Wikipedia - Benutzerbeiträge [de]

Pythium

2017-10-05T22:25:27Z

Sbmehta: capitalization

{{For|the ancient city named Pythium|Pythion}}
{{automatic Taxobox
|image=Pythium (257 23).jpg
|image_alt=Negative phase contrast image of Pythium sp.
|image_caption=Negative [[Phase-contrast microscopy|phase contrast]] image of ''Pythium'' sp.
|taxon=Pythium
|authority=[[Nathanael Pringsheim|Pringsheim]], 1858
|subdivision_ranks=Species
|subdivision=''See text''
}}
'''''Pythium''''' is a [[genus]] of [[parasitism|parasitic]] [[Oomycete|oomycotes]]. They were formerly classified as [[fungus|fungi]]. Most species are [[plant]] [[parasitism|parasites]], but ''[[Pythium insidiosum]]'' is an important [[pathogen]] of [[animal]]s, causing [[pythiosis]]. The feet of the [[fungus gnat]] are frequently a vector for their transmission.<ref>{{Cite web | title=Ecogrow Fungus Gnat | url=http://www.ecogrow.com.au/top10/Fungus_Gnat.html | date=17 March 2014}}</ref>

==Morphology==
;Hyphae: ''Pythium'' species, like others in the family [[Pythiaceae]], are usually characterized by their production of [[coenocyte|coenocytic]] [[hypha]]e without [[septum|septations]].
;Oogonia: Generally contain a single [[oospore]].
;Antheridia: Contain an elongated and club-shaped [[antheridium]].

==Ecological importance==
[[File:Pythium (248 24).jpg|thumb|''Pythium'']]
''Pythium''-induced [[root rot]] is a common crop disease. When the organism kills newly emerged or emerging seedlings, it is known as [[damping off]], and is a very common problem in fields and greenhouses.<ref name="Jarvis">{{Cite book|author=Jarvis, W. R. |title=Managing diseases in greenhouse crops |publisher=APS Press |location=[[Saint Paul, Minnesota]] |year=1992 |pages= |isbn=978-0-89054-122-7}}{{Page needed|date=September 2010}}</ref> This disease complex usually involves other pathogens such as ''[[Phytophthora]]'' and ''[[Rhizoctonia solani|Rhizoctonia]]''. Pythium wilt is caused by [[zoospore]] infection of older plants, leading to biotrophic infections that become necrotrophic in response to colonization/reinfection pressures or environmental stress,<ref name="Jarvis"/><ref name="OG2005">{{Cite book|first=Tony Nathaniel |last=Owen-Going |year=2005 |title=Quantitative investigations of phenolic compounds associated with root rot of hydroponic pepper, Capsicum annuum L., caused by Pythium aphanidermatum (Edson) Fitzp |type=PhD thesis |publisher=[[University of Guelph]] |isbn=978-0-494-17779-2 |oclc=271429383}}{{Page needed|date=September 2010}}</ref><ref name="OG2009">{{Cite journal|doi=10.1080/07060661.2008.10540537|author1=T. N. Owen-Going |author2=C. W. Beninger |author3=J. C. Sutton |author4=J. C. Hall |last-author-amp=yes |year=2008 |title=Accumulation of phenolic compounds in plants and nutrient solution of hydroponic peppers inoculated with ''Pythium aphanidermatum'' |journal=Canadian Journal of Plant Pathology |volume=30 |pages=214–225 |issue=2}}</ref> leading to minor or severe wilting caused by impeded root functioning.<ref name="Jarvis"/><ref name="Bagnall">{{Cite book|first=Roger |last=Bagnall |year=2007 |title=Control of Pythium wilt and root rot of hydroponically grown lettuce by means of chemical treatment of the nutrient solution |type=MSc thesis |publisher=[[University of Pretoria]] |oclc=216915405}}{{Page needed|date=September 2010}}</ref>

Many ''Pythium'' species, along with their close relatives ''[[Phytophthora]]'', are [[plant pathology|plant pathogens]] of economic importance in agriculture. ''Pythium'' spp. tend to be very generalistic and unspecific in their large range of hosts,<ref name="OG2002">{{Cite book|first=Tony Nathaniel |last=Owen-Going |year=2002 |title=Etiology and epidemiology of Pythium root rot in bell pepper (Capsicum annuum L.) in commercial-scale and small-scale hydroponic systems |type=MSc thesis |publisher=[[University of Guelph]] |isbn=978-0-612-71820-3 |oclc=55510696}}</ref> while ''Phytophthora'' spp. are generally more host-specific.

For this reason, ''Pythium'' spp. are more devastating in the [[root rot]] they cause in crops, because [[crop rotation]] alone often does not eradicate the pathogen (nor does [[crop rotation]], as ''Pythium'' spp. are also good [[saprotrophic nutrition|saprotrophs]], and survive for a long time on decaying plant matter).

In field crops, damage by ''Pythium'' spp. is often limited to the area affected, as the motile zoospores require ample surface water to travel long distances. Additionally, the capillaries formed by soil particles act as a natural filter and effectively trap many zoospores. However, in [[hydroponics|hydroponic systems]] inside [[greenhouse]]s, where extensive [[monoculture]]s of plants are maintained in plant nutrient solution (containing [[nitrogen]], [[potassium]], [[phosphate]], and [[micronutrient]]s) that is continuously [[wikt:circulation|recirculated]] to the crop, ''Pythium'' spp. cause extensive and devastating root rot and is often difficult to prevent or control.<ref name="Jarvis"/><ref name="Bagnall"/><ref name="OG2002"/><ref name="OG2003"/> The root rot affects entire operations (tens of thousands of plants, in many instances) within two to four days due to the inherent nature of hydroponic systems where roots are nakedly exposed to the water medium, in which the zoospores can move freely.<ref name="Bagnall"/><ref name="OG2002"/><ref name="OG2003">{{Cite journal|doi=10.1080/07060660309507064|author=T. N. Owen-Going, J. C. Sutton & B. Grodzinski |year=2003 |title=Relationships of ''Pythium'' isolates and sweet pepper plants in single-plant hydroponic units |journal=Canadian Journal of Plant Pathology |volume=25 |pages=155–167|issue=2}}</ref>

Several ''Pythium'' species, including ''[[Pythium oligandrum|P. oligandrum]]'', ''[[Pythium nunn|P. nunn]]'', ''[[Pythium periplocum|P. periplocum]]'', and ''[[Pythium acanthicum|P. acanthicum]]'', are [[Fungus#As_targets_of_mycoparasites|mycoparasites]] of plant pathogenic fungi and oomycetes, and have received interest as potential [[Biological pest control|biocontrol]] agents.

