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
Active and Assisted Living
Over the last decade, there has been considerable and increasing interest in the development of Active and Assisted Living (AAL) systems to support independent living. The demographic change towards an aging population has introduced new challenges to today’s society from both an economic and societal standpoint. AAL can provide an array of solutions for improving the quality of life of individuals, for allowing people to live healthier and independently for longer, for helping people with disabilities, and for supporting caregivers and medical staff. 
  • 2.9K
  • 19 Nov 2021
Topic Review
SmartISM
Interpretive Structural Modeling (ISM) is a technique to establish the interrelationships between elements of interest in a specific domain through experts’ knowledge of the context of the elements. Every discipline is expanding its frontier and multiple disciplinary approaches have become essential to solve complex problems. This leads to the study of a large number of constructs of interests simultaneously. These constructs may have been identified in theory or practice. Warfield in the 1970’s developed a technique to establish an interrelationship model between variables known as interpretive structural modeling (ISM). The holistic picture of important constructs in the structured form derived from ISM technique helps the practitioners to solve the problem effectively. This technique is widely used due to its simplistic procedure and profound value addition in problem solving in different domains.
  • 2.9K
  • 23 Aug 2021
Topic Review
FileMaker Pro
FileMaker Pro is a cross-platform relational database application from Claris International, a subsidiary of Apple Inc. It integrates a database engine with a graphical user interface (GUI) and security features, allowing users to modify the database by dragging new elements into layouts, screens, or forms. FileMaker evolved from a DOS application, but was then developed primarily for the Apple Macintosh and released in April 1985. It was succeeded by FileMaker Pro in 1990. Since 1992 it has been available for Microsoft Windows and for the classic Mac OS and macOS, and can be used in a cross-platform environment. FileMaker server briefly ran on Linux, but Linux support was abandoned with FileMaker 7, thereafter only running on Windows or macOS servers. A client version was released for iOS devices in July 2010. It is available in desktop, server, iOS and web-delivery configurations. In 2016, FileMaker Cloud was introduced, including a Linux server (CentOS), which was offered exclusively through the Amazon Marketplace. In November 2019, FileMaker Cloud was reintroduced as a software as a service product offered directly from Claris for FileMaker Pro 18.0.3 using FileMaker Server Cloud 2.18 service on Amazon Servers, but managed by Claris instead of through the Amazon Market Place, and making use of the new FileMaker ID authentication.
  • 2.9K
  • 28 Oct 2022
Topic Review
Encoding (Memory)
Memory has the ability to encode, store and recall information. Memories give an organism the capability to learn and adapt from previous experiences as well as build relationships. Encoding allows a perceived item of use or interest to be converted into a construct that can be stored within the brain and recalled later from long-term memory. Working memory stores information for immediate use or manipulation which is aided through hooking onto previously archived items already present in the long-term memory of an individual.
  • 2.9K
  • 17 Nov 2022
Topic Review
Q'uq'umatz
Q'uq'umatz (Mayan: [qʔuː qʔuːˈmats]) (alternatively Qucumatz, Gukumatz, Gucumatz, Gugumatz, Kucumatz etc.) was a deity of the Postclassic K'iche' Maya. Q'uq'umatz was the Feathered Serpent divinity of the Popol Vuh who created humanity together with the god Tepeu. Q'uq'umatz is considered to be the rough equivalent of the Aztec god Quetzalcoatl, and also of Kukulkan of the Yucatec Maya tradition. It is likely that the feathered serpent deity was borrowed from one of these two peoples and blended with other deities to provide the god Q'uq'umatz that the K'iche' worshipped. Q'uq'umatz may have had his origin in the Valley of Mexico; some scholars have equated the deity with the Aztec deity Ehecatl-Quetzalcoatl, who was also a creator god. Q'uq'umatz may originally have been the same god as Tohil, the K'iche' sun god who also had attributes of the feathered serpent, but they later diverged and each deity came to have a separate priesthood. Q'uq'umatz was one of the gods who created the world in the Popul Vuh, the K'iche' creation epic. Q'uq'umatz, god of wind and rain, was closely associated with Tepeu, god of lightning and fire. Both of these deities were considered to be the mythical ancestors of the K'iche' nobility by direct male line. Q'uq'umatz carried the sun across the sky and down into the underworld and acted as a mediator between the various powers in the Maya cosmos. The deity was particularly associated with water, clouds, the wind and the sky. Kotuja', the K'iche' king who founded the city of Q'umarkaj, bore the name of the deity as a title and was likely to have been a former priest of the god. The priests of Q'uq'umatz at Q'umarkaj, the K'iche' capital, were drawn from the dominant Kaweq dynasty and acted as stewards in the city.
