title: Armoured warfare

text: The U.S. combined arms team included air support, artillery, engineers, and a tank component supplemented by tank destroyers formed into independent tank destroyer battalions. The latter is most closely identified with the Chief of Army Ground Forces, Lesley J. McNair. Having studied the early German successes McNair came under the belief that U.S. forces would be faced with fast moving enemy forces who would seek to bypass, isolate and reduce U.S. forces in a replay of the Fall of France. To stem the flood of marauding panzers, fast moving powerfully armed tank destroyer battalions were created to be held back and used in the counter-attack.


title: Armoured warfare

text: It was also calculated that U.S. interests would be better served by large numbers of reliable ("battle-worthiness") medium tanks rather than a smaller number of unreliable heavy tanks. It was decided therefore to slow the production of the U.S. heavy tank designs such as the M26 Pershing and concentrate resources on mass-producing the M4 Sherman and tank destroyers such as the M18 Hellcat.


title: Armoured warfare

text: To be able get into position to counter-attack, the tank destroyers had to be fast. To achieve the desired mobility and agility from the engines available the armour protection was sacrificed, a measure of protection coming from being nimble and hopefully from being able to knock out the enemy before they could get a shot in. Although they usually had guns of either 75 mm or 76 mm calibre (the M36 used a 90mm calibre gun), the tank destroyer units were issued with the ancestor of the modern armour-piercing discarding sabot, rounds which made their guns much more powerful than a simple comparison of calibres would suggest.


title: Armoured warfare

text: The Japanese doctrine was mainly French in concept but with some purely Japanese elements. Due to Japan's naval priorities in warship construction and inter-service feuds (the marine branch of the IJN favoured all-around protective armour) IJA tanks were lightly armoured. As with most armour during the 1930s, the main guns were small in calibre: 37 mm for their Type 95 light tanks and 47 mm for the Type 97 medium tank, but this was sometimes compensated by a high muzzle velocity. The IJA's use of tanks in China exemplifies its doctrine: light tanks were used for scouting or acted as mobile infantry support, while medium tanks supported the infantry and assaulted deeper objectives, but did not fight en masse.


title: Armoured warfare

text: In 1939, the Japanese Army engaged Soviet armour at Nomonhan. During the three-month-long war, Japanese armour had shown their weakness against Soviet tanks; and the resulting Japanese defeat prompted a series of complaints by the Imperial Army to incorporate improvements in future Japanese armour. This is the primary reason IJA tanks were not as successful while being used with IJA tactics. The tank forces of the U.S. Army consisted of the M2A4 and M3 Stuart light tanks up until 1941, although these vehicles were five years "newer" than the 1935 built Type 95's, the IJA and U.S. light tanks were comparable to each other, and seemingly performed well for their respective forces during jungle combat operations; during their phase of World War II.


title: Armoured warfare

text: As with all armour, maintenance was a continuous challenge; especially in tropical environments. When IJA and SNLF (Imperial marines) tanks did clash with the enemy they were quickly destroyed by concealed anti-tank guns or overwhelming numbers of hostile tanks. Japan was a naval power, and concentrated its production on warships, thus placing a low priority on armoured vehicle development, its tanks becoming quickly obsolete during the later years of the war. A number of designs that were equal to heavier foreign types were on the drawing board at the beginning of the war, but would only be built in small numbers towards the end, being placed in reserve, to be deployed for the defence of Japan itself.


title: Armoured warfare

text: The Republic of China's National Revolutionary Army's 200th Division was the country's only mechanised division during the war. The 200th used pre-war tanks acquired from Italy, Germany, and the Soviet Union.


title: Armoured warfare

text: The conflict between Arab nations in the East Mediterranean region and Israel in particular would serve to become a testing ground for development in armoured warfare during the decades of the Cold War. Both sides in the Arab–Israeli series of conflicts made heavy use of tanks and other armoured vehicles due to the practicality of tanks in the desert environment these conflicts largely took place in.


title: Armoured warfare

text: During the 1956 Suez War and Six-Day War (1967), Israeli armoured units typically had the advantage, mainly due to good tactics and unit cohesion.


title: Armoured warfare

text: Conversely, the Yom Kippur War (1973) illustrated the problems that can arise if armoured and infantry units do not work closely together. Israeli tanks, operating independently in large numbers, were decimated by Egyptian anti-tank teams, well-distributed amongst regular infantry, and often equipped with new, first-generation portable anti-tank guided missiles. This is an extreme example but exemplifies what has been fairly thoroughly documented since the Second World War: tanks and infantry work best by taking advantage of each other's strengths and combining to minimise the weaknesses.


title: Armoured warfare

text: In many conflicts, it was usual to see infantry riding on the back of tanks, ready to jump off and provide support when necessary. Unfortunately, the design of many modern tanks makes this a dangerous practice. The turboshaft-powered M1 Abrams, for example, has such hot exhaust gas that nearby infantry have to be careful where they stand. Tanks can also be very vulnerable to well aimed artillery; well-coordinated air support and counter-battery artillery units can help overcome this.


title: Armoured warfare

text: While attempts to defeat the tank were made before and during the Second World War, through the use of conventional high velocity anti-tank artillery, this proved increasingly difficult in the post-war period due to increased armour protection and mobility of tanks.


title: Armoured warfare

text: In response, the Soviet Union, the country with the largest armoured fleet in the world, strove to incorporate some anti-tank capability into almost every infantry weapon. By the 1960s, Soviet defense scientists were designing portable anti-tank guided missiles. These new weapons were to be either carried by infantry, or fired from the newly developed BMP-1 infantry fighting vehicle. They were in use with Soviet forces before the end of the decade.


title: Armoured warfare

text: In 1973, the Israeli Army failed to anticipate the importance of these new weapon systems. Hundreds of AT-3 Sagger man-portable anti-tank guided missiles (ATGMs), supplied to Egypt by the Soviet Union and could be operated by infantry without having extensive training, inflicted heavy losses on the Israeli armoured formations. Since then, ATGMs have played an important role within the Israeli Army, having developed advanced domestic-made versions ("see" Spike/Gil missile), which have been widely exported throughout the world.


title: Armoured warfare

text: In the recent 2006 conflict with Hezbollah, while Israeli infantry were able to easily defeat opposing ATGM teams, tanks operating on their own suffered several hits from the latest advanced Russian tandem-warhead types (such as the Kornet). This highlighted that tanks operating solely, in the era of ATGMs, are extremely vulnerable.


title: Armoured warfare

text: Responding to the serious tank losses suffered against Hezbollah, Rafael Advanced Defense Systems in cooperation with Israel Aircraft Industries developed a missile defence system for tanks, called Trophy, to intercept and destroy anti tank missiles. The system was successfully deployed in combat on March 1, 2011, when it intercepted an anti tank missile during an engagement on the Gaza border.


title: Armoured warfare

text: During the Cold War, NATO assumed armoured warfare to be a dominant aspect of conventional ground warfare in Europe. Although the use of light tanks was largely discontinued, and heavy tanks were also mostly abandoned, the medium tank design evolved into heavier models due to increase in armour and larger sized main weapon resulting in the main battle tank (MBT) which came into existence, combining most of the different types of tanks during World War II.


title: Armoured warfare

text: For the most part the NATO armoured doctrine remained defensive, and dominated by use of nuclear weapons as deterrence. Although most NATO nations began the Cold War period with a large number of U.S.-designed tanks in their fleets, there was a considerable degree of disagreement on the design of future MBTs among the NATO major nations. Both the U.S. and Germany experimented with, but abandoned the missile-armed MBT-70. The M26 Pershing basic design of the United States would evolve until the M60 main battle tank was replaced with the gas-turbine powered M1 Abrams in the 1980s. The British Army also retained a World War II tank design, the Centurion, which proved to be highly successful and was not fully replaced until the 1970s.


title: Armoured warfare

text: The West German "Bundeswehr" decided to develop their own tank in the 1960s, and in the 1970s produced the Leopard I, which was a somewhat lighter design, conforming to German doctrine that emphasised speed over protection. From the same initial collaborative project as the Leopard I, the French series of AMX tanks also emphasised manoeuvre over protection. By the 21st century, most advanced western main battle tanks were built around powerful engines, large 120 mm guns and composite armour.


title: Armoured warfare

text: The Warsaw Pact armoured doctrine was substantially influenced by the developments in the Soviet Army which sought to adopt its existing doctrine evolved during World War II to the nuclear battlefield. In the early 1960s this led to a number of important developments in the armoured forces and their supporting Arms. One important development was the transition of the Second World War use of Cavalry-Mechanised Group (CMG) into the Cold War Operational Manoeuvre Group (OMG) that was designed to exploit breakthroughs to penetrate NATO's defences in depth. This was a culmination of the Deep Battle theory dating to the 1930s.


title: Armoured warfare

text: In 1964 a significant breakthrough in tank design was achieved in the Soviet Union when the T-64 was produced which for the first time used an automatic loader, reducing the crew of the tank to three crewmen. Subsequently, this model, and the later T-72 and T-80 tanks introduced further innovations that influenced armoured warfare by introducing guided missiles into the tank ammunition mix, allowing ATGW fire from standard tank guns. The Soviet Union was also one of the countries that used two Main Battle Tanks: The high-quality T-80s and lower quality T-72s. Modern Soviet tanks, like the ones mentioned, are typically armed with smooth bore guns. Advancements in Soviet tanks include improved Fire Control Systems, strong armour protected by ERA, and defensive countermeasures (such as Shtora-1 and Arena). The most advanced Soviet tank, up until the end of the Cold War, was the T-80U, which shared similar characteristics with the M1A1(Turbine engine, advanced Fire Control Systems, strong armour, and firepower)


title: Armoured warfare

text: Infantry fighting vehicles were first developed in the 1960s with the Soviet Union's BMP-1, for the first time allowing supporting infantry to accompany tanks on a battlefield when nuclear weapon use was expected.


title: Armoured warfare

text: The T-64s and BMP-1s were also joined by the self-propelled guns and more importantly Mi-24 Rotary-wing aircraft capable of firing anti-tank missiles entering production in 1970 which were built and theorised as "flying tanks".


title: Armoured warfare

text: The Soviet tank troops, as they were known in the USSR, included armoured units, armoured training regiments and other formations and units.


title: Armoured warfare

text: M113 armoured personnel carriers proved effective in the terrain of Vietnam against enemy forces which, until 1968, rarely deployed their armour. Though they were soon countered with mines and RPGs, M-113's continued service during the war, primarily evolving into infantry fighting vehicles, known as the "ACAV" (Armoured Cavalry Assault Vehicle); and functioning as a "light tank."


title: Armoured warfare

text: More heavily armed infantry fighting vehicles such as the M2/M3 Bradley Fighting Vehicle would be based on experience with the M113. Gun trucks were also introduced as M35 trucks fitted with armour and guns to protect convoys. In 1968, Communist forces primarily deployed the Soviet built PT-76 light tank.


