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Tumbuka people

The Tumbuka (or, Kamanga, Batumbuka and Matumbuka) is a Bantu ethnic group found in Malawi, Zambia and  Tanzania. Tumbuka is classified as a part of the Bantu language family, and with origins in a geographic region between the Dwangwa River to the south, the North Rukuru River to the north, Lake Malawi to the east, and the Luangwa River. They are found in the valleys near the rivers, lake as well as the highlands of Nyika Plateau, where they are frequently referred to as Henga although this is strictly speaking the name of a subdivision.

Historically, the Tumbuka can be subdivided into two groups: the Tumbuka of Luba, who are the original group from Luba Kingdom, and the Tumbuka who emerged through intermarriages with non-Tumbuka neighbours. The neighbours came to settle in the Tumbuka territory long after the Tumbuka formed their kingdom. These are Tumbuka Chewa, Tumbuka Senga, Tumbuka Mlowoka, and Tumbuka Ngoni. In reality and culturally they are all Tumbuka. There are also many smaller subsidiary Tumbuka groups by origin found mainly in the north-western corner of their original kingdom between Kalonga and Isoka. Many of these belong to the Kalonga wa Nkhonde segment of the Mulonga Mbulalubilo Tumbuka.

To set record straight, the Tumbuka tribe was one of the small tribes who originated from Luba in what is currently known as Democratic Republic of the Congo. That was before any formal government setup and they had been staying there for hundreds of years after breaking away from the Bantu tribes in upper central Africa.

The Tumbuka tribe and other small tribes were driven out of Luba by a warrior tribe known as Kongolo tribe the tribe that merged with the tribes that remained in Luba after they tried to subdue the Tumbuka people and failed.

Demography and language
Various estimates suggest that over two million Tumbuka speakers live in north Malawi, northeast Zambia and Tanzania. Ethnologue estimates a total of 2,546,000 Tumbuka speakers in 2000. However, Ember et al. estimate that about an additional million Tumbuka people live in central and southern African countries such as Tanzania because of the diffusion of Tumbuka people as migrant labor.

The Tumbuka language, also called chiTumbuka, is a Bantu language, similar to many other Bantu languages in structure and vocabulary. It is classified as a central Bantu language in the Niger-Congo family, and it has many dialects. The Tumbuka are collectively known as ŵaTumbuka and one is called "mutumbuka" meaning one of the Tumbuka tribe. The Tumbuka language is closely related to the Tonga language and it has been suggested that they originally formed a single group of mutually intelligible dialects until different missionaries treated two such dialects as the standard Tumbuka and Tonga languages.

Before a British protectorate was created over Nyasaland, there were many ethnic groups in what is now Malawi's Northern Region including a substantial group culturally-related people, scattered widely and loosely organized under largely autonomous village headmen who spoke dialects of the Tumbuka language. Missionaries in the late 19th century standardised these languages into a relatively small number of groups, and chose the standardised Tumbuka language as the usual medium for teaching in the north of the country, in preference to the Ngoni, Tonga or Ngonde languages which were also prominent in the area. By the start of the 20th century, the Ngoni and Ngonde languages were in decline, although Tonga was more resilient.

In 1968, Tumbuka was abolished as an official language, as a medium of instruction and in examinations, and the secondary school entrance system was manipulated to assist candidates from the Central Region and disadvantage those from the Northern Region. Some of those that objected to the ban on the use of Tumbuka were arrested or harassed but both the Church of Central Africa Presbyterian and the Catholic Church continued to preach and use religious texts in Tumbuka in the Northern Region.

After the advent of multi-party democracy, Tumbuka language programmes began to be broadcast on national radio in 1994 but a 1996 proposal for the reintroduced of Tumbuka as a medium for teaching in the first four years of compulsory education has not been fully implemented. One effect of the failure to restore the Tumbuka language as the standard language of the Northern Region is that speakers of other languages in the region, the Tonga, Ngonde and even the little-spoken Ngoni language are now seeking parity with Tumbuka.

History

The Tumbuka probably entered the area between the Luangwa valley and northern Lake Malawi in the 15th century. At the start of the 18th century, they formed a number of groups, of which the Henga was one, living in small, independent communities without a central organisation, spread thinly over this area. By the mid-18th century, traders dressed “as Arabs”, although coming from the Unyamwezi region of what is now Tanzania were involved in trading for ivory and to some extent slaves as far inland as the Luangwa valley. They formed alliances with groups of Henga, and their leader established the Chikulamayembe Dynasty ruling a federation of small chiefdoms. However, by the 1830s, this Chikulamayembe dynasty was in decline and the area reverted to a state of political and military disorganisation

The large elephant herds of the region attracted groups of coastal Swahili ivory hunters and traders followed in the colonial era by European ivory traders. In the 1840s, Swahili Arabs entered northern Malawi region, with Jumbe Salim bin Abdallah establishing a trading centre at Nkhotakota near Lake Malawi. Jumbe Abdallah's trade in slaves to satisfy the demand for slaves on Zanzibar plantations of cloves and for the Middle East triggered raids and violence against the Tumbuka people. A male slave was known as muzga or kapolo, while a chituntulu meant a young female slave.

The rising demand for ivory in the European market led to conflicts to control the export trade, resulting in greater social distinctions and politically centralized chiefdoms among the Tumbuka. These ruling groups collapsed around 1855, when the highly militarized warriors of the Ngoni ethnic group from South Africa arrived seeking agricultural slaves and recruits, in addition to those acquired by the Swahili traders.

The Ngoni of Mbelwa (also known as M'mbelwa) were a branch of Zwangendaba's Ngoni, which began its migration from South Africa between 1819 and 1822, eventually reaching southern Tanzania and remained there until Zwangendaba's death in the mid-1840s. After this, his followers split into several groups, one of which under his son Mbelwa settled permanently in what is now the Mzimba district of northern Malawi around 1855. Mbelwa's Ngoni treated the Henga as subjects, exacting tribute and taking captives through raiding. These captives were rarely sold to the Swahili traders, but retained as unfree agricultural workers or enrolled in Ngoni regiments. Some of these Henga conscript soldiers revolted and fled north, entering Ngonde territory around 1881, where the Ngonde settled them as a buffer against their enemies.

The Swahili traders had built most of their stockades in the area in which the Henga had been settled and, after the African Lakes Company set up a trading base at Karonga, and as the threat of Ngoni raids had declined, the usefulness of Henga and Swahili to the Ngonde state lessened. Both groups were aliens among the Ngonde majority, and were suspicious of cooperation between the company and Ngonde, so they allied with each other. The alliance of the Swahili and the Henga faced a rival alliance between the Ngonde and the African Lakes Company which eventually led to the so-called Karonga War between them, a series of skirmishes and sieges of stockades between 1887 and 1889

The Ngoni invasion led initially to a devastation of the Tumbuka people, through the death, destruction, loss of family members, abandonment of the settled valleys, and disruption of their traditional agricultural methods as the Tumbuka people hid in mountains, small islands, and marshes to escape from the violence associated with large-scale human raids and elephant hunting. It also led to intermingling and intermarriage between the people of Tumbuka and the Ngoni cultures.

The British explorer David Livingstone wrote about the Lake Malawi region in 1858, mentioning slavery of the Tumbuka people both to the export of slaves to satisfy the Arab demand as well as domestic slavery in the form of "debt settlement". Christian missionaries arrived in this region in the 1870s.

In 1895 British-led forces defeated the slave trader Mlozi at Karonga, ending the slave trade there. Although a British protectorate over what is now Malawi was proclaimed in 1891, the Northern Ngoni only finally accepted British rule in 1904, when the Tumbuka people ceased to be their vassals or returned from where they had taken refuge to their original homes. A Chikulamayembe paramount chief was restored to office in 1907, and Tumbuka culture reasserted itself. The education provided by Scottish-run missions at several sites in the Northern Region of Nyasaland was more eagerly embraced by the Tumbuka and Tonga peoples, whose earlier social organisation and religion had suffered from the attacks of slave raiders and Ngoni, than by the Ngoni and Ngonde peoples, who retained these institutions intact, and more mission schools were opened among the Tumbuka than any other group in Nyasaland. The education that these schools provided not only reached a greater numbers of pupils but was also superior to that found in other parts of the protectorate, although other Scottish missionaries at Blantyre Mission also provided educational advancement for some southerners. Those that these missions trained became an educated African elite, who found employment as teachers, in the colonial civil service or in commerce, and whose political aim was African advancement to higher positions in the administration. In contrast, the Yao people in the south, who included many Muslims excluded from Christian education, and Chewa people in the centre, where fewer missions had been founded, were less affected by these political aspirations.

