• Title/Summary/Keyword: acclimatization

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Heat Acclimatization in Hot Summer for Ten Weeks Suppress the Sensitivity of Sweating in Response to Iontophoretically-administered Acetylcholine

  • Lee, Jeong-Beom
    • The Korean Journal of Physiology and Pharmacology
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    • v.12 no.6
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    • pp.349-355
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    • 2008
  • To determine the peripheral mechanisms involved in thermal sweating during the hot summers in July before acclimatization and after acclimatization in September, we evaluated the sweating response of healthy subjects (n=10) to acetylcholine (ACh), a primary neurotransmitter involved in peripheral sudomotor sensitivity. The quantitative sudomotor axon reflex test (QSART) measures sympathetic C fiber function after iontophoresed ACh evokes a measurable reliable sweat response. The QSART, at 2 mA for 5 min with 10% ACh, was applied to determine the directly activated (DIR) and axon reflex-mediated (AXR) sweating responses during ACh iontophoresis. The AXR sweat onset-time by the axon reflex was $1.50{\pm}0.32$ min and $1.84{\pm}0.46$ min before acclimatization in July and after acclimatization in September, respectively (p<0.01). The sweat volume of the AXR(l) [during 5 min 10% iontophoresis] by the axon reflex was $1.45{\pm}0.53\;mg/cm^2$ and $0.98{\pm}0.24\;mg/cm^2$ before acclimatization in July and after acclimatization in September, respectively (p<0.001). The sweat volume of the AXR(2) [during 5 min post-iontophoresis] by the axon reflex was $2.06{\pm}0.24\;mg/cm^2$ and $1.39{\pm}0.32\;mg/cm^2$ before and after acclimatization in July and September, respectively (p<0.001). The sweat volume of the DIR was $5.88{\pm}1.33\;mg/cm^2$ and $4.98{\pm}0.94\;mg/cm^2$ before and after acclimatization in July and September, respectively (p<0.01). These findings suggest that lower peripheral sudomotor responses of the ACh receptors are indicative of a blunted sympathetic nerve response to ACh during exposure to hot summer weather conditions.

Effects of Acclimatization to Different Light Colors on the Growth of Petunia (Petunia hybrida) in a Greenhouse (조직배양 페튜니아의 순화과정에서 광질에 따른 생장반응 특성)

  • Young-Sun Kim;Geung-Joo Lee
    • Korean Journal of Environmental Agriculture
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    • v.42 no.1
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    • pp.14-20
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    • 2023
  • Light is an important factor that influences the growth and development of flowering plants. The present study investigated the effects of in vitro acclimatization to different light colors (white light (WL; control), blue light (BL; 447 nm), green light (GL; 519 nm), and red light (RL; 667 nm)) on the growth of petunia (Petunia hybrida) and of hardening cultivation of plant transferred form in vitro to a greenhouse under sunlight. Compared to the control, the shoot length and leaf width of Petunia increased by 42% and 11.7%, respectively, after acclimatization to BL and the shoot growth increased by 29.3% after acclimatization to RL. The chlorophyll and carotenoid contents after acclimatization to BL and GL were 16.7% and 11.3% higher, respectively, and 14.4% and 11.9% higher, respectively, than those in the control. During greenhouse cultivation, the shoot length increased by 16.7% and 11.3%, respectively, after acclimatization to BL and RL, respectively, and the leaf length and leaf width increased by 14.4% and 11.9%, respectively, after acclimatization to GL. While dry weight of root of GL and BL was not significant difference in vitro, increased by 59.0% and 22.9% ex vitro than that of WL. Thus, acclimatization to BL increased the shoot growth and leaf chlorophyll contents, and acclimatization to GL and RL enhanced shoot and root growth, in petunia.

A Case Study on the Acclimatization's Housing for Environmental Load Reduction (환경부하 저감을 위한 기후순응주거 사례연구)

  • Cho, Sung-Woo;Oh, Se-Gyu
    • Journal of the Korean housing association
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    • v.24 no.6
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    • pp.69-79
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    • 2013
  • The concept of sustainable development to preserve natural environment through economy in resources and energy is gradually distinguished since environmental problems as a series of air pollution and global warming take place now. Building occupies more than 1/3 of energy consumption in the whole world. Energy consumption of buildings caused a quick increase in the amount of energy use by air conditioning, which has a lot of effects on exhaustion of fossil energy as well as an increase in environmental load. Therefore, this research intends to suggest characteristics and direction for the designing of acclimatization's housing through the case study on acclimatization's housing. Acclimatization's housing is designed to reduce building load from the designing stage unlike green home or low-energy apartment. Also, factors which are commonly applied to acclimatization's housing are applied complexly by design strategic factors of Heating, Cooling and Lighting. The applied design factors make effects mutually and complexly. In addition, design strategy showed different priority by designing direction.

