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Topic Review
Product Distribution
A product distribution is a probability distribution constructed as the distribution of the product of random variables having two other known distributions. Given two statistically independent random variables X and Y, the distribution of the random variable Z that is formed as the product is a product distribution.
  • 7.6K
  • 11 Nov 2022
Topic Review
Reindeer Distribution
The reindeer is a widespread and numerous species in the northern Holarctic, being present in both tundra and taiga (boreal forest). Originally, the reindeer was found in Scandinavia, eastern Europe, Russia , Mongolia, and northern China north of the 50th latitude. In North America, it was found in Canada , Alaska (United States ), and the northern contiguous USA from Washington to Maine. In the 19th century, it was apparently still present in southern Idaho. It also occurred naturally on Sakhalin, Greenland, and probably even in historical times in Ireland. During the late Pleistocene era, reindeer were found further south, such as at Nevada, Tennessee , and Alabama in North America and Spain in Europe. Today, wild reindeer have disappeared from many areas within this large historical range, especially from the southern parts, where it vanished almost everywhere. Populations of wild reindeer are still found in Norway , Finland , Siberia, Greenland, Alaska, and Canada . Domesticated reindeer are mostly found in northern Fennoscandia and Russia, with a herd of approximately 150–170 semi-domesticated reindeer living around the Cairngorms region in Scotland. The last remaining wild tundra reindeer in Europe are found in portions of southern Norway . A few reindeer from Norway were introduced to the South Atlantic island of South Georgia in the beginning of the 20th century. The South Georgian reindeer totaled some estimated 2600 animals in two distinct herds separated by glaciers. Although the flag and the coat of arms of the territory contain an image of a reindeer, they were eradicated from 2013 to 2017 because of the environmental damage they caused. Around 4000 reindeer have been introduced into the French sub-Antarctic archipelago of Kerguelen Islands. East Iceland has a small herd of about 2500–3000 animals. Caribou and reindeer numbers have fluctuated historically, but many herds are in decline across their range. This global decline is linked to climate change for northern, migratory caribou and reindeer herds and industrial disturbance of caribou habitat for sedentary, non-migratory herds.
  • 7.5K
  • 28 Nov 2022
Topic Review
Medium-Voltage Switchgear Condition Monitoring
Switchgear are a key component of the electrical grid. They serve both protective and control roles in distribution electric power with in the grid. It is therefore important to monitor and predict the condition of these assets. Thereby, condition monitoring is divided into three main tasks: breaker drive monitoring, thermal monitoring and partial discharge monitoring. This encyclopedia article provides an overview of the potential failure modes and monitoring techniques. More details can be found in an exhaustive review article, cited below.
  • 7.5K
  • 29 Oct 2020
Topic Review
Skin-Lightening Active Ingredients in Japan
Japanese pharmaceutical cosmetics, often referred to as quasi-drugs, contain skin-lightening active ingredients formulated to prevent sun-induced pigment spots and freckles. Their mechanisms of action include suppressing melanin production in melanocytes and promoting epidermal growth to eliminate melanin more rapidly. For example, arbutin and rucinol are representative skin-lightening active ingredients that inhibit melanin production, and disodium adenosine monophosphate and dexpanthenol are skin-lightening active ingredients that inhibit melanin accumulation in the epidermis. In contrast, oral administration of vitamin C and tranexamic acid in pharmaceutical products can lighten freckles and melasma, and these products are more effective than quasi-drugs. On the basis of their clinical effectiveness, skin-lightening active ingredients can be divided into four categories according to their effectiveness and adverse effects.
  • 7.5K
  • 08 Aug 2022
Topic Review
Direct Contact Condensers
Direct contact heat exchangers can be smaller, cheaper, and have simpler construction than the surface, shell, or tube heat exchangers of the same capacity and can operate in evaporation or condensation modes. For these reasons, they have many practical applications, such as water desalination, heat exchangers in power plants, or chemical engineering devices.
  • 7.5K
  • 23 Dec 2022
Topic Review
Tin Can
A tin can, tin (especially in British English, Australian English and Canadian English), steel can, steel packaging or a can, is a container for the distribution or storage of goods, composed of thin metal. Many cans require opening by cutting the "end" open; others have removable covers. Cans hold diverse contents: foods, beverages, oil, chemicals, etc. Steel cans are made of tinplate (tin-coated steel) or of tin-free steel. In some dialects, even aluminium cans are called "tin cans".
