197-550: The CONMEBOL Copa América (English: Americas Cup ; known until 1975 as the South American Football Championship ), often simply called the Copa America , is the top men's quadrennial football tournament contested among national teams from South America . It is the oldest still-running continental football competition. The competition determines the champions of South America. Since
394-477: A dry cough , sore or dry throat , hoarse voice , and a stuffy or runny nose . Coughing is the most common symptom. Gastrointestinal symptoms may also occur, including nausea, vomiting, diarrhea, and gastroenteritis, especially in children. The standard influenza symptoms typically last for two to eight days. Some studies suggest influenza can cause long-lasting symptoms in a similar way to long COVID . Symptomatic infections are usually mild and limited to
591-458: A runny nose . The time between exposure to the virus and development of symptoms (the incubation period ) is one to four days, most commonly one to two days. Many infections are asymptomatic. The onset of symptoms is sudden, and initial symptoms are predominately non-specific, including fever, chills, headaches, muscle pain , malaise , loss of appetite , lack of energy, and confusion. These are usually accompanied by respiratory symptoms such as
788-407: A single-elimination knockout stage. The tournament was previously known as Campeonato Sudamericano de Futbol (South American Championship of Football). South American Championship of Nations was the official English language name. The current name has been used since 1975. Up to 1967 if there was a tie of points at the top of the standings, a playoff match (or matches) would be held to determine
985-628: A stele of c. 375–400 BCE in the National Archaeological Museum of Athens appears on the UEFA European Championship trophy. Athenaeus , writing in 228 CE, mentions the Roman ball game harpastum . Phaininda, episkyros and harpastum were played involving hands and violence. They all appear to have resembled rugby football , wrestling , and volleyball more than what
1182-493: A French XI team in 1920, and also made up most of the England team against a Scottish Ladies XI in the same year, winning 22–0. Despite being more popular than some men's football events, with one match seeing a 53,000 strong crowd in 1920, women's football in England suffered a blow in 1921 when The Football Association outlawed the playing of the game on association members' pitches, stating that "the game of football
1379-442: A caution ( yellow card ) or dismissal ( red card ). A second yellow card in the same game leads to a red card, which results in a dismissal. A player given a yellow card is said to have been "booked", the referee writing the player's name in their official notebook. If a player has been dismissed, no substitute can be brought on in their place and the player may not participate in further play. Misconduct may occur at any time, and while
1576-519: A certain strain in childhood still possess antibodies to that strain at a reasonable level later in life, which can provide some protection to related strains. There is, however, an " original antigenic sin ", in which the first HA subtype a person is exposed to influences the antibody-based immune response to future infections and vaccines. Annual vaccination is the primary and most effective way to prevent influenza and influenza-associated complications, especially for high-risk groups. Vaccines against
1773-626: A collaborative partnership agreement in January 2023 that included the United States being selected as host for the 2024 Copa América , which would feature six CONCACAF teams. The tournament would share some venues with the 2026 FIFA World Cup , which is planned to be co-hosted by the United States. In 1984, CONMEBOL adopted the policy of rotating the right to host the Copa América amongst the ten member confederations. The first rotation
1970-574: A competitive game, and involved the kicking of a mari , a ball made of animal skin. In North America, pasuckuakohowog was a ball game played by the Algonquians ; it was described as "almost identical to the kind of folk football being played in Europe at the same time, in which the ball was kicked through goals". Phaininda and episkyros were Greek ball games. An image of an episkyros player depicted in low relief on
2167-901: A culture of mammalian cells or embryonated eggs for 3–10 days to monitor cytopathic effect. Final confirmation can then be done via antibody staining, hemadsorption using red blood cells , or immunofluorescence microscopy. Shell vial cultures, which can identify infection via immunostaining before a cytopathic effect appears, are more sensitive than traditional cultures with results in 1–3 days. Cultures can be used to characterize novel viruses, observe sensitivity to antiviral drugs, and monitor antigenic drift, but they are relatively slow and require specialized skills and equipment. Serological assays can be used to detect an antibody response to influenza after natural infection or vaccination. Common serological assays include hemagglutination inhibition assays that detect HA-specific antibodies, virus neutralization assays that check whether antibodies have neutralized
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#17327722024572364-505: A deadlock; some competitions may invoke replays . A game tied at the end of regulation time may go into extra time, which consists of two further 15-minute periods. If the score is still tied after extra time, some competitions allow the use of penalty shoot-outs (known officially in the Laws of the Game as "kicks from the penalty mark") to determine which team will progress to the next stage of
2561-461: A distinct "head" and "stalk" structure. M2 proteins form proton channels through the viral envelope that are required for viral entry and exit. Influenza B viruses contain a surface protein named NB that is anchored in the envelope, but its function is unknown. The viral life cycle begins by binding to a target cell. Binding is mediated by the viral HA proteins on the surface of the envelope, which bind to cells that contain sialic acid receptors on
2758-554: A formula based on the FIFA World Rankings . The other teams are assigned to different "pots", usually based also on the FIFA Rankings, and teams in each pot are drawn at random to the three groups. Each group plays a round-robin tournament , in which each team is scheduled for three matches against other teams in the same group. In earlier tournaments, the last round of matches of each group were not scheduled at
2955-400: A goal has been scored or not; this was brought in to prevent controversy. Video assistant referees (VAR) have also been increasingly introduced in high-level matches to assist officials through video replays to correct clear and obvious mistakes. There are four types of calls that can be reviewed: mistaken identity in awarding a red or yellow card, goals and whether there was a violation during
3152-425: A hemagglutinin-esterase fusion (HEF) protein on one segment that merges the functions of HA and NA. The final genome segment encodes the viral nucleoprotein (NP). Influenza viruses also encode various accessory proteins, such as PB1-F2 and PA-X, that are expressed through alternative open reading frames and which are important in host defense suppression, virulence, and pathogenicity. The virus particle, called
3349-401: A higher risk of developing complications if these individuals are still shedding the virus. Antiviral treatment is also recommended if a person is hospitalized with suspected influenza instead of waiting for test results to return and if symptoms are worsening. Most antiviral drugs against influenza fall into two categories: neuraminidase (NA) inhibitors and M2 inhibitors. Baloxavir marboxil is
3546-613: A higher temperature than mammalian influenza viruses. Newly synthesized viral polymerase subunits and NP proteins are imported to the nucleus to further increase the rate of viral replication and form RNPs. HA, NA, and M2 proteins are trafficked with the aid of M1 and NEP proteins to the cell membrane through the Golgi apparatus and inserted into the cell's membrane. Viral non-structural proteins including NS1, PB1-F2, and PA-X regulate host cellular processes to disable antiviral responses. PB1-F2 also interacts with PB1 to keep polymerases in
3743-640: A latex bladder for pressurisation, but modern balls at all levels of the game are now synthetic. As the Laws were formulated in England, and were initially administered solely by the four British football associations within IFAB , the standard dimensions of a football pitch were originally expressed in imperial units . The Laws now express dimensions with approximate metric equivalents (followed by traditional units in brackets), though use of imperial units remains popular in English-speaking countries with
3940-553: A limited number, so it is difficult to predict when the next will happen. The Global Influenza Surveillance and Response System of the World Health Organization (GISRS) tests several millions of specimens annually to monitor the spread and evolution of influenza viruses. People who are infected can transmit influenza viruses through breathing, talking, coughing, and sneezing, which spread respiratory droplets and aerosols that contain virus particles into
4137-414: A major focus of research pertaining to antiviral drugs, vaccines, and other measures against influenza. Influenza C virus is subclassified into six genetic/antigenic lineages. Influenza D virus has been isolated from pigs and cattle, the latter being the natural reservoir. Infection has also been observed in humans, horses, dromedary camels, and small ruminants such as goats and sheep. Influenza D virus
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#17327722024574334-529: A meeting attended by representatives from Eton , Harrow , Rugby , Winchester and Shrewsbury schools. They were not universally adopted. During the 1850s, many clubs unconnected to schools or universities were formed throughout the English-speaking world to play various forms of football. Some came up with their own distinct codes of rules, most notably the Sheffield Football Club , formed by former public school pupils in 1857, which led to
4531-472: A merger of the Copa América with the CONCACAF Gold Cup , the latter's continental tournament held every two years, with the United States hosting regular tournaments; United States Soccer Federation president Sunil Gulati called the report inaccurate, saying that no such discussion had taken place and that a new tournament would have to be established. For the second time, Chile won the trophy in
4728-450: A pandemic. Influenza C virus, like influenza B virus, is primarily found in humans, though it has been detected in pigs, feral dogs, dromedary camels, cattle, and dogs. Influenza C virus infection primarily affects children and is usually asymptomatic or has mild cold-like symptoms, though more severe symptoms such as gastroenteritis and pneumonia can occur. Unlike influenza A virus and influenza B virus, influenza C virus has not been
