Radio is the technology of signalling or communicating using radio waves. Radio waves are electromagnetic waves of frequency between 300 gigahertz, they are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, received by a radio receiver connected to another antenna. Radio is widely used in modern technology, in radio communication, radio navigation, remote control, remote sensing and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking and satellite communication among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal in the transmitter. In radar, used to locate and track objects like aircraft, ships and missiles, a beam of radio waves emitted by a radar transmitter reflects off the target object, the reflected waves reveal the object's location. In radio navigation systems such as GPS and VOR, a mobile receiver receives radio signals from navigational radio beacons whose position is known, by measuring the arrival time of the radio waves the receiver can calculate its position on Earth.
In wireless remote control devices like drones, garage door openers, keyless entry systems, radio signals transmitted from a controller device control the actions of a remote device. Applications of radio waves which do not involve transmitting the waves significant distances, such as RF heating used in industrial processes and microwave ovens, medical uses such as diathermy and MRI machines, are not called radio; the noun radio is used to mean a broadcast radio receiver. Radio waves were first identified and studied by German physicist Heinrich Hertz in 1886; the first practical radio transmitters and receivers were developed around 1895-6 by Italian Guglielmo Marconi, radio began to be used commercially around 1900. To prevent interference between users, the emission of radio waves is regulated by law, coordinated by an international body called the International Telecommunications Union, which allocates frequency bands in the radio spectrum for different uses. Radio waves are radiated by electric charges undergoing acceleration.
They are generated artificially by time varying electric currents, consisting of electrons flowing back and forth in a metal conductor called an antenna. In transmission, a transmitter generates an alternating current of radio frequency, applied to an antenna; the antenna radiates the power in the current as radio waves. When the waves strike the antenna of a radio receiver, they push the electrons in the metal back and forth, inducing a tiny alternating current; the radio receiver connected to the receiving antenna detects this oscillating current and amplifies it. As they travel further from the transmitting antenna, radio waves spread out so their signal strength decreases, so radio transmissions can only be received within a limited range of the transmitter, the distance depending on the transmitter power, antenna radiation pattern, receiver sensitivity, noise level, presence of obstructions between transmitter and receiver. An omnidirectional antenna transmits or receives radio waves in all directions, while a directional antenna or high gain antenna transmits radio waves in a beam in a particular direction, or receives waves from only one direction.
Radio waves travel through a vacuum at the speed of light, in air at close to the speed of light, so the wavelength of a radio wave, the distance in meters between adjacent crests of the wave, is inversely proportional to its frequency. In radio communication systems, information is carried across space using radio waves. At the sending end, the information to be sent is converted by some type of transducer to a time-varying electrical signal called the modulation signal; the modulation signal may be an audio signal representing sound from a microphone, a video signal representing moving images from a video camera, or a digital signal consisting of a sequence of bits representing binary data from a computer. The modulation signal is applied to a radio transmitter. In the transmitter, an electronic oscillator generates an alternating current oscillating at a radio frequency, called the carrier wave because it serves to "carry" the information through the air; the information signal is used to modulate the carrier, varying some aspect of the carrier wave, impressing the information on the carrier.
