title: Io Shirai

text: On June 19, 2010, the Shirai sisters formed the Triple Tails stable with fellow freelancer Kana, defeating Ayumi Kurihara, Hikaru Shida and Yoshiko Tamura in their first match together at a NEO Japan Ladies Pro Wrestling event. As a result, the Shirais received a shot Kurihara's and Tamura's NEO Tag Team Championship on July 4, but were defeated by the defending champions. On August 1, Io teamed with Kana for another shot at title, but they were again defeated by Kurihara and Tamura. Triple Tails returned to its winning ways on August 29, by defeating Asami Kawasaki, Hikaru Shida and Nagisa Nozaki in a six-woman tag team match. On December 19, Triple Tails made its debut as a unit for Pro Wrestling Wave, defeating Cherry, Gami and Tomoka Nakagawa in a six-woman tag team main event.


title: Io Shirai

text: On January 29, 2011, the Shirais made their debuts for Smash, when the Triple Tails stable attacked Yusuke Kodama and Makoto after their matches, with the trio being both times chased out of the ring by Tajiri. On February 13, Triple Tails produced its first own event, where the Shirai sisters wrestled male tag team Momo no Seishun Tag (Atsushi Kotoge and Daisuke Harada) in a losing effort. On February 25, the Shirais made their Smash in-ring debuts at "Smash.14", where they teamed with Kana to defeat Ken Ohka, Tajiri and Yoshiaki Yago in an intergender six person tag team match. In March, Triple Tails took part in Osaka Pro Wrestling's Spring Samba Series, going undefeated in six person tag team matches for the duration of the tour. On April 30 at "Smash.16", Triple Tails was defeated in a six-woman tag team match by Makoto, Serena and Syuri. On May 3 at "Smash.17", the Shirai sisters were defeated in a tag team match by Hikaru Shida and Syuri. Triple Tails' second event took place on May 8 and saw Io, Mio and Kana defeat Akino, Kagetsu and Syuri in a main event six woman tag team match.


title: Io Shirai

text: On July 23, Triple Tails held a press conference to announce that, following the group's third self-produced event on September 18, Io was leaving the stable in order to pursue a singles career. On August 21, Triple Tails made its debut for Oz Academy, defeating the trio of Ayumi Kurihara, Hiren and Yumi Ohka. On September 14, Triple Tails defeated Cherry, Moeka Haruhi and Shuu Shibutani in the group's final Pro Wrestling Wave appearance. Four days later, Triple Tails defeated Dash Chisako, Ryo Mizunami and Sendai Sachiko at their third self-produced event in the group's final appearance together.


title: Io Shirai

text: In 2010, Shirai traveled to Mexico, where she entered a local wrestling school to undergo further training. On October 14, 2010, Shirai, working under the ring name Biba Kasai, made her debut for International Wrestling Revolution Group (IWRG) at an event in Naucalpan, Mexico, where she teamed with Mini Abismo Negro, Monster Clown and Yuriko to defeat El Hijo de Cien Caras, Mari Apache, Mascarita Divina and Pasión Cristal via disqualification in an eight-person tag team match. In Mexico, both Shirais worked under cat-like masks they would only wear for their entrances in Japan. On October 31, both of the Shirai sisters were brought over to AAA, which had a working relationship with IWRG, and repackaged, with Io adopting the ring name Oyuki and Mio becoming Kaguya. In their first AAA match, Oyuki and Kaguya teamed with Yuriko in a six-person tag team match, where they were defeated by Cynthia Moreno, Gato Eveready and Mari Apache. During their stay in AAA, Oyuki and Kaguya became associates of the "La Legión Extranjera" (Foreign Legion) stable. On November 7, Oyuki and Kaguya defeated Faby and Mari Apache in a tag team match and afterwards stole Faby's AAA World Mixed Tag Team Championship and Mari's AAA Reina de Reinas Championship belts. On November 15, the Apaches and Cynthia Moreno defeated Oyuki, Kaguya and Sexy Star in a six-woman tag team match. A week later, Oyuki, Kaguya and Jennifer Blake defeated Moreno and the Apaches in another six woman tag team match. This would turn out to be Oyuki's and Kaguya's final AAA appearance, which resulted in the storyline with the Apaches being dropped without a conclusion.


title: Io Shirai

text: Shirai, now working without her mask and under the ring name Io Shirai, returned to Mexico on May 15, 2011, at "Lucha Fan Fest 4", where she teamed with Nosawa to defeat Chica Tormenta and Mike Segura for the vacant Americas World Mixed Tag Team Championship. In November 2011, Shirai returned to Mexico with Wrestling All-Star Pros (WASP) for another two-week tour. On November 1, Shirai put her hair on the line in her first "Lucha de Apuestas" Hair vs. Mask match, a four-way intergender elimination match, where she faced Ángel o Demonio, La Maléfica and Shitara. Eventually, the match came down to Shirai and La Maléfica, ending with Shirai submitting her opponent for the win, forcing her to unmask herself. Shirai and Nosawa defended the Americas World Mixed Tag Team Championship back in Japan on January 3, 2012, defeating Ken Ohka and Mio Shirai at a Union Pro Wrestling event. Shirai returned to Mexico on May 19, 2012, to take part in Lucha Expo in Mexico City, where she teamed with Keira to defeat Chica Tormenta and La Vaquerita in a tag team match.


title: Io Shirai

text: Upon Shirai's return to Japan, she was arrested under suspicion of marijuana smuggling. This resulted in a two-year break from her regular trips to Mexico, before, on January 27, 2014, Shirai announced her return to the country. Shirai returned to Mexico on May 11 to take part in Toryumon Mexico's "DragonMania 9" event, where she, Dark Angel, Kairi Hojo and Mayu Iwatani defeated Ahy Lyyn, Baby Star, Diosa Atenea and Mystique in an eight-woman tag team match. On May 23, 2015, Shirai returned to Mexico, first taking part in Toryumon Mexico's "DragonMania 10" event in Arena México, where she, Diosa Atenea, Mayu Iwatani and Mima Shimoda defeated India Mazahua, India Sioux, Maligna and Xena in an eight-woman tag team match. Later that same day, Shirai also took part in "Lucha Fan Fest 8", where she, Dos Caras and Vanely defeated Atenea, Iwatani and Brazo de Plata in a six-person tag team match.


title: Io Shirai

text: After leaving Triple Tails, Shirai, though still billed as a freelancer, effectively made World Wonder Ring Stardom her new home promotion, making her debut on August 14, 2011, when she teamed with Nanae Takahashi to defeat Yoko Bito and Yuzuki Aikawa in a tag team match, pinning Aikawa and afterwards challenging her to a match for the Wonder of Stardom Championship. Shirai continued to team with Takahashi the following month, before unsuccessfully challenging Aikawa for the Wonder of Stardom Championship on September 25. On October 10, Shirai and Takahashi entered the Goddesses of Stardom Tag League. When the tournament concluded two weeks later, Shirai and Takahashi finished with a record of one win and two losses and did not advance in the tournament. In January 2012, Shirai formed the Planet stable with Arisa Hoshiki, Mayu Iwatani and Natsumi Showzuki. On March 4, Shirai produced her own independent event named "Carino!", which celebrated her fifth anniversary in professional wrestling and during which she officially aligned herself with Stardom, ending her freelancing days. In the main event of the show, Shirai teamed with Dark Angel, whom she had befriended during her time in Mexico, to defeat Miho Wakizawa and Nanae Takahashi in a tag team match. On March 25, Shirai unsuccessfully challenged Natsuki☆Taiyo for the High Speed Championship. On April 22, Shirai, Arisa Hoshiki and Natsumi Showzuki of the Planet stable made it to the finals of a six-woman tag team tournament, set to determine the number one stable in Stardom, however, there they were defeated by Nanae Gundan (Miho Wakizawa, Nanae Takahashi and Yuuri Haruka).


title: Io Shirai

text: Following her May 2012 drug arrest and eventual acquittal, Shirai made her in-ring return on July 22, taking part in a Stardom Rumble to determine the final four participants in the 5★Star GP2012 tournament. Shirai scored the last elimination of the match, pinning Planet stablemate Mayu Iwatani to qualify for the tournament. Shirai finished the tournament, held from August 19 to September 30, with two wins, one draw and one loss, failing to advance to the finals. On October 27, Shirai and Mayu Iwatani entered the 2012 Goddesses of Stardom Tag League under the team name "Thunder Rock", defeating previous year's finalists, Kawasaki Katsushika Saikyou Densetsu (Natsuki☆Taiyo and Yoshiko) in their opening round-robin match. However, after losing their two remaining round-robin matches, Shirai and Iwatani failed to qualify for the finals of the tournament. Shirai finished her 2012 by losing to Kyoko Kimura on December 24 in a match, where the winner would earn the right to challenge for any of Stardom's titles. On January 14, 2013, Shirai, along with Planet stablemates Mayu Iwatani and Natsumi Showzuki, entered a tournament to determine the inaugural Artist of Stardom Champions. They were, however, eliminated in their first round match by Team Shimmer (Kellie Skater, Portia Perez and Tomoka Nakagawa). Six days later, Shirai and Iwatani unsuccessfully challenged Kawasaki Katsushika Saikyou Densetsu (Natsuki☆Taiyo and Yoshiko) for the Goddess of Stardom Championship.


title: Io Shirai

text: On March 24, 2013, Shirai first defeated Kaori Yoneyama in the semi-finals and then Dark Angel in the finals to become the number one contender to the World of Stardom Championship at the biggest event in Stardom's history on April 29 at Ryōgoku Kokugikan. Shirai faced off with the reigning World of Stardom Champion, Alpha Female, for the first time on March 31, when she and Dark Angel were defeated in a tag team match by Kyoko Kimura and the champion, who pinned Shirai for a decisive win. On April 29 at "Ryōgoku Cinderella", Shirai defeated Alpha Female to become the third World of Stardom Champion. Shirai made her first successful title defense on June 2 against Yoshiko. On August 17, Shirai defeated Kyoko Kimura for her second successful title defense. From August 25 to September 23, Shirai took part in 5★Star GP2013, where she finished with a record of three wins, one draw and one loss, with a draw on the final day against rookie Takumi Iroha costing her a spot in the finals. Shirai and Iroha then teamed up for the 2013 Goddesses of Stardom Tag Tournament, but were eliminated in their first round match on October 20 by Kairi Hojo and Nanae Takahashi, the winner of the 5★Star GP2013 who was now eyeing a shot at Shirai's World of Stardom Championship. The title match between Shirai and Takahashi took place on November 4 at Stardom's 100th event, where Shirai was victorious with only one second remaining in the thirty-minute time limit, making her third successful title defense. Post-match, Shirai offered the next shot at her title to JWP Joshi Puroresu wrestler Arisa Nakajima. Nakajima accepted the match on the condition that she could first regain the JWP Openweight Championship. On December 16, the day after Nakajima had regained the title, a title match between Shirai and Nakajima for both the World of Stardom and JWP Openweight Championships was made official for December 29. The match ended in a thirty-minute time limit draw, meaning that both champions retained their titles. Post-match, Shirai was challenged to another double title match by new High Speed Champion Natsuki☆Taiyo. At Stardom's annual awards ceremony later that same day, Shirai was named the promotion's MVP of 2013.