title: Armoured warfare

text: By 1971, the larger T-54 medium tanks were fielded, proving themselves susceptible to the M-72 LAW rocket, ARVN M41 Walker Bulldog light tanks, as well as the larger M48A3 Pattons. In January 1969, U.S. armoured cavalry units began exchanging their M48A3 Patton tanks for the M551 Sheridan Armoured Airborne Reconnaissance Assault Vehicles; by 1970 over 200 Sheridan tanks were operating in Vietnam.


title: Armoured warfare

text: Tanks rarely work alone; the usual minimum unit size is a platoon (a platoon is the smallest U.S. Army/Marine unit led by an officer, and a component of a company or troop) of three to five tanks. The tanks of the platoon work together providing mutual support: two might advance while covered by the others then stop and provide cover for the remainder to move ahead.


title: Armoured warfare

text: Normally, multiple platoons coordinate with mechanised infantry and use their mobility and firepower to penetrate weak points in enemy lines. This is where the powerful engines, tracks and turrets come into play. The ability to rotate the turret by a full 360° allows coordinated movement within and between platoons, while defending against attacks from multiple directions and engaging troops and vehicles without stopping or slowing down.


title: Armoured warfare

text: When on the defensive, they wait in prepared positions or use any natural terrain elements (such as small hills) for cover. A tank sitting just behind a hill crest ("hull-down") exposes only the top of its turret, with the gun and sensors, to the enemy, leaving the smallest possible target while allowing it to engage the enemy on the other side of the hill. Tanks are usually able to depress the main gun below the horizontal since modern kinetic energy (KE) rounds have nearly flat trajectories. Without this they would be unable to exploit such positions. However, upon cresting a hill, the tank may expose its thinly armoured underside to enemy weapons.


title: Armoured warfare

text: The deposition of armour around a tank is not uniform; the front is typically better armoured than the sides or rear. Accordingly, normal practice is to keep the front towards the enemy at all times; the tank retreats by reversing instead of turning around. Driving backwards away from an enemy is even safer than driving forwards towards them since driving forwards over a bump can throw the front of the tank up in the air, exposing the thin armour of the underside and taking the gun off the target due to its limited angle of depression.


title: Armoured warfare

text: The tracks, wheels and suspension of a tank are outside the armoured hull and are some of the most vulnerable spots. The easiest way to disable a tank (other than a direct hit in a vulnerable area with a full-power anti-tank weapon) is to target the tracks for a "mobility kill" ("m-kill"), or target all external visual aids with rubbery cohesive substances such as melted rubber or blackened high viscosity epoxy resins. Once a tank is disabled it is easier to destroy. This is why side-skirts are an important feature; they can deflect heavy machine-gun bullets and trigger the detonation of high-explosive anti-tank (HEAT) rounds before they strike the running gear. Other vulnerable parts of a typical tank include the engine deck (with air intakes, radiators, etc.) and the turret ring, where the turret joins the hull.


title: Armoured warfare

text: When used defensively, tanks are often sunk into trenches or placed behind earth berms for increased protection. The tanks can fire off a few shots from their defensive position, then retreat (reversing) to another prepared position further back and drive behind the berms or into the trenches there. These positions can be constructed by the tank crews, but preparations are better and quicker if carried out by combat engineers with bulldozers. Overhead protection, even if it is fairly thin, can also be very useful since it can help pre-detonate artillery shells and avoid direct hits from above which can be deadly to tanks, by striking them at their thinnest armour. In short, tank crews find as many ways as possible to augment the armour on their vehicles.


title: Armoured warfare

text: Tanks usually go into battle with a round in the gun, ready to fire, to minimise reaction time when encountering an enemy. The US doctrine calls for this round to be a kinetic energy (KE) round, as the reaction time is most important when meeting enemy tanks, to get the first shot (and possibly the first kill). If troops or light vehicles are encountered, the usual response is to fire this round at them, despite it not being ideal—it is difficult and time-consuming to remove a round which is already in the breech. In this case, after the KE round is fired, a HEAT round would normally be loaded next to continue the engagement.


title: Armoured warfare

text: Tanks can be decisive in city fighting, with the ability to demolish walls and fire medium and heavy machine guns in several directions simultaneously. However, tanks are especially vulnerable in urban combat. It is much easier for enemy infantry to sneak up behind a tank or fire at its sides, where it is most vulnerable. In addition, firing down from multi-story buildings allows shots at the thin upper turret armour and even basic weapons like Molotov cocktails, if aimed at the engine air intakes, can disable a tank. Because of these limits, tanks are difficult to use in city conflicts where civilians or friendly forces might be nearby, since their firepower can't be used effectively.


title: Armoured warfare

text: Tanks and other armoured vehicles are vulnerable to attack from the air for several reasons. One is that they are easily detectable—the metal they are made of shows up well on radar, and is especially obvious if they are moving in formation. A moving tank also produces a lot of heat, noise and dust. The heat makes seeing them on a forward-looking infra-red system easy and the dust is a good visual clue during the day.


title: Armoured warfare

text: The other major reason is that most armoured vehicles have thinner armour on the roof of the turret and on the engine deck, so an anti-tank guided missile (from an attack helicopter or ground-attack jet) hitting them from the top can be deadly even if it has a small warhead. Even a small automatic cannon is powerful enough to penetrate the rear and top sections of the engine compartment of a tank.


title: Armoured warfare

text: Certain aircraft have been developed to attack armoured vehicles. Most notable is the purpose-built Fairchild-Republic A-10 Thunderbolt II, also known as the "Warthog". Although able to carry a number of different missiles and bombs (including anti-tank ordnance such as the AGM-65 Maverick), the A-10's main weapon is a 30 mm GAU-8/A Avenger Gatling gun which is capable of firing 3,900 depleted uranium armour-piercing rounds per minute. The Russian equivalent is the SU-25.


title: Armoured warfare

text: Similarly, a number of helicopter gunships have been designed mainly to engage enemy armoured vehicles. The AH-1Z Viper, AH-64 Apache, HAL Light Combat Helicopter, Denel Rooivalk, Eurocopter Tiger, Ka-50 Black Shark, Mi-28 Havoc, A129 Mangusta and Westland Lynx are examples. Helicopters are very effective against armoured vehicles for many reasons. The AH-64D Longbow Apache, for example, is equipped with an improved sensor suite and weapon systems and the AN/APG-78 Longbow Fire Control Radar dome installed over the main rotor.


title: Armoured warfare

text: Airborne threats can be countered in several ways. One is air supremacy. This is what the United States relies on most, which is demonstrated by their distinct lack of effective short-range, mobile air defence vehicles to accompany armoured units. Most other countries accompany their armoured forces with highly mobile self-propelled anti-aircraft guns such as the German Gepard or the Soviet 9K22 Tunguska, short and medium-range surface-to-air missile systems such as the SA-6, SA-8 and SA-11, or combine both on the same vehicle (the Tunguska for example can also host SA-19 SAM missiles). The usage of anti-aircraft rounds fired from the main gun of a tank has been increasing over the years. An example is the HE-FRAG round from the T-90 which can be detonated at a set distance as determined by its laser range finder.


title: Armoured warfare

text: Armoured warfare is mechanically and logistically intensive and requires extensive support mechanisms. Armoured fighting vehicles require "armoured" vehicles capable of working in the same terrain to support them. These are operated by the appropriate branches of the army, e.g. recovery and maintenance vehicles by the REME and combat engineering vehicles by the RE in the British Army. These include:


title: Armoured warfare

text: For transporting tracked AFVs over highways, heavy transporters are used, since AFVs are prone to malfunction and their tracks also ruin the highways.


title: Armoured warfare

text: While tanks are integral to armoured warfare, when power projection is required, the inability to perform rapid deployment has always been a limit of heavy main battle tanks.


title: Armoured warfare

text: It takes a few weeks to transfer tanks and their supporting equipment by air or sea. Some tanks and armoured vehicles can be dropped by parachute, or carried by cargo airplanes or helicopters. The largest transports can only carry one or two main battle tanks. Smaller transports can only carry or air drop light tanks and APCs such as the M113.


title: Armoured warfare

text: The desire to create air-portable armoured vehicles that can still take on conventional MBTs has usually resulted in ATGM-armed light vehicles or in self-propelled gun style vehicles. The lack of armour protection is offset by the provision of a first-look/first-hit/first-kill capability through the mating of a powerful gun to superior targeting electronics, a concept similar to that of the US tank destroyers of World War II.


title: Armoured warfare

text: Vehicles which have put such considerations into practice include the Stingray light tank, AMX 10 RC and B1 Centauro. Most such US projects to create such vehicles have been abortive, e.g. the M8 Armored Gun System. The most common was the flawed M551 Sheridan light tank. This was an air-portable tank capable of destroying heavier tanks using the revolutionary (for the time) 152 mm CLGP launcher. The combat effectiveness of this tank was limited by the unreliable MGM-51 missile. The latest iteration of the mobile anti-tank gun platform in American service is the M1134 Anti-Tank Guided Missile Vehicle, a Stryker variant equipped with TOW Missiles; most modern militaries operate comparable vehicles.


title: Armoured warfare

text: Though limited conflicts (such as the insurgency in Iraq) rarely involve direct combat between armoured vehicles, the need to defend against insurgent attacks and IEDs has resulted in the application of armour to light vehicles and the continued use of armoured transports, fighting vehicles and tanks.


title: Inmarsat

text: Inmarsat is a British satellite telecommunications company, offering global mobile services. It provides telephone and data services to users worldwide, via portable or mobile terminals which communicate with ground stations through fourteen geostationary telecommunications satellites. Inmarsat's network provides communications services to a range of governments, aid agencies, media outlets and businesses (especially in the shipping, airline and mining industries) with a need to communicate in remote regions or where there is no reliable terrestrial network. The company was listed on the London Stock Exchange until it was acquired by Connect Bidco, a consortium consisting of Apax Partners, Warburg Pincus, the CPP Investment Board and the Ontario Teachers' Pension Plan, in December 2019.


title: Inmarsat

text: On 8 November 2021, a deal was announced between Inmarsat's owners and Viasat, in which Viasat was to purchase Inmarsat.


title: Inmarsat

text: The present company originates from the International Maritime Satellite Organization (INMARSAT), a non-profit intergovernmental organization established in 1979 at the behest of the International Maritime Organization (IMO)—the United Nations maritime body—and pursuant to the Convention on the International Maritime Satellite Organization, signed by 28 countries in 1976. The organisation was created to establish and operate a satellite communications network for the maritime community. In coordination with the International Civil Aviation Organization in the 1980s, the convention governing INMARSAT was amended to include improvements to aeronautical communications, notably for public safety. The member states owned varying shares of the operational business. The main offices were originally located in the Euston Tower, Euston Road, London.


