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
Tourism Commercialization and Perceived Authenticity
The concept of authenticity is closely related to heritage tourism, especially cultural heritage tourism. Seeking authenticity is one of the main trends in heritage tourism because people want to identify and understand themselves or reminisce about the past by looking back to the old ways of life and cultural traditions. Compared with actual authenticity, perceived authenticity has more value. It is a bridge between heritage authenticity and tourist experience. Heritage tourism is essentially a form of tourism that attracts tourists based on the commercialization of historical and cultural assets. A heritage site not only draws tourists to experience the authentic past, but it also provides them with a place for entertainment, relaxation and consumption. That is, heritage tourism development inevitably encounters commercialization. From a demand perspective, heritage tourism is an emotional experience, the perception of tourists at its core.
  • 11.0K
  • 22 Jun 2021
Topic Review
Synthesis and Properties of Pyrazoles
Pyrazole derivatives are a special class of N-heterocyclic compounds (NHCps) bearing a heteroaromatic five-membered ring with two adjacent nitrogen atoms in the annular structure, one pyrrole-type (proton donor) and one pyridine-type (proton acceptor). Pyrazoles can act as weak bases or acids, with possible strength highly dependent on the nature of their substituent groups. The other three positions in the ring permit structural variants starting from the appropriate precursors or using post-functionalization reactions once the pyrazole ring is formed; these variations give the pyrazoles diverse and valuable synthetical, biological, and photophysical properties; indeed, more complex structures with various relevant examples can be formed from them.
  • 11.0K
  • 09 Sep 2022
Topic Review
Jews
Jews (Hebrew: יְהוּדִים‎ ISO 259-2 Yehudim, Israeli pronunciation [jehuˈdim]) or Jewish people are members of an ethnoreligious group and a nation originating from the Israelites and Hebrews of historical Israel and Judah. Jewish ethnicity, nationhood, and religion are strongly interrelated, as Judaism is the ethnic religion of the Jewish people, although its observance varies from strict to none. Jews originated as an ethnic and religious group in the Middle East during the second millennium BCE, in the part of the Levant known as the Land of Israel. The Merneptah Stele appears to confirm the existence of a people of Israel somewhere in Canaan as far back as the 13th century BCE (Late Bronze Age). The Israelites, as an outgrowth of the Canaanite population, consolidated their hold with the emergence of the kingdoms of Israel and Judah. Some consider that these Canaanite sedentary Israelites melded with incoming nomadic groups known as 'Hebrews'. Though few sources mention the exilic periods in detail, the experience of diaspora life, from the Babylonian captivity and exile to the Roman occupation and exile, and the historical relations between Jews and their homeland thereafter, became a major feature of Jewish history, identity and memory. In the millennia following, Jewish diaspora communities coalesced into three, major ethnic subdivisions according to where their ancestors settled: Ashkenazim (Central and Eastern Europe), Sephardim (initially in the Iberian Peninsula), and Mizrahim (Middle East and North Africa). Prior to World War II, the worldwide Jewish population reached a peak of 16.7 million, representing around 0.7 percent of the world population at that time. Approximately 6 million Jews were systematically murdered during the Holocaust. Since then the population has slowly risen again, and (As of 2018) was estimated at 14.6–17.8 million by the Berman Jewish DataBank, less than 0.2 percent of the total world population.[note 1] The modern State of Israel is the only country where Jews form a majority of the population. It defines itself as a Jewish and democratic state in the Basic Laws, Human Dignity and Liberty in particular, which is based on the Declaration of Independence. Israel's Law of Return grants the right of citizenship to Jews who have expressed their desire to settle in Israel. Despite their small percentage of the world's population, Jews have significantly influenced and contributed to human progress in many fields, both historically and in modern times, including philosophy, ethics, literature, politics, business, fine arts and architecture, music, theatre and cinema, medicine, and science and technology, as well as religion; Jews authored the Bible, founded Early Christianity and had a profound influence on Islam. Jews have also played a significant role in the development of Western Civilization.
  • 11.0K
  • 21 Nov 2022
Topic Review
Paper
Paper is a thin material produced by pressing together moist fibres of cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets. It is a versatile material with many uses, including writing, printing, packaging, cleaning, decorating, and a number of industrial and construction processes. Papers are essential in legal or non-legal documentation. The pulp papermaking process is said to have been developed in China during the early 2nd century CE, possibly as early as the year 105 CE, by the Han court eunuch Cai Lun, although the earliest archaeological fragments of paper derive from the 2nd century BCE in China. The modern pulp and paper industry is global, with China leading its production and the United States right behind it.
