title: Blood bank

text: Carl Walter and W.P. Murphy Jr. introduced the plastic bag for blood collection in 1950. Replacing breakable glass bottles with durable plastic bags allowed for the evolution of a collection system capable of safe and easy preparation of multiple blood components from a single unit of whole blood.


title: Blood bank

text: Further extending the shelf life of stored blood up to 42 days was an anticoagulant preservative, CPDA-1, introduced in 1979, which increased the blood supply and facilitated resource-sharing among blood banks.


title: Blood bank

text: In the U.S., certain standards are set for the collection and processing of each blood product. "Whole blood" (WB) is the proper name for one defined product, specifically unseparated venous blood with an approved preservative added. Most blood for transfusion is collected as whole blood. Autologous donations are sometimes transfused without further modification, however whole blood is typically separated (via centrifugation) into its components, with red blood cells (RBC) in solution being the most commonly used product. Units of WB and RBC are both kept refrigerated at , with maximum permitted storage periods (shelf lives) of 35 and 42 days respectively. RBC units can also be frozen when buffered with glycerol, but this is an expensive and time-consuming process, and is rarely done. Frozen red cells are given an expiration date of up to ten years and are stored at .


title: Blood bank

text: The less-dense blood plasma is made into a variety of frozen components, and is labeled differently based on when it was frozen and what the intended use of the product is. If the plasma is frozen promptly and is intended for transfusion, it is typically labeled as fresh frozen plasma. If it is intended to be made into other products, it is typically labeled as recovered plasma or plasma for fractionation. Cryoprecipitate can be made from other plasma components. These components must be stored at or colder, but are typically stored at . The layer between the red cells and the plasma is referred to as the buffy coat and is sometimes removed to make platelets for transfusion. Platelets are typically pooled before transfusion and have a shelf life of 5 to 7 days, or 3 days once the facility that collected them has completed their tests. Platelets are stored at room temperature () and must be rocked/agitated. Since they are stored at room temperature in nutritive solutions, they are at relatively high risk for growing bacteria.


title: Blood bank

text: Some blood banks also collect products by apheresis. The most common component collected is plasma via plasmapheresis, but red blood cells and platelets can be collected by similar methods. These products generally have the same shelf life and storage conditions as their conventionally-produced counterparts.


title: Blood bank

text: Donors are sometimes paid; in the U.S. and Europe, most blood "for transfusion" is collected from volunteers while plasma for other purposes may be from paid donors.


title: Blood bank

text: Most collection facilities as well as hospital blood banks also perform testing to determine the blood type of patients and to identify compatible blood products, along with a battery of tests (e.g. disease) and treatments (e.g. leukocyte filtration) to ensure or enhance quality. The increasingly recognized problem of inadequate efficacy of transfusion is also raising the profile of RBC viability and quality. Notably, U.S. hospitals spend more on dealing with the consequences of transfusion-related complications than on the combined costs of buying, testing/treating, and transfusing their blood.


title: Blood bank

text: Routine blood storage is 42 days or 6 weeks for stored packed "red blood cells" (also called "StRBC" or "pRBC"), by far the most commonly transfused blood product, and involves refrigeration but usually not freezing. There has been increasing controversy about whether a given product unit's age is a factor in transfusion efficacy, specifically on whether "older" blood directly or indirectly increases risks of complications. Studies have not been consistent on answering this question, with some showing that older blood is indeed less effective but with others showing no such difference; nevertheless, as storage time remains the only available way to estimate quality status or loss, a "first-in-first-out" inventory management approach is standard presently. It is also important to consider that there is large "variability" in storage results for different donors, which combined with limited available quality testing, poses challenges to clinicians and regulators seeking reliable indicators of quality for blood products and storage systems.


title: Blood bank

text: Transfusions of "platelets" are comparatively far less numerous, but they present unique storage/management issues. Platelets may only be stored for 7 days, due largely to their greater potential for contamination, which is in turn due largely to a higher storage temperature.


title: Blood bank

text: Insufficient transfusion efficacy can result from red blood cell (RBC) blood product units damaged by so-called "storage lesion"—a set of biochemical and biomechanical changes which occur during storage. With red cells, this can decrease viability and ability for tissue oxygenation. Although some of the biochemical changes are reversible after the blood is transfused, the biomechanical changes are less so, and rejuvenation products are not yet able to adequately reverse this phenomenon.


title: Blood bank

text: Current regulatory measures are in place to minimize RBC storage lesion—including a maximum shelf life (currently 42 days), a maximum auto-hemolysis threshold (currently 1% in the US), and a minimum level of post-transfusion RBC survival "in vivo" (currently 75% after 24 hours). However, all of these criteria are applied in a universal manner that does not account for differences among units of product; for example, testing for the post-transfusion RBC survival "in vivo" is done on a sample of healthy volunteers, and then compliance is presumed for all RBC units based on universal (GMP) processing standards. RBC survival does not guarantee efficacy, but it is a necessary prerequisite for cell function, and hence serves as a regulatory proxy. Opinions vary as to the best way to determine transfusion efficacy in a patient "in vivo". In general, there are not yet any "in vitro" tests to assess quality deterioration or preservation for specific units of RBC blood product prior to their transfusion, though there is exploration of potentially relevant tests based on RBC membrane properties such as erythrocyte deformability and erythrocyte fragility (mechanical).


title: Blood bank

text: Many physicians have adopted a so-called "restrictive protocol"—whereby transfusion is held to a minimum—due in part to the noted uncertainties surrounding storage lesion, in addition to the very high direct and indirect costs of transfusions, along with the increasing view that many transfusions are inappropriate or use too many RBC units.


title: Blood bank

text: Platelet storage lesion is a very different phenomenon from RBC storage lesion, due largely to the different functions of the products and purposes of the respective transfusions, along with different processing issues and inventory management considerations.


title: Blood bank

text: Although as noted the primary inventory-management approach is first in, first out (FIFO) to minimize product expiration, there are some deviations from this policy—both in current practice as well as under research. For example, exchange transfusion of RBC in neonates calls for use of blood product that is five days old or less, to "ensure" optimal cell function. Also, some hospital blood banks will attempt to accommodate physicians' requests to provide low-aged RBC product for certain kinds of patients (e.g. cardiac surgery).


title: Blood bank

text: More recently, novel approaches are being explored to complement or replace FIFO. One is to balance the desire to reduce average product age (at transfusion) with the need to maintain sufficient availability of non-outdated product, leading to a strategic blend of FIFO with last in, first out (LIFO).


title: Blood bank

text: "Long-term" storage for all blood products is relatively uncommon, compared to routine/short-term storage. Cryopreservation of red blood cells is done to store rare units for up to ten years. The cells are incubated in a glycerol solution which acts as a cryoprotectant ("antifreeze") within the cells. The units are then placed in special sterile containers in a freezer at very low temperatures. The exact temperature depends on the glycerol concentration.


title: Member states of the Arab League

text: The Arab League has 22 member states. It was founded in Cairo in March 1945 with six members: the Kingdom of Egypt, Kingdom of Iraq, Lebanon, Saudi Arabia, Syrian Republic, and Transjordan (Jordan from 1949). North Yemen (later becoming Yemen) joined on 5 May 1945. Membership increased during the second half of the 20th century. Seven countries have observer status. The headquarters are located in Cairo, Egypt.


title: Member states of the Arab League

text: Seven countries are observer states—a status that entitles them to express their opinion and give advice but denies them voting rights. These are Eritrea, where Arabic is one of the official languages, as well as Brazil and Venezuela, which have large and influential Arab communities. India is another observer to the Arab League, with a sizable number of people claiming Arab descent. Armenia was granted observer status in 2004. Chad was granted observer status in 2005.


title: Member states of the Arab League

text: Only one country where Arabic is an official language remains outside of the League: Chad. In Malta, Eritrea and South Sudan, although Arabic is not an official language, a dialect of the language is spoken by portions of the populations in these countries. Additionally, there are two other Arabic-speaking states with limited recognition – Sahrawi Arab Democratic Republic and Somaliland – but their disputed status, being claimed by League members Morocco and Somalia respectively, makes their membership unlikely for the foreseeable future.


title: Member states of the Arab League

text: Chad's membership was endorsed by the Egyptian government under Hosni Mubarak in 2010. Chad applied for membership on 25 March 2014. Arabic is one of its two official languages, some 12% of Chadians identifying as Arab and around 900,000 are Arabic-speaking. Chad has had observer status since 2005.


title: Member states of the Arab League

text: Eritrea applied for membership on 25 March 2014. To be considered for membership, Eritrea needs to improve its relations with other neighboring League members, including Djibouti, Sudan and Somalia. Eritrea has had observer status since 2003.


title: Member states of the Arab League

text: South Sudan declared its independence from League member state Sudan in July 2011. A clause in the Charter of the Arab League accords the right of territories that have seceded from an Arab League member state to join the organization. South Sudan has been assured full membership in the Arab League should its government choose to seek it. Alternatively, the nation could opt for observer status. It has indicated that it would not be joining the League since the government believes it does not meet the pre-conditions for membership; specifically, that "the League requires that the countries must be Arabic speaking countries that consider Arabic language the main language of the nation; on top of that, the league also requires that the people of that particular country must believe that they are actually Arabs. The people of Southern Sudan are not of Arabic origin, so I don't think there will be anybody in Southern Sudan who will consider joining the Arab League". In an interview with "Asharq Al-Awsat", the Foreign Minister of South Sudan Deng Alor Kuol said: South Sudan is the closest African country to the Arab world, and we speak a special kind of Arabic known as Juba Arabic. Sudan supports South Sudan’s request to join the Arab League. South Sudan applied for observer status in March 2018.


title: Member states of the Arab League

text: The Sahrawi Arab Democratic Republic is not a member though it is recognized by some Arab League states. Its status is disputed, its territory being claimed by League member Morocco, which makes its membership unlikely for the foreseeable future.