4925-426: A penalty kick. Other markings define the position of the ball or players at kick-offs , goal kicks, penalty kicks and corner kicks. A standard adult football match consists of two halves of 45 minutes each. Each half runs continuously, meaning that the clock is not stopped when the ball is out of play. There is usually a 15-minute half-time break between halves. The end of the match is known as full-time. The referee
5122-428: A penalty shoot-out. The 2016 edition broke tournament records for attendance, with 1.5 million total spectators and an average of 46,000 per match through the semi-finals. Brazil hosted the 2019 edition, which was played in the normal four-year cycle, and won their ninth title by defeating Peru in the final at the renovated Maracanã Stadium . CONMEBOL approved a permanent switch from odd to even years beginning with
5319-449: A period of improvement in symptoms for one to three weeks followed by recurrent fever, sputum production, and fluid buildup in the lungs , but can also occur just a few days after influenza symptoms appear. About a third of primary pneumonia cases are followed by secondary pneumonia, which is most frequently caused by the bacteria Streptococcus pneumoniae and Staphylococcus aureus . Influenza viruses comprise four species, each
5516-416: A relatively recent history of metrication (or only partial metrication), such as Britain. The length of the pitch, or field, for international adult matches is in the range of 100–110 m (110–120 yd) and the width is in the range of 64–75 m (70–80 yd). Fields for non-international matches may be 90–120 m (100–130 yd) in length and 45–90 m (50–100 yd) in width, provided
5713-598: A second postponement. 13 days prior to the opening match, the entire tournament was moved to Brazil due to a rise in COVID-19 cases in Argentina. The 2021 Copa América was played by 10 teams with no spectators at most matches due to the pandemic; the final at the Maracanã was limited to 10 percent of capacity. Argentina won their first title in 28 years by defeating Brazil in the final. CONMEBOL and CONCACAF signed
5910-424: A secondary bacterial infection occurs, then antibiotics may be necessary. Antiviral drugs are primarily used to treat severely ill patients, especially those with compromised immune systems. Antivirals are most effective when started in the first 48 hours after symptoms appear. Later administration may still be beneficial for those who have underlying immune defects, those with more severe symptoms, or those who have
6107-576: A similar ancient game ( cuju , or tsu chu ) was played by women during the Han dynasty (25–220 CE), as female figures are depicted in frescoes of the period playing tsu chu . There are also reports of annual football matches played by women in Midlothian , Scotland, during the 1790s. Association football, the modern game, has documented early involvement of women. In 1863, football governing bodies introduced standardised rules to prohibit violence on
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6304-532: A simple way of obtaining assay results, are low cost, and produce results in less than 30 minutes, so they are commonly used, but they can not distinguish between influenza A virus and influenza B virus or between influenza A virus subtypes and are not as sensitive as nucleic-acid based tests. Nucleic acid-based tests (NATs) amplify and detect viral nucleic acid. Most of these tests take a few hours, but rapid molecular assays are as fast as RIDTs. Among NATs, reverse transcription polymerase chain reaction (RT-PCR)
6501-615: A surprisingly strong Chilean squad who made it to the final, disposing of the powerful Brazil 4–0 on the group stage. Brazil lifted its first official international title since the 1970 FIFA World Cup upon winning the 1989 Copa América held on home soil. Argentina, in turn, won the Copa América after 32 long years in 1991 in Chile, thanks to a refreshed squad led by the prolific goalscorer Gabriel Batistuta . The 1993 Copa América tournament in Ecuador would take its current form. Along with
6698-527: A total match time of 90 minutes. With an estimated 250 million players active in over 200 countries and territories, it is the world's most popular sport. The game of association football is played in accordance with the Laws of the Game , a set of rules that has been in effect since 1863 and maintained by the IFAB since 1886. The game is played with a football that is 68–70 cm (27–28 in) in circumference . The two teams compete to score goals by getting
6895-448: A transcriptase, PB2, which recognizes 5' caps , and PA (P3 for influenza C virus and influenza D virus), an endonuclease . The M1 matrix protein and M2 proton channel share a segment, as do the non-structural protein (NS1) and the nuclear export protein (NEP). For influenza A virus and influenza B virus, hemagglutinin (HA) and neuraminidase (NA) are encoded on one segment each, whereas influenza C virus and influenza D virus encode
7092-564: A truce to the nation's civil war in 2006 and it helped further reduce tensions between government and rebel forces in 2007 by playing a match in the rebel capital of Bouaké , an occasion that brought both armies together peacefully for the first time. By contrast, football is widely considered to have been the final proximate cause for the Football War in June 1969 between El Salvador and Honduras . The sport also exacerbated tensions at
7289-476: A type of white blood cell, produce antibodies that bind to influenza antigens HA and NA (or HEF ) and other proteins to a lesser degree. Once bound to these proteins, antibodies block virions from binding to cellular receptors, neutralizing the virus. In humans, a sizeable antibody response occurs about one week after viral exposure. This antibody response is typically robust and long-lasting, especially for influenza C virus and influenza D virus. People exposed to
7486-550: A type-1 hemagglutinin (H) protein and a type-1 neuraminidase (N) protein. Almost all possible combinations of H (1 thru 16) and N (1 thru 11) have been isolated from wild birds. In addition H17, H18, N10 and N11 have been found in bats. The influenza A virus subtypes in circulation among humans as of 2018 are H1N1 and H3N2. Influenza B virus mainly infects humans but has been identified in seals, horses, dogs, and pigs. Influenza B virus does not have subtypes like influenza A virus but has two antigenically distinct lineages, termed
7683-432: A variety of positions in which the outfield (non-goalkeeper) players are strategically placed by a coach, these positions are not defined or required by the Laws. The basic equipment or kit players are required to wear includes a shirt, shorts, socks, footwear and adequate shin guards . An athletic supporter and protective cup is highly recommended for male players by medical experts and professionals. Headgear
7880-425: A virion, is pleomorphic and varies between being filamentous, bacilliform, or spherical in shape. Clinical isolates tend to be pleomorphic, whereas strains adapted to laboratory growth typically produce spherical virions. Filamentous virions are about 250 nanometers (nm) by 80 nm, bacilliform 120–250 by 95 nm, and spherical 120 nm in diameter. The core of the virion comprises one copy of each segment of
8077-400: A year, once for each hemisphere, to discuss which strains should be included based on observation from HA inhibition assays. Other manufacturing methods include an MDCK cell culture-based inactivated vaccine and a recombinant subunit vaccine manufactured from baculovirus overexpression in insect cells. Influenza can be prevented or reduced in severity by post-exposure prophylaxis with
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8274-415: Is a team sport played between two teams of 11 players each, who almost exclusively use their feet to propel a ball around a rectangular field called a pitch . The objective of the game is to score more goals than the opposing team by moving the ball beyond the goal line into a rectangular-framed goal defended by the opposing team. Traditionally, the game has been played over two 45-minute halves, for
8471-465: Is a sudden, drastic change in an influenza virus' antigen, usually HA. During antigenic shift, antigenically different strains that infect the same cell can reassort genome segments with each other, producing hybrid progeny. Since all influenza viruses have segmented genomes, all are capable of reassortment. Antigenic shift only occurs among influenza viruses of the same genus and most commonly occurs among influenza A viruses. In particular, reassortment
8668-468: Is acidified by cellular vATPase to have lower pH, which triggers a conformational change in HA that allows fusion of the viral envelope with the endosomal membrane. At the same time, hydrogen ions diffuse into the virion through M2 ion channels, disrupting internal protein-protein interactions to release RNPs into the host cell's cytosol . The M1 protein shell surrounding RNPs is degraded, fully uncoating RNPs in
8865-763: Is characterized by high levels of viral replication in the lower respiratory tract, accompanied by a strong pro-inflammatory response called a cytokine storm . Infection with H5N1 or H7N9 especially produces high levels of pro-inflammatory cytokines. In bacterial infections, early depletion of macrophages during influenza creates a favorable environment in the lungs for bacterial growth since these white blood cells are important in responding to bacterial infection. Host mechanisms to encourage tissue repair may inadvertently allow bacterial infection. Infection also induces production of systemic glucocorticoids that can reduce inflammation to preserve tissue integrity but allow increased bacterial growth. The pathophysiology of influenza
9062-419: Is dependent on vaccination with biosecurity. Diagnosis based on symptoms is fairly accurate in otherwise healthy people during seasonal epidemics and should be suspected in cases of pneumonia, acute respiratory distress syndrome (ARDS), sepsis , or if encephalitis, myocarditis , or breakdown of muscle tissue occur. Because influenza is similar to other viral respiratory tract illnesses, laboratory diagnosis
9259-409: Is determined as follows: If two or more teams are equal on the basis of the above three criteria, their rankings are determined as follows: The knockout stage is a single-elimination tournament in which teams play each other in one-off matches, with penalty shootouts used to decide the winner if a match is still tied after 90 minutes in the quarter-finals and semi-finals, and after extra time in
9456-436: Is diagnosed with laboratory methods such as antibody or antigen tests and a polymerase chain reaction ( PCR ) to identify viral nucleic acid . The disease can be treated with supportive measures and, in severe cases, with antiviral drugs such as oseltamivir . In healthy individuals, influenza is typically self-limiting and rarely fatal, but it can be deadly in high-risk groups. In a typical year, five to 15 percent of
9653-477: Is distantly related to influenza C virus. While cattle workers have occasionally tested positive to prior influenza D virus infection, it is not known to cause disease in humans. Influenza C virus and influenza D virus experience a slower rate of antigenic evolution than influenza A virus and influenza B virus. Because of this antigenic stability, relatively few novel lineages emerge. Every year, millions of influenza virus samples are analysed to monitor changes in
