• Title/Summary/Keyword: N and P limitation

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Ureide Distribution in Nitrogen Fixing Soybean Plant under External Phosphorus Limitation (인산결핍 조건하에서 질소고정식물체내의 Ureide 분배)

  • Sa, Tong-Min
    • Applied Biological Chemistry
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    • v.40 no.3
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    • pp.232-237
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    • 1997
  • Soybean plants inoculated Bradrhizobium japonicum MN 110 were grown in outdoor perlite pots with nitrogen free nutrient solution containing 1.0 mM-P(control) and 0.05 mM-P(stress) and harvested at 28, 35, 42 and 49 days after transplanting (DAT) to examine the effect of phosphorus deficiency on ureide concentration of and distribution to diffrent plant organ in nitrogen fixing soybean plant during the vegetative growth. Total dry mass of control plants increased 8.9 fold and that of phosphorus deficient plant increased 2.7 fold during the experimental period. Phosphorus deficiency reduced total phosphorus and nitrogen accumulation by 80%,40% respectively, at 28 DAT and 93%, 84%, respectively, at 49 DAT. Nitrogen concentration was reduced by phosphorus deficiency in all tissues with leaf and stem tissues affected to a greater degree than nodule and root tissues at every sampling date. Phosphorus deficiency significantly reduced soluble reduced-N and ureide-N concentration in leaf and stem but did not affect those in root. The proportion of soluble reduced-N in leaf was reduced from 60% to 50% but increased from 10% to 20% in the roots. The proportion of ureide-N in leaf of control plants was higher than that in phosphorus deficient plants, whereas, roots of phosphorus deficient plants contained a higher propotion of ureide-N than those of control plants. These indicated that phosphorus deficiency not only inhibit nitrogen fixation of nodules but also restrict the translocation of fixed nitrogen out of the root system into the xylem.(Received April 4, 1997; accepted May 2, 1997)

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RENAL REGULATION OF UREA EXCRETION DURING UREA INFUSION IN ACUTE HEAT EXPOSED BUFFALOES

  • Chaiyabutr, N.;Buranakarl, C.;Loypetjra, P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.1
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    • pp.81-90
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    • 1992
  • Five buffaloes kept in normal ambient temperature ($30^{\circ}C$) showed no significant changes in the heart rate, respiratory rate, packed cell volume, plasma constituents and renal hemodymics during intravenous infusion of urea for 4 h. The rate of urine flow, fractional urea excretion, urinary potassium excretion and osmolar clearance significantly decreased while the renal urea reabsorption markedly increased during urea infusion. The decrease of fractional potassium excretion was concomitant with the reduction of the rate of urine flow and urine pH. In animals exposed to heat ($40^{\circ}C$) the rectal temperature heart rate and respiratory rate significantly increased while no significant changes in GFR and ERPF were observed. An intravenous infusion of urea in heat exposed animals caused the reduction of the rate of urine flow with no changes in renal urea reabsorption, urine pH and fractional electrolyte excretions. During heat exposure, there were marked increases in concentrations of total plasma protein and plasma creatinine whereas plasma inorganic phosphorus concentration significantly decreased. It is concluded that an increase in renal urea reabsorption during urea infusion in buffaloes kept in normal ambient temperature depends on the rate of urine flow which affect by an osmotic diuretic effect of electrolytes. The limitation of renal urea reabsorption in heat stressed animals would be attributed to an increases in either plasma pool size of nitrogenous substance or body metabolism.

Targeted Gene Disruption and Functional Complementation of Cytochrome P450 Hydroyxlase Involved in Cyclosporin A Hydroxylation in Sebekia benihana

