title: Koala content: 1934 and was "intensely interested in the bears". His photograph, with Noel Burnet, the founder of the park, and a koala, appeared in "The Sydney Morning Herald". After World War II, when tourism to Australia increased and the animals were exported to zoos overseas, the koala's international popularity rose. Several political leaders and members of royal families had their pictures taken with koalas, including Queen Elizabeth II, Prince Harry, Crown Prince Naruhito, Crown Princess Masako, Pope John Paul II, US President Bill Clinton, Soviet premier Mikhail Gorbachev, South African President Nelson Mandela, Prime Minister Tony Abbott, and Russian President Vladimir


title: Koala content: Putin. The koala is well known worldwide and is a major draw for Australian zoos and wildlife parks. It has been featured in advertisements, games, cartoons, and as soft toys. It benefited the national tourism industry by over an estimated billion Australian dollars in 1998, a figure that has since grown. In 1997, half of visitors to Australia, especially those from Korea, Japan, and Taiwan, sought out zoos and wildlife parks; about 75% of European and Japanese tourists placed the koala at the top of their list of animals to see. According to biologist Stephen Jackson: "If you were to


title: Koala content: take a straw poll of the animal most closely associated with Australia, it's a fair bet that the koala would come out marginally in front of the kangaroo". Factors that contribute to the koala's enduring popularity include its child-like body proportions and teddy bear-like face. The koala is featured in the Dreamtime stories and mythology of indigenous Australians. The Tharawal people believed that the animal helped row the boat that brought them to the continent. Another myth tells of how a tribe killed a koala and used its long intestines to create a bridge for people from other parts of


title: Koala content: the world. This narrative highlights the koala's status as a game animal and the length of its intestines. Several stories tell of how the koala lost its tail. In one, a kangaroo cuts it off to punish the koala for being lazy and greedy. Tribes in both Queensland and Victoria regarded the koala as a wise animal and sought its advice. Bidjara-speaking people credited the koala for turning barren lands into lush forests. The animal is also depicted in rock carvings, though not as much as some other species. Early European settlers in Australia considered the koala to be a


title: Koala content: prowling sloth-like animal with a "fierce and menacing look". At the beginning of the 20th century, the koala's reputation took a more positive turn, largely due to its growing popularity and depiction in several widely circulated children's stories. It is featured in Ethel Pedley's 1899 book "Dot and the Kangaroo", in which it is portrayed as the "funny native bear". Artist Norman Lindsay depicted a more anthropomorphic koala in "The Bulletin" cartoons, starting in 1904. This character also appeared as Bunyip Bluegum in Lindsay's 1918 book "The Magic Pudding". Perhaps the most famous fictional koala is Blinky Bill. Created by


title: Koala content: Dorothy Wall in 1933, the character appeared in several books and has been the subject of films, TV series, merchandise, and a 1986 environmental song by John Williamson. The first Australian stamp featuring a koala was issued by the Commonwealth in 1930. A television ad campaign for Australia's national airline Qantas, starting in 1967 and running for several decades, featured a live koala (voiced by Howard Morris), who complained that too many tourists were coming to Australia and concluded "I hate Qantas". The series has been ranked among the greatest commercials of all time. The song "Ode to a Koala


title: Koala content: Bear" appears on the B-side of the 1983 Paul McCartney/Michael Jackson duet single "Say Say Say". A koala is the main character in Hanna-Barbera's "The Kwicky Koala Show" and Nippon Animation's "Noozles", both of which were animated cartoons of the early 1980s. Food products shaped like the koala include the Caramello Koala chocolate bar and the bite-sized cookie snack Koala's March. Dadswells Bridge in Victoria features a tourist complex shaped like a giant koala, and the Queensland Reds rugby team has a koala as its mascot. The Platinum Koala coin features the animal on the reverse and Elizabeth II on


title: Koala content: the obverse. The drop bear is an imaginary creature in contemporary Australian folklore featuring a predatory, carnivorous version of the koala. This hoax animal is commonly spoken about in tall tales designed to scare tourists. While koalas are typically docile herbivores, drop bears are described as unusually large and vicious marsupials that inhabit treetops and attack unsuspecting people (or other prey) that walk beneath them by dropping onto their heads from above. While the koala was previously classified as Least Concern on the Red List, it was uplisted to Vulnerable in 2016. Australian policy makers declined a 2009 proposal to


title: Koala content: include the koala in the Environment Protection and Biodiversity Conservation Act 1999. In 2012, the Australian government listed koala populations in Queensland and New South Wales as Vulnerable, because of a 40% population decline in the former and a 33% decline in the latter. Populations in Victoria and South Australia appear to be abundant; however, the Australian Koala Foundation argues that the exclusion of Victorian populations from protective measures is based on a misconception that the total koala population is 200,000, whereas they believe it is probably less than 100,000. Koalas were hunted for food by Aboriginals. A common technique


title: Koala content: used to capture the animals was to attach a loop of ropey bark to the end of a long, thin pole, so as to form a noose. This would be used to snare an animal high in a tree, beyond the reach of a climbing hunter; an animal brought down this way would then be killed with a stone hand axe or hunting stick (waddy). According to the customs of some tribes, it was considered taboo to skin the animal, while other tribes thought the animal's head had a special status, and saved them for burial. The koala was heavily


title: Koala content: hunted by European settlers in the early 20th century, largely for its thick, soft fur. More than two million pelts are estimated to have left Australia by 1924. Pelts were in demand for use in rugs, coat linings, muffs, and as trimming on women's garments. Extensive cullings occurred in Queensland in 1915, 1917, and again in 1919, when over one million koalas were killed with guns, poisons, and nooses. The public outcry over these cullings was probably the first wide-scale environmental issue that rallied Australians. Novelist and social critic Vance Palmer, writing in a letter to "The Courier-Mail", expressed the


title: Koala content: popular sentiment: "The shooting of our harmless and lovable native bear is nothing less than barbarous ... No one has ever accused him of spoiling the farmer's wheat, eating the squatter's grass, or even the spreading of the prickly pear. There is no social vice that can be put down to his account ... He affords no sport to the gun-man ... And he has been almost blotted out already from some areas." Despite the growing movement to protect native species, the poverty brought about by the drought of 1926–28 led to the killing of another 600,000 koalas during a


title: Koala content: one-month open season in August 1927. In 1934, Frederick Lewis, the Chief Inspector of Game in Victoria, said that the once-abundant animal had been brought to near extinction in that state, suggesting that only 500–1000 remained. The first successful efforts at conserving the species were initiated by the establishment of Brisbane's Lone Pine Koala Sanctuary and Sydney's Koala Park Sanctuary in the 1920s and 1930s. The owner of the latter park, Noel Burnet, became the first to successfully breed koalas and earned a reputation as the foremost contemporary authority on the marsupial. In 1934, David Fleay, curator of Australian mammals


title: Koala content: at the Melbourne Zoo, established the first Australian faunal enclosure at an Australian zoo, and featured the koala. This arrangement allowed him to undertake a detailed study of its diet in captivity. Fleay later continued his conservation efforts at Healesville Sanctuary and the David Fleay Wildlife Park. Since 1870, koalas have been introduced to several coastal and offshore islands, including Kangaroo Island and French Island. Their numbers have significantly increased, and since the islands are not large enough to sustain such high koala numbers, overbrowsing has become a problem. In the 1920s, Lewis initiated a program of large-scale relocation and


title: Koala content: rehabilitation programs to transfer koalas whose habitat had become fragmented or reduced to new regions, with the intent of eventually returning them to their former range. For example, in 1930–31, 165 koalas were translocated to Quail Island. After a period of population growth, and subsequent overbrowsing of gum trees on the island, about 1,300 animals were released into mainland areas in 1944. The practice of translocating koalas became commonplace; Victorian State manager Peter Menkorst estimated that from 1923 to 2006, about 25,000 animals were translocated to more than 250 release sites across Victoria. Since the 1990s, government agencies have tried


title: Koala content: to control their numbers by culling, but public and international outcry has forced the use of translocation and sterilisation, instead. One of the biggest anthropogenic threats to the koala is habitat destruction and fragmentation. In coastal areas, the main cause of this is urbanisation, while in rural areas, habitat is cleared for agriculture. Native forest trees are also taken down to be made into wood products. In 2000, Australia ranked fifth in the world by deforestation rates, having cleared . The distribution of the koala has shrunk by more than 50% since European arrival, largely due to fragmentation of habitat


title: Koala content: in Queensland. The koala's "vulnerable" status in Queensland and New South Wales means that developers in these states must consider the impacts on this species when making building applications. In addition, koalas live in many protected areas. While urbanisation can pose a threat to koala populations, the animals can survive in urban areas provided enough trees are present. Urban populations have distinct vulnerabilities: collisions with vehicles and attacks by domestic dogs kill about 4,000 animals every year. Injured koalas are often taken to wildlife hospitals and rehabilitation centres. In a 30-year retrospective study performed at a New South Wales koala


title: Koala content: rehabilitation centre, trauma (usually resulting from a motor vehicle accident or dog attack) was found to be the most frequent cause of admission, followed by symptoms of "Chlamydia" infection. Wildlife caretakers are issued special permits, but must release the animals back into the wild when they are either well enough or, in the case of joeys, old enough. As with most native animals, the koala cannot legally be kept as a pet in Australia or anywhere else. Koala The koala ("Phascolarctos cinereus", or, inaccurately, koala bear) is an arboreal herbivorous marsupial native to Australia. It is the only extant representative


title: Knife content: Hunters use a hunting knife, soldiers use the combat knife, scouts, campers, and hikers carry a pocket knife; there are kitchen knives for preparing foods (the chef's knife, the paring knife, bread knife, cleaver), table knives (butter knives and steak knives), weapons (daggers or switchblades), knives for throwing or juggling, and knives for religious ceremony or display (the kirpan). A modern knife consists of: The blade edge can be plain or serrated, or a combination of both. Single-edged knives may have a "reverse edge" or "false edge" occupying a section of the spine. These edges are usually serrated and are


