General characteristics.

"Y. pestis" is a nonmotile, stick-shaped, facultative anaerobic bacterium with bipolar staining (giving it a safety pin appearance) that produces an antiphagocytic slime layer. Similar to other "Yersinia" species, it tests negative for urease, lactose fermentation, and indole. Its closest relative is the gastrointestinal pathogen "Yersinia pseudotuberculosis", and more distantly "Yersinia enterocolitica".

Genome.

A complete genomic sequence is available for two of the three subspecies of "Y. pestis": strain KIM (of biovar "Y. p. medievalis"), and strain CO92 (of biovar "Y. p. orientalis", obtained from a clinical isolate in the United States). As of 2006, the genomic sequence of a strain of biovar "Antiqua" has been recently completed. Similar to the other pathogenic strains, signs exist of loss of function mutations. The chromosome of strain KIM is 4,600,755 base pairs long; the chromosome of strain CO92 is 4,653,728 base pairs long. Like "Y. pseudotuberculosis" and "Y. enterocolitica", "Y. pestis" is host to the plasmid pCD1. It also hosts two other plasmids, pPCP1 (also called pPla or pPst) and pMT1 (also called pFra) that are not carried by the other "Yersinia" species. pFra codes for a phospholipase D that is important for the ability of "Y. pestis" to be transmitted by fleas. pPla codes for a protease, Pla, that activates plasmin in human hosts and is a very important virulence factor for pneumonic plague. Together, these plasmids, and a pathogenicity island called HPI, encode several proteins that cause the pathogenesis, for which "Y. pestis" is famous. Among other things, these virulence factors are required for bacterial adhesion and injection of proteins into the host cell, invasion of bacteria in the host cell (via a type-III secretion system), and acquisition and binding of iron harvested from red blood cells (by siderophores). "Y. pestis" is thought to be descended from "Y. pseudotuberculosis", differing only in the presence of specific virulence plasmids.  A comprehensive and comparative proteomics analysis of "Y. pestis" strain KIM was performed in 2006. The analysis focused on the transition to a growth condition mimicking growth in host cells.

Small noncoding RNA.

Numerous bacterial small noncoding RNAs have been identified to play regulatory functions. Some can regulate the virulence genes. Some 63 novel putative sRNAs were identified through deep sequencing of the "Y. pestis" sRNA-ome. Among them was "Yersinia"-specific (also present in "Y. pseudotuberculosis" and "Y. enterocolitica") Ysr141 ("Yersinia" small RNA 141). Ysr141 sRNA was shown to regulate the synthesis of the type III secretion system (T3SS) effector protein YopJ. The Yop-Ysc T3SS is a critical component of virulence for "Yersinia" species. Many novel sRNAs were identified from "Y. pestis" grown "in vitro" and in the infected lungs of mice suggesting they play role in bacterial physiology or pathogenesis. Among them sR035 predicted to pair with SD region and transcription initiation site of a thermo-sensitive regulator "ymoA," and "sR084" predicted to pair with "fur", ferric uptake regulator.

Pathogenesis and immunity.

In the urban and sylvatic (forest) cycles of "Y. pestis," most of the spreading occurs between rodents and fleas. In the sylvatic cycle, the rodent is wild, but in the urban cycle, the rodent is primarily the brown rat ("Rattus norvegicus"). In addition, "Y. pestis" can spread from the urban environment and back. Transmission to humans is usually through the bite of infected fleas. If the disease has progressed to the pneumonic form, humans can spread the bacterium to others by coughing, vomiting, and possibly sneezing.

In reservoir hosts.

Several species of rodents serve as the main reservoir for "Y. pestis" in the environment. In the steppes, the natural reservoir is believed to be principally the marmot. In the western United States, several species of rodents are thought to maintain "Y. pestis". However, the expected disease dynamics have not been found in any rodent. Several species of rodents are known to have a variable resistance, which could lead to an asymptomatic carrier status. Evidence indicates fleas from other mammals have a role in human plague outbreaks.  The lack of knowledge of the dynamics of plague in mammal species is also true among susceptible rodents such as the black-tailed prairie dog ("Cynomys ludovicianus"), in which plague can cause colony collapse, resulting in a massive effect on prairie food webs. However, the transmission dynamics within prairie dogs do not follow the dynamics of blocked fleas; carcasses, unblocked fleas, or another vector could possibly be important, instead.  In other regions of the world, the reservoir of the infection is not clearly identified, which complicates prevention and early-warning programs. One such example was seen in a 2003 outbreak in Algeria. Domestic house cats are susceptible to plague. Their symptoms are similar to those experienced by humans. Cats infected with plague can infect people through bites, scratches, coughs, or sneezes.

Vector.

The transmission of "Y. pestis" by fleas is well characterized. Initial acquisition of "Y. pestis" by the vector occurs during feeding on an infected animal. Several proteins then contribute to the maintenance of the bacteria in the flea digestive tract, among them the hemin storage system and "Yersinia" murine toxin (Ymt). Although Ymt is highly toxic to rodents and was once thought to be produced to ensure reinfection of new hosts, it is important for the survival of "Y. pestis" in fleas.  The hemin storage system plays an important role in the transmission of "Y. pestis" back to a mammalian host. While in the insect vector, proteins encoded by hemin storage system genetic loci induce biofilm formation in the proventriculus, a valve connecting the midgut to the esophagus. Aggregation in the biofilm inhibits feeding, as a mass of clotted blood and bacteria forms (referred to as "Bacot's block" after entomologist A.W. Bacot, the first to describe this phenomenon). Transmission of "Y. pestis" occurs during the futile attempts of the flea to feed. Ingested blood is pumped into the esophagus, where it dislodges bacteria lodged in the proventriculus, which is regurgitated back into the host circulatory system.

In humans and other susceptible hosts.

Pathogenesis due to "Y. pestis" infection of mammalian hosts is due to several factors, including an ability of these bacteria to suppress and avoid normal immune system responses such as phagocytosis and antibody production. Flea bites allow for the bacteria to pass the skin barrier. "Y. pestis" expresses a plasmin activator that is an important virulence factor for pneumonic plague and that might degrade on blood clots to facilitate systematic invasion. Many of the bacteria's virulence factors are antiphagocytic in nature. Two important antiphagocytic antigens, named F1 (fraction 1) and V or LcrV, are both important for virulence. These antigens are produced by the bacterium at normal human body temperature. Furthermore, "Y. pestis" survives and produces F1 and V antigens while it is residing within white blood cells such as monocytes, but not in neutrophils. Natural or induced immunity is achieved by the production of specific opsonic antibodies against F1 and V antigens; antibodies against F1 and V induce phagocytosis by neutrophils.  In addition, the type-III secretion system (T3SS) allows "Y. pestis" to inject proteins into macrophages and other immune cells. These T3SS-injected proteins, called "Yersinia" outer proteins (Yops), include Yop B/D, which form pores in the host cell membrane and have been linked to cytolysis. The YopO, YopH, YopM, YopT, YopJ, and YopE are injected into the cytoplasm of host cells by T3SS into the pore created in part by YopB and YopD. The injected Yops limit phagocytosis and cell signaling pathways important in the innate immune system, as discussed below. In addition, some "Y. pestis" strains are capable of interfering with immune signaling (e.g., by preventing the release of some cytokines).  "Y. pestis" proliferates inside lymph nodes, where it is able to avoid destruction by cells of the immune system such as macrophages. The ability of "Y. pestis" to inhibit phagocytosis allows it to grow in lymph nodes and cause lymphadenopathy. YopH is a protein tyrosine phosphatase that contributes to the ability of "Y. pestis" to evade immune system cells. In macrophages, YopH has been shown to dephosphorylate p130Cas, Fyb (Fyn binding protein) SKAP-HOM and Pyk, a tyrosine kinase homologous to FAK. YopH also binds the p85 subunit of phosphoinositide 3-kinase, the Gab1, the Gab2 adapter proteins, and the Vav guanine nucleotide exchange factor.  YopE functions as a GTPase-activating protein for members of the Rho family of GTPases such as RAC1. YopT is a cysteine protease that inhibits RhoA by removing the isoprenyl group, which is important for localizing the protein to the cell membrane. YopE and YopT has been proposed to function to limit YopB/D-induced cytolysis. This might limit the function of YopB/D to create the pores used for Yop insertion into host cells and prevent YopB/D-induced rupture of host cells and release of cell contents that would attract and stimulate immune system responses.  YopJ is an acetyltransferase that binds to a conserved α-helix of MAPK kinases. YopJ acetylates MAPK kinases at serines and threonines that are normally phosphorylated during activation of the MAP kinase cascade. YopJ is activated in eukaryotic cells by interaction with target cell phytic acid (IP6). This disruption of host cell protein kinase activity causes apoptosis of macrophages, and this is proposed to be important for the establishment of infection and for evasion of the host immune response. YopO is a protein kinase also known as "Yersinia" protein kinase A (YpkA). YopO is a potent inducer of human macrophage apoptosis.  Depending on which form of the plague with which the individual becomes infected, the plague develops a different illness; however, the plague overall affects the host cell’s ability to communicate with the immune system, hindering the body to bring phagocytic cells to the area of infection.  "Y. pestis" is a versatile killer. In addition to rodents and humans, it is known to have killed dogs, cats, camels, chickens, and pigs.

Immunity.

A formalin-inactivated vaccine was in the past available in the United States for adults at high risk of contracting the plague until removal from the market by the Food and Drug Administration. It was of limited effectiveness and could cause severe inflammation. Experiments with genetic engineering of a vaccine based on F1 and V antigens are underway and show promise. However, bacteria lacking antigen F1 are still virulent, and the V antigens are sufficiently variable such that vaccines composed of these antigens may not be fully protective. The United States Army Medical Research Institute of Infectious Diseases has found that an experimental F1/V antigen-based vaccine protects crab-eating macaques, but fails to protect African green monkey species. A systematic review by the Cochrane Collaboration found no studies of sufficient quality to make any statement on the efficacy of the vaccine.

