title: Operation Searchlight

text: 26 FF attacked the 3 EBR barracks on 30 March (1 April, 3:00 am, according to other sources) with 23rd Field regiment guns providing fire support. Captain Fida was killed at the beginning of the battle, and the surviving EBR was finally forced to retreat after a bloody firefight that took a heavy toll on both sides. The initial attack on the Bengali positions was launched from the north, the second from the north west, while small groups of Pakistani troops infiltrated the positions to take out defensive strong points.


title: Operation Searchlight

text: After a few hours, surviving Bengali troops decided to retreat and left their position in 2 groups, having suffered 55 casualties out of 120 soldiers. Families were left behind and after some Pakistani soldiers abused them (including raping the wives of officers), they were moved to the Saidpur and Rangpur jail. Several Bengali officers attached to the 23rd Brigade were executed while several Bengali officers were sent to West Pakistan.


title: Operation Searchlight

text: EPR 10th wing troops had taken control of the Tista bridge on 28 March, and had deployed 2 companies near the bridge, 1 at Lalmanirhat airfield and the other 2 at Kurigram and Mogolhut. No clashes with Pakistani troops took place until 1 April.


title: Operation Searchlight

text: Helicopters began ferrying 48 Punjab and 4 FF troops began to Rangpur after the disarming of Bengali troops. On 1 April a 4 FF platoon probed the area around Tista Bridge, and in the ensuing clash Maj. Ejaj was killed. The following day an infantry company with 29 cavalry reconnaissance troops moved to the bridge. They directed artillery on the Bengali position and with the aid of air strikes and tanks managed to force the Bengalis to fall back slightly by evening.


title: Operation Searchlight

text: Another Pakistani column moved north and crossed the river at a different point and attacked and captured Lalmunirhat airfield. The outflanked EPR troops abandoned the bridge, and by 4 April the airport was fully operational, with troops and supplies being flown in and families flown out. Apart from small hit and run attacks, Pakistani position remained secured north of the Tista river. On 11 April around 3:30 am 4 EPR companies attacked the airfield, but Pakistani resistance forced them to break off the attack at daybreak.


title: Operation Searchlight

text: EPR troops at Thakurgaon began to take up positions north of Saidpur from 31 March. On 2 April, Bengali officers and EPR JCOs of 8 and 9 wings decided to deploy troops around Saidpur. Thakurgaon EPR contingent moved to Nilphamari to the north of Saidpur, Bhushibandar to the west of it. Small contingents were deployed in areas in between these two positions. Pakistani troops moved to Parvatipur, south of Saidpur after 3 EBR company had gone south to Phulbaria on 2 April.


title: Operation Searchlight

text: On 4 April Bengali commanders held another near Bhatgaon and decided to attack Saidpur, after which 1 EBR and 3 EPR companies (CO captain Ashraf) dug in at Bhushibandar, another EPR company (CO Capt. Anwar) went to Badarganj (west of Parvatipur), and another company stayed at Bhatgaon. 3 EBR companies attacked Parvatipur on the same day, the Pakistani troops and armed Biharis retreated to Saidpur. The significance of the deployment of the Bengali forces in the west, south and north of Saidpur in a semicircle, with the road east to Rangpur open, was not lost to the Pakistani commanders.


title: Operation Searchlight

text: Bengali troops lacked proper communication equipment for co-ordinating an attack on Saidpur and although Indian authorities had been contacted for help, none had been received. Pakistani troops, reinforced through the air after the capture of Lalmunirhut, began to attack Bengali positions from 6 April onwards. Task forces were created from the 26 FF, 48 Punjab and 4 FF battalions, accompanied by a squadron/troop from the 29 cavalry and artillery pieces from the 23rd Field regiment, several Pakistani infantry columns backed by air support begun to attack Bengali positions simultaneously from 4 April.


title: Operation Searchlight

text: Bhushibandar was taken on 5 April, Parvatipur was taken on 6 April, Nilphamari was unsuccessfully attacked the same day. 3 EBR troops attacking Parvatipur from Phulbai on the same day met with bloody repulse and retreated to Phulbari. Pakistani troops attacked Nilphamari on 7 April, Bengali troops left the town the same day and Pakistanis took the town the following day.


title: Operation Searchlight

text: By 10 April, Pakistani troops were poised to attack Bengali positions at T-Junction to the west of Bhushibandar, and areas to the west of Nilphamari and south of Parvatipur. By 27 April the division was secured, and the area north of the Tista river was retaken by Mid May. But in securing the division, 26 FF, the same regiment that had the maximum casualties later on till surrender of Pakistan Army, lost a very valuable resource on 1 May.


title: Operation Searchlight

text: Capt. Mujahid who was at the flank along with three soldiers and his CO, Lt Col Hakeem was attacked by the 3rd EBR. The attack put the team of five in a defensive mode and cross firing started. As a result, Mujahid was brutally injured. A shot went clean through his heart resulting in his Shahadat.


title: Operation Searchlight

text: The overall Searchlight Operation saw mass rape by many Pakistani troops against Bengali women, though the figure of millions was a huge exaggeration by the war's winners given that at its peak the Pakistani garrison numbered no more than seventy thousand soldiers (Qutubuddin). Some Bengali forces also massacred non-Bengali civilians both during and after the war. See Yasmin Saikia's book on rape in the Bangladesh war.


title: Operation Searchlight

text: By the dawn of 10 April, Pakistani forces had gained control of Dhaka, Rangpur-Saidpur, Comilla, Chittagong, and Khulna. Their forces had lost or abandoned Rajshahi, Sylhet, Pabna, Dinajpur, Mymenshing and Kushtia. The vital airfields and all the cantonments remained under Pakistani control, while the rest of the province was unoccupied and outside government control.


title: Operation Searchlight

text: The Bengali resistance had put up an unexpected stiff resistance and had managed to derail the initial Pakistani estimate of pacifying East Pakistan by 10 April. The initial successes were not sustainable as the Bengali forces began to suffer from lack of trained men, officers, co-ordination among scattered troops and lack of central command structure, proper supplies (despite limited aid from BSF).


title: Operation Searchlight

text: The Pakistani army had airlifted the 9th and 16th infantry division to Bangladesh by 10 April and was poised to seize the initiative. Gen. Niazi, who took command of Pakistan forces in Bangladesh on 11 April, obtained a brief from Gen. Raja (the departing GOC) and implemented the following strategy:


title: Operation Searchlight

text: Against this strategy Bengali field commanders opted to go with "holding as much area for as long as possible", The Bengali leadership hoped to keep the Pakistanis confined into the cities, while the Bangladesh government in exile sought diplomatic recognition and the resistance prepared for eventual guerrilla warfare and awaited the expected Indian military intervention.


title: Operation Searchlight

text: Lacking everything except unskilled volunteers, Mukti Bahini fought a conventional battle against an enemy enjoying superiority in number of trained men, firepower, and complete air superiority and played to the strength of Pakistanis. Choosing to attack Bengali forces all over Bangladesh simultaneously, Gen. Niazi concentrated battalion and brigade size forces on company and battalion size defence positions repeatedly, used air strikes and artillery to soften targets, and employed Heli-borne troops to outflank positions and hammered through to reach chosen objectives. Pakistani troop convoys were repeatedly ambushed, but these only delayed the Pakistani advance temporarily.


title: Operation Searchlight

text: By using their superiority of weapons and command of air ruthlessly, with little regard for safety of civilians and often targeting civilian areas to spread terror, the Pakistani army began to fan out of their bases and take over the province. By late April, all the major cities had fallen, by mid May all major towns had been captured and by mid June the battered remnant of Bengali fighters had been driven across the border into India. The Bengali resistance, suffering from a lack of trained men, proper logistics and co-ordination, lost the conventional battle against the Pakistan forces.


title: Operation Searchlight

text: Lt. General Amir Abdullah Khan Niazi had been posted as GOC East Pakistan Command on 11 April 1971, while Gen. Tikka Khan was retained as the governor of the province. General Khadim Raja was relieved from the command of the 14th division, and General Farman continued to serve as advisor on civilian affairs to the governor.


title: Operation Searchlight

text: The Pakistan Army in East Pakistan, after being reinforced by "Operation GREAT FLYIN", was reorganised to run the counterinsurgency operation. The 9th division (HQ Jessore, Maj. Gen. Shaukat Riza commanding) was given the 57th (HQ in Jhenida) and 107th (HQ in Jessore) brigades for controlling Kushtia, Jessore, Khulna, Faridpur, Barisal and Patuakhali districts. The 16th Division (HQ Natore, Maj. Gen. Nazar Hussain Shah commanding) was given the 23rd (HQ Rangpur), 205th (HQ Bogra) and 34th (HQ Nator) brigades and was to control Dinajpur, Rangpur, Bogra, Pabna and Rajshahi districts. The 14th division (HQ Dhaka, Maj. Gen. Rahim Khan) controlled the rest of the province with the 27th (HQ Mymenshingh), 313th (HQ Sylhet), 117th (HQ Comilla) and the 53rd (HQ Chittagong) brigades.


title: Operation Searchlight

text: E.P.C.A.F (East Pakistan Civil Armed Force) was organised to replace the EPR. Commanded by Maj. Gen. Jamshed, this force contained 17 combat wings, 7 sector wings (Sector HQs at Dhaka, Mymeshingh, Jessore, Rajshahi, Dinajpur, Comilla and Chittagong), totalling an estimated 20,000 personnel (West Pakistanies and Biharis), serving under the command of Pakistani army officers. The force was deployed to patrol the border, maintain internal security and support army operations.


title: Operation Searchlight

text: Razakars and Shanti Committees were formed to support the army occupation. Mostly recruited from Bengalis and ex-EPR servicemen, an estimated 40,000 Razakers (against a target of 100,000 recruits) of mixed effectiveness was eventually fielded. Al-Badr and Al-Shams, formed by Jaamat-i-Islami, contributed another 5,000 members each. Pakistan also deployed hundreds of West Pakistani civilians and 5,000 police to support the occupation.


title: Operation Searchlight

text: Admiral Mohammad Shariff, who was Rear-Admiral at that time, and the principle commander of Navy of East Pakistan, released his autobiography, entitled, "Admiral's Diary". In his autobiography, Admiral Shariff provided the account of Operation Searchlight, as he said Shariff concluded, "The initial military success in regaining the law and order situation in East Pakistan in March 1971 was misunderstood as a complete success. In actuality, the law and order situation deteriorated with time, particularly after September of the same year when the population turned increasingly against the army as well as the government".


