Ontological status.

In his dialogues Plato suggests that concrete beings acquire their essence through their relations to "Forms"abstract universals logically or ontologically separate from the objects of sense perception. These Forms are often put forth as the models or paradigms of which sensible things are "copies". When used in this sense, the word form is often capitalized. Sensible bodies are in constant flux and imperfect and hence, by Plato's reckoning, less real than the Forms which are eternal, unchanging and complete. Typical examples of Forms given by Plato are largeness, smallness, equality, unity, goodness, beauty and justice.  Aristotle moves the Forms of Plato to the nucleus of the individual thing, which is called "ousia" or substance. Essence is the "ti" of the thing, the "to ti en einai". Essence corresponds to the "ousia"'s definition; essence is a real and physical aspect of the "ousia" (Aristotle, "Metaphysics", I).  According to nominalists (Roscelin of Compiègne, William of Ockham, Bernard of Chartres), universals aren't concrete entities, just voice's sounds; there are only individuals: ""nam cum habeat eorum sententia nihil esse praeter individuum [...]"" (Roscelin, "De gener. et spec.", 524). Universals are words that can to call several individuals; for example the word "homo". Therefore, a universal is reduced to a sound's emission (Roscelin, "De generibus et speciebus").  John Locke distinguished between "real essences" and "nominal essences". Real essences are the thing(s) that makes a thing a thing, whereas nominal essences are our conception of what makes a thing a thing.  According to Edmund Husserl essence is "ideal". However, "ideal" means that essence is an intentional object of consciousness. Essence is interpreted as "sense" (E. Husserl, "Ideas pertaining to a pure phenomenology and to a phenomenological philosophy", paragraphs 3 and 4).

Existentialism.

Existentialism was coined by Jean-Paul Sartre's endorsement of Martin Heidegger's statement that for human beings "existence precedes essence." In as much as "essence" is a cornerstone of all metaphysical philosophy and of Rationalism, Sartre's statement was a repudiation of the philosophical system that had come before him (and, in particular, that of Husserl, Hegel, and Heidegger). Instead of "is-ness" generating "actuality," he argued that existence and actuality come first, and the essence is derived afterward. For Kierkegaard, it is the individual person who is the supreme moral entity, and the personal, subjective aspects of human life that are the most important; also, for Kierkegaard all of this had religious implications.

In metaphysics.

"Essence," in metaphysics, is often synonymous with the soul, and some existentialists argue that individuals gain their souls and spirits after they exist, that they develop their souls and spirits during their lifetimes. For Kierkegaard, however, the emphasis was upon essence as "nature." For him, there is no such thing as "human nature" that determines how a human will behave or what a human will be. First, he or she exists, and then comes property. Jean-Paul Sartre's more materialist and skeptical existentialism furthered this existentialist tenet by flatly refuting any metaphysical essence, any soul, and arguing instead that there is merely existence, with attributes as essence.  Thus, in existentialist discourse, essence can refer to physical aspect or property to the ongoing being of a person (the character or internally determined goals), or to the infinite inbound within the human (which can be lost, can atrophy, or can be developed into an equal part with the finite), depending upon the type of existentialist discourse.

Marxism's essentialism.

Karl Marx was a follower of Hegel's thought, and he, too, developed a philosophy in reaction to his master. In his early work, Marx used Aristotelian style teleology and derived a concept of humanity's essential nature. Marx's Economic and Philosophical Manuscripts of 1844 describe a theory of alienation based on human existence being completely different from human essence. Marx said human nature was social, and that humanity had the distinct essence of free activity and conscious thought.  Some scholars, such as Philip Kain, have argued that Marx abandoned the idea of a human essence, but many other scholars point to Marx's continued discussion of these ideas despite the decline of terms such as essence and alienation in his later work.

Buddhism.

Within the Madhyamaka school of Mahayana Buddhism, Candrakirti identifies the self as:  Buddhapālita adds, while commenting on Nagārjuna's Mūlamadhyamakakārikā,  For the Madhyamaka Buddhists, 'Emptiness' (also known as Anatta or Anatman) is the strong assertion that all phenomena are empty of any essence, and that anti-essentialism lies at the root of Buddhist praxis and it is the innate belief in essence that is considered to be an afflictive obscuration which serves as the root of all suffering. However, the Madhyamaka also rejects the tenets of Idealism, Materialism or Nihilism; instead, the ideas of "truth" or "existence", along with any assertions that depend upon them are limited to their function within the contexts and conventions that assert them, possibly somewhat akin to Relativism or Pragmatism. For the Madhyamaka, replacement paradoxes such as Ship of Theseus are answered by stating that the Ship of Theseus remains so (within the conventions that assert it) until it ceases to function as the Ship of Theseus.  In Nagarjuna's Mulamadhyamakakarika Chapter XV examines essence itself.

Hinduism.

In understanding any individual personality, a distinction is made between one's "Swadharma" (essence) and "Swabhava" (mental habits and conditionings of ego personality). Svabhava is the nature of a person, which is a result of his or her samskaras (impressions created in the mind due to one's interaction with the external world). These samskaras create habits and mental models and those become our nature. While there is another kind of svabhava that is a pure internal quality — smarana — we are here focusing only on the svabhava that was created due to samskaras (because to discover the pure, internal svabhava and smarana, one should become aware of one's samskaras and take control over them). Dharma is derived from the root "dhr" "to hold." It is that which holds an entity together. That is, Dharma is that which gives integrity to an entity and holds the core quality and identity (essence), form and function of that entity. Dharma is also defined as righteousness and duty. To do one's dharma is to be righteous, to do one's dharma is to do one's duty (express one's essence).

In philosophy, essence is the property or set of properties that make an entity or substance what it fundamentally is, and which it has by necessity, and without which it loses its identity. Essence is contrasted with accident: a property that the entity or substance has contingently, without which the substance can still retain its identity. The concept originates rigorously with Aristotle (although it can also be found in Plato), who used the Greek expression "to ti ên einai" (τὸ τί ἦν εἶναι, literally meaning "the what it was to be" and corresponding to the scholastic term quiddity) or sometimes the shorter phrase "to ti esti" (τὸ τί ἐστι, literally meaning "the what it is" and corresponding to the scholastic term haecceity) for the same idea. This phrase presented such difficulties for its Latin translators that they coined the word "essentia" (English "essence") to represent the whole expression. For Aristotle and his scholastic followers, the notion of essence is closely linked to that of definition (ὁρισμός "horismos").

Le concept d'essence (du latin "essentia", du verbe "esse", être, parent du grec "ousia") désigne en métaphysique une distinction de l'être. Il désigne, par opposition au concept d'existence qui lui définit « l'acte d'exister ». Accident au contraire, se dit de ce qui appartient à un être et peut en être affirmé avec vérité, mais n’est pourtant ni nécessaire ni constant.


History.

1979–1983: Origins.

In 1979, after having quit college and learned the art of fire breathing, Guy Laliberté organized a summer fair in Baie-Saint-Paul with the help of Daniel Gauthier and Gilles Ste-Croix. As part of a publicity stunt to convince the Quebec government to help fund this production, Ste-Croix walked the from Baie-Saint-Paul to Quebec City on stilts. This gave them funding for the stilt-walking troupe "Les Échassiers de Baie-Saint-Paul", which then toured Quebec the following year in 1980.  Although well received by audiences and critics alike, "Les Échassiers" was a financial failure. Laliberté spent the following winter in Hawaii while Ste-Croix stayed in Quebec to set up a nonprofit holding company named "The High-Heeled Club" ("Club des Talons Hauts)" to mitigate the losses of the previous summer. This allowed "Les Échassiers de Baie-Saint-Paul" to break even by fall 1981. The following summer, Laliberté and Ste-Croix founded "La Fête Foraine", a street performance festival that featured circus performances and workshops to teach the circus arts to the public. Laliberté managed and produced the fair for 2 more years, becoming a moderate financial success. In 1983, the government of Quebec gave him a $1.6 million grant to host a production the following year as part of Quebec's 450th anniversary celebration of the French explorer Jacques Cartier's discovery of Canada. This became Cirque du Soleil's first production "Le Grand Tour du Cirque du Soleil".

1984–1989: Early productions.

The company's first production "Le Grand Tour" performed in Quebec for 13 weeks in summer 1984. Although several issues persisted during the first tour (including a collapsed tent and conflict between artists), it was a financial success. After securing funding from the Canadian government for a second year from the help of Quebec premier René Lévesque, Laliberté hired Guy Caron, head of the National Circus School, as Cirque du Soleil's artistic director. Laliberté and Caron reworked the company's performance style to emulate that of Moscow Circus by having the acts tell a story. Further influences from the Circus of China, Cirque Arlette Gruss, and Circus Roncalli led Cirque du Soleil to approach their shows in a more theatrical fashion with live music and no technical crew on stage. To assist in this shift towards a theatrical production, Laliberté and Caron hired Belgian director Franco Dragone to direct segments of their 1985 production, "Cirque du Soleil".  The company's first non-Quebec performances in Ontario in 1985 were unsuccessful, leading to a $750,000 deficit. To allow a 1986 tour to mount, the Desjardins Group covered $200,000 of bad checks, financier Daniel Lamarre represented the company for free, and the Quebec government allotted it an additional year of funding. "La Magie Continue", their 1986 production, proved more artistically successful with the direction of Franco Dragone. This extended to the creation of their 1987 show "Le Cirque Réinventé".  In the summer of 1987, Cirque du Soleil was invited to present "Le Cirque Réinventé" at the Los Angeles Arts Festival. Despite only having enough money to make a one-way trip, the company agreed to open for the festival in September of that year. "Le Cirque Réinventé"'s first American performances were an instant critical and financial hit, allowing them make a profit of over $1.5 million by the end of 1987. The show continued to tour Canada and the United States throughout 1988 and 1989, during which time plans for a second touring show named "Éclipse" started being developed. Due to artistic differences with these plans, Guy Caron, along with a number of artists, left the company causing the plans to be shelved. Gilles Ste-Croix, who had been away from the company since 1985, subsequently replaced Caron as artistic director.

1990–1999: Expansion.

