" in the east, it was called "ḥisāb al-ghubār" in the west (literally, "calculation with dust"). The numerals themselves were referred to in the west as "ashkāl al‐ghubār" ("dust figures") or "qalam al-ghubår" ("dust letters"). Al-Uqlidisi later invented a system of calculations with ink and paper "without board and erasing" ("bi-ghayr takht wa-lā maḥw bal bi-dawāt wa-qirṭās").


title: Arabic numerals

text: A popular myth claims that the symbols were designed to indicate their numeric value through the number of angles they contained, but no evidence exists of this, and the myth is difficult to reconcile with any digits past 4.


title: Arabic numerals

text: The first mentions of the numerals from 1 to 9 in the West are found in the "Codex Vigilanus" of 976, an illuminated collection of various historical documents covering a period from antiquity to the 10th century in Hispania. Other texts show that numbers from 1 to 9 were occasionally supplemented by a placeholder known as "sipos", represented as a circle or wheel, reminiscent of the eventual symbol for zero. The Arabic term for zero is "sifr" (), transliterated into Latin as "cifra", and the origin of the English word "cipher".


title: Arabic numerals

text: From the 980s, Gerbert of Aurillac (later, Pope Sylvester II) used his position to spread knowledge of the numerals in Europe. Gerbert studied in Barcelona in his youth. He was known to have requested mathematical treatises concerning the astrolabe from Lupitus of Barcelona after he had returned to France.


title: Arabic numerals

text: The reception of Arabic numerals in the West was gradual and lukewarm, as other numeral systems circulated in addition to the older Roman numbers. As a discipline, the first to adopt Arabic numerals as part of their own writings were astronomers and astrologists, evidenced from manuscripts surviving from mid-12th-century Bavaria. Reinher of Paderborn (1140–1190) used the numerals in his calendrical tables to calculate the dates of Easter more easily in his text "Compotus emendatus".


title: Arabic numerals

text: Fibonacci, a mathematician from the Republic of Pisa who had studied in Béjaïa (Bugia), Algeria, promoted the Hindu-Arabic numeral system in Europe with his 1202 book "Liber Abaci:"


title: Arabic numerals

text: When my father, who had been appointed by his country as public notary in the customs at Bugia acting for the Pisan merchants going there, was in charge, he summoned me to him while I was still a child, and having an eye to usefulness and future convenience, desired me to stay there and receive instruction in the school of accounting. There, when I had been introduced to the art of the Indians' nine symbols through remarkable teaching, knowledge of the art very soon pleased me above all else and I came to understand it.


title: Arabic numerals

text: The "Liber Abaci" introduced the huge advantages of a positional numeric system, and was widely influential. As Fibonacci used the symbols from Béjaïa for the digits, these symbols were also introduced in the same instruction, ultimately leading to their widespread adoption.


title: Arabic numerals

text: Fibonacci's introduction coincided with Europe's commercial revolution of the 12th and 13th centuries, centered in Italy. Positional notation could be used for quicker and more complex mathematical operations (such as currency conversion) than Roman and other numeric systems could. They could also handle larger numbers, did not require a separate reckoning tool, and allowed the user to check a calculation without repeating the entire procedure. Although positional notation opened possibilities that were hampered by previous systems, late medieval Italian merchants did not stop using Roman numerals (or other reckoning tools). Rather, Arabic numerals became an additional tool that could be used alongside others.


title: Arabic numerals

text: In the late 14th century only a few texts using Arabic numerals appeared outside of Italy. This suggests that the use of Arabic numerals in commercial practice, and the significant advantage they conferred, remained a virtual Italian monopoly until the late 15th century. This may in part have been due to language – although Fibonacci's "Liber Abaci" was written in Latin, the Italian abacus traditions was predominantly written in Italian vernaculars that circulated in the private collections of abacus schools or individuals. It was likely difficult for non-Italian merchant bankers to access comprehensive information.


title: Arabic numerals

text: The European acceptance of the numerals was accelerated by the invention of the printing press, and they became widely known during the 15th century. Their use grew steadily in other centers of finance and trade such as Lyon. Early evidence of their use in Britain includes: an equal hour horary quadrant from 1396, in England, a 1445 inscription on the tower of Heathfield Church, Sussex; a 1448 inscription on a wooden lych-gate of Bray Church, Berkshire; and a 1487 inscription on the belfry door at Piddletrenthide church, Dorset; and in Scotland a 1470 inscription on the tomb of the first Earl of Huntly in Elgin Cathedral. In central Europe, the King of Hungary Ladislaus the Posthumous, started the use of Arabic numerals, which appear for the first time in a royal document of 1456.


title: Arabic numerals

text: By the mid-16th century, they were in common use in most of Europe. Roman numerals remained in use mostly for the notation of Anno Domini years, and for numbers on clock faces. Other digits (such as Eastern Arabic) were virtually unknown.


title: Arabic numerals

text: Prior to the introduction of Arabic numerals, Cyrillic numerals, derived from the Cyrillic alphabet, were used by South and East Slavic peoples. The system was used in Russia as late as the early 18th century, although it was formally replaced in official use by Peter the Great in 1699. Reasons for Peter's switch from the alphanumerical system are believed to go beyond his desire to imitate the West. Historian Peter Brown makes arguments for sociological, militaristic, and pedagogical reasons for the change. At a broad, societal level, Russian merchants, soldiers, and officials increasingly came into contact with counterparts from the West and became familiar with the communal use of Arabic numerals. Peter the Great also travelled incognito throughout Northern Europe from 1697 to 1698 during his Grand Embassy and was likely exposed to Western mathematics, if informally, during this time. The Cyrillic numeric system was also inferior in terms of calculating properties of objects in motions, such as the trajectories and parabolic flight patterns of artillery. It was unable to keep pace with Arabic numerals in the growing science of ballistics, whereas Western mathematicians such as John Napier had been publishing on the topic since 1614.


title: Arabic numerals

text: Chinese numeral systems that used positional notation (such as the counting rod system and Suzhou numerals) were in use in China previous to the introduction of Arabic numerals, some were introduced to medieval China by the Muslim Hui people. In the early 17th century, European-style Arabic numerals were introduced by Spanish and Portuguese Jesuits.


title: Arabic numerals

text: The ten Arabic numerals are encoded in virtually every character set designed for electric, radio, and digital communication, such as Morse code.


title: Arabic numerals

text: They are encoded in ASCII at positions 0x30 to 0x39. Masking to the lower four binary bits (or taking the last hexadecimal digit) gives the value of the digit, a great help in converting text to numbers on early computers. These positions were inherited in Unicode. EBCDIC used different values, but also had the lower 4 bits equal to the digit value.


title: Prime Minister of Canada

text: The prime minister of Canada () is the head of government of Canada. Under the Westminster system, the prime minister governs with the confidence of a majority the elected House of Commons; as such, the prime minister typically sits as a member of Parliament (MP) and leads the largest party or a coalition of parties. As first minister, the prime minister selects ministers to form the Cabinet, and serves as its chair. Constitutionally, the Crown exercises executive power on the advice of the Cabinet, which is collectively responsible to the House of Commons.


title: Prime Minister of Canada

text: Justin Trudeau is the 23rd and current prime minister of Canada. He took office on November 4, 2015, following the 2015 federal election where his Liberal Party won a majority of seats and was invited to form the 29th Canadian Ministry. Trudeau was subsequently re-elected following the 2019 and 2021 elections with a minority of seats.


title: Prime Minister of Canada

text: Not outlined in any constitutional document, the office exists only per long-established convention (originating in Canada's former colonial power, the United Kingdom) that stipulates the monarch's representative, the governor general, must select as prime minister the person most likely to command the confidence of the elected House of Commons; this individual is typically the leader of the political party that holds the largest number of seats in that chamber. Canadian prime ministers are appointed to the Privy Council and styled as the Right Honourable (), a privilege maintained for life.


title: Prime Minister of Canada

text: The prime minister is supported by the Prime Minister's Office and heads the Privy Council Office. The prime minister also effectively appoints individuals to the Senate of Canada and to the Supreme Court of Canada and other federal courts, along with choosing the leaders and boards, as required under law, of various Crown corporations. Under the "Constitution Act, 1867", government power is vested in the monarch (who is the head of state), but in practice the role of the monarch—or their representative, the governor general (or the administrator)—is largely ceremonial and only exercised on the advice of a Cabinet minister. The prime minister also provides advice to the monarch of Canada for the selection of the governor general.


title: Prime Minister of Canada

text: The position of prime minister is not outlined in any Canadian constitutional document and is mentioned only in passing in the "Constitution Act, 1982", and the "Letters Patent, 1947" issued by King George VI. The office and its functions are instead governed by constitutional conventions and modelled on the same office in the United Kingdom.


title: Prime Minister of Canada

text: The prime minister, along with the other ministers in Cabinet, is appointed by the governor general on behalf of the monarch. However, by the conventions of responsible government, designed to maintain administrative stability, the governor general will call to form a government the individual most likely to receive the support, or confidence, of a majority of the directly elected members of the House of Commons; as a practical matter, this is often the leader of a party whose members form a majority, or a very large plurality, of the House of Commons.


title: Prime Minister of Canada

text: While there is no legal requirement for prime ministers to be MPs themselves, for practical and political reasons the prime minister is expected to win a seat very promptly. However, in rare circumstances individuals who are not sitting members of the House of Commons have been appointed to the position of prime minister. Two former prime ministers—John Joseph Caldwell Abbott and Mackenzie Bowell—served in the 1890s while members of the Senate. Both, in their roles as Government Leader in the Senate, succeeded prime ministers who had died in office—John A. Macdonald in 1891 and John Sparrow David Thompson in 1894.


title: Prime Minister of Canada

text: Prime ministers who are not MPs upon their appointment (or who lose their seats while in office) have since been expected to seek election to the House of Commons as soon as possible. For example, William Lyon Mackenzie King, after losing his seat in the 1925 federal election (that his party won), briefly governed without a seat in the House of Commons before winning a by-election a few weeks later. Similarly, John Turner replaced Pierre Trudeau as leader of the Liberal Party in 1984 and subsequently was appointed prime minister while not holding a seat in the House of Commons; Turner won a riding in the next election but the Liberal Party was swept from power.