title: Inmarsat

text: In the mid-1990s, many member states were unwilling to invest in improvements to INMARSAT's network, especially owing to the competitive nature of the satellite communications industry, while many recognized the need to maintain the organization's older systems and the need for an intergovernmental organization to oversee public safety aspects of satellite communication networks. In 1998, an agreement was reached to modify INMARSAT's mission as an intergovernmental organization and separate and privatize the organization's operational business, with public safety obligations attached to the sale.


title: Inmarsat

text: In April 1999, INMARSAT was succeeded by the International Mobile Satellite Organization (IMSO) as an intergovernmental regulatory body for satellite communications, while INMARSAT's operational unit was separated and became the UK-based company Inmarsat Ltd. The IMSO and Inmarsat Ltd. signed an agreement imposing public safety obligations on the new company. Inmarsat was the first international satellite organization that was privatized.


title: Inmarsat

text: In 2005, Apax Partners and Permira bought shares in the company. The company was also first listed on the London Stock Exchange in that year. In March 2008, it was disclosed that U.S. hedge fund Harbinger Capital owned 28% of the company. In 2009, Inmarsat completed the acquisition of satellite communications provider Stratos Global Corporation (Stratos) and acquired a 19-percent stake in SkyWave Mobile Communications Inc., a provider of Inmarsat D+/IsatM2M network services which in turn purchased the GlobalWave business from TransCore. Inmarsat won the 2010 MacRobert Award for its Broadband Global Area Network (BGAN) service.


title: Inmarsat

text: Inmarsat at first provided services using Marisat and MARECS, which were launched by the US Navy and ESA respectively. In the early 1990s Inmarsat launched its first dedicated satellite constellation, Inmarsat-2. These satellites provided the Inmarsat-A service for maritime uses. Between 1996 and 1998 Inmarsat's second constellation, Inmarsat-3, was launched. Consisting of five geostationary L-band satellites the constellation provides the Inmarsat-B and Inmarsat-C services, primarily providing low bandwidth communications and safety services for global shipping. Following privatization in 1999 Inmarsat developed and launched the first satellite communications system offering global coverage, BGAN. This service was provided initially through the three Inmarsat-4 satellite launched between 2005 and 2008, and was then extended with the addition of Alphasat in 2013. In the 2010s, Inmarsat began development of the High Throughput Satellite (HTS) constellation Global Xpress, operating in the Ka-band portion of the spectrum. Global Xpress, launched in 2015, offers global satellite capacity to various markets including shipping and aviation. Global Xpress also marks a significant expansion of Inmarsat's commercial operations in the aviation markets. In 2017, Inmarsat launched its first S-band satellite, intended to provide (in association with an LTE ground network) inflight internet access across Europe. In March 2018, Inmarsat partnered with Isotropic Systems to develop a state-of-the-art, all electronic scanning antenna intended to be used with the Global Xpress network.


title: Inmarsat

text: On 20 September 2018, Inmarsat announced its strategic collaboration with Panasonic Avionics Corporation for an initial ten-year period, to provide in-flight broadband for commercial airlines. Inmarsat will be the exclusive provider of Panasonic for connectivity using the Ka-band satellite signal. Inmarsat will now be offering Panasonic's portfolio of services to its commercial aviation customers.


title: Inmarsat

text: In March 2014, Malaysia Airlines Flight 370 disappeared with 239 passengers and crew en route from Kuala Lumpur to Beijing. After turning away from its planned path and disappearing from radar coverage, the aircraft's satellite data unit remained in contact with Inmarsat's ground station in Perth via the IOR satellite (Indian Ocean Region, 64° East). The aircraft used Inmarsat's "Classic Aero" satellite phone service. Analysis of these communications by Inmarsat and independently by other agencies determined that the aircraft flew into the southern Indian Ocean and was used to guide the search for the aircraft.


title: Inmarsat

text: In March 2019 the company's board agreed to recommend a takeover offer of US$3.4 billion from Connect Bidco, a consortium consisting of Apax Partners, Warburg Pincus, the CPP Investment Board and the Ontario Teachers' Pension Plan. On 9 October 2019, Bloomberg reported that the U.K. government was set to approve the takeover with the final consultation for the deal set to conclude on 24 October 2019. In November 2019, Inmarsat rejected an eleventh-hour effort to derail the US$6 billion sale, in which it was accused of ignoring a potential boost to the company's value. Oaktree argued that the recommended offer for Inmarsat failed to take account of the potential value of spectrum assets used by Inmarsat's U.S. partner Ligado. Inmarsat delisted from London Stock Exchange, as the private equity funds took control of the company, on 5 December 2019; at the time, Inmarsat was operating 14 geostationary communications satellites.


title: Inmarsat

text: On 8 November 2021, a $7.3bn deal was announced between Inmarsat's owners, led by Apax and Warburg Pincus, and Viasat in which Viasat would purchase Inmarsat for $850m in cash, issuing approximately 46 million shares of Viasat stock and taking on $3.4bn in debt. Viasat has promised to honour a pledge made by the previous owners, when it was taken private in 2019, that Inmarsat would remain a UK-based company, and for other planned investments.


title: Inmarsat

text: The Inmarsat head office is at Old Street Roundabout in the London Borough of Islington. Aside from its commercial services, Inmarsat provides Global Maritime Distress and Safety System (GMDSS) to ships and aircraft at no charge, as a public service.


title: Inmarsat

text: Services include traditional voice calls, low-level data tracking systems, and high-speed Internet and other data services as well as distress and safety services. The Broadband Global Area Network (BGAN) network provides General Packet Radio Service (GPRS) - type services at up to 800 kbit/s at a latency of 900-1100 ms via an Internet Protocol (IP) satellite modem the size of a notebook computer, while the Global Xpress network offers up to 50 Mbit/s at a latency of 700 ms via antennas as small as 60 cm. Other services provide mobile Integrated Services Digital Network (ISDN) services used by the media for live reporting on world events via videophone, and inflight Internet access via the European Aviation Network.


title: Inmarsat

text: The price of a call via Inmarsat has now dropped to a level where they are comparable to, and in many cases lower than, international roaming costs, or hotel phone calls. Voice call charges are the same for any location in the world where the service is used. Tariffs for calls to Inmarsat country codes vary, depending on the country in which they are placed. Inmarsat primarily uses country code 870 (see below). Newer Inmarsat services use an IP technology that features an always-on capability where the users are only charged for the amount of data they send and receive, rather than the length of time they are connected. In addition to its own satellites, Inmarsat has a collaboration agreement with ACeS regarding handheld voice services.


title: Inmarsat

text: Each satellite is equipped with a single global beam that covers up to one-third of the Earth's surface, apart from the poles. Overall, global beam coverage extends from latitudes of −82 to +82° regardless of longitude.


title: Inmarsat

text: Each regional beam covers a fraction of the area covered by a global beam, but collectively all of the regional beams offer virtually the same coverage as the global beams. Use of regional beams allow user terminals (also called mobile earth stations) to operate with significantly smaller antennas. Regional beams were introduced with the I-3 satellites. Each I-3 satellite provides four to six spot beams; each I-4 satellite provides 19 regional beams.


title: Inmarsat

text: Narrow beams are offered by the three Inmarsat-4 satellites. Narrow beams vary in size, tend to be several hundred kilometres across. The narrow beams, while much smaller than the global or regional beams, are far more numerous and hence offer the same global coverage. Narrow spot beams allow yet smaller antennas and much higher data rates. They form the backbone of Inmarsat's handheld (GSPS) and broadband services (BGAN). This coverage was introduced with the I-4 satellites. Each I-4 satellite provides around 200 narrow spot beams.


title: Inmarsat

text: The Inmarsat I-5 satellites provide global coverage using four geostationary satellites. Each satellite supports 89 beams, giving a total coverage of approximately one-third of the Earth's surface per satellite. In addition, 6 steerable beams are available per satellite, which may be moved to provide higher capacity to selected locations.


title: Inmarsat

text: On 26 November 2019, the first satellite to extend the original 4 satellite first generation Global Xpress constellation was launched from Centre Spatial Guyanais (CSG) by an Ariane 5 launch vehicle.


title: Inmarsat

text: The 870 number is an automatic locator; it is not necessary to know to which satellite the destination Inmarsat terminal is logged-in. SNAC is now usable by all Inmarsat services.


title: Inmarsat

text: Since 18 July 2017, Inmarsat users using the service provided by China Transport Telecommunication & Information Center may apply for 11 digits Chinese mobile phone numbers starting with 1749. An international call function is not required when making phone calls to such numbers from Mainland China.


title: Inmarsat

text: Inmarsat has developed a series of networks providing certain sets of services (most networks support multiple services). They are grouped into two sets, existing and evolved services, and advanced services. Existing and evolved services are offered through land Earth stations which are not owned nor operated by Inmarsat, but through companies which have a commercial agreement with Inmarsat. Advanced services are provided via distribution partners but the satellite gateways are owned and operated by Inmarsat directly.


title: Inmarsat

text: The "BGAN M2M Family" is a set of IP-based services designed for long-term machine-to-machine management of fixed assets, as follows:


title: Inmarsat

text: On 30 June 2008, the European Parliament and the European Council adopted the European's Decision to establish a single selection and authorisation process (ESAP – European S-band Application Process) to ensure a coordinated introduction of mobile satellite services (MSS) in Europe. The selection process was launched in August 2008 and attracted four applications by prospective operators (ICO Global Communications (ICO), Inmarsat, Solaris Mobile (now EchoStar Mobile), and TerreStar).


title: Inmarsat

text: In May 2009, the European Commission selected two operators, Inmarsat Ventures and Solaris Mobile, giving these operators "the right to use the specific radio frequencies identified in the Commission's decision and the right to operate their respective mobile satellite systems". EU Member States now have to ensure that the two operators have the right to use the specific radio frequencies identified in the commission's decision and the right to operate their respective mobile satellite systems for 18 years from the selection decision. The operators are compelled to start operations within 24 months (May 2011) from the selection decision.


title: Inmarsat

text: Inmarsat's S-band satellite programme will deliver mobile multimedia broadcast, mobile two-way broadband telecommunications and next-generation MSS services across all member states of the European Union and as far east as Moscow and Ankara by means of a hybrid satellite/terrestrial network. It was built by Thales Alenia Space and launched in 2017. The complementary ground network consists of around 300 LTE base stations constructed by Deutsche Telekom.


title: Inmarsat

text: The European Aviation Network faces a number of legal challenges. This includes a challenge from Viasat alleging unfair bidding practices and a misuse of spectrum and a ruling by the Belgian telecommunications regulator revoking permission for the use of the ground network in Belgium.


