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The site museum is located 300 metres ( 980 ft ) outside of the Toniná archaeological zone . It possesses 2 exhibition rooms and a conference room . The first room explains the pyramidal form of the acropolis and how it relates to Maya mythology , while the main room contains sculptures of the city 's rulers .
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Artefacts in the collection include stone sculptures , ceramics and artefacts sculpted from bone , shell , obsidian and flint . The pieces in the museum graphically depict the two sides of the power exercised by Toniná , on the one hand with sculptures of the city 's rulers and on the other with its depictions of bound prisoners of war .
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= Central Area Command ( RAAF ) =
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Central Area Command was one of several geographically based commands raised by the Royal Australian Air Force ( RAAF ) during World War II . It was formed in March 1940 , and covered the central portion of New South Wales . Headquartered at Sydney , Central Area Command was primarily responsible for air defence , aerial reconnaissance and protection of the sea lanes within its boundaries . It was disbanded in August 1941 and control of its units taken over by other RAAF formations . Proposals in 1943 – 44 to raise a new Central Area Command did not come to fruition .
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= = History = =
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Prior to World War II , the Royal Australian Air Force was small enough for all its elements to be directly controlled by RAAF Headquarters in Melbourne . After war broke out in September 1939 , the RAAF began to implement a decentralised form of command , commensurate with expected increases in manpower and units . Its initial move in this direction was to create Nos. 1 and 2 Groups to control units in Victoria and New South Wales , respectively . Then , between March 1940 and May 1941 , the RAAF divided Australia and New Guinea into four geographically based command @-@ and @-@ control zones : Central Area , Southern Area , Western Area , and Northern Area . The roles of these area commands were air defence , protection of adjacent sea lanes , and aerial reconnaissance . Each was led by an Air Officer Commanding ( AOC ) responsible for the administration and operations of all air bases and units within his boundary .
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No. 2 Group , which had been established on 20 November 1939 , was re @-@ formed as one of the first two area commands , Central Area , on 7 March 1940 . Headquartered in Sydney , Central Area Command was given control of all Air Force units in New South Wales except those in the southern Riverina and the north of the state . Units in Queensland were also temporarily assigned to its control , pending the formation of Northern Area . Central Area 's inaugural AOC was Air Commodore Adrian " King " Cole , who had also led No. 2 Group . His senior air staff officer was Wing Commander Alan Charlesworth .
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In May 1940 it was reported that the area 's headquarters building would change from " Mont Loana " in Point Piper to the mansion " Kilmory " nearby . Cole handed over command of Central Area to Air Commodore Bill Anderson in December 1940 . By August 1941 , the RAAF 's expanding instructional program necessitated the establishment of overarching training organisations on a semi @-@ functional , semi @-@ geographical basis . Accordingly , No. 2 ( Training ) Group was formed in Sydney , taking responsibility for the training units then under Central Area , which was disbanded . Control of other Central Area units was " divided as convenient " , according to the official history of the war , between Northern and Southern Area Commands .
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= = Aftermath = =
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The RAAF 's area command structure was revised in 1942 , following the outbreak of the Pacific War : Northern Area was split into North @-@ Eastern Area and North @-@ Western Area , and a new command covering New South Wales and southern Queensland , Eastern Area , was created , making a total of five commands . In October 1943 , the Air Board proposed carving a new Central Area Command out of Eastern Area , which by then was considered too large to be controlled by one headquarters and therefore ripe for subdivision . This Central Area Command would have been responsible for training and operational units in southern Queensland . The War Cabinet deferred its decision on the proposal . The concept was raised again in August 1944 , and this time the new Central Area Command was to control maintenance units , as well as training and operations , in southern Queensland . Once again , nothing came of the proposal .
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= Corn crake =
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The corn crake , corncrake or landrail ( Crex crex ) is a bird in the rail family . It breeds in Europe and Asia as far east as western China , and migrates to Africa for the northern hemisphere 's winter . It is a medium @-@ sized crake with buff- or grey @-@ streaked brownish @-@ black upperparts , chestnut markings on the wings , and blue @-@ grey underparts with rust @-@ coloured and white bars on the flanks and undertail . The strong bill is flesh @-@ toned , the iris is pale brown , and the legs and feet are pale grey . Juveniles are similar in plumage to adults , and downy chicks are black , as with all rails . There are no subspecies , although individuals from the east of the breeding range tend to be slightly paler than their western counterparts . The male 's call is a loud krek krek , from which the scientific name is derived . The corn crake is larger than its closest relative , the African crake , which shares its wintering range ; that species is also darker @-@ plumaged , and has a plainer face .
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The corn crake 's breeding habitat is grassland , particularly hayfields , and it uses similar environments on the wintering grounds . This secretive species builds a nest of grass leaves in a hollow in the ground and lays 6 – 14 cream @-@ coloured eggs which are covered with rufous blotches . These hatch in 19 – 20 days , and the black precocial chicks fledge after about five weeks . This crake is in steep decline across much of its former breeding range because modern farming practices often destroy nests before breeding is completed . The corn crake is omnivorous but mainly feeds on invertebrates , the occasional small frog or mammal , and plant material including grass seed and cereal grain . Natural threats include introduced and feral mammals , large birds , various parasites and diseases .
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Although numbers have declined steeply in western Europe , this bird is classed as least concern on the IUCN Red List because of its huge range and large , apparently stable , populations in Russia and Kazakhstan . Numbers in western China are more significant than previously thought , and conservation measures have facilitated an increased population in some countries which had suffered the greatest losses . Despite its elusive nature , the loud call has ensured the corn crake has been noted in literature , and garnered a range of local and dialect names .
