In the past, the rhizomes (Norwegian: moldfôr) of selected species were collected for fodder. Only scattered records of such use are available from southern Norway, and the tradition’s core area is found in the two North Norwegian counties of Nordland and Troms, in accordance with the longer winters encountered in the north, frequently leading to fodder shortage in early spring. The tradition extends northeastwards into Finnmark, but is less well documented there. Although numerous sources mention the use of fern rhizomes for fodder, the fern species hiding behind the tradition are incompletely known. This paper aims at reviewing available data in terms of identifyng the species used for fodder, the history and geographical distribution of such use, and other relevant traditions, e.g. the timing and mode of collection, and the way the rhizomes were used.Although ferns are often known under collective names in Norway, e.g. The study is based on data extracted from a variety of archival and literature sources; the latter retrived from my database of more than 7500 publications providing information on plant names and plant uses in Norway.Dryopteris filix-mas and Matteuccia struthiopteris stand out as the most important species serving as sources of fern rhizomes for fodder. Locally, Dryopteris expansa was the preferred species, and this taxon may to some extent be overlooked in the records so far available. With a few exceptions, Norwegian folk tradition singles out Athyrium filix-femina as a harmful and poisonous species, causing livestock to go blind and lame, but whether this is true or not, remains unknown; the symptoms are in fact documented elsewhere as a consequence of poisoning due to Dryopteris filix-mas. In coastal north Norway, fern rhizomes were regularly collected for fodder, both in late autumn and early spring, and used to remedy a recurrent shortage of fodder in late winter and spring. Locally, the tradition of collecting fern rhizomes lived on until the 1940’s or 1950’s. Although mainly a tradition of the ethnic Norwegians, it had also been adopted by the farmers belonging to the Finnish and Sámi ethnic minorities.More than 200 individual records mention the use of fern rhizomes for fodder in Norway. Only a fraction of these, typically made by botanist recording data on plant uses, provides information on the identity of the species used. Based on these, Matteuccia struthiopteris and Dryopteris filix-mas, locally also Dryopteris expansa. Athyrium filix-femina was considered to be poisonous, and usually avoided.Fern rhizomes have a long tradition as an additional fodder for livestock in Norway. Preferred species were  Athyrium filix-femina (L.) Roth, Dryopteris expansa (C. Presl.) Fraser-Jenk. & Jermy, Matteuccia struthiopteris (L.) Tod., and other taxa may predominate in luxuriant forest vegetation and on the lower mountain slopes. Conspicuous and abundantly available, such species have been well known to farmers during past times of subsidence economy, which in coastal Norway was largely based on a combination of agriculture and fisheries.Ferns form an important part of the flora and vegetation of Norway, in particular in the humid coastal areas. Ferns are usually avoided by grazing animals, and the fronds were not generally scythed or otherwise collected for fodder. Nonetheless, fern species formed an important supplementary source of livestock fodder in Norway, in particular in the north. Rhizomes of several species were dug up and boiled, usually together with other foodstuffs of the most diverse kind, ranging from fish remains and kelp to twigs and bark of various deciduous trees, heather and seaweeds.Asplenium spp.), Blechnaceae (Blechnum spicant (L.) Roth), Dennstaedtiaceae (Pteridium aquilinum (L.) Kuhn), Dryopteridaceae  Schott), Polypodiaceae (Polypodium vulgare L.), and Woodsiaceae (Athyrium filix-femina and Matteuccia struthiopteris). The tiny species of Ophioglossaceae  form a separate group, and have been excluded here. Norwegian traditions related to Botrychium spp. are discussed by Rolf Nordhagen ) moldfôr (‘soil fodder’) almost by definition refer to fern rhizomes and their use, whereas a number of other Norwegian (and Finnish orf Sámi) fern terms may refer both to fern rhizomes and the above-ground parts. Thus, data on the latter group need to include additional information to reveal if the record refers to some kind of fodder use of fern rhizomes. The problem of identifying the species is dealt with extensively below; in general, only informants or recorders with some kind of botanical training have ventured to name the species hiding behind the vernacular names. The material has been arranged and analysed accordingly, allowing the multitude of records related to unidentified species to provide a variety of information on the use of fern rhizomes, e.g. on tools needed, time of harvest, moods of use etc., and providing a much better picture of the general distribution of the tradition than the “identified” records alone would allow. As far as possible, all records are referred to counties  related to Botrychium) are often merged into a single ethnotaxonomical unit. In general, when using such terms, people have been surprisingly successful in circumscribing the otherwise rather variable representatives of the various fern families that were previously included in Polypodiaceae s.l.  in Dalsfjord (Volda), Møre og Romsdal  for Dryopteris filix-mas in Os, Hordaland . If ferns  anf ferns (: 222). S anf fernblom, a number of other collective names for ferns exist  in modern Norwegian .Apart from s exist , aordland (: 32), , or the blom as it was also called. The size differs according to the age of the plant, but it may be 15 to 20 cm long, and looks a little like an ananas. Outside, it is dark brown, but if it is chopped into pieces, the interior has a pale green colour. The taste is bitter, but it was much used as an additional fodder on the farms in the [Holmstaddalen] valley”  may be quoted: “I am not aware that there is more than one kind. It has root which become as large as a medium-sized rutabaga. But the roots are in layers outside each other. Their outside is black, but inside they are pale green. It is called valley” (: 100).Locally, people would discriminate between two or more kinds of fern rhizomes, and most would know that only certain fern species could or should be used. Unfortunately, vouchers specimens and detailed records that allow the species to be identified are few and far between. A review of this aspect is a primary goal of this paper, adding details on how and when the collection of rhizomes was done, the way they were used, and the geographical distribution of the practice.gáiski and Finnish kaiski are closely related, and the most frequent terms. As noted for Sámi by Just Qvigstad, the term is a Norse loan-word ( and other similar and harmful [species]” . Nomaullfoor in his extensive travel account  suggests that the rhizomes derived from a Dryopteris species, assumed to be D. filix-mas by Jens Holmboe . Alblomgræs, of which the root is used for livestock”  noIn the southern parts of Norway, the old tradition of collecting fern rhizomes for fodder rarely survived into the 20th century. Further north, rhizomes were still frequently collected during the early decades of the 20th century, and locally, the tradition survived until World War II or beyond . LJens Holmboe was the first to carry out a detailed study of the use of fern rhizomes in North Norway, in particular in the interior valleys of Troms. His brief paper  deals wiMatteuccia struthiopteris . His material, however, was limited, and later additions tend to modify the picture.According to the review of Holmboe : 762), tris Fig.  and Dryo, tris FiMatteuccia struthiopteris were used: “Roots were collected in spring as cattle fodder.” (…) “It was common strutsvinge (Struthiopteris), which is called telgblom there.” .grofte. In spring, when there was little hay, they would chop some grofterot. It was the root of storgrofte (Athyrium filix-femina and Dryopteris filix-mas), which people looked for. The root of einstape [Pteridium aquilinum] was not considered a good root for livestock fodder. I do not know the term moldfór from this area.” .Matteuccia struthiopteris: “(…) whereas the roots of the large fern (Struthiopteris vulgaris), which grows along the brook in sun-warm slopes, and which is otherwise, under the name of “brom” or “moldfor”, given to the catlle to eat, (…)” (” (EBATA 2001:12). The latter identification gains support from the sites that were preferred for collecting rhizomes, namely north-facing slopes, often damp and with abundant Dryopteris expansa, whereas dry, southfacing slopes, in this area with much D. filix-mas and Pteridium aquilinum, were avoided. Not least due to need for identifying the correct and desired source or rhizomes, the locals in this area had separate names for several fern species, including jisk for Athyrium filix-femina and telli for Matteuccia struthiopteris, collectively known as storblom (‘large fern’), whereas småblom  was Gymnocarpium dryopteris (L.) Newman, Phegopteris connectilis (Michx.) Watt, and perhaps also other species (EBATA 2001:12).At Hamarøy, nsa Fig.  was the Matteuccia struthiopteris as the source of fern rhizomes for fodder use: “In addition, the roots of Osmunda struthiopteris [= Matteuccia struthiopteris] are dug up, and given to sheep and goats, partly raw and partly boiled, and is here called Moldfoer” .blom, småblom [‘small ferns’] and storblom [‘large ferns’]. Storblom was, first and foremost, Matteuccia struthiopteris. In Vesterålen, Athyrium filix-femina is called pil, and some called it blindpil because if livestock consumed too much of it, they become blind.” He assumed that this was just superstition, because he had never heard of an actual case of such poisoning. According to his experience, the main species utilized for fodder was Dryopteris filix-mas: “(…) and this they called mollfor, it was frequent in Vesterålen as well.” It was mainly used in spring (EBABM 1990:12).From Vesterålen in northernmost Norway, a very interesting account is available from a man who had worked as a teacher at an agricultural school for decades. Through his work, he had become acquainted with local practices related to additional fodders, including fern rhizomes. He was also able to identify some of the species used: “In northern Norway, ferns are called Matteuccia struthiopteris and Athyrium filix-femina were the main species utilized there  as the source of the rhizomes used for fodder: “Mollfôr fern roots of Skogburkne (…)” . With no specimen provided, or any further information, it is difficult to evaluate if this latter identification was correct or not.My own records from the Harstad area in SE Trom suggested that d there (: 378), wmollfór when the scales of the root  are round. Telg if they are flat. It is only the root that is called mollfór or telg. All ferns  are designated with a common name, blom.” ” ” (: 202).moldfôr for fodder use. These remain the only voucher specimens (in herb. TRH) documenting the practice. In April 1763, Gunnerus requested specimens of three different ferns or folk taxonomic units from chaplain Adrian Bødtker in Tromsø (Troms). In due course, he must have received the relevant material, for as noted by Ove Dahl  proved to be Matteuccia struthiopteris, which may also have been used. The third species, Teisk or blind Teisk, with is pejorative name, was obviously