  • 2.9K
  • 21 Nov 2022
Topic Review
Aetiology and Pathophysiology of Parkinson’s and Alzheimer’s Disease
Neurodegeneration is hallmarked by the progressive loss of dopaminergic neurons and/or a significant increase in protein aggregates in the brain. Neurodegenerative diseases are a leading cause of death worldwide with over 15 million people currently suffering from either Parkinson’s disease (PD) or Alzheimer’s disease (AD). PD is often characterized by both motor and non-motor symptoms, including muscle rigidity, tremors and bradykinesia, with AD displaying symptoms of confusion and dementia.
  • 2.9K
  • 22 Mar 2023
Topic Review
Earth Pigments in Wall Paintings
Iron-containing earth minerals of various hues were the earliest pigments of the prehistoric artists who dwelled in caves. Being a prominent part of human expression through art, nature-derived pigments have been used in continuum through ages until now. Studies reveal that the primitive artist stored or used his pigments as color cakes made out of skin or reeds. Although records to help understand the technical details of Indian painting in the early periodare scanty, there is a certain amount of material from which some idea may be gained regarding the methods used by the artists to obtain their results. Considering Indian wall paintings, the most widely used earth pigments include red, yellow, and green ochres, making it fairly easy for the modern era scientific conservators and researchers to study them.
  • 2.9K
  • 17 Sep 2021
Topic Review
Propellant Depot
An orbital propellant depot is a cache of propellant that is placed in orbit around Earth or another body to allow spacecraft or the transfer stage of the spacecraft to be fueled in space. It is one of the types of space resource depots that have been proposed for enabling infrastructure-based space exploration. Many different depot concepts exist depending on the type of fuel to be supplied, location, or type of depot which may also include a propellant tanker that delivers a single load to a spacecraft at a specified orbital location and then departs. In-space fuel depots are not necessarily located near or at a space station. Potential users of in-orbit refueling and storage facilities include space agencies, defense ministries and communications satellite or other commercial companies. Satellite servicing depots would extend the lifetime of satellites that have nearly consumed all of their orbital maneuvering fuel and are likely placed in a geosynchronous orbit. The spacecraft would conduct a space rendezvous with the depot, or vice versa, and then transfer propellant to be used for subsequent orbital maneuvers. In 2011, Intelsat showed interest in an initial demonstration mission to refuel several satellites in geosynchronous orbit, but all plans have been since scrapped. A low earth orbit (LEO) depot's primary function would be to provide propellant to a transfer stage headed to the moon, Mars, or possibly a geosynchronous orbit. Since all or a fraction of the transfer stage propellant can be off-loaded, the separately launched spacecraft with payload and/or crew could have a larger mass or use a smaller launch vehicle. With a LEO depot or tanker fill, the size of the launch vehicle can be reduced and the flight rate increased—or, with a newer mission architecture where the beyond-Earth-orbit spacecraft also serves as the second stage, can facilitate much larger payloads—which may reduce the total launch costs since the fixed costs are spread over more flights and fixed costs are usually lower with smaller launch vehicles. A depot could also be placed at Earth-Moon Lagrange point 1 (EML-1) or behind the Moon at EML-2 to reduce costs to travel to the moon or Mars. Placing a depot in Mars orbit has also been suggested.
