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Topic Review
2010 Flash Crash
The May 6, 2010, Flash Crash, also known as the Crash of 2:45, the 2010 Flash Crash or simply the Flash Crash, was a United States trillion-dollar stock market crash, which started at 2:32 p.m. EDT and lasted for approximately 36 minutes.:1 Stock indexes, such as the S&P 500, Dow Jones Industrial Average and Nasdaq Composite, collapsed and rebounded very rapidly. The Dow Jones Industrial Average had its second biggest intraday point drop (from the opening) up to that point, plunging 998.5 points (about 9%), most within minutes, only to recover a large part of the loss. It was also the second-largest intraday point swing (difference between intraday high and intraday low) up to that point, at 1,010.14 points. The prices of stocks, stock index futures, options and exchange-traded funds (ETFs) were volatile, thus trading volume spiked.:3 A CFTC 2014 report described it as one of the most turbulent periods in the history of financial markets.:1 When new regulations put in place following the 2010 Flash Crash proved to be inadequate to protect investors in the August 24, 2015 flash crash—"when the price of many ETFs appeared to come unhinged from their underlying value"—ETFs were put under greater scrutiny by regulators and investors. On April 21, 2015, nearly five years after the incident, the U.S. Department of Justice laid "22 criminal counts, including fraud and market manipulation" against Navinder Singh Sarao, a trader. Among the charges included was the use of spoofing algorithms; just prior to the Flash Crash, he placed thousands of E-mini S&P 500 stock index futures contracts which he planned on canceling later. These orders amounting to about "$200 million worth of bets that the market would fall" were "replaced or modified 19,000 times" before they were canceled. Spoofing, layering, and front running are now banned. The Commodity Futures Trading Commission (CFTC) investigation concluded that Sarao "was at least significantly responsible for the order imbalances" in the derivatives market which affected stock markets and exacerbated the flash crash. Sarao began his alleged market manipulation in 2009 with commercially available trading software whose code he modified "so he could rapidly place and cancel orders automatically." Traders Magazine journalist, John Bates, argued that blaming a 36-year-old small-time trader who worked from his parents' modest stucco house in suburban west London for sparking a trillion-dollar stock market crash is a little bit like blaming lightning for starting a fire" and that the investigation was lengthened because regulators used "bicycles to try and catch Ferraris." Furthermore, he concluded that by April 2015, traders can still manipulate and impact markets in spite of regulators and banks' new, improved monitoring of automated trade systems. As recently as May 2014, a CFTC report concluded that high-frequency traders "did not cause the Flash Crash, but contributed to it by demanding immediacy ahead of other market participants.":1 Some recent peer-reviewed research shows that flash crashes are not isolated occurrences, but have occurred quite often. Gao and Mizrach studied US equities over the period of 1993–2011. They show that breakdowns in market quality (such as flash crashes) have occurred in every year they examined and that, apart from the financial crisis, such problems have declined since the introduction of Reg NMS. They also show that 2010, while infamous for the Flash Crash, was not a year with an inordinate number of breakdowns in market quality.
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  • 30 Nov 2022
Topic Review
Nose Ring (Animal)
A nose ring is inserted into the nose of an animal. Nose rings are used to control bulls and occasionally cows, and to help wean young cattle by preventing suckling. Nose rings are used on pigs to discourage rooting. Some nose rings are installed through a pierced hole in the nasal septum or rim of the nose and remain there, while others are temporary tools.
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  • 03 Nov 2022
Topic Review
Parallel Processing (Psychology)
In psychology, parallel processing is the ability of the brain to simultaneously process incoming stimuli of differing quality. Parallel processing is associated with the visual system in that the brain divides what it sees into four components: color, motion, shape, and depth. These are individually analyzed and then compared to stored memories, which helps the brain identify what you are viewing. The brain then combines all of these into the field of view that then seen and comprehended. Parallel processing has been linked, by some experimental psychologists, to the stroop effect. This is a continual and seamless operation. For example, if one is standing between two different groups of people who are simultaneously carrying on two different conversations, one may be able to pick up only some information of both conversation at the same time.