title: Io Shirai

text: On January 26, 2014, at Stardom's third anniversary event, Shirai defeated High Speed Champion Natsuki☆Taiyo in a match, where only the World of Stardom Championship was on the line, to make her fifth successful title defense. Nearing the one-year anniversary of her World of Stardom Championship win, Shirai vowed to break Nanae Takahashi's records for both the longest reign (602 days) and most successful title defenses (seven), while also announcing she was accepting challengers from all over the world. Shirai made her sixth successful title defense against American wrestler Melissa on March 16, and the record-tying seventh successful defense against previous champion Alpha Female on April 29. On May 6, Shirai became a double champion in Stardom, when she defeated the soon-to-retire Natsuki☆Taiyo for the High Speed Championship. On May 17, Shirai made her record-setting eighth successful defense of the World of Stardom Championship by defeating Star Fire at Lucha Fan Fest 7 in Mexico City. Upon her return to Stardom, Shirai made her ninth successful title defense against Takumi Iroha on June 1. Afterwards, she offered the next title shot to Meiko Satomura, who had defeated her in a non-title match at a Sendai Girls' Pro Wrestling event on April 26. On July 10, Shirai defeated Satomura for her tenth successful defense of the World of Stardom Championship. On July 20, Shirai got an opportunity to become Stardom's first Triple Crown Champion, but she and Takumi Iroha, billed collectively as "Heisei Star", failed in their attempt to capture the Goddess of Stardom Championship from Kimura Monster-gun (Alpha Female and Kyoko Kimura). On August 10, Shirai lost the World of Stardom Championship to Yoshiko, ending her reign at 468 days and ten successful defenses.


title: Io Shirai

text: After their World of Stardom Championship match against each other, Shirai and Yoshiko agreed to form a new partnership, which was also joined by Mayu Iwatani, Reo Hazuki and Takumi Iroha. The five, all born during the Heisei period, started a new rivalry with Stardom's older Shōwa period-born wrestlers, led by Nanae Takahashi. From August 24 to September 23, Shirai took part in the 2014 5★Star GP. After three wins and two losses, Shirai advanced to the finals, where she defeated Yoshiko to win the tournament. On November 3, Shirai and Yoshiko, whose partnership was now officially known as "Heisei-gun" ("Heisei Army"), unsuccessfully challenged Shōwa-gun's Kairi Hojo and Nanae Takahashi for the Goddess of Stardom Championship. Later that month, Shirai and Mayu Iwatani made it to the finals of the 2014 Goddesses of Stardom Tag League, but were defeated there by Hojo and Takahashi. On November 24, Shirai made her first successful defense of the High Speed Championship against Shōwa-gun's Koguma. On December 7, Shirai once again became a double champion, when she and Heisei-gun stablemates Mayu Iwatani and Takumi Iroha defeated Tomodachi Mania (Hatsuhinode Kamen, Kaori Yoneyama and Tsubasa Kuragaki) to win the Artist of Stardom Championship. On February 14, Shirai took part in her sister Mio's independent M.I.O event, defeating Mio in a main event singles match, which marked their first match together in three years. On February 22, Shirai lost the High Speed Championship to Koguma in her third defense. On March 29, following Yoshiko's suspension from Stardom, Shirai was entered into a four-woman tournament to determine the new World of Stardom Champion. After defeating Takumi Iroha, she advanced to the finals of the tournament, where she was defeated by Kairi Hojo. On April 14, Heisei-gun was stripped of the Artist of Stardom Championship due to Iroha being sidelined with a knee injury. On May 6, Shirai and Iwatani first defeated Oedo Tai (Kris Wolf and Star Fire) and then Candy Crush (Chelsea and Kairi Hojo) to win a tournament for the vacant Goddess of Stardom Championship. On May 17, Shirai defeated Nikki Storm in a decision match to win the vacant Wonder of Stardom Championship, becoming the first wrestler to have held all five of Stardom's championships.


title: Io Shirai

text: Ahead of Mio Shirai's impending retirement from professional wrestling, she made her Stardom debut on July 26 to wrestle what was billed as the Shirai sisters' final match together, where Io and Mio defeated Hiroyo Matsumoto and Mayu Iwatani. On September 23, Shirai and Iwatani broke the record for most successful defenses of the Goddess of Stardom Championship by defeating Dash Chisako and Sendai Sachiko for their fourth defense. On October 17, Shirai defeated Mia Yim in Covina, California, during Stardom's first American tour, to make her sixth successful defense of the Wonder of Stardom Championship. During the second event in Baldwin Park, California two days later, Shirai and Iwatani made their fifth successful defense of the Goddess of Stardom Championship against Hiroyo Matsumoto and Kellie Skater. On November 8, Shirai and Iwatani won the 2015 Goddesses of Stardom Tag Tournament, defeating Alex Lee and Kaori Yoneyama in the first round and Hiroyo Matsumoto and Santana Garrett in the final match, which also marked their sixth successful defense of the Goddess of Stardom Championship. After seven successful title defenses, Shirai lost the Wonder of Stardom Championship to Santana Garrett on November 23 in a match also contested for Garrett's NWA World Women's Championship. On December 7, "Tokyo Sports" voted Shirai the "joshi" wrestler of the year over Kairi Hojo, Meiko Satomura and Saki Akai.


title: Io Shirai

text: On December 23, Shirai defeated Meiko Satomura to become the first two-time World of Stardom Champion. Meanwhile, Thunder Rock also continued their reign as the Goddess of Stardom Champions, defeating the rookie team of Jungle Kyona and Momo Watanabe on January 10, 2016, for their seventh successful title defense. On January 17, Shirai made her first successful defense of the World of Stardom Championship against Kairi Hojo. On February 28, Shirai became a triple champion, when she, Iwatani and Kairi Hojo, billed collectively as "Threedom" (a combination of the words "Three" and "Stardom"), defeated Evie, Hiroyo Matsumoto and Kellie Skater to win the Artist of Stardom Championship. In April, Shirai, along with Iwatani and Hojo, traveled to the United States to take part in events held by Lucha Underground and Vendetta Pro Wrestling. On May 15, Thunder Rock faced off in a match, where Shirai defeated Iwatani to make her fourth successful defense of the World of Stardom Championship. Later in the month, Stardom wrestlers took part in a European tour, during which the promotion debuted the new Stardom World Association (SWA) World Championship. On May 21, Shirai first defeated Kay Lee Ray in the first round, then Dragonita in the semi-finals and finally Toni Storm in the finals to win the tournament and become the inaugural champion. After setting records for both the longest reign and most successful title defenses, Shirai and Iwatani lost the Goddess of Stardom Championship to Kagetsu and Kyoko Kimura in their 11th title defense on June 16. On July 24, Shirai lost the SWA World Championship to Toni Storm in her third defense. The following day, Shirai announced she was undergoing a tailbone surgery, but was only expected to miss one month of in-ring action. On October 2, Threedom lost the Artist of Stardom Championship to Oedo Tai (Hana Kimura, Kagetsu and Kyoko Kimura) in their third defense. On November 11, Thunder Rock made it to the finals of the 2016 Goddesses of Stardom Tag League. After losing to Kairi Hojo and Yoko Bito, Shirai turned on Iwatani, declared that Thunder Rock and Threedom were history and announced a new partnership with an unidentified masked woman.


title: Io Shirai

text: On November 20, Shirai and her new partner, now revealed as the former Reo Hazuki and renamed "HZK", were joined by Momo Watanabe, who turned on Mayu Iwatani during a tag team match. The Shirai led new stable was later dubbed "Queen's Quest". On December 14, Shirai was awarded her second consecutive "joshi" wrestler of the year award by "Tokyo Sports". Shirai closed her year by making her ninth successful defense of the World of Stardom Championship against former tag team partner Mayu Iwatani on December 22. On January 7, 2017, Queen's Quest became the new Artist of Stardom Champions by defeating Oedo Tai (Kagetsu, Kyoko Kimura and Viper) for the vacant title. On February 11, after Momo Watanabe had been sidelined with an injury, Azumi became the newest member of Queen's Quest, adopting the ring name "AZM". On February 23, Shirai made her eleventh successful defense of the World of Stardom Championship against Shayna Baszler, breaking her own record for most defenses of the title. On March 9, Shirai celebrated her tenth anniversary in professional wrestling with a special event, which saw her team with Meiko Satomura to defeat Chihiro Hashimoto and Mayu Iwatani in a main event tag team match. On April 9, Queen's Quest was stripped of the Artist of Stardom Championship due to Watanabe's injury. Queen's Quest, now represented by Shirai, AZM and HZK, regained the title six days later by defeating Oedo Tai (Hana Kimura, Kagetsu and Rosa Negra) in the finals of a four-team tournament. They lost the title to Hiromi Mimura, Kairi Hojo and Konami in their first defense on May 6, only to regain it on June 4. They lost the title to Team Jungle (Hiroyo Matsumoto, Jungle Kyona and Kaori Yoneyama) in their first defense on June 17. After a reign of 18 months with a record 14 successful title defenses, Shirai lost the World of Stardom Championship to Wonder of Stardom Champion Mayu Iwatani on June 21. The following day, Shirai announced that she was going on an indefinite hiatus to undergo treatment for a neck injury. She had suffered the injury taking a piledriver from Toni Storm during their World of Stardom Championship match on May 14.


title: Io Shirai

text: Shirai returned from her injury on July 30, offering Oedo Tai member Viper a membership in Queen's Quest. After Viper accepted the offer, Shirai vowed to regain the Artist of Stardom Championship and win the 2017 5★Star GP. Shirai's return match took place on August 13, when she, HZK and Viper regained the Artist of Stardom Championship from Matsumoto, Kyona and Yoneyama. On November 19, Shirai defeated Yoko Bito to win the Wonder of Stardom Championship for the second time. On December 14, Shirai became the first wrestler in history to win three consecutive female wrestler of the year awards from "Tokyo Sports". On April 21, 2018, Shirai made her tenth successful defense of the Wonder of Stardom Championship against Martina, breaking Santana Garrett's record for most defenses of the title. On May 23, Shirai lost the Wonder of Stardom Championship to Momo Watanabe in her twelfth title defense. On May 29, 2018, Stardom announced Shirai's departure after her last match on June 10. Shirai wrestled her final matches for Stardom on June 10 taking part of a ten-match one-minute time limit series against members of the Stardom roster that ended in one win and one loss.


