title: Shamil Basayev

text: According to explosives experts, Basayev was most likely a victim of careless handling of the mine, but it is also not out of the question that the FSB could have been involved – as they would claim in the aftermath of the detonation. This could have happened if the shipment of weapons was seized and the smugglers detained; in forcing the captured smugglers to cooperate, an ordinary-looking anti-personnel mine rigged with an extra-sensitive fuse or radio-controlled detonator could have been inserted amongst the cargo. The device almost certainly would have caused suspicion when discovered in the shipment, which might explain why Basayev stopped to inspect it, at that point triggering the explosion. It was also not ruled out that an unknown FSB operative set off the blast by remote control, but in the event that this was the case, it almost assuredly would not have been a "targeted" killing, as identifying Basayev in the dark – even with the aid of night-vision goggles – would have been exceedingly difficult. Thus, experts have concluded that if it was a remote-controlled blast, it was intended to eliminate the weapons shipment and whoever the recipients were, rather than specifically Basayev.


title: Shamil Basayev

text: Basayev's upper torso was recovered at the epicenter of the blast, while smaller pieces of his remains were scattered over the distance of a mile. Included among the smaller pieces was Basayev's prosthetic lower right leg, which led FSB Director Nikolai Patrushev to confidently assert that Basayev was dead even before positive identification.


title: Shamil Basayev

text: Russian officials stated that the explosion was the result of a special targeted killing operation. According to the official version of Basayev's death, the FSB, following him with a drone, spotted his car approach a truck laden with explosives that the FSB had prepared, and by remote control triggered a detonator that the FSB had hidden in the explosives.


title: Shamil Basayev

text: Interfax, quoting Ingush Deputy Prime Minister Bashir Aushev, reported that the explosion was a result of a truck bomb detonated next to the convoy by Russian agents. According to a Russian edition of" Newsweek", Basayev's death was a result of an FSB operation, whose primary aim was to prevent a planned terrorist attack in the days before the G8 summit in St Petersburg. The Russian ambassador to the UN, Vitaly Churkin, said: "He is a notorious terrorist, and we have very clearly and publicly announced what is going to happen to notorious terrorists who commit heinous crimes of the type Mr. Basayev has been involved in." In February 2014, a Turkish court convicted a Chechen national Ruslan Papaskiri aka Temur Makhauri with the killings of several Chechen separatists on Turkish soil. The pro-Chechen separatist Imkander organization held a press conference claiming that Turkish investigators believed that Makhauri had prepared the explosives laden truck that killed Basayev.


title: Shamil Basayev

text: On 29 December 2006, forensic experts positively identified Basayev's remains. On 6 October 2007, Basayev was promoted to the rank of Generalissimo "post mortem" by Doku Umarov.


title: Shamil Basayev

text: Basayev had four wives, a Chechen woman who was killed in the 1990s, an Abkhaz woman he met while fighting against Georgia, and a Cossack he was said to have married on Valentine's Day, 2005. A fourth secret wife, Elina Ersenoyeva, was apparently forced to marry Basayev under threat of her two brothers' lives, and subsequently hid the identity of her husband from her friends and family. Following revelations about the marriage, Elina was abducted in November 2006, four months after the death of Basayev, allegedly by the Kadyrovtsy ("pro-Kremlin" Chechen forces). She has never been found.


title: Shamil Basayev

text: In May 1995, eleven members of Basayev's family were killed in a Russian air raid including his mother, his two children and a brother and sister. He also lost his home in the same attack, becoming the first Chechen who took revenge outside Chechen lands, in the Budyonnovsk hospital hostage crisis.


title: Shamil Basayev

text: His younger brother, Shirvani Basayev, who fought the Russians alongside him, is now living in exile in Turkey.


title: Shamil Basayev

text: Basayev wrote a book after the First Chechen War, "Book of a Mujahideen". According to the introduction, in March 2003 Basayev obtained a copy of "The Manual of the Warrior of Light" by Paulo Coelho. He wanted to draw benefits to the Mujahideen from this book and decided to "rewrite most of it, remove some excesses and strengthen all of it with verses (ayats), hadiths and stories from the lives of the disciples." Some sections are specifically about ambush tactics, etc.


title: Michael Dorn

text: Michael Dorn (born December 9, 1952) is an American actor best known for his role as the Klingon Worf in the "Star Trek" franchise. He has appeared more times as a regular cast member than any other "Star Trek" actor in the franchise's history, spanning five films and 277 television episodes.


title: Michael Dorn

text: Dorn was born in Luling, Texas, the son of Allie Lee (née Nauls) and Fentress Dorn Jr. He grew up in Pasadena, California, where he studied radio and television production at Pasadena City College. Following his graduation, he pursued a career in music as a performer with several different rock music bands, traveling to San Francisco and then back to Los Angeles.


title: Michael Dorn

text: Dorn first appeared on-screen in "Rocky", in an uncredited role as Apollo Creed's bodyguard. Two years later, he appeared as a guest star on a 1978 episode of the television show "W.E.B.". Impressed by his work, the show's producer introduced Dorn to an agent, through whom he met acting teacher Charles E. Conrad. Dorn studied with Conrad for six months, until he landed a regular role on the crime drama series "CHiPs".


title: Michael Dorn

text: Dorn's most notable role to date is that of the Klingon Starfleet officer Lieutenant (later Lt. Commander) Worf in "" and "". Dorn was the last of the main actors to be cast in "The Next Generation", and prepared for his audition by isolating himself from the other actors and remaining taciturn through his interview, mimicking the personality of the character. His character proved so popular amongst fans that Dorn was added to the cast of spin-off series "Deep Space Nine" in an effort to boost ratings.


title: Michael Dorn

text: He has appeared on-screen in more "Star Trek" episodes and movies as the same character than anyone else: he appeared in 175 episodes of "Star Trek: The Next Generation" (missing only the episodes "", "", and ""), 102 episodes of "Deep Space Nine" and five "Star Trek" movies, bringing his total to 282 appearances as Worf. He also appeared as Worf's ancestor, Colonel Worf, in the 1991 film "". He also directed the "" episodes "In the Cards", "" and "When It Rains...", and the "" episode "Two Days and Two Nights".


title: Michael Dorn

text: He was one of six actors to reprise his role, in voice over, for the "Star Trek: Captain's Chair" virtual reality game. In 2014, he participated in the fan-produced "Star Trek" episode "Fairest of Them All", giving his voice to the computer of the Mirror Universe Enterprise.


title: Michael Dorn

text: In 2012, Dorn announced a desire to return to his Klingon role in a television series tentatively titled "Star Trek: Captain Worf". He said: I had come up with the idea because I love [Worf] and I think he's a character that hasn't been fully developed and hasn't been fully realized. Once I started thinking about it, it became obvious to me that I wanted to at least put it out there, which I have, and the response has been pretty amazing. We've been contacted by different individuals–I can't say who and all that–about wanting to come on board and be part of this.


title: Michael Dorn

text: In April 2022, it was announced that he would indeed be reprising his role as Worf, in the third season of "", which is scheduled to air in 2023.


title: Michael Dorn

text: Dorn has appeared in a number of TV shows, films, and video games. He has been the spokesman for Neutrogena T-Gel Shampoo, and has appeared in a Dodge Dart car commercial. He appeared in a 2012 tongue-in-cheek television commercial for Chrysler as "Future Guy", a time traveler sent from the future to assist development of the 2013 Dodge Dart. He also plays the role of General Thain in the "Castlevania: Hymn of Blood" web series.


title: Michael Dorn

text: Following his "Star Trek" career, he had supporting roles in a number of independent feature films, including "Shadow Hours" (2000), "Lessons for an Assassin" (2001), and "The Santa Clause" trilogy, in which he appeared in a minor role as the Sandman. Dorn reprised his role as Worf for cameo appearances on "Webster" and "Family Guy", the latter with several of his fellow "Next Generation" castmates. He had a recurring role on the television series "Castle", playing the therapist of NYPD police detective Kate Beckett.


title: Michael Dorn

text: A member of the Aircraft Owners and Pilots Association, Dorn is an accomplished pilot. He has flown with the Blue Angels as well as the Thunderbirds. He has owned several jet aircraft, including a Lockheed T-33 Shooting Star, which he jokingly refers to as his "starship", a North American F-86 Sabre, and currently owns a North American Sabreliner. Dorn also serves on several aviation organizations, one of which is the Air Force Aviation Heritage Foundation, where he is on the advisory board. He has done interviews for the "Private Jets" episode of "Modern Marvels" on The History Channel.


title: Michael Dorn

text: Dorn stated in a 2010 interview that he had been diagnosed with an "early early" stage of prostate cancer, which led him to become a vegan.


title: Mazda6

text: The Mazda6 (known as the Mazda Atenza in Japan and China, derived from the Italian "attenzione") is a mid-size sedan produced by Mazda since 2002, replacing the long-produced Capella/626.


title: Mazda6

text: The Mazda6 was marketed as the first example of the company's "Stylish, Insightful and Spirited" design philosophy, followed by the Mazda2 in December 2002, the RX-8 in August 2003, the Mazda3 in January 2004, the Mazda5 in the summer of 2005, the MX-5 in October 2005, and the CX-7 in November 2006. The 2003 Mazda6 is essentially the seventh-generation Mazda 626, part of the 'G' model code family.


title: Mazda6

text: The first-generation Mazda6 was launched in Japan as the Mazda Atenza in May 2002. The model lineup consisted of a four-door sedan, a four-door hatchback and a five-door wagon, marketed in North America as the "Sport Sedan", "5-Door" and "Sport Wagon", respectively. In Australia, the lineup was first available in Limited trim, as a sedan; in Classic trim as sedan, hatch or wagon and in Luxury trim as a sedan and liftback — and Luxury Sports trim, as a liftback. In New Zealand, the lineup consisted of 2.0L GLX (sedan only), 2.3L GSX (sedan, liftback, and wagon), and 2.3L Limited (sedan and liftback).


title: Mazda6

text: The first generation was marketed as a 2003 model in the United States and as a 2004 model in Canada. In Europe, the luxury sports model was available as a direct injection turbodiesel ("DITD") estate up until 2007. As of 2008, the European Mazda catalog listed only the "Sport" version of the turbodiesel estate, while the "Luxury Sport" version had been dropped.