9850-425: Is exported out of the nucleus and translated by host ribosomes in a cap-dependent manner to synthesize viral proteins. RdRp also synthesizes complementary positive-sense strands of the viral genome in a complementary RNP complex which are then used as templates by viral polymerases to synthesize copies of the negative-sense genome. During these processes, RdRps of avian influenza viruses (AIVs) function optimally at
10047-468: Is governed by FIFA . Under FIFA, there are six continental confederations: AFC , CAF , CONCACAF , CONMEBOL , OFC , and UEFA . Of these confederations, CONMEBOL is the oldest one, being founded in 1916. National associations (e.g. The FA in England) are responsible for managing the game in their own countries both professionally and at an amateur level, and coordinating competitions in accordance with
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#173277220245710244-427: Is in the area about two meters around an infected person via respiratory droplets that come into contact with mucosa of the upper respiratory tract. Transmission through contact with a person, bodily fluids, or intermediate objects ( fomites ) can also occur, since influenza viruses can survive for hours on non-porous surfaces. If one's hands are contaminated, then touching one's face can cause infection. Influenza
10441-506: Is intracellular and performed by ubiquitous proteases, which allows for infection of a greater variety of cells, thereby contributing to more severe disease. Cells possess sensors to detect viral RNA, which can then induce interferon production. Interferons mediate expression of antiviral proteins and proteins that recruit immune cells to the infection site, and they notify nearby uninfected cells of infection. Some infected cells release pro-inflammatory cytokines that recruit immune cells to
10638-410: Is marked by the goal line, two lines starting on the goal line 16.5 m (18 yd) from the goalposts and extending 16.5 m (18 yd) into the pitch perpendicular to the goal line, and a line joining them. This area has a number of functions, the most prominent being to mark where the goalkeeper may handle the ball and where a penalty foul by a member of the defending team becomes punishable by
10835-614: Is necessary for confirmation. Common sample collection methods for testing include nasal and throat swabs. Samples may be taken from the lower respiratory tract if infection has cleared the upper but not lower respiratory tract. Influenza testing is recommended for anyone hospitalized with symptoms resembling influenza during flu season or who is connected to an influenza case. For severe cases, earlier diagnosis improves patient outcome. Diagnostic methods that can identify influenza include viral cultures , antibody- and antigen-detecting tests, and nucleic acid-based tests. Viruses can be grown in
11032-438: Is not a required piece of basic equipment, but players today may choose to wear it to protect themselves from head injury. Players are forbidden to wear or use anything that is dangerous to themselves or another player, such as jewellery or watches. The goalkeeper must wear clothing that is easily distinguishable from that worn by the other players and the match officials. A number of players may be replaced by substitutes during
11229-734: Is not known to cause illness. In humans, influenza viruses are primarily transmitted through respiratory droplets from coughing and sneezing. Transmission through aerosols and surfaces contaminated by the virus also occur. Frequent hand washing and covering one's mouth and nose when coughing and sneezing reduce transmission, as does wearing a mask. Annual vaccination can help to provide protection against influenza. Influenza viruses, particularly influenza A virus, evolve quickly, so flu vaccines are updated regularly to match which influenza strains are in circulation. Vaccines provide protection against influenza A virus subtypes H1N1 and H3N2 and one or two influenza B virus subtypes. Influenza infection
11426-405: Is positioned on each goal line, midway between the two touchlines. The inner edges of the vertical goal posts must be 7.32 m (24 ft) apart, and the lower edge of the horizontal crossbar supported by the goal posts must be 2.44 m (8 ft) above the ground. Nets are usually placed behind the goal, but are not required by the Laws. In front of the goal is the penalty area. This area
11623-816: Is quite unsuitable for females and should not be encouraged." Players and football writers have argued that this ban was, in fact, due to envy of the large crowds that women's matches attracted, and because the FA had no control over the money made from the women's game. The FA ban led to the formation of the short-lived English Ladies Football Association and play moved to rugby grounds. Women's football also faced bans in several other countries , notably in Brazil from 1941 to 1979, in France from 1941 to 1970, and in Germany from 1955 to 1970. Restrictions began to be reduced in
11820-506: Is recognisable as modern football. As with pre-codified mob football , the antecedent of all modern football codes , these three games involved more handling the ball than kicking it. Association football in itself does not have a classical history. Notwithstanding any similarities to other ball games played around the world, FIFA has described that no historical connection exists with any game played in antiquity outside Europe. The history of football in England dates back to at least
12017-544: Is recommended for people who have yet to receive a vaccine for the current flu season, who have been vaccinated less than two week since contact, if there is a significant mismatch between vaccine and circulating strains, or during an outbreak in a closed setting regardless of vaccination history. These are the main ways that influenza spreads When vaccines and antiviral medications are limited, non-pharmaceutical interventions are essential to reduce transmission and spread. The lack of controlled studies and rigorous evidence of
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#173277220245712214-413: Is recommended to avoid alcohol and tobacco use while ill. Aspirin is not recommended to treat influenza in children due to an elevated risk of developing Reye syndrome . Corticosteroids are not recommended except when treating septic shock or an underlying medical condition, such as chronic obstructive pulmonary disease or asthma exacerbation, since they are associated with increased mortality. If
12411-764: Is removed and facilities are disinfected and "no carry-over" policies to eliminate infectious material before new poultry arrive can be used to reduce the spread of influenza viruses. If a novel influenza viruses has breached the aforementioned biosecurity measures, then rapid detection to stamp it out via quarantining, decontamination, and culling may be necessary to prevent the virus from becoming endemic. Vaccines exist for avian H5, H7, and H9 subtypes that are used in some countries. In China, for example, vaccination of domestic birds against H7N9 successfully limited its spread, indicating that vaccination may be an effective strategy if used in combination with other measures to limit transmission. In pigs and horses, management of influenza
12608-464: Is significantly influenced by which receptors influenza viruses bind to during entry into cells. Mammalian influenza viruses preferentially bind to sialic acids connected to the rest of the oligosaccharide by an α-2,6 link, most commonly found in various respiratory cells, such as respiratory and retinal epithelial cells. AIVs prefer sialic acids with an α-2,3 linkage, which are most common in birds in gastrointestinal epithelial cells and in humans in
12805-566: Is simpler. Examples are B/Santiago/29615/2020 and C/Minnesota/10/2015. Influenza viruses have a negative-sense , single-stranded RNA genome that is segmented. The negative sense of the genome means it can be used as a template to synthesize messenger RNA (mRNA). Influenza A virus and influenza B virus have eight genome segments that encode 10 major proteins. Influenza C virus and influenza D virus have seven genome segments that encode nine major proteins. Three segments encode three subunits of an RNA-dependent RNA polymerase (RdRp) complex: PB1,
13002-516: Is slower in B than A and slowest in C and D. Antigenic drift is a major cause of seasonal influenza, and requires that flu vaccines be updated annually. HA is the main component of inactivated vaccines, so surveillance monitors antigenic drift of this antigen among circulating strains. Antigenic evolution of influenza viruses of humans appears to be faster than in swine and equines. In wild birds, within-subtype antigenic variation appears to be limited but has been observed in poultry. Antigenic shift
13199-593: Is the dominant region in women's football, with the United States winning the most FIFA Women's World Cups and Olympic tournaments. Europe and Asia come second and third in terms of international success, and the women's game has been improving in South America. Association football is played in accordance with a set of rules known as the Laws of the Game . The game is played using a spherical ball of 68–70 cm (27–28 in) circumference, known as
13396-461: Is the most traditional and considered the gold standard for diagnosing influenza because it is fast and can subtype influenza A virus, but it is relatively expensive and more prone to false-positives than cultures. Other NATs that have been used include loop-mediated isothermal amplification -based assays, simple amplification-based assays, and nucleic acid sequence-based amplification. Nucleic acid sequencing methods can identify infection by obtaining
13593-455: Is the official timekeeper for the match, and may make an allowance for time lost through substitutions, injured players requiring attention, or other stoppages. This added time is called "additional time" in FIFA documents, but is most commonly referred to as stoppage time or injury time , while lost time can also be used as a synonym. The duration of stoppage time is at the sole discretion of
13790-435: Is thought to have been borrowed from the slang of Rugby School . Initially spelt assoccer (a shortening of "association"), it was later reduced to the modern spelling. This form of slang also gave rise to rugger for rugby football, fiver and tenner for five pound and ten pound notes , and the now-archaic footer that was also a name for association football. The word soccer arrived at its current form in 1895 and
13987-404: Is to score goals; defenders , who specialise in preventing their opponents from scoring; and midfielders , who dispossess the opposition and keep possession of the ball to pass it to the forwards on their team. Players in these positions are referred to as outfield players, to distinguish them from the goalkeeper. These positions are further subdivided according to the area of the field in which
14184-407: Is usually transmissible from one day before the onset of symptoms to 5–7 days after. In healthy adults, the virus is shed for up to 3–5 days. In children and the immunocompromised, the virus may be transmissible for several weeks. Children ages 2–17 are considered to be the primary and most efficient spreaders of influenza. Children who have not had multiple prior exposures to influenza viruses shed