==Species==
{{div col|colwidth=250px}}
*''[[Pythium acanthicum]]''
*''[[Pythium acanthophoron]]''
*''[[Pythium acrogynum]]''
*''[[Pythium adhaerens]]''
*''[[Pythium amasculinum]]''
*''[[Pythium anandrum]]''
*''[[Pythium angustatum]]''
*''[[Pythium aphanidermatum]]''
*''[[Pythium apleroticum]]''
*''[[Pythium aquatile]]''
*''[[Pythium aristosporum]]''
*''[[Pythium arrhenomanes]]''
*''[[Pythium attrantheridium]]''
*''[[Pythium bifurcatum]]''
*''[[Pythium boreale]]''
*''[[Pythium buismaniae]]''
*''[[Pythium butleri]]''
*''[[Pythium camurandrum]]''
*''[[Pythium campanulatum]]''
*''[[Pythium canariense]]''
*''[[Pythium capillosum]]''
*''[[Pythium carbonicum]]''
*''[[Pythium carolinianum]]''
*''[[Pythium catenulatum]]''
*''[[Pythium chamaehyphon]]''
*''[[Pythium chondricola]]''
*''[[Pythium citrinum]]''
*''[[Pythium coloratum]]''
*''[[Pythium conidiophorum]]''
*''[[Pythium contiguanum]]''
*''[[Pythium cryptoirregulare]]''
*''[[Pythium cucurbitacearum]]''
*''[[Pythium cylindrosporum]]''
*''[[Pythium cystogenes]]''
*''[[Pythium debaryanum]]''
*''[[Pythium deliense]]''
*''[[Pythium destruens]]''
*''[[Pythium diclinum]]''
*''[[Pythium dimorphum]]''
*''[[Pythium dissimile]]''
*''[[Pythium dissotocum]]''
*''[[Pythium echinulatum]]''
*''[[Pythium emineosum]]''
*''[[Pythium erinaceum]]''
*''[[Pythium flevoense]]''
*''[[Pythium folliculosum]]''
*''[[Pythium glomeratum]]''
*''[[Pythium graminicola]]''
*''[[Pythium grandisporangium]]''
*''[[Pythium guiyangense]]''
*''[[Pythium helicandrum]]''
*''[[Pythium helicoides]]''
*''[[Pythium heterothallicum]]''
*''[[Pythium hydnosporum]]''
*''[[Pythium hypogynum]]''
*''[[Pythium indigoferae]]''
*''[[Pythium inflatum]]''
*''[[Pythium insidiosum]]''
*''[[Pythium intermedium]]''
*''[[Pythium irregulare]]''
*''[[Pythium iwayamae]]''
*''[[Pythium jasmonium]]''
*''[[Pythium kunmingense]]''
*''[[Pythium litorale]]''
*''[[Pythium longandrum]]''
*''[[Pythium longisporangium]]''
*''[[Pythium lutarium]]''
*''[[Pythium macrosporum]]''
*''[[Pythium mamillatum]]''
*''[[Pythium marinum]]''
*''[[Pythium marsipium]]''
*''[[Pythium mastophorum]]''
*''[[Pythium megacarpum]]''
*''[[Pythium middletonii]]''
*''[[Pythium minus]]''
*''[[Pythium monospermum]]''
*''[[Pythium montanum]]''
*''[[Pythium multisporum]]''
*''[[Pythium myriotylum]]''
*''[[Pythium nagaii]]''
*''[[Pythium nodosum]]''
*''[[Pythium nunn]]''
*''[[Pythium oedochilum]]''
*''[[Pythium okanoganense]]''
*''[[Pythium oligandrum]]''
*''[[Pythium oopapillum]]''
*''[[Pythium ornacarpum]]''
*''[[Pythium orthogonon]]''
*''[[Pythium ostracodes]]''
*''[[Pythium pachycaule]]''
*''[[Pythium pachycaule]]''
*''[[Pythium paddicum]]''
*''[[Pythium paroecandrum]]''
*''[[Pythium parvum]]''
*''[[Pythium pectinolyticum]]''
*''[[Pythium periilum]]''
*''[[Pythium periplocum]]''
*''[[Pythium perniciosum]]''
*''[[Pythium perplexum]]''
*''[[Pythium phragmitis]]''
*''[[Pythium pleroticum]]''
*''[[Pythium plurisporium]]''
*''[[Pythium polare]]''
*''[[Pythium polymastum]]''
*''[[Pythium porphyrae]]''
*''[[Pythium prolatum]]''
*''[[Pythium proliferatum]]''
*''[[Pythium pulchrum]]''
*''[[Pythium pyrilobum]]''
*''[[Pythium quercum]]''
*''[[Pythium radiosum]]''
*''[[Pythium ramificatum]]''
*''[[Pythium regulare]]''
*''[[Pythium rhizo-oryzae]]''
*''[[Pythium rhizosaccharum]]''
*''[[Pythium rostratifingens]]''
*''[[Pythium rostratum]]''
*''[[Pythium salpingophorum]]''
*''[[Pythium scleroteichum]]''
*''[[Pythium segnitium]]''
*''[[Pythium spiculum]]''
*''[[Pythium spinosum]]''
*''[[Pythium splendens]]''
*''[[Pythium sterilum]]''
*''[[Pythium stipitatum]]''
*''[[Pythium sulcatum]]''
*''[[Pythium terrestris]]''
*''[[Pythium torulosum]]''
*''[[Pythium tracheiphilum]]''
*''[[Pythium ultimum]]''
**[[Pythium ultimum var. ultimum|''Pythium ultimum'' var. ''ultimum'']]
*''[[Pythium uncinulatum]]''
*''[[Pythium undulatum]]''
*''[[Pythium vanterpoolii]]''
*''[[Pythium viniferum]]''
*''[[Pythium violae]]''
*''[[Pythium volutum]]''
*''[[Pythium zingiberis]]''
*''[[Pythium zingiberum]]''
{{div col end}}

''[[Globisporangium sylvaticum]]'' was formerly placed here as ''Pythium sylvaticum''

== See also ==
{{commons category|Pythium}}
*{{wikispecies-inline|Pythium|''Pythium''}}
*[[Pythium in turfgrass]]

== References ==
{{Reflist|2}}

== Further reading ==
*{{Cite journal|author=A. J. van der Plaats-Niterink |year=1981 |title=Monograph of the genus ''Pythium'' |journal=[[Studies in Mycology]] |volume=21 |pages=1–242}}
*{{Cite journal|author=C. André Lévesque & Arthur W. M. de Cock |year=2004 |title=Molecular phylogeny and taxonomy of the genus ''Pythium'' |journal=[[Fungal Biology|Mycological Research]] |volume=108 |issue=12 |pages=1363–1383 |doi=10.1017/S0953756204001431}}

{{taxonbar}}

[[Category:Water mould plant pathogens and diseases]]
[[Category:Pythium| ]]

Hydraulophon

2009-12-25T09:34:36Z

Sbmehta: capitalization

{{Infobox Instrument
|name=Hydraulophone
|names=Woodwater instrument
|image=HHSB playing Suite for Hydraulophone.jpg
|image_capt=[[Hydraulist]] and [[composer]] [[Ryan Janzen]], playing with [[Hart House Symphonic Band]].
|background=other
|classification=
*[[Water instrument|Water]]
*[[Woodwater instrument|Woodwater]]
*[[Reedless wind instrument|Reedless]]
*[[Single-reed instrument|Single-reed]]
*[[Double reed|Double-reed]]
|hornbostel_sachs=NaN
|hornbostel_sachs_desc=Hydraulophone
|range=Basic range of a diatonic hydraulophone with 12 water jets: [[File:Hydraulophone diatonic rangeWithoutOctave.svg|200px|center]] 
More detailed ranges and compasses appear below.
|related=
*[[Flute]]
*[[Glass harmonica]]
*[[Pipe organ]]
|musicians=
*[[Hydraulist]]s
|articles=
}}

[[Image:Hydraulophone45jets091.jpg|thumb|200px|Waterflute (reedless) hydraulophone with 45 finger-embouchure holes, allowing an intricate but polyphonic embouchure-like control by inserting one finger into each of several of the instrument's 45 mouths at the same time.]]

A '''hydraulophone''' is a tonal acoustic musical instrument that is played by direct physical contact with hydraulic fluid (usually water) in which sound is generated or affected hydraulically<ref name=watershapes>"Fluid Melodies: The hydraulophones of Professor Steve Mann" In WaterShapes, Volume 10, Number 2, Pp36-44, New York, NY, USA</ref><ref name=absement>Mann, S. Hydraulophone design considerations: absement, displacement, and velocity-sensitive music keyboard in which each key is a water jet, International Multimedia Conference archive, Proceedings of 14th annual ACM international conference on Multimedia, Pp 519-528, Santa Barbara, CA, USA</ref>. Typically the sound is produced by the same hydraulic fluid that is in direct contact with the player's fingers<ref>Mann, S. flUId Streams: Fountains that are keyboards with nozzle spray as keys..., Proceedings of ACM Multimedia 2005, Pp. 181-190, Singapore</ref>. The term has also been used to refer to an acoustic sound-producing mechanism that is used as an interface or input device involving the monitoring of fluid flow. Examples include hydraulophones for fluid-flow monitoring and measurement applications, such as building automation, equipment monitoring, and the like (e.g. determining which faucet or toilet in a building is operating and how much water it is consuming)<ref name=listening>Janzen, R. and Mann, S. Arrays of water jets as user interfaces: Detection and estimation of flow by listening to turbulence signatures using hydrophones. Proceedings of the 15th International Conference on Multimedia, Pp. 505-508, Augsburg, Germany, 2007</ref>. The hydraulophone in the first sense was invented and named by Professor [[Steve Mann]].

==Types of hydraulophone and basic operation==
This article concerns itself with hydraulophones that are musical instruments, or sound sculptures.

The term may be applied based on the interface used to play the instrument, in which a player blocks the flow of water through a particular hole in order to sound a particular note, or based on a hydraulic sound production mechanism. Hydraulophones work using various sound production mechanisms involving water flow, and what they share in common is the user-interface (blocking water jets to produce sound). Those described in <ref name=absement>Mann Design</ref> use water jets striking perforated spinning disks, shafts, or valves, to create a pulsating water flow, similar to a [[siren disk]]. A single disk, shaft, or valve assembly can have rings or passages with different numbers of holes for different notes. Some hydraulophones have reeds (one or more reed for each finger hole) and some are reedless, having one or more [[fipple]] mechanism <ref name=absement>Mann Design</ref> associated with each finger hole, thus having no moving parts to wear out.

Blocking flow through a fingerhole directs the water instead to one or more of the above-described sound-production mechanisms, or resulting changes in flow or pressure affect a separate sounding mechanism associated with each finger hole<ref name=absement>Mann Design</ref>.

Some hydraulophones include an underwater hydrophone pickup to allow the sounds produced by the water to be electrically amplified, whereas others do not use electric amplification. The use of electric amplification also allows various effects to be added, as with an electric guitar, as well as the possibility of making the hydraulophone function as a hyper-acoustic instrument (i.e. using computation to change the acoustic sound of the water into some other instrument)<ref name=electric>The Electric Hydraulophone: An acoustic hyperinstrument with feedback, International Computer Music Conference, Pp. 162, Copenhagen, Denmark</ref>.

==Relationship to woodwind instruments==
The hydraulophone is similar to a woodwind instrument, but it runs on incompressible (or less compressible) fluid rather than a compressible gas like air. In this context hydraulophones are sometimes called "woodwater" instruments regardless of whether or not they are made of wood (as woodwind instruments are also often not made of wood).

===Hydraulophone embouchure===
Since humans do not breathe water, the water must be "blown" into the hydraulophone by way of a pump which can be hand-operated, wind operated, water powered, or electric. Unlike woodwind instruments in which there is one mouthpiece at the entrance to the flute chamber, hydraulophones have mouthpieces at every exit port from the chamber.

Whereas [[fipple flute|internal ducted flutes]] have one [[fipple]] mechanism for the mouth of the player, along with several finger holes that share the one fipple mechanism, the hydraulophone has a separate mouth/mouthpiece for each finger hole. A typical park-hydraulophone for installation in public spaces has 12 mouths, whereas a concert hydraulophone typically has 45 mouths.

