WordNet

get used to a certain climate; "They never acclimatized in Egypt" (同)acclimatise, acclimate
adaptation to a new climate (a new temperature or altitude or environment) (同)acclimatisation, acclimation

PrepTutorEJDIC

=acclimate
=acclimation
新しい環境(風土)に慣れること,順応;順化
《米》〈人・生物〉'を'新しい環境(風土)に慣れさせる《+『名』+『to』+『名』(do『ing』)》

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/03/08 18:47:04」(JST)

wiki en

[Wiki en表示]

Acclimatization (UK also acclimatisation; US also acclimation) is the process in which an individual organism adjusts to a gradual change in its environment (such as a change in temperature, humidity, photoperiod, or pH), allowing it to maintain performance across a range of environmental conditions. Acclimation occurs in a short period of time (days to weeks), and within the organism's lifetime (compare to adaptation). This may be a discrete occurrence or may instead represent part of a periodic cycle, such as a mammal shedding heavy winter fur in favor of a lighter summer coat. Organisms can adjust their morphological, behavioral, physical, and/or biochemical traits in response to changes in their environment.^[1] While the capacity to acclimate to novel environments has been well documented in thousands of species, researchers still know very little about how and why organisms acclimate the way that they do. When used as a technical term (such as in the study of physiology), acclimatization refers to a natural process (e.g., shedding heavy winter fur with natural seasonal change), whereas the term acclimation is reserved for changes occurring in response to an artificial or controlled situation, such as changes in temperature imposed in an experimental manipulation.

Methods

Biochemical

In order to maintain performance across a range of environmental conditions, there are several strategies organisms use to acclimate. In response to changes in temperature, organisms can change the biochemistry of cell membranes making them more fluid in cold temperatures and less fluid in warm temperatures by increasing the number of membrane proteins.^[2] Organisms may also express specific proteins called heat shock proteins that may act as molecular chaperons and help the cell maintain function under periods of extreme stress. It has been shown, that organisms which are acclimated to high or low temperatures display relatively high resting levels of heat shock proteins so that when they are exposed to even more extreme temperatures the proteins are readily available. Expression of heat shock proteins and regulation of membrane fluidity are just two of many biochemical methods organisms use to acclimate to novel environments. Note: acclimation and acclimatization are two very different terms that are not interchangeable. Acclimation is used under laboratory conditions, while acclimatization is "in the field" or in nature.^[3]

Morphological

Organisms are able to change several characteristics relating to their morphology in order to maintain performance in novel environments. Examples may include changing of skin color or pattern to allow for efficient thermoregulation, or a change in body size of offspring as a result of low food levels in the ecosystem.

Theory

While the capacity for acclimation has been documented in thousands of species, researches still know very little about how and why organisms acclimate in the way that they do. Since researchers first began to study acclimation, the overwhelming hypothesis has been that all acclimation serves to enhance the performance of the organism. This idea has come to be known as the beneficial acclimation hypothesis. Despite such widespread support for the beneficial acclimation hypothesis, not all studies show that acclimation always serves to enhance performance (See beneficial acclimation hypothesis). One of the major objections to the beneficial acclimation hypothesis is that it assumes that there are no costs associated with acclimation.^[4] However, there are costs associated with acclimation, such as the energetic costs in expressing heat shock proteins.

Given the shortcomings of the beneficial acclimation hypothesis, researchers are continuing to search for a theory that will be supported by empirical data.

The degree to which organisms are able to acclimate is dictated by their phenotypic plasticity or the ability of an organism to change certain traits. Recent research in the study of acclimation capacity has focused more heavily on the evolution of phenotypic plasticity rather than acclimation responses. Scientists believe that when they understand more about how organisms evolved the capacity to acclimate, they will better understand acclimation.