title: "King Kong (1933 film)" content: board was wary about the project, but gave its approval after Cooper organized a presentation with Wray, Armstrong, and Cabot, and O'Brien's model dinosaurs. In his executive capacity, Cooper ordered the "Creation" production shelved, and put its crew to work on "Kong". Cooper assigned recently hired RKO screenwriter and best-selling British mystery/adventure writer Edgar Wallace the job of writing a screenplay and a novel based on his gorilla fantasy. Cooper understood the commercial appeal of Wallace's name and planned to publicize the film as being "based on the novel by Edgar Wallace". Wallace conferred with Cooper and O'Brien (who contributed,


title: "King Kong (1933 film)" content: Legendary Pictures and Warner Bros. released a Kong reboot film titled "" in 2017 which was directed by Jordan Vogt-Roberts and is the second installment of a shared universe called the MonsterVerse, which started with Legendary's reboot of " Godzilla". King Kong (1933 film) King Kong is a 1933 American pre-Code monster adventure film directed and produced by Merian C. Cooper and Ernest B. Schoedsack. The screenplay by James Ashmore Creelman and Ruth Rose was developed from an idea conceived by Cooper and Edgar Wallace. It stars Fay Wray, Bruce Cabot and Robert Armstrong, and opened in New York City


title: Kenning content: or important man will be characterised as generous, according to one common convention, and called an "enemy of gold", "attacker of treasure", "destroyer of arm-rings", etc. and a friend of his people. Nevertheless, there are many instances of ambiguity in the corpus, some of which may be intentional, and some evidence that, rather than merely accepting it from expediency, skalds favoured contorted word order for its own sake. Some scholars take the term kenning broadly to include any noun-substitute consisting of two or more elements, including merely descriptive epithets (such as Old Norse "grand viðar" "bane of wood" = "fire"


title: Kenning content: "gleam-harmers of the land of rings" = "harmers of gleam of arm" = "harmers of ring" = "leaders, nobles, men of social standing (conceived of as generously destroying gold, i.e. giving it away freely)" (Anon.: Líknarbraut 42). While some Old Norse kennings are relatively transparent, many depend on a knowledge of specific myths or legends. Thus the sky might be called naturalistically "él-ker" "squall-vat" (Markús Skeggjason: Eiríksdrápa 3) or described in mythical terms as "Ymis haus" "Ymir's skull" (Arnórr jarlaskáld: Magnúsdrápa 19), referring to the idea that the sky was made out of the skull of the primeval giant Ymir.


title: "Korean cuisine" content: meat. "Hwangu" has been considered better for consumption than "Baekgu" (White dog) and "Heukgu" (Black dog). Around 1816, "Jeong Hak-yu", the second son of "Jeong Yak-yong", a prominent politician and scholar of the Joseon dynasty, wrote a poem called "Nongga Wollyeongga" (농가월령가). This poem, which is an important source of Korean folk history, describes what ordinary Korean farming families did in each month of the year. In the description of the month of August the poem tells of a married woman visiting her birth parents with boiled dog meat, rice cake, and rice wine, thus showing the popularity of dog


title: Keeshond content: Keeshond The Keeshond ( ) is a medium-sized dog with a plush, two-layer coat of silver and black fur with a ruff and a curled tail. It originated in Holland, and its closest relatives are the German spitzes such as the Großspitz, Mittelspitz, and Kleinspitz or Pomeranian. The Keeshond was previously known as the Dutch Barge Dog, as it was frequently seen on the barges traveling the canals and rivers of Holland. The Keeshond was the symbol of the Patriot faction in Holland during political unrest in the years immediately preceding the French Revolution. In the late 19th century the


title: Keeshond content: breed was developed in England from imports obtained in both Holland and Germany. In 1930 the Keeshond was first registered with The American Kennel Club. A member of the spitz group of dogs, the Keeshond in American Kennel Club (AKC) standard is to tall and ± in the Fédération Cynologique Internationale (FCI) standard and weighs to . Sturdily built, they have a typical spitz appearance, neither coarse nor refined. They have a wedge-shaped head, a medium-length muzzle with a definite stop, small pointed ears, and an expressive face. The tail is tightly curled and, in profile, should be carried such


title: Keeshond content: that it is indistinguishable from the compact body of the dog. Like all spitz-type dogs, the Keeshond has a dense double coat, with a thick ruff around the neck. Typically, the males of this breed will have a thicker, more pronounced ruff than the females. The body should be abundantly covered with long, straight, harsh hair standing well out from a thick, downy undercoat. The hair on the legs should be smooth and short, except for a feathering on the front legs and "trousers", as previously described, on the hind legs. The hair on the tail should be profuse, forming


title: Keeshond content: a rich plume. Head, including muzzle, skull, and ears, should be covered with smooth, soft, short hair—velvety in texture on the ears. Coat must not part down the back. Coat care requires line brushing on a fairly regular basis. The Keeshond typically 'blows' its undercoat once a year for males, twice a year for females. During this time, the loss of coat is excessive and their guard hairs will lie flat to their back. It usually takes 2 weeks for the 'blow' to complete, in order for new undercoat to begin growing back in. A Keeshond should never be shaved,


title: Keeshond content: as their undercoat provides a natural barrier against heat and cold. Keeping their coat in good condition will allow efficient insulation in both hot and cold weather. The color should be a mixture of grey and black and some white as well. The undercoat should be very pale grey or cream (not tawny). The hair of the outer coat is black tipped, the length of the black tips producing the characteristic shading of color. The color may vary from light to dark, but any pronounced deviation from the grey color is not permissible. The plume of the tail should be


title: Keeshond content: very light grey when curled on back and the tip of the tail should be black. Legs and feet should be cream. Ears should be very dark - almost black. Shoulder line markings (light grey) should be well defined. The color of the ruff and "trousers" is generally lighter than that of the body. "Spectacles" and shadings, as later described, are characteristic of the breed and must be present to some degree. There should be no pronounced white markings. According to the American Kennel Club breed standard, the legs and feet are to be cream; feet that are totally black


title: Keeshond content: or white are severe faults. Black markings more than halfway down the foreleg, except for pencilling, are faulted. The other important marking is the "spectacles," a delicate dark line running from the outer corner of each eye toward the lower corner of each ear, which, coupled with markings forming short eyebrows, is necessary for the distinct expressive look of the breed. All markings should be clear, not muddled or broken. Absence of the spectacles is considered a serious fault. The eyes should be dark brown, almond-shaped with black eye rims. Ears should be small, dark, triangular, and erect. Keeshonden tend


title: Keeshond content: to be very playful, with quick reflexes and strong jumping ability. They are thoughtful, eager to please and very quick learners, which means they are also quick to learn things their humans did not intend to teach them. However, Keeshonden make excellent agility and obedience dogs. In fact, so amenable to proper training is this bright, sturdy dog that they have been successfully trained to serve as guide dogs for the blind; only their lack of size has prevented them from being more widely used in this role. They love children and are excellent family dogs, preferring to be close


title: Keeshond content: to their humans whenever possible. They generally get along with other dogs as well and will enjoy a good chase around the yard. Keeshonden are very intuitive and empathetic and are often used as comfort dogs. Most notably, at least one Keeshond, Tikva, was at Ground Zero on 9/11 to help comfort the rescue workers. The breed has a tendency to become especially clingy towards their owners, more so than most other breeds. If their owner is out, or in another room behind a closed door, they may sit, waiting for their owner to reappear, even if there are other


title: Keeshond content: people nearby. Many have been referred to as their "owner's shadow," or "velcro dogs". They are known by their loud, distinctive bark. Throughout the centuries, the Keeshond has been very popular as a watch dog on barges on canals in the Netherlands and middle Europe. This trait is evident to this day, and they are alert dogs that warn their owners of any new visitors. Although loud and alert, Keeshonden are not aggressive towards visitors. They generally welcome visitors affectionately once their family has accepted them. Unfortunately, barking may become a problem if not properly handled. Keeshonden that are kept


title: Keeshond content: in a yard, and not allowed to be with their humans, are unhappy and often become nuisance barkers. The Keeshond is very bright in work and obedience. The Keeshond ranks 16th in Stanley Coren's "The Intelligence of Dogs", being of excellent working/obedience intelligence. This intelligence makes a Keeshond a good choice for the dog owner who is willing to help a dog learn the right lessons, but also entails added responsibility. While affectionate, Keeshonden are not easy for the inexperienced trainer. Consistency and fairness are needed; and, while most dogs need a structured environment, it is especially necessary with a


title: Keeshond content: Keeshond. Like most of the independent-minded spitz breeds, Keeshonden respond poorly to heavy-handed or forceful training methods. Many behavioral problems with Keeshonden stem from these intelligent dogs inventing their own activities (often destructive ones, like digging and chewing) out of boredom. They need daily contact with their owners and lots of activity to remain happy. The Keeshonden does not live happily alone in a kennel or backyard. Keeshonden can also be timid dogs. It is important to train them to respect, but not fear, their owners and family. Keeshonden want to please, so harsh punishment is not necessary when the


title: Keeshond content: dog does not obey as quickly as desired. They like to spend time with their owners and love attention. Keeshonden are generally a very healthy breed. Though congenital health issues are not common, the conditions which have been known to sometimes occur in Keeshonden are hip dysplasia, luxating patellas (trick knee), epilepsy, Cushing's disease, diabetes, primary hyperparathyroidism, and hypothyroidism. Von Willebrand's disease has been known in Keeshonden but is very rare. An accurate test for the gene causing primary hyperparathyroidism (or PHPT) has recently been developed at Cornell University. As with any breed, it is important when buying a puppy


title: Keeshond content: to make sure that both parents have been tested and certified free from inherited problems. Test results may be obtained from the breeder, and directly from the Orthopaedic Foundation For Animals site. Keeshonds in a UK Kennel Club survey had a median lifespan of 12 years 2 months. 1 in 4 died of old age, at an average of 14–15 years. Because of their double coat, Keeshonden need regular brushing; an hour a week will keep the dog comfortable and handsome. The Keeshond's coat sheds dirt when dry, and the breed is not prone to doggy odor, so frequent bathing


