• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.6
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• pp.73-76
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• 2004

This study was conducted to investigate the growth responses of Polystichum lepidocaulon as influenced by 4 different shadings(Control, 50%, 70%, 90%). Under 50 or 70% shading, plant height, stipe length, blade length, blade width, and number of spores increased compared with the other shadings, except the number of frond and shoots. The plants grown under control was shown as smaller with more yellowish green leaf color, and under 90% shading the growth was slightly inferior to those under the 50 or 70% shading. Fresh weight and segment area of frond was better in increased shade levels, but they decreased in under 90% shading. Dry weight and segment thickness decreased as shading increased. Chlorophyll contents increased in proportion to lowered light intensity. Thus, 50 or 70% shading of Polystichum lepidocaulon seemed to maintain the highest growth.

• Applied Microscopy
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• v.30 no.2
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• pp.233-240
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• 2000

Aspects of structural differentiation of the free -floating hydrophyte, Spirodela polyrhira, has been investigated. The hydrophyte exhibited highly reduced structures having only fronds, connective stalks, and roots as a mature plant. The fronds were major photosynthetic and vegetatively reproducing organ during the growth. Daughter fronds which developed early in the mother frond were also chlorenchymatous, but they remained within foliage sheaths of the mother frond before separation from connecting stalks. Although the stalks and roots originated from the same meristematic region of the frond, they exhibited the distinct polarity showing former lateral growth and latter axial growth. Air chambers were formed only in the fronds and roots. Cellular components were scattered throughout the diffuse cytoplasm in most of the actively growing stalk cells. Root cells protected by the root cap demonstrated relatively complex organization, showing dense cytoplasm with Golgi, rER, mitochondria, and chloroplasts in the cortical cells. Cells in the root cap were highly vacuolated within the peripheral cytoplasm. Such reduction and differentiation of the plant body in Spirodela polyrhiza most effectively contributes to the better adaptation of smaller plants to superficial aquatic environments, while also enabling the rapid growth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.6
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• pp.439-442
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• 1990

We have examined harpacticoid copepods inhabiting the phaeophyte Miyok, Undaria pinnatifida (Harvey), on the southern coast of Korea and cultured in the laboratory pieces of Miyok frond heavily infested by frond-mining nauplii to identify the harpacticoid copepod to which those nauplii belong. Of the harpacticoids found in Miyok-washings, only Amenophia orientalis Ho and Hong and an unidentified species of the genus Scutellidium occurred consistently in all Miyok samples examined. Many females of both species carried egg sacs. In the cultures the frond-mining nauplii developed, in 15 days at$15^{\circ}C$, into cope-podid stages or adults that were all identified with Amenephia orientalis. It is therefore concluded that this species is the causative agent for the so-called pinhole disease of the cultivated Miyok on the southern coast of Korea, which is diagnosed by the appearance on the thallus of numerous pinholes occupied by developing nauplii.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.465-469
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• 2013

In this study, we investigated the feasibility of torrefied OPF (oil palm fronds) as the fuel. The torrefaction was performed at 200, 250, 300 and $350^{\circ}C$ during 1 and 2 hours, respectively. As raising the torrefaction temperature and increasing the processing time, the GHV (gross heating value) of torrefied OPFs was increased. Moreover, we found that the torrefaction temperature is more important factor than the processing time. However, the proper torrefaction temperature was asked because the higher torrefaction temperature leaded to the lower torrefied OPF yield. TGA (thermo-gravimetric analysis) data released that the torrefaction at $250^{\circ}C$ could significantly decompose the hemicellulose and the almost cellulose was decomposed at $300^{\circ}C$. In addition, the grindability of biomass was improved after torrefaction, so that it can reduce energy consumption in comminution.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.510-515
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• 2014

Duckweed (Lemna perpusilla J. Torrey) is a typical floating aquatic macrophyte that has been used for evaluating phytotoxicity of toxicants. In this study, we evaluated the responses of duckweed to PAHs and ammonium as toxicants that frequently affect the growth of plants in polluted industrial and agricultural areas. As the duckweed is growing in aquatic environment, the PAHs and ammonium were incorporated into nutrient solution and the fronds were cultured hydroponically. Frond growth was responded differentially to the concentration and type of PAHs. The severe inhibition of frond growth was observed in the treatment of fluorene. Fluoranthene and pyrene, however, showed weak inhibition of frond growth. The latter PAHs that showed weak inhibition did not reduced frond number at the low concentration of 30 ppm. Pigment contents were also responded differentially. Phenanthrene and fluorene reduced chlorophyll content more strongly than fluoranthene and pyrene. Carotenoids, well-known antioxidative compound, was relatively increased at the low concentration of PAHs up to 30 ppm by the treatment of fluoranthene and pyrene, suggesting an increased antioxidative activity in fronds. Ammonium treatment showed higher inhibitory effect even low concentration of 3 mM.

• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.553-557
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• 2000

Fatty acid composition of frond, spororphyll and stipe of Miyeok (Undaria pinnatifida) were extensively analyzed to evaluate a nutrient significance of n-3 polyenes, n-6 polyenes, ${\gamma}$-linolenic acid (18:3, n-6) and $\alpha$-linolenic acid (18:3, n-3). Polyenes of $\alpha$-linolenic acid (22:6, n-3), stearidonic acid (18:4, n-3), eicosapentaenoic acid (20:5, n-3) and docosahexaenoic acid (22:6, n-3) were as high as 29.69%, but ${\gamma}$-linolenic acid (18:3, n-6) was as low as 0.90% when compared to total polyenes of 44.18% in frond. The n-3 polyenes of neutural lipids, glycolipids and phospholipids were 22.40%, 35.82% and 3.53% in frond, 5.26%, 9.51% and 2.37% in stipe and 8.01%, 4.49% and 2.14% in sporophyll, respectively. These results suggest that total polyenes and n-3 polyenes in frond of Miyeok may be used as resource of functional food.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.941-947
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• 2000

Three fistulated Malaysian local bulls were used in a $3{\times}3$ Latin square design to determine the effects of different levels of concentrate with oil palm (Elaeis guineensis Jacq.) frond (OPF) on rumen pH and $NH_3$-N concentration, and DM degradability of different fractions of OPF. Three diets namely, 60% OPF pellet and 40% concentrate (Diet 1), 50% OPF pellet and 50% concentrate (Diet 2) and 40% OPF pellets and 60% concentrate (Diet 3) were used. The levels of concentrate in the diets affected rumen pH and $NH_3$-N concentration. The pH and $NH_3$-N concentration almost in all hourly samples did not show any difference (p>0.05) among the diets except the 6 h and 9 h samples. The highest (p<0.01) $NH_3$-N concentration was obtained on Diet 3 followed by Diet 2 and Diet 1, but there was a slightly higher (p>0.05) pH on Diet 1. The $NH_3$-N concentrations of rumen liquor at 9 h sampling on Diet 1 and Diet 2 were below the critical level (50 mg/liter) required for efficient fermentation of fibrous feeds. The in sacco DM degradation of different fractions of OPF was affected by diets. The DM degradation of fractions of OPF was higher on Diet 3, which showed differences (p<0.01) with the other diets. It was found that a higher level of concentrate (60%) with OPF gave a higher rumen $NH_3$-N concentration that increased the DM degradation of OPF fractions. The results showed that OPF could support an efficient rumen function in terms of $NH_3$-N concentration and pH when ${\leq}50%$ in the diet. A higher level of OPF (>50%) does not support an efficient rumen fermentation in terms of $NH_3$-N concentration, and resulted in lower DM degradation values of the fractions. The results suggested that there is a need to supplement additional nitrogen to OPF based diets.

• Korean Journal of Medicinal Crop Science
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• v.21 no.4
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• pp.301-305
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• 2013