title: Prime Minister of Canada

text: When a prime minister loses their seat in the legislature, or should a new prime minister be appointed without holding a seat, the typical process that follows is that a member in the governing political party will resign to allow the prime minister to run in the resulting by-election. A safe seat is usually chosen; while the Liberal and Conservative parties generally observed a practice of not running a candidate against another party's new leader in the by-election, the New Democratic Party and smaller political parties typically do not follow the same practice. However, if the governing party selects a new leader shortly before an election is due, and that new leader is not a member of the legislature, they will normally await the upcoming election before running for a seat in Parliament.


title: Prime Minister of Canada

text: The prime minister serves "at Majesty's pleasure", meaning the post does not have a fixed term, and once appointed and sworn in by the governor general, the prime minister remains in office until they resign, are dismissed, or die.


title: Prime Minister of Canada

text: While the lifespan of a parliament is constitutionally limited to five years, a 2007 amendment to the "Canada Elections Act", Section 56.1(2) limited the term of a majority government to four years, with election day being set as the third Monday in October of the fourth calendar year after the previous polling date. The governor general may still, on the advice of the prime minister, dissolve parliament and issue the writs of election prior to the date mandated by the constitution or "Canada Elections Act"; the King–Byng Affair was the only time since Confederation that the governor general refused the prime minister's request for a general vote.


title: Prime Minister of Canada

text: Following parliamentary dissolution, the prime minister must run in the resulting general election to maintain a seat in the House of Commons. Should the prime minister's party subsequently win a majority of seats in the House of Commons, it is unnecessary to re-appoint the prime minister or for the prime minister to retake the oath of office. If, however, an opposition party wins a majority of seats, the prime minister may resign or be dismissed by the governor general. Should the prime minister's party achieve a minority while an opposition party wins a plurality (i.e., more seats than any other party but less than a majority), the prime minister can attempt to maintain the confidence of the House by forming a coalition with other minority parties, which was last entertained in 1925 or by entering into a confidence-and-supply agreement.


title: Prime Minister of Canada

text: Because the prime minister is in practice the most politically powerful member of the Canadian government, they are sometimes erroneously referred to as Canada's head of state, when, in fact, that role belongs to the Canadian monarch, represented by the governor general. The prime minister is, instead, the head of government and is responsible for advising the Crown on how to exercise much of the royal prerogative and its executive powers, which are governed by the constitution and its conventions. However, the function of the prime minister has evolved with increasing power. Today, per the doctrines of constitutional monarchy, the advice given by the prime minister is ordinarily binding, meaning the prime minister effectively carries out those duties ascribed to the sovereign or governor general, leaving the latter to act in predominantly ceremonial fashions. As such, the prime minister, supported by the Office of the Prime Minister (PMO), controls the appointments of many key figures in Canada's system of governance, including the governor general, the Cabinet, justices of the Supreme Court, senators, heads of Crown corporations, ambassadors and high commissioners, the provincial lieutenant governors, and approximately 3,100 other positions. Further, the prime minister plays a prominent role in the legislative process—with the majority of bills put before Parliament originating in the Cabinet—and the leadership of the Canadian Armed Forces.


title: Prime Minister of Canada

text: Pierre Trudeau is credited with, throughout his tenure as prime minister between 1968 and 1984, consolidating power in the PMO, which is itself filled by political and administrative staff selected at the prime minister's discretion and unaccountable to Parliament. At the end of the 20th century and into the 21st, analysts—such as Jeffrey Simpson, Donald Savoie, Andrew Coyne, and John Gomery—argued that both Parliament and the Cabinet had become eclipsed by prime ministerial power; Savoie wrote: "The Canadian prime minister has little in the way of institutional check, at least inside government, to inhibit his ability to have his way." Indeed, the position has been described as undergoing a "presidentialization", to the point that its incumbents publicly outshine the actual head of state (and prime minister's spouses are sometimes referred to as "First Lady of Canada"). Former governor general Adrienne Clarkson alluded to what she saw as "an unspoken rivalry" that had developed between the prime minister and the Crown. It has been theorized that such is the case in Canada as its Parliament is less influential on the executive than in other countries with Westminster parliamentary systems; particularly, Canada has fewer MPs, a higher turnover rate of MPs after each election, and a US-style system for selecting political party leaders, leaving them accountable to the party membership rather than caucus (as is the case in the UK).


title: Prime Minister of Canada

text: There do exist checks on the prime minister's power: the House of Commons may revoke its confidence in an incumbent prime minister and Cabinet or caucus revolts can quickly bring down a serving premier and even mere threats of such action can persuade or compel a prime minister to resign his post, as happened with Jean Chrétien. The "Reform Act, 2014", codifies the process by which a caucus may trigger a party leadership review and, if necessary, chose an interim leader, thereby making a prime minister more accountable to the MPs in his or her party. Caucuses may choose to follow these rules, though the decision would be made by recorded vote, thereby subjecting the party's choice to public scrutiny.


title: Prime Minister of Canada

text: The Senate may delay or impede legislation put forward by the Cabinet, such as when Brian Mulroney's bill creating the Goods and Services Tax (GST) came before the Senate, and given Canada's federal nature, the jurisdiction of the federal government is limited to areas prescribed by the constitution. Further, as executive power is constitutionally vested in the monarch, meaning the royal prerogative belongs to the Crown and not to any of its ministers, the sovereign's supremacy over the prime minister in the constitutional order is thus seen as a "rebuff to the pretensions of the elected: As it has been said, when the prime minister bows before the queen, he bows before us [the Canadian people]." Either the sovereign or his or her governor general may therefore oppose the prime minister's will in extreme, crisis situations. Near the end of her time as governor general, Adrienne Clarkson stated: "My constitutional role has lain in what are called 'reserve powers': making sure that there is a prime minister and a government in place, and exercising the right 'to encourage, to advise, and to warn'[...] Without really revealing any secrets, I can tell you that I have done all three."


title: Prime Minister of Canada

text: Two official residences are provided to the prime minister—24 Sussex Drive in Ottawa and Harrington Lake, a country retreat in Gatineau Park—as well an office in the Office of the Prime Minister and Privy Council building (formerly known as Langevin Block), across from Parliament Hill. For transportation, the prime minister is afforded an armoured car (a car allowance of $2,000 per year) and shared use of two official aircraft—a CC-150 Polaris for international flights and a Challenger 601 for domestic trips. The Royal Canadian Mounted Police also furnish constant personal security for the prime minister and their family. All of the aforementioned is provided through budgets approved by Parliament, as is the prime minister's total annual compensation of $357,800 (consisting of an MP's salary of $178,900 and the prime minister's salary of $178,900).


title: Prime Minister of Canada

text: Serving or former prime ministers are accorded a state funeral, wherein their casket lies in state in the Centre Block of Parliament Hill. Only Bowell and the Viscount Bennett were given private funerals, Bennett also being the only former prime minister of Canada to die and be buried outside the country and Bowell the only whose funeral was not attended by politicians. John Thompson also died outside Canada, at Windsor Castle, where Queen Victoria permitted his lying-in-state before his body was returned to Canada for a state funeral in Halifax.


title: Prime Minister of Canada

text: Prior to 1919, it was traditional for the monarch to bestow a knighthood on newly appointed Canadian prime ministers. Accordingly, several carried the prefix "Sir" before their name; of the first eight premiers of Canada, only Alexander Mackenzie refused the honour of a knighthood from Queen Victoria. Following the 1919 Nickle Resolution, however, the House of Commons motioned that it should be against the policy of the Canadian Sovereign (and the Canadian government advising the Monarch when such honours are not within the Monarch's personal gift) to bestow aristocratic or chivalric titles to Canadians. The Crown in right of Canada (but not the Crown in right of the United Kingdom, which has periodically bestowed such Imperial honours on such citizens) has since adopted this policy generally, such that the last prime minister to be knighted near appointment was Robert Borden, who was the prime minister at the time the Nickle Resolution was debated in the House of Commons (and was knighted before the resolution). Still, Bennett was, in 1941, six years after he stepped down as prime minister, elevated to the peerage of the United Kingdom by King George VI as Viscount Bennett, of Mickleham in the County of Surrey and of Calgary and Hopewell in Canada. No prime minister has since been titled.


title: Prime Minister of Canada

text: The Canadian Heraldic Authority (CHA) grants former prime ministers an augmentation of honour on the coat of arms of those who apply for them. The heraldic badge, referred to by the CHA as the "mark of the Prime Ministership of Canada", consists of four red maple leaves joined at the stem on a white field ("Argent four maple leaves conjoined in cross at the stem Gules"); the augmentation is usually a canton or centred in the chief. Joe Clark, Pierre Trudeau, John Turner, Brian Mulroney, Kim Campbell, Jean Chrétien and Paul Martin were granted arms with the augmentation.


title: Prime Minister of Canada

text: Canada continues the Westminster tradition of using the title "Prime Minister" when one is speaking to the federal head of government directly; the Department of Canadian Heritage advises that it is incorrect to use the term "Mr. Prime Minister". The written form of address for the prime minister should use his or her full parliamentary title: "The Right Honourable [name], <nowiki>[</nowiki>post-nominal letters<nowiki>]</nowiki>, Prime Minister of Canada". However, while in the House of Commons during Question Period, other members of parliament may address the prime minister as "the Right Honourable Member for [prime minister's riding<nowiki>]</nowiki>" or simply "the Right Honourable Prime Minister". Former prime ministers retain the prefix "the Right Honourable" for the remainder of their lives; should they remain sitting MPs, they may be referred as "the Right Honourable Member for [member's riding<nowiki>]</nowiki>", by their portfolio title (if appointed to one), as in "the Right Honourable Minister of National Defence", or should they become opposition leader, as "the Right Honourable Leader of the Opposition".


title: Prime Minister of Canada

text: In the decades following Confederation, it was common practice to refer to the prime minister as "Premier of Canada", a custom that continued until the First World War, around the time of Robert Borden's premiership. While contemporary sources will still speak of early prime ministers of Canada as "premier", the modern practice is such that the federal head of government is known almost exclusively as the "prime minister", while the provincial and territorial heads of government are termed "premiers" (in French, premiers are addressed as , literally translated as "prime minister of [province]").