title: Member states of the Arab League

text: Latin America and the Caribbean is the home of a large, influential Arab population, mostly reside in Mexico, Honduras, Argentina, Venezuela, Brazil, Colombia, Uruguay, Chile, Panama, Ecuador, Jamaica, Haiti and Guatemala. However, these countries use Spanish, Portuguese, English and French as official languages, and have demonstrated little interests on joining the Arab League. Brazil and Venezuela are the only two observers in the League.


title: Member states of the Arab League

text: Egypt - Egypt's membership was suspended in March 1979 after it signed the Egypt–Israel peace treaty and the League's headquarters were moved from Cairo to Tunis. In 1987, Arab League states restored diplomatic relations with Egypt, the country was readmitted to the League in May 1989 and the League's headquarters were moved back to Cairo in September 1990.


title: Member states of the Arab League

text: Libya - Libya was suspended from the Arab League on 22 February 2011. On 27 August 2011, the Arab League voted to restore Libya's membership by accrediting a representative of the National Transitional Council, which was partially recognised as the interim government of the country in the wake of Gaddafi's ouster from the capital of Tripoli.


title: Member states of the Arab League

text: Libya's membership was suspended on 22 February 2011, following the start of the Libyan Civil War and the use of military force against civilians. That makes Libya the second country in the League's history to have a frozen membership. Libyan leader Muammar Gaddafi declared that the League was illegitimate, saying: "The Arab League is finished. There is no such thing as the Arab League". On 25 August 2011, Secretary-General Nabil Elaraby announced it was "about time" Libya's full member status was restored. The National Transitional Council, the partially recognised interim government of Libya, sent a representative to be seated at the Arab League meeting on 17 August to participate in a discussion as to whether to readmit Libya to the organisation.


title: Member states of the Arab League

text: Syria - On 20 September 2011, the Arab Parliament recommended suspension of Syria and Yemen over persistent reports of disproportionate violence against regime opponents and activists during the Arab Spring. On 12 November 2011, the League passed a decree that would suspend Ba'athist Syrian Arab Republic's membership if the government failed to stop violence against civilian protesters by 16 November 2011 amidst the uprising. Syria, Lebanon and Yemen voted against the motion, and Iraq abstained. Despite the opportunity, the Syrian government did not yield to the League's demands, resulting in its indefinite suspension. There was criticism after the Arab League sent in December 2011 a commission "monitoring" violence on people protesting against the regime. The commission was headed by Mohammad Ahmed Mustafa al-Dabi, who served as head of Omar al-Bashir's military intelligence, while war crimes, including genocide, were allegedly committed on his watch. On 6 March 2013, the Arab League granted to the Syrian National Coalition Syria's seat in the Arab League. On 9 March 2014, the League's secretary general Nabil al-Arabi said that Syria's seat at the Arab League would remain vacant until the opposition completes the formation of its institutions.


title: Michael Madhusudan Dutt

text: Michael Madhusudan Dutt ((Bengali: মাইকেল মধুসূদন দত্ত); (25 January 1824 – 29 June 1873) was a Bengali poet and playwright. He is considered one of the pioneers of Bengali literature.


title: Michael Madhusudan Dutt

text: Dutt was born in Sagardari, a village in Keshabpur Upazila, Jessore District of Bengal, to a Hindu family. His family being reasonably well-off, Dutt received an education in the English language and additional tutorship in English at home. Rajnarayan had intended for this Western education to open the doors for a government position for his son.


title: Michael Madhusudan Dutt

text: After he finished his education in Sagordari at roughly the age of fifteen, Rajnarayan sent Madhusudhan to Calcutta to attend Hindu College with the eventual aim of becoming a barrister. At Hindu College, Michael studied under a westernized curriculum in a university which had been expressly founded for the "uplift of the natives". The university stipulated that all students had to dress in Western clothing, eat European cuisine using cutlery, learn British songs and speak only English with the aim of creating an anglicized middle class of Indians which would serve as officials in the colonial administration. During his time at Hindu College, Madhusudhan developed an aversion to Indian culture and a deep yearning to become accepted into European culture. He expressed these sentiments in one of his poems:


title: Michael Madhusudan Dutt

text: An early and formative influence on Dutta was his teacher at Hindu College, David Lester Richardson. Richardson was a poet and inspired in Dutta a love of English poetry, particularly Byron. Dutta began writing English poetry aged around 17 years, sending his works to publications in England, including "Blackwood's Magazine" and "Bentley's Miscellany". They were, however, never accepted for publication. This was also the time when he began a correspondence with his friend, Gour Das Bysack, which today forms the bulk of sources on his life.


title: Michael Madhusudan Dutt

text: Madhusudan embraced Christianity at the Old Mission Church, in spite of the objections of his parents and relatives, on 9 February 1843. He did not take the name Michael until his marriage in 1848.


title: Michael Madhusudan Dutt

text: He had to leave Hindu College on account of being a convert. In 1844, he resumed his education at Bishop's College, where he stayed for three years.


title: Michael Madhusudan Dutt

text: In 1847, he moved to Madras (Chennai) due to family tensions and economic hardship, having been disinherited by his father. While in Madras, he stayed in the Black Town neighbourhood, and began working as an "usher" at the Madras Male Orphan Asylum. Four years later, in 1851, he became a Second Tutor in the Madras University High School. He edited and assisted in editing the periodicals "Madras Circulator and General Chronicle, Athenaeum, Spectator" and "Hindoo Chronicle."


title: Michael Madhusudan Dutt

text: Dutta wrote exclusively in English in his early writing years. The Captive Ladie was published in 1849 and, like Derozio's The Fakeer of Jungheera, takes on the form of a long narrative poem. In "The Anglo-Saxon and the Hindu" (1854), an essay in florid, even purple, prose, are references to and quotations from almost the whole of Macaulay's shelf of European books. He was greatly influenced by the works of William Wordsworth and John Milton. Dutta was a spirited bohemian and Romantic.


title: Michael Madhusudan Dutt

text: The period during which he worked as a head clerk and later as the Chief Interpreter in the court marked his transition to writing in his native Bengali, following the advice of Bethune and Bysack. He wrote 5 plays: "Sermista" (1859)", Padmavati" (1859)", Ekei Ki Boley Sabyata" (1860), "Krishna Kumari" (1860) "and Buro Shaliker Ghare Ron" (1860). Then followed the narrative poems: "Tilottama Sambhava Kavya" (1861), "Meghnad Badh Kavya" (1861), "Brajagana Kavya" (1861) and "Veerangana Kavya" (1861). He also translated three plays from Bangla to English, including his own "Sermista".


title: Michael Madhusudan Dutt

text: A volume of his Bangla sonnets was published in 1866. His final play, "Maya Kannan", was written in 1872. "The Slaying of Hector", his prose version of the "Iliad" remains incomplete.


title: Michael Madhusudan Dutt

text: Madhusudan was a gifted linguist and polyglot. He studied English, Bengali, Hebrew, Latin, Greek, Tamil, Telugu, and Sanskrit.


title: Michael Madhusudan Dutt

text: Michael Madhusudan Dutt dedicated his first sonnet to his friend Rajnarayan Basu, which he accompanied with a letter: "What say you to this, my good friend? In my humble opinion, if cultivated by men of genius, our sonnet in time would rival the Italian." His most famous sonnet is "Kapatakkha River".


title: Michael Madhusudan Dutt

text: When Dutta later stayed in Versailles, the sixth centenary of the Italian poet Dante Alighieri was being celebrated all over Europe. He composed a poem in honour of the poet, translated it into French and Italian, and sent it to the king of Italy. Victor Emmanuel II, then monarch, liked the poem and wrote to Dutt, saying, "It will be a ring which will connect the Orient with the Occident."


title: Michael Madhusudan Dutt

text: "Sharmistha" (spelt as "Sermista" in English) was Dutt's first attempt at blank verse in Bengali literature. Kaliprasanna Singha organised a felicitation ceremony to Madhusudan to mark the introduction of blank verse in Bengali poetry. His famous epic, quoted as the only epic of Bengali-kind, Meghnadbad-Kabya is also totally written in blank verse.


title: Michael Madhusudan Dutt

text: Praising Dutt's blank verse, Sir Ashutosh Mukherjee, observed: "As long as the Bengali race and Bengali literature would exist, the sweet lyre of Madhusudan would never cease playing." He added: "Ordinarily, reading of poetry causes a soporific effect, but the intoxicating vigour of Madhusudan's poems makes even a sick man sit up on his bed."


title: Michael Madhusudan Dutt

text: In his "The Autobiography of an Unknown Indian", Nirad C. Chaudhuri has remarked that during his childhood days in Kishoreganj, a common standard for testing guests' erudition in the Bengali language during family gatherings was to require them to recite the poetry of Dutt, without an accent.


title: Michael Madhusudan Dutt

text: His family joined him in 1863, and thereafter they shifted to the much cheaper Versailles, due to the miserable state of their finances. Funds were not arriving from India according to his plans. He was only able to relocate to England in 1865 and study for the bar due to the munificent generosity of Ishwar Chandra Vidyasagar. For this, Dutta was to regard Vidyasagar as "Dayar Sagar" (meaning "the ocean of kindness") for as long as he lived. He was admitted to the High Court in Calcutta on his return in February 1867. His family followed him in 1869.


title: Michael Madhusudan Dutt

text: His stay in England had left him disillusioned with European culture. He wrote to his friend Bysack from France:


title: Michael Madhusudan Dutt

text: Dutta had refused to enter into an arranged marriage which his father had decided for him. He had no respect for that tradition and wanted to break free from the confines of caste-based endogamous marriage. His knowledge of the European tradition convinced him of his choice of marriages made by mutual consent (or love marriages).