avoided, and here as elsewhere, the dangerous kind turned out to be Athyrium filix-femina. The year after, in 1764, Gunnerus received a specimen of mollfor from E.G. Schytte in Lyngen, Troms; it proved to be Dryopteris filix-mas , trvegicia . Thus, flix-mas (: 289).Matteuccia struthiopteris have also been collected for fodder, but were considered less valuable than those of Dryopteris spp. , the best kind, and pil, which was Matteuccia struthiopteris (EBATA 2009:4). Matteuccia was also the prime resource utilized in Sørreisa, Troms: “It was mainly the root of strussvinge  which was used for fodder. In some places in warm, sun-facing slopes there may be large stands of this fern, with a little ormetelg [= Dryopteris filix-mas] in between. Thus, it is likely that the root of ormetelg was also taken. In our area, people knew the tradition of collection blomrot as an emergency fodder. I have participated myself, as a little boy. As far as I know, the practice has now ceased.” ( and Euopean bird cherry [Prunus padus L.], (…)” (NEG 11: 2763).Rhizomes of is spp. (: 766). Asee also : 26). AtDryopteris filix-mas] was called Telg. Strudseving (Struthiopteris germanica) [= Matteuccia struthiopteris] was called Tiske, or Tisketelj. Moldfor was a common name. Oddly, in this area the former was considered less good than the latter. Further north – in Lyngen, Nordreisa, Skjervøy and Kvænangen, it was the other way round.” (…) “In Balsfjord, people also said that it was not advisable to feed the animals too much telg, because they could get ill. When I asked if this was not due to trollmoldfor, which is said to be poisonous, people denied it. To make sure that there was no mistake in the names applied, I went out in the field and collected both telg and strudsvinge. They were correctly pointed out [by the locals], so the difference from areas further north is real.” (NEG 11: 19292). Mejland received similar information at a second locality in Balsfjord, again with Matteuccia struthiopteris identified as moldfôr, and the preferred species, whereas telg or Dryopteris filix-mas was regarded as inferior. (NEG 11: 20628). At Takelvvannet, Mejland’s third locality in Balsfjord, tradition was similar to that further north, and Dryopteris filix-mas the preferred source of moldfôr for fodder, and Matteuccia struthiopteris a less desired alternative (NEG 11: 21600).The botanist Yngvar Mejland contributed extensively to the NEG archive, providing a number of reports on additional fodders, in which the fern species harvested for rhizomes are identified. A record from Balsfjord is typical: “Now, people have ceased using roots collected in the field. But until the first world war, this was done, and rarely later. In the childhood days of my informants this was still rather common, and in the past  everyone used roots to feed the animals. It was fern roots that were used. In Balsfjord, ormetelg (Polystichum filix mas)  = saumoldfor and Struthiopteris germanica [Matteuccia struthiopters] = kumoldfor” (NEG 11: 16672). According to Mejland’s note, people had to avoid Aspidium spinulosum  animals starting to swagger, and their hind part became lame, so that they were sitting. In the worst cases, they had to be slaughtered.” (NEG 11: 16672). At Eibydalen in Alta, Finnmark, the effect of poisoning was described in similar terms: “If the animals ate much trollmuldfor, their hind legs were lame, and they were sitting in their pens – and could die.” (NEG 11: 21066).The practice in neighbouring Kvænangen was much the same: “The ferns people collected were Maullfor og Graste (Osmunda struthiopteris and Polypodium filix mas), of which the two latter kinds produce near the root thick, inside (when they have been broken apart) cabbage-green leaves in the form of an artichoke, which, when they are boiled and pulled apart, give the livestock a well-tasting fodder.” Sommerfelt’s account thus also singles out Matteuccia struthiopteris and Dryopteris filix-mas as the main sources of fern rhizomes for fodder use, seemingly identifying Maullfor with the former, and Graste with the latter. Graste is perhaps just a misreading of Sommerfelt’s manuscript, approaching the more well-known term Grofte, which would look very similar in Gothic script. In all likelihood, he based his account on local tradition in Alta, where he resided.An early identification of the useful fern species is found in country prefect Ole Hannibal Sommerfelt’s topographical description of Finnmark, Norway’s northernmost county, in 1799 (: 118). HMatteuccia struthiopteris was present in sufficient quantity to yield much in terms of fodder: “Fern roots have been used to some extent, in particular Struthiopteris germanica [= Matteuccia struthiopteris]. Ormetelg [= Dryopteris filix-mas] is very rare in Tana.” (NEG 11: 19729).In Tana, only Blechnum spicant served as a source of rhizomes for fodder use. The records derive from coastal areas in Brønnøy and Bodø: Kjerringøy , where the species occurs abundantly, and utilization cannot thus be ruled out, despite the fact that its rather small rhizomes suggests that collecting material would be an ardous task. Høeg cites only the former record in his published compilation .FigAthyrium filix-femina as poisonous and harmful , folk tradition in northern Norway is uniform in singling out isoning : “As to the knife in question, it was made from a broken scythe, broken in the middle as shown by the drawing. It was the pointed end that was used. At the hind end, a rag was coiled to avoid harming the hand. One used the left hand to grab the fern at the base, and with the right hand, one would insert the knife in the soil, and turn it around the base to cut the roots, which are well attached.” . In Steigen, fern rhizomes “were picked up with a hoe and brought home in sacks and stored in large piles in a shed.” (NEG 11: 1644). At Vågan in Lofoten, “they used a hoe to dig it up” (NEG 11: 2463). At Andøya in Vesterålen, a knife was used to extract the rhizomes: “(…) they were cut off with a knife, and then dried, before being used as additional fodder.” (: 13). Atmoldfôr was taken here in the autumns. In this area, it was mostly people from Kjerringvik and Valfjord who carried out the harvest [of rhizomes]. The tool they used, was a long knife. One made a cut around the root, grabbed the plant, and pulled the moldfôr out of the soil. It was slow and painstaking work, and it was often carried out for several days. When the day’s work was completed, one collected the rhizomes in sacks and carried them to [the boulder called] Moldfôrsteinen. Here, they were poured out of the sacks, and heaped in piles [and stored] until the snow appeared. There was no need to cover the store. When the ground was covered by snow, the moldfôr was fetched with a toboggan or sledge” .moldfôr knife – “but I didn’t know what it was.” “It was truly a moldfôr knife, they said” – presumably to suggest that it could no longer be used for anything else . Ang else (: 378). Amoldfôr or rhizomes loose. No matter what kind of tool people used, extracting the rhizomes usually required some digging, which is certainly necessary e.g. for Dryopteris ssp. The only exception to this rule seems to be Matteuccia struthiopteris, where a substantial part of the rhizome may protrude above ground. A man from Sortland in Nordland noted that it could be collected by a deviant method: “Referring to that pil … They collected it later in the year, when the ground was frozen. Then, it was almost above ground. They hit it with a club” – and this was sufficient to get it loose; there was no need for digging it up. (EBATA 2009:4).Thus, in general, some kind of knife or other utensil was used to cut the Limited information is available on the time of year when rhizomes were collected. According to Jens Holmboe, the work was frequently done in autumn, and the rhizomes stored in piles until need arose – usually in late winter or early spring (: 765). Tgrofterot in the autumn.” “In the autumn, people did not collect grofterot. This may be due to the late cessation of other autumnal work; when completed, the frost usually appeared, and perhaps even snow. Therefore, the roots had to be taken in spring.” (NEG 11: 1708). The record also provides details on use: “Grofterot was considered an additional fodder. The rhizomes were supposed to have substantial value as fodder, but were otherwise not highly regarded as far as I have heard, and as fodder, it was not accepted by all the animals. When used, they were chopped into small pieces, and preferably served along with kitchen refuse or with fish remains. It was mainly the cows who were served grofterot.” . Knut Strompdal’s record from Velfjord in Brønnøy, Nordland provides a detailed account, referring only to collection in spring: “The roots were not stored for any length of time, [but] they could be left standing in a box or some other container until they were used. I have never heard of anyone collecting cited in : 327).At Elsfjord in Vefsn, Nordland, people collected rhizomes “in spring” , whereas the harvest in Beiarn could be carried out both in spring and autumn: “Some would dig up the roots in the autumn and let [them] lie outdoors, but most of it was dug in spring and used as additional fodder for the cows.” .telli or Matteuccia struthiopteris, and bring the rhizomes home. Their handling was simple: “They were placed in luke-warm water, washed clean, and then carved up and given to the livestock” .moldfor” (NEG 11: 1644). Another record from Steigen is more restricted in terms of the recipients: “Mollfór, the root of larger ferns, for goats and sheep.” .moltfòr.” (…). “From the very start of the autumn the women were up in the moltfòr slope digging roots for the sheep, the small animals, because the fodder collected during the summer was insufficient.” .Moldfór was collected in the autumn. It was usually boiled before it was used. The decoction had a finer scent than that of hay.” . Amollfor, which they stored in the barn.” The informant himself had not participated, but knew the practice through his father  it was a whole work season. People would scythe the outfield and infield areas. Afterwards, they brought home the 1990:10; : 14).blom. The roots were cut in the autumn, and carried home in a sack. One could also chop roots and leave them well into spring” (NEG 11: 22600).A record from Skånland in SW Troms provides some further details in terms of how the rhizomes were handled: “They used it a lot in spring, [it] was crushed with the back of an axe, and parboiled, often together with fish offal.” . Itrollblom, which was poisonous.” If need arose, rhizomes could also be collected in spring: “It frequently occurred in spring that people had to bring a spade to shovel away the snow to find the roots.” “Previously, large quantities of blom were used here.” (NEG 11: 22561).Yngvar Mejland provides an account of traditional harvesting in the Bardu – Målselv area of interior Troms: “In the autumn, people could cut large piles of roots [fern rhizomes], which were brought home in winter. From slopes far away, the roots were transported home on the snow crust in spring. People had to be aware of and avoid blomrot or Matteuccia struthiopteris (see below), but is more detailed in terms of the timing and mode of use: “It is mainly in spring, when the snow thaws in the slopes, and there is a fodder shortage, that people would use blomrot. But the root was also collected in the autumn, and placed in round piles. But this