History.

The Mall began as a field for playing pall-mall. In the 17th and 18th centuries it was a fashionable promenade, bordered by trees. It was envisioned as a ceremonial route in the early 20th century, matching the creation of similar ceremonial routes in other cities such as Berlin, Mexico City, Oslo, Paris, Saint Petersburg, Vienna and Washington, D.C. These routes were intended to be used for major national ceremonies. As part of the development – designed by Aston Webb – a new façade was constructed for Buckingham Palace, and the Victoria Memorial was erected.  The Victoria Memorial is immediately before the gates of the Palace, whilst Admiralty Arch at the far end leads into Trafalgar Square. The length of The Mall from where it joins Constitution Hill at the Victoria Memorial end to Admiralty Arch is exactly. St. James's Park is on the south side of The Mall, opposite Green Park and St James's Palace, on the north side. Running off The Mall at its eastern end is Horse Guards Parade, where the Trooping the Colour ceremony is held.  The surface of The Mall is coloured red to give the effect of a giant red carpet leading up to Buckingham Palace. This colour was obtained using synthetic iron oxide pigment from Deanshanger Oxide Works (Deanox), which was created using the Deanox Process devised by chemist Ernest Lovell. It was David Eccles' decision, as Minister of Works from 1951 to 1954, to make The Mall red.  On Victory in Europe Day (8 May 1945), the Palace was the centre of British celebrations, with the King, Queen and Princess Elizabeth (the future queen) and Princess Margaret appearing on the balcony, with the Palace's blacked-out windows behind them, to the cheers from a vast crowd on The Mall.  During state visits, the monarch and the visiting head of state are escorted in a state carriage up The Mall and the street is decorated with Union Flags and the flags of the visiting head of state's country. During the Golden Jubilee celebrations of Queen Elizabeth II in 2002, over one million people packed The Mall to watch the public displays and the appearance of the Royal Family on the palace balcony.  Scheduled buses are not allowed to use the Mall and go past Buckingham Palace except by permission of the monarch. This has only happened twice in history; in 1927 and in 1950.

Sporting events.

The annual London Marathon finishes on The Mall. It was also the start and finish line for the marathon course, the road race, and the race walks of the 2012 Olympic and Paralympic Games. The women's marathon took place on 5 August and the men's Olympic marathon on 12 August. The men's 20 km walk took place on 4 August, with the men's 50 km walk and women's 20 km walk took place on 11 August. The Paralympic marathons were held on 9 September. In recent years the Mall has also been repeatedly used as the finishing line for UK cycling events, including the 2012 Olympics Road Races, the Ride London Prudential Classic in 2013, and stage 3 of the 2014 Tour de France. The opening ceremony for the 2019 Cricket World Cup was held on The Mall.

The Mall () is a road in the City of Westminster, central London, between Buckingham Palace at its western end and Trafalgar Square via Admiralty Arch to the east. Near the east end at Trafalgar Square and Whitehall it is met by Horse Guards Road and Spring Gardens where the Metropolitan Board of Works and London County Council were once based. It is closed to traffic on Saturdays, Sundays, public holidays and on ceremonial occasions.

Mall je ulice v londýnském obvodu Westminster. Vede od Buckinghamského paláce (od památníku královny Viktorie) po Admirality Arch u Trafalgar Square. V neděli, o svátcích a při konání ceremoniálních akcí bývá uzavřena.


Geography.

The street is around long and runs east in the St James's area, from St James's Street across Waterloo Place, to the Haymarket and continues as Pall Mall East towards Trafalgar Square. The street numbers run consecutively from north-side east to west and then continue on the south-side west to east. It is part of the A4, a major road running west from Central London. London Bus Route 9 runs westwards along Pall Mall, connecting Trafalgar Square to Piccadilly and Hyde Park Corner.

History and topography.

Early history and pall-mall field.

Pall Mall was constructed in 1661, replacing an earlier highway slightly to the south that ran from the Haymarket (approximately where Warwick House Street is now) to the royal residence, St James's Palace. Historical research suggests a road had been in this location since Saxon times, although the earliest documentary references are from the 12th century in connection with a leper colony at St James's Hospital. When St. James's Park was laid out by order of Henry VIII in the 16th century, the park's boundary wall was built along the south side of the road. In 1620, the Privy Council ordered the High Sheriff of Middlesex to clear a number of temporary buildings next to the wall that were of poor quality.  Pall-mall, a ball game similar to croquet, was introduced to England in the early-17th century by James I. The game, already popular in France and Scotland, was enjoyed by James' sons Henry and Charles. In 1630, St James's Field, London's first pall-mall court, was laid out to the north of the Haymarket – St James road.  After the Restoration and King Charles II's return to London on 29 May 1660, another pall-mall court was constructed in St James's Park just south of the wall, on the site of The Mall. Samuel Pepys's diary entry for 2 April 1661 records that he '... went into St. James's Park, where I saw the Duke of York playing at Pelemele, the first time that I ever saw the sport'. This new court suffered from dust blown over the wall from coaches travelling along the highway. In July 1661 posts and rails were erected, stopping up the old road. The court for pall-mall was very long and narrow, and often known as an alley, so the old court, namely St James's Field, provided a suitable route for relocating the eastern approach to St James's Palace. A grant was made to Dan O'Neale, Groom of the Bedchamber, and John Denham, Surveyor of the King's Works allocating a area of land for this purpose. The grant was endorsed 'Our warrant for the building of the new street to St James's'.  A new road was built on the site of the old pall-mall court, and opened in September 1661. It was named Catherine Street, after Catherine of Braganza, wife of Charles II, but was better known as Pall Mall Street or the Old Pall Mall. The pall-mall field was a popular place for recreation and Pepys records several other visits. By July 1665 Pepys used 'Pell Mell' to refer to the street as well as the game.

17th- and 18th-century buildings.

In 1662, Pall Mall was one of several streets 'thought fitt immediately to be repaired, new paved or otherwise amended' under the Streets, London and Westminster Act 1662. The paving commissioners appointed to oversee the work included the Earl of St Albans. The terms of the act allowed commissioners to remove any building encroaching on the highway, with compensation for those at least 30 years old. The commissioners determined that the real tennis court and adjoining house at the northeast corner of Pall Mall and St James's Street should be demolished, and in 1664 notified Martha Barker, the owner of the Crown lease, to do so. Although Barker initially rejected £230 compensation, the court was demolished by 1679.  The street was developed extensively during 1662–1667. The Earl of St Albans had a lease from the Crown in 1662 on of land previously part of St James's Fields. He laid out the site for the development of St. James's Square, Jermyn Street, Charles Street, St Albans Street, King Street and other streets now known as St James's. The location was convenient for the royal palaces of Whitehall and St James and the houses on the east, north and west sides of the square were developed along with those on the north side of Pall Mall, each constructed separately as was usual for the time. Houses were not built along the square's south side at first, or the adjoining part of Pall Mall. The Earl petitioned the King in late 1663 that the class of occupants they hoped to attract to the new district would not take houses without the prospect of eventually acquiring them outright. Despite opposition from the Lord Treasurer, the Earl of Southampton, on 1 April 1665 the King granted the Earl of St Albans the freehold of the St James's Square site, along with all the ground on the north side of Pall Mall between St James's Street and the east side of St James's Square. The freehold of the north side of Pall Mall subsequently passed to other private owners. The Crown kept the freehold of the land south of the street except for No. 79, which was granted to Nell Gwyn's trustees in 1676 or 1677 by Charles II. The buildings constructed on the south side of Pall Mall in subsequent years were grander than those on the north owing to stricter design and building standards imposed by the crown commissioners. When the main road was relocated further north, some houses suddenly had their backs facing the main road, losing available land for gardening. In 1664, residents filed a petition to turn the old road into gardens, which was successful. The trustees of the Earl of St Albans received a sixty-year lease on most of this from April 1665 so that trustees could issue sub-leases to their tenants.  Several other portions of the old highway were leased for construction. At the east end, land was leased to Sir Philip Warwick who built Warwick House (now the location of Warwick House Street) and to Sir John Denham; this parcel of land became part of the grounds of Marlborough House. Portions leased at the west end included the land between St James's Palace and the tennis court at the corner of St James's Street, and a parcel of land leased to the Duchess of Cleveland that became the site of 8–12 Cleveland Row and Stornoway House. The 18th-century London bookseller Andrew Millar also lived in a townhouse designed by Robert Adam, at 34 Pall Mall.  104 Pall Mall was rebuilt in 1761–2 by John, second Earl of Egmont. Sir John Soane remodelled the house in 1793–4 for Lady Louisa Manners, Countess of Dysart who lived there until 1831. From 1831 to 1836 it was used for the storage and exhibition of the Royal picture collection. In 1836 it was acquired by the Reform Club.

Later history.

