History.

Sylvaner is an ancient variety that has long been grown in Central Europe, in Transylvania. In Germany it is best known as a component of Liebfraumilch and production boomed in the 1970s to the detriment of quality, but it has long enjoyed a better reputation in Franconia than in other German wine regions. DNA fingerprinting has revealed it to be a cross between Traminer and the "hunnic" variety Österreichisch-Weiß (meaning "Austrian White"). As a result, it is now thought to have originated in Austrian Empire (Transylvania).  It is thought that the grape came to Germany after the Thirty Years War as there is a record of Sylvaner from Austria being planted at County of Castell in Franconia on 5 April 1659. So Germany celebrated the 350 anniversary of Silvaner in 2009. Its name has been taken to be associated with either Latin "silva" (meaning woods) or "saevum" (meaning wild), and before modern ampelography it was sometimes assumed that this variety had a close relationship with wild vines. Before DNA typing, some assumed an origin in Transylvania based on its name.  A lot of Sylvaner was planted in Germany and Alsace after the Second World War, reaching 30% and 25% respectively of total vineyard area in the 1960s - 1970s. It was Germany's most grown variety until it was overtaken by Müller-Thurgau around 1970. Much of the German crop was blended into Liebfraumilch, but overproduction ruined its reputation, and changing tastes led to many vines being grubbed up. Liebfraumilch became popular again with new wine drinkers and again changing tastes. However, in Franconia, where Liebfraumilch may not be produced and which primarily stuck to dry white wines in the decades when most other German regions produced semi-sweet wines, Silvaner has kept its popularity. Single-variety semi-sweet Silvaner, which used to be common, has all but disappeared from the German wine production.  More recently there has been a revival in Alsace based on low yields from good vineyard sites, with formal recognition in 2006 as Zotzenburg Sylvaner became the first to be designated an Alsace Grand Cru.

Distribution and wines.

Australia.

In the 1970s Brown Brothers experimented with "Syilvaner" in northeastern Victoria, but nothing seems to have come of it.

Austria.

There are just of Sylvaner in its land of origin, a victim of the trend in Austrian wine towards drier styles.

Croatia.

Sylvaner ("silvanac zeleni" in Croatian) is grown in Eastern Croatia, in the regions of Slavonija and Srijem, as well as in other regions. In recent years high-quality semi-dry Silvanac zeleni from Orahovica has become one of Croatia's more popular whites.

France.

Sylvaner has a controversial place in Alsace wine. Since 2006, it may be used in Alsace Grand Cru, which was previously reserved for the four "noble grapes" Gewürztraminer, Muscat, Pinot gris and Riesling, but only in the Zotzenberg vineyard, which together with Altenberg de Bergheim and Kaefferkopf were allowed to produce mixed variety wines as Alsace Grand Cru. Zotzenberg Grand Cru wines may consist of Gewürztraminer, Pinot gris, Riesling and Sylvaner in any combination. It is therefore possible to produce a varietally pure "Sylvaner Grand Cru" from this vineyard, but it may not be labelled so, only "Zotzenberg". Even after this, Jean Trimbach's view was that "This Sylvaner grand cru is only possible in Zotzenberg, it is a recognition of the terroir, but we should stop there." As in Germany, Sylvaner has been falling in popularity since the 1970s, declining from 25% of Alsace vineyards to 10% in that time.

Germany.

First recorded at Castell in 1659, Silvaner (with an 'i') reached a peak in the 1960s-1970s, with 30% of German vineyards. However overproduction during the Liebfraumilch years ruined its reputation, and it has since retreated to its stronghold in Franconia (Frankenland) (1,425 ha), where on the best chalky Muschelkalk terroir it can produce wines that can compete with the best German white wines which usually are made out of the Riesling grape. These powerful wines are considered food-friendly and are often described as having an "earthy" palate. Under VDP Erste Lage/Grosses Gewächs rules, Silvaner may be used for Grosses Gewächs wines (top-end dry wines), but only in Franconia and Saale-Unstrut and not in any of the other 11 German wine regions. Silvaner is also grown in Rheinhessen (2,486 ha) and Palatinate, and is sometimes also made into dessert wine. Currently there are in Germany, just 5% of the total area under vine.  The official name of the variety in Germany is "Grüner Silvaner", spelled with an "i" in difference from Alsace and its homeland of Austria.  The Silvaner is not usually matured in barrique (oak) barrels to avoid the fine and fruity body of the Silvaner being overwhelmed by the oak taste.

Romania.

In Transylvania, presumed to be the homeland of Silvaner, two varieties of this grape are grown: the Sylvaner roz (rosé) and the Sylvaner Verde B (Grüner Silvaner, Silvaner) in wineyards as Jidvei (Tarnava) and Nachbil (Dealurile Sătmarului - Satu Mare)

Slovakia.

Silvaner is traditionally grown in the Limbach village in Slovakia, that is famous for its varietal Silvaner wines, and in its surroundings.

Switzerland.

Some is grown in Switzerland, where it is known as Johannisberger or Sylvaner with an "y".

USA.

In 1858, Emil Dresel brought the first Sylvaner cuttings to America and planted them on what is now the Scribe Estate in Sonoma County. In his honor, Scribe Winery planted one acre in 2007. It has been grown for many years at Rancho Sisquoc Winery in the Santa Maria Valley of California. Otherwise, Sylvaner has more or less disappeared from California, where it was known as Sylvaner Riesling, Franken Riesling, Monterey Riesling, and Sonoma Riesling. Oregon does have some Sylvaner at David Hill Vineyards in Forest Grove.

Vine and viticulture.

The vine is vigorous and productive, with three-lobed leaves. The bunches are small and cylindrical, with medium green berries that ripen quickly.  In 1940, Silvaner was crossed with Chasselas to produce the white grape variety Nobling.

Synonyms.

Silvaner is also known under the following synonyms: Arvine, Arvine Grande, Augustiner Weiss, Beregi Szilvani, Boetzinger, Clozier, Cynifadl Zeleny, Cynifal, Fliegentraube, Frankenriesling, Frankentraube, Fueszeres Szilvani, Gamay blanc, GentilvVert, Gros Rhin, Gros-rhin, Gruen Silvaner, Gruenedel, Gruenfraenkisch, Grün Silvaner, Haeusler Schwarz, Johannisberger, Mishka, Momavaka, Monterey Riesling, Moravka, Movavka, Muschka, Mushza, Musza, Nemetskii Rizling, Oesterreicher, Oestreicher, Pepltraube, Picardon blanc, Picardou blanc, Plant Du Rhin, Rhin, Rundblatt, Salfin, Salfine Bely, Salvaner, Salviner, Scharvaner, Scherwaner, Schoenfeilner, Schwaebler, Schwuebler, Sedmogradka, Sedmogradska Zelena, Selenzhiz, Selivan, Silvanske Zelene, Sonoma Riesling, Sylvan Zeleny, Sylvaner, Sylvaner verde, Szilvani Feher, Tschafahnler, Yesil Silvaner, Zelencic, Zeleny, Zierfandler, Zierifandel, Zinifal, Zoeld Szilvani, Zoeldsilvani, Syilvaner, Siylvaner, Sylvaner vert, Grüner Sylvaner, Grünfraenkisch, Franken Riesling and Grüner Silvaner.

Sylvaner or Silvaner is a variety of white wine grape grown primarily in Alsace and Germany, where its official name is Grüner Silvaner. While the Alsatian versions have primarily been considered simpler wines, it was recently (2006) included among the varieties that can be used to produce Alsace Grand Cru wine together with the four 'noble grapes' of Alsace, although only in one vineyard, Zotzenberg.


History of the grape variety.

Most grapes have been created from a desire to harness qualities in two separate grapes and to generate a new vine that combines the qualities of both.  When Dr. Müller created the grape in the Geisenheim Grape Breeding Institute in the late 19th century, his intention was to combine the intensity and complexity of the Riesling grape with the ability to ripen earlier in the season that the Silvaner grape possesses. Although the resulting grape did not entirely attain these two qualities, it nonetheless became widely planted across many of the German wine-producing regions. By the 1970s, Müller-Thurgau had become Germany's most-planted grape. A possible reason for the popularity of this varietal is that it is capable of being grown in a relatively wide range of climates and soil types. Many of these vines were planted on flat areas that were not particularly suitable for growing other wine grapes because it was more profitable than sugar beet, which was the main alternative crop in those locations. The vines mature early and bring large yield quantities, and are less demanding as to planting site than for example Riesling. Müller-Thurgau wines are mild due to low acidic content, but nevertheless fruity. The wines may be drunk while relatively young, and with few exceptions are not considered to improve with age. These facts meant that Müller-Thurgau provided an economical way to cheaply produce large amounts of medium sweet German wines, such as Liebfraumilch and Piesporter, which were quite popular up until the 1980s.  The turning point in Müller-Thurgau's growth however was the winter of 1979, when on 1 January there was a sharp fall in temperatures, to 20 °F (−7 °C) in many areas, which devastated most of the new varieties, but did not affect the varieties such as Riesling which have much more hardy stems, after hundreds of years of selection. In the decades since then, the winemakers have begun to grow a wider variety of vines, and Müller-Thurgau is now less widely planted in Germany than Riesling, although still significant in that country and worldwide.  While the total German plantations of Müller-Thurgau are declining, the variety is still in third place among new plantations in Germany, after Riesling and Pinot noir, with around 8% of all new plantations in the years 2006-2008.

Genealogy.

Recent DNA fingerprinting has in fact determined that the grape was created by crossing Riesling with Madeleine Royale, not Silvaner or any other suggested grape variety. But there has been some confusion on the way. In 1996, Chasselas seemed to be a valid candidate, and in 1997 the Chasselas variety Admirable de Courtiller was specified. However, this was shown to be wrong when the reference grape that was believed to be Admirable de Courtiller was proven in the year 2000 to be Madeleine Royale. Madeleine Royale was long believed to be a Chasselas seedling, but modern DNA fingerprinting methods suggest that it is actually a crossing of Pinot and Trollinger.

German growing regions.

As of 2006, German regional plantings stood at:  Outside of Germany, the grape has achieved a moderate degree of success in producing lively wines in Italy, southern England (where most other grapes will not ripen in many years) Luxembourg (where it is called Rivaner), Czech Republic, and the United States.  In Germany, it has long been common to blend Müller-Thurgau with Bacchus, or small amounts of Morio Muscat to enhance its flavours. Both are highly aromatic which don't work very well in varietal wines on their own because of a lack of acidity or structure.

Synonyms.