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| 3,945 |
= = Taxonomy = =
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The rails are a bird family comprising nearly 150 species . Although origins of the group are lost in antiquity , the largest number of species and least specialised forms are found in the Old World , suggesting this family originated there . The taxonomy of the small crakes is complicated , but the closest relative of the corn crake is the African crake , C. egregia , which has sometimes been given its own genus , Crecopsis , but is now more usually placed in Crex . Both species are short @-@ billed brown birds with a preference for grassland rather than wetland habitats typical of rails . Porzana crakes , particularly the ash @-@ throated crake ( Porzana albicollis ) are near relatives of the Crex genus .
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Corn crakes were first described by Linnaeus in his Systema Naturae in 1758 as Rallus crex , but was subsequently moved to the genus Crex , created by German naturalist and ornithologist Johann Matthäus Bechstein in 1803 , and named Crex pratensis . The earlier use of crex gives it priority over Bechstein 's specific name pratensis , and leads to the current name of Crex crex . The binomial name , Crex crex , from the Ancient Greek " κρεξ " , is onomatopoeic , referring to the crake 's repetitive grating call . The common name was formerly spelt as a single word , " corncrake " , but the official version is now " corn crake " . The English names refer to the species habit of nesting in dry hay or cereal fields , rather than marshes used by most members of this family .
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= = Description = =
|
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The corn crake is a medium @-@ sized rail , 27 – 30 cm ( 11 – 12 in ) long with a wingspan of 42 – 53 cm ( 17 – 21 in ) . Males weigh 165 g ( 5 @.@ 8 oz ) on average and females 145 g ( 5 @.@ 1 oz ) . The adult male has the crown of its head and all of its upperparts brown @-@ black in colour , streaked with buff or grey . The wing coverts are a distinctive chestnut colour with some white bars . The face , neck and breast are blue @-@ grey , apart from a pale brown streak from the base of the bill to behind the eye , the belly is white , and the flanks , and undertail are barred with chestnut and white . The strong bill is flesh @-@ coloured , the iris is pale brown , and the legs and feet are pale grey . Compared to the male , the female has warmer @-@ toned upperparts and a narrower duller eye streak . Outside the breeding season , the upperparts of both sexes become darker and the underparts less grey . The juvenile is like the adult in appearance , but has a yellow tone to its upperparts , and the grey of the underparts is replaced with buff @-@ brown . The chicks have black down , as with all rails . While there are no subspecies , all populations show great individual variation in colouring , and the birds gradually become paler and greyer towards the east of the range . Adults undergo a complete moult after breeding , which is normally finished by late August or early September , before migration to south eastern Africa . There is a pre @-@ breeding partial moult prior to the return from Africa , mainly involving the plumage of the head , body and tail . Young birds have a head and body moult about five weeks after hatching .
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The corn crake is sympatric with the African crake on the wintering grounds , but can be distinguished by its larger size , paler upperparts , tawny upperwing and different underparts pattern . In flight , it has longer , less rounded wings , and shallower wingbeats than its African relative , and shows a white leading edge to the inner wing . In both the breeding and wintering ranges it is unlikely to be confused with any other rails , since sympatric species are smaller , with white markings on the upperparts , different underparts patterns and shorter bills . A flying corn crake can resemble a gamebird , but its chestnut wing pattern and dangling legs are diagnostic .
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= = = Voice = = =
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On the breeding grounds , the male corn crake 's advertising call is a loud , repetitive , grating krek krek normally delivered from a low perch with the bird 's head and neck almost vertical and its bill wide open . The call can be heard from 1 @.@ 5 km ( 0 @.@ 93 mi ) away , and serves to establish the breeding territory , attract females , and challenge intruding males . Slight differences in vocalisations mean that individual males can be distinguished by their calls . Early in the season , the call is given almost continuously at night , and often during the day , too . It may be repeated more than 20 @,@ 000 times a night , with a peak between midnight and 3 am . The call has evolved to make a singing male 's location clear , as this species hides in vegetation . The frequency of calling reduces after a few weeks but may intensify again near the end of the laying period before falling away towards the end of the breeding season . To attract males , mechanical imitations of their call can be produced by rubbing a piece of wood down a notched stick , or by flicking a credit card against a comb or zip @-@ fastener . The male also has a growling call , given with the bill shut and used during aggressive interactions .
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The female corn crake may give a call that is similar to that of the male ; it also has a distinctive barking sound , similar in rhythm to the main call but without the grating quality . The female also has a high @-@ pitched cheep call , and a oo @-@ oo @-@ oo sound to call the chick . The chicks make a quiet peeick @-@ peeick contact call , and a chirp used to beg for food . Because of the difficulty in seeing this species , it is usually censused by counting males calling between 11 pm and 3 am ; the birds do not move much at night , whereas they may wander up to 600 m ( 660 yd ) during the day , which could lead to double @-@ counting if monitored then . Identifying individual males suggests that just counting calling birds underestimates the true count by nearly 30 % , and the discrepancy is likely to be greater , since only 80 % of males may call at all on a given night . The corn crake is silent in Africa .