title: Mazda6

text: Drivetrain combinations included the Mazda MZR engine in configurations of 1.8 L (L8-DE), 2.0 L (LF-VE) and 2.3 L (L3-VE), initially with a five-speed manual or four-speed automatic transmission (with a sequential-automatic option, dubbed the "Four-Speed Sport AT"). In the US domestic market a 3.0 L Duratec 30 V6 engine was also available with a five-speed manual or five-speed automatic (with a sequential-automatic option, dubbed the "5-Speed Sport AT"). European and Australian versions also feature a four-cylinder turbodiesel that comes with a six-speed manual transmission and produces significantly more torque than the V6, with much improved fuel economy.


title: Mazda6

text: In North America, the 5-speed automatic optional on the V6 models were replaced by an Aisin 6-speed automatic for the 2005 model year. The four-cylinder model received a Jatco five-speed automatic in the following year. Power was directed to the front wheels in most markets, although full-time all-wheel-drive models were available in Japan, Europe, and Australia. Not all configurations were available in all areas – for example, the Mazda 6 as released in Australia was available in 2.3L four-cylinder guise only, when the 626 it replaced had been available with a choice of four- or six-cylinder engines. The MZI V6 engine was only fitted to vehicles manufactured at Mazda's Flat Rock Assembly Plant and destined for the U.S. and Canadian domestic markets.


title: Mazda6

text: Mazda's Hofu Plant in Yamaguchi Prefecture produced the Mazda6 for international markets from February 2002 to August 2007. In North America, Mazda6 production was handled at the AutoAlliance International plant in Flat Rock, Michigan. The first Mazda6 rolled off the AAI assembly line on October 1, 2002, one month after 626 production ended. There are also satellite plants building Mazda6 models in China and Thailand for local markets.


title: Mazda6

text: In September 2005, the Mazda6 received a facelift which introduced 5-speed auto and 6-speed manual transmissions, standard 16- or 17-inch alloy wheels, and minor bodywork upgrades.


title: Mazda6

text: In China, the Mazda6 was introduced by FAW Mazda in 2003. Despite the release of its successors, the first generation car, known locally as the "Maliu" (马六, "Horse 6"), continues to be manufactured at FAW's Changchun plant, having sold over 770,000 units as of 2014. This model is also used as the base for the FAW Benteng, also known as Besturn B70 or Hongqi C301.


title: Mazda6

text: The 2006 Mazdaspeed6 (known as "Mazdaspeed Atenza" in Japan and "Mazda6 MPS" in Europe, South Africa and Australia) is a high-performance version of the first generation Mazda6. Its mission statement was written with the help of Peter Birtwhistle, chief of Mazda's advanced design studio in Germany at the time. It was initially unveiled as a concept at the 2002 Paris Motor Show. It features a turbocharged version of the 2.3 L MZR inline-four which produces 272 PS (200 kW) (European version is detuned to 260 PS (191 kW); the North American version, at 274 hp (204 kW), revised to for 2007). All models have of torque. The 2.3 L DISI turbocharged engine features direct fuel injection and conforms to the new Euro 5 emissions standards. All markets received a revised front fascia with a raised hood, a 6-speed manual transmission, and all-wheel drive. The all-wheel-drive system uses Mazda's "Active Torque Split" computer-based control, which can route between a 100/0 to 50/50 front/rear torque split depending on driving conditions. Power is sent to the rear wheels through a limited-slip differential.


title: Mazda6

text: Originally scheduled to be launched in June 2005, the Mazdaspeed Atenza was delayed until November. In North America, the Mazdaspeed6 comes in two trim levels; the "Sport" trim with cloth interior and standard key entry and ignition; and the "Grand Touring" trim with leather interior, keyless entry/ignition, and optional DVD navigation. Automatic climate control is standard, as is a 200 W Bose stereo system featuring seven speakers and a 9-inch subwoofer in addition to an in-dash six-disc CD changer. A sunroof with moonroof feature is optional on the Grand Touring trim.


title: Mazda6

text: The Mazdaspeed6 was released to generally positive reviews, and was noted for impressive power and handling.


title: Mazda6

text: The second-generation Mazda6 made its premiere at the 2007 Frankfurt Motor Show in September. It is based on the modified first-generation Mazda6 chassis which Ford also utilized as their CD3 platform. Mazda continued to provide three body styles, including 4-door saloon (sedan), 5-door hatchback and wagon. A number of journalists have already praised its electrically assisted steering for being considerably improved compared to the previous generation, providing more feedback to the driver. The hatchback model even has a trunk space which beats the larger rival Ford Mondeo and Opel/Vauxhall Insignia (hatchback) by 200 liters with rear seats folded down.


title: Mazda6

text: The North American version was redesigned for the 2009 model year, with the wagon and hatchback versions being dropped there. It is a widened and lengthened version of the model sold elsewhere, with larger engines. Reviewers have noted its coupe-like roofline and sportier style. North American engine choices include a new 2.5-liter 4-cylinder and North American versions get the 3.7-liter V6 which is also available in the Mazda CX-9. "Motor Trend" recorded a 0–60 mph acceleration time of 6.1 seconds for the Mazda 6 V6.


title: Mazda6

text: In America, only a sedan model was available (In the Middle East, USDM Mazda6 known as Mazda6 Ultra is sold alongside the JDM Mazda6). A Mazdaspeed6 variant was not offered. Despite the North American version's increase in dimensions, Mazda maintains that the 6 retains the overall driving experience is still sportier than rivaling Honda Accords, Toyota Camrys, or Chevrolet Malibus. Early reviews have been favorable.


title: Mazda6

text: On March 3, 2011, around 50,000 Mazda6 vehicles from the 2009–10 model years were recalled in the United States, with another 15,000 in Canada, Mexico and Puerto Rico after it was found that Yellow Sac Spiders were building nests in the fuel line of the vehicles. The Mazda6 has two pipes coming from its gas tank, an extremely rare configuration. The amount of gasoline vapor in the fuel line is just strong enough to draw the spider in but not strong enough to kill it. On April 5, 2014, Mazda reissued the same recall for spiders against all 2010–2013 Mazda6 vehicles with 2.5 liter engines.


title: Mazda6

text: Production for North American market would be transferred to Hofu, Japan, when Mazda ceased production at the Flat Rock Assembly Plant.


title: Mazda6

text: The last Mazda6 rolled off the line at Mazda's Flat Rock Assembly Plant on Friday, August 24, 2012, with Mazda discontinuing production on American soil, effectively ending the 20 year joint-venture between Mazda and Ford. Mazda moved production of the Mazda6 back to the Hofu factory in Japan.


title: Mazda6

text: In China, over 680,000 Mazdas, including Mazda6 made between September 2008 and January 2016, were recalled due to faulty airbags. An earlier recall involved 280,000 Mazda6 models made between 2003 and 2008 for a similar issue.


title: Mazda6

text: In 2007, Mazda won its first manufacturers championship in the Touring Car class. In 2009, they finished 2nd in the manufacturer's championship with 65 points, behind Acura.


title: Mazda6

text: The Mazda6 has also been used in the KONI Challenge Series Sport Touring class. It was last used in 2008 by the Baglieracing team with Dennis Baglier, Chris Gleason, and Marty Luffy as drivers.


title: Mazda6

text: The third generation Mazda6 sedan was unveiled during Moscow International Automobile Salon on 29 August 2012, and the station wagon version followed during the 2012 Paris Motor Show in the following month. In this generation, there are only 4-door sedan and 5-door station wagon versions available. The design was previewed by both the Takeri concept, unveiled at the 2011 Tokyo Motor Show, and the Shinari concept from 2010.


title: Mazda6

text: Its design has been extremely well-received, and was a finalist in the "2013 World Design of the Year".


title: Mazda6

text: The Mazda6 was second place in the 2003 European Car of the Year awards and made "Car and Driver" magazine's Ten Best list for 2003. The "Sport Wagon" won the Canadian Car of the Year "Best New Station Wagon" award, while the "Sport" sedan won the Canadian Car of the Year "Best New Family Car" award for 2005. The Atenza Wagon also won What Car?'s "Best Estate" award in 2004. Also the Mazda6 won the 2003 Semperit Irish Car of the Year.


title: Mazda6

text: The Mazda6 won the 'Best Mid-size Car (over $28,000)' title in Australia's Best Cars in 2002 and 2003. It came second in 2004, behind the Subaru Liberty, and fifth in 2005 (the Honda Accord Euro was first in 2005). Wheels magazine also awarded the Mazda6 winner of its Active Safety Program in July 2005. In December 2007 the Mazda6 won the Carsales Peoples Choice award for its class in Australia.


title: Mazda6

text: The Mazda6 was praised for its edgy handsome design, communicative steering, and tight suspension. However, as it was designed as a world car in order to fit the needs of Europe and Japan, it was smaller than its North American contemporaries in the midsize segment, being criticized for its reduced passenger space. Its acceleration, particularly the V6 engine models, lagged behind that of its rivals as well.


title: Mazda6

text: The hatchback's liftback/notchback styling was considered a clever design to disguise it as a four-door saloon, as North Americans generally considered trunks more elegant than hatches. The estate had an early demise, but the hatchback was somewhat successful in Canada, especially in Québec, though it would not have a 2009 refresh, as both models were unpopular in the US.


title: This Is England

text: This Is England is a 2006 British drama film written and directed by Shane Meadows. The story centres on young skinheads in England in 1983. The film illustrates how their subculture, which has its roots in 1960s West Indies culture, especially ska, soul, and reggae music, became influenced by the far-right, especially white nationalists and white supremacists, which led to divisions within the skinhead scene. The film's title is a direct reference to a scene where the character Combo explains his nationalist views using the phrase "this is England" during his speech.