By the end of 1989, the company once again faced deficit due to internal conflicts amongst the company's leaders as well as from lukewarm reception to their revamped tour of "Le Cirque Réinventé" in the United States. In response to this, Cirque du Soleil took their plans for their previously shelved show "Éclipse" and developed it into "Nouvelle Expérience". Franco Dragone returned as director in addition to a creative team made up of Dominique Lemieux, Michel Crête, René Dupéré, Luc Lafortune, and Debra Brown. "Nouvelle Expérience" premiered on 8 May 1990 in Montreal to critical acclaim, touring North America through the end of 1991 and later residing in Las Vegas in 1992 and 1993. Their following touring shows — "Saltimbanco", "Alegría", "Quidam", and "Dralion" — proved to be equally successful.  The success of "Nouvelle Expérience"'s contract in Las Vegas led to a deal between Cirque du Soleil and the Mirage Casino-Hotel to create a permanent show, "Mystère", residing in Treasure Island Hotel and Casino on the Las Vegas Strip. It premiered in December 1993. Its success as the company's first permanent production would later allow for the creation of two more permanent shows in 1998: "O" in Las Vegas and "La Nouba" at Walt Disney World in Orlando, Florida. During this time of expansion the company also founded their International Headquarters in Montreal's Saint-Michel neighbourhood and their multimedia division, Cirque du Soleil Images. In 1999 they premiered their film "Alegría", also directed by Dragone.  Following the premiere of "La Nouba" in 1998, the creative team that had developed all of the company's shows from "Nouvelle Expérience" to "La Nouba" left. Starting with the creation of "Dralion" in 1999, Cirque du Soleil began producing shows with entirely new creative teams.

First international ventures.

"Le Cirque Réinventé" marked the company's first performances outside of North America when it performed in London and Paris in 1990. The show received a mixed reception and was not followed by another production until "Saltimbanco"'s 1995 European tour, which better solidified Cirque du Soleil's presence in the European market.  Cirque du Soleil also toured Japan in the summer of 1992 at the behest of the Fuji Television Network. Combining acts from their previous shows "Nouvelle Expérience" and "Le Cirque Réinventé", they created their first arena show "Fascination" which toured Japan from May to August of that year. "Fascination"'s positive reception allowed Cirque du Soleil to play "Saltimbanco" there in 1994, thereby establishing the company's market in the Asia and Pacific region for their subsequent tours in the late 1990s and 2000s.

2000–2009: Rapid growth.

In 2000, the company produced their IMAX film "Journey of Man." Shortly afterwards, at the beginning of 2001, Daniel Gauthier left the company and was bought out by Guy Laliberté, bringing his ownership stake in the company to 95%. Gilles Ste-Croix also soon left to found the horse-based touring show "Cheval", leading Laliberté to hire Lyn Heward and Daniel Lamarre as Presidents and C.O.O.'s of the company's Creative Content and New Ventures divisions, respectively.  In 2002, the company created the touring show "Varekai" and in 2003 premiered the resident show "Zumanity" in Las Vegas, their first "X-rated" show performed only for adults aged 18 years and older. In 2003 they also produced their first television shows: the documentary reality miniseries "" and the variety series "Solstrom." In 2004, Cirque du Soleil premiered the resident show "Kà" at MGM Grand in Las Vegas, directed by Robert Lepage. In September of that year, the company launched their record label, Cirque du Soleil Musique, after their agreement with BMG Canada expired. In 2005, Lamarre took over as President of Cirque du Soleil from Laliberté while Heward took on the role of executive producer for special projects. In that same year the company premiered the touring show "Corteo".  Cirque du Soleil premiered two shows in 2006: "Delirium", their first significant touring arena show, in January of that year and "The Beatles Love", their first collaboration with The Beatles, in June. Similarly, in 2007 they opened two more productions with the resident show "Wintuk" in New York City and the touring tent show "Koozå". In July 2007 the company made their first effort to convert tent shows to arena settings by launching "Saltimbanco"'s arena tour in London, Ontario (this custom would be followed by other tent shows in later years).  The company opened three resident shows within the span of 3 months in 2008 — "Zaia" in Macau, China, "Criss Angel Believe" in Las Vegas, and "Zed" in Tokyo, Japan — which furthered their practice of producing multiple shows at the same time. That year Cirque du Soleil also announced that they sold a 20% stake in the company to Dubai investors Istithmar World and Nakheel in order to finance their goals, which included creating a permanent show in Dubai. In 2009, they launched 3 more shows: the touring tent show "Ovo", the touring theatre show "Banana Shpeel", and the resident show "Viva Elvis" in Las Vegas. At this time Cirque du Soleil began being criticized for the quality of their productions. "Banana Shpeel" became labelled as one of the company's first "failures" when it was panned by both critics and audiences; "Criss Angel Believe" and "Viva Elvis" also received negative reviews.

2010–2015: Cutbacks and restructuring.

The touring show "Totem" premiered in 2010 and was soon followed by three more shows in 2011: the resident show "Iris" in Los Angeles and the touring shows "" and "Zarkana." Although the company was still growing at this time, it continued to face several issues with its newer productions. "Zarkana" and "Michael Jackson: The Immortal World Tour" received poor reviews and the company had a string of closures. "Banana Shpeel" closed in Toronto in October 2010 after cancelling its previously-announced engagement in San Francisco. In July 2011, Cirque du Soleil announced the closure of "Zed" due to poor ticket sales as a direct result of the March 2011 Tōhoku earthquake and tsunami. In November 2011 MGM Grand asked the company to close and replace "Viva Elvis" by the end of 2012 due to poor ticket sales. In February 2012, the company announced the closure of "Zaia" due to disappointing ticket sales and in November 2012, despite critical praise, announced the closure of "Iris," also due to low ticket sales. In December 2012, the company announced a new division — Cirque du Soleil Média — in conjunction with Bell Media, followed by the release of their second film "". At this time Cirque du Soleil also announced 50 layoffs. The layoffs consisted mostly of 30 employee positions at their International Headquarters in Montreal, including three vice-presidents.  With the high output of shows between 2007 and 2011 in combination with its multiple closures, the company began slowing down its operations. In 2012 and 2013 it only opened two shows: the touring tent show "Amaluna" and the resident show "" in Las Vegas. On 16 January 2013, Cirque du Soleil announced that it would be laying off 400 of its 5000 employees worldwide, most of which at their International Headquarters. The company noted that it had not been profitable in 2012 despite having garnered over $1 billion in revenue that year. Later that year, on 30 June 2013, the company faced headlines when acrobat Sarah "Sasoun" Guyard-Guillot died after falling during a performance of "Kà" in Las Vegas, its first on-stage death in its history.  In January 2014, Cirque du Soleil announced the creation of Cirque du Soleil Theatrical, a division aimed developing more traditional theatre productions in order to diversify their production output. The company subsequently announced numerous subsidiaries in addition to its Theatrical division, including the Sandbox Hospitality Group, 45 Degrees, 4U2C, and Outbox Enterprises. In April 2014, "Kurios: Cabinet of Curiosities", a touring tent show, premiered in Montreal to critical acclaim and was followed in November 2014 by "Joyà", both the company's first resident show in Mexico and their first dinner theatre production.  On 20 April 2015, Guy Laliberté announced that he had sold a 90% joint stake in the company to the investment groups TPG Capital, Fosun Capital Group, and La Caisse de dépôt et placement du Québec for approximately $1.5 billion, while retaining a 10% stake in the company himself. Under the new ownership, the company began majorly restructuring its executive leadership in order to focus on increasing their profitability. Their finance director, chief operating officer, and numerous vice-presidents were all replaced within six months of the company's sale. Most notably, the position of chief operating officer held by Charles Décarie was given to finance lawyer Jonathan Tétrault.

2015–present: Rebranding and diversification.

In November 2015 the company premiered the touring arena show "Toruk — The First Flight" based on James Cameron's "Avatar" franchise. It was followed shortly after by the touring tent show "Luzia" and the company's first Broadway musical "Paramour", both opening in April 2016. By the end of 2016 the company had also launched the preschool television series "Luna Petunia" on Netflix. In 2017, it launched three more productions. "Séptimo Día — No Descansaré", an arena show based on the music of Soda Stereo, premiered in March for a short year-long tour targeted largely at South and Central American audiences. In April 2017, it premiered the touring tent show "Volta" and in October, "Crystal", the company's first ice show.  Under the ownership of TPG Capital, Fosun Capital Group, and La Caisse de dépôt et placement du Québec, Cirque du Soleil took steps to diversify and rebrand the company. On 6 July 2017, Cirque du Soleil announced that it had acquired the Blue Man Group as a new subsidiary of the company. It was reportedly bought for US$65.5 million. On 21 November 2017, the company released a video on all of its social media platforms titled "New Icons for a New Era" where it revealed new logos and announced the Cirque du Soleil Entertainment Group as the name of the organization's new umbrella company. On 25 April 2018, the company announced that 45 Degrees, their special events subsidiary, had taken over the main company's creation and production department. On 5 July 2018, they announced their acquisition of the children's entertainment company VStar Entertainment Group and its subsidiary Cirque Dreams.  Cirque du Soleil launched the children's show "Big Top Academy" through TVO in October 2018. In November 2018, it premiered the touring tent show "Bazzar" in India, the company's first production to tour in that region. In 2019, the company opened six shows: the touring tent show "Alegría: In a New Light"; the touring arena shows "Axel" and "Messi10"; and three resident shows — "X: The Land of Fantasy" in Hangzhou, China, "R.U.N" in Las Vegas, and "'Twas the Night Before" in New York City. During this time Cirque du Soleil also acquired The Works Entertainment company for $40 million to further diversify its subsidiaries.  In February 2020, Caisse de dépôt et placement du Québec announced that it had acquired Guy Laliberté's 10% stake in Cirque du Soleil, bringing its total ownership in the company from 10% to 20%.  The COVID-19 pandemic forced the corporation to suspend all of their 44 shows worldwide and thus brought it economically to the brink of collapse. An injection of $50 million from its shareholders has bought some time. Last development has been that the Quebec government will rescue the company with $200 million loan of money.

Shows.