title: Operation Searchlight

text: The initial resistance, which started on 26 March, functioned without any central command structure. Senior Bengali army officers met at Teliapara in Sylhet on 10 April, and selected Col. (ret) M. A. G. Osmani as commander of Bengali armed forces. On 11 April Osmani designated four sector commanders: Major Zia for the Chittagong area, Major Khaled Mussarraf for Comilla, Major Shafiullah for Sylhet and Major Abu Osman Chowdhury for Jessore area.


title: Operation Searchlight

text: The Bangladesh government in exile was formed by the Awami League leadership on 17 April at Meherpur in Kushtia, which confirmed Col. Osmani as commander of Mukti Bahini (regular armed forces and insurgents) under the authority of Prime Minister Tajuddin Ahmad. Bangladesh Forces Headquarters were set up in Kolkata (Calcutta) with Col. MAG Osmani as commander in chief, Lt. Col. MA Rab as Chief of Staff (based in Agartala, Tripura), and Group Captain AR Khandker as deputy Chief of Staff. The Bengali resistance, after being driven out of Bangladesh, began reorganising to focus on irregular warfare.


title: Operation Searchlight

text: A few thousand people sought refuge during April and May, mostly the resistance. However, as Pakistani army operations spread throughout the province, refugees fleeing to India increased. Ultimately approximately 10 million people would leave East Pakistan, and about 6.7 million were housed in 825 refugee camps.


title: Operation Searchlight

text: An estimated 7.3 million were in West Bengal, and 1.5 million in Tripura. The rest were mainly in Assam and Bihar. The temporary presence of this large foreign population created economic (the cost of feeding, housing and medical care), social (tensions between locals and refugees) and national security (arms falling in the hands of Mizo and Naga rebels) concerns for India.


title: Operation Searchlight

text: The main reason Generals Farman and Yakub had opposed any military action against civilians in East Pakistan was the fear of an Indian attack, which the Pakistan army was woefully unprepared to meet in March 1971. After the crackdown, Tajuddin Ahmad met with Indian Prime Minister Indira Gandhi on 3 April 1971 and asked for all possible aid, by which time the Indian government had already opened East Pakistan border and the BSF was offering limited aid to the Bengali resistance. The issue of direct military intervention was discussed between the Indian military and political leadership in April 1971. The case for intervention was based on the following:


title: Operation Searchlight

text: Although some of the Bengali leadership hoped for and expected an Indian military operation at the earliest, a view also shared by some Indian officers, Indian army eastern command decided in the present condition such a move was inadvisable, and a full attack could only take place after 15 November 1971 at the earliest, only after deliberate and extensive preparations, which was further elaborated to the Indian cabinet by Gen. Sam Manekshaw. Indian leadership decided not to directly "intervene", but chose to get "involved": Eastern command took over responsibility for East Pakistan operations on 29 April, and on 15 May launched Operation Jackpot, a full-fledged operation to recruit, train, arm, equip, supply and advise the Mukti Bahini fighters engaged in guerrilla warfare against the Pakistan armed forces.


title: Operation Searchlight

text: The killings which began on 25 March 1971 and sparked the Bangladesh Liberation War led to the deaths of at least 26,000 people, as admitted by Pakistan (by the Hamoodur Rahman Commission) and as many as 3,000,000 as claimed by Bangladesh (from 1972 to 1975 the first post-war prime minister of Bangladesh, Sheikh Mujibur Rahman, mentioned on several occasions


title: Operation Searchlight

text: that at least three million died). Biharis and non-Bengalis had also suffered in the initial stages of the conflict – houses were looted and some died in Bengali hands.


title: Operation Searchlight

text: A 2018 paper by Christian Gerlach concluded that overall deaths due to the war in East Pakistan slightly exceeded half a million and could not have exceeded 1 million, adding that the majority of death were rural dwellers who died of "hunger, want, and exhaustion" with many deaths occurring in the year following the conflict. Out of 200,000 member of the Awami League the paper states 17,000 were killed with the leaders of the league experiencing a death ratio of 15 to 20 out of 167. The paper also denies based on statistical evidence that there was a coordinated attempt to exterminate the Bengali intelligentsia stating: "if one accepts the data published by the Bangladesh propaganda ministry, 4.2 per cent of all university professors were killed, along with 1.4 per cent of all college teachers, 0.6 per cent of all secondary and primary school teachers, and 0.6 per cent of all teaching personnel. On the basis of the aforementioned Ministry of Education data, 1.2 per cent of all teaching personnel were killed. This is hardly proof of an extermination campaign."


title: Operation Searchlight

text: The genocide also included killing of serving Bengali senior army officers of the rank of Lt. Colonel and above in East Pakistan within the first few days of "Operation Searchlight". The deaths included Col. Badiul Alam, Lt. Col. MA Qadir, Lt. Col. SA Hai, Lt. Col. MR Choudhury, Lt. Col. (Dr.) Ziaur Rahman, Lt. Col. NA M. Jahangir and another dozens of senior majors who were executed by April 1971. Also, around a hundred junior officers and thousands of unfortunate captured Bengali soldiers, including members of the East Pakistan Rifles and Police, serving in East Pakistan were executed. After the defeat of the Pakistan Army, there was a call to try nearly 200 Pakistani POWs for war crimes, but no trials took place.


title: Operation Searchlight

text: The eventual strain of combating the insurgency caused Pakistan to attack India on 3 December 1971, with the objective to stop Indian support for the Mukti Bahini. This attack initiated the Indo-Pakistani War of 1971, which concluded with the unconditional surrender of Pakistan forces on 16 December.


title: Dirty Dancing: Havana Nights

text: Dirty Dancing: Havana Nights (also known as Dirty Dancing 2 or Dirty Dancing 2: Havana Nights) is a 2004 American dance musical romantic drama film directed by Guy Ferland and starring Diego Luna, Romola Garai, Sela Ward, John Slattery, Jonathan Jackson, January Jones, and Mika Boorem. The film is an unrelated prequel/"re-imagining" of the 1987 blockbuster "Dirty Dancing", reusing the same basic plot, but transplanting it from upstate New York to Cuba on the cusp of the Cuban Revolution. Patrick Swayze, star of the original "Dirty Dancing", appears as a dance instructor. It was mostly filmed in Old San Juan, Puerto Rico.


title: Dirty Dancing: Havana Nights

text: In 1958, Katey Miller (Romola Garai), her parents (Sela Ward and John Slattery), and her younger sister Susie (Mika Boorem) arrive in Cuba during the Cuban revolution. A self-described bookworm, Katey is not very happy about having to move to a different country during her senior year of high school, as she had been planning to attend Radcliffe College, although the rest of her family seem extremely pleased to be in Cuba.


title: Dirty Dancing: Havana Nights

text: Meeting several other rich American teenagers down by the pool - including James Phelps (Jonathan Jackson), the son of her father's boss - Katey becomes disgusted when one of the teenagers insults a local waiter when he drops their drinks because Katey accidentally bumped into him. Katey attempts to talk to the waiter—Javier (Diego Luna), who works at the hotel to support his family—because she feels awful about what had occurred, but he is not interested.


title: Dirty Dancing: Havana Nights

text: Katey watches a film of her mother and father dancing and wishes she could dance as well as they did. She and her father dance a bit. The next day in class, Katey is asked to read aloud from the Odyssey - a passage about love and passion. After class, James invites her to a party at the country club the next day and she accepts.


title: Dirty Dancing: Havana Nights

text: While walking home from school, she sees Javier dancing to street music, and he offers to walk her home. They stop to listen to a street band and police show up, stopping Javier while Katey runs away.


title: Dirty Dancing: Havana Nights

text: The next day, Katey tries some of the dance moves she saw. Javier sees her and asks her to come see the real dancers Saturday night, but she says she is already going to the country club. Javier gets upset and leaves. Katey wears one of her maid's dresses to the country club party and impresses James. Katey convinces him to take her to the Cuban nightclub "La Rosa Negra" (The Black Rose) where Javier is dancing with the ladies.


title: Dirty Dancing: Havana Nights

text: Javier dances with Katey while James sits at the bar. Soon he is accosted by Javier's brother, Carlos, who tells him that they will eventually kick the Americans out of Cuba. Javier comes over and argues with his brother. James takes Katey back to the car and assaults her after she refuses to kiss him. She slaps him and runs into the club, and Javier agrees to walk her home.


title: Dirty Dancing: Havana Nights

text: The next day, Katey walks by a dance class. The teacher (Patrick Swayze) asks if anyone wants to enter the big dance contest and then dances with Katey for a bit. She grabs a flyer for the competition.


title: Dirty Dancing: Havana Nights

text: While walking to the pool, James apologizes to Katey and then tells her that Susie saw Javier with her and got him fired. Katey argues with Susie and goes to find Javier. He is now working at a chop shop with Carlos. She asks him to enter the dance contest with her, but he refuses. Meanwhile, it is becoming apparent that Carlos is helping the revolutionaries.


title: Dirty Dancing: Havana Nights

text: The next day, Javier shows up at Katey's school and agrees to enter the dance contest with her. They start teaching each other dance moves and Javier convinces her to "feel the music." They practice all the time, and Katey dances some more with the dance teacher, until it is the night of the dance. Katey and Javier dance with the other couples on the floor and are chosen to go on to the next round.


title: Dirty Dancing: Havana Nights

text: Katey's parents disapprove of her relationship with Javier, but Katey reconciles with them. On the night of the contest's final round, while Katey and Javier are on the dance floor, Javier sees his brother and some revolutionaries disguised as waiters, and the police soon try to arrest them. The contest stops as everyone flees the club, and Javier has to save Carlos from the police. Javier and Carlos talk about how they miss their dad, then they hear that Batista has fled the country and join the celebration.


title: Dirty Dancing: Havana Nights

text: Later, Javier comes to the hotel and finds Katey. He takes her to the beach and they have sex. The next day, Katey's parents tell her they are leaving Cuba and she has one last night with Javier. They go to the Cuban club where they first danced, and the floor is theirs as they are dubbed King and Queen. Katey's family is there to see her, and Katey narrates that she doesn't know when she will see Javier again, but this will not be their last time to dance together.