title: This Is England

text: In July 1983, Shaun is a troubled 12-year-old boy who lives with his widowed mother and is frequently antagonised in school and around town. On the last day of the school year, Shaun gets into a fight at school with a boy named Harvey after the latter makes an offensive joke about his father, who was killed in the Falklands War. On his way home, Shaun comes across a gang of young skinheads led by Woody, who feels sympathy for Shaun and invites him to join the group. He introduces Shaun to Milky, the only black skinhead of the gang; Pukey, Kes, and the overweight, dim-witted Gadget. Despite some initial hostilities between Shaun and Gadget, the gang accepts Shaun as a member. Shaun bonds closely with Richard "Woody" Woodford, viewing him a big brother figure, and his girlfriend Lorraine "Lol" Jenkins, who takes a motherly role towards him. Shaun also develops a romantic relationship with Michelle, also known as Smell, an older girl who dresses in a new wave, new romantic style.


title: This Is England

text: During a party one night, the group is ambushed by a bald, tattooed, moustachioed machete-wielding man, who is then attacked by Andrew "Combo" Gascoigne, a first-wave skinhead. With the attack revealed to be a prank, Woody announces that Combo had just finished a three-year prison sentence, and Combo introduces the man as his associate Banjo. Combo, a charismatic but unstable man with sociopathic tendencies, begins to express English nationalist and racist views, alienating Woody, Lol, Kes, and Milky. Later on, he attempts to enforce his leadership over the other skinheads. When Combo mentions the Falklands War as part of a speech, an upset Shaun reveals to the gang that his father died in that conflict, which Combo then uses to manipulate the boy into joining his side. Consequently, the gang splits, with young Shaun, the belligerent Pukey, and Gadget, who feels bullied by Woody for his weight, choosing Combo over Woody's apolitical gang.


title: This Is England

text: Shaun finds a hero-figure in Combo, who in turn is impressed by, and identifies with, Shaun. Combo's group attend a National Front meeting. On the drive home Pukey expresses doubt over their racist and nationalistic politics. Combo furiously stops the car and yanks Pukey out, lightly assaulting him in ridicule in front of the others, abandoning him in isolated countryside by the roadside.


title: This Is England

text: The gang deface walls, intimidate local children and spray racist slogans on Asian shopkeeper Mr Sandhu's walls, whilst Shaun, previously banned from the shop, launches a bigoted verbal assault on Sandhu with demands for drink and cigarettes. Combo viciously threatens Sandhu with a machete and the gang steal goods for a birthday party under Combo's instructions.


title: This Is England

text: Combo becomes upset after Lol, Woody's girlfriend, rejects him when he admits that he has loved her since they had sex years before. To console himself, Combo buys cannabis from Milky, and invites him to a party. While intoxicated, Combo and Milky bond, but Combo becomes increasingly bitter and envious, all wrapped up in a racist viewpoint, when Milky shares details of his many relatives, comfortable family life and happy upbringing, everything that Combo lacked. An enraged Combo enters a frenzied state and brutally beats Milky unconscious, while Banjo holds down Shaun, and Meggy watches on in horror. An angry Combo violently throws Shaun out of his flat after Shaun verbally defends Milky, then slams the door hard. When Banjo attempts to hit Milky as well, Combo violently beats him and evicts him and Meggy from the flat. Horrified at the realisation of what he has done, a remorseful Combo weeps over Milky. Shaun and Combo later take Milky to a nearby hospital.


title: This Is England

text: The film cuts forward to Shaun, who is in his bedroom looking at a picture of his late father. He is contemplating the incident and brooding about what happened, with his mother Cynthia assuring him that Milky will be all right. Shaun is then shown walking near the beach and throwing his St George's Flag, a gift from Combo, into the sea.


title: This Is England

text: Much of the film was shot in residential areas of Nottingham, including St Ann's, Lenton, and The Meadows, with one section featuring abandoned houses at RAF Newton, a former airbase close to Bingham, Nottinghamshire. The opening fight was filmed at Wilsthorpe Business and Enterprise College, a secondary school in Long Eaton, Derbyshire, close to the Nottinghamshire/Derbyshire boundary. Additional scenes such as 'the docks' were filmed in Turgoose's home town of Grimsby. Turgoose was 13 at the time of filming. He had never acted before, was banned from his school play for bad behaviour, and demanded £5 to turn up for the film's auditions. The film was dedicated to Turgoose's mother, Sharon, who died of cancer on 29 December 2005; while she never saw the film, she saw a short preview. The cast attended her funeral.


title: This Is England

text: The film is set in an unidentified town in the Midlands. Although much of the film was shot on location in Nottingham, a number of scenes portray the town's docks, which precludes this inland city being the setting for the action. Similarly, the dialects of the main characters are drawn from a wide geographical area.


title: This Is England

text: On the review aggregator website Rotten Tomatoes, the film has an approval rating of 93% based on 94 reviews, with an average rating of 7.70/10. The website's critical consensus reads, "A moving coming-of-age tale that captures the despair among England's working-class youth in the 1980s". Metacritic gives the film a weighted average score of 86 out of 100 based on 23 reviews, indicating "universal acclaim". This made it the tenth best reviewed film of the year.


title: This Is England

text: The film appeared on several US critics' top ten lists of 2007; it was third on the list by "Newsweek"<nowiki>'</nowiki>s David Ansen, seventh on the list by "The Oregonian"<nowiki>'</nowiki>s Marc Mohan, and ninth on the list by "Los Angeles Times" Kevin Crust.


title: This Is England

text: In Britain, director Gillies Mackinnon rated the film the best of the year and David M. Thompson, critic and film-maker, rated it third. The film was ranked fourteenth in "The Guardian"s list of 2007's Best Films and fifteenth in "Empire's" Movies of the Year.


title: This Is England

text: The film won the Alexander Korda Award for Best British Film at the 2007 British Academy Film Awards.


title: This Is England

text: At the 2006 British Independent Film Awards, the film won the award for Best Film and Thomas Turgoose won the award for Most Promising Newcomer.


title: This Is England

text: In 2010, a spin-off series set three years after the film, "This Is England '86", was shown on Channel 4. A sequel to the series set two and a half years later, "This Is England '88", was broadcast in December 2011. A third installment, "This Is England '90", was shown in September 2015.


title: YAML

text: YAML ( and ) ("see ") is a human-readable data-serialization language. It is commonly used for configuration files and in applications where data is being stored or transmitted. YAML targets many of the same communications applications as Extensible Markup Language (XML) but has a minimal syntax which intentionally differs from Standard Generalized Markup Language (SGML). It uses both Python-style indentation to indicate nesting, and a more compact format that uses for lists and for maps thus JSON files are valid YAML 1.2.


title: YAML

text: Custom data types are allowed, but YAML natively encodes scalars (such as strings, integers, and floats), lists, and associative arrays (also known as maps, dictionaries or hashes). These data types are based on the Perl programming language, though all commonly used high-level programming languages share very similar concepts. The colon-centered syntax, used for expressing key-value pairs, is inspired by electronic mail headers as defined in , and the document separator is borrowed from MIME (). Escape sequences are reused from C, and whitespace wrapping for multi-line strings is inspired by HTML. Lists and hashes can contain nested lists and hashes, forming a tree structure; arbitrary graphs can be represented using YAML aliases (similar to XML in SOAP). YAML is intended to be read and written in streams, a feature inspired by SAX.


title: YAML

text: Support for reading and writing YAML is available for many programming languages. Some source-code editors such as Vim, Emacs, and various integrated development environments have features that make editing YAML easier, such as folding up nested structures or automatically highlighting syntax errors.


title: YAML

text: YAML (, rhymes with "camel") was first proposed by Clark Evans in 2001, who designed it together with Ingy döt Net and Oren Ben-Kiki. Originally YAML was said to mean "Yet Another Markup Language", because it was released in an era that saw a proliferation of markup languages for presentation and connectivity (HTML, XML, SGML, etc). Its initial name was intended as a tongue-in-cheek reference to the technology landscape, referencing its purpose as a markup language with the yet another construct, but it was then repurposed as "YAML Ain't Markup Language", a recursive acronym, to distinguish its purpose as data-oriented, rather than document markup.


title: YAML

text: A cheat sheet and full specification are available at the official site. The following is a synopsis of the basic elements.


title: YAML

text: YAML accepts the entire Unicode character set, except for some control characters, and may be encoded in any one of UTF-8, UTF-16 or UTF-32. (Though UTF-32 is not mandatory, it is required for a parser to have JSON compatibility.)


title: YAML

text: Keys are separated from values by a colon+space. Indented blocks, common in YAML data files, use indentation and new lines to separate the key/value pairs. Inline Blocks, common in YAML data streams, use comma+space to separate the key/value pairs between braces.


title: YAML

text: Strings do not require quotation marks. There are two ways to write multi-line strings, one preserving newlines (using the codice_1 character) and one that folds the newlines (using the character), both followed by a newline character.


title: YAML

text: By default, the leading indentation (of the first line) and trailing whitespace are stripped, though other behavior can be explicitly specified.


title: YAML

text: Objects and lists are important components in yaml and can be mixed. The first example is a list of key-value objects, all people from the Smith family. The second lists them by gender; it is a key-value object containing two lists.


title: YAML

text: Two features that distinguish YAML from the capabilities of other data-serialization languages are structures and data typing.


title: YAML

text: YAML structures enable storage of multiple documents within a single file, usage of references for repeated nodes, and usage of arbitrary nodes as keys.


title: YAML

text: For clarity, compactness, and avoiding data entry errors, YAML provides node anchors (using ) and references (using ). References to the anchor work for all data types (see the ship-to reference in the example below).


title: YAML

text: Below is an example of a queue in an instrument sequencer in which two steps are reused repeatedly without being fully described each time.


title: YAML

text: Explicit data typing is seldom seen in the majority of YAML documents since YAML autodetects simple types. Data types can be divided into three categories: core, defined, and user-defined. Core are ones expected to exist in any parser (e.g. floats, ints, strings, lists, maps, ...). Many more advanced data types, such as binary data, are defined in the YAML specification but not supported in all implementations. Finally YAML defines a way to extend the data type definitions locally to accommodate user-defined classes, structures or primitives (e.g. quad-precision floats).


title: YAML

text: YAML autodetects the datatype of the entity, but sometimes one wants to cast the datatype explicitly. The most common situation is where a single-word string that looks like a number, boolean or tag requires disambiguation by surrounding it with quotes or using an explicit datatype tag.


