Early life.

Frederica's mother died on 22 May 1782 after giving birth to her tenth child. Two years later (28 September 1784), her father remarried the younger sister of his deceased wife, Princess Charlotte of Hesse-Darmstadt, but this union ended just one year later, when Charlotte died of complications resulting from childbirth on 12 December 1785.  The twice-widowed Duke Charles considered himself unable to give his daughters proper rearing and education, so he sent Frederica and her elder sisters Charlotte, Therese and Louise to their maternal grandmother, Princess Maria Louise of Hesse-Darmstadt. Princess Maria Louise's choice of a Swiss teacher for the girls, Salomé de Gélieu, proved to be a good one. Some time later, Duke Charles also sent his two surviving sons, the Hereditary Grand Duke George and Charles, to be raised by their grandmother.

First marriage.

Frederica's parents were anxious to arrange advantageous marriages for all their daughters, and used family connections to bring this about. Queen Frederika Louisa of Hesse-Darmstadt, wife of King Frederick William II, was a first cousin of Frederica's mother. Frederica's parents broached with the Prussian royal family the idea of marriage between their children, and the Prussians were not averse. On 14 March 1793, the Princesses of Mecklenburg-Strelitz "coincidentally" met the Prussian King Frederick William II at the Prussian Theatre in Frankfurt-am-Main. He was immediately captivated by the grace and charm of both sisters, Frederica and Louise. The pending marriage negotiations received traction, and within weeks, the matter was settled: Frederica's elder sister Louise would marry Crown Prince Frederick William, and Frederica would marry his younger brother Prince Louis.  The double engagement was celebrated in Darmstadt on 24 April 1793, only a few weeks after the sister fortuitously met their future father-in-law at the theatre. On December 24, Louise and Crown Prince Frederick William were married in the Royal Palace of Berlin; two days later, on 26 December, Frederica and Prince Louis were also married at the same venue.  Unlike her sister, Frederica did not enjoy a happy marriage. Although her husband died only three years after the wedding, Louis was said to have preferred the company of his mistresses and completely neglected his wife, or at least, that is her version; in response, she allegedly began an affair with her husband's uncle Prince Louis Ferdinand. Despite her husband's alleged neglect, Fredrica did bear him three children in as many years: Frederick in 1794; a short-lived son, Charles, in 1795; and a daughter, Frederica, in 1796.  In 1795, King Frederick William II appointed Louis as Chief of the Dragoons Regiment No.1, which was stationed in Schwedt. One year later, on 23 December 1796, Prince Louis died of diphtheria. It was three years almost to the day since their wedding. At this time, his youngest child, Frederica, was less than three months old, and his eldest son was hardly two years old. After Louis's death, his father provided Frederica with a suitable residence near Berlin, and a sufficient income, and she moved with her three children to Schönhausen Palace near Berlin.  In 1797, Frederica and her cousin Prince Adolphus, Duke of Cambridge, seventh son of King George III of Great Britain by his wife Queen Charlotte (Frederica's paternal aunt), became unofficially engaged. The Duke of Cambridge asked the consent of his father to the marriage. The King did not refuse his consent but asked his son to wait until the ongoing war with France was over. The relationship eventually ended, with rumors circulating that either Adolphus had offered to release Frederica from the engagement, or - as Queen Charlotte believed - Frederica had jilted him for another man.

Second marriage.

In 1798 Frederica became pregnant. The father was Prince Frederick William of Solms-Braunfels. The prince recognized his paternity and requested her hand in marriage, a proposal that was quickly granted in order to avoid scandal. On 10 December of that year, the couple was married in Berlin and immediately moved to Ansbach. Two months later, in February 1799, Frederica gave birth to a daughter who only lived eight months. Prince Frederick William, disappointed and embittered, resumed his old dissipated lifestyle and became an alcoholic. In 1805 he resigned his military posts for "health reasons". Frederica had to maintain her family with her own resources after her brother-in-law, King Frederick William III of Prussia, refused to restore her annual pension as a dowager princess of Prussia. Frederica's older brother-in-law and head of the family, William Christian, Prince of Solms-Braunfels, advised her to get a divorce, with his full approval. She and her husband nonetheless refused.

Third marriage.

In May 1813, during a visit to his uncle Duke Charles in Neustrelitz, Prince Ernest Augustus, Duke of Cumberland, the fifth son of King George III of Great Britain, met and fell in love with Frederica. Duke Charles made it clear to his daughter that her separation from the Prince of Solms-Braunfels was absolutely logical, and that he saw a marriage with an English prince as a great opportunity for her. During the next months Frederica considered the intentions of Ernest Augustus and the possible effects on her own situation. When, after the victory of the allies in the Battle of Leipzig, Ernest Augustus spent some days in Neustrelitz, he was greeted enthusiastically. Some time later Frederica asked the Prussian king for approval for her divorce from Prince Frederick William of Solms-Braunfels. All parties agreed, including the Prince of Solms-Braunfels, but Frederick William's sudden death on 13 April 1814 precluded the need for a divorce. The prince's demise was considered by some as a little too convenient, and some suspected that Frederica had poisoned him. In August, the engagement with Ernest Augustus was officially announced. After the British Prince Regent gave his consent to the wedding, Frederica and Ernest Augustus were married on 29 May 1815 at the parish church of Neustrelitz. Some time later, the couple traveled to Great Britain and married again on 29 August 1815 at Carlton House, London.  Queen Charlotte bitterly opposed the marriage, even though her future daughter-in-law was also her niece. She refused to attend the wedding and advised her son to live outside England with his wife. Frederica never obtained the favor of her aunt/mother-in-law, who died unreconciled with her in 1818. During her marriage to Ernest Augustus she gave birth three times, but only a son survived, who would eventually become King George V of Hanover.

Queen of Hanover.

On 20 June 1837 King William IV of the United Kingdom and Hanover died without issue. His heir was Princess Victoria, only daughter of Prince Edward, Duke of Kent, but because Hanover had been ruled under semi-Salic Law since the times of the Holy Roman Empire, she could not inherit the Hanoverian throne. The next male descendant of the late king was the Duke of Cumberland, Frederica's husband, who then became King of Hanover, with Frederica as his Queen consort.  After a short illness, Queen Frederica of Hanover died in 1841 at Hanover. The Court master builder Georg Ludwig Friedrich Laves was instructed by the King to build a mausoleum for his wife and himself in the garden of the chapel at Herrenhausen Palace. He also gave royal orders for the transformation of a central square near the "Leineschloss" and renamed it "Friederikenplatz" in her honor.

Frederica of Mecklenburg-Strelitz ("Friederike Louise Caroline Sophie Charlotte Alexandrine") (3 March 1778 – 29 June 1841) was a German princess who became, by marriage, princess of Prussia, princess of Solms-Braunfels, Duchess of Cumberland in Britain and Queen of Hanover (in Germany) as the consort of Ernest Augustus, King of Hanover (the fifth son and eighth child of King George III).


Historical accounts.

Siege of Mount Badon.

The earliest mention of the Battle of Badon is Gildas' "De Excidio et Conquestu Britanniae" ("On the Ruin and Conquest of Britain"), written in the early to mid-6th century. In it, the Anglo-Saxons are said to have "dipped [their] red and savage tongue in the western ocean" before Ambrosius Aurelianus organized a British resistance with the survivors of the initial Saxon onslaught. Gildas describes the period that followed Ambrosius' initial success:  "De Excidio Britanniae" describes the battle as such an "unexpected recovery of the [island]" that it caused kings, nobles, priests, and commoners to "live orderly according to their several vocations" before the long peace degenerated into civil wars and the iniquity of Maelgwn Gwynedd.  The battle is next mentioned in an 8th-century text of Bede's "Ecclesiastical History of the English People". It describes the "siege of Mount Badon, when they made no small slaughter of those invaders," as occurring 44 years after the first Anglo-Saxon settlement of Britain. Since Bede places that arrival during or just after the joint reign of Marcian and Valentinian III in 449456, he must have considered Badon to have taken place between 493 and 500. Bede then puts off discussion of the battle "But more of this hereafter" only to seemingly never return to it. Bede does later include an extended account of Saint Germanus of Auxerre's victory over the Saxons and Picts in a mountain valley, which he credits with curbing the threat of invasion for a generation. However, as the victory is described as having been accomplished bloodlessly, it was presumably a different occasion from Badon. Accepted at face value, St. Germanus' involvement would also place the battle around 430, although Bede's chronology shows no knowledge of this.

Battle of Badon.

The earliest surviving text mentioning Arthur at the battle is the early 9th-century "Historia Brittonum", in which the soldier (Latin "mīles") Arthur is identified as the leader of the victorious British force at Badon:  "The twelfth battle was on Mount Badon in which there fell in one day 960 men from one charge by Arthur; and no one struck them down except Arthur himself".  The Battle of Badon is next mentioned in the "Annales Cambriae" ("Annals of Wales"), assumed to have been written during the mid- to late-10th century. The entry states: That Arthur had gone unmentioned in the source closest to his own time, Gildas, was noticed at least as early as the 12th-century hagiography which claims that Gildas had praised Arthur extensively but then excised him completely after Arthur killed the saint's brother, Hueil mab Caw. Modern writers have suggested the details of the battle were so well known that Gildas could have expected his audience to be familiar with them.  Geoffrey of Monmouth's c. 1136 "Historia Regum Britanniae" was massively popular and survives in many copies from soon after its composition. Going into (and fabricating) much greater detail, Geoffrey closely identifies Badon with Bath, including having Merlin foretell that Badon's baths would lose their hot water and turn poisonous. He also mixes in aspects of other accounts: the battle begins as a Saxon siege and then becomes a normal engagement once Arthur's men arrive; Arthur bears the image of the Virgin both on his shield and shoulder. Arthur charges, but kills a mere 470, ten more than the number of Britons ambushed by Hengist near Salisbury. Elements of the Welsh legends are also added: in addition to the shield "Pridwen", Arthur gains his sword "Caliburnus" and his spear, "Ron". Geoffrey also makes the defence of the city from the Saxon sneak attack a holy cause, having Dubricius offer absolution of all sins for those who fall in battle.

Scholarship.

McCarthy and Ó Cróinín propose that Gildas' 44 years and one month is not a reference to the simple chronology but a position within the 84-year Easter cycle used for computus at the time by the Britons and the Irish church. The tables in question begin in January 438, which would place their revised date of the battle in February 482.  Hirst, Ashe and Wood argue for the site of Liddington Castle on the hill above Badbury (Old English: "Baddan byrig") in Wiltshire. This site commands The Ridgeway, which connects the River Thames with the River Avon and River Severn beyond. The Burkitts argue for the site of Bath on the basis of evidence of the Welsh Annals, as well as archaeological, linguistic and place name evidence.