title: Prime Minister of Canada

text: The prime minister–designate of Canada refers to the person who has been designated as the future prime minister by the governor general, after either the individual's politicial party won a general election or proposing to form either a confidence and supply government or coalition government. The term does not apply to incumbent prime ministers.


title: Prime Minister of Canada

text: After exiting office, former prime ministers of Canada have engaged in various pursuits. Some remained in politics: Bowell continued as a senator, Stephen Harper returned to the House of Commons as a backbench MP, and Bennett moved to the United Kingdom after being elevated to the House of Lords. A number were leaders of the Official Opposition: John A. Macdonald, Arthur Meighen, Mackenzie King, and Pierre Trudeau, all before being re-appointed as prime minister (Mackenzie King twice); Alexander Mackenzie and John Diefenbaker, both prior to sitting as regular Members of Parliament until their deaths; Wilfrid Laurier dying while still in the post; and Charles Tupper, Louis St. Laurent, and John Turner, each before they returned to private business. Meighen was also appointed to the Senate following his second period as prime minister, but resigned his seat to seek re-election and moved to private enterprise after failing to win a riding. Also returning to civilian life were: Robert Borden, who was Chancellor of Queen's and McGill Universities, as well as working in the financial sector; Lester B. Pearson, who was Chancellor of Carleton University; Joe Clark and Kim Campbell, who became university professors, Clark also consultant and Campbell working in international diplomacy and as the director of private companies and chairperson of interest groups; while Pierre Trudeau and Jean Chrétien returned to legal practice. Former prime ministers also commonly penned autobiographies—Tupper, for example—or published their memoirs—such as Diefenbaker and Paul Martin.


title: Map

text: A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes.


title: Map

text: Many maps are static, fixed to paper or some other durable medium, while others are dynamic or interactive. Although most commonly used to depict geography, maps may represent any space, real or fictional, without regard to context or scale, such as in brain mapping, DNA mapping, or computer network topology mapping. The space being mapped may be two dimensional, such as the surface of the earth, three dimensional, such as the interior of the earth, or even more abstract spaces of any dimension, such as arise in modeling phenomena having many independent variables.


title: Map

text: Although the earliest maps known are of the heavens, geographic maps of territory have a very long tradition and exist from ancient times. The word "map" comes from the , wherein "mappa" meant 'napkin' or 'cloth' and "mundi" 'the world'. Thus, "map" became a shortened term referring to a two-dimensional representation of the surface of the world.


title: Map

text: The history of cartography traces the development of cartography, or mapmaking technology, in human history. Maps have been one of the most important human inventions for millennia, allowing humans to explain and navigate their way through the world. The earliest surviving maps include cave paintings and etchings on tusk and stone, followed by extensive maps produced by ancient Babylon, Greece and Rome, China, and India. In their most simple form maps are two dimensional constructs, however since the age of Classical Greece maps have also been projected onto a three-dimensional sphere known as a globe. The Mercator Projection, developed by Flemish geographer Gerardus Mercator, was widely used as the standard two-dimensional projection of the earth for world maps until the late 20th century, when more accurate projections were formulated. Mercator was also the first to use and popularise the concept of the atlas as a collection of maps.


title: Map

text: Cartography or "map-making" is the study and practice of crafting representations of the Earth upon a flat surface (see History of cartography), and one who makes maps is called a cartographer.


title: Map

text: Road maps are perhaps the most widely used maps today, and form a subset of navigational maps, which also include aeronautical and nautical charts, railroad network maps, and hiking and bicycling maps. In terms of quantity, the largest number of drawn map sheets is probably made up by local surveys, carried out by municipalities, utilities, tax assessors, emergency services providers, and other local agencies. Many national surveying projects have been carried out by the military, such as the British Ordnance Survey: a civilian government agency, internationally renowned for its comprehensively detailed work.


title: Map

text: In addition to location information, maps may also be used to portray contour lines indicating constant values of elevation, temperature, rainfall, etc.


title: Map

text: The orientation of a map is the relationship between the directions on the map and the corresponding compass directions in reality. The word "orient" is derived from Latin , meaning east. In the Middle Ages many maps, including the T and O maps, were drawn with east at the top (meaning that the direction "up" on the map corresponds to East on the compass). The most common cartographic convention is that north is at the top of a map.


title: Map

text: Many maps are drawn to a scale expressed as a ratio, such as 1:10,000, which means that 1 unit of measurement on the map corresponds to 10,000 of that same unit on the ground. The scale statement can be accurate when the region mapped is small enough for the curvature of the Earth to be neglected, such as a city map. Mapping larger regions, where the curvature cannot be ignored, requires projections to map from the curved surface of the Earth to the plane. The impossibility of flattening the sphere to the plane without distortion means that the map cannot have a constant scale. Rather, on most projections, the best that can be attained is an accurate scale along one or two paths on the projection. Because scale differs everywhere, it can only be measured meaningfully as point scale per location. Most maps strive to keep point scale variation within narrow bounds. Although the scale statement is nominal it is usually accurate enough for most purposes unless the map covers a large fraction of the earth. At the scope of a world map, scale as a single number is practically meaningless throughout most of the map. Instead, it usually refers to the scale along the equator.


title: Map

text: Some maps, called cartograms, have the scale deliberately distorted to reflect information other than land area or distance. For example, this map (at the right) of Europe has been distorted to show population distribution, while the rough shape of the continent is still discernible.


title: Map

text: Another example of distorted scale is the famous London Underground map. The basic geographical structure is respected but the tube lines (and the River Thames) are smoothed to clarify the relationships between stations. Near the center of the map, stations are spaced out more than near the edges of the map.


title: Map

text: Further inaccuracies may be deliberate. For example, cartographers may simply omit military installations or remove features solely to enhance the clarity of the map. For example, a road map may not show railroads, smaller waterways, or other prominent non-road objects, and even if it does, it may show them less clearly (e.g. dashed or dotted lines/outlines) than the main roads. Known as decluttering, the practice makes the subject matter that the user is interested in easier to read, usually without sacrificing overall accuracy. Software-based maps often allow the user to toggle decluttering between ON, OFF, and AUTO as needed. In AUTO the degree of decluttering is adjusted as the user changes the scale being displayed.


title: Map

text: Geographic maps use a projection to translate the three-dimensional real surface of the geoid to a two-dimensional picture. Projection always distorts the surface. There are many ways to apportion the distortion, and so there are many map projections. Which projection to use depends on the purpose of the map.


title: Map

text: The various features shown on a map are represented by conventional signs or symbols. For example, colors can be used to indicate a classification of roads. Those signs are usually explained in the margin of the map, or on a separately published characteristic sheet.


title: Map

text: Some cartographers prefer to make the map cover practically the entire screen or sheet of paper, leaving no room "outside" the map for information about the map as a whole. These cartographers typically place such information in an otherwise "blank" region "inside" the mapcartouche, map legend, title, compass rose, bar scale, etc.


title: Map

text: In particular, some maps contain smaller "sub-maps" in otherwise blank regions—often one at a much smaller scale showing the whole globe and where the whole map fits on that globe, and a few showing "regions of interest" at a larger scale to show details that wouldn't otherwise fit.


title: Map

text: Occasionally sub-maps use the same scale as the large map—a few maps of the contiguous United States include a sub-map to the same scale for each of the two non-contiguous states.


title: Map

text: The design and production of maps is a craft that has developed over thousands of years, from clay tablets to Geographic information systems. As a form of Design, particularly closely related to Graphic design, map making incorporates scientific knowledge about how maps are used, integrated with principles of artistic expression, to create an aesthetically attractive product, carries an aura of authority, and functionally serves a particular purpose for an intended audience.


title: Map

text: Designing a map involves bringing together a number of elements and making a large number of decisions. The elements of design fall into several broad topics, each of which has its own theory, its own research agenda, and its own best practices. That said, there are synergistic effects between these elements, meaning that the overall design process is not just working on each element one at a time, but an iterative feedback process of adjusting each to achieve the desired gestalt.


title: Map

text: Maps of the world or large areas are often either 'political' or 'physical'. The most important purpose of the political map is to show territorial borders; the purpose of the physical is to show features of geography such as mountains, soil type, or land use including infrastructures such as roads, railroads, and buildings. Topographic maps show elevations and relief with contour lines or shading. Geological maps show not only the physical surface, but characteristics of the underlying rock, fault lines, and subsurface structures.


title: Map

text: From the last quarter of the 20th century, the indispensable tool of the cartographer has been the computer. Much of cartography, especially at the data-gathering survey level, has been subsumed by Geographic Information Systems (GIS). The functionality of maps has been greatly advanced by technology simplifying the superimposition of spatially located variables onto existing geographical maps. Having local information such as rainfall level, distribution of wildlife, or demographic data integrated within the map allows more efficient analysis and better decision making. In the pre-electronic age such superimposition of data led Dr. John Snow to identify the location of an outbreak of cholera. Today, it is used by agencies of humankind, as diverse as wildlife conservationists and militaries around the world.


title: Map

text: Even when GIS is not involved, most cartographers now use a variety of computer graphics programs to generate new maps.


title: Map

text: Interactive, computerized maps are commercially available, allowing users to "zoom in" or "zoom out" (respectively meaning to increase or decrease the scale), sometimes by replacing one map with another of different scale, centered where possible on the same point. In-car global navigation satellite systems are computerized maps with route planning and advice facilities that monitor the user's position with the help of satellites. From the computer scientist's point of view, zooming in entails one or a combination of:


title: Map

text: The maps that reflect the territorial distribution of climatic conditions based on the results of long-term observations are called "climatic maps". These maps can be compiled both for individual climatic features (temperature, precipitation, humidity) and for combinations of them at the earth's surface and in the upper layers of the atmosphere. Climatic maps show climatic features across a large region and permit values of climatic features to be compared in different parts of the region. When generating the map, spatial interpolation can be used to synthesize values where there are no measurements, under the assumption that conditions change smoothly.