Different radio systems use different modulation methods: AM - in an AM transmitter, the amplitude of the radio carrier wave is varied by the modulation signal. FM - in an FM transmitter, the frequency of the radio carrier wave is varied by the modulation signal. FSK - used in wireless digital devices to transmit digital signals, the frequency of the carrier wave is shifted periodically between two frequencies that represent the two binary digits, 0 and 1, to transmit a sequence of bits. OFDM - a family of complicated digital modulation methods widely used in high bandwidth systems such as WiFi networks, digital television broadcasting, digital audio broadcasting to transmit digital data using a minimum of radio spectrum bandwidth. OFDM has higher spectral efficiency and more resistance to fading than AM or FM. Multiple radio carrier waves spaced in frequency are transmitted within the radio channel, with each carrier modulated with bits from the incoming bitstream
Rio de Janeiro
Rio de Janeiro, or Rio, is anchor to the Rio de Janeiro metropolitan area and the second-most populous municipality in Brazil and the sixth-most populous in the Americas. Rio de Janeiro is the capital of the state of Brazil's third-most populous state. Part of the city has been designated as a World Heritage Site, named "Rio de Janeiro: Carioca Landscapes between the Mountain and the Sea", by UNESCO on 1 July 2012 as a Cultural Landscape. Founded in 1565 by the Portuguese, the city was the seat of the Captaincy of Rio de Janeiro, a domain of the Portuguese Empire. In 1763, it became the capital of the State of Brazil, a state of the Portuguese Empire. In 1808, when the Portuguese Royal Court transferred itself from Portugal to Brazil, Rio de Janeiro became the chosen seat of the court of Queen Maria I of Portugal, who subsequently, in 1815, under the leadership of her son, the Prince Regent, future King João VI of Portugal, raised Brazil to the dignity of a kingdom, within the United Kingdom of Portugal and Algarves.
Rio stayed the capital of the pluricontinental Lusitanian monarchy until 1822, when the War of Brazilian Independence began. This is one of the few instances in history that the capital of a colonising country shifted to a city in one of its colonies. Rio de Janeiro subsequently served as the capital of the independent monarchy, the Empire of Brazil, until 1889, the capital of a republican Brazil until 1960 when the capital was transferred to Brasília. Rio de Janeiro has the second largest municipal GDP in the country, 30th largest in the world in 2008, estimated at about R$343 billion, it is headquarters to Brazilian oil and telecommunications companies, including two of the country's major corporations – Petrobras and Vale – and Latin America's largest telemedia conglomerate, Grupo Globo. The home of many universities and institutes, it is the second-largest center of research and development in Brazil, accounting for 17% of national scientific output according to 2005 data. Despite the high perception of crime, the city has a lower incidence of crime than Northeast Brazil, but it is far more criminalized than the south region of Brazil, considered the safest in the country.
Rio de Janeiro is one of the most visited cities in the Southern Hemisphere and is known for its natural settings, samba, bossa nova, balneario beaches such as Barra da Tijuca, Copacabana and Leblon. In addition to the beaches, some of the most famous landmarks include the giant statue of Christ the Redeemer atop Corcovado mountain, named one of the New Seven Wonders of the World. Rio de Janeiro was the host of the 2016 Summer Olympics and the 2016 Summer Paralympics, making the city the first South American and Portuguese-speaking city to host the events, the third time the Olympics were held in a Southern Hemisphere city; the Maracanã Stadium held the finals of the 1950 and 2014 FIFA World Cups, the 2013 FIFA Confederations Cup, the XV Pan American Games. Europeans first encountered Guanabara Bay on 1 January 1502, by a Portuguese expedition under explorer Gaspar de Lemos, captain of a ship in Pedro Álvares Cabral's fleet, or under Gonçalo Coelho; the Florentine explorer Amerigo Vespucci participated as observer at the invitation of King Manuel I in the same expedition.
The region of Rio was inhabited by the Tupi, Puri and Maxakalí peoples. In 1555, one of the islands of Guanabara Bay, now called Villegagnon Island, was occupied by 500 French colonists under the French admiral Nicolas Durand de Villegaignon. Villegagnon built Fort Coligny on the island when attempting to establish the France Antarctique colony; the city of Rio de Janeiro proper was founded by the Portuguese on 1 March 1565 and was named São Sebastião do Rio de Janeiro, in honour of St. Sebastian, the saint, the namesake and patron of the Portuguese then-monarch Sebastião. Rio de Janeiro was the name of Guanabara Bay; until early in the 18th century, the city was threatened or invaded by several French pirates and buccaneers, such as Jean-François Duclerc and René Duguay-Trouin. In the late 17th century, still during the Sugar Era, the Bandeirantes discovered gold and diamonds in the neighbouring captaincy of Minas Gerais, thus Rio de Janeiro became a much more practical port for exporting wealth than Salvador, much farther northeast.