Second Badon.

The A Text of the "Annales Cambriae" includes the entry: "The first celebration of Easter among the Saxons. The second battle of Badon. Morgan dies." The date for this action is given by Phillimore as 665, but the Saxons' first Easter is placed by the B Text in its entry 634 years after the birth of Christ and "the second Badon" is not mentioned.

Local lore.

Apart from the professional scholarship, various communities throughout Wales and England carry on local traditions maintaining that their area was the site of the battle: these include Bathampton Down, which has evidence of Dark Age camps, circumvallation entrenchments, and artillery mounds surrounding it; Badbury Rings at the Kingston Lacy House in Dorset; and Bowden Hill in Wiltshire.

The Battle of Badon also known as the Battle of Mons Badonicus (, "Blockade/siege of the Badonic Hill"; "Bellum in monte Badonis", "Battle on Badon Hill"; "Bellum Badonis", "Battle of Badon"; Old Welsh: "Badon"; Middle Welsh: "Gweith Vadon", "Battle of Badon";, "Battle of Badon Mount/Hill") was a battle purportedly fought between Celtic Britons and Anglo-Saxons in Britain in the late 5th or early 6th century. It was credited as a major victory for the Britons, stopping the encroachment of the Anglo-Saxon kingdoms for a period.


Occurrence and production.

Xylenes are an important petrochemical produced by catalytic reforming and also by coal carbonisation in the manufacture of coke fuel. They also occur in crude oil in concentrations of about 0.5–1%, depending on the source. Small quantities occur in gasoline and aircraft fuels.  Xylenes are produced mainly as part of the BTX aromatics (benzene, toluene, and xylenes) extracted from the product of catalytic reforming known as reformate. The xylene mixture is a slightly greasy, colorless liquid commonly encountered as a solvent.  Several million tons are produced annually. In 2011, a global consortium began construction of one of the world's largest xylene plants in Singapore.

History.

Xylene was first isolated and named in 1850 by the French chemist Auguste Cahours (1813–1891), having been discovered as a constituent of wood tar.

Isomers.

Xylene exists in three isomeric forms. The isomers can be distinguished by the designations "ortho"- ("o"-), "meta"- ("m"-) and "para"- ("p"-), which specify to which carbon atoms (of the benzene ring) the two methyl groups are attached. By counting the carbon atoms around the ring starting from one of the ring carbons bonded to a methyl group, and counting towards the second methyl group, the "o"-isomer has the IUPAC name of 1,2-dimethylbenzene, the "m"-isomer is 1,3-dimethylbenzene and the "p"-isomer is 1,4-dimethylbenzene. Of the three isomers, the "p"-isomer is the most industrially sought after since it can be oxidized to terephthalic acid.

Industrial production.

Xylenes are produced by the methylation of toluene and benzene. Commercial or laboratory grade xylene produced usually contains about 40-65% of "m"-xylene and up to 20% each of "o"-xylene, "p"-xylene and ethylbenzene. The ratio of isomers can be shifted to favor the highly valued "p"-xylene via the patented UOP-"Isomar" process or by transalkylation of xylene with itself or trimethylbenzene. These conversions are catalyzed by zeolites.  ZSM-5 is used to facilitate some isomerization reactions leading to mass production of modern plastics.

Properties.

The chemical and physical properties of xylene differ according to the respective isomers. The melting point ranges from ("m"-xylene) to ("p"-xylene)—as usual, the para isomer's melting point is much higher because it packs more readily in the crystal structure. The boiling point for each isomer is around. The density of each isomer is around 0.87 g/mL (7.26 lb/U.S. gallon or 8.72 lb/imp gallon) and thus is less dense than water. Xylene in air can be smelled at concentrations as low as 0.08 to 3.7 ppm (parts of xylene per million parts of air) and can be tasted in water at 0.53 to 1.8 ppm.  Xylenes form azeotropes with water and a variety of alcohols. With water the azeotrope consists of 60% xylenes and boils at 94.5 °C. As with many alkylbenzene compounds, xylenes form complexes with various halocarbons. The complexes of different isomers often have dramatically different properties from each other.

Applications.

Terephthalic acid and related derivatives.

"p"-Xylene is the principal precursor to terephthalic acid and dimethyl terephthalate, both monomers used in the production of polyethylene terephthalate (PET) plastic bottles and polyester clothing. 98% of "p"-xylene production, and half of all xylenes produced is consumed in this manner. "o"-Xylene is an important precursor to phthalic anhydride. The demand for isophthalic acid is relatively modest so "m"-xylene is rarely sought (and hence the utility of its conversion to the "o"- and "p"-isomers).

Solvent applications and industrial purposes.

Xylene is used as a solvent. In this application, with a mixture of isomers, it is often referred to as xylenes or xylol. Solvent xylene often contains a small percentage of ethylbenzene. Like the individual isomers, the mixture is colorless, sweet-smelling, and highly flammable. Areas of application include the printing, rubber, and leather industries. It is a common component of ink, rubber, and adhesives. In thinning paints and varnishes, it can be substituted for toluene where slower drying is desired, and thus is used by conservators of art objects in solubility testing. Similarly it is a cleaning agent, e.g., for steel, silicon wafers, and integrated circuits. In dentistry, xylene can be used to dissolve gutta percha, a material used for endodontics (root canal treatments). In the petroleum industry, xylene is also a frequent component of paraffin solvents, used when the tubing becomes clogged with paraffin wax. For similar reasons, it is often the active ingredient in commercial products for ear wax (cerumen) removal.(1)

Laboratory use.

Xylene is used in the laboratory to make baths with dry ice to cool reaction vessels, and as a solvent to remove synthetic immersion oil from the microscope objective in light microscopy. In histology, xylene is the most widely used clearing agent. Xylene is used to remove paraffin from dried microscope slides prior to staining. After staining, microscope slides are put in xylene prior to mounting with a coverslip.

Precursor to other compounds.

Although conversion to terephthalic acid is the dominant chemical conversion, xylenes are precursors to other chemical compounds. For instance chlorination of both methyl groups gives the corresponding xylene dichlorides (bis(chloromethyl)benzenes) whilst mono-bromination yields xylyl bromide, a tear gas agent used in World War I.

Health and safety.

Xylene is flammable but of modest acute toxicity, with ranges from 200 to 5000 mg/kg for animals. Oral for rats is 4300 mg/kg. The principal mechanism of detoxification is oxidation to methylbenzoic acid and hydroxylation to hydroxylene.  The main effect of inhaling xylene vapor is depression of the central nervous system (CNS), with symptoms such as headache, dizziness, nausea and vomiting. At an exposure of 100 ppm, one may experience nausea or a headache. At an exposure between 200 and 500 ppm, symptoms can include feeling "high", dizziness, weakness, irritability, vomiting, and slowed reaction time.  The side effects of exposure to low concentrations of xylene () are reversible and do not cause permanent damage. Long-term exposure may lead to headaches, irritability, depression, insomnia, agitation, extreme tiredness, tremors, hearing loss, impaired concentration and short-term memory loss. A condition called chronic solvent-induced encephalopathy, commonly known as "organic solvent syndrome" has been associated with xylene exposure. There is very little information available that isolates xylene from other solvent exposures in the examination of these effects.  Hearing disorders have been also linked to xylene exposure, both from studies with experimental animals, as well as clinical studies.  Xylene is also a skin irritant and strips the skin of its oils, making it more permeable to other chemicals. The use of impervious gloves and masks, along with respirators where appropriate, is recommended to avoid occupational health issues from xylene exposure.  Xylenes are metabolized to methylhippuric acids. The presence of methylhippuric acid can be used as a biomarker to determine exposure to xylene.

Xylene (from Greek ξύλο, "xylo", "wood"), xylol or dimethylbenzene is any one of three isomers of dimethylbenzene, or a combination thereof. With the formula (CH)CH, each of the three compounds has a central benzene ring with two methyl groups attached at substituents. They are all colorless, flammable liquids, some of which are of great industrial value. The mixture is referred to as both xylene and, more precisely, xylenes.


Biography.

Dietrich fell out with his brother, Albrecht the Proud as his mother persuaded his father to change the succession so that Dietrich was given the Margraviate of Meißen and Albrecht (although the older son) the Margraviate of Weißenfels. Albrecht took his father prisoner to try to make him return the succession to the way it had been. After Otto obtained his release by order of the emperor Frederick I, he had only just renewed the war when he died in 1190. Albrecht took back the Meißen margraviate from his brother. Dietrich attempted to regain the margraviate, supported by Landgraf Hermann I of Thuringia, whose daughter he was married to. In 1195, however, he left on a pilgrimage to Palestine.

Albrecht's Death.

After Albrecht's death in 1195, leaving no children, Meissen, with its rich mines, was seized by the emperor Henry VI as a vacant fief of the empire. Dietrich finally came into possession of his inheritance two years later on Henry's death.  At the time of the struggle between the two rival kings Philip of Swabia and Otto IV, Holy Roman Emperor, Phillip gave Dietrich the tenure of the march of Meißen again. After that time, Dietrich was on Phillip's side and remained true to the Staufer even after Phillip was murdered in 1208.  Dietrich became caught up in dangerous disagreements with the city of Leipzig and the Meißen nobility. After a fruitless siege of Leipzig, in 1217 he agreed to a settlement but then took over the city by trickery, had the city walls taken down and built three castles of his own within the city, full of his own men.

Death.

Margrave Dietrich died on 18 February 1221, possibly poisoned by his doctor, instigated into doing so by the people of Leipzig and the dissatisfied nobility. He left behind a widow, Jutta of Thuringia, daughter of Hermann I, Landgrave of Thuringia. Some of his children had already died.

Marriages and issue.

Children from his marriage to Jutta of Thuringia, daughter of Hermann I, Landgrave of Thuringia:  Children from extramarital liaisons:

Theodoric I (11 March 1162 – 18 February 1221), called the Oppressed ("Dietrich der Bedrängte"), was the Margrave of Meissen from 1198 until his death. He was the second son of Otto II, Margrave of Meissen and Hedwig of Brandenburg.


Origin and uses.

