Evolution.

Genetic evidence from comparisons of multiple organisms showed that a glutathione-dependent formaldehyde dehydrogenase, identical to a class III alcohol dehydrogenase (ADH-3/ADH5), is presumed to be the ancestral enzyme for the entire ADH family. Early on in evolution, an effective method for eliminating both endogenous and exogenous formaldehyde was important and this capacity has conserved the ancestral ADH-3 through time. Gene duplication of ADH-3, followed by series of mutations, led to the evolution of other ADHs.  The ability to produce ethanol from sugar (which is the basis of how alcoholic beverages are made) is believed to have initially evolved in yeast. Though this feature is not adaptive from an energy point of view, by making alcohol in such high concentrations so that they would be toxic to other organisms, yeast cells could effectively eliminate their competition. Since rotting fruit can contain more than 4% of ethanol, animals eating the fruit needed a system to metabolize exogenous ethanol. This was thought to explain the conservation of ethanol active ADH in species other than yeast, though ADH-3 is now known to also have a major role in nitric oxide signaling.  In humans, sequencing of the ADH1B gene (responsible for production of an alcohol dehydrogenase polypeptide) shows several functional variants. In one, there is a SNP (single nucleotide polymorphism) that leads to either a Histidine or an Arginine residue at position 47 in the mature polypeptide. In the Histidine variant, the enzyme is much more effective at the aforementioned conversion. The enzyme responsible for the conversion of acetaldehyde to acetate, however, remains unaffected, which leads to differential rates of substrate catalysis and causes a buildup of toxic acetaldehyde, causing cell damage. This provides some protection against excessive alcohol consumption and alcohol dependence (alcoholism). Various haplotypes arising from this mutation are more concentrated in regions near Eastern China, a region also known for its low alcohol tolerance and dependence.  A study was conducted in order to find a correlation between allelic distribution and alcoholism, and the results suggest that the allelic distribution arose along with rice cultivation in the region between 12,000 and 6,000 years ago. In regions where rice was cultivated, rice was also fermented into ethanol. This led to speculation that increased alcohol availability led to alcoholism and abuse, resulting in lower reproductive fitness. Those with the variant allele have little tolerance for alcohol, thus lowering chance of dependence and abuse. The hypothesis posits that those individuals with the Histidine variant enzyme were sensitive enough to the effects of alcohol that differential reproductive success arose and the corresponding alleles were passed through the generations. Classical Darwinian evolution would act to select against the detrimental form of the enzyme (Arg variant) because of the lowered reproductive success of individuals carrying the allele. The result would be a higher frequency of the allele responsible for the His-variant enzyme in regions that had been under selective pressure the longest. The distribution and frequency of the His variant follows the spread of rice cultivation to inland regions of Asia, with higher frequencies of the His variant in regions that have cultivated rice the longest. The geographic distribution of the alleles seems to therefore be a result of natural selection against individuals with lower reproductive success, namely, those who carried the Arg variant allele and were more susceptible to alcoholism. However, the persistence of the Arg variant in other populations argues that the effect could not be strong.

Discovery.

The first-ever isolated alcohol dehydrogenase (ADH) was purified in 1937 from "Saccharomyces cerevisiae" (brewer's yeast). Many aspects of the catalytic mechanism for the horse liver ADH enzyme were investigated by Hugo Theorell and coworkers. ADH was also one of the first oligomeric enzymes that had its amino acid sequence and three-dimensional structure determined.  In early 1960, it was discovered in fruit flies of the genus "Drosophila".

Properties.

The alcohol dehydrogenases comprise a group of several isozymes that catalyse the oxidation of primary and secondary alcohols to aldehydes and ketones, respectively, and also can catalyse the reverse reaction. In mammals this is a redox (reduction/oxidation) reaction involving the coenzyme nicotinamide adenine dinucleotide (NAD).

Oxidation of alcohol.

Mechanism of action in humans.

Steps.

The mechanism in yeast and bacteria is the reverse of this reaction. These steps are supported through kinetic studies.

Involved subunits.

The substrate is coordinated to the zinc and this enzyme has two zinc atoms per subunit. One is the active site, which is involved in catalysis. In the active site, the ligands are Cys-46, Cys-174, His-67, and one water molecule. The other subunit is involved with structure. In this mechanism, the hydride from the alcohol goes to NAD. Crystal structures indicate that the His-51 deprotonates the nicotinamide ribose, which deprotonates Ser-48. Finally, Ser-48 deprotonates the alcohol, making it an aldehyde. From a mechanistic perspective, if the enzyme adds hydride to the re face of NAD, the resulting hydrogen is incorporated into the pro-R position. Enzymes that add hydride to the re face are deemed Class A dehydrogenases.

Active site.

The active site of human ADH1 (PDB:1HSO) consists of a zinc atom, His-67, Cys-174, Cys-46, Thr-48, His-51, Ile-269, Val-292, Ala-317, and Phe-319. In the commonly studied horse liver isoform, Thr-48 is a Ser, and Leu-319 is a Phe. The zinc coordinates the substrate (alcohol). The zinc is coordinated by Cys-46, Cys-174, and His-67. Leu-319, Ala-317, His-51, Ile-269 and Val-292 stabilize NAD by forming hydrogen bonds. His-51 and Ile-269 form hydrogen bonds with the alcohols on nicotinamide ribose. Phe-319, Ala-317 and Val-292 form hydrogen bonds with the amide on NAD.

Structural zinc site.

Mammalian alcohol dehydrogenases also have a structural zinc site. This Zn ion plays a structural role and is crucial for protein stability. The structures of the catalytic and structural zinc sites in horse liver alcohol dehydrogenase (HLADH) as revealed in crystallographic structures, which has been studied computationally with quantum chemical as well as with classical molecular dynamics methods. The structural zinc site is composed of four closely spaced cysteine ligands (Cys97, Cys100, Cys103, and Cys111 in the amino acid sequence) positioned in an almost symmetric tetrahedron around the Zn ion. A recent study showed that the interaction between zinc and cysteine is governed by primarily an electrostatic contribution with an additional covalent contribution to the binding.

Types.

Human.

In humans, ADH exists in multiple forms as a dimer and is encoded by at least seven different genes. There are five classes (I-V) of alcohol dehydrogenase, but the hepatic forms that are used primarily in humans are class 1. Class 1 consists of α, β, and γ subunits that are encoded by the genes ADH1A, ADH1B, and ADH1C. The enzyme is present at high levels in the liver and the lining of the stomach. It catalyzes the oxidation of ethanol to acetaldehyde (ethanal):  This allows the consumption of alcoholic beverages, but its evolutionary purpose is probably the breakdown of alcohols naturally contained in foods or produced by bacteria in the digestive tract.  Another evolutionary purpose may be metabolism of the endogenous alcohol vitamin A (retinol), which generates the hormone retinoic acid, although the function here may be primarily the elimination of toxic levels of retinol.  Alcohol dehydrogenase is also involved in the toxicity of other types of alcohol: For instance, it oxidizes methanol to produce formaldehyde and ethylene glycol to ultimately yield glycolic and oxalic acids. Humans have at least six slightly different alcohol dehydrogenases. Each is a dimer (i.e., consists of two polypeptides), with each dimer containing two zinc ions Zn. One of those ions is crucial for the operation of the enzyme: It is located at the catalytic site and holds the hydroxyl group of the alcohol in place.  Alcohol dehydrogenase activity varies between men and women, between young and old, and among populations from different areas of the world. For example, young women are unable to process alcohol at the same rate as young men because they do not express the alcohol dehydrogenase as highly, although the inverse is true among the middle-aged. The level of activity may not be dependent only on level of expression but also on allelic diversity among the population.  The human genes that encode class II, III, IV, and V alcohol dehydrogenases are ADH4, ADH5, ADH7, and ADH6, respectively.

Yeast and bacteria.

Unlike humans, yeast and bacteria (except lactic acid bacteria, and "E. coli" in certain conditions) do not ferment glucose to lactate. Instead, they ferment it to ethanol and. The overall reaction can be seen below:  In yeast and many bacteria, alcohol dehydrogenase plays an important part in fermentation: Pyruvate resulting from glycolysis is converted to acetaldehyde and carbon dioxide, and the acetaldehyde is then reduced to ethanol by an alcohol dehydrogenase called ADH1. The purpose of this latter step is the regeneration of NAD, so that the energy-generating glycolysis can continue. Humans exploit this process to produce alcoholic beverages, by letting yeast ferment various fruits or grains. Yeast can produce and consume their own alcohol.  The main alcohol dehydrogenase in yeast is larger than the human one, consisting of four rather than just two subunits. It also contains zinc at its catalytic site. Together with the zinc-containing alcohol dehydrogenases of animals and humans, these enzymes from yeasts and many bacteria form the family of "long-chain"-alcohol dehydrogenases.  Brewer's yeast also has another alcohol dehydrogenase, ADH2, which evolved out of a duplicate version of the chromosome containing the ADH1 gene. ADH2 is used by the yeast to convert ethanol back into acetaldehyde, and it is expressed only when sugar concentration is low. Having these two enzymes allows yeast to produce alcohol when sugar is plentiful (and this alcohol then kills off competing microbes), and then continue with the oxidation of the alcohol once the sugar, and competition, is gone.

Plants.

In plants, ADH catalyses the same reaction as in yeast and bacteria to ensure that there is a constant supply of NAD. Maize has two versions of ADH - ADH1 and ADH2, "Arabidopsis thaliana" contains only one ADH gene. The structure of "Arabidopsis" ADH is 47%-conserved, relative to ADH from horse liver. Structurally and functionally important residues, such as the seven residues that provide ligands for the catalytic and noncatalytic zinc atoms, however, are conserved, suggesting that the enzymes have a similar structure. ADH is constitutively expressed at low levels in the roots of young plants grown on agar. If the roots lack oxygen, the expression of "ADH" increases significantly. Its expression is also increased in response to dehydration, to low temperatures, and to abscisic acid, and it plays an important role in fruit ripening, seedlings development, and pollen development. Differences in the sequences of "ADH" in different species have been used to create phylogenies showing how closely related different species of plants are. It is an ideal gene to use due to its convenient size (2–3 kb in length with a ≈1000 nucleotide coding sequence) and low copy number.

Iron-containing.

