• Fisheries and Aquatic Sciences
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• v.6 no.2
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• pp.51-58
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• 2003

The gonadal development and the gametogenic cycle and the fine structure of ripe germ cells of the cultured Pacific oyster, Crassostrea gigas were investigated using oysters monthly collected from the southern coast of Korea from October 2000 to September 2001. Monthly changes in the condition index were similar to that of meat weight rate and the highest value was observed in between April and May, and the lowest value in August. The external colors of the testis and the ovary were milky white and yellowish, respectively. The spawning period of the Pacific oyster was continued from May to September, with a peak in July. The gametogenic cycle could be classified into five successive stages: multiplicative stage (December to March), growing stage (March and April), mature stage (April to June), spawning stage (June to August) and resting stage (August to January). Variety of egg yolk granules, lipid granules, mitochondria, and endoplasmic reticula were observed in cytoplasm of ripe oocyte. The spermatozoon consisted of the head, middle piece and tail; including cap-shaped acrosome with domed structure, elliptical shaped nucleus, four mitochondria, two centrioles and flagellum.

• Animal cells and systems
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• v.3 no.4
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• pp.375-383
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• 1999

Gonadal development, gametogenesis, reproductive cycle, and first sexual maturity of Reishia clavigera were investigated monthly from July 1998 to June 1999 through cytological and histological observations. R. clavigera had separate sexes, and was an internal fertilizer. The ma1e penis was located near the two tentacles. The ovary and testis were composed of a great number of oogenic lobules and spermatogenic tubules, respectively. The size of ripe oocyte ranged from 130 to 140 ${\mu}$m in diameter. The peripheral cytoplasm of the germinal vesicle of the ripe oocyte in many cases were surrounded by smaller yolk granules, while the eccentric cytoplasm was occupied with larger ones. The reproductive cycle of R. clavigera could be classified into five successive stages: early active, late active, ripe, spawning, and recovery. Spawning of females occurred from early July to August when the seawater reached above 24.8$^{\circ}C$. Spawning of males occurred from early June to August in the water above 22.8$^{\circ}C$. Minimum size for sexual maturity of both sexes was above 10.0 mm in shell height. Each egg capsule was a cylinder or spindle in shape, 4-6 mm in length and 1-2 mm in width. Colors of newly spawned egg capsules showed yellowish white or pale yellow, while those with veliger larvae showed pale black, and released larvae or dead egg capsules showed black violet. The fecundity in an egg capsule ranged from 70 to 91 eggs (mean＝80.28 eggs).

• Korean Journal of Pharmacognosy
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• v.39 no.2
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• pp.123-126
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• 2008

The five flavonoids, isoqueritrin, juglanin, astragalin and 2-O-trans-p-coumaroyl astragalin were quantitatively analyzed in the leaves, unripe- and ripe fruits of four Korean Rubus species including Rubus crataegifolius, R. pungens var. oldhami, R. parvifolius, and R. coreanus belonging to the Rosaceae family. The HPLC analysis demonstrated that flavonoids are more abundant in the leaves than in the fruits. In the four Rubus species, ripe fruits generally contained similar or more amount of flavonoids than in unripe fruits. In particular, the quantity levels of total flavonoid (49.81${\pm}$0.50 mg/g) and isoquercitrin (35.08${\pm}$0.37 mg/g) were highest in the leaf of R. crataegifolius. In addition, the content of the flavonoids were quite low in the unripe fruits of R. coreanus that is most widely used as Rubi Fructus.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.787-804
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• 2018