In the pre-colonial period, the Tumbuka people, like most of the people of what became Nyasaland relied on subsistence farming to support their families. During the first three decades of colonial rule, commercial agriculture developed both on European-owned states and the smallholdings of African peasants in the southern and central parts of the protectorate. However, attempts to introduce commercial agriculture into the Northern Region were frustrated by a lack of suitable crops and high transport costs arising from its distance from the available markets. As early as the 1880s, Tumbuka and Tonga men began to leave the region to work as porters and estate workers in the Southern Region of Nyasaland and, once those Tumbuka that had received a mission education reached adulthood, they travelled to Southern Rhodesia and South Africa where their literacy and numeracy commanded much high wages than they could earn in within Nyasaland. Although the colonial government was concerned about the scale of labour migration, it was a virtual necessity for many in the north of the country where there were few alternatives besides subsistence agriculture. The colonial government were concerned that the Tumbuka-speaking areas had become the "Dead North" of the country but only invested small amounts in developing infrastructure or promoting commercial crops

One supporter of the underdevelopment hypothesis blames the impoverishment and stagnation of Tumbuka-speaking areas on a step-by-step process that started in the middle of the 19th century when the Indian Ocean ivory and slave trade created a demand for imported goods and prompted social differentiation within their traditional societies. This was worsened by the mid-19th century incursion of Ngoni people, which caused a further loss of status of among the Tumbuka people, who become Ngoni serfs or refugees with limited access to land. Ngoni agricultural practices of shifting or slash-and-burn cultivation and overstocking cattle were said to impoverish the soil and promoted the spread of the tsetse fly. According to Vail, the effect of the Ngoni invasions was exacerbated during the period of colonial rule up to 1939 as, at best, local African men in the "Dead North" of Nyasaland had little choice but to become labour migrants and, at worst, their recruitment for the mines, farms and other employers of Southern Rhodesia and South Africa was forced.

Much of Vail's account of environmental degradation in Northern Nyasaland is based on the views of 19th century missionaries who regarded Ngoni farming practices as environmentally destructive, wasteful and therefore morally wrong, although modern agronomists believe shifting cultivation may be efficient and sympathetic to the environment. His suggestions that both the recruitment of labour and the consumption of foreign goods was forced on the Tumbuka, seem overstated, and the first labour migrancy from this area was entirely voluntary and, in later years, was more often disapproved of by the Nyasaland government than promoted by them. Since independence, the economic conditions of the Tumbuka people have remained largely unchanged, their political power limited given the numerous ethnic groups in this region of Africa.

Levi Mumba, Charles Chinula and many of the leading figures in organisations that later became part of Nyasaland African Congress, or of Congress itself, were Tumbuka-speaking northerners or graduates of Blantyre Mission. This movement ultimately gained independence for Malawi in 1964.

After in 1963, in preparation for independence, Tumbuka speakers took a majority of the ministerial posts in the government of Hastings Banda. Shortly after independence, in the 1964 Cabinet Crisis, the demands of these ministers for more rapid Africanisation, a key demand of the mission-educated elite, led to their resignation or sacking and in many cases their exile. In the aftermath of this, Banda purged their supporters and other Tumbuka speakers from positions of influence and replaced them with Chewa nominees from the Central Region, at the same time promoting the Chewa culture as the only authentic Malawian culture.

Society, religion and culture
Even before colonial rule was established, Christian missionaries arrived amongst Tumbuka people. Thomas Cullen Young was one of the first missionaries to publish on the culture in Notes on the history of the Tumbuka-Kamanga peoples in the Northern Province of Nyasaland. To help the conversion process, hymnbook and mythologies of Christianity were written into Tumbuka language, into a Tumbuka hymnbook. In contemporary times, the Tumbuka people are officially Christian, but they retain their traditional beliefs and folklores.

The Tumbuka people have had a sophisticated traditional religion. It included the concept of a supreme creator called Chiuta symbolizing the sun, who Tumbuka faith holds was "self created and all knowing". This religious belief has yield a rich mythology filled with morals. In a manner similar to neighboring regions of Africa, the Tumbuka have also revered ancestor worship, spirit possession, witchcraft and similar practices. Their spirit possession and witchcraft is related to folk therapies for illnesses. This practice is locally called Vimbuza, includes a therapeutic dance performed by those possessed, and this is a part of modern syncretistic Christianity observed by the Tumbuka people.

The Tumbuka people have been rural, living in villages or dispersed agnatically related clusters of rectangular thatched houses. A circular thatched granaries and kitchen would traditionally be a part of each household. The male members would spend their time mostly in a part of the house called Mpara and females in Ntanganini. In the crop season, family members dispersed, sometimes residing in isolated thatched houses near the cultivated land.

In the contemporary era, the primary staple crops of the Tumbuka people are maize, cassava, millet, and beans, along with a variety of pumpkins, vegetables, and fruits such as bananas and oranges as supplements often grown by Tumbuka women. Men have tended to be migrant workers. In the past, the farming was done manually using hoes. During the colonial rule, ox-drawn plows were introduced. Citemene, or slash and burn agriculture by small farmers is a modern era practice and continues among the Tumbuka people.

Vimbuza
Vimbuza (pl. of Chimbuza) is a term used among the Tumbuka-speaking peoples of northern Malawi and eastern Zambia to describe several classes of possessive spirits, the embodied states of illness they produce in a person, and the therapeutic drumming, music, dance, and ritual that is performed to remedy the symptoms. As a cultural practice, Vimbuza is a local version of a more widespread therapeutic complex known as ngoma, which is found throughout much of central and southern Africa and has been the focus of important scholarship by John M. Janzen and others, and even earlier by Victor Turner in his writings about Ndembu drums of affliction.

Vimbuza, in the traditional Tumbuka people's belief, are category of spirits that cause illnesses, a concept that according to James Peoples and Garrick Bailey is similar to "bodily humours" in early European texts. The Vimbuza causes imbalance in the hot and cold forces within the human body, whose healing process, to Tumbuka people, is a ritual dance with singing and music. The UNESCO inscribed the ritualistic Vimbuza dance as Intangible Cultural Heritage of Humanity in 2008. The musical instruments that accompany the Vimbuza includes a Ng’oma or “drums of affliction”. A healer diagnoses spirit possession, and with the patient undertakes dance healing ritual treatment over several weeks or months.The dance tries to bring the patient into a trance, while the songs call the spirits to help. Men participate by creating drum rhythms that are spirit-specific and sometimes as the healer. Vimbuza, states UNESCO, creates a "space for patients to dance their disease”.

The Vimbuza tradition is effectively a set of practices and beliefs of which the Vimbuza dance is part; is a traditional healing procedure, to cure psychological illnesses as well as exorcise demons. In some places it is specifically called mkhalachitatu Vimbuza. Mkhalachitatu Vimbuza is one of the names given to Vimbuza dances performed as an exorcism rite when one is possessed by demons or evil spirits.

It is predominantly performed in Rumphi, but has spread to Mzimba, Karonga, Kasungu and other districts. The dance is also performed in Nkhata Bay where it is called masyabi and here it incorporates indigenous variations.

Zengani Traditional Ceremony
Zengani Traditional Ceremony is a traditional annual event held for Tumbuka speakers of Lundazi, Chasefu and Lumezi District in Eastern Province of Zambia, typically in October. Zengani means bringing together two tribes of the Ngoni and Tumbuka speaking people. During the ceremony people are expected to be entertained to various traditional dances like ingoma, vimbuza, muganda, and chiwoda. Traditional leaders such as chiefs attend the events.

title: Tumbuka people


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Talk:Basic block

Conservative concept
Yaronf,

Your edits are okay, but you've made the concept more conservative and blurred the idea that basic blocks are intraprocedural entities (CFG edges don't leave the procedure). Generally, we allow function calls in the middle of basic blocks, as long as we know they will return; exceptions and continuations can mess this up. If you concur I'd like to revert some of your changes.

Derrick Coetzee 02:12, 29 Feb 2004 (UTC)

 * Hi Derrick,

 * When performing static code analysis, you rarely have complete information about who's calling a certain procedure. More precisely, this is a question of whether procedure addresses are observeable externally, e.g. through a linker-generated symbol table for dynamic loading. So often you have to assume that the procedure's boundary is also the start of a basic block. You can certainly optimize across function calls, but in such cases you are optimizing across basic blocks! Dynamic :analysis is different for example in a trace cache you can have a single trace with code from different :procedures.

 * Also, exceptions are associated with instructions at this level, not with functions.

 * BTW, I used "instruction" while you're using "statement". The former may prevent confusion with high-level language statements, but in any case, the article should only use one of the terms for consistency.