A third family of alcohol dehydrogenases, unrelated to the above two, are iron-containing ones. They occur in bacteria and fungi. In comparison to enzymes the above families, these enzymes are oxygen-sensitive. Members of the iron-containing alcohol dehydrogenase family include:

Other types.

A further class of alcohol dehydrogenases belongs to quinoenzymes and requires quinoid cofactors (e.g., pyrroloquinoline quinone, PQQ) as enzyme-bound electron acceptors. A typical example for this type of enzyme is methanol dehydrogenase of methylotrophic bacteria.

Applications.

In biotransformation, alcohol dehydrogenases are often used for the synthesis of enantiomerically pure stereoisomers of chiral alcohols. Often, high chemo- and enantioselectivity can be achieved. One example is the alcohol dehydrogenase from "Lactobacillus brevis" ("Lb"ADH), which is described to be a versatile biocatalyst. The high chemospecificity has been confirmed also in the case of substrates presenting two potential redox sites. For instance cinnamaldehyde presents both aliphatic double bond and aldehyde function. Unlike conventional catalysts, alcohol dehydrogenases are able to selectively act only on the latter, yielding exclusively cinnamyl alcohol.  In fuel cells, alcohol dehydrogenases can be used to catalyze the breakdown of fuel for an ethanol fuel cell. Scientists at Saint Louis University have used carbon-supported alcohol dehydrogenase with poly(methylene green) as an anode, with a nafion membrane, to achieve about 50 μA/cm.  In 1949, E. Racker defined one unit of alcohol dehydrogenase activity as the amount that causes a change in optical density of 0.001 per minute under the standard conditions of assay. Recently, the international definition of enzymatic unit (E.U.) has been more common: one unit of Alcohol Dehydrogenase will convert 1.0 μmole of ethanol to acetaldehyde per minute at pH 8.8 at 25 °C.

Clinical significance.

Alcoholism.

There have been studies showing that variations in ADH that influence ethanol metabolism have an impact on the risk of alcohol dependence. The strongest effect is due to variations in ADH1B that increase the rate at which alcohol is converted to acetaldehyde. One such variant is most common in individuals from East Asia and the Middle East, another is most common in individuals from Africa. Both variants reduce the risk for alcoholism, but individuals can become alcoholic despite that. Researchers have tentatively detected a few other genes to be associated with alcoholism, and know that there must be many more remaining to be found. Research continues in order to identify the genes and their influence on alcoholism.

Drug dependence.

Drug dependence is another problem associated with ADH, which researchers think might be linked to alcoholism. One particular study suggests that drug dependence has seven ADH genes associated with it, however, more research is necessary. Alcohol dependence and other drug dependence may share some risk factors, but because alcohol dependence is often comorbid with other drug dependences, the association of ADH with the other drug dependencies may not be causal.

Poisoning.

Fomepizole, a drug that competitively inhibits alcohol dehydrogenase, can be used in the setting of acute methanol or ethylene glycol toxicity. This prevents the conversion of the methanol or ethylene glycol to its toxic metabolites (such as formic acid, formaldehyde, or glycolate). The same effect is also sometimes achieved with ethanol, again by competitive inhibition of ADH.

Alcohol dehydrogenases (ADH) () are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide (NAD) to NADH. In humans and many other animals, they serve to break down alcohols that otherwise are toxic, and they also participate in generation of useful aldehyde, ketone, or alcohol groups during biosynthesis of various metabolites. In yeast, plants, and many bacteria, some alcohol dehydrogenases catalyze the opposite reaction as part of fermentation to ensure a constant supply of NAD.

Alkoholdehydrogenáza (ADH) je enzym ze skupiny dehydrogenáz, který katalyzuje přeměnu primárních a sekundárních alkoholů na jim odpovídající aldehydy či ketony. Enzymy ze skupiny alkoholdehydrogenáz obsahují zinek a byly nalezeny nejen u člověka, ale i mnoha ostatních živočichů, rostlin, kvasinek či bakterií. U kvasinek například katalyzuje poslední krok v metabolismu alkoholických sloučenin.


Design.

A ground-effect vehicle needs some forward velocity to produce lift dynamically and the principal benefit of operating a wing in ground effect is to reduce its lift-dependent drag. The basic design principle is that the closer the wing operates to an external surface such as the ground, when it is said to be in ground effect, the more efficient it becomes.  An airfoil passing through air increases air pressure on the underside, while decreasing pressure across the top. The high and low pressures are maintained until they flow off the ends of the wings, where they form vortices which in turn are the major cause of lift-induced drag—normally a large portion of the drag affecting an aircraft. The higher the aspect ratio of the wing (that is, the longer and skinnier it is), the less induced drag created for each unit of lift and the greater the efficiency of the particular wing. This is the primary reason gliders have long and skinny wings.  Placing the same wing near a surface such as the water or the ground has the effect of greatly increasing the aspect ratio, but without having the complications associated with a long and slender wing, so that the short stubs on a GEV can produce just as much lift as the much larger wing on a transport aircraft, though it can do this only when close to the earth's surface. Once sufficient speed has built up, some GEVs may be capable of leaving ground effect and functioning as normal aircraft until they approach their destination. The distinguishing characteristic is that they are unable to land or take off without a significant amount of help from the ground effect cushion, and cannot climb until they have reached a much higher speed.  A GEV is sometimes characterized as a transition between a hovercraft and an aircraft, although this is not correct as a hovercraft is statically supported upon a cushion of pressurised air from an onboard downward-directed fan. Some GEV designs, such as the Russian "Lun" and "Dingo", have used forced blowing under the wing by auxiliary engines to increase the high pressure area under the wing to assist the takeoff; however they differ from hovercraft in still requiring forward motion to generate sufficient lift to fly.  Although the GEV may look similar to the seaplane and share many technical characteristics, it is generally not designed to fly out of ground effect. It differs from the hovercraft in lacking low-speed hover capability in much the same way that a fixed-wing airplane differs from the helicopter. Unlike the hydrofoil, it does not have any contact with the surface of the water when in "flight". The ground-effect vehicle constitutes a unique class of transportation.

Wing configurations.

Straight wing.

Used by the Russian Rostislav Alexeyev for his ekranoplan. The wings are significantly shorter than those of comparable aircraft, and this configuration requires a high aft-placed horizontal tail to maintain stability. The pitch and altitude stability comes from the lift slope difference between a front low wing in ground-effect (commonly the main wing) and an aft, higher-located second wing nearly out of ground-effect (generally named a stabilizer).

Reverse-delta wing.

Developed by Alexander Lippisch, this wing allows stable flight in ground-effect through self-stabilization. This is the main Class B form of GEV.

Tandem wings.

Tandem wings can have three configurations:

Advantages and disadvantages.

Given similar hull size and power, and depending on its specific design, the lower lift-induced drag of a GEV, as compared to an aircraft of similar capacity, will improve its fuel efficiency and, up to a point, its speed. GEVs are also much faster than surface vessels of similar power, because they avoid drag from the water.  On the water the aircraft-like construction of GEVs increases the risk of damage, should they fail to avoid other vessels. Furthermore, the limited number of egress points make it more difficult to evacuate the vehicle in an emergency.  Since most GEVs are designed to operate from water, accidents and engine failure typically are less hazardous than in a land-based aircraft, but the lack of altitude control leaves the pilot with fewer options for avoiding collision, and to some extent that discounts such benefits. Low altitude brings high speed craft into conflict with ships, buildings and rising land, which may not be sufficiently visible in poor conditions to avoid, and GEVs may be unable to climb over or turn sharply enough to avoid collisions. While drastic, low level maneuvers risk contact with solid or water hazards beneath. Aircraft can climb over most obstacles, but GEVs are more limited.  In high winds, take-off must be into the wind, which takes the craft across successive lines of waves, causing heavy pounding, which both stresses the craft and makes passengers uncomfortable. In light winds, waves may be in any direction, which can make control difficult as each wave causes the vehicle to both pitch and roll. Their light construction makes their ability to operate in higher sea states less than that of conventional ships, but greater than the ability of hovercraft or hydrofoils, which are closer to the surface of the water. The demise of the seaplane was a result of its inability to take off or land in rough sea conditions even while flying conditions were good, and its use lasted only until runways were more commonly available. GEVs are similarly limited.  Like conventional aircraft, greater power is needed for takeoff, and, like seaplanes, ground-effect vehicles must get on the step before they can accelerate to flight speed. Careful design, usually with multiple redesigns of hullforms, is required to get this right, which increases engineering costs. This obstacle is more difficult for GEVs with short production runs to overcome. For the vehicle to work, its hull needs to be stable enough longitudinally to be controllable yet not so stable that it cannot lift off the water.  The bottom of the vehicle must be formed to avoid excessive pressures on landing and taking off without sacrificing too much lateral stability, and it must not create too much spray, which damages the airframe and the engines. The Russian ekranoplans show evidence of fixes for these exact problems in the form of multiple chines on the forward part of the hull undersides and in the forward location of the jet engines.  Finally, limited utility has kept production levels low enough that it has been impossible to amortize development costs sufficiently to make GEVs competitive with conventional aircraft.  A 2014 NASA study claims that use of GEVs for passenger travel will lead to cheaper flights, increased accessibility and less pollution.

Classification.

One difficulty which has delayed GEV development is the classification and legislation to be applied. The International Maritime Organization has studied the application of rules based on the International Code of Safety for High-Speed Craft (HSC code) which was developed for fast ships such as hydrofoils, hovercraft, catamarans and the like. The Russian Rules for classification and construction of small type A ekranoplans is a document upon which most GEV design is based. However, in 2005, the IMO classified the WISE or GEV under the category of ships.  The International Maritime Organization recognizes three types of GEVs: These classes currently only apply to craft carrying 12 passengers or more.

History.