title: Dirty Dancing: Havana Nights

text: "Havana Nights" is based on an original screenplay by playwright and NPR host Peter Sagal, based on the real life experience of producer JoAnn Jansen, who lived in Cuba as a 15-year-old in 1958–59. Sagal wrote the screenplay, which he titled "Cuba Mine", about a young American woman who witnessed the Cuban revolution and had a romance with a young Cuban revolutionary. The screenplay was to be a serious political romance story, documenting, among other stories, how the Cuban revolution transformed from idealism to terror. It was commissioned in 1992 by Lawrence Bender, who was rising to fame with his production of Quentin Tarantino's "Reservoir Dogs" and "Pulp Fiction". The screenplay was bought by a film studio, which requested several rewrites before deciding not to produce the film. A decade later, Bender decided to make a "Dirty Dancing" sequel, and the film was very loosely adapted from Sagal's script. Not a single line from Sagal's original screenplay appears in the final film and Sagal says that the only remnants of the political theme that existed in his script is a scene wherein some people are executed.


title: Dirty Dancing: Havana Nights

text: Natalie Portman was offered the role of Katey Miller but she turned it down. Ricky Martin was also considered for the role of Javier Suarez. The film was British actress Romola Garai's first Hollywood film and she repeatedly has cited the filming of the movie as being an extremely negative experience which caused her to re-evaluate working in Hollywood. In a 2004 interview with "The Telegraph" she explained that the filmmakers "were obsessed with having someone skinny. I just thought, why didn't they get someone like Kate Bosworth, if that's what they wanted?"


title: Dirty Dancing: Havana Nights

text: In October 2017, in the midst of producer Harvey Weinstein's sexual abuse allegations in Hollywood, Garai later revealed that Weinstein, whose company Miramax was co-producing the film, had required her to meet him alone in a hotel room while he was wearing only a bathrobe to obtain the part: "I had to go to his hotel room in the Savoy, and he answered the door in his bathrobe. I was only 18. I felt violated by it, it has stayed very clearly in my memory."


title: Dirty Dancing: Havana Nights

text: Review aggregator Rotten Tomatoes gives the film a 23% rating based on 108 reviews from critics, with an average rating of 4.2/10. The website provides a brief critical consensus: "Cheesy, unnecessary remake." On Metacritic, the film has a weighted average score of 39 out of 100, based on 32 critics, indicating "generally unfavorable reviews".


title: Dirty Dancing: Havana Nights

text: Robert Denerstein of the "Rocky Mountain News" gave it a D+, saying: "Tries to add Cuban flavor to a familiar plot but comes up with nothing more than a bubbling stew of cliches." Peter Howell of the "Toronto Star" thought it to be "Charmless, clumsy and culturally offensive all at the same time" and merited it 1 out of 5 stars. Wesley Morris of "The Boston Globe" awarded it 2 out of 4 stars, saying: "As you might expect, the movie is as square as a sock hop." Philip Martin of the "Arkansas Democrat-Gazette", who rated it B−, because "aside from the triteness of the dialogue, the mathematical predictability of the script and the muddling of numbskulled politics, DD: HN is a fairly enjoyable experience." According to Louis Hobson of Jam! Magazine, who thought the movie was worth 3.5 out of 5 stars, the main redeeming factor was the choreography: "You may have problems with the obvious, clichéd story, but the dancing is incredible." Philip Wuntch of "The Dallas Morning News" gave the film a C, stating that "both the dance numbers and the personal drama are largely listless."


title: Particle

text: In the physical sciences, a particle (or corpuscule in older texts) is a small localized object to which can be ascribed several physical or chemical properties, such as volume, density, or mass. They vary greatly in size or quantity, from subatomic particles like the electron, to microscopic particles like atoms and molecules, to macroscopic particles like powders and other granular materials. Particles can also be used to create scientific models of even larger objects depending on their density, such as humans moving in a crowd or celestial bodies in motion.


title: Particle

text: The term "particle" is rather general in meaning, and is refined as needed by various scientific fields. Anything that is composed of particles may be referred to as being particulate. However, the noun "particulate" is most frequently used to refer to pollutants in the Earth's atmosphere, which are a suspension of unconnected particles, rather than a connected particle aggregation.


title: Particle

text: The concept of particles is particularly useful when modelling nature, as the full treatment of many phenomena can be complex and also involve difficult computation. It can be used to make simplifying assumptions concerning the processes involved. Francis Sears and Mark Zemansky, in "University Physics", give the example of calculating the landing location and speed of a baseball thrown in the air. They gradually strip the baseball of most of its properties, by first idealizing it as a rigid smooth sphere, then by neglecting rotation, buoyancy and friction, ultimately reducing the problem to the ballistics of a classical point particle. The treatment of large numbers of particles is the realm of statistical physics.


title: Particle

text: The term "particle" is usually applied differently to three classes of sizes. The term "macroscopic particle", usually refers to particles much larger than atoms and molecules. These are usually abstracted as point-like particles, even though they have volumes, shapes, structures, etc. Examples of macroscopic particles would include powder, dust, sand, pieces of debris during a car accident, or even objects as big as the stars of a galaxy.


title: Particle

text: Another type, "microscopic particles" usually refers to particles of sizes ranging from atoms to molecules, such as carbon dioxide, nanoparticles, and colloidal particles. These particles are studied in chemistry, as well as atomic and molecular physics. The smallest of particles are the "subatomic particles", which refer to particles smaller than atoms. These would include particles such as the constituents of atoms – protons, neutrons, and electrons – as well as other types of particles which can only be produced in particle accelerators or cosmic rays. These particles are studied in particle physics.


title: Particle

text: Because of their extremely small size, the study of microscopic and subatomic particles fall in the realm of quantum mechanics. They will exhibit phenomena demonstrated in the particle in a box model, including wave–particle duality, and whether particles can be considered distinct or identical is an important question in many situations.


title: Particle

text: Particles can also be classified according to composition. "Composite particles" refer to particles that have composition – that is particles which are made of other particles. For example, a carbon-14 atom is made of six protons, eight neutrons, and six electrons. By contrast, "elementary particles" (also called "fundamental particles") refer to particles that are not made of other particles. According to our current understanding of the world, only a very small number of these exist, such as leptons, quarks, and gluons. However it is possible that some of these might turn up to be composite particles after all, and merely appear to be elementary for the moment. While composite particles can very often be considered "point-like", elementary particles are truly "punctual".


title: Particle

text: Both elementary (such as muons) and composite particles (such as uranium nuclei), are known to undergo particle decay. Those fail to undergo particle decay are called stable particles, such as the electron or a helium-4 nucleus. The lifetime of stable particles can be either infinite or large enough to hinder attempts to observe such decays. In the latter case, those particles are called "observationally stable". In general, a particle decays from a high-energy state to a lower-energy state by emitting some form of radiation, such as the emission of photons.


title: Particle

text: In computational physics, "N"-body simulations (also called "N"-particle simulations) are simulations of dynamical systems of particles under the influence of certain conditions, such as being subject to gravity. These simulations are very common in cosmology and computational fluid dynamics.


title: Particle

text: "N" refers to the number of particles considered. As simulations with higher "N" are more computationally intensive, systems with large numbers of actual particles will often be approximated to a smaller number of particles, and simulation algorithms need to be optimized through various methods.


title: Particle

text: Colloidal particles are the components of a colloid. A colloid is a substance microscopically dispersed evenly throughout another substance. Such colloidal system can be solid, liquid, or gaseous; as well as continuous or dispersed. The dispersed-phase particles have a diameter of between approximately 5 and 200 nanometers. Soluble particles smaller than this will form a solution as opposed to a colloid. Colloidal systems (also called colloidal solutions or colloidal suspensions) are the subject of interface and colloid science. Suspended solids may be held in a liquid, while solid or liquid particles suspended in a gas together form an aerosol. Particles may also be suspended in the form of atmospheric particulate matter, which may constitute air pollution. Larger particles can similarly form marine debris or space debris. A conglomeration of discrete solid, macroscopic particles may be described as a granular material.


title: Candlemas

text: Candlemas (also spelled Candlemass), also known as the Feast of the Presentation of Jesus Christ, the Feast of the Purification of the Blessed Virgin Mary, or the Feast of the Holy Encounter, is a Christian holiday commemorating the presentation of Jesus at the Temple. It is based upon the account of the presentation of Jesus in Luke 2:22–40. In accordance with Leviticus 12, a woman was to be purified by presenting a lamb as a burnt offering, and either a young pigeon or dove as sin offering, 33 days after a boy's circumcision. It falls on 2 February, which is traditionally the 40th day (postpartum period) of and the conclusion of the Christmas–Epiphany season. While it is customary for Christians in some countries to remove their Christmas decorations on Twelfth Night (Epiphany Eve), those in other Christian countries historically remove them after Candlemas. On Candlemas, many Christians (especially Eastern Orthodox, Roman Catholics, Lutherans, Anglicans and Methodists) also bring their candles to their local church, where they are blessed and then used for the rest of the year; for Christians, these blessed candles serve as a symbol of Jesus Christ, who referred to himself as the Light of the World.


title: Candlemas

text: The Feast of the Presentation is one of the oldest feasts of the Christian church, celebrated since the 4th century AD in Jerusalem. It is mentioned in the pilgrimage of Egeria (381–384), where she confirmed that the celebrations took place in honor of the presentation of Jesus at the Temple.


title: Candlemas

text: XXVI. [The Purification of the Blessed Virgin Mary.] But certainly the Feast of the Purification is celebrated here with the greatest honour. On this day there is a procession to the Anastasis; all go in procession, and all things are done in order with great joy, just as at Easter. All the priests preach, and also the bishop, always treating of that passage of the Gospel where, on the fortieth day, Joseph and Mary brought the Lord into the Temple, and Simeon and Anna the prophetess, the daughter of Famuhel, saw Him, and of the words which they said when they saw the Lord, and of the offerings which the parents presented. And when all things have been celebrated in order as is customary, the sacrament is administered, and so the people are dismissed.


title: Candlemas

text: Christmas was, in the West, celebrated on 25 December from at least the year AD 354 when it was fixed by Pope Liberius. Forty days after 25 December is 2 February. In the Eastern parts of the Roman Empire, Roman consul Justin established the celebration of the Hypapante.


title: Candlemas

text: Pope Gelasius I (492–496) contributed to the spread of the celebration, but did not invent it. It appears that it became important around the time of the Plague of Justinian in 541, before slowly spreading West. The ancient Romans celebrated the Lupercalia in mid-February, in honor of Lupercus, the god of fertility and shepherds. The celebration of Feralia occurred around the same time.