[[Embouchure]] is controlled by way of the instrument's mouths, not the player's mouth such that the player can sing along with the hydraulophone (i.e. a player can sing and play the instrument at the same time). Moreover, the instrument provides the unique capability of polyphonic embouchure, where a player can dynamically "sculpt" each note by the shape and position of each finger inserted into each of the mouths. For example, the sound is different when fingering the center of a water jet than when fingering the water jet near the periphery of the circular mouth's opening.

==12-jet diatonic hydraulophones==
Many [[diatonic]] hydraulophones are built with 12 water jets, one for each of the 12 notes.
The standard compass starts on A, extending up an octave and a half to E. We say 1 1/2 octaves in the sense that the high E has a frequency that is (2 * 1.5 = 3) times as large as that of the low A, ie. an octave (8va) plus a perfect fifth (P5) higher.

[[Image:Hydraulophone diatonic range.png|thumb|left|400px|Extended playing ranges for a [[diatonic]] 12-water-jet hydraulophone]]
The standard A to E range, in which it is possible to play with [[polyphonic embouchure]] on any or all diatonic notes at the same time, is shown on the left side of the diagram. When playing only [[monophonic]]ally, some additional range is possible on certain hydraulophones, indicated here by small cue notes at the end-points.

Left, the extended notes come from closing key change valves or flexing key change levers, for sharpener, and flattener. To play a low G, one must be playing in C minor (with Ab) and close the flattener valve simultaneously. When playing on the high E jet, closing the sharpener valve produces an F.

With change-valves, the diatonic hydraulophone is polyphonic in the same sense as a so-called "chromatic harmonica" --- you can play chords and move all members of a chord down one semitone or up one semitone together, but the function of the valves is usually not separated to work on a per-note basis, so for example, you can play an A-minor chord, and flex the entire chord down to A-flat minor, but you can't easily play an A major chord without the use of polyphonic embouchure to bend only the middle note to a C# (which requires more skill than the average hydraulist has). Thus the "diatonic" hydraulophone is called "diatonic" conservatively to "under promise and over-deliver".

Finally, on the right, the additional extended range comes from the two octave-change valves (all notes can be shifted as many as two octaves down, or one octave up).

==45-jet chromatic hydraulophones (concert hydraulophones)==
[[Image:Hydraulophone 45jet range.svg|thumb|right|250px|Playing range of a 45-jet hydraulophone]]
Whereas park and pool hydraulophones are usually 12-jet diatonic, concert-hydraulophones are usually 45-jet chromatic.

45-jet hydraulophones have a 3 1/2 octave range of A to E, [[chromatic]], plus an additional A-flat below the lowest A.
The playing compass (45 water jets) is the same as the sounding range (45 notes).

Usually only 12-jet hydraulophones are installed in public spaces, but the rare exception is the 45-jet south hydraulophone at the [[Ontario Science Centre]] which is a concert-hydraulophone having this precise range/compass. It
is available to any member of the public, for use, free of any admission fees or other cost, and it runs 24 hours a day.

==Relationship to other musical instruments in the orchestra==
[[Image:Musical instrument classification by physics-based organology.png|thumb|400px|left|Musical instrument classification by physics-based organology]]

The hydraulophone does not fit into any standard musical instrument classifications scheme that was in existence before the invention of the hydraulophone. In order to try to relate the Hydraulophone to other instruments, a physics-based organology has been introduced, subsequent to the invention of the hydraulophone. In this scheme, the top-level category of classification is the state-of-matter of that which initially produces the sound in the instrument.<ref name=physiphones>Natural Interfaces for Musical Expression: Physiphones and a physics-based organology, in Proceedings of the 2007 Conference on New Interfaces for Musical Expression (NIME07), Pages 118-123, New York, NY, USA</ref>

The first three-categories of the Hornbostel Sachs system fall under the first category of the physical organology system, as they all produce sound from matter in its solid state.

This physical organology is as follows:
*1 Gaiaphones (Earth/Solid), instruments in which the initial sound-production medium is by matter in its solid-state, e.g. the piano.
**1.1 Chordophones: sound produced by solids that are essentially 1-dimensional (having a cross-section much smaller than their length, i.e. strings), e.g. violin, guitar, electric guitar, electric bass, etc.;
**1.2 Membranophones: sound produced by solids that are essentially 2-dimensional (much thinner than their surface area) membranes, e.g. drums;
**1.3 Idiophones: sound produced by bulk 3-dimensional solid matter, e.g. '''[[crystallophone]]''', '''[[glass harmonica]]''', xylophone, metallophone, etc., regardless of whether the instrument is operated underwater or in air;
*2 Hydraulophones (Water/Liquid): sound produced by matter in its liquid state; instrument itself may be played underwater or played in a surrounding medium of air, with water supplied only to the internal workings of the instrument:
**2.0 Waterflutes (reedless hydraulophones);
**2.1 Single-reed hydraulophones (typically having 1 reed for each finger hole);
**2.2 Double-reed hydraulophones (typically having 2 reeds for each finger hole);
**2.3 Polyreed hydraulophones (typically having 3 or more reeds for each finger hole);
*3 Aerophones (Air/Gas): sound produced by matter in its gaseous state, e.g. woodwind instruments and brass instruments;
*4 [[Plasmaphones]]/Ionophones (Fire/Plasma): sound produced by matter in a high-energy state such as plasma, e.g. plasmaphone, etc.;
*5 Quintephones (Quintessence/Idea): sound produced informatically, by electrical, optical, mechanical, or other computational/algorithmic means.<ref name=physiphones>Natural Interfaces for Musical Expression: Physiphones and a physics-based organology, in Proceedings of the 2007 Conference on New Interfaces for Musical Expression (NIME07), Pages 118-123, New York, NY, USA</ref>

===Classifications based on surrounding media===
[[Image:Musical instruments in 3 states of matter immersed in water.jpg|300px|thumb|Solid, Liquid, and Gas (left-to-right) instruments, all three immersed in Liquid. The immersional (surrounding) media does not dictate the primary top-level musical instrument classification, although it greatly changes the sound (i.e. dampens the guitar without changing the fact it is a chordophone, and silences the recorder).]]

At the [[International Computer Music Conference]] in 2007, the conference theme was '''Immersed Music''' and featured some immersed performances and concerts. This raised some important questions regarding the role of the surrounding medium (air or water) in which a musical instrument is played, as well as the role of water in other non-hydraulophonic instruments.

For example, Benjamin Franklin's glass (h)armonica remains a friction idiophone regardless of the fact that it is played by wet fingers. A version of the [[armonica]] designed to be played underwater was recently created. This version is still a friction idiophone, not a hydraulophone.

Likewise, arrays of drinking glasses tuned with water are still idiophones, as the water is not what produces the initial sound, but is merely a tuning element.

===Relationship between hydraulophone and the "strings, percussion, wind" taxonomy===
Traditionally the orchestra is divided into three sections, strings, percussion, and wind. With strings and percussion instruments, the sound is produced by matter in its solid state, as for example, with a piano (which is both a string and a percussion instrument). With wind instruments sound is produced by matter in its gaseous state.

Hydraulophones add a new category of instruments in which sound is produced by water, unlike previously known instruments like the [[glass harmonica]] and the [[crystallophone]] which are idiophones that merely use the water to tune them or to enhance the friction. For example, the glass (h)armonica is a friction idiophone in which sound is produced by solid matter (glass), not liquid, even though liquid (water) is often present on the fingers of the armonist. The crystallophone is also an idiophone, in which water is used to change the tuning, but not to produce the actual sound. Thus hydraulophones form a unique class of instruments in which sound is actually produced by the water itself.

===Relationship to the pipe organ===
Many hydraulophones include a separate water-filled pipe for each note, and have sound-production means similar to pipe organs (but with water rather than air), while maintaining the flutelike user-interface (finger embouchure holes).

This form of hydraulophone is similar to an organ, but has water flowing through the pipes instead of air flowing through the pipes.

===Relationship to the piano===
On a concert hydraulophone, the finger holes are arranged like the keys on a piano, i.e. there is a row of uniformly spaced holes close to the player, and a row of holes that are in groups of 2, 3, 2, 3, ..., a little further from the player. Whereas the piano and organ both have a similar kind of keyboard layout, the response ("key action") is different. Pianos tend to respond to velocity (how quickly a key is struck), whereas organs tend to respond to displacement (whether or not a key is pressed down). Hydraulophones tend to respond to [[Derivatives of displacement#-1st derivative (integral) of displacement is absement|absement]] (the time-integral of displacement), as well as to displacement, velocity, and to some degree jerk and jounce[http://wearcam.org/acmmm2006/].

===Relationship to instruments that use other states-of-H2O===
[[Image:Pagophone2008 03 13 22 36 58.jpg|thumb|200px|Pagophone uses H2O in its solid state (i.e. ice), in contrast to the hydraulophone which typically uses H2O in its liquid state (i.e. water)]]
The hydraulophone uses liquid, typically water, H2O. It is thus related to the pagophone, an instrument that uses H2O in its solid state (i.e. ice), and the [[calliope (music)|calliope]], an instrument that uses H2O in its gaseous state (steam).

