• Fisheries and Aquatic Sciences
• /
• v.4 no.3
• /
• pp.130-137
• /
• 2001

In the present study, the locomotor and feeding activities of single red sea bream, Pagrus major were simultaneously investigated to examine the existence of such dual behaviour. Seven red sea bream of 13cm body length on average were placed individually in 35L tanks equipped with an infrared sensor and a newly developed demand-feeding device. Fish were exposed to a light: dark 12: 12h cycle and constant darkness (DD) to study endogenous rhythmicity. Under LD 12: 12 h, the daily pattern of behaviour differed between individual fish; some red sea bream were diurnal and others were nocturnal. Futhermore, some of them displayed an extraordinary flexibility in phasing because they were dark active but light feeding, and vice versa. Under DD, red sea bream showed free-running rhythms for locomotor activity and feeding. These results indicate that the type of phasing of locomotor activity did not necessarily decide the feeding phase; much of this is explained by the fact that red sea bream were demand-fed. Flexibility in phasing and a certain degree of independence between locomotor and feeding activities could be seen as an adaptative response of the highly adaptable circadian rhythms of fish.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.9
• /
• pp.1209-1215
• /
• 2001

We conducted this study to investigate 24 h leptin profiles and to ascertain whether leptin secretion occurs in a pulsatile manner in cattle. Plasma leptin concentrations were measured every 10 min for 24 h in five Holstein steers aged 10 months. Simultaneously, feeding behavior was recorded every 5 min during this experiment. In two of the five cattle, leptin showed diurnal rhythmicity, which could be described by a cosine, with peaks between 15:00 and 16:00 and nadirs at around midnight. Pulsatile leptin release was quantified by model-free Cluster analysis. Plasma leptin showed a pulsatile pattern in all cattle, with an average number of pulses at 15 peaks/24 h. The daily number of pulses was not related to total time spent eating, ruminating or chewing. However, when divided into six 4 h time intervals, time spent ruminating was positively related with pulse number (p=0.05) in cattle showing no diurnal plasma leptin variation. These results suggest that cattle may have unique diurnal variation and pulsatile patterns of plasma leptin, differing from those of monogastric animals.

• The Korean Journal of Physiology and Pharmacology
• /
• v.9 no.4
• /
• pp.203-207
• /
• 2005

Electrical rhythmicity in the gastrointestinal (GI) muscles is generated by pacemaker cells, known as interstitial cells of Cajal (ICC). In the present study, we investigated the effect of external divalent cations on pacemaking activity in cultured ICC from murine small intestine by using whole-cell patch clamp techniques. ICC generated pacemaker currents under a voltage clamp or electrical pacemaker potentials under a current clamp, and showed a mean amplitude of $-500{\pm}50$ pA or $30{\pm}1$ mV and the frequency of $18{\pm}2$ cycles/min. Treatments of the cells with external 0 mM $Ca^{2+}$ stopped pacemaking activity of ICC. In the presence of 2 mM $Ca^{2+}$, 0 mM external $Mg^{2+}$ depolarized the resting membrane potential, and there was no change in the frequency of pacemaking activity. However, 10 mM external $Mg^{2+}$ decreased the frequency of pacemaking activity ($6.75{\pm}1$ cycles/min, n=5). We replaced external 2 mM $Ca^{2+}$ with equimolar $Ba^{2+}$, $Mn^{2+}$ and $Sr^{2+}$, and they all developed inward current in the sequence of $Ba^{2+}$>$Mn^{2+}$>$Sr^{2+}$. Also the frequency of the pacemaking activity was stopped or irregulated. We investigated the effect of 10 mM $Ba^{2+}$, $Mn^{2+}$ and $Sr^{2+}$ on pacemaking activity of ICC in the presence of external 0 mM $Mg^{2+}$, and found that 10 mM $Ba^{2+}$ and $Mn^{2+}$ induced large inward current and stopped the pacemaking activity of ICC (n=5). Interestingly, 10 mM $Sr^{2+}$ induced small inward current and potentiated the amplitude of pacemaking activity of ICC (n=5). These results indicate that extracellular $Ca^{2+}$ and $Mg^{2+}$ are requisite for the pacemaking activity of ICC.

