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Topic Review
Olfaction and Ligand–Receptor Interaction
Odorant or olfactory receptors (ORs) are located in the human nose, in the olfactory epithelium. The olfactory receptors can recognize many different odor molecules of a diverse protein sequence, and OR genes constitute the most abundant family of G protein-coupled receptors (GPCRs). The human receptor gene family comprises 339 receptor genes and 297 receptor pseudogenes, unequally dispersed in 51 distinct loci on 21 human chromosomes. Humans have a compassionate sense of smell, which is essential for discovering odors necessary for maintaining a healthy life, such as the smell of smoke (detection of fire) and rotten food (to avoid ingestion).
  • 8.5K
  • 25 Sep 2023
Topic Review
Correlation and Dependence
In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. In the broadest sense correlation is any statistical association, though it commonly refers to the degree to which a pair of variables are linearly related. Familiar examples of dependent phenomena include the correlation between the height of parents and their offspring, and the correlation between the price of a good and the quantity the consumers are willing to purchase, as it is depicted in the so-called demand curve. Correlations are useful because they can indicate a predictive relationship that can be exploited in practice. For example, an electrical utility may produce less power on a mild day based on the correlation between electricity demand and weather. In this example, there is a causal relationship, because extreme weather causes people to use more electricity for heating or cooling. However, in general, the presence of a correlation is not sufficient to infer the presence of a causal relationship (i.e., correlation does not imply causation). Formally, random variables are dependent if they do not satisfy a mathematical property of probabilistic independence. In informal parlance, correlation is synonymous with dependence. However, when used in a technical sense, correlation refers to any of several specific types of mathematical operations between the tested variables and their respective expected values. Essentially, correlation is the measure of how two or more variables are related to one another. There are several correlation coefficients, often denoted [math]\displaystyle{ \rho }[/math] or [math]\displaystyle{ r }[/math], measuring the degree of correlation. The most common of these is the Pearson correlation coefficient, which is sensitive only to a linear relationship between two variables (which may be present even when one variable is a nonlinear function of the other). Other correlation coefficients – such as Spearman's rank correlation – have been developed to be more robust than Pearson's, that is, more sensitive to nonlinear relationships. Mutual information can also be applied to measure dependence between two variables.
  • 8.5K
  • 14 Oct 2022
Topic Review
Compass Card (TransLink)
The Compass Card is a contactless smart card payment system primarily used for public transit in Metro Vancouver, British Columbia, Canada. It is operated by TransLink. Riders purchase a Compass Card and add fare value online, by phone, or at vending machines located at SeaBus terminals, SkyTrain and West Coast Express stations. Vending machines are also available at 18 participating London Drugs retail store locations. Compass Cards were deployed in August 2015. Full deployment for the general public took place on November 2, 2015. Since April 4, 2016, Compass Cards and Tickets have been required for all trips taken on the SkyTrain, SeaBus, and West Coast Express. In June 2016, TransLink reported that 100 percent of monthly pass users and 95 percent of all other users have switched over to the new format, totalling more than 915,000 customers.
  • 8.5K
  • 14 Oct 2022
Topic Review
Mediterranean Climate
A Mediterranean climate /ˌmɛdɪtəˈreɪniən/ or dry summer climate is characterized by dry summers and mild, wet winters. The climate receives its name from the Mediterranean Basin, where this climate type is most common. Mediterranean climate zones are typically located along the western sides of continents, between roughly 30 and 45 degrees north and south of the equator. The main cause of Mediterranean, or dry summer climate, is the subtropical ridge which extends northwards during the summer and migrates south during the winter due to increasing north-south temperature differences. The resulting vegetation of Mediterranean climates are the garrigue or maquis in the Mediterranean Basin, the chaparral in California, the fynbos in South Africa, the mallee in Australia, and the matorral in Chile. Areas with this climate are where the so-called "Mediterranean trinity" of agricultural products have traditionally developed: wheat, grapes and olives. Most historic cities of the Mediterranean basin lie within Mediterranean climatic zones, including Algiers, Athens, Barcelona, Beirut, İzmir, Jerusalem, Marseille, Naples, Rome, Tunis, Valencia, and Valletta. Major cities with Mediterranean climates outside of the Mediterranean basin include Adelaide, Cape Town, Casablanca, Dushanbe, Lisbon, Los Angeles , Perth, Porto, Sacramento, San Diego, San Francisco , San Jose, CA, Santiago, Tashkent and Victoria.