==World's largest hydraulophone==
[[Image:Hydraulophone at Ontario Science Centre imgp4940rp.jpg|thumb|200px|World's largest outdoor hydraulophone that's publicly accessible 24 hours-a-day]]
Presently the world's largest hydraulophone is the main architectural centerpiece out in front of the [[Ontario Science Centre]], one of Canada's landmark architecture sites. It is also Toronto's only freely accessible aquatic play facility that runs 24 hours a day.

==Markings on standard 12-jet hydraulophone==
[[Image:BrailleHydraulophoneMarkings2009 08 13 01 10 01.jpg|thumb|Braille markings above finger holes on a classroom hydraulophone used for teaching visually impaired students. The letter "L" denotes jet number 12 (rightmost in the sequence of 12 water jets).]]
Because the water-spray from hydraulophones obscures vision (or because hydraulophones are played underwater where visibility is poor), finger holes are sometimes encoded in Braille. Braille has the added advantage that the one-to-one correspondence between letters and numbers is the same as the standard A-minor hydraulophone, i.e. jet 1 is A, jet 2 is B, jet 3 is C, etc.. The skill (intricate sense of tactility) needed to play a hydraulophone well is also similar to the skill needed to read Braille.

[[Image:Braille A1.svg|30px|A, 1]]
[[Image:Braille B2.svg|30px|B, 2]]
[[Image:Braille C3.svg|30px|C, 3]]
[[Image:Braille D4.svg|30px|D, 4]]
[[Image:Braille E5.svg|30px|E, 5]]
[[Image:Braille F6.svg|30px|F, 6]]
[[Image:Braille G7.svg|30px|G, 7]]
[[Image:Braille H8.svg|30px|H, 8]]
[[Image:Braille I9.svg|30px|I, 9]]
[[Image:Braille J0.svg|30px|J, 0]]
[[Image:Braille K.svg|30px|K]]
[[Image:Braille L.svg|30px|L]]

(12 sets of dots typically made from brass pins above each finger hole)

==Manufacturers==
Hydraulophones are currently manufactured by:
* WhiteWater West in British Columbia, manufacturers of the [http://glogger.mobi/s/bestAquaTune AquaTune cylindrical-bore hydraulophone], and of the "Nessie" tapered-bore instrument;
* SCS Interactive, in Ogden, UT (business offices in Denver CO), manfacturers of the tapered-bore instrument called the "Hydrophone";
* FUNtain Corporation in Toronto, Ontario, Canada, manufacturers of a wide variety of hydraulophones and hydraulophone-related products.

==References and notes==
{{reflist}}

==External links==
*http://www.funtain.ca -- FUNtain makes and sells hydraulophones.
*http://wearcam.org/osc/opening -- Site devoted to world's largest hydraulophone, including opening day celebrations, etc..
*[http://www.ontariosciencecentre.ca/tour/teluscape/default.asp Ontario Science Centre website for Teluscape and its main centerpiece, the circular hydraulophone sculpture.]
*[http://hackedgadgets.com/2007/02/17/ontario-science-centre-hydraulophone-musical-keyboard-water-fountain/ Hacked Gadgets article on hydraulophones]
{{commonscat|Hydraulophone}}
[[Category:Experimental musical instruments]]
[[Category:Landscape architecture]]
[[Category:Sculpture terms]]
[[Category:Public art]]
[[Category:Outdoor sculptures]]
[[Category:Canadian inventions]]

[[id:Hydraulophone]]

Sleep Paralysis

2009-06-15T03:10:43Z

Sbmehta: capitalization

[[Image:John Henry Fuseli - The Nightmare.JPG|thumb|280px|''The Nightmare'', by [[Henry Fuseli]] (1781) is thought to be one of the classic depictions of sleep paralysis perceived as a [[demon]]ic visitation.]]

'''Sleep paralysis''' is a condition that may occur in normal subjects or be associated with [[narcolepsy]], [[cataplexy]], and [[hypnagogic hallucinations]]. The [[pathophysiology]] of this condition is closely related to the normal [[REM atonia|hypotonia]] that occur during [[REM sleep]].<ref>(From Adv Neurol 1995;67:245-271)</ref> When considered to be a disease, isolated sleep paralysis is classified as [[Medical Subject Headings|MeSH]] D020188.<ref> [http://www.nlm.nih.gov/cgi/mesh/2007/MB_cgi?field=uid&term=D020188 D020188]</ref> Some evidence suggests that it can also, in some cases, be a symptom of [[migraine]].<ref>http://www.dreaminglucid.com/articlejc.html</ref><ref>http://www.migraine-aura.org/content/e27891/e27265/e42285/e42290/e55289/e58636/index_en.html</ref>

==Symptoms and characteristics==

Physiologically, sleep paralysis is closely related to the paralysis that occurs as a natural part of REM (rapid eye movement) sleep, which is known as REM atonia. Sleep paralysis occurs when the [[brain]] awakes from a REM state, but the body paralysis persists. This leaves the person fully conscious, but unable to move. The paralysis can last from several seconds to several minutes "after which the individual may experience panic symptoms and the realization that the distorted perceptions were false".<ref>Hersen, Turner & Beidel. (2007) Adult Psychopathology and Diagnosis. p. 380</ref> When there is an absence of narcolepsy, sleep paralysis is referred to as isolated sleep paralysis (ISP).<ref>Hersen, Turner & Beidel. (2007) Adult Psychopathology and Diagnosis</ref> "ISP appears to be far more common and recurrent among blacks than among whites or Nigerian blacks",<ref>Hersen, Turner & Beidel. (2007) Adult Psychopathology and Diagnosis. p. 380</ref> and is often referred to within black communities as "the Devil on your back"<ref>Mattek, (2005) Memoirs p. 34</ref><ref name=>{{cite web|url=http://www.louisianafolklife.org/LT/Articles_Essays/main_misc_cauchemar.html|title=Contemporary Cauchemar: Experience, Belief, Prevention|work=Folklife in Louisiana|author=Katherine Roberts|publisher=The Louisiana Folklife Program}}</ref>

In addition, the paralysis state may be accompanied by terrifying [[hallucinations]] ([[hypnopompic]] or hypnagogic) and an acute sense of danger.<ref>Hersen Turner & Beidel. (2007) Adult Psychopathology and Diagnosis</ref> Sleep paralysis is particularly frightening to the individual due to the vividness of such hallucinations.<ref>Hersen, Turner & Beidel. (2007) Adult Psychopathology and Diagnosis</ref> The hallucinatory element to sleep paralysis makes it even more likely that someone will interpret the experience as a dream, since completely fanciful, or dream-like, objects may appear in the room alongside one's normal vision. Some scientists have proposed this condition as an explanation for [[alien abduction]]s and [[ghost]]ly encounters.<ref name="pmid15881271">{{cite journal |author=McNally RJ, Clancy SA. |title=Sleep Paralysis, Sexual Abuse, and Space Alien Abduction |journal=Transcultural Psychiatry |volume=42 |issue=1 |pages=113–122 |year=2005|pmid=15881271 |doi=10.1177/1363461505050715}}</ref> A study by [[Susan Blackmore]] and [[Marcus Cox]] of the [[University of the West of England]] supports the suggestion that reports of alien abductions are related to sleep paralysis rather than to [[temporal lobe]] lability.<ref name="ejufoas">{{cite journal | last = Blackmore | first = Susan | authorlink = Susan Blackmore | coauthors = Marcus Cox | title = Alien Abductions, Sleep Paralysis and the Temporal Lobe | journal = European Journal of UFO and Abduction Studies | volume = | issue = 1 | pages = pp. 113–118 | publisher = | location = | date = | url = http://72.14.235.132/search?q=cache:oDUW-O3VERkJ:www.susanblackmore.co.uk/Articles/ejufoas00.html+%22Alien+Abductions,+Sleep+Paralysis+and+the+Temporal+Lobe%22&cd=1&hl=en&ct=clnk&gl=au&client=firefox-a | doi = | id = | accessdate = 2008-07-26}}</ref>

==Possible causes==

Sleep paralysis occurs during [[Rapid eye movement sleep|REM]] sleep, thus preventing the body from manifesting movements made in the subject's dreams. Very little is known about the physiology of sleep paralysis.{{Fact|date=January 2008}} However, some have suggested that it may be linked to post-[[synapse|synaptic]] inhibition of [[motor neuron]]s in the [[pons]] region of the [[brain]].{{Fact|date=January 2008}} In particular, low levels of [[melatonin]] may stop the [[depolarization]] current in the nerves, preventing the stimulation of the muscles and any consequent enactment of the dream activity by the body (e.g. preventing a sleeper from flailing his legs when dreaming about running).{{Fact|date=January 2008}}

Several studies have concluded that many or most people will experience sleep paralysis at least once or twice in their lives.{{Fact|date=December 2007}}
A study conducted by Sedaghat F. et al. has investigated the prevalence of sleep paralysis among Iranian medical students. 24.1% of students reported experiencing sleep paralysis at least once in their lifetime. The same result was reported among Japanese, Nigerian, Kuwaiti, Sudanese and American students.<ref>Sedaghat-Hamedani F.,Kayvanpour E.,Rezai A.:" Prevalence of sleep paralysis and other symptoms of narcolepsy in Iranian medical students "</ref>

Many people who commonly enter sleep paralysis also suffer from [[narcolepsy]]. In African Americans, [[panic disorder]] occurs with sleep paralysis more frequently than in Caucasians.<ref>
Friedman, S. & Paradis, C. (2002). Panic disorder in Blacks: Symptomatology and isolated sleep paralysis. Cult Med Psychiatry. 2002 Jun;26(2):179-98 PMID 12211324 </ref>
Some reports read that various factors increase the likelihood of both paralysis and hallucinations. These include:<ref>{{cite web| author= J. A. Cheyne | url=http://watarts.uwaterloo.ca/~acheyne/prevent.html | title= Preventing and Coping with Sleep Paralysis | dateformat=mdy | accessdate=17 July 2006}}</ref>
* Sleeping in a face upwards or [[supine position]]
* Irregular sleeping schedules; naps, sleeping in, [[sleep deprivation]]
* Increased stress
* Sudden environmental/lifestyle changes
* A [[lucid dream]] that immediately precedes the episode.