A Study on acclimatization culture of the tissue cultured seedings in Zantedschia spp. (유색칼라 기내배양묘의 순화재배에 관한 연구)

  • Park, N.B.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.5 no.1
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    • pp.20-27
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    • 2003
  • This experiment was carried out to develop an acclimatization system of tissue cultured seedling in Zantedeschia spp. There was not different in percentage of leaf emergence by the media compost of acclimatization but tuber was enlarged in sand(50%)+peatmoss(50%) treatment after 6 months growth. The optimum time for the acclimatizantion of Zantedeschia spp. was from the 20th of March to 20th of April. During this time, rate of acclimatization reached over 90 percentage. However on the 20th of august, acclimatization was low to 64-70.4 percentage. Size of tuber was enlarged in planting on the 20th of March. The weight of tuber was better in 10×10cm density of planting than others.

Rooting and Acclimatization of Shoots Harvested from Bioreactor Culture in Rehmania glutinosa (생체반응기에서 수확한 지황 신초의 발근과 순화)

  • Koh, Eun-Jung;Chae, Young-Am
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.3
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    • pp.186-188
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    • 2002
  • This experiment was carried out to know the effect of media and agar concentrations, aeration and growth regulators on rooting and acclimatization of the shoots harvested from bioreactor culture in Rehmannia glutinosa. Half MS media with 1.2% agar improved rooting and acclimatization of shoots. Shoots were effectively acclimatized and rooted well in case of aeration by using membrane filtered vessels. Shoots acclimatized in vessel with membrane Inter were healthier and had higher ex vitro survival rate than those without membrane Inter on plug tray. Addition of paclobutrazol 0.3-0.4 mg/L, to acclimatization media enhanced shoots growth and root development.

Effect of Cold Acclimatization Training on Body Composition (추위 훈련이 신체 조성에 미치는 영향 -체중, 체지방량, 골격근량을 중심으로-)

  • Park, Joo-Hee;Choi, Jeong-Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.7
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    • pp.713-720
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    • 2011
  • This study investigated the effect of cold acclimatization training on body composition including weight, fat mass, and muscle mass with 10 subjects (5 males and 5 females). During the 3-week acclimatization training program, they visited an artificial climate chamber ($15^{\circ}C$) 15 times and were exposed to cold environment with light clothing for 2 hours. Body composition was measured before and after cold training using bioelectric impedance analysis that was later compared by a paired t-test. In the process of thermoregulation, muscle contraction was accompanied by increased substrate metabolism for rising heat production. After cold training, the muscle mass increased and fat mass decreased significantly (p<.1, p<.05), subsequently the body composition changed. It was found that cold acclimatization training could be used as a treatment for obesity. It was suggested that further investigation on the long term effects of mild cold exposure using clothing and its potential applicability as an obesity treatment.

A comparison of photosynthesis measurements by O2 evolution, 14C assimilation, and variable chlorophyll fluorescence during light acclimatization of the diatom Coscinodiscus granii

  • Trampe, Erik;Hansen, Per Juel;Kuhl, Michael
    • ALGAE
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    • v.30 no.2
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    • pp.103-119
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    • 2015
  • Photosynthetic rates of the large centric diatom Coscinodiscus granii were measured by means of multicolor variable chlorophyll fluorescence imaging, single cell $^{14}C$ assimilation, and optical $O_2$ sensor measurements during light acclimatization of cultures grown at five different irradiances: 50, 150, 235, 332, and $450{\mu}mol$ photons $m^{-2}\;s^{-1}$. Photo-acclimatization was evident from changes of cellular chlorophyll a content, growth rates, and light response curves. Each of the applied methods evaluates different parts and reactions in the photosynthetic apparatus, which makes a direct quantitative comparison of rates difficult, although a different degree of correlation were found between all three methods. However, when used in combination, they provide information about the internal relationship of photosynthetic pathways as well as the variation in photosynthetic capacity between individual cells within a single algal culture.