Isolation and identification.

In 1894, two bacteriologists, Alexandre Yersin of Switzerland and Kitasato Shibasaburō of Japan, independently isolated in Hong Kong the bacterium responsible for the Third Pandemic. Though both investigators reported their findings, a series of confusing and contradictory statements by Kitasato eventually led to the acceptance of Yersin as the primary discoverer of the organism. Yersin named it "Pasteurella pestis" in honor of the Pasteur Institute, where he worked. In 1967, it was moved to a new genus and renamed "Yersinia pestis" in his honor. Yersin also noted that rats were affected by plague not only during plague epidemics, but also often preceding such epidemics in humans and that plague was regarded by many locals as a disease of rats; villagers in China and India asserted that when large numbers of rats were found dead, plague outbreaks soon followed.  In 1898, French scientist Paul-Louis Simond (who had also come to China to battle the Third Pandemic) discovered the rat–flea vector that drives the disease. He had noted that persons who became ill did not have to be in close contact with each other to acquire the disease. In Yunnan, China, inhabitants would flee from their homes as soon as they saw dead rats, and on the island of Formosa (Taiwan), residents considered the handling of dead rats heightened the risks of developing plague. These observations led him to suspect that the flea might be an intermediary factor in the transmission of plague, since people acquired plague only if they were in contact with rats that had died less than 24 hours before. In a now classic experiment, Simond demonstrated how a healthy rat died of the plague after infected fleas had jumped to it from a rat that had recently died of the plague. The outbreak spread to Chinatown, San Francisco, from 1900 to 1904 and then to Oakland and the East Bay from 1907 to 1909. It has been present in the rodents of western North America ever since, as fear of the consequences of the outbreak on trade caused authorities to hide the dead of the Chinatown residents long enough for the disease to be passed to widespread species of native rodents in outlying areas.

Ancient DNA evidence.

In 2018, the emergence and spread of the pathogen during the Neolithic decline (as far back as 6,000 years ago) was published. A site in Sweden was the source of the DNA evidence and trade networks were proposed as the likely avenue of spread rather than migrations of populations.  DNA evidence published in 2015 indicates "Y. pestis" infected humans 5,000 years ago in Bronze Age Eurasia, but genetic changes that made it highly virulent did not occur until about 4,000 years ago. The highly virulent version capable of transmission by fleas through rodents, humans, and other mammals was found in two individuals associated with the Srubnaya culture from the Samara region in Russia from around 3,800 years ago and an Iron Age individual from Kapan, Armenia from around 2,900 years ago. This indicates that at least two lineages of "Y. pestis" were circulating during the Bronze Age in Eurasia. The "Y. pestis" bacterium has a relatively large number of nonfunctioning genes and three "ungainly" plasmids, suggesting an origin less than 20,000 years ago.  Three main strains are recognised: "Y. p. antiqua", which caused a plague pandemic in the sixth century; "Y. p. medievalis", which caused the Black Death and subsequent epidemics during the second pandemic wave; and "Y. p. orientalis", which is responsible for current plague outbreaks.  Plague causes a blockage in the proventriculus of the flea by forming a biofilm. The biofilm formation is induced by the ingestion of blood. The presence of a biofilm seems likely to be required for stable infection of the flea. It has been suggested that a bacteriophage – Ypφ – may have been responsible for increasing the virulence of this organism.

Recent events.

In 2008, the plague was commonly found in sub-Saharan Africa and Madagascar, areas that accounted for over 95% of the reported cases.  In September 2009, the death of Malcolm Casadaban, a molecular genetics professor at the University of Chicago, was linked to his work on a weakened laboratory strain of "Y. pestis". Hemochromatosis was hypothesised to be a predisposing factor in Casadaban's death from this attenuated strain used for research.  In 2010, researchers in Germany definitely established, using PCR evidence from samples obtained from Black Death victims, that "Y. pestis" was the cause of the medieval Black Death.  In 2011, the first genome of "Y. pestis" isolated from Black Death victims was published, and concluded that this medieval strain was ancestral to most modern forms of "Y. pestis".  In 2015, "Cell" published results from a study of ancient graves. Plasmids of "Y. pestis" were detected in archaeological samples of the teeth of seven Bronze Age individuals, in the Afanasievo culture in Siberia, the Corded Ware culture in Estonia, the Sintashta culture in Russia, the Unetice culture in Poland, and the Andronovo culture in Siberia.  On September 8, 2016, the "Y. pestis" bacterium was identified from DNA in teeth found at a Crossrail building site in London. The human remains were found to be victims of the Great Plague of London, which lasted from 1665 to 1666.  On January 15, 2018, researchers at the University of Oslo and the University of Ferrara suggested that humans and their parasites were the biggest carriers of the plague.  Two cases of pneumonic plague were diagnosed at a hospital in Beijing's Chaoyang district on 13 November 2019, prompting fears of an outbreak. Doctors diagnosed a middle-aged man with fever, who had complained of difficulty breathing for some ten days, accompanied by his wife with similar symptoms. Police quarantined the emergency room at the hospital and controls were placed on Chinese news aggregators. On the 18th, a third case was reported in a 55-year-old male from Xilingol League, one of the twelve Mongolic autonomous regions in Northern China. The patient received treatment and 28 symptomless contacts were placed in quarantine.

Yersinia pestis (formerly "Pasteurella pestis") is a gram-negative, non-motile, rod-shaped, coccobacillus bacterium, with no spores. It is a facultative anaerobic organism that can infect humans via the Oriental rat flea ("Xenopsylla cheopis"). It causes the disease plague, which takes three main forms: pneumonic, septicemic, and bubonic.

Yersinia pestis est une bactérie à Gram négatif du genre "Yersinia". Elle est responsable de la peste. Elle fut découverte en 1894 par Alexandre Yersin, un bactériologiste franco-suisse travaillant pour l'Institut Pasteur, durant une épidémie de peste à Hong Kong, en même temps que Kitasato Shibasaburō mais séparément. Kitasato tout d'abord la baptisa Pasteurella pestis en l'honneur de Ce n'est que plus tard qu'elle prit son nom actuel, en hommage à Yersin.


Life.

Karl Schwarzschild was born on the 9th of October 1873 in Frankfurt on Main to Jewish parents. His father was active in the business community of the city, and the family had ancestors in the city dating back to the sixteenth century. Karl attended a Jewish primary school until 11 years of age. He was something of a child prodigy, having two papers on binary orbits (celestial mechanics) published before he was sixteen. He studied at Strasbourg and Munich, obtaining his doctorate in 1896 for a work on Henri Poincaré's theories.  From 1897, he worked as assistant at the Kuffner Observatory in Vienna.  From 1901 until 1909 he was a professor at the prestigious institute at Göttingen, where he had the opportunity to work with some significant figures, including David Hilbert and Hermann Minkowski. Schwarzschild became the director of the observatory in Göttingen. He married Else Rosenbach, the daughter of a professor of surgery at Göttingen, in 1909, and later that year moved to Potsdam, where he took up the post of director of the Astrophysical Observatory. This was then the most prestigious post available for an astronomer in Germany. He and Else had three children, Agathe (who was a Classics professor at the University of Otago in Dunedin, New Zealand), Martin (who went on to become a professor of astronomy at Princeton University), and Alfred. From 1912, Schwarzschild was a member of the Prussian Academy of Sciences.  At the outbreak of World War I in 1914 he joined the German army, despite being over 40 years old. He served on both the western and eastern fronts, rising to the rank of lieutenant in the artillery.  While serving on the front in Russia in 1915, he began to suffer from a rare and painful autoimmune skin disease called pemphigus. Nevertheless, he managed to write three outstanding papers, two on the theory of relativity and one on quantum theory. His papers on relativity produced the first exact solutions to the Einstein field equations, and a minor modification of these results gives the well-known solution that now bears his name — the Schwarzschild metric.  Schwarzschild's struggle with pemphigus may have eventually led to his death on 11 May 1916.

Work.

Thousands of dissertations, articles, and books have since been devoted to the study of Schwarzschild's solutions to the Einstein field equations. However, although Schwarzschild's best known work lies in the area of general relativity, his research interests were extremely broad, including work in celestial mechanics, observational stellar photometry, quantum mechanics, instrumental astronomy, stellar structure, stellar statistics, Halley's comet, and spectroscopy.  Some of his particular achievements include measurements of variable stars, using photography, and the improvement of optical systems, through the perturbative investigation of geometrical aberrations.

Physics of photography.

While at Vienna in 1897, Schwarzschild developed a formula, now known as the Schwarzschild law, to calculate the optical density of photographic material. It involved an exponent now known as the Schwarzschild exponent, which is the formula_1 in the formula:  formula_2  (where formula_3 is optical density of exposed photographic emulsion, a function of formula_4, the intensity of the source being observed, and formula_5, the exposure time, with formula_1 a constant). This formula was important for enabling more accurate photographic measurements of the intensities of faint astronomical sources.

Electrodynamics.

According to Wolfgang Pauli (Theory of relativity), Schwarzschild is the first to introduce the correct Lagrangian formalism of the electromagnetic field as  formula_7  where formula_8 are the electric and magnetic field, formula_9 is the vector potential and formula_10 is the electric potential.  He also introduced a field free variational formulation of electrodynamics (also known as "action at distance" or "direct interparticle action") based only on the world line of particles as  formula_11  where formula_12 are the world lines of the particle, formula_13 the (vectorial) arc element along the world line. Two points on two world lines contribute to the Lagrangian (are coupled) only if they are a zero Minkowskian distance (connected by a light ray), hence the term formula_14. The idea was further developed by Tetrode and Fokker in the 1920s and Wheeler and Feynman in the 1940s and constitutes an alternative/equivalent formulation of electrodynamics.

