• 제목/요약/키워드: rhythms

검색결과 225건 처리시간 0.026초

A Rhythmicity in the rate of Oxygen Consumption by the Manila clam, Ruditapes philippinarum

  • Kim, Wan-Soo;Rumohr, Heye;Schimid, Michael K.;Koh, Chul-Hwan
    • Journal of the korean society of oceanography
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    • 제31권3호
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    • pp.117-122
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    • 1996
  • Oxygen consumption by the Manila clam, Ruditapes philippinarum (Bivalvia: Veneridae) maintained in a culture tank for 7-10 weeks was measured with an automatic intermittent-flow-respirometer (AIFR). There was evidence for an endogenous tidal rhythm of 12.4 h in oxygen consumption, at irregular intervals of between about 7 and 18 hours during experiments of between 22 h 5 min and 70 h 32 min (duration) recording for fasting animals in constant darkness at constant temperatures in the absence of tidal rhythms.

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Possible involvement of temperature-entrainable timing system in arrhythmic mutant flies in Drosophila melanogaster

  • Yoshii, Taishi;Tomioka, Kenji
    • Journal of Photoscience
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    • 제9권2호
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    • pp.240-242
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    • 2002
  • In Drosophila melanogaster, it is known that the circadian clock consists of an autoregulatory feedback loop, which includes so-called clock genes, such as per, tim, dClk and cyc and produces periodical expression of per. It is recently suggested, however, that the circadian oscillation without the rhythmical expression of per is involved in the regulation of circadian locomotor rhythms. In the present study, we examined the existence and the property of the possible per-less oscillation using arrhythmic clock mutant flies carrying per$^{01}$, tim$^{01}$, dClk$^{Jrk}$ or cyc$^{01}$. When temperature cycles consisting of 25$^{\circ}$C and 30$^{\circ}$C with varying periods (T = 8~32 hr) were given, they showed rhythms synchronizing with the given cycle under constant darkness (DD). per$^{01}$ and tim$^{01}$ flies always showed a peak around 7 hr after the onset of thermophase irrespective of Ts of temperature cycles, while dClk$^{Jrk}$ and cyc$^{01}$ flies did not. In addition, several days were necessary to establish a clear temperature entrainment in per$^{01}$ and tim$^{01}$ flies, when they were transferred from a constant temperature to a temperature cycle under DD. These results suggest that per$^{01}$ and tim$^{01}$ flies have a temperature-entrainable weak oscillatory mechanism. The fact that dClk$^{Jrk}$ and cyc$^{01}$ flies did not show any sign of the endogenous oscillation suggests that the per-less oscillatory mechanism may require CLK and CYC.

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Simultaneous quantitative analysis of salivary cortisol and cortisone in Korean adults using LC-MS/MS

  • Lee, Sang-Hoo;Kwon, Soon-Ho;Shin, Hye-Jin;Lim, Hwan-Sub;Singh, Ravinder J.;Lee, Kyoung-Ryul;Kim, Young-Jin
    • BMB Reports
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    • 제43권7호
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    • pp.506-511
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    • 2010
  • The levels of salivary cortisol and cortisone in Korean adults were measured for the first time using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The salivary cortisol and cortisone were separated within 10 min. The regression coefficients (r) of the calibration curves were greater than 0.999 for the two steroids. The limits of quantitation (LOQ) were 0.2 ng/ml for cortisol and 1 ng/ml for cortisone. The intra-day precisions of the assay were <3.9% and 8.6% for cortisol and cortisone respectively, and the inter-day precisions were <1.9% and 4.3% for cortisol and cortisone, respectively. The salivary cortisone concentrations were approximately 4-9 times higher than those of salivary cortisol during the daytime. Diurnal rhythms, during which the cortisol and cortisone concentrations were higher in the morning than in the afternoon, were also observed. The present assay may be useful for the diagnosis of several adrenal dysfunctions in clinical biochemistry.

