Aidon

Aidon Oy is a Finnish technology company that focuses on smart grid and smart metering solutions and services in the Nordics. Founded in 2004, it is headquartered in Jyväskylä, Finland, with offices in Finland, Sweden, Norway and Denmark.
On November 9, 2023, Gridspertise completed the acquisition of the company.


Broadband over power lines

Broadband over power lines (BPL) is a method of power-line communication (PLC) that allows relatively high-speed digital data transmission over public electric power distribution wiring. BPL uses higher frequencies, a wider frequency range, and different technologies compared to other forms of power-line communications to provide high-rate communication over longer distances. BPL uses frequencies that are part of the radio spectrum allocated to over-the-air communication services; therefore, the prevention of interference to, and from, these services is a very important factor in designing BPL systems.
There are two main categories of BPL: in-house and access. In-house BPL is broadband access within a building or structure using the electric lines of the structure to provide the network infrastructure. Access BPL is the use of electrical transmission lines to deliver broadband to the home. Access BPL is considered a viable alternative to cable or DSL to provide the 'last mile' of broadband to end users.

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Commonwealth Edison

Commonwealth Edison, commonly known by syllabic abbreviation as ComEd, is the largest electric utility in Illinois, and the primary electric provider in Chicago and much of Northern Illinois. Its service territory stretches roughly from  Iroquois County on the south to the Wisconsin border on the north and from the Iowa border on the west to the Indiana border on the east.  For more than 100 years, Commonwealth Edison has been the primary electric delivery services company for Northern Illinois. Today, ComEd is a unit of Chicago-based Exelon Corporation, one of the nation's largest electric and gas utility holding companies. ComEd provides electric service to more than 3.8 million customers across Northern Illinois. The company's revenues totaled more than $7 billion in 2023.
As of 2015, ComEd has interconnections with We Energies, ITC Midwest, Ameren, American Electric Power, Northern Indiana Public Service, and MidAmerican Energy Company (MEC).

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Contingency (electrical grid)

In an electrical grid, contingency is an unexpected failure of a single principal component (e.g., an electrical generator or a power transmission line) that causes the change of the system state large enough to endanger the grid security. Some protective relays are set up in a way that multiple individual components are disconnected due to a single fault, in this case, taking out all the units in a group counts as a single contingency. A scheduled outage (like maintenance) is not a contingency.
The choice of term emphasizes the fact that a single fault can cause severe damage to the system so quickly that the operator will not have time to intervene, and therefore a reaction to every single fault has to be defensively pre-built into the system configuration. Some sources use the term interchangeably with "disturbance" and "fault".


Demand response

Demand response is a change in the power consumption of an electric utility customer to better match the demand for power with the supply. Until the 21st century decrease in the cost of pumped storage and batteries, electric energy could not be easily stored, so utilities have traditionally matched demand and supply by throttling the production rate of their power plants, taking generating units on or off line, or importing power from other utilities. There are limits to what can be achieved on the supply side, because some generating units can take a long time to come up to full power, some units may be very expensive to operate, and demand can at times be greater than the capacity of all the available power plants put together. Demand response, a type of energy demand management, seeks to adjust in real-time the demand for power instead of adjusting the supply.
Utilities may signal demand requests to their customers in a variety of ways, including simple off-peak metering, in which power is cheaper at certain times of the day, and smart metering, in which explicit requests or changes in price can be communicated to customers.
The customer may adjust power demand by postponing some tasks that require large amounts of electric power, or may decide to pay a higher price for their electricity. Some customers may switch part of their consumption to alternate sources, such as on-site solar panels and batteries.
In many respects, demand response can be put simply as a technology-enabled economic rationing system for electric power supply. In demand response, voluntary rationing is accomplished by price incentives—offering lower net unit pricing in exchange for reduced power consumption in peak periods. The direct implication is that users of electric power capacity not reducing usage (load) during peak periods will pay "surge" unit prices, whether directly, or factored into general rates.
Involuntary rationing, if employed, would be accomplished via rolling blackouts during peak load periods. Practically speaking, summer heat waves and winter deep freezes might be characterized by planned power outages for consumers and businesses if voluntary rationing via incentives fails to reduce load adequately to match total power supply.


EPB

EPB of Chattanooga, formerly known as the Electric Power Board of Chattanooga, is an American electric power distribution and telecommunication company owned by the city of Chattanooga, Tennessee. EPB serves nearly 180,000 homes and businesses in a 600-square mile area in the greater Chattanooga area and Hamilton County. In 2010, EPB was the first company in the United States to offer 1 Gbit/s high-speed internet over a fiber optic network, over 200 times faster than the national average. As a result, Chattanooga has been called "Gig City" and held up as a national model for deploying the world's fastest internet and the most advanced Smart Grid electric distribution system in the United States. On October 15, 2015, Chattanooga implemented the world's first community-wide 10-gig Internet service.
In 1935, an act of the Tennessee Legislature established EPB as an independent board of the City of Chattanooga to provide electric power to the Greater Chattanooga area. EPB began serving their customers in 1939.


Electrical grid

An electrical grid (or electricity network) is an interconnected network for electricity delivery from producers to consumers. Electrical grids consist of power stations, electrical substations to step voltage up or down, electric power transmission to carry power over long distances, and finally electric power distribution to customers. In that last step, voltage is stepped down again to the required service voltage. Power stations are typically built close to energy sources and far from densely populated areas. Electrical grids vary in size and can cover whole countries or continents. From small to large there are microgrids, wide area synchronous grids, and super grids. The combined transmission and distribution network is part of electricity delivery, known as the power grid.
Grids are nearly always synchronous, meaning all distribution areas operate with three phase alternating current (AC) frequencies synchronized (so that voltage swings occur at almost the same time). This allows transmission of AC power throughout the area, connecting the electricity generators with consumers. Grids can enable more efficient electricity markets.
Although electrical grids are widespread, as of 2016, 1.4 billion people worldwide were not connected to an electricity grid. As electrification increases, the number of people with access to grid electricity is growing. About 840 million people (mostly in Africa), which is ca. 11% of the World's population, had no access to grid electricity in 2017, down from 1.2 billion in 2010.
Electrical grids can be prone to malicious intrusion or attack; thus, there is a need for electric grid security. Also as electric grids modernize and introduce computer technology, cyber threats start to become a security risk. Particular concerns relate to the more complex computer systems needed to manage grids.


Electrical grid security in the United States involves the physical and cybersecurity of the United States electrical grid. The smart grid allows energy customers and energy providers to more efficiently manage and generate electricity. Similar to other new technologies, the smart grid also introduces new security concerns.
The electric utility industry in the U.S. leads several initiatives to help protect the national electric grid from threats. The industry partners with the federal government, particularly the National Institute of Standards and Technology, the North American Electric Reliability Corporation, and federal intelligence and law enforcement agencies.
From the 2000s through to the 2020s, the security of the U.S. electrical grid has come into question. Government officials have expressed concern with the possibility of violent extremists and agents of foreign states attacking the nation's electrical grid. Cybersecurity is also an issue for electric grid security in the United States with financially motivated crimes being more common than terrorist ones.


Enel

Enel S.p.A. is an Italian multinational producer and distributor of electricity and gas. Enel was first established as a public body at the end of 1962, and then transformed into a limited company in 1992. In 1999, following the liberalisation of the electricity market in Italy, Enel was privatised. The Italian state, through the Ministry of Economy and Finance, is the main shareholder, with 23.6% of the share capital as of 31 December 2024.

The company is quoted on the FTSE MIB index on the Borsa Italiana.


Fluentgrid

Fluentgrid Limited (formerly Phoenix IT Solutions Limited) is an Indian enterprise software company headquartered in Visakhapatnam, Andhra Pradesh, that develops digital platforms for electricity, water and gas utilities, as well as smart city and public infrastructure projects. Founded on 4 December 1998 by Murali Krishna Gannamani, the company operated as Phoenix IT Solutions Limited until adopting its current name in December 2015.
Its software has been deployed in utility and public-sector digital transformation projects, including the Integrated Command and Control Centre (ICCC) for the Greater Visakhapatnam Municipal Corporation (GVMC), a cloud-based customer billing platform for Uttar Pradesh Power Corporation Limited (UPPCL), and COVID-19 response systems developed for the Visakhapatnam district administration in 2020.
The company has received industry recognition including the IBM Beacon Award (2012) and the Fierce Innovation Award for Energy (2015). Its software development organisation achieved Capability Maturity Model Integration (CMMI) Maturity Level 5 in 2017, and in 2025 Fluentgrid was recognised as a Major Player in the International Data Corporation (IDC) MarketScape assessment of worldwide utility meter data management system vendors.


G.hn

Gigabit Home Networking (G.hn) is a specification for wired home networking that supports speeds up to 2 Gbit/s and operates over four types of legacy wires: telephone wiring, coaxial cables, power lines and plastic optical fiber. Some benefits of a multi-wire standard are lower equipment development costs and lower deployment costs for service providers (by allowing customer self-install).


