Your browser does not fully support modern features. Please upgrade for a smoother 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
Mechanism of Action of Thiazolidin-2,4-dione
The thiazolidin-2,4-dione (TZD) moiety plays a central role in the biological functioning of several essential molecules. The availability of substitutions at the third and fifth positions of the Thiazolidin-2,4-dione (TZD) scaffold makes it a highly utilized and versatile moiety that exhibits a wide range of biological activities.
  • 5.3K
  • 18 Oct 2022
Topic Review
Creativity
Creativity, historically known as The (World) Church of the Creator, is an atheistic ("nontheistic") white supremacist religious movement which espouses white separatism, antitheism, antisemitism, scientific racism, homophobia, and religious and philosophical naturalism. Creativity calls itself a "white racialist" religion and it has been classified as a hate group by the Southern Poverty Law Center and the Anti-Defamation League. It was founded in Lighthouse Point, Florida, United States, by Ben Klassen as the "Church of the Creator" in 1973, and now, it has a presence in several states of the US as well as Australia , Eastern Europe and the United Kingdom . Creativity is promoted by two organizations: the Creativity Alliance (CA also known as the Church of Creativity), and The Creativity Movement. The two groups have common origins, both being created in 2003 after Klassen's successor Matthew F. Hale (who had renamed the organisation New Church of the Creator), was arrested and sentenced to 40 years in prison. Purportedly, the worldview of Creativity is naturalistic and racialistic, based on its values which are the "survival, expansion and advancement of the White race", according to what the group classifies as the "eternal laws of nature, the experience of history, on logic and common sense". Members of the group believe in a "racial holy war" between "white and non-White races" (including Jews, black people and non-white people of "mixed race").
  • 5.3K
  • 14 Oct 2022
Topic Review
Vinca Leaves
Morphological and anatomical traits of the Vinca leaf were examined using microscopy techniques. Outdoor Vinca minor and V. herbacea plants and greenhouse cultivated V. major and V. major var. variegata plants had interspecific variations. All Vinca species leaves are hypostomatic. However, except for V. minor leaf, few stomata were also present on the upper epidermis. V. minor leaf had the highest stomatal index and V. major had the lowest, while the distribution of trichomes on the upper epidermis was species-specific. Differentiated palisade and spongy parenchyma tissues were present in all Vinca species’ leaves. However, V. minor and V. herbacea leaves had a more organized anatomical aspect, compared to V. major and V. major var. variegata leaves. Additionally, as a novelty, the cellular to intercellular space ratio of the Vinca leaf’s mesophyll was revealed herein with the help of computational analysis.
  • 5.3K
  • 06 Apr 2021
Topic Review
Cylinder Block
The cylinder block is an integrated structure comprising the cylinder(s) of a reciprocating engine and often some or all of their associated surrounding structures (coolant passages, intake and exhaust passages and ports, and crankcase). The term engine block is often used synonymously with "cylinder block" (although technically distinctions can be made between en bloc cylinders as a discrete unit versus engine block designs with yet more integration that comprise the crankcase as well). In the basic terms of machine elements, the various main parts of an engine (such as cylinder(s), cylinder head(s), coolant passages, intake and exhaust passages, and crankcase) are conceptually distinct, and these items can all be made as discrete pieces that are bolted together. Such construction was very widespread in the early decades of the commercialization of internal combustion engines (1880s to 1920s), and it is still sometimes used in certain applications where it remains advantageous (especially very large engines, but also some small engines). However, it is no longer the normal way of building most petrol engines and diesel engines, because for any given engine configuration, there are more efficient ways of designing for manufacture (and also for maintenance and repair). These generally involve integrating multiple machine elements into one discrete part, and doing the making (such as casting, stamping, and machining) for multiple elements in one setup with one machine coordinate system (of a machine tool or other piece of manufacturing machinery). This yields lower unit cost of production (and/or maintenance and repair). Today most engines for cars, trucks, buses, tractors, and so on are built with fairly highly integrated design, so the words "monobloc" and "en bloc" are seldom used in describing them; such construction is often implicit. Thus "engine block", "cylinder block", or simply "block" are the terms likely to be heard in the garage or on the street.
