title: Micah Parsons

text: Parsons was selected in the first round (12th overall) by the Dallas Cowboys in the 2021 NFL Draft. He signed his four-year rookie contract, worth $17 million, on June 9, 2021. In response to DeMarcus Lawrence breaking his foot in practice, before week 2, Dallas converted Parsons back to his high school position of defensive end where he saw immediate success, particularly as a pass rusher. In Week 8, Parsons had 11 tackles, including four for loss in a 20-16 win over the Vikings, earning NFC Defensive Player of the Week. From Week 9 to Week 14, Parsons recorded at least 1 sack in six straight games. His 12 sacks in his first 13 career games are the fourth-most by a rookie in NFL history behind only Julius Peppers (13), Reggie White (13) and Leslie O'Neal (12.5). Parsons would finish with 84 total tackles, 13 sacks and three forced fumbles. He was voted into the Pro Bowl, named 1st Team All-Pro by the AP, and was the unanimous Defensive Rookie of the Year.


title: Micah Parsons

text: In Week 5, Parsons had two sacks, five tackles, and a tackle for loss in a 22-10 win over the Rams, earning NFC Defensive Player of the Week.


title: Micah Parsons

text: Parsons is a native of Harrisburg, Pennsylvania. He is a fan of the Philadelphia Phillies and attended Game 3 of the 2022 World Series in Philadelphia.


title: Micah Parsons

text: Parsons is a self-taught chess player, who uses the game to cultivate his game on the football field. He played in Chess.com's BlitzChamp tournament, a rapid tournament for NFL players.


title: Micah Parsons

text: On December 8, 2022, the United States announced a prisoner swap with Russia, which led to the release of WNBA basketball player, Brittney Griner from a Russian prison. In response, Parsons expressed disappointment that the US did not secure the release of Paul Whelan, a former U.S. Marine held in Russia, as part of the prisoner swap. On Twitter, Parsons wrote "Wait nah!! We left a marine?? Hell Nah." He later apologized for the comments.


title: Eleventh Doctor

text: The Eleventh Doctor is an incarnation of the Doctor, the protagonist of the BBC science fiction television programme "Doctor Who". He is played by Matt Smith in three series as well as five specials. As with previous incarnations of the Doctor, the character has also appeared in other "Doctor Who" spin-offs. Smith's portrayal of the Eleventh Doctor has been critically acclaimed.


title: Eleventh Doctor

text: Within the series' narrative, the Doctor is a centuries-old alien Time Lord from the planet Gallifrey who travels in time and space in the TARDIS, frequently with companions. At the end of life, the Doctor regenerates; as a result, the physical appearance and personality of the Doctor changes. Smith's incarnation is a quick-tempered but compassionate character whose youthful appearance is at odds with his more discerning and world-weary temperament.


title: Eleventh Doctor

text: This incarnation's main companions included feisty Scot Amy Pond (Karen Gillan), her husband Rory Williams (Arthur Darvill) and the mysterious Clara Oswald (Jenna-Louise Coleman). He also frequently appeared alongside River Song (Alex Kingston), a fellow time traveller with whom he shared a romantic storyline, and he was the last Doctor to appear alongside the long-serving companion Sarah Jane Smith (Elisabeth Sladen) prior to the actress' death, featuring in two episodes of the spin-off programme "The Sarah Jane Adventures".


title: Eleventh Doctor

text: David Tennant announced at the National Television Awards on 29 October 2008 that he would be stepping down from portraying the Doctor because he felt that the four years he spent portraying the character was enough. At the time, BBC News published that Paterson Joseph, who appeared in the "Doctor Who" episodes "Bad Wolf" and "The Parting of the Ways", was the bookmakers' favourite to succeed Tennant, followed by David Morrissey, who would be appearing in the 2008 Christmas special, "The Next Doctor". Other candidates included Sean Pertwee, son of Third Doctor actor Jon Pertwee; Russell Tovey, who portrayed Alonso Frame in the 2007 Christmas special, "Voyage of the Damned"; and James McAvoy.


title: Eleventh Doctor

text: Although Steven Moffat anticipated choosing a middle-aged actor for the new Doctor, Smith was aged 26 when cast, making him the youngest actor to portray the Doctor, three years younger than Peter Davison was at the time he began his role as the Fifth Doctor. Show producers were cautious about casting Smith because they felt that a 26-year-old could not play the Doctor adequately; BBC Wales Head of Drama Piers Wenger shared the sentiment, but noted that Smith was capable enough to play the role. Smith's casting in the role was revealed during an episode of "Doctor Who"s companion show "Doctor Who Confidential", during which he described the role as "a wonderful privilege and challenge that I hope I will thrive on".


title: Eleventh Doctor

text: The Eleventh Doctor spends most of his first full episode, "The Eleventh Hour", in the tattered remains of the Tenth Doctor's clothing, leading young Amelia Pond to nickname him "the Raggedy Man."


title: Eleventh Doctor

text: The Doctor's initial outfit, chosen within the narrative of "The Eleventh Hour" from an array of clothes found in a hospital, is a brown tweed jacket with elbow patches, bow tie, braces, blue trousers and black, ankle-high boots. The details of the outfit vary, switching from a braces and bow tie combination in red to the same in blue. In later stories, a green moleskin overcoat makes its way into the Doctor's ensemble, occasionally replacing the Harris jacket. On other occasions he does not wear a coat and wears a bow-tie and dress shirt.


title: Eleventh Doctor

text: The original tweed jacket is lost in the episode "Flesh and Stone" but replaced in "The Vampires of Venice", then becomes a plot point for the story arc for the season. In the Christmas special "A Christmas Carol", which aired the Christmas after the Eleventh Doctor's first series, he wears his most famous "Prince of Wales check" tweed jacket and a 1950s white dress suit. During season six and seven, he alternates the tweed jacket with the green moleskin overcoat. The tweed jacket makes a final appearance in "The Angels Take Manhattan".


title: Eleventh Doctor

text: After appearing in Victorian period clothing throughout "The Snowmen", the Doctor's costume changes to generally more somber colors beginning in "The Bells of Saint John" where he exchanges the monk's robes for an eggplant purple cashmere frock coat and a variety of waistcoats, and bow tie. Amy Pond's reading glasses, which were left behind with the Doctor after Amy and Rory's departure in the episode "The Angels Take Manhattan", are also occasionally worn.


title: Eleventh Doctor

text: In "The Big Bang", the Doctor briefly dons a fez, stating, "I wear a fez now, fezzes are cool." This began a running gag with "cool" headgear, including a beige Stetson, a black top hat, and the recurring fez, most of which were destroyed by River Song.


title: Eleventh Doctor

text: In an interview with "Doctor Who Magazine", Steven Moffat revealed that the Eleventh Doctor had an entirely different costume until close to the start of filming. The original look had a swashbuckling feel which "Doctor Who Magazine" editor Tom Spilsbury described as "a little like something Captain Jack Sparrow wears in the "Pirates of the Caribbean" movies". However, Matt Smith was unhappy with the costume as he felt it reflected how someone else would dress the Doctor, rather than how the Doctor would dress himself. Smith also mentioned in a 2012 interview that his Doctor was going to have a "very long black leather jacket, but it was too "Matrix"-style". The eventual costume, in particular the bow-tie, was influenced by Patrick Troughton's Second Doctor, after Matt Smith fell in love with the Troughton story "The Tomb of the Cybermen".


title: Eleventh Doctor

text: Steven Moffat describes the Eleventh Doctor as an "old man trapped in a young man's body" and Matt Smith characterizes him as someone with "a lot of blood on his hands" who copes via constant travelling and thrill-seeking.


title: Eleventh Doctor

text: The depictions of the personalities of the Tenth and Eleventh Doctors shared certain similarities e.g. both being youthful, energetic, friendly, childlike, "good boyfriend Doctors", as Steven Moffat described them and, according to Mark Gatiss "very human Doctors" when compared to other incarnations. Like his predecessor, when he first regenerates in the final scene of "The End of Time" (2010), the Eleventh Doctor complains that his incarnation is not a "ginger". He also seems surprised at his longer hair, at first mistaking his new body as female, stating, "Hair...I'm a girl!"


title: Eleventh Doctor

text: The Eleventh Doctor first appears in the final scene of "The End of Time" (2010) when his previous incarnation regenerates. Smith debuts fully in "The Eleventh Hour", where he first meets Amy Pond (Karen Gillan) as a child while investigating a mysterious crack in her wall. Many years later, Amy joins the Doctor as his travelling companion on the eve of her marriage to Rory Williams (Arthur Darvill). In "Victory of the Daleks", he is tricked into spawning a new generation of Daleks. In the two-part story "The Time of Angels" and "Flesh and Stone", he re-encounters future companion River Song (Alex Kingston) and his enemies the Weeping Angels and learns that cracks like the one in Amy's wall are erasing individuals entirely from time and space. After Amy attempts to seduce the Doctor, the Doctor recruits Rory as a second companion from "The Vampires of Venice" up until "Cold Blood", where he is killed protecting the Doctor and is erased from history. The Doctor also confronts his dark side in "Amy's Choice", where he is put through trials by a manifestation of his self-loathing, the Dream Lord (Toby Jones). In the final episodes "The Pandorica Opens" and "The Big Bang", an unknown force makes the TARDIS explode, causing the universe to collapse in on itself. Though he closes the cracks —reversing their effects and preventing the explosion— the Doctor himself is erased from history. River assists Amy in remembering the Doctor back into existence; he returns at her wedding to Rory, and the couple rejoin him as his companions. He next appears later in "Death of the Doctor", a two-part story of spin-off series "The Sarah Jane Adventures", alongside former companions Sarah Jane Smith (Elisabeth Sladen) and Jo Grant (Katy Manning), while Amy and Rory are on honeymoon.


