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permits students to work with teachers and their courses over the internet. This can be used in cooperation with, or in place of traditional classroom instruction. The online learning can be also paid for by accessing ESA’s and vouchers. Customized Learning This form of tutelage is a student-tailored form of education. This form of instruction can have various combinations. For example, course choice programs, public school courses, and special education therapies can all be integrated into a student's curriculum. There are a myriad of possibilities, especially as learning innovations continue to occur. Debate Support The goal of school choice programs is to give parents more control over their child's education and to allow parents to pursue the most appropriate learning environments for children. For example, school choice may enable parents to choose a school that provides religious instruction, stronger discipline, better foundational skills (including reading, writing, mathematics, and science), everyday skills (from handling money to farming), or other desirable traits. Supporters of voucher models of school choice argue that choice creates competition between schools for students. Schools that fail to attract students can be closed. Advocates of school choice argue that this competition for students (and the dollars that come with them) create a catalyst for schools to create innovative programs, become more responsive to parental demands, and to increase student achievement. Caroline Hoxby suggests that this competition increases the productivity of a school. Hoxby describes a productive school as being one that produces high student achievement for each dollar spent. Others suggest that this competition gives parents more power to influence their child's school in the school marketplace. Parents and students become the consumers and schools must work to attract new students with new programs. Parents also have the ability to punish schools that they judge to be inferior by leaving the 'bad' school for a better, more highly ranked school. Parents look for schools that will advocate for the needs of their child and if the school does not meet the needs required for that child, parents have the choice to find a school that will be more suitable. This freedom to choose puts the consequences of good or bad choosing on the parents instead of the government. Another argument in favor of school choice is based on cost-effectiveness. Studies undertaken by the Cato Institute and other libertarian and conservative think tanks claim that privately run education both costs less and produces superior outcomes compared to public education. Others argue that since children from impoverished families almost exclusively attend D- or F-ranked public schools, school choice programs would give parents the power to opt their children out of poorly-performing schools assigned by zip code and seek better education elsewhere. Supporters say this would level the playing field by broadening opportunities for low-income students—particularly minorities—to attend high-quality schools that would otherwise be accessible only to higher-income families. Proponents also argue school choice programs improve mental health. One study found that states that adopted charter school laws experienced a decline in adolescent suicides, and that private schooling reduces the likelihood of adults reporting mental health issues. Its supporters also believe it can reduce the negative effects from bullying because families could choose to send their kids to a different school if they are experiencing bullying. The "Organisation Internationale pour le Droit à l'Education et la Liberté d'Enseignement (OIDEL)" -- () -- an international non-profit organization for the development of freedom of education, maintains that the right to education is a fundamental human right which cannot exist without the presence of State benefits and the protection of individual liberties. According to the organization, freedom of education notably implies the freedom for parents to choose a school for their children without discrimination on the basis of finances. To advance freedom of education, OIDEL promotes a greater parity between public and private schooling systems. The Walton Foundation has also held charter school investment conferences featuring Standard & Poor's, Piper Jaffray, Bank of America, and Wells Capital Management. Opposition Teachers' unions in the United States are very opposed to school choice. School choice measures are criticized as profiteering in an under-regulated environment. Charter authorization organizations have non-profit status; and contract with related for-profit entities with public funding. Reports indicate that charters create organizational arms that profit by charging high rent, and that while the facilities are used as schools, there are no property taxes. Public school entities are chiefly concerned that these school choice measures are taking funding away from public schools and therefore depleting their already strained resources. Other opponents of certain school choice policies (particularly vouchers) have cited the Establishment Clause and individual state Blaine amendments, which forbid, to one degree or another, the use of direct government aid to religiously affiliated entities. This is of particular concern in the voucher debate because voucher dollars are often spent at parochial schools. Some school choice measures are criticized by public school entities, organizations opposed to church-state entanglement, and self-identified liberal advocacy groups. Plaintiffs who have filed suit to challenge the constitutionality of state-sponsored school choice laws include school boards associations, public school districts, federations for teachers, associations of school business officials, unions for public school teachers, the American Civil Liberties Union, the Freedom From Religion Foundation, and People for the American Way. School choice has been criticized for aiming to privatize schooling. There is evidence that school choice programs reduce housing prices, and that they do so in high-performing districts more than in low-performing districts. International overview and major institutional options Belgium According to the OECD, the Flemish Community of Belgium has a high-performing education system as measured by PISA scores. Most private schools are considered "government-dependent" and subject to government targets and inspections. Schools are not allowed to select students based on results of admissions tests, performance, religious background, or gender. The Flemish education system benefits from the advantages of school choice, such as the choice between teaching styles and competition, while suffering from relatively high socio-economic segregation. Finland The basic compulsory educational system in Finland is the nine-year comprehensive school (Finnish peruskoulu, Swedish grundskola, "basic school"), for which school attendance is mandatory (homeschooling is allowed, but extremely rare). There are no so-called "gifted" programs. The more able children are expected to help those who are slower to catch on. France The French government subsidizes most private primary and secondary schools, including those affiliated with religious denominations, under contracts stipulating that education must follow the same curriculum as public schools and that schools cannot discriminate on grounds of religion or force pupils to attend religion classes. This system of école libre (Free Schooling) is mostly used not for religious reasons, but for practical reasons (private schools may offer more services, such as after-class tutoring) as well as the desire of parents living in disenfranchised areas to send their children away from the local schools, where they perceive that the youth are too prone to delinquency or have too many difficulties keeping up with schooling requirements that the educational content is bound to suffer. The threatened repealing of that status in the 1980s triggered mass street demonstrations (fr) in favor of the status. Sweden Sweden reformed its school system in 1992. Its system of school choice is one of the freest in the world, allowing students to use public funds for the publicly or privately run school of their choice, including religious and for-profit schools. Fifteen years after the reform, private school enrollment had increased from 1% to 10% of the student population. Chile In Chile, there is an extensive voucher system in which the state pays private and municipal schools directly, based on average attendance (90% of the country's students utilize such a system). The result has been a steady increase in the number and recruitment of private schools that show consistently better results in standardized testing than municipal schools. The reduction of students in municipal schools has gone from 78% of all students in 1981, to 57% in 1990, and to less than 50% in 2005. Regarding vouchers in Chile, researchers have found that when controls for the student's background (parental income and education) are introduced, the difference in performance between public and private subsectors is not significant. There is also greater variation within each subsector than between the two systems. United States A variety of forms of school choice exist in the United States. It is a highly debatable subject because some people wish to use taxpayer dollars in order to allow low-income students the choice of private schools by way of vouchers. Scholarship tax credits Scholarship tax credit programs currently exist in Alabama, Arizona, Florida, Georgia, Illinois, Iowa, Kansas, Louisiana, Minnesota, New Hampshire, Oklahoma, Pennsylvania, Rhode Island, and Virginia. Arizona has a well-known and fast-growing tax credit program. In the Arizona Individual Private School Tuition Tax Credit Program, in accordance with A.R.S. §43-1089 and §1089.03, individuals can claim up to $1,053 and couples filing joint returns can claim up to $2106 (for 2014, amounts are indexed annually). Nearly 24,000 children received scholarships in the 2011-2012 school year. Since the program has started in 1998, over 77,500 taxpayers have participated in the program, providing over $500 million in scholarship money for children at private schools across the state. The Arizona program was challenged in court in ACSTO v Winn by a group of state taxpayers on the grounds that the tax credit violated the First Amendment because the tuition grants could go to students who attend private schools with religious affiliations. The suit was initially brought against the state until the Arizona Christian School Tuition Organization (ACSTO), one of the largest School Tuition Organizations in the state, voluntarily stepped in to represent the defense with the help of the Alliance Defending Freedom (formerly Alliance Defense Fund).	California public school district to enroll students outside district lines. To participate in the program, district governing boards only need to declare themselves a District of Choice and set a quota for how many transfer students to accept to participate in the program. School districts cannot discriminate among students to enroll but can limit them through an unbiased lottery system. The program was created in response to several parents' concerns over the lack of choice of schools to enroll their children in. Currently 47 school districts and 10,000 students participate in the program, serving 5 percent of school districts and 0.2 percent of students in California. Education Savings Accounts This variant of school choice allows the parent to withdraw their child out of the public or charter school, and receive a direct deposit of public funds into a government-authorized savings account. These funds are often distributed in the form of a debit card that can be used to pay for various services, such as private school tuition and fees, online programs, private tutoring, community college costs, higher education services, and other approved learning materials and services. ESA’s also acquire the ability to pay for a combination of public school courses and private services. Tax credit/deduction for educational expenses Certain states allow parents to claim a tax credit or deduction as a means to provide relief for certain educational expenses. These can include private school tuition, textbooks, school supplies and equipment, tutoring, and transportation. Currently, Alabama, Illinois, Indiana, Iowa, Louisiana, Minnesota, and Wisconsin have such programs. Individual Tax Credit and Deduction Option This form of choice abates the income tax for parents, so approved educational expenses can be more economical. Approved educational expenses include private school tuition, supplies, computers, books, tutors, and transportation. Online Learning Online learning permits students to work with teachers and their courses over the internet. This can be used in cooperation with, or in place of traditional classroom instruction. The online learning can be also paid for by accessing ESA’s and vouchers. Customized Learning This form of tutelage is a student-tailored form of education. This form of instruction can have various combinations. For example, course choice programs, public school courses, and special education therapies can all be integrated into a student's curriculum. There are a myriad of possibilities, especially as learning innovations continue to occur. Debate Support The goal of school choice programs is to give parents more control over their child's education and to allow parents to pursue the most appropriate learning environments for children. For example, school choice may enable parents to choose a school that provides religious instruction, stronger discipline, better foundational skills (including reading, writing, mathematics, and science), everyday skills (from handling money to farming), or other desirable traits. Supporters of voucher models of school choice argue that choice creates competition between schools for students. Schools that fail to attract students can be closed. Advocates of school choice argue that this competition for students (and the dollars that come with them) create a catalyst for schools to create innovative programs, become more responsive to parental demands, and to increase student achievement. Caroline Hoxby suggests that this competition increases the productivity of a school. Hoxby describes a productive school as being one that produces high student achievement for each dollar spent. Others suggest that this competition gives parents more power to influence their child's school in the school marketplace. Parents and students become the consumers and schools must work to attract new students with new programs. Parents also have the ability to punish schools that they judge to be inferior by leaving the 'bad' school for a better, more highly ranked school. Parents look for schools that will advocate for the needs of their child and if the school does not meet the needs required for that child, parents have the choice to find a school that will be more suitable. This freedom to choose puts the consequences of good or bad choosing on the parents instead of the government. Another argument in favor of school choice is based on cost-effectiveness. Studies undertaken by the Cato Institute and other libertarian and conservative think tanks claim that privately run education both costs less and produces superior outcomes compared to public education. Others argue that since children from impoverished families almost exclusively attend D- or F-ranked public schools, school choice programs would give parents the power to opt their children out of poorly-performing schools assigned by zip code and seek better education elsewhere. Supporters say this would level the playing field by broadening opportunities for low-income students—particularly minorities—to attend high-quality schools that would otherwise be accessible only to higher-income families. Proponents also argue school choice programs improve mental health. One study found that states that adopted charter school laws experienced a decline in adolescent suicides, and that private schooling reduces the likelihood of adults reporting mental health issues. Its supporters also believe it can reduce the negative effects from bullying because families could choose to send their kids to a different school if they are experiencing bullying. The "Organisation Internationale pour le Droit à l'Education et la Liberté d'Enseignement (OIDEL)" -- () -- an international non-profit organization for the development of freedom of education, maintains that the right to education is a fundamental human right which cannot exist without the presence of State benefits and the protection of individual liberties. According to the organization, freedom of education notably implies the freedom for parents to choose a school for their children without discrimination on the basis of finances. To advance freedom of education, OIDEL promotes a greater parity between public and private schooling systems. The Walton Foundation has also held charter school investment conferences featuring Standard & Poor's, Piper Jaffray, Bank of America, and Wells Capital Management. Opposition Teachers' unions in the United States are very opposed to school choice. School choice measures are criticized as profiteering in an under-regulated environment. Charter authorization organizations have non-profit status; and contract with related for-profit entities with public funding. Reports indicate that charters create organizational arms that profit by charging high rent, and that while the facilities are used as schools, there are no property taxes. Public school entities are chiefly concerned that these school choice measures are taking funding away from public schools and therefore depleting their already strained resources. Other opponents of certain school choice policies (particularly vouchers) have cited the Establishment Clause and individual state Blaine amendments, which forbid, to one degree or another, the use of direct government aid to religiously affiliated entities. This is of particular concern in the voucher debate because voucher dollars are often spent at parochial schools. Some school choice measures are criticized by public school entities, organizations opposed to church-state entanglement, and self-identified liberal advocacy groups. Plaintiffs who have filed suit to challenge the constitutionality of state-sponsored school choice laws include school boards associations, public school districts, federations for teachers, associations of school business officials, unions for public school teachers, the American Civil Liberties Union, the Freedom From Religion Foundation, and People for the American Way. School choice has been criticized for aiming to privatize schooling. There is evidence that school choice programs reduce housing prices, and that they do so in high-performing districts more than in low-performing districts. International overview and major institutional options Belgium According to the OECD, the Flemish Community of Belgium has a high-performing education system as measured by PISA scores. Most private schools are considered "government-dependent" and subject to government targets and inspections. Schools are not allowed to select students based on results of admissions tests, performance, religious background, or gender. The Flemish education system benefits from the advantages of school choice, such as the choice between teaching styles and competition, while suffering from relatively high socio-economic segregation. Finland The basic compulsory educational system in Finland is the nine-year comprehensive school (Finnish peruskoulu, Swedish grundskola, "basic school"), for which school attendance is mandatory (homeschooling is allowed, but extremely rare). There are no so-called "gifted" programs. The more able children are expected to help those who are slower to catch on. France The French government subsidizes most private primary and secondary schools, including those affiliated with religious denominations, under contracts stipulating that education must follow the same curriculum as public schools and that schools cannot discriminate on grounds of religion or force pupils to attend religion classes. This system of école libre (Free Schooling) is mostly used not for religious reasons, but for practical reasons (private schools may offer more services, such as after-class tutoring) as well as the desire of parents living in disenfranchised areas to send their children away from the local schools, where they perceive that the youth are too prone to delinquency or have too many difficulties keeping up with schooling requirements that the educational content is bound to suffer. The threatened repealing of that status in the 1980s triggered mass street demonstrations (fr) in favor of the status. Sweden Sweden reformed its school system in 1992. Its system of school choice is one of the freest in the world, allowing students to use public funds for the publicly or privately run school of their choice, including religious and for-profit schools. Fifteen years after the reform, private school enrollment had increased from 1% to 10% of the student population. Chile In Chile, there is an extensive voucher system in which the state pays private and municipal schools directly, based on average attendance (90% of the country's students utilize such a system). The result has been a steady increase in the number and recruitment of private schools that show consistently better results in standardized testing than municipal schools. The reduction of students in municipal schools has gone from 78% of all students in 1981, to 57% in 1990, and to
of the Frontier sector in the basic rulebook were unexplored and undetailed, allowing the Gamemaster (called the "referee" in the game) to put whatever they wished there. Players could take on any number of possible roles in the setting but the default was to act as hired agents of the Pan Galactic corporation in exploring the Frontier and fighting the aggressive incursions of the alien and mysterious worm-like race known as the Sathar. Most published modules for the game followed these themes. Sapient races Dralasites are short, gray amoeboid-like creatures (they are actually multi-cellular unlike true amoebas) capable of changing their form to a limited extent by extending and retracting pseudopods. Lacking a digestive system, they consume their food by surrounding and absorbing it. A network of nerves and veins intersects at a Dralasite's two eye spots. They cannot see colors, but have a well-developed sense of smell. They have a sense of humor that the other races often find strange or quirky, and a love of bad puns. Humans are a race of beings virtually identical to Earthly humans but with 200-year lifespan (possibly due to the advanced technology of the setting). Vrusk are an insectoid race with eight walking legs and two five-clawed manipulating arms. Their ant-like heads included two antennae and two mandibles. They are omnivorous. They are noted for their logical minds and their society is structured as commercial ventures. Many Vrusk give their company name before their given name. The Yazirian race are anthropoids similar to various terrestrial apes. They are muzzled, lightly furred, and have patagia stretching between their arms and legs which they can use to glide over short distances in low gravity (their home worlds are all low-gravity). They are descended from a nocturnal species, and prefer to wear tinted goggles to protect their eyesight during the day. They are said to be rather violent and pushy, and have a custom to choose a "life-enemy", which could be anything; a company, person, or a concept. The fictional species was rehashed as Shadow People in TSR's later Dragonlance series of campaign modules and also as the Hadozee race presented first in Spelljammer and secondly in Stormwrack. Yazirians share several points with the High Martians of GDW's later Space: 1889 RPG. Yazirians, like Wookiees in Star Wars and certain game depictions of fantasy Barbarians, have a "battle rage" or a berserker state of mind. These races were altered heavily and reused in TSR's Spelljammer, and were later loosely republished for d20 Future by Wizards of the Coast. The Sathar are a race of mysterious, worm-like beings who are the enemies of the UPF (they are not intended to be used as a player race). They have wormlike bodies of 3 to 4 meters in length with two tentacular arms that end in fine tentacles for manipulation and two tentacles that end in paddles that can be used for heavy lifting (including acting as "legs", lifting the front of the creature off the ground in a humanoid-like stance). Their eyes have two pupils each, giving them good peripheral vision. The races of the Frontier know little about them other than their basic anatomy and the fact that they are hostile, as no live Sathar has ever been captured. Some of the behaviors and motives of the Sathar were revealed in the printed adventures for the game, and adventures commonly featured mercenaries working for the Sathar to undermine the UPF as villains. There are also other non-player races in the Star Frontiers universe, including many in the printed modules, but these five are the only races who developed space drive technology within the Frontier. Several new player races appeared in a late addition to the line, Zebulon's Guide to Frontier Space, and include the Humma (which resemble kangaroos), Ifshnit (akin to dwarves), Osakar (lanky, parthenogenic quadrupeds) and Mechanons (intelligent robots). Game mechanics The game was a percentile-based system and used only 10-sided dice (d10). Characters had attributes rated from 1-100 (usually in the 25-75 range) which could be rolled against for raw-attribute actions such as lifting items or getting out of the way of falling rocks. There were eight attributes that were paired together (and shared the same rating to begin with)—Strength/Stamina, Dexterity/Reaction Speed, Intuition/Logic, and Personality/Leadership. Characters also each had a Primary Skill Area (PSA—Military, Technological, or Biosocial) which allowed them to buy skills that fell into their PSA at a discount. Skills were rated from 1–6 and usually consisted of a set of subskills that gave a chance for accomplishing a particular action as a base percentage plus a 10% bonus for each skill level the character had in the skill. Weapon skills were based on the character's relevant attribute (Dexterity or Strength) but other skills	A previously undiscovered quirk of the laws of physics allows starships to jump to "The Void", a hyperspatial realm that greatly shortens the travel times between inhabited worlds, once they reach 1% of the speed of light (3,000 km/s). The basic game setting was an area known as "The Frontier Sector" where four sentient races (Dralasite, Humans, Vrusk, and Yazirian) had met and formed the United Planetary Federation (UPF). The original homeworlds of the Dralasites, Humans, and Vrusk were never detailed in the setting and it is possible that they no longer existed. A large number of the star systems shown on the map of the Frontier sector in the basic rulebook were unexplored and undetailed, allowing the Gamemaster (called the "referee" in the game) to put whatever they wished there. Players could take on any number of possible roles in the setting but the default was to act as hired agents of the Pan Galactic corporation in exploring the Frontier and fighting the aggressive incursions of the alien and mysterious worm-like race known as the Sathar. Most published modules for the game followed these themes. Sapient races Dralasites are short, gray amoeboid-like creatures (they are actually multi-cellular unlike true amoebas) capable of changing their form to a limited extent by extending and retracting pseudopods. Lacking a digestive system, they consume their food by surrounding and absorbing it. A network of nerves and veins intersects at a Dralasite's two eye spots. They cannot see colors, but have a well-developed sense of smell. They have a sense of humor that the other races often find strange or quirky, and a love of bad puns. Humans are a race of beings virtually identical to Earthly humans but with 200-year lifespan (possibly due to the advanced technology of the setting). Vrusk are an insectoid race with eight walking legs and two five-clawed manipulating arms. Their ant-like heads included two antennae and two mandibles. They are omnivorous. They are noted for their logical minds and their society is structured as commercial ventures. Many Vrusk give their company name before their given name. The Yazirian race are anthropoids similar to various terrestrial apes. They are muzzled, lightly furred, and have patagia stretching between their arms and legs which they can use to glide over short distances in low gravity (their home worlds are all low-gravity). They are descended from a nocturnal species, and prefer to wear tinted goggles to protect their eyesight during the day. They are said to be rather violent and pushy, and have a custom to choose a "life-enemy", which could be anything; a company, person, or a concept. The fictional species was rehashed as Shadow People in TSR's later Dragonlance series of campaign modules and also as the Hadozee race presented first in Spelljammer and secondly in Stormwrack. Yazirians share several points with the High Martians of GDW's later Space: 1889 RPG. Yazirians, like Wookiees in Star Wars and certain game depictions of fantasy Barbarians, have a "battle rage" or a berserker state of mind. These races were altered heavily and reused in TSR's Spelljammer, and were later loosely republished for d20 Future by Wizards of the Coast. The Sathar are a race of mysterious, worm-like beings who are the enemies of the UPF (they are not intended to be used as a player race). They have wormlike bodies of 3 to 4 meters in length with two tentacular arms that end in fine tentacles for manipulation and two tentacles that end in paddles that can be used for heavy lifting (including acting as "legs", lifting the front of the creature off the ground in a humanoid-like stance). Their eyes have two pupils each, giving them good peripheral vision. The races of the Frontier know little about them other than their basic anatomy and the fact that they are hostile, as no live Sathar has ever been captured. Some of the behaviors and motives of the Sathar were revealed in the printed adventures for the game, and adventures commonly featured mercenaries working for the Sathar to undermine the UPF as villains. There are also other non-player races in the Star Frontiers universe, including many in the printed modules, but these five are the only races who developed space drive technology within the Frontier. Several new player races appeared in a late addition to the line, Zebulon's Guide to Frontier Space, and include the Humma (which resemble kangaroos), Ifshnit (akin to dwarves), Osakar (lanky, parthenogenic quadrupeds) and Mechanons (intelligent robots). Game mechanics The game was a percentile-based system and used only 10-sided dice (d10). Characters had attributes rated from 1-100 (usually in the 25-75 range) which could be rolled against for raw-attribute actions such as lifting items or getting out of the way of falling rocks. There were eight attributes that were paired together (and shared the same rating to begin with)—Strength/Stamina, Dexterity/Reaction Speed, Intuition/Logic, and Personality/Leadership. Characters also each had a Primary Skill Area (PSA—Military, Technological, or Biosocial) which allowed them to buy skills that fell into their PSA at a discount. Skills were rated from 1–6 and usually consisted of a set of subskills that gave a chance for accomplishing a particular action as a base percentage plus a 10% bonus for each skill level the character had in the skill. Weapon skills were based
of view and demonstrated how apparently different social organizations were different permutations of a few basic kinship structures. In the late 1950s, he published Structural Anthropology, a collection of essays outlining his program for structuralism. Lacan and Piaget Blending Freud and Saussure, French (post)structuralist Jacques Lacan applied structuralism to psychoanalysis. Similarly, Jean Piaget applied structuralism to the study of psychology, though in a different way. Piaget, who would better define himself as constructivist, considered structuralism as "a method and not a doctrine," because, for him, "there exists no structure without a construction, abstract or genetic." 'Third order' Proponents of structuralism argue that a specific domain of culture may be understood by means of a structure that is modelled on language and is distinct both from the organizations of reality and those of ideas, or the imagination—the "third order." In Lacan's psychoanalytic theory, for example, the structural order of "the Symbolic" is distinguished both from "the Real" and "the Imaginary;" similarly, in Althusser's Marxist theory, the structural order of the capitalist mode of production is distinct both from the actual, real agents involved in its relations and from the ideological forms in which those relations are understood. Althusser Although French theorist Louis Althusser is often associated with structural social analysis, which helped give rise to "structural Marxism," such association was contested by Althusser himself in the Italian foreword to the second edition of Reading Capital. In this foreword Althusser states the following: Despite the precautions we took to distinguish ourselves from the 'structuralist' ideology…, despite the decisive intervention of categories foreign to 'structuralism'…, the terminology we employed was too close in many respects to the 'structuralist' terminology not to give rise to an ambiguity. With a very few exceptions…our interpretation of Marx has generally been recognized and judged, in homage to the current fashion, as 'structuralist'.… We believe that despite the terminological ambiguity, the profound tendency of our texts was not attached to the 'structuralist' ideology. Assiter In a later development, feminist theorist Alison Assiter enumerated four ideas common to the various forms of structuralism: a structure determines the position of each element of a whole; every system has a structure; structural laws deal with co-existence rather than change; and structures are the "real things" that lie beneath the surface or the appearance of meaning. In linguistics In Ferdinand de Saussure's Course in General Linguistics, the analysis focuses not on the use of language (parole, 'speech'), but rather on the underlying system of language (langue). This approach examines how the elements of language relate to each other in the present, synchronically rather than diachronically. Saussure argued that linguistic signs were composed of two parts: a signifiant ('signifier'): the "sound pattern" of a word, either in mental projection—e.g., as when one silently recites lines from signage, a poem to one's self—or in actual, any kind of text, physical realization as part of a speech act. a signifié '(signified'): the concept or meaning of the word. This differed from previous approaches that focused on the relationship between words and the things in the world that they designate. Although not fully developed by Saussure, other key notions in structural linguistics can be found in structural "idealism." A structural idealism is a class of linguistic units (lexemes, morphemes, or even constructions) that are possible in a certain position in a given syntagm, or linguistic environment (such as a given sentence). The different functional role of each of these members of the paradigm is called 'value' (French: ). Prague School In France, Antoine Meillet and Émile Benveniste continued Saussure's project, and members of the Prague school of linguistics such as Roman Jakobson and Nikolai Trubetzkoy conducted influential research. The clearest and most important example of Prague school structuralism lies in phonemics. Rather than simply compiling a list of which sounds occur in a language, the Prague school examined how they were related. They determined that the inventory of sounds in a language could be analysed as a series of contrasts. Thus, in English, the sounds /p/ and /b/ represent distinct phonemes because there are cases (minimal pairs) where the contrast between the two is the only difference between two distinct words (e.g. 'pat' and 'bat'). Analyzing sounds in terms of contrastive features also opens up comparative scope—for instance, it makes clear the difficulty Japanese speakers have differentiating /r/ and /l/ in English and other languages is because these sounds are not contrastive in Japanese. Phonology would become the paradigmatic basis for structuralism in a number of different fields. Based on the Prague school concept, André Martinet in France, J. R. Firth in the UK and Louis Hjelmslev in Denmark developed their own versions of structural and functional linguistics. In anthropology According to structural theory in anthropology and social anthropology, meaning is produced and reproduced within a culture through various practices, phenomena, and activities that serve as systems of signification. A structuralist approach may study activities as diverse as food-preparation and serving rituals, religious rites, games, literary and non-literary texts, and other forms of entertainment to discover the deep structures by which meaning is produced and reproduced within the culture. For example, Lévi-Strauss analysed in the 1950s cultural phenomena including mythology, kinship (the alliance theory and the incest taboo), and food preparation. In addition to these studies, he produced more linguistically-focused writings in which he applied Saussure's distinction between langue and parole in his search for the fundamental structures of the human mind, arguing that the structures that form the "deep grammar" of society originate in the mind and operate in people unconsciously. Lévi-Strauss took inspiration from mathematics. Another concept used in structural anthropology came from the Prague school of linguistics, where Roman Jakobson and others analysed sounds based on the presence or absence of certain features (e.g., voiceless vs. voiced). Lévi-Strauss included this in his conceptualization of the universal structures of the mind, which he held to operate based on pairs of binary oppositions such as hot-cold, male-female, culture-nature, cooked-raw, or marriageable vs. tabooed women. A third influence came from Marcel Mauss (1872–1950), who had written on gift-exchange systems. Based on Mauss, for instance, Lévi-Strauss argued an alliance theory—that kinship systems are based on the exchange of women between groups—as opposed to the 'descent'-based theory described by Edward Evans-Pritchard and Meyer Fortes. While replacing Mauss at his Ecole Pratique des Hautes Etudes chair, the writings of Lévi-Strauss became widely popular in the 1960s and 1970s and gave rise to the term "structuralism" itself. In Britain, authors such as Rodney Needham and Edmund Leach were highly influenced by structuralism. Authors such as Maurice Godelier and Emmanuel Terray combined Marxism with structural anthropology in France. In the United States, authors such as Marshall Sahlins and James Boon built on structuralism to provide their own analysis of human society. Structural anthropology fell out of favour in the early 1980s for a number of reasons. D'Andrade suggests that this was because it made unverifiable assumptions about the universal structures of the human mind. Authors such as Eric Wolf argued that political economy and colonialism should be at the forefront of anthropology. More generally, criticisms of structuralism by Pierre Bourdieu led to a concern with how cultural and social structures were changed by human agency and practice, a trend which Sherry Ortner has referred to as 'practice theory'. One example is Douglas E. Foley's Learning Capitalist Culture (2010), in which he applied a mixture of structural and Marxist theories to his ethnographic fieldwork among high school students in Texas. Foley analyzed how they reach a shared goal through the lens of social solidarity when he observed "Mexicanos" and "Anglo-Americans" come together on the same football team to defeat the school's rivals. However, he also continually applies a marxist lens and states that he," wanted to wow peers with a new cultural marxist theory of schooling." Some anthropological theorists, however, while finding considerable fault with Lévi-Strauss's version of structuralism, did not turn away from a fundamental structural basis for human	/p/ and /b/ represent distinct phonemes because there are cases (minimal pairs) where the contrast between the two is the only difference between two distinct words (e.g. 'pat' and 'bat'). Analyzing sounds in terms of contrastive features also opens up comparative scope—for instance, it makes clear the difficulty Japanese speakers have differentiating /r/ and /l/ in English and other languages is because these sounds are not contrastive in Japanese. Phonology would become the paradigmatic basis for structuralism in a number of different fields. Based on the Prague school concept, André Martinet in France, J. R. Firth in the UK and Louis Hjelmslev in Denmark developed their own versions of structural and functional linguistics. In anthropology According to structural theory in anthropology and social anthropology, meaning is produced and reproduced within a culture through various practices, phenomena, and activities that serve as systems of signification. A structuralist approach may study activities as diverse as food-preparation and serving rituals, religious rites, games, literary and non-literary texts, and other forms of entertainment to discover the deep structures by which meaning is produced and reproduced within the culture. For example, Lévi-Strauss analysed in the 1950s cultural phenomena including mythology, kinship (the alliance theory and the incest taboo), and food preparation. In addition to these studies, he produced more linguistically-focused writings in which he applied Saussure's distinction between langue and parole in his search for the fundamental structures of the human mind, arguing that the structures that form the "deep grammar" of society originate in the mind and operate in people unconsciously. Lévi-Strauss took inspiration from mathematics. Another concept used in structural anthropology came from the Prague school of linguistics, where Roman Jakobson and others analysed sounds based on the presence or absence of certain features (e.g., voiceless vs. voiced). Lévi-Strauss included this in his conceptualization of the universal structures of the mind, which he held to operate based on pairs of binary oppositions such as hot-cold, male-female, culture-nature, cooked-raw, or marriageable vs. tabooed women. A third influence came from Marcel Mauss (1872–1950), who had written on gift-exchange systems. Based on Mauss, for instance, Lévi-Strauss argued an alliance theory—that kinship systems are based on the exchange of women between groups—as opposed to the 'descent'-based theory described by Edward Evans-Pritchard and Meyer Fortes. While replacing Mauss at his Ecole Pratique des Hautes Etudes chair, the writings of Lévi-Strauss became widely popular in the 1960s and 1970s and gave rise to the term "structuralism" itself. In Britain, authors such as Rodney Needham and Edmund Leach were highly influenced by structuralism. Authors such as Maurice Godelier and Emmanuel Terray combined Marxism with structural anthropology in France. In the United States, authors such as Marshall Sahlins and James Boon built on structuralism to provide their own analysis of human society. Structural anthropology fell out of favour in the early 1980s for a number of reasons. D'Andrade suggests that this was because it made unverifiable assumptions about the universal structures of the human mind. Authors such as Eric Wolf argued that political economy and colonialism should be at the forefront of anthropology. More generally, criticisms of structuralism by Pierre Bourdieu led to a concern with how cultural and social structures were changed by human agency and practice, a trend which Sherry Ortner has referred to as 'practice theory'. One example is Douglas E. Foley's Learning Capitalist Culture (2010), in which he applied a mixture of structural and Marxist theories to his ethnographic fieldwork among high school students in Texas. Foley analyzed how they reach a shared goal through the lens of social solidarity when he observed "Mexicanos" and "Anglo-Americans" come together on the same football team to defeat the school's rivals. However, he also continually applies a marxist lens and states that he," wanted to wow peers with a new cultural marxist theory of schooling." Some anthropological theorists, however, while finding considerable fault with Lévi-Strauss's version of structuralism, did not turn away from a fundamental structural basis for human culture. The Biogenetic Structuralism group for instance argued that some kind of structural foundation for culture must exist because all humans inherit the same system of brain structures. They proposed a kind of neuroanthropology which would lay the foundations for a more complete scientific account of cultural similarity and variation by requiring an integration of cultural anthropology and neuroscience—a program that theorists such as Victor Turner also embraced. In literary criticism and theory In literary theory, structuralist criticism relates literary texts to a larger structure, which may be a particular genre, a range of intertextual connections, a model of a universal narrative structure, or a system of recurrent patterns or motifs. The field of structuralist semiotics argues that there must be a structure in every text, which explains why it is easier for experienced readers than for non-experienced readers to interpret a text. Everything that is written seems to be governed by rules, or "grammar of literature", that one learns in educational institutions and that are to be unmasked. A potential problem for a structuralist interpretation is that it can be highly reductive; as scholar Catherine Belsey puts it: "the structuralist danger of collapsing all difference." An example of such a reading might be if a student concludes the authors of West Side Story did not write anything "really" new, because their work has the same structure as Shakespeare's Romeo and Juliet. In both texts a girl and a boy fall in love (a "formula" with a symbolic operator between them would be "Boy + Girl") despite the fact that they belong to two groups that hate each other ("Boy's Group - Girl's Group" or "Opposing forces") and conflict is resolved by their deaths. Structuralist readings focus on how the structures of the single text resolve inherent narrative tensions. If a structuralist reading focuses on multiple texts, there must be some way in which those texts unify themselves into a coherent system. The versatility of structuralism is such that a literary critic could make the same claim about a story of two friendly families ("Boy's Family + Girl's Family") that arrange a marriage between their children despite the fact that the children hate each other ("Boy - Girl") and then the children commit suicide to escape the arranged marriage; the justification is that the second story's structure is an 'inversion' of the first story's structure: the relationship between the values of love and the two pairs of parties involved have been reversed. Structuralist literary criticism argues that the "literary banter of a text" can lie only in new structure, rather than in the specifics of character development and voice in which that structure is expressed. Literary structuralism often follows the lead of Vladimir Propp, Algirdas Julien Greimas, and Claude Lévi-Strauss in seeking out basic deep elements in stories, myths, and more recently, anecdotes, which are combined in various ways to produce the many versions of the ur-story or ur-myth. There is considerable similarity between structural literary theory and Northrop Frye's archetypal criticism, which is also indebted to the anthropological study of myths. Some critics have also tried to apply the theory to individual works, but the effort to find unique structures in individual literary works runs counter to the structuralist program and has an affinity with New Criticism. In economics Structuralist economics is an approach to economics that emphasizes the importance of taking into account structural features (typically) when undertaking economic analysis. The approach originated with the work of the Economic Commission for Latin America (ECLA or CEPAL) and is primarily associated with its director Raúl Prebisch and Brazilian economist Celso
of the development effort, systems engineering helps mold all the technical contributors into a unified team effort, forming a structured development process that proceeds from concept to production to operation and, in some cases, to termination and disposal. In an acquisition, the holistic integrative discipline combines contributions and balances tradeoffs among cost, schedule, and performance while maintaining an acceptable level of risk covering the entire life cycle of the item. This perspective is often replicated in educational programs, in that systems engineering courses are taught by faculty from other engineering departments, which helps create an interdisciplinary environment. Managing complexity The need for systems engineering arose with the increase in complexity of systems and projects, in turn exponentially increasing the possibility of component friction, and therefore the unreliability of the design. When speaking in this context, complexity incorporates not only engineering systems, but also the logical human organization of data. At the same time, a system can become more complex due to an increase in size as well as with an increase in the amount of data, variables, or the number of fields that are involved in the design. The International Space Station is an example of such a system. The development of smarter control algorithms, microprocessor design, and analysis of environmental systems also come within the purview of systems engineering. Systems engineering encourages the use of tools and methods to better comprehend and manage complexity in systems. Some examples of these tools can be seen here: System architecture, System model, Modeling, and Simulation, Optimization, System dynamics, Systems analysis, Statistical analysis, Reliability analysis, and Decision making Taking an interdisciplinary approach to engineering systems is inherently complex since the behavior of and interaction among system components is not always immediately well defined or understood. Defining and characterizing such systems and subsystems and the interactions among them is one of the goals of systems engineering. In doing so, the gap that exists between informal requirements from users, operators, marketing organizations, and technical specifications is successfully bridged. Scope One way to understand the motivation behind systems engineering is to see it as a method, or practice, to identify and improve common rules that exist within a wide variety of systems. Keeping this in mind, the principles of systems engineering – holism, emergent behavior, boundary, et al. – can be applied to any system, complex or otherwise, provided systems thinking is employed at all levels. Besides defense and aerospace, many information and technology based companies, software development firms, and industries in the field of electronics & communications require systems engineers as part of their team. An analysis by the INCOSE Systems Engineering center of excellence (SECOE) indicates that optimal effort spent on systems engineering is about 15–20% of the total project effort. At the same time, studies have shown that systems engineering essentially leads to reduction in costs among other benefits. However, no quantitative survey at a larger scale encompassing a wide variety of industries has been conducted until recently. Such studies are underway to determine the effectiveness and quantify the benefits of systems engineering. Systems engineering encourages the use of modeling and simulation to validate assumptions or theories on systems and the interactions within them. Use of methods that allow early detection of possible failures, in safety engineering, are integrated into the design process. At the same time, decisions made at the beginning of a project whose consequences are not clearly understood can have enormous implications later in the life of a system, and it is the task of the modern systems engineer to explore these issues and make critical decisions. No method guarantees today's decisions will still be valid when a system goes into service years or decades after first conceived. However, there are techniques that support the process of systems engineering. Examples include soft systems methodology, Jay Wright Forrester's System dynamics method, and the Unified Modeling Language (UML)—all currently being explored, evaluated, and developed to support the engineering decision process. Education Education in systems engineering is often seen as an extension to the regular engineering courses, reflecting the industry attitude that engineering students need a foundational background in one of the traditional engineering disciplines (e.g., aerospace engineering, civil engineering, electrical engineering, mechanical engineering, manufacturing engineering, industrial engineering, chemical engineering)—plus practical, real-world experience to be effective as systems engineers. Undergraduate university programs explicitly in systems engineering are growing in number but remain uncommon, the degrees including such material most often presented as a BS in Industrial Engineering. Typically programs (either by themselves or in combination with interdisciplinary study) are offered beginning at the graduate level in both academic and professional tracks, resulting in the grant of either a MS/MEng or Ph.D./EngD degree. INCOSE, in collaboration with the Systems Engineering Research Center at Stevens Institute of Technology maintains a regularly updated directory of worldwide academic programs at suitably accredited institutions. As of 2017, it lists over 140 universities in North America offering more than 400 undergraduate and graduate programs in systems engineering. Widespread institutional acknowledgment of the field as a distinct subdiscipline is quite recent; the 2009 edition of the same publication reported the number of such schools and programs at only 80 and 165, respectively. Education in systems engineering can be taken as Systems-centric or Domain-centric: Systems-centric programs treat systems engineering as a separate discipline and most of the courses are taught focusing on systems engineering principles and practice. Domain-centric programs offer systems engineering as an option that can be exercised with another major field in engineering. Both of these patterns strive to educate the systems engineer who is able to oversee interdisciplinary projects with the depth required of a core-engineer. Systems engineering topics Systems engineering tools are strategies, procedures, and techniques that aid in performing systems engineering on a project or product. The purpose of these tools vary from database management, graphical browsing, simulation, and reasoning, to document production, neutral import/export and more. System There are many definitions of what a system is in the field of systems engineering. Below are a few authoritative definitions: ANSI/EIA-632-1999: "An aggregation of end products and enabling products to achieve a given purpose." DAU Systems Engineering Fundamentals: "an integrated composite of people, products, and processes that provide a capability to satisfy a stated need or objective." IEEE Std 1220-1998: "A set or arrangement of elements and processes that are related and whose behavior satisfies customer/operational needs and provides for life cycle sustainment of the products." INCOSE Systems Engineering Handbook: "homogeneous entity that exhibits predefined behavior in the real world and is composed of heterogeneous parts that do not individually exhibit that behavior and an integrated configuration of components and/or subsystems." INCOSE: "A system is a construct or collection of different elements that together produce results not obtainable by the elements alone. The elements, or parts, can include people, hardware, software, facilities, policies, and documents; that is, all things required to produce systems-level results. The results include system level qualities, properties, characteristics, functions, behavior and performance. The value added by the system as a whole, beyond that contributed independently by the parts, is primarily created by the relationship among the parts; that is, how they are interconnected." ISO/IEC 15288:2008: "A combination of interacting elements organized to achieve one or more stated purposes." NASA Systems Engineering Handbook: "(1) The combination of elements that function together to produce the capability to meet a need. The elements include all hardware, software, equipment, facilities, personnel, processes, and procedures needed for this purpose. (2) The end product (which performs operational functions) and enabling products (which provide life-cycle support services to the operational end products) that make up a system." Systems engineering processes Systems engineering processes encompass all creative, manual and technical activities necessary to define the product and which need to be carried out to convert a system definition to a sufficiently detailed system design specification for product manufacture and deployment. Design and development of a system can be divided into four stages, each with different definitions: task definition (informative definition), conceptual stage (cardinal definition), design stage (formative definition), and implementation stage (manufacturing definition). Depending on their application, tools are used for various stages of the systems engineering process: Using models Models play important and diverse roles in systems engineering. A model can be defined in several ways, including: An abstraction of reality designed to answer specific questions about the real world An imitation, analogue, or representation of a real world process or structure; or A conceptual, mathematical, or physical tool to assist a decision maker. Together, these definitions are broad enough to encompass physical engineering models used in the verification of a system design, as well as schematic models like a functional flow block diagram and mathematical (i.e., quantitative) models used in the trade study process. This section focuses on the last. The main reason for using mathematical models and diagrams in trade studies is to provide estimates of system effectiveness, performance or technical attributes, and cost from a set of known or estimable quantities. Typically, a collection of separate models is needed to provide all of these outcome variables. The heart of any mathematical model is a set of meaningful quantitative relationships among its inputs and outputs. These relationships can be as simple as adding up constituent quantities to obtain a total, or as complex as a set of differential equations describing the trajectory of a spacecraft in a gravitational field. Ideally, the relationships express causality, not just correlation. Furthermore, key to successful systems engineering activities are also the methods with which these models are efficiently and effectively managed and used to simulate the systems. However, diverse domains often present recurring problems of modeling and simulation for systems engineering, and new advancements are aiming to crossfertilize methods among distinct scientific and engineering communities, under the title of 'Modeling & Simulation-based Systems Engineering'. Modeling formalisms and graphical representations Initially, when the primary purpose of a systems engineer is to comprehend a complex problem, graphic representations of a system are used to communicate a system's functional and data requirements. Common graphical representations include: Functional flow block diagram (FFBD) Model-based design Data flow diagram (DFD) N2 chart IDEF0 diagram Use case diagram Sequence diagram Block diagram Signal-flow graph USL function maps and type maps Enterprise architecture frameworks A graphical representation relates the various subsystems or parts of a system through functions, data, or interfaces. Any or each of the above methods are used in an industry based on its requirements. For instance, the N2 chart may be used where interfaces between systems is important. Part of the design phase is to create structural and behavioral models of the system. Once the requirements are understood, it is now the responsibility of a systems engineer to refine them, and to determine, along with other engineers, the best technology for a job. At this point starting with a trade study, systems engineering encourages the use of weighted choices to determine the best option. A decision matrix, or Pugh method, is one way (QFD is another) to make this choice while considering all criteria that are important. The trade study in turn informs the design, which again affects graphic representations of the system (without changing the requirements). In an SE process, this stage represents the iterative step that is carried out until a feasible solution is found. A decision matrix is often populated using techniques such as statistical analysis, reliability analysis, system dynamics (feedback control), and optimization methods. Other tools Systems Modeling Language (SysML), a modeling language used for systems engineering applications, supports the specification, analysis,	Engineering Management Process. Within Oliver's model, the goal of the Management Process is to organize the technical effort in the lifecycle, while the Technical Process includes assessing available information, defining effectiveness measures, to create a behavior model, create a structure model, perform trade-off analysis, and create sequential build & test plan. Depending on their application, although there are several models that are used in the industry, all of them aim to identify the relation between the various stages mentioned above and incorporate feedback. Examples of such models include the Waterfall model and the VEE model (also called the V model). Interdisciplinary field System development often requires contribution from diverse technical disciplines. By providing a systems (holistic) view of the development effort, systems engineering helps mold all the technical contributors into a unified team effort, forming a structured development process that proceeds from concept to production to operation and, in some cases, to termination and disposal. In an acquisition, the holistic integrative discipline combines contributions and balances tradeoffs among cost, schedule, and performance while maintaining an acceptable level of risk covering the entire life cycle of the item. This perspective is often replicated in educational programs, in that systems engineering courses are taught by faculty from other engineering departments, which helps create an interdisciplinary environment. Managing complexity The need for systems engineering arose with the increase in complexity of systems and projects, in turn exponentially increasing the possibility of component friction, and therefore the unreliability of the design. When speaking in this context, complexity incorporates not only engineering systems, but also the logical human organization of data. At the same time, a system can become more complex due to an increase in size as well as with an increase in the amount of data, variables, or the number of fields that are involved in the design. The International Space Station is an example of such a system. The development of smarter control algorithms, microprocessor design, and analysis of environmental systems also come within the purview of systems engineering. Systems engineering encourages the use of tools and methods to better comprehend and manage complexity in systems. Some examples of these tools can be seen here: System architecture, System model, Modeling, and Simulation, Optimization, System dynamics, Systems analysis, Statistical analysis, Reliability analysis, and Decision making Taking an interdisciplinary approach to engineering systems is inherently complex since the behavior of and interaction among system components is not always immediately well defined or understood. Defining and characterizing such systems and subsystems and the interactions among them is one of the goals of systems engineering. In doing so, the gap that exists between informal requirements from users, operators, marketing organizations, and technical specifications is successfully bridged. Scope One way to understand the motivation behind systems engineering is to see it as a method, or practice, to identify and improve common rules that exist within a wide variety of systems. Keeping this in mind, the principles of systems engineering – holism, emergent behavior, boundary, et al. – can be applied to any system, complex or otherwise, provided systems thinking is employed at all levels. Besides defense and aerospace, many information and technology based companies, software development firms, and industries in the field of electronics & communications require systems engineers as part of their team. An analysis by the INCOSE Systems Engineering center of excellence (SECOE) indicates that optimal effort spent on systems engineering is about 15–20% of the total project effort. At the same time, studies have shown that systems engineering essentially leads to reduction in costs among other benefits. However, no quantitative survey at a larger scale encompassing a wide variety of industries has been conducted until recently. Such studies are underway to determine the effectiveness and quantify the benefits of systems engineering. Systems engineering encourages the use of modeling and simulation to validate assumptions or theories on systems and the interactions within them. Use of methods that allow early detection of possible failures, in safety engineering, are integrated into the design process. At the same time, decisions made at the beginning of a project whose consequences are not clearly understood can have enormous implications later in the life of a system, and it is the task of the modern systems engineer to explore these issues and make critical decisions. No method guarantees today's decisions will still be valid when a system goes into service years or decades after first conceived. However, there are techniques that support the process of systems engineering. Examples include soft systems methodology, Jay Wright Forrester's System dynamics method, and the Unified Modeling Language (UML)—all currently being explored, evaluated, and developed to support the engineering decision process. Education Education in systems engineering is often seen as an extension to the regular engineering courses, reflecting the industry attitude that engineering students need a foundational background in one of the traditional engineering disciplines (e.g., aerospace engineering, civil engineering, electrical engineering, mechanical engineering, manufacturing engineering, industrial engineering, chemical engineering)—plus practical, real-world experience to be effective as systems engineers. Undergraduate university programs explicitly in systems engineering are growing in number but remain uncommon, the degrees including such material most often presented as a BS in Industrial Engineering. Typically programs (either by themselves or in combination with interdisciplinary study) are offered beginning at the graduate level in both academic and professional tracks, resulting in the grant of either a MS/MEng or Ph.D./EngD degree. INCOSE, in collaboration with the Systems Engineering Research Center at Stevens Institute of Technology maintains a regularly updated directory of worldwide academic programs at suitably accredited institutions. As of 2017, it lists over 140 universities in North America offering more than 400 undergraduate and graduate programs in systems engineering. Widespread institutional acknowledgment of the field as a distinct subdiscipline is quite recent; the 2009 edition of the same publication reported the number of such schools and programs at only 80 and 165, respectively. Education in systems engineering can be taken as Systems-centric or Domain-centric: Systems-centric programs treat systems engineering as a separate discipline and most of the courses are taught focusing on systems engineering principles and practice. Domain-centric programs offer systems engineering as an option that can be exercised with another major field in engineering. Both of these patterns strive to educate the systems engineer who is able to oversee interdisciplinary projects with the depth required of a core-engineer. Systems engineering topics Systems engineering tools are strategies, procedures, and techniques that aid in performing systems engineering on a project or product. The purpose of these tools vary from database management, graphical browsing, simulation, and reasoning, to document production, neutral import/export and more. System There are many definitions of what a system is in the field of systems engineering. Below are a few authoritative definitions: ANSI/EIA-632-1999: "An aggregation of end products and enabling products to achieve a given purpose." DAU Systems Engineering Fundamentals: "an integrated composite of people, products, and processes that provide a capability to satisfy a stated need or objective." IEEE Std 1220-1998: "A set or arrangement of elements and processes that are related and whose behavior satisfies customer/operational needs and provides for life cycle sustainment of the products." INCOSE Systems Engineering Handbook: "homogeneous entity that exhibits predefined behavior in the real world and is composed of heterogeneous parts that do not individually exhibit that behavior and an integrated configuration of components and/or subsystems." INCOSE: "A system is a construct or collection of different elements that together produce results not obtainable by the elements alone. The elements, or parts, can include people, hardware, software, facilities, policies, and documents; that is, all things required to produce systems-level results. The results include system level qualities, properties, characteristics, functions, behavior and performance. The value added by the system as a whole, beyond that contributed independently by the parts, is primarily created by the relationship among the parts; that is, how they are interconnected." ISO/IEC 15288:2008: "A combination of interacting elements organized to achieve one or more stated purposes." NASA Systems Engineering Handbook: "(1) The combination of elements that function together to produce the capability to meet a need. The elements include all hardware, software, equipment, facilities, personnel, processes, and procedures needed for this purpose. (2) The end product (which performs operational functions) and enabling products (which provide life-cycle support services to the operational end products) that make up a system." Systems engineering processes Systems engineering processes encompass all creative, manual and technical activities necessary to define the product and which need to be carried out to convert a system definition to a sufficiently detailed system design specification for product manufacture and deployment. Design and development of a system can be divided into four stages, each with different definitions: task definition (informative definition), conceptual stage (cardinal definition), design stage (formative definition), and implementation stage (manufacturing definition). Depending on their application, tools are used for various stages of the systems engineering process: Using models Models play important and diverse roles in systems engineering. A model can be defined in several ways, including: An abstraction of reality designed to answer specific questions about the real world An imitation, analogue, or representation of a real world process or structure; or A conceptual, mathematical, or physical tool to assist a decision maker. Together, these definitions are broad enough to encompass physical engineering models used in the verification of a system design, as well as schematic models like a functional flow block diagram and mathematical (i.e., quantitative) models used in the trade study process. This section focuses on the last. The main reason for using mathematical models and diagrams in trade studies is to provide estimates of system effectiveness, performance or technical attributes, and cost from a set of known or estimable quantities. Typically, a collection of separate models is needed to provide all of these outcome variables. The heart of any mathematical model is a set of meaningful quantitative relationships among its inputs and outputs. These relationships can be as simple as adding up constituent quantities to obtain a total, or as complex as a set of differential equations describing the trajectory of a spacecraft in a gravitational field. Ideally, the relationships express causality, not just correlation. Furthermore, key to successful systems engineering activities are also the methods with which these models are efficiently and effectively managed and used to simulate the systems. However, diverse domains often present recurring problems of modeling and simulation for systems engineering, and new advancements are aiming to crossfertilize methods among distinct scientific and engineering communities, under the title of 'Modeling & Simulation-based Systems Engineering'. Modeling formalisms and graphical representations Initially, when the primary purpose of a systems engineer is to comprehend a complex problem, graphic representations of a system are used to communicate a system's functional and