title: Keeshond content: is unnecessary and undesirable. The coat acts as insulation and protects the dog from sunburn and insects, so shaving is not desirable, however some owners find it beneficial to clip their dogs coats in hotter weather. The coat also loses its distinct color as the black tipping on the hairs will be shorn off. If frequent brushing is too much effort, it is better to choose another breed rather than clip the Keeshond short. The Keeshond was named after the 18th-century Dutch Patriot, Cornelis (Kees) de Gyselaer (spelled 'Gijzelaar' in Modern Dutch), leader of the rebellion against the House of


title: Keeshond content: Orange. The dog became the rebels' symbol; and, when the House of Orange returned to power, this breed almost disappeared. The word 'keeshond' is a compound word: 'Kees' is a nickname for Cornelius (de Gyselaer), and 'hond' is the Dutch word for dog. In the Netherlands, "keeshond" is the term for German Spitzes that encompass them all from the toy or dwarf (Pomeranian) to the Wolfspitz (Keeshond). The sole difference among the German Spitzes is their coloring and size guidelines. Although many American references point to the Keeshond as we know it originating in the Netherlands, the breed is cited


title: Keeshond content: as being part of the German Spitz family, originating in Germany along with the Pomeranian (toy or dwarf German Spitz) and American Eskimo dog (small or standard German Spitz) according to the FCI. The first standard for "Wolfspitz" was posted at the Dog Show of 1880 in Berlin. The Club for German Spitzes was founded in 1899. The German standard was revised in 1901 to specify the characteristic color that we know today, "silver grey tipped with black". In the late 19th century the "Overweight Pomeranian", a white German Spitz and most likely a Standard German Spitz, was shown in


title: Keeshond content: the British Kennel Club. The "Overweight Pomeranian" was no longer recognized by the British Kennel Club in 1915. In the 1920s, Baroness van Hardenbroeck took an interest in the breed and began to build it up again. The Nederlandse Keeshond Club was formed in 1924. The Dutch Barge Dog Club of England was formed in 1925 by Mrs. Wingfield-Digby and accepted into the British Kennel Club in 1926, when the breed and the club were renamed to Keeshond. Carl Hinderer is credited with bringing his Schloss Adelsburg Kennel, which he founded in 1922 in Germany, with him to America in


title: Keeshond content: 1923. His German Champion Wolfspitz followed him two by two in 1926. At that time, less than ten years after World War I, Germany was not regarded fondly in England and America; and the Wolfspitz/Keeshond was not recognized by the AKC. Consequently, Carl had to register each puppy with his club in Germany. Despite this, Carl joined the Maryland KC and attended local shows. Carl regularly wrote to the AKC, including the New York headquarters, to promote the Wolfspitz. While going through New York on his way to Germany in 1930, Carl visited the AKC offices and presented Wachter, his


title: Keeshond content: Germany champion, to AKC President, Dr. DeMond, who promptly agreed to start the recognition process, with some caveats including changing the name to Keeshond, and asked Carl to bring back all the relevant data from Germany. Carl also translated the German standard to English for the AKC. The Keeshond was accepted for AKC registration in 1930. Despite intense lobbying the FCI would not accept the Keeshond as a separate breed since it viewed the Wolfspitz and Keeshond as identical. In 1997, the German Spitz Club updated its standard so that the typically smaller Keeshond preferred in America and other English-speaking


title: Keeshond content: countries could be included. This greatly expanded the gene pool and unified the standard internationally for the first time. Now bred for many generations as a companion dog, the Keeshond easily becomes a loving family member. As a result of the breed's history and friendly disposition, Keeshonden are sometimes referred to as "The Smiling Dutchman". Historically, Keeshonden being part of the German Spitz family had been interbred with their smaller brethren (small, standard, and dwarf German spitzes) and came in several colors—white, black, red, orange, orange-shaded white (also called orange and cream), and silver gray. Originally, like the other German


title: Keeshond content: spitzes, many colors, including piebalds, were allowed, but as time progressed, only the silver-grey and cream (wolf-gray) color was finally established into the Wolfspitz type. While other-colored Keeshonden can have terrific conformation, they are not allowed to be shown in the show ring. Colored Keeshonden are considered "pet quality". The appearance of oddly-colored Kees in otherwise wolf-gray litters has caused research into the early history of Keeshond coat colors. Because of this, some breeders wonder whether the Keeshond should be bred for colors other than grey. There are many bloodlines carrying the colored gene, and rather than examples of mixed


title: Keeshond content: breeding, colors are legitimate throwbacks to an earlier era of the breed. No one knows the exact number of colored Keeshonden born in the United States. Incorrect or incomplete documentation make it impossible to determine how many colored Keeshonden, and of which colors, have been born in the United States. Keeshond The Keeshond ( ) is a medium-sized dog with a plush, two-layer coat of silver and black fur with a ruff and a curled tail. It originated in Holland, and its closest relatives are the German spitzes such as the Großspitz, Mittelspitz, and Kleinspitz or Pomeranian. The Keeshond was


title: "Kremlin (fortification)" content: Kremlin (fortification) A kremlin (, "castle", or "citadel") is a major fortified central complex found in historic Russian cities. This word is often used to refer to the most famous, the Moscow Kremlin, or metonymically to the government that is based there. The word is probably of Slavic-Tartar origin, and may share the same root as "kremen" ( , "flint"). After the disintegrations of the Kievan Rus, the Russian Empire and the USSR, some fortresses considered Kremlin-type, remained beyond the borders of modern Russia. Some are listed below: The same structure in Ukraine is called dytynets (, from "dytyna" –


title: "Kremlin (fortification)" content: child). The term has been in use since the 11th century. The term "kremlin" first appeared in 14th century in Russian territories, where it replaced "dytynets". Many Russian monasteries have been built in a fortress-like style similar to that of a kremlin. For a partial list, see . Kremlin (fortification) A kremlin (, "castle", or "citadel") is a major fortified central complex found in historic Russian cities. This word is often used to refer to the most famous, the Moscow Kremlin, or metonymically to the government that is based there. The word is probably of Slavic-Tartar origin, and may share


title: "Khunjerab Pass" content: Khunjerab Pass Khunjerab Pass (; ) (elevation ) is a high mountain pass in the Karakoram Mountains in a strategic position on the northern border of Pakistan (Region of Gilgit–Baltistan’s Hunza and Nagar Districts) and on the southwest border of China (the Xinjiang region) Its name is derived from two words of the local Wakhi language : 'Khun' means Blood and 'Jerav' means a creek coming from spring water/water falling. The Khunjerab Pass is the highest paved international border crossing in the world and the highest point on the Karakoram Highway. The roadway across the pass was completed in 1982,


title: "Khunjerab Pass" content: and has superseded the unpaved Mintaka and Kilik Passes as the primary passage across the Karakoram Range. The choice of Khunjerab Pass for Karakoram Highway was decided in 1966: China citing the fact that Mintaka would be more susceptible to air strikes recommended the steeper Khunjerab Pass instead. On the Pakistani - administered side, the pass is from the National Park station and checkpoint in Dih, from the customs and immigration post in Sost, from Gilgit, and from Islamabad. On the Chinese side, the pass is the southwest terminus of China National Highway 314 (G314) and is from Tashkurgan, from


title: "Khunjerab Pass" content: Kashgar and some from Urumqi. The Chinese port of entry is located along the road from the pass in Tashkurgan County. The long, relatively flat pass is often snow-covered during the winter season and as a consequence is generally closed for heavy vehicles from November 30 to May 1 and for all vehicles from December 30 to April 1. The reconstructed Karakoram Highway passes thru Khunjerab Pass. Since June 1, 2006, there has been a daily bus service across the boundary from Gilgit, to Kashgar, Xinjiang This is one of the international borders where left-hand traffic (Pakistan - administered Gilgit-Baltistan)


title: "Khunjerab Pass" content: changes to right-hand traffic (China) and vice versa. It has the highest ATM in the world on Pakistani side from the National Bank of Pakistan and 1LINK. In 2007, consultants were engaged to investigate the construction of a railway through this pass to connect China with transport in Pakistani-administered Gilgit-Baltistan. A feasibility study started in November 2009 for a line connecting Havelian away in Pakistan and Kashgar in Xinjiang.. However no progress has been made thereafter and this project is also not part of the current CPEC plan. Khunjerab Pass Khunjerab Pass (; ) (elevation ) is a high mountain


title: Logrolling content: Tullock 1962). Table 1-1 explains another example of logrolling. In the example, we have three individuals: Tanya, Alvin, and Rebecca. Tanya favors subsidies for agriculture, Alvin favors school construction, and Rebecca favors the recruitment of more firefighters. It seems as if the proposals are doomed to fail because each is opposed by a majority of voters. Even so, this may not be the outcome. Tanya may visit Rebecca and tell her that she will vote for Rebecca's bill to recruit more firefighters so long as Rebecca votes for her policy, subsidies for agriculture, in return. Now both proposals will win


title: Laser content: Laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light "coherently". Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial


title: Laser content: coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers and lidar. Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light. Alternatively, temporal coherence can be used to produce pulses of light with a broad spectrum but durations as short as a femtosecond ("ultrashort pulses"). Lasers are used in optical disk drives, laser printers, barcode scanners, DNA sequencing instruments, fiber-optic and free-space optical communication, laser surgery and skin treatments, cutting and welding materials,


title: Laser content: military and law enforcement devices for marking targets and measuring range and speed, and in laser lighting displays for entertainment. Lasers are distinguished from other light sources by their coherence. Spatial coherence is typically expressed through the output being a narrow beam, which is diffraction-limited. Laser beams can be focused to very tiny spots, achieving a very high irradiance, or they can have very low divergence in order to concentrate their power at a great distance. Temporal (or longitudinal) coherence implies a polarized wave at a single frequency, whose phase is correlated over a relatively great distance (the coherence length)