title: Map

text: Climatic maps generally apply to individual months and the year as a whole, sometimes to the four seasons, to the growing period, and so forth. On maps compiled from the observations of ground meteorological stations, atmospheric pressure is converted to sea level. Air temperature maps are compiled both from the actual values observed on the surface of the earth and from values converted to sea level. The pressure field in the free atmosphere is represented either by maps of the distribution of pressure at different standard altitudes—for example, at every kilometer above sea level—or by maps of baric topography on which altitudes (more precisely geopotentials) of the main isobaric surfaces (for example, 900, 800, and 700 millibars) counted off from sea level are plotted. The temperature, humidity, and wind on aero climatic maps may apply either to standard altitudes or to the main isobaric surfaces.


title: Map

text: Isolines are drawn on maps of such climatic features as the long-term mean values (of atmospheric pressure, temperature, humidity, total precipitation, and so forth) to connect points with equal values of the feature in question—for example, isobars for pressure, isotherms for temperature, and isohyets for precipitation. Isoamplitudes are drawn on maps of amplitudes (for example, annual amplitudes of air temperature—that is, the differences between the mean temperatures of the warmest and coldest month). Isanomals are drawn on maps of anomalies (for example, deviations of the mean temperature of each place from the mean temperature of the entire latitudinal zone). Isolines of frequency are drawn on maps showing the frequency of a particular phenomenon (for example, the annual number of days with a thunderstorm or snow cover). Isochrones are drawn on maps showing the dates of onset of a given phenomenon (for example, the first frost and appearance or disappearance of the snow cover) or the date of a particular value of a meteorological element in the course of a year (for example, passing of the mean daily air temperature through zero). Isolines of the mean numerical value of wind velocity or isotachs are drawn on wind maps (charts); the wind resultants and directions of prevailing winds are indicated by arrows of different lengths or arrows with different plumes; lines of flow are often drawn. Maps of the zonal and meridional components of wind are frequently compiled for the free atmosphere. Atmospheric pressure and wind are usually combined on climatic maps. Wind roses, curves showing the distribution of other meteorological elements, diagrams of the annual course of elements at individual stations, and the like are also plotted on climatic maps.


title: Map

text: Maps of climatic regionalization, that is, division of the earth's surface into climatic zones and regions according to some classification of climates, are a special kind of climatic map.


title: Map

text: Climatic maps are often incorporated into climatic atlases of varying geographic ranges (globe, hemispheres, continents, countries, oceans) or included in comprehensive atlases. Besides general climatic maps, applied climatic maps and atlases have great practical value. Aero climatic maps, aero climatic atlases, and agro climatic maps are the most numerous.


title: Map

text: Maps exist of the Solar System, and other cosmological features such as star maps. In addition maps of other bodies such as the Moon and other planets are technically not "geo"graphical maps.


title: Map

text: Diagrams such as schematic diagrams and Gantt charts and tree maps display logical relationships between items, rather than geographical relationships. Topological in nature, only the connectivity is significant. The London Underground map and similar subway maps around the world are a common example of these maps.


title: Map

text: General-purpose maps provide many types of information on one map. Most atlas maps, wall maps, and road maps fall into this category. The following are some features that might be shown on general-purpose maps: bodies of water, roads, railway lines, parks, elevations, towns and cities, political boundaries, latitude and longitude, national and provincial parks. These maps give a broad understanding of the location and features of an area. The reader may gain an understanding of the type of landscape, the location of urban places, and the location of major transportation routes all at once.


title: Map

text: Some countries required that all published maps represent their national claims regarding border disputes. For example:


title: Map

text: In 2010, the People's Republic of China began requiring that all online maps served from within China be hosted there, making them subject to Chinese laws.


title: Grimm (TV series)

text: Grimm is an American fantasy police procedural drama television series created by Stephen Carpenter and Jim Kouf & David Greenwalt and produced by Universal Television for NBC. The series aired from October 28, 2011, to March 31, 2017, for 123 episodes, over six seasons. The series' narrative follows Portland homicide detective Nicholas Burkhardt (played by David Giuntoli), who discovers he is a Grimm, the latest in a line of guardians who is sworn to keep the balance between humanity and mythological creatures, known as Wesen. The series features a supporting cast with Russell Hornsby, Bitsie Tulloch, Silas Weir Mitchell, Sasha Roiz, Reggie Lee, Bree Turner, and Claire Coffee.


title: Grimm (TV series)

text: "Grimm" was originally developed for CBS, but did not end up moving forward due to the 2007–08 writers' strike. In January 2011, the series moved to NBC. It has been described as "a cop drama—with a twist ... a dark and fantastical project about a world in which characters inspired by "Grimms' Fairy Tales" exist", though the stories and characters inspiring the show are also drawn from other sources. The series initially garnered mixed reviews from critics, though reception grew more favorable throughout the series' run. The sixth and final season of "Grimm" premiered on January 6, 2017, and concluded on March 31, 2017.


title: Grimm (TV series)

text: Homicide investigator Nick Burkhardt of the Portland Police Department learns he is descended from a line of guardians known as "Grimms", charged with keeping balance between humanity and the ', or mythological creatures of the world (' is the German word for "being" or "creature"). Throughout the series, he must battle against an assortment of dangerous creatures with help from his friend, Monroe, and his partner, Detective Hank Griffin.


title: Grimm (TV series)

text: Black Claw and Hadrian's Wall (HW) are two opposing groups repeatedly mentioned in the series where many characters belong to these creature (wesen) groups.


title: Grimm (TV series)

text: Opening: ""There once was a man who lived a life so strange, it had to be true. Only he could see what no one else can—the darkness inside, the real monster within, and he's the one who must stop them. This is his calling. This is his duty. This is the life of a Grimm.""


title: Grimm (TV series)

text: Many of the episodes are loosely based on stories published by the Brothers Grimm, albeit with considerable artistic license taken. For example, the pilot centered around a wolf-man who preyed on women who wore red. Other episodes are based on different sources, including fables and legends, not published by the Brothers Grimm.


title: Grimm (TV series)

text: In 2008, CBS canceled development on a drama called "Brother Grimm", written by Stephen Carpenter and produced by CBS Paramount Television and Hazy Mills Productions, because of the 2007–08 writers' strike.


title: Grimm (TV series)

text: In January 2011, NBC announced that they had given a pilot order to a series titled "Grimm", pitched by David Greenwalt and Jim Kouf. The series was produced by Universal Media Studios and Hazy Mills Productions, with Greenwalt and Kouf also serving as executive producers for the series, along with Sean Hayes and Todd Milliner. In May 2011, NBC picked up the pilot to series.


title: Grimm (TV series)

text: Filming on the series began in March 2011, in and around Portland, Oregon. Greenwalt and Kouf told Portland's NBC affiliate KGW that they chose Portland because of its plentiful forests in the city's two largest parks, Washington Park and Forest Park.


title: Grimm (TV series)

text: On September 30, 2011, NBC delayed the debut of "Grimm" by one month, moving the premiere to October 28, 2011, so it could premiere closer to Halloween. The series was slated on Friday nights for the majority of its first season. On November 21, 2011, NBC picked up the series for a full 22-episode season. NBC aired a special Thursday screening on December 8, 2011, at 10 pm to analyse whether the network's overall ratings could improve.


title: Grimm (TV series)

text: On March 16, 2012, NBC announced that the series had been renewed for a second season; according to writers/producers David Greenwalt and Jim Kouf, they would continue to film the show in Portland, saying, "Rain or shine, Portland has been the ideal setting for fairy tales with its enchanting layout. It is its own character in our show with the perfect mix of urban and rural settings." The second season premiered on Monday, August 13, 2012, and continued on Mondays for four episodes, before returning to its original Friday timeslot on September 10. NBC moved "Grimm" to Tuesday nights beginning April 30, 2013, for the remainder of Season 2.


title: Grimm (TV series)

text: The series was renewed for a third season on April 26, 2013. The third season premiered on October 25, 2013, which returned the show to its original Friday timeslot. On March 19, 2014, NBC announced that "Grimm" had been renewed for a fourth season, which premiered on October 24, 2014.


title: Grimm (TV series)

text: On February 5, 2015, NBC renewed the series for a fifth season, which premiered on Friday, October 30, 2015.


title: Grimm (TV series)

text: On April 5, 2016, NBC renewed the series for a sixth season, consisting of 13 episodes. On August 29, 2016, it was announced that season six would serve as the series' final season. The series concluded on March 31, 2017.


title: Grimm (TV series)

text: David Giuntoli was the first to be cast in the series, in the titular role of Nick Burkhardt, in February 2011 He was followed by Silas Weir Mitchell as Monroe, the now-reformed "big bad wolf". Following him, Russell Hornsby and Bitsie Tulloch were cast as Nick's partner Hank and his girlfriend, Juliette, respectively. The following month, Sasha Roiz was cast as a series regular, in the role of Captain Sean Renard.


title: Grimm (TV series)

text: Bree Turner, who guest starred in four episodes of Season 1 as Rosalee Calvert, was promoted to series regular for Season 2. Claire Coffee, playing Adalind Schade, was also upgraded to series regular for Season 2.


title: Grimm (TV series)

text: The series' premiere received mixed reviews from critics. On Metacritic the series has a score of 55 out of 100, based on reviews from 23 critics.


title: Grimm (TV series)

text: "The Hollywood Reporter's" Tim Goodman felt that "[i]t has chills and humor and the ability to take a procedural story and twist it." Mike Hale of "The New York Times" said, "Some of the jokes work, and some of the frights are actually scary, and on a repeat viewing the craftsmanship and attention to detail made more of an impression."


title: Grimm (TV series)

text: Mary McNamara of the "Los Angeles Times" wrote in a mixed review that she preferred other fairy-tale themed dramas, such as ABC's "Once Upon a Time", stating that despite a good cast and setting, "Grimm" puts an "entertaining crime spin on fairy-tale monsters that's a little too pat ... [And] adds up to a nice, moody, entertaining-enough hour and the troublesome question of how interesting this will be by the third episode."


