Cohn Ronald

High Quality Content by WIKIPEDIA articles! In mathematics, tetration (also known as hyper-4) is an iterated exponential and is the next hyper operator after exponentiation. The word tetration was coined by English mathematician Reuben Louis Goodstein from tetra- (four) and iteration. Tetration is used for the notation of very large numbers. Shown here are examples of the first four hyper operators, with tetration as the fourth (and succession, the unary operation denoted taking and yielding the number after , as the 0th):

High Quality Content by WIKIPEDIA articles! In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism. These signals tell a cell to do something—for example to divide or die, or to allow certain molecules to enter or exit the cell.

High Quality Content by WIKIPEDIA articles! Simple living encompasses a number of different voluntary practices to simplify one`s lifestyle. These may include reducing one`s possessions or increasing self-sufficiency, for example. Simple living may be characterized by individuals being satisfied with what they need rather than want. Although asceticism generally promotes living simply and refraining from luxury and indulgence, not all proponents of simple living are ascetics. Simple living is distinct from those living in forced poverty, as it is a voluntary lifestyle choice.

High Quality Content by WIKIPEDIA articles! According to the Fourth Five-Year Economic Development Plan (2005-2010), the Privatization Organization of Iran affiliated to the Ministry of Economic Affairs and Finance is in charge of setting prices and ceding shares to the general public and on the Tehran Stock Exchange. The privatization effort is primarily backed by reformist members of the Iranian government and society who hope that privatization can bring about economic and social change. Iranian president Mahmoud Ahmadinejad, a staunch conservative, has on several occasions lambasted the privatization policies and tried to counteract them.

High Quality Content by WIKIPEDIA articles! Paul Zachary "PZ" Myers (born March 9, 1957) is an American biology professor at the University of Minnesota Morris (UMM) and the author of the Pharyngula science blog. He is currently an associate professor of biology at UMM, works with zebrafish in the field of evolutionary developmental biology (evo-devo), and also cultivates an interest in cephalopods. He has published numerous research papers in Nature and other notable scientific journals.

High Quality Content by WIKIPEDIA articles! A rocket stove is an innovative clean and efficient cooking stove using small diameter wood fuel which is burned in simple high-temperature combustion chamber containing an insulated vertical chimney which ensures complete combustion prior to the flames reaching the cooking surface. The principles were described by Dr. Larry Winiarski from Aprovecho in 1982 and stoves based on this design won Ashden Awards in both 2005 and 2006. Interest in rocket stoves has led to the development of rocket mass heaters and other innovations.

High Quality Content by WIKIPEDIA articles! RealClimate is a commentary site (blog) on climatology. The site`s contributors are a group of climate scientists whose goal is to provide a quick response to developing stories and providing the context sometimes missing in mainstream commentary. The discussion is intended to be restricted to scientific topics and to avoid political or economic implications of the science. RealClimate was launched in December 2004 by nine climate scientists.

High Quality Content by WIKIPEDIA articles! A spliceosome is a complex of snRNA and protein subunits that removes introns from a transcribed pre-mRNA (hnRNA) segment. This process is generally referred to as splicing.

High Quality Content by WIKIPEDIA articles! Simple Authentication and Security Layer (SASL) is a framework for authentication and data security in Internet protocols. It decouples authentication mechanisms from application protocols, in theory allowing any authentication mechanism supported by SASL to be used in any application protocol that uses SASL. Authentication mechanisms can also support proxy authorization, a facility allowing one user to assume the identity of another. They can also provide a data security layer offering data integrity and data confidentiality services. DIGEST-MD5 provides an example of mechanisms which can provide a data-security layer. Application protocols that support SASL typically also support Transport...

High Quality Content by WIKIPEDIA articles! A robot certificate authority is a certificate authority (CA) which automatically signs public keys which match some requirement.

High Quality Content by WIKIPEDIA articles! Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring. It is isomeric with two other forms of diazine: Pyridazine, with the nitrogen atoms in positions 1 and 2; and Pyrazine, with the nitrogen atoms in positions 1 and 4.