practice is now long since obsolete, but before and around 1900, and a little later, blomrot was used. It was chopped into pieces and mixed with seeds from the hay, light grain, awns and litter, a little horse dung, and perhaps some fine rowan bark, and a little salt was fine.” The whole mixture was boiled and served to the cattle. .moldfórhovver.” (: see also ). At EibIt rhizomes had been harvested in any quantity in the autumn, they would usually be brought home in winter, when the ground was covered by snow. A man from Sortland in Nordland had participated in this part of the process during his youth: “I can remember it from my childhood.” The harvesting as such was done by his father. “I only participated in dragging it home in winter.” (EBATA 2009:4).moldfôr (see above) undoubtedly refer to sites with large fern stand, in particular areas where rhizomes were collected. Exceptions occur, e.g. in Sortland, Nordland, where a boulder got its name from serving as a place to store rhizomes: “In the slope above “Dalstua” [a cottage] in the Holmstaddalen valley, there is a large boulder. It is about two meters high, and its lower side is slanting inwards, thus forming a hiding place. It was called Moldfôrsteinen [‘the fern rhizome boulder’], and it was a well-known landmark to people at Kjerringvika and in Valfjorden. Everybody was familiar with Moldfôrsteinen, for beneath it, the moldfôr was stored until the snow came. Nowadays, few if any know Moldfôrsteinen. They know nothing of the moldfôr either.” ( were collected, if only locally, in autumn, and given to the sheep.” He could not remember what they were called. Such use was long since obsolete: “far back in time, about 1860 I think, but my father probably used it around that time”. Local supplies were restricted, and the rhizomes were only considered an inferior kind of fodder (NEG 11: 2999).A single record of former use derives from Fyresdal: “The roots were collected in spring. During later years, this has been very rare, and such use has now ceased.” (: 326). Rburot here. It is ormetelg” [= Dryopteris filix-mas]”. The informant identified it as “Ormtegl”, i.e. Dryopteris filix-mas, but the description given of its habitat  does not really fit : “In the past, people gathered roots of a fern species which is called moldfôr was still remembered in the 20th century, but nothing is said in terms of collection and use: “There was a lot of mòlfor i Trettesriplann , and the second from Ullensvang, also in Hardanger, Hordland. According to the latter, the term riplann (: 69).Tælgroden is here regarded as the very best means of compensating for the lack of fodder, bus as far as I know, it is only found in a few places.”  “They cleaned the roots and gave to the cows.” . In this area, rhizomes were still collected in the early 20th century: “Sometimes, they were up in the screes and dug up the roots of telgblomen and gave to the livestock.” . Pe1, 1938; : 326); “stock.” (: 126). Tblom) were also collected and used for fodder in our part of the countryside some 70 or 80 years ago. Since then, this additional fodder has not been used – at least not to any extent. There were two or three different kinds of fern – blom – storblom [large fern], småblom [small fern] and bjørnekam [Blechnum spicant]” .grefte, as fodder, and it is not considered an inferior kind of additional fodder.” (…) “It is collected in spring. There are two localities here called Greftesli.” (. They went across the ice to Gufjellet and fetched turt and grøftrot for cattle fodder. Grøftrota was about the size of a closed fist. They put it in sacks. It was very helpful. They could have a whole load of it. The cattle were very eager. In spring, they saved the cattle with it. Grøfterota was their rescue.” . Aited by (: 326). Umolfor has long been known and priced as fodder” ” , Ter (…)” (: 372). AVærøy.” .Fern rhizomes have been collected throughout the county, e.g. at Bindal in the far south: “When there was a shortage of fodder, they collected  task.” (: 326). Illfór.” (: 327). TBlôm was also called målljfór-blom, because the roots [rhizomes] were used as cattle fodder.” , more so than others here, which may have used roots [only] in times of need, if they were accessible.” (NEG 11: 1820). The tradition’s concentration to the interior valley area is confirmed by a second record: “(…) but the old woman I mentioned above tells me than in the old days, fern roots were used for fodder (in Beiarn), but she could not provide further information.” . A later comment from the same informant was obviously based on a new source, noting that rhizomes “was used for cows. The roots were used raw, but first they were crushed” (…) “It was an important source of additional fodder in the upper part of Beiarn.” . HIn the NEG material, a man from Saltdal answered that fern rhizomes had not been used in his area, but he knew the practice from Vatnbygda in neighbouring Fauske, where it had “in the past been used every year, and in substantial quantity. It was considered a good fodder.” (NEG 11: 2810). Note, however, that rhizome use was recorded from Saltdal by Axel Hagemann in the late 19th century (: 44).Mollfór was collected as an additional fodder.” ([moltfór was used for cattle.” ([moltfórskogen” [‘the fern rhizome forest’] and fetch roots for cattle fodder.” ( collected in the outfield areas, and a little molfôr [fern rhizomes]” .In Steigen, ferns constituted part of the fodder available. According to a note made in the 1950’s, the fodder for “two or three cows and some minor livestock consisted largely of grass and zomes]” (: 100). ADryopteris expansa as moldfôr in Hamarøy has been mentioned above. A second record from this area provides little in terms of details, saying only that “The root of a fern species was dug up in autumn, for fodder.” . Tng it.” (: 327).moldfor was collected during the period of spring shortage, but now this has completely ceased.” (NEG 11: 1796). The sole record from Lødingen is even less detailed:, noting only that “Mollfor, Blomrot. The root is used as additional fodder.”  “The subterranean stem was as thick as the handled.” (NEG 11: 2463). “The roots of blomm” (…) “as mollfór, preferably for cows. It was usually chopped, and warm water poured over (to soften).” , which is likely to have been Matteuccia struthiopteris: “Mollfór is the root of ferns, which is used as fodder for cows and sheep. Pilmollfór is less good, it grew among the stones in damp areas. Blindmollfór, it caused the cattle to go blind.”  you will often find there.”  «This kind was called pil because when the fern had withered, some high leaves were left standing, which looked like the tail of a bird.”  «The one we used, was godmollfor.” It was last used in 1945 or thereabout: “He was here just after the war and collected some mollfor. Since then, I have not heard about anyone who did so.» (EBATA 2009:4).Tradition at Sortland in Vesterålen was much the same, adding a third kind (blind.” : 327). Athere.” (: 124). I7. Athereormetelgen [= Dryopteris filix-mas] they used and designated as moldfór. Skogburkne [= Athyrium filix-femina] and geittelg [= Dryopteris dilatata] they called blindmoldfór. I suppose it is geittelg that elsewhere in Hadsel are called pil and blindpil due to the shape of the leaves.” . In addition, the plants found in this area are now regarded as belonging D. expansa rather than D. dilata, and as shown by records elsewhere, there is nothing to suggest that the latter species was harmful. People may, however, have found that it looked confusingly similar to Athyrium filix-femina. Another account from this area, cited above, is detailed in terms of the utensils used, and less so in terms of the result: “The roots are cut away from the plant [rhizome]. They stored it in large piles until it was transported home.” . I was told that it was eaves.” (: 327). T home.” (: 327).Mollfór was also collected during the war 1940–1945. They had mollfór and blindmollfór.” (. The real [i.e. useful] ones are round, long roots which are green, and have a sweet taste. I do not know which fern species these roots belonged to.” . A slightly more detailed record is available from Langøya: “From  1990:9, : 14). A 1990:10; : 14).mollfor.” . Ct was.” (: 378). At was.” (: 328).blom [ferns] that were collected for fodder, namely moldfor, telg and teisk. But I do not know what ferns the names refer to.” (…). “Moldfor was considered a fine fodder, but telg and teisk were less good” (NEG 11:3413). Unfortunately, the record provides no clues as to the identity of the three (or possibly more) species collected. In this area, the use of fern rhizomes may have ceased in the first decades of the 20th century: “In the old days, mollfór was considered an additional fodder, not a rescue fodder, for at some farms, it was gathered every year. But nothing has been collected during the last 40 years.” (NEG 11: 3413). In Gratangen, a toponym reflects the tradition of collecting fern rhizomes: “There, you will also find Moldfôrholla, where they dug roots, for fodder.” (EBATA 2005:9). A record from Salangen has been cited above.At Ibestad, people discriminated between three kinds of ferns when harvesting rhizomes for fodder, according to a 1950’s record: “The old people had three names for the Telgen, its nutrient store  was used as cattle fodder during the period of spring shortage. We had a place-name Telgelia.” (EBATA 2014:27). Unidentified fern rhizomes were also collected at the major island of Senja: “(…) but in Vesterålen and in Berg, during the spring shortage, they dug up the roots of the large fern” (…) “in the slopes, for fodder. This they called moldfór.”  was harvested, dried and used as livestock fodder. In addition, the roots were dug up for fodder (moldfor), and these practices may have been a good reason for making toponyms.” (…) «In one locality [out of six listed], ferns are absent today, but one informant (born 1906) knew that they had dug moldfôr here in the time of his parents” .blom [ferns], one was mollforrot, the other was storblom [large fern]” (…) “It was used before her time. They cleaned the root [rhizome] and cleaved it in two halves.” Inferring that mollforrot came from a smaller fern, the sources of rhizomes for fodder may have been Dryopteris expansa or D. filix-mas. In Salangsdalen, such use was rare, at least in the 20th century: “[We did not use] blomrot in any quantity, only now and then.” (EBABM 1989:11). The larger species may also have found local use: “Strutsevinge [= Matteuccia struthiopteris] we call blomrot.” (…) “It was used to somewhat after 1900.”  “has a smaller root, and the blom [frond] is also smaller. The lowermost part of the stem is smooth, without spines. It is the best root for livestock fodder, but it is less frequent in the forest.” As elsewhere, Athyrium filix-femina was known, but not used: “Teskrota” (…) “deviates from the others in that root neck, the lowermost part of the stem, is flatter and has spines along the rim. It is of about the same size as the previous one, both in terms of root and leaf. It forms bundles in the forest. The root was not used for fodder.” . Aodder.” (: 328). UMollfor. [It was] cleaned and chopped into pieces.” . A 989:5–6; : 14). Thmållfor-root was a fine fodder during the spring shortage. Telg and tisk are useless.” (…) “The base of the leaf stems are round in mållfór, whereas it is triangular in telg and tisk, somewhat broader in telg.” : “The 1; 1938; : 328). Pskav [rowan bark] and Multefoder [fern rhizomes] for their livestock, (…)” ” (: 7). A rerns].” (: 328).Dryopteris filix-mas and Matteuccia struthiopteris. “Only these two kinds of fern are used. At least until 1935, mollfór was a frequently used emergency fodder. It has been less used since then, but due to the lack of manpower, people will not go far to collect it. Previously (until about 1935) people could travel tens of km to “cut mollfór”” (NEG 11: 4688).At Kåfjord, the use of fern rhizomes had ceased long before the NEG questionnaire was distributed in 1948. “In the valleys of Kåfjorddalen and Manndalen, roots have been little used recently. Only way back in time, fern rhizomes were used in quantity. Younger people had no idea when I asked them. But older people could remember it, and according to their account, the practice was as in Nordreisa.” (NEG 11: 16673). An unusual array of records is available for the latter area. Excerpts of a detailed account given by Yngvar Mejland have been cited above. According to him, fern rhizomes “were regarded as a good fodder, and previously, until about 1915, it was used as an additional fodder at most farms in the area.” The species harvested were moldfôr, he provided a brief account: “Oh yes. In autumn, we prepared large piles of mollfor in the forest, which we brought home [in winter]. And we continued with this until 1940.» (…) «I accompanied my father-in-law collecting mollfor. It was mid-summer’s eve, and the snow was still piled so deep it reached the belly of the horse.” (…) “We pulled up mollfor in autumn and stacked it, and brought it home in spring or whenever it suited us. We could also fetch it earlier in winter; there was no fixed date for doing so. It was when it was needed. In Finnish, mollfor is called gaiski.” He went on to provide further details, noting that there were different kinds: “There is sau-mollfor [‘sheep-mollfor’] and ku-mollfor [‘cow-mollfor]. Sau-mollfor is a different kind. It is somewhat smaller, but it is much better. Ku-mollfor is more dry, and it is much larger. I can show you the two kinds in summer”   are easily available: “I remember once they collected mollfor beneath the Solheim-bakken slope, it was chopped and made [ready]. But the cows would not eat it; they were not that hungry.” (EBABM 1991:2). At Kvænangen, in the far northeast, Troms, fern rhizomes were previously an important source of fodder. “Now, all use of roots as fodder has ceased in Kvænangen. The practice was abandoned before the last war.” (NEG 11: 16672).A man from the Nordreisa valley of had participated in collecting fern rhizomes in the early 1940’s. Asked if he knew the tradition of using  1991:3; : 14). StMolfoder , which is the root of a plant, that look like the well-known Ormegræs. A variety of it is called Groste and is considered inferior.” .grofte and mollfor. And the cows were very fond of it.” She was not sure if these terms designated two different species; grofte may have been used to designate the plant as such: “No, (…) it was two different things. It was the root. It [the fodder] was mollfor, and it was like a small kohlrabi.” They had to cross the Bognelva river to find it, which means that in this case, Matteuccia struthiopteris can be ruled out – it is abundant on the valley floor on both sides of the river. She could not offer any other details than that the species used was “stiff”, which may point to Dryopteris filix-mas, with its rather dry and hard fronds. Perhaps other species were known or used as well, as suggested by an additional comment: “There were several kinds. One was more sharp, and a little darker” – which partly complies with the descriptions given elsewhere of Athyrium filix-femina and the “spines” at the base of its stipes. The last use of fern rhizomes had occurred just after World War II (EBATA 2007:45).At Bognelvdalen in Alta, rhizomes were a well-known source of fodder in times of need. Asked if (birch) leaves were used, my female informant replied: “No, not leaves. If it was a bad year, we had a place where they dug up something they called ormegresset, but one would also collect som muldfor. Trollmollfor had to be avoided. One recognized it by the spines at the base of the leaves» (NEG 11: 21066) – a description that once again identifies Athyrium filix-femina as the harmful species. At Kviby, the larger ferns were infrequent, but the locals “knew that about 100 years ago, people had collected some fern roots in a slope” (NEG 11: 22284).The NEG material includes a record from Eibydalen in central Alta: “One has collected some fern roots for fodder.” (…) “The best kind was At Nuvsvåg in Loppa, “the larger ferns do not grow here in any quantity, so their roots were but little used.” (NEG 11: 21367), whereas an informant from Bergsfjord had no knowledge of such use (NEG 11: 9794). A sparse or absent tradition of using fern rhizomes for fodder in Loppa is confirmed by an 18th century source. According to a letter from vicar S. Bang to bishop J.E. Gunnerus, dated July 20, 1763, “moldfor is not used in Loppa” (: 29).blommerøtter . At Sør-Varanger in the far east of Finnmark, two informants from Neiden and Jarfjord both both noted that the larger ferns were infrequent, and thus they had no knowledge of using the rhizomes for fodder .Further east, at least people in Lebesby collected fern rhizomes for fodder, under a deviant name, 1, 1955; : 329). ARhizomes of some fern species are poisonous or otherwise harmful if used as fodder Table . Accorditrollrot (“troll root”) and blindrot (“blind root”) are typical examples , to separate it from the useful species, i.e. Dryopteris and Matteuccia struthiopteris . Imoldfôr were harmful, e.g. at Bleik in Andøy, Nordland: “Grandma Anna tolds us about mollfor which was poisonous, and she called it blindfor. The animals could loose their sight.” (EBATA 2005:51).Some records merely show that people knew or believed that some kinds of gáiski, translated as “the root [rhizome] of various fern species” by Just Qvigstad  neighbours, including the use of fern rhizomes as an additional source of fodder. Most, but not all Sámi fern names are adaptions of Norwegian terms. In all likelihood, the species selected for fodder use were also the same, although the available material is fragmentary and partly misleading. In the far north (Troms and Finnmark), ferns and fern rhizomes are mostly designated as vigstad (: 320). Fd delgi  as gaiske banekætta (‘toothless fern rhizome’) and sapak gaiske (‘black fern rhizome’), the latter combining the adjective sáhppat, which is more correctly translated as dark or blackish blue, the kind of colour seen in some ripening berries, or in effusions of blood, and gáiski, ‘fern (rhizome)’. Both were identified as Matteuccia struthiopteris, whereas Athyrium filix-femina was called stálogáiski and bánegáiski. The former is pejorative, stállu being an evil but stupid giant that troubled the Sámi. The latter refers to a characteristic of the rhizomes – they have “spines” or “teeth”, cf. the Sámi term bátni, ‘tooth’. As we have seen, the absence of “teeth” on the rhizomes of Matteuccia and other useful fern species is confirmed by Holmboe’s study of how Norwegian farmers discerned between the useful and harmful kinds ( is rare here, whereas strutsevingen [= Matteuccia struthiopteris] is [still] found in large stands.” (NEG 11: 4688). Thus, the extensive past use of fern rhizomes may have had consequences in terms of species composition in the vegetation. Jens Holmboe  noDryopteris filix-mas and Matteuccia struthiopteris as the main source plants. The latter may form vast large stands in the larger river valleys, and is thus easily available for exploitation. Dryopteris filix-mas is usually found growing among other ferns, and requires more effort in terms of locating. It is more frequent in the interior valleys than at the coast, and both the study of Jens Holmboe [Dryopteris expansa is a much more frequent species, and as shown by some recent records, it was locally the preferred source of fern rhizomes. Thus, for northern Norway in general, the data so far available may have over-estimated the use of D. filix-mas, and overlooked D. expansa as an important, alternative source. Rhizomes of Dryopteris filix-mas and Matteuccia struthiopteris were used for fodder in Sweden as well, as recorded by Anders Jahan Retzius in 1806 , buAthyrium filix-femina as harmful and poisonous, allegedly causing lame hind legs and blindness in livestock, there is hardly any toxicological data to support this in terms of the rhizomes. Fresh shoots are poisonous due to their contents of thiaminase, which is destroyed if dried or boiled – which the rhizomes usually were, before being served as fodder. Feeding livestock with fresh rhizomes collected in late spring, complete with their sprouting buds or fiddleheads, could perhaps lead to poisoning. Matteuccia struthiopteris is one of few fern species gathered in any quantity (as young shoots or “fiddleheads”) as food for humans, e,g in North America ([Athyrium filix-femina is used in the same way the U.S. Diplazium esculentum (Retz.) Sw. (syn. Athyrium esculentum) is eaten in East Asia and the Pacific area. As pohole, it is a food speciality of Hawaii ,  Hawaii (: 1837).  Hawaii (: 444). I fooder . On the other hand, fern rhizomes were eagerly collected when available – 94 % of the 48 farms with access to fern rhizomes reported that this resource was “utilized in full” [The past use of fern rhizomes for fodder is difficult to quantify. Based on data collected for taxation purposes in the 1860’s, I have previously extracted information on the use of various additional fodders in the municipalities of Harstad and Kvæfjord in southwest Troms, North Norway . Accordiin full” .The extensive Norwegian use of fern rhizomes for fodder seemingly has no parallel anywhere else. There is no information on such use in any of the major scientific databases . Although such use has been recorded in Sweden and Finland as well, it was of little importance there, and rarely practiced. It was hardly practiced in the Norse overseas settlements eiher – for the simple reason that neither the Orkney or Shetland islands, the Faroes, Iceland or Greenland provide much in terms of ferns for harvesting. The suitable species are, as pointed out already by Fredrik Rode in 1832, in his case referring to Finnmark, mainly found in forested areas, and for this reason, to quote Rode, it was “an additional fodder which is only available to people living in areas, where woodlands are found” (: 26). FeMatteuccia struthiopteris and Dryopteris filix-mas, more locally also Dryopteris expansa, whereas Athyrium filix-femina was generally, but not always, considered poisonous and harmful, and thus avoided. The core area of such use is found in the two North Norwegian counties of Nordland and Troms, where the practice locally survived into the 1950’s.Fern rhizomes have a long tradition as one of many kinds of additional fodders in Norway, mainly among the ethnic Norwegians. Preferred source species were Fern rhizomes are only likely to find fodder use in northern areas combining at least some agriculture with long winters and woodlands supporting large stands of ferns – and Norway, in particular its northern parts, fits this description perfectly. There are hardly any other areas anywhere where agriculture is carried out at such high latitudes, and still within birch-dominated forest areas providing access to abundant stands of some of the larger fern species, and thus their rhizomes.


