• 제목/요약/키워드: alternative respiration

검색결과 28건 처리시간 0.028초

Variation of Alternative and Cytochrome Respiration during Ripening in Rice Leaves

  • Lee, Kwang-hong
    • 한국작물학회지
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    • 제47권4호
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    • pp.301-304
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    • 2002
  • The variation of alternative and cytochrome respiration during ripening in rice leaves (Oryza sativa L. cv. Takanari) was examined. The capacity of both respiration pathway was measured by inhibitor titration method using gas-phase oxygen electrodes. The alternative respiration rate decreased from 31.3% of the total respiration rate at around heading to 11.7% at 34 days after heading in the first fully expanded leaf from the top, and further to 6.4 % at 34 days after heading in the fourth leaf from the top. In contrast, the proportion of cytochrome respiration to total respiration increased with leaf senescence. The possible cause of alternative respiration as either an increase in inefficient respiration or a decrease in growth efficiency during ripening was discussed.

Arabidopsis SIZ1 positively regulates alternative respiratory bypass pathways

  • Park, Bong-Soo;Kim, Sung-Il;Song, Jong-Tae;Seo, Hak-Soo
    • BMB Reports
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    • 제45권6호
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    • pp.342-347
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    • 2012
  • Plant mitochondria possess alternative respiratory pathways mediated by the type II NAD(P)H dehydrogenases and alternative oxidases. Here, E3 SUMO ligase was shown to regulate alternative respiratory pathways and to participate in the maintenance of carbon and nitrogen balance in Arabidopsis. The transcript abundance of the type II NAD(P)H dehydrogenases NDA2 and NDB2 and alternative oxidases AOX1a and AOX1d genes was low in siz1-2 mutants compared to that in wild-type. The addition of nitrate or ammonium resulted in a decrease or an increase in the expression of the same gene families, respectively, in both wild-type and siz1-2 mutants. The amount of free sugar (glucose, fructose and sucrose) was lower in siz1-2 mutants than that in wild-type. These results indicate that low nitrate reductase activity due to the AtSIZ1 mutation is correlated with an overall decrease in alternative respiration and with a low carbohydrate content to maintain the carbon to nitrogen ratio in siz1-2 mutants.

D-Erythroascorbic acid regulates cyanide-resistant respiration in Candida albicans

  • Lee, Jung-Shin;Huh, Won-Ki;Kang, Sa-Ouk
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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    • pp.42-42
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    • 2001
  • Candida albicans possess cyanide-resistant respiratory pathway, which is mediated by alternative oxidase. The activity of alternative oxidase has been found to be dependent on several regulatory mechanisms. In order to investigate the influence of D-erythroascorbic acid on respiration of C. albicans, the respiratory activity of the cells was measured with oxygen monitor. ALO1 is known to encode D-arabinono-1,4-lactone oxidase that catalyses the final step of D-erythroascorbic acid biosynthesis in C. albicans.(omitted)

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Cholera Toxin Production Induced upon Anaerobic Respiration is Suppressed by Glucose Fermentation in Vibrio cholerae

  • Oh, Young Taek;Lee, Kang-Mu;Bari, Wasimul;Kim, Hwa Young;Kim, Hye Jin;Yoon, Sang Sun
    • Journal of Microbiology and Biotechnology
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    • 제26권3호
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    • pp.627-636
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    • 2016
  • The causative agent of pandemic cholera, Vibrio cholerae, infects the anaerobic environment of the human intestine. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly induced during anaerobic respiration with trimethylamine N-oxide (TMAO) as an alternative electron acceptor. However, the molecular mechanism of TMAO-stimulated CT production is not fully understood. Herein, we reveal that CT production during anaerobic TMAO respiration is affected by glucose fermentation. When the seventh pandemic V. cholerae O1 strain N16961 was grown with TMAO and additional glucose, CT production was markedly reduced. Furthermore, an N16961 Δcrp mutant, devoid of cyclic AMP receptor protein (CRP), was defective in CT production during growth by anaerobic TMAO respiration, further suggesting a role of glucose metabolism in regulating TMAO-mediated CT production. TMAO reductase activity was noticeably decreased when grown together with glucose or by mutation of the crp gene. A CRP binding region was identified in the promoter region of the torD gene, which encodes a structural subunit of the TMAO reductase. Gel shift assays further confirmed the binding of purified CRP to the torD promoter sequence. Together, our results suggest that the bacterial ability to respire using TMAO is controlled by CRP, whose activity is dependent on glucose availability. Our results reveal a novel mechanism for the regulation of major virulence factor production by V. cholerae under anaerobic growth conditions.