 * Yaronf 12:15, Feb 29, 2004 (UTC)

First use of the term
The material on this page is fine, but it would be nice if it referenced the earliest use of "basic block" (that I know if) which is J. Backus 1957 paper cited in the (current as of 2010-03-04) footnote 7 of http://en.wikipedia.org/wiki/Fortran. Anyone feel responsible for this page? —Preceding unsigned comment added by 75.18.168.242 (talk) 22:34, 4 March 2010 (UTC)

Clarifications
The code may be source code, assembly code or some other sequence of instructions.

Well... Assembly code is just a special case of source code, isn't it? I suggest to remove that sentence, and add source code at the very beginning of the article.

"dominates", or always executes before

The or gives the impression it's an alternative: either it's dominating, or it executes before. If I understand correctly the topics, it's just a rephrasing. I suggest to replace or with i.e. or parentheses to make that clear.

--MathsPoetry (talk) 02:03, 11 September 2011 (UTC)

Bad/incomplete short definitions
It's actually kinda hard to find sources which don't mess up when giving a one-liner definition of BB. I found some good ones, which I'm going to add to the article, but for the benefit of future textbook (and even research paper) writers, here is how some short ones (actually found in publications out there) are bad/incomplete:

just SESE
I.e. single-entry, single-exit. Well, obviously Dijkstra could tell you that an  is SESE, but this is clearly not a single BB. Entry/exit point is a notion with respect to the outside of the program/block/construct, not from the inside, i.e. SESE does not prohibit, with the usual meaning of "entry point" and "exit point", internal jumps/branches inside the block as long as those jump points aren't referenced from outside the program/block/construct.

instructions execute "together"
... or, more wordily stated "if one is executed then all are executed". This is more arguable that is actually wrong, but it lacks some timing/repetition info. Consider:

Assuming no external jumps into the code fragment besides to the first instruction, then if one of the instructions above is executed, then all are, but some are executed more than once! This example is actually inspired from the Böhm-Jacopini proof; it uses a variable (i) to encode flow control within the fragment. (You can obviously drop the whole "if" part, but I added it for clarity.)

It is more arguable that is actually a bad/incomplete definition, because you can interpret "if one is executed then all are executed" as implying that when   executes [a second time], then i = 0 must also execute [a second time]. "if one is executed then all are executed" lacks an explicit time frame info for when the "then" part is supposed to happen; note that it's not enough for them to execute "together" even within a single call (entry/exit sequence) to the block. So a complete/unambiguous formulation starting with this expression is "if one is executed then all are executed before any one of them may be executed again, [i.e. a second time]". Which is of course a rather cumbersome way to say. The issue here is that you're really trying to express a temporal logic constraint using only classical logic, so it is going to sound awkward/imprecise.

HTH. Intllgnt sgn unlss cmpltly knwn (talk) 04:47, 19 July 2014 (UTC)

Adding an example?
To the previous redactors: would it be clever to put an example of "basic block", a textual description is not concrete.

Relation to Program Structure Tree and single-entry-single-exit ?
Are https://en.wikipedia.org/wiki/Single-entry_single-exit and this article equivalent? Intellec7 (talk) 09:14, 4 July 2020 (UTC)

Suggesting a change in the output definition of Creation algorithm
Shouldn't the "statement" in the output definition of Creation algorithm be "instruction"?

Input: A sequence of instructions (mostly three-address code).

Output: A list of basic blocks with each three-address statement in exactly one block.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Basic block


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Wikipedia talk:Selected anniversaries/March 7

Future candidates: Bloody Sunday (1965) (a stub as of February 28, 2004)
 * Today 'Bloody Sunday (1965)' redirects to Selma to Montgomery marches, a fairly decent article on the events of the series of march attempts, including the first. I'd like to see it on selected anniversaries, especially this year for the 40th anniversary. (I'd fit it in, but the page is locked.) -- ke4roh 17:57, Mar 4, 2005 (UTC)
 * Posted. Thank you for your suggestion, ke4roh. :-) -- PFHLai 07:16, 2005 Mar 7 (UTC)

Campbell v. Acuff-Rose Music
I'm a law student (doing intellectual property no less) and even I don't think this is important enough to be here! Mangostar (talk) 03:59, 7 March 2008 (UTC)

Napoleon's Title
As pointed out by Shipman7 on Talk:March 7, Napoleon Bonaparte did not crown himself Napoleon I until he became emporer, which happened on December 2, 1804, according to the Napoleon I of France article. Kentholke (talk) 19:44, 7 March 2009 (UTC)

2012 notes
— howcheng  {chat} 06:49, 6 March 2012 (UTC)
 * Rescued from Ineligible (unused): Battle of Pea Ridge
 * Omitted: Marcus Aurelius/Lucius Verus, Daniel Webster (ineligible—maintenance), José Paranhos, Viscount of Rio Branco, William, Prince of Albania, Kepler (spacecraft)
 * Included: Étienne Tempier (2nd appearance, last in 2008; rescued from Ineligible), North Carolina State University (2nd appearance, last in 2010), Operation Truong Cong Dinh (first appearance), We Are the World (first appearance), 2009 Massereene Barracks shooting (first appearance)

2013 notes
— howcheng  {chat} 02:25, 6 March 2013 (UTC)
 * Omitted: Étienne Tempier; North Carolina State University; We Are the World; 2009 Massereene Barracks shooting
 * Included: Sol Invictus (first appearance); Battle of Pea Ridge (7th appearance, last in 2009); José Paranhos, Viscount of Rio Branco (2nd appearance, last in 2011); Kepler (spacecraft) (2nd appearance, last in 2011)
 * Repeats: Operation Truong Cong Dinh (2nd consecutive appearance, 2 total)

2014 notes
— howcheng  {chat} 11:03, 6 March 2014 (UTC)
 * Deleted: Klaus Fuchs (moved to March 1)
 * Omitted: Sol Invictus; Battle of Pea Ridge; Operation Truong Cong Dinh; Kepler (spacecraft)
 * Included: Marcus Aurelius/Lucius Verus (both: 8th appearance, last in 2011); Étienne Tempier (3rd appearance, last in 2012); William, Prince of Albania (2nd appearance, last in 2011); Selma to Montgomery marches (5th appearance, last in 2010; rescued from Ineligible)
 * Repeats: José Paranhos, Viscount of Rio Branco (2nd consecutive appearance, 3 total)

2015 notes
— howcheng  {chat} 06:58, 5 March 2015 (UTC)
 * Omitted: Marcus Aurelius/Lucius Verus; Étienne Tempier; William, Prince of Albania
 * Included: Sol Invictus (2nd appearance, last in 2013); Ludendorff Bridge (3rd appearance, last in 2010; rescued from Ineligible; 70th anniversary); We Are the World (2nd appearance, last in 2012; 30th anniversary)
 * Repeats: José Paranhos, Viscount of Rio Branco (3rd consecutive appearance, 4 total); Selma to Montgomery marches (2nd consecutive appearance, 6 total; 50th anniversary)

2016 notes
— howcheng  {chat} 09:17, 5 March 2016 (UTC)
 * Omitted: Sol Invictus; José Paranhos, Viscount of Rio Branco; Ludendorff Bridge; Selma to Montgomery marches
 * Included: Étienne Tempier (4th appearance, last in 2014); Daniel Webster (2nd appearance, last in 2011; rescued from Ineligible); Remilitarization of the Rhineland (3rd appearance, last in 2010; 80th anniversary); 2009 Massereene Barracks shooting (2nd appearance, last in 2012)
 * Repeats: We Are the World (2nd consecutive appearance, 3 total)

2017 notes

 * Moved to Ineliglble: Sol Invictus (maintenance); William, Prince of Albania (maintenance)
 * Omitted: Étienne Tempier (ineligible—maintenance); Daniel Webster; Remilitarization of the Rhineland; 2009 Massereene Barracks shooting
 * Included: Ottoman–Venetian War (1570–1573) (first appearance); Battle of Pea Ridge (8th appearance, last in 2013); José Paranhos, Viscount of Rio Branco (5th appearance, last in 2015); Battle of Remagen (first appearance)
 * Repeats: We Are the World (3rd consecutive appearance, 4 total)

2018 notes
— howcheng  {chat} 17:31, 7 March 2018 (UTC)
 * Moved to Ineligible: North Carolina State University (maintenance)
 * Omitted: Ottoman–Venetian War (1570–1573); Battle of Pea Ridge; Battle of Remagen; We Are the World; Reinhard Heydrich; Divine (performer); Cool Papa Bell
 * Included: Sol Invictus (3rd appearance, last in 2015; rescued from Ineligible); Condemnations of 1210–1277 (first appearance; blurb previously featured Étienne Tempier, which is currently ineligible and is making its 5th appearance, last in 2016); Daniel Webster (3rd appearance, last in 2016); SS Kaiser Wilhelm der Grosse (first appearance); Operation Truong Cong Dinh (3rd appearance, last in 2014); Ludwig Mond (first appearance); Boris Kustodiev (first appearance); E. Pauline Johnson (first appearance)