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= = Distribution and habitat = =
|
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The corn crake breeds from Britain and Ireland east through Europe to central Siberia . Although it has vanished from much of its historic range , this bird was once found in suitable habitats in Eurasia everywhere between latitudes 41 ° N and 62 ° N. There is also a sizable population in western China , but this species nests only rarely in northern Spain and in Turkey . Old claims of breeding in South Africa are incorrect , and result from misidentification of eggs in a museum collection which are actually those of the African rail .
|
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The corn crake winters mainly in Africa , from the Democratic Republic of the Congo and central Tanzania south to eastern South Africa . North of this area , it is mainly seen on migration , but occasionally winters in North Africa and to the west and north of its core area in southeast Africa . Most of the South African population of about 2 @,@ 000 birds occurs in KwaZulu @-@ Natal and the former Transvaal Province , and numbers elsewhere in Africa are uncertain . There are several nineteenth @-@ century records , when populations were much higher than now , of birds being seen in western Europe , mainly Britain and Ireland , between December and February .
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This crake migrates to Africa along two main routes : a western route through Morocco and Algeria , and a more important flyway through Egypt . On passage , it has been recorded in most countries between its breeding and wintering ranges , including much of West Africa . Birds from Coll following the western route paused in West Africa on their way further south , and again on the return flight , when they also rested in Spain or North Africa . Eastern migrants have been recorded in those parts of southern Asia that lie between the east of the breeding range and Africa . Further afield , the corn crake has been recorded as a vagrant to Sri Lanka , Vietnam and Australia , the Seychelles , Bermuda , Canada , the US , Greenland , Iceland , the Faroes , the Azores , Madeira , and the Canary Islands .
|
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The corn crake is mainly a lowland species , but breeds up to 1 @,@ 400 m ( 4 @,@ 600 ft ) altitude in the Alps , 2 @,@ 700 m ( 8 @,@ 900 ft ) in China and 3 @,@ 000 m ( 9 @,@ 800 ft ) in Russia . When breeding in Eurasia , the corn crake 's habitats would originally have included river meadows with tall grass and meadow plants including sedges and irises . It is now mainly found in cool moist grassland used for the production of hay , particularly moist traditional farmland with limited cutting or fertiliser use . It also utilises other treeless grasslands in mountains or taiga , on coasts , or where created by fire . Moister areas like wetland edges may be used , but very wet habitats are avoided , as are open areas and those with vegetation more than 50 cm ( 20 in ) tall , or too dense to walk through . The odd bush or hedge may be used as a calling post . Grassland which is not mown or grazed becomes too matted to be suitable for nesting , but locally crops such as cereals , peas , rape , clover or potatoes may be used . After breeding , adults move to taller vegetation such as common reed , iris , or nettles to moult , returning to the hay and silage meadows for the second brood . In China , flax is also used for nest sites . Although males often sing in intensively managed grass or cereal crops , successful breeding is uncommon , and nests in the field margins or nearby fallow ground are more likely to succeed .
|
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When wintering in Africa , the corn crake occupies dry grassland and savanna habitats , occurring in vegetation 30 – 200 cm ( 0 @.@ 98 – 6 @.@ 56 ft ) tall , including seasonally burnt areas and occasionally sedges or reed beds . It is also found on fallow and abandoned fields , uncut grass on airfields , and the edges of crops . It occurs at up to at least 1 @,@ 750 metres ( 5 @,@ 740 ft ) altitude in South Africa . Each bird stays within a fairly small area . Although it sometimes occurs with the African crake , that species normally prefers moister and shorter grassland habitats than does the corn crake . On migration , the corn crake may also occur in wheatfields and around golf courses .
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| 3,968 |
= = Behaviour = =
|
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The corn crake is a difficult bird to see in its breeding sites , usually being hidden by vegetation , but will sometimes emerge into the open . Occasionally , individuals may become very trusting ; for five consecutive summers , an individual crake on the Scottish island of Tiree entered a kitchen to feed on scraps , and , in 1999 , a wintering Barra bird would come for poultry feed once the chickens had finished . In Africa , it is more secretive than the African crake , and , unlike its relative , it is rarely seen in the open , although it occasionally feeds on tracks or road sides . The corn crake is most active early and late in the day , after heavy rain and during light rain . Its typical flight is weak and fluttering , although less so than that of the African crake . For longer flights , such as migration , it has a steadier , stronger action with legs drawn up . It walks with a high @-@ stepping action , and can run swiftly through grass with its body held horizontal and laterally flattened . It will swim if essential . When flushed by a dog , it will fly less than 50 m ( 160 ft ) , frequently landing behind a bush or thicket , and then crouch on landing . If disturbed in the open , this crake will often run in a crouch for a short distance , with its neck stretched forward , then stand upright to watch the intruder . When captured it may feign death , recovering at once if it sees a way out .
|
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The corn crake is solitary on the wintering grounds , where each bird occupies 4 @.@ 2 – 4 @.@ 9 ha ( 10 – 12 acres ) at one time , although the total area used may be double that , since an individual may move locally due to flooding , plant growth , or grass cutting . Flocks of up to 40 birds may form on migration , sometimes associating with common quails . Migration takes place at night , and flocks resting during the day may aggregate to hundreds of birds at favoured sites . The ability to migrate is innate , not learned from adults . Chicks raised from birds kept in captivity for ten generations were able to migrate to Africa and return with similar success to wild @-@ bred young .
|
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| 3,973 |
= = = Breeding = = =
|
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Until 1995 , it was assumed that the corn crake is monogamous , but it transpires that a male may have a shifting home range , and mate with two or more females , moving on when laying is almost complete . The male 's territory can vary from 3 to 51 ha ( 7 @.@ 4 to 126 @.@ 0 acres ) , but averages 15 @.@ 7 ha ( 39 acres ) . The female has a much smaller range , averaging only 5 @.@ 5 ha ( 14 acres ) . A male will challenge an intruder by calling with his wings drooped and his head pointing forward . Usually the stranger moves off ; if it stays , the two birds square up with heads and necks raised and the wings touching the ground . They then run around giving the growling call and lunging at each other . A real fight may ensue , with the birds leaping at each other and pecking , and sometimes kicking . Females play no part in defending the territory .
