Answer: continuous functions

Context: Some topological spaces may be endowed with a group law. In order for the group law and the topology to interweave well, the group operations must be continuous functions, that is, g • h, and g−1 must not vary wildly if g and h vary only little. Such groups are called topological groups, and they are the group objects in the category of topological spaces. The most basic examples are the reals R under addition, (R ∖ {0}, ·), and similarly with any other topological field such as the complex numbers or p-adic numbers. All of these groups are locally compact, so they have Haar measures and can be studied via harmonic analysis. The former offer an abstract formalism of invariant integrals. Invariance means, in the case of real numbers for example:

Question: What group operations must occur for group law and topology to integrate well?


Answer: reals R under addition, (R ∖ {0}, ·),

Question: What is the most simple example of topological groups?


Answer: Haar measures

Question: What variables do locally compact groups share that can be studied by harmonic analysis?


Answer: adele rings and adelic algebraic groups

Context: for any constant c. Matrix groups over these fields fall under this regime, as do adele rings and adelic algebraic groups, which are basic to number theory. Galois groups of infinite field extensions such as the absolute Galois group can also be equipped with a topology, the so-called Krull topology, which in turn is central to generalize the above sketched connection of fields and groups to infinite field extensions. An advanced generalization of this idea, adapted to the needs of algebraic geometry, is the étale fundamental group.

Question: What concepts are fundamental to number theory?


Answer: the absolute Galois group

Question: What group uses infinite field extensions with topology?


Answer: Krull topology

Question: What is used to generalize the connection of fields and groups to infinite field extensions?


Answer: the étale fundamental group

Question: What group is an advanced observation of infinite field extensions and groups that is adapted for the needs of algebraic geometry?


Answer: Lie groups

Context: Lie groups are of fundamental importance in modern physics: Noether's theorem links continuous symmetries to conserved quantities. Rotation, as well as translations in space and time are basic symmetries of the laws of mechanics. They can, for instance, be used to construct simple models—imposing, say, axial symmetry on a situation will typically lead to significant simplification in the equations one needs to solve to provide a physical description.v[›] Another example are the Lorentz transformations, which relate measurements of time and velocity of two observers in motion relative to each other. They can be deduced in a purely group-theoretical way, by expressing the transformations as a rotational symmetry of Minkowski space. The latter serves—in the absence of significant gravitation—as a model of space time in special relativity. The full symmetry group of Minkowski space, i.e. including translations, is known as the Poincaré group. By the above, it plays a pivotal role in special relativity and, by implication, for quantum field theories. Symmetries that vary with location are central to the modern description of physical interactions with the help of gauge theory.

Question: What concept is of basic importance in modern physics?


Answer: Noether's theorem

Question: What connects continuous symmetries to conserved quantities?


Answer: Rotation

Question: What term describes the basic symmetries of the laws of mechanics?


Answer: Lorentz transformations

Question: What concept relates measurements of time and velocity of two observers in motion relative to each other?


Answer: Poincaré group

Question: What describe the complete symmetry group of Minkowski space including translations?


Answer: monoid

Context: In abstract algebra, more general structures are defined by relaxing some of the axioms defining a group. For example, if the requirement that every element has an inverse is eliminated, the resulting algebraic structure is called a monoid. The natural numbers N (including 0) under addition form a monoid, as do the nonzero integers under multiplication (Z ∖ {0}, ·), see above. There is a general method to formally add inverses to elements to any (abelian) monoid, much the same way as (Q ∖ {0}, ·) is derived from (Z ∖ {0}, ·), known as the Grothendieck group. Groupoids are similar to groups except that the composition a • b need not be defined for all a and b. They arise in the study of more complicated forms of symmetry, often in topological and analytical structures, such as the fundamental groupoid or stacks. Finally, it is possible to generalize any of these concepts by replacing the binary operation with an arbitrary n-ary one (i.e. an operation taking n arguments). With the proper generalization of the group axioms this gives rise to an n-ary group. The table gives a list of several structures generalizing groups.

Question: What product is created if the requirement that every element has an inverse is eliminated?


Answer: natural numbers N (including 0)

Question: What type of numbers under addition form a monoid?


Answer: the Grothendieck group

Question: What method formally adds inverses to elements to any monoid?


Answer: the binary operation

Question: What can be replaced to simplify abstract algebra concepts?


Answer: Central Africa

Context: The Central African Republic (CAR; Sango: Ködörösêse tî Bêafrîka; French: République centrafricaine pronounced: [ʁepyblik sɑ̃tʁafʁikɛn], or Centrafrique [sɑ̃tʀafʁik]) is a landlocked country in Central Africa. It is bordered by Chad to the north, Sudan to the northeast, South Sudan to the east, the Democratic Republic of the Congo and the Republic of the Congo to the south and Cameroon to the west. The CAR covers a land area of about 620,000 square kilometres (240,000 sq mi) and had an estimated population of around 4.7 million as of 2014[update].

Question: Where is the Central African Republic located?


Answer: Chad

Question: What country borders CAR in the North?


Answer: the Republic of the Congo

Question: What Country borders CAR in the South?


Answer: Cameroon

Question: What Country borders CAR in the West?


Answer: 4.7 million

Question: What is the population of CAR approximately?


Answer: France

Context: What is today the Central African Republic has been inhabited for millennia; however, the country's current borders were established by France, which ruled the country as a colony starting in the late 19th century. After gaining independence from France in 1960, the Central African Republic was ruled by a series of autocratic leaders; by the 1990s, calls for democracy led to the first multi-party democratic elections in 1993. Ange-Félix Patassé became president, but was later removed by General François Bozizé in the 2003 coup. The Central African Republic Bush War began in 2004 and, despite a peace treaty in 2007 and another in 2011, fighting broke out between various factions in December 2012, leading to ethnic and religious cleansing of the Muslim minority and massive population displacement in 2013 and 2014.

Question: Who established CAR's borders?


Answer: France

Question: What country ruled CAR as a colony?


Answer: in 1960

Question: When did CAR become independent?


Answer: Ange-Félix Patassé

Question: Who was the first democratically elected President?


Answer: Muslim minority

Question: What religion is a minority in CAR?


Answer: Approximately 10,000 years ago

Context: Approximately 10,000 years ago, desertification forced hunter-gatherer societies south into the Sahel regions of northern Central Africa, where some groups settled and began farming as part of the Neolithic Revolution. Initial farming of white yam progressed into millet and sorghum, and before 3000 BC the domestication of African oil palm improved the groups' nutrition and allowed for expansion of the local populations. Bananas arrived in the region and added an important source of carbohydrates to the diet; they were also used in the production of alcoholic beverages.[when?] This Agricultural Revolution, combined with a "Fish-stew Revolution", in which fishing began to take place, and the use of boats, allowed for the transportation of goods. Products were often moved in ceramic pots, which are the first known examples of artistic expression from the region's inhabitants.

Question: How long ago did people start living in the area?


Answer: farming

Question: What agricultural job did people settling in the area perform?


Answer: African oil palm

Question: What vegetation helped populations expand?


Answer: Bananas

Question: What was an imported food that provided most of the carbohydrates?


Answer: Fish

Question: What important protein helped with expansion of the inhabitants?


Answer: 16th and 17th centuries

Context: During the 16th and 17th centuries slave traders began to raid the region as part of the expansion of the Saharan and Nile River slave routes. Their captives were slaved and shipped to the Mediterranean coast, Europe, Arabia, the Western Hemisphere, or to the slave ports and factories along the West and North Africa or South the Ubanqui and Congo rivers. In the mid 19th century, the Bobangi people became major slave traders and sold their captives to the Americas using the Ubangi river to reach the coast. During the 18th century Bandia-Nzakara peoples established the Bangassou Kingdom along the Ubangi River.

Question: When did the slave trade hit the CAR region?


Answer: Europe

Question: What is one area where captive slaves were sent?


Answer: Bobangi people

Question: Which people were major slave traders in the 19th century?


Answer: the Americas

Question: Who did the Bobangi sell slave to?


Answer: Ubangi River

Question: What river saw the establishment of a new Kingdom?


Answer: 1920

Context: In 1920 French Equatorial Africa was established and Ubangi-Shari was administered from Brazzaville. During the 1920s and 1930s the French introduced a policy of mandatory cotton cultivation, a network of roads was built, attempts were made to combat sleeping sickness and Protestant missions were established to spread Christianity. New forms of forced labor were also introduced and a large number of Ubangians were sent to work on the Congo-Ocean Railway. Many of these forced laborers died of exhaustion, illness, or the poor conditions which claimed between 20% and 25% of the 127,000 workers.

Question: When was Equatorial Africa established?


Answer: Brazzaville

Question: Where was Equatorial African ran from?


Answer: cotton

Question: What plant was mandated to be grown by the French?


Answer: a network of roads

Question: What important infrastructure was built in the 1920s.


Answer: Christianity

Question: What religion was spread through CAR?


Answer: Second World War

Context: In September 1940, during the Second World War, pro-Gaullist French officers took control of Ubangi-Shari and General Leclerc established his headquarters for the Free French Forces in Bangui. In 1946 Barthélémy Boganda was elected with 9,000 votes to the French National Assembly, becoming the first representative for CAR in the French government. Boganda maintained a political stance against racism and the colonial regime but gradually became disheartened with the French political system and returned to CAR to establish the Movement for the Social Evolution of Black Africa (MESAN) in 1950.

Question: During what war did French officers setup headquarters in CAR?


Answer: Barthélémy Boganda

Question: Who was elected in 1946 as the first representative?


Answer: 9,000 votes

Question: How many votes did Boganda get?


Answer: political stance against racism

Question: What was Bogandas platform that he ran for?


Answer: disheartened with the French political system

Question: What caused Boganda to leave his elected post?