By the 1920s, the "ground effect" phenomenon was well-known, as pilots found that their airplanes appeared to become more efficient as they neared the runway surface during landing. In 1934 the US National Advisory Committee for Aeronautics issued Technical Memorandum 771, "Ground Effect on the Takeoff and Landing of Airplanes", which was a translation into English of a summary of research up to that point on the subject. The French author Maurice Le Sueur had added a suggestion based on this phenomenon: "Here the imagination of inventors is offered a vast field. The ground interference reduces the power required for level flight in large proportions, so here is a means of rapid and at the same time "economic" locomotion: Design an airplane which is always within the ground-interference zone. At first glance this apparatus is dangerous because the ground is uneven and the altitude called skimming permits no freedom of maneuver. But on large-sized aircraft, over water, the question may be attempted..."  By the 1960s, the technology started maturing, in large part due to the independent contributions of Rostislav Alexeyev in the Soviet Union and German Alexander Lippisch, working in the United States. Alexeyev worked from his background as a ship designer whereas Lippisch worked as an aeronautical engineer. The influence of Alexeyev and Lippisch remains noticeable in most GEVs seen today.

Soviet Union.

Led by Alexeyev, the Soviet Central Hydrofoil Design Bureau () was the center of ground-effect craft development in the USSR. The vehicle came to be known as an ekranoplan (, экран "screen" + план "plane", from, literally "screen effect", or "ground effect" in English). The military potential for such a craft was soon recognized and Alexeyev received support and financial resources from Soviet leader Nikita Khrushchev.  Some manned and unmanned prototypes were built, ranging up to eight tons in displacement. This led to the development of a 550-ton military "ekranoplan" of length. The craft was dubbed the "Caspian Sea Monster" by U.S. intelligence experts, after a huge, unknown craft was spotted on satellite reconnaissance photos of the Caspian Sea area in the 1960s. With its short wings, it looked airplane-like in planform, but would obviously be incapable of flight. Although it was designed to travel a maximum of above the sea, it was found to be most efficient at, reaching a top speed of in research flights.  The Soviet "ekranoplan" program continued with the support of Minister of Defence Dmitriy Ustinov. It produced the most successful "ekranoplan" so far, the 125-ton A-90 "Orlyonok". These craft were originally developed as high-speed military transports and were usually based on the shores of the Caspian Sea and Black Sea. The Soviet Navy ordered 120 "Orlyonok"-class "ekranoplans", but this figure was later reduced to fewer than 30 vessels, with planned deployment mainly in the Black Sea and Baltic Sea fleets.  A few "Orlyonoks" served with the Soviet Navy from 1979 to 1992. In 1987, the 400-ton "Lun"-class "ekranoplan" was built as an anti-ship missile launch platform. A second "Lun", renamed "Spasatel", was laid down as a rescue vessel, but was never finished. The two major problems that the Soviet "ekranoplans" faced were poor longitudinal stability and a need for reliable navigation.  Minister Ustinov died in 1985, and the new Minister of Defence, Marshal Sokolov, cancelled funding for the program. Only three operational "Orlyonok"-class "ekranoplans" (with revised hull design) and one "Lun"-class "ekranoplan" remained at a naval base near Kaspiysk.  Since the dissolution of the Soviet Union, "ekranoplans" have been produced by the Volga Shipyard in Nizhniy Novgorod. Smaller "ekranoplans" for non-military use have been under development. The CHDB had already developed the eight-seat Volga-2 in 1985, and Technologies and Transport is developing a smaller version called the Amphistar. Beriev proposed a large craft of the type, the Be-2500, as a "flying ship" cargo carrier, but nothing came of the project.

Germany.

Lippisch Type and Hanno Fischer.

In Germany, Lippisch was asked to build a very fast boat for American businessman Arthur A. Collins. In 1963 Lippisch developed the X-112, a revolutionary design with reversed delta wing and T-tail. This design proved to be stable and efficient in ground effect and even though it was successfully tested, Collins decided to stop the project and sold the patents to a German company called Rhein Flugzeugbau (RFB), which further developed the inverse delta concept into the X-113 and the six seat X-114. These craft could be flown out of ground effect so that, for example, peninsulas could be overflown.  Hanno Fischer took over the works from RFB and created his own company, Fischer Flugmechanik, which eventually completed two models. The Airfisch 3 carried two persons, and the FS-8 carried six persons. The FS-8 was to be developed by Fischer Flugmechanik for a Singapore-Australian joint venture called Flightship. Powered by a V8 Chevrolet automobile engine rated at 337 kW, the prototype made its first flight in February 2001 in the Netherlands. The company no longer exists but the prototype craft was bought by Wigetworks, a company based in Singapore and renamed as AirFish 8. In 2010, that vehicle was registered as a ship in the Singapore Registry of Ships.  The University of Duisburg-Essen is supporting an ongoing research project to develop the "Hoverwing".

Gunther-Jörg-type tandem-airfoil flairboat.

German engineer Günther Jörg, who had worked on Alexeyev's first designs and was familiar with the challenges of GEV design, developed a GEV with two wings in a tandem arrangement, the Jörg-II. It was the third, manned, tandem-airfoil boat, named "Skimmerfoil", which was developed during his consultancy period in South Africa. It was a simple and low-cost design of a first 4-seater tandem-airfoil flairboat completely constructed of aluminium. The prototype has been in the SAAF Port Elizabeth Museum since 4 July 2007, remained there till (2013) and is now in private use. Pictures of the museum show the boat after a period of some years outside the museum and without protection against the sun.  The consultancy of Dipl. Ing. Günther Jörg who was specialist and insider of German Airplane Industry up from 1963 and a colleague of Alexander Lippisch and Hanno Fischer as well, was founded with a fundamental knowledge of Wing in ground effect physics, as well as results of fundamental tests under different conditions and designs having begun in 1960. During a period of more than 30 years Dipl. Ing. Gunther W. Jörg managed to build and fly successful a series of 15 different tandem-airfoil flairboats in different sizes and made of different materials.  The following tandem-airfoil flairboat (TAF) types had been built after a previous period of nearly 10 years of research and development:  Bigger concepts are: 25-seater, 32-seater, 60-seater, 80-seater and bigger up to the size of a passenger airplane.  All those tandem-airfoil flairboats are registered as motorboat and classified as type A WIG. In 1984, Gunther W. Jörg was decorated with "Philip Morris Award" for future transportation. In 1987, the Botec Company was founded. After his death in 2010 business is continued by his daughter and former assistant Ingrid Schellhaas with her company Tandem WIG Consulting.

Since the 1980s.

GEVs developed since the 1980s have been primarily smaller craft designed for the recreational and civilian ferry markets. Germany, Russia and the United States have provided most of the momentum with some development in Australia, China, Japan, Korea and Taiwan. In these countries and regions, small craft up to ten seats have been designed and built. Other larger designs as ferries and heavy transports have been proposed, but have not been carried to fruition.  Besides the development of appropriate design and structural configuration, special automatic control systems and navigation systems are also being developed. These include special altimeters with high accuracy for small altitude measurements and also lesser dependence on weather conditions. After extensive research and experimentation, it has been shown that "phase radio altimeters" are most suitable for such applications as compared to laser altimeter, isotropic or ultrasonic altimeters.  With Russian consultation, the United States Defense Advanced Research Projects Agency (DARPA) studied the Aerocon Dash 1.6 wingship.  Universal Hovercraft developed a flying hovercraft, a prototype of which first took flight in 1996. Since 1999, the company has offered plans, parts, kits and manufactured ground effect hovercraft called the Hoverwing.  In Singapore, Wigetworks has continued development and obtained certification from Lloyd's Register for entry into class. On 31 March 2011 AirFish 8-001 became one of the first GEVs to be flagged with the Singapore Registry of Ships, one of the largest ship registries. Wigetworks has also partnered with National University of Singapore's Engineering Department to develop higher capacity GEVs.  In Korea, Wing Ship Technology Corporation has developed and tested a 50-seat passenger version of a GEV named the WSH-500.  Iran deployed three squadrons of Bavar 2 two-seat GEVs in September, 2010. This GEV carries one machine gun and surveillance gear, and incorporates features which reduce its radar signature in a similar manner to stealth. In October 2014, satellite images showed new images of the GEV in a shipyard in south of Iran. The GEV has two engines and no armament.  The designers Burt Rutan in 2011 and Korolev in 2015 have shown GEV projects.  Estonian transport company Sea Wolf Express plans to launch passenger service in 2019 between Helsinki and Tallinn, a distance of 87 km taking only half an hour, using a Russian-built ekranoplan. The company has ordered 15 ekranoplans with maximum speed of 185 km/h and capacity of 12 passengers and they are built by Russian RDC Aqualines.

A ground-effect vehicle (GEV), also called a wing-in-ground-effect (WIG), ground-effect craft, wingship or ekranoplan (), is a vehicle that is designed to attain sustained flight over a level surface (usually over the sea) by making use of ground effect, the aerodynamic interaction between the wings and the surface. The type is typically intended to operate from water like a flying boat, but some can operate over any flat area such as frozen lakes or flat plains similar to a hovercraft.

Ekranoplán je stroj na pomezí letadla, vznášedla a lodě. Ekranoplán létá na principu tzv. dynamického přízemního efektu, kdy je letoun nadnášen tím, že mezi krátkými nosnými plochami a vodní hladinou vzniká „nosný polštář“ a vztlak zvyšuje i tzv. přízemní jev – omezení indukovaného odporu křídla o malé štíhlosti blízkostí země či vodní hladiny (odtud anglické označení ekranoplánů WIG – wing in ground effect). Díky podobnému principu se dokážou vznést z hladiny vodní ptáci. Tato technologie byla sice známá už před druhou světovou válkou, ale skutečný výzkum těchto strojů vzrostl až v 60. létech v SSSR pod vedením inženýra Rostislava Alexejeva a to především pro vojenské účely. Díky tomu, že nejde o tradiční letadlo či loď, nelze stroj jednoznačně zařadit do jednotlivé kategorie a v samotném SSSR probíhaly spory letectva a námořnictva o to, komu budou ekranoplány patřit.


Early life.

Martov was born to a Jewish middle-class family in Constantinople, Turkey (modern day Istanbul). His sister was fellow Menshevik leader Lydia Dan. He was arrested as a teenager, and his grandfather paid 300 roubles to bail him out. Instead of accepting his grandfather's suggestion of emigrating to the United States of America, he chose to be exiled for two years in Vilna (now Vilnius). He recounted that the famine crisis of 1891 made him a Marxist: "It suddenly became clear to me how superficial and groundless the whole of my revolutionism had been until then, and how my subjective political romanticism was dwarfed before the philosophical and sociological heights of Marxism".  In Russia, Martov was originally a close colleague of Vladimir Lenin and with him, and small group of Marxist intellectuals, founded the League of Struggle for the Emancipation of the Working Class in 1895. The founders were arrested almost immediately after its establishment; it could however claim some success when local activists of the union organised the textile strike of 30,000 workers in 1896. Both Martov and Lenin were exiled to Siberia for this: Martov was sent to the village of Turukhansk in the Arctic, while Lenin was sent to Shushenskoye in the comparatively warm "Siberian Italy".