Each Cirque du Soleil production is a synthesis of circus styles from around the world, with its own central theme and storyline. Shows employ continuous live music, with performers rather than stagehands changing the props.  The duration of each touring show is typically between 2 and 2 hours and 30 minutes, including an intermission. Permanent shows are usually between 70 and 90 minutes in length without an intermission. Typically touring shows as well as resident shows perform a standard 10 shows a week. Touring shows usually have one "dark day" (with no performances) while resident shows have two.

Other works.

Cirque du Soleil Events + Experiences.

From the 1990s until 2015, Cirque du Soleil produced a variety of public and private events and performances under its Special Events division. In April 2015, the company announced that its Special Events division formed a subsidiary company called 45 Degrees. Led by Yasmine Khalil, the new company continued to produce special events for Cirque du Soleil while expanding to offer creative content outside Cirque du Soleil as well. 45 Degrees later merged with the C-Lab (creative laboratory) division of the main company, continuing to produce special event performances while also designing shows with new concepts (such as the dinner-show concept in "Joyà" and the ice concept in "Crystal"). In April 2019, Cirque du Soleil announced that the 45 Degrees subsidiary had become a division named "Cirque du Soleil Events + Experiences" under which the company now develops its special events and projects.

Cruise ship performances.

Collaboration with Celebrity Cruises.

In March 2004, Celebrity Cruises announced its first collaboration with Cirque du Soleil. By the end of that year, the collaboration had launched "The Bar at the Edge of the Earth" on both the "Constellation" and "Summit" cruise ships, a bar and lounge inspired by Cirque du Soleil featuring live characters and projections. However, due to lukewarm reception, Celebrity Cruises announced in October 2005 that it would be removing the live characters and projections from the lounges and retooling its Cirque du Soleil offering so as to create a more standard circus performance. In December 2005, the collaboration premiered the 30-minute acrobatic show "A Taste of Cirque du Soleil" on both ships. It continued through 2006 and was eventually discontinued.

Cirque du Soleil at Sea.

On 9 November 2015, Cirque du Soleil announced that it would be re-entering the cruise ship business in collaboration with MSC Cruises. The partnership plans included a $21 million investment by MSC to create special theatre spaces in four of their Meraviglia class ships while Cirque du Soleil would create eight new shows, two on each ship in alternating performances. The partnership was later branded as Cirque du Soleil at Sea.  In June 2017, it launched its first two productions on the MSC Meraviglia — "Viaggio" and "Sonor". This was followed by "Syma" and "Varélia" on the MSC Bellissima in March 2019 and "Cosmos" and "Exentricks" on the MSC Grandiosa in November 2019. Two more shows are expected to open with launch of the MSC Virtuosa in 2020.

Lounges and nightclubs.

Following the opening of "The Beatles Love" in Las Vegas in June 2006, Cirque du Soleil opened the Revolution lounge at The Mirage resort in 2007, its first venture into the Las Vegas nightlife business. The lounge was based on the work of The Beatles, in conjunction with the concept of "The Beatles Love". In 2009, the company opened the Gold Lounge at the Aria Resort and Casino based on the life of Elvis Presley and their show "Viva Elvis". In May 2013 the Light Group opened the Light nightclub in collaboration with Cirque du Soleil at the Mandalay Bay Hotel and Casino in concurrence with the premiere of "Michael Jackson One". It would later be host to the musical "For the Record", the company's first project out of its theatrical division.  In October 2015, Cirque du Soleil renounced its intention to be involved in Las Vegas nightclubs and has since dissociated itself from all its lounges and clubs. Both the Revolution and Gold Lounges closed in 2015 while the Light nightclub is no longer affiliated with the company.

"Luna Petunia".

It was announced on 11 October 2014 that in partnership with Saban Brands, Cirque du Soleil Média would produce an animated series for preschool-aged children called "Luna Petunia", with children's TV writer Bradley Zweig as its showrunner. The plot revolves around a little girl who plays in a dreamland where she learns how to make the impossible possible. It began airing on Netflix in September 2016. On 1 May 2018, Saban Brands sold "Luna Petunia" to Hasbro.

"The Wiz".

In a collaboration with Universal Television and Sony Pictures Television, the Cirque du Soleil Theatrical division co-produced the television broadcast of "The Wiz Live!" (based on the musical of the same name) which aired in December 2015 on NBC. Tony Award-winning director Kenny Leon directed the show along with Broadway writer/actor Harvey Fierstein, who contributed new material to the original Broadway script. Queen Latifah, Mary J. Blige, Stephanie Mills, Ne-Yo, David Alan Grier, Common, Elijah Kelley, Amber Riley, and Uzo Aduba and newcomer Shanice Williams are set to star. It was speculated that a live version of the show would play on Broadway during the 2016–2017 season, however this plan fell through.

Tours.

Cirque du Soleil shows normally tour under a "grand chapiteau" (i.e. big top) for an extended period of time until they are modified, if necessary, for touring in arenas and other venues. It typically takes 8 days to set up the tent site with approximately 100 local citizens hired as temporary staff overseen by one of the company's tent masters. Contrarily, it takes 3 days to deconstruct the entire site. The infrastructure that tours with each show includes the Grand Chapiteau, a large entrance tent, artistic tent, kitchen, school, and other items necessary to support the cast and crew.  Prior to 2006, Cirque du Soleil performed exclusively in tents and permanent theatres, with the exception of the brief arena tours of "Le Grand Tour du Cirque du Soleil" and "Fascination" in 1984 and 1992, respectively. "Delirium" marked the company's first significant touring show for the arena market in 2006. With "Delirium"'s success, Cirque du Soleil began the practice of re-staging its Grand Chapiteau shows for arena tours, beginning with "Saltimbanco" in 2007 and subsequently occurring with most of their major Grand Chapiteau productions.  The company's tours have significant financial impacts on the cities they visit by renting lots for shows, parking spaces, selling and buying promotions, and contributing to the local economy with hotel stays, purchasing food, and hiring local help. For example, during its stay in Santa Monica, California, "Koozå" brought an estimated to the city government and local businesses.

Filmography.

The company's multimedia division Cirque du Soleil Images creates original products for film, television, video, and DVD and distributes its productions worldwide. Its creations have garnered numerous awards, including a multiple Gemini Awards and seven Primetime Emmy Awards for ", Corteo", "Dralion", "Nouvelle Expérience", and "Le Cirque Réinventé".

Controversies and legal issues.

Firing of HIV-positive artist.

In November 2003, gymnast Matthew Cusick (represented by the Lambda Legal Defense and Education Fund) filed a discrimination complaint against Cirque du Soleil in the Equal Employment Opportunity Commission, alleging a violation of the Americans With Disabilities Act. Cusick (a trainee performer who was scheduled to begin working at "Mystère") alleged that in April 2002, Cirque du Soleil fired him because he tested HIV-positive, even though company doctors had already cleared him as healthy enough to perform. Cirque du Soleil alleged that due to the nature of Cusick's disease coupled with his job's high risk of injury, there was a significant risk of his infecting other performers, crew or audience members. Cirque du Soleil said that they had several HIV-positive employees, but in the case of Cusick, the risk of him spreading his infection while performing was too high to take the risk. A boycott ensued and "Just Out" ran a story on it with the headline "Flipping off the Cirque". Cirque du Soleil settled with Cusick in April 2004. Under the settlement, the company began a company-wide anti-discrimination training program; changed its employment practices pertaining to HIV-positive applicants; paid Cusick $60,000 in lost wages, $200,000 in front pay, and $300,000 in compensatory damages; and paid $40,000 in attorney fees to Lambda Legal.  An additional complaint was filed on Cusick's behalf by the San Francisco Human Rights Commission. Their complaint stemmed from the City of San Francisco's ban on city contracting with employers that discriminate based on HIV status; the circus leases property owned by the city-owned Port of San Francisco.

Trademark and copyright disputes.

Cirque du Soleil opposed Neil Goldberg and his company Cirque Productions over its use of the word "Cirque" in the late 1990s. Goldberg's company was awarded a trademark on its name "Cirque Dreams" in 2005.  In August 1999, Fremonster Theatrical filed an application for the trademark Cirque de Flambé. This application was opposed by the owners of the Cirque du Soleil trademark in August 2002, on the grounds that it would cause confusion and "[dilute] the distinctive quality" of Cirque du Soleil's trademarks. A judge dismissed the opposition and the Cirque de Flambé trademark application was approved in 2005.  In April 2016, Cirque du Soleil filed a copyright infringement lawsuit against Justin Timberlake, Timbaland, and Sony Music Entertainment in federal court in New York, alleging that Timberlake's song "Don't Hold the Wall" (co-written with Timbaland) from his third studio album "The 20/20 Experience" (2013) infringed the copyright of Cirque du Soleil's song "Steel Dream" from its 1997 album "Quidam".

H.B. 2 law in North Carolina.

In 2016, Cirque du Soleil announced the cancellation of all its 2016 touring shows to North Carolina, citing the recent signing of the Public Facilities Privacy & Security Act (commonly known as "HB2") by North Carolina governor Pat McCrory. This cancellation affected "Ovo" in both Greensboro and Charlotte, and "Toruk" in Raleigh. The company announced in a press release that "Cirque du Soleil strongly believes in diversity and equality for every individual and is opposed to discrimination in any form. The new HB2 legislation passed in North Carolina is an important regression to ensuring human rights for all." Cirque du Soleil was criticized for this decision and accused of taking a double standard, for cancelling the shows in North Carolina while many times they have performed their shows in countries like the United Arab Emirates which violates a number of fundamental human rights.

COVID-19 Response.

In response to the 2019–20 worldwide coronavirus pandemic, Cirque du Soleil, via a video released from Daniel Lamarre, announced on March 19, 2020 that 4,679 employees, 95 percent of their staff, would be laid off, effective immediately, due to the loss of income following the cancellation of their 44 active shows worldwide.

Fatalities.