AR) are associated with resistance to therapies targeting the androgen/AR axis in patients with metastatic castration resistant prostate cancer (mCRPC). Due to limitations associated with biopsying metastatic lesions, plasma derived cell-free DNA (cfDNA) is increasingly being used as substrate for genetic testing. AR mutations detected by deep next generation sequencing (NGS) of cfDNA from patients with mCRPC have been reported at allelic fractions ranging from over 25% to below 1%. The lower bound threshold for accurate mutation detection by deep sequencing of cfDNA has not been comprehensively determined and may have locus specific variability. Herein, we used NGS for AR mutation discovery in plasma-derived cfDNA from patients with mCRPC and then used droplet digital polymerase chain reaction (ddPCR) for validation. Our findings show the AR (tTC>cTC) F877L hotspot was prone to false positive mutations during NGS. The rate of error at AR (tTC>cTC) F877L during amplification prior to ddPCR was variable among high fidelity polymerases. These results highlight the importance of validating low-abundant mutations detected by NGS and optimizing and controlling for amplification conditions prior to ddPCR.Somatic genetic alterations including copy number and point mutations in the androgen receptor ( The use of cell-free DNA (cfDNA) as a “liquid biopsy” to detect cancer biomarkers is an emerging and promising area of cancer research. Small amounts of circulating cfDNA can be detected in plasma from healthy individuals , is ofteESR1 and androgen receptor, AR have been identified following progression on targeted therapies [AR status in cfDNA in men with metastatic castration resistant prostate cancer (mCRPC) showed that AR gene aberrations such as gene amplification or ligand binding domain (LBD) mutations are associated with worse outcomes following next generation therapies that inhibit the androgen/AR axis such as abiraterone and enzalutamide [AR status as a biomarker for therapy resistance.Somatic alterations in steroid hormone receptors such as estrogen receptor (ER)α, herapies –12. The herapies –17. Anallutamide , 15, 17.AR mutations detected by deep sequencing of plasma-derived cfDNA have been reported at allelic fractions as low as 0.11% [AR mutations discovered by deep sequencing cfDNA from patients with mCRPC by ddPCR.Translation of preclinical findings using cfDNA into a robust clinical test will require further technical considerations. Discovery of low-abundance somatic mutations among normal cfDNA poses challenges for rigorous clinical application. as 0.11% . AnalytiWe prospectively enrolled 11 patients treated at Johns Hopkins Hospital  and Sibley Memorial Hospital (Washington D.C.) for mCRPC. Patients had histologically confirmed prostate adenocarcinoma, progressive disease despite androgen deprivation therapy, and documented metastatic disease by computed tomography (CT) or bone scan with technetium-99m-labeled methylene diphosphonate. Plasma-derived cfDNA was isolated from all patients prior to initiation of enzalutamide therapy. Patient characteristics at plasma collection are summarized in Table AR mutations on the Illumina HiSeq. Plasma derived cfDNA from two healthy donors  was also amplified and sequenced. The AR (TGg>TGt/c) W742C hotspot mutation was detected in one patient at an allelic frequency of 0.46% (Table AR (aCT>gCT) T878A hotspot mutation was detected in one patient at an allelic frequency of 0.42% (Table AR (tTC>cTC) F877L hotspot mutation was detected in approximately 45% of the patients (n=5/11) at allelic fractions between 0.20-0.28%  L702H and AR (cAT>tAT) H875Y were not detected in any of the patient samples or controls  mutation by ddPCR at very low allelic fractions ranging from 0.007 to 0.033% (Table AR F877L (tTC>cTC) mutation by ddPCR while non-amplified wild-type genomic DNA was negative suggesting that the AR F877L mutation was introduced prior to ddPCR during preamplification with Phusion®  lower allelic frequencies (0.004 to 0.011%) than the AR F877L mutation  F877L and to a lesser extent AR (aCT>gCT) T878A are prone to error during Phusion® mediated PCR amplification while other AR loci such as AR (TGf>TGt/c) W742C may not be.We next examined patient samples and wild-type genomic DNA preamplified by Phusion® and Platinum SuperFi™ for wild-type AR F877L and AR T878A may mediate resistance to androgen-AR axis therapies such as enzalutamide, we examined for an association of AR gene aberrations including AR LBD hotspot mutations and AR amplification with enzalutamide response. AR amplification was determined by ddPCR (AR gene aberrations (AR hot spot mutations and AR amplification) support that AR gene aberrations trend, but not significantly, with a worse PSA response as measured as best PSA percent change (>0 versus ≤0) by Fisher's exact test  tests  tests . Signifid by NGS . While tfindings , 15, 17.AR including splice variants [AR have been shown to occur in 5-18% of patients with mCRPC [AR amplification [AR status as a biomarker to guide therapeutic decisions for men with mCRPC.Mainstay treatment strategies for newly diagnosed metastatic prostate cancer exploit prostate cancer addiction to AR signaling by inhibiting the androgen/AR axis with androgen deprivation therapies (ADT). While ADT is initially effective in most men, prostate cancers almost universally recur after a variable amount of time leading to mCRPC. Despite androgen blockade, the majority of newly diagnosed mCRPC are thought to have continued dependence on androgen signaling. Similar to first line ADT, next generation therapies for mCRPC such as abiraterone and enzalutamide also function by inhibiting androgen/AR signaling. Somatic alterations in variants –26 and gvariants , 15, 17 th mCRPC , 27, 28 fication . ConsequAR status in patients with mCRPC using traditional metastatic biopsies poses several clinical challenges including cost, patient discomfort, sample collection, and lack of ease for serial analyses. Single site biopsies may also not account for tumor heterogeneity. Due to these limitations, many rapidly developing technologies have focused on revolutionizing the detection of tumor specific genetic alterations in the blood as a “liquid biopsy”. Use of cfDNA as a tumor analyte combined with NGS as a platform for detection show great promise in the clinic as a means for mutation detection and monitoring. While these technologies have demonstrated proof of principle, further optimization and validation is necessary to define parameters for sensitivity and specificity. Concerns currently exist pertaining to the rate of false positives and the associated potential clinical ramifications. NGS of cfDNA for the detection of tumor specific mutations often involves polymerase based amplification which can introduce errors. While NGS approaches such as SAFESeqS [Evaluating and monitoring SAFESeqS  and DuplSAFESeqS  may dramAR by NGS of plasma-derived cfDNA from patients with mCRPC and then to cross-platform validate by ddPCR. Our findings suggest variability in polymerase fidelity at specific AR LBD hotspot loci. We demonstrate that some high fidelity polymerases used for preamplification prior to NGS and ddPCR can introduce low level mutations at AR LBD hotspot F877L and to a lesser extent at AR T878A. Interestingly, other AR LBD hotspots such as AR W742C did not show false positives by any of the tested polymerases. Sequence differences between these loci were not readily appreciable as they contain comparable GC content and single and dinucleotide repeats . We prospectively enrolled patients diagnosed with metastatic castration resistant prostate cancer (mCRPC) (n=11) between September 2014 and April 2015 prior to initiation of enzalutamide. PSA progression was determined at the date of the first PSA rise that was followed by a subsequent PSA rise or at the date of physician determined change of therapy. All patients provided written and informed consent to participate in the study. Two healthy controls also participated in the study. Three 10 ml blood samples were collected in Streck BCT tubes prior to therapy initiation, stored at room temperature, and processed for plasma isolation within 24 hours. To optimize patient sample integrity and to limit DNA contamination, plasma was extracted in a bleach and UV cleaned hood specifically for plasma extraction in a room dedicated for blood processing, storage, and cell-free DNA isolation. Plasma was extracted from blood by centrifugation for 10 minutes at 1500 x g followed by a second centrifugation for 10 minutes at 3000 x g as previously described , 32, 33.AR hotspot variants were additionally examined using the Integrative Genomics Viewer (IGV) http://www.broadinstitute.org/igv/. Variants that passed these filters were then validated by ddPCR. Variant calls were made independent/blinded to outcome data.GeneRead™ DNAseq Targeted Panel V2 (Qiagen) was used to prepare libraries from cfDNA for NGS as per the manufacturer's protocol. NGS libraries were prepared in dedicated bleach and UV cleaned hood. Samples were PCR amplified using Qiagen HotStar Taq as per the manufacturer's protocol. Libraries were amplified using Qiagen HiFi PCR Master Mix for 4 cycles. NGS was performed on the Illumina Hi-Seq with an average depth of coverage of 10,000x. Data was aligned to hg19 using bwa-0.7.7 (mem function). SAMtools was used to filter reads by quality (Phred ≥ 25 and mapQ >18 were included). The threshold for non-reference reads was 15 and single strand variant calls, non-reference reads less than or equal to 0.15%, non-reference reads less than twice the next highest non-reference frequency, variants in more than 50% of the samples, and variants over 50% of the allelic fraction were excluded. AR amino acid 742 and AR amino acid 877/878 for either 12 or 22 cycles. PCR amplification primer sequences are located in AR W742C, AR F877L, and AR T878A mutant control DNA for ddPCR were double-stranded purified DNA gBlocks®Gene Fragments (IDT) of approximately 400 base pairs that were reconstituted in RNAase free water. The non-amplified no template control had RNAase free water without template.Control genomic DNA (Promega) was digested with MseI (NEB). Genomic DNA, patient cfDNA, and water (no template control) were PCR amplified using Phusion® with Phusion® HF buffer (NEB) or Platinum SuperFi™ (Invitrogen) at loci surrounding AR hotspot mutations  and their respective wild-type loci. Sequences for ddPCR primers and probes are located in AR (ABI Hs04121925_cn FAM), ZXDB (ABI Hs02220689_cn FAM), and NSUN3 (Bio-Rad dHsaCP2506682) were used to determine AR copy number. Samples with AR copy number greater than or equal to 1.9 were defined as having increased AR copy number. Wild-type control genomic female and male DNA (Promega) digested with MseI for AR or HaeIII for ZXDB were used for AR copy number controls. Cell-free DNA from healthy male and female donors was also used as a control. Droplet digital PCR (Bio-Rad) was performed in a dedicated UV equipped hood and according to the manufacturer's protocol. Total WT and mutant DNA molecules were quantified by the QX200 Droplet Reader software. Results for each mutation analysis were recorded as the summation of four or more replicates.Dual labeled (FAM or HEX) fluorescent-quencher hydrolysis probes (IDT) were designed for P values less than 0.05 were considered statistically significant.Statistical Analyses were performed using GraphPad Prism software. All statistical tests were two-sided and