title: Grimm (TV series)

text: Daynah Burnett, who reviewed the program for PopMatters, felt "[a]s Grimm grasps for compelling analogues between fairy tales' villains and ours, its stories turn exceedingly literal: wolves urinate in the corners of their lawns to mark their territory, rather than lurk (and mark) in ways less obvious and more culturally meaningful. There's certainly room here for these archetypes to be explored as the series develops, but when Nick's prime suspect for the red-hoodie crimes turns out to live in an actual cottage in the woods, it doesn't bode well for how these stories might reflect the lives of viewers", before giving it a score of 4 out of 10.


title: Grimm (TV series)

text: The second season received a more favorable response, with a score of 75 out of 100 on Metacritic, based on four reviews. "The Los Angeles Times" reviewed the second-season premiere as, "it's hard not to love a show with a comely apothecary, and it's impossible not to love the new season of "Grimm"."


title: Grimm (TV series)

text: Mike Hale of "The New York Times" said of season three, "Grimm is not a profound show (what is?), but few are more purely entertaining – engaging, clever, tense, funny, well paced and featuring a remarkably appealing cast as the friends and colleagues who help Nick."


title: Grimm (TV series)

text: A press release by NBC on November 11, 2011, stated, ""Grimm" and "Up All Night" Are the #1 New Drama and #1 New Comedy Among Top % Gainers Going from Live+Same Day to Live+7. "Grimm" is the #1 new drama on ABC, CBS, NBC or Fox in terms of percentage increase from L+SD to L+7 so far this season and also the #1 new series and the #2 show overall behind only Fox's "Fringe" (+57%), growing by +49% in adults 18–49 (to a 2.98 rating from a 2.00)" The series averaged about 6.4 million U.S. viewers during its first season, and was consequently renewed for a second season.


title: Grimm (TV series)

text: By Friday, September 28, 2012, "Grimm" had increased its adult 18-49 rating by 1.14 points going from "live plus same day" ratings to "live plus three day" results from Nielsen Media Research (from a 1.58 to a 2.72). The 1.14 increase was "Grimm"s biggest gain ever, going from L+SD to L+3. The 2.72 was "Grimm"'s highest L+3 rating since the show's second-season premiere on Monday, August 13.


title: Grimm (TV series)

text: In May 2013, Dynamite Entertainment started releasing a monthly Grimm Comic Book series. The series ended with issue #12, which was released April 30, 2014.


title: Grimm (TV series)

text: Novelist John Shirley was hired to write the first novel based on the Grimm television show. "Grimm: The Icy Touch" was published by Titan Books on November 5, 2013, and book 2, "Grimm: The Chopping Block", written by John Passarella, was published February 18, 2014. The third novel, "Grimm: The Killing Time", was written by Tim Waggoner and was published on September 30, 2014.


title: Grimm (TV series)

text: On October 16, 2018, NBC announced that a spin-off of the series was in development. The potential new series would focus on another Grimm and would continue to build off the mythology of the original series. As of June 2021, the project is dead.


title: Grimm (TV series)

text: The series premiered in Australia on January 4, 2012, on FOX8, with season two returning on September 30, 2012, followed by season three on October 30, 2013, and season four on January 7, 2015. The series was replayed on free-to-air network Seven (as opposed to FOX8, which is a subscription television network), with season one premiering November 30, 2012, with season two returning on August 1, 2013, and season three on October 15, 2014.


title: Grimm (TV series)

text: The series premiered in Canada on October 28, 2011, on CTV, with season two returning on August 13, 2012, followed by season three on October 25, 2013, and season four on October 24, 2014.


title: Grimm (TV series)

text: The series premiered in the UK on February 13, 2012, on W (known then as Watch), with season two returning on October 22, 2012, and season 3 on February 5, 2014. The fourth season premiered on January 28, 2015. The fifth season premiered on November 3, 2015. The sixth and final season premiered on February 14, 2017.


title: Grimm (TV series)

text: The series premiered in India on June 30, 2016, on Colors Infinity, with the first five seasons being broadcast back-to-back on weekdays (Monday–Friday). The final season was aired as a part of the network's "Instant Premieres" programming block, with each episode of season six being aired within 12 hours of its US broadcast.


title: Email address

text: An email address identifies an email box to which messages are delivered. While early messaging systems used a variety of formats for addressing, today, email addresses follow a set of specific rules originally standardized by the Internet Engineering Task Force (IETF) in the 1980s, and updated by . The term email address in this article refers to just the "addr-spec" in Section 3.4 of RFC 5322. The RFC defines "address" more broadly as either a "mailbox" or "group". A "mailbox" value can be either a "name-addr", which contains a "display-name" and "addr-spec", or the more common "addr-spec" alone.


title: Email address

text: An email address, such as "john.smith@example.com", is made up from a local-part, the symbol @, and a "domain", which may be a domain name or an IP address enclosed in brackets. Although the standard requires the local part to be case-sensitive,


title: Email address

text: e.g., that the mail system in the domain "example.com" treat "John.Smith" as equivalent to "john.smith"; some mail systems even treat them as equivalent to "johnsmith". Mail systems often limit the users' choice of name to a subset of the technically permitted characters.


title: Email address

text: With the introduction of internationalized domain names, efforts are progressing to permit non-ASCII characters in email addresses.


title: Email address

text: An email address consists of two parts, a local part and a domain; if the domain is a domain name rather than an IP address then the SMTP client uses the domain name to look up the mail exchange IP address.


title: Email address

text: The general format of an email address is "local-part"@"domain", e.g. jsmith@<nowiki>[</nowiki>192.168.1.2<nowiki>]</nowiki>, "jsmith@example.com". The SMTP client transmits the message to the mail exchange, which may forward it to another mail exchange until it eventually arrives at the host of the recipient's mail system.


title: Email address

text: The transmission of electronic mail from the author's computer and between mail hosts in the Internet uses the Simple Mail Transfer Protocol (SMTP), defined in , and extensions such as RFC 6531. The mailboxes may be accessed and managed by applications on personal computers, mobile devices or webmail sites, using the SMTP protocol and either the Post Office Protocol (POP) or the Internet Message Access Protocol (IMAP).


title: Email address

text: When transmitting email messages, mail user agents (MUAs) and mail transfer agents (MTAs) use the domain name system (DNS) to look up a Resource Record (RR) for the recipient's domain. A mail exchanger resource record (MX record) contains the name of the recipient's mailserver. In absence of an MX record, an address record (A or AAAA) directly specifies the mail host.


title: Email address

text: The local part of an email address has no significance for intermediate mail relay systems other than the final mailbox host. Email senders and intermediate relay systems must not assume it to be case-insensitive, since the final mailbox host may or may not treat it as such. A single mailbox may receive mail for multiple email addresses, if configured by the administrator. Conversely, a single email address may be the alias to a distribution list to many mailboxes. Email aliases, electronic mailing lists, sub-addressing, and catch-all addresses, the latter being mailboxes that receive messages regardless of the local part, are common patterns for achieving a variety of delivery goals.


title: Email address

text: The addresses found in the header fields of an email message are not directly used by mail exchanges to deliver the message. An email message also contains a message envelope that contains the information for mail routing. While envelope and header addresses may be equal, forged email addresses - also called "spoofed email addresses" - are often seen in spam, phishing, and many other Internet-based scams. This has led to several initiatives which aim to make such forgeries of fraudulent emails easier to spot.


title: Email address

text: The format of an email address is "local-part@domain", where the local part may be up to 64 octets long and the domain may have a maximum of 255 octets. The formal definitions are in <nowiki>RFC 5322</nowiki> (sections 3.2.3 and 3.4.1) and <nowiki>RFC 5321</nowiki>—with a more readable form given in the informational <nowiki>RFC 3696</nowiki> and the associated errata.


title: Email address

text: An email address also may have an associated display name for the recipient, which precedes the address specification, now surrounded by angled brackets, for example: "John Smith <john.smith@example.org>".


title: Email address

text: Earlier forms of email addresses for other networks than the Internet included other notations, such as that required by X.400, and the UUCP "bang path" notation, in which the address was given in the form of a sequence of computers through which the message should be relayed. This was widely used for several years, but was superseded by the Internet standards promulgated by the Internet Engineering Task Force (IETF).


title: Email address

text: If quoted, it may contain Space, Horizontal Tab (HT), any ASCII graphic except Backslash and Quote and a quoted-pair consisting of a Backslash followed by HT, Space or any ASCII graphic; it may also be split between lines anywhere that HT or Space appears. In contrast to unquoted local-parts, the addresses codice_10, codice_11 and codice_12 are allowed.


title: Email address

text: Note that some mail servers support wildcard recognition of local parts, typically the characters following a plus and less often the characters following a minus, so fred+bah@domain and fred+foo@domain might end up in the same inbox as fred+@domain or even as fred@domain. This can be useful for tagging emails for sorting (see below), and for spam control. Braces codice_13 and codice_14 are also used in that fashion, although less often.


title: Email address

text: In addition to the above ASCII characters, international characters above U+007F, encoded as UTF-8, are permitted by <nowiki>RFC 6531</nowiki>, though even mail systems that support SMTPUTF8 and 8BITMIME may restrict which characters to use when assigning local-parts.


title: Email address

text: Quoted strings and characters, however, are not commonly used. <nowiki>RFC 5321</nowiki> also warns that "a host that expects to receive mail SHOULD avoid defining mailboxes where the Local-part requires (or uses) the Quoted-string form".


title: Email address

text: The local-part codice_19 is treated specially—it is case-insensitive, and should be forwarded to the domain email administrator. Technically all other local-parts are case-sensitive, therefore codice_20 and codice_21 specify different mailboxes; however, many organizations treat uppercase and lowercase letters as equivalent. Indeed, <nowiki>RFC 5321</nowiki> warns that "a host that expects to receive mail SHOULD avoid defining mailboxes where ... the Local-part is case-sensitive".


title: Email address

text: Despite the wide range of special characters which are technically valid, organisations, mail services, mail servers and mail clients in practice often do not accept all of them. For example, Windows Live Hotmail only allows creation of email addresses using alphanumerics, dot (codice_8), underscore (codice_23) and hyphen (codice_24). Common advice is to avoid using some special characters to avoid the risk of rejected emails.