  • Lee, Mi-Jin;Han, Kyu-Boem;Kim, Eung-Soo
    • Journal of Microbiology and Biotechnology
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    • v.21 no.1
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    • pp.14-19
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    • 2011
  • A cyclic undecapeptide-family natural product, cyclosporin A (CyA), which is one of the most valuable immunosuppressive drugs, is produced nonribosomally by a multifunctional cyclosporin synthetase enzyme complex in a filamentous fungal strain named Tolypocladium niveum. Previously, structural modifications of cyclosporins such as a regionspecific hydroxylation at the $4^{th}$ N-methyl leucine in a rare actinomycetes called Sebekia benihana were reported to lead to dramatic changes in their bioactive spectra. However, the reason behind this change could not be determined since a system to genetically manipulate S. benihana has not yet been developed. To address this limitation, in this study, we utilized the most commonly practiced gene manipulation techniques including conjugation-based foreign gene transfer-and-expression as well as targeted gene disruption to genetically manipulate S. benihana. Using these optimized genetic manipulation systems, a putative cytochrome P450 hydroxylase (CYP) gene named CYP506, which is involved in CyA hydroxylation in S. benihana, was specifically disrupted and genetically complemented. The S. benihana${\Delta}$CYP506 exhibited a significantly reduced CyA hydroxylation yield as well as considerable yield restoration by functional complementation of the S. benihana CYP506 gene, suggesting that the genetically manipulated S. benihana CYP mutant strains may serve as a more efficient bioconversion host for various valuable metabolites including CyA.

A Study on the Removal of Ammonia by Using Peat Biofilter (미생물 활성토탄을 이용한 암모니아 제거에 관한 연구)

  • Choung, Youn Kyoo;Ahn, Jun Seong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.3
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    • pp.655-668
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    • 1994
  • Conventional deodorization filters using soil and compost reach the capacity limitation of deodorization in short period, because its removal mechanism primarily depends on adsorption. Therefore, in this study the experiment was performed on the removal of ammonia which is a strong inorganic malodor, frequently emitted from night soil treatment plants and sewage treatment plants, by seeding activated sludges on the bio-peat containing higher organic contents, water conservation capacity, permeability and lower pressure drop. As a result, in raw peat filter natural ammonia outlet was observed in consequence of pH increase resulted from ammonia ionizing in liquid phase. Ammonia removal mechanism primarily depended on the adsorption onto the anion colloidal substances in peat. In peat bio-filter, theoretical ammonium salts ratio was higher than that of raw peat, resulted from slight pH increase by microorganism activity, however, the experimetal value of ammonia-nitrogen accumulated in bio-peat was lower than that of raw peat because of nitrification by nitrifying bacteria. In the initial reaction period, adsorption was predominant in the ammonia removal mechanism, but nitrification was conspicuous after the middle period. Mass balance of nitrogen was established using experimental data of input $NH_3$ loading, output $NH_3$ loading, $NH_4{^+}$-N, $NO_x$-N, and Org-N. The critical time of unsteady state, which is the maximum activating point of microorganism in bio-filter, was determined using experimental data, and the ammonia adsorption curve was computed using regression analysis. On the basis of the results obtained by above analysis, the delay days for the saturation of adsoption capacity in peat bio-filter was calculated.

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Temporal Dynamics of Water Quality in Junam Reservoir, as a Nest of Migratory Birds (철새도래지인 주남저수지의 계절적 수질변동)

  • Lee, Eui-Haeng;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.42 no.1
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    • pp.9-18
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    • 2009
  • The objectives of this study were to evaluate seasonal and interannual variations of water quality and nutrient input (N, P) in Junam Reservoir, a nesting waterbody of migratory birds, over 10 years during 1998$\sim$2007 along with dynamic relations of trophic parameters using empirical models. Concentrations of COD averaged 7.8 mg $L^{-1}$ during the study, while TN and TP were $1.4\;mg\;L^{-1}$ and $83{\mu}g\;L^{-1}$, respectively, indicating an eutrophic-hypereutrophic state. Values of monthly COD had strong positive relations (r=0.669, p<0.001) with conductivity, indicating that summer rainfall resulted in an ionic dilution of the reservoir water by rainwater and contributed better water quality. One-way ANOVA tests showed significant differences (F=$5.2{\sim}12.9$, p<0.05) in TN and TP between the before and after the bird migration. In other words, nutrient levels were greater in the absence of migratory birds than in the presence of the migratory birds, suggesting a no-effect on nutrient inputs by the birds. Also, one-way ANOVA indicated no significant differences (F=$0.37{\sim}0.48$, p>0.05) in $NO_{3^-}N$ and $NH_{3^-}N$ between the before and after the birds migration. Linear empirical models using trophic parameters showed that algal biomass as CHL, had significant low correlations with TN ($R^2$=0.143, p<0.001, n=119) and TP ($R^2$=0.192, p<0.001, n=119). These results suggest that influences of nutrients on the CHL were evident, but the effect was weak. This fact was supported by analysis of Trophic State Index Deviation (TSID). Over 70% in the observed values of "TSI (CHL)-TSI (SD)" and "TSI (CHL)-TSI (TP)" were less than zero, suggesting a light limitation on the CHL by inorganic suspended solids.