title: Laser content: along the beam. A beam produced by a thermal or other incoherent light source has an instantaneous amplitude and phase that vary randomly with respect to time and position, thus having a short coherence length. Lasers are characterized according to their wavelength in a vacuum. Most "single wavelength" lasers actually produce radiation in several "modes" with slightly different wavelengths. Although temporal coherence implies monochromaticity, there are lasers that emit a broad spectrum of light or emit different wavelengths of light simultaneously. Some lasers are not single spatial mode and have light beams that diverge more than is required by the


title: Laser content: diffraction limit. All such devices are classified as "lasers" based on their method of producing light, i.e., stimulated emission. Lasers are employed where light of the required spatial or temporal coherence can not be produced using simpler technologies. The word "laser" started as an acronym for "light amplification by stimulated emission of radiation". In this usage, the term "light" includes electromagnetic radiation of any frequency, not only visible light, hence the terms "infrared laser", "ultraviolet laser", "X-ray laser" and "gamma-ray laser". Because the microwave predecessor of the laser, the maser, was developed first, devices of this sort operating at microwave


title: Laser content: and radio frequencies are referred to as "masers" rather than "microwave lasers" or "radio lasers". In the early technical literature, especially at Bell Telephone Laboratories, the laser was called an optical maser; this term is now obsolete. A laser that produces light by itself is technically an optical oscillator rather than an optical amplifier as suggested by the acronym. It has been humorously noted that the acronym LOSER, for "light oscillation by stimulated emission of radiation", would have been more correct. With the widespread use of the original acronym as a common noun, optical amplifiers have come to be referred


title: Laser content: to as "laser amplifiers", notwithstanding the apparent redundancy in that designation. The back-formed verb "to lase" is frequently used in the field, meaning "to produce laser light," especially in reference to the gain medium of a laser; when a laser is operating it is said to be "lasing." Further use of the words "laser" and "maser" in an extended sense, not referring to laser technology or devices, can be seen in usages such as "astrophysical maser" and "atom laser". A laser consists of a gain medium, a mechanism to energize it, and something to provide optical feedback. The gain medium


title: Laser content: is a material with properties that allow it to amplify light by way of stimulated emission. Light of a specific wavelength that passes through the gain medium is amplified (increases in power). For the gain medium to amplify light, it needs to be supplied with energy in a process called pumping. The energy is typically supplied as an electric current or as light at a different wavelength. Pump light may be provided by a flash lamp or by another laser. The most common type of laser uses feedback from an optical cavity—a pair of mirrors on either end of the


title: Laser content: gain medium. Light bounces back and forth between the mirrors, passing through the gain medium and being amplified each time. Typically one of the two mirrors, the output coupler, is partially transparent. Some of the light escapes through this mirror. Depending on the design of the cavity (whether the mirrors are flat or curved), the light coming out of the laser may spread out or form a narrow beam. In analogy to electronic oscillators, this device is sometimes called a "laser oscillator". Most practical lasers contain additional elements that affect properties of the emitted light, such as the polarization, wavelength,


title: Laser content: and shape of the beam. Electrons and how they interact with electromagnetic fields are important in our understanding of chemistry and physics. In the classical view, the energy of an electron orbiting an atomic nucleus is larger for orbits further from the nucleus of an atom. However, quantum mechanical effects force electrons to take on discrete positions in orbitals. Thus, electrons are found in specific energy levels of an atom, two of which are shown below: When an electron absorbs energy either from light (photons) or heat (phonons), it receives that incident quantum of energy. But transitions are only allowed


title: Laser content: in between discrete energy levels such as the two shown above. This leads to emission lines and absorption lines. When an electron is excited from a lower to a higher energy level, it will not stay that way forever. An electron in an excited state may decay to a lower energy state which is not occupied, according to a particular time constant characterizing that transition. When such an electron decays without external influence, emitting a photon, that is called "spontaneous emission". The phase associated with the photon that is emitted is random. A material with many atoms in such an


title: Laser content: excited state may thus result in radiation which is very spectrally limited (centered around one wavelength of light), but the individual photons would have no common phase relationship and would emanate in random directions. This is the mechanism of fluorescence and thermal emission. An external electromagnetic field at a frequency associated with a transition can affect the quantum mechanical state of the atom. As the electron in the atom makes a transition between two stationary states (neither of which shows a dipole field), it enters a transition state which does have a dipole field, and which acts like a small


title: Laser content: electric dipole, and this dipole oscillates at a characteristic frequency. In response to the external electric field at this frequency, the probability of the atom entering this transition state is greatly increased. Thus, the rate of transitions between two stationary states is enhanced beyond that due to spontaneous emission. Such a transition to the higher state is called absorption, and it destroys an incident photon (the photon's energy goes into powering the increased energy of the higher state). A transition from the higher to a lower energy state, however, produces an additional photon; this is the process of stimulated emission.


title: Laser content: The gain medium is put into an excited state by an external source of energy. In most lasers this medium consists of a population of atoms which have been excited into such a state by means of an outside light source, or an electrical field which supplies energy for atoms to absorb and be transformed into their excited states. The gain medium of a laser is normally a material of controlled purity, size, concentration, and shape, which amplifies the beam by the process of stimulated emission described above. This material can be of any state: gas, liquid, solid, or plasma.


title: Laser content: The gain medium absorbs pump energy, which raises some electrons into higher-energy ("excited") quantum states. Particles can interact with light by either absorbing or emitting photons. Emission can be spontaneous or stimulated. In the latter case, the photon is emitted in the same direction as the light that is passing by. When the number of particles in one excited state exceeds the number of particles in some lower-energy state, population inversion is achieved and the amount of stimulated emission due to light that passes through is larger than the amount of absorption. Hence, the light is amplified. By itself, this


title: Laser content: makes an optical amplifier. When an optical amplifier is placed inside a resonant optical cavity, one obtains a laser oscillator. In a few situations it is possible to obtain lasing with only a single pass of EM radiation through the gain medium, and this produces a laser beam without any need for a resonant or reflective cavity (see for example nitrogen laser). Thus, reflection in a resonant cavity is usually required for a laser, but is not absolutely necessary. The optical resonator is sometimes referred to as an "optical cavity", but this is a misnomer: lasers use open resonators as


title: Laser content: opposed to the literal cavity that would be employed at microwave frequencies in a maser. The resonator typically consists of two mirrors between which a coherent beam of light travels in both directions, reflecting back on itself so that an average photon will pass through the gain medium repeatedly before it is emitted from the output aperture or lost to diffraction or absorption. If the gain (amplification) in the medium is larger than the resonator losses, then the power of the recirculating light can rise exponentially. But each stimulated emission event returns an atom from its excited state to the


title: Laser content: ground state, reducing the gain of the medium. With increasing beam power the net gain (gain minus loss) reduces to unity and the gain medium is said to be saturated. In a continuous wave (CW) laser, the balance of pump power against gain saturation and cavity losses produces an equilibrium value of the laser power inside the cavity; this equilibrium determines the operating point of the laser. If the applied pump power is too small, the gain will never be sufficient to overcome the cavity losses, and laser light will not be produced. The minimum pump power needed to begin


title: Laser content: laser action is called the "lasing threshold". The gain medium will amplify any photons passing through it, regardless of direction; but only the photons in a spatial mode supported by the resonator will pass more than once through the medium and receive substantial amplification. In most lasers, lasing begins with stimulated emission amplifying random spontaneously emitted photons present in the gain medium. Stimulated emission produces light that matches the input signal in wavelength, phase, and polarization. This, combined with the filtering effect of the optical resonator gives laser light its characteristic coherence, and may give it uniform polarization and monochromaticity,


title: Laser content: depending on the resonator's design. Some lasers use a separate injection seeder to start the process off with a beam that is already highly coherent. This can produce beams with a narrower spectrum than would otherwise be possible. Many lasers produce a beam that can be approximated as a Gaussian beam; such beams have the minimum divergence possible for a given beam diameter. Some lasers, particularly high-power ones, produce multimode beams, with the transverse modes often approximated using Hermite–Gaussian or Laguerre-Gaussian functions. Some high power lasers use a flat-topped profile known as a "tophat beam". Unstable laser resonators (not used


title: Laser content: in most lasers) produce fractal-shaped beams. Specialized optical systems can produce more complex beam geometries, such as Bessel beams and optical vortexes. Near the "waist" (or focal region) of a laser beam, it is highly "collimated": the wavefronts are planar, normal to the direction of propagation, with no beam divergence at that point. However, due to diffraction, that can only remain true well within the Rayleigh range. The beam of a single transverse mode (gaussian beam) laser eventually diverges at an angle which varies inversely with the beam diameter, as required by diffraction theory. Thus, the "pencil beam" directly generated


title: Laser content: by a common helium–neon laser would spread out to a size of perhaps 500 kilometers when shone on the Moon (from the distance of the earth). On the other hand, the light from a semiconductor laser typically exits the tiny crystal with a large divergence: up to 50°. However even such a divergent beam can be transformed into a similarly collimated beam by means of a lens system, as is always included, for instance, in a laser pointer whose light originates from a laser diode. That is possible due to the light being of a single spatial mode. This unique


title: Laser content: property of laser light, spatial coherence, cannot be replicated using standard light sources (except by discarding most of the light) as can be appreciated by comparing the beam from a flashlight (torch) or spotlight to that of almost any laser. A laser beam profiler is used to measure the intensity profile, width, and divergence of laser beams. Diffuse reflection of a laser beam from a matte surface produces a speckle pattern with interesting properties. The mechanism of producing radiation in a laser relies on stimulated emission, where energy is extracted from a transition in an atom or molecule. This is


title: Laser content: a quantum phenomenon discovered by Einstein who derived the relationship between the A coefficient describing spontaneous emission and the B coefficient which applies to absorption and stimulated emission. However, in the case of the free electron laser, atomic energy levels are not involved; it appears that the operation of this rather exotic device can be explained without reference to quantum mechanics. A laser can be classified as operating in either continuous or pulsed mode, depending on whether the power output is essentially continuous over time or whether its output takes the form of pulses of light on one or another


title: Laser content: time scale. Of course even a laser whose output is normally continuous can be intentionally turned on and off at some rate in order to create pulses of light. When the modulation rate is on time scales much slower than the cavity lifetime and the time period over which energy can be stored in the lasing medium or pumping mechanism, then it is still classified as a "modulated" or "pulsed" continuous wave laser. Most laser diodes used in communication systems fall in that category. Some applications of lasers depend on a beam whose output power is constant over time. Such


