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Topic Review
Pulmonary Artery Catheter
Pulmonary artery catheterization (PAC), or right heart catheterization, is the insertion of a catheter into a pulmonary artery. Its purpose is diagnostic; it is used to detect heart failure or sepsis, monitor therapy, and evaluate the effects of drugs. The pulmonary artery catheter allows direct, simultaneous measurement of pressures in the right atrium, right ventricle, pulmonary artery, and the filling pressure ("wedge" pressure) of the left atrium. The pulmonary artery catheter is frequently referred to as a Swan-Ganz catheter, in honor of its inventors Jeremy Swan and William Ganz, from Cedars-Sinai Medical Center.
  • 5.2K
  • 24 Nov 2022
Topic Review
Blockchain and Machine Learning for Future Smart Grids
A wide range of solutions, beyond the classical one of building more lines, cables and transformers, have been proposed to modernize the power grid with new technologies, enabling a more smart automatic networked system. These solutions, typically using new technology, go by the name “smart grids” (SG) or “smart-grid technology”. Blockchain technology (BC) is a viable solution to overcome the issues of centralized system. BC is an immutable, distributed and P2P network that provides security, privacy and trust among peers using cryptographic techniques. Machine learning (ML) techniques can be exploited to develop energy prediction algorithms and the proper scheduling of energy usage. A large amount of the energy consumption data of several users is generated from smart meters that also contain users’ private/confidential information as well as sensitive information of utility providers. This high volume of data increases the complexity of data analysis. 
  • 5.2K
  • 27 Feb 2023
Topic Review
Irritator
Irritator is a genus of spinosaurid dinosaur that lived in what is now Brazil during the Albian stage of the Early Cretaceous Period, about 113 to 110 million years ago. It is known from a nearly complete skull found in the Romualdo Formation of the Araripe Basin. Fossil dealers had acquired this skull and sold it to the State Museum of Natural History Stuttgart. In 1996, the specimen became the holotype of the type species Irritator challengeri. The genus name comes from the word "irritation", reflecting the feelings of paleontologists who found the skull had been heavily damaged and altered by the collectors. The species name is a homage to the fictional character Professor Challenger from Arthur Conan Doyle's novels. Some paleontologists regard Angaturama limai—known from a snout tip that was described later in 1996—as a potential junior synonym of Irritator. Both animals hail from the same stratigraphic units of the Araripe Basin. It was also previously proposed that Irritator and Angaturama's skull parts belonged to the same specimen. Although this has been cast into doubt, more overlapping fossil material is needed to confirm whether they are the same animal or not. Other spinosaurid skeletal material, some of which could belong to Irritator or Angaturama, was retrieved from the Romualdo Formation, allowing for a replica skeleton to be made and mounted for display at the National Museum of Rio de Janeiro in 2009. Estimated at between 6 and 8 meters (20 and 26 ft) in length, Irritator weighed around 1 tonne (1.1 short tons), making it one of the smallest spinosaurids known. Its long, shallow and slender snout was lined with straight and unserrated conical teeth. Lengthwise atop the head ran a thin sagittal crest, to which powerful neck muscles were likely anchored. The nostrils were positioned far back from the tip of the snout, and a rigid secondary palate on the roof of the mouth would have strengthened the jaw when feeding. Belonging to a subadult, Irritator challengeri's holotype remains the most completely preserved spinosaurid skull yet found. The Angaturama snout tip expanded to the sides in a rosette-like shape, bearing long teeth and an unusually tall crest. One possible skeleton indicates it, like other spinosaurids, had enlarged first-finger claws and a sail running down its back. Irritator had been mistaken initially for a pterosaur, and later a maniraptoran dinosaur. In 1996, the animal was identified as a spinosaurid theropod. The holotype skull was thoroughly prepared before being redescribed in 2002, confirming this classification. Both Irritator and Angaturama belong to the Spinosaurinae subfamily. A generalist diet—like that of today's crocodilians—has been suggested; Irritator might have preyed mainly on fish and any other small prey animals it could catch. Fossil evidence is known of an individual that ate a pterosaur, either from hunting or scavenging it. Irritator may have had semiaquatic habits, and inhabited the tropical environment of a coastal lagoon surrounded by dry regions. It coexisted with other carnivorous theropods as well as turtles, crocodyliforms, and a large number of pterosaur and fish species.