title: YAML

text: Not every implementation of YAML has every specification-defined data type. These built-in types use a double-exclamation sigil prefix (). Particularly interesting ones not shown here are sets, ordered maps, timestamps, and hexadecimal. Here's an example of base64-encoded binary data.


title: YAML

text: Many implementations of YAML can support user-defined data types for object serialization. Local data types are not universal data types but are defined in the application using the YAML parser library. Local data types use a single exclamation mark ().


title: YAML

text: Notice that strings do not require enclosure in quotation marks. The specific number of spaces in the indentation is unimportant as long as parallel elements have the same left justification and the hierarchically nested elements are indented further. This sample document defines an associative array with 7 top level keys: one of the keys, "items", contains a 2-element list, each element of which is itself an associative array with differing keys. Relational data and redundancy removal are displayed: the "ship-to" associative array content is copied from the "bill-to" associative array's content as indicated by the anchor () and reference () labels. Optional blank lines can be added for readability. Multiple documents can exist in a single file/stream and are separated by . An optional can be used at the end of a file (useful for signaling an end in streamed communications without closing the pipe).


title: YAML

text: Because YAML primarily relies on outline indentation for structure, it is especially resistant to delimiter collision. YAML's insensitivity to quotation marks and braces in scalar values means one may embed XML, JSON or even YAML documents inside a YAML document by simply indenting it in a block literal (using codice_1 or ):


title: YAML

text: YAML may be placed in JSON by quoting and escaping all interior quotation marks. YAML may be placed in XML by escaping reserved characters (, , , , ) and converting whitespace, or by placing it in a CDATA section.


title: YAML

text: Unlike JSON, which can only represent data in a hierarchical model with each child node having a single parent, YAML also offers a simple relational scheme that allows repeats of identical data to be referenced from two or more points in the tree rather than entered redundantly at those points. This is similar to the facility IDREF built into XML. The YAML parser then expands these references into the fully populated data structures they imply when read in, so whatever program is using the parser does not have to be aware of a relational encoding model, unlike XML processors, which do not expand references. This expansion can enhance readability while reducing data entry errors in configuration files or processing protocols where many parameters remain the same in a sequential series of records while only a few vary. An example being that "ship-to" and "bill-to" records in an invoice are nearly always the same data.


title: YAML

text: YAML is line-oriented and thus it is often simple to convert the unstructured output of existing programs into YAML format while having them retain much of the look of the original document. Because there are no closing tags, braces, or quotation marks to balance, it is generally easy to generate well-formed YAML directly from distributed print statements within unsophisticated programs. Likewise, the whitespace delimiters facilitate quick-and-dirty filtering of YAML files using the line-oriented commands in grep, AWK, Perl, Ruby, and Python.


title: YAML

text: In particular, unlike markup languages, chunks of consecutive YAML lines tend to be well-formed YAML documents themselves. This makes it very easy to write parsers that do not have to process a document in its entirety (e.g. balancing opening and closing tags and navigating quoted and escaped characters) before they begin extracting specific records within. This property is particularly expedient when iterating in a single, stateless pass, over records in a file whose entire data structure is too large to hold in memory, or for which reconstituting the entire structure to extract one item would be prohibitively expensive.


title: YAML

text: Counterintuitively, although its indented delimiting might seem to complicate deeply nested hierarchies, YAML handles indents as small as a single space, and this may achieve better compression than markup languages. Additionally, extremely deep indentation can be avoided entirely by either: 1) reverting to "inline style" (i.e. JSON-like format) without the indentation; or 2) using relational anchors to unwind the hierarchy to a flat form that the YAML parser will transparently reconstitute into the full data structure.


title: YAML

text: YAML is purely a data-representation language and thus has no executable commands. While validation and safe parsing is inherently possible in any data language, implementation is such a notorious pitfall that YAML's lack of an associated command language may be a relative security benefit.


title: YAML

text: However, YAML allows language-specific tags so that arbitrary local objects can be created by a parser that supports those tags. Any YAML parser that allows sophisticated object instantiation to be executed opens the potential for an injection attack. Perl parsers that allow loading of objects of arbitrary classes create so-called "blessed" values. Using these values may trigger unexpected behavior, e.g. if the class uses overloaded operators. This may lead to execution of arbitrary Perl code.


title: YAML

text: Note that the ability to construct an arbitrary Python object may be dangerous if you receive a YAML document from an untrusted source such as the Internet. The function limits this ability to simple Python objects like integers or lists. [...]


title: YAML

text: PyYAML allows you to construct a Python object of any type. Even instances of Python classes can be constructed using the tag.


title: YAML

text: The YAML specification identifies an "instance document" as a "Presentation" or "character stream". The primary logical structures in a YAML instance document are scalars, sequences, and mappings. The YAML specification also indicates some basic constraints that apply to these primary logical structures. For example, according to the specification, mapping keys do not have an order. In every case where node order is significant, a sequence must be used.


title: YAML

text: Moreover, in defining conformance for YAML processors, the YAML specification defines two primary operations: "dump" and "load". All YAML-compliant processors must provide "at least" one of these operations, and may optionally provide both. Finally, the YAML specification defines an "information model" or "representation graph", which must be created during processing for both "dump" and "load" operations, although this representation need not be made available to the user through an API.


title: YAML

text: JSON syntax is a basis of YAML version 1.2, which was promulgated with the express purpose of bringing YAML "into compliance with JSON as an official subset". Though prior versions of YAML were not strictly compatible, the discrepancies were rarely noticeable, and most JSON documents can be parsed by some YAML parsers such as Syck. This is because JSON's semantic structure is equivalent to the optional "inline-style" of writing YAML. While extended hierarchies can be written in inline-style like JSON, this is not a recommended YAML style except when it aids clarity.


title: YAML

text: YAML has many additional features lacking in JSON, including comments, extensible data types, relational anchors, strings without quotation marks, and mapping types preserving key order.


title: YAML

text: TOML was designed to be an advancement to the .ini file format. YAML's minimal use of indicator characters is compared favorably to TOML's strict requirement of quotation marks and square brackets. YAML's use of significant indentation and nesting allows for less verbose structures, a feature which TOML does not have on a comparable syntactical level, instead relying on dot notation in their key and table names to convey the same semantic structure.


title: YAML

text: YAML lacks the notion of tag attributes that are found in XML. Instead YAML has extensible type declarations (including class types for objects).


title: YAML

text: YAML itself does not have XML's language-defined document schema descriptors that allow, for example, a document to self-validate. However, there are several externally defined schema descriptor languages for YAML (e.g. Doctrine, Kwalify and Rx) that fulfill that role. Moreover, the semantics provided by YAML's language-defined type declarations in the YAML document itself frequently relaxes the need for a validator in simple, common situations. Additionally, YAXML, which represents YAML data structures in XML, allows XML schema importers and output mechanisms like XSLT to be applied to YAML.


title: YAML

text: Comparison of data-serialization formats provides a more comprehensive comparison of YAML with other serialization formats.


title: YAML

text: For fixed data structures, YAML files can simply be generated using "print" commands that write both the data and the YAML specific decoration. To dump varying, or complex, hierarchical data, however, a dedicated YAML "emitter" is preferable. Similarly, simple YAML files (e.g. key-value pairs) are readily parsed with regular expressions. For more complex, or varying, data structures, a formal YAML "parser" is recommended.


title: YAML

text: YAML emitters and parsers exist for many popular languages. Most of them are written in the native language itself. Some are language bindings of the C library "libyaml"; they may run faster. There used to be another C library, called "Syck", written and orphaned by why the lucky stiff: it is unmaintained, there is no authoritative source bundle, and the web site has been hijacked. Hence the only recommendable C library is "libyaml". It was originally developed by Kirill Simonov. In 2018, development was resumed by the new maintainers Ian Cordasco and Ingy döt Net.


title: YAML

text: C++ programmers have the choice between the C library "libyaml" and the C++ library "libyaml-cpp". Both have completely independent code bases and completely different APIs. The library "libyaml-cpp" still has a major version number of 0, indicating that the API may change at any moment, as happened indeed after version 0.3. There is a grammar-focused implementation written in C#, with an aim on extensions for the nested elements.


title: YAML

text: Some implementations of YAML, such as Perl's YAML.pm, will load an entire file (stream) and parse it "en masse". Other implementations like PyYaml are lazy and iterate over the next document only upon request. For very large files in which one plans to handle the documents independently, instantiating the entire file before processing may be prohibitive. Thus in YAML.pm, occasionally one must chunk a file into documents and parse those individually. YAML makes this easy, since this simply requires splitting on the document end marker, which is defined as three periods at the start of a line followed by a whitespace (and possible a comment). This marker is forbidden in content.


title: YAML

text: YAML has been criticized for its significant whitespace, confusing features, insecure defaults, and its complex and ambiguous specification:


title: YAML

text: The perceived flaws and complexity of YAML has led to the emergence of stricter alternatives such as StrictYAML and NestedText.


title: Tertiary sector of the economy

text: The tertiary sector of the economy, generally known as the service sector, is the third of the three economic sectors in the three-sector model (also known as the economic cycle). The others are the primary sector (raw materials) and the secondary sector (manufacturing).


title: Tertiary sector of the economy

text: The tertiary sector consists of the provision of services instead of end products. Services (also known as "intangible goods") include attention, advice, access, experience and affective labor. The production of information has been long regarded as a service, but some economists now attribute it to a fourth sector, called the quaternary sector.


title: Tertiary sector of the economy

text: The tertiary sector involves the provision of services to other businesses as well as to final consumers. Services may involve the transport, distribution and sale of goods from a producer to a consumer, as may happen in wholesaling and retailing, pest control or entertainment. The goods may be transformed in the process of providing the service, as happens in the restaurant industry. However, the focus is on people by interacting with them and serving the customers rather than transforming the physical goods.


title: Tertiary sector of the economy

text: It is sometimes hard to determine whether a given company is part of the secondary or the tertiary sector. It is not only companies that have been classified as part of a sector in some schemes, since governments and their services (such as the police or military), as well as nonprofit organizations (such as charities or research associations), can also be seen as part of that sector.


