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
Obsessive-Compulsive Disorder and Social Media
Obsessive-compulsive disorder (OCD) is a mental disorder where people experience intrusive thoughts and must practice rituals to relieve their discomfort. More specifically, it would be better to refer to them as obsessive-compulsive spectrum disorders characterized by continuous mental or behavioral activity that fills most of the people’s time, with the aim of neutralizing invasive mental content. All these activities are always “ego-dystonic”, that is, they are repugnant or inconsistent with the person’s values.
  • 2.5K
  • 29 Aug 2022
Topic Review
Gravity Recovery and Climate Experiment
File:15 Years of Freshwater Trends Seen by GRACE.webm The Gravity Recovery and Climate Experiment (GRACE) was a joint mission of NASA and the German Aerospace Center. Twin satellites took detailed measurements of Earth's gravity field anomalies from its launch in March 2002 to the end of its science mission in October 2017. By measuring gravity anomalies, GRACE showed how mass is distributed around the planet and how it varies over time. Data from the GRACE satellites is an important tool for studying Earth's ocean, geology, and climate. GRACE was a collaborative endeavor involving the Center for Space Research at the University of Texas at Austin, NASA's Jet Propulsion Laboratory, the German Aerospace Center and Germany's National Research Center for Geosciences, Potsdam. The Jet Propulsion Laboratory was responsible for the overall mission management under the NASA ESSP (Earth System Science Pathfinder) program. The principal investigator is Byron Tapley of the University of Texas Center for Space Research, and the co-principal investigator is Christoph Reigber of the GeoForschungsZentrum (GFZ) Potsdam. The two GRACE satellites (GRACE-1 and GRACE-2) were launched from Plesetsk Cosmodrome, Russia, on a Rockot (SS-19 + Breeze upper stage) launch vehicle on 17 March 2002. The spacecraft were launched to an initial altitude of approximately 500 km at a near-polar inclination of 89°. During normal operations, the satellites were separated by 220 km along their orbit track. This system was able to gather global coverage every 30 days. GRACE far exceeded its 5-year design lifespan, operating for 15 years until the decommissioning of GRACE-2 on 27 October 2017. Its successor, GRACE-FO, was successfully launched on 22 May 2018.
  • 2.5K
  • 06 Oct 2022
Topic Review
CELTA
CELTA (Certificate in English Language Teaching to Adults) is an initial teacher training qualification for teaching English as a second or foreign language (ESL and EFL). It is provided by Cambridge Assessment English through authorised Cambridge English Teaching Qualification centres and can be taken either full-time or part-time. CELTA was developed to be suitable both for those interested in Teaching English as a Foreign Language (TEFL) and for Teaching English to the Speakers of Other Languages (TESOL). CELTA is designed for candidates with little or no previous English language teaching (ELT) experience. It is also taken by candidates with some teaching experience who have received little practical teacher training or who wish to gain internationally recognised qualification. Candidates should have English language skills equivalent to at least C1 of the Common European Framework of Reference for Languages (CEFR) or an IELTS score of 7. CELTA gives equal emphasis to theory and practice. The strong practical element demonstrates to employers that successful candidates have the skills to succeed in the classroom. Courses can be taken full-time or part-time and either fully face-to-face or in a blended format that combines on-line self-study with practical teaching experience. A full-time, face-to-face course typically lasts between four and five weeks. CELTA is a continuous assessment course (i.e. participants are assessed throughout the course) leading to a certificate qualification. Candidates who successfully complete the course can start working in a variety of English language teaching contexts around the world. CELTA is regulated at Level 5 of the Qualifications and Credit Framework for England, Wales and N. Ireland and is suitable for teachers at Foundation and Developing level on the Cambridge English Teaching Framework.