  • 5.2K
  • 03 Nov 2022
Topic Review
Chi square statistic
The Chi-Square test is based on a series of assumptions frequently used in the statistical analysis of experimental data. The main weakness of the chi-square test is that is very accurate only in convergence (in large size samples), and for small sample sizes is exposed to errors of both types (type I and type II). On two scenarios of use - goodness of fit and contingencies assessment (2x2 tables of contingency) - here are discussed different aspects involving it. Further knowledge on the regard of the type of the error in contingencies assessment push further the analysis of the data, while in the same time opens the opportunity to devise a method for filling the gaps in contingencies (e.g. censored data), both scenarios being discussed here in detail. A program designed to fill the gaps in the assumption of the association is provided.
  • 5.2K
  • 24 Dec 2020
Topic Review
Biodiesel from Castor Oil
An attractive alternative to the use of fossil fuels is biodiesel, which can be obtained from a variety of feedstock through different transesterification systems such as ultrasound, microwave, biological, chemical, among others. The efficient and cost-effective biodiesel production depends on several parameters such as free fatty acid content in the feedstock, transesterification reaction efficiency, alcohol: oil ratio, catalysts type, and several parameters during the production process. However, biodiesel production from vegetable oils is under development, causing the final price of biodiesel to be higher than diesel derived from petroleum. An alternative to decrease the production costs will be the use of economical feedstocks and simple production processes. Castor oil is an excellent raw material in terms of price and quality, but especially this non-edible vegetable oil does not have any issues or compromise food security. Recently, the use of castor oil has attracted attention for producing and optimizing biodiesel production, due to the high content of ricinoleic fatty acid and the possibility to esterify with only methanol, which assures low production costs. Additionally, biodiesel from castor oil has different advantages over conventional diesel. Some of them are biodegradable, non-toxic, renewable, they can be used alone, low greenhouse gas emission, among others. This review discusses and analyzes different transesterification processes, technologies, as well as different technical aspects during biodiesel production using castor oil as a feedstock.
  • 5.2K
  • 28 Oct 2020
Topic Review
Republic
A republic (Latin: res publica, meaning "public affair") is a form of government in which the country is considered a "public matter", not the private concern or property of the rulers. The primary positions of power within a republic are attained, through democracy, oligarchy, or a mix thereof, rather than being unalterably occupied. It has become the opposing form of government to a monarchy and has therefore no monarch as head of state. (As of 2017), 159 of the world's 206 sovereign states use the word "republic" as part of their official names – not all of these are republics in the sense of having elected governments, nor is the word "republic" used in the names of all nations with elected governments. The word republic comes from the Latin term res publica, which literally means "public thing", "public matter", or "public affair" and was used to refer to the state as a whole. The term developed its modern meaning in reference to the constitution of the ancient Roman Republic, lasting from the overthrow of the kings in 509 BC to the establishment of the Empire in 27 BC. This constitution was characterized by a Senate composed of wealthy aristocrats and wielding significant influence; several popular assemblies of all free citizens, possessing the power to elect magistrates and pass laws; and a series of magistracies with varying types of civil and political authority. Most often a republic is a single sovereign state, but there are also sub-sovereign state entities that are referred to as republics, or that have governments that are described as "republican" in nature. For instance, Article IV of the United States Constitution "guarantee[s] to every State in this Union a Republican form of Government". Another example is the Soviet Union which described itself as being a group of "Soviet Socialist Republics", in reference to the 15 individually federal, multinational, top-level subdivisions or republics. In the context of American constitutional law, the definition of republic refers specifically to a form of government in which elected individuals represent the citizen body and exercise power according to the rule of law under a constitution, including separation of powers with an elected head of state, referred to as a constitutional republic or representative democracy.
