Ticks
Castor bean tick, Ixodes ricinus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Arachnida
Subclass:	Acari
Superorder:	Parasitiformes
Order:	Ixodida Leach, 1815
Superfamily:	Ixodoidea Leach, 1815
Families
Ixodidae – hard ticks Argasidae – soft ticks Nuttalliellidae
Diversity
18 genera, c. 900 species

Ticks are small arachnids in the order Ixodida. Along with mites, they constitute the subclass Acarina. Ticks are ectoparasites (external parasites), living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians. Ticks are vectors of a number of diseases, including Lyme disease, Q fever (rare; more commonly transmitted by infected excreta),^[1] Colorado tick fever, Rocky Mountain Spotted Fever, African tick bite fever, tularemia, tick-borne relapsing fever, babesiosis, ehrlichiosis, Tick paralysis and tick-borne meningoencephalitis, as well as bovine anaplasmosis.

Taxonomy[link]

There are three families of ticks, one of which – Nuttalliellidae – comprises a single species, Nuttalliella namaqua. The remaining two families contain the hard ticks (Ixodidae) and the soft ticks (Argasidae).^[2][3]

Ixodidae are distinguished from the Argasidae by the presence of a scutum or hard shield. Ixodidae nymphs and adults both have a prominent capitulum (head) which projects forwards from the body; in the Argasidae, conversely, the capitulum is concealed beneath the body.^[4]

Argasidae contains 193 species, although the composition of the genera is less certain, and more study is needed before the genera can become stable.^[2] The currently accepted genera are Antricola, Argas, Nothaspis, Ornithodoros and Otobius.^[2] Though common in North America, they feed rapidly, primarily on birds, and are very rarely found to parasitize land animals or humans.^[5]

Nuttalliella namaqua is a tick found in southern Africa from Tanzania to Namibia and South Africa,^[6] which is placed in its own family, Nuttalliellidae.^[2] It can be distinguished from ixodid ticks and argasid ticks by a combination of characters including the position of the stigmata, lack of setae, strongly corrugated integument, and form of the fenestrated plates.^[7]

Fossilized ticks are common. Recent hypotheses based on total-evidence approach analysis place the origin of ticks in the Cretaceous (65 to 146 million years ago) with most of the evolution and dispersal occurring during the Tertiary (5 to 65 million years ago).^[8] The oldest example is an argasid (bird) tick from Cretaceous New Jersey amber. The younger Baltic and Dominican ambers have also yielded examples, all of which can be placed in living genera.

Range and habitat[link]

Tick species are widely distributed around the world.^[9] However, they tend to flourish more in countries with warm, humid climates, because they require a certain amount of moisture in the air in order to undergo metamorphosis, and because low temperatures inhibit their development from egg to larva.^[10] Ticks of domestic animals are especially common and varied in tropical countries, where they cause considerable harm to livestock by transmission of many species of pathogens and also causing direct parasitic damage.

For an ecosystem to support ticks, it must satisfy two requirements: there must be a high enough population density of host species in the area, and there must be high enough humidity for ticks to remain hydrated.^[11] Due to their role in transmitting Lyme disease, ixodid ticks, particularly I. scapularis, have been studied using geographic information systems (GIS), in order to develop predictive models for ideal tick habitats. According to these studies, it was determined that certain features of a given micro-climate – such as sandy soil, hardwood trees, rivers, and the presence of deer – are good predictors of dense tick populations.^[5]

Anatomy and physiology[link]

Ticks, like mites, have bodies which are divided into two primary sections: the anterior capitulum (or gnathosoma), which contains the head and mouthparts; and the posterior idiosoma which contains the legs, digestive tract, and reproductive organs.^[11]

Diet and feeding behaviors[link]

Ticks, such as these Ixodes scapularis', climb to the ends of leaves or branches and attach to hosts that brush against them.

Ticks satisfy all of their nutritional requirements on a diet of blood, a practice known as hematophagy. They extract the blood by cutting a hole in the host's epidermis, into which they insert their hypostome, likely keeping the blood from clotting by excreting an anticoagulant.^[12]

Legs[link]

Ticks have eight legs.