  • 2.5K
  • 03 Nov 2022
Topic Review
Short Interspersed Nuclear Elements (SINEs)
SINEs or Short Interspersed Nuclear Elements are sequences of non-coding DNA present at high frequencies in various eukaryotic genomes. They are a class of retrotransposons, DNA elements that amplify themselves throughout eukaryotic genomes, often through RNA intermediates. Short-interspersed nuclear elements are characterized by their size and method of retrotransposition. The literature differs on the length of the SINEs but there is a general consensus that they often range in length from about 100 to 700 base pairs (more or less, arbitrary cut-offs). Short-interspersed nuclear elements are transcribed by RNA polymerase III which is known to transcribe ribosomal RNA and tRNA, two types of RNA vital to ribosomal assembly and mRNA translation. SINEs, like tRNAs and many small-nuclear RNAs possess an internal promoter and thus are transcribed differently than most protein-coding genes. In other words, short-interspersed nuclear elements have their key promoter elements within the transcribed region itself. Though transcribed by RNA polymerase III, SINEs and other genes possessing internal promoters, recruit different transcriptional machinery and factors than genes possessing upstream promoters. The RNA coded by the short-interspersed nuclear element does not code for any protein product but is nonetheless reverse-transcribed and inserted back into an alternate region in the genome. For this reason, short interspersed nuclear elements are believed to have co-evolved with long interspersed nuclear element (LINEs), as LINEs do in fact encode protein products which enable them to be reverse- transcribed and integrated back into the genome. SINEs are believed to have co-opted the proteins coded by LINEs which are contained in 2 reading frames. Open reading frame 1 (ORF 1) encodes a protein which binds to RNA and acts as a chaperone to facilitate and maintain the LINE protein-RNA complex structure. Open reading frame 2 (ORF 2) codes a protein which possesses both endonuclease and reverse transcriptase activities. This enables the LINE mRNA to be reverse-transcribed into DNA and integrated into the genome based on the sequence-motifs recognized by the protein’s endonuclease domain. Furthermore, SINEs are known to share sequence homology with LINES which gives a basis by which the LINE machinery can reverse transcribe and integrate SINE transcripts. Alternately, some SINEs are believed to use a much more complex system of integrating back into the genome; this system involves the use random double-stranded DNA breaks (rather than the endonuclease coded by related long-interspersed nuclear elements creating an insertion-site). These DNA breaks are utilized to prime reverse transcriptase, ultimately integrating the SINE transcript back into the genome. SINEs nonetheless depend on enzymes coded by other DNA elements and are thus known as non-autonomous retrotransposons as they depend on the machinery of LINEs, which are known as autonomous retrotransposons.
  • 2.5K
  • 22 Nov 2022
Topic Review
TLR4
Toll-like receptor 4 is a protein that in humans is encoded by the TLR4 gene. TLR4 is a transmembrane protein, member of the toll-like receptor family, which belongs to the pattern recognition receptor (PRR) family. Its activation leads to an intracellular signaling pathway NF-κB and inflammatory cytokine production which is responsible for activating the innate immune system. TRL4 expressing cells are myeloid (erythrocytes, granulocytes, macrophages) rather than lymphoid (T-cells, B-cells, NK cells). Most myeloid cells also express high levels of CD14, which facilitates activation of TLR4 by LPS. It is most well known for recognizing lipopolysaccharide (LPS), a component present in many Gram-negative bacteria (e.g. Neisseria spp.) and selected Gram-positive bacteria. Its ligands also include several viral proteins, polysaccharide, and a variety of endogenous proteins such as low-density lipoprotein, beta-defensins, and heat shock protein. Palmitic acid is also a TLR4 agonist. TLR4 has also been designated as CD284 (cluster of differentiation 284). The molecular weight of TLR4 is approximately 95 kDa.
  • 2.5K
  • 29 Nov 2022
Topic Review
Application of Smart Techniques for Sustainable Crop Production
Smart farming, often known as smart agriculture, is a farming practice that uses sustainable methods to meet the population’s growing food needs while minimizing negative effects. The global community has embraced it and is supporting it. The fundamental tenet of this strategy is to effectively utilize the resources at hand for sustainable output while lowering the expenses of all activities associated with the agricultural industry. Smart agriculture represents the use of technologies such as sensors; the internet of things (IoT), which is a network of computing devices; artificial intelligence; and robotics to assist traditional agriculture and convert it into a smart and sustainable agriculture. 
  • 2.5K
  • 27 Feb 2023
Topic Review
360-Panoramas for Historic Buildings
360-degree panorama tours such as Google Street View enable the virtual exploration of heritage sites and historic buildings. They demonstrate limited interaction and immersion across a range of platforms and devices, without the requirement of expensive virtual reality headsets, but typically do not integrate other media to leverage spatially richer ways to communicate the historical developments of architectural interiors and exteriors.
  • 2.5K
  • 24 Jul 2023
Topic Review
Video Game Engagement and Social Development in Children
Video games have rapidly emerged as a prevalent facet of children’s daily experiences globally. Their appeal to children can be attributed to features such as engaging content, immediate feedback, user interactivity, broad media accessibility, and applicability across a diverse age spectrum.
