• BMB Reports
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• 제49권11호
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• pp.587-589
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• 2016

The circadian clock system enables organisms to anticipate the rhythmic environmental changes and to manifest behavior and physiology at advantageous times of the day. Transcriptional/translational feedback loop (TTFL) is the basic feature of the eukaryotic circadian clock and is based on the rhythmic association of circadian transcriptional activator and repressor. In Drosophila, repression of dCLOCK/CYCLE (dCLK/CYC) mediated transcription by PERIOD (PER) is critical for inducing circadian rhythms of gene expression. Pacemaker neurons in the brain control specific circadian behaviors upon environmental timing cues such as light and temperature cycle. We show that amino acids 657-707 of dCLK are important for the transcriptional activation and the association with PER both in vitro and in vivo. Flies expressing dCLK lacking AA657-707 in $Clk^{out}$ genetic background, homologous to the mouse Clock allele where exon 19 region is deleted, display pacemaker-neuron-dependent perturbation of the molecular clockwork. The molecular rhythms in light-cycle-sensitive pacemaker neurons such as ventral lateral neurons ($LN_vs$) were significantly disrupted, but those in temperature-cycle-sensitive pacemaker neurons such as dorsal neurons (DNs) were robust. Our results suggest that the dCLK-controlled TTFL diversify in a pacemaker-neuron-dependent manner which may contribute to specific functions such as different sensitivities to entraining cues.

• Interdisciplinary Bio Central
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• 제1권1호
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• pp.5.1-5.4
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• 2009

This article is an addendum to the authors’ previous article (Kim, J. et al. (2008) Plant Cell 20, 307-319). The instrumentation and software described in this article were used to analyze the circadian leaf movement in the previous article. Here, we provide detailed and practical information on the instrumentation and the software. The source code of the LMA program is freely available from the authors. The circadian clock regulates a wide range of cyclic physiological responses with a 24 hour period in most organisms. Rhythmic leaf movement in plants is a typical robust manifestation of rhythms controlled by the circadian clock and has been used to monitor endogenous circadian clock activity. Here, we introduce a relatively easy, inexpensive, and simple approach for measuring leaf movement circadian rhythms using a USB-based web camera, public domain software and a Leaf Movement Assay (LMA) program. The LMA program is a semi-automated tool that enables the user to measure leaf lengths of individual Arabidopsis seedlings from a set of time-series images and generates a wave-form output for leaf rhythm. This is a useful and convenient tool for monitoring the status of a plant's circadian clock without an expensive commercial instrumentation and software.

• The Journal of Korean Physical Therapy
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• 제29권3호
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• pp.142-144
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• 2017

Purpose: Few studies have addressed the effect of diurnal circadian rhythms on postural stability, and thus the aim of the present study was to examine circadian effects on static and dynamic postural stability in young adults. Methods: Twenty-four subjects (9 men, 11 women: age=$22.20{\pm}1.77$, height=$167.20{\pm}10.47$, weight=$59.85{\pm}10.66$) from a university community volunteered for this study. Static and dynamic balance testing, which recorded using a Good Balance system (Good Balance, Metitur Ltd, Finland) was conducted at 9:00, 13:00, and 17:00 hours on two consecutive days, and the sequencing of static and dynamic balance tests were randomized. Results were analyzed using the non-parametric one-way repeated Friedman test in SPSS version 18.0 (SPSS Inc., Chicago, IL, USA), and variable found to be significant were subjected to Wilcoxon post hoc testing. Results: Static and dynamic balance showed significant difference at the three times assessments (test at 9:00, 13:00, and 17:00) during circadian. In the post hoc test of static (anteroposterior distance, mediolateral distance and COP (center of pressure) velocity) and dynamic balance (performance time), 13:00 was the longer and faster than 9:00. Conclusion: These results indicated that control of postural balance is influenced by diurnal circadian rhythms, and confirm that control of postural balance is more effective and better performance in the 09:00 hours than 13:00 hours or 17:00 hours.