Relativity.

Einstein himself was pleasantly surprised to learn that the field equations admitted exact solutions, because of their "prima facie" complexity, and because he himself had only produced an approximate solution. Einstein's approximate solution was given in his famous 1915 article on the advance of the perihelion of Mercury. There, Einstein used rectangular coordinates to approximate the gravitational field around a spherically symmetric, non-rotating, non-charged mass. Schwarzschild, in contrast, chose a more elegant "polar-like" coordinate system and was able to produce an exact solution which he first set down in a letter to Einstein of 22 December 1915, written while Schwarzschild was serving in the war stationed on the Russian front. Schwarzschild concluded the letter by writing: "As you see, the war treated me kindly enough, in spite of the heavy gunfire, to allow me to get away from it all and take this walk in the land of your ideas." In 1916, Einstein wrote to Schwarzschild on this result:  Schwarzschild's second paper, which gives what is now known as the "Inner Schwarzschild solution" (in German: "innere Schwarzschild-Lösung"), is valid within a sphere of homogeneous and isotropic distributed molecules within a shell of radius r=R. It is applicable to solids; incompressible fluids; the sun and stars viewed as a quasi-isotropic heated gas; and any homogeneous and isotropic distributed gas.  Schwarzschild's first (spherically symmetric) solution "does not" contain a coordinate singularity on a surface that is now named after him. In Schwarzschild coordinates, this singularity lies on the sphere of points at a particular radius, called the Schwarzschild radius:  where "G" is the gravitational constant, "M" is the mass of the central body, and "c" is the speed of light in a vacuum. In cases where the radius of the central body is less than the Schwarzschild radius, formula_16 represents the radius within which all massive bodies, and even photons, must inevitably fall into the central body (ignoring quantum tunnelling effects near the boundary). When the mass density of this central body exceeds a particular limit, it triggers a gravitational collapse which, if it occurs with spherical symmetry, produces what is known as a Schwarzschild black hole. This occurs, for example, when the mass of a neutron star exceeds the Tolman-Oppenheimer-Volkoff limit (about three solar masses).

Cultural references.

Karl Schwarzschild appears as a character in the science fiction short story "Schwarzschild Radius" (1987) by Connie Willis.  Schwarzschild's Cat is a comic on XKCD.com comparing the size and cuteness of cats.

Karl Schwarzschild (; 9 October 1873 – 11 May 1916) was a German physicist and astronomer. He was also the father of astrophysicist Martin Schwarzschild.

Karl Siegmund Schwarzschild, né à Francfort-sur-le-Main (Province de Hesse-Nassau, Prusse, Empire allemand) le, mort à Potsdam (Province de Brandebourg, Prusse, Empire allemand) le, est un astrophysicien allemand.


Terminology.

The terms "upper case" and "lower case" may be written as two consecutive words, connected with a hyphen ("upper-case" and "lower-case" particularly if they pre-modify another noun), or as a single word ("uppercase" and "lowercase"). These terms originated from the common layouts of the shallow drawers called "type cases" used to hold the movable type for letterpress printing. Traditionally, the capital letters were stored in a separate shallow tray or "case" that was located above the case that held the small letters. "Majuscule" ( or ), for palaeographers, is technically any script in which the letters have very few or very short ascenders and descenders, or none at all (for example, the majuscule scripts used in the Codex Vaticanus Graecus 1209, or the Book of Kells). By virtue of their visual impact, this made the term majuscule an apt descriptor for what much later came to be more commonly referred to as uppercase letters. "Minuscule" refers to lower-case letters. The word is often spelled "miniscule", by association with the unrelated word "miniature" and the prefix "mini-". This has traditionally been regarded as a spelling mistake (since "minuscule" is derived from the word "minus"), but is now so common that some dictionaries tend to accept it as a nonstandard or variant spelling. "Miniscule" is still less likely, however, to be used in reference to lower-case letters.

Typographical considerations.

The glyphs of lower-case letters can resemble smaller forms of the upper-case glyphs restricted to the base band (e.g. "C/c" and "S/s", cf. small caps) or can look hardly related (e.g. "D/d" and "G/g"). Here is a comparison of the upper and lower case variants of each letter included in the English alphabet (the exact representation will vary according to the typeface and font used):  Typographically, the basic difference between the majuscules and minuscules is not that the majuscules are big and minuscules small, but that the majuscules generally have the same height (although, depending on the typeface, there may be some exceptions, particularly with "Q" and sometimes "J" having a descending element; also, various diacritics can add to the normal height of a letter).  There is more variation in the height of the minuscules, as some of them have parts higher (ascenders) or lower (descenders) than the typical size. Normally, "b, d, f, h, k, l, t " are the letters with ascenders, and "g, j, p, q, y" are the ones with descenders. In addition, with old-style numerals still used by some traditional or classical fonts, "6" and "8" make up the ascender set, and "3, 4, 5, 7" and "9" the descender set.

Bicameral script.

Writing systems using two separate cases are "bicameral scripts". Languages that use the Latin, Cyrillic, Greek, Coptic, Armenian, Adlam, Warang Citi, Cherokee, and Osage scripts use letter cases in their written form as an aid to clarity and legibility. Another bicameral script, which is not used for any modern languages, is Deseret. The Georgian alphabet has several variants, and there were attempts to use them as different cases, but the modern written Georgian language does not distinguish case.  Many other writing systems make no distinction between majuscules and minuscules a system called unicameral script or unicase. This includes most syllabic and other non-alphabetic scripts.  In scripts with a case distinction, lower case is generally used for the majority of text; capitals are used for capitalisation and emphasis when bold is not available. Acronyms (and particularly initialisms) are often written in all-caps, depending on various factors.

Capitalisation.

Capitalisation is the writing of a word with its first letter in uppercase and the remaining letters in lowercase. Capitalisation rules vary by language and are often quite complex, but in most modern languages that have capitalisation, the first word of every sentence is capitalised, as are all proper nouns.  Capitalisation in English, in terms of the general orthographic rules independent of context (e.g. title vs. heading vs. text), is universally standardised for formal writing. Capital letters are used as the first letter of a sentence, a proper noun, or a proper adjective. The names of the days of the week and the names of the months are also capitalised, as are the first-person pronoun "I" and the interjection "O" (although the latter is uncommon in modern usage, with "oh" being preferred). There are a few pairs of words of different meanings whose only difference is capitalisation of the first letter. Honorifics and personal titles showing rank or prestige are capitalised when used together with the name of the person (for example, "Mr. Smith", "Bishop O'Brien", "Professor Moore") or as a direct address, but normally not when used alone and in a more general sense. It can also be seen as customary to capitalise any word in some contexts even a pronoun referring to the deity of a monotheistic religion.  Other words normally start with a lower-case letter. There are, however, situations where further capitalisation may be used to give added emphasis, for example in headings and publication titles (see below). In some traditional forms of poetry, capitalisation has conventionally been used as a marker to indicate the beginning of a line of verse independent of any grammatical feature.  Other languages vary in their use of capitals. For example, in German all nouns are capitalised (this was previously common in English as well, mainly in the 17th and 18th centuries), while in Romance and most other European languages the names of the days of the week, the names of the months, and adjectives of nationality, religion, and so on normally begin with a lower-case letter. On the other hand, in some languages it is customary to capitalise formal polite pronouns, for example "De", "Dem" (Danish), "Sie", "Ihnen" (German), and "Vd" or "Ud" (short for "usted" in Spanish).  Informal communication, such as texting, instant messaging or a handwritten sticky note, may not bother to follow the conventions concerning capitalisation, but that is because its users usually do not expect it to be formal.

Related phenomena.

Similar orthographic and graphostylistic conventions are used for emphasis or following language-specific or other rules, including:

Stylistic or specialised usage.

Case styles.

In English, a variety of case styles are used in various circumstances:

Headings and publication titles.

In English-language publications, various conventions are used for the capitalisation of words in publication titles and headlines, including chapter and section headings. The rules differ substantially between individual house styles.  The convention followed by many British publishers (including scientific publishers, like "Nature", magazines, like "The Economist" and "New Scientist", and newspapers, like "The Guardian" and "The Times") and also U.S. newspapers, is sentence-style capitalisation in headlines, i.e. capitalisation follows the same rules that apply for sentences. This convention is usually called "sentence case". It may also be applied to publication titles, especially in bibliographic references and library catalogues. An example of a global publisher whose English-language house style prescribes sentence-case titles and headings is the International Organization for Standardization (ISO).  For publication titles it is, however, a common typographic practice among both British and U.S. publishers to capitalise significant words (and in the United States, this is often applied to headings, too). This family of typographic conventions is usually called "title case". For example, R. M. Ritter's "Oxford Manual of Style" (2002) suggests capitalising "the first word and all nouns, pronouns, adjectives, verbs and adverbs, but generally not articles, conjunctions and short prepositions". This is an old form of emphasis, similar to the more modern practice of using a larger or boldface font for titles. The rules which prescribe which words to capitalise are not based on any grammatically inherent correct–incorrect distinction and are not universally standardised; they differ between style guides, although most style guides tend to follow a few strong conventions, as follows:  Title case is widely used in many English-language publications, especially in the United States. However, its conventions are sometimes not followed strictly especially in informal writing.  In creative typography, such as music record covers and other artistic material, all styles are commonly encountered, including all-lowercase letters and special case styles, such as studly caps (see below). For example, in the wordmarks of video games it is not uncommon to use stylised upper-case letters at the beginning and end of a title, with the intermediate letters in small caps or lower case (e.g.,,, and ).

