• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.1
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• pp.8-15
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• 2004

Purpose: This study was conducted to identify potential dangers involved in procedure and evaluate complications of percutaneous endoscopic gastrostomy (PEG) comparing to surgical gastrostomy (SG). Methods: A retrospective study of 66 children with feeding gastrostomy between 1994 and 2002 was done. Results: Of 66 children, 23 (mean age 29 months) had PEG and 43 (mean age 49 months) had SG. 31 cases of SG group had fundoplication for gastroesophageal reflux disease. PEG groups were followed up with an average 13 months and SG groups with 21 months. Major complications occurred in 33% of PEG group (8/23) and 55% of SG group (24/43). Major complications were significantly lower in PEG group than SG group and minor complications, too (p<0.05). Of major complications, aspiration pneumonia was the most common but paralytic ileus was significantly higher in SG group than PEG group. 8 patients died of underlying disease but not related to gastrostomy. Removals of stomata were done in 5 of PEG group and 3 of SG group. GER recurred in 25% of SG group with fundoplication and newly developed in 17% of SG group. GER persisted in 17% and newly developed in 5% of PEG group. Conclusion: The gastrostomy was a significant procedure with the potential to produce complications. PEG is recommended as an initial procedure in children requiring a feeding gastrostomy but should be considered a major undertaking.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.300-307
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• 2006

To clarify the morphological and geographical differentiation among the polyploid complexes of L. lancifolium collections in Korea, the mo게hological variation of 173 accessions were analyzed by ANOVA (one-way analysis of variance) and PCA (principal component analysis) on the basis of 38 morphological characters. 173m accessions were grouped into 78 diploids and 95 triploids by ploid levels and the triploids separated into 75 inland triploids (all around the Korea) and 20 island triploids (Backryung-do and Sochung-do, westemmost and northernmost islands of Korea) by geographic distribution and morphology. Island triploids showed significant morphological differences with inland triploids in ANOVA by many floral and leaf characters. In PCAs, diploids were separated from inland triploids by having longer plant height, smaller flower characters, higher pollen fertility and more stomata. The first four principal components accounted for 44.1% of the total variation. Plots of the island and inland groups for the first and second principal components separated each other with slight overlapping. Although the ploid forms are different between diploid and island triploid, island triploids were more closely overlapped with diploids by principal component 1 and 2 than inland triploids. This reflects that the whole external morphology of island triploids are similar to that of diploids. This, the phenotypic differentiation between inland and island triploids seems to be partly related to their geographical origins.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.1
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• pp.49-53
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• 1979

Effects of temperature and light intensity on photosynthesis, respiration and chlorophyll content of ginseng (Panax ginseng C. A. Meyer) were as follow. 1. Optimum light intensity for apparent photosynthesis at $25^{\circ}C$ was 25Klux($1.35mgCO_2/dm^2{\cdot}hr$) for two years old ginseng grown in pot and 30Klux($1.94mgCO_2/dm^2{\cdot}hr$) for the six years old palmate cut leaves. Optimum temperature at 25Klux was $15^{\circ}C$ ($1.40mgCO_2$) for the 2 years old and 20 to $22^{\circ}C$ ($2.03mgCO_2$) for the 6 years old. 2. Dark respiration increased almost linearly with the increase of air temperature till $25^{\circ}C$ (2.6times between $16^{\circ}C$ to $25^{\circ}C$ for the 6 years old and 1.8 times between $15^{\circ}C$ to $25^{\circ}C$ for the 2 years old). Dark respiration was 11.1 % of net photosynthesis at $16^{\circ}C$, 17.8% at $25^{\circ}C$ for the 6 years old and 40% at $15^{\circ}C$, 64.7% at $25^{\circ}C$ for 2 years old. 3. Stomata appeared only in abaxial surface (lower epidermis) and stomatal frequency was $37per\;mm^2$. 4. Above results together with other informations quoted here strongly suggest that air temperature is much better criteria than light intensity for the improvement of shading roof material and shading construction. That is to promise maximum light intensity unless air temperature is above $25^{\circ}C$.

• Journal of Korean Society of Forest Science
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• v.40 no.1
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• pp.1-18
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• 1978

Three Pinus densiflora populations as shown in location map (Fig. 1) were studied in 1977. These succeed the population numbers 10, 11 and 12 after the preceeding populations. Following the previous study methods, 20 trees were chosen from each population and the morphological characteristics such as tree forms, branching habit, needle and wood properties were investigated. The results are summerized as follows; 1. The mean stand ages were ranged from 40 to 45. The growth performances of trees of population 10 and 11 was similar, but 12 seemed to be inferior more or less. 2. The ratios of clear bole length was 0.53 in population 12 as the highest but 0.43 for population 10 as the lowest. 3. The population 12 was considered to be a stand of the coarser branching habit having the crown index (The maximum crown diameter/the crown length) 1.65 though the mean branching angle indicates almost horizontal. 4. The differences were observed in the clear bole length ratios and crown-indices between populations as shown in Fig. 3 and 4. 5. No inter-population differences in serration density of needle was shown but significant inter and intra-population and individual differences (within population) in number of stomata rows and resin duct. 6. Population 12 shown 0.119 of resin duct index as the maximum. 7. The pattern of diameter growth, analyses based on the width of 10-year-ring segment unit (for example, the 1st segment denotes the width between pith center and 10th year ring and the 2nd one is from 11th to 20th year ring and so on.), was alike among populations as shown in Fig. 9. 8. No significant differences between population in mean summer wood percentages as well as in wood specific gravity was observed. The values of wood specific gravity were increased with the increase of ages in population 10 and 11 however vice versa in population 12. 9. The fiber length was increased with the increase of age but no differences between populations as shown in Fig. 12.