• Asian-Australasian Journal of Animal Sciences
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• 제10권3호
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• pp.304-307
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• 1997

Rectal temperature (Tr), skin surface temperatures (Ts), and heart rate (HR) were measured continuously from birth (day 1) till day 7, while resting heat production (HP) was measured in a chamber on days 1, 3, 5 and 7, in order to study the characteristic variation of Tr in newborn calves by heat balance methods. Despite constant levels of milk being given to the newborn calves each day, daily mean resting HP was lowest on the day of birth, then increased to peak on day 3 and then decreased slightly thereafter. Daily mean HR was higher on days 2, 3 and 4, than on other days. Tr exhibited diurnal rhythms and daily mean Tr was low on day 1, high on day 3, and then decreased slightly after day 3. Daily average mean skin temperature (mTs) was similar on all days. Mean body temperature (Tb) exhibited diurnal rhythms and had a similar range between days, suggesting that heat balance and thermoregulation were carried out effectively on each day. The variation of Tb appeared to be synchronized with that of HP and suggested that newborn calves might use variations in the levels of Tb to facilitate the body's required levels of heart loss.

• 생물정신의학
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• 제21권3호
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• pp.93-98
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• 2014

Objectives Circadian rhythms have been known to have associations with psychiatric disorders and personality traits. The present study investigated the relationships between circadian typology and temperaments/characters in a non-clinical Korean population. Methods Two hundred six healthy Korean college students (male 109, female 97) participated in this study. The subjects completed the Composite Scale of Morningness for circadian typology and 140-item Temperament and Character Inventory-Revised-Short version (TCI-RS). Results Multivariate analyses of covariance showed a significant association between chronotypes and temperamental dimensions of the TCI-RS. Morning types were significantly associated with lower harm avoidance and higher persistence and self-directedness dimensions, compared to evening types and intermediate types. No interaction effects between sex and chronotypes were shown for temperamental dimensions. Conclusions The present findings suggest that high persistence and self-directedness characters are related to morning types and high harm avoidance temperament is more related to evening types.

• Animal cells and systems
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• 제16권1호
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• pp.27-33
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• 2012

The suprachiasmatic nucleus (SCN) of the teleost hypothalamus contains a central circadian pacemaker, which adjusts circadian rhythms within the body to environmental light-dark cycles. It has been shown that exposure to darkness during the day causes phase shifts in circadian rhythms. In this study, we examined the effect of exposure to darkness on the mRNA expression levels of two circadian clock genes, namely, $Period2$ ($Per2$) and $Cryptochrome1$ ($Cry1$), and the rate-limiting enzyme in melatonin synthesis, arylalkylamine $N$-acetyltransferase-2 (Aanat2), in the pineal gland of olive flounder, $Paralichthys$ $olivaceus$. The expression of these genes showed circadian variations and was significantly higher during the dark phase. These changes may be involved in the mechanism of dark-induced phase shifts. Furthermore, this study suggests that olive flounder may be a teleost model to investigate the localization and function of circadian oscillators.

• Journal of Plant Biology
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• 제23권2호
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• pp.37-44
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• 1980