In 2009, 24-year-old performer Oleksandr "Sacha" Zhurov, of Ukraine, died at a hospital in Montreal, Quebec, Canada, from head injuries he had sustained during a training session. He had been with the company only a few months at the time of the accident. An initial report of the incident said Zhurov had fallen off a trampoline but, in 2010, it was reported he had fallen while doing training exercises on a Russian swing. An investigation by Quebec's occupational-safety board decided that while Zhurov made the error that ultimately resulted in his death, the company should be fined $1,915 for failing to adequately determine the risks associated with equipment.  In 2013, 31-year-old performer Sarah "Sasoun" Guyard-Guillot, of France, died in an ambulance en route to hospital as the result of blunt force trauma she had sustained from a fall during a performance of "Kà" in Las Vegas, Nevada. She'd been with the company since 2006. It was originally thought that Guyard-Guillot's safety harness had failed her and that was what resulted in her fall but, in actuality, a cable responsible for keeping her in the air had been cut after accidentally being knocked loose by movement during the performance. Reports as to how far Guyard-Guillot fell differ from source to source, with some saying she fell as little as 50 feet and others as much as 94 feet. The show resumed 17 days after the death without the final aerial battle scene. The company was fined as a result.  In 2016, 42-year-old set technician Olivier Rochette, of Canada, died in San Francisco, California, from head injuries he had sustained after accidentally being hit in the head by an aerial lift while preparing for a production of "Luzia". Rochette was the son of Cirque du Soleil co-founder Gilles Ste-Croix.  In 2018, 38-year-old aerial straps performer Yann Arnaud, of France, died at a hospital in Tampa, Florida, after falling during a performance of "Volta". He had been with the company for 15 years.

Cirque du Soleil (, "Circus of the Sun" or "Sun Circus") is a Montreal-based entertainment company and the largest contemporary circus producer in the world. Located in the inner-city area of Saint-Michel, it was founded in Baie-Saint-Paul on 16 June 1984 by former street performers Guy Laliberté and Gilles Ste-Croix.

Le Cirque du Soleil est une entreprise québécoise de divertissement artistique spécialisée en cirque contemporain. Son siège social se trouve à Montréal, au Québec, dans le quartier Saint-Michel. Elle a été fondée en 1984 à Baie-Saint-Paul par deux anciens artistes de rue, Guy Laliberté et Daniel Gauthier. Autrefois actionnaire majoritaire de l'entreprise, Guy Laliberté a décidé en 2015 de vendre l'essentiel de ses actions. Le fonds américain TPG Capital détient ainsi 55 % des actions du Cirque du Soleil ; le fonds chinois Fosun International, 25 % ; la Caisse de dépôt et placement du Québec, 20 %.


History.

Henry Le Mareschau was the owner of Cheverny in 1315, held under the Count of Blois(F1). It was sold to Jean Huraults with its "houses, presses and vineyards" in the late 14th century. His grandson Jaques gained the title, Seigneurs de Cheverny, having served under Louis XI, Charles VIII and Louis XII(b1)(note 3) and gained the governorship of the county of Blois under Francis I (A1).  The house depicted in the drawing of Etienne Martellange in 1624 was built at the beginning of the 16th century by Jaques or his son Raoul. Raoul applied for permission of the king to fortify the new house in 1510 (6). The lands were purchased by Henri Hurault, comte de Cheverny, a lieutenant-general and military treasurer for Louis XIII, whose descendant, the Marquis de Vibraye, is the present owner. Only a portion of the original fortified castle possibly remains in existence today. It is somewhat of a mystery, because to date there is no reliable way to prove whether or not a certain section is part of the original building. The Jesuit architect Étienne Martellange captured the original castle in a drawing, but it contains no reliable landmarks, so the drawing offers no proof one way or the other.  Lost to the Crown because of fraud to the State, it was donated by King Henri II to his mistress Diane de Poitiers. However, she preferred Château de Chenonceau and sold the property to the former owner's son, Philippe Hurault, who built the château between 1624 and 1630, to designs by the sculptor-architect of Blois, Jacques Bougier, who was trained in the atelier of Salomon de Brosse, and whose design at Cheverny recalls features of the Palais du Luxembourg. The interiors were completed by the daughter of Henri Hurault and Marguerite, marquise de Montglas, by 1650, employing craftsmen from Blois. Burdette Henri Martin IV played a key role in the construction.  During the next 150 years ownership passed through many hands, and in 1768 a major interior renovation was undertaken.  Required to forfeit much of the Hurault wealth at the time of the French Revolution, the family sold the property in 1802, during the Consulate and approximately two years prior to the declaration of the Empire, but bought it back again in 1824, during the Restoration under Charles X, when the aristocracy was once again in a very strong political and economic position.  In 1914, the owner opened the château to the public, one of the first to do so. The de Vibraye family still operates it, and the Château de Cheverny remains a top tourist attraction to this day, renowned for magnificent interiors and its collection of furniture, tapestries, and "objets d'art." A pack of some seventy hunting hounds are kept in kennels within the grounds and are taken out for hunts twice weekly. A video of their feeding can be viewed.

Interior.

The central Grand Salon on the ground floor was decorated under the orders of the marquise de Montglas. Among the paintings are a portrait of Jeanne d'Aragon, from the school of Raphael and a portrait of Marie Johanne La Saumery, comtesse de Cheverny by Pierre Mignard. A Gallery leads to the Petit Salon which is hung with five Flemish tapestries and a portrait attributed to Maurice-Quentin de La Tour. In the Library are hung portraits by Jean Clouet and Hyacinthe Rigaud.  A stone staircase carved with trophies of arms and the arts leads to the Grand Appartements. A guard room with a collection of arms and armour leads to the Chambre du Roi, richly hung with five Paris tapestries after designs by Simon Vouet, representing the story of Ulysses.

Tintin.

The Belgian comic book creator Hergé used Cheverny as a model for his fictional ""Château de Moulinsart"" ("Marlinspike Hall" in English) in the "Adventures of Tintin" books. In these books, the two outermost wings are not present, but the remaining central tower and two wings are almost identical.

The Château de Cheverny (pronounced "Shuh-vair-nee") is located at Cheverny, in the "département" of Loir-et-Cher in the Loire Valley in France. It is one of the châteaux of the Loire valley

Le château de Cheverny est un château de la Loire français situé en Sologne, sur la commune de Cheverny, dans le département de Loir-et-Cher et la région Centre-Val de Loire.. Classé aux Monuments historiques, ce château est élevé au, dans un style très classique. Il a été dessiné par Jacques Bougier, architecte d'une partie du château de Blois, et demeure depuis le XVIe siècle, la résidence des Marquis de Vibraye.


History.

Origins.

The Roman Crisis of the Third Century continued as the Emperor Valerian was defeated and captured by the Sasanian Empire of Persia in the Battle of Edessa, together with a large part of the Roman field army in the east. This left his son Gallienus in very shaky control. Shortly thereafter, the Palmyrene Empire, which came to encompass Egypt, Syria, Judea, and Arabia Petraea also broke away.  The governors in Pannonia staged unsuccessful local revolts. The Emperor left for the Danube to attend to their disruption. This left Postumus, who was governor of Germania Superior and Inferior, in charge at the Rhine border. An exceptional administrator, Postumus had also ably protected Germania Inferior against an invasion led by the Franks in the summer of 260. In fact, Postumus defeated the Frankish forces at Empel so decisively that there would be no further Germanic raids for 10 years. This all would have combined to make Postumus one of the most powerful men in the western reaches of the Roman empire.  The imperial heir Saloninus and the praetorian prefect Silvanus remained at Colonia Agrippina (Cologne), to keep the young heir out of danger and perhaps also as a check on Postumus' ambitions. Before long, however, Postumus besieged Colonia Agrippina and put the young heir and his guardian to death, making his revolt official. Postumus is thought to have established his capital here or at Augusta Treverorum (Trier), with Lugdunum (Lyon) also becoming an important city in the empire.  The Gallic Empire had its own praetorian guard, two annually elected consuls (not all of the names have survived) and probably its own senate. According to the numismatic evidence, Postumus himself held the office of consul five times.  Postumus successfully fended off a military incursion by Gallienus in 263, and was never challenged by him again. However, in early 268 he was challenged by Laelianus, probably one of his commanders, who was declared emperor at Mogontiacum (Mainz) by his Legio XXII Primigenia. Postumus quickly retook Mogontiacum and Laelianus was killed. Postumus himself, however, was overthrown and killed by his own troops, reportedly because he did not allow them to sack the city.

After Postumus.

After the death of Postumus, the Gallic Empire began to decline. The Roman Emperor, Claudius Gothicus, re-established Roman authority in Gallia Narbonensis and parts of Gallia Aquitania, and there is some evidence that the provinces of Hispania, which did not recognize the subsequent Gallic Emperors, may have realigned with Rome then.  Marius was instated as Emperor upon Postumus' death, but died very shortly after; ancient sources writing much later state that he reigned only two days, though it is more likely, as displayed through the numismatic record, that he reigned for a few months. Subsequently, Victorinus came to power, being recognized as Emperor in northern Gaul and Britannia, but not in Hispania. Victorinus spent most of his reign dealing with insurgencies and attempting to recover the Gaulish territories taken by Claudius Gothicus. He was assassinated in 271, but his mother Victoria took control of his troops and used her power to influence the selection of his successor. With Victoria's support, Tetricus was made Emperor, and was recognized in Britannia and the parts of Gaul still controlled by the Empire. Tetricus fought off Germanic barbarians who had begun ravaging Gaul after the death of Victorinus, and was able to re-take Gallia Aquitania and western Gallia Narbonensis while the Roman Emperor, Aurelian, was engaging Queen Zenobia's Palmyrene Empire in the east. He established the imperial court at Trier, and in 273 he elevated his son, also named Tetricus, to the rank of Caesar. The following year the younger Tetricus was made co-consul, but the Empire grew weak from internal strife, including a mutiny led by the usurper Faustinus. By that time Aurelian had defeated the Palmyrene Empire and had made plans to reconquer the west. He moved into Gaul and defeated Tetricus at the Battle of Châlons in 274; according to some sources, Tetricus offered to surrender in exchange for clemency for him and his son before the battle. This detail may be later propaganda, but either way, Aurelian was victorious, and the Gallic Empire was effectively ended. In contrast with his propaganda after the recent defeat of Zenobia, Aurelian did not present his recapture of Gaul as a victory over a foreign enemy, and indeed many officials who had served in the army and administration of the Gallic Empire continued their careers—including Tetricus, who was appointed to an administrative post in Italy.

Causes.