The Effect of Qigong Exercise on SF-36 and Psychological Factors of Middle-aged Obese (기공 운동이 비만인의 건강관련 삶의 질(SF-36)과 심리적 요인에 미치는 영향)

  • So, Wi-Young;Seo, Han-Kyo;Choi, Dai-Hyuk;Shin, Hyun-Jung;Cho, Eun-Hyo;Yoo, Byoung-Wook;Jun, Tae-Won
    • 한국노년학
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    • v.30 no.1
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    • pp.21-30
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    • 2010
  • Obese people experience dissatisfaction of body, depression, anxiety, and emotional disturbance by social prejudice and discrimination, further they represent decline of health-related quality of life. Exercise therapy is recommended as one of the positive treatments to improve the emotional pain of obese people. This study is to provide guideline of exercise prescription for obese people by investigating the effects of qigong exercise on psychological factors such as health-related quality of life (SF-36), self-efficiency, depression, anxiety, and fatigue in obese people. The subjects of this study were 50~60s adults participated in Golden-Wellbeing program at S university in G gu of S city and were devided into exercise (N=17) and control (N=16) group. Qigong exercise was performed twice per week for 12 weeks and SF-36, self-efficiency, depression, anxiety, and fatigue were measured before and after 12 weeks of exercise. In the 8 items of SF-36 before and after 12 weeks of qi-gong exercise, there was no significance in role limitation-emotional (F=0.187, p=0.668), mental health (F=2.043, p=0.163) between groups, but there was significance in physical functioning (F=15.151, p<0.001), role limitation-physical (F=18.278, p<0.001), social functioning (F=4.957, p=0.033), vitality (F=11.485, p=0.002), bodily pain (F=6.623, p=0.015), and general health (F=4.498, p=0.042) between groups. Also, anxiety (F=0.631, p=0.433) was not significant, whereas self-efficiency (F=6.124, p=0.019), depression (F=5.109, p=0.031), fatigue (F=7.998, p=0.008) was significant between groups. Even though qigong is slow motion and low intensity of exercise, it was found that qi-gong has exercise effect which induces mental and psychological improvement through this study.

Effects of CaCl2 on Gas Exchange and Stomatal Responses in the Leaves of Prunus serrulata (염화칼슘이 벚나무 잎의 가스교환 및 기공반응에 미치는 영향)

  • Je, Sun Mi;Kim, Sun Hee
    • Journal of Korean Society of Forest Science
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    • v.105 no.3
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    • pp.303-308
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    • 2016
  • To investigate the effect of calcium chloride ($CaCl_2$) using for deicing salts in winter on gas exchange and stomatal responses of 3-year-old Prunus serrulata, we treated twice (1 L) $CaCl_2$ solution (0.5%, 1.0% and 3.0%) in the root zone before leaf unfolding. Stomatal conductance ($g_s$), photosynthetic rate ($P_n$), transpiration rate ($T_r$) and water use efficiency (WUE) in the leaves of P. serrulata were decreased with increasing of $CaCl_2$ concentration. Even though stomatal conductance and photosynthetic rate were reduced by $CaCl_2$, intercellular $CO_2$ concentration ($C_i$) in $CaCl_2$ treatments has similar or higher values compared with control. These results suggest that non-stomatal limitation as well as stomatal limitation induced the reduction of photosynthetic rate together. On the other hands, treatment of $CaCl_2$ before leaf unfolding also affected leaf morphology traits. We proposed that reductions of stomatal length and leaf size and high pore density with increasing salinity is adaptative mechanism to reduce the water loss in plant.