  • 11.0K
  • 30 Oct 2022
Topic Review
Olefins Production via Steam Cracking:Effect of Operating Parameters
Various parameters need to be considered to optimize a pyrolysis reactor for the production of ethylene and propylene. These parameters are included temperature, residence time, steam-to-hydrocarbon ratio, and feedstock composition. A higher reaction temperature results in a higher yield of ethylene, a shorter residence time, and higher reaction velocities. A low operating pressure is preferred for this process because of the gas phase reaction inside the reactor tubes and the production of more gaseous molecules for its reactions to the right. The reactor pressure must be kept as low as possible (between 170 and 250 kPa). The gas pressure in the reactor tube outlet is indirectly adjusted by the suction process gas pressure of the compressor in the compression section, downstream of the process. As mentioned earlier, to reach lower hydrocarbon pressures, process steam is co-fed with the hydrocarbon feed to reduce the hydrocarbon partial pressure and lower coke deposition. The addition of steam decreases the partial pressure of the hydrocarbon feed and favors the formation of primary products.
  • 11.0K
  • 16 Dec 2021
Topic Review
Social Construct Theory of ADHD
The social construction theory of ADHD argues that attention deficit hyperactivity disorder is not necessarily an actual pathology, but that an ADHD diagnosis is a socially constructed explanation to describe behaviors that simply do not meet prescribed social norms. Some proponents of the social construct theory of ADHD seem to regard the disorder as genuine, though over-diagnosed in some cultures. These proponents cite as evidence that the DSM IV, favored in the United States for defining and diagnosing mental illness, arrives at levels of ADHD three to four times higher than criteria in the ICD 10, the diagnostic guide favored by the World Health Organization. A popular proponent of this theory, Thomas Szasz, has argued that ADHD was "invented and not discovered."
  • 11.0K
  • 22 Nov 2022
Biography
Kevin Systrom
Kevin York Systrom (born December 30, 1983)[1] is an American entrepreneur and programmer, best known as the co‑founder of Instagram along with Mike Krieger. Systrom was born in 1983 in Holliston, Massachusetts. He is the son of Diane (Pels), a marketing executive at Zipcar, who also worked at Monster and Swapit during the first dotcom bubble,[2] and Douglas Systrom, Vice President in Human
  • 11.0K
  • 30 Nov 2022
Topic Review
Structure and Physiological Activities of Anthocyanins
Anthocyanidin is a kind of water-soluble natural pigment that widely exists in natural plants. Like other natural flavonoids, anthocyanin has a C6-C3-C6 carbon skeleton. Due to the different carbon substituents (-OH, -OCH3) on the B ring, different types of anthocyanins were derived. The six common anthocyanins were Pelargonidin (Pg), Cyanidin (Cy), Delphinidin (Dp), Peonidin (Pn), Petunidin (Pt), and Malvidin (Mv). In addition to giving food a variety of bright colors, anthocyanin also has important biological activities, such as antioxidant, anti-inflammatory, and anti-aging effects, among others. A large number of studies have shown that dietary anthocyanins have a good preventive effect on cardiovascular diseases.
  • 11.0K
  • 01 Aug 2022
Topic Review
Penn State Child Sex Abuse Scandal
The Penn State child sex abuse scandal concerned allegations and subsequent convictions of child sexual abuse committed by Jerry Sandusky, an assistant coach for the Penn State Nittany Lions football team, over a period of at least fifteen years. The scandal began to emerge publicly in March 2011 and broke in early November 2011 when Sandusky was indicted on 52 counts of child molestation, stemming from incidents that occurred between 1994 and 2009. Sandusky was ultimately convicted on 45 counts of child sexual abuse on June 22, 2012, and was sentenced to a minimum of 30 years and a maximum of 60 years in prison. Additionally, three Penn State officials – school president Graham Spanier, vice president Gary Schultz and athletic director Tim Curley – were charged with perjury, obstruction of justice, failure to report suspected child abuse, and related charges. The Penn State Board of Trustees commissioned an independent investigation by former FBI Director Louis Freeh, whose report stated that Penn State's longtime head football coach Joe Paterno, along with Spanier, Curley and Schultz, had known about allegations of child abuse by Sandusky as early as 1998, had shown "total and consistent disregard...for the safety and welfare of Sandusky's child victims", and "empowered" Sandusky to continue his acts of abuse by failing to disclose them.:14 Shortly after the scandal broke, Spanier resigned. The Board of Trustees terminated the contracts of Paterno and Curley. As a result of the scandal, the National Collegiate Athletic Association (NCAA) imposed sanctions on the Penn State football program: a $60 million fine, a four-year postseason ban, scholarship reductions, and a vacation of all victories from 1998 to 2011. These sanctions were considered to be among the most severe ever imposed on an NCAA member school. NCAA President Mark Emmert stated that the sanctions were levied "not to be just punitive, but to make sure the university