title: Inmarsat

text: Inmarsat ordered a fifth Global Xpress satellite from Thales Group. The satellite launched 26 November 2019 from Centre Spatial Guyanais (CSG) aboard an Ariane 5 launch vehicle. The satellite has been described as a 'very high throughput satellite', and provides services to the Middle East, India and Europe. former CEO Rupert Pearce (new CEO Rajeev Suri) has also indicated that Inmarsat is planning further expansion of the Global Xpress network in the future. Trials of new technologies have demonstrated bandwidths of 330 Mbit/s over the existing Global Xpress network, far in excess of the currently marketed 50 Mbit/s.


title: Inmarsat

text: To provide GX coverage to the growing number of users in the Arctic region, Inmarsat plans to improve GlobalXpress connectivity to above 65° North.


title: Inmarsat

text: Two high-capacity, multi-beam payloads GX-10A and GX-10B will be placed in Highly elliptical orbits (HEO) to ensure reliable coverage. Inmarsat is working in partnership with Space Norway HEOSAT in the Arctic Satellite Broadband Mission. The satellites carrying the Inmarsat payload plan to be manufactured by Northrop Grumman Innovation Systems (NGIS). Launch for GX-10A and 10B are scheduled for 2022.


title: Inmarsat

text: At the end of 2015, Inmarsat ordered two sixth generation satellites from Airbus. These satellites will offer both Ka- and L-band payloads and will provide additional capacity to the existing BGAN and Global Xpress networks. In 2017, it was announced that the first of these satellites will be launched by MHI in December 2021.


title: Inmarsat

text: INMARSAT and Iridium frequency bands abut each other at 1626.5 MHz thus each satcom radio has the ability to interfere with the other. Usually, the far more powerful INMARSAT radio disrupts the Iridium radio up to away.


title: Curtis (50 Cent album)

text: Curtis is the third studio album by American rapper 50 Cent. It was released September 11, 2007, by Shady Records, Aftermath Entertainment, Interscope Records, and Universal Music Group. The album features production from Dr. Dre, Eminem, and Timbaland, among others. Music writers have noted that 50 Cent divides between "hard" and "soft" songs on the album. The album went through many changes in the lead up to its release and was heavily anticipated after the success of 50 Cent's two prior albums, "Get Rich or Die Tryin'" (2003) and "The Massacre" (2005).


title: Curtis (50 Cent album)

text: "Curtis" received generally mixed reviews from music critics upon release. The album debuted at #2 on the US "Billboard" 200 chart, selling 691,000 copies in its first week. After years of slumping sales, the album's competition with Kanye West's "Graduation" (2007) and the resulting record-breaking performances both albums displayed was considered to be a "great day for hip hop."


title: Curtis (50 Cent album)

text: Initially, 50 Cent's 2007 album which was planned to be "Before I Self Destruct". However, he decided to push back its release date to 2008, and instead to release "Curtis" in 2007. The album's title was changed twice. For the first time, it was changed from "Curtis" to "Curtis S.S.K.". The second time, the title of the album was changed back from "Curtis S.S.K." to "Curtis". The "S.S.K.", which stood for "SoundScan Killer", was intended to show the pressure 50 Cent felt to succeed. The "S.S.K." also stands for "SouthSide King" and "Shoot, Stab, Kill". 50 Cent stated that the album was inspired by his life before his commercial debut, "Get Rich or Die Tryin'". He also stated that he chose the album's title because he was known as "Curtis" before he became famous. In January 2007, DJ Whoo Kid predicted the album to be a double disc LP, with one CD having a "crazy club-bangin' ridiculous" theme and the other having a "hard-core killer sh--," theme. However, this did not materialize.


title: Curtis (50 Cent album)

text: 50 Cent wrote parts of the album in his grandmother's old house in South Jamaica, Queens. He flew to Florida to work on the track titled "Ayo Technology" with Justin Timberlake, and the song was finished in Houston, Texas. While "Get Rich or Die Tryin'" and "The Massacre" featured mostly G-Unit and G-Unit Records artists respectively, "Curtis" features artists that 50 Cent has never worked with before, such as Akon, Justin Timberlake, Mary J. Blige, Robin Thicke, Timbaland and Nicole Scherzinger from The Pussycat Dolls. When asked about his choice of working with artists outside of his company, 50 Cent stated, "The album, for me, was finding a space where I am content and comfortable with my career, where I can go off and create with other artists and experiment a little bit". 50 Cent wrote a significant amount of the guests' lyrics. In an interview with "XXL", he said,


title: Curtis (50 Cent album)

text: Stylus Magazine's Jayson Greene writes that "the beats on "Curtis" sound about as dated and cheap as any Koch record", and that "each no-name producer (Veto and Roomio? Jake One?) provides the comfort food they know he'll lap up". Pitchfork Media's Ryan Dombal also comments that 50 Cent "should be able to work with producers who could conjure his hit-making abilities, but instead the MC mostly sticks with tried-and-failed G-Unit stalwarts and Dre-aping up-and-comers that do him few favors". Dave de Sylvia of Sputnikmusic writes of the production on "Ayo Technology", "Timbaland's shred-guitar-goes-keyboard melody is just mesmerising enough to work".


title: Curtis (50 Cent album)

text: RapReviews editor Arthur Gailes states that "there is no dip in quality lyrically; 50 is often criticized for not being a good lyricist, but he's exceptionally witty in his writtens", and adds that 50 Cent "manages to cover different themes very well", noting his "seduction" on "Follow My Lead". Greene writes that 50 Cent is trying to "revisit the raw fatalism that defined the best tracks on "Get Rich or Die Tryin'" ", quoting lyrics from "My Gun Go Off" as an example: "You know tomorrow's just a day away / If you can just keep your heart beatin' and your ass awake".


title: Curtis (50 Cent album)

text: "Curtis" received mixed reviews from music critics. At Metacritic, which assigns a normalized rating out of 100 to reviews from mainstream critics, the album received an average score of 58, based on 15 reviews. Stylus Magazine observed that "there isn’t an ounce of life in "Curtis"". Nathan Rabin of "The A.V. Club" wrote that 50 Cent "has yet to master the art of making a satisfying album rather than delivering a random assortment of demographic-pandering tracks". Allmusic's David Jeffries wrote that "Curtis" "is entertaining but only impressive in that 50 can run in place and still be on top". "The Boston Globe" stated that, "artistically, [Kanye] West is always moving, while 50 is at a standstill". "Chicago Tribune" critic Greg Kot wrote that "at a time when consumers are expressing their dissatisfaction with music-industry product", "Curtis" provides "exactly what they say they don't want: More of the same". Chase Hoffberger of "The Austin Chronicle" found 50 Cent "redundant" and said that the album "tires on second-rate beats, juvenile hooks, and rote lyrics about money and guns." Slant Magazine called 50 Cent "one of the worst lyricists alive", criticizing "Amusement Park"'s lyrics and the execution of his metaphors which he "mumbles without a hint of irony or conviction". Robert Christgau, writing for MSN Music, named it "dud of the month" with a "B" grade and wrote that 50 Cent, "a parvenu mastering pop music for money", has "turned into a made man running on vanity".


title: Curtis (50 Cent album)

text: In a positive review, "USA Today"s Steve Jones wrote that its themes of "chip-stacking and sexual prowess [...] aren’t new", but stated that 50 Cent "delivers them with unmatched swagger and flair". "Rolling Stone" writer Rob Sheffield noted that 50 Cent is "out to prove he's everything he used to claim", and similar to "The Massacre", he "divides between hard songs ('Man Down', 'Fire', 'I'll Still Kill') and soft songs ('Follow My Lead')". Sheffield also noted that 50 Cent is for the first time "letting guests sing most of the hooks". Kelefa Sanneh of "The New York Times" commented that "his mush-mouthed delivery is still charming, and so are his endless provocations". Greg Tate of "The Village Voice" stated, ""Curtis" is stuffed with tightly wound 21st-century pop songwriting, full of that invisible craft and flow that renders a thing eminently listenable even if it's gratuitously raunchy, politically reprehensible, and sexually retrograde."


title: Curtis (50 Cent album)

text: "Time" magazine ranked the single "I Get Money" number six on its list of The 10 Best Songs of 2007. "Time" critic Josh Tyrangiel praised the song as "hypnotic", observing that its appeal is owed to the "Top Billin" sample, and that 50 Cent's bemusement at his own survival and success "makes the song as wry as it is scary". PopMatters editor Josh Timmermann cited "I Get Money" as "the collection's clear MVP, an iron-fisted ode to living large".


title: Curtis (50 Cent album)

text: "Curtis" earned 50 Cent a win for the Best-Selling Hip-Hop Artist category at the 2007 World Music Awards. However, "Entertainment Weekly" placed the album at third place in their list of Worst Albums of 2007.


title: Curtis (50 Cent album)

text: "Curtis" debuted at number two on the US "Billboard" 200 chart, selling 691,000 copies in its first week. It had the fourth highest sales week for an album in 2007 (topping Linkin Park's "Minutes to Midnight" which sold 625,000, then outsold by the Eagles' "Long Road Out of Eden", which moved 711,000 units and later Alicia Keys' "As I Am" bringing in 742,000 copies.) It also had the highest sales week for an album by an East Coast-based artist since Jay-Z's "Kingdom Come" debuted with 680,000 copies sold several months earlier. However, "Curtis" brought in the third-lowest first-week sales of 50 Cent's career, with "Get Rich or Die Tryin'" selling 872,000 and "The Massacre" moving 1.14 million copies.


title: Curtis (50 Cent album)

text: The album sold 143,000 copies in its second week of release in the US, 71,000 copies in its third week, 50,000 copies in its fourth week, 38,000 copies in its fifth week on the chart, and 30,000 copies sold in its sixth week, It sold 24,000 copies in its seventh week, 20,000 in its eighth week, 17,000 in its ninth week, 17,000 in its 10th week, 21,000 in its 11th week, 15,000 in its 12th week, 17,000 in its 13th week, 19,000 in its 14th week, and 25,000 in its 15th week. In the US, "Curtis" ultimately sold 1,225,000 in 2007.


title: Curtis (50 Cent album)

text: In July 2007, Kanye West changed the release date for his third studio album "Graduation" from September 18, 2007, to the same release date as "Curtis", with September 11, 2007. This forced the albums to go head-to-head and compete for higher sales against each other. 50 Cent claimed that if "Graduation" sold more records than "Curtis", he would stop releasing solo albums. However, he later dispelled his comments. When asked again about his threat to retire, 50 Cent stated that, if he were to lose, he will release an album every time a major Def Jam artist releases an album.