Answer: 347,000 out of the total 356,000 votes

Context: In the Ubangi-Shari Territorial Assembly election in 1957, MESAN captured 347,000 out of the total 356,000 votes, and won every legislative seat, which led to Boganda being elected president of the Grand Council of French Equatorial Africa and vice-president of the Ubangi-Shari Government Council. Within a year, he declared the establishment of the Central African Republic and served as the country's first prime minister. MESAN continued to exist, but its role was limited. After Boganda's death in a plane crash on 29 March 1959, his cousin, David Dacko, took control of MESAN and became the country's first president after the CAR had formally received independence from France. Dacko threw out his political rivals, including former Prime Minister and Mouvement d'évolution démocratique de l'Afrique centrale (MEDAC), leader Abel Goumba, whom he forced into exile in France. With all opposition parties suppressed by November 1962, Dacko declared MESAN as the official party of the state.

Question: What was the overwhelming amount of votes MESAN captured?


Answer: every legislative seat

Question: How many seats did MESAN win?


Answer: Boganda

Question: Who was elected president of the Grand Council?


Answer: a plane crash

Question: How did Boganda die?


Answer: his cousin, David Dacko

Question: Who took over after Boganda died?


Answer: young students protested against Bokassa's decree

Context: In April 1979, young students protested against Bokassa's decree that all school attendees would need to buy uniforms from a company owned by one of his wives. The government violently suppressed the protests, killing 100 children and teenagers. Bokassa himself may have been personally involved in some of the killings. In September 1979, France overthrew Bokassa and "restored" Dacko to power (subsequently restoring the name of the country to the Central African Republic). Dacko, in turn, was again overthrown in a coup by General André Kolingba on 1 September 1981.

Question: What caused a violent uprising?


Answer: 100 children and teenagers

Question: How many were killed in the April 1979 protests?


Answer: France

Question: Who overthrew Bokassa after this incident?


Answer: Dacko

Question: Who did France restore into power?


Answer: General André Kolingba

Question: Who eventually overthrew Dacko?


Answer: a pro-democracy movement

Context: By 1990, inspired by the fall of the Berlin Wall, a pro-democracy movement arose. Pressure from the United States, France, and from a group of locally represented countries and agencies called GIBAFOR (France, the USA, Germany, Japan, the EU, the World Bank, and the UN) finally led Kolingba to agree, in principle, to hold free elections in October 1992 with help from the UN Office of Electoral Affairs. After using the excuse of alleged irregularities to suspend the results of the elections as a pretext for holding on to power, President Kolingba came under intense pressure from GIBAFOR to establish a "Conseil National Politique Provisoire de la République" (Provisional National Political Council, CNPPR) and to set up a "Mixed Electoral Commission", which included representatives from all political parties.[citation needed]

Question: What was inspired by the fall of the Berlin wall?


Answer: the United States

Question: What large country pressured CAR to hold elections?


Answer: October 1992

Question: When were free elections held?


Answer: UN Office of Electoral Affairs

Question: Who helped with the Free Elections?


Answer: alleged irregularities

Question: What excuse did Kolingba use to deny the election results?


Answer: in 1993

Context: When a second round of elections were finally held in 1993, again with the help of the international community coordinated by GIBAFOR, Ange-Félix Patassé won in the second round of voting with 53% of the vote while Goumba won 45.6%. Patassé's party, the Mouvement pour la Libération du Peuple Centrafricain (MLPC) or Movement for the Liberation of the Central African People, gained a simple but not an absolute majority of seats in parliament, which meant Patassé's party required coalition partners.[citation needed]

Question: When was a second democratic election held?


Answer: Ange-Félix Patassé

Question: Who became the first democratically elected president?


Answer: 53% of the vote

Question: What percentage did Patasse win with?


Answer: Mouvement pour la Libération du Peuple Centrafricain

Question: What was the winning party?


Answer: gained a simple but not an absolute majority

Question: Did Patasse get a majority of the votes?


Answer: 28 December 1994

Context: Patassé purged many of the Kolingba elements from the government and Kolingba supporters accused Patassé's government of conducting a "witch hunt" against the Yakoma. A new constitution was approved on 28 December 1994 but had little impact on the country's politics. In 1996–1997, reflecting steadily decreasing public confidence in the government's erratic behaviour, three mutinies against Patassé's administration were accompanied by widespread destruction of property and heightened ethnic tension. During this time (1996) the Peace Corps evacuated all its volunteers to neighboring Cameroon. To date, the Peace Corps has not returned to the Central African Republic. The Bangui Agreements, signed in January 1997, provided for the deployment of an inter-African military mission, to Central African Republic and re-entry of ex-mutineers into the government on 7 April 1997. The inter-African military mission was later replaced by a U.N. peacekeeping force (MINURCA).

Question: When was the new constitution for CAR approved?


Answer: In 1996–1997

Question: When did a mutiny form against Patasse?


Answer: widespread destruction of property

Question: The mutinies caused what effects on the country?


Answer: The Bangui Agreements

Question: What agreement gave the authority for deployment of military intervention?


Answer: Cameroon

Question: Where did the peace corps evacuate to?


Answer: murder of many political opponents

Context: In the aftermath of the failed coup, militias loyal to Patassé sought revenge against rebels in many neighborhoods of Bangui and incited unrest including the murder of many political opponents. Eventually, Patassé came to suspect that General François Bozizé was involved in another coup attempt against him, which led Bozizé to flee with loyal troops to Chad. In March 2003, Bozizé launched a surprise attack against Patassé, who was out of the country. Libyan troops and some 1,000 soldiers of Bemba's Congolese rebel organization failed to stop the rebels and Bozizé's forces succeeded in overthrowing Patassé.[citation needed]

Question: The failed coup caused what effects?


Answer: General François Bozizé

Question: Which General was involved in another coup?


Answer: Chad

Question: Where did General Bozize flee to escape?


Answer: March 2003

Question: When did Bozize finally attempt his coup?


Answer: Bozizé's forces

Question: Who succeeded in finally overthrowing Patasse?


Answer: Bush War

Context: In 2004 the Central African Republic Bush War began as forces opposed to Bozizé took up arms against his government. In May 2005 Bozizé won a presidential election that excluded Patassé and in 2006 fighting continued between the government and the rebels. In November 2006, Bozizé's government requested French military support to help them repel rebels who had taken control of towns in the country's northern regions. Though the initially public details of the agreement pertained to logistics and intelligence, the French assistance eventually included strikes by Mirage jets against rebel positions.

Question: What war started in 2004?


Answer: Bozizé won a presidential election

Question: In what way did Bozize made his rule legitimate?


Answer: November 2006

Question: When did CAR ask for assistance from the French against rebels?


Answer: strikes by Mirage jets

Question: How did the French assist against the rebels?


Answer: towns in the country's northern regions

Question: What did the rebels take over?


Answer: Syrte Agreement

Context: The Syrte Agreement in February and the Birao Peace Agreement in April 2007 called for a cessation of hostilities, the billeting of FDPC fighters and their integration with FACA, the liberation of political prisoners, integration of FDPC into government, an amnesty for the UFDR, its recognition as a political party, and the integration of its fighters into the national army. Several groups continued to fight but other groups signed on to the agreement, or similar agreements with the government (e.g. UFR on 15 December 2008). The only major group not to sign an agreement at the time was the CPJP, which continued its activities and signed a peace agreement with the government on 25 August 2012.

Question: What agreement called for the stop of Hostilities?


Answer: the liberation of political prisoners

Question: What did the Birao Peace Agreement call for?


Answer: CPJP

Question: What major group did not sign the peace agreement immediately?


Answer: 25 August 2012

Question: When did the CPJP finally sign the peace agreement?


Answer: April 2007

Question: When was the Birao Peace Agreement signed?


Answer: Michel Djotodia

Context: Michel Djotodia took over as president and in May 2013 Central African Republic's Prime Minister Nicolas Tiangaye requested a UN peacekeeping force from the UN Security Council and on 31 May former President Bozizé was indicted for crimes against humanity and incitement of genocide. The security situation did not improve during June–August 2013 and there were reports of over 200,000 internally displaced persons (IDPs) as well as human rights abuses and renewed fighting between Séléka and Bozizé supporters.

Question: Who became president in 2013?


Answer: crimes against humanity

Question: What was Bozize indicted for?


Answer: genocide

Question: What mass murder did Bozize commit?


Answer: 200,000

Question: How many people were displaced in the unrests?


Answer: Séléka

Question: What faction was fighting against the remaining Bozize loyalists?


Answer: Dzanga-Sangha National Park

Context: In the southwest, the Dzanga-Sangha National Park is located in a rain forest area. The country is noted for its population of forest elephants and western lowland gorillas. In the north, the Manovo-Gounda St Floris National Park is well-populated with wildlife, including leopards, lions, cheetahs and rhinos, and the Bamingui-Bangoran National Park is located in the northeast of CAR. The parks have been seriously affected by the activities of poachers, particularly those from Sudan, over the past two decades.[citation needed]

Question: What national part is located in the South West?


Answer: forest elephants

Question: What large animals reside in the national park?


Answer: lowland gorillas

Question: Which Primate can be found in the national park?


Answer: Manovo-Gounda St Floris

Question: What National Park can be found in the North?


Answer: the activities of poachers

Question: What has threatened the wildlife in this park?


Answer: missionary groups

Context: There are many missionary groups operating in the country, including Lutherans, Baptists, Catholics, Grace Brethren, and Jehovah's Witnesses. While these missionaries are predominantly from the United States, France, Italy, and Spain, many are also from Nigeria, the Democratic Republic of the Congo, and other African countries. Large numbers of missionaries left the country when fighting broke out between rebel and government forces in 2002–3, but many of them have now returned to continue their work.

Question: What religious groups operate in CAR?


Answer: United States

Question: Where do most of the missionaries come from?


Answer: when fighting broke out between rebel and government forces

Question: What caused most of the missionaries to leave the country?


Answer: Democratic Republic of the Congo

Question: What African country bordering CAR are some of these missionaries from?


Answer: 2002–3

Question: When did fighting break out in CAR?


Answer: risk of starvation

Context: In 2006, due to ongoing violence, over 50,000 people in the country's northwest were at risk of starvation but this was averted due to assistance from the United Nations.[citation needed] On 8 January 2008, the UN Secretary-General Ban Ki-Moon declared that the Central African Republic was eligible to receive assistance from the Peacebuilding Fund. Three priority areas were identified: first, the reform of the security sector; second, the promotion of good governance and the rule of law; and third, the revitalization of communities affected by conflicts. On 12 June 2008, the Central African Republic requested assistance from the UN Peacebuilding Commission, which was set up in 2005 to help countries emerging from conflict avoid devolving back into war or chaos.