  • 2.5K
  • 20 Oct 2023
Topic Review
Environmental Niche Modelling
Environmental niche modelling, alternatively known as species distribution modelling, (ecological) niche modelling, predictive habitat distribution modelling, and climate envelope modelling refers to the process of using computer algorithms to predict the distribution of species in geographic space on the basis of a mathematical representation of their known distribution in environmental space (= realized ecological niche). The environment is in most cases represented by climate data (such as temperature, and precipitation), but other variables such as soil type, water depth, and land cover can also be used. These models allow for interpolating between a limited number of species occurrence and they are used in several research areas in conservation biology, ecology and evolution. The extent to which such modelled data reflect real-world species distributions will depend on a number of factors, including the nature, complexity, and accuracy of the models used and the quality of the available environmental data layers; the availability of sufficient and reliable species distribution data as model input; and the influence of various factors such as barriers to dispersal, geologic history, or biotic interactions, that increase the difference between the realized niche and the fundamental niche. Environmental niche modelling may be considered a part of the discipline of biodiversity informatics.
  • 2.5K
  • 31 Oct 2022
Topic Review
Aldosterone
Aldosterone is a steroid hormone that is produced in the adrenal cortex. Its major renal effect is to regulate electrolyte and water homeostasis in the distal tubule, thus maintaining blood pressure and extracellular fluid homeostasis through the activation of mineralocorticoid receptors (MR) in epithelial cells [2]. Aldosterone enters an epithelial cell and binds to the MR. The complex of aldosterone and MR translocates into the nucleus and regulates gene transcription of, among others, the epithelial sodium channel (ENaC) and the signaling proteins and kinases that impact channel and transporter activity, such as serum/glucocorticoid kinases (SGKs).
  • 2.5K
  • 30 Oct 2020
Topic Review
Hospital Foodservice to Improve Inpatients' Food Intakes
Reduced food intake among hospitalized patients or inpatients is often associated with adverse health consequences such as malnutrition. To improve patients’ food intake, satisfaction, nutritional status, and quality of life, five intervention strategies were identified: implementing a new food service system, menu modification, multidisciplinary approaches in nutrition care, protected mealtime intervention programs, and attractive meal presentation.
  • 2.5K
  • 22 Nov 2021
Topic Review
Gamma-Linolenic Acid and Attention Deficit Hyperactivity Disorder
The use of polyunsaturated fatty acids in Attention-Deficit/Hyperactivity Disorder (ADHD) and developmental disorders has been gaining interest with preparations containing different dosages and combinations. Gamma-linolenic acid is an ω-6 fatty acid of emerging interest with potential roles as an adjuvant anti-inflammatory agent that could be used with ω-3 Polyunsaturated fatty acids (PUFAs) in the treatment of ADHD and associated symptoms.
  • 2.5K
  • 26 Aug 2022
Topic Review
MRNA Vaccine
An mRNA vaccine is a type of vaccine that uses a copy of a molecule called messenger RNA (mRNA) to produce an immune response. The vaccine delivers molecules of antigen-encoding mRNA into immune cells, which use the designed mRNA as a blueprint to build foreign protein that would normally be produced by a pathogen (such as a virus) or by a cancer cell. These protein molecules stimulate an adaptive immune response that teaches the body to identify and destroy the corresponding pathogen or cancer cells. The mRNA is delivered by a co-formulation of the RNA encapsulated in lipid nanoparticles that protect the RNA strands and help their absorption into the cells. File:MRNA vaccines against the coronavirus.webm Reactogenicity, the tendency of a vaccine to produce adverse reactions, is similar to that of conventional non-RNA vaccines. People susceptible to an autoimmune response may have an adverse reaction to messenger RNA vaccines. The advantages of mRNA vaccines over traditional vaccines are ease of design, speed and lower cost of production, the induction of both cellular and humoral immunity, and lack of interaction with the genomic DNA. While some messenger RNA vaccines, such as the Pfizer–BioNTech COVID-19 vaccine, have the disadvantage of requiring ultracold storage before distribution, other mRNA vaccines, such as the Moderna, CureVac, and Walvax COVID-19 vaccines, do not have such requirements. In RNA therapeutics, messenger RNA vaccines have attracted considerable interest as COVID-19 vaccines. In December 2020, Pfizer–BioNTech and Moderna obtained authorization for their mRNA-based COVID-19 vaccines. On 2 December, the UK Medicines and Healthcare products Regulatory Agency (MHRA) became the first medicines regulator to approve an mRNA vaccine, authorizing the Pfizer–BioNTech vaccine for widespread use. On 11 December, the US Food and Drug Administration (FDA) issued an emergency use authorization for the Pfizer–BioNTech vaccine and a week later similarly authorized the Moderna vaccine.