Exile.

Forced to leave Russia and with other radical political figures living in exile, Martov joined the Russian Social Democratic Labour Party (RSDLP). Martov and Lenin were both founding members of the party journal "Iskra" in 1900. In Munich, Martov was on the editorial board alongside Lenin and Potresov. Martov was one of the Marxists who wanted Nikolay Bauman expelled from the party after an incident where he drove a party member to suicide after drawing a vicious cartoon of her.  Martov was initially on good terms with the Jewish Bund. However, Martov would eventually have a critical parallel role with Lenin in the opposition to the Bund from the positions of the RSDLP. At the Second Congress of the RSDLP in London in 1903, there was a dispute between Martov and Lenin over who was to be considered a'member' of the RSDLP. Lenin had published his ideas for moving the party forward in his pamphlet "What Is to Be Done?", which was a document putting forward the views of the entire Iskra group led by Lenin and Martov. However, in the London Congress of the party, differing definitions of party membership were put forward by the two men. Lenin argued for a restricted membership of fully committed cadre while Martov argued for a looser interpretation of membership. Martov later refused to participate in the editorial board of "Iskra" with Lenin and Georgi Plekhanov, after Lenin had removed the three Menshevik veterans Axelrod, Potresov and Zasulich.

Ideology.

Martov and Lenin based their ideas for party organization on those prevailing in the European social democratic parties, with particular influence from Germany. The split with Lenin was based in differences of the wording of article one of the party statute, concerning membership definition, at the Second Party Congress in Brussels. Martov believed that RSDLP sympathizers who were willing to obey the party's leadership and recognize the party's program should be admitted as party members, as well as those people who were fully paid up party members who participated in one of party's organizations; while Lenin wanted clear dividing lines between party members and party sympathizers, with party membership being limited to those people who were fully paid up party members who participated in one of the party's organisations. Martov's view prevailed at first 28 to 23 votes, but the 5 Bundist delegates and 2 Economists walked out in reaction for the denying of their respective issues, and Lenin's view now won a slight majority. They referred to themselves as Bolsheviks throughout the Congress, hence their adoption of the name Bolshevik which literally means 'person of the majority'. The minority or 'Menshevik' faction adopted the corresponding title. The vote on the editorial board was not seen as important by any of the disputants at the time, and in fact the Bolsheviks were generally in a minority but some delegates had not been present for the crucial vote who would otherwise have voted for the Mensheviks.  Martov was one of the Jewish Marxist leaders (alongside Trotsky), who rejected the demands for Jewish national autonomy, with the Iskra group favouring class interests over nationalism; he was therefore deeply opposed to the Bundists' Jewish nationalism.  Martov was described as being "too good an intellectual to be a successful politician", as he often was held back by his integrity, and "philosophical approach" to matters of politics. He tended to select political allies primarily by the "coherence of their general worldview", instead of "practicality" or "timeliness". His "high minded approach" would later win rounds of applause among the socialist intelligentsia. Nonetheless, Martov's noble principles made him too "soft" and "indecisive", at time when the opposite were politically required of him. He has been described as a "brilliant intellectual and party theoretician".

Activity.

Together with fellow Wilno Social Democrat, Arkady Kremer, Martov explained the strategy involving mass agitation and participating in Jewish strikes, by also sometimes learning Yiddish to win over their support, in the work "On Agitation" (1895). The plan detailed that workers were to see a need for broader political campaigning through participating in strikes, led by the Social Democrats as trade unions were banned under the Tsarist regime. Martov became one of the outstanding Menshevik leaders along with George Plekhanov, Fedor Dan and Irakli Tsereteli. Leon Trotsky too was a member of the Menshevik faction for a brief period but soon broke with them.  Martov was in exile during the strikes following Bloody Sunday.  After the reforms brought about by the 1905 Revolution, Martov argued that it was the role of revolutionaries to provide a militant opposition to the new bourgeois government. He advocated the joining together of a network of organisations, trade unions, cooperatives, village councils and soviets, to harass the bourgeois government until the economic and social conditions made it possible for a socialist revolution to take place.  Martov was always to be found on the left wing of the Menshevik faction and supported the reunification with the Bolsheviks in 1905. That fragile unity was short lived, however, and by 1907 the two factions had again split in two. In 1911 Martov notably wrote the pamphlet "Spasiteli ili uprazdniteli? Kto i kak razrushal R.S.-D.R.P.," "Saviours or destroyers? Who destroyed the RSDLP and how", which denounced the Bolsheviks for, among other things, raising money by "expropriations," that is, robbing banks. This pamphlet was denounced by both Kautsky and Lenin.  Martov was joined by Trotsky in Paris in November 1914, where he collaborated with him on "Nashe Slovo" ("Our Word"). He was the only contributor to "Nashe Slovo" not to align with Lenin in 1917.  In 1914, Martov opposed the First World War, which he viewed as an imperialist war in terms very similar to those of Lenin and Trotsky. He therefore became the central leader of the Menshevik Internationalist faction which organized in opposition to the Menshevik Party leadership. In 1915, he sided with Lenin at an international conference in Switzerland, but later repudiated the Bolsheviks. The 'internationalist' minority in the Menshevik party favored a campaign for 'democratic peace'.  Martov was the designer of the idea of exchanging Russian Marxist exiles for German citizens interned in Russia. This way, the Russian Marxists revolutionary leaders, including Lenin, would manage to return to Russia following the revolution of 1917. The Provisional Government was however unwilling to agree to the exchange, and Martov agreed to wait.

The February Revolution.

At the onset of the 1917 Revolution, Martov was in Zurich with Lenin.  After the February Revolution in 1917, Martov returned to Russia but was too late to stop some Mensheviks joining the Provisional Government. He strongly criticized those Mensheviks such as Irakli Tsereteli and Fedor Dan who, now part of Russia's government, supported the war effort. However, at a conference held on 18 June 1917, he failed to gain the support of the delegates for a policy of immediate peace negotiations with the Central Powers.  He was unable to enter in an alliance with his rival Lenin to form a coalition in 1917, despite it being the 'logical outcome' according to the majority of his left wing supporters in the Menshevik faction.

The October Revolution.

When the Bolsheviks came to power as a result of the October Revolution in 1917, Martov became politically marginalised. He believed that the only way to avoid a civil war was through a 'united democratic government' based on the parties of the soviet. His proposal was met with 'torrents of applause' in the Soviet. Martov's faction as a whole was however isolated. His view was denounced by Trotsky. This is best exemplified by Trotsky's comment to him and other party members as they left the first meeting of the council of Soviets after 25 October 1917 in disgust at the way in which the Bolsheviks had seized political power: "You are pitiful isolated individuals; you are bankrupts; your role is played out. Go where you belong from now on—into the dustbin of history!" To this Martov replied in a moment of rage, "Then we'll leave!", and then walked in silence away without looking back. He paused at the exit, seeing a young Bolshevik worker wearing a black shirt with a broad leather belt, standing in the shadow of the portico. The young man turned on Martov with unconcealed bitterness: "And we amongst ourselves had thought, Martov would at least remain with us". Martov stopped, and with a characteristic movement, tossed up his head to emphasize his reply: "One day you will understand the crime in which you are taking part". Waving his hand wearily, he left the hall.  For a while Martov led the Menshevik opposition group in the Constituent Assembly until the Bolsheviks abolished it. Later, when a factory section chose Martov as their delegate ahead of Lenin in a Soviet election, it found its supplies reduced soon afterwards.

Civil war.

During the Russian Civil War, Martov supported the Red Army against the White Army; however, he continued to denounce the persecution of non-violent political opponents of the Bolsheviks, whether Social Democrats, trade unionists, anarchists, or newspapers.  Speaking of the Red Terror, Martov said: "The beast has licked hot human blood. The man-killing machine is brought into motion... But blood breeds blood... We witness the growth of the bitterness of the civil war, the growing bestiality of men engaged in it."  In October 1920, Martov was given permission to legally leave Russia and go to Germany. Martov spoke at the Halle Congress of the Independent Social Democratic Party of Germany later that month. Martov had not intended to stay in Germany indefinitely, and only did so after the Mensheviks were outlawed in March 1921, following the Tenth Congress of the ruling Communist Party. In 1922, learning Martov was ill, Lenin asked Stalin to transfer funds to Berlin to contribute to Martov's medical care, but Stalin refused. Martov died in Schömberg, Germany, in April 1923. Before his fatal illness, he launched the newspaper "Socialist Messenger", which remained the publication of the Mensheviks in exile in Berlin, Paris, and eventually New York until the last of them had died.

External links.

Democratic socialists

Julius Martov or L. Martov (born Yuliy Osipovich Tsederbaum/Zederbaum; 24 November 1873 – 4 April 1923) was a politician and revolutionary who became the leader of the Mensheviks in early 20th-century Russia. He was an old friend and mentor of Leon Trotsky, who described him as the "Hamlet of Democratic Socialism". Vladimir Lenin, his longtime political opponent, confessed in 1921 that his single greatest regret was "that Martov is not with us. What an amazing comrade he is, what a pure man!" According to his sister and fellow Menshevik, Lydia Dan, Martov had an "inexhaustible charm that attracted people". As a result, some commented it was frequently difficult to record why they followed him, and he confessed that "I have the nasty privilege of being liked by people".

Julij Osipovič Martov (rusky "Юлий Осипович Мартов", vlastním jménem Cederbaum, 24. listopadu 1873 Istanbul, Osmanská říše – 4. dubna 1923 Schömberg, Německo) byl ruský politik a žurnalista, vůdce frakce menševiků v rámci Ruské sociálně demokratické dělnické strany (RSDDS).


Characteristics.