Square waves are universally encountered in digital switching circuits and are naturally generated by binary (two-level) logic devices. Square waves are typically generated by metal–oxide–semiconductor field-effect transistor (MOSFET) devices due to their rapid on–off electronic switching behavior, in contrast to BJT transistors which slowly generate signals more closely resembling sine waves rather than square waves.  Square waves are used as timing references or "clock signals", because their fast transitions are suitable for triggering synchronous logic circuits at precisely determined intervals. However, as the frequency-domain graph shows, square waves contain a wide range of harmonics; these can generate electromagnetic radiation or pulses of current that interfere with other nearby circuits, causing noise or errors. To avoid this problem in very sensitive circuits such as precision analog-to-digital converters, sine waves are used instead of square waves as timing references.  In musical terms, they are often described as sounding hollow, and are therefore used as the basis for wind instrument sounds created using subtractive synthesis. Additionally, the distortion effect used on electric guitars clips the outermost regions of the waveform, causing it to increasingly resemble a square wave as more distortion is applied.  Simple two-level Rademacher functions are square waves.

Definitions.

The square wave in mathematics has many definitions, which are equivalent except at the discontinuities:  It can be defined as simply the sign function of a sinusoid:  which will be 1 when the sinusoid is positive, −1 when the sinusoid is negative, and 0 at the discontinuities. Here, "T" is the period of the square wave and "f" is its frequency, which are related by the equation "f" = 1/"T".  A square wave can also be defined with respect to the Heaviside step function "u"("t") or the rectangular function Π("t"):  A square wave can also be generated using the floor function directly:  and indirectly:

Fourier analysis.

Using Fourier expansion with cycle frequency over time, an ideal square wave with an amplitude of 1 can be represented as an infinite sum of sinusoidal waves:  The ideal square wave contains only components of odd-integer harmonic frequencies (of the form ). Sawtooth waves and real-world signals contain all integer harmonics.  A curiosity of the convergence of the Fourier series representation of the square wave is the Gibbs phenomenon. Ringing artifacts in non-ideal square waves can be shown to be related to this phenomenon. The Gibbs phenomenon can be prevented by the use of σ-approximation, which uses the Lanczos sigma factors to help the sequence converge more smoothly.  An ideal mathematical square wave changes between the high and the low state instantaneously, and without under- or over-shooting. This is impossible to achieve in physical systems, as it would require infinite bandwidth.  Square waves in physical systems have only finite bandwidth and often exhibit ringing effects similar to those of the Gibbs phenomenon or ripple effects similar to those of the σ-approximation.  For a reasonable approximation to the square-wave shape, at least the fundamental and third harmonic need to be present, with the fifth harmonic being desirable. These bandwidth requirements are important in digital electronics, where finite-bandwidth analog approximations to square-wave-like waveforms are used. (The ringing transients are an important electronic consideration here, as they may go beyond the electrical rating limits of a circuit or cause a badly positioned threshold to be crossed multiple times.)

Characteristics of imperfect square waves.

As already mentioned, an ideal square wave has instantaneous transitions between the high and low levels. In practice, this is never achieved because of physical limitations of the system that generates the waveform. The times taken for the signal to rise from the low level to the high level and back again are called the "rise time" and the "fall time" respectively.  If the system is overdamped, then the waveform may never actually reach the theoretical high and low levels, and if the system is underdamped, it will oscillate about the high and low levels before settling down. In these cases, the rise and fall times are measured between specified intermediate levels, such as 5% and 95%, or 10% and 90%. The bandwidth of a system is related to the transition times of the waveform; there are formulas allowing one to be determined approximately from the other.

A square wave is a non-sinusoidal periodic waveform in which the amplitude alternates at a steady frequency between fixed minimum and maximum values, with the same duration at minimum and maximum. Although not realizable in physical systems, the transition between minimum and maximum is instantaneous for an ideal square wave.


Context.

The Holy Roman Emperor, with his Saxon and Roman Catholic allies, was fighting for the control of northern Germany against the Swedes and an alliance of Protestant princes opposed to Habsburg hegemony. The Swedes were also allied to the French, but the latter played no part in the battle. The Imperial main army was screening the Swedish army behind the Elbe while a smaller army under General Klitzing was overrunning Brandenburg. Field Marshal Johan Banér commanding the main Swedish army was joined by Field Marshal Alexander Leslie commanding the Army of the Weser which comprised German, Scottish and (at least one) English regiments. Together they crossed the Elbe with a surprise march and met their opponents in the forested hilly landscape slightly south of Wittstock.  The Imperial army was larger in strength than the Swedish army, but at least one-third of it was composed of Saxon units of questionable quality. The Swedish artillery was considerably stronger, leading the Imperial commanders to maintain a largely defensive position on the hill tops.

The battle.

The Imperial forces decided to wait for the Swedes on a range of sandy hills, the Scharfenberg. A part of the Imperial front was further defended with six ditches and a wall of linked wagons. Their commanders waited for some time for the Swedish troops to appear on the open fields to their front. Instead, the Swedish army was turning the Imperial left flank, moving behind the cover of a series of linked hills. The Imperial troops were forced to redeploy their lines to set up a new front.  The battle was begun by small forces detached in detail to secure the hills. The Swedes, under Banér had problems moving up reinforcements through marshy ground, but battle was eventually joined along a wide front.  Banér and Leslie had detached one-fourth of the army under Lieutenant-General James King and Major-General Torsten Stålhandske to take a long detour around the Imperial right flank. They found the traverse difficult and slow, leading Banér's troops to take heavy casualties and begin to retreat. Alexander Leslie moved five of his regiments to his relief taking heavy casualties in the process with the Scottish and English regiments being particularly badly mauled. Nonetheless they were able to relieve Banér in time for King's cavalry to finally outflank the Imperial troops causing a rout. With Major General Vitzthum in the reserve refusing to engage the Imperialists, his role was taken by Major-General John Ruthven (Leslie's son-in-law) who had been so deployed for just such an emergency. Now attacked on two fronts and with the reserve brigades engaged, the Imperial forces, having lost all their artillery, retreated under the cover of dusk in full rout.

Conclusion.

In the accounts of the battle preserved in National Archives of Sweden, Johan Banér accredits the victory to Field Marshal Leslie. Leslie, in his personal correspondence to the Swedish Chancellor, Axel Oxenstierna, was clearly horrified at the losses sustained by his army and implies that there had been disagreement about the wisdom of Banér's tactics before the battle. A third report, by James King conforms with Leslie's, but also contains additional information. All three have been transcribed, translated and published in English. Nevertheless, Wittstock was a resounding victory for the Swedish forces and corrected any delusions harboured by the Imperialists that they were a spent force after the earlier battle of Nördlingen.

The Battle of Wittstock took place during the Thirty Years' War (1618-1648). It was fought on 24 September (Julian calendar) or 4 October (Gregorian calendar) 1636. A Swedish-allied army commanded jointly by Johan Banér and Alexander Leslie, later 1st Earl of Leven decisively defeated a combined Imperial-Saxon army, led by Count Melchior von Hatzfeld and the Saxon Elector John George I.


Biography.

Teti had several wives:  Teti is known to have had several children. He was the father of at least three sons and probably ten daughters. Of the sons, two are well attested, a third one is likely:  According to N. Kanawati, Teti had at least nine daughters, by a number of wives, and the fact that they were named after his mother, Sesheshet, allows researchers to trace his family. At least three princesses bearing the name Seshseshet are designated as "king’s eldest daughter", meaning that there were at least three different queens. It seems that there was a tenth one, born of a fourth queen as she is also designated as "king’s eldest daughter".  Another possible daughter is princess Inti.  During Teti's reign, high officials were beginning to build funerary monuments that rivaled that of the pharaoh. His vizier, Mereruka, built a mastaba tomb at Saqqara which consisted of 33 richly carved rooms, the biggest known tomb for an Egyptian nobleman. This is considered to be a sign that Egypt's wealth was being transferred from the central court to the officials, a slow process that culminated in the end to the Old Kingdom.  Manetho states that Teti was murdered by his palace bodyguards in a harem plot, but he may have been assassinated by the usurper Userkare. He was buried in the royal necropolis at Saqqara. His pyramid complex is associated with the mastabas of officials from his reign. Teti's highest date is his Year after the 6th Count 3rd Month of Summer day lost (Year 12 if the count was biannual) from Hatnub Graffito No.1. This information is confirmed by the South Saqqara Stone Annal document from Pepi II's reign which gives him a reign of around 12 years.

Third "subsidiary" pyramid to Teti's tomb.

Teti's mother was the Queen Sesheshet, who was instrumental in her son's accession to the throne and a reconciling of two warring factions of the royal family. Sesheshet lived between 2323 BC to 2291 BC. Egypt's chief archaeologist Zahi Hawass, secretary general of the Supreme Council of Antiquities, announced, on November 11, 2008, that she was entombed in a 4,300-year-old 5-metre (16-foot) tall pyramid at Saqqara. This is the 118th pyramid discovered thus far in Egypt, the largest portion of its 2-metre wide casing was built with a superstructure 5 metres high. It originally reached 14 metres, with sides 22 metres long.  Once 5 stories tall, it lay beneath 7 meters (23 feet) of sand, a small shrine and mud-brick walls from later periods. The third known "subsidiary" pyramid to Teti's tomb was originally 46 feet (14 meters) tall and 72 feet (22 meters) square at its base, due to its walls having stood at a 51-degree angle. Buried next to the Saqqara Step Pyramid, its base lies 65 feet underground and is believed to have been 50 feet tall when it was built.

Teti, less commonly known as Othoes, sometimes also Tata, Atat, or Athath in outdated sources, was the first pharaoh of the Sixth dynasty of Egypt. He is buried at Saqqara. The exact length of his reign has been destroyed on the Turin King List but is believed to have been about 12 years.


History.

Dorado was one of twelve constellations named by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. It appeared: Dorado has been represented historically as a dolphinfish and a swordfish; the latter depiction is inaccurate. It has also been represented as a goldfish. The constellation was also known in the 17th and 18th century as Xiphias. The name "Dorado" ultimately become dominant and was adopted by the IAU.

Features.

Stars.