|
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The female may be offered food by the male during courtship . He has a brief courtship display in which the neck is extended and the head held down , the tail is fanned , and the wings are spread with the tips touching the ground . He will then attempt to approach the female from behind , and then leap on her back to copulate . The nest is typically in grassland , sometimes in safer sites along a hedge , or near an isolated tree or bush , or in overgrown vegetation . Where grass is not tall enough at the start of the season , the first nest may be constructed in herby or marsh vegetation , with the second brood in hay . The second nest may also be at a higher altitude that the first , to take advantage of the later @-@ developing grasses further up a hill . The nest , well hidden in the grass , is built in a scrape or hollow in the ground . It is made of woven coarse dry grass and other plants , and lined with finer grasses . Although nest construction is usually described as undertaken by the female , a recent aviary study found that in the captive population the male always built the nest .
|
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| 3,978 |
The nest is 12 – 15 cm ( 4 @.@ 7 – 5 @.@ 9 in ) in diameter and 3 – 4 cm ( 1 @.@ 2 – 1 @.@ 6 in ) deep . The clutch is 6 – 14 , usually 8 – 12 eggs ; these are oval , slightly glossy , creamy or tinted with green , blue or grey , and blotched red @-@ brown . They average 37 mm × 26 mm ( 1 @.@ 5 in × 1 @.@ 0 in ) and weigh about 13 – 16 g ( 0 @.@ 46 – 0 @.@ 56 oz ) , of which 7 % is shell . The eggs are laid at daily intervals , but second clutches may sometimes have two eggs added per day . Incubation is by the female only ; her tendency to sit tight when disturbed , or wait until the last moment to flee , leads to many deaths during hay @-@ cutting and harvesting . The eggs hatch together after 19 – 20 days , and the precocial chicks leave the nest within a day or two . They are fed by the female for three or four days , but can find their own food thereafter . The juveniles fledge after 34 – 38 days . The second brood is started about 42 days after the first , and the incubation period is slightly shorter at 16 – 18 days . The grown young may stay with the female until departure for Africa .
|
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Nest success in undisturbed sites is high , at 80 – 90 % , but much lower in fertilised meadows and on arable land . The method and timing of mowing is crucial ; mechanized mowing can kill 38 – 95 % of chicks in a given site , and losses average 50 % of first brood chicks and somewhat less than 40 % of second brood chicks . The influence of weather on chick survival is limited ; although chick growth is faster in dry or warm weather , the effects are relatively small . Unlike many precocial species , chicks are fed by their mother to a greater or lesser extent until they become independent , and this may cushion them from adverse conditions . The number of live chicks hatched is more important than the weather , with lower survival in large broods . The annual adult survival rate is under 30 % , although some individuals may live for 5 – 7 years .
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= = = Feeding = = =
|
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The corn crake is omnivorous , but mainly feeds on invertebrates , including earthworms , slugs and snails , spiders , beetles , dragonflies , grasshoppers and other insects . In the breeding areas , it is a predator of Sitona weevils , which infest legume crops. and in the past consumed large amounts of the former grassland pests , leatherjackets and wireworms . This crake will also eat small frogs and mammals , and plant material including grass seed and cereal grain . Its diet on the wintering grounds is generally similar , but includes locally available items such as termites , cockroaches and dung beetles . Food is taken from the ground , low @-@ growing plants and from inside grass tussocks ; the crake may search leaf litter with its bill , and run in pursuit of active prey . Hunting is normally in cover , but , particularly in the wintering areas , it will occasionally feed on grassy tracks or dirt roads . Indigestible material is regurgitated as 1 cm ( 0 @.@ 39 in ) pellets . Chicks are fed mainly on animal food , and when fully grown they may fly with the parents up to 6 @.@ 4 km ( 4 @.@ 0 mi ) to visit supplementary feeding areas . As with other rails , grit is swallowed to help break up food in the stomach .
|
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= = Predators and parasites = =
|
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| 3,986 |
Predators on the breeding grounds include feral and domestic cats , introduced American mink , feral ferrets , otters and red foxes , and birds including the common buzzard and hooded crow . In Lithuania , the introduced raccoon dog has also been recorded as taking corn crakes . When chicks are exposed by rapid mowing , they may be taken by large birds including the white stork , harriers and other birds of prey , gulls and corvids . At undisturbed sites nests and broods are rarely attacked , as reflected in a high breeding success . There is a record of a corn crake on migration through Gabon being killed by a black sparrowhawk .
|
f43f20aea673189287968c028e556310
| 3,988 |
The widespread fluke Prosthogonimus ovatus , which lives in the oviducts of birds , has been recorded in the corn crake , as have the parasitic worm Plagiorchis elegans , the larvae of parasitic flies , and hard ticks of the genera Haemaphysalis and Ixodes .
|
8212847d6530aac37f42fcca9929abac
| 3,989 |
During the reintroduction of corn crakes to England in the 2003 breeding season , enteritis and ill health in pre @-@ release birds was due to bacteria of a pathogenic Campylobacter species . Subsequently , microbiology tests were done to detect infected individuals and to find the source of the bacteria in their environment .