title: Io Shirai

text: In October 2016, the "Wrestling Observer Newsletter" reported that both Shirai and Kairi Hojo had been contacted and offered WWE contracts, starting in 2017. Reportedly, Shirai had informed Stardom's management that she was taking the offer. In March 2017, Shirai took part in a WWE tryout at the WWE Performance Center in Orlando, Florida. Her tryout was not supposed to go public, but due to a communications issue, she was featured on WWE's official website in an article that was taken down shortly afterwards. After the tryout, Shirai confirmed that she had been offered a contract.


title: Io Shirai

text: On May 15, 2017, Dave Meltzer of the "Wrestling Observer Newsletter" reported that Shirai had accepted the contract offer from WWE. The following month, it was reported that a WWE medical examination had discovered a neck injury that would delay Shirai's WWE debut. In August, Meltzer reported that just as doctors had cleared Shirai to return to the ring, WWE had rescinded their contract offer, noting the company had a "general rule of not wanting to bring in new talent that either has concussion issues or neck issues". It was later reported that the medical examination had also found an issue with Shirai's heart. Japanese doctors had cleared Shirai for both her heart and neck, but WWE doctors suggested passing on signing her. Six months later on May 28, 2018, "Tokyo Sports" reported that Shirai was in discussions with WWE. On May 29, Shirai announced she would be leaving Stardom.


title: Io Shirai

text: Shirai made her first official appearance for the promotion on June 30, 2018, at the WWE house show in Ryōgoku Kokugikan, where it was announced she had signed with the promotion and would be competing in their developmental territory, NXT. In July, it was announced that Shirai would participate in the second Mae Young Classic tournament. On August 8, Shirai defeated Xia Brookside in the tournament's first round in her WWE debut match. The following day, on August 9, Shirai defeated Zeuxis in the second round, Deonna Purrazzo in the quarterfinals and Rhea Ripley in the semi–finals to advance to the finals of the tournament, that took place at WWE Evolution, on October 28, where Shirai was defeated by Toni Storm.


title: Io Shirai

text: In her first appearance for "NXT", Shirai debuted on November 17, 2018 at where she and Dakota Kai saved her best friend Kairi Sane during her match with Shayna Baszler from an assault by her allies Jessamyn Duke and Marina Shafir. She made her debut match on the December 19 episode of "NXT", where she teamed with Kai and they defeated Duke and Shafir in a tag team match, and because of her win, a week later, Shirai competed in a fatal four-way match to determine the number one contender for the NXT Women's Championship, however, the match was won by Bianca Belair. Shortly after, with Kai sidelined with an injury, Shirai continued to team with Sane, forming a tag team known as "The Sky Pirates" while continuing to defeat various teams.


title: Io Shirai

text: On April 5, 2019, at , Shirai and Sane took part in a fatal four-way match for the NXT Women's Championship, however, both were unsuccessful in capturing the title as Baszler submitted Bianca Belair to retain the title. Just six days later on April 11 (episode aired on tape delay on April 17), Shirai interfered in Sane's rematch with Baszler and attacked her as she was looking to injure Sane, resulting in a disqualification loss for Sane. As a result, Sane was not allowed to challenge for the NXT Women's Championship anymore, which was a way to write her off the brand.


title: Io Shirai

text: Following Sane's move to the main roster, and the disbanding of The Sky Pirates, Shirai continued her feud with Baszler, Duke and Shafir as the three continuously attacked her. This ultimately led to a title match between Shirai and Baszler for the NXT Women's Championship at on June 1, 2019. At the event, Shirai was unsuccessful in defeating Baszler, despite Candice LeRae's interference and attack on Duke and Shafir. A few weeks later, on the June 26 episode of "NXT", Shirai received a rematch against Baszler in a steel cage match, however, she once again failed to capture the title. After the match, Shirai attacked LeRae (who once again took out Duke and Shafir) herself, turning heel. In the summer, Shirai developed a new image, using a new entrance theme and wearing black leather and continued her rivalry with LeRae. The storyline between the two culminated in a match at on August 10, which Shirai won via submission.


title: Io Shirai

text: In November, Shirai was announced as one of the participants in the first-ever women's WarGames match as part of Shayna Baszler's team who was feuding with Rhea Ripley. At , Baszler's team lost to Ripley and Candice LeRae, despite having a 2-on-4 handicap advantage. The next night at Survivor Series, Shirai competed as part of Team NXT, in the first-ever 5-on-5-on-5 Women's Survivor Series match, where her team won and she was one of the survivors. During a match against Toni Storm on the January 22, 2020, episode of "NXT", Shirai suffered a minor injury that kept her out of action for two months.


title: Io Shirai

text: Shirai returned on the March 25 episode of "NXT", defeating Aliyah and also qualifying for a number one contender's ladder match. On the April 8 episode of "NXT", Shirai won the ladder match for an opportunity against the new NXT Women's Champion Charlotte Flair. She received her title match on the May 6 episode of "NXT", which she won via disqualification when Flair attacked her with a kendo stick. Throughout May, Shirai entered a storyline with both Flair and Ripley (whom Flair defeated to win the title at WrestleMania 36), which led to a triple threat match at . At the event, on June 7, Shirai defeated both Flair and Ripley to win the NXT Women's Championship, marking her first title win in WWE. Shirai defeated Sasha Banks in a non-title match at special episode of "NXT". During the summer, Shirai slowly transitioned into a tweener and successfully defended her title against Tegan Nox and Dakota Kai at TakeOver XXX. In September, Shirai renewed her rivalry with Candice LeRae. Their feud sparked two title matches at TakeOver 31 and , including the first ever tables, ladders and scares match, in which Shirai was able to retain her title. On November 18 episode of "NXT", Shirai successfully retained her title against Rhea Ripley. At , Shirai was a part of Team Blackheart (herself, Shotzi Blackheart, Rhea Ripley and Ember Moon) who faced Team Lerae (Candice LeRae, Toni Storm, Dakota Kai and Raquel González) in a losing effort in which Shirai was pinned by González. On February 14, 2021, at Shirai defeated Mercedes Martinez and Toni Storm in a triple threat match to retain the NXT Women's Championship. On the March 10, episode of "NXT", Shirai was challenged by Storm for the title, which she retained. On April 7 in the main event of Night 1 of , she lost the title to Raquel González, ending her reign at 304 days.


title: Io Shirai

text: Shirai made her return on the June 8 episode of "NXT". In the following weeks, Shirai allied with Zoey Stark as a tag team. On the June 29 episode of "NXT", they won a triple threat match to become the number one contenders for the NXT Women's Tag Team Championship. At , Shirai and Stark defeated The Way (Candice LeRae and Indi Hartwell) to win the titles. On the September 7 episode of "NXT", they defended their championship in a title match against the team of Kacy Catanzaro and Kayden Carter. They successfully retained their titles in a match against the Toxic Attraction (Gigi Dolin and Jacy Jayne) on the September 28 episode of "NXT". At , in a triple threat Scareway to Hell Ladder match against the Toxic Attraction and the team of Indi Hartwell and Persia Pirotta, they lost to Toxic Attraction, ending their reign at 111 days.


title: Io Shirai

text: At WarGames, Shirai teamed with Cora Jade, Kay Lee Ray, and Raquel González. They defeated the team of Dakota Kai and Toxic Attraction in a WarGames match. In 2022, Shirai allied with Kay Lee Ray after saving the latter from Toxic Attraction's attack. As a tag team, they then entered Women's Dusty Rhodes Tag Team Classic. They defeated the team of Amari Miller and Lash Legend in the first round, Kacy Catanzaro and Kayden Carter in the semi-finals, Wendy Choo and Dakota Kai in the finals and won Women's Dusty Cup. Shirai and Ray then decided to challenge Mandy Rose for NXT Women's Championship at Stand & Deliver instead of challenging tag team champions Dolin and Jayne. They were unsuccessful in winning the title. Then she was out of action with an injury.


title: Io Shirai

text: On July 30, 2022, Shirai made her return from injury at SummerSlam alongside Bayley and Dakota Kai, with the three being allies and confronting Raw Women's Champion Bianca Belair. Shirai was presented under the new ring name Iyo Sky and joined the Raw brand as a heel. On the following episode of "Raw", the trio targeted and attacked Becky Lynch, Alexa Bliss, and Asuka. Sky's debut match was against Belair in a non-title match resulting in no-contest due to interference from Asuka, Bliss, Kai, and Bayley entering the ring and starting a fight. In the following week, the trio challenged Asuka, Belair, and Bliss for a six-woman tag team match at Clash at the Castle. Sky and Kai then participated in Women's Tag Team Championship Tournament and won the first round and semi-finals but they were unsuccessful in winning the finals and WWE Women's Tag Team Championship. At Clash at the Castle, the stable of Sky, Bayley, and Kai was named as Damage CTRL and they won their match. On the September 12 episode of "Raw", Sky and Kai defeated Women's Tag Team Champions Aliyah and Raquel Rodriguez in a rematch to win the championship. On the October 31 episode of "Raw", they lost their title to the team of Asuka and Bliss. Sky and Kai then reclaimed the titles at Crown Jewel in a rematch.


title: Io Shirai

text: Shirai noted that her professional wrestling persona is inspired by Rey Mysterio. In 2016, Dave Meltzer of the "Wrestling Observer Newsletter" referred to Shirai and her fellow Japanese wrestlers Kairi Hojo and Mayu Iwatani as "three of the best wrestlers in the world".


title: Io Shirai

text: In March 2017, Odate was featured in a "gravure" spread on the "Weekly Playboy" magazine. Odate made her video game debut as a playable character in "WWE 2K20", and subsequently in "WWE 2K22".


title: Io Shirai

text: Odate was previously in a relationship with fellow professional wrestler Kazushige Nosawa; the two lived together in Koto, Tokyo. She is a fan of Hiroshi Tanahashi and Momoiro Clover Z.


title: Io Shirai

text: On May 23, 2012, Odate and Nosawa were arrested at the Narita International Airport in Narita, Chiba upon their return from Mexico under suspicion of trying to smuggle 75 grams of marijuana, hidden inside paintings of the two, into the country. Both Odate and Nosawa denied the charges, claiming that the paintings were gifts from fans. Odate was released from a detention center on June 12. On June 21, Odate held a press conference, publicly apologizing to her fans, employers and co-workers, while again denying the charges. Odate also revealed that she had not considered retirement, but wanted to work again and regain the trust of her peers and fans, while also revealing that she and Nosawa had ended their relationship. On June 28, Japan's public prosecutor's office decided not to prosecute Odate over the incident. On July 9, Mexico based Japanese wrestler Takuya Sugi held a press conference and confessed to planting the drugs on Shirai and Nosawa. According to Sugi, Masahiro Hayashi, who worked as a liaison between AAA and Japan and who had a personal grudge with Nosawa, had promised him a contract extension with AAA in exchange for the deed.