  • 2.9K
  • 22 Nov 2022
Topic Review
Blockchain Technology and Tokenization
Blockchain is an open-source technology that excludes the traditional third parties by relying on collective verification, thus offering a great alternative in terms of costs, traceability, security, and speed. When two financial entities such as banks receive a request to transfer money from one account to another, they have to update the balances of their respective customers. This costly and time-consuming coordination and synchronization exercise can be simplified on a blockchain by using a single ledger of transactions reflecting a single version of records instead of two different databases. Blockchain technology offers a myriad of value through a frictionless process of immutable and transparent records and through converting assets into digital tokens (i.e., tokenization) with smart contracts. 
  • 2.9K
  • 01 Jun 2021
Topic Review
Fiber-Reinforced Geopolymer Composite
Fiber-reinforced geopolymer composite (FRGC) is emerging as one of the alternative materials for cement in the construction industry. FRGC is considered an eco-friendly material due to its role in the global reduction in emission of CO2 to the environment. Simultaneously, the composite provides good mechanical strength of flexural modulus, loss modulus, post-impact strength, and durability for a definite period at room and elevated temperatures. A positive aspect of the geopolymer matrix used for this composite is that could provide a finite period of durability at elevated temperatures without releasing toxic gases to the surroundings. Fibers enhanced the brittle behavior of the geopolymer matrix into ductile one with improved mechanical strength and residual impact strength.
  • 2.9K
  • 09 Jul 2021
Topic Review
Biomaterials for Ophthalmic Applications
Ophthalmology is the branch of medicine that deals with diseases of the eye, the organ responsible for vision, and its attachments. Biomaterials can be made with different types of materials and can replace or improve a function or an organ, specifically the eye in the case of ophthalmic biomaterials. Biomaterials are substances that interact with biological systems for a medical purpose, either as a therapeutic (treat, augment, repair, or replace a tissue function of the body) or a diagnostic agent, and have continued to improve over the years, leading to the creation of new biomaterials.
  • 2.9K
  • 22 Jun 2022
Topic Review
Chelicerata
The subphylum Chelicerata (from New Latin, from fr chélicère, from grc χηλή (Script error: No such module "Ancient Greek".) 'claw, chela', and κέρας (Script error: No such module "Ancient Greek".) 'horn') constitutes one of the major subdivisions of the phylum Arthropoda. It contains the sea spiders, horseshoe crabs, and arachnids (including harvestmen, scorpions, spiders, solifuges, ticks, and mites, among many others), as well as a number of extinct lineages, such as the eurypterids (sea scorpions) and chasmataspidids. The Chelicerata originated as marine animals in the Middle Cambrian period; the first confirmed chelicerate fossils, belonging to Sanctacaris, date from 508 million years ago. The surviving marine species include the four species of xiphosurans (horseshoe crabs), and possibly the 1,300 species of pycnogonids (sea spiders), if the latter are indeed chelicerates. On the other hand, there are over 77,000 well-identified species of air-breathing chelicerates, and there may be about 500,000 unidentified species. Like all arthropods, chelicerates have segmented bodies with jointed limbs, all covered in a cuticle made of chitin and proteins. The chelicerate body plan consists of two tagmata, the prosoma and the opisthosoma, except that mites have lost a visible division between these sections. The chelicerae, which give the group its name, are the only appendages that appear before the mouth. In most sub-groups, they are modest pincers used to feed. However, spiders' chelicerae form fangs that most species use to inject venom into prey. The group has the open circulatory system typical of arthropods, in which a tube-like heart pumps blood through the hemocoel, which is the major body cavity. Marine chelicerates have gills, while the air-breathing forms generally have both book lungs and tracheae. In general, the ganglia of living chelicerates' central nervous systems fuse into large masses in the cephalothorax, but there are wide variations and this fusion is very limited in the Mesothelae, which are regarded as the oldest and most basal group of spiders. Most chelicerates rely on modified bristles for touch and for information about vibrations, air currents, and chemical changes in their environment. The most active hunting spiders also have very acute eyesight. Chelicerates were originally predators, but the group has diversified to use all the major feeding strategies: predation, parasitism, herbivory, scavenging and eating decaying organic matter. Although harvestmen can digest solid food, the guts of most modern chelicerates are too narrow for this, and they generally