You're using an outdated browser. Please upgrade to a modern browser for the best experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Human Eye Color
Eye color is a polygenic phenotypic character and is determined by the amount and type of pigments in the eye's iris. Humans and other animals have many phenotypic variations in eye color, as blue, brown, gray, green and others. These variations constitute phenotypic traits. The genetics of eye color are complicated, and color is determined by multiple genes. Some of the eye-color genes include EYCL1 (a green/blue eye-color gene located on chromosome 19), EYCL2 (a brown eye-color gene) and EYCL3 (a brown/blue eye-color gene located on chromosome 15). The once-held view that blue eye color is a simple recessive trait has been shown to be wrong. The genetics of eye color are so complex that almost any parent-child combination of eye colors can occur. In human eyes, these variations in color are attributed to varying ratios of eumelanin produced by melanocytes in the iris. The brightly colored eyes of many bird species are largely determined by other pigments, such as pteridines, purines, and carotenoids. Three main elements within the iris contribute to its color: the melanin content of the iris pigment epithelium, the melanin content within the iris stroma, and the cellular density of the iris stroma. In eyes of all colors, the iris pigment epithelium contains the black pigment, eumelanin. Color variations among different irides are typically attributed to the melanin content within the iris stroma. The density of cells within the stroma affects how much light is absorbed by the underlying pigment epithelium. OCA2 gene polymorphism, close to proximal 5′ regulatory region, explains most human eye-color variation.
  • 30.4K
  • 05 Dec 2022
Topic Review
Hyperinflation in Yugoslavia
Between 1992 and 1994, the Federal Republic of Yugoslavia (FRY) experienced the third-longest period of hyperinflation in world economic history. This period spanned 22 months, from March 1992 to January 1994. Inflation peaked at a monthly rate of 313 million percent in January 1994. Daily inflation was 62%, with an inflation rate of 2.03% in 1 hour being higher than the annual inflation rate of many developed countries. The inflation rate in January 1994, converted to annual levels, reached 116,545,906,563,330 percent (116.546 billion percent, or 1.16 × 1015 percent). During this period of hyperinflation in FR Yugoslavia, store prices were stated in conditional units – point, which was equal to the German mark. The conversion was made either in German marks or in dinars at the current "black market" exchange rate that often changed several times per day.
  • 30.3K
  • 14 Nov 2022
Topic Review
Northwestern European People
Northwestern European people are a pan-ethnic group, or multi-ethnic regional grouping, and the inhabitants of Northwestern Europe. Northwest or Northwestern Europeans can usually trace back full or partial heritage to Great Britain and Ireland, Northern Germany, Denmark , Sweden, Norway , the Netherlands, Northern France, Belgium, and other places connected to Northwestern Europe geographically or culturally. As the pan-ethnic group is also a cultural category, rather than exclusively geographical; it often can include peoples with ancestry from bordering regions such as Austria, Finland , Southern Germany, and Switzerland . There is a large Northwestern European diaspora, with significant numbers within North America (Northwestern European Americans and Northwestern European Canadians), and Northwestern European Australians in Oceania. Other subgroupings of Europeans include Eastern European people and Southern European people.
  • 30.1K
  • 28 Oct 2022
Topic Review
Financial Socialization Theory and Financial Information Literacy
Financial literacy entails possessing and applying financial management skills for efficient and effective financial resource management for individuals’ well-being. While financial literacy is concerned with the possession of adequate financial management skills, financial information literacy entails seeking and possessing adequate knowledge of the existence of financial products and services through diverse information channels.
