• Title/Summary/Keyword: diurnal change

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Influence of Phenobarbital on the Circadian Rhythm of Opiate Receptor in Rat Brain (백서의 뇌내 Opiate 수용체의 일중 변동에 미치는 Phenobarbital의 영향)

  • Park, Yeoung-Gul;Kim, Kee-Won;Cho, Kyu-Park
    • The Korean Journal of Pharmacology
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    • v.21 no.2
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    • pp.128-141
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    • 1985
  • To investigate the influence of phenobarbital sodium on the action of morphine and on the diurnal rhythms of both opiate receptor binding and ${\beta}-endorphin$ contents, the amount of specifically bound $(^3H)$-morphine and immunoreactive ${\beta}-endorphin$ were measured in the midbrain of phenobarbital-treated rats at 4h intervals in a day. Rats were housed and adapted to a controlled cycle of either 12 h light-12 h dark or 24 h constant dark. After 3 weeks of adaptation, 0.5 ml of physiological saline or phenobarbital sodium (20mg/kg/day, i.p.) were administered twice a day for 2 weeks. Highly significant diurnal rhythms of opiate receptor binding and ${\beta}-endorphin$ were present in rat midbrain. In control group, the peak of maximum $(^3H)$-morphine binding was observed at 22:00 h, whereas the peak of ${\beta}-endorphin$ content was found at 06:00 h. Even in the absence of time cues these diurnal rhythms persisted, but they were highly modified with respect to the wave form as well as differences in the timing of peak and nadir. In the phenobarbital-treated group, these diurnal rhythms were also modified in shape, phase and amplitude, as well as in timing of peak and nadir. In this group, 24 h mean of opiate receptor binding was significantly decreased, while the 24 h mean level of ${\beta}-endorphin$ content was highly increased. However, Kd values in all experimental groups did not change. This indicates that differences in binding were not due to changes in the affinity, but in the number of binding sites. Statistical analysis of regression line indicates that changes of receptor binding were closely correlated with the changes of ${\beta}-endorphin$ content. These results suggest that phenobarbital may influence the action of morphine by changing the number of opiate receptors and that the modification of diurnal rhythm of opiate receptor by the agent is possibly due to changes of ${\beta}-endorphin$ content.

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The Suitability of European Designed Wind Turbines for the East Asian Market

  • Brown, G.R.D.;Barthelmie, R.J.;Kim, Hyun-Goo
    • Journal of Environmental Science International
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    • v.18 no.8
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    • pp.825-831
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    • 2009
  • A first step review is completed on the suitability of European designed wind turbines in an East Asia climate. Six parameters are chosen for detailed analysis of proper meteorological measures from flat, hilly, forested, coastal and offshore sites in West Europe and East Asia: mean wind speed, 10 minute mean wind speed distribution, turbulence intensity, wind shear, 3 second extreme wind speed and 10 minute direction change. All six parameters are assessed with a view for contrast with the wind turbine design standard IEC61400. The diurnal and seasonal variation, average and extreme values of each parameter are calculated where appropriate. Industry standard software and analysis techniques have been employed to assess the applicability of existing wind turbine design standards and design guidelines for the East Asian market.

Characteristics of Mesoscale Circulation with the Detailed Building Distribution in Busan Metropolitan Area (부산지역 빌딩 분포 상세화에 따른 중규모 순환 특성)

  • Son, Jeong-Ock;Lee, Hwa-Woon;Lee, Soon-Hwan
    • Journal of Environmental Science International
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    • v.21 no.2
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    • pp.203-215
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    • 2012
  • In order to clarify the impacts of thermal difference in atmospheric boundary layer due to the different sophistication of building information in Busan metropolitan areas, several numerical simulations were carried out. ACM (Albedo Calculation Model) and WRF (Weather Research and Forecasting) was applied for estimating albedo and meteorological elements in urban area, respectively. In comparison with coarse aggregated and small buildings, diurnal variation of albedo is highly frequent and its total value tend to be smaller in densely aggregated and tall buildings. Estimated TKE and sensible heat flux with sophisticatedly urban building parameterization is more resonable and valid values are mainly induced by urban building sophistication. The simulation results suggest that decreased albedo and increased roughness due to skyscraper plays an important role in the result of thermal change in atmospheric boundary layer.