|
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| 3,990 |
= = Status = =
|
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| 3,992 |
Until 2010 , despite a breeding range estimated at 12 @,@ 400 @,@ 000 km2 ( 4 @,@ 800 @,@ 000 sq mi ) , the corn crake was classified as near threatened on the IUCN Red List because of serious declines in Europe , but improved monitoring in Russia indicates that anticipated losses there have not occurred and numbers have remained stable or possibly increased . It is therefore now classed as least concern , since the major populations in Russia and Kazakhstan are not expected to change much in the short term . There are an estimated 1 @.@ 3 – 2 @.@ 0 million breeding pairs in Europe , three @-@ quarters of which are in European Russia , and a further 515 @,@ 000 – 1 @,@ 240 @,@ 000 pairs in Asiatic Russia ; the total Eurasian population has been estimated at between 5 @.@ 45 and 9 @.@ 72 million individuals . In much of the western half of its range , there have been long @-@ term declines that are expected to continue , although conservation measures have enabled numbers to grow in several countries , including a five @-@ fold increase in Finland , and a doubling in the UK . In the Netherlands , there were 33 breeding territories in 1996 , but this number had increased to at least 500 by 1998 .
|
58217eb52102fafb8091a6428f610b51
| 3,994 |
The breeding corn crake population had begun to decline in the 19th century , but the process gained pace after World War II . The main cause of the steep declines in much of Europe is the loss of nests and chicks from early mowing . Haymaking dates have moved forward in the past century due to faster crop growth , made possible by land drainage and the use of fertilisers , and the move from manual grass @-@ cutting using scythes to mechanical mowers , at first horse @-@ drawn and later pulled by tractors . Mechanisation also means that large areas can be cut quickly , leaving the crake with no alternative sites to raise either a first brood if suitable habitat has gone , or a replacement brood if the first nest is destroyed . The pattern of mowing , typically in a circular pattern from the outside of a field to its centre , gives little chance of escape for the chicks , which are also exposed to potential animal predators . Adults can often escape the mowers , although some incubating females sit tight on the nest , with fatal results .
|
4f4c6c3c8a04f17ec65e3e45e8a3872e
| 3,995 |
Loss of habitat is the other major threat to the corn crake . Apart from the reduced suitability of drained and fertilised silage fields compared to traditional hay meadows , in western Europe the conversion of grassland to arable has been aided by subsidies , and further east the collapse of collective farming has led to the abandonment and lack of management of much land in this important breeding area . More localised threats include floods in spring , and disturbance by roads or wind farms . This bird is good eating ; when they were common in England , Mrs Beeton recommended roasting four on a skewer . More significant than direct hunting is the loss of many birds , up to 14 @,@ 000 a year , in Egypt , where migrating birds are captured in nets set for the quail with which they often migrate . Although this may account for 0 @.@ 5 – 2 @.@ 7 % of the European population , the losses to this form of hunting are less than when the targeted species were more numerous and predictable .
|
9d1b00f1356071c82a68d245192e5492
| 3,996 |
Most European countries have taken steps to conserve the corn crake and produce national management policies ; there is also an overall European action plan . The focus of conservation effort is to monitor populations and ecology and to improve survival , principally through changing the timing and method of hay harvesting . Later cutting gives time for breeding to be completed , and leaving uncut strips at the edges of fields and cutting from the centre outwards reduces the casualties from mowing . Implementing these changes is predicted to stop the population decline if the measures are applied on a sufficiently large scale . Reduction of illegal hunting , and protection in countries where hunting is still allowed , are also conservation aims . Reintroduction of the corn crake is being attempted in England , and breeding sites are scheduled for protection in many other countries . Where breeding sites impinge on urban areas , there are cost implications , estimated in one German study at several million euros per corn crake . The corn crake does not appear to be seriously threatened on its wintering grounds and may benefit from deforestation , which creates more open habitats .
|
92d6e9c81588e5249be12a2ed2348a3d
| 3,997 |
= = In culture = =
|
0c51266b8c694911f19077e267e8527e
| 3,999 |
Most rails are secretive wetland birds that have made little cultural impression , but as a formerly common farmland bird with a loud nocturnal call that sometimes led to disturbed sleep for rural dwellers , the corn crake has acquired a variety of folk names and some commemoration in literature .
|
90e8d4d059b5b95e619eaf61d61d16a7
| 4,001 |
= = = Names = = =
|
e93d9af9727066fc1ae5769f03778526
| 4,003 |
The favoured name for this species among naturalists has changed over the years , with " landrail " and variants of " corncrake " being preferred at various times . " Crake gallinule " also had a period of popularity between 1768 and 1813 . The originally Older Scots " cornecrake " was popularised by Thomas Bewick , who used this term in his 1797 A History of British Birds . Other Scots names include " corn scrack " and " quailzie " ; the latter term , like " king of the quail " , " grass quail " , the French " roi de caille " , and the German " Wachtelkönig " refer to the association with the small gamebird . Another name , " daker " , has been variously interpreted as onomatopoeic , or derived from the Old Norse ager @-@ hoene , meaning " cock of the field " ; variants include " drake " , " drake Hen " and " gorse drake " .