On 27 January 1763, the colonial administration in Portuguese America was moved from Salvador to Rio de Janeiro. The city remained a colonial capital until 1808, when the Portuguese royal family and most of the associated Lisbon nobles, fleeing from Napoleon's invasion of Portugal, moved to Rio de Janeiro; the kingdom's capital was transferred to the city, thus, became the only European capital outside of Europe. As there was no physical space or urban structure to accommodate hundreds of noblemen who arrived many inhabitants were evicted from their homes. In the first decades, several educational establishments were created, such as the Military Academy, the Royal School of Sciences and Crafts and the Imperial Academy of Fine Arts, as well as the National Library of Brazil – with the largest collection in Latin America – and The Botanical Garden; the first printed newspaper in Brazil, the Gazeta do Rio de Janeiro, came into circulation during this period. When Brazil was elevated to Kingdom in 1815, it
Venezuela the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and a large number of small islands and islets in the Caribbean Sea. The capital and largest urban agglomeration is the city of Caracas, it has a territorial extension of 916,445 km2. The continental territory is bordered on the north by the Caribbean Sea and the Atlantic Ocean, on the west by Colombia, Brazil on the south and Tobago to the north-east and on the east by Guyana. With this last country, the Venezuelan government maintains a claim for Guayana Esequiba over an area of 159,542 km2. For its maritime areas, it exercises sovereignty over 71,295 km2 of territorial waters, 22,224 km2 in its contiguous zone, 471,507 km2 of the Caribbean Sea and the Atlantic Ocean under the concept of exclusive economic zone, 99,889 km2 of continental shelf; this marine area borders those of 13 states. The country has high biodiversity and is ranked seventh in the world's list of nations with the most number of species.
There are habitats ranging from the Andes Mountains in the west to the Amazon basin rain-forest in the south via extensive llanos plains, the Caribbean coast and the Orinoco River Delta in the east. The territory now known as Venezuela was colonized by Spain in 1522 amid resistance from indigenous peoples. In 1811, it became one of the first Spanish-American territories to declare independence, not securely established until 1821, when Venezuela was a department of the federal republic of Gran Colombia, it gained full independence as a country in 1830. During the 19th century, Venezuela suffered political turmoil and autocracy, remaining dominated by regional caudillos until the mid-20th century. Since 1958, the country has had a series of democratic governments. Economic shocks in the 1980s and 1990s led to several political crises, including the deadly Caracazo riots of 1989, two attempted coups in 1992, the impeachment of President Carlos Andrés Pérez for embezzlement of public funds in 1993.
A collapse in confidence in the existing parties saw the 1998 election of former coup-involved career officer Hugo Chávez and the launch of the Bolivarian Revolution. The revolution began with a 1999 Constituent Assembly, where a new Constitution of Venezuela was written; this new constitution changed the name of the country to Bolivarian Republic of Venezuela. The sovereign state is a federal presidential republic consisting of 23 states, the Capital District, federal dependencies. Venezuela claims all Guyanese territory west of the Essequibo River, a 159,500-square-kilometre tract dubbed Guayana Esequiba or the Zona en Reclamación. Venezuela is among the most urbanized countries in Latin America. Oil was discovered in the early 20th century, today, Venezuela has the world's largest known oil reserves and has been one of the world's leading exporters of oil; the country was an underdeveloped exporter of agricultural commodities such as coffee and cocoa, but oil came to dominate exports and government revenues.