Question: Due to fighting, what threatened people in the NorthWest?


Answer: United Nations

Question: Who assisted in saving the people from starvation?


Answer: Secretary-General Ban Ki-Moon

Question: Who headed the UN effort to rebuild CAR?


Answer: 12 June 2008

Question: When did CAR request assistance directly to prevent war?


Answer: UN Peacebuilding Commission

Question: Who assisted CAR in avoiding war?


Answer: 31 March 2013

Context: A new government was appointed on 31 March 2013, which consisted of members of Séléka and representatives of the opposition to Bozizé, one pro-Bozizé individual, and a number representatives of civil society. On 1 April, the former opposition parties declared that they would boycott the government. After African leaders in Chad refused to recognize Djotodia as President, proposing to form a transitional council and the holding of new elections, Djotodia signed a decree on 6 April for the formation of a council that would act as a transitional parliament. The council was tasked with electing a president to serve prior to elections in 18 months.

Question: When was the new Government seated in CAR?


Answer: boycott the government

Question: What did the former opposition parties declare?


Answer: Djotodia

Question: Who was refused as new president?


Answer: a transitional parliament

Question: Who would rule the country temporarily?


Answer: 18 months

Question: How long did the parliament have until the next election?


Answer: $400 a year

Context: The per capita income of the Republic is often listed as being approximately $400 a year, one of the lowest in the world, but this figure is based mostly on reported sales of exports and largely ignores the unregistered sale of foods, locally produced alcoholic beverages, diamonds, ivory, bushmeat, and traditional medicine. For most Central Africans, the informal economy of the CAR is more important than the formal economy.[citation needed] Export trade is hindered by poor economic development and the country's landlocked position.[citation needed]

Question: What is the per capita income in CAR?


Answer: one of the lowest

Question: How is the per capita income compared to the world?


Answer: diamonds

Question: What gemstone comes from the CAR?


Answer: ivory

Question: Which item that poachers kill elephants for can be obtained in CAR?


Answer: country's landlocked position

Question: What hinders export?


Answer: food crops

Context: Agriculture is dominated by the cultivation and sale of food crops such as cassava, peanuts, maize, sorghum, millet, sesame, and plantain. The annual real GDP growth rate is just above 3%. The importance of food crops over exported cash crops is indicated by the fact that the total production of cassava, the staple food of most Central Africans, ranges between 200,000 and 300,000 tonnes a year, while the production of cotton, the principal exported cash crop, ranges from 25,000 to 45,000 tonnes a year. Food crops are not exported in large quantities, but still constitute the principal cash crops of the country, because Central Africans derive far more income from the periodic sale of surplus food crops than from exported cash crops such as cotton or coffee.[citation needed] Much of the country is self-sufficient in food crops; however, livestock development is hindered by the presence of the tsetse fly.[citation needed]

Question: What type of agriculture is popular in the CAR?


Answer: 3%

Question: The economy grows at what rate in the last few years?


Answer: 200,000 and 300,000

Question: How many tonnes of Cassave is produced per year?


Answer: cotton

Question: What product is produced that is exported?


Answer: tsetse fly

Question: Which insect hinders livestock development?


Answer: Socatel

Context: Presently, the Central African Republic has active television services, radio stations, internet service providers, and mobile phone carriers; Socatel is the leading provider for both internet and mobile phone access throughout the country. The primary governmental regulating bodies of telecommunications are the Ministère des Postes and Télécommunications et des Nouvelles Technologies. In addition, the Central African Republic receives international support on telecommunication related operations from ITU Telecommunication Development Sector (ITU-D) within the International Telecommunication Union to improve infrastructure.

Question: What is the major telecommunications provider in CAR?


Answer: Ministère des Postes and Télécommunications et des Nouvelles Technologies

Question: Which body regulated communications?


Answer: internet service

Question: What type of access is available?


Answer: ITU Telecommunication Development Sector

Question: Who assists CAR with telecommunications?


Answer: improve infrastructure

Question: What does the CAR get help with with regards to communication from ITU-D?


Answer: poor

Context: The 2009 Human Rights Report by the United States Department of State noted that human rights in CAR were poor and expressed concerns over numerous government abuses. The U.S. State Department alleged that major human rights abuses such as extrajudicial executions by security forces, torture, beatings and rape of suspects and prisoners occurred with impunity. It also alleged harsh and life-threatening conditions in prisons and detention centers, arbitrary arrest, prolonged pretrial detention and denial of a fair trial, restrictions on freedom of movement, official corruption, and restrictions on workers' rights.

Question: How are the human rights in the CAR?


Answer: government abuses

Question: What concerns are there regarding to human rights?


Answer: extrajudicial executions

Question: What punishment is a human rights violation per the US state Dept?


Answer: harsh and life-threatening conditions

Question: How is the prison quality in the CAR?


Answer: arbitrary arrest, prolonged pretrial detention and denial of a fair trial

Question: What right in a court is denied and considered a human right violation?


Answer: genetic and environmental factors

Context: Asthma is thought to be caused by a combination of genetic and environmental factors. Environmental factors include exposure to air pollution and allergens. Other potential triggers include medications such as aspirin and beta blockers. Diagnosis is usually based on the pattern of symptoms, response to therapy over time, and spirometry. Asthma is classified according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate. It may also be classified as atopic or non-atopic where atopy refers to a predisposition toward developing a type 1 hypersensitivity reaction.

Question: What two factors cause asthma?


Answer: exposure to air pollution and allergens

Question: What are two enviromental factors?


Answer: aspirin and beta blockers

Question: What medications can also trigger asthma?


Answer: the pattern of symptoms, response to therapy over time, and spirometry

Question: What patterns are used to diagnose asthma?


Answer: according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate

Question: How is asthma classified?


Answer: There is no cure for asthma

Context: There is no cure for asthma. Symptoms can be prevented by avoiding triggers, such as allergens and irritants, and by the use of inhaled corticosteroids. Long-acting beta agonists (LABA) or antileukotriene agents may be used in addition to inhaled corticosteroids if asthma symptoms remain uncontrolled. Treatment of rapidly worsening symptoms is usually with an inhaled short-acting beta-2 agonist such as salbutamol and corticosteroids taken by mouth. In very severe cases, intravenous corticosteroids, magnesium sulfate, and hospitalization may be required.

Question: Is there a cure for asthma?


Answer: by avoiding triggers, such as allergens and irritants, and by the use of inhaled corticosteroids

Question: How can symptoms be prevented?


Answer: an inhaled short-acting beta-2 agonist such as salbutamol and corticosteroids

Question: What is taken by mouth to treat rapidly worsening symptoms?


Answer: intravenous corticosteroids, magnesium sulfate, and hospitalization may be required

Question: What happens in very severe cases of asthma?


Answer: recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing

Context: Asthma is characterized by recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing. Sputum may be produced from the lung by coughing but is often hard to bring up. During recovery from an attack, it may appear pus-like due to high levels of white blood cells called eosinophils. Symptoms are usually worse at night and in the early morning or in response to exercise or cold air. Some people with asthma rarely experience symptoms, usually in response to triggers, whereas others may have marked and persistent symptoms.

Question: What are the characteristics of asthma?


Answer: at night and in the early morning or in response to exercise or cold air

Question: When are symptoms of asthma normally worse?


Answer: Sputum

Question: What is produced in the lungs by coughing?


Answer: worse at night

Question: Is asthma worst during the day or at night time?


Answer: Some people with asthma rarely experience symptoms, u

Question: Does everyone have horrible episodes of asthma?


Answer: more frequently

Context: A number of other health conditions occur more frequently in those with asthma, including gastro-esophageal reflux disease (GERD), rhinosinusitis, and obstructive sleep apnea. Psychological disorders are also more common, with anxiety disorders occurring in between 16–52% and mood disorders in 14–41%. However, it is not known if asthma causes psychological problems or if psychological problems lead to asthma. Those with asthma, especially if it is poorly controlled, are at high risk for radiocontrast reactions.

Question: Do other health concerns happen less frequently or more frequently with asthma?


Answer: gastro-esophageal reflux disease (GERD), rhinosinusitis, and obstructive sleep apnea

Question: What are three of the other health conditions that occur more frequently with asthma?


Answer: Psychological disorders

Question: What other type of disorders are frequent in asthma sufferers?


Answer: radiocontrast reactions

Question: What are those with asthma that is poorly controll more susceptable to?


Answer: allergens, air pollution, and other environmental chemicals

Context: Many environmental factors have been associated with asthma's development and exacerbation including allergens, air pollution, and other environmental chemicals. Smoking during pregnancy and after delivery is associated with a greater risk of asthma-like symptoms. Low air quality from factors such as traffic pollution or high ozone levels, has been associated with both asthma development and increased asthma severity. Exposure to indoor volatile organic compounds may be a trigger for asthma; formaldehyde exposure, for example, has a positive association. Also, phthalates in certain types of PVC are associated with asthma in children and adults.

Question: What are some of the enviromental factors that have been linked to asthma?


Answer: Smoking during pregnancy and after delivery

Question: What two things are associated with a greater risk of asthma-like symptoms?


Answer: Low air quality from factors such as traffic pollution or high ozone levels

Question: What can cause symptoms and asthma serverity to change?


Answer: indoor volatile organic compounds

Question: Exposure to what compounds can also trigger asthma?


Answer: The hygiene hypothesis

Context: The hygiene hypothesis attempts to explain the increased rates of asthma worldwide as a direct and unintended result of reduced exposure, during childhood, to non-pathogenic bacteria and viruses. It has been proposed that the reduced exposure to bacteria and viruses is due, in part, to increased cleanliness and decreased family size in modern societies. Exposure to bacterial endotoxin in early childhood may prevent the development of asthma, but exposure at an older age may provoke bronchoconstriction. Evidence supporting the hygiene hypothesis includes lower rates of asthma on farms and in households with pets.

Question: What hypothesis tries to explain the increased amount of asthma world wide?