title: Michael Madhusudan Dutt

text: He was the first Bengali to marry a European or Anglo-Indian woman. While in Madras he married Indo-Scottish-Britton, Rebecca Thompson McTavish, a 17-year-old resident of the Madras Female Orphan Asylum, on 31 July 1848. Dutta assumed the name Michael when the marriage was registered in the baptismal register. They had four children together. He wrote to Bysack in December 1855:


title: Michael Madhusudan Dutt

text: Dutta returned from Madras to Calcutta in February 1856, after his father's death (in 1855), abandoning his wife and four children in Madras. No records of his divorce from Rebecca or remarriage have been found. In 1858, he was joined there by a 22-year old of French extraction, Emelia Henrietta Sophie White, the daughter of his colleague at the Madras Male Orphan Asylum. They had two sons, Frederick Michael Milton (23 July 1861 – 11 June 1875) and Albert Napoleon (1869 – 22 August 1909), and a daughter, Henrietta Elizabeth Sermista (1859 – 15 February 1879). A fourth child was stillborn. Their relationship lasted until the end of his life, Henrietta pre-deceasing him by three days, on 26 June 1873.


title: Michael Madhusudan Dutt

text: Rebecca died in Madras in July 1892. Only a daughter and a son survived her. The son, McTavish-Dutt, practised as a pleader in the Court of Small Causes in Madras.


title: Michael Madhusudan Dutt

text: The tennis player Leander Paes is a direct descendant of Dutt, who is his great-great-grandfather on his mother's side.


title: Michael Madhusudan Dutt

text: Dutta died in Calcutta General Hospital on 29 June 1873. Three days prior to his death, he recited a passage from Shakespeare's Macbeth to his dear friend Bysack, to express his deepest conviction of life:


title: Michael Madhusudan Dutt

text: Dutta was largely ignored for 15 years after his death. The belated tribute was a tomb erected at his gravesite.


title: Michael Madhusudan Dutt

text: "Michael Madhusudhan" is a 1950 Indian Bengali-language drama film by Modhu Bose which starred Utpal Dutt in the titular role.


title: Michael Madhusudan Dutt

text: Author Namita Gokhale published a play about Madhusudhan in 2021, based largely on letters written by him to friends and other authors, called "Betrayed by Hope".


title: Michael Madhusudan Dutt

text: In honour of Dutt, every year on his birthday a fair is held in his home at Sagardari. Which is organized by District Council of Jessore . Every year various MP and Minister of national parliament of Bangladesh attend this fair.


title: Michael Madhusudan Dutt

text: In honour of Dutt a school and a college are named after him in Jessore District. And a university was proposed to be set up in this birth place . They are ;


title: Spotted eagle ray

text: The spotted eagle ray ("Aetobatus narinari") is a cartilaginous fish of the eagle ray family, Myliobatidae. As traditionally recognized, it is found globally in tropical regions, including the Atlantic, Pacific and Indian Oceans. Recent authorities have restricted it to the Atlantic (including the Caribbean and Gulf of Mexico) with other populations recognized as the ocellated eagle ray ("A. ocellatus") and Pacific white-spotted eagle ray ("A. laticeps"). Spotted eagle rays are most commonly seen alone, but occasionally swim in groups. They are ovoviviparous, the female retaining the eggs then releasing the young as miniature versions of the parent.


title: Spotted eagle ray

text: This ray can be identified by its dark dorsal surface covered in white spots or rings. Near the base of the ray's relatively long tail, just behind the pelvic fins, are several venomous, barbed stingers. Spotted eagle rays commonly feed on small fish and crustaceans, and will sometimes dig with their snouts to look for food buried in the sand of the sea bed. These rays are commonly observed leaping out of the water, and on at least two occasions have been reported as having jumped into boats, in one incident resulting in the death of a woman in the Florida Keys. The spotted eagle ray is hunted by a wide variety of sharks. The rays are considered near threatened on the IUCN Red List. They are fished mainly in Southeast Asia and Africa, the most common market being in commercial trade and aquariums. They are protected in the Great Barrier Reef.


title: Spotted eagle ray

text: The spotted eagle ray was first described by Swedish botanist Bengt Anders Euphrasén as "Raja narinari" in 1790 from a specimen collected at an unknown location (possibly the coast of Brazil) during a trip he made to the Antilles, and was later classified as "Stoasodon narinari". Its current genus name is "Aetobatus", derived from the Greek words "aetos" (eagle) and "batis" (ray). The spotted eagle ray belongs to the Myliobatidae, which includes the well known manta ray. Most rays in the family Myliobatidae swim in the open ocean rather than close to the sea floor.


title: Spotted eagle ray

text: Although traditionally considered to have a circumglobal distribution in tropical oceans throughout the world, recent authorities have restricted the true "Aetobatus narinari" to the Atlantic Ocean based on genetic and morphologic evidence. The Indo-Pacific population is "Aetobatus ocellatus" and the East Pacific is "Aetobatus laticeps".


title: Spotted eagle ray

text: The spotted eagle ray has many different common names, including white-spotted eagle ray, bonnet skate, bonnet ray, duckbill ray and spotted duck-billed ray.


title: Spotted eagle ray

text: Spotted eagle rays have flat disk-shaped bodies, deep blue or black with white spots on top with a white underbelly, and distinctive flat snouts similar to a duck's bill. Their tails are longer than those of other rays and may have 2–6 venomous spines, just behind the pelvic fins. The front half of the long and wing-like pectoral disk has five small gills in its underside.


title: Spotted eagle ray

text: Mature spotted eagle rays can be up to in length; the largest have a wingspan of up to and a mass of .


title: Spotted eagle ray

text: One male, or sometimes several, will pursue a female. When one of the males approaches the female, he uses his upper jaw to grab her dorsum. The male will then roll the female over by grabbing one of her pectoral fins, which are located on either side of her body. Once he is on her ventral side, the male puts a clasper into the female, connecting them venter to venter, with both undersides together. The mating process lasts for 30–90 seconds.


title: Spotted eagle ray

text: The spotted eagle ray develops ovoviviparously; the eggs are retained in the female and hatch internally, feeding off a yolk sac until live birth. After a gestation period of one year the mother ray will give birth to a maximum of four pups. When the pups are first born, their discs measure from across. The rays mature in 4 to 6 years.


title: Spotted eagle ray

text: Spotted eagle ray preys mainly upon bivalves, crabs, whelks and other benthic infauna. They also feed on mollusks (such as the queen conch) and crustaceans, particularly malacostracans, as well as echinoderms, polychaete worms, hermit crabs, shrimp, octopuses, and some small fish.


title: Spotted eagle ray

text: The spotted eagle ray's specialized chevron-shaped tooth structure helps it to crush the mollusks' hard shells. The jaws of these rays have developed calcified struts to help them break through the shells of mollusks, by supporting the jaws and preventing dents from hard prey. These rays have the unique behavior of digging with their snouts in the sand of the ocean. While doing this, a cloud of sand surrounds the ray and sand spews from its gills. One study has shown that there are no differences in the feeding habits of males and females or in rays from different regions of Australia and Taiwan.


title: Spotted eagle ray

text: Spotted eagle rays prefer to swim in waters of . Their daily movement is influenced by the tides; one tracking study showed that they are more active during high tides. Uniquely among rays they dig with their snouts in the sand, surrounding themselves in a cloud of sand that spews from their gills. They also exhibit two motions in which the abdomen and the pectoral fins are moved rapidly up and down: the pelvic thrust and the extreme pelvic thrust. The pelvic thrust is usually performed by a solitary ray, and repeated four to five times rapidly. The extreme pelvic thrust is most commonly observed when the ray is swimming in a group, from which it will separate itself before vigorously thrusting with its pectoral fins. The rays also performs dips and jumps; in a dip the ray will dive and then come back up rapidly, perhaps as many as five times consecutively. There are two main types of jump: in one, the ray propels itself vertically out of the water, to which it returns along the same line; the other is when the ray leaps at a 45 degree angle, often repeated multiple times at high speeds. When in shallow waters or outside their normal swimming areas the rays are most commonly seen alone, but they do also congregate in schools. One form of travelling is called loose aggregation, which is when three to sixteen rays are swimming in a loose group, with occasional interactions between them. A school commonly consists of six or more rays swimming in the same direction at exactly the same speed.


title: Spotted eagle ray

text: The dorsal spots make the spotted eagle ray an aquarium attraction, although because of its large size it is likely kept only at public aquariums. There are no target fisheries for the spotted eagle ray, but it is often eaten after being caught unintentionally as bycatch. There have been several reported incidents of spotted eagle rays leaping out of the water onto boats and landing on people. Nevertheless, spotted eagle rays do not pose a significant threat to humans, as they are shy and generally avoid human contact. Interactions with an individual snorkeler in the Caribbean has been reported especially in Jamaica involving one, two and even three spotted eagle rays. The rays may exhibit a behavior similar to human curiosity which allows the snorkeler to observe the eagle ray who may slow down so as to share more time with the much slower human observer if the human observer appears to be unthreatening or interesting to the spotted eagle ray.


title: Spotted eagle ray

text: Spotted eagle rays, in common with many other rays, often fall victim to sharks such as the tiger shark, the lemon shark, the bull shark, the silver tip shark, and the great hammerhead shark. A great hammerhead shark has been observed attacking a spotted eagle ray in open water by taking a large bite out of one of its pectoral fins, thus incapacitating the ray. The shark then used its head to pin the ray to the bottom and pivoted to take the ray in its jaws, head first. Sharks have also been observed to follow female rays during the birthing season, and feed on the newborn pups.


title: Spotted eagle ray

text: As other rays, spotted eagle rays are host to a variety of parasites. Internal parasites include the gnathostomatid nematode "Echinocephalus sinensis" in the spiral intestine. External parasites include the monocotylid monogeneans "Decacotyle octona", "Decacotyle elpora" and "Thaumatocotyle pseudodasybatis" on the gills.


title: Spotted eagle ray

text: As traditionally defined, spotted eagle rays are found globally in tropical regions from the Indo-Pacific region from the western Pacific Ocean, the Indian Ocean, and the western Atlantic Ocean.


