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
Malignant Superficial Mesenchymal Tumors in Children
Malignant superficial mesenchymal tumors are a very diverse group of neoplasms with few clinical and radiological discriminatory factors. Hence, some of these cancers are rarely suspected based on clinical and radiological grounds, others may be easily misdiagnosed, and the histological analysis of a biopsy or resection is central in the diagnostic process. In children, the age at presentation is a major element of the differential diagnosis. Some tumors have a very distinct epidemiology, while others may be seen at any age. More recently, the advances in molecular biology have greatly improved the diagnosis of mesenchymal tumors and new entities are still being described. 
  • 1.7K
  • 02 Jun 2022
Topic Review
IEEE 802.11ax
IEEE 802.11ax, marketed as Wi-Fi 6 by Wi-Fi Alliance, is a draft Wi-Fi specification standard, and the proposed successor to Wi-Fi 5. The 802.11ax standard is expected to become an official IEEE specification in September 2020. It is designed to operate in licensed exempt bands between 1 and 6 GHz when they become available for 802.11 use. All Wi-Fi 6 devices work over the previously allocated 2.4 and 5 GHz bands. The Wi-Fi 6E designation is for products that also support the standard over 6 GHz. Devices presented at CES 2018 claimed a combined 11 Gbit/s of theoretical data rates. For dense deployments, throughput speeds are 4× higher than IEEE 802.11ac, even though the nominal data rate is just 37% faster at most. Latency is also down 75%. To improve spectrum efficient utilization, the new version introduces better power-control methods to avoid interference with neighboring networks, orthogonal frequency-division multiple access (OFDMA), higher order 1024-QAM, and up-link direction added with the down-link of MIMO and MU-MIMO to further increase throughput, as well as dependability improvements of power consumption and security protocols such as Target Wake Time and WPA3.
  • 1.7K
  • 17 Oct 2022
Topic Review
True Range Multilateration
True range multilateration is a method to determine the location of a movable vehicle or stationary point in space using multiple ranges (distances) between the vehicle/point and multiple spatially-separated known locations (often termed 'stations'). True range multilateration is both a mathematical topic and an applied technique used in several fields. A practical application involving a fixed location is the trilateration method of surveying. Applications involving vehicle location are termed navigation when on-board persons/equipment are informed of its location, and are termed surveillance when off-vehicle entities are informed of the vehicle's location. Two slant-ranges from two known locations can be used to locate a third point in a two-dimensional Cartesian space (plane), which is a frequently applied technique (e.g., in surveying). Similarly, two spherical ranges can be used to locate a point on a sphere, which is a fundamental concept of the ancient discipline of celestial navigation — termed the altitude intercept problem. Moreover, if more than the minimum number of ranges are available, it is good practice to utilize those as well. This article addresses the general issue of position determination using multiple ranges. In two-dimensional geometry, it is known that if a point lies on two circles, then the circle centers and the two radii provide sufficient information to narrow the possible locations down to two – one of which is the desired solution and the other is an ambiguous solution. Additional information often narrow the possibilities down to a unique location. In three-dimensional geometry, when it is known that a point lies on the surfaces of three spheres, then the centers of the three spheres along with their radii also provide sufficient information to narrow the possible locations down to no more than two (unless the centers lie on a straight line). True range multilateration can be contrasted to the more frequently encountered (pseudorange) multilateration, which employs range differences to locate a (typically, movable) point. Pseudo range multilateration is almost always implemented by measuring times-of-arrival (TOAs) of energy waves. True range multilateration can also be contrasted to triangulation, which involves the measurement of angles. Multiple, sometimes overlapping and conflicting terms are employed for similar concepts – e.g., multilateration without modification has been used for aviation systems employing both true ranges and pseudo ranges. Moreover, different fields of endeavor may employ different terms. In geometry, trilateration is defined as the process of determining absolute or relative locations of points by measurement of distances, using the geometry of circles, spheres or triangles. In surveying, trilateration is a specific technique. The term true range multilateration is accurate, general and unambiguous. Authors have also used the terms range-range and rho-rho multilateration for this concept.