2019 notes
— howcheng  {chat} 17:20, 7 March 2019 (UTC)
 * Moved to Ineligible: Battle of Pea Ridge (maintenance)
 * Omitted: Sol Invictus; Condemnations of 1210–1277; Daniel Webster; SS Kaiser Wilhelm der Grosse; Operation Truong Cong Dinh; Ludwig Mond; Boris Kustodiev; E. Pauline Johnson
 * Included: Battle of Craonne (first appearance); José Paranhos, Viscount of Rio Branco (6th appearance, last in 2017); German submarine U-47 (1938) (2nd appearance, last in 2014; previously appeared on October 14); We Are the World (5th appearance, last in 2017); 2009 Massereene Barracks shooting (3rd appearance, last in 2016; 10th anniversary); Robert Townsend (spy) (first appearance); Mochtar Lubis (first appearance); Nicolas Dupont-Aignan (first appearance)

2020 notes
— howcheng  {chat} 16:19, 9 March 2020 (UTC)
 * Moved to Ineligible: E. Pauline Johnson (maintenance)
 * Omitted: Battle of Craonne; José Paranhos, Viscount of Rio Branco; German submarine U-47 (1938); We Are the World; 2009 Massereene Barracks shooting; Robert Townsend (spy); Mochtar Lubis; Nicolas Dupont-Aignan
 * Included: Perpetua and Felicity (first appearance); Condemnations of 1210–1277 (2nd appearance, last in 2018); Ottoman–Venetian War (1570–1573) (2nd appearance, last in 2017); SS Kaiser Wilhelm der Grosse (2nd appearance, last in 2018); Battle of Remagen (2nd appearance, last in 2017; 75th anniversary); Selma to Montgomery marches (7th appearance, last in 2015); Ewald Christian von Kleist (first appearance); Harriet Jacobs (first appearance); Hideki Noda (first appearance)

2021 notes
— howcheng  {chat} 07:51, 9 March 2021 (UTC)
 * Omitted: Condemnations of 1210–1277; Ottoman–Venetian War (1570–1573); SS Kaiser Wilhelm der Grosse; Battle of Remagen; Selma to Montgomery marches; Ewald Christian von Kleist; Harriet Jacobs; Hideki Noda
 * Included: Sol Invictus (4th appearance, last in 2018; 1700th anniversary); Daniel Webster (4th appearance, last in 2018); José Paranhos, Viscount of Rio Branco (7th appearance, last in 2019); German submarine U-47 (1938) (3rd appearance, last in 2019); Massereene Barracks shooting (4th appearance, last in 2019); Boris Kustodiev (2nd appearance, last in 2018); Nicolas Dupont-Aignan (2nd appearance, last in 2019); Cool Papa Bell (3rd appearance, last in 2017; 30th anniversary)

2022 notes
— howcheng  {chat} 05:00, 8 March 2022 (UTC)
 * New articles (unused): Increase A. Lapham; Tom Acker
 * Omitted: Sol Invictus; Daniel Webster; José Paranhos, Viscount of Rio Branco; German submarine U-47 (1938); Massereene Barracks shooting; Boris Kustodiev; Nicolas Dupont-Aignan; Cool Papa Bell
 * Included: Condemnations of 1210–1277 (3rd appearance, last in 2020); Battle of Craonne (2nd appearance, last in 2019); We Are the World (6th appearance, last in 2019); Kepler space telescope (3rd appearance, last in 2013; rescued from Ineligible); Heraclianus (first appearance); Harriet Jacobs (2nd appearance, last in 2020; 125th anniversary); Viv Richards (first appearance; 70th birthday)


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Adenoid

In anatomy, the pharyngeal tonsil, also known as the nasopharyngeal tonsil or adenoid, is the superior-most of the tonsils. It is a mass of lymphoid tissue located behind the nasal cavity, in the roof and the posterior wall of the nasopharynx, where the nose blends into the throat. In children, it normally forms a soft mound in the roof and back wall of the nasopharynx, just above and behind the uvula.

The term adenoid is also used to represent adenoid hypertrophy, the abnormal growth of the pharyngeal tonsils.

Structure
The adenoid is a mass of lymphoid tissue located behind the nasal cavity, in the roof and the posterior wall of the nasopharynx, where the nose blends into the throat. The adenoid, unlike the palatine tonsils, has pseudostratified epithelium. The adenoids are part of the so-called Waldeyer ring of lymphoid tissue which also includes the palatine tonsils, the lingual tonsils and the tubal tonsils.

Development
Adenoids develop from a subepithelial infiltration of lymphocytes after the 16th week of embryonic life. After birth, enlargement begins and continues until ages 5 to 7 years.

Function
Part of the immune system, adenoids trap and recognize pathogens such as bacteria and viruses. In response, the adenoid produces T cells and B cells to combat infection, contributing to the synthesis of IgA immunoglobulins, assisting in the body's immunologic memory.

Microbiome
Species of bacteria such as lactobacilli, anaerobic streptococci, actinomycosis, Fusobacterium species, and Nocardia are normally present by 6 months of age. Normal flora found in the adenoid consists of alpha-hemolytic streptococci and enterococci, Corynebacterium species, coagulase-negative staphylococci, Neisseria species, Haemophilus species, Micrococcus species, and Stomatococcus species.

Enlargement
An enlarged adenoid, or adenoid hypertrophy, can become nearly the size of a ping pong ball and completely block airflow through the nasal passages. Even if the enlarged adenoid is not substantial enough to physically block the back of the nose, it can obstruct airflow enough so that breathing through the nose requires an uncomfortable amount of work, and inhalation occurs instead through an open mouth. The enlarged adenoid would also obstruct the nasal airway enough to affect the voice without actually stopping nasal airflow altogether.

Symptomatic enlargement between 18 and 24 months of age is not uncommon, meaning that snoring, nasal airway obstruction and obstructed breathing may occur during sleep. However, this may be reasonably expected to decline when children reach school age, and progressive shrinkage may be expected thereafter.

Adenoid facies
Enlargement of the adenoid, especially in children, causes an atypical appearance of the face, often referred to as adenoid facies. Features of adenoid facies include mouth breathing, an elongated face, prominent incisors, hypoplastic maxilla, short upper lip, elevated nostrils, and a high arched palate.

Removal
Surgical removal of the adenoid is a procedure called adenoidectomy. Adenoid infection may cause symptoms such as excessive mucus production, which can be treated by its removal. Studies have shown that adenoid regrowth occurs in as many as 19% of the cases after removal. Carried out through the mouth under a general anaesthetic (or less commonly a topical), adenoidectomy involves the adenoid being curetted, cauterized, lasered, or otherwise ablated. The adenoid is often removed along with the palatine tonsils.

title: Adenoid


text:
Adenoidectomy

Adenoidectomy is the surgical removal of the adenoid for reasons which include impaired breathing through the nose, chronic infections, or recurrent earaches. The effectiveness of removing the adenoids in children to improve recurrent nasal symptoms and/or nasal obstruction has not been well studied. The surgery is less commonly performed in adults in whom the adenoid is much smaller and less active than it is in children. It is most often done on an outpatient basis under general anesthesia. Post-operative pain is generally minimal and reduced by icy or cold foods. The procedure is often combined with tonsillectomy (this combination is usually called an "adenotonsillectomy" or "T&A"), for which the recovery time is an estimated 10–14 days, sometimes longer, mostly dependent on age.

Adenoidectomy is not often performed under one year of age as adenoid function is part of the body's immune system but its contribution to this decreases progressively beyond this age.

Medical uses
The indications for adenoidectomy are still controversial. Widest agreement surrounds the removal of the adenoid for obstructive sleep apnea, usually combined with tonsillectomy. Even then, it has been observed that a significant percentage of the study population (18%) did not respond. There is also support for adenoidectomy in recurrent otitis media in children previously treated with tympanostomy tubes. Finally, the effectiveness of adenoidectomy in children with recurrent upper respiratory tract infections, common cold, otitis media and moderate nasal obstruction has been questioned with the outcome, in some studies, being no better than watchful waiting.

Frequency
In 1971, more than one million Americans underwent tonsillectomies and/or adenoidectomies, of which 50,000 consisted of adenoidectomy alone.