By the 18th century, Pall Mall was well known for its shops as well as its grand houses. The shops included that of the Vulliamy family who made clocks at No. 68 between 1765 and 1854. Robert Dodsley ran a bookshop at No. 52, where he suggested the idea of a dictionary to Samuel Johnson. Writers and artists began to move to Pall Mall during this century; both Richard Cosway and Thomas Gainsborough lived at Schomberg House at Nos. 80–82.  The street was one of the first in London to be lit by gas after Frederick Albert Winsor set up experimental lighting on 4 June 1807 to celebrate King George III's birthday. Permanent lighting was installed in 1820. The eastern end of Pall Mall was widened between 1814 and 1818; a row of houses on its north side was demolished to make way for the Royal Opera Arcade.  Pall Mall is known for the various gentlemen's clubs built there in the 19th and early 20th centuries. The Travellers Club was founded in 1819 and moved to No. 49 Pall Mall in 1822. Its current premises at No. 106 were built in 1823 by Charles Barry. The Athenaeum Club took its name from the Athenaeum in Rome, a university founded by the Emperor Hadrian. The club moved to No. 107 Pall Mall in 1830 from tenements in Somerset House. Its entrance hall was designed by Decimus Burton. The Reform Club at Nos. 104–105 was founded for the British Radicals in 1836. The Army and Navy Club at Nos. 36–39 was founded in 1837. The name was suggested by the Duke of Wellington in order to accommodate Royal Navy members. Other clubs on Pall Mall include the United Service Club (now occupied by the Institute of Directors), the Oxford and Cambridge Club and the Royal Automobile Club. Pall Mall was once the centre of London's fine art scene; in 1814 the Royal Academy, the National Gallery and Christie's auction house were all based on the street.  The freehold of much of the southern side of the Pall Mall is owned by the Crown Estate. In addition to St. James's Palace, Marlborough House, which was once a royal residence, is its neighbour to the east, opening off a courtyard just to the south of the street. It was built for Sarah, Duchess of Marlborough who laid the foundation stone in 1709, with building complete by 1711. The house reverted to Crown ownership in 1817; the future King George V was born here in 1865 and briefly lived in the house as Prince of Wales during the reign of his father, Edward VII. It became government-owned in 1959 and houses now the Commonwealth Secretariat and the Commonwealth Foundation. The Prince Regent's Carlton House was built at the eastern end of Pall Mall in 1732 for Frederick, Prince of Wales and later inhabited by his widow, Princess Augusta. A ball was held at the house on 19 June 1811 to celebrate the start of the Prince's regency, but ultimately he did not decide to stay in the house upon ascending the throne, and it was demolished. John Nash built Carlton House Terrace on its site between 1827 and 1832. Pall Mall was the location of the War Office from 1855 to 1906, with which it became synonymous (just as Whitehall refers to the administrative centre of the UK government). The War Office was accommodated in a complex of buildings based on the ducal mansion, Cumberland House. The office subsequently moved to Whitehall.  The street contained two other architecturally important residences. Schomberg House, at Nos. 80–82 Pall Mall was built in 1698 for Meinhardt Schomberg, 3rd Duke of Schomberg and divided into three parts in 1769. The eastern section of the house was demolished in 1850, but reconstructed in the mid-1950s for office use. Buckingham House was the London residence of the Dukes of Buckingham and Chandos. It was rebuilt in the 1790s by Sir John Soane and sold by the Buckingham estate in 1847. The house was demolished in 1908 to make way for the Royal Automobile Club.  No 77-78 Pall Mall was the home of the Marquess of Ailesbury from 1840. In 1892, it was inherited by the Marchioness' nephew, Viscount de Vesci who leased the building to the Office of Works. In 1902, it was granted to Queen Victoria's daughter, Princess Helena and her husband Prince Christian as a grace and favour residence and retained as a home by their daughters, Princess Helena Victoria and Princess Marie Louise until 1947. In 1951, the property was divided: No.77 was occupied by the Oxford and Cambridge University Club, and no.78 by the Eagle Star Insurance Company.  The Institute of Directors was founded in 1903 and received a royal charter in 1906. The former branch of the Midland Bank at Nos. 69–70 Pall Mall was designed by Edwin Lutyens and constructed between 1922 and 1927. The original plan to redevelop No. 70 proved impractical so the two premises were demolished to provide a site for the current premises. The cigarette manufacturer Rothmans has its head office at No. 65 Pall Mall, in a building designed by Norman Shaw, while P&O Ferries' main administrative office is at No. 79.

Cultural references.

Giacomo Casanova lived in Pall Mall during 1761 as "Chevalier de Seingalt", and documented the stay in his memoirs. When the novelist William Makepeace Thackeray visited Dublin in 1845, he compared Pall Mall to O'Connell Street (then known as Upper Sackville Street). In 1870, Henry Benjamin Wheatley wrote 'Round about Piccadilly and Pall Mall', documenting changes in and around the street over the century. A compilation of Oscar Wilde's works, "A Critic in Pall Mall : Being Extracts From Reviews And Miscellanies", was published in 1919 comprising essays he wrote for newspapers and journals from the 1870s to the 1890s.  Princess Elizabeth mentioned Pall Mall in her diary on celebrations on VE day: 'Out in crowd again,' she wrote. 'Trafalgar Square, Piccadilly, Pall Mall, walked simply miles. Saw parents on balcony at 12.30 am — ate, partied, bed 3am!'  Pall Mall is part of a group of three squares on the British "Monopoly" board game, alongside Whitehall and Northumberland Avenue. All three streets converge at Trafalgar Square. Rising house prices across London mean a small flat on Pall Mall, which is in the lowest-priced third of properties on the board, now sells for over £1 million.

References.

Notes Citations Sources

Pall Mall is a street in the St James's area of the City of Westminster, Central London. It connects St James's Street to Trafalgar Square and is a section of the regional A4 road. The street's name is derived from 'pall-mall', a ball game played there during the 17th century.

Pall Mall (vyslovováno přibližně "pel mel") je ulice v londýnském obvodu Westminster. Vede paralelně s Mall od "St. James's Street" až po Haymarket. Je částí dopravní tepny "A4".


Definitions.

In the conditional statement, "if "S", then "N"", the expression represented by "S" is called the antecedent, and the expression represented by "N" is called the consequent. This conditional statement may be written in several equivalent ways, such as ""N" if "S"", ""S" only if "N"", ""S" implies "N"", ""N" is implied by "S"",, and ""N" whenever "S"".  In the above situation, "N" is said to be a necessary condition for "S". In common language, this is equivalent to saying that if the conditional statement is a true statement, then the consequent "N" "must" be true—if "S" is to be true (see third column of "truth table" immediately below). In other words, the antecedent "S" cannot be true without "N" being true. For example, in order for someone to be called Socrates, it is necessary for that someone to be Named. Similarly, in order for human beings to live, it is necessary that they have air.  In the above situation, one can also say "S" is a sufficient condition for "N" (refer again to the third column of the truth table immediately below). If the conditional statement is true, then if "S" is true, "N" must be true; whereas if the conditional statement is true and N is true, then S may be true or be false. In common terms, "the truth of "S" guarantees the truth of "N"". For example, carrying on from the previous example, one can say that knowing that someone is called Socrates is sufficient to know that someone has a Name.  A necessary and sufficient condition requires that both of the implications formula_1 and formula_2 (the latter of which can also be written as formula_3) hold. The first implication suggests that "S" is a sufficient condition for "N", while the second implication suggests that "S" is a necessary condition for "N". This is expressed as ""S" is necessary and sufficient for "N" ", ""S" if and only if "N" ", or formula_4.

Necessity.

The assertion that "Q" is necessary for "P" is colloquially equivalent to ""P" cannot be true unless "Q" is true" or "if Q is false, then P is false". By contraposition, this is the same thing as "whenever "P" is true, so is "Q"".  The logical relation between "P" and "Q" is expressed as "if "P", then "Q"" and denoted ""P" ⇒ "Q"" ("P" implies "Q"). It may also be expressed as any of ""P" only if "Q"", ""Q", if "P"", ""Q" whenever "P"", and ""Q" when "P"". One often finds, in mathematical prose for instance, several necessary conditions that, taken together, constitute a sufficient condition (i.e., individually necessary and jointly sufficient), as shown in Example 5.

Sufficiency.

If "P" is sufficient for "Q", then knowing "P" to be true is adequate grounds to conclude that "Q" is true; however, knowing "P" to be false does not meet a minimal need to conclude that "Q" is false.  The logical relation is, as before, expressed as "if "P", then "Q"" or ""P" ⇒ "Q"". This can also be expressed as ""P" only if "Q"", ""P" implies "Q"" or several other variants. It may be the case that several sufficient conditions, when taken together, constitute a single necessary condition (i.e., individually sufficient and jointly necessary), as illustrated in example 5.

Relationship between necessity and sufficiency.

A condition can be either necessary or sufficient without being the other. For instance, "being a mammal" ("N") is necessary but not sufficient to "being human" ("S"), and that a number formula_11 "is rational" ("S") is sufficient but not necessary to formula_11 "being a real number" ("N") (since there are real numbers that are not rational).  A condition can be both necessary and sufficient. For example, at present, "today is the Fourth of July" is a necessary and sufficient condition for "today is Independence Day in the United States". Similarly, a necessary and sufficient condition for invertibility of a matrix "M" is that "M" has a nonzero determinant.  Mathematically speaking, necessity and sufficiency are dual to one another. For any statements "S" and "N", the assertion that ""N" is necessary for "S"" is equivalent to the assertion that ""S" is sufficient for "N"". Another facet of this duality is that, as illustrated above, conjunctions (using "and") of necessary conditions may achieve sufficiency, while disjunctions (using "or") of sufficient conditions may achieve necessity. For a third facet, identify every mathematical predicate "N" with the set "T"("N") of objects, events, or statements for which "N" holds true; then asserting the necessity of "N" for "S" is equivalent to claiming that "T"("N") is a superset of "T"("S"), while asserting the sufficiency of "S" for "N" is equivalent to claiming that "T"("S") is a subset of "T"("N").