The genre is related to, and similar to, goregrind, but minor differences from goregrind include pornogrind having simpler, slower, and more rock-like songs as well as the genre's pornographic theme present in lyrics and album artwork, which "would keep them out of most stores." "Zero Tolerance" described pornogrind as "the most downright perverted of the lot, often adding a dollop of filthy groove and vocals straight from the toilet." Natalie Purcell, however, in her book "Death Metal Music: The Passion and Politics of a Subculture", suggests that pornogrind is defined solely on the basis of its lyrical content and unique imagery, its focus on pornographic content. Rolling Stone has said that it's "basically just grindcore, but with an over-the-top, juvenile obsession with sex, violence and the ways the two could combine on a woman’s body. Think samples from porno movies, lyrics about sexual violence and gross-out album art."  Notable bands of the genre include Gut and Cock and Ball Torture.

Controversy.

The genre saw mainstream media attention after the 2019 Dayton shooting when it came to light that the perpetrator, Connor Betts, performed live vocals in the pornogrind group Menstrual Munchies on multiple occasions. After the attack, artists, performers and avid fans of the genre were outraged after outlets such as Vice attempted linking pornogrind's obscene themes to the gunsman's motives. While pornogrind artists made it very clear that they do not approve of real life violence or Betts' actions, there were nevertheless a handful of pornogrind musicians who deleted their social media profiles, put their bands on a hiatus or outright quit the genre after the attack occurred.

Pornogrind (also known as porngrind or pornogore) is a musical microgenre offshoot of goregrind that lyrically deals with sexual and pornographic themes, hence the name.

Pornogrind, jenž je někdy známý i jako porno grind, porno-grind či porn grind je hudební podžánr grindcore a death metalu, ve kterém se vyskytují texty se sexuálními tématy.


Applications.

The equipment used for communications over multi-mode optical fiber is less expensive than that for single-mode optical fiber. Typical transmission speed and distance limits are 100 Mbit/s for distances up to 2 km (100BASE-FX), 1 Gbit/s up to 1000 m, and 10 Gbit/s up to 550 m.  Because of its high capacity and reliability, multi-mode optical fiber generally is used for backbone applications in buildings. An increasing number of users are taking the benefits of fiber closer to the user by running fiber to the desktop or to the zone. Standards-compliant architectures such as Centralized Cabling and fiber to the telecom enclosure offer users the ability to leverage the distance capabilities of fiber by centralizing electronics in telecommunications rooms, rather than having active electronics on each floor.  Multi-mode fiber is used for transporting light signals to and from miniature fiber optic spectroscopy equipment (spectrometers, sources, and sampling accessories) and was instrumental in the development of the first portable spectrometer.  Multi-mode fiber is also used when high optical powers are to be carried through an optical fiber, such as in laser welding.

Comparison with single-mode fiber.

The main difference between multi-mode and single-mode optical fiber is that the former has much larger core diameter, typically 50–100 micrometers; much larger than the wavelength of the light carried in it. Because of the large core and also the possibility of large numerical aperture, multi-mode fiber has higher "light-gathering" capacity than single-mode fiber. In practical terms, the larger core size simplifies connections and also allows the use of lower-cost electronics such as light-emitting diodes (LEDs) and vertical-cavity surface-emitting lasers (VCSELs) which operate at the 850 nm and 1300 nm wavelength (single-mode fibers used in telecommunications typically operate at 1310 or 1550 nm ). However, compared to single-mode fibers, the multi-mode fiber bandwidth–distance product limit is lower. Because multi-mode fiber has a larger core-size than single-mode fiber, it supports more than one propagation mode; hence it is limited by modal dispersion, while single mode is not.  The LED light sources sometimes used with multi-mode fiber produce a range of wavelengths and these each propagate at different speeds. This chromatic dispersion is another limit to the useful length for multi-mode fiber optic cable. In contrast, the lasers used to drive single-mode fibers produce coherent light of a single wavelength. Because of the modal dispersion, multi-mode fiber has higher pulse spreading rates than single mode fiber, limiting multi-mode fiber's information transmission capacity.  Single-mode fibers are often used in high-precision scientific research because restricting the light to only one propagation mode allows it to be focused to an intense, diffraction-limited spot.  Jacket color is sometimes used to distinguish multi-mode cables from single-mode ones. The standard TIA-598C recommends, for non-military applications, the use of a yellow jacket for single-mode fiber, and orange or aqua for multi-mode fiber, depending on type. Some vendors use violet to distinguish higher performance OM4 communications fiber from other types.

Types.

Multi-mode fibers are described by their core and cladding diameters. Thus, 62.5/125 μm multi-mode fiber has a core size of 62.5 micrometres (μm) and a cladding diameter of 125 μm. The transition between the core and cladding can be sharp, which is called a step-index profile, or a gradual transition, which is called a graded-index profile. The two types have different dispersion characteristics and thus different effective propagation distance. Multi-mode fibers may be constructed with either graded or step-index profile.  In addition, multi-mode fibers are described using a system of classification determined by the ISO 11801 standard — OM1, OM2, and OM3 — which is based on the modal bandwidth of the multi-mode fiber. OM4 (defined in TIA-492-AAAD) was finalized in August 2009, and was published by the end of 2009 by the TIA. OM4 cable will support 125m links at 40 and 100 Gbit/s. The letters "OM" stand for "optical multi-mode".  For many years 62.5/125 μm (OM1) and conventional 50/125 μm multi-mode fiber (OM2) were widely deployed in premises applications. These fibers easily support applications ranging from Ethernet (10 Mbit/s) to gigabit Ethernet (1 Gbit/s) and, because of their relatively large core size, were ideal for use with LED transmitters. Newer deployments often use laser-optimized 50/125 μm multi-mode fiber (OM3). Fibers that meet this designation provide sufficient bandwidth to support 10 Gigabit Ethernet up to 300 meters. Optical fiber manufacturers have greatly refined their manufacturing process since that standard was issued and cables can be made that support 10 GbE up to 400 meters. Laser optimized multi-mode fiber (LOMMF) is designed for use with 850 nm VCSELs.  Older FDDI grade, OM1, and OM2 fiber can be used for 10 Gigabit ethernet through 10GBASE-LRM. This requires the SFP+ interface to support electronic dispersion compensation (EDC) however, so not all switches, routers and other equipment can use these SFP+ modules.  The migration to LOMMF/OM3 has occurred as users upgrade to higher speed networks. LEDs have a maximum modulation rate of 622 Mbit/s because they cannot be turned on/off fast enough to support higher bandwidth applications. VCSELs are capable of modulation over 10 Gbit/s and are used in many high speed networks.  Some 200 and 400 Gigabit Ethernet speeds use wavelength-division multiplexing (WDM) even for multi-mode fiber which isn't specified up to and including OM4. In 2017, OM5 has been standardized by TIA and ISO for WDM MMF, specifying not only a minimum modal bandwidth for 850 nm but a curve spanning from 850 to 953 nm.  Cables can sometimes be distinguished by jacket color: for 62.5/125 μm (OM1) and 50/125 μm (OM2), orange jackets are recommended, while aqua is recommended for 50/125 μm "laser optimized" OM3 and OM4 fiber. Some fiber vendors use violet for "OM4+". OM5 is officially colored lime green.  VCSEL power profiles, along with variations in fiber uniformity, can cause modal dispersion which is measured by differential modal delay (DMD). Modal dispersion is caused by the different speeds of the individual modes in a light pulse. The net effect causes the light pulse to spread over distance, introducing intersymbol interference. The greater the length, the greater the modal dispersion. To combat modal dispersion, LOMMF is manufactured in a way that eliminates variations in the fiber which could affect the speed that a light pulse can travel. The refractive index profile is enhanced for VCSEL transmission and to prevent pulse spreading. As a result, the fibers maintain signal integrity over longer distances, thereby maximizing the bandwidth.

Encircled flux.

The IEC 61280-4-1 (now TIA-526-14-B) standard defines "encircled flux" which specifies test light injection sizes (for various fiber diameters) to make sure the fiber core is not over-filled or under-filled to allow more reproducible (and less variable) link-loss measurements.

Multi-mode optical fiber is a type of optical fiber mostly used for communication over short distances, such as within a building or on a campus. Multi-mode links can be used for data rates up to 100 Gbit/s. Multi-mode fiber has a fairly large core diameter that enables multiple light modes to be propagated and limits the maximum length of a transmission link because of modal dispersion.

Vícevidové optické vlákno (zkratka MM, ) je v informatice typ optického vlákna, který je v počítačových sítích nejčastěji používán pro komunikaci na krátké vzdálenosti, jako například uvnitř budovy nebo areálu. Rychlost přenosu u vícevidových linek se pohybuje okolo 10 Mbit/s až 10 Gbit/s na vzdálenosti do 600 metrů, což je více než dostačující pro většinu LAN sítí.


Early life.

Pitt was the grandson of Thomas Pitt (1653–1726), the governor of Madras, known as "Diamond" Pitt for having discovered a diamond of extraordinary size and sold it to the Duke of Orléans for around £135,000. This transaction, as well as other trading deals in India, established the Pitt family fortune. After returning home the Governor was able to raise his family to a position of wealth and political influence: in 1691 he purchased the property of Boconnoc in Cornwall, which gave him control of a seat in Parliament. He made further land purchases and became one of the dominant political figures in the West Country, controlling seats such as the rotten borough of Old Sarum.  William's father was Robert Pitt (1680–1727), the eldest son of Governor Pitt, who served as a Tory Member of Parliament from 1705 to 1727. His mother was Harriet Villiers, the daughter of Edward Villiers-FitzGerald and the Irish heiress Katherine FitzGerald. Both William's paternal uncles Thomas and John were MPs, while his aunt Lucy married the leading Whig politician and soldier General James Stanhope. From 1717 to 1721 Stanhope served as effective First Minister in the Stanhope–Sunderland Ministry and was a useful political contact for the Pitt family until the collapse of the South Sea Bubble, a disaster which engulfed the government.  William Pitt was born at Golden Square, Westminster, on 15 November 1708. His older brother Thomas Pitt had been born in 1704. There were also five sisters: Harriet, Catherine, Ann, Elizabeth, and Mary. From 1719 William was educated at Eton College along with his brother. William disliked Eton, later claiming that "a public school might suit a boy of turbulent disposition but would not do where there was any gentleness". It was at school that Pitt began to suffer from gout. Governor Pitt died in 1726, and the family estate at Boconnoc passed to William's father. When he died the following year, Boconnoc was inherited by William's elder brother, Thomas Pitt of Boconnoc.  In January 1727, William was entered as a gentleman commoner at Trinity College, Oxford. There is evidence that he was an extensive reader, if not a minutely accurate classical scholar. Demosthenes was his favourite author. William diligently cultivated the faculty of expression by the practice of translation and re-translation. In these years he became a close friend of George Lyttelton, who would later become a leading politician. In 1728 a violent attack of gout compelled him to leave Oxford University without finishing his degree. He then chose to travel abroad, from 1728 attending Utrecht University in the Dutch Republic, gaining a knowledge of Hugo Grotius and other writers on international law and diplomacy. It is not known how long Pitt studied at Utrecht; by 1730 he had returned to his brother's estate at Boconnoc in Cornwall.  He had recovered from the attack of gout, but the disease proved intractable, and he continued to be subject to attacks of growing intensity at frequent intervals until his death.

