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2020–2021 Taal Volcano Eruptions
Taal Volcano in Batangas, Philippines began to erupt on January 12, 2020, when a phreatomagmatic eruption from its main crater spewed ashes over Calabarzon, Metro Manila, and some parts of Central Luzon and Ilocos Region, resulting in the suspension of school classes, work schedules, and flights in the area. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) subsequently issued an Alert Level 4, indicating "that a hazardous explosive eruption is possible within hours to days." Volcanic activity continued into 2021, when smaller eruptions occurred in July 2021.
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Biography
Janet Pierrehumbert
Janet Pierrehumbert /pɪərˈhʌmbərt/ is Professor of Language Modeling in the Oxford e-Research Centre at the University of Oxford and a senior research fellow of Trinity College, Oxford.[1] She developed an intonational model which includes a grammar of intonation patterns and an explicit algorithm for calculating pitch contours in speech, as well as an account of intonational meaning.[2][3]
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Topic Review
Transit of Venus, 2012
The 2012 transit of Venus, when the planet Venus appeared as a small, dark spot passing across the face of the Sun, began at 22:09 UTC on 5 June 2012, and finished at 04:49 UTC on 6 June. Depending on the position of the observer, the exact times varied by up to ±7 minutes. Transits of Venus are among the rarest of predictable celestial phenomena and occur in pairs. Consecutive transits per pair are spaced 8 years apart, and consecutive pairs occur more than a century apart: The previous transit of Venus took place on 8 June 2004 (preceded by transits on 9 December 1874 and 6 December 1882); the next pair of transits will occur on 10–11 December 2117 and in December 2125.
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Topic Review
Eurypterida
Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic chelicerate order. Following their appearance during the Ordovician, eurypterids became major components of marine faunas during the Silurian, from which the majority of eurypterid species have been described. The Silurian genus Eurypterus accounts for more than 90% of all known eurypterid specimens. Though the group continued to diversify during the subsequent Devonian period, the eurypterids were heavily affected by the Late Devonian extinction event. They declined in numbers and diversity until becoming extinct during the Permian–Triassic extinction event (or sometime shortly before) 251.9 million years ago. Although popularly called "sea scorpions", only the earliest eurypterids were marine; many later forms lived in brackish or fresh water, and they were not true scorpions. Some studies suggest that a dual respiratory system was present, which would have allowed for short periods of time in terrestrial environments. The name Eurypterida comes from the Ancient Greek words εὐρύς (eurús), meaning 'broad' or 'wide', and πτερόν (pterón), meaning 'wing', referring to the pair of wide swimming appendages present in many members of the group. The eurypterids include the largest known arthropods ever to have lived. The largest, Jaekelopterus, reached 2.5 meters (8.2 ft) in length. Eurypterids were not uniformly large and most species were less than 20 centimeters (8 in) long; the smallest eurypterid, Alkenopterus, was only 2.03 centimeters (0.80 in) long. Eurypterid fossils have been recovered from every continent. A majority of fossils are from fossil sites in North America and Europe because the group lived primarily in the waters around and within the ancient supercontinent of Euramerica. Only a handful of eurypterid groups spread beyond the confines of Euramerica and a few genera, such as Adelophthalmus and Pterygotus, achieved a cosmopolitan distribution with fossils being found worldwide.
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Topic Review
List of Jupiter Trojans (Trojan Camp) (300001–400000)
This is a partial list of Jupiter's L5 trojans (60° behind Jupiter) with numbers 300001–400000 (also see main page).
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Topic Review
Economic Policy of the Indira Gandhi Premiership
The economic policy of the Indira Gandhi premiership was characterized by moderate tax increases on higher income Indians, bank nationalisation, green revolution. Gandhi presided over three Five-Year Plans as Prime Minister, two of which succeeded in meeting the targeted growth. There is considerable debate regarding whether Gandhi was a socialist on principle or out of political expediency. Sunanda K. Datta-Ray described her as "a master of rhetoric...often more posture than policy", while The Times journalist, Peter Hazelhurst, famously quipped that Gandhi's socialism was "slightly left of self-interest." Critics have focused on the contradictions in the evolution of her stance towards communism; Gandhi being known for her anti-communist stance in the 1950s with Meghnad Desai even describing her as "the scourge of [India's] Communist Party." Yet, she later forged close relations with Indian communists even while using the army to break the Naxalites. In this context, Gandhi was accused of formulating populist policies to suit her political needs; being seemingly against the rich and big business while preserving the status quo in order to manipulate the support of the left at times of political insecurity, such as the late 1960s. Although Gandhi came to be viewed in time as the scourge of the right-wing and reactionary political elements of India, leftist opposition to her policies emerged. As early as 1969, critics had begun accusing her of insincerity and machiavellianism. The Indian Libertarian wrote that: "it would be difficult to find a more machiavellian leftist than Mrs Indira Gandhi...for here is Machiavelli at its best in the person of a suave, charming and astute politician." Rosser wrote that "some have even seen the declaration of emergency rule in 1975 as a move to suppress [leftist] dissent against Gandhi's policy shift to the right." In the 1980s, Gandhi was accused of "betraying socialism" after the beginning of Operation Forward, an attempt at economic reform. Nevertheless, others were more convinced of Gandhi's sincerity and devotion to socialism. Pankaj Vohra noted that "even the late prime minister's critics would concede that the maximum number of legislations of social significance was brought about during her tenure...[and that] she lives in the hearts of millions of Indians who shared her concern for the poor and weaker sections and who supported her politics." In summarizing the biographical works on Gandhi, Blema S. Steinberg concluded she was decidedly non-ideological. Only 7.4% (24) of the total 330 biographical extractions posit ideology as a reason for her policy choices. Steinberg noted Gandhi's association with socialism was superficial; only having a general and traditional commitment to the ideology, by way of her political and family ties. Gandhi personally had a fuzzy concept of socialism. In one of the early interviews she had given as Prime Minister, Gandhi had ruminated: "I suppose you could call me a socialist, but you have understand what we mean by that term...we used the word [socialism] because it came closest to what we wanted to do here – which is to eradicate poverty. You can call it socialism; but if by using that word we arouse controversy, I don't see why we should use it. I don't believe in words at all." Regardless of the debate over her ideology or lack of thereof, Gandhi remains a left-wing icon. She has been described by Hindustan Times columnist, Pankaj Vohra as "arguably the greatest mass leader of the last century." Her campaign slogan, Garibi Hatao ('Remove Poverty'), has become the iconic motto of the Indian National Congress. To the rural and urban poor, untouchables, minorities and women in India, Gandhi was "Indira Amma or Mother Indira."