title: Laser content: a laser is known as "continuous wave" ("CW"). Many types of lasers can be made to operate in continuous wave mode to satisfy such an application. Many of these lasers actually lase in several longitudinal modes at the same time, and beats between the slightly different optical frequencies of those oscillations will, in fact, produce amplitude variations on time scales shorter than the round-trip time (the reciprocal of the frequency spacing between modes), typically a few nanoseconds or less. In most cases, these lasers are still termed "continuous wave" as their output power is steady when averaged over any longer


title: Laser content: time periods, with the very high-frequency power variations having little or no impact in the intended application. (However, the term is not applied to mode-locked lasers, where the "intention" is to create very short pulses at the rate of the round-trip time.) For continuous wave operation, it is required for the population inversion of the gain medium to be continually replenished by a steady pump source. In some lasing media, this is impossible. In some other lasers, it would require pumping the laser at a very high continuous power level which would be impractical or destroy the laser by producing


title: Laser content: excessive heat. Such lasers cannot be run in CW mode. Pulsed operation of lasers refers to any laser not classified as continuous wave, so that the optical power appears in pulses of some duration at some repetition rate. This encompasses a wide range of technologies addressing a number of different motivations. Some lasers are pulsed simply because they cannot be run in continuous mode. In other cases, the application requires the production of pulses having as large an energy as possible. Since the pulse energy is equal to the average power divided by the repetition rate, this goal can sometimes


title: Laser content: be satisfied by lowering the rate of pulses so that more energy can be built up in between pulses. In laser ablation, for example, a small volume of material at the surface of a work piece can be evaporated if it is heated in a very short time, while supplying the energy gradually would allow for the heat to be absorbed into the bulk of the piece, never attaining a sufficiently high temperature at a particular point. Other applications rely on the peak pulse power (rather than the energy in the pulse), especially in order to obtain nonlinear optical effects.


title: Laser content: For a given pulse energy, this requires creating pulses of the shortest possible duration utilizing techniques such as Q-switching. The optical bandwidth of a pulse cannot be narrower than the reciprocal of the pulse width. In the case of extremely short pulses, that implies lasing over a considerable bandwidth, quite contrary to the very narrow bandwidths typical of CW lasers. The lasing medium in some "dye lasers" and "vibronic solid-state lasers" produces optical gain over a wide bandwidth, making a laser possible which can thus generate pulses of light as short as a few femtoseconds (10 s). In a Q-switched


title: Laser content: laser, the population inversion is allowed to build up by introducing loss inside the resonator which exceeds the gain of the medium; this can also be described as a reduction of the quality factor or 'Q' of the cavity. Then, after the pump energy stored in the laser medium has approached the maximum possible level, the introduced loss mechanism (often an electro- or acousto-optical element) is rapidly removed (or that occurs by itself in a passive device), allowing lasing to begin which rapidly obtains the stored energy in the gain medium. This results in a short pulse incorporating that energy,


title: Laser content: and thus a high peak power. A mode-locked laser is capable of emitting extremely short pulses on the order of tens of picoseconds down to less than 10 femtoseconds. These pulses will repeat at the round trip time, that is, the time that it takes light to complete one round trip between the mirrors comprising the resonator. Due to the Fourier limit (also known as energy-time uncertainty), a pulse of such short temporal length has a spectrum spread over a considerable bandwidth. Thus such a gain medium must have a gain bandwidth sufficiently broad to amplify those frequencies. An example


title: Laser content: of a suitable material is titanium-doped, artificially grown sapphire (Ti:sapphire) which has a very wide gain bandwidth and can thus produce pulses of only a few femtoseconds duration. Such mode-locked lasers are a most versatile tool for researching processes occurring on extremely short time scales (known as femtosecond physics, femtosecond chemistry and ultrafast science), for maximizing the effect of nonlinearity in optical materials (e.g. in second-harmonic generation, parametric down-conversion, optical parametric oscillators and the like). Due to the large peak power and the ability to generate phase-stabilized trains of ultrafast laser pulses, mode-locking ultrafast lasers underpin precision metrology and spectroscopy


title: Laser content: applications. Another method of achieving pulsed laser operation is to pump the laser material with a source that is itself pulsed, either through electronic charging in the case of flash lamps, or another laser which is already pulsed. Pulsed pumping was historically used with dye lasers where the inverted population lifetime of a dye molecule was so short that a high energy, fast pump was needed. The way to overcome this problem was to charge up large capacitors which are then switched to discharge through flashlamps, producing an intense flash. Pulsed pumping is also required for three-level lasers in which


title: Laser content: the lower energy level rapidly becomes highly populated preventing further lasing until those atoms relax to the ground state. These lasers, such as the excimer laser and the copper vapor laser, can never be operated in CW mode. In 1917, Albert Einstein established the theoretical foundations for the laser and the maser in the paper "Zur Quantentheorie der Strahlung" (On the Quantum Theory of Radiation) via a re-derivation of Max Planck's law of radiation, conceptually based upon probability coefficients (Einstein coefficients) for the absorption, spontaneous emission, and stimulated emission of electromagnetic radiation. In 1928, Rudolf W. Ladenburg confirmed the existence


title: Laser content: of the phenomena of stimulated emission and negative absorption. In 1939, Valentin A. Fabrikant predicted the use of stimulated emission to amplify "short" waves. In 1947, Willis E. Lamb and R.C. Retherford found apparent stimulated emission in hydrogen spectra and effected the first demonstration of stimulated emission. In 1950, Alfred Kastler (Nobel Prize for Physics 1966) proposed the method of optical pumping, experimentally confirmed, two years later, by Brossel, Kastler, and Winter. In 1951, Joseph Weber submitted a paper on using stimulated emissions to make a microwave amplifier to the June 1952 Institute of Radio Engineers Vacuum Tube Research Conference


title: Laser content: at Ottawa, Ontario, Canada. After this presentation, RCA asked Weber to give a seminar on this idea, and Charles Hard Townes asked him for a copy of the paper. In 1953, Charles Hard Townes and graduate students James P. Gordon and Herbert J. Zeiger produced the first microwave amplifier, a device operating on similar principles to the laser, but amplifying microwave radiation rather than infrared or visible radiation. Townes's maser was incapable of continuous output. Meanwhile, in the Soviet Union, Nikolay Basov and Aleksandr Prokhorov were independently working on the quantum oscillator and solved the problem of continuous-output systems by


title: Laser content: using more than two energy levels. These gain media could release stimulated emissions between an excited state and a lower excited state, not the ground state, facilitating the maintenance of a population inversion. In 1955, Prokhorov and Basov suggested optical pumping of a multi-level system as a method for obtaining the population inversion, later a main method of laser pumping. Townes reports that several eminent physicists—among them Niels Bohr, John von Neumann, and Llewellyn Thomas—argued the maser violated Heisenberg's uncertainty principle and hence could not work. Others such as Isidor Rabi and Polykarp Kusch expected that it would be impractical


title: Laser content: and not worth the effort. In 1964 Charles H. Townes, Nikolay Basov, and Aleksandr Prokhorov shared the Nobel Prize in Physics, "for fundamental work in the field of quantum electronics, which has led to the construction of oscillators and amplifiers based on the maser–laser principle". In 1957, Charles Hard Townes and Arthur Leonard Schawlow, then at Bell Labs, began a serious study of the infrared laser. As ideas developed, they abandoned infrared radiation to instead concentrate upon visible light. The concept originally was called an "optical maser". In 1958, Bell Labs filed a patent application for their proposed optical maser;


title: Laser content: and Schawlow and Townes submitted a manuscript of their theoretical calculations to the "Physical Review", published that year in Volume 112, Issue No. 6. Simultaneously, at Columbia University, graduate student Gordon Gould was working on a doctoral thesis about the energy levels of excited thallium. When Gould and Townes met, they spoke of radiation emission, as a general subject; afterwards, in November 1957, Gould noted his ideas for a "laser", including using an open resonator (later an essential laser-device component). Moreover, in 1958, Prokhorov independently proposed using an open resonator, the first published appearance (in the USSR) of this idea.


title: Laser content: Elsewhere, in the U.S., Schawlow and Townes had agreed to an open-resonator laser design – apparently unaware of Prokhorov's publications and Gould's unpublished laser work. At a conference in 1959, Gordon Gould published the term LASER in the paper "The LASER, Light Amplification by Stimulated Emission of Radiation". Gould's linguistic intention was using the "-aser" word particle as a suffix – to accurately denote the spectrum of the light emitted by the LASER device; thus x-rays: "xaser", ultraviolet: "uvaser", et cetera; none established itself as a discrete term, although "raser" was briefly popular for denoting radio-frequency-emitting devices. Gould's notes included


title: Laser content: possible applications for a laser, such as spectrometry, interferometry, radar, and nuclear fusion. He continued developing the idea, and filed a patent application in April 1959. The U.S. Patent Office denied his application, and awarded a patent to Bell Labs, in 1960. That provoked a twenty-eight-year lawsuit, featuring scientific prestige and money as the stakes. Gould won his first minor patent in 1977, yet it was not until 1987 that he won the first significant patent lawsuit victory, when a Federal judge ordered the U.S. Patent Office to issue patents to Gould for the optically pumped and the gas discharge


title: Laser content: laser devices. The question of just how to assign credit for inventing the laser remains unresolved by historians. On May 16, 1960, Theodore H. Maiman operated the first functioning laser at Hughes Research Laboratories, Malibu, California, ahead of several research teams, including those of Townes, at Columbia University, Arthur Schawlow, at Bell Labs, and Gould, at the TRG (Technical Research Group) company. Maiman's functional laser used a solid-state flashlamp-pumped synthetic ruby crystal to produce red laser light, at 694 nanometers wavelength; however, the device only was capable of pulsed operation, because of its three-level pumping design scheme. Later that year,