• Annals of Clinical Neurophysiology
• /
• v.4 no.2
• /
• pp.133-136
• /
• 2002

Dyskinesia can occur as a neurological abnormality due to stroke, and its incidence in stroke patients is reported to be about 1%. It is possible to classify dyskinesia into one of the morphologic types already classified clinically. However, a specific type of dyskinesia can occur; one which does not fall into the existing morphologic types. We experienced such a case of specific type dyskinesia, which couldn't be classified into the existing classification system. A 50-year-old man visited our hospital due to rhythmic dyskinesia of the right hand, which appeared during the resting state, and had developed one month after left subcortical infarction. Flexion and extension movements of the fingers at 3Hz appeared due to the impatient impulse to move. However, this abnormal movement could be easily suppressed under the patients will. We suggested that the abnormal movement was similar to akathisia from the fact that it occurred due to the internal desire to move and that the patient could suppress dyskinesia. However, the rhythmic tendency and lack of medication history of antipsychotics suggested that the movement was not the typical form of akathisia. The present case may represent a new clinical type of movement disorder developed after stroke. Considering the clinical pattern of the present case and following a review of the literature, we believe that it can be labeled, post-stroke rhythmic akathisia.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.5
• /
• pp.534-540
• /
• 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.

• Fisheries and Aquatic Sciences
• /
• v.5 no.3
• /
• pp.191-199
• /
• 2002

Pacific oysters Crassostrea gigas (Thunberg) were collected on April, 1999 and March­September, 2000 from Goseung Bay along the southern coast of Korea. The oysters tested cp;;ected from a depth of 0.5-2 m in which they cultured by a long line hanging method. The oxygen consumption rates (OCR) of oysters held under constant temperature and darkness (CC), were determined using an automatic intermittent-flow-respirometer (AIFR). Depending on holding periods after oyster collection, the experiments were divided into two groups: Group 7-d (held to ambient temperature for ca. 7 days) and Group 2l-d (held to ambient temperature for ca. 21 days). The OCR for Group 7-d single oyster displayed two peaks every day under CC, while Group 2l-d single oyster showed one peak every day. It is likely that the rhythmic patterns 02.6-12.8 hours) of the OCR in the Group 7-d single oyster may have been influenced by tidal currents at the sampling site. The rhythmic patterns (24.3-24.7 hours) in the Group 2l-d single oyster may have been shifted from two peaks to one peak each day under CC. The present study concludes that the OCR rhythm of wild oysters in nature is governed by two lunar-day clocks (24.8 hours); one driving one peak and the other driving the second peak. When oysters are subjected to the long-term CC conditions, one of the two-clock systems is depressed or only intermittently becomes active. Jpwever. the OCR rhythms by two to three oysters occurred arrhythmic patterns during the experiments and exhibited some evidence of weak rhythmicity of compared to those of a single oyster. It could be partly due to differences group effects.

• Journal of the Korean Society of Costume
• /
• v.24
• /
• pp.143-155
• /
• 1995

Unlike pure art such as painting and sculpture, dressmaking , a field of special plastic art, is characterized by its physical and functional nature. Having an inseparable relation with form, it is a field of art expressiion the human innersense of beauty in correlation with other various fields of art. In this respect, I think it should be necessary for us to study the forms of art from the past in order to study the forms of art from the past in order to study the correlations and mutual influencies between forms of pure art and dressmaking and to understand modern dressmaking from the standpoint of art. In this context, this study is an attempt to analze how the form and characteristics of OP ART , which represents the trends of the 1960's is embodied in modern dresses. The results are as follows : Fist , the expression of OP ART in dresses have visual effects harmonizing with bodily movements and , also, expanded the range and dynamics of expression which resulted from the introduction of visual phenomena in a fresh new sense by not limiting itself to the suggestion of patterns of OP ART. Second, OP ART paintings expressed the mobility and rhythimicity of a body in a limited space in a two-dimensional plane way of expression . When a dress is worn, however, it expands such mobility and rhythmicity in a cubic , three-dimensional way, maximizing the effects of , and boldly expression, OP ART, it can also create a new silhuette and ability of formation by seeking an open expression of OP ART rather than an expression of OP ART it self , due to the infinite possibility and unpredictability by the dynamics of movements and the elements principle of designs. Third , by applying the patterns of OP ART to dresses, we can obtain special visual effects of design, cover up the body's weak points, and create a desired three -dimensional sense by highlighting the beauty of the body's curved lines. Although modern dresses and OP ART are different genres of art, both have something in common in their pusuits. Since there is a infinite possibility in OP ART, there should be continuous attempts to combine dresses and art satisfying the sense of the times, which will lead dressmaking to a higher-dimensional dressmaking plastic art.