  • 30.1K
  • 03 Nov 2025
Biography
Nasir Al-Din Al-Tusi
Muhammad ibn Muhammad ibn al-Hasan al-Tūsī (Persian: محمد ابن محمد ابن حسن طوسی‎ 18 February 1201 – 26 June 1274), better known as Nasir al-Din al-Tusi (Persian: نصیر الدین طوسی‎; or simply Tusi /ˈtuːsi/[1] in the West), was a Persian polymath, architect, philosopher, physician, scientist, and theologian.[2] Nasir al-Din al-Tusi was a well published a
  • 30.0K
  • 22 Nov 2022
Topic Review
Environmental Impact of Shipping
The environmental impact of shipping includes air pollution, water pollution, acoustic, and oil pollution. Ships are responsible for more than 18 percent of some air pollutants. It also includes greenhouse gas emissions. The International Maritime Organization (IMO) estimates that carbon dioxide emissions from shipping were equal to 2.2% of the global human-made emissions in 2012 and expects them to rise 50 to 250 percent by 2050 if no action is taken. There is a perception that cargo transport by ship is low in air pollutants, because for equal weight and distance it is the most efficient transport method, according to shipping researcher Alice Bows-Larkin. This is particularly true in comparison to air freight. However, because sea shipment accounts for far more annual tonnage and the distances are often large, shipping's emissions are globally substantial. A difficulty is that the annual increasing amount of shipping overwhelms gains in efficiency, such as from slow-steaming or the use of kites. The growth in tonne-kilometers of sea shipment has averaged 4 percent yearly since the 1990s, and it has grown by a factor of 5 since the 1970s. There are now over 100,000 transport ships at sea, of which about 6,000 are large container ships. The fact that shipping enjoys substantial tax privileges has contributed to the growing emissions.
  • 29.8K
  • 31 Oct 2022
Topic Review
Online Shopping
Online shopping is a form of electronic commerce which allows consumers to directly buy goods or services from a seller over the Internet using a web browser. Consumers find a product of interest by visiting the website of the retailer directly or by searching among alternative vendors using a shopping search engine, which displays the same product's availability and pricing at different e-retailers. As of 2016, customers can shop online using a range of different computers and devices, including desktop computers, laptops, tablet computers and smartphones. An online shop evokes the physical analogy of buying products or services at a regular "bricks-and-mortar" retailer or shopping center; the process is called business-to-consumer (B2C) online shopping. When an online store is set up to enable businesses to buy from another businesses, the process is called business-to-business (B2B) online shopping. A typical online store enables the customer to browse the firm's range of products and services, view photos or images of the products, along with information about the product specifications, features and prices. Online stores typically enable shoppers to use "search" features to find specific models, brands or items. Online customers must have access to the Internet and a valid method of payment in order to complete a transaction, such as a credit card, an Interac-enabled debit card, or a service such as PayPal. For physical products (e.g., paperback books or clothes), the e-tailer ships the products to the customer; for digital products, such as digital audio files of songs or software, the e-tailer typically sends the file to the customer over the Internet. The largest of these online retailing corporations are Alibaba, Amazon.com, and eBay.
  • 29.6K
  • 12 Oct 2022
Topic Review
Photo Manipulation
Photo manipulation involves transforming or altering a photograph using various methods and techniques to achieve desired results. Some photo manipulations are considered skillful artwork while others are frowned upon as unethical practices, especially when used to deceive the public. Other examples include being used for political propaganda, or to make a product or person look better, or simply for entertainment purposes or harmless pranks. Depending on the application and intent, some photo manipulations are considered an art form because it involves the creation of unique images and in some instances, signature expressions of art by photographic artists. For example, Ansel Adams employed some of the more common manipulations using darkroom exposure techniques, burning (darkening) and dodging (lightening) a photograph. Other examples of photo manipulation include retouching photographs using ink or paint, airbrushing, double exposure, piecing photos or negatives together in the darkroom, scratching instant films, or through the use of software-based manipulation tools applied to digital images. There are a number of software applications available for digital image manipulation, ranging from professional applications to very basic imaging software for casual users.