title: Eleventh Doctor

text: Series 6 in 2011 continues to examine mysteries left unexplained at the end of Series 5. In "The Impossible Astronaut" and "Day of the Moon", Amy, Rory and River witness a future version of the Doctor murdered, which they vow to keep a secret from the present-day Doctor as they encounter hypnotic aliens called "the Silence". Eventually, Amy unknowingly lets slip that the Doctor dies in "The Almost People", when it also turns out that she is pregnant and has been kidnapped by the nefarious Madame Kovarian (Frances Barber). In "A Good Man Goes to War", the Doctor calls in old favours from across time and space to raise an army to rescue Amy from "Demons Run", an asteroid in the 52nd century being used as a base by a religious order, but is unable to rescue her child, Melody Pond. The Doctor also learns that Melody—though Rory and Amy's child—is part Time Lord due to being conceived in the TARDIS, and she will grow up to become River Song. In "Let's Kill Hitler", the Doctor encounters a younger iteration of River and learns she has been conditioned by the Silence, explained to be a religious order, to assassinate him. She nearly succeeds using a kiss of poisoned lipstick before Amy convinces her to save his life instead. The Doctor also learns the circumstances of his death from historical records on a time-travelling shape-shifting robot ship called the Teselecta. In "The God Complex", the Doctor leaves Amy and Rory on Earth when he realises Amy's apotheosis of him endangers their lives. Some time passes before the Doctor is ready to confront his death. In "The Wedding of River Song", he devises an escape by concealing himself within the Teselecta, which is disguised to look like him, to make it seem he is shot and burned as history records. In a doomed alternate reality caused by River's reluctance to shoot the Doctor, the two become married; during the ceremony, she is let in on the Doctor's original plan and helps fake and corroborate his death. The Doctor is then warned by his old friend Dorium Maldovar (Simon Fisher-Becker) that more prophecies still concern him. The Doctor learns he will be asked the oldest question in the universe, "Doctor who?", on the battlefields of Trenzalore; the Silence had intended his death to prevent this.


title: Eleventh Doctor

text: In the Christmas special "The Doctor, the Widow and the Wardrobe" (2011), the Doctor has Christmas dinner with Amy and Rory, who had been informed by River of his survival. They unite again in the Series 7 premiere "Asylum of the Daleks" (2012), in which the Doctor is erased from the Daleks' memory banks due to the actions of Oswin Oswald (Jenna Coleman), a young woman turned Dalek who had retained her human mind; she subsequently dies. The Doctor then takes Amy and Rory on several adventures, eventually taking them back on as full-time companions in "The Power of Three" before losing them during the events of "The Angels Take Manhattan". The Doctor subsequently "retires" to a secluded lifestyle in Victorian London, until the 2012 Christmas special "The Snowmen," when he is inspired to save the world by a barmaid/governess called Clara (Coleman) who he considers an ideal companion. Mid-adventure, Clara dies, and when the Doctor sees her tombstone, reading "Clara Oswin Oswald", he realizes that Oswin and Clara are the same woman in different moments of time. He resolves to find her again in another era. The Doctor succeeds in "The Bells of Saint John", saving a present-day version of Clara Oswald from agents of the Great Intelligence. He takes her as his companion and attempts to solve the mystery of "the Impossible Girl". The Doctor eventually gets his answer in "The Name of the Doctor" when he is forced by the Great Intelligence to go to Trenzalore, revealed to be the planet on which the Doctor will die. Within the Doctor's tomb, the Great Intelligence uses the dead Doctor's remnants—his disembodied "timestream"—to spread himself across the Doctor's history, turning his victories into defeats. Clara pursues him and is scattered throughout the Doctor's timeline creating Oswin Oswald and Clara Oswin Oswald among numerous other incarnations who undo the Great Intelligence's work. The Doctor has a mournful conversation with River's apparition, giving her closure before entering the timeline to retrieve Clara. However, once he saves her, the Doctor is forced to reveal the existence of a previous incarnation (John Hurt) who broke the promise represented by the name "Doctor" during the Time War of his past.


title: Eleventh Doctor

text: In the show's 50th anniversary special, while investigating a strange occurrence beneath London's National Gallery, the Doctor encounters his past incarnation who fought in the Time War (John Hurt) as well as his immediate previous incarnation (David Tennant). Though the older Doctors berate the 'War Doctor' for his killing both Time Lords and Daleks with a sentient weapon known as the Moment, they ultimately choose to support his decision and forgive themselves for this past atrocity. Led by the Moment into the midst of the Time War, the Doctors realize they have the potential to change its outcome and enlist the aid of their previous incarnations in an uncertain bid to save Gallifrey from destruction. They place the planet in stasis and transport it to a pocket universe, making it appear to be destroyed. As an effect of time travel, only the Eleventh Doctor will remember saving Gallifrey; he learns from a cryptic curator (played by Tom Baker) that his plan worked. In "The Time of the Doctor," the Doctor is lured to what he learns is the planet Trenzalore to decode what he discovers is a message from the displaced Time Lords through the last remaining crack in the universe: the oldest question in the universe, "Doctor who?". Learning that the verification of his identity would allow the Time Lords to return, the Doctor finds out that the signal caught the attention of an assortment of his enemies, who wish to prevent Gallifrey's return, and the powerful Church of the Papal Mainframe, who wish to destroy the planet and avoid the possibility of a new Time War. After attempting to send Clara back to her time, the Doctor spends centuries defending the planet from alien incursions. During this time, a faction of the Church led by the Silence breaks away and attempts to avert these events by destroying the Doctor earlier in his timeline, as seen in series 5 and 6. The Doctor also reveals to Clara he has no regenerations remaining and will likely die in the siege. The siege escalates into all-out war and after centuries pass, only the Daleks remain. Though the heavily aged Doctor anticipates his predestined death on the battlefields of Trenzalore, Clara convinces the Time Lords to give the Doctor a new regeneration cycle as he uses a fiery blast of regenerative energy to destroy the Dalek mothership. The Doctor regains his youth before retiring to the TARDIS to complete the process. He hallucinates a final farewell to Amy Pond and delivers a eulogy to his present incarnation, before abruptly completing his transition into the Twelfth Doctor (Peter Capaldi). He made a reappearance in "Deep Breath" (2014). While adjusting to the new Doctor, Clara receives a phone call from the Eleventh Doctor made moments prior to their final meeting. He asks her to help his new self and not to be afraid of him.


title: Eleventh Doctor

text: Like the Tenth Doctor, the Eleventh and Amy (and later Rory) appear in New Series Adventures novels in 2010. The first of these is "Apollo 23" by Justin Richards, as well as the "Decide Your Destiny" series of interactive novels. The character also appears in comic books published in "Doctor Who Magazine", "Doctor Who Adventures", and he took over from the Tenth Doctor in IDW Publishing's "Doctor Who" series before BBC Worldwide awarded the license to Titan Magazines. He'll continue to appear in these, as will the Tenth and Twelfth Doctors in their own stories. He appeared in the crossover series "", where he was working with the crew of the "Enterprise"-D to defeat a Borg/Cybermen alliance.


title: Eleventh Doctor

text: The Eleventh Doctor also appears in a series of audiobooks. The first release of these is "The Runaway Train" by Oli Smith".


title: Eleventh Doctor

text: To tie into the 50th anniversary of Doctor Who in 2013, Big Finish and AudioGO produced "The Time Machine", an audiobook story starring the Eleventh Doctor and narrated by Jenna Coleman. The Eleventh Doctor made his next audio appearance in 2016 for "The Churchill Years" - starring Ian McNeice narrating in-character as Winston Churchill - and its second series in 2018. He also appeared alongside the Tenth Doctor in "The Jago and Litefoot Revival" in 2017, narrated by Trevor Baxter and Christopher Benjamin.


title: Eleventh Doctor

text: In the absence of Matt Smith, voice actor and impressionist Jacob Dudman has voiced the Eleventh Doctor in multiple Big Finish productions, including the ongoing range "", which debuted in August 2018. In the first volume, Dudman voices the Doctor and serves as narrator; the second volume, due for release in September 2021, will feature Dudman as the Doctor in full-cast dramas with no narrator. Dudman also voices the Eleventh Doctor for a cameo appearance opposite the Fifth Doctor in "" and a pair of Short Trips in which the Doctor reunites with Jo Grant and meets his next incarnation, also voiced by Dudman.


title: Eleventh Doctor

text: The Eleventh Doctor is the first of the Doctors to appear in full-on action adventure games. "" is composed of four stories ("episodes"), produced alongside the 2010 series. Smith and Gillan lent their voices and likenesses. The first, "City of the Daleks", carries on from the TV episode "Victory of the Daleks" and is a stealth and puzzle game set in 1960s Earth and the Dalek planet of Skaro. The second, "Blood of the Cybermen", is the Eleventh Doctor and Amy's first Cyberman story. The third episode is the video game "TARDIS", and the fourth is "The Shadows of the Vashta Nerada", featuring the titular enemy return in an underwater setting. The fifth Adventure Game "The Gunpowder Plot" was released on 31 October 2011, again featuring Matt Smith's voice.


title: Eleventh Doctor

text: In May 2012, "The Eternity Clock" was released for PlayStation 3, PlayStation Vita, and PC, starring Matt Smith and Alex Kingston.


title: Eleventh Doctor

text: Matt Smith's portrayal of the Doctor was met with critical acclaim. Following the broadcast of "The Eleventh Hour", "The Daily Telegraph" reviewer Benji Wilson opined that "the Doctor is meant to be a mad alien, and Smith looks like one before he even opens his mouth", stating "it was ridiculous but it felt right: mad, alien, brand new but very old. A+ to the casting director. A+ to Smith". In "The Guardian", Daniel Martin concurred, stating that "Smith inhabits the role from the moment he pops up...[he] carries off the youthful vigour of a new body and the ancient professorial wisdom with easy panache".


title: Eleventh Doctor

text: Martin Anderson of "Shadowlocked" claimed him to be the best Doctor since "Tom Baker practically redefined the character in the 1970s". Smith's performance in "Flesh and Stone" was acclaimed by Gavin Fuller of "The Daily Telegraph", who noted that "Matt Smith's 'quick-paced delivery' is 'a major facet' of the success of the current series." In his review of "The Big Bang", Fuller once again praised Smith's acting. "Matt Smith was superb in his scenes where the Doctor sacrifices himself in the Pandorica to rescue the multiverse". Kyle Anderson of Nerdist wrote "I don't know about you all, but the Eleventh Doctor was MY Doctor." Dan Martin of "The Guardian" also claimed Smith as "my ultimate Doctor."


title: RNA

text: Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid (DNA) are nucleic acids. Along with lipids, proteins, and carbohydrates, nucleic acids constitute one of the four major macromolecules essential for all known forms of life. Like DNA, RNA is assembled as a chain of nucleotides, but unlike DNA, RNA is found in nature as a single strand folded onto itself, rather than a paired double strand. Cellular organisms use messenger RNA (mRNA) to convey genetic information (using the nitrogenous bases of guanine, uracil, adenine, and cytosine, denoted by the letters G, U, A, and C) that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome.