Alpha Doradus is a blue-white star of magnitude 3.3, 176 light-years from Earth. It is the brightest star in Dorado. Beta Doradus is a notably bright Cepheid variable star. It is a yellow-tinged supergiant star that has a minimum magnitude of 4.1 and a maximum magnitude of 3.5. One thousand and forty light-years from Earth, Beta Doradus has a period of 9 days and 20 hours.  R Doradus is one of the many variable stars in Dorado. S Dor, 9.721 hypergiant in the Large Magellanic Cloud, is the prototype of S Doradus variable stars. The variable star R Doradus 5.73 has the largest known apparent size of any star other than the Sun. Gamma Doradus is the prototype of the Gamma Doradus variable stars.  Supernova 1987A was the closest supernova to occur since the invention of the telescope. SNR 0509-67.5 is the remnant of an unusually energetic Type 1a supernova from about 400 years ago.  HE 0437-5439 is a hypervelocity star escaping from the Milky Way/Magellanic Cloud system.  Dorado is also the location of the South Ecliptic pole, which lies near the fish's head. The pole was called "Polus Doradinalis" by Willem Jansson Blaeu.

Deep-sky objects.

Because Dorado contains part of the Large Magellanic Cloud, it is rich in deep sky objects. The Large Magellanic Cloud, 25,000 light-years in diameter, is a satellite galaxy of the Milky Way Galaxy, located at a distance of 179,000 light-years. It has been deformed by its gravitational interactions with the larger Milky Way. In 1987, it became host to SN 1987A, the first supernova of 1987 and the closest since 1604. This 25,000-light-year-wide galaxy contains over 10,000 million stars. All coordinates given are for Epoch J2000.0.

Equivalents.

In Chinese astronomy, the stars of Dorado are in two of Xu Guangqi's Southern Asterisms (近南極星區, "Jìnnánjíxīngōu"): the White Patches Attached (夾白, "Jiābái") and the Goldfish (金魚, "Jīnyú").

Dorado () is a constellation in the southern sky. It was named in the late 16th century and is now one of the 88 modern constellations. Its name refers to the dolphinfish ("Coryphaena hippurus"), which is known as "dorado" in Portuguese, although it has also been depicted as a swordfish. Dorado contains most of the Large Magellanic Cloud, the remainder being in the constellation Mensa. The South Ecliptic pole also lies within this constellation.


Biography.

There is no mention of a Matthias among the lists of disciples or followers of Jesus in the three synoptic gospels, but according to Acts, he had been with Jesus from his baptism by John until his Ascension. In the days following, Peter proposed that the assembled disciples, who numbered about 120, nominate two men to replace Judas. They chose Joseph called Barsabas (whose surname was Justus) and Matthias. Then they prayed, "Thou, Lord, which knowest the hearts of all [men], shew whether of these two thou hast chosen, That he may take part of this ministry and apostleship, from which Judas by transgression fell, that he might go to his own place." Then they cast lots, and the lot fell to Matthias; so he was numbered with the eleven apostles.  No further information about Matthias is to be found in the canonical New Testament. Even his name is variable: the Syriac version of Eusebius calls him throughout not Matthias but "Tolmai", not to be confused with Bartholomew (which means Son of Tolmai), who was one of the twelve original Apostles; Clement of Alexandria refers once to Zacchaeus in a way which could be read as suggesting that some identified him with Matthias; the "Clementine Recognitions" identify him with Barnabas; Hilgenfeld thinks he is the same as Nathanael in the Gospel of John.

Ministry.

The tradition of the Greeks says that St. Matthias planted the faith about Cappadocia and on the coasts of the Caspian Sea, residing chiefly near the port Issus.  According to Nicephorus ("Historia eccl.", 2, 40), Matthias first preached the Gospel in Judaea, then in Aethiopia (by the region of Colchis, now in modern-day Georgia) and was there stoned to death. An extant Coptic "Acts of Andrew and Matthias," places his activity similarly in "the city of the cannibals" in Aethiopia. A marker placed in the ruins of the Roman fortress at Gonio (Apsaros) in the modern Georgian region of Adjara claims that Matthias is buried at that site.  The "Synopsis of Dorotheus" contains this tradition: "Matthias preached the Gospel to barbarians and meat-eaters in the interior of Ethiopia, where the sea harbor of Hyssus is, at the mouth of the river Phasis. He died at Sebastopolis, and was buried there, near the Temple of the Sun."  Alternatively, another tradition maintains that Matthias was stoned at Jerusalem by the local populace, and then beheaded (cf. Tillemont, "Mémoires pour servir à l'histoire ecclesiastique des six premiers siècles", I, 406–7). According to Hippolytus of Rome, Matthias died of old age in Jerusalem.  Clement of Alexandria observed ("Stromateis" vi.13.):  Not that they became apostles through being chosen for some distinguished peculiarity of nature, since also Judas was chosen along with them. But they were capable of becoming apostles on being chosen by Him who foresees even ultimate issues. Matthias, accordingly, who was not chosen along with them, on showing himself worthy of becoming an apostle, is substituted for Judas.

Writings.

Surviving fragments of the lost Gospels of Matthias attribute it to Matthias, but Early Church Fathers attributed it to heretical writings in the 2nd century.

Veneration.

The feast of Saint Matthias was included in the Roman Calendar in the 11th century and celebrated on the sixth day to the Calends of March (24 February usually, but 25 February in leap years). In the revision of the General Roman Calendar in 1969, his feast was transferred to 14 May, so as not to celebrate it in Lent but instead in Eastertide close to the Solemnity of the Ascension, the event after which the Acts of the Apostles recounts that Matthias was selected to be ranked with the Twelve Apostles.  The Eastern Rites of the Eastern Orthodox Church celebrate his feast on 9 August. Yet the Western Rite parishes of the Orthodox Church continues the old Roman Rite of 24 and 25 February in leap years.  The Church of England's "Book of Common Prayer", as well as other older common prayer books in the Anglican Communion, celebrates Matthias on 24 February. According to the newer "Common Worship" liturgy, he is celebrated on 14 May with a Festival, although he may be celebrated on 24 February, if desired. In the Episcopal Church as well as some in the Lutheran Church, including the Lutheran Church–Missouri Synod and the Lutheran Church–Canada, his feast remains on 24 February. In "Evangelical Lutheran Worship", used by the Evangelical Lutheran Church in America as well as the Evangelical Lutheran Church in Canada, the feast date for Matthias is on 14 May.  It is claimed that St Matthias the Apostle's remains were brought to Italy through Empress Helena, mother of Emperor Constantine I (the Great); part of these relics would be interred in the Abbey of Santa Giustina, Padua, and the remaining in the Abbey of St. Matthias, Trier, Germany. According to Greek sources, the remains of the apostle are buried in the castle of Gonio-Apsaros, Georgia.

Matthias (Koine Greek: Μαθθίας, "Maththías", from Hebrew מַתִּתְיָהוּ "Mattiṯyā́hū"; ; died c. AD 80) was, according to the Acts of the Apostles (written c. AD 80–90), chosen by the apostles to replace Judas Iscariot following the latter's betrayal of Jesus and his subsequent death. His calling as an apostle is unique, in that his appointment was not made personally by Jesus, who had already ascended into heaven, and it was also made before the descent of the Holy Spirit upon the early Church.


Life.

Albert was the only son of Otto, Count of Ballenstedt, and Eilika, daughter of Magnus Billung, Duke of Saxony. He inherited his father's valuable estates in northern Saxony in 1123, and on his mother's death, in 1142, succeeded to one-half of the lands of the house of Billung. Albert was a loyal vassal of his relation, Lothar I, Duke of Saxony, from whom, about 1123, he received the Margraviate of Lusatia, to the east; after Lothar became King of the Germans, he accompanied him on a disastrous expedition to Bohemia against the upstart, Soběslav I, Duke of Bohemia in 1126 at the Battle of Kulm, where he suffered a short imprisonment.  Albert's entanglements in Saxony stemmed from his desire to expand his inherited estates there. After the death of his brother-in-law, Henry II, Margrave of the Nordmark, who controlled a small area on the Elbe called the Saxon Northern March, in 1128, Albert, disappointed at not receiving this fief himself, attacked Udo V, Count of Stade, the heir, and was consequently deprived of Lusatia by Lothar. Udo, however, was said to have been assassinated by servants of Albert on 15 March 1130 near Aschersleben. In spite of this, he went to Italy in 1132 in the train of the king, and his services there were rewarded in 1134 by the investiture of the Northern March, which was again without a ruler.  In 1138 Conrad III, the Hohenstaufen King of the Germans, deprived Albert's cousin and nemesis, Henry the Proud of his Saxon duchy, which was awarded to Albert if he could take it. After some initial success in his efforts to take possession, Albert was driven from Saxony, and also from his Northern march by a combined force of Henry and Jaxa of Köpenick, and compelled to take refuge in south Germany. When peace was made with Henry in 1142, Albert renounced the Saxon duchy and received the counties of Weimar and Orlamünde. It was possibly at this time that Albert was made Archchamberlain of the Empire, an office which afterwards gave the Margraves of Brandenburg the rights of a prince-elector.  Once he was firmly established in the Northern March, Albert's covetous eye lay also on the thinly populated lands to the north and east. For three years he was occupied in campaigns against the Slavic Wends, who as pagans were considered fair game, and whose subjugation to Christianity was the aim of the Wendish Crusade of 1147 in which Albert took part. Albert was a part of the army that besieged Demmin. And at the end of the war, recovered Havelberg, which had been lost since 983. Diplomatic measures were more successful, and by an arrangement made with the last of the Wendish princes of Brandenburg, Pribislav of the Hevelli, Albert secured this district when the prince died in 1150. Taking the title "Margrave in Brandenburg", he pressed the "crusade" against the Wends, extended the area of his mark, encouraged German migration, established bishoprics under his protection, and so became the founder of the Margraviate of Brandenburg in 1157, which his heirs — the House of Ascania — held until the line died out in 1320.  In 1158 a feud with Henry's son, Henry the Lion, Duke of Saxony, was interrupted by a pilgrimage to the Holy Land. On his return in 1160, he, with the consent of his sons; Siegfried not being mentioned, donated land to the Knights of Saint John in memory of his wife, Sofia, at Werben at the Elbe. Around this same time, he minted a pfennig in memory of his deceased wife. In 1162 Albert accompanied Emperor Frederick Barbarossa to Italy, where he distinguished himself at the storming of Milan.  In 1164 Albert joined a league of princes formed against Henry the Lion, and peace being made in 1169, Albert divided his territories among his six sons. He died on 13 November 1170, possibly in Stendal, and was buried at Ballenstedt.

Cognomen.

Albert's personal qualities won for him the cognomen of "the Bear," "not from his looks or qualities, for he was a tall handsome man, but from the cognisance on his shield, an able man, had a quick eye as well as a strong hand, and could pick what way was straightest among crooked things, was the shining figure and the great man of the North in his day, got much in the North and kept it, got Brandenburg for one there, a conspicuous country ever since," says Carlyle, who called Albert "a restless, much-managing, wide-warring man." He is also called by later writers "the Handsome."