Grid

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GridLAB-D

GridLAB-D is an open-source (BSD license) simulation and analysis tool that models emerging smart grid energy technologies. It couples power flow calculations with distribution automation models, building energy use and appliance demand models, and market models.  It is used primarily to estimate the benefits and impacts of smart grid technology.


GridPoint

GridPoint is an American clean technology company based in Reston, Virginia, that provides energy management and sustainability services to enterprises and government agencies, such as electric utilities.
GridPoint services include building management systems, equipment-level submetering and monitoring hardware, software analytics, and related energy management services.


Grid energy storage

Grid energy storage, also known as large-scale energy storage, is a set of technologies connected to the electrical power grid that store energy for later use. These systems help balance supply and demand by storing excess electricity from variable renewables such as solar and inflexible sources like nuclear power, releasing it when needed. They further provide essential grid services, such as helping to restart the grid after a power outage.
As of 2023, the largest form of grid storage is pumped-storage hydroelectricity, with utility-scale batteries and behind-the-meter batteries coming second and third. Lithium-ion batteries are well suited for short-duration storage (under 8 hours), due to their lower cost and sensitivity to degradation at high states of charge. Flow batteries and compressed air energy storage may provide storage for medium-duration. Two forms of storage are suited for long-duration storage: green hydrogen, produced via electrolysis and thermal energy storage.
Energy storage is one option to making grids more flexible. Another solution is the use of more dispatchable power plants that can change their output rapidly, for instance peaking power plants to fill in supply gaps. Demand response can shift load to other times and interconnections between regions can balance out fluctuations in renewables production.
The price of storage technologies typically goes down with experience. For instance, lithium-ion batteries have been getting some 20% cheaper for each doubling of worldwide capacity. Systems with under 40% variable renewables need only short-term storage. At 80%, medium-duration storage becomes essential and beyond 90%, long-duration storage does too. The economics of long-duration storage is challenging, and alternative flexibility options like demand response may be more economic.


Home automation

Home automation or domotics is building automation for a home. A home automation system will monitor and/or control home attributes such as lighting, climate, entertainment systems, and appliances. It may also include home security such as access control and alarm systems.
The phrase smart home refers to home automation devices that have internet access.  Home automation, a broader category, includes any device that can be monitored or controlled via wireless radio signals, not just those having internet access.  When connected with the Internet, home sensors and activation devices are an important constituent of the Internet of Things ("IoT").
A home automation system typically connects controlled devices to a central smart home hub (sometimes called a "gateway"). The user interface for control of the system uses either wall-mounted terminals, tablet or desktop computers, a mobile phone application, or a Web interface that may also be accessible off-site through the Internet.

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IEEE Smart Grid

IEEE Smart Grid is an initiative launched by IEEE to help provide expertise and guidance for individuals and organizations involved in the modernization and optimization of the power grid, better known as the "smart grid". IEEE Smart Grid encompasses an array of activities, including development of new smart grid-related standards, best practices, publications, and conferences and educational opportunities.


Iberdrola

Iberdrola, S.A. (Spanish pronunciation: [iβeɾˈðɾola]) is a Spanish multinational electric utility company based in Bilbao, Spain. It has  around 40,000 employees and serves around 30 million customers.
Subsidiaries include ScottishPower (United Kingdom), Avangrid (United States) and Neoenergia (Brazil), amongst others.  As of 2023, the largest shareholder of the company is the Qatar Investment Authority, with BlackRock and Norges Bank (managers of the Norwegian Government Pension Fund Global) also holding significant interests.
Iberdrola is the largest producer of wind power, and the world's second largest electricity utility by market capitalisation. As of 2023, the company operates a capacity of 62,045 MW, of which 41,246 MW are from renewable sources worldwide.


Inverter-based resource

An inverter-based resource (IBR) is a source of electricity that is asynchronously connected to the electrical grid via an electronic power converter ("inverter"). The devices in this category, also known as converter interfaced generation (CIG) and power electronic interface source, include the variable renewable energy generators (wind, solar) and energy storages such as battery, super capacitors, etc.. These devices lack the intrinsic behaviors (like the inertial response of a synchronous generator) and their features are almost entirely defined by the control algorithms, presenting specific challenges to system stability as their penetration increases, for example, a single software fault can affect all devices of a certain type in a contingency (cf. section on Blue Cut fire below). IBRs are sometimes called non-synchronous generators. The design of inverters for the IBR generally follows the IEEE 1547 and NERC PRC-024-2 standards.
The term unconventional sources includes IBRs as well as other generators that behave differently than synchronous generators.


KT Corporation

KT Corporation (Hangul: 주식회사 케이티), formerly Korea Telecom, is a South Korean telecommunications company, mobile network operator (MNO) and mobile virtual network operator (MVNO). KT is the large wireless carrier in South Korea, with 13.5 million subscribers as of Q4 2023.
The formerly fully-state-owned firm (the government's National Pension Service currently owns 12.19% shares and is the largest shareholder) is South Korea's first telecommunications company and is a major supplier of the local landline and broadband internet market, serving about 90 percent of the country's fixed-line subscribers and 45 percent of high-speed Internet users. After selling its wireless affiliate Korea Mobile Telecom in 1994, KT returned to the wireless market with the creation of PCS carrier KTF in January 1997.
The company's merger with KTF, its wireless subsidiary, in 2009 made it the country's ninth largest chaebol (conglomerate) with nearly 24 trillion won in assets as of 2009.
In January 2011, KT launched unified brand "Olleh" for both fixed-line and cellular broadband services. However in 2016, they decided to revert to "KT" for landline and cellular broadband services.


Korea Electric Power Corporation


North American power transmission grid


Off-the-grid


Open Smart Grid Protocol


Phasor measurement unit


Power-to-X


Power electronics

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Power system reliability


Recloser


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Short circuit ratio (electrical grid)


Silver Spring Networks


Smart Grid Energy Research Center


Smart Grid Interoperability Panel


Smart city


Smart grid


Smart grid in China


Smart grid in the United States


Smart grid policy of the United States


Smart grids by country


Smart grids in Austria


Smart grids in South Korea


Smart meter


State Grid Corporation of China


SuperSmart Grid


Super grid


Tata Power Delhi Distribution Limited


Unified Smart Grid


Vehicle-to-grid


Wide area synchronous grid


Agricultural microbiology

Agricultural microbiology is a branch of microbiology dealing with plant-associated microbes and plant and animal diseases. It also deals with the microbiology of soil fertility, such as microbial degradation of organic matter and soil nutrient transformations. The primary goal of agricultural microbiology is to comprehensively explore the interactions between beneficial microorganisms like bacteria and fungi with crops. It also deals with the microbiology of soil fertility, such as microbial degradation of organic matter and soil nutrient transformations.


Applied and Environmental Microbiology

Applied and Environmental Microbiology is a biweekly peer-reviewed scientific journal published by the American Society for Microbiology. It was established in 1953 as Applied Microbiology and obtained its current name in 1975. Articles older than six months are available free of cost from the website, however, the newly published articles within six months are available to subscribers only. According to the Journal Citation Reports, the journal has a 2024 impact factor of 3.7. The journal has been ranked as one of the top 100 journals over the past 100 years in the fields of biology and medicine. The editor-in-chief is Gemma Reguera (Michigan State University).


Archives of Microbiology

Archives of Microbiology (formerly Archiv für Mikrobiologie ISSN 0003-9276) is a peer-reviewed  scientific journal of microbiology established in 1930. It is edited by Yusuf Akhter, and published by Springer Berlin Heidelberg ten times per year.


BMC Microbiology

BMC Microbiology is a peer-reviewed open-access scientific journal that covers microorganisms and various aspects of microbiology. The journal was established in 2001 and is published by BioMed Central.
The associate editor is Vasco Giovagnetti.
The journal publishes research articles, reviews, and commentaries related to microorganisms, including bacteria, archaea, fungi, and viruses.


Bacteria

Bacteria are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in mutualistic, commensal and parasitic relationships with plants and animals. Most bacteria have not been characterised and there are many species that cannot be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology.
Like all animals, humans carry vast numbers (approximately 1013 to 1014) of bacteria. Most are in the gut, though there are many on the skin. Most of the bacteria in and on the body are harmless or rendered so by the protective effects of the immune system, and many are beneficial, particularly the ones in the gut. However, several species of bacteria are pathogenic and cause infectious diseases, including cholera, syphilis, anthrax, leprosy, tuberculosis, tetanus and bubonic plague. The most common fatal bacterial diseases are respiratory infections. Antibiotics are used to treat bacterial infections and are also used in farming, making antibiotic resistance a growing problem. Bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, the recovery of gold, palladium, copper and other metals in the mining sector (biomining, bioleaching), as well as in biotechnology, and the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes ("fission fungi"), bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells contain circular chromosomes, do not contain a nucleus and rarely harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two very different groups of organisms that evolved from an ancient common ancestor. These evolutionary domains are called Bacteria and Archaea. Unlike Archaea, bacteria contain ester-linked lipids in the cell membrane, possess elongation factors that are resistant to ADP-ribosylation by diphtheria toxin, use formylmethionine in protein synthesis initiation, and have numerous genetic differences, including a different 16S rRNA.