By 1996, roughly a half million children underwent some surgery on their adenoid and/or tonsils in both outpatient and inpatient settings. This included approximately 60,000 tonsillectomies, 250,000 combined tonsillectomies and adenoidectomies, and 125,000 adenoidectomies. By 2006, the total number had risen to over 700,000 but when adjusted for population changes, the tonsillectomy "rate" had dropped from 0.62 per thousand children to 0.53 per thousand. A larger decline for combined tonsillectomy and adenoidectomy was noted - from 2.20 per thousand to 1.46. There was no significant change in adenoidectomy rates for chronic infectious reasons (0.25 versus 0.21 per 1000).

History
Adenoidectomy was first performed using a ring forceps through the nasal cavity by William Meyer in 1867.

In the early 1900s, adenoidectomies began to be routinely combined with tonsillectomy. Initially, the procedures were performed by otolaryngologists, general surgeons, and general practitioners but over the past 30 years have been performed almost exclusively by otolaryngologists.

Then, adenoidectomies were performed as treatment of anorexia nervosa, mental retardation, and enuresis or to promote 'good health'. By current standards, these indications seem odd but may be explained by the hypothesis that children might have failed to thrive if they had chronically sore throats or severe obstructive sleep apnea (OSA). Also, children who heard poorly because of chronic otitis media might have had unrecognized speech delay mistaken for intellectual disability. Adenoidectomy might have helped to resolve ear fluid problems, speech delays, and consequent perceptions of low intelligence.

The relationship between enuresis and obstructive apnea, and the benefit of adenoidectomy by implication, is complex and controversial. On one hand, the frequency of enuresis declines as children grow older. On the other, the size of the adenoid, and again by implication, any obstruction that they might be causing, also declines with increasing age. These two factors make it difficult to distinguish the benefits of adenoidectomy from age-related spontaneous improvement. Further, most of the studies in the medical literature which appear to show benefit from adenoidectomy have been case reports or case series. Such studies are prone to unintentional bias. Finally, a recent study of six thousand children has not shown an association between enuresis and obstructive sleep in general but an increase with advancing severity of obstructive sleep apnea, observed only in girls.

A decline in the frequency of the procedure started in the 1930s as its use became controversial. Tonsillitis and adenoiditis requiring surgery became less frequent with the development of antimicrobial agents and a decline in upper respiratory infections among older school-aged children. Also, several studies had shown that adenoidectomy and tonsillectomy were ineffective for many of the indications used at that time as well as the suggestion of an increased risk of developing poliomyelitis after the procedure, later disproved. Prospective clinical trials, performed over the last 2 decades, have redefined the appropriate indications for tonsillectomy and adenoidectomy (T&A), tonsillectomy alone, and adenoidectomy alone.

title: Adenoidectomy


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Cellulose acetate

In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and as a frame material for eyeglasses; it is also used as a synthetic fiber in the manufacture of cigarette filters and playing cards. In photographic film, cellulose acetate film replaced nitrate film in the 1950s, being far less flammable and cheaper to produce.

History
In 1865, French chemist Paul Schützenberger discovered that cellulose reacts with acetic anhydride to form cellulose acetate. The German chemists Arthur Eichengrün and Theodore Becker invented the first soluble forms of cellulose acetate in 1903.

In 1904, Camille Dreyfus and his younger brother Henri performed chemical research and development on cellulose acetate in a shed in their father's garden in Basel, Switzerland, which was then a center of the dye industry. For five years, the Dreyfus brothers studied and experimented in a systematic manner in Switzerland and France. By 1910, they were producing film for the motion picture industry, and a small but constantly growing amount of acetate lacquer, called "dope", was sold to the expanding aircraft industry to coat the fabric covering wings and fuselage.

In 1913, after some twenty thousand separate experiments, they produced excellent laboratory samples of continuous filament yarn, something that had eluded the cellulose acetate industry to this time. Unfortunately, the outbreak of World War I postponed commercial development of this process.

In November 1914, the British Government invited Dr. Camille Dreyfus to come to England to manufacture acetate dope, and the "British Cellulose and Chemical Manufacturing Co" was set up. In 1917, after the United States had entered the war, the U.S. War Department invited Dr. Dreyfus to establish a similar factory in the U.S. Both operations were run successfully throughout the war.

After the war, attention returned to the production of acetate fibers. The first yarn was of fair quality, but sales resistance was heavy, and silk associates worked zealously to discredit acetate and discourage its use. However, the thermoplastic nature of acetate made it an excellent fiber for moiré because the pattern was permanent and did not wash away. The same characteristic also made permanent pleating a commercial fact for the first time, and gave great style impetus to the whole dress industry.

The mixing of silk and acetate in fabrics was accomplished at the beginning, and almost at once cotton was also blended, thus making possible low-cost fabrics by means of a fiber which then was cheaper than silk or acetate. Today, acetate is blended with silk, cotton, wool, nylon, etc. to give fabrics excellent wrinkle recovery, good heft, handle, draping quality, quick drying, proper dimensional stability, cross-dye pattern potential, at a very competitive price.

Fiber
Cellulose acetate fiber, one of the earliest synthetic fibers, is based on cotton or tree pulp cellulose ("biopolymers"). These "cellulosic fibers" have been replaced in many applications by cheaper petro-based fibers (nylon and polyester) in recent decades.

Trade names for acetate include Acele, Avisco, Celanese, Chromspun, and Estron.

Acetate shares many similarities with rayon, and was formerly considered as the same textile. Acetate differs from rayon in the employment of acetic acid in production. The two fabrics are now required to be listed distinctly on garment labels.

Rayon resists heat while acetate is prone to melting. Acetate must be laundered with care either by hand-washing or dry cleaning.

The breathable nature of the fabric suits it for use as a lining. Acetate fabric is used frequently in wedding gowns and other bridal attire. Its lustrous sheen and smooth, satiny texture make it a good alternative to silk.

Properties
Acetate is a low cost, manufactured fiber, which has good draping qualities. Acetate is used in fabrics such as satins, brocades, knit fabrics, and taffetas to accentuate luster, body, drape, and beauty.

 * Hand: soft, smooth, dry, crisp, resilient
 * Comfort: breathes, wicks, dries quickly, no static cling
 * Drape: linings move with the body linings conform to the garment
 * Color: deep brilliant shades with atmospheric dyeing meet colorfastness requirements
 * Luster: light reflection creates a signature appearance
 * Performance: colorfast to perspiration staining, colorfast to dry cleaning, air and vapor permeable
 * Tenacity: weak fiber with breaking tenacity of 1.2 to 1.4 g/d; rapidly loses strength when wet
 * Abrasion: poor resistance
 * Heat retention: poor thermal retention; no allergenic potential (hypoallergenic)
 * Dyeability: (two methods) cross-dying method where yarns of one fiber and those of another fiber are woven into a fabric in a desired pattern; solution-dying method provides excellent color fastness under the effects of sunlight, perspiration, air contaminants and washing

Characteristics

 * cellulosic and thermoplastic
 * selective absorption and removal of low levels of certain organic chemicals
 * easily bonded with plasticizers, heat, and pressure
 * acetate is soluble in many common solvents (especially acetone and other organic solvents) and can be modified to be soluble in alternative solvents, including water
 * hydrophilic: acetate wets easily, with good liquid transport and excellent absorption; in textile applications, it provides comfort and absorbency, but also loses strength when wet
 * acetate fibers are hypoallergenic
 * high surface area
 * made from wood pulp, a renewable resource
 * can be composted or incinerated
 * can be dyed, however special dyes and pigments are required since acetate does not accept dyes ordinarily used for cotton and rayon (this also allows cross-dyeing)
 * resistant to mold and mildew
 * easily weakened by strong alkaline solutions and strong oxidizing agents
 * can usually be washed or dry cleaned; generally does not shrink

Confusion with cellulose triacetate
Cellulose diacetate and cellulose triacetate are mistakenly referred to as the same fiber; although they are similar, their chemical identities differ. Triacetate is known as a generic description or primary acetate containing no hydroxyl group. Acetate fiber is known as modified or secondary acetate having two or more hydroxyl groups. Triacetate fibers, although no longer produced in the United States, contain a higher ratio of acetate-to-cellulose than do acetate fibers.

Film
Cellulose acetate film, made from cellulose diacetate and later cellulose triacetate, was introduced in 1934 as a replacement for the cellulose nitrate film stock that had previously been standard. When exposed to heat or moisture, acids in the film base begin to deteriorate to an unusable state, releasing acetic acid with a characteristic vinegary smell, causing the process to be known as "vinegar syndrome". Acetate film stock is still used in some applications, such as camera negative for motion pictures. Since the 1980s, polyester film stock (sometimes referred to under Kodak's trade name "ESTAR Base") has become more commonplace, particularly for archival applications. Acetate film was also used as the base for magnetic tape, prior to the advent of polyester film.