Marriage and children.

Albert was married in 1124 to Sophie of Winzenburg (died 25 March 1160) and they had the following children:

External links.

Albert the Bear (; 1100 – 18 November 1170) was the first margrave of Brandenburg from 1157 to his death and was briefly duke of Saxony between 1138 and 1142.


Pechenga (urban-type settlement), Murmansk Oblast

History.

The Pechenga area has been indigenously inhabited by the Finnic Kvens and the Sami.  The settlement was founded as the Pechenga Monastery in 1533 at the influx of the Pechenga River into the Barents Sea, 135 km west of modern Murmansk, by St. Tryphon of Pechenga, a monk from Novgorod. In 1533, the area became part of Russia.  Inspired by the model of the Solovki, Tryphon wished to convert the local Sami population to Christianity and to demonstrate how faith could flourish in the most inhospitable lands. His example was eagerly followed by other Russian monks. By 1572, the Pechenga Monastery counted about 50 brethren and 200 lay followers. Six years after Tryphon's death in 1583, the wooden monastery was raided and burnt down by the Swedes. It is said that the raid claimed the lives of 51 monks and 65 lay brothers. The monastery was moved closer to the Norwegian border. It was destroyed in 1764, but restored in 1880, and exists to this day.  On 18 May 1918 the Finnish government declared war on Soviet Russia. During the war the area around Pechenga was occupied by the Finnish forces, and as a result of the Treaty of Tartu in 1920 became a part of Finland, renamed Petsamo. Nickel was discovered in 1921 and began to be exploited commercially in 1935. The area was captured by the Soviets during the Winter War in 1940 but returned to Finland at the conclusion of the war. During the Second World War, between 1941 through 1944, Petsamo was used as a staging post for attacks on Murmansk by Finland and Germany. Aircraft from the British aircraft carrier HMS "Furious" attacked the port on July 30, 1941. The area was captured by the Red Army during the Petsamo–Kirkenes Offensive in 1944 and in 1947, after the subsequent Paris Peace Treaty, incorporated into the Soviet Union.  After the war the area was a military zone due to its proximity to the Norwegian border. Nickel mining has led to ecological problems in the area.  The 200th Independent Motor Rifle Brigade is stationed at the settlement.

Pechenga (; Finnish and ; ; ; ) is an urban locality (an urban-type settlement) in Pechengsky District, Murmansk Oblast, Russia. Municipally, it is incorporated as Pechenga Urban Settlement of Pechengsky Municipal District. Population:


Conservation status.

The European eel is a critically endangered species. Since the 1970s, the numbers of eels reaching Europe is thought to have declined by around 90% (possibly even 98%). Contributing factors include overfishing, parasites such as "Anguillicola crassus", barriers to migration such as hydroelectric dams, and natural changes in the North Atlantic oscillation, Gulf Stream, and North Atlantic drift. Recent work suggests polychlorinated biphenyl (PCB) pollution may be a factor in the decline. TRAFFIC is introducing traceability and legality systems throughout trade change to control the decline and encourage a U-turn on the species. The species is listed in Appendix II of the CITES Convention.

Sustainable consumption.

In 2010, Greenpeace International added the European eel to its "seafood red list", and the Sustainable Eel Group launched the Sustainable Eel Standard.

Breeding projects.

As the European eel population has been falling for some time, several projects have been started. In 1997, in the Netherlands initiated a project where they attempted to get European eels to breed in captivity by simulating the journey from Europe to the Sargasso Sea with a swimming machine for the fish.  The first to achieve some success was DTU Aqua, a part of the Technical University of Denmark. Through a combination of fresh and salt water, as well as hormones, they were able to breed it in captivity in 2006 and make the larvae survive for 4.5 days after hatching. By 2007, DTU Aqua scientists were able to set a new record where the larvae survived for 12 days by feeding the mother eel with a special arginine-enriched diet. At this age the content of the larval yolk sac has been used, the mouth and digestive channel have developed, and it requires feeding. Attempts with various substances failed. Deep water sampling of the presumed habitat of larval European eel in the Sargasso Sea was performed by the Galathea 3 expedition in 2006—07, in the hope of revealing the likely feeding preference at the early stage. Their results indicated that they feed on various planktonic organisms, but especially microscopic jellyfish. A follow-up expedition was performed by DTU's own research ship to the Sargasso Sea region in 2014.  To further the research, the PRO-EEL project, led by DTU Aqua and involving several research institutes elsewhere in Denmark (University of Copenhagen and others), Norway (Norwegian Institute of Fisheries and Food Research and others), the Netherlands (Leiden University and others), Belgium (Ghent University), France (French National Center for Scientific Research and others), Spain (ICTA at Polytechnic University of Valencia) and Tunisia (National Institute of Marine Sciences and Technologies), was started in 2010. By 2014, the eel larvae at their facilities typically survive 20–22 days, but the full life cycle has still not been completed in captivity.

Life history.

Much of the European eel's life history was a mystery for centuries, as fishermen never caught anything they could identify as a young eel. Unlike many other migrating fish, eels begin their life cycle in the ocean and spend most of their lives in fresh inland water, or brackish coastal water, returning to the ocean to spawn and then die. In the early 1900s, Danish researcher Johannes Schmidt identified the Sargasso Sea as the most likely spawning grounds for European eels. The larvae (leptocephali) drift towards Europe in a 300-day migration.  When approaching the European coast, the larvae metamorphose into a transparent larval stage called "glass eel", enter estuaries, and many start migrating upstream. After entering their continental habitat, the glass eels metamorphose into elvers, miniature versions of the adult eels. As the eel grows, it becomes known as a "yellow eel" due to the brownish-yellow color of their sides and belly. After 5–20 years in fresh or brackish water, the eels become sexually mature, their eyes grow larger, their flanks become silver, and their bellies white in color. In this stage, the eels are known as "silver eels", and they begin their migration back to the Sargasso Sea to spawn.  Magnetoreception has also been reported in the European eel by at least one study, and may be used for navigation.

The European eel ("Anguilla anguilla") is a species of eel, a snake-like, catadromous fish. They are normally around and rarely reach more than, but can reach a length of up to in exceptional cases.


History.

The town began in 1142 with the settlement of Sedlec Abbey, the first Cistercian monastery in Bohemia, Sedlec Monastery, brought from the Imperial immediate Cistercian Waldsassen Abbey. By 1260, German miners began to mine for silver in the mountain region, which they named Kuttenberg, and which was part of the monastery property. The name of the mountain is said to have derived from the monks' cowls (the "Kutten") or from the word mining ("kutání" in old Czech). Under Abbot Heidenreich, the territory greatly advanced due to the silver mines which gained importance during the economic boom of the 13th century.  The earliest traces of silver have been found dating back to the 10th century, when Bohemia already had been in the crossroads of long-distance trade for many centuries. Silver dinars have been discovered belonging to the period between 982–995 in the settlement of Malín, which is now a part of Kutná Hora.  From the 13th to 16th centuries, the city competed with Prague economically, culturally, and politically. Since 1995, the city center has been a UNESCO World Heritage Site.  In 1300, King Wenceslaus II of Bohemia issued the new royal mining code "Ius regale montanorum" (also known as "Constitutiones Iuris Metallici Wenceslai II"). This was a legal document that specified all administrative as well as technical terms and conditions necessary for the operation of mines. The city developed with great rapidity, and at the outbreak of the Hussite Wars in 1419 was the second most important city in Bohemia, after Prague, having become the favourite residence of several Bohemian kings. It was here that, on January 18, 1409, Wenceslaus IV signed the famous Decree of Kutná Hora, by which the Czech university nation was given three votes in the elections to the faculty of Prague University as against one for the three other nations.  In 1420, Emperor Sigismund made the city the base for his unsuccessful attack on the Taborites during the Hussite Wars, leading to the Battle of Kutná Hora. Kuttenberg (Kutná Hora) was taken by Jan Žižka, and after a temporary reconciliation of the warring parties was burned by the imperial troops in 1422, to prevent its falling again into the hands of the Taborites. Žižka nonetheless took the place, and under Bohemian auspices it awoke to a new period of prosperity.  Along with the rest of Bohemia, Kuttenberg (Kutná Hora) passed to the Habsburg Monarchy of Austria in 1526. In 1546, the richest mine was severely flooded. In the insurrection of Bohemia against Ferdinand I the city lost all its privileges. Repeated visitations of the plague and the horrors of the Thirty Years' War completed its ruin. Half-hearted attempts after the peace to repair the ruined mines failed; the town became impoverished, and in 1770 was devastated by fire. The mines were abandoned at the end of the 18th century. In this town, Prague groschen were minted between 1300–1547/48.  In May 1742 during the First Silesian War, a Prussian force under Frederick the Great stopped in the town prior to the Battle of Chotusitz.  Bohemia was a crownland of the Austrian Empire in 1806, and remained controlled by the Austrian monarchy after the compromise of 1867). Until 1918, Kuttenberg was the capital of the district of the same name, one of the 94 "Bezirkshauptmannschaften" in Bohemia.  Together with the rest of Bohemia, the town became part of the newly founded Czechoslovakia after World War I and the collapse of Austria-Hungary. Kutná Hora was incorporated into the Protectorate of Bohemia and Moravia by Nazi Germany in the period 1939–1945, but was restored to Czechoslovakia after World War II. The town became part of the Czech Republic in 1993, after the dissolution of Czechoslovakia.

Architecture.

The center of Kutná Hora and Sedlec Abbey with its famous ossuary are a UNESCO World Heritage Site. Among the most important buildings in the town are the Gothic, five-naved St. Barbara's Church, begun in 1388, and the Italian Court, formerly a royal residence and mint, which was built at the end of the 13th century. The Gothic Stone Haus, which since 1902 has served as a museum, contains one of the richest archives in the country. The Gothic St. James's Church, with its tower, is another prominent building. Sedlec is the site of the Gothic Cathedral of Our Lady and the famous Ossuary.

Twin towns — sister cities.

Kutná Hora is twinned with:

Kutná Hora (; medieval Czech: "Hory Kutné"; ) is a town in the Central Bohemian Region of the Czech Republic.


Life and career.