Synonyms for Müller-Thurgau include Miler Turgau, Müller, Müller-Thurgaurebe, Müllerka, Müllerovo, Muller-Thurgeau, Mullerka, Mullerovo, Riesling-Silvaner, Riesling-Sylvamer, Riesling x Silavaner, Rivaner, Rizanec, Rizlingsilvani, Rizlingszilvani, Rizlingzilvani, Rizvanac, Rizvanac Bijeli, Rizvanec, Rizvaner.

Müller-Thurgau is a white grape variety (sp. "Vitis vinifera") which was created by Hermann Müller from the Swiss Canton of Thurgau in 1882. It is a crossing of Riesling with Madeleine Royale. It is used to make white wine in Germany, Austria, Northern Italy, Hungary, England, Australia, the Czech Republic, Slovakia, Slovenia, New Zealand, the United States and Japan. There are around 42,000 hectares (104,000 acres) cultivated worldwide, which makes Müller-Thurgau the most widely planted of the so-called "new breeds" of grape varieties created since the late 19th century. Although plantings have decreased significantly since the 1980s, as of 2006 it was still Germany's second most planted variety at 14,000 hectares and 13.7% of the total vineyard surface. In 2007, the 125th anniversary was celebrated at the Geisenheim Grape Breeding Institute. Müller-Thurgau is also known as Rivaner (Austria, Germany, Luxembourg, and especially for dry wines), Riesling x Sylvaner, Riesling-Sylvaner (Switzerland), Johannisberg (Wallis canton in Switzerland), Rizvanec (Slovenia) and Rizlingszilváni (Hungary).


Definitions.

Neighbourhood of a point.

If formula_1 is a topological space and formula_2 is a point in formula_1, a neighbourhood of formula_2 is a subset formula_5 of formula_1 that includes an open set formula_7 containing formula_2,  This is also equivalent to formula_10 being in the interior of formula_5.  The neighbourhood formula_5 need not be an open set itself. If formula_5 is open it is called an. Some mathematicians require that neighbourhoods be open, so it is important to note conventions. A set that is a neighbourhood of each of its points is open since it can be expressed as the union of open sets containing each of its points. A rectangle, as illustrated in the figure, is not a neighbourhood of all its points; points on the edges or corners of the rectangle are not contained in any open set that is contained within the rectangle.  The collection of all neighbourhoods of a point is called the neighbourhood system at the point.

Neighbourhood of a set.

If formula_14 is a subset of topological space formula_1 then a neighbourhood of formula_14 is a set formula_5 that includes an open set formula_7 containing formula_14. It follows that a set formula_5 is a neighbourhood of formula_14 if and only if it is a neighbourhood of all the points in formula_14. Furthermore, it follows that formula_5 is a neighbourhood of formula_14 iff formula_14 is a subset of the interior of formula_5. The neighbourhood of a point is just a special case of this definition.

In a metric space.

In a metric space formula_27, a set formula_5 is a neighbourhood of a point formula_2 if there exists an open ball with centre formula_2 and radius formula_31, such that is contained in formula_5.  formula_5 is called uniform neighbourhood of a set formula_14 if there exists a positive number formula_36 such that for all elements formula_2 of formula_14, is contained in formula_5.  For formula_41 the formula_36-neighbourhood formula_43 of a set formula_14 is the set of all points in formula_1 that are at distance less than formula_36 from formula_14 (or equivalently, formula_14 is the union of all the open balls of radius formula_36 that are centred at a point in formula_14): formula_51  It directly follows that an formula_36-neighbourhood is a uniform neighbourhood, and that a set is a uniform neighbourhood if and only if it contains an formula_36-neighbourhood for some value of formula_36.

Examples.

Given the set of real numbers formula_55 with the usual Euclidean metric and a subset formula_5 defined as then formula_5 is a neighbourhood for the set formula_59 of natural numbers, but is "not" a uniform neighbourhood of this set.

Topology from neighbourhoods.

The above definition is useful if the notion of open set is already defined. There is an alternative way to define a topology, by first defining the neighbourhood system, and then open sets as those sets containing a neighbourhood of each of their points.  A neighbourhood system on formula_1 is the assignment of a filter formula_61 of subsets of formula_1 to each formula_63 in formula_1, such that  One can show that both definitions are compatible, i.e. the topology obtained from the neighbourhood system defined using open sets is the original one, and vice versa when starting out from a neighbourhood system.

Uniform neighbourhoods.

In a uniform space formula_76, formula_5 is called a uniform neighbourhood of formula_78 if there exists an entourage formula_79 such that formula_5 contains all points of formula_1 that are formula_7-close to some point of formula_78; that is, formula_84 for all formula_85.

Deleted neighbourhood.

A deleted neighbourhood of a point formula_2 (sometimes called a punctured neighbourhood) is a neighbourhood of formula_2, without formula_88. For instance, the interval formula_89 is a neighbourhood of formula_90 in the real line, so the set formula_91 is a deleted neighbourhood of formula_92. A deleted neighbourhood of a given point is not in fact a neighbourhood of the point. The concept of deleted neighbourhood occurs in the definition of the limit of a function.

In topology and related areas of mathematics, a neighbourhood (or neighborhood) is one of the basic concepts in a topological space. It is closely related to the concepts of open set and interior. Intuitively speaking, a neighbourhood of a point is a set of points containing that point where one can move some amount in any direction away from that point without leaving the set.


Life.

Zimmermann was born in Bliesheim (now part of Erftstadt) near Cologne. He grew up in a rural Catholic community in western Germany. His father worked for the German Reichsbahn (Imperial Railway) and was also a farmer. In 1929, Zimmermann began attending a private Catholic school, where he had his first real encounter with music. After the National Socialists (or Nazis) closed all private schools, he switched to a public Catholic school in Cologne where, in 1937, he received his Abitur, the German equivalent of a high school diploma.  In the same year, he fulfilled his duty for the Reichsarbeitsdienst and spent the 1937/1938 winter semester studying pedagogy at the Hochschule für Lehrerausbildung (lit. University for Teacher Training) in Bonn.  He began studying Music Education, Musicology and Composition in the winter of 1938 at the University for Music in Cologne. In 1940, he was drafted in the Wehrmacht (the German Army) but was released in 1942 due to a severe skin illness. After he returned to his studies, he didn't receive a degree until 1947 due to the ending of the war. However, he was already busy as a free-lance composer in 1946, predominantly for radio. From 1948 to 1950, he was a participant in the Kranichsteiner/Darmstädter Ferienkursen für Neue Musik (lit. Kranichstein/Darmstadt Vacation Course for New Music) where he studied under René Leibowitz and Wolfgang Fortner, among others.  In 1957, he received a scholarship to spend time at the German Academy Villa Massimo in Rome. He also assumed the position of Professor of Composition (from Frank Martin) as well as Film and Broadcast Music at the Cologne Music University. In the 60s, he received more attention and success as a composer (including a second scholarship to the Villa Massimo in 1963 and a fellowship in the Academy of Arts, Berlin), especially after his opera "Die Soldaten" (The Soldiers) finally premiered in 1965. The opera had previously not been performed due to the enormous number of people required and the musical difficulty—the Cologne Opera had considered it "unspielbar" (not performable). The composer's depressive tendencies increased to a more physical level, compounded by a quickly deteriorating eye problem. On 10 August 1970, Zimmermann committed suicide at his home in Königsdorf near Cologne – just five days after completing the score of his last composition, "Ich wandte mich und sah an alles Unrecht das geschah unter der Sonne". At the time, he was preparing another opera, "Medea", after Hans Henny Jahnn.

Music.

In his own compositional growth, he took his place in the progression of new music, from which the German composers were mostly separated during the Nazi regime. He began writing works in the neoclassical style, continued with free atonality and twelve-tone music and eventually arrived at serialism (in 1956). His affection for jazz can sometimes be heard in some of his compositions (more so in his Violin Concerto or Trumpet Concerto).  In contrast to the so-called Darmstadt School (Stockhausen, Boulez, Nono, etc.), Zimmermann did not make a radical break with tradition. At the end of the 1950s, he developed his own personal compositional style, the pluralistic ""Klangkomposition"" (German word referring to the compositional style that focuses on planes – or areas – of sound and tone-colors). The combination and overlapping of layers of musical material from various time periods (from Medieval to Baroque and Classical to Jazz and Pop music) using advanced musical techniques is characteristic of "Klangkomposition". Zimmermann's use of this technique ranged from the embedding of individual musical quotes (seen somewhat in his orchestral work "Photoptosis") to pieces that are built entirely as a collage (the ballet "Musique pour les soupers du Roi Ubu"). In his vocal works, especially his "Requiem for a Young Poet", the text is used to progress the piece by overlapping texts from various sources. He created his own musical stance using the metaphor "the spherical form of time".

Bernd Alois Zimmermann (20 March 1918 – 10 August 1970) was a German composer. He is perhaps best known for his opera "Die Soldaten", which is regarded as one of the most important German operas of the 20th century, after those of Berg. As a result of his individual style, it is hard to label his music as avant-garde, serial or postmodern. His music employs a wide range of methods including the twelve-tone row and musical quotation.


Geography.

Teplice is located in North Bohemia, near the border with the German state of Saxony. It is situated in the valley of the Bílina river between the slopes of the Ore Mountains () in the northwest and the Central Bohemian Uplands ("České středohoří") in the southeast, about west of Ústí nad Labem.  The municipal area comprises the cadastral communities of Teplice proper, Prosetice, Nová Ves, Řetenice, Hudcov, Trnovany, and Sobědruhy.

History.