title: Candlemas

text: The Lupercalia has frequently been linked to the presentation of Jesus at the temple, particularly by Cardinal Caesar Baronius in the 16th century especially because of the theme of purification that the two festivals share. However, this is probably inaccurate since Lupercalia was not celebrated in Jerusalem and it was only there that one finds some celebrations of the presentation of Jesus around this date. In fact, Pope Gelasius I had much earlier written a letter to a senator Andromachus, who wanted to reestablish the Lupercalia for the purpose of purification; and the so-called Gelasian Sacramentary mentions the celebration of the Presentation of Jesus, lending support to the conclusion that Gelasius substituted a Christian festival for a pagan one. However the Gelasian Sacramentary shows a strong Gallican influence and was actually compiled between AD 628 and AD 731, so it is possible that the addition of the celebration was not due to Pope Gelasius at all.


title: Candlemas

text: Moreover, when Gelasius addressed Andromachus, he did not try to use his authority, but contented himself to arguing for example that the Lupercalia would no longer have the effect it once had and was incompatible with Christian ideals. This could be interpreted as evidence that he had limited influence on the Roman aristocracy.


title: Candlemas

text: Centuries later, around the year 1392 or 1400, an image of the Virgin Mary that represented this invocation, was found on the seashore by two Guanche shepherds from the island of Tenerife (Canary Islands). After the appearance of the Virgin and its iconographic identification with this biblical event, the festival began to be celebrated with a Marian character in the year 1497, when the conqueror Alonso Fernández de Lugo celebrated the first Candlemas festival dedicated especially to the Virgin Mary, coinciding with the Feast of Purification on 2 February. Before the conquest of Tenerife, the Guanche aborigines celebrated a festivity around the image of the Virgin during the Beñesmen festival in the month of August. This was the harvest party, which marked the beginning of the year. Currently, the feast of the Virgin of Candelaria in the Canary Islands is celebrated in addition to 2 February also on 15 August, the day of the Assumption of the Virgin Mary in the Catholic calendar. For some historians, the celebrations celebrated in honor of the Virgin during the month of August are a syncretized reminiscence of the ancient feasts of the Beñesmen.


title: Candlemas

text: In Swedish and Finnish Lutheran churches, Candlemas is (since 1774) always celebrated on a Sunday, at the earliest on 2 February and at the latest on 8 February, except if this Sunday happens to be the last Sunday before Lent, i.e. Shrove Sunday or Quinquagesima (, ), in which case Candlemas is celebrated one week earlier.


title: Candlemas

text: The Roman church's custom of blessing candles by the clergy found its way to Germany. The German conclusion that if the sun appeared on Candlemas, a hedgehog would cast a shadow, making a "second winter", was the origin for the modern American festival of Groundhog Day, as many of Pennsylvania's early settlers were German.


title: Candlemas

text: In France, Belgium, and Swiss Romandy, Candlemas (, ) is celebrated in the churches on 2 February. It is also considered the day of crêpes. Tradition attributes this custom to Pope Gelasius I, who had pancakes distributed to pilgrims arriving in Rome. Their round shape and golden color, reminiscent of the solar disc, refer to the return of spring after the dark and cold of winter. Tradition also says manger scenes should not be put away until Candlemas, which is the last feast of the Christmas cycle.


title: Candlemas

text: Even today there is a certain symbolism associated with the preparation of the crêpes. A tradition is to flip the crepes in the air with the right hand while holding a gold coin (such as a Louis d'or) or some other coin in the left hand, in order to have prosperity throughout the year. One has to ensure that the pancake lands properly back in the pan.


title: Candlemas

text: In Belgium, it is customary to eat pancakes. All the candles in the house should be lit. It is believed that a clear sky on Candlemas foretells a beneficial year for beekeepers.


title: Candlemas

text: Candlemas used to be an important date "(Lostag)" in the course of the year. It was associated with payment deadlines, fixed employment relationships and the beginning of the "farmer's year". In addition, many customs, weather proverbs, other sayings and rhymes are related to this feast.


title: Candlemas

text: The "farmer's year" began on Candlemas, from then on, depending on the circumstances, field work or the preparations for it can be resumed. On candlemas, the farmer should have had half of the winter food stock for his cattle. Depending on the proverb that one can eat by daylight on Candlemas, the time of in which people worked with artificial light sources, came to an end, as did the time where the women sat in the spinning room.


title: Candlemas

text: On this day, on the other hand, the "servant's year" ended. The servants were paid the remainder of their annual wages and could, or had to, look for a new job or extend their employment with the previous employer for another year, usually with a handshake. The custom of giving the servants a pair of shoes at Candlemas as a reward for further work or for looking for a job was also widespread.


title: Candlemas

text: Being a descendant of an ancient torchlight procession, in Luxembourg the current tradition of "" is a holiday centred around children. In small groups, they roam the streets in the afternoon or evening of 2 February, holding a lighted lantern or homemade wand, singing traditional songs at each house or store, especially "Léiwer Härgottsblieschen". In exchange for the music, they hope to receive a reward in the form of sweets or loose change (formerly bacon, peas, or biscuits).


title: Candlemas

text: This festivity officially finalizes the end of Christmas for Catholics in Puerto Rico; the festivities include a procession where the statue of Nuestra Señora de Candelaria (Our Lady of the Light) is carried on the shoulders. Others follow with lit candles until they reach the church where a mass is celebrated. In the evening, the festivities may continue with a giant bonfire and singing. Some families in the country side burn their dried Christmas trees on this date as a culmination of the holiday season.


title: Candlemas

text: "La Virgen de la Candelaria" or Nuestra Señora de la Candelaria (Our Lady of Light or Our Lady of Candles), popularly called "La Morenita", celebrates the Virgin Mary on the island of Tenerife, one of the Canary Islands (Spain). Our Lady of Light is the patron saint of the Canary Islands.


title: Candlemas

text: The Basilica of Candelaria in Candelaria, Tenerife is considered to be the main church dedicated to the Virgin Mary, and a Basilica minor since 2009. T. Her feast is celebrated on 2 February (Candlemas, "Fiesta de la Candelaria") and 15 August as the patronal feast of the Canary Islands.


title: Candlemas

text: In the Philippines, Our Lady of Candles is also the patroness of Western Visayas region. In Silang, Cavite, her feast is observed locally as a triduum from 1 to 3 February, with 2 February as the actual feast day.


title: Candlemas

text: The Virgin of Candles is the patron saint of Jacaltenango and her feast is marking the end of the Christmas season.


title: Candlemas

text: Dressing and adoration of the Christ Child and family meals with tamales on Candlemas are an important Mexican tradition. The customs of this feast is closely linked to that of the Epiphany, during which the tasting of the "rosca de reyes" (kings cake) will determine who is responsible for organising "La candelaria". Whoever finds the "muñeco" (bean-shaped Christ child) in the cake is named godparent of the Christ child, who will then dress the "niño dios" (an image of the Christ child in the form of a doll) on Candlemas with richly decorated clothes. This Christ child is then brought to the church in order to be blessed. Memories of these events are often passed down from generation to generation in families.


title: Candlemas

text: Following this is the family meal. Whoever draws the bean on Epiphany must also prepare "tamales", which is believed to echo Mexico's pre-Christian past with its offerings of maize. The whole family is invited to this meal (often the same people as for the Rosca at Epiphany), which gives the festival an aspect of family and sharing. These celebrations take place not only in Mexico but also in Mexican communities around the world, for instance in France. It is for this reason that the Mexican tradition also appears in the Inventory of intangible cultural heritage in France.


title: Candlemas

text: The Virgin of Candles is the patron saint of the city of Puno in Peru, held in the first fortnight of February each year. It is one of the largest festivals of culture, music and dancing in Peru. In terms of the number of events related to the cultures of the Quechua and Aymara peoples and of the mestizos of the Altiplano, and also in terms of the number of people directly and indirectly involved in its realization, it stands with the Carnival in Rio de Janeiro and the Carnaval de Oruro in Bolivia as one of the three largest festivals in South America.


title: Candlemas

text: At the core of the festival are performances of music and dance organized by the "Federación Regional de Folklore y Cultura de Puno", consisting of more than 200 dances in more than 150 dance sets. These include "native dances" from the various communities in Puno and sets of dances organized in different quarters of the city, mostly those known as "costume dances". These performances directly involve 40,000 dancers and some 5,000 musicians, and indirectly involve about 25,000 people including directors, sponsors, embroiderers and the makers of masks, clothing, boots, shoes, bells and other items.


title: Electromyography

text: Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG is performed using an instrument called an electromyograph to produce a record called an electromyogram. An electromyograph detects the electric potential generated by muscle cells when these cells are electrically or neurologically activated. The signals can be analyzed to detect abnormalities, activation level, or recruitment order, or to analyze the biomechanics of human or animal movement. Needle EMG is an electrodiagnostic medicine technique commonly used by neurologists. Surface EMG is a non-medical procedure used to assess muscle activation by several professionals, including physiotherapists, kinesiologists and biomedical engineers. In Computer Science, EMG is also used as middleware in gesture recognition towards allowing the input of physical action to a computer as a form of human-computer interaction.


title: Electromyography

text: EMG testing has a variety of clinical and biomedical applications. Needle EMG is used as a diagnostics tool for identifying neuromuscular diseases, or as a research tool for studying kinesiology, and disorders of motor control. EMG signals are sometimes used to guide botulinum toxin or phenol injections into muscles. Surface EMG is used for functional diagnosis and during instrumental motion analysis. EMG signals are also used as a control signal for prosthetic devices such as prosthetic hands, arms and lower limbs.


title: Electromyography

text: An acceleromyograph may be used for neuromuscular monitoring in general anesthesia with neuromuscular-blocking drugs, in order to avoid postoperative residual curarization (PORC).


title: Electromyography

text: Except in the case of some purely primary myopathic conditions EMG is usually performed with another electrodiagnostic medicine test that measures the conducting function of nerves. This is called nerve conduction studies (NCS). Needle EMG and NCSs are typically indicated when there is pain in the limbs, weakness from spinal nerve compression, or concern about some other neurologic injury or disorder. Spinal nerve injury does not cause neck, mid back pain or low back pain, and for this reason, evidence has not shown EMG or NCS to be helpful in diagnosing causes of axial lumbar pain, thoracic pain, or cervical spine pain. Needle EMG may aid with the diagnosis of nerve compression or injury (such as carpal tunnel syndrome), nerve root injury (such as sciatica), and with other problems of the muscles or nerves. Less common medical conditions include amyotrophic lateral sclerosis, myasthenia gravis, and muscular dystrophy.