liquidize their food by grinding it with their chelicerae and pedipalps and flooding it with digestive enzymes. To conserve water, air-breathing chelicerates excrete waste as solids that are removed from their blood by Malpighian tubules, structures that also evolved independently in insects. While the marine horseshoe crabs rely on external fertilization, air-breathing chelicerates use internal but usually indirect fertilization. Many species use elaborate courtship rituals to attract mates. Most lay eggs that hatch as what look like miniature adults, but all scorpions and a few species of mites keep the eggs inside their bodies until the young emerge. In most chelicerate species the young have to fend for themselves, but in scorpions and some species of spider the females protect and feed their young. The evolutionary origins of chelicerates from the early arthropods have been debated for decades. Although there is considerable agreement about the relationships between most chelicerate sub-groups, the inclusion of the Pycnogonida in this taxon has recently been questioned (see below), and the exact position of scorpions is still controversial, though they were long considered the most basal of the arachnids. Venom has evolved three times in the chelicerates; spiders, scorpions and pseudoscorpions, or four times if the hematophagous secretions produced by ticks are included. In addition there have been undocumented descriptions of venom glands in Solifugae. Chemical defense has been found in whip scorpions, shorttailed whipscorpions, harvestmen, beetle mites and sea spiders. Although the venom of a few spider and scorpion species can be very dangerous to humans, medical researchers are investigating the use of these venoms for the treatment of disorders ranging from cancer to erectile dysfunction. The medical industry also uses the blood of horseshoe crabs as a test for the presence of contaminant bacteria. Mites can cause allergies in humans, transmit several diseases to humans and their livestock, and are serious agricultural pests.
  • 2.9K
  • 18 Oct 2022
Topic Review
New Chronology (Rohl)
New Chronology is an alternative chronology of the ancient Near East developed by English Egyptologist David Rohl and other researchers beginning with A Test of Time: The Bible - from Myth to History in 1995. It contradicts mainstream Egyptology by proposing a major revision of the established Egyptian chronology, in particular by re-dating Egyptian kings of the Nineteenth through Twenty-fifth Dynasties, bringing forward conventional dating by up to 350 years. Rohl asserts that the New Chronology allows him to identify some of the characters in the Hebrew Bible with people whose names appear in archaeological finds. The New Chronology, one of several proposed radical revisions of the conventional chronology, has not been accepted in academic Egyptology, where the conventional chronology or small variations of it remain standard. Amélie Kuhrt, head of Ancient Near Eastern History at University College London, in one of the standard reference works of the discipline, notes: "Many scholars feel sympathetic to the critique of weaknesses in the existing chronological framework [...], but most archaeologists and ancient historians are not at present convinced that the radical redatings proposed stand up to close examination." Rohl's most vocal critic has been Kenneth Kitchen, one of the leading experts on biblical history and the author of the standard work on the conventional chronology of the Third Intermediate Period of Egypt, the period most directly affected by the New Chronology's redating of the Nineteenth to Twenty-fifth Dynasties.
  • 2.9K
  • 20 Oct 2022
Topic Review
FTIR for Vehicle Exhaust Emissions
In a Fourier Transform InfraRed (FTIR) spectrometer, some of the infrared (IR) radiation is absorbed by the sample, and some of it is passed through (transmitted). The resulting molecular absorption and transmission response can be used to identify the components of the sample and their concentration.
  • 2.9K
  • 20 Aug 2021
Topic Review
Acrylate Polymers in Dentistry
Concerning the composition and method of polymerization initiation, polymers for the production of denture bases are divided into four types: heat-, cold-, light-, and microwave-polymerized. Computer-Aided Design and Manufacturing (CAD/CAM) acrylate dentures are made from factory blocks of dental acrylates and show optimal mechanical and physical properties, undoubtedly better monomer polymerization and thus biocompatibility, and stability of the shape and colour of the base and dentures. Regardless of the number of advantages that these polymers have to offer, they also exhibit certain disadvantages. Technological development enables the enhancement of all acrylate properties to respond better to the demands of the profession. Special attention should be paid to improving the biological characteristics of acrylate polymers, due to reported adverse reactions of patients and dental staff to potentially toxic substances released during their preparation and use. 