넙치(Pralichthys olivaceus)의 혈액건강지표의 활동일주기와 단기절식에 따른 생리적 반응 (Daily Rhythms and Effect of Short-term Starvation on the of Health Parameters in Olive Flounder Paralichthys olivaceus)

  • 노경언;김우진;김현철;박철지;박종원
    • 한국수산과학회지
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    • 제50권5호
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    • pp.534-540
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    • 2017
  • This study was conducted to determine the circadian rhythm and the effect of starvation for the health assessment of olive flounder Paralichthys olivaceus, reared under 12:12 LD (light:dark) cycle and fed 1% of their body weight once a day. The blood collection was implemented from 10 fish every 3 hours for a day, and analyzed to serval health parameters of the experimental fish. Plasma cortisol, glucose and total protein concentration reflected diel rhythms with high level of photophase and low level of scotophse despites of glutamic oxalacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) showing no rhythmicity, while electrolyte (sodium, potassium and chloride ion) concentrations arrived at the peak 18 hour and then slowly down. In the experiment of starvation, the result showed that there were no significant differences of the health parameters between the starved group and the fed. In short, our findings described the existence of circadian cortisol with glucose in flat fish, and indicated that the starvation does not almost affect the health of fish.

동작연기의 표현력 향상을 위한 한국춤의 호흡운용법 (Breathing of Korean Dance for Develop Methodology of Expression)

  • 정선혜
    • 한국콘텐츠학회논문지
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    • 제10권6호
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    • pp.249-257
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    • 2010
  • 공연예술에 있어서 무대 위에서 움직이는 연기자의 역할은 중요한 의미를 지니고 있다. 공연예술이 목표하는 바가 단순히 표피적 또는 상투적 즐거움의 생산과 표현에 있는 것이 아니라 인간의 근원적 삶에 대한 철학적 정신의 정화를 추구하며, 이러한 역할 표현의 중심이 바로 연기자의 몫으로 설정되기 때문이다. 공연예술은 단순히 기술적인 작업이 아니며, 한 나라의 정체성과 전통을 아우르는 문화적 창조 작업이어야 한다. 그러나 오늘날 우리의 공연예술의 표현방법은 다분히 서구적 공연예술 양식의 방법론을 따르고 있다. 이러한 서구 지향의 공연예술 방법론을 극복하고, 보다 주체적이고 한국적인 공연예술의 창작과 동작연기의 표현력 향상을 위한 새로운 방법론이 제시되어져야 할 것이다. 본 논문은 전통 한국춤에서 운용되어지고 있는 호흡법과 장단을 현대 공연예술의 시간성과 공간성을 연관시켰을 때 나타나는 동작연기의 시각적 효과와 표현력 향상에 관한 연구이다. 이를 위해 한국춤의 근간을 이루는 호흡운용에 관한 기본적 이해를 바탕으로 연기자의 동작연기의 표현력 향상을 위한 호흡운용 프로그램 모델을 제시하고 있다.

사수도에서 번식하는 슴새의 포란 일정 및 성 역할 (Incubation Routine and Sex Role of Streaked Shearwaters Calonectris leucomelas at Sasudo Island, South Korea)

  • 남기백;권인기;유정칠
    • Ocean and Polar Research
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    • 제30권1호
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    • pp.11-19
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    • 2008
  • Incubation routine and sex role of Streaked Shearwaters Calonectris leucomelas at Sasudo Island, in Jeju, South Korea, were studied during the incubation period, June to August in 2002. Incubation routine in Procellariiformes represents a sequence of alternating shifts taken in turn by female and male in a species-specific pattern. Hence, coordination of individual incubation rhythms between partners is crucial for successful breeding attempt. In Streaked Shearwaters, incubation routine represents a sequence of alternating shifts taken in turn by male and female. The first incubation shift was made by male after female had laid the egg. The mean incubation period was 50.8 days until hatching. Males had spent on average 26.5 days incubating and females 24.3 days accordingly. The mean duration of incubation shifts decreased progressively from 6th and 7th shift to hatching. Overall, males had spent more time incubating than females during the incubation period, but the mean duration of the incubation shift 5.6 days for males and 5.7 days for females did not differ between males and females. There were no effect of the body size of the breeding pair on incubation performance. For males the mean of body weight decreased during the incubation, whereas for females it remained approximately stable. In Streaked Shearwaters, the duration of incubation shift and subsequent foraging trip are related to loss of body weight during the period of fasting. In addition, coordination of individual incubation rhythms affects their incubation behaviour.