Answer: a direct and unintended result of reduced exposure, during childhood, to non-pathogenic bacteria and viruses

Question: How does the hygiene hypothesis explain the increase in asthma?


Answer: increased cleanliness and decreased family size in modern societies

Question: What has caused the reduced exposure in childhood?


Answer: Exposure to bacterial endotoxin in early childhood

Question: What could prevent asthma?


Answer: lower rates of asthma on farms and in households with pets.

Question: What is some of the evidence backing the hygiene hypothesis?


Answer: Family history

Context: Family history is a risk factor for asthma, with many different genes being implicated. If one identical twin is affected, the probability of the other having the disease is approximately 25%. By the end of 2005, 25 genes had been associated with asthma in six or more separate populations, including GSTM1, IL10, CTLA-4, SPINK5, LTC4S, IL4R and ADAM33, among others. Many of these genes are related to the immune system or modulating inflammation. Even among this list of genes supported by highly replicated studies, results have not been consistent among all populations tested. In 2006 over 100 genes were associated with asthma in one genetic association study alone; more continue to be found.

Question: What else is a risk factor for asthma?


Answer: approximately 25%

Question: If one identical twin has asthma, what are the odds of the other twin having asthma?


Answer: 25 genes

Question: How many genes were associated with asthma by the end of 2005?


Answer: over 100 genes

Question: How many genes were associated with asthma in 2006?


Answer: the immune system or modulating inflammation

Question: What else are these genes closely related to?


Answer: chronic inflammation of the conducting zone of the airways

Context: Asthma is the result of chronic inflammation of the conducting zone of the airways (most especially the bronchi and bronchioles), which subsequently results in increased contractability of the surrounding smooth muscles. This among other factors leads to bouts of narrowing of the airway and the classic symptoms of wheezing. The narrowing is typically reversible with or without treatment. Occasionally the airways themselves change. Typical changes in the airways include an increase in eosinophils and thickening of the lamina reticularis. Chronically the airways' smooth muscle may increase in size along with an increase in the numbers of mucous glands. Other cell types involved include: T lymphocytes, macrophages, and neutrophils. There may also be involvement of other components of the immune system including: cytokines, chemokines, histamine, and leukotrienes among others.

Question: What is asthma the result of?


Answer: the bronchi and bronchioles

Question: What two airways are most effected by asthma?


Answer: an increase in eosinophils and thickening of the lamina reticularis

Question: In what ways do airways change?


Answer: T lymphocytes, macrophages, and neutrophils

Question: What other cell types are involced with the changing of airways?


Answer: cytokines, chemokines, histamine, and leukotrienes among others

Question: What other components of the immune systems are included?


Answer: there is not one universal agreed upon definition

Context: While asthma is a well recognized condition, there is not one universal agreed upon definition. It is defined by the Global Initiative for Asthma as "a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role. The chronic inflammation is associated with airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and coughing particularly at night or in the early morning. These episodes are usually associated with widespread but variable airflow obstruction within the lung that is often reversible either spontaneously or with treatment".

Question: Is there a universal definition of astham?


Answer: many cells and cellular elements play a role

Question: What main components play a role in asthma?


Answer: airway hyper-responsiveness

Question: What is the inflamation a result of?


Answer: episodes of wheezing, breathlessness, chest tightness and coughing

Question: What does hyper-responsiveness of the airways cause?


Answer: spontaneously or with treatment

Question: What are two ways to reverse an asthma attack?


Answer: There is currently no precise test

Context: There is currently no precise test with the diagnosis typically based on the pattern of symptoms and response to therapy over time. A diagnosis of asthma should be suspected if there is a history of: recurrent wheezing, coughing or difficulty breathing and these symptoms occur or worsen due to exercise, viral infections, allergens or air pollution. Spirometry is then used to confirm the diagnosis. In children under the age of six the diagnosis is more difficult as they are too young for spirometry.

Question: Is there a test to determine asthma in an individual?


Answer: pattern of symptoms and response to therapy over time

Question: What is diagnosis based on typically?


Answer: if there is a history of: recurrent wheezing, coughing or difficulty breathing

Question: When should you suspect asthma?


Answer: Spirometry

Question: What is used to confirm the diagnosis of asthma?


Answer: children under the age of six

Question: What age is too young to use spirometry to determine asthma?


Answer: Spirometry

Context: Spirometry is recommended to aid in diagnosis and management. It is the single best test for asthma. If the FEV1 measured by this technique improves more than 12% following administration of a bronchodilator such as salbutamol, this is supportive of the diagnosis. It however may be normal in those with a history of mild asthma, not currently acting up. As caffeine is a bronchodilator in people with asthma, the use of caffeine before a lung function test may interfere with the results. Single-breath diffusing capacity can help differentiate asthma from COPD. It is reasonable to perform spirometry every one or two years to follow how well a person's asthma is controlled.

Question: What is recommended to help in the diagnosis of asthma?


Answer: It is the single best test for asthma

Question: Why is spirometry so commonly used to diagnose asthma?


Answer: If the FEV1 measured by this technique improves more than 12% following administration of a bronchodilator

Question: What helps support the evidence of asthma?


Answer: caffeine

Question: What substance can skew the results of an asthma test?


Answer: Single-breath diffusing capacity

Question: What test can tell the difference between asthma and COPD?


Answer: ≥20%

Context: Other supportive evidence includes: a ≥20% difference in peak expiratory flow rate on at least three days in a week for at least two weeks, a ≥20% improvement of peak flow following treatment with either salbutamol, inhaled corticosteroids or prednisone, or a ≥20% decrease in peak flow following exposure to a trigger. Testing peak expiratory flow is more variable than spirometry, however, and thus not recommended for routine diagnosis. It may be useful for daily self-monitoring in those with moderate to severe disease and for checking the effectiveness of new medications. It may also be helpful in guiding treatment in those with acute exacerbations.

Question: What is the rate that is used in most of the evidence?


Answer: . Testing peak expiratory flow

Question: What is more variable than spirometry but not recommended?


Answer: according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate

Context: Asthma is clinically classified according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate. Asthma may also be classified as atopic (extrinsic) or non-atopic (intrinsic), based on whether symptoms are precipitated by allergens (atopic) or not (non-atopic). While asthma is classified based on severity, at the moment there is no clear method for classifying different subgroups of asthma beyond this system. Finding ways to identify subgroups that respond well to different types of treatments is a current critical goal of asthma research.

Question: How is asthma clinically classified?


Answer: as atopic (extrinsic) or non-atopic (intrinsic)

Question: How else is asthma classified?


Answer: atopic

Question: When asthma is caused by allergens that is called what?


Answer: severity

Question: What is asthma usually classified based on?


Answer: Finding ways to identify subgroups that respond well to different types of treatments

Question: What is a important goal of asthma research?


Answer: a chronic obstructive condition

Context: Although asthma is a chronic obstructive condition, it is not considered as a part of chronic obstructive pulmonary disease as this term refers specifically to combinations of disease that are irreversible such as bronchiectasis, chronic bronchitis, and emphysema. Unlike these diseases, the airway obstruction in asthma is usually reversible; however, if left untreated, the chronic inflammation from asthma can lead the lungs to become irreversibly obstructed due to airway remodeling. In contrast to emphysema, asthma affects the bronchi, not the alveoli.

Question: What kind of condition is asthma?


Answer: bronchiectasis, chronic bronchitis, and emphysema

Question: What are examples of chronic obstructive pulmonary disease?


Answer: asthma is usually reversible

Question: Is the airway obstuction reversable in asthma?


Answer: alveoli

Question: What part of the airway does emphysema affect?


Answer: the bronchi

Question: What part of the airway does asthma affect?


Answer: professional athletes

Context: Exercise can trigger bronchoconstriction both in people with or without asthma. It occurs in most people with asthma and up to 20% of people without asthma. Exercise-induced bronchoconstriction is common in professional athletes. The highest rates are among cyclists (up to 45%), swimmers, and cross-country skiers. While it may occur with any weather conditions it is more common when it is dry and cold. Inhaled beta2-agonists do not appear to improve athletic performance among those without asthma however oral doses may improve endurance and strength.

Question: Exercise-induced bronchoconstriction is common in what profession?


Answer: cyclists (up to 45%), swimmers, and cross-country skiers

Question: What professions has the highest rate of Exercise-induced bronchoconstriction?


Answer: when it is dry and cold

Question: What conditions are more likely to cause Exercise-induced bronchoconstriction?


Answer: Inhaled beta2-agonists

Question: What does not appear to help athletic performance that do not have asthma?


Answer: occupational disease

Context: Asthma as a result of (or worsened by) workplace exposures, is a commonly reported occupational disease. Many cases however are not reported or recognized as such. It is estimated that 5–25% of asthma cases in adults are work–related. A few hundred different agents have been implicated with the most common being: isocyanates, grain and wood dust, colophony, soldering flux, latex, animals, and aldehydes. The employment associated with the highest risk of problems include: those who spray paint, bakers and those who process food, nurses, chemical workers, those who work with animals, welders, hairdressers and timber workers.

Question: Asthma that is the result of or made worse by workplace exposure is reported as what?


Answer: It is estimated that 5–25%

Question: What percent of asthma cases in adults are work-related?


Answer: isocyanates, grain and wood dust, colophony, soldering flux, latex, animals, and aldehydes

Question: What are some of the most common agents?


Answer: those who spray paint, bakers and those who process food, nurses, chemical workers, those who work with animals, welders, hairdressers and timber workers

Question: What professions normally have the highest risk of problems?


Answer: allergic rhinitis and sinusitis

Context: Many other conditions can cause symptoms similar to those of asthma. In children, other upper airway diseases such as allergic rhinitis and sinusitis should be considered as well as other causes of airway obstruction including: foreign body aspiration, tracheal stenosis or laryngotracheomalacia, vascular rings, enlarged lymph nodes or neck masses. Bronchiolitis and other viral infections may also produce wheezing. In adults, COPD, congestive heart failure, airway masses, as well as drug-induced coughing due to ACE inhibitors should be considered. In both populations vocal cord dysfunction may present similarly.

Question: What is a condition that can cause symptoms of astham in children?