Saccharomyces cerevisiae를 이용한 효율적인 호흡저해제 검정법 (Efficient assay for respiration inhibitor using Saccharomyces cerevisiae)

  • 최경자;김진철;김흥태;조광연
    • 농약과학회지
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    • 제4권3호
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    • pp.52-59
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    • 2000
  • Saccharomyces cerevisiae를 이용하여 효율적인 호흡저해 스크리닝 방법을 개발하고자 실험하였다. S. cerevisiae균을 glucose 발효와 미토콘드리아 호흡이 가능한 yeast extract-peptone-dextrose (YPD) 배지와 단지 미토콘드리아 호흡만이 가능한 non-fermentable carbon source-yeast extract (NFY) 배지로 수확하였다. 96-well plate의 각 well에 균 현탁액을 분주한 다음 다양한 작용기작의 46개 살균제를 여러 가지 농도로 처리하였다. NFY배지에서의 non-fermentable carbon source로는 ethanol (NFY-E배지) 및 glycerol (NFY-G배지), lactate (NFY-L배지)를 이용하였다. 접종 후 $1{\sim}3$일 동안 배양한 다음 최소억제농도 (minimum inhibitory concentration, MIC)를 결정한 결과, 4개의 호흡억제 살균제인 azoxystrobin, kresoxim-methyl, metominostrobin, trifloxystrobin은 YPD 배지에서 균의 생육을 전혀 억제하지 못하였으나, 세가지 NFY배지에서는 높은 항균활성을 보였다. 이와는 반대로 5개의 N-trihalomethylthio계 살균제는 NFY배지보다 YPD 배지에서 높은 활성을 보였다. 그리고 11개 살균제는 두 배지 모두에서 같은 항균활성을 나타내었고, 나머지 26개의 살균제는 모든 배지에서 전혀 항균활성을 보이지 않았다. 그러므로 S. cerevisiae와 96-well plate를 이용한 호흡저해제 검정법은 신속하고 편리하게 호흡저해제를 스크리닝 할 수 있는 방법으로 여겨진다.

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Effects of Gamma Irradiation and Methyl Bromide Fumigation on the Qualities of Fresh Chestnuts during Storage

  • Kwon, Joong-Ho
    • Food Science and Biotechnology
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    • 제14권2호
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    • pp.181-184
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    • 2005
  • Effects of irradiation and fumigation on disinfestation and quality attributes of chestnuts during storage were studied. Fresh chestnuts were exposed to gamma irradiation (0-10 kGy) and methyl bromide (MeBr) under commercial conditions and stored at different temperatures for 6 months. Pest of quarantine importance for chestnuts, Curculio sikkimensis Heller showed 100% mortality by MeBr on 3rd day after fumigation and by irradiation at 0.5 kGy in about 3 weeks at $23{\pm}0.5^{\circ}C$. Respiration rates of samples one day after treatments increased in proportion to irradiation dose. Respiration pattern of MeBr group was equal to that of 10 kGy-group. Both MeBr and irradiation at 0.25 kGy or higher showed 100% inhibition of sprouting during storage at $5^{\circ}C$ for 6 months. Flesh firmness was significantly reduced by MeBr or irradiation over 5 kGy (p<0.05) 1 day after treatments. MeBr fumigation resulted in appreciable decrease in flesh weight, reducing sugar and ascorbic acid contents (p<0.05), as compared to irradiated samples. Irradiation at 0.5 kGy was effective as alternative to MeBr in controlling pests while maintaining overall quality of fresh chestnuts during storage.

생물 II '세포호흡' 단원에서 역할놀이 비유 수업의 효과 (Effect of the Analogical Role-playing Activity on the "Cellular Respirations" Unit in Biology II Class)

  • 김동렬
    • 한국과학교육학회지
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    • 제29권4호
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    • pp.463-476
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    • 2009
  • 본 연구의 목적은 학생들이 직접 세포호흡 과정의 주요부분이 되어 역할을 행동으로 옮기는 역할놀이 비유 수업을 실시하여 학생들의 세포호흡에 대한 학업 성취도와 과학 학습동기에 미치는 효과를 알아보는데 있다. 역할놀이 비유 수업의 적용 효과를 알아보기 위해 부산 소재의 인문계 고등학교 생물 II를 선택한 2개반을 대상으로 1개 반(27명)은 실험집단으로 1개반(28명)은 통제집단으로 구성하여 연구를 진행하였다. 본 연구를 통해 얻은 결과는, 첫째, 역할놀이 비유 수업은 세포호흡에 대해서 학생들이 역할을 분담하고 직접 신체 감각적 활동을 통하여 개념을 설명할 수 있는 기회를 제공하여 학업 성취도를 향상시킨 것으로 나타났다. 둘째, 역할놀이 비유 수업을 통해 학생들은 과학에 대한 자신감과 과학과의 관련성을 발견하고 성취감이 증가하면서 만족감을 느끼고 이를 통해 과학 학습동기가 향상된 것으로 나타났다. 셋째, 개념 변화에 대한 면담 결과에서, 학생들은 선개념에 대한 불만족을 가지고 있었고, 역할놀이 비유 수업은 지적으로 이해할 수 있는 대안으로 생각하고 있었으며, 그 대안은 그럴듯하고 유용한 것으로 나타났다.