title: Spotted eagle ray

text: Spotted eagle rays are found in warm and temperate waters worldwide. In the western Atlantic Ocean it is found off the eastern coast of United States of America, the Gulf Stream, the Caribbean, and down past the southern part of Brazil. In the Indian Ocean, it is found from the Red Sea down to South Africa and eastward to the Andaman Sea. In the Western Pacific Ocean it can be found near Japan and north of Australia. In the Central Pacific Ocean, it can be found throughout the Hawaiian Islands. In the Eastern-Pacific Ocean, it is found in the Gulf of California down through Puerto Pizarro, an area that includes the Galapagos Islands. Spotted eagle rays are most commonly seen in bays and reefs. They spend much of their time swimming freely in open waters, generally in schools close to the surface, and can travel long distances in a day.


title: Spotted eagle ray

text: Within these regions, there are significant variations in genetics and morphology. As a consequence, recent authorities have split it into three: This restricts the true spotted eagle ray ("A. narinari") to the Atlantic, while the Indo-Pacific population is the ocellated eagle ray ("A. ocellatus") and the East Pacific is the Pacific white-spotted eagle ray ("A. laticeps").


title: Spotted eagle ray

text: The spotted eagle ray is included in the IUCN's Red List as "near threatened". The rays are caught mainly in Southeast Asia and Africa. They are also common in commercial marine life trade and are displayed in aquariums. Among the many efforts to help protect this species, South Africa's decision to deploy fewer protective shark nets has reduced the number of deaths caused by entanglement. South Africa has also placed restrictions on the number of rays that can be bought per person per day. In the U.S. state of Florida, the fishing, landing, purchasing and trading of spotted eagle ray are outlawed. This ray is also protected in the Great Barrier Reef on the eastern coast of Australia.


title: Spotted eagle ray

text: In Europe there is a breeding program managed by the EAZA for spotted eagle rays to reduce the amount of wild caught individuals needed by public aquaria. From the start until 2018 Burgers' Zoo in the Netherlands kept the studbook. Since 2018, Wroclaw Zoo in Poland is the new studbook keeper. Burgers' Zoo was also the first place in Europe to breed with the species and in 2018 was the most successful breeder worldwide with over 55 births.


title: The Big Heat

text: The Big Heat is a 1953 American film noir crime film directed by Fritz Lang starring Glenn Ford, Gloria Grahame, and Jocelyn Brando about a cop who takes on the crime syndicate that controls his city. William P. McGivern's serial in "The Saturday Evening Post", published as a novel in 1953, was the basis for the screenplay, written by former crime reporter Sydney Boehm. The film was selected for inclusion in the National Film Registry of the Library of Congress in 2011.


title: The Big Heat

text: Homicide detective Sergeant Dave Bannion, of the Kenport Police Department, is called to investigate the suicide of a rogue fellow officer, Tom Duncan. His wife, Bertha Duncan, says her husband had recently been in ill health. He left behind an envelope addressed to the district attorney, which she keeps under wraps and locks away in her safe-deposit box at the bank.


title: The Big Heat

text: The mistress of the late cop, Lucy Chapman, contradicts Mrs. Duncan, telling Sgt. Bannion that Tom Duncan had not been in ill health, and had no reason to kill himself, but had recently agreed to a divorce with his wife. Meanwhile Duncan's widow refuses to explain the couple's luxurious home. The next day, Lieutenant Ted Wilks is under pressure from "upstairs" to close the case, and rebuffs Bannion. Lucy Chapman is found strangled to death, her body covered with cigarette burns. Although the Chapman case is in the sheriff's jurisdiction, Bannion investigates and receives threatening calls at his home. He confronts Mike Lagana, a mob boss that runs the city, and discovers that people are too scared to stand up to the crime syndicate. When Bannion ignores warnings to desist, his car is planted with explosives. The car bomb kills his wife, Katie. Accusing his superiors of corruption, Bannion chides corrupt Police Commissioner Higgins, accusing him of obeying the orders of Lagana. Higgins puts Bannion on immediate suspension and orders him to turn in his badge. Determined to find those responsible for his wife's murder, Bannion continues to investigate.


title: The Big Heat

text: He hopes to discover a lead at a nightclub called "The Retreat". When Lagana's second-in-command, Vince Stone, punishes a woman there, burning her with a cigar butt, Bannion stands up to him and his thugs. This impresses Stone's girlfriend, Debby Marsh. The two hit it off and take a cab to the hotel where he is now living. When Debby accidentally reminds Bannion about his late wife, he tells her to leave. Debby reluctantly returns to Stone's penthouse. He accuses her of talking to Bannion about his activities and throws a pot of boiling coffee in her face. Higgins, who had been playing poker with Stone and his group there, takes her to a hospital.


title: The Big Heat

text: Debby returns to Bannion at his hotel; the left side of her face badly burned and half-covered in bandages. For protection, he puts her in a hotel room close to his. Debby identifies the man who had arranged the planting of the car bomb as Larry Gordon, one of Stone's associates. She also tells him where Gordon is staying at. Bannion forces Gordon to admit to the car-bombing, and to reveal that Duncan's widow is blackmailing Stone and Lagana with incriminating documents. Bannion does not kill Gordon, but promises to spread the word that he talked. Afterward, Gordon is killed by Stone's men. Bannion then confronts Mrs. Duncan, accusing her of betraying Lucy Chapman and protecting Lagana and Stone. With his hands at her throat, Bannion tells Mrs. Duncan that if she is killed, the evidence she has against Lagana will be revealed. Before Bannion can follow through on his threats, cops sent by Lagana arrive, and he is forced to leave.


title: The Big Heat

text: Bannion goes to deal with Stone when Wilks arrives, now prepared to take a stand against the mob and his corrupt boss. Debby goes to Mrs. Duncan and starts talking about their respective associations with gangsters. When Mrs. Duncan attempts to phone Stone for help, Debby shoots her dead.


title: The Big Heat

text: Bannion tails Stone, who returns to his penthouse, where Debby has been waiting for him. She throws boiling coffee in his face in an act of revenge. In retaliation, Stone shoots her. After a short gun battle, Bannion captures Stone. As Debby dies on the floor, she confesses to shooting Mrs. Duncan. Stone is arrested for murder and officer Duncan's damning evidence in the note he left behind for the D.A. is made public. Lagana and Higgins are indicted, and Bannion is reinstated to his job as a homicide detective.


title: The Big Heat

text: The film was based on a fictional serial by William P. McGivern, which appeared in the "Saturday Evening Post" from December 1952 and was published as a novel in 1953. Initially, McGivern's novel was to be produced by Jerry Wald, who wanted either Paul Muni, George Raft or Edward G. Robinson (who worked with director Fritz Lang in "Woman in the Window" and "Scarlet Street") for the role of Dave Bannion. Columbia Pictures paid $40,000 for McGivern's novel. Lang directed the film while Sydney Boehm wrote it.


title: The Big Heat

text: Boehm changed many details in the novel. Commissioner Higgins is not in the novel and Lieutenant Wilks is the corrupt policeman. An honest policeman called Cranston, who was in the novel, was omitted from the film.


title: The Big Heat

text: In the novel, it is not known until the end that the widow of the policeman who had killed himself (named Deery in the book, Duncan in the film) was blackmailing Lagana. Debby shoots her and then mortally wounds herself. After Stone is cornered by Bannion, he is killed by another policeman. Instead of taking place in Philadelphia, the film takes place in the fictional city of Kenport.


title: The Big Heat

text: Columbia wanted Marilyn Monroe to play the part of Debby Marsh but did not want to pay the fee 20th Century Fox demanded for the loan of their star, so Gloria Grahame was cast instead.


title: The Big Heat

text: Rex Reason was slated to play either Tierney or Detective Burke, but his agent wanted a larger part. In the end, Reason was not cast and Peter Whitney and Robert Burton got the roles of Tierney and Burke respectively.


title: The Big Heat

text: In the scene at the bar where Stone and Bannion first meet, the house band is performing "Put the Blame on Mame," a song also heard in the 1946 noir classic "Gilda", also starring Ford, and also produced by Columbia.


title: The Big Heat

text: "The New York Times" and "Variety" both gave "The Big Heat" very positive reviews at the time. Bosley Crowther of the "Times" described Glenn Ford "as its taut, relentless star" and praised Lang for bringing "forth a hot one with a sting." "Variety" characterized Lang's direction as "tense" and "forceful." Critic Roger Ebert subsequently praised the film's supporting actors and added the film to his personal canon of "Great Movies".


title: The Big Heat

text: Writer David M. Meyer states that the film never overcomes the basic repulsiveness of its hero, but notes that some parts of the film, though violent, are better than the film as a whole: "Best known is Gloria Grahame's disfigurement at the hands of psycho-thug Lee Marvin, who flings hot coffee into her face."


title: The Big Heat

text: According to film critic Grant Tracey, the film turns the role of the "femme fatale" on its head: "Whereas many noirs contain the tradition of the femme-fatale, the deadly spiderwoman who destroys her man and his family and career, "The Big Heat" inverts this narrative paradigm, making Ford [Det. Bannion] the indirect agent of fatal destruction. All four women he meets—from clip joint singer, Lucy Chapman, to gun moll Debby—are destroyed."


title: The Big Heat

text: In December 2011, "The Big Heat" was selected for inclusion in the Library of Congress' National Film Registry. Proclaiming it "one of the great post-war noir films", the Registry stated that "The Big Heat" "manages to be both stylized and brutally realistic, a signature of its director Fritz Lang."


title: Penang Island

text: Penang Island (; ; ) is part of the state of Penang, on the west coast of Peninsular Malaysia. It was named Prince of Wales Island when it was occupied by the British East India Company on 12 August 1786, in honour of the birthday of the Prince of Wales, later King George IV. The capital, George Town, was named after the reigning King George III.


title: Penang Island

text: Malaysia has another island called "Pulau Pinang", which is a diving site located in South China Sea and part of the Johor Marine Park, which consists of a group of islands: Pulau Aur, Pulau Dayang, Pulau Lang, and Pulau Pinang itself.