title: Lysine

text: Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. It contains an α-amino group (which is in the protonated form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO form under biological conditions), and a side chain lysyl ((CH)NH), classifying it as a basic, charged (at physiological pH), aliphatic amino acid. It is encoded by the codons AAA and AAG. Like almost all other amino acids, the α-carbon is chiral and lysine may refer to either enantiomer or a racemic mixture of both. For the purpose of this article, lysine will refer to the biologically active enantiomer -lysine, where the α-carbon is in the "S" configuration.


title: Lysine

text: The human body cannot synthesize lysine. It is essential in humans and must therefore be obtained from the diet. In organisms that synthesise lysine, two main biosynthetic pathways exist, the diaminopimelate and α-aminoadipate pathways, which employ distinct enzymes and substrates and are found in diverse organisms. Lysine catabolism occurs through one of several pathways, the most common of which is the saccharopine pathway.


title: Lysine

text: Lysine plays several roles in humans, most importantly proteinogenesis, but also in the crosslinking of collagen polypeptides, uptake of essential mineral nutrients, and in the production of carnitine, which is key in fatty acid metabolism. Lysine is also often involved in histone modifications, and thus, impacts the epigenome. The ε-amino group often participates in hydrogen bonding and as a general base in catalysis. The ε-ammonium group () is attached to the fourth carbon from the α-carbon, which is attached to the carboxyl (C=OOH) group.


title: Lysine

text: Due to its importance in several biological processes, a lack of lysine can lead to several disease states including defective connective tissues, impaired fatty acid metabolism, anaemia, and systemic protein-energy deficiency. In contrast, an overabundance of lysine, caused by ineffective catabolism, can cause severe neurological disorders.


title: Lysine

text: Lysine was first isolated by the German biological chemist Ferdinand Heinrich Edmund Drechsel in 1889 from the protein casein in milk. He named it ""lysin"". In 1902, the German chemists Emil Fischer and Fritz Weigert determined lysine's chemical structure by synthesizing it.


title: Lysine

text: Two pathways have been identified in nature for the synthesis of lysine. The diaminopimelate (DAP) pathway belongs to the aspartate derived biosynthetic family, which is also involved in the synthesis of threonine, methionine and isoleucine. Whereas the α-aminoadipate (AAA) pathway is part of the glutamate biosynthetic family.


title: Lysine

text: The DAP pathway is found in both prokaryotes and plants and begins with the dihydrodipicolinate synthase (DHDPS) (E.C 4.3.3.7) catalysed condensation reaction between the aspartate derived, -aspartate semialdehyde, and pyruvate to form (4"S")-4-hydroxy-2,3,4,5-tetrahydro-(2"S")-dipicolinic acid (HTPA). The product is then reduced by dihydrodipicolinate reductase (DHDPR) (E.C 1.3.1.26), with NAD(P)H as a proton donor, to yield 2,3,4,5-tetrahydrodipicolinate (THDP). From this point on, four pathway variations have been found, namely the acetylase, aminotransferase, dehydrogenase, and succinylase pathways. Both the acetylase and succinylase variant pathways use four enzyme catalysed steps, the aminotransferase pathway uses two enzymes, and the dehydrogenase pathway uses a single enzyme. These four variant pathways converge at the formation of the penultimate product, "meso"‑diaminopimelate, which is subsequently enzymatically decarboxylated in an irreversible reaction catalysed by diaminopimelate decarboxylase (DAPDC) (E.C 4.1.1.20) to produce -lysine. The DAP pathway is regulated at multiple levels, including upstream at the enzymes involved in aspartate processing as well as at the initial DHDPS catalysed condensation step. Lysine imparts a strong negative feedback loop on these enzymes and, subsequently, regulates the entire pathway.


title: Lysine

text: The AAA pathway involves the condensation of α-ketoglutarate and acetyl-CoA via the intermediate AAA for the synthesis of -lysine. This pathway has been shown to be present in several yeast species, as well as protists and higher fungi. It has also been reported that an alternative variant of the AAA route has been found in "Thermus thermophilus" and "Pyrococcus horikoshii", which could indicate that this pathway is more widely spread in prokaryotes than originally proposed. The first and rate-limiting step in the AAA pathway is the condensation reaction between acetyl-CoA and α‑ketoglutarate catalysed by homocitrate-synthase (HCS) (E.C 2.3.3.14) to give the intermediate homocitryl‑CoA, which is hydrolysed by the same enzyme to produce homocitrate. Homocitrate is enzymatically dehydrated by homoaconitase (HAc) (E.C 4.2.1.36) to yield "cis"-homoaconitate. HAc then catalyses a second reaction in which "cis"-homoaconitate undergoes rehydration to produce homoisocitrate. The resulting product undergoes an oxidative decarboxylation by homoisocitrate dehydrogenase (HIDH) (E.C 1.1.1.87) to yield α‑ketoadipate. AAA is then formed via a pyridoxal 5′-phosphate (PLP)-dependent aminotransferase (PLP-AT) (E.C 2.6.1.39), using glutamate as the amino donor. From this point on, the AAA pathway varies with [something is missing here ? -> at the very least, section header! ] on the kingdom. In fungi, AAA is reduced to α‑aminoadipate-semialdehyde via AAA reductase (E.C 1.2.1.95) in a unique process involving both adenylation and reduction that is activated by a phosphopantetheinyl transferase (E.C 2.7.8.7). Once the semialdehyde is formed, saccharopine reductase (E.C 1.5.1.10) catalyses a condensation reaction with glutamate and NAD(P)H, as a proton donor, and the imine is reduced to produce the penultimate product, saccharopine. The final step of the pathway in fungi involves the saccharopine dehydrogenase (SDH) (E.C 1.5.1.8) catalysed oxidative deamination of saccharopine, resulting in -lysine. In a variant AAA pathway found in some prokaryotes, AAA is first converted to "N"‑acetyl-α-aminoadipate, which is phosphorylated and then reductively dephosphorylated to the ε-aldehyde. The aldehyde is then transaminated to "N"‑acetyllysine, which is deacetylated to give -lysine. However, the enzymes involved in this variant pathway need further validation.


title: Lysine

text: Like all amino acids, catabolism of lysine is initiated from the uptake of dietary lysine or from the breakdown of intracellular protein. Catabolism is also used as a means to control the intracellular concentration of free lysine and maintain a steady-state to prevent the toxic effects of excessive free lysine. There are several pathways involved in lysine catabolism but the most commonly used is the saccharopine pathway, which primarily takes place in the liver (and equivalent organs) in animals, specifically within the mitochondria. This is the reverse of the previously described AAA pathway. In animals and plants, the first two steps of the saccharopine pathway are catalysed by the bifunctional enzyme, α-aminoadipic semialdehyde synthase (AASS), which possess both lysine-ketoglutarate reductase (LKR) (E.C 1.5.1.8) and SDH activities, whereas in other organisms, such as bacteria and fungi, both of these enzymes are encoded by separate genes. The first step involves the LKR catalysed reduction of -lysine in the presence of α-ketoglutarate to produce saccharopine, with NAD(P)H acting as a proton donor. Saccharopine then undergoes a dehydration reaction, catalysed by SDH in the presence of NAD, to produce AAS and glutamate. AAS dehydrogenase (AASD) (E.C 1.2.1.31) then further dehydrates the molecule into AAA. Subsequently, PLP-AT catalyses the reverse reaction to that of the AAA biosynthesis pathway, resulting in AAA being converted to α-ketoadipate. The product, α‑ketoadipate, is decarboxylated in the presence of NAD and coenzyme A to yield glutaryl-CoA, however the enzyme involved in this is yet to be fully elucidated. Some evidence suggests that the 2-oxoadipate dehydrogenase complex (OADHc), which is structurally homologous to the E1 subunit of the oxoglutarate dehydrogenase complex (OGDHc) (E.C 1.2.4.2), is responsible for the decarboxylation reaction. Finally, glutaryl-CoA is oxidatively decarboxylated to crotonyl-CoA by glutaryl-CoA dehydrogenase (E.C 1.3.8.6), which goes on to be further processed through multiple enzymatic steps to yield acetyl-CoA; an essential carbon metabolite involved in the tricarboxylic acid cycle (TCA).


title: Lysine

text: Lysine is an essential amino acid in humans. The human daily nutritional requirement varies from ~60 mg/kg in infancy to ~30 mg/kg in adults. This requirement is commonly met in a western society with the intake of lysine from meat and vegetable sources well in excess of the recommended requirement. In vegetarian diets, the intake of lysine is less due to the limited quantity of lysine in cereal crops compared to meat sources.


title: Lysine

text: Given the limiting concentration of lysine in cereal crops, it has long been speculated that the content of lysine can be increased through genetic modification practices. Often these practices have involved the intentional dysregulation of the DAP pathway by means of introducing lysine feedback-insensitive orthologues of the DHDPS enzyme. These methods have met limited success likely due to the toxic side effects of increased free lysine and indirect effects on the TCA cycle. Plants accumulate lysine and other amino acids in the form of seed storage proteins, found within the seeds of the plant, and this represents the edible component of cereal crops. This highlights the need to not only increase free lysine, but also direct lysine towards the synthesis of stable seed storage proteins, and subsequently, increase the nutritional value of the consumable component of crops. While genetic modification practices have met limited success, more traditional selective breeding techniques have allowed for the isolation of "Quality Protein Maize", which has significantly increased levels of lysine and tryptophan, also an essential amino acid. This increase in lysine content is attributed to an "opaque-2" mutation that reduced the transcription of lysine-lacking zein-related seed storage proteins and, as a result, increased the abundance of other proteins that are rich in lysine. Commonly, to overcome the limiting abundance of lysine in livestock feed, industrially produced lysine is added. The industrial process includes the fermentative culturing of "Corynebacterium glutamicum" and the subsequent purification of lysine.


title: Lysine

text: Good sources of lysine are high-protein foods such as eggs, meat (specifically red meat, lamb, pork, and poultry), soy, beans and peas, cheese (particularly Parmesan), and certain fish (such as cod and sardines). Lysine is the limiting amino acid (the essential amino acid found in the smallest quantity in the particular foodstuff) in most cereal grains, but is plentiful in most pulses (legumes). Beans contain the lysine that maize lacks, and in the human archeological record beans and maize often appear together, as in the Three Sisters: beans, maize, and squash.


title: Lysine

text: A food is considered to have sufficient lysine if it has at least 51 mg of lysine per gram of protein (so that the protein is 5.1% lysine). -lysine HCl is used as a dietary supplement, providing 80.03% -lysine. As such, 1 g of -lysine is contained in 1.25 g of -lysine HCl.