The 1980s oil glut led to a long-running economic crisis. Inflation peaked at 100% in 1996 and poverty rates rose to 66% in 1995 as per capita GDP fell to the same level as 1963, down a third from its 1978 peak; the recovery of oil prices in the early 2000s gave. The Venezuelan government under Hugo Chávez established populist social welfare policies that boosted the Venezuelan economy and increased social spending, temporarily reducing economic inequality and poverty in the early years of the regime. However, such populist policies became inadequate, causing the nation's collapse as their excesses—including a uniquely extreme fossil fuel subsidy—are blamed for destabilizing the nation's economy; the destabilized economy led to a crisis in Bolivarian Venezuela, resulting in hyperinflation, an economic depression, shortages of basic goods and drastic increases in unemployment, disease, child mortality and crime. These factors have precipitated the Venezuelan Migrant Crisis where more than three million people have fled the country.
By 2017, Venezuela was declared to be in default regarding debt payments by credit rating agencies. In 2018, the country's economic policies led to extreme hyperinflation, with estimates expecting an inflation rate of 1,370,000% by the end of the year. Venezuela is a charter member of the UN, OAS, UNASUR, ALBA, Mercosur, LAIA and OEI. According to the most popular and accepted version, in 1499, an expedition led by Alonso de Ojeda visited the Venezuelan coast; the stilt houses in the area of Lake Maracaibo reminded the Italian navigator, Amerigo Vespucci, of the city of Venice, Italy, so he named the region Veneziola, or "Little Venice". The Spanish version of Veneziola is Venezuela. Martín Fernández de Enciso, a member of the Vespucci and Ojeda crew, gave a different account. In his work Summa de geografía, he states that the crew found indigenous people who called themselves the Veneciuela. Thus, the name "Venezuela" may have evolved from the native word; the official name was Estado de Venezuela, República de Venezuela, Estados Unidos de Venezuela, a
Peru the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, in the west by the Pacific Ocean. Peru is a megadiverse country with habitats ranging from the arid plains of the Pacific coastal region in the west to the peaks of the Andes mountains vertically extending from the north to the southeast of the country to the tropical Amazon Basin rainforest in the east with the Amazon river. Peruvian territory was home to several ancient cultures. Ranging from the Norte Chico civilization in the 32nd century BC, the oldest civilization in the Americas and one of the five cradles of civilization, to the Inca Empire, the largest state in pre-Columbian America, the territory now including Peru has one of the longest histories of civilization of any country, tracing its heritage back to the 4th millennia BCE; the Spanish Empire conquered the region in the 16th century and established a viceroyalty that encompassed most of its South American colonies, with its capital in Lima.
Peru formally proclaimed independence in 1821, following the military campaigns of José de San Martín and Simón Bolívar, the decisive battle of Ayacucho, Peru secured independence in 1824. In the ensuing years, the country enjoyed relative economic and political stability, which ended shortly before the War of the Pacific with Chile. Throughout the 20th century, Peru endured armed territorial disputes, social unrest, internal conflicts, as well as periods of stability and economic upswing. Alberto Fujimori was elected to the presidency in 1990. Fujimori left the presidency in 2000 and was charged with human rights violations and imprisoned until his pardon by President Pedro Pablo Kuczynski in 2017. After the president's regime, Fujimori's followers, called Fujimoristas, have caused political turmoil for any opposing faction in power causing Pedro Pablo Kuczynski to resign in March 2018; the sovereign state of Peru is a representative democratic republic divided into 25 regions. It is classified as an emerging market with a high level of human development and an upper middle income level with a poverty rate around 19 percent.
It is one of the region's most prosperous economies with an average growth rate of 5.9% and it has one of the world's fastest industrial growth rates at an average of 9.6%. Its main economic activities include mining, manufacturing and fishing; the country forms part of The Pacific Pumas, a political and economic grouping of countries along Latin America's Pacific coast that share common trends of positive growth, stable macroeconomic foundations, improved governance and an openness to global integration. Peru ranks high in social freedom. Peru has a population of 32 million, which includes Amerindians, Europeans and Asians; the main spoken language is Spanish, although a significant number of Peruvians speak Quechua or other native languages. This mixture of cultural traditions has resulted in a wide diversity of expressions in fields such as art, cuisine and music; the name of the country may be derived from Birú, the name of a local ruler who lived near the Bay of San Miguel, Panama City, in the early 16th century.