Simultaneous necessity and sufficiency.

To say that "P" is necessary and sufficient for "Q" is to say two things:  One may summarize any, and thus all, of these cases by the statement ""P" if and only if "Q"", which is denoted by formula_16, whereas cases tell us that formula_16 is identical to formula_15.  For example, in graph theory a graph "G" is called bipartite if it is possible to assign to each of its vertices the color "black" or "white" in such a way that every edge of "G" has one endpoint of each color. And for any graph to be bipartite, it is a necessary and sufficient condition that it contain no odd-length cycles. Thus, discovering whether a graph has any odd cycles tells one whether it is bipartite and conversely. A philosopher might characterize this state of affairs thus: "Although the concepts of bipartiteness and absence of odd cycles differ in intension, they have identical extension.  In mathematics, theorems are often stated in the form ""P" is true if and only if "Q" is true". Their proofs normally first prove sufficiency, e.g. formula_14. Secondly, the opposite is proven, formula_20  This proves that the circles for Q and P match on the Venn diagrams above.  Because, as explained in previous section, necessity of one for the other is equivalent to sufficiency of the other for the first one, e.g. formula_13 is equivalent to formula_20, if "P" is necessary and sufficient for "Q", then "Q" is necessary and sufficient for "P". We can write formula_23 and say that the statements ""P" is true if and only if "Q", is true" and ""Q" is true if and only if "P" is true" are equivalent.  P1) If A then B

See also.

Argument forms involving necessary and sufficient conditions.

Valid forms of argument.

P2) A  C) Therefore B P1) If A then B  P2) Not-B  C) Therefore Not-A P1) If A then B  P2) If B then C  C) Therefore if A then C P1) A or B  P2) Not-A (or Not-B)  C) Therefore B (or A) P1) A or B  P2) If A then C  P3) If B then D  C) Therefore C or D

In logic and mathematics, necessity and sufficiency are terms used to describe a conditional or implicational relationship between two statements. For example, in the conditional statement: "If "P" then "Q"", Q is necessary for P, because the truth of P guarantees the truth of "Q" (equiv., it is impossible to have "P" without "Q"). Similarly, P is sufficient for Q, because P being true always implies that Q is true, but P not being true does not always imply that Q is not true.

V logice mohou mezi dvěma souvisejícími tvrzeními (větami, výroky) existovat vztahy, pro které se používají zažitá označení nutná, resp. postačující podmínka.


Mammals.

There is a variety of definitions for terms that describe hibernation in mammals, and different mammal clades hibernate differently. The following subsections discuss the terms "obligate" and "facultative" hibernation. The last two sections point out in particular primates, none of whom were thought to hibernate until recently, and bears, whose winter topor had been contested as not being "true hibernation" during the late 20th century, since it is dissimilar from hibernation seen in rodents.

Obligate hibernation.

Obligate hibernators are animals that spontaneously, and annually, enter hibernation regardless of ambient temperature and access to food. Obligate hibernators include many species of ground squirrels, other rodents, mouse lemurs, European hedgehogs and other insectivores, monotremes, and marsupials. These species undergo what has been traditionally called "hibernation": a physiological state wherein the body temperature drops to near ambient temperature, and heart and respiration rates slow drastically.  The typical winter season for obligate hibernators is characterized by periods of torpor interrupted by periodic, euthermic arousals, during which body temperatures and heart rates are restored to more typical levels. The cause and purpose of these arousals is still not clear; the question of why hibernators may return periodically to normal body temperatures has plagued researchers for decades, and while there is still no clear-cut explanation, there are multiple hypotheses on the topic. One favored hypothesis is that hibernators build a "sleep debt" during hibernation, and so must occasionally warm up to sleep. This has been supported by evidence in the Arctic ground squirrel. Other theories postulate that brief periods of high body temperature during hibernation allow the animal to restore its available energy sources or to initiate an immune response.  Hibernating Arctic ground squirrels may exhibit abdominal temperatures as low as, maintaining sub-zero abdominal temperatures for more than three weeks at a time, although the temperatures at the head and neck remain at or above.

Facultative hibernation.

Facultative hibernators enter hibernation only when either cold-stressed, food-deprived, or both, unlike obligate hibernators, who enter hibernation based on seasonal timing cues rather than as a response to stressors from the environment.  A good example of the differences between these two types of hibernation can be seen in prairie dogs:

Primates.

While hibernation has long been studied in rodents (namely ground squirrels) no primate or tropical mammal was known to hibernate until the discovery of hibernation in the fat-tailed dwarf lemur of Madagascar, which hibernates in tree holes for seven months of the year. Malagasy winter temperatures sometimes rise to over, so hibernation is not exclusively an adaptation to low ambient temperatures.  The hibernation of this lemur is strongly dependent on the thermal behaviour of its tree hole: If the hole is poorly insulated, the lemur's body temperature fluctuates widely, passively following the ambient temperature; if well insulated, the body temperature stays fairly constant and the animal undergoes regular spells of arousal. Dausmann found that hypometabolism in hibernating animals is not necessarily coupled with low body temperature.

Bears.

Historically there was a question of whether or not bears truly hibernate since they experience only a modest decline in body temperature (3–5 °C) compared with the much larger decreases (often 32 °C or more) seen in other hibernators. Many researchers thought that their deep sleep was not comparable with true, deep hibernation, but research in 2011 refuted this theory in captive black bears and again in 2016 in a study on brown bears.  Hibernating bears are able to recycle their proteins and urine, allowing them to stop urinating for months and to avoid muscle atrophy. They stay hydrated with the metabolic fat that is produced in sufficient quantities that satisfy the water needs of the bear. They also do not eat or drink while hibernating and live off of their fat storage.They also increase the availability of certain essential amino acids in the muscle, as well as regulate the transcription of a suite of genes that limit muscle wasting. In a study done by G. Edgar Folk, Jill M. Hunt and Mary A. Folk, they compared EKG of typical hibernators to 3 different bear species with respect to season, activity and dormancy, and found that the reduced relaxation (QT) interval of small hibernators was the same for the three bear species. They also found the QT interval changed for both typical hibernators and the bears from summer to winter. This 1977 study was one of the first evidences used to show that bears are hibernators.  In a 2016 study done by wildlife Veterinarian and Associate professor at Inland Norway University of Applied Sciences, Alina L. Evans researched 14 brown bears over three winters. Their movement, heart rate (HR), heart rate variability (HRV), body temperature (Tb), physical activity, ambient temperature (TA), and snow depth were measured to identify the drivers of the start and end of hibernation for bears. This study built the first chronology of both ecological and physiological events from before the start to the end of hibernation in the field. This research found that bears would enter their den when snow arrived, and the TA dropped to 0 °C but even up to several weeks before they entered their den, Activity, HR, and Tb started to drop slowly. Their HRV dropped dramatically once in their den which indirectly suggests metabolic suppression being related to the bears hibernation. Toward the end of hibernation and two months before arousal, the bear’s Tb rises, unrelated to HRV but rather driven by the TA. he HRV only increases around three weeks before arousal and the bears only leave their den once outside temperatures are at their lower critical temperature. These findings suggest that bears are thermoconforming and bear hibernation is driven by environmental cues, but arousal is driven by physiological cues.

Birds.

Ancient people believed that swallows hibernated, and ornithologist Gilbert White documented anecdotal evidence in his 1789 book "The Natural History of Selborne" that indicated the belief was still current in his time. It is now understood that the vast majority of bird species typically do not hibernate, instead utilizing torpor. One known exception is the common poorwill ("Phalaenoptilus nuttallii"), for which hibernation was first documented by Edmund Jaeger.

Dormancy in ectotherms.

Because they cannot actively down-regulate their body temperature or metabolic rate, ectothermic animals (including fish, reptiles, and amphibians) cannot hibernate. They can experience decreased metabolic rates associated with colder environments or low oxygen availability (hypoxia) and exhibit dormancy (known as brumation). It was once thought that basking sharks settled to the floor of the North Sea and became dormant, but research by David Sims in 2003 dispelled this hypothesis, showing that the sharks traveled long distances throughout the seasons, tracking the areas with the highest quantity of plankton. Epaulette sharks have been documented to be able to survive for long periods without oxygen and at temperatures of up to as a means to survive in their shoreline habitat, where water and oxygen levels vary with the tide. Other animals able to survive long periods with no or very little oxygen include goldfish, red-eared sliders, wood frogs, and bar-headed geese. The ability to survive hypoxic or anoxic conditions is not closely related to endotherm hibernation.

Hibernation induction trigger.

Hibernation induction trigger (HIT) is somewhat of a misnomer. Although research in the 1990s hinted at the ability to induce torpor in animals by injection of blood taken from a hibernating animal, further research has been unable to reproduce this phenomenon. Despite the inability to induce torpor, there are substances in the blood of hibernators that can lend protection to organs for possible transplant. Researchers were able to prolong the life of an isolated pig's heart with an HIT. This may have potentially important implications for organ transplant, as it could allow organs to survive for up to 18 hours outside the human body. This would be a great improvement from the current 6 hours.  The supposed HIT is a mixture derived from blood serum, including at least one opioid-like substance. DADLE is an opioid that in some experiments has been shown to have similar functional properties.