establishes an athletic culture and daily mindset in which football will never again be placed ahead of educating, nurturing and protecting young people." The Big Ten Conference subsequently imposed an additional $13 million fine. The Paterno family retained former Attorney General Richard Thornburgh to conduct a review of the Freeh report, which concluded that the report constituted a "rush to injustice" that could not be relied upon and that Freeh's evidence fell "far short" of showing that Joe Paterno attempted to conceal the scandal, but rather that "the contrary is true". In January 2013, state senator Jake Corman and state treasurer Rob McCord sued the NCAA, seeking to overturn the Penn State sanctions on the basis that Freeh had been actively collaborating with the organization and that due process had not been followed. In November 2014, Corman released emails showing "regular and substantive" contact between Freeh's investigators and the NCAA, suggesting that Freeh's conclusions were orchestrated. As part of a settlement, the NCAA restored the 111 wins to Paterno's record on January 16, 2015. On March 25, 2017, Curley, Schultz, and Spanier pleaded or were found guilty of misdemeanor charges of child endangerment. All conspiracy charges against Curley and Schultz were dropped, and Spanier was acquitted of conspiracy, the charges central to Louis Freeh's allegation of a cover-up. In June 2017, all three were sentenced to jail terms, fines, and probation for the misdemeanors. Spanier was sentenced to four to twelve months in jail, a $7,500 fine, and two years of probation. Spanier's misdemeanor conviction was subsequently overturned on appeal.
  • 11.0K
  • 25 Oct 2022
Topic Review
Cheilitis
Cheilitis is a medical condition characterized by inflammation of the lips. The inflammation may include the perioral skin (the skin around the mouth), the vermilion border, or the labial mucosa. The skin and the vermilion border are more commonly involved, as the mucosa is less affected by inflammatory and allergic reactions. Cheilitis is a general term, and there are many recognized types and different causes. According to its onset and course, cheilitis can be either acute or chronic. Most cheilitis is caused by exogenous factors such as dryness (chapping) and acute sun exposure. Allergic tests may identify allergens that cause cheilitis.
  • 11.0K
  • 25 Nov 2022
Topic Review
Venus in Culture
Venus, as one of the brightest objects in the sky, has been known since prehistoric times and has been a major fixture in human culture for as long as records have existed. As such, it has a prominent position in human culture, religion, and myth. It has been made sacred to gods of many cultures, and has been a prime inspiration for writers and poets as the morning star and evening star.
  • 11.0K
  • 14 Nov 2022
Topic Review
Libertarian Marxism
Libertarian Marxism is a broad scope of economic and political philosophies that emphasize the anti-authoritarian and libertarian aspects of Marxism. Early currents of libertarian Marxism such as left communism emerged in opposition to Marxism–Leninism. Libertarian Marxism is often critical of reformist positions such as those held by social democrats. Libertarian Marxist currents often draw from Karl Marx and Friedrich Engels' later works, specifically the Grundrisse and The Civil War in France; emphasizing the Marxist belief in the ability of the working class to forge its own destiny without the need for a vanguard party to mediate or aid its liberation. Along with anarchism, libertarian Marxism is one of the main currents of libertarian socialism. Libertarian Marxism includes currents such as autonomism, council communism, De Leonism, Lettrism, parts of the New Left, Situationism, Socialisme ou Barbarie and workerism. Libertarian Marxism has often had a strong influence on both post-left and social anarchists. Notable theorists of libertarian Marxism have included Maurice Brinton, Cornelius Castoriadis, Guy Debord, Raya Dunayevskaya, Daniel Guérin, C. L. R. James, Rosa Luxemburg, Antonio Negri, Anton Pannekoek, Fredy Perlman, Ernesto Screpanti, E. P. Thompson, Raoul Vaneigem and Yanis Varoufakis, who claims that Marx himself was a libertarian Marxist.
  • 11.0K
  • 11 Nov 2022
Topic Review
Pinophyta
The Pinophyta, also known as Coniferophyta or Coniferae, or commonly as conifers, are a division of vascular land plants containing a single extant class, Pinopsida. They are gymnosperms, cone-bearing seed plants. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include cedars, Douglas firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews. As of 1998, the division Pinophyta was estimated to contain eight families, 68 genera, and 629 living species. Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, but also in similar cool climates in mountains further south. Boreal conifers have many wintertime adaptations. The narrow conical shape of northern conifers, and their downward-drooping limbs, help them shed snow. Many of them seasonally alter their biochemistry to make them more resistant to freezing. While tropical rainforests have more biodiversity and turnover, the immense conifer forests of the world represent the largest terrestrial carbon sink. Conifers are of great economic value for softwood lumber and paper production.