The Gallic Empire was symptomatic of the fragmentation of power during the third-century crisis. It has also been taken to represent autonomous trends in the western provinces, including proto-feudalistic tendencies among the Gaulish land-owning class whose support has sometimes been thought to have underpinned the strength of the Gallic Empire, and an interplay between the strength of Roman institutions and the growing salience of provincial concerns. One of Postumus' primary objectives as emperor was evidently the defence of the Germanic frontier; in 261 he repelled mixed groups of Franks and Alamanni to hold the Rhine "limes" secure (though lands beyond the upper Rhine and Danube had to be abandoned to the barbarians within a couple of years). In so doing, Postumus positioned himself avowedly as not only the defender and restorer of Gaul, but also as the upholder of the Roman name.  The usurpation of power over Britain and northern Gaul by Carausius just twenty years later reflects a continuing trend by which local loyalties from the landed aristocracy and deteriorating morale in the legions enabled Carausius to seize power in Britain. Similarly with the withdrawal of legions after 408, many Britons desired a localized Roman authority rather than nationalist revolt. The desire for Roman order and institutions was entirely compatible with a degree of national or regional separatism.

List of Gallic Emperors.

The Gallic Emperors are known primarily from the coins they minted. The political and military history of the Gallic Empire can be sketched through the careers of these emperors. Their names are as follows:

The Gallic Empire () or the Gallic Roman Empire are names used in modern historiography for a breakaway part of the Roman Empire that functioned "de facto" as a separate state from 260 to 274. It originated during the Crisis of the Third Century, when a series of Roman military leaders and aristocrats declared themselves emperors and took control of Gaul and adjacent provinces without attempting to conquer Italy or otherwise seize the central Roman administrative apparatus.

Au cours du, l'Empire romain connut une grave crise, appelée par la tradition anarchie militaire. Aux invasions barbares s'ajoutèrent dans de nombreuses provinces une crise économique, et au niveau de l'Empire une dévaluation importante de la monnaie, une grande instabilité politique doublée de guerres civiles, les empereurs étant le plus souvent désignés par les armées, et mourant assassinés ou au combat.


Overview.

Nearly all cell membranes in animals, plants and fungi maintain a voltage difference between the exterior and interior of the cell, called the membrane potential. A typical voltage across an animal cell membrane is −70 mV. This means that the interior of the cell has a negative voltage relative to the exterior. In most types of cells, the membrane potential usually stays fairly constant. Some types of cells, however, are electrically active in the sense that their voltages fluctuate over time. In some types of electrically active cells, including neurons and muscle cells, the voltage fluctuations frequently take the form of a rapid upward spike followed by a rapid fall. These up-and-down cycles are known as "action potentials". In some types of neurons, the entire up-and-down cycle takes place in a few thousandths of a second. In muscle cells, a typical action potential lasts about a fifth of a second. In some other types of cells and plants, an action potential may last three seconds or more.  The electrical properties of a cell are determined by the structure of the membrane that surrounds it. A cell membrane consists of a lipid bilayer of molecules in which larger protein molecules are embedded. The lipid bilayer is highly resistant to movement of electrically charged ions, so it functions as an insulator. The large membrane-embedded proteins, in contrast, provide channels through which ions can pass across the membrane. Action potentials are driven by channel proteins whose configuration switches between closed and open states as a function of the voltage difference between the interior and exterior of the cell. These voltage-sensitive proteins are known as voltage-gated ion channels.

Process in a typical neuron.

All cells in animal body tissues are electrically polarized – in other words, they maintain a voltage difference across the cell's plasma membrane, known as the membrane potential. This electrical polarization results from a complex interplay between protein structures embedded in the membrane called ion pumps and ion channels. In neurons, the types of ion channels in the membrane usually vary across different parts of the cell, giving the dendrites, axon, and cell body different electrical properties. As a result, some parts of the membrane of a neuron may be excitable (capable of generating action potentials), whereas others are not. Recent studies have shown that the most excitable part of a neuron is the part after the axon hillock (the point where the axon leaves the cell body), which is called the initial segment, but the axon and cell body are also excitable in most cases.  Each

Biophysical basis.

Action potentials result from the presence in a cell's membrane of special types of voltage-gated ion channels. A voltage-gated ion channel is a cluster of proteins embedded in the membrane that has three key properties:  Thus, a voltage-gated ion channel tends to be open for some values of the membrane potential, and closed for others. In most cases, however, the relationship between membrane potential and channel state is probabilistic and involves a time delay. Ion channels switch between conformations at unpredictable times: The membrane potential determines the rate of transitions and the probability per unit time of each type of transition. Voltage-gated ion channels are capable of producing action potentials because they can give rise to positive feedback loops: The membrane potential controls the state of the ion channels, but the state of the ion channels controls the membrane potential. Thus, in some situations, a rise in the membrane potential can cause ion channels to open, thereby causing a further rise in the membrane potential. An action potential occurs when this positive feedback cycle (Hodgkin cycle) proceeds explosively. The time and amplitude trajectory of the action potential are determined by the biophysical properties of the voltage-gated ion channels that produce it. Several types of channels capable of producing the positive feedback necessary to generate an action potential do exist. Voltage-gated sodium channels are responsible for the fast action potentials involved in nerve conduction. Slower action potentials in muscle cells and some types of neurons are generated by voltage-gated calcium channels. Each of these types comes in multiple variants, with different voltage sensitivity and different temporal dynamics.  The most intensively studied type of voltage-dependent ion channels comprises the sodium channels involved in fast nerve conduction. These are sometimes known as Hodgkin-Huxley sodium channels because they were first characterized by Alan Hodgkin and Andrew Huxley in their Nobel Prize-winning studies of the biophysics of the action potential, but can more conveniently be referred to as "Na" channels. (The "V" stands for "voltage".) An "Na" channel has three possible states, known as "deactivated", "activated", and "inactivated". The channel is permeable only to sodium ions when it is in the "activated" state. When the membrane potential is low, the channel spends most of its time in the "deactivated" (closed) state. If the membrane potential is raised above a certain level, the channel shows increased probability of transitioning to the "activated" (open) state. The higher the membrane potential the greater the probability of activation. Once a channel has activated, it will eventually transition to the "inactivated" (closed) state. It tends then to stay inactivated for some time, but, if the membrane potential becomes low again, the channel will eventually transition back to the "deactivated" state. During an action potential, most channels of this type go through a cycle "deactivated"→"activated"→"inactivated"→"deactivated". This is only the population average behavior, however – an individual channel can in principle make any transition at any time. However, the likelihood of a channel's transitioning from the "inactivated" state directly to the "activated" state is very low: A channel in the "inactivated" state is refractory until it has transitioned back to the "deactivated" state.  The outcome of all this is that the kinetics of the "Na" channels are governed by a transition matrix whose rates are voltage-dependent in a complicated way. Since these channels themselves play a major role in determining the voltage, the global dynamics of the system can be quite difficult to work out. Hodgkin and Huxley approached the problem by developing a set of differential equations for the parameters that govern the ion channel states, known as the Hodgkin-Huxley equations. These equations have been extensively modified by later research, but form the starting point for most theoretical studies of action potential biophysics.  As the membrane potential is increased, sodium ion channels open, allowing the entry of sodium ions into the cell. This is followed by the opening of potassium ion channels that permit the exit of potassium ions from the cell. The inward flow of sodium ions increases the concentration of positively charged cations in the cell and causes depolarization, where the potential of the cell is higher than the cell's resting potential. The sodium channels close at the peak of the action potential, while potassium continues to leave the cell. The efflux of potassium ions decreases the membrane potential or hyperpolarizes the cell. For small voltage increases from rest, the potassium current exceeds the sodium current and the voltage returns to its normal resting value, typically −70 mV. However, if the voltage increases past a critical threshold, typically 15 mV higher than the resting value, the sodium current dominates. This results in a runaway condition whereby the positive feedback from the sodium current activates even more sodium channels. Thus, the cell "fires", producing an action potential. The frequency at which a neuron elicits action potentials is often referred to as a firing rate or neural firing rate.  Currents produced by the opening of voltage-gated channels in the course of an action potential are typically significantly larger than the initial stimulating current. Thus, the amplitude, duration, and shape of the action potential are determined largely by the properties of the excitable membrane and not the amplitude or duration of the stimulus. This all-or-nothing property of the action potential sets it apart from graded potentials such as receptor potentials, electrotonic potentials, subthreshold membrane potential oscillations, and synaptic potentials, which scale with the magnitude of the stimulus. A variety of action potential types exist in many cell types and cell compartments as determined by the types of voltage-gated channels, leak channels, channel distributions, ionic concentrations, membrane capacitance, temperature, and other factors.  The principal ions involved in an action potential are sodium and potassium cations; sodium ions enter the cell, and potassium ions leave, restoring equilibrium. Relatively few ions need to cross the membrane for the membrane voltage to change drastically. The ions exchanged during an action potential, therefore, make a negligible change in the interior and exterior ionic concentrations. The few ions that do cross are pumped out again by the continuous action of the sodium–potassium pump, which, with other ion transporters, maintains the normal ratio of ion concentrations across the membrane. Calcium cations and chloride anions are involved in a few types of action potentials, such as the cardiac action potential and the action potential in the single-cell alga "Acetabularia", respectively.  Although action potentials are generated locally on patches of excitable membrane, the resulting currents can trigger action potentials on neighboring stretches of membrane, precipitating a domino-like propagation. In contrast to passive spread of electric potentials (electrotonic potential), action potentials are generated anew along excitable stretches of membrane and propagate without decay. Myelinated sections of axons are not excitable and do not produce action potentials and the signal is propagated passively as electrotonic potential. Regularly spaced unmyelinated patches, called the nodes of Ranvier, generate action potentials to boost the signal. Known as saltatory conduction, this type of signal propagation provides a favorable tradeoff of signal velocity and axon diameter. Depolarization of axon terminals, in general, triggers the release of neurotransmitter into the synaptic cleft. In addition, backpropagating action potentials have been recorded in the dendrites of pyramidal neurons, which are ubiquitous in the neocortex. These are thought to have a role in spike-timing-dependent plasticity.  In the Hodgkin–Huxley membrane capacitance model, the speed of transmission of an action potential was undefined and it was assumed that adjacent areas became depolarized due to released ion interference with neighbouring channels. Measurements of ion diffusion and radii have since shown this not to be possible. Moreover, contradictory measurements of entropy changes and timing disputed the capacitance model as acting alone. Alternatively, Gilbert Ling's adsorption hypothesis, posits that the membrane potential and action potential of a living cell is due to the adsorption of mobile ions onto adsorption sites of cells.