Answer: foreign body aspiration, tracheal stenosis or laryngotracheomalacia, vascular rings, enlarged lymph nodes or neck masses

Question: What are some other causes of airway obstruction?


Answer: Bronchiolitis and other viral infections

Question: What other conditions can cause wheezing?


Answer: COPD, congestive heart failure, airway masses, as well as drug-induced coughing due to ACE inhibitors

Question: In adults, what conditions can cause the symptoms of asthma?


Answer: Chronic obstructive pulmonary disease

Context: Chronic obstructive pulmonary disease can coexist with asthma and can occur as a complication of chronic asthma. After the age of 65 most people with obstructive airway disease will have asthma and COPD. In this setting, COPD can be differentiated by increased airway neutrophils, abnormally increased wall thickness, and increased smooth muscle in the bronchi. However, this level of investigation is not performed due to COPD and asthma sharing similar principles of management: corticosteroids, long acting beta agonists, and smoking cessation. It closely resembles asthma in symptoms, is correlated with more exposure to cigarette smoke, an older age, less symptom reversibility after bronchodilator administration, and decreased likelihood of family history of atopy.

Question: What is a complication of chronic asthma?


Answer: asthma and COPD

Question: If you are 65 years old and have an obstructive airway disesase, you are more likely to have what other conditions?


Answer: by increased airway neutrophils, abnormally increased wall thickness, and increased smooth muscle in the bronchi

Question: How is COPD differentiated?


Answer: due to COPD and asthma sharing similar principles of management

Question: Why is this not determined in a patient with COPD?


Answer: corticosteroids, long acting beta agonists, and smoking cessation

Question: What are the principles of management for asthma and COPD?


Answer: The evidence for the effectiveness of measures to prevent

Context: The evidence for the effectiveness of measures to prevent the development of asthma is weak. Some show promise including: limiting smoke exposure both in utero and after delivery, breastfeeding, and increased exposure to daycare or large families but none are well supported enough to be recommended for this indication. Early pet exposure may be useful. Results from exposure to pets at other times are inconclusive and it is only recommended that pets be removed from the home if a person has allergic symptoms to said pet. Dietary restrictions during pregnancy or when breast feeding have not been found to be effective and thus are not recommended. Reducing or eliminating compounds known to sensitive people from the work place may be effective. It is not clear if annual influenza vaccinations effects the risk of exacerbations. Immunization; however, is recommended by the World Health Organization. Smoking bans are effective in decreasing exacerbations of asthma.

Question: What is weak that is not helping prevent the development of asthma?


Answer: none are well supported enough to be recommended for this indication

Question: What preventative measures always work to prevent asthma?


Answer: have not been found to be effective and thus are not recommended

Question: What has been determined about dietry restrictions during pregnancy and when breast feeding?


Answer: effective in decreasing exacerbations of asthma

Question: Why are smoking bans in place?


Answer: World Health Organization

Question: Who recoomends immunizations?


Answer: Avoidance of triggers

Context: Avoidance of triggers is a key component of improving control and preventing attacks. The most common triggers include allergens, smoke (tobacco and other), air pollution, non selective beta-blockers, and sulfite-containing foods. Cigarette smoking and second-hand smoke (passive smoke) may reduce the effectiveness of medications such as corticosteroids. Laws that limit smoking decrease the number of people hospitalized for asthma. Dust mite control measures, including air filtration, chemicals to kill mites, vacuuming, mattress covers and others methods had no effect on asthma symptoms. Overall, exercise is beneficial in people with stable asthma. Yoga could provide small improvements in quality of life and symptoms in people with asthma.

Question: What is a key component of control and preventing asthma attacks?


Answer: allergens, smoke (tobacco and other), air pollution, non selective beta-blockers, and sulfite-containing foods

Question: What are some of the more common triggers?


Answer: Cigarette smoking and second-hand smoke

Question: What can reduce the effectiveness of medications?


Answer: decrease the number of people hospitalized for asthma

Question: What did law that limit smoking accomplish?


Answer: Yoga

Question: What type of exercise can provide small improvements?


Answer: For those with severe persistent asthma not controlled by inhaled corticosteroids and LABAs

Context: For those with severe persistent asthma not controlled by inhaled corticosteroids and LABAs, bronchial thermoplasty may be an option. It involves the delivery of controlled thermal energy to the airway wall during a series of bronchoscopies. While it may increase exacerbation frequency in the first few months it appears to decrease the subsequent rate. Effects beyond one year are unknown. Evidence suggests that sublingual immunotherapy in those with both allergic rhinitis and asthma improve outcomes.

Question: What type of person would use bronchial thermoplasty as an option?


Answer: It involves the delivery of controlled thermal energy to the airway wall during a series of bronchoscopies

Question: What does bronchial thermoplasty consist of?


Answer: it appears to decrease the subsequent rate.

Question: What effect does bronchial thermoplasty have?


Answer: sublingual immunotherapy

Question: What treatment helps improve those with allergic rhinitis and asthma?


Answer: generally good

Context: The prognosis for asthma is generally good, especially for children with mild disease. Mortality has decreased over the last few decades due to better recognition and improvement in care. Globally it causes moderate or severe disability in 19.4 million people as of 2004 (16 million of which are in low and middle income countries). Of asthma diagnosed during childhood, half of cases will no longer carry the diagnosis after a decade. Airway remodeling is observed, but it is unknown whether these represent harmful or beneficial changes. Early treatment with corticosteroids seems to prevent or ameliorates a decline in lung function.

Question: What is the prognosis for asthma?


Answer: due to better recognition and improvement in care

Question: What has caused the mortality rate to decrease?


Answer: 19.4 million people as of 2004

Question: Worldwide, how many people suffer from asthma?


Answer: half of cases will no longer carry the diagnosis after a decade

Question: How many cases that are diagnosed in childhood make it past 10 years with asthma?


Answer: 235–330 million people worldwide are affected by asthma

Context: As of 2011, 235–330 million people worldwide are affected by asthma, and approximately 250,000–345,000 people die per year from the disease. Rates vary between countries with prevalences between 1 and 18%. It is more common in developed than developing countries. One thus sees lower rates in Asia, Eastern Europe and Africa. Within developed countries it is more common in those who are economically disadvantaged while in contrast in developing countries it is more common in the affluent. The reason for these differences is not well known. Low and middle income countries make up more than 80% of the mortality.

Question: By 2011, how many people were affected by asthma?


Answer: 250,000–345,000 people

Question: How many people die per year from asthma?


Answer: It is more common in developed than developing countries

Question: What countries is asthma more commonly seen?


Answer: The reason for these differences is not well known

Question: Why are different countries effected differently?


Answer: about $3,600

Context: From 2000 to 2010, the average cost per asthma-related hospital stay in the United States for children remained relatively stable at about $3,600, whereas the average cost per asthma-related hospital stay for adults increased from $5,200 to $6,600. In 2010, Medicaid was the most frequent primary payer among children and adults aged 18–44 years in the United States; private insurance was the second most frequent payer. Among both children and adults in the lowest income communities in the United States there is a higher rates of hospital stays for asthma in 2010 than those in the highest income communities.

Question: How much was the average cost of hospital stays for asthma-related issues for children??


Answer: from $5,200 to $6,600

Question: How much was the average cost of hospital stays for asthma-related issues for adults?


Answer: Medicaid

Question: Who was the most frequent primary payer amount children and adults?


Answer: the lowest income communities

Question: Who was more likely to seek hospital help in the US for asthma reasons?


Answer: In 1873

Context: In 1873, one of the first papers in modern medicine on the subject tried to explain the pathophysiology of the disease while one in 1872, concluded that asthma can be cured by rubbing the chest with chloroform liniment. Medical treatment in 1880, included the use of intravenous doses of a drug called pilocarpin. In 1886, F.H. Bosworth theorized a connection between asthma and hay fever. Epinephrine was first referred to in the treatment of asthma in 1905. Oral corticosteroids began to be used for this condition in the 1950s while inhaled corticosteroids and selective short acting beta agonist came into wide use in the 1960s.

Question: When was the first paper written about asthma?


Answer: by rubbing the chest with chloroform liniment

Question: What was first used as a cure for asthma?


Answer: pilocarpin

Question: In 1880 what was used intraveniously for asthma?


Answer: in the 1960s

Question: When did inhaled corticosteroids and short acting beta agonist start being used?


Answer: higher-quality

Context: Although the format was capable of offering higher-quality video and audio than its consumer rivals, the VHS and Betamax videocassette systems, LaserDisc never managed to gain widespread use in North America, largely due to high costs for the players and video titles themselves and the inability to record TV programming. It also remained a largely obscure format in Europe and Australia. By contrast, the format was much more popular in Japan and in the more affluent regions of Southeast Asia, such as Hong Kong, Singapore, and Malaysia, being the prevalent rental video medium in Hong Kong during the 1990s. Its superior video and audio quality did make it a somewhat popular choice among videophiles and film enthusiasts during its lifespan.

Question: Did LaserDisks offer higher or lower quality sound and picture than VHS?


Answer: high costs for the players and video titles themselves and the inability to record TV programming

Question: Why didn't LaserDisk gain popularity in North America?


Answer: videophiles and film enthusiasts

Question: With whom was LaserDisk a popular choice for it's picture and sound quality?


Answer: Hong Kong

Question: In what city was LaserDisk used as a popular rental medium in the 1990s?


Answer: Atlanta, Georgia

Context: LaserDisc was first available on the market, in Atlanta, Georgia, on December 15, 1978, two years after the introduction of the VHS VCR, and four years before the introduction of the CD (which is based on laser disc technology). Initially licensed, sold, and marketed as MCA DiscoVision (also known as simply "DiscoVision") in North America in 1978, the technology was previously referred to internally as Optical Videodisc System, Reflective Optical Videodisc, Laser Optical Videodisc, and Disco-Vision (with a dash), with the first players referring to the format as "Video Long Play".

Question: Where was LaserDisc first available?


Answer: two years

Question: How many years after VHS was LaserDisk released?


Answer: MCA DiscoVision

Question: Under what name was LaserDisc originally marketed?


Answer: "Video Long Play"

Question: How did the first viewers refer to the media?