  • 1.7K
  • 25 Oct 2022
Topic Review
Abstract Syntax Notation One
Abstract Syntax Notation One (ASN.1) is a standard interface description language for defining data structures that can be serialized and deserialized in a cross-platform way. It is broadly used in telecommunications and computer networking, and especially in cryptography. Protocol developers define data structures in ASN.1 modules, which are generally a section of a broader standards document written in the ASN.1 language. The advantage is that the ASN.1 description of the data encoding is independent of a particular computer or programming language (other than ASN.1.) Because ASN.1 is both human-readable and machine-readable, an ASN.1 compiler can compile modules into libraries of code, CODECs, that decode or encode the data structures. Some ASN.1 compilers can produce code to encode or decode several encodings, e.g. packed, BER or XML. ASN.1 is a joint standard of the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) and ISO/IEC, originally defined in 1984 as part of CCITT X.409:1984. In 1988, ASN.1 moved to its own standard, X.208, due to wide applicability. The substantially revised 1995 version is covered by the X.680 series. The latest revision of the X.680 series of recommendations is the 5.0 Edition, published in 2015.
  • 1.7K
  • 04 Nov 2022
Topic Review
Degree of Ambition and Renewable Energy in Shipping
The early strategy outlines various degrees of desire for the international shipping industry, stressing that technical advancement and the international introduction of alternative fuels and/or renewable energies for international shipping will be crucial to achieving the overall aim. Renewable energy can be implemented in shipping in one of two ways: (1) as retrofits for current fleets or (2) as part of new vessel designs. In terms of new ship concepts, most renewable energy technology will deliver electricity for auxiliary and additional uses, regardless of ship size.
  • 1.7K
  • 14 Nov 2022
Topic Review
Embryogenesis
Embryogenesis is the process by which the embryo forms and develops. In mammals, the term refers chiefly to early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. Embryogenesis starts with the fertilization of the egg cell (ovum) by a sperm cell, (spermatozoon). Once fertilized, the ovum is referred to as a zygote, a single diploid cell. The zygote undergoes mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of a multicellular embryo. Although embryogenesis occurs in both animal and plant development, this article addresses the common features among different animals, with some emphasis on the embryonic development of vertebrates and mammals.
  • 1.7K
  • 10 Nov 2022
Topic Review
Texturing Methods of Abrasive Grinding Wheels
Creating textures on abrasive wheels is a strategy that allows a significant improvement in grinding operations. The reduction of the internal stresses in the workpiece and the temperature during the grinding operation generates an increase in the dimensional accuracy of the workpiece and a longer tool life. Textured abrasive wheels can be produced in many different ways. Depending on the processing method, the dimensional accuracy of the tool and its applicability is changed. 
  • 1.7K
  • 28 Nov 2022
Topic Review
Tjin-A-Djie Family
Template:Infobox given name The Tjin-A-Djie family (pronounced: Chin-Aaa-Jee; popularity: rare/unique) is a prominent gentry family from the country of Suriname with origins from China , France and Vietnam. They are one of the earliest Chinese families arriving in Suriname in the 1800s. The family is known for their significant, national successes ranging from trade to sports, which thrived throughout the latter part of Suriname's history to the present day. Their success in Suriname began in the late Victorian era with the development into the agriculture sector with plantations. From this, the family expanded into other segments of industry and committees. Throughout history, members of the Tjin-A-Djie family have committed to developing various sectors of society involving baked goods and groceries, the Chinese association, import and export development, educational facilities, religious enterprises, politics, sports, and business. Today, the Tjin-A-Djie family continues to be a part of the Suriname Tennis Association, sponsoring the annual Opa Leo Tjin-A-Djie Tennis Tournament. Branches of the family today can be found predominantly in Suriname, with members residing in North America and Europe, such as in the Netherlands. Certain 21st century descendants can claim notoriety in their numerous ethnically diverse make-ups; some as high as twelve different ethnicities including: Chinese, French, Vietnamese, Malaysian, Portuguese, Scottish, Dutch, German, Canadian, Surinamese, Native South American, and African. Their ancestor's full name was Tjin-A-Djie, but according to the habits of the Chinese people, the root and base surname is Tjin. This is what makes this surname so unique to this family.