title: Laser content: the Iranian physicist Ali Javan, and William R. Bennett, and Donald Herriott, constructed the first gas laser, using helium and neon that was capable of continuous operation in the infrared (U.S. Patent 3,149,290); later, Javan received the Albert Einstein Award in 1993. Basov and Javan proposed the semiconductor laser diode concept. In 1962, Robert N. Hall demonstrated the first "laser diode" device, which was made of gallium arsenide and emitted in the near-infrared band of the spectrum at 850 nm. Later that year, Nick Holonyak, Jr. demonstrated the first semiconductor laser with a visible emission. This first semiconductor laser could


title: Laser content: only be used in pulsed-beam operation, and when cooled to liquid nitrogen temperatures (77 K). In 1970, Zhores Alferov, in the USSR, and Izuo Hayashi and Morton Panish of Bell Telephone Laboratories also independently developed room-temperature, continual-operation diode lasers, using the heterojunction structure. Since the early period of laser history, laser research has produced a variety of improved and specialized laser types, optimized for different performance goals, including: and this research continues to this day. In 2017, researchers at TU Delft demonstrated an AC Josephson junction microwave laser. Since the laser operates in the superconducting regime, it is more stable


title: Laser content: than other semiconductor-based lasers. The device has potential for applications in quantum computing. In 2017, researchers at TU Munich demonstrated the smallest mode locking laser capable of emitting pairs of phase-locked picosecond laser pulses with a repetition frequency up to 200 GHz. In 2017, researchers from the Physikalisch-Technische Bundesanstalt (PTB), together with US researchers from JILA, a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder, established a new world record by developing an erbium-doped fiber laser with a linewidth of only 10 millihertz. Following the invention of the HeNe gas laser,


title: Laser content: many other gas discharges have been found to amplify light coherently. Gas lasers using many different gases have been built and used for many purposes. The helium–neon laser (HeNe) is able to operate at a number of different wavelengths, however the vast majority are engineered to lase at 633 nm; these relatively low cost but highly coherent lasers are extremely common in optical research and educational laboratories. Commercial carbon dioxide (CO) lasers can emit many hundreds of watts in a single spatial mode which can be concentrated into a tiny spot. This emission is in the thermal infrared at 10.6


title: Laser content: µm; such lasers are regularly used in industry for cutting and welding. The efficiency of a CO laser is unusually high: over 30%. Argon-ion lasers can operate at a number of lasing transitions between 351 and 528.7 nm. Depending on the optical design one or more of these transitions can be lasing simultaneously; the most commonly used lines are 458 nm, 488 nm and 514.5 nm. A nitrogen transverse electrical discharge in gas at atmospheric pressure (TEA) laser is an inexpensive gas laser, often home-built by hobbyists, which produces rather incoherent UV light at 337.1 nm. Metal ion lasers are


title: Laser content: gas lasers that generate deep ultraviolet wavelengths. Helium-silver (HeAg) 224 nm and neon-copper (NeCu) 248 nm are two examples. Like all low-pressure gas lasers, the gain media of these lasers have quite narrow oscillation linewidths, less than 3 GHz (0.5 picometers), making them candidates for use in fluorescence suppressed Raman spectroscopy. Chemical lasers are powered by a chemical reaction permitting a large amount of energy to be released quickly. Such very high power lasers are especially of interest to the military, however continuous wave chemical lasers at very high power levels, fed by streams of gasses, have been developed and


title: Laser content: have some industrial applications. As examples, in the hydrogen fluoride laser (2700–2900 nm) and the deuterium fluoride laser (3800 nm) the reaction is the combination of hydrogen or deuterium gas with combustion products of ethylene in nitrogen trifluoride. Excimer lasers are a special sort of gas laser powered by an electric discharge in which the lasing medium is an excimer, or more precisely an exciplex in existing designs. These are molecules which can only exist with one atom in an excited electronic state. Once the molecule transfers its excitation energy to a photon, its atoms are no longer bound to


title: Laser content: each other and the molecule disintegrates. This drastically reduces the population of the lower energy state thus greatly facilitating a population inversion. Excimers currently used are all ; noble gasses are chemically inert and can only form compounds while in an excited state. Excimer lasers typically operate at ultraviolet wavelengths with major applications including semiconductor photolithography and LASIK eye surgery. Commonly used excimer molecules include ArF (emission at 193 nm), KrCl (222 nm), KrF (248 nm), XeCl (308 nm), and XeF (351 nm). The molecular fluorine laser, emitting at 157 nm in the vacuum ultraviolet is sometimes referred to as


title: Laser content: an excimer laser, however this appears to be a misnomer inasmuch as F is a stable compound. Solid-state lasers use a crystalline or glass rod which is "doped" with ions that provide the required energy states. For example, the first working laser was a ruby laser, made from ruby (chromium-doped corundum). The population inversion is actually maintained in the dopant. These materials are pumped optically using a shorter wavelength than the lasing wavelength, often from a flashtube or from another laser. The usage of the term "solid-state" in laser physics is narrower than in typical use. Semiconductor lasers (laser diodes)


title: Laser content: are typically "not" referred to as solid-state lasers. Neodymium is a common dopant in various solid-state laser crystals, including yttrium orthovanadate (Nd:YVO), yttrium lithium fluoride () and yttrium aluminium garnet (). All these lasers can produce high powers in the infrared spectrum at 1064 nm. They are used for cutting, welding and marking of metals and other materials, and also in spectroscopy and for pumping dye lasers. These lasers are also commonly frequency doubled, tripled or quadrupled to produce 532 nm (green, visible), 355 nm and 266 nm (UV) beams, respectively. Frequency-doubled diode-pumped solid-state (DPSS) lasers are used to make


title: Laser content: bright green laser pointers. Ytterbium, holmium, thulium, and erbium are other common "dopants" in solid-state lasers. Ytterbium is used in crystals such as Yb:YAG, Yb:KGW, Yb:KYW, Yb:SYS, Yb:BOYS, Yb:CaF, typically operating around 1020–1050 nm. They are potentially very efficient and high powered due to a small quantum defect. Extremely high powers in ultrashort pulses can be achieved with Yb:YAG. Holmium-doped YAG crystals emit at 2097 nm and form an efficient laser operating at infrared wavelengths strongly absorbed by water-bearing tissues. The Ho-YAG is usually operated in a pulsed mode, and passed through optical fiber surgical devices to resurface joints, remove


title: Laser content: rot from teeth, vaporize cancers, and pulverize kidney and gall stones. Titanium-doped sapphire (Ti:sapphire) produces a highly tunable infrared laser, commonly used for spectroscopy. It is also notable for use as a mode-locked laser producing ultrashort pulses of extremely high peak power. Thermal limitations in solid-state lasers arise from unconverted pump power that heats the medium. This heat, when coupled with a high thermo-optic coefficient (d"n"/d"T") can cause thermal lensing and reduce the quantum efficiency. Diode-pumped thin disk lasers overcome these issues by having a gain medium that is much thinner than the diameter of the pump beam. This allows


title: Laser content: for a more uniform temperature in the material. Thin disk lasers have been shown to produce beams of up to one kilowatt. Solid-state lasers or laser amplifiers where the light is guided due to the total internal reflection in a single mode optical fiber are instead called fiber lasers. Guiding of light allows extremely long gain regions providing good cooling conditions; fibers have high surface area to volume ratio which allows efficient cooling. In addition, the fiber's waveguiding properties tend to reduce thermal distortion of the beam. Erbium and ytterbium ions are common active species in such lasers. Quite often,


title: Laser content: the fiber laser is designed as a double-clad fiber. This type of fiber consists of a fiber core, an inner cladding and an outer cladding. The index of the three concentric layers is chosen so that the fiber core acts as a single-mode fiber for the laser emission while the outer cladding acts as a highly multimode core for the pump laser. This lets the pump propagate a large amount of power into and through the active inner core region, while still having a high numerical aperture (NA) to have easy launching conditions. Pump light can be used more efficiently


title: Laser content: by creating a fiber disk laser, or a stack of such lasers. Fiber lasers have a fundamental limit in that the intensity of the light in the fiber cannot be so high that optical nonlinearities induced by the local electric field strength can become dominant and prevent laser operation and/or lead to the material destruction of the fiber. This effect is called photodarkening. In bulk laser materials, the cooling is not so efficient, and it is difficult to separate the effects of photodarkening from the thermal effects, but the experiments in fibers show that the photodarkening can be attributed to


title: Laser content: the formation of long-living color centers. Photonic crystal lasers are lasers based on nano-structures that provide the mode confinement and the density of optical states (DOS) structure required for the feedback to take place. They are typical micrometer-sized and tunable on the bands of the photonic crystals. Semiconductor lasers are diodes which are electrically pumped. Recombination of electrons and holes created by the applied current introduces optical gain. Reflection from the ends of the crystal form an optical resonator, although the resonator can be external to the semiconductor in some designs. Commercial laser diodes emit at wavelengths from 375 nm


title: Laser content: to 3500 nm. Low to medium power laser diodes are used in laser pointers, laser printers and CD/DVD players. Laser diodes are also frequently used to optically pump other lasers with high efficiency. The highest power industrial laser diodes, with power up to 20 kW, are used in industry for cutting and welding. External-cavity semiconductor lasers have a semiconductor active medium in a larger cavity. These devices can generate high power outputs with good beam quality, wavelength-tunable narrow-linewidth radiation, or ultrashort laser pulses. In 2012, Nichia and OSRAM developed and manufactured commercial high-power green laser diodes (515/520 nm), which compete


title: Laser content: with traditional diode-pumped solid-state lasers. Vertical cavity surface-emitting lasers (VCSELs) are semiconductor lasers whose emission direction is perpendicular to the surface of the wafer. VCSEL devices typically have a more circular output beam than conventional laser diodes. As of 2005, only 850 nm VCSELs are widely available, with 1300 nm VCSELs beginning to be commercialized, and 1550 nm devices an area of research. VECSELs are external-cavity VCSELs. Quantum cascade lasers are semiconductor lasers that have an active transition between energy "sub-bands" of an electron in a structure containing several quantum wells. The development of a silicon laser is important in