The potential of augmented reality (AR) technology to assist minimally invasive surgery (MIS) lies in its computational performance and accuracy in dealing with challenging MIS scenes. Even with the latest hardware and software technologies, achieving both real-time and accurate augmented information overlay in MIS is still a formidable task. In this Letter, the authors present a novel real-time AR framework for MIS that achieves interactive geometric aware AR in endoscopic surgery with stereo views. The authors’ framework tracks the movement of the endoscopic camera and simultaneously reconstructs a dense geometric mesh of the MIS scene. The movement of the camera is predicted by minimising the re-projection error to achieve a fast tracking performance, while the three-dimensional mesh is incrementally built by a dense zero mean normalised cross-correlation stereo-matching method to improve the accuracy of the surface reconstruction. The proposed system does not require any prior template or pre-operative scan and can infer the geometric information intra-operatively in real time. With the geometric information available, the proposed AR framework is able to interactively add annotations, localisation of tumours and vessels, and measurement labelling with greater precision and accuracy compared with the state-of-the-art approaches. While MIS offers considerable advantages over open surgeries, it also imposes big challenges on surgeons’ performance due to the well-known MIS issues associated with the field of view (FOV), hand–eye dis-alignment and disorientation. Augmented reality (AR) technology can help overcome the limitations by overlaying additional information with the real scene through augmentation of target surgical locations, annotations , labels Despite recent advances in powerful miniaturised AR hardware devices and improvements on vision-based software algorithms, many issues in medical AR remain unsolved. Especially, the dramatic changes in tissue surface illumination and tissue deformation as well as the rapid movements of the endoscope during the insertion and the extrusion all give rise to a set of unique challenges that call for innovative approaches.As with in any technological assisted medical procedures, accuracy of AR in MIS is paramount. With the use of traditional 2D feature based tracking algorithms such as those used in , 6–8, thIn this Letter, we introduce a novel MIS AR framework that allows accurate overlay of augmented information onto curved surfaces, i.e. accurate annotation and labelling, and tumour measurements along the curved soft tissue surfaces. There are two key features of our proposed framework: (i) real-time computation of robust 3D tracking through a robust feature-based SLAM approach; (ii) an interactive geometry-aware AR environment through incrementally building a geometric mesh via zero mean normalised cross-correlation (ZNCC) stereo matching.2The traditional MIS AR approaches usually employ feature points tracking methods for information overlay. Feature-based 2D tracking methods such as Kanade–Lucas–Tomasi features , 7, scalRecently, SLAM algorithms have led to new approaches to endoscopic camera tracking in MIS. Originally designed for robot navigation in unknown environments, the algorithms can be adapted for tracking the pose of endoscopic cameras while simultaneously building landmark maps inside the patient body during MIS procedures. SLAM-enabled AR systems not only improve the usability of AR in MIS due to no optical or magnetic tracking devices to obstruct the surgeons’ view, but they also offer greater accuracy and robustness compared with traditional feature-based AR systems.Direct-based SLAM algorithms compare pixels  or reconThe first keyframe-based SLAM – PTAM   was a brIn this Letter, we present a novel real-time AR framework that provides 3D geometric information for accurate AR content registration and overlay in MIS. We propose a new approach to achieve robust 3D tracking through a feature-based SLAM for real-time performance and accuracy required for endoscopy camera tracking. To obtain accurate geometric information, we incrementally build a dense 3D point cloud by using ZNCC stereo matching. Therefore, our framework handles the challenging situations of rapid endoscopy movements with robust real-time tracking, while providing an interactive geometry-aware AR environment.3As can be seen from the flowchart in Fig. 3.1In medical interventions, real-time performance and accuracy are both critical. We adopt oriented FAST and rotated BRIEF (ORB)  feature x coordinates on the left and right images, respectively. Assuming the left image and the right image are already rectified, the focal length of both cameras f and the baseline B are known fixed values, by similar triangles, the depth or the perpendicular distance Z between the points and the endoscope can be found according to similar triangles .3.3As our camera pose estimation is only based on the last state, the accumulation of error over time would cause system drifting. However, we cannot perform a global optimisation for every frame as this will slow down the system over time. We follow the successful approach of PTAM  and ORBSOnce a keyframe is assigned, BA is applied to refine the 3D positions of each stored keyframe 3.4We create a feature-based visual odometry system for the endoscopic camera tracking and landmark points mapping, which takes into account of illumination changes, specular reflections and tissue deformations in MIS scenes. However, as the sparse landmark points can barely describe the challenging environment of MIS scenes, we perform a dense stereo matching upon the landmark points to create a dense reconstruction result.p at disparity d is derived by measuring the ZNCC of the pixel in the left image and the corresponding pixel p.The dissimilarity measure used during the stereo matching is a patch-based ZNCC method. The cost value p, followed by a convex optimisation to solve the cost volume constructed by Huber-ZNCC is proven to be less sensitive to illumination changes and can be parallelised efficiently on a graphics processing unit (GPU) . A winnefunction  for a sm3.5a, c and 5a, c).The 3D dense points estimated by stereo matching are transformed to the world coordinate system by the transformation matrix from frame space to the world space n method  is then 4We have designed a two-parts assessment process to evaluate our AR framework: (i) using a realistic 3D simulated MIS scene as the ground truth study to measure the reconstruction error by measuring the difference between the ground truth values and the reconstructed values; (ii) using a real in vivo video acquired from the Hamlyn Centre Laparoscopic/Endoscopic Video Datasets , 30 to a4.1Our system is implemented in an Ubuntu 14.04 environment using C/C++. All experiments are conducted on a workstation equipped with Intel Xeon(R) 2.8 GHz quad core CPU, 32 GB memory and one NVIDIA GeForce GTX 970 graphics card. The size of the simulation image sequences and in vivo endoscope videos is 840 × 640 pixels. The AR framework and 3D surface reconstruction run in different threads. The 3D surface reconstruction process takes about 200 ms to traverse the entire pipeline for each frame. Our proposed AR framework can run in real time at 26 fps when the reconstruction only performs at keyframes.4.2The performance of our proposed framework is measured in terms of reconstruction accuracy by comparing the reconstructed surface with the 3D model used to render the simulation video.To quantitatively evaluate the performance of the progressive reconstruction result, we used Blender  – an opex, y coordinate points based on the surface area, and then compared the distance of the z-value of the two surfacesRoot mean square distance (RMSD) is used to evaluate the overall distance between the simulated and the reconstructed surfaces. By aligning the surfaces to the real-world coordinate system, we apply a grid sample to get a series of 4.3a shows the reconstruction result from our 3D reconstruction framework with the augmented view of in vivo video sequences. By clicking the mesh, augmented objects (coloured planes) can be superimposed at corresponding positions with correct poses based on the normals of the points at the click locations. Fig. 6b shows the side view of the mesh; note that the coloured planes (which could be labels) are sticking onto the mesh correctly to create a realistic augmented environment. Fig. 6c shows the area highlighting function of our proposed AR framework. Fig. 6d is the corresponding mesh view. The area highlighting function can be extended to an area measurement and line measurement (such as shown in Fig. To qualitatively evaluate the performance of our proposed surface reconstruction framework, we applied the proposed approach on in vivo videos that we acquired from Hamlyn Centre Laparoscopic/Endoscopic Video Datasets , 30. Fig65In this Letter, we presented a novel AR framework for MIS. Our framework handles the two intertwined issues of tracking the rapid endoscope camera movements and providing accurate information overlay onto the curved surfaces of organs and tissues. By adapting the latest SLAM algorithms, we take a set of innovative approaches at the each stage of the AR process to improve the computational performances and AR registration accuracy. As a result, an interactive real-time geometric aware AR system has been developed. The system is capable of dealing with small soft tissue deformations, rapid endoscope movement and illumination change, which are common challenges in MIS AR. Our proposed system does not require any prior template or pre-operative scan. The system can overlay accurate augmented information such as annotations, labelling and measurements of a tumour over curved surfaces, greatly improving the quality of AR technology in MIS.In future work, we will carry out a clinical pilot study. A case scenario will be investigated in collaboration with a practicing surgeon, and comparisons will be made as to the effectiveness of our system with the current procedural approach used.6Conflict of interest: none declared.