호흡 기반 사람과 사물 구분 가능한 FMCW 레이다 신호처리 프로세서의 설계 (Design of FMCW Radar Signal Processor for Human and Objects Classification Based on Respiration Measurement)

  • 이윤구;윤형석;김수연;허성욱;정윤호
    • 한국항행학회논문지
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    • 제25권4호
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    • pp.305-312
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    • 2021
  • 보안 시스템에는 다양한 센서가 사용되고 있지만, 사생활 문제가 논란이 됨에 따라 레이다 센서가 대안으로 제시되고 있다. 그 중 PD (Pulse Doppler) 레이다는 짧은 펄스를 사용함으로써 수신부 복잡도가 증가하는 문제가 존재하나, FMCW (Frequency modulated continuous wave) 레이다는 그러한 제한이 적다는 장점이 있다. 그러나, FMCW 레이다는 2D-FFT (2-dimensional fast Fourier transform)를 사용하므로 기존의 센서에 비해서 상대적으로 높은 복잡도를 가지며, 정지해있는 표적에 대해 사람과 사물을 구분하기 어려운 단점이 있다. 따라서 본 논문에서는 1D-FFT와 위상 변화만으로 호흡 여부를 확인하여 사람과 사물을 구분할 수 있는 레이다 신호처리 프로세서의 설계 및 구현 결과를 제시한다. 제안된 신호처리 프로세서는 Verilog-HDL을 기반으로 설계하여 FPGA 디바이스에 기반하여 구현 및 검증하였다. LUT (Look up table) 6,425개, register 4,243개, 12,288개의 memory bit로 구현하여 92.1%의 정확도로 대상의 호흡 여부를 확인할 수 있음을 확인하였다.

RGB-LED-based Optical Camera Communication using Multilevel Variable Pulse Position Modulation for Healthcare Applications

  • Rachim, Vega Pradana;An, Jinyoung;Pham, Quan Ngoc;Chung, Wan-Young
    • 센서학회지
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    • 제27권1호
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    • pp.6-12
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    • 2018
  • In this paper, a 32-variable pulse position modulation (32-VPPM) scheme is proposed to support a red-green-blue light-emitting-diode (RGB-LED)-based optical camera communication (OCC) system. Our proposed modulation scheme is designed to enhance the OCC data transmission rate, which is targeted for the wearable biomedical data monitoring system. The OCC technology has been utilized as an alternative solution to the radio frequency (RF) wireless system for long-term self-healthcare monitoring. Different biomedical signals, such as electrocardiograms, photoplethysmograms, and respiration signals are being monitored and transmitted wirelessly from the wearable biomedical device to the smartphone receiver. A common 30 frames per second (fps) smartphone camera with a CMOS image sensor is used to record a transmitted optical signal. Moreover, the overall proposed system architecture, modulation scheme, and data demodulation are discussed in this paper. The experimental result shows that the proposed system is able to achieve > 9 kbps using only a common smartphone camera receiver.

Respiratory Sinus Arrhythmia: Methods of Measurement and Interpretations of Tonic and Dynamic Vagal Cardiac Drive Index in Psychophysiology of Emotions

  • Estate M.Sokhadze;Lee, Jong-Mi;Park, Mi-Kyung;Sohn, Jin-Hun
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2000년도 추계학술대회 논문집
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    • pp.81-87
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    • 2000
  • Beat-to-beat changes in heart period (heart period variability, HPV) are mediated by fluctuations in autonomic activity. Spectral analysis is used to quantify such fluctuations in the range of 0.15-0.40 Hz (high frequency, HF), which are influenced primarily by parasympathetic factors. These fluctuations are often referred to as RSA (respiratory sinus arrhythmia), the physiological phenomenon extracted by spectral analysis and other methods including histograms of heart rate ( HR), deviations of HR etc. Respiratory sinus arrhythmia indexing with peak-to-valley method suggested by Grossman et at., (1981) yields a simple range statistic and is quantified on breath-by-breath basis, thus being quite sensitive and less dependent on recording time as compared to spectral analysis. It is strongly recommended to use at least 1 min epoch to asses HF component of HPV and at least 2 min fer low frequency (LF) of HPV and even 5 min far valid clinical assessment. Peak-to-valley statistic is limited to RSA index only, but has its pragmatic advantages. Most important is possibility of its application far relatively small epoch analysis. We used short periods (20,30, 40 sec only) and off-line analysis of RSA using ECG and respiration curve this method of assessment and proved that this method is more practically effective. The RSA index was not so far dependent on respiration pattern differences and reflected actual vagal control of HR and were accompanied by low HR under some high stress conditions and in an aversive affective visual stimulation experiments. Another factor that might modulate cardiac chronotropic response is the interaction of sympathetic and parasympathetic inputs on sino-atrial (SA) node level, because responses to vagal influences are known to be proportional to ongoing sympathetic activity, that is so called accentuated antagonism. Since sympathetic outflow (increment of influences on SA) under negative emotions or stress was high in almost all physiological responses, vagal effects on HR could be therefore potentiated, leading to masking of output cardiac response seen in HPV, In the case of moderate sympathetic activation, on the other hand, autonomic interactions in cardiac control appear to be minimal. Thus RSA index appears to be an effective alternative method to assess and measure spectral HPV.

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