異化型の、異化性の

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/06/18 10:49:35」(JST)

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For the chemical term, see catabolism

In phonology, particularly within historical linguistics, dissimilation is a phenomenon whereby similar consonant or vowel sounds in a word become less similar. For example, when one /r/ sound occurs before another in the middle of a word in rhotic dialects of English, the first tends to drop out, as in "beserk" for berserk, "supprise" for surprise, "paticular" for particular, and "govenor" for governor (this does not affect the pronunciation of government, which has only one /r/). [1]

Causes

There are several hypotheses as to what causes dissimilation. John Ohala posits that listeners are confused by sounds that have long-distance acoustic effects. In the case of English /r/, rhoticization spreads across much of the word (that is, in rapid speech many of the vowels may sound like they have an R in them), and it may be difficult to tell whether a word has one source of rhoticity or two. When there are two, a listener might wrongly interpret one as an acoustic effect of the other, and so mentally filter it out.

This factoring out of coarticulatory effects has been experimentally replicated. For example, Greek pakhu- (παχυ-) "thick" derives from an earlier *phakhu-. When test subjects are asked to say the *phakhu- form in casual speech, the aspiration from both consonants pervades both syllables, making the vowels breathy.^{[citation needed]} Listeners hear a single effect—breathy voiced vowels—and attribute it to one rather than both of the consonants, assuming the breathiness on the other syllable to be a long-distance coarticulatory effect, thus replicating the historical change in the Greek word.^{[citation needed]}

If Ohala is correct, one might expect to find dissimilation in other languages with other sounds that frequently cause long-distance effects, such as nasalization and pharyngealization.

Examples

In English r deletion above, when a syllable is unstressed, it may drop out altogether, as in "deteriate" for deteriorate, "tempature" for temperature, and "apeture" for aperture, a process called haplology. When the /r/ is found as /bru/, it may change to /j/: "Febyuary" for February, "defibyulator" for defibrillator, though this may be due to analogy with words such as January.

Types of dissimilation

Dissimilation, like assimilation, may involve a change in pronunciation relative to a segment that is adjacent to the affected segment or at a distance, and may involve a change relative to a preceding or a following segment. As with assimilation, anticipatory dissimilation is much more common than lag dissimilation, but unlike assimilation, most dissimilation is triggered by non-contiguous segments. Also, while many kinds of assimilation have the character of a sound law, few dissimilations do; most are in the nature of accidents that befall a particular lexical item.

Anticipatory dissimilation at a distance (by far the most common):

Latin *medio-diēs ("mid-day", i.e. "noon"; also "south") became merīdiēs. Latin venēnum "poison" > Italian veleno. This category includes a rare example of a systematic sound law, the dissimilation of aspirates in Greek and Sanskrit known as Grassmann's Law: *thi-thē-mi "I put" (with a reduplicated prefix) > Greek tí-thē-mi (τίθημι), *phakhu "thick" > Greek pákhus (πάχυς), *sekhō "I have" > *hekhō > Greek ékhō (ἔχω; cf. future *hekh-s-ō > héksō ἕξω). Some apparent cases are problematic, as in English "eksetera" for etcetera, which may rather be contamination from the numerous forms in eks- (or a combination of influences), though the common misspelling ect. implies dissimilation.

Anticipatory dissimilation from a contiguous segment (very rare):

The change from fricative to stop articulation in a sequence of fricatives may belong here: German sechs /zeks/ (as evidenced by the spelling, the /k/ was previously a fricative). In Sanskrit in any original sequence of two sibilants the first became a stop (often with further developments): root vas- "dress", fut. vas-sya- > vatsya-; *wiś-s "clan" (nom.sg.) > *viťś > *viṭṣ > viṭ (final clusters are simplified); *wiś-su locative pl. > *viṭṣu > vikṣu. English amphitheater is very commonly pronounced ampitheater (though spelling pronunciation may be either some or all of the story here).

Lag dissimilation at a distance (fairly common):

Latin rārus "rare" > Italian rado. Cardamom the spice commonly cardamon. In Middle English, in a whole list of words ending in -n but preceded by an apical consonant the -n changed to -m: seldom, whilom, random, venom. Eng. marble is ultimately from Latin marmor. Russian февраль /fevrˈalʲ/ "February" is from Lat. Februārius.

Lag dissimilation from a contiguous segment (very rare):

Latin hominem ("man", acc.) > Old Spanish omne > omre > Spanish hombre
Latin nominem ("name", acc.) > nomre > Sp. nombre
English chimney (standard) > chim(b)ley (dialectal)
Proto-Slavic *"sveboda" "freedom" > Slovak "sloboda"

Paradigmatic dissimilation

When, through sound change, elements of a grammatical paradigm start to conflate in a way that is not easily remedied through re-wording, the forms may dissimilate. For example, in modern Korean the vowels /e/ and /ɛ/ are merging for many people in the capital Seoul, and concurrently the second-person pronoun 네 /ne/ 'you' is shifting to 니 /ni/ to avoid confusion with the first-person pronoun 내 /nɛ/ 'me'.