The morphology and composition of the alloy surfaces were investigated using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The corrosion rate and surface roughness of both alloys increased as the concentration of NaOH in aqueous solution was raised. The presence of some protective elements in the composition of the alloys led to the formation of a spontaneous passive layer on the alloy surface. The higher resistance values of both alloys were associated with the magnitude of the dielectric properties of the passive films formed on their surfaces. Both alloys are classified as having outstanding resistance to corrosion, which results from the formation of a passive film that acts as an efficient barrier to corrosion in alkaline solution.The electrochemical behavior of the oxide layers on two metal-metal glassy alloys, Fe They found that the corrosion resistance of this alloy was better than its structural relaxation/crystallization counterparts. The (Fe44.3Cr5Co5Mo12.8Mn11.2C15.8B5.9)98.5Y1.5 bulk glassy alloy was studied in very basic solution (1.0M NaOH) by Gostin et al. [The glassy alloys are considered to be particuarly interesting metallic materials because of exceptional properties, or combinations of physical and chemical properties, that distinguish metallic glassy alloys from conventional crystalline materials . The for in 1960 . However in 1960 . The fir in 1960  and, sin in 1960 –8. The m in 1960 ,11. Gong in 1960  investign et al. . This alIn this study we explored the effect of NaOH concentration on passivation behaviour of two alloys (VX9 and VX50). Alloy resistivity can be explained according to the composition of the protective film formed in alkaline media, and the properties of these alloys make them very attractive for industrial application.78Co9Cr10Mo2Al1 (VX9) and Fe49Co49V2 (VX50) (at.%) were supplied by Vacuumschmelze GmbH & Co. KG, Hanau, Germany. A surface area of 1 cm2 was used as the working area and each experiment was carried out with fresh sample. The test solution was an aerated solution of sodium hydroxide at different concentrations  at ambient temperature (27°C). The electrochemical measurements were performed on an Interface 1000™ potentiostat/galvanostat . For accurate results, each experiment was repeated at least three times. The experimental data were analyzed using EFM140, EIS300 and DC105 software (Gamry Instruments). The electrochemical cell was comprised of three electrodes: the working electrode (sample), a saturated Ag/AgCl electrode and a platinum counter electrode.Sheets of metal-metal glassy alloys Fe−1. The potential forward sweep was from the cathodic to the anodic direction (−700 to 1200 mV) and the potential reverse sweep was from the anodic to cathodic direction over the same range.The electrochemical frequency modulation (EFM) data were obtained using two frequencies, 2 and 5 Hz, with an amplitude of 10 mV, and the base frequency was 0.1 Hz at the open circuit potential (OCP). The electrochemical impedance spectroscopy (EIS) was conducted with an applied 10 mV sine wave and measurements were recorded over a frequency range of 800 kHz to 0.1 Hz. The cyclic polarization experiments were carried out after the impedance run in different concentrations of NaOH solution  at a scan rate of 1.5 mVsSurface morphological characterization was performed after cutting the specimen at the passive region in the anodic polarization state. The alloy surface was examined by scanning electron microscopy  and atomic force microscopy . Structural characterization was by X-ray photolectron spectroscopy (XPS) on an Axis Ultra DLD  with AlKα at 150 W of X-ray power in alkaline media.2 approximately 10−4–10−6).Nyquist and Bode plots are shown in max, was around 85° (f/s) in NaOH solution at 0.1M and 0.25M (1.12 × 106 and 282.6 × 103 Ωcm2) results from formation of small pores in the passive film consisting of Cr2O3, MoO2 and Al2O3 . As these pores become larger, the passive film becomes more defective. The Rf/s decreased in 0.5M NaOH due to a high dissolution rate of Fe ions on the outer passive film. The passive film formed on the VX50 alloy surface consisted of two layers  grows first. Consequently, the growth of the inner layer (CoO) is influenced by ionic diffusion through the outer layer, such that the thickness of the inner layer gradually increases after growth of the outer layer is completed [f/s) was much higher than the resistance of the inner layer (Rm/f), suggesting that the outer layer was thicker than the inner layer. In general, the reason for the low resistance of the passive film formed on the VX50 alloy surface is the high level of iron compounds . The iron oxides provide less protection of the alloy surface against corrosion because they behave as n-type semiconductors.The maximum phase angle, θound 85° , suggesto layers . This suompleted ,15. The ompleted . The CPE6 Ωcm2) was approximately five-fold (4.93) greater than the resistance of VX50 alloy (227.01 × 103 Ωcm2) in 0.1M NaOH solution. This indicates that the passive film formed on the surface of VX9 alloy was more protective than that formed on the surface of VX50 alloy at low NaOH concentration. In addition, the resistance of the VX9 alloy (88.78 × 103 Ωcm2) was 94.43% of that of the VX50 alloy (94.02 × 103 Ωcm2) in the aggressive 0.5M concentration of NaOH Finally, the resistance of VX9 alloy , the corrosion rates (mmpy) and the Ipass values for both alloys increased as the concentration of the NaOH solution was increased. The porous passivating layer on the VX9 alloy surface in 0.5 M NaOH caused low stability for this layer, giving the highest value of Ipass (19.74 μAcm−2). Evidently, in 0.1M and 0.25M NaOH the passive film behaves as an efficient barrier against corrosion, suggesting healing of the pits. These results from the cyclic polarization measurements are in complete agreement with the EIS measurements.According to the data in c) and the absence of a significant shift in the cathode branch  and corrosion rate (mmpy) for both alloyswere increased as the NaOH concentration increased. The augmentation of the corrosion current density from 0.1M to 0.5M NaOH was about 3.36 times for VX9 alloy and 1.17 times for VX50 alloy. These data are in good agreement with those obtained from the DC and AC methods. The causality factors values, CF2 and CF3, suggest that the data obtained by this technique are reliable.The results indicate that the corrosion current density  on the surface [ox2p3/2 corresponded to Cr2O3 and Cr(OH)3, respectively, on the surface of the VX9 alloy. These chromium compounds indicate high resistance of the passive film [m 3d5/2 and Moox 3d3/2 situated at 228 and 231 eV, indicating the presence of the metallic species, Mo and MoO2, respectively [ox 2p spectrum  in the passive layer [3/2 spectrum (3O4 and Co(OH)2, respectively, on the VX50 alloy surface, of which Co3O4 is considered to be very effective in passive films [ox 1s spectrum at 530 eV illustrated the presence of O2− ion or an M–O bond, and the peak at 531 eV is due to OH−. These peaks can be attributed to the formation of oxide or hydroxide components, respectively.The peak corresponding to Fet 711 eV  relates ve layer ,19. The spectrum , locatedve films ,19. The s/f) at 0.5M  before and after exposure to NaOH solution (0.1M–0.5M) is shown in  at 0.5M .The thickness of the passive layer on the VX50 alloy surface also decreased as the concentration of the NaOH solution increased. This thinning was accompanied by the appearance of defects in 0.5M NaOH, as shown in The surfaces of the VX9 and VX50 alloys were examined by AFM after exposure to NaOH solution to determine the surface roughness at different concentrations  as shown in a) of VX9 and VX50 alloys surfaces was directly proportional to the NaOH concentration and increased about 2.32-fold for VX9 alloy and 1.72-fold for VX50 alloy between 0.1M and 0.5M NaOH. The data in t) of VX9 alloy was less than that of VX50 alloy, (b) the valley depth (Rv) on the surface of the VX50 alloy was greater than that on the VX9 alloy; at high concentration (0.5M) (c) it was evident that the highest peak (Rp) was recorded on the VX9 alloy surface, (d) the deepest valley was observed on the surface of the VX9 alloy . This indicates that the VX9 alloy surface was significantly affected at the high concentration of NaOH. These results are in agreement with the electrochemical measurements.The AFM parameters are summarized in 78Co9Cr10Mo2Al1 and Fe49Co49V2 glassy alloys was investigated in NaOH solution . As the concentration of NaOH was increased, theresistance of both alloys decreased and the corrosion rate increased. Consequently, the roughness of the VX9 and VX50 alloy surfaces was directly proportional to the concentration of NaOH in solution, in line with the decreased resistance. The passive film formed on the VX50 alloy surface was a sandwich-type of cobalt oxide films consisting of an inner CoO layer and an outer Co3O4 layer. The resistivity of the two alloys was associated with the magnitude of the dielectric properties of the passive films formed on their surface.The passivation behavior of FeS1 Table(TIF)Click here for additional data file.S2 Table(TIF)Click here for additional data file.S3 Table(TIF)Click here for additional data file.