Flavor quality is import for determining consumer perception and acceptance of tomato products. In this study, 'Fendou' tomato fruit were harvested at six ripening stages and sampled to investigate the development of flavor-relevant compounds during vine ripening. Results showed that upon the initiation of ripening there was an increase in respiration rate and concomitant ethylene evolution that was associated with increased membrane permeability. In accordance with these physiological changes, flavor-relevant compounds demonstrated different expression patterns as fruit ripened, which contributed to 'red-ripe' flavor characteristics of red-ripe fruit. Based on correlation analysis between ethylene evolution and the flavor-relevant compounds during 'Fendou' tomato ripening and the other researchers' reports, the activation of System 2-dependent autocatalytic ethylene production plays an important role in the development of most flavor-relevant compounds during tomato vine ripening. Overall, our results suggested that most flavor-relevant compounds that accumulated the most during tomato fruit ripening at red stage could be under ethylene regulation and were among the most important contributors to the 'red-ripe' flavor. Due to the development of these compounds, the flavor quality at late ripening stages is different from that of fruit at early ripening stages.

• Journal of The Korean Association For Science Education
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• v.40 no.6
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• pp.631-648
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• 2020

As an attempt to consider what to pay attention to in science learning, this study was conducted with the aim of discussing the meaning of science learning as a heterogeneous network. As a result of theoretical investigation, the characteristics of the heterogeneous network were described in three aspects: heterogeneous composition, existence by relations, and construction and change by translation. And it was discussed that science learning also has these characteristics of heterogeneous network. Relating to what to pay attention to in science learning, it was also discussed that science learning as a heterogeneous network requires us to pay attention to the elevation of things, the concept as a punctualized heterogeneous network, and the construction and expansion of heterogeneous network with neonadeuri of 'unripe' and 'ripe'. Finally, several suggestions for the science learning were given.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.15-18
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• 1984

This experiment was conducted to find out the factors governing the viviparous germination of In. $\times$ Ja. type rice varieties. Six varieties, i.e., Milyang 21, Raekyeong, Milyang 30, Yeongnamjosaeng, Nopoong and Mansuk, were used for this experiment. The viviparous germination easily occurred between 40 to 45 days after heading, and was easier in yellow-ripe stage or full-ripe stage than dough-ripe stage. The use of exceeding fertilization induced more viviparous germination than ordinary one. The early varieties such as Yeongnam-josaeng and Milyang 21, easily occurred the viviparous germination. The local conditions of viviparous germination were usually poorly drained soils and narrow alluvial valleys where were high humidity prevailed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.200-206
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• 1996

Experiment was conducted to get the information about physico-chemical properties of flue-cured tobacco on the degree of maturity cultivated in paddy-upland rotated field, and compared to upland ones. For the samples of this experiment, 3~4 leaves at each stalk position were harvested from the bottom of plants. Physico-chemical properties of cured leaves were determined from the samples collected at weekly intervals, and of obtained from 4 stalk positions. For the degree of maturity, harvested leaves were separated with visual characters into four classes such as immature, mature, ripe, and mellow. Regardless of stalk position, the order of shrinkage rate with length and width of leaves was mellow> immature> ripe> mature, and ripe leaves from paddy field showed higher shrinkage rate than those of upland. Nicotine and total nitrogen contents were decreased with the degree of maturity while reducing sugar content were showed a reverse tendency. Ripe leaves from paddy field had lower reducing sugar contents, comparing with upland tobacco. Filling capacity of cured leaves from paddy field was decreased with degree of maturity, but there was no difference between upland and paddy tobacco. Shatter index was increased in the oeder of immature > mellow > mature > ripe. Chemical components of cigarette smoke from paddy field tobacco were little higher in $CO_2$ total particulate matter and tar contents, while combustibility was little lower than that of upland tobacco. It was also evaluated that paddy field tobacco was unfavorable for the non-volatile organic and higher fatty acids contents comparing with upland tobacco.