Magnetic tape
Cellulose acetate magnetic tape was introduced by IBM in 1952 for use on their IBM 726 tape drive in the IBM 701 computer. It was much lighter and easier to handle than the metal tape introduced by UNIVAC in 1951 for use on their UNISERVO tape drive in the UNIVAC I computer. In 1956, cellulose acetate magnetic tape was replaced by the more stable PET film magnetic tape for use on their IBM 727 tape drive.

Other products

 * Apparel: buttons, linings, blouses, dresses, wedding and party attire, home furnishings, draperies, upholstery and slip covers.
 * Eyeglass frames are commonly made with cellulose acetate.
 * Industrial uses: cigarette filters and other filters, ink reservoirs for fiber tip pens.
 * High absorbency products: diapers and medical aid products.
 * The original Lego bricks were manufactured from cellulose acetate from 1949 to 1963.
 * Award Ribbon: Rosettes for equestrian events, dog/cat shows, corporate awards, advertising and identification products all use cellulose acetate ribbon.
 * Playing cards may be made of cellulose acetate.
 * Toys
 * Transparencies for overhead projection

Production
The Federal Trade Commission definition for acetate fiber is: "A manufactured fiber in which the fiber-forming substance is cellulose acetate. Where not less than 92 percent of the hydroxyl groups are acetylated, the term triacetate may be used as a generic description of the fiber."

Acetate is derived from cellulose by initially deconstructing wood pulp into a purified fluffy white cellulose. To manufacture a good product, special qualities of pulps, such as dissolving pulps, are used. The uneven reactivity of cellulose presents a common problem affecting the quality of the cellulose acetate product. The cellulose is reacted with acetic acid and acetic anhydride in the presence of sulfuric acid. It is subjected to a controlled, partial hydrolysis to remove the sulfate and a sufficient number of acetate groups to give the product the desired properties. The anhydroglucose unit is the fundamental repeating structure of cellulose and has three hydroxyl groups which can react to form acetate esters. The most common form of cellulose acetate fiber has an acetate group on approximately two of every three hydroxyls. This cellulose diacetate is known as secondary acetate, or simply as "acetate".

After it is formed, cellulose acetate is dissolved in acetone, forming a viscous solution for extrusion through spinnerets (which resemble a shower head). As the filaments emerge, the solvent is evaporated in warm air via dry spinning, producing fine cellulose acetate fibers.

The first U.S. commercial acetate fiber was produced by the Celanese Corporation in 1924. Current U.S. acetate fiber producers are Celanese, and Eastman Chemical Company.

Method
To this day, no process for the direct production of cellulose acetates has been discovered. As attempts to produce a partial esterification of cellulose result only in a mixture of non-acetylated and fully acetylated cellulose, a two-step synthesis is applied: Cellulose is always completely converted first to cellulose triacetate and then by hydrolysis into cellulose acetates with low degrees of esterification.

Purified cellulose from wood pulp or cotton linters is mixed with glacial acetic acid, acetic anhydride, and a catalyst. The mixture is aged 20 hours during which partial hydrolysis occurs and acid resin precipitates as flakes. These are dissolved in acetone and the solution is purified by filtering. The solution is extruded by spinning in a column of warm air. Solvent is recovered. Filaments are stretched and wound onto beams, cones, or bobbins ready for use. Filaments are finally spun into fiber.

The production is divided into the following process stages:
 * Mechanical conditioning of the pulp: The pulp, which is usually provided as roll or sheet pulp, is fibrillated by means of different types of shredders, such as hammermills and disk refiners, whereby the successive arrangement of both types of shredder ensures optimum dissolving.
 * Chemical pre-treatment: The fibrillated cellulose is treated with acetic acid (if necessary with the addition of small quantities of sulphuric acid) with moderate stirring at 25 °C to 50 °C for about 1 h, resulting in continuous evaporation and condensation of the acetic acid in the spaces between the fibre particles. This causes the cellulose particles to swell, which facilitates the diffusion of the solvent particles into these particles during the following process stage. In addition to this acetic acid vapour pretreatment, there is also a pretreatment in a thin-pulp state. In this process, the cellulose is introduced into large quantities of water or diluted acetic acid and intensively stirred. Subsequent process steps such as pressing or centrifuging constantly increase the concentration of cellulose in the pulp. At the same time, acetic acid is added in ever higher concentrations. The advantage of this process is the saving of shredding, as the cellulose layers can be added directly into the stirred tank.
 * Acetylating the cellulose: In the commercial production of cellulose acetates, the acetic acid process or the methylene chloride process are usually used for acetylation. In acetic acid processes, the pre-treated cellulose mass is reacted in an acetylation mixture of the solvent acetic acid with an excess of acetic anhydride, which serves as an esterification agent, and with sulphuric acid as a catalyst under vigorous mechanical mixing. The reaction is highly exothermic and therefore intensive cooling of the reaction vessels is required. The esterification process is terminated by adding water when a highly viscous clear reaction mixture has formed from the fibrous pulp. This solution must be gel-free and have the desired viscosity. In the methylene chloride process, methylene chloride is used in the acetylation mixture as a solvent instead of acetic acid. Since the low-boiling methylene chloride can be easily removed by distillation, process control is achieved even with highly viscous solutions. Even at low temperatures it can dissolve cellulose triacetate very well. A small amount of sulfuric acid can be used as a catalyst, but often also perchloric acid. However, acetic acid is usually also formed as a by-product of the reaction, so that the solvent is ultimately a mixture of methylene chloride, acetic anhydride and acetic acid. A very rare heterogeneous process is the fiber acetate process, which is only used for the production of cellulose triacetate as an end product. In this process, the cellulose is suspended in a non-solvent (such as benzene) and esterified with acetic anhydride in the presence of perchloric acid as catalyst.
 * Partial hydrolysis: The desired secondary cellulose acetate types are obtained from cellulose triacetate by hydrolysis. For this purpose, the triacetate solution is heated to usually 60 to 80 °C in the presence of an acid catalyst (usually sulfuric acid) by adding water upon stirring and heating. The hydrolysis is controlled by the concentration of the sulfuric acid, the amount of water and the temperature in such a way that the desired molecular degradation (chain scission) is achieved. The hydrolysis process is then stopped by adding basic salts (e.g. sodium or magnesium acetate) which neutralize the acid catalyst.
 * Precipitation of the cellulose acetate: When precipitating cellulose acetate from the reaction solution using dilute acetic acid, it is important to obtain uniform and easily washable cellulose acetate flakes. Before precipitation, any methylene chloride present must be completely distilled off. The acetic acid is then recovered.
 * Washing and drying: By intensive washing, which is usually done in countercurrent, the acetic acid must be removed from the flakes down to the smallest traces, otherwise damage ("charring") will occur during the drying process. After the washing liquid has been pressed off, the flakes are dried on a conveyor belt dryer through which hot air flows to a residual moisture content of approx. 2-5%. For the subsequent production of very high-quality, thermally stable, brightly colored and color-stable thermoplastic molding compounds, the cellulose acetate flakes are also bleached and stabilized in additional process steps (to minimize thermal degradation and discoloration) before final drying.
 * Mixing of the flakes: The final steps are similar to the processing of other plastics: Before the cellulose acetate flakes are transported to a collection container from where they are transported to the appropriate processing plants, the flakes are mixed in a precisely controlled manner. This is to compensate for deviations of the cellulose acetates from different production batches. For many further processing steps the flakes are usually ground into fine powders beforehand. In order to be able to use the cellulose acetate in plastics processing methods such as injection moulding, the powder must also be mixed with suitable plasticisers and other additives, such as functional additives for thermal, weathering, UV and IR stabilisation. The mixtures can be adapted to the corresponding subsequent processing requirements. From the compound produced by melting, granules are produced which can be delivered to the plastics processors.

Disposal and degradation
The global production of CA materials was over 800000 t per year in 2008. While it was initially believed that CA was virtually non-biodegradable, it has been shown that after initial partial deacetylation, the polymer's cellulose backbone is readily biodegraded by cellulase enzymes. In biologically highly active soil, CA fibers are completely destroyed after 4–9 months. Photodegradation is optimal with 280 nm or shorter wavelength UV-irradiation and enhanced by TiO2 pigment. CA cigarette filters take years to be broken down in the open.

Trade names
Cellulose acetate is marketed under various trade names, such as Tenite by the Eastman Chemical Company, zyl and zylonite, Cellon, manufactured by Deutsche Celluloid Fabrik, Eilenburg, Germany, and Rhodoid, manufactured by ''Soc. des Usines Chim. Rhone-Poulenc, Paris, France, and May & Baker Ltd.'', London, UK. Cast film of cellulose acetate is manufactured in Spondon (Derbyshire, UK) by Celanese, and sold as Clarifoil.