title: Electromyography

text: The first step before insertion of the needle electrode is skin preparation. This typically involves simply cleaning the skin with an alcohol pad.


title: Electromyography

text: The actual placement of the needle electrode can be difficult and depends on a number of factors, such as specific muscle selection and the size of that muscle. Proper needle EMG placement is very important for accurate representation of the muscle of interest, although EMG is more effective on superficial muscles as it is unable to bypass the action potentials of superficial muscles and detect deeper muscles. Also, the more body fat an individual has, the weaker the EMG signal. When placing the EMG sensor, the ideal location is at the belly of the muscle: the longitudinal midline. The belly of the muscle can also be thought of as in-between the motor point (middle) of the muscle and the tendonus insertion point.


title: Electromyography

text: Cardiac pacemakers and implanted cardiac defibrillators (ICDs) are used increasingly in clinical practice, and no evidence exists indicating that performing routine electrodiagnostic studies on patients with these devices pose a safety hazard. However, there are theoretical concerns that electrical impulses of nerve conduction studies (NCS) could be erroneously sensed by devices and result in unintended inhibition or triggering of output or reprogramming of the device. In general, the closer the stimulation site is to the pacemaker and pacing leads, the greater the chance for inducing a voltage of sufficient amplitude to inhibit the pacemaker. Despite such concerns, no immediate or delayed adverse effects have been reported with routine NCS.


title: Electromyography

text: No known contraindications exist for performing needle EMG or NCS on pregnant patients. Additionally, no complications from these procedures have been reported in the literature. Evoked potential testing, likewise, has not been reported to cause any problems when it is performed during pregnancy.


title: Electromyography

text: Patients with lymphedema or patients at risk for lymphedema are routinely cautioned to avoid percutaneous procedures in the affected extremity, namely venipuncture, to prevent development or worsening of lymphedema or cellulitis. Despite the potential risk, the evidence for such complications subsequent to venipuncture is limited. No published reports exist of cellulitis, infection, or other complications related to EMG performed in the setting of lymphedema or prior lymph node dissection. However, given the unknown risk of cellulitis in patients with lymphedema, reasonable caution should be exercised in performing needle examinations in lymphedematous regions to avoid complications. In patients with gross edema and taut skin, skin puncture by needle electrodes may result in chronic weeping of serous fluid. The potential bacterial media of such serous fluid and the violation of skin integrity may increase the risk of cellulitis. Before proceeding, the physician should weigh the potential risks of performing the study with the need to obtain the information gained.


title: Electromyography

text: There are two kinds of EMG: surface EMG and intramuscular EMG. Surface EMG assesses muscle function by recording muscle activity from the surface above the muscle on the skin. Surface EMG can be recorded by a pair of electrodes or by a more complex array of multiple electrodes. More than one electrode is needed because EMG recordings display the potential difference (voltage difference) between two separate electrodes. Limitations of this approach are the fact that surface electrode recordings are restricted to superficial muscles, are influenced by the depth of the subcutaneous tissue at the site of the recording which can be highly variable depending on the weight of a patient, and cannot reliably discriminate between the discharges of adjacent muscles. Specific electrode placements and functional tests have been developed to minimize this risk, thus providing reliable examinations.


title: Electromyography

text: Intramuscular EMG can be performed using a variety of different types of recording electrodes. The simplest approach is a monopolar needle electrode. This can be a fine wire inserted into a muscle with a surface electrode as a reference; or two fine wires inserted into muscle referenced to each other. Most commonly fine wire recordings are for research or kinesiology studies. Diagnostic monopolar EMG electrodes are typically insulated and stiff enough to penetrate skin, with only the tip exposed using a surface electrode for reference. Needles for injecting therapeutic botulinum toxin or phenol are typically monopolar electrodes that use a surface reference, in this case, however, the metal shaft of a hypodermic needle, insulated so that only the tip is exposed, is used both to record signals and to inject. Slightly more complex in design is the concentric needle electrode. These needles have a fine wire, embedded in a layer of insulation that fills the barrel of a hypodermic needle, that has an exposed shaft, and the shaft serves as the reference electrode. The exposed tip of the fine wire serves as the active electrode. As a result of this configuration, signals tend to be smaller when recorded from a concentric electrode than when recorded from a monopolar electrode and they are more resistant to electrical artifacts from tissue and measurements tend to be somewhat more reliable. However, because the shaft is exposed throughout its length, superficial muscle activity can contaminate the recording of deeper muscles. Single fiber EMG needle electrodes are designed to have very tiny recording areas, and allow for the discharges of individual muscle fibers to be discriminated.


title: Electromyography

text: To perform intramuscular EMG, typically either a monopolar or concentric needle electrode is inserted through the skin into the muscle tissue. The needle is then moved to multiple spots within a relaxed muscle to evaluate both insertional activity and resting activity in the muscle. Normal muscles exhibit a brief burst of muscle fiber activation when stimulated by needle movement, but this rarely lasts more than 100ms. The two most common pathologic types of resting activity in muscle are fasciculation and fibrillation potentials. A fasciculation potential is an involuntary activation of a motor unit within the muscle, sometimes visible with the naked eye as a muscle twitch or by surface electrodes. Fibrillations, however, are detected only by needle EMG, and represent the isolated activation of individual muscle fibers, usually as the result of nerve or muscle disease. Often, fibrillations are triggered by needle movement (insertional activity) and persist for several seconds or more after the movement ceases.


title: Electromyography

text: After assessing resting and insertional activity, the electromyographer assess the activity of muscle during voluntary contraction. The shape, size, and frequency of the resulting electrical signals are judged. Then the electrode is retracted a few millimetres, and again the activity is analyzed. This is repeated, sometimes until data on 10–20 motor units have been collected in order to draw conclusions about motor unit function. Each electrode track gives only a very local picture of the activity of the whole muscle. Because skeletal muscles differ in the inner structure, the electrode has to be placed at various locations to obtain an accurate study.


title: Electromyography

text: Single fiber electromyography assesses the delay between the contractions of individual muscle fibers within a motor unit and is a sensitive test for dysfunction of the neuromuscular junction caused by drugs, poisons, or diseases such as myasthenia gravis. The technique is complicated and typically performed only by individuals with special advanced training.


title: Electromyography

text: Surface EMG is used in a number of settings; for example, in the physiotherapy clinic, muscle activation is monitored using surface EMG and patients have an auditory or visual stimulus to help them know when they are activating the muscle (biofeedback). A review of the literature on surface EMG published in 2008, concluded that surface EMG may be useful to detect the presence of neuromuscular disease (level C rating, class III data), but there are insufficient data to support its utility for distinguishing between neuropathic and myopathic conditions or for the diagnosis of specific neuromuscular diseases. EMGs may be useful for additional study of fatigue associated with post-poliomyelitis syndrome and electromechanical function in myotonic dystrophy (level C rating, class III data). Recently, with the rise of technology in sports, sEMG has become an area of focus for coaches to reduce the incidence of soft tissue injury and improve player performance. Athos, a Silicon Valley startup, has led the way as the only company to have their measurements validated as accurate and reliable compared to a medical grade sEMG system.


title: Electromyography

text: Certain US states limit the performance of needle EMG by nonphysicians. New Jersey declared that it cannot be delegated to a physician's assistant. Michigan has passed legislation saying needle EMG is the practice of medicine. Special training in diagnosing medical diseases with EMG is required only in residency and fellowship programs in neurology, clinical neurophysiology, neuromuscular medicine, and physical medicine and rehabilitation. There are certain subspecialists in otolaryngology who have had selective training in performing EMG of the laryngeal muscles, and subspecialists in urology, obstetrics and gynecology who have had selective training in performing EMG of muscles controlling bowel and bladder function.


title: Electromyography

text: One basic function of EMG is to see how well a muscle can be activated. The most common way that can be determined is by performing a maximal voluntary contraction (MVC) of the muscle that is being tested.


title: Electromyography

text: Muscle force, which is measured mechanically, typically correlates highly with measures of EMG activation of muscle. Most commonly this is assessed with surface electrodes, but it should be recognized that these typically record only from muscle fibers in close proximity to the surface.


title: Electromyography

text: Several analytical methods for determining muscle activation are commonly used depending on the application. The use of mean EMG activation or the peak contraction value is a debated topic. Most studies commonly use the maximal voluntary contraction as a means of analyzing peak force and force generated by target muscles. According to the article "Peak and average rectified EMG measures: Which method of data reduction should be used for assessing core training exercises?", it was concluded that the “average rectified EMG data (ARV) is significantly less variable when measuring the muscle activity of the core musculature compared to the peak EMG variable.” Therefore, these researchers would suggest that “ARV EMG data should be recorded alongside the peak EMG measure when assessing core exercises.” Providing the reader with both sets of data would result in enhanced validity of the study and potentially eradicate the contradictions within the research.


title: Electromyography

text: EMG can also be used for indicating the amount of fatigue in a muscle. The following changes in the EMG signal can signify muscle fatigue: an increase in the mean absolute value of the signal, increase in the amplitude and duration of the muscle action potential and an overall shift to lower frequencies. Monitoring the changes of different frequency changes the most common way of using EMG to determine levels of fatigue. The lower conduction velocities enable the slower motor neurons to remain active.


title: Electromyography

text: A motor unit is defined as one motor neuron and all of the muscle fibers it innervates. When a motor unit fires, the impulse (called an action potential) is carried down the motor neuron to the muscle. The area where the nerve contacts the muscle is called the neuromuscular junction, or the motor end plate. After the action potential is transmitted across the neuromuscular junction, an action potential is elicited in all of the innervated muscle fibers of that particular motor unit. The sum of all this electrical activity is known as a motor unit action potential (MUAP). This electrophysiologic activity from multiple motor units is the signal typically evaluated during an EMG. The composition of the motor unit, the number of muscle fibres per motor unit, the metabolic type of muscle fibres and many other factors affect the shape of the motor unit potentials in the myogram.


title: Electromyography

text: Nerve conduction testing is also often done at the same time as an EMG to diagnose neurological diseases.