  • 5.3K
  • 28 Sep 2022
Topic Review
Hatha Yoga
Hatha yoga is a branch of Yoga, one of the six schools of Hinduism. The word haṭha literally means "force" and thus alludes to a system of physical techniques.:770:527 In India hatha yoga is associated in popular tradition with the 'Yogis' of the Natha Sampradaya through its mythical founder Matsyendranath. Matsyendranath, also known as Minanath or Minapa in Tibet, is celebrated as a saint in both Buddhist and Hindu tantric and hatha yoga schools. However, James Mallinson associates hatha yoga with the Dashanami Sampradaya and the mystical figure of Dattatreya. According to the Dattatreya Yoga Śastra, there are two forms of hatha yoga: one practiced by Yajñavalkya consisting of the eight limbs of ashtanga yoga and another practiced by Kapila consisting of eight mudras. Currently, the oldest dated text to describe hatha yoga, the Amṛtasiddhi, comes from a tantric Buddhist milieu. The oldest texts to use the actual verbiage of hatha are also Vajrayana Buddhist. In the 20th century, hatha yoga, particularly asanas (the physical postures), became popular throughout the world as a form of physical exercise, and is now colloquially termed simply as "yoga."
  • 5.3K
  • 24 Nov 2022
Topic Review
Plasma
Plasma (from grc πλάσμα (plásma) 'moldable substance') is one of the four fundamental states of matter. It contains a significant portion of charged particles – ions and/or electrons. The presence of these charged particles is what primarily sets plasma apart from the other fundamental states of matter. It is the most abundant form of ordinary matter in the universe, being mostly associated with stars, including the Sun. It extends to the rarefied intracluster medium and possibly to intergalactic regions. Plasma can be artificially generated by heating a neutral gas or subjecting it to a strong electromagnetic field. The presence of charged particles makes plasma electrically conductive, with the dynamics of individual particles and macroscopic plasma motion governed by collective electromagnetic fields and very sensitive to externally applied fields. The response of plasma to electromagnetic fields is used in many modern technological devices, such as plasma televisions or plasma etching. Depending on temperature and density, a certain amount of neutral particles may also be present, in which case plasma is called partially ionized. Neon signs and lightning are examples of partially ionized plasmas. Unlike the phase transitions between the other three states of matter, the transition to plasma is not well defined and is a matter of interpretation and context. Whether a given degree of ionization suffices to call a substance 'plasma' depends on the specific phenomenon being considered.
  • 5.3K
  • 25 Nov 2022
Topic Review
Carnitine in Mitochondrial Fatty Acid Transport and β-Oxidation
l-Carnitine is an amino acid derivative widely known for its involvement in the transport of long-chain fatty acids into the mitochondrial matrix, where fatty acid oxidation occurs. Moreover, l-Carnitine protects the cell from acyl-CoA accretion through the generation of acylcarnitines.
  • 5.3K
  • 11 Nov 2021
Topic Review
The Use of “Lifestyle” in Health Psychology
Lifestyle is a complex and often generic concept that has been used and defined in different ways in scientific research. There is no single definition of lifestyle, and various fields of knowledge have developed theories and research variables that are also distant from each other. In health psychology, the use of this concept has spread widely, especially in the preventive medicine sector, despite a definition that is not always precise and unambiguous. Indeed, it is often confused and assimilated to the health behaviours that have been defined as behavioural patterns, actions, and habits that relate to health maintenance, to health restoration and health improvement. There are two main definitions of lifestyles. The first one was formulated by the WHO, for which lifestyle is defined as “patterns of (behavioural) choices from the alternatives that are available to people according to their socio-economic circumstances and the ease with which they are able to choose certain ones over others”. The second major definition of lifestyle formulated by Cockerham is “collective patterns of health-related behaviour based on choices from options available to people according to their life chances”.
  • 5.3K
  • 09 Mar 2023
Topic Review
Japanese River Otter
The Japanese river otter (Japanese: ニホンカワウソ(日本川獺 ー, Hepburn: Nihon-kawauso) (Lutra lutra whiteleyi) is an extinct variety of otter formerly widespread in Japan. Dating back to the 1880s, it was even seen in Tokyo. The population suddenly shrank in the 1930s, and the mammal nearly vanished. Since then, it has only been spotted several times, in 1964 in the Seto Inland Sea, and in the Uwa Sea in 1972 and 1973. The last official sighting was in the southern part of Kōchi Prefecture in 1979, when it was photographed in the mouth of the Shinjo River in Susaki. It was subsequently classified as a "Critically Endangered" species on the Japanese Red List. On August 28, 2012, the Japanese river otter was officially declared extinct by the Ministry of the Environment. It is the official animal symbol of Ehime Prefecture. In February 2017, a wild otter was caught on camera on Tsushima Island, Nagasaki Prefecture. However, it is not known whether the observed otter was a Japanese river otter.