title: RNA

text: Some RNA molecules play an active role within cells by catalyzing biological reactions, controlling gene expression, or sensing and communicating responses to cellular signals. One of these active processes is protein synthesis, a universal function in which RNA molecules direct the synthesis of proteins on ribosomes. This process uses transfer RNA (tRNA) molecules to deliver amino acids to the ribosome, where ribosomal RNA (rRNA) then links amino acids together to form coded proteins.


title: RNA

text: Like DNA, most biologically active RNAs, including mRNA, tRNA, rRNA, snRNAs, and other non-coding RNAs, contain self-complementary sequences that allow parts of the RNA to fold and pair with itself to form double helices. Analysis of these RNAs has revealed that they are highly structured. Unlike DNA, their structures do not consist of long double helices, but rather collections of short helices packed together into structures akin to proteins.


title: RNA

text: In this fashion, RNAs can achieve chemical catalysis (like enzymes). For instance, determination of the structure of the ribosome—an RNA-protein complex that catalyzes peptide bond formation—revealed that its active site is composed entirely of RNA.


title: RNA

text: Each nucleotide in RNA contains a ribose sugar, with carbons numbered 1' through 5'. A base is attached to the 1' position, in general, adenine (A), cytosine (C), guanine (G), or uracil (U). Adenine and guanine are purines, cytosine and uracil are pyrimidines. A phosphate group is attached to the 3' position of one ribose and the 5' position of the next. The phosphate groups have a negative charge each, making RNA a charged molecule (polyanion). The bases form hydrogen bonds between cytosine and guanine, between adenine and uracil and between guanine and uracil. However, other interactions are possible, such as a group of adenine bases binding to each other in a bulge,


title: RNA

text: An important structural component of RNA that distinguishes it from DNA is the presence of a hydroxyl group at the 2' position of the ribose sugar. The presence of this functional group causes the helix to mostly take the A-form geometry, although in single strand dinucleotide contexts, RNA can rarely also adopt the B-form most commonly observed in DNA. The A-form geometry results in a very deep and narrow major groove and a shallow and wide minor groove. A second consequence of the presence of the 2'-hydroxyl group is that in conformationally flexible regions of an RNA molecule (that is, not involved in formation of a double helix), it can chemically attack the adjacent phosphodiester bond to cleave the backbone.


title: RNA

text: RNA is transcribed with only four bases (adenine, cytosine, guanine and uracil), but these bases and attached sugars can be modified in numerous ways as the RNAs mature. Pseudouridine (Ψ), in which the linkage between uracil and ribose is changed from a C–N bond to a C–C bond, and ribothymidine (T) are found in various places (the most notable ones being in the TΨC loop of tRNA). Another notable modified base is hypoxanthine, a deaminated adenine base whose nucleoside is called inosine (I). Inosine plays a key role in the wobble hypothesis of the genetic code.


title: RNA

text: There are more than 100 other naturally occurring modified nucleosides. The greatest structural diversity of modifications can be found in tRNA, while pseudouridine and nucleosides with 2'-O-methylribose often present in rRNA are the most common. The specific roles of many of these modifications in RNA are not fully understood. However, it is notable that, in ribosomal RNA, many of the post-transcriptional modifications occur in highly functional regions, such as the peptidyl transferase center and the subunit interface, implying that they are important for normal function.


title: RNA

text: The functional form of single-stranded RNA molecules, just like proteins, frequently requires a specific tertiary structure. The scaffold for this structure is provided by secondary structural elements that are hydrogen bonds within the molecule. This leads to several recognizable "domains" of secondary structure like hairpin loops, bulges, and internal loops. In order create, i.e., design, a RNA for any given secondary structure, two or three bases would not be enough, but four bases are enough. This is likely why nature has "chosen" a four base alphabet: less than four does not allow to create all structures, while more than four bases are not necessary. Since RNA is charged, metal ions such as Mg are needed to stabilise many secondary and tertiary structures.


title: RNA

text: The naturally occurring enantiomer of RNA is -RNA composed of -ribonucleotides. All chirality centers are located in the -ribose. By the use of -ribose or rather -ribonucleotides, -RNA can be synthesized. -RNA is much more stable against degradation by RNase.


title: RNA

text: Like other structured biopolymers such as proteins, one can define topology of a folded RNA molecule. This is often done based on arrangement of intra-chain contacts within a folded RNA, termed as circuit topology.


title: RNA

text: Synthesis of RNA is usually catalyzed by an enzyme—RNA polymerase—using DNA as a template, a process known as transcription. Initiation of transcription begins with the binding of the enzyme to a promoter sequence in the DNA (usually found "upstream" of a gene). The DNA double helix is unwound by the helicase activity of the enzyme. The enzyme then progresses along the template strand in the 3’ to 5’ direction, synthesizing a complementary RNA molecule with elongation occurring in the 5’ to 3’ direction. The DNA sequence also dictates where termination of RNA synthesis will occur.


title: RNA

text: Primary transcript RNAs are often modified by enzymes after transcription. For example, a poly(A) tail and a 5' cap are added to eukaryotic pre-mRNA and introns are removed by the spliceosome.


title: RNA

text: There are also a number of RNA-dependent RNA polymerases that use RNA as their template for synthesis of a new strand of RNA. For instance, a number of RNA viruses (such as poliovirus) use this type of enzyme to replicate their genetic material. Also, RNA-dependent RNA polymerase is part of the RNA interference pathway in many organisms.


title: RNA

text: Messenger RNA (mRNA) is the RNA that carries information from DNA to the ribosome, the sites of protein synthesis (translation) in the cell. The mRNA is a copy of DNA. The coding sequence of the mRNA determines the amino acid sequence in the protein that is produced. However, many RNAs do not code for protein (about 97% of the transcriptional output is non-protein-coding in eukaryotes).


title: RNA

text: These so-called non-coding RNAs ("ncRNA") can be encoded by their own genes (RNA genes), but can also derive from mRNA introns. The most prominent examples of non-coding RNAs are transfer RNA (tRNA) and ribosomal RNA (rRNA), both of which are involved in the process of translation. There are also non-coding RNAs involved in gene regulation, RNA processing and other roles. Certain RNAs are able to catalyse chemical reactions such as cutting and ligating other RNA molecules, and the catalysis of peptide bond formation in the ribosome; these are known as ribozymes.


title: RNA

text: According to the length of RNA chain, RNA includes small RNA and long RNA. Usually, small RNAs are shorter than 200 nt in length, and long RNAs are greater than 200 nt long. Long RNAs, also called large RNAs, mainly include long non-coding RNA (lncRNA) and mRNA. Small RNAs mainly include 5.8S ribosomal RNA (rRNA), 5S rRNA, transfer RNA (tRNA), microRNA (miRNA), small interfering RNA (siRNA), small nucleolar RNA (snoRNAs), Piwi-interacting RNA (piRNA), tRNA-derived small RNA (tsRNA) and small rDNA-derived RNA (srRNA).


title: RNA

text: There are certain exceptions as in the case of the 5S rRNA of the members of the genus Halococcus (Archaea), which have an insertion, thus increasing its size.


title: RNA

text: Messenger RNA (mRNA) carries information about a protein sequence to the ribosomes, the protein synthesis factories in the cell. It is coded so that every three nucleotides (a codon) corresponds to one amino acid. In eukaryotic cells, once precursor mRNA (pre-mRNA) has been transcribed from DNA, it is processed to mature mRNA. This removes its introns—non-coding sections of the pre-mRNA. The mRNA is then exported from the nucleus to the cytoplasm, where it is bound to ribosomes and translated into its corresponding protein form with the help of tRNA. In prokaryotic cells, which do not have nucleus and cytoplasm compartments, mRNA can bind to ribosomes while it is being transcribed from DNA. After a certain amount of time, the message degrades into its component nucleotides with the assistance of ribonucleases.


title: RNA

text: Transfer RNA (tRNA) is a small RNA chain of about 80 nucleotides that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. It has sites for amino acid attachment and an anticodon region for codon recognition that binds to a specific sequence on the messenger RNA chain through hydrogen bonding.


title: RNA

text: Ribosomal RNA (rRNA) is the catalytic component of the ribosomes. The rRNA is the component of the ribosome that hosts translation. Eukaryotic ribosomes contain four different rRNA molecules: 18S, 5.8S, 28S and 5S rRNA. Three of the rRNA molecules are synthesized in the nucleolus, and one is synthesized elsewhere. In the cytoplasm, ribosomal RNA and protein combine to form a nucleoprotein called a ribosome. The ribosome binds mRNA and carries out protein synthesis. Several ribosomes may be attached to a single mRNA at any time. Nearly all the RNA found in a typical eukaryotic cell is rRNA.


title: RNA

text: Transfer-messenger RNA (tmRNA) is found in many bacteria and plastids. It tags proteins encoded by mRNAs that lack stop codons for degradation and prevents the ribosome from stalling.


title: RNA

text: The earliest known regulators of gene expression were proteins known as repressors and activators – regulators with specific short binding sites within enhancer regions near the genes to be regulated.  Later studies have shown that RNAs also regulate genes. There are several kinds of RNA-dependent processes in eukaryotes regulating the expression of genes at various points, such as RNAi repressing genes post-transcriptionally, long non-coding RNAs shutting down blocks of chromatin epigenetically, and enhancer RNAs inducing increased gene expression. Bacteria and archaea have also been shown to use regulatory RNA systems such as bacterial small RNAs and CRISPR. Fire and Mello were awarded the 2006 Nobel Prize in Physiology or Medicine for discovering microRNAs (miRNAs), specific short RNA molecules that can base-pair with mRNAs.


title: RNA

text: Post-transcriptional expression levels of many genes can be controlled by RNA interference, in which miRNAs, specific short RNA molecules, pair with mRNA regions and target them for degradation. This antisense-based process involves steps that first process the RNA so that it can base-pair with a region of its target mRNAs. Once the base pairing occurs, other proteins direct the mRNA to be destroyed by nucleases.


title: RNA

text: Next to be linked to regulation were Xist and other long noncoding RNAs associated with X chromosome inactivation.  Their roles, at first mysterious, were shown by Jeannie T. Lee and others to be the silencing of blocks of chromatin via recruitment of Polycomb complex so that messenger RNA could not be transcribed from them. Additional lncRNAs, currently defined as RNAs of more than 200 base pairs that do not appear to have coding potential, have been found associated with regulation of stem cell pluripotency and cell division.