According to the 1541 "Annales Bohemorum" by chronicler Wenceslaus Hajek, the thermal springs are fabled to have been discovered as early as 762; however, the first authentic mention of the baths occurred in the 16th century. The settlement of Trnovany was first documented in a 1057 deed, while Teplice proper was first mentioned about 1158, when Judith of Thuringia, queen consort of King Vladislaus II of Bohemia, founded a Benedictine nunnery "ad aquas calidas" ("at the hot springs"), the second in Bohemia. A fortified town arose around the monastery, which was destroyed in the course of the Hussite Wars after the 1426 Battle of Aussig. In the late 15th century, queen consort Joanna of Rožmitál, wife of King George of Poděbrady, had a castle erected on the ruins. The name "Teplice" is derived from the Old Czech, meaning "hot spring".  Teplice figures in the history of the Thirty Years' War, when it was a possession of the Protestant Bohemian noble Vilém Kinský, who was assassinated together with Generalissimo Albrecht von Wallenstein at Cheb in 1634. The Habsburg emperor Ferdinand II thereafter enfeoffed castle and town to his general Johann von Aldringen, who nevertheless was killed in battle in the same year, and Teplice fell to his sister Anna Maria von Clary-Aldringen. Consequently, and until 1945, Teplitz Castle was the primarily seat of the princely House of Clary-Aldringen. After the Thirty Years' War, the devastated town was the destination of many German settlers.  After a blaze in 1793, large parts of the town were rebuilt in a Neoclassical style. The health resort was a popular venue for wealthy bourgeois like the poet Johann Gottfried Seume, who died on his stay in 1810, or Ludwig van Beethoven, who met here with Johann Wolfgang von Goethe in 1812; as well as for European monarchs. During the Napoleonic War of the Sixth Coalition, Teplice in August 1813 was the site where Emperor Francis I of Austria, Emperor Alexander I of Russia and King Frederick William III of Prussia first signed the triple alliance against Napoleon I of France that led to the coalition victory at the nearby Battle of Kulm.  In 1895, Teplice merged with neighbouring Lázně Šanov ("Schönau"). Upon the dissolution of Austria-Hungary after World War I and the 1919 Treaty of Saint-Germain-en-Laye, the predominantly German-speaking population found itself in newly established Czechoslovakia. Right-wing political groups like the German National Socialist Worker's Party referred to themselves as "Volksdeutsche" and began to urge for a unification with Germany, their efforts laid the foundation for the rise of the Sudeten German Party under Konrad Henlein after 1933. With the "Sudetenland", Teplice was annexed by Nazi Germany according to the 1938 Munich Agreement and incorporated into "Reichsgau Sudetenland". In 1930, 3,213 Jews lived in Teplice, 10% of the population. Under the Nazi regime they faced the Holocaust in the Sudetenland. Many fled and the Teplice Synagogue was burnt during Kristallnacht.  After World War II the Czechoslovak government enacted the Beneš decrees, whereafter the German-speaking majority of the population was expelled from Teplice. In 1945, the Princes of Clary-Aldringen, lords of Teplice since 1634, were expropriated.  In 1994, Jaroslav Kubera of the Civic Democratic Party (ODS) became mayor of Teplice and he held the position until 2018.

Sports.

Teplice is home to the professional football club FK Teplice playing in the Czech First League. Notable players of the club include Josef Masopust and Pavel Verbíř. The stadium, "Na Stínadlech", is one of the largest in the country and has hosted international matches.

Paleontology.

Fossils of an elasmosaurid plesiosaur (large carnivorous marine reptile from the Cretaceous period) were found near Teplice at the end of the 19th Century. In Hudcov, a nearby village, plesiosaur "Cimoliasaurus teplicensis" was described in 1906 by Czech paleontologist Antonín Frič.

Teplice (), Teplice-Šanov until 1948 (; ), is a statutory city in the Ústí nad Labem Region of the Czech Republic and the capital of the Teplice District. It is Czech Republic's second largest spa town, after Karlovy Vary.


History.

Pierre de Fermat first stated the theorem in a letter dated October 18, 1640, to his friend and confidant Frénicle de Bessy. His formulation is equivalent to the following:  If is a prime and is any integer not divisible by, then is divisible by. Fermat's original statement was This may be translated, with explanations and formulas added in brackets for easier understanding, as:  Every prime number [] divides necessarily one of the powers minus one of any [geometric] progression [] [that is, there exists such that divides ], and the exponent of this power [] divides the given prime minus one [divides ]. After one has found the first power [] that satisfies the question, all those whose exponents are multiples of the exponent of the first one satisfy similarly the question [that is, all multiples of the first have the same property]. Fermat did not consider the case where is a multiple of nor prove his assertion, only stating:  Euler provided the first published proof in 1736, in a paper titled "Theorematum Quorundam ad Numeros Primos Spectantium Demonstratio" in the "Proceedings" of the St. Petersburg Academy, but Leibniz had given virtually the same proof in an unpublished manuscript from sometime before 1683.  The term "Fermat's little theorem" was probably first used in print in 1913 in "Zahlentheorie" by Kurt Hensel:  An early use in English occurs in A.A. Albert's "Modern Higher Algebra" (1937), which refers to "the so-called 'little' Fermat theorem" on page 206.

Further history.

Some mathematicians independently made the related hypothesis (sometimes incorrectly called the Chinese Hypothesis) that if and only if is prime. Indeed, the "if" part is true, and it is a special case of Fermat's little theorem. However, the "only if" part is false: For example,, but 341 = 11 × 31 is a pseudoprime. See below.

Proofs.

Several proofs of Fermat's little theorem are known. It is frequently proved as a corollary of Euler's theorem.

Generalizations.

Euler's theorem is a generalization of Fermat's little theorem: for any modulus formula_3 and any integer coprime to, one has  where formula_5 denotes Euler's totient function (which counts the integers from 1 to that are coprime to ). Fermat's little theorem is indeed a special case, because if formula_3 is a prime number, then formula_7.  A corollary of Euler's theorem is: for every positive integer, if the integer is coprime with then for any integers and. This follows from Euler's theorem, since, if formula_9, then formula_10 for some integer, and one has  If is prime, this is also a corollary of Fermat's little theorem. This is widely used in modular arithmetic, because this allows reducing modular exponentiation with large exponents to exponents smaller than.  If is not prime, this is used in public-key cryptography, typically in the RSA cryptosystem in the following way: if retrieving from the values of and is easy if one knows formula_13 In fact, the extended Euclidean algorithm allows computing the modular inverse of modulo formula_14 that is the integer such formula_15 It follows that On the other hand, if is the product of two distinct prime numbers, then formula_17 In this case, finding from and needs knowing formula_5 (this is not proved, but no algorithm is known for computing without knowing formula_5). If one knows and formula_14 the factors and are easy to deduce, as one knows their product and their sum formula_21 The basic idea of RSA cryptosystem is thus: if a message is encrypted as formula_12 using public values of and, then, with the current knowledge, it cannot be decrypted without finding the (secret) factors and of.  Fermat's little theorem is also related to the Carmichael function and Carmichael's theorem, as well as to Lagrange's theorem in group theory.

Converse.

The converse of Fermat's little theorem is not generally true, as it fails for Carmichael numbers. However, a slightly stronger form of the theorem is true, and it is known as Lehmer's theorem. The theorem is as follows:  If there exists an integer such that and for all primes dividing one has then is prime.  This theorem forms the basis for the Lucas–Lehmer test, an important primality test.

Pseudoprimes.

If and are coprime numbers such that is divisible by, then need not be prime. If it is not, then is called a "(Fermat) pseudoprime" to base. The first pseudoprime to base 2 was found in 1820 by Pierre Frédéric Sarrus: 341 = 11 × 31.  A number that is a Fermat pseudoprime to base for every number coprime to is called a Carmichael number (e.g. 561). Alternately, any number satisfying the equality is either a prime or a Carmichael number.

Miller–Rabin primality test.

The Miller–Rabin primality test uses the following extension of Fermat's little theorem: If is an odd prime number, and, with odd, then for every prime to, either, or there exists such that and  This result may be deduced from Fermat's little theorem by the fact that, if is an odd prime, then the integers modulo form a finite field, in which has exactly two square roots, 1 and −1.  The Miller–Rabin test uses this property in the following way: given, with odd, an odd integer for which primality has to be tested, choose randomly such that ; then compute ; if is not 1 nor −1, then square it repeatedly modulo until you get 1, −1, or have squared times. If and −1 has not been obtained, then is not prime. Otherwise, may be prime or not. If is not prime, the probability that this is proved by the test is higher than 1/4. Therefore, after non-conclusive random tests, the probability that is not prime is lower than, and may thus be made as low as desired, by increasing.  In summary, the test either proves that a number is not prime, or asserts that it is prime with a probability of error that may be chosen as low as desired. The test is very simple to implement and computationally more efficient than all known deterministic tests. Therefore, it is generally used before starting a proof of primality.

Fermat's little theorem states that if is a prime number, then for any integer, the number is an integer multiple of. In the notation of modular arithmetic, this is expressed as


History.

While the non-mammalian animal egg was obvious, the doctrine "ex ovo omne vivum" ("every living [animal comes from] an egg"), associated with William Harvey (1578–1657), was a rejection of spontaneous generation and preformationism as well as a bold assumption that mammals also reproduced via eggs. Karl Ernst von Baer discovered the mammalian ovum in 1827. The fusion of spermatozoa with ova (of a starfish) was observed by Oskar Hertwig in 1876.

Animals.

In animals, egg cells are also known as "ova" (singular "ovum", from the Latin word meaning 'egg'). The term ovule in animals is used for the young ovum of an animal. In vertebrates, ova are produced by female gonads (sexual glands) called ovaries. A number of ova are present at birth in mammals and mature via oogenesis. White et al. disproved the longstanding dogma that all of the ova are produced before birth. The team from the Vincent Center for Reproductive Biology, Massachusetts, Boston showed that oocyte formation takes place in ovaries of reproductive-age women. This report challenged a fundamental belief, held since the 1950s, that female mammals are born with a finite supply of eggs that is depleted throughout life and exhausted at menopause.

Mammals including humans.

In all mammals the ovum is fertilized inside the female body.  The human ova grow from primitive germ cells that are embedded in the substance of the ovaries. Each of them divides repeatedly to give secretions of the uterine glands, ultimately forming a blastocyst.  The ovum is one of the largest cells in the human body, typically visible to the naked eye without the aid of a microscope or other magnification device. The human ovum measures approximately in diameter.

Ooplasm.

Ooplasm (also: oöplasm) is the yolk of the ovum, a cell substance at its center, which contains its nucleus, named the germinal vesicle, and the nucleolus, called the germinal spot.  The ooplasm consists of the cytoplasm of the ordinary animal cell with its spongioplasm and hyaloplasm, often called the "formative yolk"; and the "nutritive yolk" or "deutoplasm", made of rounded granules of fatty and albuminoid substances imbedded in the cytoplasm.  Mammalian ova contain only a tiny amount of the nutritive yolk, for nourishing the embryo in the early stages of its development only. In contrast, bird eggs contain enough to supply the chick with nutriment throughout the whole period of incubation.

Ova development in oviparous animals.

In the oviparous animals (all birds, most fish, amphibians and reptiles) the ova develop protective layers and pass through the oviduct to the outside of the body. They are fertilized by male sperm either inside the female body (as in birds), or outside (as in many fish). After fertilization, an embryo develops, nourished by nutrients contained in the egg. It then hatches from the egg, outside the mother's body. See egg for a discussion of eggs of oviparous animals.  The egg cell's cytoplasm and mitochondria are the sole means the egg can reproduce by mitosis and eventually form a blastocyst after fertilization.

Ovoviviparity.

There is an intermediate form, the ovoviviparous animals: the embryo develops within and is nourished by an egg as in the oviparous case, but then it hatches inside the mother's body shortly before birth, or just after the egg leaves the mother's body. Some fish, reptiles and many invertebrates use this technique.

Plants.