==Treatment==
Treatment starts with patient education about sleep stages and about the muscle atonia that is typically associated with REM sleep. For most healthy individuals, avoiding chronic sleep deprivation is enough to relieve symptoms. It is recommended that patients be evaluated for [[narcolepsy]] if symptoms persist.<ref>Wills L, Garcia J. Parasomnias: Epidemiology and Management. CNS Drugs [serial online]. December 2002;16(12):803-810.</ref>

==Related phenomena==
Many perceptions associated with sleep paralysis (visceral buzzing, loud sounds, adrenal mental state, presences, and the paralysis itself) also constitute a common phase in the early progression of episodes referred to as [[out of body experience]]s.<ref>http://www.susanblackmore.co.uk/Conferences/SPR99.html "OBEs and Sleep Paralysis", Susan Blackmore</ref><ref>"The Projection of the Astral Body", 1968, Sylvan Muldoon and Hereward Carrington: chapter II, "Sensation and emotion at different stages of exteriorization" subsection</ref> Mental focus varies between the two conditions; paralysis sufferers tend to fixate on reestablishing operation of the body, whereas subjects of out-of-body episodes are more occupied by perceived non-equivalence with the body.

==Folklore==
{{No footnotes|section|date=May 2009}}
Complete references to many cultures are given in [[Sleep paralysis#References|the References section]]


* In African culture, isolated sleep paralysis is commonly referred to as "the witch riding your back".<ref>Mattek, (2005) Memoirs p. 34</ref><ref name=>{{cite web|url=http://www.louisianafolklife.org/LT/Articles_Essays/main_misc_cauchemar.html|title=Contemporary Cauchemar: Experience, Belief, Prevention|work=Folklife in Louisiana|author=Katherine Roberts|publisher=The Louisiana Folklife Program}}</ref>
* In the Cambodian, Laotian and Thai culture, sleep paralysis is referred to as "pee umm" and "khmout sukkhot". It describes an event where the person is sleeping and dreams that ghostly figure(s) are either holding him/her down or the ghosts can just be near. The person usually thinks that they are awake but is unable to move or make any noises. This is not to be confused with "pee khao" and "khmout jool" which refers to a ghost possession.
* In [[Hmong people|Hmong]] culture, sleep paralysis describes an experience called "dab tsog" or "crushing demon." Often the sufferer claims to be able to see a tiny figure, no larger than a child, sitting on his or her chest. What is alarming is that a vast number of American Hmong have died in their sleep, prompting the Centers for Disease Control to create the term "Sudden Unexpected Nocturnal Death Syndrome" (see [[Sudden unexplained death syndrome]]) or "SUNDS" for short; this is now theorized to be a form of [[Brugada syndrome]].
* In Vietnamese culture, sleep paralysis is referred to as "ma đè", meaning "held down by a ghost" or "bóng đè", meaning "held down by a shadow". Many people in this culture believe that a ghost has entered one's body, causing the paralyzed state.
* In [[Chinese culture]], sleep paralysis is widely known as "鬼壓身/鬼压身" ([[pinyin]]: guǐ yā shēn) or "鬼壓床/鬼压床" ([[pinyin]]: guǐ yā chuáng), which literally translate into "ghost pressing on body" or "ghost pressing on bed." A more modern term is "夢魘/梦魇" ([[pinyin]]: mèng yǎn); notice that the character "魘/魇" ([[pinyin]]: yǎn) is composed of "厭/厌" ([[pinyin]]: yàn), "to detest", and "鬼" ([[pinyin]]: guǐ), "ghost, demon".
* In [[Japanese language|Japanese]] culture, sleep paralysis is referred to as ''kanashibari'' ([http://ja.wikipedia.org/wiki/%E9%87%91%E7%B8%9B%E3%82%8A 金縛り], literally "bound or fastened in metal," from kane "metal" and shibaru" to bind, to tie, to fasten"). This term is occasionally used by English speaking authors to refer to the phenomenon both in academic papers and in [[popular psychology|pop psych]] literature.<ref name="shibaru">{{citation|title=High prevalence of isolated sleep paralysis: kanashibari phenomenon in Japan|author=Fukuda K, Miyasita A, Inugami M, Ishihara K.|work=Sleep|date=1987|chapter=Chapter 10|page=279-286}}</ref>
* In [[Culture of the Philippines|Philippine culture]], "bangungut", or [[sudden unexplained death syndrome]], has traditionally been attributed to nightmares.<ref>{{cite journal|last=Munger|first=Ronald G.|coauthors=Elizabeth A. Booton|year=1998|title=Bangungut in Manila: sudden and unexplained death in sleep of adult Filipinos|journal=[[International Journal of Epidemiology]]|publisher=[[International Epidemiological Association]]|location=Logan, UT|volume=27|issue=4|pages=677-684|url=http://ije.oxfordjournals.org/cgi/reprint/27/4/677.pdf|accessdate=May 28, 2009}}</ref> People who have claimed to survive such nightmares have reported experiencing the symptoms of sleep paralysis.{{fact|date=May 2009}}
* In [[Hungary|Hungarian]] folk culture sleep paralysis is called "lidércnyomás" ("lidérc pressing") and can be attributed to a number of supernatural entities like "lidérc" (wraith), "boszorkány" (witch), "tündér" (fairy) or "ördögszerető" (demon lover).<ref>[http://mek.oszk.hu/02100/02115/html/3-1332.html lidérc], Magyar Néprajzi Lexikon, Akadémiai Kiadó, Budapest 1977, ISBN</ref> The word "boszorkány" itself stems from the Turkish root "bas-", meaning "to press".<ref>[http://mek.oszk.hu/02100/02115/html/1-925.html boszorkány], Magyar Néprajzi Lexikon, Akadémiai Kiadó, Budapest 1977, ISBN</ref>
* In [[Iceland]] folk culture sleep paralysis is generally called having a "[[Mara (folklore)|Mara]]". Mara is an old Icelandic word for a mare but has taken on the meaning for a sort of a devil that sits on ones chest at night, trying to suffocate the victim.
* In [[Malta]], folk culture attributes a sleep paralysis incident to an attack by the "Haddiela" who is the wife of the "Hares", the entity in Maltese folk culture which haunts the individual in similar ways as to those of a poltergeist. As believed in folk culture, to rid oneself of the Haddiela, one must place a piece of silverware or a knife under the pillow prior to sleep.
*Kurdish people call this phenomenon a "mottaka", they believe that some one, in a form of a ghost or perhaps an evil spirit, turns up on top the of the person in the middle of the night and suffocates him/her. Apparently this happens usually when some one has done something bad.
*In New Guinea, people refer to this phenomenon as "Suk Ninmyo", believed to originate from sacred trees that use human essence to sustain its life. The trees are said to feed on human essence during night as to not disturb the human's daily life, but sometimes people wake unnaturally during the feeding, resulting in the paralysis.
*In [[Turkey|Turkish]] culture, sleep paralysis is often referred to as "karabasan" ("The dark presser/assailer"). It is believed to be a creature which attacks people in their sleep, pressing on their chest and stealing their breath.
*In Mexico, it's believed that sleep paralysis is in fact the spirit of a dead person getting on the person and impeding movement, calling this "se me subió el muerto" (the dead person got on me).
*In many parts of the Southern United States, the phenomenon is known as a "[[hag]]", and the event is said to often be a sign of an approaching tragedy or accident.
*Ogun Oru is a traditional explanation for nocturnal disturbances among the Yoruba of Southwest Nigeria; ogun oru (nocturnal warfare) involves an acute night-time disturbance that is culturally attributed to demonic infiltration of the body and psyche during dreaming. Ogun oru is characterized by its occurrence, a female preponderance, the perception of an underlying feud between the sufferer's earthly spouse and a 'spiritual' spouse, and the event of bewitchment through eating while dreaming. The condition is believed to be treatable through Christian prayers or elaborate traditional rituals designed to exorcise the imbibed demonic elements.<ref name="pmid17379609">{{cite journal |author=Aina OF, Famuyiwa OO |title=Ogun Oru: a traditional explanation for nocturnal neuropsychiatric disturbances among the Yoruba of Southwest Nigeria |journal=Transcultural psychiatry |volume=44 |issue=1 |pages=44–54 |year=2007 |pmid=17379609 |doi=10.1177/1363461507074968}}</ref>
*In [[Greece]] and [[Cyprus]], it is believed that sleep paralysis occurs when a ghost-like creature or Demon named Mora, Vrahnas or Varypnas (Greek: Μόρα, Βραχνάς, Βαρυπνάς) tries to steal the victim's speech or sits on the victim's chest causing asphyxiation.
* In Zimbabwean Shona culture the word Madzikirira is used to refer something really pressing one down. This mostly refers to the spiritual world in which some spirit—especially an evil one—tries to use its victim for some evil purpose. The people believe that witches can only be people of close relations to be effective, and hence a witches often try to use one's spirit to bewitch one's relatives.
* In Ethiopian culture the word Dukak is used. Dukak is believed to be some form of evil spirit that possesses people during their sleep. This experience is also believed to be related to use of [[Khat]]. Most Khat users experience sleep paralysis when quitting after a long time of use.
*Several studies have shown that African-Americans may be predisposed to isolated sleep paralysis also known as "the witch is riding you" or "the haint is riding you".<ref name="pmid6737506">{{cite journal |author=Bell CC, Shakoor B, Thompson B, Dew D, Hughley E, Mays R, Shorter-Gooden K |title=Prevalence of isolated sleep paralysis in black subjects |journal=Journal of the National Medical Association |volume=76 |issue=5 |pages=501–508 |year=1984 |pmid=6737506}}</ref> In addition, other studies have shown that African-Americans who have frequent episodes of isolated sleep paralysis, i.e., reporting having one or more sleep paralysis episodes per month coined as "sleep paralysis disorder," were predisposed to having panic attacks.<ref name="pmid3746934">{{cite journal |author=Bell CC, Dixie-Bell DD, Thompson B |title=Further studies on the prevalence of isolated sleep paralysis in black subjects |journal=Journal of the National Medical Association |volume=78 |issue=7 |pages=649–659 |year=1986|pmid=3746934}}</ref> This finding has been replicated by other independent researchers<ref name="pmid15881272">{{cite journal |author=Paradis CM, Friedman S |title=Sleep Paralysis in African Americans with Panic Disorder |journal=Transcultural psychiatry |volume=43 |issue=4 |pages=692–694 |year=2006 |pmid=15881272 |isbn=3461505050720 |doi=10.1177/1363461505050720}}</ref><ref name="pmid7982696">{{cite journal |author=Friedman S, Paradis CM, Hatch M |title=Characteristics of African-Americans and white patients with panic disorder and agoraphobia |journal=Hospital and Community Psychiatry |volume=45 |issue=8 |pages=798–803 |year=1994 |pmid=7982696}}</ref>
* In [[Culture of Pakistan|Pakistani culture]] & [[Culture of Bangladesh|Bangladeshi culture]], it is an encounter with evil [[Genie|jinn]]s and [[demon]]s. It is also assumed that it is due to the [[black magic]] performed by enemies and jealous persons. [[Curse]]s could also result in [[ghoul]] haunting a person. Some homes and locations are also haunted by these [[satan]]ic beings.
* In [[Tamil Nadu|Tamil]] and [[Culture of Sri Lanka|Sri Lankan]] Culture, this particular phenomenon is referred to as 'Amuku Be" or 'Amuku Pei' meaning "the ghost that forces one down".
* In Malay of Malay Peninsula, sleep paralysis is known as 'kena tindih' (or 'ketindihan' in Indonesia), which means "being pressed".<ref>http://sleepclinicjakarta.tblog.com/post/1969898557</ref> Incidents are commonly considered to be the work of a malign agency; occurring in what are explained as blind spots in the field of vision, they are reported as demonic figures.
* In [[Newfoundland and Labrador]], it is known as the 'Old Hag'.<ref name="OldHag">{{citation|author=Firestone, M.|title=The “Old Hag”: sleep paralysis in Newfoundland|work=The Journal of Psychoanalytic Anthropology|date=1985|chapter=Section 8|pages=47–66}}</ref> In island folklore, the Hag can be summoned to attack a third party, like a curse. In his 1982 book, ''The Terror that Comes in the Night'', David J. Hufford writes that in local culture the way to call the Hag is to recite the Lord's Prayer backwards. It is also common for believers to claim that those who are not wakened from this paralysis will die.
* In Persian it is known as 'bakhtak' (persian: بختک) which is a ghost-like creature who does this.