When his possessions were visited by Spanish explorers in 1522, they were the southernmost part of the New World yet known to Europeans. Thus, when Francisco Pizarro explored the regions farther south, they came to be designated Birú or Perú. An alternative history is provided by the contemporary writer Inca Garcilaso de la Vega, son of an Inca princess and a conquistador, he said the name Birú was that of a common Indian happened upon by the crew of a ship on an exploratory mission for governor Pedro Arias de Ávila, went on to relate more instances of misunderstandings due to the lack of a common language. The Spanish Crown gave the name legal status with the 1529 Capitulación de Toledo, which designated the newly encountered Inca Empire as the province of Peru. Under Spanish rule, the country adopted the denomination Viceroyalty of Peru, which became Republic of Peru after independence; the earliest evidences of human presence in Peruvian territory have been dated to 9,000 BC. Andean societies were based on agriculture, terracing.
Organization relied on reciprocity and redistribution because these societies had no notion of market or money. The oldest known complex society in Peru, the Norte Chico civilization, flourished along the coast of the Pacific Ocean between 3,000 and 1,800 BC; these early developments were followed by archaeological cultures that developed around the coastal and Andean regions throughout Peru. The Cupisnique culture which flourished from around 1000 to 200 BC along what is now Peru's Pacific Coast was an example of early pre-Incan culture; the Chavín culture that developed from 1500 to 300 BC was more of a religious than a political phenomenon, with their religious centre in Chavín de Huantar. After the decline of the Chavin culture around the beginning of the 1st century AD, a series of localized and specialized cultures rose and fell
Barcelona is a city in Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second most populous municipality of Spain. With a population of 1.6 million within city limits, its urban area extends to numerous neighbouring municipalities within the Province of Barcelona and is home to around 4.8 million people, making it the sixth most populous urban area in the European Union after Paris, Madrid, the Ruhr area and Milan. It is one of the largest metropolises on the Mediterranean Sea, located on the coast between the mouths of the rivers Llobregat and Besòs, bounded to the west by the Serra de Collserola mountain range, the tallest peak of, 512 metres high. Founded as a Roman city, in the Middle Ages Barcelona became the capital of the County of Barcelona. After merging with the Kingdom of Aragon, Barcelona continued to be an important city in the Crown of Aragon as an economic and administrative centre of this Crown and the capital of the Principality of Catalonia.
Barcelona has a rich cultural heritage and is today an important cultural centre and a major tourist destination. Renowned are the architectural works of Antoni Gaudí and Lluís Domènech i Montaner, which have been designated UNESCO World Heritage Sites; the headquarters of the Union for the Mediterranean are located in Barcelona. The city is known for hosting the 1992 Summer Olympics as well as world-class conferences and expositions and many international sport tournaments. Barcelona is one of the world's leading tourist, trade fair and cultural centres, its influence in commerce, entertainment, fashion and the arts all contribute to its status as one of the world's major global cities, it is a major cultural and economic centre in southwestern Europe, 24th in the world and a financial centre. In 2008 it was the fourth most economically powerful city by GDP in the European Union and 35th in the world with GDP amounting to €177 billion. In 2012 Barcelona had a GDP of $170 billion. In 2009 the city was ranked one of the world's most successful as a city brand.