Like all arachnids, ticks have eight legs. The legs of Ixodidae and Argasidae are similar in structure. Each leg is composed of six segments: the coxa, trochanter, femur, patella, tibia, and tarsus. Each of these segments are connected by muscles which allow for flexion and extension, however the coxae have limited lateral movement. When not being used for walking, the legs remain tightly folded against the body.^[13][14]

In addition to being used for locomotion, the tarsus of leg I contains a unique sensory organ known as the Haller's organ which can detect odors and chemicals emanating from the host, as well as sensing changes in temperature and air currents.^[13][14][15]

Life cycle and reproduction[link]

Ixodidae[link]

Both ixodid and argasid ticks undergo three primary stages of development: larval, nymphal, and adult.^[16] Ixodid ticks require three hosts, and their life cycle takes at least one year to complete. Up to 3,000 eggs are laid on the ground by an adult female tick. When larvae emerge, they feed primarily on small mammals and birds. After feeding, they detach from their host and molt to nymphs on the ground, which then feed on larger hosts and molt to adults. Female adults attach to larger hosts, feed, and lay eggs, while males feed very little and occupy larger hosts primarily for mating.^[5]

Argasidae[link]

Argasid ticks, unlike ixodid ticks, may go through several nymphal stages, requiring a meal of blood each time.^[17] Their lifecycle ranges from months to years. The adult female argasid tick can lay anywhere from a few hundred to over a thousand eggs over the course of her lifetime. Larvae feed very quickly and detach to molt to nymphs. Nymphs may go through as many as seven instars, each requiring a blood meal. Both male and female adults blood-feed, and they mate off the host. During feeding, any excess fluid is excreted by the coxal glands, a process which is unique to argasid ticks.^[5]

Researcher collecting ticks using the "tick dragging" method.

Medical issues[link]

A sign in a Lithuanian forest warning about a high risk of Tick-borne encephalitis infection

Tick-borne disease[link]

Tick-borne illnesses are caused by infection with a variety of pathogens, including rickettsia and other types of bacteria, viruses, and protozoa. Because ticks can harbor more than one disease-causing agent, patients can be infected with more than one pathogen at the same time, compounding the difficulty in diagnosis and treatment. Major tick-borne diseases include Lyme disease, Rocky Mountain spotted fever, relapsing fever, tularemia, tick-borne meningoencephalitis, Colorado tick fever, Crimean-Congo hemorrhagic fever, babesiosis and cytauxzoonosis. A recent find is candidatus neoehrlichia mikurensis, a bacterium which causes blood clots: present in 9% of rodents, it mainly affects persons with lowered immune defense, and can be cured with antibiotics.^[18]

Tick bites may also induce a delayed allergy to red meat, involving the oligosaccharide, galactose alpha-1,3-galactose: the food-induced reactions, including anaphylaxis, characteristically present several hours after eating in subjects who have experienced a large local reaction to tick bites up to six months earlier.^[19][20]

Eggs can be infected with pathogens inside the ovaries, meaning that baby ticks can be infectious immediately at birth, before feeding on their first host.^[17]

First aid[link]

Engorged tick attached to back of toddler's head. Adult thumb shown for scale.

In general, the best way to remove adult Ixodidae is mechanically. To facilitate prompt removal, fine-tipped tweezers can be used to grasp the tick as close to the skin as possible and detach it by applying a steady upward force without crushing, jerking or twisting, in such a way as to avoid leaving behind mouthparts or provoking regurgitation of infective fluids into the wound.^[21][22][23] Proprietary tick removal tools are also available.^[21][22] It is important to disinfect the bite area thoroughly after removal of the tick.^[23] The tick can be stored and, in case of signs or symptoms of a subsequent infection, shown to a clinician for identification purposes together with details of where and when the bite occurred.^[21] If the tick's head and mouthparts are not attached to the body after removal, it may be necessary to perform a punch biopsy to remove any parts remaining inside the patient.^[24]

Population control measures[link]

With the possible exception of widespread DDT use in the Soviet Union, attempts to limit the population or distribution of disease-causing ticks have been very unsuccessful.^[25]

The parasitic Ichneumon wasp Ixodiphagus hookeri has long been investigated for its potential to control tick populations. It lays its eggs into ticks; the hatching wasps kill their host.

Another natural form of control for ticks is the guineafowl, a bird species which consumes mass quantities of ticks.^[26] Just 2 birds can clear 2 acres (8,100 m²) in a single year.