title: Tertiary sector of the economy

text: In order to classify a business as a service, one can use classification systems such as the United Nations' International Standard Industrial Classification standard, the United States' Standard Industrial Classification (SIC) code system and its new replacement, the North American Industrial Classification System (NAICS), the Statistical Classification of Economic Activities in the European Community (NACE) in the EU and similar systems elsewhere. These governmental classification systems have a first-level of hierarchy that reflects whether the economic goods are tangible or intangible.


title: Tertiary sector of the economy

text: For purposes of finance and market research, market-based classification systems such as the Global Industry Classification Standard and the Industry Classification Benchmark are used to classify businesses that participate in the service sector. Unlike governmental classification systems, the first level of market-based classification systems divides the economy into functionally related markets or industries. The second or third level of these hierarchies then reflects whether goods or services are produced.


title: Tertiary sector of the economy

text: For the last 100 years, there has been a substantial shift from the primary and secondary sectors to the tertiary sector in industrialized countries. This shift is called tertiarisation. The tertiary sector is now the largest sector of the economy in the Western world, and is also the fastest-growing sector.


title: Tertiary sector of the economy

text: In examining the growth of the service sector in the early nineties, the globalist Kenichi Ohmae noted that:


title: Tertiary sector of the economy

text: Economies tend to follow a developmental progression that takes them from heavy reliance on agriculture and mining, toward the development of manufacturing (e.g. automobiles, textiles, shipbuilding, steel) and finally toward a more service-based structure. The first economy to follow this path in the modern world was the United Kingdom. The speed at which other economies have made the transition to service-based (or "post-industrial") economies has increased over time.


title: Tertiary sector of the economy

text: Historically, manufacturing tended to be more open to international trade and competition than services. However, with dramatic cost reduction and speed and reliability improvements in the transportation of people and the communication of information, the service sector now includes some of the most intensive international competition, despite residual protectionism.


title: Tertiary sector of the economy

text: Service providers face obstacles selling services that goods-sellers rarely face. Services are intangible, making it difficult for potential customers to understand what they will receive and what value it will hold for them. Indeed, some, such as consultants and providers of investment services, offer no guarantees of the value for price paid.


title: Tertiary sector of the economy

text: Since the quality of most services depends largely on the quality of the individuals providing the services, "people costs" are usually a high fraction of service costs. Whereas a manufacturer may use technology, simplification, and other techniques to lower the cost of goods sold, the service provider often faces an unrelenting pattern of increasing costs.


title: Tertiary sector of the economy

text: Product differentiation is often difficult. For example, how does one choose one investment adviser over another, since they are often seen to provide identical services? Charging a premium for services is usually an option only for the most established firms, who charge extra based upon brand recognition.


title: Quantum field theory

text: In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines classical field theory, special relativity, and quantum mechanics. QFT is used in particle physics to construct physical models of subatomic particles and in condensed matter physics to construct models of quasiparticles.


title: Quantum field theory

text: QFT treats particles as excited states (also called quanta) of their underlying quantum fields, which are more fundamental than the particles. The quantum field of a particle is determined by minimization of the Lagrangian, a functional of fields associated with the particle. Interactions between particles are described by interaction terms in the Lagrangian involving their corresponding quantum fields. Each interaction can be visually represented by Feynman diagrams according to perturbation theory in quantum mechanics.


title: Quantum field theory

text: Quantum field theory emerged from the work of generations of theoretical physicists spanning much of the 20th century. Its development began in the 1920s with the description of interactions between light and electrons, culminating in the first quantum field theory—quantum electrodynamics. A major theoretical obstacle soon followed with the appearance and persistence of various infinities in perturbative calculations, a problem only resolved in the 1950s with the invention of the renormalization procedure. A second major barrier came with QFT's apparent inability to describe the weak and strong interactions, to the point where some theorists called for the abandonment of the field theoretic approach. The development of gauge theory and the completion of the Standard Model in the 1970s led to a renaissance of quantum field theory.


title: Quantum field theory

text: Quantum field theory results from the combination of classical field theory, quantum mechanics, and special relativity. A brief overview of these theoretical precursors follows.


title: Quantum field theory

text: The earliest successful classical field theory is one that emerged from Newton's law of universal gravitation, despite the complete absence of the concept of fields from his 1687 treatise "Philosophiæ Naturalis Principia Mathematica". The force of gravity as described by Newton is an "action at a distance"—its effects on faraway objects are instantaneous, no matter the distance. In an exchange of letters with Richard Bentley, however, Newton stated that "it is inconceivable that inanimate brute matter should, without the mediation of something else which is not material, operate upon and affect other matter without mutual contact." It was not until the 18th century that mathematical physicists discovered a convenient description of gravity based on fields—a numerical quantity (a vector in the case of gravitational field) assigned to every point in space indicating the action of gravity on any particle at that point. However, this was considered merely a mathematical trick.


title: Quantum field theory

text: Fields began to take on an existence of their own with the development of electromagnetism in the 19th century. Michael Faraday coined the English term "field" in 1845. He introduced fields as properties of space (even when it is devoid of matter) having physical effects. He argued against "action at a distance", and proposed that interactions between objects occur via space-filling "lines of force". This description of fields remains to this day.


title: Quantum field theory

text: The theory of classical electromagnetism was completed in 1864 with Maxwell's equations, which described the relationship between the electric field, the magnetic field, electric current, and electric charge. Maxwell's equations implied the existence of electromagnetic waves, a phenomenon whereby electric and magnetic fields propagate from one spatial point to another at a finite speed, which turns out to be the speed of light. Action-at-a-distance was thus conclusively refuted.


title: Quantum field theory

text: Despite the enormous success of classical electromagnetism, it was unable to account for the discrete lines in atomic spectra, nor for the distribution of blackbody radiation in different wavelengths. Max Planck's study of blackbody radiation marked the beginning of quantum mechanics. He treated atoms, which absorb and emit electromagnetic radiation, as tiny oscillators with the crucial property that their energies can only take on a series of discrete, rather than continuous, values. These are known as quantum harmonic oscillators. This process of restricting energies to discrete values is called quantization. Building on this idea, Albert Einstein proposed in 1905 an explanation for the photoelectric effect, that light is composed of individual packets of energy called photons (the quanta of light). This implied that the electromagnetic radiation, while being waves in the classical electromagnetic field, also exists in the form of particles.


title: Quantum field theory

text: In 1913, Niels Bohr introduced the Bohr model of atomic structure, wherein electrons within atoms can only take on a series of discrete, rather than continuous, energies. This is another example of quantization. The Bohr model successfully explained the discrete nature of atomic spectral lines. In 1924, Louis de Broglie proposed the hypothesis of wave–particle duality, that microscopic particles exhibit both wave-like and particle-like properties under different circumstances. Uniting these scattered ideas, a coherent discipline, quantum mechanics, was formulated between 1925 and 1926, with important contributions from Max Planck, Louis de Broglie, Werner Heisenberg, Max Born, Erwin Schrödinger, Paul Dirac, and Wolfgang Pauli.


title: Quantum field theory

text: In the same year as his paper on the photoelectric effect, Einstein published his theory of special relativity, built on Maxwell's electromagnetism. New rules, called Lorentz transformations, were given for the way time and space coordinates of an event change under changes in the observer's velocity, and the distinction between time and space was blurred. It was proposed that all physical laws must be the same for observers at different velocities, i.e. that physical laws be invariant under Lorentz transformations.


title: Quantum field theory

text: Two difficulties remained. Observationally, the Schrödinger equation underlying quantum mechanics could explain the stimulated emission of radiation from atoms, where an electron emits a new photon under the action of an external electromagnetic field, but it was unable to explain spontaneous emission, where an electron spontaneously decreases in energy and emits a photon even without the action of an external electromagnetic field. Theoretically, the Schrödinger equation could not describe photons and was inconsistent with the principles of special relativity—it treats time as an ordinary number while promoting spatial coordinates to linear operators.


title: Quantum field theory

text: Quantum field theory naturally began with the study of electromagnetic interactions, as the electromagnetic field was the only known classical field as of the 1920s.


title: Quantum field theory

text: Through the works of Born, Heisenberg, and Pascual Jordan in 1925–1926, a quantum theory of the free electromagnetic field (one with no interactions with matter) was developed via canonical quantization by treating the electromagnetic field as a set of quantum harmonic oscillators. With the exclusion of interactions, however, such a theory was yet incapable of making quantitative predictions about the real world.


title: Quantum field theory

text: In his seminal 1927 paper "The quantum theory of the emission and absorption of radiation", Dirac coined the term quantum electrodynamics (QED), a theory that adds upon the terms describing the free electromagnetic field an additional interaction term between electric current density and the electromagnetic vector potential. Using first-order perturbation theory, he successfully explained the phenomenon of spontaneous emission. According to the uncertainty principle in quantum mechanics, quantum harmonic oscillators cannot remain stationary, but they have a non-zero minimum energy and must always be oscillating, even in the lowest energy state (the ground state). Therefore, even in a perfect vacuum, there remains an oscillating electromagnetic field having zero-point energy. It is this quantum fluctuation of electromagnetic fields in the vacuum that "stimulates" the spontaneous emission of radiation by electrons in atoms. Dirac's theory was hugely successful in explaining both the emission and absorption of radiation by atoms; by applying second-order perturbation theory, it was able to account for the scattering of photons, resonance fluorescence and non-relativistic Compton scattering. Nonetheless, the application of higher-order perturbation theory was plagued with problematic infinities in calculations.


title: Quantum field theory

text: In 1928, Dirac wrote down a wave equation that described relativistic electrons—the Dirac equation. It had the following important consequences: the spin of an electron is 1/2; the electron "g"-factor is 2; it led to the correct Sommerfeld formula for the fine structure of the hydrogen atom; and it could be used to derive the Klein–Nishina formula for relativistic Compton scattering. Although the results were fruitful, the theory also apparently implied the existence of negative energy states, which would cause atoms to be unstable, since they could always decay to lower energy states by the emission of radiation.