In the same year the city was ranked Europe's fourth best city for business and fastest improving European city, with growth improved by 17% per year, the city has been experiencing strong and renewed growth for the past three years. Since 2011 Barcelona has been a leading smart city in Europe. Barcelona is a transport hub, with the Port of Barcelona being one of Europe's principal seaports and busiest European passenger port, an international airport, Barcelona–El Prat Airport, which handles over 50 million passengers per year, an extensive motorway network, a high-speed rail line with a link to France and the rest of Europe; the name Barcelona comes from the ancient Iberian Barkeno, attested in an ancient coin inscription found on the right side of the coin in Iberian script as, in ancient Greek sources as Βαρκινών, Barkinṓn. Some older sources suggest that the city may have been named after the Carthaginian general Hamilcar Barca, supposed to have founded the city in the 3rd century BC, but there is no evidence that Barcelona was a Carthaginian settlement, or that its name in antiquity, had any connection with the Barcid family of Hamilcar.
During the Middle Ages, the city was variously known as Barchinona, Barçalona and Barchenona. Internationally, Barcelona's name is wrongly abbreviated to'Barça'. However, this name refers only to the football club; the common abbreviated form used by locals is Barna. Another common abbreviation is'BCN', the IATA airport code of the Barcelona-El Prat Airport; the city is referred to as the Ciutat Comtal in Catalan, Ciudad Condal in Spanish, owing to its past as the seat of the Count of Barcelona. The origin of the earliest settlement at the site of present-day Barcelona is unclear; the ruins of an early settlement have been found, including different tombs and dwellings dating to earlier than 5000 BC. The founding of Barcelona is the subject of two different legends; the first attributes the founding of the city to the mythological Hercules. The second legend attributes the foundation of the city directly to the historical Carthaginian general, Hamilcar Barca, father of Hannibal, who named the city Barcino after his family in the 3rd century BC, but there is no historical or linguistic evidence that this is true.
In about 15 BC, the Romans redrew the town as a castrum centred on the "Mons Taber", a little hill near the contemporary city hall. Under the Romans, it was a colony with the surname of Faventia, or, in full, Colonia Faventia Julia Augusta Pia Barcino or Colonia Julia Augusta Faventia Paterna Barcino. Pomponius Mela mentions it among the small towns of the district as it was eclipsed by its neighbour Tarraco, but it may be gathered from writers that it grew in wealth and consequence, favoured as it was with a beautiful situation and an excellent harbour, it enjoyed immunity from imperial burdens. The city minted its own coins. Important Roman vestiges are displayed in Plaça del Rei underground, as a part of the Barcelona City History Museum; some remaining fragments of the Roman walls have been incorporated into the cathedral. The cathedral known as the Basilica La Seu, is said to have been founded in 343; the city
Argentina the Argentine Republic, is a country located in the southern half of South America. Sharing the bulk of the Southern Cone with Chile to the west, the country is bordered by Bolivia and Paraguay to the north, Brazil to the northeast and the South Atlantic Ocean to the east, the Drake Passage to the south. With a mainland area of 2,780,400 km2, Argentina is the eighth-largest country in the world, the fourth largest in the Americas, the largest Spanish-speaking nation; the sovereign state is subdivided into twenty-three provinces and one autonomous city, Buenos Aires, the federal capital of the nation as decided by Congress. The provinces and the capital exist under a federal system. Argentina claims sovereignty over part of Antarctica, the Falkland Islands, South Georgia and the South Sandwich Islands; the earliest recorded human presence in modern-day Argentina dates back to the Paleolithic period. The Inca Empire expanded to the northwest of the country in Pre-Columbian times; the country has its roots in Spanish colonization of the region during the 16th century.
Argentina rose as the successor state of the Viceroyalty of the Río de la Plata, a Spanish overseas viceroyalty founded in 1776. The declaration and fight for independence was followed by an extended civil war that lasted until 1861, culminating in the country's reorganization as a federation of provinces with Buenos Aires as its capital city; the country thereafter enjoyed relative peace and stability, with several waves of European immigration radically reshaping its cultural and demographic outlook. The almost-unparalleled increase in prosperity led to Argentina becoming the seventh wealthiest nation in the world by the early 20th century. Following the Great Depression in the 1930s, Argentina descended into political instability and economic decline that pushed it back into underdevelopment, though it remained among the fifteen richest countries for several decades. Following the death of President Juan Perón in 1974, his widow, Isabel Martínez de Perón, ascended to the presidency, she was overthrown in 1976 by a U.