television host 1959 – Kevin Harrington, Australian actor 1959 – Armin Kogler, Austrian ski jumper 1960 – Kim Thayil, American guitarist and songwriter 1960 – Shailesh Vara, Ugandan-English lawyer and politician 1960 – Damon Wayans, American actor, director, producer, and screenwriter 1961 – Nick Blinko, English singer-songwriter and guitarist 1961 – Lars Jönsson, Swedish film producer 1962 – Kiran More, Indian cricketer 1962 – Ulla Tørnæs, Danish politician, Danish Minister of Education 1962 – Shinya Yamanaka, Japanese physician and biologist, Nobel Prize laureate 1963 – Bobby Jarzombek, American drummer 1963 – John Vanbiesbrouck, American ice hockey player, coach, and manager 1963 – Sami Yaffa, Finnish singer-songwriter and bass player 1964 – Guy Boros, American golfer 1964 – Aadesh Shrivastava, Indian singer-songwriter (d. 2015) 1965 – Sergio Momesso, Canadian ice hockey player and sportscaster 1966 – Yanka Dyagileva, Russian singer-songwriter (d. 1991) 1966 – Jeff Tremaine, American director, producer, and screenwriter 1967 – Darrin Murray, New Zealand cricketer and accountant 1967 – Dezső Szabó, Hungarian decathlete 1968 – John DiMaggio, American voice actor 1968 – Mike Piazza, American baseball player 1969 – Sasha, Welsh DJ and producer 1969 – Ramon Dekkers, Dutch kick-boxer and mixed martial artist (d. 2013) 1969 – Giorgi Margvelashvili, Georgian academic and politician, 4th President of Georgia 1969 – Inga Tuigamala, Samoan-New Zealand rugby player 1970 – Igor Cavalera, Brazilian drummer 1970 – Deni Hines, Australian singer-songwriter 1970 – Ivan Iusco, Italian composer 1970 – Sven Meyer, German footballer 1971 – Lance Klusener, South African cricketer and coach 1971 – Ione Skye, English-American actress 1971 – Maik Taylor, German-Irish footballer and coach 1972 – Steve Leonard, Northern Irish veterinarian and television personality 1973 – Aaron Fultz, American baseball player and coach 1973 – Lazlow Jones, American radio presenter, producer and screenwriter 1974 – Mati Pari, Estonian footballer and coach 1974 – Lincoln Roberts, Tobagonian cricketer 1975 – Sergio Ballesteros, Spanish footballer 1975 – Mark Ronson, English DJ, producer, and songwriter, co-founded Allido Records 1975 – Dave Salmoni, Canadian zoologist, television host, and producer 1976 – Denilson Martins Nascimento, Brazilian footballer 1976 – Mario-Ernesto Rodríguez, Uruguayan-Italian footballer 1977 – Sun-woo Kim, South Korean baseball player 1977 – Lucie Silvas, English singer-songwriter and pianist 1977 – Kia Stevens, American wrestler 1978 – Wes Bentley, American actor and producer 1978 – Terence Newman, American football player 1978 – Frederik Veuchelen, Belgian cyclist 1978 – Christian Walz, Swedish singer-songwriter and producer 1979 – Maxim Afinogenov, Russian ice hockey player 1979 – Pedro Macedo Camacho, Portuguese pianist, composer, and producer 1979 – Kosuke Matsuura, Japanese race car driver 1980 – Max Greenfield, American actor 1980 – Pat Neshek, American baseball player 1981 – Beyoncé, American singer-songwriter, producer, dancer, and actress 1981 – Richard Garcia, Australian footballer 1981 – Lacey Sturm, American singer-songwriter 1982 – Whitney Cummings, American comedian, actress, producer, and screenwriter 1982 – Mark Lewis-Francis, English sprinter 1983 – Yuichi Nakamaru, Japanese singer-songwriter, actor, and radio host 1983 – Guy Pnini, Israeli basketball player 1983 – Margit Rüütel, Estonian tennis player 1983 – Armands Šķēle, Latvian basketball player 1984 – Jonathan Adam, Scottish race car driver 1984 – Hamish McIntosh, Australian footballer 1984 – Kyle Mooney, American comedian, actor, and screenwriter 1985 – Raúl Albiol, Spanish footballer 1985 – Ri Kwang-chon, North Korean footballer 1985 – Walid Mesloub, Algerian footballer 1986 – Ayumi Kaihori, Japanese footballer 1986 – Xavier Woods, American wrestler 1987 – Wesley Blake, American wrestler 1988 – John Tyler Hammons, American politician 1989 – Elliott Whitehead, English rugby league player 1990 – James Bay, English singer-songwriter and guitarist 1990 – Jonny Lomax, English rugby player 1990 – Danny Worsnop, English singer-songwriter 1991 – Adrien Bart, French sprint canoeist 1991 – Anders Zachariassen, Danish handball player 1992 – Hanna Schwamborn, German actress 1992 – Kevin Lee, American mixed martial artist 1992 – Zerkaa, English YouTuber 1993 – Emma Brownlie, Scottish footballer 1993 – Yannick Carrasco, Belgian footballer 1993 – Jody Fannin, English race car driver 1993 – Chantal Škamlová, Slovak tennis player 1994 – Kenny McEvoy, Irish footballer 1994 – Sabina Sharipova, Uzbekistan tennis player 1994 – Thomas Minns, English rugby player 1995 – Jazz Tevaga, New Zealand rugby league player 1996 – Jordan Lilley, English rugby league player 1996 – Ashton Golding, English rugby league player 1998 – Neru Nagahama, Japanese tarento Deaths Pre-1600 422 – Boniface I, pope of the Catholic Church 799 – Musa al-Kadhim, Arabic imam (b. 745) 1037 – Bermudo III, king of León (b. c. 1017) 1063 – Tughril, Seljuq sultan (b. 990) 1199 – Joan of England, queen of Sicily (b. 1165) 1308 – Margaret of Burgundy, queen of Sicily (b. 1250) 1323 – Gegeen Khan, Chinese emperor (b. 1302) 1342 – Anna Anachoutlou, empress of Trebizond 1417 – Robert Hallam, English Catholic bishop 1537 – Johann Dietenberger, German theologian and translator (b. 1475) 1571 – Matthew Stewart, 4th Earl of Lennox, English nobleman (b. 1516) 1588 – Robert Dudley, 1st Earl of Leicester, English academic and politician, Lord Lieutenant of Norfolk (b. 1532) 1601–1900 1625 – Thomas Smythe, English diplomat (b. 1558) 1676 – John Ogilby, Scottish-born impresario and cartographer (b. 1600) 1767 – Charles Townshend, English politician, Chancellor of the Exchequer (b. 1725) 1780 – John Fielding, English lawyer and judge (b. 1721) 1784 – César-François Cassini de Thury, French astronomer and cartographer (b. 1714) 1794 – John Hely-Hutchinson, Anglo-Irish lawyer and politician (b. 1724) 1804 – Richard Somers, American lieutenant (b. 1778) 1820 – Timothy Brown, English banker and merchant (b. 1743/4) 1821 – José Miguel Carrera, Chilean general and politician (b. 1785) 1849 – Friedrich Laun, German author (b. 1770) 1852 – William MacGillivray, Scottish biologist and ornithologist (b. 1796) 1864 – John Hunt Morgan, American general (b. 1825) 1901–present 1907 – Edvard Grieg, Norwegian pianist and composer (b. 1843) 1909 – Clyde Fitch, American playwright and songwriter (b. 1865) 1911 – John Francon Williams, Welsh-born writer, journalist, geographer, historian, cartographer and inventor (b. 1854) 1914 – Charles Péguy, French poet and philosopher (b. 1873) 1923 – Howdy Wilcox, American racing driver (b. 1889) 1940 – George William de Carteret, French-English journalist and author (b. 1869) 1944 – Erich Fellgiebel, German general (b. 1886) 1963 – Robert Schuman, Luxembourgian-French politician, 130th Prime Minister of France (b. 1886) 1965 – Albert Schweitzer, French-Gabonese physician, theologian, and missionary, Nobel Prize laureate (b. 1875)	– Three terrorists suspected to be a part of Al-Qaeda are arrested in Germany after allegedly planning attacks on both the Frankfurt International airport and US military installations. 2010 – A 7.1 magnitude earthquake strikes the South Island of New Zealand causing widespread damage and several power outages. 2020 – Pope Benedict XVI becomes the longest-lived pope, 93 years, four months, 16 days, surpassing Pope Leo XIII, who died in 1903. Births Pre-1600 973 – Al-Biruni, Persian physician and polymath (d. 1048) 1241 – Alexander III, king of Scotland (d. 1286) 1383 – Felix V, antipope of Rome (d. 1451) 1454 – Henry Stafford, 2nd Duke of Buckingham, English politician, Lord High Constable of England (d. 1483) 1557 – Sophie of Mecklenburg-Güstrow, queen consort of Denmark and Norway (d. 1631) 1563 – Wanli, Chinese emperor (d. 1620) 1580 – George Percy, English explorer (d. 1632) 1596 – Constantijn Huygens, Dutch poet and composer (d. 1687) 1601–1900 1681 – Carl Heinrich Biber, Austrian violinist and composer (d. 1749) 1717 – Job Orton, English minister and author (d. 1783) 1745 – Shneur Zalman, Russian rabbi, author and founder of Chabad (d. 1812) 1755 – Axel von Fersen the Younger, Swedish general and politician (d. 1810) 1768 – François-René de Chateaubriand, French historian and politician, Minister of Foreign Affairs for France (d. 1848) 1776 – Stephen Whitney, American businessman (d. 1860) 1798 – Raynold Kaufgetz, Swiss soldier, economist, and politician (d. 1869) 1803 – Sarah Childress Polk, First Lady of the United States (d. 1891) 1809 – Manuel Montt, Chilean scholar and politician, 6th President of Chile (d. 1880) 1809 – Juliusz Słowacki, Polish poet and playwright (d. 1849) 1824 – Anton Bruckner, Austrian organist and composer (d. 1896) 1825 – Dadabhai Naoroji, Indian academic and politician, President of the Indian National Congress (d. 1917) 1826 – Martin Wiberg, Swedish philosopher and engineer (d. 1905) 1832 – Antonio Agliardi, Italian cardinal (d. 1915) 1846 – Daniel Burnham, American architect, designed the World's Columbian Exposition (d. 1912) 1848 – Lewis Howard Latimer, American inventor (d. 1928) 1848 – Jennie Lee, American actress (d. 1925) 1850 – Luigi Cadorna, Italian field marshal (d. 1928) 1851 – John Dillon, Irish poet and politician (d. 1927) 1862 – Franjo Krežma, Croatian violinist and composer (d. 1881) 1885 – Antonio Bacci, Italian cardinal (d. 1971) 1886 – Albert Orsborn, English 6th General of The Salvation Army (d. 1967) 1887 – Roy William Neill, Irish-English director, producer, and screenwriter (d. 1946) 1888 – Oskar Schlemmer, German painter, sculptor, designer and choreographer (d. 1943) 1890 – Gunnar Sommerfeldt, Danish actor, director, and screenwriter (d. 1947) 1891 – Fritz Todt, German engineer and politician (d. 1942) 1892 – Darius Milhaud, French composer and educator (d. 1974) 1896 – Antonin Artaud, French actor, director, and playwright (d. 1948) 1901–present 1901 – William Lyons, English businessman, co-founded Jaguar Cars (d. 1985) 1902 – Tommy Mitchell, English cricketer (d. 1996) 1905 – Mary Renault, English-South African author (d. 1983) 1905 – Walter Zapp, Latvian-Estonian inventor, invented the Minox (d. 2003) 1906 – Ruben Oskar Auervaara, Finnish fraudster (d. 1964) 1906 – Max Delbrück, German-American biophysicist and academic, Nobel Prize laureate (d. 1981) 1907 – Reggie Nalder, Austrian-American actor (d. 1991) 1908 – Edward Dmytryk, Canadian-American director and producer (d. 1999) 1908 – Richard Wright, American novelist, short story writer, essayist, and poet (d. 1960) 1909 – Eduard Wirths, German physician (d. 1945) 1910 – Denis Tomlinson, Zimbabwean-South African cricketer (d. 1993) 1912 – Syd Hoff, American author and illustrator (d. 2004) 1912 – Alexander Liberman, Russian-American publisher, painter, photographer, and sculptor (d. 1999) 1913 – Mickey Cohen, American mob boss (d. 1976) 1913 – Victor Kiernan, English historian and academic (d. 2009) 1913 – Stanford Moore, American biochemist and academic, Nobel Prize laureate (d. 1982) 1913 – Kenzō Tange, Japanese architect, designed the Yoyogi National Gymnasium (d. 2005) 1913 – Shmuel Wosner, Austrian-Israeli rabbi and author (d. 2015) 1914 – Rudolf Leiding, German businessman (d. 2003) 1917 – Henry Ford II, American businessman (d. 1987) 1918 – Paul Harvey, American radio host (d. 2009) 1918 – Gerald Wilson, American trumpet player and composer (d. 2014) 1919 – Howard Morris, American actor, director, and screenwriter (d. 2005) 1920 – Clemar Bucci, Argentinian race car driver (d. 2011) 1920 – Craig Claiborne, American journalist, author, and critic (d. 2000) 1920 – Konstantin Kalser, German-American film producer and advertising executive (d. 1994) 1922 – Per Olof Sundman, Swedish author and politician (d. 1992) 1923 – Ram Kishore Shukla, Indian lawyer and politician (d. 2003) 1924 – Joan Aiken, English author (d. 2004) 1924 – Justinas Lagunavičius, Lithuanian basketball player (d. 1997) 1925 – Asa Earl Carter, American Ku Klux Klan leader and author (d. 1979) 1926 – George William Gray, British chemist who developed liquid crystals that made displays possible (d. 2013) 1926 – Ivan Illich, Austrian priest and philosopher (d. 2002) 1926 – Bert Olmstead, Canadian ice hockey player and coach (d. 2015) 1927 – John McCarthy, American computer scientist and academic (d. 2011) 1927 – Ferenc Sánta, Hungarian author and screenwriter (d. 2008) 1928 – Dick York, American actor (d. 1992) 1929 – Thomas Eagleton, American lawyer and politician, 38th Lieutenant Governor of Missouri (d. 2007) 1929 – Robert V. Keeley, Lebanese-American soldier and diplomat, United States Ambassador to Greece (d. 2015) 1930 – Robert Arneson, American sculptor and academic (d. 1992) 1930 – William Maxson, American general (d. 2013) 1931 – Mitzi Gaynor, American actress, singer, and dancer 1931 – Antonios Trakatellis, Greek biochemist and politician 1932 – Carlos Romero Barceló, Puerto Rican lawyer and politician, 5th Governor of Puerto Rico (d. 2021) 1932 – Vince Dooley, American football player and coach 1934 – Clive Granger, Welsh-American economist and academic, Nobel Prize laureate (d. 2009) 1934 – Antoine Redin, French footballer and manager (d. 2012) 1934 – Eduard Khil, Russian baritone singer (d. 2012) 1934 – Jan Švankmajer, Czech filmmaker and artist 1935 – Charles A. Hines, American general and academic (d. 2013) 1935 – Dallas Willard, American philosopher and academic (d. 2013) 1937 – Dawn Fraser, Australian swimmer and politician 1937 – Gene Ludwig, American organist and composer (d. 2010) 1937 – Virgil A. Richard, American general (d. 2013) 1937 – Les Allen, English footballer and manager 1939 – Denis Lindsay, South African cricketer and referee (d. 2005) 1941 – Marilena de Souza Chaui, Brazilian philosopher and academic 1941 – Ken Harrelson, American baseball player and sportscaster 1941 – Ramesh Sethi, Kenyan cricketer and coach 1941 – Sushilkumar Shinde, Indian lawyer and politician, 19th Governor of Andhra Pradesh 1942 – Raymond Floyd, American golfer 1942 – Jerry Jarrett, American wrestler and promoter, co-founded Total Nonstop Action Wrestling 1942 – Merald "Bubba" Knight, American singer 1944 – Tony Atkinson, English economist and academic (d. 2017) 1944 – Dave Bassett, English footballer and manager 1944 – Gene Parsons, American singer-songwriter, drummer, guitarist, and banjo player 1944 – Jerry Relph, American politician and member of the Minnesota Senate (d. 2020) 1945 – Danny Gatton, American guitarist (d. 1994) 1945 – Bill Kenwright, English actor, singer, and producer 1946 – Gary Duncan, American guitarist (d. 2019) 1946 – Dave Liebman, American saxophonist, flute player, and composer 1946 – Bryan Mauricette, Saint Lucian-Canadian cricketer 1947 – Bob Jenkins, American sportscaster (d. 2021) 1947 – Paul Sait, Australian rugby league player 1949 – Darryl Cotton, Australian singer-songwriter and guitarist (d. 2012) 1949 – Dean Pees, American football player and coach 1949 – Tom Watson, American golfer and sportscaster 1950 – Doyle Alexander, American baseball player 1951 – Martin Chambers, English drummer and singer 1951 – Judith Ivey, American actress 1951 – Marita Ulvskog, Swedish politician, Deputy Prime Minister of Sweden 1952 – Stephen Easley, American businessman and politician (d. 2013) 1953 – Janet Biehl, American philosopher and author 1953 – Michael Stean, English chess player and author 1953 – Fatih Terim, Turkish footballer and manager 1955 – David Broza, Israeli singer-songwriter and guitarist 1955 – Garth Le Roux, South African cricketer 1955 – Brian Schweitzer, American politician, 23rd Governor of Montana 1956 – Blackie Lawless, American singer-songwriter and guitarist 1957 – Khandi Alexander, American actress, dancer, and choreographer 1958 – Jacqueline Hewitt, American astrophysicist and astronomer 1958 – Marzio Innocenti, Italian rugby player and coach 1958 – Drew Pinsky, American radio and television host 1959 – Kevin Harrington, Australian actor 1959 – Armin Kogler, Austrian ski jumper 1960 – Kim Thayil, American guitarist and songwriter 1960 – Shailesh Vara, Ugandan-English lawyer and politician 1960 – Damon Wayans, American actor, director, producer, and screenwriter 1961 – Nick Blinko, English singer-songwriter and guitarist 1961 – Lars Jönsson, Swedish film producer 1962 – Kiran More, Indian cricketer 1962 – Ulla Tørnæs, Danish politician, Danish Minister of Education 1962 – Shinya Yamanaka, Japanese physician and biologist, Nobel Prize laureate 1963 – Bobby Jarzombek, American drummer 1963 – John Vanbiesbrouck, American ice hockey player, coach, and manager 1963 – Sami Yaffa, Finnish singer-songwriter and bass player 1964 – Guy Boros, American golfer 1964 – Aadesh Shrivastava, Indian singer-songwriter (d. 2015) 1965 – Sergio Momesso, Canadian ice hockey player and sportscaster 1966 – Yanka Dyagileva, Russian singer-songwriter (d. 1991) 1966 – Jeff Tremaine, American director, producer, and screenwriter 1967 – Darrin Murray, New Zealand cricketer and accountant 1967 – Dezső Szabó, Hungarian decathlete 1968 – John DiMaggio, American voice actor 1968 – Mike Piazza, American baseball player 1969 – Sasha, Welsh DJ and producer 1969 – Ramon Dekkers, Dutch kick-boxer and mixed martial artist (d. 2013) 1969 – Giorgi Margvelashvili, Georgian academic and politician, 4th President of Georgia 1969 – Inga Tuigamala, Samoan-New Zealand rugby player 1970 – Igor Cavalera, Brazilian drummer 1970 – Deni Hines, Australian singer-songwriter 1970 – Ivan Iusco, Italian composer 1970
Comics and Epic Comics. "Fair Wind to Java" was originally published in 1988 as a Munden's Bar story in the pages of First Comics' Grimjack, featuring the Freelance Police fighting pyramid-building aliens in Ancient Egypt, and was followed in 1989 by "On the Road", a three chapter story showing what Sam and Max do on vacation. In 1990, Christmas-themed story "The Damned Don't Dance" was released. 1992 saw the release of two further comics: "Bad Day On The Moon" took the Freelance Police to deal with a roach infestation bothering giant rats on the Moon, and was later adapted as a story for the animated TV series, whilst "Beast From The Cereal Aisle" focused on the duo conducting an exorcism at the local supermarket. Two more comics were produced in 1997, "The Kids Take Over" and "Belly Of The Beast". The former has Sam and Max wake up from cryogenic sleep to discover that the entire world is now ruled by children while the latter sees the Freelance Police confronting a vampire abducting children at Halloween. Purcell joined LucasArts in 1988 as an artist and game designer, where he was approached about contributing to LucasArts' new quarterly newsletter, The Adventurer, a publication designed to inform customers about upcoming LucasArts games and company news. From its debut issue in 1990 to 1996, Purcell created twelve comic strips for the newsletter. The strips portrayed a variety of stories, from similar plots as in the comic books to parodies of LucasArts games such as Monkey Island and Full Throttle and the Lucasfilm franchises Star Wars and Indiana Jones. In 1995, all of the comics and The Adventurer strips published to that date were released in a compilation, Sam & Max: Surfin' the Highway. Published by Marlowe & Company, the 154 page book was updated and republished in 1996. This original version of Surfin' the Highway went out of print in 1997, becoming a high priced collectors item sold through services such as eBay. In 2007, a 197-page twenty-year anniversary edition, containing all printed comics and strips as well as a variety of other artwork, was co-designed by Steve Purcell and Jake Rodkin and published by Telltale Games. This second publication received an Eisner Award nomination for "Best Graphic Album – Reprint" in 2009. In December 2005, Purcell started a Sam & Max webcomic, hosted on the website of Telltale Games. Entitled "The Big Sleep", the webcomic began with Sam and Max bursting out of their graves at Kilpeck Church in England, symbolizing the Freelance Police's return after nearly a decade. In the twelve page story, Max has to save Sam after earwigs start a colony in Sam's brain. The webcomic concluded in April 2007, and was later awarded the Eisner Award for "Best Digital Comic" of 2007. Video games Following LucasArts' employment of Purcell in 1988, the characters of Sam and Max appeared in internal testing material for new SCUMM engine programmers; Purcell created animated versions of the characters and an office backdrop for the programmers to practice on. In 1992, LucasArts offered Purcell the chance to create a video game out of the characters, out of a wish to use new characters after the success of its two other main adventure titles, Monkey Island and Maniac Mansion, and after a positive reaction from fans to the Sam & Max comic strips featured in LucasArts' The Adventurer newsletter. Consequently, development on a graphic adventure game, Sam & Max Hit the Road, began shortly after. Based on the SCUMM engine and designed by Sean Clark, Michael Stemmle, Steve Purcell and his future wife Collette Michaud, the game was partially based on the 1989 comic "On The Road", and featured the Freelance Police travelling across America in search of an escaped bigfoot. Sam was voiced in the game by comedian Bill Farmer, while actor Nick Jameson voiced Max. Sam & Max Hit the Road was originally released for DOS in November 1993. Soon after Sam & Max Hit the Road, another Sam & Max game using SCUMM entered planning under Purcell and Dave Grossman, but was abandoned. In a later interview Grossman described this sequel's highlight as "a giant spaceship shaped like Max's head". In September 2001 development began on a new project, Sam & Max Plunge Through Space. The game was to be an Xbox exclusive title, developed by Infinite Machine, a small company consisting of a number of former LucasArts employees. The story of the game was developed by Purcell and fellow designer Chuck Jordan and involved the Freelance Police travelling the galaxy to find a stolen Statue of Liberty. However, Infinite Machine went bankrupt within a year, partially due to the failure of their first game, New Legends, and the project was abandoned. At the 2002 Electronic Entertainment Expo convention, nearly a decade after the release of Sam & Max Hit the Road, LucasArts announced the production of a PC sequel, entitled Sam & Max: Freelance Police. Freelance Police, like Hit the Road, was to be a point-and-click graphic adventure game, using a new 3D game engine. Development of Freelance Police was led by Michael Stemmle. Steve Purcell contributed to the project by writing the story and producing concept art. Farmer and Jameson were also set to reprise their voice acting roles. In March 2004, however, quite far into the game's development, Sam & Max: Freelance Police was abruptly cancelled by LucasArts, citing "current market place realities and underlying economic considerations" in a short press release. The fan reaction to the cancellation was strong; a petition of 32,000 signatures stating the disappointment of fans was later presented to LucasArts. After LucasArts' license with Steve Purcell expired in 2005, the Sam & Max franchise moved to Telltale Games, a company of former LucasArts employees who had worked on a number of LucasArts adventure games, including on the development of Freelance Police. Under Telltale Games, a new episodic series of Sam & Max video games was announced. Like both Sam & Max Hit the Road and Freelance Police, Sam & Max Save the World was in a point-and-click graphic adventure game format. The game used a new 3D game engine, different from the one used in Freelance Police. The first season ran for six episodes, each with a self-contained storyline but with an overall story arc involving hypnotism running through the series. The first episode was released on GameTap in October 2006, with episodes following regularly until April 2007. Sam is voiced by David Nowlin, while Max is voiced by William Kasten in all episodes except the first one, where Andrew Chaikin voices the character. In addition, Telltale Games produced fifteen machinima shorts to accompany the main episodes. These shorts were released in groups of three in between the release of each episode, showing the activities of the Freelance Police in between each story. A second season of episodic video games developed by Telltale Games was announced in July 2007. Sam & Max Beyond Time and Space followed the same overall format as Save the World, with each episode having an overarching storyline involving time travel and laundering of the souls of the dead. As with Save the World, episodes were originally published on GameTap before being made available for general release. The season consisted of five episodes and ran from November 2007 to April 2008. Nowlin and Kasten both returned to reprise their voice roles. In addition to the main games, a twenty-minute machinima video was produced, taking the form of a Sam & Max Christmas special. A third game entitled Sam & Max: The Devil's Playhouse was confirmed in May 2008 for release in 2009; the title was later pushed back to 2010, with concept art emerging after Telltale's completion of Tales of Monkey Island. The season again ran for five episodes, released monthly from April to August 2010. The Devil's Playhouse followed a structure similar to Tales of Monkey Island, with each episode forming a part of an ongoing narrative, involving psychic powers and forces that used them for world domination. A two-minute Flash cartoon also accompanied the game, dealing with the origin story of General Skun-ka'pe, one of the game's antagonists. Max also appears in Telltale's 2010 casual game Poker Night at the Inventory alongside Tycho Brahe from Penny Arcade, the Heavy from Team Fortress 2 and Strong Bad from Homestar Runner. Sam and Max (now voiced by Dave Boat) also appear in the game's sequel alongside Claptrap from Borderlands, Brock Samson from The Venture Bros., Ash Williams from Evil Dead and GLaDOS from Portal. A Sam & Max virtual reality game, Sam & Max: This Time It's Virtual, was announced in August 2020 from HappyGiant. Purcell served as a consultant for game design, Stemmle returned as designer and writer, Jared Emerson-Johnson returned as composer, and Nowlin and Boat returned to voice Sam and Max, respectively. The game was released on July 8, 2021 for Oculus Quest, with releases for SteamVR and Viveport Infinity to follow in late 2021, and for PlayStation VR in 2022. Remastered releases of the three Telltale seasons are currently in development, beginning with Save the World Remastered in December 2020. The remasters are developed by Skunkape Games, a studio made up of former members of the original development team and named in reference to the General Skun-ka'pe character from The Devil's Playhouse. Television series Sam & Max were adapted into a cartoon series for Fox in 1997. Produced by Canadian studio Nelvana, the series ran for 24 episodes. Each episode was approximately ten minutes, and were often aired in pairs, with the exception of the first and last episodes, which were 20 minutes long. Broadcast on Fox Kids in the United States, YTV in Canada, and Channel 4 in the United Kingdom, the first episode was aired on October 4, 1997; the series concluded on April 25, 1998. As opposed to the more adult humor in the rest of the series, The Adventures of Sam & Max: Freelance Police was aimed more at children, even though some humor in it was often directed at adults. As such, the violence inherent in the franchise is toned down, including removing Sam and Max's guns, and the characters do not use the moderate profanity that they use in their other appearances. As in most Sam & Max stories, the series revolves around the Freelance Police accepting missions from their mysterious superior, the commissioner, and embarking on cases to a large variety of implausible locations. Sam is voiced by Harvey Atkin, while Max is voiced by Robert Tinkler. The series performed well and was considered a success, and in 1998 received the Gemini Award for "Best Animated Program or Series". Despite the series' success, a second season was never commissioned. In June 2007, it was reported that Shout! Factory were preparing a DVD release of the series. In October 2007, as part of their marketing for Sam & Max Save the World, GameTap hosted the series on their website. The DVD release of the series was later published in March 2008. Music The Sam & Max franchise features a variety of soundtracks that accompany its video game products. This music is mostly grounded in film noir jazz, incorporating various other styles at certain points, such as Dixieland, waltz and mariachi, usually to support the cartoon nature of the series. The first Sam & Max game, Sam & Max Hit the Road, was one of the first games to feature a fully scored music soundtrack, written by LucasArts' composers Clint Bajakian, Michael Land and Peter McConnell. The music was incorporated into the game using Land and McConnell's iMUSE engine, which allowed for audio to be synchronized with the visuals. Although the full soundtrack was never released, audio renders of four of the game's MIDI tracks were included on the CD version of the game. For Sam & Max Save the World, Beyond Time and Space, and The Devil's Playhouse, Telltale Games contracted composer Jared Emerson-Johnson, a musician whose previous work included composition and sound editing for LucasArts, to write the scores. The soundtracks for the first two games were released in two disc sets after the release of the games themselves; the Season One Soundtrack was published in July 2007, whilst the Season Two Soundtrack was released in September 2008. Emerson-Johnson's scores use live performances as opposed to synthesized music often used elsewhere in the video game industry. Critics reacted positively to Emerson-Johnson's scores, IGN described Emerson-Johnson's work as a "breath of fresh air", while 1UP.com praised his work as "top-caliber" and Music4Games stated that	seeing the world as little more than a vessel for his "pinball-like stream of consciousness". This creates a seeming disregard for self-preservation; Max will revel in dangerous situations with little impression that he understands the risks he faces. As a result, Max is usually enthusiastic to engage in any activity, including being used by Sam as a cable cutter or an impromptu bludgeon. Despite this, Max possesses a sharp mind and an observational nature, and enjoys interpreting new experiences in as unpredictable a manner as possible. However, Max has a distaste for long stories and occasionally loses focus during lengthy scenes of plot exposition; by his own admission, Max possesses a particularly short attention span. Despite his seemingly heartless personality, he believes strongly in protecting Sam. However, Max can still act violently towards his friend, stating that when he dies he will take Sam with him. Moreover, Max is extremely possessive of Sam and their status as partners and best friends. Max traditionally carries a Luger pistol, but as he wears no clothes, other characters often make comments as to where Max keeps it on his person. Purcell considers Max to be representative of pure id, the uncoordinated instinctual trends of the human psyche. Max's voice is provided by Nick Jameson in Sam & Max Hit the Road and by Rob Tinkler in the animated series. Andrew Chaikin originally voiced Max in the first episode of Telltale's games before being replaced by William Kasten, while Dave Boat voices the character from Poker Night 2 onward. Media Comic books Sam and Max debuted in the 1987 comic book series Sam & Max: Freelance Police, published by Fishwrap Productions, also the publisher of Fish Police. The first comic, "Monkeys Violating the Heavenly Temple", was Steve Purcell's first full story. The comic came about after Purcell agreed to create a full Sam & Max story for publication alongside Steve Moncuse's Fish Police series. "Monkeys Violating the Heavenly Temple" established many of the key features in the series; the main story of the comic saw the Freelance Police journey to the Philippines to stop a volcano god cult. "Night of the Gilded Heron-Shark" and "Night of the Cringing Wildebeest" accompanied the main story, focusing on a stand-off with a group of gangsters in Sam and Max's office and an investigation into a carnival refreshment booth respectively. Over the subsequent years, several other comics were published, often by different publishers, including Comico Comics and Epic Comics. "Fair Wind to Java" was originally published in 1988 as a Munden's Bar story in the pages of First Comics' Grimjack, featuring the Freelance Police fighting pyramid-building aliens in Ancient Egypt, and was followed in 1989 by "On the Road", a three chapter story showing what Sam and Max do on vacation. In 1990, Christmas-themed story "The Damned Don't Dance" was released. 1992 saw the release of two further comics: "Bad Day On The Moon" took the Freelance Police to deal with a roach infestation bothering giant rats on the Moon, and was later adapted as a story for the animated TV series, whilst "Beast From The Cereal Aisle" focused on the duo conducting an exorcism at the local supermarket. Two more comics were produced in 1997, "The Kids Take Over" and "Belly Of The Beast". The former has Sam and Max wake up from cryogenic sleep to discover that the entire world is now ruled by children while the latter sees the Freelance Police confronting a vampire abducting children at Halloween. Purcell joined LucasArts in 1988 as an artist and game designer, where he was approached about contributing to LucasArts' new quarterly newsletter, The Adventurer, a publication designed to inform customers about upcoming LucasArts games and company news. From its debut issue in 1990 to 1996, Purcell created twelve comic strips for the newsletter. The strips portrayed a variety of stories, from similar plots as in the comic books to parodies of LucasArts games such as Monkey Island and Full Throttle and the Lucasfilm franchises Star Wars and Indiana Jones. In 1995, all of the comics and The Adventurer strips published to that date were released in a compilation, Sam & Max: Surfin' the Highway. Published by Marlowe & Company, the 154 page book was updated and republished in 1996. This original version of Surfin' the Highway went out of print in 1997, becoming a high priced collectors item sold through services such as eBay. In 2007, a 197-page twenty-year anniversary edition, containing all printed comics and strips as well as a variety of other artwork, was co-designed by Steve Purcell and Jake Rodkin and published by Telltale Games. This second publication received an Eisner Award nomination for "Best Graphic Album – Reprint" in 2009. In December 2005, Purcell started a Sam & Max webcomic, hosted on the website of Telltale Games. Entitled "The Big Sleep", the webcomic began with Sam and Max bursting out of their graves at Kilpeck Church in England, symbolizing the Freelance Police's return after nearly a decade. In the twelve page story, Max has to save Sam after earwigs start a colony in Sam's brain. The webcomic concluded in April 2007, and was later awarded the Eisner Award for "Best Digital Comic" of 2007. Video games Following LucasArts' employment of Purcell in 1988, the characters of Sam and Max appeared in internal testing material for new SCUMM engine programmers; Purcell created animated versions of the characters and an office backdrop for the programmers to practice on. In 1992, LucasArts offered Purcell the chance to create a video game out of the characters, out of a wish to use new characters after the success of its two other main adventure titles, Monkey Island and Maniac Mansion, and after a positive reaction from fans to the Sam & Max comic strips featured in LucasArts' The Adventurer newsletter. Consequently, development on a graphic adventure game, Sam & Max Hit the Road, began shortly after. Based on the SCUMM engine and designed by Sean Clark, Michael Stemmle, Steve Purcell and his future wife Collette Michaud, the game was partially based on the 1989 comic "On The Road", and featured the Freelance Police travelling across America in search of an escaped bigfoot. Sam was voiced in the game by comedian Bill Farmer, while actor Nick Jameson voiced Max. Sam & Max Hit the Road was originally released for DOS in November 1993. Soon after Sam & Max Hit the Road, another Sam & Max game using SCUMM entered planning under Purcell and Dave Grossman, but was abandoned. In a later interview Grossman described this sequel's highlight as "a giant spaceship shaped like Max's head". In September 2001 development began on a new project, Sam & Max Plunge Through Space. The game was to be an Xbox exclusive title, developed by Infinite Machine, a small company consisting of a number of former LucasArts employees. The story of the game was developed by Purcell and fellow designer Chuck Jordan and involved the Freelance Police travelling the galaxy to find a stolen Statue of Liberty. However, Infinite Machine went bankrupt within a year, partially due to the failure of their first game, New Legends, and the project was abandoned. At the 2002 Electronic Entertainment Expo convention, nearly a decade after the release of Sam & Max Hit the Road, LucasArts announced the production of a PC sequel, entitled Sam & Max: Freelance Police. Freelance Police, like Hit the Road, was to be a point-and-click graphic adventure game, using a new 3D game engine. Development of Freelance Police was led by Michael Stemmle. Steve Purcell contributed to the project by writing the story and producing concept art. Farmer and Jameson were also set to reprise their voice acting roles. In March 2004, however, quite far into the game's development, Sam & Max: Freelance Police was abruptly cancelled by LucasArts, citing "current market place realities and underlying economic considerations" in a short press release. The fan reaction to the cancellation was strong; a petition of 32,000 signatures stating the disappointment of fans was later presented to LucasArts. After LucasArts' license with Steve Purcell expired in 2005, the Sam & Max franchise moved to Telltale Games, a company of former LucasArts employees who had worked on a number of LucasArts adventure games, including on the development of Freelance Police. Under Telltale Games, a new episodic series of Sam & Max video games was announced. Like both Sam & Max Hit the Road and Freelance Police, Sam & Max Save the World was in a point-and-click graphic adventure game format. The game used a new 3D game engine, different from the one used in Freelance Police. The first season ran for six episodes, each with a self-contained storyline but with an overall story arc involving hypnotism running through the series. The first episode was released on GameTap in October 2006, with episodes following regularly until April 2007. Sam is voiced by David Nowlin, while Max is voiced by William Kasten in all episodes except the first one, where Andrew Chaikin voices the character. In addition, Telltale Games produced fifteen machinima shorts to accompany the main episodes. These shorts were released in groups of three in between the release of each episode, showing the activities of the Freelance Police in between each story. A second season of episodic video games developed by Telltale Games was announced in July 2007. Sam & Max Beyond Time and Space followed the same overall format as Save the World, with each episode having an overarching storyline involving time travel and laundering of the souls of the dead. As with Save the World, episodes were originally published on GameTap before being made available for general release. The season consisted of five episodes and ran from November 2007 to April 2008. Nowlin and Kasten both returned to reprise their voice roles. In addition to the main games, a twenty-minute machinima video was produced, taking the form of a Sam & Max Christmas special. A third game entitled Sam & Max: The Devil's Playhouse was confirmed in May 2008 for release in 2009; the title was later pushed back to 2010, with concept art emerging after Telltale's completion of Tales of Monkey Island. The season again ran for five episodes, released monthly from April to August 2010. The Devil's Playhouse followed a structure similar to Tales of Monkey Island, with each episode forming a part of an ongoing narrative, involving psychic powers and forces that used them for world domination. A two-minute Flash cartoon also accompanied the game, dealing with the origin story of General Skun-ka'pe, one of the game's antagonists. Max also appears in Telltale's 2010 casual game Poker Night at the Inventory alongside Tycho Brahe from Penny Arcade, the Heavy from Team Fortress 2 and Strong Bad from Homestar Runner. Sam and Max (now voiced by Dave Boat) also appear in the game's sequel alongside Claptrap from Borderlands, Brock Samson from The Venture Bros., Ash Williams from Evil Dead and GLaDOS from Portal. A Sam & Max virtual reality game, Sam & Max: This Time It's Virtual, was announced in August 2020 from HappyGiant. Purcell served as a consultant for game design, Stemmle returned as designer and writer, Jared Emerson-Johnson returned as composer, and Nowlin and Boat returned to voice Sam and Max, respectively. The game was released on July 8, 2021 for Oculus Quest, with releases for SteamVR and Viveport Infinity to follow in late 2021, and for PlayStation VR in 2022. Remastered releases of the three Telltale seasons are currently in development, beginning with Save the World Remastered in December 2020. The remasters are developed by Skunkape Games, a studio made up of former members of the original development team and named in reference to the General Skun-ka'pe character from The Devil's Playhouse. Television series Sam & Max were adapted into a cartoon series for Fox in 1997. Produced by Canadian studio Nelvana, the series ran for 24 episodes. Each episode was approximately ten minutes, and were often aired in pairs, with the exception of the first and last episodes, which were 20 minutes long. Broadcast on Fox Kids in the United States, YTV in Canada, and Channel 4 in the United Kingdom, the first episode was aired on October 4, 1997; the series concluded on April 25, 1998. As opposed to the more adult humor in the rest of the series, The Adventures of Sam & Max: Freelance Police was aimed more at children, even though some humor in it was often directed at adults. As such, the violence inherent in the franchise is toned down, including removing Sam and Max's guns, and the characters do not use the moderate profanity that they use in their other appearances. As in most Sam & Max stories, the series revolves around the Freelance Police accepting missions from their
considered to be either high or enhanced definition. "Standard" refers to it being the prevailing specification for broadcast (and later, cable) television in the mid- to late-20th century, and compatible with legacy analog broadcast systems. The two common SDTV signal types are 576i, with 576 interlaced lines of resolution, derived from the European-developed PAL and SECAM systems, and 480i based on the American NTSC system. Common SDTV refresh rates are 25, 29.97 and 30 frames per second. Both systems use a 4:3 aspect ratio. Standards that support digital SDTV broadcast include DVB, ATSC, and ISDB. The last two were originally developed for HDTV, but are also used for their ability to deliver multiple SD video and audio streams via multiplexing. In North America, digital SDTV is broadcast in the same 4:3 aspect ratio as NTSC signals, with widescreen content often being center cut. However, the aspect ratio of widescreen content may be preserved in a 4:3 frame through letterboxing. In other parts of the world that used the PAL or SECAM color systems, digital standard-definition television is now usually shown with a 16:9 aspect ratio, with the transition occurring between the mid-1990s and late-2000s depending on region. Older programs with a 4:3 aspect ratio are broadcast with a flag that switches the display to 4:3. Digital SDTV eliminates the ghosting and noisy images associated	European-developed PAL and SECAM systems, and 480i based on the American NTSC system. Common SDTV refresh rates are 25, 29.97 and 30 frames per second. Both systems use a 4:3 aspect ratio. Standards that support digital SDTV broadcast include DVB, ATSC, and ISDB. The last two were originally developed for HDTV, but are also used for their ability to deliver multiple SD video and audio streams via multiplexing. In North America, digital SDTV is broadcast in the same 4:3 aspect ratio as NTSC signals, with widescreen content often being center cut. However, the aspect ratio of widescreen content may be preserved in a 4:3 frame through letterboxing. In other parts of the world that used the PAL or SECAM color systems, digital standard-definition television is now usually shown with a 16:9 aspect ratio, with the transition occurring between the mid-1990s and late-2000s depending on region. Older programs with a 4:3 aspect ratio are broadcast with a flag that switches the display to 4:3. Digital SDTV eliminates the ghosting and noisy images associated with analog systems. However, if the reception has interference or is poor, where the error correction cannot compensate one will encounter various other artifacts such as image freezing, stuttering or dropouts from missing intra-frames or blockiness from missing macroblocks. Pixel aspect ratio The table below summarizes pixel aspect ratios for the scaling of various kinds of SDTV video lines. The pixel aspect ratio is the same for 720- and 704-pixel resolutions because the visible image (be it 4:3 or 16:9) is contained in the center 704 horizontal pixels of the digital
make up just a small percentage of the grains in a sandstone. Common accessory minerals include micas (muscovite and biotite), olivine, pyroxene, and corundum. Many of these accessory grains are more dense than the silicates that make up the bulk of the rock. These heavy minerals are commonly resistant to weathering and can be used as an indicator of sandstone maturity through the ZTR index. Common heavy minerals include zircon, tourmaline, rutile (hence ZTR), garnet, magnetite, or other dense, resistant minerals derived from the source rock. Matrix Matrix is very fine material, which is present within interstitial pore space between the framework grains. The nature of the matrix within the interstitial pore space results in a twofold classification: Arenites are texturally clean sandstones that are free of or have very little matrix. Wackes are texturally dirty sandstones that have a significant amount of matrix. Cement Cement is what binds the siliciclastic framework grains together. Cement is a secondary mineral that forms after deposition and during burial of the sandstone. These cementing materials may be either silicate minerals or non-silicate minerals, such as calcite. Silica cement can consist of either quartz or opal minerals. Quartz is the most common silicate mineral that acts as cement. In sandstone where there is silica cement present, the quartz grains are attached to cement, which creates a rim around the quartz grain called overgrowth. The overgrowth retains the same crystallographic continuity of quartz framework grain that is being cemented. Opal cement is found in sandstones that are rich in volcanogenic materials, and very rarely is in other sandstones. Calcite cement is the most common carbonate cement. Calcite cement is an assortment of smaller calcite crystals. The cement adheres to the framework grains, cementing the framework grains together. Other minerals that act as cements include: hematite, limonite, feldspars, anhydrite, gypsum, barite, clay minerals, and zeolite minerals. Sandstone that becomes depleted of its cement binder through weathering gradually becomes friable and unstable. This process can be somewhat reversed by the application of tetraethyl orthosilicate (Si(OC2H5)4) which will deposit amorphous silicon dioxide between the sand grains. The reaction is as follows. Si(OC2H5)4 (l) + 2 H2O (l) → SiO2 (s) + 4 C2H5OH (g) Pore space Pore space includes the open spaces within a rock or a soil. The pore space in a rock has a direct relationship to the porosity and permeability of the rock. The porosity and permeability are directly influenced by the way the sand grains are packed together. Porosity is the percentage of bulk volume that is inhabited by interstices within a given rock. Porosity is directly influenced by the packing of even-sized spherical grains, rearranged from loosely packed to tightest packed in sandstones. Permeability is the rate in which water or other fluids flow through the rock. For groundwater, work permeability may be measured in gallons per day through a one square foot cross section under a unit hydraulic gradient. Types of sandstone Sandstones are typically classified by point-counting a thin section using a method like the Gazzi-Dickinson Method. This yields the relative percentages of quartz, feldspar, and lithic grains and the amount of clay matrix. The composition of a sandstone can provide important information on the genesis of the sediments when used with a triangular Quartz, Feldspar, Lithic fragment (QFL diagrams). However, geologist have not been able to agree on a set of boundaries separating regions of the QFL triangle. Visual aids are diagrams that allow geologists to interpret different characteristics of a sandstone. For example, a QFL chart can be marked with a provenance model that shows the likely tectonic origin of sandstones with various compositions of framework grains. Likewise, the stage of textural maturity chart illustrates the different stages that a sandstone goes through as the degree of kinetic processing of the sediments increases. A QFL chart is a representation of the framework grains and matrix that is present in a sandstone. This chart is similar to those used in igneous petrology. When plotted correctly, this model of analysis creates for a meaningful quantitative classification of sandstones. A sandstone provenance chart is typically based on a QFL chart but allows geologists to visually interpret the different types of places from which sandstones can originate. A stage of textural maturity chart shows the differences between immature, submature, mature, and supermature sandstones. As the sandstone becomes more mature, grains become more rounded, and there is less clay in the matrix of the rock. Dott's classification scheme Dott's (1964) sandstone classification scheme is one of many such schemes used by geologists for classifying sandstones. Dott's scheme is a modification of Gilbert's classification of silicate sandstones, and it incorporates R.L. Folk's dual textural and compositional maturity concepts into one classification system. The philosophy behind combining Gilbert's and R. L. Folk's schemes is that it is better able to "portray the continuous nature of textural variation from mudstone to arenite and from stable to unstable grain composition". Dott's classification scheme is based on the mineralogy of framework grains, and on the type of matrix present in between the framework grains. In this specific classification scheme, Dott has set the boundary between arenite and wackes at 15% matrix. In addition, Dott also breaks up the different types of framework grains that can be present in a sandstone into three major categories: quartz, feldspar, and lithic grains. Arenites are types of sandstone that have less than 15% clay matrix in between the framework grains. Quartz arenites are sandstones that contain more than 90% of siliceous grains. Grains can include quartz or chert rock fragments. Quartz arenites are texturally mature to supermature sandstones. These pure quartz sands result from extensive weathering that occurred before and during transport. This weathering removed everything but quartz grains, the most stable mineral. They are commonly affiliated with rocks that are deposited in a stable cratonic environment, such as aeolian beaches or shelf environments. Quartz arenites emanate from multiple recycling of quartz grains, generally	continental margins are also common environments for deposition of sand. As sediments continue to accumulate in the depositional environment, older sand is buried by younger sediments, and it undergoes diagenesis. This mostly consists of compaction and lithification of the sand. Early stages of diagenesis, described as eogenesis, take place at shallow depths (a few tens of meters) and are characterized by bioturbation and mineralogical changes in the sands, with only slight compaction. The red hematite that gives red bed sandstones their color is likely formed during eogenesis. Deeper burial is accompanied by mesogenesis, during which most of the compaction and lithification takes place. Compaction takes place as the sand comes under increasing pressure from overlying sediments. Sediment grains move into more compact arrangements, ductile grains (such as mica grains) are deformed, and pore space is reduced. In addition to this physical compaction, chemical compaction may take place via pressure solution. Points of contact between grains are under the greatest strain, and the strained mineral is more soluble than the rest of the grain. As a result, the contact points are dissolved away, allowing the grains to come into closer contact. Lithification follows closely on compaction, as increased temperatures at depth hasten deposition of cement that binds the grains together. Pressure solution contributes to cementing, as the mineral dissolved from strained contact points is redeposited in the unstrained pore spaces. Mechanical compaction takes place primarily at depths less than . Chemical compaction continues to depths of , and most cementation takes place at depths of . Unroofing of buried sandstone is accompanied by telogenesis, the third and final stage of diagenesis. As erosion reduces the depth of burial, renewed exposure to meteoric water produces additional changes to the sandstone, such as dissolution of some of the cement to produce secondary porosity. Components Framework grains Framework grains are sand-sized ( diameter) detrital fragments that make up the bulk of a sandstone. Most framework grains are composed of quartz or feldspar, which are the common minerals most resistant minerals to weathering processes at the Earth's surface, as seen in the Goldich dissolution series. Framework grains can be classified into several different categories based on their mineral composition: Quartz framework grains are the dominant minerals in most clastic sedimentary rocks; this is because they have exceptional physical properties, such as hardness and chemical stability. These physical properties allow the quartz grains to survive multiple recycling events, while also allowing the grains to display some degree of rounding. Quartz grains evolve from plutonic rock, which are felsic in origin and also from older sandstones that have been recycled. Feldspathic framework grains are commonly the second most abundant mineral in sandstones. Feldspar can be divided into alkali feldspars and plagioclase feldspars, which can be distinguished under a petrographic microscope. Alkali feldspar range in chemical composition from KAlSi3O8 to NaAlSi3O8. Plagioclase feldspar range in composition from NaAlSi3O8 to CaAl2Si2O8. Lithic framework grains (also called lithic fragments or lithic clasts) are pieces of ancient source rock that have yet to weather away to individual mineral grains. Lithic fragments can be any fine-grained or coarse-grained igneous, metamorphic, or sedimentary rock, although the most common lithic fragments found in sedimentary rocks are clasts of volcanic rocks. Accessory minerals are all other mineral grains in a sandstone. These minerals usually make up just a small percentage of the grains in a sandstone. Common accessory minerals include micas (muscovite and biotite), olivine, pyroxene, and corundum. Many of these accessory grains are more dense than the silicates that make up the bulk of the rock. These heavy minerals are commonly resistant to weathering and can be used as an indicator of sandstone maturity through the ZTR index. Common heavy minerals include zircon, tourmaline, rutile (hence ZTR), garnet, magnetite, or other dense, resistant minerals derived from the source rock. Matrix Matrix is very fine material, which is present within interstitial pore space between the framework grains. The nature of the matrix within the interstitial pore space results in a twofold classification: Arenites are texturally clean sandstones that are free of or have very little matrix. Wackes are texturally dirty sandstones that have a significant amount of matrix. Cement Cement is what binds the siliciclastic framework grains together. Cement is a secondary mineral that forms after deposition and during burial of the sandstone. These cementing materials may be either silicate minerals or non-silicate minerals, such as calcite. Silica cement can consist of either quartz or opal minerals. Quartz is the most common silicate mineral that acts as cement. In sandstone where there is silica cement present, the quartz grains are attached to cement, which creates a rim around the quartz grain called overgrowth. The overgrowth retains the same crystallographic continuity of quartz framework grain that is being cemented. Opal cement is found in sandstones that are rich in volcanogenic materials, and very rarely is in other sandstones. Calcite cement is the most common carbonate cement. Calcite cement is an assortment of smaller calcite crystals. The cement adheres to the framework grains, cementing the framework grains together. Other minerals that act as cements include: hematite, limonite, feldspars, anhydrite, gypsum, barite, clay minerals, and zeolite minerals. Sandstone that becomes depleted of its cement binder through weathering gradually becomes friable and unstable. This process can be somewhat reversed by the application of tetraethyl orthosilicate (Si(OC2H5)4) which will deposit amorphous silicon dioxide between the sand grains. The reaction is as follows. Si(OC2H5)4 (l) + 2 H2O (l) → SiO2 (s) + 4 C2H5OH (g) Pore space Pore space includes the open spaces within a rock or a soil. The pore space in a rock has a direct relationship to the porosity and permeability of the rock. The porosity and permeability are directly influenced by the way the sand grains are packed together. Porosity is the percentage of bulk volume that is inhabited by interstices within a given rock. Porosity is directly influenced by the packing of even-sized spherical grains, rearranged from loosely packed to tightest packed in sandstones. Permeability is the rate in which water or other fluids flow through the rock. For groundwater, work permeability may be measured in gallons per day through a one square foot cross section under a unit hydraulic gradient. Types of sandstone Sandstones are typically classified by point-counting a thin section using a method like the Gazzi-Dickinson Method. This yields the relative percentages of quartz, feldspar, and lithic grains and the amount of clay matrix. The composition of a sandstone can provide important information on the genesis of the sediments when used with a triangular Quartz, Feldspar, Lithic fragment (QFL diagrams). However, geologist have
A year after their meeting, the Parliament of England passed the Act of Settlement 1701 declaring that, in the event of no legitimate issue from Anne or William III, the crowns of England and Ireland were to settle upon "the most excellent princess Sophia, electress and duchess-dowager of Hanover" and "the heirs of her body, being Protestant". Scotland being a separate state in international law at the time, this did not mean she would also succeed Anne as Queen of Scotland, which led to a succession crisis and eventually to the Treaty of Union between Scotland and England in 1706/07. The key excerpt from the Act, naming Sophia as heir presumptive, reads: Therefore for a further Provision of the Succession of the Crown in the Protestant Line We Your Majesties most dutifull and Loyall Subjects the Lords Spirituall and Lords Temporall and Commons in this present Parliament assembled do beseech Your Majesty that it may be enacted and declared and be it enacted and declared by the Kings most Excellent Majesty by and with the Advice and Consent of the Lords Spirituall and Temporall and Commons in this present Parliament assembled and by the Authority of the same That the most Excellent Princess Sophia Electress and Dutchess Dowager of Hannover Daughter of the most Excellent Princess Elizabeth late Queen of Bohemia Daughter of our late Sovereign Lord King James the First of happy Memory be and is hereby declared to be the next in Succession in the Protestant Line to the Imperiall Crown and Dignity of the forsaid Realms of England France and Ireland with the Dominions and Territories thereunto belonging after His Majesty and the Princess Anne of Denmark and in Default of Issue of the said Princess Anne and of His Majesty respectively. Sophia was made heir presumptive to cut off a claim by the Roman Catholic James Francis Edward Stuart, who would have become James III and VIII and to deny the throne to the many other Roman Catholics and spouses of Roman Catholics who held a claim. The act restricts the British throne to the "Protestant heirs" of Sophia of Hanover who had never been Roman Catholic or married a Roman Catholic. Some British politicians attempted several times to bring Sophia to England in order to enable her to assume government immediately in the event of Anne's death. It was argued that such a course was necessary to ensure Sophia's succession, for Anne's Roman Catholic half-brother was significantly closer to London than was Sophia. The Electress was eager to move to London, but the proposal was denied, as such action would mortally offend Anne who was strongly opposed to a rival court in her kingdom. Anne might have been aware that Sophia, who was active and lively despite her old age, could cut a better figure than herself. Sophia was completely uncertain of what would happen after Anne's death, saying: "What Parliament does one day, it undoes the next." When the law was passed in mid-1701, Sophia at age 70, five of her children from ages 35 to 41, and three legitimate grandchildren from ages 14 to 18, were alive. Although Sophia was in her seventy-first year, older than Anne by thirty-five years, she was very fit and healthy, and invested time and energy in securing the succession either for herself or her son. There are more than 5,000 legitimate descendants of Sophia, although not all are in the line of succession. The Sophia Naturalization Act 1705 granted the right of British (or more correctly English, as Great Britain only came into existence in 1707) nationality to Sophia's non-Roman Catholic descendants; those who had obtained the right to British citizenship via this Act at any time before its repeal by the British Nationality Act 1948 retain this lawful right today. Death and legacy Although considerably older than Queen Anne, Sophia enjoyed much better health. According to the Countess of Bückeburg in a letter to Sophia's niece, the Raugravine Luise, on 5 June 1714 Sophia felt ill after receiving an angry letter from Queen Anne. Three days later on 8 June she was walking in the gardens of Herrenhausen when she ran to shelter from a sudden downpour of rain and collapsed and died, aged 83—a very advanced age for the era. Just under two months later, on 1 August 1714, Queen Anne died at the age of 49. Had Sophia survived Anne, she would have been the oldest person to ascend the British throne. Upon Sophia's death, her eldest son Elector George Louis of Brunswick-Lüneburg (1660–1727) became heir presumptive in her place and within two months succeeded Anne as George I of Great Britain. Sophia's daughter Sophia Charlotte of Hanover (1668–1705) married Frederick I of Prussia, from whom the later Prussian and German monarchs descend. Sophia was buried in the chapel of Leine Palace in Hanover, as were her husband and, later, their son George I. After destruction of the palace and its chapel during World War II by British air raids, their remains were moved into the mausoleum of King Ernest Augustus I in the Berggarten of Herrenhausen Gardens in 1957. Ancestry Notes References Israel, Johnathan I. Radical Enlightenment. Oxford University Press, 2001, 84. Further reading Duggan, J. N., Sophia of Hanover, From Winter Princess to Heiress of Great Britain; London, Peter Owen, 2010 Klopp, Onno (ed.), Correspondance de Leibniz avec l'électrice Sophie. Hanover, 1864–1875 Van der Cruysse, Dirk; Sophie de Hanovre,	seven children who reached adulthood. They were: George I of Great Britain (1660–1727) Frederick Augustus (1661–90), Imperial General Maximilian William of Brunswick-Lüneburg (1666–1726), field marshal in the Imperial Army Sophia Charlotte (1668–1705), Queen in Prussia Charles Philip of Brunswick-Lüneburg (1669–90), colonel in the Imperial Army Christian Henry of Brunswick-Lüneburg (1671–1703) Ernest Augustus of Brunswick-Lüneburg, Duke of York and Albany (1674–1728), became prince-bishop of Osnabrück Three of her sons were killed in battle. Sophia was absent for almost a year, 1664–65, during a long holiday with Ernest Augustus in Italy. She corresponded regularly with her sons' governess and took a great interest in her sons' upbringing, even more so on her return. After Sophia's tour, she bore Ernest Augustus another four sons and a daughter. In her letters, Sophia describes her eldest son as a responsible, conscientious child who set an example to his younger brothers and sisters. Sophia was, at first, against the marriage of her son George and Sophia Dorothea of Celle, looking down on Sophia Dorothea's mother (who was not of royal birth and who Sophia referred to as "mouse dirt mixed among the pepper") and concerned by Sophia Dorothea's legitimated status, but was eventually won over by the advantages inherent in the marriage. Heir presumptive In September 1700, Sophia met her cousin King William III of England at Het Loo Palace in Apeldoorn, the Netherlands. This happened two months after the death of his nephew Prince William, Duke of Gloucester, son of the future Queen Anne. By this time, given the ailing William III's reluctance to remarry, the inclusion of Sophia in the line of succession was becoming more likely because she was a Protestant, as was her son. Her candidature was aided by the fact that she had grown up in the Netherlands close to William III and was able to converse fluently with him in Dutch, his native tongue. A year after their meeting, the Parliament of England passed the Act of Settlement 1701 declaring that, in the event of no legitimate issue from Anne or William III, the crowns of England and Ireland were to settle upon "the most excellent princess Sophia, electress and duchess-dowager of Hanover" and "the heirs of her body, being Protestant". Scotland being a separate state in international law at the time, this did not mean she would also succeed Anne as Queen of Scotland, which led to a succession crisis and eventually to the Treaty of Union between Scotland and England in 1706/07. The key excerpt from the Act, naming Sophia as heir presumptive, reads: Therefore for a further Provision of the Succession of the Crown in the Protestant Line We Your Majesties most dutifull and Loyall Subjects the Lords Spirituall and Lords Temporall and Commons in this present Parliament assembled do beseech Your Majesty that it may be enacted and declared and be it enacted and declared by the Kings most Excellent Majesty by and with the Advice and Consent of the Lords Spirituall and Temporall and Commons in this present Parliament assembled and by the Authority of the same That the most Excellent Princess Sophia Electress and Dutchess Dowager of Hannover Daughter of the most Excellent Princess Elizabeth late Queen of Bohemia Daughter of our late Sovereign Lord King James the First of happy Memory be and is hereby declared to be the next in Succession in the Protestant Line to the Imperiall Crown and Dignity of the forsaid Realms of England France and Ireland with the Dominions and Territories thereunto belonging after His Majesty and the Princess Anne of Denmark and in Default of Issue of the said Princess Anne and of His Majesty respectively. Sophia was made heir presumptive to cut off a claim by the Roman Catholic James Francis Edward Stuart, who would have become James III and VIII and to deny the throne to the many other Roman Catholics and spouses of Roman Catholics who held a claim. The act restricts the British throne to the "Protestant heirs" of Sophia of Hanover who had never been Roman Catholic or married a Roman Catholic. Some British politicians attempted several times to bring Sophia to England in order to enable her to assume government immediately in the event of Anne's death. It was argued that such a course was necessary to ensure Sophia's succession, for Anne's Roman Catholic half-brother was significantly closer to London than was Sophia. The Electress was eager to move to London, but the proposal was denied, as such action would mortally offend Anne who was strongly opposed to a rival court in her kingdom. Anne might have been aware that Sophia, who was active and lively despite her old age, could cut a better figure than herself. Sophia was completely uncertain of what would happen after Anne's death, saying: "What Parliament does one day, it undoes the next." When the law was passed in mid-1701, Sophia at age 70, five of her children from ages 35 to 41, and three legitimate grandchildren from ages 14 to 18, were alive. Although Sophia was in her seventy-first year, older than Anne by thirty-five years, she was very fit and healthy, and invested time and energy in securing the succession either for herself or her son. There are more than 5,000 legitimate descendants of Sophia, although not all are in the line of succession. The Sophia Naturalization Act 1705 granted the right of British (or more correctly English, as Great Britain only came into existence in 1707) nationality to Sophia's non-Roman Catholic descendants; those who had obtained the right to