==Notes==
{{reflist|2}}

==References==
* Culhane-Pera, Kathie (2003). Healing by Heart: Clinical and Ethical Case Stories of Hmong Families and Western Providers. Vanderbilt University Press.
*Bower, Bruce (July 9, 2005). "[http://www.sciencenews.org/articles/20050709/bob9.asp Night of the Crusher]." ''Science News''.
*Conesa, J. (2000). Geomagnetic, cross-cultural and occupational faces of sleep paralysis: An ecological perspective. ''Sleep and Hypnosis'', 2, (3), 105-111.
*Conesa, J. (2002). Isolated Sleep Paralysis and Lucid Dreaming: Ten-year longitudinal case study and related dream frequencies, types, and categories. ''Sleep and Hypnosis'', 4, (4), 132-143.
*Conesa, J. (2003). Sleep Paralysis Signaling (SPS) As A Natural Cueing Method for the Generation and Maintenance of Lucid Dreaming. Presented at The 83rd Annual Convention of the Western Psychological Association, May 1 - 4, 2003 in Vancouver, BC, Canada.
*Conesa-Sevilla, Jorge (2004). Wrestling With Ghosts: A Personal and Scientific Account of Sleep Paralysis. Pennsylvania: Xlibris/Randomhouse.
*Firestone M. The “Old Hag”: sleep paralysis in Newfoundland. ''The Journal of Psychoanalytic Anthropology'' 1985; 8:47-66.
*Fukuda K, Miyasita A, Inugami M, Ishihara K. High prevalence of isolated sleep paralysis: kanashibari phenomenon in Japan. ''Sleep'' 1987; 10:279-286.
*Hartmann E. The nightmare: the psychology and biology of terrifying dreams. New York:Basic,1984.
*Hufford D.J. The terror that comes in the night: an experience-centered study of supernatural assault traditions. Philadelphia:University of Pennsylvania Press, 1982
*Kettlewell, N; Lipscomb, S; Evans, E. (June, 1993). "Differences in neuropsychological correlates between normals and those experiencing "Old Hag Attacks'." ''Perceptual and Motor Skills''. 76 (3 Pt 1): 839-45; discussion 846. PMID 8321596
* Ness RC. “The Old Hag” phenomenon as sleep paralysis: a bicultural interpretation. Culture, ''Medicine and Psychiatry'' 1978; 2:15-39.
*Ohayon MM, Zulley J, Guilleminault C, Smirne, S. Prevalence and pathologic associations of sleep paralysis in the general population. ''Neurology'', 1999; 52:1194-1200.
*Sagan, Carl (1997). ''The Demon-Haunted World: Science as a Candle in the Dark''.
* Schneck JM. Sleep paralysis and microsomatognosia with special reference to hypnotherapy. The ''International Journal of Clinical and Experimental Hypnosis'' 1977; XXV:72-77.
*Takeuchi T, Miyasita A, Sasaki Y, Inugami M, Fukuda K. Isolated sleep paralysis elicited by sleep interruption. ''American Sleep Disorders Association and Sleep Research Society'', 1992; 15: 217-225.

==External links==
* [http://www.spis.org.uk Sleep Paralysis Information Service]
* [http://www.stanford.edu/~dement/paralysis.html Sleep information and links] from Stanford University
* [http://www.arts.uwaterloo.ca/~acheyne/S_P.html Sleep Paralysis and Associated Hypnagogic and Hypnopompic Experiences] from University of Waterloo
* [http://www.csicop.org/doubtandabout/sleep/ Waking Up to Sleep Paralysis]

{{SleepSeries2}}

[[Category:Sleep physiology]]
[[Category:Sleep disorders]]
[[Category:Neuropsychology]]

[[ar:شلل النوم]]
[[ca:Paràlisi del son]]
[[da:Søvnparalyse]]
[[de:Bewegungsunfähigkeit im Schlaf]]
[[el:Παράλυση ύπνου]]
[[es:Parálisis del sueño]]
[[fa:فلج خواب]]
[[fr:Paralysie du sommeil]]
[[ko:가위눌림]]
[[it:Paralisi nel sonno]]
[[he:שיתוק שינה]]
[[lt:Miego paralyžius]]
[[nl:Slaapverlamming]]
[[ja:金縛り]]
[[no:Søvnparalyse]]
[[pl:Porażenie przysenne]]
[[pt:Catalepsia projetiva]]
[[ru:Сонный паралич]]
[[simple:Sleep paralysis]]
[[su:Eureup-eureup]]
[[fi:Unihalvaus]]
[[sv:Sömnparalys]]
[[tr:Uyku felci]]
[[zh:睡眠瘫痪症]]

Vitamin-B12-Mangel

2008-09-18T02:12:57Z

Sbmehta: capitalization

{{Infobox_Disease |
Name = {{PAGENAME}} |
Image = |
Caption = |
DiseasesDB = 13905 |
ICD10 = {{ICD10|E|53|8|e|50}} |
ICD9 = {{ICD9|266.2}} |
ICDO = |
OMIM = |
MedlinePlus = |
eMedicineSubj = |
eMedicineTopic = |
MeshID = D014806 |
}}
'''B12 deficiency''' is a reduction in [[vitamin B12]] from inadequate dietary intake or impaired absorption. The condition is commonly asymptomatic, but can also present as anemia characterized by enlarged blood corpuscles, so-called [[megaloblastic anemia]].
However in serious cases deficiency can potentially cause severe and irreversible damage to the nervous system, including [[subacute combined degeneration of spinal cord]].

The anemia is thought to be due to problems in DNA synthesis, specifically in the synthesis of [[thymine]], which is dependent on products of the [[5-methyltetrahydrofolate-homocysteine methyltransferase#reaction|MTR reaction]]. Other cell lines such as [[white blood cell]]s and [[platelet]]s are often also low. [[Bone marrow]] examination may show [[megaloblast]]ic [[hemopoiesis]]. The anemia is easy to cure with vitamin B12.