Multi-word proper nouns.

Single-word proper nouns are capitalised in formal written English, unless the name is intentionally stylised to break this rule (such as the first or last name of danah boyd).  Multi-word proper nouns include names of organisations, publications, and people. Often the rules for "title case" (described in the previous section) are applied to these names, so that non-initial articles, conjunctions, and short prepositions are lowercase, and all other words are uppercase. For example, the short preposition "of" and the article "the" are lowercase in "Steering Committee of the Finance Department". Usually only capitalised words are used to form an acronym variant of the name, though there is some variation in this.  With personal names, this practice can vary (sometimes all words are capitalised, regardless of length or function), but is not limited to English names. Examples include the English names Tamar of Georgia and Catherine the Great, "van" and "der" in Dutch names, "von" and "zu" in German, "de", "los", and "y" in Spanish names, "de" or "d'" in French names, and "ibn" in Arabic names.  Some surname prefixes also affect the capitalisation of the following internal letter or word, for example "Mac" in Celtic names and "Al" in Arabic names.

Special case styles.

Some case styles are not used in standard English, but are common in computer programming, product branding, or other specialised fields:

Unit symbols in the metric system.

In the International System of Units (SI), a letter usually has different meanings in upper and lower case when used as a unit symbol. Generally, unit symbols are written in lower case, but if the name of the unit is derived from a proper noun, the first letter of the symbol is capitalised (nevertheless, the "name" of the unit, if spelled out, is always considered a common noun and written accordingly):  For the purpose of clarity, the symbol for litre can optionally be written in upper case even though the name is not derived from a proper noun:  The letter case of a prefix symbol is determined independently of the unit symbol to which it is attached. Lower case is used for all submultiple prefix symbols and the small multiple prefix symbols up to "k" (for kilo, meaning 10 = 1000 multiplier), whereas upper case is used for larger multipliers:

Case folding and case conversion.

In the character sets developed for computing, each upper- and lower-case letter is encoded as a separate character. In order to enable case folding and case conversion, the software needs to link together the two characters representing the case variants of a letter. (Some old character-encoding systems, such as the Baudot code, are restricted to one set of letters, usually represented by the upper-case variants.)  Case-insensitive operations can be said to fold case, from the idea of folding the character code table so that upper- and lower-case letters coincide. The conversion of letter case in a string is common practice in computer applications, for instance to make case-insensitive comparisons. Many high-level programming languages provide simple methods for case conversion, at least for the ASCII character set.  Whether or not the case variants are treated as equivalent to each other varies depending on the computer system and context. For example, user passwords are generally case sensitive in order to allow more diversity and make them more difficult to break. On the other hand, when performing a keyword search, differentiating between the upper and lower case might narrow down the search result too much.

Unicode case folding and script identification.

Unicode defines case folding through the three case-mapping properties of each character: upper case, lower case, and title case (in this context, "title case" relates to ligatures and digraphs encoded as mixed-case single characters, in which the first component is in upper case and the second component in lower case). These properties relate all characters in scripts with differing cases to the other case variants of the character.  As briefly discussed in Unicode Technical Note #26, "In terms of implementation issues, any attempt at a unification of Latin, Greek, and Cyrillic would wreak havoc [and] make casing operations an unholy mess, in effect making all casing operations context sensitive [...]". In other words, while the shapes of letters like A, B, E, H, K, M, O, P, T, X, Y and so on are shared between the Latin, Greek, and Cyrillic alphabets (and small differences in their canonical forms may be considered to be of a merely typographical nature), it would still be problematic for a multilingual character set or a font to provide only a "single" code point for, say, uppercase letter B, as this would make it quite difficult for a wordprocessor to change that single uppercase letter to one of the three different choices for the lower-case letter, the Latin b (U+0062), Greek β (U+03B2) or Cyrillic в (U+0432). Therefore, the corresponding Latin, Greek and Cyrillic upper-case letters (U+0042, U+0392 and U+0412, respectively) are also encoded as separate characters, despite their appearance being basically identical. Without letter case, a "unified European alphabet"such as ABБCГDΔΕЄЗFΦGHIИJ...Z, with an appropriate subset for each languageis feasible; but considering letter case, it becomes very clear that these alphabets are rather distinct sets of symbols.

Methods in word processing.

Most modern word processors provide automated case conversion with a simple click or keystroke. For example, in Microsoft Office Word, there is a dialog box for toggling the selected text through UPPERCASE, then lowercase, then Title Case (actually start caps; exception words must be lowercased individually). The keystroke does the same thing.

Methods in programming.

In some forms of BASIC there are two methods for case conversion: C and C++, as well as any C-like language that conforms to its standard library, provide these functions in the file ctype.h: Case conversion is different with different character sets. In ASCII or EBCDIC, case can be converted in the following way, in C:  This only works because the letters of upper and lower cases are spaced out equally. In ASCII they are consecutive, whereas with EBCDIC they are not; nonetheless the upper-case letters are arranged in the same pattern and with the same gaps as are the lower-case letters, so the technique still works.  Some computer programming languages offer facilities for converting text to a form in which all words are capitalised. Visual Basic calls this "proper case"; Python calls it "title case". This differs from usual title casing conventions, such as the English convention in which minor words are not capitalised.

History.

Originally alphabets were written entirely in majuscule letters, spaced between well-defined upper and lower bounds. When written quickly with a pen, these tended to turn into rounder and much simpler forms. It is from these that the first minuscule hands developed, the half-uncials and cursive minuscule, which no longer stayed bound between a pair of lines. These in turn formed the foundations for the Carolingian minuscule script, developed by Alcuin for use in the court of Charlemagne, which quickly spread across Europe. The advantage of the minuscule over majuscule was improved, faster readability.  In Latin, papyri from Herculaneum dating before 79 CE (when it was destroyed) have been found that have been written in old Roman cursive, where the early forms of minuscule letters "d", "h" and "r", for example, can already be recognised. According to papyrologist Knut Kleve, "The theory, then, that the lower-case letters have been developed from the fifth century uncials and the ninth century Carolingian minuscules seems to be wrong." Both majuscule and minuscule letters existed, but the difference between the two variants was initially stylistic rather than orthographic and the writing system was still basically unicameral: a given handwritten document could use either one style or the other but these were not mixed. European languages, except for Ancient Greek and Latin, did not make the case distinction before about 1300.  The timeline of writing in Western Europe can be divided into four eras:  Traditionally, certain letters were rendered differently according to a set of rules. In particular, those letters that began sentences or nouns were made larger and often written in a distinct script. There was no fixed capitalisation system until the early 18th century. The English language eventually dropped the rule for nouns, while the German language keeps it.  Similar developments have taken place in other alphabets. The lower-case script for the Greek alphabet has its origins in the 7th century and acquired its quadrilinear form (that is, characterized by ascenders and descenders) in the 8th century. Over time, uncial letter forms were increasingly mixed into the script. The earliest dated Greek lower-case text is the Uspenski Gospels (MS 461) in the year 835. The modern practice of capitalising the first letter of every sentence seems to be imported (and is rarely used when printing Ancient Greek materials even today).

Type cases.

The individual type blocks used in hand typesetting are stored in shallow wooden or metal drawers known as "type cases". Each is subdivided into a number of compartments ("boxes") for the storage of different individual letters.  The "Oxford Universal Dictionary on Historical Advanced Proportional Principles" (reprinted 1952) indicates that "case" in this sense (referring to the box or frame used by a compositor in the printing trade) was first used in English in 1588. Originally one large case was used for each typeface, then "divided cases", pairs of cases for majuscules and minuscules, were introduced in the region of today's Belgium by 1563, England by 1588, and France before 1723.  The terms "upper" and "lower" case originate from this division. By convention, when the two cases were taken out of the storage rack and placed on a rack on the compositor's desk, the case containing the capitals and small capitals stood at a steeper angle at the back of the desk, with the case for the small letters, punctuation, and spaces being more easily reached at a shallower angle below it to the front of the desk, hence upper and lower case.  Though pairs of cases were used in English-speaking countries and many European countries in the seventeenth century, in Germany and Scandinavia the single case continued in use.  Various patterns of cases are available, often with the compartments for lower-case letters varying in size according to the frequency of use of letters, so that the commonest letters are grouped together in larger boxes at the centre of the case. The compositor takes the letter blocks from the compartments and places them in a composing stick, working from left to right and placing the letters upside down with the nick to the top, then sets the assembled type in a galley.

Letter case (or just case) is the distinction between the letters that are in larger upper case (also "uppercase", "capital letters", "capitals", "caps", "large letters", or more formally "majuscule") and smaller lower case (also "lowercase", "small letters", or more formally "minuscule") in the written representation of certain languages. The writing systems that distinguish between the upper and lower case have two parallel sets of letters, with each letter in one set usually having an equivalent in the other set. The two case variants are alternative representations of the same letter: they have the same name and pronunciation and are treated identically when sorting in alphabetical order.

Une écriture bicamérale est une écriture comprenant des lettres minuscules et des lettres capitales. Plus précisément, elle oppose deux œils de format (ou « casse ») — et parfois de tracé — différents pour chaque caractère. Par opposition, une écriture dans laquelle il n’existe pas une telle opposition est qualifiée de "monocamérale" ou "unicamérale".


Etymology.

"Yunnan" acts as a place name when the Han Dynasty set "Yunnan County" in modern Xiangyun area. In Tang Dynasty, Xuanzong canonized Piluoge, who is the chief of Nanzhao to be the "King of Yunnan". Because of Nanzhao was originated from Yunnan county. Along with the powerful and prosperous of Nanzhao, "King of Yunnan" controlled more and more areas. "Yunnan" became the common name of this area. Therefore, Yuan Dynasty set "Yunnan Province" after he occupied Dali Kingdom. The province name "Yunnan" continues to this day.  Han Dynasty literature did

History.