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Topic Review
Independent Labour Party
The Independent Labour Party (ILP) was a British political party of the left, established in 1893, when the Liberals appeared reluctant to endorse working-class candidates, representing the interests of the majority. A sitting independent MP and prominent union organiser, Keir Hardie, became its first chairman. The party was positioned to the left of Ramsay MacDonald’s Labour Representation Committee, which was founded in 1900 and soon renamed the Labour Party, and to which the ILP was affiliated from 1906 to 1932. In 1947, the organisation's three parliamentary representatives defected to the Labour Party, and the organisation rejoined Labour as Independent Labour Publications in 1975.
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Topic Review
Doubling Time
The doubling time is time it takes for a population to double in size/value. It is applied to population growth, inflation, resource extraction, consumption of goods, compound interest, the volume of malignant tumours, and many other things that tend to grow over time. When the relative growth rate (not the absolute growth rate) is constant, the quantity undergoes exponential growth and has a constant doubling time or period, which can be calculated directly from the growth rate. This time can be calculated by dividing the natural logarithm of 2 by the exponent of growth, or approximated by dividing 70 by the percentage growth rate (more roughly but roundly, dividing 72; see the rule of 72 for details and derivatiatives of this formula). The doubling time is a characteristic unit (a natural unit of scale) for the exponential growth equation, and its converse for exponential decay is the half-life. For example, given Canada's net population growth of 0.9% in the year 2006, dividing 70 by 0.9 gives an approximate doubling time of 78 years. Thus if the growth rate remains constant, Canada's population would double from its 2006 figure of 33 million to 66 million by 2084.
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Topic Review
Tropical Savanna Climate
Tropical savanna climate or tropical wet and dry climate is a type of climate that corresponds to the Köppen climate classification categories Aw (for a dry winter) and As (for a dry summer). Tropical savanna climates have monthly mean temperatures above 18 °C (64 °F) in every month of the year and typically a pronounced dry season, with the driest month having less than 60 mm (2.36 inches) of precipitation and also less than [math]\displaystyle{ 100-\left (\frac{Total\ Annual\ Precipitation\ (mm)}{25} \right) }[/math] of precipitation :200–1 This latter fact is in direct contrast to a tropical monsoon climate, whose driest month sees less than 60 mm of precipitation but has more than [math]\displaystyle{ 100-\left (\frac{Total\ Annual\ Precipitation\ (mm)}{25} \right) }[/math] of precipitation. In essence, a tropical savanna climate tends to either see less rainfall than a tropical monsoon climate or have more pronounced dry season(s). In tropical savanna climates, the dry season can become severe, and often drought conditions prevail during the course of the year. Tropical savanna climates often feature tree-studded grasslands, rather than thick jungle. It is this widespread occurrence of tall, coarse grass (called savanna) which has led to Aw and As climates often being referred to as tropical savanna. However, there is some doubt whether tropical grasslands are climatically induced. Additionally, pure savannas, without trees, are the exception rather than the rule.
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Topic Review
Semaphore Telegraph
A semaphore telegraph is an early system of conveying information by means of visual signals, using towers with pivoting shutters, also known as blades or paddles. Information is encoded by the position of the mechanical elements; it is read when the shutter is in a fixed position. The most widely used system was invented in 1792 in France by Claude Chappe, and was popular in the late eighteenth to early nineteenth centuries. Lines of relay towers with a semaphore rig at the top were built within line-of-sight of each other, at separations of 5–20 miles (8.0–32.2 km). Operators at each tower would watch the neighboring tower through a spyglass, and when the semaphore arms began to move spelling out a message, they would pass the message on to the next tower. This system was much faster than post riders for conveying a message over long distances, and also had cheaper long-term operating costs, once constructed. Semaphore lines were a precursor of the electrical telegraph, which would replace them half a century later, and would also be cheaper, faster, and more private. The line-of-sight distance between relay stations was limited by geography and weather, and prevented the optical telegraph from crossing wide expanses of water, unless a convenient island could be used for a relay station. Modern derivatives of the semaphore system include flag semaphore (a flag relay system) and the heliograph (optical telegraphy using mirror-directed sunlight reflections).
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