Examples

Plants

Many plants, such as maple trees, irises, and tomatoes, can survive freezing temperatures if the temperature gradually drops lower and lower each night over a period of days or weeks. The same drop might kill them if it occurred suddenly. Studies have shown that tomato plants that were acclimated to higher temperature over several days were more efficient at photosynthesis at relatively high temperatures than were plants that were not allowed to acclimate.^[5]

In the orchid Phalaenopsis, phenylpropanoid enzymes are enhanced in the process of plant acclimatisation at different levels of photosynthetic photon flux.^[6]

Animals

Animals acclimate in many ways. Sheep grow very thick wool in cold, damp climates. Fish are able to adjust only gradually to changes in water temperature and quality. Tropical fish sold at pet stores are often kept in acclimatization bags until this process is complete.^{[citation needed]} Lowe & Vance (1995) were able to show that lizards acclimated to warm temperatures could maintain a higher running speed at warmer temperatures than lizards that were not acclimated to warm conditions.^[7]

Humans

The salt content of sweat and urine decreases as people acclimatize to hot conditions.^[8]

Acclimatization to high altitude continues for months or even years after initial ascent, and ultimately enables humans to survive in an environment that, without acclimatization, would kill them. Humans who migrate permanently to a higher altitude naturally acclimatize to their new environment by developing an increase in the number of red blood cells to increase the oxygen carrying capacity of the blood, in order to compensate for lower levels of oxygen in the air.^[9]^[10]

Notes

World Book encyclopedia 1989

References

^ (2009) “Acclimatisation” (n.d.) The Unabridged Hutchinson Encyclopedia RetrievedNovember 5 2009 from http://encyclopedia.farlex.com/acclimatization
^ Los, D.A.; Murata, N. (2004). "Membrane fluidity and its roles in the perception of environmental signals." Biochimica et biophysica acta-biomembranes 0666, 142–157.
^ Gatten, Robert E. Jr; Arthur C Echternautch; Mark A. Wilson (July 1988). "Acclimatization versus acclimation of activity metabolism in a lizard". Physiological Zoology 61 (4): 322–329. JSTOR 30161249.
^ Angilletta, M.J. (2009). Thermal Adaptation: A Theoretical and Empirical Synthesis. Oxford University Press, Oxford.
^ Camejo, D.; Marti, M.; Nicolas, E.; Alarcon, J.; Jimenez, A.; Sevila, F. (2007) Response of superoxide dismutase isoenzymes in tomato plants (Lycopersicon esculentum) during thermo-acclimation of the photosynthetic apparatus. Physiologia Plantarum 131, 367-377.
^ Enhancement of phenylpropanoid enzymes and lignin in Phalaenopsis orchid and their influence on plant acclimatisation at different levels of photosynthetic photon flux. Mohammad Babar Ali, Serida Khatun, Eun-Joo Hahn and Kee-Yoeup Paek, Plant Growth Regulation, 2006, Volume 49, Numbers 2-3, pages 137-146, doi:10.1007/s10725-006-9003-z
^ Lowe, C.H.; Vance, V.J. (1955) Acclimation of the critical thermal maximum of the reptile Urosaurus ornatus. Science 122, 73-74.
^ "Heat acclimatization guide". US Army. Archived from the original on 2007-07-02. Retrieved 2009-07-02.
^ Muza, SR; Fulco, CS; Cymerman, A (2004). "Altitude Acclimatization Guide.". US Army Research Inst. of Environmental Medicine Thermal and Mountain Medicine Division Technical Report (USARIEM–TN–04–05). Retrieved 2009-03-05.
^ Kenneth Baillie and Alistair Simpson. "Altitude oxygen calculator". Apex (Altitude Physiology EXpeditions). Retrieved 2006-08-10. - Altitude physiology model

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 高山病：生理学、危険因子、および一般的な予防法 high altitude illness physiology risk factors and general prevention
2. 思春期および成人における労作性熱中症：疫学、体温調節、危険因子、および診断 exertional heat illness in adolescents and adults epidemiology thermoregulation risk factors and diagnosis
3. 思春期および成人における労作性熱中症：管理および予防 exertional heat illness in adolescents and adults management and prevention
4. 急性高山病および高地脳浮腫 acute mountain sickness and high altitude cerebral edema

English Journal

Ocean cleaning stations under a changing climate: biological responses of tropical and temperate fish-cleaner shrimp to global warming.

Rosa R1, Lopes AR, Pimentel M, Faleiro F, Baptista M, Trübenbach K, Narciso L, Dionísio G, Pegado MR, Repolho T, Calado R, Diniz M.
Global change biology.Glob Chang Biol.2014 Apr 27. doi: 10.1111/gcb.12621. [Epub ahead of print]
Cleaning symbioses play an important role in the health of certain coastal marine communities. These interspecific associations often occur at specific sites (cleaning stations) where a cleaner organism (commonly a fish or shrimp) removes ectoparasites/damaged tissue from a "client" (a larger cooper
PMID 24771544

Tumor aerobic glycolysis: new insights into therapeutic strategies with targeted delivery.