  • 5.2K
  • 16 Nov 2022
Topic Review
British Sheep Breed Diversity
The UK can be proud of the fact that numerous native breeds of sheep have been developed here that possess unique phenotypic features and excellent productivity and are utilized throughout the world. Their remarkable popularity and further sustainable breeding on grass pastures of British Isles and elsewhere can benefit from genomic applications. At present, there is a rich arsenal of genetic and genomic resources, tools and applications used for livestock assessment, breeding and production including, first of all, genetic profiling of diverse breeds, and search for quantitative trait loci (QTLs) and candidate genes in farm animals. These genomic advances facilitate breed improvement and understanding of the genetic processes in the course of domestication and breed evolution.
  • 5.1K
  • 27 Feb 2024
Topic Review
List of Meteor Air Bursts
Many explosions recorded in Earth's atmosphere are likely to be caused by the air bursts that result from meteors exploding as they hit the thicker part of the atmosphere. These types of meteors are also known as fireballs or bolides with the brightest known as superbolides. Before entering Earth's atmosphere, these larger meteors were originally asteroids and comets of a few to several tens of metres in diameter, contrasting with the much smaller and much more common "shooting stars". The most powerful recorded air burst is the 1908 Tunguska event. Extremely bright fireballs traveling across the sky are often witnessed from a distance, such as the 1947 Sikhote-Alin meteor and the 2013 Chelyabinsk meteor, both in Russia. If the bolide is large enough, fragments may survive such as the Chelyabinsk meteorite. Modern developments in infrasound detection by the Comprehensive Nuclear-Test-Ban Treaty Organization and infrared Defense Support Program satellite technology have increased the likelihood of detecting airbursts.
  • 5.1K
  • 11 Nov 2022
Topic Review
N-Acetylcysteine
Exercise frequently alters the metabolic processes of oxidative metabolism in athletes, including exposure to extreme reactive oxygen species impairing exercise performance. Therefore, both researchers and athletes have been consistently investigating the possible strategies to improve metabolic adaptations to exercise-induced oxidative stress. N-acetylcysteine (NAC) has been applied as a therapeutic agent in treating many diseases in humans due to its precursory role in the production of hepatic glutathione, a natural antioxidant.
  • 5.1K
  • 03 Feb 2021
Topic Review
Vanillin Production from Lignin
Vanillin, one of the most widely used and appreciated flavoring agents worldwide, is the main constituent of vanilla bean extract, obtained from the seed pods of various members belonging to the Orchidaceae family. Due to the great demand in the food confectionery industry, as well as in the perfume industry, medicine, and more, the majority of vanillin used today is produced synthetically, and only less than one percent of the world’s vanilla flavoring market comes directly from the traditional natural sources. The increasing global demand for vanillin requires alternative and overall sustainable new production methods, and the recovery from biobased polymers, like lignin, is an environmentally friendly alternative to chemical synthesis. 
  • 5.1K
  • 01 Feb 2024
Topic Review
Thin-Film Magnetoelastic Materials Based Devices
Thin-film magnetoelastic materials, which couple the magnetization and strain together, have recently attracted ever-increasing attention due to their key roles in magnetoelectric applications. This review starts with the fabrication and characterization techniques in the field of magnetoelastic materials and introduces various kinds of devices utilizing ME effect.
  • 5.1K
  • 04 Nov 2020
Topic Review
Faster-Than-Light Communication
Superluminal communication is a hypothetical process in which information is sent at faster-than-light (FTL) speeds. The current scientific consensus is that faster-than-light communication is not possible, and to date it has not been achieved in any experiment. Under present knowledge superluminal communication is impossible because, in a Lorentz-invariant theory, it could be used to transmit information into the past. This contradicts causality and leads to logical paradoxes. A number of theories and phenomena related to superluminal communication have been proposed or studied, including tachyons, quantum nonlocality, and wormholes.