title: Laser content: the field of optical computing. Silicon is the material of choice for integrated circuits, and so electronic and silicon photonic components (such as optical interconnects) could be fabricated on the same chip. Unfortunately, silicon is a difficult lasing material to deal with, since it has certain properties which block lasing. However, recently teams have produced silicon lasers through methods such as fabricating the lasing material from silicon and other semiconductor materials, such as indium(III) phosphide or gallium(III) arsenide, materials which allow coherent light to be produced from silicon. These are called hybrid silicon laser. Recent developments have also shown the


title: Laser content: use of monolithically integrated nanowire lasers directly on silicon for optical interconnects, paving the way for chip level applications. These heterostructure nanowire lasers capable of optical interconnects in silicon are also capable of emitting pairs of phase-locked picosecond pulses with a repetition frequency up to 200 GHz, allowing for on-chip optical signal processing. Another type is a Raman laser, which takes advantage of Raman scattering to produce a laser from materials such as silicon. Lasing without maintaining the medium excited into a population inversion was demonstrated in 1992 in sodium gas and again in 1995 in rubidium gas by various


title: Laser content: international teams. This was accomplished by using an external maser to induce "optical transparency" in the medium by introducing and destructively interfering the ground electron transitions between two paths, so that the likelihood for the ground electrons to absorb any energy has been cancelled. Dye lasers use an organic dye as the gain medium. The wide gain spectrum of available dyes, or mixtures of dyes, allows these lasers to be highly tunable, or to produce very short-duration pulses (on the order of a few femtoseconds). Although these tunable lasers are mainly known in their liquid form, researchers have also demonstrated


title: Laser content: narrow-linewidth tunable emission in dispersive oscillator configurations incorporating solid-state dye gain media. In their most prevalent form these solid state dye lasers use dye-doped polymers as laser media. Free-electron lasers, or FELs, generate coherent, high power radiation that is widely tunable, currently ranging in wavelength from microwaves through terahertz radiation and infrared to the visible spectrum, to soft X-rays. They have the widest frequency range of any laser type. While FEL beams share the same optical traits as other lasers, such as coherent radiation, FEL operation is quite different. Unlike gas, liquid, or solid-state lasers, which rely on bound atomic


title: Laser content: or molecular states, FELs use a relativistic electron beam as the lasing medium, hence the term "free-electron". The pursuit of a high-quantum-energy laser using transitions between isomeric states of an atomic nucleus has been the subject of wide-ranging academic research since the early 1970s. Much of this is summarized in three review articles. This research has been international in scope, but mainly based in the former Soviet Union and the United States. While many scientists remain optimistic that a breakthrough is near, an operational gamma-ray laser is yet to be realized. Some of the early studies were directed toward short


title: Laser content: pulses of neutrons exciting the upper isomer state in a solid so the gamma-ray transition could benefit from the line-narrowing of Mössbauer effect. In conjunction, several advantages were expected from two-stage pumping of a three-level system. It was conjectured that the nucleus of an atom, embedded in the near field of a laser-driven coherently-oscillating electron cloud would experience a larger dipole field than that of the driving laser. Furthermore, nonlinearity of the oscillating cloud would produce both spatial and temporal harmonics, so nuclear transitions of higher multipolarity could also be driven at multiples of the laser frequency. In September 2007,


title: Laser content: the BBC News reported that there was speculation about the possibility of using positronium annihilation to drive a very powerful gamma ray laser. Dr. David Cassidy of the University of California, Riverside proposed that a single such laser could be used to ignite a nuclear fusion reaction, replacing the banks of hundreds of lasers currently employed in inertial confinement fusion experiments. Space-based X-ray lasers pumped by a nuclear explosion have also been proposed as antimissile weapons. Such devices would be one-shot weapons. Living cells have been used to produce laser light. The cells were genetically engineered to produce green fluorescent


title: Laser content: protein (GFP). The GFP is used as the laser's "gain medium", where light amplification takes place. The cells were then placed between two tiny mirrors, just 20 millionths of a meter across, which acted as the "laser cavity" in which light could bounce many times through the cell. Upon bathing the cell with blue light, it could be seen to emit directed and intense green laser light. When lasers were invented in 1960, they were called "a solution looking for a problem". Since then, they have become ubiquitous, finding utility in thousands of highly varied applications in every section of


title: Laser content: modern society, including consumer electronics, information technology, science, medicine, industry, law enforcement, entertainment, and the military. Fiber-optic communication using lasers is a key technology in modern communications, allowing services such as the Internet. The first use of lasers in the daily lives of the general population was the supermarket barcode scanner, introduced in 1974. The laserdisc player, introduced in 1978, was the first successful consumer product to include a laser but the compact disc player was the first laser-equipped device to become common, beginning in 1982 followed shortly by laser printers. Some other uses are: In 2004, excluding diode lasers,


title: Laser content: approximately 131,000 lasers were sold with a value of US$2.19 billion. In the same year, approximately 733 million diode lasers, valued at $3.20 billion, were sold. Lasers have many uses in medicine, including laser surgery (particularly eye surgery), laser healing, kidney stone treatment, ophthalmoscopy, and cosmetic skin treatments such as acne treatment, cellulite and striae reduction, and hair removal. Lasers are used to treat cancer by shrinking or destroying tumors or precancerous growths. They are most commonly used to treat superficial cancers that are on the surface of the body or the lining of internal organs. They are used to


title: Laser content: treat basal cell skin cancer and the very early stages of others like cervical, penile, vaginal, vulvar, and non-small cell lung cancer. Laser therapy is often combined with other treatments, such as surgery, chemotherapy, or radiation therapy. Laser-induced interstitial thermotherapy (LITT), or interstitial laser photocoagulation, uses lasers to treat some cancers using hyperthermia, which uses heat to shrink tumors by damaging or killing cancer cells. Lasers are more precise than traditional surgery methods and cause less damage, pain, bleeding, swelling, and scarring. A disadvantage is that surgeons must have specialized training. It may be more expensive than other treatments. Many


title: Laser content: types of laser can potentially be used as incapacitating weapons, through their ability to produce temporary or permanent vision loss when aimed at the eyes. The degree, character, and duration of vision impairment caused by eye exposure to laser light varies with the power of the laser, the wavelength(s), the collimation of the beam, the exact orientation of the beam, and the duration of exposure. Lasers of even a fraction of a watt in power can produce immediate, permanent vision loss under certain conditions, making such lasers potential non-lethal but incapacitating weapons. The extreme handicap that laser-induced blindness represents makes


title: Laser content: the use of lasers even as non-lethal weapons morally controversial, and weapons designed to cause permanent blindness have been banned by the Protocol on Blinding Laser Weapons. Weapons designed to cause temporary blindness, known as dazzlers, are used by military and sometimes law enforcement organizations. Incidents of pilots being exposed to lasers while flying have prompted aviation authorities to implement special procedures to deal with such hazards. See Lasers and aviation safety for more on this topic. Laser weapons capable of directly damaging or destroying a target in combat are still in the experimental stage. The general idea of laser-beam


title: Laser content: weaponry is to hit a target with a train of brief pulses of light. The rapid evaporation and expansion of the surface causes shockwaves that damage the target. The power needed to project a high-powered laser beam of this kind is beyond the limit of current mobile power technology, thus favoring chemically powered gas dynamic lasers. Example experimental systems include MIRACL and the Tactical High Energy Laser. Throughout the 2000s, the United States Air Force worked on the Boeing YAL-1, an airborne laser mounted in a Boeing 747. It was intended to be used to shoot down incoming ballistic missiles


title: Laser content: over enemy territory. In March 2009, Northrop Grumman claimed that its engineers in Redondo Beach had successfully built and tested an electrically powered solid state laser capable of producing a 100-kilowatt beam, powerful enough to destroy an airplane. According to Brian Strickland, manager for the United States Army's Joint High Power Solid State Laser program, an electrically powered laser is capable of being mounted in an aircraft, ship, or other vehicle because it requires much less space for its supporting equipment than a chemical laser. However, the source of such a large electrical power in a mobile application remained unclear.


title: Laser content: Ultimately, the project was deemed to be infeasible, and was cancelled in December 2011, with the Boeing YAL-1 prototype being stored and eventually dismantled. The United States Navy is developing a laser weapon referred to as the Laser Weapon System or LaWS. In recent years, some hobbyists have taken interests in lasers. Lasers used by hobbyists are generally of class IIIa or IIIb (see Safety), although some have made their own class IV types. However, compared to other hobbyists, laser hobbyists are far less common, due to the cost and potential dangers involved. Due to the cost of lasers, some


title: Laser content: hobbyists use inexpensive means to obtain lasers, such as salvaging laser diodes from broken DVD players (red), Blu-ray players (violet), or even higher power laser diodes from CD or DVD burners. Hobbyists also have been taking surplus pulsed lasers from retired military applications and modifying them for pulsed holography. Pulsed Ruby and pulsed YAG lasers have been used. Different applications need lasers with different output powers. Lasers that produce a continuous beam or a series of short pulses can be compared on the basis of their average power. Lasers that produce pulses can also be characterized based on the "peak"


title: Laser content: power of each pulse. The peak power of a pulsed laser is many orders of magnitude greater than its average power. The average output power is always less than the power consumed. Examples of pulsed systems with high peak power: Even the first laser was recognized as being potentially dangerous. Theodore Maiman characterized the first laser as having a power of one "Gillette" as it could burn through one Gillette razor blade. Today, it is accepted that even low-power lasers with only a few milliwatts of output power can be hazardous to human eyesight when the beam hits the eye


title: Laser content: directly or after reflection from a shiny surface. At wavelengths which the cornea and the lens can focus well, the coherence and low divergence of laser light means that it can be focused by the eye into an extremely small spot on the retina, resulting in localized burning and permanent damage in seconds or even less time. Lasers are usually labeled with a safety class number, which identifies how dangerous the laser is: The indicated powers are for visible-light, continuous-wave lasers. For pulsed lasers and invisible wavelengths, other power limits apply. People working with class 3B and class 4 lasers