title: Lysine

text: The most common role for lysine is proteinogenesis. Lysine frequently plays an important role in protein structure. Since its side chain contains a positively charged group on one end and a long hydrophobic carbon tail close to the backbone, lysine is considered somewhat amphipathic. For this reason, lysine can be found buried as well as more commonly in solvent channels and on the exterior of proteins, where it can interact with the aqueous environment. Lysine can also contribute to protein stability as its ε-amino group often participates in hydrogen bonding, salt bridges and covalent interactions to form a Schiff base.


title: Lysine

text: A second major role of lysine is in epigenetic regulation by means of histone modification. There are several types of covalent histone modifications, which commonly involve lysine residues found in the protruding tail of histones. Modifications often include the addition or removal of an acetyl (−CHCO) forming acetyllysine or reverting to lysine, up to three methyl (−CH), ubiquitin or a sumo protein group. The various modifications have downstream effects on gene regulation, in which genes can be activated or repressed.


title: Lysine

text: Lysine has also been implicated to play a key role in other biological processes including; structural proteins of connective tissues, calcium homeostasis, and fatty acid metabolism. Lysine has been shown to be involved in the crosslinking between the three helical polypeptides in collagen, resulting in its stability and tensile strength. This mechanism is akin to the role of lysine in bacterial cell walls, in which lysine (and "meso"-diaminopimelate) are critical to the formation of crosslinks, and therefore, stability of the cell wall. This concept has previously been explored as a means to circumvent the unwanted release of potentially pathogenic genetically modified bacteria. It was proposed that an auxotrophic strain of "Escherichia coli" (1776) could be used for all genetic modification practices, as the strain is unable to survive without the supplementation of DAP, and thus, cannot live outside of a laboratory environment. Lysine has also been proposed to be involved in calcium intestinal absorption and renal retention, and thus, may play a role in calcium homeostasis. Finally, lysine has been shown to be a precursor for carnitine, which transports fatty acids to the mitochondria, where they can be oxidised for the release of energy. Carnitine is synthesised from trimethyllysine, which is a product of the degradation of certain proteins, as such lysine must first be incorporated into proteins and be methylated prior to being converted to carnitine. However, in mammals the primary source of carnitine is through dietary sources, rather than through lysine conversion.


title: Lysine

text: In opsins like rhodopsin and the visual opsins (encoded by the genes OPN1SW, OPN1MW, and OPN1LW), retinaldehyde forms a Schiff base with a conserved lysine residue, and interaction of light with the retinylidene group causes signal transduction in color vision (See visual cycle for details).


title: Lysine

text: There has been a long discussion that lysine, when administered intravenously or orally, can significantly increase the release of growth hormones. This has led to athletes using lysine as a means of promoting muscle growth while training, however, no significant evidence to support this application of lysine has been found to date.


title: Lysine

text: Because herpes simplex virus (HSV) proteins are richer in arginine and poorer in lysine than the cells they infect, lysine supplements have been tried as a treatment. Since the two amino acids are taken up in the intestine, reclaimed in the kidney, and moved into cells by the same amino acid transporters, an abundance of lysine would, in theory, limit the amount of arginine available for viral replication. Clinical studies do not provide good evidence for effectiveness as a prophylactic or in the treatment for HSV outbreaks. In response to product claims that lysine could improve immune responses to HSV, a review by the European Food Safety Authority found no evidence of a cause–effect relationship. The same review, published in 2011, found no evidence to support claims that lysine could lower cholesterol, increase appetite, contribute to protein synthesis in any role other than as an ordinary nutrient, or increase calcium absorption or retention.


title: Lysine

text: Diseases related to lysine are a result of the downstream processing of lysine, i.e. the incorporation into proteins or modification into alternative biomolecules. The role of lysine in collagen has been outlined above, however, a lack of lysine and hydroxylysine involved in the crosslinking of collagen peptides has been linked to a disease state of the connective tissue. As carnitine is a key lysine-derived metabolite involved in fatty acid metabolism, a substandard diet lacking sufficient carnitine and lysine can lead to decreased carnitine levels, which can have significant cascading effects on an individual's health. Lysine has also been shown to play a role in anaemia, as lysine is suspected to have an effect on the uptake of iron and, subsequently, the concentration of ferritin in blood plasma. However, the exact mechanism of action is yet to be elucidated. Most commonly, lysine deficiency is seen in non-western societies and manifests as protein-energy malnutrition, which has profound and systemic effects on the health of the individual. There is also a hereditary genetic disease that involves mutations in the enzymes responsible for lysine catabolism, namely the bifunctional AASS enzyme of the saccharopine pathway. Due to a lack of lysine catabolism, the amino acid accumulates in plasma and patients develop hyperlysinaemia, which can present as asymptomatic to severe neurological disabilities, including epilepsy, ataxia, spasticity, and psychomotor impairment. The clinical significance of hyperlysinemia is the subject of debate in the field with some studies finding no correlation between physical or mental disabilities and hyperlysinemia. In addition to this, mutations in genes related to lysine metabolism have been implicated in several disease states, including pyridoxine-dependent epilepsia (ALDH7A1 gene), α-ketoadipic and α-aminoadipic aciduria (DHTKD1 gene), and glutaric aciduria type 1 (GCDH gene).


title: Lysine

text: Hyperlysinuria is marked by high amounts of lysine in the urine. It is often due to a metabolic disease in which a protein involved in the breakdown of lysine is non functional due to a genetic mutation. It may also occur due to a failure of renal tubular transport.


title: Lysine

text: Lysine production for animal feed is a major global industry, reaching in 2009 almost 700,000 tons for a market value of over €1.22 billion. Lysine is an important additive to animal feed because it is a limiting amino acid when optimizing the growth of certain animals such as pigs and chickens for the production of meat. Lysine supplementation allows for the use of lower-cost plant protein (maize, for instance, rather than soy) while maintaining high growth rates, and limiting the pollution from nitrogen excretion. In turn, however, phosphate pollution is a major environmental cost when corn is used as feed for poultry and swine.


title: Lysine

text: Lysine is industrially produced by microbial fermentation, from a base mainly of sugar. Genetic engineering research is actively pursuing bacterial strains to improve the efficiency of production and allow lysine to be made from other substrates.


title: Lysine

text: The 1993 film "Jurassic Park", which is based on the 1990 novel "Jurassic Park" by Michael Crichton, features dinosaurs that were genetically altered so that they could not produce lysine, an example of engineered auxotrophy. This was known as the "lysine contingency" and was supposed to prevent the cloned dinosaurs from surviving outside the park, forcing them to depend on lysine supplements provided by the park's veterinary staff. In reality, no animal can produce lysine, it is an essential amino acid.


title: Lysine

text: In 1996, lysine became the focus of a price-fixing case, the largest in United States history. The Archer Daniels Midland Company paid a fine of US$100 million, and three of its executives were convicted and served prison time. Also found guilty in the price-fixing case were two Japanese firms (Ajinomoto, Kyowa Hakko) and a South Korean firm (Sewon). Secret video recordings of the conspirators fixing lysine's price can be found online or by requesting the video from the U.S. Department of Justice, Antitrust Division. This case gave the basis for the movie "The Informant!", and the book "The Informant: A True Story".


title: Détente

text: Détente (, French: "relaxation") is the relaxation of strained relations, especially political ones, through verbal communication. The term, in diplomacy, originates from around 1912, when France and Germany tried unsuccessfully to reduce tensions.


title: Détente

text: The term is often used to refer to a period of general easing of the geopolitical tensions between the Soviet Union and the United States during the Cold War. It began in 1969, as a core element of the foreign policy of US President Richard Nixon, in an effort to avoid nuclear escalation. The Nixon administration promoted greater dialogue with the Soviet government, including regular summit meetings and negotiations over arms control and other bilateral agreements. Détente was known in Russian as разрядка ("razryadka"), loosely meaning "relaxation of tension".


title: Détente

text: The period was characterized by the signing of treaties such as SALT I and the Helsinki Accords. Another treaty, SALT II, was discussed but never ratified by the US. There is still an ongoing debate among historians as to how successful the détente period was in achieving peace.


title: Détente

text: After the Cuban Missile Crisis in 1962, both the superpowers agreed to install a direct hotline between Washington, DC, and Moscow. The so-called red telephone enabled leaders of both countries to communicate with each other quickly in times of urgency and to reduce the chances of future crises escalating into an all-out war.


title: Détente

text: The American-Soviet détente was presented as an applied extension of that thinking. SALT II, in the late 1970s, continued the work of the SALT I talks by ensuring further reduction in arms by the Soviet Union and by the US. The Helsinki Accords, in which the Soviets promised to grant free elections in Europe, were called a major concession to ensure peace by the Soviets.


title: Détente

text: Détente ended after the Soviet intervention in Afghanistan, which led to the United States' boycott of the 1980 Olympics, held in Moscow. Ronald Reagan's election as president in 1980, based in large part on an anti-détente campaign, marked the end of détente and a return to Cold War tensions. In his first press conference, Reagan said, "Détente's been a one-way street that the Soviet Union has used to pursue its aims." Relations continued to turn increasingly sour with the unrest in Poland, the end of the SALT II negotiations, and the NATO exercise in 1983, the last of which brought the superpowers almost to the brink of nuclear war. However, The State department under George P. Shultz took a more diplomatic approach beginning in 1983, purging anti-détente advocates from its leadership, with the strong support of Reagan and the Foreign Service. Formal negotiations for what was then known as "SALT III" began in 1983 which culminated in the START I. Diplomatic overtures were continued by the succeeding Bush administration up until the collapse of the Soviet Union in 1991; consequently, the period 1983–1991 is sometimes referred to as the second period of détente.


title: Détente

text: According to Eric Grynaviski, "Soviet and US decision-makers had two very different understandings about what détente meant" while simultaneously holding "an inaccurate belief that both sides shared principles and expectations for future behaviour."


title: Détente

text: The most obvious manifestations of détente were the series of summits between Soviet and US leaders and the treaties that resulted from those meetings. In the early 1960s, before détente, the Partial Nuclear Test Ban Treaty was signed (5 August 1963). Later that decade, the January 1967 Outer Space Treaty and the July 1968 Treaty on the Non-Proliferation of Nuclear Weapons were two of the first building blocks of détente. The first treaties were signed all over the globe.


title: Détente

text: When Nixon came into office in 1969, several important détente treaties were developed. The Political Consultative Committee of the Warsaw Pact sent an offer to the US and the rest of the West that urged a summit on "security and cooperation in Europe" to be held. The West agreed, and the Strategic Arms Limitation Talks began towards actual limits in on the nuclear capabilities of both superpowers, which ultimately led to the signing of the SALT I treaty in 1972. It limited each power's nuclear arsenals but was quickly rendered outdated as a result of the development of MIRVs. Also in 1972, the Biological Weapons Convention and the Anti-Ballistic Missile Treaty were concluded, and talks on SALT II began the same year. The Washington Summit of 1973 further advanced mutual and international relations through discussion of diplomatic cooperation and continued discussion regarding limitations on nuclear weaponry.