Talekar M1, Boreddy SR, Singh A, Amiji M.
Expert opinion on biological therapy.Expert Opin Biol Ther.2014 Apr 25. [Epub ahead of print]
Introduction: Cancer cells acclimatize to the harsh tumor microenvironment by altering cellular metabolism in favor of aerobic glycolysis. This process provides a source of energy and also generates essential components for macromolecular biosynthesis, which enables cellular survival. As the depende
PMID 24762115

Impact of high altitude on the hepatic fatty acid oxidation and synthesis in rats.

Ni Q1, Shao Y2, Wang YZ2, Jing YH3, Zhang YC4.
Biochemical and biophysical research communications.Biochem Biophys Res Commun.2014 Apr 4;446(2):574-9. doi: 10.1016/j.bbrc.2014.03.001. Epub 2014 Mar 12.
High altitude (HA) affects energy metabolism. The impact of acute and chronic HA acclimatization on the major metabolic pathways is still controversial. In this study, we aimed to unveil the impact of HA on the key enzymes involved in the fatty acid (FA) metabolism in liver. Rats were exposed to an
PMID 24613835

Push-in Head Restraining Apparatus for Intracranial Self Stimulation Tasks in Rats.

Roh M1, Jang IS2, Lee MG1.
The Korean journal of physiology & pharmacology : official journal of the Korean Physiological Society and the Korean Society of Pharmacology.Korean J Physiol Pharmacol.2014 Apr;18(2):103-8. doi: 10.4196/kjpp.2014.18.2.103. Epub 2014 Apr 3.
Head restraining is an experimental technique that firmly secures the animal's head to a fixation apparatus for the precise control and sensing of behaviors. However, procedural and surgical difficulties and limitations have been obstructing the use of the technique in neurophysiological and behavio
PMID 24757371

Japanese Journal

A marine phytoplankton (Prymnesium parvum) up-regulates ABC transporters and several other proteins to acclimatize with Fe-limitation

Rahman M. Mamunur,Rahman M. Azizur,Maki Teruya,Nishiuchi Takumi,Asano T.,Hasegawa Hiroshi
Chemosphere (95), 213-219, 2014-01-01
Iron (Fe) is one of the vital limiting factors for phytoplankton in vast regions of the contemporary oceans, notably the high nutrient low chlorophyll regions. Therefore, it is apparent to be acquaint …
NAID 120005350316

A marine phytoplankton (Prymnesium parvum) up-regulates ABC transporters and several other proteins to acclimatize with Fe-limitation

Mamunur Rahman M.,Azizur Rahman M.,Maki Teruya,Nishiuchi Takumi,Asano Tomoya,Hasegawa Hiroshi
Chemosphere 95, 213-219, 2014-01
Iron (Fe) is one of the vital limiting factors for phytoplankton in vast regions of the contemporary oceans, notably the high nutrient low chlorophyll regions. Therefore, it is apparent to be acquaint …
NAID 120005386055

造礁サンゴの環境変化に対する順応機構と適応の可能性(地球環境変動と造礁サンゴ II,「海の研究」特集号)

井口亮,磯村尚子
海の研究 21(5), 147-158, 2012-09-15
地球的規模,地域的規模の各種の環境変化によって,サンゴ礁の基盤構成生物であるサンゴの減少が危惧されている。そのため,今後の環境変化に対して,サンゴがどのように応答できるのかを評価することが急務となっている。これまでの飼育実験において,サンゴの環境変化に対する応答を,成長率,死亡率,光合成活性など,様々なパラメーターに着目して調べた研究や総説は多く存在する。その一方で,ある環境要因の段階的変化に対し …
NAID 110009544545

深海生物飼育のための高圧研究装置開発

小山純弘
高圧力の科学と技術 = The Review of high pressure science and technology 20(4), 330-338, 2010-11-20
… The re-pressurized deep-sea organisms can acclimatize at atmospheric pressure condition for a few months after slow decompression at a rate of −0.025 MPa/h. …
NAID 10027681055