|
ecfb66e7448e3d4700013aab94ee7540
| 4,005 |
= = = In literature = = =
|
5efe575c6087330e79aa027747961c53
| 4,007 |
Corn crakes are the subject of three stanzas of the seventeenth century poet Andrew Marvell 's " Upon Appleton House " , written in 1651 about the North Yorkshire country estate of Thomas Fairfax . The narrator depicts the scene of a mower cutting the grass , before his " whistling Sithe " unknowingly " carves the Rail " . The farmhand draws out the scythe " all bloody from its breast " and " does the stroke detest " . It continues with a stanza that demonstrates the problematic nature of the corn crake 's nesting habits :
|
92ed7f0e100f6a1bbb64453847353185
| 4,009 |
John Clare , the nineteenth @-@ century English poet based in Northamptonshire , wrote " The Landrail " , a semi @-@ comic piece which is primarily about the difficulty of seeing corn crakes – as opposed to hearing them . In the fourth verse he exclaims : " Tis like a fancy everywhere / A sort of living doubt " . Clare wrote about corn crakes in his prose works too , and his writings help to clarify the distribution of this rail when it was far more widespread than now .
|
e57e2255fffd32428185c0b6ecf0a137
| 4,010 |
The Finnish poet Eino Leino also wrote about the bird in his poem " Nocturne " .
|
42b4a4b617e353258f2a9adf55feb8cc
| 4,011 |
The proverbial use of the corn crake 's call to describe someone with a grating or unmelodious voice is illustrated in the quotation " thanks to a wee woman with a voice like a corncrake who believed she was an apprentice angel " . This usage dates from at least the first half of the nineteenth century , and continues through to the present .
|
38138df8e9b6244e59ef1fa6628c22dc
| 4,012 |
= Acute myeloid leukemia =
|
43a32ea012f0156ba9a610166d8414c4
| 4,015 |
Acute myeloid leukemia ( AML ) , also known as acute myelogenous leukemia or acute nonlymphocytic leukemia ( ANLL ) , is a cancer of the myeloid line of blood cells , characterized by the rapid growth of abnormal white blood cells that accumulate in the bone marrow and interfere with the production of normal blood cells . AML is the most common acute leukemia affecting adults , and its incidence increases with age . Although AML is a relatively rare disease , accounting for roughly 1 @.@ 2 % of cancer deaths in the United States , its incidence is expected to increase as the population ages .
|
2bbc32229f72ea097fa5b615590f5841
| 4,017 |
The symptoms of AML are caused by replacement of normal bone marrow with leukemic cells , which causes a drop in red blood cells , platelets , and normal white blood cells . These symptoms include fatigue , shortness of breath , easy bruising and bleeding , and increased risk of infection . Several risk factors and chromosomal abnormalities have been identified , but the specific cause is not clear . As an acute leukemia , AML progresses rapidly and is typically fatal within weeks or months if left untreated .
|
aac57765a91aef32188a445d25cf6a0f
| 4,018 |
AML has several subtypes ; treatment and prognosis vary among subtypes . AML is cured in 35 – 40 % of people less than 60 years old and 5 – 15 % more than 60 years old . Older people who are not able to withstand intensive chemotherapy have an average survival of 5 – 10 months .
|
ca5e125591cd01cfb12eb73d665dc538
| 4,019 |
AML is treated initially with chemotherapy aimed at inducing a remission ; people may go on to receive additional chemotherapy or a hematopoietic stem cell transplant . Recent research into the genetics of AML has resulted in the availability of tests that can predict which drug or drugs may work best for a particular person , as well as how long that person is likely to survive . The treatment and prognosis of AML differ from those of chronic myelogenous leukemia ( CML ) in part because the cellular differentiation is not the same ; AML involves higher percentages of dedifferentiated and undifferentiated cells , including more blasts ( myeloblasts , monoblasts , and megakaryoblasts ) .
|
0edf9c4b876a2901aa1d129a5827eb31
| 4,020 |
= = Signs and symptoms = =
|
e73a6339951e88c9dff94ab8621ff527
| 4,022 |
Most signs and symptoms of AML are caused by the replacement of normal blood cells with leukemic cells . A lack of normal white blood cell production makes people more susceptible to infections ; while the leukemic cells themselves are derived from white blood cell precursors , they have no infection @-@ fighting capacity . A drop in red blood cell count ( anemia ) can cause fatigue , paleness , and shortness of breath . A lack of platelets can lead to easy bruising or bleeding with minor trauma .
|
eedb5e929ded77e2aca42c6f6f2e9952
| 4,024 |
The early signs of AML are often vague and nonspecific , and may be similar to those of influenza or other common illnesses . Some generalized symptoms include fever , fatigue , weight loss or loss of appetite , shortness of breath , anemia , easy bruising or bleeding , petechiae ( flat , pin @-@ head sized spots under the skin caused by bleeding ) , bone and joint pain , and persistent or frequent infections .
|
b3a35a4331b1191dcc08a98e2ee6e552
| 4,025 |
Enlargement of the spleen may occur in AML , but it is typically mild and asymptomatic . Lymph node swelling is rare in AML , in contrast to acute lymphoblastic leukemia . The skin is involved about 10 % of the time in the form of leukemia cutis . Rarely , Sweet 's syndrome , a paraneoplastic inflammation of the skin , can occur with AML .
|
e8dc05f5b890614098b5d1f0ac93db0a
| 4,026 |
Some people with AML may experience swelling of the gums because of infiltration of leukemic cells into the gum tissue . Rarely , the first sign of leukemia may be the development of a solid leukemic mass or tumor outside of the bone marrow , called a chloroma . Occasionally , a person may show no symptoms , and the leukemia may be discovered incidentally during a routine blood test .
|
b402f53b731042a42f2baa4bbf7c3c50
| 4,027 |
= = Risk factors = =
|
86a4b1d56970b151e37e187a6d8d57b6
| 4,029 |
A number of risk factors for developing AML have been identified , including : other blood disorders , chemical exposures , ionizing radiation , and genetics .