title: Détente

text: In 1975, the Conference on Security and Cooperation (CSCE) in Europe met and produced the Helsinki Accords, a wide-ranging series of agreements on economic, political, and human rights issues. The CSCE was initiated by the Soviet Union and involved 35 states throughout Europe. One of the most prevalent and discussed issues after the conference was of human rights violations in the Soviet Union. The Soviet Constitution directly violated the Declaration of Human Rights of the United Nations, and that issue became a prominent point of separation between the United States and the Soviet Union.


title: Détente

text: The Carter administration had been supporting human rights groups inside the Soviet Union, and Leonid Brezhnev accused the US of interference in other countries' internal affairs. That prompted intense discussion of whether or not other nations may interfere if basic human rights, such as freedom of speech and religion, are violated. This basic disagreement between the superpowers, a democracy, and a one-party state, did not allow that issue to be reconciled. Furthermore, the Soviets proceeded to defend their internal policies on human rights by attacking American support of South Africa, Chile, and other countries that were known to violate many of the same human rights.


title: Détente

text: In July 1975, the Apollo–Soyuz Test Project became the first international space mission; three American astronauts and two Soviet cosmonauts docked their spacecraft and conducted joint experiments. The mission had been preceded by five years of political negotiation and technical co-operation, including exchanges of American and Soviet engineers between both countries' space centres.


title: Détente

text: Trade relations between both blocs increased substantially during the era of détente. Most significant were the vast shipments of grain that were sent from the West to the Soviet Union each year and helped to make up for the failure of the kolkhoz, the Soviet collective farms.


title: Détente

text: At the same time, the Jackson–Vanik Amendment, signed into US federal law by US President Gerald Ford on 3 January 1975 after a unanimous vote by both houses of the US Congress, was designed to leverage trade relations between the Americans and the Soviets. It linked US trade to improvements in human rights in the Soviet Union, particularly by allowing refuseniks to emigrate. It also added to the most favoured nation status a clause that no country that resisted emigration could be awarded that status, which provided a method to link geopolitics to human rights.


title: Détente

text: Richard Nixon and his National Security Adviser, Henry Kissinger, moved toward détente with the Soviet Union in the early 1970s. They hoped, in return, for Soviet help the US extricate or remove itself from Vietnam. People then started to notice the consciousness with which US politicians started to act.


title: Détente

text: Richard Nixon and Leonid Brezhnev signed an ABM treaty in Moscow on 26 May 1972 as well as the Interim Agreement (SALT I), which temporarily capped the number of strategic arms (MIRVs, SLBMs, and ICBMs). That was a show of détente militarily since an expansion of nuclear ballistic arms had started to occur.


title: Détente

text: The goal of Nixon and Kissinger was to use arms control to promote a much broader policy of détente, which could then allow the resolution of other urgent problems through what Nixon called "linkage." David Tal argued:


title: Détente

text: A significant example of an event contributing to détente was the handshake that took place in space. In July 1975, the first Soviet-American joint space flight was conducted, the Apollo–Soyuz Test Project. Its primary goal was the creation of an international docking system, which would allow two different spacecraft to join in orbit. That would allow both crews on board to collaborate on space exploration. The project marked the end of the Space Race, which had started in 1957 with the launch of Sputnik 1, and allowed tensions between the Americans and the Soviets to decrease significantly.


title: Détente

text: As direct relations thawed, increased tensions continued between both superpowers through their proxies, especially in the Third World. Conflicts in South Asia and the Middle East in 1973 saw the Soviet Union and the US backing their respective surrogates, such as in Afghanistan, with war material and diplomatic posturing. In Latin America, the US continued to block any left-wing electoral shifts in the region by supporting unpopular right-wing military coups and military dictatorships. Meanwhile, there were also many communist or left-wing guerrillas around the region, which were military and economically backed by the Soviet Union, China and Cuba.


title: Détente

text: During much of the early détente period, the Vietnam War continued to rage. Both sides still mistrusted each other, and the potential for nuclear war remained constant, notably during the 1973 Yom Kippur War when the United States raised its alert level to DEFCON III, the highest since the Cuban Missile Crisis.


title: Détente

text: Both sides continued aiming thousands of nuclear warheads atop intercontinental ballistic missiles (ICBMs) at each other's cities, maintaining submarines with long-range nuclear weapon capability (submarine-launched ballistic missiles, or SLBMs) in the world's oceans, keeping hundreds of nuclear-armed aircraft on constant alert, and guarding contentious borders in Korea and Europe with large ground forces. Espionage efforts remained a high priority, and defectors, reconnaissance satellites, and signal intercepts measured each other's intentions to try to gain a strategic advantage.


title: Détente

text: The 1979 Soviet invasion of Afghanistan, carried out in an attempt to shore up a struggling pro-Soviet regime, led to harsh international criticisms, and a boycott of the 1980 Summer Olympics, held in Moscow. US President Jimmy Carter boosted the budget of the US Defense Department and began financial aid to the office of Pakistani President Muhammad Zia-ul-Haq, who, in turn, subsidized the anti-Soviet radical Islamist group of mujahideen fighters in Afghanistan.


title: Détente

text: Another contributing factor in the decline in the popularity of détente as a desirable US policy was the interservice rivalry between the US State Department and Department of Defense. From 1973 to 1977, there were three secretaries worth mentioning: Elliot Richardson, James Schlesinger, and Donald Rumsfeld. Schlesinger's tenure as Secretary of Defense was plagued by notably poor relations with Kissinger, one of the most prominent advocates of détente in the US. Their poor working relationship bled into their professional relationship, and policy clashes would increasingly occur. They ultimately resulted in Schlesinger's dismissal in 1975. However, his replacement, Rumsfeld, shared Schlesinger's distaste for Kissinger.


title: Détente

text: As a result, clashes on policy continued between the State and the Defense Departments. Rumsfeld thought that Kissinger was too complacent about the growing Soviet strength. Although Rumsfeld largely agreed with Kissinger's that the United States held military superiority over the Soviet Union, he argued that Kissinger's public optimism would prevent Congress from allowing Defense Department the funds that Rumsfeld believed were required to maintain the favorable gap between the US and the Soviets. Rumsfeld responded by regularly presenting a more alarmist view of the superior strength of the Soviets.


title: Détente

text: In response to the stranglehold of influence by Kissinger in the Nixon and Ford administrations and the later decline in influence over foreign policy by the Department of Defense, Richardson, Schlesinger, and Rumsfeld all used the growing antipathy in the US for the Soviet Union to undermine Kissinger's attempts to achieve a comprehensive arms reduction treaty. That helped to portray the entire notion of détente as an untenable policy.


title: Détente

text: The 1980 American presidential election saw Ronald Reagan elected on a platform opposed to the concessions of détente. Negotiations on SALT II were abandoned as a result. However, during the later years of Reagan's presidency, he and Soviet General Secretary Mikhail Gorbachev pursued a policy that was considered to be détente.


title: Détente

text: However, the Reagan administration talked about a "winnable" nuclear war and led to the creation of the Strategic Defense Initiative and the Third World policy of funding irregular and paramilitary death squads in Central America, Sub-Saharan Africa, Cambodia, and Afghanistan.


title: Détente

text: On 17 December 2014, US President Barack Obama and Cuban President Raúl Castro resolved to restore diplomatic relations between Cuba and the United States. The restoration agreement had been negotiated in secret in the preceding months. The negotiations were facilitated by Pope Francis and hosted mostly by the Canadian government, which had warmer relations with Cuba at that time. Meetings were held in both Canada and the Vatican City. The agreement would see some United States travel restrictions lifted, fewer restrictions on remittances, greater access to the Cuban financial system for United States banks, and the reopening of the United States embassy in Havana and the Cuban embassy in Washington, which both closed in 1961 after the breakup of diplomatic relations as a result of Cuba's alliance with the Soviet Union. On 14 April 2015, the Obama administration announced the removal of Cuba from the State Sponsors of Terrorism list. Cuba was officially removed from the list on 29 May 2015. On 20 July 2015, the Cuban and US interest sections in Washington and Havana were upgraded to embassies. On 24 March 2016, Obama became the first US president to visit Cuba, since 1928.


title: Détente

text: However, in 2017, Donald Trump – who had succeeded Obama as United States' president – stated that he was "canceling" the Obama administration's deals with Cuba, while also expressing that a new deal could be negotiated between the Cuban and United States governments.


title: Khuda Haafiz

text: Khuda Haafiz () is a 2020 Indian Hindi-language direct-to-video action thriller film written and directed by Faruk Kabir and produced by Kumar Mangat Pathak and Abhishek Pathak under Panorama Studios. It stars Vidyut Jammwal and Shivaleeka Oberoi, with Annu Kapoor, Aahana Kumra and Shiv Panditt in supporting roles. Set during the financial crisis of 2007–2008, the film is inspired by true events and follows Sameer Chaudhary, a young man who races against time to rescue his kidnapped wife Nargis from flesh traders. The film premiered on Disney+ Hotstar on 14 August 2020. The film received mixed reviews from critics and positive response from audience, praising the cast's performance, action sequences and technical aspects. It was a success in Disney+ Hotstar.


title: Khuda Haafiz

text: In 2007, Sameer Chowdhary is a software engineer and businessman who falls in love with Nargis and the two get married. A financial crisis in 2008 leaves them both jobless. Three months later, they get jobs in a fictional Middle east country named Noman, with the help of Nadeem, an employee at an overseas recruitment company. Nargis leaves first, and Sameer stays to wait for his documents to arrive. After her arrival, Nargis calls Sameer in a panic, crying that someone is kidnapping her. Sameer travels to Noman, where he meets Usman Hamid Ali Murad, a taxi driver. He asks Usman to take him to the address given by Nadeem but learns there's no such address. Usman takes Sameer to the police station, where he learns that Nadeem has gone missing. Fallen out of help with the police due to his restless nature, Sameer approaches the Indian embassy. He poses as an employee of a telecom company and acquires the address of the person from whose phone Nargis contacted him, and it turns out to be a man named Shirazi. Sameer and Usman learn about Shirazi's involvement in the flesh trade.