title: Laser content: can protect their eyes with safety goggles which are designed to absorb light of a particular wavelength. Infrared lasers with wavelengths longer than about 1.4 micrometers are often referred to as "eye-safe", because the cornea tends to absorb light at these wavelengths, protecting the retina from damage. The label "eye-safe" can be misleading, however, as it applies only to relatively low power continuous wave beams; a high power or Q-switched laser at these wavelengths can burn the cornea, causing severe eye damage, and even moderate power lasers can injure the eye. Lasers can be a hazard to both civil and


title: Laser content: miliatary aviation, due to the potential to temporarily distract or blind pilots. See Lasers and aviation safety for more on this topic. Laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light


title: Lavandula content: when compared to rosemary. The potency of the lavender flowers increases with drying which necessitates more sparing use to avoid a heavy, soapy aftertaste. Chefs note to reduce by two-thirds the dry amount in recipes which call for fresh lavender buds. Lavender buds can amplify both sweet and savory flavors in dishes, and are sometimes paired with sheep's-milk and goat's-milk cheeses. Lavender flowers are occasionally blended with black, green, or herbal teas. Lavender flavours baked goods and desserts, pairing especially well with chocolate. In the United States, both lavender syrup and dried lavender buds are used to make lavender scones


title: "Lemon balm" content: Lemon balm Lemon balm ("Melissa officinalis"), balm, common balm, or balm mint, is a perennial herbaceous plant in the mint family Lamiaceae and native to south-central Europe, the Mediterranean Basin, Iran, and Central Asia, but now naturalized in the Americas and elsewhere. It grows to a maximum height of . The leaves have a mild lemon scent similar to mint. During summer, small white flowers full of nectar appear. It is not to be confused with bee balm (genus "Monarda"), although the white flowers attract bees, hence the genus "Melissa" (Greek for "honey bee"). The leaves are used as a


title: "Lemon balm" content: herb, in teas, and also as a flavouring. The plant is used to attract bees for honey production. It is grown as an ornamental plant and for its oil (to use in perfumery). The tea of lemon balm, the essential oil, and the extract are used in traditional and alternative medicine, including aromatherapy. The plant has been cultivated at least since the 16th century, but research is still being conducted to establish the safety and effects of lemon balm. Sources date the medicinal use of lemon balm to over 2000 years ago through the Greeks and Romans. Further mention is


title: "Lemon balm" content: found in Theophrastus’s "Historia Plantarum", dated to around 300 BC. Lemon balm was formally introduced into Spain in the 7 century, from which its use and domestication spread throughout Europe. Its use in the Middle Ages is noted by herbalists, writers, philosophers, and scientists, with Swiss physician and alchemist, Paracelsus, deeming it the “elixir of life” . Lemon balm was introduced to North America with the arrival of early colonists, and is recorded to have been among the herbs cultivated in Thomas Jefferson’s garden. The plant is used to attract bees to make honey. It is also grown and sold


title: "Lemon balm" content: as an ornamental plant. The essential oil is used as a perfume ingredient, but the plant has other culinary and medicinal uses. Lemon balm is used in some toothpastes. Lemon balm is used as a flavouring in ice cream and herbal teas, both hot and iced, often in combination with other herbs such as spearmint. It is a common addition to peppermint tea, mostly because of its complementing flavor. Lemon balm is also paired with fruit dishes or candies. Additionally, it can be used in fish dishes and is the main ingredient in "lemon balm pesto". Its flavour comes from


title: "Lemon balm" content: citronellal (24%), geranial (16%), linalyl acetate (12%) and caryophyllene (12%). It is also one of the ingredients in Spreewald gherkins. In traditional Austrian medicine, "M. officinalis" leaves have been prescribed for internal use—as a tea—or external application—as an essential oil—for the treatment of disorders of the gastrointestinal tract, nervous system, liver, and bile. Lemon balm is the main ingredient of Carmelite water, which is still for sale in German pharmacies. In alternative medicine it is used as a sleep aid and digestive aid. Lemon balm essential oil is popular in aromatherapy. The essential oil is commonly co-distilled with lemon oil,


title: "Lemon balm" content: citronella oil or other oils. "M. officinalis" is native to Europe, central Asia and Iran, but is now naturalized around the world. Lemon balm seeds require light and at least 20 °C (70 °F) to germinate. Lemon balm grows in clumps and spreads vegetatively, as well as by seed. In mild temperate zones, the stems of the plant die off at the start of the winter, but shoot up again in spring. Lemon balm grows vigorously; it should not be planted where it will spread into other plantings. "M. officinalis" may be the "honey-leaf" (μελισσόφυλλον) mentioned by Theophrastus. It was


title: "Lemon balm" content: in the herbal garden of John Gerard, 1596. As of 1992 the major producing countries were Hungary, Egypt, Italy for herb, Ireland for essential oil. The many cultivars of "M. officinalis" include: Lemon balm, including lemon balm extract, has been shown to improve sleep quality. Children patients have displayed improvement in restlessness and dyssomnia with the ingestion of lemon balm extract. Further evidence has demonstrated a significant reduction in levels of insomnia. Lemon balm is commonly associated with anti-stress and anti-anxiety. Studies have shown a significant increase in calmness in healthy patients exposed to lemon balm when compared to placebo.


title: "Lemon balm" content: In addition, lemon balm ingestion is linked to improvement in mood and cognitive performance. Gender and administration length appear to have an impact on the effectiveness of lemon balm as a treatment for depression. Several studies have demonstrated the lemon balm’s antioxidant activity, obtained through high amounts of flavonoids, rosmaric acid, gallic acid and phenolic contents. Lemon balm has also been shown to possess antimicrobial, antiviral, antispasmodic and antitumoral properties. The composition and pharmacology and potential uses of lemon balm have been extensively studied, especially with regard to its traditional uses. Randomized, double-blinded clinical studies in people, however, have been


title: "Lemon balm" content: limited and have had few subjects. Those studies cannot be used for generalized conclusions about the safety or efficacy of lemon balm and its components; what doses are safe and effective is especially not clear. Lemon balm contains eugenol, tannins, and terpenes. It also contains (+)-citronellal, 1-octen-3-ol, 10-α-cadinol, 3-octanol, 3-octanone, α-cubebene, α-humulene, β-bourbonene, caffeic acid, caryophyllene, caryophyllene oxide, catechin, chlorogenic acid, "cis"-3-hexenol, "cis"-ocimene, citral A, citral B, copaene, δ-cadinene, eugenyl acetate, γ-cadinene, geranial, geraniol, geranyl acetate, germacrene D, isogeranial, linalool, luteolin-7-glucoside, methylheptenone, neral, nerol, octyl benzoate, oleanolic acid, pomolic acid ((1"R")-hydroxyursolic acid), protocatechuic acid, rhamnazin, rosmarinic acid, stachyose, succinic acid,


title: "Lemon balm" content: thymol, "trans"-ocimene and ursolic acid. Lemon balm may contain traces of harmine. Rosmarinic acid appears to be the most important active component, but the interaction of chemicals within lemon balm, and with chemicals in other herbs with which it has been commonly used in traditional medicines, is poorly understood. Lemon balm leaf contains roughly 36.5 ± 0.8 mg rosmarinic acid per gram. Lemon balm Lemon balm ("Melissa officinalis"), balm, common balm, or balm mint, is a perennial herbaceous plant in the mint family Lamiaceae and native to south-central Europe, the Mediterranean Basin, Iran, and Central Asia, but now naturalized in


title: "Geography of Laos" content: additional hydroelectric facilities, foreign demands for wild animals and nonwood forest products for food and traditional medicines, and a growing population have brought new and increasing attention to the forests. Traditionally, forests have been important sources of wild foods, herbal medicines, and timber for house construction. Soils are found commonly throughout the floodplains. Typically, soils are formed from alluvium deposited by the rivers as either sandy clay in light colors or sand clay with gray or yellow colors. Upland soils derive from granitic, schistose, or sandstone parent rocks more acidic and less fertile. Southern Laos has areas of laterite soils,


title: "Transport in Laos" content: project. In October 2010, plans were announced for a standard gauge railway linking Vientiane to Xishuangbanna, in Yunnan province in China. Construction was expected to begin in 2011, for completion in 2014. There were plans to extend this railway south from Vientiane to Bangkok. However, in April 2011 it was reported that construction of the railway has been postponed indefinitely, while the Chinese Minister of Railways Liu Zhijun has been arrested on corruption charges. In October 2012, it was announced again that an agreement with China about the construction of a railway from Vientiane to the Chinese border is to


title: "Komodo dragon" content: Komodo dragon The Komodo dragon ("Varanus komodoensis"), also known as the Komodo monitor, is a species of lizard found in the Indonesian islands of Komodo, Rinca, Flores, Gili Motang, and Padar. A member of the monitor lizard family Varanidae, it is the largest living species of lizard, growing to a maximum length of in rare cases and weighing up to approximately . Their unusually large size has been attributed to island gigantism, since no other carnivorous animals fill the niche on the islands where they live. However, recent research suggests the large size of Komodo dragons may be better understood


title: "Komodo dragon" content: as representative of a relict population of very large varanid lizards that once lived across Indonesia and Australia, most of which, along with other megafauna, died out after the Pleistocene (as a result of human activity). Fossils very similar to "V. komodoensis" have been found in Australia dating to greater than 3.8 million years ago, and its body size remained stable on Flores, one of the handful of Indonesian islands where it is currently found, over the last 900,000 years, "a time marked by major faunal turnovers, extinction of the island's megafauna, and the arrival of early hominids by 880


title: "Komodo dragon" content: ka [kiloannums]." As a result of their size, these lizards dominate the ecosystems in which they live. Komodo dragons hunt and ambush prey including invertebrates, birds, and mammals. It has been claimed that they have a venomous bite; there are two glands in the lower jaw which secrete several toxic proteins. The biological significance of these proteins is disputed, but the glands have been shown to secrete an anticoagulant. Komodo dragons' group behaviour in hunting is exceptional in the reptile world. The diet of big Komodo dragons mainly consists of Timor deer, though they also eat considerable amounts of carrion.