|
429d1ff06bc7673452a67b1ef50a2200
| 4,031 |
= = = Preleukemia = = =
|
f5b05573688a4e5cf6919295fcb28070
| 4,033 |
" Preleukemic " blood disorders , such as myelodysplastic syndrome ( MDS ) or myeloproliferative disease ( MPS ) , can evolve into AML ; the exact risk depends on the type of MDS / MPS .
|
73ce0275b4484c21b5565c1574f1b547
| 4,035 |
= = = Chemical exposure = = =
|
a6caf3d921ec0a736bedc6cec331e8e8
| 4,037 |
Exposure to anticancer chemotherapy , in particular alkylating agents , can increase the risk of subsequently developing AML . The risk is highest about three to five years after chemotherapy . Other chemotherapy agents , specifically epipodophyllotoxins and anthracyclines , have also been associated with treatment @-@ related leukemias , which are often associated with specific chromosomal abnormalities in the leukemic cells .
|
ebf4bea38fcbead43a1098ec6d2e2655
| 4,039 |
Occupational chemical exposure to benzene and other aromatic organic solvents is controversial as a cause of AML . Benzene and many of its derivatives are known to be carcinogenic in vitro . While some studies have suggested a link between occupational exposure to benzene and increased risk of AML , others have suggested the attributable risk , if any , is slight .
|
5b5c39fc8f4375ee9564bf9cb6c4a92e
| 4,040 |
= = = Radiation = = =
|
de1bfa30e0748a3dc2af46daebbff853
| 4,042 |
High amounts of ionizing radiation exposure can increase the risk of AML . Survivors of the atomic bombings of Hiroshima and Nagasaki had an increased rate of AML , as did radiologists exposed to high levels of X @-@ rays prior to the adoption of modern radiation safety practices . People treated with ionizing radiation after treatment for prostate cancer , non @-@ Hodgkin lymphoma , lung cancer and breast cancer have the highest chance of acquiring AML , but this increased risk returns to the background risk observed in the general population after 12 years .
|
efd626055c1fbc7666df8e50683e00c0
| 4,044 |
= = = Genetics = = =
|
ef4a610b71aecdd3b3f82f58e01ccc2c
| 4,046 |
A hereditary risk for AML appears to exist . Multiple cases of AML developing in a family at a rate higher than predicted by chance alone have been reported . Several congenital conditions may increase the risk of leukemia ; the most common is probably Down syndrome , which is associated with a 10- to 18 @-@ fold increase in the risk of AML .
|
a416244142d10257f28807157e90acbc
| 4,048 |
= = Diagnosis = =
|
e973706bd7f6717cf1720522d110c11e
| 4,050 |
The first clue to a diagnosis of AML is typically an abnormal result on a complete blood count . While an excess of abnormal white blood cells ( leukocytosis ) is a common finding , and leukemic blasts are sometimes seen , AML can also present with isolated decreases in platelets , red blood cells , or even with a low white blood cell count ( leukopenia ) . While a presumptive diagnosis of AML can be made by examination of the peripheral blood smear when there are circulating leukemic blasts , a definitive diagnosis usually requires an adequate bone marrow aspiration and biopsy .
|
76f2a882704d38b831c23f8bb3652b73
| 4,052 |
Marrow or blood is examined under light microscopy , as well as flow cytometry , to diagnose the presence of leukemia , to differentiate AML from other types of leukemia ( e.g. acute lymphoblastic leukemia - ALL ) , and to classify the subtype of disease . A sample of marrow or blood is typically also tested for chromosomal abnormalities by routine cytogenetics or fluorescent in situ hybridization . Genetic studies may also be performed to look for specific mutations in genes such as FLT3 , nucleophosmin , and KIT , which may influence the outcome of the disease .
|
d9cf0a37f7acb0ec289e044f94bb7167
| 4,053 |
Cytochemical stains on blood and bone marrow smears are helpful in the distinction of AML from ALL , and in subclassification of AML . The combination of a myeloperoxidase or Sudan black stain and a nonspecific esterase stain will provide the desired information in most cases . The myeloperoxidase or Sudan black reactions are most useful in establishing the identity of AML and distinguishing it from ALL . The nonspecific esterase stain is used to identify a monocytic component in AMLs and to distinguish a poorly differentiated monoblastic leukemia from ALL .
|
699e0b24bd216add2b9c9e994bd71299
| 4,054 |
The diagnosis and classification of AML can be challenging , and should be performed by a qualified hematopathologist or hematologist . In straightforward cases , the presence of certain morphologic features ( such as Auer rods ) or specific flow cytometry results can distinguish AML from other leukemias ; however , in the absence of such features , diagnosis may be more difficult .
|
65103ae2a372b52a8acb21d89222fc6b
| 4,055 |
The two most commonly used classification schemata for AML are the older French @-@ American @-@ British ( FAB ) system and the newer World Health Organization ( WHO ) system . According to the widely used WHO criteria , the diagnosis of AML is established by demonstrating involvement of more than 20 % of the blood and / or bone marrow by leukemic myeloblasts , except in the three best prognosis forms of AML with recurrent genetic abnormalities ( t ( 8 ; 21 ) , inv ( 16 ) , and t ( 15 ; 17 ) ) in which the presence of the genetic abnormality is diagnostic irrespective of blast percent . The French – American – British ( FAB ) classification is a bit more stringent , requiring a blast percentage of at least 30 % in bone marrow ( BM ) or peripheral blood ( PB ) for the diagnosis of AML . AML must be carefully differentiated from " preleukemic " conditions such as myelodysplastic or myeloproliferative syndromes , which are treated differently .