Other cellulose esters
Cellulose acetate butyrate (CAB, Tenite II) and cellulose acetate propionate are related derivatives of cellulose, which are both used in inks and coatings. The chief difference between these and cellulose acetate is their solubility in a wider range of solvents.

title: Cellulose acetate


text:
Samuel Liddell MacGregor Mathers

Samuel Liddell (or Liddel) MacGregor Mathers (8 or 11 January 1854 – 5 or 20 November 1918), born Samuel Liddell Mathers, was a British occultist and member of the S.R.I.A.. He is primarily known as one of the founders of the Hermetic Order of the Golden Dawn, a ceremonial magic order of which offshoots still exist. He became so synonymous with the order that Golden Dawn scholar Israel Regardie observed in retrospect that "the Golden Dawn was MacGregor Mathers."

Early life
Mathers was born on 8 or 11 January 1854 in Hackney, London, England. His father, William M. Mathers, died while he was still a boy. His mother, whose maiden name was Collins, died in 1885. He attended Bedford School and subsequently worked in Bournemouth as a clerk, before moving to London following the death of his mother.

His wife was Moina Mathers (née Mina Bergson), sister of the philosopher Henri Bergson.

Lifestyle
Mathers added the "MacGregor" surname as a claim to Highland Scottish heritage. He was a practising vegetarian, or (according to some accounts) vegan, an outspoken anti-vivisectionist, and a non-smoker. It is known that his main interests were magic and the theory of war, his first book being a translation of a French military manual, Practical Instruction in Infantry Campaigning Exercise (1884).

Mathers became increasingly eccentric in his later years as was noted by W. B. Yeats.

Freemasonry
Mathers was introduced to Freemasonry by a neighbour, alchemist Frederick Holland, and was initiated into Hengist Lodge No.195 on 4 October 1877. He was raised as a Master Mason on 30 January 1878. In 1882 he was admitted to the Metropolitan College of the Societas Rosicruciana in Anglia as well as a number of fringe Masonic degrees. Working hard both for and in the SRIA he was awarded an honorary 8th Degree in 1886, and in the same year he lectured on the Kabbalah to the Theosophical Society. He became Celebrant of Metropolitan College in 1891 and was appointed as Junior Substitute Magus of the SRIA in 1892, in which capacity he served until 1900. He left the order in 1903, having failed to repay money which he had borrowed.

In 1891, Mathers assumed leadership of the Hermetic Order of the Golden Dawn upon the death of William Robert Woodman. He moved with his wife to Paris on 21 May 1892. After his expulsion from the Golden Dawn in April 1900, Mathers formed a group in Paris in 1903 called Alpha et Omega (its headquarters, the Ahathoor Temple). Mathers chose the title "Archon Basileus".

Translations
Mathers was a polyglot; among the languages he had studied were English, French, Latin, Greek, Hebrew, Gaelic and Coptic, though he had a greater command of some languages than of others. His translations of such books as The Book of Abramelin (14th century), Christian Knorr von Rosenroth's The Kabbalah Unveiled (1684), Key of Solomon (anonymous, 14th century), The Lesser Key of Solomon (anonymous, 17th century), and the Grimoire of Armadel (17th century), while probably justly criticised with respect to quality, were responsible for making what had been obscure and inaccessible material widely available to the non-academic English-speaking world. They have had considerable influence on the development of occult and esoteric thought since their publication, as has his consolidation of the Enochian magical system of John Dee and Edward Kelley.

Criticism
In addition to many supporters, he had many enemies and critics. One of his most notable enemies was one-time friend and pupil Aleister Crowley, who portrayed Mathers as a villain named SRMD in his 1917 novel Moonchild. According to Crowley's memoirs, The Confessions of Aleister Crowley, Mathers was in the habit of ostensibly playing chess matches against various pagan gods. Mathers would set up the chessboard and seat himself behind the white(s) pieces, with an empty chair opposite him. After making a move for himself, Mathers would then shade his eyes and peer towards the empty chair, waiting for his opponent to signal a move. Mathers would then move a black piece accordingly, then make his next move as white, and so forth. Crowley did not record who won.

Earlier, Crowley wrote in his Confessions that: "As far as I was concerned, Mathers was my only link with the Secret Chiefs to whom I was pledged. I wrote to him offering to place myself and my fortune unreservedly at his disposal; if that meant giving up the Abra-Melin Operation for the present, all right."

In The Doctrine and Literature of the Kabalah (1902), A. E. Waite criticises Mathers' previously published work on the subject, in the following terms: "the Kabbalah Unveiled [1887] of Mr. S. L. MacGregor Mathers, which is largely translation and commentary, and, in addition to other limitations, embraces therefore only a small portion of an extensive literature."

Decline and death
Mathers died on 5 or 20 November 1918 in Paris. The manner of his death is unknown; his death certificate lists no cause of death. Aleister Crowley wrote in his Confessions of the decline of the Hermetic Order of the Golden Dawn, as well as that of MacGregor Mathers. He lamented what he saw as the irredeemable changes by Waite in his order and MacGregor Mathers's legacy of well-meaning but low-quality leadership in his last years.

title: Samuel Liddell MacGregor Mathers


text:
On Kawara

On Kawara was a Japanese conceptual artist who lived in SoHo, New York City, from 1965. He took part in many solo and group exhibitions, including the Venice Biennale in 1976.

Early life
Kawara was born in Kariya, Japan on December 24, 1932. After graduating from Kariya High School in 1951, Kawara moved to Tokyo. Kawara went to Mexico in 1959, where his father was the director of an engineering company. He stayed three years, painting, attending art school and exploring the country. From 1962 to 1964 he moved back and forth between New York and Paris. He travelled through Europe before settling in 1965 in New York City, where he was an intermittent resident until his death.

Work
Kawara belonged to a broadly international generation of Conceptual artists that began to emerge in the mid-1960s, stripping art of personal emotion, reducing it to nearly pure information or idea and greatly playing down the art object. Along with Lawrence Weiner, Joseph Kosuth, Hanne Darboven and others, Kawara gave special prominence to language.

Paris-New York Drawings
From 1962 to 1964 Kawara made about 200 Paris-New York Drawings. Their motifs include stripes and grids like those of the Minimalist painter Agnes Martin. Other drawings depict installation pieces that fill rooms with networks of string.

Today series
From January 4, 1966, Kawara made a long series of "Date paintings" (the Today series), which consist entirely of the date on which the painting was executed in simple white lettering set against a solid background. The date is always documented in the language and grammatical conventions of the country in which the painting is executed (i.e., “26. ÁG. 1995,” from Reykjavík, Iceland, or “13 JUIN 2006,” from Monte Carlo); Esperanto is used when the first language of a given country does not use the Roman alphabet (“6 AŬG. 1993”, from Tokyo). The series is an example of word art.

The paintings, executed in Liquitex on canvas, conform to one of eight standard sizes, ranging from 8x10 inches up to four by six feet, all horizontal in orientation. The exceptions are the three paintings, roughly five by seven feet, executed on July 16, 20 and 21, 1969 — three days when the world was riveted by the Apollo 11 Moon landing.

The dates on the paintings, hand-painted with calculated precision, are always centered on the canvas and painted white, whereas the background colors vary; the paintings from the early years tend to have bold colors, and the more recent ones tend to be darker in tone. For example, Kawara briefly used red for several months in 1967 and then returned to darker hues until 1977. Four coats of paint are carefully applied for the ground and each allowed enough time to dry before being rubbed down in preparation for subsequent coats. Eschewing stencils in favor of hand-drawn characters, Kawara skillfully renders the script, initially a sans-serif, elongated version of Gill Sans, later a quintessentially modernist Futura. Each work is carefully executed by hand. Some days he made more than one. When Kawara was unable to complete the painting on the day it was started he immediately destroyed it. When a Date Painting is not exhibited, it is placed in a cardboard box custom-made for the painting, which is lined with a clipping from a local newspaper from the city in which the artist made the painting; most clippings are from The New York Times. Although the boxes are part of the work, they are rarely exhibited. Each year between 63 and 241 paintings were made.

Each Date Painting is registered in a journal and marked on a One Hundred Years Calendar. When Kawara finished a painting, he applied a swatch of the paint mixture he used to a small rectangle that was then glued onto a chart in the journal. Under each colour is a number showing the painting's sequence in that year and a letter indicating its size. The 48 journals therefore record the details of the painting's size, color and newspaper headline, while the calendar uses colored dots to indicate the days in which a painting was made, and to record the number of days since the artist's birth. Kawara created nearly 3,000 date paintings in more than 112 cities worldwide in a project that was planned to end only with his death.