title: RNA

text: The third major group of regulatory RNAs is called enhancer RNAs.  It is not clear at present whether they are a unique category of RNAs of various lengths or constitute a distinct subset of lncRNAs.  In any case, they are transcribed from enhancers, which are known regulatory sites in the DNA near genes they regulate.  They up-regulate the transcription of the gene(s) under control of the enhancer from which they are transcribed.


title: RNA

text: At first, regulatory RNA was thought to be a eukaryotic phenomenon, a part of the explanation for why so much more transcription in higher organisms was seen than had been predicted. But as soon as researchers began to look for possible RNA regulators in bacteria, they turned up there as well, termed as small RNA (sRNA). Currently, the ubiquitous nature of systems of RNA regulation of genes has been discussed as support for the RNA World theory. Bacterial small RNAs generally act via antisense pairing with mRNA to down-regulate its translation, either by affecting stability or affecting cis-binding ability. Riboswitches have also been discovered. They are cis-acting regulatory RNA sequences acting allosterically. They change shape when they bind metabolites so that they gain or lose the ability to bind chromatin to regulate expression of genes.


title: RNA

text: Archaea also have systems of regulatory RNA. The CRISPR system, recently being used to edit DNA "in situ", acts via regulatory RNAs in archaea and bacteria to provide protection against virus invaders.


title: RNA

text: Introns are spliced out of pre-mRNA by spliceosomes, which contain several small nuclear RNAs (snRNA), or the introns can be ribozymes that are spliced by themselves.


title: RNA

text: In eukaryotes, modifications of RNA nucleotides are in general directed by small nucleolar RNAs (snoRNA; 60–300 nt), found in the nucleolus and cajal bodies. snoRNAs associate with enzymes and guide them to a spot on an RNA by basepairing to that RNA. These enzymes then perform the nucleotide modification. rRNAs and tRNAs are extensively modified, but snRNAs and mRNAs can also be the target of base modification. RNA can also be methylated.


title: RNA

text: Like DNA, RNA can carry genetic information. RNA viruses have genomes composed of RNA that encodes a number of proteins. The viral genome is replicated by some of those proteins, while other proteins protect the genome as the virus particle moves to a new host cell. Viroids are another group of pathogens, but they consist only of RNA, do not encode any protein and are replicated by a host plant cell's polymerase.


title: RNA

text: Reverse transcribing viruses replicate their genomes by reverse transcribing DNA copies from their RNA; these DNA copies are then transcribed to new RNA. Retrotransposons also spread by copying DNA and RNA from one another, and telomerase contains an RNA that is used as template for building the ends of eukaryotic chromosomes.


title: RNA

text: Double-stranded RNA (dsRNA) is RNA with two complementary strands, similar to the DNA found in all cells, but with the replacement of thymine by uracil and the adding of one oxygen atom. dsRNA forms the genetic material of some viruses (double-stranded RNA viruses). Double-stranded RNA, such as viral RNA or siRNA, can trigger RNA interference in eukaryotes, as well as interferon response in vertebrates. In Eukaryotes, Double-stranded RNA (dsRNA) plays a role in the activation of the innate immune system against viral infections.


title: RNA

text: In the late 1970s, it was shown that there is a single stranded covalently closed, i.e. circular form of RNA expressed throughout the animal and plant kingdom (see circRNA). circRNAs are thought to arise via a "back-splice" reaction where the spliceosome joins a upstream 3' acceptor to a downstream 5' donor splice site. So far the function of circRNAs is largely unknown, although for few examples a microRNA sponging activity has been demonstrated.


title: RNA

text: Research on RNA has led to many important biological discoveries and numerous Nobel Prizes. Nucleic acids were discovered in 1868 by Friedrich Miescher, who called the material 'nuclein' since it was found in the nucleus. It was later discovered that prokaryotic cells, which do not have a nucleus, also contain nucleic acids. The role of RNA in protein synthesis was suspected already in 1939. Severo Ochoa won the 1959 Nobel Prize in Medicine (shared with Arthur Kornberg) after he discovered an enzyme that can synthesize RNA in the laboratory. However, the enzyme discovered by Ochoa (polynucleotide phosphorylase) was later shown to be responsible for RNA degradation, not RNA synthesis. In 1956 Alex Rich and David Davies hybridized two separate strands of RNA to form the first crystal of RNA whose structure could be determined by X-ray crystallography.


title: RNA

text: The sequence of the 77 nucleotides of a yeast tRNA was found by Robert W. Holley in 1965, winning Holley the 1968 Nobel Prize in Medicine (shared with Har Gobind Khorana and Marshall Nirenberg).


title: RNA

text: In the early 1970s, retroviruses and reverse transcriptase were discovered, showing for the first time that enzymes could copy RNA into DNA (the opposite of the usual route for transmission of genetic information). For this work, David Baltimore, Renato Dulbecco and Howard Temin were awarded a Nobel Prize in 1975.


title: RNA

text: In 1976, Walter Fiers and his team determined the first complete nucleotide sequence of an RNA virus genome, that of bacteriophage MS2.


title: RNA

text: In 1977, introns and RNA splicing were discovered in both mammalian viruses and in cellular genes, resulting in a 1993 Nobel to Philip Sharp and Richard Roberts.


title: RNA

text: Catalytic RNA molecules (ribozymes) were discovered in the early 1980s, leading to a 1989 Nobel award to Thomas Cech and Sidney Altman. In 1990, it was found in "Petunia" that introduced genes can silence similar genes of the plant's own, now known to be a result of RNA interference.


title: RNA

text: At about the same time, 22 nt long RNAs, now called microRNAs, were found to have a role in the development of "C. elegans".


title: RNA

text: Studies on RNA interference gleaned a Nobel Prize for Andrew Fire and Craig Mello in 2006, and another Nobel was awarded for studies on the transcription of RNA to Roger Kornberg in the same year. The discovery of gene regulatory RNAs has led to attempts to develop drugs made of RNA, such as siRNA, to silence genes. Adding to the Nobel prizes awarded for research on RNA in 2009 it was awarded for the elucidation of the atomic structure of the ribosome to Venki Ramakrishnan, Thomas A. Steitz, and Ada Yonath.


title: RNA

text: In 1968, Carl Woese hypothesized that RNA might be catalytic and suggested that the earliest forms of life (self-replicating molecules) could have relied on RNA both to carry genetic information and to catalyze biochemical reactions—an RNA world. In May 2022, scientists reported that RNA was found to be formed spontaneously on prebiotic basalt lava glass which is presumed to have been abundantly available on the early Earth.


title: RNA

text: In March 2015, complex DNA and RNA nucleotides, including uracil, cytosine and thymine, were reportedly formed in the laboratory under outer space conditions, using starter chemicals, such as pyrimidine, an organic compound commonly found in meteorites. Pyrimidine, like polycyclic aromatic hydrocarbons (PAHs), is one of the most carbon-rich compounds found in the Universe and may have been formed in red giants or in interstellar dust and gas clouds. In July 2022, astronomers reported the discovery of massive amounts of s, including possible RNA precursors, in the Galactic Center of the Milky Way Galaxy.


title: Twenty20

text: Twenty20 (T20) is a shortened game format of cricket. At the professional level, it was introduced by the England and Wales Cricket Board (ECB) in 2003 for the inter-county competition. In a Twenty20 game, the two teams have a single innings each, which is restricted to a maximum of 20 overs. Together with first-class and List A cricket, Twenty20 is one of the three current forms of cricket recognised by the International Cricket Council (ICC) as being at the highest international or domestic level.


title: Twenty20

text: A typical Twenty20 game is completed in about two and a half hours, with each innings lasting around 70 minutes and an official 10-minute break between the innings. This is much shorter than previous forms of the game, and is closer to the timespan of other popular team sports. It was introduced to create a fast-paced game that would be attractive to spectators at the ground and viewers on television.


title: Twenty20

text: The game has succeeded in spreading around the cricket world. On most international tours there is at least one Twenty20 match and all Test-playing nations have a domestic cup competition.


title: Twenty20

text: When the Benson & Hedges Cup ended in 2002, the ECB needed another one-day competition to fill its place. Cricketing authorities were looking to boost the game's popularity with the younger generation in response to dwindling crowds and reduced sponsorship. It was intended to deliver fast-paced, exciting cricket accessible to thousands of fans who were put off by the longer versions of the game. Stuart Robertson, the marketing manager of the ECB, proposed a 20-over-per-innings game, invented by New Zealand cricketer Martin Crowe, to county chairmen in 2001 and they voted 11–7 in favour of adopting the new format.


title: Twenty20

text: The first official Twenty20 matches were played on 13 June 2003 between the English counties in the Twenty20 Cup. The first season of Twenty20 in England was a relative success, with the Surrey Lions defeating the Warwickshire Bears by nine wickets in the final to claim the title. The first Twenty20 match held at Lord's, on 15 July 2004 between Middlesex and Surrey, attracted a crowd of 27,509, the highest attendance for any county cricket game at the ground – other than a one-day final – since 1953.


title: Twenty20

text: Thirteen teams from different parts of the country participated in Pakistan's inaugural competition in 2004, with the Faisalabad Wolves the first winners. On 12 January 2005 Australia's first Twenty20 game was played at the WACA Ground between the Western Warriors and the Victorian Bushrangers. It drew a sell-out crowd of 20,000, which was the first one in nearly 25 years.


title: Twenty20

text: Starting on 11 July 2006, 19 West Indies regional teams competed in what was named the Stanford 20/20 tournament. The event was financially backed by billionaire Allen Stanford, who gave at least US$28,000,000 in funding money. It was intended that the tournament would be an annual event. Guyana won the inaugural event, defeating Trinidad and Tobago by five wickets, securing US$1,000,000 in prize money.


title: Twenty20

text: On 5 January 2007 the Queensland Bulls played the New South Wales Blues at The Gabba, Brisbane. An unexpected 16,000 fans turned up on the day to buy tickets, causing Gabba staff to throw open gates and grant many fans free entry. Attendance reached 27,653. For the February 2008 Twenty20 match between Australia and India, 85,824 people attended the match at the Melbourne Cricket Ground, involving the Twenty20 World Champions against the ODI World Champions.