High Quality Content by WIKIPEDIA articles! In economics, the private sector is that part of the economy, sometimes referred to as the citizen sector, which is run by private individuals or groups, usually as a means of enterprise for profit, and is not controlled by the state. By contrast, enterprises that are part of the state are part of the public sector; private, non-profit organizations are regarded as part of the voluntary sector.

High Quality Content by WIKIPEDIA articles! Real Club Deportivo Mallorca is a Spanish football team based on Palma, Majorca, in the Balearic Islands. Founded on 5 March 1916, the team currently plays in the Spanish first division, holding home games at Son Moix.

High Quality Content by WIKIPEDIA articles! Road signs in the United Kingdom conform broadly to European norms, though a number of signs are unique to Britain and direction signs omit European route numbers.

High Quality Content by WIKIPEDIA articles! Pye Records was a British record label. In its first incarnation, perhaps Pye`s best known artists were Lonnie Donegan (1956–69), Petula Clark (1957–71), The Searchers (1963–67), The Kinks (1964–71), Sandie Shaw (1964-1971) and Brotherhood of Man (1975–79). The label changed its name in 1980, but was briefly reactivated in 2006.

High Quality Content by WIKIPEDIA articles! A purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Purines, including substituted purines and their tautomers, are the most widely distributed kind of nitrogen-containing heterocycle in nature.

High Quality Content by WIKIPEDIA articles! An RNA virus is a virus that has RNA (ribonucleic acid) as its genetic material. This nucleic acid is usually single-stranded RNA (ssRNA) but may be double-stranded RNA (dsRNA). The ICTV classifies RNA viruses as those that belong to Group III, Group IV or Group V of the Baltimore classification system of classifying viruses, and does not consider viruses with DNA intermediates as RNA viruses. Notable human diseases caused by RNA viruses include SARS, influenza, hepatitis C and HIV.

High Quality Content by WIKIPEDIA articles! In cryptography, SIGSALY (also known as the X System, Project X, Ciphony I, and the Green Hornet) was a secure speech system used in World War II for the highest-level Allied communications.

High Quality Content by WIKIPEDIA articles! The RBU-6000 Smerch-2 (Реактивно-Бомбовая Установка, Reaktivno-Bombovaja Ustanovka; reaction engine-bomb installation Смерч; waterspout) is a 213 mm caliber Soviet anti-submarine rocket launcher. It is similar in principle to the Royal Navy Hedgehog system used during the Second World War. The system entered service in 1960-61 and is fitted to a wide range of Russian surface vessels. It consists of a horseshoe shaped arrangement of twelve launch barrels, that are remotely directed by the Burya fire control system (that can also control the shorter ranged RBU-1000). It fires RGB-60 unguided depth charges. The rockets are normally fired in salvos of 1, 2, 4, 8 or...

High Quality Content by WIKIPEDIA articles! In cryptography, an S-Box (Substitution-box) is a basic component of symmetric key algorithms which performs substitution. In block ciphers, they are typically used to obscure the relationship between the key and the ciphertext — Shannon`s property of confusion. In many cases, the S-Boxes are carefully chosen to resist cryptanalysis.

High Quality Content by WIKIPEDIA articles! Renewable heat is an application of renewable energy and it refers to the renewable generation of heat, rather than electrical power (e.g. replacing a fossil fuel boiler using concentrating solar thermal to feed radiators).

High Quality Content by WIKIPEDIA articles! In molecular biology and genetics, splicing is a modification of an RNA after transcription, in which introns are removed and exons are joined. This is needed for the typical eukaryotic messenger RNA before it can be used to produce a correct protein through translation. For many eukaryotic introns, splicing is done in a series of reactions which are catalyzed by the spliceosome, a complex of small nuclear ribonucleoproteins (snRNPs), but there are also self-splicing introns.

High Quality Content by WIKIPEDIA articles! A purchase order (PO) is a commercial document issued by a buyer to a seller, indicating types, quantities, and agreed prices for products or services the seller will provide to the buyer. Sending a purchase order to a supplier constitutes a legal offer to buy products or services. Acceptance of a purchase order by a seller usually forms a one-off contract between the buyer and seller, so no contract exists until the purchase order is accepted.