Nearly all land plants have alternating diploid and haploid generations. Gametes are produced by the gametophyte, which is the haploid generation. The female gametophyte produces structures called archegonia, and the egg cells form within them via mitosis. The typical bryophyte archegonium consists of a long neck with a wider base containing the egg cell. Upon maturation, the neck opens to allow sperm cells to swim into the archegonium and fertilize the egg. The resulting zygote then gives rise to an embryo, which will grow into a new diploid individual (sporophyte). In seed plants, a structure called ovule, which contains the female gametophyte. The gametophyte produces an egg cell. After fertilization, the ovule develops into a seed containing the embryo.  In flowering plants, the female gametophyte (sometimes referred to as the embryo sac) has been reduced to just eight cells inside the ovule. The gametophyte cell closest to the micropyle opening of the ovule develops into the egg cell. Upon pollination, a pollen tube delivers sperm into the gametophyte and one sperm nucleus fuses with the egg nucleus. The resulting zygote develops into an embryo inside the ovule. The ovule, in turn, develops into a seed and in many cases, the plant ovary develops into a fruit to facilitate the dispersal of the seeds. Upon germination, the embryo grows into a seedling.  In the moss "Physcomitrella patens", the Polycomb protein FIE is expressed in the unfertilised egg cell (Figure, right) as the blue colour after GUS staining reveals. Soon after fertilisation the FIE gene is inactivated (the blue colour is no longer visible, left) in the young embryo.

Other organisms.

In algae, the egg cell is often called oosphere. "Drosophila" oocytes develop in individual egg chambers that are supported by nurse cells and surrounded by somatic follicle cells. The nurse cells are large polyploid cells that synthesize and transfer RNA, proteins, and organelles to the oocytes. This transfer is followed by the programmed cell death (apoptosis) of the nurse cells. During oogenesis, 15 nurse cells die for every oocyte that is produced. In addition to this developmentally regulated cell death, egg cells may also undergo apoptosis in response to starvation and other insults.

The egg cell, or ovum (plural ova), is the female reproductive cell, or gamete, in most anisogamous organisms (organisms that reproduce sexually with a larger, "female" gamete and a smaller, "male" one). The term is used when the female gamete is not capable of movement (non-motile). If the male gamete (sperm) is capable of movement, the type of sexual reproduction is also classified as oogamous.


History.

In his essay "H. P. Lovecraft and the Cthulhu Mythos", Robert M. Price described two stages in the development of the Cthulhu Mythos. Price called the first stage the "Cthulhu Mythos proper." This stage was formulated during Lovecraft's lifetime and was subject to his guidance. The second stage was guided by August Derleth who, in addition to publishing Lovecraft's stories after his death, attempted to categorize and expand the Mythos.

First stage.

An ongoing theme in Lovecraft's work is the complete irrelevance of mankind in the face of the cosmic horrors that apparently exist in the universe. Lovecraft made frequent references to the "Great Old Ones", a loose pantheon of ancient, powerful deities from space who once ruled the Earth and have since fallen into a deathlike sleep. While these monstrous deities were present in almost all of Lovecraft's published work (his second short story "Dagon", published in 1919, is considered the start of the mythos), the first story to really expand the pantheon of Great Old Ones and its themes is "The Call of Cthulhu", which was published in 1928.  Lovecraft broke with other pulp writers of the time by having his main characters' minds deteriorate when afforded a glimpse of what exists outside their perceived reality. He emphasized the point by stating in the opening sentence of the story that "The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents."  Writer Dirk W. Mosig notes that Lovecraft was a "mechanistic materialist" who embraced the philosophy of "cosmic indifference" (Cosmicism). Lovecraft believed in a purposeless, mechanical, and uncaring universe. Human beings, with their limited faculties, can never fully understand this universe, and the cognitive dissonance caused by this revelation leads to insanity, in his view.  There have been attempts at categorizing this fictional group of beings. Phillip A. Schreffler argues that by carefully scrutinizing Lovecraft's writings, a workable framework emerges that outlines the entire "pantheon"from the unreachable "Outer Ones" (e.g., Azathoth, who occupies the centre of the universe) and "Great Old Ones" (e.g., Cthulhu, imprisoned on Earth in the sunken city of R'lyeh) to the lesser castes (the lowly slave shoggoths and the Mi-go).  David E. Schultz, however, believes that Lovecraft never meant to create a canonical Mythos but rather intended his imaginary pantheon to serve merely as a background element. Lovecraft himself humorously referred to his Mythos as "Yog Sothothery" (Dirk W. Mosig coincidentally suggested the term "Yog-Sothoth Cycle of Myth" be substituted for "Cthulhu Mythos"). At times, Lovecraft even had to remind his readers that his Mythos creations were entirely fictional.  The view that there was no rigid structure is expounded upon by S. T. Joshi, who said Price, however, believed that Lovecraft's writings could at least be divided into categories and identified three distinct themes: the "Dunsanian" (written a similar style as Lord Dunsany), "Arkham" (occurring in Lovecraft's fictionalized New England setting), and "Cthulhu" (the cosmic tales) cycles. Writer Will Murray noted that while Lovecraft often used his fictional pantheon in the stories he ghostwrote for other authors, he reserved Arkham and its environs exclusively for those tales he wrote under his own name.  Although the Mythos was not formalized or acknowledged between them, Lovecraft did correspond and share story elements with other contemporary writers including Clark Ashton Smith, Robert E. Howard, Robert Bloch, Frank Belknap Long, Henry Kuttner, Henry S. Whitehead, and Fritz Leibera group referred to as the "Lovecraft Circle."  For example, Robert E. Howard's character Friedrich Von Junzt reads Lovecraft's "Necronomicon" in the short story "The Children of the Night" (1931), and in turn Lovecraft mentions Howard's "Unaussprechlichen Kulten" in the stories "Out of the Aeons" (1935) and "The Shadow Out of Time" (1936). Many of Howard's original unedited "Conan" stories also involve parts of the Cthulhu Mythos.

Second stage.

Price denotes the second stage's commencement with August Derleth, with the principal difference between Lovecraft and Derleth being Derleth's use of hope and development of the idea that the Cthulhu mythos essentially represented a struggle between good and evil. Derleth is credited with creating the "Elder Gods." He stated:  Price believes that the basis for Derleth's system is found in Lovecraft: "Was Derleth's use of the rubric 'Elder Gods' so alien to Lovecraft's in "At the Mountains of Madness"? Perhaps not. In fact, this very story, along with some hints from "The Shadow over Innsmouth", provides the key to the origin of the 'Derleth Mythos'. For in "At the Mountains of Madness" is shown the history of a conflict between interstellar races, first among them the Elder Ones and the Cthulhu-spawn.  Derleth himself believed that Lovecraft wished for other authors to actively write about the Mythos as opposed to it being a discrete plot device within Lovecraft's own stories. Derleth expanded the boundaries of the Mythos by including any passing reference to another author's story elements by Lovecraft as part of the genre. Just as Lovecraft made passing reference to Clark Ashton Smith's "Book of Eibon", Derleth in turn added Smith's Ubbo-Sathla to the Mythos.  Derleth also attempted to connect the deities of the Mythos to the four elements ("air", "earth", "fire", and "water"), creating new beings representative of certain elements in order to legitimize his system of classification. Derleth created "Cthugha" as a sort of fire elemental when a fan, Francis Towner Laney, complained that he had neglected to include the element in his schema. Laney, the editor of "The Acolyte", had categorized the Mythos in an essay that first appeared in the Winter 1942 issue of the magazine.  Impressed by the glossary, Derleth asked Laney to rewrite it for publication in the Arkham House collection "Beyond the Wall of Sleep" (1943). Laney's essay ("The Cthulhu Mythos") was later republished in "Crypt of Cthulhu #32" (1985). In applying the elemental theory to beings that function on a cosmic scale (e.g., Yog-Sothoth) some authors created a fifth element that they termed "aethyr".

The Cthulhu Mythos is a shared fictional universe, originating in the works of American horror writer H. P. Lovecraft. The term was coined by August Derleth, a contemporary correspondent and protégé of Lovecraft, to identify the settings, tropes, and lore that were employed by Lovecraft and his literary successors. The name "Cthulhu" derives from the central creature in Lovecraft's seminal short story, "The Call of Cthulhu", first published in the pulp magazine "Weird Tales" in 1928.


Early life.

Brody was born in Woodhaven, Queens, New York City, the son of Sylvia Plachy, a photographer, and Elliot Brody, a retired history professor and painter. Brody's father is of Polish Jewish descent; Brody's mother, who was raised as a Catholic, was born in Budapest, Hungary, and is the daughter of a Catholic Hungarian aristocrat father and a Czech Jewish mother. Brody was raised "without a strong connection" to either Judaism or Catholicism.  As a child, Brody performed magic shows at children's birthday parties as "The Amazing Adrien". He attended I.S. 227 Louis Armstrong Middle School and New York's Fiorello H. LaGuardia High School of Music & Art and Performing Arts. His parents enrolled him in acting classes to distance him from the dangerous children with whom he associated. He attended summer camp at Long Lake Camp for the Arts in the Adirondacks in upstate New York. Brody attended Stony Brook University before transferring to Queens College for a semester.

Career.