  • 5.3K
  • 18 Oct 2022
Topic Review
List of German Aircraft Projects, 1939–45
The aircraft in this list include prototype versions of aircraft used by the German Luftwaffe during World War II and unfinished wartime experimental programmes. In the former, development can stretch back to the 1920s and in the latter the project must have started between 1939-1945.
  • 5.3K
  • 14 Oct 2022
Topic Review
Observer Effect
In physics, the observer effect is the disturbance of an observed system by the act of observation. This is often the result of instruments that, by necessity, alter the state of what they measure in some manner. A common example is checking the pressure in an automobile tire; this is difficult to do without letting out some of the air, thus changing the pressure. Similarly, seeing non-luminous objects requires light hitting the object, and causing it to reflect that light. While the effects of observation are often negligible, the object still experiences a change. This effect can be found in many domains of physics, but can usually be reduced to insignificance by using different instruments or observation techniques. A notable example of the observer effect occurs in quantum mechanics, as demonstrated by the double-slit experiment. Physicists have found that observation of quantum phenomena can change the measured results of this experiment. Despite the "observer effect" in the double-slit experiment being caused by the presence of an electronic detector, the experiment's results have been misinterpreted by some to suggest that a conscious mind can directly affect reality. The need for the "observer" to be conscious is not supported by scientific research, and has been pointed out as a misconception rooted in a poor understanding of the quantum wave function ψ and the quantum measurement process.
  • 5.3K
  • 29 Nov 2022
Topic Review
List of Intel Pentium 4 Microprocessors
The Pentium 4 microprocessor from Intel is a seventh-generation CPU targeted at the consumer market.
  • 5.3K
  • 02 Oct 2022
Topic Review Peer Reviewed
Geometric Design of Suburban Roundabouts
A modern roundabout is an intersection with a circulatory roadway at which the vehicle speed is low, and the traffic is continuous and circulating in one direction around the central island towards the exits at the approach legs. Modern roundabout design is an iterative process that is composed of the following steps: (1) the identification of the roundabout as the optimal traffic solution; (2) the definition of the number of lanes at the intersection based on the required capacity and the level of service; (3) the initial design of the roundabout geometry; (4) design vehicle swept path, the fastest path analysis, and visibility performance checks; and (5) detailed roundabout design if the results of the performance checks are in line with the design recommendations. Initial roundabout geometry design elements are not independent of each other; therefore, care must be taken to provide compatibility between them. An overview and a comparative analysis of the initial geometric design elements for suburban single-lane roundabouts defined in roundabout design guidelines and norms used in Croatia, Austria, France, the Netherlands, Germany, Serbia, and Switzerland is given in this entry.
  • 5.3K
  • 13 Apr 2022
Topic Review
Lane Detection and Tracking
Lane detection and tracking are the advanced key features of the advanced driver assistance system. Lane detection is the process of detecting white lines on the roads. Lane tracking is the process of assisting the vehicle to remain in the desired path, and it controls the motion model by using previously detected lane markers.
  • 5.3K
  • 25 Oct 2021
Topic Review
Sabot
A sabot (UK: /sæˈboʊ, ˈsæboʊ/, US: /ˈseɪboʊ/) is a structural device used in firearm or cannon ammunition to keep a sub-caliber flight projectile, such as a relatively small bullet or arrow-type projectile, in the center of the barrel when fired, if the bullet has a significantly smaller diameter than the bore diameter of the weapon used. The sabot component in projectile design is more than simply the relatively thin, tough and deformable seal known as a driving band or obturation ring needed to trap propellant gases behind a projectile, and also keep the projectile centered in the barrel, when the outer shell of the projectile is only slightly smaller in diameter than the caliber of the barrel. Driving bands and obturators are used to seal these full-bore projectiles in the barrel because of manufacturing tolerances; there always exists some gap between the projectile outer diameter and the barrel inner diameter, usually a few thousandths of an inch; enough of a gap for high pressure gasses to slip by during firing. Driving bands and obturator rings are made from material that will deform and seal the barrel as the projectile is forced from the chamber into the barrel. Small caliber jacketed bullets do not normally employ driving bands or obturators because the jacket material, for example copper or gilding metal, is deformable enough to serve that function, and the bullet is made slightly larger than the barrel for that purpose, (see full metal jacket bullet and driving band). Sabots certainly use driving bands and obturators, because the same manufacturing tolerance issues exist when sealing the saboted projectile in the barrel, but the sabot itself is a more substantial structural component of the in-bore projectile configuration (Drysdale 1978). Refer to the two APFSDS (armor-piercing fin-stabilized discarding sabot) pictures on the right to see the substantial material nature of a sabot to fill the bore diameter around the sub-caliber arrow-type flight projectile, compared to the very small gap sealed by a driving band or obturator to mitigate what is known classically as windage. More detailed cutaways of the internal structural complexity of advanced APFSDS saboted long rod penetrator projectiles can be found at reference 2.