adjusts the height of the tip. Principle of operation Quantum tunneling of electrons is a functioning concept of STM that arises from quantum mechanics. Classically, a particle hitting an impenetrable barrier will not pass through. If the barrier is described by a potential acting along z-direction in which an electron of mass me acquires the potential energy U(z), the electron's trajectory will be deterministic, and such that the sum E of its kinetic and potential energies is at all times conserved, The electron will have a defined, non-zero momentum p only in regions where the initial energy E is greater than U(z). In quantum physics, however, particles with a very small mass, such as the electron, have discernible wavelike characteristics and are allowed to leak into classically forbidden regions. This is referred to as tunneling. Rectangular barrier model The simplest model of tunneling between the sample and the tip of a scanning tunneling microscope is that of a rectangular potential barrier. An electron of energy E is incident upon an energy barrier of height U, in the region of space of width w. Electron's behavior in the presence of a potential U(z), assuming one-dimensional case, is described by wave functions that satisfy Schrödinger’s equation, Here, ħ is the reduced Planck’s constant, z is the position, and me is the mass of an electron. In the zero-potential regions on two sides of the barrier, the wave function takes on the following form , for z<0 , for z>w Here, . Inside the barrier, where E < U, the wave function is a superposition of two terms, each decaying from one side of the barrier , for 0<z<w where . The coefficients r and t provide measure of how much of the incident electron's wave is reflected or transmitted through the barrier. Namely, of the whole impinging particle current only will be transmitted, as can be seen from the probability current expression which evaluates to . The transmission coefficient is obtained from the continuity condition on the three parts of the wave function and their derivatives at z=0 and z=w (detailed derivation is in the article Rectangular potential barrier). This gives where . The expression can be further simplified, as follows: In STM experiments, typical barrier height is of the order of the material's surface work function W, which for most metals has a value between 4 and 6 eV. The work function is the minimum energy needed to bring an electron from an occupied level, the highest of which is the Fermi level (for metals at T=0 kelvin), to vacuum level. The electrons can tunnel between two metals only from occupied states on one side into the unoccupied states of the other side of the barrier. Without bias, Fermi energies are flush and there is no tunneling. Bias shifts electron energies in one of the electrodes higher, and those electrons that have no match at the same energy on the other side will tunnel. In experiments, bias voltages of a fraction of 1 V are used, so is of the order of 10 to 12 nm−1, while w is a few tenths of a nanometer. The barrier is strongly attenuating. The expression for the transmission probability reduces to . The tunneling current from a single level is therefore where both wave vectors depend on the level's energy E; and . Tunneling current is exponentially dependent on the separation of the sample and the tip, and typically reduces by an order of magnitude when the separation is increased by 1 Å (0.1 nm). Because of this, even when tunneling occurs from a non-ideally sharp tip, the dominant contribution to the current is from its most protruding atom or orbital. Tunneling between two conductors As a result of the restriction that the tunneling from an occupied energy level on one side of the barrier requires an empty level of the same energy on the other side of the barrier, tunneling occurs mainly with electrons near the Fermi level. The tunneling current can be related to the density of available or filled states in the sample. The current due to an applied voltage V (assume tunneling occurs from the sample to the tip) depends on two factors: 1) the number of electrons between the Fermi level EF and EF−eV in the sample, and 2) the number among them which have corresponding free states to tunnel into on the other side of the barrier at the tip. The higher the density of available states in the tunneling region the greater the tunneling current. By convention, a positive V means that electrons in the tip tunnel into empty states in the sample; for a negative bias, electrons tunnel out of occupied states in the sample into the tip. For small biases and temperatures near absolute zero, the number of electrons in a given volume (the electron concentration) that are available for tunneling is the product of the density of the electronic states ρ(EF) and the energy interval between the two Fermi levels, eV. Half of these electrons will be travelling away from the barrier. The other half will represent the electric current impinging on the barrier, which is given by the product of the electron concentration, charge, and velocity v (Ii=nev), . The tunneling electric current will be a small fraction of the impinging current. The proportion is determined by the transmission probability T, so . In the simplest model of a rectangular potential barrier the transmission probability coefficient T equals \|t\|2. Bardeen's formalism A model that is based on more realistic wave functions for the two electrodes was devised by John Bardeen in a study of the metal-insulator-metal junction. His model takes two separate orthonormal sets of wave functions for the two electrodes and examines their time evolution as the systems are put close together. Bardeen's novel method, ingenious in itself, solves a time-dependent perturbative problem in which the perturbation emerges from the interaction of the two subsystems rather than an external potential of the standard Rayleigh–Schrödinger perturbation theory. Each of the wave functions for the electrons of the sample (S) and the tip (T) decay into the vacuum after hitting the surface potential barrier, roughly of the size of the surface work function. The wave functions are the solutions of two separate Schrödinger's equations for electrons in potentials US and UT. When the time dependence of the states of known energies and is factored out, the wave functions have the following general form If the two systems are put closer together, but are still separated by a thin vacuum region, the potential acting on an electron in the combined system is UT + US. Here, each of the potentials is spatially limited to its own side of the barrier. Only because the tail of a wave function of one electrode is in the range of the potential of the other, there is a finite probability for any state to evolve over time into the states of the other electrode. The future of the sample's state μ can be written as a linear combination with time-dependent coefficients of and all , with the initial condition . When the new wave function is inserted into the Schrödinger’s equation for the potential UT + US, the obtained equation is projected onto each separate (that is, the equation is multiplied by a and integrated over the whole volume) to single out the coefficients . All are taken to be nearly orthogonal to all (their overlap is a small fraction of the total wave functions), and only first order quantities retained. Consequently, the time evolution of the coefficients is given by . Because the potential UT is zero at the distance of a few atomic diameters away from the surface of the electrode, the integration over z can be done from a point zo somewhere inside the barrier and into the volume of the tip (z>zo). If the tunneling matrix element is defined as , the probability of the sample's state μ evolving in time t into the state of the tip ν is . In a system with many electrons impinging on the barrier, this probability will give the proportion of those that successfully tunnel. If at a time t this fraction was , at a later time t+dt the total fraction of would have tunneled. The current of tunneling electrons at each instance is therefore proportional to divided by , which is the time derivative of , . The time scale of the measurement in STM is many orders of magnitude larger than the typical femtosecond time scale of electron processes in materials, and is large. The fraction part of the formula is a fast oscillating function of that rapidly decays away from the central peak where . In other words, the most probable tunneling process, by far, is the elastic one, in which the electron's energy is conserved. The fraction, as written above, is a representation of the delta function, so . Solid-state systems are commonly described in terms of continuous rather than discrete energy levels. The term can be thought of as the density of states of the tip at energy , giving . The number of energy levels in the sample between the energies and is . When occupied, these levels are spin-degenerate (except in a few special classes of materials) and contain charge of either spin. With the sample biased to voltage , tunneling can occur only between states whose occupancies, given for each electrode by the Fermi–Dirac distribution , are not the same, that is, when either one or the other is occupied, but not both. That will be for all energies for which is not zero. For example, an electron will tunnel from energy level in the sample into energy level in the tip (), an electron at in the sample will find unoccupied states in the tip at (), and so will be for all energies in-between. The tunneling current is therefore the sum of little contributions over all these energies of the product of three factors: representing available electrons, for those that are allowed to tunnel, and the probability factor for those that will actually tunnel. . Typical experiments are run at a liquid helium temperature (around 4 K) at which the Fermi level cut-off of the electron population is less than a millielectronvolt wide. The allowed energies are only those between the two step-like Fermi levels, and the integral becomes . When the bias is small, it is reasonable to assume that the electron wave functions and, consequently, the tunneling matrix element do not change significantly in the narrow range of energies. Then the tunneling current is simply the convolution of the densities of states of the sample surface and the tip, . How the tunneling current depends on distance between the two electrodes is contained in the tunneling matrix element . This formula can be transformed so that no explicit dependence on the potential remains. First, the part is taken out from the Schrödinger equation for the tip, and the elastic tunneling condition is used so that . Now is present in the Schrödinger equation for the sample, and equals the kinetic plus the potential operator acting on . However, the potential part containing US is on the tip side of the barrier nearly zero. What remains, can be integrated over z because the integrand in the parentheses equals . Bardeen's tunneling matrix element is an integral of the wave functions and their gradients over a surface separating the two planar electrodes, . The exponential dependence of the tunneling current on the separation of the electrodes comes from the very wave functions that leak through the potential step at the surface and exhibit exponential decay into the classically forbidden region outside of the material. The tunneling matrix elements show appreciable energy dependence, which is such that tunneling from the upper end of the eV interval is nearly an order of magnitude more likely than tunneling from the states at its bottom. When the sample is biased positively, its unoccupied levels are probed as if the density of states of the tip is concentrated at its Fermi level. Conversely, when the sample is biased negatively, its occupied electronic states are probed but the spectrum of the electronic states of the tip dominates. In this case it is important that the density of states of the tip is as flat as possible.	separation is increased by 1 Å (0.1 nm). Because of this, even when tunneling occurs from a non-ideally sharp tip, the dominant contribution to the current is from its most protruding atom or orbital. Tunneling between two conductors As a result of the restriction that the tunneling from an occupied energy level on one side of the barrier requires an empty level of the same energy on the other side of the barrier, tunneling occurs mainly with electrons near the Fermi level. The tunneling current can be related to the density of available or filled states in the sample. The current due to an applied voltage V (assume tunneling occurs from the sample to the tip) depends on two factors: 1) the number of electrons between the Fermi level EF and EF−eV in the sample, and 2) the number among them which have corresponding free states to tunnel into on the other side of the barrier at the tip. The higher the density of available states in the tunneling region the greater the tunneling current. By convention, a positive V means that electrons in the tip tunnel into empty states in the sample; for a negative bias, electrons tunnel out of occupied states in the sample into the tip. For small biases and temperatures near absolute zero, the number of electrons in a given volume (the electron concentration) that are available for tunneling is the product of the density of the electronic states ρ(EF) and the energy interval between the two Fermi levels, eV. Half of these electrons will be travelling away from the barrier. The other half will represent the electric current impinging on the barrier, which is given by the product of the electron concentration, charge, and velocity v (Ii=nev), . The tunneling electric current will be a small fraction of the impinging current. The proportion is determined by the transmission probability T, so . In the simplest model of a rectangular potential barrier the transmission probability coefficient T equals \|t\|2. Bardeen's formalism A model that is based on more realistic wave functions for the two electrodes was devised by John Bardeen in a study of the metal-insulator-metal junction. His model takes two separate orthonormal sets of wave functions for the two electrodes and examines their time evolution as the systems are put close together. Bardeen's novel method, ingenious in itself, solves a time-dependent perturbative problem in which the perturbation emerges from the interaction of the two subsystems rather than an external potential of the standard Rayleigh–Schrödinger perturbation theory. Each of the wave functions for the electrons of the sample (S) and the tip (T) decay into the vacuum after hitting the surface potential barrier, roughly of the size of the surface work function. The wave functions are the solutions of two separate Schrödinger's equations for electrons in potentials US and UT. When the time dependence of the states of known energies and is factored out, the wave functions have the following general form If the two systems are put closer together, but are still separated by a thin vacuum region, the potential acting on an electron in the combined system is UT + US. Here, each of the potentials is spatially limited to its own side of the barrier. Only because the tail of a wave function of one electrode is in the range of the potential of the other, there is a finite probability for any state to evolve over time into the states of the other electrode. The future of the sample's state μ can be written as a linear combination with time-dependent coefficients of and all , with the initial condition . When the new wave function is inserted into the Schrödinger’s equation for the potential UT + US, the obtained equation is projected onto each separate (that is, the equation is multiplied by a and integrated over the whole volume) to single out the coefficients . All are taken to be nearly orthogonal to all (their overlap is a small fraction of the total wave functions), and only first order quantities retained. Consequently, the time evolution of the coefficients is given by . Because the potential UT is zero at the distance of a few atomic diameters away from the surface of the electrode, the integration over z can be done from a point zo somewhere inside the barrier and into the volume of the tip (z>zo). If the tunneling matrix element is defined as , the probability of the sample's state μ evolving in time t into the state of the tip ν is . In a system with many electrons impinging on the barrier, this probability will give the proportion of those that successfully tunnel. If at a time t this fraction was , at a later time t+dt the total fraction of would have tunneled. The current of tunneling electrons at each instance is therefore proportional to divided by , which is the time derivative of , . The time scale of the measurement in STM is many orders of magnitude larger than the typical femtosecond time scale of electron processes in materials, and is large. The fraction part of the formula is a fast oscillating function of that rapidly decays away from the central peak where . In other words, the most probable tunneling process, by far, is the elastic one, in which the electron's energy is conserved. The fraction, as written above, is a representation of the delta function, so . Solid-state systems are commonly described in terms of continuous rather than discrete energy levels. The term can be thought of as the density of states of the tip at energy , giving . The number of energy levels in the sample between the energies and is . When occupied, these levels are spin-degenerate (except in a few special classes of materials) and contain charge of either spin. With the sample biased to voltage , tunneling can occur only between states whose occupancies, given for each electrode by the Fermi–Dirac distribution , are not the same, that is, when either one or the other is occupied, but not both. That will be for all energies for which is not zero. For example, an electron will tunnel from energy level in the sample into energy level in the tip (), an electron at in the sample will find unoccupied states in the tip at (), and so will be for all energies in-between. The tunneling current is therefore the sum of little contributions over all these energies of the product of three factors: representing available electrons, for those that are allowed to tunnel, and the probability factor for those that will actually tunnel. . Typical experiments are run at a liquid helium temperature (around 4 K) at which the Fermi level cut-off of the electron population is less than a millielectronvolt wide. The allowed energies are only those between the two step-like Fermi levels, and the integral becomes . When the bias is small, it is reasonable to assume that the electron wave functions and, consequently, the tunneling matrix element do not change significantly in the narrow range of energies. Then the tunneling current is simply the convolution of the densities
technique to create random mutants STMicroelectronics, an Italian-French manufacturer of electronics and semiconductors STM (Turkish company) (), a military technology company in Turkey STM-1, Synchronous Transport Module, the basic rate of transmission of the SDH ITU-T fiber optic network STM32, a family of 32-bit microcontroller integrated circuits by STMicroelectronics Software transactional memory, a method of handling concurrency in multithreaded systems Stepper motor, a type of electric motor Canon autofocus lenses that use stepper motor technology which makes them especially quiet .stm, a filename extension used by: Web administration panel, of Belkin routers Streaming Media File, in Microsoft Exchange Server Scream Tracker, music tracker software Transportation Société de transport de Montréal, the public	Software transactional memory, a method of handling concurrency in multithreaded systems Stepper motor, a type of electric motor Canon autofocus lenses that use stepper motor technology which makes them especially quiet .stm, a filename extension used by: Web administration panel, of Belkin routers Streaming Media File, in Microsoft Exchange Server Scream Tracker, music tracker software Transportation Société de transport de Montréal, the public transport provider in Montreal, Quebec, Canada Amtrak ticketing code for Stamford Transportation Center, a railway station in Stamford, Connecticut, US Sea traffic management, a set of systems and procedures to guide and monitor sea traffic in a manner similar to air traffic management Space traffic management Strategic Traffic Manager, a Bus Priority application designed to work as part of an intelligent transportation system Santarém-Maestro Wilson Fonseca Airport, Santarém, Pará\|Santarém, Brazil, by IATA airport code Publishing International Association of Scientific, Technical, and Medical
of 2021, when the latest volume appeared, work has progressed to the letter Å inclusively. The dictionary has approximately 450,000 main entries. The searchable web version has been available since 1997. See also Svenska Akademiens ordlista External links Svenska Akademiens ordbok The Swedish Academy – Official site (in English) Swedish	the letter Å inclusively. The dictionary has approximately 450,000 main entries. The searchable web version has been available since 1997. See also Svenska Akademiens ordlista External links Svenska Akademiens ordbok The Swedish Academy – Official site (in English) Swedish non-fiction literature
Riley, known collectively as Mark and Lard. As part of their BBC Radio 1 shows, the pair produced pastiches of chart songs, such as "You're Gormless", a parody of Babybird's "You're Gorgeous", "Lardy Boy", a parody of Placebo's "Nancy Boy", and "Why Is It Always Dairylea", spoofing Travis's "Why Does It Always Rain on Me?", using the band names 'Baby Bloke', 'Gazebo' and 'Dave Lee Travisty' respectively. When they rewrote The Seahorses' "Love Is the Law" as "(Now) I Know (Where I'm Going) Our Kid", they chose the stage-name Shirehorses, which they then retained for future recordings and performances. Other parodies include "I Want a Roll with It" (spoofing "Roll with It" by Oasis), "Feel Like Shite" ("Alright" by Supergrass), and "Country Spouse" ("Country House" by Blur). The band toured	Other parodies include "I Want a Roll with It" (spoofing "Roll with It" by Oasis), "Feel Like Shite" ("Alright" by Supergrass), and "Country Spouse" ("Country House" by Blur). The band toured extensively, playing many small, university gigs to exploit their popularity with students. However, they also performed at larger venues, supporting Blur on a 1997 UK tour, taking in several stadia, and appearing at Glastonbury Festival in 1997. Marc Riley was formerly a member of British Manchester band the Fall and
Ink family. Furthermore, reprogramming efficiency is correlated with the number of cell divisions happened during the stochastic phase, which is suggested by the growing inefficiency of reprogramming of older or slow diving cells. Lineage Lineage is an important procedure to analyze developing embryos. Since cell lineages shows the relationship between cells at each division. This helps in analyzing stem cell lineages along the way which helps recognize stem cell effectiveness, lifespan, and other factors. With the technique of cell lineage mutant genes can be analyzed in stem cell clones that can help in genetic pathways. These pathways can regulate how the stem cell perform. To ensure self-renewal, stem cells undergo two types of cell division (see Stem cell division and differentiation diagram). Symmetric division gives rise to two identical daughter cells both endowed with stem cell properties. Asymmetric division, on the other hand, produces only one stem cell and a progenitor cell with limited self-renewal potential. Progenitors can go through several rounds of cell division before terminally differentiating into a mature cell. It is possible that the molecular distinction between symmetric and asymmetric divisions lies in differential segregation of cell membrane proteins (such as receptors) between the daughter cells. An alternative theory is that stem cells remain undifferentiated due to environmental cues in their particular niche. Stem cells differentiate when they leave that niche or no longer receive those signals. Studies in Drosophila germarium have identified the signals decapentaplegic and adherens junctions that prevent germarium stem cells from differentiating. Therapies Stem cell therapy is the use of stem cells to treat or prevent a disease or condition. Bone marrow transplant is a form of stem cell therapy that has been used for many years because it has proven to be effective in clinical trials. Stem cell implantation may help in strengthening the left-ventricle of the heart, as well as retaining the heart tissue to patients who have suffered from heart attacks in the past. Advantages Stem cell treatments may lower symptoms of the disease or condition that is being treated. The lowering of symptoms may allow patients to reduce the drug intake of the disease or condition. Stem cell treatment may also provide knowledge for society to further stem cell understanding and future treatments. The physicians' creed would be to do no injury, and stem cells make that simpler than ever before. Surgical processes by their character are harmful. Tissue has to be dropped as a way to reach a successful outcome. One may prevent the dangers of surgical interventions using stem cells. Additionally, there's a possibility of disease, and whether the procedure fails, further surgery may be required. Risks associated with anesthesia can also be eliminated with stem cells. On top of that, stem cells have been harvested from the patient's body and redeployed in which they're wanted. Since they come from the patient’s own body, this is referred to as an autologous treatment. Autologous remedies are thought to be the safest because there's likely zero probability of donor substance rejection. Disadvantages Stem cell treatments may require immunosuppression because of a requirement for radiation before the transplant to remove the person's previous cells, or because the patient's immune system may target the stem cells. One approach to avoid the second possibility is to use stem cells from the same patient who is being treated. Pluripotency in certain stem cells could also make it difficult to obtain a specific cell type. It is also difficult to obtain the exact cell type needed, because not all cells in a population differentiate uniformly. Undifferentiated cells can create tissues other than desired types. Some stem cells form tumors after transplantation; pluripotency is linked to tumor formation especially in embryonic stem cells, fetal proper stem cells, induced pluripotent stem cells. Fetal proper stem cells form tumors despite multipotency. Ethical concerns are also raised about the practice of using or researching embryonic stem cells. Harvesting cells from the blastocyst result in the death of the blastocyst. The concern is whether or not the blastocyst should be considered as a human life. The debate on this issue is mainly a philosophical one, not a scientific one. Stem cell tourism Stem cell tourism is the industry in which patients (and sometimes their families) travel to another jurisdiction, to obtain stem cell procedures which are not approved but which are advertised on the Internet as proven cures. The United States, in recent years, has had an explosion of "stem cell clinics". Stem cell procedures are highly profitable for clinics. The advertising sounds authoritative but the efficacy and safety of the procedures is unproven. Patients sometimes experience complications, such as spinal tumors and death. The high expense can also lead to financial ruin. According to researchers, there is a need to educate the public, patients, and doctors about this issue. According to the International Society for Stem Cell Research, the largest academic organization that advocates for stem cell research, stem cell therapies are under development and cannot yet be said to be proven. Doctors should inform patients that clinical trials continue to investigate whether these therapies are safe and effective but that unethical clinics present them as proven. Research Some of the fundamental patents covering human embryonic stem cells are owned by the Wisconsin Alumni Research Foundation (WARF) – they are patents 5,843,780, 6,200,806, and 7,029,913 invented by James A. Thomson. WARF does not enforce these patents against academic scientists, but does enforce them against companies. In 2006, a request for the US Patent and Trademark Office (USPTO) to re-examine the three patents was filed by the Public Patent Foundation on behalf of its client, the non-profit patent-watchdog group Consumer Watchdog (formerly the Foundation for Taxpayer and Consumer Rights). In the re-examination process, which involves several rounds of discussion between the USPTO and the parties, the USPTO initially agreed with Consumer Watchdog and rejected all the claims in all three patents, however in response, WARF amended the claims of all three patents to make them more narrow, and in 2008 the USPTO found the amended claims in all three patents to be patentable. The decision on one of the patents (7,029,913) was appealable, while the decisions on the other two were not. Consumer Watchdog appealed the granting of the '913 patent to the USPTO's Board of Patent Appeals and Interferences (BPAI) which granted the appeal, and in 2010 the BPAI decided that the amended claims of the '913 patent were not patentable. However, WARF was able to re-open prosecution of the case and did so, amending the claims of the '913 patent again to make them more narrow, and in January 2013 the amended claims were allowed. In July 2013, Consumer Watchdog announced that it would appeal the decision to allow the claims of the '913 patent to the US Court of Appeals for the Federal Circuit (CAFC), the federal appeals court that hears patent cases. At a hearing in December 2013, the CAFC raised the question of whether Consumer Watchdog had legal standing to appeal; the case could not proceed until that issue was resolved. Investigations Diseases and conditions where stem cell treatment is being investigated include: Diabetes Androgenic Alopecia and hair loss Rheumatoid arthritis Parkinson's disease Alzheimer's disease Osteoarthritis Stroke and traumatic brain injury repair Learning disability due to congenital disorder Spinal cord injury repair Heart infarction Anti-cancer treatments Baldness reversal Replace missing teeth Repair hearing Restore vision and repair damage to the cornea Amyotrophic lateral sclerosis Crohn's disease Wound healing Male infertility due to absence of spermatogonial stem cells. In recent studies, scientist have found a way to solve this problem by reprogramming a cell and turning it into a spermatozoon. Other studies have proven the restoration of spermatogenesis by introducing human iPSC cells in mice testicles. This could mean the end of azoospermia. Female infertility: oocytes made from embryonic stem cells. Scientists have found the ovarian stem cells, a rare type of cells (0.014%) found in the ovary. They could be used as a treatment not only for infertility, but also for premature ovarian insufficiency. Research is underway to develop various sources for stem cells, and to apply stem cell treatments for neurodegenerative diseases and conditions, diabetes, heart disease, and other conditions. Research is also underway in generating organoids using stem cells, which would allow for further understanding of human development, organogenesis, and modeling of human diseases. In more recent years, with the ability of scientists to isolate and culture embryonic stem cells, and with scientists' growing ability to create stem cells using somatic cell nuclear transfer and techniques to create induced pluripotent stem cells, controversy has crept in, both related to abortion politics and to human cloning. Hepatotoxicity and drug-induced liver injury account for a substantial number of failures of new drugs in development and market withdrawal, highlighting the need for screening assays such as stem cell-derived hepatocyte-like cells, that are capable of detecting toxicity early in the drug development process. Notable studies In August 2021, researchers in the Princess Margaret Cancer Centre at the University Health Network published their discovery of a dormancy mechanism in key stem cells which could help develop cancer treatments in the future. See also Cell bank Human genome Meristem Mesenchymal stem cell Partial cloning Plant stem cell Stem cell controversy Stem cell marker References Further reading External links National Institutes	accident. The workers all survived. In 1981, embryonic stem (ES) cells were first isolated and successfully cultured using mouse blastocysts by British biologists Martin Evans and Matthew Kaufman. This allowed the formation of murine genetic models, a system in which the genes of mice are deleted or altered in order to study their function in pathology. By 1998, embryonic stem cells were first isolated by American biologist James Thomson, which made it possible to have new transplantation methods or various cell types for testing new treatments. In 2006, Shinya Yamanaka’s team in Kyoto, Japan converted fibroblasts into pluripotent stem cells by modifying the expression of only four genes. The feat represents the origin of induced pluripotent stem cells, known as iPS cells. In 2011, a female maned wolf, run over by a truck, underwent stem cell treatment at the Zoo Brasília, this being the first recorded case of the use of stem cells to heal injuries in a wild animal. Properties The classical definition of a stem cell requires that it possesses two properties: Self-renewal: the ability to go through numerous cycles of cell growth and cell division, known as cell proliferation, while maintaining the undifferentiated state. Potency: the capacity to differentiate into specialized cell types. In the strictest sense, this requires stem cells to be either totipotent or pluripotent—to be able to give rise to any mature cell type, although multipotent or unipotent progenitor cells are sometimes referred to as stem cells. Apart from this, it is said that stem cell function is regulated in a feedback mechanism. Self-renewal Two mechanisms ensure that a stem cell population is maintained (doesn't shrink in size): 1. Asymmetric cell division: a stem cell divides into one mother cell, which is identical to the original stem cell, and another daughter cell, which is differentiated. When a stem cell self-renews, it divides and does not disrupt the undifferentiated state. This self-renewal demands control of cell cycle as well as upkeep of multipotency or pluripotency, which all depends on the stem cell. 2. Stochastic differentiation: when one stem cell grows and divides into two differentiated daughter cells, another stem cell undergoes mitosis and produces two stem cells identical to the original. Stem cells use telomerase, a protein that restores telomeres, to protect their DNA and extend their cell division limit (the Hayflick limit). Potency meaning Potency specifies the differentiation potential (the potential to differentiate into different cell types) of the stem cell. Totipotent (also known as omnipotent) stem cells can differentiate into embryonic and extraembryonic cell types. Such cells can construct a complete, viable organism. These cells are produced from the fusion of an egg and sperm cell. Cells produced by the first few divisions of the fertilized egg are also totipotent. Pluripotent stem cells are the descendants of totipotent cells and can differentiate into nearly all cells, i.e. cells derived from any of the three germ layers. Multipotent stem cells can differentiate into a number of cell types, but only those of a closely related family of cells. Oligopotent stem cells can differentiate into only a few cell types, such as lymphoid or myeloid stem cells. Unipotent cells can produce only one cell type, their own, but have the property of self-renewal, which distinguishes them from non-stem cells (e.g. progenitor cells, which cannot self-renew). Identification In practice, stem cells are identified by whether they can regenerate tissue. For example, the defining test for bone marrow or hematopoietic stem cells (HSCs) is the ability to transplant the cells and save an individual without HSCs. This demonstrates that the cells can produce new blood cells over a long term. It should also be possible to isolate stem cells from the transplanted individual, which can themselves be transplanted into another individual without HSCs, demonstrating that the stem cell was able to self-renew. Properties of stem cells can be illustrated in vitro, using methods such as clonogenic assays, in which single cells are assessed for their ability to differentiate and self-renew. Stem cells can also be isolated by their possession of a distinctive set of cell surface markers. However, in vitro culture conditions can alter the behavior of cells, making it unclear whether the cells shall behave in a similar manner in vivo. There is considerable debate as to whether some proposed adult cell populations are truly stem cells. Embryonic Embryonic stem cells (ESCs) are the cells of the inner cell mass of a blastocyst, formed prior to implantation in the uterus. In human embryonic development the blastocyst stage is reached 4–5 days after fertilization, at which time it consists of 50–150 cells. ESCs are pluripotent and give rise during development to all derivatives of the three germ layers: ectoderm, endoderm and mesoderm. In other words, they can develop into each of the more than 200 cell types of the adult body when given sufficient and necessary stimulation for a specific cell type. They do not contribute to the extraembryonic membranes or to the placenta. During embryonic development the cells of the inner cell mass continuously divide and become more specialized. For example, a portion of the ectoderm in the dorsal part of the embryo specializes as 'neurectoderm', which will become the future central nervous system. Later in development, neurulation causes the neurectoderm to form the neural tube. At the neural tube stage, the anterior portion undergoes encephalization to generate or 'pattern' the basic form of the brain. At this stage of development, the principal cell type of the CNS is considered a neural stem cell. The neural stem cells self-renew and at some point transition into radial glial progenitor cells (RGPs). Early-formed RGPs self-renew by symmetrical division to form a reservoir group of progenitor cells. These cells transition to a neurogenic state and start to divide asymmetrically to produce a large diversity of many different neuron types, each with unique gene expression, morphological, and functional characteristics. The process of generating neurons from radial glial cells is called neurogenesis. The radial glial cell, has a distinctive bipolar morphology with highly elongated processes spanning the thickness of the neural tube wall. It shares some glial characteristics, most notably the expression of glial fibrillary acidic protein (GFAP). The radial glial cell is the primary neural stem cell of the developing vertebrate CNS, and its cell body resides in the ventricular zone, adjacent to the developing ventricular system. Neural stem cells are committed to the neuronal lineages (neurons, astrocytes, and oligodendrocytes), and thus their potency is restricted. Nearly all research to date has made use of mouse embryonic stem cells (mES) or human embryonic stem cells (hES) derived from the early inner cell mass. Both have the essential stem cell characteristics, yet they require very different environments in order to maintain an undifferentiated state. Mouse ES cells are grown on a layer of gelatin as an extracellular matrix (for support) and require the presence of leukemia inhibitory factor (LIF) in serum media. A drug cocktail containing inhibitors to GSK3B and the MAPK/ERK pathway, called 2i, has also been shown to maintain pluripotency in stem cell culture. Human ESCs are grown on a feeder layer of mouse embryonic fibroblasts and require the presence of basic fibroblast growth factor (bFGF or FGF-2). Without optimal culture conditions or genetic manipulation, embryonic stem cells will rapidly differentiate. A human embryonic stem cell is also defined by the expression of several transcription factors and cell surface proteins. The transcription factors Oct-4, Nanog, and Sox2 form the core regulatory network that ensures the suppression of genes that lead to differentiation and the maintenance of pluripotency. The cell surface antigens most commonly used to identify hES cells are the glycolipids stage specific embryonic antigen 3 and 4, and the keratan sulfate antigens Tra-1-60 and Tra-1-81. The molecular definition of a stem cell includes many more proteins and continues to be a topic of research. By using human embryonic stem cells to produce specialized cells like nerve cells or heart cells in the lab, scientists can gain access to adult human cells without taking tissue from patients. They can then study these specialized adult cells in detail to try to discern complications of diseases, or to study cell reactions to proposed new drugs. Because of their combined abilities of unlimited expansion and pluripotency, embryonic stem cells remain a theoretically potential source for regenerative medicine and tissue replacement after injury or disease., however, there are currently no approved treatments using ES cells. The first human trial was approved by the US Food and Drug Administration in January 2009. However, the human trial was not initiated until October 13, 2010 in Atlanta for spinal cord injury research. On November 14, 2011 the company conducting the trial (Geron Corporation) announced that it will discontinue further development of its stem cell programs. Differentiating ES cells into usable cells while avoiding transplant rejection are just a few of the hurdles that embryonic stem cell researchers still face. Embryonic stem cells, being pluripotent, require specific signals for correct differentiation – if injected directly into another body, ES cells will differentiate into many different types of cells, causing a teratoma. Ethical considerations regarding the use of unborn human tissue are another reason for the lack of approved treatments using embryonic stem cells. Many nations currently have moratoria or limitations on either human ES cell research or the production of new human ES cell lines. Mesenchymal stem cells Mesenchymal stem cells (MSC) are known to be multipotent, which can be found in adult tissues, for example, in the muscle, liver, bone marrow. Mesenchymal stem cells usually function as structural support in various organs as mentioned above, and control the movement of substances. MSC can differentiate into numerous cell categories as an illustration of adipocytes, osteocytes, and chondrocytes, derived by the mesodermal layer. Where the mesoderm layer provides an increase to the body’s skeletal elements, such as relating to the cartilage or bone. The term “meso” means middle, infusion originated from the Greek, signifying that mesenchymal cells are able to range and travel in early embryonic growth among the ectodermal and endodermal layers. This mechanism helps with space-filling thus, key for repairing wounds in adult organisms that have to do with mesenchymal cells in the dermis (skin), bone, or muscle. Mesenchymal stem cells are known to be essential for regenerative medicine. They are broadly studied in clinical trials. Since they are easily isolated and obtain high yield, high plasticity, which makes able to facilitate inflammation and encourage cell growth, cell differentiation, and restoring tissue derived from immunomodulation and immunosuppression. MSC comes from the bone marrow, which requires an aggressive procedure when it comes to isolating the quantity and quality of the isolated cell, and it varies by how old the donor. When comparing the rates of MSC in the bone marrow aspirates and bone marrow stroma, the aspirates tend to have lower rates of MSC than the stroma. MSC are known to be heterogeneous, and they express a high level of pluripotent markers when compared to other types of stem cells, such as embryonic stem cells. Cell cycle control Embryonic stem cells (ESCs) have the ability to divide indefinitely while keeping their pluripotency, which is made possible through specialized mechanisms of cell cycle control. Compared to proliferating somatic cells, ESCs have unique cell cycle characteristics—such as rapid cell division caused by shortened G1 phase, absent G0 phase, and modifications in cell cycle checkpoints—which leaves the cells mostly in S phase at any given time. ESCs’ rapid division is demonstrated by their short doubling time, which ranges from 8 to 10 hours, whereas somatic cells have doubling time of approximately 20 hours or longer. As cells differentiate, these properties change: G1 and G2 phases lengthen, leading to longer cell division cycles. This suggests that a specific cell cycle structure may contribute to the establishment of pluripotency. Particularly because G1 phase is the phase in which cells have increased sensitivity to differentiation, shortened G1 is one of the key characteristics of ESCs and plays an important role in maintaining undifferentiated phenotype. Although the exact molecular mechanism remains only partially understood, several studies have shown insight on how ESCs progress through G1—and potentially other phases—so rapidly. The cell cycle is regulated by complex network of cyclins, cyclin-dependent kinases (Cdk), cyclin-dependent kinase inhibitors (Cdkn), pocket proteins of the retinoblastoma (Rb) family, and other accessory factors. Foundational insight into the distinctive regulation of ESC cell cycle was gained by studies on mouse ESCs (mESCs). mESCs showed a cell cycle with highly abbreviated G1 phase, which enabled cells to rapidly alternate between M phase and S phase. In a somatic cell cycle, oscillatory activity of Cyclin-Cdk complexes is observed in sequential action, which controls crucial regulators of the cell cycle to induce unidirectional transitions between phases: Cyclin D and Cdk4/6 are active in the G1 phase, while Cyclin E and Cdk2 are active during the late G1 phase and S phase; and Cyclin A and Cdk2 are active in the S phase and G2, while Cyclin B and Cdk1 are active in G2 and M phase. However, in mESCs, this typically ordered and oscillatory activity of Cyclin-Cdk complexes is absent. Rather, the Cyclin E/Cdk2 complex is constitutively active throughout the cycle, keeping retinoblastoma protein (pRb) hyperphosphorylated and thus inactive. This allows for direct transition from M phase to the late G1 phase, leading to absence of D-type cyclins and therefore a shortened G1 phase. Cdk2 activity is crucial for both cell cycle regulation and cell-fate decisions in mESCs; downregulation of Cdk2 activity prolongs G1 phase progression, establishes a somatic cell-like cell cycle, and induces expression of differentiation markers. In human ESCs (hESCs), the duration of G1 is dramatically shortened. This has been attributed to high mRNA levels of G1-related Cyclin D2 and Cdk4 genes and low levels of cell cycle regulatory
each of the first three books contained poems in a single specific metre. Ancient editions of Sappho, possibly starting with the Alexandrian edition, seem to have ordered the poems in at least the first book of Sappho's poetry – which contained works composed in Sapphic stanzas – alphabetically. Even after the publication of the standard Alexandrian edition, Sappho's poetry continued to circulate in other poetry collections. For instance, the Cologne Papyrus on which the Tithonus poem is preserved was part of a Hellenistic anthology of poetry, which contained poetry arranged by theme, rather than by metre and incipit, as it was in the Alexandrian edition. Surviving poetry The earliest surviving manuscripts of Sappho, including the potsherd on which fragment 2 is preserved, date to the third century BC, and thus predate the Alexandrian edition. The latest surviving copies of Sappho's poems transmitted directly from ancient times are written on parchment codex pages from the sixth and seventh centuries AD, and were surely reproduced from ancient papyri now lost. Manuscript copies of Sappho's works may have survived a few centuries longer, but around the 9th century her poetry appears to have disappeared, and by the twelfth century, John Tzetzes could write that "the passage of time has destroyed Sappho and her works". According to legend, Sappho's poetry was lost because the church disapproved of her morals. These legends appear to have originated in the Renaissance – around 1550, Jerome Cardan wrote that Gregory Nazianzen had Sappho's work publicly destroyed, and at the end of the sixteenth century Joseph Justus Scaliger claimed that Sappho's works were burned in Rome and Constantinople in 1073 on the orders of Pope Gregory VII. In reality, Sappho's work was probably lost as the demand for it was insufficiently great for it to be copied onto parchment when codices superseded papyrus scrolls as the predominant form of book. A contributing factor to the loss of Sappho's poems may have been her Aeolic dialect, considered provincial in a period where the Attic dialect was seen as the true classical Greek, and had become the standard for literary compositions. Consequently, many readers found Sappho's dialect difficult to understand: in the second century AD, the Roman author Apuleius specifically remarks on its "strangeness", and several commentaries on the subject demonstrate the difficulties that readers had with it. This was part of a more general decline in interest in the archaic poets; indeed, the surviving papyri suggest that Sappho's poetry survived longer than that of her contemporaries such as Alcaeus. Only approximately 650 lines of Sappho's poetry still survive, of which just one poem – the "Ode to Aphrodite" – is complete, and more than half of the original lines survive in around ten more fragments. Many of the surviving fragments of Sappho contain only a single word – for example, fragment 169A is simply a word meaning "wedding gifts", and survives as part of a dictionary of rare words. The two major sources of surviving fragments of Sappho are quotations in other ancient works, from a whole poem to as little as a single word, and fragments of papyrus, many of which were discovered at Oxyrhynchus in Egypt. Other fragments survive on other materials, including parchment and potsherds. The oldest surviving fragment of Sappho currently known is the Cologne papyrus which contains the Tithonus poem, dating to the third century BC. Until the last quarter of the nineteenth century, only the ancient quotations of Sappho survived. In 1879, the first new discovery of a fragment of Sappho was made at Fayum. By the end of the nineteenth century, Grenfell and Hunt had begun to excavate an ancient rubbish dump at Oxyrhynchus, leading to the discoveries of many previously unknown fragments of Sappho. Fragments of Sappho continue to be rediscovered. Most recently, major discoveries in 2004 (the "Tithonus poem" and a new, previously unknown fragment) and 2014 (fragments of nine poems: five already known but with new readings, four, including the "Brothers Poem", not previously known) have been reported in the media around the world. Style Sappho clearly worked within a well-developed tradition of Lesbian poetry, which had evolved its own poetic diction, meters, and conventions. Prior to Sappho and her contemporary Alcaeus, Lesbos was associated with poetry and music through the mythical Orpheus and Arion, and the seventh-century BC poet Terpander. Nonetheless, her work is innovative; it is some of the earliest Greek poetry to adopt the "lyric 'I'" – to write poetry adopting the viewpoint of a specific person, in contrast to the earlier epic poets Homer and Hesiod, who present themselves more as "conduits of divine inspiration". Her poetry explores individual identity and personal emotions – desire, jealousy, and love; it also adopts and reinterprets the existing imagery of epic poetry in exploring these themes. Sappho's poetry seems to have been composed for multiple occasions – including wedding songs, other ritual occasions, and more private situations – and probably encompassed both monodic and choral works. Sappho's poetry is known for its clear language and simple thoughts, sharply-drawn images, and use of direct quotation which brings a sense of immediacy. Unexpected word-play is a characteristic feature of her style. An example is from fragment 96: "now she stands out among Lydian women as after sunset the rose-fingered moon exceeds all stars", a variation of the Homeric epithet "rosy-fingered Dawn". Sappho's poetry often uses hyperbole, according to ancient critics "because of its charm". An example is found in fragment 111, where Sappho writes that "The groom approaches like Ares [...] Much bigger than a big man". Leslie Kurke groups Sappho with those archaic Greek poets from what has been called the "élite" ideological tradition, which valued luxury (habrosyne) and high birth. These elite poets tended to identify themselves with the worlds of Greek myths, gods, and heroes, as well as the wealthy East, especially Lydia. Thus in fragment 2 Sappho has Aphrodite "pour into golden cups nectar lavishly mingled with joys", while in the Tithonus poem she explicitly states that "I love the finer things [habrosyne]". According to Page DuBois, the language, as well as the content, of Sappho's poetry evokes an aristocratic sphere. She contrasts Sappho's "flowery,[...] adorned" style with the "austere, decorous, restrained" style embodied in the works of later classical authors such as Sophocles, Demosthenes, and Pindar. Traditional modern literary critics of Sappho's poetry have tended to see her poetry as a vivid and skilled but spontaneous and naive expression of emotion: typical of this view are the remarks of H. J. Rose that "Sappho wrote as she spoke, owing practically nothing to any literary influence," and that her verse displays "the charm of absolute naturalness." Against this essentially romantic view, one school of more recent critics argues that, on the contrary, Sappho's poetry displays and depends for its effect on a sophisticated deployment of the strategies of traditional Greek rhetorical genres – so that it seems spontaneous, whilst actually being very crafted. Sexuality The common term lesbian is an allusion to Sappho, originating from the name of the island of Lesbos, where she was born. However, she has not always been considered so. In classical Athenian comedy (from the Old Comedy of the fifth century to Menander in the late fourth and early third centuries BC), Sappho was caricatured as a promiscuous heterosexual woman, and it is not until the Hellenistic period that the first testimonia which explicitly discuss Sappho's homoeroticism are preserved. The earliest of these is a fragmentary biography written on papyrus in the late third or early second century BC, which states that Sappho was "accused by some of being irregular in her ways and a woman-lover". Denys Page comments that the phrase "by some" implies that even the full corpus of Sappho's poetry did not provide conclusive evidence of whether she described herself as having sex with women. These ancient authors do not appear to have believed that Sappho did, in fact, have sexual relationships with other women, and as late as the tenth century the Suda records that Sappho was "slanderously accused" of having sexual relationships with her "female pupils". Among modern scholars, Sappho's sexuality is still debated – André Lardinois has described it as the "Great Sappho Question". Early translators of Sappho sometimes heterosexualised her poetry. Ambrose Philips' 1711 translation of the Ode to Aphrodite portrayed the object of Sappho's desire as male, a reading that was followed by virtually every other translator of the poem until the twentieth century, while in 1781 Alessandro Verri interpreted fragment 31 as being about Sappho's love for Phaon. Friedrich Gottlieb Welcker argued that Sappho's feelings for other women were "entirely idealistic and non-sensual", while Karl Otfried Müller wrote that fragment 31 described "nothing but a friendly affection": Glenn Most comments that "one wonders what language Sappho would have used to describe her feelings if they had been ones of sexual excitement", if this theory were correct. By 1970, it would be argued that the same poem contained "proof positive of [Sappho's] lesbianism". Today, it is generally accepted that Sappho's poetry portrays homoerotic feelings: as Sandra Boehringer puts it, her works "clearly celebrate eros between women". Toward the end of the twentieth century, though, some scholars began to reject the question of whether or not Sappho was a lesbian – Glenn Most wrote that Sappho herself "would have had no idea what people mean when they call her nowadays a homosexual", André Lardinois stated that it is "nonsensical" to ask whether Sappho was a lesbian, and Page duBois calls the question a "particularly obfuscating debate". One of the major focuses of scholars studying Sappho has been to attempt to determine the cultural context in which Sappho's poems were composed and performed. Various cultural contexts and social roles played by Sappho have been suggested, including teacher, cult-leader, and	is some of the earliest Greek poetry to adopt the "lyric 'I'" – to write poetry adopting the viewpoint of a specific person, in contrast to the earlier epic poets Homer and Hesiod, who present themselves more as "conduits of divine inspiration". Her poetry explores individual identity and personal emotions – desire, jealousy, and love; it also adopts and reinterprets the existing imagery of epic poetry in exploring these themes. Sappho's poetry seems to have been composed for multiple occasions – including wedding songs, other ritual occasions, and more private situations – and probably encompassed both monodic and choral works. Sappho's poetry is known for its clear language and simple thoughts, sharply-drawn images, and use of direct quotation which brings a sense of immediacy. Unexpected word-play is a characteristic feature of her style. An example is from fragment 96: "now she stands out among Lydian women as after sunset the rose-fingered moon exceeds all stars", a variation of the Homeric epithet "rosy-fingered Dawn". Sappho's poetry often uses hyperbole, according to ancient critics "because of its charm". An example is found in fragment 111, where Sappho writes that "The groom approaches like Ares [...] Much bigger than a big man". Leslie Kurke groups Sappho with those archaic Greek poets from what has been called the "élite" ideological tradition, which valued luxury (habrosyne) and high birth. These elite poets tended to identify themselves with the worlds of Greek myths, gods, and heroes, as well as the wealthy East, especially Lydia. Thus in fragment 2 Sappho has Aphrodite "pour into golden cups nectar lavishly mingled with joys", while in the Tithonus poem she explicitly states that "I love the finer things [habrosyne]". According to Page DuBois, the language, as well as the content, of Sappho's poetry evokes an aristocratic sphere. She contrasts Sappho's "flowery,[...] adorned" style with the "austere, decorous, restrained" style embodied in the works of later classical authors such as Sophocles, Demosthenes, and Pindar. Traditional modern literary critics of Sappho's poetry have tended to see her poetry as a vivid and skilled but spontaneous and naive expression of emotion: typical of this view are the remarks of H. J. Rose that "Sappho wrote as she spoke, owing practically nothing to any literary influence," and that her verse displays "the charm of absolute naturalness." Against this essentially romantic view, one school of more recent critics argues that, on the contrary, Sappho's poetry displays and depends for its effect on a sophisticated deployment of the strategies of traditional Greek rhetorical genres – so that it seems spontaneous, whilst actually being very crafted. Sexuality The common term lesbian is an allusion to Sappho, originating from the name of the island of Lesbos, where she was born. However, she has not always been considered so. In classical Athenian comedy (from the Old Comedy of the fifth century to Menander in the late fourth and early third centuries BC), Sappho was caricatured as a promiscuous heterosexual woman, and it is not until the Hellenistic period that the first testimonia which explicitly discuss Sappho's homoeroticism are preserved. The earliest of these is a fragmentary biography written on papyrus in the late third or early second century BC, which states that Sappho was "accused by some of being irregular in her ways and a woman-lover". Denys Page comments that the phrase "by some" implies that even the full corpus of Sappho's poetry did not provide conclusive evidence of whether she described herself as having sex with women. These ancient authors do not appear to have believed that Sappho did, in fact, have sexual relationships with other women, and as late as the tenth century the Suda records that Sappho was "slanderously accused" of having sexual relationships with her "female pupils". Among modern scholars, Sappho's sexuality is still debated – André Lardinois has described it as the "Great Sappho Question". Early translators of Sappho sometimes heterosexualised her poetry. Ambrose Philips' 1711 translation of the Ode to Aphrodite portrayed the object of Sappho's desire as male, a reading that was followed by virtually every other translator of the poem until the twentieth century, while in 1781 Alessandro Verri interpreted fragment 31 as being about Sappho's love for Phaon. Friedrich Gottlieb Welcker argued that Sappho's feelings for other women were "entirely idealistic and non-sensual", while Karl Otfried Müller wrote that fragment 31 described "nothing but a friendly affection": Glenn Most comments that "one wonders what language Sappho would have used to describe her feelings if they had been ones of sexual excitement", if this theory were correct. By 1970, it would be argued that the same poem contained "proof positive of [Sappho's] lesbianism". Today, it is generally accepted that Sappho's poetry portrays homoerotic feelings: as Sandra Boehringer puts it, her works "clearly celebrate eros between women". Toward the end of the twentieth century, though, some scholars began to reject the question of whether or not Sappho was a lesbian – Glenn Most wrote that Sappho herself "would have had no idea what people mean when they call her nowadays a homosexual", André Lardinois stated that it is "nonsensical" to ask whether Sappho was a lesbian, and Page duBois calls the question a "particularly obfuscating debate". One of the major focuses of scholars studying Sappho has been to attempt to determine the cultural context in which Sappho's poems were composed and performed. Various cultural contexts and social roles played by Sappho have been suggested, including teacher, cult-leader, and poet performing for a circle of female friends. However, the performance contexts of many of Sappho's fragments are not easy to determine, and for many more than one possible context is conceivable. One longstanding suggestion of a social role for Sappho is that of "Sappho as schoolmistress". At the beginning of the twentieth century, the German classicist Ulrich von Wilamowitz-Moellendorff posited that Sappho was a sort of schoolteacher, to "explain away Sappho's passion for her 'girls and defend her from accusations of homosexuality. The view continues to be influential, both among scholars and the general public, though more recently the idea has been criticised by historians as anachronistic and has been rejected by several prominent classicists as unjustified by the evidence. In 1959, Denys Page, for example, stated that Sappho's extant fragments portray "the loves and jealousies, the pleasures and pains, of Sappho and her companions"; and he adds, "We have found, and shall find, no trace of any formal or official or professional relationship between them... no trace of Sappho the principal of an academy." David A. Campbell in 1967 judged that Sappho may have "presided over a literary coterie", but that "evidence for a formal appointment as priestess or teacher is hard to find". None of Sappho's own poetry mentions her teaching, and the earliest testimonium to support the idea of Sappho as a teacher comes from Ovid, six centuries after Sappho's lifetime. Despite these problems, many newer interpretations of Sappho's social role are still based on this idea. In these interpretations, Sappho was involved in the ritual education of girls, for instance as a trainer of choruses of girls. Even if Sappho did compose songs for training choruses of young girls, not all of her poems can be interpreted in this light, and despite scholars' best attempts to find one, Yatromanolakis argues that there is no single performance context to which all of Sappho's poems can be attributed. Parker argues that Sappho should be considered as part of a group of female friends for whom she would have performed, just as her contemporary Alcaeus is. Some of her poetry appears to have been composed for identifiable formal occasions, but many of her songs are about – and possibly were to be performed at – banquets. Legacy Ancient reputation In antiquity, Sappho's poetry was highly admired, and several ancient sources refer to her as the "tenth Muse". The earliest surviving poem to do so is a third-century BC epigram by Dioscorides, but poems are preserved in the Greek Anthology by Antipater of Sidon and attributed to Plato on the same theme. She was sometimes referred to as "The Poetess", just as Homer was "The Poet". The scholars of Alexandria included her in the canon of nine lyric poets. According to Aelian, the Athenian lawmaker and poet Solon asked to be taught a song by Sappho "so that I may learn it and then die". This story may well be apocryphal, especially as Ammianus Marcellinus tells a similar story about Socrates and a song of Stesichorus, but it is indicative of how highly Sappho's poetry was considered in the ancient world. Sappho's poetry also influenced other ancient authors. In Greek, the Hellenistic poet Nossis was described by Marilyn B. Skinner as an imitator of Sappho, and Kathryn Gutzwiller argues that Nossis explicitly positioned herself as an inheritor of Sappho's position as a woman poet. Beyond poetry, Plato cites Sappho in his Phaedrus, and Socrates' second speech on love in that dialogue appears to echo Sappho's descriptions of the physical effects of desire in fragment 31. In the first century BC, Catullus established the themes and metres of Sappho's poetry as a part of Latin literature, adopting the Sapphic stanza, believed in antiquity to have been invented by Sappho, giving his lover in his poetry the name "Lesbia" in reference to Sappho, and adapting and translating Sappho's 31st fragment in his poem 51. Other ancient poets wrote about Sappho's life. She was a popular character in ancient Athenian comedy, and at least six separate comedies called Sappho are known. The earliest known ancient comedy to take Sappho as its main subject was the early-fifth or late-fourth century BC Sappho by Ameipsias, though nothing is known of it apart from its name. Sappho was also a favourite subject in the visual arts, the most commonly depicted poet on
the time of the codification of the Talmud, where the name is always rendered "Simon bar Koziba" () or Bar Kozevah. Revolt Background Despite the devastation wrought by the Romans during the First Jewish–Roman War (66–73 CE), which left the population and countryside in ruins, a series of laws passed by Roman Emperors provided the incentive for the second rebellion. Based on the delineation of years in Eusebius' Chronicon (whose Latin translation is known as the Chronicle of Jerome) the Jewish revolt began under the Roman governor Tineius (Tynius) Rufus in the 16th year of Hadrian's reign, or what was equivalent to the 4th year of the 227th Olympiad. Hadrian sent an army to crush the resistance, but it faced a strong opponent, since Bar Kokhba, as the recognised leader of Israel, punished any Jew who refused to join his ranks. Two and a half years later, after the war had ended, the Roman emperor Hadrian barred Jews from entering Ælia Capitolina, the pagan city he had built on the ruins of Jewish Jerusalem. The name Aelia was derived from one of the emperor's names, Aelius. According to Philostorgius, this was done so that its former Jewish inhabitants "might not find in the name of the city a pretext for claiming it as their country." Overview The second Jewish rebellion took place 60 years after the first and established an independent state lasting three years. For many Jews of the time, this turn of events was heralded as the long hoped for Messianic Age. The Romans fared very poorly during the initial revolt facing a unified Jewish force, in contrast to the First Jewish-Roman War, where Flavius Josephus records three separate Jewish armies fighting each other for control of the Temple Mount during the three weeks after the Romans had breached Jerusalem's walls and were fighting their way to the center. Being outnumbered and taking heavy casualties, the Romans adopted a scorched earth policy which reduced and demoralised the Judean populace, slowly grinding away at the will of the Judeans to sustain the war. During the final phase of the war, Bar Kokhba took up refuge in the fortress of Betar. The Romans eventually captured it after laying siege to the city. The Jerusalem Talmud makes several claims considered as non-historical by modern scholarship. One such claim is that the duration of the siege was of three and half years, although the war itself lasted, according to the same author, two and half years. Another part of the Talmudic narrative is that the Romans killed all the defenders except for one Jewish youth, Simeon ben Gamliel, whose life was spared. According to Cassius Dio, 580,000 Jews were killed in overall war operations across the country, and some 50 fortified towns and 985 villages razed to the ground, while the number of those who perished by famine, disease and fire was past finding out. Outcome and aftermath So costly was the Roman victory, that the Emperor Hadrian, when reporting to the Roman Senate, did not see fit to begin with the customary greeting "If you and your children are healthy, it is well; I and the legions are healthy." In the aftermath of the war, Hadrian consolidated the older political units of Judaea, Galilee and Samaria into the new province of Syria Palaestina, which is commonly interpreted as an attempt to complete the disassociation with Judaea. Archaeological findings Over the past few decades, new information about the revolt has come to light, from the discovery of several collections of letters, some possibly by Bar Kokhba himself, in the	Bar Koseva that is implied by this change of name was carried on by later rabbinic scholarship at least to the time of the codification of the Talmud, where the name is always rendered "Simon bar Koziba" () or Bar Kozevah. Revolt Background Despite the devastation wrought by the Romans during the First Jewish–Roman War (66–73 CE), which left the population and countryside in ruins, a series of laws passed by Roman Emperors provided the incentive for the second rebellion. Based on the delineation of years in Eusebius' Chronicon (whose Latin translation is known as the Chronicle of Jerome) the Jewish revolt began under the Roman governor Tineius (Tynius) Rufus in the 16th year of Hadrian's reign, or what was equivalent to the 4th year of the 227th Olympiad. Hadrian sent an army to crush the resistance, but it faced a strong opponent, since Bar Kokhba, as the recognised leader of Israel, punished any Jew who refused to join his ranks. Two and a half years later, after the war had ended, the Roman emperor Hadrian barred Jews from entering Ælia Capitolina, the pagan city he had built on the ruins of Jewish Jerusalem. The name Aelia was derived from one of the emperor's names, Aelius. According to Philostorgius, this was done so that its former Jewish inhabitants "might not find in the name of the city a pretext for claiming it as their country." Overview The second Jewish rebellion took place 60 years after the first and established an independent state lasting three years. For many Jews of the time, this turn of events was heralded as the long hoped for Messianic Age. The Romans fared very poorly during the initial revolt facing a unified Jewish force, in contrast to the First Jewish-Roman War, where Flavius Josephus records three separate Jewish armies fighting each other for control of the Temple Mount during the three weeks after the Romans had breached Jerusalem's walls and were fighting their way to the center. Being outnumbered and taking heavy casualties, the Romans adopted a scorched earth policy which reduced and demoralised the Judean populace, slowly grinding away at the will of the Judeans to sustain the war. During the final phase of the war, Bar Kokhba took up refuge in the fortress of Betar. The Romans eventually captured it after laying siege to the city. The Jerusalem Talmud makes several claims considered as non-historical by modern scholarship. One such claim is that the duration of the siege was of three and half years, although the war itself lasted, according to the same author, two and half years. Another part of the Talmudic narrative is that the Romans killed all the defenders except for one Jewish youth, Simeon ben Gamliel, whose life was spared. According to Cassius Dio, 580,000 Jews were killed in overall war operations across the country, and some 50 fortified towns and 985 villages razed to the ground, while the number of those who perished by famine, disease and fire was past finding out. Outcome and aftermath So costly was the Roman victory, that the Emperor Hadrian, when reporting to the Roman Senate, did not see fit to begin with the customary greeting "If you and your children are healthy, it is well; I and the legions are healthy." In the aftermath of the war, Hadrian consolidated the older political units of Judaea, Galilee and Samaria into the new province of Syria Palaestina, which is commonly interpreted as an attempt to complete the disassociation with Judaea. Archaeological findings Over the past few decades, new information about the revolt has come to light, from the discovery of several collections of letters, some possibly by Bar Kokhba himself, in the Cave of Letters overlooking the Dead Sea. These letters can now be seen at the Israel Museum. Ideology and language According to Israeli archaeologist Yigael Yadin, Bar Kokhba tried to revive Hebrew and make Hebrew the official language of the Jews as part of his messianic ideology. In A Roadmap to the Heavens: An Anthropological Study of Hegemony among Priests, Sages, and Laymen (Judaism and Jewish Life) by Sigalit Ben-Zion (page 155), Yadin remarked: "it seems that this change came as a result of the order that was given by Bar Kokhba, who wanted to revive the Hebrew language and make it the official language of the state." Character Talmud Simon bar Kokhba is portrayed in rabbinic literature as being somewhat irrational and irascible in conduct. The Talmud says that he presided over an army of Jewish insurgents numbering some 200,000, but had compelled its young recruits to prove their valor by each man chopping off one of his own fingers. The Sages of Israel complained to him why he marred the people of Israel with such blemishes. Whenever he would go forth into battle, he was reported as saying: "O Master of the universe, there is no need for you to assist us [against our enemies], but do not embarrass us either!" It is also said of him that he killed his maternal uncle, Rabbi Elazar Hamudaʻi, after suspecting him of collaborating with the enemy, thereby forfeiting Divine protection, which led to the destruction of Betar in which Bar Kokhba himself also perished. Hadrian is thought to have personally supervised the closing military operations in the siege against Betar. When the Roman army eventually took the city, soldiers carried Bar Kokhba's severed head to Hadrian, and when Hadrian asked who it was that killed him, a Samaritan replied that he had killed him. When Hadrian requested that they bring the severed head (Latin:protome) of the slain victim close to him that he might see it, Hadrian observed that a serpent was wrapped around the head. Hadrian then replied: "Had it not been for God who killed him, who would have been able to kill him!?" Eusebius Bar Kokhba was a ruthless leader, punishing any Jew who refused to join his ranks. According to Eusebius' Chronicon, he severely