title: Curtis (50 Cent album)

text: "Graduation"s first-week sales of 957,000 and "Curtis"s first-week sales of 691,000 served as only the second time since 1991, when Nielsen SoundScan began collecting data, that two albums sold more than 600,000 in a week in the United States; in 1991, Guns N' Roses released "Use Your Illusion I" and "Use Your Illusion II", selling 685,000 and 770,000 copies, respectively. The first-week sales totals of "Graduation" and "Curtis" outsold the first-week sales totals of Guns N' Roses' two albums. 50 Cent would argue that although West sold more units domestically in the US, his album sold more units worldwide. In September 2008, "Billboard" released the one-year sales figures for both albums: "Curtis" finished with sales of 1,336,000, and "Graduation" finished with sales of 2,116,000.


title: Hunters of Dune

text: Hunters of Dune is the first of two books written by Brian Herbert and Kevin J. Anderson to conclude Frank Herbert's original "Dune" series of science fiction novels.


title: Hunters of Dune

text: The cliffhanger ending of Frank Herbert's "" (1985) and his subsequent death in 1986 left some overarching plotlines unresolved. Released on August 22, 2006, "Hunters" continues the story of the danger posed to humanity by a remote, unnamed, but ever-present "great enemy". The novel is based on notes left behind by Frank Herbert, but "Hunters" and its 2007 sequel "Sandworms of Dune" represent the authors' version of what Frank Herbert referred to as Dune 7, his own planned seventh novel in the "Dune" series.


title: Hunters of Dune

text: The first five chapters of the novel were available prior to the novel's publication via free download from the official "Dune" website, released monthly from March until July in 2006.


title: Hunters of Dune

text: For three years, the no-ship "Ithaca" has been in an alternate universe, hiding from the "great enemy". It carries the clones, or gholas, of Duncan Idaho, famous military commander Miles Teg, the Bene Gesserit Sheeana, the last Bene Tleilax Master Scytale, and seven small melange-producing sandworms, as well as a number of other humans. Scytale has shared the secret of producing melange, also called spice, in tanks, because the sandworms do not produce enough to allow the ship to continue travelling. The mysterious Oracle of Time speaks to Duncan and brings the no-ship back into the 'regular' universe. The ship is discovered by the mysterious Daniel and Marty, first mentioned at the end of "Chapterhouse: Dune." They attempt to capture the ship, but it escapes.


title: Hunters of Dune

text: On Chapterhouse, the only remaining source of spice, Murbella, now the leader of the Honored Matres and Bene Gesserit, is attempting to merge the groups into the New Sisterhood and prevent civil war. Desperate for more spice so that their Navigators can travel through space, the Spacing Guild approaches her, but Murbella refuses, threatening to cut them off completely. Unbeknownst to everyone but the Bene Gesserit, the sandworms on Chapterhouse are not producing much melange; the Bene Gesserit are making up the shortfall with their own stockpiles.


title: Hunters of Dune

text: Though the Honored Matres had destroyed all Bene Tleilax worlds, their descendants (the Lost Tleilaxu) have returned from The Scattering. They use the shape-stealing Face Dancers for espionage, until the Face Dancers kill the Tleilaxu Elder Burah and replace him with a duplicate. It is revealed that they have replaced all the Lost Tleilaxu Elders, as well as countless humans on various planets in the Old Empire. Their leader Khrone sends the scribe Uxtal to serve the rebel Honored Matre leader Hellica, who has proclaimed herself Matre Superior and now rules the conquered Bene Tleilax homeworld, Tleilax.


title: Hunters of Dune

text: The desperate Spacing Guild goes to Ix seeking an alternative means of space travel. Khrone and his Face Dancers have secretly infiltrated Ix, plotting to dominate the universe. Working with Daniel and Marty, Khrone offers their advanced navigation technology to the Guild as if it were of Ixian design. The Guild agrees to the development of this technology if they have a monopoly on it.


title: Hunters of Dune

text: Uxtal has been forced to use Tleilaxu axlotl tank technology to produce the adrenaline-enhancing drug used by Honored Matres. Khrone tasks Uxtal to make a ghola of Baron Vladimir Harkonnen, which is as sociopathic as the original. Khrone obtains the blood of Paul Atreides and has Uxtal make a ghola of Paul; he intends to use the ghola of the Baron to twist Paul's ghola into a weapon for Daniel and Marty's conquest of the universe. Later, Guild Navigator Edrik comes to Tleilax seeking Uxtal's knowledge of axlotl tanks; the Navigator fears his kind's obsolescence when the Ixian navigation technology becomes available. He seeks a tank-based source of spice to break the Bene Gesserit monopoly, but everyone believes that technology died with the Tleilaxu Masters. Eventually he accesses the genetic material of deceased Master Waff, and creates several Waff gholas, hoping to recover the lost technology.


title: Hunters of Dune

text: The Tleilaxu sustain their lives indefinitely using gholas; Scytale's current body is dying, and he does not have a replacement. He has only one secret to use as a bargaining tool: a hidden nullentropy capsule containing cells of numerous important historical and legendary figures secretly collected by the Tleilaxu for millennia, as far back as the Butlerian Jihad. The Bene Gesserit have a vicious debate over whether to create gholas of any of these historical figures. A few at a time, the historical gholas are created, and Scytale is given a new body.


title: Hunters of Dune

text: On Chapterhouse, Murbella creates the Valkyries, an elite New Sisterhood strike force. They successfully attack rebel Honored Matre strongholds on other planets, discovering that some of the Honored Matres are disguised Face Dancers. Murbella accesses the Other Memory from her Honored Matre ancestors and learns their true origins: they were vengeful Tleilaxu females, freed and assimilated by Fish Speakers and Bene Gesserit fleeing in The Scattering. Tleilaxu females had been enslaved for use as axlotl tanks by Tleilaxu males for millennia. These origins have been forgotten; Murbella now understands why the Honored Matres annihilated the Tleilaxu worlds in the Old Empire. Murbella also accesses a memory showing the origins of the mysterious force the Honored Matres call the Enemy.


title: Hunters of Dune

text: On the no-ship, rebel Bene Gesserit attempt to murder the Leto II ghola, but are foiled when he transforms into a sandworm. The Paul ghola steals and consumes an overdose of spice in an attempt to remember his past, but instead has a vision of being stabbed by an evil version of himself. After being discovered by the Bene Gesserit, he concludes that he has regained prescience. Sheeana has visions that suggest the use of the gholas is dangerous, and halts the program until she knows more.


title: Hunters of Dune

text: Daniel and Marty tell Khrone to discard the Baron Harkonnen and Paul Atreides gholas, as they have lured the "Ithaca" into a trap, and will soon capture the ghola of Paul Atreides on board. Working to his own ends, Khrone continues to prepare the gholas, restoring the Baron's memories and instructing him to train the Paul ghola, which he renames Paolo. Paolo does not yet have his memories.


title: Hunters of Dune

text: Murbella contracts Ix's competitor Richese to provide armaments for a confrontation with the great enemy, but the rebel Honored Matres destroy the planet to cripple the Sisterhood. Murbella and her Valkyries successfully assault Tleilax, the most powerful of the rebel Honored Matre strongholds, and discover that many, including Matre Superior Hellica, were Face Dancers. Uxtal dies trying to escape, but the remaining Waff ghola finds refuge with the Spacing Guild, offering Edrik the genetic knowledge for the Guild to create their own sandworms.


title: Hunters of Dune

text: The "Ithaca" stumbles upon the homeworld of the Handlers. An exploratory party from the no-ship discovers that the Handlers are actually Face Dancers, and barely escape back to the ship. Some Face Dancer ships crash into the "Ithaca", and the chaos makes it impossible to know if any passengers have been replaced by Face Dancers. The emergency forces Miles Teg to reveal his hidden power of superhuman speed.


title: Hunters of Dune

text: Murbella, now in complete control of the Honored Matres and Bene Gesserit, prepares a defense against the forces of the great enemy, now identified by Other Memory to be thinking machines of Omnius, the machine overlord destroyed in the ancient Butlerian Jihad. The Oracle of Time is revealed to be the living consciousness of Norma Cenva, somehow also still in existence millennia after the Jihad.


title: Hunters of Dune

text: Daniel and Marty are revealed to be Omnius and the independent robot, Erasmus. Before its destruction, the Omnius incarnation on Giedi Prime had launched 5,000 probes capable of constructing new machine colonies on any planets encountered. One of these probes eventually intercepted a signal transmitted by the last remaining Omnius on Corrin before it too was destroyed. Its forces and Synchronized Empire finally reassembled, the new version of the Evermind is on the way back to the Old Empire to destroy all humanity.


title: Hunters of Dune

text: "The New York Times" said of "Hunters of Dune" that "Brian Herbert and Kevin J. Anderson go through the motions, but they don't often seem to be having much fun with their material ... by the end of "Hunters", they have done little more than set the table for "Sandworms of Dune"."


title: The Crow: City of Angels

text: The Crow: City of Angels is a 1996 American superhero film directed by Tim Pope from a screenplay by David S. Goyer. It is a sequel to the 1994 film "The Crow" and the second installment in "The Crow" film series.


title: The Crow: City of Angels

text: In Los Angeles, drug kingpin Judah Earl murders mechanic Ashe Corven and his eight-year-old son Danny after they witness a gang of Judah's henchmen murdering a fellow drug dealer, with his gang dumping Ashe and Danny's bodies into the harbor.


title: The Crow: City of Angels

text: Sarah from "The Crow" is now an adult, working in a tattoo parlor by day and painting surreal images of death and resurrection in her apartment at night. She is haunted by disturbing dreams about Ashe and Danny. After a day's work in the tattoo parlor, Sarah is visited in her apartment by a large crow as she contemplates a ring that Eric Draven gave her.


title: The Crow: City of Angels

text: Sarah follows the crow to the harbor at night on All Saints' Day, and witnesses Ashe's resurrection and frantic escape from his watery grave before taking him to her apartment. When Sarah tells Ashe he is dead, he panics and runs screaming into the night, ending up at his own home, where he relives the final moments of his life.


title: The Crow: City of Angels

text: Sarah arrives there to find Ashe brooding, and she explains that the Crow resurrected him so that he can exact revenge on the criminals who killed him and Danny. Guided by the crow, Ashe starts killing Judah's henchmen, one by one. Ashe first visits Spider-Monkey in a drug warehouse and interrogates him as to who else was involved in the murders before killing him by blowing up the building. Another of Judah's lackeys, Nemo, is spending the night at a peeping booth. Ashe appears in the booth and kills him, leaving a doll stuffed in his pants and a paper crow in his mouth.


title: The Crow: City of Angels

text: Judah has employed a blind prophetess named Sybil who is able to ascertain Ashe's link to Sarah and to the crow that is the source of his powers. Judah captures Sarah in order to draw Ashe to him and steal his power.