Prehistory.

The Yuanmou Man, a "Homo erectus" fossil unearthed by railway engineers in the 1960s, has been determined to be the

Pre-Nanzhao period.

Around the 3rd century BC, the central area of Yunnan around present day Kunming was known as Dian. The Chu general () entered the region from the upper Yangtze River and set himself up as "King of Dian". He and his followers brought into Yunnan an influx of Chinese influence, the start of a long history of migration and cultural expansion.  In 221 BC, Qin Shi Huang unified China and extended his authority south. Commanderies and counties were established in Yunnan. An existing road in Sichuan – the "Five Foot Way" – was extended south to around present day Qujing, in eastern Yunnan. In 109 BC, the Han dynasty invaded Dian during its southern expeditions. Under orders from Emperor Wu, General () was sent south to Yunnan, eventually establishing the Yizhou commandery. By this time, agricultural technology in Yunnan had improved markedly. The local people used bronze tools, plows and kept a variety

Nanzhao period.

Yunnan was settled by several local tribes, clans, and cultures before the 8th century. Around Lake Erhai, namely, the Dali area, there emerged six zhao: Mengzi (), Yuexi (), Langqiong (), Dengdan (), Shilling (), and Mengshe (). Zhao() was an indigenous non-Chinese language term meaning "king" or "kingdom." Among the six regimes Mengshe was located south of the other five; therefore given the new, larger context, it was called Nanzhao (Southern Kingdom).  By the 730s Nanzhao had succeeded in bringing the Erhai Lake–area under its authority. In 738, the western Yunnan was united by Piluoge, the fourth king

Dali Kingdom.

In 937, Duan Siping overthrew the Nanzhao and established the Dali Kingdom. The kingdom was conquered by the Mongol Empire in 1253 after Dali King Duan Xingzhi defected to the Mongols. The Duans incorporated into the Mongol dominion as Maharajas of the new province. The Mongolian prince sent to administer the region with them

Ming and Qing dynasties.

The Ming installed Mu Ying and his family as hereditary aristocrats in Yunnan.  During the Ming and Qing dynasties, large areas of Yunnan were administered under the native chieftain system. Under the Qing dynasty a war with Burma also occurred in the 1760s due to the attempted consolidation of borderlands under local chiefs by both China and Burma.  Yunnan was a destination for Han Chinese during Yuan rule. Colonizers moved into the area during Ming and Qing rule.  During the Ming dynasty, 3 million Han Chinese mostly from Nanjing (before the original Nanjing population was largely replaced by Wu speakers) and some from Shanxi and Hebei settled in Yunnan.  Although largely forgotten, the bloody Panthay Rebellion of the Muslim Hui people and other local minorities against the Manchu rulers of the Qing dynasty caused the deaths of

Post-Imperial.

Yunnan was transformed by the events of Second Sino Japanese War, which caused many east coast refugees and industrial establishments to relocate to the province. It assumed strategic significance, particularly as the Burma Road from Lashio, in Burma to Kunming was a fought over supply line of vital importance to China's war effort.  University faculty and students in the east had originally decamped to Changsha, capital of Hunan. But as the Japanese forces were gaining more territory they eventually bombed Changsha in February 1938. The 800

Naturalists.

Thousands of plant, insect and mammal species were described in the 19th century by scientists of the French National Museum of Natural History, Paris, in connection with permanent settlements of missionaries of the "Missions étrangères de Paris" in north-west Yunnan, among them noticeably Jean-André Soulié and Felix Biet. From 1916 to 1917, Roy Chapman Andrews and Yvette Borup

Geography.

Yunnan is the most southwestern province in China, with the Tropic of Cancer running through its southern part. The province has an area of, 4.1% of the nation's total. The northern part of the province forms part of the Yunnan–Guizhou Plateau. The province borders Guangxi and Guizhou in the east, Sichuan in the north, and the Tibet Autonomous Region in the northwest. It shares a border of with Myanmar (Kachin and Shan States) in the west, Laos (Luang Namtha, Oudomxay, and Phongsaly Provinces) in the south and Vietnam (Hà Giang, Lào Cai, Lai Châu, and Điện Biên Provinces) in the southeast. For practical purposes, all of Yunnan province falls within the Zomia (region) of Asia.

Geology.

Yunnan is at the far eastern edge of the Himalayan uplift, and was pushed up in the Pleistocene, primarily in the Middle Pleistocene, although the uplift continues into the present. The eastern part of the province is a limestone plateau with karst topography and unnavigable rivers flowing through deep mountain gorges. The main surface formations of the plateau are the Lower Permian

Climate.

Yunnan has a generally mild climate with pleasant and fair weather because of the province's location on south-facing mountain slopes, receiving the influence of both the Pacific and Indian oceans, and although the growing period is long, the rugged terrain provides little arable land. See "Agriculture in Yunnan". Under the Köppen climate classification, much of the province lies within the

Topography.

The terrain is largely mountainous, especially in the north and west. A series of high mountain chains spreads across the province. There is a distinct canyon region to the west and a plateau region to the east. Yunnan's major rivers flow through the deep valleys between the mountains.  The average elevation is. The mountains are highest in the north where they reach more than ; in the south they rise no higher than

Borders.

Bordering Chinese provincial-level divisions are Tibet, Sichuan, Guizhou and Guangxi. Starting from the east and working clockwise, bordering countries are

Lakes.

There are several major lakes in Yunnan. The

Rivers.

Yunnan is the source of two rivers, the Xi River (there known as the Nanpan and Hongshui) and the Yuan River. The Hongshui is a principal source stream of the Xi River. Rising as the

Biodiversity.

Yunnan is China's most diverse province, biologically as well as culturally. The province contains snow-capped mountains and true tropical environments, thus supporting an unusually full spectrum of species and vegetation types. The Yunnan camellia ("Camellia reticulata") is the provincial emblem.  During summer, the Great Plateau of Tibet acts as a barrier to monsoon winds, trapping moisture in the province. This gives the alpine flora in particular what one source has called a "lushness found nowhere else".  This topographic range combined with a tropical moisture sustains extremely high biodiversity and high degrees of endemism, probably the richest botanically in the world's temperate regions. Perhaps 17,000 species of higher plants, of which an estimated 2,500 are endemic, can be found in the province. The province is said to

Designation.

Yunnan has

Natural resources.

A main source of wealth lies in its vast mineral resources; indeed, mining is the leading industry in Yunnan. Yunnan has proven deposits of 86 kinds of minerals in 2,700 places. Some 13% of the proved deposits of minerals are the largest of their kind in China, and two-thirds of the deposits are among the largest of their kind in the Yangtze River valley and in south China. Yunnan ranks first in the country in deposits of zinc, lead, tin, cadmium, indium, thallium and crocidolite. Other deposits include iron, coal, copper, gold, mercury, silver, antimony and

Governance.

Administrative divisions.

Yunnan consists of sixteen prefecture-level divisions: eight prefecture-level cities and eight autonomous prefectures:  These 16 prefecture-level divisions are in

Politics.

Secretaries of the CPC Yunnan Committee: The Secretary of the CPC is the highest ranking and most important position in Yunnan. Governors of Yunnan: The Governor

Demographics.

Ethnicity.

Yunnan is noted for a very high level of ethnic diversity. It has the highest number of ethnic groups among the provinces and autonomous regions in China. Among the country's 56 recognised ethnic groups, twenty-five are found in Yunnan. Some 38% of the province population are members of ethnic minorities, including the Yi, Bai, Hani, Tai, Dai, Miao, Lisu, Hui, Lahu, Wa, Nakhi, Yao, Tibetans, Jingpo, Blang, Pumi, Nu, Achang, Jinuo, Mongols, Derung, Manchus, Sui, and Buyei. Several other groups are represented, but they live neither in compact settlements nor do they reach the required threshold of five

Languages.

Most dialects of the Chinese language spoken in Yunnan belong to the southwestern subdivision of the Mandarin group, and are therefore very similar to the dialects of neighbouring Sichuan and Guizhou provinces. Notable features found in many Yunnan dialects include the partial or complete loss of distinction between finals and, as well as the lack of. In addition to the local dialects, most people also speak Standard Chinese ("Putonghua", commonly called "Mandarin"), which is used in the

Literacy.

By the end of 1998, among the province's population, 419,800 had received college education or above, 2.11

Religion.

According to a demographic analysis of religions in Yunnan, as of 2005 the province has around 4 million believers of the five government-sanctioned organised religious doctrines of China, almost 90% of them belonging to the ethnic minorities. Of these:  According to surveys conducted in 2004 and 2007, in those years approximately 32.22% of the province's population

Agriculture.

The region maintains a strong agricultural focus. Agriculture is restricted to the few upland plains, open valleys, and terraced hillsides. Level land for agriculture is extremely scarce and only about 5 percent of the province is under cultivation. Rice is the main crop; corn, barley, wheat, rapeseed, sweet potatoes, soybeans (as a food crop), tea, sugarcane, tobacco, and cotton are also grown. On the steep slopes in the west livestock is raised and timber, a valuable resource, is cut (teak in the southwest).  Yunnan produces most of coffee grown in China (although there are also much smaller plantations in Fujian and Hainan. Large-scale coffee cultivation started in Yunnan in 1988. The most commonly grown variety in the province is catimor.  Tobacco is the main (export) product and makes up a big part of the provincial GDP. Furthermore, Yunnan has a strong competitive potential in the

Economy.