|
57c5f9375225f2163712fe062c063609
| 4,056 |
Because acute promyelocytic leukemia ( APL ) has the highest curability and requires a unique form of treatment , it is important to quickly establish or exclude the diagnosis of this subtype of leukemia . Fluorescent in situ hybridization performed on blood or bone marrow is often used for this purpose , as it readily identifies the chromosomal translocation [ t ( 15 ; 17 ) ( q22 ; q12 ) ; ] that characterizes APL . There is also a need to molecularly detect the presence of PML / RARA fusion protein , which is an oncogenic product of that translocation .
|
99f31f9db85fc5bc2e2b1d1669ff0602
| 4,057 |
= = = World Health Organization = = =
|
6e4d88d3314b70acd3914fae4d71fcd1
| 4,059 |
The WHO 2008 classification of acute myeloid leukemia attempts to be more clinically useful and to produce more meaningful prognostic information than the FAB criteria . Each of the WHO categories contains numerous descriptive subcategories of interest to the hematopathologist and oncologist ; however , most of the clinically significant information in the WHO schema is communicated via categorization into one of the subtypes listed below .
|
61a93be63d06b2eeb64aaee2310d490a
| 4,061 |
The WHO subtypes of AML are :
|
f2ad35219399f2395e8512f6c76c1a68
| 4,062 |
Acute leukemias of ambiguous lineage ( also known as mixed phenotype or biphenotypic acute leukemia ) occur when the leukemic cells can not be classified as either myeloid or lymphoid cells , or where both types of cells are present .
|
d713e16a41547ee7f935adaf2b4f75b9
| 4,063 |
= = = French @-@ American @-@ British = = =
|
c911825c663b28db32708d93d398bf9d
| 4,065 |
The French @-@ American @-@ British ( FAB ) classification system divides AML into eight subtypes , M0 through to M7 , based on the type of cell from which the leukemia developed and its degree of maturity . This is done by examining the appearance of the malignant cells with light microscopy and / or by using cytogenetics to characterize any underlying chromosomal abnormalities . The subtypes have varying prognoses and responses to therapy . Although the WHO classification ( see above ) may be more useful , the FAB system is still widely used .
|
12b901e88cf3f32d9b316469ff83dff7
| 4,067 |
Eight FAB subtypes were proposed in 1976 .
|
819892d2bcfd413825a4149a168f6331
| 4,068 |
The morphologic subtypes of AML also include rare types not included in the FAB system , such as acute basophilic leukemia , which was proposed as a ninth subtype , M8 , in 1999 .
|
564b0ed25261fd9e8a755c841dc1245d
| 4,069 |
= = Pathophysiology = =
|
da3ed0b3481769797eae0c511e6eca0e
| 4,071 |
The malignant cell in AML is the myeloblast . In normal hematopoiesis , the myeloblast is an immature precursor of myeloid white blood cells ; a normal myeloblast will gradually mature into a mature white blood cell . In AML , though , a single myeloblast accumulates genetic changes which " freeze " the cell in its immature state and prevent differentiation . Such a mutation alone does not cause leukemia ; however , when such a " differentiation arrest " is combined with other mutations which disrupt genes controlling proliferation , the result is the uncontrolled growth of an immature clone of cells , leading to the clinical entity of AML .
|
bf98ff8b9c49fd165eaafbcd34e331ea
| 4,073 |
Much of the diversity and heterogeneity of AML stems is because leukemic transformation can occur at a number of different steps along the differentiation pathway . Modern classification schemes for AML recognize the characteristics and behavior of the leukemic cell ( and the leukemia ) may depend on the stage at which differentiation was halted .
|
35881ee0f63426b3e89925b901d0ec30
| 4,074 |
Specific cytogenetic abnormalities can be found in many people with AML ; the types of chromosomal abnormalities often have prognostic significance . The chromosomal translocations encode abnormal fusion proteins , usually transcription factors whose altered properties may cause the " differentiation arrest " . For example , in acute promyelocytic leukemia , the t ( 15 ; 17 ) translocation produces a PML @-@ RARα fusion protein which binds to the retinoic acid receptor element in the promoters of several myeloid @-@ specific genes and inhibits myeloid differentiation .
|
f16aacfd4ad28925325757e0559dc54e
| 4,075 |
The clinical signs and symptoms of AML result from the growth of leukemic clone cells , which tends to displace or interfere with the development of normal blood cells in the bone marrow . This leads to neutropenia , anemia , and thrombocytopenia . The symptoms of AML are , in turn , often due to the low numbers of these normal blood elements . In rare cases , people with AML can develop a chloroma , or solid tumor of leukemic cells outside the bone marrow , which can cause various symptoms depending on its location .
|
fe0630370d23425a273043bbead0681c
| 4,076 |
An important pathophysiological mechanism of leukemogenesis in AML is the epigenetic induction of dedifferentiation by genetic mutations that alter the function of epigenetic enzymes , such as the DNA demethylase TET2 and the metabolic enzymes IDH1 and IDH2 , which lead to the generation of a novel oncometabolite , D @-@ 2 @-@ hydroxyglutarate , which inhibits the activity of epigenetic enzymes such as TET2 . The hypothesis is that such epigenetic mutations lead to the silencing of tumor suppressor genes and / or the activation of proto @-@ oncogenes .
|
1875812c2191c8bac3c2cdc3b43734d5
| 4,077 |
= = Treatment = =
|
7c01125467cb228dab58ccbeb189f6ed
| 4,079 |
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