mental disorders, such as panic disorder, obsessive–compulsive disorder, or substance use disorder. These are separate disorders that require treatment. When comorbid with schizophrenia, substance use disorder and antisocial personality disorder both increase the risk for violence. Comorbid substance use disorder also increases risk for suicide. Sleep disorders often co-occur with schizophrenia, and may be an early sign of relapse. Sleep disorders are linked with positive symptoms such as disorganized thinking and can adversely affect cortical plasticity and cognition. The consolidation of memories is disrupted in sleep disorders. They are associated with severity of illness, a poor prognosis, and poor quality of life. Sleep onset and maintenance insomnia is a common symptom, regardless of whether treatment has been received or not. Genetic variations have been found associated with these conditions involving the circadian rhythm, dopamine and histamine metabolism, and signal transduction. Limited positive evidence has been found for the use of acupuncture as an add-on. Differential diagnosis To make a diagnosis of schizophrenia other possible causes of psychosis need to be excluded. Psychotic symptoms lasting less than a month may be diagnosed as brief psychotic disorder, or as schizophreniform disorder. Psychosis is noted in Other specified schizophrenia spectrum and other psychotic disorders as a DSM-5 category. Schizoaffective disorder is diagnosed if symptoms of mood disorder are substantially present alongside psychotic symptoms. Psychosis that results from a general medical condition or substance is termed secondary psychosis. Psychotic symptoms may be present in several other conditions, including bipolar disorder, borderline personality disorder, substance intoxication, substance-induced psychosis, and a number of drug withdrawal syndromes. Non-bizarre delusions are also present in delusional disorder, and social withdrawal in social anxiety disorder, avoidant personality disorder and schizotypal personality disorder. Schizotypal personality disorder has symptoms that are similar but less severe than those of schizophrenia. Schizophrenia occurs along with obsessive–compulsive disorder (OCD) considerably more often than could be explained by chance, although it can be difficult to distinguish obsessions that occur in OCD from the delusions of schizophrenia. There can be considerable overlap with the symptoms of post-traumatic stress disorder. A more general medical and neurological examination may be needed to rule out medical illnesses which may rarely produce psychotic schizophrenia-like symptoms, such as metabolic disturbance, systemic infection, syphilis, HIV-associated neurocognitive disorder, epilepsy, limbic encephalitis, and brain lesions. Stroke, multiple sclerosis, hyperthyroidism, hypothyroidism, and dementias such as Alzheimer's disease, Huntington's disease, frontotemporal dementia, and the Lewy body dementias may also be associated with schizophrenia-like psychotic symptoms. It may be necessary to rule out a delirium, which can be distinguished by visual hallucinations, acute onset and fluctuating level of consciousness, and indicates an underlying medical illness. Investigations are not generally repeated for relapse unless there is a specific medical indication or possible adverse effects from antipsychotic medication. In children hallucinations must be separated from typical childhood fantasies. It is difficult to distinguish childhood schizophrenia from autism. Prevention Prevention of schizophrenia is difficult as there are no reliable markers for the later development of the disorder. There is tentative though inconclusive evidence for the effectiveness of early intervention to prevent schizophrenia in the prodrome phase. There is some evidence that early intervention in those with first-episode psychosis may improve short-term outcomes, but there is little benefit from these measures after five years. Cognitive behavioral therapy may reduce the risk of psychosis in those at high risk after a year and is recommended in this group, by the National Institute for Health and Care Excellence (NICE). Another preventive measure is to avoid drugs that have been associated with development of the disorder, including cannabis, cocaine, and amphetamines. Antipsychotics are prescribed following a first-episode psychosis, and following remission a preventive maintenance use is continued to avoid relapse. However, it is recognised that some people do recover following a single episode and that long-term use of antipsychotics will not be needed but there is no way of identifying this group. Management The primary treatment of schizophrenia is the use of antipsychotic medications, often in combination with psychosocial interventions and social supports. Community support services including drop-in centers, visits by members of a community mental health team, supported employment, and support groups are common. The time between the onset of psychotic symptoms to being given treatment – the duration of untreated psychosis (DUP) – is associated with a poorer outcome in both the short term and the long term. Voluntary or involuntary admittance to hospital may be imposed by doctors and courts who deem a person to be having a severe episode. In the UK, large mental hospitals termed asylums began to be closed down in the 1950s with the advent of antipsychotics, and with an awareness of the negative impact of long-term hospital stays on recovery. This process was known as deinstitutionalization, and community and supportive services were developed in order to support this change. Many other countries followed suit with the US starting in the 60s. There still remain a smaller group of people who doctors and courts do not agree to discharge. In some countries that lack the necessary supportive and social services, long-term hospital stays are more usual. Medication The first-line treatment for schizophrenia is an antipsychotic. The first-generation antipsychotics, now called typical antipsychotics, are dopamine antagonists that block D2 receptors, and affect the neurotransmission of dopamine. Those brought out later, the second-generation antipsychotics known as atypical antipsychotics, can also have effect on another neurotransmitter, serotonin. Antipsychotics can reduce the symptoms of anxiety within hours of their use but for other symptoms they may take several days or weeks to reach their full effect. They have little effect on negative and cognitive symptoms, which may be helped by additional psychotherapies and medications. There is no single antipsychotic suitable for first-line treatment for everyone, as responses and tolerances vary between people. Stopping medication may be considered after a single psychotic episode where there has been a full recovery with no symptoms for twelve months. Repeated relapses worsen the long-term outlook and the risk of relapse following a second episode is high, and long-term treatment is usually recommended. Tobacco smoking increases the metabolism of some antipsychotics, by strongly activitating CYP1A2, the enzyme that breaks them down, and a significant difference is found in these levels between smokers and non-smokers. It is recommended that the dosage for those smokers on clozapine be increased by 50%, and for those on olanzapine by 30%. The result of stopping smoking can lead to an increased concentration of the antipsychotic that may result in toxicity, so that monitoring of effects would need to take place with a view to decreasing the dosage; many symptoms may be noticeably worsened, and extreme fatigue, and seizures are also possible with a risk of relapse. Likewise those who resume smoking may need their dosages adjusted accordingly. The altering effects are due to compounds in tobacco smoke and not to nicotine; the use of nicotine replacement therapy therefore has the equivalent effect of stopping smoking and monitoring would still be needed. About 30 to 50 percent of people with schizophrenia fail to accept that they have an illness or comply with their recommended treatment. For those who are unwilling or unable to take medication regularly, long-acting injections of antipsychotics may be used, which reduce the risk of relapse to a greater degree than oral medications. When used in combination with psychosocial interventions, they may improve long-term adherence to treatment. Research findings suggested that other neurotransmission systems, including serotonin, glutamate, GABA, and acetycholine, were implicated in the development of schizophrenia, and that a more inclusive medication was needed. A new first-in-class antipsychotic that targets multiple neurotransmitter systems called lumateperone (ITI-007), was trialed and approved by the FDA in December 2019 for the treatment of schizophrenia in adults. Lumateperone is a small molecule agent that shows improved safety, and tolerance. It interacts with dopamine, serotonin, and glutamate in a complex, uniquely selective manner, and is seen to improve negative and positive symptoms, and social functioning. Lumateperone was also found to reduce potential metabolic dysfunction, have lower rates of movement disorders, and have lower cardiovascular side effects such as a fast heart rate. Side effects Typical antipsychotics are associated with a higher rate of movement disorders including akathisia. Some atypicals are associated with considerable weight gain, diabetes and the risk of metabolic syndrome. Risperidone (atypical) has a similar rate of extrapyramidal symptoms to haloperidol (typical). A rare but potentially lethal condition of neuroleptic malignant syndrome (NMS) has been associated with the use of antipsychotics. Through its early recognition, and timely intervention rates have declined. However, an awareness of the syndrome is advised to enable intervention. Another less rare condition of tardive dyskinesia can occur due to long-term use of antipsychotics, developing after many months or years of use. It is more often reported with use of typical antipsychotics. Clozapine is associated with side effects that include weight gain, tiredness, and hypersalivation. More serious adverse effects include seizures, NMS, neutropenia, and agranulocytosis (lowered white blood cell count) and its use needs careful monitoring. Studies have found that antipsychotic treatment following NMS and neutropenia may sometimes be successfully rechallenged (restarted) with clozapine. Clozapine is also associated with thromboembolism (including pulmonary embolism), myocarditis, and cardiomyopathy. A systematic review of clozapine-associated pulmonary embolism indicates that this adverse effect can often be fatal, and that it has an early onset, and is dose-dependent. The findings advised the consideration of using a prevention therapy for venous thromboembolism after starting treatment with clozapine, and continuing this for six months. Constipation is three times more likely to occur with the use of clozapine, and severe cases can lead to ileus and bowel ischemia resulting in many fatalities. However, the risk of serious adverse effects from clozapine is low, and there are the beneficial effects to be gained of a reduced risk of suicide, and aggression. Typical antipsychotics and atypical risperidone can have a side effect of sexual dysfunction. Clozapine, olanzapine, and quetiapine are associated with beneficial effects on sexual functioning helped by various psychotherapies. Unwanted side effects cause people to stop treatment, resulting in relapses. Treatment resistant schizophrenia About half of those with schizophrenia will respond favourably to antipsychotics, and have a good return of functioning. However, positive symptoms persist in up to a third of people. Following two trials of different antipsychotics over six weeks, that also prove ineffective, they will be classed as having treatment resistant schizophrenia (TRS), and clozapine will be offered. Clozapine is of benefit to around half of this group although it has the potentially serious side effect of agranulocytosis (lowered white blood cell count) in less than 4% of people. Between 12 and 20 per cent will not respond to clozapine and this group is said to have ultra treatment resistant schizophrenia. ECT may be offered to treat TRS as an add-on therapy, and is shown to sometimes be of benefit. A review concluded that this use only has an effect on medium-term TRS and that there is not enough evidence to support its use other than for this group. TRS is often accompanied by a low quality of life, and greater social dysfunction. TRS may be the result of inadequate rather than inefficient treatment; it also may be a false label due to medication not being taken regularly, or at all. About 16 per cent of people who had initially been responsive to treatment later develop resistance. This could relate to the length of time on APs, with treatment becoming less responsive. This finding also supports the involvement of dopamine in the development of schizophrenia. Studies suggest that TRS may be a more heritable form. TRS may be evident from first episode psychosis, or from a relapse. It can vary in its intensity and response to other therapies. This variation is seen to possibly indicate an underlying neurobiology such as dopamine supersensitivity (DSS), glutamate or serotonin dysfunction, inflammation and oxidative stress. Studies have found that dopamine supersensitivity is found in up to 70% of those with TRS. The variation has led to the suggestion that treatment responsive and treatment resistant schizophrenia be considered as two different subtypes. It is further suggested that if the subtypes could be distinguished at an early stage significant implications could follow for treatment considerations, and for research. Neuroimaging studies have found a significant decrease in the volume of grey matter in those with TRS with no such change seen in those who are treatment responsive. In those with ultra treatment resistance the decrease in grey matter volume was larger. A link has been made between the gut microbiota and the development of TRS. The most prevalent cause put forward for TRS is that of mutation in the genes responsible for drug effectiveness. These include liver enzyme genes that control the availability of a drug to brain targets, and genes responsible for the structure and function of these targets. In the colon the bacteria encode a hundred times more genes than exist in the human genome. Only a fraction of ingested drugs reach the colon, having been already exposed to small intestinal bacteria, and absorbed in the portal circulation. This small fraction is then subject to the metabolic action of many communities of bacteria. Activation of the drug depends on the composition and enzymes of the bacteria and of the specifics of the drug, and therefore a great deal of individual variation can affect both the usefulness of the drug and its tolerability. It is suggested that parenteral administration of antipsychotics would bypass the gut and be more successful in overcoming TRS. The composition of gut microbiota is variable between individuals, but they are seen to remain stable. However, phyla can change in response to many factors including ageing, diet, substance use, and medications – especially antibiotics, laxatives, and antipsychotics. In FEP, schizophrenia has been linked to significant changes in the gut microbiota that can predict response to treatment. Psychosocial interventions A number of psychosocial interventions that include several types of psychotherapy may be useful in the treatment of schizophrenia such as: family therapy, group therapy, cognitive remediation therapy (CRT), cognitive behavioral therapy (CBT), and metacognitive training. Skills training, and help with substance use, and weight management – often needed as a side effect of an antipsychotic – are also offered. In the US, interventions for first episode psychosis have been brought together in an overall approach known as coordinated speciality care (CSC) and also includes support for education. In the UK care across all phases is a similar approach that covers many of the treatment guidelines recommended. The aim is to reduce the number of relapses and stays in hospital. Other support services for education, employment, and housing are usually offered. For people suffering from severe schizophrenia, and discharged from a stay in hospital, these services are often brought together in an integrated approach to offer support in the community away from the hospital setting. In addition to medicine management, housing, and finances, assistance is given for more routine matters such as help with shopping and using public transport. This approach is known as assertive community treatment (ACT) and has been shown to achieve positive results in symptoms, social functioning and quality of life. Another more intense approach is known as intensive care management (ICM). ICM is a stage further than ACT and emphasises support of high intensity in smaller caseloads, (less than twenty). This approach is to provide long-term care in the community. Studies show that ICM improves many of the relevant outcomes including social functioning. Some studies have shown little evidence for the effectiveness of CBT in either reducing symptoms or preventing relapse. However, other studies have found that CBT does improve overall psychotic symptoms (when in use with medication) and it has been recommended in Canada, but has been seen to have no effect on social function, relapse, or quality of life. In the UK it is recommended as an add-on therapy in the treatment of schizophrenia; one study questions its use in treatment resistant schizophrenia. Arts therapies are seen to improve negative symptoms in some people, and are recommended by NICE in the UK. This approach is criticised as having not been well-researched, and arts therapies are not recommended in Australian guidelines for example. Peer support, in which people with personal experience of schizophrenia, provide help to each other, is of unclear benefit. Other Exercise including aerobic exercise has been shown to improve positive and negative symptoms, cognition, working memory, and improve quality of life. Exercise has also been shown to increase the volume of the hippocampus in those with schizophrenia. A decrease in hippocampal volume is one of the factors linked to the development of the disease. However, there still remains the problem of increasing motivation for, and maintaining participation in physical activity. Supervised sessions are recommended. In the UK healthy eating advice is offered alongside exercise programs. An inadequate diet is often found in schizophrenia, and associated vitamin deficiencies including those of folate, and vitamin D are linked to the risk factors for the development of schizophrenia and for early death including heart disease. Those with schizophrenia possibly have the worst diet of all the mental disorders. Lower levels of folate and vitamin D have been noted as significantly lower in first episode psychosis. The use of supplemental folate is recommended. A zinc deficiency has also been noted. Vitamin B12 is also often deficient and this is linked to worse symptoms. Supplementation with B vitamins has been shown to significantly improve symptoms, and to put in reverse some of the cognitive deficits. It is also suggested that the noted dysfunction in gut microbiota might benefit from the use of probiotics. Violence Most people with schizophrenia are not aggressive, and are more likely to be victims of violence rather than perpetrators. Schizophrenic people are commonly exploited and victimized by violent crime as part of a broader dynamic of social exclusion. People diagnosed with schizophrenia are also subject to forced drug injections, seclusion, and restraint at high rates. The risk of violence by schizophrenic people is small. There are minor subgroups where the risk is high. This risk is usually associated with a comorbid disorder such as a substance use disorder – in particular alcohol, or with antisocial personality disorder. Substance use disorder is strongly linked, and other risk factors are linked to deficits in cognition and social cognition including facial perception and insight that are in part included in theory of mind impairments. Poor cognitive functioning, decision-making, and facial perception may contribute to making a wrong judgement of a situation that could result in an inappropriate response such as violence. These associated risk factors are also present in antisocial personality disorder which when present as a comorbid disorder greatly increases the risk of violence. A review in 2012 showed that 6 percent of people convicted of homicide in Western countries had been diagnosed as schizophrenic. Another wider review put the figure at between 5 and 20 percent. People convicted of homicide were found more likely to have committed it during first episode psychosis, and this accounted for 38.5 percent (of the 5 to 20 percent of perpetrators who were diagnosed schizophrenic, so 2 to 7.7 percent of perpetrators total). The association between schizophrenia and violence is complex. Homicide is linked with young age, male sex, a history of violence, and a stressful event in the preceding year. Clinical risk factors are severe untreated psychotic symptoms – untreated due to either not taking medication or to the condition being treatment resistant. A comorbid substance use disorder or an antisocial personality disorder increases the risk for homicidal behaviour by 8-fold, in contrast to the 2-fold risk in those without the comorbid disorders. Rates of homicide linked to psychosis are similar to those linked to substance misuse, and parallel the overall rate in a region. What role schizophrenia has on violence independent of substance misuse is controversial, but certain aspects of individual histories or mental states may be factors. Hostility is anger felt and directed at a person or group and has related dimensions of impulsiveness and aggression. When this impulsive aggression is evident in schizophrenia neuroimaging has suggested the malfunctioning of a neural circuit that modulates hostile thoughts and behaviours that are linked with negative emotions in social interactions. This circuit includes the amygdala, striatum, prefrontal cortex, anterior cingulate cortex, insula, and hippocampus. Hostility has been reported during acute psychosis, and following hospital discharge. There is a known association between low cholesterol levels, and impulsivity, and violence. A review finds that people with schizophrenia, and lower cholesterol levels are four times more likely to instigate violent acts. This association is also linked to the increased number of suicides in schizophrenia. It is suggested that cholesterol levels could serve as a biomarker for violent and suicidal tendencies. A review found that just under 10 percent of those with schizophrenia showed violent behaviour compared to 1.6 percent of the general population. An excessive risk of violence is associated with drugs or alcohol and increases the risk by as much as 4-fold. Violence often leads to imprisonment. Clozapine is an effective medication that can be used in penal settings such as prisons. However, a condition of benign ethnic neutropenia in many African-Americans excludes them from the use of clozapine, the most effective medication. Cognitive deficits are recognised as playing an important part in the origin and maintenance of aggression, and cognitive remediation therapy may therefore help to prevent the risk of violence in schizophrenia. Prognosis Schizophrenia has great human and economic costs. It results in a decreased life expectancy of 20 years. This is primarily because of its association with obesity, poor diet, a sedentary lifestyle, and smoking, with an increased rate of suicide playing a lesser role. Side effects of antipsychotics may also increase the risk. These differences in life expectancy increased between the 1970s and 1990s. An Australian study puts the rate of early death at 25 years, and views the main cause to be related to heart disease. Several studies indicate that almost 40% of those with schizophrenia die from complications of cardiovascular disease including heart attacks, and sudden cardiac death which is seen to be increasingly associated. An underlying factor of sudden cardiac death may be Brugada syndrome (BrS) – BrS mutations that overlap with those linked with schizophrenia are the calcium channel mutations. BrS may also be drug-induced from certain antipsychotics and antidepressants. Primary polydipsia, or excessive fluid intake, is relatively common in people with chronic schizophrenia. This may lead to hyponatremia which can be life-threatening. Antipsychotics can lead to a dry mouth, but there are several other factors that may contribute to the disorder. It is suggested to lead to a reduction in life expectancy by 13 per cent. A study has suggested that real barriers to improving the mortality rate in schizophrenia are poverty, overlooking the symptoms of other illnesses, stress, stigma, and medication side effects, and that these need to be changed. Schizophrenia is a major cause of disability. In 2016 it was classed as the 12th most disabling condition. Approximately 75% of people with schizophrenia have ongoing disability with relapses and 16.7 million people globally are deemed to have moderate or severe disability from the condition. Some people do recover completely and others function well in society. Most people with schizophrenia live independently with community support. About 85% are unemployed. In people with a first episode of psychosis in schizophrenia a good long-term outcome occurs in 31%, an intermediate outcome in 42% and a poor outcome in 31%. Males are affected more often than females, and have a worse outcome. But according to some reports, there is no difference in prevalence. Outcomes for schizophrenia appear better in the developing than the developed world. These conclusions have been questioned. Social problems, such as long-term unemployment, poverty, homelessness, exploitation, stigmatization and victimization are common consequences, and lead to social exclusion. There is a higher than average suicide rate associated with schizophrenia estimated at around 5% to 6%, most often occurring in the period following onset or first hospital admission. Several times more (20 to 40%) attempt suicide at least once. There are a variety of risk factors, including male gender, depression, a high IQ, heavy smoking, and substance use. Repeated relapse is linked to an increased risk of suicidal behavior. The use of clozapine can reduce the risk of suicide and aggression. A strong association between schizophrenia and tobacco smoking has been shown in worldwide studies. Smoking is especially high in those diagnosed with schizophrenia, with estimates ranging from 80 to 90% being regular smokers, as compared to 20% of the general population. Those who smoke tend to smoke heavily, and additionally smoke cigarettes with high nicotine content. Some propose that this is in an effort to improve symptoms. Among people with schizophrenia use of cannabis is also common. It has been shown that schizophrenia leads to an increased risk of dementia. Epidemiology In 2017, the Global Burden of Disease Study estimated there were 1.1 million new cases, and in 2019 the World Health Organization (WHO) reported a total of 20 million cases globally. Schizophrenia affects around 0.3–0.7% of people at some point in their life. It occurs 1.4 times more frequently in males than females and typically appears earlier in men – the peak ages of onset are 25 years for males and 27 years for females. Onset in childhood, before the age of 13 can sometimes occur. Other reviews find no difference in the prevalence of schizophrenia between the sexes. A later onset can occur between the ages of 40 and 60, known as late onset, and also after 60 known as very late onset. Worldwide, schizophrenia is the most common psychotic disorder. The frequency of schizophrenia varies across the world, within countries, and at the local and neighborhood level. This variation has been estimated to be fivefold. It causes approximately one percent of worldwide disability adjusted life years and resulted in 17,000 deaths in 2015. In 2000, WHO found the percentage of people affected and the number of new cases that develop each year is roughly similar around the world, with age-standardized prevalence per 100,000 ranging from 343 in Africa to 544 in Japan and Oceania for men, and from 378 in Africa to 527 in Southeastern Europe for women. About 1.1% of adults have schizophrenia in the United States. However, in areas of conflict this figure can rise to between 4.0 and 6.5%. History Accounts of a schizophrenia-like syndrome are rare in records before the 19th century. The earliest cases detailed were reported in 1797, and 1809. Dementia praecox, meaning premature dementia was used by German psychiatrist Heinrich Schüle in 1886, and then in 1891 by Arnold Pick in a case report of hebephrenia. In 1893 Emil Kraepelin used the term in making a distinction, known as the Kraepelinian dichotomy, between the two psychoses – dementia praecox, and manic depression (now called bipolar disorder). Kraepelin believed that dementia praecox was probably caused by a systemic disease that affected many organs and nerves, affecting the brain after puberty in a final decisive cascade. It was thought to be an early form of dementia, a degenerative disease. When it became evident that the disorder was not degenerative it was renamed schizophrenia by Eugen Bleuler in 1908. The word schizophrenia translates as "splitting of the mind" and is Modern Latin from the Greek words schizein (σχίζειν, "to split") and phrēn, (φρήν, "mind") Its use was intended to describe the separation of function between personality, thinking, memory, and perception. The term schizophrenia used to be associated with split personality by the general population but that usage went into decline when split personality became known as a separate disorder, first as multiple identity disorder , and later as dissociative identity disorder. In 2002 in Japan the name was changed to integration disorder, and in 2012 in South Korea, the name was changed to attunement disorder. In the	distinction be made between a current condition of schizophrenia and its historical progress, to achieve a clearer overall characterization. A dimensional assessment has been included in DSM-5 covering eight dimensions of symptoms to be rated (using the Scale to Assess the Severity of Symptom Dimensions) – these include the five diagnostic criteria plus cognitive impairments, mania, and depression. This can add relevant information for the individual in regard to treatment, prognosis, and functional outcome; it also enables the response to treatment to be more accurately described. Two of the negative symptoms – avolition and diminished emotional expression – have been given more prominence in both manuals. Comorbidities Many people with schizophrenia may have one or more other mental disorders, such as panic disorder, obsessive–compulsive disorder, or substance use disorder. These are separate disorders that require treatment. When comorbid with schizophrenia, substance use disorder and antisocial personality disorder both increase the risk for violence. Comorbid substance use disorder also increases risk for suicide. Sleep disorders often co-occur with schizophrenia, and may be an early sign of relapse. Sleep disorders are linked with positive symptoms such as disorganized thinking and can adversely affect cortical plasticity and cognition. The consolidation of memories is disrupted in sleep disorders. They are associated with severity of illness, a poor prognosis, and poor quality of life. Sleep onset and maintenance insomnia is a common symptom, regardless of whether treatment has been received or not. Genetic variations have been found associated with these conditions involving the circadian rhythm, dopamine and histamine metabolism, and signal transduction. Limited positive evidence has been found for the use of acupuncture as an add-on. Differential diagnosis To make a diagnosis of schizophrenia other possible causes of psychosis need to be excluded. Psychotic symptoms lasting less than a month may be diagnosed as brief psychotic disorder, or as schizophreniform disorder. Psychosis is noted in Other specified schizophrenia spectrum and other psychotic disorders as a DSM-5 category. Schizoaffective disorder is diagnosed if symptoms of mood disorder are substantially present alongside psychotic symptoms. Psychosis that results from a general medical condition or substance is termed secondary psychosis. Psychotic symptoms may be present in several other conditions, including bipolar disorder, borderline personality disorder, substance intoxication, substance-induced psychosis, and a number of drug withdrawal syndromes. Non-bizarre delusions are also present in delusional disorder, and social withdrawal in social anxiety disorder, avoidant personality disorder and schizotypal personality disorder. Schizotypal personality disorder has symptoms that are similar but less severe than those of schizophrenia. Schizophrenia occurs along with obsessive–compulsive disorder (OCD) considerably more often than could be explained by chance, although it can be difficult to distinguish obsessions that occur in OCD from the delusions of schizophrenia. There can be considerable overlap with the symptoms of post-traumatic stress disorder. A more general medical and neurological examination may be needed to rule out medical illnesses which may rarely produce psychotic schizophrenia-like symptoms, such as metabolic disturbance, systemic infection, syphilis, HIV-associated neurocognitive disorder, epilepsy, limbic encephalitis, and brain lesions. Stroke, multiple sclerosis, hyperthyroidism, hypothyroidism, and dementias such as Alzheimer's disease, Huntington's disease, frontotemporal dementia, and the Lewy body dementias may also be associated with schizophrenia-like psychotic symptoms. It may be necessary to rule out a delirium, which can be distinguished by visual hallucinations, acute onset and fluctuating level of consciousness, and indicates an underlying medical illness. Investigations are not generally repeated for relapse unless there is a specific medical indication or possible adverse effects from antipsychotic medication. In children hallucinations must be separated from typical childhood fantasies. It is difficult to distinguish childhood schizophrenia from autism. Prevention Prevention of schizophrenia is difficult as there are no reliable markers for the later development of the disorder. There is tentative though inconclusive evidence for the effectiveness of early intervention to prevent schizophrenia in the prodrome phase. There is some evidence that early intervention in those with first-episode psychosis may improve short-term outcomes, but there is little benefit from these measures after five years. Cognitive behavioral therapy may reduce the risk of psychosis in those at high risk after a year and is recommended in this group, by the National Institute for Health and Care Excellence (NICE). Another preventive measure is to avoid drugs that have been associated with development of the disorder, including cannabis, cocaine, and amphetamines. Antipsychotics are prescribed following a first-episode psychosis, and following remission a preventive maintenance use is continued to avoid relapse. However, it is recognised that some people do recover following a single episode and that long-term use of antipsychotics will not be needed but there is no way of identifying this group. Management The primary treatment of schizophrenia is the use of antipsychotic medications, often in combination with psychosocial interventions and social supports. Community support services including drop-in centers, visits by members of a community mental health team, supported employment, and support groups are common. The time between the onset of psychotic symptoms to being given treatment – the duration of untreated psychosis (DUP) – is associated with a poorer outcome in both the short term and the long term. Voluntary or involuntary admittance to hospital may be imposed by doctors and courts who deem a person to be having a severe episode. In the UK, large mental hospitals termed asylums began to be closed down in the 1950s with the advent of antipsychotics, and with an awareness of the negative impact of long-term hospital stays on recovery. This process was known as deinstitutionalization, and community and supportive services were developed in order to support this change. Many other countries followed suit with the US starting in the 60s. There still remain a smaller group of people who doctors and courts do not agree to discharge. In some countries that lack the necessary supportive and social services, long-term hospital stays are more usual. Medication The first-line treatment for schizophrenia is an antipsychotic. The first-generation antipsychotics, now called typical antipsychotics, are dopamine antagonists that block D2 receptors, and affect the neurotransmission of dopamine. Those brought out later, the second-generation antipsychotics known as atypical antipsychotics, can also have effect on another neurotransmitter, serotonin. Antipsychotics can reduce the symptoms of anxiety within hours of their use but for other symptoms they may take several days or weeks to reach their full effect. They have little effect on negative and cognitive symptoms, which may be helped by additional psychotherapies and medications. There is no single antipsychotic suitable for first-line treatment for everyone, as responses and tolerances vary between people. Stopping medication may be considered after a single psychotic episode where there has been a full recovery with no symptoms for twelve months. Repeated relapses worsen the long-term outlook and the risk of relapse following a second episode is high, and long-term treatment is usually recommended. Tobacco smoking increases the metabolism of some antipsychotics, by strongly activitating CYP1A2, the enzyme that breaks them down, and a significant difference is found in these levels between smokers and non-smokers. It is recommended that the dosage for those smokers on clozapine be increased by 50%, and for those on olanzapine by 30%. The result of stopping smoking can lead to an increased concentration of the antipsychotic that may result in toxicity, so that monitoring of effects would need to take place with a view to decreasing the dosage; many symptoms may be noticeably worsened, and extreme fatigue, and seizures are also possible with a risk of relapse. Likewise those who resume smoking may need their dosages adjusted accordingly. The altering effects are due to compounds in tobacco smoke and not to nicotine; the use of nicotine replacement therapy therefore has the equivalent effect of stopping smoking and monitoring would still be needed. About 30 to 50 percent of people with schizophrenia fail to accept that they have an illness or comply with their recommended treatment. For those who are unwilling or unable to take medication regularly, long-acting injections of antipsychotics may be used, which reduce the risk of relapse to a greater degree than oral medications. When used in combination with psychosocial interventions, they may improve long-term adherence to treatment. Research findings suggested that other neurotransmission systems, including serotonin, glutamate, GABA, and acetycholine, were implicated in the development of schizophrenia, and that a more inclusive medication was needed. A new first-in-class antipsychotic that targets multiple neurotransmitter systems called lumateperone (ITI-007), was trialed and approved by the FDA in December 2019 for the treatment of schizophrenia in adults. Lumateperone is a small molecule agent that shows improved safety, and tolerance. It interacts with dopamine, serotonin, and glutamate in a complex, uniquely selective manner, and is seen to improve negative and positive symptoms, and social functioning. Lumateperone was also found to reduce potential metabolic dysfunction, have lower rates of movement disorders, and have lower cardiovascular side effects such as a fast heart rate. Side effects Typical antipsychotics are associated with a higher rate of movement disorders including akathisia. Some atypicals are associated with considerable weight gain, diabetes and the risk of metabolic syndrome. Risperidone (atypical) has a similar rate of extrapyramidal symptoms to haloperidol (typical). A rare but potentially lethal condition of neuroleptic malignant syndrome (NMS) has been associated with the use of antipsychotics. Through its early recognition, and timely intervention rates have declined. However, an awareness of the syndrome is advised to enable intervention. Another less rare condition of tardive dyskinesia can occur due to long-term use of antipsychotics, developing after many months or years of use. It is more often reported with use of typical antipsychotics. Clozapine is associated with side effects that include weight gain, tiredness, and hypersalivation. More serious adverse effects include seizures, NMS, neutropenia, and agranulocytosis (lowered white blood cell count) and its use needs careful monitoring. Studies have found that antipsychotic treatment following NMS and neutropenia may sometimes be successfully rechallenged (restarted) with clozapine. Clozapine is also associated with thromboembolism (including pulmonary embolism), myocarditis, and cardiomyopathy. A systematic review of clozapine-associated pulmonary embolism indicates that this adverse effect can often be fatal, and that it has an early onset, and is dose-dependent. The findings advised the consideration of using a prevention therapy for venous thromboembolism after starting treatment with clozapine, and continuing this for six months. Constipation is three times more likely to occur with the use of clozapine, and severe cases can lead to ileus and bowel ischemia resulting in many fatalities. However, the risk of serious adverse effects from clozapine is low, and there are the beneficial effects to be gained of a reduced risk of suicide, and aggression. Typical antipsychotics and atypical risperidone can have a side effect of sexual dysfunction. Clozapine, olanzapine, and quetiapine are associated with beneficial effects on sexual functioning helped by various psychotherapies. Unwanted side effects cause people to stop treatment, resulting in relapses. Treatment resistant schizophrenia About half of those with schizophrenia will respond favourably to antipsychotics, and have a good return of functioning. However, positive symptoms persist in up to a third of people. Following two trials of different antipsychotics over six weeks, that also prove ineffective, they will be classed as having treatment resistant schizophrenia (TRS), and clozapine will be offered. Clozapine is of benefit to around half of this group although it has the potentially serious side effect of agranulocytosis (lowered white blood cell count) in less than 4% of people. Between 12 and 20 per cent will not respond to clozapine and this group is said to have ultra treatment resistant schizophrenia. ECT may be offered to treat TRS as an add-on therapy, and is shown to sometimes be of benefit. A review concluded that this use only has an effect on medium-term TRS and that there is not enough evidence to support its use other than for this group. TRS is often accompanied by a low quality of life, and greater social dysfunction. TRS may be the result of inadequate rather than inefficient treatment; it also may be a false label due to medication not being taken regularly, or at all. About 16 per cent of people who had initially been responsive to treatment later develop resistance. This could relate to the length of time on APs, with treatment becoming less responsive. This finding also supports the involvement of dopamine in the development of schizophrenia. Studies suggest that TRS may be a more heritable form. TRS may be evident from first episode psychosis, or from a relapse. It can vary in its intensity and response to other therapies. This variation is seen to possibly indicate an underlying neurobiology such as dopamine supersensitivity (DSS), glutamate or serotonin dysfunction, inflammation and oxidative stress. Studies have found that dopamine supersensitivity is found in up to 70% of those with TRS. The variation has led to the suggestion that treatment responsive and treatment resistant schizophrenia be considered as two different subtypes. It is further suggested that if the subtypes could be distinguished at an early stage significant implications could follow for treatment considerations, and for research. Neuroimaging studies have found a significant decrease in the volume of grey matter in those with TRS with no such change seen in those who are treatment responsive. In those with ultra treatment resistance the decrease in grey matter volume was larger. A link has been made between the gut microbiota and the development of TRS. The most prevalent cause put forward for TRS is that of mutation in the genes responsible for drug effectiveness. These include liver enzyme genes that control the availability of a drug to brain targets, and genes responsible for the structure and function of these targets. In the colon the bacteria encode a hundred times more genes than exist in the human genome. Only a fraction of ingested drugs reach the colon, having been already exposed to small intestinal bacteria, and absorbed in the portal circulation. This small fraction is then subject to the metabolic action of many communities of bacteria. Activation of the drug depends on the composition and enzymes of the bacteria and of the specifics of the drug, and therefore a great deal of individual variation can affect both the usefulness of the drug and its tolerability. It is suggested that parenteral administration of antipsychotics would bypass the gut and be more successful in overcoming TRS. The composition of gut microbiota is variable between individuals, but they are seen to remain stable. However, phyla can change in response to many factors including ageing, diet, substance use, and medications – especially antibiotics, laxatives, and antipsychotics. In FEP, schizophrenia has been linked to significant changes in the gut microbiota that can predict response to treatment. Psychosocial interventions A number of psychosocial interventions that include several types of psychotherapy may be useful in the treatment of schizophrenia such as: family therapy, group therapy, cognitive remediation therapy (CRT), cognitive behavioral therapy (CBT), and metacognitive training. Skills training, and help with substance use, and weight management – often needed as a side effect of an antipsychotic – are also offered. In the US, interventions for first episode psychosis have been brought together in an overall approach known as coordinated speciality care (CSC) and also includes support for education. In the UK care across all phases is a similar approach that covers many of the treatment guidelines recommended. The aim is to reduce the number of relapses and stays in hospital. Other support services for education, employment, and housing are usually offered. For people suffering from severe schizophrenia, and discharged from a stay in hospital, these services are often brought together in an integrated approach to offer support in the community away from the hospital setting. In addition to medicine management, housing, and finances, assistance is given for more routine matters such as help with shopping and using public transport. This approach is known as assertive community treatment (ACT) and has been shown to achieve positive results in symptoms, social functioning and quality of life. Another more intense approach is known as intensive care management (ICM). ICM is a stage further than ACT and emphasises support of high intensity in smaller caseloads, (less than twenty). This approach is to provide long-term care in the community. Studies show that ICM improves many of the relevant outcomes including social functioning. Some studies have shown little evidence for the effectiveness of CBT in either reducing symptoms or preventing relapse. However, other studies have found that CBT does improve overall psychotic symptoms (when in use with medication) and it has been recommended in Canada, but has been seen to have no effect on social function, relapse, or quality of life. In the UK it is recommended as an add-on therapy in the treatment of schizophrenia; one study questions its use in treatment resistant schizophrenia. Arts therapies are seen to improve negative symptoms in some people, and are recommended by NICE in the UK. This approach is criticised as having not been well-researched, and arts therapies are not recommended in Australian guidelines for example. Peer support, in which people with personal experience of schizophrenia, provide help to each other, is of unclear benefit. Other Exercise including aerobic exercise has been shown to improve positive and negative symptoms, cognition, working memory, and improve quality of life. Exercise has also been shown to increase the volume of the hippocampus in those with schizophrenia. A decrease in hippocampal volume is one of the factors linked to the development of the disease. However, there still remains the problem of increasing motivation for, and maintaining participation in physical activity. Supervised sessions are recommended. In the UK healthy eating advice is offered alongside exercise programs. An inadequate diet is often found in schizophrenia, and associated vitamin deficiencies including those of folate, and vitamin D are linked to the risk factors for the development of schizophrenia and for early death including heart disease. Those with schizophrenia possibly have the worst diet of all the mental disorders. Lower levels of folate and vitamin D have been noted as significantly lower in first episode psychosis. The use of supplemental folate is recommended. A zinc deficiency has also been noted. Vitamin B12 is also often deficient and this is linked to worse symptoms. Supplementation with B vitamins has been shown to significantly improve symptoms, and to put in reverse some of the cognitive deficits. It is also suggested that the noted dysfunction in gut microbiota might benefit from the use of probiotics. Violence Most people with schizophrenia are not aggressive, and are more likely to be victims of violence rather than perpetrators. Schizophrenic people are commonly exploited and victimized by violent crime as part of a broader dynamic of social exclusion. People diagnosed with schizophrenia are also subject to forced drug injections, seclusion, and restraint at high rates. The risk of violence by schizophrenic people is small. There are minor subgroups where the risk is high. This risk is usually associated with a comorbid disorder such as a substance use disorder – in particular alcohol, or with antisocial personality disorder. Substance use disorder is strongly linked, and other risk factors are linked to deficits in cognition and social cognition including facial perception and insight that are in part included in theory of mind impairments. Poor cognitive functioning, decision-making, and facial perception may contribute to making a wrong judgement of a situation that could result in an inappropriate response such as violence. These associated risk factors are also present in antisocial personality disorder which when present as a comorbid disorder greatly increases the risk of violence. A review in 2012 showed that 6 percent of people convicted of homicide in Western countries had been diagnosed as schizophrenic. Another wider review put the figure at between 5 and 20 percent. People convicted of homicide were found more likely to have committed it during first episode psychosis, and this accounted for 38.5 percent (of the 5 to 20 percent of perpetrators who were diagnosed schizophrenic, so 2 to 7.7 percent of perpetrators total). The association between schizophrenia and violence is complex. Homicide is linked with young age, male sex, a history of violence, and a stressful event in the preceding year. Clinical risk factors are severe untreated psychotic symptoms – untreated due to either not taking medication or to the condition being treatment resistant. A comorbid substance use disorder or an antisocial personality disorder increases the risk for homicidal behaviour by 8-fold, in contrast to the 2-fold risk in those without the comorbid disorders. Rates of homicide linked to psychosis are similar to those linked to substance misuse, and parallel the overall rate in a region. What role schizophrenia has on violence independent of substance misuse is controversial, but certain aspects of individual histories or mental states may be factors. Hostility is anger felt and directed at a person or group and has related dimensions of impulsiveness and aggression. When this impulsive aggression is evident in schizophrenia neuroimaging has suggested the malfunctioning of a neural circuit that modulates hostile thoughts and behaviours that are linked with negative emotions in social interactions. This circuit includes the amygdala, striatum, prefrontal cortex, anterior cingulate cortex, insula, and hippocampus. Hostility has been reported during acute psychosis, and following hospital discharge. There is a known association between low cholesterol levels, and impulsivity, and violence. A review finds that people with schizophrenia, and lower cholesterol levels are four times more likely to instigate violent acts. This association is also linked to the increased number of suicides in schizophrenia. It is suggested that cholesterol levels could serve as a biomarker for violent and suicidal tendencies. A review found that just under 10 percent of those with schizophrenia showed violent behaviour compared to 1.6 percent of the general population. An excessive risk of violence is associated with drugs or alcohol and increases the risk by as much as 4-fold. Violence often leads to imprisonment. Clozapine is an effective medication that can be used in penal settings such as prisons. However, a condition of benign ethnic neutropenia in many African-Americans excludes them from the use of clozapine, the most effective medication. Cognitive deficits are recognised as playing an important part in the origin and maintenance of aggression, and cognitive remediation therapy may therefore help to prevent the risk of violence in schizophrenia. Prognosis Schizophrenia has great human and economic costs. It results in a decreased life expectancy of 20 years. This is primarily because of its association with obesity, poor diet, a sedentary lifestyle, and smoking, with an increased rate of suicide playing a lesser role. Side effects of antipsychotics may also increase the risk. These differences in life expectancy increased between the 1970s and 1990s. An Australian study puts the rate of early death at 25 years, and views the main cause to be related to heart disease. Several studies indicate that almost 40% of those with schizophrenia die from complications of cardiovascular disease including heart attacks, and sudden cardiac death which is seen to be increasingly associated. An underlying factor of sudden cardiac death may be Brugada syndrome (BrS) – BrS mutations that overlap with those linked with schizophrenia are the calcium channel mutations. BrS may also be drug-induced from certain antipsychotics and antidepressants. Primary polydipsia, or excessive fluid intake, is relatively common in people with chronic schizophrenia. This may lead to hyponatremia which can be life-threatening. Antipsychotics can lead to a dry mouth, but there are several other factors that may contribute to the disorder. It is suggested to lead to a reduction in life expectancy by 13 per cent. A study has suggested that real barriers to improving the mortality rate in schizophrenia are poverty, overlooking the symptoms of other illnesses, stress, stigma, and medication side effects, and that these need to be changed. Schizophrenia is a major cause of disability. In 2016 it was classed as the 12th most disabling condition. Approximately 75% of people with schizophrenia have ongoing disability with relapses and 16.7 million people globally are deemed to have moderate or severe disability from the condition. Some people do recover completely and others function well in society. Most people with schizophrenia live independently with community support. About 85% are unemployed. In people with a first episode of psychosis in schizophrenia a good long-term outcome occurs in 31%, an intermediate outcome in 42% and a poor outcome in 31%. Males are affected more often than females, and have a worse outcome. But according to some reports, there is no difference in prevalence. Outcomes for schizophrenia appear better in the developing than the developed world. These conclusions have been questioned. Social problems, such as long-term unemployment, poverty, homelessness, exploitation, stigmatization and victimization are common consequences, and lead to social exclusion. There is a higher than average suicide rate associated with schizophrenia estimated at around 5% to 6%, most often occurring in the period following onset or first hospital admission. Several times more (20 to 40%) attempt suicide at least once. There are a variety of risk factors, including male gender, depression, a high IQ, heavy smoking, and substance use. Repeated relapse is linked to an increased risk of suicidal behavior. The use of clozapine can reduce the risk of suicide and aggression. A strong association between schizophrenia and tobacco smoking has been shown in worldwide studies. Smoking is especially high in those diagnosed with schizophrenia, with estimates ranging from 80 to 90% being regular smokers, as compared to 20% of the general population. Those who smoke tend to smoke heavily, and additionally smoke cigarettes with high nicotine content. Some propose that this is in an effort to improve symptoms. Among people with schizophrenia use of cannabis is also common. It has been shown that schizophrenia leads to an increased risk of dementia. Epidemiology In 2017, the Global Burden of Disease Study estimated there were 1.1 million new cases, and in 2019 the World Health Organization (WHO) reported a total of 20 million cases globally. Schizophrenia affects around 0.3–0.7% of people at some point in their life. It occurs 1.4 times more frequently in males than females and typically appears earlier in men – the peak ages of onset are 25 years for males and 27 years for females. Onset in childhood, before the age of 13 can sometimes occur. Other reviews find no difference in the prevalence of schizophrenia between the sexes. A later onset can occur between the ages of 40 and 60, known as late onset, and also after 60 known as very late onset. Worldwide, schizophrenia is the most common psychotic disorder. The frequency of schizophrenia varies across the world, within countries, and at the local and neighborhood level. This variation has been estimated to be fivefold. It causes approximately one percent of worldwide disability adjusted life years and resulted in 17,000 deaths in 2015. In 2000, WHO found the percentage of people affected and the number of new cases that develop each year is roughly similar around the world, with age-standardized prevalence per 100,000 ranging from 343 in Africa to 544 in Japan and Oceania for men, and from 378 in Africa to 527 in Southeastern Europe for women. About 1.1% of adults have schizophrenia in the United States. However, in areas of conflict this figure can rise to between 4.0 and 6.5%. History Accounts of a schizophrenia-like syndrome are rare in records before the 19th century. The earliest cases detailed were reported in 1797, and 1809. Dementia praecox, meaning premature dementia was used by German psychiatrist Heinrich Schüle in 1886, and then in 1891 by Arnold Pick in a case report of hebephrenia. In 1893 Emil Kraepelin used the term in making a distinction, known as the Kraepelinian dichotomy, between the two psychoses – dementia praecox, and manic depression (now called bipolar disorder). Kraepelin believed that dementia praecox was probably caused by a systemic disease that affected many organs and nerves, affecting the brain after puberty in a final decisive cascade. It was thought to be an early form of dementia, a degenerative disease. When it became evident that the disorder was not degenerative it was renamed schizophrenia by Eugen Bleuler in 1908. The word schizophrenia translates as "splitting of the mind" and is Modern Latin from the Greek words schizein (σχίζειν, "to split") and phrēn, (φρήν, "mind") Its use was intended to describe the separation of function between personality, thinking, memory, and perception. The term schizophrenia used to be associated with split personality by the general population but that usage went into decline when split personality became known as a separate disorder, first as multiple identity disorder , and later as dissociative identity disorder. In 2002 in Japan the name was changed to integration disorder, and
the only entrant to the competition. In 1809 Germain began work. Legendre assisted by giving her equations, references, and current research. She submitted her paper early in the fall of 1811 and did not win the prize. The judging commission felt that "the true equations of the movement were not established", even though "the experiments presented ingenious results". Lagrange was able to use Germain's work to derive an equation that was "correct under special assumptions". Subsequent attempts for the Prize The contest was extended by two years, and Germain decided to try again for the prize. At first Legendre continued to offer support, but then he refused all help. Germain's anonymous 1813 submission was still littered with mathematical errors, especially involving double integrals, and it received only an honorable mention because "the fundamental base of the theory [of elastic surfaces] was not established". The contest was extended once more, and Germain began work on her third attempt. This time she consulted with Poisson. In 1814 he published his own work on elasticity and did not acknowledge Germain's help (although he had worked with her on the subject and, as a judge on the Academy commission, had had access to her work). Germain submitted her third paper, "", under her own name, and on 8 January 1816 she became the first woman to win a prize from the Paris Academy of Sciences. She did not appear at the ceremony to receive her award. Although Germain had at last been awarded the , the Academy was still not fully satisfied. Germain had derived the correct differential equation (a special case of the Kirchhoff–Love equation), but her method did not predict experimental results with great accuracy, as she had relied on an incorrect equation from Euler, which led to incorrect boundary conditions. Here is Germain's final equation for the vibration of a plane lamina: where N2 is a constant. After winning the Academy contest, she was still not able to attend its sessions because of the Academy's tradition of excluding women other than the wives of members. Seven years later this situation was transformed, when she made friends with Joseph Fourier, a secretary of the Academy, who obtained tickets to the sessions for her. Later work in elasticity Germain published her prize-winning essay at her own expense in 1821, mostly because she wanted to present her work in opposition to that of Poisson. In the essay she pointed out some of the errors in her method. In 1826 she submitted a revised version of her 1821 essay to the Academy. According to Andrea Del Centina, the revision included attempts to clarify her work by "introducing certain simplifying hypotheses". This put the Academy in an awkward position, as they felt the paper to be "inadequate and trivial", but they did not want to "treat her as a professional colleague, as they would any man, by simply rejecting the work". So Augustin-Louis Cauchy, who had been appointed to review her work, recommended her to publish it, and she followed his advice. One further work of Germain's on elasticity was published posthumously in 1831, her "". She used the mean curvature in her research (see Honors in number theory). Later work in number theory Renewed interest Germain's best work was in number theory, and her most significant contribution to number theory dealt with Fermat's Last Theorem. In 1815, after the elasticity contest, the Academy offered a prize for a proof of Fermat's Last Theorem. It reawakened Germain's interest in number theory, and she wrote to Gauss again after ten years of no correspondence. In the letter, Germain said that number theory was her preferred field and that it was in her mind all the time she was studying elasticity. She outlined a strategy for a general proof of Fermat's Last Theorem, including a proof for a special case. Germain's letter to Gauss contained her substantial progress toward a proof. She asked Gauss whether her approach to the theorem was worth pursuing. Gauss never answered. Her work on Fermat's Last Theorem Fermat's Last Theorem can be divided into two cases. Case 1 involves all powers p that do not divide any of x, y, or z. Case 2 includes all p that divide at least one of x, y, or z. Germain proposed the following, commonly called "Sophie Germain's theorem": Let p be an odd prime. If there exists an auxiliary prime P = 2Np + 1 (N is any positive integer not divisible by 3) such that: if xp + yp + zp ≡ 0 (mod P), then P divides xyz, and p is not a p-th power residue (mod P). Then the first case of Fermat's Last Theorem holds true for p. Germain used this result to prove the first case of Fermat's Last Theorem for all odd primes p < 100, but according to Andrea Del Centina, "she had actually shown that it holds for every exponent p < 197". L. E. Dickson later used Germain's theorem to prove the first case of Fermat's Last Theorem for odd primes less than 1700. In an unpublished manuscript titled , Germain showed that any counterexamples to Fermat's theorem for p > 5 must be numbers "whose size frightens the imagination", around 40 digits long. Germain did not publish this work. Her brilliant theorem is known only because of the footnote in Legendre's treatise on number theory, where he used it to prove Fermat's Last Theorem for p = 5 (see Correspondence with Legendre). Germain also proved or nearly proved several results that were attributed to Lagrange or were rediscovered years later. Del Centina states that "after almost two hundred years her ideas were still central", but ultimately her method did not work. Work in philosophy In addition to mathematics, Germain studied philosophy and psychology. She wanted to classify facts and generalize them into laws that could form a system of psychology and sociology, which were then just coming into existence. Her philosophy was highly praised by Auguste Comte. Two of her philosophical works, and , were published, both posthumously. This was due in part to the efforts of Lherbette, her nephew, who collected her philosophical writings and published them. is a history of science and mathematics with Germain's commentary. In , the work admired by Comte, Germain argues that there are no differences between the sciences and the humanities. Final years In 1829 Germain learned that she had breast cancer. Despite the pain, she continued to work. In 1831 Crelle's Journal published her paper on the curvature of elastic surfaces and "a note about finding and in ". Mary Gray records: "She also published in an examination of principles which led to the discovery of the laws of equilibrium and movement of elastic solids." On 27 June 1831, she died in the house at 13 rue de Savoie. Despite Germain's intellectual achievements, her death certificate lists her as a "" (property holder), not a "". But her work was not unappreciated by everyone. When the matter of honorary degrees came up at the University of Göttingen in 1837—six years after Germain's death—Gauss lamented: "she [Germain] proved to the world that even a woman can accomplish something worthwhile in the most rigorous and abstract of the sciences and for	with Joseph Fourier, a secretary of the Academy, who obtained tickets to the sessions for her. Later work in elasticity Germain published her prize-winning essay at her own expense in 1821, mostly because she wanted to present her work in opposition to that of Poisson. In the essay she pointed out some of the errors in her method. In 1826 she submitted a revised version of her 1821 essay to the Academy. According to Andrea Del Centina, the revision included attempts to clarify her work by "introducing certain simplifying hypotheses". This put the Academy in an awkward position, as they felt the paper to be "inadequate and trivial", but they did not want to "treat her as a professional colleague, as they would any man, by simply rejecting the work". So Augustin-Louis Cauchy, who had been appointed to review her work, recommended her to publish it, and she followed his advice. One further work of Germain's on elasticity was published posthumously in 1831, her "". She used the mean curvature in her research (see Honors in number theory). Later work in number theory Renewed interest Germain's best work was in number theory, and her most significant contribution to number theory dealt with Fermat's Last Theorem. In 1815, after the elasticity contest, the Academy offered a prize for a proof of Fermat's Last Theorem. It reawakened Germain's interest in number theory, and she wrote to Gauss again after ten years of no correspondence. In the letter, Germain said that number theory was her preferred field and that it was in her mind all the time she was studying elasticity. She outlined a strategy for a general proof of Fermat's Last Theorem, including a proof for a special case. Germain's letter to Gauss contained her substantial progress toward a proof. She asked Gauss whether her approach to the theorem was worth pursuing. Gauss never answered. Her work on Fermat's Last Theorem Fermat's Last Theorem can be divided into two cases. Case 1 involves all powers p that do not divide any of x, y, or z. Case 2 includes all p that divide at least one of x, y, or z. Germain proposed the following, commonly called "Sophie Germain's theorem": Let p be an odd prime. If there exists an auxiliary prime P = 2Np + 1 (N is any positive integer not divisible by 3) such that: if xp + yp + zp ≡ 0 (mod P), then P divides xyz, and p is not a p-th power residue (mod P). Then the first case of Fermat's Last Theorem holds true for p. Germain used this result to prove the first case of Fermat's Last Theorem for all odd primes p < 100, but according to Andrea Del Centina, "she had actually shown that it holds for every exponent p < 197". L. E. Dickson later used Germain's theorem to prove the first case of Fermat's Last Theorem for odd primes less than 1700. In an unpublished manuscript titled , Germain showed that any counterexamples to Fermat's theorem for p > 5 must be numbers "whose size frightens the imagination", around 40 digits long. Germain did not publish this work. Her brilliant theorem is known only because of the footnote in Legendre's treatise on number theory, where he used it to prove Fermat's Last Theorem for p = 5 (see Correspondence with Legendre). Germain also proved or nearly proved several results that were attributed to Lagrange or were rediscovered years later. Del Centina states that "after almost two hundred years her ideas were still central", but ultimately her method did not work. Work in philosophy In addition to mathematics, Germain studied philosophy and psychology. She wanted to classify facts and generalize them into laws that could form a system of psychology and sociology, which were then just coming into existence. Her philosophy was highly praised by Auguste Comte. Two of her philosophical works, and , were published, both posthumously. This was due in part to the efforts of Lherbette, her nephew, who collected her philosophical writings and published them. is a history of science and mathematics with Germain's commentary. In , the work admired by Comte, Germain argues that there are no differences between the sciences and the humanities. Final years In 1829 Germain learned that she had breast cancer. Despite the pain, she continued to work. In 1831 Crelle's Journal published her paper on the curvature of elastic surfaces and "a note about finding and in ". Mary Gray records: "She also published in an examination of principles which led to the discovery of the laws of equilibrium and movement of elastic solids." On 27 June 1831, she died in the house at 13 rue de Savoie. Despite Germain's intellectual achievements, her death certificate lists her as a "" (property holder), not a "". But her work was not unappreciated by everyone. When the matter of honorary degrees came up at the University of Göttingen in 1837—six years after Germain's death—Gauss lamented: "she [Germain] proved to the world that even a woman can accomplish something worthwhile in the most rigorous and abstract of the sciences and for that reason would well have deserved an honorary degree". Honors Memorials Germain's resting place in the Père Lachaise Cemetery in Paris is marked by a gravestone. At the centennial celebration of her life, a street and a girls' school were named after her, and a plaque was placed at the house where she died. The school houses a bust commissioned by the Paris City Council. In January 2020, Satellogic, a high-resolution Earth observation imaging and analytics company, launched a ÑuSat type micro-satellite named in honor of Sophie Germain. Honors in number theory E. Dubouis defined a sophien of a prime to be a prime where , for such that yield such that has no solutions when and are prime to . A Sophie Germain prime is a prime such that is also prime. The Germain curvature (also called mean curvature) is , where and are the maximum and minimum values of the normal curvature. Sophie Germain's identity states that for any , Criticisms Contemporary praise and criticisms Vesna Petrovich found that the educated world's response to the publication in 1821 of Germain's prize-winning essay "ranged from polite to indifferent". Yet, some critics had high praise for it. Of her essay in 1821, Cauchy said: "[it] was a work for which the name of its author and the importance of the subject both deserved the attention of mathematicians". Germain was also included in H. J. Mozans' book "Woman in Science", although Marilyn Bailey Ogilvie claims that the biography "is inaccurate and the notes and bibliography