• Journal of KIISE:Information Networking
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• v.31 no.5
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• pp.501-510
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• 2004

While the Internet keeps its permeation into every aspect of human life, two things stand out. One is the requirement for high quality of services to support multimedia data service.'The other is the desire for ubiquitous network connection. Combining the two things makes the Internet possible in supporting multimedia communications for nomadic users on the locomotion. To support QoS communication for mobile users by applying RSVP to Mobile IP, RSVP Tunnel, which specifies building separately a RSVP session between the home agent and the foreign agent, was proposed. However, the RSVP Tunnel method breeds bandwidth overhead and association problems in tunnel because of duplicated RSVP messages use. To resolve these problems, in this paper, we propose the new encapsulation method, the RSVP-in-IP Encapsulation (RIPE) that can support QoS guaranteed service efficicntly in Mobile IP networks. The proposed method supports RSVP mobility to Mobile If tunneling mechanism efficiently without any additional session as the RSVP Tunnel scheme. Moreover it removes the critical problems of bandwidth overhead in a tunnel and association by duplicated messages. We compared the performance of our proposed scheme with RSVP Tunnel scheme in term of mean delay, mean data rate and bandwidth overhead in tunnel.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.327-339
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• 1991

The present paper is a histological study of neurosecretory cells in the brain and the thoracic ganglion with the gonadal development in Palaemon serrifer. The reproductive cycle includes the successive stages of the growing period (February-March), the mature period(April-May), the ripe and spent periods(June-August) and the degenerative and resting periods(September-January). The neurosecretory cells are grouped into four types based on Matsumoto(1958) : A-,A'-, B- and E-cells. A- and A'-cells are $80-90{\mu}m,\;B-cell\;is\;30-40{\mu}m$ and E-cell is $10-15{\mu}m$. A- and B-cells are the positive to CHP and AF, while B-cell is the positive only to AF. The secretory grannules of a A-cell are transported to the axon, and at the same time they are discharged through the peripheral membrane. Of the four neurosecretory cells, A- and I-cells show the difference of secretory activity according to the gonad developmental process. In the female, A-cells show secretory activity for the ripe and spent periods, while I-cells show for the mature, ripe and spent periods. In the male, A-cells show secretory activity for the mature, ripe and spent periods, while I-cells show for the growing, mature, ripe and spent periods.

• The Korean Journal of Malacology
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• v.20 no.1
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• pp.85-92
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• 2004

We investigated the reproductive cycle with gonadal development of the female Cyclina sinensis by histological observations and seasonal changes in biochemical components of the adductor muscle and visceral mass tissues were studied by biochemical analysis, from January to December, 2001. The reproductive cycle of this species can be classified into five successive stages: early active stage (February to April), late active stage (March to June), ripe stage (May to August), partially spawned stage (July to October) and spent/inactive stage (September to February). Total protein contents in the adductor muscle tissues reached the maximum in February (early active stage) and appeared the minimum in June (ripe stage), while their contents in the visceral mass tissues reached the maximum in the late active and ripe stages (June) and gradually decreased from July (partially spawned stage) to November (spent/inactive stage). Changes in total protein contents showed a negative correlationship between the adductor muscle and visceral mass tissues (r = -0.499, p = 0.099). Total lipid contents in the adductor muscle tissues reached the maximum in January (the inactive stages) and their contents gradually decreased from February. Their contents in the visceral mass tissues, however, reached the maximum in June (late active and ripe stage) and gradually decreased from July (the partially spawned stage). On the whole, total lipid contents showed a negative correlationship between the adductor muscle and visceral mass tissues (r = -0.631, p < 0.05). Therefore, These results indicate that the nutrient contents of the adductor muscle and visceral muscle tissues change in response to gonadal energy needs. Glycogen contents in the adductor muscle tissue reached the maximum in March (early and late active stages) and decreased from July to September (partially spawned stage). while their contents in the visceral mass tissues reached the maximum in June (late active and ripe stages) and gradually decreased from July (partially spawned stage). Thereafter, their levels gradually increased in November (spent/inactive stage). On the whole, changes in glycogen contents appeared negative correlationship between the adductor muscle and visceral mass tissues. However, they showed no significant different (r = -0.307, p = 0.331).