  • 11.0K
  • 21 Oct 2022
Topic Review
Information Problem-Solving Instruction
Information problem solving (IPS) is a complex cognitive process considered as an important 21st century skill in combination with critical thinking [15].
  • 10.9K
  • 27 Oct 2020
Topic Review
Last Glacial Period
The last glacial period occurred from the end of the Eemian interglacial to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. This most recent glacial period is part of a larger pattern of glacial and interglacial periods known as the Quaternary glaciation extending from c. 2,588,000 years ago to present. The definition of the Quaternary as beginning 2.58 Ma is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Ma, in the mid-Cenozoic (Eocene–Oligocene extinction event). The term Late Cenozoic Ice Age is used to include this early phase. During this last glacial period there were alternating episodes of glacier advance and retreat. Within the last glacial period the Last Glacial Maximum was approximately 22,000 years ago. While the general pattern of global cooling and glacier advance was similar, local differences in the development of glacier advance and retreat make it difficult to compare the details from continent to continent (see picture of ice core data below for differences). Approximately 13,000 years ago, the Late Glacial Maximum began. The end of the Younger Dryas about 11,700 years ago marked the beginning of the Holocene geological epoch, which includes the Holocene glacial retreat. From the point of view of human archaeology, the last glacial period falls in the Paleolithic and early Mesolithic periods. When the glaciation event started, Homo sapiens were confined to lower latitudes and used tools comparable to those used by Neanderthals in western and central Eurasia and by Homo erectus in Asia. Near the end of the event, Homo sapiens migrated into Eurasia and Australia. Archaeological and genetic data suggest that the source populations of Paleolithic humans survived the last glacial period in sparsely wooded areas and dispersed through areas of high primary productivity while avoiding dense forest cover. The retreat of the glaciers 15,000 years ago allowed groups of humans from Asia to migrate to the Americas.
  • 10.9K
  • 21 Oct 2022
Topic Review
Context-Dependent Memory
In psychology, context-dependent memory is the improved recall of specific episodes or information when the context present at encoding and retrieval are the same. In a simpler manner, "when events are represented in memory, contextual information is stored along with memory targets; the context can therefore cue memories containing that contextual information". One particularly common example of context-dependence at work occurs when an individual has lost an item (e.g. lost car keys) in an unknown location. Typically, people try to systematically "retrace their steps" to determine all of the possible places where the item might be located. Based on the role that context plays in determining recall, it is not at all surprising that individuals often quite easily discover the lost item upon returning to the correct context. This concept is heavily related to the encoding specificity principle. This example best describes the concept of context-dependent forgetting. However, the research literature on context-dependent memory describes a number of different types of contextual information that may affect recall such as environmental context-dependent memory, state-dependent learning, cognitive context-dependent memory and mood-congruent memory. Research has also shown that context-dependence may play an important role in numerous situations, such as memory for studied material, or events that have occurred following the consumption of alcohol or other drugs.
  • 10.9K
  • 03 Nov 2022
Biography
Sabrina Gonzalez Pasterski
Sabrina Gonzalez Pasterski (born June 3, 1993) is an American theoretical physicist from Chicago who studies high energy physics.[1] She describes herself as "a proud first-generation Cuban-American & Chicago Public Schools alumna."[2] She completed her undergraduate studies at the Massachusetts Institute of Technology (MIT), earned her PhD from Harvard University and is a rising PCTS Postdoctor
  • 10.9K
  • 12 Dec 2022
Topic Review
Almond Kernel
This entry is about Non-Lipid Components and Minor Fat-Soluble Bioactive Compounds of Almond Kernel.
  • 10.9K
  • 08 Dec 2020
Topic Review
Karōshi
Karōshi (過労死), which can be translated literally as "overwork death" in Japanese, is occupational sudden mortality. The major medical causes of karōshi deaths are heart attack and stroke due to stress and a starvation diet. This phenomenon is also widespread in other parts of Asia as well.
  • 10.9K
  • 21 Nov 2022
Topic Review
Information and Communication Technology (ICT) in Construction
Information and communication technology (ICT) is one of the important factors that support construction project performance. 
  • 10.9K
  • 28 Mar 2022
  • Page
  • of
  • 2838
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