documentary film about the Holocaust Amata shoa, a moth of the family Erebidae SHOA, Hydrographic and Oceanographic Service of the Chilean Navy	The Holocaust, also known as "the Shoah" or Ha-Shoah in Hebrew Shewa, a region of Ethiopia, sometimes spelled Shoa Shoah (film), 1985 French documentary film about the Holocaust Amata
The male counterpart to the succubus is the incubus. Etymology The term derives from Late Latin succuba "paramour" from succubare "to lie beneath" (sub- "under" and cubare "to lie"), used to describe this female supernatural being's implied sexual position relative to the male sleeper's position. The English word succubus dates from the late 14th century. In folklore As depicted in the Jewish mystical treatise Zohar and the medieval Jewish satirical text Alphabet of Ben Sira, Lilith was Adam's first wife, who later became a succubus. She left Adam and refused to return to the Garden of Eden after she mated with the archangel Samael. In Zoharistic Kabbalah, there were four succubi who mated with the archangel Samael. There were four original queens of the demons: Lilith, Eisheth, Agrat bat Mahlat, and Naamah. A succubus may take a form of a beautiful young girl but closer inspection may reveal deformities of her body, such as bird-like claws or serpentine tails. Folklore also describes the act of cunnilingus on their vulvas, which drip with urine and other fluids. In later folklore, a succubus took the form of a siren. Throughout history, priests and rabbis, including Hanina Ben Dosa and Abaye, tried to curb the power of succubi over humans. However, not all succubi were malevolent. According to Walter Map in the satire De Nugis Curialium (Trifles of Courtiers), Pope Sylvester II (999–1003) was allegedly involved with a succubus named Meridiana, who helped him achieve his high rank in the Catholic Church. Before his death, he confessed of his sins and died repentant. Ability to reproduce According to the Kabbalah and the school of Rashba, the original three queens of the demons, Agrat Bat Mahlat, Naamah, Eisheth Zenunim, and all their cohorts give birth to children, except Lilith. According to other legends, the children of Lilith are called Lilin. According to the Malleus Maleficarum, or "Witches' Hammer", written by Heinrich Kramer (Institoris) in 1486, succubi collect semen from men they seduce. Incubi, or male demons, then use the semen to impregnate human females, thus explaining how demons could apparently sire children despite the traditional belief that they were incapable of reproduction.	rank in the Catholic Church. Before his death, he confessed of his sins and died repentant. Ability to reproduce According to the Kabbalah and the school of Rashba, the original three queens of the demons, Agrat Bat Mahlat, Naamah, Eisheth Zenunim, and all their cohorts give birth to children, except Lilith. According to other legends, the children of Lilith are called Lilin. According to the Malleus Maleficarum, or "Witches' Hammer", written by Heinrich Kramer (Institoris) in 1486, succubi collect semen from men they seduce. Incubi, or male demons, then use the semen to impregnate human females, thus explaining how demons could apparently sire children despite the traditional belief that they were incapable of reproduction. Children so begotten—cambions—were supposed to be those that were born deformed, or more susceptible to supernatural influences. While the book does not address why a human female impregnated with the semen of a human male would not produce regular human offspring, an explanation could be that the semen is altered before being transferred to the female host. However in some lore, the child is born deformed because the conception was unnatural. King James in his dissertation titled Dæmonologie refutes the possibility for angelic entities to reproduce and instead offered a suggestion that a devil would carry out two methods of impregnating women: the first, to steal the sperm out of a dead man and deliver it into a woman. If a demon could extract the semen quickly, the substance could not be instantly transported to a female host, causing it to go cold. This explains his view that succubi and incubi were the same demonic entity only to be described differently based on the tormented sexes being conversed with. The second method was the idea that a dead body could be possessed by a devil, causing it to rise and have sexual relations with others. However, there is no mention of a female corpse being possessed to elicit sex from men. In non-Western literature Buddhist canon A Buddhist scripture regarding prayer to Avalokiteśvara, the Dharani Sutra of Amoghapāśa, promises to those who pray that
album, "Woman on the Tier", was featured on the soundtrack of the movie Dead Man Walking. In 1997 she took a singing part on the concept album Heaven and Hell, a musical interpretation of the seven deadly sins by her colleague Joe Jackson, with whom she had already collaborated in 1986 on "Left of Center" from the Pretty in Pink soundtrack (with Vega singing and Jackson playing piano). In 1999, Avon Books published Vega's book The Passionate Eye: The Collected Writings of Suzanne Vega, a volume of poems, lyrics, essays and journalistic pieces. 2000s In September 2001, Vega released a new album entitled Songs in Red and Gray. Three songs deal with Vega's divorce from her first husband, Mitchell Froom. At the memorial concert for her brother Tim Vega in December 2002, Vega began her role as the subject of the direct-cinema documentary, Some Journey, directed by Christopher Seufert of Mooncusser Films. The documentary has not been completed. Underground hip hop duo Felt named a track on their album Felt: A Tribute to Christina Ricci, released in 2002, "Suzanne Vega". In 2003, the 21-song greatest hits compilation Retrospective: The Best of Suzanne Vega was released. (The UK version of Retrospective included an eight-song bonus CD as well as a DVD containing 12 songs). In the same year she was invited by Grammy Award-winning jazz guitarist Bill Frisell to play at the Century of Song concerts at the famed Ruhrtriennale in Germany. In 2003, she hosted the American Public Media radio series American Mavericks, about 20th century American composers, which received the Peabody Award for Excellence in Broadcasting. On August 3, 2006, Vega became the first major recording artist to perform live in the Internet-based virtual world, Second Life. The event was hosted by John Hockenberry of public radio's The Infinite Mind. On September 17, 2006, she performed in Central Park, as part of a benefit concert for the Save Darfur Coalition. During the concert she highlighted her support for Amnesty International, of which she has been a member since 1988. In early October 2006, Vega participated in the Academia Film Olomouc (AFO) in Olomouc, the Czech Republic, the oldest festival of documentary films in Europe, in which she appeared as a main guest. She was invited there as the subject of the documentary film by director Christopher Seufert, that had a test screening at the festival. At the end of the festival she performed her classic songs and added one brand new piece called "New York Is a Woman". Vega is also interviewed in the book Everything Is Just a Bet which was published in Czech in October 2006. The book contains 12 interview transcriptions from the talk show called Stage Talks that regularly runs in the Švandovo divadlo (Švandovo Theatre) in Prague. Vega introduced the book to the audience of the Švandovo divadlo (Švandovo Theatre), and together with some other Czech celebrities gave a signing session. She signed a new recording contract with Blue Note Records in the spring of 2006, and released Beauty & Crime on July 17, 2007. The album, produced by Jimmy Hogarth, won a Grammy Award for Best Engineered Album, Non-Classical. Her contract was not renewed and she was released in June 2008. In 2007, Vega followed the lead of numerous other mainstream artists and released her track "Pornographer's Dream" as podsafe. The song spent two weeks at number-one during 2007 and finished as the No. 11 hit of the year on the PMC Top10's annual countdown. In 2015, Vega joined The 14th Annual Independent Music Awards judging panel to assist independent musicians' careers. She was also a judge for the 6th, 7th, 8th, 9th, 10th, 11th, 12th and 13th Independent Music Awards. In 2008, fire at a Universal Music Group vault in Los Angeles County resulted in the loss or damage of some Vega recordings. 2010s A partial cover version of her song Tom's Diner was used to introduce the 2010 British movie 4.3.2.1, with its lyrics largely rewritten to echo the plot. This musical hybrid was released as "Keep Moving". Vega participated in the Danger Mouse/Sparklehorse/David Lynch collaboration Dark Night of the Soul. She wrote both melody and lyrics for her song, which is titled "The Man Who Played God", inspired by a biography of Pablo Picasso. Vega sang lead vocals on the song "Now I Am an Arsonist" with singer-songwriter Jonathan Coulton on his 2011 album, Artificial Heart. Vega has re-recorded her back-catalogue, both for artistic and commercial (and control) reasons, in the Close-up series. Vol. 1 (Love Songs) and Vol. 2 (People & Places) appeared in 2010 while Vol. 3 (States of Being) was released in July 2011 followed by Vol. 4 (Songs of Family) in September 2012. Volumes 2, 3 and 4 of the Close-Up albums included previously unrecorded material; Volumes 2 and 3 each included one new collaboratively written song, while Volume 4 included three songs that Vega had written years earlier, but had not previously gotten around to recording. In all, Vega's Close-Up series features 60 re-recorded songs and five new compositions, representing about three-quarters of her lifetime songwriting output. While performing live, Vega and long-term collaborator Gerry Leonard began to introduce a number of new songs into the setlist, including the live favorite "I Never Wear White". Over the course of a year, the songs were completed and recorded in a live-studio setting with the help of a number of guests. Produced by Leonard, Tales from the Realm of the Queen of Pentacles was released in February	death threats from an obsessed fan ahead of the festival. The acappella "Tom's Diner" from Solitude Standing became a hit in 1990, having been remixed by two British dance producers under the name DNA. The track was originally a bootleg, until Vega allowed DNA to release it through her record company, and it became her biggest hit. 1990s Vega's third album, Days of Open Hand (1990), continued in the style of her first two albums. In 1992, she released the album 99.9F°. It consists of a mixture of folk music, dance beats and industrial music. This record was awarded Gold status by the RIAA in recognition of selling over 500,000 copies in the U.S. The single "Blood Makes Noise" from this album peaked at number-one on Billboard's Modern Rock Tracks. Vega later married the album's producer Mitchell Froom. Her fifth album, Nine Objects of Desire, was released in 1996. The music varies between a frugal, simple style and the industrial production of 99.9F°. This album contains "Caramel", featured in the movie The Truth About Cats & Dogs, and later the trailer for the movie Closer. A song not included on that album, "Woman on the Tier", was featured on the soundtrack of the movie Dead Man Walking. In 1997 she took a singing part on the concept album Heaven and Hell, a musical interpretation of the seven deadly sins by her colleague Joe Jackson, with whom she had already collaborated in 1986 on "Left of Center" from the Pretty in Pink soundtrack (with Vega singing and Jackson playing piano). In 1999, Avon Books published Vega's book The Passionate Eye: The Collected Writings of Suzanne Vega, a volume of poems, lyrics, essays and journalistic pieces. 2000s In September 2001, Vega released a new album entitled Songs in Red and Gray. Three songs deal with Vega's divorce from her first husband, Mitchell Froom. At the memorial concert for her brother Tim Vega in December 2002, Vega began her role as the subject of the direct-cinema documentary, Some Journey, directed by Christopher Seufert of Mooncusser Films. The documentary has not been completed. Underground hip hop duo Felt named a track on their album Felt: A Tribute to Christina Ricci, released in 2002, "Suzanne Vega". In 2003, the 21-song greatest hits compilation Retrospective: The Best of Suzanne Vega was released. (The UK version of Retrospective included an eight-song bonus CD as well as a DVD containing 12 songs). In the same year she was invited by Grammy Award-winning jazz guitarist Bill Frisell to play at the Century of Song concerts at the famed Ruhrtriennale in Germany. In 2003, she hosted the American Public Media radio series American Mavericks, about 20th century American composers, which received the Peabody Award for Excellence in Broadcasting. On August 3, 2006, Vega became the first major recording artist to perform live in the Internet-based virtual world, Second Life. The event was hosted by John Hockenberry of public radio's The Infinite Mind. On September 17, 2006, she performed in Central Park, as part of a benefit concert for the Save Darfur Coalition. During the concert she highlighted her support for Amnesty International, of which she has been a member since 1988. In early October 2006, Vega participated in the Academia Film Olomouc (AFO) in Olomouc, the Czech Republic, the oldest festival of documentary films in Europe, in which she appeared as a main guest. She was invited there as the subject of the documentary film by director Christopher Seufert, that had a test screening at the festival. At the end of the festival she performed her classic songs and added one brand new piece called "New York Is a Woman". Vega is also interviewed in the book Everything Is Just a Bet which was published in Czech in October 2006. The book contains 12 interview transcriptions from the talk show called Stage Talks that regularly runs in the Švandovo divadlo (Švandovo Theatre) in Prague. Vega introduced the book to the audience of the Švandovo divadlo (Švandovo Theatre), and together with some other Czech celebrities gave a signing session. She signed a new recording contract with Blue Note Records in the spring of 2006, and released Beauty & Crime on July 17, 2007. The album, produced by Jimmy Hogarth, won a Grammy Award for Best Engineered Album, Non-Classical. Her contract was not renewed and she was released in June 2008. In 2007, Vega followed the lead of numerous other mainstream artists and released her track "Pornographer's Dream" as podsafe. The song spent two weeks at number-one during 2007 and finished as the No. 11 hit of the year on the PMC Top10's annual countdown. In 2015, Vega joined The 14th Annual Independent Music Awards judging panel to assist independent musicians' careers. She was also a judge for the 6th, 7th, 8th, 9th, 10th, 11th, 12th and 13th Independent Music Awards. In 2008, fire at a Universal Music Group vault in Los Angeles County resulted in the loss or damage of some Vega recordings. 2010s A partial cover version of her song Tom's Diner was used to introduce the 2010 British movie 4.3.2.1, with its lyrics largely rewritten to echo the plot. This musical hybrid was released as "Keep Moving". Vega participated in the Danger Mouse/Sparklehorse/David Lynch collaboration Dark Night of the Soul. She wrote both melody and lyrics for her song, which is titled "The Man Who Played God", inspired by a biography of Pablo Picasso. Vega sang lead vocals on the song "Now I Am an Arsonist" with singer-songwriter Jonathan Coulton on his 2011 album, Artificial Heart. Vega has re-recorded her back-catalogue, both for artistic and commercial (and control) reasons, in the Close-up series. Vol. 1 (Love Songs) and Vol. 2 (People & Places) appeared in 2010 while Vol. 3 (States of Being) was released in July 2011 followed by Vol. 4 (Songs of Family) in September 2012. Volumes 2, 3 and 4 of the Close-Up albums included previously unrecorded material; Volumes 2 and 3 each included one new collaboratively written song, while Volume 4 included three songs that Vega had written years earlier, but had not previously gotten around to recording. In all, Vega's Close-Up series features 60 re-recorded songs and five new compositions, representing
formed by adjoining an element to and defining for all . The notation denotes a monoid obtained from by adjoining an identity if necessary ( for a monoid). Similarly, every magma has at most one absorbing element, which in semigroup theory is called a zero. Analogous to the above construction, for every semigroup , one can define , a semigroup with 0 that embeds . Subsemigroups and ideals The semigroup operation induces an operation on the collection of its subsets: given subsets A and B of a semigroup S, their product , written commonly as AB, is the set (This notion is defined identically as it is for groups.) In terms of this operation, a subset A is called a subsemigroup if AA is a subset of A, a right ideal if AS is a subset of A, and a left ideal if SA is a subset of A. If A is both a left ideal and a right ideal then it is called an ideal (or a two-sided ideal). If S is a semigroup, then the intersection of any collection of subsemigroups of S is also a subsemigroup of S. So the subsemigroups of S form a complete lattice. An example of a semigroup with no minimal ideal is the set of positive integers under addition. The minimal ideal of a commutative semigroup, when it exists, is a group. Green's relations, a set of five equivalence relations that characterise the elements in terms of the principal ideals they generate, are important tools for analysing the ideals of a semigroup and related notions of structure. The subset with the property that every element commutes with any other element of the semigroup is called the center of the semigroup. The center of a semigroup is actually a subsemigroup. Homomorphisms and congruences A semigroup homomorphism is a function that preserves semigroup structure. A function between two semigroups is a homomorphism if the equation . holds for all elements a, b in S, i.e. the result is the same when performing the semigroup operation after or before applying the map f. A semigroup homomorphism between monoids preserves identity if it is a monoid homomorphism. But there are semigroup homomorphisms which are not monoid homomorphisms, e.g. the canonical embedding of a semigroup without identity into . Conditions characterizing monoid homomorphisms are discussed further. Let be a semigroup homomorphism. The image of is also a semigroup. If is a monoid with an identity element , then is the identity element in the image of . If is also a monoid with an identity element and belongs to the image of , then , i.e. is a monoid homomorphism. Particularly, if is surjective, then it is a monoid homomorphism. Two semigroups S and T are said to be isomorphic if there exists a bijective semigroup homomorphism . Isomorphic semigroups have the same structure. A semigroup congruence is an equivalence relation that is compatible with the semigroup operation. That is, a subset that is an equivalence relation and and implies for every in S. Like any equivalence relation, a semigroup congruence induces congruence classes and the semigroup operation induces a binary operation on the congruence classes: Because is a congruence, the set of all congruence classes of forms a semigroup with , called the quotient semigroup or factor semigroup, and denoted . The mapping is a semigroup homomorphism, called the quotient map, canonical surjection or projection; if S is a monoid then quotient semigroup is a monoid with identity . Conversely, the kernel of any semigroup homomorphism is a semigroup congruence. These results are nothing more than a particularization of the first isomorphism theorem in universal algebra. Congruence classes and factor monoids are the objects of study in string rewriting systems. A nuclear congruence on S is one which is the kernel of an endomorphism of S. A semigroup S satisfies the maximal condition on congruences if any family of congruences on S, ordered by inclusion, has a maximal element. By Zorn's lemma, this is equivalent to saying that the ascending chain condition holds: there is no infinite strictly ascending chain of congruences on S. Every ideal I of a semigroup induces a factor semigroup, the Rees factor semigroup, via the congruence ρ defined by if either , or both x and y are in I. Quotients and divisions The following notions introduce the idea that a semigroup is contained in another one. A semigroup T is a quotient of a semigroup S if there is a surjective semigroup morphism from S to T. For example, is a quotient of , using the morphism consisting of taking the remainder modulo 2 of an integer. A semigroup T divides a semigroup S, noted if T is a quotient of a subsemigroup S. In particular, subsemigroups of S divides T, while it is not necessarily the case that there are a quotient of S. Both of those relation are transitive. Structure of semigroups For any subset A of S there is a smallest subsemigroup T of S which contains A, and we say that A generates T. A single element x of S generates the subsemigroup { xn n ∈ Z+ }. If this is finite, then x is said to be of finite order, otherwise it is of infinite order. A semigroup is said to be periodic if all of its elements are of finite order. A semigroup generated by a single element is said to be monogenic (or cyclic). If a monogenic semigroup is infinite then it is isomorphic to the semigroup of positive integers with the operation of addition. If it is finite and nonempty, then it must contain at least one idempotent. It follows that every nonempty periodic semigroup has at least one idempotent. A subsemigroup which is also a group is called a subgroup. There is a close relationship between the subgroups of a semigroup and its idempotents. Each subgroup contains exactly one idempotent, namely the identity element of the subgroup. For each idempotent e of the semigroup there is a unique maximal subgroup containing e. Each maximal subgroup arises in this way, so there is a one-to-one correspondence between idempotents and maximal subgroups. Here the term maximal subgroup differs from its standard use in group theory. More can often be said when the order is finite. For example, every nonempty finite semigroup is periodic, and has a minimal ideal and at least one idempotent. The number of finite semigroups of a given size (greater than 1) is (obviously) larger than the number of groups of the same size. For example, of the sixteen possible "multiplication tables" for a set of two elements eight form semigroups whereas only four of these are monoids and only two form groups. For more on the structure of finite semigroups, see Krohn–Rhodes theory. Special classes of semigroups A monoid is a semigroup with an identity element. A group is a semigroup with an identity element and an inverse element. A subsemigroup is a subset of a semigroup that is closed under the semigroup operation. A cancellative semigroup is one having the cancellation property: implies and similarly for . A band is a semigroup whose operation is idempotent. A semilattice is a semigroup whose operation is idempotent and commutative. 0-simple semigroups. Transformation semigroups: any finite semigroup S can be represented by transformations of a (state-) set Q of at most states. Each element x of S then maps Q into itself and sequence xy is defined by for each q in Q. Sequencing clearly is an associative operation, here equivalent to function composition. This representation is basic for any automaton or finite-state machine (FSM). The bicyclic semigroup is in fact a monoid, which can be described as the free semigroup on two generators p and q, under the relation . C0-semigroups. Regular semigroups. Every element x has at least one inverse y satisfying and ; the elements x and y are sometimes called "mutually inverse". Inverse semigroups are regular semigroups where every element has exactly one inverse. Alternatively, a regular semigroup is inverse if and only if any two idempotents commute. Affine semigroup: a semigroup that is isomorphic to a finitely-generated subsemigroup of Zd. These semigroups have applications to commutative algebra. Structure theorem for commutative semigroups There is a structure theorem for commutative semigroups in terms of semilattices. A semilattice (or more precisely a meet-semilattice) is a partially ordered set where every pair of elements has a greatest lower bound, denoted . The operation makes into a semigroup satisfying the additional idempotence law . Given a homomorphism from an arbitrary semigroup to a semilattice, each inverse image is a (possibly empty) semigroup. Moreover, becomes graded by , in the sense that If is onto, the semilattice is isomorphic to the quotient of by the equivalence relation such that if and only if . This equivalence relation is a semigroup congruence, as defined above. Whenever we take the quotient of a commutative semigroup by a congruence, we get another commutative semigroup. The structure theorem says that for any commutative semigroup , there is a finest congruence such that the quotient of by this equivalence relation is a semilattice. Denoting this semilattice by , we get a homomorphism from onto . As mentioned, becomes graded by this semilattice. Furthermore, the components are all Archimedean semigroups. An Archimedean semigroup is one where given any pair of elements , there exists an element and such that . The Archimedean property follows immediately from the ordering in the semilattice , since with this ordering we have if and only if for some and . Group of fractions The group of fractions or group completion of a semigroup S is the group generated by the elements of S as generators and all equations which hold true in S as relations. There is an obvious semigroup homomorphism which sends each element of S to the corresponding generator. This has a universal property for morphisms from S to a group: given any group H and any semigroup homomorphism , there exists a unique group homomorphism with k=fj. We may think of G as the "most general" group that contains a homomorphic image of S. An important question is to characterize those semigroups for which this map is an embedding. This need not	classes and factor monoids are the objects of study in string rewriting systems. A nuclear congruence on S is one which is the kernel of an endomorphism of S. A semigroup S satisfies the maximal condition on congruences if any family of congruences on S, ordered by inclusion, has a maximal element. By Zorn's lemma, this is equivalent to saying that the ascending chain condition holds: there is no infinite strictly ascending chain of congruences on S. Every ideal I of a semigroup induces a factor semigroup, the Rees factor semigroup, via the congruence ρ defined by if either , or both x and y are in I. Quotients and divisions The following notions introduce the idea that a semigroup is contained in another one. A semigroup T is a quotient of a semigroup S if there is a surjective semigroup morphism from S to T. For example, is a quotient of , using the morphism consisting of taking the remainder modulo 2 of an integer. A semigroup T divides a semigroup S, noted if T is a quotient of a subsemigroup S. In particular, subsemigroups of S divides T, while it is not necessarily the case that there are a quotient of S. Both of those relation are transitive. Structure of semigroups For any subset A of S there is a smallest subsemigroup T of S which contains A, and we say that A generates T. A single element x of S generates the subsemigroup { xn n ∈ Z+ }. If this is finite, then x is said to be of finite order, otherwise it is of infinite order. A semigroup is said to be periodic if all of its elements are of finite order. A semigroup generated by a single element is said to be monogenic (or cyclic). If a monogenic semigroup is infinite then it is isomorphic to the semigroup of positive integers with the operation of addition. If it is finite and nonempty, then it must contain at least one idempotent. It follows that every nonempty periodic semigroup has at least one idempotent. A subsemigroup which is also a group is called a subgroup. There is a close relationship between the subgroups of a semigroup and its idempotents. Each subgroup contains exactly one idempotent, namely the identity element of the subgroup. For each idempotent e of the semigroup there is a unique maximal subgroup containing e. Each maximal subgroup arises in this way, so there is a one-to-one correspondence between idempotents and maximal subgroups. Here the term maximal subgroup differs from its standard use in group theory. More can often be said when the order is finite. For example, every nonempty finite semigroup is periodic, and has a minimal ideal and at least one idempotent. The number of finite semigroups of a given size (greater than 1) is (obviously) larger than the number of groups of the same size. For example, of the sixteen possible "multiplication tables" for a set of two elements eight form semigroups whereas only four of these are monoids and only two form groups. For more on the structure of finite semigroups, see Krohn–Rhodes theory. Special classes of semigroups A monoid is a semigroup with an identity element. A group is a semigroup with an identity element and an inverse element. A subsemigroup is a subset of a semigroup that is closed under the semigroup operation. A cancellative semigroup is one having the cancellation property: implies and similarly for . A band is a semigroup whose operation is idempotent. A semilattice is a semigroup whose operation is idempotent and commutative. 0-simple semigroups. Transformation semigroups: any finite semigroup S can be represented by transformations of a (state-) set Q of at most states. Each element x of S then maps Q into itself and sequence xy is defined by for each q in Q. Sequencing clearly is an associative operation, here equivalent to function composition. This representation is basic for any automaton or finite-state machine (FSM). The bicyclic semigroup is in fact a monoid, which can be described as the free semigroup on two generators p and q, under the relation . C0-semigroups. Regular semigroups. Every element x has at least one inverse y satisfying and ; the elements x and y are sometimes called "mutually inverse". Inverse semigroups are regular semigroups where every element has exactly one inverse. Alternatively, a regular semigroup is inverse if and only if any two idempotents commute. Affine semigroup: a semigroup that is isomorphic to a finitely-generated subsemigroup of Zd. These semigroups have applications to commutative algebra. Structure theorem for commutative semigroups There is a structure theorem for commutative semigroups in terms of semilattices. A semilattice (or more precisely a meet-semilattice) is a partially ordered set where every pair of elements has a greatest lower bound, denoted . The operation makes into a semigroup satisfying the additional idempotence law . Given a homomorphism from an arbitrary semigroup to a semilattice, each inverse image is a (possibly empty) semigroup. Moreover, becomes graded by , in the sense that If is onto, the semilattice is isomorphic to the quotient of by the equivalence relation such that if and only if . This equivalence relation is a semigroup congruence, as defined above. Whenever we take the quotient of a commutative semigroup by a congruence, we get another commutative semigroup. The structure theorem says that for any commutative semigroup , there is a finest congruence such that the quotient of by this equivalence relation is a semilattice. Denoting this semilattice by , we get a homomorphism from onto . As mentioned, becomes graded by this semilattice. Furthermore, the components are all Archimedean semigroups. An Archimedean semigroup is one where given any pair of elements , there exists an element and such that . The Archimedean property follows immediately from the ordering in the semilattice , since with this ordering we have if and only if for some and . Group of fractions The group of fractions or group completion of a semigroup S is the group generated by the elements of S as generators and all equations which hold true in S as relations. There is an obvious semigroup homomorphism which sends each element of S to the corresponding generator. This has a universal property for morphisms from S to a group: given any group H and any semigroup homomorphism , there exists a unique group homomorphism with k=fj. We may think of G as the "most general" group that contains a homomorphic image of S. An important question is to characterize those semigroups for which this map is an embedding. This need not always be the case: for example, take S to be the semigroup of subsets of some set X with set-theoretic intersection as the binary operation (this is an example of a semilattice). Since holds for all elements of S, this must be true for all generators of G(S) as well: which is therefore the trivial group. It is clearly necessary for embeddability that S have the cancellation property. When S is commutative this condition is also sufficient and the Grothendieck group of the semigroup provides a construction of the group of fractions. The problem for non-commutative semigroups can be traced to the first substantial paper on semigroups. Anatoly Maltsev gave necessary and sufficient conditions for embeddability in 1937. Semigroup methods in partial differential equations Semigroup theory can be used to study some problems in the field of partial differential equations. Roughly speaking, the semigroup approach is to regard a time-dependent partial differential equation as an ordinary differential equation on a function space. For example, consider the following initial/boundary value problem for the heat equation on the spatial interval and times : Let be the Lp space of square-integrable real-valued functions with domain the interval and let A be the second-derivative operator with domain where H2 is a Sobolev space. Then the above initial/boundary value problem can be interpreted as an initial value problem for an ordinary differential equation on the space X: On an heuristic level, the solution to this problem "ought" to be . However, for a rigorous treatment, a meaning must be given to the exponential of tA. As a function of t, exp(tA) is a semigroup of operators from X to itself, taking the initial state u0 at time to the state at time t. The operator A is said to be the infinitesimal generator of the semigroup. History The study of semigroups trailed behind that of other algebraic structures with more complex axioms such as groups or rings. A number of sources attribute the first use of the term (in French) to J.-A. de Séguier in Élements de la Théorie des Groupes Abstraits (Elements of the Theory of Abstract Groups) in 1904. The term is used in English in 1908 in Harold Hinton's Theory of Groups of Finite Order. Anton Sushkevich obtained the first non-trivial results about semigroups. His 1928 paper "Über die endlichen Gruppen ohne das Gesetz der eindeutigen Umkehrbarkeit" ("On finite groups without the rule of unique invertibility") determined the structure of finite simple semigroups and showed that the minimal ideal (or Green's relations J-class) of a finite semigroup is simple. From that point on, the foundations of semigroup theory
on their top 100 games of all time in 2001 praising how the games mode 7 revolutionized racing games. In 2018, Complex listed Super Mario Kart 7th on its "The Best Super Nintendo Games of All Time." LegacySuper Mario Kart has been credited with inventing the "kart racing" subgenre of video gaming and soon after its release several other developers attempted to duplicate its success. In 1994, less than two years after the release of Super Mario Kart, Sega released Sonic Drift; a kart racing game featuring characters from the Sonic the Hedgehog series. Also in 1994 Ubisoft released Street Racer, a kart racing game for the SNES and Mega Drive/Genesis which included a four player mode not present in Super Mario Kart. Apogee Software released Wacky Wheels for PC and Atari Corporation released Atari Karts for the Atari Jaguar in 1995. Future games that followed in the mould of Super Mario Kart include South Park Rally, Konami Krazy Racers, Diddy Kong Racing, Sonic & Sega All-Stars Racing and several racing games in the Crash Bandicoot series. Response to the karting games released since Super Mario Kart has been mixed, with GameSpot describing them as tending to be bad while 1UP.com notes that countless developers have tried to improve upon the Mario Kart formula without success.Super Mario Kart is also credited as being the first non-platforming game to feature multiple playable characters from the Mario franchise. As well as several sequels Nintendo has released numerous other sporting and non-sporting Mario spin-offs since Super Mario Kart; a trend in part accredited to the commercial and critical success of the game. The Mario characters have appeared in many sports games including those relating to basketball, baseball, golf, tennis, and soccer. Non-sporting franchises using the Mario characters have also been created, including the Super Smash Bros. series of fighting games and the Mario Party series of board game based, party games. Mario series characters have also made cameos in games from other series such as SSX on Tour and NBA Street V3, both published by EA Sports. The genre-spanning nature of the Mario series that was sparked off by the success of Super Mario Kart has been described as key to the success and longevity of the franchise; keeping fans interested despite the infrequency of traditional Mario platforming games. Following this model the Mario series has gone on to become the best selling video game franchise of all time with 193 million units sold as of January 2007, almost 40 million units ahead of second-ranked franchise (Pokémon, also by Nintendo).Super Mario Kart was re-released on the Japanese Virtual Console on June 9, 2009, and later in North America on November 23, 2009. Previously, when naming it as one of the most wanted games for the platform in November 2008, Eurogamer stated that problems emulating the Mode 7 graphics were responsible for its absence. The game was also released for the Wii U Virtual Console in Japan during June 2013, and in Europe on March 27, 2014. In addition, North America users were able to get the game starting from August 6, 2014 to celebrate the 22nd anniversary of the game, which also includes the new game update of Mario Kart 8 on August 27, 2014. In 2016, the game was re-released for the New Nintendo 3DS. Nintendo re-released Super Mario Kart in 2017 as part of the company's Super NES Classic Edition.Super Mario 3D World has a stage with a look based on the Mario Circuit racetracks from Super Mario Kart. A remixed version of the music can also be heard. Super Mario Odyssey also has a remix, when racing an RC car around a track in New Donk City in the Metro Kingdom. Sequels Several sequels to Super Mario Kart have been brought out for successive generations of Nintendo consoles, each receiving commercial success and critical acclaim. While some elements have developed throughout the series, the core experience from Super Mario Kart has remained intact. The first sequel, Mario Kart 64, was released in 1996 for the Nintendo 64 and was the first Mario Kart game to feature fully 3D graphics. Although reviewers including IGN and GameSpot felt that the single player gameplay was lacking compared to its predecessor, the simultaneous four-person multiplayer modes – a first for the Nintendo 64 – were praised. The second sequel, Mario Kart: Super Circuit, was released for the Game Boy Advance in 2001. It was described by GameSpot as more of a remake of Super Mario Kart than a sequel to Mario Kart 64 and featured a return to the graphical style of the original. As well as featuring all new tracks, players are able to unlock the original SNES tracks if certain achievements are completed. Mario Kart: Double Dash was released for the GameCube in 2003. Unlike any other Mario Kart game before or since, it features two riders in each kart, allowing for a new form of cooperative multiplayer where one player controls the kart's movement and the other fires weapons. Mario Kart DS, released for the Nintendo DS in 2005, was the first Mario Kart game to include online play via the Nintendo Wi-Fi Connection. It went on to become the best selling hand-held racing game of all time, selling 7.83 million units. The game also marks the debut of tracks appearing in previous games. Mario Kart Wii was released for the Wii in 2008 and incorporates motion controls and 12-player racing. Like Mario Kart DS, it includes on-line play; it also allows racers to play as user-created Miis (after unlocking the Mii character) as well as Mario series characters and comes packaged with the Wii Wheel peripheral, which can act as the game's primary control mechanism when coupled with a Wii Remote. Mario Kart Wii went on to be the worldwide best-selling game of 2008 ahead of another Nintendo game – Wii Fit – and the critically acclaimed Grand Theft Auto IV. Mario Kart 7 for the Nintendo 3DS was released in 2011, which features racing on land, sea, and air. Also in Mario Kart 7 is the ability to customize your kart and to race in first-person mode. Three Mario Kart arcade games have also been released, Mario Kart Arcade GP in 2005, Mario Kart Arcade GP 2 in 2007, and Mario Kart Arcade GP DX in 2013. All of them were developed jointly by Nintendo and Namco and feature classic Namco characters including Pac-Man and Blinky. The most recent entry in the series is Mario Kart 8 for the Wii U, which was released at the end of May 2014, which brings back gliders and propellers from Mario Kart 7 as well as 12-player racing in Mario Kart Wii. Mario Kart 8 also includes a new feature called Mario Kart TV, where players can watch highlights of previous races and uploading them to YouTube. Another new feature is anti-gravity racing, where players can race on walls and ceilings. An enhanced port titled “Mario Kart 8 Deluxe” was released on the Nintendo Switch on April 28, 2017. The game keeps most elements from the Wii U version, while adding more characters, kart parts, battle modes, and battle stages. The port received universal critical acclaim,	positions in a race; first to fourth place receive nine, six, three and one points. If a player finished in the same position three times in a row, then an extra life is awarded. The finishing order for that race will then become the starting grid for the next race; for example, if a player finished in first place, then that player will start the next race in the same position. The racer with the highest number of points after all five races have been completed wins the cup. In time trial mode, players race against the clock through the same tracks that are present in Mario Kart GP mode, attempting to set the fastest time possible. Super Mario Kart also has three multiplayer modes; Mario Kart GP, Match Race, and Battle Mode. The multiplayer modes support two players and the second player uses the bottom half of the screen which is used as a map in the single-player modes. Mario Kart GP is the same as in single-player, the only difference being that there are now two human-controlled and six computer-controlled drivers. Match Race involves the two players going head to head on a track of their choice without any opponents. In Battle Mode, the two players again go head to head, but this time in one of four dedicated Battle Mode courses. Each player starts with three balloons around their kart which can be popped by power-ups fired by the other player. The first player to have all three of their balloons popped loses. Characters Super Mario Kart features eight playable characters from the Mario series – Mario, Luigi, Princess Peach, Yoshi, Bowser, Donkey Kong Jr., Koopa Troopa and Toad. Each character's kart has different capabilities with differing levels of top speed, acceleration and handling. Mario, Luigi, Peach, Yoshi, Bowser and Toad returned in all of the subsequent Mario Kart games starting with Mario Kart 64. During races, computer-controlled characters have special items, or superpowers, which they are able to use. These powers are specific to each character; for example, Yoshi drops eggs which cause players who hit them to lose coins and spin, while Donkey Kong Jr. throws bananas. The characters are rendered as sprites portrayed from sixteen different angles. More recently, Nintendojo called the sprites "not-so-pretty" when they are rendered at a distance, and IGN has commented on the dated look of the game. Super Mario Kart was the first game to feature playable characters from the Mario series other than Mario or Luigi in a non-platforming game and the selection and different attributes of the characters is regarded as one of the game's strengths, IGN describing a well-balanced "all-star cast". All of the characters present in Super Mario Kart have gone on to appear in later games in the series, except for Donkey Kong Jr. and Koopa Troopa, who have only appeared intermittently after being replaced by Wario and Donkey Kong respectively in Mario Kart 64. Tracks The tracks in Super Mario Kart are based on locations in Super Mario World such as Donut Plains. Each of the four cups contains five different tracks for a total of twenty unique tracks, additionally there are four unique Battle Mode courses. The course outlines are marked out by impassable barriers and feature a variety of bends ranging from sharp hairpins to wide curves which players can power slide around. Numerous obstacles themed from the Mario series appear, such as Thwomps in the Bowser's Castle tracks, the Cheep-Cheeps from Super Mario World in Koopa Beach and pipe barriers which are found in the Mario Circuit tracks. Other features include off-road sections which slow down the karts such as the mud bogs in the Choco Island tracks. Each single-player track is littered with coins and power-up tiles, as well as turbo tiles which give the karts a boost of speed and jumps which launch the karts into the air. The tracks have received positive commentary with GameSpy describing them as wonderfully designed and IGN calling them perfect. When naming its top five Mario Kart tracks of all time in 2008, 1UP.com named Battle Mode Course 4 at number three and Rainbow Road – along with its subsequent versions in the series – at number one. The track themes in Super Mario Kart influenced later games in the series; recurring themes that first appeared in Super Mario Kart include haunted tracks, Bowser's castle and Rainbow Road. Some of the tracks from Super Mario Kart have been duplicated in later games. All twenty of the original tracks are unlockable as an extra feature in the Game Boy Advance sequel Mario Kart: Super Circuit. Remakes of Mario Circuit 1, Donut Plains 1, Koopa Beach 2 and Choco Island 2 appear as part of the Retro Grand Prix series in Mario Kart DS, remakes of Ghost Valley 2, Mario Circuit 3, and Battle Course 4 appear as part of the Retro Grand Prix and battles in Mario Kart Wii, remakes of Mario Circuit 2 and Rainbow Road appear as part of the Retro Grand Prix in Mario Kart 7, a remake of Donut Plains 3 appears as part of the Retro Grand Prix and battles in Mario Kart 8, a second remake of Rainbow Road appears in Mario Kart 8's first downloadable content pack, and a remake of Battle Course 1 appears as a Retro Battle Course in Mario Kart 8 Deluxe. Development Super Mario Kart was produced by Mario creator Shigeru Miyamoto and directed by Tadashi Sugiyama and Hideki Konno. The development team set out to produce a racing game capable of displaying two players on the same game screen simultaneously, in contrast to the single-player gameplay F-Zero. This led to simpler tracks than those of F-Zero. Computer and Video Games suggest that this initial emphasis on creating a two player experience is the reason for the game's horizontal split-screen during single-player. Battle Mode was developed from the desire to create a one-on-one mode where victory was not determined simply by competing for rank. Masato Kimura, who worked on F-Zero, served as the lead programmer for Super Mario Kart. The game did not start out as a Mario series game and the first prototype featured a generic kart racer character; the team decided that characters three heads tall would best suit the design of the karts. They did not decide to incorporate Mario characters until a few months into development. The choice was made after the development team when observing how one kart looked to another driving past it, decided to see what it would look like with Mario in the kart. Thinking that having Mario in the kart looked better than previous designs, the idea of a Mario themed racing game was born. Notable in the development of Super Mario Kart was its use of Mode 7 graphics. First seen in F-Zero, Mode 7 is a form of texture mapping available on the SNES which allows a plane to be rotated and scaled freely, achieving a pseudo-three-dimensional appearance. 1UP.com have credited the use of Mode 7 with giving the game graphics which at the time of release were considered to be "breathtaking". Retrospective reflection on the Mode 7 visuals was mixed, with IGN stating that the once revolutionary technology now looks "crude and flickery". Super Mario Kart featured a DSP (Digital Signal Processor) chip; DSPs were used in SNES games as they provided a better handling of floating point calculations to assist with three-dimensional maths. The DSP-1 chip that was used in Super Mario Kart went on to be the most popular DSP chip to be used in SNES games. The music for the title was created by composer Soyo Oka. Reception Super Mario Kart received critical acclaim and proved to be a commercial success; it received a Player's Choice release after selling one million copies and went on to sell 8.76 million copies worldwide, becoming the fourth best-selling game ever for the SNES. In Japan, it was the top-selling game in September 1992 and became a multi-million seller in 1992, eventually selling a total of in Japan. In Europe, it was the top-selling game during the first quarter of 1993, above the Sega Mega Drive titles Sonic the Hedgehog 2 and Streets of Rage 2 during the same period. In the United Kingdom, Super Mario Kart was the top-selling Super NES game in February 1993, and it went on to be the seventh best-selling game of 1993 with more than 250,000 sales in the country. Aggregate scoring sites GameRankings and MobyGames both give an average of more than 90 percent. Critics praised the game's Mode 7 graphics. Another aspect of the game to have been praised is its gameplay, which Thunderbolt has described as the "deepest [and] most addictive... to be found on the SNES console". Retrospective reviews of the game have been positive with perfect scores given by review sites including Thunderbolt and HonestGamers. The use of the style and characters from the Mario franchise was also praised as well as the individual characteristics of each racer. Mean Machines described the game as having "struck gold" in a way that no other – not even its sequels – has matched and GameSpot named the game as one of the greatest games of all time for its innovation, gameplay and visual style. Entertainment Weekly wrote that although the game might appear to be a "cynical attempt by Nintendo to cash in on its Super Mario franchise" the review concluded that "plunking the familiar characters down in souped-up go-carts actually makes for a delightful racing game." GamePro said the game "does an excellent job of capturing the thrill of Go-card racing, and wraps it up in the familiar, fun, Mario-land atmosphere." The reviewer also praised the use of Mode 7 and challenging CPU-controlled opponents. Super Mario Kart has been listed among the best games ever made several times. In 1996, Next Generation listed it as number 37 on their "Top 100 Games of All Time", commenting that the controls are elegantly designed to offer "supreme fun." In 1999, Next Generation listed Super Mario Kart as number 7 on their "Top 50 Games of All Time", commenting that, "Imitated a thousand times, but never, ever, equalled, Mario Kart changed the rules for the driving game and gave the world one of the most engrossing and addictive two-player experiences ever." Electronic Gaming Monthly ranked it as the 15th best console video game of
ideas as well as Papert". Papert has rethought how schools should work, based on these theories of learning. Logo Papert used Piaget's work in his development of the Logo programming language while at MIT. He created Logo as a tool to improve the way children think and solve problems. A small mobile robot called the "Logo Turtle" was developed, and children were shown how to use it to solve simple problems in an environment of play. A main purpose of the Logo Foundation research group is to strengthen the ability to learn knowledge. Papert insisted a simple language or program that children can learn—like Logo—can also have advanced functionality for expert users. Other work As part of his work with technology, Papert has been a proponent of the Knowledge Machine. He was one of the principals for the One Laptop Per Child initiative to manufacture and distribute The Children's Machine in developing nations. Papert also collaborated with the construction toy manufacturer Lego on their Logo-programmable Lego Mindstorms robotics kits, which were named after his groundbreaking 1980 book. A curated archive of Papert's articles, speeches, and interviews may be found at The Daily Papert. Personal life Papert became a political and anti-apartheid activist early in his life in South Africa. He subsequently chose self exile. He was a leading figure in the revolutionary socialist circle around Socialist Review while living in London in the 1950s. Papert was also a prominent activist against South African apartheid policies during his university education. Papert was married to Dona Strauss, and later to Androula Christofides Henriques . Papert's third wife was MIT professor Sherry Turkle, and together they wrote the influential paper "Epistemological Pluralism and the Revaluation of the Concrete". In his final 24 years, Papert was married to Suzanne Massie, who is a Russian scholar and author of Pavlovsk: The Life of a Russian Palace and Land of the Firebird. Accident in Hanoi Papert (then aged 78), received a serious brain injury when struck by a motor scooter on 5 December 2006 while crossing the street with colleague Uri Wilensky when they were both attending the 17th International Commission on Mathematical Instruction (ICMI) Study conference in Hanoi, Vietnam. He underwent emergency surgery to remove a blood clot at the French Hospital of Hanoi before being transferred in a complex operation by Swiss Air Ambulance (REGA) Bombardier Challenger Jet to Boston, Massachusetts. He was moved to a hospital closer to his home in January 2007, but then developed sepsis which damaged a heart valve, which was later replaced. By 2008 he had returned home, could think and communicate clearly and walk "almost unaided", but still had "some complicated speech problems" and was in receipt of extensive rehabilitation support. His rehabilitation team used some of the very principles of experiential, hands-on learning that he had pioneered. Papert died at his home in Blue Hill, Maine, on 31 July 2016. Awards, honours, and legacy Papert's work has been used by other researchers in the fields of education and computer science. He influenced the work of Uri Wilensky in the design of NetLogo and collaborated with him on the study of knowledge restructurations, as well as the work of Andrea diSessa and the development of "dynaturtles". In 1981, Papert along with several others in the Logo group at MIT, started Logo Computer Systems	in 1963. He held this position until 1967, when he became professor of applied math and was made co-director of the MIT Artificial Intelligence Laboratory by its founding director Professor Marvin Minsky, until 1981; he also served as Cecil and Ida Green professor of education at MIT from 1974 to 1981. Research Papert worked on learning theories, and was known for focusing on the impact of new technologies on learning in general, and in schools as learning organizations in particular. Constructionism At MIT, Papert went on to create the Epistemology and Learning Research Group at the MIT Architecture Machine Group which later became the MIT Media Lab. Here, he was the developer of a theory on learning called constructionism, built upon the work of Jean Piaget in constructivist learning theories. Papert had worked with Piaget at the University of Geneva from 1958 to 1963 and was one of Piaget's protégés; Piaget himself once said that "no one understands my ideas as well as Papert". Papert has rethought how schools should work, based on these theories of learning. Logo Papert used Piaget's work in his development of the Logo programming language while at MIT. He created Logo as a tool to improve the way children think and solve problems. A small mobile robot called the "Logo Turtle" was developed, and children were shown how to use it to solve simple problems in an environment of play. A main purpose of the Logo Foundation research group is to strengthen the ability to learn knowledge. Papert insisted a simple language or program that children can learn—like Logo—can also have advanced functionality for expert users. Other work As part of his work with technology, Papert has been a proponent of the Knowledge Machine. He was one of the principals for the One Laptop Per Child initiative to manufacture and distribute The Children's Machine in developing nations. Papert also collaborated with the construction toy manufacturer Lego on their Logo-programmable Lego Mindstorms robotics kits, which were named after his groundbreaking 1980 book. A curated archive of Papert's articles, speeches, and interviews may be found at The Daily Papert. Personal life Papert became a political and anti-apartheid activist early in his life in South Africa. He subsequently chose self exile. He
acquisition in the course of second-language learning. A number of spaced repetition software programs have been developed to aid the learning process. It is also possible to perform spaced repetition with flashcards using the Leitner system. Alternative names for spaced repetition include spaced rehearsal, expanding rehearsal, graduated intervals, repetition spacing, repetition scheduling, spaced retrieval and expanded retrieval. History Over the years, techniques and tests have been formed to better patients with memory difficulties. Spaced repetition is one of these solutions to help better the patients' minds. Spaced repetition is used in many different areas of memory from remembering facts to remembering how to ride a bike to remembering past events from childhood. Recovery practice is used to see if an individual is able to recall something immediately after they have seen or studied it. Increasing recovery practice is frequently used as a technique in improving long-term memory, essentially for young children trying to learn and older individuals with memory diseases. The basis for spaced repetition research was laid by Hermann Ebbinghaus, who suggested that information loss over time follows a forgetting curve, but that forgetting could be reset with repetition based on active recall. The spaced repetition training was first tested by Landauer and Bjork in 1978; they gathered a group of psychology students showing the students pictures of a certain individual followed by that individual's name. This is also known as a face-name association. With the repetition of seeing the person's name and face they were able to associate the name and face of that individual shown with the expansion of time due to the spaced repetition. Schacter, Rich, and Stampp in 1985 furthered the research to include people suffering from amnesia and other memory disorders. The findings showed that using spaced repetition can not only help students with name face association but individuals dealing with memory diseases. In 1989, C. J. Camp decided that using this technique with Alzheimer's patients may increase their duration of remembering particular things. These results show that the expansion of the time interval shows the strongest benefits for memory. Spaced repetition is a method where the subject is asked to remember a certain fact with the time intervals increasing each time the fact is presented or said. If the subject is able to recall the information correctly the time is doubled to further help them keep the information fresh in their mind to recall in the future. With this method, the patient is able to place the information in their long-term memory. If they are unable to remember the information they go back to the previous step and continue to practice to help make the technique lasting (Vance & Farr, 2007). The expansion is done to ensure a high success level of recalling the information on the first time and increasing the time interval to make the information long-lasting to help keep the information always accessible in their mind. Throughout the development of spaced repetition, they have found that patients using this technique with dementia are able to recall the information weeks—even months—later. The technique has been successful in helping dementia patients remember particular objects' names, daily tasks, name face association, information about themselves, and many other facts and behaviors (Small, 2012). Sufficient test evidence shows that spaced repetition is valuable in learning new information and recalling information from the past. Small combines the works and findings of quite a few scientists to come up with five reasons why spaced repetition works: it helps show the relationship of routine memories, it shows the benefits of learning things with an expansion of time, it helps the patient with Alzheimer's dementia keep their brain active, it has a high success level with little to no errors, and the technique is meaningful for the patient to do and remember more things (Small, 2012). Joltin et al. (2003), had a caregiver train a woman with Alzheimer's by giving her the name of her grandchild over the phone while asking her to associate with the picture of the grandchild posted on the refrigerator. After training, the woman was able to recall the name of her grandchild five days later. Research and application The notion that spaced repetition could be used for improving learning was first proposed in the book Psychology of Study by Prof. C. A. Mace in 1932: "Perhaps the most important discoveries are those which relate to the appropriate distribution of the periods of study... Acts of revision should be spaced in gradually increasing intervals, roughly intervals of one day, two days, four days, eight days, and so on." In 1939, H. F. Spitzer tested the effects of a type of spaced repetition on sixth-grade students in Iowa who were learning science facts. Spitzer tested over 3600 students in Iowa and showed that spaced repetition was effective. This early work went unnoticed, and the field was relatively quiet until the late 1960s when cognitive psychologists, including Melton and Landauer and Bjork, explored manipulation of repetition timing as a means to improve recall. Around the same time, Pimsleur language courses pioneered the practical application of spaced repetition theory to language learning, and in 1973 Sebastian Leitner devised his "Leitner system", an all-purpose spaced repetition learning system based on flashcards. With the increase in access to personal computers in the 1980s, spaced repetition began to be implemented with computer-assisted language learning software-based solutions (see ), enabling automated scheduling and statistic gathering, scaling to thousands of cards scheduled individually. To enable the user to reach a target level of achievement (e.g.	target level of achievement (e.g. 90% of all material correctly recalled at any given time point), the software adjusts the repetition spacing interval. Material that is hard appears more often and material that is easy less often, with difficulty defined according to the ease with which the user is able to produce a correct response. The data behind this initial research indicated that an increasing space between rehearsals (expanding) would yield a greater percentage of accuracy at test points. Spaced repetition with expanding intervals is believed to be so effective because with each expanded interval of repetition it becomes more difficult to retrieve the information because of the time elapsed between test periods; this creates a deeper level of processing of the learned information in long-term memory at each point. Another reason that the expanding repetition model is believed to work so effectively is that the first test happens early on in the rehearsal process. The purpose of this is to increase repetition success. By having a first test that followed initial learning with a successful repetition, people are more likely to remember this successful repetition on the following tests. Although expanding retrieval is commonly associated with spaced repetition, a uniform retrieval schedule is also a form of spaced repetition procedure. Spaced repetition is typically studied through the use of memorizing facts. Traditionally speaking, it has not been applied to fields that required some manipulation or thought beyond simple factual/semantic information. A more recent study has shown that spaced repetition can benefit tasks such as solving math problems. In a study conducted by Pashler, Rohrer, Cepeda, and Carpenter, participants had to learn a simple math principle in either a spaced or massed retrieval schedule. The participants given the spaced repetition learning tasks showed higher scores on a final test distributed after their final practice session. This is unique in the sense that it shows spaced repetition can be used to not only remember simple facts or contextual data but it can also be used in fields, such as math, where manipulation and the use of particular principles or formulas (e.g. y = mx + b) is necessary. These researchers also found that it is beneficial for feedback to be applied when administering the tests. When a participant gave a wrong response, they were likely to get it correct on the following tests if the researcher gave them the correct answer after a delayed period. Spaced repetition is a useful tool for learning that is relevant to many domains such as fact learning or mathematics, and many different tasks (expanding or uniform retrieval). Many studies over the years have contributed to the use and implementation of spaced repetition, and it still remains a subject of interest for many researchers. Algorithms There are several families of algorithms for scheduling spaced repetition: Neural networks based Leitner system: 5 levels and an arbitrary number of stages SM-family of algorithms (SuperMemo): SM-0 (a paper implementation) to SM-18 (in SuperMemo 18) Some have theorized that the precise length of intervals does not have a great impact on algorithm effectiveness, although it has been suggested by others that the interval (expanded interval vs. fixed interval, etc.) is quite important. The experimental results regarding this point are mixed. Implementations Software Most spaced repetition software (SRS) is modeled after the manual style of learning with physical flashcards: items to memorize are entered into the program as question-answer pairs. When a pair is due to be reviewed, the question is displayed on a screen, and the user must attempt to answer. After answering, the user manually reveals the answer and then tells the program (subjectively) how difficult answering was. The program schedules pairs based on spaced repetition algorithms. Without a computer program, the user has to schedule physical flashcards; this is time-intensive and limits users to simple algorithms like the Leitner system. Further refinements with regard to software: Questions and/or answers can be a sound file to train recognition of spoken words. Automatic generation of pairs (e.g. for vocabulary, it is useful to generate three question-pairs: written foreign word, its pronunciation and its meaning, but data only has to be entered once.) Additional information retrieved automatically is available, such as example sentences containing a word. Opportunities to combine spaced repetition with online community functions, e.g. sharing courses. Flash cards The Leitner system is a widely used method of efficiently using flashcards that was proposed by the German science journalist Sebastian Leitner in the 1970s. It is a simple implementation of the principle of spaced repetition, where cards are reviewed at increasing intervals. In this method, flashcards are sorted into groups according to how well the learner knows each one in Leitner's learning box. The learners try to recall the solution written on a flashcard. If they succeed, they send the card to the next group. If they fail, they send it back to the first group. Each succeeding group has a longer period of time before the learner is required to revisit the cards. In Leitner's original method, published in his book (How to learn to learn), the schedule of repetition was governed by the size of the partitions in the learning box. These were 1, 2, 5, 8 and 14 cm. Only when a partition became full was the learner to review some of the cards it contained, moving them forward or back, depending on whether they remembered them. Problems and contradictions Spaced repetition with expanding intervals has long been argued to be the most beneficial version of this learning procedure, but current research, which compared repetition procedures, has shown the difference between expanding repetition and uniform retrieval is either very little to nonexistent. Some researchers have found cases where uniform retrieval is better than expanding. The main speculation for this range of results is that prior research has not accounted for the possibility of their results being affected by either the spacing condition or the number of successful repetitions during study periods. There are two forms of implementing spacing in spaced repetition. The first form is absolute spacing. Absolute spacing is the measurement of all the trials within the learning and testing periods. An example of this would be that participants would study for a total of thirty trial periods, but the spacing of these trials can either be expanding or uniform. The second form is called relative spacing. Relative spacing measures the spacing of trials between each test. An example of this would be if the absolute spacing was thirty, participants