Branches of microbiology

The branches of microbiology can be classified into pure and applied sciences. Microbiology can be also classified based on taxonomy, in the cases of bacteriology, mycology, protozoology, and phycology. There is considerable overlap between the specific branches of microbiology with each other and with other disciplines, and certain aspects of these branches can extend beyond the traditional scope of microbiology
In general the field of microbiology can be divided in the more fundamental branch (pure microbiology) and the applied microbiology (biotechnology). In the more fundamental field the organisms are studied as the subject itself on a deeper (theoretical) level.
Applied microbiology refers to the fields where the micro-organisms are applied in certain processes such as brewing or fermentation. The organisms itself are often not studied as such, but applied to sustain certain processes.


Cellular microbiology

Cellular microbiology is a discipline that bridges microbiology and cell biology to investigate interactions between microorganisms and host cells at the molecular level.
Cellular microbiology attempts to use pathogenic microorganisms as tools for cell-biology research, and to employ cell-biology methods to understand the pathogenicity of microorganisms. Toxins and virulence factors from microbes have been used for decades to influence processes in eukaryotic cells and to study them. It has increasingly appeared that applying a purified toxin on a cell does not always provide the complete picture, and that understanding the role of the toxin in pathogenicity, the way the toxin promotes the microbe, the way the toxin is produced and the co-evolution of the toxin and its host-cell counterparts, is crucial.


Critical Reviews in Microbiology

Critical Reviews in Microbiology is an international, peer-reviewed academic journal that publishes comprehensive review articles covering all areas of medical microbiology. Areas covered by the journal include bacteriology, virology, microbial genetics, epidemiology, and diagnostic microbiology. It is published by Taylor and Francis Group.
As of 2024, the impact factor is 6.0.


Culturomics (microbiology)

Culturomics is the high-throughput cell culture of bacteria that aims to comprehensively identify strains or species in samples obtained from tissues such as the human gut or from the environment. This approach was conceived as an alternative, complementary method to metagenomics, which relies on the presence of homologous sequences to identify new bacteria. Due to the limited phylogenetic information available on bacteria, metagenomic data generally contains large amounts of "microbial dark matter", sequences of unknown origin. Culturomics provides some of the missing gaps with the added advantage of enabling the functional study of the generated cultures. Its main drawback is that many bacterial species remain effectively uncultivable until their growth conditions are better understood. Therefore, optimization of the culturomics approach has been done by improving culture conditions.
Unlike metagenomics, which relies on direct shotgun sequencing or 16S rRNA gene sequencing, culturomics is based on matrix-assisted laser desorption/ionization–time-of-flight (MALDI-TOF) mass spectrometry. However, culturomics also uses 16S RNA sequencing to identify new species.


Diagnostic microbiology

Diagnostic microbiology is the study of microbial identification. Since the discovery of the germ theory of disease, scientists have been finding ways to harvest specific organisms. Using methods such as differential media or genome sequencing, physicians and scientists can observe novel functions in organisms for more effective and accurate diagnosis of organisms. Methods used in diagnostic microbiology are often used to take advantage of a particular difference in organisms and attain information about what species it can be identified as, which is often through a reference of previous studies. New studies provide information that others can reference so that scientists can attain a basic understanding of the organism they are examining.


Enucleation (microbiology)

In the context of microbiology, enucleation refers to removing the nucleus of a cell. By replacing it with a different nucleus, this technique is used mainly in cloning but can also be used for creating hybrids of plants or animals. It was discovered that cells can be chemically enucleated with Cytochalasin B in 1967.


Environmental Microbiology

Environmental Microbiology is a monthly peer-reviewed scientific journal focused on microbial interactions and microbial processes in the environment. It is published by Wiley-Blackwell. Until January 2024, it was an official journal of the Society for Applied Microbiology (now known as Applied Microbiology International), but is now no longer affiliated with that society. According to the Journal Citation Reports, the journal has a 2024 impact factor of 4.0.


European Academy of Microbiology

The European Academy of Microbiology, generally abbreviated as EAM, is a European institution made up of about 150 microbiology scientists, founded in 2009.
The main objective of the Academy is to be the authoritative voice of microbiology in Europe and thus enhance the potential of microbiology and microbiologists in Europe and globally. The Federation of European Microbiology Societies (FEMS) founded and supports the EAM, and many EAM members collaborate with FEMS in various capacities (e.g. directors, editors in chief of FEMS journals, etc.). The President of the EAM as of 1 January 2021 is Jörg Vogel.


FEMS Microbiology Reviews

FEMS Microbiology Reviews is a peer-reviewed scientific journal publishing invited review articles in the field of microbiology. The journal was established in 1985, and is published by Oxford University Press on behalf of the Federation of European Microbiological Societies. The editors-in-chief are Karin Sauer, David Blackbourn, and Bart Thomma.


Flora (microbiology)

In microbiology, collective bacteria and other microorganisms in a host are historically known as flora. Although microflora is commonly used, the term microbiota is becoming more common as microflora is a misnomer. Flora pertains to the Kingdom Plantae. Microbiota includes Archaea, Bacteria, Fungi and Protists. Microbiota with animal-like characteristics can be classified as microfauna.


Food microbiology

Food microbiology is the study of the microorganisms that inhabit, create, or contaminate food. This includes the study of microorganisms causing food spoilage; pathogens that may cause disease (especially if food is improperly cooked or stored); microbes used to produce fermented foods such as cheese, yogurt, bread, beer, and wine; and microbes with other useful roles, such as producing probiotics.


Future Microbiology

Future Microbiology is a peer-reviewed medical journal that was established in 2006 and is published by Future Medicine. The editors-in-chief are Richard A. Calderone (Georgetown University) and Joseph M Blondeau (University of Saskatchewan). The journal covers all aspects of the microbiological sciences, including virology, bacteriology, parasitology, and mycology.


Hemolysis (microbiology)

Hemolysis is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms. This is particularly useful in classifying streptococcal species. A substance that causes hemolysis is called a hemolysin.


Impedance microbiology

Impedance microbiology is a microbiological technique used to measure the microbial number density (mainly bacteria but also yeasts) of a sample by monitoring the electrical parameters of the growth medium. The ability of microbial metabolism to change the electrical conductivity of the growth medium was discovered by Stewart and further studied by other scientists such as Oker-Blom, Parson and Allison in the first half of 20th century. However, it was only in the late 1970s that, thanks to computer-controlled systems used to monitor impedance, the technique showed its full potential, as discussed in the works of Fistenberg-Eden & Eden, Ur & Brown and Cady.


Indian Journal of Medical Microbiology

The Indian Journal of Medical Microbiology is a peer-reviewed open-access medical journal published by Medknow Publications on behalf of the Indian Association of Medical Microbiology. The journal publishes articles on  medical microbiology including bacteriology, virology, mycology, and parasitology.


Industrial microbiology


Instruments used in microbiology


International Journal of Food Microbiology


International Journal of Systematic and Evolutionary Microbiology


International Microbiology


Isolation (microbiology)


Journal of Basic Microbiology


Journal of Medical Microbiology


Medical microbiology


Microbiological culture


Microbiology


Microbiology (journal)


Microbiology Outreach Prize


Microbiology Society

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Microbiology Spectrum


Microbiology and Molecular Biology Reviews


Microbiology of decomposition


Microorganism


Molecular biology

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Nature Microbiology


Nature Reviews Microbiology


Pathogens and Disease


Petroleum microbiology


Pharmaceutical microbiology


Pleomorphism (microbiology)


Priming (microbiology)


Society for Industrial Microbiology and Biotechnology


Soil microbiology


Streaking (microbiology)


Wuhan Institute of Virology


Alexandrov topology

In general topology, an Alexandrov topology is a topology in which the intersection of an arbitrary family of open sets is open (while the definition of a topology only requires this for a finite family). Equivalently, an Alexandrov topology is one whose open sets are the upper sets for some preorder on the space.
Spaces with an Alexandrov topology are also known as Alexandrov-discrete spaces or finitely generated spaces. The latter name stems from the fact that their topology is uniquely determined by the family of all finite subspaces. This makes them a generalization of finite topological spaces.
Alexandrov-discrete spaces are named after the Russian topologist Pavel Alexandrov. They should not be confused with Alexandrov spaces from Riemannian geometry introduced by the Russian mathematician Aleksandr Danilovich Aleksandrov.


Algebraic topology

Algebraic topology is a branch of mathematics that uses tools from abstract algebra to study topological spaces. The basic goal is to find algebraic invariants that classify topological spaces up to homeomorphism, though usually most classify up to homotopy equivalence.
Although algebraic topology primarily uses algebra to study topological problems, using topology to solve algebraic problems is sometimes also possible. Algebraic topology, for example, allows for a convenient proof that any subgroup of a free group is again a free group.


Arithmetic topology

Arithmetic topology is an area of mathematics that is a combination of algebraic number theory and topology. It establishes an analogy between number fields and closed, orientable 3-manifolds.