  • 29.6K
  • 08 Dec 2024
Topic Review
Chemtrail Conspiracy Theory
The chemtrail conspiracy theory posits the erroneous belief that long-lasting condensation trails are "chemtrails" consisting of chemical or biological agents left in the sky by high-flying aircraft, sprayed for nefarious purposes undisclosed to the general public. Believers in this conspiracy theory say that while normal contrails dissipate relatively quickly, contrails that linger must contain additional substances. Those who subscribe to the theory speculate that the purpose of the chemical release may be solar radiation management, weather modification, psychological manipulation, human population control, biological or chemical warfare, or testing of biological or chemical agents on a population, and that the trails are causing respiratory illnesses and other health problems. The claim has been dismissed by the scientific community. There is no evidence that purported chemtrails differ from normal water-based contrails routinely left by high-flying aircraft under certain atmospheric conditions. Although proponents have tried to prove that chemical spraying occurs, their analyses have been flawed or based on misconceptions. Because of the persistence of the conspiracy theory and questions about government involvement, scientists and government agencies around the world have repeatedly explained that the supposed chemtrails are in fact normal contrails. The term chemtrail is a portmanteau of the words chemical and trail, just as contrail is a portmanteau of condensation and trail.
  • 29.5K
  • 31 Oct 2022
Topic Review
Socialization
Despite the plethora of definitions of socialization, this process of formation of the social human is a key concept by allowing the interconnection between society and culture.
  • 28.9K
  • 30 Oct 2020
Topic Review
Counterculture of the 1960s
The counterculture of the 1960s refers to an anti-establishment cultural phenomenon that developed first in the United Kingdom (UK) and the United States (US) and then spread throughout much of the Western world between the mid-1960s and the mid-1970s, with London, New York City, and San Francisco being hotbeds of early countercultural activity. The aggregate movement gained momentum as the Civil Rights Movement continued to grow, and would later become revolutionary with the expansion of the U.S. government's extensive military intervention in Vietnam. As the 1960s progressed, widespread social tensions also developed concerning other issues, and tended to flow along generational lines regarding human sexuality, women's rights, traditional modes of authority, experimentation with psychoactive drugs, and differing interpretations of the American Dream. Many key movements related to these issues were born or advanced within the counterculture of the 1960s. As the era unfolded, new cultural forms and a dynamic subculture which celebrated experimentation, modern incarnations of Bohemianism, and the rise of the hippie and other alternative lifestyles, emerged. This embracing of creativity is particularly notable in the works of British Invasion bands such as The Beatles, and filmmakers whose works became far less restricted by censorship. In addition to the trendsetting Beatles, many other creative artists, authors, and thinkers, within and across many disciplines, helped define the counterculture movement. Several factors distinguished the counterculture of the 1960s from the anti-authoritarian movements of previous eras. The post-World War II "baby boom" generated an unprecedented number of potentially disaffected young people as prospective participants in a rethinking of the direction of American and other democratic societies. Post-war affluence allowed many of the counterculture generation to move beyond a focus on the provision of the material necessities of life that had preoccupied their Depression-era parents. The era was also notable in that a significant portion of the array of behaviors and "causes" within the larger movement were quickly assimilated within mainstream society, particularly in the US, even though counterculture participants numbered in the clear minority within their respective national populations. The counterculture era essentially commenced in earnest with the assassination of John F. Kennedy in November 1963. It became absorbed into the popular culture with the termination of US combat military involvement in Southeast Asia and the end of the draft in 1973, and ultimately with the resignation of President Richard Nixon in August 1974.