title: Penang Island

text: Penang was originally part of the Malay Sultanate of Kedah. On 11 August 1786, Captain Francis Light of the British East India Company landed in Penang and renamed it Prince of Wales Island in honour of heir to the British throne. Light then received it as a portion on his purported marriage to the daughter of the Sultan of Kedah, although there is no evidence supporting this, as Light was married to Martina Rozells, a Eurasian he met in Phuket. Light ceded Penang to the Government of India and promised the Sultan military protection from Siamese and Burmese armies who were threatening Kedah. Light is now credited as the founder of Penang.


title: Penang Island

text: Unbeknownst to the Sultan, Light had acted without the approval of the East India Company when he promised military protection. When the Company failed to aid Kedah when Siam attacked it, the Sultan tried to retake the island in 1790. The attempt was unsuccessful, and the Sultan was forced to cede the island to the company for an honorarium of 6,000 Spanish dollars per annum. This was later increased to 10,000 dollars, with Province Wellesley on the mainland of the Malay Peninsula being added to Penang in 1800. An annual honorarium of 10,000 ringgit continues to this day be paid by the Malaysian Federal Government to the state of Kedah.


title: Penang Island

text: In 1826, Penang, along with Malacca and Singapore, became part of the Straits Settlements under the British administration in India, moving to direct British colonial rule in 1867. In 1946 it became part of the Malayan Union, before becoming in 1948 a state of the Federation of Malaya, which gained independence in 1957 and became Malaysia in 1963. The island was a free port until 1969.


title: Penang Island

text: With an area of , Penang Island is the fourth-largest island wholly in Malaysia, after Banggi Island, Bruit Island and Langkawi Island. It is also the most populated island in the country with an estimated population of 678,000. The island is connected with the mainland by two Penang Bridges. The 1st bridge begins at Gelugor on the island and ends in Perai on the mainland while the 2nd bridge is located to its south. The mainland portion of the Penang state is known as Seberang Perai (Province Wellesley), and together with Penang Island and other smaller islands, form the state of Penang.


title: Penang Island

text: Penang Island is under the state of Penang, which is one of the four states in Malaysia without a Sultan and the head of the state is the Yang di-Pertua Negeri (English: State Ruler), which is appointed by the Yang di-Pertuan Agong of Malaysia.


title: Penang Island

text: The island forms the local government area of the Penang Island City Council and is divided into two administrative districts—South West Penang Island and North East Penang Island.


title: Penang Island

text: Other than a state ruler, Penang's executive members are led by a chief minister. The current chief minister of Penang is Chow Kon Yeow, and the post has been continuously held by a non-Malay ethnic Chinese since independence, reflecting the state's ethnic majority.


title: Penang Island

text: The local council on the island is the Penang Island City Council (Majlis Bandaraya Pulau Pinang). Local councillors have been appointed by the state government since local elections were abolished in Malaysia in the 1960s. The city council is made up of a mayor, a municipal secretary and 24 councillors. The mayor is appointed by the State Government for two-year term of office while the councillors are appointed for one-year term of office. Penang Island is divided into 2 administrative districts.


title: Penang Island

text: The eastern portion of the island facing the mainland is highly urbanised and built-up with either industrial, commercial or residential areas. The western portion is generally more rugged/hilly and less developed than the rest of the island.


title: Mastery learning

text: Mastery learning (or, as it was initially called, "learning for mastery"; also known as "mastery-based learning") is an instructional strategy and educational philosophy, first formally proposed by Benjamin Bloom in 1968. Mastery learning maintains that students must achieve a level of mastery (e.g., 90% on a knowledge test) in prerequisite knowledge before moving forward to learn subsequent information. If a student does not achieve mastery on the test, they are given additional support in learning and reviewing the information and then tested again. This cycle continues until the learner accomplishes mastery, and they may then move on to the next stage.


title: Mastery learning

text: Mastery learning methods suggest that the focus of instruction should be the time required for different students to learn the same material and achieve the same level of mastery. This is very much in contrast with classic models of teaching that focus more on differences in students' ability and where all students are given approximately the same amount of time to learn and the same set of instructions.


title: Mastery learning

text: In mastery learning, there is a shift in responsibilities, so that the students' failure is considered to be more due to the instruction and not necessarily their lack of ability. This also means teachers' attention to individual students is emphasised as opposed to assessing group performance. Therefore, in a mastery learning environment, the challenge becomes providing enough time and employing instructional strategies so that all students can achieve the same level of learning.


title: Mastery learning

text: Since its conception, mastery learning has empirically been demonstrated to be effective in improving education outcomes in a variety of settings. Its effectiveness is influenced by the subject being taught, whether testing is designed locally or nationally, course pace and the amount of feedback provided to students.


title: Mastery learning

text: Mastery learning is a set of group-based, individualized, teaching and learning strategies based on the premise that students will achieve a high level of understanding in a given domain if they are given enough time.


title: Mastery learning

text: The motivation for mastery learning comes from trying to reduce achievement gaps for students in average school classrooms. During the 1960s John B. Carroll and Benjamin S. Bloom pointed out that, if students are normally distributed with respect to aptitude for a subject and if they are provided uniform instruction (in terms of quality and learning time), then achievement level at completion of the subject is also expected to be normally distributed. This can be illustrated as shown below:


title: Mastery learning

text: Mastery Learning approaches propose that, if each learner were to receive optimal quality of instruction and as much learning time as they require, then a majority of students could be expected to attain mastery. This situation would be represented as follows:


title: Mastery learning

text: In many situations educators preemptively use the normal curve for grading students. Bloom was critical of this usage, condemning it because it creates expectation by the teachers that some students will naturally be successful while others will not. Bloom defended that, if educators are effective, the distribution of achievement could and should be very different from the normal curve. Bloom proposed Mastery Learning as a way to address this. He believed that by using his approach, the majority of students (more than 90 percent) would achieve successful and rewarding learning. As an added advantage, Mastery Learning was also thought to create more positive interest and attitude towards the subject learned if compared with usual classroom methods.


title: Mastery learning

text: Individualized instruction has some elements in common with mastery learning, although it dispenses with group activities in favor of allowing more capable or more motivated students to progress ahead of others while maximizing teacher interaction with those students who need the most assistance.


title: Mastery learning

text: Bloom's 2 Sigma Problem is an educational phenomenon observed where the average student tutored one-to-one (using mastery learning techniques) performed two standard deviations better than students who learn via conventional instructional methods.


title: Mastery learning

text: Competency-based learning is a framework for the assessment of learning based on predetermined competencies. It draws inspiration from mastery learning.


title: Mastery learning

text: In the 1920s there were at least two attempts to produce mastery in students' learning: the Winnetka Plan, by Carleton Washburne and associates, and another approach by Henry C. Morrison, at the University of Chicago Laboratory School. Both these projects provided school situations where mastery of particular learning tasks - rather than time spent - was the central theme. While these ideas were popular for a while, they faded due primarily to the lack of technologies that could sustain a successful implementation.


title: Mastery learning

text: The idea of mastery learning resurfaced in the late 1950s and early 1960s as a corollary of programmed instruction, a technology invented by B.F. Skinner to improve teaching. Underlying programmed instruction was the idea that the learning of any behavior, no matter how complex, rested upon the learning of a sequence of less-complex component behaviors.


title: Mastery learning

text: Around that same time, John B. Carroll was working on his "Model of School Learning" - a conceptual paradigm which outlined the major factors influencing student success in school learning and indicating how these factors interacted. Carroll's model stemmed from his previous work with foreign language learning. He found that a student's aptitude for a language predicted not only the level to which they learned in a given time, but also the amount of time they required to learn to a given level. Carroll then suggests that aptitudes are actually a way to measure the amount of time required to learn a task up to a certain level (under ideal instructional conditions). As such, Carroll's model implies that, if each student is given the sufficient time they needed to learn to any particular level, then they would be expected to attain it.


title: Mastery learning

text: Later in the 1960s Benjamin Bloom and his graduate students were researching individual differences in school learning. They observed that teachers displayed very little variation in their instructional practices and yet, there was a lot of variation in student's achievements. Bloom used Carroll's conceptual model to create his own working model of Mastery Learning. Bloom realized that, if aptitudes were predictive of the rate at which a student can learn (and not necessarily the level to which), it should be possible to fix the degree of learning expected to some mastery level and then systematically manipulate the variables in Carroll's model such that all or almost all students attained that level.


title: Mastery learning

text: Also in the 1960s, Fred S. Keller was collaborating with colleagues developing his own instructional methods of Mastery Learning. Keller's strategies were based on the ideas of reinforcement as seen in operant conditioning theories. Keller formally introduced his teaching method, Personalized System of Instruction (PSI) - sometimes referred to as Keller Plan), in his 1967 paper, "Engineering personalized instruction in the classroom".


title: Mastery learning

text: From the late 1960s to the early 1980s, there was a surge of research on both Keller's and Bloom's instruction methods. Most of these studies showed that mastery learning has a positive effect on achievement, for all subjects and at all levels. Also, mastery learning brings positive affective outcomes for both students and teachers. These studies also showed that there are many variables that are either affected by mastery learning or that influence it somehow: student entry variables, curriculum, type of test, pacing, level of mastery, and time.


title: Mastery learning

text: Despite those mostly positive research results, interest in mastery learning strategies decreased throughout the 1980s, as reflected in publication activity in professional journals and presentations at conferences. Many explanations were put forward to justify this decline, like alleged recalcitrance of the educational establishment to change, or the ineffective implementations of mastery learning methods, or the extra time demanded in setting up and maintaining a mastery learning course or even concerns that behavioristic-based models for teaching would conflict with the generally humanistic-oriented teachers and the surrounding culture.


title: Mastery learning

text: Mastery learning strategies are best represented by Bloom's Learning For Mastery (LFM) and Keller's Personalized System of Instruction (PSI). Bloom's approach was focused in the schoolroom, whereas Keller developed his system for higher education. Both have been applied in many different contexts and have been found to be very powerful methods for increasing student performance in a wide range of activities. Despite sharing some commonalities in terms of goals, they are built on different psychological principles.