Photochemical Analysis of Ozone Episodes in the Metropolitan Area of Seoul During the Summer 2004 (2004년 여름 서울에서 발생한 고농도 오존 사례의 광화학적 분석)

  • Shon, Zang-Ho
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.3
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    • pp.361-371
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    • 2006
  • This study examines ozone episodes occurred during the intensive sampling periods (Jun. 1-30, 2004) in the air of Seoul metropolitan area. During that period, there were 8 events (or days) in which 1 hr averaged ozone concentrations were greater than 100 ppbv. The photochemical analysis of ozone chemistry (i.e., budget and formation and destruction strengths of ozone) was carried out using a photochemical box model. Peaks in diurnal ozone variations during ozone episode periods occurred were concurrent with the sudden change of the slope of $NO_{2}/NO$ ratio, suggesting significant correlation with photochemical reactivity. In addition, the ozone peaks were concurrent with high concentrations of ozone precursors, peroxy radicals of $HO_{2},\;CH_{3}O_{2},\;and\;RO_{2}$. High ozone levels during the ozone episodes are likely to be affected by ozone destruction rate.

Past and Future Temperature and Precipitation Changes over Korea using MM5 Model

  • Oh, Jai-Ho;Min, Young-Mi;Kim, Tae-Kook;Woo, Su-Min;Kwon, Won-Tae;Baek, Hee-Jeong
    • Proceedings of the Korean Quaternary Association Conference
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    • 2004.06a
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    • pp.29-29
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    • 2004
  • Long term observational analysis by climatologists has confirmedthat the global warming is no longer a topic of debate among scientists andpolicy makers. According to the report of IPCC-2001 (Intergovernmental Panelon Climate Change), the global mean surface air temperature is increasinggradually. The reported increase of mean temperature is by 0.6 degree in the end of twentieth century. This could represent severe threat for propertylosses especially due to increase in the number of extreme weather arising out of global warming. period of model integration from 2001 to 2100 using output of ECHAM4/HOPE-G of Max Planet Institute of Meteorology (MPI) for IPCC SRES (Special Report on Emission Scenarios). The main results of this study indicate increase of surface air temperature by 6.20C and precipitation by 2.6% over Korea in the end of 21st century. Simulation results also show that there is increase in daily maximum and minimum temperatures while decrease in diurnal temperature range (DTR). DTR changes are diminished mainly due to relatively rapid increase of daily minimum temperature than that of daily maximumtemperature. It has been observed that increase in precipitation amount anddecrease in the number of rainy days lead to increase of pre precipitationintensity.

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Changes in the Earth's Spin Rotation due to the Atmospheric Effects and Reduction in Glaciers

  • Na, Sung-Ho;Cho, Jungho;Kim, Tu-Hwan;Seo, Kiweon;Youm, Kookhyoun;Yoo, Sung-Moon;Choi, Byungkyu;Yoon, Hasu
    • Journal of Astronomy and Space Sciences
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    • v.33 no.4
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    • pp.295-304
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    • 2016
  • The atmosphere strongly affects the Earth's spin rotation in wide range of timescale from daily to annual. Its dominant role in the seasonal perturbations of both the pole position and spinning rate of the Earth is once again confirmed by a comparison of two recent data sets; i) the Earth orientation parameter and ii) the global atmospheric state. The atmospheric semi-diurnal tide has been known to be a source of the Earth's spin acceleration, and its magnitude is re-estimated by using an enhanced formulation and an up-dated empirical atmospheric S2 tide model. During the last twenty years, an unusual eastward drift of the Earth's pole has been observed. The change in the Earth's inertia tensor due to glacier mass redistribution is directly assessed, and the recent eastward movement of the pole is ascribed to this change. Furthermore, the associated changes in the length of day and UT1 are estimated.