Answer: Pioneer Electronics

Context: Pioneer Electronics later purchased the majority stake in the format and marketed it as both LaserVision (format name) and LaserDisc (brand name) in 1980, with some releases unofficially referring to the medium as "Laser Videodisc". Philips produced the players while MCA produced the discs. The Philips-MCA cooperation was not successful, and discontinued after a few years. Several of the scientists responsible for the early research (Richard Wilkinson, Ray Dakin and John Winslow) founded Optical Disc Corporation (now ODC Nimbus).

Question: Who purchased the majority stake and re-marketed the product in 1980?


Answer: unofficially

Question: Was Laserdisk officially or unofficially reffered to as "Laser Videodisc"?


Answer: discs

Question: Did MCA produce the disc or the players after being bought out?


Answer: Richard Wilkinson, Ray Dakin and John Winslow

Question: Who were the scientists that worked on the early research for Laserdiscs?


Answer: Optical Disc Corporation (now ODC Nimbus)

Question: What company did the early Laserdisc researchers later found?


Answer: DVD

Context: By the early 2000s, LaserDisc was completely replaced by DVD in the North American retail marketplace, as neither players nor software were then produced. Players were still exported to North America from Japan until the end of 2001. The format has retained some popularity among American collectors, and to a greater degree in Japan, where the format was better supported and more prevalent during its life. In Europe, LaserDisc always remained an obscure format. It was chosen by the British Broadcasting Corporation (BBC) for the BBC Domesday Project in the mid-1980s, a school-based project to commemorate 900 years since the original Domesday Book in England. From 1991 up until the early 2000s, the BBC also used LaserDisc technology to play out the channel idents.

Question: What product replaced LaserDisc in North America by the early 2000s?


Answer: British Broadcasting Corporation (BBC)

Question: Who chose LaserFisc for their Domesday Project in the mid-1980s?


Answer: a school-based project to commemorate 900 years since the original Domesday Book in England

Question: What was the BBC Domesday Project?


Answer: Japan

Question: Which country still exported players to North America until 2001?


Answer: 30 cm (12 in) in diameter

Context: The standard home video LaserDisc was 30 cm (12 in) in diameter and made up of two single-sided aluminum discs layered in plastic. Although appearing similar to compact discs or DVDs, LaserDiscs used analog video stored in the composite domain (having a video bandwidth approximately equivalent to the 1-inch (25 mm) C-Type VTR format) with analog FM stereo sound and PCM digital audio. The LaserDisc at its most fundamental level was still recorded as a series of pits and lands much like CDs, DVDs, and even Blu-ray Discs are today. However, while the encoding is of a binary nature, the information is encoded as analog pulse width modulation with a 50% duty cycle, where the information is contained in the lengths and spacing of the pits. In true digital media the pits, or their edges, directly represent 1s and 0s of a binary digital information stream. Early LaserDiscs featured in 1978 were entirely analog but the format evolved to incorporate digital stereo sound in CD format (sometimes with a TOSlink or coax output to feed an external DAC), and later multi-channel formats such as Dolby Digital and DTS.

Question: How large was a standard LaserDisc?


Answer: 1s and 0s

Question: What numbers are used in Binary information coding?


Answer: analog

Question: Were the ealiest LaserDiscs in 1978 analog or digitally formatted?


Answer: 55 minutes 5 seconds

Context: As Pioneer introduced Digital Audio to LaserDisc in 1985, they further refined the CAA format. CAA55 was introduced in 1985 with a total playback capacity per side of 55 minutes 5 seconds, reducing the video capacity to resolve bandwidth issues with the inclusion of Digital Audio. Several titles released between 1985 and 1987 were analog audio only due to the length of the title and the desire to keep the film on one disc (e.g., Back to the Future). By 1987, Pioneer had overcome the technical challenges and was able to once again encode in CAA60, allowing a total of 60 minutes 5 seconds. Pioneer further refined CAA, offering CAA45, encoding 45 minutes of material, but filling the entire playback surface of the side. Used on only a handful of titles, CAA65 offered 65 minutes 5 seconds of playback time per side. There are a handful of titles pressed by Technidisc that used CAA50. The final variant of CAA is CAA70, which could accommodate 70 minutes of playback time per side. There are not any known uses of this format on the consumer market.

Question: What was the length capacity of the CAA55 format?


Answer: due to the length of the title and the desire to keep the film on one disc

Question: Why was Back to the Future released with analog sound?


Answer: 60 minutes 5 seconds

Question: What was the maximum length of the CAA60 format?


Answer: There are not any known uses of this format on the consumer market

Question: How many works were released to the public with the CAA70 format?


Answer: "LaserVision" is used to refer to discs with analog sound, while "LaserDisc" is used for those with digital audio

Context: Sound could be stored in either analog or digital format and in a variety of surround sound formats; NTSC discs could carry two analog audio tracks, plus two uncompressed PCM digital audio tracks, which were (EFM, CIRC, 16-bit and 44.056 kHz sample rate). PAL discs could carry one pair of audio tracks, either analog or digital and the digital tracks on a PAL disc were 16-bit 44.1 kHz as on a CD; in the UK, the term "LaserVision" is used to refer to discs with analog sound, while "LaserDisc" is used for those with digital audio. The digital sound signal in both formats are EFM-encoded as in CD. Dolby Digital (also called AC-3) and DTS—which are now common on DVD titles—first became available on LaserDisc, and Star Wars: Episode I – The Phantom Menace (1999) which was released on LaserDisc in Japan, is among the first home video releases ever to include 6.1 channel Dolby Digital EX Surround. Unlike DVDs, which carry Dolby Digital audio in digital form, LaserDiscs store Dolby Digital in a frequency modulated form within a track normally used for analog audio. Extracting Dolby Digital from a LaserDisc required a player equipped with a special "AC-3 RF" output and an external demodulator in addition to an AC-3 decoder. The demodulator was necessary to convert the 2.88 MHz modulated AC-3 information on the disc into a 384 kbit/s signal that the decoder could handle. DTS audio, when available on a disc, replaced the digital audio tracks; hearing DTS sound required only an S/PDIF compliant digital connection to a DTS decoder.

Question: What was the difference between LaserDisc and LaserVision in the UK?


Answer: 6.1 channel Dolby Digital EX Surround.

Question: The Phantom Menace was one of the first home videos to use what sound format?


Answer: Dolby Digital audio in digital form

Question: What sound formatting do DVDs use?


Answer: DVD's growing popularity

Context: In the mid to late 1990s many higher-end AV receivers included the demodulator circuit specifically for the LaserDisc players RF modulated Dolby Digital AC-3 signal. By the late 1990s with LaserDisc players and disc sales declining due to DVD's growing popularity the AV receiver manufacturers removed the demodulator circuit. Although DVD players were capable of playing Dolby Digital tracks, the signal out of DVD player were not in a modulated form and not compatible with the inputs designed for LaserDisc AC-3. Outboard demodulators were available for a period that convert the AC-3 signal to standard Dolby Digital signal that was compatible with the standard Dolby Digital/PCM inputs on capable AV receivers. Another type marketed by Onkyo and others converted the RF AC-3 signal to 6-channel analog audio.

Question: What competition caused LaserDisc sales to decline?


Answer: higher-end

Question: Did all AV receivers carry the demodulator circuits necessary for LaserDiscs, or only high-end models?


Answer: 6-channel analog audio

Question: What did the Onkyo outboard demodulator covert the RF AC-2 signal to?


Answer: varied greatly

Context: At least where the digital audio tracks were concerned, the sound quality was unsurpassed at the time compared to consumer videotape, but the quality of the analog soundtracks varied greatly depending on the disc and, sometimes, the player. Many early and lower-end LD players had poor analog audio components, and many early discs had poorly mastered analog audio tracks, making digital soundtracks in any form most desirable to serious enthusiasts. Early DiscoVision and LaserDisc titles lacked the digital audio option, but many of those movies received digital sound in later re-issues by Universal, and the quality of analog audio tracks generally got far better as time went on. Many discs that had originally carried old analog stereo tracks received new Dolby Stereo and Dolby Surround tracks instead, often in addition to digital tracks, helping boost sound quality. Later analog discs also applied CX Noise Reduction, which improved the signal-noise ratio of their audio.

Question: Was sound quality from disc to disc and between players consistent or varied?


Answer: digital

Question: Was analog or digital formatting more popular with enthusiasts?


Answer: improved the signal-noise ratio of their audio

Question: What result did adding CX Noise Reduction have on analog discs?


Answer: Universal

Question: Which company added digital sound option when re-releasing movies?


Answer: right analog audio channel

Context: Both AC-3 and DTS surround audio were clumsily implemented on LaserDiscs, leading to some interesting player- and disc-dependent issues. A disc that included AC-3 audio forfeited the right analog audio channel to the modulated AC-3 RF stream. If the player did not have an AC-3 output available, the next most attractive playback option would be the digital Dolby Surround or stereo audio tracks. The reason for this is the RF signal needs to bypass the audio circuitry in order to be properly processed by the demodulator. If either the player did not support digital audio tracks (common in older players), or the disc did not include digital audio tracks at all (uncommon for a disc which is mastered with an AC-3 track), the only remaining option was to fall back to a monophonic presentation of the left analog audio track. However, many older analog-only players not only failed to output AC-3 streams correctly, but were not even aware of their potential existence. Such a player will happily play the analog audio tracks verbatim, resulting in garbage (static) output in the right channel.

Question: Which channel would not work in conjunction with AC-3 audio?


Answer: digital Dolby Surround or stereo audio tracks

Question: What audio playback options were available if an AC-3 output was not present?


Answer: garbage (static) output

Question: What happens to the right channel in a player that doesn't recognize AC-3?


Answer: rare

Context: Only one 5.1 surround sound option exists on a given LaserDisc (either Dolby Digital or DTS), so if surround sound is desired, the disc must be matched to the capabilities of the playback equipment (LD Player and Receiver/Decoder) by the purchaser. A fully capable LaserDisc playback system includes a newer LaserDisc player that is capable of playing digital tracks, has a digital optical output for digital PCM and DTS audio, is aware of AC-3 audio tracks, and has an AC-3 coaxial output; an external or internal AC-3 RF demodulator and AC-3 decoder; and a DTS decoder. Many 1990s A/V receivers combine the AC-3 decoder and DTS decoder logic, but an integrated AC-3 demodulator is rare both in LaserDisc players and in later A/V receivers.