title: Mastery learning

text: Bloom, when first proposing his mastery learning strategy in 1968, was convinced that most students can attain a high level of learning capability if the following conditions are available:


title: Mastery learning

text: Aptitude, measured by standard aptitude tests, in this context is interpreted as "the amount of time required by the learner to attain mastery of a learning task".


title: Mastery learning

text: Several studies show that majority of students can achieve mastery in a learning task, but the time that they need to spend on is different.


title: Mastery learning

text: Bloom argues that there are 1 to 5 percent of students who have special talent for learning a subject (especially music and foreign languages) and there are also around five percent of students who have special disability for learning a subject. For other 90% of students, aptitude is merely an indicator of the rate of learning.


title: Mastery learning

text: Additionally, Bloom argues that aptitude for a learning task is not constant and can be changed by environmental conditions or learning experience at school or home.


title: Mastery learning

text: The quality of instruction is defined as the degree to which the presentation, explanation, and ordering of elements of the task to be learned approach the optimum for a given learner.


title: Mastery learning

text: Bloom insists that the quality of instruction has to be evaluated according to its effect on individual students rather than on random groups of students.


title: Mastery learning

text: Bloom shows that while in traditional classrooms, the relationship between students' aptitude test for mathematics and their final grade in algebra is very high, this relationship is almost zero for students who are receiving tutorial instruction in the home. He argues that a good tutor tries to find the quality of learning best fit to the given students, thus the majority of students would be able to master a subject if they have access to a good tutor.


title: Mastery learning

text: According to Bloom the ability to understand instruction is defined as the nature of the task that a learner is to learn and the procedure that the learner is to follow. Verbal ability and reading comprehension are two language abilities that are highly related to student achievements. Since the ability to understand instruction varies significantly among students, Bloom recommends that teachers modify their instruction, provide help, and teaching aids to fit the needs of different students. Some of the teaching aids that could be provided according to the ability of the learner are:


title: Mastery learning

text: Perseverance in this context is defined as the time the learner is willing to spend in learning. According to Bloom, a student who demonstrates a low level of perseverance in one learning task might have a very high level of perseverance in a different learning task. He suggests that students' perseverance be enhanced by increasing the frequency of reward and providing evidence of success in learning. He recommends that teachers use frequent feedback accompanied by specific help to improve the quality of instruction, thus reducing the perseverance required for learning.


title: Mastery learning

text: According to the International Study of Education in 12 countries, if the top 5% of students are omitted, the ratio of the time needed for slower and faster learners of a subject such as mathematics is 6 to 1 while there is zero or slightly negative relationship between the final grades and the amount of time spent on homework. Thus, the amount of time spent on homework is not a good indicator of mastery in a subject. Bloom postulates that the time required for a learner to achieve mastery in a specific subject is affected by various factors such as:


title: Mastery learning

text: LFM curricula generally consists of discrete topics which all students begin together. After beginning a unit, students will be given a meaningful and formative assessment so that the teacher can conclude whether or not an objective has been mastered. At this step, instruction goes in one of two directions. If a student has mastered an objective, he or she will begin on a path of enrichment activities that correspond to and build upon the original objective. Students who do not satisfactorily complete a topic are given additional instruction until they succeed. If a student does not demonstrate that he or she has mastered the objective, then a series of correctives will be employed. These correctives can include varying activities, individualized instruction, and additional time to complete assignments. These students will receive constructive feedback on their work and will be encouraged to revise and revisit their assignment until the objective is mastered.


title: Mastery learning

text: There are some preconditions for the process of mastery learning. First, the objectives and content of instruction have to be specified and clarified to both the students and the teacher. Another precondition is that the summative evaluation criteria should be developed and both the teacher and the learner should be clear about the achievement criteria. Bloom suggests that using absolute standards rather than competitive criteria, helps students to collaborate and facilitates mastery.


title: Mastery learning

text: The operating procedures are the methods used to provide detailed feedback and instructional help to facilitate the process of mastery in learning.


title: Mastery learning

text: Formative Evaluation in the context of mastery learning is a diagnostic progress tests to determine whether or not the student has mastered the subject unit. Each unit is usually a learning outcome that could be taught in a week or two of learning activity.


title: Mastery learning

text: The formative tests are administered at the learning units. Bloom insists that the diagnostic process has to be followed by a prescription and the result of formative assessment is better to express in not-grade format since the use of grades on repeated progress evaluations prepare students for accepting a level of learning less than mastery.


title: Mastery learning

text: The progress tests should be followed by detailed feedback and specific suggestions so that the students could work on their difficulties. Some of the alternative learning resources are:


title: Mastery learning

text: The cognitive outcomes of mastery learning are mainly related to increase in student excellence in a subject. According to one study, applying the strategies of mastery learning in a class resulted in the increase of students with the grade of A from 20 percent to 80 percent (about two standard deviation), and using the formative evaluation records as a base for quality control helped the teacher to improve the strategies and increase the percent of students with a grade of A to 90% in the following year.


title: Mastery learning

text: Affective outcomes of mastery are mainly related to the sense of self-efficacy and confidence in the learners. Bloom argues that when the society (through education system) recognizes a learner's mastery, profound changes happen in his or her view of self and the outer world. The learner would start believing that he or she is able to adequately cope with problems, would have higher motivation for learning the subject in a higher level of expertise, and would have a better mental state due to less feeling of frustration. Finally, it is argued that in a modern society that lifelong learning is a necessity, mastery learning can develop a lifelong interest and motivation in learning.


title: Mastery learning

text: Personalized System of Instruction, also known as the Keller Plan was developed in the mid 1960s by Fred Keller and colleagues. It was developed based on the idea of reinforcement in teaching processes.


title: Mastery learning

text: Keller gives the following description to a group of psychology students enrolled in his course developed using mastery learning theory: "This is a course through which you may move, from start to finish, at your own pace. You will not be held back by other students or forced to go ahead until you are ready. At best, you may meet all the course requirements in less than one semester; at worst, you may not complete the job within that time. How fast you go is up to you" (Keller, 1968, pg 80-81).


title: Mastery learning

text: In a mastery learning environment, the teacher directs a variety of group-based instructional techniques, with frequent and specific feedback by using diagnostic, formative tests, as well as regularly correcting mistakes students make along their learning path. Assessment in the mastery learning classroom is not used as a measure of accountability but rather as a source of evidence to guide future instruction. A teacher using the mastery approach will use the evidence generated from his or her assessment to modify activities to best serve each student. Teachers evaluate students with criterion-referenced tests rather than norm-referenced tests. In this sense, students are not competing against each other, but rather competing against themselves in order to achieve a personal best.


title: Mastery learning

text: The goal of mastery learning is to have all students reach a prescribed level of mastery (i.e. 80–90% on a test). In order to achieve this, some students will require more time than others, either in practice or instruction, to achieve success. The Time-Achievement Equality Dilemma refers to this relationship between time and achievement in the context of individual differences. If achievement is held constant, time will need to vary. If time is held constant (as with modern learning models), achievement will vary. According to its critics, mastery theory doesn't accurately address this relationship.


title: Mastery learning

text: Bloom's original theory assumes that with practice, the slower learners will become faster learners and the gap of individual differences will disappear. Bloom believes these differences in learning pace occur because of lack of prerequisite knowledge and if all children have the same prerequisite knowledge, then learning will progress at the same rate. Bloom places the blame on teaching settings where students aren't given enough time to reach mastery levels in prerequisite knowledge before moving on to the new lesson. He also uses this to explain why variance in student learning is smaller in the first grade when compared to students in the 7th grade (the smart get smarter, and the slower fall further behind). He referred to this learning rate variance as the Vanishing Point.


title: Mastery learning

text: A four-year longitudinal study by Arlin (1984) found no indication of a vanishing point in students who learned arithmetic through a mastery approach. Students who required extra assistance to learn material in the first year of the study required relatively the same amount of additional instruction in the 4th year. Individual differences in learning rates appear to be impacted by more than just method of instruction, contrary to Bloom's opinions.


title: Mastery learning

text: In studies investigating the effectiveness of mastery learning, control and experimental groups were not always valid. Experimental groups typically consisted of courses that were developed to adhere to the best principles of mastery. However, control groups were sometimes existing classes to use as a comparison. This poses a problem since there was no way to test the effectiveness of the control group to begin with - it could have been a poorly constructed course being compared against a strictly designed mastery course.


title: Mastery learning

text: In studies where the largest effect sizes were found, experimenter-made tests were used to test the mastery levels of students in the experiments. By using tests designed for the experiment, the mastery instruction intervention may have been able to better tailor the learning goals of the class to align with the measurement tool. Conversely, these dramatic effect sizes essentially disappeared when standardized tests were used to measure mastery levels in control and experimental groups


title: Mastery learning

text: There are very few studies that investigate the long-term effects of mastery learning. Many studies included an arbitrary 3-4 week intervention period and results were based on findings from this time period. It's important to consider the length of time students were immersed in a mastery learning program to get a greater understanding of the long-term effects of this teaching strategy.


title: Mastery learning

text: Typical mastery programs involve providing class instruction then testing using reliable tools (i.e. multiple choice unit test). This format of learning may only be beneficial to learners who are interested in surface rather than deep processing of information. This contradicts many of today's modern learning approaches which focus less on direct assessment of knowledge, and more on creating meaningful applications and interpretations of the obtained knowledge (see Constructivism (philosophy of education))


title: Mastery learning

text: The Chicago Mastery Learning Reading program was criticized for a focus on testing. A concern is that children were taught to pass tests without a focus on enduring skills. The duration of the retention of skills was questioned. A love of reading was not promoted. Students rarely read books or stories. Student failure was an aspect of the program design. 80% was required on 80% of the test to pass. This resulted in huge retention levels. Ultimately, the program was not practical to implement.


title: Mastery learning

text: The value of having all children achieve mastery brings into question our general view of success. If the goal of education became having children become experts, grades would become much less varied. That is, you would theoretically have a high school graduating class all with grades above 90%. Universities would have to make selections from a pool of applicants with similar grades, how would admission requirements have to change to account for uniform ratings of intelligence? Would time it took to reach mastery become a new measure of success? These questions about the wider implications of mastery as a new standard raise discussion about its actual value.