In humans.

Researchers have studied how to induce hibernation in humans. The ability to hibernate would be useful for a number of reasons, such as saving the lives of seriously ill or injured people by temporarily putting them in a state of hibernation until treatment can be given. For space travel, human hibernation is also under consideration for e.g. missions to Mars.

Hibernation is a state of inactivity and metabolic depression in endotherms. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most commonly occurs during winter months.

Hibernace, některé zdroje uvádějí též hybernace, česky zimní spánek, je specifická reakce živočichů na zimní období, kteří v klidovém stavu a při útlumu fyziologických procesů (projevující se především snížení tělesné teploty) přečkávají ve vhodném úkrytu, zvaném hibernakulum, nepříznivé zimní období. Je známý např. u netopýrů, ježků, křečků, plchů nebo syslů. V lékařství se termín používá i pro označení stavu nízké teploty (podchlazení) pacienta (může jít jak o symptom, tak o cílený léčebný prostředek).


Name.

Historically, it was common to refer to a river simply as "water." There are similar words for "water" or "river" in a number of Asiatic languages: "e.g." 물 "mul" ("water") in Korean, "muren" or "mörön" ("river") in Mongolian, and 水 "midu" > "mizu" ("water") in Japanese. The name "Amur" may have evolved from a root word for water, coupled with a size modifier for "Big Water".  The Chinese name for the river, "Heilong Jiang", means Black Dragon River in Chinese, and its Mongolian name, "Khar mörön" (Cyrillic: Хар мөрөн), means Black River.  The Amur is called "Hara-Muren" in Mongolian, "Silkar" in Tungusian, "Sahaliyan Ula" in Manchurian.  Its ancient names were Yushui, Wanshui and Heishui. The Russian name Amur is originated from the Mongolian name Amar, meaning quiet or peaceful.

Course.

The river rises in the hills in the western part of Northeast China at the confluence of its two major affluents, the Shilka and the Argun (or Ergune), at an elevation of. It flows east forming the border between China and Russia, and slowly makes a great arc to the southeast for about, receiving many tributaries and passing many small towns. At Huma, it is joined by a major tributary, the Huma He. Afterwards it continues to flow south until, between the cities of Blagoveshchensk in Russia and Heihe in China, it widens significantly as it is joined by one of its most important tributaries the Zeya.  The Amur arcs to the east and turns southeast again at the confluence with the Bureya, then does not receive another significant tributary for nearly before its confluence with its largest tributary, the Songhua, at Tongjiang. At the confluence with the Songhua the river turns northeast, now flowing towards Khabarovsk, where it joins the Ussuri and ceases to define the Russia–China border. Now the river spreads out dramatically into a braided character, flowing north-northeast through a wide valley in eastern Russia, passing Amursk and Komsomolsk-on-Amur. The valley narrows after about and the river again flows north onto plains at the confluence with the Amgun. Shortly after, the Amur turns sharply east and into an estuary at Nikolayevsk-on-Amur, about downstream of which it flows into the Strait of Tartary.

Tributaries.

The largest tributaries of the Amur are, from source to mouth:

History and context.

Many historical references distinguish two geopolitical entities in the area of the Amur: Outer Manchuria (Russian Manchuria) and Inner Manchuria (northeast China). The Chinese province of Heilongjiang on the south bank of the river takes its name from the river, as does the Russian Amur Oblast on the north bank. The native Manchu people and their Qing Empire of China, who regarded this river as sacred, use the name "sahaliyan ula" (Black River).  The Amur is an important symbol of, and geopolitical factor in, Chinese–Russian relations. The Amur became especially prominent in the period of the Sino–Soviet political split of 1956-1966.  For many centuries inhabitants of the Amur Valley comprised the Tungusic (Evenki, Solon, Ducher, Jurchen, Nanai, Ulch), Mongol (Daur) people, some Ainu and, near its mouth, the Nivkhs. For many of these groups, fishing in the Amur and its tributaries was the main source of their livelihood. Until the 17th century these peoples were not known to Europeans, and little known to the Han Chinese, who sometimes collectively described them as the Wild Jurchens. The Chinese-language term "Yúpí Dázi" 魚皮韃子 ("Fish-skin Tatars") came to apply to the Nanais and related groups as well, owing to their traditional clothes made of fish skins. The Mongols, ruling the region as the Yuan dynasty, established a tenuous military presence on the lower Amur in the 13th and14th centuries; ruins of a Yuan-era temple have been excavated near the village of Tyr.  During the reigns of the Yongle and Xuande Emperors (early-15th century), the Ming dynasty reached the Amur in their drive to establish control over the lands adjacent to the Ming Empire to the northeast, which would later become known as Manchuria. Expeditions headed by the eunuch Yishiha reached Tyr several times between 1411 and the early 1430s, re-building (twice) the Yongning Temple and obtaining at least the nominal allegiance of the lower Amur's tribes to the Ming government. Some sources report also a Chinese presence during the same period on the middle Amur – a fort existed at Aigun for about 20 years during the Yongle era on the left (northwestern) shore of the Amur downstream from the mouth of the Zeya River. This Ming Dynasty Aigun was located on the opposite bank to the later Aigun that was later relocated during the Qing Dynasty. In any event, the Ming presence on the Amur was as short-lived as it was tenuous; soon after the end of the Yongle era, the Ming dynasty's frontiers retreated to southern Manchuria. Chinese cultural and religious influence such as Chinese New Year, the "Chinese god", Chinese motifs like the dragon, spirals, scrolls, and material goods like agriculture, husbandry, heating, iron cooking-pots, silk, and cotton spread among Amur natives such as the Udeghes, Ulchis, and Nanais.  Russian Cossack expeditions led by Vassili Poyarkov and Yerofey Khabarov explored the Amur and its tributaries in 1643–44 and 1649–51, respectively. The Cossacks established the fort of Albazin on the upper Amur, at the site of the former capital of the Solons. At the time, the Manchus were busy with conquering China; but a few decades later, during the Kangxi era of 1661-1722, they turned their attention to their north-Manchurian backyard. Aigun was re-established near the supposed Ming site in about 1683–84, and a military expeditions went upstream to dislodge the Russians, whose Albazin establishment deprived the Manchu rulers of the tribute of sable pelts that the Solons and Daurs of the area would supply otherwise. Albazin fell during a short military campaign in 1685. The Treaty of Nerchinsk, concluded in 1689, marked the end of the hostilities: it left the entire Amur valley, from the convergence of the Shilka and the Ergune downstream, in Chinese hands.  Fedor Soimonov was sent to map the then little explored area of the Amur in 1757. He mapped the Shilka, which was partly in Chinese territory, but was turned back when he reached its confluence with the Argun. The Russian proselytization of Orthodox Christianity to the indigenous peoples along the Amur was viewed as a threat by the Qing.  The Amur region remained a relative backwater of the Qing Empire for the next century and a half, with Aigun being practically the only major town on the river. Russians re-appeared on the river in the mid-19th century, forcing the Manchus to yield all lands north of the river to the Russian Empire by the Treaty of Aigun (1858). Lands east of the Ussuri and the lower Amur were acquired by Russia as well, by the Convention of Peking (1860).  The acquisition of the lands on the Amur and the Ussuri was followed by the migration of Russian settlers to the region and the construction of such cities as Blagoveshchensk and, later, Khabarovsk.  Numerous river steamers, built in England, plied the Amur by the late 19th century. Tsar Nicolas II, then Tsarovitch, visited Vladivostok and then cruised up the river. Mining dredges were imported from America to work the placer gold of the river. Barge and river traffic was greatly hindered by the Civil War of 1918–22. The Soviet Reds had the Amur Flotilla which patrolled the river on sequestered riverboats. In the 1930s and during the War the Japanese had their own flotilla on the river. In 1945 the Soviets again put their own flotilla on the river. The ex-German Yangtse gunboats Vaterland and Otter, on Chinese Nationalist Navy service, patrolled the Amur in the 1920s.

Wildlife.

It is believed there are at least 123 species of fish from 23 families inhabiting the Amul. The majority are of the "Gobioninae" subfamily of "Cypriniformes", followed in number by Salmonidae. Several of the species are endemic. "Pseudaspius" and "Mesocottus" are monotypic genera found only in the Amur and some nearby coastal rivers.  Four species of the Acipenseridae family can be found: the kaluga, Amur sturgeon, Sakhalin sturgeon and sterlet. The Kaluga and Amur sturgeon are endemic. The sterlet was introduced from the Ob in the 1950s.

Direction.

Flowing across northeast Asia for over (including its two tributaries), from the mountains of northeastern China to the Sea of Okhotsk (near Nikolayevsk-na-Amure), it drains a remarkable watershed that includes diverse landscapes of desert, steppe, tundra, and taiga, eventually emptying into the Pacific Ocean through the Strait of Tartary, where the mouth of the river faces the northern end of the island of Sakhalin.  The Amur has always been closely associated with the island of Sakhalin at its mouth, and most names for the island, even in the languages of the indigenous peoples of the region, are derived from the name of the river: "Sakhalin" derives from a Tungusic dialectal form cognate with Manchu "sahaliyan" ("black", as in "sahaliyan ula", "Black River"), while Ainu and Japanese "Karaputo" or "Karafuto" is derived from the Ainu name of the Amur or its mouth. Anton Chekhov vividly described the Amur in writings about his journey to Sakhalin Island in 1890.  The average annual discharge varies from (1980) to (1957), leading to an average or per year. The maximum runoff measured occurred in Oct 1951 with whereas the minimum discharge was recorded in March 1946 with a mere.