Question: Are integrated AC-3 demodulators common in LaserDisc players or a rare find?


Answer: Only one

Question: How many 5.1 surround sound options exist in LaserDiscs?


Answer: DTS

Question: What type of decoder logic is common in 1990s A/V receivers?


Answer: PAL LaserDiscs

Context: PAL LaserDiscs have a slightly longer playing time than NTSC discs, but have fewer audio options. PAL discs only have two audio tracks, consisting of either two analog-only tracks on older PAL LDs, or two digital-only tracks on newer discs. In comparison, later NTSC LDs are capable of carrying four tracks (two analog and two digital). On certain releases, one of the analog tracks is used to carry a modulated AC-3 signal for 5.1 channel audio (for decoding and playback by newer LD players with an "AC-3 RF" output). However, older NTSC LDs made before 1984 (such as the original DiscoVision discs) only have two analog audio tracks.

Question: Which has a longer playing time: PAL LaserDiscs or NTSC discs?


Answer: two

Question: How many audio tracks do PAL LaserDiscs have?


Answer: two analog-only tracks on older PAL LDs, or two digital-only tracks on newer discs

Question: Which two audio options are available on PAL LaserDiscs?


Answer: LD-700

Context: In March 1984, Pioneer introduced the first consumer player with a solid-state laser, the LD-700. It was also the first LD player to load from the front and not the top. One year earlier Hitachi introduced an expensive industrial player with a laser diode, but the player, which had poor picture quality due to an inadequate dropout compensator, was made only in limited quantities. After Pioneer released the LD-700, gas lasers were no longer used in consumer players, despite their advantages, although Philips continued to use gas lasers in their industrial units until 1985.

Question: What was the name of the first solid-state laser consumer LaserDisc player?


Answer: first LD player to load from the front and not the top

Question: Besides a solid-state laser, what else was unique about the LD-700?


Answer: March 1984

Question: When did Pioneer release the LD-700?


Answer: Philips

Question: Which company continued to use gas-lasers in industrial models of LD players although they were no longer used in consumer models?


Answer: Optical Videodisc System, "Reflective Optical Videodisc" or "Laser Optical Videodisc"

Context: During its development, MCA, which co-owned the technology, referred to it as the Optical Videodisc System, "Reflective Optical Videodisc" or "Laser Optical Videodisc", depending on the document; changing the name once in 1969 to Disco-Vision and then again in 1978 to DiscoVision (without the hyphen), which became the official spelling. Technical documents and brochures produced by MCA Disco-Vision during the early and mid-'70s also used the term "Disco-Vision Records" to refer to the pressed discs. MCA owned the rights to the largest catalog of films in the world during this time, and they manufactured and distributed the DiscoVision releases of those films under the "MCA DiscoVision" software and manufacturing label; consumer sale of those titles began on December 15, 1978, with the aforementioned Jaws.

Question: Which three names did MCA use for LaserDisc technology during its development?


Answer: Disco-Vision

Question: To what did MCA change the name to in 1969?


Answer: 1978

Question: When did MCA remove the hyphen from the name Disco-Vision?


Answer: MCA

Question: Which company owned the rights to the world's largest collection of films during the 1970s?


Answer: Jaws

Question: Consumer sales of MCA films began in 1978 with what movie?


Answer: Video Long-Play

Context: Philips' preferred name for the format was "VLP", after the Dutch words Video Langspeel-Plaat ("Video long-play disc"), which in English-speaking countries stood for Video Long-Play. The first consumer player, the Magnavox VH-8000 even had the VLP logo on the player. For a while in the early and mid-1970s, Philips also discussed a compatible audio-only format they called "ALP", but that was soon dropped as the Compact Disc system became a non-compatible project in the Philips corporation. Until early 1980, the format had no "official" name. The LaserVision Association, made up of MCA, Universal-Pioneer, IBM, and Philips/Magnavox, was formed to standardize the technical specifications of the format (which had been causing problems for the consumer market) and finally named the system officially as "LaserVision".

Question: What did VLP stand for in English-speaking countries?


Answer: Magnavox VH-8000

Question: What was the first consumer VLP player?


Answer: The LaserVision Association

Question: Which group officially chose the name "Laservision"?


Answer: MCA, Universal-Pioneer, IBM, and Philips/Magnavox

Question: The Laservision Association was comprised of which companies?


Answer: Pioneer Electronics

Context: Pioneer Electronics also entered the optical disc market in 1977 as a 50/50 joint-venture with MCA called Universal-Pioneer and manufacturing MCA designed industrial players under the MCA DiscoVision name (the PR-7800 and PR-7820). For the 1980 launch of the first Universal-Pioneer player, the VP-1000 was noted as a "laser disc player", although the "LaserDisc" logo displayed clearly on the device. In 1981, "LaserDisc" was used exclusively for the medium itself, although the official name was "LaserVision" (as seen at the beginning of many LaserDisc releases just before the start of the film). However, as Pioneer reminded numerous video magazines and stores in 1984, LaserDisc was a trademarked word, standing only for LaserVision products manufactured for sale by Pioneer Video or Pioneer Electronics. A 1984 Ray Charles ad for the LD-700 player bore the term "Pioneer LaserDisc brand videodisc player". From 1981 until the early 1990s, all properly licensed discs carried the LaserVision name and logo, even Pioneer Artists titles.

Question: Which company joined a 50/50 partnership with MCA in 1977?


Answer: 1980

Question: In what year was the first Universal-Pioneer player released?


Answer: the VP-1000

Question: What was the name of the first Universal-Pioneer player?


Answer: Ray Charles

Question: Which singer did an ad for the LD-700 player in 1984?


Answer: Paramount, Disney and Warner Bros

Context: During the early years, MCA also manufactured discs for other companies including Paramount, Disney and Warner Bros. Some of them added their own names to the disc jacket to signify that the movie was not owned by MCA. After Discovision Associates shut down in early 1982, Universal Studio's videodisc software label, called MCA Videodisc until 1984, began reissuing many DiscoVision titles. Unfortunately, quite a few, such as Battlestar Galactica and Jaws, were time-compressed versions of their CAV or CLV Disco Vision originals. The time-compressed CLV re-issue of Jaws no longer had the original soundtrack, having had incidental background music replaced for the video disc version due to licensing cost (the music would not be available until the THX LaserDisc box set was released in 1995). One Universal/Columbia co-production issued by MCA Disco Vision in both CAV and CLV versions, The Electric Horseman, is still not available in any other home video format with its original score intact; even the most recent DVD release has had substantial music replacements of both instrumental score and Willie Nelson's songs. An MCA release of Universal's Howard the Duck, sees only the start credits shown in widescreen before changing to 4:3 for the rest of the film. For many years this was the only disc-based release of the film, until widescreen DVD formats were released with extras. Also, the LaserDisc release of E.T. the Extra-Terrestrial is the only format to include the cut scene of Harrison Ford playing the part of the school headmaster telling off Elliott for letting the frogs free in the biology class.

Question: What other companies did MCA manufacture discs for?


Answer: only the start credits shown in widescreen before changing to 4:3 for the rest of the film

Question: What quirk is present in MCA's release of Howard the Duck?


Answer: only format to include the cut scene of Harrison Ford playing the part of the school headmaster

Question: What is unique about the LaserDisc release of E.T.?


Answer: The Electric Horseman

Question: Which film is only available with its original score in LD format , even today?


Answer: 425

Context: LaserDisc had a number of advantages over VHS. It featured a far sharper picture with a horizontal resolution of 425 TVL lines for NTSC and 440 TVL lines for PAL discs, while VHS featured only 240 TVL lines with NTSC. It could handle analog and digital audio where VHS was mostly analog only (VHS can have PCM audio in professional applications but is uncommon), and the NTSC discs could store multiple audio tracks. This allowed for extras like director's commentary tracks and other features to be added onto a film, creating "Special Edition" releases that would not have been possible with VHS. Disc access was random and chapter based, like the DVD format, meaning that one could jump to any point on a given disc very quickly. By comparison, VHS would require tedious rewinding and fast-forwarding to get to specific points.

Question: How many horizontal TVL lines did LaserDisc have in comparison to VHS's 240?


Answer: LaserDisc

Question: Which medium was chapter based like DVD format, Laserdisc or VHS?


Answer: LaserDisc

Question: Which medium allowed for multiple audio tracks, Laserdisc or VHS?


Answer: cheaper

Context: LaserDiscs were initially cheaper than videocassettes to manufacture, because they lacked the moving parts and plastic outer shell that are necessary for VHS tapes to work, and the duplication process was much simpler. A VHS cassette has at least 14 parts including the actual tape while LaserDisc has one part with five or six layers. A disc can be stamped out in a matter of seconds whereas duplicating videotape required a complex bulk tape duplication mechanism and was a time-consuming process. However, by the end of the 1980s, average disc-pressing prices were over $5.00 per two-sided disc, due to the large amount of plastic material and the costly glass-mastering process needed to make the metal stamper mechanisms. Due to the larger volume of demand, videocassettes quickly became much cheaper to duplicate, costing as little as $1.00 by the beginning of the 1990s.

Question: Were Laserdiscs initially cheaper or more costly to produce than their VHS counterparts?


Answer: at least 14

Question: How many parts does a VHS tape have that must be manufactured?


Answer: $5.00 per two-sided disc

Question: How much did LaserDiscs cost to produce by the end of the 1980s?


Answer: as little as $1.00

Question: How much did VHS cost to produce by the 1990s?


Answer: LaserDiscs

Context: LaserDiscs potentially had a much longer lifespan than videocassettes. Because the discs were read optically instead of magnetically, no physical contact needs to be made between the player and the disc, except for the player's clamp that holds the disc at its center as it is spun and read. As a result, playback would not wear the information-bearing part of the discs, and properly manufactured LDs would theoretically last beyond one's lifetime. By contrast, a VHS tape held all of its picture and sound information on the tape in a magnetic coating which is in contact with the spinning heads on the head drum, causing progressive wear with each use (though later in VHS's lifespan, engineering improvements allowed tapes to be made and played back without contact). Also, the tape was thin and delicate, and it was easy for a player mechanism, especially on a low quality or malfunctioning model, to mishandle the tape and damage it by creasing it, frilling (stretching) its edges, or even breaking it.