Similarly, it appears that English she, historically heo, may have acquired its modern sh form through dissimilation from he, though it is not clear whether the mechanism was idiosyncratic sound change (palatalization) of heo, or substitution of heo with the feminine demonstrative pronoun seo.

References

Crowley, Terry. (1997) An Introduction to Historical Linguistics. 3rd edition. Oxford University Press.
Vasmer's dictionary
Dissimilation (International Encyclopedia of Linguistics, 2nd ed.)

English Journal

Dissimilatory antimonate reduction and production of antimony trioxide microcrystals by a novel microorganism.

Abin CA, Hollibaugh JT.Author information Department of Microbiology, University of Georgia , Athens, Georgia 30602, United States.AbstractAntimony (Sb) is a metalloid that has been exploited by humans since the beginning of modern civilization. The importance of Sb to such diverse industries as nanotechnology and health is underscored by the fact that it is currently the ninth-most mined metal worldwide. Although its toxicity mirrors that of its Group 15 neighbor arsenic, its environmental chemistry is very different, and, unlike arsenic, relatively little is known about the fate and transport of Sb, especially with regard to biologically mediated redox reactions. To further our understanding of the interactions between microorganisms and Sb, we have isolated a bacterium that is capable of using antimonate [Sb(V)] as a terminal electron acceptor for anaerobic respiration, resulting in the precipitation of antimonite [Sb(III)] as microcrystals of antimony trioxide. The bacterium, designated strain MLFW-2, is a sporulating member of a deeply branching lineage within the order Bacillales (phylum Firmicutes). This report provides the first unequivocal evidence that a bacterium is capable of conserving energy for growth and reproduction from the reduction of antimonate. Moreover, microbiological antimonate reduction may serve as a novel route for the production of antimony trioxide microcrystals of commercial significance to the nanotechnology industry.
Environmental science & technology.Environ Sci Technol.2014 Jan 7;48(1):681-8. doi: 10.1021/es404098z. Epub 2013 Dec 17.
Antimony (Sb) is a metalloid that has been exploited by humans since the beginning of modern civilization. The importance of Sb to such diverse industries as nanotechnology and health is underscored by the fact that it is currently the ninth-most mined metal worldwide. Although its toxicity mirrors
PMID 24319985

Microbiological reduction of sb(v) in anoxic freshwater sediments.

Kulp TR, Miller LG, Braiotta F, Webb SM, Kocar BD, Blum JS, Oremland RS.Author information Department of Geological Sciences and Environmental Studies, Binghamton University, SUNY , Binghamton, New York 13902, United States.AbstractMicrobiological reduction of millimolar concentrations of Sb(V) to Sb(III) was observed in anoxic sediments from two freshwater settings: (1) a Sb- and As-contaminated mine site (Stibnite Mine) in central Idaho and 2) an uncontaminated suburban lake (Searsville Lake) in the San Francisco Bay Area. Rates of Sb(V) reduction in anoxic sediment microcosms and enrichment cultures were enhanced by amendment with lactate or acetate as electron donors but not by H2, and no reduction occurred in sterilized controls. Addition of 2-(14)C-acetate to Stibnite Mine microcosms resulted in the production of (14)CO2 coupled to Sb(V) reduction, suggesting that this process proceeds by a dissimilatory respiratory pathway in those sediments. Antimony(V) reduction in Searsville Lake sediments was not coupled to acetate mineralization and may be associated with Sb-resistance. The microcosms and enrichment cultures also reduced sulfate, and the precipitation of insoluble Sb(III)-sulfide complexes was a major sink for reduced Sb. The reduction of Sb(V) by Stibnite Mine sediments was inhibited by As(V), suggesting that As(V) is a preferred electron acceptor for the indigenous community. These findings indicate a novel pathway for anaerobic microbiological respiration and suggest that communities capable of reducing high concentrations of Sb(V) commonly occur naturally in the environment.
Environmental science & technology.Environ Sci Technol.2014 Jan 7;48(1):218-26. doi: 10.1021/es403312j. Epub 2013 Dec 9.
Microbiological reduction of millimolar concentrations of Sb(V) to Sb(III) was observed in anoxic sediments from two freshwater settings: (1) a Sb- and As-contaminated mine site (Stibnite Mine) in central Idaho and 2) an uncontaminated suburban lake (Searsville Lake) in the San Francisco Bay Area. R
PMID 24274659

Predominant acidilobus-like populations from geothermal environments in yellowstone national park exhibit similar metabolic potential in different hypoxic microbial communities.

