• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.2
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• pp.139-143
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• 2005

The implications of temperature (25, 30 and $35^{\circ}C$) and relative humidity (RH; 60, 70 and $80\%$) on the hatching rhythmicity and hatching parameters (percentage and duration) were studied in the silkworm, Bombyx mori L. under natural photoperiod (LD 12 : 12). Disease free layings (DFLs) of two pure silkworm breeds, Pure Mysore (PM, a multivoltine breed) and $NB_4D_2$ (a bivoltine breed), and their hybrid, $PM{\times}NB_4D_2$ were introduced into the experimental conditions on the $3^{rd}$ day of oviposition till completion of hatching. The hatching rhythm was predominantly diurnal under all temperature and humidity conditions, with peaks just after 'lights-on' phase (6 hrs). Extreme temperature and humidity conditions did not alter the hatching rhythmicity, but prolonged the hatching durations, extending it to the next day, coupled with reduced hatching percentage in PM and $PM{\times}NB_4D_2{\cdot}In\;NB_4D_2$, on the other hand, hatching did not extend to the next day. Hatching percentage in this breed, however, reduced below the economic level under high temperature and low humidity conditions. The high temperature and low humidity together, though did not alter the rhythmicity, seems to exert synergetic effect on the hatching percentage and its duration in the silkworm, B. mori.

• Korean Journal of Child Studies
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• v.18 no.2
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• pp.191-211
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• 1997

This study investigated the characteristics of children perceived as difficult by their mothers and compared these characteristics with the "difficult temperament" from the NYLS. The subjects were 36 mothers who have more than one child between 3 and 6 years of age. The descriptions from in-depth interviews were analyzed qualitatively. The results showed that (1) Korean mothers perceived the difficult temperament of their child as low adaptability, low rhythmicity in sleep habits, negative mood, and high activity. High response sensitivity was perceived as both a positive and a difficult characteristic. (2) The temperament of their children mothers perceived as most difficult for child rearing were negative mood and low manageability. (3) The activity, adaptability, rhythmicity, response sensitivity, mood and manageability characteristics of Korean children's difficult temperament was different from the difficult temperament of the Nyls.

• The Korean Journal of Pharmacology
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• v.15 no.1_2 s.25
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• pp.13-19
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• 1979

Circadian susceptibility of sleeping induced by pentobarbital was observrd in male DDO mouse treated with phenobarbital and ginseng saponin. The pentobarbital elimination rate was also measured in the same animal. The mouse had been maintained for one week under 12 hours of artificial illumination extending from 06:00 to 18:00 hours alternating with 12 hours of darkness. During the period the animals were administered intraperitoneally with 100mg/kg of phenobarbital for three days or 10mg/kg and 100mg/kg of ginseng saponin for seven days. At 24 hours after last injection pentobarbital sleeping time and elimination rate were measured following intraperitoneal administration of 50mg/kg of pentobarbital sodium. In a control group treated with saline, the duration of pentobarbital-induced sleep varied with circadian rhythmicity, which had a trough at 02:00 hours of light phase and a crest at 14:00 hours of dark phase. And the elimination rate measured at 02:00 hours was faster than that at 14:00 hours. Pretreatment with phenobarbital markedly shortened the pentobarbital steeping time and abolished the circadian rhythmicity. Those were correlated with the increased pentobartital elimination by phenobarbital throughout light and dark phases examined. Ginseng saponin, given for seven days in a dose of 10mg/kg or 100mg/kg, did not affect the circadian rhythmicity of sleeping and the elimination rate. Sleeping time during light phase, however, was somewhat shortened in ginseng treated animals, which was not matched with the finding of unaltered elimination rate. It seemed that the central nervous system stimulating effect of ginseng saponin might be involved in the findings observed.

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.165.3-165
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• 2003

No Abstract, See Full Text

• Annals of Clinical Neurophysiology
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• v.3 no.2
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• pp.168-171
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• 2001

It has been said that variable anatomical structures and neural circuits are related to the generation of tremor. There are cerebral cortex, thalamus, basal ganglia, inferior olivary nucleus, midbrain tegmentum, stretch reflex, and musculoskeletal structures. The stretch reflex is related with the physiologic tremor and various peripherally originated tremors. We experienced a case with the post-stroke resting tremor which was induced and aggravated by mechanical stretching stimulation. In the present case, stretch reflex has a major role in the generation and exacerbation of tremor. It is presumed that the development of tremor is attributed to the increased rhythmicity of ventral intermedius nucleus of thalamus. The enhancement of thalamic rhythmicity may be due to the increasement of long latency reflex by post-stroke rigidity. This case suggests that stretch reflex may have a major role in the pathophysiologic mechanisms of a certain centrally originated tremor.