Circuit topology (electrical)

The circuit topology of an electronic circuit is the form taken by the network of interconnections of the circuit components.  Different specific values or ratings of the components are regarded as being the same topology.  Topology is not concerned with the physical layout of components in a circuit, nor with their positions on a circuit diagram; similarly to the mathematical concept of topology, it is only concerned with what connections exist between the components.  Numerous physical layouts and circuit diagrams may all amount to the same topology.
Strictly speaking, replacing a component with one of an entirely different type is still the same topology.  In some contexts, however, these can loosely be described as different topologies.  For instance, interchanging inductors and capacitors in a low-pass filter results in a high-pass filter.  These might be described as high-pass and low-pass topologies even though the network topology is identical.  A more correct term for these classes of object (that is, a network where the type of component is specified but not the absolute value) is prototype network.
Electronic network topology is related to mathematical topology. In particular, for networks which contain only two-terminal devices, circuit topology can be viewed as an application of graph theory.  In a network analysis of such a circuit from a topological point of view, the network nodes are the vertices of graph theory, and the network branches are the edges of graph theory.
Standard graph theory can be extended to deal with active components and multi-terminal devices such as integrated circuits.  Graphs can also be used in the analysis of infinite networks.


Coarse topology

In mathematics, coarse topology is a term in comparison of topologies which specifies the partial order relation of a topological structure to other one(s).
Specifically, the coarsest topology may refer to:

Initial topology, the most coarse topology in a certain category of topologies
Trivial topology, the most coarse topology possible on a given set


Combinatorial topology

In mathematics, combinatorial topology was an older name for algebraic topology, dating from the time when topological invariants of spaces (for example the Betti numbers) were regarded as derived from combinatorial decompositions of spaces, such as decomposition into simplicial complexes. After the proof of the simplicial approximation theorem this approach provided rigour.
The change of name reflected the move to organise topological classes such as cycles-modulo-boundaries explicitly into abelian groups. This point of view is often attributed to Emmy Noether, and so the change of title may reflect her influence. The transition is also attributed to the work of Heinz Hopf, who was influenced by Noether, and to Leopold Vietoris and Walther Mayer, who independently defined homology.
A fairly precise date can be supplied in the internal notes of the Bourbaki group. While this kind of topology was still "combinatorial" in 1942, it had become "algebraic" by 1944. This corresponds also to the period where homological algebra and category theory were introduced for the study of topological spaces, and largely supplanted combinatorial methods.
More recently the term combinatorial topology has been revived for investigations carried out by treating topological objects as composed of pieces as in the older combinatorial topology, which is again found useful.
Azriel Rosenfeld (1973) proposed digital topology for a type of image processing that can be considered as a new development of combinatorial topology. The digital forms of the Euler characteristic theorem and the Gauss–Bonnet theorem were obtained by Li Chen and Yongwu Rong. A 2D grid cell topology already appeared in the Alexandrov–Hopf book Topologie I (1935).
Gottfried Wilhelm Leibniz had envisioned a form of combinatorial topology as early as 1679 in his work Characteristica Geometrica.


Comparison of topologies

In topology and related areas of mathematics, the set of all possible topologies on a given set forms a partially ordered set. This order relation can be used for comparison of the topologies.


Computable topology

Computable topology is a discipline in mathematics that studies the topological and algebraic structure of computation. Computable topology is not to be confused with algorithmic or computational topology, which studies the application of computation to topology.


Continuous function

In mathematics, a continuous function is a function such that a small variation of its argument induces at most a small variation of its value. This implies there are no abrupt changes in value, known as discontinuities. More precisely, a function is continuous if arbitrarily small changes in its value can be assured by restricting its argument to sufficiently small changes. A discontinuous function is a function that is not continuous. Until the 19th century, mathematicians largely relied on intuitive notions of continuity and considered only continuous functions. The epsilon–delta definition of a limit was introduced to formalize the definition of continuity.
Continuity is one of the core concepts of calculus and mathematical analysis, where arguments and values of functions are real numbers and complex numbers. The concept has been generalized to functions between metric spaces and between topological spaces. The latter are the most general continuous functions, and their definition is the basis of topology.
A stronger form of continuity is uniform continuity. In order theory, especially in domain theory, a related concept of continuity is Scott continuity.
As a practical example, the function H(t) denoting the height of a growing flower at time t would be considered continuous. In contrast, the function M(t) denoting the amount of money in a bank account at time t would be considered discontinuous since it "jumps" at each point in time when money is deposited or withdrawn.

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Cover (topology)

In mathematics, and more particularly in set theory, a cover (or covering) of a set

        X

    {\displaystyle X}

 is a family of subsets of

        X

    {\displaystyle X}

 whose union is all of

        X

    {\displaystyle X}

. More formally, if

        C
        =
        {

          U

            α

        :
        α
        ∈
        A
        }

    {\displaystyle C=\lbrace U_{\alpha }:\alpha \in A\rbrace }

 is an indexed family of subsets

          U

            α

        ⊂
        X

    {\displaystyle U_{\alpha }\subset X}

 (indexed by the set

        A

    {\displaystyle A}

), then

        C

    {\displaystyle C}

 is a cover of

        X

    {\displaystyle X}

 if

          ⋃

            α
            ∈
            A

          U

            α

        =
        X
        .

    {\displaystyle \bigcup _{\alpha \in A}U_{\alpha }=X.}

Thus the collection

        {

          U

            α

        :
        α
        ∈
        A
        }

    {\displaystyle \lbrace U_{\alpha }:\alpha \in A\rbrace }

 is a cover of

        X

    {\displaystyle X}

 if each element of

        X

    {\displaystyle X}

 belongs to at least one of the subsets

          U

            α

    {\displaystyle U_{\alpha }}

.


Differential topology

In mathematics, differential topology is the field dealing with the topological properties and smooth properties of smooth manifolds. In this sense differential topology is distinct from the closely related field of differential geometry, which concerns the geometric properties of smooth manifolds, including notions of size, distance, and rigid shape. By comparison differential topology is concerned with coarser properties, such as the number of holes in a manifold, its homotopy type, or the structure of its diffeomorphism group. Because many of these coarser properties may be captured algebraically, differential topology has strong links to algebraic topology.

The central goal of the field of differential topology is the classification of all smooth manifolds up to diffeomorphism. Since dimension is an invariant of smooth manifolds up to diffeomorphism type, this classification is often studied by classifying the (connected) manifolds in each dimension separately:

In dimension 1, the only smooth manifolds up to diffeomorphism are the circle, the real number line, and allowing a boundary, the half-closed interval

        [
        0
        ,
        1
        )

    {\displaystyle [0,1)}

 and fully closed interval

        [
        0
        ,
        1
        ]

    {\displaystyle [0,1]}

.
In dimension 2, every closed surface is classified up to diffeomorphism by its genus, the number of holes (or equivalently its Euler characteristic), and whether or not it is orientable. This is the famous classification of closed surfaces. Already in dimension two the classification of non-compact surfaces becomes difficult, due to the existence of exotic spaces such as Jacob's ladder.
In dimension 3, William Thurston's geometrization conjecture, proven by Grigori Perelman, gives a partial classification of compact three-manifolds. Included in this theorem is the Poincaré conjecture, which states that any closed, simply connected three-manifold is homeomorphic (and in fact diffeomorphic) to the 3-sphere.

Beginning in dimension 4, the classification becomes much more difficult for two reasons. Firstly, every finitely presented group appears as the fundamental group of some 4-manifold, and since the fundamental group is a diffeomorphism invariant, this makes the classification of 4-manifolds at least as difficult as the classification of finitely presented groups. By the word problem for groups, which is equivalent to the halting problem, it is impossible to classify such groups, so a full topological classification is impossible. Secondly, beginning in dimension four it is possible to have smooth manifolds that are homeomorphic, but with distinct, non-diffeomorphic smooth structures. This is true even for the Euclidean space

            R

            4

    {\displaystyle \mathbb {R} ^{4}}

, which admits many exotic

            R

            4

    {\displaystyle \mathbb {R} ^{4}}

 structures. This means that the study of differential topology in dimensions 4 and higher must use tools genuinely outside the realm of the regular continuous topology of topological manifolds. One of the central open problems in differential topology is the four-dimensional smooth Poincaré conjecture, which asks if every smooth 4-manifold that is homeomorphic to the 4-sphere, is also diffeomorphic to it. That is, does the 4-sphere admit only one smooth structure? This conjecture is true in dimensions 1, 2, and 3, by the above classification results, but is known to be false in dimension 7 due to the Milnor spheres.
Important tools in studying the differential topology of smooth manifolds include the construction of smooth topological invariants of such manifolds, such as de Rham cohomology or the intersection form, as well as smoothable topological constructions, such as smooth surgery theory or the construction of cobordisms. Morse theory is an important tool which studies smooth manifolds by considering the critical points of differentiable functions on the manifold, demonstrating how the smooth structure of the manifold enters into the set of tools available. Oftentimes more geometric or analytical techniques may be used, by equipping a smooth manifold with a Riemannian metric or by studying a differential equation on it. Care must be taken to ensure that the resulting information is insensitive to this choice of extra structure, and so genuinely reflects only the topological properties of the underlying smooth manifold. For example, the Hodge theorem provides a geometric and analytical interpretation of the de Rham cohomology, and gauge theory was used by Simon Donaldson to prove facts about the intersection form of simply connected 4-manifolds. In some cases techniques from contemporary physics may appear, such as topological quantum field theory, which can be used to compute topological invariants of smooth spaces.
Famous theorems in differential topology include the Whitney embedding theorem, the hairy ball theorem, the Hopf theorem, the Poincaré–Hopf theorem, Donaldson's theorem, and the Poincaré conjecture.