Topical (drops/dust) flea/tick medicines may be toxic to animals and humans. Phenothrin (85.7%) in combination with Methoprene was a popular topical flea/tick therapy for felines. Phenothrin kills adult fleas and ticks. Methoprene is an insect growth regulator that interrupts the insect's life cycle by killing the eggs. However, the U.S. Environmental Protection Agency required at least one manufacturer of these products to withdraw some products and include strong cautionary statements on others, warning of adverse reactions.^[27]

Deer ticks[link]

The black legged or deer tick (Ixodes scapularis) is dependent on the white-tailed deer for reproduction. Larval and nymph stages (immature ticks that cannot reproduce) of the deer tick feed on birds and small mammals. The adult female tick needs a large 3-day blood meal from the deer before she can reproduce and lay her 2000 or more eggs. Deer are the primary host for the adult deer tick and are key to the reproductive success of the tick.^[28]

Numerous studies have shown that abundance and distribution of deer ticks are correlated with deer densities.^{[28][29][30][31]}

When the deer population was reduced by 74% at a 248-acre (100 ha) study site in Bridgeport, Connecticut, for example, the number of nymphal ticks collected at the site decreased by 92%.^[28] The relationship between deer abundance, tick abundance, and human cases of Lyme disease was well documented in the Mumford Cove Community in Groton, Connecticut, from 1996 to 2004. The deer population in Mumford Cove was reduced from about 77 deer per square mile to about 10 deer per square mile (4 deer per square kilometer) after 2 years of controlled hunting. After the initial reduction the deer population was maintained at low levels. Reducing deer densities to 10 deer per square mile (4 deer per square kilometer) was adequate to reduce by more than 90% the risk of humans contracting Lyme disease in Mumford Cove.^[32]

A 2006 study by Penn State's Center for Infectious Disease Dynamics indicated that reducing the deer population in small areas (but not large areas) may lead to higher tick densities, resulting in more tick-borne infections in rodents leading to a high prevalence of tick-borne encephalitis and creating a tick hot-spot.^[33]

See also[link]

Wikimedia Commons has media related to: Ixodida

Arthropods portal

• Flea
• Mosquito
• Parasitology
• Vampire bat
• Rickettsia helvetica
• Ticks of domestic animals

References[link]

Notes[link]

Bibliography[link]

Further reading[link]

• Bruin, Jan & L. P. S. van der Greest, ed. (2009). Diseases of Mites and Ticks. Springer. ISBN 978-1-4020-9694-5. http://books.google.com/books?id=2gz_JSTOzZ8C. 
• Cunha, Burke A. (2000). Tickborne Infectious Diseases: Diagnosis and Management. CRC Press. ISBN 978-0-8247-0310-3. http://books.google.com/books?id=UOKub5HbpoYC. 
• Service, M. W. (2004). "Soft ticks (Argasidae)". Medical Entomology for Students. Cambridge University Press. pp. 213–221. ISBN 978-0-521-54775-8. http://books.google.com/books?id=yi5gRCErrrQC&pg=PA213. 
• Service, M. W. (2004). "Hard ticks (Ixodidae)". Medical Entomology for Students. Cambridge University Press. pp. 222–236. ISBN 978-0-521-54775-8. http://books.google.com/books?id=yi5gRCErrrQC&pg=PA222. 
• Sonenshine, Daniel E. (1993). Biology of Ticks. Vols. 1 & 2. Oxford University Press. ISBN 978-0-19-508431-3. http://books.google.com/books?id=6LXwAAAAMAAJ. 

v t e Acari (ticks and mites) Acariformes Trombidiformes Sphaerolichida Prostigmata Sarcoptiformes Endeostigmata Oribatida Parasitiformes Opilioacariformes Opilioacaridae Holothyrida Allothyridae Holothyridae Neothyridae Ixodida (ticks) Argasidae Ixodidae Nuttalliellidae Mesostigmata Sejida Sejoidea Trigynaspida Cercomegistoidea Antennophoroidea Celaenopsoidea Fedrizzioidea Megisthanoidea Parantennuloidea Aenictequoidea Monogynaspida Microgynioidea Heatherelloidea Thinozerconoidea Polyaspidoidea Uropodoidea Trachyuropodoidea Diarthrophalloidea Epicrioidea Zerconoidea Arctacaroidea Parasitoidea Veigaioidea Rhodacaroidea Eviphidoidea Ascoidea Phytoseioidea Dermanyssoidea

The-Dream
The-Dream performing on September 10, 2008 in New York City.
Background information
Birth name	Terius Youngdell Nash
Born	(1977-09-20) September 20, 1977 (age 34) Rockingham, North Carolina, U.S.
Genres	R&B, pop, hip hop
Occupations	singer-songwriter, record producer
Years active	1998–Present
Labels	Def Jam, Radio Killa
Associated acts	Christopher "Tricky" Stewart, Los Da Mystro, Jennifer Lopez, Electrik Red, Rihanna, Kanye West, Beyonce, Jay-Z, Drake Fabolous, Jamie Foxx
Website	the-dreammusic.com

Terius Youngdell Nash (Born September 20, 1977), better known by his stage name The-Dream, is an American singer-songwriter and record producer. He is known for co-writing chart topping hits such as "Baby" for Justin Bieber, "Umbrella" for Rihanna and "Single Ladies (Put a Ring on It)" for Beyoncé, as well as for his three solo albums, Love Hate, Love vs. Money, and Love King.