• Journal of Korean Society of Forest Science
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• v.44 no.1
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• pp.1-25
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• 1979

Six natural populations of Pinus densiflora S. et Z. as shown in the location map (Flg 1) were studied during 1978. The numerial pouplation codes, 13 to 18. The results of populations 1 to 12 were reported in previous papers. Following the study methods described before, 20 trees were sampled from each population and morpological characteristics such as stem forms, branching habit needle and wood properties investigated. The results are summerized as follows; 1. The mean stand ages were ranged from 36 to 97 of years. The growth performances of trees of population 14. 15 and 18 was similar, but 13, 16, and 17 seemed to be inferior more or less. 2. The ratios of clear bole length were 0.70 in population 18 as the highest but 0.28 for population 16 as the lowest. 3. The population 17 was considered to be a stand of the coarser branching habit having the crown index (The maximum crown diameter/the crown height) 158 though the branching angles were almost horizontal. 4. The differences were observed in the clear bole length ratios and crown-indices between population as shown In Fig. 3 and 4. 5. As to the serration density, number of stomata row and resin duct; the significant differences exist between individual trees within population and also between populations. 6. Population 18 shown resin duct index 0.119 as the maximum. 7. The patterns of diameter growth, based on the width of 10-year-ring segment unit(for example, the 1st segment denotes the with between pith center and 10th year ring and the 2nd one is from 11th to 20th ring and so on.), were alike among populations as shown in Fig 9. 8. Significant differences between population in mean summer wood percentage as well as in wood specific gravity was observed. The values of wood specific gravity were increased with the increase of ages in population 14, 18 however vice versa in population 13, 15, and 17. 9. The fiber length was mereased with the increased of age but no differences between populations as shown in Fig. 12.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.199-212
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• 2014

The physiological responses of three common temperate species, Pinus densiflora, Fraxinus rhynchophylla, Sorbus alnifolia to elevated $CO_2$ was investigated using open top chambers with different $CO_2$ concentrations. Morphological (stomatal size, density and area) and physiological characteristics (maximum rates of photosynthesis, carboxylation and electron transport) were compared among trees grown under ambient, ambient ${\times}1.4$ (~550 ppm) and ambient ${\times}1.8$ (~700 ppm) $CO_2$ concentrations for last four years. Morphological responses were different among species. F. rhynchophyllar increased their stomatal size and S. alnifolia had higher stomatal density under elevated $CO_2$ than ambient. Stomatal area decreased in P. densiflora, whereas it increased in S. alnifolia. However, the maximum photosynthesis rate increased in all species up to 43.5% by S. alnifolia under elevated $CO_2$ and the enhancement increased with time. Even with four years of exposure to elevated $CO_2$, there was no sign of acclimation in the maximum carboxylation rate and the maximum electron transport rates in all species. Especially, S. alnifolia even showed the temporary increase of photosynthetic capacities in spring, when leaf nitrogen concentration was high with new leaf development. There was no significant differences in diameter growth rate in any species due to high variation in their tree sizes, however accumulated diameter and biomass for four years showed significantly increment in all species under elevated $CO_2$. For example, S. alnifolia showed 59% increase in diameter at the ambient ${\times}1.8$ (~700 ppm) compared to ambient.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.2
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• pp.51-59
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• 2017

This study evaluated the drought tolerance of Liriope platyphylla F.T.Wang & T.Tang, Dendranthema zawadskii var. lucidum (Nakai) J.H.Park, Hosta longipes (Franch. & Sav.) Matsum., Sedum sarmentosum Bunge and Zoysia japonica Steud. for an extensive green roof. In order to assess drought tolerance of green roof plants, several criteria were measured such as volumetric water content, leaf and soil moisture potential, chlorophyll a and b, chlorophyll fluorescence, photosynthesis, stomatal conductance, transpiration rate and antioxidants. The results of the drought tolerance measurement of green roof plants focused on the gradually withering of plants from lack of volumetric water content. D. zawadskii was the first to show an initial wilting point, followed by Z. japonica, H. longipes and L. platyphylla in order while S. sarmentosum showed no withering. It was concluded that H. longipes, L. platyphylla and S. sarmentosum were highly drought tolerant plants able to survive over three weeks. Furthermore, chlorophyll a and b were divided into two types: Type I, which kept regular content from the beginning to the middle of the period and suddenly declined, like H. longipes and Z. japonica; and Type II, which showed low content at the beginning, sharply increased at the middle stage and decreased, like D. zawadskii, L. platyphylla and S. sarmentosum. Volumetric water content and the amount of evapotranspiration consistently declined in all plant species. The analysis of chlorophyll fluorescence results that S. sarmentosum, which had relatively high drought tolerance, was the last to decline, while Z. japonica and S. sarmentosum withered after rapid reduction. At first, photosynthesis, stomatal conductance and transpiration rate showed high activity, but they lowered as the plant body closed stomata owing to the decrease in volumetric water content. Measuring antioxidants showed that when drought stress increased, the amount of antioxidants grew as well. However, when high moisture stress was maintained, this compound was continuously consumed. Therefore, the variation of antioxidants was considered possible for use as one of the indicators of drought tolerance evaluation.