Title and postcards
Much like the Today series, Kawara uses the number of days followed by the date the work was executed as his life-dates. So the piece entitled Title at the National Gallery of Art has Kawara's life-dates as 26,697 (January 27, 2006) which, when calculated, place Kawara's birthdate at December 24, 1932. Other series of works include the I Went and I Met series of postcards sent to his friends detailing aspects of his life, and a series of telegrams sent to friends and neighbors bearing the message "I AM STILL ALIVE". Between 1968 and 1979, On Kawara created his information series, I Got Up, in which he sent two picture postcards from his location on that morning. All of the 1,500 cards list the artist's time of getting up, the date, the place of residence and the name and address of the receiver; another series of postcards, I Got Up At, was rubber-stamped with the time he got up that morning. The length of each correspondence ranged from a single card to hundreds sent consecutively over a period of months; the gesture's repetitive nature is counterbalanced by the artist's peripatetic global wanderings and exceedingly irregular hours (in 1973 alone he sent postcards from twenty-eight cities).

One Million Years
One Million Years is one of the artist's best-known works about the passage and marking of time. It lists each year for the one million-year period leading up to the artwork's conception and the million years that follow it. The work listing the past million years is dedicated to "all of those who have lived and died", and the work for the future million years is dedicated to "the last one". It is sometimes performed, during which pairs of performers (typically one male and one female for each segment) read dates from each list in order, simultaneously performing One Million Years [Past] and One Million Years [Future].

The artwork was first made in 1969, the year of the Woodstock music festival, major civil protests against the Vietnam War and man's first landing on the Moon. The first audio presentation of the reading of One Million Years occurred in 1993 during Kawara's yearlong solo exhibition “One Thousand Days One Million Years” at Dia Center for the Arts in New York. Visitors could hear One Million Years [Future] being read, while viewing One Million Years [Past] and a group of date paintings. In 2002 Oliver Augst and Christoph Korn directed the radio production of the Hessischer Rundfunk of One Million Years (consisting of 32 CDs). The longest public reading from One Million Years took place at documenta 11 in 2002, where male and female participants sat side by side in a glass enclosure taking turns reading dates for the duration of the 100-day exhibition, switching between [Past] and [Future]. In 2004, the project traveled to Trafalgar Square in London for a continuous outdoor reading lasting 7 days and 7 nights. Since then, readings and recordings have taken place in cities around the world.

One-hundred-year calendars
For his one-hundred-year calendars, Kawara, starting with the date of his birth, systematically marks each day of his life with a yellow dot on the calendars, and registers a completed date painting with a green dot (red dots signify that more than one painting was completed on that given day).

Pure Consciousness
In Pure Consciousness, a traveling exhibition initiated in 1998, Kawara lent seven Date paintings (January 1 to January 7, 1997) to kindergartens and schools in Madagascar, Australia, Bhutan, Côte d'Ivoire, Colombia, Turkey, Japan, Finland, Iceland, Israel, Canada and the United States. At all schools they hang in classrooms, bearing dates that fall within the lifespans of the children.

Exhibitions
Kawara's first exhibitions include the first Nippon Exhibition, at the Tokyo Metropolitan Art Museum, in 1953, and at the Takemiya and Hibiya galleries the following year. His work was exhibited at New York's Dwan Gallery in 1967, and his one-person exhibition "One Million Years" was shown in Düsseldorf, Paris, and Milan in 1971. Kawara's work was included in documenta 5 (1972), 7 (1982), and 11 (2002), in Kassel, and in the Tokyo Biennale (1970), the Kyoto Biennale (1976), and the Venice Biennale (1976).

His work has been included in many conceptual art surveys from the seminal Information show at the Museum of Modern Art, New York in 1970 to Reconsidering the Object of Art: 1965-1975 at the Museum of Contemporary Art, Los Angeles in 1995. Solo exhibitions of his work have included the Otis Art Institute, Los Angeles, and the Centre Pompidou, Paris, in 1977; Continuity/Discontinuity at the Moderna Museet, Stockholm in 1980; Museum Boymans-van Beuningen, Rotterdam in 1991; the Dia Center for the Arts, New York in 1993; and the Dallas Museum of Art.

Kawara's first comprehensive retrospective, “On Kawara—Silence” at the Solomon R. Guggenheim Museum, was installed in 12 sections according to a plan devised by himself. Two years before his death, the artist offered the exhibition curator Jeffrey Weiss a list of oblique titles—including “48 Years,” “Self-Observation” and “Monologue”—for each of the sections. The exhibition was held February 6 through May 3, 2015, and also featured a live reading of Kawara's “One Million Years.”

Artist books
Kawara created several artist's books:
 * One Million Years, 1999, Editions Micheline Szwajcer & Michèle Didier (2 Volumes)
 * I MET, 2004, Editions Micheline Szwajcer & Michèle Didier (12 Volumes)
 * I WENT, 2007, mfc-michèle didier (12 Volumes)
 * I GOT UP, 2008, mfc-michèle didier (12 Volumes)
 * Trilogy, 2008, mfc-michèle didier (3x12 Volumes)
 * I READ, 2017, mfc-michèle didier (6 Volumes)

Art market
In 2007, one of Kawara's "Date Paintings" was sold for $1.8 million at Christie's New York. Another date painting, May 1, 1987, set an auction record for Kawara when it sold for almost $2 million at Christie's New York in 2014.

Death
Kawara died in New York on July 10, 2014, at the age of 81. Kawara's published obituaries state that he was alive for 29,771 days rather than giving dates of birth and death. Kawara's ″100 Years Calendar″ indicates that he was born on December 24, 1932, not on 2 January 1933, as was officially recorded. This would make the date of his death, June 27, 2014.

Influences on contemporary artists
"The Disjunction of Time" is a slideshow installation by Mexican artist Mario Garcia Torres, that delve into the Montecarlo Hotel in Mexico City, here Kawara stayed for late periods in the 1960´s and where the "I Got Up" series started. The audiovisual work is largely informed by Kawara´s ideas.
 * onKawaraUpdate (v2) (2007) by American art collective MTAA updates and automates (via software) the process-oriented nature of On Kawara's date paintings.
 * American artist Eric Doeringer has recreated a number of On Kawara's projects *

including making Today paintings with his own birthday as part of his Bootleg series. From February 6 - May 3, 2015 (concurrent with the exhibition On Kawara - Silence at the Solomon R. Guggenheim Museum) Doeringer recreated Kawara's daily I Got Up, I Met, I Went, and I Read projects and made 30 Today paintings for his Echoes project
 * British artist David Michael Clarke reworked On Kawara's Today series as Today Marriages 1969 - 1999 (2001).
 * In Return to Sender (2004) British artist Jonathan Monk co-opts On Kawara's I Got Up At (1968–1979).
 * I am Still Alive is an installation piece after On Kawara by Martin John Callanan (artist).
 * Start it is a license to practice On Kawara's individual moments by German artist Stefan Hager.
 * 891 (2006) by Belgian artist Kurt Duyck is a Blog Art tribute to On Kawara's I Got Up At.
 * On Kawara is not Dead (2006) by Belgian artist Danny Devos is a Blog Art tribute to On Kawara's I am Still Alive.
 * The Japanese artist Tatsuo Miyajima's use of numbers is a product of On Kawara's influence on him.
 * In his multipart Rwanda Project, executed between 1994 and 2000 in response to the Rwandan genocide, Chilean artist Alfredo Jaar sent Rwandan tourist postcards to his friends around the world, mailed from neighboring Uganda, bearing the names of people whom he'd encountered while travelling in Rwanda, reversing the self-referential content of On Kawara's work 'I am Still Alive'; "Jyamiya Muhawenimawa is still alive!", "Caritas Namazuru is still alive!", "Canisius Nzayisenga is still alive!" etc.
 * Rakawa.net is a micro-blogging web-site, which is devoted to honor On Kawara's work and simultaneously offers users to document and to inform about daily accomplishments, based on the question "What have you achieved today?" and optionally illustrated by a picture.
 * In the series QRs for Kawara, Brazilian artist Marcelo de Melo creates a QR code on 10 July of every year stating that On Kawara has been dead for x number of years. It is a direct reference to Kawara's I Am Still Alive telegrams. The codes are made public through the blog themelopedia.
 * The NFT (non-fungible token) series date pixels by DEJA DEAD pays homage to On Kawara's Today series by applying the concept of a daily creation showcasing that day's date to a 24x24 pixel canvas, and minting it to the Ethereum blockchain.

title: On Kawara