title: Khuda Haafiz

text: Sameer visits brothels with Usman in search of Nargis and finds her in one, but he is attacked by the owners and turns violent, killing men, followed by a car chase that ends with a crash and his arrest by the Indian Embassy cops, as Sameer has finished narrating his story, he is approached by a Nomani cop named Faiz Abu Malik who decides to help him, with officer Tamena joining along. They view the CCTV footage of the Noman airport, where they see Nargis entering a van with a man revealed to be Iztek, an Algerian modelling coordinator. Iztek orders that Nargis be killed. Faiz and Tamena come across a burnt corpse and believe it to be Nargis. Sameer sees her pendant on it and is shattered. Following her funeral, he is given compensation and tickets to India. Tamena learns Nargis is alive, and the corpse they found was of a different woman. She and Faiz try to find Sameer before learning he never boarded the flight. Now wanting revenge, Sameer disguises himself and arrives at Iztek's house. The two violently fight before Iztek reveals Nargis is alive. Faiz and Tamena arrive, and Faiz is revealed to be Iztek's ally. Tamena subdues Faiz long enough to buy Sameer time to escape.


title: Khuda Haafiz

text: Faiz kills Tamena and frames Sameer. An ensuing chase leaves Iztek dead. Faiz meets his crime partner, Iztek's boss, which is photographed by an undercover cop. Sameer is captured by Faiz before his betrayal is revealed by the commissioner. Sameer and Faiz engage in a fistfight where Sameer beats Faiz. Nargis and the other women are freed, and Tamena is given a State funeral. Faiz wakes up in a pound in the middle of a desert in front of a firing squad for his crimes. They shoot him to death. Sameer and Nargis prepare to depart the plane for India while making the last meeting with Usman. Sameer invites Usman to come to India and meet with their family, as they greet him before leaving.


title: Khuda Haafiz

text: The music for the film was composed by Mithoon who also wrote lyrics for four of the tracks, with Sayeed Quadri penning two songs in the soundtrack album.


title: Khuda Haafiz

text: On 29 June 2020, Disney+ Hotstar conducted a virtual press conference where Uday Shankar announced the film's digital release on the platform on 14 August 2020, exclusively as part of the "Disney+ Hotstar Multiplex" initiative which was a result of cinemas being shut down due to COVID-19 pandemic. However, Vidyut Jammwal was not invited for the social media announcement, along with Kunal Khemu, whose film "Lootcase" also released on the same digital streaming platform. Disney+ Hotstar released and promoted the film's trailer first, through the streaming application on 24 July 2020, along with the much anticipated premiere of Sushant Singh Rajput's last film "Dil Bechara". The trailer was launched through YouTube, the following day.


title: Khuda Haafiz

text: Saibal Chatterjee of NDTV gave the film 3/5, mentioning, "The spirit of this film, for whatever it is worth, is best exemplified by the hero wishing a friend Khuda Haafiz with his hands folded to denote a namaste. That alone would have set Khuda Haafiz apart if only it had been a better film."


title: Khuda Haafiz

text: A sequel titled "Khuda Haafiz Chapter II Agni Pariksha" was announced in September 2020 after the success of the first part with Kumar Mangat and Abhishek Pathak as the producers and Faruk Kabir as the director. Vidyut Jammwal and Shivaleeka Oberoi will reprise their roles, and the sequel will go on floors in March 2021 before releasing in October 2021 in cinemas.


title: Gideon Adlon

text: Gideon Adlon (born ) is an American actress. She is best known for her starring roles in the comedy film "Blockers" (2018), the drama film "The Mustang" (2019), and the horror film "" (2020). Adlon also starred in the Netflix drama series "The Society" (2019). She is also known for playing Violet in the video game "" (2018).


title: Gideon Adlon

text: Adlon was born in Los Angeles and holds both American and German citizenship through her father. She is the oldest daughter of actress Pamela Adlon and director Felix O. Adlon. Her younger sisters are actress Odessa A'zion and Valentine "Rocky" Adlon. Her paternal grandfather is German filmmaker Percy Adlon and her maternal grandfather was American writer-producer Don Segall. Her maternal grandfather was born to a Jewish family, and her English-born maternal grandmother, originally an Anglican, converted to Judaism. Through her father, she descends from the German hotelier Lorenz Adlon.


title: Gideon Adlon

text: Adlon studied Photography at Columbia College Chicago for a year before deciding to pursue acting full-time.


title: Gideon Adlon

text: Adlon made her professional acting debut in a 2011 episode of the FX comedy-drama series "Louie", which also featured her mother Pamela. She went on to make guest appearances in the Disney Channel sitcom "Girl Meets World" (2016), the FX comedy-drama series "Better Things" (2016), the ABC miniseries "When We Rise" (2017), the CBS crime drama series "Criminal Minds" (2017), and the ABC anthology crime drama series "American Crime" (2017).


title: Gideon Adlon

text: Adlon received further recognition for her first starring role in the sex comedy film "Blockers" (2018), which received positive reviews and box office success. She went on to star in the critically acclaimed drama film "The Mustang" (2019). Also in 2019, Adlon had a starring role as Becca Gelb in the Netflix mystery teen drama series "The Society". The series was originally renewed for a second season, but was later canceled as a result of the COVID-19 pandemic causing cost increases and difficulty scheduling production.


title: Gideon Adlon

text: Adlon starred as Frankie in the horror sequel film "", which was released on October 28, 2020. In 2021 she starred as Claire in the horror fantasy film "Witch Hunt".


title: Stochastic gradient descent

text: Stochastic gradient descent (often abbreviated SGD) is an iterative method for optimizing an objective function with suitable smoothness properties (e.g. differentiable or subdifferentiable). It can be regarded as a stochastic approximation of gradient descent optimization, since it replaces the actual gradient (calculated from the entire data set) by an estimate thereof (calculated from a randomly selected subset of the data). Especially in high-dimensional optimization problems this reduces the very high computational burden, achieving faster iterations in trade for a lower convergence rate.


title: Stochastic gradient descent

text: While the basic idea behind stochastic approximation can be traced back to the Robbins–Monro algorithm of the 1950s, stochastic gradient descent has become an important optimization method in machine learning.


title: Stochastic gradient descent

text: Both statistical estimation and machine learning consider the problem of minimizing an objective function that has the form of a sum:


title: Stochastic gradient descent

text: where the parameter formula_2 that minimizes formula_3 is to be estimated. Each summand function formula_4 is typically associated with the formula_5-th observation in the data set (used for training).


title: Stochastic gradient descent

text: In classical statistics, sum-minimization problems arise in least squares and in maximum-likelihood estimation (for independent observations). The general class of estimators that arise as minimizers of sums are called M-estimators. However, in statistics, it has been long recognized that requiring even local minimization is too restrictive for some problems of maximum-likelihood estimation. Therefore, contemporary statistical theorists often consider stationary points of the likelihood function (or zeros of its derivative, the score function, and other estimating equations).


title: Stochastic gradient descent

text: The sum-minimization problem also arises for empirical risk minimization. In this case, formula_6 is the value of the loss function at formula_5-th example, and formula_3 is the empirical risk.


title: Stochastic gradient descent

text: When used to minimize the above function, a standard (or "batch") gradient descent method would perform the following iterations:


title: Stochastic gradient descent

text: In many cases, the summand functions have a simple form that enables inexpensive evaluations of the sum-function and the sum gradient. For example, in statistics, one-parameter exponential families allow economical function-evaluations and gradient-evaluations.


title: Stochastic gradient descent

text: However, in other cases, evaluating the sum-gradient may require expensive evaluations of the gradients from all summand functions. When the training set is enormous and no simple formulas exist, evaluating the sums of gradients becomes very expensive, because evaluating the gradient requires evaluating all the summand functions' gradients. To economize on the computational cost at every iteration, stochastic gradient descent samples a subset of summand functions at every step. This is very effective in the case of large-scale machine learning problems.


title: Stochastic gradient descent

text: In stochastic (or "on-line") gradient descent, the true gradient of formula_3 is approximated by a gradient at a single sample:


title: Stochastic gradient descent

text: As the algorithm sweeps through the training set, it performs the above update for each training sample. Several passes can be made over the training set until the algorithm converges. If this is done, the data can be shuffled for each pass to prevent cycles. Typical implementations may use an adaptive learning rate so that the algorithm converges.


title: Stochastic gradient descent

text: A compromise between computing the true gradient and the gradient at a single sample is to compute the gradient against more than one training sample (called a "mini-batch") at each step. This can perform significantly better than "true" stochastic gradient descent described, because the code can make use of vectorization libraries rather than computing each step separately as was first shown in where it was called "the bunch-mode back-propagation algorithm". It may also result in smoother convergence, as the gradient computed at each step is averaged over more training sample.


title: Stochastic gradient descent

text: The convergence of stochastic gradient descent has been analyzed using the theories of convex minimization and of stochastic approximation. Briefly, when the learning rates formula_10 decrease with an appropriate rate,


title: Stochastic gradient descent

text: and subject to relatively mild assumptions, stochastic gradient descent converges almost surely to a global minimum


title: Stochastic gradient descent

text: Let's suppose we want to fit a straight line formula_14 to a training set with observations formula_15 and corresponding estimated responses formula_16 using least squares. The objective function to be minimized is:


title: Stochastic gradient descent

text: Note that in each iteration (also called update), the gradient is only evaluated at a single point formula_19 instead of at the set of all samples.


title: Stochastic gradient descent

text: The key difference compared to standard (Batch) Gradient Descent is that only one piece of data from the dataset is used to calculate the step, and the piece of data is picked randomly at each step.


title: Stochastic gradient descent

text: Stochastic gradient descent is a popular algorithm for training a wide range of models in machine learning, including (linear) support vector machines, logistic regression (see, e.g., Vowpal Wabbit) and graphical models. When combined with the backpropagation algorithm, it is the "de facto" standard algorithm for training artificial neural networks. Its use has been also reported in the Geophysics community, specifically to applications of Full Waveform Inversion (FWI).


title: Stochastic gradient descent

text: Stochastic gradient descent competes with the L-BFGS algorithm, which is also widely used. Stochastic gradient descent has been used since at least 1960 for training linear regression models, originally under the name ADALINE.


title: Stochastic gradient descent

text: Many improvements on the basic stochastic gradient descent algorithm have been proposed and used. In particular, in machine learning, the need to set a learning rate (step size) has been recognized as problematic. Setting this parameter too high can cause the algorithm to diverge; setting it too low makes it slow to converge. A conceptually simple extension of stochastic gradient descent makes the learning rate a decreasing function of the iteration number , giving a "learning rate schedule", so that the first iterations cause large changes in the parameters, while the later ones do only fine-tuning. Such schedules have been known since the work of MacQueen on -means clustering. Practical guidance on choosing the step size in several variants of SGD is given by Spall.