S.-backed coup which installed a right-wing military dictatorship. The military government persecuted and murdered numerous political critics and leftists in the Dirty War, a period of state terrorism that lasted until the election of Raúl Alfonsín as President in 1983. Several of the junta's leaders were convicted of their crimes and sentenced to imprisonment. Argentina is a prominent regional power in the Southern Cone and Latin America, retains its historic status as a middle power in international affairs. Argentina has the second largest economy in South America, the third-largest in Latin America, membership in the G-15 and G-20 major economies, it is a founding member of the United Nations, World Bank, World Trade Organization, Union of South American Nations, Community of Latin American and Caribbean States and the Organization of Ibero-American States. Despite its history of economic instability, it ranks second highest in the Human Development Index in Latin America; the description of the country by the word Argentina has been found on a Venetian map in 1536.
In English the name "Argentina" comes from the Spanish language, however the naming itself is not Spanish, but Italian. Argentina means in Italian " of silver, silver coloured" borrowed from the Old French adjective argentine " of silver" > "silver coloured" mentioned in the 12th century. The French word argentine is the feminine form of argentin and derives from argent "silver" with the suffix -in; the Italian naming "Argentina" for the country implies Terra Argentina "land of silver" or Costa Argentina "coast of silver". In Italian, the adjective or the proper noun is used in an autonomous way as a substantive and replaces it and it is said l'Argentina; the name Argentina was first given by the Venetian and Genoese navigators, such as Giovanni Caboto. In Spanish and Portuguese, the words for "silver" are plata and prata and " of silver" is said plateado and prateado. Argentina was first associated with the silver mountains legend, widespread among the first European explorers of the La Plata Basin.
The first written use of the name in Spanish can be traced to La Argentina, a 1602 poem by Martín del Barco Centenera describing the region. Although "Argentina" was in common usage by the 18th century, the country was formally named "Viceroyalty of the Río de la Plata" by the Spanish Empire, "United Provinces of the Río de la Plata" after independence; the 1826 constitution included the first use of the name "Argentine Republic" in legal documents. The name "Argentine Confederation" was commonly used and was formalized in the Argentine Constitution of 1853. In 1860 a presidential decree settled the country's name as "Argentine Republic", that year's constitutional amendment ruled all the names since 1810 as valid. In the English language the country was traditionally called "the Argentine", mimicking the typical Spanish usage la Argentina and resulting from a mistaken shortening of the fuller name'Argentine Republic'.'The Argentine' fell out of fashion during the mid-to-late 20th century, now the country is referred to as "Argentina".
In the Spanish language "Argentina" is feminine, taking the feminine article "La" as the i
Fidel Alejandro Castro Ruz was a Cuban communist revolutionary and politician who governed the Republic of Cuba as Prime Minister from 1959 to 1976 and as President from 1976 to 2008. A Marxist–Leninist and Cuban nationalist, Castro served as the First Secretary of the Communist Party of Cuba from 1961 until 2011. Under his administration, Cuba became a one-party communist state, while industry and business were nationalized and state socialist reforms were implemented throughout society. Born in Birán, Oriente as the son of a wealthy Spanish farmer, Castro adopted leftist anti-imperialist politics while studying law at the University of Havana. After participating in rebellions against right-wing governments in the Dominican Republic and Colombia, he planned the overthrow of Cuban President Fulgencio Batista, launching a failed attack on the Moncada Barracks in 1953. After a year's imprisonment, Castro traveled to Mexico where he formed a revolutionary group, the 26th of July Movement, with his brother Raúl Castro and Che Guevara.