  • 8.5K
  • 07 Nov 2022
Topic Review
Expectation–Disconfirmation Theory and Brand
Combining brand equity indicators with Expectation–Disconfirmation Theory (EDT) provides insight into the hardly measurable influential variables of brand loyalty and brand equity evaluation. The results suggest that the satisfaction level (i.e., product evaluation) can be explained in more depth by the divided response shift indicator in the case of a familiar, low involvement product such as mineral water. It can be stated that the positive and negative disconfirmations of the response shift, which measures the weight of a brand in the overall evaluation of a product, can provide accurate information for brand managers.
  • 8.5K
  • 26 Jul 2022
Topic Review
Agrivoltaic System
Agrivoltaic systems (AVS) offer a symbiotic strategy for co-location sustainable renewable energy and agricultural production. This is particularly important in densely populated developing and developed countries, where renewable energy development is becoming more important; however, profitable farmland must be preserved. As emphasized in the Food-Energy-Water (FEW) nexus, AVS advancements should not only focus on energy management, but also agronomic management (crop and water management). 
  • 8.5K
  • 05 Sep 2021
Topic Review
List of Phobias
The English suffixes -phobia, -phobic, -phobe (from Greek φόβος phobos, "fear") occur in technical usage in psychiatry to construct words that describe irrational, abnormal, unwarranted, persistent, or disabling fear as a mental disorder (e.g. agoraphobia), in chemistry to describe chemical aversions (e.g. hydrophobic), in biology to describe organisms that dislike certain conditions (e.g. acidophobia), and in medicine to describe hypersensitivity to a stimulus, usually sensory (e.g. photophobia). In common usage, they also form words that describe dislike or hatred of a particular thing or subject (e.g. homophobia). The suffix is antonymic to -phil-. For more information on the psychiatric side, including how psychiatry groups phobias such as agoraphobia, social phobia, or simple phobia, see phobia. The following lists include words ending in -phobia, and include fears that have acquired names. In some cases, the naming of phobias has become a word game, of notable example being a 1998 humorous article published by BBC News. In some cases, a word ending in -phobia may have an antonym with the suffix -phil-, e.g. Germanophobe/Germanophile. Many -phobia lists circulate on the Internet, with words collected from indiscriminate sources, often copying each other. Also, a number of psychiatric websites exist that at the first glance cover a huge number of phobias, but in fact use a standard text to fit any phobia and reuse it for all unusual phobias by merely changing the name. Sometimes it leads to bizarre results, such as suggestions to cure "prostitute phobia". Such practice is known as content spamming and is used to attract search engines. An article published in 1897 in American Journal of Psychology noted "the absurd tendency to give Greek names to objects feared (which, as Arndt says, would give us such terms as klopsophobia – fear of thieves, triakaidekaphobia – fear of the number 13....)".
  • 8.5K
  • 07 Nov 2022
Topic Review
Microbial-Induced Calcite Precipitation
Microbial-induced calcite precipitation (MICP) is a process that uses naturally occurring bacteria to bind soil particles together through calcium carbonate (CaCO3) precipitation. It is a promising new technology in the area of Civil Engineering with the potential to become a cost-effective, environmentally friendly, and sustainable solution to many problems such as ground improvement, liquefaction remediation, enhancing properties of concrete, and so forth. 
  • 8.5K
  • 29 Oct 2020
Topic Review
History of Virology
The history of virology — the scientific study of viruses and the infections they cause – began in the closing years of the 19th century. Although Louis Pasteur and Edward Jenner developed the first vaccines to protect against viral infections, they did not know that viruses existed. The first evidence of the existence of viruses came from experiments with filters that had pores small enough to retain bacteria. In 1892, Dmitry Ivanovsky used one of these filters to show that sap from a diseased tobacco plant remained infectious to healthy tobacco plants despite having been filtered. Martinus Beijerinck called the filtered, infectious substance a "virus" and this discovery is considered to be the beginning of virology. The subsequent discovery and partial characterization of bacteriophages by Frederick Twort and Félix d'Herelle further catalyzed the field, and by the early 20th century many viruses had been discovered. In 1926, Thomas Milton Rivers defined viruses as obligate parasites. Viruses were demonstrated to be particles, rather than a fluid, by Wendell Meredith Stanley, and the invention of the electron microscope in 1931 allowed their complex structures to be visualised.
  • 8.4K
  • 31 Oct 2022
Topic Review
Salamanders in Folklore
The salamander is an amphibian of the order Urodela which, as with many real creatures, often has been ascribed fantastic and sometimes occult qualities by pre-modern authors (as in the allegorical descriptions of animals in medieval bestiaries) not possessed by the real organism. The legendary salamander is often depicted as a typical salamander in shape with a lizard-like form, but is usually ascribed an affinity with fire, sometimes specifically elemental fire.