Rise to prominence.

Patriot Whigs.

Pitt soon joined a faction of discontented Whigs known as the Patriots who formed part of the opposition. The group commonly met at Stowe House, the country estate of Lord Cobham, who was a leader of the group. Cobham had originally been a supporter of the government under Sir Robert Walpole, but a dispute over the controversial Excise Bill of 1733 had seen them join the opposition. Pitt swiftly became one of the faction's most prominent members.  Pitt's maiden speech in the Commons was delivered in April 1736, in the debate on the congratulatory address to George II on the marriage of his son Frederick, Prince of Wales. He used the occasion to pay compliments, and there was nothing striking in the speech as reported,

Spanish war.

During the 1730s Britain's relationship with Spain had slowly declined. Repeated cases of reported Spanish mistreatment of British merchants, whom they accused of smuggling, caused public outrage, particularly the incident of Jenkins' Ear. Pitt was a leading advocate of a more hard-line policy against Spain, and often castigated Walpole's government for its weakness in dealing with Madrid. Pitt spoke out against the Convention of El Pardo which aimed to settle the dispute peacefully. In the speech against the Convention in the House of Commons on 8 March 1739 Pitt said:  When trade is at stake, it is your last entrenchment; you must defend it, or perish... Sir, Spain knows the consequence of a war in America; whoever gains, it must prove fatal to her... is this any longer a nation? Is this any longer an English Parliament, if with more ships in your harbours than in all the navies of Europe; with above two millions of people in your American colonies, you will bear to hear of the expediency of receiving

Hanover.

Walpole and Newcastle were now giving the war in Europe, which had recently broken out, a much higher priority than the colonial conflict with Spain in the Americas. Prussia and Austria went to war in 1740, with many other European states soon joining in. There was a fear that France would launch an invasion of Hanover, which was linked to Britain through the crown of George II. To avert this Walpole and Newcastle decided to pay a large subsidy to both Austria

Fall of Walpole.

Many of Pitt's attacks on the government were directed personally at Sir Robert Walpole who had now been Prime Minister for twenty years. He spoke in favour of the motion in 1742 for an inquiry into the last ten years of Walpole's administration. In February 1742, following poor election results and the disaster at Cartagena, Walpole was at last forced to succumb to the long-continued attacks of opposition, resigned and took a peerage.  Pitt now expected a new government to be formed led by Pulteney and dominated by Tories and Patriot Whigs in which he could expect a junior position. Walpole was instead succeeded as Prime Minister by Lord Wilmington, though the real power in the new government was divided between Lord

Paymaster of the Forces.

It was with deep reluctance that the King finally agreed to give Pitt a place in the government. Pitt had changed his stance on a number of issues to make himself more acceptable to George, most notably the heated issue of Hanoverian subsidies. To force the matter, the Pelham brothers had to resign on the question whether he should be admitted or not, and it was only after all other arrangements had proved impracticable, that they were reinstated with Pitt appointed as Vice Treasurer of Ireland in February 1746. George continued to resent him however.  In May of the same year Pitt was promoted to the more important and lucrative office of paymaster-general, which gave him a place in the privy council, though not in the cabinet. Here he had an opportunity of displaying his public spirit and integrity in a way that deeply impressed both the king and the country. It had been the usual practise of previous paymasters to appropriate to themselves the interest of all money lying in their hands by way of advance, and also to accept a commission of 1/2% on all foreign subsidies. Although there was no strong public sentiment against the practice, Pitt completely refused to profit by it. All advances were lodged by him in the Bank of England until required, and all subsidies were paid over without deduction, even though it was pressed upon him, so that he did not draw a shilling from his office beyond the salary legally attaching to it. Pitt ostentatiously made this clear to everyone, although he was in fact following what Henry Pelham had done when he had held the post between 1730 and 1743. This helped to establish Pitt's reputation with the British people for honesty and placing the interests of the nation before his own.  The administration formed in 1746 lasted without major changes until 1754. It would appear from his published correspondence that Pitt had a greater influence in shaping its policy than his comparatively subordinate position would in itself have entitled him to. His support for measures, such as the Spanish Treaty and the continental subsidies, which he had violently denounced when in opposition was criticised by his enemies as an example of his political opportunism.  Between 1746 and 1748 Pitt worked closely with Newcastle in formulating British military and diplomatic strategy. He shared with Newcastle a belief that Britain should continue to fight until it could receive generous peace terms – in contrast to some such as Henry Pelham who favoured an immediate peace. Pitt was personally saddened when his friend and brother-in-law Thomas Grenville was killed at the naval First Battle of Cape Finisterre in 1747. However, this victory helped secure British supremacy of the sea which gave the British a stronger negotiating position when it came to the peace talks that ended the war. At the Treaty of Aix-la-Chapelle in 1748 British colonial conquests were exchanged for a French withdrawal from Brussels. Many saw this as merely an armistice and awaited an imminent new war.

Southern Secretary.

In December 1756, Pitt, who now sat for Okehampton, became Secretary of State for the Southern Department, and Leader of the House of Commons under the premiership of the Duke of Devonshire. Upon entering this coalition, Pitt said to Devonshire: "My Lord, I am sure I can save this country, and no one else can".  He had made it a condition of his joining any administration that Newcastle should be excluded from it, which proved fatal to the lengthened existence of his government. With the king unfriendly, and Newcastle, whose influence was still dominant in the Commons, estranged, it was impossible to carry on a government by the aid of public opinion alone, however emphatically that might have declared itself on his side. The historian Basil Williams has claimed that this is the first time in British history when a "man was called to supreme power by the voice of the people" rather than by the king's appointment or as the choice of Parliament.  Pitt drew up his plans for the campaigning season

Pitt–Newcastle ministry.

A coalition with Newcastle was formed in June 1757, and held power until October 1761. It brought together several various factions and was built around the partnership between Pitt and Newcastle, which a few months earlier had seemed impossible. The two men used Lord Chesterfield as an intermediary and had managed to agree a division of powers that was acceptable to both. For the past few months Britain had been virtually leaderless, although Devonshire had remained formally Prime Minister, but now Pitt and Newcastle were ready to offer stronger direction to the country's strategy.

Early challenges.

By summer 1757 the British war effort over the previous three years had broadly been a failure. Britain's attempts to take the offensive in North America had ended in disaster, Menorca had been lost, and the Duke of Cumberland's Army of Observation was retreating across Hanover following the Battle of Hastenback. In October Cumberland was forced to conclude the Convention of Klosterzeven, which would take Hanover out of the war. The French Invasion of Hanover posed a threat to Britain's ally Prussia, who they would now be able to attack

1758.

In 1758 Pitt began to put into practice a new strategy to win the Seven Years' War, which would involve tying down large numbers of French troops and resources in Germany, while Britain used its naval supremacy to launch expeditions to capture French forces around the globe. Following the Capture of Emden he ordered the dispatch of the first British troops to the European continent under the Duke of Marlborough, who joined Brunswick's army. This was a dramatic reversal of his previous position, as he had recently been strongly opposed to any such commitment.  Pitt had been lobbied by an American merchant Thomas Cumming to launch an expedition against the French trading settlements in West Africa. In April 1758 British forces captured the ill-defended fort of Saint-Louis in Senegal. The mission was so lucrative that Pitt sent out further expeditions to capture Gorée and Gambia later in the year. He also drew up plans to attack French

Annus Mirabilis.

In France a new leader, the Duc de Choiseul, had recently come to power and 1759 offered a duel between their rival strategies. Pitt intended to continue with his plan of tying down French forces in Germany while continuing the assault on France's colonies. Choiseul hoped to repel the attacks in the colonies while seeking total victory in Europe.  Pitt's war around the world was largely successful. While a British invasion of Martinique failed, they captured Guadeloupe shortly afterwards. In India, a French attempt to capture Madras was repulsed. In North America, British troops closed in on France's Canadian heartland. A British force under James Wolfe moved up the Saint Lawrence with the aim of

1760–61.

Britain completed the conquest of Canada in 1760 by capturing Montreal, which effectively brought the war to an end on mainland North America.  Pitt's power had now reached its peak, but was soon under threat. The domestic political situation was altered dramatically when George II died in October 1760. He was succeeded by his grandson, George III, who had once considered Pitt an ally but had become angered by Pitt's alliance with Newcastle and acceptance of the need for British intervention in Germany – which George was strongly opposed to. The new king successfully lobbied for his favourite Lord Bute to be given the post of Northern Secretary. Bute was inclined to support a withdrawal from Germany, and to fight the war with France largely at sea and in the colonies.  Pitt's plan

Leadership.

The "London Magazine" of 1767 offered "Pitt, Pompadour, Prussia, Providence" as the reasons for Britain's success in the Seven Years' War. Pitt's relation to all three was such as to entitle him to a large share in the credit of their deeds. He inspired trust in his chosen commanders by his indifference to rules of seniority—several of "Pitt's boys", like Keppel, captor of Gorée, were in their thirties — and by his clear orders. It was his discernment that selected Wolfe to lead the attack on Quebec, and gave him the opportunity of dying a victor on the heights of Abraham. He had personally less to do with the successes in India

Resignation.