  • 7.5K
  • 26 Oct 2022
Topic Review
History of Solar System Formation and Evolution Hypotheses
The history of scientific thought about the Formation and evolution of the Solar System begins with the Copernican Revolution. The first recorded use of the term "Solar System" dates from 1704.
  • 7.5K
  • 22 Nov 2022
Topic Review
Stanford Web Credibility Project
The Stanford Web Credibility Project, which involves assessments of website credibility conducted by the Stanford University Persuasive Technology Lab, is an investigative examination of what leads people to believe in the veracity of content found on the Web. The goal of the project is to enhance website design and to promote further research on the credibility of Web resources.
  • 7.5K
  • 09 Nov 2022
Topic Review
Impulse Buying Behavior in Fast Fashion Physical Stores
The health crisis caused by COVID-19 has affected consumption and payment patterns worldwide. Consumers have had to change their habits and deal with new sanitation guidelines and have often struggled with lengthy infrastructure closures. These factors significantly influenced both the choice of payment methods and purchase decisions made by consumers. Still, consumption patterns during the pandemic as a new social situation have not yet been thoroughly investigated. 
  • 7.5K
  • 22 Apr 2022
Topic Review
Friends with Benefits Relationships
Friends with benefits relationships (FWB or FWBR) is a term commonly used to reference a relationship that is sexual without being romantic. Typically, these relationships can be between people that consider themselves platonic friends without pressure. These non-committal relationships can be short term, or evolve into serious romantic relationships. In an era of increased sexual liberation, casual sexual relationships continue to become more prominent. Studies show an increasing number of college students, both male and female, report having a friends with benefits relationship at some point. FWB relationships are enjoyed by both women and men, this is in contrast to casual sexual encounters which are more prevalent among men.
  • 7.5K
  • 27 Oct 2022
Topic Review
(ε, δ)-Definition of Limit
In calculus, the (ε, δ)-definition of limit ("epsilon–delta definition of limit") is a formalization of the notion of limit. The concept is due to Augustin-Louis Cauchy, who never gave a formal (ε, δ) definition of limit in his Cours d'Analyse, but occasionally used ε, δ arguments in proofs. It was first given as a formal definition by Bernard Bolzano in 1817, and the definitive modern statement was ultimately provided by Karl Weierstrass. It provides rigor to the following informal notion: the dependent expression f(x) approaches the value L as the variable x approaches the value c if f(x) can be made as close as desired to L by taking x sufficiently close to c.
  • 7.5K
  • 22 Nov 2022
Topic Review
An Insight into Psychedelic Drugs in Schizophrenia
Schizophrenia remains a serious chronic mental illness since its revelation more than a century ago by Dr. Emile Kraepelin. Despite the low prevalence, nearly 24 million people suffer from this disorder, which constitutes 1 in 300 people (0.32%) of the world’s population and this rate is 1 in 222 people (0.45%) among adults. The symptoms of schizophrenia more often appear in the second or third decade of life, and disease occurrence is tied to a combination of factors such as genetic, socio-demographic, and environmental factor. Clinical schizophrenia is presented in two unique and distinct sets of symptomatology, which include ‘positive’ symptoms and ‘negative’ symptoms, and is also accompanied by significant impairment of cognitive functioning in one or more major areas. This may include an inability to execute work, interpersonal relations, or self-care, and there is also a failure to achieve the expected level of interpersonal, academic, or occupational functioning. According to the current Diagnostic and Statistical Manual for mental disorders-V (DSM-V), the positive symptoms of schizophrenia are delusions, hallucinations, disorganized speech, and behaviour; and the negative symptoms are diminished emotional expression or avolitio. These symptoms have been found to be chronically present once the disease starts, but generally the illness is marked as alternate signs of remission and exacerbation or partial remission or exacerbation. Some psychotic symptoms may be treated without the need for medication with proper human care, social support and care including electroconvulsive therapy.