Early life[link]

Terius Nash was born in Rockingham, North Carolina and moved with his mother, Reva Nash, to Atlanta at the age of 3. He played trumpet, drums, and guitar as a child.^[1] His mother died in 1992 when Nash was fifteen years old, an event which would inspire him to write songs.^[2] He states that the death of his mother gave him a "soft spot" for women, which he credits to his desire to write songs about female empowerment such as Rihanna's "Umbrella".^[2] He moved in with his grandfather, a concrete mason who instilled a strong work ethic in young Nash. Of his grandfather, Nash recalls "He came out of a bad time for blacks in the South, but even though we lived in the hood, we had a boat, some cars and a house that was paid for. So I’ve always had a different outlook on life. There’s nothing I can’t do."^[3]

Music career[link]

Background[link]

Nash met R&B producer Laney Stewart in 2001; Stewart helped him get a publishing deal after writing "Everything" for B2K's album Pandemonium!.^[1] Under the pen name "The-Dream", Nash began writing lyrics for many popular artists. He spent two years working on Nivea's second album Complicated, which he executive produced, and continued to write and produce with Christopher "Tricky" Stewart, Laney's brother, which led to Rihanna's 2007 smash hit "Umbrella". The success of "Umbrella" boosted Dream's music career, and in 2007, he signed a deal with Def Jam Records.^[4]

Solo[link]

Following the deal with Def Jam Records, The-Dream began working on his debut studio album Love Hate.^[4] The album was produced by The-Dream's production partner Tricky Stewart, and Carlos "LOS Da Maestro" McKinney, and featured Fabolous and Rihanna.^[5] The album was written and recorded in eight days with twelve tracks making the final cut. Some of the tracks were written in regards to The-Dream's personal life, most notably "Nikki," written about his ex-wife Nivea and how he has moved on since their divorce.^[6] The-Dream explained the title, Love Hate, as short for, "Love me all summer, hate me all winter, because they love you when you hot and when you're cold they don't... I'm hot right now and they love me, but I was cold and they wasn't fuckin' with me."^[6] Released December 11, 2007 on The-Dream's Def Jam-imprint Radio Killa Records,^[7] Love Hate moved 59,000 copies and debuted at number 30 on the Billboard 200.^[8] Love Hate also peaked at #5 on the Billboard Top R&B/Hip-Hop Albums chart.^[9] The album received generally positive reviews from critics, as Rolling Stone called it "one of the most likable R&B records of the year" and UrbanMusicReviews.com said that the singer has "hit a home run."^[10]

On March 10, 2009 The-Dream released his second album Love vs. Money.^[11] He re-teamed with his production partner Christopher "Tricky" Stewart, who produced most of the tracks on the album, and Los Da Maestro.^[12] He also enlisted the help of Lil Jon for the song "Let Me See the Booty".^[8] Love vs. Money debuted at number two on the Billboard 200, selling 151,000 copies in its first week.^[13] It also entered at number one on Billboard's Top R&B/Hip-Hop Albums and at number three on its Top Digital Albums chart in March 2009.^[14][15] Upon its release, the album received general acclaim from most music critics, based on an aggregate score of 83/100 from Metacritic.^[16]

During the making of Love King, he recorded a song with T-Pain and expressed that he would like to make a collaborative album with Kanye West in the future.^[17] In January 2010, The-Dream officially stated he was finished recording the album and he called it the best of his three albums.^[18] The first single, "Love King", was released on March 16, 2010 for digital download. The album was released on June 29, 2010.^[19]