George II died on 25 October 1760, and was succeeded by his grandson, George III. The new king was inclined to view politics in personal terms and taught to believe that "Pitt had the blackest of hearts". The new king had counsellors of his own, led by Lord Bute. Bute soon joined the cabinet as a Northern Secretary and Pitt and he were quickly in dispute over a number of issues.  In 1761 Pitt had received information from his agents about a secret Bourbon Family Compact by which the Bourbons of France and Spain bound themselves in an offensive alliance against Britain. Spain was concerned that Britain's victories over France had left them too powerful, and were a threat in the long term to Spain's own empire. Equally they may have believed that the British had become overstretched by fighting a global war and decided to try to seize British possessions such as Jamaica. A secret convention pledged that if Britain and France were still at war by 1 May 1762, Spain would enter the war on the French side.  Pitt urged that such a clear threat should be met by a pre-emptive strike against Spain's navy and her colonies—with emphasis on speed to prevent Spain bringing the annual Manila galleon safely to harbour. Bute and Newcastle refused to support such a move, as did the entire cabinet except Temple, believing it would make Britain look the aggressor against Spain potentially provoking other neutral nations to declare war on Britain. Pitt believed he had no choice but to leave a cabinet in which his advice on a vital question had been rejected and presented his resignation. Many of his cabinet colleagues secretly welcomed his departure as they believed his dominance and popularity were a threat to the Constitution. Pitt's brother-in-law George Grenville was given a major role in government, angering Pitt who felt Grenville should have resigned with him. Pitt regarded Grenville's action as a betrayal and there was hostility between them for several years.  After Pitt's resignation in October 1761, the King urged Pitt to accept a mark of royal favour. Accordingly, he obtained a pension of £3000 a year and his wife, Lady Hester Grenville was created Baroness Chatham in her own right—although Pitt refused to accept a title himself. Pitt assured the King that he would not go into direct opposition against the government. His conduct after his retirement was distinguished by a moderation and disinterestedness which, as Burke has remarked, "set a seal upon his character". The war with Spain, in which he had urged the cabinet to take the initiative, proved inevitable; but he scorned to use the occasion for "altercation and recrimination", and spoke in support of the government measures for carrying on the war.  Twenty years after he had received a similar windfall from the Marlborough legacy, Sir William Pynsent, Bt., a Somerset baronet to whom he was personally quite unknown, left him his entire estate, worth about three thousand a year, in testimony of approval of his political career.

The Chatham Ministry.

In July 1766 Rockingham was dismissed, and Pitt was entrusted by the King with the task of forming a government entirely of his own selection. His principle, "measures not men", appealed to the King whom he proposed to serve by "destroying all party distinctions". Pitt made appointments based not on connections but on merit, such as Charles Townshend to the Exchequer and Shelburne as Secretary of State, to order American affairs. Pitt chose for himself the office of Lord Privy Seal, which required his elevation to the House of Lords, and on 4 August he became Earl of Chatham in the county of Kent and Viscount Pitt of Burton Pinsent in the county of Somerset.  Pitt's decision to accept a peerage was likely influenced by his declining health and desire for a less demanding role, but the "great commoner" lost a great deal of public support. For example, in view of his probable accession to power, preparations were made in the City of London for a banquet and a general illumination to celebrate the event, but the celebration was at once countermanded when it was known that he had become Earl of Chatham.  Edmund Burke described the "chequered and speckled" administration with great humour, speaking of it as "patriots and courtiers, King's friends and republicans; Whigs

Later life.

Soon after his resignation a renewed attack of gout freed Chatham from the mental disease under which he had so long suffered. He had been nearly two years and a half in seclusion when, in July 1769, he again appeared in public at a royal levee. It was not, however, until 1770 that he resumed his seat in the House of Lords.

Falklands Crisis.

The same year when Britain and Spain became involved in the Falklands Crisis and came close to war, Pitt was a staunch advocate of taking a tough stance with Madrid and Paris (as he had been during the earlier Corsican Crisis when France had invaded Corsica) and made a number of speeches on the subject rousing public opinion. The government

War of American Independence.

Chatham sought to find a compromise on the escalating conflict with the American colonies. As he realised the gravity of the American situation, Chatham re-entered the fray, declaring that "he would be in earnest for the public" and "a scarecrow of violence to the gentler warblers of the grove". His position changed from an obsession in 1774 with the question of the authority of Parliament to a search for a formula for conciliation in 1775. He proposed the "Provisional Act" that would both maintain the ultimate authority of Parliamentary sovereignty, while meeting the colonial demands. The Lords defeated his proposal on 1 February 1775. Chatham's warnings regarding America were ignored. His brave efforts to present his case, passionate, deeply pondered, for the

Legacy.

Horace Walpole, not an uncritical admirer, wrote of Pitt:  It were ingratitude to him to say that he did not give such a reverberation to our stagnating councils, as exceedingly altered the appearance of our fortune. He warded off the evil hour that seemed approaching, he infused vigour into our arms, he taught the nation to speak again as England used to speak to foreign powers... Pitt, on entering upon administration, had found the nation at the lowest ebb in point of power and reputation... France, who meant to be feared, was feared heartily... They were willing to trust that France would be so good as to ruin us by inches. Pitt had roused us from this ignoble lethargy... The admirers of Mr Pitt extol the reverberation he gave to our councils, the despondence he banished, the spirit he infused, the conquests he made, the security he affixed to our trade and plantations, the humiliation of France, the glory of Britain carried under his administration to a pitch at which it never had arrived—and all this is exactly true.  Samuel Johnson is reported to have said that "Walpole was a minister given by the king to the people, but Pitt was a minister given by the people to the king", and the remark correctly indicates Chatham's distinctive place among English statesmen. He was the first minister whose main strength lay in the support of the nation at large as distinct from its representatives in the Commons, where his personal following was always small. He was the first to discern that public opinion, though generally slow to form and slow to act, is in the end the paramount power in the state; and he was

Family and personal life.

Pitt married Lady Hester Grenville (1720–1803), daughter of the 1st Countess

Cultural references.

There have been at least two Royal Navy ships that bore the name HMS Pitt. After British General John Forbes occupied Fort Duquesne during the French and Indian War, he ordered the site's reconstruction and named it after then-Secretary of State Pitt. He also named the settlement between the rivers "Pittsborough", which would eventually become known as Pittsburgh, Pennsylvania. Numerous other cities, towns and streets in the United States, Canada, and Australia are named after Pitt as well.

Places named after William Pitt.

United States  Canada

William Pitt, 1st Earl of Chatham, (15 November 170811 May 1778) was a British statesman of the Whig group who served as Prime Minister of Great Britain in the middle of the 18th century. Historians call him Pitt of Chatham, or William Pitt the Elder, to distinguish him from his son, William Pitt the Younger, who also was a prime minister. Pitt was also known as The Great Commoner, because of his long-standing refusal to accept a title until 1766.

William Pitt, 1. hrabě z Chathamu (15. listopad 1708 – 11. květen 1778) byl britský státník, člen strany Whigů, který získal největší slávu v době, kdy vedl Británii v sedmileté válce (spolu s Thomasem Pelham-Hollesem). Vedoucím představitelem britské vlády (ve funkci strážce královské pečeti) byl v letech 1766 až 1768. Bývá často označován jako William Pitt starší, pro odlišení od svého syna Williama Pitta mladšího.


Early life and college.

Sánchez was born in New York City to Dominican-born parents and was raised in San Diego, California. He attended University City High School and San Diego Mesa College in the city, and then went on to study psychology at the University of Southern California in 1998. Competing for University of Southern California's USC Trojans, he was a Pac-10 champion (400 m hurdles) and All-American relay champion (1600 m) in 1999.

Professional career.

Sánchez opted to represent the Dominican Republic internationally, and made his debut for that nation in the Pan American games in 1999. Between 2001 and 2004 he won 43 races in a row at 400 m hurdles, including the 2001 and 2003 World Championships. He won a share of the Golden League million dollar-jackpot in 2002 after winning all 7 races.  At the 2003 Pan American Games, Sánchez won the Dominican Republic's first gold medal at the competition and also broke the Pan American Games record in the 400 m hurdles. He was named "Track and Field News" Track & Field Athlete of the Year in 2003. Subsequently, he won the first ever Olympic gold medal for the Dominican Republic on August 28, 2004 during the 2004 Summer Olympics in Athens, Greece.  During his 43-race winning streak, from 2001 to 2004, Sánchez was known for wearing a wristband while competing. The red flashing wristband, a souvenir from the 2000 Olympics, served as a motivation for him after failing to advance to the final in Sydney. After winning the Olympic gold medal in Athens 2004, Sánchez gave the wristband to the IAAF for auction and the profits were donated to charity. In his first race after the Olympics – and his first race without the wristband – at the Van Damme Memorial meet in Brussels, Sánchez injured his leg and had to abandon the race halfway through.  In 2012, at the age of 34, Sánchez entered the 2012 Summer Olympics. He posted the fastest qualifying time, and won the final with a time of 47.63 seconds, the same as his winning time in Athens in 2004 and his fastest run for eight years. Sánchez became the oldest man to win the Olympic 400m hurdles title. He was the only Olympic medalist for the Dominican Republic until 45 minutes after his second gold medal, when Luguelín Santos picked up a silver medal in the 400 metres. For his performance in London Sanchez was awarded the Laureus World Comeback of the Year.  Sánchez announced his retirement in April 2016 at the age of 38, citing the recent birth of a son. He did not compete in the 2016 Olympics in Rio de Janeiro.

Félix Sánchez, (born August 30, 1977) is a retired Dominican-American track and field athlete. He is of Dominican descent, was born and raised in the United States, and competed for the Dominican Republic, specializing in the 400 meter hurdles. He is a two-time Olympic gold medallist, winning gold in 2004 and 2012, and was also World Champion in 2001 and 2003. Just before turning 36, he set the Masters M35 World Record with a time of 48.10. Sanchez acquired many nicknames: "Super Felix", "the Invincible", "Superman", and "the Dictator".

Félix Sánchez (* 30. srpna 1977, New York) přezdívaný též Super Felix či Dictator je sportovec, atlet z Dominikánské republiky věnující se běhu na 400 m přes překážky.


Selenography.