Piotr Woźniak in Poland from 1985 to the present. It is based on research into long-term memory, and is a practical application of the spaced repetition learning method that has been proposed for efficient instruction by a number of psychologists as early as in the 1930s. The method is available as a computer program for Windows, Windows CE, Windows Mobile, (Pocket PC), Palm OS (PalmPilot), etc. Course software by the same company (SuperMemo World) can also be used in a web browser or even without a computer. The desktop version of SuperMemo (since v. 2002) supports incremental reading, as well as traditional creation of question and answer flashcards. Software implementation The SuperMemo program stores a database of questions and answers constructed by the user. When reviewing information saved in the database, the program uses the SuperMemo algorithm to decide what questions to show the user. The user then answers the question and rates their relative ease of recall - with grades of 1 to 5 (1 is the hardest, 5 is the easiest) - and their rating is used to calculate how soon they should be shown the question again. While the exact algorithm varies with the version of SuperMemo, in general, items that are harder to remember show up more frequently. Besides simple text questions and answers, the latest version of SuperMemo supports images, video, and HTML questions and answers. Since 2002, SuperMemo has had a unique set of features that distinguish it from other spaced repetition programs, called incremental reading (IR or "increading"). Whereas earlier versions were built around users entering information they wanted to use, using IR, users can import text that they want to learn from. The user reads the text inside of SuperMemo, and tools are provided to bookmark one's location in the text and automatically schedule it to be revisited later, extract valuable information, and turn extracts into questions for the user to learn. By automating the entire process of reading and extracting knowledge to be remembered all in the same program, time is saved from having to manually prepare information, and insights into the nature of learning can be used to make the entire process more natural for the user. Furthermore, since the process of extracting knowledge can often lead to the extraction of more information than can actually be feasibly remembered, a priority system is implemented that allows the user to ensure that the most important information is remembered when they can't review all information in the system. Algorithms The specific algorithms SuperMemo uses have been published, and re-implemented in other programs. Different	algorithms have been used; SM–0 refers to the original (non-computer-based) algorithm, while SM-2 refers to the original computer-based algorithm released in the 1987 (used in SuperMemo versions 1.0 through 3.0, referred to as SM-2 because SuperMemo version 2 was the most popular of these). Subsequent versions of the software have claimed to further optimize the algorithm, though there is little research on whether these modifications are beneficial to learning. Piotr Woźniak, the developer of SuperMemo algorithms, released the description for SM-5 in a paper titled Optimization of repetition spacing in the practice of learning. Little detail is specified in the algorithms released later than that. In 1995, SM-8, which capitalized on data collected by users of SuperMemo 6 and SuperMemo 7 and added a number of improvements that strengthened the theoretical validity of the function of optimum intervals and made it possible to accelerate its adaptation, was introduced in SuperMemo 8. In 2002, SM-11, the first SuperMemo algorithm that was resistant to interference from the delay or advancement of repetitions was introduced in SuperMemo 11 (aka SuperMemo 2002). In 2005, SM-11 was tweaked to introduce boundaries on A and B parameters computed from the Grade vs. Forgetting Index data. In 2011, SM-15, which notably eliminated two weaknesses of SM-11 that would show up in heavily overloaded collections with very large item delays, was introduced in Supermemo 15. In 2016, SM-17, the first version of the algorithm to incorporate the two component model of memory, was introduced in SuperMemo 17. The latest version of the SuperMemo algorithm is SM-18, released in 2019. Description of SM-2 algorithm The first computer-based SuperMemo algorithm (SM-2) tracks three properties for each card being studied: The repetition number n, which is the number of times the card has been successfully recalled (meaning it was given a grade ≥ 3) in a row since the last time it was not. The easiness factor EF, which loosely indicates how "easy" the card is (more precisely, it determines how quickly the inter-repetition interval grows). The initial value of EF is 2.5. The inter-repetition interval I, which is the length of time (in days) SuperMemo will wait after the previous review before asking the user to review the card again. Every time the user starts a review session, SuperMemo provides the user with the cards whose last review occurred at least I days ago. For each review, the user tries to recall the information and (after being shown the correct answer) specifies a grade q (from 0 to 5) indicating a self-evaluation the quality of their response, with each grade having the following meaning: 0: "Total blackout", complete failure to recall the information. 1: Incorrect response, but upon seeing the correct answer it felt familiar. 2: Incorrect response, but upon seeing the correct answer it seemed easy to remember. 3: Correct response, but required significant effort to recall. 4:
mortality was high and he was soon the oldest survivor. He was baptised at St Bride's Church on 3 March 1633. Pepys did not spend all of his infancy in London; for a while, he was sent to live with nurse Goody Lawrence at Kingsland, just north of the city. In about 1644, Pepys attended Huntingdon Grammar School before being educated at St Paul's School, London, c. 1646–1650. He attended the execution of Charles I in 1649. In 1650, he went to the University of Cambridge, having received two exhibitions from St Paul's School (perhaps owing to the influence of Sir George Downing, who was chairman of the judges and for whom he later worked at the Exchequer) and a grant from the Mercers' Company. In October, he was admitted as a sizar to Magdalene College; he moved there in March 1651 and took his Bachelor of Arts degree in 1654. Later in 1654 or early in 1655, he entered the household of one of his father's cousins, Sir Edward Montagu, who was later dubbed the 1st Earl of Sandwich. When he was 22, Pepys married fourteen-year-old Elisabeth de St Michel, a descendant of French Huguenot immigrants, first in a religious ceremony on 10 October 1655 and later in a civil ceremony on 1 December 1655 at St Margaret's, Westminster. Illness From a young age, Pepys suffered from bladder stones in his urinary tract—a condition from which his mother and brother John also later suffered. He was almost never without pain, as well as other symptoms, including "blood in the urine" (hematuria). By the time of his marriage, the condition was very severe. In 1657 Pepys decided to undergo surgery; not an easy option, as the operation was known to be especially painful and hazardous. Nevertheless, Pepys consulted surgeon Thomas Hollier and, on 26 March 1658, the operation took place in a bedroom in the house of Pepys's cousin Jane Turner. Pepys's stone was successfully removed and he resolved to hold a celebration on every anniversary of the operation, which he did for several years. However, there were long-term effects from the operation. The incision on his bladder broke open again late in his life. The procedure may have left him sterile, though there is no direct evidence for this, as he was childless before the operation. In mid-1658 Pepys moved to Axe Yard, near the modern Downing Street. He worked as a teller in the Exchequer under George Downing. Diary [[File:Samuel Pepys bookplate 1.jpg\|thumb\|Samuel Pepys's bookplate. The motto reads Mens cujusque is est Quisque – "Mind Makes the Man".<ref>Edmund Lodge, The Peerage and Baronetage of the British Empire", Published 1861 (page 835)</ref>]] On 1 January 1660 ("1 January 1659/1660" in contemporary terms), Pepys began to keep a diary. He recorded his daily life for almost ten years. This record of a decade of Pepys's life is more than a million words long and is often regarded as Britain's most celebrated diary. Pepys has been called the greatest diarist of all time due to his frankness in writing concerning his own weaknesses and the accuracy with which he records events of daily British life and major events in the 17th century. Pepys wrote about the contemporary court and theatre (including his amorous affairs with the actresses), his household, and major political and social occurrences. Historians have been using his diary to gain greater insight and understanding of life in London in the 17th century. Pepys wrote consistently on subjects such as personal finances, the time he got up in the morning, the weather, and what he ate. He wrote at length about his new watch which he was very proud of (and which had an alarm, a new accessory at the time), a country visitor who did not enjoy his time in London because he felt that it was too crowded, and his cat waking him up at one in the morning. Pepys's diary is one of a very few sources which provides such length in details of everyday life of an upper-middle-class man during the seventeenth century. Aside from day-to-day activities, Pepys also commented on the significant and turbulent events of his nation. England was in disarray when he began writing his diary. Oliver Cromwell had died just a few years before, creating a period of civil unrest and a large power vacuum to be filled. Pepys had been a strong supporter of Cromwell, but he converted to the Royalist cause upon the Protector's death. He was on the ship that returned Charles II to England to take up his throne, and gave first-hand accounts of other significant events from the early years of the Restoration, such as the coronation of Charles II, the Great Plague, the Great Fire of London and the Anglo–Dutch Wars. Pepys did not plan on his contemporaries ever seeing his diary, which is evident from the fact that he wrote in shorthand and sometimes in a "code" of various Spanish, French, and Italian words (especially when describing his illicit affairs). However, Pepys often juxtaposed profanities in his native English amidst his "code" of foreign words, a practice which would reveal the details to any casual reader. He did intend future generations to see the diary, as evidenced by its inclusion in his library and its catalogue before his death along with the shorthand guide he used and the elaborate planning by which he ensured his library survived intact after his death. The women whom he pursued, his friends, and his dealings are all laid out. His diary reveals his jealousies, insecurities, trivial concerns, and his fractious relationship with his wife. It has been an important account of London in the 1660s. The juxtaposition of his commentary on politics and national events, alongside the very personal, can be seen from the beginning. His opening paragraphs, written in January 1660, begin: The entries from the first few months were filled with news of General George Monck's march on London. In April and May of that year, he was encountering problems with his wife, and he accompanied Montagu's fleet to the Netherlands to bring Charles II back from exile. Montagu was made Earl of Sandwich on 18 June, and Pepys secured the position of Clerk of the Acts to the Navy Board on 13 July. As secretary to the board, Pepys was entitled to a £350 annual salary plus the various gratuities and benefits that came with the job—including bribes. He rejected an offer of £1,000 for the position from a rival and soon afterwards moved to official accommodation in Seething Lane in the City of London. Pepys stopped writing his diary in 1669. His eyesight began to trouble him and he feared that writing in dim light was damaging his eyes. He did imply in his last entries that he might have others write his diary for him, but doing so would result in a loss of privacy and it seems that he never went through with those plans. In the end, Pepys lived another 34 years without going blind, but he never took to writing his diary again. However, Pepys dictated a journal for two months in 1669–70 as a record of his dealings with the Commissioners of Accounts at that period. He also kept a diary for a few months in 1683 when he was sent to Tangier, Morocco as the most senior civil servant in the navy, during the English evacuation. The diary mostly covers work-related matters. Public life On the Navy Board, Pepys proved to be a more able and efficient worker than colleagues in higher positions. This often annoyed Pepys and provoked much harsh criticism in his diary. Among his colleagues were Admiral Sir William Penn, Sir George Carteret, Sir John Mennes and Sir William Batten. Pepys learned arithmetic from a private tutor and used models of ships to make up for his lack of first-hand nautical experience, and ultimately came to play a significant role in the board's activities. In September 1660, he was made a Justice of the Peace; on 15 February 1662, Pepys was admitted as a Younger Brother of Trinity House; and on 30 April, he received the freedom of Portsmouth. Through Sandwich, he was involved in the administration of the short-lived English colony at Tangier. He joined the Tangier committee in August 1662 when the colony was first founded and became its treasurer in 1665. In 1663, he independently negotiated a £3,000 contract for Norwegian masts, demonstrating the freedom of action that his superior abilities allowed. He was appointed to a commission of the royal fishery on 8 April 1664. Pepys's job required him to meet many people to dispense money and make contracts. He often laments how he "lost his labour" having gone to some appointment at a coffee house or tavern, only to discover that the person whom he was seeking was not there. These occasions were a constant source of frustration to Pepys. Major events Pepys's diary provides a first-hand account of the Restoration, and includes detailed accounts of several major events of the 1660s, along with the lesser known diary of John Evelyn. In particular, it is an invaluable source for the study of the Second Anglo-Dutch War of 1665–7, the Great Plague of 1665, and the Great Fire of London in 1666. In relation to the Plague and Fire, C. S. Knighton has written: "From its reporting of these two disasters to the metropolis in which he thrived, Pepys's diary has become a national monument." Robert Latham, editor of the definitive edition of the diary, remarks concerning the Plague and Fire: "His descriptions of both—agonisingly vivid—achieve their effect by being something more than superlative reporting; they are written with compassion. As always with Pepys it is people, not literary effects, that matter." Second Anglo-Dutch War In early 1665, the start of the Second Anglo-Dutch War placed great pressure on Pepys. His colleagues were either engaged elsewhere or incompetent, and Pepys had to conduct a great deal of business himself. He excelled under the pressure, which was extreme due to the complexity and under-funding of the Royal Navy. At the outset, he proposed a centralised approach to supplying the fleet. His idea was accepted, and he was made surveyor-general of victualling in October 1665. The position brought a further £300 a year. Pepys wrote about the Second Anglo-Dutch War: "In all things, in wisdom, courage, force and success, the Dutch have the best of us and do end the war with victory on their side". And King Charles II said: "Don't fight the Dutch, imitate them". In 1667, with the war lost, Pepys helped to discharge the navy. The Dutch had defeated England on open water and now began to threaten English soil itself. In June 1667, they conducted their Raid on the Medway, broke the defensive chain at Gillingham, and towed away the , one of the Royal Navy's most important ships. As he had done during the Fire and the Plague, Pepys again removed his wife and his gold from London. The Dutch raid was a major concern in itself, but Pepys was personally placed under a different kind of pressure: the Navy Board and his role as Clerk of the Acts came under scrutiny from the public and from Parliament. The war ended in August and, on 17 October, the House of Commons created a committee of "miscarriages". On 20 October, a list was demanded from Pepys of ships and commanders at the time of the division of the fleet in 1666. However, these demands were actually quite desirable for him, as tactical and strategic mistakes were not the responsibility of the Navy Board. The Board did face some allegations regarding the Medway raid, but they could exploit the criticism already attracted by commissioner of Chatham Peter Pett to deflect criticism from themselves. The committee accepted this tactic when they reported in February 1668. The Board was, however, criticised for its use of tickets to pay seamen. These tickets could only be exchanged for cash at the Navy's treasury in London. Pepys made a long speech at the bar of the Commons on 5 March 1668 defending this practice. It was, in the words of C. S. Knighton, a "virtuoso performance". The commission was followed by an investigation led by a more powerful authority, the commissioners of accounts. They met at Brooke House, Holborn and spent two years scrutinising how the war had been financed. In 1669, Pepys had to prepare detailed answers to the committee's eight "Observations" on the Navy Board's conduct. In 1670, he was forced to defend his own role. A seaman's ticket with Pepys's name on it was produced as incontrovertible evidence of his corrupt dealings but, thanks to the intervention of the king, Pepys emerged from the sustained investigation relatively unscathed. Great Plague Outbreaks of plague were not unusual events in London; major epidemics had occurred in 1592, 1603, 1625 and 1636. Furthermore, Pepys was not among the group of people who were most at risk. He did not live in cramped housing, he did not routinely mix with the poor, and he was not required to keep his family in London in the event of a crisis. It was not until June 1665 that the unusual seriousness of the plague became apparent, so Pepys's activities in the first five months of 1665 were not significantly affected by it. Claire Tomalin wrote that 1665 was, to Pepys, one of the happiest years of his life. He worked very hard that year, and the outcome was that he quadrupled his fortune. In his annual summary on 31 December, he wrote, "I have never lived so merrily (besides that I never got so much) as I have done this plague time". Nonetheless, Pepys was certainly concerned about the plague. On 16 August he wrote: He also chewed tobacco as a protection against infection, and worried that wig-makers might be using hair from the corpses as a raw material. Furthermore, it was Pepys who suggested that the Navy Office should evacuate to Greenwich, although he did offer to remain in town himself. He later took great pride in his stoicism. Meanwhile, Elisabeth Pepys was sent to Woolwich. She did	about the Second Anglo-Dutch War: "In all things, in wisdom, courage, force and success, the Dutch have the best of us and do end the war with victory on their side". And King Charles II said: "Don't fight the Dutch, imitate them". In 1667, with the war lost, Pepys helped to discharge the navy. The Dutch had defeated England on open water and now began to threaten English soil itself. In June 1667, they conducted their Raid on the Medway, broke the defensive chain at Gillingham, and towed away the , one of the Royal Navy's most important ships. As he had done during the Fire and the Plague, Pepys again removed his wife and his gold from London. The Dutch raid was a major concern in itself, but Pepys was personally placed under a different kind of pressure: the Navy Board and his role as Clerk of the Acts came under scrutiny from the public and from Parliament. The war ended in August and, on 17 October, the House of Commons created a committee of "miscarriages". On 20 October, a list was demanded from Pepys of ships and commanders at the time of the division of the fleet in 1666. However, these demands were actually quite desirable for him, as tactical and strategic mistakes were not the responsibility of the Navy Board. The Board did face some allegations regarding the Medway raid, but they could exploit the criticism already attracted by commissioner of Chatham Peter Pett to deflect criticism from themselves. The committee accepted this tactic when they reported in February 1668. The Board was, however, criticised for its use of tickets to pay seamen. These tickets could only be exchanged for cash at the Navy's treasury in London. Pepys made a long speech at the bar of the Commons on 5 March 1668 defending this practice. It was, in the words of C. S. Knighton, a "virtuoso performance". The commission was followed by an investigation led by a more powerful authority, the commissioners of accounts. They met at Brooke House, Holborn and spent two years scrutinising how the war had been financed. In 1669, Pepys had to prepare detailed answers to the committee's eight "Observations" on the Navy Board's conduct. In 1670, he was forced to defend his own role. A seaman's ticket with Pepys's name on it was produced as incontrovertible evidence of his corrupt dealings but, thanks to the intervention of the king, Pepys emerged from the sustained investigation relatively unscathed. Great Plague Outbreaks of plague were not unusual events in London; major epidemics had occurred in 1592, 1603, 1625 and 1636. Furthermore, Pepys was not among the group of people who were most at risk. He did not live in cramped housing, he did not routinely mix with the poor, and he was not required to keep his family in London in the event of a crisis. It was not until June 1665 that the unusual seriousness of the plague became apparent, so Pepys's activities in the first five months of 1665 were not significantly affected by it. Claire Tomalin wrote that 1665 was, to Pepys, one of the happiest years of his life. He worked very hard that year, and the outcome was that he quadrupled his fortune. In his annual summary on 31 December, he wrote, "I have never lived so merrily (besides that I never got so much) as I have done this plague time". Nonetheless, Pepys was certainly concerned about the plague. On 16 August he wrote: He also chewed tobacco as a protection against infection, and worried that wig-makers might be using hair from the corpses as a raw material. Furthermore, it was Pepys who suggested that the Navy Office should evacuate to Greenwich, although he did offer to remain in town himself. He later took great pride in his stoicism. Meanwhile, Elisabeth Pepys was sent to Woolwich. She did not return to Seething Lane until January 1666, and was shocked by the sight of St Olave's churchyard, where 300 people had been buried. Great Fire of London In the early hours of 2 September 1666, Pepys was awakened by Jane the maid, his servant, who had spotted a fire in the Billingsgate area. He decided that the fire was not particularly serious and returned to bed. Shortly after waking, his servant returned and reported that 300 houses had been destroyed and that London Bridge was threatened. Pepys went to the Tower of London to get a better view. Without returning home, he took a boat and observed the fire for over an hour. In his diary, Pepys recorded his observations as follows: The wind was driving the fire westward, so he ordered the boat to go to Whitehall and became the first person to inform the king of the fire. According to his entry of 2 September 1666, Pepys recommended to the king that homes be pulled down in the path of the fire in order to stem its progress. Accepting this advice, the king told him to go to Lord Mayor Thomas Bloodworth and tell him to start pulling down houses. Pepys took a coach back as far as St Paul's Cathedral before setting off on foot through the burning city. He found the Lord Mayor, who said, "Lord! what can I do? I am spent: people will not obey me. I have been pulling down houses; but the fire overtakes us faster than we can do it." At noon, he returned home and "had an extraordinary good dinner, and as merry, as at this time we could be", before returning to watch the fire in the city once more. Later, he returned to Whitehall, then met his wife in St. James's Park. In the evening, they watched the fire from the safety of Bankside. Pepys writes that "it made me weep to see it". Returning home, Pepys met his clerk Tom Hayter who had lost everything. Hearing news that the fire was advancing, he started to pack up his possessions by moonlight. A cart arrived at 4 a.m. on 3 September and Pepys spent much of the day arranging the removal of his possessions. Many of his valuables, including his diary, were sent to a friend from the Navy Office at Bethnal Green. At night, he "fed upon the remains of yesterday's dinner, having no fire nor dishes, nor any opportunity of dressing any thing." The next day, Pepys continued to arrange the removal of his possessions. By then, he believed that Seething Lane was in grave danger, so he suggested calling men from Deptford to help pull down houses and defend the king's property. He described the chaos in the city and his curious attempt at saving his own goods: Pepys had taken to sleeping on his office floor; on Wednesday, 5 September, he was awakened by his wife at 2 a.m. She told him that the fire had almost reached All Hallows-by-the-Tower and that it was at the foot of Seething Lane. He decided to send her and his gold—about £2,350—to Woolwich. In the following days, Pepys witnessed looting, disorder, and disruption. On 7 September, he went to Paul's Wharf and saw the ruins of St Paul's Cathedral, of his old school, of his father's house, and of the house in which he had had his stone removed. Despite all this destruction, Pepys's house, office, and diary were saved. Personal life The diary gives a detailed account of Pepys's personal life. He was fond of wine, plays, and the company of other people. He also spent time evaluating his fortune and his place in the world. He was always curious and often acted on that curiosity, as he acted upon almost all his impulses. Periodically, he would resolve to devote more time to hard work instead of leisure. For example, in his entry for New Year's Eve, 1661, he writes: "I have newly taken a solemn oath about abstaining from plays and wine…" The following months reveal his lapses to the reader; by 17 February, it is recorded, "Here I drank wine upon necessity, being ill for the want of it." Pepys was one of the most important civil servants of his age, and was also a widely cultivated man, taking an interest in books, music, the theatre and science. Aside from English, he was fluent in French and read many texts in Latin. His favourite author was Virgil. He was passionately interested in music; he composed, sang, and played for pleasure, and even arranged music lessons for his servants. He played the lute, viol, violin, flageolet, recorder and spinet to varying degrees of proficiency. He was also a keen singer, performing at home, in coffee houses, and even in Westminster Abbey. He and his wife took flageolet lessons from master Thomas Greeting. He also taught his wife to sing and paid for dancing lessons for her (although these stopped when he became jealous of the dancing master). He was known to be brutal to his servants, once beating a servant Jane with a broom until she cried. He kept a boy servant whom he frequently beat with a cane, a birch rod, a whip or a rope's end. Pepys was an investor in the Company of Royal Adventurers Trading to Africa, which held the Royal monopoly on trading along the west coast of Africa in gold, silver, ivory and slaves. Sexual relations Propriety did not prevent him from engaging in a number of extramarital liaisons with various women that were chronicled in his diary, often in some detail when relating the intimate details. The most dramatic of these encounters was with Deborah Willet, a young woman engaged as a companion for Elisabeth Pepys. On 25 October 1668, Pepys was surprised by his wife as he embraced Deb Willet; he writes that his wife "coming up suddenly, did find me imbracing the girl con [with] my hand sub [under] su [her] coats; and endeed I was with my main [hand] in her cunny. I was at a wonderful loss upon it and the girl also...." Following this event, he was characteristically filled with remorse, but (equally characteristically) continued to pursue Willet after she had been dismissed from the Pepys household. Pepys also had a habit of fondling the breasts of his maid Mary Mercer while she dressed him in the morning. Pepys may also have dallied with a leading actress of the Restoration period, Mary Knep. "Mrs Knep was the wife of a Smithfield horsedealer, and the mistress of Pepys"—or at least "she granted him a share of her favours". Scholars disagree on the full extent of the Pepys/Knep relationship, but much of later generations' knowledge of Knep comes from the diary. Pepys first met Knep on 6 December 1665. He described her as "pretty enough, but the most excellent, mad-humoured thing, and sings the noblest that I ever heard in my life." He called her husband "an ill, melancholy, jealous-looking fellow" and suspected him of abusing his wife. Knep provided Pepys with backstage access and was a conduit for theatrical and social gossip. When they wrote notes to each other, Pepys signed himself "Dapper Dickey", while Knep was "Barbry Allen" (a popular song that was an item in her musical repertory). Pepys reference to purchasing the pornographic book L'Escole des Filles appears to be the first English reference to pornography. He writes in his diary that it was a "mighty lewd book," and burned it after reading it. Text of the diary The diary was written in one of the many standard forms of shorthand used in Pepys's time, in this case called tachygraphy and devised by Thomas Shelton. It is clear from its content that it was written as a purely personal record of his life and not for publication, yet there are indications that Pepys took steps to preserve the bound manuscripts of his diary. He wrote it out in fair copy from rough notes, and he also had the loose pages bound into six volumes, catalogued them in his library with all his other books, and is likely to have suspected that eventually someone would find them interesting. Simplified Pepys family tree This tree summarizes, in a more compact form and with a few additional details, trees published elsewhere in a box-like form.Latham & Matthews (1970–83), Vol. X – Companion. It is meant to help the reader of the Diary and also integrates some biographical informations found in the same sources. William Pepys of Cottenham (Cambs.) (? – 1519) Thomas Pepys Richard Pepys (? – c. 1571) William Pepys of Norwich, draper (1561 – c. 1639) Richard Pepys of London, upholsterer (? – 1679) John Pepys of South Creak (Norf.) (? – 1542) Thomas Pepys (? – 1569) Jerome Pepys (1548–1634) John Pepys of Ashtead (Surrey), man of business to Chief Justice Edward Coke (1576–1652) +(1610)+ Anne Walpole Edward Pepys of Broomsthorpe (Norf.), lawyer (1617–1663) + Elizabeth Walpole Elizabeth Pepys + Thomas Dyke Jane Pepys (“Madam Turner”) (1623–1686) +(1650)+ John Turner, Yorkshire lawyer (1631–1689) Charles Turner + Margaret Cholmley Theophila Turner (“The”) (1652–1702) +(1673)+ Sir Arthur Harris, 1st Baronet, of Stowford, M.P. for Okehampton (c. 1650 – 1686) William Turner + Mary Foulis Elizabeth Turner (“Betty”) + William Hooker William Pepys of Cottenham (Cambs.) John Pepys of Cottenham and Impington (Cambs.) (? – 1589) (1) + ? ? (2) + Edith Talbot (? – 1583) John Pepys 1 (? – 1604) + Elizabeth Bendish of Essex Sir Richard Pepys, M.P. for Sudbury and Lord Chief Justice of Ireland (1589–1659) (1) +(1620)+ Judith Cutte (2) + Mary Gosnold Richard Pepys of Ashen (Essex), lawyer (? – 1664) Samuel Pepys of Dublin, clergyman Elizabeth Pepys + Thomas Strudwick, confectioner Judith Pepys (? – 1664) + Benjamin Scott, pewterer (? – 1664) Thomas Pepys (“the Black”) 1 (? – 1606) + Mary Day Robert Pepys of Brampton (Hunts.), bailiff at Hinchingbrooke (? – 1661) + Anne, widow Trice Thomas Pepys of St Alphage (1595–1676) + Mary Syvret [Chiveret] Thomas Pepys (“the turner”), trader with the W. Indies +(1664)+ Elizabeth Howes Charles Pepys (“the joiner”), Master-Joiner with the Chatham yard (c. 1632 – c. 1701) +(1662)+ Joan, widow Smith Mary Pepys (? – 1667) +(1662)+ Samuel de Santhune, weaver of Huguenot origin Jane Pepys (? – 1666) + John Perkin of Parson Drove (Cambs.) Jane Perkin Frank Perkin, miller and fiddler Mary Pepys (1597 – ?) + Robert Holcroft John Holcroft Edith Pepys (“Aunt Bell”) (1599–1665) + John Bell John Pepys, tailor in Salisbury Court (1601–1680) +(1626)+ Margaret Kite, washmaid (? – 1667) Mary Pepys (1627–1640) Paulina Pepys (1628–1632) Esther Pepys (1630–1631) John Pepys (1632–1640) SAMUEL PEPYS, diarist, naval administrator, and M.P. for Castle Rising and Harwich (1633–1703) +(1655)+ Élisabeth de Saint-Michel, born from an Anglo-French wedding, of Angevin gentry by her father (1640–1669) Thomas Pepys (“Tom”), tailor against his will (1634–1664) Elizabeth Taylor, an illegitimate daughter with his maid Margeret Sarah Pepys (1635–1641) Jacob Pepys (1637–1637) Robert Pepys (1638–1638) Paulina Pepys (“Pall”) (1640–1689) +(1668)+ John Jackson, farmer in Ellington (Hunts.) (? – 1680) Samuel Jackson (1669 – ?) John Jackson, secretary and heir to SP (1673–1724) + Anne Edgeley John Jackson (? – 1780) 1 other son and 2 daughters Anne Jackson + Brabazon Hallows Paulina Jackson + Admiral R. Collins Frances Jackson (1722–1769) +(1747)+ John Cockerell of Bishops Hull (Somer.) (1714–1767) John Cockerell Charles Cockerell Samuel Pepys Cockerell, architect (1754–1827) Charles Robert Cockerell, architect (1788–1863) +(1828)+ Anna Rennie (1803–1872) Frederick Pepys Cockerell, architect (1833–1878) +(1867)+ Mary Mulock 6 children 9 other children 2 other children dead in infancy John Pepys, naval administrator, unmarr. (1642–1677) Thomas Pepys (“the Red”) 1 of Hatcham Barnes (Surrey) (? – 1615) + Kezia ? Thomas Pepys (“the Executor”), lawyer (1611–1675) (1) +(1654)+ Anne Cope (2) +(1660)+ Ursula Stapleton (? – c. 1693) 1 son and 1 daughter by the second wedding Elizabeth Pepys +(1633)+ Percival Angier, business man (? – 1665) Elizabeth Pepys 1 +(1593)+ Henry Alcock issue Apollo Pepys 1 (1576–1645) Paulina Pepys 2 (1581–1638) +(1618)+ Sidney Montagu (? – 1644) Elizabeth Montagu (1620 – ?) +(1638)+ Sir Gilbert Pickering, 1st Baronet, Lord Chamberlain to Oliver and Richard Cromwell (1613–1668) Elizabeth Pickering +(1668)+ John Creed, secretary to Edward Montagu and SP's principal rival (? – 1701) 11 children 11 other children Henry Montagu (1622–1625) Edward Montagu, 1st Earl of Sandwich (“My Lord”) (1625–1672) +(1642)+ Jemima Crew (“My Lady”) (1625–1674) Jemima Montagu (“Lady Jem”) (1646–1671) +(1665)+ Philip Carteret, commissioned lieutenant in the Navy (1643–1672) George Carteret, 1st Baron Carteret, (1667–1695) + Lady Grace Granville (1654–1744) John Carteret, 2nd Earl Granville, Prime Minister to George II (1690–1763) + Lady Frances Worsley 2 other sons Edward Montagu, 2nd Earl of Sandwich (“Ned”) (1648–1688) +(1668)+ Lady Anne Boyle (? – 1671) descent of the Earls of Sandwich Paulina Montagu (1649–1669) Sidney Montagu, later Wortley-Montagu (1650–1727) + ? ?, Yorkshire heiress issue Anne Montagu (1653–1729) (1) +(1671)+ Richard Edgcumbe (1640–1688) (2) + Christopher Montagu Oliver Montagu (1655–1693) John Montagu, Dean of Durham (1655–1729) Charles Montagu (1658–1721) (1) + Elizabeth Forester (2) + Sarah Rogers issue by both weddings Catherine Montagu (1661–1757) (1) + Nicholas Bacon, M.P. for Ipswich (1622–1687) (2) + Balthazar Gardeman, clergyman James Montagu (1664 – ?) Talbot Pepys 2 of Impington (Cambs.), Recorder and M.P. for Cambridge, remarried 3 times (1583–1666) + Beatrice Castell Roger Pepys of Impington (Cambs.), Recorder and M.P. for Cambridge (1617–1688) (1) + Anne Banks (2) +(c. 1646)+ Barbara Bacon (? – 1657) (3) + Parnell Duke (4) +(1669)+ Esther, widow Dickenson (“the good-humoured fat widow”) Talbot Pepys 2 (1647–1681) Barbara Pepys (“Bab”) 2 (1649–1689) +(1674)+ Dr Thomas Gale, High Master of St Paul's School and Dean of York (1635–1702) Charles Gale Thomas Gale Elizabeth Gale Roger Gale, antiquary (1672–1744) Samuel Gale, antiquary (1682–1754) Elizabeth Pepys (“Betty”) 2 (1651–1716) +(1680)+ Charles Long, fellow of Caius College and rector of Risby (Suff.) John Pepys 3 Dr John Pepys, fellow of Trinity Hall and lawyer (1618–1692) + Catherine, widow Hobson Dr Thomas Pepys, physician, poorly appreciated by SP, unmarr. Paulina Pepys + Hammond Claxton of Booton (Norf.) After the diary Pepys's health suffered from the long hours that he worked throughout the period of the diary. Specifically, he believed that his eyesight had been affected by his work. He reluctantly concluded in his last entry, dated 31 May 1669, that he should completely stop writing for the sake of his eyes, and only dictate to his clerks from then on, which meant that he could no longer keep his diary. Pepys and his wife took a holiday to France and the Low Countries in June–October 1669; on their return, Elisabeth fell ill and died on 10 November 1669. Pepys erected a monument to her in the church of St Olave's, Hart Street, London. Pepys never remarried, but he did have a long-term housekeeper named Mary Skinner who was assumed by many of his contemporaries to be his mistress and sometimes referred to as Mrs. Pepys. In his will, he left her an annuity of £200 and many of his possessions. Member of Parliament and Secretary of the Admiralty In 1672 he became an Elder Brother of Trinity House and served in this capacity until 1689; he was Master of Trinity House in 1676–1677 and again in 1685–1686. In 1673 he was promoted to Secretary of the Admiralty Commission and elected MP for Castle Rising in Norfolk. In 1673 he was involved with the establishment of the Royal Mathematical School at Christ's Hospital, which was to train 40 boys annually in navigation, for the benefit of the Royal Navy and the English Merchant Navy. In 1675 he was appointed a Governor of Christ's Hospital and for many years he took a close interest in its affairs. Among his papers are two detailed memoranda on the administration of the school. In 1699, after the successful conclusion of a seven-year campaign to get the master of the Mathematical School replaced by a man who knew more about the sea, he was rewarded for his service as a Governor by being made a Freeman of the City of London. He also served as Master (without ever having been a Freeman or Liveryman) of the Clothworkers' Company (1677-8).
to thermally-induced oscillations of both it and the receptor, making it available to be broken down metabolically outside the neuron or to be reabsorbed. Enzymes within the subsynaptic membrane may inactivate/metabolize the neurotransmitter. Reuptake pumps may actively pump the neurotransmitter back into the presynaptic axon terminal for reprocessing and re-release following a later action potential. Synaptic strength The strength of a synapse has been defined by Sir Bernard Katz as the product of (presynaptic) release probability pr, quantal size q (the postsynaptic response to the release of a single neurotransmitter vesicle, a 'quantum'), and n, the number of release sites. "Unitary connection" usually refers to an unknown number of individual synapses connecting a presynaptic neuron to a postsynaptic neuron. The amplitude of postsynaptic potentials (PSPs) can be as low as 0.4 mV to as high as 20 mV. The amplitude of a PSP can be modulated by neuromodulators or can change as a result of previous activity. Changes in the synaptic strength can be short-term, lasting seconds to minutes, or long-term (long-term potentiation, or LTP), lasting hours. Learning and memory are believed to result from long-term changes in synaptic strength, via a mechanism known as synaptic plasticity. Receptor desensitization Desensitization of the postsynaptic receptors is a decrease in response to the same neurotransmitter stimulus. It means that the strength of a synapse may in effect diminish as a train of action potentials arrive in rapid succession – a phenomenon that gives rise to the so-called frequency dependence of synapses. The nervous system exploits this property for computational purposes, and can tune its synapses through such means as phosphorylation of the proteins involved. Synaptic plasticity Synaptic transmission can be changed by previous activity. These changes are called synaptic plasticity and may result in either a decrease in the efficacy of the synapse, called depression, or an increase in efficacy, called potentiation. These changes can either be long-term or short-term. Forms of short-term plasticity include synaptic fatigue or depression and synaptic augmentation. Forms of long-term plasticity include long-term depression and long-term potentiation. Synaptic plasticity can be either homosynaptic (occurring at a single synapse) or heterosynaptic (occurring at multiple synapses). Homosynaptic plasticity Homosynaptic plasticity (or also homotropic modulation) is a change in the synaptic strength that results from the history of activity at a particular synapse. This can result from changes in presynaptic calcium as well as feedback onto presynaptic receptors, i.e. a form of autocrine signaling. Homosynaptic plasticity can affect the number and replenishment rate of vesicles or it can affect the relationship between calcium and vesicle release. Homosynaptic plasticity can also be postsynaptic in nature. It can result in either an increase or decrease in synaptic strength. One example is neurons of the sympathetic nervous system (SNS), which release noradrenaline, which, besides affecting postsynaptic receptors, also affects presynaptic α2-adrenergic receptors, inhibiting further release of noradrenaline. This effect is utilized with clonidine to perform inhibitory effects on the SNS. Heterosynaptic plasticity Heterosynaptic plasticity (or also heterotropic modulation) is a change in synaptic strength that results from the activity of other neurons. Again, the plasticity can alter the number of vesicles or their replenishment rate or the relationship between calcium and vesicle release. Additionally, it could directly affect calcium influx. Heterosynaptic plasticity can also be postsynaptic in nature, affecting receptor sensitivity. One example is again neurons of the sympathetic nervous system, which release noradrenaline, which, in addition, generates an inhibitory effect on presynaptic terminals of neurons of the parasympathetic nervous system. Integration of synaptic inputs In general, if an excitatory synapse is strong enough, an action potential in the presynaptic neuron will trigger an action potential in the postsynaptic cell. In many cases the excitatory postsynaptic potential (EPSP) will not reach the threshold for eliciting an action potential. When action potentials from multiple presynaptic neurons fire simultaneously, or if a single presynaptic neuron fires at a high enough frequency, the EPSPs can overlap and summate. If enough EPSPs overlap, the summated EPSP can reach the threshold for initiating an action potential. This process is known as summation, and can serve as a high pass filter for neurons. On the other hand, a presynaptic neuron releasing an inhibitory neurotransmitter, such as GABA, can cause an inhibitory postsynaptic potential (IPSP) in the postsynaptic neuron, bringing the membrane potential farther away from the threshold, decreasing its excitability and making it more difficult for the neuron to initiate an action potential. If an IPSP overlaps with an EPSP, the IPSP can in many cases prevent the neuron from firing an action potential. In this way, the output of a neuron may depend on the input of many different neurons, each of which may have a different degree of influence, depending on the strength and type of synapse with that neuron. John Carew Eccles performed some of the important early experiments on synaptic integration, for which he received the Nobel Prize for Physiology or Medicine in 1963. Volume transmission When a neurotransmitter is released at a synapse, it reaches its highest concentration inside the narrow space of the synaptic cleft, but some of it is certain to diffuse away before being reabsorbed or broken down. If it diffuses away, it has the potential to activate receptors that are located either at other synapses or on the membrane away from any synapse. The extrasynaptic activity of a neurotransmitter is known as volume transmission. It is well established that such effects occur to some degree, but their functional importance has long been a matter of controversy. Recent work indicates that volume transmission may be the predominant mode of interaction for some special types of neurons. In the mammalian cerebral cortex, a class of neurons called neurogliaform cells can inhibit other nearby cortical neurons by releasing the neurotransmitter GABA into the extracellular space. Along the same vein, GABA released from neurogliaform cells into the extracellular space also acts on surrounding astrocytes, assigning a role for volume transmission in the control of ionic and neurotransmitter homeostasis. Approximately 78% of neurogliaform cell boutons do not form classical synapses. This may be the first definitive example of neurons communicating chemically where classical synapses are not present. Relationship to electrical synapses An electrical synapse is an electrically conductive link between two abutting neurons that is formed at a narrow gap between the pre- and postsynaptic cells, known as a gap junction. At gap junctions, cells approach within about 3.5 nm of each other, rather than the 20 to 40 nm distance that separates cells at chemical synapses. As opposed to chemical synapses, the postsynaptic potential in electrical synapses is not caused by the opening of ion channels by chemical transmitters, but rather by direct electrical coupling between both neurons. Electrical synapses are faster than chemical synapses. Electrical synapses are found throughout the nervous system, including in the retina, the reticular nucleus of the thalamus, the neocortex, and in the hippocampus. While chemical synapses are found between both excitatory and inhibitory neurons, electrical synapses are most commonly found between smaller local inhibitory neurons. Electrical synapses can exist between two axons, two dendrites, or between an axon and a dendrite. In some fish and amphibians, electrical synapses can be found within the same terminal of a chemical	reaches the synapse. The electrical depolarization of the membrane at the synapse causes channels to open that are permeable to calcium ions. Calcium ions flow through the presynaptic membrane, rapidly increasing the calcium concentration in the interior. The high calcium concentration activates a set of calcium-sensitive proteins attached to vesicles that contain a neurotransmitter chemical. These proteins change shape, causing the membranes of some "docked" vesicles to fuse with the membrane of the presynaptic cell, thereby opening the vesicles and dumping their neurotransmitter contents into the synaptic cleft, the narrow space between the membranes of the pre- and postsynaptic cells. The neurotransmitter diffuses within the cleft. Some of it escapes, but some of it binds to chemical receptor molecules located on the membrane of the postsynaptic cell. The binding of neurotransmitter causes the receptor molecule to be activated in some way. Several types of activation are possible, as described in more detail below. In any case, this is the key step by which the synaptic process affects the behavior of the postsynaptic cell. Due to thermal vibration, the motion of atoms, vibrating about their equilibrium positions in a crystalline solid, neurotransmitter molecules eventually break loose from the receptors and drift away. The neurotransmitter is either reabsorbed by the presynaptic cell, and then repackaged for future release, or else it is broken down metabolically. Neurotransmitter release The release of a neurotransmitter is triggered by the arrival of a nerve impulse (or action potential) and occurs through an unusually rapid process of cellular secretion (exocytosis). Within the presynaptic nerve terminal, vesicles containing neurotransmitter are localized near the synaptic membrane. The arriving action potential produces an influx of calcium ions through voltage-dependent, calcium-selective ion channels at the down stroke of the action potential (tail current). Calcium ions then bind to synaptotagmin proteins found within the membranes of the synaptic vesicles, allowing the vesicles to fuse with the presynaptic membrane. The fusion of a vesicle is a stochastic process, leading to frequent failure of synaptic transmission at the very small synapses that are typical for the central nervous system. Large chemical synapses (e.g. the neuromuscular junction), on the other hand, have a synaptic release probability of 1. Vesicle fusion is driven by the action of a set of proteins in the presynaptic terminal known as SNAREs. As a whole, the protein complex or structure that mediates the docking and fusion of presynaptic vesicles is called the active zone. The membrane added by the fusion process is later retrieved by endocytosis and recycled for the formation of fresh neurotransmitter-filled vesicles. An exception to the general trend of neurotransmitter release by vesicular fusion is found in the type II receptor cells of mammalian taste buds. Here the neurotransmitter ATP is released directly from the cytoplasm into the synaptic cleft via voltage gated channels. Receptor binding Receptors on the opposite side of the synaptic gap bind neurotransmitter molecules. Receptors can respond in either of two general ways. First, the receptors may directly open ligand-gated ion channels in the postsynaptic cell membrane, causing ions to enter or exit the cell and changing the local transmembrane potential. The resulting change in voltage is called a postsynaptic potential. In general, the result is excitatory in the case of depolarizing currents, and inhibitory in the case of hyperpolarizing currents. Whether a synapse is excitatory or inhibitory depends on what type(s) of ion channel conduct the postsynaptic current(s), which in turn is a function of the type of receptors and neurotransmitter employed at the synapse. The second way a receptor can affect membrane potential is by modulating the production of chemical messengers inside the postsynaptic neuron. These second messengers can then amplify the inhibitory or excitatory response to neurotransmitters. Termination After a neurotransmitter molecule binds to a receptor molecule, it must be removed to allow for the postsynaptic membrane to continue to relay subsequent EPSPs and/or IPSPs. This removal can happen through one or more processes: The neurotransmitter may diffuse away due to thermally-induced oscillations of both it and the receptor, making it available to be broken down metabolically outside the neuron or to be reabsorbed. Enzymes within the subsynaptic membrane may inactivate/metabolize the neurotransmitter. Reuptake pumps may actively pump the neurotransmitter back into the presynaptic axon terminal for reprocessing and re-release following a later action potential. Synaptic strength The strength of a synapse has been defined by Sir Bernard Katz as the product of (presynaptic) release probability pr, quantal size q (the postsynaptic response to the release of a single neurotransmitter vesicle, a 'quantum'), and n, the number of release sites. "Unitary connection" usually refers to an unknown number of individual synapses connecting a presynaptic neuron to a postsynaptic neuron. The amplitude of postsynaptic potentials (PSPs) can be as low as 0.4 mV to as high as 20 mV. The amplitude of a PSP can be modulated by neuromodulators or can change as a result of previous activity. Changes in the synaptic strength can be short-term, lasting seconds to minutes, or long-term (long-term potentiation, or LTP), lasting hours. Learning and memory are believed to result from long-term changes in synaptic strength, via a mechanism known as synaptic plasticity. Receptor desensitization Desensitization of the postsynaptic receptors is a decrease in response to the same neurotransmitter stimulus. It means that the strength of a synapse may in effect diminish as a train of action potentials arrive in rapid succession – a phenomenon that gives rise to the so-called frequency dependence of synapses. The nervous system exploits this property for computational purposes, and can tune its synapses through such means as phosphorylation of the proteins involved. Synaptic plasticity Synaptic transmission can be changed by previous activity. These changes are called synaptic plasticity and may result in either a decrease in the efficacy of the synapse, called depression, or an increase in efficacy, called potentiation. These changes can either be long-term or short-term. Forms of short-term plasticity include synaptic fatigue or depression and synaptic augmentation. Forms of long-term plasticity include long-term depression and long-term potentiation. Synaptic plasticity can be either homosynaptic (occurring at a single synapse) or heterosynaptic (occurring at multiple synapses). Homosynaptic plasticity Homosynaptic plasticity (or also homotropic modulation) is a change in the synaptic strength that results from the history of activity at a particular synapse. This can result from changes in presynaptic calcium as well as feedback onto presynaptic receptors, i.e. a form of autocrine signaling. Homosynaptic plasticity can affect the number and replenishment rate of vesicles or it can affect the relationship between calcium and vesicle release. Homosynaptic plasticity can also be postsynaptic in nature. It can result in either an increase or decrease in synaptic strength. One example is neurons of the sympathetic nervous system (SNS), which release noradrenaline, which, besides affecting postsynaptic receptors, also affects presynaptic α2-adrenergic receptors, inhibiting further release of noradrenaline. This effect is utilized with clonidine to perform inhibitory effects on the SNS. Heterosynaptic plasticity Heterosynaptic plasticity (or also heterotropic modulation) is a change in synaptic strength that results from the activity of other neurons. Again, the plasticity
also learned interference pairs right before being retested to try to disrupt the previously learned word pairs. The results showed that sleep was of some help in retaining the word pair associations, while against the interference pair, sleep helped significantly. After sleep, there is increased insight. This is because sleep helps people to reanalyze their memories. The same patterns of brain activity that occur during learning have been found to occur again during sleep, only faster. One way that sleep strengthens memories is by weeding out the less successful connections between neurons in the brain. This weeding out is essential to prevent overactivity. The brain compensates for strengthening some synapses (connections) between neurons, by weakening others. The weakening process occurs mostly during sleep. This weakening during sleep allows for strengthening of other connections while we are awake. Learning is the process of strengthening connections, therefore this process could be a major explanation for the benefits that sleep has on memory. Research has shown that taking an afternoon nap increases learning capacity. A study tested two groups of subjects on a nondeclarative memory task. One group engaged in REM sleep, and one group did not (meaning that they engaged in NREM sleep). The investigators found that the subjects who engaged only in NREM sleep did not show much improvement. The subjects who engaged in REM sleep performed significantly better, indicating that REM sleep facilitated the consolidation of nondeclarative memories. A more recent study demonstrated that a procedural task was learned and retained better if it was encountered immediately before going to sleep, while a declarative task was learned better in the afternoon. Electrophysiological evidence in rats A 2009 study based on electrophysiological recordings of large ensembles of isolated cells in the prefrontal cortex of rats revealed that cell assemblies that formed upon learning were more preferentially active during subsequent sleep episodes. More specifically, those replay events were more prominent during slow wave sleep and were concomitant with hippocampal reactivation events. This study has shown that neuronal patterns in large brain networks are tagged during learning so that they are replayed, and supposedly consolidated, during subsequent sleep. There have been other studies that have shown similar reactivation of learning pattern during motor skill and neuroprosthetic learning. Notably, new evidence is showing that reactivation and rescaling may be co-occurring during sleep. Sleep in relation to school Sleep has been directly linked to the grades of students. One in four U.S. high school students admit to falling asleep in class at least once a week. Consequently, results have shown that those who sleep less do poorly. In the United States, sleep deprivation is common with students because almost all schools begin early in the morning and many of these students either choose to stay awake late into the night or cannot do otherwise due to delayed sleep phase syndrome. As a result, students that should be getting between 8.5 and 9.25 hours of sleep are getting only 7 hours. Perhaps because of this sleep deprivation, their grades are lower and their concentration is impaired. As a result of studies showing the effects of sleep deprivation on grades, and the different sleep patterns for teenagers, a school in New Zealand, changed its start time to 10:30 a.m., in 2006, to allow students to keep to a schedule that allowed more sleep. In 2009, Monkseaton High School, in North Tyneside, had 800 pupils aged 13–19 starting lessons at 10 a.m. instead of the normal 9 a.m. and reported that general absence dropped by 8% and persistent absenteeism by 27%. Similarly, a high school in Copenhagen has committed to providing at least one class per year for students who will start at 10 a.m. or later. College students represent one of the most sleep-deprived segments of our population. Only 11% of American college students sleep well, and 40% of students feel well rested only two days per	This study gives evidence that REM sleep is a significant factor in consolidating motor skill procedural memories, therefore sleep deprivation can impair performance on a motor learning task. This memory decrement results specifically from the loss of stage 2, REM sleep. Declarative memory has also been shown to benefit from sleep, but not in the same way as procedural memory. Declarative memories benefit from the slow-waves nREM sleep. A study was conducted where the subjects learned word pairs, and the results showed that sleep not only prevents the decay of memory, but also actively fixates declarative memories. Two of the groups learned word pairs, then either slept or stayed awake, and were tested again. The other two groups did the same thing, except they also learned interference pairs right before being retested to try to disrupt the previously learned word pairs. The results showed that sleep was of some help in retaining the word pair associations, while against the interference pair, sleep helped significantly. After sleep, there is increased insight. This is because sleep helps people to reanalyze their memories. The same patterns of brain activity that occur during learning have been found to occur again during sleep, only faster. One way that sleep strengthens memories is by weeding out the less successful connections between neurons in the brain. This weeding out is essential to prevent overactivity. The brain compensates for strengthening some synapses (connections) between neurons, by weakening others. The weakening process occurs mostly during sleep. This weakening during sleep allows for strengthening of other connections while we are awake. Learning is the process of strengthening connections, therefore this process could be a major explanation for the benefits that sleep has on memory. Research has shown that taking an afternoon nap increases learning capacity. A study tested two groups of subjects on a nondeclarative memory task. One group engaged in REM sleep, and one group did not (meaning that they engaged in NREM sleep). The investigators found that the subjects who engaged only in NREM sleep did not show much improvement. The subjects who engaged in REM sleep performed significantly better, indicating that REM sleep facilitated the consolidation of nondeclarative memories. A more recent study demonstrated that a procedural task was learned and retained better if it was encountered immediately before going to sleep, while a declarative task was learned better in the afternoon. Electrophysiological evidence in rats A 2009 study based on electrophysiological recordings of large ensembles of isolated cells in the prefrontal cortex of rats revealed that cell assemblies that formed upon learning were more preferentially active during subsequent sleep episodes. More specifically, those replay events were more prominent during slow wave sleep and were concomitant with hippocampal reactivation events. This study has shown that neuronal patterns in large brain networks are tagged during learning so that they are replayed, and supposedly consolidated, during subsequent sleep. There have been other studies that have shown similar reactivation of learning pattern during motor skill and neuroprosthetic learning. Notably, new evidence is showing that reactivation and rescaling may be co-occurring during sleep. Sleep in relation to school Sleep has been directly linked to the grades of students. One in four U.S. high school students admit to falling asleep in class at least once a week. Consequently, results have shown that those who sleep less do poorly. In the United States, sleep deprivation is common with students because almost all schools begin early in the morning and many of these students either choose to stay awake late into the night or cannot do otherwise
in mass circulation Bullion coins Hard money (policy) Commodity money Specie Circular,	other metal money in mass circulation Bullion coins Hard money (policy) Commodity money Specie Circular, 1836
wrote of "systematic botany" rather than using the term "systematics". In 1970 Michener et al. defined "systematic biology" and "taxonomy" (terms that are often confused and used interchangeably) in relationship to one another as follows: Systematic biology (hereafter called simply systematics) is the field that (a) provides scientific names for organisms, (b) describes them, (c) preserves collections of them, (d) provides classifications for the organisms, keys for their identification, and data on their distributions, (e) investigates their evolutionary histories, and (f) considers their environmental adaptations. This is a field with a long history that in recent years has experienced a notable renaissance, principally with respect to theoretical content. Part of the theoretical material has to do with evolutionary areas (topics e and f above), the rest relates especially to the problem of classification. Taxonomy is that part of Systematics concerned with topics (a) to (d) above. The term "taxonomy" was coined by Augustin Pyramus de Candolle while the term "systematic" was coined by Carl Linnaeus the father of taxonomy. Taxonomy, systematic biology, systematics, biosystematics, scientific classification, biological classification, phylogenetics: At various times in history, all these words have had overlapping, related meanings. However, in modern usage, they can all be considered synonyms of each other. For example, Webster's 9th New Collegiate Dictionary of 1987 treats "classification", "taxonomy", and "systematics" as synonyms. According to this work, the terms originated in 1790, c. 1828, and in 1888 respectively. Some claim systematics alone deals specifically with relationships through time, and that it can be synonymous with phylogenetics, broadly dealing with the inferred hierarchy of organisms. This means it would be a subset of taxonomy as it is sometimes regarded, but the inverse is claimed by others. Europeans tend to use the terms "systematics" and "biosystematics" for the study of biodiversity as a whole, whereas North Americans tend to use "taxonomy" more frequently. However, taxonomy, and in particular alpha taxonomy, is more specifically the identification, description, and naming (i.e. nomenclature) of organisms, while "classification" focuses on placing organisms within hierarchical groups that show their relationships to other organisms. All of these biological disciplines can deal with both extinct and extant organisms. Systematics uses taxonomy as a primary tool in understanding, as nothing about an organism's relationships with other living things can be understood without it first being properly studied and described in sufficient detail to identify and classify it correctly. Scientific classifications are aids in recording and reporting information to other scientists and to laymen. The systematist, a scientist who specializes in systematics, must, therefore, be able to use existing classification systems, or at least know them well enough to skilfully justify not using them. Phenetics was an attempt to determine the relationships of organisms through a measure of overall similarity, making no distinction between plesiomorphies (shared ancestral traits) and apomorphies (derived	in systematics, must, therefore, be able to use existing classification systems, or at least know them well enough to skilfully justify not using them. Phenetics was an attempt to determine the relationships of organisms through a measure of overall similarity, making no distinction between plesiomorphies (shared ancestral traits) and apomorphies (derived traits). From the late-20th century onwards, it was superseded by cladistics, which rejects plesiomorphies in attempting to resolve the phylogeny of Earth's various organisms through time. systematists generally make extensive use of molecular biology and of computer programs to study organisms. Taxonomic characters Taxonomic characters are the taxonomic attributes that can be used to provide the evidence from which relationships (the phylogeny) between taxa are inferred. Kinds of taxonomic characters include: Morphological characters General external morphology Special structures (e.g. genitalia) Internal morphology (anatomy) Embryology Karyology and other cytological factors Physiological characters Metabolic factors Body secretions Genic sterility factors Molecular characters Immunological distance Electrophoretic differences Amino acid sequences of proteins DNA hybridization DNA and RNA sequences Restriction endonuclease analyses Other molecular differences Behavioral characters Courtship and other ethological isolating mechanisms Other behavior patterns Ecological characters Habit and habitats Food Seasonal variations Parasites and hosts Geographic characters General biogeographic distribution patterns Sympatric-allopatric relationship of populations See also Cladistics – a methodology in systematics Evolutionary systematics – a school of systematics Global biodiversity Phenetics – a methodology in systematics that does not infer phylogeny Phylogeny – the historical relationships between lineages of organism 16S ribosomal RNA – an intensively studied nucleic acid that has been useful in phylogenetics Phylogenetic comparative methods – use of evolutionary trees in other studies, such as biodiversity, comparative biology. adaptation, or evolutionary mechanisms References Notes Further reading Schuh, Randall T. and Andrew V. Z. Brower. 2009. Biological Systematics: Principles and Applications, 2nd edn. Simpson, Michael G. 2005. Plant Systematics. Wiley, Edward O. and Bruce S. Lieberman. 2011. "Phylogenetics: Theory and Practice of Phylogenetic Systematics, 2nd edn." External links Society of