Before the album's release, the-Dream announced that Love King will be his last solo album.^[8][20] When Love King was released, the lyrics to the song "Sex Intelligent Remix" announced plans to release a new solo album called Love Affair and even gave the specific release date of June 7, 2011. In February 2011, The-Dream announced that the album is not titled "Love Affair" anymore, he stated that it is now titled "The Love, IV" and that he scrapped the June 7, 2011 release date and has set a new release date of August 2011.^[21] One week after anouncing that August release date, he said the he is pushing the album up and is hoping to release it on June 7 as promised.^[22] In June 2011, the album's title was changed yet again, this time to "Love IV: Diary of a Madman", it was also announced that it will released on September 20, 2011.^[23] On June 7, 2011; he released double promotional singles titled "Body Work" and "Fuck My Brains Out" to the internet.^[24] The Dream was not able to release "The Love, IV (Diary of a Mad Man)" on September 20, 2011 as planned and it was announced that the album got pushed back indefinitely due to "contract talks" with Def Jam Records.^[25] The-Dream then released a free 10-track album to the internet entitled 1977 on August 31, 2011.^[26][27] The-Dream also plans to release a 13-track studio album entitled Nikki: The Chronicles, which will follow his infatuation with the woman he sang about on 2007’s Love Hate and 2010’s Love King.^[28] In October 2011, Dream announced that he is personally pushing back the release of The Love; IV (Diary of A Madman) and that it will now be released in 2012. Dream also announced his plans to release his first international album, titled 1984: Persona of Love, it is set for release sometime in 2012, the album is a "persona album" and is inspired by his recent trip overseas.^[29] In February 2012, it was announced that the "The Love; IV (Diary of A Madman)" will be released on April 17, 2012.^[30] In March 2012, it was announced that "The Love; IV (Diary of A Madman)" has been re-titled "Love IV MMXII" and that its release date been pushed back to Summer 2012.^[31] In May 2012, it was announced that the album will be released on August 14, 2012.^[32]

Production[link]

In addition to working with Nivea and Rihanna, The-Dream also began writing for numerous artists, most notably J. Holiday's "Bed", Usher's "Moving Mountains", Yung Joc's "Coffee Shop" and Jesse McCartney's "Leavin'". He also co-wrote Mariah Carey's "Touch My Body", Ciara's "High Price," and took part in co-writing a majority of Mary J. Blige's 2007 Growing Pains album, including the smash hit "Just Fine". Recently^[when?] he featured in Drake (entertainer)'s album Thank Me Later the song "Shut It Down".

In December 2007, The-Dream was nominated for Grammy Award for Song of the Year for "Umbrella", but lost to Amy Winehouse's "Rehab". However, in June 2008, The-Dream won the award for Best New Artist at the 2008 BET Awards. Throughout 2008, The-Dream appeared on a number of records including Plies' "Please Excuse My Hands" with Jamie Foxx, LL Cool J's "Baby", Gym Class Heroes' "Cookie Jar" and Kardinal Offishall's "Gimme Some". In addition, The-Dream signed female R&B girl-group Electrik Red to Radio Killa Records and they released their debut album, How to Be a Lady: Volume 1, under the label.^[33] The-Dream and production partner Christopher "Tricky" Stewart produced "Single Ladies (Put a Ring on It)" off Beyoncé's album I Am… Sasha Fierce, co-produced two tracks ("Just Like Me" & "Digital Girl") and was featured on Jamie Foxx's album Intuition, and worked with Mario and Lionel Richie.^[8] He will also be featured on a number of upcoming albums from; Phyzikal, Ciara, Sterling Simms, Young Chris, Dear Jayne, Brandy and Cassie.

In early 2009, The-Dream began working with Christina Milian on her fourth studio album Elope,^[34] which led to her signing a joint-deal with Radio Killa Records.^[35] The-Dream said that when he was building his label, he went looking for Milian because he believed she was a talented singer.^[36] The singer confirmed that her second single would be a duet with The-Dream called "Supersonic".^[37]

Throughout 2009, The-Dream has also been working on new material for Mariah Carey, Brandy, and Diddy. Diddy's song "Change" is described by The-Dream as, "probably one of the best male records I've ever written...the best record I've written besides 'Umbrella'. The-Dream also worked on Jennifer Lopez's single Louboutins from her 7th album Love? by Sony Music. The song did not chart at the Billboard Hot 100 but charted at number 1 on the Hot/Dance Club Chart. He keep working on more tracks for her album which was released in Spring 2011 by Def Jam.^{[dated info][8][dated info]} He also collaborated on, produced and wrote Snoop Dogg's "Gangsta Luv", which is on the 2009 album Malice n Wonderland.