  • 2.9K
  • 03 Nov 2022
Topic Review
Biodegradable Polymers and Stages of Biodegradation
Sustainable and biodegradable bioplastics are gaining significant attention due to resource depletion and plastic pollution. An increasing number of environmentally friendly plastics are being introduced to the market with the aim of addressing these concerns. However, many final products still contain additives or mix non-biodegradable polymers to ensure minimum performance, which often undermines their ecological footprint. Moreover, there is a lack of knowledge about all stages of biodegradation and their accuracy in classifying products as biodegradable.
  • 2.9K
  • 25 Jun 2023
Topic Review
Pectolinarin and Pectolinarigenin
Flavonoids are metabolites widely distributed in plants and commonly present in foods, such as fruits and vegetables. Pectolinarin, which belongs to the flavone subclass, has attracted considerable attention due to its presence in many medicinal plants. It has turned out to be a good biological agent especially due to its antioxidant, anti-inflammatory, antidiabetic, and antitumor activities, evaluated both in vitro and in vivo. Its aglycone, the metabolite pectolinarigenin, is also known for a series of biological properties including anti-inflammatory and antidiabetic effects. In the first overview on the two metabolites here presented, their collection, isolation and the results of their biological evaluation are reported
  • 2.9K
  • 28 Dec 2020
Topic Review Peer Reviewed
Merging Smart and Healthy Cities to Support Community Wellbeing and Social Connection
Urban planning has long pursued the improvement of health and wellbeing through the rapidly evolving scholarship and practice of health-supportive environments, underpinned by the seminal World Health Organization’s Healthy Cities Framework. Although a much more recent development, technology has been informing urban planning, as well as advancing healthcare and personal wellbeing monitoring and assessment. Known as the Smart City movement, it has much to offer regarding life in towns and cities, as well as how they are managed, maintained, and developed. There is also a growing appreciation of the potential for smart city technology to enhance human and environmental health in the context of urban planning and public place making. This has been reinforced by the COVID-19 pandemic with its reawakening of community interest in health and wellbeing, including mental illness, a greater awareness of the importance of local environments, and an explosion of technological knowhow in the embrace of remote working, online shopping, and education. Using the example of the authors’ “Smart Social Spaces” project, this entry discusses the potential benefits of an evolving integrative concept called “Smart Healthy Social Spaces”. The aim is to support community wellbeing as part of everyday living, especially associated with social connection, in densely populated and culturally diverse urban environments, where locally situated public spaces are increasingly important for all citizens.
  • 2.9K
  • 04 Sep 2023
Topic Review
Production of Mono-, Few-, and Multi-Layer Graphene
Mono-, few-, and multi-layer graphene can be synthesized using various methods, including micromechanical exfoliation, chemical vapour deposition, and chemical methods such as oxidizing graphene into graphene oxide and then reducing it chemically or thermally.
  • 2.9K
  • 26 Oct 2022
Topic Review
Extended-Spectrum β-Lactamases
The rise of antimicrobial resistance, particularly from extended-spectrum β-lactamase producing Enterobacteriaceae (ESBL-E), poses a significant global health challenge as it frequently causes the failure of empirical antibiotic therapy, leading to morbidity and mortality. The E. coli- and K. pneumoniae-derived CTX-M genotype is one of the major types of ESBL. Mobile genetic elements (MGEs) are involved in spreading ESBL genes among the bacterial population. Due to the rapidly evolving nature of ESBL-E, there is a lack of specific standard examination methods. Carbapenem has been considered the drug of first choice against ESBL-E. 
  • 2.9K
  • 07 Dec 2023
  • Page
  • of
  • 2799
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