As of the mid-19th century, Yunnan exported birds, brass, tin, gemstones, musk, nuts, and peacock feathers mainly to stores in Guangzhou. They imported silk, wool, and cotton cloth, tobacco and books.  Yunnan is one of China's relatively undeveloped provinces with more poverty-stricken counties than the other provinces. In 1994, about 7 million people lived below the poverty line of less than an annual average income of 300 yuan per capita. They were distributed in the province's 73 counties mainly and financially supported by the central government. With an input of 3.15 billion yuan in 2002, the absolutely poor rural population in the province has been reduced from 4.05 million in 2000 to 2.86 million. The poverty alleviation plan includes five large projects aimed at improving infrastructure facilities. They involve planned attempts at soil improvement, water conservation, electric power, roads, and "green belt" building. Upon the completion of the projects, the province hopes this will alleviate the shortages of grain, water, electric power and roads.  Yunnan lags behind the east coast of China in relation to socio-economic development. However, because of its geographic location the province has comparative advantages in regional and border trade with countries in southeast Asia. The Lancang River (upper reaches of Mekong River) is the waterway to southeast Asia. In recent years land transportation has been improved to strengthen economic and trade co-operation among countries in the Greater Mekong Subregion. Yunnan's abundance in resources determines that the province's pillar industries are: agriculture, tobacco, mining, hydro-electric power, and tourism. In general, the province still depends on the natural resources. Secondary industry is currently the largest industrial tier in Yunnan, contributing more than 45 percent of GDP. Tertiary industry contributes 40 percent and agriculture 15 percent. Investment is the key driver of Yunnan's economic growth, especially in construction.  The main challenge that Yunnan faces is its lack of major development. Its low productivity and competitiveness restrict the rapid development of the province. The province also faces great challenges in social issues such as environmental protection, poverty elimination, illegal migration, drug trafficking and HIV/AIDS.  Yunnan's four pillar industries include tobacco, agriculture/biology, mining, and tourism. The main manufacturing industries are iron and steel production and copper-smelting, commercial vehicles, chemicals, fertilizers, textiles, and optical instruments. Yunnan has trade contacts with more than seventy countries and regions in the world. Yunnan established the Muse border trade zone (located in Ruili) along its border with Burma. Yunnan mainly exports tobacco, machinery and electrical equipment, chemical and agricultural products, and non-ferrous metals. In 2008, its total two-way trade (imports and exports) reached US$9.6 billion. The province signed foreign direct investment contracts involving US$1.69 billion, of which US$777 million were actually utilized during the year. Yunnan's unemployment rate at the end of 2008 was 4.21%.  Yunnan's nominal GDP in 2011 was 875.1 billion yuan (US$138.92 billion), an annual growth rate of 13.7%. Its per capita GDP was 13,494 yuan (US$1,975). The share of GDP of Yunnan's primary, secondary, and tertiary industries were 17.9%, 43%, and 39.1% respectively.  Yunnan is one of the major production bases of copper, lead, zinc, tin and aluminum in China. Gejiu is well known as "the Kingdom of Zinc" with the reserves ranked first in the country. The Yunxi brand refined tin is one of the main products in Gejiu, which is registered on the London Metal Exchange (LME). Besides, reserves of germanium, indium, zirconium, platinum, rock salt, sylvite, nickel, phosphate, mirabilite, arsenic and blue asbestos are also high. Significant copper deposits are found at Dongchuan, iron ore at Wuding, and coal at Xuanwei and Kaiyuan. Economic policy to locate new industry in interior areas with substantial mineral wealth, led to major industrial development in Yunnan, especially in the Kunming area.  The electricity industry is another important economic pillar of Yunnan, which plays a key role in the "West-East Electricity Transmission Project". The electricity produced in Yunnan is mainly transported to Guangdong.  First established in 1992, Kunming Economic & Technology Development Zone is a national-level zone approved by the State Council. Kunming is located in east-central Yunnan province with preferential location. After several years' development, the zone has formed its pillar industries, which include tobacco processing, machinery manufacturing, electronic information, and biotechnology.

Education.

Since the 1960s, improvements have been achieved in the overall educational level, which can be seen in the increase in average years of regular education received. The development of part-time schools have brought adult, distance and continuing education to farms, factories, offices, and other places. Evening, time off work / study leave classes allow people to receive education without leaving their jobs. Policies to upgrade adult education have begun to complement the campaign against illiteracy. A basic Chinese vocabulary in simplified strokes is taught to millions of illiterate people in short, intensive courses. Despite progress made, Yunnan's illiteracy rate remains one of the highest in

Health.

Yunnan Province is responsible for about 50% of officially reported malaria

Transport.

Railways.

The first railway in Yunnan was the narrow gauge Yunnan–Vietnam Railway built by France from 1904 to 1910 to connect Kunming with Vietnam, then a French colony. In Yunnan, the Chinese section of this railway is known as the Yunnan-Hekou Railway and the line gave Yunnan access to the seaport at Haiphong. During the Second World War, Britain and the United States began building a railway from Yunnan to Burma but abandoned the effort due to Japanese advance.  Due in part to difficult terrain both locally and in surrounding provinces and the shortage of capital for rail construction, Yunnan remained outside of China's domestic rail network until 1966 when the Guiyang–Kunming Railway was completed. The line would not enter into operation until 1970, the

Burma Road.

The Burma Road was a highway extending about through mountainous terrain from Lashio, northeast Burma northeastward to Kunming, China. Undertaken by the Chinese after the start of the Sino-Japanese War in 1937 and completed in 1938, it was a vital transportation route for wartime supplies to the Chinese government from Rangoon and shipped by railroad to Lashio from 1938 to 1946. An extension runs east through China from Kunming, then north to Chongqing. This

Highways.

Road construction in Yunnan continues unabated: over the last years the province has added more new roads than any other province. Today expressways link Kunming through Dali to Baoshan, Kunming to Mojiang (on the way to Jinghong), Kunming to Qujing, Kunming to Shilin (Stone Forest). The official plan is to connect all major towns and neighbouring capitals with expressways by 2010, and to complete a high-speed road network by 2020.  All county towns are now accessible by paved, all-weather roads from Kunming, all townships have a road connection (the last to be connected was Yangla, in the far north, but Dulongjiang remains cut off for about six months every year), and about half of all villages have road access.  Second-level national highways stretch, third-level highways, and fourth-level highways,. The province has formed a network of communication lines radiating from Kunming to Sichuan and Guizhou provinces and Guangxi and Tibet autonomous regions, and further on to Burma, Laos, Vietnam and Thailand.  National highways running through Yunnan province are:

Expressways.

After the opening of the Suolongsi to Pingyuanjie expressway, Luofu expressway, the first between Yunnan and Guangxi Province, opened in October 2007. It has made material and passenger transportation between the two provinces much more convenient. Moreover, Luofu Expressway has also become the main road from Yunnan to Guangxi and the coastal ports. Luofu Expressway begins from the crossroads of Luo Village between Yunnan and Guangxi Provinces and ends at Funing County of Wenshan State. The total length of the expressway is 79.3 kilometers which has shortened the commute between Yunnan and Guangxi from the previous 3 and half hours to just 50 minutes.  Expressways running through Yunnan province are:

Waterways.

Generally, rivers are obstacles to transport in Yunnan. Only very small parts of Yunnan's river systems are navigable. However, China is constructing a series of dams on the Mekong to develop it as a waterway and source of power; the first was completed at

Airports.

The province has twenty domestic air routes from Kunming to Beijing, Shanghai, Guangzhou, Chengdu, Haikou, Chongqing, Shenyang, Harbin, Wuhan, Xi'an, Lanzhou, Hangzhou, Xiamen, Nanning, Shenzhen, Guiyang, Changsha, Guilin, Lhasa and Hong Kong; eleven provincial air routes from

Bridges.

Bridge-building in Yunnan date back at least 1,300 years when the Tibetan Empire built an iron chain bridge over the Yangtze to the neighboring Nanzhao Kingdom at what is today Weixi Lisu Autonomous County during the Tang dynasty. Iron chain

Metro.

Kunming is the only city in Yunnan that has

Culture.

Yunnan's cultural life is one of remarkable diversity. Archaeological findings have unearthed sacred burial structures holding elegant bronzes in Jinning, south of Kunming. In northeastern Yunnan, frescoes of the Jin dynasty (265–420) have been discovered in the city of Zhatong. Many Chinese cultural relics have been discovered in later periods. The lineage of tribal way of life of the indigenous peoples persisted uninfluenced by modernity until the mid-20th century. Tribal traditions, such as Yi slaveholding and Wa headhunting, have since been abolished. After the Cultural Revolution (1966–76), in which several minority cultural and religious practices were suppressed, Yunnan has come to celebrate its cultural diversity and subsequently many local customs and festivals have flourished.

Tea.

Yunnan has several different tea growing regions. One of Yunnan's best known products is Pu-erh tea (or Puer),

Chinese medicine.

Yunnan is host to 15,000 species of plants,

Tourism.

Yunnan Province, due to its landscapes, mild climate and cultural diversity, is one of China's major tourist destinations. Most visitors are Chinese tourists, although trips to Yunnan are organized by an increasing number of foreign travel agencies as well. Mainland tourists travel by the masses; 2.75 million Chinese visited Yunnan last October during National Holiday. Also a different trend is slowly developing; small scale and environmentally friendly ecotourism. At the moment projects in this field are often being set up with help of NGO's.  In 2004, tourism revenues amounted to 37 billion RMB, and thus accounting for 12.6% of the provincial GDP. Another fact indicating the importance of tourism in Yunnan Province is capital Kunming hosting the China International Travel Mart every two years. This tourism trade fair is

Sport.