• The Korean Journal of Physiology and Pharmacology
• /
• v.10 no.1
• /
• pp.7-11
• /
• 2006

Interstitial cells of Cajal (ICCs) are pacemakers in gastrointestinal tracts, regulating rhythmicity by activating nonselective cation channels (NSCCs). In the present study, we investigated the general characteristics and pH-mediated regulation of pacemaker activity in cultured interstitial cells of Cajal. Under voltage clamp mode and at the holding potential of -60 mV, the I-V relationships and difference current showed that there was no reversal potential and voltage-independent inward current. Also, when the holding potentials were changed from +20 mV to -80 mV with intervals of 20 mV, there was little difference in inward current. In pacemaker activity, the resting membrane potential (RMP) was depolarized (In pH 5.5, $23{\pm}1.5$ mV depolarized) and the amplitude was decreased by a decrease of the extracellular pH. However, in case of increase of extracellular pH, the RMP was slightly hyperpolarized and the amplitude was decreased a little. The melastatin type transient receptor potential (TRPM) channel 7 has been suggested to be required for intestinal pacemaking activity. TRPM7 produced large outward currents and small inward currents by voltage ramps, ranging from +100 to -100 mV from a holding potential of -60 mV. The inward current of TRPM7 was dramatically increased by a decrease in the extracellular pH. At pH 4.0, the average inward current amplitude measured at -100 mV was increased by about 7 fold, compared with the current amplitude at pH 7.4. Changes in the outward current (measured at +100 mV) were much smaller than those of the inward current. These results indicate that the resting membrane potential of pacemaking activity might be depolarized by external acidic pH through TRPM7 that is required for intestinal pacemaking activity.

• Journal of Fashion Business
• /
• v.24 no.4
• /
• pp.117-129
• /
• 2020

Just as the name 'aesthetics' implies, the meaning of 'aisthesis' or 'sense' in Greek, is perceived as an important element in modern social design. Gilles Deleuze emphasized sensory expression over the rational side of the body, and argued for sensory theory, which is the theory of how painting produces new senses. The purpose of this study was to theoretically examine the sensory theory of Deleuze, which has given new value to the senses, apply it to analyze the body expression method shown in the Iris van Herpen collection, and derive its aesthetic characteristics. In his sensory theory, Deleuze argued that the senses can be expressed by the embodiment of force and rhythm, and one can only create art through the senses. To develop one's philosophical logic through Bacon's painting, we divided it into Hysteria, Cops sans organs, Diagram, Becoming, and Paired figures. Based on these analyses, the visualization of the senses in Iris van Herpen fashion resulted in hysteria, organ-free body, diagrams, and heterogeneity combinations. Analysis of the method of expression revealed rhythmicity, atypicality, scalability, and reproducibility as expression characteristics. Applying Deleuze's sensory theory to access experimental Iris van Herpen's fashion could confirm that there was an open system's accessibility. Deleuze's sensory theory, which has given a new value to the senses, will further help to understand modern fashion design in a wide and diverse way and discover the intrinsic value within it.

• Development and Reproduction
• /
• v.16 no.1
• /
• pp.53-58
• /
• 2012

Circadian rhythmicity (e.g. secretory pattern of hormones) plays an important role in the control of reproductive function. We hypothesized that the alteration of feeding pattern via meal time shift/restriction might disrupt circadian rhythms in energy balance, and induce changes in reproductive activities. To test this hypothesis, we employed simple animal model that not allowing $ad$ $libitum$ feeding but daytime only feeding. The animals of $ad$ $libitum$ feeding group (Control) have free access to food for 4 weeks. The day feeding (=reverse feeding, RF) animals (RF group) have restricted access to food during daytime (0900-1800) for 4 weeks. After completing the feeding schedules, body weights, testis and epididymis weights of animals from both group were not significantly different. However, the weights of seminal vesicle (control : RF group = $0.233{\pm}0.014g$ : $0.188{\pm}0.009g$, $p$<0.01) and prostate (control : RF group = $0.358{\pm}0.015g$ : $0.259{\pm}0.015g$, $p$<0.001) were significantly lower in RF group animals. The mRNA levels of pituitary common alpha subunit ($C{\alpha}$; control : RF group = $1.0{\pm}0.0699$ AU : $0.1923{\pm}0.0270$ AU, $p$<0.001) and $FSH{\beta}$ (control : RF group = $1.0{\pm}0.1489$ AU : $0.5237{\pm}0.1088$ AU, $p$<0.05) were significantly decreased in RF group. The mRNA levels of ACTH were not significantly different. We were unable to find any prominent difference in the microstructures of epididymis, and there were slight alterations in those of seminal vesicles after 4 weeks of reversed feeding when compared to control samples. The present study demonstrates that the shift and/or restriction of feeding time could alter the pituitary gonadotropin expression and the weights of seminal vesicle and prostate in rats. These data suggest the lowered gonadotropin inputs may decrease androgen secretion form testis, and consequently results in poor response of androgen-dependent tissues such as seminal vesicle and prostate.