  • 28.6K
  • 25 Oct 2022
Topic Review
Malthusianism
Malthusianism is the idea that population growth is potentially exponential while the growth of the food supply or other resources is linear, which eventually reduces living standards to the point of triggering a population die off. This event, called a Malthusian catastrophe (also known as a Malthusian trap, population trap, Malthusian check, Malthusian crisis, Malthusian spectre, or Malthusian crunch) occurs when population growth outpaces agricultural production, causing famine or war, resulting in poverty and depopulation. Such a catastrophe inevitably has the effect of forcing the population (quite rapidly, due to the potential severity and unpredictable results of the mitigating factors involved, as compared to the relatively slow time scales and well-understood processes governing unchecked growth or growth affected by preventive checks) to "correct" back to a lower, more easily sustainable level. Malthusianism has been linked to a variety of political and social movements, but almost always refers to advocates of population control. These concepts derive from the political and economic thought of the Reverend Thomas Robert Malthus, as laid out in his 1798 writings, An Essay on the Principle of Population. Malthus suggested that while technological advances could increase a society's supply of resources, such as food, and thereby improve the standard of living, the resource abundance would enable population growth, which would eventually bring the per capita supply of resources back to its original level. Some economists contend that since the industrial revolution, mankind has broken out of the trap. Others argue that the continuation of extreme poverty indicates that the Malthusian trap continues to operate. Others further argue that due to lack of food availability coupled with excessive pollution, developing countries show more evidence of the trap. A similar, more modern concept, is that of human overpopulation. Neo-Malthusianism is the advocacy of human population planning to ensure resources and environmental integrities for current and future human populations as well as for other species. In Britain the term 'Malthusian' can also refer more specifically to arguments made in favour of preventive birth control, hence organizations such as the Malthusian League. Neo-Malthusians differ from Malthus's theories mainly in their support for the use of contraception. Malthus, a devout Christian, believed that "self-control" (i.e., abstinence) was preferable to artificial birth control. He also worried that the effect of contraceptive use would be too powerful in curbing growth, conflicting with the common 18th century perspective (to which Malthus himself adhered) that a steadily growing population remained a necessary factor in the continuing "progress of society", generally. Modern neo-Malthusians are generally more concerned than Malthus with environmental degradation and catastrophic famine than with poverty. Malthusianism has attracted criticism from diverse schools of thought, including Marxists and socialists, libertarians and free market enthusiasts, feminists and human rights advocates, characterising it as excessively pessimistic, misanthropic or inhuman. Many critics believe Malthusianism has been discredited since the publication of Principle of Population, often citing advances in agricultural techniques and modern reductions in human fertility. Many modern proponents believe that the basic concept of population growth eventually outstripping resources is still fundamentally valid, and that positive checks are still likely to occur in humanity's future if no action is taken to intentionally curb population growth. In spite of the variety of criticisms against it, the Malthusian argument remains a major discourse based on which national and international environmental regulations are promoted.
  • 28.5K
  • 10 Nov 2022
Topic Review
Oceania
Oceania (UK: /ˌoʊsiˈɑːniə, ˌoʊʃi-, -ˈeɪn-/, US: /ˌoʊʃiˈæniə/ (listen), /-ˈɑːn-/) is a geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern and Western hemispheres, Oceania is estimated to have a land area of 8,525,989 square kilometres (3,291,903 sq mi)[discuss] and a population of over 41 million. When compared with the other continents, the region of Oceania is the smallest in land area and the second smallest in population after Antarctica. Its six major population centres are Sydney, Melbourne, Brisbane, Perth, Auckland, and Adelaide. Oceania has a diverse mix of economies from the highly developed and globally competitive financial markets of Australia , French Polynesia, Hawaiʻi, New Caledonia, and New Zealand, which rank high in quality of life and Human Development Index, to the much less developed economies of Kiribati, Papua New Guinea, Tuvalu, Vanuatu, and Western New Guinea, while also including medium-sized economies of Pacific islands such as Fiji, Palau, and Tonga. The largest and most populous country in Oceania is Australia, and the largest city is Sydney. Puncak Jaya in Papua is the highest peak in Oceania at 4,884 m (16,024 ft). The first settlers of Australia, New Guinea, and the large islands just to the east arrived more than 60,000 years ago. Oceania was first explored by Europeans from the 16th century onward. Portuguese explorers, between 1512 and 1526, reached the Tanimbar Islands, some of the Caroline Islands and west Papua New Guinea. On his first voyage in the 18th century, James Cook, who later arrived at the highly developed Hawaiʻian Islands, went to Tahiti and followed the east coast of Australia for the first time. The arrival of European settlers in subsequent centuries resulted in a significant alteration in the social and political landscape of Oceania. The Pacific theatre saw major action during the Second World War, mainly between Allied powers the United States, Philippines (a US Commonwealth at the time) and Australia, and Axis power Japan. The rock art of Aboriginal Australians is the longest continuously practiced artistic tradition in the world. Most Oceanian countries are multi-party representative parliamentary democracies, with tourism being a large source of income for the Pacific Islands nations.