Analysis of Environmental Factors for Full Bloom Stage and Fruit Growth in Peach (복숭아 품종의 만개기와 과실 생장에 영향을 미치는 환경요인 분석)

  • Han, Hyun Hee;Han, Jeom Hwa;Jeong, Jae Hoon;Ryu, Su Hyun;Kwan, Yong Hee
    • Journal of Climate Change Research
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    • v.7 no.4
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    • pp.493-498
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    • 2016
  • This study was conducted to investigate the effect of environment factors on full bloom stage and fruit width in four peach cultivars. The average temperature in March was the main factor to determine the date of full bloom in 'Kurakatawase'($-0.6871^*$) and 'Changhowon Hwangdo'($-0.5270^*$). The fruit growth curve after 35 days from full bloom was the double sigmoid shape in 'Changhowon Hwangdo' cultivar. Environmental factors affecting fruit width were mean diurnal range(BIO2) and temperature annual range(BIO 7) in 'Kurakatawase', growing degree days(GDD) after 30 days from full bloom and July precipitation in 'Yumyeong', and annual mean temperature(BIO1), BIO7, and July precipitation in 'Kawanakajima Hakuto'. Of these, major environmental factors affecting fruit width in more than two cultivars were BIO7 and July precipitation.

Effects of Estuarine Dam on Fish Assemblage in Danghang Bay of the South Sea, Korea (남해 당항만 하구둑 유무에 따른 어류상 비교)

  • Park, Jun-Su;Gwak, Woo-Seok
    • Korean Journal of Ichthyology
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    • v.31 no.2
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    • pp.83-89
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    • 2019
  • The effect of estuarine dams on fish assembladge in Danghang Bay of Goseong, Korea was determined using monthly samples collected by a beam trawl and a cast net at the natural estuaries and damed estuary from September 2011 to August 2012. In the natural estuaries without dam, salinity was relatively high showing a large diurnal change. Estuarine fishes such as striped sandgoby, Acentrogobius pflaumii and yellowfin goby, Acanthogobius flavimanus, were dominantly caught in the sea side water. In the dammed estuary, freshwater species such as pale chub, Zacco platypus and triden goby, Tridentiger brevispinis were dominanlty caught. The dam in the Danghang estuary have significant effects on the fish assemblage through aquatic environmental change such as salinity.

Sea Level Change due to Nonlinear Tides in Coastal Region (연안해역에서 비선형 조석으로 인한 해수면 변화)

  • Jung, Tae Sung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.5
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    • pp.228-238
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    • 2017
  • In coastal region, tidal harmonic constants of semi-diurnal tides and nonlinear tides were collected. The observed tide data of KHOA were analyzed by a tide harmonic analysis method. In the southwestern coasts and Han river estuary, nonlinear tides are clearly generated. The generation of tide non-linearity and tide asymmetry is closely related with tide form factor in Korean coastal zone. Tide non-linearity and asymmetry in Mokpo harbour have increased by a series of coastal development projects. The increase has caused rise of high water level and drop of low water level, and increase of tidal range. In Kunsan Outport, tidal range has been declined due to inter-annual change of nonlinear tides after completion of Samangeum sea-dyke.

Characterization of Photosynthetic Rates by Tomato Leaf Position (토마토 엽위별 광합성 특성 분석)

  • Kim, Sung Eun;Lee, Moon Young;Kim, Young Shik
    • Horticultural Science & Technology
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    • v.31 no.2
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    • pp.146-152
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    • 2013
  • The photosynthetic rates according to leaf positions in tomato plants were investigated in relation to leaf age and flowering rate. In the experiment investigating the diurnal change of photosynthetic rates, three leaves below the 4th cluster was checked every hour from 2 hours before sunrise and 3 hours after sunset. It was checked twice with the replication of 3 plants. The photosynthetic rate increased sharply for 1 hour right after sunrise and remained steady until 2 hours before sunset. This trend can be applied to determine the irrigation schedule. In the experiment investigating the photosynthetic rates according to leaf positions, it three leaves below each clusters from 1st to 4th cluster were checked. Flowering rate was also investigated. The photosynthetic rates showed a decreasing tendency steadily after flowers bloomed fully, regardless of the leaf position. It seems to be because the leaves below the cluster with fully-bloom flowers lost their activities. This result suggests the flowering rate or the position of flower has deep relation with the photosynthetic rates of the concerned leaves. From the results the leaves under flowering cluster may be the good part to investigate the photosynthetic rate to evaluate the crop's activity, even the photosynthetic rates are different according to the position of clusters.