Professional sporting teams in Yunnan have included the now defunct Yunnan Bulls in the

Yunnan () is a province in the southwest of the People's Republic of China. The province spans approximately and has a population of 48.300 million (as of 2018). The capital of the province is Kunming, formerly also known as Yunnan. The province borders the Chinese provinces Guangxi, Guizhou, Sichuan, and the Tibet Autonomous Region, as well as the countries Vietnam, Laos, and Myanmar. Yunnan is China's fourth least developed province based on disposable income per capita in 2014.

Le Yunnan () est une province du sud-ouest de la Chine. Frontalier du Viêt Nam, du Laos et de la Birmanie, il regroupe des populations de diverses appartenances ethniques (25 minorités nationales). Région essentiellement montagneuse, le Yunnan reste une des provinces les moins riches de Chine, malgré le développement de la production de riz, cacao, café, thé, de la spiruline et du tourisme. Le PIB est passé de 400 milliards de yuans en 2006 à 1486 milliards de yuans en 2016.


Etymology.

The poet Hesiod presents a folk etymology of the name "Pegasus" as derived from "spring, well": "the "pegai" of Okeanos, where he was born."  A proposed etymology of the name is Luwian, meaning "lightning", and, a local Luwian-Hittite name in southern Cilicia of a weather god represented with thunder and lightning. The proponents of this etymology adduce Pegasus' role, reported as early as Hesiod, as the bringer of thunderbolts to Zeus. It was first suggested in 1952 and remains widely accepted, but Robin Lane Fox (2009) has criticized it as implausible.  Dr. Michael Brown, who has been studying ancient and medieval Greek poetry in the context of the Greek-North European dialogue, and has concluded from it that the word "Pegasus" is a pre-Celtic-PIE word, one which did not evolve into one of the numerous common names listed in both Greek and Western languages. This is discussed further in "Linguistics and Classical Theology," by William S. R. Miller, which is based on his work with Charles F. G. Osterhaus's analysis of the word and its relationships to Greek and Italian. The relationship of "Pegasus" to "Cyrillic" is discussed further in his Phrygian Monikers and the Naming of Greek Pronunciation "Cyrillic or Pene-Orthogyrin" and "Pegasus" as an Early Semitic construct.

Springs.

According to legend, everywhere the winged horse struck his hoof to the earth, an inspiring water spring burst forth. One of these springs was upon the Muses' Mount Helicon, the "Hippocrene" ("horse spring"), opened, Antoninus Liberalis suggested, at the behest of Poseidon to prevent the mountain swelling with rapture at the song of the Muses; another was at Troezen. Hesiod relates how Pegasus was peacefully drinking from a spring when the hero Bellerophon captured him. Hesiod also says Pegasus carried thunderbolts for Zeus.

Birth.

There are several versions of the birth of the winged stallion and his brother Chrysaor in the far distant place at the edge of Earth, Hesiod's "springs of Oceanus, which encircles the inhabited earth, where Perseus found Medusa:  One is that they sprang from the blood issuing from Medusa's neck as Perseus was beheading her, similar to the manner in which Athena was born from the head of Zeus. In another version, when Perseus beheaded Medusa, they were born of the Earth, fed by the Gorgon's blood. A variation of this story holds that they were formed from the mingling of Medusa's blood, pain and sea foam, implying that Poseidon had involvement in their making. The last version bears resemblance to Hesiod's account of the birth of Aphrodite from the foam created when Uranus's severed genitals were cast into the sea by Cronus.

Bellerophon.

Pegasus aided the hero Bellerophon in his fight against the Chimera. There are varying tales about how Bellerophon found Pegasus; the most common being that the hero was told by Polyeidos to sleep in the temple of Athena, where the goddess visited him in the night and presented him with a golden bridle. The next morning, still clutching the bridle, Bellerophon found Pegasus drinking at the Pierian spring, caught him and eventually tamed him.

Perseus.

Michaud's "Biographie universelle" relates that when Pegasus was born, he flew to where thunder and lightning are released. Then, according to certain versions of the myth, Athena tamed him and gave him to Perseus, who flew to Ethiopia to help Andromeda.

Olympus.

Pegasus and Athena left Bellerophon and continued to Olympus where he was stabled with Zeus' other steeds, and was given the task of carrying Zeus' thunderbolts, along with other members of his entourage, his attendants/handmaidens/shield bearers/shieldmaidens, Astrape and Bronte. Because of his years of faithful service to Zeus, Pegasus was later honoured with transformation into a constellation. On the day of his "catasterism", when Zeus transformed him into a constellation, a single feather fell to the earth near the city of Tarsus.

Legacy.

In heraldry.

The pegasus became a common element in British heraldry, appearing chiefly as a supporter or a crest. Pegasi may also appear upon escutcheons, although this is rare. A pegasus rampant is featured on the arms of the Inner Temple, while those of the Richardson family contain a rare depiction of a pegasus sejant.

World War II.

During World War II, the silhouetted image of Bellerophon the warrior, mounted on the winged Pegasus, was adopted by the United Kingdom's newly raised parachute troops in 1941 as their upper sleeve insignia. The image clearly symbolized a warrior arriving at a battle by air, the same tactics used by paratroopers. The square upper-sleeve insignia comprised Bellerophon/Pegasus in light blue on a maroon background. One source suggests that the insignia was designed by famous English novelist Daphne du Maurier, who was wife of the commander of the 1st Airborne Division (and later the expanded British Airborne Forces), General Frederick "Boy" Browning. According to the British Army Website, the insignia was designed by the celebrated East Anglian painter Major Edward Seago in May 1942. The maroon background on the insignia was later used again by the Airborne Forces when they adopted the famous maroon beret in Summer 1942. The beret was the origin of the German nickname for British airborne troops, the Red Devils. Today's Parachute Regiment carries on the maroon beret tradition. The selection process for the elite Parachute Regiment is called Pegasus Company (often abbreviated to "P Company"). In 2015 it was announced that the units of 16 Air Assault Brigade would once again use the Pegasus insignia after a 15-year hiatus.  During the airborne phase of the Normandy invasion on the night of 5–6 June 1944, British 6th Airborne Division captured all its key objectives in advance of the seaborne assault, including the capture and holding at all costs of a vital bridge over the Caen Canal, near Ouistreham. In memory of their tenacity, the bridge has been known ever since as Pegasus Bridge.  The Tuscan National Liberation Committee during the German occupation of Italy also had a Pegasus as its emblem. The winged horse is still featured on the Tuscan flag and coat of arms.

In popular culture.

The winged horse has provided an instantly recognizable corporate logo or emblem of inspiration. Ecuador launched its weather satellite, named "Pegaso" (, Pegasus in Spanish), on 26 April 2013 but it was damaged by Russian space debris. Pegasus Airlines (Turkish: Pegasus Hava Taşımacılığı A.Ş.) is a low-cost airline headquartered in the Kurtköy area of Pendik, Istanbul, Turkey. Mobil Oil has had a Pegasus as its company logo since its affiliation with Magnolia Petroleum Company in the 1930s.

Pegasus (, "Pḗgasos"; ) is a mythical winged divine horse, and one of the most recognized creatures in Greek mythology. Usually depicted as pure white, Pegasus is the offspring of the Olympian god Poseidon. He was foaled by the Gorgon Medusa upon her death, when the hero Perseus decapitated her. Pegasus is the brother of Chrysaor and the uncle of Geryon.

Pégase (en grec ancien / ', en latin ') est un cheval ailé divin, l'une des créatures fantastiques les plus célèbres de la mythologie grecque. Généralement blanc, ayant pour père Poséidon, Pégase naît avec son frère Chrysaor du sang de la Gorgone Méduse, lorsqu'elle est décapitée par le héros Persée. D'après les poètes gréco-romains, il monte au ciel après sa naissance et se met au service de Zeus, qui le charge d'apporter les éclairs et le tonnerre sur l’Olympe.


Signs and symptoms.

Iodine deficiency causes gradual enlargement of the thyroid gland, referred to as a goiter. Poor length growth is apparent as early as the first year of life. Adult stature without treatment ranges from, depending on severity, sex, and other genetic factors. Other signs include thickened skin, hair loss, enlarged tongue, and a protruding abdomen In children, bone maturation and puberty are severely delayed. In adults, ovulation is impeded and infertility is common.  Mental deterioration is common. Neurological impairment may be mild, with reduced muscle tone and coordination, or so severe that the person cannot stand or walk. Cognitive impairment may also range from mild to so severe that the person is nonverbal and dependent on others for basic care. Thought and reflexes are slower.

Cause.

Around the world, the most common cause of congenital hypothyroidism is dietary iodine deficiency. It has affected many people worldwide and continues to be a major public health problem in many countries.  Iodine is an essential trace element, necessary for the synthesis of thyroid hormones. Iodine deficiency is the most common preventable cause of neonatal and childhood brain damage worldwide. Although iodine is found in many foods, it is not universally present in all soils in adequate amounts. Most iodine, in iodide form, is in the oceans, where the iodide ions oxidize to elemental iodine, which then enters the atmosphere and falls to earth in rain, introducing iodine to soils. Soil deficient in iodine is most common inland, in mountainous areas, and in areas of frequent flooding. It can also occur in coastal regions, where iodine might have been removed from the soil by glaciation, as well as leaching by snow, water and heavy rainfall. Plants and animals grown in iodine deficient soils are correspondingly deficient. Populations living in those areas without outside food sources are most at risk of iodine deficiency diseases.

Differential diagnosis.

Dwarfism may also be caused by malnutrition or other hormonal deficiencies, such as insufficient growth hormone secretion, hypopituitarism, decreased secretion of growth hormone-releasing hormone, deficient growth hormone receptor activity and downstream causes, such as insulin-like growth factor 1 (IGF-1) deficiency.