14381-501: Is very common in AIVs, creating a large diversity of influenza viruses in birds, but is uncommon in human, equine, and canine lineages. Pigs, bats, and quails have receptors for both mammalian and avian influenza A viruses, so they are potential "mixing vessels" for reassortment. If an animal strain reassorts with a human strain, then a novel strain can emerge that is capable of human-to-human transmission. This has caused pandemics, but only
14578-519: Is when an influenza virus' antigens change due to the gradual accumulation of mutations in the antigen's (HA or NA) gene. This can occur in response to evolutionary pressure exerted by the host immune response. Antigenic drift is especially common for the HA protein, in which just a few amino acid changes in the head region can constitute antigenic drift. The result is the production of novel strains that can evade pre-existing antibody-mediated immunity. Antigenic drift occurs in all influenza species but
14775-421: The football (or soccer ball ). Two teams of eleven players each compete to get the ball into the other team's goal (between the posts and under the bar), thereby scoring a goal. The team that has scored more goals at the end of the game is the winner; if both teams have scored an equal number of goals then the game is a draw. Each team is led by a captain who has only one official responsibility as mandated by
14972-607: The 1928 final at the 1928 Summer Olympics held in Amsterdam , Argentina would gain revenge in the 1929 South American Championship by defeating the Uruguayans in the last, decisive match. During this period, both Bolivia and Peru debuted in the tournament in 1926 and 1927 , respectively. After the first World Cup held in Uruguay in 1930, the enmity between the football federations of Uruguay and Argentina prevented
15169-413: The 2001 edition due to scheduling and security disagreements. Owing to this somewhat limited number of available participants, countries from other continents have usually been invited to make up the 12 teams necessary for the current tournament format since 1993. Most often those have been from CONCACAF , whose members are geographically and culturally close. For the centennial edition in 2016 and for
15366-556: The 2014 FIFA World Cup and 2016 Summer Olympics . Chile went on to win the tournament, their first title, on home soil. In 2016, the centenary of the tournament was celebrated with the Copa América Centenario tournament hosted in the United States; the tournament was the first to be hosted outside of South America and had an expanded field of 16 teams from CONMEBOL and CONCACAF. During the tournament, media outlets reported that CONMEBOL and CONCACAF were negotiating
15563-535: The 2020 Copa América to move in line with the UEFA European Championship , which would be jointly hosted by Argentina and Colombia and split into two groups. The tournament was postponed by a year due to the COVID-19 pandemic and lost two invited teams from Asia— Australia and Qatar —due to fixture congestion. Colombia requested that the tournament be moved to November 2021 due to widespread protests and increased COVID-19 cases, but withdrew after CONMEBOL rejected
15760-527: The Caribbean and Oceania regions (except Australia ) have yet to make a mark in international football. When it comes to men's national teams, Europeans and South Americans continue to dominate the FIFA World Cup, as no team from any other region has managed to even reach the final. These regional trends do not hold true for the women's game, as the United States women's national team has won
15957-471: The upper respiratory tract , but progression to pneumonia is relatively common. Pneumonia may be caused by the primary viral infection or a secondary bacterial infection . Primary pneumonia is characterized by rapid progression of fever, cough, labored breathing , and low oxygen levels that cause bluish skin . It is especially common among those who have an underlying cardiovascular disease such as rheumatic heart disease . Secondary pneumonia typically has
16154-534: The 12-team roster, and 2019 , which featured Japan and Qatar . The 2016 and 2024 tournaments both featured 16 teams, with six teams from CONCACAF in addition to the 10 from CONMEBOL. The first football team in South America, Lima Cricket and Football Club , was established in Peru in 1859, and the Argentine Football Association was founded in 1893. By the early 20th century, football
16351-635: The 1960s and 1970s. The Italian women's football league was established in 1968. In December 1969, the Women's Football Association was formed in England, with the sport eventually becoming the most prominent team sport for women in the United Kingdom. Two unofficial women's World Cups were organised by the FIEFF in 1970 and in 1971 . Also in 1971, UEFA members voted to officially recognise women's football, while The Football Association rescinded
16548-405: The 1990s, teams from North America and Asia have also been invited to compete. Eight of the ten CONMEBOL national teams have won the tournament at least once in its 48 stagings since the event's inauguration in 1916, with Ecuador and Venezuela the only teams yet to win. Argentina have the most championships in the tournament's history, with 16 cups. The country that hosted the tournament
16745-715: The Argentine Football Association, that it would host the 2011 Copa América . The 2015 Copa América was due to be held in Brazil following the order of rotation. However, as Brazil was hosting both the 2014 FIFA World Cup and the 2016 Summer Olympics , the decision was reconsidered. Although CONMEBOL President Nicolas Leoz proposed hosting the continental tournament in Mexico (a member of the CONCACAF federation) and board members Brazil and Chile discussed
16942-569: The B/Victoria/2/1987-like and B/Yamagata/16/1988-like lineages, or simply (B/)Victoria(-like) and (B/)Yamagata(-like). Both lineages are in circulation in humans, disproportionately affecting children. However, the B/Yamagata lineage might have become extinct in 2020/2021 due to COVID-19 pandemic measures. Influenza B viruses contribute to seasonal epidemics alongside influenza A viruses but have never been associated with
17139-576: The FIFA Women's World Cup four times, more than any other women's team. Football is played at a professional level all over the world. Millions of people regularly go to football stadiums to follow their favourite teams, while billions more watch the game on television or on the internet. A very large number of people also play football at an amateur level. According to a survey conducted by FIFA published in 2001, over 240 million people from more than 200 countries regularly play football. Football has
17336-910: The Football Association, the Scottish Football Association , the Football Association of Wales , and the Irish Football Association . FIFA , the international football body, was formed in Paris in 1904 and declared that they would adhere to the Laws of the Game of the Football Association. The growing popularity of the international game led to the admittance of FIFA representatives to the IFAB in 1913. The board consists of four representatives from FIFA and one representative from each of
17533-467: The Game while the ball is in play. The offences that constitute a foul are listed in Law 12. Handling the ball deliberately, tripping an opponent, or pushing an opponent, are examples of "penal fouls", punishable by a direct free kick or penalty kick depending on where the offence occurred. Other fouls are punishable by an indirect free kick . The referee may punish a player's or substitute's misconduct by
17730-475: The IFAB Laws. Each team consists of a maximum of eleven players (excluding substitutes ), one of whom must be the goalkeeper . Competition rules may state a minimum number of players required to constitute a team, which is usually seven. Goalkeepers are the only players allowed to play the ball with their hands or arms, provided they do so within the penalty area in front of their own goal. Though there are
17927-430: The Laws of the Game in connection with the match to which he has been appointed" (Law 5), and whose decisions are final. The referee is assisted by two assistant referees . In many high-level games there is also a fourth official who assists the referee and may replace another official should the need arise. Goal line technology is used to measure if the whole ball has crossed the goal-line thereby determining whether
18124-748: The Laws of the Game. The most prestigious senior international competitions are the FIFA World Cup and the FIFA Women's World Cup . The men's World Cup is the most-viewed sporting event in the world, surpassing the Olympic Games . The two most prestigious competitions in club football are the UEFA Champions League and the UEFA Women's Champions League , which attract an extensive television audience worldwide. The final of
18321-479: The Laws of the Game: to represent their team in the coin toss before kick-off or penalty kicks . The primary law is that players other than goalkeepers may not deliberately handle the ball with their hands or arms during play, though they must use both their hands during a throw-in restart. Although players usually use their feet to move the ball around, they may use any part of their body (notably, "heading" with
18518-597: The South American pantheon after defeating Argentina, on penalties, in order to win the 2004 competition held in Peru. Three years later , the two teams met again in the final, this time in Venezuela. Once again, Brazil came out victorious after crushing Argentina 3–0. Argentina hosted the 2011 competition and was ousted by Uruguay in the quarterfinals by penalty shootout. Uruguay would go on defeating Peru 2–0 in
18715-480: The United States. A notable exception is New Zealand, where in the first two decades of the 21st century, under the influence of international television, "football" has been gaining prevalence, despite the dominance of other codes of football, namely rugby union and rugby league . The term soccer comes from Oxford "-er" slang, which was prevalent at the University of Oxford in England from about 1875, and
18912-409: The air. A person susceptible to infection can contract influenza by coming into contact with these particles. Respiratory droplets are relatively large and travel less than two meters before falling onto nearby surfaces. Aerosols are smaller and remain suspended in the air longer, so they take longer to settle and can travel further. Inhalation of aerosols can lead to infection, but most transmission
19109-465: The airways, loss of alveolar structure, loss of lung epithelial integrity due to epithelial cell infection and death, and degradation of the extracellular matrix that maintains lung structure. In particular, alveolar cell infection appears to drive severe symptoms since this results in impaired gas exchange and enables viruses to infect endothelial cells, which produce large quantities of pro-inflammatory cytokines . Pneumonia caused by influenza viruses