==Presentation==
Early and even fairly pronounced deficiency does not always cause distinct or specific symptoms. Common early symptoms are tiredness or a decreased mental work capacity, decreased concentration and decreased memory, irritability and depression.

Sleep disturbances may occur, because B12 may be involved in the regulation of the sleep wake cycle by the pineal gland (through melatonin)<ref name="pmid8981490">{{cite journal |author=Hashimoto S, Kohsaka M, Morita N, Fukuda N, Honma S, Honma K |title=Vitamin B12 enhances the phase-response of circadian melatonin rhythm to a single bright light exposure in humans |journal=Neurosci. Lett. |volume=220 |issue=2 |pages=129–32 |year=1996 |pmid=8981490 |doi=}}</ref>.

Neurological signs of B{{ssub|12}} deficiency, which can occur without anemia, include sensory disturbances due to damage to peripheral nerves caused by [[demyelination]] and irreversible nerve cell death. Symptoms include [[numbness]], tingling of the extremities, disturbed coordination and, if not treated in time, an [[ataxic gait]], a syndrome known as [[subacute combined degeneration of spinal cord]].

B-12 deficiency can also cause symptoms of mania and psychosis.<ref name="ijnwvitaminb12">{{cite journal | author=Sethi NK, Robilotti E, Sadan Y | title=Neurological Manifestations Of Vitamin B-12 Deficiency | journal=The Internet Journal of Nutrition and Wellness | volume=2 | issue=1 | year=2005 | doi=}}</ref><ref name="imajvitaminb12">{{cite journal |author=Masalha R, Chudakov B, Muhamad M, Rudoy I, Volkov I, Wirguin I |title=Cobalamin-responsive psychosis as the sole manifestation of vitamin B12 deficiency |journal=Isr. Med. Assoc. J. |volume=3 |issue=9 |pages=701–3 |year=2001 |pmid=11574992 |doi= |url=}}</ref>

Recent studies have devalued a possible connection between B12 deficiency and Alzheimer's dementia, and such a correlation is unlikely as of June 2007.<ref name="pmid16917153">{{cite journal |author=Morris MC, Evans DA, Schneider JA, Tangney CC, Bienias JL, Aggarwal NT |title=Dietary folate and vitamins B-12 and B-6 not associated with incident Alzheimer's disease |journal=J. Alzheimers Dis. |volume=9 |issue=4 |pages=435–43 |year=2006 |pmid=16917153 |doi=}}</ref>

Studies showing a relationship between [[clinical depression]] levels and deficient B{{ssub|12}} blood levels in elderly people are documented in the clinical literature.<ref>{{cite journal | author= Brenda W. J. H. Penninx ''et al''| title= Vitamin B{{ssub|12}} Deficiency and Depression in Physically Disabled Older Women: Epidemiologic Evidence From the Women’s Health and Aging Study | journal= Am. J. Psychiatry| year= 2000| volume= 157| pages= 715–721| pmid= 10784463| doi= 10.1176/appi.ajp.157.5.715}}</ref> and [[2002]] <ref>{{cite journal | author= Henning Tiemeier ''et al''| title= Vitamin B12, Folate, and Homocysteine in Depression: The Rotterdam Study| journal= Am. J. Psychiatry| year= 2002| volume= 159| pages= 2099–2101| pmid= 12450964| doi= 10.1176/appi.ajp.159.12.2099}}</ref>

[[Bipolar disorder]] appears to genetically co-segregate with the hereditary B12-deficiency disorder [[pernicious anemia]] <ref>{{cite journal | author=Reading CM. | title= X-linked dominant manic-depressive illness: Linkage with Xg blood-group, red-green color-blindness and vitamin-B12 deficiency. | journal= Orthomolecular Psychiatry | year= 1979 | volume= 8 | pages= 68–77| id= }}</ref><ref>{{cite journal |author=Reading CM |title=Latent pernicious anaemia: a preliminary report |journal=Med. J. Aust. |volume=1 |issue=4 |pages=91–4 |year=1975 |pmid=1134417 |doi= |url=}}</ref>.

[[Science Daily]] reported that "a deficiency of B-vitamins may cause [[vascular]] [[cognitive impairment]], according to a new study by the [[Jean Mayer]] [[USDA]] Human Nutrition Research Center on Aging (HNRCA) at [[Tufts University]]." Aron Troen, PhD, said that: "The vascular changes occurred in the absence of neurotoxic or degenerative changes. Metabolic impairments induced by a diet deficient in three B-vitamins -folate, B12 and B6- caused cognitive dysfunction and reductions in brain capillary length and density in our mouse model."<ref>[http://www.sciencedaily.com/releases/2008/09/080902095110.htm sciencedaily.com, B-vitamin Deficiency May Cause Vascular Cognitive Impairment]</ref><ref>[http://news.bbc.co.uk/2/hi/health/7595423.stm news.bbc.co.uk, Vitamin linked to brain shrinking]</ref><ref>[http://www.nytimes.com/2008/09/09/health/09agin.html nytimes.com, Aging: Lack of B12 Linked to Brain Shrinkage]</ref><ref>[http://www.webmd.com/brain/news/20080908/vitamin-b12-boasts-brain-benefits webmd.com, Vitamin B12 Boasts Brain Benefits Simple Dietary Changes May Help Ward Off Brain Volume Loss in Old Age]</ref>

==Causes==
* Inadequate dietary intake of vitamin B12. As the vitamin B12 occurs naturally only in animal products (eggs, meat, milk), and a particular strain of [[nutritional yeast]]; a [[vegan]] diet can produce a deficiency unless one uses supplements or eats enriched food.<ref>[http://www.pernicious-anaemia-society.org/whatispa.html Pernicious Anaemia Society - What is Pernicious Anaemia?], retrieved July 30, 2007.</ref><ref name="isbn0-8493-9218-7">{{cite book |author=Feldman, Elaine B.; Berdanier, Carolyn D.; Dwyer, Johanna T. |title=Handbook of Nutrition and Food, Second Edition |publisher=CRC |location=Boca Raton |year=2007 |pages= |isbn=0-8493-9218-7 |oclc= |doi= |accessdate=}}</ref>

* Selective impaired absorption of vitamin B12 due to [[intrinsic factor]] deficiency. This may depend on loss of [[stomach|gastric]] [[parietal cells]] in chronic [[atrophic gastritis]] (in which case, the resulting [[megaloblastic anaemia]] takes the name of "[[pernicious anaemia]]"), or on wide surgical resection of stomach (such as in [[bariatric surgery]]), or on rare hereditary causes of impaired synthesis of intrinsic factor.

* Impaired absorption of vitamin B12 in the setting of a more generalised [[malabsorption]] or [[maldigestion]] syndrome. This includes any form of structural damage or wide surgical resection of the terminal [[ileum]] (the principal site of vitamin B12 absorption), forms of [[achlorhydria]] (including that artificially induced by drugs such as [[proton pump inhibitors]]), as well as [[bacterial overgrowth]] (such as in [[blind loop syndrome]]).

* Chronic intestinal infestation by the [[fish tapeworm]] ''[[Diphyllobothrium]]'', that competes for vitamin B12, seizing it for its own use and therefore leaving insufficient amount for the host organism. This is mostly confined to [[Scandinavia]] and parts of [[Eastern Europe]] (for example, in preparers of [[gefilte fish]], who would acquire the tapeworm by sneaking bits of fish before it was cooked while making the Eastern European delicacy).

* The [[diabetes]] medication, [[metformin]] may interfere with B12 dietary absorption.<ref>{{cite journal | author = Ting R, Szeto C, Chan M, Ma K, Chow K | title = Risk factors of vitamin B(12) deficiency in patients receiving metformin | journal = Arch Intern Med | volume = 166 | issue = 18 | pages = 1975–9 | year = 2006 | pmid = 17030830 | doi = 10.1001/archinte.166.18.1975}}</ref>

* Hereditary causes such as severe [[MTHFR]] deficiency, [[homocystinuria]], and [[transcobalamin]] deficiency.

* Some studies have shown that [[giardiasis]], or similar [[parasite]] should be considered as a cause of [[Vitamin B12 deficiency]], this a result of the problems caused within the intestinal absorption system. <ref>{{cite journal |author=Cordingley FT, Crawford GP |title=Giardia infection causes vitamin B12 deficiency |journal=Aust N Z J Med |volume=16 |issue=1 |pages=78–9 |year=1986 |pmid=3458451 |doi= |url=}}</ref>

==Incidence/prevalence==

Recent research indicates that B12 deficiency is far more widespread than formerly believed. A large study in the US found that 39 percent had low values.<ref>{{cite web |url=http://www.ars.usda.gov/is/pr/2000/000802.htm |title=B12 Deficiency May Be More Widespread Than Thought / August 2, 2000 / News from the USDA Agricultural Research Service |accessdate=2007-07-01 |format= |work=}}</ref> This study at Tufts University used the B12 concentration 258 pmol/l (= 350 pg/liter) as a criterion of "low level". However, recent research has found that B12 deficiency may occur at a much higher B12 concentration (500-600 pg/l). On this basis Mitsuyama and Kogoh <ref name=Mitsuyama>{{cite journal |author=Mitsuyama Y, Kogoh H |title=Serum and cerebrospinal fluid vitamin B12 levels in demented patients with CH3-B12 treatment--preliminary study |journal=Jpn. J. Psychiatry Neurol. |volume=42 |issue=1 |pages=65–71 |year=1988 |pmid=3398357 |doi= |url=}}</ref>. proposed 550 pg/l, and Tiggelen et al <ref>{{cite journal | author=VanTiggelen CJM, Peperkamp JPC, TerToolen JFW. | journal=Journal of Orthomolecular Psychiatry | year=1983 | title=Vitamin-B12 levels of cerebrospinal fluid in patients with organic mental disorder. | pages=305–11 | volume= | issue=12 }}</ref> proposed 600 pg/l. Against this background, there are reasons to believe that B12 deficiency is present in a far greater proportion of the population than 39% as reported by Tufts University.