title: Quantum field theory

text: The prevailing view at the time was that the world was composed of two very different ingredients: material particles (such as electrons) and quantum fields (such as photons). Material particles were considered to be eternal, with their physical state described by the probabilities of finding each particle in any given region of space or range of velocities. On the other hand, photons were considered merely the excited states of the underlying quantized electromagnetic field, and could be freely created or destroyed. It was between 1928 and 1930 that Jordan, Eugene Wigner, Heisenberg, Pauli, and Enrico Fermi discovered that material particles could also be seen as excited states of quantum fields. Just as photons are excited states of the quantized electromagnetic field, so each type of particle had its corresponding quantum field: an electron field, a proton field, etc. Given enough energy, it would now be possible to create material particles. Building on this idea, Fermi proposed in 1932 an explanation for beta decay known as Fermi's interaction. Atomic nuclei do not contain electrons "per se", but in the process of decay, an electron is created out of the surrounding electron field, analogous to the photon created from the surrounding electromagnetic field in the radiative decay of an excited atom.


title: Quantum field theory

text: It was realized in 1929 by Dirac and others that negative energy states implied by the Dirac equation could be removed by assuming the existence of particles with the same mass as electrons but opposite electric charge. This not only ensured the stability of atoms, but it was also the first proposal of the existence of antimatter. Indeed, the evidence for positrons was discovered in 1932 by Carl David Anderson in cosmic rays. With enough energy, such as by absorbing a photon, an electron-positron pair could be created, a process called pair production; the reverse process, annihilation, could also occur with the emission of a photon. This showed that particle numbers need not be fixed during an interaction. Historically, however, positrons were at first thought of as "holes" in an infinite electron sea, rather than a new kind of particle, and this theory was referred to as the Dirac hole theory. QFT naturally incorporated antiparticles in its formalism.


title: Quantum field theory

text: Robert Oppenheimer showed in 1930 that higher-order perturbative calculations in QED always resulted in infinite quantities, such as the electron self-energy and the vacuum zero-point energy of the electron and photon fields, suggesting that the computational methods at the time could not properly deal with interactions involving photons with extremely high momenta. It was not until 20 years later that a systematic approach to remove such infinities was developed.


title: Quantum field theory

text: A series of papers was published between 1934 and 1938 by Ernst Stueckelberg that established a relativistically invariant formulation of QFT. In 1947, Stueckelberg also independently developed a complete renormalization procedure. Unfortunately, such achievements were not understood and recognized by the theoretical community.


title: Quantum field theory

text: Faced with these infinities, John Archibald Wheeler and Heisenberg proposed, in 1937 and 1943 respectively, to supplant the problematic QFT with the so-called S-matrix theory. Since the specific details of microscopic interactions are inaccessible to observations, the theory should only attempt to describe the relationships between a small number of observables ("e.g." the energy of an atom) in an interaction, rather than be concerned with the microscopic minutiae of the interaction. In 1945, Richard Feynman and Wheeler daringly suggested abandoning QFT altogether and proposed action-at-a-distance as the mechanism of particle interactions.


title: Quantum field theory

text: In 1947, Willis Lamb and Robert Retherford measured the minute difference in the "S" and "P" energy levels of the hydrogen atom, also called the Lamb shift. By ignoring the contribution of photons whose energy exceeds the electron mass, Hans Bethe successfully estimated the numerical value of the Lamb shift. Subsequently, Norman Myles Kroll, Lamb, James Bruce French, and Victor Weisskopf again confirmed this value using an approach in which infinities cancelled other infinities to result in finite quantities. However, this method was clumsy and unreliable and could not be generalized to other calculations.


title: Quantum field theory

text: The breakthrough eventually came around 1950 when a more robust method for eliminating infinities was developed by Julian Schwinger, Richard Feynman, Freeman Dyson, and Shinichiro Tomonaga. The main idea is to replace the calculated values of mass and charge, infinite though they may be, by their finite measured values. This systematic computational procedure is known as renormalization and can be applied to arbitrary order in perturbation theory. As Tomonaga said in his Nobel lecture:Since those parts of the modified mass and charge due to field reactions [become infinite], it is impossible to calculate them by the theory. However, the mass and charge observed in experiments are not the original mass and charge but the mass and charge as modified by field reactions, and they are finite. On the other hand, the mass and charge appearing in the theory are… the values modified by field reactions. Since this is so, and particularly since the theory is unable to calculate the modified mass and charge, we may adopt the procedure of substituting experimental values for them phenomenologically... This procedure is called the renormalization of mass and charge… After long, laborious calculations, less skillful than Schwinger's, we obtained a result... which was in agreement with [the] Americans'.


title: Quantum field theory

text: By applying the renormalization procedure, calculations were finally made to explain the electron's anomalous magnetic moment (the deviation of the electron "g"-factor from 2) and vacuum polarization. These results agreed with experimental measurements to a remarkable degree, thus marking the end of a "war against infinities".


title: Quantum field theory

text: At the same time, Feynman introduced the path integral formulation of quantum mechanics and Feynman diagrams. The latter can be used to visually and intuitively organize and to help compute terms in the perturbative expansion. Each diagram can be interpreted as paths of particles in an interaction, with each vertex and line having a corresponding mathematical expression, and the product of these expressions gives the scattering amplitude of the interaction represented by the diagram.


title: Quantum field theory

text: It was with the invention of the renormalization procedure and Feynman diagrams that QFT finally arose as a complete theoretical framework.


title: Quantum field theory

text: Given the tremendous success of QED, many theorists believed, in the few years after 1949, that QFT could soon provide an understanding of all microscopic phenomena, not only the interactions between photons, electrons, and positrons. Contrary to this optimism, QFT entered yet another period of depression that lasted for almost two decades.


title: Quantum field theory

text: The first obstacle was the limited applicability of the renormalization procedure. In perturbative calculations in QED, all infinite quantities could be eliminated by redefining a small (finite) number of physical quantities (namely the mass and charge of the electron). Dyson proved in 1949 that this is only possible for a small class of theories called "renormalizable theories", of which QED is an example. However, most theories, including the Fermi theory of the weak interaction, are "non-renormalizable". Any perturbative calculation in these theories beyond the first order would result in infinities that could not be removed by redefining a finite number of physical quantities.


title: Quantum field theory

text: The second major problem stemmed from the limited validity of the Feynman diagram method, which is based on a series expansion in perturbation theory. In order for the series to converge and low-order calculations to be a good approximation, the coupling constant, in which the series is expanded, must be a sufficiently small number. The coupling constant in QED is the fine-structure constant , which is small enough that only the simplest, lowest order, Feynman diagrams need to be considered in realistic calculations. In contrast, the coupling constant in the strong interaction is roughly of the order of one, making complicated, higher order, Feynman diagrams just as important as simple ones. There was thus no way of deriving reliable quantitative predictions for the strong interaction using perturbative QFT methods.


title: Quantum field theory

text: With these difficulties looming, many theorists began to turn away from QFT. Some focused on symmetry principles and conservation laws, while others picked up the old S-matrix theory of Wheeler and Heisenberg. QFT was used heuristically as guiding principles, but not as a basis for quantitative calculations.


title: Quantum field theory

text: Schwinger, however, took a different route. For more than a decade he and his students had been nearly the only exponents of field theory, but in 1966 he found a way around the problem of the infinities with a new method he called source theory. Developments in pion physics, in which the new viewpoint was most successfully applied, convinced him of the great advantages of mathematical simplicity and conceptual clarity that its use bestowed.


title: Quantum field theory

text: In source theory there are no divergences, and no renormalization. It may be regarded as the calculational tool of field theory, but it is more general. Using source theory, Schwinger was able to calculate the anomalous magnetic moment of the electron, which he had done in 1947, but this time with no ‘distracting remarks’ about infinite quantities.


title: Quantum field theory

text: Schwinger also applied source theory to his QFT theory of gravity, and was able to reproduce all four of Einstein’s classic results: gravitational red shift, deflection and slowing of light by gravity, and the perihelion precession of Mercury. The neglect of source theory by the physics community was a major disappointment for Schwinger:The lack of appreciation of these facts by others was depressing, but understandable. -J. Schwinger


title: Quantum field theory

text: In 1954, Yang Chen-Ning and Robert Mills generalized the local symmetry of QED, leading to non-Abelian gauge theories (also known as Yang–Mills theories), which are based on more complicated local symmetry groups. In QED, (electrically) charged particles interact via the exchange of photons, while in non-Abelian gauge theory, particles carrying a new type of "charge" interact via the exchange of massless gauge bosons. Unlike photons, these gauge bosons themselves carry charge.


title: Quantum field theory

text: Sheldon Glashow developed a non-Abelian gauge theory that unified the electromagnetic and weak interactions in 1960. In 1964, Abdus Salam and John Clive Ward arrived at the same theory through a different path. This theory, nevertheless, was non-renormalizable.


title: Quantum field theory

text: Peter Higgs, Robert Brout, François Englert, Gerald Guralnik, Carl Hagen, and Tom Kibble proposed in their famous "Physical Review Letters" papers that the gauge symmetry in Yang–Mills theories could be broken by a mechanism called spontaneous symmetry breaking, through which originally massless gauge bosons could acquire mass.


title: Quantum field theory

text: By combining the earlier theory of Glashow, Salam, and Ward with the idea of spontaneous symmetry breaking, Steven Weinberg wrote down in 1967 a theory describing electroweak interactions between all leptons and the effects of the Higgs boson. His theory was at first mostly ignored, until it was brought back to light in 1971 by Gerard 't Hooft's proof that non-Abelian gauge theories are renormalizable. The electroweak theory of Weinberg and Salam was extended from leptons to quarks in 1970 by Glashow, John Iliopoulos, and Luciano Maiani, marking its completion.


title: Quantum field theory

text: Harald Fritzsch, Murray Gell-Mann, and Heinrich Leutwyler discovered in 1971 that certain phenomena involving the strong interaction could also be explained by non-Abelian gauge theory. Quantum chromodynamics (QCD) was born. In 1973, David Gross, Frank Wilczek, and Hugh David Politzer showed that non-Abelian gauge theories are "asymptotically free", meaning that under renormalization, the coupling constant of the strong interaction decreases as the interaction energy increases. (Similar discoveries had been made numerous times previously, but they had been largely ignored.) Therefore, at least in high-energy interactions, the coupling constant in QCD becomes sufficiently small to warrant a perturbative series expansion, making quantitative predictions for the strong interaction possible.