title: Mastery learning

text: Mastery Learning has been one of the most highly investigated teaching methods over the past 50 years. While it has been the subject of high criticism, it has also been found to have resounding success when implemented correctly. A meta-analysis by Guskey & Pigott (1988) looked at 46 studies that implemented group-based mastery learning classrooms. Results found consistently positive effects for a number of variables including "student achievement, retention of learned material, involvement in learning activities, and student affect". However, a notable variation was found within student achievement and it was believed this was due mainly to the subject being taught. Courses such as science, probability, and social studies yielded the most consistent positive results, while other subjects were varied.


title: Mastery learning

text: Another large-scale meta analysis conducted by Kulik et al. (1990) investigated 108 studies of mastery programs being implemented at the elementary, secondary, and post-secondary level. Results revealed positive effects in favour of these teaching strategies, with students also reporting positive attitudes toward this style of learning. This study also found mastery programs to be most effective for weaker students.


title: Mastery learning

text: Despite the empirical evidence, many mastery programs in schools have been replaced by more traditional forms of instruction due to the level of commitment required by the teacher and the difficulty in managing the classroom when each student is following an individual course of learning. However, the central tenets of mastery learning are still found in today's teaching strategies such as differentiated instruction and understanding by design.


title: Mastery learning

text: Researchers at Northwestern University led by Drs. Diane Wayne, Jeff Barsuk and William McGaghie pioneered the use of mastery learning in the health professions. In 2006 they investigated mastery learning vs. traditional medical education in advanced cardiac life support techniques and showed that internal medicine resident trainees significantly improved adherence to American Heart Association protocols after mastery training. Subsequent investigations showed improved patient care practices as a result of this rigorous education including reduced patient complications and healthcare costs. These effects on patient care were seen in operating rooms, cardiac catheterization lab, intensive care units and patient floors at a large urban teaching hospital in Chicago. Further study also involved communication skills such as breaking bad news and end of life discussions, and patient self-management skills. In 2020 the Northwestern group published an important textbook entitled Mastery Learning in Health Professions Education. The approach designed by Northwestern investigators is currently in use at other health care institutions and medical schools throughout the US and the world.


title: Mastery learning

text: In 2012, Jonathan Bergmann and Aaron Sams published the book Flip Your Classroom, Reach Every Student in Every Class Every Day. The second half of the book was dedicated to how to implement what they called the Flipped-Mastery Model. They merged mastery learning with flipped learning and saw significant results. The book has spurred many teachers across the world to adopt the Flipped-Mastery approach. Bergmann and Sams show that the logistical problems associated with setting up a mastery learning program are now solved by technology. If teachers have to deliver direct instruction, this can be time-shifted with either an instructional video or a flipped-reading assignment. The issue of multiple assessments is also solved by programs that allow for testing to be much more seamless and less burdensome.


title: Priyanka Kothari

text: Priyanka Kothari, often credited as Nisha Kothari or Amoha, is an actress and model. She has appeared in Bollywood, Telugu, Tamil and Kannada films. She has frequently appeared in Ram Gopal Varma films.


title: Priyanka Kothari

text: Priyanka Kothari was born in West Bengal. She moved to New Delhi while in grade 10 and got her bachelor's degree in physical science from Delhi University at Dyal Singh College, Delhi. She chose chemistry as her father is a chemical businessman, while her mother is a home-maker. She has learnt Kathak for 6 years and attended acting classes with Kishore Namit Kapoor.


title: Priyanka Kothari

text: After college, Kothari became a model and appeared in a number of advertisement campaigns. She appeared in the music video of the remix of Chadti Jawani Meri Chaal Mastani. In 2003, she got her big break through actor Madhavan, who recommended her for an audition in his film after viewing her photographs. She made her acting debut with him in the Tamil film "Jay Jay", credited as Amoga. She made her Bollywood debut in the 2005 film " Sarkar" and then later that same year appeared in "James", directed by Ram Gopal Varma and Rohit Jugraj respectively. "James" turned her into a sex symbol overnight. She then went on to do "The Killer" with Emraan Hashmi. Since then she had appeared in less significant films and roles. She was regularly seen in Ram Gopal Varma's films like "Shiva", "Darna Zaroori Hai", "Aag", in which she played a tapori called Ghungroo, "Darling" and "Agyaat" and also his productions like "Go" and "Stalker". Most of the films were unsuccessful. She made her Sandalwood debut with "Raaj the Showman" opposite Puneeth Rajkumar in 2009 and later did a supporting role in "Dandupalya". She was seen in a Telugu film with Balakrishna, "Okka Magadu" which also bombed and also acted in a film titled "Hari Om".


title: Priyanka Kothari

text: Her only 2011 release was "Bin Bulaye Baraati". In 2013, she appeared in a Malaysian Tamil film titled, "Ops Kossa Dappa 3". She will be seen in the Tamil film "Padam Pesum" and has signed up a Telugu thriller titled "Criminals".


title: Priyanka Kothari

text: Kothari is a member of the International Film And Television Club of Asian Academy of Film & Television. She is the co-founder of Nisha Foundation.


title: Priyanka Kothari

text: In the 2011 West Bengal state assembly elections, she campaigned for Dr Nirmal Majhi, an All India Trinamool Congress candidate contesting from North Uluberia, Kolkata.


title: Priyanka Kothari

text: In 2011, she walked the ramp at Wills Lifestyle India Fashion Week (WIFW), which she describes as her comeback in Bollywood.


title: Pruning

text: Pruning is a horticultural, arboricultural, and silvicultural practice involving the selective removal of certain parts of a plant, such as branches, buds, or roots.


title: Pruning

text: The practice entails the "targeted" removal of diseased, damaged, dead, non-productive, structurally unsound, or otherwise unwanted plant material from crop and landscape plants. Some try to remember the categories as "the 4 D's": the last general category being "deranged". In general, the smaller the branch that is cut, the easier it is for a woody plant to compartmentalize the wound and thus limit the potential for pathogen intrusion and decay. It is therefore preferable to make any necessary formative structural pruning cuts to young plants, rather than removing large, poorly placed branches from mature plants.


title: Pruning

text: In nature, meteorological conditions such as wind, ice and snow, and salinity can cause plants to self-prune. This natural shedding is called abscission.


title: Pruning

text: Specialized pruning practices may be applied to certain plants, such as roses, fruit trees, and grapevines. It is important when pruning that the tree's limbs are kept intact, as this is what helps the tree stay upright. Different pruning techniques may be deployed on herbaceous plants than those used on perennial woody plants. Hedges, by design, are usually (but not exclusively) maintained by hedge trimming, rather than by pruning.


title: Pruning

text: Reasons to prune plants include deadwood removal, shaping (by controlling or redirecting growth), improving or sustaining health, reducing risk from falling branches, preparing nursery specimens for transplanting, and both harvesting and increasing the yield or quality of flowers and fruits.


title: Pruning

text: For arboricultural purposes the unions of tree branches (i.e. where they join together) are placed in one of three categories: collared, collarless or codominant. Regardless of the overall type of pruning being carried out, each type of union is cut in a particular way so that the branch has less chance of regrowth from the cut area and the best chance of sealing over and compartmentalising decay. This is often referred to by arborists as "target cutting".


title: Pruning

text: Branches die off for a number of reasons including sunlight deficiency, pest and disease damage, and root structure damage. A dead branch will at some point decay back to the parent stem and fall off. This is normally a slow process but can be hastened by high winds or extreme temperatures. The main reason deadwooding is performed is safety. Situations that usually demand removal of deadwood include trees that overhang public roads, houses, public areas, power lines, telephone cables and gardens. Trees located in wooded areas are usually assessed as lower risk but assessments consider the number of visitors. Trees adjacent to footpaths and access roads are often considered for deadwood removal.


title: Pruning

text: Another reason for deadwooding is amenity value, i.e. a tree with a large amount of deadwood throughout the crown will look more aesthetically pleasing with the deadwood removed. The physical practice of deadwooding can be carried out most of the year though should be avoied when the tree is coming into leaf. The deadwooding process speeds up the tree's natural abscission process. It also reduces unwanted weight and wind resistance and can help overall balance.


title: Pruning

text: Crown and canopy thinning increases light and reduces wind resistance by selective removal of branches throughout the canopy of the tree.


title: Pruning

text: Crown lifting involves the removal of the lower branches to a given height. The height is achieved by the removal of whole branches or removing the parts of branches which extend below the desired height. The branches are normally not lifted to more than one third of the tree's total height.


title: Pruning

text: Crown lifting is done for access; these being pedestrian, vehicle or space for buildings and street furniture. Lifting the crown will allow traffic and pedestrians to pass underneath safely. This pruning technique is usually used in the urban environment as it is for public safety and aesthetics rather than tree form and timber value.


title: Pruning

text: Crown lifting introduces light to the lower part of the trunk; this, in some species can encourage epicormic growth from dormant buds. To reduce this sometimes smaller branches are left on the lower part of the trunk. Excessive removal of the lower branches can displace the canopy weight, this will make the tree top heavy, therefore adding stress to the tree. When a branch is removed from the trunk, it creates a large wound. This wound is susceptible to disease and decay, and could lead to reduced trunk stability. Therefore, much time and consideration must be taken when choosing the height the crown is to be lifted to.


title: Pruning

text: This would be an inappropriate operation if the tree species’ form was of a shrubby nature. This would therefore remove most of the foliage and would also largely unbalance the tree. This procedure should not be carried out if the tree is in decline, poor health or dead, dying or dangerous (DDD) as the operation will remove some of the photosynthetic area the tree uses. This will increase the decline rate of the tree and could lead to death.


title: Pruning

text: If the tree is of great importance to an area or town, (i.e. veteran or ancient) then an alternative solution to crown lifting would be to move the target or object so it is not in range. For example, diverting a footpath around a tree's drip line so the crown lift is not needed. Another solution would be to prop up or cable-brace the low hanging branch. This is a non-invasive solution which in some situations may be more economical and environmentally friendly.