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  • 02 Dec 2022
Topic Review
Support Vector Machine
In machine learning, support-vector machines (SVMs, also support-vector networks) are supervised learning models with associated learning algorithms that analyze data used for classification and regression analysis. The Support Vector Machine (SVM) algorithm is a popular machine learning tool that offers solutions for both classification and regression problems. Developed at AT&T Bell Laboratories by Vapnik with colleagues (Boser et al., 1992, Guyon et al., 1993, Vapnik et al., 1997), it presents one of the most robust prediction methods, based on the statistical learning framework or VC theory proposed by Vapnik and Chervonekis (1974) and Vapnik (1982, 1995). Given a set of training examples, each marked as belonging to one or the other of two categories, an SVM training algorithm builds a model that assigns new examples to one category or the other, making it a non-probabilistic binary linear classifier (although methods such as Platt scaling exist to use SVM in a probabilistic classification setting). An SVM model is a representation of the examples as points in space, mapped so that the examples of the separate categories are divided by a clear gap that is as wide as possible. New examples are then mapped into that same space and predicted to belong to a category based on the side of the gap on which they fall. In addition to performing linear classification, SVMs can efficiently perform a non-linear classification using what is called the kernel trick, implicitly mapping their inputs into high-dimensional feature spaces. When data are unlabelled, supervised learning is not possible, and an unsupervised learning approach is required, which attempts to find natural clustering of the data to groups, and then map new data to these formed groups. The support-vector clustering algorithm, created by Hava Siegelmann and Vladimir Vapnik, applies the statistics of support vectors, developed in the support vector machines algorithm, to categorize unlabeled data, and is one of the most widely used clustering algorithms in industrial applications.
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  • 14 Oct 2022
Topic Review
Solid Waste Management in Middle East Arab Countries
Solid waste production, specifically construction waste, in Middle Eastern Arab countries has dramatically increased. This is characterized by several factors, including rapid urbanization, common food wasting habits, diverse culture, lack of proper planning of solid waste processes, insufficient equipment, as well as lack of proper funding. The exponential growth in solid waste generation rates has led to hazards to health and the environment, causing issues related to air and water pollution under the already increasing pressure of climate change.
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  • 17 Nov 2022
Topic Review
Younger Dryas
The Younger Dryas (around 12,900 to 11,700 years BP) was a return to glacial conditions after the Late Glacial Interstadial, which temporarily reversed the gradual climatic warming after the Last Glacial Maximum (LGM) started receding around 20,000 BP. It is named after an indicator genus, the alpine-tundra wildflower Dryas octopetala, as its leaves are occasionally abundant in late glacial, often minerogenic-rich sediments, such as the lake sediments of Scandinavia. Physical evidence of a sharp decline in temperature over most of the Northern Hemisphere has been discovered by geological research. This temperature change occurred at the end of what the earth sciences refer to as the Pleistocene epoch and immediately before the current, warmer Holocene epoch. In archaeology, this time frame coincides with the final stages of the Upper Paleolithic in many areas. The Younger Dryas was the most recent and longest of several interruptions to the gradual warming of the Earth's climate since the severe LGM, about 27,000 to 24,000 years BP. The change was relatively sudden, taking place in decades, and it resulted in a decline of temperatures in Greenland by 4 to 10°C (7.2 to 18°F) and advances of glaciers and drier conditions, over much of the temperate Northern Hemisphere. It is thought to have been caused by a decline in the strength of the Atlantic meridional overturning circulation, which transports warm water from the Equator towards the North Pole, in turn thought to have been caused by an influx of fresh, cold water from North America to the Atlantic. The Younger Dryas was a period of climatic change, but the effects were complex and variable. In the Southern Hemisphere and some areas of the Northern Hemisphere, such as southeastern North America, a slight warming occurred.