title: Quantum field theory

text: These theoretical breakthroughs brought about a renaissance in QFT. The full theory, which includes the electroweak theory and chromodynamics, is referred to today as the Standard Model of elementary particles. The Standard Model successfully describes all fundamental interactions except gravity, and its many predictions have been met with remarkable experimental confirmation in subsequent decades. The Higgs boson, central to the mechanism of spontaneous symmetry breaking, was finally detected in 2012 at CERN, marking the complete verification of the existence of all constituents of the Standard Model.


title: Quantum field theory

text: The 1970s saw the development of non-perturbative methods in non-Abelian gauge theories. The 't Hooft–Polyakov monopole was discovered theoretically by 't Hooft and Alexander Polyakov, flux tubes by Holger Bech Nielsen and Poul Olesen, and instantons by Polyakov and coauthors. These objects are inaccessible through perturbation theory.


title: Quantum field theory

text: Supersymmetry also appeared in the same period. The first supersymmetric QFT in four dimensions was built by Yuri Golfand and Evgeny Likhtman in 1970, but their result failed to garner widespread interest due to the Iron Curtain. Supersymmetry only took off in the theoretical community after the work of Julius Wess and Bruno Zumino in 1973.


title: Quantum field theory

text: Among the four fundamental interactions, gravity remains the only one that lacks a consistent QFT description. Various attempts at a theory of quantum gravity led to the development of string theory, itself a type of two-dimensional QFT with conformal symmetry. Joël Scherk and John Schwarz first proposed in 1974 that string theory could be "the" quantum theory of gravity.


title: Quantum field theory

text: Although quantum field theory arose from the study of interactions between elementary particles, it has been successfully applied to other physical systems, particularly to many-body systems in condensed matter physics.


title: Quantum field theory

text: Historically, the Higgs mechanism of spontaneous symmetry breaking was a result of Yoichiro Nambu's application of superconductor theory to elementary particles, while the concept of renormalization came out of the study of second-order phase transitions in matter.


title: Quantum field theory

text: Soon after the introduction of photons, Einstein performed the quantization procedure on vibrations in a crystal, leading to the first quasiparticle—phonons. Lev Landau claimed that low-energy excitations in many condensed matter systems could be described in terms of interactions between a set of quasiparticles. The Feynman diagram method of QFT was naturally well suited to the analysis of various phenomena in condensed matter systems.


title: Quantum field theory

text: Gauge theory is used to describe the quantization of magnetic flux in superconductors, the resistivity in the quantum Hall effect, as well as the relation between frequency and voltage in the AC Josephson effect.


title: Quantum field theory

text: For simplicity, natural units are used in the following sections, in which the reduced Planck constant and the speed of light are both set to one.


title: Quantum field theory

text: A classical field is a function of spatial and time coordinates. Examples include the gravitational field in Newtonian gravity and the electric field and magnetic field in classical electromagnetism. A classical field can be thought of as a numerical quantity assigned to every point in space that changes in time. Hence, it has infinitely many degrees of freedom.


title: Quantum field theory

text: Many phenomena exhibiting quantum mechanical properties cannot be explained by classical fields alone. Phenomena such as the photoelectric effect are best explained by discrete particles (photons), rather than a spatially continuous field. The goal of quantum field theory is to describe various quantum mechanical phenomena using a modified concept of fields.


title: Quantum field theory

text: Canonical quantization and path integrals are two common formulations of QFT. To motivate the fundamentals of QFT, an overview of classical field theory follows.


title: Quantum field theory

text: The simplest classical field is a real scalar field — a real number at every point in space that changes in time. It is denoted as , where is the position vector, and is the time. Suppose the Lagrangian of the field, formula_1, is


title: Quantum field theory

text: where formula_3 is the Lagrangian density, formula_4 is the time-derivative of the field, is the gradient operator, and is a real parameter (the "mass" of the field). Applying the Euler–Lagrange equation on the Lagrangian:


title: Quantum field theory

text: The Klein–Gordon equation is a wave equation, so its solutions can be expressed as a sum of normal modes (obtained via Fourier transform) as follows:


title: Quantum field theory

text: where is a complex number (normalized by convention), denotes complex conjugation, and is the frequency of the normal mode:


title: Quantum field theory

text: where , and denotes the covariant derivative. The Lagrangian of a QFT, hence its calculational results and physical predictions, depends on the geometry of the spacetime background.


title: Quantum field theory

text: The correlation functions and physical predictions of a QFT depend on the spacetime metric . For a special class of QFTs called topological quantum field theories (TQFTs), all correlation functions are independent of continuous changes in the spacetime metric. QFTs in curved spacetime generally change according to the "geometry" (local structure) of the spacetime background, while TQFTs are invariant under spacetime diffeomorphisms but are sensitive to the "topology" (global structure) of spacetime. This means that all calculational results of TQFTs are topological invariants of the underlying spacetime. Chern–Simons theory is an example of TQFT and has been used to construct models of quantum gravity. Applications of TQFT include the fractional quantum Hall effect and topological quantum computers. The world line trajectory of fractionalized particles (known as anyons) can form a link configuration in the spacetime, which relates the braiding statistics of anyons in physics to the


title: Quantum field theory

text: link invariants in mathematics. Topological quantum field theories (TQFTs) applicable to the frontier research of topological quantum matters include Chern-Simons-Witten gauge theories in 2+1 spacetime dimensions, other new exotic TQFTs in 3+1 spacetime dimensions and beyond.


title: Quantum field theory

text: Using perturbation theory, the total effect of a small interaction term can be approximated order by order by a series expansion in the number of virtual particles participating in the interaction. Every term in the expansion may be understood as one possible way for (physical) particles to interact with each other via virtual particles, expressed visually using a Feynman diagram. The electromagnetic force between two electrons in QED is represented (to first order in perturbation theory) by the propagation of a virtual photon. In a similar manner, the W and Z bosons carry the weak interaction, while gluons carry the strong interaction. The interpretation of an interaction as a sum of intermediate states involving the exchange of various virtual particles only makes sense in the framework of perturbation theory. In contrast, non-perturbative methods in QFT treat the interacting Lagrangian as a whole without any series expansion. Instead of particles that carry interactions, these methods have spawned such concepts as 't Hooft–Polyakov monopole, domain wall, flux tube, and instanton. Examples of QFTs that are completely solvable non-perturbatively include minimal models of conformal field theory and the Thirring model.


title: Quantum field theory

text: In spite of its overwhelming success in particle physics and condensed matter physics, QFT itself lacks a formal mathematical foundation. For example, according to Haag's theorem, there does not exist a well-defined interaction picture for QFT, which implies that perturbation theory of QFT, which underlies the entire Feynman diagram method, is fundamentally ill-defined.


title: Quantum field theory

text: However, "perturbative" quantum field theory, which only requires that quantities be computable as a formal power series without any convergence requirements, can be given a rigorous mathematical treatment. In particular, Kevin Costello's monograph "Renormalization and Effective Field Theory" provides a rigorous formulation of perturbative renormalization that combines both the effective-field theory approaches of Kadanoff, Wilson, and Polchinski, together with the Batalin-Vilkovisky approach to quantizing gauge theories. Furthermore, perturbative path-integral methods, typically understood as formal computational methods inspired from finite-dimensional integration theory, can be given a sound mathematical interpretation from their finite-dimensional analogues.


title: Quantum field theory

text: Since the 1950s, theoretical physicists and mathematicians have attempted to organize all QFTs into a set of axioms, in order to establish the existence of concrete models of relativistic QFT in a mathematically rigorous way and to study their properties. This line of study is called constructive quantum field theory, a subfield of mathematical physics, which has led to such results as CPT theorem, spin–statistics theorem, and Goldstone's theorem, and also to mathematically rigorous constructions of many interacting QFTs in two and three spacetime dimensions, e.g. two-dimensional scalar field theories with arbitrary polynomial interactions, the three-dimensional scalar field theories with a quartic interaction, etc.


title: Quantum field theory

text: Compared to ordinary QFT, topological quantum field theory and conformal field theory are better supported mathematically — both can be classified in the framework of representations of cobordisms.


title: Quantum field theory

text: Algebraic quantum field theory is another approach to the axiomatization of QFT, in which the fundamental objects are local operators and the algebraic relations between them. Axiomatic systems following this approach include Wightman axioms and Haag–Kastler axioms. One way to construct theories satisfying Wightman axioms is to use Osterwalder–Schrader axioms, which give the necessary and sufficient conditions for a real time theory to be obtained from an imaginary time theory by analytic continuation (Wick rotation).


title: Quantum field theory

text: Yang–Mills existence and mass gap, one of the Millennium Prize Problems, concerns the well-defined existence of Yang–Mills theories as set out by the above axioms. The full problem statement is as follows.


title: Álvaro Morte

text: Álvaro Antonio García Pérez (born 23 February 1975), known professionally as Álvaro Morte, is a Spanish actor. He gained worldwide recognition for playing the role of 'The Professor' in the television series "Money Heist".


title: Álvaro Morte

text: Álvaro Antonio García Pérez was born on 23 February 1975 in Algeciras, province of Cádiz, soon relocating to Bujalance, province of Córdoba, with his family.


title: Álvaro Morte

text: Originally enrolled into a degree of communications engineering, he switched to dramatic art, graduating from the "Escuela Superior de Arte Dramático de Córdoba" in 1999. He also took post-graduate studies at the University of Tampere. After his time in Finland, he settled in Madrid. At the age of 33, he was diagnosed with a cancerous tumour in the left thigh, which he ultimately overcame.


title: Álvaro Morte

text: Morte began his acting career when he played a minor role in the Spanish television series "Hospital Central". He landed his first main role in a TV series in "Planta 25", aired on a number of Spanish regional TV broadcasters and in which he played Ray—a driver—from 2007 to 2008. He then played Adolfo Castillo in the Spanish television series "Bandolera", Gabriel Areta in the soap opera "Amar en tiempos revueltos".


title: Álvaro Morte

text: Morte performed a minor role in "Lola, la película" (2007), a biopic film about the folkloric singer Lola Flores in which he briefly portrayed a bullfighter, lover of the protagonist.