19306-463: The antiviral drugs oseltamivir , which can be taken orally by those at least three months old, and zanamivir , which can be inhaled by those above seven years. Chemoprophylaxis is most useful for individuals at high risk for complications and those who cannot receive the flu vaccine. Post-exposure chemoprophylaxis is only recommended if oseltamivir is taken within 48 hours of contact with a confirmed or suspected case and zanamivir within 36 hours. It
19503-452: The ball into the other team's goal (between the posts, under the bar, and fully across the goal line). When the ball is in play, the players mainly use their feet, but may also use any other part of their body, such as their head, chest and thighs, except for their hands or arms, to control, strike, or pass the ball. Only the goalkeepers may use their hands and arms, and that only within the penalty area . The team that has scored more goals at
19700-460: The ban that prohibited women from playing on association members' pitches in England. Women's football still faces many struggles, but its worldwide growth has seen major competitions being launched at both the national and international levels, mirroring the men's competitions. The FIFA Women's World Cup was inaugurated in 1991: the first tournament was held in China, featuring 12 teams from
19897-410: The beginning of each playing period with a kick-off until the end of the playing period, the ball is in play at all times, except when either the ball leaves the field of play, or play is stopped by the referee. When the ball becomes out of play, play is restarted by one of eight restart methods depending on how it went out of play: A foul occurs when a player commits an offence listed in the Laws of
20094-534: The beginning of the Croatian War of Independence of the 1990s, when a match between Dinamo Zagreb and Red Star Belgrade degenerated into rioting in May 1990. Women's association football has historically seen opposition, with national associations severely curbing its development and several outlawing it completely. Women may have been playing football for as long as the game has existed. Evidence shows that
20291-441: The biggest surprises of the history of the sport as Honduras eliminated Brazil in the quarterfinals. Colombia, the host nation, would go on to win the competition for the first time ever. From 2001 to 2007, the tournament was contested every three years, and from 2007 forward every four years, with the exception of the tournament's centennial in 2016. Running from an embarrassing performance in 2001, Brazil reestablished itself in
20488-404: The buildup, direct red card decisions, and penalty decisions. The ball is spherical with a circumference of between 68 and 70 cm (27 and 28 in), a weight in the range of 410 to 450 g (14 to 16 oz), and a pressure between 0.6 and 1.1 standard atmospheres (8.5 and 15.6 pounds per square inch ) at sea level. In the past the ball was made up of leather panels sewn together, with
20685-500: The capacity of the newly built Estadio Nacional was expanded from 30,000 to 70,000 spectators. Despite the large investment and initial success of the team, the Chileans would be defeated in the last match by eventual champions Argentina. Uruguay hosted and won the 1942 edition . Chile would host again in 1945 , and came close to playing for the title against Argentina. However, Brazil spoiled that possibility, and Argentina would win
20882-436: The champion. Between 1975 and 1983 it had no fixed host nation, and was held in a home and away fashion. The current final tournament features 12 national teams competing over a month in the host nation. There are two phases: the group stage followed by the knockout stage. In the group stage, teams compete within three groups of four teams each. Three teams are seeded, including the hosts, with the other seeded teams selected using
21079-750: The champions of these two club competitions would contest the Intercontinental Cup to prove which team was the best in the world. In the 21st century, South America has continued to produce some of the best footballers in the world, but its clubs have fallen behind the still dominant European clubs, which often sign the best players from Latin America and elsewhere. Meanwhile, football has improved in Africa , Asia and North America , and nowadays, these regions are at least on equal grounds with South America in club football, although countries in
21276-435: The competition from being played for a number of years. Only in 1935 was it possible to dispute a special edition of the event to be officially reinstated in 1939 . Peru became the host nation of the 1939 edition and won the competition for the first time. Ecuador made their debut at that tournament. In 1941, Chile hosted that year's edition in celebration of the 400th anniversary of the founding of Santiago for which
21473-537: The competition returned to being held every two years, then three and later four. There were even two tournaments held in 1959, one in Argentina and a second in Ecuador . During this period, some of the national teams were indifferent to the tournament. Some did not participate every year, others sent lesser teams; in the 1959 edition held in Ecuador, Brazil entered a team from the state of Pernambuco . Bolivia won for
21670-501: The competition, as well as the edition won. The trophy previously had a one- and two-level base , and prior to 1979 there was no base at all, like the one used in 1975 . In April 2016, a commemorative trophy – specifically designed for the Copa América Centenario – was introduced at the Colombian Football Federation headquarters of Bogotá to commemorate the 100th anniversary of the competition. The trophy
21867-425: The course of the game. The maximum number of substitutions permitted in most competitive international and domestic league games is five in 90 minutes, with each team being allowed one more if the game should go into extra-time; the permitted number may vary in other competitions or in friendly matches . Common reasons for a substitution include injury, tiredness, ineffectiveness, a tactical switch, or timewasting at
22064-427: The cytoplasmic side of the membrane. The viral genome is incorporated inside a viral envelope derived from portions of the cell membrane that have HA, NA, and M2 proteins. At the end of budding, HA proteins remain attached to cellular sialic acid until they are cleaved by the sialidase activity of NA proteins. The virion is then released from the cell. The sialidase activity of NA also cleaves any sialic acid residues from
22261-404: The cytosol. RNPs are then imported into the nucleus with the help of viral localization signals. There, the viral RNA polymerase transcribes mRNA using the genomic negative-sense strand as a template. The polymerase snatches 5' caps for viral mRNA from cellular RNA to prime mRNA synthesis and the 3'-end of mRNA is polyadenylated at the end of transcription. Once viral mRNA is transcribed, it
22458-530: The effectiveness of some measures has hampered planning decisions and recommendations. Nevertheless, strategies endorsed by experts for all phases of flu outbreaks include hand and respiratory hygiene, self-isolation by symptomatic individuals and the use of face masks by them and their caregivers, surface disinfection, rapid testing and diagnosis, and contact tracing . In some cases, other forms of social distancing including school closures and travel restrictions are recommended. Reasonably effective ways to reduce
22655-453: The eighth century. The modern rules of association football are based on the mid-19th century efforts to standardise the widely varying forms of football played in the public schools of England. The Cambridge rules , first drawn up at the University of Cambridge in 1848, were particularly influential in the development of subsequent codes, including association football. The Cambridge rules were written at Trinity College, Cambridge , at
22852-420: The end of a finely poised game. In standard adult matches, a player who has been substituted may not take further part in a match. IFAB recommends "that a match should not continue if there are fewer than seven players in either team". Any decision regarding points awarded for abandoned games is left to the individual football associations. A game is officiated by a referee , who has "full authority to enforce
23049-405: The end of the game is the winner. There are situations where a goal can be disallowed, such as an offside call or a foul in the build-up to the goal. Depending on the format of the competition, an equal number of goals scored may result in a draw being declared with 1 point awarded to each team, or the game goes into extra time or a penalty shoot-out . Internationally, association football
23246-442: The establishment of a confederation of the associations of Argentina, Brazil, Chile and Uruguay. On 9 July, independence day in Argentina, CONMEBOL was founded. The following year , the competition was played again, this time in Uruguay. Uruguay would win the title again to win their bicampeonato after defeating Argentina 1–0 in the last match of the tournament. The success of the tournament on Charrúan soil would help consolidate
23443-435: The final. It begins with the quarter-finals, then semi-finals, the third-place match (contested by the losing semi-finalists), and the final. All registered national federations of CONMEBOL, of which there currently are ten, are eligible for automatic berths in the tournament. Since the competition's rebranding in 1975, there has been only one occasion when one of those teams missed out on a tournament: Argentina withdrew from
23640-657: The first participants of the tournament. This so-called Campeonato Sudamericano de Football would be the first edition of what is currently known as Copa América; Uruguay would triumph in this first edition after tying 0–0 with hosts Argentina in the deciding, last match held in Estadio Racing Club in Avellaneda . Seeing the success of the tournament, a boardmember of the Uruguayan Football Association , Héctor Rivadavia , proposed
23837-474: The first time after its football association affiliated to CONMEBOL earlier that same year. Argentina won the competition for the first time thanks to the goals of Julio Libonatti . In subsequent years, Uruguay would dominate the tournament, which at that time was the largest football tournament in the world. Argentina, however, would not be far behind and disputed the supremacy with the Charruas . After losing
24034-494: The first time when it hosted in 1963 , but was defeated in the first game of the 1967 tournament by debutant Venezuela . The founding of the Copa Libertadores in 1959 also affected the way the tournament was viewed by its participants. After eight years of absence, the event resumed in 1975 and officially acquired the name Copa América . The tournament had no fixed venue, and all matches were played throughout
24231-519: The five continental titles between 1997 and 2007. The first, in 1997 , was won after defeating host nation Bolivia 1–3 with goals from Leonardo , Denílson and Ronaldo becoming crucial in the Verde-Amarela' s consecration on Bolivia 's altitude. Brazil would successfully defend the title in 1999 after thumping Uruguay 3–0 in Asuncion , Paraguay. However, the 2001 Copa América saw one of