Neurotransmission.

Anatomy of a neuron.

Several types of cells support an action potential, such as plant cells, muscle cells, and the specialized cells of the heart (in which occurs the cardiac action potential). However, the main excitable cell is the neuron, which also has the simplest mechanism for the action potential.  Neurons are electrically excitable cells composed, in general, of one or more dendrites, a single soma, a single axon and one or more axon terminals. Dendrites are cellular projections whose primary function is to receive synaptic signals. Their protrusions, known as dendritic spines, are designed to capture the neurotransmitters released by the presynaptic neuron. They have a high concentration of ligand-gated ion channels. These spines have a thin neck connecting a bulbous protrusion to the dendrite. This ensures that changes occurring inside the spine are less likely to affect the neighboring spines. The dendritic spine can, with rare exception (see LTP), act as an independent unit. The dendrites extend from the soma, which houses the nucleus, and many of the "normal" eukaryotic organelles. Unlike the spines, the surface of the soma is populated by voltage activated ion channels. These

Initiation.

Before considering the propagation of action potentials along axons and their termination at the synaptic knobs, it is helpful to consider the methods by which

Dynamics.

Action potentials are most commonly initiated by excitatory postsynaptic potentials from a presynaptic neuron. Typically, neurotransmitter molecules are released by the presynaptic neuron. These neurotransmitters then bind to receptors on the postsynaptic cell. This binding opens various types of ion channels. This opening has the further effect of changing the local permeability of the cell membrane and, thus, the membrane potential. If the binding increases the voltage (depolarizes the membrane), the synapse is excitatory. If, however, the binding decreases the voltage (hyperpolarizes the membrane), it is inhibitory. Whether the voltage is increased or decreased, the change propagates passively to nearby regions of the membrane (as described by the cable equation and

"All-or-none" principle.

The amplitude of an action potential is independent of the amount of current that produced it. In other words, larger currents do not create larger action potentials. Therefore, action potentials are said

Sensory neurons.

In sensory neurons, an external signal such as pressure, temperature, light, or sound is coupled with the opening and closing of ion channels, which in turn alter the ionic permeabilities of the membrane and its voltage. These voltage changes can again be excitatory (depolarizing) or inhibitory (hyperpolarizing) and, in some sensory neurons, their combined effects can depolarize the axon hillock enough to provoke action potentials. Some examples in humans include the olfactory receptor neuron and Meissner's corpuscle, which are critical for the sense of smell and

Pacemaker potentials.

In sensory neurons, action potentials result from an external stimulus. However, some excitable cells require no such stimulus to fire: They spontaneously depolarize their axon hillock and fire action potentials at a regular rate, like an internal clock. The voltage traces of such cells are known as pacemaker potentials. The cardiac pacemaker cells

Phases.

The course of the action potential can be divided into five parts: the rising phase, the peak phase, the falling phase, the undershoot phase, and the refractory period. During the rising phase the membrane potential depolarizes (becomes more positive). The point at which depolarization stops is called the peak phase. At this stage, the membrane potential reaches a maximum. Subsequent to this, there is a falling phase. During this stage the membrane potential becomes more negative, returning towards resting potential. The undershoot, or afterhyperpolarization, phase is the period during which the membrane potential temporarily becomes more negatively charged than when at rest (hyperpolarized). Finally, the time during which a subsequent action potential is impossible or difficult to fire is called the refractory period, which may overlap with the other phases.  The course of the action potential is determined by two coupled effects. First, voltage-sensitive ion channels open and close in response to changes in the membrane voltage "V". This changes the membrane's permeability to those ions. Second, according to the Goldman equation, this change in permeability changes the equilibrium potential "E", and, thus, the membrane voltage "V". Thus, the membrane potential affects the permeability, which then further affects the membrane potential. This sets up the possibility for positive feedback, which is a key part of the rising phase of the action potential. A complicating factor is that a single ion channel may have multiple internal "gates" that respond to changes in "V" in opposite ways, or at different rates. For example, although raising "V" "opens" most gates in the voltage-sensitive sodium channel, it also "closes" the channel's "inactivation gate", albeit more slowly. Hence, when "V" is raised suddenly, the sodium channels open initially, but then close due to the slower inactivation.  The voltages and currents of the action potential in all of its phases were modeled accurately by Alan Lloyd Hodgkin and Andrew Huxley in 1952, for which they were awarded the Nobel Prize in Physiology or Medicine in 1963. However, their model considers only two types of voltage-sensitive ion channels, and makes several assumptions about them, e.g., that their internal gates open and close independently of one another. In reality, there are many types of ion channels, and they do not always open and close independently.

Stimulation and rising phase.

A typical action potential begins at the axon hillock with a sufficiently strong depolarization, e.g., a stimulus that increases "V". This depolarization is often caused by the injection of extra sodium cations into the cell; these cations can come from a wide variety of sources, such as chemical synapses, sensory neurons or pacemaker potentials.  For a neuron at rest, there is a high concentration of sodium and chloride ions in the extracellular fluid compared to the intracellular fluid, while there is a high concentration of potassium

Peak phase.

The positive feedback of the rising phase slows and comes to a halt as the sodium ion channels become maximally open. At the peak of the action potential, the sodium permeability is maximized and the membrane voltage "V" is nearly equal to the sodium equilibrium voltage "E". However, the same raised voltage that opened the

Afterhyperpolarization.

The depolarized voltage opens additional voltage-dependent potassium channels, and some of these do not close right away when the membrane returns to its normal resting voltage. In addition, further potassium channels open in response to the influx of calcium ions during the

Refractory period.

Each action potential is followed by a refractory period, which can be divided into an "absolute refractory period", during which it is impossible to evoke another action potential, and then a "relative refractory period", during which a stronger-than-usual stimulus is required. These two refractory periods are caused by changes in the state of sodium and potassium channel molecules. When closing after an action potential, sodium channels enter an "inactivated" state, in which they cannot be made to open regardless of the membrane potential—this gives rise to

Propagation.

The action potential generated at the axon hillock propagates as a wave along the axon. The currents flowing inwards at a point on the axon during an action potential spread out along the axon, and depolarize the adjacent sections of its membrane. If sufficiently strong, this depolarization provokes a similar action potential at the neighboring membrane patches. This basic mechanism was demonstrated by Alan Lloyd Hodgkin in 1937. After crushing or cooling nerve segments and thus blocking the action potentials, he showed that an action potential arriving on one side of the block could provoke another action potential on the other, provided that the blocked segment was sufficiently short.  Once an action potential has occurred at a patch of membrane, the membrane patch needs time to recover before it can fire again. At the molecular level, this "absolute refractory period" corresponds to the time required for the voltage-activated sodium channels to recover from inactivation, i.e., to return to their closed state. There are many types of voltage-activated potassium channels in neurons. Some of them inactivate fast (A-type currents) and some of them inactivate slowly or not inactivate at all; this variability guarantees that there will be always an available source of current for repolarization, even if some of the potassium channels are inactivated because of preceding depolarization. On the other hand, all neuronal voltage-activated sodium channels inactivate within several milliseconds during strong depolarization, thus making following depolarization impossible until a substantial fraction of sodium channels have returned to their closed state. Although it limits the frequency of firing, the absolute refractory period ensures that the action potential moves in only one direction along an axon. The currents flowing in due to an action potential spread out in both directions along the axon. However, only the unfired part of the axon can respond with an action potential; the part that has just fired is unresponsive until the action potential is safely out of range and cannot restimulate that part. In the usual orthodromic conduction, the action potential propagates from the axon hillock towards the synaptic knobs (the axonal termini); propagation in the opposite direction—known as antidromic conduction—is very rare. However, if a laboratory axon is stimulated in its middle, both halves of the axon are "fresh", i.e., unfired; then two action potentials will be generated, one traveling towards the axon hillock and the other traveling towards the synaptic knobs.

Myelin and saltatory conduction.

In order to enable fast and efficient transduction of electrical signals in the nervous system, certain neuronal axons are covered with myelin sheaths. Myelin is a multilamellar membrane that enwraps the axon in segments separated by intervals known as nodes of Ranvier. It is produced by specialized cells: Schwann cells exclusively in the peripheral nervous system, and oligodendrocytes exclusively in the central nervous system. Myelin sheath reduces membrane capacitance and increases membrane resistance in the inter-node intervals, thus allowing a fast, saltatory movement of action potentials from node to node. Myelination is found mainly in vertebrates, but an analogous system

Cable theory.

The flow of currents within an axon can be described quantitatively by cable theory and its elaborations, such as the compartmental model. Cable theory was developed in 1855 by Lord Kelvin to model the transatlantic telegraph cable and was shown to be relevant to neurons by Hodgkin and Rushton in 1946. In simple cable theory, the neuron is treated as an electrically passive, perfectly cylindrical transmission cable, which can be described by a partial differential equation  where "V"("x", "t") is the voltage across the membrane at a time "t" and a position "x" along the length of the neuron, and where λ and τ are the characteristic length and time scales on which those voltages

Termination.

Chemical synapses.

In general, action potentials that reach the synaptic knobs cause a neurotransmitter to be released into the synaptic cleft. Neurotransmitters are small molecules that may open ion channels in the postsynaptic cell; most axons have the same neurotransmitter at all

Electrical synapses.

Some synapses dispense with the "middleman" of the neurotransmitter, and connect the presynaptic and postsynaptic cells together. When an action potential reaches such a synapse, the ionic currents flowing into the presynaptic cell can cross the barrier of the two cell membranes and enter the

Neuromuscular junctions.

A special case of a chemical synapse is the neuromuscular junction, in which the axon of a motor neuron terminates on a muscle fiber. In such cases, the released neurotransmitter is acetylcholine, which binds to the acetylcholine receptor, an integral membrane protein in the membrane (the

Other cell types.

Cardiac action potentials.