title: The Crow: City of Angels

text: One of the murderers, Kali, goes to Sarah's apartment to draw Ashe out. While battling her, Ashe realizes that Kali is the one who killed Danny; enraged, he throws her against a wall that breaks her leg, and then out a window to her death, leaving a crow-shaped blood pattern. Ashe then pursues Judah's right-hand-man, Curve, in a motorcycle chase. Ashe shoots Curve's motorcycle, which blows up and throws Curve onto the road. Ashe then drags Curve into the nearby river, leaving him to die as parishioners cast down flower petals in the shape of a crow.


title: The Crow: City of Angels

text: During the Day of the Dead festival, Judah captures the crow and impales its wings with knives before killing it. He then ingests the crow's blood, stealing Ashe's power. Suddenly mortal, Ashe nearly dies from the shock, but is revived after seeing a vision of Danny telling him to keep fighting. Ashe attempts to rescue Sarah by seeking out Judah in his lair, an abandoned church. Judah overpowers the weakened Ashe in the ensuing fight, tying a rope around him and savagely whipping him, intending to hang him.


title: The Crow: City of Angels

text: Sarah rushes up and stabs Judah in the forehead, causing Judah to drop Ashe. Judah pulls out the knife and starts moving toward Ashe. When Sarah intervenes, Judah stabs her in the stomach. Ashe gets up and impales Judah on a metal pipe, which fails to kill him. Ashe calls upon a murder of crows that devour Judah. Sarah dies from her stab wound, a tableau reminiscent of a painting she completed earlier. Ashe returns to death, knowing that he can rest in peace with Sarah, and his son.


title: The Crow: City of Angels

text: "The Crow: City of Angels" opened at number 1 at the U.S. and Canada box office grossing $9,785,111 during its opening weekend, a record for the Labor Day Weekend. Its weekend accounted for 54.6% of its total gross. It also opened at number 1 in the UK. The final US and Canadian gross was $17.9 million.


title: The Crow: City of Angels

text: On Rotten Tomatoes the film has an 11% approval rating based on 35 reviews, with an average rating of 3.4/10. The site's consensus states: ""The Crow: City of Angels" is a sloppy pretender that captures neither the mood nor energy of the original."


title: The Crow: City of Angels

text: Owen Gleiberman of Entertainment Weekly gave it grade "D" and wrote: "Even for teens hooked on the grandiloquence of death-metal masochism, the movie may seem closer to an endless Sunday in church."


title: The Crow: City of Angels

text: The film's Blu-ray that was released by Echo Bridge Entertainment has been criticized as not being up to high-definition standards. It was further criticized for being erroneously labeled as 1080p when the film was, in fact, presented in 1080i.


title: The Crow: City of Angels

text: The film was released on VHS on December 3, 1996. In 1998, the film was released on DVD. In 2001, a collector's edition was released, labeled "exclusive Director's Cut", which restored 11 minutes of extended footage and included two featurettes and an audio commentary.


title: The Crow: City of Angels

text: The film was re-released in 2011 by Echo Bridge Home Entertainment as a double feature, paired up with "". The only special feature was the widescreen format. There was also a single feature release under the same company.


title: The Crow: City of Angels

text: The film was released as a part of a boxset with "The Crow: Salvation" in the UK with 1080p picture and DTS-MA 5.1 sound. The only special features were 2 featurettes from the collector's edition.


title: The Crow: City of Angels

text: On September 11, 2012, Echo Bridge released another Blu-ray release of the film (once again, a double feature with ""). It was already being sold at Walmart stores before its official release date had been reached. This version contained bonus material not present in the original Blu-ray release.


title: The Crow: City of Angels

text: On October 7, 2014, it was released on DVD by Lionsgate in a triple feature edition with the other two "Crow" sequels.


title: The Crow: City of Angels

text: The screenplay for "City of Angels" was adapted into a novel by Chet Williamson as well as a three-issue comic book series published by Kitchen Sink Press. Both feature the original ending of the story, in which Ashe wanders the earth as an undead spirit.


title: The Crow: City of Angels

text: A video game tie-in "" was made for the PlayStation, Sega Saturn, and Microsoft Windows. The game was to be initially released around the same time as the film but instead released in early 1997.


title: Bernie Casey

text: Bernard Terry Casey (June 8, 1939 – September 19, 2017) was an American actor, poet and professional American football player.


title: Bernie Casey

text: Casey was born in Wyco, West Virginia, the son of Flossie (Coleman) and Frank Leslie Casey. He graduated from East High School in Columbus, Ohio.


title: Bernie Casey

text: Casey was a record-breaking track and field athlete for Bowling Green State University and helped the 1959 football team win a small college national championship. Casey earned All-America recognition and a trip to the finals at the U.S. Olympic Trials in 1960. In addition to national honors, he won three consecutive Mid-American Conference titles in the high-hurdles, 1958–60.


title: Bernie Casey

text: Casey was the ninth overall selection of the 1961 NFL Draft, taken by the San Francisco 49ers. He played eight NFL seasons (several positions, first five seasons mainly a halfback, last three seasons a flanker (setback wide receiver)): six with the 49ers and two with the Los Angeles Rams. His best-known play came in 1967 for the Rams in the penultimate game of the regular season against the Green Bay Packers. The Rams needed to win to keep their division title hopes alive, but trailed 24–20 with under a minute to play. Facing fourth down, the Packers lined up to punt, but Tony Guillory blocked the Donny Anderson punt and Claude Crabb returned it to the Packer five-yard line. After an incomplete pass, Casey caught the winning touchdown pass from Roman Gabriel with under thirty seconds to play to give the Rams a 27–24 victory. The Rams defeated the Baltimore Colts the following week to win the Coastal Division title at 11–1–2.


title: Bernie Casey

text: Casey began his acting career in the film "Guns of the Magnificent Seven", a sequel to "The Magnificent Seven". Then he played opposite fellow former NFL star Jim Brown in the crime dramas "...tick...tick...tick..." and "Black Gunn". He played a leading role in the 1972 science fiction TV film "Gargoyles". He also played Tamara Dobson's love interest in 1973's "Cleopatra Jones".


title: Bernie Casey

text: From there he moved between performances on television and the big screen such as playing team captain for the Chicago Bears in the TV film "Brian's Song". In 1979, he starred as widower Mike Harris in the NBC television series "Harris and Company", the first weekly American TV drama series centered on a black family. In 1980, he played Major Jeff Spender in the television mini-series "The Martian Chronicles", based on the novel by Ray Bradbury.


title: Bernie Casey

text: In 1981, Casey played a detective opposite Burt Reynolds in the feature film "Sharky's Machine", directed by Reynolds. He reunited with Reynolds a few years later for the crime story "Rent-a-Cop".


title: Bernie Casey

text: In 1983, he played the role of CIA agent Felix Leiter in the non-Eon Productions James Bond film "Never Say Never Again". He co-starred in "Revenge of the Nerds" and had a comedic role as Colonel Rhombus in the John Landis film "Spies Like Us". Casey also appeared in the movie "Hit Man".


title: Bernie Casey

text: Also during his career, he worked with such well-known directors as Martin Scorsese in his 1972 film "Boxcar Bertha" and appeared on such television series as "The Streets of San Francisco".


title: Bernie Casey

text: He played a version of himself, and other football players turned actors, in Keenen Ivory Wayans's 1988 comedic film "I'm Gonna Git You Sucka". He played the national head of a black fraternity in 1984's "Revenge of the Nerds". He played high school history teacher Mr. Ryan, in "Bill & Ted's Excellent Adventure", released in 1989. Casey appeared as a very influential prisoner with outside connections in Walter Hill's "Another 48 Hrs.". In 1992, he appeared as a Naval officer on the battleship USS "Missouri" in "Under Siege".


title: Bernie Casey

text: In 1994, Casey guest-starred in a two-episode story arc in "" as the Maquis leader Lieutenant Commander , and in 1995 as a guest-star on both "SeaQuest 2032" as Admiral VanAlden and "Babylon 5" as Derek Cranston. In 2006, he co-starred in the film "When I Find the Ocean" alongside such actors as Lee Majors.


title: Bernie Casey

text: Casey enjoyed painting and writing poetry. "Look at the People", a book of his paintings and poems, was published by Doubleday in 1969. He died at Cedars-Sinai Medical Center in Los Angeles on September 19, 2017, after a stroke.


title: Knight Rider

text: Knight Rider is an American entertainment franchise created by Glen A. Larson. The core of "Knight Rider" is its three television series: the original "Knight Rider" (1982–1986) and sequel series "Team Knight Rider" (1997–1998) and "Knight Rider" (2008–2009). The franchise also includes three television films, a short-lived spinoff series, computer and video games, and novels, as well as KnightCon, a "Knight Rider" convention. Beginning with the original television series and continuing with the subsequent films and series, the franchise has developed a cult following and spawned many pop culture references.


title: Knight Rider

text: The original "Knight Rider" series followed the adventures of Michael Knight, a modern-day crime fighter who uses a technologically advanced, artificially intelligent automobile. This car, named KITT, is virtually indestructible, due to a high-tech coating applied to it. "Knight Rider" stories usually depict either average citizens, or ethical heads of corporations, being bullied into subservience to an overbearing or ruthless criminal organization. The protagonist(s) of each particular series is instructed by the Foundation for Law and Government (FLAG) to assist in some manner. The protagonist(s) has the assistance of a high-tech, self-aware, and nearly indestructible vehicle.


title: Knight Rider

text: The series debuted in 1982 and ran for four seasons on NBC. These adventures were continued with the television films "Knight Rider 2000" and "Knight Rider 2010" and the short-lived "Team Knight Rider". One other television movie, "Knight Rider", served as a pilot for the 2008 television series "Knight Rider". In 1985, a spin-off series, "Code of Vengeance", also premiered.


title: Knight Rider

text: Three television series make up the bulk of the "Knight Rider" mythos: "Knight Rider" (1982–1986), "Team Knight Rider" (1997–1998), and "Knight Rider" (2008–2009). There also was a spin-off series, "Code of Vengeance", that ran for one season (1985–1986). In total, 133 "Knight Rider" episodes have been produced across the seven seasons of the four various TV series.


title: Knight Rider

text: The original "Knight Rider" series saw Michael Knight (David Hasselhoff), a crime fighter who uses a high tech, artificially intelligent automobile, the Knight Industries Two Thousand (KITT). This car is a virtually indestructible weapon that fights for justice, and is voiced by actor William Daniels. The show was created and produced by Glen A. Larson, and was originally broadcast on NBC from 1982 to 1986. The show has 90 episodes over four seasons.