  • 1.7K
  • 29 Nov 2022
Topic Review
Edible Mushrooms for Major Depressive Disorder
Major depressive disorder (MDD) is still defined as a unitary entity characterized by decontextualized symptoms, which include either: (1) depressed mood or (2) loss of interest or pleasure (anhedonia); and at least five out of nine other symptoms (e.g., fatigue, insomnia, suicidal thoughts, diminished concentration, and psychomotor delay). To qualify as a major depressive episode, the symptoms have to persist for a minimum of 2 weeks and cause significant distress and disturbances in initiating and performing daily activities. Individuals with recurrent episodes are diagnosed with MDD. Edible medicinal mushrooms may be an adjunctive treatment for MDD.
  • 1.7K
  • 10 Jan 2023
Topic Review
Paramaeters that Affect Biomass Gasification
Gasification is a thermochemical process commonly used for bioenergy production, and it is particularly attractive mainly due to its high efficiency. However, its performance is influenced by parameters such as type of feedstock, size of biomass particle, feed rate, type of reactor, temperature, pressure, equivalence ratio, steam to biomass ratio, gasification agent, catalyst, and residence time.
  • 1.7K
  • 12 Apr 2023
Topic Review
Polarization Conversion from Anisotropy Media
Anisotropy of the transmission media exerts a strong influence on the reflection and transmission coefficients. Anomalous refraction yields the consequence of polarization conversion for the refracted wave. We discuss this important physical phenomenon by invoking practical interfaces between strongly anisotropic rocks, e.g., between O-shale and A-shale.  
  • 1.7K
  • 02 Nov 2020
Topic Review
Oximes
Oximes have been studied for decades because of their significant roles as acetylcholinesterase reactivators. Over the last twenty years, a large number of oximes have been reported with useful pharmaceutical properties, including compounds with antibacterial, anticancer, anti-arthritis, and anti-stroke activities. Many oximes are kinase inhibitors and have been shown to inhibit over 40 different kinases, including AMP-activated protein kinase (AMPK), phosphatidylinositol 3-kinase (PI3K), cyclin-dependent kinase (CDK), serine/threonine kinases glycogen synthase kinase 3 α/β (GSK-3α/β), Aurora A, B-Raf, Chk1, death-associated protein-kinase-related 2 (DRAK2), phosphorylase kinase (PhK), serum and glucocorticoid-regulated kinase (SGK), Janus tyrosine kinase (JAK), and multiple receptor and non-receptor tyrosine kinases. Some oximes are inhibitors of lipoxygenase 5, human neutrophil elastase, and proteinase 3. The oxime group contains two H-bond acceptors (nitrogen and oxygen atoms) and one H-bond donor (OH group), versus only one H-bond acceptor present in carbonyl groups. This feature, together with the high polarity of oxime groups, may lead to a significantly different mode of interaction with receptor binding sites compared to corresponding carbonyl compounds, despite small changes in the total size and shape of the compound. In addition, oximes can generate nitric oxide.
  • 1.7K
  • 03 Jun 2021
Topic Review
Biobutanol Blends in Diesel Engines
Fossil fuels have often been partially replaced by renewable fuels to reduce both the environmental impact and the dependence on conventional fuels in internal combustion engines. When butanol is blended with diesel fuels, PM emissions sharply decrease, THC emissions increase and there is no consensus regarding CO and NOx emissions. No startability problems up to 40% butanol content are concluded for tests at warm ambient temperature
  • 1.7K
  • 23 Jun 2021
Topic Review
Building information modeling (BIM)
BIM is defined as the“digital representation of physical and functional characteristics of a facility”. It is the process of producing and maintaining project related information throughout the different phases of the building life cycle. The information not only constitutes geometric properties of the building elements, but also extends to include any customized information related to the building. There are various uses for BIMs, which include 3D visualization, 4D scheduling, quantity take-off, etc. Although the use of BIM functionalities is an active field of research, exploiting the advantages of BIM in the deconstruction stage remains limited. 
  • 1.7K
  • 09 Oct 2021
Topic Review
Reactive Oxygen Species in Malaria Treatment
Malaria is a vector-transmitted parasite disease that continues to plague mankind. It is caused in humans by five main species of Plasmodium. The majority of conventional antimalarials kill parasites via direct or indirect overproduction of reactive oxygen species (ROS). Even when some parasites try to manage these ROS, over production of the ROS still leads to parasite death. This therefore underscores the role of ROS in the antiplasmodial activity of different antimalarials.