The Effect of Light and Darkness on Acclimatization of Laying Hens

  • Izzeldin, B.;Kassim, H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.5
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    • pp.694-697
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    • 2000
  • Laying hens kept in different light and dark periods of the day at high ambient temperature of maximum $35^{\circ}C$ were challenged to $38.5{\pm}0.5^{\circ}C$ acute heat 3 hours daily for 7 consecutive days. They were found to have a significant (p<0.01) acclimatization response (rectal temperature) to heat stress during the dark period compared to those exposed to the same temperature during the light period. The blood pH was not significantly different. The partial pressure of carbon dioxide ($PCO_2$) was significantly high (p<0.01) except in day 4. Similarly the blood bicarbonate ($HCO_3$) concentration was significantly high (p<0.05) except day three and day four. Acute heat exposure in the first day increased the body temperature in both groups (Light and Dark) reaching $44^{\circ}C$, followed by gradual reduction in body temperature. The dark treated birds showed rapid reduction in body temperature ($42.88^{\circ}C$) and adaptation to high temperature during days 2-4 but that this was lost to some extent in days 6-8. However this was not obvious in the light treated birds. It is concluded that darkness reduce hyperthermia and enhance acclimatization responses during acute heat stress.

Characteristics of Heat Acclimatization for Major Korean Cities (한국 주요도시의 폭염에 대한 기후 순응도 특성)

  • Kim, Jiyoung;Lee, Dae-Geun;Kysely, Jan
    • Atmosphere
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    • v.19 no.4
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    • pp.309-318
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    • 2009
  • Vulnerability to heat was examined for populations of 6 major cities in South Korea (Seoul, Incheon, Daejeon, Gwangju, Daegu, and Busan). Daily excess mortality and maximum temperature from 1991 to 2005 were employed in this study. The results show that the standardized mortality increase associated with a $1^{\circ}C$ increase in daily maximum temperature above the city-specific threshold explains the heat acclimatization effect better than the threshold temperature itself. The estimated increase in mortality (standardized per 10 million population) associated with a $1^{\circ}C$ increase in temperature above the threshold is 4.8 in Incheon, 4.7 in Seoul, 4.3 in Daejeon, 2.8 in Gwangju, 2.4 in Daegu, and 1.5 in Busan, well reflecting the latitudinal locations and local climates of each city. Climate models project more frequent, more intense, and longer lasting heat waves in most land areas in both hemispheres in the 21st century under increasing greenhouse gas concentrations. In order to mitigate the adverse human health impacts due to excess heat, more detailed characteristics of acclimatization to heat need to be understood and quantified.

Improvement of ex vitro acclimatization of mulberry plantlets by supplement of abscisic acid to the last subculture medium

  • Huh, Yoon Sun;Lee, Joung Kwan;Nam, Sang Young
    • Journal of Plant Biotechnology
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    • v.44 no.4
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    • pp.431-437
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    • 2017
  • Mulberry (Morus sp.) of the family Moraceae is very economically important in Asian countries including Korea, because its leaf and fruit have been commercially used in sericulture and horticultural industries. Therefore it is necessary to develop the optimal production system for rapid and cost-effective propagation of mulberry. Our studies focused on establishing an acclimatization method for the successful plantlet production of new cultivar 'Cheongsu' which was transferred ex vitro after in vitro culture. In particular, effect of abscisic acid (ABA) addition into the last subculture medium on plantlet response to subsequent ex vitro transfer and its growth was investigated. During acclimatization, stomatal conductance and transpiration rate of ABA-pretreated plantlets were significantly lower than those of non-treated plantlets. Net photosynthetic rate of ABA-pretreated plantlets decreased after ex vitro transfer but increased after 14 days, and it was mostly higher than that of non-treated plantlets. Moreover, relative water content as well as chlorophyll contents and its ratio were also higher in ABA-pretreated plantlets. On the other hand, proline was considerably higher than in control plantlets. After 1 month of ex vitro transfer, survival rate of ABA-pretreated plantlets was 85.6%, which increased by 29.1% in comparison with control (56.5%). More vigorous growth was also observed in ABA-pretreated plantlets. From these results, it was found that application of ABA to the last subculture medium could improve acclimatization and promote survival of mulberry plantlets after ex vitro transfer, inducing water stress tolerance and alleviating abiotic stresses.