title: Knight Rider

text: The two-part episode "Knight Rider" episode "Mouth of the Snake", was a backdoor pilot for a 1984 series to be called "All That Glitters". Rejected by NBC, the lead character and actor were recycled for a short-lived 1985–1986 series titled "Code of Vengeance", in it, David Dalton (Charles Taylor), a Vietnam veteran-turned-drifter, travels across the United States in a camper van, with only his dog for company. Dalton involves himself in the personal lives of people he meets. In a similar fashion to "Knight Rider", he uses his fighting skills to help them gain justice over their enemies. The Dalton character was retooled for the planned spin-off series, whose pilot, "Code of Vengeance", was a surprise ratings success in June 1985. A subsequent series, to be called "Dalton", was ordered by NBC for midseason, then production was cancelled after just four episodes were completed. These aired in the summer of 1986 as a television movie titled "Dalton: Code of Vengeance II" and as a part of a fill-in series called "Dalton's Code of Vengeance".


title: Knight Rider

text: "Team Knight Rider" is set ten years after the original series, with the Foundation for Law and Government (FLAG) using a team of five "highly skilled operatives" to do the job that Michael Knight used to do. They are Kyle Stewart (Brixton Karnes), Jenny Andrews (Christine Steel), Duke DePalma (Duane Davis), Erica West (Kathy Trageser), and Kevin "Trek" Sanders, (Nick Wechsler). In one of the episodes it is implied that Jenny Andrews is the daughter of Michael Knight. However, it is never confirmed. The series was created by writer/producers Rick Copp and David A. Goodman, and was distributed by Universal Domestic Television. It ran for a single season of 22 one-hour episodes before it was canceled due to poor ratings.


title: Knight Rider

text: The new "Knight Rider" series followed Michael "Mike" Jordan, the estranged son of Michael Knight, as he takes up the mantle of the FLAG driver. This time, he is driving the Knight Industries Three Thousand, also known as "KITT". The series stars Justin Bruening as Mike Traceur/Knight, and Deanna Russo as Sarah Graiman, Traceur's former girlfriend and love interest. Sarah is the daughter of Charles Graiman. Graiman, played by Bruce Davison, is the creator of a new generation of KITT, which is voiced by Val Kilmer. On May 19, 2009, NBC announced that "Knight Rider" was canceled after one season because of poor ratings.


title: Knight Rider

text: In 2016, it was announced that Machinima, YOMYOMF and NBCUniversal Brand Development are developing a "Knight Rider" reboot with Justin Lin producing and directing the series.


title: Knight Rider

text: "Knight Rider 2000" is a television sequel movie to the original "Knight Rider" series. It aired on May 19, 1991. It was directed by Alan J. Levi and written by Rob Hedden and Glen A. Larson. The movie sees Michael Knight (David Hasselhoff) teaming up once again with Devon Miles (Edward Mulhare) in a near future science fiction setting. He is also paired up with a new supercar, the "Knight 4000" to combat Thomas J. Watts (Mitch Pileggi), a former police officer turned psychotic killer. The movie also starred Susan Norman as Officer Shawn McCormick, and Carmen Argenziano as Russell Maddock (and the voice of the Knight 4000). The movie was developed as a pilot for a proposed new series, but despite high ratings, the plan was abandoned.


title: Knight Rider

text: "Knight Rider 2010" is a television movie loosely based on the original "Knight Rider" series. It aired on February 13, 1994. It was directed by Sam Pillsbury and written by John Leekley. The movie is set in a "Mad Max"-style future where Jake McQueen (Richard Joseph Paul) is a smuggler who is contacted by Hannah Tyree (Hudson Leick), an employee of the Chrysalis Corporation, who want him to work for them as part of their video games division. Jake fights the evil Jared (Brion James). Hannah's consciousness is uploaded into a computer that Jake then installs in his Mustang. The movie was broadcast as part of Universal Television's Action Pack.


title: Knight Rider

text: "Knight Rider" is a 2008 television film which was created to serve as a backdoor pilot for the new "Knight Rider" television series, and aired on February 17, 2008. The serves as a direct sequel to the original series and ignores the "Knight Rider 2000" film and the "Team Knight Rider" television series. It was directed by Steve Shill and written by David Andron and Glen A. Larson. The movie sees Mike Traceur (Justin Bruening) teaming up his childhood friend, Sarah Graiman (Deanna Russo), her father Charles Graiman (Bruce Davison), and Special Agent Carrie Rivai (Sydney Tamiia Poitier) to fight evil, he is paired up with a new KITT, the Knight Industries Three Thousand. The movie was a success and resulted in a new series.


title: Knight Rider

text: "Knight Rider" is a 1986 video game by Ocean Software that was released in Europe for several computer platforms.


title: Knight Rider

text: "Knight Rider" is a racing video game for the Nintendo Entertainment System that is very loosely based on the television show of the same name. It was developed by Pack-In-Video and published by Acclaim Entertainment. The game sees KITT having to travel between fifteen cities that are featured, starting with San Francisco and ending in Los Angeles.


title: Knight Rider

text: is a video game for the PC-Engine based on the 1980s television series "Knight Rider". It was produced by and published by Pack-In Video Co. Ltd on December 16, 1994 in Japan only. The game has a series of levels and each one requires that KITT be navigated through and around various cars, big rig trucks, and other obstacles in order to reach their destination on each level.


title: Knight Rider

text: "Knight Rider: The Game" is a video game based on the original television series of the same name. It was developed by Davilex Games and distributed by Tri Synergy, and was released on November 22, 2002. The game allows the player to take control of KITT – the Knight Industries Two Thousand, in a range of missions including, racing, exploring, chasing and others. The player also meets famous villains from the original series, including KARR and Garthe Knight.


title: Knight Rider

text: "Knight Rider: The Game 2" is a video game sequel to "Knight Rider: The Game", which was again developed by Davilex Games and was published by Koch Media on November 5, 2004, for PC and PlayStation 2.


title: Knight Rider

text: The "Knight Rider" franchise has a number of novels, video games, and other materials that cover many aspects of the various series and films.


title: Knight Rider

text: Various toy versions of KITT were released and produced solid profits. The more notable of the "Knight Rider" memorabilia includes the remote controlled KITT, the Knight Rider lunch box, and the deluxe version of KITT. This final model, sold by Kenner Toys and dubbed the "Knight Rider Voice Car", spoke electronically, using a recording of the voice of William Daniels, featured a detailed interior and a Michael Knight action figure as well.


title: Knight Rider

text: Also in the 1980s a Key Car of KITT was released. But it had no scanner and the windows were black with "Knight 2000" written in red letter on the doors. It included a key which was pushed into a hole below KITTs spoiler compressing a spring; then snaps into place. Squeezing the key releases it and the spring shoots the car forward.


title: Knight Rider

text: As with many popular series of the era (including "The Dukes of Hazzard", "The A-Team" etc.), ERTL released die-cast toys of KITT in three different sizes – the common miniature model, a "medium" model, and a large model. These toys featured red reflective holograms on the nose to represent the scanner (however, they were located on the point of the nose, rather like the early mock-up of KITT seen in the pilot episode) as opposed to altering the basic model design to incorporate the scanner as commonly seen in the series. The toys also included round steering wheels as opposed to KITT's steering yoke.


title: Knight Rider

text: Also in late 2004, die-cast models of KITT and KARR were produced from ERTL, complete with detailed interior and illuminated moving scanner, just like in the series.


title: Knight Rider

text: In September 2006, Hitari, a UK-based company that produces remote control toy cars, released the "Knight Rider" KITT remote control car in 1/15 scale, complete with the working red scanner lights, KITT's voice from the television show and the car's turbine engine sound with the "whoosh whoosh" scanner sound effect.


title: Knight Rider

text: In December 2012, Diamond Select Toys released a talking electronic 1/15 scale KITT that features an illuminated dashboard, scanner, fog lights and tail lights, along with the original voice of KITT, William Daniels, all at a push of a button. An Entertainment Earth exclusive version of that Diamond Select Toys 1/15 KITT, exclusive, as it will include an in scale figure of Michael Knight to go with the car, was released in February 2013 and was available exclusively at Entertainment Earth's Web site. Diamond Select Toys will also was to be releasing an 8-inch figure of Michael Knight with the likeness of David Hasselhoff, which was to be released in March 2013.


title: Knight Rider

text: In February 2013, Hot Wheels released a 1/18 die-cast of KITT as part of their die-cast Elite series of vehicles under their Cult Classics Collection. This one from Hot Wheels was an improvement over the one ERTL released back in 2004. With sharper attention to details on the dashboard, the model features an improved light up red scanner, opening doors and rear hatch, as well as an engine hood which opens up to reveal a detailed Knight 2000 turbine engine which is exclusive to the model and was never shown in the TV series. Additional features include pop up headlights, revolving license plates, ejector seats, removable t-tops and a foldable rear seat.


title: Knight Rider

text: A "Fun Pack" based on "Knight Rider" for the toys-to-life video game "Lego Dimensions" was released in February 2017. The pack includes a Michael Knight minifigure and constructible KITT, and unlocks additional "Knight Rider"-themed content in the game.


title: Knight Rider

text: In 2016, ""s "Zombies" mode features David Hasselhoff reprising his role as Michael Knight, appearing as the games map "Zombies in Spaceland"'s DJ. The "Knight Rider" theme plays in game and many references to the series and KITT are made.


title: Knight Rider

text: In March 2002, Revolution Studios announced a partnership with Mayhem Pictures to create a film adaptation of the television series. The film would be re-designed to be similar to Revolution's previous project, "XXX". Series creator Glen A. Larson was hired to write the first script draft, with the series' lead actor David Hasselhoff attached as an advisor and also have an onscreen role. In April 2003, Revolution Studios hired screenwriters David Elliott and Paul Lovett to pen the film's script. In April 2004, the premise of the film was described as having Hasselhoff reprise his role as Michael Knight, now the mentor to the protagonist as Devon Miles mentored Knight in the television series. The protagonist would be Knight's son, inheriting his father's role and driving the vehicle KITT. The producers' choice for the role was actor Ben Affleck.


title: Knight Rider

text: In May 2006, The Weinstein Company acquired film rights to adapt "Knight Rider" from series creator Larson. He expressed his interest in the film adaptation as a potential franchise property. The following September, Hasselhoff invited actor Orlando Bloom to portray Knight's son in the film adaptation, but Bloom turned down the offer. In April 2007, Hasselhoff said, that the film was in development at Miramax, and that he would at least have a cameo in the film.


title: Knight Rider

text: On June 26, 2013, Brad Copeland was writing a script for a "Knight Rider" film after beating out Travis Beacham, Alex Kurtzman and Roberto Orci.


title: Knight Rider

text: On February 13, 2014, Schmoes Know reports that actors Chris Pratt and Danny McBride are in talks for roles and may use a sort of action-comedy hybrid in the same vein as "21 Jump Street".


title: Knight Rider

text: In December 2015, a media report indicated that a new web series named "Knight Rider Heroes" was in the works and will include David Hasselhoff. This concept was never completed or released. The project is believed to be abandoned.