• Horticultural Science & Technology
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• v.18 no.1
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• pp.28-32
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• 2000

This study was carried out to investigate the effects of uniconazole treatment on the growth and flowering of potted Chrysanthemum indicum L. for high quality pot plant production. Uniconazole was drenched at 0.05, 0.01, or 0.15 mg a.i./pot at 14 days after planting (DAP) of rooted cuttings. Simultaneously the short-day treatment (SDT) and pinching were adapted. The same amount of uniconazole (0.05 mg a.i./pot) was spilt drenched at once, twice, and three times, respectively, at 1 week interval. Uniconazole markedly reduced plant height, branch length, and stem diameter. Plant height was reduced linearly with increasing uniconazole concentration at 0.05, 0.01, or 0.15 mg a.i./pot up-to 41.6%, 52.5%, and 58.5%, respectively. In 0.05 mg a.i./pot, the number of branches greatly increased and plant height of 22.6 cm was adequate for pot plant. However, higher concentrations (0.10, 0.15 mg a.i.) were not suitable for production of high quality pot plant (17.0, 14.8 cm, respectively). Pinching and SDT decreased the number of days to visible bud, while uniconazole treatments delayed days to visible bud by 5-9 days compared with pinching and SDT. Number of visible buds was highest at 0.05 mg a.i./pot uniconazole treatment. However, flower diameter was decreased by uniconazole treatment, resulting in compact form. Number of stomata was increased by uniconazole treatment. The length of vascular tissues of uniconazole-treated plants ($11.2{\mu}m$) was smaller than that of non-treated plants ($15.0{\mu}m$, and the size of xylem vessel was also decreased. Uniconazole treatment at 0.05 mg a.i./pot at 14 DAP with pinching and SDT were recommended for pot plant production of C. indicum L.

• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.44-50
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• 2004

This experiment was conducted to investigate the effects of different levels of light intensity (100, 200, 400 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$, and natural light) on the growth and the fruit quality of cucumber(Cucumis sativus cv. Hyakunari-3). The results of this experiment indicated that plant height and length of lateral shoots were decreased under low light condition, but it was not significantly different among treatments. Leaf area and root weight were lowest under low light intensity(100 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$), but no significant differences were noted between 200 and 400 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$. Photosynthesis rate was decreased with reduced light intensity and total chlorophyll contents, root activity and xylem sap were also decreased under low light intensity, but there was no significant difference between 200 and 400 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$. From the SEM observation the erosion of the guard cells and closed stomata in low light treatment were shown and the size of stoma were small also the stomatal aperture were decreased with reducing the light intensity. Chlorosis in leaves and aborted-liked fruits were appeared under low light condition and Ca and Mg uptake in leaves were decreased by shading in proportion to the decrease of light intensity. Fruit yields were decreased by 65% under 400 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$, and by 80${\sim}$90% under 200 and 100 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$, compared to those under the natural light. This low intensity of light caused the sharp decrease in the early harvested yields within two weeks and the fruit yields of lateral shoots were greatly decreased.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.127-137
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• 1990

This study was carried out to investigate some characteristics of selected trees recognized as natural hybrid between Pinus densiflora and Pinus thunbergii for improving resistance to pine leaf gall midge. The results obtained were as follows. l. In the mean annual increment and the growth in the period of latest 5 years of DBH, hybrid pines showed intermediate value of the parents, Pinus densiflora and Pinus thunbergii. However, there was remarkable variation among individuals of hybrid pine. 2. The trees having resin duct index(RDI) value larger than 0.1 for the position of resin duct in needle was classified as hybrid pine. The leaf and leaf sheath of Pinus thunbergii was longer than that of Pinus densiflora and the distance between rows of stomata on needles of Pinus thunbergii was longer than that of Pinus detasiflora, and the values of those observations on hybrid pine were intermediate between the parent species. However, differences among individual was observed. 3. In the size of cone and seed, and weight of 1000 seeds, like in the leaf characteristics, Pinus thunbergii showed higher value than Pinus densiflora and those values of hybrid were intermediate between the parent species. 4. Assuming isoenzyme ADH-$B_2$, ME-$A_2$, PGI-$B_1$, and PGI-$B_2$ alleles observed in the hybrids were introgressed from Pinus thunbergii, the hybrid pine can be easily identified by these isoenzyme alleles. However, the individuals which do not have those alleles can not be identified.