title: Twenty20

text: The Stanford Super Series was held in October 2008 between three teams. The respective winners of the English and Caribbean Twenty20 competitions, Middlesex and Trinidad and Tobago, and a Stanford Superstars team formed from West Indies domestic players. Trinidad and Tobago won the competition, securing US$280,000 prize money. On 1 November, the Stanford Superstars played England in what was expected to be the first of five fixtures in as many years with the winner claiming US$20,000,000 in each match. The Stanford Superstars won the first match, but no further fixtures were held as Allen Stanford was charged with fraud in 2009.


title: Twenty20

text: Several T20 leagues started after the popularity of the 2007 ICC World Twenty20. The Board of Control for Cricket in India started the Indian Premier League, which is now the largest cricket league, in 2008, which utilizes the North American sports franchise system with ten teams in major Indian cities. In September 2017, the broadcasting and digital rights for the next five years (2018–2022) of the IPL were sold to Star India for US$2.55 billion, making it one of the world's most lucrative sports league per match. The IPL has seen a spike in its brand valuation to US$5.3 billion after the 10th edition, according to global valuation and corporate finance advisor Duff & Phelps.


title: Twenty20

text: The Big Bash League, Bangladesh Premier League, Pakistan Super League, Caribbean Premier League, and Afghanistan Premier League started thereafter, following similar formulae, and remained popular with the fans. The Women's Big Bash League was started in 2015 by Cricket Australia, while the Kia Super League was started in England and Wales in 2016. The Mzansi Super League in South Africa was started in 2018.


title: Twenty20

text: Several T20 leagues follow the general format of having a group stage followed by a Page playoff system among the top four teams where:


title: Twenty20

text: In the Big Bash League, there is an additional match to determine which of the fourth- or fifth-placed teams will qualify to be in the top four.


title: Twenty20

text: The first Twenty20 International match was held on 5 August 2004 between the England and New Zealand women's teams, with New Zealand winning by nine runs.


title: Twenty20

text: On 17 February 2005 Australia defeated New Zealand in the first men's international Twenty20 match, played at Eden Park in Auckland. The game was played in a light-hearted manner – both sides turned out in kit similar to that worn in the 1980s, the New Zealand team's a direct copy of that worn by the Beige Brigade. Some of the players also sported moustaches or beards and hairstyles popular in the 1980s, taking part in a competition amongst themselves for "best retro look", at the request of the Beige Brigade. Australia won the game comprehensively, and as the result became obvious towards the end of the NZ innings, the players and umpires took things less seriously: Glenn McGrath jokingly replayed the Trevor Chappell underarm incident from a 1981 ODI between the two sides, and Billy Bowden showed him a mock red card (red cards are not normally used in cricket) in response.


title: Twenty20

text: The first Twenty20 international in England was played between England and Australia at the Rose Bowl in Hampshire on 13 June 2005, which England won by a margin of 100 runs, a record victory which lasted until 2007.


title: Twenty20

text: On 9 January 2006 Australia and South Africa met in the first international Twenty20 game in Australia. In a first, each player's nickname appeared on the back of his uniform, rather than his surname. The international match drew a crowd of 38,894 people at The Gabba.


title: Twenty20

text: On 16 February 2006 New Zealand defeated West Indies in a tie-breaking bowl-out 3–0; 126 runs were scored apiece in the game proper. The game was the last international match played by Chris Cairns.


title: Twenty20

text: The ICC has declared that it sees T20 as the optimal format for globalizing the game, and in 2018, announced that it will give international status to all T20 cricket matches played between its member nations. This resulted in a significant leap in the number of T20I matches played across the world.


title: Twenty20

text: Every two years an ICC World Twenty20 tournament is to take place, except in the event of an ICC Cricket World Cup being scheduled in the same year, in which case it will be held the year before. The first tournament was in 2007 in South Africa where India defeated Pakistan in the final. Two Associate teams had played in the first tournament, selected through the 2007 ICC World Cricket League Division One, a 50-over competition. In December 2007 it was decided to hold a qualifying tournament with a 20-over format to better prepare the teams. With six participants, two would qualify for the 2009 World Twenty20 and would each receive $250,000 in prize money. The second tournament was won by Pakistan, who beat Sri Lanka by eight wickets in England on 21 June 2009. The 2010 ICC World Twenty20 tournament was held in the West Indies in May 2010, where England defeated Australia by seven wickets. The 2012 ICC World Twenty20 was won by the West Indies, by defeating Sri Lanka at the finals. It was the first time in cricket history when a T20 World Cup tournament took place in an Asian country. The 2014 ICC World Twenty20 was won by Sri Lanka, by defeating India at the finals, where the tournament was held in Bangladesh. The 2016 ICC World Twenty20 was won by West Indies. In July 2020, the ICC announced that both the 2020 and 2021 editions had been postponed by one year due to the COVID-19 pandemic.


title: Twenty20

text: In June 2021, the ICC expanded the Twenty20 World Cup from 16 to 20 teams starting from the 2024 edition onwards.


title: Twenty20

text: Twenty20 cricket is claimed to have resulted in a more athletic and explosive form of cricket. Indian fitness coach Ramji Srinivasan declared in an interview with the Indian fitness website Takath.com that Twenty20 had "raised the bar" in terms of fitness levels for all players, demanding higher levels of strength, speed, agility and reaction time from all players regardless of role in the team. Matthew Hayden credited retirement from international cricket with aiding his performance in general and fitness in particular in the Indian Premier League.


title: Twenty20

text: In June 2009, speaking at the annual Cowdrey Lecture at Lord's, former Australian wicketkeeper Adam Gilchrist pushed for Twenty20 to be made an Olympic sport. "It would," he said, "be difficult to see a better, quicker or cheaper way of spreading the game throughout the world." In a similar vein, several commentators have noted that the T20 format has been embraced by many Associate members of the ICC partly because it is more financially viable to play.


title: Twenty20

text: Former Australian captain Ricky Ponting, on the other hand, has criticized Twenty20 as being detrimental to Test cricket and for hampering batsmen's scoring skills and concentration. Former Australian captain Greg Chappell made similar complaints, fearing that young players would play too much T20 and not develop their batting skills fully, while former England player Alex Tudor feared the same for bowling skills.


title: Twenty20

text: Former West Indies captains Clive Lloyd, Michael Holding and Garfield Sobers criticised Twenty20 for its role in discouraging players from representing their test cricket national side, with many West Indies players like Chris Gayle, Sunil Narine and Dwayne Bravo preferring instead to play in a Twenty20 franchise elsewhere in the world and make far more money.


title: Twenty20

text: Twenty20 match format is a form of limited overs cricket in that it involves two teams, each with a single innings. The key feature is that each team bats for a maximum of 20 overs (120 legal balls). The batting team members do not arrive from and depart to traditional dressing rooms, but come and go from a bench (typically a row of chairs) visible in the playing arena, analogous to association football's technical area or a baseball dugout.


title: Twenty20

text: Currently, if the match ends with the scores tied and there must be a winner, the tie is broken with a one-over-per-side Eliminator or Super Over:


title: Twenty20

text: Each team nominates three batsmen and one bowler to play a one-over-per-side "mini-match". The team which bats second in the match bats first in the Super Over. In turn, each side bats one over bowled by the one nominated opposition bowler, with their innings over if they lose two wickets before the over is completed. The side with the higher score from their Super Over wins.


title: Twenty20

text: In the Australian domestic competition the Big Bash League, the Super Over is played slightly differently, with no two-wicket limit, and if the Super Over is also tied then a "countback" is used, with scores after the fifth ball for each team being used to determine the result. If it is still tied, then the countback goes to four balls, and so on. The latest Super Over to decide a match was between the Sydney Sixers and the Brisbane Heat on 25 January 2017, in the Big Bash League at the Brisbane Cricket Ground, with the Sixers winning 0/22 to 0/15 in the Super Over after tying on 164.


title: Twenty20

text: Women's and men's Twenty20 Internationals have been played since 2004 and 2005 respectively. To date, 76 nations have played the format, including all Test-playing nations.


title: Twenty20

text: In November 2011, the ICC released the first Twenty20 International rankings for the men's game, based on the same system as the Test and ODI rankings. The rankings cover a two- to three-year period, with matches since the most recent 1 August weighted fully, matches in the preceding 12 months weighted two-thirds, and matches in the 12 months preceding that weighted one-third. To qualify for the rankings, teams must have played at least eight Twenty20 Internationals in the ranking period.


title: Twenty20

text: Until 2018, the ICC did not maintain a separate Twenty20 ranking for the women's game, instead aggregating performance over all three forms of the game into one overall women's teams ranking. However, in October, the ICC announced that the women's ranking would be split between ODIs and T20Is, and released both tables shortly thereafter.


title: Twenty20

text: This is a list of the current Twenty20 domestic competitions in several of the leading cricket countries.


title: Relay

text: A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals. The switch may have any number of contacts in multiple contact forms, such as make contacts, break contacts, or combinations thereof.


title: Relay

text: Relays are used where it is necessary to control a circuit by an independent low-power signal, or where several circuits must be controlled by one signal. Relays were first used in long-distance telegraph circuits as signal repeaters: they refresh the signal coming in from one circuit by transmitting it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations.


title: Relay

text: The traditional form of a relay uses an electromagnet to close or open the contacts, but relays using other operating principles have also been invented, such as in solid-state relays which use semiconductor properties for control without relying on moving parts. Relays with calibrated operating characteristics and sometimes multiple operating coils are used to protect electrical circuits from overload or faults; in modern electric power systems these functions are performed by digital instruments still called "protective relays".


title: Relay

text: Latching relays require only a single pulse of control power to operate the switch persistently. Another pulse applied to a second set of control terminals, or a pulse with opposite polarity, resets the switch, while repeated pulses of the same kind have no effects. Magnetic latching relays are useful in applications when interrupted power should not affect the circuits that the relay is controlling.


title: Relay

text: In 1809 Samuel Thomas von Sömmerring designed an electrolytic relay as part of his electro-chemical telegraph.


title: Relay

text: Solely electrical relays got their start as a further improvement to telegraphs, with American scientist Joseph Henry who is often cited to have invented a relay in 1835 in order to improve his version of the electrical telegraph, developed earlier in 1831.


title: Relay

text: However, an official patent wasn't issued until 1840 to Samuel Morse for his telegraph, which is now called a relay. The mechanism described acted as a digital amplifier, repeating the telegraph signal, and thus allowing signals to be propagated as far as desired.