Prevention.

There are public health campaigns in many countries which involve iodine administration. As of December 2019, 122 countries have mandatory iodine food fortification programs.

Treatment.

Congenital iodine deficiency has been almost completely eliminated in developed countries through iodine supplementation of food and by newborn screening utilizing a blood test for thyroid function.  Treatment consists of lifelong administration of thyroxine (T4). Thyroxine must be dosed as tablets only, even to newborns, as the liquid oral suspensions and compounded forms cannot be depended on for reliable dosing. For infants, the T4 tablets are generally crushed and mixed with breast milk, formula milk or water. If the medication is mixed with formulas containing iron or soya products, larger doses may be required, as these substances may alter the absorption of thyroid hormone from the gut. Monitoring TSH blood levels every 2–3 weeks during the first months of life is recommended to ensure that affected infants are at the high end of normal range.

History.

A goiter is the most specific clinical marker of either the direct or indirect insufficient intake of iodine in the human body. There is evidence of goiter, and its medical treatment with iodine-rich algae and burnt sponges, in Chinese, Egyptian, and Roman ancient medical texts. In 1848, King Carlo Alberto of Sardinia commissioned the first epidemiological study of congenital iodine deficiency syndrome, in northern Savoy where it was frequent. In past centuries, the well reported social diseases prevalent among the poorer social classes and farmers, caused by dietary and agricultural monocultures, were: pellagra, rickets, beriberi, scurvy in long-term sailors, and the endemic goiter caused by iodine deficiency. However, this disease was less mentioned in medical books because it was erroneously considered to be an aesthetic rather than a clinical disorder.  Congenital iodine deficiency syndrome was especially common in areas of southern Europe around the Alps and was often described by ancient Roman writers and depicted by artists. The earliest Alpine mountain climbers sometimes came upon whole villages affected by it. The prevalence of the condition was described from a medical perspective by several travellers and physicians in the late 18th and early 19th centuries. At that time the cause was not known and it was often attributed to "stagnant air" in mountain valleys or "bad water". The proportion of people affected varied markedly throughout southern Europe and even within very small areas it might be common in one valley and not another. The number of severely affected persons was always a minority, and most persons were only affected to the extent of having a goitre and some degree of reduced cognition and growth. The majority of such cases were still socially functional in their pastoral villages.  More mildly affected areas of Europe and North America in the 19th century were referred to as "goitre belts". The degree of iodine deficiency was milder and manifested primarily as thyroid enlargement rather than severe mental and physical impairment. In Switzerland, for example, where soil does not contain a large amount of iodine, cases of congenital iodine deficiency syndrome were very abundant and even considered genetically caused. As the variety of food sources dramatically increased in Europe and North America and the populations became less completely dependent on locally grown food, the prevalence of endemic goitre diminished.  The early 20th century saw the discovery of the relationships of neurological impairment with hypothyroidism due to iodine deficiency. Both have been largely eliminated in the developed world.

Terminology.

The term "cretin" was originally used to describe a person affected by this condition, but, as with words such as "spastic" and "lunatic", it underwent pejoration and is now considered derogatory and inappropriate. "Cretin" became a medical term in the 18th century, from an Occitan and an Alpine French expression, prevalent in a region where persons with such a condition were especially common (see below); it saw wide medical use in the 19th and early 20th centuries, and was a "tick box" category on Victorian-era census forms in the UK. The term spread more widely in popular English as a markedly derogatory term for a person who behaves stupidly. Because of its pejorative connotations in popular speech, health-care workers have mostly abandoned the term "cretin".  The etymology of "cretin" is uncertain. Several hypotheses exist. The most common derivation provided in English dictionaries is from the Alpine French dialect pronunciation of the word "Chrétien" ("(a) Christian"), which was a greeting there. According to the "Oxford English Dictionary", the translation of the French term into "human creature" implies that the label "Christian" is a reminder of the humanity of the afflicted, in contrast to brute beasts. Other sources suggest that "Christian" describes the person's "Christ-like" inability to sin, stemming, in such cases, from an incapacity to distinguish right from wrong.  Other speculative etymologies have been offered:

Congenital iodine deficiency syndrome is a medical condition present at birth marked by impaired physical and mental development, due to insufficient thyroid hormone (hypothyroidism) often caused by insufficient dietary iodine during pregnancy. It is one cause of underactive thyroid function at birth, called congenital hypothyroidism, and also referred to as "cretinism".

Le crétinisme est un ensemble de troubles physiques et de retard mental provoqué par une grave insuffisance thyroïdienne, non traitée.


History.

Henry Heimlich, noted for promulgating abdominal thrusts, claimed that back slaps were proven to cause death by lodging foreign objects into the windpipe. The 1982 Yale study by Day, DuBois, and Crelin that persuaded the American Heart Association to stop recommending back blows for dealing with choking was partially funded by Heimlich's own foundation. According to Roger White MD of the Mayo Clinic and American Heart Association (AHA), "There was never any science here. Heimlich overpowered science all along the way with his slick tactics and intimidation, and everyone, including us at the AHA, caved in."  From 1985 to 2005, abdominal thrusts were the only recommended treatment for choking in the published guidelines of the American Heart Association and the American Red Cross. In 2006, both organizations drastically changed course and "downgraded" the use of the technique. For conscious victims, the new guidelines recommend first applying back slaps; if this method failed to remove the airway obstruction, rescuers were to then apply abdominal thrusts. For unconscious victims, the new guidelines recommend chest thrusts.  Henry Heimlich also promoted abdominal thrusts as a treatment for drowning and asthma attacks. The Red Cross now contests those claims. The Heimlich Institute has stopped advocating on their website for the Heimlich maneuver to be used as a first aid measure for drowning victims. His son, Peter M. Heimlich, alleges that in August 1974 his father published the first of a series of fraudulent case reports in order to promote the use of abdominal thrusts for near-drowning rescue. The 2005 drowning rescue guidelines of the American Heart Association did not include citations of Heimlich's work, and warned against the use of the Heimlich maneuver for drowning rescue as unproven and dangerous, due to its risk of vomiting leading to aspiration.  In May 2016 Henry Heimlich, age 96, personally used the maneuver to save the life of a fellow resident at his retirement home in Cincinnati. According to the article, it was either the first or second time Heimlich himself used his namesake maneuver to save the life of someone in a non-simulated choking situation.

Universal sign of choking.

A choking victim is usually unable to speak, and may not be able to make much sound at all. A universal sign of choking has been designated as a silent indication from a person who is unable to breathe, and consists of placing both hands on one's own throat while trying to attract the attention of others who might assist.

Technique.

Both the American Red Cross and UK National Health Service (NHS) advise that, as a first resort, a rescuer should encourage the patient to cough out the obstruction. As a second resort, the rescuer should give five slaps on the back, after bending the patient forward. Abdominal thrusts are recommended only if these methods fail. As with the European Resuscitation Council and the Mayo Clinic, they recommend a repeating cycle of 5 back slaps and 5 abdominal thrusts. They are not recommended on babies below the age of 1. In contrast to the prevailing American and European advice, the Australian Resuscitation Council recommends chest thrusts instead of abdominal thrusts.  Performing abdominal thrusts involves a rescuer standing behind an upright patient, and using his or her hands to exert forceful pressures on the bottom of the diaphragm. As an example, WebMD recommends to make a fist with one hand grasping it with the other, to press with both just above the person's bellybutton. This compresses the lungs and exerts pressure on any object lodged in the trachea, hopefully expelling it. The pressure amounts to an artificially induced cough. To assist a larger person, more force may be needed. The Mayo Clinic recommends the same placement of fist and hand and upward thrusts as if you are trying to lift the person.  If the victim can not receive pressures on the abdomen (for example, in case of pregnancy or excessive obesity), chest thrust are advised instead. These are applied on the lower half of the chest bone, but not in the very endpoint (which is the xiphoid process and could be broken).  If the victim is not upright, the US National Institutes of Health (NIH) recommends positioning the person on his or her back, then straddling the torso and using chest thrusts.  It is possible for still-conscious choking victims to perform the procedure on themselves, without assistance. However, this can be difficult, so, in this cases and some others (disabled people, etc.), it's recommended the use of an anti-choking device.  Due to the forceful nature of the procedure, even when done correctly, abdominal thrusts can injure the person on whom it is performed. Bruising to the abdomen is highly likely and more serious injuries can occur, including fracture of the xiphoid process or ribs. The NHS recommend that anyone who has been subjected to abdominal thrusts should seek a medical examination afterwards.  Researchers at Royal Brompton Hospital have demonstrated that similar intrathoracic pressures (50–60 cmHO) are produced by a first aider performing abdominal thrusts "inwards" as are produced when the force is directed "inwards and upwards". They argue that this may be easier to perform with less concern about injury to ribcage or upper abdominal organs. Self-administered abdominal thrusts by study participants produced similar pressures to those generated by first aiders. The highest pressures were produced by participants performing an abdominal thrust onto the back of a chair (115 cmHO).

The Abdominal thrusts (also called the Heimlich maneuver, or Heimlich manoeuvre) is a first aid procedure used to treat upper airway obstructions (or choking) by foreign objects. American doctor Henry Heimlich is often credited for its discovery. Performing abdominal thrusts involves a rescuer standing behind a patient and using his or her hands to exert pressure on the bottom of the diaphragm. This compresses the lungs and exerts pressure on any object lodged in the trachea, hopefully expelling it.

La méthode ou manœuvre de Heimlich est un geste de premiers secours permettant la libération des voies aériennes chez l'adulte et l'enfant de plus d'un an. Elle a été décrite pour la première fois par Henry J. Heimlich en 1974 et sert en cas d'obstruction totale des voies aériennes par un corps étranger.