  • 28.5K
  • 03 Mar 2023
Topic Review
Invincible (Comics)
Invincible is an American comic book series written by Robert Kirkman, illustrated by Cory Walker and Ryan Ottley, and published by Image Comics. Set in the Image Universe, Invincible follows the coming of age of superhero Mark Grayson / Invincible, a Viltrumite and first-born son of Omni-Man, the most powerful person on the planet. The series began publication on January 22, 2003, concluding on February 14, 2018 with 144 issues. A television series adaptation began streaming on Amazon Prime Video on March 25, 2021 to critical acclaim.
  • 28.3K
  • 18 Oct 2022
Topic Review
Timoshenko-Ehrenfest Beam Theory
The Timoshenko-Ehrenfest beam theory was developed by Stephen Timoshenko and Paul Ehrenfest early in the 20th century. The model takes into account shear deformation and rotational bending effects, making it suitable for describing the behaviour of thick beams, sandwich composite beams, or beams subject to high-frequency excitation when the wavelength approaches the thickness of the beam. The resulting equation is of 4th order but, unlike Euler–Bernoulli beam theory, there is also a second-order partial derivative present. Physically, taking into account the added mechanisms of deformation effectively lowers the stiffness of the beam, while the result is a larger deflection under a static load and lower predicted eigenfrequencies for a given set of boundary conditions. The latter effect is more noticeable for higher frequencies as the wavelength becomes shorter (in principle comparable to the height of the beam or shorter), and thus the distance between opposing shear forces decreases. Rotary inertia effect was introduced by Bresse and Rayleigh. If the shear modulus of the beam material approaches infinity—and thus the beam becomes rigid in shear—and if rotational inertia effects are neglected, Timoshenko beam theory converges towards ordinary beam theory.
  • 27.9K
  • 20 Oct 2022
Topic Review
Tachypsychia
Tachypsychia is a neurological condition that alters the perception of time, usually induced by physical exertion, drug use, or a traumatic event. For someone affected by tachypsychia, time perceived by the individual either lengthens, making events appear to slow down, or contracts, objects appearing as moving in a speeding blur. It is believed that tachypsychia is induced by a combination of high levels of dopamine and norepinephrine, usually during periods of great physical stress or in violent confrontation. Interestingly, a controlled experiment from 2007 suggests the subjective experience of time slowing down is actually an artifact of memory, not an actual trait of real-time perception. However, newer research seems to contradict this, with results showing that during high stress events a focus on action preparation actually does increase information processing, slowing down time perception. A 2012 review of most current research (including the 2007 study) seems to support this as well. Due to the contradictory research results and difficulty of accurately replicating the natural conditions in which the phenomenon occurs, there is still no set consensus on how tachypsychia functions.
  • 27.6K
  • 07 Nov 2022
Topic Review
Photovoltaic Cell Generations
Solar energy is one of the most demanding renewable sources of electricity. Electricity production using photovoltaic technology not only helps meet the growing demand for energy, but also contributes to mitigating global climate change by reducing dependence on fossil fuels. The level of competitiveness of innovative next-generation solar cells is increasing due to the efforts of researchers and scientists related to the development of new materials, particularly nanomaterials and nanotechnology.