title: Relay

text: A simple electromagnetic relay consists of a coil of wire wrapped around a soft iron core (a solenoid), an iron yoke which provides a low reluctance path for magnetic flux, a movable iron armature, and one or more sets of contacts (there are two contacts in the relay pictured). The armature is hinged to the yoke and mechanically linked to one or more sets of moving contacts. The armature is held in place by a spring so that when the relay is de-energized there is an air gap in the magnetic circuit. In this condition, one of the two sets of contacts in the relay pictured is closed, and the other set is open. Other relays may have more or fewer sets of contacts depending on their function. The relay in the picture also has a wire connecting the armature to the yoke. This ensures continuity of the circuit between the moving contacts on the armature, and the circuit track on the printed circuit board (PCB) via the yoke, which is soldered to the PCB.


title: Relay

text: When an electric current is passed through the coil it generates a magnetic field that activates the armature, and the consequent movement of the movable contact(s) either makes or breaks (depending upon construction) a connection with a fixed contact. If the set of contacts was closed when the relay was de-energized, then the movement opens the contacts and breaks the connection, and vice versa if the contacts were open. When the current to the coil is switched off, the armature is returned by a force, approximately half as strong as the magnetic force, to its relaxed position. Usually this force is provided by a spring, but gravity is also used commonly in industrial motor starters. Most relays are manufactured to operate quickly. In a low-voltage application this reduces noise; in a high voltage or current application it reduces arcing.


title: Relay

text: When the coil is energized with direct current, a flyback diode or snubber resistor is often placed across the coil to dissipate the energy from the collapsing magnetic field (back EMF) at deactivation, which would otherwise generate a voltage spike dangerous to semiconductor circuit components. Such diodes were not widely used before the application of transistors as relay drivers, but soon became ubiquitous as early germanium transistors were easily destroyed by this surge. Some automotive relays include a diode inside the relay case. Resistors, while more durable than diodes, are less efficient at eliminating voltage spikes generated by relays and therefore not as commonly used.


title: Relay

text: If the relay is driving a large, or especially a reactive load, there may be a similar problem of surge currents around the relay output contacts. In this case a snubber circuit (a capacitor and resistor in series) across the contacts may absorb the surge. Suitably rated capacitors and the associated resistor are sold as a single packaged component for this commonplace use.


title: Relay

text: If the coil is designed to be energized with alternating current (AC), some method is used to split the flux into two out-of-phase components which add together, increasing the minimum pull on the armature during the AC cycle. Typically this is done with a small copper "shading ring" crimped around a portion of the core that creates the delayed, out-of-phase component, which holds the contacts during the zero crossings of the control voltage.


title: Relay

text: Contact materials for relays vary by application. Materials with low contact resistance may be oxidized by the air, or may tend to "stick" instead of cleanly parting when opening. Contact material may be optimized for low electrical resistance, high strength to withstand repeated operations, or high capacity to withstand the heat of an arc. Where very low resistance is required, or low thermally-induced voltages are desired, gold-plated contacts may be used, along with palladium and other non-oxidizing, semi-precious metals. Silver or silver-plated contacts are used for signal switching. Mercury-wetted relays make and break circuits using a thin, self-renewing film of liquid mercury. For higher-power relays switching many amperes, such as motor circuit contactors, contacts are made with a mixtures of silver and cadmium oxide, providing low contact resistance and high resistance to the heat of arcing. Contacts used in circuits carrying scores or hundreds of amperes may include additional structures for heat dissipation and management of the arc produced when interrupting the circuit. Some relays have field-replaceable contacts, such as certain machine tool relays; these may be replaced when worn out, or changed between normally open and normally closed state, to allow for changes in the controlled circuit.


title: Relay

text: Since relays are switches, the terminology applied to switches is also applied to relays; a relay switches one or more "poles", each of whose contacts can be "thrown" by energizing the coil. Normally open (NO) contacts connect the circuit when the relay is activated; the circuit is disconnected when the relay is inactive. Normally closed (NC) contacts disconnect the circuit when the relay is activated; the circuit is connected when the relay is inactive. All of the contact forms involve combinations of NO and NC connections.


title: Relay

text: The National Association of Relay Manufacturers and its successor, the Relay and Switch Industry Association define 23 distinct electrical contact forms found in relays and switches. Of these, the following are commonly encountered:


title: Relay

text: The "S" ("single") or "D" ("double") designator for the pole count may be replaced with a number, indicating multiple contacts connected to a single actuator. For example, 4PDT indicates a four-pole double-throw relay that has 12 switching terminals.


title: Relay

text: "EN 50005" are among applicable standards for relay terminal numbering; a typical EN 50005-compliant SPDT relay's terminals would be numbered 11, 12, 14, A1 and A2 for the C, NC, NO, and coil connections, respectively.


title: Relay

text: Where radio transmitters and receivers share one antenna, often a coaxial relay is used as a TR (transmit-receive) relay, which switches the antenna from the receiver to the transmitter. This protects the receiver from the high power of the transmitter. Such relays are often used in transceivers which combine transmitter and receiver in one unit. The relay contacts are designed not to reflect any radio frequency power back toward the source, and to provide very high isolation between receiver and transmitter terminals. The characteristic impedance of the relay is matched to the transmission line impedance of the system, for example, 50 ohms.


title: Relay

text: A contactor is a heavy-duty relay with higher current ratings, used for switching electric motors and lighting loads. Continuous current ratings for common contactors range from 10 amps to several hundred amps. High-current contacts are made with alloys containing silver. The unavoidable arcing causes the contacts to oxidize; however, silver oxide is still a good conductor. Contactors with overload protection devices are often used to start motors.


title: Relay

text: A force-guided contacts relay has relay contacts that are mechanically linked together, so that when the relay coil is energized or de-energized, all of the linked contacts move together. If one set of contacts in the relay becomes immobilized, no other contact of the same relay will be able to move. The function of force-guided contacts is to enable the safety circuit to check the status of the relay. Force-guided contacts are also known as "positive-guided contacts", "captive contacts", "locked contacts", "mechanically linked contacts", or "safety relays".


title: Relay

text: These safety relays have to follow design rules and manufacturing rules that are defined in one main machinery standard EN 50205 : Relays with forcibly guided (mechanically linked) contacts. These rules for the safety design are the one defined in type B standards such as EN 13849-2 as Basic safety principles and Well-tried safety principles for machinery that applies to all machines.


title: Relay

text: Force-guided contacts by themselves can not guarantee that all contacts are in the same state, however, they do guarantee, subject to no gross mechanical fault, that no contacts are in opposite states. Otherwise, a relay with several normally open (NO) contacts may stick when energized, with some contacts closed and others still slightly open, due to mechanical tolerances. Similarly, a relay with several normally closed (NC) contacts may stick to the unenergized position, so that when energized, the circuit through one set of contacts is broken, with a marginal gap, while the other remains closed. By introducing both NO and NC contacts, or more commonly, changeover contacts, on the same relay, it then becomes possible to guarantee that if any NC contact is closed, all NO contacts are open, and conversely, if any NO contact is closed, all NC contacts are open. It is not possible to reliably ensure that any particular contact is closed, except by potentially intrusive and safety-degrading sensing of its circuit conditions, however in safety systems it is usually the NO state that is most important, and as explained above, this is reliably verifiable by detecting the closure of a contact of opposite sense.


title: Relay

text: Force-guided contact relays are made with different main contact sets, either NO, NC or changeover, and one or more auxiliary contact sets, often of reduced current or voltage rating, used for the monitoring system. Contacts may be all NO, all NC, changeover, or a mixture of these, for the monitoring contacts, so that the safety system designer can select the correct configuration for the particular application. Safety relays are used as part of an engineered safety system.


title: Relay

text: A latching relay, also called "impulse", "bistable", "keep", or "stay" relay, or simply "latch", maintains either contact position indefinitely without power applied to the coil. The advantage is that one coil consumes power only for an instant while the relay is being switched, and the relay contacts retain this setting across a power outage. A latching relay allows remote control of building lighting without the hum that may be produced from a continuously (AC) energized coil.


title: Relay

text: In one mechanism, two opposing coils with an over-center spring or permanent magnet hold the contacts in position after the coil is de-energized. A pulse to one coil turns the relay on, and a pulse to the opposite coil turns the relay off. This type is widely used where control is from simple switches or single-ended outputs of a control system, and such relays are found in avionics and numerous industrial applications.


title: Relay

text: Another latching type has a remanent core that retains the contacts in the operated position by the remanent magnetism in the core. This type requires a current pulse of opposite polarity to release the contacts. A variation uses a permanent magnet that produces part of the force required to close the contact; the coil supplies sufficient force to move the contact open or closed by aiding or opposing the field of the permanent magnet. A polarity controlled relay needs changeover switches or an H-bridge drive circuit to control it. The relay may be less expensive than other types, but this is partly offset by the increased costs in the external circuit.


title: Relay

text: In another type, a ratchet relay has a ratchet mechanism that holds the contacts closed after the coil is momentarily energized. A second impulse, in the same or a separate coil, releases the contacts. This type may be found in certain cars, for headlamp dipping and other functions where alternating operation on each switch actuation is needed.


title: Relay

text: A stepping relay is a specialized kind of multi-way latching relay designed for early automatic telephone exchanges.


title: Relay

text: Very early computers often stored bits in a magnetically latching relay, such as ferreed or the later remreed in the 1ESS switch.


title: Relay

text: Some early computers used ordinary relays as a kind of latch—they store bits in ordinary wire-spring relays or reed relays by feeding an output wire back as an input, resulting in a feedback loop or sequential circuit. Such an electrically latching relay requires continuous power to maintain state, unlike magnetically latching relays or mechanically ratcheting relays.


title: Relay

text: In computer memories, latching relays and other relays were replaced by delay-line memory, which in turn was replaced by a series of ever faster and ever smaller memory technologies.


title: Relay

text: A machine tool relay is a type standardized for industrial control of machine tools, transfer machines, and other sequential control. They are characterized by a large number of contacts (sometimes extendable in the field) which are easily converted from normally open to normally closed status, easily replaceable coils, and a form factor that allows compactly installing many relays in a control panel. Although such relays once were the backbone of automation in such industries as automobile assembly, the programmable logic controller (PLC) mostly displaced the machine tool relay from sequential control applications.