title: Álvaro Morte

text: In addition to his acting work, Morte owns a theatre company called 300 pistolas (English: 300 pistols), founded in 2012.


title: Álvaro Morte

text: Morte joined the cast of the long-running telenovela "El secreto de Puente Viejo" in 2014, portraying Lucas Moliner—a small-town physician—until 2017.


title: Álvaro Morte

text: Following his exit from "Puente Viejo", Morte played the role of Sergio "el Profesor" Marquina in the television series "La Casa de Papel". The first season aired on Antena 3 in 2017. He was heavily praised for his portrayal of the character—the meticulous criminal mastermind behind the heist plot central to the series—and has gained, along with the television series, worldwide fame. In late 2017, Netflix acquired the series and distributed it worldwide on its platform. Part two of the final season were released in December 2021.


title: Álvaro Morte

text: Morte starred in the 2019 Movistar+ television series "El embarcadero", playing Óscar, a man who has lived a double life by living with two different women separatedly. In December 2019, Morte was announced to have joined the cast of the Amazon television series "The Wheel of Time", an adaption of the epic fantasy novels of the same name, set to portray Logain.


title: Álvaro Morte

text: In April 2021, he was announced to have been cast as Juan Sebastián Elcano in the miniseries "Sin límites".


title: Gram-negative bacteria

text: Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane.


title: Gram-negative bacteria

text: Gram-negative bacteria are found in virtually all environments on Earth that support life. The gram-negative bacteria include the model organism "Escherichia coli", as well as many pathogenic bacteria, such as "Pseudomonas aeruginosa", "Chlamydia trachomatis", and "Yersinia pestis". They are a significant medical challenge as their outer membrane protects them from many antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and lysozyme, an antimicrobial enzyme produced by animals that forms part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipopolysaccharide (LPS) whose lipid A component can cause a toxic reaction when bacteria are lysed by immune cells. This toxic reaction may lead to low blood pressure, respiratory failure, reduced oxygen delivery, and lactic acidosis – manifestations of septic shock.


title: Gram-negative bacteria

text: Several classes of antibiotics have been designed to target gram-negative bacteria, including aminopenicillins, ureidopenicillins, cephalosporins, beta-lactam-betalactamase inhibitor combinations (e.g. piperacillin-tazobactam), Folate antagonists, quinolones, and carbapenems. Many of these antibiotics also cover gram-positive organisms. The drugs that specifically target gram-negative organisms include aminoglycosides, monobactams (aztreonam) and ciprofloxacin.


title: Gram-negative bacteria

text: Along with cell shape, Gram staining is a rapid diagnostic tool and once was used to group species at the subdivision of Bacteria.


title: Gram-negative bacteria

text: Historically, the kingdom Monera was divided into four divisions based on Gram staining: Firmacutes (+), Gracillicutes (−), Mollicutes (0) and Mendocutes (var.).


title: Gram-negative bacteria

text: Since 1987, the monophyly of the gram-negative bacteria has been disproven with molecular studies. However some authors, such as Cavalier-Smith still treat them as a monophyletic taxon (though not a clade; his definition of monophyly requires a single common ancestor but does not require holophyly, the property that all descendants be encompassed by the taxon) and refer to the group as a subkingdom "Negibacteria".


title: Gram-negative bacteria

text: Bacteria are traditionally classified based on their Gram-staining response into the gram-positive and gram-negative bacteria. Having just one membrane the gram-positive bacteria are also known as monoderm bacteria, and gram-negative having two membranes are also known as diderm bacteria. It was traditionally thought that the groups represent lineages, i.e. the extra membrane only evolved once, such that gram-negative bacteria are more closely related to one another than to any gram-positive bacteria. While this is often true, the classification system breaks down in some cases, with lineage groupings not matching the staining result. Thus, Gram staining cannot be reliably used to assess familial relationships of bacteria. Nevertheless, staining often gives reliable information about the composition of the cell membrane, distinguishing between the presence or absence of an outer lipid membrane.


title: Gram-negative bacteria

text: Of these two structurally distinct groups of prokaryotic organisms, monoderm prokaryotes are thought to be ancestral. Based upon a number of different observations including that the gram-positive bacteria are the most sensitive to antibiotics and that gram-negative bacteria are, in general, resistant to them, it has been proposed that the outer cell membrane in gram-negative bacteria (diderms) evolved as a protective mechanism against antibiotic selection pressure. Some bacteria such as "Deinococcus", which stain gram-positive due to the presence of a thick peptidoglycan layer, but also possess an outer cell membrane are suggested as intermediates in the transition between monoderm (gram-positive) and diderm (gram-negative) bacteria. The diderm bacteria can also be further differentiated between simple diderms lacking lipopolysaccharide (LPS); the archetypical diderm bacteria, in which the outer cell membrane contains lipopolysaccharide; and the diderm bacteria, in which the outer cell membrane is made up of mycolic acid (e. g. "Mycobacterium").


title: Gram-negative bacteria

text: The conventional LPS-"diderm" group of gram-negative bacteria (e.g., Pseudomonadota, Aquificota, Chlamydiota, Bacteroidota, Chlorobiota, "Cyanobacteria", Fibrobacterota, Verrucomicrobiota, Planctomycetota, Spirochaetota, Acidobacteriota; "Hydrobacteria") are uniquely identified by a few conserved signature indel (CSI) in the HSP60 (GroEL) protein. In addition, a number of bacterial taxa (including Negativicutes, Fusobacteriota, Synergistota, and Elusimicrobiota) that are either part of the phylum Bacillota (a monoderm group) or branches in its proximity are also found to possess a diderm cell structure. They lack the GroEL signature. The presence of this CSI in all sequenced species of conventional lipopolysaccharide-containing gram-negative bacterial phyla provides evidence that these phyla of bacteria form a monophyletic clade and that no loss of the outer membrane from any species from this group has occurred.


title: Gram-negative bacteria

text: The proteobacteria are a major superphylum of gram-negative bacteria, including "E. coli", "Salmonella", "Shigella", and other Enterobacteriaceae, "Pseudomonas", "Moraxella", "Helicobacter", "Stenotrophomonas", "Bdellovibrio", acetic acid bacteria, "Legionella" etc. Other notable groups of gram-negative bacteria include the cyanobacteria, spirochaetes, green sulfur, and green non-sulfur bacteria.


title: Gram-negative bacteria

text: Medically relevant gram-negative cocci include the four types that cause a sexually transmitted disease ("Neisseria gonorrhoeae"), a meningitis ("Neisseria meningitidis"), and respiratory symptoms ("Moraxella catarrhalis", "Haemophilus influenzae").


title: Gram-negative bacteria

text: Medically relevant gram-negative bacilli include a multitude of species. Some of them cause primarily respiratory problems ("Klebsiella pneumoniae", "Legionella pneumophila", "Pseudomonas aeruginosa"), primarily urinary problems ("Escherichia coli", "Proteus mirabilis", "Enterobacter cloacae", "Serratia marcescens"), and primarily gastrointestinal problems ("Helicobacter pylori", "Salmonella enteritidis", "Salmonella typhi").


title: Gram-negative bacteria

text: Gram-negative bacteria associated with hospital-acquired infections include "Acinetobacter baumannii", which cause bacteremia, secondary meningitis, and ventilator-associated pneumonia in hospital intensive-care units.


title: Gram-negative bacteria

text: Transformation is one of three processes for horizontal gene transfer, in which exogenous genetic material passes from bacterium to another, the other two being conjugation (transfer of genetic material between two bacterial cells in direct contact) and transduction (injection of foreign DNA by a bacteriophage virus into the host bacterium). In transformation, the genetic material passes through the intervening medium, and uptake is completely dependent on the recipient bacterium.


title: Gram-negative bacteria

text: As of 2014 about 80 species of bacteria were known to be capable of transformation, about evenly divided between gram-positive and gram-negative bacteria; the number might be an overestimate since several of the reports are supported by single papers. Transformation has been studied in medically important gram-negative bacteria species such as "Helicobacter pylori", "Legionella pneumophila", "Neisseria meningitidis", "Neisseria gonorrhoeae", "Haemophilus influenzae" and "Vibrio cholerae". It has also been studied in gram-negative species found in soil such as "Pseudomonas stutzeri", "Acinetobacter baylyi", and gram-negative plant pathogens such as "Ralstonia solanacearum" and "Xylella fastidiosa".


title: Gram-negative bacteria

text: One of the several unique characteristics of gram-negative bacteria is the structure of the bacterial outer membrane. The outer leaflet of this membrane contains lipopolysaccharide (LPS), whose lipid A portion acts as an endotoxin. If gram-negative bacteria enter the circulatory system, LPS can trigger an innate immune response, activating the immune system and producing cytokines (hormonal regulators). This leads to inflammation and can cause a toxic reaction, resulting in fever, an increased respiratory rate, and low blood pressure. That is why some infections with gram-negative bacteria can lead to life-threatening septic shock.


title: Gram-negative bacteria

text: The outer membrane protects the bacteria from several antibiotics, dyes, and detergents that would normally damage either the inner membrane or the cell wall (made of peptidoglycan). The outer membrane provides these bacteria with resistance to lysozyme and penicillin. The periplasmic space (space between the two cell membranes) also contains enzymes which break down or modify antibiotics. Drugs commonly used to treat gram negative infections include amino, carboxy and ureido penicillins (ampicillin, amoxicillin, pipercillin, ticarcillin) these drugs may be combined with beta-lactamase inhibitors to combat the presence of enzymes that can digest these drugs (known as beta-lactamases) in the peri-plasmic space. Other classes of drugs that have gram negative spectrum include cephalosporins, monobactams (aztreonam), aminoglycosides, quinolones, macrolides, chloramphenicol, folate antagonists, and carbapenems.


title: Gram-negative bacteria

text: The adjectives "Gram-positive" and "Gram-negative" derive from the surname of Hans Christian Gram, a Danish bacteriologist; as eponymous adjectives, their initial letter can be either capital "G" or lower-case "g", depending on which style guide (e.g., that of the CDC), if any, governs the document being written. This is further explained at "Gram staining § Orthographic note".