Bridges and tunnels.

The first permanent bridge across the Amur, the Khabarovsk Bridge with an overall length of, was completed in 1916, allowing the trains on the Trans-Siberian Railway to cross the river year-round without using ferries or rail tracks on top of the river ice. In 1941 a railway tunnel was added as well.  Later, a combined road and rail bridge over the Amur at Komsomolsk-on-Amur (1975; 1400 m) and the road and rail Khabarovsk Bridge (1999; 3890 m) were constructed. The Tongjiang-Nizhneleninskoye railway bridge was proposed in 2007 by Valery Solomonovich Gurevich, the vice-chairman of the Jewish Autonomous Oblast in Russia. The railway bridge over the Amur will connect Tongjiang with Nizhneleninskoye, a village in the Jewish Autonomous Oblast. The Chinese portion of the bridge was finished in July 2016. In December 2016, work began on the Russian portion of the bridge. The bridge is expected to open in 2020.

The Amur (, ), or Heilong Jiang (, "Black Dragon River", ), is the world's tenth longest river, forming the border between the Russian Far East and Northeastern China (Inner Manchuria). The Amur proper is long, and has a drainage basin of. Including its source river Argun, it is long. The largest fish species in the Amur is the kaluga, attaining a length as great as. The river basin is home to a variety of large predatory fish such as northern snakehead, Amur pike, taimen, Amur catfish, predatory carp and yellowcheek, as well as the northernmost populations of the Amur softshell turtle and Indian lotus.

Amur (,, mandžusky "Sahaliyan Ula", ) je řeka ve Východní Asii, která tvoří přirozenou hranici mezi Ruskem (Zabajkalský kraj, Amurská oblast, Židovská autonomní oblast) a ČLR (Vnitřní Mongolsko a Chej-lung-ťiang) a na dolním toku protéká jen "Ruskem" Chabarovský kraj. V mongolštině a mandžuštině její jméno znamená "Černá řeka" a v čínštině "řeka Černého draka". Povodí "Amuru" se rozkládá na území tří států "Ruska", "ČLR" a Mongolska. Převládající část náleží "Rusku". Velikostí povodí zaujímá "Amur" 4. místo v "Rusku" (po Jeniseji, Obu a Leně) a 10. místo na světě. Povodí se zvětšilo poté, co se na Arguň napojila řeka Cherlen odtékající z dříve bezodtokého jezera Chulun núr (na mapce není vyznačeno). Je 2 824 km dlouhý. Od pramenů zdrojnice řeky Arguň, jíž je čínská řeka Chaj-lar-che, je to 4400 km. Hydrografická síť "Amuru" zahrnuje 10 610 řek (z nich je 1 684 kratších než 10 km) a 61 426 jezer o rozloze 10 599 km2 (včetně bezodtokých Torejských jezer). Povodí má rozlohu 1 855 000 km2.


History.

Baudot code (ITA1).

Baudot invented his original code in 1870 and patented it in 1874. It was a five-bit code, with equal on and off intervals, which allowed for transmission of the Roman alphabet, and included punctuation and control signals. It was based on an earlier code developed by Carl Friedrich Gauss and Wilhelm Weber in 1834. It was a Gray code (when vowels and consonants are sorted in their alphabetical order), nonetheless, the code by itself was not patented (only the machine) because French patent law does not allow concepts to be patented.  Baudot's original code was adapted to be sent from a manual keyboard, and no teleprinter equipment was ever constructed that used it in its original form. The code was entered on a keyboard which had just five piano-type keys and was operated using two fingers of the left hand and three fingers of the right hand. Once the keys had been pressed, they were locked down until mechanical contacts in a distributor unit passed over the sector connected to that particular keyboard, when the keyboard was unlocked ready for the next character to be entered, with an audible click (known as the "cadence signal") to warn the operator. Operators had to maintain a steady rhythm, and the usual speed of operation was 30 words per minute.  The table "shows the allocation of the Baudot code which was employed in the British Post Office for continental and inland services. A number of characters in the continental code are replaced by fractionals in the inland code. Code elements 1, 2 and 3 are transmitted by keys 1, 2 and 3, and these are operated by the first three fingers of the right hand. Code elements 4 and 5 are transmitted by keys 4 and 5, and these are operated by the first two fingers of the left hand."  Baudot's code became known as the International Telegraph Alphabet No. 1 (ITA1). It is no longer used.

Murray code.

In 1901, Baudot's code was modified by Donald Murray (1865–1945), prompted by his development of a typewriter-like keyboard. The Murray system employed an intermediate step; a keyboard perforator, which allowed an operator to punch a paper tape, and a tape transmitter for sending the message from the punched tape. At the receiving end of the line, a printing mechanism would print on a paper tape, and/or a reperforator could be used to make a perforated copy of the message. As there was no longer a connection between the operator's hand movement and the bits transmitted, there was no concern about arranging the code to minimize operator fatigue, and instead Murray designed the code to minimize wear on the machinery, assigning the code combinations with the fewest punched holes to the most frequently used characters.  For example, the one-hole letters are E and T. The ten two-hole letters are AOINSHRDLZ, very similar to the "Etaoin shrdlu" order used in Linotype machines. Ten more letters, BCGFJMPUWY, have three holes each, and the four-hole letters are VXKQ.  The Murray code also introduced what became known as "format effectors" or "control characters" the CR (Carriage Return) and LF (Line Feed) codes. A few of Baudot's codes moved to the positions where they have stayed ever since: the NULL or BLANK and the DEL code. NULL/BLANK was used as an idle code for when no messages were being sent, but the same code was used to encode the space separation between words. Sequences of DEL codes (fully punched columns) were used at start or end of messages or between them, allowing easy separation of distinct messages. (BELL codes could be inserted in those sequences to signal to the remote operator that a new message was coming or that transmission of a message was terminated).  Early British Creed machines also used the Murray system.

Western Union.

Murray's code was adopted by Western Union which used it until the 1950s, with a few changes that consisted of omitting some characters and adding more control codes. An explicit SPC (space) character was introduced, in place of the BLANK/NULL, and a new BEL code rang a bell or otherwise produced an audible signal at the receiver. Additionally, the WRU or "Who aRe yoU?" code was introduced, which caused a receiving machine to send an identification stream back to the sender.

ITA2.

In 1924, the CCITT introduced the International Telegraph Alphabet No. 2 (ITA2) code as an international standard, which was based on the Western Union code with some minor changes. The US standardized on a version of ITA2 called the American Teletypewriter code (US TTY) which was the basis for 5-bit teletypewriter codes until the debut of 7-bit ASCII in 1963.  Some code points (marked blue in the table) were reserved for national-specific usage.  The code position assigned to Null was in fact used only for the idle state of teleprinters. During long periods of idle time, the impulse rate was not synchronized between both devices (which could even be powered off or not permanently interconnected on commuted phone lines). To start a message it was first necessary to calibrate the impulse rate, a sequence of regularly timed "mark" pulses (1), by a group of five pulses, which could also be detected by simple passive electronic devices to turn on the teleprinter. This sequence of pulses generated a series of Erasure/Delete characters while also initializing the state of the receiver to the Letters shift mode. However, the first pulse could be lost, so this power on procedure could then be terminated by a single Null immediately followed by an Erasure/Delete character. To preserve the synchronization between devices, the Null code could not be used arbitrarily in the middle of messages (this was an improvement to the initial Baudot system where spaces were not explicitly differentiated, so it was difficult to maintain the pulse counters for repeating spaces on teleprinters). But it was then possible to resynchronize devices at any time by sending a Null in the middle of a message (immediately followed by an Erasure/Delete/LS control if followed by a letter, or by a FS control if followed by a figure). Sending Null controls also did not cause the paper band to advance to the next row (as nothing was punched), so this saved precious lengths of punchable paper band. On the other hand, the Erasure/Delete/LS control code was always punched and always shifted to the (initial) letters mode. According to some sources, the Null code point was reserved for country-internal usage only.  The Shift to Letters code (LS) is also usable as a way to cancel/delete text from a punched tape after it has been read, allowing the safe destruction of a message before recycling the punched band. Functionally, it can also play the same filler role as the Delete code in ASCII (or other 7-bit and 8-bit encodings, including EBCDIC for punched cards). After codes in a fragment of text have been replaced by an arbitrary number of LS codes, what follows is still preserved and decodable. It can also be used as an initiator to make sure that the decoding of the first code will not give a digit or another symbol from the figures page (because the Null code can be arbitrarily inserted near the end or beginning of a punch band, and has to be ignored, whereas the Space code is significant in text).  The cells marked as reserved for extensions (which use the LS code again a second time—just after the first LS code—to shift from the figures page to the letters shift page) has been defined to shift into a new mode. In this new mode, the letters page contains only lowercase letters, but retains access to a third code page for uppercase letters, either by encoding for a single letter (by sending LS before that letter), or locking (with FS+LS) for an unlimited number of capital letters or digits before then unlocking (with a single LS) to return to lowercase mode. The cell marked as "Reserved" is also usable (using the FS code from the figures shift page) to switch the page of figures (which normally contains digits and "national" lowercase letters or symbols) to a fourth page (where national letters are uppercased and other symbols may be encoded).  ITA2 is still used in telecommunications devices for the deaf (TDD), telex, and some amateur radio applications, such as radioteletype ("RTTY"). ITA2 is also used in Enhanced Broadcast Solution (an early 21st century financial protocol specified by Deutsche Börse) to reduce the character encoding footprint.