24428-462: The flu are trivalent or quadrivalent, providing protection against an H1N1 strain, an H3N2 strain, and one or two influenza B virus strains corresponding to the two influenza B virus lineages. Two types of vaccines are in use: inactivated vaccines that contain "killed" (i.e. inactivated) viruses and live attenuated influenza vaccines (LAIVs) that contain weakened viruses. There are three types of inactivated vaccines: whole virus, split virus, in which
24625-420: The forehead) other than their hands or arms. Within normal play, all players are free to play the ball in any direction and move throughout the pitch, though players may not pass to teammates who are in an offside position. During gameplay, players attempt to create goal-scoring opportunities through individual control of the ball, such as by dribbling , passing the ball to a teammate, and by taking shots at
24822-528: The formation of a Sheffield FA in 1867. In 1862, John Charles Thring of Uppingham School also devised an influential set of rules. These ongoing efforts contributed to the formation of The Football Association (The FA) in 1863, which first met on the morning of 26 October 1863 at the Freemasons' Tavern in Great Queen Street , London. The only school to be represented on this occasion
25019-464: The four British associations. For most of the 20th century, Europe and South America were the dominant regions in association football. The FIFA World Cup , inaugurated in 1930 , became the main stage for players of both continents to show their worth and the strength of their national teams. In the second half of the century, the European Cup and the Copa Libertadores were created, and
25216-695: The game in a specific position, there are few restrictions on player movement, and players can switch positions at any time. The layout of a team's players is known as a formation . Defining the team's formation and tactics is usually the prerogative of the team's manager . There are 17 laws in the official Laws of the Game, each containing a collection of stipulations and guidelines. The same laws are designed to apply to all levels of football for both sexes, although certain modifications for groups such as juniors, seniors and people with physical disabilities are permitted. The laws are often framed in broad terms, which allow flexibility in their application depending on
25413-541: The genome bound to NP nucleoproteins in separate ribonucleoprotein (RNP) complexes for each segment. There is a copy of the RdRp, all subunits included, bound to each RNP. The genetic material is encapsulated by a layer of M1 matrix protein which provides structural reinforcement to the outer layer, the viral envelope . The envelope comprises a lipid bilayer membrane incorporating HA and NA (or HEF ) proteins extending outward from its exterior surface. HA and HEF proteins have
25610-425: The goal, which is guarded by the opposing goalkeeper. Opposing players may try to regain control of the ball by intercepting a pass or through tackling the opponent in possession of the ball; however, physical contact between opponents is restricted. Football is generally a free-flowing game, with play stopping only when the ball has left the field of play or when play is stopped by the referee for an infringement of
25807-404: The highest global television audience in sport. In many parts of the world, football evokes great passions and plays an important role in the life of individual fans , local communities, and even nations. Ryszard Kapuściński says that Europeans who are polite, modest, or humble fall easily into rage when playing or watching football games. The Ivory Coast national football team helped secure
26004-687: The instigation of Alcock. England is also home to the world's first football league , which was founded in Birmingham in 1888 by Aston Villa director William McGregor . The original format contained 12 clubs from the Midlands and Northern England . Laws of the Game are determined by the International Football Association Board (IFAB). The board was formed in 1886 after a meeting in Manchester of
26201-759: The lack of a crossbar, rules which made it remarkably similar to Victorian rules football being developed at that time in Australia. The Sheffield FA played by its own rules until the 1870s, with the FA absorbing some of its rules until there was little difference between the games. The world's oldest football competition is the FA Cup , which was founded by the footballer and cricketer Charles W. Alcock , and has been contested by English teams since 1872. The first official international football match also took place in 1872, between Scotland and England in Glasgow , again at
26398-660: The late 1800s, pandemic outbreaks of novel influenza strains have occurred every 10 to 50 years. Five flu pandemics have occurred since 1900: the Spanish flu from 1918 to 1920, which was the most severe; the Asian flu in 1957; the Hong Kong flu in 1968; the Russian flu in 1977; and the swine flu pandemic in 2009. The symptoms of influenza are similar to those of a cold, although usually more severe and less likely to include
26595-400: The lower respiratory tract. Cleavage of the HA protein into HA 1 , the binding subunit, and HA 2 , the fusion subunit, is performed by different proteases, affecting which cells can be infected. For mammalian influenza viruses and low pathogenic AIVs, cleavage is extracellular, which limits infection to cells that have the appropriate proteases, whereas for highly pathogenic AIVs, cleavage
26792-614: The men's tournament is the most-watched annual sporting event in the world. Association football is one of a family of football codes that emerged from various ball games played worldwide since antiquity. Within the English-speaking world, the sport is now usually called "football" in Great Britain and most of Ulster in the north of Ireland, whereas people usually call it "soccer" in regions and countries where other codes of football are prevalent, such as Australia, Canada, South Africa, most of Ireland (excluding Ulster), and
26989-621: The most times (nine editions) is Argentina, including the inaugural edition in 1916. The United States is the only non-CONMEBOL country that hosted the event, having done so in both 2016 and 2024 . On three occasions (in 1975 , 1979 , and 1983 ), the tournament was held in multiple South American countries. Since 1993, the tournament has generally featured 12 teams — all 10 CONMEBOL teams and two additional teams from other confederations. Mexico participated in every tournament between 1993 and 2016, with one additional team drawn from CONCACAF , except for 1999 , when AFC team Japan filled out
27186-428: The nation had hosted an edition in 28 years. Despite entering as heavy favorites for being the reigning world champions (having won the 1986 FIFA World Cup ), playing at home and having a team largely composed of its World Cup winners led by the legendary Diego Maradona , Argentina would finish in a disappointing fourth place after being beaten by defending champions Uruguay 0–1 in the semifinals. Uruguay would defeat
27383-534: The nature of the game. The Laws of the Game are published by FIFA, but are maintained by the IFAB. In addition to the seventeen laws, numerous IFAB decisions and other directives contribute to the regulation of association football. Within the United States, Major League Soccer used a distinct ruleset during the 1990s and the National Federation of State High School Associations and NCAA still use rulesets that are comparable to, but different from,
27580-591: The next stoppage of play. The referee's decision in all on-pitch matters is considered final. The score of a match cannot be altered after the game, even if later evidence shows that decisions (including awards/non-awards of goals) were incorrect. Influenza Influenza , commonly known as the flu , is an infectious disease caused by influenza viruses . Symptoms range from mild to severe and often include fever , runny nose , sore throat , muscle pain , headache , coughing , and fatigue . These symptoms begin one to four (typically two) days after exposure to
27777-520: The nucleic acid sequence of viral samples to identify the virus and antiviral drug resistance. The traditional method is Sanger sequencing , but it has been largely replaced by next-generation methods that have greater sequencing speed and throughput. Treatment in cases of mild or moderate illness is supportive and includes anti-fever medications such as acetaminophen and ibuprofen , adequate fluid intake to avoid dehydration, and rest. Cough drops and throat sprays may be beneficial for sore throat. It
27974-414: The nucleus longer. M1 and NEP proteins localize to the nucleus during the later stages of infection, bind to viral RNPs and mediate their export to the cytoplasm where they migrate to the cell membrane with the aid of recycled endosomes and are bundled into the segments of the genome. Progeny viruses leave the cell by budding from the cell membrane, which is initiated by the accumulation of M1 proteins at
28171-426: The offences that constitute misconduct are listed, the definitions are broad. In particular, the offence of "unsporting behaviour" may be used to deal with most events that violate the spirit of the game, even if they are not listed as specific offences. A referee can show a yellow or red card to a player, substitute, substituted player, and to non-players such as managers and support staff. Rather than stopping play,
28368-574: The one in 2024 , reflecting the number of teams being increased to 16, qualification stages were held for the CONCACAF teams. In all, ten non-South American nations have participated in Copa América at least once: CONCACAF members Canada , Costa Rica , Haiti , Honduras , Jamaica , Mexico , Panama , and the United States , as well as AFC members Japan and Qatar . Two other teams, China and Australia , had accepted invitations respectively for 2015 and 2021, but both did not end up appearing because of clashes with other commitments. Moreover, Spain
28565-470: The original thirteen laws of the game. The sticking point was hacking, which a twelfth club at the meeting, Blackheath FC , had wanted to keep, resulting in them withdrawing from the FA. Other English rugby clubs followed this lead and did not join the FA, and instead in 1871, along with Blackheath, formed the Rugby Football Union . The FA rules included handling of the ball by "marks" and
28762-432: The pitch does not become square. In 2008, the IFAB initially approved a fixed size of 105 m (115 yd) long and 68 m (74 yd) wide as a standard pitch dimension for international matches; however, this decision was later put on hold and was never actually implemented. The longer boundary lines are touchlines , while the shorter boundaries (on which the goals are placed) are goal lines . A rectangular goal
28959-437: The pitch, making it more socially acceptable for women to play. The first match recorded by the Scottish Football Association took place in 1892 in Glasgow . In England, the first recorded game of football between women took place in 1895. Women's football has traditionally been associated with charity games and physical exercise, particularly in the United Kingdom. Association football continued to be played by women since