Taking acting classes as a child, by age thirteen, he appeared in an Off-Broadway play and a PBS television film. After appearing in "Bullet" in 1996 with Tupac Shakur and Mickey Rourke, Brody hovered on the brink of stardom, receiving an Independent Spirit Award nomination for his role in the 1998 film "Restaurant", and later praise for his roles in Spike Lee's "Summer of Sam" and Terrence Malick's "The Thin Red Line". He received widespread recognition when he was cast as the lead in Roman Polanski's "The Pianist" (2002). To prepare for the role, Brody withdrew for months, gave up his apartment and his car, broke up with his then-girlfriend, learned how to play Chopin on the piano, he is 6'1" (1.85m) and lost thirty pounds (13.6 kg) dropping him to 130 lbs (59 kg). The role won him an Academy Award for Best Actor, making him, at age twenty nine, the youngest actor ever to win the award, and to date the only winner under the age of thirty. He also won a César Award for his performance.  Brody appeared on "Saturday Night Live" on May 10, 2003, his first TV work, during which he controversially gave an improvised introduction, while wearing faux dreadlocks and a Jamaican accent for Jamaican reggae musical guest Sean Paul (without Lorne Michaels' permission), causing him to be banned. Other TV appearances include NBC's "The Today Show", and on MTV's "Punk'd" after being tricked by Ashton Kutcher.  After "The Pianist", Brody appeared in four very different films. In "Dummy" (released in 2003, but originally shot in 2000, just prior to his work in "The Pianist"), he portrayed Steven Schoichet, a socially awkward aspiring ventriloquist in pursuit of a love interest (his employment counsellor). He learned ventriloquism and puppetry for the role (under the tutelage of actor/ventriloquist Alan Semok) convincingly enough to perform all of the voice stunts and puppet manipulation live on set in real time, with no subsequent post dubbing. He played Noah Percy, a mentally disabled young man, in the film "The Village", by M. Night Shyamalan, shell-shocked war veteran Jack Starks in "The Jacket", writer Jack Driscoll in the 2005 "King Kong" remake, and father-to-be Peter Whitman in "The Darjeeling Limited" by Wes Anderson. "King Kong" was both a critical and box office success – it grossed $550 million worldwide, and is Brody's most successful film to date in monetary terms. He also voiced Jack Driscoll in the video game adaptation. Additionally, Brody played a detective in "Hollywoodland". He has also appeared in Diet Coke and Schweppes commercials, as well as Tori Amos' music video for "A Sorta Fairytale".  On January 5, 2006, Brody confirmed speculation that he was interested in playing the role of The Joker in 2008's "The Dark Knight". However, Christopher Nolan and Warner Bros. decided instead to cast Heath Ledger in the role. He was also in talks with Paramount to play Spock in J. J. Abrams "Star Trek XI", but it ultimately went to Zachary Quinto. In 2009, he starred in "Splice", a science fiction film written and directed by Vincenzo Natali. Originally a Sundance film, "Splice" was adopted by Dark Castle Entertainment and distributed by Warner Bros. In 2010, he played the star role of Royce in "Predators" (a sequel to the original "Predator"), directed by Nimród Antal and produced by Robert Rodriguez.  In 2011, Brody starred in a Stella Artois beer ad called "Crying Jean" that premiered right after half-time of the Super Bowl XLV as part of Stella's "She Is a Thing of Beauty" campaign. He appeared in Woody Allen's 2011 Academy Award-winning comedy "Midnight in Paris" as Salvador Dalí. On January 16, 2012, Brody made his debut as a runway model for Prada Men Fall/Winter 2012 show.  In 2014, Brody collaborated again with Wes Anderson in the Academy Award-winning "The Grand Budapest Hotel", where he played Dmitri. He received an Emmy nomination for Outstanding Lead Actor in a Miniseries or in a Movie for portraying the titular character in "Houdini", a History channel miniseries. The following year, he starred as Tiberius in the Chinese film "Dragon Blade", which grossed $54.8 million in its opening week in China.  In 2017, it was announced he would join the cast of the fourth season of the BBC crime drama "Peaky Blinders".  On August 4, 2017, he received the Leopard Club Award at the Locarno Festival. The Leopard Club Award pays homage to a major film personality whose work has made a lasting impact on the collective imagination.

Personal life.

In 1992, Brody was seriously hurt in a motorcycle accident in which he flew over a car and crashed head-first into a crosswalk. He spent months recuperating. He has broken his nose three times doing stunts; the most recent was during the filming of "Summer of Sam".  He dated Michelle Dupont, a music industry personal assistant, from 2003 to 2006. She was his date to the 2003 Oscars.  Brody began dating Spanish actress Elsa Pataky in 2006. For Pataky's 31st birthday in July 2007, Brody purchased her a 19th-century farm in Central New York state that was remodeled to look like a castle. Brody and Pataky were featured at their New York home in a 35-page spread for "HELLO!" magazine in October 2008. The pair broke up in 2009.  In 2010, Brody sued the "Giallo" filmmakers, alleging that they failed to pay his full salary.  In February 2020 it was reported that he was dating Georgina Chapman.

Oscar kiss controversy.

At the 75th Academy Awards in 2003, Brody forcibly kissed actress Halle Berry, who had been presenting him with the Oscar for Best Actor for his work in "The Pianist". In a 2017 interview with Andy Cohen, Berry confirmed that the kiss was unplanned, stating "I knew nothing about it." USA Today has since called the moment "cringeworthy," particularly "in light of the sexual harassment allegations that have rocked Hollywood". Good Housekeeping has ranked it among the biggest scandals in Oscar history.

Adrien Brody (born April 14, 1973) is an American actor and producer. He received widespread recognition and acclaim after starring in Roman Polanski's "The Pianist" (2002), for which he won the Academy Award for Best Actor at age twenty-nine, making him the youngest actor to win in that category. Brody is the second male American actor (after Christopher Lambert) to receive the César Award for Best Actor.


Overview.

A team of human scientists is probing and examining the oceanic surface of the planet Solaris from a hovering research station. Solaris manifests an ability to cast their secret, guilty concerns into a material form for each scientist to personally confront. All human efforts to make sense of Solaris' activities ultimately prove futile. As Lem wrote, "The peculiarity of those phenomena seems to suggest that we observe a kind of rational activity, but the meaning of this seemingly rational activity of the Solarian Ocean is beyond the reach of human beings". He also wrote that he deliberately chose the ocean as a sentient alien to avoid any personification and the pitfalls of anthropomorphism in depicting first contact.  The novel was first published in Warsaw in 1961. The 1970 Polish-to-French-to-English translation of "Solaris" is the best-known of Lem's English-translated works. It has been adapted for the screen in 1968, 1972, and 2002.

Plot summary.

"Solaris" chronicles the ultimate futility of attempted communications with the extraterrestrial life inhabiting a distant alien planet named Solaris. The planet is almost completely covered with an ocean of gel that is revealed to be a single, planet-encompassing entity. Terran scientists conjecture it is a living and a sentient being, and attempt to communicate with it.  Kris Kelvin, a psychologist, arrives aboard Solaris Station, a scientific research station hovering near the oceanic surface of Solaris. The scientists there have studied the planet and its ocean for many decades, mostly in vain. A scientific discipline known as Solaristics has degenerated over the years to simply observing, recording and categorizing the complex phenomena that occur upon the surface of the ocean. Thus far, the scientists have only compiled an elaborate nomenclature of the phenomena, and do not yet understand what such activities really mean. Shortly before Kelvin's arrival, the crew exposed the ocean to a more aggressive and unauthorized experimentation with a high-energy X-ray bombardment. Their experimentation gives unexpected results and becomes psychologically traumatic for them as individually flawed humans.  The ocean's response to this intrusion exposes the deeper, hidden aspects of the personalities of the human scientists, while revealing nothing of the ocean's nature itself. It does this by materializing physical simulacra, including human ones; Kelvin confronts memories of his dead lover and guilt about her suicide. The "guests" of the other researchers are only alluded to.

Criticism and interpretations.

In an interview, Lem said that the novel "has always been a juicy prey for critics", with interpretations ranging from that of Freudism to anticommunism, the latter stating that the Ocean represents the USSR and the people on the space station represent the Soviet satellites. He also commented on the absurdity of the book cover blurb for the 1976 edition, which said the novel "expressed the humanistic beliefs of the author about high moral qualities of the human". Lem noted that the critic who promulgated the Freudian idea actually blundered by basing his psychoanalysis on dialogue from the English translation, whereas his diagnosis would fail on the idioms in the original Polish text.

English translation.

Both the original Polish version of the novel (published in 1961) and its English translation are titled "Solaris". Jean-Michel Jasiensko published his French translation in 1964 and that version was the basis of Joanna Kilmartin and Steve Cox's English translation in 1970 (published by Walker & Co., and republished many times since).  Lem, who read English fluently, repeatedly voiced his disappointment with the Kilmartin–Cox version, and it has generally been considered second-rate. In 2011 Bill Johnston completed an English translation. Lem's wife and son reviewed this version more favorably: “We are very content with Professor Johnston's work, that seems to have captured the spirit of the original.” It was released as an audio book and later in an Amazon Kindle edition (2014, ). Legal issues have prevented this translation from appearing in print.

Adaptations.

Cinema.

"Solaris" has been filmed three times:  Lem himself observed that none of the film versions depict much of the extraordinary physical and psychological "alienness" of the Solaris ocean. Responding to film reviews of Soderbergh's version, Lem, noting that he did not see the film, wrote:

Solaris is a 1961 philosophical science fiction novel by Polish writer Stanisław Lem. Its central theme is the complete failure of human beings to understand an extraterrestrial intelligence.


Life and work.

Born in Munich, Klaus Mann was the son of German writer Thomas Mann and his wife, Katia Pringsheim. His father was baptized as a Lutheran, while his mother was from a family of secular Jews. He began writing short stories in 1924 and the following year became drama critic for a Berlin newspaper. His first literary works were published in 1925.  Mann's early life was troubled. His homosexuality often made him the target of bigotry, and he had a difficult relationship with his father. After only a short time in various schools, he travelled with his sister Erika Mann, a year older than himself, around the world, visiting the US in 1927; they reported on the trip in essays published as a collaborative travelogue entitled "Rundherum" in 1929.  In 1924 he had become engaged to his childhood friend Pamela Wedekind, the eldest daughter of the playwright Frank Wedekind, who was also a close friend of his sister Erika. The engagement was broken off in January 1928.  He travelled with Erika to North Africa in 1929. Around this time they made the acquaintance of Annemarie Schwarzenbach, a Swiss writer and photographer, who remained close to them for the next few years. Klaus made several trips abroad with Annemarie, the final one to a Soviet writers' congress in Moscow in 1934.  Since his young adulthood, Klaus was using drugs, mostly opiates, to which he later became heavily addicted. His diaries document an attempted morphine-injection in 1933 when Hitler took power. Initially, the aspiring writer used opium, Eukodal and later heroin to possibly increase his creative energy, as this was often the case for artists and intellectuals in literary circles at the time. He underwent drug detoxification in Budapest during his frantic travels and at the Kilchberg Sanatorium in Switzerland. After 1936, his drug use and sexual escapades became excessive during his stay in New York.  In 1932 Klaus wrote the first part of his autobiography, which was well received until Hitler came to power.  In 1933 Klaus participated with Erika in a political cabaret, called "Die Pfeffermühle" ("The Pepper-Mill"), which came to the attention of the Nazi regime. To escape prosecution he left Germany in March 1933 for Paris, later visiting Amsterdam and Switzerland, where his family had a house. Also in 1933, Klaus Mann and Annemarie Schwarzenbach, together with Fritz Landshoff and Dutch publisher Emanuel Querido, founded "Die Sammlung", a literary magazine, first published in September 1933 in Amsterdam. It was primarily affiliated with a number of influential German writers who fled from the Hitler regime during the first years of the establishment and consolidation of Nazi rule. The magazine was funded by the wealthy Annemarie Schwarzenbach, and Klaus Mann served as its editor-in-chief from 1933 to 1935, when "Die Sammlung"'s activity ceased.  Klaus Mann not only played an important role in the consolidation of the German "Exilliteratur" but also communicated with authors who remained in Germany after 1933. In a letter exchange with Gottfried Benn, whose ambivalence towards Nazi rule was well known, Klaus expressed concern about his continued membership in the national German academy of writers, pointing out the moral dilemma it posed, even urging him to leave the country to join the German intellectuals in exile.  In November 1934 Klaus was stripped of German citizenship by the Nazi regime. He became a Czechoslovak citizen. In 1936, he moved to the United States, living in Princeton, New Jersey, and New York. In the summer of 1937, he met his partner for the rest of the year Thomas Quinn Curtiss, who was later a longtime film and theater reviewer for "Variety" and the "International Herald Tribune". In 1940 Klaus Mann founded another literary magazine for German writers living in exile in the United States, "Decision". It lasted for only a year. During that time, he also lived at his father's house in Pacific Palisades when he was unable to support himself financially.  Mann became a US citizen in 1943. The process of naturalization was delayed because of an investigation the FBI conducted into Klaus Mann's political and sexual activities; he was openly gay but not an adherent of marxist ideologies. Throughout his life in the US, he identified himself as a liberal antifascist and cosmopolitan. In World War II, he served as a Staff Sergeant of the 5th US Army in Italy. In summer 1945, he was sent by the "Stars and Stripes" to report from Postwar-Germany.  Mann's most famous novel, "Mephisto", was written in 1936 and first published in Amsterdam. The novel is a thinly-disguised portrait of his former brother-in-law, the actor Gustaf Gründgens. The literary scandal surrounding it made Mann posthumously famous in West Germany, as Gründgens' adopted son brought a legal case to have the novel banned after its first publication in West Germany in the early 1960s. After seven years of legal hearings, the West German Supreme Court banned it by a vote of three to three, although it continued to be available in East Germany and abroad. The ban was lifted and the novel published in West Germany in 1981.  Mann's novel "Der Vulkan" is one of the 20th century's most famous novels about German exiles during World War II.  He died in Cannes of an overdose of sleeping pills on 21 May 1949, after another drug treatment. The prolific writer likely committed suicide because of financial problems and social isolation. He was buried there in the Cimetière du Grand Jas.