Nomenclature.

Nearly all 20th-century teleprinter equipment used Western Union's code, ITA2, or variants thereof. Radio amateurs casually call ITA2 and variants "Baudot" incorrectly, and even the American Radio Relay League's Amateur Radio Handbook does so, though in more recent editions the tables of codes correctly identifies it as ITA2.

Character set.

The values shown in each cell are the Unicode codepoints, given for comparison.

Weather code.

Meteorologists used a variant of ITA2 with the figures-case symbols, except for the ten digits, BEL and a few other characters, replaced by weather symbols:

Details.

NOTE: This table presumes the space called "1" by Baudot and Murray is rightmost, and least significant. The way the transmitted bits were packed into larger codes varied by manufacturer. The most common solution allocates the bits from the least significant bit towards the most significant bit (leaving the three most significant bits of a byte unused).  In ITA2, characters are expressed using five bits. ITA2 uses two code sub-sets, the "letter shift" (LTRS), and the "figure shift" (FIGS). The FIGS character (11011) signals that the following characters are to be interpreted as being in the FIGS set, until this is reset by the LTRS (11111) character. In use, the LTRS or FIGS shift key is pressed and released, transmitting the corresponding shift character to the other machine. The desired letters or figures characters are then typed. Unlike a typewriter or modern computer keyboard, the shift key isn't kept depressed whilst the corresponding characters are typed. "ENQuiry" will trigger the other machine's answerback. It means "Who are you?"  CR is carriage return, LF is line feed, BEL is the bell character which rang a small bell (often used to alert operators to an incoming message), SP is space, and NUL is the null character (blank tape).  Note: the binary conversions of the codepoints are often shown in reverse order, depending on (presumably) from which side one views the paper tape. Note further that the "control" characters were chosen so that they were either symmetric or in useful pairs so that inserting a tape "upside down" did not result in problems for the equipment and the resulting printout could be deciphered. Thus FIGS (11011), LTRS (11111) and space (00100) are invariant, while CR (00010) and LF (01000), generally used as a pair, are treated the same regardless of order by page printers. LTRS could also be used to overpunch characters to be deleted on a paper tape (much like DEL in 7-bit ASCII).  The sequence "RYRYRY..." is often used in test messages, and at the start of every transmission. Since R is 01010 and Y is 10101, the sequence exercises much of a teleprinter's mechanical components at maximum stress. Also, at one time, fine-tuning of the receiver was done using two coloured lights (one for each tone). 'RYRYRY...' produced 0101010101..., which made the lights glow with equal brightness when the tuning was correct. This tuning sequence is only useful when ITA2 is used with two-tone FSK modulation, such as is commonly seen in radioteletype (RTTY) usage.  US implementations of Baudot code may differ in the addition of a few characters, such as #, & on the FIGS layer.  The Russian version of Baudot code (MTK-2) used three shift modes; the Cyrillic letter mode was activated by the character (00000). Because of the larger number of characters in the Cyrillic alphabet, the characters!, &, £ were omitted and replaced by Cyrillics, and BEL has the same code as Cyrillic letter Ю. The Cyrillic letters Ъ and Ё are omitted, and Ч is merged with the numeral 4.

The Baudot code is an early character encoding for telegraphy invented by Émile Baudot in the 1870s, It was the predecessor to the International Telegraph Alphabet No. 2 (ITA2), the most common teleprinter code in use until the advent of ASCII. Each character in the alphabet is represented by a series of five bits, sent over a communication channel such as a telegraph wire or a radio signal. The symbol rate measurement is known as baud, and is derived from the same name.

Mezinárodní telegrafní abeceda číslo 2 (MTA-2, ) je pětibitová abeceda, používaná zejména v dálnopisném provozu. Byla přijata jako standard doporučením CCITT S.1. Vzhledem k tomu, že pětibitový kód není schopen pokrýt veškerou množinu znaků, používají se řídicí znaky přepínání registru. Abeceda má nulovou redundanci a využívá plně celý prostor kódu.


Operation.

The coating was a barrier that prevented direct contact of magnetic mines with metal surfaces of vehicles. The magnetostatic field decreases very rapidly, with the cube of distance; the non-magnetic coating holds the magnet of the mine too far from the steel of the vehicle for it to adhere. The coating was normally ridged to increase the distance between the magnet and the armor even further, as the high points on the pattern increase the effective thickness of the coating without adding more weight.  The mixture had the consistency of a thick paste or putty. It was applied to the vehicle, usually at the factory, patterned, and then hardened with blow torches. There were many variations seen in application designs, from the regular ridge-shaped pattern, to a less common waffle-shaped pattern. The differences mostly related to the factory producing each type of AFV. For example, the waffle pattern was seen almost exclusively on Sturmgeschütz III assault guns. In general, vehicles already in service were not coated with Zimmerit.

Deployment.

The German army introduced the "Hafthohlladung" anti-tank weapon in 1942. This consisted of a shaped charge warhead connected to a ring of metal holding three powerful horseshoe magnets. Issued to infantry, the user would run up to the tank and place the device on any surface to which the magnets would stick. The user would then pull the safety pin and run for safety. The magnets not only held the mine to the vehicle but also provided the correct spacing between warhead and armor, allowing the penetrator jet to form properly. Concerned that the simple design could be easily copied in the USSR or the thought that many of these weapons could fall into the hands of Allied soldiers, the German army began looking for ways to defeat such a weapon when used against their own vehicles.  "Zimmerit" was applied to some tanks and casemate-style closed-top self-propelled guns and tank destroyers produced from December 1943 to 9 September 1944. It was only rarely applied to open-topped AFVs. The rough appearance of the coating gave a distinct appearance; for one type, e.g. a shingle-like look.  "Zimmerit" was discontinued from factory application on 9 September 1944 and from field application on 7 October 1944. This was due to concerns that projectile impacts could ignite it. These proved false, but the order was never rescinded. Applying and drying the paste added days to the production of each vehicle, which was unacceptable as there was a shortage of tanks.  Following the war, the British carried out trials of a similar material on Churchill and Cromwell tanks and some trials were conducted in Canada with a similar material applied to self-propelled guns but it was not implemented. No similar material was used on post-war tanks as the widespread use of man-portable HEAT rockets such as the Bazooka made magnetic mines obsolete.

Ingredients.

The paste was composed of the following:  In the raw paste, polyvinyl acetate was used in the form of "Mowilith 20", a 50% benzene solution. During the drying process, the benzene evaporated and the mixture hardened.

Zimmerit was a paste-like coating used on mid- and late-war German armored fighting vehicles during World War II. It was used to produce a hard layer covering the metal armor of the vehicle, providing enough separation that magnetically attached anti-tank mines would fail to stick to the vehicle, although Germany was the only country to use magnetic anti-tank mines in numbers. "Zimmerit" was often left off late-war vehicles due to the unfounded concern that it could catch fire when hit. It was developed by the German company Chemische Werke Zimmer & Co (Berlin).

Zimmerit byl materiál pastovité konzistence používaný za druhé světové války k ochraně tanků proti magnetickým minám. Vyráběla jej firma "Chemische Werke Zimmer AG" v Německu. Zimmerit byl podobný jemnému betonu, nanášel se zubovou stěrkou, která vytvářela charakteristický povrch. Po chemické stránce byl Zimmerit směsí síranu barnatého (40 %), polyvinylacetátu (25 %), okrového pigmentu (15 %), sulfidu zinečnatého (10 %) a deseti procent dřevěných pilin. Hmota tedy neobsahovala žádnou antimagnetickou látku, princip její funkce byl ve vytvoření odstupu mezi kovem tanku a magnetickou minou, která z vozidla spadla díky vlastní váze nebo vibracím. Z obavy že odražené střely způsobují vzplanutí pasty Zimmerit byla v září 1944 pozastavena tovární nanášení (v polních podmínkách se Zimmerit nanášel až do října 1944). Obavy se nakonec nepotvrdily, ale již nedošlo k obnově továrního nanášení, protože to prodlužovalo výrobu pancéřových vozidel a hrozba magnetických min byla na frontě pro německé tanky minimální.


Nomenclature.

"α Orionis" (Latinised to "Alpha Orionis") is the star's designation given by Johann Bayer in 1603.  The traditional name "Betelgeuse" is derived from either the Arabic ', meaning "the armpit of Orion", or'"the hand of Orion". In English there are four common pronunciations of this name, depending on whether the first "e" is

Observational history.