  • 2.5K
  • 16 Nov 2022
Topic Review
Pharmacy Technician
A pharmacy technician is a title-protected, licensed health care provider who performs pharmacy-related functions, working collaboratively with a licensed pharmacist.
  • 2.5K
  • 30 Nov 2022
Topic Review
The Oxytocin System in the Brain
Research on oxytocin (OT) was pioneered in the 1920s by German anatomist Ernst Scharrer, after he identified unusual, large-shaped “glandule-like” cells in the hypothalamus of fish. A full anatomical, morphological and functional assessment would follow in the next 50 years, complemented by the Nobel-prize awarded for the synthesis of OT to Vincent du Vigneaud in 1955.
  • 2.5K
  • 09 Dec 2022
Topic Review
Fludeoxyglucose (18F)
Fluorodeoxyglucose (18F) (INN), or fluorodeoxyglucose F 18 (USAN and USP), also commonly called fluorodeoxyglucose and abbreviated [18F]FDG, 18F-FDG or FDG, is a radiopharmaceutical used in the medical imaging modality positron emission tomography (PET). Chemically, it is 2-deoxy-2-[18F]fluoro-D-glucose, a glucose analog, with the positron-emitting radionuclide fluorine-18 substituted for the normal hydroxyl group at the C-2 position in the glucose molecule. The uptake of 18F-FDG by tissues is a marker for the tissue uptake of glucose, which in turn is closely correlated with certain types of tissue metabolism. After 18F-FDG is injected into a patient, a PET scanner can form two-dimensional or three-dimensional images of the distribution of 18F-FDG within the body. Since its development in 1976, 18F-FDG had a profound influence on research in the neurosciences. The subsequent discovery in 1980 that 18F-FDG accumulates in tumors underpins the evolution of PET as a major clinical tool in cancer diagnosis. 18F-FDG is now the standard radiotracer used for PET neuroimaging and cancer patient management. The images can be assessed by a nuclear medicine physician or radiologist to provide diagnoses of various medical conditions.
  • 2.5K
  • 10 Oct 2022
Topic Review
Argiudolls of the Argentina
Argiudolls are a Great group of Mollisols, which are key components in the provision of ecosystem services associated with global food production. These soils act as support for different anthropic activities and are involved in the regulation of water quality and quantity, nutrient recycling, carbon reserve and maintenance of biodiversity.
  • 2.5K
  • 12 Jan 2021
Topic Review
Diversity of Allanblackia parviflora A. Chev. in Ghana
Allanblackia parviflora A. Chev. is an indigenous tree species that are found in West African rainforest zones. It is an underutilized fruit tree species that have been targeted for improvement as part of efforts to domesticate high-value indigenous multi-purpose trees for fruit and seed production in Africa. Allanblackia has several benefits, such as providing shade, timber, and medicine; however, the production of edible oil from its seeds is the economically most important use. There is evidence that the Allanblackia seed oil, which is used for cooking, the production of margarine and the manufacturing of ointments and soap, is being developed as a new agri-business in Ghana, Nigeria, Cameroon, and Tanzania. Despite the nutritional and socio-economic importance of A. parviflora, it is still at the early stages of its domestication process.
  • 2.5K
  • 08 Jan 2022
Topic Review
Trauma-Related Internalizing and Externalizing Behaviors in Adolescence
The adolescent brain is an open window on the environment, which is vulnerable to perturbations and the traumatic experiences occurring before or during this period have an increased saliency in affecting cognitive, emotional, and social levels. During adolescence, trauma-related effects causing significant impairment or suffering could be manifest in internalizing and externalizing behaviors. 
  • 2.5K
  • 29 Sep 2022
Topic Review
Genetic Use Restriction Technology
Genetic use restriction technology (GURT), also known as terminator technology or suicide seeds, is the name given to proposed methods for restricting the use of genetically modified crops by activating (or deactivating) some genes only in response to certain stimuli, especially to cause second generation seeds to be infertile. The development and application of GURTs is primarily an attempt by private sector agricultural breeders to increase the extent of protection on their innovations. The technology was originally developed under a cooperative research and development agreement between the Agricultural Research Service of the United States Department of Agriculture and Delta and Pine Land company in the 1990s and is not yet commercially available. GURT was first reported on by the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) to the UN Convention on Biological Diversity and discussed during the 8th Conference of the Parties to the United Nations Convention on Biological Diversity in Curitiba, Brazil, March 20–31, 2006.
  • 2.5K
  • 29 Nov 2022
  • Page
  • of
  • 2727
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