• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.158-163
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• 1998

This paper is our first attempt to construct a information processing system such as the living creatures' brain based on artificial life technique. In this paper, we propose a method of constructing neural networks using bio-inspired emergent and evolutionary concept, Ontogeny of living things is realized by cellular automata model and Phylogeny that is living things adaptation ability themselves to given environment, are realized by evolutionary algorithms. Proposing evolving cellular automata neural systems are calledin a word ECANS. A basic component of ECANS is 'cell' which is modeled on chaotic neuron with complex characteristics, In our system, the states of cell are classified into eight by method of connection neighborhood cells. When a problem is given, ECANS adapt itself to the problem by evolutionary method. For fixed cells transition rule, the structure of neural network is adapted by change of initial cell' arrangement. This initial cell is to become a network b developmental process. The effectiveness and the capability of proposed scheme are verified by applying it to pattern classification and robot control problem.

• Neonatal Medicine
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• v.25 no.1
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• pp.1-6
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• 2018

Extremely low birth weight infants remain at increased risk of intraventricular hemorrhage from the fragile vascular bed of the germinal matrix; the roles of hypotension (ischemia) and reperfusion (hyperemia) in the development of intraventricular hemorrhage are still debated. Cerebrovascular pressure autoregulation protects the brain by maintaining constant cerebral blood flow despite changes in blood pressure. The ontogeny of cerebrovascular pressure autoregulation has not been well established and uncertainty remains about the optimal arterial blood pressure required to support brain perfusion. Another important aspect of premature cerebral hemodynamics is the critical closing pressure--the arterial blood pressure at which cerebral blood flow ceases. Interestingly, in premature infants, the critical closing pressure approximates the mean arterial blood pressure. Often in this unique population, cerebral blood flow occurs only during systole when the diastolic arterial blood pressure is equal to the critical closing pressure. Moreover, the diastolic closing margin, a metric of cerebral perfusion that normalizes diastolic arterial blood pressure to the critical closing pressure, may be a better measure than arterial blood pressure for defining cerebral perfusion in premature infants. Elevated diastolic closing margin has been associated with intraventricular hemorrhage. This review summarizes the current state of understanding of cerebral hemodynamics in premature infants.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.107-110
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• 2008

A high-efficiency, reproducible somatic embryogenesis system for strawberry cultivar Chandler was developed. Thirty-one somatic embryos per explant(max no.) were recorded in leaf discs which were cultured on medium containing MS salts+$B_5$ vitamins+2% glucose+4.0 mg $1^{-1}$TDZ(Thidiazuron) and incubated at $10{\pm}1^{\circ}C$ under darkness for one week followed by three weeks under 16-h photoperiod. The scanning electron microscopic(SEM) ontogeny revealed the normal development of somatic embryos from globular to heart-shaped and dissection microscopy from torpedo-shaped to cotyledonary-stage embryos. The maximum germination percentage of 48% could be obtained on MS medium containing kinetin(1.0 mg $1^{-1}$) and the maximum survival percentage(79%) of plantlets after four weeks was found to be in the mixture of vermiculite, peatmoss, and soilrite(1:1:1).

• Journal of Plant Biology
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• v.35 no.4
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• pp.359-364
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• 1992

The vascular cambium in Ginkgo biloba seedling began to differentiate in the cotyledonary node, and then the differentiation proceeded bidirectionally from the cotyledonary node toward the stem and root. In tangential view, procambium at the early developmental stage was a homogeneous structure consisted of almost similar cells in shape, and at the later stage the procambium became a heterogeneous one consisted of long cells and short cells. Such a differentiation pattern in the cotyledonary node was similar to that in the stem. However, it was different from that in the root. Fusiform initials and ray initials consisting the vascular cambium were originated from the long cells and the short cells, respectively. The long cells and the fusiform initials in the cotyledonary node were shorter and wider than those in the first internode.ernode.

• Fisheries and Aquatic Sciences
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• v.16 no.1
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• pp.25-34
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• 2013

Early ontogenic development in Siberian sturgeon Acipenser baerii was documented and the effects of different temperatures on embryonic and prelarval development were examined. Photograph-assisted data on morphogenesis in Siberian sturgeon prolarvae agreed well with published descriptions of their ontogeny and ecological behaviors, although certain aspects of differentiation, such as gill covering and scute development, could be rearing condition-sensitive. The present study provides the first characterization of the transient development of teeth during early larval stages; the pattern was congruent with the transition of prolarvae to exogenous feeding. From examinations of embryonic and prelarval development under different temperature conditions ($12-24^{\circ}C$), developmental speed was inversely related with temperature. Overall, hatchability was higher and hatching events were more synchronized at $20^{\circ}C$ than at lower temperatures. After hatching, similar patterns of temperature-dependency were observed in yolk sac absorption and the evacuation of the pigment plug. Our results suggest that the incubation of Siberian sturgeon embryos and prolarvae at temperatures close to $20^{\circ}C$ would be advantageous in hatcheries, based on reductions in the duration and uniformity of egg and prolarval developmental stages.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.513-519
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• 1996

The development of calcitonin, serotonin(5-HT) and bovine chromogranin (BCG)-immunoreactive cells was investigated in the thyroid glands of Korean native goat from fetus to adult, using an immunohistochemical method. Moderate number of calcitonin-immunoreactive cells were present in the thyroid glands from 1 month to 6 months after birth, whereas a few in the adult. They were not present in the thyroid glands of fetus and 1 day after birth. A number of 5-HT- and BCG-immunoreactive cells were present in the thyroid glands of Korean native goat from fetus to adult. They were increased in number with age. BCG-immunoreactive cells were weakly reacted in fetus and 1 day after birth, while these cell were strongly stained from 1 month to adult. These findings suggest that calcitonin-, 5-HT- and BCG-immunoreactive cells were present in the thyroid gland of Korean native goat.