Betelgeuse and its red coloration have been noted since antiquity; the classical astronomer Ptolemy described its color as ὑπόκιρρος ("hypókirrhos"), a term that was later described by a translator of Ulugh Beg's "Zij-i Sultani" as "rubedo", Latin for "ruddiness". In the nineteenth century, before modern systems of stellar classification, Angelo Secchi included Betelgeuse as one of the prototypes for his Class III (orange to red) stars. By contrast, three centuries before Ptolemy, Chinese astronomers observed Betelgeuse as having a yellow coloration; if accurate, such an observation could suggest the star was in a yellow supergiant phase around the beginning of the Christian era, a possibility given current research into the complex circumstellar environment of these stars.

Nascent discoveries.

The variation in Betelgeuse's brightness was described in 1836 by Sir John Herschel, when he published his observations in "Outlines of Astronomy". From 1836 to 1840, he noticed significant changes in magnitude when Betelgeuse outshone Rigel in October 1837 and again in November 1839. A 10-year quiescent period followed; then in 1849, Herschel noted another short cycle of variability, which peaked in 1852. Later observers recorded unusually high maxima with an interval of years, but only small variations from 1957 to 1967. The records of the American Association of Variable Star Observers (AAVSO) show a maximum brightness of 0.2 in 1933 and 1942, and a minimum of 1.2, observed in 1927 and 1941. This variability in brightness may explain why Johann Bayer, with the publication of his "Uranometria" in 1603, designated the star "alpha"

Imaging breakthroughs.

In the 1970s, astronomers saw some major advances in astronomical imaging technology, beginning with Antoine Labeyrie's invention of speckle interferometry, a process that significantly reduced the blurring effect caused by astronomical seeing. It increased the optical resolution of ground-based telescopes, allowing for more precise measurements of Betelgeuse's photosphere. With improvements in infrared telescopy atop Mount Wilson, Mount Locke, and Mauna Kea in Hawaii, astrophysicists began peering into the complex circumstellar shells surrounding the supergiant, causing them to suspect the presence of huge gas bubbles resulting from convection. But it was not until the late 1980s and early 1990s, when Betelgeuse became a regular target for aperture masking interferometry, that breakthroughs occurred in visible-light and infrared imaging. Pioneered by John E. Baldwin and colleagues of the Cavendish Astrophysics Group, the new technique employed a small mask with several holes in the telescope pupil

2000s studies.

In a study published in December 2000, the star's diameter was measured with the Infrared Spatial Interferometer (ISI) at mid-infrared wavelengths producing a limb-darkened estimate of —a figure entirely consistent with Michelson's findings eighty years earlier. At the time of its publication, the estimated parallax from the Hipparcos mission was, yielding an estimated radius for Betelgeuse of. However, an infrared interferometric study published in 2009 announced that the star had shrunk by 15% since 1993 at an increasing rate without a significant diminution in magnitude. Subsequent observations suggest that the apparent contraction may be due to shell activity in the star's extended

2019–20 fading.

A pulsating semiregular variable star, Betelgeuse is subject to multiple cycles of increasing and decreasing brightness due to changes in its size and temperature. The astronomers who first noted the dimming of Betelgeuse, Villanova University astronomers Richard Wasatonic and Edward Guinan, and amateur Thomas Calderwood, theorize that a coincidence of a normal 5.9-year light-cycle minimum and a deeper-than-normal 425-day period are the driving factors. Other possible causes are an eruption of gas or dust, or fluctuations in the star’s surface brightness.  By January 2020, Betelgeuse had dimmed by a factor of approximately 2.5 from magnitude 0.5 to 1.5, and reported still fainter in February in "The Astronomer's Telegram" at a record minimum of +1.614, noting that the star is currently the "least luminous and coolest" in the 25 years of their studies and also calculating

Observation.

As a result of its distinctive orange-red color and position within Orion, Betelgeuse is easy to spot with the naked eye in the night sky. It is one of three stars that make up the Winter Triangle asterism, and it marks the center of the Winter Hexagon. At the beginning of January of each year, it can be seen rising in the east just after sunset. Between mid-September to mid-March (best in mid-December), it is visible to virtually every inhabited region of the globe, except in Antarctica at latitudes south of 82°. In May (moderate northern latitudes) or June (southern latitudes), the red supergiant can be seen briefly on the western horizon after sunset, reappearing again a few months later on the eastern horizon before sunrise. In the intermediate period (June–July), it is invisible to the naked eye (visible only with a telescope in daylight), except around midday in Antarctic regions between 70° and 80° south latitude (during polar night, when the Sun is below the horizon).  Betelgeuse is a variable star whose visual magnitude ranges between 0.0 and +1.6. There are periods when it will surpass Rigel to become the sixth brightest star, and occasionally it will be even brighter than Capella. At its faintest Betelgeuse can fall behind Deneb and Beta Crucis, themselves both slightly variable, to be the twentieth-brightest star.  Betelgeuse has a B–V color index of 1.85—a figure which points to its pronounced "redness". The photosphere has an extended atmosphere, which displays strong lines of emission rather than absorption, a phenomenon that occurs when a star is surrounded by a thick gaseous envelope (rather than ionized). This extended gaseous atmosphere has been observed moving toward and away from Betelgeuse, depending on fluctuations in the photosphere. Betelgeuse is the brightest near-infrared source in the sky with a J band magnitude of −2.99; only about 13% of the star's radiant energy is emitted as visible light. If human eyes were sensitive to radiation at all wavelengths, Betelgeuse would appear as the brightest star in the night sky.  Various catalogues list up to nine faint visual companions to Betelgeuse. They are at distances of about one to four arc-minutes and all are fainter than 10th magnitude.  In December 2019, astronomers reported that the star's brightness had significantly decreased and that it may therefore be in the last stages of its evolution. Studies reported more recently, on 22 February 2020, suggest that Betelgeuse may have stopped dimming, and may now be beginning to again brighten, all but ending the current dimming episode. Further studies of the star, reported on 24 February 2020, found no significant change in the infrared over the last 50 years, and seems unrelated to the recent visual fading, suggesting that an impending core collapse may be unlikely. Also, on 24 February 2020, further studies suggest that occluding "large-grain circumstellar dust" may be the most likely explanation for the dimming of the star. On 26 February 2020, astronomers reported large amounts of Titanium(II) oxide (TiO), one of the star's dust precursors, in spectral studies, suggesting that the star may be cooling.

Physical characteristics.

Betelgeuse is a very large, luminous but cool star classified as an M1-2 Ia-ab red supergiant. The letter "M" in this designation means that it is a red star belonging to the M spectral class and therefore has a relatively low photospheric temperature; the "Ia-ab" suffix luminosity class indicates that it is an intermediate-luminosity supergiant, with properties partway between a normal supergiant and a luminous supergiant. Since 1943, the spectrum of Betelgeuse has served as one of the stable anchor points by which other stars are classified.  Uncertainty in the star's surface temperature, diameter, and distance make it difficult to achieve a precise measurement of Betelgeuse's luminosity, but research from 2012 quotes a luminosity of around, assuming a distance of. Studies since 2001 report effective temperatures ranging from 3,250 to 3,690 K. Values outside this range have previously been reported, and much of the variation is believed to be real, due to pulsations in the atmosphere. The star is also a slow rotator and the most recent velocity recorded was —much slower than Antares which has a rotational velocity of. The rotation period depends on Betelgeuse's size and orientation to Earth, but it has been calculated to take to turn on its axis, inclined at an angle of around to Earth.  In 2004, astronomers using computer simulations speculated that even if Betelgeuse is not rotating it might exhibit large-scale magnetic activity in its extended atmosphere, a factor where even moderately strong fields could have a meaningful influence over the star's dust, wind and mass-loss properties. A series of spectropolarimetric observations obtained in 2010 with the Bernard Lyot Telescope at Pic du Midi Observatory revealed the presence of a weak magnetic field at the surface of Betelgeuse, suggesting that the giant convective motions of supergiant stars are able to trigger the onset of a small-scale dynamo effect.

Mass.

Betelgeuse has no known orbital companions, so its mass cannot be calculated by that direct method. Modern mass estimates from theoretical modelling have produced values of, with values of – from older studies. It has been calculated that Betelgeuse began its life as a star of, based

Motion.

The kinematics of Betelgeuse are complex. The age of Class M supergiants with an initial mass of is roughly 10 million years. Starting from its present position and motion a projection back in time would place Betelgeuse around farther from the galactic plane—an implausible location, as there is no star formation region there. Moreover, Betelgeuse's projected pathway does not appear to intersect with the 25 Ori subassociation or the far younger Orion Nebula Cluster (ONC, also known as Ori OB1d), particularly since Very Long Baseline Array astrometry yields a distance from Betelgeuse to the ONC of between 389 and. Consequently, it is likely that Betelgeuse has not always had its current motion through space but has changed course at one time or another, possibly the result of a nearby stellar explosion. An observation by the Herschel Space Observatory in January 2013 revealed that the star's winds

Circumstellar dynamics.

In the late phase of stellar evolution, massive stars like Betelgeuse exhibit high rates of mass loss, possibly as much as every, resulting in a complex circumstellar environment that is constantly in flux. In a 2009 paper, stellar mass loss was cited as the "key to understanding the evolution of the universe from the earliest cosmological times to the current epoch, and of planet formation and the formation of life itself". However, the physical mechanism is not well understood. When Martin Schwarzschild first proposed his theory of huge convection cells, he argued it was the likely cause of mass loss in evolved supergiants like Betelgeuse. Recent work has corroborated this hypothesis, yet there are still uncertainties about the structure of their convection, the mechanism of their mass loss, the way dust forms in their extended atmosphere, and the conditions which precipitate their dramatic finale as a type II supernova. In 2001, Graham

Asymmetric shells.