title: Email address

text: The domain name part of an email address has to conform to strict guidelines: it must match the requirements for a hostname, a list of dot-separated DNS labels, each label being limited to a length of 63 characters and consisting of:


title: Email address

text: This rule is known as the "LDH rule" (letters, digits, hyphen). In addition, the domain may be an IP address literal, surrounded by square brackets codice_32, such as codice_33 or codice_34, although this is rarely seen except in email spam. Internationalized domain names (which are encoded to comply with the requirements for a hostname) allow for presentation of non-ASCII domains. In mail systems compliant with <nowiki>RFC 6531</nowiki> and <nowiki>RFC 6532</nowiki> an email address may be encoded as UTF-8, both a local-part as well as a domain name.


title: Email address

text: Comments are allowed in the domain as well as in the local-part; for example, codice_35 and codice_36 are equivalent to codice_18.


title: Email address

text: specifies that certain domains, for example those intended for documentation and testing, should not be resolvable and that as a result mail addressed to mailboxes in them and their subdomains should be non-deliverable. Of note for e-mail are "example", "invalid", "example.com", "example.net", and "example.org".


title: Email address

text: According to <nowiki>RFC 5321</nowiki> 2.3.11 "Mailbox and Address," "...the local-part MUST be interpreted and assigned semantics only by the host specified in the domain of the address."


title: Email address

text: This means that no assumptions can be made about the meaning of the local-part of another mail server. It is entirely up to the configuration of the mail server.


title: Email address

text: Interpretation of the "local part" of an email address is dependent on the conventions and policies implemented in the mail server. For example, case sensitivity may distinguish mailboxes differing only in capitalization of characters of the local-part, although this is not very common. Gmail ignores all dots in the local-part of a "@gmail.com" address for the purposes of determining account identity.


title: Email address

text: Some mail services support a tag included in the local-part, such that the address is an alias to a prefix of the local part. For example, the address "joeuser+tag@example.com" denotes the same delivery address as "joeuser@example.com". <nowiki>RFC 5233</nowiki>, refers to this convention as "subaddressing", but it is also known as "plus addressing", "tagged addressing" or "mail extensions".


title: Email address

text: Addresses of this form, using various separators between the base name and the tag, are supported by several email services, including Andrew Project (plus), Runbox (plus), Gmail (plus), Rackspace (plus), Yahoo! Mail Plus (hyphen), Apple's iCloud (plus), Outlook.com (plus), Proton Mail (plus),


title: Email address

text: Qmail and Courier Mail Server (hyphen). Postfix and Exim allow configuring an arbitrary separator from the legal character set.


title: Email address

text: The text of the tag may be used to apply filtering, or to create "single-use", or disposable email addresses.


title: Email address

text: In practice, the form validation of some web sites may reject characters such as "+" in an email address – treating them, incorrectly, as invalid characters. This can lead to an incorrect user receiving an e-mail if the "+" is silently stripped by a website without any warning or error messages. For example, an email intended for the user-entered email address foo+bar@example.com could be incorrectly sent to foobar@example.com. In other cases a poor user experience can occur if some parts of a site, such as a user registration page, allow the "+" character whilst other parts, such as a page for unsubscribing from a site's mailing list, do not.


title: Email address

text: Email addresses are often requested as input to website as validation of user existence. Other validation methods are available, such as cell phone number validation, postal mail validation, and fax validation.


title: Email address

text: An email address is generally recognized as having two parts joined with an at-sign ("@"), although technical specification detailed in <nowiki>RFC 822</nowiki> and subsequent RFCs are more extensive.


title: Email address

text: Syntactically correct, verified email addresses do not guarantee that an email box exists. Thus many mail servers use other techniques and check the mailbox existence against relevant systems such as the Domain Name System for the domain or using callback verification to check if the mailbox exists. Callback verification is an imperfect solution, as it may be disabled to avoid a directory harvest attack, or callbacks may be reported as spam and lead to listing on a DNSBL.


title: Email address

text: Some companies offer services to validate an email address, often using an application programming interface, but there is no guarantee that it will provide accurate results.


title: Email address

text: The IETF conducts a technical and standards working group devoted to internationalization issues of email addresses, entitled "Email Address Internationalization" (EAI, also known as IMA, Internationalized Mail Address). This group produced , and continues to work on additional EAI-related RFCs.


title: Email address

text: The IETF's EAI Working group published <nowiki>RFC 6530</nowiki> "Overview and Framework for Internationalized Email", which enabled non-ASCII characters to be used in both the local-parts and domain of an email address. <nowiki>RFC 6530</nowiki> provides for email based on the UTF-8 encoding, which permits the full repertoire of Unicode. <nowiki>RFC 6531</nowiki> provides a mechanism for SMTP servers to negotiate transmission of the SMTPUTF8 content.


title: Email address

text: The basic EAI concepts involve exchanging mail in UTF-8. Though the original proposal included a downgrading mechanism for legacy systems, this has now been dropped. The local servers are responsible for the local-part of the address, whereas the domain would be restricted by the rules of internationalized domain names, though still transmitted in UTF-8. The mail server is also responsible for any mapping mechanism between the IMA form and any ASCII alias.


title: Email address

text: EAI enables users to have a localized address in a native language script or character set, as well as an ASCII form for communicating with legacy systems or for script-independent use. Applications that recognize internationalized domain names and mail addresses must have facilities to convert these representations.


title: Email address

text: Significant demand for such addresses is expected in China, Japan, Russia, and other markets that have large user bases in a non-Latin-based writing system.


title: Email address

text: For example, in addition to the .in top-level domain, the government of India in 2011 got approval for ".bharat", (from "Bhārat Gaṇarājya"), written in seven different scripts for use by Gujrati, Marathi, Bangali, Tamil, Telugu, Punjabi and Urdu speakers. Indian company XgenPlus.com claims to be the world's first EAI mailbox provider, and the Government of Rajasthan now supplies a free email account on domain राजस्थान.भारत for every citizen of the state. A leading media house Rajasthan Patrika launched their IDN domain पत्रिका.भारत with contactable email.


title: Email address

text: The example addresses below would not be handled by <nowiki>RFC 5322</nowiki> based servers, but are permitted by <nowiki>RFC 6530</nowiki>. Servers compliant with this will be able to handle these:


title: Julia Roberts filmography

text: Julia Roberts is an American actress and producer who made her debut in the 1987 direct-to-video feature "Firehouse". She had her breakthrough the following year by starring in the coming-of-age film "Mystic Pizza" (1988). For her supporting role in the comedy-drama "Steel Magnolias" (1989), she won the Golden Globe Award for Best Supporting Actress. Roberts' next role was opposite Richard Gere in the highly successful romantic comedy "Pretty Woman" (1990), for which she won the Golden Globe Award for Best Actress (Musical or Comedy). In 1991, she appeared in the psychological thriller "Sleeping with the Enemy", and played Tinker Bell in the Steven Spielberg-directed fantasy adventure "Hook". Two years later, Roberts starred in the legal thriller "The Pelican Brief", an adaptation of the John Grisham novel of the same name. During the late 1990s, she played the lead in the romantic comedies "My Best Friend's Wedding" (1997), "Notting Hill" (1999), and "Runaway Bride" (1999).


title: Julia Roberts filmography

text: In 2000, Roberts became the first actress to earn $20 million, for playing the eponymous environmental activist in the Steven Soderbergh-directed biographical film "Erin Brockovich". Her performance won her the Academy Award for Best Actress, the BAFTA Award for Best Actress in a Leading Role, and the Golden Globe Award for Best Actress (Drama). The following year, she starred in the romantic comedy "America's Sweethearts" (2001), and reteamed with Soderbergh on the comedy heist remake "Ocean's Eleven" (2001). Roberts appeared in the 2003 drama, "Mona Lisa Smile", which earned her a then record $25 million salary. The following year, she starred in the romantic drama "Closer" (2004), and also reprised her role in the sequel, "Ocean's Twelve" (2004). In 2006, she lent her voice to two animated films: "The Ant Bully", and "Charlotte's Web". Roberts went on to appear in the comedy-dramas "Charlie Wilson's War" (2007) and "Eat Pray Love" (2010), following which she starred in "" (2013), for which she was nominated for the Academy Award for Best Supporting Actress. In 2016, Roberts played a television producer in the thriller "Money Monster" and the following year, she played a mother coping with her son's Treacher Collins syndrome in the comedy-drama "Wonder".


title: Julia Roberts filmography

text: Roberts made her television debut in the drama series "Crime Story" in 1987. She appeared in the crime drama series "Miami Vice", and the television film "Baja Oklahoma" (both in 1988). In 1996, Roberts guest starred on the television sitcom "Friends". Her guest star appearance on the police procedural/legal drama "Law & Order" in 1999, earned Roberts a nomination for the Primetime Emmy Award for Outstanding Guest Actor in a Drama Series. She has, as of 2014, served as an executive producer on four films in the "American Girl" film series. The first three were television films while the fourth, "", had a theatrical release in 2008. In 2014, Roberts provided narration for an episode of the documentary series "", and appeared in the film "The Normal Heart". Her role in the latter earned Roberts a nomination for the Primetime Emmy Award for Outstanding Supporting Actress in a Miniseries or a Movie.


title: Adenosine triphosphate

text: Adenosine triphosphate (ATP) is an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer. When consumed in metabolic processes, it converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes regenerate ATP. The human body recycles its own body weight equivalent in ATP each day. It is also a precursor to DNA and RNA, and is used as a coenzyme.


title: Adenosine triphosphate

text: From the perspective of biochemistry, ATP is classified as a nucleoside triphosphate, which indicates that it consists of three components: a nitrogenous base (adenine), the sugar ribose, and the triphosphate.


title: Adenosine triphosphate

text: ATP consists of an adenine attached by the 9-nitrogen atom to the 1′ carbon atom of a sugar (ribose), which in turn is attached at the 5' carbon atom of the sugar to a triphosphate group. In its many reactions related to metabolism, the adenine and sugar groups remain unchanged, but the triphosphate is converted to di- and monophosphate, giving respectively the derivatives ADP and AMP. The three phosphoryl groups are labeled as alpha (α), beta (β), and, for the terminal phosphate, gamma (γ).