The-Dream and Tricky Stewart have worked on Ciara's fourth studio album titled "Basic Instinct", which was released on December 14, 2010, and was executive produced by the trio. He co-wrote her lead single titled "Ride", which was released in April 2010, and went on to become a R&B smash hit and her twelfth top ten hit on the Billboard R&B/Hip-Hop Songs chart.^[38]

The-Dream received a fair amount of backlash for his cover of singer Aaliyah's song "One in a Million". Upon the release of the song, fans of Aaliyah bombarded radio shows and blog sites with distaste for The-Dream's rendition.^[39]

He also worked alongside Tricky Stewart on Jessica Simpson's Christmas album titled Happy Christmas, released on November 22, 2010, and also working on Simpson's upcoming pop album, to be released in 2011.^{[dated info]}

The-Dream produced a music single for Kim Kardashian, "Jam (Turn It Up)", released in March 2, 2011 and then worked on Beyoncé's album titled 4, released on June 28, 2011.

On March 16, 2012, Billboard posted an interview with The-Dream, where he talked about having been given the opportunity to go in to the studio in a few weeks to work with Shakira, and how excited he is for the track.^[40]

Personal life[link]

The-Dream married girlfriend Nivea in 2004, whom he had been dating for one year. Together they had three children, daughter Navy Talia (on May 10, 2005); and twin sons London and Christian (April 2006). They had been married for three years when Nivea filed for legal separation in December 2007. The-Dream said that although he was in love with Nivea, his lack of experience in a family growing up meant he was "not taught how much more than love does it take to run a relationship. Like, 'cause love isn't just where it's gonna end. It can't start and stop with love. There has to be a certain amount of knowledge and patience that's acquired in order to keep it going and keep it straight, and I found out the hard way".^[41]

The-Dream began dating Christina Milian in early 2009; she became pregnant. The Daily Mail reported that "the pregnancy was a surprise, but they were getting married regardless".^[42] They then became engaged in June 2009.^[43] In August, it was reported that they had applied for a marriage license in Los Angeles. On September 4, 2009, The-Dream married Christina Milian at the Little White Chapel in Las Vegas.^[44] The-Dream said in an interview that Nivea was still a good friend of his, and that she was also friends with Milian.^[45] Milian gave birth to their daughter Violet Madison Nash on February 26, 2010.^[46] Milian and The-Dream announced their separation on July 12, 2010 ^[47] after photos surfaced of The-Dream vacationing with his assistant.^[48]

In addition to music, The-Dream revealed he is currently working on a TV reality series for MTV where he will scout aspiring singers,^[8] and plans to release a clothing line called Millionaire Love Affair.^[33]

Discography[link]

Studio albums

• Love Hate (2007)
• Love vs. Money (2009)
• Love King (2010)
• Love IV MMXII (2012)

Free album

• 1977 (2011)

Awards and nominations[link]

References[link]

External links[link]

• Official website

Steven Yeun
Born	Yeun Sang-yeop (1983-12-21) December 21, 1983 (age 28) South Korea
Occupation	Actor
Years active	2005-present
Korean name
Hangul	연상엽
Revised Romanization	Yeon Sang-yeop
McCune–Reischauer	Yǒn Sang'yǒp

Steven Yeun (born December 21, 1983) is a Korean-born American actor. Yeun is currently starring in the role of Glenn in the AMC television series The Walking Dead since 2010. Other than The Walking Dead, Yeun had a cameo in the critically acclaimed American sit-com The Big Bang Theory as Sheldon's former room mate Sebastian in 2010, an independent film and a couple of shorts. He has also completed voice work for the Crysis video game series.

Biography[link]

The son of Je and June Yeun, Yeun was born in South Korea and raised in Troy, Michigan.^[1][2] His parents owned two beauty supply stores in Detroit.^[2]

Yeun received a bachelor's degree in psychology from Kalamazoo College in 2005.^[2] His interest in acting and improv came during his freshman year at Kalamazoo, when he watched the college's improv group, Monkapult.^[2] He auditioned for Monkapult, but was initially rejected before successfully joining the group during his sophomore year.^[2]

Yeun revealed to his parents that he planned to pursue an improv career in Chicago, instead of enrolling in law school or medical school.^[2] His parents, while unhappy with the decision, were supportive, according to Yeun, and gave him two years to pursue acting.^[2] He moved to Chicago in 2005, living in the city's Lincoln Square with his brother.^[1] Shortly after graduation, he joined Stir Friday Night, a sketch comedy group composed of Asian-American members.^[2]

Yeun joined The Second City in Chicago before moving to Los Angeles in October 2009.^[2]

Filmography[link]

References[link]

External links[link]

• Steven Yeun at the Internet Movie Database
• Steve Yeun's twitter