title: Stochastic gradient descent

text: As mentioned earlier, classical stochastic gradient descent is generally sensitive to learning rate . Fast convergence requires large learning rates but this may induce numerical instability. The problem can be largely solved by considering "implicit updates" whereby the stochastic gradient is evaluated at the next iterate rather than the current one:


title: Stochastic gradient descent

text: This equation is implicit since formula_21 appears on both sides of the equation. It is a stochastic form of the proximal gradient method since the update


title: Stochastic gradient descent

text: Note that formula_27 could have "1" as the first element to include an intercept. Classical stochastic gradient descent proceeds as follows:


title: Stochastic gradient descent

text: where formula_5 is uniformly sampled between 1 and formula_30. Although theoretical convergence of this procedure happens under relatively mild assumptions, in practice the procedure can be quite unstable. In particular, when formula_10 is misspecified so that formula_32 has large absolute eigenvalues with high probability, the procedure may diverge numerically within a few iterations. In contrast, "implicit stochastic gradient descent" (shortened as ISGD) can be solved in closed-form as:


title: Stochastic gradient descent

text: This procedure will remain numerically stable virtually for all formula_10 as the learning rate is now normalized. Such comparison between classical and implicit stochastic gradient descent in the least squares problem is very similar to the comparison between least mean squares (LMS) and


title: Stochastic gradient descent

text: Even though a closed-form solution for ISGD is only possible in least squares, the procedure can be efficiently implemented in a wide range of models. Specifically, suppose that formula_6 depends on formula_2 only through a linear combination with features formula_37, so that we can write formula_38, where


title: Stochastic gradient descent

text: formula_39 may depend on formula_40 as well but not on formula_2 except through formula_42. Least squares obeys this rule, and so does logistic regression, and most generalized linear models. For instance, in least squares, formula_43, and in logistic regression formula_44, where formula_45 is the logistic function. In Poisson regression, formula_46, and so on.


title: Stochastic gradient descent

text: in most regular models, such as the aforementioned generalized linear models, function formula_51 is decreasing,


title: Stochastic gradient descent

text: Further proposals include the "momentum method", which appeared in Rumelhart, Hinton and Williams' paper on backpropagation learning. Stochastic gradient descent with momentum remembers the update at each iteration, and determines the next update as a linear combination of the gradient and the previous update:


title: Stochastic gradient descent

text: where the parameter formula_2 which minimizes formula_3 is to be estimated, formula_10 is a step size (sometimes called the "learning rate" in machine learning) and formula_60 is an exponential decay factor between 0 and 1 that determines the relative contribution of the current gradient and earlier gradients to the weight change.


title: Stochastic gradient descent

text: The name momentum stems from an analogy to momentum in physics: the weight vector formula_2, thought of as a particle traveling through parameter space, incurs acceleration from the gradient of the loss ("force"). Unlike in classical stochastic gradient descent, it tends to keep traveling in the same direction, preventing oscillations. Momentum has been used successfully by computer scientists in the training of artificial neural networks for several decades.


title: Stochastic gradient descent

text: The "momentum method" is closely related to underdamped Langevin dynamics, and may be combined with Simulated Annealing.


title: Stochastic gradient descent

text: "Averaged stochastic gradient descent", invented independently by Ruppert and Polyak in the late 1980s, is ordinary stochastic gradient descent that records an average of its parameter vector over time. That is, the update is the same as for ordinary stochastic gradient descent, but the algorithm also keeps track of


title: Stochastic gradient descent

text: "AdaGrad" (for adaptive gradient algorithm) is a modified stochastic gradient descent algorithm with per-parameter learning rate, first published in 2011. Informally, this increases the learning rate for sparser parameters and decreases the learning rate for ones that are less sparse. This strategy often improves convergence performance over standard stochastic gradient descent in settings where data is sparse and sparse parameters are more informative. Examples of such applications include natural language processing and image recognition. It still has a base learning rate , but this is multiplied with the elements of a vector which is the diagonal of the outer product matrix


title: Stochastic gradient descent

text: Each gives rise to a scaling factor for the learning rate that applies to a single parameter . Since the denominator in this factor, formula_68 is the "ℓ" norm of previous derivatives, extreme parameter updates get dampened, while parameters that get few or small updates receive higher learning rates.


title: Stochastic gradient descent

text: While designed for convex problems, AdaGrad has been successfully applied to non-convex optimization.


title: Stochastic gradient descent

text: "RMSProp" (for Root Mean Square Propagation) is also a method in which the learning rate is adapted for each of the parameters. The idea is to divide the learning rate for a weight by a running average of the magnitudes of recent gradients for that weight.


title: Stochastic gradient descent

text: RMSProp has shown good adaptation of learning rate in different applications. RMSProp can be seen as a generalization of Rprop and is capable to work with mini-batches as well opposed to only full-batches.


title: Stochastic gradient descent

text: "Adam" (short for Adaptive Moment Estimation) is an update to the "RMSProp" optimizer. In this optimization algorithm, running averages of both the gradients and the second moments of the gradients are used. Given parameters formula_72 and a loss function formula_73, where formula_74 indexes the current training iteration (indexed at formula_75), Adam's parameter update is given by:


title: Stochastic gradient descent

text: where formula_81 is a small scalar (e.g. formula_82) used to prevent division by 0, and formula_83 (e.g. 0.9) and formula_84 (e.g. 0.999) are the forgetting factors for gradients and second moments of gradients, respectively. Squaring and square-rooting is done element-wise. The profound influence of this algorithm inspired multiple newer, less well-known momentum-based optimization schemes using Nesterov-enhanced gradients (eg: "NAdam" and "FASFA") and varying interpretations of second-order information (eg: "Powerpropagation" and "AdaSqrt"). However, the most commonly used variants are "AdaMax", which generalizes "Adam" using the infinity norm, and "AMSGrad", which addresses convergence problems from "Adam."


title: Stochastic gradient descent

text: Backtracking line search is another variant of gradient descent. All of the below are sourced from the mentioned link. It is based on a condition known as the Armijo–Goldstein condition. Both methods allow learning rates to change at each iteration; however, the manner of the change is different. Backtracking line search uses function evaluations to check Armijo's condition, and in principle the loop in the algorithm for determining the learning rates can be long and unknown in advance. Adaptive SGD does not need a loop in determining learning rates. On the other hand, adaptive SGD does not guarantee the "descent property" – which Backtracking line search enjoys – which is that formula_85 for all n. If the gradient of the cost function is globally Lipschitz continuous, with Lipschitz constant L, and learning rate is chosen of the order 1/L, then the standard version of SGD is a special case of backtracking line search.


title: Stochastic gradient descent

text: A stochastic analogue of the standard (deterministic) Newton–Raphson algorithm (a "second-order" method) provides an asymptotically optimal or near-optimal form of iterative optimization in the setting of stochastic approximation. A method that uses direct measurements of the Hessian matrices of the summands in the empirical risk function was developed by Byrd, Hansen, Nocedal, and Singer. However, directly determining the required Hessian matrices for optimization may not be possible in practice. Practical and theoretically sound methods for second-order versions of SGD that do not require direct Hessian information are given by Spall and others. (A less efficient method based on finite differences, instead of simultaneous perturbations, is given by Ruppert.) Another approach to the approximation Hessian matrix is replacing it with the Fisher information matrix, which transforms usual gradient to natural. These methods not requiring direct Hessian information are based on either values of the summands in the above empirical risk function or values of the gradients of the summands (i.e., the SGD inputs). In particular, second-order optimality is asymptotically achievable without direct calculation of the Hessian matrices of the summands in the empirical risk function.


title: Doomguy

text: The Doomguy (also spelt Doom Guy, as well as referred to as the Doom Marine, Doom Slayer or just the Slayer in "Doom" (2016) and "Doom Eternal") is a fictional character and the protagonist of most games in the "Doom" video game franchise of first-person shooters created by id Software. He was created by American video game designer John Romero. He was introduced as the player character in the original 1993 video game "Doom". Within the "Doom" series, Doomguy is a demon hunter space marine dressed in green combat armor who rarely speaks onscreen, and his personality and backstory were intentionally vague to reinforce his role as a player avatar. In "Doom Eternal", he is voiced by American voice actor Matthew Waterson, while Jason Kelley voices the character in that game's downloadable content "The Ancient Gods: Part Two". He has appeared in several other games developed by id Software, including "Quake Champions" and "Quake III Arena".


title: Doomguy

text: He has been featured in several other game franchises, including his likeness as a customizable skin for the Mii Gunner character in "Super Smash Bros. Ultimate", being added as an outfit in "Fall Guys", and an outfit in "Fortnite". He received mainly positive reviews, with some critics praising him for being a competent protagonist.


title: Doomguy

text: The Marine is not referred to by name in the original game. Romero described this choice as increasing player immersion: "There was never a name for the ["Doom"] marine because it's supposed to be YOU [the player]". The character sprites were created by Adrian Carmack, based on an initial sketch and clay model he made. In 2017, John Romero stated that he was the original model of the character for the cover box art. In 2020, Romero revealed that the real name of the character is Doomguy. In 2021, "Doom Eternal's" director Hugo Martin revealed that the female Doomguy was nearly added, but scrapped due to how much of an endeavor it would have been.


title: Doomguy

text: Tom Hall's original design draft, "The Doom Bible", described several planned characters, all of whom went unused in the final version. The sole non-playable character, Buddy Dacote, bore the most similarities to the original game's eventual protagonist. "Dacote" is an acronym for "Dies at conclusion of this episode", and Buddy was supposed to be killed by a boss at the end of the planned third episode. In the finished product, this nearly happens to the Marine in the final level of the first episode, but the player survives. Later, when asked, Tom Hall and John Romero confirmed that the Marine was, at least originally, a descendant of Wolfenstein protagonist B.J. Blazkowicz.


title: Doomguy

text: The unnamed protagonist of the series is a Marine who often referred to in the fan community as the "Doomguy". While id Software chose a somewhat generic, white male pictorial representation of the Marine for the box art, as well as gameplay purposes (damage feedback, story transitions), the true identity of the Doom Marine is meant to be the player themselves and so these depictions should only be considered illustrative.


title: Doomguy

text: On the box art for the original "Doom", which was done by Don Ivan Punchatz, this shows the Doomguy firing a weapon (which doesn't make an appearance in the final game) at a horde of Demons below him as one of them grabs his left wrist, while a fellow Marine (similar battle dress uniform, except in grey) in the background is rushing to catch up. This image is also used in the introduction screen of "Doom", where the Doomguy has a shotgun clutched in his left hand, while a Baron of Hell kills the grey-uniformed Marine in the background. The Doomguy appears without a helmet, in the ending to "The Ultimate Doom" episode IV "Thy Flesh Consumed", then again in the cover art of "Doom II" where he is fighting a Cyberdemon with a shotgun.


title: Doomguy

text: For the player's in-game avatar in single-player mode (also seen in the ending of "Doom II"), the Doomguy wears green armor and a light grey space helmet that conceals his facial features. Several corpses of other Marines are occasionally encountered, and they feature the same uniform as the Doomguy. In multiplayer mode there is a palette swap applied; with green and grey for players one and two in co-op, while in deathmatch there is a choice of green, red, brown and indigo/blue.