title: Relay

text: A relay allows circuits to be switched by electrical equipment: for example, a timer circuit with a relay could switch power at a preset time. For many years relays were the standard method of controlling industrial electronic systems. A number of relays could be used together to carry out complex functions (relay logic). The principle of relay logic is based on relays which energize and de-energize associated contacts. Relay logic is the predecessor of ladder logic, which is commonly used in programmable logic controllers.


title: Relay

text: A mercury relay is a relay that uses mercury as the switching element. They are used where contact erosion would be a problem for conventional relay contacts. Owing to environmental considerations about significant amount of mercury used and modern alternatives, they are now comparatively uncommon.


title: Relay

text: A mercury-wetted reed relay is a form of reed relay that employs a mercury switch, in which the contacts are wetted with mercury. Mercury reduces the contact resistance and mitigates the associated voltage drop. Surface contamination may result in poor conductivity for low-current signals. For high-speed applications, the mercury eliminates contact bounce, and provides virtually instantaneous circuit closure. Mercury wetted relays are position-sensitive and must be mounted according to the manufacturer's specifications. Because of the toxicity and expense of liquid mercury, these relays have increasingly fallen into disuse.


title: Relay

text: The high speed of switching action of the mercury-wetted relay is a notable advantage. The mercury globules on each contact coalesce, and the current rise time through the contacts is generally considered to be a few picoseconds. However, in a practical circuit it may be limited by the inductance of the contacts and wiring. It was quite common, before restrictions on the use of mercury, to use a mercury-wetted relay in the laboratory as a convenient means of generating fast rise time pulses, however although the rise time may be picoseconds, the exact timing of the event is, like all other types of relay, subject to considerable jitter, possibly milliseconds, due to mechanical imperfections.


title: Relay

text: The same coalescence process causes another effect, which is a nuisance in some applications. The contact resistance is not stable immediately after contact closure, and drifts, mostly downwards, for several seconds after closure, the change perhaps being 0.5 ohm.


title: Relay

text: Multi-voltage relays are devices designed to work for wide voltage ranges such as 24 to 240 VAC and VDC and wide frequency ranges such as 0 to 300 Hz. They are indicated for use in installations that do not have stable supply voltages.


title: Relay

text: Electric motors need overcurrent protection to prevent damage from over-loading the motor, or to protect against short circuits in connecting cables or internal faults in the motor windings. The overload sensing devices are a form of heat operated relay where a coil heats a bimetallic strip, or where a solder pot melts, to operate auxiliary contacts. These auxiliary contacts are in series with the motor's contactor coil, so they turn off the motor when it overheats.


title: Relay

text: This thermal protection operates relatively slowly allowing the motor to draw higher starting currents before the protection relay will trip. Where the overload relay is exposed to the same ambient temperature as the motor, a useful though crude compensation for motor ambient temperature is provided.


title: Relay

text: The other common overload protection system uses an electromagnet coil in series with the motor circuit that directly operates contacts. This is similar to a control relay but requires a rather high fault current to operate the contacts. To prevent short over current spikes from causing nuisance triggering the armature movement is damped with a dashpot. The thermal and magnetic overload detections are typically used together in a motor protection relay.


title: Relay

text: Electronic overload protection relays measure motor current and can estimate motor winding temperature using a "thermal model" of the motor armature system that can be set to provide more accurate motor protection. Some motor protection relays include temperature detector inputs for direct measurement from a thermocouple or resistance thermometer sensor embedded in the winding.


title: Relay

text: A polarized relay places the armature between the poles of a permanent magnet to increase sensitivity. Polarized relays were used in middle 20th Century telephone exchanges to detect faint pulses and correct telegraphic distortion.


title: Relay

text: A reed relay is a reed switch enclosed in a solenoid. The switch has a set of contacts inside an evacuated or inert gas-filled glass tube that protects the contacts against atmospheric corrosion; the contacts are made of magnetic material that makes them move under the influence of the field of the enclosing solenoid or an external magnet.


title: Relay

text: Reed relays can switch faster than larger relays and require very little power from the control circuit. However, they have relatively low switching current and voltage ratings. Though rare, the reeds can become magnetized over time, which makes them stick "on", even when no current is present; changing the orientation of the reeds or degaussing the switch with respect to the solenoid's magnetic field can resolve this problem.


title: Relay

text: Sealed contacts with mercury-wetted contacts have longer operating lives and less contact chatter than any other kind of relay.


title: Relay

text: Safety relays are devices which generally implement protection functions. In the event of a hazard, the task of such a safety function is to use appropriate measures to reduce the existing risk to an acceptable level.


title: Relay

text: A solid-state contactor is a heavy-duty solid state relay, including the necessary heat sink, used where frequent on-off cycles are required, such as with electric heaters, small electric motors, and lighting loads. There are no moving parts to wear out and there is no contact bounce due to vibration. They are activated by AC control signals or DC control signals from programmable logic controllers (PLCs), PCs, transistor-transistor logic (TTL) sources, or other microprocessor and microcontroller controls.


title: Relay

text: A solid-state relay (SSR) is a solid state electronic component that provides a function similar to an electromechanical relay but does not have any moving components, increasing long-term reliability. A solid-state relay uses a thyristor, TRIAC or other solid-state switching device, activated by the control signal, to switch the controlled load, instead of a solenoid. An optocoupler (a light-emitting diode (LED) coupled with a photo transistor) can be used to isolate control and controlled circuits.


title: Relay

text: A static relay consists of electronic circuitry to emulate all those characteristics which are achieved by moving parts in an electro-magnetic relay.


title: Relay

text: Timing relays are arranged for an intentional delay in operating their contacts. A very short (a fraction of a second) delay would use a copper disk between the armature and moving blade assembly. Current flowing in the disk maintains a magnetic field for a short time, lengthening release time. For a slightly longer (up to a minute) delay, a dashpot is used. A dashpot is a piston filled with fluid that is allowed to escape slowly; both air-filled and oil-filled dashpots are used. The time period can be varied by increasing or decreasing the flow rate. For longer time periods, a mechanical clockwork timer is installed. Relays may be arranged for a fixed timing period, or may be field-adjustable, or remotely set from a control panel. Modern microprocessor-based timing relays provide precision timing over a great range.


title: Relay

text: Some relays are constructed with a kind of "shock absorber" mechanism attached to the armature, which prevents immediate, full motion when the coil is either energized or de-energized. This addition gives the relay the property of time-delay actuation. Time-delay relays can be constructed to delay armature motion on coil energization, de-energization, or both.


title: Relay

text: Time-delay relay contacts must be specified not only as either normally open or normally closed, but whether the delay operates in the direction of closing or in the direction of opening. The following is a description of the four basic types of time-delay relay contacts.


title: Relay

text: First, we have the normally open, timed-closed (NOTC) contact. This type of contact is normally open when the coil is unpowered (de-energized). The contact is closed by the application of power to the relay coil, but only after the coil has been continuously powered for the specified amount of time. In other words, the direction of the contact's motion (either to close or to open) is identical to a regular NO contact, but there is a delay in closing direction. Because the delay occurs in the direction of coil energization, this type of contact is alternatively known as a normally open, on-delay.


title: Relay

text: A vacuum relay is a sensitive relay having its contacts mounted in an evacuated glass housing, to permit handling radio-frequency voltages as high as 20,000 volts without flashover between contacts even though contact spacing is as low as a few hundredths of an inch when open.


title: Relay

text: Relays are used wherever it is necessary to control a high power or high voltage circuit with a low power circuit, especially when galvanic isolation is desirable. The first application of relays was in long telegraph lines, where the weak signal received at an intermediate station could control a contact, regenerating the signal for further transmission. High-voltage or high-current devices can be controlled with small, low voltage wiring and pilots switches. Operators can be isolated from the high voltage circuit. Low power devices such as microprocessors can drive relays to control electrical loads beyond their direct drive capability. In an automobile, a starter relay allows the high current of the cranking motor to be controlled with small wiring and contacts in the ignition key.


title: Relay

text: Electromechanical switching systems including Strowger and Crossbar telephone exchanges made extensive use of relays in ancillary control circuits. The Relay Automatic Telephone Company also manufactured telephone exchanges based solely on relay switching techniques designed by . The first public relay based telephone exchange in the UK was installed in Fleetwood on 15 July 1922 and remained in service until 1959.


title: Relay

text: The use of relays for the logical control of complex switching systems like telephone exchanges was studied by Claude Shannon, who formalized the application of Boolean algebra to relay circuit design in A Symbolic Analysis of Relay and Switching Circuits. Relays can perform the basic operations of Boolean combinatorial logic. For example, the boolean AND function is realised by connecting normally open relay contacts in series, the OR function by connecting normally open contacts in parallel. Inversion of a logical input can be done with a normally closed contact. Relays were used for control of automated systems for machine tools and production lines. The Ladder programming language is often used for designing relay logic networks.


title: Relay

text: Early electro-mechanical computers such as the ARRA, Harvard Mark II, Zuse Z2, and Zuse Z3 used relays for logic and working registers. However, electronic devices proved faster and easier to use.


title: Relay

text: Because relays are much more resistant than semiconductors to nuclear radiation, they are widely used in safety-critical logic, such as the control panels of radioactive waste-handling machinery. Electromechanical protective relays are used to detect overload and other faults on electrical lines by opening and closing circuit breakers.


title: Relay

text: For protection of electrical apparatus and transmission lines, electromechanical relays with accurate operating characteristics were used to detect overload, short-circuits, and other faults. While many such relays remain in use, digital protective relays now provide equivalent and more complex protective functions.


title: Relay

text: Railway signalling relays are large considering the mostly small voltages (less than 120 V) and currents (perhaps 100 mA) that they switch. Contacts are widely spaced to prevent flashovers and short circuits over a lifetime that may exceed fifty years.


title: Relay

text: Since rail signal circuits must be highly reliable, special techniques are used to detect and prevent failures in the relay system. To protect against false feeds, double switching relay contacts are often used on both the positive and negative side of a circuit, so that two false feeds are needed to cause a false signal. Not all relay circuits can be proved so there is reliance on construction features such as carbon to silver contacts to resist lightning induced contact welding and to provide AC immunity.


title: Relay

text: Opto-isolators are also used in some instances with railway signalling, especially where only a single contact is to be switched.