• Journal of Plant Biology
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• v.37 no.3
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• pp.317-323
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• 1994

The calluses formed on the surface of a quarter-girdled Robinia pseudoacacia stems have been shown to originate from immature xylem cells and preexisting cambial cells. The cellus is not only formed by periclinal and anticlinal divisions of radial cells, but also axial cells. In tangential view, the callus at initial stage showed heterogeneous structure composed of long and short cells and then homogeneous one with short cells. Some cells of homogeneous structure in middle region of callus at early stage is later elongated and others mainly divided in trasverse plane. In the result the homogeneous structure becomes into a heterogeneous one. Subsequently, the long cells in heterogeneous structures elongated further and became fusifrom initials, and the short cells divided transversely became ray initials. The appearence of homogeneous and heterogeneous structure in the callus on debarked stem without organ elongation is almost similar to that of the structure in the procambium of young stem which is elongating extensively. Eventually, the ontogeny of vascular cambium in wound callus resembles that of a young stem grown normally, although the debarked stem does not grow in length but in girth and the young stem elongates activity. These findings mean that the active intrusive growth of short procambial cells occurs during the differentiation of fusiform cambial cells.

• Korean Journal of Plant Resources
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• v.28 no.3
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• pp.350-356
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• 2015

Abeliophyllum distichum is a monotypic taxon of Oleaceae and endemic to Korea. A comprehensive study on embryogeny and fruit and seed coat ontogeny in Abeliophyllum was carried out via microtome and light microscopy. The fertilization occurs during mid– to late April and embryo matures by early July. The embryo development follows the general fashion from globular embryo – transition embryo – heart shaped embryo – torpedo embryo – walking-stick embryo to mature embryo. The pericarp clearly differentiates into three histological zones: exocarp, mesocarp, and endocarp. The young seed comprises 10-12 cells thick seed coat and the mature seed coat comprises an exotesta, 6-8 mesotesta and an endotesta. Any crystals, phenolic-like compounds, idioblasts, and the sclereids are not found in pericarp as well as seed coat. An overall development confirms Solanade type of embryogenesis in Abeliophyllum. The endocarp becomes more prominent in mature fruit and all the layers of endocarp are highly lignified. On the basis of mechanical layer the seed coat is of exotestal type.

• Clinical and Experimental Pediatrics
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• v.50 no.8
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• pp.711-717
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• 2007

Sleep is a vital, highly organized process regulated by complex systems of neuronal networks and neurotransmitters. Normal sleep comprises non-rapid eye movement (NREM) and REM periods that alternate through the night. Sleep usually begins in NREM and progresses through deeper NREM stages (2, 3, and 4 stages), but newborns enter REM sleep (active sleep) first before NREM (quiet sleep). A period of NREM and REM sleep cycle is approximately 90 minutes, but newborn have a shorter sleep cycle (50 minutes). As children mature, sleep changes as an adult pattern: shorter sleep duration, longer sleep cycles and less daytime sleep. REM sleep is approximately 50% of total sleep in newborn and dramatically decreases over the first 2 years into adulthood (20% to 25%). An initial predominant of slow wave sleep (stage 3 and 4) that peaks in early childhood, drops off abruptly after adolescence by 40% from preteen years, and then declines over the life span. The hypothalamus is recognized as a key area of brain involved in regulation of sleep and wakefulness. The basic function of sleep largely remains elusive, but it is clear that sleep plays an important role in the regulation of CNS and body physiologic processes. Understanding of the architecture of sleep and basic mechanisms that regulate sleep and wake cycle are essential to evaluate normal or abnormal development of sleep pattern changes with age. Reduction or disruption of sleep can have a significant impact on daytime functioning and development, including learning, growth, behavior, and emotional regulation.

• Animal cells and systems
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• v.3 no.1
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• pp.97-102
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• 1999

In order to investigate the regional distribution and relative frequency of the serotonin-, somatostatin- and motilin-immunoreactive cells in the gastrointestinal tract GIT) of the bullfrog (Rana catesbeiana) with developmental stages, group of bullfrogs subdivided into the tadpole with hindlegs, metamorphosed bullfrog with tail, 2 wk after metamorphosed bullfrog and adult bullfrog, were stained by immunohistochemical methods (PAP methods). Multifarious changes of the regional distribution and relative frequency of the gastrointestinal endocrine cells were observed as developmental stages but motilin-immunoreactive cell ere not detected in this study. Serotonin-immunoreactive cells were detected from 2 wk after metamorphosed bullfrog in the whole GIT. The positive cells were predominant in the pylorus regions. In the adult bullfrog, these cells increased in fundus. On the other hand, somatostatin-immunoreactive cells were observed from the tadpole with hindlegs in the stomach regions. In the metamorphosed bullfrog with tail, they were found in the whole GIT except for the ileum, and increased with developmental stages except for rectum. In the rectum, these cells were not detected after that period. Our results show that most of the immunoreactive cells appear from completed metamorphosed periods when the histological structure of GIT is completely differentiated.