Jay ZJ, Rusch DB, Tringe SG, Bailey C, Jennings RM, Inskeep WP.Author information Thermal Biology Institute and Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, Montana, USA.AbstractHigh-temperature (>70°C) ecosystems in Yellowstone National Park (YNP) provide an unparalleled opportunity to study chemotrophic archaea and their role in microbial community structure and function under highly constrained geochemical conditions. Acidilobus spp. (order Desulfurococcales) comprise one of the dominant phylotypes in hypoxic geothermal sulfur sediment and Fe(III)-oxide environments along with members of the Thermoproteales and Sulfolobales. Consequently, the primary goals of the current study were to analyze and compare replicate de novo sequence assemblies of Acidilobus-like populations from four different mildly acidic (pH 3.3 to 6.1) high-temperature (72°C to 82°C) environments and to identify metabolic pathways and/or protein-encoding genes that provide a detailed foundation of the potential functional role of these populations in situ. De novo assemblies of the highly similar Acidilobus-like populations (>99% 16S rRNA gene identity) represent near-complete consensus genomes based on an inventory of single-copy genes, deduced metabolic potential, and assembly statistics generated across sites. Functional analysis of coding sequences and confirmation of gene transcription by Acidilobus-like populations provide evidence that they are primarily chemoorganoheterotrophs, generating acetyl coenzyme A (acetyl-CoA) via the degradation of carbohydrates, lipids, and proteins, and auxotrophic with respect to several external vitamins, cofactors, and metabolites. No obvious pathways or protein-encoding genes responsible for the dissimilatory reduction of sulfur were identified. The presence of a formate dehydrogenase (Fdh) and other protein-encoding genes involved in mixed-acid fermentation supports the hypothesis that Acidilobus spp. function as degraders of complex organic constituents in high-temperature, mildly acidic, hypoxic geothermal systems.
Applied and environmental microbiology.Appl Environ Microbiol.2014 Jan;80(1):294-305. doi: 10.1128/AEM.02860-13. Epub 2013 Oct 25.
High-temperature (>70°C) ecosystems in Yellowstone National Park (YNP) provide an unparalleled opportunity to study chemotrophic archaea and their role in microbial community structure and function under highly constrained geochemical conditions. Acidilobus spp. (order Desulfurococcales) compris
PMID 24162572

Japanese Journal

Comparison of Sulphate-reducing Bacterial Communities in Japanese Fish Farm Sediments with Different Levels of Organic Enrichment

KONDO RYUJI,MORI YUMI,SAKAMI TOMOKO
Microbes and environments 27(2), 193-199, 2012-06-01
… The SRB community composition was assessed using PCR amplification, cloning, sequencing and phylogenetic analysis of the dissimilatory sulphite reductase b-subunit gene (dsrB) fragments using directly extracted sediment DNA. …
NAID 10030432139

冷蔵および冷凍保存された地下水中の無機態窒素濃度と有機物濃度の変動

玉村修司,酒井利彰,清水了 [他],石島洋二,五十嵐敏文
地下水学会誌 54(2), 107-116, 2012-05-31
北海道幌延町下沼地区で，深度37m（S1），45m（S2）および75m（S3）の地下水をサンプリングした。ろ過せず冷蔵（4℃）および冷凍（－20℃）保存されたサンプル中の無機態窒素濃度の変動と，有機物濃度の変動との関係を調べた。その結果，サンプル中のNO<SUB>3</SUB><SUP>－</SUP>，NO<SUB& …
NAID 10030744449

Abundance of sulphate-reducing bacteria in fish farm sediments along the coast of Japan and South Korea

Kondo Ryuji,Shigematsu Kotaro,Kawahara Naoki [他],OKAMURA Takahiko,YOON Yang Ho,SAKAMI Tomoko,YOKOYAMA Hisashi,KOIZUMI Yoshitsugu
Fisheries science : FS 78(1), 123-131, 2012-01-01
NAID 10030025237

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★リンクテーブル★

リンク元	「異化型」「異化性」

「異化型」

Sound change and alternation
	Metathesis Quantitative metathesis
	Lenition Consonant gradation; Consonant voicing and devoicing; Assibilation; L-vocalization; Debuccalization
	Fortition
	Epenthesis Anaptyxis; Excrescence; Prosthesis; Paragoge; Unpacking; Vowel breaking
	Elision Apheresis; Syncope; Apocope; Haplology; Fusion; Cluster reduction
	Cheshirization Compensatory lengthening; Nasalization; Tonogenesis; Floating tone
	Assimilation Coalescence; Coarticulation; Palatalization; Velarization; Labialization; Final devoicing; Metaphony (vowel harmony, umlaut); Consonant harmony
	Dissimilation
	Sandhi Liaison, linking R; Consonant mutation; Tone sandhi; Hiatus; Synalepha Elision; Crasis; Synaeresis and diaeresis; Synizesis
	Other types Iotacism; Lambdacism; Rhotacism; Sigmatism; Rhinoglottophilia; Sulcalization
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英: dissimilatory
関: 異化性

「異化性」

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英: dissimilatory
関: 異化型

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dissimilatory