Returning to Cuba, Castro took a key role in the Cuban Revolution by leading the Movement in a guerrilla war against Batista's forces from the Sierra Maestra. After Batista's overthrow in 1959, Castro assumed military and political power as Cuba's Prime Minister; the United States came to oppose Castro's government and unsuccessfully attempted to remove him by assassination, economic blockade and counter-revolution, including the Bay of Pigs Invasion of 1961. Countering these threats, Castro aligned with the Soviet Union and allowed the Soviets to place nuclear weapons in Cuba, sparking the Cuban Missile Crisis – a defining incident of the Cold War – in 1962. Adopting a Marxist–Leninist model of development, Castro converted Cuba into a one-party, socialist state under Communist Party rule, the first in the Western Hemisphere. Policies introducing central economic planning and expanding healthcare and education were accompanied by state control of the press and the suppression of internal dissent.
Abroad, Castro supported anti-imperialist revolutionary groups, backing the establishment of Marxist governments in Chile and Grenada, as well as sending troops to aid allies in the Yom Kippur and Angolan Civil War. These actions, coupled with Castro's leadership of the Non-Aligned Movement from 1979 to 1983 and Cuba's medical internationalism, increased Cuba's profile on the world stage. Following the Soviet Union's dissolution in 1991, Castro led Cuba through the economic downturn of the "Special Period", embracing environmentalist and anti-globalization ideas. In the 2000s, Castro forged alliances in the Latin American "pink tide" – namely with Hugo Chávez's Venezuela – and signed Cuba up to the Bolivarian Alliance for the Americas. In 2006, Castro transferred his responsibilities to Vice President Raúl Castro, elected to the presidency by the National Assembly in 2008; the longest-serving non-royal head of state in the 20th and 21st centuries, Castro polarized world opinion. His supporters view him as a champion of socialism and anti-imperialism whose revolutionary regime advanced economic and social justice while securing Cuba's independence from American imperialism.
Critics view him as a dictator whose administration oversaw human-rights abuses, the exodus of a large number of Cubans and the impoverishment of the country's economy. Castro was decorated with various international awards and influenced different individuals and groups across the world. Castro was born out of wedlock at his father's farm on 13 August 1926, his father, Ángel Castro y Argiz, a veteran of the Spanish–American War, was a migrant to Cuba from Galicia, Northwest Spain. He had become financially successful by growing sugar cane at Las Manacas farm in Birán, Oriente Province. After the collapse of his first marriage he took his household servant, Lina Ruz González – of Canarian origin – as his mistress and second wife. At age six, Castro was sent to live with his teacher in Santiago de Cuba, before being baptized into the Roman Catholic Church at the age of eight. Being baptized enabled Castro to attend the La Salle boarding school in Santiago, where he misbehaved. In 1945, Castro transferred to the more prestigious Jesuit-run El Colegio de Belén in Havana.
Although Castro took an interest in history and debating at Belén, he did not excel academically, instead devoting much of his time to playing sports. In 1945, Castro began studying law at the University of Havana. Admitting he was "politically illiterate", Castro became embroiled in student activism and the violent gangsterismo culture within the university. Passionate about anti-imperialism and opposing U. S. intervention in the Caribbean, he unsuccessfully campaigned for the presidency of the Federation of University Students on a platform of "honesty and justice". Castro became critical of the corruption and violence of President Ramón Grau's government, delivering a public speech on the subject in November 1946 that received coverage on the front page of several newspapers. In 1947, Castro joined the Party of the Cuban People, founded by veteran politician Eduardo Chibás. A charismatic figure, Chibás advocated social justice, honest government and political freedom, while his party exposed corruption and demanded reform.
Though Chibás came third in the 1948 general election, Castro remained committed to working on his behalf. Student violence escalated after Grau employed gang leaders as police officers, Castro soon received a death threat urging him to leave the university. However, he refused to do so an