title: Knight Rider

text: In August 2020, Deadline reported that Spyglass Media Group has teamed with Atomic Monster’s James Wan and Michael Clear to develop the film with Judson Scott serving as executive producer and TJ Fixman adapting the screenplay.


title: Drug metabolism

text: Drug metabolism is the metabolic breakdown of drugs by living organisms, usually through specialized enzymatic systems. More generally, xenobiotic metabolism (from the Greek xenos "stranger" and biotic "related to living beings") is the set of metabolic pathways that modify the chemical structure of xenobiotics, which are compounds foreign to an organism's normal biochemistry, such as any drug or poison. These pathways are a form of biotransformation present in all major groups of organisms and are considered to be of ancient origin. These reactions often act to detoxify poisonous compounds (although in some cases the intermediates in xenobiotic metabolism can themselves cause toxic effects). The study of drug metabolism is called pharmacokinetics.


title: Drug metabolism

text: The metabolism of pharmaceutical drugs is an important aspect of pharmacology and medicine. For example, the rate of metabolism determines the duration and intensity of a drug's pharmacologic action. Drug metabolism also affects multidrug resistance in infectious diseases and in chemotherapy for cancer, and the actions of some drugs as substrates or inhibitors of enzymes involved in xenobiotic metabolism are a common reason for hazardous drug interactions. These pathways are also important in environmental science, with the xenobiotic metabolism of microorganisms determining whether a pollutant will be broken down during bioremediation, or persist in the environment. The enzymes of xenobiotic metabolism, particularly the glutathione S-transferases are also important in agriculture, since they may produce resistance to pesticides and herbicides.


title: Drug metabolism

text: Drug metabolism is divided into three phases. In phase I, enzymes such as cytochrome P450 oxidases introduce reactive or polar groups into xenobiotics. These modified compounds are then conjugated to polar compounds in phase II reactions. These reactions are catalysed by transferase enzymes such as glutathione S-transferases. Finally, in phase III, the conjugated xenobiotics may be further processed, before being recognised by efflux transporters and pumped out of cells. Drug metabolism often converts lipophilic compounds into hydrophilic products that are more readily excreted.


title: Drug metabolism

text: The exact compounds an organism is exposed to will be largely unpredictable, and may differ widely over time; these are major characteristics of xenobiotic toxic stress. The major challenge faced by xenobiotic detoxification systems is that they must be able to remove the almost-limitless number of xenobiotic compounds from the complex mixture of chemicals involved in normal metabolism. The solution that has evolved to address this problem is an elegant combination of physical barriers and low-specificity enzymatic systems.


title: Drug metabolism

text: All organisms use cell membranes as hydrophobic permeability barriers to control access to their internal environment. Polar compounds cannot diffuse across these cell membranes, and the uptake of useful molecules is mediated through transport proteins that specifically select substrates from the extracellular mixture. This selective uptake means that most hydrophilic molecules cannot enter cells, since they are not recognised by any specific transporters. In contrast, the diffusion of hydrophobic compounds across these barriers cannot be controlled, and organisms, therefore, cannot exclude lipid-soluble xenobiotics using membrane barriers.


title: Drug metabolism

text: However, the existence of a permeability barrier means that organisms were able to evolve detoxification systems that exploit the hydrophobicity common to membrane-permeable xenobiotics. These systems therefore solve the specificity problem by possessing such broad substrate specificities that they metabolise almost any non-polar compound. Useful metabolites are excluded since they are polar, and in general contain one or more charged groups.


title: Drug metabolism

text: The detoxification of the reactive by-products of normal metabolism cannot be achieved by the systems outlined above, because these species are derived from normal cellular constituents and usually share their polar characteristics. However, since these compounds are few in number, specific enzymes can recognize and remove them. Examples of these specific detoxification systems are the glyoxalase system, which removes the reactive aldehyde methylglyoxal, and the various antioxidant systems that eliminate reactive oxygen species.


title: Drug metabolism

text: The metabolism of xenobiotics is often divided into three phases:- modification, conjugation, and excretion. These reactions act in concert to detoxify xenobiotics and remove them from cells.


title: Drug metabolism

text: In phase I, a variety of enzymes act to introduce reactive and polar groups into their substrates. One of the most common modifications is hydroxylation catalysed by the cytochrome P-450-dependent mixed-function oxidase system. These enzyme complexes act to incorporate an atom of oxygen into nonactivated hydrocarbons, which can result in either the introduction of hydroxyl groups or N-, O- and S-dealkylation of substrates. The reaction mechanism of the P-450 oxidases proceeds through the reduction of cytochrome-bound oxygen and the generation of a highly-reactive oxyferryl species, according to the following scheme:


title: Drug metabolism

text: Phase I reactions (also termed nonsynthetic reactions) may occur by oxidation, reduction, hydrolysis, cyclization, decyclization, and addition of oxygen or removal of hydrogen, carried out by mixed function oxidases, often in the liver. These oxidative reactions typically involve a cytochrome P450 monooxygenase (often abbreviated CYP), NADPH and oxygen. The classes of pharmaceutical drugs that utilize this method for their metabolism include phenothiazines, paracetamol, and steroids. If the metabolites of phase I reactions are sufficiently polar, they may be readily excreted at this point. However, many phase I products are not eliminated rapidly and undergo a subsequent reaction in which an endogenous substrate combines with the newly incorporated functional group to form a highly polar conjugate.


title: Drug metabolism

text: A common Phase I oxidation involves conversion of a C-H bond to a C-OH. This reaction sometimes converts a pharmacologically inactive compound (a prodrug) to a pharmacologically active one. By the same token, Phase I can turn a nontoxic molecule into a poisonous one (toxification). Simple hydrolysis in the stomach is normally an innocuous reaction, however there are exceptions. For example, phase I metabolism converts acetonitrile to HOCHCN, which rapidly dissociates into formaldehyde and hydrogen cyanide.


title: Drug metabolism

text: Phase I metabolism of drug candidates can be simulated in the laboratory using non-enzyme catalysts. This example of a biomimetic reaction tends to give products that often contains the Phase I metabolites. As an example, the major metabolite of the pharmaceutical trimebutine, desmethyltrimebutine (nor-trimebutine), can be efficiently produced by in vitro oxidation of the commercially available drug. Hydroxylation of an N-methyl group leads to expulsion of a molecule of formaldehyde, while oxidation of the O-methyl groups takes place to a lesser extent.


title: Drug metabolism

text: Cytochrome P450 reductase, also known as NADPH:ferrihemoprotein oxidoreductase, NADPH:hemoprotein oxidoreductase, NADPH:P450 oxidoreductase, P450 reductase, POR, CPR, CYPOR, is a membrane-bound enzyme required for electron transfer to cytochrome P450 in the microsome of the eukaryotic cell from a FAD- and FMN-containing enzyme NADPH:cytochrome P450 reductase


title: Drug metabolism

text: During reduction reactions, a chemical can enter "futile cycling", in which it gains a free-radical electron, then promptly loses it to oxygen (to form a superoxide anion).


title: Drug metabolism

text: In subsequent phase II reactions, these activated xenobiotic metabolites are conjugated with charged species such as glutathione (GSH), sulfate, glycine, or glucuronic acid. Sites on drugs where conjugation reactions occur include carboxy (-COOH), hydroxy (-OH), amino (NH), and thiol (-SH) groups. Products of conjugation reactions have increased molecular weight and tend to be less active than their substrates, unlike Phase I reactions which often produce active metabolites. The addition of large anionic groups (such as GSH) detoxifies reactive electrophiles and produces more polar metabolites that cannot diffuse across membranes, and may, therefore, be actively transported.


title: Drug metabolism

text: These reactions are catalysed by a large group of broad-specificity transferases, which in combination can metabolise almost any hydrophobic compound that contains nucleophilic or electrophilic groups. One of the most important classes of this group is that of the glutathione S-transferases (GSTs).


title: Drug metabolism

text: After phase II reactions, the xenobiotic conjugates may be further metabolized. A common example is the processing of glutathione conjugates to acetylcysteine (mercapturic acid) conjugates. Here, the γ-glutamate and glycine residues in the glutathione molecule are removed by Gamma-glutamyl transpeptidase and dipeptidases. In the final step, the cysteine residue in the conjugate is acetylated.


title: Drug metabolism

text: Conjugates and their metabolites can be excreted from cells in phase III of their metabolism, with the anionic groups acting as affinity tags for a variety of membrane transporters of the multidrug resistance protein (MRP) family. These proteins are members of the family of ATP-binding cassette transporters and can catalyse the ATP-dependent transport of a huge variety of hydrophobic anions, and thus act to remove phase II products to the extracellular medium, where they may be further metabolized or excreted.


title: Drug metabolism

text: The detoxification of endogenous reactive metabolites such as peroxides and reactive aldehydes often cannot be achieved by the system described above. This is the result of these species' being derived from normal cellular constituents and usually sharing their polar characteristics. However, since these compounds are few in number, it is possible for enzymatic systems to utilize specific molecular recognition to recognize and remove them. The similarity of these molecules to useful metabolites therefore means that different detoxification enzymes are usually required for the metabolism of each group of endogenous toxins. Examples of these specific detoxification systems are the glyoxalase system, which acts to dispose of the reactive aldehyde methylglyoxal, and the various antioxidant systems that remove reactive oxygen species.


title: Drug metabolism

text: Quantitatively, the smooth endoplasmic reticulum of the liver cell is the principal organ of drug metabolism, although every biological tissue has some ability to metabolize drugs.


title: Drug metabolism

text: Factors responsible for the liver's contribution to drug metabolism include that it is a large organ, that it is the first organ perfused by chemicals absorbed in the gut, and that there are very high concentrations of most drug-metabolizing enzyme systems relative to other organs.


title: Drug metabolism

text: If a drug is taken into the GI tract, where it enters hepatic circulation through the portal vein, it becomes well-metabolized and is said to show the "first pass effect".


title: Drug metabolism

text: Other sites of drug metabolism include epithelial cells of the gastrointestinal tract, lungs, kidneys, and the skin.


title: Drug metabolism

text: The duration and intensity of pharmacological action of most lipophilic drugs are determined by the rate they are metabolized to inactive products.


title: Drug metabolism

text: In general, anything that "increases" the rate of metabolism ("e.g.", enzyme induction) of a pharmacologically active metabolite will "decrease" the duration and intensity of the drug action.


title: Drug metabolism

text: The opposite is also true ("e.g.", enzyme inhibition). However, in cases where an enzyme is responsible for metabolizing a pro-drug into a drug, enzyme induction can speed up this conversion and increase drug levels, potentially causing toxicity.


title: Drug metabolism

text: Physiological factors that can influence drug metabolism include age, individual variation ("e.g.", pharmacogenetics), enterohepatic circulation, nutrition, intestinal flora, or sex differences.