29156-437: The player spends the most time. For example, there are central defenders and left and right midfielders. The ten outfield players may be arranged in any combination. The number of players in each position determines the style of the team's play; more forwards and fewer defenders creates a more aggressive and offensive-minded game, while the reverse creates a slower, more defensive style of play. While players typically spend most of
29353-400: The players and spectators by holding up a board showing this number. The signalled stoppage time may be further extended by the referee. Added time was introduced because of an incident which happened in 1891 during a match between Stoke and Aston Villa . Trailing 1–0 with two minutes remaining, Stoke were awarded a penalty kick. Villa's goalkeeper deliberately kicked the ball out of play; by
29550-418: The population contracts influenza. There are 3 to 5 million severe cases annually, with up to 650,000 respiratory-related deaths globally each year. Deaths most commonly occur in high-risk groups, including young children, the elderly, and people with chronic health conditions. In temperate regions , the number of influenza cases peaks during winter, whereas in the tropics , influenza can occur year-round. Since
29747-611: The possibility of exchanging the 2015 and 2019 tournaments, it was decided and confirmed by the CBF in February 2011 that the 2015 Copa América would remain in Brazil. However, in March 2012, CBF president Ricardo Teixeira resigned from his position and the CBF agreed to swap the tournament's hosting with Chile. The swap was made official in May 2012. The centennial edition of the tournament, Copa América Centenario , took place in June 2016, and
29944-695: The primary measures used. Placing poultry houses and piggeries on high ground away from high-density farms, backyard farms, live poultry markets, and bodies of water helps to minimize contact with wild birds. Closure of live poultry markets appears to the most effective measure and has shown to be effective at controlling the spread of H5N1, H7N9, and H9N2 . Other biosecurity measures include cleaning and disinfecting facilities and vehicles, banning visits to poultry farms, not bringing birds intended for slaughter back to farms, changing clothes, disinfecting foot baths, and treating food and water. If live poultry markets are not closed, then "clean days" when unsold poultry
30141-420: The primary reservoir of influenza A virus, especially aquatic birds such as ducks, geese, shorebirds, and gulls, but the virus also circulates among mammals, including pigs, horses, and marine mammals. Subtypes of Influenza A are defined by the combination of the antigenic viral proteins haemagglutinin (H) and neuraminidase (N) in the viral envelope ; for example, " H1N1 " designates an IAV subtype that has
30338-462: The primary source of influenza A virus (IAV), which is also widespread in various mammals, including humans and pigs. Influenza B virus (IBV) and influenza C virus (ICV) primarily infect humans, and influenza D virus (IDV) is found in cattle and pigs. Influenza A virus and influenza B virus circulate in humans and cause seasonal epidemics , and influenza C virus causes a mild infection, primarily in children. Influenza D virus can infect humans but
30535-449: The probability of reassortment. In general, influenza vaccines are only effective if there is an antigenic match between vaccine strains and circulating strains. Most commercially available flu vaccines are manufactured by propagation of influenza viruses in embryonated chicken eggs, taking 6–8 months. Flu seasons are different in the northern and southern hemisphere, so the WHO meets twice
30732-416: The referee may allow play to continue if doing so will benefit the team against which an offence has been committed. This is known as "playing an advantage". The referee may "call back" play and penalise the original offence if the anticipated advantage does not ensue within "a few seconds". Even if an offence is not penalised due to advantage being played, the offender may still be sanctioned for misconduct at
30929-419: The referee. Stoppage time does not fully compensate for the time in which the ball is out of play , and a 90-minute game typically involves about an hour of "effective playing time". The referee alone signals the end of the match. In matches where a fourth official is appointed, towards the end of the half, the referee signals how many minutes of stoppage time they intend to add. The fourth official then informs
31126-440: The respective six confederations. The World Cup has been held every four years since; by 2019 , it had expanded to 24 national teams, and 1.12 billion viewers watched the competition. Four years later , FIFA targeted the 32-team 2023 Women's World Cup at an audience of 2 billion, while about 1.4 million tickets were sold, setting a Women's World Cup record. Women's football has been an Olympic event since 1996 . North America
31323-402: The result of lung inflammation and compromise caused by epithelial cell infection and death, combined with inflammation caused by the immune system's response to infection. Non-respiratory organs can become involved, but the mechanisms by which influenza is involved in these cases are unknown. Severe respiratory illness can be caused by multiple, non-exclusive mechanisms, including obstruction of
31520-544: The rules. After a stoppage, play recommences with a specified restart. At a professional level, most matches produce only a few goals. For example, the 2022–23 season of the English Premier League produced an average of 2.85 goals per match. The Laws of the Game do not specify any player positions other than goalkeeper, but a number of specialised roles have evolved. Broadly, these include three main categories: strikers , or forwards, whose main task
31717-427: The same time unlike many tournaments around the world for unknown reasons, although more recent tournaments have adopted this rule. The top two teams from each group advance to the knockout stage. Points are used to rank the teams within a group. Beginning in 1995 , three points have been awarded for a win , one for a draw and none for a loss (before, winners received two points). The ranking of each team in each group
31914-507: The sanitizing effect lasts for longer. In hospitals, quaternary ammonium compounds and bleach are used to sanitize rooms or equipment that have been occupied by people with influenza symptoms. At home, this can be done effectively with a diluted chlorine bleach. Since influenza viruses circulate in animals such as birds and pigs, prevention of transmission from these animals is important. Water treatment , indoor raising of animals, quarantining sick animals, vaccination, and biosecurity are
32111-404: The semis to reach the finals and overpower Paraguay 3–0, thus winning the trophy on Argentinean soil for the third time and second in a row. This, the 43rd edition, was the first time that neither Argentina nor Brazil reached the semifinals of a tournament they both had entered. The 2015 competition was hosted in Chile, who swapped hosting positions with Brazil in light of the latter's hosting of
32308-554: The sexes are so widely divided are all on the side of emancipation , and I look forward to the time when ladies may sit in Parliament and have a voice in the direction of affairs, especially those which concern them most." Honeyball and those like her paved the way for women's football. However, the women's game was frowned upon by the British football associations and continued without their support. It has been suggested that this
32505-458: The sick, there is mixed evidence on beneficial effects in the community. Smoking raises the risk of contracting influenza, as well as producing more severe disease symptoms. Since influenza spreads through both aerosols and contact with contaminated surfaces, surface sanitizing may help prevent some infections. Alcohol is an effective sanitizer against influenza viruses, while quaternary ammonium compounds can be used with alcohol so that
32702-492: The site of infection. Immune cells control viral infection by killing infected cells and phagocytizing viral particles and apoptotic cells. An exacerbated immune response can harm the host organism through a cytokine storm. To counter the immune response, influenza viruses encode various non-structural proteins, including NS1, NEP, PB1-F2, and PA-X, that are involved in curtailing the host immune response by suppressing interferon production and host gene expression. B cells ,
32899-428: The sole member of its own genus. The four influenza genera comprise four of the seven genera in the family Orthomyxoviridae . They are: Influenza A virus is responsible for most cases of severe illness as well as seasonal epidemics and occasional pandemics. It infects people of all ages but tends to disproportionately cause severe illness in the elderly, the very young, and those with chronic health issues. Birds are
33096-411: The sun, and crowding. Influenza viruses that infect the upper respiratory tract like H1N1 tend to be more mild but more transmissible, whereas those that infect the lower respiratory tract like H5N1 tend to cause more severe illness but are less contagious. In humans, influenza viruses first cause infection by infecting epithelial cells in the respiratory tract. Illness during infection is primarily
33293-475: The surface of the cell membrane. For N1 subtypes with the "G147R" mutation and N2 subtypes, the NA protein can initiate entry. Prior to binding, NA proteins promote access to target cells by degrading mucus, which helps to remove extracellular decoy receptors that would impede access to target cells. After binding, the virus is internalized into the cell by an endosome that contains the virion inside it. The endosome
33490-411: The ten members of the confederation. The format would remain constant with a first round of groups, but the final round stage ranged from being a new, final round-robin group or a single-elimination system to decide the winner. This renewal helped the tournament, which began to receive television coverage in Europe and North America. The 1987 Copa América was held in Argentina; this was the first time
33687-447: The time it was recovered, the clock had run out and the game was over, leaving Stoke unable to attempt the penalty. The same law also states that the duration of either half is extended until a penalty kick to be taken or retaken is completed; thus, no game can end with an uncompleted penalty. In league competitions, games may end in a draw. In knockout competitions where a winner is required, various methods may be employed to break such
33884-538: The time of the first recorded women's games in the late 19th century. The best-documented early European team was founded by activist Nettie Honeyball in England in 1894. It was named the British Ladies' Football Club . Honeyball is quoted as, "I founded the association late last year [1894], with the fixed resolve of proving to the world that women are not the 'ornamental and useless' creatures men have pictured. I must confess, my convictions on all matters where