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Double origin topology

In mathematics, more specifically general topology, the double origin topology is an example of a topology given to the plane R2 with an extra point, say 0*, added. In this case, the double origin topology gives a topology on the set X = R2 ⊔ {0*}, where ⊔ denotes the disjoint union.


Dual topology

In functional analysis and related areas of mathematics a dual topology is a locally convex topology on a vector space that is induced by the continuous dual of the vector space, by means of the bilinear form (also called pairing) associated with the dual pair.
The different dual topologies for a given dual pair are characterized by the Mackey–Arens theorem. All locally convex topologies with their continuous dual are trivially a dual pair and the locally convex topology is a dual topology.
Several topological properties depend only on the dual pair and not on the chosen dual topology and thus it is often possible to substitute a complicated dual topology by a simpler one.


Electronic filter topology

Electronic filter topology defines electronic filter circuits without taking note of the values of the components used but only the manner in which those components are connected.
Filter design characterises filter circuits primarily by their transfer function rather than their topology. Transfer functions may be linear or nonlinear. Common types of linear filter transfer function are; high-pass, low-pass, bandpass, band-reject or notch and all-pass. Once the transfer function for a filter is chosen, the particular topology to implement such a prototype filter can be selected so that, for example, one might choose to design a Butterworth filter using the Sallen–Key topology.
Filter topologies may be divided into passive and active types. Passive topologies are composed exclusively of passive components: resistors, capacitors, and inductors.   Active topologies also include active components (such as transistors, op amps, and other integrated circuits) that require power. Further, topologies may be implemented either in unbalanced form or else in balanced form when employed in balanced circuits. Implementations such as electronic mixers and stereo sound may require arrays of identical circuits.


Euclidean topology

In mathematics, and especially general topology, the Euclidean topology is the natural topology induced on

        n

    {\displaystyle n}

-dimensional Euclidean space

            R

            n

    {\displaystyle \mathbb {R} ^{n}}

 by the Euclidean metric.


Filters in topology

In mathematics, a filter on a set is a collection of nonempty subsets which is upward closed and closed under finite intersections (see Filter on a set for a more detailed discussion).
An example of filter is the collection of neighborhoods of a point in a topological space.
This article is focused on applications of filters to topology.
Filters were introduced by Henri Cartan in 1937 as an alternative to the related notion of a net developed in 1922 by E. H. Moore and Herman L. Smith.
In metric spaces, and more generally in sequential spaces, basic topological notions such as open set, closed set, convergence, continuity, compactness and more can be fully characterized in terms of sequences, as studied in real analysis. But in other classes of spaces, sequences are insufficient.
Filters and nets both provide ways to generalize the notion of convergence and characterize all these topological notions in general topological spaces.  Filters also provide a common framework for defining various types of limits of functions, including limits from the left or right, to infinity, to a point or a set.
In particular, filters and nets provide equivalent notions of convergence: to each net one can associate a filter, and to each filter a net, so that the net converges to a point if and only if the same is true of the associated filter, and vice versa. So the use of one or the other is often a matter of convenience.
Besides characterizing topological notions, filters and ultrafilters, which are a special type of filter, are used extensively in general topology for constructing topological spaces of interest.


Final topology

In general topology and related areas of mathematics, the final topology (or coinduced, strong, colimit, or inductive topology) on a set

        X
        ,

    {\displaystyle X,}

 with respect to a family of functions from topological spaces into

        X
        ,

    {\displaystyle X,}

 is the finest topology on

        X

    {\displaystyle X}

 that makes all those functions continuous.
The quotient topology on a quotient space is a final topology, with respect to a single surjective function, namely the quotient map. The disjoint union topology is the final topology with respect to the inclusion maps. The final topology is also the topology that every direct limit in the category of topological spaces is endowed with, and it is in the context of direct limits that the final topology often appears.  A topology is coherent with some collection of subspaces if and only if it is the final topology induced by the natural inclusions.
The dual notion is the initial topology, which for a given family of functions from a set

        X

    {\displaystyle X}

 into topological spaces is the coarsest topology on

        X

    {\displaystyle X}

 that makes those functions continuous.


Finite topology

Finite topology is a mathematical concept which has several different meanings.


Flat topology

In mathematics, the flat topology is a Grothendieck topology used in algebraic geometry. It is used to define the theory of flat cohomology; it also plays a fundamental role in the theory of descent (faithfully flat descent). The term flat here comes from flat modules.
There are several slightly different flat topologies, the most common of which are the fppf topology and the fpqc topology.  fppf stands for fidèlement plate de présentation finie, and in this topology, a morphism of affine schemes is a covering morphism if it is faithfully flat and of finite presentation.  fpqc stands for fidèlement plate et quasi-compacte, and in this topology, a morphism of affine schemes is a covering morphism if it is faithfully flat and a quasi-compact morphism.  In both categories, a covering family is defined to be a family which is a cover on Zariski open subsets.  In the fpqc topology, any faithfully flat and quasi-compact morphism is a cover.  These topologies are closely related to descent. The "pure" faithfully flat topology without any further finiteness conditions such as quasi compactness or finite presentation is not used much as it is not subcanonical; in other words, representable functors need not be sheaves.
Unfortunately the terminology for flat topologies is not standardized. Some authors use the term "topology" for a pretopology, and there are several slightly different pretopologies sometimes called the fppf or fpqc (pre)topology, which sometimes give the same topology.
Flat cohomology was introduced by Grothendieck in about 1960.


General topology

In mathematics, general topology (or point set topology) is the branch of topology that deals with the basic set-theoretic definitions and constructions used in topology. It is the foundation of most other branches of topology, including differential topology, geometric topology, and algebraic topology.
The fundamental concepts in point-set topology are continuity, compactness, and connectedness:

Continuous functions, intuitively, take nearby points to nearby points.
Compact sets are those that can be covered by finitely many sets of arbitrarily small size.
Connected sets are sets that cannot be divided into two pieces that are far apart.
The terms 'nearby', 'arbitrarily small', and 'far apart' can all be made precise by using the concept of open sets. If we change the definition of 'open set', we change what continuous functions, compact sets, and connected sets are. Each choice of definition for 'open set' is called a topology. A set with a topology is called a topological space.
Metric spaces are an important class of topological spaces where a real, non-negative distance, also called a metric, can be defined on pairs of points in the set. Having a metric simplifies many proofs, and many of the most common topological spaces are metric spaces.


Graph (topology)


Grothendieck topology

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1883 eruption of Krakatoa

Between 19 May and 21 October 1883, the volcanic island of Krakatoa (located in the Sunda Strait, then part of the Dutch East Indies—modern-day Indonesia) began erupting, lasting more than five months. On 27 August, the island had its most significant eruption, which destroyed over 70% of the island and its surrounding archipelago, the island collapsing into a caldera. The eruption of 27 August had an estimated volcanic explosivity index of 6, and is one of the deadliest and most destructive volcanic events in recorded history; the third explosion of that day, that occurred at 10:02 a.m., remains the loudest-known sound in history.
The explosion was heard 3,110 kilometres (1,930 mi) away in Perth, Western Australia, and Rodrigues near Mauritius, 4,800 kilometres (3,000 mi) away. The acoustic pressure wave circled the globe more than three times. At least 36,417 deaths are attributed to the eruption and the tsunamis it created. Significant additional effects were felt worldwide in the days and weeks after the volcano's eruption. Additional seismic activity was reported until February 1884, but any reports after October 1883 were dismissed by Rogier Verbeek's subsequent investigation into the eruption.


Ambrym

Ambrym is a volcanic island in Malampa Province in the archipelago of Vanuatu. It is located near the center of the archipelago of Vanuatu, and also hosts one of the most active volcanoes in the world, which includes lava lakes in two craters near the summit. It is currently the least populous island in the country.


Apoyeque

Apoyeque is a pyroclastic shield, located in the Chiltepe Peninsula Natural Reserve in Nicaragua. It has a 2.8-km wide, 400-m-deep, lake-filled caldera.


Bruce Houghton

Bruce F. Houghton (born 29 April 1950 in Auckland, New Zealand) is a New Zealand volcanologist. He was a student at Auckland University, and University of Otago, where he completed a PhD in 1977 on the geology of the Takatimu Mountains in western Southland.
As of 2010, Houghton was the Hawai'i State volcanologist and the Gordon A. Macdonald Professor of Volcanology at the University of Hawaiʻi. In August 2017, Bruce was awarded the highest award in volcanology, the International Association of Volcanology and Chemistry of the Earth's Interior's Thorarinsson Medal. He is recognized as "a giant of volcanology".