title: Pruning

text: Reducing the height and or spread of a tree by selectively cutting back to smaller branches and in fruit trees for increasing of light interception and enhancing fruit quality.


title: Pruning

text: A regular form of pruning where certain deciduous species are pruned back to pollard heads every year in the dormant period. This practice is usually commenced on juvenile trees so they can adapt to the harshness of the practice.


title: Pruning

text: Arborists, orchardists, and gardeners use various garden tools and tree cutting tools designed for the purpose, such as hand pruners, loppers, or chainsaws. Additionally in forestry, bush saws are commonly used and these are often attached to poles that reach up to 5-6 m, this is a more efficient way of pruning than with ladders. These bush saws on polls have also been motorized as chainsaws which is even more efficient. Older technology used Billhooks, Kaiser blades and pruning knives. Although still used in some coppicing they are not used so much in commercial forestry due to the difficulty of cutting flush with the stem. Flush cuts lead to good wood, non-flush or bark damaging cuts (which are more likely with a swung blade than a sawed one) put the tree at risk of entry cords from forest pathogens.


title: Pruning

text: Regardless of the various names used for types of pruning, there are only two basic cuts: One cuts back to an intermediate point, called "heading back cut", and the other cuts back to some point of origin, called "thinning out cut".


title: Pruning

text: Removing a portion of a growing stem down to a set of desirable buds or side-branching stems. This is commonly performed in well trained plants for a variety of reasons, for example to stimulate growth of flowers, fruit or branches, as a preventive measure to wind and snow damage on long stems and branches, and finally to encourage growth of the stems in a desirable direction. Also commonly known as "heading-back".


title: Pruning

text: In orchards, fruit trees are often lopped to encourage regrowth and to maintain a smaller tree for ease of picking fruit. The pruning regime in orchards is more planned and the productivity of each tree is an important factor.


title: Pruning

text: Deadheading is the act of removing spent flowers or flowerheads for aesthetics, to prolong bloom for up to several weeks or promote rebloom, or to prevent seeding.


title: Pruning

text: In general, pruning dead wood and small branches can be done at any time of year. Depending on the species, many temperate plants can be pruned either during dormancy in winter, or, for species where winter frost can harm a recently pruned plant, after flowering is completed. In the temperate areas of the northern hemisphere autumn pruning should be avoided, as the spores of disease and decay fungi are abundant at this time of year.


title: Pruning

text: Some woody plants tend to bleed profusely from cuts, such as mesquite and maple. Some callus over slowly, such as magnolia. In this case, they are better pruned during active growth when they can more readily heal. Woody plants that flower early in the season, on spurs that form on wood that has matured the year before, such as apples, should be pruned right after flowering as later pruning will sacrifice flowers the following season. Forsythia, azaleas and lilacs all fall into this category.


title: Ethnologue

text: Ethnologue: Languages of the World (stylized as Ethnoloɠue) is an annual reference publication in print and online that provides statistics and other information on the living languages of the world. It is the world's most comprehensive catalogue of languages. It was first issued in 1951, and is now published by SIL International, an American Christian non-profit organization.


title: Ethnologue

text: "Ethnologue" has been published by SIL International (formerly known as the Summer Institute of Linguistics), a Christian linguistic service organization with an international office in Dallas, Texas. The organization studies numerous minority languages to facilitate language development, and to work with speakers of such language communities in translating portions of the Bible into their languages. Despite the Christian orientation of its publisher, "Ethnologue" isn't ideologically or theologically biased.


title: Ethnologue

text: "Ethnologue" includes alternative names and autonyms, the number of L1 and L2 speakers, language prestige, domains of use, literacy rates, locations, dialects, language classification, linguistic affiliations, typology, language maps, country maps, publication and use in media, availability of the Bible in each language and dialect described, religious affiliations of speakers, a cursory description of revitalization efforts where reported, intelligibility and lexical similarity with other dialects and languages, writing scripts, an estimate of language viability using the Expanded Graded Intergenerational Disruption Scale (EGIDS), and bibliographic resources. Coverage varies depending on languages. For instance, as of 2008, information on word order was present for 15% of entries while religious affiliations were mentioned for 38% of languages. According to Lyle Campbell "language maps are highly valuable" and most country maps are of high quality and user-friendly.


title: Ethnologue

text: "Ethnologue" gathers information from SIL's thousands of field linguists, surveys done by linguists and literacy specialists, observations of Bible translators, and crowdsourced contributions. SIL's field linguists use an online collaborative research system to review current data, update it, or request its removal. SIL has a team of editors by geographical area who prepare reports to Ethnologue's general editor. These reports combine opinions from SIL area experts and feedback solicited from non-SIL linguists. Editors have to find compromises when opinions differ. Most of SIL's linguists have taken three to four semesters of graduate linguistics courses, and half of them have a master's degree. They're trained by 300 PhD linguists in SIL.


title: Ethnologue

text: The determination of what characteristics define a single language depends upon sociolinguistic evaluation by various scholars; as the preface to "Ethnologue" states, "Not all scholars share the same set of criteria for what constitutes a 'language' and what features define a 'dialect'." "Ethnologue" historically followed general linguistic criteria, which are based primarily on mutual intelligibility. Shared language intelligibility features are complex, and usually include etymological and grammatical evidence that is agreed upon by experts. "Ethnologue" codes were used as the base to create the new ISO 639-3 international standard. Since 2007, "Ethnologue" relies only rely on this standard, administered by SIL International, to determine what is listed as a language. Criteria used to be defined as a language are and mutual intelligibility and the existence or absence of a common literature or ethnolinguistic identity.


title: Ethnologue

text: In addition to choosing a primary name for a language, "Ethnologue" provides listings of other name(s) for the language and any dialects that are used by its speakers, government, foreigners and neighbors. Also included are any names that have been commonly referenced historically, regardless of whether a name is considered official, politically correct or offensive; this allows more complete historic research to be done. These lists of names are not necessarily complete.


title: Ethnologue

text: "Ethnologue" was founded in 1951 by Richard S. Pittman and was initially focused on minority languages, to share information on Bible translation needs. The first edition included information on 46 languages. Hand-drawn maps were introduced in the fourth edition (1953). The seventh edition (1969) listed 4,493 languages. In 1971, "Ethnologue" expanded its coverage to all known languages of the world.


title: Ethnologue

text: "Ethnologue" database was created in 1971 at the University of Oklahoma under a grant from the National Science Foundation. In 1974 the database was moved to Cornell University. Since 2000, the database has been maintained by SIL International in their Dallas headquarters. In 1997 (13th edition), the website became the primary means of access.


title: Ethnologue

text: In 1984, "Ethnologue" released a three-letter coding system, called an 'SIL code', to identify each language that it described. This set of codes significantly exceeded the scope of other existing standards, e.g. ISO 639-1 and ISO 639-2.


title: Ethnologue

text: The 14th edition, published in 2000, included 7,148 language codes. In 2002, "Ethnologue" was asked to work with the International Organization for Standardization (ISO) to integrate its codes into a draft international standard. "Ethnologue" codes have then been adopted by ISO as the international standard, ISO 639-3. The 15th edition of "Ethnologue" was the first edition to use this standard. This standard is now administered separately from Ethnologue. SIL International is the registration authority for languages names and codes, according to rules established by ISO. Since then "Ethnologue" relies on the standard to determine what is listed as a language. In only one case, "Ethnologue" and the ISO standards treat languages slightly differently. ISO 639-3 considers Akan to be a macrolanguage consisting of two distinct languages, Twi and Fante, whereas "Ethnologue" considers Twi and Fante to be dialects of a single language (Akan), since they are mutually intelligible. This anomaly resulted because the ISO 639-2 standard has separate codes for Twi and Fante, which have separate literary traditions, and all 639-2 codes for individual languages are automatically part of 639–3, even though 639-3 would not normally assign them separate codes.


title: Ethnologue

text: In 2014, with the 17th edition, "Ethnologue" introduced a numerical code for language status using a framework called EGIDS (Expanded Graded Intergenerational Disruption Scale), an elaboration of Fishman's GIDS (Graded Intergenerational Disruption Scale). It ranks a language from 0 for an international language to 10 for an extinct language, i.e. a language with which no-one retains a sense of ethnic identity.


title: Ethnologue

text: In 2015, SIL's funds decreased and in December 2015, "Ethnologue" launched a metered paywall to cover its cost, as it is financially self-sustaining. Users in high-income countries who wanted to refer to more than seven pages of data per month had to buy a paid subscription. The 18th edition released that year included a new section on language policy country by country.


title: Ethnologue

text: As of 2017, "Ethnologue"'s 20th edition described 237 language families including 86 language isolates and six typological categories, namely sign languages, creoles, pidgins, mixed languages, constructed languages, and as yet unclassified languages.


title: Ethnologue

text: The early focus of the Ethnologue was on native use (L1) but was gradually expanded to cover L2 use as well.


title: Ethnologue

text: In 2019, "Ethnologue" disabled trial views and introduced a hard paywall to cover its nearly $1 million in annual operating costs (website maintenance, security, researchers, and SIL's 5,000 field linguists). Subscriptions start at $480 per person per year, while full access costs $2,400 per person per year. Users in low and middle-income countries as defined by the World Bank are eligible for free access. Subscribers are mostly institutions: 40% of the world's top 50 universities subscribe to "Ethnologue", and it is also sold to business intelligence firms and Fortune 500 companies. The introduction of the paywall was harshly criticized by the community of linguists who rely on "Ethnologue" to do their work and cannot afford the subscription The same year, "Ethnologue" launched its contributor program to fill gaps and improve accuracy, allowing contributors to submit corrections and additions and to get a complimentary access to the website. "Ethnologue"'s editors gradually review crowdsourced contributions before publication. As 2019 was the International Year of Indigenous Languages, this edition focused on language loss: it added the date when last fluent speaker of the language died, standardized the age range of language users, and improved the EGIDS estimates.