title: Adenosine triphosphate

text: Being polyanionic and featuring a potentially chelating polyphosphate group, ATP binds metal cations with high affinity. The binding constant for is (). The binding of a divalent cation, almost always magnesium, strongly affects the interaction of ATP with various proteins. Due to the strength of the ATP-Mg interaction, ATP exists in the cell mostly as a complex with bonded to the phosphate oxygen centers.


title: Adenosine triphosphate

text: A second magnesium ion is critical for ATP binding in the kinase domain. The presence of Mg regulates kinase activity.


title: Adenosine triphosphate

text: ATP is stable in aqueous solutions between pH 6.8 and 7.4, in the absence of catalysts. At more extreme pHs, it rapidly hydrolyses to ADP and phosphate. Living cells maintain the ratio of ATP to ADP at a point ten orders of magnitude from equilibrium, with ATP concentrations fivefold higher than the concentration of ADP. In the context of biochemical reactions, the P-O-P bonds are frequently referred to as "high-energy bonds".


title: Adenosine triphosphate

text: The hydrolysis of ATP into ADP and inorganic phosphate releases 20.5 kJ/mol of enthalpy. The values of the free energy released by cleaving either a phosphate (P) or a pyrophosphate (PP) unit from ATP at standard state concentrations of 1 mol/L at pH 7 are:


title: Adenosine triphosphate

text: At cytoplasmic conditions, where the ADP/ATP ratio is 10 orders of magnitude from equilibrium, the Δ"G" is around −57 kJ/mol.


title: Adenosine triphosphate

text: A typical intracellular concentration of ATP is hard to pin down, however, reports have shown there to be 1–10 μmol per gram of tissue in a variety of eukaryotes. The dephosphorylation of ATP and rephosphorylation of ADP and AMP occur repeatedly in the course of aerobic metabolism.


title: Adenosine triphosphate

text: ATP can be produced by a number of distinct cellular processes; the three main pathways in eukaryotes are (1) glycolysis, (2) the citric acid cycle/oxidative phosphorylation, and (3) beta-oxidation. The overall process of oxidizing glucose to carbon dioxide, the combination of pathways 1 and 2, known as cellular respiration, produces about 30 equivalents of ATP from each molecule of glucose.


title: Adenosine triphosphate

text: ATP production by a non-photosynthetic aerobic eukaryote occurs mainly in the mitochondria, which comprise nearly 25% of the volume of a typical cell.


title: Adenosine triphosphate

text: In glycolysis, glucose and glycerol are metabolized to pyruvate. Glycolysis generates two equivalents of ATP through substrate phosphorylation catalyzed by two enzymes, PGK and pyruvate kinase. Two equivalents of NADH are also produced, which can be oxidized via the electron transport chain and result in the generation of additional ATP by ATP synthase. The pyruvate generated as an end-product of glycolysis is a substrate for the Krebs Cycle.


title: Adenosine triphosphate

text: Glycolysis is viewed as consisting of two phases with five steps each. In phase 1, "the preparatory phase", glucose is converted to 2 d-glyceraldehyde-3-phosphate (g3p). One ATP is invested in Step 1, and another ATP is invested in Step 3. Steps 1 and 3 of glycolysis are referred to as "Priming Steps". In Phase 2, two equivalents of g3p are converted to two pyruvates. In Step 7, two ATP are produced. Also, in Step 10, two further equivalents of ATP are produced. In Steps 7 and 10, ATP is generated from ADP. A net of two ATPs is formed in the glycolysis cycle. The glycolysis pathway is later associated with the Citric Acid Cycle which produces additional equivalents of ATP.


title: Adenosine triphosphate

text: In glycolysis, hexokinase is directly inhibited by its product, glucose-6-phosphate, and pyruvate kinase is inhibited by ATP itself. The main control point for the glycolytic pathway is phosphofructokinase (PFK), which is allosterically inhibited by high concentrations of ATP and activated by high concentrations of AMP. The inhibition of PFK by ATP is unusual since ATP is also a substrate in the reaction catalyzed by PFK; the active form of the enzyme is a tetramer that exists in two conformations, only one of which binds the second substrate fructose-6-phosphate (F6P). The protein has two binding sites for ATP – the active site is accessible in either protein conformation, but ATP binding to the inhibitor site stabilizes the conformation that binds F6P poorly. A number of other small molecules can compensate for the ATP-induced shift in equilibrium conformation and reactivate PFK, including cyclic AMP, ammonium ions, inorganic phosphate, and fructose-1,6- and -2,6-biphosphate.


title: Adenosine triphosphate

text: In the mitochondrion, pyruvate is oxidized by the pyruvate dehydrogenase complex to the acetyl group, which is fully oxidized to carbon dioxide by the citric acid cycle (also known as the Krebs cycle). Every "turn" of the citric acid cycle produces two molecules of carbon dioxide, one equivalent of ATP guanosine triphosphate (GTP) through substrate-level phosphorylation catalyzed by succinyl-CoA synthetase, as succinyl-CoA is converted to succinate, three equivalents of NADH, and one equivalent of FADH. NADH and FADH are recycled (to NAD and FAD, respectively) by oxidative phosphorylation, generating additional ATP. The oxidation of NADH results in the synthesis of 2–3 equivalents of ATP, and the oxidation of one FADH yields between 1–2 equivalents of ATP. The majority of cellular ATP is generated by this process. Although the citric acid cycle itself does not involve molecular oxygen, it is an obligately aerobic process because O is used to recycle the NADH and FADH. In the absence of oxygen, the citric acid cycle ceases.


title: Adenosine triphosphate

text: The generation of ATP by the mitochondrion from cytosolic NADH relies on the malate-aspartate shuttle (and to a lesser extent, the glycerol-phosphate shuttle) because the inner mitochondrial membrane is impermeable to NADH and NAD. Instead of transferring the generated NADH, a malate dehydrogenase enzyme converts oxaloacetate to malate, which is translocated to the mitochondrial matrix. Another malate dehydrogenase-catalyzed reaction occurs in the opposite direction, producing oxaloacetate and NADH from the newly transported malate and the mitochondrion's interior store of NAD. A transaminase converts the oxaloacetate to aspartate for transport back across the membrane and into the intermembrane space.


title: Adenosine triphosphate

text: In oxidative phosphorylation, the passage of electrons from NADH and FADH through the electron transport chain releases the energy to pump protons out of the mitochondrial matrix and into the intermembrane space. This pumping generates a proton motive force that is the net effect of a pH gradient and an electric potential gradient across the inner mitochondrial membrane. Flow of protons down this potential gradient – that is, from the intermembrane space to the matrix – yields ATP by ATP synthase. Three ATP are produced per turn.


title: Adenosine triphosphate

text: Although oxygen consumption appears fundamental for the maintenance of the proton motive force, in the event of oxygen shortage (hypoxia), intracellular acidosis (mediated by enhanced glycolytic rates and ATP hydrolysis), contributes to mitochondrial membrane potential and directly drives ATP synthesis.


title: Adenosine triphosphate

text: Most of the ATP synthesized in the mitochondria will be used for cellular processes in the cytosol; thus it must be exported from its site of synthesis in the mitochondrial matrix. ATP outward movement is favored by the membrane's electrochemical potential because the cytosol has a relatively positive charge compared to the relatively negative matrix. For every ATP transported out, it costs 1 H. Producing one ATP costs about 3 H. Therefore, making and exporting one ATP requires 4H The inner membrane contains an antiporter, the ADP/ATP translocase, which is an integral membrane protein used to exchange newly synthesized ATP in the matrix for ADP in the intermembrane space. This translocase is driven by the membrane potential, as it results in the movement of about 4 negative charges out across the mitochondrial membrane in exchange for 3 negative charges moved inside. However, it is also necessary to transport phosphate into the mitochondrion; the phosphate carrier moves a proton in with each phosphate, partially dissipating the proton gradient. After completing glycolysis, the citric acid cycle, the electron transport chain, and oxidative phosphorylation, approximately 30–38 ATP molecules are produced per glucose.


title: Adenosine triphosphate

text: The citric acid cycle is regulated mainly by the availability of key substrates, particularly the ratio of NAD to NADH and the concentrations of calcium, inorganic phosphate, ATP, ADP, and AMP. Citrate – the ion that gives its name to the cycle – is a feedback inhibitor of citrate synthase and also inhibits PFK, providing a direct link between the regulation of the citric acid cycle and glycolysis.


title: Adenosine triphosphate

text: In the presence of air and various cofactors and enzymes, fatty acids are converted to acetyl-CoA. The pathway is called beta-oxidation. Each cycle of beta-oxidation shortens the fatty acid chain by two carbon atoms and produces one equivalent each of acetyl-CoA, NADH, and FADH. The acetyl-CoA is metabolized by the citric acid cycle to generate ATP, while the NADH and FADH are used by oxidative phosphorylation to generate ATP. Dozens of ATP equivalents are generated by the beta-oxidation of a single long acyl chain.


title: Adenosine triphosphate

text: In oxidative phosphorylation, the key control point is the reaction catalyzed by cytochrome c oxidase, which is regulated by the availability of its substrate – the reduced form of cytochrome c. The amount of reduced cytochrome c available is directly related to the amounts of other substrates:


title: Adenosine triphosphate

text: Thus, a high ratio of [NADH] to [NAD] or a high ratio of [ADP][P] to [ATP] imply a high amount of reduced cytochrome c and a high level of cytochrome c oxidase activity. An additional level of regulation is introduced by the transport rates of ATP and NADH between the mitochondrial matrix and the cytoplasm.