title: Electromyography

text: Some patients can find the procedure somewhat painful, whereas others experience only a small amount of discomfort when the needle is inserted. The muscle or muscles being tested may be slightly sore for a day or two after the procedure.


title: Electromyography

text: EMG signals are essentially made up of superimposed motor unit action potentials (MUAPs) from several motor units. For a thorough analysis, the measured EMG signals can be decomposed into their constituent MUAPs. MUAPs from different motor units tend to have different characteristic shapes, while MUAPs recorded by the same electrode from the same motor unit are typically similar. Notably MUAP size and shape depend on where the electrode is located with respect to the fibers and so can appear to be different if the electrode moves position. EMG decomposition is non-trivial, although many methods have been proposed.


title: Electromyography

text: Rectification is the translation of the raw EMG signal to a signal with a single polarity, usually positive. The purpose of rectifying the signal is to ensure the signal does not average to zero, due to the raw EMG signal having positive and negative components. Two types of rectification are used: full-wave and half-wave rectification. Full-wave rectification adds the EMG signal below the baseline to the signal above the baseline to make a conditioned signal that is all positive. If the baseline is zero, this is equivalent to taking the absolute value of the signal. This is the preferred method of rectification because it conserves all of the signal energy for analysis. Half-wave rectification discards the portion of the EMG signal that is below the baseline. In doing so, the average of the data is no longer zero therefore it can be used in statistical analyses.


title: Electromyography

text: Needle EMG used in clinical settings has practical applications such as helping to discover disease. Needle EMG has limitations, however, in that it does involve voluntary activation of muscle, and as such is less informative in patients unwilling or unable to cooperate, children and infants, and in individuals with paralysis. Surface EMG can have limited applications due to inherent problems associated with surface EMG. Adipose tissue (fat) can affect EMG recordings. Studies show that as adipose tissue increased the active muscle directly below the surface decreased. As adipose tissue increased, the amplitude of the surface EMG signal directly above the center of the active muscle decreased. EMG signal recordings are typically more accurate with individuals who have lower body fat, and more compliant skin, such as young people when compared to old. Muscle cross talk occurs when the EMG signal from one muscle interferes with that of another limiting reliability of the signal of the muscle being tested. Surface EMG is limited due to lack of deep muscles reliability. Deep muscles require intramuscular wires that are intrusive and painful in order to achieve an EMG signal. Surface EMG can measure only superficial muscles and even then it is hard to narrow down the signal to a single muscle.


title: Electromyography

text: The electrical source is the muscle membrane potential of about –90 mV. Measured EMG potentials range between less than 50 μV and up to 30 mV, depending on the muscle under observation.


title: Electromyography

text: Typical repetition rate of muscle motor unit firing is about 7–20 Hz, depending on the size of the muscle (eye muscles versus seat (gluteal) muscles), previous axonal damage and other factors. Damage to motor units can be expected at ranges between 450 and 780 mV.


title: Electromyography

text: Muscle tissue at rest is normally electrically inactive. After the electrical activity caused by the irritation of needle insertion subsides, the electromyograph should detect no abnormal spontaneous activity (i.e., a muscle at rest should be electrically silent, with the exception of the area of the neuromuscular junction, which is, under normal circumstances, very spontaneously active). When the muscle is voluntarily contracted, action potentials begin to appear. As the strength of the muscle contraction is increased, more and more muscle fibers produce action potentials. When the muscle is fully contracted, there should appear a disorderly group of action potentials of varying rates and amplitudes (a complete recruitment and interference pattern).


title: Electromyography

text: EMG findings vary with the type of disorder, the duration of the problem, the age of the patient, the degree to which the patient can be cooperative, the type of needle electrode used to study the patient, and sampling error in terms of the number of areas studied within a single muscle and the number of muscles studied overall. Interpreting EMG findings is usually best done by an individual informed by a focused history and physical examination of the patient, and in conjunction with the results of other relevant diagnostic studies performed including most importantly, nerve conduction studies, but also, where appropriate, imaging studies such as MRI and ultrasound, muscle and nerve biopsy, muscle enzymes, and serologic studies.


title: Electromyography

text: Abnormal results may be caused by the following medical conditions (please note this is not an exhaustive list of conditions that can result in abnormal EMG studies):


title: Electromyography

text: The first documented experiments dealing with EMG started with Francesco Redi’s works in 1666. Redi discovered a highly specialized muscle of the electric ray fish (Electric Eel) generated electricity. By 1773, Walsh had been able to demonstrate that the eel fish’s muscle tissue could generate a spark of electricity. In 1792, a publication entitled "De Viribus Electricitatis in Motu Musculari Commentarius" appeared, written by Luigi Galvani, in which the author demonstrated that electricity could initiate muscle contraction. Six decades later, in 1849, Emil du Bois-Reymond discovered that it was also possible to record electrical activity during a voluntary muscle contraction. The first actual recording of this activity was made by Marey in 1890, who also introduced the term electromyography. In 1922, Gasser and Erlanger used an oscilloscope to show the electrical signals from muscles. Because of the stochastic nature of the myoelectric signal, only rough information could be obtained from its observation. The capability of detecting electromyographic signals improved steadily from the 1930s through the 1950s, and researchers began to use improved electrodes more widely for the study of muscles. The AANEM was formed in 1953 as one of several currently active medical societies with a special interest in advancing the science and clinical use of the technique. Clinical use of surface EMG (sEMG) for the treatment of more specific disorders began in the 1960s. Hardyck and his researchers were the first (1966) practitioners to use sEMG. In the early 1980s, Cram and Steger introduced a clinical method for scanning a variety of muscles using an EMG sensing device.


title: Electromyography

text: Research began at the Mayo Clinic in Rochester, Minnesota under the guidance of Dr Edward H. Lambert, MD, PhD (1915–2003) in the early 1950s. Dr Lambert, known as the "Father of EMG," with the assistance of his Research Technician, Ervin L Schmidt, a self taught electrical engineer, developed a machine that could be moved from the EMG Lab, and was relatively easy to use. As oscilloscopes had no “store” or “print” features at the time, a Polaroid camera was affixed to the front on a hinge. It was synchronized to photo the scan. Fellows studying at Mayo soon learned that this was a tool they wanted, too. As Mayo has no interest in marketing their inventions, Mr. Schmidt went on to continue to develop them in his basement for decades, selling them under the name ErMel Inc.


title: Electromyography

text: It was not until the middle of the 1980s that integration techniques in electrodes had sufficiently advanced to allow batch production of the required small and lightweight instrumentation and amplifiers. At present, a number of suitable amplifiers are commercially available. In the early 1980s, cables that produced signals in the desired microvolt range became available. Recent research has resulted in a better understanding of the properties of surface EMG recording. Surface electromyography is increasingly used for recording from superficial muscles in clinical or kinesiological protocols, where intramuscular electrodes are used for investigating deep muscles or localized muscle activity.


title: Electromyography

text: There are many applications for the use of EMG. EMG is used clinically for the diagnosis of neurological and neuromuscular problems. It is used diagnostically by gait laboratories and by clinicians trained in the use of biofeedback or ergonomic assessment. EMG is also used in many types of research laboratories, including those involved in biomechanics, motor control, neuromuscular physiology, movement disorders, postural control, and physical therapy.


title: Electromyography

text: EMG can be used to sense isometric muscular activity where no movement is produced. This enables definition of a class of subtle motionless gestures to control interfaces without being noticed and without disrupting the surrounding environment. These signals can be used to control a prosthesis or as a control signal for an electronic device such as a mobile phone or PDA .


title: Electromyography

text: EMG signals have been targeted as control for flight systems. The Human Senses Group at the NASA Ames Research Center at Moffett Field, CA seeks to advance man-machine interfaces by directly connecting a person to a computer. In this project, an EMG signal is used to substitute for mechanical joysticks and keyboards. EMG has also been used in research towards a "wearable cockpit," which employs EMG-based gestures to manipulate switches and control sticks necessary for flight in conjunction with a goggle-based display.


title: Electromyography

text: Unvoiced or silent speech recognition recognizes speech by observing the EMG activity of muscles associated with speech. It is targeted for use in noisy environments, and may be helpful for people without vocal cords, with aphasia, with dysphonia, and more.


title: Electromyography

text: EMG has also been used as a control signal for computers and other devices. An interface device based on an EMG Switch can be used to control moving objects, such as mobile robots or an electric wheelchair. This may be helpful for individuals that cannot operate a joystick-controlled wheelchair. Surface EMG recordings may also be a suitable control signal for some interactive video games.


title: Electromyography

text: In 1999 an EMG program called Echidna was used to enable a man with locked-in syndrome to send a message to a computer. That program, now called NeuroSwitch, developed by Control Bionics enables people with severe disabilities to communicate by text, email, SMS, computer-generated voice and to control computer games and programs, and - through the internet - Anybots telepresence robots.


title: Electromyography

text: A joint project involving Microsoft, the University of Washington in Seattle, and the University of Toronto in Canada has explored using muscle signals from hand gestures as an interface device. A patent based on this research was submitted on June 26, 2008.


title: Electromyography

text: In 2016 a startup called Emteq Labs launched a virtual reality headset with embedded EMG sensors for measuring facial expressions. In September 2019 Facebook bought a startup called CTRL-labs that was working on EMG


title: Nishapur

text: Nishapur or officially Romanized as Neyshabur (; from Middle Persian ""New-Shapuhr"", meaning: "The New City of Shapur", "The Fair Shapur", or "The Perfect built of Shapur") is the second-largest city of Razavi Khorasan Province in the Northeast of Iran. Nishapur is situated in a fertile plain at the foot of Binalud Mountain Range and has been the historic capital of the Western Quarter of Greater Khorasan, the historic capital of the 9th-century Tahirid dynasty, the initial capital of the 11th-century Seljuk Empire, and is currently the capital city of Nishapur County and a historic Silk Road city of cultural and economic importance in Iran and the region of Greater Khorasan.


title: Nishapur

text: As of 2016, its central city population was estimated to be 264,180 and its county's population was estimated to be 448,125 making it the third most-populous city in the eastern provinces of Iran. Nearby are turquoise mines that have supplied the world with turquoise of the finest and the highest quality for at least two millennia.