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  • 14 Oct 2022
Topic Review
Tropylium Ion
The tropylium ion is a non-benzenoid aromatic species that works as a catalyst. This chemical entity brings about a large number of organic transformations, such as hydroboration reactions, ring contraction, the trapping of enolates, oxidative functionalization, metathesis, insertion, acetalization, and trans-acetalization reactions. The tropylium ion also functions as a coupling reagent in synthetic reactions. This cation’s versatility can be seen in its role in the synthesis of macrocyclic compounds and cage structures.
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  • 01 Jun 2023
Topic Review
Vegetable Oils as Lubricants
Vegetable oils have been used as metalworking fluids (MWFs) for many years, particularly in small-scale metalworking operations and in industries where environmental regulations are strict. Before the development of modern MWFs, vegetable oils were one of the most common lubricants used for metalworking tools. The use of vegetable oils can be traced back to ancient civilizations such as Egypt, Greece, and Rome, where olive oil was commonly used to lubricate metal tools and weapons. 
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  • 19 Apr 2023
Topic Review
Hoveyda–Grubbs Catalyst
Hoveyda–Grubbs-type complexes, ruthenium catalysts for olefin metathesis, have gained increased interest as a research target in the interdisciplinary research fields of chemistry and biology because of their high functional group selectivity in olefin metathesis reactions and stabilities in aqueous media.
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  • 26 Mar 2021
Topic Review
Snake Dry Bites
Snake ‘dry bites’ are characterized by the absence of venom being injected into the victim during a snakebite incident. The dry bite mechanism and diagnosis are quite complex, and the lack of envenoming symptoms in these cases may be misinterpreted as a miraculous treatment or as proof that the bite from the perpetrating snake species is rather harmless.
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  • 01 Dec 2020
Topic Review Video
Risk Management in Information Systems
Businesses are bombarded with great deals of risks, vulnerabilities, and unforeseen business interruptions in their lifetime, which negatively affect their productivity and sustainability within the market. Such risks require a risk management system to identify risks and risk factors and propose approaches to eliminate or reduce them. Risk management involves highly structured practices that should be implemented within an organization, including organizational planning documents. Continuity planning and fraud detection policy development are among the many critically important practices conducted through risk management that aim to mitigate risk factors, their vulnerability, and their impact. Information systems play a pivotal role in any organization by providing many benefits, such as reducing human errors and associated risks owing to the employment of sophisticated algorithms. Both the development and establishment of an information system within an organization contributes to mitigating business-related risks and also creates new types of risks associated with its establishment. Businesses must prepare for, react to, and recover from unprecedented threats that might emerge in the years or decades that follow.
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  • 15 Dec 2021
Topic Review
Wolf Distribution
Wolf distribution is the species distribution of the wolf (Canis lupus). Originally, wolves occurred in Eurasia above the 12th parallel north and in North America above the 15th parallel north. However, deliberate human persecution has reduced the species' range to about one-third, because of livestock predation and fear of wolf attacks on humans. The species is now extirpated (made locally extinct) in much of Western Europe, Mexico, and the contiguous United States , and completely from the British Isles and the Japanese archipelago. In modern history, the gray wolf occurs mostly in wilderness and remote areas, particularly in Canada , Alaska, the Northern United States, Europe and Asia from about the 75th parallel north to the 12th parallel north. Wolf population declines have been arrested since the 1970s, and have fostered recolonization and reintroduction in parts of its former range, due to legal protection, changes in land-use and rural human population shifts to cities. Competition with humans for livestock and game species, concerns over the danger posed by wolves to people, and habitat fragmentation pose a continued threat to the species. Despite these threats, because of the gray wolf's relatively widespread range and stable population, it is classified as Least Concern on the IUCN Red List. In Africa the population of wolves is limited to the northern regions with the African golden wolf (Canis lupaster) north of the Sahara and the Ethiopian wolf (Canis simensis) in Ethiopia.