In addition to the photosphere, six other components of Betelgeuse's atmosphere have now been identified. They are a molecular environment otherwise known as the MOLsphere, a gaseous envelope, a chromosphere, a dust environment and two outer shells (S1 and S2) composed of carbon monoxide (CO). Some of these elements are known to be asymmetric while others overlap.  At about 0.45 stellar radii (~2–) above the photosphere, there may lie a molecular layer known as the MOLsphere or molecular environment. Studies show it to be composed of water vapor and carbon monoxide with an effective temperature of about. Water vapor had been originally detected in the supergiant's spectrum in the 1960s with the two Stratoscope projects but had been ignored for decades. The MOLsphere may also

Supersonic bow shock.

Betelgeuse is travelling supersonically through the interstellar medium at a speed of (i.e. ~) creating a bow shock. The shock is not created by the star, but by its powerful stellar wind as it ejects vast amounts of gas into the interstellar medium at a speed of, heating the material surrounding the star, thereby making it visible in infrared light. Because Betelgeuse is so bright, it was only in 1997 that the bow shock was first imaged. The cometary structure is estimated to be at least one parsec wide, assuming a distance of 643 light-years.

Life phases.

Betelgeuse is a red supergiant that has evolved from an O-type main sequence star. Its core will eventually collapse, producing a supernova explosion and leaving behind a compact remnant. The details depend on the exact initial mass and other physical properties of that main sequence star.

Main sequence.

The initial mass of Betelgeuse can only be estimated by testing different stellar evolutionary models to match its current observed properties. The unknowns of both the models and the current properties mean that there is considerable uncertainty in Betelgeuse's initial appearance, but its mass is usually estimated to have been in the range of, with modern models finding values of. Its chemical makeup can be reasonably assumed to have been around 70% hydrogen, 28% helium, and 2.4% heavy elements, slightly more metal-rich than

After core hydrogen exhaustion.

Betelgeuse's time spent as a red supergiant can be estimated by comparing mass loss rates to the observed circumstellar material, as well as the abundances of heavy elements at the surface. Estimates range from 20,000 years to a maximum of 140,000 years. Betelgeuse appears to undergo short periods of heavy mass loss and is a runaway star moving rapidly through space, so comparisons of its current mass loss to the total lost mass are difficult. The surface of Betelgeuse shows enhancement of nitrogen, relatively low levels of carbon, and a high proportion of C relative to C, all indicative of a star that has experienced the first dredge-up. However, the first dredge-up occurs soon after a star reaches the red supergiant phase and so this only means that Betelgeuse has been a red supergiant for at least a few thousand years. The best prediction is that Betelgeuse has already spent around 40,000 years

Ethnological attributes.

Spelling and pronunciation.

Betelgeuse has also been spelled "Betelgeux" and, in German, "Beteigeuze" (according to Bode). "Betelgeux" and "Betelgeuze" were used until the early 20th century, when the spelling

Etymology.

Betelgeuse is often mistranslated as "armpit of the central one". In his 1899 work "Star-Names and Their Meanings", American amateur naturalist Richard Hinckley Allen stated the derivation was from the "", which he claimed degenerated into a number of forms including "Bed Elgueze", "Beit Algueze", "Bet El-gueze", "Beteigeuze" and more, to the forms "Betelgeuse", "Betelguese", "Betelgueze" and "Betelgeux". The star was named "Beldengeuze" in the "Alfonsine Tables", and Italian Jesuit priest and astronomer Giovanni Battista Riccioli had called it "Bectelgeuze" or "Bedalgeuze".  Paul Kunitzsch, Professor of Arabic Studies at the University of Munich, refuted Allen's derivation and instead proposed that the full name is a corruption of the Arabic "" meaning "the Hand of "al-Jauzā<nowiki>'"</nowiki>", "i.e.", Orion. European mistransliteration into

Other names.

Other names for Betelgeuse included the Persian'"the Arm", and Coptic'"an Armlet". "" was its Sanskrit name, as part of a Hindu understanding of the constellation as a running antelope or stag. In traditional Chinese astronomy, the name for Betelgeuse is (", the Fourth Star of the constellation of Three Stars") as the Chinese constellation originally referred to the three stars in the girdle of Orion. This constellation was ultimately expanded to ten stars, but the earlier name stuck. In Japan, the Taira, or

Mythology.

With the history of astronomy intimately associated with mythology and astrology before the scientific revolution, the red star, like the planet Mars that derives its name from a Roman war god, has been closely associated with the martial archetype of conquest for millennia, and by extension, the motif of death and rebirth. Other cultures have produced different myths. Stephen R. Wilk has proposed the constellation of Orion could have represented the Greek mythological figure Pelops, who had an artificial shoulder of ivory made for him, with

In popular culture.

As one of the brightest and best-known stars, Betelgeuse has featured in many works of fiction. The star's unusual name inspired the title of the 1988 film "Beetlejuice", and script writer Michael McDowell was impressed by how many people made the connection. In the popular science fiction series "The Hitchhiker's Guide to the Galaxy" by Douglas Adams, Ford Prefect was from "a small planet somewhere in the vicinity of Betelgeuse."  Two American navy ships were named after the star, both of them World War II vessels, the launched in 1939 and launched in 1944.

Table of angular diameter estimates.

This table provides a non-exhaustive list of angular measurements conducted since 1920. Also included is a column providing a current range of radii for each study based on Betelgeuse's most recent distance estimate (Harper "et al.") of.

Betelgeuse is usually the tenth-brightest star in the night sky and, after Rigel, the second-brightest in the constellation of Orion. It is a distinctly reddish semiregular variable star whose apparent magnitude, varying between +0.0 and +1.6, has the widest range displayed by any first-magnitude star. At near-infrared wavelengths, Betelgeuse is the brightest star in the night sky. Its Bayer designation is α Orionis, Latinised to Alpha Orionis and abbreviated Alpha Ori or α Ori.

Betelgeuse je po Rigelu (beta Ori) druhá nejjasnější hvězda v souhvězdí Orionu. Pouhým okem je rozeznatelná i její oranžovo-červená barva. Zdánlivá jasnost se časem mění – kolísá v rozmezí 0,3 až 1,3 mag (průměr 0,58 (Budeme-li brát v úvahu tento průměr, je Betelgeuze nejjasnější hvězdou z těch, které nejsou nejjasnější ve svém souhvězdí.)), jedná se totiž o polopravidelnou proměnnou hvězdu. Je jedním z vrcholů asterismu Zimní trojúhelník spolu se Siriem (alfa CMa) a Prokyonem (alfa CMi).


Location.

Petrovice is located in the west of Czech Republic near its border with Poland (the border is approximately north of the village). The national capital, Prague, lies approximately to the west. Although Petrovice is in the Moravian-Silesian Region it shares its western border with the Olomouc Region. Petrovice is on the 457 road from Janov to Zlate Hory.

Geography.

Petrovice is located in the most western and mountainous part of the Osoblažsko microregion in the Petrovický stream valley. The mountains of Zlatohorská upland rise steeply from the banks of the stream to reach in height. The peak of Biskupska kupa (Bishop's Hill) is approximately to the northwest of the village. The village, which rests along the eastern bank of the Osoblaha stream, is immediately surrounded by green terraced fields and forests.

Petrovice viewing tower.

The Petrovice viewing tower, the oldest stone tower in the Jeseníky mountains, is located on mount Biskupská kupa and is high. It was built in 1898 by the German tourist association, MSSGV, to commemorate 50 years of the reign of Franz Joseph I. The tower was closed to the public after World War II and was then used as a television transmitter. In 1996, reconstruction and restoration began on the tower before its opening to the public on its centenary in 1998. Since 2006, the tower has housed a post office. In good weather, one can see Wroclaw and the peaks of High Tatras in Slovakia.

Architecture.

Petrovice village contains examples of folk architecture, such as country houses (numbered 39, 115, 130 and 137). The village is dominated by the single-aisle Church of St. Roch, built in the late 1600s CE.

Nearby attractions.

Petrovice has facilities for skiers that include a ski lift at the end of the village. Heřmanovice municipality is a protected conservation village because of a uniquely preserved complex of Jeseníky residential folk architecture of the Eastern Sudeten type. The town of Zlaté Hory has an outdoor mining museum (Zlatorudné mills), as well as a ski resort below mount Příčná hora.

Petrovice () is a village and municipality in Bruntál District in the Moravian-Silesian Region of the Czech Republic. Petrovice is a village conservation area and its rural character make it a popular holiday destination. The village population is 131.

Obec Petrovice (německy "Petersdorf") se nachází v okrese Bruntál v Moravskoslezském kraji. Žije zde obyvatel. Celá zástavba obce, jakož i téměř celý její katastr leží na Moravě, respektive je součástí moravské enklávy Osoblažska, ale úzký pruh území podél její západní hranice patřil dříve ke Zlatým Horám a tak obec zasahuje i do Slezska. Zástavba obce těsně navazuje na zástavbu sousední obce Janova, s níž tvoří prakticky jednotný urbanistický sídelní celek.