Kidneybean(Phaseolus vulgaris L.) and buckwheat(Fagopyrum esculentum M nch) seedlings grown with Hoagland solution to a height of 7 to 10 cm in the earthen pot containing sand were used for experimental plants. One group of the experimental plants was irrigated with Hoagland solution composed of various Pb-concentratons of 0 to 1000ppm containing 30ppm, and the other group was irrigated with Hoagland solution composed of various P-concentrations of 0 to 1,000ppm containing 30ppm Pb for a month during June and July in 1979. By Pb-surplus over 100ppm, the margins of buckwheat were curled down and turned into yellow-brown chlorosis, but the leaves of kidneybean were become dark-green at an early stage, and then developed chlorosis, finally shedded earlier than the control. Pb-toxicity was similar to the symptoms of P-deficiency. The ratio, 3/1 of chlorophyll a/b at an early stage, was unaffected by Pb-surplus or P-deficiency, but at the later stage it was altered. ATP content with Pb-surplus of 100ppm was decreased by 69% in kidneybean leaves and by 38% in buckwheat leaves, and it with P-deficiency was decreased by 75% in kidneybean leaves and by 43% in buckwheat leaves. In the assay of ATP content of the leaves at intervals of three hours for one day of July in the year, the rhythms of ATP level were unaffected by light or temperature although the amplitude of the level was modified. The rhythms of Pb-surplus and P-deficiency plants were observed at the lower range of ATP content than that of control.

• Child Health Nursing Research
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• 제18권2호
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• pp.85-94
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• 2012

Purpose: Instead of a chaotic non circadian environmental approach, continuing regular day-night rhythm in neonatal nurseries may benefit the development of preterm infants. The purpose of this study was to define the effects of cycled lighting on circadian rhythms of premature infants. Methods: The experimental group included 15 preterm infants, and the control group, 15 premature infants in the NICU of a general hospital in Seoul. All infants were between 32 and 37 weeks' postconceptional age. The experimental group infants were provided with cycled lighting before discharge. The incubator or bassinet cover of the experimental group was off between 7 AM and 7 PM, and was covered between 7 PM and 7 AM. Results: There were significant differences in the NNNS score ($p$=.039), and some significant differences in the sleep-activity pattern between the experimental group and the control group, but distinct differences in sleep-activity patterns between the two groups could not be defined. Conclusion: The results of this study suggest that cycled lighting can be helpful in the neurobehavioral development of preterm infants. By modifying the NICU environment to provide a more developmentally supportive milieu, nursing professionals can better meet the infants' physiologic and neurobehavioral needs.

• 공연문화연구
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• 제40호
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• pp.343-372
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• 2020

본고는 동해안 무속에서 사용하는 굿거리장단의 변주유형의 운영을 연구한 논문이다. 동해안 별신굿 예능보유자였던 고(故)김용택의 굿거리장단 연주가 다른 장르에서 보았던 굿거리장단과 색다르게 다가왔고 그 요인을 찾기 위해 그가 연주할 때 사용하는 변주유형과 연주기법들을 살펴보았다. 동해안 무속 굿거리장단은 여타 다른 장르에서 연주되는 굿거리장단의 유형과 기법보다 다양한 변주유형이 존재하며 독특한 형태의 기법들을 사용하고 있다. 이 같은 다양한 변주유형과 독특한 연주기법이 실제 연주에 반영되어 즉흥적인 변주가 이루어지고 있다.

• 한국시조학회지:시조학논총
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• 제19권1호
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• pp.85-106
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• 2003

본질적으로 입으로 소리내어 읊조리고 청각으로 감상하기 위해 만들어지고, 일정한 형식 안에서 음성의 조화와 운율의 음악성을 중시한 소네트와 시조의 표현형식은 전반적으로 기의signifie와 관련하여 고찰되어야 한다. 보들레르의 <깨진 종>과 김종서의 <삭풍가>을 표현형식의 의미작용을 중심으로 분석해 본 결과 시적 자아의 정서는 표현형식과 밀접하게 연관되어 있다. 소네트나 시조는 의미, 율격, 각운, 음성구조, 리듬 등 여러 개별적 요소들의 집합체가 아니라 이 모든 요소들이 서로 상호 작용하는 통일된 유기체이다. 시대의 흐름에 발맞춰 낭송법에 대한 이론을 체계적으로 정립하여 시를 콘텐츠화 하여 유통방식의 변화를 꾀해야 한다. 그러기 위해서 그 자체가 표현가치를 가지는 표현형식은 낭송에 있어서 최우선 적으로 고려되어야 할 기본원리이다.