wave, a mathematical function Sine and cosine transforms Sine quadrant Sine-Gordon equation Places Sinë, village in Albania Sine, Washington, a community in the United States Kingdom of Sine, a former kingdom in modern Senegal See also SINE (disambiguation) Port of Sines, a deep-water port in	refer to: Maurice Sinet or Siné (1928–2016), a French cartoonist Sine FM, a community radio station based in Doncaster, South Yorkshire Short interspersed nuclear elements (SINEs), a short DNA sequences in eukaryote genomes Sine bar Sine (album), a 2008 album by C418 Mathematics Abbe sine
conscious. Their eyes may be closed and all of their body is taking a break, where the body is starting to slow down. Beta waves take over alpha waves when a person is at attention, as they might be completing a task or concentrating on something. Beta waves although consist of the highest of frequencies and the lowest of amplitude, at this point a person is fully alert. Alpha and beta waves are the only waves seen when a person is in an awake state. Gamma waves are seen when a person is highly focused on a task or using all their concentration. Theta waves occur during the period of a person being awake, and continue they transition into Stage 1 of sleep on in stage 2. Delta waves are seen in stage 3 and 4 of sleep, when a person is in their deepest of sleep. Non-REM and REM sleep Sleep is divided into two broad types: non-rapid eye movement (non-REM or NREM) sleep and rapid eye movement (REM) sleep. Non-REM and REM sleep are so different that physiologists identify them as distinct behavioral states. Non-REM sleep occurs first and after a transitional period is called slow-wave sleep or deep sleep. During this phase, body temperature and heart rate fall, and the brain uses less energy. REM sleep, also known as paradoxical sleep, represents a smaller portion of total sleep time. It is the main occasion for dreams (or nightmares), and is associated with desynchronized and fast brain waves, eye movements, loss of muscle tone, and suspension of homeostasis. The sleep cycle of alternate NREM and REM sleep takes an average of 90 minutes, occurring 4–6 times in a good night's sleep. The American Academy of Sleep Medicine (AASM) divides NREM into three stages: N1, N2, and N3, the last of which is also called delta sleep or slow-wave sleep. The whole period normally proceeds in the order: N1 → N2 → N3 → N2 → REM. REM sleep occurs as a person returns to stage 2 or 1 from a deep sleep. There is a greater amount of deep sleep (stage N3) earlier in the night, while the proportion of REM sleep increases in the two cycles just before natural awakening. Awakening Awakening can mean the end of sleep, or simply a moment to survey the environment and readjust body position before falling back asleep. Sleepers typically awaken soon after the end of a REM phase or sometimes in the middle of REM. Internal circadian indicators, along with a successful reduction of homeostatic sleep need, typically bring about awakening and the end of the sleep cycle. Awakening involves heightened electrical activation in the brain, beginning with the thalamus and spreading throughout the cortex. During a night's sleep, a small amount of time is usually spent in a waking state. As measured by electroencephalography, young females are awake for 0–1% of the larger sleeping period; young males are awake for 0–2%. In adults, wakefulness increases, especially in later cycles. One study found 3% awake time in the first ninety-minute sleep cycle, 8% in the second, 10% in the third, 12% in the fourth, and 13–14% in the fifth. Most of this awake time occurred shortly after REM sleep. Today, many humans wake up with an alarm clock; however, people can also reliably wake themselves up at a specific time with no need for an alarm. Many sleep quite differently on workdays versus days off, a pattern which can lead to chronic circadian desynchronization. Many people regularly look at television and other screens before going to bed, a factor which may exacerbate disruption of the circadian cycle. Scientific studies on sleep have shown that sleep stage at awakening is an important factor in amplifying sleep inertia. Timing Sleep timing is controlled by the circadian clock (Process C), sleep-wake homeostasis (Process S), and to some extent by the individual will. Circadian clock Sleep timing depends greatly on hormonal signals from the circadian clock, or Process C, a complex neurochemical system which uses signals from an organism's environment to recreate an internal day–night rhythm. Process C counteracts the homeostatic drive for sleep during the day (in diurnal animals) and augments it at night. The suprachiasmatic nucleus (SCN), a brain area directly above the optic chiasm, is presently considered the most important nexus for this process; however, secondary clock systems have been found throughout the body. An organism whose circadian clock exhibits a regular rhythm corresponding to outside signals is said to be entrained; an entrained rhythm persists even if the outside signals suddenly disappear. If an entrained human is isolated in a bunker with constant light or darkness, he or she will continue to experience rhythmic increases and decreases of body temperature and melatonin, on a period that slightly exceeds 24 hours. Scientists refer to such conditions as free-running of the circadian rhythm. Under natural conditions, light signals regularly adjust this period downward, so that it corresponds better with the exact 24 hours of an Earth day. The circadian clock exerts constant influence on the body, affecting sinusoidal oscillation of body temperature between roughly 36.2 °C and 37.2 °C. The suprachiasmatic nucleus itself shows conspicuous oscillation activity, which intensifies during subjective day (i.e., the part of the rhythm corresponding with daytime, whether accurately or not) and drops to almost nothing during subjective night. The circadian pacemaker in the suprachiasmatic nucleus has a direct neural connection to the pineal gland, which releases the hormone melatonin at night. Cortisol levels typically rise throughout the night, peak in the awakening hours, and diminish during the day. Circadian prolactin secretion begins in the late afternoon, especially in women, and is subsequently augmented by sleep-induced secretion, to peak in the middle of the night. Circadian rhythm exerts some influence on the nighttime secretion of growth hormone. The circadian rhythm influences the ideal timing of a restorative sleep episode. Sleepiness increases during the night. REM sleep occurs more during body temperature minimum within the circadian cycle, whereas slow-wave sleep can occur more independently of circadian time. The internal circadian clock is profoundly influenced by changes in light, since these are its main clues about what time it is. Exposure to even small amounts of light during the night can suppress melatonin secretion, and increase body temperature and wakefulness. Short pulses of light, at the right moment in the circadian cycle, can significantly 'reset' the internal clock. Blue light, in particular, exerts the strongest effect, leading to concerns that electronic media use before bed may interfere with sleep. Modern humans often find themselves desynchronized from their internal circadian clock, due to the requirements of work (especially night shifts), long-distance travel, and the influence of universal indoor lighting. Even if they have sleep debt, or feel sleepy, people can have difficulty staying asleep at the peak of their circadian cycle. Conversely, they can have difficulty waking up in the trough of the cycle. A healthy young adult entrained to the sun will (during most of the year) fall asleep a few hours after sunset, experience body temperature minimum at 6 a.m., and wake up a few hours after sunrise. Process S Generally speaking, the longer an organism is awake, the more it feels a need to sleep ("sleep debt"). This driver of sleep is referred to as Process S. The balance between sleeping and waking is regulated by a process called homeostasis. Induced or perceived lack of sleep is called sleep deprivation. Process S is driven by the depletion of glycogen and accumulation of adenosine in the forebrain that disinhibits the ventrolateral preoptic nucleus, allowing for inhibition of the ascending reticular activating system. Sleep deprivation tends to cause slower brain waves in the frontal cortex, shortened attention span, higher anxiety, impaired memory, and a grouchy mood. Conversely, a well-rested organism tends to have improved memory and mood. Neurophysiological and functional imaging studies have demonstrated that frontal regions of the brain are particularly responsive to homeostatic sleep pressure. There is disagreement on how much sleep debt is possible to accumulate, and whether sleep debt is accumulated against an individual's average sleep or some other benchmark. It is also unclear whether the prevalence of sleep debt among adults has changed appreciably in the industrialized world in recent decades. Sleep debt does show some evidence of being cumulative. Subjectively, however, humans seem to reach maximum sleepiness after 30 hours of waking up. It is likely that in Western societies, children are sleeping less than they previously have. One neurochemical indicator of sleep debt is adenosine, a neurotransmitter that inhibits many of the bodily processes associated with wakefulness. Adenosine levels increase in the cortex and basal forebrain during prolonged wakefulness, and decrease during the sleep-recovery period, potentially acting as a homeostatic regulator of sleep. Coffee and caffeine temporarily block the effect of adenosine, prolong sleep latency, and reduce total sleep time and quality. Social timing Humans are also influenced by aspects of social time, such as the hours when other people are awake, the hours when work is required, the time on the clock, etc. Time zones, standard times used to unify the timing for people in the same area, correspond only approximately to the natural rising and setting of the sun. The approximate nature of the time zone can be shown with China, a country which used to span five time zones and now officially uses only one (UTC+8). Distribution In polyphasic sleep, an organism sleeps several times in a 24-hour cycle, whereas in monophasic sleep this occurs all at once. Under experimental conditions, humans tend to alternate more frequently between sleep and wakefulness (i.e., exhibit more polyphasic sleep) if they have nothing better to do. Given a 14-hour period of darkness in experimental conditions, humans tended towards bimodal sleep, with two sleep periods concentrated at the beginning and at the end of the dark time. Bimodal sleep in humans was more common before the industrial revolution. Different characteristic sleep patterns, such as the familiarly so-called "early bird" and "night owl", are called chronotypes. Genetics and sex have some influence on chronotype, but so do habits. Chronotype is also liable to change over the course of a person's lifetime. Seven-year-olds are better disposed to wake up early in the morning than are fifteen-year-olds. Chronotypes far outside the normal range are called circadian rhythm sleep disorders. Naps This is a short period of sleep that one might take during the daytime, in order to get the necessary amount of rest. As we start taking naps at a young age, most people assume you grow out of this phase of sleeping pattern. Yet around one-third of American adults partake in this, daily. The right amount of nap time is around 10–20 minutes, as researchers have proven that it takes at least 30 minutes to enter the slow-wave sleep where one is at their deepest of sleep. If one naps for too long, getting into the slow wave cycles, it can be hard to awake from this nap and leaving one feeling unrested. This is called sleep inertia, which means that one would be in a state of drowsiness for a period of time. Each nap can be taken for various reason, some have categorized them into types of naps. The categories include; Recovery, Prophylactic, Appetitive, Fulfillment, and Essential. A recovery nap is a way to make up for sleep loss. Prophylactic means to prevent, so in napping terms this means to get sleep needed before an anticipated long period of being awake. An Appetitive nap are simply taken because a person simply enjoys the activity of napping. Fulfillment naps are exactly how it sounds, naps taken to fulfill your body. These are often seen as scheduled naps but can also occur at any time of the day, when a person becomes in need of rest. The naps taken when one is sick and needs extra rest in order for their body's immune system to heal are Essential naps. The siesta habit has recently been associated with a 37% lower coronary mortality, possibly due to reduced cardiovascular stress mediated by daytime sleep. Short naps at mid-day and mild evening exercise were found to be effective for improved sleep, cognitive tasks, and mental health in elderly people. Genetics Monozygotic (identical) but not dizygotic (fraternal) twins tend to have similar sleep habits. Neurotransmitters, molecules whose production can be traced to specific genes, are one genetic influence on sleep that can be analyzed. The circadian clock has its own set of genes. Genes which may influence sleep include ABCC9, DEC2, Dopamine receptor D2 and variants near PAX 8 and VRK2. While the latter have been found in a GWAS study that primarily detects correlations (but not necessarily causation), other genes have been shown to have a more direct effect. For instance, mice lacking dihydropyrimidine dehydrogenase (Dpyd) had 78.4 min less sleep during the lights-off period than wild-type mice. Dpyd encodes the rate-limiting enzyme in the metabolic pathway that catabolizes uracil and thymidine to β-alanine, an inhibitory neurotransmitter. This also supports the role of β-alanine as a neurotransmitter that promotes sleep in mice. Quality The quality of sleep may be evaluated from an objective and a subjective point of view. Objective sleep quality refers to how difficult it is for a person to fall asleep and remain in a sleeping state, and how many times they wake up during a single night. Poor sleep quality disrupts the cycle of transition between the different stages of sleep. Subjective sleep quality in turn refers to a sense of being rested and regenerated after awaking from sleep. A study by A. Harvey et al. (2002) found that insomniacs were more demanding in their evaluations of sleep quality than individuals who had no sleep problems. Homeostatic sleep propensity (the need for sleep as a function of the amount of time elapsed since the last adequate sleep episode) must be balanced against the circadian element for satisfactory sleep. Along with corresponding messages from the circadian clock, this tells the body it needs to sleep. The timing is correct when the following two circadian markers occur after the middle of the sleep episode and before awakening: maximum concentration of the hormone melatonin, and minimum core body temperature. Ideal duration Human sleep-needs vary by age and amongst individuals; sleep is considered to be adequate when there is no daytime sleepiness or dysfunction. Moreover, self-reported sleep duration is only moderately correlated with actual sleep time as measured by actigraphy, and those affected with sleep state misperception may typically report having slept only four hours despite having slept a full eight hours. Researchers have found that sleeping 6–7 hours each night correlates with longevity and cardiac health in humans, though many underlying factors may be involved in the causality behind this relationship. Sleep difficulties are furthermore associated with psychiatric disorders such as depression, alcoholism, and bipolar disorder. Up to 90 percent of adults with depression are found to have sleep difficulties. Dysregulation detected by EEG includes disturbances in sleep continuity, decreased delta sleep and altered REM patterns with regard to latency, distribution across the night and density of eye movements. Sleep duration can also vary according to season. Up to 90% of people report longer sleep duration in winter, which may lead to more pronounced seasonal affective disorder. Children By the time infants reach the age of two, their brain size has reached 90 percent of an adult-sized brain; a majority of this brain growth has occurred during the period of life with the highest rate of sleep. The hours that children spend asleep influence their ability to perform on cognitive tasks. Children who sleep through the night and have few night waking episodes have higher cognitive attainments and easier temperaments than other children. Sleep also influences language development. To test this, researchers taught infants a faux language and observed their recollection of the rules for that language. Infants who slept within four hours of learning the language could remember the language rules better, while infants who stayed awake longer did not recall those rules as well. There is also a relationship between infants' vocabulary and sleeping: infants who sleep longer at night at 12 months have better vocabularies at 26 months. Children can greatly benefit from a structured bedtime routine. This can look differently among families, but will generally consist of a rituals such as reading a bedtime story, a bath, brushing teeth, and can also include a show of affection from the parent to the child such a hug or kiss before bed. A bedtime routine will also include a consistent time that the child is expected to be in bed ready for sleep. Having a reliable bedtime routine can help improve a child's quality of sleep as well as prepare them to make and keep healthy sleep hygiene habits in the future. Hours of sleep Children need many hours of sleep per day in order to develop and function properly: up to 18 hours for newborn babies, with a declining rate as a child ages. Early in 2015, after a two-year study, the National Sleep Foundation in the US announced newly revised recommendations as shown in the table below. Functions Restoration The human organism physically restores itself during sleep, occurring mostly during slow-wave sleep during which body temperature, heart rate, and brain oxygen consumption decrease. In both the brain and body, the reduced rate of metabolism enables countervailing restorative processes. The brain requires sleep for restoration, whereas these processes can take place during quiescent waking in the rest of the body. The essential function of sleep may be its restorative effect on the brain: "Sleep is of the brain, by the brain and for the brain." This theory is strengthened by the fact that sleep is observed to be a necessary behavior across most of the animal kingdom, including some of the least evolved animals which have no need for other functions of sleep, such as memory consolidation or dreaming. While awake, brain metabolism generates end products, such as reactive oxygen species, which may be damaging to brain cells and inhibit their proper function. During sleep, metabolic rates decrease and reactive	to concerns that electronic media use before bed may interfere with sleep. Modern humans often find themselves desynchronized from their internal circadian clock, due to the requirements of work (especially night shifts), long-distance travel, and the influence of universal indoor lighting. Even if they have sleep debt, or feel sleepy, people can have difficulty staying asleep at the peak of their circadian cycle. Conversely, they can have difficulty waking up in the trough of the cycle. A healthy young adult entrained to the sun will (during most of the year) fall asleep a few hours after sunset, experience body temperature minimum at 6 a.m., and wake up a few hours after sunrise. Process S Generally speaking, the longer an organism is awake, the more it feels a need to sleep ("sleep debt"). This driver of sleep is referred to as Process S. The balance between sleeping and waking is regulated by a process called homeostasis. Induced or perceived lack of sleep is called sleep deprivation. Process S is driven by the depletion of glycogen and accumulation of adenosine in the forebrain that disinhibits the ventrolateral preoptic nucleus, allowing for inhibition of the ascending reticular activating system. Sleep deprivation tends to cause slower brain waves in the frontal cortex, shortened attention span, higher anxiety, impaired memory, and a grouchy mood. Conversely, a well-rested organism tends to have improved memory and mood. Neurophysiological and functional imaging studies have demonstrated that frontal regions of the brain are particularly responsive to homeostatic sleep pressure. There is disagreement on how much sleep debt is possible to accumulate, and whether sleep debt is accumulated against an individual's average sleep or some other benchmark. It is also unclear whether the prevalence of sleep debt among adults has changed appreciably in the industrialized world in recent decades. Sleep debt does show some evidence of being cumulative. Subjectively, however, humans seem to reach maximum sleepiness after 30 hours of waking up. It is likely that in Western societies, children are sleeping less than they previously have. One neurochemical indicator of sleep debt is adenosine, a neurotransmitter that inhibits many of the bodily processes associated with wakefulness. Adenosine levels increase in the cortex and basal forebrain during prolonged wakefulness, and decrease during the sleep-recovery period, potentially acting as a homeostatic regulator of sleep. Coffee and caffeine temporarily block the effect of adenosine, prolong sleep latency, and reduce total sleep time and quality. Social timing Humans are also influenced by aspects of social time, such as the hours when other people are awake, the hours when work is required, the time on the clock, etc. Time zones, standard times used to unify the timing for people in the same area, correspond only approximately to the natural rising and setting of the sun. The approximate nature of the time zone can be shown with China, a country which used to span five time zones and now officially uses only one (UTC+8). Distribution In polyphasic sleep, an organism sleeps several times in a 24-hour cycle, whereas in monophasic sleep this occurs all at once. Under experimental conditions, humans tend to alternate more frequently between sleep and wakefulness (i.e., exhibit more polyphasic sleep) if they have nothing better to do. Given a 14-hour period of darkness in experimental conditions, humans tended towards bimodal sleep, with two sleep periods concentrated at the beginning and at the end of the dark time. Bimodal sleep in humans was more common before the industrial revolution. Different characteristic sleep patterns, such as the familiarly so-called "early bird" and "night owl", are called chronotypes. Genetics and sex have some influence on chronotype, but so do habits. Chronotype is also liable to change over the course of a person's lifetime. Seven-year-olds are better disposed to wake up early in the morning than are fifteen-year-olds. Chronotypes far outside the normal range are called circadian rhythm sleep disorders. Naps This is a short period of sleep that one might take during the daytime, in order to get the necessary amount of rest. As we start taking naps at a young age, most people assume you grow out of this phase of sleeping pattern. Yet around one-third of American adults partake in this, daily. The right amount of nap time is around 10–20 minutes, as researchers have proven that it takes at least 30 minutes to enter the slow-wave sleep where one is at their deepest of sleep. If one naps for too long, getting into the slow wave cycles, it can be hard to awake from this nap and leaving one feeling unrested. This is called sleep inertia, which means that one would be in a state of drowsiness for a period of time. Each nap can be taken for various reason, some have categorized them into types of naps. The categories include; Recovery, Prophylactic, Appetitive, Fulfillment, and Essential. A recovery nap is a way to make up for sleep loss. Prophylactic means to prevent, so in napping terms this means to get sleep needed before an anticipated long period of being awake. An Appetitive nap are simply taken because a person simply enjoys the activity of napping. Fulfillment naps are exactly how it sounds, naps taken to fulfill your body. These are often seen as scheduled naps but can also occur at any time of the day, when a person becomes in need of rest. The naps taken when one is sick and needs extra rest in order for their body's immune system to heal are Essential naps. The siesta habit has recently been associated with a 37% lower coronary mortality, possibly due to reduced cardiovascular stress mediated by daytime sleep. Short naps at mid-day and mild evening exercise were found to be effective for improved sleep, cognitive tasks, and mental health in elderly people. Genetics Monozygotic (identical) but not dizygotic (fraternal) twins tend to have similar sleep habits. Neurotransmitters, molecules whose production can be traced to specific genes, are one genetic influence on sleep that can be analyzed. The circadian clock has its own set of genes. Genes which may influence sleep include ABCC9, DEC2, Dopamine receptor D2 and variants near PAX 8 and VRK2. While the latter have been found in a GWAS study that primarily detects correlations (but not necessarily causation), other genes have been shown to have a more direct effect. For instance, mice lacking dihydropyrimidine dehydrogenase (Dpyd) had 78.4 min less sleep during the lights-off period than wild-type mice. Dpyd encodes the rate-limiting enzyme in the metabolic pathway that catabolizes uracil and thymidine to β-alanine, an inhibitory neurotransmitter. This also supports the role of β-alanine as a neurotransmitter that promotes sleep in mice. Quality The quality of sleep may be evaluated from an objective and a subjective point of view. Objective sleep quality refers to how difficult it is for a person to fall asleep and remain in a sleeping state, and how many times they wake up during a single night. Poor sleep quality disrupts the cycle of transition between the different stages of sleep. Subjective sleep quality in turn refers to a sense of being rested and regenerated after awaking from sleep. A study by A. Harvey et al. (2002) found that insomniacs were more demanding in their evaluations of sleep quality than individuals who had no sleep problems. Homeostatic sleep propensity (the need for sleep as a function of the amount of time elapsed since the last adequate sleep episode) must be balanced against the circadian element for satisfactory sleep. Along with corresponding messages from the circadian clock, this tells the body it needs to sleep. The timing is correct when the following two circadian markers occur after the middle of the sleep episode and before awakening: maximum concentration of the hormone melatonin, and minimum core body temperature. Ideal duration Human sleep-needs vary by age and amongst individuals; sleep is considered to be adequate when there is no daytime sleepiness or dysfunction. Moreover, self-reported sleep duration is only moderately correlated with actual sleep time as measured by actigraphy, and those affected with sleep state misperception may typically report having slept only four hours despite having slept a full eight hours. Researchers have found that sleeping 6–7 hours each night correlates with longevity and cardiac health in humans, though many underlying factors may be involved in the causality behind this relationship. Sleep difficulties are furthermore associated with psychiatric disorders such as depression, alcoholism, and bipolar disorder. Up to 90 percent of adults with depression are found to have sleep difficulties. Dysregulation detected by EEG includes disturbances in sleep continuity, decreased delta sleep and altered REM patterns with regard to latency, distribution across the night and density of eye movements. Sleep duration can also vary according to season. Up to 90% of people report longer sleep duration in winter, which may lead to more pronounced seasonal affective disorder. Children By the time infants reach the age of two, their brain size has reached 90 percent of an adult-sized brain; a majority of this brain growth has occurred during the period of life with the highest rate of sleep. The hours that children spend asleep influence their ability to perform on cognitive tasks. Children who sleep through the night and have few night waking episodes have higher cognitive attainments and easier temperaments than other children. Sleep also influences language development. To test this, researchers taught infants a faux language and observed their recollection of the rules for that language. Infants who slept within four hours of learning the language could remember the language rules better, while infants who stayed awake longer did not recall those rules as well. There is also a relationship between infants' vocabulary and sleeping: infants who sleep longer at night at 12 months have better vocabularies at 26 months. Children can greatly benefit from a structured bedtime routine. This can look differently among families, but will generally consist of a rituals such as reading a bedtime story, a bath, brushing teeth, and can also include a show of affection from the parent to the child such a hug or kiss before bed. A bedtime routine will also include a consistent time that the child is expected to be in bed ready for sleep. Having a reliable bedtime routine can help improve a child's quality of sleep as well as prepare them to make and keep healthy sleep hygiene habits in the future. Hours of sleep Children need many hours of sleep per day in order to develop and function properly: up to 18 hours for newborn babies, with a declining rate as a child ages. Early in 2015, after a two-year study, the National Sleep Foundation in the US announced newly revised recommendations as shown in the table below. Functions Restoration The human organism physically restores itself during sleep, occurring mostly during slow-wave sleep during which body temperature, heart rate, and brain oxygen consumption decrease. In both the brain and body, the reduced rate of metabolism enables countervailing restorative processes. The brain requires sleep for restoration, whereas these processes can take place during quiescent waking in the rest of the body. The essential function of sleep may be its restorative effect on the brain: "Sleep is of the brain, by the brain and for the brain." This theory is strengthened by the fact that sleep is observed to be a necessary behavior across most of the animal kingdom, including some of the least evolved animals which have no need for other functions of sleep, such as memory consolidation or dreaming. While awake, brain metabolism generates end products, such as reactive oxygen species, which may be damaging to brain cells and inhibit their proper function. During sleep, metabolic rates decrease and reactive oxygen species generation is reduced, enabling restorative processes. The sleeping brain has been shown to remove metabolic end products at a faster rate than during an awake state. The mechanism for this removal appears to be the glymphatic system. Sleep may facilitate the synthesis of molecules that help repair and protect the brain from metabolic end products generated during waking. Anabolic hormones, such as growth hormones, are secreted preferentially during sleep. The brain concentration of glycogen increases during sleep, and is depleted through metabolism during wakefulness. The effect of sleep duration on somatic growth is not completely known. One study recorded growth, height, and weight, as correlated to parent-reported time in bed in 305 children over a period of nine years (age 1–10). It was found that "the variation of sleep duration among children does not seem to have an effect on growth." Slow-wave sleep affects growth hormone levels in adult men. During eight hours of sleep, men with a high percentage of slow-wave sleep (SWS) (average 24%) also had high growth hormone secretion, while subjects with a low percentage of SWS (average 9%) had low growth hormone secretion. Memory processing It has been widely accepted that sleep must support the formation of long-term memory, and generally increasing previous learning and experiences recalls. However, its benefit seems to depend on the phase of sleep and the type of memory. For example, declarative and procedural memory-recall tasks applied over early and late nocturnal sleep, as well as wakefulness controlled conditions, have been shown that declarative memory improves more during early sleep (dominated by SWS) while procedural memory during late sleep (dominated by REM sleep) does so. With regard to declarative memory, the functional role of SWS has been associated with hippocampal replays of previously encoded neural patterns that seem to facilitate long-term memory consolidation. This assumption is based on the active system consolidation hypothesis, which states that repeated reactivations of newly encoded information in the hippocampus during slow oscillations in NREM sleep mediate the stabilization and gradual integration of declarative memory with pre-existing knowledge networks on the cortical level. It assumes the hippocampus might hold information only temporarily and in a fast-learning rate, whereas the neocortex is related to long-term storage and a slow-learning rate. This dialogue between the hippocampus and neocortex occurs in parallel with hippocampal sharp-wave ripples and thalamo-cortical spindles, synchrony that drives the formation of the spindle-ripple event which seems to be a prerequisite for the formation of long-term memories. Reactivation of memory also occurs during wakefulness and its function is associated with serving to update the reactivated memory with newly encoded information, whereas reactivations during SWS are presented as crucial for memory stabilization. Based on targeted memory reactivation (TMR) experiments that use associated memory cues to triggering memory traces during sleep, several studies have been reassuring the importance of nocturnal reactivations for the formation of persistent memories in neocortical networks, as well as highlighting the possibility of increasing people's memory performance at declarative recalls. Furthermore, nocturnal reactivation seems to share the same neural oscillatory patterns as reactivation during wakefulness, processes which might be coordinated by theta activity. During wakefulness, theta oscillations have been often related to successful performance in memory tasks, and cued memory reactivations during sleep have been showing that theta activity is significantly stronger in subsequent recognition of cued stimuli as compared to uncued ones, possibly indicating a strengthening of memory traces and lexical integration by cuing during sleep. However, the beneficial effect of TMR for memory consolidation seems to occur only if the cued memories can be related to prior knowledge. Dreaming During sleep, especially REM sleep, humans tend to experience dreams. These are elusive and mostly unpredictable first-person experiences which seem logical and realistic to the dreamer while they are in progress, despite their frequently bizarre, irrational, and/or surreal qualities that become apparent when assessed after waking. Dreams often seamlessly incorporate concepts, situations, people, and objects within a person's mind that would not normally go together. They can include apparent sensations of all types, especially vision and movement. Dreams tend to rapidly fade from memory after waking. Some people choose to keep a dream journal, which they believe helps them build dream recall and facilitate the ability to experience lucid dreams. People have proposed many hypotheses about the functions of dreaming. Sigmund Freud postulated that dreams are the symbolic expression of frustrated desires that have been relegated to the unconscious mind, and he used dream interpretation in the form of psychoanalysis in attempting to uncover these desires. Counterintuitively, penile erections during sleep are not more frequent during sexual dreams than during other dreams. The parasympathetic nervous system experiences increased activity during REM sleep which may cause erection of the penis or clitoris. In males, 80% to 95% of REM sleep is normally accompanied by partial to full penile erection, while only about 12% of men's dreams contain sexual content. John Allan Hobson and Robert McCarley propose that dreams are caused by the random firing of neurons in the cerebral cortex during the REM period. Neatly, this theory helps explain the irrationality of the mind during REM periods, as, according to this theory, the forebrain then creates a story in an attempt to reconcile and make sense of the nonsensical sensory information presented to it. This would explain the odd nature of many dreams. Disorders Insomnia Insomnia is a general term for difficulty falling asleep and/or staying asleep. Insomnia is the most common sleep problem, with many adults reporting occasional insomnia, and 10–15% reporting a chronic condition. Insomnia can have many different causes, including psychological stress, a poor sleep environment, an inconsistent sleep schedule, or excessive mental or physical stimulation in the hours before bedtime. Insomnia is often treated through behavioral changes like keeping a regular sleep schedule, avoiding stimulating or stressful activities before bedtime, and cutting down on stimulants such as caffeine. The sleep environment may be improved by installing heavy drapes to shut out all sunlight, and keeping computers, televisions, and work materials out of the sleeping area. A 2010 review of published scientific research suggested that exercise generally improves sleep for most people, and helps sleep disorders such as insomnia. The optimum time to exercise may be 4 to 8 hours before bedtime, though exercise at any time of day is beneficial, with the exception of heavy exercise taken shortly before bedtime, which may disturb sleep. However, there is insufficient evidence to draw detailed conclusions about the relationship between exercise and sleep. Sleeping medications such as Ambien and Lunesta are an increasingly popular treatment for insomnia. Although these nonbenzodiazepine medications are generally believed to be better and safer than earlier generations of sedatives, they have still generated some controversy and discussion regarding side effects. White noise appears to be a promising treatment for insomnia. Obstructive sleep apnea Obstructive sleep apnea is a condition in which major pauses in breathing occur during sleep, disrupting the normal progression of sleep and often causing other more severe health problems. Apneas occur when the muscles around the patient's airway relax during sleep, causing the airway to collapse and block the intake of oxygen. Obstructive sleep apnea is more common than central sleep apnea. As oxygen levels in the blood drop, the patient then comes out of deep sleep in order to resume breathing. When several of these episodes occur per hour, sleep apnea rises to a level of seriousness that may require treatment. Diagnosing sleep apnea usually requires a professional sleep study performed in a sleep clinic, because the episodes of wakefulness caused by the disorder are extremely brief and patients usually do not remember experiencing them. Instead, many patients simply feel tired after getting several hours of sleep and have no idea why. Major risk factors for sleep apnea include chronic fatigue, old age, obesity, and snoring. Aging and sleep People over age 60 with prolonged sleep (8–10 hours or more; average sleep duration of 7–8 hours in the elderly) have a 33% increased risk of all-cause mortality and 43% increased risk of cardiovascular diseases, while those with short sleep (less than 7 hours) have a 6% increased risk of all-cause mortality. Sleep disorders, including sleep apnea, insomnia, or periodic limb movements, occur more commonly in the elderly, each possibly impacting sleep quality and duration. A 2017 review indicated that older adults do not need less sleep, but rather have an impaired ability to obtain their sleep needs, and may be able to deal with sleepiness better than younger adults. Various practices are recommended to mitigate sleep disturbances in the elderly, such as having a light bedtime snack, avoidance of caffeine, daytime naps, excessive evening stimulation, and tobacco products, and using regular bedtime and wake schedules. Other disorders Sleep disorders include narcolepsy, periodic limb movement disorder (PLMD), restless leg syndrome (RLS), upper airway resistance syndrome (UARS), and the circadian rhythm sleep disorders. Fatal familial insomnia, or FFI, an extremely rare genetic disease with no known treatment or cure, is characterized by increasing insomnia as one of its symptoms; ultimately sufferers of the disease stop sleeping entirely, before dying of the disease. Somnambulism, known as sleepwalking, is a sleeping disorder, especially among children. Sleep health Low quality sleep has been linked with health conditions like cardiovascular disease, obesity, and mental illness. While poor sleep is common among those with cardiovascular disease, some research indicates that poor sleep can be a contributing cause. Short sleep duration
the plant makes them counteract stress very effectively. There are three well-known and -studied classes of SOD metallic coenzymes that exist in plants. First, Fe SODs consist of two species, one homodimer (containing 1–2 g Fe) and one tetramer (containing 2–4 g Fe). They are thought to be the most ancient SOD metalloenzymes and are found within both prokaryotes and eukaryotes. Fe SODs are most abundantly localized inside plant chloroplasts, where they are indigenous. Second, Mn SODs consist of a homodimer and homotetramer species each containing a single Mn(III) atom per subunit. They are found predominantly in mitochondrion and peroxisomes. Third, Cu-Zn SODs have electrical properties very different from those of the other two classes. These are concentrated in the chloroplast, cytosol, and in some cases the extracellular space. Note that Cu-Zn SODs provide less protection than Fe SODs when localized in the chloroplast. Bacteria Human white blood cells use enzymes such as NADPH oxidase to generate superoxide and other reactive oxygen species to kill bacteria. During infection, some bacteria (e.g., Burkholderia pseudomallei) therefore produce superoxide dismutase to protect themselves from being killed. Biochemistry SOD out-competes damaging reactions of superoxide, thus protecting the cell from superoxide toxicity. The reaction of superoxide with non-radicals is spin-forbidden. In biological systems, this means that its main reactions are with itself (dismutation) or with another biological radical such as nitric oxide (NO) or with a transition-series metal. The superoxide anion radical () spontaneously dismutes to O2 and hydrogen peroxide () quite rapidly (~105 M−1s−1 at pH 7). SOD is necessary because superoxide reacts with sensitive and critical cellular targets. For example, it reacts with the NO radical, and makes toxic peroxynitrite. Because the uncatalysed dismutation reaction for superoxide requires two superoxide molecules to react with each other, the dismutation rate is second-order with respect to initial superoxide concentration. Thus, the half-life of superoxide, although very short at high concentrations (e.g., 0.05 seconds at 0.1mM) is actually quite long at low concentrations (e.g., 14 hours at 0.1 nM). In contrast, the reaction of superoxide with SOD is first order with respect to superoxide concentration. Moreover, superoxide dismutase has the largest kcat/KM (an approximation of catalytic efficiency) of any known enzyme (~7 x 109 M−1s−1), this reaction being limited only by the frequency of collision between itself and superoxide. That is, the reaction rate is "diffusion-limited". The high efficiency of superoxide dismutase seems necessary: even at the subnanomolar concentrations achieved by the high concentrations of SOD within cells, superoxide inactivates the citric acid cycle enzyme aconitase, can poison energy metabolism, and releases potentially toxic iron. Aconitase is one of several iron-sulfur-containing (de)hydratases in metabolic pathways shown to be inactivated by superoxide. Stability and folding mechanism SOD1 is an extremely stable protein. In the holo form (both copper and zinc bound) the melting point is > 90 °C. In the apo form (no copper or zinc bound) the melting point is ~60 °C. By differential scanning calorimetry (DSC), holo SOD1 unfolds by a two-state mechanism: from dimer to two unfolded monomers. In chemical denaturation experiments, holo SOD1 unfolds by a three-state mechanism with observation of a folded monomeric intermediate. Physiology Superoxide is one of the main reactive oxygen species in the cell. As a consequence, SOD serves a key antioxidant role. The physiological importance of SODs is illustrated by the severe pathologies evident in mice genetically engineered to lack these enzymes. Mice lacking SOD2 die several days after birth, amid massive oxidative stress. Mice lacking SOD1 develop a wide range of pathologies, including hepatocellular carcinoma, an acceleration of age-related muscle mass loss, an earlier incidence of cataracts, and a reduced lifespan. Mice lacking SOD3 do not show any obvious defects and exhibit a normal lifespan, though they are more sensitive to hyperoxic injury. Knockout mice of any SOD enzyme are more sensitive to the lethal effects of superoxide-generating compounds, such as paraquat and diquat (herbicides). Drosophila lacking SOD1 have a dramatically shortened lifespan, whereas flies lacking SOD2 die before birth. Depletion of SOD1 and SOD2 in the nervous system and muscles of Drosophila is associated with reduced lifespan. The accumulation of neuronal and muscular ROS appears to contribute to age-associated impairments. When overexpression of mitochondrial SOD2 is induced, the lifespan of adult Drosophila is extended. Among black garden ants (Lasius niger), the lifespan of queens is an order of magnitude greater than of workers despite no systematic nucleotide sequence difference between them. The SOD3 gene was found to be the most differentially over-expressed in the brains of queen vs worker ants. This finding raises the possibility of an important role of antioxidant function in modulating lifespan. SOD knockdowns in the worm C. elegans do not cause major physiological disruptions. However, the lifespan of C. elegans can be extended by superoxide/catalase mimetics suggesting that oxidative stress is a major determinant of the rate of aging. Knockout or null mutations in SOD1 are highly detrimental to aerobic growth in the budding yeast Saccharomyces cerevisiae and result in a dramatic reduction in post-diauxic lifespan. In wild-type S. cerevisiae, DNA damage rates increased 3-fold with age, but more than 5-fold in mutants deleted for either the SOD1	monomeric intermediate. Physiology Superoxide is one of the main reactive oxygen species in the cell. As a consequence, SOD serves a key antioxidant role. The physiological importance of SODs is illustrated by the severe pathologies evident in mice genetically engineered to lack these enzymes. Mice lacking SOD2 die several days after birth, amid massive oxidative stress. Mice lacking SOD1 develop a wide range of pathologies, including hepatocellular carcinoma, an acceleration of age-related muscle mass loss, an earlier incidence of cataracts, and a reduced lifespan. Mice lacking SOD3 do not show any obvious defects and exhibit a normal lifespan, though they are more sensitive to hyperoxic injury. Knockout mice of any SOD enzyme are more sensitive to the lethal effects of superoxide-generating compounds, such as paraquat and diquat (herbicides). Drosophila lacking SOD1 have a dramatically shortened lifespan, whereas flies lacking SOD2 die before birth. Depletion of SOD1 and SOD2 in the nervous system and muscles of Drosophila is associated with reduced lifespan. The accumulation of neuronal and muscular ROS appears to contribute to age-associated impairments. When overexpression of mitochondrial SOD2 is induced, the lifespan of adult Drosophila is extended. Among black garden ants (Lasius niger), the lifespan of queens is an order of magnitude greater than of workers despite no systematic nucleotide sequence difference between them. The SOD3 gene was found to be the most differentially over-expressed in the brains of queen vs worker ants. This finding raises the possibility of an important role of antioxidant function in modulating lifespan. SOD knockdowns in the worm C. elegans do not cause major physiological disruptions. However, the lifespan of C. elegans can be extended by superoxide/catalase mimetics suggesting that oxidative stress is a major determinant of the rate of aging. Knockout or null mutations in SOD1 are highly detrimental to aerobic growth in the budding yeast Saccharomyces cerevisiae and result in a dramatic reduction in post-diauxic lifespan. In wild-type S. cerevisiae, DNA damage rates increased 3-fold with age, but more than 5-fold in mutants deleted for either the SOD1 or SOD2 genes. Reactive oxygen species levels increase with age in these mutant strains and show a similar pattern to the pattern of DNA damage increase with age. Thus it appears that superoxide dismutase plays a substantial role in preserving genome integrity during aging in S. cerevisiae. SOD2 knockout or null mutations cause growth inhibition on respiratory carbon sources in addition to decreased post-diauxic lifespan. In the fission yeast Schizosaccharomyces pombe, deficiency of mitochondrial superoxide dismutase SOD2 accelerates chronological aging. Several prokaryotic SOD null mutants have been generated, including E. coli. The loss of periplasmic CuZnSOD causes loss of virulence and might be an attractive target for new antibiotics. Role in disease Mutations in the first SOD enzyme (SOD1) can cause familial amyotrophic lateral sclerosis (ALS, a form of motor neuron disease). The most common mutation in the U.S. is A4V, while the most intensely studied is G93A. The other two isoforms of SOD have not been linked to many human diseases, however, in mice inactivation of SOD2 causes perinatal lethality and inactivation of SOD1 causes hepatocellular carcinoma. Mutations in SOD1 can cause familial ALS (several pieces of evidence also show that wild-type SOD1, under conditions of cellular stress, is implicated in a significant fraction of sporadic ALS cases, which represent 90% of ALS patients.), by a mechanism that is presently not understood, but not due to loss of enzymatic activity or a decrease in the conformational stability of the SOD1 protein. Overexpression of SOD1 has been linked to the neural disorders seen in Down syndrome. In patients with thalassemia, SOD will increase as a form of compensation mechanism. However, in the chronic stage, SOD does not seem to be sufficient and tends to decrease due to the destruction of proteins from the massive reaction of oxidant-antioxidant. In mice, the extracellular superoxide dismutase (SOD3, ecSOD) contributes to the development of hypertension. Diminished SOD3 activity has been linked to lung diseases such as Acute Respiratory Distress Syndrome (ARDS) or Chronic obstructive pulmonary disease (COPD). Superoxide dismutase is also not expressed in neural crest cells in the developing fetus. Hence, high levels of free radicals can cause damage to them and induce dysraphic anomalies (neural tube defects). Pharmacological activity SOD has powerful antiinflammatory activity. For example, SOD is a highly effective experimental treatment of chronic inflammation in colitis. Treatment with SOD decreases reactive oxygen species generation and oxidative stress and, thus, inhibits endothelial activation. Therefore, such antioxidants may be important new therapies for the treatment of inflammatory bowel disease. Likewise, SOD has multiple pharmacological activities. E.g., it ameliorates cis-platinum-induced nephrotoxicity in rodents. As "Orgotein" or "ontosein", a pharmacologically-active purified bovine liver SOD, it is also effective in the treatment of urinary tract inflammatory disease in man. For a time, bovine liver SOD even had regulatory approval in several European countries for such use. This was cut short by concerns about prion disease. An SOD-mimetic agent, TEMPOL, is currently in clinical trials for radioprotection and to prevent radiation-induced dermatitis. TEMPOL and similar SOD-mimetic nitroxides exhibit a multiplicity of actions in diseases involving oxidative stress. Cosmetic uses SOD may reduce free radical damage to skin—for example, to reduce fibrosis following radiation for breast cancer. Studies of this kind must be regarded as tentative, however, as there were not adequate controls in the study including a lack of randomization, double-blinding, or placebo. Superoxide dismutase is known to reverse fibrosis, possibly through de-differentiation of myofibroblasts back to fibroblasts. Commercial sources SOD is commercially obtained from marine phytoplankton, bovine liver, horseradish, cantaloupe, and certain bacteria. For therapeutic purpose, SOD is usually injected locally. There is no evidence that ingestion of unprotected SOD or SOD-rich foods can have any physiological effects, as all ingested SOD is broken down into amino acids before
For example, the first four odd numbers form the sequence (1, 3, 5, 7). This notation is used for infinite sequences as well. For instance, the infinite sequence of positive odd integers is written as (1, 3, 5, 7, ...). Because notating sequences with ellipsis leads to ambiguity, listing is most useful for customary infinite sequences which can be easily recognized from their first few elements. Other ways of denoting a sequence are discussed after the examples. Examples The prime numbers are the natural numbers greater than 1 that have no divisors but 1 and themselves. Taking these in their natural order gives the sequence (2, 3, 5, 7, 11, 13, 17, ...). The prime numbers are widely used in mathematics, particularly in number theory where many results related to them exist. The Fibonacci numbers comprise the integer sequence whose elements are the sum of the previous two elements. The first two elements are either 0 and 1 or 1 and 1 so that the sequence is (0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...). Other examples of sequences include those made up of rational numbers, real numbers and complex numbers. The sequence (.9, .99, .999, .9999, ...), for instance, approaches the number 1. In fact, every real number can be written as the limit of a sequence of rational numbers (e.g. via its decimal expansion). As another example, is the limit of the sequence (3, 3.1, 3.14, 3.141, 3.1415, ...), which is increasing. A related sequence is the sequence of decimal digits of , that is, (3, 1, 4, 1, 5, 9, ...). Unlike the preceding sequence, this sequence does not have any pattern that is easily discernible by inspection. The On-Line Encyclopedia of Integer Sequences comprises a large list of examples of integer sequences. Indexing Other notations can be useful for sequences whose pattern cannot be easily guessed or for sequences that do not have a pattern such as the digits of . One such notation is to write down a general formula for computing the nth term as a function of n, enclose it in parentheses, and include a subscript indicating the set of values that n can take. For example, in this notation the sequence of even numbers could be written as . The sequence of squares could be written as . The variable n is called an index, and the set of values that it can take is called the index set. It is often useful to combine this notation with the technique of treating the elements of a sequence as individual variables. This yields expressions like , which denotes a sequence whose nth element is given by the variable . For example: One can consider multiple sequences at the same time by using different variables; e.g. could be a different sequence than . One can even consider a sequence of sequences: denotes a sequence whose mth term is the sequence . An alternative to writing the domain of a sequence in the subscript is to indicate the range of values that the index can take by listing its highest and lowest legal values. For example, the notation denotes the ten-term sequence of squares . The limits and are allowed, but they do not represent valid values for the index, only the supremum or infimum of such values, respectively. For example, the sequence is the same as the sequence , and does not contain an additional term "at infinity". The sequence is a bi-infinite sequence, and can also be written as . In cases where the set of indexing numbers is understood, the subscripts and superscripts are often left off. That is, one simply writes for an arbitrary sequence. Often, the index k is understood to run from 1 to ∞. However, sequences are frequently indexed starting from zero, as in In some cases, the elements of the sequence are related naturally to a sequence of integers whose pattern can be easily inferred. In these cases, the index set may be implied by a listing of the first few abstract elements. For instance, the sequence of squares of odd numbers could be denoted in any of the following ways. Moreover, the subscripts and superscripts could have been left off in the third, fourth, and fifth notations, if the indexing set was understood to be the natural numbers. In the second and third bullets, there is a well-defined sequence , but it is not the same as the sequence denoted by the expression. Defining a sequence by recursion Sequences whose elements are related to the previous elements in a straightforward way are often defined using recursion. This is in contrast to the definition of sequences of elements as functions of their positions. To define a sequence by recursion, one needs a rule, called recurrence relation to construct each element in terms of the ones before it. In addition, enough initial elements must be provided so that all subsequent elements of the sequence can be computed by successive applications of the recurrence relation. The Fibonacci sequence is a simple classical example, defined by the recurrence relation with initial terms and . From this, a simple computation shows that the first ten terms of this sequence are 0, 1, 1, 2, 3, 5, 8, 13, 21, and 34. A complicated example of a sequence defined by a recurrence relation is Recamán's sequence, defined by the recurrence relation with initial term A linear recurrence with constant coefficients is a recurrence relation of the form where are constants. There is a general method for expressing the general term of such a sequence as a function of ; see Linear recurrence. In the case of the Fibonacci sequence, one has and the resulting function of is given by Binet's formula. A holonomic sequence is a sequence defined by a recurrence relation of the form where are polynomials in . For most holonomic sequences, there is no explicit formula for expressing explicitly as a function of . Nevertheless, holonomic sequences play an important role in various areas of mathematics. For example, many special functions have a Taylor series whose sequence of coefficients is holonomic. The use of the recurrence relation allows a fast computation of values of such special functions. Not all sequences can be specified by a recurrence relation. An example is the sequence of prime numbers in their natural order (2, 3, 5, 7, 11, 13, 17, ...). Formal definition and basic properties There are many different notions of sequences in mathematics, some of which (e.g., exact sequence) are not covered by the definitions and notations introduced below. Definition In this article, a sequence is formally defined as a function whose domain is an interval of integers. This definition covers several different uses of the word "sequence", including one-sided infinite sequences, bi-infinite sequences, and finite sequences (see below for definitions of these kinds of sequences). However, many authors use a narrower definition by requiring the domain of a sequence to be the set of natural numbers. This narrower definition has the disadvantage that it rules out finite sequences and bi-infinite sequences, both of which are usually called sequences in standard mathematical practice. Another disadvantage is that, if one removes the first terms of a sequence, one needs reindexing the remainder terms for fitting this definition. In some contexts, to shorten exposition, the codomain of the sequence is fixed by context, for example by requiring it to be the set R of real numbers, the set C of complex numbers, or a topological space. Although sequences are a type of function, they are usually distinguished notationally from functions in that the input is written as a subscript rather than in parentheses, that is, rather than . There are terminological differences as well: the value of a sequence at the lowest input (often 1) is called the "first element" of the sequence, the value at the second smallest input (often 2) is called the "second element", etc. Also, while a function abstracted from its input is usually denoted by a single letter, e.g. f, a sequence abstracted from its input is usually written by a notation such as , or just as Here is the domain, or index set, of the sequence. Sequences and their limits (see below) are important concepts for studying topological spaces. An important generalization of sequences is the concept of nets. A net is a function from a (possibly uncountable) directed set to a topological space. The notational conventions for sequences normally apply to nets as well. Finite and infinite The length of a sequence is defined as the number of terms in the sequence.	but it is not the same as the sequence denoted by the expression. Defining a sequence by recursion Sequences whose elements are related to the previous elements in a straightforward way are often defined using recursion. This is in contrast to the definition of sequences of elements as functions of their positions. To define a sequence by recursion, one needs a rule, called recurrence relation to construct each element in terms of the ones before it. In addition, enough initial elements must be provided so that all subsequent elements of the sequence can be computed by successive applications of the recurrence relation. The Fibonacci sequence is a simple classical example, defined by the recurrence relation with initial terms and . From this, a simple computation shows that the first ten terms of this sequence are 0, 1, 1, 2, 3, 5, 8, 13, 21, and 34. A complicated example of a sequence defined by a recurrence relation is Recamán's sequence, defined by the recurrence relation with initial term A linear recurrence with constant coefficients is a recurrence relation of the form where are constants. There is a general method for expressing the general term of such a sequence as a function of ; see Linear recurrence. In the case of the Fibonacci sequence, one has and the resulting function of is given by Binet's formula. A holonomic sequence is a sequence defined by a recurrence relation of the form where are polynomials in . For most holonomic sequences, there is no explicit formula for expressing explicitly as a function of . Nevertheless, holonomic sequences play an important role in various areas of mathematics. For example, many special functions have a Taylor series whose sequence of coefficients is holonomic. The use of the recurrence relation allows a fast computation of values of such special functions. Not all sequences can be specified by a recurrence relation. An example is the sequence of prime numbers in their natural order (2, 3, 5, 7, 11, 13, 17, ...). Formal definition and basic properties There are many different notions of sequences in mathematics, some of which (e.g., exact sequence) are not covered by the definitions and notations introduced below. Definition In this article, a sequence is formally defined as a function whose domain is an interval of integers. This definition covers several different uses of the word "sequence", including one-sided infinite sequences, bi-infinite sequences, and finite sequences (see below for definitions of these kinds of sequences). However, many authors use a narrower definition by requiring the domain of a sequence to be the set of natural numbers. This narrower definition has the disadvantage that it rules out finite sequences and bi-infinite sequences, both of which are usually called sequences in standard mathematical practice. Another disadvantage is that, if one removes the first terms of a sequence, one needs reindexing the remainder terms for fitting this definition. In some contexts, to shorten exposition, the codomain of the sequence is fixed by context, for example by requiring it to be the set R of real numbers, the set C of complex numbers, or a topological space. Although sequences are a type of function, they are usually distinguished notationally from functions in that the input is written as a subscript rather than in parentheses, that is, rather than . There are terminological differences as well: the value of a sequence at the lowest input (often 1) is called the "first element" of the sequence, the value at the second smallest input (often 2) is called the "second element", etc. Also, while a function abstracted from its input is usually denoted by a single letter, e.g. f, a sequence abstracted from its input is usually written by a notation such as , or just as Here is the domain, or index set, of the sequence. Sequences and their limits (see below) are important concepts for studying topological spaces. An important generalization of sequences is the concept of nets. A net is a function from a (possibly uncountable) directed set to a topological space. The notational conventions for sequences normally apply to nets as well. Finite and infinite The length of a sequence is defined as the number of terms in the sequence. A sequence of a finite length n is also called an n-tuple. Finite sequences include the empty sequence ( ) that has no elements. Normally, the term infinite sequence refers to a sequence that is infinite in one direction, and finite in the other—the sequence has a first element, but no final element. Such a sequence is called a singly infinite sequence or a one-sided infinite sequence when disambiguation is necessary. In contrast, a sequence that is infinite in both directions—i.e. that has neither a first nor a final element—is called a bi-infinite sequence, two-way infinite sequence, or doubly infinite sequence. A function from the set Z of all integers into a set, such as for instance the sequence of all even integers ( ..., −4, −2, 0, 2, 4, 6, 8, ... ), is bi-infinite. This sequence could be denoted . Increasing and decreasing A sequence is said to be monotonically increasing if each term is greater than or equal to the one before it. For example, the sequence is monotonically increasing if and only if an+1 an for all n ∈ N. If each consecutive term is strictly greater than (>) the previous term then the sequence is called strictly monotonically increasing. A sequence is monotonically decreasing, if each consecutive term is less than or equal to the previous one, and strictly monotonically decreasing, if each is strictly less than the previous. If a sequence is either increasing or decreasing it is called a monotone sequence. This is a special case of the more general notion of a monotonic function. The terms nondecreasing and nonincreasing are often used in place of increasing and decreasing in order to avoid any possible confusion with strictly increasing and strictly decreasing, respectively. Bounded If the sequence of real numbers (an) is such that all the terms are less than some real number M, then the sequence is said to be bounded from above. In other words, this means that there exists M such that for all n, an ≤ M. Any such M is called an upper bound. Likewise, if, for some real m, an ≥ m for all n greater than some N, then the sequence is bounded from below and any such m is called a lower bound. If a sequence is both bounded from above and bounded from below, then the sequence is said to be bounded. Subsequences A subsequence of a given sequence is a sequence formed from the given sequence by deleting some of the elements without disturbing the relative positions of the remaining elements. For instance, the sequence of positive even integers (2, 4, 6, ...) is a subsequence of the positive integers (1, 2, 3, ...). The positions of some elements change when other elements are deleted. However, the relative positions are preserved. Formally, a subsequence of the sequence is any sequence of the form , where is a strictly increasing sequence of positive integers. Other types of sequences Some other types of sequences that are easy to define include: An integer sequence is a sequence whose terms are integers. A polynomial sequence is a sequence whose terms are polynomials. A positive integer sequence is sometimes called multiplicative, if anm = an am for all pairs n, m such that n and m are coprime. In other instances, sequences are often called multiplicative, if an = na1 for all n. Moreover, a multiplicative Fibonacci sequence satisfies the recursion relation an = an−1 an−2. A binary sequence is a sequence whose terms have one of two discrete values, e.g. base 2 values (0,1,1,0, ...), a series of coin tosses (Heads/Tails) H,T,H,H,T, ..., the answers to a set of True or False questions (T, F, T, T, ...), and so on. Limits and convergence An important property of a sequence is convergence. If a sequence converges, it converges to a particular value known as the limit. If a sequence converges to some limit, then it is convergent. A sequence that does not converge is divergent. Informally, a sequence has a limit if the elements of the sequence become closer and closer to some value (called the limit of the sequence), and they become and remain arbitrarily close to , meaning that given a real number greater than zero, all but a finite number of the elements of the sequence have a distance from less than . For example, the sequence shown to the right converges to the value 0. On the other hand, the sequences (which begins 1, 8, 27, …) and (which begins −1, 1, −1, 1, …) are both divergent. If a sequence converges, then the value it converges to is unique. This value is called