This study was performed to select adequate plant materials for developing a natural ${\alpha}$-glucosidase inhibitor by analyzing ${\alpha}$-glucosidase inhibition activity in fronds and rhizomes of three Dryopteridaceae species: Cyrtomium fortunei, Polystichum polyblepharum, and P. lepidocaulon. The highest ${\alpha}$-glucosidase inhibitor obtained from frond of P. lepidocaulon ($4.16{\mu}g{\cdot}mL^{-1}$), and rhizome of C. fortunei ($1.84{\mu}g{\cdot}mL^{-1}$), showed much higher inhibition activity than acarbose ($1413.70{\mu}g{\cdot}mL^{-1}$). The biomass required to inhibit ${\alpha}$-glucosidase by 50% was 0.04 ~ 0.35mg for frond and 0.03 ~ 0.10mg for rhizome, and P. lepidocaulon required the least amount of fronds and P. lepidocaulon the least rhizomes. In frond, ${\alpha}$-glucosidase inhibition activity was the highest in water fraction of C. fortunei ($20.2{\mu}g{\cdot}mL^{-1}$), and n-butanol fraction of P. lepidocaulon ($9.33{\mu}g{\cdot}mL^{-1}$) and P. polyblepharum ($5.10{\mu}g{\cdot}mL^{-1}$). In rhizome, it was the highest in n-butanol fractions of C. fortunei ($19.76{\mu}g{\cdot}mL^{-1}$) and P. polyblepharum ($4.47{\mu}g{\cdot}mL^{-1}$), and ethylacetate fraction of P. lepidocaulon ($5.46{\mu}g{\cdot}mL^{-1}$). The frond biomass required for 50% ${\alpha}$-glucosidase inhibition was the lowest in the water fraction of C. fortunei (1.43mg), and n-butanol fractions of P. lepidocaulon (1.10mg) and P. polyblepharum (0.66mg). The required biomass of rhizome was the lowest in the water fraction of C. fortunei (1.59mg), and n-hexane fractions of P. lepidocaulon (0.04mg) and P. polyblepharum (0.15mg). The result of this study suggested that the three Dryopteridaceae species had high ${\alpha}$-glucosidase inhibition activity with small biomass, which might have high value as materials for economical anti-diabetic medication.

• ALGAE
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• v.18 no.2
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• pp.129-134
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• 2003

In order to examine the effects of deep seawater (mesopelagic water in the broad sense) on the growth of macroalgae, the growth and nutrient uptake (nitrate and phosphate) of Ulva sp. (Ulvophyceae, Chlorophyta) were investigated by cultivation in deep seawater (taken from 687 m depth at Yaizu, central Japan, in August 2001), surface seawater (taken from 24 m depth), and a combination of the two. Culture experiments were carried out in a continuous water supply system and an intermittent water supply system, in which aerated 500-mL flasks with 4 discs of Ulva sp. (cut sections of ca. 2 $cm_2$) were cultured at 20$^{\circ}C$ water temperature, 100 $\mu$mol photons $m^{-2}{\cdot}s^{-1}$ light intensity, and a 14:10 light:dark cycle. Nutrient uptake by Ulva sp. was high in all seawater media in both culture systems. The frond area, dry weight, chlorophyll a content, dry weight per unit area, and chlorophyll a content per unit area of Ulva sp. at the end of the experimental period were the highest in deep seawater and the lowest in surface seawater in both culture systems. These values, except for dry weight per unit area and chlorophyll a content per unit area, for each seawater media in the intermittent water supply system were higher than those in the continuous water supply system. We conclude that not only deep seawater as the culture medium but also the seawater supply system is important for effective cultivation of macroalgae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.3
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• pp.165-170
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• 1981

Recently an unknown microbial desease and some parasitic crustaceans are prevailing in the sea-weed farms of Uudaria pinnatifida along the south-eastern coast of Korea.(1) Green spots probably caused by the microbial pathogens were found on the fronds of Undaira Pinnatifide. Particularly they were densely distributed on the distal half of the fronds. The tissues of the green spot area rot off, and small holes with green colored margin are formed. The holes at the distal part of the fronds are enlarged and they finally coalesced each other. Then this process accelerates decaying of the distal ends of the fronds.. The fronds growing in the central part of the farms are usually severely damaged, whereas in the marginal area of the farm toward the open sea side the damage is less serious. An examination revealed that the deseased fronds bore a number of viable bacteria, $6.8\times10^5\;to\;1.2\times10^6$ per gram at $15^{\circ}C$, whereas the healthy fronds $1.1\times10^4$. Twenty-six kinds of colonies, 247 strains of bacteria, were isolated from deseased fronds, belonging to Moraxella, Achromobacter, Vibrio, Flavobacterium, Acinetobacter, Pseudomonas, etc. (2) Pinholes occurred in one series on the frond. They were probably caused by a harpacticoid copepod, Thalestris sp. Seven years ago when the disease was first found to occur the copepod was observed on the fronds from March of the year. Recently, however, they have been found as early as December of the previous year. (3) A gammarid amphipod, Ceinina iaponica, invades the pith of the midrib through holdfast of thalli. This rarely causes the longitudinal seperation of the entire frond through the midrib as they bore a tunnel in the pith. Sometimes holdfasts of tile heavy damaged thalli make the frond departed from the substrate.