  • 8.4K
  • 17 Oct 2022
Topic Review
Mango (Mangifera indica L.) Leaves
Mango (Mangifera indica L.) ascribed to the family Anacardiaceae has been adjudged as the vital traditionally significant and one of the most economically important tropical fruit crop globally.
  • 8.4K
  • 28 May 2021
Topic Review
Mass Transfer in Packed-Bed Columns
This review provides a thorough analysis of the most famous mass transfer models for random and structured packed-bed columns used in absorption/stripping and distillation processes, providing an overview of the equations to calculate the mass transfer parameters, i.e.: gas-side coefficient per unit surface ky [kmol·m-2·s-1], liquid-side coefficient per unit surface kx [kmol·m-2·s-1], interfacial packing area ae [m2·m-3], which constitute the ingredients to assess the mass transfer rate of packed-bed columns. This work also provides the ranges of model validity and applicability together with their main pros and cons and the criticalities behind these models, which mostly rely on the assessment of fluid-dynamics parameters such as liquid film thickness, liquid hold-up and interfacial area, or the real liquid paths or any mal-distributions flow. 
  • 8.4K
  • 01 Sep 2021
Topic Review
Tandem Mass Spectrometry
Tandem mass spectrometry, also known as MS/MS or MS2, involves multiple steps of mass spectrometry selection, with some form of fragmentation occurring in between the stages. In a tandem mass spectrometer, ions are formed in the ion source and separated by mass-to-charge ratio in the first stage of mass spectrometry (MS1). Ions of a particular mass-to-charge ratio (precursor ions) are selected and fragment ions (product ions) are created by collision-induced dissociation, ion-molecule reaction, photodissociation, or other process. The resulting ions are then separated and detected in a second stage of mass spectrometry (MS2).
  • 8.4K
  • 19 Oct 2022
Topic Review
Fresh Fruit Supply Chain Optimization
The fresh fruit chain has been recognized as a very important and strategic part of the economic development of many countries. The planning framework for production and distribution is highly complex as a result. Mathematical models have been developed over the decades to deal with this complexity. This review focuses on the recent progress in mathematically based decision making to account for uncertainties in the fresh fruit supply chain
  • 8.4K
  • 27 Jul 2021
Topic Review
Lewis's Trilemma
Lewis's trilemma is an apologetic argument traditionally used to argue for the divinity of Jesus by arguing that the only alternatives were that he was evil or deluded. One version was popularised by University of Oxford literary scholar and writer C. S. Lewis in a BBC radio talk and in his writings. It is sometimes described as the "Lunatic, Liar, or Lord", or "Mad, Bad, or God" argument. It takes the form of a trilemma — a choice among three options, each of which is in some way difficult to accept. This argument is very popular with Christian apologists, although some theologians and biblical scholars do not view Jesus as having claimed to be God. Some argue that he identified himself as a divine agent, with a unique relationship to Israel's God. Others see him as wanting to direct attention to the divine kingdom he proclaimed.
  • 8.4K
  • 10 Nov 2022
Topic Review
Leucaena leucocephala as Protein Source
White leadtree or Leucaena (Leucaena leucocephala) (), also known as ipil-ipil, is native to Central America and has spread and/or naturalized all over the World at a latitude between 30° N and 30° S due to a shrub variety used as a shade tree for coffee, cocoa, hemp plantations, pepper, vanilla, and other essences.
  • 8.4K
  • 04 Aug 2021
Topic Review
Post-transition Metal
Post-transition metals are a set of metallic elements in the periodic table located between the transition metals to their left, and the metalloids to their right. Depending on where these adjacent groups are judged to begin and end, there are at least five competing proposals for which elements to include: the three most common contain six, ten and thirteen elements, respectively (see image). All proposals include gallium, indium, tin, thallium, lead, and bismuth. Physically, post-transition metals are soft (or brittle), have poor mechanical strength, and have melting points lower than those of the transition metals. Being close to the metal-nonmetal border, their crystalline structures tend to show covalent or directional bonding effects, having generally greater complexity or fewer nearest neighbours than other metallic elements. Chemically, they are characterised—to varying degrees—by covalent bonding tendencies, acid-base amphoterism and the formation of anionic species such as aluminates, stannates, and bismuthates (in the case of aluminium, tin, and bismuth, respectively). They can also form Zintl phases (half-metallic compounds formed between highly electropositive metals and moderately electronegative metals or metalloids). The name is universally used, but not officially sanctioned by any organization such as the IUPAC. The origin of the term is unclear: one early use was in 1940 in a chemistry text. Alternate names for this group are B-subgroup metals, other metals, and p-block metals; and at least thirteen other labels.