  • 7.5K
  • 08 Jun 2022
Topic Review
Broadcasting of Sports Events
The broadcasting of sports events (also known as a sportscast) is the live coverage of sports as a television program, on radio, and other broadcasting media. It usually involves one or more sports commentators describing events as they happen.
  • 7.5K
  • 01 Dec 2022
Topic Review
E-learning (Theory)
E-learning theory describes the cognitive science principles of effective multimedia learning using electronic educational technology.
  • 7.5K
  • 25 Nov 2022
Topic Review
Cultural Heritage and Tourism
The integration of the cultural/creative and tourism industries is one way to present different types of regional cultural heritage to the world. With the growth of scenic towns and the revitalization of rural areas due to mass tourism, intangible cultural heritage has become an important tourism and cultural resource. The numbers of domestic and foreign tourists visiting these traditional cultural resources are on the rise every year. Many areas with rich cultural resources rely on tourism to alleviate poverty and achieve revitalization. However, a region’s tourism resources are not always proportional to its cultural heritage. It is important to carefully study the methods of regional tourism resource development, while also fully integrating cultural resources.
  • 7.5K
  • 30 Jun 2022
Topic Review
6 February 1934 Crisis
The 6 February 1934 crisis was an anti-parliamentarist street demonstration in Paris organized by multiple far-right leagues that culminated in a riot on the Place de la Concorde, near the seat of the French National Assembly. The police shot and killed 15 demonstrators. It was one of the major political crises during the Third Republic (1870–1940). Frenchmen on the left feared it was an attempt to organize a fascist coup d'état. According to historian Joel Colton, "The consensus among scholars is that there was no concerted or unified design to seize power and that the leagues lacked the coherence, unity, or leadership to accomplish such an end." As a result of the actions of that day, several anti-fascist organisations were created, such as the Comité de vigilance des intellectuels antifascistes, in an attempt to thwart the rise of fascism in France. After World War II, several historians, among them Serge Berstein, argued that while some leagues had been indisputably pushing for a coup, François de La Rocque had, in fact, turned in a liberal direction, toward a respect for constitutional order. However, if the lack of coordination among the fascist leagues undermined the idea of a fascist conspiracy, the fascist actions on 6 February were an uncoordinated but violent attempt to overthrow the Cartel des gauches government elected in 1932. Édouard Daladier, who was president of the Council of Ministers, replaced Camille Chautemps on 27 January 1934 because of accusations of corruption (including the Stavisky Affair). Daladier, who had been a popular figure, was nonetheless forced to resign on 7 February. He was replaced by the conservative Gaston Doumergue as head of the government; this was the first time during the tenure of the Third Republic a government fell because of pressures from the street.
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  • 21 Nov 2022
Topic Review
Intercropping
Intercropping ensures multiple benefits like enhancement of yield, environmental security, production sustainability and greater ecosystem services. In intercropping, two or more crop species are grown concurrently such that they coexist for a significant part of the crop cycle and interact among themselves and with agro-ecosystems.
  • 7.5K
  • 09 Jan 2022
Topic Review
Precambrian Supereon
The Precambrian (or Pre-Cambrian, sometimes abbreviated pЄ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian (colored green in the timeline figure) is an informal unit of geologic time, subdivided into three eons (Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago (Ga) to the beginning of the Cambrian Period, about 541 million years ago (Ma), when hard-shelled creatures first appeared in abundance.