Electrical Characteristics of SRAM Cell with Stacked Single Crystal Silicon TFT Cell (Stacked Single Crystal Silicon TFT Cell의 적용에 의한 SRAM 셀의 전기적인 특성에 관한 연구)

  • Kang, Ey-Goo;Kim, Jin-Ho;Yu, Jang-Woo;Kim, Chang-Hun;Sung, Man-Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.4
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    • pp.314-321
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    • 2006
  • There have been great demands for higher density SRAM in all area of SRAM applications, such as mobile, network, cache, and embedded applications. Therefore, aggressive shrinkage of 6 T Full CMOS SRAM had been continued as the technology advances. However, conventional 6 T Full CMOS SRAM has a basic limitation in the cell size because it needs 6 transistors on a silicon substrate compared to 1 transistor in a DRAM cell. The typical cell area of 6 T Full CMOS SRAM is $70{\sim}90\;F^2$, which is too large compared to $8{\sim}9\;F^2$ of DRAM cell. With 80 nm design rule using 193 nm ArF lithography, the maximum density is 72 Mbits at the most. Therefore, pseudo SRAM or 1 T SRAM, whose memory cell is the same as DRAM cell, is being adopted for the solution of the high density SRAM applications more than 64 M bits. However, the refresh time limits not only the maximum operation temperature but also nearly all critical electrical characteristics of the products such as stand_by current and random access time. In order to overcome both the size penalty of the conventional 6 T Full CMOS SRAM cell and the poor characteristics of the TFT load cell, we have developed S3 cell. The Load pMOS and the Pass nMOS on ILD have nearly single crystal silicon channel according to the TEM and electron diffraction pattern analysis. In this study, we present $S^3$ SRAM cell technology with 100 nm design rule in further detail, including the process integration and the basic characteristics of stacked single crystal silicon TFT.

Output Property of Ge-Thermopile Sensor (Ge계 열전센서의 출력특성)

  • Park, Su-Dong;Kim, Bong-Seo;Oh, Min-Wook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.265-266
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    • 2006
  • It was well known that thermopile was quiet a competent sensor using to probe the temperature of "hot point" where the temperature can be off the temperature-limitation for normal operation of the main electrical power equipment. In the present work, we aimed for developing new Ge-thermopile materials which can be using a non-contact temperature sensors at various hot-point of the power equipment and evaluation of its output property. As a results of the present works, a new thermopile which were composed Ga-poded p-type and Sb-doped n-type in Ge-semiconductor were designed and manufactured by MBE(Molecular Beam Epitaxy) process and showed superior sensitivity at room temperature.

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The Electrical Characteristics of SRAM Cell with Stacked Single Crystal Silicon TFT Cell (단결정 실리콘 TFT Cell의 적용에 따른 SRAM 셀의 전기적 특성)

  • Lee, Deok-Jin;Kang, Ey-Goo
    • Journal of the Korea Computer Industry Society
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    • v.6 no.5
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    • pp.757-766
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    • 2005
  • There have been great demands for higher density SRAM in all area of SRAM applications, such as mobile, network, cache, and embedded applications. Therefore, aggressive shrinkage of 6T Full CMOS SRAM had been continued as the technology advances, However, conventional 6T Full CMOS SRAM has a basic limitation in the cell size because it needs 6 transistors on a silicon substrate compared to 1 transistor in a DRAM cell. The typical cell area of 6T Full CMOS SRAM is $70{\sim}90F^{2}$, which is too large compared to $8{\sim}9F^{2}$ of DRAM cell. With 80nm design rule using 193nm ArF lithography, the maximum density is 72M bits at the most. Therefore, pseudo SRAM or 1T SRAM, whose memory cell is the same as DRAM cell, is being adopted for the solution of the high density SRAM applications more than 64M bits. However, the refresh time limits not only the maximum operation temperature but also nearly all critical electrical characteristics of the products such as stand_by current and random access time. In order to overcome both the size penalty of the conventional 6T Full CMOS SRAM cell and the poor characteristics of the TFT load cell, we have developed $S^{3}$ cell. The Load pMOS and the Pass nMOS on ILD have nearly single crystal silicon channel according to the TEM and electron diffraction pattern analysis. In this study, we present $S^{3}$ SRAM cell technology with 100nm design rule in further detail, including the process integration and the basic characteristics of stacked single crystal silicon TFT.

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