In the developing world the deficiency is very widespread, with significant levels of deficiency in Africa, India, and South and Central America. This is due to low intakes of animal products, particular among the poor. Increased intake of animal products or supplements have been suggested.<ref>{{cite journal |author=Baik HW, Russell RM |title=Vitamin B12 deficiency in the elderly |journal=Annu. Rev. Nutr. |volume=19 |issue= |pages=357–77 |year=1999 |pmid=10448529 |doi=10.1146/annurev.nutr.19.1.357 |url=}}</ref>

B12 deficiency is even more common in the elderly <ref>{{cite journal |author=Baik HW, Russell RM |title=Vitamin B12 deficiency in the elderly |journal=Annu. Rev. Nutr. |volume=19 |issue= |pages=357–77 |year=1999 |pmid=10448529 |doi=10.1146/annurev.nutr.19.1.357 |url=}}</ref>. This is because B{{ssub|12}} absorption decreases greatly in the presence of atrophic gastritis, which is common in elderly.

B12 deficiency is common among vegetarians and vegans who do not take B12 supplements. In vegans the risk is very high because none of their natural food sources contain B12. One American study found blood levels below normal in 92 % of vegans, 64 % of lactovegetarians, 47 % of lacto-ovovegetarians who did not supplement their diet with B12. <ref>{{cite journal |author=Dong A, Scott SC |title=Serum vitamin B12 and blood cell values in vegetarians |journal=Ann. Nutr. Metab. |volume=26 |issue=4 |pages=209–16 |year=1982 |pmid=6897159 |doi= |url=}}</ref>. The study applied the old normal values, so in reality a considerably greater proportion may have been deficient.

==Diagnosis==
[[Serum]] B{{ssub|12}} levels are often low in B{{ssub|12}} deficiency, but if other features of B{{ssub|12}} deficiency are present with normal B{{ssub|12}} then the diagnosis must not be discounted. One possible explanation for normal B{{ssub|12}} levels in B{{ssub|12}} deficiency is antibody interference in people with high titres of [[intrinsic factor antibody]].<ref>{{cite journal |author=Hamilton MS, Blackmore S, Lee A |title=Possible cause of false normal B-12 assays |journal=BMJ |volume=333 |issue=7569 |pages=654–5 |year=2006 |pmid=16990334 |pmc=1570871 |doi=10.1136/bmj.333.7569.654-c |url=}}</ref>
Some researchers propose that the current standard norms of vitamin B12 levels are too low{{Fact|date=July 2007}}. In Japan, the lowest acceptable level for vitamin B12 in blood has been raised from about 200 picograms/litre (pg/l) = 145 picomol/litre (pm/l) to 550 pg/l = 400 pm/l{{Fact|date=July 2007}}. <ref name=Mitsuyama/>

Serum Homocysteine and Methylmalonic acid levels are considered more reliable indicators of B12 deficiency than the concentration of B12 in blood, see for example research at the [[St. Louis University]].<ref name="titleTest used to diagnose B12 deficiency may be inadequate">{{cite web |url=http://www.news-medical.net/?id=5908 |title=Test used to diagnose B12 deficiency may be inadequate |accessdate=2007-12-04 |format= |work=}}</ref> The levels of these substances are high in B{{ssub|12}} deficiency and can be helpful if the diagnosis is unclear. Approximately 10% of patients with vitamin B12 levels between 200-400pg/l will have a vitamin B12 deficiency on the basis of elevated levels of [[homocysteine]] and [[methylmalonic acid]].{{Fact|date=July 2007}}

Routine monitoring of [[methylmalonic acid]] levels in urine is an option for people who may not be getting enough dietary B{{ssub|12}}, as a rise in [[methylmalonic acid]] levels may be an early indication of deficiency.<ref name="donaldson">{{cite journal |author=Donaldson MS |title=Metabolic vitamin B{{ssub|12}} status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements |journal=Ann. Nutr. Metab. |volume=44 |issue=5-6 |pages=229–34 |year=2000 |pmid=11146329 |doi= |url=http://content.karger.com/produktedb/produkte.asp?typ=fulltext&file=anm44229}}</ref>

If nervous system damage is suspected, B12 analysis in cerebrospinal fluid can also be helpful, though such an invasive test would be applicable only after unrevealing blood testing.<ref>{{cite journal | author=Devalia V | title=Diagnosing vitamin B-12 deficiency on the basis of serum B-12 assay | journal=Brit J Med | year=2006 | volume=333 | issue=7564 | pages=385–6 | pmid= 16916826 | doi=10.1136/bmj.333.7564.385 }}</ref>

==Treatment==
B{{ssub|12}} can be supplemented in healthy subjects by oral pill; [[sublingual]] pill, liquid, or strip; or by injection. B{{ssub|12}} is available singly or in combination with other supplements. B{{ssub|12}} supplements are available in forms including [[cyanocobalamin]], [[hydroxocobalamin]], [[methylcobalamin]], and [[adenosylcobalamin]] (sometimes called "cobamamide" or "dibencozide").

Vitamin B{{ssub|12}} can be given as intramuscular injections of [[hydroxycobalamin]], [[methylcobalamin]], or [[cyanocobalamin]]. Body stores (in the liver) are refilled with half a dozen injections in the first couple of weeks and then maintenance with monthly to quarterly injections throughout the life of the [[patient]].

B{{ssub|12}} has traditionally been given [[parenterally]] to ensure absorption. However, oral replacement is now an accepted route, as it has become increasingly appreciated that sufficient quantities of B{{ssub|12}} are absorbed when large doses are given. This absorption does not rely on the presence of intrinsic factor or an intact ileum. Generally 1 to 2 mg daily is required as a large dose [http://www.bloodjournal.org/cgi/content/full/92/4/1191]. By contrast, the typical Western diet contains 5–7 µg of B{{ssub|12}} ([[Food and Drug Administration]] (FDA) Daily Value <ref>{{cite web| url = http://dietary-supplements.info.nih.gov/factsheets/vitaminb12.asp | title = Dietary Supplement Fact Sheet: Vitamin B12| publisher = National Institutes of Health: Office of Dietary Supplements | accessdate = 2006-06-06 }}</ref>).

[[Hypokalemia]], an excessive low [[potassium]] level in the [[blood]], is anecdotally reported as a complication of vitamin B{{ssub|12}} repletion after deficiency. Excessive quantities of [[potassium]] are used by newly growing and dividing [[hematopoeitic]] cells, depleting circulating stores of the [[mineral]].

It has been appreciated since the 1960s that deficiency can sometimes be treated with oral B{{ssub|12}} supplements when given in sufficient doses. When given in oral doses ranging from 0.1–2 mg daily, B{{ssub|12}} can be absorbed in a pathway that does not require an intact ileum or intrinsic factor. However, with the advent of sublingual and intranasal administration, tablet usage is becoming outdated. <ref>{{cite journal | author= Antoinette M. Kuzminski ''et al''| title= Effective Treatment of Cobalamin Deficiency With Oral Cobalamin| journal= Blood| year= 1998| volume= 92| issue= 4| pages= 1191–8| pmid= 9694707}}</ref><ref>{{cite journal | journal=Fam Pract | year=2006 | volume=23 | issue=3 | pages=279–85 | title=Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency: a systematic review of randomized controlled trials | author=Butler CC, Vidal-Alaball J, Cannings-John R, ''et al.'' | pmid=16585128 | doi=10.1093/fampra/cml008 }}</ref> Oral absorption is limited so regular intramuscular injections or sublingual/intranasal administration of a cobalamin (preferably methyl- or hydroxycobalamin) is necessary to restore systemic stores to physiological levels. Recent research indicates that sublingual administration eliminates a deficiency as well as injections (reference will be added) with the advantage of evading the allergy risk.

===Natural Food Sources of B-12===

Vitamin B12 is found in foods that come from animals, including fish, meat, poultry, eggs, milk, and milk products and fortified breakfast cereals.<ref>[http://ods.od.nih.gov/factsheets/vitaminB12.asp Dietary Supplement Fact Sheet: Vitamin B12]</ref> One half chicken breast, provides some .3 mc grams per serving or 6% of your daily value (DV), 3 ounces of beef, 2.4 mc grams, or 40% of your DV, one slice liver 47.9 mc grams or 780% of your DV, and 3 ounces of molluscs 84.1 mc grams, or 1,400% of your DV, while one egg provides .6 mc grams or 10% of your DV. Vegetarians have a challenge to ensure that they meet their daily allowance for B-12.

==References==
{{Reflist|2}}

{{Nutritional pathology}}

[[pl:Niedobór witaminy B12]]
[[pt:Deficiência de vitamina B12]]