  • 7.5K
  • 18 Oct 2022
Topic Review
Hockey Stick Controversy
In the hockey stick controversy, the data and methods used in reconstructions of the temperature record of the past 1000 years have been disputed. Reconstructions have consistently shown that the rise in the instrumental temperature record of the past 150 years is not matched in earlier centuries, and the name "hockey stick graph" was coined for figures showing a long-term decline followed by an abrupt rise in temperatures. These graphs were publicised to explain the scientific findings of climatology, and in addition to scientific debate over the reconstructions, they have been the topic of political dispute. The issue is part of the global warming controversy and has been one focus of political responses to reports by the Intergovernmental Panel on Climate Change (IPCC). Arguments over the reconstructions have been taken up by fossil fuel industry–funded lobbying groups attempting to cast doubt on climate science. The use of proxy indicators to get quantitative estimates of the temperature record of past centuries was developed from the 1990s onwards, and found indications that recent warming was exceptional. The Bradley & Jones 1993 reconstruction introduced the "Composite Plus Scaling" (CPS) method used by most later large-scale reconstructions, and its findings were disputed by Patrick Michaels at the United States House Committee on Science. In 1998, Michael E. Mann, Raymond S. Bradley and Malcolm K. Hughes developed new statistical techniques to produce Mann, Bradley & Hughes 1998 (MBH98), the first eigenvector-based climate field reconstruction (CFR). This showed global patterns of annual surface temperature, and included a graph of average hemispheric temperatures back to 1400. In Mann, Bradley & Hughes 1999 (MBH99) the methodology was extended back to 1000. The term hockey stick was coined by the climatologist Jerry D. Mahlman, to describe the pattern this showed, envisaging a graph that is relatively flat to 1900 as forming an ice hockey stick's "shaft", followed by a sharp increase corresponding to the "blade". A version of this graph was featured prominently in the 2001 IPCC Third Assessment Report (TAR), along with four other reconstructions supporting the same conclusion. The graph was publicised, and became a focus of dispute for those opposed to the strengthening scientific consensus that late 20th-century warmth was exceptional. Those disputing the graph included Pat Michaels, the George C. Marshall Institute and Fred Singer. A paper by Willie Soon and Sallie Baliunas claiming greater medieval warmth was used by the Bush administration chief of staff Philip Cooney to justify altering the first Environmental Protection Agency Report on the Environment. The paper was quickly dismissed by scientists in the Soon and Baliunas controversy, but on July 28, Republican Jim Inhofe spoke in the Senate citing it to claim "that man-made global warming is the greatest hoax ever perpetrated on the American people". Later in 2003, a paper by Steve McIntyre and Ross McKitrick disputing the data used in MBH98 paper was publicised by the George C. Marshall Institute and the Competitive Enterprise Institute. In 2004, Hans von Storch published criticism of the statistical techniques as tending to underplay variations in earlier parts of the graph, though this was disputed and he later accepted that the effect was very small. In 2005, McIntyre and McKitrick published criticisms of the principal component analysis methodology as used in MBH98 and MBH99. The analysis therein was subsequently disputed by published papers, including Huybers 2005 and Wahl & Ammann 2007, which pointed to errors in the McIntyre and McKitrick methodology. In June 2005, Rep. Joe Barton launched what Sherwood Boehlert, chairman of the House Science Committee, called a "misguided and illegitimate investigation" into the data, methods and personal information of Mann, Bradley and Hughes. At Boehlert's request, a panel of scientists convened by the National Research Council was set up, which reported in 2006, supporting Mann's findings with some qualifications, including agreeing that there were some statistical failings but these had little effect on the result. Barton and U.S. Rep. Ed Whitfield requested Edward Wegman to set up a team of statisticians to investigate, and they supported McIntyre and McKitrick's view that there were statistical failings, although they did not quantify whether there was any significant effect. They also produced an extensive network analysis which has been discredited by expert opinion and found to have issues of plagiarism. Arguments against the MBH studies were reintroduced as part of the Climatic Research Unit email controversy, but dismissed by eight independent investigations. More than two dozen reconstructions, using various statistical methods and combinations of proxy records, have supported the broad consensus shown in the original 1998 hockey-stick graph, with variations in how flat the pre-20th century "shaft" appears. The 2007 IPCC Fourth Assessment Report cited 14 reconstructions, 10 of which covered 1,000 years or longer, to support its strengthened conclusion that it was likely that Northern Hemisphere temperatures during the 20th century were the highest in at least the past 1,300 years. Over a dozen subsequent reconstructions, including Mann et al. 2008 and PAGES 2k Consortium 2013, have supported these general conclusions.
  • 7.5K
  • 21 Oct 2022
Topic Review
Seismometer
A seismometer is an instrument that responds to ground motions, such as caused by earthquakes, volcanic eruptions, and explosions. Seismometers are usually combined with a timing device and a recording device to form a seismograph. The output of such a device—formerly recorded on paper (see picture) or film, now recorded and processed digitally—is a seismogram. Such data is used to locate and characterize earthquakes, and to study the Earth's internal structure.
  • 7.5K
  • 01 Dec 2022
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