  • 5.1K
  • 19 Oct 2022
Topic Review
Impact of the Internet on Hip Hop
The World Wide Web has changed the genre of hip hop. It has given hip-hop artists the ability to create and share music at incredible rates. Through the constant influx of new music being posted online by artists, new styles and genres of hip hop have been created.
  • 5.1K
  • 30 Nov 2022
Topic Review
Yandex Self-Driving Car
Yandex self-driving car (Yandex Self-Driving Group) is a robotaxi project of the Russian-based internet corporation Yandex. The first driverless prototype launched in May 2017. As of 2018, functional service was launched in Russia with prototypes also being tested in Israel and the US. In 2019, Yandex revealed autonomous delivery robots based on the same technology stack as the company's self-driving cars. Since 2020, autonomous robots have been delivering food, groceries and parcels in Russia and the USA. In 2020, the self-driving project was spun-off into a standalone company under the name of Yandex Self-Driving Group (Yandex SDG).
  • 5.1K
  • 27 Oct 2022
Topic Review
Ottoman Decline Thesis
The Ottoman decline thesis or Ottoman decline paradigm (Turkish: Osmanlı Gerileme Tezi) is an obsolete historical narrative which once played a dominant role in the study of the history of the Ottoman Empire. According to the decline thesis, following a golden age associated with the reign of Sultan Suleiman the Magnificent (r. 1520–1566), the empire gradually entered into a period of all-encompassing stagnation and decline from which it was never able to recover, lasting until the dissolution of the Ottoman Empire in 1923. This thesis was used throughout most of the twentieth century as the basis of both Western and Republican Turkish understanding of Ottoman history. However, by 1978, historians had begun to reexamine the fundamental assumptions of the decline thesis. After the publication of numerous new studies throughout the 1980s, 1990s, and 2000s, and the reexamination of Ottoman history through the use of previously untapped sources and methodologies, academic historians of the Ottoman Empire achieved a consensus that the entire notion of Ottoman decline was a myth – that in fact, the Ottoman Empire did not stagnate or decline at all, but rather continued to be a vigorous and dynamic state long after the death of Suleiman the Magnificent. The decline thesis has been criticized as "teleological", "regressive", "Orientalist", "simplistic", and "one-dimensional", and described as "a concept which has no place in historical analysis". Scholars have thus "learned better than to discuss [it]." Despite this dramatic paradigm shift among professional historians, the decline thesis continues to maintain a strong presence in popular history, as well as academic history written by scholars who are not specialists on the Ottoman Empire. In some cases this is due to the continued reliance by non-specialists on outdated and debunked works, and in others to certain political interests benefiting from the continued perpetuation of the decline narrative.
  • 5.1K
  • 22 Nov 2022
Topic Review
Dilophosauridae
Dilophosauridae is a family of medium to large sized theropod dinosaurs. The name Dilophosauridae is derived from Greek, with “di-” meaning “two,” “lophos” meaning “crest,” “sauros” meaning “lizard,” and “-idae” meaning “family”. While the name suggests that all dilophosaurids have two crests, this is not applicable to all dilophosaurids. The Dilophosauridae is anchored by its type genus, Dilophosaurus, and therefore the name comes from the distinctive two crests of the genus.