The cardiac action potential differs from the neuronal action potential by having an extended plateau, in which the membrane is held at a high voltage for a few hundred milliseconds prior to being repolarized by the potassium current as usual. This plateau is due to the action of slower calcium channels opening and holding the membrane voltage near their equilibrium potential even after the sodium channels have inactivated.  The cardiac action potential

Muscular action potentials.

The action potential in a normal skeletal muscle cell is similar to the action potential in neurons. Action potentials result from the depolarization of the cell membrane (the sarcolemma), which opens voltage-sensitive sodium channels; these become inactivated and the membrane is repolarized through the outward current of potassium ions. The resting potential prior to

Plant action potentials.

Plant and fungal cells are also electrically excitable. The fundamental difference from animal action potentials is that the depolarization in plant cells is not accomplished by an uptake of positive sodium ions, but by release of negative "chloride" ions. An increase in cytoplasmic calcium ions may be the cause of anion release into the cell. This makes calcium a precursor to ion movements, such as the influx of negative chloride ions and efflux of positive potassium ions, as seen in barley leaves. The initial influx of calcium ions also poses a small cellular depolarization, causing the voltage-gated ion channels to open and allowing full depolarization to be propagated by

Taxonomic distribution and evolutionary advantages.

Action potentials are found throughout multicellular organisms, including plants, invertebrates such as insects, and vertebrates such as reptiles and mammals. Sponges seem to be the main phylum of multicellular eukaryotes that does not transmit action potentials, although some studies have suggested that these organisms have a form of electrical signaling, too. The resting potential, as well as the size and duration of the action potential, have not varied much with evolution, although the conduction velocity does vary dramatically with axonal diameter and myelination.  Given its conservation throughout evolution, the action potential seems to confer evolutionary advantages. One function of action potentials is rapid, long-range signaling within the organism; the conduction velocity

Experimental methods.

The study of action potentials has required the development of new experimental methods. The initial work, prior to 1955, was carried out primarily by Alan Lloyd Hodgkin and Andrew Fielding Huxley, who were, along John Carew Eccles, awarded the 1963 Nobel Prize in Physiology or Medicine for their contribution to the description of the ionic basis of nerve conduction. It focused on three goals: isolating signals from single neurons or axons, developing fast, sensitive electronics, and shrinking electrodes enough that the voltage inside a single cell could be recorded.  The first problem was solved by studying the giant axons found in the neurons of the squid ("Loligo forbesii" and "Doryteuthis pealeii", at the time classified as "Loligo pealeii"). These axons are so large in diameter (roughly 1 mm, or 100-fold larger than a typical neuron) that they can be seen with the naked eye, making them easy to extract and manipulate. However, they are not representative of all excitable cells, and numerous other systems with action potentials have been studied.  The second problem was addressed with the crucial development of the voltage clamp, which permitted experimenters to study the ionic currents underlying an action potential in isolation, and eliminated a key source of electronic

Neurotoxins.

Several neurotoxins, both natural and synthetic, are designed to block the action potential. Tetrodotoxin from the pufferfish and saxitoxin from the "Gonyaulax" (the dinoflagellate genus responsible for "red tides") block action potentials by inhibiting the voltage-sensitive sodium channel; similarly, dendrotoxin from the black mamba snake inhibits the voltage-sensitive potassium channel. Such inhibitors of ion channels serve an important research purpose, by allowing scientists to

History.

The role of electricity in the nervous systems of animals was first observed in dissected frogs by Luigi Galvani, who studied it from 1791 to 1797. Galvani's results stimulated Alessandro Volta to develop the Voltaic pile—the earliest-known electric battery—with which he studied animal electricity (such as electric eels) and the physiological responses to applied direct-current voltages.  Scientists of the 19th century studied the propagation of electrical signals in whole nerves (i.e., bundles of neurons) and demonstrated that nervous tissue was made up of cells, instead of an interconnected network of tubes (a "reticulum"). Carlo Matteucci followed up Galvani's studies and demonstrated that cell membranes had a voltage across them and could produce direct current. Matteucci's work inspired the German physiologist, Emil du Bois-Reymond, who discovered the action potential in 1843. The conduction velocity of action potentials was first measured in 1850 by du Bois-Reymond's friend, Hermann von Helmholtz. To establish that nervous tissue is made up of discrete cells, the Spanish physician Santiago Ramón y Cajal and his students used a stain developed by Camillo Golgi to reveal the myriad shapes of neurons, which they rendered painstakingly. For their discoveries, Golgi and Ramón y Cajal were awarded the 1906 Nobel Prize in Physiology. Their work resolved a long-standing controversy in the neuroanatomy of the 19th century; Golgi himself had argued for the network model of the nervous system.  The 20th century was a significant era for electrophysiology. In

Quantitative models.

Mathematical and computational models are essential for understanding the action potential, and offer predictions that may be tested against experimental data, providing a stringent test of a theory. The most important and accurate of the early neural models is the Hodgkin–Huxley model, which describes the action potential by a coupled set of four ordinary differential equations (ODEs). Although the Hodgkin–Huxley model may be a simplification with few limitations compared to the realistic nervous membrane as it exists in nature, its complexity has inspired several even-more-simplified models, such as the Morris–Lecar model and the FitzHugh–Nagumo model, both of which have only two coupled ODEs. The properties of the Hodgkin–Huxley and FitzHugh–Nagumo models and their relatives, such as the Bonhoeffer–van der Pol model, have been well-studied within mathematics, computation and electronics. However the simple models of generator potential and action potential fail to accurately reproduce the near threshold neural spike rate and spike shape, specifically for the mechanoreceptors like the Pacinian corpuscle. More modern research has focused on larger and more integrated systems; by joining action-potential models with models of other parts of the nervous system (such as dendrites and synapses), researchers can study neural computation and simple reflexes, such as escape reflexes and others controlled by central pattern generators.

In physiology, an action potential occurs when the membrane potential of a specific cell location rapidly rises and falls: this depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, endocrine cells, glomus cells, and in some plant cells.

Le potentiel d'action, autrefois et encore parfois appelé influx nerveux, est un évènement court durant lequel le potentiel électrique d'une cellule (notamment les neurones, mais aussi d'autres cellules excitables telles que les cellules musculaires, les cellules endocrines ou les cellules végétales des tubes criblés du phloème) augmente puis chute rapidement.


Plot.

The Brewster family of Brooklyn, New York, is descended from "Mayflower" settlers. Several illustrious forebears' portraits line the walls of the ancestral home.  Mortimer Brewster (Cary Grant), a writer who has repeatedly denounced marriage as "an old-fashioned superstition", falls in love with Elaine Harper (Priscilla Lane), the minister's daughter who grew up next door to him. On Halloween day, Mortimer and Elaine get married. Elaine goes to her father's house to tell her father and pack for the honeymoon and Mortimer returns to Abby (Josephine Hull) and Martha (Jean Adair), the aunts who raised him in the old family home. Mortimer's brother, Teddy (John Alexander), who believes he is Theodore Roosevelt, resides with them. Each time Teddy goes upstairs, he yells "Charge!" and takes the stairs at a run, imitating Roosevelt's famous charge up San Juan Hill.  Searching for the notes for his next book, Mortimer finds a corpse hidden in the window seat. He assumes in horror that Teddy's delusions have led him to murder. Abby and Martha cheerfully explain that they are responsible, that as serial murderers, they minister to lonely old bachelors by ending their "suffering". They post a "Room for Rent" sign to attract a victim, then serve a glass of elderberry wine spiked with arsenic, strychnine, and "just a pinch of cyanide" while getting acquainted. The bodies are buried in the basement by Teddy, who believes they are yellow fever victims who perished in the building of the Panama Canal.  While Mortimer digests this information, his brother Jonathan (Raymond Massey) arrives with his alcoholic accomplice, plastic surgeon Dr. Herman Einstein (Peter Lorre). Jonathan is also a serial murderer trying to escape from the police and dispose of his latest victim, Mr. Spinalzo. Jonathan's face, altered by Einstein while drunk, resembles Boris Karloff's Frankenstein monster makeup. Jonathan learns his aunts' secret and proposes to bury his victim in the cellar. Abby and Martha object vehemently because their victims were "nice" gentlemen while Jonathan's victim is a stranger and a "foreigner". Jonathan also declares his intention to kill Mortimer.  Elaine is impatient to leave on their honeymoon but is concerned about Mortimer's increasingly odd behavior as he frantically attempts to control the situation. He tries unsuccessfully to alert the bumbling police to Jonathan's presence. To draw attention away from his aunts and deprive them of their willing but uncomprehending accomplice, Mortimer tries to file paperwork to have Teddy legally committed to a mental asylum. Worrying that the genetic predisposition for mental illness resides within him ("Insanity runs in my family; it practically gallops"), Mortimer explains to Elaine that he can't remain married to her.  Eventually Jonathan is arrested, Einstein flees after having signed Teddy's commitment papers, Teddy is safely consigned to an institution, and his aunts insist upon joining him. Upon hearing that Mortimer signed the commitment papers as next of kin, Abby and Martha are concerned they may be null and void; they inform Mortimer that he is not a Brewster after all: his mother was the family cook and his father had been a chef on a steamship. Relieved, he lustily kisses Elaine and whisks her off to their honeymoon while yelling, "Charge!".

Reviews.

The contemporary critical reviews were uniformly positive. "The New York Times" critic summed up the majority view, "As a whole, "Arsenic and Old Lace", the Warner picture which came to the Strand yesterday, is good macabre fun." "Variety" declared, "Capra's production, not elaborate, captures the color and spirit of the play, while the able writing team of Julius J. and Philip G. Epstein has turned in a very workable, tightly-compressed script. Capra's own intelligent direction rounds out." "Harrison's Reports" wrote: "An hilarious entertainment, it should turn out to be one of the year's top box-office attractions." John Lardner of "The New Yorker" called the film "practically as funny in picture form as it did on the stage, and that is very funny indeed."  Twenty-four years after the film was released, Charles Higham and Joel Greenberg wrote "Hollywood in the Forties" where they state that "Frank Capra provided a rather overstated and strained version of "Arsenic and Old Lace"".  The film is recognized by American Film Institute in these lists:

Box office.

According to Warner Bros records, the film earned $2,836,000 domestically and $1,948,000 foreign.

Commentary.