Bulletin of Volcanology

The Bulletin of Volcanology is a peer reviewed scientific journal that is published ten times per year by  Springer Science+Business Media. It is the official journal of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI). The focus of the journal is volcanoes, volcanic products, eruptive behavior, and volcanic hazards. The Executive Editor is Marie Edmonds.
The impact factor for Bulletin of Volcanology in 2020 is 2.517.


Clive Oppenheimer

Clive Oppenheimer (born 1964) is a British volcanologist, and Professor of Volcanology in the Department of Geography of the University of Cambridge.


Costanza Bonadonna

Costanza Bonadonna (born 1971) is an Italian earth scientist who is a Full Professor of volcanology and geological risk at the University of Geneva. She currently serves as Dean of the Faculty of Science at the University of Geneva, President of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI), and past President of the Volcanology, Geochemistry, and Petrology (VGP) section of the American Geophysical Union (AGU).


Decade Volcanoes

The Decade Volcanoes are 16 volcanoes identified by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) as being worthy of particular study in light of their history of large, destructive eruptions and proximity to densely populated areas.  The Decade Volcanoes project encourages studies and public-awareness activities at these volcanoes, with the aim of achieving a better understanding of the volcanoes and the dangers they present, and thus being able to reduce the severity of natural disasters.
Decade Volcanoes are named as such because the project was initiated in the 1990s as part of the United Nations–sponsored International Decade for Natural Disaster Reduction.
A volcano may be designated a Decade Volcano if it exhibits more than one volcanic hazard (people living near the Decade Volcanoes may experience tephra fall, pyroclastic flows, lava flows, lahars, volcanic edifice instability and lava dome collapse); shows recent geological activity; is located in a densely populated area (eruptions at any of the Decade Volcanoes may threaten tens or hundreds of thousands of people, and therefore mitigating eruption hazards at these volcanoes is crucial); is politically and physically accessible for study; and there is local support for the work.


Deformation (volcanology)

In volcanology, deformation refers to the change in the shape of a volcano or the surrounding landscape due to the movement of magma. This can be in the form of inflation, which is a response to pressurization, or deflation, which is a response to depressurization. Inflation is represented by swelling of the ground surface, a volcanic edifice, or a subsurface magma body. It can be caused by magma accumulation, exsolution of volatiles, geothermal processes, heating, and tectonic compression. Deflation is represented by shrinking of the ground surface, a volcanic edifice, or a subsurface magma body. It can be caused by magma withdrawal (related to intrusion or eruption), volatile escape, thermal contraction, phase changes during crystallization, and tectonic extension. Deformation is a key indicator of pre-eruptive unrest at many active volcanoes, but deformation signals must be used in combination with other eruption indicators for forecasting reliability.


Ejecta

Ejecta (Latin for 'things thrown out'; sing. ejectum) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic materials (tephra) that came out of a volcanic explosion and magma eruption volcanic vent, or crater, has traveled through the air or water, and fell back to the ground surface or ocean floor.


Eruption of Mount Vesuvius in 79 AD

In 79 AD, Mount Vesuvius, a stratovolcano located in the modern-day region of Campania, Italy, erupted, causing one of the deadliest eruptions in history. Vesuvius violently ejected a cloud of super-heated tephra and gases to a height of 33 km (21 mi), ejecting molten rock, pulverized pumice and hot ash at 1.5 million tons per second, ultimately releasing 100,000 times the thermal energy of the atomic bombings of Hiroshima and Nagasaki. The event gives its name to the Vesuvian type of volcanic eruption, characterised by columns of hot gases and ash reaching the stratosphere, although the event also included pyroclastic flows associated with Peléan eruptions.
The event destroyed several Roman towns and settlements in the area. Pompeii and Herculaneum, obliterated and buried underneath massive pyroclastic surges and ashfall deposits, are the most famous examples. Archaeological excavations have revealed much of the towns and the lives of the inhabitants, leading to the area becoming Vesuvius National Park and a UNESCO World Heritage Site.
The total population of both cities was over 20,000. The remains of over 1,500 people have been found at Pompeii and Herculaneum. The total death toll from the eruption remains unknown.
A detailed firsthand account of the eruption is preserved in two letters of Pliny the Younger, who personally witnessed the event from the town of Misenum.


Flat Landing Brook Formation

The Flat Landing Brook Formation is a geological formation in
Gloucester County of northern New Brunswick, Canada. It consists mostly of volcanic rocks that were deposited 466 to 465 million years ago during the Darriwilian stage of the Middle Ordovician epoch.


George P. L. Walker

George Patrick Leonard Walker  (2 March 1926 – 17 January 2005) was a British geologist who began his career studying mineralogy and later made significant contributions to volcanology.
He was widely regarded as one of the pioneers of modern quantitative volcanology.


Hawaii Center for Volcanology

The Hawaii Center for Volcanology was a cooperative effort between the School of Ocean and Earth Science and Technology at the University of Hawaiʻi at Mānoa, the Hawaiian Volcano Observatory of the United States Geological Survey, and the Center for the Study of Active Volcanoes at the University of Hawaii at Hilo. The loosely organized cooperative was created in 1992 to "bring together experts from around the state of Hawaii so that we might better understand these magical mountains of fire", and consists of approximately 80 scientists. Its site is maintained by members of the School of Ocean and Earth Science and Technology staff, even though it is no longer in operation.


The International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) is a learned society that focuses on research in volcanology, efforts to mitigate volcanic disasters, and research into closely related disciplines, such as igneous geochemistry and petrology, geochronology, volcanogenic mineral deposits, and the physics of the generation and ascent of magmas in the upper mantle and crust. It is one of eight constituent associations of the International Union of Geodesy and Geophysics (IUGG).
IAVCEI is run by an executive committee whose membership changes every four years. The Executive determines policies for the Association, enacting them through a series of commissions and task groups. Bulletin of Volcanology is the journal of IAVCEI.


Journal of Volcanology and Geothermal Research is a scientific journal that publishes recent research on the fields of volcanology and geothermal activity, as well as the societal and environmental impact of these phenomenon.


Lionel Wilson (geophysicist)

Lionel Wilson is a British volcanologist, known for his studies of the physics of volcanic eruptions, and for his work on planetary volcanism. He was awarded the G.K. Gilbert Award of the Geological Society of America in 2005, and the Thorarinsson Medal of the International Association of Volcanology and Chemistry of the Earth's Interior in 2025.


List of active volcanoes in the Philippines

As of 2018, the Philippines has 24 volcanoes listed as active by the Philippine Institute of Volcanology and Seismology (PHIVOLCS). Twenty-one of these have had historical eruptions. The three exceptions are Cabalian, which is a strongly fumarolic volcano; Leonard Kniaseff, which was active 1,800 years ago (C14), and Isarog, which last erupted around 3500 BCE and 2374 BCE ± 87 based on radiocarbon dating.
Volcanoes in the country have erupted within the last 600 years, with accounts of these eruptions documented by humans; or have erupted within the last 10,000 years (Holocene). There are 100 volcanoes in the Philippines listed by the Smithsonian Institution's Global Volcanism Program (GVP) at present, of which 20 are categorized as "historical" and 59 as "Holocene". The GVP lists volcanoes with historical, Holocene eruptions, or possibly older if strong signs of volcanism are still evident through thermal features like fumaroles, hot springs, mud pots, etc.


List of earthquakes in Italy

This is a list of earthquakes in Italy that had epicentres in Italy, or significantly affected the country. On average every four years an earthquake with a magnitude equal to or greater than 5.5 occurs in Italy.
Due to the particular geodynamic situation (convergence of the Eurasian plate with the African plate) the Italian territory is frequently subject to earthquakes, giving it the record in Europe for these phenomena. Out of 1,300 destructive earthquakes that occurred in the 2nd millennium in the central Mediterranean Sea, 500 affected Italy.
The analysis of the earthquakes indicates that they are mostly distributed along the areas affected by Alpine and Apennine tectonics, where they are caused by movements along faults. The highest seismicity hazard in Italy has been concentrated in the central-southern part of the peninsula, along the Apennine ridge, in Calabria and Sicily and in some northern areas, like Friuli-Venezia Giulia, part of Veneto and western Liguria.


List of large Holocene volcanic eruptions

This is a list of volcanoes that have had large explosive eruptions during the Holocene (since about 11,650 years Before Present), with a volcanic explosivity index (VEI) of 5 or higher, or a plume height of at least 30 km. To date, there have been no eruptions with a confirmed VEI of 8 in the Holocene; and only a few VEI-7 eruptions are thought to have occurred during this time: the most recent was the 1815 eruption of Mount Tambora.


List of mountains in the Philippines


List of potentially active volcanoes in the Philippines


Mamelon (volcanology)


Mayon


Mount Tambora


Mount Vesuvius

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-maxxing

-maxxing (also -maxxed, -maxxer) is an Internet slang suffix meaning to optimize or maximize a particular quality or activity. The double consonantized variation "xx" suffix originated from the incelosphere in the 2010s, where looksmaxxing referred to maximizing one's physical attractiveness, whereas the single consonantized variation "x" originated in game theory and role-playing game terminology. It entered mainstream usage through TikTok and social media in the 2020s, often applied humorously to everyday activities.