  • 5.1K
  • 24 Oct 2022
Topic Review
Tuskegee Syphilis Experiment
The Tuskegee Study of Untreated Syphilis in the African American Male was a clinical study conducted between 1932 and 1972 by the United States Public Health Service. The purpose of this study was to observe the natural history of untreated syphilis; the African-American men in the study were only told they were receiving free health care from the Federal government of the United States. The Public Health Service started the study in 1932 in collaboration with Tuskegee University (then the Tuskegee Institute), a historically black college in Alabama. Investigators enrolled in the study a total of 600 impoverished, African-American sharecroppers from Macon County, Alabama. Of these men, 399 had latent syphilis, with a control group of 201 men who were not infected. As an incentive for participation in the study, the men were promised free medical care, but were deceived by the PHS, who disguised placebos, ineffective methods, and diagnostic procedures as treatment. The men who had syphilis were never informed of their diagnosis, despite the risk of infecting others, and the fact that the disease could lead to blindness, deafness, mental illness, heart disease, bone deterioration, collapse of the central nervous system, and death.. According to the Centers for Disease Control and Prevention, the men were told that they were being treated for "bad blood,” a colloquialism that described various conditions such as syphilis, anemia and fatigue. "Bad blood"—specifically the collection of illnesses the term included—was a leading cause of death within the southern African-American community. The men were initially told that the study was only going to last six months, but it was extended to 40 years. After funding for treatment was lost, the study was continued without informing the men that they would never be treated. None of the infected men were treated with penicillin despite the fact that by 1947, the antibiotic had become the standard treatment for syphilis. Study clinicians could have chosen to treat all syphilitic subjects and close the study, or split off a control group for testing with penicillin. Instead, they continued the study without treating any participants; they withheld treatment and information about it from the subjects. In addition, scientists prevented participants from accessing syphilis treatment programs available to other residents in the area. The study continued, under numerous Public Health Service supervisors, until 1972, when a leak to the press resulted in its termination on November 16 of that year. The victims of the study, all African-American, included numerous men who died of syphilis, 40 wives who contracted the disease and 19 children born with congenital syphilis. The 40-year Tuskegee Study of Untreated Syphilis in the African American Male study was a major violation of ethical standards. Researchers knowingly failed to treat participants appropriately after penicillin was proven to be an effective treatment for syphilis and became widely available. Moreover, participants remained ignorant of the study clinicians’ true purpose, which was to observe the natural course of untreated syphilis. The revelation in 1972 of study failures by a whistleblower, Peter Buxtun, led to major changes in U.S. law and regulation concerning the protection of participants in clinical studies. Now studies require informed consent, communication of diagnosis and accurate reporting of test results. The Tuskegee Syphilis Study, cited as "arguably the most infamous biomedical research study in U.S. history," led to the 1979 Belmont Report and to the establishment of the Office for Human Research Protections (OHRP). It also led to federal laws and regulations requiring institutional review boards for the protection of human subjects in studies involving them. The OHRP manages this responsibility within the United States Department of Health and Human Services (HHS). On May 16, 1997, President Bill Clinton formally apologized on behalf of the United States to victims of the study.
  • 5.1K
  • 07 Nov 2022
Topic Review
Kitakyushu (Japan) of Industrial Heritage Tourism
Japan, Asia’s earliest industrialized country, has been transforming into a post-industrialized society. A large number of former industrial heritages in Japan have been well protected. Three industrial heritages have been listed in World Heritage by UNESCO (United Nations Educational, Scientific and Cultural Organization). Moreover, Japan has the largest number of centennial enterprises in the world, reaching 25,321, much more than that of North America and Europe. Compared with other industrialized countries, Japan’s industrial heritages are generally owned by long-lived enterprises, some of these spaces are still in service. Therefore, centennial enterprises often become the most direct stakeholders in the protection of industrial heritages, and play a key role in the transformation into new industrial space for cultural and touristic activities. In other words, under the influence of centennial enterprises, the development of industrial heritage tourism in Japan generally has strong path dependence.
  • 5.1K
  • 13 Dec 2021
Topic Review
IoT-Enabled Smart Cities
Smart cities have been significantly developed and have greatly expanded their potential. In fact, novel advancements to the Internet of things (IoT) have paved the way for new possibilities, representing a set of key enabling technologies for smart cities and allowing the production and automation of innovative services and advanced applications for the different city stakeholders. 
  • 5.1K
  • 21 Feb 2022
Topic Review
Deepfake Detection Datasets
Deepfakes are notorious for their unethical and malicious applications to achieve economic, political, and social reputation goals. Although deepfakes were initially associated with entertainment such as movie visual effects, camera filters, and digital avatars, they are defined as “believable generated media by Deep Neural Network” and have evolved into a mainstream tool for facial forgery. With the development of multiple forgery methods, deepfake data are increasing at a annual rate of ~300%. However, the data published online have different forgery qualities. 
  • 5.1K
  • 28 Feb 2024
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