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  • 25 Oct 2022
Topic Review
House of Bonaparte
The House of Bonaparte (originally Buonaparte) was an imperial and royal European dynasty founded in 1804 by Italian noble Carlo Buonaparte and his son Napoleon I, a French military leader of Italian heritage who had risen to notability out of the French Revolution and who in 1804 transformed the First French Republic into the First French Empire, five years after his coup d'état of November 1799. Napoleon turned the Grande Armée against every major European power and dominated continental Europe through a series of military victories during the Napoleonic Wars. He installed members of his family on the thrones of client states, extending the power of the dynasty. The House of Bonaparte formed the Imperial House of France during the French Empire, together with some non-Bonaparte family members. In addition to holding the title of Emperor of the French, the Bonaparte dynasty held various other titles and territories during the Napoleonic Wars, including their ancestral Kingdom of Italy, the Kingdom of Spain, the Kingdom of Westphalia, the Kingdom of Holland, and the Kingdom of Naples. The dynasty held power for around a decade until the Napoleonic Wars began to take their toll. Making very powerful enemies, such as Austria, Britain, Russia, and Prussia, as well as royalist (particularly Bourbon) restorational movements in France, Spain, the Two Sicilies, and Sardinia, the dynasty eventually collapsed due to the final defeat of Napoleon at the Battle of Waterloo and the restoration of former dynasties by the Congress of Vienna. During the reign of Napoleon I, the Imperial Family consisted of the Emperor's immediate relations – his wife, son, siblings, and some other close relatives, namely Joachim Murat, Joseph Fesch, and Eugène de Beauharnais. Between 1852 and 1870, there was a Second French Empire, when a member of the Bonaparte dynasty again ruled France: Napoleon III, the youngest son of Louis Bonaparte. However, during the Franco-Prussian War of 1870–1871, the dynasty was again ousted from the Imperial Throne. Since that time, there has been a series of pretenders. Supporters of the Bonaparte family's claim to the throne of France are known as Bonapartists. Current head Jean-Christophe, Prince Napoléon, has a Bourbon mother.
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  • 11 Nov 2022
Topic Review
Grade Retention
Grade retention is a strategy for the remediation of learning or developmental delays. Students who cannot keep up with their peers or do not meet a predefined level repeat the same grade once again and by doing so have an extra year to get at the level that is needed to successfully manage the next grade. There are considerable doubts as regards the usefulness and effectiveness of retaining grades. Studies conclude that in the short term retaining grades may have a positive effect on academic achievement, but that this gain disappears in the longer term.
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  • 30 Oct 2020
Topic Review
Role-Playing Games
Role-Playing Games may be defined as a system for creating stories based on rules. They allow a group of players and a game director (also known as Game Master or Narrator) to participate and interact using their imagination to determine what could happen. There are different kinds of Role-Playing Games (RPGs) that relate to video games and online video games. The original RPGs, sometimes called tabletop RPGs or pen-and-paper RPGs, were the starting point of their digital relatives, and used mainly speech and imagination; however, technology may be used in some cases for communication. RPGs that are played by writing posts in forums or sending emails are called Play by Post (PbP). Some RPGs even require live interaction, similar to theater representations; these are called Live Action Role Play (LARP).
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  • 17 Dec 2021
Topic Review
May 20: Vasco da Gama Reaches India
Vasco da Gama’s arrival in Calicut, India on May 20, 1498, marked the first time a European reached India by sea, successfully navigating around the Cape of Good Hope and across the Indian Ocean. This event opened a direct maritime trade route between Europe and Asia, breaking the centuries-old overland monopoly held by Middle Eastern and Venetian traders. It initiated an era of European exploration, imperial expansion, and global maritime dominance, especially for Portugal.
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  • 20 May 2025
Topic Review
Face with Tears of Joy Emoji
thumb|Appearance in the EmojiOne emoji set|167x167px Face with Tears of Joy (😂) is an emoji featuring a jovial face laughing, while also crying out tears. It can also be used for joking and teasing. It is the most commonly used emoji on social media websites such as Facebook, Snapchat, Twitter and Instagram. The emoji is also variously known as the lol emoji, joy emoji, laughing emoji or the laughing crying emoji.