• Journal of the korean society of oceanography
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• v.31 no.3
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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.

• Sleep Medicine and Psychophysiology
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• v.15 no.1
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• pp.12-16
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• 2008

Light therapy (also called light treatment or phototherapy) involves scheduled exposure to bright artificial light. Evidence-based treatments for sleep disorders especially for circadian rhythm sleep disorders include light therapy and pharmacotherapy. In clinical practice, many of patients with sleep problems tend to impair circadian rhythmicity. Considering that light is the most potent entraining agent of circadian rhythm, careful use of light therapy can be recommended for patients with several kinds of sleep disorders. I briefly review the possible therapeutic mechanisms and clinical applications of light therapy, focusing on circadian sleep disorders.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.1
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• pp.22-30
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• 2013

The reproductive performance of multivoltine breed 'Nistari' and bivoltine breeds as NB18, P5 and a bivoltine hybrid (NB18 ${\times}$ P5) of B. mori were studied in different seasons in terms of total number of eggs laid, unlaid and hatching efficiency of the laid eggs to critically assess the breeds / hybrid potentiality. The bivoltine hybrid showed better performance in all the seasons as compared to the breeds investigated, as expected due to possibility of hybrid vigour. Among the breeds, bivoltine P5 had a better egg laid performance in S1 (February - March), S2 (May - June) and S3 (September - October) seasons but with an increase in the number of unlaid eggs. The hatching percentage, although didn't show any definitive trend, still suggested a marginal better performance in the hybrid. Most importantly, egg laying rhythmicity was studied by mating the female moth at 6.00 a.m. for $3{\frac{1}{2}}$ hours, and subsequently allowing the laying of eggs both under BOD condition ($25{\pm}1^{\circ}C$ and $85{\pm}5%$ RH) and at ambient temperature ($23-28^{\circ}C$ and $74.7{\pm}5%$) separately. Maximum (90%) egg laid occurred from 3.30 to 7.30 pm (i.e. 4 - 6 h after decoupling). Similar laying patterns were observed when females where mated at 12 noon and decoupled at 3.30 pm, revealing that late photoperiod and early scotoperiod were favourable for egg laying in case of multivoltine breed and bivoltine prefers late photoperiod for egg laying.

• Journal of the Korean Home Economics Association
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• v.42 no.11
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• pp.109-122
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• 2004

This study examined the characteristics of children, parents, family, and the extra context related to the parenting stress of employed and unemployed mothers from a broader perspective. The subjects were 323 employed mothers 3nd 300 unemployed mothers of pre-school age children. Parenting stress due to the role of being a parent for both employed and unemployed mothers was correlated with the chid's activity level, husband support, quality of life, available social support, and satisfaction of early childhood program's location. Parenting stress due to child-rearing of both employed and unemployed mothers was correlated with child's birth order, activity level and rhythmicity of child, husband support, quality of life, available social support, and satisfaction of early childhood program. Number of children was the strongest predictor of parenting stress due to the role of being a parent for employed mothers and the child's activity level for unemployed mothers. Besides, the child's activity level was the strongest predictor of parenting stress due to child-rearing for both employed and unemployed mothers.

• BMB Reports
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• v.48 no.12
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• pp.677-684
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• 2015

Cardiovascular function is regulated by the rhythmicity of circadian, infradian and ultradian clocks. Specific time scales of different cell types drive their functions: circadian gene regulation at hours scale, activation-inactivation cycles of ion channels at millisecond scales, the heart's beating rate at hundreds of millisecond scales, and low frequency autonomic signaling at cycles of tens of seconds. Heart rate and rhythm are modulated by a hierarchical clock system: autonomic signaling from the brain releases neurotransmitters from the vagus and sympathetic nerves to the heart's pacemaker cells and activate receptors on the cell. These receptors activating ultradian clock functions embedded within pacemaker cells include sarcoplasmic reticulum rhythmic spontaneous Ca²⁺ cycling, rhythmic ion channel current activation and inactivation, and rhythmic oscillatory mitochondria ATP production. Here we summarize the evidence that intrinsic pacemaker cell mechanisms are the end effector of the hierarchical brain-heart circadian clock system.