Grünfeld was born in Josefstadt, Vienna. He lost a leg in his early childhood, which was beset by poverty. However, he discovered chess, studied intensely, and quickly earned a reputation as a skilled player at the local chess club, the Wiener Schach-Klub.  The First World War (1914–1918) seriously affected Grünfeld's chances of playing the best in the world as few tournaments were played during this troubled period. He was reduced to playing correspondence matches and spent much of his spare time studying opening variations. He started a library of chess material which he kept in his small Viennese flat until his death at the age of 68 in 1962.  He developed a reputation as an expert on openings during the 1920s and success over the board soon followed. He was 1st= in Vienna (1920) with Savielly Tartakower; 1st in Margate (1923); 1st in Meran (1924); 1st in Budapest (1926) with Mario Monticelli; 1st in Vienna (1927) and he shared first spot in the Vienna tournaments of 1928 and 1933 (Trebitsch Memorial)—the former with Sándor Takács and the latter with Hans Müller; and finally he was 1st in the tournament at Ostrava of 1933. He also won in the 23rd DSB Congress at Frankfurt 1923.  During the Bad Pistyan (Piešťany) tournament of April 1922 Grünfeld introduced his most important contribution to opening theory—the Grünfeld Defence. He played the defence against Friedrich Sämisch in round 7, drawing in 22 moves, and later that year he used it successfully against Alexander Alekhine in the Vienna tournament. However, he did not play the opening frequently.  During the late 1920s and 1930s Grünfeld played top board for Austria in four Chess Olympiads (1927, 1931, 1933, 1935), and his best year was in 1927 when he scored 91⁄2/12. According to the Chessmetrics website he would have been rated around 2715 at his peak (December 1924). In May 1943, he took 2nd, behind Paul Keres, in Posen, and won in December 1943 in Vienna. After the Second World War, he tied for 3rd-4th at Vienna 1951 (Schlechter Memorial, Moshe Czerniak won). Grünfeld became an International Grandmaster in 1950. By the late 1950s he was playing very little chess and he mainly worked on his prodigious library which by now had completely filled the living room in his flat which he shared with his wife and daughter. His last tournament was Beverwijk (Hoogovens Tournament) in 1961, where in a field with five more strong grandmasters, he finished with a score of 3/9 (with only one win, against Jan Hein Donner).  He died in Ottakring, Vienna on April 3, 1962.

Playing style.

He reputedly modeled his style of play on Akiba Rubinstein's and only played 1.d4, claiming that he did not make mistakes in the opening. However, his style of avoiding complex variations together with an essentially drawish nature was simply not good enough to trouble the world's best. He is best remembered for his eponymous defence, the Grünfeld Defence (1.d4 Nf6 2.c4 g6 3.Nc3 d5) and for his general expertise in the opening.

Writings.

Ernst Grünfeld contributed many articles on openings to chess magazines around Europe. Indeed, before he had turned 20, he was already contributing articles on the Ruy Lopez to "Wiener Schachzeitung", which was one of the most popular German language chess publications of its day, and over the next 40 years or so he wrote many articles on opening theory for in Germany, Belgium, and the USSR. His favorite market was in Bulgaria though because they used to pay for his work in food rather than in money!  He published several books which were generally well received and he contributed to a seminal account of the Teplice tournament of 1922. Other publications include "The Queen's Pawn Game and the Queen's Gambit Declined" (1924) and "Taschenbuch der Eroffnungen im Schach" (1953).

Ernst Franz Grünfeld (November 21, 1893 – April 3, 1962) was a leading Austrian chess grandmaster and chess writer, mainly on opening theory.


Description.

It is a hemi-parasitic shrub, which grows on the stems of other trees. It has stems long with dichotomous branching. The leaves are in opposite pairs, strap-shaped, entire, leathery textured, long, broad and are a yellowish-green in colour. This species is dioecious and the insect-pollinated flowers are inconspicuous, yellowish-green, diameter. The fruit is a white or yellow berry containing one (very rarely several) seed embedded in the very sticky, glutinous fruit pulp.  It is commonly found in the crowns of broad-leaved trees, particularly apple, lime (linden), hawthorn and poplar.

Classification.

The mistletoe was one of the many species originally described by Linnaeus. Its species name is the Latin adjective "albus" "white". It and the other members of the genus "Viscum" were originally classified in the mistletoe family Viscaceae, but this family has since been sunk into the larger family Santalaceae.

Subspecies.

Several subspecies are commonly accepted. They differ in fruit colour, leaf shape and size, and most obviously in the host trees utilised.

Toxicity.

European mistletoe is potentially fatal, in a concentrated form, and people can become seriously ill from eating the berries.  The toxic lectin viscumin has been isolated from "Viscum album". Viscumin is a cytotoxic protein (ribosome inactivating protein, or RIP) that binds to galactose residues of cell surface glycoproteins and may be internalised by endocytosis. Viscumin strongly inhibits protein synthesis by inactivating the 60 S ribosomal subunit. The structure of this protein is very similar to other RIPs, showing the most resemblance to ricin and abrin.  Some birds have immunity to the poison and enjoy the berries, especially the mistle thrush which is named for its favourite food.

Culture, folklore and mythology.

European mistletoe has always attracted popular interest and has been surrounded by a number of myths and legends. In cultures across pre-Christian Europe, mistletoe was seen as a representation of divine male essence (and thus romance, fertility and vitality). It still plays a role in the folklore of some countries.

Celtic world.

According to Pliny the Elder, the Celts considered it a remedy for barrenness in animals and an antidote to poison, and sacred when growing on oak trees (where it is rare). He describes a Celtic ritual sacrifice and banquet at which a druid dressed in white would climb an oak tree to collect mistletoe using a golden sickle. (This legend is often referred to in the popular "Asterix" comic books, where the druid Getafix is often seen collecting mistletoe with a sickle.)  Modern druids may use the Native American "Phoradendron leucarpum" as well as other mistletoe species.

Scandinavia.

According to the 13th century "Prose Edda", the goddess Frigg had all living and inanimate things swear an oath not to hurt her son Baldr. At a gathering, other gods tested the oath by hurling stones, arrows and fire at him, all in vain. But Frigg had not demanded the oath from mistletoe, because "it seemed too young" for that. By a scheming of Loki, Baldr's brother, the blind god Höðr made an arrow from mistletoe and killed Baldr with it.  In the "Gesta Danorum" version of the story, Baldr and Höðr are rival suitors, and Höðr kills Baldr with a sword named Mistilteinn (Old Norse "mistletoe"). In addition, a sword by the same name appears in various other Norse legends.

Ancient Greece and Rome.

Mistletoe figured prominently in Greek mythology, and is believed to be the Golden Bough of Aeneas, ancestor of the Romans. Also in Greek mythology mistletoe was used by heroes to access the underworld. The Romans associated mistletoe with peace, love and understanding and hung it over doorways to protect the household.

Christianity.

When Christianity became widespread in Europe after the 3rd century AD, the religious or mystical respect for the mistletoe plant was integrated to an extent into the new religion. In some way that is not presently understood, this may have led to the widespread custom of kissing under the mistletoe plant during the Christmas season. The earliest documented case of kissing under the mistletoe dates from 16th century England, a custom that was apparently very popular at that time.  Winston Graham reports a Cornish tradition that mistletoe was originally a fine tree from which the wood of the Cross was made, but afterwards it was condemned to live on only as a parasite.  Mistletoe is commonly used as a Christmas decoration, though such use was rarely alluded to until the 18th century. According to custom, the mistletoe must not touch the ground between its cutting and its removal as the last of Christmas greens at Candlemas. It may remain hanging throughout the year, often to preserve the house from lightning or fire, until it is replaced the following Christmas Eve. The tradition has spread throughout the English-speaking world, but is largely unknown in the rest of Europe. (The similar native species "Phoradendron leucarpum" is used in North America in lieu of the European "Viscum album".)  According to an old Christmas custom, a man and a woman who meet under a hanging of mistletoe were obliged to kiss. The custom may be of Scandinavian origin. It was alluded to as common practice in 1808 and described in 1820 by American author Washington Irving in his "The Sketch Book of Geoffrey Crayon, Gent.":  In Germany, the Christmas tradition is that people who kiss under mistletoe will have an enduring love or are bound to marry one another.

Local symbol.

Every year, the UK town of Tenbury Wells holds a mistletoe festival and crowns a 'Mistletoe Queen'.  Mistletoe is the county flower of Herefordshire. It was voted such in 2002 following a poll by the wild plant conservation charity Plantlife.

Uses.

Flavoring.

Mistletoe is an ingredient of pomace brandy based liquor biska made in Istra, Croatia.

Alternative medicine.

Mistletoe leaves and young twigs are used by herbalists, and preparations made from them are popular in Europe, especially in Germany, for attempting to treat circulatory and respiratory system problems. Use of mistletoe extract in the treatment of cancer originated with Rudolf Steiner, the founder of Anthroposophy.  Although laboratory and animal experiments have suggested that mistletoe extract may affect the immune system and be able to kill some kinds of cancer cells, there is little evidence of its benefit to people with cancer.

Bird trapping.

The sticky juice of mistletoe berries was used to make birdlime, an adhesive to trap small animals or birds.

Viscum album is a species of mistletoe in the family Santalaceae, commonly known as European mistletoe, common mistletoe or simply as mistletoe (Old English "mistle"). It is native to Europe and western and southern Asia.


Life.

Klages was born in Hanover, Germany. In Munich, he studied physics, philosophy and chemistry but, after completing his doctorate in chemistry, he resolved never to work as a chemist. He met the sculptor Hans Busse and with him and Georg Meyer he founded the Deutsche Graphologische Gesellschaft (German Graphology Association) in 1894.  In Munich, Klages also encountered the writer Karl Wolfskehl and the mystic Alfred Schuler. He was a lover of Fanny zu Reventlow, the "Bohemian Countess" of Schwabing, and with Wolfskehl, Schuler and the writer Ludwig Derleth they formed a group known as the Munich Cosmic Circle, with which the poet Stefan George is sometimes associated. He wrote a book praising George's poetry in 1902. As a member of this group his philosophy contrasted the "degenerate" modern world with an ancient, and mystical, Germanic past, with a heroic role for the artist in forging a new future. George distanced himself from Klages' mystical philosophy (which was shared by Schuler), but continued for a time to publish Klages' poems in his journal "Blätter für die Kunst". Wolfskehl acquainted Klages with the work of Johann Jakob Bachofen (1815–1887), a Swiss anthropologist and sociologist, and his research into matriarchal clans.  In 1914 at the outbreak of war Klages moved to Switzerland and supported himself with his writing and income from lectures. He returned to Germany in the 1920s and in 1932 was awarded the Goethe medal for Art and Science. However, by 1936 he was under attack from Nazi authorities for lack of support and on his 70th birthday in 1942 was denounced by many newspapers in Germany. After the war he was honoured by the new government, particularly on his 80th birthday in 1952.