현대패션에 표현된 개더 장식의 미적 특성 연구 - 2001년 이후 컬렉션을 중심으로 - (A Study on the Aesthetic Characteristics of Gather Decorations in the Contemporary Fashion - Focusing on the Collections after 2001 -)

  • 윤진아
    • 한국의상디자인학회지
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    • 제8권1호
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    • pp.155-168
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    • 2006
  • The purpose of this study focusing on the gather decorations shown in the modern fashion was to review needlework techniques and design features of gather decorations and thereupon, analyze the aesthetic characteristics of gather decorations shown in designers' works to examine the gather decoration trend in today's fashion. First, the decorative features of gather decorations different from the conventional costumes are shirring, lace and trimming combined or shirring repeated. Second, in view of sensualism, the gather decorations seem to play a role of enhancing the exposure as a mode of expression, while the indirect exposure or beach is mixed with the materials to widen the range of gather decoration expressions. Third, in terms of history, the conventional decorative techniques are combined with new techniques and materials to create a fantastic and romantic mood different from the conventional costumes. Fourth, in view of rhythms, the wave line of the rim for gather decorations serves to express some vivid effects; on the human body, its monotonous plane repetition will turn into a new expression or a voluminous physical sense of motion. However, since expressions or meanings of the gather decorations are much diversified, they should not be regarded as simple decoration details. Our modern designers searching for new expression of creases use unique structural forms to explore the possibility of creative gather decorations. In all, since gather decorations seem to be significant as unique details conducive to a structural pragmatism and aesthetics, it is deemed necessary to continue to develop gather decorations.

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뇌파의 입력패턴벡터 추출 및 패턴인식 (Input Pattern Vector Extraction and Pattern Recognition of EEG)

  • 이용구;이선엽;최우승
    • 한국컴퓨터정보학회논문지
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    • 제11권5호
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    • pp.95-103
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    • 2006
  • 본 논문에서는 뇌파인식을 위한 입력패턴벡터를 추출하고 패턴인식을 위한 뇌파 학습 알고리즘을 설계하였다. 입력패턴벡터의 구성을 위해 알파리듬과 베타리듬의 주파수와 진폭이 사용되었고, 뇌파패턴인식을 위한 알고리즘은 초기 참조벡터의 학습을 위해 SOM을 이용하고, 종속 부류층의 출력뉴런의 부류지정을 위하여 out-star 학습법을 사용하였다. 제안된 알고리즘의 입력 층과 종속 클래스 층 사이의 연결강도는 SOM과 LVQ 알고리즘을 이용하여 초기 참조벡터의 설정 및 학습이 가능하게 하였고, 패턴벡터를 종속 부류층의 뉴런에 의해 종속 클래스로 분류하고, 종속 클래스 층과 출력 층 사이의 연결강도는 분류된 종속 부류를 클래스로 지정하는 학습을 하게 된다. 뇌파 패턴 분류를 위하여 제안된 학습알고리즘을 이용하여 시뮬레이션 되었고 기존의 LVQ 학습방식보다 우수한 분류성공률을 확인하였다.

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Xylene 대사 효소 활성에 미치는 주.야 시차의 영향 (Effect of Circadian Rhythms on the Xylene Metabolizing Enzyme Activities in Rats)

  • 이혜자;윤종국
    • 한국환경보건학회지
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    • 제27권2호
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    • pp.10-16
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    • 2001
  • To evaluate an effect of circadian variation on the xylene metabolizing enzyme activities, 50% m-xylene in olive oil(0.25 $m\ell$/100g body weight) was intraperitoneally administered to the rats every other day for 6 days both in the night; 24:00 and the day; 12:00. Then animals were sacrigiced at 8hr after last injection of m-xylene. Hepatic microsomal cytochrome p450 contents were more increased both in control and xylene treated rats of night phase than those of day phase. But the activity of hepatic alcohol dehydrogenase(ADH) in control of night phase showed the similar value with that in those of day phase and xylene treated rats of day phase showed an increasing tendency of hepatic ADH activity as those of night phase showing similar activity. Furthermore, control rats of night phase than those of day phase. And by xylene treatment, enzyme activities of rats of day phase were higher tendency in rats of control but those of night phase were somewhat inhibited. Besides, xylene-treated animals of night phase showed increasing tendency of urinary methylhippuric acid concentration compared with those of day phase. On the other hand, liver weight per body weight(%), hepatic lipid peroxide content and serum xanthine oxidase activity were higher in night phase. And the activities of hepatic oxygen free radical metabolizing enzymes such as xanthine oxidase, gluthathione S-transferase, and xylene-treated rats of night phase than those of day phase. In conclusion, it can be hypothesized on the basis of the results that the accumulation rate of m-xylene intermediate metabolite, i.e. m-methylbenzaldehyde in liver tissus may be higher in night phase than in day phase and it may be responsible for higher liver toxicity in bight phase than in day phase.

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