Klaus Heinrich Thomas Mann (18 November 1906 – 21 May 1949) was a German-born American writer and dissident. He was the brother of Erika Mann, with whom he maintained a lifelong close relationship. He is well known for his 1936 novel, "Mephisto".


Sovereign credit ratings.

A sovereign credit rating is the credit rating of a sovereign entity, such as a national government. The sovereign credit rating indicates the risk level of the investing environment of a country and is used by investors when looking to invest in particular jurisdictions, and also takes into account political risk.  The "country risk rankings" table shows the ten least-risky countries for investment. Ratings are further broken down into components including political risk, economic risk. Euromoney's bi-annual country risk index monitors the political and economic stability of 185 sovereign countries. Results focus foremost on economics, specifically sovereign default risk or payment default risk for exporters (also known as a trade credit risk).  A. M. Best defines "country risk" as the risk that country-specific factors could adversely affect an insurer's ability to meet its financial obligations.

Short- and long-term ratings.

A rating expresses the likelihood that the rated party will go into default within a given time horizon. In general, a time horizon of one year or under is considered short term, and anything above that is considered long term. In the past institutional investors preferred to consider long-term ratings. Nowadays, short-term ratings are commonly used.

Corporate credit ratings.

Credit ratings can address a corporation's financial instruments i.e. debt security such as a bond, but also the corporations itself. Ratings are assigned by credit rating agencies, the largest of which are Standard & Poor's, Moody's and Fitch Ratings. They use letter designations such as A, B, C. Higher grades are intended to represent a lower probability of default.  Agencies do not attach a hard number of probability of default to each grade, preferring descriptive definitions such as: "the obligor's capacity to meet its financial commitment on the obligation is extremely strong," or "less vulnerable to non-payment than other speculative issues..." (Standard and Poors' definition of an AAA-rated and a BB-rated bond respectively). However, some studies have estimated the average risk and reward of bonds by rating. One study by Moody's claimed that over a "5-year time horizon" bonds it gave its highest rating (Aaa) to had a "cumulative default rate" of 0.18%, the next highest (Aa2) 0.28%, the next (Baa2) 2.11%, 8.82% for the next (Ba2), and 31.24% for the lowest it studied (B2). (See "Default rate" in "Estimated spreads and default rates by rating grade" table to right.) Over a longer period, it stated "the order is by and large, but not exactly, preserved". Another study in "Journal of Finance" calculated the additional interest rate or "spread" corporate bonds pay over that of "riskless" US Treasury bonds, according to the bonds' rating. (See "Basis point spread" in table to right.) Looking at rated bonds for 1973–89, the authors found a AAA-rated bond paid 43 "basis points" (or 43/100 of a percentage point) over a US Treasury bond (so that it would yield 3.43% if the Treasury yielded 3.00%). A CCC-rated "junk" (or speculative) bond, on the other hand, paid over 7% (724 basis points) more than a Treasury bond on average over that period.  Different rating agencies may use variations of an alphabetical combination of lowercase and uppercase letters, with either plus or minus signs or numbers added to further fine-tune the rating (see colored chart). The Standard & Poor's rating scale uses uppercase letters and pluses and minuses. The Moody's rating system uses numbers and lowercase letters as well as uppercase.  While Moody's, S&P and Fitch Ratings control approximately 95% of the credit ratings business, they are not the only rating agencies. DBRS's long-term ratings scale is somewhat similar to Standard & Poor's and Fitch Ratings with the words high and low replacing the + and −. It goes as follows, from excellent to poor: AAA, AA (high), AA, AA (low), A (high), A, A (low), BBB (high), BBB, BBB (low), BB (high), BB, BB (low), B (high), B, B (low), CCC (high), CCC, CCC (low), CC (high), CC, CC (low), C (high), C, C (low) and D. The short-term ratings often map to long-term ratings though there is room for exceptions at the high or low side of each equivalent.  S&P, Moody's, Fitch and DBRS are the only four ratings agencies that are recognized by the European Central Bank (ECB) for determining collateral requirements for banks to borrow from the central bank. The ECB uses a first, best rule among the four agencies that have the designated ECAI status, which means that it takes the highest rating among the four agencies – S&P, Moody's, Fitch and DBRS – to determine haircuts and collateral requirements for borrowing. Ratings in Europe have been under close scrutiny, particularly the highest ratings given to countries like Spain, Ireland and Italy, because they affect how much banks can borrow against sovereign debt they hold.  A. M. Best rates from excellent to poor in the following manner: A++, A+, A, A−, B++, B+, B, B−, C++, C+, C, C−, D, E, F, and S. The CTRISKS rating system is as follows: CT3A, CT2A, CT1A, CT3B, CT2B, CT1B, CT3C, CT2C and CT1C. All these CTRISKS grades are mapped to one-year probability of default.  Under the EU Credit Rating Agency Regulation (CRAR), the European Banking Authority has developed a series of mapping tables that map ratings to the "Credit Quality Steps" (CQS) as set out in regulatory capital rules and map the CQS to short run and long run benchmark default rates. These are provided in the table below:

See also.

Individuals:

A credit rating is an evaluation of the credit risk of a prospective debtor (an individual, a business, company or a government), predicting their ability to pay back the debt, and an implicit forecast of the likelihood of the debtor defaulting. The credit rating represents an evaluation of a credit rating agency of the qualitative and quantitative information for the prospective debtor, including information provided by the prospective debtor and other non-public information obtained by the credit rating agency's analysts.


History.

The phrase "Rights for Civil" is a translation of Latin "jus civis" (rights of a citizen). Roman citizens could be either free ("libertas") or servile ("servitus"), but they all had rights in law. After the Edict of Milan in 313, these rights included the freedom of religion; however in 380, the Edict of Thessalonica required all subjects of the Roman Empire to profess Catholic Christianity. Roman legal doctrine was lost during the Middle Ages, but claims of universal rights could still be made based on Christian doctrine. According to the leaders of Kett's Rebellion (1549), "all bond men may be made free, for God made all free with his precious blood-shedding."  In the 17th century, English common law judge Sir Edward Coke revived the idea of rights based on citizenship by arguing that Englishmen had historically enjoyed such rights. The Parliament of England adopted the English Bill of Rights in 1689. It was one of the influences drawn on by George Mason and James Madison when drafting the Virginia Declaration of Rights in 1776. The Virginia declaration is the direct ancestor and model for the U.S. Bill of Rights (1789).  The removal by legislation of a civil right constitutes a "civil disability". In early 19th century Britain, the phrase "civil rights" most commonly referred to the issue of such legal discrimination against Catholics. In the House of Commons support for civil rights was divided, with many politicians agreeing with the existing civil disabilities of Catholics. The Roman Catholic Relief Act 1829 restored their civil rights.  In the 1860s, Americans adapted this usage to newly freed blacks. Congress enacted civil rights acts in 1866, 1871, 1875, 1957, 1960, 1964, 1968, and 1991.

Protection of rights.

T. H. Marshall notes that civil rights were among the first to be recognized and codified, followed later by political rights and still later by social rights. In many countries, they are constitutional rights and are included in a bill of rights or similar document. They are also defined in international human rights instruments, such as the 1948 Universal Declaration of Human Rights and the 1967 International Covenant on Civil and Political Rights.  Civil and political rights need not be codified to be protected. However, most democracies worldwide do have formal written guarantees of civil and political rights. Civil rights are considered to be natural rights. Thomas Jefferson wrote in his "A Summary View of the Rights of British America" that "a free people [claim] their rights as derived from the laws of nature, and not as the gift of their chief magistrate."  The question of to whom civil and political rights apply is a subject of controversy. Although in many countries citizens have greater protections against infringement of rights than non-citizens, civil and political rights are generally considered to be universal rights that apply to all persons.  According to political scientist Salvador Santino F. Regilme Jr., analyzing the causes of and lack of protection from human rights abuses in the Global South should be focusing on the interactions of domestic and international factors—an important perspective that has usually been systematically neglected in the social science literature.

Other rights.

Custom also plays a role. Implied or unenumerated rights are rights that courts may find to exist even though not expressly guaranteed by written law or custom; one example is the right to privacy in the United States, and the Ninth Amendment explicitly shows that there are other rights that are also protected.  The United States Declaration of Independence states that people have unalienable rights including "Life, Liberty and the pursuit of Happiness". It is considered by some that the sole purpose of government is the protection of life, liberty and property.  Ideas of self-ownership and cognitive liberty affirm rights to choose the food one eats, the medicine one takes, the habit one indulges.

Social movements for civil rights.