Question: Were Laserdiscs or VHS more durable in the long run?


Answer: progressive wear with each use

Question: Why is physical contact with a VHS tape less desirable than an optical reading?


Answer: magnetic coating

Question: Where do VHS tapes store their information?


Answer: digital blocks which make up each independent frame

Context: LaserDisc was a composite video format: the luminance (black and white) and chrominance (color) information were transmitted in one signal, separated by the receiver. While good comb filters can do so adequately, these two signals cannot be completely separated. On DVDs, data is stored in the form of digital blocks which make up each independent frame. The signal produced is dependent on the equipment used to master the disc. Signals range from composite and split, to YUV and RGB. Depending upon which format is used, this can result in far higher fidelity, particularly at strong color borders or regions of high detail (especially if there is moderate movement in the picture) and low-contrast details like skin tones, where comb filters almost inevitably smudge some detail.

Question: How is data stored on DVDs?


Answer: the receiver

Question: What device seperated the black and white and color signals in LaserDiscs?


Answer: low-contrast details like skin tones

Question: In what areas are comb filters most likely to lose detail?


Answer: comb filters almost inevitably smudge some detail

Question: Are comb filters exact, or is some data smudged?


Answer: LaserDiscs

Context: In contrast to the entirely digital DVD, LaserDiscs use only analog video. As the LaserDisc format is not digitally encoded and does not make use of compression techniques, it is immune to video macroblocking (most visible as blockiness during high motion sequences) or contrast banding (subtle visible lines in gradient areas, such as out-of-focus backgrounds, skies, or light casts from spotlights) that can be caused by the MPEG-2 encoding process as video is prepared for DVD. Early DVD releases held the potential to surpass their LaserDisc counterparts, but often managed only to match them for image quality, and in some cases, the LaserDisc version was preferred. However, proprietary human-assisted encoders manually operated by specialists can vastly reduce the incidence of artifacts, depending on playing time and image complexity. By the end of LaserDisc's run, DVDs were living up to their potential as a superior format.

Question: Do LaserDiscs or DVD use analog video?


Answer: entirely

Question: Are DVDs partially or entirely digital?


Answer: subtle visible lines in gradient areas

Question: What is contrast banding?


Answer: MPEG-2 encoding process

Question: What step of the DVD production process causes contrast banding?


Answer: the transport mechanism always obeys commands from the user

Context: LaserDisc players can provide a great degree of control over the playback process. Unlike many DVD players, the transport mechanism always obeys commands from the user: pause, fast-forward, and fast-reverse commands are always accepted (barring, of course, malfunctions). There were no "User Prohibited Options" where content protection code instructs the player to refuse commands to skip a specific part (such as fast forwarding through copyright warnings). (Some DVD players, particularly higher-end units, do have the ability to ignore the blocking code and play the video without restrictions, but this feature is not common in the usual consumer market.)

Question: How does LaserDisc operation vary from DVD?


Answer: where content protection code instructs the player to refuse commands to skip a specific part

Question: What are "User Protected Options" on DVDs?


Answer: copyright warnings

Question: Where are User Protected Options commonly found on DVDs?


Answer: LaserDisc

Question: Which format, LaserDisc or DVD, gives the user the most control over playback?


Answer: filling in unreadable areas of the picture with blank space or a frozen frame of the last readable image and sound

Context: Damaged spots on a LaserDisc can be played through or skipped over, while a DVD will often become unplayable past the damage. Some newer DVD players feature a repair+skip algorithm, which alleviates this problem by continuing to play the disc, filling in unreadable areas of the picture with blank space or a frozen frame of the last readable image and sound. The success of this feature depends upon the amount of damage. LaserDisc players, when working in full analog, recover from such errors faster than DVD players. Direct comparison here is almost impossible due to the sheer size differences between the two media. A 1 in (3 cm) scratch on a DVD will probably cause more problems than a 1 in (3 cm) scratch on a LaserDisc, but a fingerprint taking up 1% of the area of a DVD would almost certainly cause fewer problems than a similar mark covering 1% of the surface of a LaserDisc.[citation needed]

Question: What does the repair+skip feature on newer DVD players do?


Answer: DVD

Question: Which format, DVD or Laserdisc, can become unreadable with damage?


Answer: DVD

Question: Will the same size scratch cause more problems for a DVD or LaserDisc?


Answer: LaserDisc

Context: Similar to the CD versus LP sound quality debates common in the audiophile community, some videophiles argue that LaserDisc maintains a "smoother", more "film-like", natural image while DVD still looks slightly more artificial. Early DVD demo discs often had compression or encoding problems, lending additional support to such claims at the time. However, the video signal-to-noise ratio and bandwidth of LaserDisc are substantially less than that of DVDs, making DVDs appear sharper and clearer to most viewers.

Question: Which format is considered to look most realistic, LaserDisc or DVD?


Answer: DVDs

Question: Which format, LaserDisc or DVD, is said to appear sharper and clearer to most viewers?


Answer: video signal-to-noise ratio and bandwidth

Question: What features do LaserDiscs lack in, causing DVDs to appear sharper and clearer?


Answer: internal timing

Context: Another advantage, at least to some consumers, was the lack of any sort of anti-piracy technology. It was claimed that Macrovision's Copyguard protection could not be applied to LaserDisc, due to the format's design. The vertical blanking interval, where the Macrovision signal would be implemented, was also used for the internal timing on LaserDisc players, so test discs with Macrovision would not play at all. There was never a push to redesign the format despite the obvious potential for piracy due to its relatively small market share. The industry simply decided to engineer it into the DVD specification.

Question: What was the vertical blanking interval used for in LaserDiscs, preventing Macrovision signal to be implemented?


Answer: relatively small market share

Question: Why wasn't there a need to redesign the LaserDisc format to prevent piracy?


Answer: Macrovision's Copyguard protection

Question: What protection could not be applied to LaserDiscs, making them prone to piracy?


Answer: "Special Edition"

Context: LaserDisc's support for multiple audio tracks allowed for vast supplemental materials to be included on-disc and made it the first available format for "Special Edition" releases; the 1984 Criterion Collection edition of Citizen Kane is generally credited as being the first "Special Edition" release to home video,[citation needed] and for setting the standard by which future SE discs were measured. The disc provided interviews, commentary tracks, documentaries, still photographs, and other features for historians and collectors.

Question: LaserDisc was the first format to provide what type of releases to consumers?


Answer: the 1984 Criterion Collection edition of Citizen Kane

Question: What was the first "Special Edition" film to be released to home video?


Answer: interviews, commentary tracks, documentaries, still photographs

Question: What bonus features were available on the first home video "Special Edition"?


Answer: support for multiple audio tracks

Question: What feature, unique to LaserDisc, made bonus content possible?


Answer: a disc has to be flipped over in order to continue watching

Context: The space-consuming analog video signal of a LaserDisc limited playback duration to 30 minutes (CAV) or 60 minutes (CLV) per side because of the hardware manufacturer's refusal to reduce line count for increased playtime. After one side was finished playing, a disc has to be flipped over in order to continue watching a movie, and some titles fill two or more discs. Many players, especially units built after the mid-1980s, can "flip" discs automatically by rotating the optical pickup to the other side of the disc, but this is accompanied by a pause in the movie during the side change. If the movie is longer than what could be stored on two sides of a single disc, manually swapping to a second disc is necessary at some point during the film. One exception to this rule is the Pioneer LD-W1, which features two disc platters. In addition, perfect still frames and random access to individual still frames is limited only to the more expensive CAV discs, which only had a playing time of approximately 30 minutes per side. In later years, Pioneer and other manufacturers overcame this limitation by incorporating a digital memory buffer, which "grabbed" a single frame from a CLV disc.

Question: What was required of a LaserDisc to continue playback after 60 minutes?


Answer: Pioneer LD-W1

Question: Which LaserDisc player solves the disc switching dilemma?


Answer: line count

Question: What must be reduced in order to allow LaserDisc playback time to increase?


Answer: CLV

Question: Which format allows for more playback tie per side, CLV or CAV?


Answer: glitches, streaks, bursts of static, or momentary picture interruptions

Context: The analog information encoded on LaserDiscs does not include any form of built-in checksum or error correction. Because of this, slight dust and scratches on the disc surface can result in read-errors which cause various video quality problems: glitches, streaks, bursts of static, or momentary picture interruptions. In contrast, the digital MPEG-2 format information used on DVDs has built-in error correction which ensures that the signal from a damaged disc will remain identical to that from a perfect disc right up until the point at which damage to the disc surface is so substantial that it prevents the laser from being able to identify usable data.

Question: What video problems on a LaserDisc can be caused by dust or scratches?


Answer: digital MPEG-2

Question: Which format used in DVDs has built-in error correction?


Answer: analog

Question: What type of encoding, analog or digital, causes LaserDiscs to be succeptable to damages?


Answer: when the laser optical pickup assembly within the player is out of alignment or because the disc is damaged or excessively warped

Context: In addition, LaserDisc videos sometimes exhibit a problem known as "crosstalk". The issue can arise when the laser optical pickup assembly within the player is out of alignment or because the disc is damaged or excessively warped, but it could also occur even with a properly functioning player and a factory-new disc, depending on electrical and mechanical alignment problems. In these instances, the issue arose due to the fact that CLV discs require subtle changes in rotating speed at various points during playback. During a change in speed, the optical pickup inside the player might read video information from a track adjacent to the intended one, causing data from the two tracks to "cross"; the extra video information picked up from that second track shows up as distortion in the picture which looks reminiscent of swirling "barber poles" or rolling lines of static.

Question: When does "crosstalk" occur?


Answer: "crosstalk"

Question: What problem can be caused by a player becoming out of alignment?


Answer: swirling "barber poles" or rolling lines of static

Question: How does "crosstalk" appear to the viewer?