Work.

He created a complete theory of graphology and will be long associated with the concepts of form level, rhythm and bi-polar interpretation. Together with Friedrich Nietzsche and Henri Bergson he anticipated existential phenomenology. He also coined the term logocentrism in the 1920s.  Ludwig Klages was a major figure in the European revival of paganism and has been called "the most significant restorer of polytheism since Julian, the Roman Emperor known as 'the Apostate'(...)".  He wrote 14 books and 60 articles (1910–1948), and co-edited the journals "Berichte" (1897–1898) and its successor "Graphologische Monatshefte" until 1908. His most important works are:  As a philosopher, Klages took the Nietzschean premises of Lebensphilosophie "to their most extreme conclusions." He drew a distinction between life-affirming "Seele" (spirit) and life-destroying "Geist" (mind). "Geist" represented the forces of "modern, industrial, and intellectual rationalization", while "Seele" represented the possibility of overcoming "alienated intellectuality in favor of a new-found earthly rootedness."  When Klages died, the German philosopher Jürgen Habermas urged that Klages' "realizations concerning anthropology and philosophy of language" should not be left "hidden behind the veil" of Klages' "anti-intellectualist metaphysics and apocalyptic philosophy of history". Habermas characterized these realizations as "not outdated" but ahead of the time.  Klages voiced a fierce cultural critique of Judeo-Christianity and, on rare occasions, like in his introduction to the Nachlass of his former colleague Alfred Schuler in 1940, slipped into bouts of anti-semitism.  Klages influence was widespread and amongst his great admirers were contemporaries like Jewish thinker Walter Benjamin, philosopher Ernst Cassirer, philologist Walter F. Otto and novelist Hermann Hesse.

Ludwig Klages (10 December 1872 – 29 July 1956) was a German philosopher, psychologist and a theoretician in the field of handwriting analysis. He was nominated for the Nobel Prize in Literature.


Early life.

Géza was the elder son of Taksony, Grand Prince of the Hungarians. His mother was his father's wife "from the land of the Cumans", according to the anonymous author of the "Gesta Hungarorum". This anachronistic reference to the Cumans suggests that she was of Khazar, Pecheneg or Volga Bulgarian origin. The Byzantine Emperor Constantine VII Porphyrogenitus, who listed the descendants of Grand Prince Árpád around 950, did not mention Géza. Even so, Gyula Kristó wrote that Géza was born around 940 and the emperor ignored him because of his youth. The genuine form of his name was either "Gyeücsa" or "Gyeusa", which is possibly a diminutive form of the Turkic title "yabgu". Géza's father arranged his marriage with Sarolta daughter of a Hungarian chieftain called Gyula, who ruled Transylvania independently of the grand prince and had converted to Christianity in Constantinople. Sarolt seems to have also adhered to Eastern Orthodox Christianity, according to Bruno of Querfurt's remark on her "languid and muddled Christianity".

Reign.

Géza succeeded his father around 972. He adopted a centralizing policy, which gave rise to his fame as a merciless ruler. The longer version of his son's "Life" even states that Géza's hands were "defiled with blood". Pál Engel wrote that Géza carried out a "large-scale purge" against his relatives, which explains the lack of references to other members of the Árpád dynasty from around 972. Koppány, who continued to rule the southern parts of Transdanubia, is the only exception to this dearth of references. A marriage alliance between the German and Byzantine dynasties brought about a rapprochement between the two powers neighboring Hungary in 972. Géza decided to make peace with the Holy Roman Empire. First, a monk named Bruno sent by Otto I, Holy Roman Emperor arrived in Hungary around 972. Hungarian "legates" were present at a conference held by the emperor in Quedlinburg in 973.  A record on one Bishop Prunwart in the Abbey of Saint Gall mentions his success in baptising many Hungarians, including their "king". The nearly contemporaneous Thietmar of Merseburg confirms that the conversion to Christianity of the pagan Hungarians started under Géza, who became the first Christian ruler of Hungary. His baptismal name was Stephen. However, Géza continued to observe pagan cults, which proves that his conversion to Christianity was never complete. Kristó and other historians have said that the first Roman Catholic diocese in Hungary, with its seat in Veszprém, was set up in Géza's reign, but their view has not been unanimously accepted. A charter issued during his son's reign states that Géza was the founder of the Benedictine Pannonhalma Archabbey.  Taking advantage of internal conflicts which emerged in the Holy Roman Empire after Emperor Otto I's death, Géza invaded Bavaria and took the fortress of Melk in 983. In 991, the Bavarians launched a counter-attack which forced Géza to withdraw Hungarian forces from the territories east of the Vienna Woods. Furthermore, he renounced the lands east of the river Leitha in his peace treaty of 996 with Henry IV of Bavaria. Géza also arranged the marriage of his son and heir Stephen to Henry IV's sister Giselle. Even before this marriage alliance, Géza convoked the Hungarian leaders to an assembly and forced them to take an oath confirming his son's right to succeed him.

Family.

Sarolt gave birth to at least three of Géza's children; Stephen, who succeeded his father on the throne, and two unnamed daughters. Sarolt survived Géza, which suggests that she was also the mother of Géza's daughters. Based on the "Polish-Hungarian Chronicle", Szabolcs de Vajay wrote that the daughters' mother was Géza's alleged second wife Adelaide of Poland, but this has not been widely accepted. Adelaide is only mentioned in the "Polish–Hungarian Chronicle", which describes her as the sister of Mieszko I of Poland, but specialists have often questioned her real existence. The chronicle attributes Géza's conversion to Adelaide's influence.  The following family tree presents Géza's ancestry and his offspring.  "*Whether Menumorut is an actual or an invented person is debated by modern scholars."
"**A Khazar, Pecheneg or Volga Bulgarian lady."
"***Samuel Aba might have been Géza's grandson instead of his son-in-law."
"****The Aba family descending from them still flourished in the 14th century."

Sources.

Secondary sources.

Géza ( 940 – 997), also Gejza, was Grand Prince of the Hungarians from the early 970s. He was the son of Grand Prince Taksony and his OrientalKhazar, Pecheneg or Volga Bulgarianwife. He married Sarolt, a daughter of an Eastern Orthodox Hungarian chieftain. After ascending the throne, Géza made peace with the Holy Roman Empire. Within Hungary, he consolidated his authority with extreme cruelty, according to the unanimous narration of nearly contemporaneous sources. He was the first Hungarian monarch to support Christian missionaries from Western Europe. Although he was baptised (his baptismal name was Stephen), his Christian faith remained shallow and he continued to perform acts of pagan worship. He was succeeded by his son, Stephen who was crowned the first King of Hungary in 1000 or 1001.


Personal life.

Briggs was born at Daisy Bank, Sowerby Bridge, near Halifax, in Yorkshire, England. After studying Latin and Greek at a local grammar school, he entered St John's College, Cambridge, in 1577, and graduated in 1581. In 1588, he was elected a Fellow of St John's. In 1592 he was made reader of the physical lecture founded by Thomas Linacre; he would also read some of the mathematical lectures as well. During this period, he took an interest in navigation and astronomy, collaborating with Edward Wright.  In 1596, he became first professor of geometry in the recently founded Gresham College, London, where he also taught astronomy and navigation. He lectured there for nearly 23 years, and made Gresham College a centre of English mathematics, from which he would notably support the new ideas of Johannes Kepler.  He was a friend of Christopher Heydon, a writer on astrology, though Briggs himself rejected astrology for religious reasons. He once called astrology, "a mere system of groundless conceits".  At this time, Briggs obtained a copy of "Mirifici Logarithmorum Canonis Descriptio", in which Napier introduced the idea of logarithms. It has also been suggested that he knew of the method outlined in "Fundamentum Astronomiae" published by the Swiss clockmaker Jost Bürgi, through John Dee. Napier's formulation was awkward to work with, but the book fired Briggs' imagination – in his lectures at Gresham College he proposed the idea of base 10 logarithms in which the logarithm of 10 would be 1; and soon afterwards he wrote to the inventor on the subject. Briggs was active in many areas, and his advice in astronomy, surveying, navigation, and other activities like mining was frequently sought. Briggs in 1619 invested in the London Company, and he had two sons: Henry, who later emigrated to Virginia, and Thomas, who remained in England.  Briggs died on 26 January 1630, and was buried in the chapel of Merton College, Oxford. Dr Smith, in his "Lives of the Gresham Professors", characterizes him as a man of great probity, a condemner of riches, and contented with his own station, preferring a studious retirement to all the splendid circumstances of life. The lunar crater Briggs is named in his honour.

Mathematical contributions.

In 1616 Briggs visited Napier at Edinburgh in order to discuss the suggested change to Napier's logarithms. The following year he again visited for a similar purpose. During these conferences the alteration proposed by Briggs was agreed upon; and on his return from his second visit to Edinburgh, in 1617, he published the first chiliad of his logarithms.  In 1619 he was appointed Savilian Professor of Geometry at the University of Oxford, and resigned his professorship of Gresham College in July 1620. Soon after his settlement at Oxford he was incorporated Master of Arts.  In 1622 he published a small tract on the "Northwest Passage to the South Seas, through the Continent of Virginia and Hudson Bay". The tract is notorious today as the origin of the cartographic myth of the Island of California. In it Briggs stated he had seen a map that had been brought from Holland that showed the Island of California. The tract was republished three years later (1625) in Pvrchas His Pilgrimes (vol 3, p848).  In 1624 his "Arithmetica Logarithmica" was published, in folio, a work containing the logarithms of thirty thousand natural numbers to fourteen decimal places (1-20,000 and 90,001 to 100,000). This table was later extended by Adriaan Vlacq to 10 places, and by Alexander John Thompson to 20 places in 1952. Briggs was one of the first to use finite-difference methods to compute tables of functions.  He also completed a table of logarithmic sines and tangents for the hundredth part of every degree to fourteen decimal places, with a table of natural sines to fifteen places, and the tangents and secants for the same to ten places; all of which were printed at Gouda in 1631 and published in 1633 under the title of "Trigonometria Britannica"; this work was probably a successor to his 1617 "Logarithmorum Chilias Prima" ("The First Thousand Logarithms"), which gave a brief account of logarithms and a long table of the first 1000 integers calculated to the 14th decimal place.  Briggs discovered, in a somewhat concealed form and without proof, the binomial theorem. English translations of Briggs's "Arithmetica" and the first part of his "Trigonometria Britannica" are available on the web.  Some other works, as his "Commentaries on the Geometry of Peter Ramus", and "Remarks on the Treatise of Longomontanus respecting the Quadrature of the Circle" have not been published.