PACS number(s): 01.60.+q Dr. Jimmy Fenn, Professor Emeritus in Radiation Oncology, Medical University of South Carolina, Charleston, South Carolina, passed away on September 28, 2000 at the age of 62. He died of complications arising from pneumonia. Jimmy was a Fellow of the American Association of Physicists in Medicine (AAPM), the American College of Medical Physics (ACMP), and the American College of Radiology (ACR). Jimmy's career in medical physics spanned nearly four decades. Much of that time was spent at the Medical University of South Carolina where he served as the head of radiation oncology physics from the early 1980's to his recent retirement in 1998.Jimmy received his bachelor's degree in physics in 1965 from Lincoln Memorial University in Tennessee and began his career in medical physics shortly thereafter as a radiation physicist in the Department of Radiology at Emory University School of Medicine. During that time he also continued his graduate studies at Emory University, receiving his master's degree in radiological physics in 1967. He continued his graduate studies interspersed with his medical physics career and in 1980 he received his doctoral degree in physics from the Georgia Institute of Technology.In 1977, Jimmy was certified in Radiological Physics by the American Board of Radiology (ABR), and in 1990 he was certified in Radiation Oncology Physics by the American Board of Medical Physics (ABMP). Jimmy's efforts in supporting board certification for medical physicists are well known. He never wavered in his belief of the importance of board certification and gave unselfishly of his time serving both the ABR and the ABMP.Jimmy was a highly respected clinical medical physicist. He held several leadership positions in medical physics serving as President of the Southeastern Chapter of the AAPM in 1972, and as an elected member of the AAPM Board of Directors from 1985 to 1988. He also gave unselfishly of his time serving on many AAPM committees and councils including the Professional Council and the Science Council. Jimmy was also very active in the ACMP, being elected to the Board of Chancellors in 1982–83. During that time, he was elected as Secretary for the ACMP. Over the next decade he continued his strong support in promoting ACMP's efforts regarding medical physics professional issues, and in 1991 was elected Chairman of the Board of Chancellors. In addition, he was also active in the ACR serving on the Radiation Physics Committee in the ACR Commission on Radiation Therapy during the years 1981 to 1988.Throughout his career, Jimmy was strongly committed to the teaching of physician residents in radiology and radiation oncology, dosimetrists, and the mentoring of young physicists entering the field of medical physics. One of his greatest strengths was his ability to communicate effectively with trainees and shed light on even the most complicated subjects by using straightforward, clinically relevant examples.Jimmy's untiring efforts and contributions to medical physics were recognized by his peers and radiation oncology colleagues as evidenced by his previously mentioned selection to Fellow status in all three organizations, AAPM, ACMP, and ACR. In 1999, Jimmy received the ACMP Marvin M.D. Williams Professional Achievement Award, its highest honor, recognizing his many contributions to the field.For all of Jimmy Fenn's medical physics accomplishments, those of us who knew him well know that his real passion for living stemmed from his relationships with people and his love of the outdoors, particularly fishing. He leaves behind his beloved wife, Debbie, his two stepsons, Vincent and Cole, his son, Daniel and two daughters, Nancy Anne and Beth, his close friends in Charleston, and his many friends throughout the world. His efforts in promoting the profession of medical physics are well known, and will be long remembered. Equally well known is the way he conducted himself throughout his career, always being a man of high principle and always a true gentleman. He truly was a credit to our profession. He will be greatly missed.


AURKA is an AR-V target gene demonstrating a positive feedback mechanism of androgenic signalling in CRPC. In all, our data suggests that Aurora A plays a pivotal role in regulation of AR-V7 expression and represents a new therapeutic target in CRPC.Androgen receptor variants (AR-Vs) provide a mechanism of therapy evasion in castrate-resistant prostate cancer (CRPC), yet mechanisms of regulation remain largely unknown. Here we investigate the role of Aurora A kinase on AR-Vs in models of CRPC and show depletion of Aurora A reduces AR-V target gene expression. Importantly, knockdown of Aurora A reconfigures splicing of AR pre-mRNA to discriminately down-regulate synthesis of AR-V transcripts, including AR-V7, without effecting full-length AR mRNA; and as a consequence, AR-V-driven proliferation and survival of CRPC cells is markedly reduced. Critically, these effects are reproduced by Aurora A inhibition. We show that Aurora A levels increase in advanced disease and  Prostate cancer (PC) is the most frequently diagnosed cancer in men in the Western world and is the second leading cause of male-related cancer deaths. Current therapeutic strategies exploit the androgen-dependency of tumour growth by inactivating the androgen receptor (AR) with anti-androgens and androgen-deprivation therapies (ADT)145The transcriptional activity of the AR is tightly regulated by a plethora of co-regulatory proteins which control the response to androgenic stimulation by a number of mechanisms, including post translational modificationsAR gene amplification13A number of aberrations to AR signalling have been characterised as mechanisms of resistance to first line ADT including v1 cells by alternate splicing mechanisms which subsequently reduces AR-V target gene transcription including TMPRSS2 and UBE2C. Moreover, depletion of Aurora A reduces cell growth and survival by attenuating AR-dependent cell proliferation. Consistent with a role of Aurora A kinase activity in AR-V regulation, small molecule inhibition of Aurora A reduces AR-V levels, AR-V target gene expression and cell proliferation. In all, our data suggests multiple non-mitotic roles for Aurora A in PC progression and resistance to first-line therapies, and therefore may represent a viable therapeutic target in the treatment of advanced disease.How these AR-Vs are regulated remains largely understudied; particularly their dependency on co-regulatory proteins. In this study, we show that Aurora A depletion discriminately reduces AR-V levels in CWR22RAR exon 1-targeting siRNA (siARex1)  have been identified to confer resistance to current AR-targeting therapies. The clinically-relevant AR-V, AR-V7, has previously been shown to be constitutively associated with chromatin in CWR22Rv1 cells and promotes cell proliferation in castrate conditionssiARex1)  signific control . Importapression . CriticaAURKA gene product) has been previously shown to modulate full-length AR activity and thus represents a potential mechanism of positive feedback that may enhance AR signalling. Although Aurora A kinase expression has been shown to be increased in prostatic intraepithelial neoplasia lesions and localised hormone naïve prostate tumours compared to non-neoplastic samplesAURKA expression in benign prostate tissue, localised PC and metastatic CRPC was assessed. We observed a significant increase in AURKA expression in CRPC (n = 35) compared to primary localised PC (n = 59) and benign (n = 28) samples  with a significant increase between benign and localise PC samples (p = 0.0130)   suggesticis-regulatory elements of target genes and enhance transcriptionPSA, TMPRSS2, UBE2C and CCNA2TMPRSS2, UBE2C and CCNA2 were robustly down-regulated in the presence of DHT and enzalutamide supporting the concept that Aurora A is important for the activity of FL and splice variant forms of the receptor , specific to AR-V7, flanked by canonical exons 3 and 4 and their adjoining intronic sequences  is one of a limited number of proteins that has previously been shown to modulate splicing of AR pre-mRNA and is required for the inclusion of exon Ce3v1  suggestiPSA and TMPRSS2, but failed to impact on CCNA2  of the AR is highly unstructured creating a multitude of binding surfaces for important protein interactions17The AR remains a prominent target for development of novel therapeutic agents in CRPC. It has become apparent that although initially efficacious, anti-hormonal treatments select heterogeneous cell populations that utilise aberrant androgenic signalling to enable therapeutic resistance and disease progressionAurora A gene is directly regulated by AR-V-mediated signalling in CWR22Rv1 cells indicating the existence of a positive-feedback mechanism to amplify aberrant receptor function in advanced disease  supplemented with 10% (v/v) foetal bovine serum (Sigma Aldrich) and 2 mM L-glutamine (Sigma Aldrich) at 37 °C. For steroid-depleted conditions, cells were grown in RPMI-1640 supplemented with 10% (v/v) dextran-coated charcoal-stripped foetal bovine serum (HyClone) and 2 mM L-glutamine. Transient siRNA transfections were carried out using siRNA sequences outlined in v1 cells grown in steroid-depleted conditions with 72 hour knockdown of Aurora A as described in ref. PSA, TMPRSS2 and UBE2C androgen response enhancer regions  for 8 hours before re-transfection with Aurora A targeting siRNA or Scr control and cultured for an additional further 48 hours. Cells were harvested, RNA extracted and resultant cDNA subjected to qPCR as described using specific FL-AR and AR-V7 primers .v1 cells were transfected with siRNA on 90-mm dishes for 48 hours before re-seeding at a density of 200 cells/well of a 6-well plate. Cells were allowed to adhere and were cultured for 12 days with replenishment of media every 3–4 days. Cells were fixed using fixative solution (acetic acid: methanol 3:1) and stained with crystal violet. Presented data represents the average of three independent experiments where colonies were counted and normalised as a percentage of the siScr experimental arm. Propidium iodide staining was used to measure percentage of cells in distinct cell cycle phases by flow cytometry. siRNA transfected CWR22Rv1 cells were cultured for 72 hours in steroid-depleted conditions prior to cell preparation, as described in ref. Cell growth was measured using the IncucyteZoom live cell imager (Essen Bioscience) as a measurement of % confluency. CWR22Rv1 cells were grown in steroid-depleted conditions −/+ DHT (10 nM) or enzalutamide (10 μM) following Scr control or Aurora A targeting siRNA transfections. Images were collected from multiple fields every 6 hours over a 96 hour period and % confluence data analysed. Cell confluence was normalised for time point 0 and presented as relative fold change to the siScr experimental arm. Data represents at least three independent experiments −/+ SEM. For colony forming assays, CWR22RHow to cite this article: Jones, D. et al. Aurora A regulates expression of AR-V7 in models of castrate resistant prostate cancer. Sci. Rep.7, 40957; doi: 10.1038/srep40957 (2017).Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.