more serious. Unlike haiku, do not include a (cutting word), and do not generally include a , or season word. Form and content is named after Edo period poet , whose collection launched the genre into the public consciousness. A typical example from the collection: This , which can also be translated "Catching him / I see the robber / is my son," is not so much a personal experience of the author as an example of a type of situation (provided by a short comment called a or fore-verse, which usually prefaces a number of examples) and/or a brief or witty rendition of an incident from history or the arts (plays, songs, tales, poetry, etc.). English-language publications In the 1970s, Michael McClintock edited Seer Ox: American Senryu Magazine. In 1993, Michael Dylan Welch edited and published Fig Newtons: to Go, the first anthology of English-language . Prune Juice, a journal of	Award for best unpublished . Since about 1990, the Haiku Poets of Northern California has been running a contest, as part of its San Francisco International Haiku and Senryu Contest. See also References Bibliography and further reading J C Brown, Senryu: Poems of the People, Simon & Schuster Ltd, 1991, R. H. Blyth, translator, Senryu: Japanese Satirical Verses. 1949, The Hokuseido Press, . Includes black and white sketches and some colored plates R. H. Blyth, translator, Japanese Humour. 1957, Japan Travel Bureau R. H. Blyth, translator, Japanese Life and Character in Senryu. 1960, The Hokuseido Press R. H. Blyth, translator, Oriental Humour. 1960, The Hokuseido Press R. H. Blyth, translator, Edo Satirical Verse Anthologies. 1961, The Hokuseido Press Robin D. Gill, compiler and translator, Octopussy, Dry Kidney & Blue Spots – dirty themes from 18-19c Japanese poems, Paraverse Press, 2007. . Chronicles 1,300 – Blyth mentioned that he could only introduce what the censors allowed; these are the type of that were not allowed. Lorraine Ellis Harr (tombo), Selected Senryu. 1976, J & C Transcripts. One of the earliest English-language -only publications James Day Hodgson, American Senryu. 1992, The Japan Times, Howard S. Levy and Junko Ohsawa, One Hundred Senryu Selections. 1979, So. Pasadena, CA, Langstaff Publications, Alan Pizzarelli, Senryu Magazine. 2001, River Willow. Although this book looks like a regular journal, it is the effort of Alan Pizzarelli only, done as a parody of haiku journals. Makoto Ueda, Light Verse from the Floating World: An Anthology of Premodern Japanese Senryu, Columbia University Press, 1999. cloth Michael Dylan Welch, ed. Fig Newtons: Senryu to Go, Press Here, 1993 (the first anthology of English-language ) External links 'A Brief Survey
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American actor and producer 1970 – Damian Mori, Australian footballer and manager 1971 – Jenna Elfman, American actress and producer 1972 – Jamal Anderson, American football player and sportscaster 1972 – Ari Behn, Danish-Norwegian author and playwright (d. 2019) 1972 – John Campbell, American bass player and songwriter 1972 – Mayumi Kojima, Japanese singer-songwriter 1972 – José Lima, Dominican-American baseball player (d. 2010) 1974 – Jeremy Giambi, American baseball player 1974 – Tom Greatrex, English politician 1974 – Ben Phillips, English cricketer 1974 – Daniel Wu, American–born Hong Kong actor, director, and producer 1975 – Jay Asher, American author 1975 – Marion Cotillard, French-American actress and singer 1975 – Carlos Guillén, Venezuelan baseball player 1975 – Laure Pequegnot, French skier 1975 – Christopher Jackson, American actor, singer, musician, and composer 1976 – Georgie Bingham, British radio and television presenter 1977 – Roy Carroll, Northern Irish goalkeeper and manager 1977 – Nick Curran, American singer-songwriter, guitarist, and producer (d. 2012) 1978 – Małgorzata Glinka-Mogentale, Polish female volleyball player 1979 – Cameron Bruce, Australian footballer and coach 1979 – Andy van der Meyde, Dutch footballer 1980 – Martina Hingis, Czechoslovakia-born Swiss tennis player 1980 – Milagros Sequera, Venezuelan tennis player 1981 – Cecelia Ahern, Irish author 1981 – Dominique Moceanu, American gymnast 1982 – Lacey Chabert, American actress 1982 – Ryane Clowe, Canadian ice hockey player. 1982 – Kieran Culkin, American actor. 1982 – Yan Stastny, Canadian ice hockey player 1982 – Dmytro Boyko, Ukrainian footballer 1983 – Boniek Forbes, Guinea-Bissau footballer 1983 – Andreea Răducan, Romanian gymnast 1984 – Georgios Eleftheriou, Greek footballer 1984 – T-Pain, American rapper, producer, and actor 1985 – Adam Cooney, Australian footballer 1985 – David Gower, Australian rugby league player 1985 – Téa Obreht, Serbian-American author 1985 – Cristian Rodríguez, Uruguayan footballer 1986 – Olivier Giroud, French footballer 1986 – Martin Guptill, New Zealand cricketer 1986 – Ben Lovett, Welsh musician and songwriter 1986 – Cristián Zapata, Colombian footballer 1987 – Aida Garifullina, Russian operatic soprano 1988 – Eglė Staišiūnaitė, Lithuanian hurdler 1989 – André Weis, German footballer 1991 – Thomas Röhler, German javelin thrower 1992 – Ezra Miller, American actor and singer 1994 – Aliya Mustafina, Russian gymnast 1996 – Jacob Host, Australian rugby league player 1997 – Yana Kudryavtseva, Russian gymnast 1997 – Max Verstappen, Dutch Formula One driver 1998 – Yui Imaizumi, Japanese tarento 1998 – Trevi Moran, American youtuber and singer 2002 – Maddie Ziegler, American dancer and actress 2002 – Levi Miller, Australian actor and model Deaths Pre-1600 420 – Jerome, Roman priest, theologian, and saint 653 – Honorius of Canterbury, Italian archbishop and saint 940 – Fan Yanguang, Chinese general 954 – Louis IV of France (b. 920) 1101 – Anselm IV, Italian archbishop 1246 – Yaroslav II of Vladimir (b. 1191) 1288 – Leszek II the Black, Polish prince, Duke of Łęczyca, Sieradz, Kraków, Sandomierz (b. 1241) 1440 – Reginald Grey, 3rd Baron Grey de Ruthyn, Welsh soldier and politician (b. 1362) 1487 – John Sutton, 1st Baron Dudley, English politician, Lord Lieutenant of Ireland (b. 1400) 1551 – Ōuchi Yoshitaka, Japanese daimyō (b. 1507) 1560 – Melchior Cano, Spanish theologian (b. 1525) 1572 – Francis Borgia, 4th Duke of Gandía, Spanish priest and saint, 3rd Superior General of the Society of Jesus (b. 1510) 1581 – Hubert Languet, French diplomat and reformer (b. 1518) 1601–1900 1626 – Nurhaci, Chinese emperor (b. 1559) 1628 – Fulke Greville, 1st Baron Brooke, English poet and politician, Chancellor of the Exchequer (b. 1554) 1770 – Thomas Robinson, 1st Baron Grantham, English politician and diplomat, Secretary of State for the Southern Department (b. 1695) 1770 – George Whitefield, English-American priest and theologian (b. 1714) 1865 – Samuel David Luzzatto, Italian poet and scholar (b. 1800) 1866 – Per Gustaf Svinhufvud af Qvalstad, Swedo-Finnish treasurer of Tavastia province, manor host, and paternal grandfather of President P. E. Svinhufvud (b. 1804) 1891 – Georges Ernest Boulanger, French general and politician, French Minister of War (b. 1837) 1897 – Thérèse of Lisieux, French nun and saint (b. 1873) 1901–present 1910 – Maurice Lévy, French mathematician and engineer (b. 1838) 1942 – Hans-Joachim Marseille, German captain and pilot (b. 1919) 1943 – Franz Oppenheimer, German-American sociologist and economist (b. 1864) 1946 – Takashi Sakai, Japanese general and politician, Governor of Hong Kong (b. 1887) 1955 – James Dean, American actor (b. 1931) 1959 – Henry Barwell, Australian politician, 28th Premier of South Australia (b. 1877) 1961 – Onésime Gagnon, Canadian scholar and politician, 20th Lieutenant Governor of Quebec (b. 1888) 1973 – Peter Pitseolak, Canadian photographer and author (b. 1902) 1974 – Carlos Prats, Chilean general and politician, Chilean Minister of Defense (b. 1915) 1977 – Mary Ford, American singer and guitarist (b. 1924) 1978 – Edgar Bergen, American actor and ventriloquist (b. 1903) 1985 – Charles Francis Richter, American seismologist and physicist (b. 1900) 1985 – Simone Signoret, French actress (b. 1921) 1986 – Nicholas Kaldor, Hungarian-British economist (b. 1908) 1987 – Alfred Bester, American author and screenwriter (b. 1913) 1988 – Al Holbert, American race car driver (b. 1946) 1989 – Virgil Thomson, American composer and critic (b. 1896) 1990 – Rob Moroso, American race car driver (b. 1968) 1990 – Alice Parizeau, Polish-Canadian journalist and author (b. 1930) 1990 – Patrick White, Australian novelist, poet, and playwright, Nobel Prize laureate (b. 1912) 1991 – Toma Zdravković, Serbian singer-songwriter (b. 1938) 1994 – André Michel Lwoff, French microbiologist and virologist, Nobel Prize laureate (b. 1902) 1998 – Marius Goring, English actor (b. 1912) 1998 – Dan Quisenberry, American baseball player and poet (b. 1953) 1998 – Robert Lewis Taylor, American soldier and author (b. 1912) 2002 – Göran Kropp, Swedish race car driver and mountaineer (b. 1966) 2002 – Hans-Peter Tschudi, Swiss lawyer and politician, 63rd President of the Swiss Confederation (b. 1913) 2003 – Yusuf Bey, American activist, founded Your Black Muslim Bakery (b. 1935) 2003 – Ronnie Dawson, American singer-songwriter and guitarist (b. 1939) 2003 – Robert Kardashian, American lawyer and businessman (b. 1944) 2004 – Gamini Fonseka, Sri Lankan actor, director, and politician (b. 1936) 2004 – Jacques Levy, American director and songwriter (b. 1935) 2004 – Michael Relph, English director, producer, and screenwriter (b. 1915) 2008 – J. B. Jeyaretnam, Singaporean lawyer and politician (b. 1926) 2010 – Stephen J. Cannell, American screenwriter and producer (b. 1941) 2011 – Anwar al-Awlaki, American-Yemeni terrorist (b. 1971) 2011 – Ralph M. Steinman, Canadian-American immunologist and biologist, Nobel Prize laureate (b. 1943) 2012 – Turhan Bey, Austrian actor and producer (b. 1922) 2012 – Barry Commoner, American biologist, academic, and politician (b. 1917) 2012 – Bobby Jaggers, American wrestler and engineer (b. 1948) 2012 – Clara Stanton Jones, American librarian (b. 1913) 2012 – Barbara Ann Scott, Canadian-American figure skater (b. 1928) 2012 – Boris Šprem, Croatian lawyer and politician, 8th Speaker of the Croatian Parliament (b. 1956) 2013 – Janet Powell, Australian educator and politician (b. 1942) 2014 – Molvi Iftikhar Hussain Ansari, Indian cleric and politician (b. 1940) 2014 – Martin Lewis Perl, American physicist and engineer, Nobel Prize laureate (b. 1927) 2015 – Guido Altarelli, Italian-Swiss physicist and academic (b. 1941) 2015 – Claude Dauphin, French businessman (b. 1951) 2015 – Göran Hägg, Swedish author and critic (b. 1947) 2017 – Monty Hall, American game show host (b. 1921) 2018 – Kim Larsen, Danish rock musician (b. 1945) 2018 – Geoffrey Hayes, British television presenter and actor (b. 1942) 2018 – Sonia Orbuch, Polish resistance fighter during the Second World War and Holocaust educator. (b. 1925) 2019 – Victoria Braithwaite, British research scientist who proved fish feel pain	baggage train. 1399 – Henry IV is proclaimed king of England. 1520 – Suleiman the Magnificent is proclaimed sultan of the Ottoman Empire. 1541 – Spanish conquistador Hernando de Soto and his forces enter Tula territory in present-day western Arkansas, encountering fierce resistance. 1551 – A coup by the military establishment of Japan's Ōuchi clan forces their lord to commit suicide, and their city is burned. 1601–1900 1744 – War of the Austrian Succession: France and Spain defeat Sardinia at the Battle of Madonna dell'Olmo, but soon have to withdraw from Sardinia anyway. 1791 – The first performance of Mozart's opera The Magic Flute takes place two months before his death. 1791 – France's National Constituent Assembly is dissolved, to be replaced the next day by the National Legislative Assembly. 1882 – Thomas Edison's first commercial hydroelectric power plant (later known as Appleton Edison Light Company) begins operation. 1888 – Jack the Ripper kills his third and fourth victims, Elizabeth Stride and Catherine Eddowes. 1901–present 1906 – The Royal Galician Academy, the Galician language's biggest linguistic authority, starts working in La Coruña, Spain. 1907 – The McKinley National Memorial, the final resting place of assassinated U.S. President William McKinley and his family, is dedicated in Canton, Ohio. 1909 – The Cunard Line's RMS Mauretania makes a record-breaking westbound crossing of the Atlantic, that will not be bettered for 20 years. 1915 – World War I: Radoje Ljutovac becomes the first soldier in history to shoot down an enemy aircraft with ground-to-air fire. 1935 – The Hoover Dam, astride the border between the U.S. states of Arizona and Nevada, is dedicated. 1938 – Britain, France, Germany and Italy sign the Munich Agreement, whereby Germany annexes the Sudetenland region of Czechoslovakia. 1938 – The League of Nations unanimously outlaws "intentional bombings of civilian populations". 1939 – World War II: General Władysław Sikorski becomes prime minister of the Polish government-in-exile. 1939 – NBC broadcasts the first televised American football game. 1941 – World War II: The Babi Yar massacre comes to an end. 1943 – The United States Merchant Marine Academy is dedicated by President Roosevelt. 1944 – The Germans commence a counter offensive to retake the Nijmegen salient, this having been captured by the allies during Operation Market Garden. 1945 – The Bourne End rail crash, in Hertfordshire, England, kills 43. 1947 – The 1947 World Series begins. It is the first to be televised, to include an African-American player, to exceed $2 million in receipts, to see a pinch-hit home run, and to have six umpires on the field. 1947 – Pakistan joins the United Nations. 1949 – The Berlin Airlift ends. 1954 – The U.S. Navy submarine is commissioned as the world's first nuclear-powered vessel. 1962 – James Meredith enters the University of Mississippi, defying racial segregation rules. 1966 – Bechuanaland declares its independence, and becomes the Republic of Botswana. 1968 – The Boeing 747 is rolled out and shown to the public for the first time. 1970 – Jordan makes a deal with the PFLP for the release of the remaining hostages from the Dawson's Field hijackings. 1975 – Malév Flight 240 crashes into the Mediterranean Sea while on approach to Beirut International Airport in Beirut, Lebanon, killing 60. 1978 – Finnair Flight 405 aircraft was hijacked by Aarno Lamminparras in Oulu, Finland. 1980 – Ethernet specifications are published by Xerox working with Intel and Digital Equipment Corporation. 1993 – The 6.2 Latur earthquake shakes Maharashtra, India with a maximum Mercalli intensity of VIII (Severe) killing 9,748 and injuring 30,000. 1999 – The Tokaimura nuclear accident causes the deaths of two technicians in Japan's second-worst nuclear accident. 2000 – Israeli-Palestinian conflict: Twelve-year-old Muhammad al-Durrah is shot and killed on the second day of the Second Intifada. 2005 – Controversial drawings of Muhammad are printed in a Danish newspaper. 2009 – The 7.6 Sumatra earthquake leaves 1,115 people dead. 2016 – Hurricane Matthew becomes a Category 5 hurricane, making it the strongest hurricane to form in the Caribbean Sea since 2007. 2016 – Two paintings with a combined value of $100 million are recovered after having been stolen from the Van Gogh Museum in 2002. Births Pre-1600 1207 – Rumi, Persian mystic and poet (d. 1273) 1227 – Pope Nicholas IV (d. 1292) 1530 – Girolamo Mercuriale, Italian philologist and physician (d. 1606) 1550 – Michael Maestlin, German astronomer and mathematician (d. 1631) 1601–1900 1622 – Johann Sebastiani, German composer (d. 1683) 1689 – Jacques Aubert, French violinist and composer (d. 1753) 1700 – Stanisław Konarski, Polish monk, poet, and playwright (d. 1773) 1710 – John Russell, 4th Duke of Bedford, English politician, Lord President of the Council (d. 1771) 1714 – Étienne Bonnot de Condillac, French epistemologist and philosopher (d. 1780) 1732 – Jacques Necker, Swiss-French politician, Prime Minister of France (d. 1804) 1743 – Christian Ehregott Weinlig, German cantor and composer (d. 1813) 1765 – José María Morelos, Mexican priest and general (d. 1815) 1800 – Decimus Burton, English architect, designed the Pharos Lighthouse (d. 1881) 1813 – John Rae, Scottish physician and explorer (d. 1893) 1814 – Lucinda Hinsdale Stone, American feminist, educator, and philanthropist (d. 1900) 1827 – Ellis H. Roberts, American journalist and politician, 20th Treasurer of the United States (d. 1918) 1832 – Ann Jarvis, American activist, co-founded Mother's Day (d. 1905) 1836 – Remigio Morales Bermúdez, Peruvian politician, 56th President of Peru (d. 1894) 1852 – Charles Villiers Stanford, Irish composer, conductor, and educator (d. 1924) 1861 – William Wrigley, Jr., American businessman, founded Wrigley Company (d. 1932) 1863 – Reinhard Scheer, German admiral (d. 1928) 1870 – Thomas W. Lamont, American banker and philanthropist (d. 1948) 1870 – Jean Baptiste Perrin, French-American physicist and chemist, Nobel Prize laureate (d. 1942) 1882 – Hans Geiger, German physicist and academic (d. 1945) 1883 – Bernhard Rust, German educator and politician (d. 1945) 1883 – Nora Stanton Blatch Barney, American civil engineer, architect, and suffragist (d. 1971) 1887 – Lil Dagover, Indonesian-German actress (d. 1980) 1893 – Lansdale Ghiselin Sasscer, American lieutenant, lawyer, and politician (d. 1964) 1895 – Lewis Milestone, Moldovan-American director, producer, and screenwriter (d. 1980) 1897 – Alfred Wintle, Russian-English soldier and politician (d. 1966) 1897 – Charlotte Wolff, German-English physician and psychotherapist (d. 1986) 1898 – Renée Adorée, French-American actress (d. 1933) 1898 – Princess Charlotte, Duchess of Valentinois (d. 1977) 1898 – Edgar Parin d'Aulaire, German-American author and illustrator (d. 1986) 1901–present 1901 – Thelma Terry, American bassist and bandleader (d. 1966) 1904 – Waldo Williams, Welsh poet and academic (d. 1971) 1905 – Nevill Francis Mott, English physicist and
doing this, he tries to break the boundary between "us" (the people watching on TV) and "them" (those before the camera) by becoming one of them (albeit for just a month). Living with Corruption, his latest documentary to be shown on CNN, describes the shocking reality of how corruption is spread across society both in Sierra Leone and Kenya, affecting mostly the poor. In 2010, Samura investigated attitudes to homosexuality in Africa in the Dispatches documentary Africa's Last Taboo, produced for Channel 4. Samura is also one of the directors of Insight News TV, an independent television production company in the UK focused on international current affairs programming. Samura attended the Methodist Boys High School	Award and a Peabody. Exodus from Africa shows the harrowing effort by the best of young African male blood to break through to Europe via death- and danger-ridden paths from Sierra Leone and Nigeria, via Mali, the Sahara desert, Algeria, and Morocco through the Strait of Gibraltar to Spain. In his recent two projects Living with Hunger and Living with Refugees (nominated for an Emmy award), he takes reality television to its extreme, becoming the central character in the films by living the lifestyle of an Ethiopian villager and Sudanese refugee respectively; in doing this, he tries to break the boundary between "us" (the people watching on TV) and "them" (those before the camera) by becoming one of them (albeit for just a month). Living with Corruption, his latest documentary to be shown on CNN, describes the shocking reality of how corruption is spread across society both in Sierra Leone and Kenya, affecting mostly the poor. In 2010, Samura investigated attitudes to homosexuality in Africa in the Dispatches documentary Africa's
pilot inexperience as probable causes of the crash. Wozniak did not immediately return to Apple after recovering from the airplane crash, seeing it as a good reason to leave. Infinite Loop characterized this time: "Coming out of the semi-coma had been like flipping a reset switch in Woz's brain. It was as if in his thirty-year old body he had regained the mind he'd had at eighteen before all the computer madness had begun. And when that happened, Woz found he had little interest in engineering or design. Rather, in an odd sort of way, he wanted to start over fresh." UC Berkeley and US Festivals Later in 1981, after recovering from the plane crash, Wozniak enrolled back at UC Berkeley to complete his degree. Because his name was well known at this point, he enrolled under the name Rocky Raccoon Clark, which is the name listed on his diploma, although he did not officially receive his degree in electrical engineering and computer science until 1987. In May 1982 and 1983, Wozniak, with help from professional concert promoter Bill Graham, founded the company Unuson, an abbreviation of "unite us in song", which sponsored two US Festivals, with "US" pronounced like the pronoun, not as initials. Initially intended to celebrate evolving technologies, the festivals ended up as a technology exposition and a rock festival as a combination of music, computers, television, and people. After losing several million dollars on the 1982 festival, Wozniak stated that unless the 1983 event turned a profit, he would end his involvement with rock festivals and get back to designing computers. Later that year, Wozniak returned to Apple product development, desiring no more of a role than that of an engineer and a motivational factor for the Apple workforce. Return to Apple product development In the mid-1980s he designed the Apple Desktop Bus, a proprietary bit-serial peripheral bus that became the basis of all Macintosh and NeXT computer models. Starting in the mid-1980s, as the Macintosh experienced slow but steady growth, Apple's corporate leadership, including Steve Jobs, increasingly disrespected its flagship cash cow Apple II seriesand Wozniak along with it. The Apple II divisionother than Wozniakwas not invited to the Macintosh introduction event, and Wozniak was seen kicking the dirt in the parking lot. Although Apple II products provided about 85% of Apple's sales in early 1985, the company's January 1985 annual meeting did not mention the Apple II division or its employees, a typical situation that frustrated Wozniak. Final departure from Apple workforce Even with the success he had helped to create at Apple, Wozniak believed that the company was hindering him from being who he wanted to be, and that it was "the bane of his existence". He enjoyed engineering, not management, and said that he missed "the fun of the early days". As other talented engineers joined the growing company, he no longer believed he was needed there, and by early 1985, Wozniak left Apple again, stating that the company had "been going in the wrong direction for the last five years". He then sold most of his stock. The Apple II platform financially carried the company well into the Macintosh era of the late 1980s; it was made semi-portable with the Apple IIc of 1984, was extended, with some input from Wozniak, by the 16-bit Apple IIGS of 1986, and was discontinued altogether when the Apple IIe was discontinued on November 15, 1993 (although the Apple IIe card, which allowed compatible Macintosh computers to run Apple II software and use certain Apple II peripherals, was produced until May 1995). Post-Apple career After his career at Apple, Wozniak founded CL 9 in 1985, which developed and brought the first programmable universal remote control to market in 1987, called the "CORE". Beyond engineering, Wozniak's second lifelong goal had always been to teach elementary school because of the important role teachers play in students' lives. Eventually, he did teach computer classes to children from the fifth through ninth grades, and teachers as well. Unuson continued to support this, funding additional teachers and equipment. In 2001, Wozniak founded Wheels of Zeus (WOZ) to create wireless GPS technology to "help everyday people find everyday things much more easily". In 2002, he joined the board of directors of Ripcord Networks, Inc., joining Apple alumni Ellen Hancock, Gil Amelio, Mike Connor, and Wheels of Zeus co-founder Alex Fielding in a new telecommunications venture. Later the same year he joined the board of directors of Danger, Inc., the maker of the Hip Top. In 2006, Wheels of Zeus was closed, and Wozniak founded Acquicor Technology, a holding company for acquiring technology companies and developing them, with Apple alumni Hancock and Amelio. From 2009 through 2014 he was chief scientist at Fusion-io. In 2014 he became chief scientist at Primary Data, which was founded by some former Fusion-io executives. Silicon Valley Comic Con (SVCC) is an annual pop culture and technology convention at the San Jose McEnery Convention Center in San Jose, California. The convention was co-founded by Wozniak and Rick White, with Trip Hunter as CEO. Wozniak announced the annual event in 2015 along with Marvel legend Stan Lee. In October 2017, Wozniak founded Woz U, an online educational technology service for independent students and employees. As of December 2018, Woz U was licensed as a school with the Arizona state board. Though permanently leaving Apple as an active employee in 1985, Wozniak chose to never remove himself from the official employee list, and continues to represent the company at events or in interviews. Today he receives a stipend from Apple for this role, estimated in 2006 to be per year. He is also an Apple shareholder. He maintained a friendly acquaintance with Steve Jobs until Jobs's death in October 2011. However, in 2006, Wozniak stated that he and Jobs were not as close as they used to be. In a 2013 interview, Wozniak said that the original Macintosh "failed" under Steve Jobs, and that it was not until Jobs left that it became a success. He called the Apple Lisa group the team that had kicked Jobs out, and that Jobs liked to call the Lisa group "idiots for making [the Lisa computer] too expensive". To compete with the Lisa, Jobs and his new team produced a cheaper computer, one that, according to Wozniak, was "weak", "lousy" and "still at a fairly high price". "He made it by cutting the RAM down, by forcing you to swap disks here and there", says Wozniak. He attributed the eventual success of the Macintosh to people like John Sculley "who worked to build a Macintosh market when the Apple II went away". At the end of 2020, Wozniak announced the launch of a new company helmed by him. Efforce is described as a marketplace for funding ecologically friendly projects. It used a WOZX cryptocurrency token for funding and blockchain to redistribute the profit to token holders and businesses engaged on the platform. In its first week trading, the WOZX cryptocurrency token increased 1,400%. In September 2021, it was reported that Wozniak was also starting a company alongside co-founder Alex Fielding named Privateer Space to address the problem of space debris. Patents Wozniak is listed as the sole inventor on the following Apple patents: US Patent No. 4,136,359: "Microcomputer for use with video display"—for which he was inducted into the National Inventors Hall of Fame. US Patent No. 4,210,959: "Controller for magnetic disc, recorder, or the like" US Patent No. 4,217,604: "Apparatus for digitally controlling PAL color display" US Patent No. 4,278,972: "Digitally-controlled color signal generation means for use with display" Philanthropy In 1990, Wozniak helped found the Electronic Frontier Foundation, providing some of the organization's initial funding and serving on its founding Board of Directors. He is the founding sponsor of the Tech Museum, Silicon Valley Ballet and Children's Discovery Museum of San Jose. Also since leaving Apple, Wozniak has provided all the money, and much onsite technical support, for the technology program in his local school district in Los Gatos. Un.U.Son. (Unite Us In Song), an organization Wozniak formed to organize the two US festivals, is now primarily tasked with supporting his educational and philanthropic projects. In 1986, Wozniak lent his name to the Stephen G. Wozniak Achievement Awards (popularly known as "Wozzie Awards"), which he presented to six Bay Area high school and college students for their innovative use of computers in the fields of business, art, and music. Wozniak is the subject of a student-made film production of his friend's (Joe Patane) nonprofit Dream Camp Foundation for high-level-need youth entitled Camp Woz: The Admirable Lunacy of Philanthropy. Honors and awards In 1979, Wozniak was awarded the ACM Grace Murray Hopper Award. In 1985, both he and Steve Jobs received the National Medal of Technology from US President Ronald Reagan. Later he donated funds to create the "Woz Lab" at the University of Colorado at Boulder. In 1998, he was named a Fellow of the Computer History Museum "for co-founding Apple Computer and inventing the Apple I personal computer." In September 2000, Wozniak was inducted into the National Inventors Hall of Fame, and in 2001 he was awarded the 7th Annual Heinz Award for Technology, the Economy and Employment. The American Humanist Association awarded him the Isaac Asimov Science Award in 2011. In 2004, Wozniak was given the 5th Annual Telluride Tech Festival Award of Technology. He was awarded the Global Award of the President of Armenia for Outstanding Contribution to Humanity Through IT in 2011. On February 17, 2014, in Los Angeles, Wozniak was awarded the 66th Hoover Medal from IEEE President & CEO J. Roberto de Marca. The award is presented to an engineer whose professional achievements and personal endeavors have advanced the well-being of humankind and is administered by a board representing five engineering organizations: The American Society of Mechanical Engineers; the American Society of Civil Engineers; the American Institute of Chemical Engineers; the American Institute of Mining, Metallurgical, and Petroleum Engineers; and Institute of Electrical and Electronics Engineers. The New York City Chapter of Young Presidents' Organization presented their 2014 Lifetime Achievement Award to Wozniak on October 16, 2014, at the American Museum of Natural History. In November 2014, Industry Week added Wozniak to the Manufacturing Hall of Fame. On June 19, 2015, Wozniak received the Legacy for Children Award from the Children's Discovery Museum of San Jose. The Legacy for Children Award honors an individual whose legacy has significantly benefited the learning and lives of children. The purpose of the Award is to focus Silicon Valley's attention on the needs of our children, encouraging us all to take responsibility for their well-being. Candidates are nominated by a committee of notable community members involved in children's education, health care, human and social services, and the arts. The city of San Jose named a street "Woz Way" in his honor. The street address of the Children's Discovery Museum of San Jose is 180 Woz Way. On June 20, 2015, The Cal Alumni Association (UC Berkeley's Alumni Association) presented Wozniak with the 2015 Alumnus of the Year Award. "We are honored to recognize Steve Wozniak with CAA's most esteemed award", said CAA President Cynthia So Schroeder '91. "His invaluable contributions to education and to UC Berkeley place him among Cal's most accomplished and respected alumni." In March 2016, High Point University announced that Wozniak will serve as their Innovator in Residence. Wozniak was High Point University's commencement speaker in 2013. Through this ongoing partnership, Wozniak will connect with High Point University students on a variety of topics and make campus-visits periodically. In March 2017, Wozniak was listed by UK-based company Richtopia at number 18 on its list of the 200 Most Influential Philanthropists and Social Entrepreneurs. Wozniak is the 2021 recipient of the IEEE Masaru Ibuka Consumer Electronics Award "for pioneering the design of consumer-friendly personal computers." Honorary degrees For his contributions to technology, Wozniak has been awarded a number of Honorary Doctor of Engineering degrees, which include the following: University of Colorado Boulder: 1989 North Carolina State University: 2004 Kettering University: 2005 Nova Southeastern University, Fort Lauderdale: 2005 ESPOL University in Ecuador: 2008 Michigan State University, in East Lansing 2011 Concordia University in Montreal, Canada: June 22, 2011 State Engineering University of Armenia: November 11, 2011 Santa Clara University: June 16, 2012 University Camilo José Cela in Madrid, Spain: November 8, 2013 In media Steve Wozniak has been mentioned, represented, or interviewed countless times in media from the founding of Apple to the present. Wired magazine described him as a person of "tolerant, ingenuous self-esteem" who interviews with "a nonstop, singsong voice". Documentaries Steve Jobs: The Man in the Machine (2015) Camp Woz: The Admirable Lunacy of Philanthropy a 2009 documentary Geeks On Board a 2007 documentary The Secret History of Hacking a 2001 documentary film featuring Wozniak and other phreakers and computer hackers. Triumph of the Nerds a 1996 PBS documentary series about the rise of the personal computer. Steve Wozniak's Formative Moment a March 15, 2016, original short feature film from Reddit Formative Moment Feature films 1999: Pirates of Silicon Valley a TNT film directed by Martyn Burke. Wozniak is portrayed by Joey Slotnick while Jobs is played by Noah Wyle. 2013: Jobs a film directed by Joshua Michael Stern. Wozniak is portrayed by Josh Gad, while Jobs is portrayed by Ashton Kutcher. 2015: Steve Jobs a feature film by Danny Boyle, with a screenplay written by Aaron Sorkin. Wozniak is portrayed by Seth Rogen, while Jobs is portrayed by Michael Fassbender. 2015: Steve Jobs vs. Bill Gates: The Competition to Control the Personal Computer, 1974–1999: Original film from the National Geographic Channel for the American Genius series. Television TechTV - The Screen Savers 2002-09-27 (Steve Wozniak and Kevin Mitnik a convicted hacker) Featuring an interview with Adrian Lamo https://www.youtube.com/watch?v=PMDI4-DNecw After seeing her stand-up performance in Saratoga, California, Wozniak began dating comedian Kathy Griffin. Together, they attended the 2007 Emmy Awards, and subsequently made many appearances on the fourth season of her show Kathy Griffin: My Life on the D-List. Wozniak is on the show as her date for the Producers Guild of America award show. However, on a June 19, 2008 appearance on The Howard Stern Show, Griffin confirmed that they were no longer dating and decided to remain friends. Wozniak portrays a parody of himself in the first episode of the television series Code Monkeys; he plays the owner of Gameavision before selling it to help fund his next enterprise. He later appears again in the 12th episode when he is in Las Vegas at the annual Video Game Convention and sees Dave and Jerry. He also appears in a parody of the "Get a Mac" ads featured in the final episode of Code Monkeys second season. Wozniak is also interviewed and featured in the documentary Hackers Wanted and on the BBC. Wozniak competed on Season 8 of Dancing with the Stars in 2009 where he danced with Karina Smirnoff. Though Wozniak and Smirnoff received 10 combined points from the three judges out of 30, the lowest score of the evening, he remained in the competition. He later posted on a social networking site that he believed that the vote count was not legitimate and suggested that the Dancing with the Stars judges had lied about the vote count to keep him on the show. After being briefed on the method of judging and vote counting, he retracted and apologized for his statements. Though suffering a pulled hamstring and a fracture in his foot, Wozniak continued to compete, but was eliminated from the competition on March 31, with a score of 12 out of 30 for an Argentine Tango. On September 30, 2010, he appeared as himself on The Big Bang Theory season 4 episode "The Cruciferous Vegetable Amplification". While dining in The Cheesecake Factory where Penny works, he is approached by Sheldon via telepresence on a Texai robot. Leonard tries to explain to Penny who Wozniak is, but she says she already knows him from Dancing with the Stars. On September 30, 2013, he appeared along with early Apple employees Daniel Kottke and Andy Hertzfeld on the television show John Wants	the Hip Top. In 2006, Wheels of Zeus was closed, and Wozniak founded Acquicor Technology, a holding company for acquiring technology companies and developing them, with Apple alumni Hancock and Amelio. From 2009 through 2014 he was chief scientist at Fusion-io. In 2014 he became chief scientist at Primary Data, which was founded by some former Fusion-io executives. Silicon Valley Comic Con (SVCC) is an annual pop culture and technology convention at the San Jose McEnery Convention Center in San Jose, California. The convention was co-founded by Wozniak and Rick White, with Trip Hunter as CEO. Wozniak announced the annual event in 2015 along with Marvel legend Stan Lee. In October 2017, Wozniak founded Woz U, an online educational technology service for independent students and employees. As of December 2018, Woz U was licensed as a school with the Arizona state board. Though permanently leaving Apple as an active employee in 1985, Wozniak chose to never remove himself from the official employee list, and continues to represent the company at events or in interviews. Today he receives a stipend from Apple for this role, estimated in 2006 to be per year. He is also an Apple shareholder. He maintained a friendly acquaintance with Steve Jobs until Jobs's death in October 2011. However, in 2006, Wozniak stated that he and Jobs were not as close as they used to be. In a 2013 interview, Wozniak said that the original Macintosh "failed" under Steve Jobs, and that it was not until Jobs left that it became a success. He called the Apple Lisa group the team that had kicked Jobs out, and that Jobs liked to call the Lisa group "idiots for making [the Lisa computer] too expensive". To compete with the Lisa, Jobs and his new team produced a cheaper computer, one that, according to Wozniak, was "weak", "lousy" and "still at a fairly high price". "He made it by cutting the RAM down, by forcing you to swap disks here and there", says Wozniak. He attributed the eventual success of the Macintosh to people like John Sculley "who worked to build a Macintosh market when the Apple II went away". At the end of 2020, Wozniak announced the launch of a new company helmed by him. Efforce is described as a marketplace for funding ecologically friendly projects. It used a WOZX cryptocurrency token for funding and blockchain to redistribute the profit to token holders and businesses engaged on the platform. In its first week trading, the WOZX cryptocurrency token increased 1,400%. In September 2021, it was reported that Wozniak was also starting a company alongside co-founder Alex Fielding named Privateer Space to address the problem of space debris. Patents Wozniak is listed as the sole inventor on the following Apple patents: US Patent No. 4,136,359: "Microcomputer for use with video display"—for which he was inducted into the National Inventors Hall of Fame. US Patent No. 4,210,959: "Controller for magnetic disc, recorder, or the like" US Patent No. 4,217,604: "Apparatus for digitally controlling PAL color display" US Patent No. 4,278,972: "Digitally-controlled color signal generation means for use with display" Philanthropy In 1990, Wozniak helped found the Electronic Frontier Foundation, providing some of the organization's initial funding and serving on its founding Board of Directors. He is the founding sponsor of the Tech Museum, Silicon Valley Ballet and Children's Discovery Museum of San Jose. Also since leaving Apple, Wozniak has provided all the money, and much onsite technical support, for the technology program in his local school district in Los Gatos. Un.U.Son. (Unite Us In Song), an organization Wozniak formed to organize the two US festivals, is now primarily tasked with supporting his educational and philanthropic projects. In 1986, Wozniak lent his name to the Stephen G. Wozniak Achievement Awards (popularly known as "Wozzie Awards"), which he presented to six Bay Area high school and college students for their innovative use of computers in the fields of business, art, and music. Wozniak is the subject of a student-made film production of his friend's (Joe Patane) nonprofit Dream Camp Foundation for high-level-need youth entitled Camp Woz: The Admirable Lunacy of Philanthropy. Honors and awards In 1979, Wozniak was awarded the ACM Grace Murray Hopper Award. In 1985, both he and Steve Jobs received the National Medal of Technology from US President Ronald Reagan. Later he donated funds to create the "Woz Lab" at the University of Colorado at Boulder. In 1998, he was named a Fellow of the Computer History Museum "for co-founding Apple Computer and inventing the Apple I personal computer." In September 2000, Wozniak was inducted into the National Inventors Hall of Fame, and in 2001 he was awarded the 7th Annual Heinz Award for Technology, the Economy and Employment. The American Humanist Association awarded him the Isaac Asimov Science Award in 2011. In 2004, Wozniak was given the 5th Annual Telluride Tech Festival Award of Technology. He was awarded the Global Award of the President of Armenia for Outstanding Contribution to Humanity Through IT in 2011. On February 17, 2014, in Los Angeles, Wozniak was awarded the 66th Hoover Medal from IEEE President & CEO J. Roberto de Marca. The award is presented to an engineer whose professional achievements and personal endeavors have advanced the well-being of humankind and is administered by a board representing five engineering organizations: The American Society of Mechanical Engineers; the American Society of Civil Engineers; the American Institute of Chemical Engineers; the American Institute of Mining, Metallurgical, and Petroleum Engineers; and Institute of Electrical and Electronics Engineers. The New York City Chapter of Young Presidents' Organization presented their 2014 Lifetime Achievement Award to Wozniak on October 16, 2014, at the American Museum of Natural History. In November 2014, Industry Week added Wozniak to the Manufacturing Hall of Fame. On June 19, 2015, Wozniak received the Legacy for Children Award from the Children's Discovery Museum of San Jose. The Legacy for Children Award honors an individual whose legacy has significantly benefited the learning and lives of children. The purpose of the Award is to focus Silicon Valley's attention on the needs of our children, encouraging us all to take responsibility for their well-being. Candidates are nominated by a committee of notable community members involved in children's education, health care, human and social services, and the arts. The city of San Jose named a street "Woz Way" in his honor. The street address of the Children's Discovery Museum of San Jose is 180 Woz Way. On June 20, 2015, The Cal Alumni Association (UC Berkeley's Alumni Association) presented Wozniak with the 2015 Alumnus of the Year Award. "We are honored to recognize Steve Wozniak with CAA's most esteemed award", said CAA President Cynthia So Schroeder '91. "His invaluable contributions to education and to UC Berkeley place him among Cal's most accomplished and respected alumni." In March 2016, High Point University announced that Wozniak will serve as their Innovator in Residence. Wozniak was High Point University's commencement speaker in 2013. Through this ongoing partnership, Wozniak will connect with High Point University students on a variety of topics and make campus-visits periodically. In March 2017, Wozniak was listed by UK-based company Richtopia at number 18 on its list of the 200 Most Influential Philanthropists and Social Entrepreneurs. Wozniak is the 2021 recipient of the IEEE Masaru Ibuka Consumer Electronics Award "for pioneering the design of consumer-friendly personal computers." Honorary degrees For his contributions to technology, Wozniak has been awarded a number of Honorary Doctor of Engineering degrees, which include the following: University of Colorado Boulder: 1989 North Carolina State University: 2004 Kettering University: 2005 Nova Southeastern University, Fort Lauderdale: 2005 ESPOL University in Ecuador: 2008 Michigan State University, in East Lansing 2011 Concordia University in Montreal, Canada: June 22, 2011 State Engineering University of Armenia: November 11, 2011 Santa Clara University: June 16, 2012 University Camilo José Cela in Madrid, Spain: November 8, 2013 In media Steve Wozniak has been mentioned, represented, or interviewed countless times in media from the founding of Apple to the present. Wired magazine described him as a person of "tolerant, ingenuous self-esteem" who interviews with "a nonstop, singsong voice". Documentaries Steve Jobs: The Man in the Machine (2015) Camp Woz: The Admirable Lunacy of Philanthropy a 2009 documentary Geeks On Board a 2007 documentary The Secret History of Hacking a 2001 documentary film featuring Wozniak and other phreakers and computer hackers. Triumph of the Nerds a 1996 PBS documentary series about the rise of the personal computer. Steve Wozniak's Formative Moment a March 15, 2016, original short feature film from Reddit Formative Moment Feature films 1999: Pirates of Silicon Valley a TNT film directed by Martyn Burke. Wozniak is portrayed by Joey Slotnick while Jobs is played by Noah Wyle. 2013: Jobs a film directed by Joshua Michael Stern. Wozniak is portrayed by Josh Gad, while Jobs is portrayed by Ashton Kutcher. 2015: Steve Jobs a feature film by Danny Boyle, with a screenplay written by Aaron Sorkin. Wozniak is portrayed by Seth Rogen, while Jobs is portrayed by Michael Fassbender. 2015: Steve Jobs vs. Bill Gates: The Competition to Control the Personal Computer, 1974–1999: Original film from the National Geographic Channel for the American Genius series. Television TechTV - The Screen Savers 2002-09-27 (Steve Wozniak and Kevin Mitnik a convicted hacker) Featuring an interview with Adrian Lamo https://www.youtube.com/watch?v=PMDI4-DNecw After seeing her stand-up performance in Saratoga, California, Wozniak began dating comedian Kathy Griffin. Together, they attended the 2007 Emmy Awards, and subsequently made many appearances on the fourth season of her show Kathy Griffin: My Life on the D-List. Wozniak is on the show as her date for the Producers Guild of America award show. However, on a June 19, 2008 appearance on The Howard Stern Show, Griffin confirmed that they were no longer dating and decided to remain friends. Wozniak portrays a parody of himself in the first episode of the television series Code Monkeys; he plays the owner of Gameavision before selling it to help fund his next enterprise. He later appears again in the 12th episode when he is in Las Vegas at the annual Video Game Convention and sees Dave and Jerry. He also appears in a parody of the "Get a Mac" ads featured in the final episode of Code Monkeys second season. Wozniak is also interviewed and featured in the documentary Hackers Wanted and on the BBC. Wozniak competed on Season 8 of Dancing with the Stars in 2009 where he danced with Karina Smirnoff. Though Wozniak and Smirnoff received 10 combined points from the three judges out of 30, the lowest score of the evening, he remained in the competition. He later posted on a social networking site that he believed that the vote count was not legitimate and suggested that the Dancing with the Stars judges had lied about the vote count to keep him on the show. After being briefed on the method of judging and vote counting, he retracted and apologized for his statements. Though suffering a pulled hamstring and a fracture in his foot, Wozniak continued to compete, but was eliminated from the competition on March 31, with a score of 12 out of 30 for an Argentine Tango. On September 30, 2010, he appeared as himself on The Big Bang Theory season 4 episode "The Cruciferous Vegetable Amplification". While dining in The Cheesecake Factory where Penny works, he is approached by Sheldon via telepresence on a Texai robot. Leonard tries to explain to Penny who Wozniak is, but she says she already knows him from Dancing with the Stars. On September 30, 2013, he appeared along with early Apple employees Daniel Kottke and Andy Hertzfeld on the television show John Wants Answers to discuss the movie Jobs. In April 2021, Wozniak became a panelist for the new TV series Unicorn Hunters, a business investment show from the makers of the series The Masked Singer. Views on artificial superintelligence In March 2015, Wozniak stated that while he had originally dismissed Ray Kurzweil's opinion that machine intelligence would outpace human intelligence within several decades, Wozniak had changed his mind: Wozniak stated that he had started to identify a contradictory sense of foreboding about artificial intelligence, while still supporting the advance of technology. By June 2015, Wozniak changed his mind again, stating that a superintelligence takeover would be good for humans: In 2016, Wozniak changed his mind again, stating that he no longer worried about the possibility of superintelligence emerging because he is skeptical that computers will be able to compete with human "intuition": "A computer could figure out a logical endpoint decision, but that's not the way intelligence works in humans". Wozniak added that if computers do become superintelligent, "they're going to be partners of humans over all other species just forever". Personal life Wozniak lives in Los Gatos, California. He applied for Australian citizenship in 2012, and has stated that he would like to live in Melbourne, Australia in the future. Wozniak has been referred to frequently by the nickname "Woz", or "The Woz"; he has also been called "The Wonderful Wizard of Woz" and "The Second Steve" (in regard to his early business partner and longtime friend, Steve Jobs). "WoZ" (short for "Wheels of Zeus") is the name of a company Wozniak founded in 2002; it closed in 2006. Wozniak describes his impetus for joining the Freemasons in 1979 as being able to spend more time with his then-wife, Alice Robertson, who belonged to the Order of the Eastern Star, associated with the Masons. Wozniak has said that he quickly rose to a third degree Freemason because, whatever he does, he tries to do well. He was initiated in 1979 at Charity Lodge No. 362 in Campbell, California, now part of Mt. Moriah Lodge No. 292 in Los Gatos. Today he is no longer involved: "I did become a Freemason and know what it's about but it doesn't really fit my tech/geek personality. Still, I can be polite to others from other walks of life. After our divorce was filed I never attended again but I did contribute enough for a lifetime membership." Wozniak was married to slalom canoe gold-medalist Candice Clark from June 1981 to 1987. They have three children together, the youngest being born after their divorce was finalized. After a high-profile relationship with actress Kathy Griffin, who described him on Tom Green's House Tonight in 2008 as "the biggest techno-nerd in the Universe", Wozniak married Janet Hill, his current spouse. On his religious views, Wozniak has called himself an "atheist or agnostic". He is a member of a Segway Polo team, the Silicon Valley Aftershocks, and is considered a "super fan" of the NHL ice hockey team San Jose Sharks. In 2006, he co-authored with Gina Smith his autobiography, iWoz: From Computer Geek
Italian Saxons were allowed to settle with their families in Austrasia. Gathering their families and belongings in Italy, they returned to Provence in two groups in 573. One group proceeded by way of Nice and another via Embrun, joining up at Avignon. They plundered the territory and were as a consequence stopped from crossing the Rhône by Mummolus. They were forced to pay compensation for what they had robbed before they could enter Austrasia. These people are known only by documents, and their settlement cannot be compared to the archeological artifacts and remains that attest to Saxon settlements in northern and western Gaul. Gaul A Saxon king named Eadwacer conquered Angers in 463 only to be dislodged by Childeric I and the Salian Franks, allies of the Roman Empire. It is possible that Saxon settlement of Great Britain began only in response to expanding Frankish control of the Channel coast. Some Saxons already lived along the Saxon shore of Gaul as Roman foederati. They can be traced in documents, but also in archeology and in toponymy. The Notitia Dignitatum mentions the Tribunus cohortis primae novae Armoricanae, Grannona in litore Saxonico. The location of Grannona is uncertain and was identified by the historians and toponymists at different places: mainly with the town known today as Granville (in Normandy) or nearby. The Notitia Dignitatum does not explain where these "Roman" soldiers came from. Some toponymists have proposed Graignes (Grania 1109–1113) as the location for Grannona/Grannonum. Although some scholars believe it could be the same element gran, that is recognised in Guernsey (Greneroi 11th century), it most likely derives from the Gaulish god Grannos. This location is closer to Bayeux, where Gregory of Tours evokes otherwise the Saxones Bajocassini (Bessin Saxons), which were ineffective against the Breton Waroch II in 579. A Saxon unit of laeti settled at Bayeuxthe Saxones Baiocassenses. These Saxons became subjects of Clovis I late in the fifth century. The Saxons of Bayeux comprised a standing army and were often called upon to serve alongside the local levy of their region in Merovingian military campaigns. In 589, the Saxons wore their hair in the Breton fashion at the orders of Fredegund and fought with them as allies against Guntram. Beginning in 626, the Saxons of the Bessin were used by Dagobert I for his campaigns against the Basques. One of their own, Aeghyna, was created a dux over the region of Vasconia. In 843 and 846 under king Charles the Bald, other official documents mention a pagus called Otlinga Saxonia in the Bessin region, but the meaning of Otlinga is unclear. Different Bessin toponyms were identified as typically Saxon, ex : Cottun (Coltun 1035–1037 ; Colas "town"). It is the only place name in Normandy that can be interpreted as a -tun one (English -ton; cf. Colton). In contrast to this one example in Normandy are numerous -thun villages in the north of France, in Boulonnais, for example Alincthun, Verlincthun, and Pelingthun, showing, with other toponyms, an important Saxon or Anglo-Saxon settlement. Comparing the concentration of -ham/-hem (Anglo-Saxon hām > home) toponyms in the Bessin and in the Boulonnais gives more examples of Saxon settlement. In the area known today as Normandy, the -ham cases of Bessin are uniquethey do not exist elsewhere. Other cases were considered, but there is no determining example. For example, Canehan (Kenehan 1030/Canaan 1030–1035) could be the biblical name Canaan or Airan (Heidram 9th century), the Germanic masculine name Hairammus. The Bessin examples are clear; for example, Ouistreham (Oistreham 1086), Étréham (Oesterham 1350 ?), Huppain (Hubbehain ; Hubbas "home"), and Surrain (Surrehain 11thcentury). Another significant example can be found in the Norman onomastics: the widespread surname Lecesne, with variant spellings: LeCesne, Lesène, Lecène, and Cesne. It comes from Gallo-Romance *SAXINU "the Saxon", which is saisne in Old French. These examples are not derived from more recent Anglo-Scandinavian toponyms, because in that case they would have been numerous in the Norman regions (pays deCaux, Basse-Seine, North-Cotentin) settled by Germanic peoples. That is not the case, nor does Bessin belong to the pagii, which were affected by an important wave of Anglo-Scandinavian immigration. In addition, archaeological finds add evidence to the documents and the results of toponymic research. Around the city of Caen and in the Bessin (Vierville-sur-Mer, Bénouville, Giverville, Hérouvillette), excavations have yielded numerous examples of Anglo-Saxon jewellery, design elements, settings, and weapons. All of these things were discovered in cemeteries in a context of the fifth, sixth and seventh centuries AD. The oldest and most spectacular Saxon site found in France to date is Vron, in Picardy. There, archaeologists excavated a large cemetery with tombs dating from the Roman Empire until the sixth century. Furniture and other grave goods, as well as the human remains, revealed a group of people buried in the fourth and fifth centuries AD. Physically different from the usual local inhabitants found before this period, they instead resembled the Germanic populations of the north. Starting around 375 AD the burials are located in the region known in Roman times as the Saxon Shores. 92% of these burials were inhumations, and sometimes included weapons of typical Germanic type. Starting from around 440 AD the burial ground displaced eastward. The burials were now arranged in rows and displayed a strong Anglo-Saxon influence until around 520 AD, when this influence subsided. Archaeological material, neighbouring toponymy, and historical accounts support the conclusion of settlement of Saxon foederati with their families on the shores of the English Channel. Further anthropological research by Joël Blondiaux shows these people were from Lower Saxony. Saxons in Britain Saxons, along with Angles, Frisians and Jutes, invaded or migrated to the island of Great Britain (Britannia) around the time of the collapse of the Western Roman Empire. Saxon raiders had been harassing the eastern and southern shores of Britannia for centuries before, prompting the construction of a string of coastal forts called the Litora Saxonica or Saxon Shore. Before the end of Roman rule in Britannia, many Saxons and other folk had been permitted to settle in these areas as farmers. According to tradition, the Saxons (and other tribes) first entered Britain en masse as part of an agreement to protect the Britons from the incursions of the Picts, Gaels and others. The story, as reported in such sources as the Historia Brittonum and Gildas, indicates that the British king Vortigern allowed the Germanic warlords, later named as Hengist and Horsa by Bede, to settle their people on the Isle of Thanet in exchange for their service as mercenaries. According to Bede, Hengist manipulated Vortigern into granting more land and allowing for more settlers to come in, paving the way for the Germanic settlement of Britain. Historians are divided about what followed: some argue that the takeover of southern Great Britain by the Anglo-Saxons was peaceful. The known account from a native Briton who lived in the mid-5th century AD, Gildas, described events as a forced takeover by armed attack: Gildas described how the Saxons were later slaughtered at the battle of Mons Badonicus 44 years before he wrote his history, and their conquest of Britain halted. The eighth-century English historian Bede tells how their advance resumed thereafter. He said this resulted in a swift overrunning of the entirety of South-Eastern Britain, and the foundation of the Anglo-Saxon kingdoms. Four separate Saxon realms emerged: East Saxons: created the Kingdom of Essex. Middle Saxons: created the province of Middlesex South Saxons: led by Aelle, created the Kingdom of Sussex West Saxons: created the Kingdom of Wessex During the period of the reigns from Egbert to Alfred the Great, the kings of Wessex emerged as Bretwalda, unifying the country. They eventually organised it as the kingdom of England in the face of Viking invasions. Later Saxons in Germany The Continental Saxons living in what was known as Old Saxony (c. 531–804) appear to have become consolidated by the end of the eighth century. After subjugation by the Emperor Charlemagne, a political entity called the Duchy of Saxony (804-1296) appeared, covering Westphalia, Eastphalia, Angria and Nordalbingia (Holstein, southern part of	cemeteries in a context of the fifth, sixth and seventh centuries AD. The oldest and most spectacular Saxon site found in France to date is Vron, in Picardy. There, archaeologists excavated a large cemetery with tombs dating from the Roman Empire until the sixth century. Furniture and other grave goods, as well as the human remains, revealed a group of people buried in the fourth and fifth centuries AD. Physically different from the usual local inhabitants found before this period, they instead resembled the Germanic populations of the north. Starting around 375 AD the burials are located in the region known in Roman times as the Saxon Shores. 92% of these burials were inhumations, and sometimes included weapons of typical Germanic type. Starting from around 440 AD the burial ground displaced eastward. The burials were now arranged in rows and displayed a strong Anglo-Saxon influence until around 520 AD, when this influence subsided. Archaeological material, neighbouring toponymy, and historical accounts support the conclusion of settlement of Saxon foederati with their families on the shores of the English Channel. Further anthropological research by Joël Blondiaux shows these people were from Lower Saxony. Saxons in Britain Saxons, along with Angles, Frisians and Jutes, invaded or migrated to the island of Great Britain (Britannia) around the time of the collapse of the Western Roman Empire. Saxon raiders had been harassing the eastern and southern shores of Britannia for centuries before, prompting the construction of a string of coastal forts called the Litora Saxonica or Saxon Shore. Before the end of Roman rule in Britannia, many Saxons and other folk had been permitted to settle in these areas as farmers. According to tradition, the Saxons (and other tribes) first entered Britain en masse as part of an agreement to protect the Britons from the incursions of the Picts, Gaels and others. The story, as reported in such sources as the Historia Brittonum and Gildas, indicates that the British king Vortigern allowed the Germanic warlords, later named as Hengist and Horsa by Bede, to settle their people on the Isle of Thanet in exchange for their service as mercenaries. According to Bede, Hengist manipulated Vortigern into granting more land and allowing for more settlers to come in, paving the way for the Germanic settlement of Britain. Historians are divided about what followed: some argue that the takeover of southern Great Britain by the Anglo-Saxons was peaceful. The known account from a native Briton who lived in the mid-5th century AD, Gildas, described events as a forced takeover by armed attack: Gildas described how the Saxons were later slaughtered at the battle of Mons Badonicus 44 years before he wrote his history, and their conquest of Britain halted. The eighth-century English historian Bede tells how their advance resumed thereafter. He said this resulted in a swift overrunning of the entirety of South-Eastern Britain, and the foundation of the Anglo-Saxon kingdoms. Four separate Saxon realms emerged: East Saxons: created the Kingdom of Essex. Middle Saxons: created the province of Middlesex South Saxons: led by Aelle, created the Kingdom of Sussex West Saxons: created the Kingdom of Wessex During the period of the reigns from Egbert to Alfred the Great, the kings of Wessex emerged as Bretwalda, unifying the country. They eventually organised it as the kingdom of England in the face of Viking invasions. Later Saxons in Germany The Continental Saxons living in what was known as Old Saxony (c. 531–804) appear to have become consolidated by the end of the eighth century. After subjugation by the Emperor Charlemagne, a political entity called the Duchy of Saxony (804-1296) appeared, covering Westphalia, Eastphalia, Angria and Nordalbingia (Holstein, southern part of modern-day Schleswig-Holstein state). The Saxons long resisted becoming Christians and being incorporated into the orbit of the Frankish kingdom. In 776 the Saxons promised to convert to Christianity and vow loyalty to the king, but, during Charlemagne's campaign in Hispania (778), the Saxons advanced to Deutz on the Rhine and plundered along the river. This was an oft-repeated pattern when Charlemagne was distracted by other matters. They were conquered by Charlemagne in a long series of annual campaigns, the Saxon Wars (772804). With defeat came enforced baptism and conversion as well as the union of the Saxons with the rest of the Germanic, Frankish empire. Their sacred tree or pillar, a symbol of Irminsul, was destroyed. Charlemagne also deported 10,000 Nordalbingian Saxons to Neustria and gave their now largely vacant lands in Wagria (approximately modern Plön and Ostholstein districts) to the loyal king of the Abotrites. Einhard, Charlemagne's biographer, says on the closing of this grand conflict: The war that had lasted so many years was at length ended by their acceding to the terms offered by the king; which were renunciation of their national religious customs and the worship of devils, acceptance of the sacraments of the Christian faith and religion, and union with the Franks to form one people. Under Carolingian rule, the Saxons were reduced to tributary status. There is evidence that the Saxons, as well as Slavic tributaries such as the Abodrites and the Wends, often provided troops to their Carolingian overlords. The dukes of Saxony became kings (Henry I, the Fowler, 919) and later the first emperors (Henry's son, Otto I, the Great) of Germany during the tenth century, but they lost this position in 1024. The duchy was divided in 1180 when Duke Henry the Lion refused to follow his cousin, Emperor Frederick Barbarossa, into war in Lombardy. During the High Middle Ages, under the Salian emperors and, later, under the Teutonic Knights, German settlers moved east of the Saale into the area of a western Slavic tribe, the Sorbs. The Sorbs were gradually Germanised. This region subsequently acquired the name Saxony through political circumstances, though it was initially called the March of Meissen. The rulers of Meissen acquired control of the Duchy of Saxony (only a remnant of the previous Duchy) in 1423; they eventually applied the name Saxony to the whole of their kingdom. Since then, this part of eastern Germany has been referred to as Saxony (), a source of some misunderstanding about the original homeland of the Saxons, with a central part in the present-day German state of Lower Saxony (). Culture Social structure Bede, a Northumbrian writing around the year 730, remarks that "the old (that is, the continental) Saxons have no king, but they are governed by several ealdormen (or satrapa) who, during war, cast lots for leadership but who, in time of peace, are equal in power." The regnum Saxonum was divided into three provinces – Westphalia, Eastphalia and Angria – which comprised about one hundred pagi or Gaue. Each Gau had its own satrap with enough military power to level whole villages that opposed him. In the mid-9th century, Nithard first described the social structure of the Saxons beneath their leaders. The caste structure was rigid; in the Saxon language the three castes, excluding slaves, were called the edhilingui (related to the term aetheling), frilingi and lazzi. These terms were subsequently Latinised as nobiles or nobiliores; ingenui, ingenuiles or liberi; and liberti, liti or serviles. According to very early traditions that are presumed to contain a good deal of historical truth, the edhilingui were the descendants of the Saxons who led the tribe out of Holstein and during the migrations of the sixth century. They were a conquering warrior elite. The frilingi represented the descendants of the amicii, auxiliarii and manumissi of that caste. The lazzi represented the descendants of the original inhabitants of the conquered territories, who were forced to make oaths of submission and pay tribute to the edhilingui. The Lex Saxonum regulated the Saxons' unusual society. Intermarriage between the castes was forbidden by the Lex, and wergilds were set based upon caste membership. The edhilingui were worth 1,440 solidi, or about 700 head of cattle, the highest wergild on the continent; the price of a bride was also very high. This was six times as much as that of the frilingi and eight times as much as the lazzi. The gulf between noble and ignoble was very large, but the difference between a freeman and an indentured labourer was small. According to the Vita Lebuini antiqua, an important source for early Saxon history, the Saxons held an annual council at Marklo (Westphalia) where they "confirmed their laws, gave judgment on outstanding cases, and determined by common counsel whether they would go to war or be in peace that year." All three castes participated in the general council; twelve representatives from each caste were sent from each Gau. In 782, Charlemagne abolished the system of Gaue and replaced it with the Grafschaftsverfassung, the system of counties typical of Francia. By prohibiting the Marklo councils, Charlemagne pushed the frilingi and lazzi out of political power. The old Saxon system of Abgabengrundherrschaft, lordship based on dues and taxes, was replaced by a form of feudalism based on service and labour, personal relationships and oaths. Religion Germanic Religion Saxon religious practices were closely related to their political practices. The annual councils of the entire tribe began with invocations of the gods. The procedure by which dukes were elected in wartime, by drawing lots, is presumed to have had religious significance, i.e. in giving trust to divine providenceit seemsto guide the random decision making. There were also sacred rituals and objects, such as the pillars called Irminsul; these were believed to connect heaven and earth, as with other examples of trees or ladders to heaven in numerous religions. Charlemagne had one such pillar chopped down in 772 close to the Eresburg stronghold. Early Saxon religious practices in Britain can be gleaned from place names and the Germanic calendar in use at that time. The Germanic gods Woden, Frigg, Tiw and Thunor, who are attested to in every Germanic tradition, were worshipped in Wessex, Sussex and Essex. They are the only ones directly attested to, though the names of the third and fourth months (March and April) of the Old English calendar bear the names Hrethmonath and Eosturmonath, meaning "month of Hretha" and "month of Ēostre." It is presumed that these are the names of two goddesses who were worshipped around that season. The Saxons offered cakes to their gods in February (Solmonath). There was a religious festival associated with the harvest, Halegmonath ("holy month" or "month of offerings", September). The Saxon calendar began on 25 December, and the months of December and January were called Yule (or Giuli). They contained a Modra niht or "night of the mothers", another religious festival of unknown content. The Saxon freemen and servile class remained faithful to their original beliefs long after their nominal conversion to Christianity. Nursing a hatred of the upper class, which, with Frankish assistance, had marginalised them from political power, the lower classes (the plebeium vulgus or cives) were a problem for Christian authorities as late as 836. The Translatio S.Liborii remarks on their obstinacy in pagan ritus et superstitio (usage and superstition). Christianity The conversion of the Saxons in England from their original Germanic religion to Christianity occurred in the early to late seventh century under the influence of the already converted Jutes of Kent. In the 630s, Birinus became the "apostle to the West Saxons" and converted Wessex, whose first Christian king was Cynegils. The West Saxons begin to emerge from obscurity only with their conversion to Christianity and keeping written records. The Gewisse, a West Saxon people, were especially resistant to Christianity; Birinus exercised more efforts against them and ultimately succeeded in conversion. In Wessex, a bishopric was founded at Dorchester. The South Saxons were first evangelised extensively under Anglian influence; Aethelwalh of Sussex was converted by Wulfhere, King of Mercia and allowed Wilfrid, Bishop of York, to evangelise his people beginning in 681. The chief South Saxon bishopric was that of Selsey. The East Saxons were more pagan than the southern or western Saxons; their territory had a superabundance of pagan sites. Their king, Saeberht, was converted early and a diocese was established at London. Its first bishop, Mellitus, was expelled by Saeberht's heirs. The conversion of the East Saxons was completed under Cedd in the 650s and 660s. The continental Saxons were evangelised largely by English missionaries in the late seventh and early eighth centuries. Around 695, two early English missionaries, Hewald the White and Hewald the Black, were martyred by the vicani, that is, villagers. Throughout the century that followed, villagers and other peasants proved to be the greatest opponents of Christianisation, while missionaries often received the support of the edhilingui and other noblemen. Saint Lebuin, an Englishman who between 745 and 770 preached to the Saxons, mainly in the eastern Netherlands, built a church and made many friends among the nobility. Some of them rallied to save him from an angry mob at the annual council at Marklo (near river Weser, Bremen). Social tensions arose between the Christianity-sympathetic noblemen and the pagan lower castes, who were staunchly faithful to their traditional religion. Under Charlemagne, the Saxon