Civil rights guarantee equal protection under the law. When civil and political rights are not guaranteed to all as part of equal protection of laws, or when such guarantees exist on paper but are not respected in practice, opposition, legal action and even social unrest may ensue.  Civil rights movements in the United States gathered steam by 1848 with such documents as the Declaration of Sentiment. Consciously modeled after the Declaration of Independence, the Declaration of Rights and Sentiments became the founding document of the American women's movement, and it was adopted at the Seneca Falls Convention, July 19 and 20, 1848.  Worldwide, several political movements for equality before the law occurred between approximately 1950 and 1980. These movements had a legal and constitutional aspect, and resulted in much law-making at both national and international levels. They also had an activist side, particularly in situations where violations of rights were widespread. Movements with the proclaimed aim of securing observance of civil and political rights included:  Most civil rights movements relied on the technique of civil resistance, using nonviolent methods to achieve their aims. In some countries, struggles for civil rights were accompanied, or followed, by civil unrest and even armed rebellion. While civil rights movements over the last sixty years have resulted in an extension of civil and political rights, the process was long and tenuous in many countries, and many of these movements did not achieve or fully achieve their objectives.

Problems and analysis.

Questions about civil and political rights have frequently emerged. For example, to what extent should the government intervene to protect individuals from infringement on their rights by other individuals, or from corporations—e.g., in what way should employment discrimination in the private sector be dealt with?  Political theory deals with civil and political rights. Robert Nozick and John Rawls expressed competing visions in Nozick's "Anarchy, State, and Utopia" and Rawls' "A Theory of Justice". Other influential authors in the area include Wesley Newcomb Hohfeld, and Jean Edward Smith.

First-generation rights.

First-generation rights, often called "blue" rights, deal essentially with liberty and participation in political life. They are fundamentally civil and political in nature, as well as strongly individualistic: They serve negatively to protect the individual from excesses of the state. First-generation rights include, among other things, freedom of speech, the right to a fair trial, (in some countries) the right to keep and bear arms, freedom of religion, freedom from discrimination, and voting rights. They were pioneered in the United States by the Bill of Rights and in France by the Declaration of the Rights of Man and of the Citizen in the 18th century, although some of these rights and the right to due process date back to the Magna Carta of 1215 and the Rights of Englishmen, which were expressed in the English Bill of Rights in 1689.  They were enshrined at the global level and given status in international law first by Articles 3 to 21 of the 1948 Universal Declaration of Human Rights and later in the 1966 International Covenant on Civil and Political Rights. In Europe, they were enshrined in the European Convention on Human Rights in 1953.

Civil and political rights are a class of rights that protect individuals' freedom from infringement by governments, social organizations, and private individuals. They ensure one's entitlement to participate in the civil and political life of society and the state without discrimination or repression.


Development.

The concept of a flywheel-powered bus was developed and brought to fruition during the 1940s by Oerlikon (of Switzerland), with the intention of creating an alternative to battery-electric buses for quieter, lower-frequency routes, where full overhead-wire electrification could not be justified. Rather than carrying an internal combustion engine or batteries, or connecting to overhead powerlines, a gyrobus carries a large flywheel that is spun at up to 3,000 RPM by a "squirrel cage" motor. Power for charging the flywheel was sourced by means of three booms mounted on the vehicle's roof, which contacted charging points located as required or where appropriate (at passenger stops en route, or at terminals, for instance). To obtain tractive power, capacitors would excite the flywheel's charging motor so that it became a generator, in this way transforming the energy stored in the flywheel back into electricity. Vehicle braking was electric, and some of the energy was recycled back into the flywheel, thereby extending its range.  Fully charged, a gyrobus could typically travel as far as on a level route at speeds of up to, depending on vehicle batch (load), as top speeds varied from batch to batch. The installation in Yverdon-les-Bains (Switzerland) sometimes saw vehicles needing to travel as far as on one charge, although it is not known how well they performed towards the upper end of that distance.  Charging a flywheel took between 30 seconds and 3 minutes; in an effort to reduce the charge time, the supply voltage was increased from 380 volts to 500 volts. Given the relatively restricted range between charges, it is likely that several charging stops would have been required on longer routes, or in dense urban traffic. It is not clear whether vehicles that require such frequent delays would have been practical and/or suitable for modern-day service applications.  The demonstrator was first displayed (and used) publicly in summer 1950 and, to promote the system, this vehicle continued to be used for short periods of public service in a myriad of locations at least until 1954.  In 1979, General Electric was awarded a $5 million four-year contract by the United States government, the Department of Energy and the Department of Transportation, to develop a prototype flywheel bus.  In the 1980s, Volvo briefly experimented with using flywheels charged by a small diesel engine and recharged via braking energy. This was eventually dumped in favour of using hydraulic accumulators.  During the 1990s, the Dutch Centre for Concepts in Mechatronics had developed a flywheel for both mobile and stationary applications.  In 2005, the Center for Transportation and the Environment, working with the University of Texas at Austin, Center for Electromechanics, Test Devices, Inc., and DRS Technologies sought funding for the development of a prototype gyrobus.

Early commercial service.

The first full commercial service began in October 1953, linking the Swiss communities of Yverdon-les-Bains and Grandson. However, this was a route with limited traffic potential, and although technically successful it was not commercially viable. Services ended in late October 1960, and neither of the two vehicles (nor the demonstrator) survived.  The next system to open was in Léopoldville in Belgian Congo (now Kinshasa in the Democratic Republic of the Congo). Here there were 12 vehicles (although apparently some reports suggest 17), which operated over four routes, with recharging facilities being provided about every. These were the largest of the gyrobuses, being in length, weighing, carrying up to 90 passengers, and having a maximum speed of. There were major problems related to excessive "wear and tear". One significant reason for this was that drivers often took shortcuts across unpaved roads, which after rains became nothing more than quagmires. Other problems included breakage of gyro ball bearings, and high humidity resulting in traction motor overload. The system's demise, however, came because of high energy consumption. The bus operator deemed that 3.4 kWh/km per gyrobus was unaffordable, so closure came in the summer of 1959 with the gyrobuses being abandoned and replaced with diesel buses.  The third location to use gyrobuses commercially was Ghent, Belgium. Three gyrobuses started operation in late summer 1956 on a route linking Ghent and Merelbeke. The flywheel was in the center of the bus, spanning almost the whole width of the vehicle, and having a vertical axis of rotation. The Ghent to Merelbeke route was intended to be the first of a proposed multi-route network; instead, its gyrobuses stayed in service for only three years, being withdrawn late autumn 1959. The operator considered them unreliable, "spending more time off the road than on", and that their weight damaged road surfaces. They were also considered to be energy hungry, consuming 2.9 kWh/km—compared with between 2.0 kWh/km and 2.4 kWh/km for trams with much greater capacity.  One of Ghent's gyrobuses has been preserved and restored, and is displayed at the VLATAM-museum in Antwerp. It is sometimes shown (and used to carry passengers) at Belgian exhibitions, transport enthusiasts' bazaars, etc. The tram depot in Merelbeke has been closed since 1998, but it still stands, as it is protected by the law.

Further developments.

After the gyrobus was discontinued in all locations, there have been a number of attempts to make the concept work. Recently, there have been two successful projects, though the original idea of storing energy has been changed considerably: In Dresden, Germany there is the Autotram, a vehicle that looks like a modern tram, but moves on a flat surface, not on tracks. It has run since 2005 and is powered by a flywheel, though the wheel is small and only used to store energy from braking. The main source of energy is a fuel cell.

A gyrobus is an electric bus that uses flywheel energy storage, not overhead wires like a trolleybus. The name comes from the Greek language term for flywheel, "gyros". While there are no gyrobuses currently in use commercially, development in this area continues.


History.

The EUROCONTROL Convention was signed in 1960 and ratified in 1963. Before the Convention entered into force in 1963, there were already indications that the matter of national sovereignty would complicate the full implementation of the organisation's founding mission. The first European plan for a harmonised air traffic control (ATC) system, proposed in 1962, was beset by the refusal of both France and Britain to comply, largely due to reasons closely linked with their national military airspace control. The other four original members (the Federal Republic of Germany, Belgium, the Netherlands and Luxembourg) agreed in 1964 to set up a single international air traffic control centre to manage their upper airspace, settling in the Dutch city of Maastricht.  The European Parliament at the time expressed concern about the lack of clear intergovernmental agreements to ensure common air traffic control services across the continent. In 1979, EUROCONTROL signed a working cooperation agreement with the European Commission, attempting to create a synergy of EUROCONTROL's technical expertise and EU's regulatory authorities. Several initiatives originating in this period become a lasting element of the organisation, such as the EUROCONTROL forecasting service, which became STATFOR, as well as the Aeronautical Information Service. By 1986, the pressures on the European ATC network was so big that a new, wider mandate was already being considered for EUROCONTROL, with much of the initiative coming from ECAC’s Ministers of Transport. Subsequently, ECAC urged all of its member states to join EUROCONTROL.  A revised EUROCONTROL Convention was signed in 1997, renewing the organisation's optimism for greater political support, surpassing the original vision of the 1960 Convention. In June 1998, Eurocontrol, the European Space Agency (ESA) and the European Commission (EC) also signed an agreement formalising cooperation in the realm of satellite navigation systems and services. In 1999 the European Commission presented its plan for a Single European Sky (SES) to the European Parliament, followed by two High Level Groups (HLG). The HLG reports on SES led to the establishment of the European Aviation Safety Agency (EASA) and reinforced the European Commission's role as the sole European aviation safety regulator, while acknowledging EUROCONTROL's technical expertise in the implementation of said regulations.  The early 2000s were marred by several fatal accidents in Europe, such as the 2001 Linate Airport disaster and the 2002 Überlingen mid-air collision, both of which were related to air traffic navigation shortcomings. The pressure was further compounded by the September 11 attacks, increasing the need for a rapid Europe-wide regulatory and coordinating body. By May 2003, EUROCONTROL and NATO had signed a memorandum of cooperation, followed by a similar memorandum with the European Commission in December 2003. In February 2004, EUROCONTROL started work on first mandates from the European Commission and in April 2004, it adopted the Single European Sky Regulations (Package 1). In March 2006, the European Commission's Single European Sky ATM Research (SESAR) Program was launched by the Stakeholder Consultation Group (SCG) under EUROCONTROL's aegis.

Functions and centres.

EUROCONTROL provides a set of different services:

Maastricht Upper Area Control Centre.