title: Adenosine triphosphate

text: Ketone bodies can be used as fuels, yielding 22 ATP and 2 GTP molecules per acetoacetate molecule when oxidized in the mitochondria. Ketone bodies are transported from the liver to other tissues, where acetoacetate and "beta"-hydroxybutyrate can be reconverted to acetyl-CoA to produce reducing equivalents (NADH and FADH), via the citric acid cycle. Ketone bodies cannot be used as fuel by the liver, because the liver lacks the enzyme β-ketoacyl-CoA transferase, also called thiolase. Acetoacetate in low concentrations is taken up by the liver and undergoes detoxification through the methylglyoxal pathway which ends with lactate. Acetoacetate in high concentrations is absorbed by cells other than those in the liver and enters a different pathway via 1,2-propanediol. Though the pathway follows a different series of steps requiring ATP, 1,2-propanediol can be turned into pyruvate.


title: Adenosine triphosphate

text: Fermentation is the metabolism of organic compounds in the absence of air. It involves substrate-level phosphorylation in the absence of a respiratory electron transport chain. The equation for the reaction of glucose to form lactic acid is:


title: Adenosine triphosphate

text: Anaerobic respiration is respiration in the absence of . Prokaryotes can utilize a variety of electron acceptors. These include nitrate, sulfate, and carbon dioxide.


title: Adenosine triphosphate

text: ATP can also be synthesized through several so-called "replenishment" reactions catalyzed by the enzyme families of nucleoside diphosphate kinases (NDKs), which use other nucleoside triphosphates as a high-energy phosphate donor, and the family.


title: Adenosine triphosphate

text: In plants, ATP is synthesized in the thylakoid membrane of the chloroplast. The process is called photophosphorylation. The "machinery" is similar to that in mitochondria except that light energy is used to pump protons across a membrane to produce a proton-motive force. ATP synthase then ensues exactly as in oxidative phosphorylation. Some of the ATP produced in the chloroplasts is consumed in the Calvin cycle, which produces triose sugars.


title: Adenosine triphosphate

text: The total quantity of ATP in the human body is about 0.1 mol/L. The majority of ATP is recycled from ADP by the aforementioned processes. Thus, at any given time, the total amount of ATP + ADP remains fairly constant.


title: Adenosine triphosphate

text: The energy used by human cells in an adult requires the hydrolysis of 100 to 150 mol/L of ATP daily, which means a human will typically use their body weight worth of ATP over the course of the day. Each equivalent of ATP is recycled 1000–1500 times during a single day (), at approximately 9×10 molecules/s.


title: Adenosine triphosphate

text: ATP is involved in signal transduction by serving as substrate for kinases, enzymes that transfer phosphate groups. Kinases are the most common ATP-binding proteins. They share a small number of common folds. Phosphorylation of a protein by a kinase can activate a cascade such as the mitogen-activated protein kinase cascade.


title: Adenosine triphosphate

text: ATP is also a substrate of adenylate cyclase, most commonly in G protein-coupled receptor signal transduction pathways and is transformed to second messenger, cyclic AMP, which is involved in triggering calcium signals by the release of calcium from intracellular stores. This form of signal transduction is particularly important in brain function, although it is involved in the regulation of a multitude of other cellular processes.


title: Adenosine triphosphate

text: ATP is one of four monomers required in the synthesis of RNA. The process is promoted by RNA polymerases. A similar process occurs in the formation of DNA, except that ATP is first converted to the deoxyribonucleotide dATP. Like many condensation reactions in nature, DNA replication and DNA transcription also consume ATP.


title: Adenosine triphosphate

text: Aminoacyl-tRNA synthetase enzymes consume ATP in the attachment tRNA to amino acids, forming aminoacyl-tRNA complexes. Aminoacyl transferase binds AMP-amino acid to tRNA. The coupling reaction proceeds in two steps:


title: Adenosine triphosphate

text: The amino acid is coupled to the penultimate nucleotide at the 3′-end of the tRNA (the A in the sequence CCA) via an ester bond (roll over in illustration).


title: Adenosine triphosphate

text: Transporting chemicals out of a cell against a gradient is often associated with ATP hydrolysis. Transport is mediated by ATP binding cassette transporters. The human genome encodes 48 ABC transporters, that are used for exporting drugs, lipids, and other compounds.


title: Adenosine triphosphate

text: Cells secrete ATP to communicate with other cells in a process called purinergic signalling. ATP serves as a neurotransmitter in many parts of the nervous system, modulates ciliary beating, affects vascular oxygen supply etc. ATP is either secreted directly across the cell membrane through channel proteins or is pumped into vesicles which then fuse with the membrane. Cells detect ATP using the purinergic receptor proteins P2X and P2Y.


title: Adenosine triphosphate

text: ATP has recently been proposed to act as a biological hydrotrope and has been shown to affect proteome-wide solubility.


title: Adenosine triphosphate

text: Biochemistry laboratories often use "in vitro" studies to explore ATP-dependent molecular processes. ATP analogs are also used in X-ray crystallography to determine a protein structure in complex with ATP, often together with other substrates.


title: Adenosine triphosphate

text: Enzyme inhibitors of ATP-dependent enzymes such as kinases are needed to examine the binding sites and transition states involved in ATP-dependent reactions.


title: Adenosine triphosphate

text: Most useful ATP analogs cannot be hydrolyzed as ATP would be; instead, they trap the enzyme in a structure closely related to the ATP-bound state. Adenosine 5′-(γ-thiotriphosphate) is an extremely common ATP analog in which one of the gamma-phosphate oxygens is replaced by a sulfur atom; this anion is hydrolyzed at a dramatically slower rate than ATP itself and functions as an inhibitor of ATP-dependent processes. In crystallographic studies, hydrolysis transition states are modeled by the bound vanadate ion.


title: Adenosine triphosphate

text: Caution is warranted in interpreting the results of experiments using ATP analogs, since some enzymes can hydrolyze them at appreciable rates at high concentration.


title: Adenosine triphosphate

text: ATP was discovered in 1929 by Karl Lohmann and Jendrassik and, independently, by Cyrus Fiske and Yellapragada Subba Rao of Harvard Medical School, both teams competing against each other to find an assay for phosphorus.


title: Adenosine triphosphate

text: It was proposed to be the intermediary between energy-yielding and energy-requiring reactions in cells by Fritz Albert Lipmann in 1941.


title: Adenosine triphosphate

text: It was first synthesized in the laboratory by Alexander Todd in 1948, and he was awarded the Nobel Prize in Chemistry in 1957 partly for this work.


title: Adenosine triphosphate

text: The 1978 Nobel Prize in Chemistry was awarded to Dr. Peter Dennis Mitchell for the discovery of the chemiosmotic mechanism of ATP synthesis.


title: Adenosine triphosphate

text: The Nobel Prize in Chemistry 1997 was divided, one half jointly to Paul D. Boyer and John E. Walker "for their elucidation of the enzymatic mechanism underlying the synthesis of adenosine triphosphate (ATP)" and the other half to Jens C. Skou "for the first discovery of an ion-transporting enzyme, Na, K -ATPase."


title: George Eliot

text: Mary Ann Evans (22 November 1819 – 22 December 1880; alternatively Mary Anne or Marian), known by her pen name George Eliot, was an English novelist, poet, journalist, translator, and one of the leading writers of the Victorian era. She wrote seven novels: "Adam Bede" (1859), "The Mill on the Floss" (1860), "Silas Marner" (1861), "Romola" (1862–63), "Felix Holt, the Radical" (1866), "Middlemarch" (1871–72) and "Daniel Deronda" (1876). Like Charles Dickens and Thomas Hardy, she emerged from provincial England; most of her works are set there. Her works are known for their realism, psychological insight, sense of place and detailed depiction of the countryside.


title: George Eliot

text: "Middlemarch" was described by the novelist Virginia Woolf as "one of the few English novels written for grown-up people" and by Martin Amis and Julian Barnes as the greatest novel in the English language.


title: George Eliot

text: Mary Ann Evans was born in Nuneaton, Warwickshire, England. She was the third child of Robert Evans (1773–1849) and Christiana Evans ("née" Pearson, 1788–1836), the daughter of a local mill-owner. She spelled her name differently at different times: Mary Anne was the spelling used by her father for the baptismal record and she uses this spelling in her earliest letters. Within her family, however, it was spelled Mary Ann. By 1852, she had changed to Marian, but she reverted to Mary Ann in 1880 after she married John Cross. Mary Ann Cross (George Eliot) appears on her memorial stone.


title: George Eliot

text: Her full siblings were Christiana, known as Chrissey (1814–59), Isaac (1816–1890), and twin brothers who died a few days after birth in March 1821. She also had a half-brother, Robert Evans (1802–64), and half-sister, Frances "Fanny" Evans Houghton (1805–82), from her father's previous marriage to Harriet Poynton (1780-1809). Her father Robert Evans, of Welsh ancestry, was the manager of the Arbury Hall Estate for the Newdigate family in Warwickshire, and Mary Ann was born on the estate at South Farm. In early 1820 the family moved to a house named Griff House, between Nuneaton and Bedworth.


title: George Eliot

text: The young Evans was a voracious reader and obviously intelligent. Because she was not considered physically beautiful, Evans was not thought to have much chance of marriage, and this, coupled with her intelligence, led her father to invest in an education not often afforded women. From ages five to nine, she boarded with her sister Chrissey at Miss Latham's school in Attleborough, from ages nine to thirteen at Mrs. Wallington's school in Nuneaton, and from ages 13 to 16 at Miss Franklin's school in Coventry. At Mrs. Wallington's school, she was taught by the evangelical Maria Lewis—to whom her earliest surviving letters are addressed. In the religious atmosphere of the Misses Franklin's school, Evans was exposed to a quiet, disciplined belief opposed to evangelicalism.


title: George Eliot

text: After age sixteen, Evans had little formal education. Thanks to her father's important role on the estate, she was allowed access to the library of Arbury Hall, which greatly aided her self-education and breadth of learning. Her classical education left its mark; Christopher Stray has observed that "George Eliot's novels draw heavily on Greek literature (only one of her books can be printed correctly without the use of a Greek typeface), and her themes are often influenced by Greek tragedy". Her frequent visits to the estate also allowed her to contrast the wealth in which the local landowner lived with the lives of the often much poorer people on the estate, and different lives lived in parallel would reappear in many of her works. The other important early influence in her life was religion. She was brought up within a low church Anglican family, but at that time the Midlands was an area with a growing number of religious dissenters.