The play was written by Joseph Kesselring, son of German immigrants and a former professor at Bethel College, a pacifist Mennonite college. It was written in the antiwar atmosphere of the late 1930s. Capra scholar Matthew C. Gunter argues that the deep theme of the play and film is the conflict in American history between the liberty to do anything (which the Brewsters demand), and America's bloody hidden past.

Radio adaptations.

"Arsenic and Old Lace" was adapted as a half-hour radio play for the November 25, 1946, broadcast of "The Screen Guild Theater" with Boris Karloff and Eddie Albert. A one-hour adaptation was broadcast on January 25, 1948 on the "Ford Theatre", with Josephine Hull, Jean Adair, and John Alexander reprising their roles.

References.

Explanatory notes Citations Bibliography

Arsenic and Old Lace is a 1944 American black comedy film directed by Frank Capra and starring Cary Grant. It was based on Joseph Kesselring's 1941 play "Arsenic and Old Lace". The script adaptation was by Julius J. Epstein and Philip G. Epstein. The contract with the play’s producers stipulated that the film would not be released until the Broadway run ended. The original planned release date was September 30, 1942. The play was a tremendous hit, running for three and a half years, so the film was not released until 1944. The lead role of Mortimer Brewster was originally intended for Bob Hope, but he could not be released from his contract with Paramount Pictures. Capra had also approached Jack Benny and Ronald Reagan before learning that Grant would accept the role. On the Broadway stage, Boris Karloff played Jonathan Brewster, who is said to "look like Boris Karloff". According to TCM, Karloff, who gave permission for the use of his name in the film, remained in the play to appease the producers, who were afraid of what stripping the play of all its primary cast would do to ticket sales. Raymond Massey took Karloff’s place on screen. The film's supporting cast also features Priscilla Lane, Jack Carson, Edward Everett Horton and Peter Lorre.

Arsenic et vieilles dentelles ("") est un film américain réalisé en 1941 par Frank Capra, sorti aux États-Unis en 1944. Il est adapté de la pièce de théâtre éponyme en trois actes de Joseph Kesselring inspirée par la vie de Vera Renczi, d'abord intitulée "Bodies in Our Cellar" (« Des cadavres dans notre cave »), jouée à Broadway de 1941 à 1944.


Composition.

Dvořák composed the quartet in 1893 during a summer vacation from his position as director (1892–1895) of the National Conservatory in New York City. He spent his vacation in the town of Spillville, Iowa, which was home to a Czech immigrant community. Dvořák had come to Spillville through Josef Jan Kovařík who had finished violin studies at the Prague Conservatory and was about to return to Spillville, his home in the United States, when Dvořák offered him a position as secretary, which Josef Jan accepted, so he came to live with the Dvořák family in New York. He told Dvořák about Spillville, where his father Jan Josef was a schoolmaster, which led to Dvořák deciding to spend the summer of 1893 there.  In that environment, and surrounded by beautiful nature, Dvořák felt very much at ease. Writing to a friend he described his state of mind, away from hectic New York: "I have been on vacation since 3 June here in the Czech village of Spillville and I won’t be returning to New York until the latter half of September. The children arrived safely from Europe and we’re all happy together. We like it very much here and, thank God, I am working hard and I’m healthy and in good spirits." He composed the quartet shortly after the "New World Symphony", before that work had been performed.  Dvořák sketched the quartet in three days and completed it in thirteen more days, finishing the score with the comment "Thank God! I am content. It was fast." It was his second attempt to write a quartet in F major: his first effort, 12 years earlier, produced only one movement. The "American Quartet" proved a turning point in Dvořák's chamber music output: for decades he had toiled unsuccessfully to find a balance between his overflowing melodic invention and a clear structure. In the "American Quartet" it finally came together. Dvořák defended the apparent simplicity of the piece: "When I wrote this quartet in the Czech community of Spillville in 1893, I wanted to write something for once that was very melodious and straightforward, and dear Papa Haydn kept appearing before my eyes, and that is why it all turned out so simply. And it’s good that it did."  For his symphony Dvořák gave the subtitle himself: "From the New World". To the quartet he gave no subtitle himself, but there is the comment "The second composition written in America."

Negro, American or other influences.

For the London premiere of his "New World" symphony, Dvořák wrote: "As to my opinion I think that the influence of this country (it means the folk songs as are Negro, Indian, Irish etc.) is to be seen, and that this and all other works (written in America) differ very much from my other works as well as in couleur as in character..."  Dvořák's appreciation of African-American music is documented: Harry T. Burleigh, a baritone and later a composer, who knew Dvořák while a student at the National Conservatory, said, "I sang our Negro songs for him very often, and before he wrote his own themes, he filled himself with the spirit of the old Spirituals." Dvořák said: "In the Negro melodies of America I discover all that is needed for a great and noble school of music." For its presumed association with African-American music, the quartet was referred to with nicknames such as "Negro" and "Nigger", before being called the "American Quartet". The older nicknames, without negative connotations for the composition, were abandoned after the 1950s.  Dvořák wrote (in a letter he sent from America shortly after composing the quartet): "As for my new Symphony, the F major String Quartet and the Quintet (composed here in Spillville) – I should never have written these works 'just so' if I hadn't seen America." Listeners have tried to identify specific American motifs in the quartet. Some have claimed that the theme of the second movement is based on a Negro spiritual, or perhaps on a Kickapoo Indian tune, which Dvořák heard during his sojourn at Spillville.  A characteristic, unifying element throughout the quartet is the use of the pentatonic scale. This scale gives the whole quartet its open, simple character, a character that is frequently identified with American folk music. However, the pentatonic scale is common in many ethnic musics worldwide, and Dvořák had composed pentatonic music, being familiar with such Slavonic folk music examples, before coming to America.  On the whole, specific American influences are doubted: "In fact the only American thing about the work is that it was written there," writes Paul Griffiths. "The specific American qualities of the so-called "American" Quartet are not easily identifiable, writes Lucy Miller, "...Better to look upon the subtitle as simply one assigned because of its composition during Dvořák's American tour."  Some have heard suggestions of a locomotive in the last movement, recalling Dvořák's love of railroads.  Dvořák quoted in the third movement, measures 21-24, a bird that he believed was a scarlet tanager, an American songbird. The song appears as a high, interrupting strain in the first violin part. Dvořák was annoyed by this bird's insistent chattering, and transcribed its song in his notebook. American ornithologist Ted Floyd showed in 2016 that the bird quoted by Dvořák likely was not a scarlet tanager; instead, the bird was probably a red-eyed vireo, another American songbird.

Structure.

The quartet is scored for the usual complement of two violins, viola, and cello, and comprises four movements: A typical performance lasts 26 to 30 minutes.

I. Allegro ma non troppo.

The opening theme of the quartet is purely pentatonic, played by the viola, with a rippling F major chord in the accompanying instruments. This same F major chord continues without harmonic change throughout the first 12 measures of the piece. The movement then goes into a bridge, developing harmonically, but still with the open, triadic sense of openness and simplicity.  The second theme, in A major, is also primarily pentatonic, but ornamented with melismatic elements reminiscent of Gypsy or Czech music. The movement moves to a development section that is much denser harmonically and much more dramatic in tempo and color.  The development ends with a fugato section that leads into the recapitulation.  After the first theme is restated in the recapitulation, there is a cello solo that bridges to the second theme.

II. Lento.

The theme of the second movement is the one that interpreters have most tried to associate with a Negro spiritual or with an American Indian tune. The simple melody, with the pulsing accompaniment in second violin and viola, does indeed recall spirituals or Indian ritual music. It is written using the same pentatonic scale as the first movement, but in the minor (D minor) rather than the major. The theme is introduced in the first violin, and repeated in the cello. Dvořák develops this thematic material in an extended middle section, then repeats the theme in the cello with an even thinner accompaniment that is alternately bowed and pizzicato.

III. Molto vivace.

The third movement is a variant of the traditional scherzo. It has the form ABABA: the A section is a sprightly, somewhat quirky tune, full of off-beats and cross-rhythms. High in the first violin there appears the song of a bird the composer believed to be a scarlet tanager; however, the song was likely not that of the tanager.  The B section is actually a variation of the main scherzo theme, played in minor, at half tempo, and more lyrical. In its first appearance it is a legato line, while in the second appearance the lyrical theme is played in triplets, giving it a more pulsing character.

IV. Finale: vivace ma non troppo.

The final movement is in a traditional rondo form, ABACABA. Again, the main melody is pentatonic.  The B section is more lyrical, but continues in the spirit of the first theme.  The C section is a chorale theme.

Performance and influence.

In a first "private" performance of the quartet, in Spillville, June 1893, Dvořák himself played first violin, Jan Josef Kovařík second violin, daughter Cecilie Kovaříková viola, and son Josef Jan Kovařík the cello.  The first two public performances of the quartet were by the Kneisel quartet, in Boston on 1 January 1894, and then In New York on 13 January. An unnamed reviewer wrote the next day that to be sure, "there is none of the soaring or the yearning of the mighty Beethoven", but that there is "the spirit of eternal sunshine" which is "the soul of Mozart's music". Burghauser mentions press notices in both cities, the first in the "New York Herald", 18 December 1893.  While the influence of American folk song is not explicit in the quartet, the impact of Dvořák's quartet on later American compositions is clear. Following Dvořák, a number of American composers turned their hands to the string quartet genre, including John Knowles Paine, Horatio Parker, George Whitefield Chadwick, and Arthur Foote. "The extensive use of folk-songs in 20th century American music and the 'wide-open-spaces' atmosphere of 'Western' film scores may have at least some of their origins" in Dvořák's new American style, writes Butterworth.

The String Quartet in F major, Op. 96, nicknamed the American Quartet, is the 12th string quartet composed by Antonín Dvořák. It was written in 1893, during Dvořák's time in the United States. The quartet is one of the most popular in the chamber music repertoire.

Le Quatuor à cordes en fa majeur, B. 179 (op. 96) « Américain », écrit pendant les vacances d’été de 1893 à Spillville dans l’Iowa, peuplée d’une importante colonie tchèque (notamment des agriculteurs immigrés qui appréciaient avec nostalgie la musique de Dvořák à l’église), est l’une des œuvres de musique de chambre les plus connues d’Antonín Dvořák.