  • 5.3K
  • 27 Oct 2022
Topic Review
Passive Constant Flow Regulators
Passive flow control regulators, also known as passive flow control or autoregulated or pressure-compensated valves, deliver, without external control and energy consumption, a constant flow rate regardless of pressure variations.
  • 5.3K
  • 22 Dec 2020
Topic Review
Bahá'í Faith on Life after Death
The Bahá'í Faith affirms the prospect of life after death extensively while not defining everything about it. The soul on death is said to recognize the value of its deeds and begin a new phase of a conscious relationship with God though negative experiences are possible. Others have noted the religion's stances on the afterlife.
  • 5.3K
  • 22 Nov 2022
Topic Review
Internet Pornography
Internet pornography is any pornography that is accessible over the internet, primarily via websites, FTP servers peer-to-peer file sharing, or Usenet newsgroups. The availability of widespread public access to the World Wide Web in late 1990s led to the growth of internet pornography. A 2015 study finds "a big jump" in pornography viewing over the past few decades, with the largest increase occurring between people born in the 1970s and those born in the 1980s. While the study's authors note this increase is "smaller than conventional wisdom might predict," it's still quite significant. Those who were born in the 1980s onward are also the first to grow up in a world where they have access to the internet beginning in their teenage years, and this early exposure and access to internet pornography may be the primary driver of the increase. The sex and tech conference series Arse Elektronika dedicated their 2007 conference to what they call pr0nnovation. The con presented a keynote by culture theorist Mark Dery and published a reader about the subject. (As of 2018), a single company, MindGeek, owns and operates many popular pornographic websites, including video sharing services Pornhub, RedTube, and YouPorn, as well as adult film producers Brazzers, Digital Playground, Men.com, Reality Kings, and Sean Cody, among others, but does not own the websites xHamster and XVideos. It has been alleged to be a monopoly.
  • 5.3K
  • 25 Oct 2022
Topic Review
Loopholes in Bell Tests
In Bell tests, there may be problems of experimental design or set-up that affect the validity of the experimental findings. These problems are often referred to as "loopholes". See the article on Bell's theorem for the theoretical background to these experimental efforts (see also John Stewart Bell). The purpose of the experiment is to test whether nature is best described using a local hidden-variable theory or by the quantum entanglement theory of quantum mechanics. The "detection efficiency", or "fair sampling" problem is the most prevalent loophole in optical experiments. Another loophole that has more often been addressed is that of communication, i.e. locality. There is also the "disjoint measurement" loophole which entails multiple samples used to obtain correlations as compared to "joint measurement" where a single sample is used to obtain all correlations used in an inequality. To date, no test has simultaneously closed all loopholes. Ronald Hanson of the Delft University of Technology claims the first Bell experiment that closes both the detection and the communication loopholes. (This was not an optical experiment in the sense discussed below; the entangled degrees of freedom were electron spins rather than photon polarization.) Nevertheless, correlations of classical optical fields also violate Bell's inequality. In some experiments there may be additional defects that make "local realist" explanations of Bell test violations possible; these are briefly described below. Many modern experiments are directed at detecting quantum entanglement rather than ruling out local hidden-variable theories, and these tasks are different since the former accepts quantum mechanics at the outset (no entanglement without quantum mechanics). This is regularly done using Bell's theorem, but in this situation the theorem is used as an entanglement witness, a dividing line between entangled quantum states and separable quantum states, and is as such not as sensitive to the problems described here. In October 2015, scientists from the Kavli Institute of Nanoscience reported that the quantum nonlocality phenomenon is supported at the 96% confidence level based on a "loophole-free Bell test" study. These results were confirmed by two studies with statistical significance over 5 standard deviations which were published in December 2015. However, Alain Aspect writes that No experiment can be said to be totally loophole-free.
  • 5.3K
  • 31 Oct 2022
Topic Review
Big Three TV Networks
In the United States , there are three major traditional commercial broadcast television networks - CBS (Columbia Broadcasting System), NBC (National Broadcasting Company), and ABC (American Broadcasting Company) - that due to their longevity and ratings success are referred to as the "Big Three", which dominated American television until the 1990s, and are still considered major U.S. broadcast companies.
  • 5.3K
  • 08 Oct 2022
  • Page
  • of
  • 2798
Featured Entry Collections
>>

Featured Reprints

>>
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Medieval Royal Iconography
Academic Video Service
Feedback