Abstract strategy game

Abstract strategy games are games like chess, draughts and Go. They are typically strategy games with minimal or no narrative theme, an outcome determined mostly by player choice (with minimal or no randomness; deterministic), and in which there is little to no hidden information (also called perfect information games). Pure abstract strategy games are typically governed by simple, explicit rules whose strategic depth arises from combinatorial complexity. Abstract strategy games are also games of analytical skill, usually with significant depth or strategic complexity. Skill grows over time as players develop experience, and a greater understanding of a specific game. Experienced players with greater ability to analyze multiple moves in advance will almost always beat beginners at abstract strategy games.
There are numerous types of abstract strategy games, from pure strategy to mixed strategy games that may have elements of random or hidden information. Go, Pente and checkers are "pure" abstract perfect information games since they perfectly fulfill all three criteria; Chess games, Tafl games and Hive feature recognizable themes (though they are highly stylized or minimalistic); Stratego is a borderline or exception case, since it is deterministic, loosely based on Napoleonic warfare, and features some concealed information. Furthermore, some games with elements of chance, like backgammon and pachisi, may also be considered abstract strategy games, though there is disagreement on this issue among ludologists. However, since they contain an element of luck and randomness, they are not "pure" abstract strategy games.
Several traditional abstract strategy games like Chess and Go have a long history and are culturally significant products that have been played for generations in various regions of the world. Beyond entertainment, abstract strategy games have served as educational tools to teach logic, patience and foresight. They have also served as status symbols for the intelligentsia and elite classes, and as competitive mind sports. For example, during the Cold War, chess matches were seen as intellectual battles between East and West.


Algorithmic game theory

Algorithmic game theory (AGT) is an interdisciplinary field at the intersection of game theory and computer science, focused on understanding and designing algorithms for environments where multiple strategic agents interact. This research area combines computational thinking with economic principles to address challenges that emerge when algorithmic inputs come from self-interested participants.
In traditional algorithm design, inputs are assumed to be fixed and reliable. However, in many real-world applications—such as online auctions, internet routing, digital advertising, and resource allocation systems—inputs are provided by multiple independent agents who may strategically misreport information to manipulate outcomes in their favor. AGT provides frameworks to analyze and design systems that remain effective despite such strategic behavior.
The field can be approached from two complementary perspectives:

Analysis: Evaluating existing algorithms and systems through game-theoretic tools to understand their strategic properties. This includes calculating and proving properties of Nash equilibria (stable states where no participant can benefit by changing only their own strategy), measuring price of anarchy (efficiency loss due to selfish behavior), and analyzing best-response dynamics (how systems evolve when players sequentially optimize their strategies).
Design: Creating mechanisms and algorithms with both desirable computational properties and game-theoretic robustness. This sub-field, known as algorithmic mechanism design, develops systems that incentivize truthful behavior while maintaining computational efficiency.
Algorithm designers in this domain must satisfy traditional algorithmic requirements (such as polynomial-time running time and good approximation ratio) while simultaneously addressing incentive constraints that ensure participants act according to the system's intended design.


Battle of the sexes (game theory)

In game theory, the battle of the sexes is a two-player coordination game that also involves elements of conflict. The game was introduced in 1957 by R. Duncan Luce and Howard Raiffa in their book, Games and Decisions. Some authors prefer to avoid assigning sexes to the players and instead use Players 1 and 2, and some refer to the game as Bach or Stravinsky, using two concerts as the two events. The game description here follows Luce and Raiffa's original story.
Imagine that a man and a woman hope to meet this evening, but have a choice between two events to attend: a prize fight and a ballet. The man would prefer to go to prize fight. The woman would prefer the ballet. Both would prefer to go to the same event rather than different ones. If they cannot communicate, where should they go?
The payoff matrix labeled "Battle of the Sexes (1)" shows the payoffs when the man chooses a row and the woman chooses a column. In each cell, the first number represents the man's payoff and the second number the woman's.
This standard representation does not account for the additional harm that might come from not only going to different locations, but going to the wrong one as well (e.g. the man goes to the ballet while the woman goes to the prize fight, satisfying neither). To account for this, the game would be represented in "Battle of the Sexes  (2)", where in the top right box, the players each have a payoff of 1 because they at least get to attend their favored events.


Behavioral game theory

Behavioral game theory seeks to examine how people's strategic decision-making behavior is shaped by social preferences, social utility and other psychological factors. Behavioral game theory analyzes interactive strategic decisions and behavior using the methods of game theory, experimental economics, and experimental psychology. Experiments include testing deviations from typical simplifications of economic theory such as the independence axiom and neglect of altruism, fairness, and framing effects. As a research program, the subject is a development of the last three decades.
Traditional game theory is a critical principle of economic theory, and assumes that people's strategic decisions are shaped by rationality, selfishness and utility maximisation. It focuses on the mathematical structure of equilibria, and tends to use basic rational choice theory and utility maximization as the primary principles within economic models. At the same time rational choice theory is an ideal model that assumes that individuals will actively choose the option with the greatest benefit. The fact is that consumers have different preferences and rational choice theory is not accurate in its assumptions about consumer behavior. In contrast to traditional game theory, behavioral game theory examines how actual human behavior tends to deviate from standard predictions and models. In order to more accurately understand these deviations and determine the factors and conditions involved in strategic decision making, behavioral game theory aims to create new models that incorporate psychological principles. Studies of behavioral game theory demonstrate that choices are not always rational and do not always represent the utility maximizing choice.
Behavioral game theory largely utilizes empirical and theoretical research to understand human behavior. It also uses laboratory and field experiments, as well as modeling – both theoretical and computational. Recently, methods from machine learning have been applied in work at the intersection of economics, psychology, and computer science to improve both prediction and understanding of behavior in games.


Chicken (game)

The game of chicken, also known as the hawk-dove game or snowdrift game, is a model of conflict for two players in game theory. The principle of the game is that while the ideal outcome is for one player to yield (to avoid the worst outcome if neither yields), individuals try to avoid it out of pride, not wanting to look like "chickens". The players may taunt each other to increase the shame of yielding. When one player yields the conflict is avoided and the game ends.
The name "chicken" has its origins in a game in which two drivers drive toward each other on a collision course: one must swerve, or both may die in the crash, but if one driver swerves and the other does not, the one who swerved will be called a "chicken", meaning a coward; this terminology is most prevalent in political science and economics. The name "hawk–dove" refers to a situation in which there is a competition for a shared resource and the contestants can choose either conciliation or conflict; this terminology is most commonly used in biology and evolutionary game theory. From a game-theoretic point of view, "chicken" and "hawk–dove" are identical. The game has also been used to describe the mutual assured destruction of nuclear warfare, especially the sort of brinkmanship involved in the Cuban Missile Crisis.


Combinatorial game theory

Combinatorial game theory is a branch of mathematics and theoretical computer science that typically studies sequential games with perfect information. Research in this field has primarily focused on two-player games in which a position evolves through alternating moves, each governed by well-defined rules, with the aim of achieving a specific winning condition. Unlike economic game theory, combinatorial game theory generally avoids the study of games of chance or games involving imperfect information, preferring instead games in which the current state and the full set of available moves are always known to both players. However, as mathematical techniques develop, the scope of analyzable games expands, and the boundaries of the field continue to evolve. Authors typically define the term "game" at the outset of academic papers, with definitions tailored to the specific game under analysis rather than reflecting the field’s full scope.
Combinatorial games include well-known examples such as chess, checkers, and Go, which are considered complex and non-trivial, as well as simpler, "solved" games like tic-tac-toe. Some combinatorial games, such as infinite chess, may feature an unbounded playing area. In the context of combinatorial game theory, the structure of such games is typically modeled using a game tree. The field also encompasses single-player puzzles like Sudoku, and zero-player automata such as Conway's Game of Life—although these are sometimes more accurately categorized as mathematical puzzles or automata, given that the strictest definitions of "game" imply the involvement of multiple participants.
A key concept in combinatorial game theory is that of the solved game. For instance, tic-tac-toe is solved in that optimal play by both participants always results in a draw. Determining such outcomes for more complex games is significantly more difficult. Notably, in 2007, checkers was announced to be weakly solved, with perfect play by both sides leading to a draw; however, this result required a computer-assisted proof. Many real-world games remain too complex for complete analysis, though combinatorial methods have shown some success in the study of Go endgames. In combinatorial game theory, analyzing a position means finding the best sequence of moves for both players until the game ends, but this becomes extremely difficult for anything more complex than simple games.
It is useful to distinguish between combinatorial "mathgames"—games of primary interest to mathematicians and scientists for theoretical exploration—and "playgames," which are more widely played for entertainment and competition. Some games, such as Nim, straddle both categories. Nim played a foundational role in the development of combinatorial game theory and was among the earliest games to be programmed on a computer. Tic-tac-toe continues to be used in teaching fundamental concepts of game AI design to computer science students.