Aristarchus is located on an elevated rocky rise, known as the Aristarchus Plateau, in the midst of the Oceanus Procellarum, a large expanse of lunar mare. This is a tilted crustal block, about 200 km across, that rises to a maximum elevation of 2 km above the mare in the southeastern section. Aristarchus is just to the east of the crater Herodotus and the Vallis Schröteri, and south of a system of narrow sinuous rilles named Rimae Aristarchus.  Aristarchus is bright because it is a young formation, approximately 450 million years old, and the solar wind has not yet had time to darken the excavated material by the process of space weathering. The impact occurred following the creation of the ray crater Copernicus, but before the appearance of Tycho. Due to its prominent rays, Aristarchus is mapped as part of the Copernican System.  The brightest feature of this crater is the steep central peak. Sections of the interior floor appear relatively level, but Lunar Orbiter photographs reveal the surface is covered in many small hills, streaky gouges, and some minor fractures. The crater has a terraced outer wall, roughly or polygonal in shape, and covered in a bright blanket of ejecta. These spread out into bright rays to the south and south-east, suggesting that Aristarchus was most likely formed by an oblique impact from the northeast, and their composition includes material from both the Aristarchus plateau and the lunar mare.  In November 2011, the Lunar Reconnaissance Orbiter passed over the crater, which spans almost 25 miles (40 kilometers) and sinks more than 2 miles (3.5 kilometers) deep. "The Aristarchus plateau is one of the most geologically diverse places on the moon: a mysterious raised flat plateau, a giant rille carved by enormous outpourings of lava, fields of explosive volcanic ash, and all surrounded by massive flood basalts," said Mark Robinson, principal investigator of the Lunar Reconnaissance Orbiter Camera at Arizona State University. NASA released photos of the crater on December 25, 2011.

Remote sensing.

In 1911, Professor Robert W. Wood used ultraviolet photography to take images of the crater area. He discovered the plateau had an anomalous appearance in the ultraviolet, and an area to the north appeared to give indications of a sulfur deposit. This colorful area is sometimes referred to as "Wood's Spot", an alternate name for the Aristarchus Plateau. Spectra taken of this crater during the Clementine mission were used to perform mineral mapping. The data indicated that the central peak is a type of rock called anorthosite, which is a slow-cooling form of igneous rock composed of plagioclase feldspar. By contrast the outer wall is troctolite, a rock composed of equal parts plagioclase and olivine.  The Aristarchus region was part of a Hubble Space Telescope study in 2005 that was investigating the presence of oxygen-rich glassy soils in the form of the mineral ilmenite. Baseline measurements were made of the Apollo 15 and Apollo 17 landing sites, where the chemistry is known, and these were compared to Aristarchus. The Hubble Advanced Camera for Surveys was used to photograph the crater in visual and ultraviolet light. The crater was determined to have especially rich concentrations of ilmenite, a titanium oxide mineral that could potentially be used in the future by a lunar settlement for extracting oxygen.

Transient lunar phenomena.

The region of the Aristarchus plateau has been the site of many reported transient lunar phenomena, with a total of 122 such reports by 2007; the highest recorded for any lunar feature. Such events include temporary obscurations and colorations of the surface, and catalogues of these show that more than one-third of the most reliable spottings come from this locale. In 1971 when Apollo 15 passed 110 kilometers above the Aristarchus plateau, a significant rise in alpha particles was detected. These particles are believed to be caused by the decay of radon-222, a radioactive gas with a half-life of only 3.8 days. The Lunar Prospector mission later confirmed radon-222 emissions from this crater. These observations could be explained by either the slow and visually imperceptible diffusion of gas to the surface, or by discrete explosive events.

Names.

Aristarchus is named after the Greek astronomer Aristarchus of Samos. Like many of the craters on the Moon's near side, it was given its name by Giovanni Riccioli, whose 1651 nomenclature system became standardized in 1935. Earlier lunar cartographers had given the feature different names. Michael van Langren's 1645 map calls it "Balthasaris Hispa. Pri." after Balthazar Charles, then the heir apparent to the kingdoms of Spain. And Johannes Hevelius called it "Mons Porphyrites" after the mountains near Olbia, Egypt. A particular region of very low ultraviolet albedo is called Wood's Spot after its discoverer, Robert W. Wood.

Satellite craters.

Surrounding Aristarchus are several smaller craters, many of which are probably secondary craters. Secondary craters form when large blocks ejected from the primary crater reimpact the surface at high velocities. By convention these features are identified on lunar maps by placing a letter on the side of the crater midpoint that is closest to the primary crater.  The following craters have been renamed by the IAU.

Aristarchus, named after the Greek astronomer Aristarchus of Samos, is a prominent lunar impact crater that lies in the northwest part of the Moon's near side. It is considered the brightest of the large formations on the lunar surface, with an albedo nearly double that of most lunar features. The feature is bright enough to be visible to the naked eye, and displays unusually bright features when viewed through a large telescope. It is also readily identified when most of the lunar surface is illuminated by earthshine. The crater is deeper than the Grand Canyon.

Aristarchus je impaktní kráter nacházející se na pevninském výběžku uprostřed měsíčního moře Oceanus Procellarum (Oceán bouří) na přivrácené straně Měsíce. Jeho stáří se odhaduje na 450 milionů let. Má průměr 40 km a je hluboký 3,7 km. Nazván byl podle starořeckého astronoma Aristarcha ze Samu, který položil první základy pokusům o geometrické změření vzdáleností Slunce a Měsíce od Země. V blízkosti východo-jihovýchodním směrem se nachází lávou zatopený kráter Herodotus, od něhož se vine měsíční údolí Vallis Schröteri.


Structure.

The ossicles are, in order from the eardrum to the inner ear (from superficial to deep): the malleus, incus, and stapes, terms that in Latin are translated as "the hammer, anvil, and stirrup".

Development.

Studies have shown that ear bones in mammal embryos are attached to the dentary, which is part of the jaw. These are ossified portions of cartilage—called Meckel's cartilage—that are attached to the jaw. As the embryo develops, the cartilage hardens to form bone. Later in development, the bone structure breaks loose from the jaw and migrates to the inner ear area. The structure is known as the middle ear, and is made up of the stapes, incus, malleus, and tympanic membrane. These correspond to the columella, quadrate, articular, and angular structures in the amphibian, bird or reptile jaw.

Function.

As sound waves vibrate the tympanic membrane (eardrum), it in turn moves the nearest ossicle, the malleus, to which it is attached. The malleus then transmits the vibrations, via the incus, to the stapes, and so ultimately to the membrane of the fenestra ovalis (oval window), the opening to the vestibule of the inner ear.  Sound traveling through the air is mostly reflected when it comes into contact with a liquid medium; only about 1/30 of the sound energy moving through the air would be transferred into the liquid. This is observed from the abrupt cessation of sound that occurs when the head is submerged underwater. This is because the relative incompressibility of a liquid presents resistance to the force of the sound waves traveling through the air. The ossicles give the eardrum a mechanical advantage via lever action and a reduction in the area of force distribution; the resulting vibrations are stronger but move less far. This allows more efficient coupling than if the sound waves were transmitted directly from the outer ear to the oval window. This reduction in the area of force application allows a large enough increase in pressure to transfer most of the sound energy into the liquid. The increased pressure will compress the fluid found in the cochlea and transmit the stimulus. Thus, the lever action of the ossicles changes the vibrations so as to improve the transfer and reception of sound, and is a form of impedance matching.  However, the extent of the movements of the ossicles is controlled (and constricted) by two muscles attached to them (the "tensor tympani" and the "stapedius"). It is believed that these muscles can contract to dampen the vibration of the ossicles, in order to protect the inner ear from excessively loud noise (theory 1) and that they give better frequency resolution at higher frequencies by reducing the transmission of low frequencies (theory 2) (see acoustic reflex). These muscles are more highly developed in bats and serve to block outgoing cries of the bats during echolocation (SONAR).

Clinical relevance.

Occasionally the joints between the ossicles become rigid. One condition, otosclerosis, results in the fusing of the stapes to the oval window. This reduces hearing and may be treated surgically.

History.

There is some doubt as to the discoverers of the auditory ossicles and several anatomists from the early 16th century have the discovery attributed to them with the two earliest being Alessandro Achillini and Jacopo Berengario da Carpi. Several sources, including Eustachi and Casseri, attribute the discovery of the malleus and incus to the anatomist and philosopher Achillini. The first written description of the malleus and incus was by Berengario da Carpi in his "Commentaria super anatomia Mundini" (1521), although he only briefly described two bones and noted their theoretical association with the transmission of sound. Niccolo Massa's "Liber introductorius anatomiae" described the same bones in slightly more detail and likened them both to little hammers. A much more detailed description of the first two ossicles followed in Andreas Vesalius' "De humani corporis fabrica" in which he devoted a chapter to them. Vesalius was the first to compare the second element of the ossicles to an anvil although he offered the molar as an alternative comparison for its shape. The first published description of the stapes came in Pedro Jimeno's "Dialogus de re medica" (1549) although it had been previously described in public lectures by Giovanni Filippo Ingrassia at the University of Naples as early as 1546.  The term "ossicle" derives from, a diminutive of "bone" (; genitive ). The malleus gets its name from Latin "malleus", meaning "hammer", the incus gets its name from Latin "incus" meaning "anvil" from incudere meaning "to forge with a hammer", and the stapes gets its name from Modern Latin "stirrup", probably an alteration of Late Latin "stapia" related to stare "to stand" and pedem, an accusative of pes "foot", so called because the bone is shaped like a stirrup – this was an invented Modern Latin word for "stirrup", for which there was no classical Latin word, as the ancients did not use stirrups.

The ossicles (also called auditory ossicles) are three bones in either middle ear that are among the smallest bones in the human body. They serve to transmit sounds from the air to the fluid-filled labyrinth (cochlea). The absence of the auditory ossicles would constitute a moderate-to-severe hearing loss. The term "ossicle" literally means "tiny bone". Though the term may refer to any small bone throughout the body, it typically refers to the malleus, incus, and stapes (hammer, anvil, and stirrup) of the middle ear.

Sluchové kůstky (: "ossicula auditus") kůstky středního ucha či ušní kůstky jsou tři kůstky – kladívko ("malleus"), kovadlinka ("incus") a třmínek ("stapes") – uložené v dutině středního ucha v bubínkové dutině savců ("cavum tympani") a napojené na bubínek. Kladívko a kovadlinka patří k mandibulárnímu, třmínek k hyoidnímu oblouku. Řetěz těchto kůstek přenáší zvuk od bubínku do vnitřního ucha – ploténka třmínku se dotýká oválného okénka ve vnitřním uchu.