title: Nishapur

text: The city was founded in the 3rd century by Shapur I as a capital city of Sasanian satrapy known as Abarshahr or Nishapur. Nishapur later became the capital of Tahirid dynasty and was reformed by Abdullah Tahir in 830, and was later selected as the capital of Seljuk dynasty by Tughril in 1037. From the Abbasid era to the Mongol invasion of Khwarezmia and Eastern Iran, the city evolved into a significant cultural, commercial, and intellectual center within the Islamic world. Nishapur, along with Merv, Herat and Balkh, was one of the four great cities of Greater Khorasan and one of the greatest cities of the Old World in the Islamic Golden Age with strategic importance, a seat of governmental power in the eastern section of caliphates, a dwelling place for diverse ethnic and religious groups and a trading stop on commercial routes from Transoxiana, China, Iraq and Egypt.


title: Nishapur

text: Nishapur reached the height of its prosperity under the Samanids in the 10th century but was destroyed and most of its population was slaughtered by the Mongols in 1221. This massacre, combined with subsequent earthquakes and other invasions, is believed to have destroyed the city several times. Unlike its near neighbor Merv, Nishapur managed to recover from these cataclysmic events, and survive until the present day as an active modern city and county in tourism, agriculture, health care, industrial production and commerce in Razavi Khorasan Province of Iran; however, many of its older and historical archeological remains are left to be uncovered.


title: Nishapur

text: The modern city of Nishapur is composed of three main administrative areas/districts (Persian: منطقه های شهر نیشابور) and is surrounded by many villages which are joining in to the urban area and structure of the city. The Area/district 1 of the city comprises the newer urban developments (initiated mostly in the 1980s and the 1990s) made to the north of the Road 44 and is home to the most of the main higher educational institutions of Nishapur such as the University of Neyshabur and the IAUN. The Area/district 2 of the city comprises the downtown of the city and the older and more historic urban structures situated on the south of the Road 44. It is home to some of the main tourists attractions of the city such as the National Garden of Nishapur and the Khanate Mansion of Amin Islami. The Area/district 3 of the city is home to the ruins and the remains of the ancient city of Nishapur destroyed by Mongols in the Middle Ages and is located on the south and the southeast of the city. The third district of the city is a national and registered protected archeological area by law and any unauthorized archeological excavation is considered illegal. This district is also home to the burial and historical monuments (some are shown on the city infobox) of most of the renowned persons of the city throughout history such as the Mausoleum of Omar Khayyám and the Mausoleum of Attar of Nishapur. The third district is also used as one of the main touristic hotspots of the city.


title: Nishapur

text: Many of this city's archeological discoveries are held and shown to the public in the Metropolitan Museum of Art in New York City, the British Museum in London, the National Museum of Iran in Tehran, other international museums and the museums of the city of Nishapur. The city of Nishapur is also a member of international organizations such as the LHC and the ICCN UNESCO.


title: Nishapur

text: History of Nishapur has been intermingled with myths and different historical narratives. According to different mythological and historical narratives, the city was founded 7500 years ago during the reign of mythical line of primordial kings known as the Pishdadian dynasty. According to Arthur Christensen, Nishapur was founded in the year 260 A.D. Nishapur was founded by the Sasanian emperor Shapur II () during the last years of his rule, as demonstrated by new archaeological findings. In the 9th century, Nishapur became the capital of the Tahirid dynasty, and by the 10th century, was under Samanid rule. The city became an important and prosperous administrative center under the Samanids. In 1037, it was conquered by the Seljuks. Despite being sacked by the Oghuz Turks in 1153 and suffering several earthquakes, Nishapur continued as an important urban center until it was destroyed again by Genghis Khan and the Mongols in 1221.


title: Nishapur

text: Little archaeology has been done on this vast and complicated site. George Curzon remarked that Nishapur had been destroyed and rebuilt more times than any other city in history, an evocative statement whether or not it is statistically true. The Metropolitan Museum of Art undertook excavations from 1935 that were interrupted in 1940. Searching largely for museum-worthy trophies that they shared with the government of the Shah, the Metropolitan's publications were limited to its own Nishapur ceramics. The site of Nishapur has been ransacked for half a century since World War II, to feed the international market demand for early Islamic works of art.


title: Nishapur

text: Shadiyakh ("Palace of Happiness") was one of the main palaces of old Nishapur up to the 9th century AD, which became more important and populated after that. Some notable people like Attar lived there. Attar's tomb is nowadays in that area. This palace was perhaps completely ruined in the 13th century.


title: Nishapur

text: Nishapur occupies an important strategic position astride the old Silk Road that linked Anatolia and the Mediterranean Sea with China. On the Silk Road, Nishapur has often defined the flexible frontier between the Iranian plateau and Central Asia. The town derived its name from its reputed founder, the Sassanian king Shapur I, who is said to have established it in the third century CE. Nearby are the turquoise mines that supplied the world with turquoise for at least two millennia.


title: Nishapur

text: It became an important town in the Greater Khorasan region but subsequently declined in significance until a revival in its fortunes in the 9th century under the Tahirid dynasty, when the glazed ceramics of Nishapur formed an important item of trade to the west. For a time Nishapur rivaled Baghdad or Cairo: Toghrül, the first ruler of the Seljuk dynasty, made Nishapur his residence in 1037 and proclaimed himself sultan there, but it declined thereafter, as Seljuk fortunes were concentrated in the west. In the year 1000 CE, it was among the ten largest cities on earth.


title: Nishapur

text: In 1221, after the death of Tokuchar, the husband of Genghis Khan's daughter, the entire city of Nishapur was destroyed by the Mongols over the course of 10 days. Genghis Khan's daughter requested the death of every resident of the city as vengeance for her husband's death. In order to become sure that no wounded would survive the massacre, Khan's troops killed and beheaded most of the population of the city and their skulls were reputedly piled in pyramids by the Mongols. Women, Infants, children, and even cats and dogs were among the beheaded. After the massacre a much smaller settlement was established just north of the ancient town, and the once bustling metropolis lay underground—until a team of excavators from the Metropolitan Museum of Art arrived in the mid-20th century. They worked at Nishapur between 1935 and 1940, returning for a final season in the winter of 1947–48. What remains of old Nishapur is a 3500-hectare "Kohandejh (Persian: کهن دژ)" area, south of the current city of Nishapur.


title: Nishapur

text: After the fall of Nishapur in 1221 by the Mongols, the structures of the city were weakened and the agricultural output of the city was reduced. Mahmud Ghazan and Abu Sa'id Bahadur Khan tried to make the city flourish again and the city's population grew once more and some of the villages around the city were improved and rebuilt. Hamdallah Mustawfi had visited the city of Nishapur in the Year 1339 or 1340. During this era, the ambassador of Henry III of Castile, Ruy González de Clavijo reached Nishapur and according to him, Nishapur had become a highly productive agricultural center with 40 non-stop working mills along the <nowiki>"</nowiki>Abe Bostan<nowiki>"</nowiki> (Mir Ab River of Nishapur). The current position of the city was formed during this era and on the North West of the older position of the city which is now home to the Mausoleum of Attar of Nishapur and Shadiyakh Archeological Site and other remains of the old position of the city (the old position of the city is also now a protected archeological site by law though it is endangered). Mausoleum of Attar of Nishapur and the Jame mosque of Nishapur (congregational mosque of the city) are among the examples of the buildings built during this era in Nishapur. Many poets, scholars and renowned historical figures of the city and the wider region of Abarshahr ( one of the main four regions of Greater Khorasan with the city capitals of Nishapur, Merv, Herat and Balkh) were also born in this period.


title: Nishapur

text: Due to a conflict between the supporters of the Mohammad Khodabanda, the Safavid Shah of Persia, and his son Abbas the Great. In 1581 the castle of Nishapur went under siege. This siege became one of the events that helped the Abbas the Great to become the Ruler of Greater Khorasan and later the Shah of Persia in the Safavid Empire. In 1592 Abbas the Great took back the control of Nishapur from the Shaybanids. Shah Abbasi Caravanseri of Nishapur was also built during his reign and later on, he left his two epigraphs on Jame Mosque of Nishapur on the Ramadan of October 1612.


title: Nishapur

text: Saadat Ali Khan I Nishapuri, Nawab of Awadh (the ruler who governed the state of Awadh of India), was also born in this period in an influential family in Nishapur.


title: Nishapur

text: After the death of Nader Shah Afshar in 1747, the area became an independent khanate under the reign of the Bayat chieftains. In 1751 Ahmad Shah Durrani captured Nishapur with the support of heavy artillery and imposed Shahrokh Shah as the ruler (Shah) of the western part of Greater Khorasan.


title: Nishapur

text: The city was conquered in 1800 by the Qajars. In 1828, the city came under the influence of the Zafaranlu Confederacy but was given back to the Qajars in 1829. During the Revolt of Hasan Khan Salar, the city was an isolated outpost of Qajar rule led by Imamverdi Khan Bayat when most of Khorasan was under the wrath of Hasan Khan Salar. On March 21, 1849, Qajar forces entered Nishapur.


title: Nishapur

text: The reconstruction of the Mausoleum of Omar Khayyam in Nishapur was commissioned by Reza Shah. Omar's previous tomb was separated from his tomb, and a white marble monument (Current Mausoleum), designed by the Iranian architect Hooshang Seyhoun, was erected over it. This mausoleum became one of the main symbols of the city and one of the known works of the modern Persian architecture. The influence of the architectural design of this mausoleum is visible on the coat of arms of the University of Neyshabur, Neyshabur University of Medical Sciences (NUMS) and other public, civil and private organizations of the city. The construction of the new mausoleum was completed in the year 1963. The Tomb of Kamal-ol Molk was also built in Nishapur and designed by Seyhoun. The Wooden Mosque of Neyshabur was also built in the year 2000.


title: Nishapur

text: The Second Asia-Pacific Jamboree was held at Baghrud Scots Park of Nishapur in preparation for The 15th World Scout Jamboree which was scheduled to be held 15–23 July 1979 in Nishapur but due to the political uncertainty of the Iranian Revolution in the country, the event was cancelled.


title: Nishapur

text: On February 18, 2004, in the Nishapur train disaster, a train carrying flammable goods derailed and caught fire near the town. Five hours later, during fire fighting and rescue work, a massive explosion destroyed the train and many nearby buildings. Around 300 people were said to have been killed, mainly fire and rescue workers but also the local governor and mayor and the heads of the fire and rail services. This disaster has become known as one of the worst railway industry disasters of the world.