Competition

Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, individuals, economic and social groups, etc. The rivalry can be over attainment of any exclusive goal, including recognition.
Competition occurs in nature, between living organisms which co-exist in the same environment. Animals compete over water supplies, food, mates, and other biological resources. Humans usually compete for food and mates, though when these needs are met deep rivalries often arise over the pursuit of wealth, power, prestige, and fame when in a static, repetitive, or unchanging environment. Competition is a major tenet of market economies and business, often associated with business competition as companies are in competition with at least one other firm over the same group of customers. Competition inside a company is usually stimulated with the larger purpose of meeting and reaching higher quality of services or improved products that the company may produce or develop.
Competition is often considered to be the opposite of cooperation; however, in the real world, mixtures of cooperation and competition are the norm. In economies, as the philosopher R. G. Collingwood argued "the presence of these two opposites together is essential to an economic system. The parties to an economic action co-operate in competing, like two chess players". Optimal strategies to achieve goals are studied in the branch of mathematics known as game theory.
Competition has been studied in several fields, including psychology, sociology and anthropology. Social psychologists, for instance, study the nature of competition. They investigate the natural urge of competition and its circumstances. They also study group dynamics, to detect how competition emerges and what its effects are. Sociologists, meanwhile, study the effects of competition on society as a whole. Additionally, anthropologists study the history and prehistory of competition in various cultures. They also investigate how competition manifested itself in various cultural settings in the past, and how competition has developed over time.


Conflict resolution

Conflict resolution is conceptualized as the methods and processes involved in facilitating the peaceful ending of conflict and retribution.
Committed group members attempt to resolve group conflicts by actively communicating information about their conflicting motives or ideologies to the rest of group (e.g., intentions; reasons for holding certain beliefs) and by engaging in collective negotiation. Dimensions of resolution typically parallel the dimensions of conflict in the way the conflict is processed.
Cognitive resolution is the way disputants understand and view the conflict, with beliefs, perspectives, understandings and attitudes. Emotional resolution is in the way disputants feel about a conflict, the emotional energy. Behavioral resolution is reflective of how the disputants act, their behavior. Ultimately a wide range of methods and procedures for addressing conflict exist, including negotiation, mediation, mediation-arbitration, diplomacy, and creative peacebuilding.


Cooperative game theory

In game theory, a cooperative or coalitional game is a game with groups of players who form binding "coalitions" with external enforcement of cooperative behavior (e.g. through contract law). This is different from non-cooperative games in which there is either no possibility to forge alliances or all agreements need to be self-enforcing (e.g. through credible threats).
Cooperative games are analysed by focusing on coalitions that can be formed, and the joint actions that groups can take and the resulting collective payoffs.


Core (game theory)

In cooperative game theory, the core  is the set of feasible allocations or imputations where no coalition of agents can benefit by breaking away from the grand coalition. One can think of the core corresponding to situations where it is possible to sustain cooperation among all agents. A coalition is said to improve upon or block a feasible allocation if the members of that coalition can generate more value among themselves than they are allocated in the original allocation. As such, that coalition is not incentivized to stay with the grand coalition.
An allocation is said to be in the core of a game if there is no coalition that can improve upon it. The core is then the set of all feasible allocations.


Daniel Kahneman

Daniel Kahneman (; Hebrew: דניאל כהנמן; March 5, 1934 – March 27, 2024) was an Israeli-American psychologist best known for his work on the psychology of judgment and decision-making as well as behavioral economics, for which he was awarded the 2002 Nobel Memorial Prize in Economic Sciences together with Vernon L. Smith. Kahneman's published empirical findings challenge the assumption of human rationality prevailing in modern economic theory. Kahneman became known as the "grandfather of behavioral economics."
With Amos Tversky and others, Kahneman established a cognitive basis for common human errors that arise from heuristics and biases, and developed prospect theory. In 2011, Kahneman was named by Foreign Policy magazine in its list of top global thinkers. In the same year, his book Thinking, Fast and Slow, which summarizes much of his research, was published and became a best seller. In 2015, The Economist listed him as the seventh most influential economist in the world.
Kahneman was professor emeritus of psychology and public affairs at Princeton University's Princeton School of Public and International Affairs. Kahneman was a founding partner of TGG Group, a business and philanthropy consulting company. He was married to cognitive psychologist and Royal Society Fellow Anne Treisman, who died in 2018.


Dark forest hypothesis

The dark forest hypothesis is the idea that extraterrestrial civilizations may exist in abundance across the universe, but remain silent and hidden out of fear that revealing themselves would lead to destruction by a more technologically advanced and hostile civilization. It is one of several proposed explanations of the Fermi paradox, which contrasts the apparently high probability of extraterrestrial life with the lack of evidence for it. The hypothesis derives its name from Liu Cixin's 2008 novel The Dark Forest although similar concepts predate the work.


Deadlock (game theory)

In game theory, Deadlock is a game where the action that is mutually most beneficial is also dominant. This provides a contrast to the Prisoner's Dilemma where the mutually most beneficial action is dominated.  This makes Deadlock of rather less interest, since there is no conflict between self-interest and mutual benefit.
On the other hand, deadlock game can also impact the economic behaviour and changes to equilibrium outcome in society.


Economics

Economics () is a social science that studies the production, distribution, and consumption of goods and services.
Economics focuses on the behaviour and interactions of economic agents and how economies work. Microeconomics analyses what is viewed as the basic elements of economies, including individual agents and markets, their interactions, and the outcomes of those interactions. Individual agents may include households, firms, buyers, and sellers. Macroeconomics analyses economies as systems where production, distribution, consumption, savings, and investment expenditure interact; and the factors of production affecting them, such as: labour, capital, land, and enterprise, inflation, economic growth, and public policies that impact these elements. It also seeks to analyse and describe the global economy.
Other broad distinctions within economics include those between positive economics, describing "what is", and normative economics, advocating "what ought to be"; between economic theory and applied economics; between rational and behavioural economics; and between mainstream economics and heterodox economics.
Economic analysis can be applied throughout society, including business, finance, cybersecurity, health care, engineering and government. It is also applied to such diverse subjects as crime, education, the family, feminism, law, philosophy, politics, religion, social institutions, war, science, and the environment.

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Evolutionary game theory

Evolutionary game theory (EGT) is the application of game theory to evolving populations in biology. It defines a framework of contests, strategies, and analytics into which Darwinian competition can be modelled. It originated in 1973 with John Maynard Smith and George R. Price's formalisation of contests, analysed as strategies, and the mathematical criteria that can be used to predict the results of competing strategies.
Evolutionary game theory differs from classical game theory in focusing more on the dynamics of strategy change. This is influenced by the frequency of the competing strategies in the population.
Evolutionary game theory has helped to explain the basis of altruistic behaviours in Darwinian evolution. It has in turn become of interest to economists, sociologists, anthropologists, and philosophers.
Moreover, given evolutionary game theory's ability to model the decision-making dynamics of interacting agents over time, evolutionary game theoretic models have found applications in a range of other fields including control engineering and traffic modeling.


Focal point (game theory)

In game theory, a focal point (or Schelling point) is a solution that people tend to choose by default in the absence of communication in order to avoid coordination failure. The concept was introduced by the American economist Thomas Schelling in his book The Strategy of Conflict (1960). Schelling states that "[p]eople can often concert their intentions or expectations with others if each knows that the other is trying to do the same" in a cooperative situation (p. 57), so their action would converge on a focal point which has some kind of prominence compared with the environment. However, the conspicuousness of the focal point depends on time, place and people themselves. It may not be a definite solution.


Folk theorem (game theory)

In game theory, folk theorems are a class of theorems describing an abundance of Nash equilibrium payoff profiles in repeated games (Friedman 1971). The original Folk Theorem concerned the payoffs of all the Nash equilibria of an infinitely repeated game. This result was called the Folk Theorem because it was widely known among game theorists in the 1950s, even though no one had published it. Friedman's (1971) Theorem concerns the payoffs of certain subgame-perfect Nash equilibria (SPE) of an infinitely repeated game, and so strengthens the original Folk Theorem by using a stronger equilibrium concept: subgame-perfect Nash equilibria rather than Nash equilibria.
The Folk Theorem suggests that if the players are patient enough and far-sighted (i.e. if the discount factor

        δ
        →
        1

    {\displaystyle \delta \to 1}

), then repeated interaction can result in virtually any average payoff in an SPE equilibrium. "Virtually any" is here technically defined as "feasible" and "individually rational".


Game

A game is an activity defined by a challenge and a set of rules, typically done for enjoyment, competition, or development. Games may be played informally or in professional competitive settings before audiences. Popular formats include board games, card games, video games, and sports, distinguished from unstructured play by having rules. Scholars have long debated the essence of games, with no single definition achieving universal acceptance.
Games are a universal feature of human culture. The Royal Game of Ur and Senet are among the oldest known games, dating back to at least 2600 BCE. Throughout history, games have served as tools for entertainment, teaching, ritual, and socialization. In the modern era, the global video game industry has grown to surpass both film and music in annual revenue, reflecting how central games have become to contemporary life.

Philosophically, games have attracted attention as a test case for the nature of rules and meaning. Psychologists link play to cognitive development in children and to the intense, satisfying concentration called flow in adults. Game theory uses the structure of games to model decision making in fields such as economics and evolutionary biology.