  • 27.4K
  • 25 Aug 2022
Topic Review
Bing (Search Engine)
Bing is a web search engine owned and operated by Microsoft. The service has its origins in Microsoft's previous search engines: MSN Search, Windows Live Search and later Live Search. Bing provides a variety of search services, including web, video, image and map search products. It is developed using ASP.NET. Bing, Microsoft's replacement for Live Search, was unveiled by Microsoft CEO Steve Ballmer on May 28, 2009, at the All Things Digital conference in San Diego, California, for release on June 3, 2009. Notable new features at the time included the listing of search suggestions while queries are entered and a list of related searches (called "Explore pane") based on semantic technology from Powerset, which Microsoft had acquired in 2008. In July 2009, Microsoft and Yahoo! announced a deal in which Bing would power Yahoo! Search. All Yahoo! Search global customers and partners made the transition by early 2012. The deal was altered in 2015, meaning Yahoo! was only required to use Bing for a "majority" of searches. In October 2011, Microsoft stated that they were working on new back-end search infrastructure with the goal of delivering faster and slightly more relevant search results for users. Known as "Tiger", the new index-serving technology had been incorporated into Bing globally since August that year. In May 2012, Microsoft announced another redesign of its search engine that includes "Sidebar", a social feature that searches users' social networks for information relevant to the search query. (As of October 2018), Bing is the third largest search engine globally, with a query volume of 4.58%, behind Google (77%) and Baidu (14.45%). Yahoo! Search, which Bing largely powers, has 2.63%.
  • 27.3K
  • 27 Oct 2022
Topic Review
Solaris (Operating System)
Solaris is a proprietary Unix operating system originally developed by Sun Microsystems. It superseded the company's earlier SunOS in 1993. In 2010, after the Sun acquisition by Oracle, it was renamed Oracle Solaris. Solaris is known for its scalability, especially on SPARC systems, and for originating many innovative features such as DTrace, ZFS and Time Slider. Solaris supports SPARC and x86-64 workstations and servers from Oracle and other vendors. Solaris is registered as compliant with the Single UNIX Specification. Historically, Solaris was developed as proprietary software. In June 2005, Sun Microsystems released most of the codebase under the CDDL license, and founded the OpenSolaris open-source project. With OpenSolaris, Sun wanted to build a developer and user community around the software. After the acquisition of Sun Microsystems in January 2010, Oracle decided to discontinue the OpenSolaris distribution and the development model. In August 2010, Oracle discontinued providing public updates to the source code of the Solaris kernel, effectively turning Solaris 11 back into a closed source proprietary operating system. Following that, OpenSolaris was forked as illumos and is alive through several illumos distributions. In 2011, the Solaris 11 kernel source code leaked to BitTorrent. However, through the Oracle Technology Network (OTN), industry partners can still gain access to the in-development Solaris source code. Solaris is developed under a proprietary development model, and only the source for open-source components of Solaris 11 is available for download from Oracle.
  • 27.1K
  • 18 Oct 2022
Topic Review
The Shaping of Social Media Algorithms on User Behavior
Social media has thus become an integral part of daily life for over two billion people all over the world. Social media apps such as Facebook, Instagram, and TikTok remain at the center of our interactions, information, entertainment, and connections. This widespread adoption is strongly attributed to content curation and delivery through complex algorithms that lie beneath the surface of each platform. These algorithms decide the content users are exposed to and self-learn from the interactions of the users on large volumes of data. Such a system of personalization has transformed how users engage with these platforms and facilitated the growth of social media platforms. However, the impact of these algorithms has only started to unveil how deeply they influence society. We must enhance this knowledge to fully appreciate the role of social media in society. This covers how algorithms inform users’ information diet, interaction patterns, purchase choices and even well-being.
  • 26.6K
  • 31 Oct 2024
  • Page
  • of
  • 2784
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of COVID-19
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Academic Video Service
Feedback