  • 1.7K
  • 04 Mar 2022
Topic Review
AIE-Active Photosensitizers
Photodynamic therapy (PDT) is a non-invasive approach for tumor elimination that is attracting more and more attention due to the advantages of minimal side effects and high precision. In typical PDT, reactive oxygen species (ROS) generated from photosensitizers play the pivotal role, determining the efficiency of PDT. However, applications of traditional PDT were usually limited by the aggregation-caused quenching (ACQ) effect of the photosensitizers employed. Fortunately, photosensitizers with aggregation-induced emission (AIE-active photosensitizers) have been developed with biocompatibility, effective ROS generation, and superior absorption, bringing about great interest for applications in oncotherapy.
  • 1.7K
  • 27 May 2022
Topic Review
Digital Droplet PCR in Hematologic Malignancies
Digital Droplet Polymerase Chain Reaction (ddPCR) is a specific, accurate and time-saving technique capables of accurately quantifying gene expression or detecting point mutations applicable in several hematologic disorders, such as leukemias, lymphomas, myeloma, and chronic myeloproliferative neoplasms, and in transplant field. The ddPCR might provide useful informations in prognostic and therapeutic setting.
  • 1.7K
  • 24 Jun 2022
Topic Review
Extractive Industries Transparency Initiative
The Extractive Industries Transparency Initiative (EITI) is a global standard for the good governance of oil, gas and mineral resources. It seeks to address the key governance issues in the extractive sectors. The EITI Standard requires information along the extractive industry value chain from the point of extraction, to how the revenue makes its way through the government and its contribution to the economy. This includes how licenses and contracts are allocated and registered, who the beneficial owners of those operations are, what the fiscal and legal arrangements are, how much is produced, how much is paid, where the revenue is allocated, and its contributions to the economy, including employment. The EITI Standard is implemented in 52 countries around the world. Each of these countries is required to publish an annual EITI Report to disclosing information on: contracts and licenses, production, revenue collection, revenue allocation, and social and economic spending. Every country goes through a quality-assurance mechanism, called Validation, at least every three years. Validation serves to assess performance towards meeting the EITI Standard and promote dialogue and learning at the country level. It also safeguards the integrity of the EITI by holding all EITI implementing countries to the same global standard. Each implementing country has its own national secretariat and multi-stakeholder group made up of representatives from the country’s government, extractive companies and civil society. The multi-stakeholder group takes decisions on how the EITI process is carried out in the country. The EITI Standard is developed and overseen by an international multi-stakeholder Board, consisting of representatives from governments, extractives companies, civil society organisations, financial institutions and international organisations. The current Chair of the EITI is Fredrik Reinfeldt, former Prime Minister of Sweden. The previous chairs have been Clare Short (2011-2016), former UK Secretary of State for International Development and Peter Eigen (2009-2011). The EITI International Secretariat is located in Oslo, Norway and is headed by Eddie Rich.
  • 1.7K
  • 31 Oct 2022
Topic Review
Minority Influence
Minority influence, a form of social influence, takes place when a member of a minority group influences the majority to accept the minority's beliefs or behavior. This occurs when a small group or an individual acts as an agent of social change by questioning established societal perceptions, and proposing alternative, original ideas which oppose the existing social norms. There are two types of social influence: majority influence (resulting in conformity and public compliance) and minority influence (resulting in conversion). Majority influence refers to the majority trying to produce conformity on the minority, while minority influence is converting the majority to adopt the thinking of the minority group. Unlike other forms of influence, minority influence is often thought of as a more innovative form of social change, because it usually involves a personal shift in private opinion. Examples of minority influence include the Civil Rights Movement in America and the anti-apartheid movement in South Africa .
  • 1.7K
  • 23 Nov 2022
Topic Review
Tau Protein and Tauopathies
Tau, a member of the microtubule-associated proteins, is a known component of the neuronal cytoskeleton; however, in the brain tissue, it is involved in other vital functions beyond maintaining the cellular architecture. The pathologic tau forms aggregates inside the neurons and ultimately forms the neurofibrillary tangles. Intracellular and extracellular accumulation of different tau isoforms, including dimers, oligomers, paired helical filaments and tangles, lead to a highly heterogenous group of diseases named “Tauopathies”.
  • 1.7K
  • 06 May 2023
  • Page
  • of
  • 2728
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