34081-436: The tournament once again on Chilean soil. The event then entered a period of great disruption. The championship was not played on a regular basis and many editions would be deemed unofficial, only to be considered valid later on by CONMEBOL. For example, Argentina would be the first (and so far only) team to win three consecutive titles by winning the championships of 1945, 1946 and 1947 . After those three annual tournaments,
34278-422: The tournament or be the champion. Goals scored during extra time periods count towards the final score of the game, but kicks from the penalty mark are only used to decide the team that progresses to the next part of the tournament, with goals scored in a penalty shoot-out not making up part of the final score. In competitions using two-legged matches , each team competes at home once, with an aggregate score from
34475-511: The tournament. After a flu outbreak in Rio de Janeiro canceled the tournament in 1918, Brazil hosted the tournament in 1919 and was crowned champion for the first time after defeating the defending champions 1–0 in a playoff match to decide the title, while the Chilean city of Viña del Mar would host the 1920 event which was won by Uruguay. For the 1921 event, Paraguay participated for
34672-613: The transmission of cuju outside of China, especially the form of the game popular in the Tang dynasty , the period when the inflatable ball was invented and replaced the stuffed ball. Other East Asian games include kemari in Japan and chuk-guk in Korea, both influenced by cuju . Kemari originated after the year 600 during the Asuka period . It was a ceremonial rather than
34869-438: The transmission of influenza include good personal health and hygiene habits such as: not touching the eyes, nose or mouth; frequent hand washing (with soap and water, or with alcohol-based hand rubs); covering coughs and sneezes with a tissue or sleeve; avoiding close contact with sick people; and staying home when sick. Avoiding spitting is also recommended. Although face masks might help prevent transmission when caring for
35066-471: The trophy in perpetuity. Apart from the main trophy, the "Copa Bolivia" (a small trophy made in silver) has been awarded to the runner-up of the competition since the 1997 edition. The trophy is named after the country that hosted the 1997 Copa América, with a small Bolivian flag attached on one of its sides. There are currently five post-tournament awards Association football Association football , more commonly known as football or soccer ,
35263-439: The two matches deciding which team progresses. Where aggregates are equal, the away goals rule may be used to determine the winners, in which case the winner is the team that scored the most goals in the leg they played away from home. If the result is still equal, extra time and potentially a penalty shoot-out are required. Under the Laws, the two basic states of play during a game are ball in play and ball out of play . From
35460-400: The usual ten teams, CONMEBOL invited two countries from CONCACAF to participate, Mexico and the United States. Uruguay managed to win the competition in 1995 as host, ending a period of decline for Uruguayan football. With the implementation of rotating hosts, Colombia , Paraguay and Venezuela hosted the tournament for the first time. Brazil entered a series of victories, winning four of
35657-536: The viral surface, which helps prevent newly assembled viruses from aggregating near the cell surface and improving infectivity. Similar to other aspects of influenza replication, optimal NA activity is temperature- and pH-dependent. Ultimately, presence of large quantities of viral RNA in the cell triggers apoptosis (programmed cell death), which is initiated by cellular factors to restrict viral replication. Two key processes that influenza viruses evolve through are antigenic drift and antigenic shift . Antigenic drift
35854-477: The virus and last for about two to eight days. Diarrhea and vomiting can occur, particularly in children. Influenza may progress to pneumonia from the virus or a subsequent bacterial infection . Other complications include acute respiratory distress syndrome , meningitis , encephalitis , and worsening of pre-existing health problems such as asthma and cardiovascular disease . There are four types of influenza virus: types A, B, C, and D. Aquatic birds are
36051-461: The virus at greater quantities and for a longer duration than other children. People at risk of exposure to influenza include health care workers, social care workers, and those who live with or care for people vulnerable to influenza. In long-term care facilities, the flu can spread rapidly. A variety of factors likely encourage influenza transmission, including lower temperature, lower absolute and relative humidity , less ultraviolet radiation from
36248-613: The virus is disrupted by a detergent, and subunit, which only contains the viral antigens HA and NA. Most flu vaccines are inactivated and administered via intramuscular injection. LAIVs are sprayed into the nasal cavity. Vaccination recommendations vary by country. Some recommend vaccination for all people above a certain age, such as 6 months, whereas other countries limit recommendations to high-risk groups. Young infants cannot receive flu vaccines for safety reasons, but they can inherit passive immunity from their mother if vaccinated during pregnancy. Influenza vaccination helps to reduce
36445-481: The virus' antigenic properties, and to inform the development of vaccines. To unambiguously describe a specific isolate of virus, researchers use the internationally accepted influenza virus nomenclature, which describes, among other things, the species of animal from which the virus was isolated, and the place and year of collection. As an example – A/chicken/Nakorn-Patom/Thailand/CU-K2/04(H5N1) : The nomenclature for influenza B, C and D, which are less variable,
36642-560: The virus, and enzyme-linked immunoabsorbant assays. These methods tend to be relatively inexpensive and fast but are less reliable than nucleic-acid based tests. Direct fluorescent or immunofluorescent antibody (DFA/IFA) tests involve staining respiratory epithelial cells in samples with fluorescently-labeled influenza-specific antibodies, followed by examination under a fluorescent microscope. They can differentiate between influenza A virus and influenza B virus but can not subtype influenza A virus. Rapid influenza diagnostic tests (RIDTs) are
36839-405: The year in each country. Nine teams participated in the group stages with the defending champions receiving a bye into the semifinals. The tournament was contested every four years using this system until 1987. In 1986, CONMEBOL decided to return to having one country host the tournament and to contest it every other year. From 1987 until 2001 , the event was hosted every two years in rotation by
37036-516: Was Charterhouse . The Freemasons' Tavern was the setting for five more meetings of The FA between October and December 1863; the English FA eventually issued the first comprehensive set of rules named Laws of the Game , forming modern football. The laws included bans on running with the ball in hand and hacking (kicking an opponent in the shins), tripping and holding. Eleven clubs, under the charge of FA secretary Ebenezer Cobb Morley , ratified
37233-495: Was based on the original Copa América trophy's shape, added with the 2016 edition logo. The trophy was not to have a base. The CAC was 61 cm (24 in) tall with a weight of 7.1 kg (16 lb), covered by 24-carat gold. The emblems of CONMEBOL and CONCACAF were also engraved on its body. The commemorative Copa América Centenario trophy was designed by Epico Studios in the United States and manufactured by London Workshops of Thomas Lyte in England. The winning team will keep
37430-685: Was completed following the 2007 Copa América which took place in Venezuela. A second rotation commenced in 2011, with host countries rotating in alphabetical order, starting with Argentina. Chile, Mexico and the United States expressed interest in hosting the next tournament, but the CONMEBOL Executive Committee decided to continue the execution of the rotation, giving priority of the organization to each of its member associations; each association confirms whether they will host an edition or not, having no obligation to do so. Argentina confirmed on 24 November 2008, via representatives of
37627-533: Was first recorded as in exercise in the Zhan Guo Ce , a military history from the Han dynasty . Cuju players would pass the ball around, having to avoid it touching the ground at any point. It was then passed to a designated player, who attempted to kick it through the fengliu yan , a circular goal atop 10–11 meter poles. During the Han dynasty (206 BCE – 220 CE), cuju games were standardised and rules were established. The Silk Road facilitated
37824-419: Was first recorded in 1889 in the earlier form of socca . Kicking ball games arose independently multiple times across multiple cultures. The Chinese competitive game cuju ( 蹴鞠 , literally "kickball"; also known as tsu chu ) resembles modern association football as well as a mix of basketball, and volleyball. This is the earliest form of a kicking game for which there is historical evidence. The game
38021-544: Was growing in popularity, and the first international competition held among national teams of the continent occurred in 1910 when Argentina organized an event to commemorate the centenary of the May Revolution . Chile and Uruguay participated, but this event is not considered official by CONMEBOL . Similarly, for the centennial celebration of its independence, Argentina held a tournament between 2 and 17 July 1916 with Argentina, Chile, Uruguay and Brazil being
38218-420: Was held in the United States. The Copa América Centenario marked the first time the tournament was hosted by a non-CONMEBOL nation. Each Copa América since 2005 has had its own mascot . Gardelito , the mascot for the 1987 competition, was the first Copa América mascot . In early tournaments all teams competed in a round-robin stage, while later ones saw the teams were split into different groups followed by
38415-515: Was invited to the 2011 edition but declined to participate. The Copa América trophy, which is awarded to the winners of the tournament, was donated to the Association by the Ministry of Foreign Affairs of Argentina, Ernesto Bosch, in 1910 , when Argentina organized an event to commemorate the centenary of the May Revolution . That competition (also attended by Uruguay and Chile )
38612-504: Was motivated by a perceived threat to the "masculinity" of the game. Women's football became popular on a large scale at the time of the First World War , when female employment in heavy industry spurred the growth of the game, much as it had done for men 50 years earlier. The most successful team of the era was Dick, Kerr Ladies F.C. of Preston, England . The team played in one of the first women's international matches against
38809-474: Was named "Copa del Centenario" (Centennial Cup). The current Copa América trophy was purchased in 1916 from "Casa Escasany", a jewelry shop in Buenos Aires , at the cost of 3,000 Swiss francs . The Copa América trophy is a 9 kg (20 lb) weight and 77 cm (30 in) tall silver ornament, with a 3-level wooden base which contains several plaques. The plaques are engraved with every winner of
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