title: Relay

text: Selection of an appropriate relay for a particular application requires evaluation of many different factors:


title: Relay

text: There are many considerations involved in the correct selection of a control relay for a particular application, including factors such as speed of operation, sensitivity, and hysteresis. Although typical control relays operate in the 5 ms to 20 ms range, relays with switching speeds as fast as 100 μs are available. Reed relays which are actuated by low currents and switch fast are suitable for controlling small currents.


title: Relay

text: As with any switch, the contact current (unrelated to the coil current) must not exceed a given value to avoid damage. In high-inductance circuits such as motors, other issues must be addressed. When an inductance is connected to a power source, an input surge current or electromotor starting current larger than the steady-state current exists. When the circuit is broken, the current cannot change instantaneously, which creates a potentially damaging arc across the separating contacts.


title: Relay

text: Consequently, for relays used to control inductive loads, we must specify the maximum current that may flow through the relay contacts when it actuates, the "make rating"; the continuous rating; and the "break rating". The make rating may be several times larger than the continuous rating, which is larger than the break rating.


title: Relay

text: Switching while "wet" (under load) causes undesired arcing between the contacts, eventually leading to contacts that weld shut or contacts that fail due to a buildup of surface damage caused by the destructive arc energy.


title: Relay

text: Inside the Number One Electronic Switching System (1ESS) crossbar switch and certain other high-reliability designs, the reed switches are always switched "dry" (without load) to avoid that problem, leading to much longer contact life.


title: Relay

text: Without adequate contact protection, the occurrence of electric current arcing causes significant degradation of the contacts, which suffer significant and visible damage. Every time the relay contacts open or close under load, an electrical arc can occur between the contacts of the relay, either a "break" arc (when opening), or a "make" / "bounce" arc (when closing). In many situations, the "break" arc is more energetic and thus more destructive, in particular with inductive loads, but this can be mitigated by bridging the contacts with a snubber circuit. The inrush current of tungsten filament incandescent lamps is typically ten times the normal operating current. Thus, relays intended for tungsten loads may use special contact composition, or the relay may have lower contact ratings for tungsten loads than for purely resistive loads.


title: Relay

text: An electrical arc across relay contacts can be very hot — thousands of degrees Fahrenheit — causing the metal on the contact surfaces to melt, pool, and migrate with the current. The extremely high temperature of the arc splits the surrounding gas molecules, creating ozone, carbon monoxide, and other compounds. Over time, the arc energy slowly destroys the contact metal, causing some material to escape into the air as fine particulate matter. This action causes the material in the contacts to degrade and coordination, resulting in device failure. This contact degradation drastically limits the overall life of a relay to a range of about 10,000 to 100,000 operations, a level far below the mechanical life of the device, which can be in excess of 20 million operations.


title: John A. Gotti

text: John Angelo Gotti (born February 14, 1964) is an American former mobster who was the acting boss of the Gambino crime family from 1991 to 1999. Gotti became acting boss when the boss of the family, his father John Gotti, was sent to prison. The younger Gotti was himself imprisoned for racketeering in 1999, and between 2004 and 2009 he was a defendant in four racketeering trials, each of which ended in a mistrial. In January 2010, federal prosecutors announced that they would no longer seek to prosecute Gotti for those charges.


title: John A. Gotti

text: Gotti was born in the Queens borough of New York City on February 14, 1964, to Italian-American mobster, John Gotti and Victoria DiGiorgio Gotti, whose father was of Italian descent, and mother was of half-Italian half-Russian ancestry. Gotti was raised in a two-story house in Howard Beach, New York, with his four siblings, which include sisters Victoria Gotti, and Angel, and brothers Frank and Peter. Angelo Ruggiero was his godfather and middle namesake, whom he and his siblings considered an uncle. Gotti attended New York Military Academy in his youth.


title: John A. Gotti

text: After graduating school, Gotti's father helped him start a trucking business, Samson Trucking Company, and after the business failed, helped him get a position in the Carpenters Union.


title: John A. Gotti

text: According to federal prosecutors, Gotti was inducted into the Gambino crime family on Christmas Eve 1988. According to fellow mobster Michael DiLeonardo who was initiated the same night, Gravano held the ceremony to keep Gotti from being accused of nepotism. He was named a "caporegime" (captain) in 1990, and is believed to be the youngest capo in the Gambino family's history.


title: John A. Gotti

text: In April 1992, his father, John J. Gotti, received a life sentence for racketeering and related offenses. His father asserted his prerogative to retain his title as boss until his death or retirement, with his brother Peter and his son Gotti Jr. relaying orders on his behalf.


title: John A. Gotti

text: Remembering how his father had been brought down by FBI bugs, Gotti adopted a more secretive way of doing business. He discussed mob business mainly through "walk-talks," or conversations held while walking alongside trusted captains. He also tried to pose as a legitimate businessman. However, several of his button men didn't think much of him, thinking he was incompetent. He was not nearly as good a negotiator as his father had been, and the Gambinos lost out on several disputes with the other families. The Genovese family was so unimpressed with Gotti that it refused to deal with him at all. In 1995, Charles Carneglia and John Alite were involved in a major conspiracy to murder Gotti.


title: John A. Gotti

text: In a 1997 search of the basement of a property owned by Gotti, the FBI found a typed list of the names of the "made" members of his organization, as well as $348,700 in cash, a list of the guests who attended his wedding, along with the dollar amount of their wedding gifts (totaling more than $350,000), and two handguns. Also found was a list of several men who were inducted into other families in 1991 and 1992; a longstanding rule in the New York Mafia calls for prospective members to be vetted by the other families before being inducted. However, normally these lists are destroyed almost as soon as the inductions take place. The discovery enraged Gotti's father as well as the other bosses, since it put dozens of other mafiosi at risk of government scrutiny. The episode earned him the nickname "Dumbfella" in the New York media.


title: John A. Gotti

text: By 1998, when he was indicted on racketeering charges under the Racketeer Influenced and Corrupt Organizations (RICO) Act, Gotti Jr. was believed to be the acting boss of the family. Many of the charges related to attempts to extort money from the owners and employees of Scores, an upscale strip club in Manhattan. According to the indictment, the Gambinos had forced the owners of Scores to pay $1 million over a six-year period in order to stay in business, with Gotti's share of the money totaling $100,000. In addition to the lists seized in the 1997 raid, prosecutors obtained transcripts of prison conversations in which Gotti Jr. received advice from his father on how to run the family. On April 5, 1999, faced with overwhelming evidence, Gotti Jr. pleaded guilty to four acts of racketeering, including bribery, extortion, and the threat of violence, against his father's advice. His lawyer said he decided to accept a plea bargain because he believed that he would be subjected to repeated prosecutions in multiple jurisdictions if he did not. On September 4, 1999, Gotti Jr. was sentenced to six years and five months in prison and fined $1 million. Federal prosecutors said his uncle, Peter Gotti, became head of the Gambino organization after Gotti Jr. was sent to prison, and he is believed to have formally succeeded his brother shortly before Gotti Sr.'s death in June 2002. Gotti Jr.'s indictment had brought stress on his parents' marriage; his mother, up to that point, unaware of her son's involvement in the Mafia, blamed her husband for ruining her son's life and threatened to leave him unless he allowed Gotti Jr. to leave the mob.


title: John A. Gotti

text: In 2004, months before he was released from prison, Gotti was charged in an 11-count racketeering indictment which included an alleged plot to kidnap Curtis Sliwa, founder of the Guardian Angels, as well as securities fraud, extortion and loansharking. A radio talk show host for WABC, Sliwa had allegedly angered the family by denouncing the elder Gotti as "Public Enemy #1" on his show. During the trial two former associates, Michael DiLeonardo and Joseph D'Angelo, testified against Gotti. Through his attorney Jeffrey Lichtman, Gotti admitted that he had been involved in the Gambino crime family in the 1990s, and had even been slated to lead the organization after his father was sent to jail in 1992, but claimed he had left criminal life behind after his conviction in 1999. Three juries eventually deadlocked on the charges, the last in 2006, and federal prosecutors decided not to pursue a fourth trial.


title: John A. Gotti

text: In August 2008, Gotti was arrested and indicted on racketeering and murder conspiracy charges brought in Florida. The charges stemmed from an alleged drug trafficking ring Gotti operated along with former associate-turned-government witness John Alite, and with the murders of George Grosso in 1988, Louis DiBono in 1990 and Bruce John Gotterup in 1991. Prosecutors charge that the ring distributed at least five kilograms of cocaine in the late 1980s and early 1990s. Gotti's trial was later moved to New York, where he pleaded not guilty, and began in September 2009.


title: John A. Gotti

text: In January 2008, Alite pleaded guilty to two murders, four murder conspiracies, at least eight shootings, and two attempted shootings as well as armed home invasions and armed robberies in New York, New Jersey, Pennsylvania and Florida, stemming from his alleged involvement in a Gambino crew in Tampa, Florida. Alite agreed to testify in the trial of Gambino family enforcer Charles Carneglia, who was found guilty of four murders and is now serving a life sentence. He then served as a key prosecution witness against Gotti.


title: John A. Gotti

text: During the trial, Gotti allegedly threatened Alite by mouthing the words "I'll kill you", and engaged in a shouting match with his former associate. After the incident, Victoria Gotti told the "New York Daily News" that Alite was "a pathological liar—a rat caught in a proverbial trap, caught in his own lies..." Alite testified that Gotti was responsible for at least eight murders, among other crimes.


title: John A. Gotti

text: On December 1, 2009, the 12 jurors announced that they had failed to reach a unanimous verdict on all the charges and the judge declared a mistrial. After the trial, jurors said that they did not find witnesses, particularly Alite, to be credible. One of the jurors said, "they should stop this now—it's ridiculous," while another said, "It's abusive. It's almost become a mockery." Gotti, Federal Bureau of Prisons Register # 00632-748, was released on December 1, 2009. After Gotti's fourth mistrial, federal prosecutors had indicated that they would not seek another trial against Gotti. In January 2010, the government decided not to pursue further charges against Gotti.


title: John A. Gotti

text: Gotti Jr. maintains that he has since left the Gambino family, and in a 2015 interview with the "New York Daily News", Gotti denied claims that he was an informant, claiming that he did give the FBI information but that it was false information and that no indictments resulted from the information he gave agents.


title: John A. Gotti

text: In 1990, Gotti married Kimberly Albanese. They have six children and live in Oyster Bay Cove on Long Island's North Shore. His son, John Gotti III, is a professional MMA fighter.