  • 8.4K
  • 21 Nov 2022
Topic Review
Turbocharged Direct Injection
Turbocharged direct injection or TDI is a design of turbodiesel engines featuring turbocharging and cylinder-direct fuel injection that was developed and produced by the Volkswagen Group (VW AG). These TDI engines are widely used in all mainstream Volkswagen Group marques of passenger cars and light commercial vehicles made by the company (particularly those sold in Europe). They are also used as marine engines in Volkswagen Marine and Volkswagen Industrial Motor applications. TDI engines installed in 2009 to 2015 model year Volkswagen Group cars sold through 18 September 2015 had an emissions defeat device, which activated emissions controls only during emissions testing. The emissions controls were suppressed otherwise, allowing the TDI engines to exceed legal limits on emissions. VW has admitted to using the illegal device in its TDI diesel cars. In many countries, TDI is a registered trademark of Volkswagen AG. The TDI designation has also been used on vehicles powered by Land Rover-designed diesel engines. These are unrelated to Volkswagen Group engines.
  • 8.4K
  • 08 Nov 2022
Topic Review
Phenomenology
Phenomenology (from Greek φαινόμενον, phainómenon "that which appears" and λόγος, lógos "study") is the philosophical study of the structures of experience and consciousness. As a philosophical movement it was founded in the early years of the 20th century by Edmund Husserl and was later expanded upon by a circle of his followers at the universities of Göttingen and Munich in Germany . It then spread to France , the United States , and elsewhere, often in contexts far removed from Husserl's early work. Phenomenology is not a unified movement; rather, the works of different authors share a 'family resemblance' but with many significant differences. Gabriella Farina states:Phenomenology, in Husserl's conception, is primarily concerned with the systematic reflection on and study of the structures of consciousness and the phenomena that appear in acts of consciousness. Phenomenology can be clearly differentiated from the Cartesian method of analysis which sees the world as objects, sets of objects, and objects acting and reacting upon one another. Husserl's conception of phenomenology has been criticized and developed not only by him but also by students and colleagues such as Edith Stein, Max Scheler, Roman Ingarden, and Dietrich von Hildebrand, by existentialists such as Nicolai Hartmann, Gabriel Marcel, Maurice Merleau-Ponty, and Jean-Paul Sartre, by hermeneutic philosophers such as Martin Heidegger, Hans-Georg Gadamer, and Paul Ricoeur, by later French philosophers such as Jean-Luc Marion, Michel Henry, Emmanuel Levinas, and Jacques Derrida, by sociologists such as Alfred Schütz and Eric Voegelin, and by Christian philosophers, such as Dallas Willard.
  • 8.4K
  • 28 Nov 2022
Topic Review
Biomass Gasification
Lignocellulosic gasification is a valid thermochemical approach for the conversion of organic solid matter into a gaseous mixture that is constituted of hydrogen, carbon monoxide, carbon dioxide and methane, named synthetic gas or syngas. Although about 55% of syngas is still produced from coal, biomass utilization, especially lignocellulose, is constantly growing. Indeed, gasification could be potentially applied to all different kinds of lignocellulosic biomass, unlike other conversion technologies. Moreover, in the last few decades, a wide range of applications of syngas have been intensively studied. Syngas can be directly used as a combustible substance in power plants for heat and power production (steam cycle, co-combustion, combustion in gas turbines or internal combustion engines, high temperature fuel cells), which represents the most common use of biomass-derived syngas. However, syngas also represents a platform that can be employed in a broad range of chemical and microbial processes, leading to gaseous and liquid fuels, as well as to chemicals. Chemical process research has mainly focused on transportation fuel production from syngas, such as Fischer–Tropsch liquid fuels, hydrogen, methanol, dimethyl ether (DME), mixed alcohols, and synthetic natural gas (SNG). Instead, the biochemical conversion route consists of syngas fermentation in which obligate anaerobic microorganisms convert syngas into organic acids, alcohols, and other chemicals. The most commonly used microorganisms are acetogens, which use the Wood–Ljungdahl metabolic pathway. Syngas fermentation is defined as an indirect fermentation process because biomass is not fed directly into the fermenter, but it is previously converted into syngas through gasification. 
  • 8.4K
  • 17 Dec 2020
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