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  • 09 Nov 2022
Topic Review
Basalt
Basalt (/bəˈsɔːlt, ˈbæsɒlt, -sɔːlt/) is a mafic extrusive igneous rock formed from the rapid cooling of magnesium-rich and iron-rich lava exposed at or very near the surface of a terrestrial planet or a moon. More than 90% of all volcanic rock on Earth is basalt. Basalt lava has a low viscosity, due to its low silica content, resulting in rapid lava flows that can spread over great areas before cooling and solidification. Flood basalt describes the formation in a series of lava basalt flows.
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  • 09 Nov 2022
Topic Review
Jojoba Oil
Jojoba is a widely used medicinal plant that is cultivated worldwide. Its seeds and oil have a long history of use in folklore to treat various ailments, such as skin and scalp disorders, superficial wounds, sore throat, obesity, and cancer; for improvement of liver functions, enhancement of immunity, and promotion of hair growth. Extensive studies on Jojoba oil showed a wide range of pharmacological applications, including antioxidant, anti-acne and antipsoriasis, anti-inflammatory, antifungal, antipyretic, analgesic, antimicrobial, and anti-hyperglycemia activities. In addition, Jojoba oil is widely used in the pharmaceutical industry, especially in cosmetics for topical, transdermal, and parenteral preparations. Jojoba oil also holds value in the industry as an anti-rodent, insecticides, lubricant, surfactant, and a source for the production of bioenergy. Jojoba oil is considered among the top-ranked oils due to its wax, which constitutes about 98% (mainly wax esters, few free fatty acids, alcohols, and hydrocarbons). In addition, sterols and vitamins with few triglyceride esters, flavonoids, phenolic and cyanogenic compounds are also present. 
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  • 03 Jun 2021
Topic Review
Word Processor (Electronic Device)
A word processor is an electronic device (later a computer software application) for text, composing, editing, formatting, and printing. The word processor was a stand-alone office machine in the 1960s, combining the keyboard text-entry and printing functions of an electric typewriter with a recording unit, either tape or floppy disk (as used by the Wang machine) with a simple dedicated computer processor for the editing of text. Although features and designs varied among manufacturers and models, and new features were added as technology advanced, the first word processors typically featured a monochrome display and the ability to save documents on memory cards or diskettes. Later models introduced innovations such as spell-checking programs, and improved formatting options. As the more versatile combination of personal computers and printers became commonplace, and computer software applications for word processing became popular, most business machine companies stopped manufacturing dedicated word processor machines. As of 2009 there were only two U.S. companies, Classic and AlphaSmart, which still made them.[needs update] Many older machines, however, remain in use. Since 2009, Sentinel has offered a machine described as a "word processor", but it is more accurately a highly specialised microcomputer used for accounting and publishing. Word processing was one of the earliest applications for the personal computer in office productivity, and was the most widely used application on personal computers until the World Wide Web rose to prominence in the mid-1990s. Although the early word processors evolved to use tag-based markup for document formatting, most modern word processors take advantage of a graphical user interface providing some form of what-you-see-is-what-you-get ("WYSIWYG") editing. Most are powerful systems consisting of one or more programs that can produce a combination of images, graphics and text, the latter handled with type-setting capability. Typical features of a modern word processor include multiple font sets, spell checking, grammar checking, a built-in thesaurus, automatic text correction, web integration, HTML conversion, pre-formatted publication projects such as newsletters and to-do lists, and much more. Microsoft Word is the most widely used word processing software according to a user tracking system built into the software. Microsoft estimates that roughly half a billion people use the Microsoft Office suite, which includes Word. Many other word processing applications exist, including WordPerfect (which dominated the market from the mid-1980s to early-1990s on computers running Microsoft's MS-DOS operating system, and still (2014) is favored for legal applications), Apple's Pages application, and open source applications such as OpenOffice.org Writer, LibreOffice Writer, AbiWord, KWord, and LyX. Web-based word processors such as Office Online or Google Docs are a relatively new category.
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  • 24 Nov 2022
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