EUROCONTROL's Maastricht Upper Area Control Centre (MUAC), ICAO designator EDYY, located at Maastricht Aachen Airport, provides air traffic control for traffic above 24,500 ft over Belgium, Luxembourg, the Netherlands, and north-west Germany. In 2017 it became the first multinational, cross-border civil-military air navigation service provider since it integrated the military air traffic control of the German and Dutch upper airspace.  It is the third busiest upper area Area Control Centre (ACC) in Europe after the London Area Control Centre and Karlsruhe ACC in terms of traffic numbers, but the first in terms of flight hours and distance.  MUAC has put in operation innovative technology and productivity enhancements: a new generation Flight Data Processing System, Integrated Flow Management Position, the Short Term Conflict Alert (STCA), Controller Pilot Data Link Communications (CPDLC) and stripless controller working positions.  Typically, air traffic control sectors at MUAC can handle 55 or more flights per hour. The average flight duration is approximately 21 minutes and typically 80% of the traffic is climbing from or descending to the major European airports of London, Paris, Frankfurt, Amsterdam and Berlin. Maastricht UAC has undoubtedly one of the most complex airspace structures in the world and the traffic flow (up to 5,670 aircraft a day) can be disrupted by the many surrounding military airspaces.

Membership criteria.

To be considered for membership of EUROCONTROL, a country must meet "all" of the following criteria:

Comprehensive Agreement States.

In addition to membership, EUROCONTROL also concludes the so-called Comprehensive Agreements, which enhances the organisation's cooperation with non-European countries that are closely tied to the continent's aviation network.

The European Organisation for the Safety of Air Navigation, commonly known as EUROCONTROL, is an international organisation working to achieve safe and seamless air traffic management across Europe. Founded in 1960, EUROCONTROL currently has 41 member states and is headquartered in Brussels, Belgium, with local sites in Brétigny-sur-Orge, France for its R&D activities, the Institute of Air Navigation Training (IANS) a training centre in Luxembourg, and the Maastricht Upper Area Control Centre (MUAC). The organisation employs approximately two thousand people and operates with an annual budget in excess of half a billion Euro.


Characteristics.

Bony fish are characterized by a relatively stable pattern of cranial bones, rooted, medial insertion of mandibular muscle in the lower jaw. The head and pectoral girdles are covered with large dermal bones. The eyeball is supported by a sclerotic ring of four small bones, but this characteristic has been lost or modified in many modern species. The labyrinth in the inner ear contains large otoliths. The braincase, or neurocranium, is frequently divided into anterior and posterior sections divided by a fissure.  Early bony fish had simple lungs (a pouch on either side of the esophagus) which helped them breathe in low-oxygen water. In many bony fish these have evolved into swim bladders, which help the body create a neutral balance between sinking and floating. (The lungs of amphibians, reptiles, birds, and mammals were inherited from their bony fish ancestors.) They do not have fin spines, but instead support the fin with lepidotrichia (bone fin rays). They also have an operculum, which helps them breathe without having to swim.  Bony fish have no placoid scales. Mucus glands coat the body. Most have smooth and overlapping ganoid, cycloid or ctenoid scales.

Classification.

Traditionally, Osteichthyes is considered a class, recognised on having a swim bladder, only three pairs of gill arches, hidden behind a bony operculum and a predominately bony skeleton. Under this classification systems, the Osteichthyes are paraphyletic with regard to land vertebrates as the common ancestor of all Osteichthyes includes tetrapods amongst its descendants. The largest subclass, the Actinopterygii (ray-finned fish) are monophyletic, but with the inclusion of the smaller sub-class Sarcopterygii, Osteichthyes is paraphyletic.  This has led to an alternative cladistic classification, splitting the Osteichthyes into two full classes. Osteichthyes is under this scheme monophyletic, as it includes the tetrapods, making it a synonym of the clade Euteleostomi. Most bony fish belong to the ray-finned fish (Actinopterygii).

Phylogeny.

A phylogeny of living Osteichthyes, including the tetrapods, is shown in the cladogram.  Whole-genome duplication took place in the ancestral Osteichthyes.

Biology.

All bony fish possess gills. For the majority this is their sole or main means of respiration. Lungfish and other osteichthyan species are capable of respiration through lungs or vascularized swim bladders. Other species can respire through their skin, intestines, and/or stomach.  Osteichthyes are primitively ectothermic (cold blooded), meaning that their body temperature is dependent on that of the water. But some of the larger marine osteichthyids, such as the opah, swordfish and tuna have independently evolved various levels of endothermy. Bony fish can be any type of heterotroph: numerous species of omnivore, carnivore, herbivore, filter-feeder or detritivore are documented.  Some bony fish are hermaphrodites, and a number of species exhibit parthenogenesis. Fertilization is usually external, but can be internal. Development is usually oviparous (egg-laying) but can be ovoviviparous, or viviparous. Although there is usually no parental care after birth, before birth parents may scatter, hide, guard or brood eggs, with sea horses being notable in that the males undergo a form of "pregnancy", brooding eggs deposited in a ventral pouch by a female.

Examples.

The ocean sunfish is the heaviest bony fish in the world, while the longest is the king of herrings, a type of oarfish. Specimens of ocean sunfish have been observed up to in length and weighing up to. Other very large bony fish include the Atlantic blue marlin, some specimens of which have been recorded as in excess of, the black marlin, some sturgeon species, and the giant and goliath grouper, which both can exceed in weight. In contrast, "Paedocypris progenetica" and the stout infantfish can measure less than.  The Beluga sturgeon is the largest species of freshwater bony fish extant today, and "Arapaima gigas" is among the largest of the freshwater fish. The largest bony fish ever was "Leedsichthys", which dwarfed the beluga sturgeon as well as the ocean sunfish, giant grouper and all the other giant bony fishes alive today.

Comparison with cartilaginous fishes Chondrichthyes.

Cartilaginous fishes can be further divided into sharks, rays and chimaeras. In the table below, the comparison is made between sharks and bony fishes. For the further differences with rays, see sharks versus rays.

Osteichthyes (), popularly referred to as the bony fish, is a diverse taxonomic group of fish that have skeletons primarily composed of bone tissue, as opposed to cartilage. The vast majority of fish are members of Osteichthyes, which is an extremely diverse and abundant group consisting of 45 orders, and over 435 families and 28,000 species. It is the largest class of vertebrates in existence today. The group Osteichthyes is divided into the ray-finned fish (Actinopterygii) and lobe-finned fish (Sarcopterygii). The oldest known fossils of bony fish are about 420 million years old, which are also transitional fossils, showing a tooth pattern that is in between the tooth rows of sharks and bony fishes.


Biography.

Early years.

Kamerlingh Onnes was born in Groningen, Netherlands. His father, Harm Kamerlingh Onnes, was a brickworks owner. His mother was Anna Gerdina Coers of Arnhem.  In 1870, Kamerlingh Onnes attended the University of Groningen. He studied under Robert Bunsen and Gustav Kirchhoff at the University of Heidelberg from 1871 to 1873. Again at Groningen, he obtained his masters in 1878 and a doctorate in 1879. His thesis was "Nieuwe bewijzen voor de aswenteling der aarde" ("tr". New proofs of the rotation of the earth). From 1878 to 1882 he was assistant to Johannes Bosscha, the director of the Delft Polytechnic, for whom he substituted as lecturer in 1881 and 1882.

Family.

He was married to Maria Adriana Wilhelmina Elisabeth Bijleveld (m. 1887) and had one child, named Albert. His brother Menso Kamerlingh Onnes (1860–1925) was a fairly well known painter (and father of another painter, Harm Kamerlingh Onnes), while his sister Jenny married another famous painter, Floris Verster (1861–1927).

University of Leiden.

From 1882 to 1923 Kamerlingh Onnes served as professor of experimental physics at the University of Leiden. In 1904 he founded a very large cryogenics laboratory and invited other researchers to the location, which made him highly regarded in the scientific community. The laboratory is known now as Kamerlingh Onnes Laboratory. Only one year after his appointment as professor he became member of the Royal Netherlands Academy of Arts and Sciences.

Liquefaction of helium.

On 10 July 1908, he was the first to liquefy helium, using several precooling stages and the Hampson–Linde cycle based on the Joule–Thomson effect. This way he lowered the temperature to the boiling point of helium (−269 °C, 4.2 K). By reducing the pressure of the liquid helium he achieved a temperature near 1.5 K. These were the coldest temperatures achieved on earth at the time. The equipment employed is at the Museum Boerhaave in Leiden.

Superconductivity.

In 1911 Kamerlingh Onnes measured the electrical conductivity of pure metals (mercury, and later tin and lead) at very low temperatures. Some scientists, such as William Thomson (Lord Kelvin), believed that electrons flowing through a conductor would come to a complete halt or, in other words, metal resistivity would become infinitely large at absolute zero. Others, including Kamerlingh Onnes, felt that a conductor's electrical resistance would steadily decrease and drop to nil. Augustus Matthiessen said that when the temperature decreases, the metal conductivity usually improves or in other words, the electrical resistivity usually decreases with a decrease of temperature.  On 8 April 1911, Kamerlingh Onnes found that at 4.2 K the resistance in a solid mercury wire immersed in liquid helium suddenly vanished. He immediately realized the significance of the discovery (as became clear when his notebook was deciphered a century later). He reported that ""Mercury has passed into a new state, which on account of its extraordinary electrical properties may be called the superconductive state"". He published more articles about the phenomenon, initially referring to it as ""supraconductivity"" and, only later adopting the term "superconductivity".  Kamerlingh Onnes received widespread recognition for his work, including the 1913 Nobel Prize in Physics for (in the words of the committee) ""his investigations on the properties of matter at low temperatures which led, "inter alia", to the production of liquid helium"".

Legacy.

Some of the instruments he devised for his experiments can be seen at the Boerhaave Museum in Leiden. The apparatus he used to first liquefy helium is on display in the lobby of the physics department at Leiden University, where the low-temperature lab is also named in his honor. His student and successor as director of the lab Willem Hendrik Keesom was the first person who was able to solidify helium, in 1926. The former Kamerlingh Onnes laboratory building is currently the Law Faculty at Leiden University and is known as "Kamerlingh Onnes Gebouw" (Kamerlingh Onnes Building), often shortened to "KOG". The current science faculty has a "Kamerlingh Onnes Laboratorium" named after him, as well as a plaque and several machines used by Kamerling Onnes in the main hall of the physics department.  The Kamerlingh Onnes Award was established in his honour, recognising further advances in low-temperature science.  The Onnes effect referring to the creeping of superfluid helium is named in his honor.  The crater Kamerlingh Onnes on the Moon is named after him.  Onnes is also credited with coining the word "enthalpy".  Onnes' discovery of superconductivity was named an IEEE Milestone in 2011.

Professor Heike Kamerlingh Onnes, (21 September 1853 – 21 February 1926) was a Dutch physicist and Nobel laureate. He exploited the Hampson–Linde cycle to investigate how materials behave when cooled to nearly absolute zero and later to liquefy helium for the first time, in 1908. He also discovered superconductivity in 1911.