Henry Briggs (February 1561 – 26 January 1630) was an English mathematician notable for changing the original logarithms invented by John Napier into common (base 10) logarithms, which are sometimes known as Briggsian logarithms in his honour.


History.

Interest in polymorphic type systems developed significantly in the 1960s, with practical implementations beginning to appear by the end of the decade. "Ad hoc polymorphism" and "parametric polymorphism" were originally described in Christopher Strachey's "Fundamental Concepts in Programming Languages", where they are listed as "the two main classes" of polymorphism. Ad hoc polymorphism was a feature of Algol 68, while parametric polymorphism was the core feature of ML's type system.  In a 1985 paper, Peter Wegner and Luca Cardelli introduced the term "inclusion polymorphism" to model subtypes and inheritance, citing Simula as the first programming language to implement it.

Types.

Ad hoc polymorphism.

Christopher Strachey chose the term "ad hoc polymorphism" to refer to polymorphic functions that can be applied to arguments of different types, but that behave differently depending on the type of the argument to which they are applied (also known as function overloading or operator overloading). The term "ad hoc" in this context is not intended to be pejorative; it refers simply to the fact that this type of polymorphism is not a fundamental feature of the type system. In the Pascal / Delphi example below, the codice_1 functions seem to work generically over various types when looking at the invocations, but are considered to be two entirely distinct functions by the compiler for all intents and purposes: program Adhoc;  function Add(x, y : Integer) : Integer; begin end;  function Add(s, t : String) : String; begin end;  begin end. In dynamically typed languages the situation can be more complex as the correct function that needs to be invoked might only be determinable at run time.  Implicit type conversion has also been defined as a form of polymorphism, referred to as "coercion polymorphism".

Parametric polymorphism.

"Parametric polymorphism" allows a function or a data type to be written generically, so that it can handle values "uniformly" without depending on their type. Parametric polymorphism is a way to make a language more expressive while still maintaining full static type-safety.  The concept of parametric polymorphism applies to both data types and functions. A function that can evaluate to or be applied to values of different types is known as a "polymorphic function." A data type that can appear to be of a generalized type (e.g. a list with elements of arbitrary type) is designated "polymorphic data type" like the generalized type from which such specializations are made.  Parametric polymorphism is ubiquitous in functional programming, where it is often simply referred to as "polymorphism". The following example in Haskell shows a parameterized list data type and two parametrically polymorphic functions on them: data List a = Nil | Cons a (List a)  length :: List a -> Integer length Nil = 0 length (Cons x xs) = 1 + length xs  map :: (a -> b) -> List a -> List b map f Nil = Nil map f (Cons x xs) = Cons (f x) (map f xs) Parametric polymorphism is also available in several object-oriented languages. For instance, templates in C++ and D, or under the name generics in C#, Delphi and Java: class List<T> {  List<B> map(Func<A, B> f, List<A> xs) { John C. Reynolds (and later Jean-Yves Girard) formally developed this notion of polymorphism as an extension to lambda calculus (called the polymorphic lambda calculus or System F). Any parametrically polymorphic function is necessarily restricted in what it can do, working on the shape of the data instead of its value, leading to the concept of parametricity.

Subtyping.

Some languages employ the idea of "subtyping" (also called "subtype polymorphism" or "inclusion polymorphism") to restrict the range of types that can be used in a particular case of polymorphism. In these languages, subtyping allows a function to be written to take an object of a certain type "T", but also work correctly, if passed an object that belongs to a type "S" that is a subtype of "T" (according to the Liskov substitution principle). This type relation is sometimes written "S" <: "T". Conversely, "T" is said to be a "supertype" of "S"—written "T" :> "S". Subtype polymorphism is usually resolved dynamically (see below).  In the following example we make cats and dogs subtypes of animals. The procedure codice_2 accepts an animal, but will also work correctly if a subtype is passed to it: abstract class Animal {  class Cat extends Animal {  class Dog extends Animal {  static void letsHear(final Animal a) {  static void main(String[] args) {  In another example, if "Number", "Rational", and "Integer" are types such that "Number" :> "Rational" and "Number" :> "Integer", a function written to take a "Number" will work equally well when passed an "Integer" or "Rational" as when passed a "Number". The actual type of the object can be hidden from clients into a black box, and accessed via object identity. In fact, if the "Number" type is "abstract", it may not even be possible to get your hands on an object whose "most-derived" type is "Number" (see abstract data type, abstract class). This particular kind of type hierarchy is known—especially in the context of the Scheme programming language—as a "numerical tower", and usually contains many more types.  Object-oriented programming languages offer subtype polymorphism using "subclassing" (also known as "inheritance"). In typical implementations, each class contains what is called a "virtual table"—a table of functions that implement the polymorphic part of the class interface—and each object contains a pointer to the "vtable" of its class, which is then consulted whenever a polymorphic method is called. This mechanism is an example of: The same goes for most other popular object systems. Some, however, such as Common Lisp Object System, provide "multiple dispatch", under which method calls are polymorphic in "all" arguments.  The interaction between parametric polymorphism and subtyping leads to the concepts of variance and bounded quantification.

Row polymorphism.

Row polymorphism is a similar, but distinct concept from subtyping. It deals with structural types. It allows the usage of all values whose types have certain properties, without losing the remaining type information.

Polytypism.

A related concept is "polytypism" (or "data type genericity"). A polytypic function is more general than polymorphic, and in such a function, "though one can provide fixed ad hoc cases for specific data types, an ad hoc combinator is absent".

Implementation aspects.

Static and dynamic polymorphism.

Polymorphism can be distinguished by when the implementation is selected: statically (at compile time) or dynamically (at run time, typically via a virtual function). This is known respectively as "static dispatch" and "dynamic dispatch," and the corresponding forms of polymorphism are accordingly called "static polymorphism" and "dynamic polymorphism".  Static polymorphism executes faster, because there is no dynamic dispatch overhead, but requires additional compiler support. Further, static polymorphism allows greater static analysis by compilers (notably for optimization), source code analysis tools, and human readers (programmers). Dynamic polymorphism is more flexible but slower—for example, dynamic polymorphism allows duck typing, and a dynamically linked library may operate on objects without knowing their full type.  Static polymorphism typically occurs in ad hoc polymorphism and parametric polymorphism, whereas dynamic polymorphism is usual for subtype polymorphism. However, it is possible to achieve static polymorphism with subtyping through more sophisticated use of template metaprogramming, namely the curiously recurring template pattern.

In programming languages and type theory, polymorphism is the provision of a single interface to entities of different types or the use of a single symbol to represent multiple different types.


Biography.

Arutiunian was born in Yerevan, Armenia, in the family of Grigor and Eleonora Arutiunian. His father was a military serviceman. In 1927, Arutiunian became a member of the Yerevan State Conservatory’s children group, then, at age 14, he was admitted to the Conservatory to the studios of Olga Babasyan (piano), and Sergei Barkhudaryan and Vardges Talyan (composition). He graduated from the Music Conservatory of Yerevan on the eve of World War II. After the war he moved to Moscow, where between 1946 and 1948 he participated in the workshops of House of Armenian Culture, studied composition with Genrikh Litinsky. After graduation he returned to Yerevan to teach at the local Conservatory and in 1954 he was appointed artistic director of the Armenian State Philharmony. He was also a member of the Board of the USSR Composers' Union, as well as of the Armenian SSR Composers’ Union.  In 1949, Arutiunian was awarded the Stalin Prize for his cantata "Motherland", a graduation piece he wrote as a student at the Moscow Conservatory. The USSR Radio Choir and Orchestra premiered this work in November 1948.  In 1949, Arutiunian composed the "Festive Overture" that was first performed in the Big Hall of the Leningrad Philharmonic in November 1949, with Evgeny Mravinsky conducting. During the Moscow Music Congress Aram Khachaturian considered him as a promising Soviet composer. He continued to win acclaim at home and abroad for his works, many of which are quickened by the folk traditions of Armenian music. Other works of that kind include "The tale of Armenian people" (1960), "Ode to Lenin" (1967) and "Hymn to the brotherhood" (1970).  Some of Arutiunian's works for wind instruments include his 1950 concerto for trumpet, the concerto for tuba, and the brass quintet "Armenian Scenes". In 1988, inspired by the Spitak earthquake, Arutiunian composed his Concerto for Violin and String Orchestra, "Armenia-88" (dedicated to Ruben Aharonyan). The premiere took place in Yerevan in 1989.  In September 2010 Arutiunian's 90th birthday was celebrated by a series of concerts.

Trumpet Concerto in A-flat major (1950).

Arutiunian's "Trumpet Concerto" consists of the following movements:  The melodic and rhythmic characteristics of Armenian folk music are a strong influence in Arutiunian's work. As a composer, he expressed his nationality by incorporating the flavor of ashughner (folk minstrel) improvisations. At the time the concerto was written, his compositional style was similar to Khachaturian's. However, in the 1960s he tended towards classical forms and clearer tonality.  Arutiunian's trumpet concerto was his sixth major composition, written in 1950. Arutiunian originally intended to write it in 1943 for a student of Tabakov, Zsolak Vartasarian, who was the principal trumpet in the Armenian Philharmonic Orchestra. However, Vartasarian died in the war and the concerto was not completed until 1950, so Aykaz Messlayan was the first performer of the Concerto and Timofei Dokschitzer was the first to record this concerto.  The concerto's introduction to the United States is solely due to Dokschitzer, a leading Soviet Russian trumpeter.

Personal life.

In 1950, Arutiunian married Irina (Tamara) Odenova. Their marriage produced two children, a daughter, Narine (born 1951), who is a pianist and lawyer; and a son, Suren (born 1953), who is an artist-designer. His extended family includes 3 granddaughters and a grandson. He died, aged 91, in his home city of Yerevan. Arutiunian is buried at the Komitas Pantheon which is located in the city center of Yerevan.

Works.

Important works include:

Alexander Grigori Arutiunian (), also known as Arutunian, Arutyunyan, Arutjunjan, Harutyunian or Harutiunian (23 September 1920 – 28 March 2012), was a Soviet and Armenian composer and pianist, widely known for his 1950 trumpet concerto. A professor at Yerevan State Conservatory, he was recognized with many awards for his work, including the Stalin Prize in 1949 and People's Artist of the USSR in 1970, as well as numerous honors from his homeland of Armenia.