title: Nishapur

text: During the 10th century, Nishapur was a thriving economic center home to many religious scholars and artists. Nishapur was located along the Silk Road. An influential trade route connecting China to the Mediterranean Sea. It was a center for cotton, silk, textile and ceramic production. In efforts to uncover the history of life in this city, the Metropolitan Museum of Art put together an excavation team composed of researchers Joseph Upton, Walter Hauser and Charles Wilkinson. From 1935 to 1940, the team worked to rediscover the ancient city. They were authorized to work under the conditions that half of the material found must be shared with the Iran Bastan Museum in Tehran. Along with pottery, excavators uncovered glass, metalwork, coins and decorated wall fragments. Over the years of excavations, thousands of items were uncovered which provided information on local artistic traditions.


title: Nishapur

text: The most elaborate architectural excavation took place at the site called Tepe Madraseh. This massive complex had been thoughtfully planned and embellished with many decorative elements. Plaster panels had been carved and painted, along with walls, brickwork and glazed ceramic tiles. A madraseh is a place for religious learning. Such sites have peaked the interest of scholars for centuries for their function and architectural designs. Like most Islamic architecture the entire complex of Tepe Madaseh was oriented to face Mecca. The bricks used to construct most of the structures had been dried in the kilns located on the outskirts of the complex.


title: Nishapur

text: Nishapur during the Islamic Golden Age, especially the 9th and 10th centuries, was one of the great centers of pottery and related arts. Most of the Ceramic artifacts discovered in Nishapur are preserved in the Metropolitan Museum of Art and Museums in Nishapur, Tehran and Mashhad. Ceramics produced at Nishapur showed links with Sassanid art and Central Asian. Nowadays there are 4 Pottery workshops in Nishapur.


title: Nishapur

text: "Although the decoration of pottery may only tell us a little about the people who used it, the form of a vessel is directly related to its function". The Pottery of Nishapur incorporated strong colored slips and bold patterns. Common decoration included geometric and vegetal patterns, calligraphy, figures and animals. The ceramic pieces uncovered at Nishapur consisted mainly of vessels and utilitarian wares. Objects such as plates, bowls, bottles, jars, pitchers, coin banks and even a toy hen were found. One decorative technique specifically utilized by Nishapur potters was the refined use of chattering, a rippled texture achieved when trimming a vessel on the wheel. The polychrome ware of Nishapur indicates the significant advances in glaze technology that were being discovered during the 10th century. It also indicates how an objects aesthetic became an important part of the piece as a whole.


title: Nishapur

text: Weaving carpets and rugs common in the more than 470 villages in Nishapur County, the most important carpet Workshop located in the villages of: Shafi' Abad, Garineh, Darrud, Baghshan, Kharv, Bozghan, Sayyed Abad, Sar Chah, Suleymani, Sultan Abad and Eshgh Abad. Nishapur Carpet workshops weaved the biggest Carpets in the world, like carpets of: Sheikh Zayed Mosque, Sultan Qaboos Grand Mosque, Armenian Presidential Palace, Embassy of Finland in Tehran, Mohammed Al-Ameen Mosque in Oman.


title: Nishapur

text: Modern art of carpet in Nishapur began in 1946 after inauguration of a carpet-weaving workshop in a caravansary.


title: Nishapur

text: For at least 2,000 years, Iran, known before as Persia, has remained an important source of turquoise, which was named by Iranians initially "pirouzeh" meaning "victory" and later after Arab invasion "firouzeh". As an important source of turquoise, Nishapur has been sometimes referred to as the "city of turquoise" throughout history. In Iranian architecture, the blue turquoise was used to cover the domes of the Iranian palaces because its intense blue color was also a symbol of heaven on earth.


title: Nishapur

text: This deposit, which is blue naturally, and turns green when heated due to dehydration, is restricted to a mine-riddled region in Nishapur, the mountain peak of Ali-mersai, which is tens of kilometers from Mashhad, the capital of Khorasan province, Iran. Nishapur's turquoise has been sold as souvenirs and jewelry in Nishapur and Mashhad. A weathered and broken trachyte is host to the turquoise, which is found both "in situ" between layers of limonite and sandstone, and amongst the scree at the mountain's base. These workings, together with those of the Sinai Peninsula, are the oldest known.


title: Nishapur

text: A selection of historical buildings and monuments of the city is shown in the city info box on the top of this article, and on the gallery below:


title: Nishapur

text: Most people speak Persian and are monolingual, however, there are several private foreign language-teaching institutions in the city that teach English and other languages.


title: Nishapur

text: Nishapur has been of importance in Iranian mythology. Before the Islamization of Iran, Zoroastrianism had been the major religion of Nishapur. Rivand (one of the ancient names of Nishapur) has been mentioned in Avesta and subsequently in Shahnameh. Adur Burzen-Mihr a Zoroastrian fire temple of the highest grade was situated in Rivand Mountains (Binalud mountains) of Nishapur and the lake Rivand of Nishapur was built due to a fight between Ahriman and water (probably by water it was meant Anahita in the Persian text of the Persian wiki). Also, according to Hakim Nishapuri, was built by Seth on a giant round soft (flat) stone There are also signs of the influence of (a street in Nishapur has been called and is still called Masih and also a village on the south of the city was called Masih Abad). After the rise of Islam however, the people living in and near the city of Neyshabur became Muslims. Nishapur and its people have also had an influence on Sufism (an Islamic mystic practice). Poets and Sufis such as Attar of Nishapur who had been born in this city had had a profound influence on Islamic mysticism. In the 10th century, Nishapur had been one of the centers of Ismaili missionary spread in Iran and Greater Khorasan. Most of the Ismailis of Nishapur now live in Dizbad and some in the main city itself. Jama'at Khana Dizbad is the most important Ismaili center in Nishapur today. From the third to the sixth of Hejri Ghamari, Nishapur was one of the centers of Sufism. Most Sufis and Sufi elders in Nishapur were Sunnis and followers of the Shafi'i school.


title: Nishapur

text: There are several high schools in the city and the county. The most famous and the oldest of which is Omar Khayyam High School.


title: Nishapur

text: The University of Neyshabur, Neyshabur University of Medical Sciences (NUMS), the Islamic Azad University of Neyshabur (IAUN), the Payame Noor University of Neyshabur and the Technical and Vocational University of Neyshabur, are the main universities of the city along with several other public and private technical, vocational, and part-time colleges and schools.


title: Nishapur

text: Enghelab Sports Complex is an indoor arena in Nishapur. The arena houses Nishapur's basketball, volleyball, and futsal teams. Nishapur has one professional football team, Jahan Electric Nishapur, that competes in the Razavi Khorasan's Provincial Leagues.


title: Nishapur

text: Road 44, a major national expressway that connects the two major cities of Tehran and Mashhad, is connected to the city of Nishapur and it passes through it.


title: Nishapur

text: Nishapur is connected to the Trans-Iranian Railway System which is a UNESCO world heritage. The Nishapur train station became operational during the reign of Mohammad Reza Pahlavi and it is located on the southern part of the city.


title: Nishapur

text: On 18 February 2004, runaway train wagons crashed into the village of Khayyam near Nishapur. This accident caused several major explosions and it kill over 300. The entire village of Khayyam was destroyed due to the explosions.


title: Nishapur

text: The intercity bus terminal of the city is located at the eastern part of the city close to the road 44. Several public bus lines and stations are also active within the city.


title: Nishapur

text: Currently there is only one airport near the north of the city that is only authorized to be used for gliders and small aircraft however, there are plans for building a proper airport near the south of the city of Nishapur.


title: Nishapur

text: The economy of Nishapur is diverse and it is based on several industries like Agriculture, Industrial parks, mining, tourism, health-care, retailing, banking etc.


title: Nishapur

text: Many agricultural products such as saffron, cotton, herbs, plums, walnut, wheat, corn, apples, cherries and pistachio are exported from the county of Nishapur. The city is also a dairy and sugar exporter.


title: Nishapur

text: Most of the water supply of the city is provided from the Binalud Mountain Range's mostly seasonal rivers, qanats, dams and modern wells.


title: Nishapur

text: The electrical power supply of the city is provided from Neyshabur Combined Cycle Power Plant and Binalood Wind Farm. The excessive electrical energy of the city is mostly exported from the city's public power grid.


title: Nishapur

text: Khorasan Steel Complex and two main industrial parks called the Khayyam Industrial Park and the Attar Industrial Park are near the city of Nishapur. Many industrial products such as sugar, cooking oils and gas heaters are exported from the city and its county.


title: Nishapur

text: Several hotels, ecolodges, resorts, parks, tourist hot-spots, restaurants, museums, a planetarium, cultural centers, mausoleums, religious pilgrimage sites and historic mosques are in and near the city. The tourism industry of the city has a lot of protentional but it needs further development.


title: Nishapur

text: There are two active hospitals (Hakim Hospital and 22 Bahman Hospital) in the city of Nishapur and a third one is also currently under construction.


title: Nishapur

text: Nishapur is located at an elevation of 1213 meters on a wide fertile plain at the southwestern foot of the Binalud Mountain range in northcentral Razavi Khorasan Province. The city is connected by both railways and highways to Mashhad, Tehran and the South Khorasan Province. Among its agricultural products are cereals and cotton. Pottery making and carpet weaving are among its important handicrafts.


title: Nishapur

text: Throughout the Middle Ages, Nishpaur had been praised by many due to its many gardens and its healthy climate in Khorasan. Ibn Hawqal has commented the following about the weather and the climate of this city at that time:Throughout all of Khorasan, no such companion as enriched with the health of the air, quantity and the vastness of its mansions can be found.In the same cited work, Hakim Nishapuri praises Nishapur with many nicknames such as " " and compares and claims that the weather and climate (or air Persian: هوا) of Nishapur was better and more healthier (according to him, cholera and other such diseases and disasters could not be found in Nishapur) than many neighboring regions such as Sistan (due to its winds), Indus valley (or سند in Persian) and Hindustan (due to their severe hotness), Khwarazm and Turkestan (due to their coldness) and Merv (due to presence of many insects).


title: Nishapur

text: Nishapur generally has a warm and semi-dry climate called <nowiki>"</nowiki>central Iranian plateau climate<nowiki>"</nowiki>. Precipitation mostly happens in spring and winter. Nishapur is situated on a relatively higher elevation (1250 meters) than its neighboring cities such Sabzevar and Mashhad hence the weather is milder and better than these cities.